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Background and Objectives Methods Results Conclusion Intramuscular fat fraction (FF), assessed using quantitative MRI (qMRI), has emerged as a promising biomarker for hereditary transthyretin amyloidosis (ATTRv) patients. Currently, the main drawbacks to its use in future therapeutic trials are its sensitivity to change over a short period of time and the time‐consuming manual segmentation step to extract quantitative data. This pilot study aimed to demonstrate the suitability of an Artificial Intelligence‐based (AI) segmentation technique to assess disease progression in a real‐life cohort of ATTRv patients over 1 year.Fifteen ATTRv patients were included in this monocentric, observational, prospective study. FF, magnetization transfer ratio (MTR), and quantitative T2 were extracted from patients' lower limb qMRI at two time points, 1 year apart, at thigh and leg levels. qMRI parameters were correlated with clinical and electrophysiological parameters assessed at the same time.Global FF at leg level significantly progressed over 1 year: +1.28 ± 2.62% (p = 0.017). At thigh level, no significant change in global FF, MTR, or T2 was measured. The leg FF was strongly correlated with the main clinical and electrophysiological scores.AI‐based CNN network segmentation combined with qMRI can be used to obtain quantitative metrics for longitudinal studies in ATTRv patients. Global FF at the leg level seems to be the most sensitive MRI biomarker to track disease progression in a 1‐year period. Larger studies with treatment‐specific groups will now be necessary to determine the place of qMRI markers compared to the current clinical and electrophysiological scores. [ABSTRACT FROM AUTHOR]

Reduced hippocampal volumes are a feature of many mental disorders. Childhood maltreatment is a known risk factor for the development of psychopathology and has consistently been linked to hippocampal volume reductions in adults, but not in children and adolescents. We propose that maltreatment‐related difficulties in coping with developmental tasks in adolescence and young adulthood might underlie the delayed emergence of hippocampal volume reductions in maltreated individuals. In a study with 196 healthy young adults (mean age [years]: 24.0 ± 3.2, 50% female, 20.6% living with a partner (missings: n = 2)), we investigated the interaction between childhood maltreatment (Childhood Trauma Screener) and the breakup of a steady romantic relationship (List of Threatening Experiences Questionnaire) on hippocampal magnetic resonance imaging grey matter volumes. The experience of a romantic relationship breakup moderated the association between childhood maltreatment and bilateral hippocampal volumes, revealing more negative associations with hippocampal volumes in participants with at least one breakup compared to those with no breakup experience (right hippocampus: β = − 0.05 ± 0.02, p = 0.031, p (FDR) = 0.031; left hippocampus: β = −0.06 ± 0.02, p = 0.005, p (FDR) = 0.009). Moreover, our findings provide some evidence that childhood maltreatment is related to smaller bilateral hippocampal volumes only in those adults who suffered from a relationship breakup (right hippocampus: β = −0.23 ± 0.10, p = 0.018, p (FDR) = 0.018; left hippocampus: β = −0.24 ± 0.10, p = 0.016, p (FDR) = 0.018;). Our study highlights the interaction of adult social bonds with early adversity on vulnerability to psychopathology. [ABSTRACT FROM AUTHOR]

The present study was designed to test the potential utility of regional cerebral oxygen saturation (rcSO2) in detecting term infants with brain injury. The study also examined whether quantitative rcSO2 features are associated with grade of hypoxic ischaemic encephalopathy (HIE). We analysed 58 term infants with HIE (>36 weeks of gestational age) enrolled in a prospective observational study. All newborn infants had a period of continuous rcSO2 monitoring and magnetic resonance imaging (MRI) assessment during the first week of life. rcSO2 Signals were pre‐processed and quantitative features were extracted. Machine‐learning and deep‐learning models were developed to detect adverse outcome (brain injury on MRI or death in the first week) using the leave‐one‐out cross‐validation approach and to assess the association between rcSO2 and HIE grade (modified Sarnat – at 1 h). The machine‐learning model (rcSO2 excluding prolonged relative desaturations) significantly detected infant MRI outcome or death in the first week of life [area under the curve (AUC) = 0.73, confidence interval (CI) = 0.59−0.86, Matthew's correlation coefficient = 0.35]. In agreement, deep learning models detected adverse outcome with an AUC = 0.64, CI = 0.50−0.79. We also report a significant association between rcSO2 features and HIE grade using a machine learning approach (AUC = 0.81, CI = 0.73−0.90). We conclude that automated analysis of rcSO2 using machine learning methods in term infants with HIE was able to determine, with modest accuracy, infants with adverse outcome. De novo approaches to signal analysis of NIRS holds promise to aid clinical decision making in the future. Key points: Hypoxic‐induced neonatal brain injury contributes to both short‐ and long‐term functional deficits.Non‐invasive continuous monitoring of brain oxygenation using near‐infrared‐ spectroscopy offers a potential new insight to the development of serious injury.In this study, characteristics of the NIRS signal were summarised using either predefined features or data‐driven feature extraction, both were combined with a machine learning approach to predict short‐term brain injury.Using data from a cohort of term infants with hypoxic ischaemic encephalopathy, the present study illustrates that automated analysis of regional cerebral oxygen saturation rcSO2, using either machine learning or deep learning methods, was able to determine infants with adverse outcome. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusions The aim of this study was to ascertain whether patient age was a significant factor for the accurate identification of compressive intervertebral disc extrusions (IVDE) in Dachshunds using non‐contrast computed tomography (CT).This retrospective analysis encompassed 150 Dachshunds evaluated for suspected IVDE at a referral hospital in south‐eastern Queensland, Australia. Each case underwent diagnostic evaluation by CT, either with or without myelography, or magnetic resonance imaging (MRI), followed by surgical intervention for an intervertebral disc extrusion.In the <9‐year dog cohort, 94.7% (71/75) were diagnosed with IVDE via non‐contrast CT and proceeded to surgery. In contrast, the ≥9‐year dog cohort, only 56% (42/75) were diagnosed via non‐contrast CT, with the remaining 44% (33/75) necessitating CT myelography or MRI for diagnosis. The odds of requiring CT myelography or MRI increased 13.95‐fold (95% CI, 4.62–42.13) in Dachshunds aged 9 years or older. Furthermore, each additional year of age was associated with a 0.60 increase in the odds of undergoing these advanced imaging modalities (CT myelography or MRI) (95% CI, 0.49–0.74).Age significantly affected the efficacy of non‐contrast CT in diagnosing IVDE in Dachshunds. Dogs aged 9 years and above were substantially more likely to require CT myelography or MRI due to the reduced visibility of disc extrusions on non‐contrast CT. Veterinarians performing advanced imaging on older Dachshunds for suspected IVDE should be aware of the limitations of non‐contrast CT in obtaining an accurate diagnosis and localisation of IVDE, and be prepared to perform either CT myelography or MRI if required. [ABSTRACT FROM AUTHOR]

The article discusses a novel model for integrated prostate cancer diagnostics that combines MRI, prostate biopsy, and pathology reports. Developed by a multi-professional group in Sweden, the model aims to streamline data collection, improve patient outcomes, and enhance quality assessment. The model was tested in a pilot study with positive feedback from urologists, radiologists, and pathologists, showing potential for widespread implementation and validation in clinical practice. The structured approach offers a concise summary of relevant information, benefiting both healthcare providers and patients. [Extracted from the article]

Introduction Methods Results Conclusion The purpose of this study was to address the gap in knowledge in the incidence, presentation and imaging features of PPGL in Fontan patients. It has been hypothesised in the literature that Fontan circulation patients have an increased incidence of these tumours. This study is the largest cohort of adult Fontan patients in North America. The Fontan procedure is a palliative procedure for single ventricle congenital heart disease where the systemic venous return is directed into the pulmonary circulation. Fontan patients are at increased risk of developing several extracardiac complications including phaeochromocytoma and paraganglioma (PPGL).This retrospective single‐centre study includes all adult patients who were treated between 1 September 2015 and 1 September 2022 in a tertiary referral centre for adult congenital heart disease. Imaging and electronic medical records were retrospectively searched for the presence of PPGL.Five hundred and forty‐seven Fontan patients were included in the study. Three patients had PPGL with an incidence of 0.5%. Two patients were diagnosed with paraganglioma and one with phaeochromocytoma. All patients were female. Median age of Fontan procedure was 1.8 years (range: 1.75–27 years). Median age of PPGL diagnosis was 19 years (range: 12–39 years). Median time from Fontan operation to diagnosis of PPGL was 12 years (range: 10.3–17.2 years).Fontan patients are at increased risk of PPGL. Clinically, the diagnosis of PPGL is challenging as symptoms and serum markers can be confounding in this population; however, the imaging features of PPGL remain typical making the role of the radiologist crucial. [ABSTRACT FROM AUTHOR]

ABSTRACT Background & Aims Methods Results Conclusions The clinicopathologic and imaging features of hepatocellular adenomas (HCAs) in Asian population remain unclear. We aimed to analyse clinicopathologic and imaging features of HCAs in Korea and propose an imaging‐based method to differentiate β‐catenin mutated HCA (βHCA) from other subtypes.This retrospective multicenter study included pathologically confirmed HCAs from three tertiary institutions in Korea between 2010 and 2023. HCA subtypes were determined according to the current World Health Organization classification using immunohistochemical staining. Two abdominal radiologists reviewed computed tomography and magnetic resonance imaging scans. The clinical characteristics and imaging features of HCA subtypes were compared. A scoring system for βHCA was developed and validated using development (January 2010–April 2021) and validation (May 2021–March 2023) cohorts.121 patients (47 men; mean age, 39.0 years ±13.5) with 138 HCAs were included. HCAs displayed characteristic clinicopathologic features, including a high proportion of male (38.8%) and obese patients (35.5%), with the inflammatory subtype being the most common (38.4%) and a low percentage of patients using oral contraceptive (5.0%). Each HCA subtype demonstrated distinct clinical and imaging features. The scoring system incorporating tumour heterogeneity and iso to high hepatobiliary phase signal intensity on MRI for differentiating βHCA exhibited high performance in both the development (AUC 0.92, 95% CI: 0.87–0.97) and the validation cohort (AUC 0.91, 95% CI: 0.77–1.00).This comprehensive analysis of clinicopathologic and imaging features of HCAs in Korea contributes to the characterisation of HCAs across different geographical regions. The imaging‐based scoring system effectively differentiates βHCA. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusion Apparent diffusion coefficient (ADC) maps derived from diffusion weighted magnetic resonance imaging (DWI MRI) provides functional measurements about the water molecules in tissues. However, DWI is time consuming and very susceptible to image artifacts, leading to inaccurate ADC measurements. This study aims to develop a deep learning framework to synthesize ADC maps from multi‐parametric MR images.We proposed the multiparametric residual vision transformer model (MPR‐ViT) that leverages the long‐range context of vision transformer (ViT) layers along with the precision of convolutional operators. Residual blocks throughout the network significantly increasing the representational power of the model. The MPR‐ViT model was applied to T1w and T2‐fluid attenuated inversion recovery images of 501 glioma cases from a publicly available dataset including preprocessed ADC maps. Selected patients were divided into training (N = 400), validation (N = 50), and test (N = 51) sets, respectively. Using the preprocessed ADC maps as ground truth, model performance was evaluated and compared against the Vision Convolutional Transformer (VCT) and residual vision transformer (ResViT) models with the peak signal‐to‐noise ratio (PSNR), structural similarity index measure (SSIM), and mean squared error (MSE).The results are as follows using T1w + T2‐FLAIR MRI as inputs: MPR‐ViT—PSNR: 31.0 ± 2.1, MSE: 0.009 ± 0.0005, SSIM: 0.950 ± 0.015. In addition, ablation studies showed the relative impact on performance of each input sequence. Both qualitative and quantitative results indicate that the proposed MR‐ViT model performs favorably against the ground truth data.We show that high‐quality ADC maps can be synthesized from structural MRI using a MPR‐ViT model. Our predicted images show better conformality to the ground truth volume than ResViT and VCT predictions. These high‐quality synthetic ADC maps would be particularly useful for disease diagnosis and intervention, especially when ADC maps have artifacts or are unavailable. [ABSTRACT FROM AUTHOR]

Sickle cell disease is a genetic disorder characterised by abnormal haemoglobin production. This study aims to investigate the associations between haematological and inflammatory biomarkers and brain volumes in patients with sickle cell anaemia and compare brain structure between patients with sickle cell anaemia and healthy controls. This retrospective cross‐sectional study included 130 participants (70 sickle cell anaemia patients and 60 healthy controls) who underwent brain MRI examinations at King Fahad Central Hospital between January 2010 and October 2022. Demographic data and haematological and inflammatory biomarkers were collected to examine their relationships with brain volumes. Brain volumes were measured using FreeSurfer. Specific haematological and inflammatory biomarkers were correlated with brain volume in patients with sickle cell anaemia, p < 0.05. Sickle cell anaemia patients exhibited smaller volumes in the brainstem, corpus callosum and amygdala compared to healthy controls. Males had significantly higher iron levels (p < 0.001) and larger various brain structure volumes (p < 0.05) than females. This study demonstrates significant associations between specific biomarkers and brain volume in sickle cell anaemia patients, underscoring the importance of monitoring these biomarkers for early detection and management of neurological complications in sickle cell anaemia. [ABSTRACT FROM AUTHOR]

Background: Dogs with internal hydrocephalus do not necessarily have high intraventricular pressure (IVP). Hypothesis/Objectives: Not all reported MRI findings indicate high IVP and some clinical signs might be associated with elevated IVP and syringomyelia. Animals: Fifty‐three dogs. Materials and Methods: Cross‐sectional study. Clinical signs and MRI findings were evaluated for an association of IVP >12 mm Hg and syringomyelia. Results: High IVP was associated with obtundation OR 4.64 (95% CI 1.27‐16.93) (P =.02), head tilt OR 6.42 (95% CI 1.08‐37.97) (P =.04) and nystagmus OR 8.24 (95% CI 1.44‐47.07) (P =.02). Pain was associated with syringomyelia OR 3.4 (95% CI 0.98‐11.78) (P =.05). The number of affected ventricles was associated with high IVP OR 2.85 (95% CI 0.97‐8.33) (P =.05) and syringomyelia OR 12.74 (95% CI 2.93‐55.4) (P =.0007). Periventricular edema OR 24.46 (95% CI 4.54‐131.77), OR 7.61 (95% CI 1.91‐30.32) (P <.0002, P =.004) and signal void sign OR 17.34 (95% CI 4.01‐74.95), OR 4.18 (95% CI 1.16‐15.02) (P <.0001, P =.03) were associated with high IVP and syringomyelia. The probability for syringomyelia is lower with disruption of the internal capsule OR 0.19 (95% CI 0.05‐0.72) (P =.01) and higher VBR OR 0.25 (95% CI 0.1‐0.63) (P =.004). Conclusions and Clinical Importance: Previously reported MRI findings are not predictive of high IVP. Clinical signs and MRI findings should be used to make a diagnosis of internal hydrocephalus in dogs with or without high IVP. [ABSTRACT FROM AUTHOR]

Regular blood glucose monitoring and control is necessary for people with type 1 or advanced type 2 diabetes, yet diagnosing and treating patients with diabetes in an accurate, sustained and patient‐friendly manner remains limited. Here, a glucose‐responsive bifunctional nanosystem (PGOxMns) is constructed via one‐pot biomineralisation of manganese dioxide with glucose oxidase and ε‐poly‐L‐lysine. Under hyperglycaemic conditions, the cascade reactions that occur when glucose interacts with PGOxMns can trigger the production of Mn(II), which enhances the magnetic resonance imaging signal. Simultaneously, manganese dioxide catalyses the decomposition of toxic hydrogen peroxide into oxygen, which also maintains glucose oxidase (GOx) activity. In an in vivo model of diabetes, PGOxMns is used to monitor glucose levels (0–20 mm) and allowed identification of diabetic mice via T1‐weighted MRI. Furthermore, PGOxMns is found to have a high insulin‐loading capacity (83.6%), likely due to its positive charge. A single subcutaneous injection of insulin‐loaded nanosystem (Ins‐PGOxMns) into diabetic mice resulted in a rapid and efficient response to a glucose challenge and prolonged blood glucose level control (< 200 mg dL−1) for up to 50 h. Overall, this proof‐of‐concept study demonstrates the feasibility of using biomineralised nanosystems to develop patient‐friendly strategies for glucose monitoring and control. [ABSTRACT FROM AUTHOR]

This study introduces OpenMAP‐T1, a deep‐learning‐based method for rapid and accurate whole‐brain parcellation in T1‐ weighted brain MRI, which aims to overcome the limitations of conventional normalization‐to‐atlas‐based approaches and multi‐atlas label‐fusion (MALF) techniques. Brain image parcellation is a fundamental process in neuroscientific and clinical research, enabling a detailed analysis of specific cerebral regions. Normalization‐to‐atlas‐based methods have been employed for this task, but they face limitations due to variations in brain morphology, especially in pathological conditions. The MALF techniques improved the accuracy of the image parcellation and robustness to variations in brain morphology, but at the cost of high computational demand that requires a lengthy processing time. OpenMAP‐T1 integrates several convolutional neural network models across six phases: preprocessing; cropping; skull‐stripping; parcellation; hemisphere segmentation; and final merging. This process involves standardizing MRI images, isolating the brain tissue, and parcellating it into 280 anatomical structures that cover the whole brain, including detailed gray and white matter structures, while simplifying the parcellation processes and incorporating robust training to handle various scan types and conditions. The OpenMAP‐T1 was validated on the Johns Hopkins University atlas library and eight available open resources, including real‐world clinical images, and the demonstration of robustness across different datasets with variations in scanner types, magnetic field strengths, and image processing techniques, such as defacing. Compared with existing methods, OpenMAP‐T1 significantly reduced the processing time per image from several hours to less than 90 s without compromising accuracy. It was particularly effective in handling images with intensity inhomogeneity and varying head positions, conditions commonly seen in clinical settings. The adaptability of OpenMAP‐T1 to a wide range of MRI datasets and its robustness to various scan conditions highlight its potential as a versatile tool in neuroimaging. [ABSTRACT FROM AUTHOR]

Structural disconnectome analyses have provided valuable insights into how a stroke lesion results in widespread network disturbances and how these relate to deficits, recovery patterns, and outcomes. Previous analyses have primarily focused on patients with relatively mild to moderate deficits. However, outcomes vary among survivors of severe strokes, and the mechanisms of recovery remain poorly understood. This study assesses the association between lesion‐induced network disconnection and outcome after severe stroke. Thirty‐eight ischaemic stroke patients underwent MRI brain imaging early after stroke and longitudinal clinical follow‐up. Lesion information was integrated with normative connectome data to infer individual disconnectome profiles on a localized regional and region‐to‐region pathway level. Ordinal logistic regressions were computed to link disconnectome information to the modified Rankin Scale after 3–6 months. Disconnections of ipsilesional frontal, parietal, and temporal cortical brain areas were significantly associated with a worse motor outcome after a severe stroke, adjusted for the initial deficit, lesion volume, and age. The analysis of the underlying pathways mediating this association revealed location‐specific results: For frontal, prefrontal, and temporal brain areas, the association was primarily driven by relatively sparse intrahemispheric disconnections. In contrast, the ipsilesional primary motor cortex, the dorsal premotor cortex, and various parietal brain regions showed a remarkable involvement of either frontoparietal intrahemispheric or additionally interhemispheric disconnections. These results indicate that localized disconnection of multiple regions embedded in the structural frontoparietal network correlates with worse outcomes after severe stroke. Specifically, primary motor and parietal cortices might gain particular importance as they structurally link frontoparietal networks of both hemispheres. These data shed novel light on the significance of distinct brain networks for recovery after a severe stroke. [ABSTRACT FROM AUTHOR]

Background and purpose: Susceptibility estimates derived from quantitative susceptibility mapping (QSM) images for the cerebral cortex and major subcortical structures are variably reported in brain magnetic resonance imaging (MRI) studies, as average of all (μall${{{{\mu}}}_{{\mathrm{all}}}}$), absolute (μabs${{{{\mu}}}_{{\mathrm{abs}}}}$), or positive‐ (μp${{{{\mu}}}_{\mathrm{p}}}$) and negative‐only (μn${{{{\mu}}}_{\mathrm{n}}}$) susceptibility values using a region of interest (ROI) approach. This pilot study presents a reliability analysis of currently used ROI‐QSM metrics and an alternative ROI‐based approach to obtain voxel‐weighted ROI‐QSM metrics (μwp${{{{\mu}}}_{{\mathrm{wp}}}}$ and μwn${{{{\mu}}}_{{\mathrm{wn}}}}$). Methods: Ten healthy subjects underwent repeated (test‐retest) 3‐dimensional multi‐echo gradient‐echo (3DMEGE) 3 Tesla MRI measurements. Complex‐valued 3DMEGE images were acquired and reconstructed with slice thicknesses of 1 and 2 mm (3DMEGE1, 3DMEGE2) along with 3DT1‐weighted isometric (voxel 1 mm3) images for independent registration and ROI segmentation. Agreement, consistency, and reproducibility of ROI‐QSM metrics were assessed through Bland‐Altman analysis, intraclass correlation coefficient, and interscan and intersubject coefficient of variation (CoV). Results: All ROI‐QSM metrics exhibited good to excellent consistency and test‐retest agreement with no proportional bias. Interscan CoV was higher for μall${{{{\mu}}}_{{\mathrm{all}}}}$ in comparison to the other metrics where it was below 15%, in both 3DMEGE1 and 3DMEGE2 datasets. Intersubject CoV for μall${{{{\mu}}}_{{\mathrm{all}}}}$ and μabs${{{{\mu}}}_{{\mathrm{abs}}}}$ exceeded 50% in all ROIs. Conclusions: Among the evaluated ROI‐QSM metrics, μall${{{{\mu}}}_{{\mathrm{all}}}}$ and μabs${{{{\mu}}}_{{\mathrm{abs}}}}$ estimates were less reliable, whereas separating positive and negative values (using μp,μn,μwp,μwn${{{{\mu}}}_{\mathrm{p}}},\ {{{{\mu}}}_{\mathrm{n}}},\ {{{{\mu}}}_{{\mathrm{wp}}}},\ {{{{\mu}}}_{{\mathrm{wn}}}}$) improved the reproducibility within, and the comparability between, subjects, even when reducing the slice thickness. These preliminary findings may offer valuable insights toward standardizing ROI‐QSM metrics across different patient cohorts and imaging settings in future clinical MRI studies. [ABSTRACT FROM AUTHOR]

Background and Purpose: To develop and test a decision tree for predicting contrast enhancement quality and shape using precontrast magnetic resonance imaging (MRI) sequences in a large adult‐type diffuse glioma cohort. Methods: Preoperative MRI scans (development/optimization/test sets: n = 31/38/303, male = 17/22/189, mean age = 52/59/56.7 years, high‐grade glioma = 22/33/249) were retrospectively evaluated, including pre‐ and postcontrast T1‐weighted, T2‐weighted, fluid‐attenuated inversion recovery, and diffusion‐weighted imaging sequences. Enhancement prediction decision tree (EPDT) was developed using development and optimization sets, incorporating four imaging features: necrosis, diffusion restriction, T2 inhomogeneity, and nonenhancing tumor margins. EPDT accuracy was assessed on a test set by three raters of variable experience. True enhancement features (gold standard) were evaluated using pre‐ and postcontrast T1‐weighted images. Statistical analysis used confusion matrices, Cohen's/Fleiss' kappa, and Kendall's W. Significance threshold was p <.05. Results: Raters 1, 2, and 3 achieved overall accuracies of.86 (95% confidence interval [CI]:.81‐.90),.89 (95% CI:.85‐.92), and.92 (95% CI:.89‐.95), respectively, in predicting enhancement quality (marked, mild, or no enhancement). Regarding shape, defined as the thickness of enhancing margin (solid, rim, or no enhancement), accuracies were.84 (95% CI:.79‐.88),.88 (95% CI:.84‐.92), and.89 (95% CI:.85‐.92). Intrarater intergroup agreement comparing predicted and true enhancement features consistently reached substantial levels (≥.68 [95% CI:.61‐.75]). Interrater comparison showed at least moderate agreement (group: ≥.42 [95% CI:.36‐.48], pairwise: ≥.61 [95% CI:.50‐.72]). Among the imaging features in the EPDT, necrosis assessment displayed the highest intra‐ and interrater consistency (≥.80 [95% CI:.73‐.88]). Conclusion: The proposed EPDT has high accuracy in predicting enhancement patterns of gliomas irrespective of rater experience. [ABSTRACT FROM AUTHOR]

Background: Geometric distortion is a serious problem in MRI, particularly in MRI guided therapy. A lack of affordable and adaptable tools in this area limits research progress and harmonized quality assurance. Purpose: To develop and test a suite of open‐source hardware and software tools for the measurement, characterization, reporting, and correction of geometric distortion in MRI. Methods: An open‐source python library was developed, comprising modules for parametric phantom design, data processing, spherical harmonics, distortion correction, and interactive reporting. The code was used to design and manufacture a distortion phantom consisting of 618 oil filled markers covering a sphere of radius 150 mm. This phantom was imaged on a CT scanner and a novel split‐bore 1.0 T MRI magnet. The CT images provide distortion‐free dataset. These data were used to test all modules of the open‐source software. Results: All markers were successfully extracted from all images. The distorted MRI markers were mapped to undistorted CT data using an iterative search approach. Spherical harmonics reconstructed the fitted gradient data to 1.0 ± 0.6% of the input data. High resolution data were reconstructed via spherical harmonics and used to generate an interactive report. Finally, distortion correction on an independent data set reduced distortion inside the DSV from 5.5 ± 3.1 to 1.6 ± 0.8 mm. Conclusion: Open‐source hardware and software for the measurement, characterization, reporting, and correction of geometric distortion in MRI have been developed. The utility of these tools has been demonstrated via their application on a novel 1.0 T split bore magnet. [ABSTRACT FROM AUTHOR]

Objective: To determine the diagnostic accuracy of virtual autopsy using whole‐body postmortem ultra‐high field magnetic resonance imaging (MRI) at 7 Tesla (T), using a short T2‐weighted imaging (T2‐WI) protocol, compared with classical autopsy, for detecting structural abnormalities in small second‐trimester fetuses. Methods: Thirty consecutive fetuses at 13–19 weeks' gestation (weight, 17–364 g) were included following spontaneous pregnancy loss or termination of pregnancy. After fixation in 10% formaldehyde solution (48 h to 1 week), all fetuses were scanned using a two‐dimensional turbo high‐resolution T2‐WI protocol with multislice relaxation time, followed by an invasive autopsy. The diagnostic accuracy of virtual autopsy vs classical autopsy was calculated for 990 anatomical structures (30 fetuses × 33 items). Sensitivity, specificity, positive and negative predictive values and Cohen's κ coefficient of agreement, with their 95% CIs, as well as the McNemar test, were used to evaluate the accuracy and agreement of the two diagnostic methods. Analysis was stratified by anatomical segment (nervous, pulmonary, cardiovascular, digestive, renal, facial and skeletal) and across three gestational‐age intervals (13–14, 15–16 and 17–19 weeks). Results: Considering classical autopsy as the gold standard, virtual autopsy had a sensitivity of 92.04% (95% CI, 85.42–96.29%) and a specificity of 97.87% (95% CI, 94.64–99.42%), with a positive predictive value of 96.30% (95% CI, 90.78–98.56%) and a negative predictive value of 95.34% (95% CI, 91.61–97.45%), achieving a diagnostic accuracy of 95.68% (95% CI, 92.73–97.68%) for detecting structural abnormalities in second‐trimester fetuses. Cohen's κ for virtual vs classical autopsy was 0.907. The diagnostic ability of virtual autopsy at 7 T for malformed fetuses was superior to that of classical autopsy for analyzing the nervous system in small fetuses with pronounced autolysis, equivalent to that of classical autopsy when analyzing pulmonary, cardiovascular and renal systems and inferior when evaluating the fetal intestines. The sensitivity of virtual autopsy at 7 T for describing structural abnormalities increased with gestational age. Conclusion: Virtual fetal autopsy using 7‐T MRI and a turbo high‐resolution T2‐WI protocol with multislice relaxation time is a feasible postmortem diagnostic tool for the identification of fetal structural anomalies. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Objective: Parental counseling for fetal malformations of cortical development (MCD) is based on data from studies in children and adults undergoing imaging investigation for abnormal neurodevelopment. However, such postnatal findings may not be applicable to prenatally diagnosed cases. The aim of this study was to review the existing data on postnatal neurodevelopmental outcome for fetuses diagnosed with MCD. Methods: A literature search was conducted in PubMed, Web of Science and EMBASE for articles published between 2013 and 2023, using standardized keywords to describe fetal cortical malformations. Full‐text articles were accessed for the retrieved citations and data on participant characteristics, imaging findings, and pregnancy and neonatal outcomes were extracted. Fetal MCD was defined as either complex or isolated, according to the presence or absence, respectively, of additional brain or extracranial defects. Results: Overall, 30 articles including 371 cases of fetal MCD were reviewed. The cases were classified as complex (n = 324), isolated (n = 21) or unknown (n = 26). There were 144 terminations and four stillbirths, with pregnancy outcome unreported in 149 cases. A total of 108 cases had postnatal magnetic resonance imaging or postmortem examination data available. In nine of these cases, a diagnosis of complex fetal MCD was changed to isolated MCD after birth, and one case was found not to have MCD. There were 74 live births, for which postnatal neurodevelopment data were available in only 30 cases. Normal neurodevelopmental outcome was reported in seven (23.3% (95% CI, 9.9–42.2%)) infants, with the remaining 23 exhibiting various levels of neurodevelopmental delay (three mild, seven moderate and 13 severe) from 6 months to 7 years of age. Conclusions: Most reviewed cases of fetal MCD were complex in nature and underwent termination of pregnancy. There is a paucity of data on postnatal neurological development in fetuses diagnosed with MCD. The available data suggest antenatal overdiagnosis of case severity in about 5% of cases with known outcome, and either normal neurodevelopment or mild neurodevelopmental delay in approximately one‐third of liveborn cases with neurological follow‐up. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Premature birth or complications during labor can cause temporary disruption of cerebral blood flow, often followed by long‐term disturbances in brain development called hypoxic–ischemic (HI) encephalopathy. Diffuse damage to the white matter is the most frequently detected pathology in this condition. We hypothesized that oligodendrocyte progenitor cell (OPC) differentiation disturbed by mild neonatal asphyxia may affect the viability, maturation, and physiological functioning of oligodendrocytes. To address this issue, we studied the effect of temporal HI in the in vivo model in P7 rats with magnetic resonance imaging (MRI), microscopy techniques and biochemical analyses. Moreover, we recreated the injury in vitro performing the procedure of oxygen–glucose deprivation on rat neonatal OPCs to determine its effect on cell viability, proliferation, and differentiation. In the in vivo model, MRI evaluation revealed changes in the volume of different brain regions, as well as changes in the directional diffusivity of water in brain tissue that may suggest pathological changes to myelinated neuronal fibers. Hypomyelination was observed in the cortex, striatum, and CA3 region of the hippocampus. Severe changes to myelin ultrastructure were observed, including delamination of myelin sheets. Interestingly, shortly after the injury, an increase in oligodendrocyte proliferation was observed, followed by an overproduction of myelin proteins 4 weeks after HI. Results verified with the in vitro model indicate, that in the first days after damage, OPCs do not show reduced viability, intensively proliferate, and overexpress myelin proteins and oligodendrocyte‐specific transcription factors. In conclusion, despite the increase in oligodendrocyte proliferation and myelin protein expression after HI, the production of functional myelin sheaths in brain tissue is impaired. Presented study provides a detailed description of oligodendrocyte pathophysiology developed in an effect of HI injury, resulting in an altered CNS myelination. The described models may serve as useful tools for searching and testing effective of effective myelination‐supporting therapies for HI injuries. [ABSTRACT FROM AUTHOR]

Quantitative methods to characterize bone contusions and associated cartilage injury remain limited. We combined standardized voxelwise normalization and 3D mapping to automate bone contusion segmentation post‐anterior cruciate ligament (ACL) injury and evaluate anomalies in articular cartilage overlying bone contusions. Forty‐five patients (54% female, 26.4 ± 11.8 days post‐injury) with an ACL tear underwent 3T magnetic resonance imaging of their involved and uninvolved knees. A novel method for voxelwise normalization and 3D anatomical mapping was used to automate segmentation, labeling, and localization of bone contusions in the involved knee. The same mapping system was used to identify the associated articular cartilage overlying bone lesions. Mean regional T1ρ was extracted from articular cartilage regions in both the involved and uninvolved knees for quantitative paired analysis against ipsilateral cartilage within the same compartment outside of the localized bone contusion. At least one bone contusion lesion was detected in the involved knee within the femur and/or tibia following ACL injury in 42 participants. Elevated T1ρ (p = 0.033) signal were documented within the articular cartilage overlying the bone contusions resulting from ACL injury. In contrast, the same cartilaginous regions deprojected onto the uninvolved knees showed no ipsilateral differences (p = 0.795). Automated bone contusion segmentation using standardized voxelwise normalization and 3D mapping deprojection identified altered cartilage overlying bone contusions in the setting of knee ACL injury. [ABSTRACT FROM AUTHOR]

Background: Gastric fluid plays a key role in food digestion and drug dissolution, therefore, the amount of gastric fluid present in a fasted state may influence subsequent digestion and drug delivery. We aimed to describe intra‐ and interindividual variation in fasted gastric content volume (FGCV) and to determine the association with age, sex, and body size characteristics. Methods: Data from 24 MRI studies measuring FGCV in healthy, mostly young individuals after an overnight fast were pooled. The analysis included 366 participants who had up to 6 repeated measurements, with a total of 870 measurements. Linear mixed model analysis was performed to calculate intra‐ and interindividual variability and to assess the effects of age, sex, weight, height, weight*height as a proxy for body size, and body mass index (BMI). Results: FGCV ranged from 0 to 156 mL, with a mean (± SD) value of 33 ± 25 mL. The overall coefficient of variation within the study population was 75.6%, interindividual SD was 15 mL, and the intraindividual SD was 19 mL. Age, weight, height, weight*height, and BMI had no effect on FGCV. Women had lower volumes compared to men (MD: −6 mL), when corrected for the aforementioned factors. Conclusion: FGCV is highly variable, with higher intraindividual compared to interindividual variability, indicating that FGCV is subject to day‐to‐day and within‐day variation and is not a stable personal characteristic. This highlights the importance of considering FGCV when studying digestion and drug dissolution. Exact implications remain to be studied. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Brain magnetic resonance imaging (MRI) and inflammatory biomarkers are crucial for investigating preclinical neurocognitive disorders. Current investigations focus on a few inflammatory markers. The study aims to investigate the associations between inflammatory biomarkers and MRI measures and to examine sex differences among the associations in the Framingham Heart Study. METHODS: Dementia and stroke‐free participants underwent OLINK Proteomics profiling and MRI measurements within 5 years. Pairwise cross‐sectional analysis assessed 68 biomarkers with 13 brain MRI volumes, adjusting for covariates and familial correlations. RESULTS: Elevated CDCP1, IL6, OPG, and 4E.BP1 were related to smaller total cerebral brain volume (TCBV), whereas higher HGF, IL8, and MMP10 were associated with smaller TCBV, total and frontal white matter volumes. Higher SCF and TWEAK were associated with larger TCBV. In sex‐stratified analyses, associations were observed exclusively among males. DISCUSSION: We report several associations between inflammatory biomarkers and brain volumes, highlighting different associations within sex subgroups. Highlights: Higher CDCP1, IL6, OPG, and 4E.BP1 levels were associated with smaller TCBV.Higher levels of HGF, IL8 and MMP10 were associated with smaller TCBV, CWV and FWV.Higher levels of SCF and TWEAK, were associated with larger TCBV.Significance diminished in models adjusting for CVD risk factors.Associations were observed exclusively in males. [ABSTRACT FROM AUTHOR]

Extradural neoplasms are the most common spinal tumors in small animals. A bilobed appearance of ventral extradural spinal lesions ("gullwing sign") on MRI has been described with various conditions. The objective of this retrospective study was to determine if a "gullwing sign" is more common with certain types of extradural tumors. MRI studies of dogs and cats with extradural spinal neoplasms were reviewed for the presence of a "gullwing sign". Statistical analysis was performed to evaluate a possible relationship between tumor class and the presence of a "gullwing sign". Sixty‐six cases were included (5 epithelial, 31 mesenchymal, 4 neuroendocrine, and 26 round cell tumors). A "gullwing sign" was identified in 12 of 66 cases (18.2%) and was significantly more common with round cell neoplasia than other tumor types (P <.001; OR = 28.6, 95% CI [3.4, 241.1]). This information may aid radiologists in prioritizing differential diagnoses for extradural tumors in small animals. [ABSTRACT FROM AUTHOR]

Duchenne muscular dystrophy (DMD) is a progressive X‐linked neuromuscular disorder caused by the absence of functional dystrophin protein. In addition to muscle, dystrophin is expressed in the brain in both neurons and glial cells. Previous studies have shown altered white matter microstructure in patients with DMD using diffusion tensor imaging (DTI). However, DTI measures the diffusion properties of water, a ubiquitous molecule, making it difficult to unravel the underlying pathology. Diffusion‐weighted spectroscopy (DWS) is a complementary technique which measures diffusion properties of cell‐specific intracellular metabolites. Here we performed both DWS and DTI measurements to disentangle intra‐ and extracellular contributions to white matter changes in patients with DMD. Scans were conducted in patients with DMD (15.5 ± 4.6 y/o) and age‐ and sex‐matched healthy controls (16.3 ± 3.3 y/o). DWS measurements were obtained in a volume of interest (VOI) positioned in the left parietal white matter. Apparent diffusion coefficients (ADCs) were calculated for total N‐acetylaspartate (tNAA), choline compounds (tCho), and total creatine (tCr). The tNAA/tCr and tCho/tCr ratios were calculated from the non‐diffusion‐weighted spectrum. Mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD), and fractional anisotropy of water within the VOI were extracted from DTI measurements. DWS and DTI data from patients with DMD (respectively n = 20 and n = 18) and n = 10 healthy controls were included. No differences in metabolite ADC or in concentration ratios were found between patients with DMD and controls. In contrast, water diffusion (MD, t = −2.727, p = 0.011; RD, t = −2.720, p = 0.011; AD, t = −2.715, p = 0.012) within the VOI was significantly higher in patients compared with healthy controls. Taken together, our study illustrates the potential of combining DTI and DWS to gain a better understanding of microstructural changes and their association with disease mechanisms in a clinical setting. [ABSTRACT FROM AUTHOR]

We aim to explore the feasibility of head and neck time‐of‐flight (TOF) magnetic resonance angiography (MRA) at ultra‐low‐field (ULF). TOF MRA was conducted on a highly simplified 0.05 T MRI scanner with no radiofrequency (RF) and magnetic shielding. A flow‐compensated three‐dimensional (3D) gradient echo (GRE) sequence with a tilt‐optimized nonsaturated excitation RF pulse, and a flow‐compensated multislice two‐dimensional (2D) GRE sequence, were implemented for cerebral artery and vein imaging, respectively. For carotid artery and jugular vein imaging, flow‐compensated 2D GRE sequences were utilized with venous and arterial blood presaturation, respectively. MRA was performed on young healthy subjects. Vessel‐to‐background contrast was experimentally observed with strong blood inflow effect and background tissue suppression. The large primary cerebral arteries and veins, carotid arteries, jugular veins, and artery bifurcations could be identified in both raw GRE images and maximum intensity projections. The primary brain and neck arteries were found to be reproducible among multiple examination sessions. These preliminary experimental results demonstrated the possibility of artery TOF MRA on low‐cost 0.05 T scanners for the first time, despite the extremely low MR signal. We expect to improve the quality of ULF TOF MRA in the near future through sequence development and optimization, ongoing advances in ULF hardware and image formation, and the use of vascular T1 contrast agents. [ABSTRACT FROM AUTHOR]

Diffusion‐tensor (DT)‐MRI tractography provides information about properties relevant to muscle health and function, including estimates of architectural properties such as fascicle length, pennation angle, and curvature and diffusion properties such as mean diffusivity (MD) and fractional anisotropy (FA). Tractography settings, including integration algorithms, thresholds for early tract termination, and tract smoothing approaches, impact the accuracy of the muscle property estimates. However, muscle DT‐MRI tractography is performed using a variety of these settings, complicating comparisons between different studies. The effects of different tractography settings on muscle architecture estimates have not been fully explored, and optimized settings for muscle tractography have not yet been determined. We examined the influence of integration algorithm and termination check settings combined with a range of step sizes, termination criteria, and smoothing polynomial orders on tract characteristics, completion/reason for termination, and goodness of fit between fiber tracts and smoothing polynomials using 3‐T DT‐MR images of the lower leg muscles of seven healthy adults. We found that tract length and completion were highly sensitive to strict FA and intersegment angle thresholds (25%–69% reduction in complete fiber tracts from lowest to highest minimum FA threshold and 11%–36% reduction from highest to lowest intersegment angle threshold). Higher order polynomials (third and fourth order vs. second order) better fit the muscle fiber trajectories, but curvature estimates were highly sensitive to smoothing polynomial order (3.9–6.6 m−1 increase for second‐ vs. fourth‐order fitting polynomials). Step size impacted curvature estimates, albeit to a lesser degree. Integration algorithm had little impact, and mean pennation angle, and tract‐based FA and MD, were relatively insensitive to all parameters. The results demonstrate which muscle diffusion measures and architectural estimates are most sensitive to varying tractography settings and support the need for consistent reporting of tractography details to aid interpretation and comparison of results between studies. [ABSTRACT FROM AUTHOR]

Purpose: Quantitative magnetization transfer (qMT) models aim to quantify the contributions of lipids and macromolecules to the MRI signal. Hence, a model system that relates qMT parameters and their molecular sources may improve the interpretation of the qMT parameters. Here we used membrane lipid phantoms as a meaningful tool to study qMT models. By controlling the fraction and type of membrane lipids, we could test the accuracy, reliability, and interpretability of different qMT models. Methods: We formulated liposomes with various lipid types and water‐to‐lipids fractions and measured their signals with spoiled gradient‐echo MT. We fitted three known qMT models and estimated six parameters for every model. We tested the accuracy and reproducibility of the models and compared the dependency among the qMT parameters. We compared the samples' qMT parameters with their water‐to‐lipid fractions and with a simple MTnorm (= MTon/MToff) calculation. Results: We found that the three qMT models fit the membrane lipids signals well. We also found that the estimated qMT parameters are highly interdependent. Interestingly, the estimated qMT parameters are a function of the membrane lipid type and also highly related to the water‐to‐lipid fraction. Finally, we find that most of the lipid sample's information can be captured using the common and easy to estimate MTnorm analysis. Conclusion: qMT parameters are sensitive to both the water‐to‐lipid fraction and to the lipid type. Estimating the water‐to‐lipid fraction can improve the characterization of membrane lipids' contributions to qMT parameters. Similar characterizations can be obtained using the MTnorm analysis. [ABSTRACT FROM AUTHOR]

Gliomas are primary brain tumors and are among the most malignant types. Adult‐type diffuse gliomas can be classified based on their histological and molecular signatures as IDH‐wildtype glioblastoma, IDH‐mutant astrocytoma, and IDH‐mutant and 1p/19q‐codeleted oligodendroglioma. Recent studies have shown that each subtype of glioma has its own specific distribution pattern. However, the mechanisms underlying the specific distributions of glioma subtypes are not entirely clear despite partial explanations such as cell origin. To investigate the impact of multi‐scale brain attributes on glioma distribution, we constructed cumulative frequency maps for diffuse glioma subtypes based on T1w structural images and evaluated the spatial correlation between tumor frequency and diverse brain attributes, including postmortem gene expression, functional connectivity metrics, cerebral perfusion, glucose metabolism, and neurotransmitter signaling. Regression models were constructed to evaluate the contribution of these factors to the anatomic distribution of different glioma subtypes. Our findings revealed that the three different subtypes of gliomas had distinct distribution patterns, showing spatial preferences toward different brain environmental attributes. Glioblastomas were especially likely to occur in regions enriched with synapse‐related pathways and diverse neurotransmitter receptors. Astrocytomas and oligodendrogliomas preferentially occurred in areas enriched with genes associated with neutrophil‐mediated immune responses. The functional network characteristics and neurotransmitter distribution also contributed to oligodendroglioma distribution. Our results suggest that different brain transcriptomic, neurotransmitter, and connectomic attributes are the factors that determine the specific distributions of glioma subtypes. These findings highlight the importance of bridging diverse scales of biological organization when studying neurological dysfunction. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Methods Results Conclusions To evaluate the association of standardized prenatal imaging parameters and immediate neonatal variables with mortality prior to discharge in infants with isolated left congenital diaphragmatic hernia (LCDH), and to compare the performance of ultrasound‐ and magnetic resonance imaging (MRI)‐based severity grading for the prediction of neonatal mortality.This was a retrospective study of infants with prenatally diagnosed isolated LCDH referred to a single tertiary center between 2008 and 2020. Fetuses with right or bilateral congenital diaphragmatic hernia, additional major structural anomaly or known genetic condition, as well as cases that underwent fetal intervention or declined postnatal intervention, were excluded. Ultrasound and MRI images were reviewed retrospectively. Univariable and multivariable analyses were performed, incorporating prenatal and immediate neonatal factors to analyze the association with neonatal mortality prior to discharge, and a prediction calculator was generated. The performance of ultrasound and that of MRI for the prediction of neonatal mortality were compared.Of 253 pregnancies with fetal CDH, 104 met the inclusion criteria, of whom 77 (74%) neonates survived to discharge. Seventy‐five fetuses underwent both prenatal ultrasound and MRI. On multivariable analysis, observed/expected (o/e) lung‐to‐head ratio and o/e total fetal lung volume were associated independently with neonatal death (adjusted odds ratio, 0.89 (95% CI, 0.83–0.95) and 0.90 (95% CI, 0.84–0.97), respectively), whereas liver position was not. There was no significant difference in predictive performance between using ultrasound and MRI together (area under the receiver‐operating‐characteristics curve (AUC), 0.85 (95% CI, 0.76–0.93)) compared with using ultrasound alone (AUC, 0.81 (95% CI, 0.72–0.90); P = 0.19). The addition of neonatal parameters (gestational age at birth and small‐for‐gestational age) did not improve model performance (AUC, 0.87 (95% CI, 0.80–0.95)) compared with the combined ultrasound and MRI model (P = 0.22). There was poor agreement between severity assessment on ultrasound and MRI (Cohen's κ, 0.19). Most discrepancies were seen among cases deemed to be non‐severe on ultrasound and severe on MRI, and outcomes were more consistent with MRI‐based prognostication.In fetuses with prenatally diagnosed isolated LCDH, mortality prediction using standardized ultrasound and MRI measurements performed reasonably well. In cases classified as non‐severe on ultrasound, MRI is recommended, as it may provide more accurate prognostication and assist in the determination of candidacy for fetal intervention. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Design Results Conclusion The aim of this investigation was to explore the potential correlation between the signal intensity ratio (SIR) at the internal auditory canal (IAC) fundus and hearing impairment in Meniere's disease (MD), thereby providing a foundation to further understand the mechanisms underlying hearing loss.Fifty patients diagnosed with unilateral definite MD were enrolled in the study. 3D‐FLAIR MRI was conducted 4 h after intravenous administration of gadobutrol to determine the SIR of the bilateral IAC fundus. The difference in the SIR of the IAC fundus between the affected and unaffected sides was assessed, followed by an analysis of its correlation with low‐, middle‐, and high‐tone hearing thresholds. Correlation analysis was also conducted between the degree of endolymphatic hydrops (EH) in the vestibule and cochlea and the SIR on the affected side.The degree of EH in MD can be clearly visualised using 3D‐FLAIR MRI. The SIR on the affected side was significantly higher than that on the unaffected side (p = 0.000). Furthermore, a positive correlation was observed between the SIR at the affected and low (r = 0.692, p = 0.000), middle (r = 0.615, p = 0.000) and high‐tone (r = 0.440, p = 0.001) hearing thresholds, while the SIR showed no significant correlation with cochlear (r = 0.315, p = 0.088) or vestibular hydrops (r = 0.215, p = 0.244).The IAC fundus barrier may be damaged in patients with MD, representing one of the factors affecting the level of hearing. [ABSTRACT FROM AUTHOR]

Inquiries into properties of brain structure and function have progressed due to developments in magnetic resonance imaging (MRI). To sustain progress in investigating and quantifying neuroanatomical details in vivo, the reliability and validity of brain measurements are paramount. Quality control (QC) is a set of procedures for mitigating errors and ensuring the validity and reliability of brain measurements. Despite its importance, there is little guidance on best QC practices and reporting procedures. The study of hippocampal subfields in vivo is a critical case for QC because of their small size, inter‐dependent boundary definitions, and common artifacts in the MRI data used for subfield measurements. We addressed this gap by surveying the broader scientific community studying hippocampal subfields on their views and approaches to QC. We received responses from 37 investigators spanning 10 countries, covering different career stages, and studying both healthy and pathological development and aging. In this sample, 81% of researchers considered QC to be very important or important, and 19% viewed it as fairly important. Despite this, only 46% of researchers reported on their QC processes in prior publications. In many instances, lack of reporting appeared due to ambiguous guidance on relevant details and guidance for reporting, rather than absence of QC. Here, we provide recommendations for correcting errors to maximize reliability and minimize bias. We also summarize threats to segmentation accuracy, review common QC methods, and make recommendations for best practices and reporting in publications. Implementing the recommended QC practices will collectively improve inferences to the larger population, as well as have implications for clinical practice and public health. [ABSTRACT FROM AUTHOR]

Vaping use has skyrocketed especially among young adults, however there is no consensus on how vaping impacts the lungs. We aimed to determine whether there were changes in lung function acutely after a standard vaping session or if there were differences in lung function metrics between a healthy never‐vaping cohort (N = 6; 27.3 ± 3.0 years) and a young asymptomatic vaping cohort (N = 14; 26.4 ± 8.0 years) indicating chronic changes. Pulmonary function measurements and impulse oscillometry were obtained on all participants. Oxygen‐enhanced and Arterial Spin Labelling MRI were used to measure specific ventilation and perfusion, respectively, before and after vaping, and in the control cohort at baseline. MRI metrics did not show any significant differences in specific ventilation or perfusion after vaping. Heart rate increased post‐vaping (68.1 ± 10.5 to 71.3 ± 8.7, p = 0.020); however, this and other metrics did not show a nicotine dose‐dependent effect. There was a significant negative correlation between BMI and change in mean perfusion post‐vaping (p = 0.003); those with normal/low BMI showing an increase in perfusion and vice versa for high BMI. This may be due to subjects lying supine during vaping inhalation. Pulmonary function metrics indicative of airways resistance showed significant differences between the vaping and control cohorts indicating early airway changes. [ABSTRACT FROM AUTHOR]

Vagus nerve stimulation (VNS) is an established therapy for drug‐resistant epilepsy. However, there is a lack of reliable predictors of VNS response in clinical use. The identification of factors predictive of VNS response is important for patient selection and stratification as well as tailored stimulation programming. We conducted a narrative review of the existing literature on prognostic markers for VNS response using clinical, demographic, biochemical, and modality‐specific information such as from electroencephalography (EEG), magnetoencephalography, and magnetic resonance imaging (MRI). No individual marker demonstrated sufficient predictive power for individual patients, although several have been suggested, with some promising initial findings. Combining markers from underresearched modalities such as T1‐weighted MRI morphometrics and EEG may provide better strategies for treatment optimization. [ABSTRACT FROM AUTHOR]

Summary Background Objectives Study design Methods Results Main limitations Conclusions The presence of palmar osteochondral fragments of the distal phalanx is a newly recognised cause of foot lameness with only a few cases having been reported.To describe the low field magnetic resonance imaging (MRI) appearance of palmar articular fragmentation of the distal phalanx and concurrent abnormalities of the distal interphalangeal joint (DIPJ); to investigate the prevalence of these fragments in a population of sports and pleasure horses and their potential clinical significance.Retrospective descriptive case series.This is a retrospective descriptive case series in which all Sports and Pleasure horses undergoing standing low‐field MRI of the feet between 2015 and 2023 were reviewed. Appearance, location and number of palmar articular fragments were recorded. When a palmar fragment was present, abnormal findings of the DIPJ were graded.A total of 855 horses underwent MRI examination of one or both front feet. Palmar osteochondral fragmentation of the distal phalanx was identified in four horses (0.4% prevalence), three Lusitanos and one Warmblood. The age range was 4–17 years old. All fragments were located along the palmarolateral margin of the glenoid of the distal phalanx in front feet. Concurrent imaging abnormalities of the joint were present in all four horses.Lack of histopathology.The prevalence of palmar articular fragments of the distal phalanx was low in this population of horses. Palmar osteochondral fragmentation must be considered when evaluating lameness localised to the foot, since it was identified only in lame limbs and associated with other imaging abnormalities of the DIPJ. [ABSTRACT FROM AUTHOR]

Background Purpose Methods Results Conclusions In ovo MR presents a promising and viable alternative to traditional in vivo small animal experiments. Sodium MRI complements proton MRI by providing potential access to tissue cellular metabolism. Despite its abundance, sodium MRI is challenged by lower MR sensitivity and faster relaxation times compared to proton MRI. Ensuring a high signal‐to‐noise ratio and effective B0 shimming is essential. Double‐tuned coils combining 23Na and 1H are frequently employed to achieve structural imaging and efficient shim adjustment.This study introduces a novel, highly optimized, double‐tuned coil design, specifically for MR scans of chick embryos.A tapered‐spiral, double‐tuned coil was designed and constructed following careful consideration of design parameters. The performance of the coil was rigorously assessed through bench tests, and final validation was conducted on a 7 T MRI scanner using a chick embryo.Bench tests demonstrated that the return losses for both 1H and 23Na coils were better than − 30 dB, and isolation factors were better than − 21 dB, indicating that the double‐tuned coil was well‐set, with negligible coupling between channels. MR images of chick embryos, obtained using the coil, validated the feasibility of utilizing the design concept for in ovo applications.The innovative design of the proposed double‐tuned coil, characterized by its unique arrangement, offers improved performance. This design has the potential to significantly enhance the quality of in ovo 1H and 23Na measurements. [ABSTRACT FROM AUTHOR]

Background: POLIII‐related leukodystrophies are a group of recently recognized hereditary white matter diseases with a similar clinical and radiological phenotype. No Tunisian studies have been published about POLIII‐related leukodystrophy due to POLR3A variants. The aim of this study was to contribute to the clinical, radiological, and genetic characterization of POLR3A‐related leukodystrophy in a Tunisian cohort. Methods: We report six cases of genetically confirmed POLR3A‐related leukodystrophy belonging to six unrelated Tunisian families, along with a review of previously published pediatric cases. Results: All patients were born to consanguineous marriages and originated from the North or the Center of Tunisia. Age at onset varied between 15 months and 6 years. The clinical phenotype was similar in all patients with cerebellar ataxia, tremor, and nystagmus being the key features. Brain imaging showed diffuse hypomyelination in all patients with progressive cerebellar atrophy in three patients. Molecular analysis identified the same bi‐allelic NM_007055.4:c.2011T>C; p.(Trp671Arg) variant in the POLR3A gene in all patients. Conclusion: We hypothesize a founder effect for the identified variant given its recurrence in six unrelated individuals with a similar clinical phenotype. Given the apparent genetic homogeneity of Tunisian POLR3A patients, the recurrent variant should be directly targeted. This should facilitate diagnosis in index patients, and genetic counseling. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Concurrent recurrence of acute disseminated encephalomyelitis (ADEM) and poststreptococcal glomerulonephritis (PSGN) in a thalassemia intermedia patient is rare and underscores the complexity of autoimmune disorders. This case emphasizes the importance of considering ADEM in the differential diagnosis of children presenting with PSGN accompanied by neurological symptoms. Post‐streptococcal glomerulonephritis (PSGN) is a common group A streptococcal (GAS) infection sequela. The pathophysiology of PSGN involves immune complex deposition, with type 3 hypersensitivity reaction triggered by GAS. Certain neurological conditions may also arise following a GAS infection, possibly due to molecular mimicry in the brain, a pathophysiology similar to rheumatic fever, another common sequel of GAS infection. We present the case of a child with β‐thalassemia intermedia who exhibited the classic triad (edema, hypertension, hematuria) of PSGN along with neurological manifestations, including a low glasgow coma scale (GCS) score and seizures. Magnetic resonance imaging (MRI) of the brain indicated changes consistent with acute disseminated encephalomyelitis (ADEM). Initially treated with methylprednisolone, the patient eventually received intravenous immunoglobulin (IVIG) due to lack of response. The patient had a good outcome, with complete resolution of all symptoms and no residual neurological deficits. This case underscores the importance of considering ADEM in the differential diagnosis for patients presenting with neurological signs and symptoms following a recent throat infection with GAS. Furthermore, given the increased risk of infection in thalassemia, patients with thalassemia who have a throat infection and neurological symptoms should be evaluated for the possible presence of ADEM. [ABSTRACT FROM AUTHOR]

Background: The demographics and geography of Australia and New Zealand (ANZ), with few metropolitan centres and vast, sparsely populated rural areas, represent a challenge to providing equal care to all patients. This study aimed to compare rectal cancer care at rural and urban hospitals in ANZ. Methods: From the Bowel Cancer Outcomes Registry (BCOR, formerly known as the Bi‐National Colorectal Cancer Audit; BCCA), rectal cancer patients treated between 2007 and 2020 were compared based on hospital location (urban versus rural). Propensity‐score matching was performed to correct for differences in baseline characteristics between groups. Results: A total of 9385 rectal cancer patients were identified from the BCOR: 1329 (14.2%) were treated at rural hospitals and 8056 (85.8%) at urban hospitals. Propensity‐score matching resulted in 889 patients in each group, matched for age, ASA score, hospital type (public/private), tumour height from the anal verge, and pre‐treatment cT‐ and cAJCC‐stage. Rural patients had fewer pre‐treatment MRIs (67.9% versus 74.7%; P = 0.002), and underwent less neoadjuvant therapy (44.7% versus 50.9%; P = 0.01). Rural patients underwent fewer ULARs (39.4% versus 45.6%; P = 0.03), and fewer anastomoses were formed (67.9% versus 74.4%; P = 0.05). CRM rates and postoperative AJCC stages (P = 0.19) were similar between groups (P = 0.87). Fewer rural patients received adjuvant chemotherapy (37.8% versus 43.3%; P = 0.02). Conclusion: There are significant differences in pre‐treatment MRI rates, (neo)adjuvant treatment rates and surgical procedures performed between rectal cancer patients treated at rural and urban hospitals in ANZ, while CRM rates and postoperative AJCC stages are similar. [ABSTRACT FROM AUTHOR]

Background and purpose: Magnetic resonance imaging (MRI) scanners are a major contributor to greenhouse gas emissions from the healthcare sector, and efforts to improve energy efficiency and reduce energy consumption rely on quantification of the characteristics of energy consumption. The purpose of this work was to develop a semi‐automatic analytical methodology for the characterization of the energy consumption of MRI systems using only the load duration curve (LDC). LDCs are a fundamental tool used across various fields to analyze and understand the behavior of loads over time. Methods: An electric current transformer sensor and data logger were installed on two 3T MRI scanners from two vendors, termed M1 (outpatient scanner) and M2 (inpatient/emergency scanner). Data was collected for 1 month (7/11/2023 to 8/11/2023). Active power was calculated, assuming a balanced three‐phase system, using the average current measured across all three phases, a 480 V reference voltage for both machines, and vendor‐provided power factors. An LDC was constructed for each system by sorting the active power values in descending order and computing the cumulative time (in units of percentage) for each data point. The first derivative of the LDC was then computed (LDC'), smoothed by convolution with a window function (sLDC'), and used to detect transitions between different system modes including (in descending power levels): scan, prepared‐to‐scan, idle, low‐power, and off. The final, segmented LDC was used to measure time (% total time), total energy (kWh), and mean power (kW) for each system mode on both scanners. The method was validated by comparing mean power values, computed using the segmented 1‐month LDC, for each nonproductive system mode (i.e., prepared‐to‐scan, idle, lower‐power, and off) against power levels measured after a deliberate system shutdown was performed for each scanner (1 day worth of data). Results: The validation revealed differences in mean power values <1.4% for all nonproductive modes and both scanners. In the scan system mode, the mean power values ranged from 29.8 to 37.2 kW and the total energy consumed for 1 month ranged from 11 106 to 14 466 kWh depending on the scanner. Over the course of 1 month, the portion of time the scanners were in nonproductive modes ranged from 76% to 80% across scanners and the nonproductive energy consumption ranged from 8010 to 6722 kWh depending on the scanner. The M1 (outpatient) scanner consumed 99.9 and 183.9 kWh/day in idle mode for weekdays and weekends, respectively, because the scanner spent 23% more time proportionally in idle mode on the weekends. Conclusions: A semi‐automatic method for quantifying energy consumption characteristics of MRI scanners was introduced and validated. This method is relatively simple to implement as it requires only power data from the scanners and avoids the technical challenges associated with extracting and processing scanner log files. The methodology enables quantitative evaluation of the power, time, and energy characteristics of MRI scanners in scan and nonproductive system modes, providing baseline data and the capability of identifying potential opportunities for enhancing the energy efficiency of MRI scanners. [ABSTRACT FROM AUTHOR]

Laryngeal dystonia (LD) is an isolated, task‐specific, focal dystonia characterized by intermittent spasms of laryngeal muscles impairing speech production. Although recent studies have demonstrated neural alterations in LD, the consistency of findings across studies is not well‐established, limiting their translational applicability. We conducted a systematic literature search to identify studies reporting stereotactic coordinates of peak structural and functional abnormalities in LD patients compared to healthy controls, followed by a coordinate‐based activation likelihood estimation meta‐analysis. A total of 21 functional and structural neuroimaging studies, including 31 experiments in 521 LD patients and 448 healthy controls, met the study inclusion criteria. The multimodal meta‐analysis of these studies identified abnormalities in the bilateral primary motor cortices, the left inferior parietal lobule and striatum, the right insula, and the supplementary motor area in LD patients compared to healthy controls. The meta‐analytical findings reinforce the current view of dystonia as a neural network disorder and consolidate evidence for future investigations probing these targets with new therapies. [ABSTRACT FROM AUTHOR]

Introduction/Aims: Ryanodine receptor 1 (RYR1)‐related myopathies associated with variants in the RYR1 gene present with a wide range of symptoms and severity. Two of the milder phenotypes associated with dominant pathogenic variants in RYR1 are rhabdomyolysis and myalgia. Only a few studies have investigated the muscle function and structure of individuals with RYR1‐related rhabdomyolysis/myalgia objectively, showing inconsistent results. This study aimed to describe structural changes and contractility of muscles in individuals with RYR1‐related rhabdomyolysis/myalgia. Methods: We investigated 15 individuals with dominant variants in the RYR1‐gene and compared them with 15 age‐, sex‐, and body mass index (BMI)‐matched controls using MRI, stationary isokinetic dynamometry, and comprehensive clinical evaluation. Results: No significant differences were found between individuals with RYR1‐related rhabdomyolysis/myalgia and healthy controls in peak torque, fat fraction, cross‐sectional area, contractile cross‐sectional area, or contractility (p >.05) in muscles of the lower back (MRI data only), thigh, or calf. On clinical examination, three individuals exhibited weakness in hip or back extension on the Medical Research Council (MRC) test and eight had muscle hypertrophy. Individuals with weakness were not hypertrophic. Discussion: Most individuals with RYR1‐related rhabdomyolysis/myalgia have close to normal strength, and normal fat fraction and contractility of muscles, and therefore constitute a mild phenotype of RYR1‐related myopathies. [ABSTRACT FROM AUTHOR]

Introduction: Hepatocellular carcinoma (HCC) constitutes the majority of liver cancers and significantly impacts global cancer mortality. While ultrasound (US) with or without alpha‐fetoprotein is the mainstay for HCC surveillance, its limitations highlight the necessity for more effective surveillance tools. Therefore, this review explores evolving imaging modalities and abbreviated magnetic resonance imaging (MRI) (AMRI) protocols as promising alternatives, addressing challenges in HCC surveillance. Areas Covered: This comprehensive review delves into the evaluation and challenges of HCC surveillance tools, focusing on non‐contrast abbreviated MRI (NC‐AMRI) and contrast‐enhanced abbreviated MRI protocols. It covers the implementation of AMRI for HCC surveillance, patient preferences, adherence, and strategies for optimizing cost‐effectiveness. Additionally, the article provides insights into prospects for HCC surveillance by summarizing meta‐analyses, prospective studies, and ongoing clinical trials evaluating AMRI protocols. Expert Opinion: The opinions underscore the transformative impact of AMRI on HCC surveillance, especially in overcoming US limitations. Promising results from NC‐AMRI protocols indicate its potential for high‐risk patient surveillance, though prospective studies in true surveillance settings are essential for validation. Future research should prioritize risk‐stratified AMRI protocols and address cost‐effectiveness for broader clinical implementation, alongside comparative analyses with US for optimal surveillance strategies. [ABSTRACT FROM AUTHOR]

Summary: Pedicle screw loosening after posterior lumbar fusion is associated with poor bone quality, which often determines screw pull‐out strength, insertion torque, and vertebral body loading characteristics. Magnetic resonance imaging (MRI)‐based vertebral bone quality (VBQ) score were associated with poor bone quality. Current evidence suggests that pedicle bone quality (PBQ) has a greater impact on screw stability. However, the correlation between MRI‐based PBQ score and screw loosening has not been reported. Purpose: To introduce and evaluate an MRI‐based PBQ score to determine its effectiveness in predicting pedicle screw loosening following lumbar fusion surgery. Methods: The retrospective study analyzed 244 patients who underwent posterior lumbar interbody fusion (PLIF) with pedicle screws between December 2017 and December 2021, with CT and MRI imaging before surgery. Data collected included patient demographics and preoperative radiological data. Radiographic screw loosening was measured at 12 months postoperatively. Clinical assessments included pain visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. The PBQ score was measured using MRI scans. We use univariate analysis for preliminary screening of the risk factors of screw loosening. Subsequent analysis involved multivariate logistic regression to identify independent predictive factors for screw loosening. We constructed the receiver operating characteristic (ROC) curve to ascertain the discriminative capacity of the PBQ score. The area under the curve (AUC) quantified its predictive accuracy. Additionally, we evaluated the association between PBQ score and screw loosening using Spearman's correlation analysis. Results: Overall, 244 patients who underwent PLIF with pedicle screw fixation participated in this study, including 35 in the loosening group and 209 in the non‐loosening group. PBQ score in the loosening group was significantly higher than that in the non‐loosening group. On multivariate logistic regression, the higher PBQ score (OR = 8.481, 95% CI: 3.158–22.774; p < 0.001) and the lower mean Hounsfield unit (HU) value of L1‐4 (OR = 0.967, 95% CI 0.951–0.984; p < 0.001) were the variables that significantly predicted screw loosening. The AUC for the PBQ score and HU value were 0.751 (95% CI: 0.673–0.828) and 0.702 (95% CI: 0.612–0.791). The PBQ score optimal cutoff to differentiate patients with loosening and with non‐loosening was calculated as 3.045 with a sensitivity of 85.7% and specificity of 76.9%, while the optimal cutoff of the HU value was 151.5 with a sensitivity of 64.6% and specificity of 89.5%. Conclusions: The association between the PBQ score and the propensity for lumbar pedicle screw loosening was found to be substantial. As a predictive measure, the PBQ score outperformed the HU value in forecasting the likelihood of screw loosening post‐posterior lumbar fusion. [ABSTRACT FROM AUTHOR]

This study aims to understand the impact of the overall charge of Fe(III) chelates on their water exchange kinetics, thermodynamic stability, and kinetic inertia. To this end, we synthesized two CDTA‐amide ligands, each characterized by the replacement of one or two carboxyl groups with diethylamide functionalities. These alterations produced Fe(III) complexes with neutral or positively charged characteristics. The rate of water exchange (kex) was determined through a combined analysis of 1H relaxometric data and 1⁷O NMR chemical shift and transverse relaxation rate data. Additionally, we evaluated the thermodynamic stability and kinetic inertness of the complexes using potentiometry, UV‐Vis spectrophotometry, and capillary zone electrophoresis. Our results indicate that altering the charge of the complex slows down kex, consistent with previous observations for Gd(III) and Mn(II) chelates. Furthermore, the results indicate that incorporating amide donor groups decreases the stability of the complexes and reduces their kinetic inertia. However, both stability and kinetic inertia remain higher than those of [Fe(EDTA)]−. These findings provide some valuable insights for the development of Fe(III)‐based MRI probes alternative to those based on Gd(III). [ABSTRACT FROM AUTHOR]

Aim: To determine the role of preoperative MRI in the diagnosis and treatment of patients with granulosa cell tumors (GCTs) of the ovary. Materials and Methods: Twenty‐four patients who were operated on between 2018 and 2022 and who were pathologically diagnosed with GHT and met the inclusion criteria were retrospectively examined. The findings were compared with the patients' demographic data, symptoms, surgical findings (laterality, stage, lymph node involvement, endometrial pathology, tumor size), and CA‐125 levels. Results: The final cohort included 24 patients with a mean age of 54.71 ± 16.52. All the patients had the pathological diagnosis of adult type GCT. In the morphological evaluation, the most common finding was a solid‐cystic mixed type (14 patients, 58.3%), while intratumoral hemorrhage signal was observed in 10 patients (41.7%). In the majority of cases (91.7%), the mass showed regular contours. The honeycomb/Swiss cheese sign was detected in 54.2% of the cases. When the T1 and T2 signal of the solid component of the mass were examined relative to the myometrium, the majority of GCTs appeared isointense on both sequences (83.3% and 62.5%, respectively). The mean ADC value of the solid component obtained from diffusion‐weighted imaging was 0.78 ± 0.15 × 10−3. Pelvic fluid was observed in 41.7% of the cases. The average endometrial thickness was 9.74 ± 6.43 mm. Thickened endometrium more than 9 mm was observed in 9 out of the remaining 21 patients (42.9%). Conclusion: Understanding the key imaging features for GCTs plays an essential role in the diagnosis and guiding the treatment effectively. [ABSTRACT FROM AUTHOR]

Neuroimaging databases for neuro‐psychiatric disorders enable researchers to implement data‐driven research approaches by providing access to rich data that can be used to study disease, build and validate machine learning models, and even redefine disease spectra. The importance of sharing large, multi‐center, multi‐disorder databases has gradually been recognized in order to truly translate brain imaging knowledge into real‐world clinical practice. Here, we review MRI databases that share data globally to serve multiple psychiatric or neurological disorders. We found 42 datasets consisting of 23,293 samples from patients with psychiatry and neurological disorders and healthy controls; 1245 samples from mood disorders (major depressive disorder and bipolar disorder), 2015 samples from developmental disorders (autism spectrum disorder, attention‐deficit hyperactivity disorder), 675 samples from schizophrenia, 1194 samples from Parkinson's disease, 5865 samples from dementia (including Alzheimer's disease), We recognize that large, multi‐center databases should include governance processes that allow data to be shared across national boundaries. Addressing technical and regulatory issues of existing databases can lead to better design and implementation and improve data access for the research community. The current trend toward the development of shareable MRI databases will contribute to a better understanding of the pathophysiology, diagnosis and assessment, and development of early interventions for neuropsychiatric disorders. [ABSTRACT FROM AUTHOR]

Background: Compromised cerebral blood flow can contribute to future ischemic events in patients with symptomatic carotid artery disease. However, there is limited knowledge of the effects on cerebral hemodynamics resulting from a reduced internal carotid artery (ICA) blood flow rate (BFR). Purpose: Investigate how reduced ICA‐BFR, relates to BFR in the cerebral arteries. Study Type: Prospective. Subjects: Thirty‐eight patients, age 72 ± 6 years (11 female). Field Strength/Sequence: 3‐Tesla, four‐dimensional phase‐contrast magnetic resonance imaging (4D‐PCMRI). Assessment: Patients with ischemic stroke or transient ischemic attack were evaluated regarding the degree of stenosis. 4D‐PCMRI was used to measure cerebral BFR in 38 patients with symptomatic carotid stenosis (≥50%). BFR in the cerebral arteries was assessed in two subgroups based on symptomatic ICA‐BFR: reduced ICA‐flow (<160 mL/minutes) and preserved ICA‐flow (≥160 mL/minutes). BFR laterality was defined as a difference in the paired ipsilateral‐contralateral arteries. Statistical Tests: Patients were grouped based on ICA‐BFR (reduced vs. preserved). Statistical tests (independent sample t‐test/paired t‐test) were used to compare groups and hemispheres. Significance was determined at P < 0.05. Results: The degree of stenosis was not significantly different, 80% (95% confidence interval [CI] = 73%–87%) in the reduced ICA‐flow vs. 72% (CI = 66%–76%) in the preserved ICA‐flow; P = 0.09. In the reduced ICA‐flow group, a significantly reduced BFR was found in the ipsilateral middle cerebral artery and anterior cerebral artery (A1), while significantly increased in the contralateral A1. Retrograde BFR was found in the posterior communicating artery and ophthalmic artery. Significant BFR laterality was present in all paired arteries in the reduced ICA‐flow group, contrasting the preserved ICA‐flow group (P = 0.14–0.93). Data Conclusions: 4D‐PCMRI revealed compromised cerebral BFR due to carotid stenosis, not possible to detect by solely analyzing the degree of stenosis. In patients with reduced ICA‐flow, collaterals were not sufficient to maintain symmetrical BFR distribution to the two hemispheres. Evidence Level: 2 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

Deep learning presents a generalizable solution for motion correction requiring no pulse sequence modifications or additional hardware, but previous networks have all been applied to coil‐combined data. Multichannel MRI data provide a degree of spatial encoding that may be useful for motion correction. We hypothesize that incorporating deep learning for motion correction prior to coil combination will improve results. A conditional generative adversarial network was trained using simulated rigid motion artifacts in brain images acquired at multiple sites with multiple contrasts (not limited to healthy subjects). We compared the performance of deep‐learning‐based motion correction on individual channel images (single‐channel model) with that performed after coil combination (channel‐combined model). We also investigate simultaneous motion correction of all channel data from an image volume (multichannel model). The single‐channel model significantly (p < 0.0001) improved mean absolute error, with an average 50.9% improvement compared with the uncorrected images. This was significantly (p < 0.0001) better than the 36.3% improvement achieved by the channel‐combined model (conventional approach). The multichannel model provided no significant improvement in quantitative measures of image quality compared with the uncorrected images. Results were independent of the presence of pathology, and generalizable to a new center unseen during training. Performing motion correction on single‐channel images prior to coil combination provided an improvement in performance compared with conventional deep‐learning‐based motion correction. Improved deep learning methods for retrospective correction of motion‐affected MR images could reduce the need for repeat scans if applied in a clinical setting. [ABSTRACT FROM AUTHOR]

Purpose: Magnetization transfer saturation (MTsat) mapping is commonly used to examine the macromolecular content of brain tissue. This study compared variable flip angle (VFA) T1 mapping against compressed‐sensing MP2RAGE (csMP2RAGE) T1 mapping for accelerating MTsat imaging. Methods: VFA, MP2RAGE, and csMP2RAGE were compared against inversion‐recovery T1 in an aqueous phantom at 3 T. The same 1‐mm VFA, MP2RAGE, and csMP2RAGE protocols were acquired in 4 healthy subjects to compare T1 and MTsat. Bloch‐McConnell simulations were used to investigate differences between the phantom and in vivo T1 results. Ten healthy controls were imaged twice with the csMP2RAGE MTsat protocol to quantify repeatability. Results: The MP2RAGE and csMP2RAGE protocols were 13.7% and 32.4% faster than the VFA protocol, respectively. At these scan times, all approaches provided strong repeatability and accurate T1 times (< 5% difference) in the phantom, but T1 accuracy was more impacted by T2 for VFA than for MP2RAGE. In vivo, VFA estimated longer T1 times than MP2RAGE and csMP2RAGE. Simulations suggest that the differences in the T1 measured using VFA, MP2RAGE, and inversion recovery could be explained by the magnetization‐transfer effects. In the test–retest experiment, we found that the csMP2RAGE has a minimum detectable change of 2.3% for T1 mapping and 7.8% for MTsat imaging. Conclusions: We demonstrated that MP2RAGE can be used in place of VFA T1 mapping in an MTsat protocol. Furthermore, a shorter scan time and high repeatability can be achieved using the csMP2RAGE sequence. [ABSTRACT FROM AUTHOR]

Objective: Epileptic seizures occurring in late adulthood often remain of unknown origin. Sporadic cerebral amyloid angiopathy (CAA) is a cerebral small vessel disease characterized by intracerebral hemorrhage, microhemorrhage and superficial siderosis, occurring mostly in elderly. This observational case–control study aimed to assess the occurrence of CAA in patients experiencing their first seizure in late adulthood. Methods: We enrolled consecutive patients aged ≥55 years presenting with late‐onset seizures (LOS) to the emergency departments or outpatient clinics of two Italian centers, from April 2021 to October 2022. Two age‐matched control subjects with neurological symptoms other than epileptic seizure were recruited for each enrolled case. All participants underwent brain MRI (1.5 Tesla) including blood‐sensitive sequences and were assessed for probable CAA diagnosis according to Boston criteria 2.0. Chi‐squared test was performed to evaluate group differences. Univariate logistic regression analysis tested the association between clinical variables and CAA. Results: We included 65 patients with LOS (27 females; mean age 72.2 ± 8.9 years) and 130 controls (49 females; mean age 70.3 ± 8.9 years). Diagnosis of probable CAA was achieved in 10.8% (7/65) of LOS patients and 2.3% (3/130) controls, with a statistically significant difference (p = 0.011). The OR for CAA in the LOS group was 5.2 as compared to the control group (95% CI = 1.3–20.6, p = 0.02). Significance: The frequency of CAA is significatively higher in patients with LOS as compared to other neurological diseases, suggesting that a portion of LOS of unknown or vascular origin are associated with CAA. Plain Language Summary: Late‐onset seizures (LOS) are very frequent in the elderly and often have no clear cause. Cerebral amyloid angiopathy (CAA) is a condition where amyloid proteins build up in the blood vessels of the brain, causing them to become weak and prone to bleeding. In this study, we explored the occurrence of CAA in people with LOS. We found that people with LOS were more likely to have a diagnosis of CAA than controls (i.e., people with other neurological diseases). [ABSTRACT FROM AUTHOR]