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Objectives: To investigate the safety and tolerability of gadobutrol at the recommended dose in patients requiring contrast-enhanced magnetic resonance imaging/angiography (MRI/MRA) in the routine setting., Methods: GARDIAN prospectively enrolled 23,708 patients undergoing routine gadobutrol-enhanced MRI/MRA for approved indications at 272 study centres in Europe, Asia, North America, and Africa and monitored for adverse events., Results: Median gadobutrol dose was 0.11 mmol/kg body weight. The overall incidence of adverse drug reactions (ADRs) was 0.7 % (n = 170 patients), with similar incidences in patients with renal impairment or cardiac disease, from different geographic regions and in different gadobutrol dose groups. Patients at risk for contrast media reaction had an ADR incidence of 2.5 %. Five patients (0.02 %) experienced serious adverse events, four were drug-related. One patient experienced a fatal anaphylactoid shock, assessed to be related to injection of gadobutrol. The contrast quality of gadobutrol-enhanced images was rated by treating physicians as good or excellent in 97 % cases, with similar ratings in all patient subgroups and indications., Conclusions: The GARDIAN study shows that gadobutrol at the recommended dose is well tolerated across a large, diverse patient population., Key Points: • Gadobutrol at recommended dose shows low rates of adverse drug reactions • Gadobutrol demonstrates a uniform safety profile across diverse patient groups • Gadobutrol provides excellent contrast quality in routine practice.

Neuromyelitis optica (NMO) is an autoimmune disorder of the central nervous system that usually presents with acute myelitis and/or optic neuritis. Recently, some brain magnetic resonance imaging findings have been described in NMO that are important in the differential diagnosis. Pencil-thin, leptomeningeal, and cloud-like enhancement may be specific to NMO. These patterns are usually seen during relapses. Recognizing these lesions and enhancement patterns may expedite the diagnosis and allows early effective treatment. The purpose of this article is to review the latest knowledge and to share our experience with the contrast enhancement patterns of NMO brain lesions., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to test the hypothesis that bitemporal hemianopsia (BHA) is the most common visual field (VF) defect in patients with pituitary macroadenoma and to assess the degree of optic pathway compression necessary to produce visual defects., Materials and Methods: We reviewed the MRI findings and medical records of 119 patients with pituitary macroadenoma who had undergone formal assessment of VFs. We then evaluated the degree of optic pathway displacement caused by the pituitary macroadenoma, as observed on MR images. The classifications of optic pathway displacement included no contact, abutment but no displacement, mild displacement (< 3 mm), and moderate displacement (≥ 3 mm). Qualitative analysis classified VFs as normal or as having defects that were monocular, bitemporal, mixed (bitemporal with additional defects), homonymous, or nonspecific., Results: A total of 89 of 115 patients had an abnormal VF. Only one patient had true BHA. The most common defects were bitemporal or mixed defects (in 49 of 115 patients [42.6%]), likely because more than just the chiasm is often compressed by the pituitary macroadenoma. Classification of optic pathway displacement by the pituitary macroadenoma was as follows: 23 patients had no contact, eight had abutment but no displacement, 27 had mild displacement, and 57 had moderate displacement. In 78 of the 92 patients (84.8%) with pituitary macroadenoma that had contact with the optic pathway, contact was with the optic chiasm and the prechiasmal optic nerve. Of the 49 patients with bitemporal or mixed defects, 42 had moderate displacement of the optic pathway caused by their tumors., Conclusion: BHA is exceedingly uncommon in patients with pituitary macroadenoma. However, although bitemporal and mixed defects are the most common abnormal VF findings, they were found in only 42.6% of patients. Such defects rarely occur if the tumor displaces the optic pathway less than 3 mm from baseline.

Purpose: It is difficult to differentiate CNS lymphoma from other tumors such as malignant gliomas, metastases, or meningiomas with conventional MR imaging, because the imaging findings are overlapped between these tumors. The purpose of this study is to investigate the perfusion weighted MR imaging findings of CNS lymphomas and to compare the relative cerebral blood volume ratios between CNS lymphomas and other tumors such as high grade gliomas, metastases, or meningiomas., Materials and Methods: We retrospectively reviewed MRI findings and clinical records in 13 patients with pathologically proven CNS lymphoma between January 2006 and November 2008. We evaluated the relative cerebral blood volume ratios of tumor, which were obtained by dividing the values obtained from the normal white matter on MRI., Results: Total 13 patients (M:F=8:5; age range 46-67 years, mean age 52.3 years) were included. The CNS lymphomas showed relatively low values of maximum relative CBV ratio in most patients regardless of primary or secondary CNS lymphoma., Conclusion: Perfusion weighted image may be helpful in the diagnosis of CNS lymphoma in spite of primary or secondary or B cell or T cell., (Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.)

Purpose: The purpose of this study is to investigate the MRI findings of visceral larva migrans (VLS) of Toxocara canis in spinal cord., Materials and Methods: We retrospectively reviewed spinal MRI findings in eight patients with serologically proven Toxocara canis between 2005 and 2008. We evaluated the location, length, extent and migration of the lesion, MR signal intensity (SI), enhancement pattern, and swelling of the spinal cord. We evaluated clinical features including presenting symptoms and signs and treatment response., Results: Total 8 patients (M=8; age range 36-79 years) were included. The lesions were located in the cervical or thoracic spinal cord in all patients. All lesions showed high SI and minimal or mild swelling of involved spinal cord on T2WI and focal nodular enhancement on posterior or posterolateral segment of spinal cord. The length of involved lesion was relatively short in most patients. There was a migration of lesion in one patient. In spite of albendazole or steroid treatment, neurological symptoms or signs were not significantly improved in all patients., Conclusion: Although all lesions show non-specific imaging findings like non-tumorous myelopathy mimicking transverse myelitis, single lesion, focal nodular enhancement on posterior or posterolateral segment of spinal cord, relatively short segmental involvement and migration of lesion may be characteristic findings of spinal VLM of Toxocara canis. In addition, the reluctant response to the treatment may be characteristic of spinal VLM of Toxocara canis., (Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.)

Objective: The purpose of this study was to evaluate the signal intensity (SI) change of the labyrinth in patients with vestibular schwannoma on isotropic 3D fluid-attenuated inversion recovery (FLAIR) imaging at 3 T., Methods: Thirty-four patients with surgically confirmed or radiologically diagnosed vestibular schwannoma were included in this study. Retrospectively, we visually and quantitatively compared the SIs of the cochlea and vestibule on the affected side with those on the unaffected side. We also investigated whether there was correlation between the SI ratios (SIRs) of the labyrinth and the audiometric findings., Results: On 3D FLAIR images, the SI of the cochlea and vestibule on the affected side was significantly increased in 97% (33/34) and 91% (31/34), respectively. While the SI of the cochlea was diffusely increased, that of the vestibule was only partially increased. Quantitative study also revealed statistically significantly higher SIRs of the cochlea (0.99 +/- 0.29) and vestibule (0.73 +/- 0.31) on the affected side, compared with the cochlea (0.47 +/- 0.20) and vestibule (0.19 +/- 0.10) on the unaffected side. There was no significant correlation of the SIRs of the labyrinth with the degree of hearing loss., Conclusion: In patients with vestibular schwannoma, isotropic 3D FLAIR imaging is a useful method for the evaluation of the SI changes of the labyrinth.

Background: Oligodendrogliomas are primarily supratentorial tumors. However, infrequently, they can also arise from infratentorial structures. There are only limited numbers of radiological articles on the specific imaging findings of this entity., Purpose: To investigate the imaging findings of infratentorial oligodendrogliomas., Material and Methods: We retrospectively reviewed the magnetic resonance imaging (MRI) findings and clinical records of six patients with pathologically proven infratentorial oligodendrogliomas between December 1994 and April 2008. Tumor location, circumscription, signal intensity (SI), enhancement pattern, the presence of restricted diffusion, and the change of the relative cerebral blood volume (rCBV) on MRI were evaluated., Results: In total, six patients (three male, three female; mean age 65 years, range 51-75 years) were included. The pathology revealed anaplastic oligodendrogliomas in all six patients. The location was cerebellum in four patients, medulla in one patient, and fourth ventricle and tegmentum in one patient. Three of them were of the infiltrative type, and the other three of the mass-forming type. The solid component of the tumors showed high SI (n=6) on FLAIR and T2-weighted images, and low (n=5) or iso (n=1) SI on T1-weighted images. All infiltrative lesions showed multifocal patchy enhancement, and mass-forming lesions showed heterogeneous enhancement (n=2) and diffuse homogeneous enhancement (n=1). Three patients had restricted diffusion, and one had leptomeningeal seeding. There was markedly increased rCBV on perfusion-weighted image (PWI) in one patient. Calcification or hemorrhage was not found. Tumor progression after operation, radiation therapy, gamma-knife surgery, or chemotherapy developed in five patients., Conclusion: Although infratentorial oligodendrogliomas did not show characteristic imaging findings, there was a tendency toward multifocal heterogeneous enhancement and absent or mild mass effect of infiltrative lesions. Infratentorial oligodendrogliomas may be more malignant than supratentorial oligodendrogliomas.

Introduction: Sinonasal inverted papilloma (IP) is known for high rate of associated malignancy. The purpose of this study was to identify (18)F-FDG PET/CT findings of sinonasal IPs. We also tried to compare the PET/CT findings with the MR imaging findings., Methods: We retrospectively reviewed PET/CT and MR images of eight patients with sinonasal IP with (n = 6) or without (n = 2) coexistent squamous cell carcinoma (SCC). Particular attention was paid to correlate the PET/CT findings with the MR imaging findings in terms of area distribution of standard uptake values (SUVs) and a convoluted cerebriform pattern (CCP)., Results: In two benign IPs, the maximum SUVs measured 8.2 and 7.8, respectively (mean, 8.0). In both tumors, MR images demonstrated a diffuse CCP. In six IPs with coexistent SCC, the maximum SUVs ranged from 13.3 to 31.9 (mean +/- SD, 20.2 +/- 6.6). In these tumors, MR images demonstrated a diffuse CCP in two, a partial CCP in three, and no CCP in one. A wide discrepancy was noted between MR imaging and PET/CT in terms of area distribution of a CCP and SUVs., Conclusion: In sinonasal lesions with MR imaging features of IP, (18)F-FDG PET/CT demonstrating avid FDG uptake does not necessarily imply the presence of coexistent malignancy. In our small series, although IPs containing foci of SCC had consistently higher SUVs than IPs without SCC, the limited literature on this subject suggests that PET cannot be used reliably to make the distinction.

Background & aimsWe conducted an individual patient data meta-analysis to establish stiffness cut-off values for magnetic resonance elastography (MRE) in staging liver fibrosis and to assess potential confounding factors.MethodsA systematic review of the literature identified studies reporting MRE data in patients with NAFLD. Data were obtained from the corresponding authors. The pooled diagnostic cut-off value for the various fibrosis stages was determined in a two-stage meta-analysis. Multilevel modelling methods were used to analyse potential confounding factors influencing the diagnostic accuracy of MRE in staging liver fibrosis.ResultsEight independent cohorts comprising 798 patients were included in the meta-analysis. The area under the receiver operating characteristic curve (AUROC) for MRE in detecting significant fibrosis was 0.92 (sensitivity, 79%; specificity, 89%). For advanced fibrosis, the AUROC was 0.92 (sensitivity, 87%; specificity, 88%). For cirrhosis, the AUROC was 0.94 (sensitivity, 88%, specificity, 89%). Cut-offs were defined to explore concordance between MRE and histopathology: ≥F2, 3.14 kPa (pretest probability, 39.4%); ≥F3, 3.53 kPa (pretest probability, 24.1%); and F4, 4.45 kPa (pretest probability, 8.7%). In generalized linear mixed model analysis, histological steatohepatitis with higher inflammatory activity (odds ratio 2.448, 95% CI 1.180-5.079, p 120U/L) (odds ratio 3.388, 95% CI 1.577-7.278, p

Researchers generally agree that when upregulating and downregulating emotion, control regions in the prefrontal cortex turn up or down activity in affect-generating brain areas. However, the affective dial hypothesis that turning up and down emotions produces opposite effects in the same affect-generating regions is untested. We tested this hypothesis by examining the overlap between the regions activated during upregulation and those deactivated during downregulation in 54 male and 51 female humans. We found that upregulation and downregulation both recruit regulatory regions, such as the inferior frontal gyrus and dorsal anterior cingulate gyrus, but act on distinct affect-generating regions. Upregulation increased activity in regions associated with emotional experience, such as the amygdala, anterior insula, striatum, and anterior cingulate gyrus as well as in regions associated with sympathetic vascular activity, such as periventricular white matter, while downregulation decreased activity in regions receiving interoceptive input, such as the posterior insula and postcentral gyrus. Nevertheless, participants subjective sense of emotional intensity was associated with activity in overlapping brain regions (dorsal anterior cingulate, insula, thalamus, and frontal pole) across upregulation and downregulation. These findings indicate that upregulation and downregulation rely on overlapping brain regions to control and assess emotions but target different affect-generating brain regions.SIGNIFICANCE STATEMENT Many contexts require modulating ones own emotions. Identifying the brain areas implementing these regulatory processes should advance understanding emotional disorders and designing potential interventions. The emotion regulation field has an implicit assumption we call the affective dial hypothesis: both emotion upregulation and downregulation modulate the same emotion-generating brain areas. Countering the hypothesis, our findings indicate that up- and down-modulating emotions target different brain areas. Thus, the mechanisms underlying emotion regulation might differ more than previously appreciated for upregulation versus downregulation. In addition to their theoretical importance, these findings are critical for researchers attempting to target activity in particular brain regions during an emotion regulation intervention.

Previous research has shown associations between brain structure and resting state high-frequency heart rate variability (HF HRV). Age affects both brain structure and HF HRV. Therefore, we sought to examine the relationship between brain structure and HF HRV as a function of age. Data from two independent studies were used for the present analysis. Study 1 included 19 older adults (10 males, age range 62-78 years) and 19 younger adults (12 males, age range 19-37). Study 2 included 23 older adults (12 males; age range 55-75) and 27 younger adults (17 males; age range 18-34). The root-mean-square of successive R-R-interval differences (RMSSD) from ECG recordings was used as time-domain measure of HF HRV. MRI scans were performed on a 3.0-T Siemens Magnetom Trio scanner. Cortical reconstruction and volumetric segmentation were performed with the Freesurfer image analysis suite, including 12 regions as regions of interests (ROI). Zero-order and partial correlations were used to assess the correlation of RMSSD with cortical thickness in selected ROIs. Lateral orbitofrontal cortex (OFC) cortical thickness was significantly associated with RMSSD. Further, both studies, in line with previous research, showed correlations between RMSSD and anterior cingulate cortex (ACC) cortical thickness. Meta-analysis on adjusted correlation coefficients from individual studies confirmed an association of RMSSD with the left rostral ACC and the left lateral OFC. Future longitudinal studies are necessary to trace individual trajectories in the association of HRV and brain structure across aging.

The locus coeruleus (LC) is a key node of the sympathetic nervous system and suppresses parasympathetic activity that would otherwise increase heart rate variability. In the current study, we examined whether LC-MRI contrast reflecting neuromelanin accumulation in the LC was associated with high-frequency heart rate variability (HF-HRV), a measure reflecting parasympathetic influences on the heart. Recent evidence indicates that neuromelanin, a byproduct of catecholamine metabolism, accumulates in the LC through young and mid adulthood, suggesting that LC-MRI contrast may be a useful biomarker of individual differences in habitual LC activation. We found that, across younger and older adults, greater LC-MRI contrast was negatively associated with HF-HRV during fear conditioning and spatial detection tasks. This correlation was not accounted for by individual differences in age or anxiety. These findings indicate that individual differences in LC structure relate to key cardiovascular parameters.

The ability to regulate emotion is crucial to promote well-being. Evidence suggests that the medial prefrontal cortex (mPFC) and adjacent anterior cingulate (ACC) modulate amygdala activity during emotion regulation. Yet less is known about whether the amygdala-mPFC circuit is linked with regulation of the autonomic nervous system and whether the relationship differs across the adult lifespan. The current study tested the hypothesis that heart rate variability (HRV) reflects the strength of mPFC-amygdala interaction across younger and older adults. We recorded participants heart rates at baseline and examined whether baseline HRV was associated with amygdala-mPFC functional connectivity during rest. We found that higher HRV was associated with stronger functional connectivity between the amygdala and the mPFC during rest across younger and older adults. In addition to this age-invariant pattern, there was an age-related change, such that greater HRV was linked with stronger functional connectivity between amygdala and ventrolateral PFC (vlPFC) in younger than in older adults. These results are in line with past evidence that vlPFC is involved in emotion regulation especially in younger adults. Taken together, our results support the neurovisceral integration model and suggest that higher heart rate variability is associated with neural mechanisms that support successful emotional regulation across the adult lifespan.

Background: We previously demonstrated the validity of a regression model that included ethnicity as a novel predictor for predicting normative brain volumes in old age. The model was optimized using brain volumes measured with a standard tool FreeSurfer. Objective: Here we further verified the prediction model using newly estimated brain volumes from Neuro I, a quantitative brain analysis system developed for Korean populations. Methods: Lobar and subcortical volumes were estimated from MRI images of 1,629 normal Korean and 786 Caucasian subjects (age range 59–89) and were predicted in linear regression from ethnicity, age, sex, intracranial volume, magnetic field strength, and scanner manufacturers. Results: In the regression model predicting the new volumes, ethnicity was again a substantial predictor in most regions. Additionally, the model-based z-scores of regions were calculated for 428 AD patients and the matched controls, and then employed for diagnostic classification. When the AD classifier adopted the z-scores adjusted for ethnicity, the diagnostic accuracy has noticeably improved (AUC = 0.85, ΔAUC = + 0.04, D = 4.10, p < 0.001). Conclusions: Our results suggest that the prediction model remains robust across different measurement tool, and ethnicity significantly contributes to the establishment of norms for brain volumes and the development of a diagnostic system for neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Little has been reported about the association between cerebral hyperperfusion syndrome (CHS) and blood-brain barrier (BBB) disruption in human. We aimed to investigate the changes in permeability after bypass surgery in cerebrovascular steno-occlusive diseases using dynamic contrast-enhanced MRI (DCE-MRI) and to demonstrate the association between CHS and BBB disruption. This retrospective study included 36 patients (21 hemispheres in 18 CHS patients and 20 hemispheres in 18 controls) who underwent combined bypass surgery for moyamoya and atherosclerotic steno-occlusive diseases. DCE-MRI and arterial spin labeling perfusion-weighted imaging (ASL-PWI) were obtained at the baseline, postoperative state, and discharge. Perfusion and permeability parameters were calculated at the MCA territory (CBF(territorial), Ktrans(territorial), Vp(territorial)) and focal perianastomotic area (CBF(focal), Ktrans(focal), Vp(focal)) of operated hemispheres. As compared with the baseline, both CBF(territorial) and CBF(focal) increased in the postoperative period and decreased at discharge, corresponding well to symptoms in the CHS group. Vp(focal) was lower in the postoperative period and at discharge, as compared with the baseline. In the control group, no parameters significantly differed among the three points. In conclusion, Vp at the focal perianastomotic area significantly decreased in patients with CHS during the postoperative period. BBB disruption may be implicated in the development of CHS after bypass surgery. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticles (Fe3O4 NPs) have been intensively investigated because of their potential biomedical applications due to their high saturation magnetization. In this study, core–shell Fe3O4@C NPs (core = Fe3O4 NPs and shell = amorphous carbons, davg = 35.1 nm) were synthesized in an aqueous solution. Carbon coating terminated with hydrophilic –OH and –COOH groups imparted excellent biocompatibility and hydrophilicity to the NPs, making them suitable for biomedical applications. The Fe3O4@C NPs exhibited ideal relaxometric properties for T2 magnetic resonance imaging (MRI) contrast agents (i.e., high transverse and negligible longitudinal water proton spin relaxivities), making them exclusively induce only T2 relaxation. Their T2 MRI performance as contrast agents was confirmed in vivo by measuring T2 MR images in mice before and after intravenous injection. [ABSTRACT FROM AUTHOR]

BackgroundIt has recently been suggested that diffusion and perfusion MRI can identify subgroups likely to benefit or potentially be harmed by reperfusion therapies.Case reportWe investigated serial MRI data of two patients with occlusion of the proximal middle cerebral artery (MCA). In both cases, acute multiple cortical infarcts evident on diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) showed extensive areas of severe perfusion delays, indicating a malignant MRI profile. However, despite the malignant MRI profiles in these cases, no new ischemic lesions or hemorrhage evolved even in the presence of persistent arterial occlusion, and the patients recovered without sequelae.ConclusionsThese two cases suggest that time-domain PWI findings should be interpreted with caution in certain scenarios of acute ischemic stroke.

Adult-type diffuse glioma (grade 4) has infiltrating nature, and therefore local progression is likely to occur within surrounding non-enhancing T2 hyperintense areas even after gross total resection of contrast-enhancing lesions. Cerebral blood volume (CBV) obtained from dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) is a parameter that is well-known to be a surrogate marker of both histologic and angiographic vascularity in tumors. We built two nnU-Net deep learning models for prediction of early local progression in adult-type diffuse glioma (grade 4), one using conventional MRI alone and one using multiparametric MRI, including conventional MRI and DSC-PWI. Local progression areas were annotated in a non-enhancing T2 hyperintense lesion on preoperative T2 FLAIR images, using the follow-up contrast-enhanced (CE) T1-weighted (T1W) images as the reference standard. The sensitivity was doubled with the addition of nCBV (80% vs. 40%, P = 0.02) while the specificity was decreased nonsignificantly (29% vs. 48%, P = 0.39), suggesting that fewer cases of early local progression would be missed with the addition of nCBV. While the diagnostic performance of CBV model is still poor and needs improving, the multiparametric deep learning model, which presumably learned from the subtle difference in vascularity between early local progression and non-progression voxels within perilesional T2 hyperintensity, may facilitate risk-adapted radiotherapy planning in adult-type diffuse glioma (grade 4) patients. [ABSTRACT FROM AUTHOR]

Background: Little is known about the performance of abbreviated MRI (AMRI) for secondary surveillance of recurrent hepatocellular carcinoma (HCC) after curative treatment. Purpose: To evaluate the detection performance of AMRI for secondary surveillance of HCC after curative treatment. Study Type: Retrospective. Population: A total of 243 patients (183 men and 60 women; median age, 65 years) who underwent secondary surveillance for HCC using gadoxetic acid‐enhanced MRI after more than 2 year of disease‐free period following curative treatment, including surgical resection or radiofrequency ablation (RFA). Field Strength/Sequence: A 3.0 T/noncontrast AMRI (NC‐AMRI) (T2‐weighted fast spin‐echo, T1‐weighted gradient echo, and diffusion‐weighted images), hepatobiliary phase AMRI (HBP‐AMRI) (T2‐weighted fast spin‐echo, diffusion‐weighted, and HBP images), and full‐sequence MRI Assessment: Four board‐certified radiologists independently reviewed NC‐AMRI, HBP‐AMRI, and full‐sequence MRI sets of each patient for detecting recurrent HCC. Statistical Tests: Per‐lesion sensitivity, per‐patient sensitivity and specificity for HCC detection at each set were compared using generalized estimating equation. Results: A total of 42 recurred HCCs were confirmed in the 39 patients. The per‐lesion and per‐patient sensitivities did not show significant differences among the three image sets for either reviewer (P ≥ 0.358): per‐lesion sensitivity: 59.5%–83.3%, 59.5%–85.7%, and 59.5%–83.3%, and per‐patient sensitivity: 53.9%–83.3%, 56.4%–85.7%, and 53.9%–83.3% for NC‐AMRI, HBP‐AMRI, and full‐sequence MRI, respectively. Per‐lesion pooled sensitivities of NC‐AMRI, HBP‐AMRI, and full‐sequence MRI were 72.6%, 73.2%, and 73.2%, with difference of −0.6% (95% confidence interval: −6.7, 5.5) between NC‐AMRI and full‐sequence MRI and 0.0% (−6.1, 6.1) between HBP‐AMRI and full‐sequence MRI. Per‐patient specificity was not significantly different among the three image sets for both reviewers (95.6%–97.1%, 95.6%–97.1%, and 97.6%–98.5% for NC‐AMRI and HBP‐AMRI, respectively; P ≥ 0.117). Data Conclusion: NC‐AMRI and HBP‐AMRI showed no significant difference in detection performance to that of full‐sequence gadoxetic acid‐enhanced MRI during secondary surveillance for HCC after more than 2‐year disease free interval following curative treatment. Based on its good detection performance, short scan time, and lack of contrast agent‐associated risks, NC‐AMRI is a promising option for the secondary surveillance of HCC. Evidence Level: 3. Technical Efficacy: Stage 2. [ABSTRACT FROM AUTHOR]

Herein, biotin (Bio)‐conjugated poly(acrylic acid) (PAA)‐grafted ultrasmall gadolinium oxide nanoparticles (Bio‐PAA‐Gd2O3 NPs) were synthesized for enhanced tumor imaging using Bio as a tumor‐targeting ligand. The average particle diameter of Gd2O3 NPs was 2.1 nm. The Bio‐PAA‐Gd2O3 NPs exhibited excellent colloidal stability (i. e., no precipitation) and a high longitudinal water proton spin relaxivity (r1) of 23.8 s−1 mM−1 (r2/r1=1.6 and r2=transverse water proton spin relaxivity), which was ∼6 times higher than those of commercial Gd‐chelated magnetic resonance imaging (MRI) contrast agents. Cytotoxicity tests using two cell lines showed that the Bio‐PAA‐Gd2O3 NPs were almost non‐toxic up to the measured concentration of 500 μM Gd. The enhanced tumor imaging of the Bio‐PAA‐Gd2O3 NPs was demonstrated through their higher positive contrasts and longer contrast retention at the tumor after intravenous injection in T1 MR images, compared with those of the control PAA‐Gd2O3 NPs. [ABSTRACT FROM AUTHOR]

Objective: There are difficulties on removing migrated disc herniation (MDH) using a microscope. The purpose of this study was to introduce a unilateral biportal endoscopic (UBE) translaminar approach to treat up‐migrated lumbar disc herniation (LDH). Patients and Methods: A total of 12 patients from March 2021 to February 2022 with up‐migrated LDH were treated with a UBE translaminar approach. Clinical outcomes such as a visual analog scale (VAS) (back and leg pain) and MacNab criteria were assessed preoperative, postoperative, and 1 month after surgery. Results: Seven patients were diagnosed with high‐grade up‐migrated LDH, while five patients presented very‐high grade up‐migrated LDH. In all cases, the migrated LDH were removed completely and were confirmed by postoperative magnetic resonance imaging. The VAS for back pain were improved from 4.5 (SD = 3.1) to 2.0 (SD = 1.0) and 1.0 (SD = 1.0) for immediately postoperative and in 1‐month follow‐up, respectively, showing a statistically significant difference (p < 0.001). VAS for leg pain was 6.5 (SD = 2.5) preoperatively to 2.3 (SD = 1.1) and 0.8 (SD = 0.4) immediately postoperative and 1‐month follow‐up, respectively, also showing a significant difference (p < 0.001). According to the MacNab criteria, we observed excellent outcomes in 66.6% and good outcomes in 33.3%. Conclusion: The UBE translaminar approach showed a high success rate with high patient satisfaction for the management of up‐migrated LDH. It could be considered a feasible alternative surgical option to treat up‐migrated LDH. [ABSTRACT FROM AUTHOR]

In recent decades, magnetic nanoparticles (MNPs) have attracted considerable research interest as versatile substances for various biomedical applications, particularly as contrast agents in magnetic resonance imaging (MRI). Depending on their composition and particle size, most MNPs are either paramagnetic or superparamagnetic. The unique, advanced magnetic properties of MNPs, such as appreciable paramagnetic or strong superparamagnetic moments at room temperature, along with their large surface area, easy surface functionalization, and the ability to offer stronger contrast enhancements in MRI, make them superior to molecular MRI contrast agents. As a result, MNPs are promising candidates for various diagnostic and therapeutic applications. They can function as either positive (T1) or negative (T2) MRI contrast agents, producing brighter or darker MR images, respectively. In addition, they can function as dual-modal T1 and T2 MRI contrast agents, producing either brighter or darker MR images, depending on the operational mode. It is essential that the MNPs are grafted with hydrophilic and biocompatible ligands to maintain their nontoxicity and colloidal stability in aqueous media. The colloidal stability of MNPs is critical in order to achieve a high-performance MRI function. Most of the MNP-based MRI contrast agents reported in the literature are still in the developmental stage. With continuous progress being made in the detailed scientific research on them, their use in clinical settings may be realized in the future. In this study, we present an overview of the recent developments in the various types of MNP-based MRI contrast agents and their in vivo applications. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the effect of transforaminal epidural steroid injection (TFESI) in patients with lumbosacral disc herniation by comparing its effect between those diagnosed by clinical evaluation and plain radiography only (X-ray group) and those by additional magnetic resonance imaging (MRI) (MRI group). Additionally, we investigated the accuracy of the preliminary clinical assumption in the X-ray group using confirmative post-injection MRI. Patients and Methods: We retrospectively recruited 367 patients with back and radicular pain due to lumbosacral disc herniation from a single pain clinic. Among them, 201 and 166 patients were categorized into the X-ray and MRI groups, respectively. In the X-ray group, the pathological level assumed initially by clinical evaluation and plain radiography concurred with that confirmed later on post-injection MRI in 139 patients (corresponding group); the remaining 62 patients lacked this concurrence (non-corresponding group). The NRS scores and Macnab criteria results were compared between the X-ray and MRI groups as well as the corresponding and non-corresponding groups. Results: Both the X-ray and MRI groups showed significant reductions in the NRS scores at 2 and 10 weeks post-injection when compared with the pretreatment scores. However, no significant difference was noted between the groups in terms of the magnitude of clinical improvement assessed by successful reduction in the NRS or Macnab scores. Furthermore, similar results were obtained in the comparison between the corresponding and non-corresponding groups of the X-ray group. Conclusion: TFESI guarantees favorable clinical outcomes even in the absence of confirmative MRI in patients with back and radicular pain. The preemptive application of this procedure could be prioritized and justified in patients suspected of lumbosacral disc herniation based on clinical evaluation and plain radiography only without the preceding MRI verification. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) is increasingly used to diagnose focal and diffuse liver disorders. Despite their enhanced efficacy, liver-targeted gadolinium-based contrast agents (GBCAs) raise safety concerns owing to the release of toxic Gd3+ ions. A π-conjugated macrocyclic chelate, Mn-NOTA-NP, was designed and synthesized as a non-gadolinium alternative for liver-specific MRI. Mn-NOTA-NP exhibits an r1 relaxivity of 3.57 mM−1 s−1 in water and 9.01 mM−1 s−1 in saline containing human serum albumin at 3 T, which is significantly greater than the clinically utilized Mn2+-based hepatobiliary drug, Mn-DPDP (1.50 mM−1 s−1), and comparable with that of GBCAs. Furthermore, the in vivo biodistribution and MRI enhancement patterns of Mn-NOTA-NP were similar to those of the Gd3+-based hepatobiliary agent, Gd-DTPA-EOB. Additionally, a 0.05 mmol/kg dose of Mn-NOTA-NP facilitated high-sensitivity tumor detection with tumor signal enhancement in a liver tumor model. Ligand-docking simulations further indicated that Mn-NOTA-NP differed from other hepatobiliary agents in their interactions with several transporter systems. Collectively, we demonstrated that Mn-NOTA-NP could be a new liver-specific MRI contrast agent. [ABSTRACT FROM AUTHOR]

Gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) can detect early stages of hepatocellular carcinoma (HCC). However, the survival benefit of Gd-EOB-DTPA-enhanced MRI in the surveillance of patients with cirrhosis has not yet been determined. We explored whether the intermittent replacement of ultrasonography (USG) with Gd-EOB-DTPA-enhanced MRI during HCC surveillance improved the clinical outcomes of patients with cirrhosis. We performed a retrospective cohort study of 421 HCC patients who were newly diagnosed during surveillance. Of these patients, 126 (29.9%) underwent surveillance based on Gd-EOB-DTPA-enhanced MRI and USG (USG+MRI group). The patients (295, 70.1%) who did not undergo MRI during surveillance were referred to as the USG group. In the USG+MRI group, 120 (95.2%) of 126 patients were diagnosed with early-stage HCC, whereas 247 (83.7%) of 295 patients were diagnosed with early-stage HCC in the USG group (P = 0.009). The significantly longer overall survival and time to progression in patients in the USG+MRI group compared to the unmatched cohort USG group was consistently observed by inverse probability weighting and propensity score-matched analysis. Gd-EOB-DTPA-enhanced MRI combined surveillance improved the detection of early-stage HCC and clinical outcomes such as overall survival and the time to progression in patients with cirrhosis. [ABSTRACT FROM AUTHOR]

In this study, we designed, synthesized, and evaluated gadolinium compounds conjugated with flavonoids as potential theranostic agents for the treatment of inflammation. These novel theranostic agents combine a molecular imaging agent and one of three flavonoids (galangin, chrysin, and 7-hydroxyflavone) as anti-inflammatory drugs as a single integrated platform. Using these agents, MR imaging showed contrast enhancement (>10 in CNR) at inflamed sites in an animal inflammation model, and subsequent MR imaging used to monitor the therapeutic efficacy of these integrated agents revealed changes in inflamed regions. The anti-inflammatory effects of these agents were demonstrated both in vitro and in vivo. Furthermore, the antioxidant efficacy of the agents was evaluated by measuring their reactive oxygen species scavenging properties. For example, Gd-galangin at 30 μM showed a three-fold higher ROS scavenging of DPPH. Taken together, our findings provide convincing evidence to indicate that flavonoid-conjugated gadolinium compounds can be used as potentially efficient theranostic agents for the treatment of inflammation. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to develop a deep learning algorithm for detection of active inflammatory sacroiliitis in short tau inversion recovery (STIR) sequence MRI. Methods A total of 326 participants with axial SpA, and 63 participants with non-specific back pain (NSBP) were recruited. STIR MRI of the SI joints was performed and clinical data were collected. Region of interests (ROIs) were drawn outlining bone marrow oedema, a reliable marker of active inflammation, which formed the ground truth masks from which 'fake-colour' images were derived. Both the original and fake-colour images were randomly allocated into either the training and validation dataset or the testing dataset. Attention U-net was used for the development of deep learning algorithms. As a comparison, an independent radiologist and rheumatologist, blinded to the ground truth masks, were tasked with identifying bone marrow oedema in the MRI scans. Results Inflammatory sacroiliitis was identified in 1398 MR images from 228 participants. No inflammation was found in 3944 MRI scans from 161 participants. The mean sensitivity of the algorithms derived from the original dataset and fake-colour image dataset were 0.86 (0.02) and 0.90 (0.01), respectively. The mean specificity of the algorithms derived from the original and the fake-colour image datasets were 0.92 (0.02) and 0.93 (0.01), respectively. The mean testing dice coefficients were 0.48 (0.27) for the original dataset and 0.51 (0.25) for the fake-colour image dataset. The area under the curve of the receiver operating characteristic (AUC-ROC) curve of the algorithms using the original dataset and the fake-colour image dataset were 0.92 and 0.96, respectively. The sensitivity and specificity of the algorithms were comparable with the interpretation by a radiologist, but outperformed that of the rheumatologist. Conclusion An MRI deep learning algorithm was developed for detection of inflammatory sacroiliitis in axial SpA. [ABSTRACT FROM AUTHOR]

In the current report, we describe an interesting case of cervical juxtafacet that developed outside the intervertebral foramen, compressing the cervical medial branch and causing neuropathic pain in the posterior inferior neck pain. A 61‐year‐old woman visited a local pain clinic due to neuropathic pain with a tingling and burning nature (numeric rating scale [NRS]: 5 out of 10) on the left posterior inferior neck area for 4 months. Paresthesia was observed in the left posterior inferior neck area. On cervical radiography, segmental instability was observed at the C3–4 and C4–5 levels. Moreover, on the magnetic resonance imaging (MRI) of the cervical spine, a cyst (size: 1.3 cm × 0.7 cm × 1 cm) was outside the intervertebral foramen, contacting the left C4–5 facet joint and left C5 articular pillar. We thought that the compression of the left C5 medial branch by the cyst could cause the patient's pain. We conducted computed tomography (CT)‐guided percutaneous needle aspiration of a cervical juxtafacet cyst. An 18‐gauge needle was advanced under the guidance of CT into the largest portion of the cyst through a posterolateral oblique approach. Gelatinous mucoid fluid (approximately 0.5 cc) was aspirated. Immediately after the aspiration, 80% of the patient's pain was disappeared, and dysesthesia was completely disappeared. At the 1‐, 3‐, and 6‐month follow‐ups, the patient reported slight pain (NRS: 1) on the left posterior inferior neck. Cervical juxtafacet cysts can develop outside of the intervertebral foramen and spinal canal. Percutaneous needle aspiration can be a useful therapeutic tool for the treatment of such cysts. [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance imaging (MRI) is important in the management of axial spondyloarthritis (SpA). However, many MRI lesions are not exclusive to axial SpA. Further characterization of these lesions may lead to better clinical decisions. Objective: The objective of this study was to compare the frequency of individual spinal MRI lesions between axial SpA and noninflammatory back pain. The factors associated with individual lesions in participants with axial SpA were also determined. Design: This was a cross-sectional observational study. Methods: MRI lesions in 447 participants with axial SpA and 122 participants with noninflammatory back pain were compared using the propensity score adjustment method. Individual lesions included discovertebral lesions (DVL), Modic type 1 lesions, DVL without Modic type 1 lesions, facet joint lesions, costovertebral joint lesions, corner inflammatory lesions (CIL), and fatty corner lesions (FCL). The factors associated with the lesions were determined using regression analyses. Results: Among participants with axial SpA, 81.9% were HLA-B27-positive, 55.0% had radiographic axial SpA, and 60.5% had radiographic features of spinal damage (mSASSS >2). Almost half (48.6% in axial SpA versus 31.1% in noninflammatory back pain) had inflammatory lesions on spinal MRI. In propensity score matching with noninflammatory back pain, axial SpA had an increased occurrence of DVL without Modic type 1 lesion (OR = 3.43, p = 0.01), costovertebral lesion (OR = 11.89, p = 0.02), number of CIL (B = 1.19, p < 0.001), and number of FCL (B = 3.33, p < 0.001). Similar associations were found in the regression models in the radiographic axial SpA subgroup: DVL without Modic type 1 lesion (OR = 2.46, p = 0.001), costovertebral lesion (OR = 3.86, p < 0.001), number of CIL (B = 1.13, p < 0.001), and FCL (B = 2.29, p < 0.01). Conclusion: MRI lesions including DVL without Modic type 1, costovertebral joint lesions, CIL, and FCL were more specific in axial SpA. [ABSTRACT FROM AUTHOR]

Hydrophilic and biocompatible PAA-coated ultrasmall Gd2O3 nanoparticles (davg = 1.7 nm) were synthesized and conjugated with tumor-targeting ligands, i.e., cyclic arginylglycylaspartic acid (cRGD) and/or folic acid (FA). FA-PAA-Gd2O3 and cRGD/FA-PAA-Gd2O3 nanoparticles were successfully applied in U87MG tumor-bearing mice for tumor imaging using T1 magnetic resonance imaging (MRI). cRGD/FA-PAA-Gd2O3 nanoparticles with multiple tumor-targeting ligands exhibited higher contrasts at the tumor site than FA-PAA-Gd2O3 nanoparticles with mono tumor-targeting ligands. In addition, the cRGD/FA-PAA-Gd2O3 nanoparticles exhibited higher contrasts in all organs, especially the aorta, compared with those of the FA-PAA-Gd2O3 nanoparticles, because of the blood cell hitchhiking effect of cRGD in the cRGD/FA-PAA-Gd2O3 nanoparticles, which prolonged their circulation in the blood. [ABSTRACT FROM AUTHOR]

Background: We compared the ability of head computed tomography (HCT) and MRI, respectively, obtained before or after target temperature management to predict neurologic outcomes in out-of-hospital cardiac arrest (OHCA) survivors.Methods: This retrospective study included adult comatose OHCA survivors who underwent neuroimaging scans within 6 h (first HCT) or 72-96 h (second HCT and MRI) after the return of spontaneous circulation (ROSC). We calculated the gray-white matter ratio (GWR), hypoxic-ischemic brain injury presence (loss of boundary at the basal ganglia level [LOB at BG], sulcal effacement at the centrum semiovale [SE at CS], and pseudo-SAH sign), and the overall score based on MRI findings (a total score of 21 brain regions individually scored according to the degree of signal abnormality).Results: Overall, 78 patients were included in this analysis, of whom 45 (58%) showed poor outcomes. The second HCT scan showed greater prognostic performance than the first HCT scan for GWR (area under curve 0.92 vs. 0.70), LOB at BG (0.93 vs. 0.65), SE at CS (0.89 vs. 0.64), and pseudo-SAH sign (0.75 vs. 0.51). The overall score on MRI (0.99) showed the highest prognostic performance. However, on the second HCT scan, the combination of GWR and LOB at BG showed prognostic performance (0.96) comparable to the overall score on MRI (P = 0.12); the corresponding sensitivity and specificity values were 85.7% and 100%.Conclusions: Overall score on MRI and the combination of GWR and LOB at BG findings on second HCT scans may help predict poor outcomes in OHCA survivors. [ABSTRACT FROM AUTHOR]

Background: Physical activities (PA) have been suggested to reduce the risk of Alzheimer's disease (AD) dementia. However, information on the neuropathological links underlying the relationship is limited.Objective: We investigated the role of midlife and late-life PA with in vivo AD neuropathologies in old adults without dementia.Methods: This study included participants from the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer's disease (KBASE). The participants underwent comprehensive clinical and neuropsychological assessment, [11C] Pittsburgh Compound B positron emission tomography (PET), [18F] fluorodeoxyglucose PET, and magnetic resonance imaging. Using the multi-modal brain imaging data, in vivo AD pathologies including global amyloid deposition, AD-signature region cerebral glucose metabolism (AD-CM), and AD-signature region cortical thickness (AD-CT) were quantified. Both midlife and late-life PA of participants were measured using the Lifetime Total Physical Activity Questionnaire.Results: This study was performed on 260 participants without dementia (195 with normal cognitive function and 65 with mild cognitive impairment). PA of neither midlife nor late-life showed direct correspondence with any neuroimaging biomarker. However, late-life PA moderated the relationship of brain amyloid-β (Aβ) deposition with AD-CM and AD-CT. Aβ positivity had a significant negative effect on both AD-CM and AD-CT in individuals with lower late-life PA, but those with higher late-life PA did not show such results. Midlife PA did not have such a moderation effect.Conclusion: The findings suggest that physically active lifestyle in late-life, rather than that in midlife, may delay AD-associated cognitive decline by decreasing Aβ-induced neurodegenerative changes in old adults. [ABSTRACT FROM AUTHOR]

Objective: Using diffusion‐weighted imaging (DWI)‐derived apparent diffusion coefficient (ADC), we aimed to determine the relationship between intensity of spinal inflammation and mobility in patients with axial spondyloarthritis (SpA) in early and later stages of active disease. The Ankylosing Spondylitis Disease Activity Score (ASDAS) was also used for a more comprehensive evaluation. Methods: Participants with axial SpA and back pain were recruited from 10 rheumatology centers. Clinical, biochemical and radiological parameters were collected. Short tau inversion recovery (STIR) sequence magnetic resonance imaging (MRI) and DWI of the spine and sacroiliac (SI) joints were performed. ADC maps were generated. Participants were examined for Bath Ankylosing Spondylitis Metrology Index (BASMI). Linear regression models were used to determine associations between BASMI and various clinical, radiological, and MRI parameters in participants with active inflammation on spinal ADC maps. Results: One‐hundred and twenty‐seven participants were included in the analyses. Multivariate linear regression showed that mean ADC spine (ß =.16; P =.03), ASDAS‐C‐reactive protein (CRP) (ß =.29, P <.001), and ASDAS‐erythrocyte sedimentation rate (ESR) (ß =.25, P <.01) were associated with BASMI. In participants with duration of back pain ≤3 years, mean spine ADC (ß =.37; P =.03), ASDAS‐CRP (ß =.44; P =.01), and ASDAS‐ESR (ß =.42; P =.01) were associated with BASMI after adjustment for confounding factors. In participants with duration of back pain >3 years, only ASDAS‐CRP (ß =.25; P <.01) and ASDAS‐ESR (ß =.20; P =.20) were associated with BASMI. Conclusion: Intensity of inflammation and clinical disease activity were independently associated with impairment of spinal mobility. The associations were stronger in early (≤3 years) than later disease. [ABSTRACT FROM AUTHOR]