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Developing T1-weighted magnetic resonance imaging (MRI) contrast agents with enhanced biocompatibility and targeting capabilities is crucial owing to concerns over current agents' potential toxicity and suboptimal performance. Drawing inspiration from "biomimetic camouflage," we isolated cell membranes (CMs) from human glioblastoma (T98G) cell lines via the extrusion method to facilitate homotypic glioma targeting. At an 8:1 mass ratio of ferric chloride hexahydrate to gallic acid (GA), the resulting iron (Fe)-GA nanoparticles (NPs) proved effective as a T1-weighted MRI contrast agent. T98G CM-coated Fe-GA NPs demonstrated improved homotypic glioma targeting, validated through Prussian blue staining and in vitro MRI. This biomimetic camouflage strategy holds promise for the development of targeted theranostic agents in a safe and effective manner., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Chen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The hip cartilage and labrum, as the main targets of femoroacetabular impingement, sports-related or traumatic damage, as well as congenital and developmental abnormalities, have attracted increasing attention with the development of magnetic resonance imaging (MRI) and hip arthroscopy. MRI is a commonly used imaging modality to noninvasively visualize the hip cartilage and labral lesions. However, conventional orthogonal MRI planes encounter unique challenges given the ball-and-socket configuration of the hip joint, its anatomically abducted and anteverted orientation, and the thin, closely apposed cartilage enveloping the femoral head and acetabulum. Advancements in hip MRI's radial plane, which is acquired through the center of the hip joint, offer a solution. This technology provides true cross-sectional images of the cartilage and labrum perpendicular to the curvature of the joint, thereby mitigating the partial-volume-averaging effects. The integration of 3.0-Tesla high field strength and three-dimensional (3D) acquisition techniques further enhances the capabilities of the radial plane. This combination yields a high signal-to-noise ratio, high spatial resolution, high contrast between intraarticular structures, while minimizing partial-volume-averaging effects. Such improvements potentially facilitate the comprehensive detection of even minor chondral and labral lesions. The capability for multiplanar reconstruction from a single 3D volumetric acquisition further strengthens the usefulness of the radial plane by aiding in precise localization of hip cartilage and labral lesions, in line with hip arthroscopy findings. These advancements have the potential to standardize MRI evaluations and radiographic reporting systems for hip cartilage and labrum, offering precise guidance for hip arthroscopy. This article presents a comprehensive review of radial plane technology applied to the hip MRI, and discusses the morphological assessment and localization of hip cartilage and labral lesions utilizing this advanced imaging technique. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 2., (© 2023 International Society for Magnetic Resonance in Medicine.)

Create a virtual ArcCHECK-MR phantom, customized for a 1.5T MR-linac, with consideration of the different density regions within the quality assurance (QA) phantom, aiming to streamline the utilization of this specialized QA device. A virtual phantom was constructed in the treatment planning system (TPS) to replicate the ArcCHECK-MR's composition, consisting of five distinct layers: "Outer" (representing the outer PMMA ring), "Complex" (simulating the printed circuit boards), "Detectors" (encompassing the detector area), "Inner" (signifying the inner PMMA ring) and "Insert" (representing the PMMA insert). These layers were defined based on geometric data and represented as contour points on a set of dummy CT images. Additionally, a setup platform was integrated as contoured structures. To determine the relative electron density (RED) values of the external and internal PMMA components, measurements were taken at 25 points in the insert using an ion chamber. A novel method for establishing the exit/entrance dose ratio (EEDR) for ArcCHECK-MR was introduced. The RED of higher density region was derived by evaluating the local gamma index passing rate results with criteria of 2% dose difference and 2 mm distance-to-agreement. The performance of the virtual phantom was assessed for Unity 7 FFF beams with a 1.5T magnetic field. The radii of the five ring structures within the virtual phantom measured 133.0 mm, 110.0 mm, 103.4 mm, 100.0 mm, and 75.0 mm for the "Outer," "Complex," "Detectors," "Inner" and "Insert" regions, respectively. The RED values were as follows: ArcCHECK-MR PMMA had a RED of 1.130, "Detectors" were assumed to have a RED of 1.000, "Complex" had a RED of 1.200, and the setup QA phantom justified a RED of 1.350. Early validation results demonstrate that the 5-layer virtual phantom, when compared to the commonly used bulk overridden phantom, offers improved capability in MR-linac environments. This enhancement led to an increase in passing rates for the local gamma index by approximately 5 ∼ 6%, when applying the criteria of 2%, 2 mm. We have successfully generated a virtual representation of the distinct regions within the ArcCHECK-MR using a TPS, addressing the challenges associated with its use in conjunction with a 1.5T MR-linac. We consistently observed favorable local gamma index passing rates across two 1.5T MR-linac and ArcCHECK-MR unit combinations. This approach has the potential to minimize uncertainties in the creation of the QA phantom for ArcCHECK-MR across various institutions., (© 2024 The Authors. Journal of Applied Clinical Medical Physics is published by Wiley Periodicals, Inc. on behalf of The American Association of Physicists in Medicine.)

Objectives: To evaluate the identification of tumor deposits (TDs) and the prognostic significance of an MRI tumor regression grade for TDs in patients with rectal cancer treated with neoadjuvant chemoradiotherapy (nCRT)., Methods: Ninety-one patients with cT3 or cT4 rectal cancer who underwent surgery following nCRT between August 2014 and June 2020 were retrospectively analyzed. Changes in pre-nCRT MRI-detected TDs (mrTDs) were described as mrTD regression grade. The diagnostic performance of post-nCRT MRI-detected TDs (ymrTDs) was compared with histopathological reference standard. The correlation between ymrTDs, mrTD regression grade, and disease-free survival (DFS) was assessed., Results: The sensitivity and specificity of ymrTDs were 88.00% and 89.39%, respectively. The area under the receiver operating characteristic curve was 0.887 (95% confidence interval [CI]: 0.803-0.944). The 3-year DFS of patients with positive ymrTDs was significantly lower than of the negative group (44.83% vs 82.73%, p < 0.001). The 3-year DFS was 33.33% for patients with poor regression of mrTDs following nCRT and 55.56% for those with moderate regression, compared to 69.23% in good responders and 83.97% in patients without mrTDs (p < 0.001). On multivariable Cox regression, mrTD regression grade was the only independent MRI factor associated with DFS (p = 0.042)., Conclusions: Diagnostic performance of ymrTDs was moderate. The mrTD regression grade was independently correlated with DFS, which may have a prognostic implication for treatment and follow-up., Clinical Relevance Statement: Patients with poor regression of MRI-detected tumor deposits may benefit from more aggressive treatments, such as chemoradiation therapy plus induction or consolidation chemotherapy., Key Points: • MRI provides a preoperative and noninvasive way to visualize tumor deposits (TDs) after neoadjuvant chemoradiotherapy (nCRT). • Post-nCRT MRI-detected TDs are a poor prognostic marker in cT3 and cT4 rectal cancer patients. • The regression of MRI-detected TDs after nCRT is associated with an improved disease-free survival., (© 2023. The Author(s), under exclusive licence to European Society of Radiology.)

Purpose: To investigate the influence of deep learning reconstruction (DLR) on bladder MRI, specifically examination time, image quality, and diagnostic performance of vesical imaging reporting and data system (VI-RADS) within a prospective clinical cohort., Methods: Seventy participants with bladder cancer who underwent MRI between August 2022 and February 2023 with a protocol containing standard T2-weighted imaging (T2WI S ), standard diffusion-weighted imaging (DWI S ), fast T2WI with DLR (T2WI DL ), and fast DWI with DLR (DWI DL ) were enrolled in this prospective study. Imaging quality was evaluated by measuring signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and qualitative image quality scoring. Additionally, the apparent diffusion coefficient (ADC) of bladder lesions derived from DWI S and DWI DL was measured and VI-RADS scoring was performed. Paired t-test or paired Wilcoxon signed-rank test were performed to compare image quality score, SNR, CNR, and ADC between standard sequences and fast sequences with DLR. The diagnostic performance for VI-RADS was assessed using the area under the receiver operating characteristic curve (AUC)., Results: Compared to T2WI S and DWI S , T2WI DL and DWI DL reduced the acquisition time from 5:57 min to 3:13 min and showed significantly higher SNR, CNR, qualitative image quality score of overall image quality, image sharpness, and lesion conspicuity. There were no significant differences in ADC and AUC of VI-RADS between standard sequences and fast sequences with DLR., Conclusions: The application of DLR to T2WI and DWI reduced examination time and significantly improved image quality, maintaining ADC and the diagnostic performance of VI-RADS for evaluating muscle invasion in bladder cancer., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: To investigate the value of magnetic resonance imaging (MRI)-based radiomics in predicting the treatment response to concurrent chemoradiotherapy (CCRT) in patients with locally advanced cervical squamous cell cancer (LACSC)., Methods: In total, 198 patients (training: n = 138; testing: n = 60) with LACSC treated with CCRT between January 2014 and December 2019 were retrospectively enrolled in this study. Responses were evaluated by MRI and clinical data performed at one month after completion of CCRT according to RECIST standards, and patients were divided into the residual group and nonresidual group. Overall, 200 radiomics features were extracted from T2-weighted imaging and apparent diffusion coefficient maps. The radiomics score (Rad-score) was constructed with a feature selection strategy. Logistic regression analysis was used for multivariate analysis of radiomics features and clinical variables. The performance of all models was assessed using receiver operating characteristic curves., Results: Among the clinical variables, tumor grade and FIGO stage were independent risk factors, and the areas under the curve (AUCs) of the clinical model were 0.741 and 0.749 in the training and testing groups. The Rad-score, consisting of 4 radiomics features selected from 200 radiomics features, showed good predictive performance with an AUC of 0.819 in the training group and 0.776 in the testing group, which were higher than the clinical model, but the difference was not statistically significant. The combined model constructed with tumor grade, FIGO stage, and Rad-score achieved the best performance, with an AUC of 0.857 in the training group and 0.842 in the testing group, which were significantly higher than the clinical model., Conclusion: MRI-based radiomics features could be used as a noninvasive biomarker to improve the ability to predict the treatment response to CCRT in patients with LACSC., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The study aimed to explore the application value of MRI images based on the optimized self-adaptive edge detection algorithm in the diagnosis of placenta previa and in the prediction of postpartum hemorrhage. Specifically, a self-adaptive edge detection algorithm was constructed based on optimized edge operators, with the nearest scale parameters analyzed. It was then used to process the MRI images of 36 patients with placenta previa. MRI images of different types of placenta previa were analyzed. The results found that the placenta of the complete placenta previa was attached to the lower wall of the uterus and covered the internal cervix in U shape, and the placenta adhered to the anterior and lower wall of the uterus, with widespread placenta accreta noted. With the results of cesarean section as the standard, it was observed that 2 cases of complete placenta previa were diagnosed as partial placenta previa. The diagnostic accuracy rate was 94.44%, which was not notably different from the results of cesarean section ( p > 0.05). The postpartum hemorrhage rate and hysterectomy rate of complete placenta previa were higher than partial placenta previa and marginal placenta previa, and the difference was notable ( p < 0.05), but no notable differences were noted in placenta adhesion, placenta accreta, neonatal death, and neonatal asphyxia between the three types of placenta previa ( p > 0.05). The incidence of thinned myometrium, placenta penetrating the cervix, placenta accreta, and uneven placental signal in patients with postpartum hemorrhage was higher versus those without postpartum hemorrhage, and the difference was notable ( p < 0.05). In a word, MRI images based on the self-adaptive edge detection algorithm can clearly show the status of placenta previa and exhibit better diagnosis effects and a higher accuracy rate. The thinned myometrium, the placenta penetrating the cervix, placenta accreta, and uneven placental signal may be the related risk factors for postpartum hemorrhage in patients with placenta previa., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Yan Chen and Ting Xu.)

Calcification causes mixed signal intensity in the lymph node (LN) on high-resolution magnetic resonance imaging (MRI), which is a strong indicator of regional LN metastasis in rectal cancer. Calcified metastatic LNs in rectal cancer commonly display scattered fine punctate calcifications to varying degrees on computed tomography (CT). On high-resolution MRI, the calcifications manifest a patchy area of signal loss in corresponding calcified area that is larger than on CT. It is necessary to recognize the appearance of metastatic LN calcifications on high-resolution MRI in rectal cancer because it is the primary imaging method for local staging in rectal cancer. This pictorial essay aims to introduce an important imaging finding that can contribute to the diagnosis of LN metastasis by illustrating features and differences between CT and high-resolution MRI of metastatic LN calcifications in rectal cancer.

A single-atom metal doped on carbonaceous nanomaterials has attracted increasing attention due to its potential applications as high-performance catalysts. However, few studies focus on the applications of such nanomaterials as nanotheranostics for simultaneous bioimaging and cancer therapy. Herein, it is pioneeringly demonstrated that the single-atom Gd anchored onto graphene quantum dots (SAGd-GQDs), with dendrite-like morphology, was successfully prepared. More importantly, the as-fabricated SAGd-GQDs exhibits a robustly enhanced longitudinal relaxivity ( r 1 = 86.08 mM -1 s -1 ) at a low Gd 3+ concentration of 2 μmol kg -1 , which is 25 times higher than the commercial Gd-DTPA ( r 1 = 3.44 mM -1 s -1 ). In vitro and in vivo studies suggest that the obtained SAGd-GQDs is a highly potent and contrast agent to obtain high-definition MRI, thereby opening up more opportunities for future precise clinical theranostics.

In this study, we assess the dosimetric qualities and usability of planning for 1.5 T MR-Linac based intensity modulated radiotherapy (MRL-IMRT) for various clinical sites in comparison with IMRT plans using a conventional linac. In total of 30 patients with disease sites in the brain, esophagus, lung, rectum and vertebra were re-planned retrospectively for simulated MRL-IMRT using the Elekta Unity dedicated treatment planning system (TPS) Monaco (v5.40.01). Currently, the step-and-shoot (ss) is the only delivery technique for IMRT available on Unity. All patients were treated on an Elekta Versa HD TM with IMRT using the dynamic multileaf collimator (dMLC) technique, and the plans were designed using Monaco v5.11. For comparison, the same dMLC-IMRT plan was recalculated with the same machine and TPS but only changing the technique to step-and-shoot. The dosimetric qualities of the MRL-IMRT plans, to be evaluated by the Dose Volume Histograms (DVH) metrics, Homogeneity Index and Conformality Index, were compared with the clinical plans. The planning usability was measured by the optimization time and the number of Monitor Units (MUs). Comparing MRL-IMRT with conventional linac based plans, all created plans were clinically equivalent to current clinical practice. However, MRL-IMRT plans had higher dose to skin and larger low dose region of normal tissues. Furthermore, MRL-IMRT plans had significantly reduced optimization time by comparing conventional linac based plans. The number of MUs of MRL-IMRT was increased by 23% compared with ss-IMRT, and no difference from dMLC-IMRT. In conclusion, clinically acceptable plans can be achieved with 1.5 T MR-Linac system for multiple tumor sites. Given the differences in machine characteristics, some minor differences in plan quality were found between MR-Linac plans and current clinical practice and this should be considered in clinical practice.

Objective: Hip cartilage quality is essential for the success of joint-preserving surgery for osteonecrosis. This study aimed to characterize cartilage changes in osteonecrosis of femoral head (ONFH) using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC)., Design: Fifteen asymptomatic (control) and 60 ONFH subjects were included in this study. The ONFH subjects were stratified in accordance with the Association Research Circulation Osseous (ARCO) classification ( n = 15 hips per ARCO stage). All participant hips were investigated using dGEMRIC and theT1Gd data were collected and analyzed., Results: T1Gd value was significantly lower in the ONFH group (365.1 ± 90.5 ms; range 200-498 ms) compared with the control group (546.1 ± 26.0 ms; range 504-580 ms) ( P < 0.001). The T1Gd values of ARCO stage I-IV ONFH were 460.2 ± 17.3 ms (439-498 ms), 408.9 ± 43.4 ms (337-472 ms), 359.9 ± 34.5 ms (303-412 ms), 231.5 ± 15.1 ms (200-253 ms), respectively. Decreased T1Gd value was found to correlate significantly with increased ONFH severity ( P < 0.001). T1Gd value in collapse stage was significantly lower than that of noncollapse stage (295.7 ± 70.3 ms [range 200-412 ms] vs. 434.6 ± 41.7 ms [range 337-498 ms]; P < 0.001)., Conclusions: dGEMRIC identified hip cartilage as abnormal in ONFH, even at early-stage, as represented by decreased T1Gd, and this was further aggravated by ONFH collapse.

OBJECTIVE. The purpose of this study was to use quantitative dynamic contrast-enhanced MRI (DCE-MRI) to evaluate mesorectal microcirculation in patients with rectal cancer. MATERIALS AND METHODS. A total of 53 patients with semicircular rectal tumors underwent DCE-MRI with a 3-T MRI system before surgery. ROIs were manually delineated in the mesorectum that surrounded the tumor and the mesorectum that surrounded the normal rectal wall. DCE-MRI parameters including forward volume transfer constant (K trans ), reverse volume transfer constant (k ep ), and fractional extravascular extracellular space volume (V e ) were estimated using computer software. Histopathologic analysis served as the standard reference. RESULTS. Mesorectum that surrounded the tumor showed significantly higher K trans val ues than mesorectum that surrounded normal rectal wall (mean, 0.069 ± 0.035 [SD] vs 0.039 ± 0.020 min -1 ; p < 0.001). The tumor-surrounding mesorectum also showed higher V e values than normal mesorectum ( p < 0.001). An opposite trend was observed for k ep , but this was not significant ( p = 0.077). A lower K trans of the tumor-surrounding mesorectum was observed in patients with malignant lymph nodes compared with those with benign lymph nodes (mean, 0.054 ± 0.027 vs 0.076 ± 0.036 min -1 ; p = 0.034). Although k ep values for the tumor-surrounding mesorectum were higher in patients with tumors categorized as pathologic Tis (pTis) to pT2 than in those with pT3 tumors, the p value was close to 0.05 ( p = 0.047). The tumor-surrounding mesorectum showed no significant differences in the aforementioned parameters between patients with positive MRI-detected extramural vascular invasion (mrEMVI) and those with negative mrEMVI. CONCLUSION. Mesorectum that surrounded rectal tumor had a higher blood flow than that close to the normal rectal wall. The blood flow decreased in the tumor-surrounding mesorectum when there was nodal involvement.

Introduction: Stereoelectroencephalography (SEEG) refers to a commonly used diagnostic procedure to localise and define the epileptogenic zone of refractory focal epilepsies, by means of minimally invasive operation techniques without large craniotomies., Objective: This study aimed to investigate the influence of different registration methods on the accuracy of SEEG electrode implantation under neuronavigation for paediatric patients with refractory epilepsy., Methods: The clinical data of 18 paediatric patients with refractory epilepsy were retrospectively analysed. The SEEG electrodes were implanted under optical neuronavigation while the patients were in the prone position. Patients were divided into two groups on the basis of the surface-based registration of MR scan method and refined anatomy-based registration of CT scan. Registration time, accuracy, and the differences between electrode placement and preoperative planned position were analysed., Results: Thirty-six electrodes in 7 patients were placed under surface-based registration of MR scan, and 45 electrodes in 11 patients were placed under refined anatomy-based registration of CT scan. The registration time of surface-based registration of MR scan and refined anatomy-based registration of CT scan was 45 ± 12 min and 10 ± 4 min. In addition, the mean registration error, the error of insertion point, and target error were 3.6 ± 0.7 mm, 2.7 ± 0.7 mm, and 3.1 ± 0.5 mm in the surface-based registration of MR scan group, and 1.1 ± 0.3 mm, 1.5 ± 0.5 mm, and 2.2 ± 0.6 mm in the refined anatomy-based registration of CT scan group. The differences between the two registration methods were statistically significant., Conclusions: The refined anatomy-based registration of CT scan method can improve the registration efficiency and electrode placement accuracy, and thereby can be considered as the preferred registration method in the application of SEEG electrode implantation under neuronavigation for treatment of paediatric intractable epilepsy., (© 2020 S. Karger AG, Basel.)

Purpose: To compare the diagnostic accuracies of MDCT and high-resolution MRI (HR-MRI) for regional nodal metastases with different short-axis diameter ranges in rectal cancer patients., Methods: Rectal adenocarcinoma patients who underwent both MDCT and HR-MRI before surgery were included. The maximum short-axis diameters of the nodes were measured, and were classified as benign or malignant on imaging findings. All of the nodes were subdivided as follows: ≤ 5 mm (Group A), > 5 mm and ≤ 10 mm (Group B) , and > 10 mm (Group C). The postoperative pathological reports were used as the standard, and the sensitivity, specificity, accuracy, ROC curve, and AUC value were calculated for each subgroup., Results: A total of 592 nodes were included in the node-to-node evaluation. In Group A, the specificity and accuracy of HR-MRI were significantly higher than those of MDCT (99.28% vs. 93.99%, P < 0.001; 95.78% vs. 89.56%, P = 0.010; respectively). In Group B, the specificity and accuracy of HR-MRI were also higher than those of MDCT (98.36% vs. 55.74%, P < 0.001; 80.45% vs. 66.17%, P < 0.001; respectively). For Groups A and B, the AUCs of MDCT were both 0.65, whereas those of HR-MRI were 0.76 and 0.82, respectively. In Group C, all nine malignant nodes were correctly diagnosed metastases on MDCT, whereas one was misjudged as benign on HR-MRI., Conclusions: The diagnostic value of HR-MRI is superior to that of MDCT, with higher specificity, accuracy, and AUC values for HR-MRI than for MDCT.

Currently, the use of magnetic resonance imaging (MRI) in patients with esophageal carcinoma is limited. However, the quality of MRI for esophageal carcinoma continues to improve and the importance of MRI in patients with esophageal carcinoma has been gradually recognized. Compared with endoscopic ultrasound and computed tomography applied in T and N staging, MRI has now achieved excellent results after the imaging technique has been optimized. We review the literature on MRI and discuss the future of MRI in esophageal carcinoma. While the role of MRI in staging, tumor volume target delineation and evaluation for preoperative chemoradiotherapy, prognosis and recurrence is still evolving. The application of MRI in esophageal carcinoma has a bright future and potential to improve precision of T and N staging as well as treatment delivery., (© 2019 John Wiley & Sons Australia, Ltd.)

Commercial gadolinium-based materials have been widely used as contrast agents for magnetic resonance imaging (MRI), but the high toxicity of leaking free Gd 3+ ions still raises biosafety concerns. Here, we develop a novel, safe, and efficient MRI contrast agent based on a stable Fe(III) complex of fluorine and nitrogen co-doped carbon dots (F,N-CDs) that was prepared from glucose and levofloxacin by a simple microwave-assisted thermal decomposition method. The obtained Fe 3+ @F,N-CD complex exhibits higher longitudinal relaxivity ( r 1 = 5.79 mM -1 ·s -1 ) than that of the control samples of the Fe 3+ @CD complex ( r 1 = 4.23 mM -1 s -1 ) and free Fe 3+ ( r 1 = 1.59 mM -1 s -1 ) in aqueous solution, as assessed by a 1.5 T NMR analyzer. More importantly, the Fe 3+ @F,N-CD complex is very stable with a large coordination constant of 1.06 × 10 7 in aqueous medium. While incubated with HeLa cells, the Fe 3+ @F,N-CD complex shows clear MR images, demonstrating that it has potential to be an excellent MRI contrast agent. Furthermore, in vivo MRI experiments indicate that the Fe 3+ @F,N-CD complex provides high-resolution MRI pictures of 4T1 tumor bearing BALB/c mice 15 min after injection and can be completely excreted 2 h after administration. No cytotoxicity was observed with F,N-CDs and Fe concentration up to 0.2 mg/mL and 0.3 mM in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation assay, respectively. The possible mechanism of the enhanced MRI effect of the Fe 3+ @F,N-CD complex is therefore proposed. The extremely low toxicity, high r 1 relaxivity, strong photoluminescence, and low synthetic cost enable the Fe 3+ @F,N-CD complex to be a safe and promising T 1 -weighted MRI contrast agent for clinical applications.

Background: Intravoxel incoherent motion magnetic resonance imaging (IVIM-MRI) acquires tumor perfusion information without injection of contrast medium, which is promising in tumor assessment. However, its consistency with dynamic contrast-enhanced MRI (DCE-MRI), a more widely used method for tumor perfusion evaluation, is not revealed in rectal cancer., Purpose: In this study, we aimed to investigate the correlation of perfusion-sensitive parameters derived from IVIM-MRI with DCE-MRI and measurement reproducibility of IVIM-MRI parameters in rectal cancer., Material and Methods: Forty-seven rectal cancer patients underwent IVIM-MRI with 16 b-values and DCE-MRI. The perfusion fraction ( f), pseudo-diffusion coefficient ( D*), and f· D* were measured by two radiologists independently and correlated with the transfer constant ( K trans ), reflux constant ( k ep ), and extravascular extracellular fractional volume ( v e ) obtained from DCE-MRI., Results: Pearson's correlation analyses of IVIM-MRI and DCE-MRI parameters showed fair to moderate correlation between f and K trans ( r = 0.461, P = 0.001), followed by f and k ep ( r = 0.430, P = 0.003), f·D*, and K trans ( r = 0.425, P = 0.003), f·D*, and k ep ( r = 0.384, P = 0.008). There was no significant correlation between v e and f, v e and D*, v e and f· D*, D* and K trans , and D* and k ep . The reproducibility of IVIM-MRI measurements was moderate. For parameter f, intraclass correlation coefficient (ICC) = 0.71 (0.53-0.82), coefficient of variation (CV) = 13.05 ± 0.02%, limit of agreement (LoA) = -0.05-0.04; for parameter D*, ICC = 0.55 (0.32-0.72), CV = 20.28 ± 3.23%, LoA = -9.6-8.4., Conclusion: Perfusion-sensitive parameters derived from IVIM-MRI correlated fairly to moderately with DCE-MRI in rectal cancer patients and showed moderate measurement reproducibility. IVIM-MRI supplements routine high-resolution MRI without contrast enhancement to provide information of tumor microcirculation.

Aim: Accurate preoperative assessment of ovarian malignancy in endometrial carcinoma helps in determining the decision to preserve the ovaries in individualized treatment. This study adopted decision tree method to evaluate the diagnostic efficiency of pelvic MRI and clinical data of patients for preoperative identification of endometrial carcinoma-combined ovarian malignancy (EC-OM)., Material and Methods: This retrospective study included a total of 801 patients, and postoperative pathological examinations identified 58 EC-OM group and 743 endometrial carcinoma cases without ovarian malignancy (EC group). Diagnostic efficiency of pelvic MRI in EC-OM was calculated by comparing the clinical data and imaging features of patients in the two groups. Decision tree analysis was performed to screen out associative indexes and establish a diagnostic model for EC-OM., Results: Pelvic MRI showed that, EC-OM group showed deeper invasion into the myometrium, and higher percentages of patients with cervical or cornual involvement, or metastasis of lymph nodes or peritoneum than EC group (P = 0.00). Preoperative pelvic MRI showed a sensitivity of 51.72% and a specificity of 99.87% when detecting ovarian malignancy in endometrial carcinoma. Decision tree model obtained a sensitivity of 89.66%, with an AUC (area under ROC curve) of 0.949 (95% CI 0.906, 0.993, P < 0.001)., Conclusion: Decision tree analysis based on pelvic MRI and clinical data of patients showed that the detection rate of ovarian malignancy could be increased for patients with endometrial carcinoma., (Copyright © 2018. Published by Elsevier Inc.)

Many functional magnetic resonance imaging (fMRI) studies have indicated that Granger causality analysis (GCA) is a suitable method for revealing causal effects between brain regions. The purpose of the present study was to identify neuroimaging biomarkers with a high sensitivity to amnestic mild cognitive impairment (aMCI). The resting-state fMRI data of 30 patients with Alzheimer's disease (AD), 14 patients with aMCI, and 18 healthy controls (HC) were evaluated using GCA. This study focused on the "triple networks" concept, a recently proposed higher-order functioning-related brain network model that includes the default-mode network (DMN), salience network (SN), and executive control network (ECN). As expected, GCA techniques were able to reveal differences in connectivity in the three core networks among the three patient groups. The fMRI data were pre-processed using DPARSFA v2.3 and REST v1.8. Voxel-wise GCA was performed using the REST-GCA in the REST toolbox. The directed (excitatory and inhibitory) connectivity obtained from GCA could differentiate among the AD, aMCI and HC groups. This result suggests that analysing the directed connectivity of inter-hemisphere connections represents a sensitive method for revealing connectivity changes observed in patients with aMCI. Specifically, inhibitory within-DMN connectivity from the posterior cingulate cortex (PCC) to the hippocampal formation and from the thalamus to the PCC as well as excitatory within-SN connectivity from the dorsal anterior cingulate cortex (dACC) to the striatum, from the ECN to the DMN, and from the SN to the ECN demonstrated that changes in connectivity likely reflect compensatory effects in aMCI. These findings suggest that changes observed in the triple networks may be used as sensitive neuroimaging biomarkers for the early detection of aMCI.

This study aimed to determine whether dynamic contrast-enhanced MRI (DCE-MRI) derived parameters can identify oesophageal squamous cell carcinoma (SCC) and lymphatic metastasis. Thirty-nine oesophageal SCC patients underwent DCE-MRI. Quantitative parameters including endothelial transfer constant (K trans ), reflux rate (K ep ), fractional extravascular extracellular space volume and fractional plasma volume, and semi-quantitative parameters including time to peak (TTP), max concentration, Max Slope and area under concentration-time curve of both oesophageal SCC and normal oesophagus were measured. Mann-Whitney U test revealed that K trans and K ep of oesophageal SCC were higher while TTP was shorter when compared to normal oesophagus (all P-values < 0.05); and areas under receiver operating characteristic [ROC] curves displayed that K ep was superior to TTP or K trans for identifying oesophageal SCC (0.903 vs. 0.832 or 0.713). Mann-Whitney U test also demonstrated that K ep was higher and TTP was shorter in patients with lymphatic metastasis when compared to non-metastatic cancer patients (both P-values < 0.05), and area under ROC curve also showed that TTP was superior to K ep for predicting lymphatic metastasis (0.696 vs. 0.659). In conclusion, the combination of quantitative and semi-quantitative parameters derived from DCE-MRI can aid in the identification of oesophageal SCC and lymphatic metastasis.

Purpose: To determine whether gross tumour volume (GTV) of adenocarcinoma of oesophagogastric junction (AOG) measured on fat-suppression T 2 -weighted imaging (FS-T 2 WI) and diffusion-weighted imaging (DWI) correlates with regional lymph node metastasis and N stage., Materials and Methods: The study was approved by the institutional ethics committee, and written informed consent was obtained. Forty-six patients with AOG underwent preoperative magnetic resonance scans including FS-T 2 WI and DWI with b-values of 500 and 800 s/mm 2 . GTV was measured on FS-T 2 WI and DWI. Statistical analyses were performed to determine association of GTV with N stage., Results: Univariate analysis showed GTV measured on FS-T 2 WI and DWI with b-values of 500 and 800 s/mm 2 were correlated with lymph node metastasis (all Ps < 0.05). Spearman rank correlation tests demonstrated a trend toward an increase in GTV obtained on previous sequences with increasing N stage (r = 0.578 to 0.591, all Ps < 0.001). Mann-Whitney U tests showed GTV obtained on previous sequences could distinguish grouped N stages (all Ps < 0.05). Receiver operating curve analyses demonstrated that GTV obtained on FS-T 2 WI and DWI with b-value of 500 s/mm 2 and DWI with b-value of 800 s/mm 2 might differentiate stage N0 from stages N1-3 (cutoff, 19.70 cm 3 , 16.70 cm 3 and 12.24 cm 3 , respectively), stages N0-1 from N2-3 (cutoff: 22.16 cm 3 , 17.54 cm 3 and 14.17 cm 3 , respectively), stages N0-2 from N3 (cutoff: 25.57 cm 3 , 29.27 cm 3 and 22.73 cm 3 , respectively)., Conclusion: There is a trend toward an increase in GTV obtained on FS-T 2 WI and DWI sequences with increasing N stage., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: The aim of this study was to discriminate metastatic from nonmetastatic regional lymph nodes (LNs) with short-axis diameters of less than 5 mm in rectal cancer using quantitative parameters derived from dynamic contrast-enhanced (DCE) MRI., Subjects and Methods: Sixty-five LNs from 122 patients were evaluated, including malignant LNs (n = 27) and benign LNs (n = 38). The following parameters were assessed: the forward volume transfer constant (K trans ), reverse volume transfer constant (k ep ), fractional extravascular extracellular space volume (Ve), short-axis diameter, long-axis diameter, and short- to long-axis diameter ratio. ROC curves were used to analyze statistically significant parameters., Results: Metastatic LNs exhibited a lower K trans than did nonmetastatic LNs (p < 0.001), but the other parameters were not significantly different between the two groups. The AUC of the K trans was 0.732, with a 95% CI of 0.610-0.854, and the diagnostic cutoff value was 0.088 min -1 (sensitivity, 60.5%; specificity, 81.5%)., Conclusion: K trans had moderate diagnostic performance in assessing small regional LNs in rectal cancer and appears to be a useful predictor when distinguishing malignant LNs from benign LNs only by morphology is difficult.

Objectives: To determine association of gross tumour volume (GTV) of resectable oesophageal squamous cell carcinoma (SCC) measured on T 2 -weighted imaging (T 2 WI), contrast-enhanced T 1 -weighted imaging (CE-T 1 WI) and diffusion-weighted imaging (DWI) with T category and lymphatic metastasis (LM)., Methods: Sixty oesophageal SCC patients underwent fat-suppressed T 2 WI, CE-T 1 WI and DWI with b values of 0, 500 and 800 s/mm 2 . GTV was measured on three sequences. Statistical analyses were performed to determine association of GTV with T category and LM., Results: Spearman's rank correlation analysis showed positive association of GTV with T category and LM (all p values < 0.01). Differences in GTV were found between T1 and T2 or T3 categories shown by Kruskal-Wallis H and one-way ANOVA tests, and between T1/T2 and T3 and between tumours with and without LM by Mann-Whitney U tests (all p values < 0.05). Receiver operating characteristic analyses showed cut-off GTVs of 5.795, 5.276 and 10.11 cm 3 on CE-T 1 WI could better differentiate T1 from T2 categories, T1 from T3, and T1-2 from T3 than those of 7.066, 7.045 and 8.504 cm 3 on T 2 WI, of 5.793, 6.609 and 6.989 cm 3 on DWI with b value of 500 s/mm 2 , and of 4.156, 4.519 and 4.985 cm 3 with b value of 800 s/mm 2 , respectively. Cut-off of 10.462 cm 3 on DWI with b value of 500 s/mm 2 could better identify LM than of 12.38, 8.793 and 9.600 cm 3 on T 2 WI, CE-T 1 WI and DWI with b value of 800 s/mm 2 , respectively., Conclusions: GTVs on T 2 WI, CE-T 1 WI and DWI are associated with T category of and LM of oesophageal SCC., Key Points: • GTV is associated with T category and lymphatic metastasis of oesophageal SCC • GTV measured on contrast-enhanced T 1 -weighted imaging better identifies T category • GTV measured on DWI with b value of 500 s/mm 2 better identifies lymphatic metastasis.

Objective: The aim of the study was to analyze MR imaging features of renal epithelioid angiomyolipoma (EAML)., Methods: This study included 17 patients with histopathologically confirmed renal EAML who underwent renal MRI scanning before radical or partial nephrectomy. MR images were retrospectively reviewed and correlated with pathological findings., Result: Fifteen lesions (88.2%) appeared as round or oval. The tumor-kidney interface was round in 14 lesions (82.4%). Fifteen tumors (88.2%) presented mainly isointensity on T1WI, and eleven tumors (64.7%) presented mainly hypointensity on T2WI. Twelve lesions (70.6%) showed restricted diffusion on DWI, and the mean ADC value was 1.23 ± 0.28 × 10 -3 mm 2 /s. Minimal fat component was identified as loss of signal intensity on opposed-phase MR images in 6 cases (35.3%). Sixteen lesions (100%) demonstrated inhomogeneous enhancement, and 7 of 16 masses (43.8%) showed reticular enhancement. Rapid wash-in and wash-out enhancement was seen in 13 masses (81.3%). In the corticomedullary phase, the mass showed markedly enhancement in 14 cases (87.5%). The irregular vessels and hemorrhage were detected in 4 cases (23.5%) and 7 cases (41.2%), respectively. One patient (5.9%) had a lymph node involvement at initial diagnosis, and showed distant metastasis after operation. In the immunohistochemical analysis, 15 tumors (88.2%) were positive for melanocytic marker (HMB45 or Melan-A), and all cases (100%) were negative for epithelial-associated markers (CK or AE1/AE3)., Conclusion: The presence of hypointensity on T2WI, restricted diffusion on DWI, round tumor-kidney interface, reticular, and marked enhancement (rapid wash-in and wash-out) should further raise suspicion for renal EAML. The diagnosis may be confirmed by pathological analysis.

Hepatocellular carcinoma (HCC) is a common worldwide cancer that is rising rapidly in incidence. MRI is a powerful noninvasive imaging modality for HCC detection, but lack of specific contrast agents limits visualization of small tumors. EGFR is frequently overexpressed in HCC and is a promising target. Peptides have fast binding kinetics, short circulatory half-life, low imaging background, high vascular permeability, and enhanced tissue diffusion for deep tumor penetration. We demonstrate a peptide specific for EGFR labeled with an ultrasmall paramagnetic iron oxide (UPIO) nanoparticle with 3.5 nm dimensions to target HCC using T 1 -weighted MRI. We modified the hydrophobic core with oleic acid and capped with PEGylated phospholipids DSPE-PEG and DSPE-PEG-Mal. The EGFR peptide is attached via thioether-mediated conjugation of a GGGSC linker to the maleimide-terminated phospholipids. On in vivo MR images of HCC xenograft tumors, we observed peak nanoprobe uptake at 2 h post-injection followed by a rapid return to baseline by ∼24 h. We measured significantly greater MR signal in tumor with the targeted nanoprobe versus scrambled peptide, blocked peptide, and Gadoteridol. Segmented regions on MR images support rapid renal clearance. No significant difference in animal weight, necropsy, hematology, and chemistry was found between treatment and control groups at one month post-injection. Our nanoprobe based on an EGFR specific peptide labeled with UPIO designed for high stability and biocompatibility showed rapid tumor uptake and systemic clearance to demonstrate safety and promise for clinical translation to detect early HCC.

Objective: To explore the association between the blood oxygenation T 2 * values of resectable esophageal squamous cell carcinomas (ESCCs) and tumor stages., Materials and Methods: This study included 48 ESCC patients and 20 healthy participants who had undergone esophageal T 2 * -weighted imaging to obtain T 2 * values of the tumors and normal esophagi. ESCC patients underwent surgical resections less than one week after imaging. Statistical analyses were performed to identify the association between T 2 * values of ESCCs and tumor stages., Results: One-way ANOVA and Student-Newman-Keuls tests revealed that the T 2 * value could differentiate stage T1 ESCCs (17.7 ± 3.3 ms) from stage T2 and T3 tumors (24.6 ± 2.7 ms and 27.8 ± 5.6 ms, respectively; all p s < 0.001). Receiver operating curve (ROC) analysis showed the suitable cutoff T 2 * value of 21.3 ms for either differentiation. The former statistical tests demonstrated that the T 2 * value could not differentiate between stages T2 and T3 (24.6 ± 2.7 ms vs. 27.8 ± 5.6 ms, respectively, p > 0.05) or between N stages (N1 vs. N2 vs. N3: 24.7 ± 6.9 ms vs. 25.4 ± 4.5 ms vs. 26.8 ± 3.9 ms, respectively; all p s > 0.05). The former tests illustrated that the T 2 * value could differentiate anatomic stages I and II (18.8 ± 4.8 ms and 26.9 ± 5.9 ms, respectively) or stages I and III (27.3 ± 3.6 ms). ROC analysis depicted the same cutoff T 2 * value of 21.3 ms for either differentiation. In addition, the Student's t test revealed that the T 2 * value could determine grouped T stages (T0 vs. T1-3: 17.0 ± 2.9 ms vs. 25.2 ± 6.2 ms; T0-1 vs. T2-3: 17.3 ± 3.0 ms vs. 27.1 ± 5.3 ms; and T0-2 vs. T3: 18.8 ± 4.2 ms vs. 27.8 ± 5.6 ms, all p s < 0.001). ROC analysis indicated that the T 2 * value could detect ESCCs (cutoff, 20 ms), and discriminate between stages T0-1 and T2-3 (cutoff, 21.3 ms) and between T0-2 and T3 (cutoff, 20.4 ms)., Conclusion: The T 2 * value can be an additional quantitative indicator for detecting ESCC except for stage T1 cancer, and can preoperatively discriminate between some T stages and between anatomic stages of this tumor.

Purpose: To investigate whether liver lobe based T2* values measured on gradient recalled echo T2*-weighted imaging are associated with the presence and Child-Pugh class of hepatitis B-related cirrhosis., Methods: Fifty-six patients with hepatitis B-related cirrhosis and 23 healthy control individuals were enrolled in this study and underwent upper abdominal T2*-weighted magnetic resonance imaging. T2* values of the left lateral lobe (LLL), left medial lobe (LML), right lobe (RL) and caudate lobe (CL) were measured on T2*-weighted imaging. Statistical analyses were performed to determine the association between liver lobe based T2* values and the presence and Child-Pugh class of cirrhosis., Results: The T2* values of the LLL, LML and RL decreased with the progression of cirrhosis from Child-Pugh class A to C (r = -0.231, -0.223, and -0.395, respectively; all P < 0.05), except that of the CL (r = -0.181, P > 0.05). To a certain extent, Mann-Whitney U tests with Bonferroni correction for multigroup comparisons showed that the T2* values of the LLL, LML and RL could distinguish cirrhotic liver from healthy liver (all P < 0.05), whereas the T2* values of the CL could not (P > 0.05). Receiver operating characteristic analysis demonstrated that the T2* value of the RL could best distinguish cirrhosis from healthy liver, with an area under the receiver operating characteristic curve (AUC) of 0.713 among T2* values of the liver lobes, and that only the T2* value of the RL could distinguish Child-Pugh class C from A-B, with an AUC of 0.697 (all P < 0.05)., Conclusion: The T2* value of the RL can be associated with the presence and Child-Pugh class of hepatitis B-related cirrhosis.

Infantile spasm (IS) syndrome is an age-related epileptic encephalopathy that occurs in children. The purpose of this study was to investigate regional homogeneity (ReHo) changes in IS patients. Resting-state fMRI was performed on 11 patients with IS, along with 35 age- and sex-matched healthy subjects. Group comparisons between the two groups demonstrate that the pattern of regional synchronization synchronization in IS patients is changed. Decreased ReHo values were found in default mode network, bilateral motor-related areas and left occipital gyrus of the patient group. Increased ReHo was found in regions of cingulum, cerebellum, supplementary motor area and brain deep nucleus, such as hippocampus, caudate, thalamus and insula. The significant differences might indicate that epileptic action have some injurious effects on the motor, executive and cognitive related regions. In addition, ReHo values of left precuneus and right superior frontal gyrus were associated with the epilepsy duration in the IS group. The correlation results indicate that the involvement of these regions may be related to the seizure generation. Our results suggest that IS may have an injurious effect on the brain activation. The findings may shed new light on the understanding the neural mechanism of IS epilepsy.

Despite the progress in the design and synthesis of theranostic agents, limitations on efficiency and safety offer significant room for improvement in these agents. Inspired by the natural binding ability of polydopamine nanospheres (PDAs) with iron ion, a simple and versatile synthesis strategy is developed to prepare biodegradable coordination polymer (CP) encapsulated PDAs nanocomplex (PDAs@CPx, x = 3, 6, 9). We found that the PDAs@CP3 can serve as a T1/T2 dual mode contrast agent (DMCA) for magnetic resonance imaging (MRI), which possesses high longitudinal (r1 = 7.524 mM(-1) s(-1)) and transverse (r2 = 45.92 mM(-1) s(-1)) relaxivities. In this system, benefitting from the high photothermal conversion efficiency derived from PDAs, DOX loaded PDAs@CP3 nanocomplex is able to not only destroy the tumor directly by heat, but also stimulate the chemotherapy by enabling NIR-responsive on demand delivery of DOX. To the best of our knowledge, this is the first example exploring the potential of PDAs@CPx nanocomplex for T1/T2 dual mode MRI-guided chemo-photothermal synergistic therapy. This work extends the currently available theranostic agents, and opens up new avenues to rationally design the high-performance T1/T2 DMCA., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objectives: To investigate functional cerebral abnormalities in patients with amyotrophic lateral sclerosis (ALS) using functional magnetic resonance imaging (fMRI) during action observation., Methods: Thirty patients with ALS and 30 matched healthy controls underwent fMRI with an experimental paradigm while observing a video of repetitive flexion-extension of the fingers at three frequency levels or three complexity levels, alternated with periods of a static hand. A parametric analysis was applied to determine the effects of each of the two factors., Results: Action observation activated similar neural networks as the research on execution of action in the ALS patients and healthy subjects in several brain regions related to the mirror-neuron system (MNS). In the ALS patients, in particular, the dorsal lateral premotor cortex (dPMC), inferior parietal gyrus (IPG), and SMA, were more activated compared with the activation in the controls. Increased activation within the primary motor cortex (M1), dPMC, inferior frontal gyrus (IFG), and superior parietal gyrus (SPG) mainly correlated with hand movement frequency/complexity in the videos in the patients compared with controls., Conclusions: The findings indicated an ongoing compensatory process occurring within the higher order motor-processing system of ALS patients, likely to overcome the loss of function., Key Points: • Action observation activated similar core nodes of MNS in ALS and controls. • Increased activation within M1, dPMC, IFG and SPG mainly correlated with hand movement frequency/complexity. • Differences in patients and controls may be due to compensatory processes in ALS.

Purpose: To compare contrast-enhanced isotropic 3D-GRE-T1WI sequence vs. conventional non-isotropic sequence in terms of image quality, estimated signal-to-noise ratio (eSNR), relative tumor contrast and performance of cervical cancer staging., Methods: This retrospective study was approved by the institutional review board, and informed consent was waived. Seventy-one patients (47 ± 9.4 years), with pathologically-confirmed cervical cancer underwent axial contrast-enhanced 1 mm3 isotropic 3D-GRE-T1WI sequence (herein referred to Isotropy), and 3-mm-thick non-isotropic sagittal and coronal sequences. Image quality score, eSNR and relative contrast between tumor to myometrium, gluteal muscle, and fat respectively, were compared between 3-mm-thick reconstructed images from Isotropy and directly scanned non-isotropic images by paired t-test. Difference in tumor staging obtained from Isotropy and combined Three-planes including reconstructed axial images, directly scanned sagittal and coronal sequence were compared by McNemar test., Results: Both sequences showed similar image quality. Reconstructed images demonstrated higher eSNR, equal or lower relative tumor contrast compared with non-isotropic images. Compared with performing diagnosis on Three-planes, both reviewers showed higher accuracy when diagnosing vaginal invasion on Isotropy (p = 0.039 and 0.003, respectively)., Conclusion: Compared with non-isotropic sequence, 3.0T MR isotropic 3D-GRE-T1WI sequence exhibited better eSNR, providing more reliable clinical information for preoperative staging of cervical cancer.

We retrospectively investigated the imaging findings of bone scintigraphy, chest CT and chest MRI in 55 cases of lung cancer. The sensitivity, specificity and accuracy of the detection of rib metastases were compared between imaging modalities on both a per-lesion and a per-patient basis. On a per-lesion basis, MRI sensitivity and accuracy were significantly higher than that of bone scintigraphy and CT (P<0.05). The sensitivities, specificities, and accuracy levels between CT and bone scintigraphy did not differ on either a per-lesion or per-patient basis (P>0.05). MRI appears to be superior for the detection of ribs metastases in lung cancer.

Purpose: We aimed to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of peripheral primitive neuroectodermal tumor (pPNET) of the head and neck., Methods: Eight patients with pPNET of the head and neck confirmed by histopathological examination were analyzed retrospectively., Results: The average patient age was 8 years. The tumor location in the 8 patients was as follows: maxillofacial region (right, 2; left, 1), left maxillary sinus (1), right masticator space (1), left carotid space (1), right infratemporal fossa (1), and left parotid gland (1). All 5 patients who underwent CT demonstrated ill-defined soft masses and no calcification. Three patients with tumors in the maxillofacial region showed homogeneous small masses and a mild enhancement. The patient with left maxillary sinus tumor showed a heterogeneous mass with patchy, necrotic foci and mild heterogeneous enhancement. The patient with right masticator space tumor showed a heterogeneous mass, and marked heterogeneous enhancement. The T1-weighted images of the patients with right infratemporal fossa, left carotid space, and left parotid gland tumors were isointense. The T2-weighted images were heterogeneous and mildly hyperintense in 2 patients and hyperintense in 1 patient. Heterogeneous intermediate enhancement was demonstrated in 2 patients and mild ring enhancement in 1 patient., Conclusion: The imaging features of pPNET of the head and neck are non-specific. An ill-defined, aggressive mass and variable enhancement on CT and MR images may suggest the diagnosis of pPNET. Peripheral PNET should be included in the differential diagnosis of children and adolescents' regional tumors., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Abstract Background Diabetic peripheral neuropathy (DPN) has been shown to be independently associated with cardiovascular events and mortality. This study aimed to evaluate changes in left ventricular (LV) microvascular perfusion and myocardial deformation in type 2 diabetes mellitus (T2DM) patients with and without DPN, as well as to investigate the association between myocardial perfusion and LV deformation. Methods Between October 2015 and July 2022, one hundred and twenty-three T2DM patients without DPN, fifty-four patients with DPN and sixty age‑ and sex‑matched controls who underwent cardiovascular magnetic resonance imaging were retrospectively analyzed. LV myocardial perfusion parameters at rest, including upslope, time to maximum signal intensity (TTM), max signal intensity (max SI), and myocardial strains, including global radial, circumferential and longitudinal strain (GRS, GCS and GLS, respectively), were calculated and compared among the groups with One‑way analysis of variance. Univariable and multivariable linear regression analyses were performed to explore the independent factors influencing LV myocardial perfusion indices and LV strains in diabetes. Results The LV GLS, upslope and max SI were significantly deteriorated from controls, through patients without DPN, to patients with DPN (all P

Abstract Background Type 2 diabetes mellitus (T2DM) frequently coexists with obstructive coronary artery disease (OCAD), which are at increased risk for cardiovascular morbidity and mortality. This study aimed to investigate the impact of coronary obstruction on myocardial microcirculation function in T2DM patients, and explore independent predictors of reduced coronary microvascular perfusion. Methods Cardiac magnetic resonance (CMR) scanning was performed on 297 T2DM patients {188 patients without OCAD [T2DM(OCAD −)] and 109 with [T2DM(OCAD +)]} and 89 control subjects. CMR-derived perfusion parameters, including upslope, max signal intensity (MaxSI), and time to maximum signal intensity (TTM) in global and segmental (basal, mid-ventricular, and apical slices) were measured and compared among observed groups. According to the median of Gensini score (64), T2DM(OCAD +) patients were subdivided into two groups. Univariable and multivariable linear regression analyses were performed to identify independent predictors of microcirculation dysfunction. Results T2DM(OCAD −) patients, when compared to control subjects, had reduced upslope and prolonged TTM in global and all of three slices (all P 64 group, the upslope declined and TTM prolonged progressively in global and mid-ventricular slice (all P

Aim: The retina and brain share similar anatomical and physiological features. Thus, retinal imaging by optical coherence tomography angiography (OCTA) might be a potential tool for the early diagnosis of diabetic cerebral small vessel disease (CSVD). In this study, we aimed to evaluate retinal vascular density (VD) in diabetic CSVD by OCTA imaging and explore the associations between retinal VD and cerebral magnetic resonance imaging (MRI) markers and cognitive function. Methods: In total, 131 patients were enrolled, including CSVD (n = 43) and non‐CSVD groups (n = 88). The VD and foveal avascular zone of the retinal capillary plexus were measured with OCTA. A brain MRI was performed. Results: MRI imaging showed that in the diabetic CSVD group, white matter hyperintensities (WMHs), particularly deep WMHs (58.82%), are the most common MRI marker, followed by cerebral microbleeds in the subtentorial and cortical areas (34.78%). The CSVD group showed increases in the prevalence of cognitive dysfunction (p =.034) and depression (p =.033) and decreases in visuospatial/executive ability and delayed recall ability. In the CSVD group, VDs of the macular superficial vascular plexus (32.93 ± 7.15% vs. 36.97 ± 6.59%, p =.002), intermediate capillary plexus (20.87 ± 4.30% vs. 23.08 ± 4.30%, p =.005) and deep capillary plexus (23.54 ± 5.00% vs. 26.05 ± 4.20%, p =.003) were lower than those of the non‐CSVD group. Multiple linear regression analysis showed that VD of the macular superficial vascular plexus was independently associated with cerebral microbleeds. Meanwhile, VD of the macular intermediate capillary plexus was associated with white matter lacunar infarcts after adjustment. Conclusions: Diabetic CSVDs are characterized by MRI markers, including deep WMHs and cerebral microbleeds, and showed impaired cognition with decreased visuospatial/executive ability and delayed recall ability. OCTA imaging revealed a significant decrease in retinal microvascular perfusion in diabetic CSVD, which was related to MRI markers and cognitive function. OCTA might be a valuable potential measurement for the early diagnosis of CSVD. [ABSTRACT FROM AUTHOR]

Background: Post-radiation nasopharyngeal necrosis (PRNN) is a severe adverse event following re-radiotherapy for patients with locally recurrent nasopharyngeal carcinoma (LRNPC) and associated with decreased survival. Biological heterogeneity in recurrent tumors contributes to the different risks of PRNN. Radiomics can be used to mine high-throughput non-invasive image features to predict clinical outcomes and capture underlying biological functions. We aimed to develop a radiogenomic signature for the pre-treatment prediction of PRNN to guide re-radiotherapy in patients with LRNPC. Methods: This multicenter study included 761 re-irradiated patients with LRNPC at four centers in NPC endemic area and divided them into training, internal validation, and external validation cohorts. We built a machine learning (random forest) radiomic signature based on the pre-treatment multiparametric magnetic resonance images for predicting PRNN following re-radiotherapy. We comprehensively assessed the performance of the radiomic signature. Transcriptomic sequencing and gene set enrichment analyses were conducted to identify the associated biological processes. Results: The radiomic signature showed discrimination of 1-year PRNN in the training, internal validation, and external validation cohorts (area under the curve (AUC) 0.713–0.756). Stratified by a cutoff score of 0.735, patients with high-risk signature had higher incidences of PRNN than patients with low-risk signature (1-year PRNN rates 42.2–62.5% vs. 16.3–18.8%, P < 0.001). The signature significantly outperformed the clinical model (P < 0.05) and was generalizable across different centers, imaging parameters, and patient subgroups. The radiomic signature had prognostic value concerning its correlation with PRNN-related deaths (hazard ratio (HR) 3.07–6.75, P < 0.001) and all causes of deaths (HR 1.53–2.30, P < 0.01). Radiogenomics analyses revealed associations between the radiomic signature and signaling pathways involved in tissue fibrosis and vascularity. Conclusions: We present a radiomic signature for the individualized risk assessment of PRNN following re-radiotherapy, which may serve as a noninvasive radio-biomarker of radiation injury-associated processes and a useful clinical tool to personalize treatment recommendations for patients with LANPC. [ABSTRACT FROM AUTHOR]

Background: Mitral regurgitation may occur when hypertension causes left ventricular (LV) and left atrial (LA) remodeling. However, its role in LA function in hypertensive patients remains unclear. Purpose: To explore how mitral regurgitation affects LA function in hypertension and to investigate atrioventricular interaction in hypertensive patients with mitral regurgitation. Study Type: Retrospective. Population: A total of 193 hypertensive cases and 64 controls. Field Strength/Sequence: A 3.0 T/balanced steady‐state free precession. Assessment: LA volume (LAV), LA strain (reservoir, conduit, and active), LA ejection fraction, and LV strain (global peak longitudinal [GLS], circumferential [GCS], and radial strain [GRS]) were evaluated and compared among groups. Regurgitant fraction (RF) was evaluated in regurgitation patients and used to subdivide patients into mild (RF: 0%–30%), moderate (RF: 30%–50%), and severe (RF: >50%) regurgitation categories. Statistical Tests: One‐way analysis of variance, Spearman and Pearson's correlation coefficients (r), and multivariable linear regression analysis. A P value <0.05 was considered statistically significant. Results: Hypertensive patients without mitral regurgitation showed significantly impaired LA reservoir and conduit functions and significantly decreased LV GLS but preserved pump function and LAV compared to controls (P = 0.193–1.0). Hypertensive cases with mild regurgitation (N = 22) had significantly enlarged LAV and further reduced LA reservoir function, while the group with moderate regurgitation (N = 20) showed significantly reduced LA pump function, further impaired conduit function, and significantly reduced LV strain. The severe regurgitation (N = 13) group demonstrated significantly more severely impaired LA and LV functions and LAV enlargement. Multivariable linear regression showed that regurgitation degree, GRS, GCS, and GLS were independently correlated with the LA reservoir, conduit, and active strain in hypertensive patients with mitral regurgitation. Data Conclusion: Mitral regurgitation may exacerbate LA and LV impairment in hypertension. Regurgitation degree, LV GRS, GCS, and GLS were independent determinants of the LA strain in hypertensive patients with mitral regurgitation, which demonstrated atrioventricular interaction. Evidence Level: 4. Technical Efficacy: Stage 3. [ABSTRACT FROM AUTHOR]