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Background: An association has been identified between mitral valve prolapse (MVP) and sudden cardiac arrest (SCA), and ventricular arrhythmias (VA). This study aimed to elucidate predictive factors for SCA or VA in MVP patients., Methods: MVP patients who underwent cardiac magnetic resonance (CMR) were retrospectively included. Patients with other structural heart disease or causes of aborted SCA were excluded. Clinical characteristics (sex, age, body mass index, histories of diabetes, hypertension, and dyslipidemia) and electrocardiographic (PR interval, QRS duration, corrected QT interval, inverted T wave in the inferior leads, bundle branch block, and atrial fibrillation), echocardiographic [mitral regurgitation grade, prolapsing mitral leaflet, and right ventricular systolic pressure (RVSP)], and CMR [left atrial volume index, both ventricular ejection fractions, both ventricular end-diastolic and systolic volume indexes, prolapse distance, mitral annular disjunction, systolic curling motion, presence of late gadolinium enhancement (LGE), LGE volume and proportion] parameters were analyzed., Results: Of the 85 patients [age, 54.0 (41.0-65.0) years; 46 men], seven experienced SCA or VA. Younger age and wide QRS complex were observed more often in the SCA/VA group than in the no-SCA/VA group. The SCA/VA group exhibited lower RVSP, more systolic curling motion and LGE, greater LGE volume, and higher LGE proportion. The presence of LGE [hazard ratio (HR), 19.8; 95% confidence interval (CI) 2.65-148.15; P = 0.004], LGE volume (HR 1.08; 95% CI 1.02-1.14; P = 0.006) and LGE proportion (HR 1.32; 95% CI 1.08-1.60; P = 0.006) were independently associated with higher risk of SCA or VA in MVP patients together with systolic curling motion in each model., Conclusions: The presence of systolic curling motion, high LGE volume and proportion, and the presence of LGE on CMR were independent predictive factors for SCA or VA in MVP patients., (© 2021. The Author(s).)

OBJECTIVE. The purposes of this study were to evaluate the accuracy of a semiautomatic method of measuring liver surface nodularity (LSN) on contrast-enhanced MR images and to compare the LSN score with pathologic fibrosis stage. MATERIALS AND METHODS. This retrospective study included patients who had undergone gadoxetate disodium-enhanced liver MRI 6 months before or after histopathologic investigation including percutaneous parenchymal biopsy and surgical biopsy for staging of chronic liver disease between January 2010 and December 2018. Semiautomated LSN quantification software was developed to measure LSN at MRI. Aspartate aminotransferase to platelet ratio index and fibrosis-4 index were derived from serum laboratory test results. The reference standard for staging of liver fibrosis was Metavir score. The accuracy of LSN score for staging of liver fibrosis was evaluated with AUC, and the optimal cutoff value was calculated by Youden index. Spearman correlation coefficient was used for correlation analysis. RESULTS. The study included 132 patients (93 men, 39 women). LSN score was evaluated without technical failure. There was high correlation between LSN score and Metavir score (Spearman ρ = 0.713, p < 0.001). The AUCs of LSN score for distinguishing Metavir score were 0.93 for F0-F1 versus F2-F4 (95% CI, 0.88-0.97; p < 0.001), 0.98 for F0-F2 vs F3-F4 (95% CI, 0.95-1.00; p < 0.001), and 0.83 for F0-F3 versus F4 (95% CI, 0.76-0.90; p < 0.001). The optimal cutoff value for differentiating F0-F2 from F3-F4 was 0.850 with 100% sensitivity and 85.4% specificity. CONCLUSION. LSN score calculated semiautomatically from MR images of the liver has high accuracy and correlates directly with the pathologic fibrosis stage.

Liver biopsy is the reference standard test to differentiate between non-alcoholic steatohepatitis (NASH) and simple steatosis (SS) in non-alcoholic fatty liver disease (NAFLD), but noninvasive diagnostics are warranted. The diagnostic accuracy in NASH using MR imaging modality have not yet been clearly identified. This study was assessed the accuracy of magnetic resonance imaging (MRI) method for diagnosing NASH. Data were extracted from research articles obtained after a literature search from multiple electronic databases. Random-effects meta-analyses were performed to obtain overall effect size of the area under the receiver operating characteristic(ROC) curve, sensitivity, specificity, likelihood ratios(LR), diagnostic odds ratio(DOR) of MRI method in detecting histopathologically-proven SS(or non-NASH) and NASH. Seven studies were analyzed 485 patients, which included 207 SS and 278 NASH. The pooled sensitivity was 87.4% (95% CI, 76.4-95.3) and specificity was 74.3% (95% CI, 62.4-84.6). Pooled positive LR was 2.59 (95% CI, 1.96-3.42) and negative LR was 0.17 (95% CI, 0.07-0.38). DOR was 21.57 (95% CI, 7.27-63.99). The area under the curve of summary ROC was 0.89. Our meta-analysis shows that the MRI-based diagnostic methods are valuable additions in detecting NASH.

Rationale and Objectives: The roles of iron stores in nonalcoholic fatty liver disease have not yet been clearly identified, and it is lack of uniform criteria and a standardized study design for assessing the liver iron content (LIC) in nonalcoholic steatohepatitis (NASH). This study was to compare LICs in biopsy-proven simple steatosis (SS) and NASH based on T 2 ⁎ -relaxometry., Material and Methods: A total of 32 subjects divided to three groups, consisting of 10 healthy controls, 12 SS and 10 NASH. All MRI examinations were performed on a 3 T MRI with a 32-channel body coil. To measure T 2 ⁎ -value, we used a gradient echo sequence with six multiechoes within a single breath-hold. Hepatic iron contents among three groups were compared using Kruskal-Wallis H test and Mann-Whitney's posthoc tests. Diagnostic accuracy was determined by calculating the area under the receiver operating characteristics curve. To identify the reliability of iron measurements in the different region of interests, coefficient of variance (CV) was calculated overall CV values for the variability of measurements. Interobserver agreement and reliability were estimated by calculating the intraclass correlation coefficient., Results: The variations of all LIC measurements are not exceeded 20%, as a mean CV value 18.3%. intraclass correlation coefficients were higher than 0.9. Mean T 2 ⁎ -values at localized region of interests were healthy controls 45.42 ± 7.19 ms, SS 20.96 ± 4.28 ms, and NASH 15.49 ± 2.87 ms. The mean T 2 ⁎ -value in NASH is significantly shorter than that in SS (p = 0.008). The area under the receiver operating characteristics curve to distinguish NASH from SS was 0.908 (95% confidence interval 0.775-1.000, p = 0.001) at a cut-off of iron contents greater than 17.95 ms, and its diagnostic accuracy had 0.833 sensitivity and 0.800 specificity., Conclusion: This study demonstrates that the T 2 ⁎ calculation can help to differentially diagnose NASH., (Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Background: Studies regarding magnetic resonance imaging (MRI) findings of the lateral ankle ligaments in chronic lateral ankle instability and their clinical relevance for surgery are lacking. This study classified the lateral ankle ligament MRI findings of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) in chronic lateral ankle instability (CLAI) and correlated these findings with ankle stress radiographs., Methods: We included 132 ankles with CLAI that underwent ligament reconstructions from 2006 to 2013. The distributions of the ATFL and CFL morphologies were evaluated using the following categories: (1) the amount of thickness: normal/thickened/attenuated/non-visualized, (2) the presence of discontinuity, (3) wavy or irregular contour, and (4) increased signal intensity on T2-weighted images. The relationships between the ligament morphologies and stress radiographs were analyzed., Results: The ATFL was normal in 5 (4%) ankles, thickened in 35 (27%), attenuated in 76 (58%), and non-visualized in 16 (12%), while the CFL was normal in 39 (30%) ankles, thickened in 42 (32%), attenuated in 44 (33%), and non-visualized in 7 (5%). Discontinuity of the ATFL or CFL was observed in 46 (35%) ankles. Wavy or irregular contours were observed in 55 (42%) ATFLs and 37 (28%) CFLs, and signal intensity of both ligaments was increased in 19 (14%) ankles. ATFL ( P < .001) and CFL thickness ( P = .007) correlated with the talar tilt angle., Conclusions: The MRI findings of CLAI showed several morphologies and specific incidences for each morphology. Attenuated, wavy appearance was the most frequent MRI pattern. Thickness was related to the degree of instability., Level of Evidence: Level IV, retrospective case series.

Objective: To quantitatively measure hepatic fibrosis on gadoxetic acid-enhanced magnetic resonance (MR) in chronic hepatitis B (CHB) patients and identify the correlations with aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 index (FIB-4) values., Materials and Methods: This study on gadoxetic acid-enhanced 3T MR imaging included 81 patients with CHB infection. To quantitatively measure hepatic fibrosis, MR images were analyzed with an aim to identify inhomogeneous signal intensities calculated from a coefficient of variation (CV) map in the liver parenchyma. We also carried out a comparative analysis between APRI and FIB-4 based on metaregression results. The diagnostic performance of the CV map was evaluated using a receiver-operating characteristic (ROC) curve., Results: In the MR images, the mean CV values in control, groups I, II, and III based on APRI were 4.08 ± 0.92, 4.24 ± 0.80, 5.64 ± 1.11, and 5.73 ± 1.28, respectively ( p < 0.001). In CHB patients grouped by FIB-4, the mean CV values of groups A, B, and C were 4.22 ± 0.95, 5.40 ± 1.19, and 5.71 ± 1.17, respectively ( p < 0.001). The mean CV values correlated well with APRI ( r = 0.392, p < 0.001) and FIB-4 ( r = 0.294, p < 0.001). In significant fibrosis group, ROC curve analysis yielded an area under the curve of 0.875 using APRI and 0.831 using FIB-4 in HB, respectively., Conclusion: Gadoxetic acid-enhanced MR imaging for calculating a CV map showed moderate correlation with APRI and FIB-4 values and could be employed to quantitatively measure hepatic fibrosis in patients with CHB.

Sclerosing pneumocytoma (SP) of the lung is a rare benign neoplasm. Here, we describe an unusual presentation of SP with a wax-and-wane pattern of growth in a 47-year-old woman. Tumor diameter decreased over a 3-year follow-up period and then increased on serial follow-up computed tomography scans. The mass showed high signal intensity on both T1- and T2-weighted chest magnetic resonance imaging (MRI) and early enhancement with a plateau on dynamic MRI. We speculate that intratumoral bleeding and resorption processes accounted for the changes in tumor size.

To establish extracellular volume fraction (ECV) thresholds corresponding to myocardial lesion detected by late-gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging. Fifty-six patients with myocardial infarction or hypertrophic cardiomyopathy underwent LGE, pre- and post-contrast modified Look-Locker inversion recovery (MOLLI) sequences on a 3-T CMR system. Short-axis MOLLI images generated ECV maps of left ventricular (LV) walls. The LGE areas were semi-automatically determined by different signal threshold techniques. The areas of elevated ECV were measured using ECV thresholds of 28-48%. The LGE areas were compared with the areas of elevated ECV at the corresponding LV levels. The myocardial areas of LGE and elevated ECVs showed a strong and positive correlation (P < 0.01). The LGE threshold, set at two standard deviations above the mean signal from the remote myocardium, corresponded well with the area of ECV >32%. When using the full width at half-maximum (FWHM) technique, the LGE area corresponded well with the area of ECV >42 or 44%. By applying particular ECV thresholds, myocardial ECV maps can define myocardial status equivalent to LGE, and definite ECV thresholds may be useful for the straightforward evaluation of myocardial phenotypes.

Purpose: To evaluate the potential of prospective electrocardiography (ECG)- gated 64-slice multidetector computed tomography (MDCT) for evaluation of myocardial enhancement, infarct size, and stent patency after percutaneous coronary intervention (PCI) with stenting in patients with myocardial infarction., Materials and Methods: Seventeen patients who were admitted with acute myocardial infarction were examined with prospective ECG-gated 64-slice cardiac MDCT and magnetic resonance (MR) imaging after reperfusion using PCI with stenting. Cardiac MDCT was performed with two different phases: arterial and delayed phases. We evaluated the stent patency on the arterial phase, and nonviable myocardium on the delayed phase of computed tomography (CT) image, and they were compared with the results from the delayed MR images., Results: Total mean radiation dose was 7.7 +/- 0.5 mSv on the two phases of CT images. All patients except one showed good patency of the stent at the culprit lesion on the arterial phase CT images. All patients had hyperenhanced area on the delayed phase CT images, which correlated well with those on the delayed phase MR images, with a mean difference of 1.6% (20 +/- 10% vs. 22 +/- 10%, r = 0.935, p = 0.10). Delayed MR images had a better contrast-to-noise ratio (CNR) than delayed CT images (27.1 +/- 17.8% vs. 4.3 +/- 2.1%, p < 0.001)., Conclusion: Prospective ECG-gated 64-slice MDCT provides the potential to evaluate myocardial viability on delayed phase as well as for stent patency on arterial phase with an acceptable radiation dose after PCI with stenting in patients with myocardial infarction.

Objective: By using a functional magnetic resonance imaging (fMRI) technique we assessed brain activation patterns while subjects were viewing the living environments representing natural and urban scenery., Materials and Methods: A total of 28 healthy right-handed subjects underwent an fMRI on a 3.0 Tesla MRI scanner. The stimulation paradigm consisted of three times the rest condition and two times the activation condition, each of which lasted for 30 and 120 seconds, respectively. During the activation period, each subject viewed natural and urban scenery, respectively., Results: The predominant brain activation areas observed following exposure to natural scenic views in contrast with urban views included the superior and middle frontal gyri, superior parietal gyrus, precuneus, basal ganglia, superior occipital gyrus, anterior cingulate gyrus, superior temporal gyrus, and insula. On the other hand, the predominant brain activation areas following exposure to urban scenic views in contrast with natural scenes included the middle and inferior occipital gyri, parahippocampal gyrus, hippocampus, amygdala, anterior temporal pole, and inferior frontal gyrus., Conclusion: Our findings support the idea that the differential functional neuroanatomies for each scenic view are presumably related with subjects' emotional responses to the natural and urban environment, and thus the differential functional neuroanatomy can be utilized as a neural index for the evaluation of friendliness in ecological housing.

Human brain activation was assessed in terms of eco-friendliness while viewing still photographs depicting rural and urban surrounding environments with the use of a functional magnetic resonance imaging technique. A total of 30 subjects who had both rural and urban life experiences participated in this study. In order to explore the common and differential activation maps yielded by viewing two extreme types of scenery, random effect group analysis was performed with the use of one-sample and two-sample t-tests. Activation of the anterior cingulate gyrus, globus pallidus, putamen and head of the caudate nucleus was dominant during rural scenery viewing, whereas activation of the hippocampus, parahippocamus and amygdala was dominant during urban scenery viewing (p<0.01). These findings allow better characterization of neural activation, suggesting an inherent preference towards nature-friendly living. Such a theoretical acquisition may have an important practical impact in view of potential applications for bio-housing and the development of environmental psychology-related areas., (Copyright 2010 Elsevier B.V. All rights reserved.)

Objective: To assess the dynamic activations of the key brain areas associated with the time-course of the sexual arousal evoked by visual sexual stimuli in healthy male subjects., Materials and Methods: Fourteen right-handed heterosexual male volunteers participated in this study. Alternatively combined rest period and erotic video visual stimulation were used according to the standard block design. In order to illustrate and quantify the spatiotemporal activation patterns of the key brain regions, the activation period was divided into three different stages as the EARLY, MID and LATE stages., Results: For the group result (p < 0.05), when comparing the MID stage with the EARLY stage, a significant increase of the brain activation was observed in the areas that included the inferior frontal gyrus, the supplementary motor area, the hippocampus, the head of the caudate nucleus, the midbrain, the superior occipital gyrus and the fusiform gyrus. At the same time, when comparing the EARLY stage with the MID stage, the putamen, the globus pallidus, the pons, the thalamus, the hypothalamus, the lingual gyrus and the cuneus yielded significantly increased activations. When comparing the LATE stage with the MID stage, all the above mentioned brain regions showed elevated activations except the hippocampus., Conclusion: Our results illustrate the spatiotemporal activation patterns of the key brain regions across the three stages of visual sexual arousal.

Purpose: To evaluate the relationship between delayed enhancement (DE) and regional left ventricular function in hypertrophic cardiomyopathy (HCM) using gadolinium enhancement MRI and myocardial tagging MRI., Materials and Methods: Cine imaging, delayed enhancement imaging, and tagging MRI were performed in 25 patients with HCM. The location, pattern, and extent of DE were evaluated. Circumferential shortening (Ecc) was obtained by analyzing MR tagging images with HARP software., Results: DE occurred in 21 (84%) patients with a high frequency of localization in the septum and the right ventricular attachment sites. Circumferential shortening was significantly decreased in the enhanced segments compared with nonenhanced segments (P < 0.0001). The myocardial wall was thicker in the enhanced segments than in the nonenhanced segments (P < 0.0001). However, circumferential shortening was significantly decreased in the enhanced segments of the same thickness (P < 0.0001). Circumferential shortening was more substantially impaired in the segments with focal nodular enhancement than those in the segments with ill-defined patchy enhancement (P = 0.0002)., Conclusion: In HCM, DE is commonly found and circumferential shortening is significantly impaired in the regions with DE, regardless of the degree of myocardial hypertrophy. Focal nodular enhancement is particularly related with regional dysfunction in patients with HCM., ((c) 2008 Wiley-Liss, Inc.)

Rationale and Objectives: To investigate the capacity of manganese dipyridoxyl diphosphate (MnDPDP)-enhanced magnetic resonance imaging (MRI) to discriminate the injured myocardium from the normal myocardium in a cat model., Materials and Methods: Fourteen cats were prepared for acute myocardial infarction with 90-minute occlusion followed by 120-minute reperfusion. Inversion recovery gradient-recalled echo (IR-GRE) MR images were obtained at 60-minute intervals for 4 hours after the injection of MnDPDP, and ex vivo after the cats were killed. We evaluated the differences between the unenhanced area on the in vivo and ex vivo MR images and the unstained area on triphenyl tetrazolium chloride (TTC) staining., Results: The unenhanced area on the in vivo MR images was well correlated with that on the ex vivo MR images. The unenhanced area on the ex vivo MR images was significantly larger than the unstained area on TTC staining., Conclusions: This study suggests that the MnDPDP-unenhanced area on the MR images includes not only the infarcted myocardium but also the stunned myocardium.

Rationale and Objectives: To compare manganese dipyridoxyl diphosphate (MnDPDP)-enhanced magnetic resonance imaging (MRI) with cine MRI for distinguishing the dysfunctional myocardium from the normal myocardium., Materials and Methods: Seventeen cats were prepared for acute myocardial infarction with 90 minutes of occlusion followed by 120 minutes of reperfusion. In vivo inversion-recovery gradient-recalled echo MRI and cine MRI were performed. Two radiologists independently analyzed the MR images and recorded the size of the unenhanced area on the MnDPDP-enhanced MR images as well as that of the dysfunctional area on the cine MR images. Agreement between these abnormal areas was evaluated using Bland-Altman analysis. Interobserver agreement was assessed using Bland-Altman analysis., Results: The sizes of the unenhanced area on the MnDPDP-enhanced MR images and the dysfunctional area on the cine MR images showed good agreement on Bland-Altman analysis (the limits of agreement: observer 1= 1.8% +/- 11.6, observer 2 = 0.1% +/- 9.9). The abnormal segments on both types of MR imaging showed a good interobserver agreement (the limits of agreement: MnDPDP-enhanced MRI = 0.3% +/- 7.6, cine MRI = -1.4% +/- 10.9)., Conclusion: The size of the dysfunctional area on the cine MR images was well correlated with that of the unenhanced area on the MnDPDP-enhanced MR images.

We report a case of fetal pericallosal lipoma occurring at the anterior interhemispheric fissure and associated with agenesis of the corpus callosum. During targeted prenatal ultrasonography at 26 weeks' gestation, the lesion was seen as a highly echogenic mass. MR imaging performed at 35 weeks' gestation and during the postnatal period revealed a pericallosal fatty mass and agenesis of the corpus callosum.

It is well established that sarcopenic obesity (SO) is linked to many diseases such as metabolic and non-alcoholic fatty liver diseases, but there is little known about the relationship between SO and hepatic fibrosis progression in chronic liver disease. This study compared body composition contents in patients with non-obesity (NOb) and SO using abdominal magnetic resonance imaging and investigated the relationship between hepatic fibrosis and SO factors. This retrospective study enrolled 60 patients (28 NOb; 32 SO) from June 2014 to December 2020. Patients underwent histopathologic investigation where they classified fibrosis stages based on the Meta-analysis of Histological Data in Viral Hepatitis fibrosis scoring system. Muscle and fat areas at the third lumber vertebra level were assessed. The variation in the areas of muscle (MA), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) among fibrosis stages, and associations between hepatic fibrosis and SO factors, were analyzed. There were significant differences in SAT and VAT (p < 0.001), whereas there was no difference in MA (p = 0.064). There were significant differences in MA/SAT (p = 0.009), MA/VAT (p < 0.001), and MA/(SAT+VAT) (p < 0.001). In all the patients, hepatic fibrosis positively correlated with serum aspartate aminotransferase level (AST, R = 0.324; p = 0.025). Especially in SO patients, hepatic fibrosis closely correlated with body mass index (BMI, R = 0.443; p = 0.011), AST (R = 0.415; p = 0.044), VAT (R = 0.653; p < 0.001), MA/VAT (R = −0.605; p < 0.001), and MA/(SAT+VAT) (R = −0.416; p = 0.018). However, there was no association in NOb patients. This study demonstrated that SO patients had larger SAT and VAT than NOb patients. Hepatic fibrosis in SO positively correlated with body visceral fat composition in combination with BMI and AST level. These findings will be useful for understanding the relationship between the hepatic manifestation of fibrosis and body fat composition in sarcopenia and SO. [ABSTRACT FROM AUTHOR]

Background: The assessment of liver surface nodularity (LSN) for staging hepatic fibrosis is restricted in clinical practice because it requires customized software and time‐consuming procedures. A simplified method to estimate LSN score may be useful in the clinic. Purpose: To evaluate the regional analysis of LSN and processing time in a single axial liver MR image for staging liver fibrosis. Study Type: Retrospective. Population: A total of 210 subjects, a multicenter study. Field Strength/Sequence: A 3 T/noncontrast gradient echo T1WI. Assessment: Subjects were divided into five fibrosis groups (F0 = 29; F1 = 20; F2 = 32; F3 = 50; F4 = 79) based on the METAVIR fibrosis scoring system. The mean LSN (on three slices) and regional LSN (on one slice) measurements, and the processing times, are compared. The regional LSN scores in five regions‐of‐interests (ROI1‐5) were analyzed in a single axial MRI at the level of the hilum by two independent observers. Statistical Tests: Regional variations in LSN scores were compared using ANOVA with Tukey test. Agreement between the mean and regional LSN measurements was evaluated using Pearson correlation coefficients (r) and Bland–Altman plots. The diagnostic performance of mean and regional LSN scores according to fibrosis stage was evaluated with the AUROC. A P value < 0.05 was considered statistically significant. Results: Total processing time for a regional LSN measurement (3.6 min) was 75.5% less than that for mean LSN measurement (14.7 min). Mean LSN scores and all five regional LSN scores showed significant differences between fibrosis groups. Among regional LSN scores, ROI5 showed the highest AUROC (0.871 at cut‐off 1.12) for discriminating F0‐2 vs. F3‐4 and the best correlation with mean LSN score (r = 0.800, −0.07 limit of agreement). Conclusion: Quantitative regional LSN measurement in a single axial MR image reduces processing time. Regional ROI5 LSN score might be useful for clinical decision‐making and for distinguishing the difference between early fibrosis (F0‐2) and advanced fibrosis (F3−4) in the liver. Evidence Level: 3 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Post-annealing effects on microstructure and magnetic properties of Nd-Fe-B die-upset magnets were investigated using the commercial melt-spun flakes with a composition of Nd13.6Fe73.6Ga0.6Co6.6B5.6. The die-upset magnets from the melt-spun flakes were subjected to post-annealing at temperatures ranging from 400 °C to 800 °C for 1 h in vacuum and then again annealed at a constant temperature, 600 °C. The coercivity was largely enhanced about 2.4 kOe after the first post-annealing treatment at 600 °C. However, the coercivity decreased at temperatures except for 600 °C and 700 °C. In the case of high temperature, 800 °C, annealing caused the grain growth, resulting coercivity degradation. After the second post-annealing treatment at 600 °C, the coercivity of the magnets post-annealed at low temperatures below 500 °C increased, whereas the coercivity of the magnets post-annealed at above 700 °C decreased. The $\alpha $ and ${N} _{\mathrm {eff}}$ values obtained from the result of temperature dependence of coercivity increased after post-annealing at 600 °C. These results indicate that post-annealing at 600 °C was effective in improving the grain surface structure, but could induce the local stray field in the magnet. [ABSTRACT FROM AUTHOR]

Background: Myocardial fibrosis is an important prognostic factor in hypertrophic cardiomyopathy (HCM). However, the contribution from a wide spectrum of genetic mutations has not been well defined. We sought to investigate effect of sarcomere and mitochondria-related mutations on myocardial fibrosis in HCM. Methods: In 133 HCM patients, comprehensive genetic analysis was performed in 82 nuclear DNA (33 sarcomere-associated genes, 5 phenocopy genes, and 44 nuclear genes linked to mitochondrial cardiomyopathy) and 37 mitochondrial DNA. In all patients, cardiovascular magnetic resonance (CMR) was performed, including 16-segmental thickness, late gadolinium enhancement (LGE), native and post-T1, extracellular volume fraction (ECV), and T2, along with echo-Doppler evaluations. Results: Patients with sarcomere mutation (SM, n = 41) had higher LGE involved segment, % LGE mass, ECV and lower post-T1 compared to patients without SM (n = 92, all p < 0.05). When classified into, non-mutation (n = 67), only mitochondria-related mutation (MM, n = 24), only-SM (n = 36) and both SM and MM (n = 5) groups, only-SM group had higher ECV and LGE than the non-mutation group (all p < 0.05). In non-LGE-involved segments, ECV was significantly higher in patients with SM. Within non-SM group, patients with any sarcomere variants of uncertain significance had higher echocardiographic Doppler E/e' (p < 0.05) and tendency of higher LGE amount and ECV (p > 0.05). However, MM group did not have significantly higher ECV or LGE amount than non-mutation group. Conclusions: SMs are significantly related to increase in myocardial fibrosis. Although, some HCM patients had pathogenic MMs, it was not associated with an increase in myocardial fibrosis. [ABSTRACT FROM AUTHOR]

In sarcopenic obesity, the importance of evaluating muscle and fat mass is unquestionable. There exist diverse quantification methods for assessing muscle and fat mass by imaging techniques; thus these methods must be standardized for clinical practice. This study developed a quantification software for the body composition imaging using abdominal magnetic resonance (MR) images and compared the difference between sarcopenic obesity and healthy controls for clinical application. Thirty patients with sarcopenic obesity and 30 healthy controls participated. The quantification software was developed based on an ImageJ multiplatform and the processing steps are as follows: execution, setting, confirmation, and extraction. The variation in the muscle area (MA), subcutaneous fat area (SA), and visceral fat area (VA) was analyzed with an independent two sample T-test. There were significant differences in SA (p < 0.001) and VA (p = 0.011), whereas there was no difference in MA (p = 0.421). Regarding the ratios, there were significant differences in MA/SA (p < 0.001), MA/VA (p = 0.002), and MA/(SA + VA) (p < 0.001). Overall, intraclass correlation coefficients were higher than 0.9, indicating excellent reliability. This study developed customized sarcopenia-software for assessing body composition using abdominal MR images. The clinical findings demonstrate that the quantitative body composition areas and ratios can assist in the differential diagnosis of sarcopenic obesity or sarcopenia. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to assess the accuracy and stability of frameless gamma knife radiosurgery (GKRS). The accuracies of the radiation isocenter and patient couch movement were evaluated by film dosimetry with a half‐year cycle. Radiation isocenter assessment with a diode detector and cone‐beam computed tomography (CBCT) image accuracy tests were performed daily with a vendor‐provided tool for one and a half years after installation. CBCT image quality was examined twice a month with a phantom. The accuracy of image coregistration using CBCT images was studied using magnetic resonance (MR) and computed tomography (CT) images of another phantom. The overall positional accuracy was measured in whole procedure tests using film dosimetry with an anthropomorphic phantom. The positional errors of the radiation isocenter at the center and at an extreme position were both less than 0.1 mm. The three‐dimensional deviation of the CBCT coordinate system was stable for one and a half years (mean 0.04 ± 0.02 mm). Image coregistration revealed a difference of 0.2 ± 0.1 mm between CT and CBCT images and a deviation of 0.4 ± 0.2 mm between MR and CBCT images. The whole procedure test of the positional accuracy of the mask‐based irradiation revealed an accuracy of 0.5 ± 0.6 mm. The radiation isocenter accuracy, patient couch movement accuracy, and Gamma Knife Icon CBCT accuracy were all approximately 0.1 mm and were stable for one and a half years. The coordinate system assigned to MR images through coregistration was more accurate than the system defined by fiducial markers. Possible patient motion during irradiation should be considered when evaluating the overall accuracy of frameless GKRS. [ABSTRACT FROM AUTHOR]

Image co-registration is used in frameless gamma knife radiosurgery (GKSRS) to assign a stereotactic coordinate system and verify patient setup before irradiation. The accuracy of co-registration with cone beam computed tomography (CBCT) images of a Gamma Knife IconTM (GK Icon) was assessed, and the effects of the region of co-registration (ROC) were studied. CBCT-to-CBCT co-registration is used for patient setup verification, and its accuracy was examined by co-registering CBCT images taken at various configurations with a reference CBCT series. The accuracy of stereotactic coordinate assignment was investigated by co-registering stereotactic CT images with CBCT images taken at various configurations. An anthropomorphic phantom was used, and the coordinates of fifteen landmarks inside the phantom were measured. The co-registration accuracy between stereotactic magnetic resonance (MR) and CBCT images was evaluated using images from forty-one patients. The positions of the anterior and posterior commissures were measured in both a fiducial marker-based system and a co-registered system. To assess the effects of MR image distortions, co-registration was performed with four different ranges, and the accuracy of the results was compared. Co-registration between CBCT images gave a mean three-dimensional deviation of 0.2 ± 0.1 mm. The co-registration of stereotactic CT images with CBCT images produced a mean deviation of 0.5 ± 0.2 mm. The co-registration of MR images with CBCT images resulted in the smallest three-dimensional difference (0.8 ± 0.3 mm) when a co-registration region covering the skull base area was applied. The image co-registration errors in frameless GKSRS were similar to the imaging errors of frame-based GKSRS. The lower portion of the patient’s head, including the base of the skull, is recommended for the ROC. [ABSTRACT FROM AUTHOR]

This study was designed to identify potential radiosensitizing (RS) agents for combined radio- and chemotherapy in a murine model of human lung carcinoma, and to evaluate the in vivo effect of the RS agents using diffusion-weighted magnetic resonance imaging (DW-MRI). Radioresistance-associated genes in A549 and H460 cells were isolated on the basis of their gene expression profiles. Celastrol was selected as a candidate RS by using connectivity mapping, and its efficacy in lung cancer radiotherapy was tested. Mice inoculated with A549 carcinoma cells were treated with single ionizing radiation (SIR), single celastrol (SC), or celastrol-combined ionizing radiation (CCIR). Changes in radiosensitization over time were assessed using DW-MRI before and at 3, 6, and 12 days after therapy initiation. The tumors were stained with hematoxylin and eosin at 6 and 12 days after therapy. The percentage change in the apparent diffusion coefficient (ADC) value in the CCIR group was significantly higher than that in the SC and SIR group on the 12th day (Mann–Whitney U-test, p = 0.05; Kruskal–Wallis test, p < 0.05). A significant correlation (Spearman’s rho correlation coefficient of 0.713, p = 0.001) was observed between the mean percentage tumor necrotic area and the mean ADC values after therapy initiation. These results suggest that the novel radiosensitizing agent celastrol has therapeutic effects when combined with ionizing radiation (IR), thereby maximizing the therapeutic effect of radiation in non–small cell lung carcinoma. In addition, DW-MRI is a useful noninvasive tool to monitor the effects of RS agents by assessing cellularity changes and sequential therapeutic responses. [ABSTRACT FROM AUTHOR]

We investigated the microstructural and magnetic property changes of DyF3 dip-coated Nd-Fe-B sintered magnets as a function of the first post-sintering annealing (PSA) temperature and clarified the optimum first PSA temperature for the dip-coating process. Coercivity increased (from 26.7 to 29.06 kOe) with increasing first PSA temperature (from 700 to 900^\circC) owing to the increased diffusion depth of the Dy atoms. In the diffused region, the formation of the rare earth-rich phase (Nd-Dy-O) was suppressed and the core-shell microstructure was developed as a result of the DyF3 dip-coating process. However, coercivity decreased when the samples were annealed at 950^\circC because h-Nd2O3 phases were formed in the Cu-rich triple junction phase and the grain boundary phase. By contrast, the C-Nd2O3 phase, which is closely related to coercivity enhancement after second PSA, was formed in the magnet annealed at 900^\circC. The result fulfilled our basic aim of utilizing the DyF3 dip-coating process in order to enhance the coercivity of Nd-Fe-B sintered magnets without remanence reduction. [ABSTRACT FROM AUTHOR]

Magnetic and microstructural properties of (Nd26.06, Dy6.51)-Febal.-B0.97-M2.39 (wt.%) (M = Cu,\ Al,\ Co, and Nb) sintered magnets doped with Dy2O3 and DyF3 powders were studied. In the case of the Dy2O3-doped magnet, Dy was distributed along the near grain boundaries. In contrast, the DyF3-doped magnet and the undoped magnet showed that Dy was distributed uniformly in the main phase. The coercivity and the remanence of the Dy2O3 and DyF3-doped magnets were 33.2 kOe, 11.64 kG, and 34.5 kOe, 11.21 kG, respectively. The coercivity of the DyF3-doped magnet was the largest but its remanence was the smallest among other magnets because the Dy was distributed throughout the main phase. Uniform distribution of the Dy in the DyF3-doped magnet was probably due to their lower bonding energy and higher chemical potential for diffusion. [ABSTRACT FROM AUTHOR]

Simple Summary: Non-invasive quantification of radiation-induced damage is an important factor in radiation therapy to maximize radiation dose to cancer cells while minimizing damage to surrounding healthy tissue. Development of imaging biomarkers to assess post-RT effects accurately at an early stage is important for better prognosis and to individualize the management of brain tumors. Recent MR-based electrical conductivity imaging provides novel contrast information based on the concentration and mobility of ions constituting tissue and can exhibit high sensitivity in quantifying the therapeutic effect of ionizing radiation used in cancer treatment. This study suggests that the change in conductivity at different doses can provide a way to quantify the response of the tissue to irradiation, and the variation in conductivity with the elapsed time shows potential as a tool to monitor the therapeutic effect of radiation. Radiation-induced injury is damage to normal tissues caused by unintentional exposure to ionizing radiation. Image-based evaluation of tissue damage by irradiation has an advantage for the early assessment of therapeutic effects by providing sensitive information on minute tissue responses in situ. Recent magnetic resonance (MR)-based electrical conductivity imaging has shown potential as an effective early imaging biomarker for treatment response and radiation-induced injury. However, to be a tool for evaluating therapeutic effects, validation of its reliability and sensitivity according to various irradiation conditions is required. We performed MR-based electrical conductivity imaging on designed phantoms to confirm the effect of ionizing radiation at different doses and on in vivo mouse brains to distinguish tissue response depending on different doses and the elapsed time after irradiation. To quantify the irradiation effects, we measured the absolute conductivity of brain tissues and calculated relative conductivity changes based on the value of pre-irradiation. The conductivity of the phantoms with the distilled water and saline solution increased linearly with the irradiation doses. The conductivity of in vivo mouse brains showed different time-course variations and residual contrast depending on the irradiation doses. Future studies will focus on validation at long-term time points, including early and late delayed response and evaluation of irradiation effects in various tissue types. [ABSTRACT FROM AUTHOR]

Abstract: Jang SH, You SH, Hallett M, Cho YW, Park C-M, Cho S-H, Lee H-Y, Kim T-H. Cortical reorganization and associated functional motor recovery after virtual reality in patients with chronic stroke: an experimenter-blind preliminary study. Objective: To investigate the effects of virtual reality (VR) on cortical reorganization and motor recovery. Design: Nonparametric pre- and posttest design with experimenter blinded. Setting: University medical center. Participants: Five patients with hemiparesis (age, 59.8±3.4y) were recruited. Intervention: Five patients received VR for 60 minutes a day, 5 times a week for 4 weeks. VR was designed to provide a virtual rehabilitation scene where the intensity of practice and sensory feedback could be systematically manipulated to provide the most appropriate, individualized motor retraining program. Main Outcome Measures: Cortical activation and associated motor recovery were measured before and after VR using functional magnetic resonance imaging and standardized motor tests, respectively. Nonparametric tests were used at P less than .05. Results: Prior to VR, the bilateral primary sensorimotor cortices (SM1s), contralesional premotor cortex, and contralesional or ipsilesional supplementary motor area were activated. After VR, the altered activations disappeared and predominantly the ipsilesional SM1 was activated (P<.05). Motor function was improved (P<.05). Conclusions: This is a novel demonstration of VR-induced neuroplastic changes and associated motor recovery in chronic stroke. [Copyright &y& Elsevier]

Background: Inflammatory responses play a critical role in left ventricular remodeling after myocardial infarction (MI). Tolerogenic dendritic cells (tDCs) can modulate immune responses, inducing regulatory T cells in a number of inflammatory diseases.Methods: We generated tDCs by treating bone marrow-derived dendritic cells with tumor necrosis factor-α and cardiac lysate from MI mice. We injected MI mice, induced by a ligation of the left anterior descending coronary artery in C57BL/6 mice, twice with tDCs within 24 hours and at 7 days after the ligation.Results: In vivo cardiac magnetic resonance imaging and ex vivo histology confirmed the beneficial effect on postinfarct left ventricular remodeling in MI mice treated with tDCs. Subcutaneously administered infarct lysate-primed tDCs near the inguinal lymph node migrated to the regional lymph node and induced infarct tissue-specific regulatory T-cell populations in the inguinal and mediastinal lymph nodes, spleen, and infarcted myocardium, indicating that a local injection of tDCs induces a systemic activation of MI-specific regulatory T cells. These events elicited an inflammatory-to-reparative macrophage shift. The altered immune environment in the infarcted heart resulted in a better wound remodeling, preserved left ventricular systolic function after myocardial tissue damage, and improved survival.Conclusions: This study showed that tDC therapy in a preclinical model of MI was potentially translatable into an antiremodeling therapy for ischemic tissue repair. [ABSTRACT FROM AUTHOR]