Yoshikazu Okamoto

Smooth muscle tumors of uncertain malignant potential and leiomyosarcomas of the uterus: MR findings

To study the MR characteristics of nonbenign uterine smooth muscle tumors.

Radiofrequency Ablation of the Liver: Determination of Ablative Margin at MR Imaging with Impaired Clearance of Ferucarbotran—Feasibility Study

Institutional review board approval and informed consent were obtained. The feasibility of magnetic resonance (MR) imaging with impaired clearance of ferucarbotran to visualize ablated liver parenchyma surrounding a tumor (ablative margin [AM]) was evaluated after radiofrequency (RF) ablation of the liver. Twenty-one patients with hepatocellular carcinomas underwent RF ablation 2-7 hours after ferucarbotran-enhanced MR imaging. On unenhanced T2*-weighted images acquired after 3-5 days, AMs appeared as hypointense rims. The AM status was related to incidence of residual or recurrent tumors. This technique is feasible for visualization of AM and prediction of residual or recurrent tumors after RF ablation of the liver.

Malignant or borderline mucinous cystic neoplasms have a larger number of loculi than mucinous cystadenoma: A retrospective study with MR

To determine whether there is any correlation between the number of loculi and the pathological grade of malignancy in mucinous cystic tumors of the ovary.

A decidualized endometrial cyst in a pregnant woman: a case observed with a steady-state free precession imaging sequence

Decidual changes of the ectopic endometrial stroma during pregnancy are well known among pathologists and obstetricians. However, they appear very similar to endometrial cysts with malignant transformation when imaged. Balanced fast field echo (BFFE) is a steady-state free precession imaging sequence and its contrast is decided by the T1/T2 ratio. The authors report a case of a decidualized endometrial cyst in which mural nodules were isointense with the nomotopic decidualized endometrium on T1- and T2-weighted images and BFFE. Isointensity with the nomotopic endometrium is an MR characteristic that can differentiate a decidualized endometrial cyst from malignant transformation. BFFE is a good alternative sequence during pregnancy because of its shorter acquisition time and lower radiofrequency absorption.

High-Intensity Aerobic Exercise Improves Both Hepatic Fat Content and Stiffness in Sedentary Obese Men with Nonalcoholic Fatty Liver Disease

We compared the effects of 12-week programs of resistance training (RT), high-intensity interval aerobic training (HIAT), and moderate-intensity continuous aerobic training (MICT). The primary goal was to evaluate the therapeutic effects of the exercise modalities for the management of nonalcoholic fatty liver disease (NAFLD). A total of 61 sedentary obese men with NAFLD were randomized into one of the following exercise regimens (RT, HIAT, or MICT). Hepatic fat content was decreased to a similar extent in the RT, HIAT, and MICT groups (−14.3% vs. −13.7% vs. −14.3%) without significant changes in weight and visceral fat. The gene expression levels of fatty acid synthesis were significantly decreased in the subjects’ monocytes. Hepatic stiffness was decreased only in the HIAT group (−16.8%). The stiffness change was associated with restored Kupffer cell phagocytic function (+17.8%) and decreased levels of inflammation such as leptin (−13.2%) and ferritin (−14.1%). RT, HIAT, and MICT were equally effective in reducing hepatic fat content, but only HIAT was effective in improving hepatic stiffness and restoring Kupffer cell function. These benefits appeared to be independent of detectable weight and visceral fat reductions; the benefits were acquired through the modulation of in vivo fatty acid metabolism and obesity-related inflammatory conditions.

Correlation of Histopathology With Magnetic Resonance Imaging in Kienböck Disease

PURPOSE Diagnosis and treatment remain controversial for Kienböck disease. A few reports have correlated magnetic resonance imaging (MRI), which is essential for early diagnosis, and histopathology of Kienböck biopsy specimens, but histopathological correlations of whole lunate bones or histological slices compared with MRI images are lacking. The purpose of this study was to compare presurgical MRI scans with corresponding histological slices of Kienböck-diseased lunates. METHODS We excised whole lunates at the time of surgery from 6 patients with Kienböck disease (stage IIIB) undergoing tendon-ball replacement or a Graner procedure. We stained paraffin-embedded, coronally sectioned specimens with hematoxylin-eosin and compared them with presurgical coronal scans using MRI with a 47-mm microscopy surface coil. RESULTS Toward the center of the lunates, the signal intensity in the proton density-weighted images was reduced, whereas the dorsal and palmar sides of the lunates exhibited no changes in intensity. In correlation, histopathological findings revealed strongly disrupted trabeculae toward the center of the lunates and intact trabeculae in the dorsal side of the lunates. Likewise, the necrotic and vitalized bone exhibited low and high signal intensities, respectively, in the proton density-weighted images; however, in the fast-field echo images, there were no correlations with histopathological observations. CONCLUSIONS Proton density-weighted MRIs but not fast-field echo images using a 47-mm microscopy coil reflected the extent and localization of the necrotic area in Kienböck-diseased lunates, as evidenced by comparison with histological analyses of the lunate specimens. CLINICAL RELEVANCE Proton density-weighted MRIs accurately reflect the vascular status of the lunate and may help plan treatment on a case-by-case basis.

Acceleration training for managing nonalcoholic fatty liver disease: a pilot study

Background While aerobic training is generally recommended as therapeutic exercise in guidelines, the effectiveness of resistance training has recently been reported in the management of nonalcoholic fatty liver disease (NAFLD). Acceleration training (AT) is a new training method that provides a physical stimulation effect on skeletal muscles by increasing gravitational acceleration with vibration. AT has recently been indicated as a component of medicine. In this study, we evaluated the effectiveness of AT in the management of NAFLD in obese subjects. Methods A total of 18 obese patients with NAFLD who had no improvement in liver function test abnormalities and/or steatosis grade after 12 weeks of lifestyle counseling were enrolled in an AT program. These patients attended a 20-minute session of AT twice a week for 12 consecutive weeks. Results During the AT program, the NAFLD patients showed a modest increase in the strength (+12.6%) and cross-sectional area (+3.1%) of the quadriceps, coupled with a significant reduction in intramyocellular lipids (−26.4%). Notably, they showed a modest reduction in body weight (−1.9%), abdominal visceral fat area (−3.4%), and hepatic fat content (−8.7%), coupled with a significant reduction in levels of aminotransferase (−15.7%), γ-glutamyltransferase (−14.4%), leptin (−9.7%), interleukin-6 (−26.8%), and tumor necrosis factor-α (−17.9%), and a significant increase of adiponectin (+8.7%). On a health-related quality of life survey, the patients showed an improvement in physical functioning (+17.3%), physical role (+9.7%), general health (+22.1), and social functioning (+6.0%). Conclusion AT reduced hepatic and intramyocellular fat contents and ameliorated liver function test abnormalities in obese patients with NAFLD, which was coupled with improved physical function and body adiposity. AT is clinically beneficial for the management of NAFLD.

Changes in diffusion tensor imaging (DTI) eigenvalues of skeletal muscle due to hybrid exercise training

Several studies have proposed the cell membrane as the main water diffusion restricting factor in the skeletal muscle cell. We sought to establish whether a particular form of exercise training (which is likely to affect only intracellular components) could affect water diffusion. The purpose of this study is to characterise prospectively the changes in diffusion tensor imaging (DTI) eigenvalues of thigh muscle resulting from hybrid training (HYBT) in patients with non-alcoholic fatty liver disease (NAFLD). Twenty-one NAFLD patients underwent HYBT for 30 minutes per day, twice a week for 6 months. Patients were scanned using DTI of the thigh pre- and post-HYBT. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), the three eigenvalues lambda 1 (λ1), λ2, λ3, and the maximal cross sectional area (CSA) were measured in bilateral thigh muscles: knee flexors (biceps femoris (BF), semitendinosus (ST), semimembranous (SM)) and knee extensors (medial vastus (MV), intermediate vastus (IV), lateral vastus (LV), and rectus femoris (RF)), and compared pre- and post-HYBT by paired t-test. Muscle strength of extensors (P<0.01), but not flexors, increased significantly post-HYBT. For FA, ADC and eigenvalues, the overall picture was of increase. Some (P<0.05 in λ2 and P<0.01 in λ1) eigenvalues of flexors and all (λ1-λ3) eigenvalues of extensors increased significantly (P<0.01) post-HYBT. HYBT increased all 3 eigenvalues. We suggest this might be caused by enlargement of muscle intracellular space.

Therapeutic effect of hybrid training of voluntary and electrical muscle contractions in middle-aged obese women with nonalcoholic fatty liver disease: a pilot trial

Background Exercise training is an effective therapy for nonalcoholic fatty liver disease (NAFLD). Hybrid training (HYB) of voluntary and electrical muscle contractions was developed to prevent disuse atrophy during space flight. HYB can be applied to obtain a strength training effect accompanying articular movement. In this pilot study, we aimed to investigate the therapeutic efficacy of HYB in NAFLD. Methods A total of 15 middle-aged obese women with NAFLD who had no improvement in serum alanine aminotransferase levels and/or liver fat deposition after 12 weeks of lifestyle counseling participated in an HYB program. HYB of the quadriceps and hamstrings was conducted for 20 minutes twice a week for 24 weeks. Results NAFLD patients showed attenuated intramyocellular lipid levels in the quadriceps after the HYB intervention (−15.5%). Levels of leptin (−17.4%), tumor necrosis factor-α (−23.2%), and interleukin-6 (−30.5%) were also decreased after the intervention. HYB led to a significant body weight reduction (−4.7%), which in turn was associated with a significant decrease in serum alanine aminotransferase (−35.8%), gamma-glutamyl transpeptidase (−21.6%), ferritin (−16.0%), oxidative stress (−17.8%) levels, and insulin resistance values (−2.7%). Conclusion In NAFLD, HYB exerts an antiobesity effect and attenuates liver dysfunction and insulin resistance in association with an increase in muscle strength and a decrease in ectopic muscle fat. Therefore, HYB has great potential as a new type of exercise therapy for liver disease in patients with NAFLD.

Multifocal peripheral nerve involvement associated with multiple myeloma

Infiltration of myeloma cells along the peripheral nerve is extremely rare, while multiple myeloma occasionally infiltrates the central nervous system. We present details of a patient in whom multiple myeloma had infiltrated a branch of the femoral nerve of the right inguinal region as well as the left ulnar nerve. The infiltration formed soft tissue masses, with the thickened nerves shown to be penetrating the center of the masses on ultrasonography and magnetic resonance imaging.