Transcranial MR-guided focused ultrasound surgery (TcMRgFUS) is recognized as a minimally invasive treatment method for essential tremor (ET), a condition characterized by involuntary motor disturbances. The target region for treating ET is the ventral intermediate (Vim) nucleus of the thalamus, which is surrounded by the ventral caudal nuclei (Vc) and the pyramidal tract (PT).

　While an indirect methodology based on the anatomical atlas and anterior commissure-posterior commissure (AC-PC) line is commonly used for TcMRgFUS targeting, it may not always provide adequate precision due to individual variations in nucleus localization.

　A direct approach utilizing diffusion tensor imaging (DTI) has been proposed to achieve highly accurate targeting. However, the visualization efficacy of fiber tracts varies depending on the algorithm of the analysis used. The generalized q-sampling imaging (GQI) algorithm is reputed to outperform the DTI algorithm in terms of accuracy.

　Leveraging the GQI-based fiber tractography for TcMRgFUS targeting holds promise for providing exceptionally precise treatment outcomes, which is crucial for enhancing the overall efficacy of the procedure.

　New techniques for high-resolution diffusion-weighted imaging (DWI) have emerged, including reduced field-of-view DWI (rFOV-DWI) and multiplexed sensitivity encoding DWI (MUSE-DWI). These advanced technologies address the limitations of conventional DWI by reducing distortion and providing higher spatial resolution. Particularly, DWI is now a crucial imaging tool in gynecology for diagnosing endometrial and cervical cancer. This article offers an overview of the principles and clinical applications of rFOV-DWI and MUSE-DWI for endometrial and cervical cancer in gynecology.

　In 2022, a follow-up survey was conducted to the National Survey on Safety Management of MRI Examinations carried out in 2018. This study aimed to compare the two surveys to determine how the “Guidelines for the Safe Operation of Clinical MRI” affect the safe management of MRI examinations in clinical practice, and to identify factors associated with incidents affecting patient health. Automated machine learning was used to identify factors associated with major incidents. Of the 5,816 medical facilities we approached, 2,668 (45.9%) provided full or partial responses, with 2,582 (44.4%) valid responses. Although the number of facilities that participated in the survey and provided valid responses had increased by 567 from the previous survey, the response to safety management varied again in this survey. On the other hand, improvement was seen on most items related to safety management and MRI exam operations. Between October 2020 and September 2021, 242 major incidents occurred at 166 facilities (6%), a 1% increase from 2018. Most of these were related to contrast administration. Minor incidents also increased by 5% (2,068 incidents) at 833 facilities (32%). The largest contributor to the increase in major incidents was the number of examinations per month. Although there was wide variation in the safety standards applied by Japanese facilities performing clinical MRI examinations, facility responses improved for most items related to the safe management and operation of MRI scans.

　Golden Angle Radial Sparse Parallel-Volumetric Interpolated Breath hold Examination (GRASP-VIBE) using compressed sensing and golden-angle radial sampling is a gradient echo (GRE) sequence that provides an inflow effect. The purpose of this study was to investigate parameters for non-contrast visualization of the renal artery using GRASP-VIBE with respiratory synchronization by the liver gate. We used a flow phantom and a self-made phantom to determine effective fat suppression methods and appropriate settings for repetition time (TR) and flip angle (FA). We also performed imaging on five healthy volunteers and compared the ability to visualize the renal artery. In the phantom study, water excitation showed the highest fat suppression effect ; the flow phantom was well visualized at TR 7.2 ms～9.0 ms and FA 9°～13°. In the volunteer study, the renal artery was best visualized at TR 7.2 ms and FA 13°. The results suggest that GRASP-VIBE can be used to visualize the renal artery without contrast enhancement by using the parameter settings examined in this study.

　Recent studies have reported an increase in the incidence of lower extremity arterial disease in Japan secondary to rapid population aging and an increase in the numbers of diabetes and dialysis cases. Although widely used, the long-term outcomes of endovascular therapy (EVT) remain unclear. Regular evaluation to monitor restenosis is extremely important. Magnetic resonance angiography is a non-invasive approach to evaluate lower extremity arteries without contrast enhancement or radiation exposure. However, stent lumens present challenges for evaluation in some cases secondary to magnetic susceptibility artifacts. Previous studies have reported the usefulness of the volume isotropic turbo spin-echo (T1 VISTA) method, which is based on three-dimensional variable refocusing flip angle turbo spin echo images for in-stent evaluation after carotid artery stenting. In this study, we describe our findings in two patients in whom the T1 VISTA method was useful to evaluate leg artery stent patency following EVT.