Magnetic resonance imaging can enhance the specificity of imaging diagnoses owing to its high contrast and resolution, surpassing the advantages of computed tomography, which is characterized by high spatial resolution. However, because of the various imaging techniques available, understanding the characteristics of each imaging method and signals produced by each method is essential for making accurate diagnoses. This study outlines the fundamental imaging sequences necessary for evaluating hepatic focal lesions mentioned in imaging diagnostic guidelines (T1-weighted, chemical shift, fat-suppressed T2-weighted, and diffusion-weighted imaging) and imaging sequences that contribute to the qualitative diagnosis of the upper abdomen (particularly the liver), such as heavy T2-weighted imaging and the 6-point Dixon method. This study focuses on non-contrast images and provides essential foundational knowledge based on actual cases.

　Purpose : This study evaluated the potential of fast field echo resembling a computed tomography using restricted echo-spacing (FRACTURE) for meniscus assessment by comparing it with three-dimensional T2^＊weighted imaging (3D T2^＊WI).

　Method : The study examined 28 knees in 24 patients (average age : 59.5 years, eight males and 16 females), including four bilateral knee scans. Imaging was performed using 3D T2^＊WI and FRACTURE. Both sequences were compared through visual evaluation by two radiologists and using contrast-to-noise ratio (CNR) analysis. Statistical significance was determined for the observed differences. Visual assessment was conducted by two radiologists, who evaluated the medial and lateral menisci by scoring the degree of meniscal damage on a scale of 1 to 5. CNR was calculated for the healthy meniscus and adjacent articular cartilage using the root mean square (RMS)–CNR method. Additionally, CNR was calculated for meniscal tears using RMS-CNR.

　Results : Visual evaluation did not show a statistically significant difference between the two sequences for the medial and lateral menisci.

　FRACTURE demonstrated a statistically higher CNR for the healthy meniscus and adjacent articular cartilage than 3D T2^＊WI. However, no statistically significant difference was observed between the two sequences in the CNR of meniscal tears and adjacent articular cartilage.

　Conclusion : The findings indicate that FRACTURE is comparable to 3D T2^＊WI in diagnosing meniscal injuries.

　This study highlights the correlation between tumor location and prognosis in IDH wild-type glioblastoma, revealing areas associated with better or worse outcomes. These insights can guide clinicians in tailoring treatment plans, potentially improving glioblastoma patient management.

　Objective/Background : Multiple sclerosis (MS) shows a gradient of periventricular white matter damage, especially close to the ventricles. Although evaluating this gradient has demonstrated its usefulness in understanding microstructural changes in MS, assessments have primarily used nonspecific imaging techniques, such as two-dimensional magnetization transfer ratio and T1 maps. This study examined the periventricular gradient of myelin content using myelin volume fraction (MVF) maps, axion volume fraction (AVF) maps, and g-ratio in healthy controls, relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and neuromyelitis optica spectrum disorders (NMOSD).

　Methods : Synthetic magnetic resonance imaging (MRI) and 2-shell DWI on a 3-T scanner were performed in 23 healthy controls and 88 RRMS, 18 SPMS, 30 MOGAD, and 23 NMOSD participants. MVF, AVF, and g-ratio data were obtained from lesions identified using fluid-attenuated inversion recovery on synthetic MRI. The normal-appearing white matter bands extending from the ventricle to the cortex were evaluated, and the first 10 bands were analyzed. Periventricular gradients of the MVF, AVF, and g-ratio were compared among the groups using the Kruskal-Wallis test. Correlations between periventricular gradient and expanded disability status scale (EDSS) or disease duration (DD) were assessed using Spearman’s correlation coefficients.

　Results : The periventricular gradient of MVF was significantly higher in the RRMS and SPMS groups than that in healthy controls (p＝0.042 and p＜0.001, respectively) and significantly higher in the SPMS group than that in the RRMS group (p＝0.011). No significant differences were observed between healthy controls and patients with MOGAD or NMOSD or between the groups regarding AVF and g-ratio. In RRMS and SPMS combined, the periventricular gradient of MVF was significantly correlated with EDSS and DD.

　Conclusion : Demyelination in MS was more prominent close to the ventricles, with a gradient correlating with clinical severity, possibly aiding in differentiating MS from MOGAD and NMOSD.

　Recently, we developed a novel method to quantitatively evaluate amyloid plaques in the brain using magnetic resonance imaging (MRI) phase information, called double gaussian analysis (DGA). DGA nonlinearly evaluates the phase distribution of iron because of aging (aging iron) and iron in the amyloid plaque (amyloid iron), which is always lower than that of aging ; therefore, it sometimes provides an erroneous solution of the phase distribution of amyloid iron. Contrastingly, DGA provides the phase distribution of aging iron as a stable solution. Here, we used the phase information of aging iron to define brain regions representing cognitive brain function in participants with mild cognitive impairment. MRI were performed using 3T-MRI and phase images were derived in the DICOM format. We segmented the brains of participants into brain regions using the AAL atlas and integrated left and right brain regions into 85 regions and carefully selected as regions of interest (ROI) based on the following selection criteria : the average number of voxels is ＞3000, the region is related to cognitive function, and exceeded iron loading is previously known (exclusion criterion). We selected 17 ROIs for evaluation in this study and set the threshold between the cognitive decline and maintained groups as 27/26 in mini-mental state examination and derived the quantitative value as the change rate in TE after applying DGA. We found that the inferior parietal gyrus, excluding the angular gyrus and supramarginal gyrus, could discriminate only between the cognitive maintained and decline groups (p＜0.05). Quantitative values of the fusiform gyrus, insula, inferior temporal gyrus, and precuneus subtracted from the inferior parietal gyrus showed significant differences between cognitive decline and maintained groups (p＜0.05).