Masayuki Maeda

Purpose: The aim of this study was to compare the contributions of putative glymphatic-related imaging indices—diffusion-weighted image analysis along the perivascular space (DWI-ALPS) index and choroid plexus volume (CPV)—and total cortical gray matter volume (TCGMV) to cognitive function in cerebral amyloid angiopathy (CAA). Methods: Forty-four CAA patients and 22 controls underwent 3.0T MRI. Cognitive function was assessed by the Mini-Mental State Examination (MMSE). The mean DWI-ALPS index, CPV/intracranial volume (ICV), and TCGMV/ICV were compared between groups; hierarchical multivariable regression and mediation analyses evaluated MMSE correlates. Results: Compared with controls, CAA showed a lower mean DWI-ALPS index and TCGMV/ICV (both adjusted p < 0.05), whereas CPV/ICV did not differ significantly after adjustment. In hierarchical multivariable regression analysis, mean DWI-ALPS index was associated with MMSE before adjustment for TCGMV/ICV (p = 0.022), but this association was attenuated after TCGMV/ICV was added to the model (p = 0.665). CPV/ICV was not associated with MMSE in either model, whereas TCGMV/ICV was independently associated with MMSE (p = 0.013). Exploratory mediation analysis suggested an indirect association between mean DWI-ALPS and MMSE via TCGMV/ICV (indirect: p = 0.023; direct: p = 0.720). Conclusions: Cortical atrophy appeared to be the strongest imaging correlate of cognitive impairment in CAA, while the association between DWI-ALPS and MMSE in multivariable models was attenuated after accounting for cortical gray matter volume. The ALPS index may provide indirect information on glymphatic-related pathways, but its biological specificity in CAA requires cautious interpretation because ALPS measurements may be influenced by underlying microstructural alterations in white matter.

Purpose To clarify the ability of the preoperative CT Hounsfield units (HU) of the vertebrae and MRI-based vertebral bone quality (VBQ) score in predicting screw loosening following lumbar interbody fusion. Methods Patients with lumbar degenerative disease who underwent single-level lumbar interbody fusion at five hospitals were enrolled. The HU were assessed at vertebral body and pedicle. The VBQ score was assessed on the T1-weighted sagittal image and defined as the quotient of the median signal intensity of the vertebrae from L1 to L4 divided by the signal intensity of the cerebrospinal fluid. Screw loosening was evaluated by the postoperative CT scans at 12 months or more. Patients were divided into the screw loosening group and no loosening group, and the HU and the VBQ score were compared between the groups. Results A total of 107 patients (mean age, 67.8 ± 10.1 years, 62 men) were included. At the vertebral body, the HU of L1, the average HU from L1 to L4, from L1 to L5, and from L1 to S1, and the HU of the upper instrumented vertebra showed a statistically significant difference between the two groups. The average HU of the vertebral body from L1 to L4 showed the highest AUC of 0.651 and sensitivity of 0.818. No significant difference was found in the HU of the pedicle and VBQ score. Conclusion The preoperative CT HU of the vertebral bodies could reliably predict screw loosening following lumbar interbody fusion. In contrast, the VBQ score did not predict screw loosening.

Background/Objectives: A subtype of cerebral amyloid angiopathy (CAA), iatrogenic CAA (iCAA), has been increasingly reported. iCAA occurs primarily in patients who underwent surgery during childhood and is caused by the prion-like propagation of amyloid beta. This subtype of CAA tends to develop at a younger age than age-related CAA, usually before the age of 55. After a latency period of 20–40 years following surgery, it manifests as lobar intracerebral hemorrhage (ICH), cognitive impairment, or transient focal neurological episodes. Between 2023 and 2024, we observed four cases of possible iCAA, all of which had a history of neurosurgery during childhood. Case presentation: MRI findings for all cases revealed multiple lobar microbleeds. Two cases also showed cortical superficial siderosis and lobar ICH. Notably, contrast-enhanced 3D FLAIR demonstrated sulcal enhancement in two cases, and CT demonstrated cortical calcification in the bilateral posterior lobes in one case. Conclusions: Sulcal enhancement on contrast-enhanced 3D FLAIR and cortical calcification in the bilateral posterior lobes on CT may suggest advanced CAA in the present cases.

Background/Objectives: Recent studies indicate extensive shared white matter (WM) abnormalities between bipolar disorder (BD) and schizophrenia (SZ). However, the heterogeneity of WM in BD in terms of the presence of psychosis remains a critical issue for exploring the boundaries between BD and SZ. Previous studies comparing WM microstructures in psychotic and nonpsychotic BDs (PBD and NPBD) have resulted in limited findings, probably due to subtle changes, emphasizing the need for further investigation. Methods: Diffusion tensor imaging measures were obtained from 8 individuals with PBD, 8 with NPBD, and 22 healthy controls (HC), matched for age, gender, handedness, and educational years. Group comparisons were conducted using tract-based spatial statistics (TBSS). The most significant voxels showing differences between PBD and HC in the TBSS analyses were defined as a TBSS-ROI and subsequently analyzed. Results: Increased radial diffusivity (RD) in PBD compared to NPBD (p < 0.006; d = 1.706) was observed in TBSS-ROI, distributed in the confined regions of some WM tracts, including the body of the corpus callosum (bCC), the left genu of the CC (gCC), and the anterior and superior corona radiata (ACR and SCR). Additionally, NPBD exhibited significant age-associated RD increases (R² = 0.822, p < 0.001), whereas the greater RD observed in PBD compared to NPBD remained consistent across middle age. Conclusions: Preliminary findings from this small sample suggest severe frontal WM disconnection in the anterior interhemispheric communication, left fronto-limbic circuits, and cortico-striatal-thalamic loop in PBD compared to NPBD. While these results require replication and validation in larger and controlled samples, they provide insights into the pathophysiology of PBD, which is diagnostically located at the boundary between BD and SZ.

A novel imaging technique, CT-like MRI, specifically Fast Field Echo Resembling a CT Using Restricted Echo-spacing (FRACTURE), has been developed to depict bones. The purpose of this study is to evaluate the feasibility of FRACTURE MRI in cranial and facial bone lesions. Our results suggest that FRACTURE MRI can be used in addition to conventional MRI to evaluate a variety of pathologies of the cranial and facial bones.

Purpose: To evaluate the amide proton transfer (APT), tumor blood flow (TBF), and apparent diffusion coefficient (ADC) combined diagnostic value for differentiating intracranial malignant tumors (MTs) from benign tumors (BTs) in young patients, as defined by the 2021 World Health Organization classification of central nervous system tumors. Methods: Fifteen patients with intracranial MTs and 10 patients with BTs aged 0–30 years underwent MRI with APT, pseudocontinuous arterial spin labeling (pCASL), and diffusion-weighted imaging. All tumors were evaluated through the use of histogram analysis and the Mann–Whitney U test to compare 10 parameters for each sequence between the groups. The diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. Results: The APT maximum, mean, 10th, 25th, 50th, 75th, and 90th percentiles were significantly higher in MTs than in BTs; the TBF minimum (min) was significantly lower in MTs than in BTs; TBF kurtosis was significantly higher in MTs than in BTs; the ADC min, 10th, and 25th percentiles were significantly lower in MTs than in BTs (all p < 0.05). The APT 50th percentile (0.900), TBF min (0.813), and ADC min (0.900) had the highest area under the curve (AUC) values of the parameters in each sequence. The AUC for the combination of these three parameters was 0.933. Conclusions: The combination of APT, TBF, and ADC evaluated through histogram analysis may be useful for differentiating intracranial MTs from BTs in young patients.

We observed a new SWI finding, “cortical brush sign,” that represents prominent venous structures in the cortex of patients with acute cerebral infarct with or without moyamoya disease and cerebral venous thrombosis. The cortical brush sign disappeared on follow-up SWI in all cases. Cortical brush sign may help to understand the pathophysiology of venous structures in the cortex at acute phase.