Emiko Chiba

We report a case of refractory chylous ascites following nephroureterectomy and para-aortic lymphadenectomy for renal pelvic carcinoma, which was successfully treated with percutaneous lymphatic embolization. An 83-year-old man underwent nephroureterectomy with para-aortic lymph node dissection for renal pelvic carcinoma. Postoperatively, >1000 mL/day of chylous ascites was continuously drained. Despite conservative management, high-output ascites persisted. Transnodal lymphangiography via the inguinal lymph nodes and post-lymphangiographic CT revealed lymphatic leakage at the nephroureterectomy site. Percutaneous lymphatic embolization was planned as a minimally invasive procedure. Under CT guidance, embolization of a lymphopseudoaneurysm and para-aortic lymph nodes near the leakage site was successfully performed using N-butyl cyanoacrylate. Ascitic fluid output decreased significantly postoperatively, and the drainage tube was removed the following day. This case highlights the importance of post-lymphangiographic CT in identifying actionable lymphatic targets and demonstrates that an anatomically tailored dual-target embolization strategy can achieve effective sealing when central duct access is not feasible.

Pancreatic arteriovenous malformation (PAVM) is a rare vascular anomaly of the gastrointestinal tract, and the coexistence of a pseudoaneurysm is exceptionally uncommon. This report details a case of pseudoaneurysm associated with a massive PAVM that was successfully managed with endovascular therapy. A 67-year-old female patient with a massive PAVM presented with acute back pain. Contrast-enhanced computed tomography revealed a pseudoaneurysm in the pancreatic head accompanied by a surrounding haematoma. Transcatheter arterial embolisation (TAE) was selected as the minimally invasive treatment and the pseudoaneurysm was visualised on angiography. However, identifying the culprit artery was challenging due to the extensive vascular network of the PAVM. Following modification of the local haemodynamics using coil embolisation, the culprit artery became detectable, allowing successful embolisation of the pseudoaneurysm using N-butyl cyanoacrylate (NBCA). This case report highlights the clinical utility of NBCA embolisation combined with flow modification for managing a pseudoaneurysm associated with a massive PAVM, which represents an exceptionally rare vascular anomaly.

We present a rare case of type II endoleak (T2EL) from an atypical mediastinal artery following total arch replacement with a frozen elephant trunk (FET) for chronic aortic dissection. A 63-year-old male with a history of multiple thoracic aortic surgeries, including FET, developed enlargement of an aortic arch aneurysm on follow-up. Computed tomography and diagnostic angiography revealed a T2EL due to a newly developed mediastinal collateral artery arising from the left subclavian artery feeding the sac. Selective transcatheter embolization with N-butyl-2-cyanoacrylate successfully eliminated the endoleak. Recognizing such atypical T2EL sources is crucial for managing post-FET aneurysm expansion.

BACKGROUND AND PURPOSE: Bell’s palsy (BP) is the most common cause of facial nerve (FN) palsy. This study aimed to investigate the diagnostic ability of the 3D Double-Echo Steady-State with Water Excitation (3D-DESS-WE) sequence to visualize pathological changes in the FN of BP patients. MATERIALS AND METHODS: We retrospectively analyzed 30 BP patients who underwent 3T MRI including 3D-DESS-WE within 30 days of onset and 60 sex-and age±2-matched controls. Qualitative evaluation of FN signal intensity (SI_FN) and thickness (TH_FN) was performed using a 3-point scale. Quantitative metrics included SI_FN and TH_FN measurements and affected-to-unaffected ratios (SR_A/U and TR_A/U) in the BP group, and right-to-left ratios in controls. Interobserver agreement, group comparisons, correlations with clinical severity (Yanagihara score), and diagnostic performance were assessed. In a subset of 17 matched pairs, the diagnostic performance of contrast-enhanced T1WI (CE-T1WI) was assessed, and its agreement with 3D-DESS-WE-based qualitative assessment was evaluated. RESULTS: Qualitative scores for SI_FN and TH_FN were significantly higher in the BP group than in controls (P < .001), with high interobserver agreement (κ = 0.810, 0.788, respectively). When dichotomized (score 0 vs. 1–2), qualitative assessments showed good diagnostic performance with sensitivity and specificity of 0.87 and 0.82 for SI_FN, and 0.90 and 0.80 for TH_FN, respectively. Neither qualitative score correlated significantly with clinical severity. Agreement between 3D-DESS-WE-based and CE-T1WI-based qualitative assessments was substantial to almost perfect (κ = 0.766–0.882). In quantitative analysis, both SI_FN and TH_FN were significantly higher on the affected side in the BP group (P < .001), whereas no significant lateral differences were observed in controls. Although SI_FN, TH_FN, and SR_A/U did not correlate significantly with clinical severity, TR_A/U was significantly inversely correlated with the Yanagihara score (r = –0.413, P = .02), which corresponds to a positive correlation with clinical severity. The Yanagihara score was the only independent predictor for TR_A/U in multiple regression analysis (β = –0.425, P = .04). ROC analysis showed high diagnostic performance: AUC = 0.908 for SR_A/U and 0.927 for TR_A/U. CONCLUSIONS: 3D-DESS-WE may be a valuable tool for the routine clinical assessment of BP. ABBREVIATIONS: 3D-DESS-WE＝3D Double-Echo Steady-State with Water Excitation; 3D-PSIF＝3D reversed fast imaging in steady-state free precession.

BACKGROUND AND PURPOSE: Although various neuropsychological problems in Becker muscular dystrophy have attracted attention, there have been few related neuroimaging studies. We investigated brain abnormalities in patients with Becker muscular dystrophy using 3D T1WI and DTI. MATERIALS AND METHODS: MR images were obtained for 30 male patients and 30 age-matched healthy male controls. We classified patients into Dp140+ and Dp140− subgroups based on their predicted dystrophin Dp140 isoform expression and performed voxel-based comparisons of gray and white matter volumes and DTI metrics among the patients, patient subgroups, and controls. ROI-based DTI analyses were also performed. RESULTS: Significantly decreased fractional anisotropy was observed in the left planum temporale and right superior parietal lobule compared between the Becker muscular dystrophy and control groups. In the Dp140− subgroup, decreased fractional anisotropy was observed in the left planum temporale, but no significant changes were seen in the Dp140+ subgroup. The ROI-based analysis obtained the same results. No significant differences were evident in the gray or white matter volumes or the DTI metrics other than fractional anisotropy between the groups. CONCLUSIONS: A DTI metric analysis is useful to detect white-matter microstructural abnormalities in Becker muscular dystrophy that may be affected by the Dp140 isoform expression.

Introduction: Tau protein accumulation in the brain is thought to be one of the causes of progressive supranuclear palsy (PSP). The glymphatic system was discovered a decade ago as a waste drainage system in the brain that promotes the elimination of amyloid-beta and tau protein. We here evaluated the relationships between glymphatic system activity and regional brain volumes in PSP patients. Method: Subjects were 24 patients with PSP and 42 healthy participants who underwent diffusion tensor imaging (DTI). We computed the diffusion tensor image analysis along the perivascular space (DTI-ALPS) index as a proxy of glymphatic system activity and estimated the relationships between the DTI-ALPS index and regional brain volume in PSP patients by whole-brain and region-of-interest analyses, including analyses of the midbrain and third and lateral ventricles. Results: The DTI-ALPS index was significantly lower in patients with PSP compared with healthy subjects. Further, there were significant correlations between the DTI-ALPS index and the regional brain volumes in the midbrain tegmentum, pons, right frontal lobe, and lateral ventricles in patients with PSP. Conclusions: Our data suggest that the DTI-ALPS index is a good biomarker for PSP and might be effective to distinguish PSP from other neurocognitive disorders.

Recent developments in image analysis have enabled an individual’s brain network to be evaluated and brain age to be predicted from gray matter images. Our study aimed to investigate the effects of age and sex on single-subject gray matter networks using a large sample of healthy participants. We recruited 812 healthy individuals (59.3 ± 14.0 years, 407 females, and 405 males) who underwent three-dimensional T1-weighted magnetic resonance imaging. Similarity-based gray matter networks were constructed, and the following network properties were calculated: normalized clustering, normalized path length, and small-world coefficients. The predicted brain age was computed using a support-vector regression model. We evaluated the network alterations related to age and sex. Additionally, we examined the correlations between the network properties and predicted brain age and compared them with the correlations between the network properties and chronological age. The brain network retained efficient small-world properties regardless of age; however, reduced small-world properties were observed with advancing age. Although women exhibited higher network properties than men and similar age-related network declines as men in the subjects aged < 70 years, faster age-related network declines were observed in women, leading to no differences in sex among the participants aged ≥ 70 years. Brain age correlated well with network properties compared to chronological age in participants aged ≥ 70 years. Although the brain network retained small-world properties, it moved towards randomized networks with aging. Faster age-related network disruptions in women were observed than in men among the elderly. Our findings provide new insights into network alterations underlying aging.

Alzheimer’s disease (AD), the most common type of dementia in elderly individuals, slowly and progressively diminishes the cognitive function. Mild cognitive impairment (MCI) is also a significant risk factor for the onset of AD. Magnetic resonance imaging (MRI) is widely used for the detection and understanding of the natural progression of AD and other neurodegenerative disorders. For proper assessment of these diseases, a reliable database of images from cognitively healthy participants is important. However, differences in magnetic field strength or the sex and age of participants between a normal database and an evaluation data set can affect the accuracy of the detection and evaluation of neurodegenerative disorders. We developed a brain segmentation procedure, based on 30 Japanese brain atlases, and suggest a harmonized Z-score to correct the differences in field strength and sex and age from a large data set (1235 cognitively healthy participants), including 1.5 T and 3 T T1-weighted brain images. We evaluated our harmonized Z-score for AD discriminative power and classification accuracy between stable MCI and progressive MCI. Our procedure can perform brain segmentation in approximately 30 min. The harmonized Z-score of the hippocampus achieved high accuracy (AUC = 0.96) for AD detection and moderate accuracy (AUC = 0.70) to classify stable or progressive MCI. These results show that our method can detect AD with high accuracy and high generalization capability. Moreover, it may discriminate between stable and progressive MCI. Our study has some limitations: the age groups in the 1.5 T data set and 3 T data set are significantly different. In this study, we focused on AD, which is primarily a disease of elderly patients. For other diseases in different age groups, the harmonized Z-score needs to be recalculated using different data sets.