Search

Objectives: This study aimed to assess the feasibility of pancreatic steatosis quantification by automated whole-volume measurement of the fat fraction of the pancreas on CT in comparison to MRI using proton-density fat fraction (PDFF) techniques. Methods: Fifty-nine patients who underwent both CT and MRI were analyzed. Automated whole-volume measurement of pancreatic fat on unenhanced CT was performed by a histogram analysis with local thresholding. Three sets of CT fat volume fraction (FVF) (%) values with thresholds of −30 Hounsfield unit (HU), −20 HU and −10 HU were compared to MR-FVF (%) values measured on a PDFF map. Results: The median −30 HU CT-FVF, −20 HU CT-FVF, −10 HU CT-FVF and MR-FVF values of the pancreas were 8.6% (interquartile range (IQR), 11.3), 10.5% (IQR, 13.2), 13.4% (IQR, 16.1) and 10.9% (IQR, 9.7), respectively. The −30 HU CT-FVF (%), −20 HU CT-FVF (%) and −10 HU CT-FVF (%) of the pancreas showed a significant positive correlation with the MR-FVF (%) of the pancreas (ρ = 0.898, p < 0.001, ρ = 0.905, p < 0.001, ρ = 0.909, p < 0.001, respectively). The −20 HU CT-FVF (%) displayed reasonable agreement with the MR-FVF (%) with a low absolute fixed bias (mean difference, 0.32%; limit of agreement from −10.1 to 10.7%). Conclusion: The automated whole-volume measurement of the CT fat fraction of the pancreas using the threshold CT attenuation value of −20 HU may be a feasible, non-invasive, and convenient technique for quantifying pancreatic steatosis. Advances in knowledge: CT-FVF value of the pancreas had a positive correlation with the MR-FVF value. The −20 HU CT-FVF may be a convenient technique for quantifying pancreatic steatosis.

The first step in endovascular treatment is the stable placement of a guide catheter (GC) into the target parent vessel. However, sufficient GC stabilization is sometimes difficult to obtain when the approach route has severe tortuosity. Here, we report our experience with and the usefulness of the 8 French (Fr) Newton-shaped Neuro-EBU vascular catheter (SILUX Co., Ltd., Kawaguchi City, Saitama Prefecture, Japan), which is rigid over its entire length except near the tip, in a case series of 21 patients. Of the 21 cases, 19 cases were successfully treated using the Neuro-EBU. The 8 Fr Newton-shaped Neuro-EBU might be useful both as a special GC and as a wire exchange catheter when placement of the conventional GC is difficult due to severe tortuosity of the access route. Although rarely used, the Neuro-EBU catheter can serve as a practical alternative when the access route is challenging. To the best of our knowledge, there are no detailed reports on the technical use of the Newton-shaped vascular catheter in the field of neurointervention. We present the usefulness of the specially shaped 8 Fr guide catheter.

BACKGROUND Iatrogenic pseudomeningocele incidence after lumbar surgery is 0.068%–2%, and most lumbar pseudomeningoceles are smaller than 5 cm; however, in rare cases, “giant” pseudomeningoceles greater than 8 cm in size may develop. Normal pressure hydrocephalus (NPH) is another rare condition in which the ventricles expand despite the presence of normal intracranial pressure. To date, pseudomeningocele associated with NPH has not been reported. OBSERVATIONS An 80-year-old woman underwent L3–5 laminectomy and posterior lumbar interbody fusion, and her symptoms improved after surgery. However, dementia appeared 1 month after surgery. Repeated brain computed tomography showed ventricular enlargement, and lumbar magnetic resonance imaging showed a long pseudomeningocele in the subcutaneous tissues at the L4 level. Here, the authors report a rare case of an iatrogenic giant pseudomeningocele accompanied by NPH after lumbar surgery. The symptoms of NPH in the present case occurred after spinal surgery and recovered after dural repair surgery, indicating that the changes in cerebrospinal fluid circulation and/or pressure due to pseudomeningoceles may cause NPH. LESSONS The prevention of dural tears through precise surgical technique and primary repair of dural tears are the best approaches to prevent pseudomeningocele incidence and subsequent events.

PURPOSE To evaluate the image quality of ultra-high-resolution CT (U-HRCT) in the comparison among four different reconstruction methods, focusing on the gastric wall structure, and to compare the conspicuity of a three-layered structure of the gastric wall between conventional HRCT (C-HRCT) and U-HRCT. METHOD Our retrospective study included 48 patients who underwent contrast-enhanced U-HRCT. Quantitative analyses were performed to compare image noise of U-HRCT between deep-learning reconstruction (DLR) and other three methods (filtered back projection: FBP, hybrid iterative reconstruction: Hybrid-IR, and Model-based iterative reconstruction: MBIR). The mean overall image quality scores were also compared between the DLR and other three methods. In addition, the mean conspicuity scores for the three-layered structure of the gastric wall at five regions were compared between C-HRCT and U-HRCT. RESULTS The mean noise of U-HRCT with DLR was significantly lower than that with the other three methods (P

Objective: Primary anterior cerebral artery (ACA) occlusion is a rare condition and sometimes leads to significant neurological deficits. We herein report on the efficacy of mechanical thrombectomy (MT) in treating the distal ACA occlusion in a clinical setting. Case Presentation: A 76-year-old woman presented with a sudden onset of right hemiparesis. Computed tomographic angiography and perfusion imaging and subsequent analysis with RAPID software revealed acute left ACA occlusion with salvageable penumbra. The patient obtained a score of 11 on the National Institutes of Health Stroke Scale. MT was performed for occlusion of the left ACA (A4), and successful reperfusion (Thrombolysis in Cerebral Infarction score of 3) was achieved on the first attempt using a stent retriever. The patient’s recovery progressed well, and she was discharged 13 days after admission with a modified Rankin Scale score of 1. Conclusion: This case report demonstrates the clinical efficacy, safety, and favorable clinical outcome of treating a primary distal ACA occlusion with MT.

Background Double origin of the posterior inferior cerebellar artery (DOPICA) is a rare cranial imaging finding with an incidence of 0.36–6% reported in various retrospective studies. Aneurysms on a DOPICA are even rarer. Case description A 34-year-old women hospitalised for subarachnoid haemorrhage showed a ruptured aneurysm arising from the caudal channel of the DOPICA. Endovascular treatment was selected, and the aneurysm was successfully and completely embolised using two coils. Conclusions To date, a total of three previous saccular aneurysms of the DOPICA itself have been reported, all of which were treated using endovascular methods. Our case is the first report of a ruptured saccular aneurysm arising from the non-branching segment of the caudal channel of the DOPICA.

Background True posterior inferior cerebellar artery (PICA) aneurysms outside the vertebral artery−PICA region are rare, with approximately 30 cases reported in just a few papers; no treatment paradigm has been advocated. The objective of this study was to present detailed clinical features and outcomes for several treatments for true PICA aneurysms and suggest an algorithm for treatment strategies. Methods We retrospectively analyzed outcomes of patients treated for PICA aneurysms with microsurgical and endovascular treatments. We also investigated the influence of several factors on the modified Rankin Scale score. Results Cases with PICA aneurysms (n = 36) outside the vertebral artery−PICA region were identified angiographically. Aneurysm locations included anterior medullary (n = 7), lateral medullary (n = 10), tonsillomedullary (n = 4), telovelotonsillar (n = 12), and cortical (n = 3) segments of the PICA. Aneurysm morphology was as follows: dissecting: 22; fusiform: 6; and saccular: 8. On multivariate analysis, age (P = 0.028) and lack of vermian infarction (P =0.037) were associated with a significantly better prognosis. Prognosis was not significantly different for the 5 aneurysm locations and among the 4 treatment groups: clipping/coiling, trapping/parent artery occlusion, trapping/parent artery occlusion + bypass, and observation including external ventricular drainage. Conclusions This study suggests that factors associated with significantly better prognosis include age, clip/coil treatments, and no vermian infarction complication. A treatment algorithm for true PICA aneurysms was supported according to pretreatment H and K grade, PICA segments, aneurysm morphology, and 3 types of ischemia linked to the brainstem, cerebellar hemisphere, or vermis.

Background: In pediatric patients with minor head trauma, computed tomography (CT) is often performed beyond the scope of recommendations that are based on existing algorithms. Herein, we evaluated pediatric patients with minor head trauma who underwent CT examinations, quantified its frequency, and determined how often traumatic findings were observed in the intracranial region or skull. Methods: We retrospectively reviewed the medical records and neuroimages of pediatric patients (0–5 years) who presented at our hospital with minor head trauma within 24 h after injury. Results: Of 2405 eligible patients, 1592 (66.2%) underwent CT examinations and 45 (1.9%) had traumatic intracranial hemorrhage or skull fracture on CT. No patient underwent surgery or intensive treatment. Multivariate analyses revealed that an age of 1–5 years (vs. P < 0.001), Glasgow Coma Scale (GCS) score of 14 (vs. a score of 15; P = 0.008), sustaining a high-altitude fall (P < 0.001), using an ambulance (P < 0.001), and vomiting (P < 0.001) were significantly associated with the performance of CT examination. In addition, traumatic abnormalities on CT were significantly associated with the combination of an age of under 1 year (P = 0.042), GCS score of 14 (P < 0.001), and sustaining a high-altitude fall (P = 0.004). Conclusion: Although slightly broader indications for CT use, compared to the previous algorithms, could detect and evaluate minor traumatic changes in pediatric patients with minor head trauma, over-indications for CT examinations to detect only approximately 2% of abnormalities should be avoided and the indications should be determined based on the patient’s age, condition, and cause of injury.

Background Whether the risk of rupture of a cerebral arteriovenous malformation (AVM) increases during pregnancy remains controversial. Moreover, it is unclear whether the number of pregnancies correlates with AVM rupture risk. We report a case of ruptured AVM during the fifth pregnancy. Case Description A 34-year-old woman presenting sudden headache and vomiting was admitted to our hospital. Neuroimaging revealed a subarachnoid hemorrhage due to a ruptured AVM in the right temporal lobe. She was pregnant (9 weeks and 1 day), and she had previously experienced 4 normal vaginal deliveries (gravidity and parity G4P4) without complications. Elective treatment including neuroendovascular and direct surgery was performed, and the AVM was safely resected (at 15 weeks, 6 days of pregnancy). She underwent elective caesarean section without complications 151 days after the AVM resection (at 37 weeks, 1 day of pregnancy), and the baby was healthy. Conclusions This report suggests that the risk of AVM rupture persists even after multiple deliveries. Intracranial hemorrhage should be suspected in pregnant patients who underwent multiple deliveries, and a rapid diagnosis and appropriate treatment are necessary.

A fine structure of blood flow through a curved vessel with an aneurysm was studied in in vitro experiments in relation to rheological factors of arterial diseases such as arteriosclerosis or thrombosis. On the basis of the in vivo data related to cerebral circulation, red blood cell suspension was flowed through curved vessel models with an asymmetrical aneurysm. Flow visualization was made with a microscope 16 mm cinecamera-TV monitor system, and the velocity profile was measured using the laser Doppler velocimeter. Vortices induced in aneurysm influenced flow structure and velocity at the presence of the secondary flow due to the vessel curvature. This suggests strongly that blood flow in curved arteries with an aneurysm must be understood under the influence of the secondary flow.

曲管内の拍動流における断面内速度分布をレーザ流速計を用いて測定し,その流速パターンが湾曲に沿ってどのように推移するかを実験的に調べた.速度分布は,湾曲および拍動の両者の影響を受け,特に最大流速が外側壁に移動した非対称な速度分布を示す時間位相と,ほぼ一様な速度分布を示す時間位相が存在することを明らかにした.管壁近傍の流速分布を基に,壁ずり速度を評価し,その場所的推移を調べた.