Longitudinal changes in renal volumes evaluated by automated three-dimensional volumetric computed tomography of the whole kidney: The association with the renal function and disease progression.

PURPOSE: To clarify the changes in the total renal volume over time with changes of the renal function using automated 3D volumetric CT of the whole kidney and to evaluate the usefulness of the total renal volume CT measurement in predicting chronic kidney disease (CKD) grade progression. METHODS: A total of 961 patients who underwent abdominal CT at least twice (an interval of more than 4 years) were included. The automated 3D volumetric CT measurement of the whole kidney was performed at the initial and latest CT examination. Patients with CKD grade G2 at the time of the initial CT were divided into two groups: a progression group (CKD grade progressed to G3-G5) and a non-progression group. Changes in the renal volume over time were compared between the two groups. RESULTS: The volume of both kidneys measured on initial CT was positively correlated with eGFR (ρ = 0.490, p < 0.001). There was a significant difference in the initial volume of both kidneys among CKD grades (p < 0.001, G1:318.7 ± 60.5 ml, G2:275.5 ± 53.5 ml, G3:233.7 ± 46.9 ml, G4:183.2 ± 22.5 ml, G5:157.7 ± 77.4 ml). When comparing the progression and non-progression groups, the initial volume of both kidneys was significantly smaller in the progression group, compared with the non-progression group (252.0 ± 50.6 ml vs. 278.9 ± 53.7 ml). In addition, the annual reduction volume in both the right and left kidneys was significantly greater in the progression group than in the non-progression group (p < 0.001). CONCLUSION: The automated 3D volumetric CT measurement of the whole kidney has the potential to monitor changes in renal volume over time with changes of the renal function.

Ultra-high resolution computed tomography with deep-learning-reconstruction: diagnostic ability in the assessment of gastric cancer and the depth of invasion.

PURPOSE: To evaluate the image quality of ultra-high-resolution CT (U-HRCT) images reconstructed using an improved deep-learning-reconstruction (DLR) method. Additionally, we assessed the utility of U-HRCT in visualizing gastric wall structure, detecting gastric cancer, and determining the depth of invasion. METHODS: Forty-six patients with resected gastric cancer who underwent preoperative contrast-enhanced U-HRCT were included. The image quality of U-HRCT reconstructed using three different methods (standard DLR [AiCE], improved DLR-AiCE-Body Sharp [improved AiCE-BS], and hybrid-IR [AIDR3D]) was compared. Visualization of the gastric wall's three-layered structure in four regions and the visibility of gastric cancers were compared between U-HRCT and conventional HRCT (C-HRCT). The diagnostic ability of U-HRCT with the improved AiCE-BS for determining the depth of invasion of gastric cancers was assessed using postoperative pathology specimens. RESULTS: The mean noise level of U-HRCT with the improved AiCE-BS was significantly lower than that of the other two methods (p < 0.001). The overall image quality scores of the improved AiCE-BS images were significantly higher (p < 0.001). U-HRCT demonstrated significantly better conspicuity scores for the three-layered structure of the gastric wall than C-HRCT in all regions (p < 0.001). In addition, U-HRCT was found to have superior visibility of gastric cancer in comparison to C-HRCT (p < 0.001). The correct diagnostic rates for determining the depth of invasion of gastric cancer using C-HRCT and U-HRCT were 80%. CONCLUSIONS: U-HRCT reconstructed with the improved AiCE-BS provides clearer visualization of the three-layered gastric wall structure than other reconstruction methods. It is also valuable for detecting gastric cancer and assessing the depth of invasion.

Automated whole-volume measurement of CT fat fraction of the pancreas: correlation with Dixon MR imaging.

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.

Lobar hepatic steatosis: Association with portal flow hemodynamics evaluated by multiphasic dynamic contrast-enhanced CT.

PURPOSE: This study aimed to evaluate the association of portal flow hemodynamics with lobar hepatic steatosis by means of dynamic contrast-enhanced (DCE) CT. METHODS: The study population consisted of 235 patients, 77 with lobar hepatic steatosis (right, n = 67; left, n = 10), 158 with diffuse hepatic steatosis with (n = 76) and without (n = 82) a focal fatty spared area. CT attenuation values (Hounsfield units: HU) of the liver with and without hepatic steatosis were measured in unenhanced and arterial-phase CT. The contrast enhancement (CE) values were calculated as the difference in HU values between unenhanced and arterial-phase CT. RESULTS: In 67 patients with lobar steatosis of the right lobe, the median CE values of the areas of right lobar steatosis were significantly lower than those of the non-fatty left lobe (13 [IQR 7-19] vs 23 [13-33] HU, P < 0.01), suggesting dominant SMV flow to the right lobe with lobar hepatic steatosis. Conversely, in 10 patients with lobar steatosis of the left lobe, the median CE values of the areas of left lobar steatosis were lower than those of the non-fatty right lobe (15.5 [11.75-21.5] vs 16 [14.5-22] HU); however, this difference was not statistically significant (P = 0.20). In 76 patients with a focal fatty spared area, there were significant differences in the median CE values between hepatic steatosis areas and focal fatty spared areas in the gallbladder fossa group (P = 0.01) and in the segment IV group (P < 0.01). CONCLUSION: Lobar hepatic steatosis may be associated with regional changes of the portal flow hemodynamics (i.e., predominant perfusion from the SMV flow to the lobes with steatosis).

Dual-Source Contrast-Enhanced Multiphasic CT of the Liver Using Low Voltage (70 kVp): Feasibility of a Reduced Radiation Dose and a 50% of Contrast Dose.

This study investigated the feasibility of both a reduced radiation dose and a 50% of contrast dose in multiphasic CT of the liver with a 70 kVp protocol compared with a standard-tube-voltage protocol derived from dual-energy (DE) CT (blended DE protocol) with a full-dose contrast-agents in the same patient group. This study included 46 patients who underwent multiphasic contrast-enhanced dynamic CT of the liver with both a 70 kVp and a blended DE protocols. For quantitative analysis, median CT values for the liver, aorta, and portal vein, as well as signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), were measured and calculated. In addition, as a qualitative analysis, the contrast effect and overall image quality of the abdominal organs were evaluated on a five-point scale. CNR and SNR of the hepatic parenchyma were not significantly different between the 70kV protocol and the Blended DE protocol in all phases. The 70 kVp protocol showed significantly better image quality compared with the blended DE protocol in the arterial phase (p = 0.035) and the equilibrium layer phase (p = 0.016). A 70 kVp CT protocol in combination with a reduced radiation dose and half-dose iodine load is feasible for multiphasic dynamic CT of the liver by maintaining the contrast enhancement effects and image quality in comparison with the blended DE CT protocol.

Assessment of gastric wall structure using ultra-high-resolution computed tomography.

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 < 0.001). The mean overall image quality scores with DLR images were significantly higher than those with the other three methods (P < 0.001). Regarding the comparison between C-HRCT and U-HRCT, the mean conspicuity scores for the three-layered structure of the gastric wall on U-HRCT were significantly better than those on C-HRCT in the fornix (5 [5-5] vs. 3.5 [3-4], P < 0.001), body (4 [3.25-5] vs. 4 [3-4], P = 0.039), angle (5 [4-5] vs. 3 [2-4], P < 0.001), and antral posterior (4 [3.25-5] vs. 2 [2-4], P < 0.001), except for antral anterior (4 [3-5] vs. 3 [3-4], P = 0.230) CONCLUSION: U-HRCT using DLR improved the image noise and overall image quality of the gastric wall as well as the conspicuity of the three-layered structure, suggesting its utility for the evaluation of the anatomical details of the gastric wall structure.

Clinical Experience of Using an 8 French Newton Shaped Catheter (Neuro-EBU) During Endovascular Treatment: A Case Series of 21 Patients.

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.

Normal pressure hydrocephalus due to an iatrogenic giant lumbar pseudomeningocele after posterior lumbar interbody fusion: illustrative case.

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.

Indications for computed tomography use and frequency of traumatic abnormalities based on real-world data of 2405 pediatric patients with minor head trauma.

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. <1 year; 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.

Multidisciplinary Treatments of True Posterior Inferior Cerebellar Artery Aneurysms: Single-Center Retrospective Study and Treatment Algorithm.

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.

Coiling for a saccular aneurysm on the caudal channel in double origin of the posterior inferior cerebellar artery.

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.

Coiling for an unruptured saccular aneurysm at the non-branching segment of the distal anterior cerebral artery: Case report and literature review.

BACKGROUND: Saccular aneurysms in the non-branching segment of the distal anterior cerebral artery (DACA) are extremely rare. Here, we describe the first case of coil embolization using a simple, non-adjunctive technique for an aneurysm at this rare location. CASE DESCRIPTION: A 74-year-old man with an asymptomatic, unruptured aneurysm of the right DACA was followed up annually for 3 years by medical checkup. Endovascular treatment was proposed because of a slight angiographic change in the shape of the aneurysm in the past year. The aneurysm at the non-branching site of the right calloso-marginal artery was 2 mm distal to the origin, and measured 3 mm in height and 3.3 mm in width, with a neck measuring 1.7 mm wide; the calloso-marginal artery diameter was 1.6 mm. The aneurysm was successfully embolized with a simple technique using a Pre-Shaped S Microcatheter and two coils. CONCLUSIONS: The simple, non-adjunctive technique for coil embolization of saccular side-wall type aneurysm in the non-branching segment of the DACA could be performed using the appropriate catheter and a softer coil.

Ruptured Cerebral Arteriovenous Malformation During Fifth Pregnancy: Case Report and Literature Review.

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.

Mechanical Thrombectomy of Primary Distal Anterior Cerebral Artery Occlusion: A Case Report.

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.