Yohjiro Matsuoka

Fate of intramural hematoma of the aorta : CT evaluation

PURPOSE Our goal was to investigate the fate of intramural hematoma of the aorta. METHOD In 32 patients with intramural hematoma of the aorta, we reviewed CT (n = 32) and MR (n = 22) findings. The diagnosis was established by CT, and regular follow-up studies were performed. RESULTS All intramural hematomas decreased in size. Ulcer-like projections (ULPs) were identified at the initial study in 6 patients and during the follow-up period in 14 patients. The ULPs progressed to saccular aneurysm in 12 patients (mean 47.0 days), while fusiform aneurysm developed in 6 patients (mean 347.7 days) without ULP. In two patients, the affected aorta progressed to overt aortic dissection. CONCLUSION Intramural hematoma itself usually decreases in size. However, the affected aorta can progress to aneurysm or overt aortic dissection. Development of saccular aneurysm from ULPs can be considered an early complication. In cases without ULP, fusiform aneurysm may develop as a late complication. All intramural hematomas need to be followed since it seems to be difficult to predict the exact fate of intramural hematoma from the initial imaging findings.

Fatal Paradoxical Air Embolism Diagnosed by Postmortem Imaging and Autopsy

Abstract:  The recognition and visualization of an arterial gas embolism are difficult. We report a case of sudden death caused by paradoxical air embolism of coronary and cerebral arteries, diagnosed by the pre autopsy computed tomography (CT) scanning. A 54‐year‐old woman suddenly died after the self‐removal of the jugular vein catheter. Postmortem imaging examination using CT scanning showed multiple gas embolisms in the cerebral arteries, pulmonary artery, right atrium and ventricle, left ventricle, aorta, and coronary arteries. These findings suggested that the occurrence of acute ischemia of the brain and heart caused by massive air inflow to the artery. Conventional autopsy revealed a patent foramen ovale of the heart. These results indicated that the patient died of paradoxical air embolization of the coronary and cerebral arteries through a patent foramen ovale because of right‐to‐left shunting. The use of postmortem imaging as an aid for conventional autopsy has proved to be of advantage in the case of gas embolism.

Two cases of hepatopulmonary syndrome with improved liver function following long-term oxygen therapy

Hepatopulmonary syndrome (HPS) is a complication of liver disease that is characterized by hypoxemia and intrapulmonary vascular dilatations. The only established therapy for this disorder is liver transplantation. Here, we report two patients (a 63-year-old woman and a 72-year-old man) with HPS associated with hepatitis C virus-related cirrhosis. We gave the patients low-dose oxygen supplementation to improve their respiratory symptoms. Surprisingly, their liver function improved from Child Pugh class C to class A, and ascites disappeared after a year of oxygen supplementation. We believe that long-term oxygen therapy contributed to the improvement of liver function in these two cases. Long-term oxygen therapy might offer a new therapeutic approach to improve liver function in patients with cirrhosis with hypoxemia.

Local Recurrence After Chemoembolization of Hepatocellular Carcinoma: Uptake of Gadoxetic Acid as a New Prognostic Factor

OBJECTIVE The purpose of this article is to investigate whether there is a difference in susceptibility to transcatheter arterial chemoembolization between hepatocellular carcinomas (HCCs) showing high uptake and those showing low uptake of gadoxetic acid in the hepatobiliary phase of MRI. MATERIALS AND METHODS One hundred HCCs that achieved optimal chemoembolization, as assessed by immediate CT in 60 patients, were classified as having high (n = 19) or low (n = 81) uptake of gadoxetic acid on MRI performed before chemoembolization. The local recurrence rates were estimated using the Kaplan-Meier method, and differences between the groups were compared using the log-rank test. The following factors were also correlated with the local recurrence rate using the Cox proportional hazards model for a univariate analysis: high uptake of gadoxetic acid, number of feeding arteries, extrahepatic arterial supply, Child-Pugh class, clinical tumor stage, size, location, and iodized oil accumulation in the noncancerous tissue surrounding the lesion. Parameters that were significant at p < 0.05 were entered into a multivariate model. RESULTS The 1- and 3-year local recurrence-free rates were 95% in high-uptake HCCs and 66% and 54%, respectively, in low-uptake HCCs (log-rank test, p < 0.01). The low uptake of gadoxetic acid was the only significant predictor of early local recurrence (hazard ratio = 9.24; p = 0.03) by multivariate analysis. CONCLUSION HCCs showing high uptake of gadoxetic acid appear to be susceptible to chemoembolization.

Therapeutic ethanol injection of hepatocellular carcinomas undetectable by angiography and lipiodol computed tomography

Seven smaller than 2 cm in diameter hepatocellular carcinomas (HCC) undetectable by hepatic arteriography and computed tomography (CT) after intraarterial injection of iodized oil (Lipiodol CT) were diagnosed by ultrasonography-guided fine-needle biopsy in 6 patients. All lesions were treated by percutaneous ethanol injection (PEI) in 1–3 weekly intervals. No recurrences have been demonstrated after 7–15 months. The treatment of HCCs undetectable by angiography and Lipiodol CT presents a problem as transcatheter arterial embolization is considered ineffective due to, poor vascularity. PEI appears to be an excellent treatment for these small HCCs.

Primary Pericardial Malignant Fibrous Histiocytoma Causing Cardiac Tamponade

We describe herein an extremely rare case of a large primary pericardial malignant fibrous histiocytoma causing a cardiac tamponade that occurred in a 72-year-old woman. The clinical, radiographic, and pathologic features are reported here together with a brief review of the literature.

Contrast-fluid level in the inferior vena cava (IVC niveau sign) in patients with acute type A aortic dissection: computed tomography findings during acute cardiac tamponade

PurposeThe purpose of this study was to report a new computed tomography (CT) finding in acute cardiac tamponade: a contrast-fluid level in the hepatic inferior vena cava (IVC) during an arterial dominant phase CT study (IVC niveau sign) in patients with acute type A aortic dissection.Materials and methodsWe retrospectively reviewed CT studies with the diagnosis of proximal aortic dissection (Stanford type A) with acute cardiac tamponade. There were 12 patients enrolled in the study (6 women, 6 men; mean age 66 years). A total of 62 patients were selected as a control chronic pericardial effusion group to compare with the acute cardiac tamponade group.ResultsAmong the 12 patients with acute cardiac tamponade, the IVC niveau sign was seen in 7 (58%). In the control chronic pericardial effusion group (n = 62), we identified the IVC niveau sign in only one patient (1.6%). There was a significant difference in the presence of the IVC niveau sign between the acute cardiac tamponade and chronic pericardial effusion groups (P < 0.0001).ConclusionThe presence of the IVC niveau sign suggests acute cardiac tamponade in patients with acute type A aortic dissection.

Coronary artery-cardiac chamber shunt: cineangiographic analysis

Coronary artery-cardiac chamber shunts (CA-CC shunts) were observed in 101 out of 2267 consecutive patients (4.5%) receiving selective coronary angiography. In these patients, contrast medium injected into the coronary artery escaped directly into the cardiac chamber. CA-CC shunts were angiographically classified into the following two types. Type I: The endocardial layer was diffusely opacified, and contrast medium escaped into the cardiac chamber on systole (n=83). Type II: Contrast medium escaped directly into the cardiac chamber via an undilated branch (n=11). Type I and type II shunts were observed simultaneously in 7 patients. It is speculated that type I is a shunt via a persistent arterio-sinusoidal vessel, while type II is a shunt via a persistent arterio-luminal vessel. Both types were observed frequently (24.9%) in hypertrophic cardiomyopathy. The degree of CA-CC shunts in hypertrophic cardiomyopathy was not influenced by the presence or absence of myocardial squeezing. CA-CC shunts are considered to be due to an abnormality in the coronary microcirculation of the myocardium. We describe the angiographic features of the two types of CA-CC shunt and discuss their pathophysiological significance.