Biomedical subjects
Publications and source records attributed to I Sakamoto.
We describe a patient with Behçet's disease who developed multiple aneurysms and retroperitoneal hemorrhage due to rupture of a renal artery aneurysm. Despite successful transcatheter arterial embolization, the patient died due to pneumonia. Our retrospective review of the case revealed that the CT scan obtained 3 months before the rupture had demonstrated dilatation of bilateral renal arteries.
We describe computed tomographic (CT) findings at the early stage of infected abdominal aortic aneurysm in three patients. Periaortic mass and increased fat density were the characteristic findings of early aortic infection on CT. Similar findings caused by other diseases may be difficult to differentiate by imaging alone, but these findings should be used to trigger close follow-up for patients with suspected infected abdominal aortic aneurysm.
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We report a patient with focal renal vein thrombosis that presented as a hyperdense mass mimicking a hyperdense cyst or a pelvic or parenchymal tumor. The lesion was described as a well-defined round hyperdense mass in the right renal sinus on noncontrast CT and was surgically proven to be acute thrombosis of the renal vein. Renal vein thrombosis should be considered in the differential diagnosis of a hyperdense mass in the renal sinus even if the patient has no underlying renal abnormality.
A case of twisted ovarian tumor with intravascular gas is presented, and the mechanism of the gas formation is discussed. On the basis of the probable mechanism of gas formation observed in dead fetuses, the gas seen in the present case is considered to have been oxygen released from trapped oxyhemoglobin within the tumor vessels. "Intravascular gas" within an ovarian tumor, although extremely rare, is diagnostic of ovarian torsion.
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.
PURPOSE: Our purpose was to analyze the CT findings of neural plexus invasion in common bile duct carcinoma. METHOD: We studied 16 patients with common bile duct carcinoma who underwent surgery. Of these, neural invasion was seen in 10 patients. CT findings were retrospectively reviewed and correlated with the surgical and pathological findings. RESULTS: Irregular masses adjacent to the medial aspect of the uncinate process were observed in 4 of 14 patients with distal common bile duct carcinoma. These lesions extended medially and showed contiguity with the superior mesenteric artery and/or celiac axis, corresponding to neural plexus invasion with desmoplastic change. Increased attenuation of the fat between the common bile duct and the proper hepatic artery was seen in two of two patients with proximal common bile duct carcinoma, associated with neural plexus invasion in the hepatoduodenal ligament. CONCLUSION: The location and spread of neural plexus invasion in common bile duct carcinoma are characteristic and can be diagnosed by CT.
We present four cases of common bile duct carcinoma in which both angiographic helical CT (angio-HCT) and pancreatoduodenectomy were done in the 3 years since 1995. Angio-HCT was performed with direct infusion of the contrast medium through the gastroduodenal artery inserted on angiography. Angio-HCT displayed the tumors as lower density areas in contrast to the strong enhancement of the circumferential nontumorous areas, including the pancreas and duodenum.
PURPOSE: The purpose of this study was to describe the characteristic findings in each imaging modality of anomalous systemic arterial supply to normal basal segments of the left lower lobe of the lung. METHOD: Five patients with anomalous systemic arterial supply to normal basal segments of the left lower lobe were retrospectively reviewed. Chest radiography, contrast-enhanced CT scan, angiography, and other imaging modalities were analyzed. RESULTS: The imaging findings of this anomaly were characterized by three issues as follows: an anomalous systemic artery arising from the thoracic aorta, absence of pulmonary arterial supply, and normal bronchial system as well as normal pulmonary parenchyma in the affected segments. The anomalous systemic artery was demonstrated on chest radiography, contrast-enhanced CT scan, MRI, and thoracic aortography. Absence of pulmonary arterial supply was revealed by pulmonary angiography, radiolabeled perfusion scan, and CT scan. Normal bronchial system was confirmed by radiolabeled ventilation scan, bronchography, and CT scan. CONCLUSION: CT is useful in making the correct diagnosis of this anomaly because it is the only diagnostic method that can demonstrate the anomalous systemic artery, absence of pulmonary arterial supply, and normal bronchial system in the affected segments.
Diagnosis of Takayasu arteritis is difficult because the clinical features are similar to those of other diseases. In early-phase Takayasu arteritis, computed tomography (CT) and magnetic resonance (MR) imaging show thickening of the aortic wall. Late-phase Takayasu arteritis has been classified into four types: classic pulseless disease (type I), a mixed type (type II), the atypical coarctation type (type III), and the dilated type (type IV). In late-phase Takayasu arteritis, angiography usually demonstrates luminal changes such as stenosis, occlusion, or aneurysmal dilatation of the aorta and pulmonary artery and their branches. However, absence of such luminal changes does not exclude the possibility of early-phase Takayasu arteritis. Improvement in the clinical findings and subsidence of the active inflammatory process can be expected with early steroid treatment. Familiarity with the varied chest radiographic, angiographic, CT, and MR imaging features of Takayasu arteritis will permit earlier diagnosis and treatment.
Transcatheter arterial embolization (TAE) is widely used in the treatment of hepatic tumors. A total of 2,300 TAE procedures were performed with a 2-15-mL injection of a mixture or suspension of anticancer drugs and iodized oil, followed by administration of gelatin sponge particles. One or two chemotherapeutic drugs, including doxorubicin hydrochloride (10-30 mg), epirubicin hydrochloride (10-30 mg), mitomycin C (10-20 mg), and cisplatin (25-100 mg), were used for each procedure. Complications were encountered in 4.4% of cases (n = 102) and were related to the use of chemoembolic agents or the manipulation of a catheter or guide wire. These complications included acute hepatic failure (n = 6), liver infarction (n = 4) or abscess (n = 5), intrahepatic biloma (n = 20), multiple intrahepatic aneurysms (n = 6), cholecystitis (n = 7), splenic infarction (n = 2), gastrointestinal mucosal lesions (n = 5), pulmonary embolism or infarction (n = 4), tumor rupture (n = 1), variceal bleeding (n = 3), and iatrogenic dissection (n = 35) or perforation (n = 4) of the celiac artery and its branches. Knowledge of these complications is important for correct diagnosis and appropriate management.
Penetrating atherosclerotic ulcer is an ulcerating atherosclerotic lesion that penetrates the elastic lamina and is associated with hematoma formation within the media of the aortic wall. This pathologic condition is distinct from classic aortic dissection and aortic rupture; however, care should be taken in making the diagnosis, particularly if the disease is discovered incidentally. At computed tomography (CT), penetrating atherosclerotic ulcer manifests as focal involvement with adjacent subintimal hematoma and is often associated with aortic wall thickening or enhancement. Magnetic resonance imaging is superior to conventional CT in differentiating acute intramural hematoma from atherosclerotic plaque and chronic intraluminal thrombus and allows unenhanced multiplanar imaging. Spiral CT involves shorter examination times and allows high-quality two- and three-dimensional image reconstruction. CT angiography can demonstrate complex spatial relationships, mural abnormalities, and extraluminal pathologic conditions. Transesophageal echocardiography has been reported to be highly sensitive and specific in the differentiation of aortic disease, and intravascular ultrasonography may also be useful in this setting. Although rupture or other life-threatening complications are rare, patients with penetrating atherosclerotic ulcer must be followed up, particularly during the 1st month after onset. Surgical treatment may become necessary in cases involving evidence of intramural hematoma expansion, signs of impending rupture, inability to control pain, or blood pressure changes.
BACKGROUND: We investigated whether oral levofloxacin was as effective as intravenous cefazolin sodium for preventing postoperative infections in patients undergoing sagittal split ramus osteotomy of the mandible. METHODS: Forty-four patients were randomized to treatment with levofloxacin or cefazolin sodium. Levofloxacin (100 mg t.d.s.) was administered orally, and cefazolin sodium (1 g b.i.d.) by intravenous infusion. Both drugs were given until 5 days postoperatively. The concentrations of levofloxacin in the mandibular bone marrow and serum were measured. RESULTS: The mean levofloxacin concentration 4 h and 53.7 min after administration was 1.086 microg/ml in serum and 1.328 microg/ml in the mandibular bone marrow. The efficacy rate of levofloxacin was 95% and that of cefazolin sodium was 85.7%, with no significant difference between the two drugs (p = 0.322). CONCLUSION: Oral administration of levofloxacin is a simple, cost-effective and safe alternative to intravenous antibiotic prophylaxis after mandibular surgery.
We present a case of pancreatic pseudoaneurysm converted from a pseudocyst. Contrast-enhanced CT disclosed a round enhancing lesion at the previously identified pseudocyst, and angiography confirmed the diagnosis of a pseudoaneurysm. The pseudoaneurysm was successfully treated by arterial embolization. We believe arterial embolization to be the treatment of choice for pseudoaneurysm as a complication of pancreatitis.
The authors used a fibrin clot (FC) as a carrier of an anti-cancer drug (AD) to achieve sustained release of the drug. Adriamycin (ADM) and cis-platinum (CDDP) were individually encapsulated into an FC, and the profile of release of each AD from the FC-AD was examined in vitro. The FC-AD was placed intra-abdominally in ascites hepatoma AH130-bearing rats, and ADM or CDDP solution was intraperitoneally injected (IP) into other cancer bearing rats. The survival time was recorded, and related oncolytic mechanisms were investigated. The release of AD from the FC continued for over 15 days. Sixty-eight percent of the rats treated with FC-AD survived for more than 200 days and evidence of malignancy disappeared. Almost all of the IP rats and non-treated rats died within 20 days; these animals had massive ascites and extensive metastases. Immunologic studies confirmed that various tumor immunoresponses were induced in the rats treated with FC-AD. The FC-AD system warrants further study for possible antineoplastic activities in vivo.