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N Moriyama

Publications and source records attributed to N Moriyama.

303 records · Page 17Linked to original sources
PubMedDate not supplied

Early invasive colorectal carcinomas with submucosal invasion: radiographic characteristics with barium double contrast images.

BACKGROUND: We assessed the radiographic characteristics of early colorectal carcinomas with submucosal invasion (CCSI) with the use of double-contrast images. METHODS: From 1989 to 1997, 193 patients with 196 CCSI lesions underwent double-contrast barium enema examinations. Three gastrointestinal radiologists retrospectively reviewed the radiographic characteristics of the lesions and classified them as protruding and depressed types by consensus. Further, subclassifying the protruding into lobular and smooth types was accomplished on the basis of surface structure. Each type was compared with pathologic findings of resected specimens. RESULTS: The incidence of the protruding type was 98.0%, and that of the depressed type was only 2.0%. The proportion of smooth lesions was 49.0% for the protruding type; these had a mean diameter of 17.9 mm, which was significantly smaller than the 23.1 mm mean observed for lobular lesions (p < 0.01). Of the smooth lesions, 44.7% demonstrated massive invasion, whereas 91.8% of lobular lesions exhibited only slight or moderate invasion into the submucosa (p < 0.01). The extent of invasion of the smooth lesions was greater than that for their lobular counterparts in terms of venous and lymph node involvement. CONCLUSION: Almost all CCSIs could be identified radiologically as protruding lesions; these had a smooth rather than a lobulated surface and demonstrated greater malignancy, despite the smaller size. It is clinically important to discriminate these from other polypoid lesions in establishing patient treatment. Double-contrast imaging is useful for evaluation of the surface characteristics of CCSIs in barium enema studies.

Adenocarcinoma↗
PubMedDate not supplied

Hepatic metastases of soft tissue angiosarcoma: CT and MR imaging findings.

BACKGROUND: We describe the computed tomographic (CT) and magnetic resonance imaging (MRI) findings of hepatic metastases caused by soft tissue angiosarcomas to clarify the relation between radiologic appearances and clinicopathologic features. METHODS: CT and MR examinations of 13 patients with hepatic metastases of soft tissue angiosarcoma were retrospectively analyzed. RESULTS: Contrast-enhanced CT images showed multiple hypoattenuating lesions relative to the adjacent liver parenchyma. Lesions contained peripheral areas of enhancement in eight patients (62%). Tumors showed cystic attenuation with fluid-fluid levels, which were suggestive of hemorrhage in five patients (38%). In one patient (8%) with cystic attenuation and fluid-fluid levels, lesions also contained marked enhanced nodular portions located centrally or peripherally. On T1-weighted MR images, all four liver tumors appeared heterogeneous and hypointense relative to adjacent liver parenchyma. Fluid-fluid levels were identified on T2-weighted MR images in five patients (38%). After an intravenous bolus of gadolinium-based contrast material was administered, slight peripheral enhancement was seen in three patients (75%). CONCLUSION: The common CT findings of metastatic angiosarcoma in our series were multiple hypoattenuating lesions often associated with nodular enhancement and cystic lesions with hemorrhagic change.

Adult↗
PubMedDate not supplied

Expression of vascular endothelial growth factor in hepatocellular carcinoma and the surrounding liver: correlation with MR imaging and angiographically assisted CT.

We summarize and discuss our previous research results on the correlation between findings on magnetic resonance (MR) imaging and angiographically assisted computed tomography (CT) and the intensity of vascular endothelial growth factor (VEGF) expression in hepatocellular carcinoma (HCC) and in the surrounding nontumorous liver. MR images (n = 22), CT during arterial portography (n = 20), and CT hepatic arteriography (n = 17) were retrospectively correlated quantitatively and qualitatively with VEGF expression in HCCs and in the surrounding liver assessed by western blotting. HCC-to-liver contrast-to-noise ratio correlated with VEGF expression index (VEGF(IND)) values of HCCs inversely on opposed-phase, T1-weighted, spoiled gradient recalled-echo (GRE) images, directly on T2-weighted, fast spin-echo images, and marginally and inversely on gadolinium-enhanced hepatic arterial-phase GRE images. On T2-weighted fast spin-echo images, standard deviation ratio of HCCs correlated directly with VEGF(IND) values of HCCs. By CT hepatic arteriography, the contrast-enhancement index of HCCs showed a moderate inverse correlation with VEGF(IND) values of HCCs, and the contrast-enhancement index of the liver showed marginal, moderate direct correlation with VEGF(IND) values in the liver. Heterogeneities of HCCs on images correlated directly with VEGF(IND) values of HCCs on opposed-phase T1-weighted GRE images, T2-weighted fast spin-echo images, hepatic arterial-phase GRE images, equilibrium-phase GRE images, and CT hepatic arteriogram. Our results may reflect that MR signal intensity, hepatic arterial vascularity, and heterogeneity of HCCs on CT or MR images are closely related to the intensity of VEGF expression in HCC as upregulated by hyper- or hypoxia in HCCs. Although the real effects of our results on radiologic practice are debatable at this moment, we believe that our results may help future radiologic practice in conjunction with biomolecular or genetic treatment for HCCs.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Retroperitoneal malignant mesenchymoma: imaging findings in five cases.

BACKGROUND: To describe computed tomographic (CT), magnetic resonance (MR), ultrasonographic (US), and angiographic findings of retroperitoneal malignant mesenchymoma with emphasis on CT findings. METHODS: Five CT, four US, four angiography, and two MR studies were obtained in five patients with pathologically proven retroperitoneal malignant mesenchymoma. RESULTS: Tumors were larger than 10 cm (n = 4), well-circumscribed and heterogeneous (n = 4), and with massive intratumorous calcifications (n = 3) on plain CT or US. Tumors showed heterogeneous enhancement on contrast-enhanced CT scans (n = 4) and moderate hypervascularity with heterogeneous staining on angiography (n = 3). Tumors were essentially hypointense on T1-weighted MR images (n = 2) and heterogeneous hyperintense on T2-weighted MR images (n = 2). Plain CT showed a fat-dense structure in a tumor in one patient. CONCLUSIONS: The radiologic findings of large expansile heterogeneous masses in the retroperitoneum, especially with massive calcifications, were considered to be typical of malignant mesenchymomas.

Aged↗
PubMedDate not supplied

Angiographic assessment of the right hepatic artery for encasement by hilar cholangiocarcinoma: comparison between antero-posterior and right anterior oblique projections.

PURPOSE: To evaluate the usefulness of right anterior oblique (RAO) arteriography for evaluating encasement of the right hepatic artery (RHA) by hilar cholangiocarcinoma. METHODS: Celiac arteriography was performed in both the antero-posterior (AP) and RAO projection in ten patients with cholangiocarcinoma. The lengths of the arteries between the bifurcation of the anterior and posterior branch of the liver and the following points were measured: (a) the bifurcation of the left and right hepatic artery (AP-LR), (b) the bifurcation of the proper hepatic artery and the gastroduodenal artery (AP-PG). Additionally, image quality in investigating the invasion of the RHA was evaluated. RESULTS: On the AP images, the average lengths of AP-LR and AP-PG were 24.5 +/- 5.1 mm and 30.0 +/- 4.9 mm, respectively. On RAO images, the lengths were 28.2 +/- 4.6 mm and 32.7 +/- 4.8 mm, respectively. Every length was different between the two projections (p < 0.01). In 6 of 10 patients with hilar cholangiocarcinoma, images in RAO projections were superior to AP images for evaluation of encasement. CONCLUSION: We conclude that angiography obtained in the RAO projection yields images that are superior to those obtained in the conventional AP projection for assessment of RHA encasement.

Adult↗
PubMedDate not supplied

Computed tomography of sclerosing hepatocellular carcinoma.

We reviewed computed tomography (CT) in eight patients with sclerosing hepatocellular carcinoma who underwent resection. Dynamic CT was performed 25-40 s (rapid phase) and 5-10 min (late phase) after injection of contrast medium. Most of the lesions were round and homogeneous. Tumors tended to show density equal to the liver. The relative density of the tumors in the rapid phase, however, tended to be higher than in other phases. A peripheral low-density area was absent. Dynamic CT was thus important in the diagnosis of sclerosing hepatocellular carcinoma.

Adult↗
PubMedDate not supplied

Computer-aided diagnosis for pulmonary nodules based on helical CT images.

In this paper, we present a computer-assisted automatic diagnostic system for lung cancer that detects nodule candidates at an early stage from helical CT images of the thorax. Our diagnostic system consists of analytical and diagnostic procedures. In the analytical procedure, first we extract the lung and the pulmonary blood vessel regions using the fuzzy clustering algorithm, then we analyze the features of these regions using image-processing techniques. In the diagnostic procedure, we define diagnostic rules utilizing the extracted features which support the determination of the candidate nodule locations. We show the effectiveness of our system by giving the results from its application to image data for mass screening of 450 patients.

Algorithms↗
PubMedDate not supplied

Findings in primary hepatic carcinoid tumor: US, CT, MRI, and angiography.

Two asymptomatic patients with surgically proven solitary primary hepatic carcinoid tumors are reported. Ultrasonography showed hyperechoic masses containing multiple small cystic areas in both cases. On unenhanced CT, one tumor was of low density and one was isodense with multiple low density foci. One tumor showed marked retention of contrast medium on post-angiographic CT. Magnetic resonance imaging revealed low intensity masses on T1-weighted images and high intensity tumors with multiple areas of higher intensity on T2-weighted imaging. The small low density areas in these masses corresponded histopathologically to multiple vascular lakes. Late enhancement of the mass was presumed to correspond with proliferative fibrous tissue within the mass.

Adult↗
PubMedDate not supplied

Focal nodular hyperplasia of the liver: arterial angio-CT and microangiography.

To differentiate focal nodular hyperplasia (FNH) from other hepatic tumors, especially hepatocellular carcinoma, we evaluated the hemodynamics of histologically proved FNH in three patients, two by arterial angio-CT and one by microangiography of the resected specimen. These studies demonstrated the centrifugal blood supply of FNH (early filling of central tumor vessels radiating to periphery, and lobulated tumor stains with central low density area in the late phase), which could not be demonstrated by dynamic CT or hepatic angiography. Arterial angio-CT is useful as a further study, when differential diagnosis of FNH is uncertain by other imaging techniques.

Adolescent↗
PubMedDate not supplied

Growing cavernous haemangioma of the liver: 11-fold increase in volume in a decade.

A 57 year old Japanese male was incidentally found to have a 7.5 cm diameter hepatic haemangioma. Eleven years later he was operated on because the haemangioma had grown into a 17 cm mass causing upper abdominal fullness. Volumetry on computerized tomograms disclosed that the haemangioma had grown from 123 cm3 to 1343 cm3 in volume. Quantitative documentation on growing hepatic haemangioma has been rare.

Hemangioma, Cavernous↗
PubMedDate not supplied

Hilar cholangiocarcinoma evaluated by three-dimensional CT cholangiography and rotating cine cholangiography.

BACKGROUND/AIMS: To evaluate the usefulness of three-dimensional cholangiography and rotating cine cholangiography in depicting the anatomy of the hilar bile duct and tumor extension, and in planning surgical procedures for hilar cholangiocarcinomas. METHODOLOGY: Five patients with hilar cholangiocarcinoma and obstructive jaundice who underwent percutaneous transhepatic biliary drainage followed by resection were serially examined by cine cholangiography and three-dimensional cholangiography which were reconstructed from a helical computed tomography scan. Tumor extension to the bile ducts was prospectively diagnosed and the resection margin was planned using both cine and three-dimensional cholangiograms. The histological evaluation of the resected specimens were compared with preoperative findings of cholangiograms. RESULTS: The three-dimensional cholangiograms from vertical projection demonstrated the bile duct anatomy with excellent image quality. To assess tumor invasion to the intrahepatic bile ducts, cine cholangiograms from lateral and oblique projections were necessary. Selection of the surgical procedure was influenced by preoperative evaluations of the lesion on both three-dimensional and cine cholangiograms. Histologically, the resected margin was free from tumor in all cases. CONCLUSIONS: Three-dimensional and cine cholangiography allowed accurate assessment of the biliary system in patients with hilar cholangiocarcinoma, which was helpful for planning the surgical procedure.

Aged↗
PubMedDate not supplied

Intraoperative and conformal external-beam radiation therapy in patients with locally advanced pancreatic carcinoma; results from a feasibility phase II study.

BACKGROUND/AIMS: Chemoradiation therapy is widely indicated to patients with locally advanced pancreatic carcinoma, though the capability of radiotherapy alone is not assessed enough. The purpose of this study is to clarify the efficacy and safety of a more intensive radiotherapy for those patients. METHODOLOGY: Fifteen patients were enrolled in a feasible phase II study of treatment with intraoperative radiation therapy (25 Gy), followed by conformal external-beam radiation therapy (40 Gy in 20 fractions, 5 times/week). The antitumor effect was evaluated on the early phase of dynamic computed tomography image. RESULTS: The full irradiation dose was feasible in 12 of 15 patients. The overall response rate was 40% (1 complete and 5 partial responses). Grade 3 toxicity was observed in 2 patients (13%) with nausea/vomiting or anorexia. One patient developed gastric ulcer and died of gastrointestinal bleeding 12 months after intraoperative radiation therapy. The median survival time was 11.1 months, and the 2-year survival rates were 13%. Survival for more than 2 years was observed in 2 of the 6 responders. CONCLUSIONS: The above radiotherapy is considered to be active for the locally advanced pancreatic cancer with acceptable toxicity, when the gastrointestinal tract is excluded from the radiation field. This should be further assessed in late phase II studies involving a large number of patients.

Adenocarcinoma↗
PubMedDate not supplied

Radiographic features of invasive lobular carcinoma of the breast.

PURPOSE: To evaluate the radiographic features of invasive lobular carcinoma of the breast. METHODS: We evaluated the radiographic features of 61 cases of histopathologically documented invasive lobular carcinoma. Mammography was performed in all cases. In seven of 61 cases, helical CT with contrast medium was also carried out. Mammographic findings were analyzed to determine true-positive and false-negative rates for the detection of neoplasm. Further, the diameter of the tumor as determined on mammography and helical CT was noted for comparison with the pathologic size. RESULTS: Mammographic features were divided into six types: spiculated mass (38%), indistinct mass (5%), obscured mass (23%), asymmetric opacity (16%), architectural distortion (16%), and no findings (2%). Microcalcifications were present in 12 cases (20%). The overall sensitivity rate was 59%. However, 20 (56%) of 36 cases that were diagnosed as detectable on mammography were underestimated in terms of tumor size compared with the histopathologic findings. Four cases examined by helical CT with contrast medium were compared with the histopathologic findings in terms of extent of the lesion. In three cases, helical CT was more precise than mammography, but the histopathologic findings showed lesions beyond the region evaluated by helical CT. CONCLUSION: Invasive lobular carcinoma is difficult to detect radiographically, and the extent of the lesion tends to be underestimated.

Adult↗
PubMedDate not supplied

Cine MRI in radiotherapy treatment planning of brain tumors.

This paper presents our preliminary experience with three-dimensional (3-D) treatment planning using the cine mode display of magnetic resonance imaging (MRI) for brain tumors. MRI images, viewed from the direction of the source of radiation, are reconstructed at consecutive 5 mm intervals and superimposed on the 3-D skin surface image. Tumors and normal structures can be visualized as is, without delineating them. Limitations of the technique are also discussed.

Adult↗