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Biomedical subjects

M Iio

Publications and source records attributed to M Iio.

At least 199 records · Page 11Linked to original sources
PubMed1983

Computed tomography of primary intrahepatic biliary malignancy.

Fifteen patients with primary intrahepatic biliary malignancy (cholangiocarcinoma in 13, biliary cystadenocarcinoma in two) were examined by computed tomography (CT). The CT features were classified into three types: (A) a well-defined round cystic mass with internal papillary projections, (B) a localized intrahepatic biliary dilatation without a definite mass lesion, and (C) miscellaneous low-density masses. Intrahepatic biliary dilatation was noted in all cases of Types A and B and half of those of Type C; dilatation of extrahepatic bile ducts occurred in 4/4, 1/3, and 0/8, respectively. CT patterns, such as a well-defined round cystic mass with papillary projections or dilatation of intra- and extrahepatic ducts, give important clues leading to a correct diagnosis of primary intrahepatic biliary malignancy.

Adenoma, Bile Duct↗
PubMed1983

A new method for quantitative analysis of thallium-201 myocardial image-"corrected" circumferential profile method.

A new method for computer-assisted quantitative analysis of a thallium (Tl)-201 myocardial image ("corrected" circumferential profile method) was described. Since the Tl-201 myocardial image of a normal subject is not homogeneous, an attempt was made to correct for this non-homogeneity. Three groups of subjects were studied, including 10 normal volunteers (group A, mean age of 27.5 years), 14 patients with atypical chest pain and normal coronary arteriogram (group B, mean age of 56.7 years) and 16 patients with first transmural myocardial infarction (group C, mean age of 71.0 years). The myocardial images were acquired at rest at anterior, left anterior oblique (30 degrees and 60 degrees) and left lateral projections. With a scintigram, the left ventricle was outlined and divided into 24 radial segments by radii drawn from the center of the left ventricle. Average radioactivity per pixel in normal subjects was obtained in each segment and normalized to the highest segment (= 100%). The ratio of 100% to the mean of normalized radioactivity in percent in each segment from 10 normal volunteers was calculated and designated as a correction factor for each segment. After the correction of average radioactivity per pixel in each segment using this correction factor and after relating it to the highest radioactive segment, the mean (= 100%) and standard deviation (SD) were calculated and (100-4SD)% was defined as the normal lower limit. In the scintigram of groups B and C, "corrected" circumferential profiles were obtained from the regional radioactivity multiplied by the correction factor, normalized to the highest segment (100%) and compared with the lower normal limit. The ratio (%) of the area of patient's circumferential profile curve below the normal limit to the total area below the normal limit was obtained at each view and the sum of them was called the total "corrected" defect score. Infarct size analyzed by the "corrected" circumferential profile method correlated well with that analyzed by visual interpretation, and was useful in differentiating group C from group B.

Adult↗
PubMed1983

Computed tomography and sonography of cavernous hemangioma of the liver.

Accuracy and limitations of computed tomography (CT) and sonography in the detection and diagnosis of cavernous hemangioma of the liver were analyzed in 39 cases. In 35 of 38 lesions examined by CT before and after bolus contrast enhancement, findings were dense contrast enhancement spreading in all directions on subsequent scans and/or density (other than capsule or septa) higher than normal hepatic parenchyma after 2 min. Lesions smaller than 1 cm were not detected. Misregistration in sequential scans prevented diagnosis of three of nine lesions smaller than 2 cm. Sonography revealed various patterns of mass, but in the smaller lesions, an extremely hyperechoic pattern was dominant. The contributions of CT and sonography depend on the size of the lesions.

Adult↗
PubMed1983

[Visualization of cerebellopontine angle diseases by nuclear magnetic resonance imaging].

The preliminary results from the clinical use a prototype whole body nuclear magnetic resonance (NMR) machine constructed by Toshiba Inc. are presented. Cranial NMR scans were performed on more than 30 cases with broad spectrum of neurologic diseases using saturation-recovery and inversion-recovery sequences with a field strength of 1500 Gauss. Selective excitation sequence was used for the slice selection and filtered backprojection was used to reconstruct the images. They were displayed on a 256 X 256 matrix as 12 mm thick sections. Data acquisition time varied between 3 and 12 minutes. Our initial experiences with six cases harboring cerebellopontine angle lesions disclosed advantages and disadvantages of NMR imaging in comparison with X-ray CT. The advantages were the absence of linear artifacts from the surrounding bone, the marked gray-white matter differentiation, and the variety of tomographic planes available. The disadvantages included the lack of bone detail, the lack of visualization of the major intracranial vessels, and the long time required for scanning (several minutes per slice). Although much continued evaluation is necessary, NMR seems to have vast potential as a diagnostic tool.

Adult↗
PubMed1983

[Computed tomography of suprasellar cystic lesions].

Difficulties are often encountered in the differential diagnosis of suprasellar cystic lesions in computed tomography (CT). During the past 5 years and 7 months we experienced 22 such cases. In this report we tried to review the characteristic CT findings for the differential diagnosis of these lesions. Population of this study is consisted by 7 pituitary adenomas (4 non-functioning adenomas, 2 prolactinomas and 1 GH-secreting adenoma), 8 craniopharyngiomas, 4 arachnoid cysts and 3 Rathke's cleft cysts. In cases of pituitary adenomas and craniopharyngiomas, we included only those cases which were found to be completely cystic. Each case was scanned before and after contrast material injection and in majority of cases coronal scans were also obtained after contrast injection. The analysis was based on the CT appearance of the shape, the content and the wall of each cyst. The wall of the cyst was evaluated according to its thickness, density, presence of calcification and contrast enhancement. In 14 out of 22 cases the X-ray attenuation values of their content were calculated after setting the ROI in the cyst on the CT display console. Craniopharyngioma often showed calcification in its wall, which was not seen in the wall of pituitary adenoma. The wall of pituitary adenoma revealed contrast enhancement in all cases, but half of craniopharyngioma showed no contrast enhancement in its wall. These two points are useful for the differential diagnosis of these lesions which we encounter most frequently.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗