Search PubMed⌕ Search

Biomedical subjects

Y Itai

Publications and source records attributed to Y Itai.

At least 217 records · Page 12Linked to original sources
PubMed1989

[MRI and MRS in the diagnosis of cancer].

Characteristics and advantages of MRI (magnetic resonance imaging) in the diagnosis of cancer are represented using hepatic diseases as examples. MRI can detect as small as 10 mm lesion of hepatic tumor (less than 5 mm in favorite conditions) despite far longer acquisition time compared with CT. Although the prolongation of T1 (longitudinal relaxation time) and T2 (transverse relaxation time) is generally noted in cancer, the liver is the sole organ where in vivo measurement of T2 makes it possible to differentiate primary malignant tumor (hepatocellular carcinoma) from the most common benign tumor (cavernous hemangioma). Gd-DTPA, the clinically used contrast material on MRI, is as useful as iodine contrast material on dynamic CT for differentiation among hepatic tumors, and is safely administered in larger dose. Proton spectroscopic imaging can distinguish the signals of proton from water and fat, and can detect the presence of fat more specifically. Intravoxel incoherent motion imaging is a new technique to demonstrate diffusion (Brownish movement) and perfusion (blood flow in capillary) in the voxel as image, and has possibility to reveal the vascularity of tumor without contrast material. MRS (magnetic resonance spectroscopy) has been obtainable in vivo under the guidance of proton MRI. The pattern of 31P-MRS is essentially nonspecific but phosphorous compounds rapidly change in proportion after effective treatment against cancer. Therefore, 31P-MRS is useful in the early and noninvasive evaluation of anticancer treatment. Finally the so-called Fossel effect (widths of methyl and methylene of lipoprotein on 1H-MRS of plasma becomes narrow in patients with cancer) and critical paper against Fossel are discussed.

Carcinoma, Hepatocellular↗
PubMed1989

[Collaterals of portal hypertension running through the liver. Part 1. Paraumbilical vein].

Seven cases of portosystemic collateral running through the left lobe of the liver (6 in the medial segment and 1 in the lateral segment) were reported. Six cases were diagnosed by CT and/or ultrasound, and one case was confirmed by autopsy. This collateral originated from the umbilical vein recess of the left portal vein and connected with enlarged vein in front of the left lobe of the liver. All the patients had other portosystemic collaterals of severe and moderate degrees. Paraumbilical veins demonstrated on portography did not differ from ordinary paraumbilical veins in portal hypertension except for prominent tortuosity and dilatation noted in half cases. In markedly dilated cases, intrahepatic portosystemic collateral can be a pitfall in the diagnosis of hepatic tumor on CT. Careful examination of portal hypertension with ultrasound, dynamic CT and/or magnetic resonance imaging will detect such portosystemic collaterals running through the hepatic parenchyma.

Collateral Circulation↗
PubMed1989

Pancreatitis in the annulus of annular pancreas demonstrated by the combined use of computed tomography and endoscopic retrograde cholangiopancreatography.

Annular pancreas, an uncommon condition, is often hard to diagnose before operation. We report a case of annular pancreas with pancreatitis of the annulus that was diagnosed by the use of computed tomography followed by endoscopic retrograde cholangiopancreatography. An upper gastrointestinal series and duodenoscopy revealed stenosis of the second portion of the duodenum. Computed tomography revealed enlargement of the annulus of the pancreas. Two years later, follow-up computed tomography demonstrated calcifications of the annulus, although the remaining pancreas seemed to be normal.

Adult↗
PubMed1988

Segmental intensity differences in the liver on MR images: a sign of intrahepatic portal flow stoppage.

Segmental intensity differences (SIDs) in hepatic parenchyma free of tumor were noted in six patients with hepatic masses (hepatocellular carcinoma in five and metastatic liver cancer in one). Areas of SID were homogeneous in intensity. The intensity of the affected region was high in all six patients on T2-weighted magnetic resonance (MR) images and low in two on T1-weighted images. Three of five patients examined with plain computed tomography (CT) had corresponding segmental areas of low attenuation. Angiograms obtained in five patients showed occlusion of the intrahepatic portal vein, segmental staining corresponding to the region of the SID, or both. Twelve of 82 patients examined with MR imaging and angiography had similar findings on angiograms, and ten of them had abnormal intensity of anatomic distribution around or beside the liver tumors on MR images. MR imaging may be more sensitive than plain CT in the detection of secondary changes caused by intrahepatic portal flow stoppage.

Angiography↗
PubMed1988

Mucin-hypersecreting intrahepatic biliary neoplasms.

The radiologic findings are described in six patients with "mucin-hypersecreting" intrahepatic biliary neoplasms (biliary cystadenocarcinoma or papillary cholangiocarcinoma). Massive amounts of mucin were confirmed in the dilated bile ducts at surgery or autopsy. Computed tomography (CT) and ultrasound (US) demonstrated severe dilatation of the intrahepatic bile ducts distal to the tumor in all patients and of extrahepatic ducts in five. On cholangiograms, large, amorphous filling defects caused by retention of mucin were found in the dilated ducts in three patients. The tumor was multilocular and cystic in five patients; in the other patient it was too small to be detected at CT or US. The presence of liver tumor (mostly multilocular and cystic), marked biliary dilatation distal to the tumor, and filling defects in the dilated bile ducts are important findings that indicate a mucin-hypersecreting intrahepatic biliary neoplasm.

Adenoma, Bile Duct↗
PubMed1988

Hepatocellular carcinoma and cavernous hemangioma: differentiation with MR imaging. Efficacy of T2 values at 0.35 and 1.5 T.

Seventy-two patients with hepatocellular carcinoma (hepatoma) and 56 with hemangioma were studied with magnetic resonance (MR) imaging at 0.35 or 1.5 T to evaluate the efficacy of T2 values in differential diagnosis. T2 values were calculated with the two-point method. The mean T2 values of hepatoma and hemangioma were 58.9 msec +/- 8.9 and 101.6 msec +/- 25.8 at 0.35 T and 49.1 msec +/- 9.8 and 85.3 msec +/- 21.2 at 1.5 T. The difference in the T2 values for hepatoma and hemangioma was statistically significant (P less than .001) at both 0.35 and 1.5 T. Fifty-three of 56 lesions (94.6%) at 0.35 T and 86 of 102 lesions (84.3%) at 1.5 T were correctly classified when the T2 borderline between hepatoma and hemangioma was set at 80 msec. All misdiagnosed lesions were hemangioma, and all but one were smaller than 2 cm. However, over 90% of lesions smaller than 2 cm were correctly diagnosed when 70 msec at 0.35 T and 60 msec at 1.5 T were used as borderline T2 values. MR imaging with T2 measurement was very useful for differentiating between hepatoma and hemangioma (including small lesions) at 1.5 T as well as at 0.35 T.

Adult↗
PubMed1987

Hepatic tumors: dynamic MR imaging.

Thirty-six patients with hepatic tumors (28 hepatocellular carcinomas, seven cavernous hemangiomas, one metastatic tumor) were examined with serial magnetic resonance (MR) imaging, after a bolus intravenous injection of 0.05 mmol/kg gadolinium-diethylenetriaminepentaacetic acid. A typical MR imaging pattern for hemangiomas (present in five of seven cases [71.4%]) was a lesion of diminished signal intensity on precontrast images, peripheral contrast enhancement during the bolus dynamic phase, and complete fill-in of high signal intensity on delayed scan images. Twenty-eight hepatocellular carcinomas showed a variety of contrast enhancement patterns during the dynamic phase. In 21 patients (75%), there was no area of high signal intensity within the tumor on the delayed phase. A peripheral halo with delayed enhancement was noticed in 12 patients (42.8%) Histologic correlation in hepatocellular carcinomas showed that the degree of contrast enhancement corresponded to tumor vascularity and that the peripheral halo corresponded to fibrous capsular structure.

Carcinoma, Hepatocellular↗
PubMed1987

Mucin-hypersecreting carcinoma of the pancreas.

Five cases of prominent, diffuse dilatation of the main pancreatic duct caused by mucin-hypersecreting carcinoma are reported. Adenocarcinoma was noted mainly within one markedly dilated main pancreatic duct. On endoscopic retrograde pancreatograms, dilated main pancreatic ducts with amorphous or well-defined filling defects resulting from mucin (five patients) or tumor (one patient) were noted. The proximal portion of the main pancreatic duct alone was delineated in three cases because of reflux of contrast material as a result of the presence of excessive mucin and a patulous orifice of the papilla of Vater (major duodenal papilla). Diffuse dilatation of the main pancreatic duct was demonstrated or suggested on computed tomographic (CT) and ultrasound scans. Four patients who underwent operations are alive and free from carcinoma (mean, 50 months after diagnosis). Whenever prominent, diffuse dilatation of the main pancreatic duct is encountered on CT or ultrasound scans, endoscopic retrograde pancreatography is mandatory to permit confirmation or ruling out of mucin-hypersecreting carcinoma of the pancreas.

Adenocarcinoma↗
PubMed1987

Regenerating nodules of liver cirrhosis: MR imaging.

A large number of tiny (0.5-1.5 cm), low-intensity nodules of the liver were retrospectively observed on T2-weighted magnetic resonance (MR) images of eight patients with cirrhosis of the liver. The lesions were not detected with other imaging modalities and were considered to be regenerating nodules. Twenty-five consecutive cases of liver cirrhosis referred for MR examination were prospectively investigated to study the detectability of regenerating nodules and the optimal pulse sequence for detection. A large number of small, low-intensity nodules were demonstrated in nine of 25 cases on T2-weighted spin-echo (SE) images, in nine of 22 cases on T1-T2 complex fast low-angle shot (FLASH) images, and in one of eight cases on T1-weighted SE images. FLASH images obtained with respiratory suspension most clearly revealed regenerating nodules. However, T2-weighted SE images clearly permit differentiation of high-intensity hepatocellular carcinoma, including small daughter lesions, from low-intensity regenerating nodules.

Aged↗
PubMed1987

Retained surgical sponges: CT and US appearance.

The computed tomographic (CT) and ultrasonographic (US) appearances of retained surgical sponges are described. In each case, the presence of a sponge was confirmed at repeat operation. CT examinations were performed in nine patients. In six cases, a low-density mass was demonstrated; in two cases, a complex mass with areas of both low and medium density was seen. The remaining case was a high-density mass. After intravenous administration of contrast material, dense and prolonged enhancement of the rim of the mass was noted in five of eight cases. Calcification was found in four cases, and spongiform gas in one. US performed in six patients revealed an echogenic area with strong acoustic shadowing in three cases and a complex mass, a hypoechoic mass, and a cystic mass with irregular internal echoes in one case each. Granuloma caused by a retained surgical sponge should be considered as a cause of an abdominal mass in patients with a history of prior abdominal surgery.

Abdomen↗