Naoko Ikeoka

Usefulness of per-rectal portal scintigraphy with Tc-99m pertechnetate for galactosemia in infants

Gaiactosemia discovered by newborn screening is rarely caused by enzyme deficiency. It has recently been reported that among patients without enzyme deficiency portosystemic shunting may be a cause of galactosemia in some patients. We did per-rectal portal scintigraphy in patients with such galactosemia detected during screening of newborns to examine the usefulness of this method for the diagnosis of portosystemic shunts via the inferior mesenteric vein. The subjects were eight neonates with galactosemia without enzyme deficiency detected during screening. A solution containing technetium-99m pertechnetate was instilled into the rectum, and serial scintigrams were taken while radioactivity curves for the liver and heart were recorded sequentially. The per-rectal portal shunt index was determined by calculating the ratio for counts of the liver to counts for the heart integrated for 24 seconds immediately after the appearance of the liver time-activity curve. A portosystemic shunt was detected in both of the patients with a shunt index of 30% or more, but not in the six patients with a shunt index less than 30%. The blood galactose levels of these six patients later entered the reference range. This method is noninvasive and there is little exposure to the radionuclide. It seemed to be useful for the diagnosis of portosystemic shunt in newborns with galactosemia without enzyme deficiency.

Hypereosinophilic syndrome appearing as a focal defect on liver scan

The case reported here is of a 34-year-old man diagnosed as having hypereosinophilic syndrome. Blood tests showed a large increase in the number of eosinophils and a slight increase in asparate aminotransferase and alkaline phosphatase. In scintigraphy of the liver with Tc-99m-phytate and with Ga-67-citrate, a focal defect was found in the outer part of the right lobe of the liver. Abdominal computed tomography showed a low density lesion in the same area. Histological inspection of the biopsy specimen showed heavy periportal infiltration with eosinophils. The results suggested that the focal defect seen in liver scintigraphy arose from a circulatory disturbance arising from infiltration by eosinophils.

Diagnosis of chronic liver disease from liver scintiscans by artificial neural networks

Artificial neural networks were used in the diagnosis of chronic liver disease based on liver scintiscanning. One hundred and thirty-seven patients with chronic liver disease (12 with chronic persistent hepatitis, 39 with chronic aggressive hepatitis, and 86 with cirrhosis) and 25 healthy controls were studied. Sixty-five subjects (10 healthy controls, 20 patients with chronic hepatitis, and 35 patients with cirrhosis of the liver) were used in the establishment of a neural network. Liver scintiscans were taken starting 20 min after the intravenous injection of 111 MBq of Tc-99m-phytate. The neural network was used to evaluate five items judged from information on liver scintiscans: the ratio of the sizes of the left and right lobes, splenomegaly, radioactivity in the bone marrow, deformity of the liver and distribution of radioactivity in the liver. The neural network was designed to distinguish between three liver conditions (healthy liver, chronic hepatitis and cirrhosis) on the basis of these five items. The diagnostic accuracy with the neural network was 86% for patients with chronic hepatitis and 93% for patients with cirrhosis. With conventional scoring, the accuracy was 77% for patients with chronic hepatitis and 87% for patients with cirrhosis. Our findings suggest that artificial neural networks may be useful for the diagnosis of chronic liver diseases from liver scintiscans.

Significance of blood flow in the inferior and superior mesenteric veins for the formation of oesophageal varices

The degree of involvement of blood flow in the superior mesenteric vein and inferior mesenteric vein in the formation of oesophageal varices is not known. We have developed a method by which the contributions of these veins to portal blood flow can be evaluated simultaneously in a relatively non‐invasive way. An enteric‐coated capsule containing [123I]iodoamphetamine (IMP) is given by mouth and 3 h later [123I]IMP is instilled into the rectum. The data obtained are treated by computer to calculate the portal shunt index via the inferior and superior mesenteric veins. In chronic hepatitis and cirrhosis, when varices were absent, the difference in these indices was not significant. In the presence of varices, the portal shunt index via the inferior mesenteric vein was significantly higher than that via the superior mesenteric vein. It was suggested that the contribution of blood flow in the inferior mesenteric vein the portal/splenic axis is important in the formation of varices.

Portal circulation in monkeys and humans studied after ingestion of a capsule containing a radionuclide.

Capsules (8 times 30 mm) of technetium‐99m pertechnetate were designed for measurement of portal blood flow. Most of the radionuclide entered the superior mesenteric vein. The capsule was taken orally and monitored with a collimator for scintigraphy until it reached the small intestine, when a magnetic field completed an electrical circuit in a sensor, burning a thread, releasing a spring, and discharging the preparation.

Portal circulation before and after sclerotherapy for oesophageal varices studied by radionuclide angiography

Radionuclide angiography was used to generate curves of first‐pass radioactivity vs. time for the right hepatic lobe and both kidneys following the rapid intravenous injection of 10 mCi of 99mTc‐phytate. By analysis of the right hepatic curve, the arterial and portal components of the liver circulation were calculated in 21 healthy subjects and 183 patients, 39 with chronic hepatitis and 144 with cirrhosis of the liver.

Diagnosis of hepatocellular carcinoma by factor analysis

We examined the usefulness of factor analysis for the diagnosis of hepatocellular carcinoma by analysis of the data obtained by radionuclide angiography. The data could be separated into two factors, a hepatic phase (hepatic artery and portal vein) and an arterial phase (aorta and kidney). In patients with hepatocellular carcinoma, the factor of the tumor is included in the arterial phase, so that the cancerous region could be differentiated from the noncancerous region. The ratio of the radioactivity of the cancerous region to the noncancerous region was used to estimate the blood flow of the tumor region.