Discordant uptake of three different agents for liver scintigraphy in a patient with focal nodular hyperplasia

Regional radioactivity discrepancy between Tc-99m GSA and Tc-99m phytate liver scans in a patient with massive hepatic necrosis

A 22-year-old woman with severe acute hepatitis underwent a Tc-99m galactosyl human serum albumin (GSA) scan. Intense accumulation was observed in the cephalic region of the right hepatic lobe, whereas the accumulation was reduced in the left lobe and the caudal region of the right lobe. A computed tomographic (CT) scan showed that the left lobe and the caudal region of the right posterior segment had atrophied and become hypodense, which were thought to represent postnecrotic scarring after massive hepatic necrosis. The relatively hyperdense region in the right lobe was slightly swollen and was thought to represent regenerating liver tissue or a "potato liver." Compared with the CT, the regions of elevated Tc-99m GSA accumulation correlated well with the areas of regenerating liver tissue, and the regions with reduced accumulation corresponded closely with the areas of postnecrotic scarring. On a Tc-99m phytate scan, unlike the Tc-99m GSA scan, the radiocolloid accumulation was intense in the left lobe and caudal region of the right lobe and reduced in the cephalic region of the right lobe. Together, the Tc-99m GSA scan and the Tc-99m phytate scan formed a set of exact "nega-posi" images. Biopsy specimens obtained during laparoscopy showed a few hepatocyte columns in the postnecrotic scarred left lobe. Severe disruption of the hepatocytes, prominent inflammatory cell infiltration, and obvious Kupffer cell hypertrophy and clustering were also observed.

Nontumorous decrease in Tc-99m GSA accumulation

Nontutimorous decrease in 99mTc-GSA accumulation has not been well covered in the literature. Understanding of this phenomenon is, however, essential for accurate evaluation of regional hepatic function. Scintigrams (transaxial SPECT) of 269 patients who underwent 99mTc-GSA liver scintigraphy were reviewed for the presence of nontumorous decreases in 99mTc-GSA accumulation. Nontumorous decreases in 99mTc-GSA accumulation were seen in 32 of 269 patients (12%). In 16 of the 32 patients (6%), nontumorous decreases in 99mTc-GSA accumulation corresponded to regional decrease in portal venous flow. The causes of such decrease in portal venous flow were portal thrombus of hepatocellular carcinomas in eight patients, portal venous stenosis or occlusion by hilar cholangiocarcinomas in five patients, inter alia. In eight patients (3%), the regions with decreased 99mTc-GSA accumulation correlated with massive hepatic necrosis in fulminant hepatitis, scar in hepatitis, or confleuent in portal venous flow, lobar biliary stasis, or both. In four patients (1.5%), the exact causes of nontumorous decrease in 99mTc-GSA accumulation could not be determined.