Technetium-99m labelled red blood cells scintigraphy and not iminodiacetic acid cholescintigraphy facilitates the discrimination of hepatic cirrhosis from fibrosis

Objective: This pilot study was designed to investigate the efficacy of technetium-99m labelled red blood cells (^99mTc-RBC) compared with ^99mTc-mebrofenin cholescintigraphy (^99mTc-MHS), in the diagnosis of hepatic dysfunction at early stages. Subjects and Methods: Twenty four patients, 8 with hepatic fibrosis and 16 with cirrhosis, at Child-Pugh stage A to C and 20 age-matched controls were examined by ^99mTc-RBC and by ^99mTc-MHS. Dynamic acquisition and static images were semiquantitatively analused by studying the liver-to-heart (L/H) ratio estimated by both the ^99mTc-RBC and ^99mTc-MHS methods. The L/H ratios were compared between fibrosis, cirrhotic stages and controls, by Student's t test. Linear regression analysis of the L/H ratios for both methods has been applied in the whole study population. Results: Labelled RBC could statistically differentiate fibrotic from normal liver parenchyma (P<0.001), whereas the ^99mTc-MHS could not (P: 0.13). The L/H ratios of cirrhotic lesions using both methods were significantly lower than those in controls: (P<0.000001 for ^99mTc-RBC and P<0.0001 for ^99mTc-MHS). Statistically significant difference was demonstrated by both modalities between fibrotic and cirrhotic lesions (^99mTc-RBC: P: 0.003 and ^99mTc-MHS: P: 0.024). Conclusion: Our study although in a limited number of patients suggested that as opposed to ^99mTc-MHS, scintigraphic evaluation by ^99mTc-RBC could be useful in the discrimination of patients with liver fibrosis, cirrhosis and in normal controls.