Simultaneous SPECT imaging of multi-targets to assist in identifying hepatic lesions

Molecular imaging technique is an attractive tool to detect liver disease at early stage. This study aims to develop a simultaneous dual-isotope single photon emission computed tomography (SPECT)/CT imaging method to assist diagnosis of hepatic tumor and liver fibrosis. Animal models of liver fibrosis and orthotopic human hepatocellular carcinoma (HCC) were established. The tracers of I-131-NGA and Tc-99m-3P-RGD(2) were selected to target asialoglycoprotein receptor (ASGPR) on the hepatocytes and integrin alpha(v)beta(3) receptor in tumor or fibrotic liver, respectively. SPECT imaging and biodistribution study were carried out to verify the feasibility and superiority. As expected, Tc-99m-3P-RGD(2) had the ability to evaluate liver fibrosis and detect tumor lesions. I-131-NGA showed that it was effective in assessing the anatomy and function of the liver. In synchronized dual-isotope SPECT/CT imaging, clear fusion images can be got within 30 minutes for diagnosing liver fibrosis and liver cancer. This new developed imaging approach enables the acquisition of different physiological information for diagnosing liver fibrosis, liver cancer and evaluating residual functional liver volume simultaneously. So synchronized dual-isotope SPECT/CT imaging with Tc-99m-3P-RGD(2) and I-131-NGA is an effective approach to detect liver disease, especially liver fibrosis and liver cancer.