<qa>  What was the primary tumor of the liver?Recent studies have shown that CT scan is far from ideal for detection of primary as well as metastases to liver 5,6. A well designed study showed that CT scan missed 32 of the primary tumors of the liver. A prospective study of 100 patients with colorectal cancer showed that CT scan missed liver metastases in 37 of cases 5. Another prospective controlled study of 135 subjects showed that CT scan failed to detect liver metastases in 49 of patients with various malignancies 6. 