Hepatic neoplasms: detection with hepatoportal subtraction angiography--a new technique of DSA

A new technique for hepatic intraarterial digital subtraction angiography (DSA)--hepatoportal subtraction angiography (HPSA)--that emphasizes the enhancement of tumors by suppressing liver parenchymal enhancement has been developed. The tumor detection sensitivity of HPSA was evaluated prospectively in comparison with that of conventional hepatic intraarterial DSA, unenhanced computed tomography (CT) or CT enhanced with iodine-containing contrast material (conventional CT), CT with iodized oil, and ultrasound (US). For 84 detected lesions of hepatoma, the sensitivity of HPSA was 92%, statistically superior to the 71% of hepatic intraarterial DSA (P less than .002), the 42% of US (P less than .001), and the 39% of conventional CT (P less than .001) and nearly the same as the 90% of CT with iodized oil. Among 33 lesions of metastasis, HPSA depicted 91%; conventional CT, 93%; US, 87%; and hepatic intraarterial DSA, 76%. HPSA was more sensitive than hepatic intraarterial DSA, but the difference was not statistically significant. Compared with hepatic intraarterial DSA, HPSA enabled detection of more faintly enhanced tumors, and this technique was considered useful for detecting small hypervascular hepatic tumors.