Role of Time Parameters for CTA and CTAP in the Diagnosis of Hepatocellular Carcinoma

摘要

OBJECTIVE CT scans have become a conventional examination for hepato-cellular carcinoma. Computed tomography arteriography (CTA) and computed tomography arterial portography (CTAP) are more sensitive. In this investigation, we defined the optimal time of CTA and CTAP during a dynamic scan. METHODS CTAP: a 5 -F Yashiro catheter was inserted to the superior mesentery artery under DSA, and the whole liver scanned 6 s after contrast medium injection. CTA: the 5-F Yashiro was inserted to the proper hepatic artery and a scan of the whole liver was performed 6-8 s after contrast medium injection. RESULTS In CTA, the contrast between enhancement of liver cancer and the normal liver tissue reached a peak after the contrast medium had been injected for 6～8 s. The focus was concealed by non-pathological enhancement in three cases. When the scan was delayed to 30 s after injection, the lesion could be detected clearly (P < 0.05). The contrast of the image was not as good as 60～180 s after injection, and pathological enhancement also was not found (P > 0.05). During CTAP, the frequency of an abnorminal non-per-fusion area was 19.0% (4/21) at 6-8 s after injection; the contrast of low-per-fusion focus and the normal liver was evident and the lesion could be detected clearly (P < 0.01). The contrast was decreased at 120-180 s after injection and the image was not as clear (P > 0.05). CONCLUSION CTA and CATP are effective techniques to detect small hep-atocellular carcinoma, to define the position of lesions and to estimate the feasibility of resection.