Detection of hepatocellular carcinoma: value of adding delayed phase imaging to dual-phase helical CT.
OBJECTIVE
The purpose of our study was to determine the value of adding delayed phase imaging to dual-phase helical CT for the detection of hepatocellular carcinoma.


METHODS
One hundred thirteen patients with 131 hepatocellular carcinomas underwent triple-phase helical CT. The diagnosis was established by pathologic examination after surgical resection in all patients. For triple-phase helical CT, hepatic arterial, portal venous, and delayed phase scanning began 30, 60, and 180 sec, respectively, after the injection of 120 mL of iodinated contrast material. Dual-phase helical CT excluding delayed phase and triple-phase helical CT images were reviewed independently by three radiologists on a segment-by-segment basis. Diagnostic accuracy was assessed using receiver operating characteristic analysis in 330 resected segments. Sensitivities and specificities were calculated. The value of the delayed phase images in the characterization of hepatocellular carcinoma was also assessed.


RESULTS
The diagnostic accuracy of triple-phase helical CT including delayed phase (area under the curve [A(z)], 0.973) was significantly higher than that of dual-phase helical CT (A(z), 0.954). The mean sensitivity of triple-phase CT (89%) was also significantly higher than that of dual-phase CT (86%). The mean specificities of triple-phase CT (99%) and dual-phase CT (99%) were equal. Delayed phase images were helpful in the characterization of hepatocellular carcinoma in 14% of patients.


CONCLUSIONS
The addition of delayed phase imaging to dual-phase helical CT is valuable for the detection and characterization of hepatocellular carcinoma.
Lim
Jae Hoon
JH
Department of Radiology, Samsung Medical Center, 50 Ilwon-dong, Kangnam-ku, Seoul, Korea 135-710.
Choi
Dongil
D
Kim
Seung Hoon
SH
Lee
Soon Jin
SJ
Lee
Won Jae
WJ
Lim
Hyo Keun
HK
Kim
Seonwoo
S
D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D008102:Liver Circulation / Q000502:physiology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity; D013997:Time Factors; D014057:Tomography, X-Ray Computed