CT prediction of histological grade of hypervascular hepatocellular carcinoma: utility of the portal phase.
OBJECTIVE
To elucidate whether the attenuation of hypervascular hepatocellular carcinoma (HCC) on the portal phase of dynamic CT is correlated with histological grade.


METHODS
This study group consisted of 66 patients with 74 surgically resected, hypervascular HCCs. On a preoperative dynamic study with a 64-multidetector row CT, the portal phase was scanned 60 s after injecting the contrast agent following the pre-contrast image and hepatic arterial phase. The tumor attenuation of each HCC on the portal phase was categorized into high, iso-, or low, and was compared with the predominant histological grade using Mann-Whitney's U test.


RESULTS
Twenty-nine, 29, and 16 HCCs showed high, iso-, and low attenuation on the portal phase, respectively. Tumors were classified into three well- (w-), 58 moderately (m-), or 13 poorly (p-) differentiated HCCs. The tumor attenuation of p-HCC on the portal phase was significantly lower than those of w-HCC and m-HCC (p < 0.05 and p < 0.00001).


CONCLUSIONS
The tumor attenuation on the portal phase may help when diagnosing the histological grade of hypervascular HCC. p-HCC are considered to show a faster contrast washout than w-HCC and m-HCC.
Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. anishie@radiol.med.kyushu-u.ac.jp
Akihiro
A
Nishie
Kengo
K
Yoshimitsu
Daisuke
D
Okamoto
Tsuyoshi
T
Tajima
Yoshiki
Y
Asayama
Kousei
K
Ishigami
Daisuke
D
Kakihara
Tomohiro
T
Nakayama
Yukihisa
Y
Takayama
Ken
K
Shirabe
Nobuhiro
N
Fujita
Hiroshi
H
Honda
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007479:Iopamidol; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D011856:Radiographic Image Enhancement / Q000379:methods; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D055815:Young Adult
D003287:Contrast Media; D007479:Iopamidol