Diagnostic performance of apparent diffusion coefficient for predicting histological grade of hepatocellular carcinoma.
OBJECTIVE
To investigate whether the histological grade of hepatocellular carcinoma (HCC) can be predicted using the apparent diffusion coefficient (ADC).


METHODS
This retrospective study group consisted of 80 patients with 85 surgically resected HCCs who underwent preoperative MRI exams including diffusion-weighted imaging. The tumors were histologically classified into five groups as follows: five well (w-), 17 well to moderately (wm-), 37 moderately (m-), 16 moderately to poorly (mp-), and 10 poorly (p-) differentiated HCCs. For ADC measurement of each HCC, the largest possible region of interest was placed on the solid region on the ADC map where ADC was considered to be the lowest. The average ADCs of the five histological grades were compared using Spearman's rank correlation test and Student's t-test, and the diagnostic performance of ADC for mp- and p-HCCs was also evaluated using a receiver operating characteristic-based positive test.


RESULTS
The average ADC of p-HCC (0.76±0.10×10(-3) mm2/s) was significantly lower than those of the other four histological grades. The average ADC of mp-HCCs (0.99±0.20×10(-3) mm2/s) was significantly lower than those of w-, wm- and m-HCCs. The sensitivity, specificity, PPV, NPV, and accuracy, when an ADC of 0.972 or lower was considered an indicator of mp- and p-HCCs, were 73.1%, 72.9%, 54.3%, 86.0% and 72.9%, respectively.


CONCLUSIONS
ADCs of mp- and p-HCCs were lower than those of w-, wm- and m-HCCs. ADC can contribute to radiological diagnosis of poorly differentiated components in HCCs.
Nishie
Akihiro
A
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
Tajima
Tsuyoshi
T
Asayama
Yoshiki
Y
Ishigami
Kousei
K
Kakihara
Daisuke
D
Nakayama
Tomohiro
T
Takayama
Yukihisa
Y
Okamoto
Daisuke
D
Fujita
Nobuhiro
N
Taketomi
Akinobu
A
Yoshimitsu
Kengo
K
Honda
Hiroshi
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000473:pathology* / Q000601:surgery; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies