A novel display of reconstruction computed tomography for the detection of small hepatocellular carcinoma.
OBJECTIVE
To evaluate the usefulness of the alternate display of arterial and equilibrium phase images (ADAEI) of 2 mm-pitch reconstruction computed tomography (CT) in the detection of hepatocellular carcinoma (HCC).


METHODS
One hundred and eleven nodules in 72 patients were confirmed as HCC by radiology, histology, or clinical course. Blinded to the outcome, we retrospectively reviewed the CT images obtained with dual-phase spiral CT (Radix Prima, Hitachi Medical, Tokyo, Japan) by ADAEI and by conventional display on cut films. Scanning for the arterial and equilibrium phases was initiated at 33 and 120 s, respectively, after starting the injection of contrast medium (iopamidol 3 ml/s) with a section thickness of 5 mm and a table feed speed of 5-7 mm/s. In ADAEI, all images were reconstructed with a 2-mm interval, and displayed on the monitor in an alternating fashion so that an image in the arterial phase was followed by the corresponding image in the equilibrium phase, and then by the next pair of images in the craniocaudal direction.


RESULTS
All 20 HCC nodules larger than 20 mm in diameter were detected by both ADAEI and the conventional display (NS). On the other hand, detectability of smaller HCC nodules was 91/91 (100%) and 72/91 (79%), respectively (P<0.0001 by McNemar' test). False-positively identified HCC nodules, including those diagnosed as possible HCC, were 11 by ADAEI and eight by conventional display.


CONCLUSIONS
The novel, alternate display, ADAEI of 2 mm-pitch reconstruction CT images was useful in detecting small HCC nodules while not requiring additional equipment or expense.
Teratani
Takuma
T
University of Tokyo Graduate School of Medicine, Gastroenterology, Tokyo, Japan. teratani-2im@h.u-tokyo.ac.jp
Yoshida
Haruhiko
H
Haruhiko
Yoshida
Y
Shiina
Shuichiro
S
Shuichiro
Shiina
S
Obi
Shuntaro
S
Shuntaro
Obi
O
Sato
Shinpei
S
Shinpei
Sato
S
Koike
Yukihiro
Y
Yukihiro
Koike
K
Hamamura
Keisuke
K
Keisuke
Hamamura
H
Akamatsu
Masatoshi
M
Masatoshi
Akamatsu
A
Fujishima
Tomonori
T
Tomonori
Fujishima
F
Imai
Yasuo
Y
Yasuo
Imai
I
Kawabe
Takao
T
Takao
Kawabe
K
Shiratori
Yasushi
Y
Yasushi
Shiratori
S
Omata
Masao
M
Masao
Omata
O
D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D015331:Cohort Studies; D003287:Contrast Media; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011336:Probability; D011446:Prospective Studies; D011856:Radiographic Image Enhancement; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome
D003287:Contrast Media