Analysis of enhancement pattern of flat gallbladder wall thickening on MDCT to differentiate gallbladder cancer from cholecystitis.
OBJECTIVE
The objective of our study was to determine the diagnostic value of analyzing the pattern of gallbladder wall enhancement on MDCT to characterize diffuse gallbladder wall thickening as benign or malignant.


METHODS
MDCT scans obtained during the portal venous phase in 78 patients with gallbladder wall thickening caused by various pathologic conditions were retrospectively reviewed by two blinded observers. The CT features of benign and malignant gallbladder wall thickening were compared by means of univariate and multivariate analyses. The study cases were then divided into five patterns according to enhancement pattern. Using these five patterns, two radiologists reviewed the MDCT images and recorded their diagnostic confidence for differentiating benign versus malignant cause on a 5-point scale. The diagnostic performance of CT was evaluated by each observer using a receiver operating characteristic curve analysis.


RESULTS
The thicknesses of the inner and outer layers ("thick" enhancing inner layer > or = 2.6 mm, "thin" outer layer < or = 3.4 mm), strong enhancement of the inner wall, and irregular contour of the affected wall were significant predictors for a malignant cause of gallbladder wall thickening (p < 0.001). The two-layer pattern with a strongly enhancing thick inner layer and weakly enhancing or nonenhancing outer layer and the one-layer pattern with a heterogeneously enhancing thick layer were patterns that were significantly associated with gallbladder cancer (p < 0.05). When we consider those two enhancing patterns as a sign of malignancy, the diagnostic accuracy of MDCT was 89.1% and 87.6% for the two observers, respectively.


CONCLUSIONS
Analyzing the enhancement pattern of a thickened gallbladder wall on MDCT is helpful in differentiating gallbladder cancer from benign inflammatory diseases.
Kim
Soo Jin
SJ
Department of Radiology and Institute of Radiation Medicine, Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea.
Lee
Jeong Min
JM
Lee
Jae Young
JY
Kim
Se Hyung
SH
Han
Joon Koo
JK
Choi
Byung Ihn
BI
Choi
Jin Young
JY
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002764:Cholecystitis / Q000000981:diagnostic imaging*; D002765:Cholecystography / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D005706:Gallbladder Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*