Department of General Internal Medicine, Omiya Medical Center, Jichi Medical School
Acceleration time index, Fast Fourier transformation, Gallbladder carcinoma, Resistance index, Ultrasonic Doppler
The fast Fourier transformation (FFT) wave forms of blood flow signals obtained with the ultrasonic and endoscopic ultrasonic Doppler methods (UD and EUD) were analyzed in order to differentiate malignant lesions from those of several benign gallbladder diseases noninvasively. The subjects were 14 patients with gallbladder carcinomas, 8 with adenomyomatosis, 8 with acute cholecystitis, and 10 with normal gallbladders. Pulsatile flow wave signals (PW) were received by UD or EUD, and maximal and minimal velocity (Vmax and Vmin), acceleration time (AT), and periodic time (PT) were determined. Resistance index (RI) was calculated as the value of the difference between Vmax and Vmin divided by Vmax; acceleration time index (ATI) was defined as the value of AT divided by PT. The ability of the Vmax, RI, and ATI indices to provide a satisfactory basis for judging malignancy was investigated. Vmax tended to be higher in gallbladder carcinomas than in adenomyomatosis, acute cholecystitis, or normal gallbladders, although the difference was not statistically significant on analysis of variance. The RI and ATI of carcinomas were significantly higher than those of the other groups, however. Gallbladder carcinoma could be differentiated with 100% sensitivity, 84.6% specificity, and 90% overall accuracy when RI and ATI were set at or above 0.80 and 0.13, respectively. These results suggest that blood flow analysis by UD or EUD would be useful in the differential diagnosis of gallbladder carcinoma and benign gallbladder diseases, including marked wall thickening or presence of tumor.