Differential diagnosis of gall-bladder masses using colour Doppler ultrasonography

To evaluate the diagnostic accuracy of colour Doppler ultrasonography in the differential diagnosis of gall-bladder lesions, we studied colour Doppler flow imaging of gall-bladder masses in 75 patients with gall-bladder masses, including 26 patients with cancer, 18 with benign polyps, 10 with adenomyomatosis and 21 with pseudo-tumorous sludge and 28 healthy subjects as controls. The presence of a colour signal, pattern of the colour signal, blood flow velocity and resistive index (RI) within lesions were assessed using colour Doppler ultrasonography. In cancerous lesions, the colour signal pattern was diffuse or arborizing (sensitivity 90.5% (19/21); specificity 62.5% (10/16)) and the velocity and RI were (mean ± s.d.) 39.0 ± 12.4 cm/s and 0.62 ± 0.12, respectively, which was significantly different (P< 0.01) compared with controls (11.4 ± 2.5 and 0.75 ± 0.03, respectively). The colour signal pattern obtained from polyps was linear at their base in 62.5% (10/16) of cases, but the velocity (13.6 ± 5.5) and RI (0.74 ± 0.08) did not differ from those of the controls. Lesions other than cancer and polyp had no colour signal. There were overlaps in the values of velocity and RI between malignant and benign lesions. When 20 cm/s for velocity and 0.65 for RI were used as the respective cut-off values, the sensitivity and specificity of this method in the diagnosis of malignant lesions was 95.2% (20/21) and 87.5% (14/16) for velocity and 66.7% (14/21) and 87.5% (14/16) for RI, respectively. In a prospective study consisting of 10 patients with cancer and 21 patients with polyps, the sensitivity and specificity were 90 and 66.7% for the colour signal, 100 and 100% for velocity and 80 and 90.4% for RI, respectively. In conclusion, colour Doppler ultrasonography can be useful in the diagnosis of gallbladder masses in combination with conventional ultrasonographic findings of gall-bladder masses, especially in the differentiation of cancers from benign lesions.