Assessment of deep venous thrombosis in the lower limbs and pelvis: MR venography versus duplex Doppler sonography.

OBJECTIVE

This study was designed to compare the diagnostic value of MR venography and color Doppler sonography in the assessment of deep venous thrombosis.

SUBJECTS AND METHODS

MR venograms and color Doppler examinations were obtained in 37 patients either with suspected deep venous thrombosis of the lower limbs or pelvis or with pulmonary embolism. Two-dimensional time-of-flight venography was used for all studies. MR and color Doppler data were collected prospectively and analyzed in a blinded manner. In a subset of 21 patients, MR venography and color Doppler sonography were prospectively compared with contrast-enhanced venography.

RESULTS

When compared with contrast-enhanced venography, MR venography was 100% sensitive and 100% specific in the diagnosis of deep venous thrombosis above the knee. Color Doppler imaging depicted 13 of 15 cases of deep venous thrombosis and 5 of 6 venous examinations that had normal results, yielding a sensitivity and a specificity of 87% and 83%, respectively. The differences in sensitivity and specificity between MR venography and color Doppler sonography were not statistically significant. MR venography was 95% sensitive and 99% specific in detecting the extension of deep venous thrombosis, compared with the 46% sensitivity and 100% specificity of color Doppler sonography (differences in sensitivity, p < .01). MR images showed 29 collateral vessels, whereas only 21 were detected by contrast-enhanced venography (p < .04).

CONCLUSION

MR venography seems to be more accurate than color Doppler sonography in detecting the extension of deep venous thrombosis. The positive diagnosis and extent of deep venous thrombosis can be easily detected and monitored by a noninvasive technique such as MR venography.