Deep venous thrombosis of the lower extremity: efficacy of spiral CT venography compared with conventional venography in diagnosis.
OBJECTIVE
To compare the efficacy of spiral computed tomographic (CT) venography with conventional venography in the diagnosis of suspected deep venous thrombosis (DVT).


METHODS
In a prospective study, 52 consecutive patients with clinically suspected unilateral or bilateral DVT were studied with CT venography and conventional venography. In cases in which conventional venographic findings were inconclusive, color-coded duplex sonography and follow-up examinations were performed to make a final diagnosis. CT venography of both extremities covered a 100-cm section from the ankle to the inferior vena cava (IVC). Contrast material diluted with saline was injected in a dorsal vein of each foot. CT and conventional venography (including color-coded duplex sonography and follow-up findings) were correlated for three venous regions for each patient.


RESULTS
Correlation was excellent between CT and conventional venographic findings in the detection of DVT. The sensitivity of CT venography was 100% (confidence interval: 0.92, 1.00), specificity was 96% (confidence interval: 0.84, 0.98), positive predictive value was 91%, and negative predictive value was 100%. CT venography more clearly demonstrated thrombus extension of DVT into the pelvic veins and IVC than conventional venography alone.


CONCLUSIONS
CT venography is a valuable tool in the diagnosis of DVT. Compared with conventional venography, CT requires use of 80% less contrast material.
Baldt
M M
MM
Department of Radiology, University of Vienna Medical School, Austria.
Zontsich
T
T
Stümpflen
A
A
Fleischmann
D
D
Schneider
B
B
Minar
E
E
Mostbeck
G H
GH
D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007472:Iohexol; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010690:Phlebography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013924:Thrombophlebitis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D007472:Iohexol