MR Venography with True Fast Imaging with Steady-state Precession for Suspected Lowerlimb Deep Vein Thrombosis

Abstract

To compare true fast imaging with steady-state precession (FISP) magnetic resonance (MR) venography for suspected deep vein thrombosis (DVT) with contrast agent-enhanced venography. This was a prospective study of randomly selected patients with a clinical suspicion of DVT of the lower limb. Standard contrast venography was performed and compared with MR venography from the inferior vena cava to the feet in 24 patients with use of true FISP sequences (repetition time, 3.74 msec; echo time, 1.8 msec). Two radiologists independently read the MR venography and contrast venography studies. Segment visibility, secondary signs of DVT, and additional diagnoses were noted. MR venography demonstrated all venous segments in the pelvis and thigh. When results were analyzed on a per-patient basis, there was good agreement between contrast venography and MR venography (kappa = 0.64; 95% CI, 0.33-0.94; P = .0001). When the venous system was analyzed on a segmental basis, there was very good agreement between contrast venography and MR venography (kappa = 0.81; 95% CI, 0.68-0.94; P = .0001). The sensitivity and specificity for DVT detection were 100% for the iliac and popliteal segments and 100% and 98%, 68% and 94%, and 87% and 98%, respectively, for the femoral, below-knee, and all veins. Eleven of 14 patients without DVT had an alternative diagnosis suggested by MR venography. MR venography with axial true FISP allows noninvasive rapid diagnosis of acute DVT in the iliac, femoral, popliteal, and calf muscle veins. MR venography is much less reliable in the tibial or peroneal veins. It may demonstrate a nonvenous cause of a patient's symptoms.