G.Y.HOW1, L.H.H.QUEK1, I.K.H.HUANG1, Z.W.J.LO1, E.M.YONG1, G.W.L.TAN1, U.PUA1
Tan Tock Seng Hospital1
This retrospective assessor-blinded cohort study aims to compare the diagnostic efficacy of non-contrasted magnetic resonance venogram (MRV) and intravascular ultrasonography (IVUS).
All patients without prior lower limb vascular stenting who underwent non-contrasted MRV (index test) and IVUS in our institution from January 2018 to May 2020 were included. Lower limb deep venous systems were sectioned by main branches. IVUS findings served as “reference standard” for stenosis (narrowing greater than 50% of the reference vessel diameter). Non-contrasted MRV images were reviewed by 3 board-certified Interventional Radiologists, blinded to IVUS findings. Final diagnosis by “majority rule”.
33 patients (110 segments had IVUS correlation) were included. 18 males (54.5%) and 15 females (45.5%). Majority were Chinese (63.6%). 24 patients had bilateral deep venous disease (72.7%). Mean age of patients was 59.0 years (26.0 – 79.5 years). Moderate agreement between the 3 Radiologists’ diagnoses on non-contrasted MRV, κ= .524 (95% CI, .426 to .623), p < .05. Non-contrasted MRV achieved a sensitivity of 96.10% (95% CI, 89.03% to 99.19%), specificity of 78.79% (95% CI, 61.09% to 91.02%), positive predictive value of 91.36% (95% CI, 84.54% to 95.33%) and negative predictive value of 89.66% (95% CI, 73.81% to 96.38%). 78.5% agreement was noted between non-contrasted MRV and IVUS. Good agreement between the index test and reference standard was noted, κ = .779 (95% CI, .645 to .907), p = < .05.
Non-contrasted MRV presents potential for a highly sensitive and specific screening tool for diagnosis of deep venous disease.