Comparison of intravascular ultrasound and magnetic resonance venography in the diagnosis of chronic iliac venous disease.

Background: The diagnosis of chronic iliofemoral venous obstruction (CIVO) can be made with several different modalities. Intravascular ultrasound (IVUS) examination is the gold standard in the diagnosis of CIVO. However, being invasive, it should not be the initial examination to screen patients with CIVO. The aim of this report is to compare the performance of magnetic resonance venography (MRV) with IVUS examination in the diagnosis of CIVO.

Methods: From January 2016 to December 2020, the records of all patients who underwent preoperative MRV and then IVUS in the evaluation of CIVO were analyzed retrospectively.

Results: There were 505 patients who were evaluated by any modality for CIVO. Of these patients, 15% (78) were evaluated by MRV. Patients who had failed a trial of conservative therapy for at least 3 to 6 months and who had disabling and lifestyle-limiting symptoms of CIVO were selected to undergo further evaluation with MRV at the treating physician's discretion. For inclusion in analysis, technically satisfactory IVUS examination and MRV data were mandatory. Data was available for 60 common iliac vein (CIV) segments and 61 external iliac vein (EIV) segments for comparative analysis after appropriate exclusions. The mean age of the patients was 56 ± 15 years. The male to female ratio was 1:2. The distribution of patients across different CEAP classes was as follows: CEAP 3, 28%; CEAP 4, 62%; CEAP 5, 2%; and CEAP 6, 8%. Bland-Altman plots of the mean difference in area between IVUS examination and MRI were 74.1% for CIV and 56.9% for EIV. The sensitivity of MRV was 93% and 100%, and the specificity was 0% and 50% for CIV and EIV, respectively. The positive predictive value was 93% and 86%; the negative predictive value was 0 and 50% for CIV and EIV, respectively. Improvement was noted in clinical parameters (Venous Clinical Severity Score, visual analog pain scale, and grade of swelling) after IVUS examination and stenting after MRV. For the Venous Clinical Severity Score, the score improved from 6.0 ± 2.7 (before the procedure) to 4 ± 2.7 (after the procedure) (P = .0001).

Conclusions: There is dimensional disparity between MRV and IVUS examination in the diagnosis of symptomatic CIVO. MRV has a high sensitivity but low specificity when compared with IVUS examination and overestimates the severity of the stenosis in both the EIV and CIV. MRV is not a reliable diagnostic tool for iliac vein stenosis and should not be used for the definitive disposition of patients with CIVO.