Evaluation of hemodynamic characteristics of iliac vein in chronic venous disease and iliac vein compression syndrome patients using magnetic resonance image: A prospective study

Objective

The purpose of this study was to explore the characteristics of hemodynamic parameters of iliac vein of patients with chronic venous disease (CVD) using two-dimensional (2D)-phase contrasted (PC) and four-dimensional (4D)-Flow magnetic resonance imaging (MRI) and to test the diagnostic and grading efficiency of 2D-PC and 4D-Flow MRI in CVD and iliac vein compression syndrome (IVCS).

Methods

Consecutive patients with CVD diagnosed in the outpatient department from 2023 to 2024 were enrolled in this study. Demographic data and medical records of the patients were also collected. The CEAP classification, Villalta score, and Venous Clinical Severity Score (VCSS) were used to evaluate the severity of lower limb symptoms. After computational tomography venography (CTV) scans to verify iliac vein compression, every patient underwent 2D-PC and 4D-Flow MRI scanning. Circle CVI42 software was used to perform data post processing. The inferior vena cava (IVC), common iliac vein (CIV), and common femoral vein (CFV) were chosen to acquire hemodynamic parameters by MRI. The hemodynamic parameter included flow rate (FR) per cardiac cycle, FR per minute, peak flow velocity (FV) and minimum FV measured by 2D-PC MRI and FR per cardiac cycle, peak FV and pressure gradient measured by 4D-Flow MRI. We analyzed the consistency of hemodynamic parameters between 2D-PC and 4D-Flow MRI, the differences in hemodynamic parameters between symptomatic and asymptomatic limbs and limbs with and without iliac vein compression, and the correlation between parameters and severity of symptoms.

Results

A total of 34 individuals, including three healthy volunteers, 15 patients with CVD and iliac vein compression, and 16 patients with CVD without IVCS, were enrolled in this study. Hemodynamic parameters measured by 2D-PC and 4D-Flow MRI complied with the flow rate conservation and maintained consistency (P < .01). There was a statistically significant difference in the FR of the CIV and FR difference between the CIV and CFV measured by 2D-PC and 4D-Flow MRI between symptomatic and asymptomatic limbs (2D-PC MRI: FR of CIV: 6.0 ± 3.1 vs 8.5 ± 5.1; P = .01; FR difference: 1.6 ± 2.1 vs 3.6 ± 4.3; P = .01) (4D-Flow MRI: FR of CIV: 6.9 ± 2.8 vs 8.7 ± 4.2; P = .04; FR difference: 3.0 ± 2.8 vs 4.8 ± 3.5; P = .05), and limbs with and without iliac vein compression (2D-PC MRI: FR of CIV: 5.3 ± 3.0 vs 7.6 ± 4.4; P = .03; FR difference: 1.3 ± 2.7 vs 2.8 ± 3.4; P = .04) (4D-Flow MRI FR of CIV: 6.1 ± 2.6 vs 8.2 ± 3.7; P < .01; FR difference: 2.1 ± 3.7 vs 4.6 ± 3.1; P = .04). The FR of the CIV and the FR difference between the CIV and CFV were negatively correlated with symptom severity in all affected limbs (2D-PC MRI: FR of CIV: P < .01; r = −0.3; FR difference: P = .03; r = −0.3). There was a potential negative correlation between the FR of the CIV in limbs with iliac vein compression and the severity of symptoms (2D-PC MRI: FR of CIV: P = .07; r = −0.4).

Conclusions

In conclusion, hemodynamic parameters provided by 2D-PC and 4D-Flow MRI possess the potential clinical value of evaluating CVD and iliac vein compression.