Quantitative 4D-Flow MR Imaging of Abdominopelvic Vasculature in Pelvic Venous Disorder.

Purpose: To determine whether quantitative 4-Dimensional (4D)-Flow MRI could reflect morphologic findings of pelvic venous disorder (PeVD).

Materials And Methods: Abdominopelvic MRI with 4D-Flow acquired with 3T MRI from 2016-2022 were retrospectively reviewed for morphologic imaging findings: no venous abnormalities (NVA), left common iliac vein compression, left gonadal vein reflux, left renal vein (LRV) compression, and presence of pelvic collaterals. Using 4D-Flow MRI, blood flow was measured for vascular segments from the level of the suprarenal inferior vena cava (IVC) to the common iliac veins. Flow measurements at the LCIV and right common iliac vein (RCIV), the perihilar and juxta-caval renal veins were compared among participants with NVA, LCIV compression, LRV compression with and without LGV reflux, and with LGV reflux without LRV compression.

Results: Sixty-six participants with LCIV compression, LRV compression, or LGV reflux displayed significantly diminished flow adjacent to the site of compression or reflux. Compared to participants with NVA, those with LCIV compression with pelvic collaterals showed increased RCIV flow and decreased LCIV flow (LCIV:RCIV flow ratio: 0.49±0.08 vs. NVA:0.92±0.05, p=0.0005). LCIV compression without pelvic collaterals did not significantly differ from NVA (LCIV:RCIV flow ratio: 0.80±0.09 vs. NVA, p>0.1). LRV compression with LGV reflux showed diminished juxta-caval LRV flow and similar perihilar LRV flow compared to LRV compression without LGV reflux ( p=0.03) or NVA (p=0.004) (juxta-caval:perihilar LRV flow ratio: with LGV reflux:0.39±0.17, without LGV reflux:1.3±0.19, NVA:1.3±0.13).

Conclusions: Quantitative abdominopelvic 4D-Flow MRI measurements reflected flow diversion away from obstruction in LCIV or LRV compression, particularly in the setting of decompressing venous reservoirs.