Phase-contrast MRI evaluation of haemodynamic changes induces by a coeliac axis stenosis in the gastroduodenal artery.

OBJECTIVE: To evaluate the correlation between the gastroduodenal artery (GDA) haemodynamic changes and the degree of coeliac axis (CA) stenosis using phase-contrast MRI.

METHODS: The study was institutional review board approved, and written informed consent was obtained from patients included prospectively. A two-dimensional phase-contrast MRI was performed in 23 patients scheduled for a potential complex supramesocolic surgery, in a plane perpendicular to the GDA, during inspiration and expiration. The peak and mean velocities (Vp and Vm ), mean flow rate (Qm ) and flow direction at inspiration and at expiration have been correlated with the degree of CA stenosis evaluated by CT.

RESULTS: 13 of 23 patients presented CA stenosis due to the median arcuate ligament (34-80% of stenosis), 4 of them had associated atheromatous calcifications. Vp , Vm and Qm of GDA presented a significant and linear relationship with the degree of CA stenosis, at inspiration as well as at expiration (r > 0.74, p < 0.001). Velocities and flow rates presented a different pattern depending on the degree of CA stenosis: <34% (n = 10), flow direction remained physiological with low velocities and flow rates; >60% of stenosis (n = 5), a reverse flow direction with increased velocities and flow rates were observed; variable patterns between 34% and 60%.

CONCLUSION: Phase-contrast MRI permits the evaluation of haemodynamic changes in GDA induced by CA stenosis, including median arcuate ligament compression, and could be of great interest in therapeutic decision making in supramesocolic surgery, such as liver transplantation or duodenopancreatectomy, by detecting haemodynamically significant stenoses. Advances in knowledge: Physiological phase-contrast MRI detects haemodynamically significant stenoses of the CA by evaluating haemodynamic parameters in the GDA. Physiological phase-contrast MRI demonstrates that flow in the GDA can be a direct marker of the real haemodynamic impact of a CA stenosis on the hepatic vascularization and could thus participate in the pre-surgical work-up of duodenopancreatectomy or hepatic graft, whereas existing pre-operative imaging are only morphological.