Multi-Velocity Encoding Four-Dimensional Flow Magnetic Resonance Imaging in the Assessment of Chronic Aortic Dissection

AORTA

article

Andrew G. Sherrah¹  Fraser M. Callaghan³  Rajesh Puranik¹  Richmond W. Jeremy¹  Paul G. Bannon¹  Michael P. Vallely¹  Stuart M. Grieve¹ 

[1] Sydney Medical School, University of Sydney;The Baird Institute for Applied Heart and Lung Surgical Research;Sydney Translational Imaging Laboratory, University of Sydney;Cardiovascular Magnetic Resonance Sydney;Institute of Academic Surgery, University of Sydney;Heart Research Institute, University of Sydney;Department of Radiology, Royal Prince Alfred Hospital

关键词: Aorta;    Thoracic;    Aortic dissection;    Magnetic resonance imaging;   

DOI  :  10.12945/j.aorta.2017.16.046

来源: Thieme

【 摘 要 】

Background: Chronic descending thoracic aortic dissection (CDTAD) following surgical repair of ascending aortic dissection requires long-term imaging surveillance. We investigated four-dimensional (4D)-flow magnetic resonance imaging (MRI) with a novel multi-velocity encoding (multi-VENC) technique as an emerging clinical method enabling the dynamic quantification of blood volume and velocity throughout the cardiac cycle. Methods: Patients with CDTAD (n = 10; mean age, 55.1 years; standard deviation (SD) 10.8) and healthy volunteers (n = 9; mean age, 37.1 years; SD 11.4; p < 0.01) underwent 3T MRI, and standard views and 4D-flow data were obtained. Flow measurements were made in selected regions of interest within the ascending and descending thoracic aorta. Results: The overall flow profile at peak systole was reduced in the false lumen (FL) compared with the true lumen (TL) and normal aortas (p < 0.05 for velocity < 0.4 m/s). Peak systolic flow rate per aortic lumen area (mL/s/cm2) was lower in the FL than in the TL (p < 0.05), and both rates were lower than that of control aortas (p < 0.05). Blood flow reversal was higher in the FL than in the TL throughout the descending aorta in CDTAD patients (p < 0.05). A derived pulsatility index was elevated in the TL compared with that in the FL in CDTAD patients. Generated pathline images demonstrated flow patterns in detail, including sites of communication between the true and FL. Conclusions: 4D-flow MRI revealed FL blood flow and reduced blood flow velocity and flow rate in the TL of CDTAD patients compared with normal aortas of healthy participants. Thus, multi-VENC 4D-flow MRI could serve as an adjunct in the long-term assessment of CDTAD following surgical repair of ascending aortic dissection.

【 授权许可】

Unknown