Florian Matthias Vogt MD, Presenter: Nothing to Disclose

Holger Eggebrecht MD, PhD, Abstract Co-Author: Nothing to Disclose

Gerhard A. Laub PhD, Abstract Co-Author: Employee, Siemens AG

Stefan Maderwald MSc, Abstract Co-Author: Nothing to Disclose

Randall Kroeker PhD, Abstract Co-Author: Nothing to Disclose

Joerg Barkhausen MD, Abstract Co-Author: Research Consultant, Bayer AG

To evaluate the image quality and the diagnostic accuracy of a new time-resolved 3D MR angiography technique (TWIST) combining high spatial and temporal resolution for the pre-interventional assessment of aortic dissection.

Twenty patients with acute dissection of the descending thoracic and/or abdominal aorta underwent time-resolved 3D MR-angiography. Following automatic injection of 5 ml Gadovist at 3ml/sec, 15 consecutive coronal T1w 3D datasets (TR/TE 2.8/1.2 ms; FA 25°; slices 64;matrix 231 x 320; spatial resolution 1.9 x 1.6 x 2.1 mm³, true temporal resolution 3.3 s) were acquired using the TWIST sequence with parallel imaging technique (Grappa). After a short pause, a conventional high spatial resolution MRA (0.1 mmol/kg) was acquired (breath hold 25 s) using a 3D spoiled gradient-echo sequence (TR/TE 3/0.97 ms, FA 25°, slices 72,matrix 289 x 384; voxel size 1.4 x 1.3 x 1.8 mm³). Both MR data sets were evaluated and compared for image quality and visualization of vascular details. A radiologist and an interventional cardiologist assessed the additional diagnostic information of the TWIST concerning contrast enhancement and tissue perfusion.

TWIST-MRA characterized true and false lumen as well as the origin of the branch vessels correctly in all patients. The temporal resolution of the TWIST-MRA allowed visualizing the transit of the contrast agent bolus within the true and the false lumen and provided additional information compared to the static MRA in 7/20 patients. These finding had impact on therapy planning and the combined morphologic and dynamic imaging of the TWIST MRA provided reliable information for successful planning of endovascular stentgraft repair in all patients. Due to the dynamic character of the TWIST sequence no venous overlay hampered the assessment of the arterial system.

TWIST-MRA is a robust technique combining functional and morphological information. TWIST-MRA provides all information for treatment planning in patients suffering from acute aortic dissection.

TWIST-MRA combining high spatial and temporal resolution provides all information for treatment planning in patients suffering from acute aortic dissection.

Vogt, F, Eggebrecht, H, Laub, G, Maderwald, S, Kroeker, R, Barkhausen, J, High Spatial and Temporal Resolution MRA (TWIST) in Acute Aortic Dissection.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5010415.html