Matthias Renker MD, Abstract Co-Author: Nothing to Disclose

Akos Varga-Szemes MD, PhD, Presenter: Nothing to Disclose

Carlo Nicola de Cecco MD, Abstract Co-Author: Nothing to Disclose

Stefan Baumann MD, Abstract Co-Author: Nothing to Disclose

Edgar Muller, Abstract Co-Author: Employee, Siemens AG

U. Joseph Schoepf MD, Abstract Co-Author: Research Grant, Bracco Group Research Grant, Bayer AG Research Grant, General Electric Company Research Grant, Siemens AG

Davide Piccini, Abstract Co-Author: Employee, Siemens AG

Wolfgang Rehwald, Abstract Co-Author: Employee, Siemens AG

Daniel H. Steinberg MD, Abstract Co-Author: Nothing to Disclose

Because of the high comorbidity of TAVR candidates, a rapid, robust, non-contrast MR technique for assessing the aortic root complex along with the entire vascular access route would be desirable for TAVR procedural planning. We tested a newly developed non-contrast, free-breathing, self-navigated 3D (SN3D) MR sequence for assessing the entire aorta, from the root to the ilio-femoral run-off. A non-contrast steady-state free-precession (SSFP) sequence which has previously been shown to enable accurate aortic valve assessment was used for comparison.

We performed non-contrast MR angiography on a 1.5T system (Avanto, Siemens) using the novel SN3D and the SSFP sequence in 6 healthy subjects. The SN3D sequence was applied to assess the aorta from its root to the ilio-femoral arteries. The parameters for the SN3D acquisitions were: FOV 220/370mm, ST 1.15mm, IM 1922, slices 192, TR 265.2ms, TE 1.5ms, and FA 90°. Both the thoracic and abdominal acquisitions were ECG gated. The parameters for the SSFP sequence were: FOV 340mm, ST 6mm, IM 1922, NS 15, reconstructed phases 25, TR 39.7ms, TE 1.1ms, FA 77°, averages 3, acceleration factor 2. With SSFP only the thoracic acquisitions were ECG gated. Systolic aortic root measurements and subjective image quality (5-point scale) were compared. Vessel diameter and area measurements down to the level of the ilio-femoral arteries were obtained from the SN3D dataset. Acquisition times were recorded.

The mean area-derived effective diameter in the aortic annular plane was comparable between SSFP and SN3D (26.7±0.7mm vs. 26.1±0.9mm, P=0.23). Median image quality of the aortic valve was rated slightly (p=0.03) higher with SSFP (4 - interquartile ranges, IQR; 4-4) than with SN3D (3 - IQR, 2-4).  No significant differences were observed between the diameter and area of the thoracic and abdominal aorta, and the ileo-femoral run-off (p>0.05). The acquisition time of the SN3D sequence for the whole aorta was 12.1±2.7min.

These preliminary results in healthy volunteers suggest that the proposed SN3D acquisition technique enables rapid, free-breathing assessment of the aortic root, the aorta and the ilio-femoral arteries without the administration of contrast medium.

The features of the proposed SN3D sequence appear well suited to address the requirements for TAVR procedural planning in a population which frequently suffers from renal insufficiency and dyspnea.

Renker, M, Varga-Szemes, A, de Cecco, C, Baumann, S, Muller, E, Schoepf, U, Piccini, D, Rehwald, W, Steinberg, D, A Non-Contrast, Free-Breathing, Self-Navigated MR Technique for Aortic Root and Vascular Access Route Assessment in the Context of Transcatheter Aortic Valve Replacement.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007154.html