Peter Hunold MD, Presenter: Speaker, Bayer AG

Dariusz Michna, Abstract Co-Author: Nothing to Disclose

Ulrich Neudorf, Abstract Co-Author: Nothing to Disclose

Jens Matthias Theysohn MD, Abstract Co-Author: Nothing to Disclose

Florian M. Vogt, Abstract Co-Author: Speaker, Bayer AG

Harald H. Quick PhD, Abstract Co-Author: Nothing to Disclose

Aim of the present study was to evaluate time-resolved contrast-enhanced 4D MR angiography compared to 3D FLASH-MRA regarding image quality and added diagnostic value in congenital heart and vessel anomalies.

Twenty-six pts (age, 26±16 yrs; range, 9-70 yrs) with suspected or known congenital heart and vessel anomalies were included: aortic coarctation, n=8; TGA, 6; TOF, 4; Ebstein´s anomaly, 2; pulmonary valve stenosis, 2; others, 4. All pts underwent contrast-enhanced MRA at 1.5T (Magnetom Avanto, Siemens) with both 3D FLASH (TR/TE, 3.14/1.05ms; FA, 25°; PAT factor, 2; 96 slices; resolution, 1.2x1.0x1.5mm³; acq. time per 3D data set, 21s) and 4D TWIST MRA (TR/TE, 2.66/1.07ms; FA, 25°; PAT factor, 3; 88 slices; resolution, 1.3x1.0x1.5mm³; acq. time per 3D data set, 4.1s) in coronal orientation. Images of both sequences were subjectively evaluated by two investigators on a 5-point scale regarding 1) total image quality, 2) artefacts, 3) diagnostic value, 4) added diagnostic value of 4D dynamic in main diagnosis, 5) additional information through 4D dynamic, and 6) added level-of-confidence through 4D. Quantitative comparison included SNR, CNR, and vessel wall delineation.

3D FLASH MRA required 10.8±5cc of gadobutrol, whereas 4D TWIST was run with 5cc constantly. Concerning the subjective parameters, the 3D FLASH MRA was judged slightly but significantly better in terms of image quality (4.0±0.5 vs. 3.5±0.5, p<0.05) and artefacts (3.8±0.4 vs. 3.3±0.5, p<0.05) No difference in diagnostic value was found (4.2±0.4 vs. 4.0±0.4). There was no added diagnostic value through the 4D dynamic regarding main diagnosis, additional information, or level-of-confidence. SNR and CNR were higher in the pulmonary trunc in 4D TWIST, but slightly higher in the systemic arteries in 3D FLASH, and significantly higher in the great veins in 3D FLASH. No difference in vessel wall delineation was found.

Contrast-enhanced time-resolved 4D TWIST MRA yields robust images with high SNR and CNR and less Gd contrast material in congenital heart and vessel anomalies. However, no added diagnostic value through the dynamic acquisition was found compared to 3D FLASH MRA.

Contrast-enhanced 4D TWIST MRA may be used in pts with relative contraindications to Gd yielding comparable image quality. Image acquisition by 4D TWIST is easier because no timing difficulties occur.

Hunold, P, Michna, D, Neudorf, U, Theysohn, J, Vogt, F, Quick, H, Contrast-enhanced MR Angiography of Congenital Heart and Vessel Anomalies: Image Quality and Diagnostic Value of Time-resolved 4D TWIST-MRA vs 3D FLASH-MRA.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034640.html