Anderanik Tomasian MD, Presenter: Nothing to Disclose

Aparna Singhal MBBS, Abstract Co-Author: Nothing to Disclose

Sachin Malik BS, Abstract Co-Author: Nothing to Disclose

Stefan Georg Ruehm MD, Abstract Co-Author: Nothing to Disclose

J. Paul Finn MD, Abstract Co-Author: Research Consultant, Siemens AG Speakers Bureau, Bayer AG

Mayil S. Krishnam MBBS, Abstract Co-Author: Nothing to Disclose

To study the feasibility of non-contrast 3D SSFP MRA for evaluation of thoracic aortic diseases and to correlate the results with high resolution contrast-enhanced MRA (CE-MRA)

45 consecutive patients with known or suspected thoracic aortic diseases underwent free breathing ECG-gated non-contrast SSFP MRA with non-selective radiofrequency excitation and conventional CEMRA of thorax at 1.5 T(Avanto, Siemens). Two readers evaluated both datasets for vessel visibility and sharpness (3-point scale), artifacts, findings, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in aortic segments including aortic annulus, sinus, sino-tubular junction, ascending aorta, aortic arch, descending aorta and origin of supraaortic arteries. Statistical analysis was performed with Wilcoxon and T tests, and k co-efficient. DSA and CTA were available for comparison in 5 and 6 patients, respectively.   

Mean scan time for SSFP MRA was 7 ± 2 minutes. Reader 1 and 2 assigned excellent or diagnostic definition for 399 (98.5%) and 401 (99%) segments on SSFP MRA (k=0.79), and for 365 (90.1%) and 368 (90.9%) segments on CEMRA (k=0.73), respectively (). Reader 1(2) noted mild motion artifact on SSFP and CE-MRA in 22(20) and 78(82) segments, respectively. Aortic pathologies seen in both datasets were aortic root dilatation (n=18), ascending aortic aneurysm (n=17), arch aneurysm (n=3) and descending aortic aneurysm (n=5), coarctation (n=5), dissection (n=2), and mural thrombus (n=2). Segmental visibility was higher for aortic annulus, sinus, and sino-tubular junction on SSFP MRA (P<0.01), and no significant difference existed for visibility scores of aorta (ascending, arch, and descending) or the arterial origins between the two datasets (P>0.05 for all). SNR values were significantly higher on SSFP MRA for all segments (P<0.01). Findings were confirmed on DSA and CTA in 5 and 6 patients, respectively. Sensitivity, specificity, and accuracy of SFPA MRA for detection of aortic pathologies were 100% considering CE-MRA as the reference standard.

Non-contrast free breathing 3D SSFP MRA is a reliable alternative technique to evaluate thoracic aortic pathologies.   

3D non-contrast SSFP MRA may obviate the need of intravenous gadolinium in patients who are at risk of developing contrast related complications such as nephrogenic systemic fibrosis.   

Tomasian, A, Singhal, A, Malik, S, Ruehm, S, Finn, J, Krishnam, M, Thoracic Aortic Diseases: Head-to-head Comparison between Noncontrast 3D SSFP MR Angiography and Conventional Contrast Enhanced MRA.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6013166.html