Bernhard Klumpp MD, Presenter: Nothing to Disclose

Achim Seeger, Abstract Co-Author: Nothing to Disclose

Michael Christian Fenchel MD, Abstract Co-Author: Nothing to Disclose

Ulrich Kramer MD, Abstract Co-Author: Nothing to Disclose

Claus Detlef Claussen MD, Abstract Co-Author: Nothing to Disclose

Stephan Miller MD, Abstract Co-Author: Nothing to Disclose

High resolution magnetic resonance angiography (MRA) is preferably enabled by parallel image acquisition. The consecutive signal loss could be compensated for by increased field strength. Aim of our study was the intraindividual comparison of thoracoabdominal MRA at 1.5T and 3T.

MRA was performed in 20 patients at 1.5T and 3T in randomized order. After resting myocardial perfusion (2D tfl, 0.05 mmol gadobenate-dimeglumine/kg bw (Multihance, Bracco-Altana, Konstanz)) high resolution MRA sequences were performed (FLASH 3D 1.5T/3T: TE 1.1/1.2, TR 3.1/3.3, voxel size 1.6x1.0x1.5/1.0x1.0x1.2 mm, flip 25°/23°, matrix 230x512/320x384, grappa 2/3, 0.05 mmol gadobenate-dimeglumine/kg bw, 2ml/s). Image quality was rated by two independent observers on a four-point scale (score 0-3). Region-to-region analysis of relative signal intensities of the thoracic vasculature and skeletal muscle was performed.

Diagnostic image quality was achieved in all patients at both systems (1.5T/3T: 2.1±0.5/2.4±0.5, p=0.06) with high image contrast of the whole field of view. Relative signal intensities of the aorta/skeletal muscle were pre and postcontrast 2.4±0.5/8.3±2.7 at 1.5T and 2.7±0.7/10.4±3.3 at 3T (p>0.05/p<0.05) with image contrast ratios of 5.9±2.5 at 1.5T and 7.7±2.8 at 3T (p<0.05). Despite higher spatial resolution and consecutive necessity of higher acceleration factors MRA at 3T provided significantly higher signal intensities and image contrast. Stenoses were newly diagnosed in two patients.

3T provides for MRA significantly increased image quality and signal intensity even at higher spatial resolution using higher acceleration factors. These advantages might be exploited for further increased spatial resolution or for the reduction of acquisition times beneficial in patient with limited breath hold capability.

MRA at 3T provides significantly increased image quality and signal intensity even at higher spatial resolution using higher acceleration factors compared to 1.5T.

Klumpp, B, Seeger, A, Fenchel, M, Kramer, U, Claussen, C, Miller, S, High Resolution Thoracic MRA Using Parallel Image Acquisition at 1.5T and at 3T.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5006737.html