Daniel Theisen MD, Presenter: Nothing to Disclose

Armin Michael Huber MD, Abstract Co-Author: Nothing to Disclose

Olaf Dietrich, Abstract Co-Author: Nothing to Disclose

Thorsten R.C. Johnson MD, Abstract Co-Author: Speakers Bureau, Siemens AG

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Bernd J. Wintersperger MD, Abstract Co-Author: Nothing to Disclose

To investigate the benefit of 3 T field strength in myocardial first-pass perfusion imaging in regard to signal parameters and semi-quantitative perfusion parameters in comparison to 1.5 Tesla based on an intraindividual comparison.

In 16 volunteers, myocardial first-pass perfusion imaging was performed at 1.5 Tesla (Magnetom Avanto) and 3 Tesla (Magnetom TIM Trio) after injection of 0.05mmol/kg body weight Gadobutrol using an accelerated saturation recovery multislice TurboFLASH technique (GRAPPA;R=2). Detailed sequence parameters (TR 2.3ms, TE 0.93 ms, FA 15°, BW 780 Hz/px) as well as spatial resolution were kept identical for both field-strengths. Artifacts were assessed quantitatively and qualitatively, signal-to-noise ratio (SNR) and contrast enhancement ratio (CER) were calculated from raw data signal-intensity (SI)-time curves. Semi-quantitative perfusion analysis was performed using a linear fit on the upslope of the SI-time curves.

Maximum SNR was significantly higher at 3 T than at 1.5 T (35.7±11.9 vs. 18.0±5.5, P<0.001). Also CER was significantly higher at 3 T (2.2±0.9) than at 1.5 T (1.5±0.5, P<0.001). The evaluated maximum upslope at 3T (3.3±2.4), a semi-quantitative measure of perfusion also showed a significant increase compared to 1.5 T (2.0±1.0, p<0.001). The assessment of artefacts did not reveal any significant differences between 1.5 T and 3 T field strength.

3 T significantly improves CER and SNR when compared to 1.5 T using identical acquisition parameters. In addition, the most important semi-quantitative perfusion parameter, maximum upslope, is significantly increased. This benefit in SI parameters may allow for improvement of spatial resolution and application of higher acceleration factors to reduce the acquisition window.

MR myocardial perfusion imaging substantially benefits from 3T in regard to SI and perfusion parameters. Thus, higher acceleration factors may be applied to increase spatial resolution without widening of the acquisition window.

Theisen, D, Huber, A, Dietrich, O, Johnson, T, Reiser, M, Wintersperger, B, Myocardial Perfusion Imaging with Gadobutrol: A Comparison between 3 and 1.5 Tesla with Identical Sequence Parameters.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5007560.html