Skip to content

Advertisement

  • Oral presentation
  • Open Access

3 T cardiac magnetic resonance performs well as the primary scanner in a clinical setting: our initial experience at a tertiary care center

  • 1,
  • 1,
  • 1,
  • 1,
  • 1,
  • 2,
  • 1 and
  • 1
Journal of Cardiovascular Magnetic Resonance200911 (Suppl 1) :O101

https://doi.org/10.1186/1532-429X-11-S1-O101

  • Published:

Keywords

  • Excellent Image Quality
  • Parallel Imaging Technique
  • Banding Artifact
  • Cine SSFP
  • High Acceleration Factor

Introduction

Despite the advantage of increased signal-noise-ratio, skepticism exists regarding the use of 3 T as the primary scanner for routine clinical CMR examination due to potential for gating difficulties related to the increased magnetohydrodynamic effect, off-resonance artifacts, and patient heating. We quantified the diagnostic potential and artifacts based on our experience of the first 4 months of routine clinical 3 T CMR exams in a tertiary clinical center.

Purpose

To test the hypothesis that 3 T MRI is practical in serving a busy clinical CMR service as the primary routine cardiac scanner.

Methods

Two-hundred and eighty patients were referred for CMR for a broad range of clinical indications over a 4-month period and underwent a 3 T cardiac MRI scan (MAGNETOM Tim Trio, Siemens, Germany). Three experienced readers quantified total scan time, troubleshooting time for 3 T-related off-resonance artifacts, image quality, and artifacts in all pulse sequences performed. Image quality was graded per accepted criteria (1-Non diagnostic, 2-diagnosis suspected but not established with severe blurring, 3-definite diagnosis despite moderate blurring, 4-definite diagnosis with only mild blurring, 5-definite diagnosis without visible blurring). Artifacts severity was graded in a 5-point scale (1-No artifacts, 2-minimal artifacts, good diagnostic quality images, 3-moderate artifact and diagnosis established, 4-considerable artifacts, diagnosis suspected but not established, 5 – severe artifacts, non diagnostic images). Excellent image quality was classified as a score ≥ 4 and minimal or no artifact was classified as an artifact score of ≤ 2. Forty-six 1.5 T CMR studies performed at the same study period with a matched spread of indications were randomly selected as a control group for comparison.

Results

On average, 2.8 minutes (5% of total scan time) were spent to eliminate off-resonance banding artifacts in 3 T. This time is made up by more aggressive accelerated parallel imaging technique. As a result, average total scan time using 3 T was not different from 1.5 T (54 ± 14 vs. 54 ± 12 minutes, P = 0.47). No patients failed to complete the study due to SAR limit. There were no complications during any of the 1.5 T or 3 T CMR studies. A significantly higher proportion of perfusion images were graded as being of excellent quality on 3 T when compared to 1.5 T (82.4% vs. 41.4%, p < 0.0001) (Figure 1). A significantly higher number of perfusion images also had minimal or no artifact on 3 T when compared to 1.5 T (93.7% vs. 72.4%, p = 0.0016). When LGE images were analyzed, a significantly higher proportion of images on 3 T were graded as being excellent (82.6% vs. 46.2%, p < 0.0001) and the proportion of LGE images having minimal or no artifact was also significantly higher on 3 T (83.0% vs. 56.4%, p = 0.0042). The number of Cine SSFP, pulmonary vein MRA, and phase contrast images that were graded as being of excellent quality or with no or minimal artifact did not differ between 3 T and 1.5 T.
Figure 1
Figure 1

Excellent image quality achieved (grade 4 or 5).

Conclusion

3 T cardiac MRI performs well serving as the primary scanner in a busy CMR service with comparable scan times to 1.5 T cardiac MRI. 3 T has improved image quality and fewer artifacts especially for applications like perfusion and LGE which benefit from the increase in T1 times at 3 T. The high SNR leaves additional room to also decrease the overall scan time in the future using higher acceleration factors for parallel imaging techniques without sacrificing diagnostic image quality.

Authors’ Affiliations

(1)
Brigham and Women's Hospital, Boston, MA, USA
(2)
Siemens Medical Solutions, Chicago, IL, USA

Copyright

© Rajaram et al; licensee BioMed Central Ltd. 2009

This article is published under license to BioMed Central Ltd.

Advertisement