Email updates

Keep up to date with the latest news and content from Journal of Cardiovascular MR and BioMed Central.

This article is part of the supplement: Abstracts of the 2011 SCMR/Euro CMR Joint Scientific Sessions

Open Access Poster presentation

Single breath-hold non-contrast thoracic mra using highly-accelerated parallel imaging with a 32-element coil array

Jian Xu1*, Kellyanne Mcgorty2, Ruth Lim2, Mary Bruno2, Monvadi Srichai2, Daniel Kim2 and Daniel K Sodickson2

  • * Corresponding author: Jian Xu

Author Affiliations

1 Polytechnic Institute of New York University and Siemens Medical Solutions USA inc., New York, NY, USA

2 Radiology of New York University, New York, NY, USA

For all author emails, please log on.

Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):P374  doi:10.1186/1532-429X-13-S1-P374


The electronic version of this article is the complete one and can be found online at: http://jcmr-online.com/content/13/S1/P374


Published:2 February 2011

© 2011 Xu et al; licensee BioMed Central Ltd.

This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Purpose

To evaluate the feasibility of performing non-contrast thoracic MRA with isotropic spatial resolution within a single breath-hold.

Background

Contrast-enhanced 3D magnetic resonance angiography (CE-MRA) provides accurate diagnosis of aortic disease [1-4]. ECG-gated CE-MRA of the thoracic aorta is challenging, due to competing demands of high spatial resolution while imaging in a narrow window of the cardiac cycle within a breath-hold. In addition, nephrogenic systemic fibrosis in patients with impaired renal function is a concern with gadolinium-based contrast agents [5]. Non-contrast ECG-gated MRA (NC-MRA) is a potential alternative [6], especially for patients with poor intravenous access or contraindications to gadolinium use. Navigator-gated NC-MRA can take approximately 10 minutes [6]. We propose to perform breath-hold, ECG-gated NC-MRA (BH NC-MRA) using highly-accelerated parallel imaging with a 32-element coil array.

Methods

Following informed consent, 10 subjects (7 controls, 3 patients; 6 male, mean age=35.1 ±17.0 years) were imaged on a 1.5T scanner (Siemens, Avanto) with BH NC-MRA followed by CE-MRA. Imaging parameters for BH NC-MRA using balanced steady state free precession (b-SSFP) with T2 and fat-suppression preparation pulses were: TR/TE 2.3/1.6ms, FA70°, FOV 400x400x64mm, voxel size 1.6x1.6x1.6mm3, 2D GRAPPA acceleration of 3x2, segments 48, 6/8 partial Fourier in both phase encode and partition directions, partition oversampling 20%,mean scan time 19.4±4.1s. Both coil sensitivity (early systole) and MRA (mid diastole) data were acquired in the same breath hold (Figure 1). Pre- and post-contrast ECG-gated CE-MRA used similar parameters to achieve matched spatial resolution, TR/TE 3.6/1.1ms,,FA 17°,BW 330Hz/pixel,1D GRAPPA acceleration factor 2, mean scan time 39.4±10.5s. Gd-DTPA 0.15 mmol/kg at 2cc/sec was administered with arterial timing based on a timing bolus. Source and subtracted images (for CE-MRA) were reviewed in blinded fashion by a cardiologist and a radiologist. Image quality was scored (0-4; non-diagnostic to excellent) for 4 aortic segments (Table 1). Severity of artifacts was also evaluated (0-4; none to high).

thumbnailFigure 1. Single BH NC-MRA with the coil sensitivity and image data acquired at two different cardiac phases in the same cardiac cycle.

Table 1. Comparison of image-quality and overall artifact scores between CE-MRA and NC-MRA

Results

Figure 2 shows representative CE-MRA and BH NC-MRA images. For the 10 subjects studied, there was no significant difference in image quality and artifact scores (p>0.05), with diagnostic quality image scores for all evaluated segments (Table1).

thumbnailFigure 2. Multi planar reconstruction of A) contrast-enhanced MRA and B) noncontract enhanced MRA in a patient (59yr, Female) with aneurysm of the aortic root.

Conclusions

This study demonstrates the feasibility of performing highly accelerated single BH NC-MRA with isotropic spatial resolution and diagnostic image quality. It has potential benefits of short scan time and repeatability without need for exogenous contrast, providing rapid, safe, entirely non-invasive assessment of the thoracic aorta

References

  1. Gebker R, et al.:

    Int J Cardiovasc Imaging. 2007, 23(6):747-756. PubMed Abstract | Publisher Full Text OpenURL

  2. Groves EM, et al.:

    Am J Roentgenol. 2007, 188(2):522-528. Publisher Full Text OpenURL

  3. Prince MR, et al.:

    Am J Roentgenol. 1996, 166:1387-1397. OpenURL

  4. Krinsky GA, et al.:

    Am H Roentgenol. 1999, 173:145-150. OpenURL

  5. Kanal E, et al.:

    Radiology. 2008, 246(1):11-14. PubMed Abstract | Publisher Full Text OpenURL

  6. Srichai MB, et al.:

    Tex Heart Inst J. 2010, 37(1):58-65. PubMed Abstract | PubMed Central Full Text OpenURL