Gunhild Erstad Aandal MD, Presenter: Research funded, Siemens AG

Vidya Nadig MD, Abstract Co-Author: Nothing to Disclose

Victoria Yeh, Abstract Co-Author: Nothing to Disclose

Prabhakar Rajiah MD, FRCR, Abstract Co-Author: Nothing to Disclose

Trevor Jenkins, Abstract Co-Author: Nothing to Disclose

Abdus Sattar PhD, Abstract Co-Author: Nothing to Disclose

Mark A. Griswold PhD, Abstract Co-Author: Research support, Siemens AG Royalties, Siemens AG Royalties, General Electric Company Royalties, Bruker Corporation Contract, Siemens AG

Robert C. Gilkeson MD, Abstract Co-Author: Research consultant, Riverain Technologies, LLC Research support, Koninklijke Philips Electronics NV

Vikas Gulani MD, PhD, Abstract Co-Author: Research support, Siemens AG

Nicole Seiberlich PhD, Abstract Co-Author: Researcher, Siemens AG

To determine whether LV functional parameters and image quality of free-breathing, ungated scans reconstructed with through-time radial GRAPPA are comparable to those of gold-standard breathhold cine techniques.

Volumetric data was collected in 78 subjects (14 volunteers, 64 patients) on a 1.5T MRI scanner. Both gold-standard breathheld cardiac functional scans with ECG gating (tailored to the patient with spatial resolutions between 1.4-2.6 mm2 and temporal resolutions of 31-62ms) and free-breathing, ungated highly undersampled radial bSSFP scans (spatial resolution of 2.3mm2, temporal resolution of 42.2ms) were acquired. Reconstruction of the radial data was performed with through-time radial GRAPPA. ESV, EDV, and EF were assessed for both methods, and correlation coefficients and Bland-Altman plots were generated. The images were rated by two cardiothoracic radiologists for specific features on a scale of excellent, good, poor, no visibility; obvious visual differences precluded blinding. Ordinal logistic regression analysis (corrected for clustering) of the radiologists' ratings was performed.

Correlation coefficients indicated significant correlation between the methods (EF R=0.97, EDV R=0.99, and ESV R=0.99). Bland-Altman analysis showed that 72 of the 78 of the EF measurements were within the 95% limits of agreement (mean difference=-0.93%, SD=2.49%). Similar results were found for the EDV and ESV values. Radiologist ratings showed that the free-breathing method was preferred for depiction of endocardial borders (p<0.05), while cardiac motion and visualization of papillary muscle showed no statistical difference (p>0.05), and mitral valve visualization and blood pool contrast with the breathhold method were preferred (p<0.05).

Differences in EF, EDV, and ESV between the gold-standard and free-breathing, ungated images generated using through-time radial GRAPPA are not clinically significant. Radiologist review demonstrated that some features including endocardial borders are better visualized with the free-breathing scan due to their reduced motion artifacts, while the breathhold method was preferred for valve visualization and blood pool contrast.

Free-breathing ungated scans with through-time radial GRAPPA can be used to find LV functional parameters quickly and cost-effectively even for patients with difficulty breathholding or arrhythmia.

Aandal, G, Nadig, V, Yeh, V, Rajiah, P, Jenkins, T, Sattar, A, Griswold, M, Gilkeson, R, Gulani, V, Seiberlich, N, A Qualitative and Quantitative Assessment of Ungated Free-breathing Cardiac Imaging Using Through-time Radial GRAPPA for Left Ventricular Functional Evaluation.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13025226.html