Rapid Fire Abstracts
Michael J. Randazzo, MD
Fellow
University of Chicago Medicine
Michael J. Randazzo, MD
Fellow
University of Chicago Medicine
Haonan Wang, PhD
Lead Scientist, Cardiac MR
GE Healthcare
Sherry Huang, PhD
Clinical Research Scientist
GE Healthcare
Martin A. Janich, PhD
Director, Cardiac MRI
GE HealthCare, Germany
Shuo Wang, MD, PhD
Research Associate
University of Virginia Health System
Srinath Yeshwant, MD
Assistant Professor of Medicine
University of Chicago Medicine
Luis Landeras, MD
Section Chief Cardiothoracic Imaging
The University of Chicago
U Chicago
Amit R. Patel, MD
Professor of Medicine
Division of Cardiology, University of Virginia Health System, Charlottesville, Virginia, USA.
Hena Patel, MD
Assistant Professor
University of Chicago Medicine
Vasodilator stress perfusion cardiac magnetic resonance (CMR) imaging remains limited in patients with implantable cardioverter-defibrillators (ICD) due to potential device-induced image artifacts. We aimed to assess the safety, image quality and diagnostic performance of a modified wideband stress perfusion CMR protocol in patients with ICDs.
Methods:
Consecutive patients with ICDs referred for regadenoson stress CMR were prospectively enrolled (n=7). 238 total perfusion segments were analyzed (119 at stress and 119 at rest) according to the 17-segment model. Images were acquired with a 1.5T SIGNA ARTIST MR scanner (GE HealthCare, Waukesha, WI). Perfusion images were acquired in standard short axis views of the left ventricle during stress and rest conditions with a research prototype pulse sequence based on a modified saturation recovery Spoiled Gradient Echo (SPGR) readout. To minimize artifacts induced from implants, bandwidth for saturation recovery pulse was increased to ~2500Hz, receive bandwidth 111 kHz. All other imaging parameters remained unchanged from non-ICD protocols (slice thickness 8 mm, flip angle 15°, NEX 0.75, parallel imaging factor 2, acquired matrix 192x148 pixels, FOV 38-42 cm x 29-32 cm, and TR/TE 3.1/1.5 ms). Pre- and post-contrast T1 mapping in 3 short axis views were acquired using a wideband inversion recovery SPGR modified look-locker inversion recovery (MOLLI) sequence, and T2 mapping was acquired by a multi-echo fast spin echo sequence before contrast administration. A 5-point Likert score was used to assess perceived image quality, artifact burden, and diagnostic confidence for perfusion images independently performed by two observers (Table 1).
Results:
No adverse patient- or device-related events occurred. Image quality and diagnostic confidence was graded as very good or excellent for all perfusion images (Table 2). T1 and T2 mapping was feasible in all studies (1017 ± 14 ms and 56 ± 4 ms, respectively). LGE was depicted in 57% of subjects and perfusion defects in 29% (Figure 1).
Conclusion:
Modified wideband stress perfusion CMR protocol represents a safe, promising tool for myocardial tissue characterization and ischemia detection in patients with ICDs. Adjusting bandwidth reduces device related artifacts and yields diagnostic stress perfusion images in this patient population.
