Download The following text provides a full description of the CMR/echo

Online Appendix for the following August 1 iJACC article
TITLE:
Contrast-Enhanced
Anatomic
Imaging
as
Compared
With
Contrast-Enhanced
Tissue
Characterization for Detection of Left Ventricular Thrombus
AUTHORS: Jonathan W. Weinsaft, MD, Raymond J. Kim, MD, Michael Ross, MD, Daniel Krauser, MD,
Shant Manoushagian, BA, Troy M. LaBounty, MD, Matthew D. Cham, MD, James K. Min, MD, Kirsten
Healy, MD, Yi Wang, PHD, Michele Parker, MS, RN, Mary J. Roman, MD, Richard B. Devereux, MD
APPENDIX
The following is a full description of the CMR and echo imaging protocols.
Imaging Protocol
Cardiac Magnetic Resonance
CMR imaging was performed by dedicated technologists using 1.5 Tesla scanners (General Electric
Signa) with dedicated phased array surface coils. CMR consisted of two components: (1) cine-CMR for
anatomical/ functional assessment and (2) DE-CMR for tissue characterization. In accordance with
institutional standards, CMR was initially performed without consideration of renal function. Beginning in
December 2006, as a result of a prior United States Food and Drug Administration warning concerning the
risks of gadolinium-induced nephrogenic systemic fibrosis in patients with renal dysfunction,6 patients were
screened for renal dysfunction and those with glomerular filtration rate < 30 ml/min/1.73m2 were excluded
from study participation.
Cine-CMR was performed using a steady-state free procession sequence (typical parameters: repetition
time (TR) 3.5 msec, echo time (TE) 1.6 msec, flip angle 60°, in-plane spatial resolution 1.9 mm x 1.4 mm).
Following cine-CMR, gadolinium was intravenously administered (0.2 mmol/kg). DE-CMR was initiated 10
minutes thereafter using a segmented inversion recovery sequence.7 Cine-CMR and DE-CMR images were
obtained in matching short- and long-axis planes. Short-axis images were acquired throughout the LV (6-mm
slice thickness, 4-mm gap) from the level of the mitral valve annulus through the apex. Long-axis images
were acquired in standard two-, three-, and four-chamber orientations. Imaging time was 13:03±5:54
minutes for cine-CMR and, following the 10 minute interval between contrast administration and resumption
of imaging, 19:06±5:29 minutes for DE-CMR (p=0.06), including time between breath-holds.
Echocardiography
Transthoracic 2D-echocardiograms were performed by experienced sonographers who had undergone
dedicated in-service training regarding the imaging protocol. Echoes were performed using commercially
available equipment (General Electric Vivid-7 or Siemens Sequoia). Non-contrast images were acquired in
standard parasternal long- and short-axis and apical 2-, 3-, and 4- chamber imaging planes in accordance
with American Society of Echocardiography guidelines.5 A sonographic contrast agent (Definity [Lantheus
Medical Imaging]; perflutren lipid microspheres) was then administered as 3 ml of a diluted intravenous
bolus injection (1.3 ml of agitated Definity diluted in 8.7 ml of preservative free saline) and a second
injection was administered if necessary to maintain adequate contrast opacification throughout the duration
of imaging. For contrast echo, the mechanical index (power) was decreased to < 0.8 (typically 0.3-0.4) and
adjusted based on LV cavity opacity. The focal zone position was initially set to the level of the mitral valve
in order to provide a comprehensive assessment of the left ventricle and adjusted thereafter to better visualize
any localized areas suspicious for thrombus. Imaging was initiated immediately following contrast
administration and continued until the LV was imaged in at least three (2-, 3-, 4- chamber) apical imaging
planes. Patients with contrast or non-contrast echoes that acquired fewer than 3 apical views were excluded
from the study population.
Following study initiation, the study/IRB protocol was subsequently revised in October 2007 to
reflect an interim product labeling change recommended by the United Stated Food and Drug Administration
concerning contraindications to use of the echo contrast agent (DEFINITY).8 In accordance with product
manufacturer recommendations between October 2007 – May 2008, patients imaged between October 2007
and the conclusion of the study (November 2007) were excluded from receiving echo contrast if there was
evidence of known or suspected cardiac shunts, respiratory failure or severe emphysema, pulmonary emboli
or pulmonary hypertension, acute coronary syndrome or acute myocardial infarction, serious ventricular
arrhythmias, or worsening or clinically unstable congestive heart failure at the time of imaging. 97% of the
study population underwent imaging prior to revision of the study protocol.