MRI detection of myocardial perfusion defects due to coronary artery stenosis with MS-325.
OBJECTIVE
To assess the value of an intravascular, albumin-targeted contrast agent, MS-325, in visualizing myocardial ischemia with magnetic resonance imaging (MRI).


METHODS
Left anterior descending coronary artery (LAD) stenosis was created in 19 pigs using a closed-chest modified angioplasty technique. Myocardial ischemia was detected by first-pass, contrast-enhanced MRI at peak dipyridamole stress and was compared to Technetium-99m (Tc-99m) sestamibi single photon emission computed tomography (SPECT). Regional coronary blood flow was determined using microspheres.


RESULTS
Inducible myocardial ischemia with >40% reduction in stress myocardial blood flow was created in eight animals. An MRI defect, classified as > or=75% reduction in peak myocardial signal intensity in the affected territory, was detected in 92.3% of these animals. In the presence of mild coronary stenosis, there was uniform enhancement with MRI and tracer uptake by SPECT. Concordance of MRI and SPECT for detecting perfusion defects was 85%.


CONCLUSIONS
The pattern of prolonged and persistent MR hypoenhancement of the ischemic myocardial bed using MS-325, which is retained primarily in the vascular bed due to its albumin-binding properties, facilitates the detection of myocardial perfusion defects.
Kraitchman
Dara L
DL
Departments of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-0845, USA. dara@mri.jhu.edu
Chin
Bennett B
BB
Heldman
Alan W
AW
Solaiyappan
Meiyappan
M
Bluemke
David A
DA
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D003326:Coronary Circulation / Q000502:physiology*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004353:Drug Evaluation, Preclinical; D005240:Feasibility Studies; D005682:Gadolinium; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D009942:Organometallic Compounds / Q000008:administration & dosage; D019275:Radiopharmaceuticals; D012107:Research Design; D013552:Swine; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
D003287:Contrast Media; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D005682:Gadolinium; C109932:gadofosveset trisodium