Cardiovascular magnetic resonance perfusion imaging at 3-tesla for the detection of coronary artery disease: a comparison with 1.5-tesla.
OBJECTIVE
This study was designed to establish the diagnostic accuracy of cardiovascular magnetic resonance (CMR) perfusion imaging at 3-Tesla (T) in suspected coronary artery disease (CAD).


BACKGROUND
Myocardial perfusion imaging is considered one of the most compelling applications for CMR at 3-T. The 3-T systems provide increased signal-to-noise ratio and contrast enhancement (compared with 1.5-T), which can potentially improve spatial resolution and image quality.


METHODS
Sixty-one patients (age 64 +/- 8 years) referred for elective diagnostic coronary angiography (CA) for investigation of exertional chest pain were studied (before angiogram) with first-pass perfusion CMR at both 1.5- and 3-T and at stress (140 microg/kg/min intravenous adenosine, Adenoscan, Sanofi-Synthelabo, Guildford, United Kingdom) and rest. Four short-axis images were acquired during every heartbeat using a saturation recovery fast-gradient echo sequence and 0.04 mmol/kg Gd-DTPA bolus injection. Quantitative CA served as the reference standard. Perfusion deficits were interpreted visually by 2 blinded observers. We defined CAD angiographically as the presence of > or =1 stenosis of > or =50% diameter in any of the main epicardial coronary arteries or their branches with a diameter of > or =2 mm.


RESULTS
The prevalence of CAD was 66%. All perfusion images were found to be visually interpretable for diagnosis. We found that 3-T CMR perfusion imaging provided a higher diagnostic accuracy (90% vs. 82%), sensitivity (98% vs. 90%), specificity (76% vs. 67%), positive predictive value (89% vs. 84%), and negative predictive value (94% vs. 78%) for detection of significant coronary stenoses compared with 1.5-T. The diagnostic performance of 3-T perfusion imaging was significantly greater than that of 1.5-T in identifying both single-vessel disease (area under receiver-operator characteristic [ROC] curve: 0.89 +/- 0.05 vs. 0.70 +/- 0.08; p < 0.05) and multivessel disease (area under ROC curve: 0.95 +/- 0.03 vs. 0.82 +/- 0.06; p < 0.05). There was no difference between field strengths for the overall detection of coronary disease (area under ROC curve: 0.87 +/- 0.05 vs. 0.78 +/- 0.06; p = 0.23).


CONCLUSIONS
Our study showed that 3-T CMR perfusion imaging is superior to 1.5-T for prediction of significant single- and multi-vessel coronary disease, and 3-T may become the preferred CMR field strength for myocardial perfusion assessment in clinical practice.
Cheng
Adrian S H
AS
University of Oxford Centre for Clinical Magnetic Resonance Research, Oxford, United Kingdom.
Pegg
Tammy J
TJ
Karamitsos
Theodoros D
TD
Searle
Nick
N
Jerosch-Herold
Michael
M
Choudhury
Robin P
RP
Banning
Adrian P
AP
Neubauer
Stefan
S
Robson
Matthew D
MD
Selvanayagam
Joseph B
JB
D000368:Aged; D015331:Cohort Studies; D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis*; D005080:Exercise Test; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011336:Probability; D011446:Prospective Studies; D012372:ROC Curve; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D003287:Contrast Media