Purpose:To evaluate the efficacy of contrast-enhanced coronary magnetic resonance angiography (MRA) at 3.0 T.
Materials and Methods:Nine healthy human volunteers were studied on a 3.0-T whole-body MR system. A threedimensional, breathhold, magnetization-prepared, segmented, gradient-echo sequence was used, with injection of 20 mL gadopentetate dimeglumine for each three-dimensional slab. Imaging parameters were optimized based on computer simulations. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), depicted coronary artery length, lumen diameter, and imaging sharpness with contrast agent were evaluated. SNR and CNR were compared to the results from a previous 1.5-T study.Results: A 53% increment in SNR and a 305% enhancement in CNR were measured with contrast. Vessel length and sharpness depicted were higher and the lumen diameter was lower (all P values Ͻ 0.05) in postcontrast images. Compared to previous results from 1.5-T, the SNR, CNR, and vessel sharpness were enhanced at 3.0 T with higher spatial resolution.
Conclusion:Contrast-enhanced, three-dimensional, coronary MRA at 3.0 T is a promising technique for diagnosing coronary artery diseases. Patient studies are necessary to evaluate its clinical utility. VOLUME-TARGETED IMAGING is a promising approach to magnetic resonance angiography (MRA) of coronary arteries (1,2). For each targeted scan, a thin three-dimensional slab is acquired at a user-predefined orientation. This method has several advantages, including good coverage of the vessels of interest, and the ability to postprocess the three-dimensional dataset. However, continuous respiratory motion and cardiac motion have to be compensated for during coronary artery imaging. The actual data acquisition time for each three-dimensional slab is limited, due to motion compensation using gating techniques. Therefore, one of the major challenges for coronary MRA is to achieve adequate signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and spatial resolution in a limited imaging time.Various T 1 -shortening contrast agents have been extensively used at 1.5 T for coronary artery imaging (3,4). Although these agents have been shown to be effective in improving the blood-background contrast, further improvement in blood signal intensity and blood-myocardial contrast has always been a driving force of current research. The recent advent of 3.0-T whole-body scanners is a promising development in imaging hardware. In theory, 3.0-T scanners should double the signal intensity as compared to 1.5-T. A previous in vivo human study at 3.0 T showed substantial enhancement of blood signal intensity over 1.5 T in coronary MR imaging (5). Further enhancement is expected with contrast agent administration. Up to now, no contrastenhanced coronary MRA study at 3.0 T has been reported and its efficacy remains to be determined.The purpose of this study was to evaluate the performance of a contrast-enhanced coronary MRA at 3.0 T using an extravascular, paramagnetic contrast agent: gadopentetate dimeglumine. Me...
