Purpose:
In coronary MRA, 3D gradient echo technique using balanced gradient (steady-state free-precession) and respiratory navigator is widely used recently, while it still cannot visualize the side branches of coronary arteries which are not included in 3D imaging slab and it is time-consuming. The aim of our study was to assess the feasibility and diagnostic accuracy of whole heart coronary MRA using 3D b-TFE with SENSE and Halfscan technique in identifying stenoses of coronary artery.
Materials and Methods:
The 19 patients (14 men and 5 women, mean age 54.3years, range 26-79 years) who underwent both coronary MRA and conventional x-ray coronary angiography within one week were enrolled in this study. Whole heart coronary MRA was acquired using 3D b-TFE sequence with navigator gating. Imaging slab covered whole heart (80 overcontiguous slices with a reconstructed slice thickness of 1.5 mm) in transverse axis. SENSE and Halfscan were used to decrease acquisition time. Source images and reconstructed images (volume rendering and multiplanar reformation) of MRA were analyzed. Image quality was evaluated using 5-point scale (0-uninterpretable, 1-poor, 2-fair, 3-good, 4-excellent). Diagnostic accuracy of coronary MRA in the detection of significant coronary artery stenosis was determined on segment-by-segment basis with reference to conventional x-ray angiography.
Results
Using the 5-point scale, mean image quality was 3.7 in LM, 3.3 in LAD, 2.4 in LCX, and 3.2 in RCA, respectively (overall image quality 2.6±0.1). The segments with acceptable image quality (> grade 2) were 151 (83%) of 181 segments. Sensitivity, specificity, accuracy, negative predictive value and positive predictive value of whole heart coronary MRA was 81.3%, 91.1%, 90.1%, 97.6% and 52.0%, respectively. Mean acquisition time of coronary MRA was 9 min 22sec.
Conclusion
Whole heart coronary MRA using free-breathing 3D b-TFE with SENSE and Halfscan has the potential for evaluation of major portions of coronary arteries with an acceptable image quality and high diagnostic accuracy within reasonable scanning time.
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