Correlation of 3D MR coronary angiography with selective coronary angiography: feasibility of the motion-adapted gating technique

The aim of this study was to verify the feasibility of a respiratory motion compensation technique (motion-adapted gating, MAG) for visualization of coronary arteries (CA) by correlation with selective coronary angiography (SCA). Fifteen subjects (11 patients, mean age 61.3 years, age range 41-73 years; and 4 healthy volunteers, mean age 32.3 years, age range 31-35 years) were investigated. A Philips Gyroscan ACS-NT was used, operating at 1.5 T, was combined with the PowerTrak 6000 gradient system. An ECG-triggered, respiratory motion-gated 3D turbo field echo sequence was used. The real-time algorithm utilized the concept of k-space weighting in combination with automatic analysis of respiratory motion. The main CA were investigated. Qualitative analysis was performed by three blinded investigators. Visibility was graded on a five-point scale (0=not visualized, 1=insufficient, 2=sufficient, 3=good, 4=excellent). Segments graded 2-4 were defined as adequately visualized. Sixty-two of 88 assessable CA segments in patient, and 22 of 32 in volunteer group were adequately visualized. Visibility of CA was classified as excellent for proximal RCA (avg. 3.6+/-0.5), good for LM, proximal LAD, proximal LCX, middle RCA and sufficient for middle LAD. Sensitivity, specificity, positive and negative predictive values for coronary MRA in detection of CA stenoses with luminal narrowing >/=50% were 88, 94, 83, and 96%, respectively. Magnetic resonance imaging in combination with MAG has proven to be a promising technique for noninvasive imaging of CA due to good image quality and a patient convenient free-breathing technique.