Purpose:
To evaluate gadocoletic acid (b-22956), a gadolinium-based paramagnetic blood pool agent, for contrast-enhanced coronary magnetic resonance angiography (mra) in a phase i clinical trial, and to compare the findings with those obtained using a standard noncontrast t2 preparation sequence.
Materials and methods:
The left coronary system was imaged in 12 healthy volunteers before b-22956 application and 5 (n = 11) and 45 (n = 7) minutes after application of 0.075 mmol/kg of body weight (bw) of b-22956. additionally, imaging of the right coronary system was performed 23 minutes after b-22956 application (n = 6). a three-dimensional gradient echo sequence with t2 preparation (precontrast) or inversion recovery (ir) pulse (postcontrast) with real-time navigator correction was used. assessment of the left and right coronary systems was performed qualitatively (a 4-point visual score for image quality) and quantitatively in terms of signal-to-noise ratio (snr), contrast-to-noise ratio (cnr), vessel sharpness, visible vessel length, maximal luminal diameter, and the number of visible side branches.
Results:
Significant (p < 0.01) increases in snr (+42%) and cnr (+86%) were noted five minutes after b-22956 application, compared to precontrast t2 preparation values. a significant increase in cnr (+40%, p < 0.05) was also noted 45 minutes postcontrast. vessels (left anterior descending artery (lad), left coronary circumflex (lcx), and right coronary artery (rca)) were also significantly (p < 0.05) sharper on postcontrast images. significant increases in vessel length were noted for the lad (p < 0.05) and lcx and rca (both p < 0.01), while significantly more side branches were noted for the lad and rca (both p < 0.05) when compared to precontrast t2 preparation values.
Conclusion:
The use of the intravascular contrast agent b-22956 substantially improves both objective and subjective parameters of image quality on high-resolution three-dimensional coronary mra. the increase in snr, cnr, and vessel sharpness minimizes current limitations of coronary artery visualization with high-resolution coronary mra.