MR-koronarangiographie mit MS-325, einem blood-pool-kontrastmittel: Vergleich einer inversion recovery steady-state free precession und einer inversion recovery fast low angle shot sequenz in probanden

Purpose: To compare the signal-to-noise and contrast-to-noise ratio as well as the image quality of 3D inversion recovery steady-state free precession (IR-SSFP) and 3D inversion recovery fast low angle shot (IR-FLASH) sequences for contrast-enhanced breath-hold MRCA. Materials and Methods: 24 healthy volunteers (10 female, 14 male, mean age 29.8 ± 6.1 years) were involved in this study. All examinations were performed on a 1.5 T MR scanner (Magnetom Sonata, Siemens, Germany) after injection of 0.05 mmol/kg body weight MS-325 (EPIX Pharmaceuticals, Cambridge, MA and Schering AG, Berlin, Germany). MRCA was performed using IR-SSFP (TR 3.8 ms, TE 1.6 ms, FA 65°, 35 phase encoded steps, bandwidth 540 Hz/pixel, slice thickness 1.5 mm, in-plane resolution 1.2 × 0.9-1.4 × 1.0 mm) and IR-FLASH (TR 3.8 ms, TE 1.6 ms, FA 25°, bandwidth 490 Hz/pixel, slice thickness 1.5 mm, in-plane resolution 1.2 × 0.9-1.4 × 1.0 mm) sequences. For all scans the inversion time was set to null the signal intensity of the myocardium. Signal-to-noise ratio (SNR) as well as contrast-to-noise ratio (CNR) measurements (blood versus myocardium) were performed. The image quality was assessed based on a 5-point scale ranging from 1 (excellent) to 5 (non-diagnostic) by two radiologists in consensus. Results: The mean signal-to-noise ratio of blood (27.7 ± 4.7 vs. 22.6 ± 4.9, P < 0.0001) and the contrast-to-noise ratio (21.0 ± 4.3 vs. 15.8 ± 4.3, P < 0.0001) showed significantly higher values for IR-SSFP sequences. The mean image quality scores were significantly higher for SSFP (3.6 ± 0.7) than FLASH (2.8 ± 0.9) sequences (P < 0.05). Conclusion: IR-SSFP sequences show a considerable overall improvement in image quality compared to IR-FLASH sequences for MRCA after injection of a gadolinium-based blood pool contrast agent.