Improving image quality by comparing two chest MRI sequences: free-breathing T1-weighted Star-VIBE and breath-holding T1-weighted 3D VIBE Dixon.

OBJECTIVE

To explore the feasibility of using magnetic resonance imaging (MRI) with T1-weighted free-breathing Star-VIBE sequences for improving image quality in chest examinations compared with conventional T1-weighted breath-hold VIBE (C-VIBE) sequences.

METHODS

The data of 20 patients with chest MRI examinations in our hospital were prospectively collected. The scanning sequences included conventional breath-hold T1-weighted VIBE sequences (echo time [TE]: 1.29 ms; repetition time [TR]: 3.97 ms) and free-breathing T1-weighted Star-VIBE sequences (TE: 1.39 ms; TR: 2.79 ms). The signal intensity (SI) and standard deviation (SD) of the ascending aorta, pulmonary artery trunk, and descending aorta were measured at the level of the main pulmonary artery. The signal-to-noise ratio (SNR = SI/SD) and coefficient of variation (CV = SD/SI) of SI were calculated. The MR image quality was subjectively scored double-blindly using a 5-point scoring system by two radiologists who had more than 10 years' experience in diagnosing chest diseases and more than 5 years' experience in MR diagnosis of chest diseases.

RESULTS

The SNR of the ascending aorta, pulmonary artery trunk, and descending aorta with free-breathing T1-weighted Star-VIBE sequences was significantly higher than that of conventional breath-hold T1-weighted VIBE sequences (p < 0.05), while the CV of SI with the former sequences was significantly lower than that of the latter sequences (p < 0.05). The subjective scores of the two radiologists regarding the image quality of the two types of sequences had excellent consistency (κ > 0.80, p < 0.05); the subjective scores for free-breathing T1-weighted Star-VIBE sequences were significantly higher than for conventional breath-hold T1-weighted VIBE sequences (p < 0.05).

CONCLUSION

Magnetic resonance imaging with free-breathing T1-weighted Star-VIBE sequences can significantly improve image quality of chest studies compared with conventional breath-hold T1-weighted VIBE sequences.