Background It is hard for patients with impaired breath-holding (BH) capacity to receive conventional cardiac magnetic resonance (CCMR) imaging.
Purpose To explore the clinical utility of a free-breathing (FB) CMR (FCMR) imaging protocol at 3.0T.
Methods 54 selected patients with suspected heart disease were prospectively enrolled. A total of 30 patients with good BH underwent CCMR protocols first and then FCMR imaging protocols. For other 24 patients with bad BH, CCMR protocols were aborted due to limited BH capacity of patients that led to non-diagnostic image quality (IQ), and the study was finished with FCMR protocols. CCMR included segmented cine and late gadolinium enhancement (LGE) images acquired under BH. FCMR included compressed sensing (CS) accelerated, single-shot cine and motion-corrected (MOCO) single-shot LGE images acquired under FB. IQ of both protocols was evaluated based on a five-point Likert scale. The imaging time, the left ventricular function(LVF), scar presence/absence, and IQ were compared between CCMR and FCMR protocols.
Results The acquisition times of the FB-CS-cine SAX (25 ± 5s), FB-CS-cine LAX(8 ± 2s), and FB-MOCO-LGE SAX (120 ± 19s), FB-MOCO-LGE LAX(37 ± 6s) were significantly shorter than these with BH-cine SAX (240 ± 13s), BH-cine LAX (75 ± 16s) and BH-LGE SAX(331 ± 29s), BH-LGE LAX(100 ± 9s) respectively (all P<0.001). For 30 patients that finished both CCMR and FCMR protocols, it was shown that IQ in FB-CS-cine is lower than BH-cine [4 (3-4) vs. 5 (4-5) , P <0.001], however FB-MOCO-LGE is better than BH-LGE [5 (4-5) vs. 3 (3-4), P <0.001]. No significant differences were found in LVF, and LGE presence(all P>0.05). The 24 patients with limited BH capabilities had inconclusive results with the CCMR protocol, but definitive diagnoses were made with the FCMR protocol.
Conclusions FCMR could be used as an alternative scanning protocol in patients with BH impairments, making CMR imaging more widely available also for vulnerable patients.