Incidental Extra - cardiac Findings on Clinical CMR ; A Comparison of 3 HASTE

Objectives: First, we sought to assess the frequency of incidental extra-cardiac findings (IEF) found in a consecutive series of clinical Cardiac MR scans. Second, we compared the 3 clinically used HASTE acquisition protocols in this context. Third, we determined the impact of the three different HASTE protocols on acquisition time and image quality. Methods: Three consecutive groups of 238 patients (total 714), referred for clinically indicated CMR, were scanned with either breath-hold HASTE (BH, Group 1), free breathing HASTE (FB, Group 2) or diaphragmatic navigated HASTE (NAV, Group 3) in addition to multi-slice, single shot steady state sequences in 3 orthogonal planes. All 714 clinical reports were reviewed regarding the presence of incidental extracardiac findings and the recommendations on the need for further investigation, follow up, and/or clinical correlation. Finally, to determine the impact of each HASTE protocol on acquisition time and image quality an additional cohort of 15 patients underwent all 3 protocols back to back in a random fashion. The length of each acquisition was timed and image quality was reviewed and scored externally. Results: A total of 180 IEF were found in 162 (22.7%) out of 714 patients. There was no significant difference in frequency of IEF between the 3 HASTE groups. Out of 180 IEF 88 were considered minor and 92 major findings. Of the latter, 8 (1.1%) were considered highly significant including one bronchoalveolar carcinoma stage 1B requiring lobectomy, 2 cases of florid sarcoidosis in patients presenting with VT and “structurally normal hearts” on Echo, one case of pulmonary aspergillosis, 2 cases of advanced pulmonary fibrosis, one ascending thoracic aortic aneurysm and a case of iatrogenic liver haemorrhage following placement of a pericardial drain. FB HASTE acquisition (69±2.5s) was significantly faster than BH (105±3.8s) and NAV (121±2.7s), p<0.001 but also produced the lowest image quality on a 5 point scale; 3.5 (FB) versus 3.9 (BH) versus 3.8 (NAV), p=0.08. Conclusion: Overall, IEF are common and lead to follow on investigations in a substantial minority of cases. However, the overall incidence of highly significant findings in the current study was low (~1%). There was no difference in the frequency of incidental extra-cardiac findings between the 3 HASTE protocols. Whilst the free breathing HASTE technique is statistically significantly faster than breath hold and navigated HASTE the absolute time saving is small and probably out-weight by the resulting lesser image quality.