Diagnosis of immune-checkpoint inhibitor myocarditis using cardiovascular MRI, a specificity study

Motivation: Immune checkpoint inhibitors (ICI) are important in cancer treatment, however their use is limited by the ICI myocarditis. Cardiac MR is a major clinical criterion in diagnosis of ICI-myocarditis. Goal(s): To determine the prevalence of abnormal T1 and/or T2 findings in cardio-oncology population not receiving ICIs. Approach: Seventy-one cardio-oncology patients underwent CMR with T1, T2, and late gadolinium enhancement (LGE) measurement. Results: Abnormal T1 findings were found among 32% participants. T2 was normal in all subjects. Using T1 criteria alone for myocarditis would have 68% specificity but combining T1 and T2 increased the specificity to 100%. Impact: Among cardio-oncology patients not receiving ICIs, prevalence of T1 abnormalities is high which could lead to low specificity of CMR in diagnosis of acute myocarditis. Using both T1 and T2 criteria would improve the specificity.