A comparison of T1ρ with native T1 and T2 mapping for detecting oedema in Takotsubo cardiomyopathy.

Abstract

Background: The use of parametric T1 mapping and T2 mapping cardiovascular magnetic resonance (CMR) in takotsubo cardiomyopathy has shown elevated native T1 and T2 relaxation times. In addition to native T1 and T2 mapping, a new native image parametric mapping method using T1 relaxation in the rotating frame (T1ρ) has shown a potential to assess myocardial tissue characterisation. This study aims to compare T1ρ with native T1 and T2 myocardial mapping in takotsubo cardiomyopathy.

Methods: T1ρ, T2 and native T1 relaxation times were obtained for fifty-one patients (96% female, mean age 69) diagnosed with takotsubo cardiomyopathy and sixteen healthy subjects (100% female, mean age 41). The baseline scan for the takotsubo cohort was done within three weeks after symptom onset, with follow-up scans carried out on average nine weeks after the baseline scan. Cardiac function and T1ρ, T2, native T1 maps of basal, mid, and apical segments were analysed.

Results: A significant increase in T1ρ relaxation time was measured in mid and apical segments for the takotsubo baseline cohort compared to takotsubo follow-up cohort (p=0.0006, p=0.0011, respectively). A significant increase in T1ρ relaxation time was measured in mid and apical segments for the takotsubo baseline cohort compared to the healthy volunteer cohort (p<0.0001, p<0.0001, respectively). Significantly elevated T2 and native T1 relaxation were observed in basal (p=0.0344, p=0.0109, respectively) mid (p<0.0001, p<0.0001, respectively) and apical (p<0.0001, p<0.0001, respectively) segments for takotsubo baseline scans when compared to the takotsubo follow-up cohort. Significant increase in T2 and native T1 relaxation values were also observed in basal (p=0.0038, p<0.0001, respectively), mid (p<0.0001, p<0.0001, respectively) and apical (p<0.0001, p<0.0001, respectively) segments for takotsubo baseline cohort when compared to the healthy volunteer cohort.

Conclusion: In patients with Takotsubo cardiomyopathy, T1ρ values were significantly elevated in the mid and apical segments, where oedema is more pronounced. In contrast, both T2 and native T1 values were significantly increased across all three segments-basal, mid, and apical. Consequently, native T1 and T2 mapping showed superior ability to detect oedema compared to T1ρ mapping.