# A comparison of T1ρ with native T1 and T2 mapping for detecting edema in takotsubo cardiomyopathy

## TL;DR

This study compares T1ρ, T1, and T2 mapping to detect heart muscle swelling in takotsubo cardiomyopathy, finding that T1 and T2 mapping are more effective.

## Contribution

The study introduces a direct comparison of T1ρ with established T1 and T2 mapping techniques for edema detection in takotsubo cardiomyopathy.

## Key findings

- T1ρ relaxation times were significantly higher in mid and apical segments during takotsubo baseline scans.
- T2 and native T1 relaxation times were elevated in all segments during takotsubo baseline scans compared to follow-up and healthy controls.
- Native T1 and T2 mapping showed better sensitivity for detecting edema than T1ρ mapping.

## Abstract

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 potential to assess myocardial tissue characterization. This study aims to compare T1ρ with native T1 and T2 myocardial mapping in takotsubo cardiomyopathy.

T1ρ, T2, and native T1 relaxation times were obtained for 51 patients (96% (49/51) female, mean age 69) diagnosed with takotsubo cardiomyopathy and 16 healthy subjects (100% (16/16) female, mean age 41). The baseline scan for the takotsubo cohort was done within 3 weeks after symptom onset, with follow-up scans carried out on average 9 weeks after the baseline scan. Cardiac function and T1ρ, T2, native T1 maps of basal, mid, and apical segments were analyzed.

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 was 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.

In patients with takotsubo cardiomyopathy, T1ρ values were significantly elevated in the mid and apical segments, where edema 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 edema compared to T1ρ mapping.

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