AIMS: To compare cardiac magnetic resonance (CMR) measurement of T1 reactivity (ΔT1) with [15O]H2O positron emission tomography (PET) measurements of quantitative myocardial perfusion. METHODS AND RESULTS: Forty-three patients with suspected obstructed coronary artery disease underwent [15O]H2O PET and CMR at 1.5-T, including rest and adenosine stress T1 mapping (ShMOLLI) and late gadolinium enhancement to rule out presence of scar tissue. ΔT1 was determined for the three main vascular territories and compared with [15O]H2O PET-derived regional stress myocardial blood flow (MBF) and myocardial flow reserve (MFR). ΔT1 showed a significant but poor correlation with stress MBF (R2 = 0.04, P = 0.03) and MFR (R2 = 0.07, P = 0.004). Vascular territories with impaired stress MBF (i.e. ≤2.30 mL/min/g) demonstrated attenuated ΔT1 compared with vascular territories with preserved stress MBF (2.9 ± 2.2% vs. 4.1 ± 2.2%, P = 0.008). In contrast, ΔT1 did not differ between vascular territories with impaired (i.e. <2.50) and preserved MFR (3.2 ± 2.6% vs. 4.0 ± 2.1%, P = 0.25). Receiver operating curve analysis of ΔT1 resulted in an area under the curve of 0.66 [95% confidence interval (CI): 0.57-0.75, P = 0.009] for diagnosing impaired stress MBF and 0.62 (95% CI: 0.53-0.71, P = 0.07) for diagnosing impaired MFR. CONCLUSIONS: CMR stress T1 mapping has poor agreement with [15O]H2O PET measurements of absolute myocardial perfusion. Stress T1 and ΔT1 are lower in vascular territories with reduced stress MBF but have poor accuracy for detecting impaired myocardial perfusion.

Original languageEnglish
Pages (from-to)229-237
Number of pages9
JournalEuropean Heart Journal Cardiovascular Imaging
Issue number2
Publication statusPublished - 24 Jan 2022


  • T1 mapping
  • cardiac magnetic resonance
  • coronary artery disease
  • myocardial ischaemia
  • positron emission tomography

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