Non-contrast T1-mapping detects acute myocardial edema with high diagnostic accuracy: a comparison to T2-weighted cardiovascular magnetic resonance.
BACKGROUND
T2w-CMR is used widely to assess myocardial edema. Quantitative T1-mapping is also sensitive to changes in free water content. We hypothesized that T1-mapping would have a higher diagnostic performance in detecting acute edema than dark-blood and bright-blood T2w-CMR.


METHODS
We investigated 21 controls (55 ± 13 years) and 21 patients (61 ± 10 years) with Takotsubo cardiomyopathy or acute regional myocardial edema without infarction. CMR performed within 7 days included cine, T1-mapping using ShMOLLI, dark-blood T2-STIR, bright-blood ACUT2E and LGE imaging. We analyzed wall motion, myocardial T1 values and T2 signal intensity (SI) ratio relative to both skeletal muscle and remote myocardium.


RESULTS
All patients had acute cardiac symptoms, increased Troponin I (0.15-36.80 ug/L) and acute wall motion abnormalities but no LGE. T1 was increased in patient segments with abnormal and normal wall motion compared to controls (1113 ± 94 ms, 1029 ± 59 ms and 944 ± 17 ms, respectively; p < 0.001). T2 SI ratio using STIR and ACUT2E was also increased in patient segments with abnormal and normal wall motion compared to controls (all p < 0.02). Receiver operator characteristics analysis showed that T1-mapping had a significantly larger area-under-the-curve (AUC = 0.94) compared to T2-weighted methods, whether the reference ROI was skeletal muscle or remote myocardium (AUC = 0.58-0.89; p < 0.03). A T1 value of greater than 990 ms most optimally differentiated segments affected by edema from normal segments at 1.5 T, with a sensitivity and specificity of 92 %.


CONCLUSIONS
Non-contrast T1-mapping using ShMOLLI is a novel method for objectively detecting myocardial edema with a high diagnostic performance. T1-mapping may serve as a complementary technique to T2-weighted imaging for assessing myocardial edema in ischemic and non-ischemic heart disease, such as quantifying area-at-risk and diagnosing myocarditis.
Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
Vanessa M
VM
Ferreira
Stefan K
SK
Piechnik
Erica
E
Dall'Armellina
Theodoros D
TD
Karamitsos
Jane M
JM
Francis
Robin P
RP
Choudhury
Matthias G
MG
Friedrich
Matthew D
MD
Robson
Stefan
S
Neubauer
D000208:Acute Disease; D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D004489:Edema, Cardiac / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009206:Myocardium / Q000473:pathology*; D015203:Reproducibility of Results; D054549:Takotsubo Cardiomyopathy / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology
D003287:Contrast Media