Suspected chronic myocarditis at cardiac MR: diagnostic accuracy and association with immunohistologically detected inflammation and viral persistence.
OBJECTIVE
To retrospectively compare the diagnostic accuracy of three cardiac magnetic resonance (MR) imaging approaches for the detection of histologic and immunohistologic criteria (reference standard) proved myocardial inflammation in patients clinically suspected of having chronic myocarditis (CMC).


METHODS
Cardiac MR imaging was performed in 83 consecutive patients (55 male, 28 female; mean age, 44.8 years +/- 17.7 [standard deviation]) clinically suspected of having CMC, after written informed consent was obtained according to guidelines of the local ethics committee, which approved the study. T2-weighted triple-inversion-recovery imaging to calculate the edema ratio (ER), T1-weighted imaging before and after contrast agent administration to calculate the myocardial global relative enhancement (gRE), and inversion-recovery gradient-echo imaging to evaluate areas of late gadolinium enhancement (LE) were performed. The MR results were correlated with the endomyocardial biopsy (EMB) findings to detect intramyocardial inflammation and cardiotropic viral genomes analyzed at polymerase chain reaction assay. For statistical analyses, receiver operating characteristic analysis and the Wilcoxon test for unpaired data were used because the Kolomogorov-Smirnov test revealed a distribution of data that was different from normality.


RESULTS
Intramyocardial inflammation and cardiotropic viral persistence were confirmed at immunohistologic analysis in 48 and 49 of the 83 patients, respectively. The sensitivity, specificity, and diagnostic accuracy of the MR parameters, as compared with the immunohistologic detection of inflammation, were, respectively, 62%, 86%, and 72% for gRE; 67%, 69%, and 68% for ER; and 27%, 80%, and 49% for LE. Cardiac MR-derived gRE, ER, and LE were not associated with polymerase chain reaction proof of viral genomes.


CONCLUSIONS
In patients clinically suspected of having CMC, increased gRE and ER indicating inflammation were common findings that could be confirmed at immunohistologic analysis, whereas LE had low sensitivity and accuracy. Cardiac MR imaging may be helpful in detecting intramyocardial inflammation noninvasively, but it fails to depict viral persistence.
Gutberlet
Matthias
M
Department of Diagnostic and Interventional Radiology and Nuclear Medicine, Charité, Campus Virchow Klinikum, Berlin, Germany. matthias.gutberlet@herzzentrum-leipzig.de
Spors
Birgit
B
Thoma
Tobias
T
Bertram
Henriette
H
Denecke
Timm
T
Felix
Roland
R
Noutsias
Michel
M
Schultheiss
Heinz-Peter
HP
Kühl
Uwe
U
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000175:diagnosis* / Q000276:immunology / Q000821:virology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014777:Virus Diseases / Q000175:diagnosis* / Q000276:immunology / Q000821:virology*