title: Variability and homogeneity of cardiovascular magnetic resonance myocardial T2-mapping in volunteers compared to patients with edema.
abstract: BACKGROUND
  The aim of the study was to test the reproducibility and variability of myocardial T2 mapping in relation to sequence type and spatial orientation in a large group of healthy volunteers. For control T2 mapping was also applied in patients with true edema. Cardiovascular magnetic resonance (CMR) T2-mapping has potential for the detection and quantification of myocardial edema. Clinical experience is limited so far. The variability and potential pitfalls in broad application are unknown.
  
  
  METHODS
  Healthy volunteers (n = 73, 35 ± 13 years) and patients with edema (n = 28, 55 ± 17 years) underwent CMR at 1.5 T. Steady state free precession (SSFP) cine loops and T2-weighted spin echo images were obtained. In patients, additionally late gadolinium enhancement images were acquired. We obtained T2 maps in midventricular short axis (SAX) and four-chamber view (4CV) based on images with T2 preparation times of 0, 24, 55 ms and compared fast low angle shot (FLASH) and SSFP readout. 10 volunteers were scanned twice on separate days. Two observers analysed segmental and global T2 per slice.
  
  
  RESULTS
  In volunteers global myocardial T2 systematically differed depending on image orientation and sequence (FLASH 52 ± 5 vs. SSFP 55 ± 5 ms in SAX and 57 ± 6 vs. 59 ± 6 ms in 4CV; p < 0.0001 for both). Anteroseptal and apical segments had higher T2 than inferior and basal segments (SAX: 59 ± 6 vs. 48 ± 5 ms for FLASH and 59 ± 7 vs. 52 ± 4 ms for SSFP; p < 0.0001 for both). 14 volunteers had segments with T2 ≥ 70 ms. Mean intraobserver variability was 1.07 ± 1.03 ms (r = 0.94); interobserver variability was 1.6 ± 1.5 ms (r = 0.87). The coefficient of variation for repeated scans was 7.6% for SAX and 6.6% for 4CV. Mapping revealed focally increased T2 (73 ± 9 vs. 51 ± 3 ms in remote myocardium; p < 0.0001) in all patients with edema.
  
  
  CONCLUSIONS
  Myocardial T2 mapping is technically feasible and highly reproducible. It can detect focal edema and differentiate it from normal myocardium. Increased T2 was found in some volunteers most likely due to partial volume and residual motion.
authors.affiliation: Department of Cardiology and Nephrology, Working Group Cardiac MRI, Humboldt University Berlin, Charite Campus Buch Experimental and Clinical Research Center and HELIOS Klinikum Berlin Buch, Berlin, Germany. ralf.wassmuth@charite.de
authors.forename: Ralf
authors.initials: R
authors.lastname: Wassmuth
authors.forename: Marcel
authors.initials: M
authors.lastname: Prothmann
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Utz
authors.forename: Matthias
authors.initials: M
authors.lastname: Dieringer
authors.forename: Florian
authors.initials: F
authors.lastname: von Knobelsdorff-Brenkenhoff
authors.forename: Andreas
authors.initials: A
authors.lastname: Greiser
authors.forename: Jeanette
authors.initials: J
authors.lastname: Schulz-Menger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D016022:Case-Control Studies; D003287:Contrast Media; D004489:Edema, Cardiac / Q000175:diagnosis* / Q000473:pathology; D005240:Feasibility Studies; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D015588:Observer Variation; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
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