Interventricular differences in myocardial T2 measurements: experimental and clinical studies.
The goal of this study was to determine the accuracy, the reproducibility, and some of the tissue determinants of image-based myocardial T2 measurements. Image-based T2 calculations for the free walls of the right ventricle (RV) and left ventricle (LV), in vitro T2 determination (at 0.47 T), and water, fat, and collagen content analyses were performed in ex vivo hog hearts. T2 values of the RV and LV free walls were also determined from spin-echo images of 14 healthy human subjects. Preliminary reproducibility studies were performed with 10 sets of images acquired from a single subject. For both in vitro and image-based T2 values of hog hearts, RV T2 was significantly longer than LV T2. Water content was the only tissue factor to significantly correlate with in vitro and image-based T2 values. For the 14 human subjects studied, image-based T2 values calculated from the first- and third-echo images demonstrated a significant difference between LV and RV. The difference was not significant when the first- and second-echo images were used. Image-based T2 measurements of a single subject showed a coefficient of variation of 6.8% for the LV and 9.1% for the RV. The authors conclude that image-based T2 measurements of normal myocardium can be made with sufficient precision to identify differences of the magnitude of those found between RV and LV T2 values. Image-based T2 values of myocardium may provide useful data to aid in patient treatment.
Scholz
T D
TD
Cardiovascular Center, University of Iowa, Iowa City 52242.
Fisher
D J
DJ
Ehrhardt
J C
JC
Skorton
D J
DJ
D000328:Adult; D000818:Animals; D005260:Female; D006352:Heart Ventricles / Q000033:anatomy & histology*; D006801:Humans; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging; D008297:Male; D009206:Myocardium / Q000737:chemistry; D015203:Reproducibility of Results; D013552:Swine