Shi-Jun Zhang, Presenter: Nothing to Disclose

Sheng Hong Ju MD, PhD, Abstract Co-Author: Nothing to Disclose

To investigate whether the myocardial extracellular volume fraction (ECV) of women differs from that of men in healthy population.

Institutional review board approval and informed consent were obtained. Twenty-eight healthy volunteers (11 men and 17 women, aged 19 to 63 years) were recruited and underwent MRI scan with a 0.15 mmol/kg intravenous bolus of Gd-DTPA. A mid-cavity short-axis plane was selected for T1 mapping precontrast and repetitively after contrast injection, using the modified Look-Locker inversion recovery (MOLLI) sequence. Regions of interest (ROIs) were selected from four segments (the septal, anterior, lateral and inferior wall of the left ventricular) within the myocardium for ECV calculating in each person. The ECV was calculated as: ECV = λ • (1 - hematocrit), where λ is the myocardial contrast partition coefficient, and was calculated by relating change in longitudinal relaxation rate (R1 = 1/T1) of myocardium (R1m) versus that of left ventricular blood pool (R1b). Independent-samples t tests were applied to compare ECV between the two sexes groups on both per-segment and per-person basis.    

Three out of the 112 segments were excluded from two men due to sever artifact, remaining 41 segments in men and 68 segments in women. The mean values (±standard deviation) of ECV within the septal, anterior, lateral and inferior left ventricular wall were 0.238±0.023, 0.235±0.024, 0.245±0.032 and 0.240±0.022 in the 11 men, while in the 17 women, the values were 0.273±0.023, 0.275±0.033, 0.279±0.025 and 0.276±0.034. The mean difference (95% confident interval, 95%CI) for the four segments between the two sexes groups were 0.034 (0.016-0.053), 0.040 (0.016-0.063), 0.034(0.012-0.057) and 0.036 (0.010-0.063). The overall mean ECV values of these two groups on per-segment basis were 0.239 ± 0.025 and 0.275 ± 0.029, P < 0.001. The per-person ECV were calculated as the arithmetic mean value of the ROIs from the 4 segments, and the mean values of the two groups were 0.239 ± 0.024 and 0.275 ± 0.024, P = 0.001.

Women’s myocardial extracellular volume fraction is higher than men’s in healthy population.

The higher myocardial ECV in healthy women than men indicates studies ideally consist of subgroups of each gender may help to interpret the research and clinical results involving myocardial ECV.

Zhang, S, Ju, S, Higher Myocardial Extracellular Volume Fraction in Women than Men: Study by Contrast Enhanced Cardiac Magnetic Resonance Imaging.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13017055.html