Ursula Reiter1, Gert Reiter, Katrin Dorr, Andreas Greiser, Ralph Maderthaner, Michael Fuchsjäger. 1. From the Department of Radiology, Medical University of Graz, Auenbruggerplatz 9/P, A-8036 Graz, Austria (U.R., R.M., M.F.); Siemens, Healthcare Sector, Graz, Austria (G.R.); Department of Radiology, Feldbach Regional Hospital, Feldbach, Austria (K.D.); and Siemens, Healthcare Sector, Erlangen, Germany (A.G.).
Abstract
PURPOSE: To introduce blood normalization for myocardial T1 values at magnetic resonance (MR) imaging and to evaluate regional differences between systolic and diastolic myocardial T1 values in healthy subjects. MATERIALS AND METHODS: This prospective study (ClinicalTrials.gov identification number, NCT01728597) was approved by the institutional review board, and volunteer informed consent was obtained. Forty healthy subjects (20 women; age range, 20-35 years) underwent electrocardiographically gated 1.5-T MR imaging. A modified Look-Locker inversion recovery sequence was used to acquire myocardial T1 maps in systole and diastole. Regional T1 values were evaluated in 16 myocardial segments; blood T1 was derived from the blood pool in the center of the left ventricular cavity. Linear regression slopes between myocardial and blood T1 values were used to normalize myocardial T1 to the mean blood T1 of the study population. Mean T1 values were compared by using the t test, with P < .05 considered to indicate a significant difference. RESULTS: Mean myocardial T1 (984 msec ± 28 [standard deviation] in diastole, 959 msec ± 21 in systole) and all segmental T1 values between diastole and systole differed significantly (P < .001). Blood T1 correlated well with segmental myocardial T1 (R = 0.73 for diastole, R = 0.72 for systole). After normalization to blood T1, significant sex differences in myocardial T1 disappeared and variances in mean myocardial T1 decreased. Blood-normalized diastolic and systolic myocardial T1 values correlated strongly with each other on segmental (r = 0.72) and global (r = 0.89) levels. Subregional myocardial T1 distribution characteristics in diastole were similar to those in systole. CONCLUSION: In normal myocardium, diastolic and systolic myocardial T1 values differ significantly but correlate strongly. Blood normalization eliminates sex differences in myocardial T1 values and reduces their variability.
PURPOSE: To introduce blood normalization for myocardial T1 values at magnetic resonance (MR) imaging and to evaluate regional differences between systolic and diastolic myocardial T1 values in healthy subjects. MATERIALS AND METHODS: This prospective study (ClinicalTrials.gov identification number, NCT01728597) was approved by the institutional review board, and volunteer informed consent was obtained. Forty healthy subjects (20 women; age range, 20-35 years) underwent electrocardiographically gated 1.5-T MR imaging. A modified Look-Locker inversion recovery sequence was used to acquire myocardial T1 maps in systole and diastole. Regional T1 values were evaluated in 16 myocardial segments; blood T1 was derived from the blood pool in the center of the left ventricular cavity. Linear regression slopes between myocardial and blood T1 values were used to normalize myocardial T1 to the mean blood T1 of the study population. Mean T1 values were compared by using the t test, with P < .05 considered to indicate a significant difference. RESULTS: Mean myocardial T1 (984 msec ± 28 [standard deviation] in diastole, 959 msec ± 21 in systole) and all segmental T1 values between diastole and systole differed significantly (P < .001). Blood T1 correlated well with segmental myocardial T1 (R = 0.73 for diastole, R = 0.72 for systole). After normalization to blood T1, significant sex differences in myocardial T1 disappeared and variances in mean myocardial T1 decreased. Blood-normalized diastolic and systolic myocardial T1 values correlated strongly with each other on segmental (r = 0.72) and global (r = 0.89) levels. Subregional myocardial T1 distribution characteristics in diastole were similar to those in systole. CONCLUSION: In normal myocardium, diastolic and systolic myocardial T1 values differ significantly but correlate strongly. Blood normalization eliminates sex differences in myocardial T1 values and reduces their variability.
Authors: Jaime L Shaw; Michael D Nelson; Janet Wei; Manish Motwani; Sofy Landes; Puja K Mehta; Louise E J Thomson; Daniel S Berman; Debiao Li; C Noel Bairey Merz; Behzad Sharif Journal: Int J Cardiol Date: 2018-06-22 Impact factor: 4.164
Authors: Nadine Kawel-Boehm; Scott J Hetzel; Bharath Ambale-Venkatesh; Gabriella Captur; Christopher J Francois; Michael Jerosch-Herold; Michael Salerno; Shawn D Teague; Emanuela Valsangiacomo-Buechel; Rob J van der Geest; David A Bluemke Journal: J Cardiovasc Magn Reson Date: 2020-12-14 Impact factor: 5.364