- Walking poster presentation
- Open Access
Native myocardial T1 precision is increased by correcting for myocardial blood variation
© Nickander et al; licensee BioMed Central Ltd. 2015
- Published: 3 February 2015
- Blood Pool
- Swedish Research Council
- Stockholm County
- Population Standard Deviation
- Development Agreement
Native myocardial T1 mapping with CMR has emerged as a new diagnostic tool in heart disease. However, myocardial T1 will be affected by the T1 of blood present in the myocardium. To explore this, as there is no easy way to manipulate blood in isolation, we hypothesized that the population standard deviation (SD) for myocardial T1 could be reduced by correcting the myocardial T1 for characteristics of the blood. We sought to compare methods for doing this.
Consecutive patients (n=100, age 53+/-17 years, 74 % male) underwent clinical CMR at 1.5T (Siemens Aera). A modified Look-Locker inversion recovery (MOLLI) sequence was used to acquire T1 and T1* maps. Native myocardial T1 values from the midmural ventricular septum were measured in a mid-ventricular short-axis T1 map. Hematocrit was acquired by venous blood sampling. T1 and T1* values of blood were measured in the blood pool of the left and right ventricle (LV and RV). Myocardial T1 was corrected according to the formula T1corrected = T1uncorrected + slope (mean(X)-X), where X is the blood measurement of T1, T1* or hematocrit, and the slope was calculated as the slope of the linear regression between myocardial T1 and the respective measure.
Correcting native myocardial T1 for variations in blood parameters may reduce the normal variation and hence increase disease detection. The optimal model here was to correct for T1 and T1* of the LV blood pool, providing an 18% reduction in SD of native myocardial T1 measurement in a population. Correction for hematocrit did not provide an incremental improvement in precision. Image-based correction for blood T1 and/or T1* is feasible for clinical use and may improve disease detection in the clinical evaluation of native myocardial T1.
The research was funded in part by the Swedish Research Council, Swedish Heart and Lung Foundation and the Stockholm County Council. Karolinska Institute has a research and development agreement regarding CMR with Siemens.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.