Limits...
Histological Validation of measurement of diffuse interstitial myocardial fibrosis by myocardial extravascular volume fraction from Modified Look-Locker imaging (MOLLI) T1 mapping at 3 T.

de Meester de Ravenstein C, Bouzin C, Lazam S, Boulif J, Amzulescu M, Melchior J, Pasquet A, Vancraeynest D, Pouleur AC, Vanoverschelde JL, Gerber BL - J Cardiovasc Magn Reson (2015)

Bottom Line: The average amount of interstitial fibrosis by picrosirius red staining in biopsy samples was 6.1 ± 4.3%.ECV determined by 3 T CMR T1 MOLLI images closely correlates with histologically determined diffuse interstitial fibrosis, providing a non-invasive estimation for quantification of interstitial fibrosis in patients with valve diseases.By opposition, neither non-contrast T1 times nor the amount of LGE were indicative of the magnitude of diffuse interstitial fibrosis measured by histopathology.

View Article: PubMed Central - PubMed

Affiliation: Division of Cardiology, Department of Cardiovascular Diseases, Cliniques Universitaires St. Luc UCL, Av Hippocrate 10 / 2806, B-1200, Woluwe St. Lambert, Belgium. christophe.demeester@uclouvain.be.

ABSTRACT

Background: Gadolinium (Gd) Extracellular volume fraction (ECV) by Cardiovascular Magnetic Resonance (CMR) has been proposed as a non-invasive method for assessment of diffuse myocardial fibrosis. Yet only few studies used 3 T CMR to measure ECV, and the accuracy of ECV measurements at 3 T has not been established. Therefore the aims of the present study were to validate measurement of ECV by MOLLI T1 mapping by 3 T CMR against fibrosis measured by histopathology. We also evaluated the recently proposed hypothesis that native-T1 mapping without contrast injection would be sufficient to detect fibrosis.

Methods: 31 patients (age = 58 ± 17 years, 77% men) with either severe aortic stenosis (n = 12) severe aortic regurgitation (n = 9) or severe mitral regurgitation (n = 10), all free of coronary artery disease, underwent 3 T-CMR with late gadolinium enhancement (LGE) and pre- and post-contrast MOLLI T1 mapping and ECV computation, prior to valve surgery. LV biopsies were performed at the time of surgery, a median 13 [1-30] days later, and stained with picrosirius red. Pre-, and post-contrast T1 values, ECV, and amount of LGE were compared against magnitude of fibrosis by histopathology by Pearson correlation coefficients.

Results: The average amount of interstitial fibrosis by picrosirius red staining in biopsy samples was 6.1 ± 4.3%. ECV computed from pre-post contrast MOLLI T1 time changes was 28.9 ± 5.5%, and correlated (r = 0.78, p < 0.001) strongly with the magnitude of histological fibrosis. By opposition, neither amount of LGE (r = 0.17, p = 0.36) nor native pre-contrast myocardial T1 time (r = -0.18, p = 0.32) correlated with fibrosis by histopathology.

Conclusions: ECV determined by 3 T CMR T1 MOLLI images closely correlates with histologically determined diffuse interstitial fibrosis, providing a non-invasive estimation for quantification of interstitial fibrosis in patients with valve diseases. By opposition, neither non-contrast T1 times nor the amount of LGE were indicative of the magnitude of diffuse interstitial fibrosis measured by histopathology.

No MeSH data available.


Related in: MedlinePlus

Bland-Altmann analysis of inter and intra observer reproducibility of T1 times and ECV. a intra observer and b inter-observer reproducibility of post-contrastT1 times measurement, c intra- and d inter-observer reproducibility of ECV measurements. Obs: Observer, Myoc: Myocardium, post-c.: post-contrast
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4464705&req=5

Fig5: Bland-Altmann analysis of inter and intra observer reproducibility of T1 times and ECV. a intra observer and b inter-observer reproducibility of post-contrastT1 times measurement, c intra- and d inter-observer reproducibility of ECV measurements. Obs: Observer, Myoc: Myocardium, post-c.: post-contrast

Mentions: Histological measurements of fibrosis had an intraobserver reproducibility (ICC) of 0.99 with a bias of 0 ± 2 % and interobserver reproducibility (ICC) of 0.82 with a bias of 0 ± 4 %. Intra and interobserver reproducibility for myocardial pre-contrast T1 times were ICC = 0.99 and ICC = 0.91 with bias of 7 ± 46 ms and 0 ± 55 ms respectively. Intra and interobserver reproducibility for post contrast T1 time measurement were ICC = 0.60 and 0.75 with bias of 13 ± 16 and 9 ± 29 ms respectively. Finally, intra- and inter-observer reproducibility for ECV were ICC = 0.51 and 0.61 with bias of −0.9 ± 2.2 % and −0.9 ± 3.6 % respectively (Fig. 5). Scan-rescan reproducibility of myocardial T1 time was ICC = 0.84 with a bias of 2 ± 39 ms. Scan-rescan reproducibility of ECV was ICC = 0.82 with a biais of −0.46 ± 2.4 %.Fig. 5


Histological Validation of measurement of diffuse interstitial myocardial fibrosis by myocardial extravascular volume fraction from Modified Look-Locker imaging (MOLLI) T1 mapping at 3 T.

de Meester de Ravenstein C, Bouzin C, Lazam S, Boulif J, Amzulescu M, Melchior J, Pasquet A, Vancraeynest D, Pouleur AC, Vanoverschelde JL, Gerber BL - J Cardiovasc Magn Reson (2015)

Bland-Altmann analysis of inter and intra observer reproducibility of T1 times and ECV. a intra observer and b inter-observer reproducibility of post-contrastT1 times measurement, c intra- and d inter-observer reproducibility of ECV measurements. Obs: Observer, Myoc: Myocardium, post-c.: post-contrast
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4464705&req=5

Fig5: Bland-Altmann analysis of inter and intra observer reproducibility of T1 times and ECV. a intra observer and b inter-observer reproducibility of post-contrastT1 times measurement, c intra- and d inter-observer reproducibility of ECV measurements. Obs: Observer, Myoc: Myocardium, post-c.: post-contrast
Mentions: Histological measurements of fibrosis had an intraobserver reproducibility (ICC) of 0.99 with a bias of 0 ± 2 % and interobserver reproducibility (ICC) of 0.82 with a bias of 0 ± 4 %. Intra and interobserver reproducibility for myocardial pre-contrast T1 times were ICC = 0.99 and ICC = 0.91 with bias of 7 ± 46 ms and 0 ± 55 ms respectively. Intra and interobserver reproducibility for post contrast T1 time measurement were ICC = 0.60 and 0.75 with bias of 13 ± 16 and 9 ± 29 ms respectively. Finally, intra- and inter-observer reproducibility for ECV were ICC = 0.51 and 0.61 with bias of −0.9 ± 2.2 % and −0.9 ± 3.6 % respectively (Fig. 5). Scan-rescan reproducibility of myocardial T1 time was ICC = 0.84 with a bias of 2 ± 39 ms. Scan-rescan reproducibility of ECV was ICC = 0.82 with a biais of −0.46 ± 2.4 %.Fig. 5

Bottom Line: The average amount of interstitial fibrosis by picrosirius red staining in biopsy samples was 6.1 ± 4.3%.ECV determined by 3 T CMR T1 MOLLI images closely correlates with histologically determined diffuse interstitial fibrosis, providing a non-invasive estimation for quantification of interstitial fibrosis in patients with valve diseases.By opposition, neither non-contrast T1 times nor the amount of LGE were indicative of the magnitude of diffuse interstitial fibrosis measured by histopathology.

View Article: PubMed Central - PubMed

Affiliation: Division of Cardiology, Department of Cardiovascular Diseases, Cliniques Universitaires St. Luc UCL, Av Hippocrate 10 / 2806, B-1200, Woluwe St. Lambert, Belgium. christophe.demeester@uclouvain.be.

ABSTRACT

Background: Gadolinium (Gd) Extracellular volume fraction (ECV) by Cardiovascular Magnetic Resonance (CMR) has been proposed as a non-invasive method for assessment of diffuse myocardial fibrosis. Yet only few studies used 3 T CMR to measure ECV, and the accuracy of ECV measurements at 3 T has not been established. Therefore the aims of the present study were to validate measurement of ECV by MOLLI T1 mapping by 3 T CMR against fibrosis measured by histopathology. We also evaluated the recently proposed hypothesis that native-T1 mapping without contrast injection would be sufficient to detect fibrosis.

Methods: 31 patients (age = 58 ± 17 years, 77% men) with either severe aortic stenosis (n = 12) severe aortic regurgitation (n = 9) or severe mitral regurgitation (n = 10), all free of coronary artery disease, underwent 3 T-CMR with late gadolinium enhancement (LGE) and pre- and post-contrast MOLLI T1 mapping and ECV computation, prior to valve surgery. LV biopsies were performed at the time of surgery, a median 13 [1-30] days later, and stained with picrosirius red. Pre-, and post-contrast T1 values, ECV, and amount of LGE were compared against magnitude of fibrosis by histopathology by Pearson correlation coefficients.

Results: The average amount of interstitial fibrosis by picrosirius red staining in biopsy samples was 6.1 ± 4.3%. ECV computed from pre-post contrast MOLLI T1 time changes was 28.9 ± 5.5%, and correlated (r = 0.78, p < 0.001) strongly with the magnitude of histological fibrosis. By opposition, neither amount of LGE (r = 0.17, p = 0.36) nor native pre-contrast myocardial T1 time (r = -0.18, p = 0.32) correlated with fibrosis by histopathology.

Conclusions: ECV determined by 3 T CMR T1 MOLLI images closely correlates with histologically determined diffuse interstitial fibrosis, providing a non-invasive estimation for quantification of interstitial fibrosis in patients with valve diseases. By opposition, neither non-contrast T1 times nor the amount of LGE were indicative of the magnitude of diffuse interstitial fibrosis measured by histopathology.

No MeSH data available.


Related in: MedlinePlus