Quantitative magnetization transfer imaging for non-contrast enhanced detection of myocardial fibrosis

TY - JOUR

T1 - Quantitative magnetization transfer imaging for non-contrast enhanced detection of myocardial fibrosis

AU - López, Karina

AU - Neji, Radhouene

AU - Bustin, Aurelien

AU - Rashid, Imran

AU - Hajhosseiny, Reza

AU - Malik, Shaihan J.

AU - Teixeira, Rui Pedro A.G.

AU - Razavi, Reza

AU - Prieto, Claudia

AU - Roujol, Sébastien

AU - Botnar, René M.

N1 - Funding Information: This work was supported by (1) the EPSRC Centre for Doctoral Training in Medical Imaging (EP/L015226/1), (2) EPSRC grants EP/P001009/1 and EP/P007619, (3) the Wellcome EPSRC Centre for Medical Engineering (NS/A000049/1 and WT 203148/Z/16/Z), and (4) the Department of Health via the National Institute for Health Research (NIHR) Cardiovascular Health Technology Cooperative (HTC) and comprehensive Biomedical Research Centre awarded to Guy’s & St Thomas’ NHS Foundation Trust in partnership with King’s College London and King’s College Hospital NHS Foundation Trust. KL is co‐funded by Siemens Healthcare GmbH. Funding Information: This work was supported by (1) the EPSRC Centre for Doctoral Training in Medical Imaging (EP/L015226/1), (2) EPSRC grants EP/P001009/1 and EP/P007619, (3) the Wellcome EPSRC Centre for Medical Engineering (NS/A000049/1 and WT 203148/Z/16/Z), and (4) the Department of Health via the National Institute for Health Research (NIHR) Cardiovascular Health Technology Cooperative (HTC) and comprehensive Biomedical Research Centre awarded to Guy?s & St Thomas? NHS Foundation Trust in partnership with King?s College London and King?s College Hospital NHS Foundation Trust. KL is co-funded by Siemens Healthcare GmbH. Publisher Copyright: © 2020 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/4

Y1 - 2021/4

N2 - Purpose: To develop a novel gadolinium-free model-based quantitative magnetization transfer (qMT) technique to assess macromolecular changes associated with myocardial fibrosis. Methods: The proposed sequence consists of a two-dimensional breath-held dual shot interleaved acquisition of five MT-weighted (MTw) spoiled gradient echo images, with variable MT flip angles (FAs) and off-resonance frequencies. A two-pool exchange model and dictionary matching were used to quantify the pool size ratio (PSR) and bound pool T2 relaxation ((Formula presented.)). The signal model was developed and validated using 25 MTw images on a bovine serum albumin (BSA) phantom and in vivo human thigh muscle. A protocol with five MTw images was optimized for single breath-hold cardiac qMT imaging. The proposed sequence was tested in 10 healthy subjects and 5 patients with myocardial fibrosis and compared to late gadolinium enhancement (LGE). Results: PSR values in the BSA phantom were within the confidence interval of previously reported values (concentration 10% BSA = 5.9 ± 0.1%, 15% BSA = 9.4 ± 0.2%). PSR and (Formula presented.) in thigh muscle were also in agreement with literature (PSR = 10.9 ± 0.3%, (Formula presented.) = 6.4 ± 0.4 us). In 10 healthy subjects, global left ventricular PSR was 4.30 ± 0.65%. In patients, PSR was reduced in areas associated with LGE (remote: 4.68 ± 0.70% vs. fibrotic: 3.12 ± 0.78 %, n = 5, P <.002). Conclusion: In vivo model-based qMT mapping of the heart was performed for the first time, with promising results for non-contrast enhanced assessment of myocardial fibrosis.

AB - Purpose: To develop a novel gadolinium-free model-based quantitative magnetization transfer (qMT) technique to assess macromolecular changes associated with myocardial fibrosis. Methods: The proposed sequence consists of a two-dimensional breath-held dual shot interleaved acquisition of five MT-weighted (MTw) spoiled gradient echo images, with variable MT flip angles (FAs) and off-resonance frequencies. A two-pool exchange model and dictionary matching were used to quantify the pool size ratio (PSR) and bound pool T2 relaxation ((Formula presented.)). The signal model was developed and validated using 25 MTw images on a bovine serum albumin (BSA) phantom and in vivo human thigh muscle. A protocol with five MTw images was optimized for single breath-hold cardiac qMT imaging. The proposed sequence was tested in 10 healthy subjects and 5 patients with myocardial fibrosis and compared to late gadolinium enhancement (LGE). Results: PSR values in the BSA phantom were within the confidence interval of previously reported values (concentration 10% BSA = 5.9 ± 0.1%, 15% BSA = 9.4 ± 0.2%). PSR and (Formula presented.) in thigh muscle were also in agreement with literature (PSR = 10.9 ± 0.3%, (Formula presented.) = 6.4 ± 0.4 us). In 10 healthy subjects, global left ventricular PSR was 4.30 ± 0.65%. In patients, PSR was reduced in areas associated with LGE (remote: 4.68 ± 0.70% vs. fibrotic: 3.12 ± 0.78 %, n = 5, P <.002). Conclusion: In vivo model-based qMT mapping of the heart was performed for the first time, with promising results for non-contrast enhanced assessment of myocardial fibrosis.

KW - cardiac

KW - fibrosis

KW - gadolinium-free

KW - magnetization transfer

KW - quantitative mapping

UR - http://www.scopus.com/inward/record.url?scp=85096773293&partnerID=8YFLogxK

U2 - 10.1002/mrm.28577

DO - 10.1002/mrm.28577

M3 - Article

C2 - 33201524

AN - SCOPUS:85096773293

SN - 0740-3194

VL - 85

SP - 2069

EP - 2083

JO - Magnetic Resonance in Medicine

JF - Magnetic Resonance in Medicine

IS - 4

ER -