Characterization of the ultrashort-TE (UTE) MR collagen signal.
Although current cardiovascular MR (CMR) techniques for the detection of myocardial fibrosis have shown promise, they nevertheless depend on gadolinium-based contrast agents and are not specific to collagen. In particular, the diagnosis of diffuse myocardial fibrosis, a precursor of heart failure, would benefit from a non-invasive imaging technique that can detect collagen directly. Such a method could potentially replace the need for endomyocardial biopsy, the gold standard for the diagnosis of the disease. The objective of this study was to measure the MR properties of collagen using ultrashort TE (UTE), a technique that can detect short T2* species. Experiments were performed in collagen solutions. Via a model of bi-exponential T2* with oscillation, a linear relationship (slope = 0.40 ± 0.01, R(2) = 0.99696) was determined between the UTE collagen signal fraction associated with these properties and the measured collagen concentration in solution. The UTE signal of protons in the collagen molecule was characterized as having a mean T2* of 0.75 ± 0.05 ms and a mean chemical shift of -3.56 ± 0.01 ppm relative to water at 7 T. The results indicated that collagen can be detected and quantified using UTE. A knowledge of the collagen signal properties could potentially be beneficial for the endogenous detection of myocardial fibrosis.
Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.|Cardiovascular Sciences Collaborative Program, University of Toronto, Toronto, ON, Canada.|Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada.
Adrienne G
AG
Siu
Keenan Research Center, Li Ka Shing Knowledge Institute, Toronto, ON, Canada.
Andrew
A
Ramadeen
Keenan Research Center, Li Ka Shing Knowledge Institute, Toronto, ON, Canada.
Xudong
X
Hu
Center for Modeling Human Disease, Toronto Center for Phenogenomics, Toronto, ON, Canada.
Lily
L
Morikawa
Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.|Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada.
Li
L
Zhang
Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.|Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada.
Justin Y C
JY
Lau
Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.|Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada.
Garry
G
Liu
Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.|Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada.
Mihaela
M
Pop
Cardiovascular Sciences Collaborative Program, University of Toronto, Toronto, ON, Canada.|Keenan Research Center, Li Ka Shing Knowledge Institute, Toronto, ON, Canada.|Division of Cardiology, St. Michael's Hospital, Toronto, ON, Canada.
Kim A
KA
Connelly
Cardiovascular Sciences Collaborative Program, University of Toronto, Toronto, ON, Canada.|Keenan Research Center, Li Ka Shing Knowledge Institute, Toronto, ON, Canada.|Division of Cardiology, St. Michael's Hospital, Toronto, ON, Canada.
Paul
P
Dorian
Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.|Cardiovascular Sciences Collaborative Program, University of Toronto, Toronto, ON, Canada.|Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada.
Graham A
GA
Wright
D000818:Animals; D002417:Cattle; D024042:Collagen Type I / Q000737:chemistry*; D024061:Collagen Type III / Q000737:chemistry*; D004719:Endomyocardial Fibrosis / Q000175:diagnosis / Q000378:metabolism; D005240:Feasibility Studies; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D011522:Protons; D012996:Solutions
D024042:Collagen Type I; D024061:Collagen Type III; D011522:Protons; D012996:Solutions
UTE; collagen; endogenous contrast methods; myocardial fibrosis; relaxometry