title: Water-macromolecular proton magnetization transfer in infarcted myocardium: a method to enhance magnetic resonance image contrast.
abstract: Water proton nuclear magnetic resonance relaxation times and magnetization transfer (MT) parameters of rat hearts were studied 24 h or 4 weeks after ligation of the left coronary artery or sham operation. Compared with sham-operated controls, measured relaxation times (T1sat and T2) of both acute and chronic myocardial infarction increased. The MT effect significantly decreased in the infarcted myocardium. The changes in relaxation times and MT effect were significantly greater in chronic infarcts compared with acute infarcts. Improvements in calculated image contrast between normal and infarcted tissue were supported by images of ex vivo hearts with chronic infarction. Image contrast was increased at short echo times in the presence of macromolecular proton pool irradiation. Exploiting changes in tissue MT following myocardial infarction to enhance contrast between normal and infarcted tissue should allow improved identification and characterization of infarcted myocardium.
authors.affiliation: Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: T D
authors.initials: TD
authors.lastname: Scholz
authors.forename: R F
authors.initials: RF
authors.lastname: Hoyt
authors.forename: J R
authors.initials: JR
authors.lastname: DeLeonardis
authors.forename: T L
authors.initials: TL
authors.lastname: Ceckler
authors.forename: R S
authors.initials: RS
authors.lastname: Balaban
mesh_terms: D000818:Animals; D001834:Body Water / Q000737:chemistry; D001835:Body Weight; D002908:Chronic Disease; D006352:Heart Ventricles; D006859:Hydrogen; D007089:Image Enhancement / Q000379:methods*; D046911:Macromolecular Substances; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D009929:Organ Size; D011522:Protons; D051381:Rats; D017207:Rats, Sprague-Dawley; D014867:Water
chemical_list: D046911:Macromolecular Substances; D011522:Protons; D014867:Water; D006859:Hydrogen