Acute myocardial ischemia: MR imaging with Mn-TP.
Cardiac-gated magnetic resonance (MR) imaging was performed in rats to determine the effects of manganese ethylenediaminetetraphosphonate (TP). Ten normal rats received Mn-TP in a dose of 50 mumol/kg through a tail-vein injection. Spin-echo MR images were obtained before and every 10 minutes after Mn-TP injection for 1 hour. Cardiac signal intensity (SI) increased more than 70% after Mn-TP injection and remained nearly unchanged 1 hour after injection. Myocardial T1 was 517 +/- 49 msec in eight control rats and 282 +/- 61 msec (P less than .001) in six rats 81 +/- 0 minutes after injection. Nine rats underwent occlusion of the left anterior descending coronary artery prior to MR imaging. Images were obtained before and 15, 30, and 60 minutes after Mn-TP injection. In normal myocardium, SI increased up to 82% and remained elevated for 1 hour. In ischemic myocardium, SI rose 11%, leading to a marked contrast between the two tissue zones. T1 was also different in the two regions: In normal tissue, it was 206 msec +/- 54; in ischemic tissue, 338 +/- 82 (P less than .001). With T1-weighted MR imaging, Mn-TP showed a potential for delineating the jeopardized area after acute myocardial ischemia.
Pflugfelder
P W
PW
Department of Radiology, University of California, San Francisco 94143.
Wendland
M F
MF
Holt
W W
WW
Quay
S C
SC
Worah
D
D
Derugin
N
N
Higgins
C B
CB
D000818:Animals; D003250:Constriction; D003287:Contrast Media; D003327:Coronary Disease / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008345:Manganese; D009943:Organophosphorus Compounds; D051381:Rats; D013997:Time Factors
D003287:Contrast Media; D009943:Organophosphorus Compounds; C018940:(ethylenedinitrilo)-tetramethylenephosphonic acid; D008345:Manganese