Comparison of T1-enhancing and magnetic susceptibility magnetic resonance contrast agents for demarcation of the jeopardy area in experimental myocardial infarction.
OBJECTIVE
This study compared the areas demarcated by a T1-enhancing agent, Gd-DTPA-BMA, and a magnetic susceptibility agent, Dy-DTPA-BMA, with 201thallium autoradiography (indicator of perfusion) and postmortem histochemical staining with triphenyltetrazolium chloride (TTC)(indicator of infarction).


METHODS
Thirteen rats were subjected to coronary artery occlusion for 3 to 4 hours before acquisition of four sets of electrocardiogram-gated spin-echo magnetic resonance (MR) images: T1-weighted images before and after 0.2 mmol/kg Gd-DTPA-BMA; and T2-weighted images before and after 0.3 mmol/kg Dy-DTPA-BMA. After MR imaging, intravenous 201thallium delineated the area of decreased myocardial perfusion. At autopsy, TTC staining delineated the area of myocardial infarction.


RESULTS
A myocardial region in the distribution of the occluded artery was delinated as a hyperintense area ("hot-spot") by Dy-DTPA-BMA and as a hypointense area ("cold-spot") by Gd-DTPA-BMA. The hyperintense area demarcated by Dy-DTPA-BMA (51 +/- 3% of the area of the midequitorial slice of the left ventricle) showed a closer relationship to the area of decreased myocardial perfusion (jeopardized area) (46 +/- 3%), determined by 201thallium autoradiography, than the area of myocardial infarction (36 +/- 4%), determined by histochemical staining. However, the hypointense area demarcated by Gd-DTPA-BMA (29 +/- 2%) did not relate as closely to the area of decreased myocardial perfusion (slope = 0.54) or the area of myocardial infarction (r = 0.46).


CONCLUSIONS
The abnormal myocardial area delineated by the magnetic susceptibility agent showed a closer relationship to the area of deficient myocardial perfusion (jeopardy area) after coronary occlusion than that defined by T1-enhancing contrast media.
Yu
K K
KK
Department of Radiology, University of California, San Francisco 94143.
Saeed
M
M
Wendland
M F
MF
Dae
M W
MW
Velasquez-Rocha
S
S
Derugin
N
N
Higgins
C B
CB
D000818:Animals; D001345:Autoradiography; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D008279:Magnetic Resonance Imaging; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D015588:Observer Variation; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling; D013778:Tetrazolium Salts; D013794:Thallium Radioisotopes
D003287:Contrast Media; D009942:Organometallic Compounds; D013778:Tetrazolium Salts; D013794:Thallium Radioisotopes; C061756:sprodiamide; D004369:Pentetic Acid; C009591:triphenyltetrazolium; C064925:gadodiamide; D019786:Gadolinium DTPA