Regional myocardial blood volume and flow: first-pass MR imaging with polylysine-Gd-DTPA.
The authors investigated the utility of an intravascular magnetic resonance (MR) contrast agent, poly-L-lysine-gadolinium diethylenetriaminepentaacetic acid (DTPA), for differentiating acutely ischemic from normally perfused myocardium with first-pass MR imaging. Hypoperfused regions, identified with microspheres, on the first-pass images displayed significantly decreased signal intensities compared with normally perfused myocardium (P < .0007). Estimates of regional myocardial blood content, obtained by measuring the ratio of areas under the signal intensity-versus-time curves in tissue regions and the left ventricular chamber, averaged 0.12 mL/g +/- 0.04 (n = 35), compared with a value of 0.11 mL/g +/- 0.05 measured with radiolabeled albumin in the same tissue regions. To obtain MR estimates of regional myocardial blood flow, in situ calibration curves were used to transform first-pass intensity-time curves into content-time curves for analysis with a multiple-pathway, axially distributed model. Flow estimates, obtained by automated parameter optimization, averaged 1.2 mL/min/g +/- 0.5 (n = 29), compared with 1.3 mL/min/g +/- 0.3 obtained with tracer microspheres in the same tissue specimens at the same time. The results represent a combination of T1-weighted first-pass imaging, intravascular relaxation agents, and a spatially distributed perfusion model to obtain absolute regional myocardial blood flow and volume.
Wilke
N
N
Department of Radiology, University of Minnesota, Minneapolis 55455, USA.
Kroll
K
K
Merkle
H
H
Wang
Y
Y
Ishibashi
Y
Y
Xu
Y
Y
Zhang
J
J
Jerosch-Herold
M
M
Mühler
A
A
Stillman
A E
AE
D000818:Animals; D001810:Blood Volume; D003287:Contrast Media; D003326:Coronary Circulation; D004285:Dogs; D019786:Gadolinium DTPA; D006321:Heart / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D017202:Myocardial Ischemia / Q000175:diagnosis; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives*; D011107:Polylysine / Q000031:analogs & derivatives*; D011877:Radionuclide Imaging
D003287:Contrast Media; D009942:Organometallic Compounds; C068674:polylysine-(Gd-DTPA); D011107:Polylysine; D004369:Pentetic Acid; D019786:Gadolinium DTPA