Premium
Inversion recovery EPI of bolus transit in rat myocardium using intravascular and extravascular gadolinium‐based MR contrast media: Dose effects on peak signal enhancement
Author(s) -
Wendland Michael F.,
Saeed Maythem,
Yu Kyle K.,
Roberts Timothy P. L.,
Lauerma Kirsi,
Derugin Nikita,
Varadarajan John,
Watson Alan D.,
Higgins Charles B.
Publication year - 1994
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910320307
Subject(s) - gadolinium , chemistry , bolus (digestion) , nuclear magnetic resonance , nuclear medicine , medicine , physics , organic chemistry
Inversion recovery gradient recalled echo planar imaging (TI/ TR / TE = 700/2000/10 ms) was used to dynamically monitor the first pass of an intravascular (GdDOTA‐polylysine) and an extravascular (GdDTPA‐BMA) contrast agent through normal rat myocardium. It was found that myocardial enhancement increased with dose of the intravascutar agent to a limiting value of ∼50% of fully relaxed intensity, consistent with enhancement of 40% of myocardial water content during the first pass. Larger doses produced no further increase in peak response. On the other hand, the extravascular agent caused incrementally increased enhancement throughout the dose range examined to a final value of 68 ± 2% of fully relaxed intensity. The profile of dose dependence for both agents was inconsistent with monoexponential T 1 relaxation. It was concluded that (a) compartmentalization of myocardial water combined with restricted myocardial water diffusion limits the peak response during bolus transit; (b) extraction of the extravascular agent during transit elevates the peak response over that obtained from agent confined to the vascular volume; and (c) models that assume simple monoexponential r, relaxation to derive timedensity curves do not adequately describe the relationship between changes in signal intensity, R 1 and contrast concentration.