Mouse myocardial first‐pass perfusion MR imaging

Abstract

A first-pass myocardial perfusion sequence for mouse cardiac MRI is presented. A segmented ECG-triggered acquisition combined with parallel imaging acceleration was used to capture the first pass of a Gd-DTPA bolus through the mouse heart with a temporal resolution of 300-400 msec. The method was applied in healthy mice (N 5 5) and in mice with permanent occlusion of the left coronary artery (N 5 6). Baseline semiquantitative perfusion values of healthy myocardium showed excellent reproducibility. Infarct regions revealed a significant decrease in the semiquantitative myocardial perfusion values (0.05 6 0.02) compared to remote myocardium (0.20 6 0.04). Myocardial areas of decreased perfusion correlated well to infarct areas identified on the delayed-enhancement scans. This protocol is a valuable addition to the mouse cardiac MRI toolbox for preclinical studies of ischemic heart disease.

Distribution of lipid-based nanoparticles to infarcted myocardium with potential application for MRI-monitored drug delivery

“…Cine MR images were acquired with a single-slice FLASH sequence (TR = 7 ms, TE= 1.8 ms, FA=15 o , FOV= 3x3 cm 2 , matrix=192x192, NEX = 6, slice thickness= 1 mm, number of cardiac frames= [13][14][15][16][17][18]. Two long-axis oriented slices and 9 to 11 slices from apex to base in short-axis orientation were recorded to analyze global and regional cardiac morphology and function.…”

“…These drawbacks might be overcome by enclosing the therapeutic compound into a nanoparticulate carrier, which specifically accumulates in the infarcted tissue by exploiting its ability to extravasate from the blood at sites with damaged leaky vascular endothelium [7,11,12]. Nevertheless, in acute non-reperfused MI, the infarct area is very poorly perfused, making efficient local delivery challenging [13]. In chronic MI, perfusion is partially restored by angiogenesis [3].…”

State-of-the-Art Methods for Evaluation of Angiogenesis and Tissue Vascularization

“…Regional tissue perfusion can be assessed with MR imaging after administration of gadolinium-based contrast agents 215 or with noncontrast imaging approaches that apply arterial spin labeling. 216 Some attempts at molecular imaging of angiogenesis have been made, including αvβ3-targeted nanoparticles for MR imaging, 203 although the MR approach in general lacks sensitivity for targeted molecular imaging.…”

The retrobulbar sinus is superior to the lateral tail vein for the injection of contrast media in small animal cardiac imaging

“…Recent technical advances in detector technology and image reconstruction algorithms indicate that cardiac perfusion imaging in small rodents is possible, with the newest generation hardware allowing for the evaluation of animal models of cardiac diseases in a preclinical environment using dedicated small animal scanners. [1][2][3] The following considerations will be restricted to mice due to their extensive usage in preclinical research and the availability of a multitude of cardiac disease models in these animals. [4][5][6][7] However, a direct translation of clinical scan protocols into preclinical practice is difficult due to the contrast agents used.…”