MR Angiography of the HeadNeck Vascular System in Mice on a Clinical MRI System

Abstract EN

Background.

Magnetic resonance angiography (MRA) represents a clinical reference standard for the in vivo assessment of the vasculature.

In this study, the potential of non-contrast-enhanced and contrast-enhanced angiography of the head/neck vasculature in mice on a clinical MR imaging system was tested.

Methods.

All in vivo magnetic resonance imaging was performed with a 3T clinical system (Siemens).

Non-contrast-enhanced (time-of-flight, TOF) and contrast-enhanced angiography (gadofosveset-trisodium, GdT) were performed in C57BL/6J mouse strain.

Lumen-to-muscle ratios (LMRs) and area measurements were assessed.

Histology was performed as reference standard of all relevant vascular structures.

Results.

A close correlation between TOF (R2 = 0.79; p<0.05) and contrast-enhanced (GdT) angiography (R2 = 0.92; p<0.05) with histological area measurements was found.

LMRs were comparable between both sequences.

Regarding interobserver reproducibility, contrast-enhanced (GdT) angiography yielded a smaller 95% confidence interval and a closer interreader correlation compared to non-contrast-enhanced (TOF) measurements (−0.73–0.89; R2 = 0.81 vs.

−0.55–0.56; R2 = 0.94).

Conclusion.

This study demonstrates that non-contrast-enhanced and contrast-enhanced angiographies of the head/neck vasculature of small animals can reliably performed on a clinical 3T MR scanner.

Contrast-enhanced angiography enables the visualization of vascular structures with higher intravascular contrast and higher reproducibility.