In vivo MR-angiography for the assessment of aortic aneurysms in an experimental mouse model on a clinical MRI scanner: Comparison with high-frequency ultrasound and histology.

Christian H P Jansen,Julia Brangsch,René M Botnar,Carolin Reimann,Marcus R Makowski

doi:10.1371/journal.pone.0178682

Abstract

BackgroundMR-angiography currently represents one of the clinical reference-standards for the assessment of aortic-dimensions. For experimental research in mice, dedicated preclinical high-field MRI scanners are used in most studies. This type of MRI scanner is not available in most institutions. The aim of this study was to evaluate the potential of MR-angiography performed on a clinical MR scanner for the assessment of aortic aneurysms in an experimental mouse model, compared to a preclinical high-resolution ultrasound imaging system and histopathology.MethodsAll in vivo MR imaging was performed with a clinical 3T MRI system (Philips Achieva) equipped with a clinical gradient system in combination with a single-loop surface-coil (47 mm). All MR sequences were based on clinically used sequences. For ultrasound, a dedicated preclinical high-resolution system (30 MHz linear transducer, Vevo770, VisualSonics) was used. All imaging was performed with an ApoE knockout mouse-model for aortic aneurysms. Histopathology was performed as reference-standard at all stages of aneurysm development.ResultsMR-angiography on a clinical 3T system enabled the clear visualization of the aortic lumen and aneurysmal dilation at different stages of aneurysm development. A close correlation (R2 = 0.98; p < 0.001) with histological area measurements was found. Additionally, a good agreement between MR and ultrasound area measurements in systole (R2 = 0.91; p < 0.001) and diastole (R2 = 0.94; p < 0.001) were measured. Regarding interobserver reproducibility, MRI measurements yielded a smaller 95% confidence interval and a closer interreader correlation compared to ultrasound measurements (-0.37–0.46; R2 = 0.97 vs. -0.78–0.88; R2 = 0.87).ConclusionThis study demonstrates that MR-angiography, performed on a clinical 3T MR scanner, enables the reliable detection and quantification of the aortic dilatation at different stages of aneurysm development in an experimental mouse model.

Highlights

Cardiovascular diseases, including aortic aneurysms, currently represent the main cause of death in Western societies
There are MR-angiography on a clinical 3T system enabled the clear visualization of the aortic lumen and aneurysmal dilation at different stages of aneurysm development
In vivo MR angiography on a clinical MR scanner for the assessment of aortic aneurysms no financial or other relations that could lead to a conflict of interest

Summary

Introduction

Cardiovascular diseases, including aortic aneurysms, currently represent the main cause of death in Western societies. The incidence of abdominal aortic aneurysms is estimated to be around 5% in the general population older than 50 years [3, 4]. The development of abdominal aortic aneurysms is associated with different causes, which include aortic infection, disorders of connective tissues and traumatic events [5, 6]. Abdominal aortic aneurysms are associated with a progressive dilation of the aortic lumen. For experimental research in mice, dedicated preclinical highfield MRI scanners are used in most studies. The aim of this study was to evaluate the potential of MR-angiography performed on a clinical MR scanner for the assessment of aortic aneurysms in an experimental mouse model, compared to a preclinical high-resolution ultrasound imaging system and histopathology

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