Application of clinical scanners in rats: experimental carotid imaging using magnetic resonance imaging, spiral computed tomography, and color duplex ultrasound.
OBJECTIVE
Noninvasive small animal imaging allows for reduction of the required numbers of animals in research by providing the possibility of long-term follow-up at various time points. Additionally, correlation to the investigated respective human disease is possible as equivalent equipment is employed. The authors therefore evaluate feasibility and potential of color duplex sonography, computed tomography angiography (CTA), and magnetic resonance angiography (MRA) by the use of clinical scanners for carotid artery imaging in rats.


METHODS
Male Wistar rats (n = 17) were subjected to color duplex sonography, CTA, and MRA of the common carotid artery (CCA) and the carotid bifurcation. Clinical scanners were used for the experiments and optimal parameter settings evaluated accounting for the different size of the animals. The applied imaging methods were analyzed in regard to image quality and practicability in laboratory settings.


RESULTS
The CCA could be clearly displayed by all imaging modalities in all rats. Duplex sonography provided distinct images and reproducible basic functional information. CTA and MRA provided distinct images of the CCA and the carotid bifurcation in both axial and reconstructed 3-dimensional images. The authors further describe different indications for these imaging methods regarding spatial resolution, acquisition times, possible scanning range, and application of contrast agent.


CONCLUSIONS
Color duplex sonography, CTA, and MRA are all feasible methods for imaging of the carotid arteries in rats. Images of sufficient clarity and resolution could be obtained by the use of clinical scanners, yielding information about vessel size, direction of blood flow, and adjacent structures. Further studies need to be performed that address investigations of pathological conditions such as flow disturbances or vessel stenosis.
Fehm
Nando Percy
NP
Department of Neurology, University of Regensburg, Universitätsstrasse 84, 93053 Regensburg, Germany. Nando.Fehm@medbo.de
Vatankhah
Bijan
B
Dittmar
Michael S
MS
Retzl
Gerald
G
Schuierer
Gerhard
G
Horn
Markus
M
Schlachetzki
Felix
F
D000818:Animals; D002339:Carotid Arteries / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005240:Feasibility Studies; D018810:Magnetic Resonance Angiography / Q000295:instrumentation*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D036542:Tomography, Spiral Computed / Q000295:instrumentation*; D018615:Ultrasonography, Doppler, Color / Q000295:instrumentation*