Ultrasound measurement of aortic diameters in rodent models of aneurysm disease.
BACKGROUND
This investigation was undertaken to evaluate transabdominal ultrasound (US) measurements of aortic diameters in rats and mice as a complementary method to video microscopy (VM), the current standard for assessing the diameter of rodent aortas.


METHODS
Aortic diameters were measured in 64 rats (n = 132 sets) and 12 mice (n = 36 sets) following experimental induction of aortic aneurysms. Diameters were measured at the renal vein, midinfrarenal aorta, and aortic bifurcation.


RESULTS
In the rat, anteroposterior (AP) US measurements were closely correlated with transverse VM measurements, with correlation coefficients ranging from 0.66 to 0.77 (P < 0.0001) for axial US images and 0.58 to 0.63 (P < 0.0001) for sagittal US images. In the mouse, significant correlation coefficients were 0.57 (P < 0.001) near the renal vein and 0.44 (P = 0.007) at the midinfrarenal aorta. Aortic diameters increased significantly with increasing animal age and weight (R = 0.40, P = 0.003 at the renal vein, R = 0.29, P = 0.04 in the midinfrarenal aorta, and R = 0.39, P = 0.004 at the aortic bifurcation), suggesting that weight matched rodents must be used to define aortic dimensions in treatment groups as opposed to repeated comparisons with baseline measurements in a growing rat.


CONCLUSIONS
Noninvasive aortic US measurements throughout the course of a rodent study of aneurysmal disease provide a practical alternative to VM for the repeated determinations of aortic diameters.
Knipp
Brian S
BS
Jobst Vascular Research Laboratories, Section of Vascular Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA.
Ailawadi
Gorav
G
Sullivan
Vita V
VV
Roelofs
Karen J
KJ
Henke
Peter K
PK
Stanley
James C
JC
Upchurch
Gilbert R
GR
D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging*; D001835:Body Weight; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018715:Microscopy, Video; D051381:Rats; D017207:Rats, Sprague-Dawley; D012082:Renal Veins; D014463:Ultrasonography