Assessment of the accuracy of computed tomography for measurement of normal equine pituitary glands.
OBJECTIVE
To describe the anatomic features of the pituitary gland region in horses via computed tomography (CT) and determine the accuracy of CT for estimating normal equine pituitary gland dimensions.


METHODS
25 adult horses with no clinical signs of pituitary disease.


METHODS
Transverse CT images and gross transverse tissue sections were compared in 2 horses. Contrast-enhanced CT of the pituitary gland region was performed postmortem in 23 horses with 4 slice thickness and interval settings (10-mm contiguous or overlapping slices and 4-mm contiguous or overlapping slices). Gross and CT estimates of pituitary gland dimensions were compared via ANOVA. Accuracy of CT estimates was calculated with gross pituitary gland measurements as the known value.


RESULTS
Pituitary glands were located between the temporomandibular joints and had contrast enhancement. Mean gross dimensions were length, 2.11 cm; width, 2.16 cm; height, 0.98 cm; and volume, 2.66 cm3. Gross measurements and CT estimates of pituitary gland length from 10-mm contiguous and overlapping slices did not differ. Gross measurements and CT estimates of pituitary gland width from 4-mm contiguous and overlapping slices did not differ. Estimates of height and volume from all CT techniques differed from gross measurements. Accuracies for CT estimates were length, 88 to 99%; width, 81 to 92%; height, 58 to 71%; and volume, 43 to 55%.


CONCLUSIONS
Accuracy of estimates of pituitary gland dimension in horses varied with CT scanning technique; via CT estimates of length and width of glands were more accurate than estimates of height or volume.
McKlveen
Tori L
TL
Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061-0442, USA.
Jones
Jeryl C
JC
Sponenberg
D Phillip
DP
Scarratt
Kent
K
Ward
Daniel L
DL
Aardema
Charles H
CH
D000818:Animals; D003287:Contrast Media; D006736:Horses / Q000033:anatomy & histology*; D010902:Pituitary Gland / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D012016:Reference Values; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000662:veterinary*
D003287:Contrast Media