Ultrasonographic Adrenal Gland Measurements in Healthy Yorkshire Terriers and Labrador Retrievers

Abstract

An upper threshold of 7.4 mm for maximal adrenal gland diameter is commonly used to detect pituitary-dependent hyperadrenocorticism ultrasonographically in dogs. There is a substantial overlap between adrenal gland diameter of healthy dogs and of those with pituitary-dependent hyperadrenocorticism. The aim of this study is to determine the measurements of both adrenal glands, in particular, of the height at the caudal glandular pole in a longitudinal plane, in the Labrador retriever and Yorkshire terrier, two breeds widely represented in the population suspected of hyperadrenocorticism. Seventeen Labrador retrievers and 24 Yorkshire terriers considered healthy were included in the study. Adrenal gland measurements were taken on static images and comprised in measurements of the length in a longitudinal plane (L), of the height at the cranial (CrHLG) and caudal pole (CdHLG) in a longitudinal plane and in a transverse plane (CrHTR and CdHTR, respectively), and of the width at the cranial and caudal poles in a transverse plane (CrWTR and CdWTR, respectively). This study established new upper thresholds for the left and right height at the caudal pole measured in a longitudinal plane: 7.9 mm (left) and 9.5 mm (right) for the Labrador retrievers and 5.4 mm (left) and 6.7 mm (right) for the Yorkshire terriers. All the measurements were significantly different between the two breeds. There was a significant relationship between CdHTR and CdHLG, and the age of the dogs for both breeds.

Ultrasonographic Evaluation of Adrenal Gland Size Compared to Body Weight in Normal Dogs

“…Whether or not a relationship exists between ultrasonographically obtained adrenal gland measurements and body weight has not been clearly documented in previous reports. Discrepancies exist among earlier studies that attempted to document an association between adrenal gland measurements and body weight using ultrasonography, but Bertolini et al found no relationship between the volume of the adrenal glands and body weight using computed tomography …”

“…A wide range of values have been documented by previous studies with regard to normal ultrasonographic size (length, width, and thickness) of the adrenal glands in healthy dogs. Adrenal gland measurements in normal dogs have been reported to vary from 0.91 to 5.02 cm for length, from 0.19 to 1.74 cm for width, and from 0.17 to 1.07 cm for thickness/height . Additionally, although dogs with hyperadrenocorticism have adrenal gland measurements significantly greater than those of normal dogs and dogs with hypoadrenocorticism have adrenal gland measurements significantly less than those of normal dogs, an overlap in the range of measurements of dogs with either disease and normal dogs is present.…”

Acoustic radiation force impulse (ARFI) elastography of adrenal glands in healthy adult dogs

“…This technique is described in the literature as a useful imaging modality in the diagnostic workup of canine patients with adrenal neoplasms of the cortex and medulla, hypoadrenocorticism or hyperadrenocorticism and aiding in differentiation of pituitarydependent hyperadrenocorticism (PDH) from adrenal-dependent hyperadrenocorticism (ADH) (Douglass et al 1997;Choi et al 2011;Chalus et al 2013).…”

Safety of percutaneous ultrasound‐guided fine‐needle aspiration of adrenal lesions in dogs: Perception of the procedure by radiologists and presentation of 50 cases

“…From each US report and available US images, the following criteria were collected in an excel spreadsheet and reviewed: side and size (mm) of adrenal lesions, the dimension (mm) of the contralateral AG, echogenicity (hypoechoic, hyperechoic, or isoechoic to adjacent adipose tissue), echotexture (homogeneous, heterogeneous) and contours of the lesion (smooth or irregular), presence or absence of mineralization, and finally presence or absence of vascular invasion . The contralateral AG was considered atrophied when its maximal thickness was less than 5.0 mm . Computed tomographic reports, when available, were also reviewed, in order to complete the diagnostic workup.…”

“…25,26 The contralateral AG was considered atrophied when its maximal thickness was less than 5.0 mm. [46][47][48] Computed tomographic reports, when available, were also reviewed, in order to complete the diagnostic workup. The revision of the US and CT images was at the discretion of the radiologist who submitted the case, if the report was not complete enough to answer to aforementioned criteria.…”