Ultrasonographic Characteristics of the Adrenal Glands in Dogs With Pituitary‐Dependent Hyperadrenocorticism: Comparison With Normal Dogs

Abstract

Ultrasonographic evaluation of the adrenal glands was performed in 10 dogs with pituitary-dependent hyperadreno-corticism (PDH) and in 10 age-and weight-matched healthy control dogs. Thickness, shape, and echogenicity were determined for each adrenal gland. Adrenal thickness in dogs with PDH (median, 10 mm-left; 8.5 mm-right) was significantly greater than thickness in control dogs (median, 6 mm-left; 6 mm-right). Other ultrasonographic characteristics associated with PDH included bilaterally symmetrical adrenomegaly and maintenance of normal adrenal shape. Adrenal echogenicity was homogeneous and less than that yperadrenocorticism is a common canine endocrinopa

Accuracy of an Adrenocorticotropic Hormone (ACTH) Immunoluminometric Assay for Differentiating ACTH‐Dependent from ACTH‐Independent Hyperadrenocorticism in Dogs

“…30,31 In dogs, none of the tests developed to date for determining the origin of canine HAC, including endocrine and imaging procedures, is currently considered perfect. 10,11,13,19,20,28,32,33 Imaging techniques can sometimes fail to distinguish the cause of HAC, but are still essential for providing topographical information once a clear cause has been identified. Functional characterization of the corticotropic axis by endocrine testing should provide an obvious distinction, but until this study, all endocrine tests evaluated have produced a proportion of misclassified cases.…”

“…During the last 30 years, a number of imaging techniques and endocrine tests, including plasma ACTH measurement, have been developed for this purpose. [5][6][7][8][9][10][11][12][13][14] Over this period, techniques used for ACTH measure have changed from radioimmunoassay (RIA) [15][16][17] to immunoradiometric (IRMA) 18 and immunoluminometric assays (ILMA), 19 with concomitant improvements in the analytical sensitivity and specificity. Despite its widespread use, few surveys have evaluated the diagnostic accuracy of ACTH determination for investigations of the cause of Cushing's syndrome.…”

“…The use of adrenal symmetry to allocate dogs to the ADHAC group potentially is more problematic because no definitive criteria for symmetry have ever been defined, and ADHAC cases may be associated with variable degrees of asymmetry. 9,10 We used a conservative strategy, considering as ADHAC only dogs with adrenal glands exhibiting o20% asymmetry on adrenal imaging, with normal shape and normal echogenicity or attenuation. Many cases of ADHAC may have been excluded with this strategy.…”

Ultrasonographic Adrenal Gland Measurements in Clinically Normal Small Breed Dogs and Comparison with Pituitary-Dependent Hyperadrenocorticism

“…Ultrasonography has been determined to be a useful primary screening modality to identify abnormal adrenal glands, such as pituitary-dependent hyperadrenocorticism (PDH), adrenal neoplasms of the cortex and medulla and hypoadrenocorticism [2,3,7,[9][10][11][12][13]. Adrenal size has been used as the principal criterion for differentiating a normal adrenal gland from adrenal hyperplasia [2].…”

Magnetic Resonance Imaging Assessment of Pituitary Posterior Lobe Displacement in Dogs with Pituitary-Dependent Hyperadrenocorticism

“…The diagnosis of hyperadrenocorticism was also confirmed by an ACTH stimulation test. Pituitary-dependent hyperadrenocorticism was confirmed by detection of two equally sized enlarged adrenal glands on abdominal ultrasonography [3,10,11]. The mean age and weight of the PDH group were 9.4 ± 2.2 years old (mean ± SD) and 11.5 ± 6.1 kg, respectively.…”