Adrenal Imaging

Imaging of the adrenal gland in small animals has changed over the past 10 years. Radiographs have historically been a viable imaging tool, but because of their low specificity and sensitivity, other modalities are now considered more clinically useful. As a first-line imaging tool, ultrasonography is very useful. It can define the normal adrenal gland in size, shape, and echogenicity; adrenal mass lesions are also easily discerned by ultrasonography. In cases of complex adrenal lesions, especially masses that may exhibit vascular invasion, the author often uses contrast-enhanced computed tomography.

The normal adrenal gland is approximately 2 cm in length and up to 0.75 cm in width across the pole; it is best described as a bilobed gland with a thin center section, or isthmus, and two prominent poles. An enlarged adrenal gland can result from enlargement of the gland itself or from a mass within the gland.

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