Linear and Volumetric Evaluation of the Adrenal Gland - MDCT-Based Measurements of the Adrenals

Rationale and Objectives: The purpose of this study was to provide normal values of volumetry and linear dimensions of adrenal glands. Materials and Methods: Contrast-enhanced multidetector computed tomography scans of 105 patients were evaluated in this retrospective study. Imaging software was used both to measure the adrenal gland volume and to determine linear dimensions and density. For interobserver reliability, determination was repeated by a second reader in 10 patients selected at random. Results: The mean adrenal volume was 4.84 (+/- 1.67) cm(3) on the left side and 3.62 (+/- 1.23) cm(3) on the right side. The total adrenal volume was mainly influenced by body weight (P < .001) and gender with women having smaller glands on average. The total width of the adrenal gland was 15.80 (+/- 3.05) mm on the right side and 18.96 (+/- 3.37) mm on the left side. There was a significant correlation between volume and linear measurements (P < .001). The mean density of both adrenal glands was 32.66 (+/- 19.64) HU. Overall, interobserver reliability was high for volumetry (left adrenal, r = 0.98; right adrenal, r = 0.90) and low for linear dimensions. Conclusions: Normal data for volumetry and linear dimensions are provided. There is a concordance between volumetric and linear assessment. However, volumetry is more reproducible.