7029 Changes In Adrenal Gland Size Seen By Linear Assessment On Routine Abdominal CT During Critical Illness

Abstract Disclosure: D.R. Vangipuram: None. N. Bhagat: None. R. Borkar: None. N.T. Mazengia: None. S. Williams, MD: None. S.K. Majumdar: None. Introduction: During acute stress, the hypothalamus-pituitary-adrenal (HPA) axis is activated, ultimately releasing adrenocorticotropic hormone (ACTH) from the pituitary gland, which stimulates cortisol synthesis and release from the adrenal gland. During this process, ACTH also increases adrenal blood flow which may result in noticeable changes in adrenal gland size on imaging. A previous study compared adrenal gland volume in patients with and without sepsis and concluded that adrenal gland volume was found to be nearly double in sepsis compared with patients without sepsis(1). Another study that evaluated adrenal gland size on MDCT, to provide normal values for volumetry and linear dimensions, found a concordance between volumetric and linear assessment (by cumulative width), though volumetry was more reproducible(2). Method: This is a retrospective study that included 50 adult patients (age 18 and over) who underwent a non-contrast or contrast CT scan of the abdomen within 5 years prior to admission to the Intensive Care Unit (ICU) with any critical illness, and then had another CT of the abdomen during the admission to the ICU. We measured the maximum width of the body (corpus) and that of the medial and lateral limbs of both the adrenal glands, perpendicular to the long axis, as seen on CT. The total (cumulative) width was calculated by adding the width of the corpus and both the limbs of each adrenal gland. The measurements were made by two different radiologists, who were blinded both to the before/after ICU admission CTs, and to each other’s measurements. Results: There was concordance in the measurements made by both the radiologists. We used the averages of both their measurements for analysis. The mean cumulative width of each adrenal gland, i.e., corpus+medial limb+lateral limb (in mm), was: Right adrenal before ICU admission 13.52 (± 3.20); during ICU admission 13.24 (± 3.13); p 0.444. Left adrenal before ICU admission 16.03 (± 3.18); during ICU admission 15.12 (± 3.47); p 0.021. Conclusion: There was a statistically significant decrease in the size of the left adrenal gland during critical illness, but no significant change in the right. Our findings do not suggest an increase in adrenal gland size during ICU admission. References: 1. Nougaret S, Jung B, Aufort S, Chanques G, Jaber S, Gallix B. Adrenal gland volume measurement in septic shock and control patients: a pilot study. Eur Radiol. 2010 Oct;20(10):2348-57. doi: 10.1007/s00330-010-1804-9. Epub 2010 Jun 4. PMID: 20521055. 2. Schneller J, Reiser M, Beuschlein F, Osswald A, Pallauf A, Riester A, et al. Linear and volumetric evaluation of the adrenal gland--MDCT-based measurements of the adrenals. Acad Radiol. 2014 Nov;21(11):1465-74. doi: 10.1016/j.acra.2014.06.008. PMID: 25300724. Presentation: 6/3/2024