Investigation of the Relationship Between Adrenal Gland Signal Intensity and Age in Whole-body MRI/DWIBS

To identify factors influencing adrenal signal intensity in whole-body magnetic resonance imaging/diffusion-weighted whole-body imaging with background body signal suppression (MRI/DWIBS).

This retrospective study included patients who underwent whole-body MRI/DWIBS at our institution between April 2019 and April 2025 with no malignant tumor or history of a malignant tumor. Adrenal signal intensity and gland area were measured and analyzed according to sex and age.

The study included 22 male patients (average age of 58.2±11.7) and 38 female patients (average age of 55.9±15.4). The maximum signal intensity (max value) of the left adrenal gland on diffusion-weighted imaging was 1,885.5±352.0, and the mean gland area was 1,198±435.0 mm² in male patients, and 1,517.1±429.5 and 760.5±325.6 mm², respectively, in female patients. The median values for max value of the left adrenal gland on diffusion-weighted imaging were significantly larger in male patients (male: 1855 vs. female: 1,472, p<0.01). The median value for adrenal gland area was significantly larger in male patients (male: 1,159 mm² vs. female: 768.5 mm², p<0.01). Among female patients, those aged <40 years had a significantly lower median max value and adrenal gland area compared to those aged ≥40 years (<40 years: 1,004 vs. ≥40 years: 1,603, p<0.01 and <40 years: 478 mm² vs. ≥40 years: 834 mm², p=0.017, respectively).

Adrenal gland signal intensity and gland size on whole-body DWIBS are significantly higher in males than in females. In females, both signal intensity and adrenal area increase with age, suggesting age-related physiological or hormonal influences on adrenal gland characteristics.