Adrenal gland

The adrenal (suprarenal) glands are paired organs of the endocrine system, often asymmetric in shape. 

Each gland is enclosed in the perirenal fascia and each has a body and two limbs: a medial limb and a lateral limb. However, the right adrenal gland is usually more pyramidal in shape while the left adrenal gland is more crescentic 7

The right adrenal gland has a maximum width of 6.1 mm and the left adrenal gland has a maximum width of 7.9 mm 6. Proportionately, the adrenal size is larger in neonates and infants, being almost one-third of the size of the kidney 2-4

The adrenal gland consists of two portions: an outer cortex and an inner medulla. The gland is covered by a collagenous capsule.

The cortex is subdivided into three zones (from outer to inner) 5,7:

  1. zona glomerulosa
  2. zona fasciculata
  3. zona reticularis

The medulla produces catecholamines (adrenaline, noradrenaline) as well as dopamine. 

The adrenal glands lie superior and anteromedial to the kidneys.

  • lymphatics are contained within the capsule and drain to the para-aortic nodes 7,9
  • post synaptic fibres from coeliac, aorticorenal and renal ganglia
  • presynaptic fibres from abdominopelvic splanchnic nerves 7
  • lying down adrenal sign 8
    • takes on a flattened appearance
    • often in the presence of a pelvic kidney or renal agenesis
  • adrenal gland hypoplasia or agenesis 8
  • accessory adrenal rests
    • often near adrenal glands but may be found anywhere in the abdomen, pelvis or scrotum 9
  • horseshoe adrenal gland
  • anterior transverse scanning is the best approach but the adrenal glands are often difficult to see 6:
    • left adrenal gland seen ~40% at least once during scan
    • right adrenal gland seen ~80% at least once during scan
  • left adrenal gland is more difficult to visualise than the right because it is often posterior to the stomach and obscured by gas; this can be overcome by 6
    • intercostal scanning in the posterior axillary line
    • scanning through the spleen and left kidney with the left side of the patient elevated

The adrenal glands enhance after contrast administration to approximately 50-60 HU. Hyperenhancement of the adrenal gland is concerning for hypovolaemic shock.

  • located superior and anteromedial to the upper pole of the right kidney
  • appears as a linear, V-shape or comma-shape 1
  • located superior and anteromedial to the upper pole of the left kidney
  • appears as a triangular or Y-shape 1
Anatomy: Abdominopelvic

Anatomy: Abdominopelvic

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Article information

rID: 16568
System: Urogenital
Section: Anatomy
Synonyms or Alternate Spellings:
  • Adrenal glands
  • Suprarenal gland
  • Suprarenal glands
  • Adrenal gland anatomy
  • Adrenal anatomy
  • Suprarenal anatomy

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Cases and figures

  • Figure 1
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  • Figure 2: adrenal glands highlighted in yellow
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  • Case 1: normal CT anatomy
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  • Renal Ultrasound
    Case 2: pancake adrenal gland
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