A pilot study to assess the feasibility of measurement of adrenal gland volume by magnetic resonance imaging.
BACKGROUND
Repeated computed tomography (CT) assessment of the adrenal glands is associated with a significant radiation burden. The increasing capabilities of magnetic resonance (MR) volumetric analysis of the adrenals make this a potentially alternative technique in man.


OBJECTIVE
To determine whether MR imaging could be used to measure adrenal volume, and to determine the intra- and interobserver variation and repeatability of MR volume imaging of adrenals in healthy human subjects.


METHODS
This was a single-cohort, sequential design, three-part study involving four MRI examinations per subject following ethical approval and informed consent. Information was collected on four healthy subjects (three male and one female). Two different investigators estimated the area of the adrenal gland for each of the 3-mm contiguous slices (and consequently adrenal volume). In order to estimate inter- and intrareader variability, a repeated-measures mixed model was fitted with adrenal volume as the dependent variable. In order to estimate any bias between readers, Bland-Altman methodology was applied.


RESULTS
Intraobserver variation for adrenal gland volume is approximately 5% of a 3-cm(3 )adrenal gland. Interobserver variation is approximately 9% of a 3-cm(3) adrenal gland. Potential variation in measurement for adrenal volume from all sources equates to approximately 14% of a 3-cm(3) adrenal gland. Verification of image reading by a second investigator (consensus reading) reduces variability.


CONCLUSIONS
Analysis of adrenal gland volume using MRI is a potentially reliable technique that could be used to assess a pathological change in adrenal size.
Grant
Lee A
LA
Department of Radiology, Cambridge University Teaching Hospitals NHS Foundation Trust, Cambridge, United Kingdom. leegrant100@gmail.com
Napolitano
Antonella
A
Miller
Sam
S
Stephens
Kimberley
K
McHugh
Simon M
SM
Dixon
Adrian K
AK
D000293:Adolescent; D000311:Adrenal Glands / Q000033:anatomy & histology*; D000328:Adult; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010865:Pilot Projects; D011446:Prospective Studies