Adrenal lesions with heterogeneous suppression on chemical shift imaging: clinical implications.
OBJECTIVE
To investigate the frequency and significance of adrenal lesions that demonstrate heterogeneous suppression on chemical shift magnetic resonance imaging (MRI).


METHODS
A retrospective search of adrenal lesions identified on MR from November 1997-July 2001 was performed. The adrenal lesions were classified as having suppression typical for an adenoma, nonsuppression, or atypical heterogeneous suppression. Lesions with heterogeneous suppression were further reviewed. Follow-up for the heterogeneous lesions consisted of imaging studies or pathology from surgical excision.


RESULTS
Adrenal lesions were identified in 242 patients. Heterogeneously suppressing lesions were seen in 34 (14%) patients. Several different patterns of heterogeneous suppression were identified. Imaging or pathologic follow-up was available for 18 of the heterogeneously suppressing lesions (one patient had both). Fifteen patients with follow-up imaging showed stability of the lesion over a significant interval, suggesting a benign lesion. Pathology was available for four patients revealing two patients with adenomas and two patients with nodular hyperplasia. Thus, all 18 patients with heterogeneous suppression had a benign lesion.


CONCLUSIONS
Adrenal lesions that have a heterogeneous pattern of suppression on out-of-phase chemical shift MR images are a common finding. Our small series suggest that these lesions are probably benign.
Department of Radiology, Northwestern University Medical School, Chicago, Illinois 60611, USA. hgabriel@nmff.org
Helena
H
Gabriel
Victor
V
Pizzitola
Erin N
EN
McComb
Elizabeth
E
Wiley
Frank H
FH
Miller
D000236:Adenoma / Q000175:diagnosis*; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000473:pathology; D000311:Adrenal Glands / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies