How accurate is MR imaging in characterisation of adrenal masses: update of a long-term study.
OBJECTIVE
The purpose of this study was to update a long-term study that evaluates the accuracy of MR imaging in the characterisation of adrenal tumours. In all patients, MR imaging findings were correlated with histopathologic results.


METHODS
In 204/560 patients who underwent MR imaging for characterisation of an adrenal mass, histopathologic results were available. The final study group consisted of 229 adrenal masses in 204 patients. MR imaging was performed using T2-weighted fast spin-echo imaging and unenhanced and gadolinium-enhanced T1-weighted spin-echo imaging in all patients. In addition, chemical shift imaging was performed in 182 patients and dynamic gadolinium-enhanced studies in 198 patients. Chemical shift images and dynamic studies were qualitatively assessed. All images were reviewed by an experienced investigator (Gertraud Heinz-Peer) who was blinded to the clinical history and the results of prior imaging studies.


RESULTS
The sensitivity of MR imaging for the differentiation of benign and malignant adrenal masses was 89%, the specificity 99%, and the accuracy was 93.9%. This results in a positive predictive value (PPV) of 90.9% and a negative predictive value (NPV) of 94.2%. These results are comparable to the data published previously by our study group with a lower number of cases.


CONCLUSIONS
Large study numbers show that MR imaging is a reliable method in characterisation of benign and malignant adrenal masses. Since laparoscopic adrenalectomy has become the new gold standard in the surgical treatment of benign adrenal lesions, the high accuracy of MR imaging in characterisation of those lesions offers even patients with large adrenal masses (>5 cm) the advantages of the minimally invasive technique.
Hönigschnabl
Selma
S
Division of Surgical Radiology, Department of Radiology, University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
Gallo
Sylvia
S
Niederle
Bruno
B
Prager
Gerhard
G
Kaserer
Klaus
K
Lechner
Gerhard
G
Heinz-Peer
Gertraud
G
D000236:Adenoma / Q000175:diagnosis; D000293:Adolescent; D000307:Adrenal Gland Diseases / Q000175:diagnosis; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000556:secondary; D018268:Adrenocortical Carcinoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000592:standards; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000175:diagnosis; D012680:Sensitivity and Specificity