CHARACTERIZATION OF ADRENAL MASSES USING UNENHANCED CT - AN ANALYSIS OF THE CT LITERATURE

OBJECTIVE. Unenhanced CT scanning can reliably characterize incidental ly detected adrenal masses when observers use density measurements of the adrenal gland. However, controversy exists as to the optimal densi ty threshold required to differentiate benign from malignant lesions. This study attempts to establish a consensus by performing a pooled an alysis of data found in the CT Literature. MATERIALS AND METHODS. Ten CT reports were analyzed, from which individual adrenal lesion density measurements were obtained for 495 adrenal lesions (272 benign lesion s and 223 malignant lesions). Threshold analysis generated a range of sensitivities and specificities for lesion characterization at differe nt density thresholds. RESULTS. Sensitivity for characterizing a lesio n as benign ranged from 47% at a threshold of 2 H to 88% at a threshol d of 20 H. Similarly, specificity varied from 100% at a threshold of 2 H to 84% at a threshold of 20 H. CONCLUSION. The attempt to be absolu tely certain that an adrenal lesion is benign may lead to an unaccepta bly low sensitivity for lesion characterization. The threshold chosen will depend on the patient population and the cost-benefit approach to patient care.