Adrenal nonhyperfunctioning adenoma and nonadenoma: CT attenuation value as discriminative index

Abstract

Our data suggest that an asymptomatic adrenal mass with homogeneous low attenuation (< or = 15 HU) and less than or equal to 4 cm indicates a nonhyperfunctioning adenoma, and no further examinations are necessary. CT attenuation value on non-contrast CT is the most important discriminatory factor.

Adrenal masses: the value of additional fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in differentiating between benign and malignant lesions

“…Accurate staging, including the existence of adrenal malignant lesions, is important in determining a strategy for therapy and patient management. According to previous reports [3][4][5][6], lipid-rich adenoma may be differentiated from SUV max maximum standardized uptake value, CTAV CT attenuation value, T/L SUV max ratio, tumor/liver SUV max ratio, SEN sensitivity, SPE specificity, ACC accuracy, PPV positive predictive value, NPV negative predictive value metastasis using a cut-off value of 10 HU; however, in the present study, 2 adrenal benign lesions had values greater than 10 HU. In addition, CT attenuation values greater than 10 HU are seen in approximately 29% of adenomas (lipid-poor adenomas) [5]; therefore, these lesions remain indeterminate on unenhanced CT.…”

“…The conventional criterion for CT diagnosis of adrenal adenoma is based on the CT attenuation value (Hounsfield Units, HU), with a suggested threshold value of 0-20 HU for unenhanced CT [3][4][5][6]. A cut-off value of 10 HU is widely accepted [5,7,8] because lipid-rich adenoma is diagnosed in lesions with a CT attenuation value of \10 HU on unenhanced CT.…”

Differentiation of Adrenal Adenoma and Nonadenoma in Unenhanced CT: New Optimal Threshold Value and the Usefulness of Size Criteria for Differentiation

“…In a literature review, Hamrahian et al (36) performed their study, based on 157 adrenal adenomas/hyperplasia and 142 nonadenomas, including 35 adrenal metastases. Miyake et al analyzed 14 nonfunctioning adrenal adenomas and 22 nonadenomas, including 16 metastases (19). Korobkin et al examined 93 cortical adrenal adenomas and 42 malignant adrenal lesions, including 34 metastases (12).…”

“…The utility of unenhanced CT is based on intracytoplasmic fat, which is often more abundant in adrenal adenomas but rare in adrenal metastases, pheochromocytomas, or adrenocortical carcinomas (18). The threshold values for noncontrast CT in HU units, ranging from 0 HU to 20 HU, have been suggested in the literature, and a value of 10 HU was recommended by a consensus panel organized by the National Institutes of Health (1, 19-24). In practice, we frequently encountered adrenal adenomas with attenuation values > 10 HU.…”

Precision of the measurement of CT numbers: comparison of dual-energy CT spectral imaging with fast kVp switching and conventional CT with phantoms

“…There was no statistically significant difference in slope among the three regression lines affect the CT number of the lesion of interest, to achieve accurate CT number acquisition. Furthermore, simulated monochromatic images created with dual-energy CT may enable more accurate diagnoses dependent on CT number measurement such as distinction between adrenal adenoma and other tumors [21][22][23][24] because the accuracy of CT number measurement without the influence of body shape means robustness against individual differences. A potential disadvantage of dual-energy spectral CT is increased radiation exposure.…”