Is it Possible to Assess the Functional Status of Hormone Secretion or Non- Secretion of Adrenal Masses Through Their Magnetic Resonance Imaging (MRI) Characteristics?

Abstract

Background: Diagnostic imaging techniques including magnetic resonance imaging (MRI) should also perform on all patients with incidentalomas. However, there is a limited study whether the quantitative measurements (signal intensity index, adrenal to spleen ratio) in MRI could predict the functional status of adrenal adenomas. Material-Method: Between 2015-2020; 404 patients (265 females, 139 males) with adrenal mass who were referred to the university hospital for further investigation were included. After detailed diagnostic hormonal evaluation, all patients underwent MRI 1.5 T device (Signa, GE Medical Systems; Milwaukee, USA). The signal intensities of the adrenal lesions on T2W images were qualitatively evaluated and noted as homogenous or heterogeneous in comparison with the liver signal intensity (SI). A chemical-shift SI index and chemical shift adrenal-to-spleen SI ratio were also calculated. Results: While 331(81.9%) of the patients had nonfunctional adrenal mass, the rest of them (n=73, 18.1%) were patients with functional (autonomous cortisol secretion-ACS, cushing syndrome-CS, pheochromocytoma, primary hyperaldosteronism-PA) adrenal masses. In phase vs phase values of patients with NFAI, Pheo(n=17), ACS (n=30), CS (n=11), and PA (n=15) were 474.04±126.7 vs 226.6±132.4, 495.3±182.8 vs 282.17±189.1, 445.2±134.8 vs 203.3±76.2, 506.8±126.5 vs 212.2±73.6 and 496.2±147.5 vs 246.6±102.1, respectively. Mean signal intensity index (SII) and adrenal to spleen ratio (ASR) of all groups (NFAI, Pheo, ACS, CS, PA) were 52.0±24.8 and 0.51, 44.9±22.5 and 0.55, 49.5±24.5 and 0.53, 56.2±16.4 and 0.43, 47.6±25.1 and 0.54, respectively. Based the current accepted measurements in the case of ASR and SII, all lesions were similar and shown as fat rich adenomas (p*= 0.552, p** = 0.45). Conclusion: The quantitative assessment (SII, ASR) of intracellular lipids in an incidentally discovered adrenal tumour could only help distinguish adrenal masses in case of adenomas or non-adenomas As initial diagnostic evaluation, clinical and laboratory assessment ,to distinguish hormone secretion, should be taken in all patients with adrenal incidentalomas.

Beyond symptomatology: A comparative analysis of unilateral and bilateral macronodular mild autonomous cortisol secretion

“…Previously, it was reported that the diagnosis of adrenal adenoma might be predicated on the ability to document microscopic fat in lipid‐rich adenomas by using quantitative SII instead of subjective analysis 35 . In a study conducted by Akkus et al, the mean SII of 30 cases with ACS was found to be 49.5 ± 24.5 17 . A limited number of MRI studies have been conducted in MACS patients, and to the best of our knowledge, there is no study that has independently assessed the SII of adenomas in patients with bilateral and unilateral macronodular MACS.…”

“…This involves detecting a chemical shift in lipid‐rich lesions, which is indicated by a signal decrease on T1‐weighted out‐of‐phase images relative to T1‐weighted in‐phase images. Assessment can be conducted through qualitative visual analysis or a quantitative approach, where a signal drop exceeding 16.5% is substantial 16,17 …”

“…Assessment can be conducted through qualitative visual analysis or a quantitative approach, where a signal drop exceeding 16.5% is substantial. 16,17 Despite a growing interest, there are certain aspects that remain unknown regarding the distinguishing characteristics between unilateral and bilateral macronodular MACS in patients with AI. In the present study, we aimed to investigate the clinical, laboratory findings and signal intensity index (SII) on MRI of patients with bilateral and unilateral MACS.…”