Development and validation of an image biomarker to identify metabolic dysfunction associated steatohepatitis: MR-MASH score.

BACKGROUND AND AIMS: Diagnosis of metabolic dysfunction-associated steatohepatitis (MASH) requires histology. In this study, a magnetic resonance imaging (MRI) score was developed and validated to identify MASH in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Secondarily, a screening strategy for MASH diagnosis was investigated. METHODS: This prospective multicentre study included 317 patients with biopsy-proven MASLD and contemporaneous MRI. The discovery cohort (Spain, Portugal) included 194 patients. NAFLD activity score (NAS) and fibrosis were assessed with the NASH-CRN histologic system. MASH was defined by the presence of steatosis, lobular inflammation, and ballooning, with NAS ≥4 with or without fibrosis. An MRI-based composite biomarker of Proton Density Fat Fraction and waist circumference (MR-MASH score) was developed. Findings were afterwards validated in an independent cohort (United States, Spain) with different MRI protocols. RESULTS: In the derivation cohort, 51% (n = 99) had MASH. The MR-MASH score identified MASH with an AUC = .88 (95% CI .83-.93) and strongly correlated with NAS (r = .69). The MRI score lower cut-off corresponded to 88% sensitivity with 86% NPV, while the upper cut-off corresponded to 92% specificity with 87% PPV. MR-MASH was validated with an AUC = .86 (95% CI .77-.92), 91% sensitivity (lower cut-off) and 87% specificity (upper cut-off). A two-step screening strategy with sequential MR-MASH examination performed in patients with indeterminate-high FIB-4 or transient elastography showed an 83-84% PPV to identify MASH. The AUC of MR-MASH was significantly higher than that of the FAST score (p < .001). CONCLUSIONS: The MR-MASH score has clinical utility in the identification and management of patients with MASH at risk of progression.

Incidental Adrenal Masses: A Case Report of an Adrenal Oncocytoma.

A 59-year-old woman underwent an abdominal and pelvic computed tomography (CT) scan to rule out non-obstructive urolithiasis. The patient was asymptomatic, with the exception of occasional bilateral low back pain. A physical examination did not reveal any notable findings. The CT scan revealed the presence of an incidental solid left adrenal lesion, which displaced the body of the pancreas and the left kidney. The lesion measured 7 cm × 6.5 cm and exhibited a rounded morphology with well-defined margins. It showed progressive and heterogeneous contrast uptake. Additionally, magnetic resonance imaging (MRI) was performed, confirming the presence of an adrenal lesion with intense and heterogeneous hypersignal on T2. The lesion also demonstrated heterogeneous and persistent enhancement in a dynamic study. Furthermore, there were some indistinct and non-specific hypointense areas identified on both T1 and T2 sequences. The lesion exhibited moderately restricted diffusion. Although the imaging features were non-specific, there were no indications of invasion or distant metastasis, which made a benign large adrenal mass the most likely diagnosis. Non-functioning pheochromocytoma, lipid-poor adrenal adenoma, as well as metastasis or primary adrenal carcinoma, were considered differential diagnoses. The patient underwent an elective adrenalectomy, during which the identified lesion was completely resected. The patient's postoperative recovery was uneventful, and she was discharged three days after the procedure. Subsequent histopathological evaluation revealed an oncocytic neoplasm of the adrenal cortex - specifically, an oncocytoma.