Extraocular muscle volume index at the orbital apex with optic neuritis: a combined parameter for diagnosis of dysthyroid optic neuropathy.

OBJECTIVES: To evaluate the diagnostic performance of the extraocular muscle volume index at the orbital apex (AMI) and the signal intensity ratio (SIR) of the optic nerve in dysthyroid optic neuropathy (DON). METHODS: Clinical data and magnetic resonance imaging were collected retrospectively from 63 Graves' ophthalmopathy patients, including 24 patients with DON and 39 without DON. The volume of these structures was obtained by reconstructing their orbital fat and extraocular muscles. The SIR of the optic nerve and axial length of eyeball were also measured. The posterior 3/5 of the retrobulbar space volume was used as the orbital apex to compare parameters in patients with or without DON. Area under the receiver operating characteristic curve (AUC) analysis was used to select the morphological and inflammatory parameters with the highest diagnostic value. A logistic regression was performed to identify the risk factors of DON. RESULTS: One hundred twenty-six orbits (35 with DON and 91 without DON) were analyzed. Most of the parameters in DON patients were significantly higher than in non-DON patients. However, the SIR 3 mm behind the eyeball of the optic nerve and AMI had the highest diagnostic value in these parameters and are independent risk factors of DON by stepwise multivariate logistic regression analysis. Combining AMI and SIR had a higher diagnostic value than a single index. CONCLUSIONS: Combining AMI with SIR 3 mm behind the eyeball's orbital nerve can be a potential parameter for diagnosing DON. CLINICAL RELEVANCE STATEMENT: The present study provided a quantitative index based on morphological and signal changes to assess the DON, allowing clinicians and radiologists to monitor DON patients timely. KEY POINTS: The extraocular muscle volume index at the orbital apex (AMI) has excellent diagnostic performance for dysthyroid optic neuropathy. A signal intensity ratio (SIR) of 3 mm behind the eyeball has a higher AUC compared to other slices. Combining AMI and SIR has a higher diagnostic value than a single index.

Central Sensitivity to Free Triiodothyronine With MAFLD and Its Progression to Liver Fibrosis in Euthyroid Adults.

CONTEXT: Impaired sensitivity to thyroid hormones has been demonstrated to be positively associated with the prevalence of metabolic disorders. However, the relationship between sensitivity to thyroid hormones and metabolic dysfunction-associated fatty liver disease (MAFLD) and liver fibrosis remained unclear. OBJECTIVE: We aimed to determine the associations of thyroid hormone sensitivity indices with MAFLD and its progression to liver fibrosis in Chinese euthyroid adults. METHODS: This community-based study included 7906 euthyroid adults. We calculated the thyroid sensitivity indices, including free triiodothyronine to free thyroxine (FT3/FT4) ratio, Thyroid Feedback Quantile-based Index by FT4 (TFQIFT4), and Thyroid Feedback Quantile-based Index by FT3 (TFQIFT3), indicating peripheral and central thyroid hormone sensitivity respectively. Liver steatosis and fibrosis were diagnosed by vibration-controlled transient elastography (VCTE). Multivariable logistic/linear regression and restricted cubic spline (RCS) analysis were conducted. RESULTS: Compared with participants in the first quartile (Q1), the prevalence of MAFLD was increased by 62% in the fourth quartile (Q4) of FT3/FT4 ratio (OR 1.62; 95% CI [1.38, 1.91]) and by 40% in Q4 of TFQIFT3 (OR 1.40; 95% CI [1.18, 1.65]) (both P < .05). No associations between TFQIFT4 and the prevalence of MAFLD were found. In addition, compared with participants in Q1, the prevalence of liver fibrosis was increased by 45% in Q4 of TFQIFT3 (OR 1.45; 95% CI [1.03, 2.06]) (P < .05) in participants with MAFLD. CONCLUSION: Impaired central sensitivity to FT3 was associated with MAFLD and its progression to liver fibrosis. More prospective and mechanism studies are warranted to confirm these conclusions.