The Value Of 3T - MRI Orbital Structure Quantitative Measurement In The Diagnosis And Staging Of Graves' Ophthalmopathy

Objective To evaluate the diagnostic and staging value of quantitative measurements of orbital structures in patients with Graves’ ophthalmopathy(GO) based on 3T MR imaging. Materials and methods Twenty-three GO patients(patient group) and eighteen healthy volunteers(healthy control group) were enrolled. Quantitative measurements of orbital structures including exophthalmos values, fatty tissue thickness of the inner side of eye balls, cross-sectional areas of extraocular muscles and signal intensity ratios of extraocular muscles to the ipsilateral temporal muscles(SIR values) were compared between two groups. Correlations between the quantitative values and clinical active score(CAS) were accessed. Receiver operating characteristic(ROC) analysis was performed to evaluate the diagnostic value of the most correlated quantitative value to discriminate active from the inactive GO patients. Results There were significant differences between the GO group and control group regarding to all the quantitative measurements(P<0.05). Strong correlation was found between SIR values and CAS(r=0.730, P<0.001). Significant difference of SIR was found between patients with active GO and those with inactive GO(P=0.002), and a cut off value of 3.25 might be the critical threshold value, with the diagnostic sensitivity of 81.8% and specificity of 83.3%, respectively. Conclusion Quantitative measurements of orbital structures based on 3T MR imaging could assist in diagnosing and staging GO.Objective To evaluate the clinical value of quantitative measurements of lacrimal gland in the diagnosis and stage of GO based on 3T-MR imaging. Materials and methods Thirty-three GO patients(patient group) and twenty-four healthy volunteers(healthy control group) were enrolled in our study and 3.0T MR orbit scans were performed. Quantitative parameters of lacrimal gland, including axial length, axial width, axial area, coronal length, coronal width, coronal area, volume and signal intensity ratio of lacrimal gland to the ipsilateral temporal muscle were measured. The difference of parameters between GO patients and healthy controls, or between the active and inactive GOs were compared with t test. ROC analyses were used to evaluate the diagnostic value of the significant parameters in discrimination of GO patients from healthy controls, or discrimination of active from inactive GOs. Results All the quantitative measurements were significantly larger in the GO group than in the control group(P<0.05), except the coronal length. Axial and coronal width had the better clinical value in the discrimination of GO patients from healthy controls. Only SIR was found to be different between active and inactive GOs(P=0.001). Setting the SIR of 2.57 as the threshold value, the optimal staging value could be achieved(AUC, 0.711; sensitivity, 57.7%; specificity, 77.5%). Conclusion Quantitative measurements of lacrimal gland based on 3T MR imaging could assist in diagnosing and staging GO.