The aim of the present study was to determine the efficacy of quantitative measurements of the lacrimal gland based on 3-T magnetic resonance (MR) imaging in the diagnosis and staging of Graves' ophthalmopathy (GO). The study retrospectively enrolled 33 patients with GO (the GO group) and 24 healthy volunteers [the healthy control (HC) group] with orbit MR imaging performed using a 3-T MR scanner. Quantitative parameters of the lacrimal gland, including axial length, axial width, axial area, coronal length, coronal width, coronal area, volume and signal intensity ratio (SIR) of the lacrimal gland to the ipsilateral temporal muscle were measured. The difference of quantitative parameters between the GO and HC groups, or between active and inactive GO groups were evaluated using a Student's t-test. Receiver operating characteristic analyses were used to evaluate the diagnostic value of the significant parameters in discriminating patients with GO from healthy controls, or discriminating active from inactive GO. All the quantitative measurements of the GO patients were significantly larger than those of the healthy controls (P<0.05), with the exception of the coronal length (P=0.150). Axial and coronal width had the best efficacy in discriminating patients with GO from healthy controls. Only SIR was found to be different between the active and inactive GO groups (P=0.001). Setting a SIR of 2.57 as the threshold value, the optimal efficacy was achieved (area under the curve, 0.711; sensitivity, 57.7%; specificity, 77.5%) in discriminating between active and inactive GO. Quantitative measurements of the lacrimal gland based on 3-T MR imaging may assist in the diagnosis and stage of GO.

The photoinduced dynamic behavior of flexible materials has received considerable attention for potential applications, such as in data storage or as smart optical devices and molecular mechanical actuators. Until now, precisely controlling expansion and contraction with light has remained a challenge. Unraveling the detailed mechanisms of photoinduced structural transformations remains a critical step necessary to understand the molecular architecture necessary for the design of sensitive photomechanical actuators. Herein, a two‐dimensional flexible metal–organic framework [Zn2(bdc)2(3‐CH3‐spy)2]⋅H2O (Zn2‐1; H2bdc=1,4‐benzenedicaboxylic acid; 3‐CH3‐spy=3‐methylstyrylpyridine) with a positive volumetric thermal expansion coefficient of +78.78×10−6 K−1 is reported. Upon light irradiation at different wavelengths, the MOF underwent a [2+2] cycloaddition, which afforded a family of isomeric, three‐dimensional MOFs (Zn2‐2 n, n=a–d) in a single‐crystal‐to‐single‐crystal (SCSC) manner. An unprecedented phenomenon, that is, photoinduced nonlinear contraction (PINC), was observed during this conversion. The PINC is caused by conformational changes in the 3‐CH3‐spy and bdc2− ligands, the bending of metal–ligand bonds, and the local distortion of the paddle‐wheel SBUs. The formation of a “wrinkle morphology” on the crystal surface after the photoreaction was observed by AFM. This PINC behavior can broaden the studies on materials expansion and offer a photodriven approach for the future design of supersensitive photomechanical actuators.

BackgroundMR imaging has been applied to determine therapeutic response to glucocorticoid (GC) before treatment in thyroid‐associated ophthalmopathy (TAO), while the performance was still poor.PurposeTo investigate the value of T2‐weighted imaging (T2WI)‐derived radiomics for pretreatment determination of therapeutic response to GC in TAO patients, and compare its diagnostic performance with that of semiquantitative parameters.Study TypeRetrospective.PopulationA total of 110 patients (49 ± 12 years; male/female, n = 48/62; responsive/unresponsive, n = 62/48), divided into training (n = 78) and validation (n = 32) cohorts.Field Strength/Sequence3.0 T, T2‐weighted fast spin echo.AssessmentW.C. and H.H. (6 and 10 years of experience, respectively) performed the measurements. Maximum, mean, and minimum signal intensity ratios (SIRs) of extraocular muscle (EOM) bellies were collected to construct a semiquantitative imaging model. Radiomics features from volumes of interest covering EOM bellies were extracted and three machine learning‐based (logistic regression [LR]; decision tree [DT]; support vector machine [SVM]) models were built.Statistical TestsThe diagnostic performances of models were evaluated using receiver operating characteristic curve analyses, and compared using DeLong test. Two‐sided P < 0.05 was considered statistically significant.ResultsThe responsive group showed higher minimum signal intensity ratio (SIRmin) of EOMs than the unresponsive group (training: 1.46 ± 0.34 vs. 1.18 ± 0.39; validation: 1.44 ± 0.33 vs. 1.19 ± 0.20). In both cohorts, LR‐based radiomics model demonstrated good diagnostic performance (area under the curve [AUC] = 0.968, 0.916), followed by DT‐based (AUC = 0.933, 0.857) and SVM‐based models (AUC = 0.919, 0.855). All three radiomics models outperformed semiquantitative imaging model (SIRmin: AUC = 0.805) in training cohort. In validation cohort, only LR‐based radiomics model outperformed that of SIRmin (AUC = 0.745). The nomogram integrating LR‐based radiomics signature and disease duration further elevated the diagnostic performance in validation cohort (AUC: 0.952 vs. 0.916, P = 0.063).Data ConclusionT2WI‐derived radiomics of EOMs, together with disease duration, provides a promising noninvasive approach for determining therapeutic response before GC administration in TAO patients.Level of Evidence3Technical EfficacyStage 4