Baseline Volumetric T2 Relaxation Time Histogram Analysis: Can It Be Used to Predict the Response to Intravenous Methylprednisolone Therapy in Patients With Thyroid-Associated Ophthalmopathy?

Abstract

ObjectivePrediction of therapy response to intravenous methylprednisolone pulses (ivMP) is crucial for thyroid-associated ophthalmopathy (TAO). Image histograms may offer sensitive imaging biomarkers for therapy effect prediction. This study aimed to investigate whether pretherapeutic, multiparametric T2 relaxation time(T2RT) histogram features of extraocular muscles (EOMs) can be used to predict therapy response.Materials and MethodsForty-five active and moderate-severe TAO patients, who were treated with standard ivMP and underwent orbital MRI before therapy, were retrospectively included in this study. The patients were divided into responsive (n = 24, 48 eyes) and unresponsive group(n = 21, 42 eyes) according to clinical evaluation. Baseline clinical features of patients and histogram-derived T2RT parameters of the EOMs were analyzed and compared. Logistic regression model was conducted to determine independent predictors, and a histogram features nomogram was formulated for personalized prediction.ResultsResponsive group displayed lower values for 5th, 10th percentiles (P < 0.050, respectively), and higher values for 75th, 90th, and 95th percentiles, skewness, entropy, and inhomogeneity (P < 0.050, respectively) than unresponsive group. Multivariate logistic regression analysis showed that 95th percentile of >88.1 [odds ratio (OR) = 12.078; 95% confidence interval (CI) = 3.98–36.655, p < 0.001], skewness of >0.31 (OR = 3.935; 95% CI = 2.28–6.788, p < 0.001) and entropy of >3.41 (OR = 4.375; 95% CI = 2.604–7.351, p < 0.001) were independent predictors for favorable response. The nomogram integration of three independent predictors demonstrated optimal predictive efficiency, with a C-index of 0.792.ConclusionsPre-treatment volumetric T2RT histogram features of EOMs could function to predict the response to ivMP in patients with TAO. The nomogram based on histogram features facilitates the selection of patients who will derive maximal benefit from ivMP.

T2‐Weighted MR Imaging‐Derived Radiomics for Pretreatment Determination of Therapeutic Response to Glucocorticoid in Patients With Thyroid‐Associated Ophthalmopathy: Comparison With Semiquantitative Evaluation

“…Components of inflammatory edema show a good response to systemic GC administration, while those of the fibrotic compounds do not 30 . According to previous suggestions, responsive TAOs commonly demonstrate more homogeneous edema within EOMs; therefore, they manifest a satisfactory therapeutic response to GC 13,14,32 . However, unresponsive TAOs usually have greater tissue complexity and more fibrous scarring within edema; hence, they may have a lower therapeutic response 13,14,32 .…”

“…In recent years, due to the dissonance between growing clinical needs and uncertain utility of clinical markers, 6–11 a few researchers have begun to utilize MRI to determine the therapeutic response before GC treatment in patients with TAO 12–14 . T 2 ‐based imaging derived SI or relaxation time of EOMs, incorporated with histogram analysis, has been reported to be effective in the classification 13,14 . Meanwhile, it has opened up a new era of studying the heterogeneity of EOMs in patients with TAO 13,14 .…”

“…In accordance with the detected results from the semiquantitative imaging model, original_firstorder_Minimum showed a positive relationship with the therapeutic response. Considering the prior knowledge that the responsive group may have more homogeneous edematous environment of EOMs resulting in smaller span of SI and less heterogeneity, 14,32 the inverse relationship between original_firstorder_Range, as well as squareroot_glszm_GrayLevelNonUniformity and wavelet.LLL_firstorder_Skewness, 33 and therapeutic response would also be reasonable. Through uniting both low‐level and high‐dimensional features derived from T 2 WI, it is verified that the utilization of radiomics could also facilitate the decision support regarding the pretreatment determination of therapeutic response in patients with TAO.…”

“…However, the diagnostic abilities of these markers can be controversial among studies 10,11 . With the increasing application of orbital MRI, a few attempts have been made on structural and functional MRI for solving this clinical issue 12–14 . Morphological measurements, such as the thickness and the volume of orbital tissues, have been found to correlate with the response to GC, but the diagnostic performance was poor, with area under the curves (AUCs) of 0.590–0.702 12,13 .…”

“…Morphological measurements, such as the thickness and the volume of orbital tissues, have been found to correlate with the response to GC, but the diagnostic performance was poor, with area under the curves (AUCs) of 0.590–0.702 12,13 . Recently, T 2 ‐based imaging with the derived signal intensity (SI) or relaxation time at extraocular muscles (EOMs), accompanied with histogram analysis, has been reported as potential imaging markers for the pretreatment determination 13,14 . This emphasis placed on the SI and inhomogeneity within orbital tissues has brought significant insights to assist in determining therapeutic response, thereby contributing to the improvement of classification accuracy 13,14 .…”