Performance of apparent diffusion coefficient of medial and lateral rectus muscles in Graves' orbitopathy

Abstract

Objective The purpose of this study was to determine the performance of the apparent diffusion coefficient in the detection of involvement of the medial and lateral rectus muscles in patients with Graves' orbitopathy. Methods and materials This prospective study was conducted on 33 consecutive patients (16 males, 17 females with a mean age of 36 years) with Graves' orbitopathy and 18 age- and sex-matched volunteers. The patients and volunteers underwent diffusion-weighted magnetic resonance imaging of the orbit in the axial plane using echo-planar imaging. The apparent diffusion coefficient of the medial and lateral rectus muscles was calculated. Results The medial rectus muscle was more affected than the lateral rectus muscle. The mean apparent diffusion coefficient value of the medial and lateral rectus muscles was 1.81 ± 0.19 and 1.72 ± 0.07 × 10mm/s in patients with Graves' orbitopathy and 1.59 ± 0.06 and 1.51 ± 0.06 × 10 mm/s in volunteers, respectively. There was a significant difference in apparent diffusion coefficient values of the medial and lateral rectus muscles between patients with Graves' orbitopathy and volunteers ( p = 0.001). The classification performance as measured with area under the receiver operator characteristic curve was 0.89 (95% confidence interval: 0.732-0.904). The best performing threshold of the apparent diffusion coefficient value of the medial rectus muscle was 1.69 × 10 mm/s and associated efficiency was 86%, sensitivity was 97%, and specificity was 97%. Conclusion We concluded that the apparent diffusion coefficient of the medial rectus muscle can be used for diagnosis of Graves' orbitopathy.

Utility of T2 mapping in the staging of thyroid-associated ophthalmopathy: efficiency of region of interest selection methods

“…Moreover, it was a semi-quantitative measurement with the potential risk of reduced sensitivity and increased variability. Recently, some studies utilized diffusion-weighted imaging (DWI) for the evaluation of TAO (4,6,27–29). They found that the apparent diffusion coefficient of EOMs or lacrimal glands could also be useful to evaluate disease activity (4,27,28).…”

Non-EPI-DWI for Detection, Disease Monitoring, and Clinical Decision-Making in Thyroid Eye Disease

“…In addition, ADC values were derived for the medial and inferior recti bilaterally on all scans, irrespective of the initial survey, because TED appears to have a predilection for these EOMs. 14 The oblique muscles were excluded from analysis due to concerns about the reliability of measurement in an oblique plane as well as being atypical sites for TED involvement. Right and left values in each individual were analyzed separately to reflect that disease can be unilateral and asymmetric.…”

“…[10][11][12][13] Results from these reports have been variable, and some techniques have additional limitations that include the adverse events associated with contrast administration and necessary standardization corrections to allow reliable comparison between scans (eg, normalization of signal intensities with those of the nearby temporalis muscle). 14,15 DWI is an MR imaging technique that measures movement of water molecules within tissues to calculate an ADC, in which higher ADC values indicate greater facilitated diffusion reflective of an underlying active inflammatory process. 14 Echo-planar DWI has shown promise in the evaluation of active TED, and studies have demonstrated higher ADC values in the EOMs of patients with TED compared with healthy controls.…”

“…14,15 DWI is an MR imaging technique that measures movement of water molecules within tissues to calculate an ADC, in which higher ADC values indicate greater facilitated diffusion reflective of an underlying active inflammatory process. 14 Echo-planar DWI has shown promise in the evaluation of active TED, and studies have demonstrated higher ADC values in the EOMs of patients with TED compared with healthy controls. 14,16,17 In studies comparing active with inactive TED, the ADC is reported to be higher in active disease and is elevated at an early stage in the disease before activity is detected on routine MR imaging, suggesting the potential utility of ADC evaluation at an early time point in the disease trajectory.…”

“…14 Echo-planar DWI has shown promise in the evaluation of active TED, and studies have demonstrated higher ADC values in the EOMs of patients with TED compared with healthy controls. 14,16,17 In studies comparing active with inactive TED, the ADC is reported to be higher in active disease and is elevated at an early stage in the disease before activity is detected on routine MR imaging, suggesting the potential utility of ADC evaluation at an early time point in the disease trajectory. 16,17 Non-EPI-DWI, however, has the potential of higher resolution images and a reduction in air-bone interface artifact distortion.…”