Assessment of lacrimal glands in thyroid eye disease with diffusion-weighted magnetic resonance imaging

Computed tomography and magnetic resonance imaging approaches to Graves' ophthalmopathy: a narrative review

Graves' ophthalmopathy (GO) affects up to 50% of patients with Graves' disease (GD) ranging from mild ocular irritation to vision loss. The initial diagnosis is based on clinical findings and laboratory tests. Orbital imaging, such as magnetic resonance imaging (MRI) and computed tomography (CT), is an important tool to assess orbital changes, being also useful for understanding disease progression and surgical planning. In this narrative review, we included 92 studies published from 1979 to 2020 that used either MRI and/or CT to diagnose and investigate GO, proposing new methods and techniques. Most of the methods used still need to be corroborated and validated, and, despite the different methods and approaches for thyroid eye disease (TED) evaluation, there is still a lack of standardization of measurements and outcome reports; therefore, additional studies should be performed to include these methods in clinical practice, facilitating the diagnosis and approach for the treatment of TED.

Magnetic Resonance Imaging in the Management of Thyroid Eye Disease: A Systematic Review

PURPOSE

MRI may potentially detect active thyroid eye disease prior to elevation of clinical activity score. We aimed to systematically review the existing literature pertaining to MRI thyroid eye disease and to assess the role of MRI in the diagnosis of thyroid eye disease.

METHODS

A Population, Intervention, Comparison, Outcome/Preferred Reporting Items for Systematic Reviews and Meta-Analyses selection criteria was applied to identify studies for inclusion published between the years 2000 and 2023.

RESULTS

Twenty-four articles were identified for inclusion in the systematic review. All included studies utilized MRI as the imaging modality. MRI sequences used included T2-weighted imaging in 87.5%, T1-weighted imaging in 54.2%, diffusion-weighted imaging in 20.8%, and short tau inversion recovery in 16.7%. The most common parameters quantified were signal intensity ratio in 10 studies (41.7%) and T2-relaxation time in 8 studies (33.3%). Signal intensity ratio and T2-relaxation time were shown to correlate with clinical activity score and identify the phase of the disease.

CONCLUSIONS

MRI has untapped potential for further elucidating the highly complex biological processes in thyroid eye disease. As we move away from clinical activity score as a predictor of response to biologic therapy, MRI may prove more important than ever in the risk-benefit analysis around the use of immunomodulators.

Case Report of Graves' Disease in a 45-Year-Old Woman Secondary to Herceptin Treatment for Breast Cancer

Graves' disease is the most common cause of thyrotoxicosis and is characterized by ophthalmopathy with proptosis, chemosis, or conjunctival injection; pretibial myxedema; and thyroid acropachy. It is an autoimmune disease that can be genetic or influenced by coexisting environmental factors such as exposure to anticancer drugs, including immune checkpoint inhibitors. The incidence rate of breast cancer is increasing due to rising awareness of risk factors and screening for breast cancer, and the mortality rate is decreasing due to recent advances in cancer treatment. However, there are side effects that are attributed to these treatment modalities, manifesting in various forms in breast cancer survivors, which are reflected in the patient in this case study.

Application of Quantitative MRI in Thyroid Eye Disease: Imaging Techniques and Clinical Practices

Thyroid eye disease (TED) is a complex autoimmune disorder that impairs various orbital structures, leading to cosmetic damage and vision loss. Magnetic resonance imaging (MRI) is a fundamental diagnostic tool utilized in clinical settings of TED, for its accurate demonstration of orbital lesions and indication of disease conditions. The application of quantitative MRI has brought a new prospect to the management and research of TED, offering more detailed information on morphological and functional changes in the orbit. Therefore, many researchers concentrated on the implementation of different quantitative MRI techniques on TED for the exploration of clinical practices. Despite the abundance of studies utilizing quantitative MRI in TED, there remain considerable barriers and disputes on the best exploitation of this tool. This could possibly be attributed to the complexity of TED and the fast development of MRI techniques. It is necessary that clinical and radiological aspects of quantitative MRI in TED be better integrated into comprehensive insights. Hence, this review traces back 30 years of publications regarding quantitative MRI utilized in TED and elucidates this promising application in the facets of imaging techniques and clinical practices. We believe that a deeper understanding of the application of quantitative MRI in TED will enhance the efficacy of the multidisciplinary management of TED. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.

Diffusion-Weighted Imaging of the Orbit: A Case Series and Systematic Review

PURPOSE

To describe the findings of diffusion-weighted imaging (DWI) for a series of orbital lesions and provide a systematic review of relevant literature.

METHODS

A retrospective review of 20 patients with orbital lesions who underwent MRI with DWI at two academic institutions between 2015 and 2020 was performed. Lesion diagnosis was histopathologically confirmed except a presumed cavernous hemangioma. Echoplanar diffusion-weighted images had been acquired using 2 or 3 b values (b=0 and 1000 or b=0, 500, and 1000) at 1.5T or 3T. Lesions with significant artifacts were excluded. DWI sequences were analyzed by neuro-radiologists blinded to the diagnosis. Mean ADC values of lesions were calculated from a single region of interest. An independent two-tailed t test was used to compare categories of lesions with p < 0.05 considered significant. A systematic review of the literature was performed.

RESULTS

Our study included 21 lesions. ADC values were significantly lower for malignant lesions (0.628 ± 0.125 × 10 -3 mm 2 /s) than inflammatory lesions (1.167 ± 0.381 × 10 -3 mm 2 /s) ( p < 0.001). ADC values were significantly lower for orbital lymphoma (mean 0.621 ± 0.147 × 10 -3 mm 2 /s) than idiopathic orbital inflammation (mean 1.188 ± 0.269 × 10 -3 mm 2 /s) with no overlap ( p < 0.001).

CONCLUSIONS

Orbital malignancies demonstrated lower ADC values, while inflammatory processes demonstrated higher ADC values, except IgG4-related disease. DWI and ADC values differentiated idiopathic orbital inflammation from orbital lymphoma. This study highlights the role of DWI in evaluating orbital pathology.

Histopathological features of asymmetric lacrimal gland enlargement in patients with thyroid eye disease

PURPOSE

Lacrimal gland enlargement can be a feature of thyroid eye disease (TED). Unilateral or asymmetric lacrimal gland enlargement is poorly described and may impede diagnosis. We present the histological and clinical findings of four patients with asymmetric lacrimal gland enlargement.

METHODS

A retrospective case note review was performed for patients over two tertiary orbital clinics (Royal Adelaide Hospital, South Australia and the Sussex Eye Hospital, Brighton, United Kingdom) presenting with an asymmetrical lacrimal gland enlargement with a background of TED that underwent biopsy to exclude alternate diagnoses. Baseline data was collected for each patient and histopathological images and reports were reviewed.

RESULTS

All four patients were hyperthyroid at time of lacrimal gland biopsy. Biopsy demonstrated nonspecific, lymphoid aggregates, typically of B cell type, with no diagnostic findings to support lymphocyte clonality or IgG4-related disease. One biopsy specimen demonstrated evidence of some fibrosis.

CONCLUSION

Asymmetrical lacrimal gland enlargement can occur as part of the TED spectrum but may require biopsy to exclude alternate pathology. Histology demonstrates a non-specific lymphocytic infiltrate.

Magnetic resonance imaging parameters on lacrimal gland in thyroid eye disease: a systematic review and meta-analysis

BACKGROUND

Thyroid eye disease is an extrathyroidal manifestation of Graves' disease and is associated with dry eye disease. This is the first systematic review and meta-analysis to evaluate the role of magnetic resonance imaging lacrimal gland parameters in thyroid eye disease diagnosis, activity grading, and therapeutic responses prediction.

METHODS

Up to 23 August, 2022, 504 studies from PubMed and Cochrane Library were analyzed. After removing duplicates and imposing selection criteria, nine eligible studies were included. Risk of bias assessment was done. Meta-analyses were performed using random-effect model if heterogeneity was significant. Otherwise, fixed-effect model was used. Main outcome measures include seven structural magnetic resonance imaging parameters (lacrimal gland herniation, maximum axial area, maximum coronal area, maximum axial length, maximum coronal length, maximum axial width, maximum coronal width), and three functional magnetic resonance imaging parameters (diffusion tensor imaging-fractional anisotropy, diffusion tensor imaging-apparent diffusion coefficient or mean diffusivity, diffusion-weighted imaging-apparent diffusion coefficient).

RESULTS

Thyroid eye disease showed larger maximum axial area, maximum coronal area, maximum axial length, maximum axial width, maximum coronal width, diffusion tensor imaging-apparent diffusion coefficient/ mean diffusivity, and lower diffusion tensor imaging-fractional anisotropy than controls. Active thyroid eye disease showed larger lacrimal gland herniation, maximum coronal area, diffusion-weighted imaging-apparent diffusion coefficient than inactive. Lacrimal gland dimensional (maximum axial area, maximum coronal area, maximum axial length, maximum axial width, maximum coronal width) and functional parameters (diffusion tensor imaging-apparent diffusion coefficient, diffusion tensor imaging-apparent diffusion coefficient) could be used for diagnosing thyroid eye disease; lacrimal gland herniation, maximum coronal area, and diffusion-weighted imaging-apparent diffusion coefficient for differentiating active from inactive thyroid eye disease; diffusion tensor imaging parameters (diffusion tensor imaging-fractional anisotropy, diffusion tensor imaging-mean diffusivity) and lacrimal gland herniation for helping grading and therapeutic responses prediction respectively.

CONCLUSIONS

Magnetic resonance imaging lacrimal gland parameters can detect active thyroid eye disease and differentiate thyroid eye disease from controls. Maximum coronal area is the most effective indicator for thyroid eye disease diagnosis and activity grading. There are inconclusive results showing whether structural or functional lacrimal gland parameters have diagnostic superiority. Future studies are warranted to determine the use of magnetic resonance imaging lacrimal gland parameters in thyroid eye disease.

Ocular Surface Changes in Treatment-Naive Thyroid Eye Disease

OBJECTIVE

To investigate the association of meibomian gland dysfunction (MGD) and ocular surface exposure with tear film instability in untreated thyroid eye disease (TED) patients.

METHODS

A cross-sectional study of TED patients from September 2020 to September 2022 was conducted. Ocular surface parameters included ocular surface disease index (OSDI), tear meniscus height (TMH), non-invasive tear break-up time (NITBUT), partial blinking rate, lipid layer thickness (LLT), meibomian gland dropout (meiboscore), Schirmer's test, and corneal punctate epithelial erosions (PEE). Ocular surface exposure was assessed by the margin reflex distances of the upper and lower eyelid (MRD1 and MRD2), the amount of exophthalmos, lateral flare, and lagophthalmos.

RESULTS

In total, 152 eyes from 76 TED patients (64 females and 12 males, age 42.99 ± 12.28 years) and 93 eyes from 61 healthy controls (51 females and 10 males, age 43.52 ± 17.93 years) were examined. Compared with control eyes, TED eyes had higher OSDI, TMH, LLT, and PEE; shorter NITBUT; and worse meiboscore (all p < 0.05). They also had larger amounts of exophthalmos, longer MRD1, more lateral flare, and lagophthalmos. Multivariate analysis identified an association of the tear film instability with lagophthalmos (β = -1.13, 95%CI: -2.08, -0.18) and severe MGD in the lower eyelid (β = -5.01, 95%CI = -7.59, -2.43).

CONCLUSIONS

Dry eye in TED is mainly manifested as evaporative dry eye disease. Severe lower eyelid MGD and worse lagophthalmos were significantly associated with tear film instability in treatment-naive TED patients.

Change in lacrimal gland volume and aqueous tear production following treatment with teprotumumab

BACKGROUND

Dry eye syndrome occurs in up to 85% of patients with thyroid eye disease (TED). Lacrimal gland enlargement correlates with subjective tearing and a reduction in quality of life in patients with TED.

METHODS

In this prospective longitudinal study, patients presenting for the treatment of TED were considered for eligible. Primary outcomes included a change in the volume of the lacrimal gland and the production of tears following treatment with teprotumumab. The volume of lacrimal glands and proptosis was calculated using 3D volumetric analysis. Tear production was measured by Schirmer's test and associated symptoms were assessed using the VLSQ-8. The orbit with the most proptosis was designated the study orbit and the contralateral orbit was designated the fellow orbit.

RESULTS

Twenty patients were included. Mean (SD) age was 61 (18) and mean duration of TED prior to therapy was 48 months (47). Lacrimal gland volume in the study orbit decreased from 768 mm³ (288) to 486 mm³ (173) (p < 0.01) following therapy. For the fellow orbit, volume reduced from 637 mm³ (261) to 379 mm³ (147) (p < 0.01). Schirmer's test reading (STR) in the study orbit increased from 14.5 mm (8.2) to 23 mm (10) (p < 0.01) (59%) following treatment. In the fellow orbit, STR increased from 12.7 mm (7) to 21 mm (9) post therapy (69%) (p < 0.01). There was a significant improvement on all parts of the VLSQ-8.

CONCLUSION

Teprotumumab significantly reduces TED related expansion of the lacrimal gland, increases tear production, and improves dry eye symptoms.

Quantitative assessment of the intraorbital segment of the optic nerve in patients with thyroid orbitopathy using diffusion tensor imaging

BACKGROUND

It is difficult to detect optic nerve changes in patients with thyroid-associated ophthalmopathy (TAO) before the development of optic neuropathy.

PURPOSE

To detect changes in the intraorbital segment of the optic nerve in patients with TAO using diffusion tensor imaging (DTI) and determine any correlations with disease severity.

MATERIAL AND METHODS

A total of 74 participants (17 normal, 22 mild, and 35 moderate-severe TAO) were organized to be given 3-T DTI to measure fractional anisotropy (FA) and mean diffusivity (MD) for the orbital segments of their optic nerves. All underwent ophthalmological examinations for visual acuity, intraocular pressure, exophthalmos, and fundoscopy, and were assessed based on the Clinical Activity Score (CAS). Univariate analysis of variance and Pearson's correlation coefficients were carried out.

RESULTS

Patients with moderate-to-severe TAO had significantly lower FA values and higher MD values (P < 0.05). FA values were negatively correlated with CAS but had no obvious correlations with the degree of exophthalmos. MD values had no obvious correlations with CAS or the degree of exophthalmos.

CONCLUSION

DTI parameters of the intraorbital optic nerves were significantly altered in moderate-to-severe patients before onset of clinical optic nerve dysfunction and may, therefore, be used as an imaging biomarker for assessing the disease.

Beyond dry eye: how co-morbidities influence disease phenotype in dry eye disease

Dry Eye Disease (DED) is a complex and multifactorial disorder of tear homoeostasis that results in pain, visual disturbance, and ocular surface damage. It is highly prevalent around the world and is associated with many co-morbidities that may contribute to or exacerbate symptoms and signs of disease and affect disease phenotype. However, DED is not one disease and can manifest with a variety of symptoms and/or signs. In this review, we discuss relationships between various co-morbidities and DED phenotypes. For example, individuals with immune mediated diseases, like Sjögren's Syndrome and Graft versus Host Disease, often present with aqueous tear deficiency (ADDE) in the setting of lacrimal gland dysfunction. Individuals with disorders that affect the periocular skin, like rosacea and seborrhoeic dermatitis, often present with evaporative dry eye (EDE) in the setting of eyelid and/or meibomian gland abnormalities. Individuals with pain related disorders, such as chronic pain syndrome and migraine, often present with ocular pain out of proportion to tear film abnormalities, often with accompanying corneal nerve hypersensitivity. Individuals with diabetes mellitus often present with an epitheliopathy in the setting of decreased sensation (neurotrophic keratitis). While not absolute, understanding relationships between co-morbidities and DED phenotypes can help tailor a therapeutic plan to the individual patient.

Diffusion Tensor Imaging Technology to Quantitatively Assess Abnormal Changes in Patients With Thyroid-Associated Ophthalmopathy

Objective

We aim to investigate the feasibility of using diffusion tensor imaging (DTI) to evaluate changes in extraocular muscles (EOMs) and lacrimal gland (LG) in patients with thyroid-associated ophthalmopathy (TAO) and to evaluate disease severity.

Materials and Methods

A total of 74 participants, including 17 healthy controls (HCs), 22 patients with mild TAO, and 35 patients with moderate-severe TAO, underwent 3-Tesla DTI to measure fractional anisotropy (FA) and mean diffusivity (MD) of the EOMs and LG. Ophthalmological examinations, including visual acuity, exophthalmos, intraocular pressure, and fundoscopy, were performed. FA and MD values were compared among patients with different disease severity. Multiple linear regression was adopted to predict the impact of clinical variables on DTI parameters of orbital soft tissue.

Results

TAO patients’ EOMs and LG showed significantly lower FA values and higher MD compared to HCs’ (P < 0.05). Moderate-severe TAO patients’ EOMs and LG had dramatically lower FA and higher MD compared with HCs (P < 0.05). In addition, only the DTI parameters of the medial rectus were considerably different between mild and moderate-severe TAO patients (P = 0.017, P = 0.021). Multiple linear regression showed that disease severity had a significant impact on the DTI parameters of orbital soft tissue.

Conclusion

DTI is a useful tool for detecting microstructural changes in TAO patients’ orbital soft tissue. DTI findings, especially medial rectus DTI parameters, can help to indicate the disease severity in TAO patients.

Lacrimal gland enlargement and tear film changes in acromegaly patients: A controlled study

PURPOSE

Evaluation of the lacrimal gland volume (LGV) and its correlation with tear film functions, serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels in acromegaly patients compared to a control group was aimed.

METHODS

This prospective case-control study included the eyes of 38 patients with uncontrolled (UA) and 48 patients with controlled acromegaly (CA) and 44 patients with nonfunctioning pituitary adenoma. LGV of the patients was evaluated at the baseline, 3rd, and 6th-month visits with magnetic resonance imaging. Schirmer's test, tear breakup time (TBUT), and ocular surface disease index (OSDI) scores were evaluated at the same visits. Their correlation with serum IGF-1 and GH was investigated. Main outcome measure was the difference in mean LGV.

RESULTS

The mean LGV of the acromegaly patients at the baseline visit (116.0 ± 33.2 mm³) and the 3rd-month visit (119.5 ± 36.4 mm³) was higher than the control group (65.2 ± 22.3 mm³ and 63.2 ± 22.3 mm³, respectively; p < 0.001) without any significant difference between the UA and CA patients in the LGV in three consecutive visits (p > 0.05). Among all patients, IGF-1 and GH levels showed a positive correlation with the LGV (p < 0.001; r = 0.52; r = 0.6, respectively). However, Schirmer, TBUT, and OSDI scores did not show any difference among the three groups at each visit (p > 0.05).

CONCLUSION

Acromegaly patients may have larger lacrimal glands compared to the controls and this increase correlated with the increased IGF-1 and GH levels. Lacrimal gland volume may have no effect on its tear film related functions.

Evaluation of extraocular muscles in patients with thyroid associated ophthalmopathy using apparent diffusion coefficient measured by magnetic resonance imaging before and after radiation therapy

BACKGROUND

Thyroid-associated ophthalmopathy (TAO) is an autoimmune orbital disease characterized by edema of extraocular muscles (EOMs).

PURPOSE

To characterize the inflammation of EOMs in patients with TAO before and after radiation therapy using apparent diffusion coefficient (ADC) and to analyze the correlation between ADC and clinical activity of TAO.

MATERIAL AND METHODS

The ADCs of superior rectus (SR), inferior rectus (IR), medial rectus (MR), and lateral rectus (LR) muscles were measured in 52 eyes of 26 patients with TAO before and three months after orbital radiation therapy. In addition, 38 eyes of 20 healthy volunteers were included. The clinical activity score (CAS) was evaluated. The ADC maps were reconstructed and measured on the coronal diffusion-weighted imaging (DWI) sequence and calculated in mm²/s.

RESULTS

The mean ADCs of EOMs before treatment were 1.42 ± 0.23 in SR, 1.37 ± 0.23 in IR, 1.41 ± 0.21 in MR, and 1.28 ± 0.25 in LR. The mean ADCs after treatment were 1.27 ± 0.18, 1.22 ± 0.26, 1.30 ± 0.22, and 1.15 ± 0.21, respectively. The ADCs were significantly decreased after treatment (all P < 0.001). The ADCs of patients with TAO were significantly higher than those of controls. There was a statistically significant correlation between the mean ADCs and the CAS in each patient with TAO both before and after treatment (before: r = 0.520; P < 0.001; after: r = 0.625; P < 0.001).

CONCLUSION

The ADC values of EOMs can be exploited as a quantitative indicator to evaluate the clinical activity and monitor the therapeutic responses of patients with TAO.

Usefulness of readout-segmented EPI-based diffusion tensor imaging of lacrimal gland for detection and disease staging in thyroid-associated ophthalmopathy

Background

Dysfunction of lacrimal gland (LG) gains increasing attention in patients with thyroid-associated ophthalmopathy (TAO), while the underlying pathological change is still not fully established. This study aimed to evaluate the utility of readout-segmented echo-planar imaging (rs-EPI)-based diffusion tensor imaging (DTI) in non-invasively detecting microstructural alterations of LG in patients with TAO, as well as in discriminating disease activity.

Methods

Thirty TAO patients and 15 age- and sex- matched healthy controls, who underwent rs-EPI-based DTI, were retrospectively enrolled. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of LG, and clinical-endocrinological variables were collected and compared. The correlations between FA and ADC values of LG and serum thyroid biochemical markers were also assessed.

Results

TAO group showed significantly lower FA (P < 0.001) and higher ADC (P = 0.014) of LG than healthy group. Active subgroup had significantly lower FA (P < 0.001) and higher ADC (P < 0.001) than inactive subgroup. In TAO group, FA of LG was significantly and negatively correlated with TRAb (r=-0.475, P = 0.008), while ADC of LG showed no significant correlation (P > 0.05). The area under receiver operating characteristic curve of FA was significantly greater than that under curve of ADC for discriminating disease activity (0.832 vs. 0.570, P = 0.009).

Conclusions

rs-EPI-based DTI is a useful tool to characterize the microstructural change of LG in patients with TAO. The derived metrics, particularly FA, can help to reveal disease activity.

Utility of multi-parametric quantitative magnetic resonance imaging of the lacrimal gland for diagnosing and staging Graves' ophthalmopathy

PURPOSE

To explore radiological changes of the lacrimal gland (LG) in Graves' ophthalmopathy (GO) based on multi-parametric quantitative MRI and its clinical utility in LG diagnosis and activity in GO.

METHODS

We enrolled 99 consecutive patients with GO (198 eyes) and 12 Graves' Disease (GD) patients (24 eyes) from July 2018 to June 2020. Clinical, laboratory, and MRI data were collected at the first visit. Based on clinical activity scores, eyes with GO were subdivided into active and inactive groups. T2-relaxation time (T2) and the absolute reduction in T1-relaxation time (ΔT1) were determined. After MRI and processing, we performed descriptive data analysis and group comparisons. Novel logistic regression predictive models were developed for diagnosing and staging GO. Diagnostic performance of MRI parameters and models was assessed by receiver operating characteristic curve analysis.

RESULTS

LG in GO group had significantly higher T2 and ΔT1 values than the GD group [106.25(95.30,120.21) vs. 83.35(78.15,91.45), P<0.001, and 662.62(539.33,810.95) vs. 547.35(458.62,585.57), P = 0.002, respectively]. The GO group had higher T2 of LG indicating higher disease activity [110.93(102.54,127.67) vs. 93.29(87.06,101.96), P < 0.001]. Combining T2 and ΔT1 values of LG, Model I had higher diagnostic value for distinguishing GO from GD (AUC=0.94, 95 %CI: 0.89,0.99, P<0.001). Meanwhile, T2 of LG had higher diagnostic value for grading GO activity (AUC = 0.84, 95 %CI: 0.76,0.92, P<0.001).

CONCLUSIONS

Multi-parametric quantitative MRI parameters of the LG in GO were significantly altered. Novel models combining LG T2 and ΔT1 values showed excellent predictive performances in diagnosing GO. Furthermore, T2 of LG showed practical utility for staging GO.

Value of MRI-based radiomics analysis for differentiation of benign and malignant epithelial neoplasms in the lacrimal gland: a retrospective study

BACKGROUND

It is essential to distinguish malignant from benign epithelial neoplasms in the lacrimal gland for different treatment options and prognosis.

PURPOSE

To retrospectively assess the performance of magnetic resonance imaging (MRI)-based radiomics features in the differentiation of benign and malignant epithelial neoplasms in the lacrimal gland.

MATERIAL AND METHODS

Seventy-six consecutive patients with histopathology-proven epithelial neoplasms of the lacrimal gland were enrolled in the study, including 41 benign and 35 malignant neoplasms. Radiomics features were extracted from T2-weighted and post-contrast T1-weighted imaging. The least absolute shrinkage and selection operator method was used to select imaging features and reduce data dimension to discriminate malignant from benign neoplasms in the lacrimal gland. Diagnostic performance of the radiomics model was assessed by receive operation characteristic (ROC) curve and compared with that of radiologists.

RESULTS

Four quantitative image features including inverse difference moment normalized (IDMN), mean deviation (MD), standard deviation (SD), and long-run emphasis (LRE) were selected to distinguish malignant from benign epithelial neoplasms in the lacrimal gland. Area under the curve (AUC) of these four features were 0.88, 086, 0.88, and 0.86, respectively, with 0.93 for the combination model. The model identified malignant epithelial neoplasms from benign group with 89% sensitivity, 93% specificity, and 89% accuracy. There was a significant difference in the diagnostic performance of radiomics model and the radiologists, with AUC of 0.70 for radiologists. The diagnostic performance of radiomics is superior to that of radiologists.

CONCLUSION

MRI-based radiomics analysis has potential for differentiation of benign and malignant epithelial neoplasms in the lacrimal gland.

Retinal nerve fiber layer thickness measured by optical coherence tomography predicts visual recovery after orbital decompression for dysthyroid optic neuropathy

PURPOSE

To determine the prognostic value of optical coherence tomography (OCT) measurement of the peripapillary retinal nerve fiber layer (RNFL) thickness in visual recovery after orbital decompression of patients with dysthyroid optic neuropathy (DON).

METHODS

A total of 52 eyes of 37 patients who underwent orbital decompression for DON between 2013 and 2019 were retrospectively reviewed. We examined peripapillary RNFL thickness, best-corrected visual acuity (BCVA), visual field (VF) for mean deviation (MD) and pattern standard deviation (PSD), and pattern-reversed visual evoked potential (PVEP) for P100 latency and amplitude before and after surgery. Black and white checkerboard square sizes of PVEP were 15 and 60 arcmin (arcminute and minute of angle). Changes in RNFL overall thickness and by quadrant and interocular differences were evaluated and studied regarding changes in BCVA, VF and PVEP.

RESULTS

There was a significant improvement in BCVA, VF, and PVEP, whereas a dramatic reduction in RNFL thickness of all DON patients in global average, temporal, superior, and inferior quadrants (P = 0.005, P = 0.024, P = 0.016, and P = 0.001, respectively) after decompression surgery, except for nasal quadrant (P = 0.057). The preoperative RNFL thickness in each quadrant was negatively correlated with postoperative changes of BCVA and PSD and positively correlated with changes of MD and P100 amplitude at 60 arcmin (all P < 0.05). Except for temporal quadrant (P = 0.125), the preoperative RNFL thickness in other quadrants was positively correlated with postoperative changes of P100 amplitude at 15 arcmin (all P < 0.05). The nasal RNFL thickness was an excellent predictor for improvement in BCVA by 20/25 or better and in MD by 10 dB or more after surgery, whose cutoff value was 73.50 μm, while the inferior and superior RNFL thickness could act as a predictor for improvement in P100 amplitude by 5 μV or more at 60 arcmin and at 15 arcmin, respectively, whose cutoff value was, respectively, 143.00 μm and 130.50 μm (all P < 0.05).

CONCLUSION

RNFL thickness measured by OCT was correlated with visual function recovery after decompression surgery in patients with DON, which could also act as a predictor for better visual prognosis.

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

BACKGROUND

Discriminating the stage of thyroid-associated ophthalmopathy (TAO) is crucial for the treatment strategy and prognosis prediction. Utility of conventional magnetic resonance imaging in the disease staging is limited.

PURPOSE

To investigate the performance of T2 mapping based on different region of interest (ROI) selection methods in the staging of TAO.

MATERIAL AND METHODS

Thirty-two patients with TAO were retrospectively enrolled. Two radiologists independently measured the T2 relaxation time (T2RT) of extraocular muscles using two different ROIs (hotspot [ROI_HS]: T2RT-hot; single-slice [ROI_SS]: T2RT-mean, T2RT-max, T2RT-min). Independent-samples t test, Wilcoxon signed rank test, Spearman correlation analysis, receiver operating characteristic (ROC) curves analyses, multiple ROC comparisons, and intra-class correlation coefficient (ICC) were used for statistical analyses.

RESULTS

No significant difference was found in the measuring time between ROI_HS and ROI_SS methods (P = 0.066). T2RT-mean demonstrated the highest ICC for measurement, followed by T2RT-max and T2RT-min, and T2RT-hot showed the poorest reproducibility. Active TAOs showed significantly higher values for all the T2RTs than inactive mimics (all P < 0.001). Significant positive correlations were found between T2RTs and CAS (all P < 0.005). T2RT-hot and T2RT-max showed significantly higher areas under the curve than that of T2RT-mean (P = 0.013 and 0.024, respectively), while the difference between T2RT-hot and T2RT-max was not significant (P = 0.970).

CONCLUSION

The T2RTs derived from both ROI selection methods could be useful for the staging of TAO. The results of measuring time, reproducibility, and diagnostic performance suggest that T2RT-max would be the optimal indicator for staging.

Multi-parametric arterial spin labelling and diffusion-weighted magnetic resonance imaging in differentiation of grade II and grade III gliomas

Purpose

To assess arterial spin labelling (ASL) perfusion and diffusion MR imaging (DWI) in the differentiation of grade II from grade III gliomas.

Material and methods

A prospective cohort study was done on 36 patients (20 male and 16 female) with diffuse gliomas, who underwent ASL and DWI. Diffuse gliomas were classified into grade II and grade III. Calculation of tumoural blood flow (TBF) and apparent diffusion coefficient (ADC) of the tumoral and peritumoural regions was made. The ROC curve was drawn to differentiate grade II from grade III gliomas.

Results

There was a significant difference in TBF of tumoural and peritumoural regions of grade II and III gliomas (p = 0.02 and p =0.001, respectively). Selection of 26.1 and 14.8 ml/100 g/min as the cut-off for TBF of tumoural and peritumoural regions differentiated between both groups with area under curve (AUC) of 0.69 and 0.957, and accuracy of 77.8% and 88.9%, respectively. There was small but significant difference in the ADC of tumoural and peritumoural regions between grade II and III gliomas (p = 0.02 for both). The selection of 1.06 and 1.36 × 10^-3 mm²/s as the cut-off of ADC of tumoural and peritumoural regions was made, to differentiate grade II from III with AUC of 0.701 and 0.748, and accuracy of 80.6% and 80.6%, respectively. Combined TBF and ADC of tumoural regions revealed an AUC of 0.808 and accuracy of 72.7%. Combined TBF and ADC for peritumoural regions revealed an AUC of 0.96 and accuracy of 94.4%.

Conclusion

TBF and ADC of tumoural and peritumoural regions are accurate non-invasive methods of differentiation of grade II from grade III gliomas.