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Objectives: To develop an MRI-based radiomics model to predict postlaminar optic nerve invasion (PLONI) in retinoblastoma (RB) and compare its predictive performance with subjective radiologists' assessment., Methods: We retrospectively enrolled 124 patients with pathologically proven RB (90 in training set and 34 in validation set) who had MRI scans before surgery. A radiomics model for predicting PLONI was developed by extracting quantitative imaging features from axial T2W images and contrast-enhanced T1W images in the training set. The Kruskal-Wallis test, least absolute shrinkage and selection operator regression, and recursive feature elimination were used for feature selection, where upon a radiomics model was built with a logistic regression (LR) classifier. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve and the accuracy were assessed to evaluate the predictive performance in the training and validation set. The performance of the radiomics model was compared to radiologists' assessment by DeLong test., Results: The AUC of the radiomics model for the prediction of PLONI was 0.928 in the training set and 0.841 in the validation set. Radiomics model produced better sensitivity than radiologists' assessment (81.1% vs  43.2% in training set, 82.4vs 52.9% in validation set). In all 124 patients, the AUC of the radiomics model was 0.897, while that of radiologists' assessment was 0.674 ( p < 0.001, DeLong test)., Conclusion: MRI-based radiomics model to predict PLONI in RB patients was shown to be superior to visual assessment with improved sensitivity and AUC, and may serve as a potential tool to guide personalized treatment.

Objective: To optimize the method of acquiring the ONSAS parameter and to access the repeatability of the new method comparing with the traditional one. Methods: This is a cross-sectional study. Standard operation procedure of an optimized method of acquiring the ONSAS sectional area was made against the defect of the traditional method. Ten healthy volunteers (20 eyes) in different ages were recruited from March 2016 to October. Two times of MRI scan were proceeded with the interval of one week. The optimized and traditional methods were both applied for each scanning. The images were analyzed by two ophthalmologists. The rate of high quality images between two groups was compared with matching chi-square test. The orbital subarachnoid space areas between groups at different locations were compared using analysis of variance of repeated measurement data. The ICC between different scans and different ophthalmologists was calculated. Results: The mean age of the volunteers was 43.8±13.1 years old. Male/Female was 1∶1. The rates of high quality images from the optimized method (100%, 83%, 78%) was higher than those of the traditional method(80%, 78%, 70%). The orbital subarachnoid space area at 3 mm, 9 mm and 15 mm behind the eye ball acquired from the new method(7.2±1.8, 6.1±1.8, 5.9±1.4 mm(2)) were bigger than those of the traditional method (9.0±2.9, 7.6±2.4, 7.1±1.6 mm(2)). Statistical significances were found at 9 mm( F= 4.30, P= 0.048) and 15 mm( F= 5.67, P= 0.026) behind the eye ball. The ICC between two different scans (0.879, 0.857, 0.857 vs 0.741, 0.762, 0.639) and two different ophthalmologists (0.864, 0.890, 0.894 vs 0.785, 0.609, 0.753) were higher in the new method group than in the traditional method group. Conclusions: The optimized method of acquiring the parameters of optic nerve subarachnoid space is easier to get the sectional cross area. The measuring reproducibility is better than the traditional one. (Chin J Ophthalmol, 2017, 53: 440-444) .

Background: Indirect traumatic optic neuropathy (ITON) is a devastating cause of permanent visual loss. Axonal degeneration, the characteristic pathological change of ITON, cannot be assessed by conventional imaging. Diffusion tensor imaging (DTI) has been widely used as a sensitive non-invasive imaging technique to obtain information on axonal integrity., Purpose: To study time-dependent changes in ITON patients with DTI and to provide imaging evidence for clinical diagnosis and therapy., Material and Methods: We enrolled 28 subjects with unilateral ITON who underwent detailed ocular examinations and magnetic resonance imaging (MRI) examinations. The differences between injured optic nerve (ON) and contralateral ON were tested. The patients were divided into three groups based on time (from injury to examination). Groups 1, 2, and 3 corresponded to the time taken from injury to examination: <7 days, 7-30 days, and >30 days, respectively. DT magnetic resonance imaging (MRI) differences among the groups were compared, including the relationship between diffusion parameters and mean thicknesses of the peripapillary retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) in the macular area., Results: Compared with contralateral ON, we observed reduced fractional anisotropy (FA) of injured nerves in group 2. Reduced FA and decreased axial diffusivity (λ//) and increased radial diffusivity (λ┴) and mean diffusivity (MD) of injured nerves were observed in group 3. The mean FA value of injured nerves showed a progressive decreasing trend, and mean λ┴ value exhibited a progressive increasing trend. For injured eyes, the MD and λ┴ increases strongly correlated with the decreased mean thicknesses of RNFL and GCC. Conversely, FA was significantly associated with mean RNFL thickness., Conclusion: DT-MRI parameters could be useful biomarkers in detecting ON changes in ITON patients., (© The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Objective: Low cerebrospinal fluid pressure (CSF-P) may be involved in the pathogenesis of glaucoma. We measured the optic nerve subarachnoid space width (ONSASW) as a surrogate for orbital CSF-P in patients with primary open-angle glaucoma (POAG) with normal and high pressure and a control group., Design: Prospective observational study., Participants: The study included 39 patients with POAG; 21 patients had normal pressure (intraocular pressure [IOP] 21 mmHg), and 18 patients had high pressure (IOP >21 mmHg); 21 subjects formed the control group., Methods: By using magnetic resonance imaging (MRI) with fat-suppressed fast recovery fast spin echo (FRFSE) T2-weighted sequence, we determined the ONSASW at 3, 9, and 15 mm posterior to the globe., Main Outcome Measures: The ONSASW and optic nerve diameter., Results: At all 3 measurement locations of 3, 9, and 15 mm, the ONSASW was significantly (P<0.001, P<0.001, and P = 0.003, respectively) narrower in the normal-pressure group (0.67±0.16, 0.55±0.09, and 0.51±0.12 mm, respectively) than in the high-pressure group (0.93±0.21, 0.70±0.12, and 0.62±0.11 mm, respectively) or the control group (0.87±0.15, 0.67±0.07, and 0.61±0.07 mm, respectively). The high-pressure and control groups did not vary significantly at 3, 9, and 15 mm (P = 0.31, P = 0.39, and P = 0.44, respectively). At all 3 measurement locations, ONSASW was narrower in the normal-pressure group compared with the high-pressure and control groups after adjustment for optic nerve diameter (P<0.01). Correspondingly, the width of the optic nerve subarachnoid space measured at 3, 9, and 15 mm behind the globe, respectively, was significantly (all P<0.05) associated with IOP after adjustment for optic nerve diameter and visual field defect., Conclusions: The narrower orbital optic nerve subarachnoid space in patients with POAG with normal pressure compared with high pressure suggests a lower orbital CSF-P in patients with POAG with normal pressure., (Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Objective: Optic neuritis (ON) is defined as an inflammation of the optic nerve and provides a useful model for studying the effects of inflammatory demyelination of white matter. The aim of this study was to assess the diffusion changes in both the optic nerve and optic radiation in patients with acute and chronic ON using diffusion tensor (DT) MRI., Methods: 33 patients with idiopathic demyelinating optic neuritis (IDON) and 33 gender- and age-matched healthy controls were examined with DT-MRI and with T(1) and T(2) weighted MRI., Results: Compared with controls, both first-episode and recurrent patients with IDON in the acute stage showed significantly increased radial diffusivity (λ(⊥)) and decreased mean fractional anisotropy (FA) in the affected nerves. Reduced FA, increased λ(⊥), mean diffusivity (MD) and axial diffusivity (λ(∥)) were determined in patients with subacute IDON. We found no significant difference in the directional diffusivity of optic radiation in patients whose disease had lasted less than 1 year compared with healthy controls. However, significant changes in the FA and λ(⊥) of the optic radiation were detected in patients with disease duration of more than 1 year., Conclusion: These results show the great potential and capacity of DT-MRI measures as useful biomarkers and indicators for the evaluation of myelin injury in the visual pathway.

Aim: To evaluate the efficacy of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) in reducing ocular motion artefacts and improving image quality of orbital magnetic resonance imaging (MRI) at 3 T using an eye surface coil.Materials and Methods: Forty-six patients underwent orbital 3 T MRI using an eye surface coil. The pre-contrast axial T2-wighted (W) PROPELLER and T1 fluid-attenuated inversion recovery (FLAIR) PROPELLER imaging were performed on 21 patients, and conventional T2W and T1W imaging were performed on 25 patients. The ocular motion artefacts, delineation of anatomical structures, depiction of lesions, and image quality were evaluated independently by two radiologists using a five-point scale. The signal-to-noise ratios (SNRs) of anatomical structures and lesions were measured.Results: The interobserver agreement was good to excellent (kappa values from 0.79 to 0.91). PROPELLER sequences had higher scoring than the conventional sequences in all cases (p<0.05). PROPELLER images showed fewer motion artefacts, higher image quality, and more clear delineation of anatomical structures and lesions than the non-PROPELLER images. T2W PROPELLER images produced higher SNRs in lens, vitreous body, lacrimal gland, and lesions than conventional T2W images (p<0.05). T1 FLAIR PROPELLER images showed lower SNRs in lens, vitreous body, medial rectus, lateral rectus, temporalis, and posterior half of optic nerve than conventional T1W images (p<0.05).Conclusion: PROPELLER can effectively reduce ocular motion artefacts and improve image quality, which plays an important role in clearly delineating anatomical structures and lesions on orbital 3 T MRI using an eye surface coil. [ABSTRACT FROM AUTHOR]