Diagnostic Power Of The Optic Neuritis And Prognosis Of The Visual Outcomes In Optic Neuritis Using Multi-Parametric MR Imaging

Purpose:To investigate the use of field-of-view optimized and constrained undistorted single shot diffusion tensor imaging(FOCUS-DWI)of the chiasma and optic nerve abnormalities of acute optic neuritis(AON),and to compare the technique with conventional diffusion tensor imaging(C-DWI).Materials and Methods:FOCUS-DWI was performed of 36 AON patients with field of view(FOV)of 180 × 90 mm and C-DWI with FOV of 180 × 180 mm.Two readers assessed five different aspects of image quality using five-point Likert scales.To compare axial and coronal views of FOCUS-DWI,different portions of the optic nerve and chiasma were assessed.The above results were analyzed using the Wilcoxon Signed-Rank Test test.The ADC values of AON lesions on C-DWI and axial FOCUS-DWI were evaluated,and the intra-observer and intra-observer ADC values were evaluated for consistency.Results:FOCUS-DWI was superior to C-DWI in all aspects of the image evaluations(P<0.0001).The kappa coefficients(k)of FOCUS-DWI were moderate(0.4-0.75)or substantial(>0.75)for all the image quality categories.In the FOCUS-DWI sequence,the structural conspicuity of the coronal view was significantly superior to the axial view in the canalicular and cisternal portion of the optic nerve,as well as in the chiasma(P<0.0001),although there was no difference in the orbital part of the optic nerve.ADC values of the C-DWI were superior to the FOCUS-DWI(P<0.05).Conclusions:The FOCUS-DWI technique can provide substantial improvements in different aspects of optic nerve and chiasma image quality on 3-T MRI.Purpose:To explore the clinical value of multi-parametric MRI with T2WI,CE-T1WI and DWI in diagnosis of optic neuritis.Materials and methods:According to inclusion and exclusion criteria,50 people of normal control,62 patients of acute optic neuritis(ON)and 56 patients of chronic ON were prospective screened.MRI examination including iterative decomposition of water and fat with echo asymmetric and least-squares estimation T2-weighted imaging(IDEAL-T2WI),contrast-enhanced T1-weighted imaging(CE-T1WI),and field-of-view optimized and constrained undistorted single shot diffusion weighted imaging(FOCUS-DWI).Written informed consent was obtained from all subjects.Two radiologists respectively evaluated the images of IDEAL-T2WI,CE-T1WI and FOCUS-DWI on all subjects and also evaluated the different part of optic nerve(the orbital portion,,the canalicular and cisternal portion)on all subjects.The following four parts of images were evaluated by the same radiologists in consensus:protocol 1(T2WI+CE-T1WI),protocol 2(T2WI+FOCUS-DWI),protocol 3(CE-T1WI+FOCUS-DWI),and protocol 4(T2WI+CE-T1WI+FOCUS-DWI).The current clinical comprehensive diagnosis and follow-up results of ON were used as the gold standard.The sensitivity,specificity,positive predictive value and negative predictive value were calculated for all the images.McNemar test was employed to evaluate the differences on sensitivity and specificity.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different methods.The Z test was used to compare the difference in area under the ROC curves(AUC)for the diagnosis of acute ON among the three sequences and their four combinations.The results were corrected by the Bonferroni’s multiplecorrection and P value<0.05/21=0.00238 was considered as significant differences.Corroboration of observations made by the two radiologists was achieved with kappa coefficient.Results:There were 74 optic nerves of 62 acute ON patients,73 optic nerves of 56 chronic ON patients and 73 optic nerves of 50 normal controls qualified for image quality.The diagnostic accuracy rates of acute and chronic ON were highest in scheme 1(0.947,0.816).The sensitivity of the three sequences of the lesion in orbital segment was higher than the others.The sensitivity of the canalicular and cisternal portion was better on IDEAL-T2WI and CE-T1WI than FOCUS-DWI(P<0.05).There was no statistically significant difference between T2WI and CE-T1WI(P<0.05).The AUC in predicting the acute ON was 0.878,0.892,0.783,0.945,0.843,0.904 and 0.884 for the 3 sequences and the 4 combination scheme respectively.The AUC of protocol 1 was the highest,and the AUC of protocol 1 was significantly higher than protocol 2(P<0.0001).The AUC in predicting chronic phase ON was respectively 0.658,0.788,0.596,0.808,0.678,0.774,and 0.781 for the combination of 3 sequences and 4 sequences;the AUC of protocol 1 was the highest,the AUC of protocol 1 was significantly higher than that of protocol 2(P<0.0001).Conclusion:The use of multi-parameter MRI can help improve the diagnostic accuracy of ON.The diagnostic value of T2WI+CE-T1WI combination or CE-T1WI+FOCUS-DWI combination are more valuable in the diagnostic ability than the others for acute ON.Multi-parametric MRI helps to improve the diagnostic accuracy of chronic ON,but it has no significant increase compared with CE-T1WI.The diagnostic value of FOCUS-DWI alone is low.Purpose:The main treatment method for patients with neuromyelitis optica(NMO)related optic neuritis(NMO-ON)in the clinical acute phase is high-dose methylprednisolone therapy and when some patients cannot tolerate corticosteroids or show poor efficacy and poor vision prognosis,then plasma exchange(PE)therapy were employed.It has been confirmed that patients with poor vision prognosis should be applied with PE therapy as soon as possible.In this study,the radiomics analysis of brain DTI was employed to predict the vision prognosis of patients with NMO-ON after IVMP treatment,which is very important for the development of clinical clinical treatment plan.Materials and methods:57 NMO-ON patients who underwent DTI after IVMP therapy were enrolled.DTI measures were selected using the Elastic-net penalty and were subsequently combined in a logistic regression model to predict the visual outcomes of the NMO-ON patients after IVMP.The prediction performance was assessed by area under the receiver operating characteristic curve(AUC),classification accuracy(ACC),sensitivity,specificity,positive and negative predictive values(PPV and NPV).Results:The Radiomics prediction model obtained ACC of 73.68%(P=0.002),AUC of 0.7931,sensitivity of 0.6207,specificity of 0.8571,PPV of 0.8182 and NPV of 0.6857 in predicting visual outcomes of the NMO-ON patients after IVMP treatment.The selected DTI measures revealed white matter impairments related to the visual outcomes in the white matter tracts of vision-related regions,motor-related regions,and corpus callosum.The white matter impairments were found significantly correlated with the disease duration and the length of lesions in the optic nerve.Conclusion:Radiomics analysis of DTI data had great potential in predicting visxual outcomes of NMO-ON patients after IVMP therapy.