Objective To explore the feasibility of the applicatoin of readout-segmented echo-planar imaging (RS-EPI) at 3.0T MR of the orbit DWI and compared with single-shot echo-planar imaging (SS-EPI).Methods Forty-two volunteers underwent both standard SS-EPI and RS-EPI DWI of the orbit at a 3.0T MR unit.Two sets of DWI images were independently qualitatively scored in the number of distinguishable normal structures,fat suppression,ghosting artifact and overall image quality.SNR of the vitreous body,geometric distortion ratio (GDR) in both anterior-posterior (AP) and right-left (RL) direction,and ADC value of the vitreous body and pons were also quantitatively calculated and compared between two sets of DWI images.The statistical analysis was performed.Results For qualitative assessment,the RS-EPI was superior to SS-EPI on the number of distinguishable normal structures (P=0.009 0),ghosting artifact (P＜0.000 1),and overall image quality (P＜0.000 1),while no significant difference was found on fat suppression (P=0.753 9).For quantitative assessment,RS-EPI had significantly lower GDR than the SS-EPI in both AP and RL direction (P=0.001 4,0.001 7).The SNR in RS-EPI was significantly lower than that of SS-EPI (P=0.004 0).Meanwhile,there was no significant difference of ADC on vitreous body and pons between RS-EPI and SS-EPI (P=0.143 8,0.126 2).Conclusion The RS-EPI can provide better image quality than SS-EPI protocol in orbital DWI at 3.0T MR imaging.

Objective To evaluate the role of conventional and functional MR in the diagnosis of orbital mucosa-associated lymphoid tissue lymphoma (MALToma).Methods Twenty-two patients with pathologically confirmed orbital MALToma were enrolled in our study.The number,location,morphology,involvement of surrounding structure and imaging features were evaluated.Apparent diffusion coefficient (ADC) values derived from diffusion weighted imaging and time-intensity curve (TIC)pattern derived from dynamic contrast enhanced MRI were assessed. Results Orbital MALToma occurred unilaterally in 1 7 cases and bilaterally in 5 cases.Anterior orbit preseptal region was involved most frequently (20 cases),followed by intraconal(19 cases),extraxonal (17 cases)and lacrimal fossa (12 cases)regions.Most cases showed as homogeneously iso-intensity on both T1 and T2 weighted images.Mean ADC value of the lesions was (0.61 ± 0.08)× 10 -3 mm2/s.A washout-type TIC pattern was observed in 1 5 cases,while plateau pattern was found in 7 cases.Conclusion Conventional MRI can assist in describing the extent,while the functional MRI can quantitatively reflect the histo-pathological features of orbital MALToma.Combination of conventional and functional MRI can help the diagnosis of orbital MALToma.

Objective To evaluate the diagnostic and staging value of orbital structures quantitative measurement with 3T mag-netic resonance imaging in patients with Graves’ophthalmopathy (GO).Methods Twenty-three GO patients (patient group)and eighteen healthy volunteers (contrast group)were enrolled.Quantitative measurement of orbital structures including exophthalmos values,fatty tissue thickness of the inner side of eye balls,cross-sectional areas of extraocular muscles and signal intensity ratios of extraocular muscles to the ipsilateral temporal muscles (SIR values),and they were compared between two groups.Correlations be-tween the quantitative values and clinical active score (CAS)were accessed.Receiver operating characteristic (ROC)analysis was performed to evaluate the most relevant quantitative parameter and its diagnostic value in discriminating active from inactive GO pa-tients.Results There were significant differences between the GO group and contrast group regarding to all the quantitative parame-ters (P <0.05).Strong correlation was found between SIR values and CAS (r =0.730,P <0.001 ).Significant difference of SIR was found between patients with active GO and inactive GO (P =0.002),and a cut off value of 3.25 might be the critical threshold value,with diagnostic sensitivity of 81.8% and specificity of 83.3% respectively.Conclusion Quantitative measurement of orbital structures with 3T MR imaging could provide assistant in diagnosing and staging of GO.

Objective To investigate the diagnostic value of conventional MRI combined with DWI in the differential diagnosis of orbital lymphoproliferative disorders (LPD). Methods As a retrospective study, 42 patients were enrolled, including 23 orbital lymphoma and 19 benign orbital LPD confirmed pathologically or clinically. These patients underwent conventional MR, DWI and contrast?enhanced MRI examination of orbit. Qualitative MR imaging features [location, margin, patient ratio of involved quadrants (≥2), signal intensity,“flow void sign”, sinusitis] and quantitative features [ADC and contrast enhanced ratio of the lesion to temporal muscle (CER)] were evaluated. Chi?square test and t test were used for the analysis of qualitative and quantitative features between lymphoma and benign orbital LPD groups, respectively. Multivariate Logistic regression analysis was employed to identify the significant variable for predicting malignant LPD. ROC analysis was used to evaluate the ability of the diagnostic models established based on identified variables. Results “Flow void sign”(9 lymphomas and 17 benign LPDs) and sinusitis (5 lymphomas and 13 benign LPDs) were statistically significant (P<0.05). The MR imaging features [location, margin, patient ratio of involved quadrants (≥2), and signal intensity] had no significant difference between the two groups (P>0.05). Both ADC [(0.79±0.09)×10?3 mm2/s of lymphoma, (1.29±0.35)×10?3 mm2/s of benign LPD] and CER (1.43±0.17 of lymphoma, 1.79±0.31 of benign LPD) between the two groups had significant difference (t=-6.630, -8.257;P<0.01). Multivariate logistic regression analysis showed that ADC value, CER and“flow void sign”were significant variables for predicting malignant orbital LPD (P<0.05). ROC curve showed that ADC value was the most significant single variable in differentiating orbital LPD [threshold value, 0.74 × 10- 3 mm2/s; areas under ROC curve (AUC), 0.97; sensitivity, 87.0%; specificity, 94.7%]. Combination of ADC and CER could further improve the specificity in differentiating benign from malignant orbital LPD (AUC, 0.90;sensitivity, 78.3%;specificity, 100.0%, accuracy 88.1%). Conclusions ADC, CER and“flow void sign”on T2WI were significant variables for predicting malignant orbital LPD. ADC value was the most significant single variable. Combination of ADC and CER could further improve the specificity in differentiating benign from malignant orbital LPD.

Objective:To investigate the value of multi-parametric analysis based on dual-layer detector spectral CT (DLCT) in predicting the initial recurrence risk for papillary thyroid carcinoma (PTC).Methods:From November 2021 to October 2022, 102 PTC patients confirmed by pathology were retrospectively collected at the First Affiliated Hospital of Nanjing Medical University in this cross-sectional study. There were 25 males and 77 females, with an age of (42±13) years old. The initial recurrence risk assessment for PTC patients was categorized into a low-risk group (75 cases) and an intermediate-high-risk group (27 cases). Clinical data, including age, gender, body mass index, history of nodular goiter, history of Hashimoto thyroiditis, and preoperative thyroid function, were collected. Tumor morphological features, including size, location, shape, aspect ratio, the degree of thyroid capsule contact, calcification, and cystic change, were evaluated. Quantitative DLCT parameters, including iodine concentration (IC), standardized iodine concentration (NIC), effective atomic number (Z eff), standardized effective atomic number (NZ eff), electronic density (ED), CT values under different energy levels (40-200 keV, 30 keV intervals) and slope of energy spectrum curve (λ HU) both in the arterial and venous phase were measured. The differences in clinical, morphological features, and spectral CT quantitative parameters between the two groups were compared using independent sample ttest, Mann-Whitney U test, or χ2 test. Multivariate logistic regression analyses were used to construct three models based on clinical and morphological features, quantitative DLCT parameters and their combination, respectively. The receiver operating characteristic curve was used to evaluate the predictive performance of these models for the initial recurrence risk of PTC patients, and the area under the curve (AUC) was compared using the DeLong test. Results:Significant differences were found in gender, lesion long diameter, lesion short diameter and calcification between the low-risk group and intermediate-high-risk groups ( P<0.05). The arterial phase IC, arterial phase Z eff, arterial phase λ HU, arterial phase CT 40 keV, venous phase NIC and venous phase NZ eff in intermediate-high-risk group were significantly lower than those in the low-risk group ( P<0.05). The logistic regression analysis revealed that the clinical model included gender ( OR=2.895, 95% CI 1.047-8.002, P=0.040) and lesion long diameter ( OR=1.142, 95% CI 1.042-1.251, P=0.004), with an AUC of 0.720, sensitivity of 63.0%, and specificity of 78.7% in predicting the initial recurrence risk of PTC patients. The DLCT quantitative parameter model included arterial phase IC ( OR=0.580, 95% CI 0.370-0.908, P=0.017), venous phase NIC ( OR=0.077, 95% CI 0.011-0.536, P=0.010), and venous phase NZ eff ( OR=0.002, 95% CI 0.001-0.103, P=0.009), with an AUC of 0.774, sensitivity of 71.9%, and specificity of 70.0%. The AUC of the combined model was 0.857, with a sensitivity of 74.1%, and specificity of 88.0%, outperforming the clinical model ( Z=2.92, P=0.004) and the DLCT quantitative parameter model ( Z=2.07, P=0.046). Conclusion:Multi-parametric analysis based on DLCT can help predict the initial recurrence risk for PTC, and combining it with clinical and morphological features, the predictive accuracy can be improved.

Objective To evaluate the value of quantitative analysis of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion weighted imaging (DWI) for differentiating malignant from benign orbital lymphoproliferative disorder(OLPD). Methods Forty-three patients with OLPDs(20 patients with benign OLPDs and 23 patients with orbital lymphoma) confirmed by histopathology or clinical follow-up were enrolled in this retrospective study.Quantitative parameters of DCE-MRI including volume transfer constant (Ktrans), flux rate constant (Kep), and extravascular extracellular volume fraction (Ve) and mean apparent diffusion coefficient(ADC)values were obtained. χ2test and t test were used to compare the differences of qualitative and quantitative parameters between two groups. Receiver operating characteristic (ROC) curve analyses were used to evaluate the diagnostic ability of each parameter and its combination. Results Malignant group showed significantly lower mean ADC values and higher Kepvalues than benign group [ADC:(0.674±0.126)×10-3mm2/s vs(1.030±0.304)×10-3mm2/s,P<0.001;Kep:(1.299±0.566)/min vs(0.787± 0.311)/min, P= 0.001], while no significant differences was found on Ktrans(P= 0.637) and Ve(P= 0.023). ROC analyses results indicated that,a sensitivity of 95.7%,specificity of 80.0% and area under curve(AUC) of 0.896 could be obtained,when using ADC=0.809×10-3mm2/s as the cut-off value.Setting the Kepvalue of 0.863/min as the cut-off value, a sensitivity of 91.3%, specificity of 75.0% and AUC of 0.848 could be obtained. When combination of mean ADC and Kepwas used, optimal diagnostic performance could be obtained (AUC, 0.926;sensitivity, 91.3%;specificity, 90.0%). Conclusion Mean ADC values and Kepare significant variables in predicting malignant OLPDs. Combination of DWI and DCE-MRI can further improve the diagnostic capability in differentiating malignant from benign OLPDs.

Objective:To investigate the value of magnetization transfer imaging (MTI) and fat suppression T 2WI (FS-T 2WI) in predicting the clinical activity of Graves ophthalmopathy (GO). Methods:From October 2020 to July 2021, 64 GO patients were prospectively enrolled in the First Affiliated Hospital of Nanjing Medical University. According to the clinical activity score (CAS), the patients were divided into active group (CAS≥3, 39 patients and 78 eyes) and inactive group (CAS<3, 25 patients and 50 eyes). The coronal MTI and FS-T 2WI were scanned for pre-treatment assessment. Magnetization transfer ratio (MTR) of extraocular muscles, and signal intensity ratio (SIR) between extraocular muscles and temporalis were measured, respectively. The independent-sample t-test was used to compare the MTR and SIR between two groups. The correlations between MRI parameters and CAS were analyzed using Spearman correlation analysis. The receiver operating characteristic (ROC) curve was performed to evaluate the value of each and combined parameters for predicting the clinical activity of GO. The DeLong test was used to compare the area under the curve (AUC). Results:The MTR of active group and inactive group were 0.45±0.04 and 0.51±0.04, respectively, the difference was statistically significant ( t=7.62, P<0.001). The SIR were 3.4±0.6 and 2.6±0.5, respectively, and the difference was also statistically significant ( t=-8.20, P<0.001). MTR was negatively correlated with CAS ( r=-0.46, P<0.001), while SIR was positively correlated with CAS ( r=0.63, P<0.001). The AUC of MTR, SIR and the combination of MTR and SIR for predicting the clinical activity of GO were 0.840, 0.845 and 0.905, respectively. The combination of MTR and SIR showed higher performance than MTR or SIR alone, and the differences were statistically significant ( Z=2.61, P=0.009; Z=2.15, P=0.032). Conclusions:The quantitative parameters of MTI and FS-T 2WI, namely MTR and SIR, can be used to evaluate the clinical activity of GO. Integrating MTI and FS-T 2WI can improve the diagnostic efficiency.

Objective Toinvestigatetheclinicalvalueofreadoutsegmentationoflongvariableecho-trainsdiffusion-weightedimaging (RESOLVE-DWI)inthediagnosisandstagingofthyroid-associatedophthalmopathy(TAO).Methods Atotalof30consecutivepatientswith TAOand30healthycontrols(HCs)whounderwentRESOLVE-DWIwereenrolledinourstudy.ADCvaluesofextraocularmuscles (superiorrectus,inferiorrectus,medialrectusandlateralrectus)were measuredandcomparedbetween TAOsand HCs,active TAOsandinactiveTAOs,orinactiveTAOsandHCs.ROCanalysiswasperformedtoevaluatethediagnosticvalueofsignificantparametersfor discriminatingactivefrominactiveTAOs.Results TheADCvaluesofallextraocularmusclesinTAOsweresignificantlyhigherthan thoseinHCs(P<0.05).Meanwhile,alltheextraocularmusclesinactiveTAOsshowedsignificantlyhigherADCvaluesthanthose ininactiveTAOs(P<0.05),exceptlateralrectus(P=0.267).WhilstnosignificantdifferenceswerefoundontheADCvaluesofall extraocularmusclesbetweeninactiveTAOsandHCs(P>0.05).ROCanalysisresultsindicatedthattheADCvalueofmedialrectus showedtheoptimalstagingefficacy(cutoffvalue,1.40×10-3 mm2/s;AUC,0.766;sensitivity,92.1%;specificity,59.1%).Conclusion RESOLVE-DWIanditsderivedADCvaluesofextraocularmusclescanassistinthediagnosisofTAO.TheADCvalueofmedial rectushastheoptimalefficacyontheevaluationofitsclinicalactivity.

Objective:To explore the diagnostic value of radiomics based on arterial-venous mixed images derived from dual-energy CT (DECT) data in diagnosis of cervical lymph nodes (LNs) metastasis of papillary thyroid cancer (PTC).Methods:From June 2017 to December 2018, eighty-four patients with preoperatively DECT scanning and pathologically confirmed PTC (129 non-metastatic LNs and 97 metastatic LNs) in the First Affiliated Hospital of Nanjing Medical University were included in this study. The clinical and imaging data of all patients were retrospectively analyzed. The training cohort consisted of 62 PTC cases with 156 LNs (91 non-metastatic LNs and 65 metastatic LNs). An independent validation cohort consisted of 22 PTC patients with 70 LNs (38 non-metastatic LNs and 32 metastatic LNs). Semi-automatic LNs segmentation was conducted on arterial-venous mixed images derived from DECT using Syngo.via Frontier Radiomics software. Totally 1 226 radiomics features were extracted from arterial-venous mixed images for each LN. The least absolute shrinkage and selection operator (LASSO) regression was applied for radiomics features selection and signature building. The logistic regression modeling was used to construct diagnostic models based on the CT image features of LNs (model 1), the radiomics signature (model 2) and the combination of the CT image features and radiomics signature (model 3). An intuitive nomogram was plotted for model 3. The ROC curve analyses and area under the curve (AUC) were performed to evaluate the diagnostic efficiency of the three models, with the performances compared using the Delong test.Results:Model 1 was developed with LNs shape, degree of enhancement, pattern of enhancement, calcification and extra nodal extension. Three arterial phase radiomics features were selected and used to establish radiomics signature using LASSO regression (model 2). Model 3 was developed with LNs size, shape, degree of enhancement and radiomics signature. In both the training and validation cohort, model 3 showed the best diagnostic performance (AUC=0.965, 0.933), followed by model 2 (AUC=0.947, 0.910), and both these two models significantly outperformed model 1 (AUC=0.850, 0.846) (training cohort, Z=4.066 and 3.758, P both<0.001; validation cohort, Z=2.871 and 1.998, P=0.017 and 0.042) respectively. Conclusion:The radiomics model based on arterial-venous mixed images derived from DECT data can realize effective diagnosis of LNs metastasis in patients with PTC; and the combination model of radiomics signature with CT image features can further improve the diagnostic accuracy.

Objective:To assess the value of cerebral small vessel disease (CSVD) burden in predicting prognosis in acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion (LVO) after endovascular therapy (EVT).Methods:The study was a cross-sectional study. A total of 242 patients with AIS due to anterior circulation LVO received EVT in the First Affiliated Hospital of Nanjing Medical University from February 2018 to September 2022. The clinical and imaging data of all patients were analyzed retrospectively. On follow-up MRI within 7 days after EVT, CSVD features [white matter hyperintensity (WMH), lacune, perivascular space, cerebral microbleed, cerebral atrophy] and CSVD burden score (0-5) was evaluated. Modified Rankin scale (mRS) score at 90 days after EVT was assessed. Patients were categorized into a mild burden group (0-1 points) and a moderate-severe burden group (2-5 points) based on CSVD burden score. Meanwhile, patients were categorized into a good prognosis group (0-2 points) and a bad prognosis group (3-6 points) based on mRS score at 90 days after EVT. Mann-Whitney U test and χ2 test were used to compare the difference of clinical and imaging indexes between the 2 groups, and variables with P<0.1 in the univariate analysis were included in the multifactorial logistic regression to screen for independent factors to predict the prognosis. Results:There were 169 patients in the good prognosis group and 73 patients in the bad prognosis group out of 242 patients. Compared with the good prognosis group, age, incidence of hyperlipidemia, baseline National Institutes of Health Stroke Scale (NIHSS) scores, incidence of hemorrhagic conversion, CSVD burden scores, incidence of periventricular WMH scores of 3 and/or deep WMH scores≥2, and incidence of moderate-severe cerebral atrophy of patients in the bad prognosis group were higher, and the incidence of complete recanalization was lower (all P<0.05). Multivariate analysis showed hyperlipemia ( OR=8.438, 95% CI 1.691-42.119, P=0.009), baseline NIHSS score ( OR=1.103, 95% CI 1.047-1.162, P<0.001), complete recanalization ( OR=0.131, 95% CI 0.038-0.454, P=0.001) and hemorrhage transformation ( OR=1.952, 95% CI 1.031-3.697, P=0.040) were independent factors for the prognosis of EVT in patients with LVO AIS. There were 157 cases in the mild burden group and 85 cases in the moderate-severe burden group. The 90-day mRS score was higher in the moderate-severe burden group compared with the mild burden group ( Z=-2.24, P=0.025). Conclusion:CSVD burden has some clinical implications in predicting the prognosis of EVT in patients with anterior circulation LVO AIS.