The value of whole-lesion intravoxel incoherent motion diffusion weighted imaging based on turbo spin-echo sequence in differential diagnosis of thyroid benign and malignant nodules / 中华放射学杂志

Objective:To assess the diagnostic value of whole-lesion intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) in differentiating benign and malignant thyroid nodules based on turbo spin echo (TSE) sequence.Methods:Totally 57 patients with thyroid nodules diagnosed by pathology were prospectively collected at the Affiliated Lianyungang Hospital of Xuzhou Medical University from March 2019 to December 2019. A total of 62 nodules were included for analysis, including 27 benign nodules and 35 malignant nodules. All patients underwent routine MRI scan and IVIM-DWI based on TSE sequence before surgery. The regions of interest were drawn along the edge of the lesion on multiple consecutive slices to cover the entire nodule, and the apparent diffusion coefficient (ADC), diffusivity (D), pseudo-diffusivity (D *) and quantitation of perfusion fraction (f) values were measured, and the mean value of the multilayer measurement was recorded for further analysis. The differences of the parameters between benign and malignant thyroid nodules were analyzed using independent samples ttest (normal distribution) and Mann-Whitney U test (non-normal distribution). The diagnostic efficacy of parameters with statistical significance was evaluated using the receiver operating characteristics (ROC) curve. Results:The ADC, D and D *values in the malignant nodules were lower than those in benign nodules, the differences were statistically significant ( t=3.821, P=0.001; t=2.034, P=0.046).There were no statistical differences of D * and f values ( t=-1.170, P=0.247; Z=-0.559, P=0.577).The optimal cut-off values of ADC and D were 1.90×10 -3mm 2/s and 1.10×10 -3mm 2/s, with both sensitivity of 81.5%, specificity of 73.5% and 61.8%, respectively. The area under ROC curve of ADC and D were 0.782 and 0.688, and the statistical difference was found ( Z=2.098, P=0.040). Conclusion:The whole-lesion IVIM parameters (ADC and D) based on the TSE sequence provide imaging features for preoperative differentiation of benign and malignant nodules of the thyroid gland.

Analysis of CT features of early asymptomatic active pulmonary tuberculosis in adolescence / 实用放射学杂志

Objective To analyze the CT features in the early stage of asymptomatic active pulmonary tuberculosis (PTB)in adolescence after PTB outbreak.Methods After PTB outbreak in a boarding school of a certain county in northern Jiangsu province,the clinical data, X-ray and CT findings of 47 cases with active PTB were analyzed retrospectively and compared with CT findings after treatment.Results In 47 cases,the incidence of male was higher than that of female,and 27 cases were negative on chest X-ray.The difference of X-ray and CT detection rate in the early stage of active PTB was statistically significant (P<0.001).Of 47 cases,46 patients had pulmonary parenchymal lesions and 1 had pleural effusion on CT.The lesions were found on 58 lobes and 60 lung segments,and 35 cases demonstrate lesions on the upper lobes,22 cases on the lower lobes,1 case on the middle lobe.CT images showed tree-in-bud opacities (68.1%),micronodules (89.4%) and consolidation (21.3%).All of patients got better after antituberculous therapy.Conclusion Active PTB should be considered first when CT scan shows micronodules or tree-in-bud signs in adolescences with PTB exposure.

3.0T MR three-dimensional time-of-flight and fast imaging employing steady state acquisition sequences in pre-operative evaluation on spatial relationship among trigeminal nerve, facial nerve and peripheral vessels / 中国医学影像技术

Objective To investigate the value of three dimensional time-of-flight (3D-TO)F) and three dimensional fast imaging employing steady state acquisition (3D-FIESTA)sequences in evaluation on spatial relationship among trigeminal nerve,facial nerve and peripheral vessels before microvascular decompression(MVD)with 3.0 T MR.Methods Data of MRI of 36 patients with trigeminal neuralgia (TN) and 31 with hemifacial spasm (HFS) before MVD were analyzed retrospectively.The intra-observer agreement for the spatial relationship among trigeminal nerve,facial nerve and adjacent blood vessels were observed.The differences of occurrence rates of neurovascular compression (NVC) of symptomatic side and asymptomatic side in TN and HFS patients were compared.Taking surgical results as the gold standards,the diagnostic efficacy for neurovascular relationships of symptomatic side with 3D-TOF and 3D-FIESTA sequences were calculated.Results The consistency between two observers in assessing relationship of trigeminal nerve,facial nerve and adjacent blood vessels of symptomatic and asymptomatic was good (all Kappa≥0.75,all P＜0.001).In both of TN and HFS patients,the occurrence rates of NVC of symptomatic side were significantly higher than those of asymptomatic side (x2=26.13,20.81,both P＜ 0.001).The accuracy,sensitivity,specificity,positive predictive value and negative predictive value of 3D-TOF and 3D-FIESTA sequences in displaying relationship of trigeminal nerve and vascular was 97.22％ (35/36),97.06％ (33/34),100％ (2/2),100％ (33/33)and 66.67％ (2/3),respectively,of relationship between facial nerve and vascular was 93.55％ (29/31),96.55％ (28/29),50.00％ (1/2),96.55％ (28/29) and 50.00％ (1/2),respectively.Conclusion 3D-TOF and 3D-FIESTA sequences can clearly display the spatial relationship of nerve and adjacent vessels,therefore providing imaging evidences for MVD.

Value of MR diffusion tensor imaging in the assessment of the changes of trigeminal nerve and its correlation with the degree of vascular compression / 中华放射学杂志

Objective To investigate the value of MR diffusion tensor imaging(DTI)in assessment of the microstructural changes of the trigeminal nerve,and analyze it's correlation with the degree of vascular compression. Methods Thirty-four patients with trigeminal neuralgia from November 2015 to April 2017 were retrospectively analyzed in this study.And they were treated by microvascular decompression(MVD). There were 11 cases of gradeⅠ,16 cases of gradeⅡand 7 cases of gradeⅢaccording to the severity of the contact between nerves and vessels during the operation. All of them were scanned with three dimensional time-of-flight(3D-TOF)sequences, three dimensional fast imaging employing steady state acquisition(3D-FIESTA)sequences and DTI before undergoing surgical decompression. According to the preoperative MR scans,the trigeminal nerves were divided into the healthy side without neurovascular contact (25 cases) and the healthy side with a neurovascular contact (9 cases).The DTI parameters of the trigeminal nerve,including the anisotropic fraction(FA)and the ADC values were obtained.Comparison of the FA and ADC values of the trigeminal nerve between the different stages of the affected side was performed with single factor analysis of variance, and the paired samples t test was used to compare the difference of FA and ADC values of bilateral trigeminal nerve. The difference of FA and ADC values between the asymptomatic side with or without vascular contact was compared with independent sample t test. Spearman correlation analysis was used to evaluate the correlation between DTI parameters and the degree of compression. Results The FA values of patients with grades Ⅰ,ⅡandⅢwere 0.311±0.009, 0.308±0.007 and 0.299±0.009 respectively,and there was significant difference among different levels(F=5.269,P<0.05).The ADC values of the three grades were(2.298 ± 0.309)×10-3,(2.214 ± 0.175)×10-3and (2.259 ± 0.248)×10-3mm2/s respectively, showing no statistically significant difference(F=0.402,P>0.05). The FA values of bilateral trigeminal nerves in healthy side without neurovascular contact and in healthy side with neurovascular contact were statistically significant (t=-32.528,-25.178,P<0.05). There was significant difference in the ADC value of bilateral trigeminal nerves in the group without neurovascular contact(t=2.162,P<0.05).There was no statistically significant difference in the ADC values of bilateral trigeminal nerves in the healthy side of the neurovascular contact group(P>0.05).There were no statistically significant differences in the FA and ADC values between the two groups on the healthy side of the trigeminal nerve(P>0.05).The FA value was negatively correlated with the degree of vascular compression (r=-0.453,P<0.05),while the ADC value was not correlated with the degree of vascular compression(P>0.05). Conclusion DTI imaging can be used to evaluate the degree of trigeminal nerve injury. More obvious vascular compression leads to lower FA value.

Dynamic contrast-enhanced MRI and diffusion weighted imaging in evaluating the early response to chemotherapy in non-small cell lung cancer / 中华放射学杂志

Objective To investigate the value of dynamic contrast-enhanced(DCE)-MRI and DWI for the early assessment of curative effects in NSCLC. Methods Forty patients from September 2012 to September 2014 with NSCLC proven by pathology were examined with DCE-MRI and DWI, at one week before the first chemotherapy and one month after treatment. DCE parameters (MER, slope, WR) and ADC values of the tumors were calculated on the workstation. According to the changes of the tumor-size after treatment, all patients were divided into two groups: good response group and poor response group. Pretreatment parameters were compared between the two groups with independent-samples t test, and parameter changes before and after treatment were compared with paired-samples t Test. ROC curve of tumor response characteristic was analyzed. Pearson correlation coefficient was used to study the correlation between post-treatment parameter changes and tumor size reduction. Results Pretreatment ADC, MER and slope value were (1.15 ± 0.09) × 10-3 mm2/s, 1.13 ± 0.28, (3.76 ± 1.27)% in the good response group(15 patients), and were (1.34±0.33)×10-3mm2/s, 0.78±0.16, (2.63±0.58)%in poor response group(25 patients), respectively. There was significant difference between tumors in two groups(t=2.329, 3.152, 4.556,P=0.027, 0.032, 0.009), the lower ADC value and the higher MER/slope value was observed in the good response group. The change rates of ADC after one month treatment in the two groups were (20.43±6.40)%, (2.98±1.65)%(t=3.485,P=0.009), and slope change were (-61.80±19.21)%, (-30.80±11.16)%(t=3.280, P=0.020). Both the rising rate of ADC and decreasing rate of slope value were significant higher in good response group than the poor response group. The ROC curve was used to analyze the change rate of ADC and slope after tumors treatment, the area under the ROC curve in ADC was largest(Az=0.790), the diagnosis efficiency was highest. We found significant positive correlation between ADC, MER, slope change rate and tumor maximum diameter reduction rate after chemotherapy(r=0.637, 0.396, 0.532,P<0.05). Conclusions DCE parameters and ADC values possess important clinical value to evaluate the early effect of chemotherapy in NSCLC. ADC value is more sensitive to early lung cancer response.