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Objective:To investigate the value of CT-radiomics based machine learning model in predicting the abundance of tumor infiltrating CD8 +T cells and the prognosis of pancreatic cancer patients. Methods:A total of 150 pancreatic cancer patients who underwent surgical excision and confirmed by pathology from Fudan University Shanghai Cancer Center between December 2011 and January 2017 were retrospectively enrolled. The patients were randomly divided into the training set ( n=105) and the validation set ( n=45) in a 7∶3 ratio with simple random sampling. The immunohistochemical method was used to assess the abundance of tumor infiltrating CD8 +T cells, and the patients were then divided into high infiltrating group ( n=75) and low infiltrating group ( n=75) according to the median. The prognosis between the 2 groups was evaluated using Kaplan-Meier method and log-rank test. Radiomic features were extracted from preoperative venous-phase enhanced CT images in the training set. The Wilcoxon test, the max-relevance and min-redundancy algorithm were used to select the optimal feature set. Three supervised machine learning models (decision tree, random forest and extra tree) were established based on the optimal feature set to predict the abundance of tumor infiltrating CD8 +T cells. Performance of above-mentioned models to predict the abundance of tumor infiltrating CD8 +T cells in pancreatic cancer was tested in the validation set. The evaluation parameters included area under the receiver operating characteristic curve (AUC), F1-score, accuracy, precision and recall. Results:The median overall survival time of patients in high infiltrating group and low infiltrating group were 875 days and 529 days, respectively (χ2=11.53, P<0.001). The optimal feature set consisted of 10 radiomic features in training set. In the validation set, the decision tree, random forest and extra tree model showed the AUC of 0.620, 0.704 and 0.745, respectively; corresponding to a F1-score of 0.457, 0.667 and 0.744, the accuracy of 57.8%, 68.9% and 75.6%, the precision of 66.7%, 73.7% and 80.0%, the recall of 34.8%, 60.9% and 69.6%. Conclusions:Pancreatic cancer patients with high tumor infiltrating CD8 +T cells have better prognosis than those with low tumor infiltrating CD8 +T cells. The radiomics-based extra tree model is valuable in predicting the CD8 +T cells infiltrating level in pancreatic cancer.
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Objective:To evaluate the application values of small FOV surface coil and BLADE sequence in MR imaging on assessment of talar cartilage injury of ankle joint under traction.Methods:The clinical and imaging data of 53 patients with ankle cartilage injury in the Affiliated Suzhou Hospital of Nanjing Medical University from December 2018 to July 2020 were prospectively analyzed. All patients underwent the following MR sequences: sequence Ⅰ was fast spin echo proton density weighted (FSE-PD) BLADE sequence with surface coil small FOV, and sequence Ⅱ was FSE-PD-BLADE imaging of small FOV under horizontal load traction of ankle joint. Paired sample Wilcoxon rank sum test was used to compare the thickness of talus dome cartilage, cartilage space and subjective assessment score of image quality (including the outline of the upper surface of the cartilage at the injury, the thickness of the cartilage layer at the injury, the rupture of the cartilage at the injury, the relationship between cartilage and subchondral bone, subchondral bone collapse or trabecular fracture line) between sequence I and sequence Ⅱ.Results:There was significant difference in the thickness of central cartilage of talus between sequence Ⅰ and sequence Ⅱ [0.70 (0.60, 0.90) mm and 0.80 (0.70, 0.90) mm, Z=-2.900, P=0.004, respectively]. There was no significant difference in the thickness of medial and lateral talus cartilage between sequence Ⅰ and sequence Ⅱ (P>0.05). There were significant differences between sequence Ⅰ and sequence Ⅱ in the center [0.10 (0, 0.15), 0.89(0.63, 1.00) mm], medial [0.10(0, 0.31), 1.20(0.70, 1.25) mm] and lateral cartilage space [0.18(0.08, 0.23), 0.90(0.76, 0.94)mm] (all P<0.001). As for the subjective assessment score of talus cartilage injury, except for score in subchondral bone collapse or bone trabecular fracture line between sequence Ⅱ and sequence Ⅰ ( Z=-1.480, P=0.139), significant differences were found in all other scores ( P<0.05). Conclusion:MRI of the ankle under traction is safe and feasible. Under the condition of horizontal traction, small FOV surface coil combined with BLADE sequence can better display talus cartilage injury.
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Objective To investigate the influence of lengthening or tortuous basilar artery (BA) on the BA hemodynamic parameters measured by transcranial doppler (TCD).Methods 153 cases with CTA and TCD simultaneously evaluating the BA were included.According to CTA criterion,144 cases were with lengthening and/or tortuous BA and 9 cases were without lengthening and/or tortuous BA.The TCD cerebral hemodynamic parameters included peak systolic velocity (PSV),mean blood flow velocity (MFV),end diastolic velocity (EDV),pulsatility index (PI) and resistant index (RI).The relationship between the grading of lengthening/tortuous of BA and TCD parameters were analyzed.Results ①The TCD parameters (PSV,MFV,EDV,PI,RI) showed no significant statistical differences among the grades of lengthening BA.The correlation between the TCD paremeters (PSV,MFV,EDV,PI,RI) and the grades of lengthening BA showed no significant statistical differences.②The TCD parameters (PSV,MFV,PI,RI) showed significant statistical differences among the grades of tortuous BA.The TCD parameters (PSV,MFV,PI,RI) showed significant statistical differences between grade 0 and grade 3 of tortuous BA.The significant negative correlation between the TCD parameters (PSV,MFV,EDV,PI,RI) and the grades of tortuous BA was found.Conclusion The tortuosity of BA can lead to hemodynamic alterations,whereas the lengthening of BA does not affect cerebral hemodynamics significantly.
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Objective To investigate the relationships of MR indexes such as acromio humeral intervals (AHI),lateral extension of the acromion (LEA) and inclination angle of the acromion with the subacromial impingement syndrome (SIS).Methods 151 patients underwent MRI examination of shoulder joints,they were grouped according to age,gender and location of acromion.The differences in age,gender and MR indexes were compared between SIS group and non SIS group.The distribution statuses of SIS in different groups were compared at the same time,the relationships of various MR indexes with SIS were investigated and analyzed.Results There were no statistical differences in age,location distribution,the average shortest AHI value and the thickness of the subacromial bursal effusion between SIS group and non SIS group (P ＞ 0.05).There showed statistical difference in gender between the two groups (P =0.000),and there were more males than females in both groups.The acromion exactly covered the supraspinatus tendon in 79 patients,the average value of LEA in the SIS group was greater than that in the non SIS group,and there showed statistically significant difference between the two groups (P =0.002),the Youden index of LEA was 0.40,the sensitivity was 61％ and the specificity was 79％.The inclination angle of the acromion in the SIS group was smaller than that in the non SIS group,and there was a statistically significant difference between the two groups (P =0.019),the Youden index of the inclination angle of the acromion was 0.18,the sensitivity was 62％ and the specificity was 56％.47 patients in the SIS group had subacromial bursal effusion,51 patients in the non SIS group had subacromial bursal effusion.The thickness of the subacromial bursal effusion in the SIS group was greater than the non SIS group,and there showed statistically significant difference between the two groups (P =0.002),the Youden index of the thickness of the subacromial bursal effusion was 0.34,the sensitivity was 78 ％ and the specificity was 56 ％.Conclusion LEA,the inclination angle of the acromion and the thickness of the subacromial bursal effusion can be used as quantitative MR diagnostic criteria of SIS.The LEA measured by cardiothoracic ratio is simple and easy to use.
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Objective To investigate the value of fused 3D-SPACE and 3D-TOF images in diagnosis of intracranial neurovascular compression syndrome.Methods 26 patients with intracranial neurovascular compression syndrome were examined using 3D-SPACE sequence and 3D-TOF sequence.After 3D-SPACE and 3D-TOF were fused by different times,the quality of image as well as the ability of j udging the relationship between nerves and blood vessels was analyzed and compared between the original images and the fused images.Results In this study,the fused images by adding one 3D-SPACE sequence and one 3D-TOF sequence showed the highest accurate than others(2 1 cases),and the j udgement of the relationship between the responsible blood vessels and nerve accor-ded with the surgical results to the highest extent (P<0.05).Conclusion The fusion image of 3D-SPACE sequence and 3D-TOF se-quence can improve the diagnostic ability of the intracranial neurovascular compression syndrome,and the appropriate proportion of the fusion image can show the relationship between the nerve and blood vessel.
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Objective To compare the accuracy rate of talar osteochondral lesions between the small field of view (FOV) surface coil MR imaging and 2D FSE proton density weighted imaging (2D-FSE-PD),3D-SPACE sequences MR imaging with boot-shaped coil.Methods Totally 43 patients (45 ankles) underwent 3D-SPACE sequence after 2D-FSE-PD sequence scanning using the boot-shaped coil,then the PDWI sequence was scanning after the boot-shaped coil was replaced by the small FOV surface coil at 1.5T MRI.The results of the arthroscopic examinations was regarded as the standard for assessing the accuracy rate of the three methods.Results The accuracy rate of 2D-FSE-PD sequence with small FOV surface coil was 86.67％ (39/45),the accuracy rate of 2D-FSE-PD sequence with boot coil was 60.00％ (27/45),the accuracy rate of 3D-SPACE sequence with boot coil was 68.89％ (31/45).The accuracy rate of small FOV surface coil was higher than those of boot coil used 3D-SPACE sequence (x2 =4.114,P =0.002) and boot coil used 2D-FSE-PD sequence (x2 =8.182,P＜0.001).There was not significant difference between 3D-SPACE sequence using boot coil and 2D-FSE-PD sequence using boot coil (x2 =0.776,P=0.125).Conclusion Compared with the 2D-FSE-PD and 3D-SPACE sequences with boot-shaped coil,the small surface coil scanning with routine sequence can show talar osteochondral lesions better.
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Objective To compare the imaging quality of articular cartilage of the knee with 3D-sampling perfection with applica-tion optimized contrast using different flip angle evolutions (3D-SPACE),3D-true fast imaging with steady-state precession (3D-True FISP)and 2D-fast-spin-echo-proto-density(2D-FSE-PD)sequences.Methods 40 healthy volunteers and 20 patients of knee joints were examined with 3D-SPACE,3D-True FISP and 2D-FSE-PD sequences at 1.5T MRI.Signal-noise ratio (SNR),contrast-to-noise ratio (CNR)and lesion visualization of articular cartilage were compared.Results 3D-SPACE showed the highest SNR of cartilage and CNR of fluid/cartilage among the three sequences (P <0.05).3D-SPACE had the better capability for showing the lev-el I 、level Ⅱcartilage injury comparing with 3D-True FISP,but no significant difference between the cartilage injury at level Ⅲ and level Ⅳ.For all levels of cartilage injury,3D sequence was better than the 2D sequence.Conclusion Compared with the 3D-True FISP sequence and 2D-FSE-PD sequence,3D-SPACE sequence can show the structure of knee and knee cartilage injury better.