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Objective:To investigate the diagnostic value of three-dimensional amide proton transfer-weighted imaging (APTWI) and its combination with diffusion weighted imaging (DWI) for differentiating breast benign from malignant lesions.Methods:This was a prospective study. From July to December 2020, 226 patients with breast lesions confirmed by surgery or puncture pathology in the First Affiliated Hospital of Zhengzhou University were collected. All patients underwent MR T 1-weighted imaging, T 2-weighted imaging, DWI, APTWI, and dynamic contrast-enhanced MRI, and the apparent diffusion coefficient (ADC) value and the magnetization transfer ratio asymmetry at an offset of 3.5 ppm [MTRasym(3.5 ppm)] were obtained from DWI and APTWI respectively. Mann-Whitney U test was used for the comparison of DWI and APTWI parameters between breast benign and malignant lesions. Receiver operating characteristic (ROC) curve was used to evaluate the differences of diagnostic efficacy between DWI, APTWI, and their combination. Results:There were 226 patients with 226 breast lesions, including 124 malignant and 102 benign lesions. The ADC values of patients with malignant breast lesions [1.03 (0.93, 1.13)×10 -3 mm 2/s] and MTRasym (3.5 ppm) [1.95% (1.10%, 2.88%)] were lower than those of benign breast lesions [1.38 (1.11, 1.55)×10 -3 mm 2/s, 3.30% (2.20%, 4.20%), respectively], and the differences were statistically significant ( Z=-8.19, -6.51, P<0.05). The area under the ROC curves (AUC) of DWI, APTWI, and its combination in the differential diagnosis of benign and malignant breast lesions were 0.817, 0.752, and 0.868, respectively. The AUC of the combination of DWI and APTWI was higher than that of DWI and APTWI ( Z=4.00, 2.93, P<0.05), and there was no significant difference in the AUC between DWI and APTWI diagnoses ( Z=1.58, P>0.05). Taking 1.25×10 -3 mm 2/s as the optimal cut-off value for ADC values, the sensitivity, specificity, and accuracy in differentiating benign from malignant breast lesions were 94.4% (117/124), 62.7% (64/102), and 80.1% (181/226), respectively; Taking 2.70% as the optimal cut-off value for MTRasym (3.5 ppm), the sensitivity, specificity, and accuracy in differentiating benign from malignant breast lesions were 73.4% (91/124), 64.7% (66/102), and 69.5% (157/226), respectively, and the sensitivity, specificity, and accuracy of DWI combined with APTWI in differentiating benign from malignant breast lesions were 82.3% (102/124), 79.4% (81/102), and 81.0% (183/226), respectively. Conclusion:APTWI can be used for the differential diagnosis of benign and malignant breast lesions, and the combination of APTWI and DWI can obtain the better diagnostic performance than the single method.
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Objective To study the high-field MRI findings of gastrointestinal stromal tumors(GIST), investigate the diagnostic value of the tumor.Methods The image findings and clinical date of 45 cases with GIST proved by pathology were analyzed retrospectively.Results In 45 cases of GIST,tumors were located in the sacroanterior 2 cases, in the perineum 5 cases, in the small bowel 5 cases, in the rectum 10 cases and in the stomach 23 cases.Of 45 cases, there were 11 cases of recurrence,and 34 cases of new-onset.High-field MRI showed the tumors with inhomogeneous signal intensity, the small lesions with even homogeneous signals, the larger with non-uniform signalwhich may be cystic degeneration, necrosis, hemorrhage.After enhanced scan,the solid part of the tumor were abnormal enhancement,necrosis andcystic degeneration no enhancement.Clear or not clear of tumor boundaries andadjacent tissue pressure were prone to metastasis or intraperitoneal planting.Pathology results showed: the tumors cut surface was gray, gray-red, visible envelope.The microscopic morphology was varied, ranging from the number of spindle cells.Immunohistochemical findings were as following: CD34(+) in 43 cases;CD117(+) in 40 cases;Desmin(+) in 18 cases;Vimentin(+) in 15 cases.Conclusion High-field MRI can accurately position gastrointestinal stromal tumor, and has great value for its diagnosis and differential diagnosis.
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Objective To investgate the value of various parameters obtained from monoexponential, biexponential, and stretched exponential diffusion?weighted imaging models in the differential diagnosis of breast lesions. Methods A retrospective study performed in 54 patients with pathologically confirmed malignant tumors(n=30), benign lesions(n=34) and normal fibroglandular tissues (n=30). All patients underwent T1WI, T2WI, dynamic enhancement and diffusion weighted MRI with multi?b values at a 3.0 T magnetic resonance imaging unit. All parameters were measured at a workstation. ADC was calculated by using monoexponential analysis(b=0, 800 s/mm2). Slow apparent diffusion coefficient (ADC?slow), fast apparent diffusion coefficient (ADC?fast), and perfusion fraction (f) were calculated using the biexponential model. Distributed diffusion coefficient (DDC) and water molecular diffusion heterogeneity index (α) were obtained from diffusion?weighted images using the stretched exponential model. All parameters were statistically compared among normal fibroglandular tissues, benign lesions and malignant tumors using Kruskal?Wallis rank sum test. Mann?Whitney U test were used for further comparisons between specific group pairs. ADC values were compared with ADC?slow and DDC for different groups by paired Wilcoxon test. Correlations between ADC?value, ADC?slow and DDC were assessed by using Spearman rank correlation coefficient. Receiver operating characteristic curve was used to analyze and compare the ability of these parameters in differentiation of benign and malignant breast lesions. Results The ADC, ADC?slow, f, DDC and α values were significantly different among the normal fibroglandular tissues, benign tumors and malignant tumors (P<0.05). Further differential comparisons of the four parameters between each pair showed that the ADC, ADC?slow, f, DDC and α values were significantly lower in malignant tumors than both in normal fibroglandular tissues and benign tumors(P<0.016 7). The ADC values of normal fibroglandular tissues, benign tumors and malignant tumors were significantly higher than ADC?slow and DDC (P<0.05). The f and DDC had higher area under the receiver operating characteristic curve (0.688 and 0.657 respectively). The optimal cutoff values for ADC, ADC?slow, f, DDC and α were 1.235 × 10-3mm2/s, 0.428 × 10-3mm2/s, 57.8%, 1.175 × 10-3mm2/s and 0.721, respectively. Theαvalue showed higher specificity (65.5%) and the f value had higher sensitivity (82.9%). Conclusion The parameters derived from biexponential and stretched exponential DWI could be helpful for differentiation between benign and malignant breast tumors.
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Aiming at status of training the rural order directed free medical educational talents, we should improve the understanding of training the free medical students, perfect the relevant management system, strengthen medical ethics education of students, pay attention to humanistic care of students,strengthen the continuing education of students, standardize the access system of students, reform the medical distribution system, to ensure the quality of training free medical students.