Objective To investigate the application value of DWI based on biexponential signal decay model with extended b-fac-tor range in differential diagnosis of benign and malignant breast lesions.Methods A total of 57 patients with breast tumor under-went DWI based on the biexponential model with 12 b-factors (0,10,20,50,100,200,400,600,800,1000,1 200 and 1 500 s/mm2 ), including benign lesions in 1 9 patients (24 breast tumors,defined as benign group)and malignant ones in 38 (47 tumors,defined as malignant group ).The values of slow apparent diffusion coefficient,fast apparent diffusion coefficient and fraction of fast ADC of le-sions were measured at a workstation (Advantage Windows 4.5).Differences in these parameters between the benign and malignant groups were compared.Results The ADCslow,ADCfast and ffast were(1.434±0.291)×10 -3 mm2/s,(2.744±0.050)×10 -3 mm2/s and (0.677±0.130)% in benign group,and (0.614±0.196)×10 -3 mm2/s,(2.692±0.068)×10 -3 mm2/s and (0.446±0.112)% in malig-nant one,respectively.The statistical differences in ADCslow and ffast were found between two groups (P <0.05),whereas no difference in ADCfast was found.Conclusion Biexponential signal decay model of DWI with extended b-factor range can provide helpful tissue characterization parameters for the differential diagnosis of benign and malignant breast lesions.

Objective To compare and analyze the index variation of Yang deficiency mice induced by hydrocortisone in different way of administration and dose. Methods The mice model of Yang deficiency were induced by low dose and high dose hydrocortisone(12.5 mg/kg, 25 mg/kg) in two ways of intramuscular and intraperitoneal injection. The symptoms, body weight, the average intake, the index of stress and the coefficient of sex organs and immune organs of animals were observed. Results In the way of intraperitoneal injection, the weight(24.52±3.29)g, body temperature(35.24±0.32)℃ of high dose of model group were significantly lower than that of control group(31.10±6.11)g,(37.02±0.64)℃. The average intake of low dose group(4.30 ± 0.29)g/(per?d) was lower than control group(7.38±0.53)g/(per?d), and the coefficient of preputial glands(0.10±0.02), penis(0.15±0.03), thymus(0.12±0.03)were lower than that of control group. In the way of intramuscular injection, the average intake of high dose group(5.92±2.01)g/(per?d) was lower than control group(8.60±1.33)g/(per?d). The body temperature(34.90±0.22)℃ and the time of swimming in low temperature (34.00±22.41)s of low dose model group were lower than that of control group(36.43±0.91)℃, (67.17±21.93)s, and the coefficient of thymus of two model groups(0.10±0.02),(0.11±0.06)were lower than that of control group. Conclusion Various dose and model establishment methods of Yang deficiency mice have different the time of symptom appearing, the degree of symptom and sensitive index.

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.

Objective To investigate the value of qualitative and quantitative parameters of MRI on diagnosis of benign and malig-nant breast lesions.Methods Patients were scanned with MRI who were confirmed as breast lesions verified by histopathology,and the time-signal curve(TIC),Slopemax ,the apparent diffusion coefficient values (ADC)were deduced.Results There were 24 benign and 11 malignant lesions.Features of benign lesions were shown as follow:The TIC type wasⅠmostly 91.7%,Slopemax was 0.65 %/s,the ADC values was 1.31×10 -3 mm2/s.Features of malignant lesions were shown as follow:The TIC type were Ⅱ and Ⅲ mostly (100%), Slopemax was 1.63 %/s,the ADC values was 1.06 ×10 -3 mm2/s.Conclusion Types of TIC,Slopemax ,the ADC values of MRI are valuable in the diagnosis of benign and malignant breast lesions,integrated functional parameters are better than an individual param-eters in that they can improve the accuracy of diagnosis.

Objective To analyze MRI features of invasive cribriform carcinoma of the breast,and to improve the diagnostic accuracy of the disease.Methods MRI of 10 cases with biopsy-proved invasive cribriform carcinoma of the breast in our hospital were analyzed retrospectively.Results 10 cases with invasive cribriform carcinoma of the breast showed unclear boundary.Lesions showed isointensity on T1 WI,and hyperintensity on T2 WI partially with point-like low signal intensity.After contrast administration,the lesions showed heterogeneous enhancement,most of which showed point-like low signal intensity in the lesions,which may be the characteristic manifestations of invasive cribriform carcinoma of the breast.The patterns of time-signal intensity curves were washout type and platform type.Five cases had lymph node metastasis,which may due to the overexpression of PR.Conclusion MRI plays an important role in the diagnosis of invasive cribriform carcinoma of the breast.There is a promising benefit of this radiation-free technique for selecting the optimal therapeutic regimen for this disease.

Objective To observe the value of zero echo time(ZTE)3.0T MRI for detecting lung cancer nodules.Methods Totally 126 lung cancer patients(176 lung nodules)were prospectively enrolled and underwent 3.0T MR axial lung scanning,including T1-volumetric interpolated breath-hold examination(VIBE),T2-BLADE,T2-half-Fourier acquisition single-shot turbo spin-echo(HASTE)and ZTE sequences.The consistency between ZTE MRI and previous CT for displaying characteristics of pulmonary nodules was analyzed,and the sensitivity of different MR sequences for detecting pulmonary nodules were observed.Results Among 176 pulmonary nodules showed on CT,ZTE MRI detected 140 and missed 36 ones.The consistency between ZTE MRI and CT for displaying the maximum diameter and actual maximum diameter of pulmonary nodules were both good(ICC=0.954,0.943,both P＜0.001),and the difference between ZTE MRI and CT was small.The consistency between ZTE MRI and CT for displaying tracheal vascular bundles,pleural indentation and internal bronchial inflation signs were all good(Kappa=0.894,0.912,0.917),while for displaying the type and shape of nodules were both moderate(Kappa=0.661,0.501).The sensitivity of ZTE MRI for detecting pulmonary nodules was higher than that of other individual MR sequences(all P＜0.05),of combination of ZTE and T2 BLADE was higher than that of other sequence combinations(all P＜0.05).Conclusion ZTE 3.0T MRI could be used to detect lung cancer nodules,which was superior to conventional MRI.Combination of ZTE 3.0T MRI with T2-BLADE could improve the sensitivity for detecting pulmonary nodules.