Objective To evaluate the diagnostic value of computed tomographic(CT) guided percutaneous fine-needle aspiration biopsy(FANB) in mediastinal lesions.Methods The authors retrospectively reviewed the records of 104 patients of the mediastinal lesions who underwent CT guided percutaneous fine-needle aspiration biopsy.The sites of CT guided biopsy in 104 patients included anterior mediastinum(n = 73) ,middle mediastinum(n = 29) and posterior mediastinum(n = 2) .The mediastinal lesions with variation in size from 2.31 cm ? 1.11 cm ～ 14.5 cm ? 10.3 cm(

Objective To investigate nontraumatic avascular necrotic of the femoral head with different etiology whether or not having similar MRI and pathologic findings.Methods MRI features of nontraumatic avascular necrosis of the femoral head caused by differant etiology in 98 patients(152 hips) were retrospectively analysed.The causes of osteonecrosis of the femoral head included steroid-induced in 49 patients(86 hips),alcoholic in 18 patients(25 hips) and idiopathic cause in 31 patients(41hips).Gross section and pathologic examinations were performed on 34 femoral heads obtained after total hip replacement from 25 patients.Results Osteonecrosis of the femoral head with different etiology occurred at the anterior superior part of femoral head.The necrotic zones both on pathological gross section and MRI were consisted of cartilage,necrotic focus,proliferative zone and normal bony zones along the lesions.The proliferative zone surrounded necrotic area was low signal intensity on both T1WI and T2WI.There was correlations between localized MRI signal behavior and specific histopathologic features of femoral head osteonecrosis.Conclusion Nontraumatic osteonecrosis of the femoral heads associated with different etiology have similar characteristics on both MRI and pathology

Objeetive To evaluate imaging appearances of herniation pit of the femoral neck.Methods We retrospectively analyzed the X-ray,CT and MRI findings of 9 patients with herniation pit of the femoral neck.All nine patients were male with the age ranging from 21 to 73 years.They had pain in the hip from two months to two years duration.Results The bilateral hips were affected in six patients,the right hips in the other 3 patients.Of the nine patients,X-ray plain films(2 cases),CT scanning(6 cases),and MR scanning(5 cases)were performed.The size of the lesions ranged from 0.5 cm×0.6 cm to 1.0 cm×1.5 cm,located in the anterosuperior portion of the femoral neck(n=7)or anteroinferior portion(n=2).X-ray plain films showed an osteolytic lesion surrounded by a sclerotic rim.CT scanning showed the lesion just below the cortex of the femoral neck surrounded by a rim of sclerosis or associated with a small cortical break in two patients.MR scanning showed low signal intensity in five patients on T1WI and high signal intensity surrounded by a rim of low signal intensity(n=3)or low signal intensity(n=2)on T2WI,and high signal intensity on fat suppression MR image.A small joint effusion was observed in two cases on T2WI.Conclusion The CT and MRI findings of herniation pit of the femoral neck are characteristic,it is useful in defining the diagnosis of the herniation pit of the femoral neck.

Background and purpose:Axillary lymph node metastasis of breast cancer has an important significance in prognosis and treatment of breast cancer. This study was to investigate the correlation between axillary lymph node metastasis and ultrasonographic characteristics of axillary lymph node combined with immunohistochemistry in breast cancer patients.Methods:A total number of 366 breast cancer patients were selected in this study. Seven hundred and twenty-eight axillary lymph nodes were collected. With ultrasonography, the maximum cortex thickness, the ratio of the height to the length, the ratio of the cortex to the medulla and blood lfow of axillary lymph nodes were observed, in order to study the correlation between these indicators and axillary lymph node metastasis combined with the postoperative immunohistochemical results.Results:According to univariate analysis, axillary lymph node maximum cortex thickness, the ratio of the height to the length, characteristics of blood flow and the positive expression rate of p53 were related to axillary lymph node metastasis (P<0.05). Multivariate logistic regression analysis and receiver operating characteristic (ROC) curve showed that axillary lymph node maximum cortex thickness was the best indicator to determine axillary lymph node metastasis. The positive expression rate of p53 in patients with maximum cortex thickness >3 mm (42.78%) of axillary lymph node was signiifcantly higher than that in patients with maximum cortex thickness≤3 mm (25.82%) (P<0.01).Conclusion:Ultrasonographic characteristics of axillary lymph node and immunohistochemistry method are closely correlated with axillary lymph node metastasis in patients with breast cancer, which is important in diagnostic and treatment in clinic.

The monitoring unit used in the nuclear magnetic resonance system,as an important unit of the system,faces a high thermal risk during its entire life cycle.This paper ensures the high efficiency and reliability of the thermal design of the product module from the two dimensions of structural design and device derating design.In order to reduce the risk of thermal design of electronic modules and comprehensively verify the effectiveness of thermal design of electronic modules,the design verification is carried out by combining simulation and experiment.In the simulation process,by establishing a thermal simulation model at the circuit board level,the crustal temperature of the core device is numerically calculated,and the index is compared with the thermal design index value and the test value,on the one hand,to verify the correctness of the simulation model.On the other hand,the validity of thermal design is verified.In the testing process,a thermal test platform for product modules is built,and the thermal characteristics test values of the core components of the module under extreme electrical conditions are obtained,and the corresponding conversion methods are used to predict the thermal performance and thermal design margin of the product at different altitudes.The results show that the electronic module can meet the thermal design requirements in terms of structural design and derating design of core components,and can ensure that the product module can work safely and reliably during the entire life cycle of the NMR system.