Objective To determine feasibility of texture analysis of non-enhanced CT scan for differential diagnosis of liver cancer and hepatic hemangioma. Methods Fifty-six patients with liver cancer or hepatic hemangioma confirmed by pathology were enrolled in this retrospective study. After exclusion of images of 4 patients with artifacts and lesion diameter less than 1.0 cm, images of 52 patients (57 lesions) were available to further analyze. Texture features derived from the gray-level histogram, co-occurrence and run-length matrix, absolute gradient, autoregressive model, and wavelet transform were calculated. Fisher, probability of classification error and average correlation (POE+ACC), and mutual information coefficients (MI) were used to extract 10 optimized texture features. The texture characteristics were analyzed by using linear discriminant analysis (LDA) and nonlinear discriminant analysis (NDA) provided by B11 module in the Mazda software, the minimum error probability of differential diagnosis of liver cancer and hepatic hemangioma was calculated. Most discriminating features (MDF) of LDA was applied to K nearest neighbor classification (KNN); NDA to extract the data used in artificial neural network (ANN) for differential diagnosis. Results The NDA/ANN-POE+ACC was the best for identifying liver cancer and hepatic hemangioma, and the minimum error probability was the lowest as compared with the LDA/KNN-Fisher, LDA/KNN-POE+ACC, LDA/KNN-MI, NDA/ANN-Fisher, and NDA/ANN-MI respectively, the differences were statistically significant (χ2=4.56, 4.26, 3.14, 3.14, 3.33;P=0.020, 0.018, 0.026, 0.026, 0.022). Conclusions The minimum error probability is low for different texture feature selection methods and different analysis methods of Mazda texture analysis software in identifying liver cancer and hepatic hemangioma, and NDA/ANN-POE+ACC method is best. So it is feasible to use texture analysis of non-enhanced CT images to identify liver cancer and hepatic hemangioma.
This study aims to analyze the biomechanical stability of Magic screw in the treatment of acetabular posterior column fractures by finite element analysis. A three-dimensional finite element model of the pelvis was established based on the computed tomography (CT) and magnetic resonance imaging (MRI) data of a volunteer and its effectiveness was verified. Then, the posterior column fracture model of the acetabulum was generated. The biomechanical stability of the four internal fixation models was compared. The 500 N force was applied to the upper surface of the sacrum to simulate human gravity. The maximum implant stresses of retrograde screw fixation, single-plate fixation, double-plate fixation and Magic screw fixation model in standing and sitting position were as follows: 114.10, 113.40 MPa; 58.93, 55.72 MPa; 58.76, 47.47 MPa; and 24.36, 27.50 MPa, respectively. The maximum stresses at the fracture end were as follows: 72.71, 70.51 MPa; 48.18, 22.80 MPa; 52.38, 27.14 MPa; and 34.05, 30.78 MPa, respectively. The fracture end displacement of the retrograde tension screw fixation model was the largest in both states, and the Magic screw had the smallest displacement variation in the standing state, but it was significantly higher than the two plate fixations in the sitting state. Magic screw can satisfy the biomechanical stability of posterior column fracture. Compared with traditional fixations, Magic screw has the advantages of more uniform stress distribution and less stress, and should be recommended.
Objective To analyze the characteristics of femoral neck fractures in young and middle-aged adults by means of medical image analysis and fracture mapping technology to provide reference for fracture treatment. Methods A clinical data of 159 young and middle-aged patients with femoral neck fractures who were admitted between December 2018 and July 2019 was analyzed. Among them, 99 patients were male and 60 were female. The age ranged from 18 to 60 years, with an average age of 47.9 years. There were 77 cases of left femoral neck fractures and 82 cases of right sides. Based on preoperative X-ray film and CT, the fracture morphology was observed and classified according to the Garden classification standard and Pauwels’ angle, respectively. Mimics19.0 software was used to reconstruct the three-dimensional models of femoral neck fracture, measure the angle between the fracture plane and the sagittal plane of the human body, and observe whether there was any defect at the fracture end and its position on the fracture surface. Through reconstruction, virtual reduction, and image overlay, the fracture map was established to observe the fracture line and distribution. Results According to Garden classification standard, there were 6 cases of type Ⅰ, 61 cases of type Ⅱ, 54 cases of type Ⅲ, and 38 cases of type Ⅳ. According to the Pauwels’ angle, there were 12 cases of abduction type, 78 cases of intermediate type, and 69 cases of adduction type. The angle between fracture plane and sagittal plane of the human body ranged from –39° to +30°. Most of them were Garden type Ⅱ, Ⅳ and Pauwels intermediate type. The fracture blocks were mainly in the form of a triangle with a long base and mainly distributed below the femoral head and neck junction area. Twenty-six cases (16.35%) were complicated with bone defects, which were mostly found in Garden type Ⅲ, Ⅳ, and Pauwels intermediate type, located at the back of femoral neck and mostly involved 2-4 quadrants. The fracture map showed that the fracture line of the femoral neck was distributed annularly along the femoral head and neck junction. The fracture line was dense above the femoral neck and scattered below, involving the femoral calcar. Conclusion The proportion of displaced fractures (Garden type Ⅲ, Ⅳ) and unstable fractures (Pauwels intermediate type, adduction type) is high in femoral neck fractures in young and middle-aged adults, and comminuted fractures and bone defects further increase the difficulty of treatment. In clinical practice, it is necessary to choose treatment plan according to fracture characteristics. Anatomic reduction and effective fixation are the primary principles for the treatment of femoral neck fracture in young and middle-aged adults.
Carney triad is a rare tumor syndrome with few reports. This case showed the enhanced CT and MRI images of a rare young woman patient with Carney triad (containing gastric stromal tumor, renal cell carcinoma, adrenal pheochromocytoma, and pulmonary chondrosarcoma), which is intended to provide a reference for clinical diagnosis and differential diagnosis. This case reminds the radiologists and clinicians that the patients with a history of primary gastrointestinal stromal tumor and neoplastic lesions occurring at specific sites (pulmonary chondrosarcoma, adrenal pheochromocytoma, renal cell carcinoma, etc.) need to be alerted to the possibility of combining with Carney triad.