RESUMO
OBJECTIVES: We propose an automatic breast mass detection algorithm in three-dimensional (3D) ultrasound (US) images using the Hough transform technique. METHODS: One hundred twenty-five cropped images containing 68 benign and 60 malignant masses are acquired with clinical diagnosis by an experienced radiologist. The 3D US images are masked, subsampled, contrast-adjusted, and median-filtered as preprocessing steps before the Hough transform is used. Thereafter, we perform 3D Hough transform to detect spherical hyperplanes in 3D US breast image volumes, generate Hough spheres, and sort them in the order of votes. In order to reduce the number of the false positives in the breast mass detection algorithm, the Hough sphere with a mean or grey level value of the centroid higher than the mean of the 3D US image is excluded, and the remaining Hough sphere is converted into a circumscribing parallelepiped cube as breast mass lesion candidates. Finally, we examine whether or not the generated Hough cubes were overlapping each other geometrically, and the resulting Hough cubes are suggested as detected breast mass candidates. RESULTS: An automatic breast mass detection algorithm is applied with mass detection sensitivity of 96.1% at 0.84 false positives per case, quite comparable to the results in previous research, and we note that in the case of malignant breast mass detection, every malignant mass is detected with false positives per case at a rate of 0.62. CONCLUSIONS: The breast mass detection efficiency of our algorithm is assessed by performing a ROC analysis.
Assuntos
Neoplasias da Mama , Mama , Diagnóstico , Diagnóstico por Computador , Detecção Precoce de Câncer , Processamento de Imagem Assistida por Computador , Máscaras , Curva ROC , UltrassonografiaRESUMO
OBJECTIVE: To evaluate the clinical factors that contribute to femoral neuropathy subsequent to abdominal hysterectomy. METHODS: From March 1993 to March 2000, retrospective study on 17 cases of femoral neuropathy subsequent to abdominal hysterectomy was performed. Sixty eight patients who had normal neurologic finding on the lower extremities after the same operation were used as a control group. RESULTS: The incidence of femoral neuropathy subsequent to abdominal hysterectomy was 1.67%. Age, body weight, parity and type of skin incision were significantly different between study and control group. The mean age of the study group was 38.1+6.1 years and that of the control group was 43.2+/-8.9 years(p<0.05). The mean body weight of the study group was 52.9 6.4kg, while that of the control group was 57.8+/-7.4kg(p<0.05). The mean parity of the study group was 1.9+/-0.7 as opposed to 2.6+/-1.3 for the control group(p<0.05). Pfannenstiel`s incision was performed in 13 cases(76.5%) in the study group as opposed to 34 cases(50%) in the control group(p<0.05). There were no correlation between these two groups with respect to patient height, operative time, transfusion and change in hemoglobin level. In the study group, 13 cases(76.5%) with femoral neuropathy on the left side were found, 3 cases(17.6%) on the right side and 1 case(5.9%) on both side. Left side femoral neuropathy was more common than the right(p<0.05). Spontaneous recovery occurred in 16 cases of the study group within 4 months and, although residual symptoms were noted in the remaining 1 case, no serious sequelae have been observed. CONCLUSION: It was suggested that pelvic retractor compresses the femoral nerve during the abdominal hysterectomy. The patients age, body weight, parity and a type of skin incision could be contributing factors to femoral neuropathy.