PURPOSE: To evaluate the radiologic characteristics of axillary lymph nodes which are found on mediolateral oblique(MLO) view of mammography and to assess their clinical significance. MATERIALS AND METHODS: We retrospectively evaluated 119 cases axillary lymph nodes on MLO view of 410 cases of mammography in 205 patients regarding the size, bilaterality, number, grade of density, presence of central lucency, calcification of lymph nodes and presence of associated parenchymal pathologic lesions in breast. RESULTS: Axillary lymph nodes on MLO view were demonstrated in 119 (29%) among 410 cases. Axillary lymph nodes(112 cases) in cases without breast parenchymal lesions or with benign breast lesions showed; unilaterality in 68 cases(61%), smaller than 1.5cm in 100 cases(89%), lower density than breast parenchyma in 99 cases(88%), presence of central lucency in 99 cases(88%) and calcification in 3 cases(2.7%). Axillary lymph nodes(7 cases)in cases with breast cancer showed small size of less than 1.5cm in 4 cases(57%), absence of central lucency in 7 cases(100%) and iso-to higher density than breast parenchyma in 7 c&ses(100%). CONCLUSION: Axillary lymph nodes noted on MLO view of mammography, more than 1.5cm in diameter, absence of central lucency and iso to higher density than breast parenchyma could be suggested as clinically significant.
Breast ; Breast Neoplasms ; Humans ; Lymph Nodes* ; Mammography ; Retrospective Studies

PURPOSE: To evaluate the radiologic characteristics of axillary lymph nodes which are found on mediolateral oblique(MLO) view of mammography and to assess their clinical significance. MATERIALS AND METHODS: We retrospectively evaluated 119 cases axillary lymph nodes on MLO view of 410 cases of mammography in 205 patients regarding the size, bilaterality, number, grade of density, presence of central lucency, calcification of lymph nodes and presence of associated parenchymal pathologic lesions in breast. RESULTS: Axillary lymph nodes on MLO view were demonstrated in 119 (29%) among 410 cases. Axillary lymph nodes(112 cases) in cases without breast parenchymal lesions or with benign breast lesions showed; unilaterality in 68 cases(61%), smaller than 1.5cm in 100 cases(89%), lower density than breast parenchyma in 99 cases(88%), presence of central lucency in 99 cases(88%) and calcification in 3 cases(2.7%). Axillary lymph nodes(7 cases)in cases with breast cancer showed small size of less than 1.5cm in 4 cases(57%), absence of central lucency in 7 cases(100%) and iso-to higher density than breast parenchyma in 7 c&ses(100%). CONCLUSION: Axillary lymph nodes noted on MLO view of mammography, more than 1.5cm in diameter, absence of central lucency and iso to higher density than breast parenchyma could be suggested as clinically significant.
Breast ; Breast Neoplasms ; Humans ; Lymph Nodes* ; Mammography ; Retrospective Studies

PURPOSE: Sometimes chronic subdural hematoma can be developed following posttraumatic subdural hygroma. The purpose of this study is to investigate its incidence, the duration required for their conversion, and characteristic CT and MR findings of subdural hygroma and chronic subdural hamatoma. MATERIALS AND METHODS: We studied 8 patients with persistent posttraumatic subdural hygroma which consquently developed chronic subdural hamatoma. The patients were examined with CT initially and foilowed-up with CT in 3 and MR in 5. We analyzed the location of the lesion, the change of the density or signal intensity, the change of the size, and the degree of enhancement and mass effect. RESULTS: The duration required for the formation of hematoma was 48-166 days (mean, 76 days). The characteristic CT findings of subdural hygroma were a crescentric lesion with CSF density along the inner table without contrast enhancement. The mass effect was minimal. The CT findings of chronic subdural hematoma were higher density than that of hygroma in all cases, increase in thickness and size in 3 cases, and contrast enhancement along the inner membrane of the hematoma in 5 cases. The signal intensities of the subdural hygroma were identical to those of CSF on both T1 and T2 weighted images, whereas, those of chronic subdural hematoma were higher. CONCLUSION: The increased signal intensity on T1 weighted MR images and increased attenuation or contrast enhancement of the lesion on CT may suggest the conversion of subdural hygroma into chronic subdural hematoma.
Hematoma ; Hematoma, Subdural, Chronic* ; Humans ; Incidence ; Lymphangioma, Cystic ; Membranes ; Subdural Effusion*

PURPOSE: Authors studied the injection method of contrast medium in routine chest spiral CT scan to obtain the best image in the mediastinum. MATERIALS AND METHODS: Dynamic static scan had been performed in 5 normal volunteers as a pilot study. In consideration of the result of pilot study, Chest spiral CT was performed in 217 patients by three different methods. We used 100cc nonionic contrast medium. Average attenuation of great vessels in the mediastinum were assessed in various injection methods. Image quality was graded with three levels of score by two radiologists. RESULTS: Peak enhancement time of the great vessels on pilot at dynamic static scan were as follows :52 sec at ascending aorta, 45 sec at pulmonary artery, and 40 sec at SVC. In the study of spiral CT, the highest attenMarion in the great vessels was obtained after injection of 100cc of contrast medium(2cc/sec, with 35-40 second scan delay), althrough artifact from highly enhancing SVC was most common in this method. Image quality were highest in the scans obtained with other methods(3-2-1cc/sec for 10-15-40 seconds, with 40 second scan delay). CONCLUSION: For chest spiral CT, authors recommend that scans should be obtained after infusion of 70--80cc of contrast medium during 35--40sec to obtain maximal vascular enhacement of mediastinum.
Aorta ; Artifacts ; Healthy Volunteers ; Humans ; Mediastinum ; Pilot Projects ; Pulmonary Artery ; Thorax* ; Tomography, Spiral Computed*