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Objective To investigate the optimal window level and center level settings in the diagnosis of costal cartilage fracture with 256-slice spiral CT through ROC analysis. Methods Thirty patients with suspected costal cartilage fractures underwent 256-slices chest spirals CT scaning. CT value of costal cartilage was measured by three experienced radiologists. The soft copy images of three kinds of window level and window width (-100 HU/1120 HU, 100 HU/1120 HU, 300 HU/1120 HU) were analyzed independently in PACS with dual-blind method, and the diagnosis results were taken ROC analysis with SPSS 16.0 software. The diagnostic accuracy of three physicians were evaluated and compared according to the area under the ROC curve (Az). Results A total of 8 patients of costal cartilage fractures were confirmed by CT diagnosis combined with clinical follow-up. The mean CT value of 30 patients was (98.78±32.86) HU. The area under the ROC curve with the window level and center level settings of (100 HU/1120 HU) were bigger than that of other window level and window width (P=0.045,P=0.002). Kappa identity test showed that there was a powerful conformability between the diagnostic results of three physicians. Conclusion 256-slice spiral CT is a good way for the diagnosis of costal cartilage fractures with suitable window level and center level settings.
RESUMO
Objective To investigate the optimal window width and window level for measuring the airway dimensions with spiral CT scan in Japanese white big-ear rabbits so as to lay the foundation for airway stenting in animal experiments. Methods Multi-slice spiral CT scanning of cervico-thoracic region was performed in 30 healthy adult Japanese white big-ear rabbits, the anteroposterior and transversal diameter of the thoracic trachea, the anteroposterior diameter of the right and left bronchus were measured with lung window, mediastinum window and special fat window separately. The revealing rate of the tracheal wall and the measuring results in different windows and levels were recorded and compared with the anatomical data. The differences of the relevant data were statistically analyzed. Results With lung window, the tracheal wall was well demonstrated, but the relevant data were smaller than that with mediastinum window. With mediastinum window, the data were bigger and the tracheal wall border appeared blurred. The results obtained with fat window were close to the actual anatomical data. Conclusion For accurately measuring the anteroposterior and transversal diameter of the thoracic trachea in Japanese white big-ear rabbits with multi-slice spiral CT scan, fat window should be adopted, which is helpful for the preparation of tracheal and bronchial stents.
RESUMO
Objective To improve the diagnostic accurate rate by studying best values of chest posterior-anterior digital medical images in soft-copy reading. Methods 100 normal adults’ chest posterior-anterior digital medical images in recent 10 days in our hospital were randomly chosen. Five specialists of our department were invited to see these images by soft-copy reading and the best WW/WL values of different parts of the chest they selected were recorded. All the data were analyzed in statistics and the best WW/WL was got. Results The best WW/WL values of soft tissues of chest wall were 2 083/4 840,ribs 2 667/4 908,lung fiber 2 067/4 960,hilum of lung 1 848/5 130,heart and large vessels 2 206/5 438,mediastinum and diaphragm 2 180/5 530,thoracic vertebrae 1 471/5 801,ribs that covered by heart and diaphragm1 428/5 975. Conclusion Different parts in chest poster -anterior digital medical images need special WW/WL in soft-copy reading for better diagnosis of images.