ABSTRACT
Objective To approach the value of CT double windows technique in the location of lung X-ray knife.Methods The varying window width(W),window center(C) of peripheral type carcinoma of lung and their error were deltermined.The best double window was chosen and the clinical matherial was analysed.Results (1)The biggest error among different widow widths measuring foci was 7 mm.(2)The best double windows in the location of lung X-ray knife were W1 120~180,C1-700,W2 350,C2 15.(3)34 cases of lung carcinoma were observed with double windows,the outline of foci was contiuous and clear in the 15 cases of peripheral type carcinoma of lung and 8 cases of central type carcinoma of lung without hilum infiltration(67.6%),the inner outline of foci was disappear but could be remedied by mediastinum window in 11 cases of central type carcinoma of lung with hilum infiltration. Conclusion The double widows technique is provied with accuracy and without lack fidelity,and could reflect more condition of peritumour infiltration,it is clear superior to single display technique.