Objective To evaluate the value of computer-aided detection (CAD) system for pulmonary nodule detection using digital chest radiography in lung cancer screening. Methods One hundred consecutive digital chest radiographs from 6280 outpatients for lung cancer screening were independently reviewed by a thoracic radiologist and a computer-aided pulmonary nodule detection system.The radiographs were also reviewed by two experienced thoracic radiologists and the true nodules confirmed by two radiologists with reference to the CT images were marked and stored as a gold standard in the CAD system. The sensitivity and false positive of the radiologist and the CAD system for the detection of nodules on digital chest radiographs were compared. Results Ninety-five and 304 nodules were identified by radiologist and the CAD system, respectively. Of 134 nodules marked as true nodules by experienced radiologists, 82 (61.2%) and 105 (78. 4% ) nodules were identified by the radiologist and the CAD,respectively. The radiologist missed 35 true nodules which were only detected by CAD. The CAD system missed 10 true nodules which were only detected by radiologist. One hundred and twelve (83.6%) nodules were identified by radiologist with the CAD system. One hundred and ninety-nine nodules identified by CAD were false-positive with a rate of 2. 0 ( 199/100 ) per case. Conclusion Combining review of digital radiographs by radiologist with CAD system can improve the detection of pulmonary nodules in lung cancer screening.

Objective To explore the diagnostic value of spiral CT for the intestinal obstruction of unknown causes.Methods The CT findings of 115 intestinal obstructive patients with unknown causes were analyzed retrospectively.Results Of the 115 patients,the diagnosis of intestinal obstruction was comfirmed by CT in 110 cases patients,the correct diagnostic rate was 95.7%.Conclusions Abdominal CT is a rapid、simple and effective means for diagnosis of the location、cause and degree of obstruction in cases of intestinal obstruction with unknown cause.It can act as an important basis for the treatment program by doctors.