Objective To analyze the reasons of discarding as useless of ?-Se direct conversion digital flat panel detector (?-Se FPD). Methods (1) E-COM DR-2000CTM chest system, with high frequency X-ray machine made by CPI company of Canada, the X-ray tube made by VARIAN company of America and Direct Ray-1000 ?-Se FPD made by DRC company of America. (2) 50 cases were collected rondomizedly, each had 4 pieces of chest image and were analyzed by two experienced radiologists and two technicians. Results After about 14 months with 30,000 times exposure efficacious, some damage lines and points appeared in the detector. After about 34 months with 70,000 times exposure efficacious, a damage region (area is 6.7in*0.95in ) existed, this reduced the images' quality and at the end the detector was discarded as useless. Conclusion The ?-Se FPD needs maintenance and monitoring working circumstance.

Objective To explore the MR findings of extra?abdominal desmoid?type fibromatosis and the related features of recurrence. Methods MRI and clinical data of 36 cases of extra?abdominal desmoid?type fibromatosis proved by surgical pathology were retrospectively reviewed between March 2010 and October 2016.The ages of the cases ranged from 10 years to 68 years. 14 males and 22 females were included with sex ratio 1∶1.57.the courses of the disease were varied from 1 day to 8 years. The stage was based on Church′s method. 3 cases were only with plain scan and other 33 cases with contrast enhancement. Sagittal or coronal T1WI, STIR?T2WI, PdWI and contrast enhanced T1WI in horizontal, sagittal and coronal view were examined on MR siganl 1.5T or 3.0T of GE Company. Two groups were divided based on the recurrence or not after surgery. The clinical and MR features were analyzed between the two groups with χ2 test, t test or Spearman rank correlation analysis according to the data characteristics. Results Compared with signal intensity of muscle, 34 cases were isointense and 2 cases isointense with hypointense area on T1WI; 34 cases were hyperintense and 2 cases hyperintense with hypointense area on T2WI. On contrast enhanced imaging, 22 cases were markedly enhanced, 7 cases moderately enhanced and 4 cases mildly enhanced.15 cases was with recurrence and 21 cases without recurrence. Infiltration of surrounding tissue was shown in 14 cases(38.9%), 13 cases with recurrence and 1 cases without recurrence. Band sign was shown in all cases. Tentacle sign was shown in 18 cases (50.0%), 15 cases with recurrence and 3 cases without recurrence. Split fat sign was shown in 12 cases (33.3%) and all without recurrence. Fascial tail sign was shown in 15 cases (41.7%), 13 cases with recurrence and 2 cases without recurrence. Hypointense ring around the tumor was shown in 21 cases (58.3%), 2 cases with recurrence and 19 cases without recurrence. The P value of tentacle sign, split fat sign, hypointense ring around the tumor, fascial tail sign and infiltration of surrounding tissue was less than 0.05. Gender, location and the degree of contrast enhancement was without difference of statistical significance between the two groups. There was significant correlation of the recurrence rate with the courses and the stage of the disease(χ2=7.264 , r=0.994 , P<0.05). Conclusions Tentacle sign, fascial tail sign and infiltration of surrounding tissue were attributed to the estimate of recurrence of extra?abdominal desmoid?type fibromatosis, and Be features contributes to the diagnosis and therapy of extra?abdominal desmoid?type fibromatosis.

Objective To investigate CT features of Chlamydia psittaci(C.psittaci)pneumonia patients.Methods Ten patients with C.psittaci pneumonia were collected retrospectively based on macro gene second-generation sequencing(mNGS).The radiological manifestations of the disease were analyzed.Results Seven patients(70%)had contact history with birds(poultry)or their feces.Chest CT on the day of admission was mainly mass patchy consolidation,all of which were located in single lung,involving 8 cases(80%)with one lobe and 2 cases(20%)with two lobes.All of them were accompanied by air bronchogram,9 cases(90%)with ground glass shadow and 8 cases(80%)with interstitial changes.One case(10%)showed a reversed halo sign,and 1 case(10%)showed fan-shaped consolidation.Nine cases(90%)showed progress with increased fusion or new lesions within nine days.Conclusion CT findings of C.psittaci pneumonia have certain characteristics,and combining with history of contacting birds(poultry)can suggest diagnosis.