ABSTRACT
Objective To analyze the causes and manifestations of non-pulmonary embolism induced perfusion defects (PDs) on dual-energy perfusion imaging (DEPI) using dual source CT.Methods Consecutive 208 patients without pulmonary embolism who underwent DEPI were reviewed retrospectively.The causes of PDs were analyzed by two radiologists, the pulmonary segment numbers, the proportion and the perfusion patterns of each case were recorded and analyzed respectively.Results 1 118 of 3 716 pulmonary segments showed the PDs.Among them, 752(67.26%), 36(3.22%), 308(27.55%) and 22(1.97%) pulmonary segments had PDs due to intra-pulmonary lesions, vascular diseases, artifacts and unidentifiable causes, respectively.In PDs resulted from intra-pulmonary lesions, vascular diseases and unidentifiable causes, three patterns (wedge-shaped, heterogeneous and regionally homogeneous) were identified,and most of those PDs were heterogeneous and regionally homogeneous, which were largely in accordance with the lesions showed on non-contrast enhanced scans.Artifacts included the beam hardening artifacts and artifacts caused by heart beat or diaphragmatic movement.The PDs caused by artifacts usually had particular locations and shapes.Conclusion Understanding of the manifestations and causes of PDs in patients without pulmonary embolism can improve the diagnosis accuracy of pulmonary embolism on DEPI.
ABSTRACT
The history,hardware,imaging principle and technical characteristics of dual-energy CT machine were described.The causes,clinical diagnosis and treatment of urinary calculi were analyzed.Dual-energy CT had its technical characteristics,clinical significance,advantages and practicality expounded in detail when used to determine the components of urinary calculi.
ABSTRACT
Aim To investigate the changes of behav-iors,neurotransmitters and depression related gene ex-pressions in hippocampus of C57BL/6 mice after olfac-tory bulbectomy (OB).Methods Forced swimming test (FST),tail suspension test (TST),open filed test (OFT),and elevated plus maze test (EPMT) were used to evaluate the behavioral changes 18 days after surgery. LC-MS/MS method was employed to measure the hippocampal neurotransmitters.Quantita-tive PCR approach was established to determine the hippocampal gene expressions associated with depres-sion.Results OB mice were hyperactive in OFT (P<0.05 ) accompanied with increased time spent in open arm of EPMT (P<0.01).Meanwhile,the sur-gery led to the reduction of the ratio of 5-HIAA/5-HT (P <0.01 ) but the increase of Glu/GABA (P <0.01 ) in hippocampus.Moreover,OB elevated the gene expressions of BDNF,Trkb,GDNF,CD1 1 b and TNF-αbut down-regulated that of TPH2 in hippocam-pus (P<0.05 ).Conclusion Behavioral alternation of OB mice was a result of comprehensive effect of the changes of neurotransmission and depression related genes,which call us special attention in using OB as an animal model for research and development of anti-depressants.