1.The role of T1-weighted dynamic contrast-enhanced perfusion magnetic resonance imaging in gross target volume delineation of glioma patients
Xiaojuan YIN ; Zhensheng DENG ; Xiuchun ZHANG ; Junxin WU ; Jianji PAN
Chinese Journal of Radiation Oncology 2012;21(4):310-313
ObjectiveTo investigate whether the T1-weighted dynamic contrast-enhanced perfusion magnetic resonance imaging (DCEPMRI) technique can help to delineate the clinical target volume of brain glioma patients.MethodsThe DCE T1-weighted images from 28 glioma patients were collected after GdDTPA was injected.After the acquired images were processed and analyzed using modified Tofts-Kermode'two compartment analysis model and de-convolution method,the value and its pseudo mapping of quantitative parameter Ktrans related to microvascular permeability were obtained.The tumor size in the largest diameter slice measured both in routine enhanced MRI and Ktrans mapping of T1-weighted DCEPMRI were compared.ResultsThe vascular permeability and tumor infiltration was lower in low grade glioma,the difference of the tumor size between T1-weighted DCEPMRI and routine enhanced MRI reached 0.2% -0.3% there was significant difference of tumor size between T1 -weighted DCEPMRI and routine enhanced MRI ( grade Ⅰ and Ⅱ grade with 2.93 cm2∶2.46 cm2(t=6.90,P=0.000) and 4.18 cm2∶3.21 cm2(t=10.22,P=0.000) ).While in high grade glioma,the vascular permeability and the tumor infiltration were higher,the difference of the tumor size between T1-weighted DCEPMRI and routine enhanced MRI reached 25% - 26%( the size of grade Ⅲ and Ⅳ were 6.46 cm2 vs 5.48 cm2 ( t =10.83,P =0.000) and 8.26 cm2 vs 6.52 cm2(t =18.53,P =0.000) ).ConclusionsThe pseudo mapping of quantitative parameter Ktrans related to microvascular permeability acquired by T1-weighted DCEPMRI reflect the infiltrating circumscription in glioma,T1-weighted DCEPMRI can provide more information in delineation the clinical target volume,and it can be used as a new method for tumor volume evaluation.
2.Pathogens and antimicrobial resistance in community-associated and healthcare-associated urinary tract infection
Guangying HAN ; Keji SHAN ; Songting CHEN ; Jianji YIN ; Youyou MAO ; Xin XIONG
Chinese Journal of Infection Control 2015;(9):611-613,625
Objective To analyze the difference in constituent and antimicrobial resistance of pathogens in commu-nity-associated urinary tract infection(CA-UTI)and healthcare-associated UTI(HA-UTI).Methods Clinical data and microbial detection of urine specimens of 960 patients with UTI in a hospital between January 2013 and June 2014 were investigated retrospectively,difference in constituent and antimicrobial resistance of pathogens were ana-lyzed.Results 403 cases were CA-UTI,and 557 were HA-UTI;pathogens in both CA-UTI and HA-UTI were gram-negative bacteria,accounting for 78.16% and 66.97% respectively.Constituent of pathogens in CA-UTI and HA-UTI were significantly different(χ2 =21 .68,P <0.001 ).Resistant rates of Escherichia coli to piperacillin /tazobactam,cefazolin,cefoperazone / sulbactam,aztreonam,meropenem,ertapenem,gentamicin,and compound sulfamethoxazole were all significantly different between CA-UTI and HA-UTI (all P <0.05);Except aztreonam, resistant rates of Escherichia coli in HA-UTI to the other antimicrobial agents were all higher than CA-UTI.Re-sistant rates of Enterococcus faecium in HA-UTI to penicillin,ampicillin,gentamicin,levofloxacin,ciprofloxacin, and moxifloxacin were all higher than CA-UTI(all P <0.05).Conclusion Constituent and antimicrobial resistance of pathogens in CA-UTI and HA-UTI are different,proper antimicrobial agents should be chosen according to con-stituent features of pathogens and change in antimicrobial resistance,so as to prevent and reduce the emergence of drug-resistant strains,and improve therapeutic effectiveness.