Objective To describe the CT characterization of retroperitoneal neuroganglionic tumor in order to get a better understanding of the disease. Methods Neuroganglionic tumors proved by operation and pathology (24 cases), as well as bone biopsy (2 cases), were studied in 18 males and 8 females. The mean age of neuroblastoma(14 cases), ganglioneuroblastoma(10 cases), and ganglioneuroma (2 cases) was 1 year 3 months, 3 years 6 months, and 6 years, respectively. Two cases of ganglioneuroma were complicated with leukemia and malignant pheochromocytoma. All cases were examined by CT scanning and 14 of them had contrast enhancement scanning preoperatively. 20 cases were also examined by ultrasound. Results The tumor sizes were 2.0 cm?2.5 cm?2.5 cm～16 cm?10 cm?8 cm. The tumors were all located in the retroperitoneal space, 22 cases were unilateral, 3 were situated in mid line prelumboscrally, and 1 was bilaterally located. The tumor were irregular in 20 cases and round shape in 6 cases; the tumor margin showed distinct in 14 cases and indistinct in 12 cases. Twenty five tumors showed mixture density and isointensity comparing with the kidney, 1 case with homogeneouse low density; 12 of 14 cases were enhanced inhomogeneously and 2 did not enhance; 23 of 26 cases showed different shapes of calcification. Retroperitoneal lymph nodes were swelling in 19 cases. Liver metastases were found in 3 cases, vascular encasement in 18 cases, tumor thrombus in inferior vena cava in 1 case,and tumor extending into spinal canal in 3 cases. Conclusion CT scanning can prompt the diagnosis of retroperitoneal neuroganglionic tumor and bolus injection of contrast medium can further increase the understanding of the abnormality within and around the tumor.

Objective To discuss the imaging features of skeletal changes in children with Gaucher disease on X-ray and MRI images.Methods One hundred and nine children with Gaucher disease were enrolled in this study.They all received routine X-ray for spine with anterior-posterior(A-P)and lateral view and bilateral femurs with A-P view.Among them.18 patients received X-ray for pelvic with A-P view.14 patients received X-ray for left wrist with A-P view.and 14 patients received MRI scan for femur.The MRI scan included T1-weighted imaging,T2-weighted imaging and fat-suppressed T2-weighted imaging with short tau inversion recovery(STIR)sequence.The imaging features of the X-ray and MRI images were analyzed retrospectively.Results The most common feature is osteoporosis,which presented in 91 cases (83.5%).Besides this,decreased density of metaphysis occurred in 86 cases(78.9%).erlenmeyer flask deformity of metaphysis occurred in 89 patients(81.7%),thinner cortex occurred in 69 cases(63.3%),osteolytic destruction occurred in 31 cases(28.4%).pathological fractures occurred in 26 cases (23.9%),osteosclerosis occurred in 12 cases(11.0%).cystic degeneration of bone occurred in 16 cases (14.7%),and dislocation of the hip occurred in 4 cases.All 14 patients received MRI presented abnormal signals.Among them,4 patients presented low signal intensity both on T1-weighted and T2-weighted images in bone marrow;the other ten presented high signal intensity mixed in low signal intensity areas on T2-weighted and fat-suppressed T2-weighted images.Conclusions The imaging features of skeletal changes in children with Gaucher disease are of some characteristics,which could provide useful information for the clinical treatment.

Objective:To monitor the susceptibility of common used antimicrobial agents against nosocomial Gram-negative bacilli in 2018 across China.Methods:Prospective collection of Gram-negative bacilli from 13 teaching hospitals nationwide from January to December 2018. The minimal inhibitory concentration (MICs) of antibiotics such as meropenem was determined by agar dilution methods and broth microdilution methods. Interpretation of results using the Clinical and Laboratory Standards Institute(CLSI) 2019 M100S (29th Edition) standard. Data were analyzed by using WHONET-5.6 software.Results:A total of 1 214 non-repetitive Gram-negative bacilli were collected, accounting for 96.7% (1 174/1 214) of blood and sterile body fluid samples. The activity of antimicrobial agents against 871 strains of Enterobacteriaceae was as follows in descending order of susceptible rate: amikacin (93.2%, 812/871), meropenem (92.0%, 801/871), ertapenem (88.9%, 774/871), imipenem (88.4%, 770/871), piperacillin-tazobactam (84.0%, 732/871), cefoperazone-sulbactam (83.1%, 724/871), cefepime (71.4%, 622/871), minocyline (68.9%, 600/871), ceftazidime (66.9%, 583/871), levofloxacin (54.4%, 474/871).The resistance rates of Escherichia coli to the third generation cephalosporins were 61.5% (155/252) (ceftriaxone) and 60.7% (153/252) (cefotaxime), respectively. The resistance rates of Klebsiella pneumoniae to the third generation cephalosporins were 56.6% (126/222) (ceftriaxone) and 57.9% (129/222) (cefotaxime), respectively. The incidence of extended-spectrum β lactamase (ESBLs) positive E. coli and K. pneumoniae was 50.2% (127/252) and 18.2% (40/222), respectively. Over 95% of all the ESBLs positive strains were susceptible to imipenem and meropenem. The incidence of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae was 2.8% (7/252) and 20.4% (45/222), respectively. For Enterobacter cloacae, Klebsiella aerogenes, Citrobacter freundii, the most susceptible agent were tigecycline (96.3%-100%), followed by amikacin (94.9%-97.1%), meropenem (89.8%-96.6%)and imipenem (89.8%-94.9%).The susceptibility of Proteus mirabilis, Morganella morganii and Serratia marcescens to meropenem and amikacin was over 90%.A total of 67 strains of carbapenems resistant enterobacteriaceae(CRE) were detected. Modified carbapenem inactivation method showed, 45 strains were serine carbapenemase and 20 were metalloenzymes. The susceptibility of Pseudomonas aeruginosa to meropenem and imipenem were 73.2% (112/153) and 66.0% (101/153), respectively. Acinobacter baumannii has the highest sensitivity to colistin (100%, 163/163), followed by tigecycline (87.1%, 142/163).Compared with other sources of infection, specimens of bloodstream infections were less resistant to Klebsiella pneumoniae (17.6%, 27/153 vs 21.7%, 15/69) and Acinetobacter baumannii (68.3%, 71/104 vs 71.2%, 42/59). Escherichia coli (2.5%,4/198 vs 0%,0/54) and Pseudomonas aeruginosa (37%, 33/89 vs 18.8%, 12/64) have a high proportion of carbapenem resistance. Conclusions:Carbapenems still maintain high antibacterial activity against Enterobacteriaceae bacteria, especially strains producing only ESBLs. Carbapenem-resistant Klebsiella pneumoniae should be given sufficient attention. Carbapenemase is the most important drug resistance mechanism of carbapenem-resistant Enterobacteriaceae in China.