PurposeTo optimize the imaging parameters of clinical MRI scanner in rat pancreas imaging to improve the image quality and to provide better MRI image quality and more economical research method for imaging study of rat pancreas. Materials and Methods Twenty-four healthy male Wistar rats were randomly divided into the conventional sequence (CS) group, the adjustment sequence (AS) group and the optimization sequence (OS) group, with 8 rats in each group. The rats in the CS group were scanned with conventional parameters using a clinical MRI scanner. The principle of parameter adjustment was: parameters associated with T1WI or T2WI imaging quality (TR, TE, slice thickness, NEX, FOV and matrix) was set with four changes, and only one of the six parameters was changed in each scan, image quality was evaluated by two senior radiologists, the parameter corresponded the best image quality evaluated consistently by two radiologists were selected as the optimal imaging parameter, all the optimized parameters were set up step by step in this way which formed the imaging parameters in OS group. The pancreatic signal intensity and signal to noise ratio was compared between CS group and OS group after imaging.Results The optimized sequence parameters in clinical MRI scanner were listed below: T1WI sequence (M3D/FSPGR/15): TR 6 ms, TE 2.5 ms, slice thickness 2.0 mm, NEX 8, FOV 7 cm×7 cm, Matrix 120×120; T2WI sequence (FSE-XL/90): TR 4000 ms, TE 71 ms, slice thickness 2.0 mm, NEX 1, FOV 8 cm×8 cm, Matrix 192×160. The pancreatic SI in T1WI and T2WI sequence of the OS group were significantly higher than those in the CS group (t=5.16 and 3.80,P<0.01), while the pancreatic SNR in T1WI and T2WI sequence of the OS group were significantly higher than those in the CS group (t=5.65 and 3.26,P<0.01).Conclusion The optimized parameters can improve the imaging quality of rat pancreas MRI significantly, thus provide a reference for the related experimental study.

ObjectiveTo examine the clinical utility of four methods in diagnosis of tuberculous meningitis.Methods A total of 60 patients with tuberculous meningitis were included as study group and another 70 patients with non-tuberculous intracranial infection as control group. Four methods, including conventional acid fast stain,Myobacterium tuberculous culture in BACTEC MGIT 960, real-time lfuorescent quantitative polymerase chain reaction (FQ-PCR) and modiifed acid fast stain, were used to assay the cerebrospinal lfuid specimens for diagnosis of tuberculous meningitis.ResultsThe positive rate was 11.7% (7/60), 6.7% (4/60), 48.3% (29/60), and 61.7% (37/60), respectively in the study group as tested by the four methods. There was signiifcant difference between the four methods in the positive rate (P< 0.05). Modiifed acid fast stain was more sensitive than the other 3 methods in identifying tuberculous meningitis (P< 0.05). This method also could identify the intracellularM. tuberculosis. All the 8 samples from the 4 patients who were positive for culture ofM. tuberculosis were positive in the modiifed acid fast stain.Conclusions The modiifed acid fast staining method is simple, fast, signiifcantly more senstive in detection of the acid fastM. tuberculosis in CSF, either extracellular or intracellular. It is worthwhile to further investigate its usefulness in early diagnosis of tuberculosis meningitis.