ABSTRACT
Objective To explore the chiaical value of cerebral perfusion reduction after subarachnoid hemorrhage(SAH)by multi spiral CT perfusion in rabbits.Methods 32 male Japanese big-ear rabbits of clean level were randomly divided into 2 groups:Group A(n =8),the normal group,were to obtain normal MS-CTP values of rabbit cerebrums;Group B(n =24),the SAH group was made into two-hemorrhage animal models,checked on seven day by multi spiral CT perfusion.The source data was transmitted to the post-processing workstation ADW 4.2.Perfusion parameters maps(CBF)of both sides of frontal,parietal and basal ganglia were got by computing.Each rabbit was killed immediately after scanning,and the spider blood was observed.Results The average CBF value of the two groups:The difference was not statistically significant at the frontal(t =1.740,P =0.092)and parietal(t =1.868,P =0.072); The average values of CBF were significantly decreased at the basal ganglia(t =2.481,P =0.019).Group B showed the distribution of blood clot in the basal cistern,but there was no blood clot at the frontal and parietal.Conclusion The monitor perfusion changes of rabbit brain after SAH could be detected by MS-CTP,and the lower of regional cerebral perfusion had a relationship with the distribution with the blood clot,and it could instruct the early diagnosis of cerebral perfusion,and the clinical benefit to early intervention treatment.
ABSTRACT
Objective To evaluate the imaging features,pathologic characteristics and diagnostic methods of gastrointestinal stromal tumor(GIST).Methods A retrospective study was performed to analyze the clinical pathological and imaging data of 14 GIST patients diagnosed by surgery and pathology.Results 14 cases of GIST were all solitary.10 cases were located in stomach and 4 cases in small intestine.Tumors were mostly round or oval,and a few of them were irregular lobulated.Immunohistochemistry analysis:12 cases were CDll7 positive and 9 cases were CD34 positive.Conclusion The imaging examination was important to the diagnosis and localization of GIST,but the final diagnosis of GIST depended on histopathological and immunohistochemical examination.
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Objective To evaluate the improvement of cone beam CT (CBCT) image quality by using bewtie filter (F_1) and water calibration. Methods First the multi-level gain calibration of the detector panel with the method of Cal_2 calibration was performed, and the CT images of CATPHAN503 with F_0 and bowtic filter were collected, respectively. Then the detector panel using water calibration kit was calibrated, and images were acquired again. Finally, the change of image quality after using F_1 and (or) water calibration method was observed. The observed indexes included low contrast visibility, spatial uniformity, ring artifact, spatial resolution and geometric accuracy. Results Comparing with the traditional combination of F_0 filter and Cal_2 calibration, the combination of bowtie filter F_1 and water calibration improves low contrast visibility by 13.71%, and spatial uniformity by 54. 42%. Water calibration removes ring artifacts effectively. However, none of them improves spatial resolution and geometric accuracy. Conclusions The combination of F_1 and water calibration improves CBCT image quality effectively. This improvement is aid to the registration of CBCT images and localization images.