BACKGROUND: In the ischemic cerebral area there are viable tissues of low blood perfusion. Theses tissues can be rescued as long as blood supply is restored timely. As an imaging agent,99Tcm-HL91 can be used to demonstrate the viable cerebral tissues in hypoxic and ischemic area.OBJECTIVE: To investigate the value of 99Tcm-HL91 imaging in assessing ischemic stroke,in order to provide evidences for early intervention.DESIGN: An observational and controlled trial based on patients and healthy voluinteers.SETTING: A nuclear medicine department in a university and a neurological department and a nuclear medicine department in a provincial hospital.PARTICIPANTS: From March 2000 to September 2001,eighteen inpatients and outpatients suffering from ischemic cerebral diseases and 4 volunteers were enrolled in the study.METHODS: In the 18 patients,11 were clinically diagnosed as cerebral infarction,5 TIA,2 vertebrobasilar insufficiency. All the subjects underwent 99Tcm-HL91 cerebral hypoxia tomographic imaging. The labeled 99Tcm-HL91(555-1 110 MBq) was intravenously injected into the human body and imaging was conducted after 20 -30 minutes,17 patients underwent CT or MRI examination at the same time. Eleven patients underwent 99Tcm-ECD tomopraphic imaging on the next day. The results of the 3 examinations were compared with each other. The uptake in the inside and around-infarct areas was determined by direct visual observation on the images. Positive change was given by presence of increased uptake and negative by absence. The uptake change that could not be clearly defined as positive or negative was considered critical level. But the uptake on both hemispheres was compared with ROI technology. The change over 25% between hemispheres was set as positive and the other was negative. So there was no critical group in this study.MAIN OUTCOME MEASURES: The results of cerebral hypoxia imaging,CT,MRI and cerebral perfusion imaging.RESULTS: Among the 18 patients,5 were positive for hypoxia imaging(4infarction and 1 vertebrobasilar insufficiency). In the 99Tcm-ECD perfusion,6out of 11 patients manifested of regional decreased blood perfusion. Nine patients manifested of abnormal CT or MRI results. No abnormalities were detected in the 4 volunteers.CONCLUSION: Although 99Tcm-HL91 imaging for diagnosis of cerebral ischemic disease is affected by many factors,it can identify whether the ischemic tissue is hypoxic or necrotic when the perfusion imaging demonstrate low flow. So it helps in guiding rehabilitation intervention and foretelling prognosis.

Objective To investigate the feasibility of monitoring the tumor's hypoxic changes by 99Tcm-2-(2-methyl-5-nitro-1H-imidazol-1-yl) ethyl eihydrogen phosphate (MNLS) imaging after radiotherapy.Methods (1) H22 cells were cultured and mice model with liver cancer xenografte was made.The mice were imaged at 0.5,1,2,3,4,6 and 8 h (six mice in each group) after injected with 7.4 MBq 99TcmMNLS when the tumor size reach about 1 cm.Then the mice were sacrificed.The T/NT and ％ID/g of each time point was calculated.(2) The liver cancer bearing mice of radiotherapy group (25 Gy) and control group were imaged at 0,24,48 h,and then the technique of ROI was adopted to calculate the T/NT at each time point in the two groups.Immunohistochemical stain method was used to evaluate the expression level of HIF-1α in liver cancer.(3) One-way analysis of variance,the least significant difference t test,two-sample t test and Spearman correlation analysis were performed.Results (1) The uptake of 99TcmMNLS in the liver cancer bearing mice was significant at 2 h after injection and the ％ID/g was the highest.99Tcm-MNLS was excreted mainly through kidneys.(2) The T/NT and HIF-1α expression level in radiotherapy group at 24 h (2.65±0.27,(50.62±3.78)％) were lower than those at the instant (3.35±0.19,(85.32±0.94)％,t=5.640,6.701,both P＜0.05),but higher than those at 48 h (2.23±0.52,(21.69±0.75)％,t=7.674,4.911,both P＜0.05).The T/NT and HIF-1α expression in the radiotherapy group were significantly higher than those in the control group at the instant (2.74 ± 0.29,(28.26 ± 1.70) ％,t =4.235,3.473,both P＜0.05) but lower at 48 h (3.15±0.88,(67.64±3.55) ％,t =7.902,3.258,both P＜0.05).However,no significant difference was observed at 24 h between radiotherapy group and the control group (2.98±0.16,(58.45±0.98) ％,t =0.525,2.043,both P＞0.05).The change of T/NT closely correlated with the expression of HIF-1α in both the radiotherapy group and control group(r,=0.793,0.756,both P＜0.05).Conclusion 99Tcm-MNLS hypoxia imaging has potential to monitor changes of hypoxia in tumor after radiotherapy.

Purpose To explore the features of 99Tcm-AnnexinⅤscintigraphy of venous thrombus and its feasibility of discriminating fresh venous thrombus from old one. Materials and Methods The rabbits (n=15) were randomly divided into three groups (fresh thrombus group, old thrombus group and control group). The inferior vena cava thrombus models were developed in the rabbits of thrombus groups by inserting screw cooper wire into inferior vena cava. The rabbits of control group received sham operation. 99Tcm-AnnexinⅤwas injected in the rabbits of fresh thrombus group and control group one day after operation;the same was done in the rabbits of old thrombus group 14 days after operation. Planar anterior abdominal images were obtained at 30, 60, 90 and 120 min after 99Tcm-AnnexinⅤinjection in all groups respectively. The ratios of thrombus to background of the two thrombus groups and the ratios of the area correspondent to the thrombus groups to background of the control group were calculated by ROIs counts. Then rabbits were executed, and thrombus was used for pathology examination. Results 99Tcm-AnnexinⅤuptake in thrombi was clearly visualized in all rabbits of the fresh thrombus group;whilst negative images showed in all rabbits of the old thrombus group and control group. The thrombus to background ratios of the fresh thrombus group (4.06±0.49) were higher than that of the old thrombus group (2.46±0.38), and also higher than the inferior vena cava below inferior pole of right kidney level to background ratios (2.27±0.24) of the control group (t=5.746, 7.318;P<0.05). All the thrombi of the fresh thrombus group were confirmed as fresh mixed thrombi by HE staining, and those of the old thrombus group were confirmed as old mixed organized thrombi. Conclusion 99Tcm-AnnexinⅤmay become a new acute venous thrombus imaging tracer used to discriminate fresh venous thrombus from old one.

Objective To explore the effects of cognitive behavioral therapy and citalopram on regional cerebral blood flow(rCBF)in the patients with depression disorder.Methods 38 patients with depression disorder were divided into the cognitive behavioral therapy group(n=18),and citalopram group(n=20).The rCBF changes and scores of Hanmilton Depression Scale(HAMD)of all patients in two groups were evaluated with 99Tcm-ECD single photon emission computed tomography(SPECT)and HAMD before and after treatment.Results After treatment,the symptoms of all patients in two groups improved,but the cases of the citalopram group got a rapid improvement compared with those of the cognitive behavioral therapy group.Both of two methods could increase blood flow in right basal ganglion;while,the blood flow also increased in right limbic system in the cognitive behavioral therapy group,and in right temporol lobule in the citalopram group.Conclusion Both cognitive behavioral therapy and citalopram are effect on symptoms of depression disorder,but affect blood flow in different parts.

Objective To explore the influence of different injection techniques on the quality of bolus in 99mTc-DTPA renal dynamic imaging.Methods 395 patients accepted 99mTc-DTPA renal dynamic imaging were retrospectively analyzed.All patients were divided into three groups according to injection techniques:direct injection group (187 cases),intravenous route injection group (84 cases)and venous indwelling needle injection group (124 cases).The three groups were injected by each technique.Areas of interest (ROI) were drawn on abdominal aorta by Xeleris workstation in blood flow perfusion imaging.The time-radioactivity curves of ROI were got.The patients whose ROI curve formed a peak was successfully injected,and did not formed was unsuccessfully injected.The number of patients in three groups who were successfully or unsuccessfully injected was respectively calculated.The data of three groups was taken Chisquare test by SPSS17.0 software.Results 174 patients of the direct injection group,46 of the intravenous route injection group and 115 of the venous indwelling needle injection group were injected successfully.The successful rate respectively was 93.0％,54.8％ and 92.7％.The successful rate of the direct injection group and venous indwelling needle injection group were higher than intravenous route injection group.The difference had statistical significance.The successful rate of the direct injection group and venous indwelling needle injection group hadn't statistical significance.Conclusions The successful rates of the direct injection group and venous indwelling needle injection group were similar.The venous indwelling needle injection technique can be chosen.The successful rate of the intravenous route injection group was lower than the other two groups.The intravenous route injection technique should be chosen prudently.

Objective To explore the protective effect and mechanism of glycyrrhizic acid on hippocampal neuron injury in epileptic rat models. Methods The epileptic rat models were established by lithium and pilocarpine kindling. The successful models were randomly divided into epilepsy group and glycyrrhizic acid group. In addition, the rats without any treatment were used as the normal control group, with 12 rats in each group. Hippocampal neuron injury and apoptosis were detected by Nissl and TUNEL staining. Mitochondrial membrane potential in the hippocampal neurons of rats was detected by JC-1 method. The activity of aspartic acid protein hydrolase 3 (caspase 3) and caspase 9 was detected by colorimetric assay. The expressions of cleaved-caspase 3, 9, B lymphocyte tumor-2 (Bcl-2), Bcl-2 related X protein (Bax), cytochrome C (CytC) and apoptotic protease-activating factor (Apaf-1) protein in the hippocampal tissues of rats were detected by western blot assay. Results Compared with the normal group, the number of neurons was reduced (P＜0. 01), the number of TUNEL-positive cells was increased (P＜ 0. 01), mitochondrial membrane potential was decreased (P＜ 0. 01), caspase 3 and 9 activity was increased (P＜ 0. 01), the expressions of Bcl-2 and mitochondrial CytC were down-regulated (P＜ 0. 01), the expressions of Bax, cytoplasm CytC and Apaf-1 were up-regulated (P＜ 0. 01) in the epilepsy group. Compared with the epilepsy group, the number of neurons was increased (P ＜ 0. 01), the number of TUNEL-positive cells was reduced (P＜ 0. 01), mitochondrial membrane potential was increased (P＜ 0. 01), caspase 3 and 9 activity was decreased (P ＜ 0. 01 ), the expressions of Bcl-2 and mitochondrial CytC were up-regulated (P ＜0. 01), the expressions of Bax, cytoplasm CytC and Apaf-1 were down-regulated (P ＜ 0. 01) in the glycyrrhizic acid group. Conclusions These results suggest that glycyrrhizic acid can inhibit the hippocampal neuron injury in epileptic rats by blocking the mitochondrial pathway.

Objective To explore the impact factors of liver uptake of 18F-FDG in PET/CT imaging,and to preliminary analyze the application of maximum standardized uptake values corrected by conventional body mass,lean body mass and body surface area (SUVmax-B,SUVmax-L,SUVmax-S).Methods A retrospective analysis was performed on 67 healthy subjects who underwent 18F-FDG PET/CT.SUVmax-B,SUVmax-L and SUVmax-S were measured,and the impact of age,levels of fasting blood glucose,body mass index (BMI),CT value of liver,gender and the fatty liver on SUVmax-B,SUVmax-L and SUVmax-S were analyzed.Results The liver SUVmax-B,SUVmax-L,SUVmax-S were positively correlated with the levels of fasting blood glucose (r=0.329,0.336,0.353,P =0.012,0.010,0.007).There was a positive correlation between BMI and SUVmax-B (r=0.543,P＜0.01),SUV-L (r=0.328,P=0.007),while BMI value had no correlation with SUVmax-S (r=0.026,P=0.833).There was no correlation between age,CT value of the liver nor SUVmax-B,SUVmax-L and SUVmax-S (all P＞0.05).The liver SUVmax-B (t=2.608,P=0.011) and SUVmax-L (t=5.272,P=0.001) of male were significantly higher than those of female,while there was no difference between male's and female's liver SUVmax-S and liver SUVmax-S (t=0.759,P=0.450).There was no difference in SUVmax-B,SUVmax-L nor SUVmax-S between fatty liver subjects and non-fatty liver subjects (P=0.646,0.775,0.068).Conclusion The fasting blood glucose level,BMI and sex are the impact factors of liver uptake of 18F-FDG in PET/CT imaging.SUVmax-B can be replaced by SUVmax-L or SUVmax-S for larger BMI subjects,while SUVmax-S can make up differences between different genders.However,correction techniques can not weaken the impact of blood glucose level on SUVmax value of liver.

Objective To observe the 18F-FDG PET/CT manifestations of primary systemic anaplastic large cell lymphoma(ALCL).Methods A total of 21 patients with primary systemic ALCL were enrolled,and PET/CT manifestations were observed.Results Among 21 cases of ALCL,there were 15 cases of ALK+and 6 cases of ALK-.Affected lymph nodes in multiple site were observed in 19 cases,mainly located in the neck(n=13),mediastinum(n=12 cases)or retroperitoneum(n=12),while single site affected lymph node was notice in 2 cases.Extranodal organs/site involvements were found in 12 cases,including 6 cases of soft tissue(such as skin,muscles,etc.),4 cases of bone,14 cases of organs,including 4 cases of lung,3 cases of liver,2 cases of pancreas,2 cases of kidney,2 cases of gastrointestinal tract and 1 case of thyroid.Among 21 cases of ALCL,19 with irregular lymph node morphology and fused into clusters,17 with uniform density,3 with necrosis and 1 with calcification.All ALCL lesions in 21 cases showed hypermetabolism,the maximum standard uptake value(SUVmax)and the mean standard uptake value(SUVmean)of the affected lymph node was 17.04±9.94 and 9.96±6.15,respectively,while the metabolic tumor volume(MTV)and total lesion glycolysis(TLG)of all lesions was 92.54(67.61,249.21)cm3 and 723.46(419.78,1 461.17)g,respectively.The maximum diameter of the affected lymph node was not significantly correlated with SUVmax nor SUVmean(both P＞0.05),but positively correlated with MTV and TLG of all lesions(r=0.696,0.767,both P＜0.001).Ann Arbor staging was positively correlated with the maximum diameter,SUVmax and SUVmean of the affected lymph node,also MTV and TLG of all lesions(r=0.467,0.458,0.702,0.780,0.664,all P＜0.05).Conclusion 18F-FDG PET/CT manifestations of primary systemic ALCL were characteristic,with significant changed metabolic parameters,including SUVmax,SUVmean,MTV and TLG.