PET脑显像及其他显像技术在放射性脑损伤诊断的对比性研究

目的 探讨^18F－脱氧葡萄糖（FDG）正电子发射型计算机断层显影（PET）脑显像和其他医学影像方法对早期诊断放射性脑损伤的价值，以达到预防、减少脑放射损伤的目的。方法 静脉注射^18F-FDG后行脑显像，获得横断面、冠状面、矢状面断层显像。所有病人均进行CT检查。结果 20例正常人脑PET显像图像可见大脑皮质各叶、基底神经节、丘脑及小脑放射性分布均匀对称。12例完成头颈部恶性肿瘤放疗后有临床症状者均检出不同程度局灶性脑组织葡萄糖代谢下降，显像阳性率100％；其中10例鼻咽癌放疗后PET结果提示放射脑损伤病灶共23处，最常见于颞叶病灶13处、脑干4处、小脑4处以及顶叶2处。2例脑胶质细胞瘤放疗病人，PET结果提示病灶：顶叶2处、颞叶1处、枕叶1处。12例放疗后病人CT检查仅10例提示放射性脑损伤。结论 PET脑显像能准确、早期诊断脑放射损伤，是头颈部恶性肿瘤肿瘤放疗后的非常重要的监测手段。     

Dopamine transporter dysfunction in Han Chinese people with chronic methamphetamine dependence after a short-term abstinence

Single-photon emission-computed tomography (SPECT) after the administration of ^99mTc-TRODAT-1 was performed on healthy subjects and subjects with methamphetamine (METH)dependence at time 1 (T1) after 24–48 h of abstinence, time 2 (T2) after 2 weeks of abstinence, and time 3 (T3) after 4 weeks of abstinence. In contrast to values in controls, the values of the striatal DAT specific uptake ratios (SURs) in subjects with METH dependence were significantly lower at T1 (n=25), T2 (n=9), and T3 (n=8); a mild increase in SURs was observed at T2 and T3, but values were still significantly lower than those in controls. In subjects with METH dependence, there was a trend for a negative correlation of striatal DAT SURs and craving for METH at T1. METH craving, anxiety and depression scores significantly decreased from T1 to T2 to T3. We conclude that Han Chinese people with METH dependence experience significant striatal DAT dysfunction, and that these changes may be mildly reversible after 4 weeks of abstinence, but that DAT levels still remain significantly lower than those in healthy subjects. The mild recovery of striatal DAT may parallel improvements in craving, anxiety and depression.     

18F-氟脱氧葡萄糖PET-CT诊断主动脉壁粥样硬化斑块的价值探讨

目的通过PET-CT明确18F-氟脱氧葡萄糖在主动脉壁粥样硬化斑块中摄取程度,探讨其临床价值。方法60例受检者,包括正常对照者6例,大动脉粥样硬化病例54例。测定主动脉壁粥样硬化部位标准化摄取值（SUV）和CT值,并依据CT值将54例主动脉壁局部18F-FDG高摄取的动脉粥样硬化病例分成3组,软斑块组CT值小于60HU,中等斑块组CT值介于60￣100HU之间,钙化斑块组CT值大于100HU。第4组为正常对照组。结果软斑块组42个测量部位的平均SUV为1.553±0.486;中等斑块组30个测量部位的平均SUV为1.393±0.296;钙化斑块组36个测量部位的平均SUV为1.354±0.189;正常对照组33个测量部位的平均SUV为1.102±0.141。多组之间比较差异具有统计学意义（F=678.909,P=0.000）;正常组与各斑块组比较差异具有统计学意义。结论18F-FDG在主动脉粥样硬化斑块中具有不同程度的摄取,其中软斑块对18F-FDG的摄取最高,提示18F-FDG PET-CT是诊断不稳定性主动脉粥样硬化斑块的有价值方法。     

改良直接注射法在SPECT显像应用的探讨

目的:探讨改良直接注射法在SPECT显像应用的效果。方法:将100例进行SPECT显像的患者,随机分成两组,用传统直接注射法和改良直接注射法注射99mTc-标记化合物。测量医护人员完成操作时间和注射器内放射性残留量。结果:传统直接注射法残留放射性活度明显高于改良直接注射法(P<0.01),而两者操作时间差异无统计学意义(P>0.05)。结论:改良直接注射法能显著减少注射器内放射性显像剂残留,保证SPECT检查质量。     

第二代双源CT双能量心肌灌注成像与SPECT心肌灌注的对照研究

目的对比SPECT,探讨双源CT(DSCT)双能量心肌灌注成像的临床应用价值。方法搜集18例临床怀疑冠心痛或已知冠心病史的患者行双源CT双能量心肌灌注成像和静息/负荷心肌灌注锝-99mSPECT显像检查,并对其影像表现进行分析。结果 DSCT双能量心肌灌注成像检查1 8例患者,发现阳性1 4例,阴性4例。对比SPECT检查,14例DSCT阳性病例中,SPECT均发现了相同心肌部位的灌注缺损。而4例阴性病例中,SPECT检查有1例有心肌缺血。二者检出心肌灌注缺损的差异性无统计学意义(P0.05)。结论DSCT双能量心肌灌注成像发现心肌灌注缺损的能力与SPECT大致相符,对冠心病的诊断有较大价值。     

13N-NH3PET在星形细胞瘤病理分级中的应用价值

目的：探讨^13氮-氨（^13N-NH3）正电子发射断层显像（PET）在脑星形细胞瘤病理分级中的应用价值。方法：47例拟诊胶质瘤患者进行^13N-NH3PET动态显像,所有患者均有MRI或CT检查结果,并且通过手术进行病理分级。分别进行定性和半定量分析,至少在三个断面同一位置连续两帧以上出现无摄取或相对低的摄取且病灶与健侧对应位置放射性计数比值小于1.2定为阴性,高度或中度摄取且病灶与健侧对应位置放射性计数比值大于1.2定为阳性;同时测定肿瘤组织（T）与脑白质（WM）的比值以及灌注指数（PI）。结果：29例星形细胞瘤中,经病理分级证实Ⅰ级4例,Ⅱ级8例,Ⅲ级9例,Ⅳ级8例。Ⅲ～Ⅳ级显像均见摄取（＋）;Ⅰ～Ⅱ级有1例未见摄取（-）。Ⅰ～Ⅱ级星形细胞瘤T/WM比值为0.97～2.07（1.62±0.67）,Ⅲ～Ⅳ级T/WM比值为1.75～2.53（2.18±0.48）。Ⅰ～Ⅱ级PI值为0.74～2.01（1.52±0.83）,Ⅲ～Ⅳ级PI值为1.92～2.69（2.33±0.54）。统计分析两组半定量指标（T/WM和PI）有显著性差异。结论：^13N-NH3PET可以对脑星形细胞瘤进行初步病理分级。     

Solitary pancreatic metastasis from a primary colonic tumor detected by PET scan

PURPOSE: A case of a solitary pancreatic metastasis from a primary colonic carcinoma is reported. METHODS: The history and use of carcinoembryonic antigen, computed tomography, and positron emission tomography in this case and the follow-up of colorectal cancer are reviewed. RESULTS: Recurrent disease was suspected by an increasing carcinoembryonic antigen level. However, conventional imaging with computed tomography on more than one occasion failed to identify any recurrence. The pancreatic metastasis was accurately localized by positron emission tomography scanning and confirmed on subsequent laparotomy. A histologically complete resection was performed and the patient remained in remission with a normal carcinoembryonic antigen 12 months postoperatively. CONCLUSION: This case reports an unusual site of solitary metastasis in colorectal cancer and supports the further investigation of positron emission tomography in follow-up of colorectal cancer.Presented in part at the meeting of the Association of Surgeons of Great Britain and Ireland, Cardiff, United Kingdom, May 23 to 26, 2000.     

急性脑出血患者局部脑血流量的研究

目的:研究急性脑出血(AICH)患者局部脑血流量(rCBF)的变化。方法:对88例AICH患者行脑血流单光子发射断层扫描(SPECT)显像,判定rCBF改变的部位及范围。结果:AICH患者远离出血灶的同侧、对侧大脑半球和对侧小脑半球缺血发生率分别为68.75%、31.25%、和48.75%。基底节出血最常引起皮层失联络的部位是额叶(78.5%),其次是颞叶(63%)、顶叶(58.5%)、对侧小脑(45.5%)和枕叶(25%)。肢瘫越重者发生对侧小脑失联络现象越高。结论:AICH可引起远离出血灶的大脑半球及对侧小脑半球缺血。随着病情改善,rCBF也有所恢复。     

18F-FDG符合显像在肺部肿瘤诊断中的临床应用

目的探讨18F-脱氧葡萄糖(FDG)符合显像在肺部肿瘤诊断中的临床应用价值.方法回顾性分析98例临床怀疑肺部肿瘤患者术前18F-FDG符合显像结果,观察各种病变摄取18F-FDG的情况及特征.结果98例被怀疑肺部肿瘤的病例中确诊为肺癌60例,其18F-FDG符合显像结果全部为阳性;肺部良性肿瘤9例,8例为阳性;确诊为肺结核20例,11例显像阳性;炎症9例,4例显像阳性.结论18F-FDG符合显像诊断肺部肿瘤具有很高的敏感性和准确性.对肺癌的分期亦具有重要的价值,但须结合临床对显像的特征进行分析,以提高对肺癌诊断的特异性.     

Decreased prefrontal, anterior cingulate, insula, and ventral striatal metabolism in medication-free depressed outpatients with bipolar disorder

This study explored whether cerebral metabolic changes seen in treatment resistant and rapid cycling bipolar depression inpatients are also found in an outpatient sample not specifically selected for treatment resistance or rapid cycling. We assessed 15 depressed outpatients with bipolar disorder (six type I and nine type II) who were medication-free for at least 2 weeks and were not predominantly rapid cycling. The average 28-item Hamilton Depression Scale (HAM-D) total score was 33.9. The healthy control group comprised 19 age-matched subjects. All participants received a resting quantitative ¹⁸F-fluoro-deoxyglucose positron emission tomography scan. Data analyses were performed with Statistical Parametric Mapping (SPM5). Analyses revealed that depressed patients exhibited similar global metabolism, but decreased absolute regional metabolism in the left much more than right dorsolateral prefrontal cortex, bilateral (left greater than right) insula, bilateral subgenual prefrontal cortex, anterior cingulate, medial prefrontal cortex, ventral striatum, and right precuneus. No region exhibited absolute hypermetabolism. Moreover, HAM-D scores inversely correlated with absolute global metabolism and regional metabolism in the bilateral medial prefrontal gyrus, postcentral gyrus, and middle temporal gyrus. Analysis of relative cerebral metabolism yielded a similar, but less robust pattern of findings. Our findings confirm prefrontal and anterior paralimbic metabolic decreases in cerebral metabolism outside of inpatients specifically selected for treatment resistant and rapid cycling bipolar disorder. Prefrontal metabolic rates were inversely related to severity of depression. There was no evidence of regional hypermetabolism, perhaps because this phenomenon is less robust or more variable than prefrontal hypometabolism.