Does 18F-FDG PET/CT play a role in the differential diagnosis of parotid masses

AIM: The aim of the present study was to assess the accuracy of an hybrid PET/CT scanner in the evaluation of newly diagnosed parotid masses, comparing the results with those reported in the literature with using PET scanners only. METHODS: The potential role of 18F-FDG PET/CT in distinguishing benign from malignant parotid masses in 14 consecutive patients was investigated. All patients were preoperatively evaluated by means of ultrasound (US), US-guided fine needle aspiration (FNA) cytology, computed tomography (CT) scan, magnetic resonance imaging (MRI) and 18F-FDG PET/CT. For To interpreting FDG PET findings, the right to left parotid (R/L) SUV max ratio was calculated in a group of 54 patients without evidence of parotideal disease (mean+/-SD = 1+/-0.2; range = 0.8-1.2); considering the R/L SUV max ratio, focal or diffuse uptakes <0.8 or >1.2 were considered as potentially pathological. RESULTS: Imaging data were compared with surgical and histopathological findings. At FDG PET/CT, 9 false positive cases were found (8 Warthin's tumours, 1 pleomorphic adenoma), 1 false negative (acinar cell carcinoma), 4 true negative (1 Warthin's tumour, 1 pleomorphic adenoma, 1 lymph epithelial cyst, 1 parotid inflammation) whereas there was no case of true positive. The global accuracy of FGD PET/CT was rather low = at 29%. CONCLUSIONS: In agreement with other preliminary reports in which the FDG PET without CT fusion imaging was used, in our experience 18F-FDG PET/CT did not prove to play a significant role in differential diagnosis (benign vs malignant) of parotid masses. Further studies collecting larger groups of patients are needed to further elucidate this observation.     

~(18)F-FDG PET延迟显像在原发性肺癌诊断中的作用

目的:探讨18F-脱氧葡萄糖(FDG)PET延迟显像在原发性肺癌诊断中的价值。方法:对36例原发性肺癌患者分别进行18F-FDG PET早期头部——盆腔显像和注射后3h胸部延迟显像,测定2次显像病灶的标准摄取值(SUV),并计算18F-FDG的储留指数(RI)。结果:原发性肺癌的延迟显像SUV明显高于早期显像SUV(P<0.01);以早期显像SUV>2.5作为标准,原发性肺癌诊断的灵敏度、特异性、准确性分别为80.3%、72.7%、78.6%;以RI>20%作为标准,原发性肺癌诊断的灵敏度、特异性、准确性分别为82.8%、77.9%、80.3%;结合以上2项标准,原发性肺癌诊断灵敏度、特异性、准确性分别为90.0%、80.0%和86.7%。结论:18F-FDG PET延迟显像有助于原发性肺癌的诊断,结合应用SUV及RI2项指标可提高诊断准确率。     

螺旋CT对肺部孤立性结节诊断的探讨

目的利用螺旋CT扫描技术分析不同性质的孤立性肺结节的影像学特点,并探讨该方法在肺部结节定性诊断中的临床价值,提高对其的认识。方法对32例肺部结节的患者进行螺旋CT扫描,其中,9例进行了增强扫描,分别记录肺部结节的影像学特征进行分析。结果32例病例中,影像诊断良性病变24例(经临床确诊18例),影像诊断恶性病变8例(经临床确诊6例)。18例良性SPN中,15例呈边缘光滑;6例恶性SPN中,5例边缘呈分叶,4例有毛刺,2例见到支气管气像和空泡征。所有病例中,6例出现钙化。增强9例病人中,影像诊断恶性6例,良性3例。结论螺旋CT对肺部孤立性结节的良恶性的鉴别虽然有一定的困难,但若结合增强扫描、流行病学资料综合分析,仍有很大的诊断价值。     

~(18)F-FDG PET/CT扫描早期诊断重症急性胰腺炎继发感染的探讨

目的探讨氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描(~(18 )F-FDG PET/CT)在早期诊断重症急性胰腺炎(SAP)继发感染的评估价值。方法分别构建两种细菌(ATCC 25922和ATCC 25923)的SAP SD大鼠感染组模型,并以生理盐水构建对照组模型。分别在建模后0、1、3h检测动物全血细胞计数和血清淀粉酶,建模后3h行~(18)F-FDG PET/CT显像,并进行生物学分布、HE染色和Gram染色等验证PET显像结果。结果~(18 )F-FDG PET/CT显像提示,两种细菌感染组大鼠模型均显示胰腺部位的放射性浓聚灶;大肠埃希菌组、金黄色葡萄球菌组和生理盐水组靶(胰腺)/非靶(肌肉)比值(SUV)分别为4.22±0.61、4.32±1.21、2.26±0.35,两种细菌感染组模型动物SUV值无统计学差异(P0.05),大肠埃希菌感染组模型与对照组模型比较有统计学差异(P0.01)。生物学分布结果与PET显像结果一致。结论~(18)F-FDG PET/CT可以作为早期诊断SAP继发感染的检测方法。     

~(18)F-FDG PET和PET/CT在肾上腺病变鉴别诊断中的作用

目的:探讨18F-脱氧葡萄糖(FDG)PET或PET/CT显像在肾上腺病变鉴别诊断中的应用价值。方法:25例肾上腺占位患者均行18FDG PET或PET/CT图像,检查后1月内19例经手术切除,6例经穿刺活检获得病理结果,25例均有同期术前CT增强扫描。按照肾上腺占位是否产生内分泌症状分为有功能病变组(组A,8例)和无功能病变组(组B,17例),对18FDG PET或PET/CT图像所示肾上腺病变行半定量分析,计算肾上腺病变SUVm ax值及肾上腺病变/肝脏SUV-m ax比值。结果:1.有功能病变组的临床多表现为库欣综合征和高血压,良性病变SUVm ax为5.04±2.07,恶性病变的SUVm ax为8.33±2.57.良性肾上腺病变/肝脏SUVm ax的比值为2.52±0.62,恶性肾上腺病变/肝脏SUVm ax的比值为2.92±1.03。良性病变的大小为3.26±1.01 cm,明显小于恶性病变(7.80±1.82 cm)。2.无功能病变组,恶性病变的SUVm ax为11.39±7.96明显高于良性病变(1.93±0.54)。恶性肾上腺病变/肝脏SUVm ax的比值为4.51±2.92,明显高于良性肾上...     

Amyloid and tau imaging,neuronal losses and function in mild cognitive impairment

Objectives: Establish new approaches for early diagnosis of dementia, based on imaging amyloid and tau pathology, cell losses and neuronal function, in subjects with mild cognitive impairment (MCI),. The overall aim is to develop effective tools for monitoring disease progression in the living patient to facilitate discovery of early therapeutic interventions to modify the course of the disease.Design: Use 2-(l-(6-[(2-[F-18]fluoroethyl)(methyl)amino]-2-naphthyl)ethylidene)malononitrile ([F-18]FDDNP) in combination with positron emission tomography (PET) to produce dynamic images for quantification of regional cortical brain deposition in MCI patients and compare them with controls subjects and patients with Alzheimer’s disease (AD). Comparison with other molecular imaging probes for neuronal losses and function were also made.Setting: Patients are positioned supine in the tomograph bed with his/her head in the detector ring field. Upon injection of the molecular imaging probe (e.g., [F-18]FDDNP) images are obtained at very short time intervals for up to two hours. This results in dynamic sequences of brain distribution of the probe.Participants: Patients with clinical diagnosis of AD, MCI and control subjects.Measurements: Subjects in the categories established above were scanned with [F-18]FDDNP-PET and quantification performed using Logan parametric graphical analysis to measure relative quantitative amyloid loads throughout the brain within patient groups. These results were compared in the same patients with cell losses in hippocampus using 4-[F-18]fluoro-N-(2-[4-(2-methoxyphenyl)-l-piperazinyl]ethyl)-N-(2-pyridinyl)benzamide,([F-18]MPPF) and regional cerebral glucose metabolic rates using 2-deoxy-2-[F-18]fluoro-2-deoxy-D-glucose (2-[F-18]FDG).Results: [F-18]FDDNP reliably follows neuropathological progression (amyloid plaques [SP]; neurofibrillary tangles [NFT]) in the living brain of AD patients and those with MCI. The distribution of [F-18]FDDNP brain cortical accumulation correlates well with behavioral measures (e.g., MMSE scores) and follows known patterns of pathological distribution observed at autopsy. We have also established conversion of controls to MCI and MCI to AD with precision and sensitivity in patients and control subjects in follow-up studies. Moreover, we have established that hemispheric cortical surface mapping of [F-18]FDDNP binding is a powerful tool for assessment and visualization of the rate of brain pathology deposition. A strong correlation of [F-18]FDDNP binding, cell losses in hippocampus and decreased glucose utilization ([F-18]FDG PET) in several neocortical regions was found in the same AD and MCI subjects. Conclusions: The combined evaluation of [F-18]FDDNP PET (targeting NFT and_SP) with neuronal losses in the hippocampus and with [F-18]FDG PET (targeting neuronal function) offers the opportunity for reliable, noninvasive detection of MCI patients at risk for AD. The approach offers a glimpse to the molecular and cellular mechanisms associated with dementia and provides a means for their assessment in the living patient. Monitoring disease progression in MCI patients demonstrates the usefulness of this imaging approach for early diagnosis and provides a means for evaluation of neuroprotective agents and drugs aimed at prevention and modification of disease progression.     

^18F-FDG PET/CT在甲状腺肿瘤原发灶中的应用及SUVmax界值的探讨

目的评价18F-FDG PET-CT在甲状腺肿瘤原发灶的诊断价值。方法 45例经术前B超检查,共50个病灶怀疑甲状腺恶性肿瘤纳入研究,术前行18F-FDG PET/CT检查评价良恶性,术后病理诊断作为＂金标准＂,对比、评价18F-FDG PET/CT的诊断价值及探讨SUVmax的最佳诊断界值。结果 50个病灶,病理诊断26例为恶性肿瘤,24例为良性肿物。18F-FDG PET/CT诊断的敏感度为88.5%,特异度为79.2%。恶性组SUVmax高于良性组。SUVmax最佳诊断界值为1.810。结论对于B超怀疑的甲状腺恶性肿瘤,18F-FDG PET/CT有很好的诊断价值,寻找合适的SUVmax界值有助于提高诊断准确性。     

^18F-FDG和^18F—FLT PET／CT诊断肺结节的影响因素研究

目的探讨^18F—FDG（^18F-脱氧葡萄糖）和^18F-FLT（^18F-胸腺嘧啶）双核素PET／CT显像诊断肺结节的影响因素，以提高PET／CT对肺结节的诊断价值。方法选择肺结节患者55例为研究对象，其中男性33例，女性22例，年龄17—82岁，28例为肺内孤立结节，其余为2～3个结节，结节大小0．6～11．0cm，所有患者均行肺部^18F-FDG和^18F—FLTPET／CT检查，分析^18F—FDG和^18F-FLT标准摄取值（SUV）与肺结节患者的性别、年龄、结节大小及病理类型等相互关系和意义。结果55例肺结节患者，^18F—FDG和^18F-FLT标准摄取值与患者的性别、年龄、结节大小等均无关（P〉0．05），^18F-FDG标准摄取值与患者的病理类型无关（P〉0.05），而^18F—FLT标准摄取值与患者的病理类型有关，恶性肿瘤的SUVFLT大于良性肿瘤（P〈0．05）。结论肺结节患者结节的病理类型是影响^18F—FLT标准摄取值的重要因素，^18F—FLTPET／CT鉴别诊断肺结节良恶性具有重要的价值和意义。     

双源CT容积灌注成像技术在诊断孤立性肺结节中的应用价值

目的：探讨双源CT容积灌注成像技术在诊断孤立性肺结节（SPN）中的应用价值。方法选取2011年3月~2013年12月我院经病理确诊的116例SPN患者,均行双源CT容积灌注成像扫描,观察CT图像特征,并分析血容量（BV）、血流量（BF）、表面通透性（PS）、对比剂平均通过时间（MTT）等,计算可测层面的SPN平均灌注值。根据病理诊断结果进行SPN的良、恶性分组。结果恶性结节的BV、BF和PS值分别为（4.63±1.52）mL/100g、（98.36±48.25）mL/（100g·min）和（17.23±7.65）mL/（100g·min）,均显著高于良性结节病例值（2.28±1.76）mL/100g、（46.33±30.23）mL/（100g·min）和（7.42±7.28）mL/（100g·min）,差异具有统计学意义（P＜0.05）;恶性结节和良性结节的MTT值分别为（5.13±2.52）s、（6.16±4.88）s,差异无统计学意义（P＞0.05）。单独利用BV、BF或PS诊断SPN良、恶性的敏感性分别为95%、91%、86%;单独利用BV、BF或PS诊断SPN良、恶性的特异性分别68%、64%、77%。BV＋PS及BF＋PS联合诊断SPN良、恶性的特异性均为82%,较应用单个指标的特异性增高。结论采用双源CT容积灌注技术诊断和鉴别SPN可提高检出率,可为早期确诊提供证据。     

Neuropsychological and positron emission tomography correlates in idiopathic environmental intolerances

OBJECTIVES: It has been hypothesized that people with subjective hypersensitivity to chemicals may indeed suffer from neuronal damage due to widely distributed environmental toxins and that such deficits of diagnostic importance can be demonstrated with the help of functional neuroimaging even in single cases. In this study, a small group of well-characterized patients with idiopathic environmental intolerance were examined in order to identify such changes. METHODS: Twelve patients with idiopathic environmental intolerance were investigated neuropsychologically and underwent cerebral F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET). The imaging results were compared with findings from 17 healthy controls. RESULTS: Six patients showed deficits in verbal learning and memory, three of them also had a reduced information processing speed. In the individual analyses, 11 patients showed normal cerebral glucose metabolism. In the group analysis of the patients, no areas with significantly reduced glucose metabolism could be found. CONCLUSIONS: No consistent pathological cognitive performance and functional imaging pattern was found. It appears premature to claim specific neuropsychological or neuroimaging findings characteristic of idiopathic environmental intolerance. Therefore cerebral F-18 FDG PET should not be used to corroborate or rule out suspected idiopathic environmental intolerance, a syndrome whose potential biological underpinnings still need to be clarified.     

Use of a decision analysis model to assess the medicoeconomic implications of FDG PET imaging in diagnosing a solitary pulmonary nodule

This study assessed the use of positron emission tomography (PET) in identifying and diagnosing solitary pulmonary nodules (SPNs). For this a decision analysis model was constructed, and three alternatives were compared: wait and watch (WW), PET and anatomical computed tomography (PET), and CT plus PET (CT+PET). Transition probabilities were estimated from published data and consultations with experts. Costs of diagnosis were derived from the French reimbursement scale, and treatment costs from a national hospital database of diagnosis-related groups. The base case was defined as a 65-year-old male smoker with a 2-cm SPN and an associated high risk of malignancy of 43%. Evaluation criteria included incremental cost-effectiveness ratios and the proportion of unnecessary operations avoided in patients without malignant SPN. For the base case WW was the least effective and cheapest strategy. CT+PET was more effective and presented lower incremental cost-effectiveness ratio (€3,022 per life-year gained). It also was superior to PET in cost-effectiveness terms and resulted in 4.3% fewer unnecessary resections of benign SPN than did PET. Risk profile analyses performed on SPN malignancy risk showed that CT + PET remains the most cost-effective strategy in the range of 5.7–87%, and that WW is more cost-effective in the range of 0.3–5.0%. CT+PET is thus cost-effective in detecting malignant SPN in patients with a risk of malignity of at least 5.7% and may avoid inappropriate resections of benign SPN. These findings support the attempts to introduce a larger number of PETs in France for SPN diagnosis.     

The clinical application of 4D 18F-FDG PET/CT on gross tumor volume delineation for radiotherapy planning in esophageal squamous cell cancer

A combination of four-dimensional computed tomography with ¹⁸F-fluorodeoxyglucose positron emission tomography (4D CT-FDG PET) was used to delineate gross tumor volume (GTV) in esophageal cancer (EC). Eighteen patients with EC were prospectively enrolled. Using 4D images taken during the respiratory cycle, the average CT image phase was fused with the average FDG PET phase in order to analyze the optimal standardized uptake values (SUV) or threshold. PET-based GTV (GTV_PET) was determined with eight different threshold methods using the auto-contouring function on the PET workstation. The difference in volume ratio (VR) and conformality index (CI) between GTV_PET and CT-based GTV (GTV_CT) was investigated. The image sets via automatic co-registrations of 4D CT-FDG PET were available for 12 patients with 13 GTV_CT values. The decision coefficient (R²) of tumor length difference at the threshold levels of SUV 2.5, SUV 20% and SUV 25% were 0.79, 0.65 and 0.54, respectively. The mean volume of GTV_CT was 29.41 ± 19.14 ml. The mean VR ranged from 0.30 to 1.48. The optimal VR of 0.98, close to 1, was at SUV 20% or SUV 2.5. The mean CI ranged from 0.28 to 0.58. The best CI was at SUV 20% (0.58) or SUV 2.5 (0.57). The auto-contouring function of the SUV threshold has the potential to assist in contouring the GTV. The SUV threshold setting of SUV 20% or SUV 2.5 achieves the optimal correlation of tumor length, VR, and CI using 4D-PET/CT images.     

Combined imaging modalities: PET/CT and SPECT/CT

The recent development of new radiopharmaceuticals now permits molecular imaging of biologic processes at the cellular level to improve both the diagnosis and treatment of disease. Fused PET/CT and SPECT/CT imaging systems now provide metabolic and functional information from PET or SPECT combined with the high spatial resolution and anatomic information of CT. Because the two sets of images are fused, areas of normal and abnormal metabolic activity can be mapped to recognizable anatomic structures. This fusion of function and anatomy has quickly demonstrated its clinical value, especially in the field of oncology. There are also growing clinical indications in the areas of cardiology, neurology, and imaging of infection. F-18 fluorodeoxyglucose (FDG) is the PET imaging agent currently in most common use. While FDG uptake is nonspecific, it has demonstrated important applications, especially for patients with cancer. Continued progress in fused anatomic and molecular imaging can be anticipated, both in the development of more advanced instrumentation (integrated CT or MRI with PET and SPECT camera technology) and with new radiopharmaceuticals that image more specific physiologic aspects of organ and cell biology.     

甲状腺良、恶性结节中声脉冲辐射力弹性成像的诊断效果

目的针对甲状腺良、恶性结节中声脉辐射力弹性成像的诊断效果进行研究分析。方法随机选择2013年4月—2014年4月期间,在该院进行甲状腺结节诊断治疗的患者120例作为研究对象,所有患者采用成声脉冲辐射力弹性成像以及常规超声技术进行诊断检查,对甲状腺结节的良、恶性成像诊断的结果进行比较分析。结果使用声脉冲辐射力弹性成像对甲状腺良、恶性进行诊断,良性结节的SWV平均值与恶性结节的SWV平均值≤2.0 m/s,2.1-3.0 m/s,〉3.0 m/s所占的比例分别为51.67%、0.00%,50.00%、31.67%,15.00%、0.70%,均有显著差异,P值均〈0.05,具有统计学意义。甲状腺结节良性、恶性的SWV值分布分别为（2.24±0.79）、（5.06±2.87）,有显著差异,P〈0.05,具有统计学意义。甲状腺良性、恶性结节SWV与周围甲状腺组织的SWV比值的分布,≤1.0、1.0-2.0、〉2.0所占比例分别为28.33%、6.67%,63.33%、45.00%,8.33%、48.33%,均有显著差异,P值均〈0.05,具有统计学意义。结论在甲状腺良性、恶性结节的诊断中,应用声脉冲辐射力弹性成像技术进行诊断,可以将甲状腺结节的弹性特征呈现出来,在甲状腺结节的良性和恶性诊断、鉴别中,具有重要的意义。     

~(18)FDG PET对乳腺癌术后肿瘤标志物升高患者的价值

目的探讨18FDG-PET对乳腺癌术后肿瘤标志物升高患者的价值。方法对56例乳腺癌术后肿瘤标志物(CA153和/或CEA)升高患者进行18FDG-PET显像,所得结果与最后诊断比较,计算18FDG-PET的效能。结果 40/56例病人共发现18FDG放射性增高灶197个,经组织病理(手术或活检)、详细常规影像学检查及临床随访至少9个月,最后确定是否复发或转移。18FDG-PET真阳性34例,假阳性6例,真阴性13例,假阴性3例。18FDG-PET探测乳腺癌术后复发或转移的敏感性、特异性、准确性、阳性预测值、阴性预测值分别为91.9%(34/37)、68.4%(13/19)、83.9(47/56)、85.0%(34/40)、81.3%(13/16)。结论 18FDG PET对乳腺癌术后肿瘤标志物升高患者再分期具有重要意义,进一步影响临床管理。     

Operational radiation safety for PET-CT, SPECT-CT, and cyclotron facilities

Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are well- established and indispensable imaging modalities in modern medicine. State-of-the-art computed tomography (CT) scanners have now been integrated into multi-modality PET-CT and SPECT-CT devices, and these devices, particularly PET-CT scanners, are dramatically impacting clinical practice. 18F-fluorodeoxyglucose (FDG), by far the most widely used radiopharmaceutical for clinical PET imaging in general and oncologic PET imaging in particular, is highly accurate in detecting (approximately 90%) and staging many types of tumors, monitoring therapy response, and differentiating benign from malignant lesions. Several factors, including the relatively high administered activities [e.g., 370-740 MBq (10-20 mCi) of FDG], the high patient throughput (up to 30 patients per d), and in particular, the uniquely high energies (for a diagnostic setting) of the 511-keV positron-negatron annihilation photons, make shielding requirements, workflow, and other radiation protection issues important considerations in the design of a PET or PET-CT facility. The Report of Task Group 108 of the American Association of Physicists in Medicine (AAPM) provides a comprehensive summary of shielding design and related considerations, along with illustrative calculations. Whether in the form of a PET-CT or a SPECT-CT device, the introduction of CT scanners into a nuclear medicine setting has created new and complex radiation protection issues concerning the radiation burden and attendant risks accrued by patients undergoing such multi-modality procedures (especially in those instances in which higher-dose, diagnostic-quality CT studies are done as part of the PET-CT or SPECT-CT exam). In addition, because PET is dependent on the availability of short-lived 18F (Tp = 110 min) primarily in the form of FDG, and other short-lived positron emitters such as 11C (20 min), 13N (10 min), and 15O (2 min), cyclotrons for production of medically applied radionuclides and associated radiochemistry facilities are now widespread (well over 100 worldwide) and present their own radiation safety issues. In addition to the radioactive product, sources of exposure include neutrons and radioactive activation products in the various cyclotron components and surrounding shielding. Nonetheless, published studies have shown that the radiation doses to personnel working in cyclotron and associated radiochemistry facilities, as well as in PET or PET-CT and SPECT or SPECT-CT facilities, can be maintained below, and generally well below, the pertinent regulatory limits. This presentation will review the basic radiation safety aspects, including shielding and workflow, of these increasingly important and increasingly numerous facilities. The radiation burden accrued by the patients undergoing PET-CT or SPECT-CT exams will be considered as well.     

Quantifying the effects of iodine contrast media on standardised uptake values of FDG PET/CT images: an anthropomorphic phantom study

This study aimed to quantify the amount of change in Standardised Uptake Values (SUVs) of PET/CT images by simulating the set-up as closely as possible to the actual patient scanning. The experiments were conducted using an anthropomorphic phantom, which contained an amount of radioactivity in the form of Fluorodeoxyglucose (FDG) in a primary plastic test tube and one litre saline bags, including the insertion of bony structures and another two test tubes containing different concentrations of iodine contrast media. Standard scanning protocols were employed for the PET/CT image acquisition. The highest absolute differences in the SUVmax and SUVmean values of the saline bags were found to be about 0.2 and 0.4, respectively. The primary test tube showed the largest change of 1.5 in both SUVs; SUV max and SUVmean. However, none of these changes were found to be statistically significant. The clinical literature also contains no evidence to suggest that the changes of this magnitude would change the final diagnosis. Based on these preliminary data, we propose that iodine contrast media can be used during the CT scan of PET/CT imaging, without significantly affecting the diagnostic quality of this integrated imaging modality.     

多层螺旋CT诊断钙化性甲状腺结节的临床意义

目的探讨甲状腺结节的钙化特点对其良恶性诊断与鉴别诊断中的临床意义。方法对137例经病理和多层螺旋CT（MSCT）检查证实的甲状腺结节的临床资料进行回顾性分析。结果甲状腺结节MSCT的钙化检出率为21．60％（35／162）,良性结节为15．45％（19／123）,显著低于癌性结节的41．03％（16／39）;良性钙化粗大钙化的发生率显著高于恶性结节,而良性结节微小钙化的发生率显著低于恶性结节（P〈0．05）,但钙化灶数目与甲状腺恶性结节无显著性关系。结论甲状腺结节伴有钙化尤其是微小钙化灶是诊断甲状腺癌的重要征象。     

F-18 FDG PET in dementia

Glucose metabolism was measured by F-18 FDG PET in 33 patients with dementia. In patients with DAT, rCMRgl showed marked decrease in the associated areas in the temporo-parietal lobes, and it was relatively preserved in the primary cortices such as sensory, motor and visual areas. Frontal lobes were also involved in patients with advanced disease. In Pick disease, the frontal lobes were severely impaired. Multi-infarct dementia, Parkinson dementia and supranuclear palsy showed diffuse or multiple involvement throughout the entire brain. Correlation with rCMRgl and clinical severity was found in DAT patients. In conclusion, F-18 FDG PET is clinically useful in the differential diagnosis and grading of dementias.     

18F-FDG PET显像前行健康教育和清洁肠道对图像质量的影响

目的总结18F-FDG(氟代脱氧葡萄糖)正电子发射型计算机断层(PET)显像诊断肿瘤患者的护理体会,设法改善图像质量。方法94例肿瘤病人常规行18F-FDG显像。随机分为两组:有健康教育组49例患者检查前一天晚口服等渗溶液行清洁肠道,无健康教育组45例患者检查前未行清洁肠道,对两组图像质量进行对照比较。结果检查前有健康教育及有清洁肠道,肿瘤显像清晰度满意。检查前无健康教育及无清洁肠道肿瘤显像清晰度欠满意。结论设法放松患者情绪、控制血糖水平、检查前行清洁肠道对保障18F-FDG肿瘤代谢显像质量、实现影像分析并最终作出正确诊断具有重要作用。