阿尔茨海默病等痴呆疾病的脑功能影像学研究

痴呆类疾病可分为阿尔茨海默病（AD）、皮克病、多发性梗死性痴呆（MID）等类型。它们各具不同的临床特点,神经心理学检查对痴呆的诊断及鉴别诊断起一定作用。AD等痴呆疾病的神经影像学发展越来越迅速,其中^18F-FDGPET脑功能显像技术可以早期发现AD患者大脑皮层顶,颞叶等区域葡萄糖代谢率降低,并且左,右半球不对称。^18F-FDGPET方法还可以鉴别诊断AD与其他痴呆类疾病。     

~(18)F-FDGPET显像在肿瘤学中的应用

从 (氟代脱氧葡萄糖 )在正常人体内的分布角度考虑 ,使用 PET进行 1 8F- FDG显像可应用于脑肿瘤、结直肠癌、淋巴瘤、黑色素瘤、肺癌以及头颈部肿瘤等。美国核医学会 (SNM)已报道 1 8F- FDG显像在原发性脑肿瘤、乳腺癌、骨肿瘤、肺癌、前列腺癌、黑色素瘤及淋巴瘤等中的应用。初步结果表明 ,葡萄糖代谢在坏死型及持续型生长肿瘤中有明显差别 ,当肿瘤局部 FDG利用减低 ,提示治疗后有明显效果。本文简要综述 1 8F- FDG PET显像在乳腺癌、胰腺癌、肝细胞癌、肌肉骨骼肿瘤、内分泌肿瘤、生殖泌尿道肿瘤和胃食道肿瘤中的应用。     

18F-FDG PET显像在恶性淋巴瘤中的应用

18F-FDG(18F-氟代脱氧葡萄糖)PET显像作为一种功能显像技术,能反映肿瘤组织中的生化变化和代谢状态,对淋巴瘤的准确分期、恶性程度评价、治疗疗效评价、治疗后复发的诊断以及预后估计等方面均具有重要作用.     

PET在头颈部肿瘤的应用

ET检查在头颈部肿瘤的原发和转移灶诊断中发挥重要的作用,尤其是在肿瘤治疗的评价方面,通过图像融合技术有助于其临床推广应用。     

18F-FDG PET显像在鉴别胰腺良恶性肿块中的应用价值

18F-氟代脱氧葡萄糖(18F-FDG)PET显像诊断和鉴别诊断胰腺良恶性肿块有较高的特异性、敏感性、阳性预测率和阴性预测率,并对胰腺癌有无肝、肺等远处和淋巴转移、治疗方案的确定和肿块切除后随访等有着重要的实际应用价值。     

18F-FDG PET显像在肝癌中的应用

18F-FDG PET在肝脏的原发肿瘤和转移性肿瘤的诊断中有重要价值,特别是在肝肿瘤的诊断、分期和治疗方案的选择方面.结合CT、MRI和超声可以提高诊断的准确性,同时,在对肝肿瘤疗效监测以及评价手术效果方面也有重要作用.     

PET显像在卵巢癌诊断中的作用

卵巢癌的早期诊断、复发及疗效的监测对提高卵巢癌的疗效具有重要意义 ,1 8F- FDG PET在诊断卵巢癌及其术后复发均有重要的临床价值 ,联合应用超声、MRI和 CT可以提高卵巢癌影像诊断的准确性。对于急性高血糖症者 ,可用 1 1 C标记药物进行 PET显像     

18F-FDG PET显像在肺癌中的应用

18F-FDG(18F-氟代脱氧葡萄糖)PET可以反映正常机体组织和肿瘤细胞的功能状态,在对肺部病变的定性诊断、肺癌的临床分期、疗效评价、复发监测以及预后估计上都明显优于CT、MRI等形态解剖学检查,而且能间接提供瘤组织细胞分化程度和增殖潜能的判断依据,具有重要的临床应用价值。由于PET在空间分辨率上存在不足,应与其他影像学检查相结合,以提高其准确性。     

啮齿动物18F-FDG脑摄取影响因素的分析

小动物18F-氟脱氧葡萄糖（FDG）PET脑显像是脑科学基础研究的重要手段。在动物实验中,饮食、麻醉、显像剂的给药途径、温度及光照等实验条件均会影响其脑部活动,使脑灌注和代谢显像出现整体偏倚,进而影响对脑认知功能的判断。笔者就啮齿动物显像研究中不同实验条件对18F-FDG脑摄取的影响进行综述,为动物显像研究提供指导。     

分化型甲状腺癌~(18)F-FDG PET显像的临床应用

低分化型甲状腺癌细胞摄取碘能力的下降或丧失导致 1 31 　 I WBS(全身显像 )假阴性 (约 2 0 % ) ,高水平的血清 Tg(甲状腺球蛋白 )只能说明有分化型甲状腺癌 (DTC)的复发或转移 ,不能确定 DTC复发或转移的具体位置 ,而低分化型甲状腺癌正是 DTC病人死亡的主要类型。本文主要探讨 1 8F- FDG(1 8F-氟代脱氧葡萄糖 ) PET显像在1 31　 I的 WBS阴性而血清 Tg水平增高的 DTC病人中鉴别复发和转移的应用以及评价 DTC病人预后的价值 ,当嗜1 8F- FDG肿瘤显示的体积大于 12 5 m L 或 FDG标准摄取值大于 10 g/ m L 时 ,病人的预后不良。     

Abnormality Pattern of F-18 FDG PET Whole Body with Functional MRI Brain in Post-Acute COVID-19

PurposeThe study aimed to investigate imaging abnormalities associated with post-acute COVID-19 using F-18 FDG PET/CT and PET/ rsfMRI brain.MethodsWe retrospectively recruited 13 patients with post-acute COVID-19. The post-acute COVID-19 symptoms and neuropsychiatric tests were performed before F-18 FDG PET/CT whole body with PET/rsfMRI brain. Qualitative and semiquantitative analyses were also conducted in both whole body and brain images.ResultsAmong the 13 patients, 8 (61.5%) had myositis, followed by 8 (61.5%) with vasculitis (mainly in the thoracic aorta), and 7 (53.8%) with lung abnormalities.. Interestingly, one patient with a very high serum RBD IgG antibody demonstrated diffuse myositis throughout the body which potentially associated with immune-mediated myositis. One patient experienced psoriasis exacerbation with autoimmune-mediated after COVID-19. Most patients had multiple areas of abnormal brain connectivity involving the frontal and parieto-temporo-occipital lobes, as well as the thalamus.ConclusionThe whole body F-18 FDG PET can be a potential tool to assess inflammatory process and support the hyperinflammatory etiology, mainly for lesions in skeletal muscle, vascular wall, and lung, as well as, multiple brain abnormalities in post-acute COVID-19. Nonetheless, further studies are recommended to confirm the results.     

Alzheimer disease and other dementias

This article offers an overview of Alzheimer disease (AD) and its differential diagnosis from other dementias. After completing it, readers will: Be familiar with the prevalence of AD and other dementias. Summarize the major causes of dementia. Understand the basic pathology of AD. Recognize the common cognitive and noncognitive symptoms of AD. Identify the risk factors for AD and methods to prevent the disease. Describe the evaluation and diagnosis of AD. Discuss the role of structural and functional imaging in dementia diagnosis. Know how physicians manage AD symptoms. Assimilate this knowledge for use in encounters with patients with Alzheimer disease.     

18 FDG PET监测肺癌化疗反应的临床应用

目的 ^18FDG PET监测肺癌化疗效果以调整治疗方案。方法：18例肺癌患者经化疗后1—3月行^18FDG PET全身扫描，评价化疗后疗效，18例均有CT结果比较。结果：18例复发和转移者15例，^18FDG PET发现14例，CT发现13例。原发病灶消失且无复发和转移者3例，^18FDG PET确定3例，CT检查确定2例。监测肺癌化疗效果^18FDG PET敏感性为93．3％，特异性为100％。CT检查敏感性为86．7％，特异性为66．7％。结论：^18FDG PET全身扫描监测肺癌化疗效果优于CT检查。是监测肺癌化疗效果较好的影像方法，能预测治疗效果。     

Direct comparison of [18F]FDG PET/CT with PET alone and with side-by-side PET and CT in patients with malignant melanoma

Purpose

The purpose of this retrospective, blinded study was to evaluate the additional value of [¹⁸F]FDG PET/CT in comparison with PET alone and with side-by-side PET and CT in patients with malignant melanoma (MM).

Methods

A total of 127 consecutive studies of patients with known MM referred for a whole-body PET/CT examination were included in this study. PET alone, side-by-side PET and CT and integrated PET/CT study were independently and separately interpreted without awareness of the clinical information. One score each was applied for certainty of lesion localisation and for certainty of lesion characterisation. Verification of the findings was subsequently performed using all available clinical, pathological (n?=?30) and follow-up information.

Results

The number of lesions with an uncertain localisation was significantly (p?p?p?=?0.057) compared versus PET alone. Respectively, PET, side-by-side PET and CT and PET/CT showed a sensitivity of 86%, 89% and 91%, a specificity of 94%, 94% and 94%, a positive predictive value of 96%, 96% and 96% and a negative predictive value of 80%, 83% and 87%.

Conclusion

Integrated PET/CT offers a significant benefit in lesion localisation and an improvement in lesion characterisation compared with PET alone or with side-by-side PET and CT. The benefit is not as great as that reported for other tumour entities, which may be due to the high avidity of MM for [¹⁸F]FDG.     

Tritium in [O]water containing [F]fluoride for [F]FDG synthesis

The presence of tritium in enriched [¹⁸O]water irradiated with 9.6 MeV protons used to produce [¹⁸F]fluoride by the ¹⁸O(p, n)¹⁸F reaction was inferred from the cross sections and threshold energies of the ¹⁸O(p, t)¹⁶O reaction, and the existence of tritium was confirmed experimentally. Tritium was also detected in both [¹⁸O]water recovered for recycling and waste acetonitrile solutions. The purified [¹⁸F]FDG was not contaminated with ³H. The amount of ³H discharged into the air was far less than the International Basic Safety Standard Level.     

Single photon tomography in Alzheimer's disease and the dementias

Measurements of brain blood flow has evolved over the past 50 years, and during the latter half of that time radionuclide techniques have been used to study this important function. Using Xenon 133 and scintillation multiprobe systems, several teams of investigators measured regional cerebral blood flow (rCBF), and noted that under many circumstances it could be equated with local brain physiological activity. The dementias were investigated using the scintillation multiprobe method, and posterior flow deficits were described in patients who were thought to have Alzheimer's disease. The multiprobe technique gave way first to planar, and then tomographic imaging, with initial favorable results achieved by positron emission tomography (PET). Soon investigators learned to measure rCBF with single-photon emission computed tomography (SPECT) using high-sensitivity systems and 133Xe as a tracer, or high-resolution systems with 123I-iodoamphetamine (IMP), and later, 99mTc-HMPAO. Three-dimensional tomographic imaging shows to advantage the flow patterns that characterize Alzheimer's disease, with rCBF reductions in temporal, parietal, and sometimes frontal areas, as opposed to randomly distributed deficits in multiinfarct dementia, reduced frontal flow in entities such as Pick's disease, and others. Herein we will review our own experience with high-sensitivity rCBF SPECT in 119 patients with dementia, and with high-resolution SPECT, using a new, three-camera scanner and 99mTc-HMPAO in an additional 39 patients. SPECT rCBF study of patients with dementia and Alzheimer's disease, will aid in separating patients with untreatable Alzheimer's from those patients who may have treatable causes of dementia, and will be useful in evaluating experimental drugs for the treatment of Alzheimer's disease.     

Copper-62 ATSM as a hypoxic tissue tracer in myocardial ischemia

Copper-62 labeled diacetyl-bis(N4-methylthiosemicarbazone) (62Cu-ATSM) has been proposed as a generator produced positron-emitting tracer for hypoxic tissue imaging. To clarify the usefulness of 62Cu-ATSM for myocardial ischemia, 62Cu-ATSM PET was performed in 7 patients with coronary artery disease. Increased myocardial uptake of 62Cu-ATSM was observed (myocardium/blood ratio: 3.09) in one patient with unstable angina, who had increased 18F-fluorodeoxyglucose (18F-FDG) uptake under the fasting condition. The other 6 patients, who were clinically stable, did not have increased 62Cu-ATSM uptake, although abnormal 18F-FDG uptake was seen in 4 patients. This preliminary study suggests that 62Cu-ATSM is a promising PET tracer for hypoxic imaging in acute ischemia.     

F-18 FDG PET in detecting renal cell carcinoma

Purpose: To assess the role of F-18 FDG imaging with a dual head coincidence mode gamma camera (Co-PET) in the detection of renal cell carcinoma (RCC) in patients with renal masses.

Material and Methods: An F-18 FDG Co-PET study was performed in 19 patients (7 F, 12 M; mean age 58.15±2.5 years, age range 45-79 years) with suspected primary renal tumors based on conventional imaging techniques, including computed tomography (CT) and ultrasonography (US) before nephrectomy or surgical resection of the mass.

Results: Histologically documented RCC was present in 15 patients. Of the 19 patients with suspected primary renal tumors, F-18 FDG Co-PET was true-positive in 13, false-negative in 2, true-negative in 3, and false-positive in 1 patient. Two angiomyolipomas and one renal mass due to infarction and hemorrhage showed a true-negative Co-PET result. The patient with false-positive FDG Co-PET study was diagnosed as xantogranulomatous pyelonephritis. Overall sensitivity, specificity, and accuracy of FDG Co-PET for RCC were 86% (13/15), 75% (3/4), and 84% (16/19), respectively. Positive predictive value for RCC was 92% and negative predictive value 60%.

Conclusion: These findings suggest that F-18 FDG Co-PET may have a role in the diagnostic evaluation of patients with RCC and primary staging of disease. Positive F-18 FDG study may be predictive of the presence of RCC. However, a negative study does not exclude the RCC.