^18F-FDGPET／OT检测骨转移瘤的临床价值

目的评价B-2-[^18F]-氟-2-脱氧葡萄糖（^18F-FDG）PET／CT显像在骨转移瘤中的诊断价值。方法回顾性分析118例被证实为恶性肿瘤骨转移患者的^18F-FDGPET／CT扫描情况,研究骨转移病灶形态学特征与代谢特征的关系及骨转移病灶代谢特征与原发肿瘤的关系,并比较了部分患者^18F-FDGPET／CT显像与^99mTc－亚甲基二膦酸盐（^99mTc—MDP）全身骨显像结果。结果溶骨性和混合性改变以显示高代谢病灶为主,它们分别与成骨性改变病灶及密度无改变病灶比较。差别均有统计学意义（P〈O．05）。^18F-FDGPET／CT显像和^99mTc—MDP全身骨显像诊断骨转移的灵敏度分别为90．4％,94．2％,特异性分别为98．8％,46．9％,准确性分别为92．9％,86．7％。^18F-FDGPET／CT显像诊断肿瘤骨转移的灵敏度与^99mTc—MDP全身骨显像无明显差别,但有更高的特异性和准确性。结论^18F-FDGPET／CT显像兼可反映骨转移灶不同的形态与代谢特征,较^99mTc-MDP全身骨显像有更高的特异性和准确性。对早期诊断多种肿瘤骨转移有重要价值。     

Using positron emission tomography to study human ketone body metabolism: A review

Ketone bodies – 3-hydroxybutyrate and acetoacetate – are important fuel substrates, which can be oxidized by most tissues in the body. They are synthesized in the liver and are derived from fatty acids released from adipose tissue. Intriguingly, under conditions of stress such as fasting, arterio-venous catheterization studies have shown that the brain switches from the use of almost 100% glucose to the use of > 50–60% ketone bodies. A similar adaptive mechanism is observed in the heart, where fasting induces a shift toward ketone body uptake that provides the myocardium with an alternate fuel source and also favorably affects myocardial contractility. Within the past years there has been a renewed interest in ketone bodies and the possible beneficial effects of fasting/semi-fasting/exercising and other “ketogenic” regimens have received much attention. In this perspective, it is promising that positron emission tomography (PET) techniques with isotopically labeled ketone bodies, fatty acids and glucose offer an opportunity to study interactions between ketone body, fatty acid and glucose metabolism in tissues such as the brain and heart. PET scans are non-invasive and thus eliminates the need to place catheters in vascular territories not easily accessible. The short half-life of e.g. 11C-labeled PET tracers even allows multiple scans on the same study day and reduces the total radiation burden associated with the procedure. This short review aims to give an overview of current knowledge on ketone body metabolism obtained by PET studies and discusses the methodological challenges and perspectives involved in PET ketone body research.     

Vascular Positron Emission Tomography and Restenosis in Symptomatic Peripheral Arterial Disease: A Prospective Clinical Study

ObjectivesThis study determined whether in vivo positron emission tomography (PET) of arterial inflammation (¹⁸F-fluorodeoxyglucose [¹⁸F-FDG]) or microcalcification (¹⁸F-sodium fluoride [¹⁸F-NaF]) could predict restenosis following PTA.BackgroundRestenosis following lower limb percutaneous transluminal angioplasty (PTA) is common, unpredictable, and challenging to treat. Currently, it is impossible to predict which patient will suffer from restenosis following angioplasty.MethodsIn this prospective observational cohort study, 50 patients with symptomatic peripheral arterial disease underwent ¹⁸F-FDG and ¹⁸F-NaF PET/computed tomography (CT) imaging of the superficial femoral artery before and 6 weeks after angioplasty. The primary outcome was arterial restenosis at 12 months.ResultsForty subjects completed the study protocol with 14 patients (35%) reaching the primary outcome of restenosis. The baseline activities of femoral arterial inflammation (¹⁸F-FDG tissue-to-background ratio [TBR] 2.43 [interquartile range (IQR): 2.29 to 2.61] vs. 1.63 [IQR: 1.52 to 1.78]; p < 0.001) and microcalcification (¹⁸F-NaF TBR 2.61 [IQR: 2.50 to 2.77] vs. 1.69 [IQR: 1.54 to 1.77]; p < 0.001) were higher in patients who developed restenosis. The predictive value of both ¹⁸F-FDG (cut-off TBR_max value of 1.98) and ¹⁸F-NaF (cut-off TBR_max value of 2.11) uptake demonstrated excellent discrimination in predicting 1-year restenosis (Kaplan Meier estimator, log-rank p < 0.001).ConclusionsBaseline and persistent femoral arterial inflammation and micro-calcification are associated with restenosis following lower limb PTA. For the first time, we describe a method of identifying complex metabolically active plaques and patients at risk of restenosis that has the potential to select patients for intervention and to serve as a biomarker to test novel interventions to prevent restenosis.     

18F‐Fluorodeoxyglucose (FDG)‐PET features of focal nodular hyperplasia (FNH) of the liver

Abstract: Aim: The aim of this paper is to describe the imaging pattern of focal nodular hyperplasia (FNH) by ¹⁸F‐fluorodeoxyglucose (18F‐FDG) positron emission tomography (PET). Methods: Eight consecutive asymptomatic patients with histologic proof of FNH underwent 18F‐FDG PET imaging. The lesions were found incidentally. The 18F‐FDG PET imaging was performed with a dedicated PET tomograph after intravenous injection of 300–370 MBq 18F‐FDG. The 18F‐FDG accumulation in the lesions was (semi)quantified by calculating the standardized uptake value (SUV) and SUV has been corrected for the lean body mass (LBM). Eight patients with liver metastases spread from melanoma (n=2) and colorectal carcinoma (n=6) served as controls. The size of the FNH lesions and of the control group ranged from 2.0 to 8.5 cm (mean 4.83 cm±2.37) and from 1.5 to 6 cm (mean 3.28±1.52), respectively. Results: While in malignant liver lesions the accumulation of 18F‐FDG was significantly increased, all FNH lesions showed normal or even decreased accumulation of 18F‐FDG. In FNH lesions, SUV ranged between 1.5 and 2.6 (mean 2.12±0.38), whereas all liver metastases showed an increased SUV ranging between 6.20 and 16.00 (mean 10.07±3.79). The SUV corrected for LMB (SUV_LBM) was similar to the SUV and ranged between 0.9 and 2.2 (mean 1.81±0.41) for FNH and between 5.9 and 16.3 (mean 9.15±4.03), respectively. Conclusion: In contrast to liver metastases, there is no increased glucose metabolism in FNH in vivo. The imaging feature of FNH by 18F‐FDG‐PET imaging is not specific for FNH; however, it may be helpful to differentiate FNH from liver metastases in cancer patients if radiological methods are not diagnostic.     

18F‐FDG PET/CT and MRI in the follow‐up of head and neck squamous cell carcinoma

We evaluated the diagnostic performance of ¹⁸F‐FDG PET/CT and MRI for the assessment of head and neck squamous cell carcinoma (HNSCC) relapse. Since early treatment might prevent inoperable relapse, we also evaluated THE performance of early unenhanced ¹⁸F‐FDG PET/CT in residual tumor detection. The study was prospectively performed on 32 patients who underwent ¹⁸F‐FDG PET/CT and MRI before treatment and at 4 and 12 months after treatment. ¹⁸F‐FDG PET/CT was also performed 2 weeks after the end of radiotherapy. Histopathology or a minimum of 18 months follow‐up were used as gold standard. Before treatment ¹⁸F‐FDG PET/CT and MRI detected all primary tumors except for two limited vocal fold lesions (sensitivity 94%). MRI was more sensitive than ¹⁸F‐FDG PET/CT for the detection of local extension sites (sensitivity 75 vs 58%), but at the cost of a higher rate of false positive results (positive predictive value 74 vs 86%). For relapse detection at 4 months, sensitivity was significantly higher for ¹⁸F‐FDG PET/CT (92%) than for MRI (70%), but the diagnostic performances were not significantly different at 12 months. For the detection of residual malignant tissue 2 weeks post‐radiotherapy, sensitivity and specificity of ¹⁸F‐FDG PET/CT were respectively 86 and 85% (SUV cut‐off value 5.8). ¹⁸F‐FDG PET/CT is effective in the differentiation between residual tumor and radiation‐induced changes, as early as 2 weeks after treatment of a primary HNSCC. For follow‐up, performance of ¹⁸F‐FDG PET/CT and MRI are similar except for a higher sensitivity of ¹⁸F‐FDG PET/CT at 4 months. Copyright © 2011 John Wiley & Sons, Ltd.     

18F-FDG PET/CT Findings in a Breast Cancer Patient with Concomitant Tuberculous Axillary Lymphadenitis

Although ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) is a sensitive modality for detecting a malignant lesion, increased ¹⁸F-FDG uptake is also seen in infected or inflammatory processes. Here, we report the case of a breast cancer patient with concomitant tuberculous axillary lymphadenitis that showed increased ¹⁸F-FDG uptake. A 39-year-old woman underwent preoperative ¹⁸F-FDG PET/computed tomography (CT) as a part of the work-up for right breast cancer. ¹⁸F-FDG PET/CT images showed a malignant lesion in the right breast with moderate ¹⁸F-FDG uptake, and multiple enlarged right axillary lymph nodes with intense ¹⁸F-FDG uptake. Subsequently, the patient underwent right mastectomy and right axillary lymph node dissection. Histopathological examination confirmed breast cancer and tuberculous lymphadenitis, and the patient was treated concomitantly with anti-tuberculous therapy.     

Application of modern neuroimaging technology in the diagnosis and study of Alzheimer's disease

Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer's disease. However, it is not yet possible to easily detect these abnormalities using head computed tomography in the early stages of the disease. In this review, we evaluated the ways in which modern imaging techniques such as positron emission computed tomography, single photon emission tomography, magnetic resonance spectrum imaging, structural magnetic resonance imaging, magnetic resonance diffusion tensor imaging, magnetic resonance perfusion weighted imaging, magnetic resonance sensitive weighted imaging, and functional magnetic resonance imaging have revealed specific changes not only in brain structure, but also in brain function in Alzheimer's disease patients. The reviewed literature indicated that decreased fluorodeoxyglucose metabolism in the temporal and parietal lobes of Alzheimer's disease patients is frequently observed via positron emission computed tomography. Furthermore, patients with Alzheimer's disease often show a decreased N-acetylaspartic acid/creatine ratio and an increased myoinositol/creatine ratio revealed via magnetic resonance imaging. Atrophy of the entorhinal cortex, hippocampus, and posterior cingulate gyrus can be detected early using structural magnetic resonance imaging. Magnetic resonance sensitive weighted imaging can show small bleeds and abnormal iron metabolism. Task-related functional magnetic resonance imaging can display brain function activity through cerebral blood oxygenation. Resting functional magnetic resonance imaging can display the functional connection between brain neural networks. These are helpful for the differential diagnosis and experimental study of Alzheimer's disease, and are valuable for exploring the pathogenesis of Alzheimer's disease.     

18F-FDG PET/CT与MRI在评价鼻咽癌颅底骨转移中的价值

目的比较18F-脱氧葡萄糖正电子发射体层摄影术(FDG PET)/CT与MRI在鼻咽癌(NPC)颅底骨转移的检出率,为诊断NPC颅底骨侵犯提供依据。方法对25例NPC患者同时行MRI1、8F-FDG PET/CT检查,比较两种方法对颅底骨侵犯的检出率。结果 MRI检出颅底骨侵犯16例,PET/CT检出21例,肿瘤侵犯颅底骨最多的部位是枕骨斜坡(14例),其次是蝶骨体(12例),差异无统计学意义(P=0.096)。其中PET/CT检出溶骨型侵犯11例,MRI检出2例,差异有统计学意义(P=0.047)。PET/CT检出成骨型侵犯6例,MRI检出6例,差异无统计学意义(P=1.000)。PET/CT检出混合型侵犯4例,MRI检出8例,差异无统计学意义(P=0.207)。结论 PET/CT与MRI都是NPC颅底骨转移的有效检查手段,PET/CT对溶骨型侵犯的检测优于MRI,且在对放疗靶区的定位中,PET/CT优于MRI。     

Early evaluation for treatment efficacy of 5-fluorouracil and hyperthermia on HCT-116 colon cancer cells by fluorine-18-fluorodeoxyglucose uptake

Backgroud  Fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography imaging can be used to assess the treatment efficacy of chemotherapy and prognosis. The aim of this study was to determine the uptake rate of ¹⁸F-FDG in colon cancer HCT-116 cells, and to evaluate the treatment efficacy of chemotherapy, hyperthermia and thermo-chemotherapy through the uptake inhibition rate of ¹⁸F-FDG.

Methods  The uptake rate of ¹⁸F-FDG in HCT-116 cells was determined at various experimental conditions. The inhibition rate of cell growth, uptake rate of ¹⁸F-FDG and uptake inhibition rate of ¹⁸F-FDG in HCT-116 cells treated with 5-fluorouracil (5-FU) at various concentrations were determined. In HCT-116 cells subjected to chemotherapy (5-FU, 100 μg/ml), hyperthermia (43°C, 40 minutes) and thermo-chemotherapy for 24 hours, the inhibition rate of cell growth and uptake inhibition rate of ¹⁸F-FDG were determined; early apoptosis, the morphology and ultrastructure of HCT-116 cells were examined; and the contents of glucose and lactate dehydrogenase (LDH) in the cell culture medium of HCT-116 cells were determined. One-way analysis of variance (ANOVA) and correlation analyses were conducted by using SPSS 16.0 software.

Results  The uptake rate of ¹⁸F-FDG in HCT-116 cells was (44.25±2.19)%. Under the condition of adding 5-FU at various concentrations for 24 hours, the uptake rate of ¹⁸F-FDG was negatively correlated with 5-FU dosage (r= –0.879, P <0.01); the inhibition rate of cell growth revealed a positive correlation with the uptake inhibition rate of ¹⁸F-FDG (r=0.831, P <0.01). In HCT-116 cells subjected to hyperthermia, chemotherapy, and thermo-chemotherapy for 24 hours, the uptake inhibition rates of ¹⁸F-FDG were (12.94±2.80)%, (28.25±4.59)%, and (21.60±3.68)%, respectively. The early apoptotic rates of HCT-116 cells were (9.80±0.16)%, (19.80±2.40)%, and (15.70±1.80)%, respectively. Moreover, the contents of glucose and LDH in cell culture medium of HCT-116 cells after treatments were higher than those before treatment.

Conclusion  The uptake inhibition rate of ¹⁸F-FDG can be used for early evaluation of hyperthermia and 5-FU treatment efficacy on cancer cells although hyperthermia (43°C, 40 minutes) does not reveal the synergistic effect on 5-FU at the low dosage.

     

18F-FDG PET/CT显像在诊断乳腺癌中的价值

目的探讨18F-脱氧葡萄糖（Fluorine-18 fluorodeoxyglucose,FDG）正电子发射计算机断层显像（positrone mission computer tomography,PET/CT）在乳腺癌术前诊断中的价值。方法 27例乳腺包块的女性患者,PET/CT全身显像行鉴别诊断和分期。PET/CT结果由手术病理证实。结果病理证实15例为乳腺癌,12例为良性包块。15例中PET/CT诊断阳性14例,漏诊1例,其它影像学方法（CT、乳腺钼靶、超声）诊断11例;12例中PET/CT诊断阴性10例,误诊2例,其它影像学方法诊断阴性7例。PET/CT在诊断乳腺癌的灵敏度、特异性、准确性、阳性预测值和阴性预测值分别为14/15（93.3%）、10/12（83.3%）、24/27（88.8%）、14/16（87.5%）、10/11（90.1%）。病理证实15例乳腺癌中的12例有同侧腋窝淋巴结转移,18F-FDGPET/CT诊断阳性10例,假阴性2例。结论 18F-FDGPET/CT显像是鉴别诊断乳腺癌的较准确方法。