F-18 fluorodeoxyglucose PET/CT scanning in the diagnostic work-up of a primary pericardial mesothelioma: a case report

Primary mesothelioma of the pericardium is a very rare malignancy. The antemortem diagnosis is difficult and requires a multidisciplinary approach. The use of F-18 fluorodeoxyglucose-positron emission tomography/computed tomography whole body scan has been recently advocated to improve staging and to monitor treatment in pleural mesothelioma. This is the first case describing the use of F-18 fluorodeoxyglucose-positron emission tomography/computed tomography in the diagnostic work-up of a primary pericardial mesothelioma.     

Roles of F-18 FDG PET or PET/CT for the evaluation of gastrointestinal malignancies]

18F-FDG PET scan is an useful functional whole body imaging modality that images various types of malignancies with relative high sensitivity and specificity in a reasonably rapid time. It depicts a lesion based on abnormal glucose metabolism whereas CT detects malignant process mostly based on altered anatomy. In patients with gastric cancers, PET scan detects only less than 50% of early cancers and 62-98% of advanced cancers. For initial T staging, anatomical imaging with a high spatial resolution is essential. There are a few studies on the prognostic significance of FDG uptake with inconsistent results. In spite of low sensitivity for lymph node staging, the specificity of CT and PET scan are very high, and the specificity of PET scan tends to be higher than that of CT. Detection of distant metastases on PET scan is dependent on tumor histology, degree of FDG uptake in primary tumors, sites of distant metastases, etc. There are only a few data available for the evaluation of recurrence detection and treatment responses using FDG PET scan. FDG PET scan has been used in the preoperative staging of colorectal cancer with some promising results. It seems to be the most useful in restaging recurrent tumors and selecting those patients who would benefit from surgery. PET scan has a potential value in assessing treatment responses after various combination of treatments in patients with colorectal cancer.     

Diagnosis of Paget's disease of the pelvis using F-18 FDG PET/CT

Sclerotic lesions of the right iliac bone were discovered incidentally in a 52-year-old Korean woman. In this case, imaging of the right iliac bone showed intense osteoblastic activity on the bone scan and very mild F-18-fluoro-2-deoxyglucose (FDG) uptake on positron emission tomography (PET). Since Paget's disease is rare in Koreans, we aimed to rule out other bone diseases such as osteoblastic metastasis or osteomyelitis. These results allowed us to exclude chronic osteomyelitis or malignancy and clarify the diagnosis of Paget's disease of the iliac bone. This case illustrates how F-18 FDG PET/CT can be a useful tool in the differential diagnosis of various bone diseases.     

F-18FDGPET／CT在肺癌诊断中的应用价值

据世界卫生组织（World Health Organization．WHO）统计,每年肺癌的新增病例及死亡病例数在26种常见恶性肿瘤中居首位,且5年生存率低于15％。在我国,原发性肺部恶性肿瘤主要是原发性支气管肺癌,居肿瘤死亡率之首,即使早期非小细胞肺癌在手术后进行化疗,其5年生存率也仅为40％左右。     

Clinical implication of F-18 FDG PET/CT in patients with secondary hemophagocytic lymphohistiocytosis

The contribution that F-18 fluoro-2-deoxyglucose positron emission tomography/computed tomography (F-18 FDG) PET/CT makes to the diagnosis of malignancy in patients with hemophagocytic lymphohistiocytosis (HLH) is still uncertain. The aim of this study was to evaluate the diagnostic performance of F-18 FDG PET/CT for the detection of underlying malignancy, to investigate the correlation between PET and laboratory parameters, and to identify prognosis-related factors in patients with secondary HLH. We enrolled 14 patients who were diagnosed with HLH and referred for F-18 FDG PET/CT to exclude malignancy. The diagnostic performance of F-18 FDG PET/CT for malignancy detection was assessed. The correlations between PET and laboratory parameters were determined. The prognostic significance of the following factors was evaluated: PET and laboratory parameters, age in years, presence of underlying malignancy, and fever and splenomegaly. Six of the 14 patients had malignancies (four with lymphoma, one with multiple myeloma, and one with colonic malignancy). Sensitivity, specificity, and diagnostic accuracy of F-18 FDG PET/CT for malignancy detection were 83, 62.5, and 71.4 %, respectively. F-18 FDG uptake in the bone marrow and spleen was positively correlated with neutrophil count and C-reactive protein. All of the PET parameters, but none of the clinical or laboratory parameters, were significantly associated with patient outcome, as determined by univariate analysis. Given the small sample size, F-18 FDG PET/CT was useful for detecting underlying malignancy, and PET parameters correlated with laboratory parameters that reflected inflammatory status. F-18 FDG PET/CT might provide prognostic information for the management of patients with secondary HLH.     

Status of F-18 fluorodeoxyglucose uptake in normal and hibernating myocardium after glucose and insulin loading

Objective

F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has been increasingly used in myocardial viability imaging. In routine PET viability studies, oral glucose and intravenous insulin loading is commonly utilized. In an optimal study, glucose and insulin loading is expected to cause FDG uptake both in hibernating and normal myocardium. However, in routine studies it is not uncommon to see absent or reduced FDG uptake in normal myocardium. In this retrospective study we further analyzed our PET viability images to evaluate FDG uptake status in myocardium under the oral glucose and intravenous insulin loading protocol that we use in our hospital.

The utility of F-18 FDG PET/CT for diagnosis and response evaluation of hepatosplenic tuberculosis

A 77-year-old woman underwent F-18 FDG PET/CT for evaluation of fever focus. Diffuse and intense hepatosplenic uptake was noted and lymphoma or tuberculosis was proposed. Liver biopsy revealed chronic granulomatous inflammation with Langerhans-type giant cells and necrosis. A follow-up PET/CT after anti-tuberculosis treatment revealed that the hepatosplenic uptake had resolved.     

Diagnosis and monitoring of central nervous system involvement in systemic lupus erythematosus: value of F-18 fluorodeoxyglucose PET

OBJECTIVE: To investigate prospectively abnormalities of brain glucose utilisation in relation to major or minor neuropsychiatric symptoms in systemic lupus erythematosus (SLE). METHODS: Positron emission tomography (PET) using F-18-labelled fluorodeoxyglucose was performed in 28 patients with SLE. Patients were classified as having severe neuropsychiatric manifestations (seizures, focal neurological deficits, acute confusional states, mood disorders) (n=12), or mild neuropsychiatric manifestations (headache, reactive depression, cognitive dysfunction, anxiety disorders) (n=11) and five patients without signs of central nervous system (CNS) involvement. Ten clinically and neurologically healthy volunteers served as controls. In 26 patients magnetic resonance imaging (MRI) was performed and autoantibodies against CNS tissue, ribosomal P protein and cardiolipin were measured. In 14 patients follow up PET scans were performed after a mean (SD) period of 11.6 (9.5) months. RESULTS: PET scans showed hypometabolism in at least one brain region in all patients with severe or mild CNS symptoms (100%) as compared with patients without cerebral symptoms (40%) (p<0.0025). Parieto-occipital regions were most commonly affected (96%), followed by parietal regions (32%). In contrast, MRI images were abnormal in only 11 of 22 patients (50%) with neuropsychiatric symptoms and in one of four patients (25%) without symptoms. In 12 of 14 patients examined in follow up PET scans persistence, improvement or worsening of cerebral symptoms were associated with unchanged, decreased or increased brain hypometabolism, respectively. No significant correlation was found between PET or MRI findings and autoantibody profiles. CONCLUSIONS: PET imaging represents a sensitive tool to detect manifest or subclinical CNS involvement in SLE and PET findings correlate well with the clinical course of disease.     

Extensive Invasive Extramammary Paget Disease Evaluated by F-18 FDG PET/CT: A Case Report

Extramammary Paget disease (EMPD) is a rare cutaneous, intraepithelial adenocarcinoma. Because of its rarity, little is known about the value of fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in evaluating this disease. Our case report aims to increase current knowledge of FDG PET/CT in EMPD as a noninvasive imaging tool for assessing the extension of the disease and detecting distant metastases.We reported a 64-year-old Chinese man who presented with a slowly progressive, ill-margined erythematous lesion with a crusted, eroded, and scaly surface involving multiple sites of penis, scrotum, left pelvic wall, hip, groin, and thigh for >4 years, which became extensive in the past 1 year. He was referred for an FDG PET/CT examination to further evaluate the lesions. A following skin biopsy was performed to obtain a definitive histological diagnosis.FDG PET/CT imaging revealed mild FDG uptake at the extensive cutaneous lesion with subcutaneous invasion, involvement of lymph nodes, and multiple intense FDG-avid of skeletal metastases. According to the appearance of FDG PET/CT, a provisional diagnosis of advanced cutaneous malignancy was made. Histopathology findings indicated characteristic of EMPD. The patient was treated with radiation therapy and died from complications 2 months after the last dose of radiotherapy.Our case highlighted that a whole-body FDG PET/CT should be incorporated into the diagnostic algorithm of EMPD to give a comprehensive assessment of this disease.     

A pathophysiologic study of tako-tsubo cardiomyopathy with F-18 fluorodeoxyglucose positron emission tomography.

AIMS; Our study aims to investigate the pathophysiologic mechanism underlying tako-tsubo cardiomyopathy using F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET). METHODS AND RESULTS: Fifteen patients with tako-tsubo cardiomyopathy were enrolled in this study. Plasma catecholamines, cardiac troponin T (cTnT), and D-dimer were serially evaluated in all patients. Thallium-201 ((201)Tl) single-photon emission computed tomography (SPECT) and F-18 FDG PET were performed in 10 and eight patients, respectively. Emotional or physical stress occurred in 12 (80.0%) patients. ST-T segment abnormalities existed in all patients. Thirteen patients exhibited mildly elevated cTnT, although coronary angiography did not reveal significant stenosis in any patient. Endomyocardial biopsy specimens (n = 9) demonstrated contraction-band necrosis (n = 4) and mononuclear cell infiltration (n = 3). The levels of norepinephrine and epinephrine peaked on admission (744 +/- 452 and 140 +/- 166 pg/mL, respectively). There was severely reduced uptake at the apex on F-18 FDG PET image, despite slightly reduced uptake of (201)Tl. Elevation of D-dimer was observed in nine patients. CONCLUSION: The extent of metabolic defect involving apical akinetic area was more severe than perfusion abnormality. Our data suggest that sudden emotional or physical stress may cause a catecholamine-induced metabolic disorder in the myocardium, which is probably central to this syndrome.     

A pathophysiological study of tako-tsubo cardiomyopathy with F-18 fluorodeoxyglucose positron emission tomography.

An interesting observational study by Yoshida et al.¹ usingF-18 fluorodeoxyglucose positron emission tomography identifiedthat the extent of metabolic defect involving apical akinetic     

Serial F-18-FDG PET/CT distinguishes inflamed from stable plaque phenotypes in shear-stress induced murine atherosclerosis

Background

Detection of inflamed atherosclerotic plaques is of crucial importance. The carotid artery cuff-model in ApoE^−/− mice results in shear-stress induced atherosclerosis with inflamed plaques upstream (US) and ‘stable’ plaques downstream (DS) of the cuff. We evaluated the potential of F-18-FDG PET/CT to differentiate these plaque phenotypes.

Methods

A predefined cuff was implanted round the left (n = 23) or right (n = 12) common carotid artery (CCA) of 35 ApoE^−/− mice on a cholesterol-rich diet. Small animal F-18-FDG PET/CT was performed after 4, 6 and 8 weeks. F-18-FDG uptake was quantified US and DS of the cuff and on the contralateral CCA. Subsequently, regional F-18-FDG uptake was normalized by the contralateral CCA uptake to obtain plaque-to-background (P/B)-ratios. Thereafter, CCA were explanted and investigated by immunohistology.

Results

P/B-ratio in the US-plaques increased from 1.22 ± 0.23 at 4 weeks over 1.23 ± 0.32 at 6 weeks to 1.37 ± 0.56 (p = ns) at 8 weeks after cuff implantation (left and right side of cuff implantation considered together). Uptake in the DS-plaques remained stable (1.14 ± 0.23, 1.10 ± 0.26 and 1.11 ± 0.25; p = ns). Uptake in the US-plaques was significantly higher than in the DS-plaques (all p < 0.05). P/B-ratios correlated with plaque size, degree of stenosis and macrophage density in the plaques. Moreover, there was a correlation between plaque size and macrophage density in the plaque.

Conclusions

F-18-FDG-PET/CT distinguishes atherosclerotic plaques with an inflamed from those with a ‘stable’ phenotype in a mouse model of shear-stress induced atherosclerosis in vivo.     

Relation Between F-18 FDG Uptake of PET/CT and BRAFV600E Mutation in Papillary Thyroid Cancer

BRAFV600E mutation and F-18 fluorodeoxyglucose (FDG) uptake are potential prognostic factors of papillary thyroid cancer (PTC). This study was performed to investigate the relationship between the BRAFV600E mutation and F-18 FDG uptake in PTC.We retrospectively included 169 PTC patients who underwent F-18 FDG positron emission tomography/computed tomography (PET/CT) before thyroidectomy from May 2009 to August 2012. Subjects were classified into overt PTC (>1 cm, n = 76) and papillary thyroid microcarcinoma (PTMC, n = 93) groups. Univariate and multivariate analyses were performed to assess the relationship between maximum standardized uptake value (SUV_max) of the primary tumors and clinicopathologic variables.The BRAFV600E mutation was detected in 82.2% (139/169). In all subjects, the BRAFV600E mutation and tumor size were independently related to SUV_max by multivariate analysis (P = 0.048 and P < 0.001, respectively). SUV_max was significantly higher in tumors with the BRAFV600E mutation than in those with wild-type BRAF (9.4 ± 10.9 vs 5.0 ± 4.1, P < 0.001). Similarly, in overt PTC group, the BRAFV600E mutation and tumor size were independently correlated with SUV_max (P = 0.032 and P = 0.001, respectively). By contrast, in PTMC group, only tumor size was significantly associated with SUV_max (P = 0.010).The presence of the BRAFV600E mutation is independently associated with high F-18 FDG uptake on preoperative PET/CT in patients with overt PTC, but this relationship was not evident in PTMC. This study provides a better understanding of the relationship between F-18 FDG uptake and BRAFV600E mutation in patients with PTC.     

PET/CT imaging: effect of respiratory motion on apparent myocardial uptake.

BACKGROUND: Positron emission tomography (PET) attenuation correction (AC) using computed tomography (CT) can be affected by respiratory motion: hi-speed CT captures 1 point of the respiratory cycle while PET emission data averages many cycles. We quantified the changes in apparent myocardial uptake due to this respiratory-induced CT attenuation mismatch. METHODS: Twenty-two patients undergoing fluorine-18 fluorodeoxyglucose (FDG) PET/CT received 3 sequential CT scans at normal resting end-inspiration (CT(INSPIR)), ending expiration (CT(EXPIR)), and at midvolume between end-expiration and end-inspiration (CT(MIDVOL)). A pneumotachometer measured absolute changes in lung volume. Seven subjects also underwent a 3-minute transmission scan with a 68Ge rotating rod source (RRS). The PET emission data set was reconstructed up to 4 times using CT(EXPIR), CT(INSPIR), CT(MIDVOL), and RRS AC maps. Relative heart position and cardiac uptake was measured for each CT attenuation correction. RESULTS: Respiratory motion produced marked changes in global and regional myocardial uptake. Changes were large in the lateral and anterior regions at the lung-soft tissue interface (up to 30% using CT(INSPIR) compared to CT(EXPIR) for AC) and smaller in the septal region (10% or less). Data corrected with CT(EXPIR) agreed best with the RRS. CONCLUSION: Respiratory effects can introduce large inhomogeneities in apparent myocardial uptake when CT is used for attenuation correction.