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Sample records for f-18 fdg brain

  1. Quantification of F-18 FDG PET images in temporal lobe epilepsy patients using probabilistic brain atlas.

    PubMed

    Kang, K W; Lee, D S; Cho, J H; Lee, J S; Yeo, J S; Lee, S K; Chung, J K; Lee, M C

    2001-07-01

    A probabilistic atlas of the human brain (Statistical Probabilistic Anatomical Maps: SPAM) was developed by the international consortium for brain mapping (ICBM). It is a good frame for calculating volume of interest (VOI) in many fields of brain images. After calculating the counts in VOI using the product of probability of SPAM images and counts in FDG images, asymmetric indices (AI) were calculated and used for finding epileptogenic zones in mesial temporal lobe epilepsy (mTLE). FDG PET images from 18 surgically confirmed mTLE patients and 22 age-matched controls were spatially normalized to the average brain MRI template of ICBM. Counts from normalized PET images were multiplied with the probability of 12 VOIs from SPAM images in both temporal lobes. Finally AI were calculated on each pair of VOIs, and compared with visual assessment. If AI of mTLE patients were not within 2.9 standard deviation from those of normal control group (P < 0.008; Bonferroni correction for P < 0.05), epileptogenic zones were considered to be found successfully. The counts of VOIs in the normal control group were symmetric (AI < 4.3%, paired t test P > 0.05) except for those of the inferior temporal gyrus (P < 0.001). By AIs in six pairs of VOIs, PET in mTLE had deficit on one side (P < 0.05). Lateralization was correct in only 14/18 of patients by AI, but 17/18 were consistent with visual inspection. In three patients with normal AI, PET images were symmetric on visual inspection. The asymmetric indices obtained by taking the product of the statistical probability anatomical map and FDG PET, correlated well with visual assessment in mTLE patients. SPAM is useful for the quantification of VOIs in functional images.

  2. Can brain thallium 201 SPECT substitute for F-18-FDG PET in detecting recurrent brain tumor in the presence of radiation necrosis; correlation with biopsy/surgery results

    SciTech Connect

    Antar, M.A.; Barnett, G.H.; McIntyre, W.J.

    1994-05-01

    F-18-FDG PET man has been largely successful in differentiating between radiation necrosis and recurrent brain tumors. Because of the expense and unavailability of PET scanners in most clinical centers, Tl-201 SPECT scan may offer an alternative. Therefore, we have evaluated both techniques in 18 patients (13 men and 5 women) whose ages range from 28 to 74 year old. Eleven patients had glioblastoma multiformi and 4 patients high grade astrocytoma and 3 patient meningiosarcoma. All patients received radiation therapy (5500-6000 Rad) and 13 patients received also chemotherapy. PET scan was performed 40-60 min. after 5-10 mCi of F-18 FDG (i.v.) and SPECT 30 min. after 4.6 mCi of Tl-201 chloride (i.v.). Severe FDG hypometabolism was evident in the irradiated regions, in all patients. Evidence of tumor recurrence was seen in 15 patients by both FDG PET and Thallium 201 SPECT. The ratio of peak pixel uptake of suspected tumor to that of normal cortex for FDG ranged from 0.67 to 1.5 with a mean of 1.02. The ratio of peak pixel uptake of thallium 201 in the suspected lesion to that of the contralateral scalp area ranges from 0.8 to 1.9 with mean of 1.1. There was concordance between the findings of PET and SPECT in 16/18 patients. However, the volume of involvement differs in these patients; most likely secondary to different mechanisms of uptake and both studies may complement each other. Subsequent biopsy/surgery in 11 patients confirmed tumor recurrence in 10 out of 11 patients. The findings suggest that thallium 201 brain SPECT scan can provide similar (but not identical) information regarding brain tumor recurrence in these patients.

  3. Uterine Epithelioid Angiosarcoma on F-18 FDG PET/CT.

    PubMed

    Hwang, Jae Pil; Lim, Sang Moo

    2013-06-01

    Uterine epithelioid angiosarcoma can have conventional imaging characteristics similar to those of other uterine tumors, such as leiomyoma, leiomyosarcomas or hemangioendothelioma. Uterine epithelioid angiosarcoma exhibiting increased fluorine-18 fluorodeoxyglucose (F-18 FDG) activity can be misdiagnosed. A 61-year-old woman who was diagnosed with uterine epithelioid angiosarcoma underwent F-18 FDG positron emission tomography/computed tomography (PET/CT) as a part of the pretreatment work up for surgery. F-18 FDG PET/CT showed an intense F-18 FDG uptake in the uterus in addition to increased F-18 FDG uptake at the paraaortic and aortocaval lymph nodes. To our knowledge, this is the first case report of intense F-18 FDG uptake in uterine epithelioid angiosarcoma in Korea.

  4. Cerebral Toxoplasmosis in a Patient with AIDS on F-18 FDG PET/CT.

    PubMed

    Kim, Hae Won; Won, Kyoung Sook; Choi, Byung Wook; Zeon, Seok Kil

    2010-04-01

    The distinction between primary central nervous system (CNS) lymphoma and nonmalignant lesions due to opportunistic infections, in particular cerebral toxoplasmosis, is important because of the different treatments involved. A 32-year-old patient with AIDS was hospitalized for intermittent headaches. Brain magnetic resonance imaging (MRI) showed a small well-enhanced nodular lesion in the right frontal lobe. A fluorine-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET)/computed tomography (CT) scan showed moderate FDG uptake in the nodular lesion of the right frontal lobe. We present a case of cerebral toxoplasmosis in a patient with acquired immunodeficiency syndrome (AIDS) and the usefulness of F-18 FDG PET/CT in the differential diagnosis of the cerebral toxoplasmosis will be discussed.

  5. Solitary sternal metastasis from hepatocellular carcinoma detected by F-18 FDG PET/CT.

    PubMed

    Kamaleshwaran, Koramadai Karuppusamy; Kashyap, Raghava; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2013-01-01

    Fluorine-18 fluoro-deoxy-glucose positron emission tomography (F-18 FDG PET) is not sensitive modality for the diagnosis of primary hepatocellular carcinoma (HCC). However, FDG-PET imaging may be useful in the identification of extrahepatic metastases. We report an interesting image of HCC with solitary metastasis to sternum detected by F-18 FDG PET/CT.

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

    PubMed

    Kim, Jahae; Yoo, Su Woong; Kang, Sae-Ryung; Bom, Hee-Seung; Song, Ho-Chun; Min, Jung-Joon

    2014-04-01

    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.

  7. [The clinical value of F-18 FDG PET/CT in patients with secondary hemophagocytic syndrome].

    PubMed

    Wang, Xing-Bing; Zhu, Yun-Xia; Liu, Xin; Pan, Bo; Zhang, Liang; Han, Yong-Sheng; Cai, Xiao-Yan; Zhu, Wei-Bo; Wu, Jing-Sheng; Sun, Zi-Min

    2014-12-01

    The aim of this study was to investigate the role of F-18 fluoro-2-deoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in diagnosis and prognostic evaluation of secondary hemophagocytic syndrome (HPS). A total of 11 secondary HPS patients examined with 18F-FDG-PET/CT were retrospectively analyzed. The diagnostic value of F-18 FDG PET/CT for malignancy detection was assessed. The values of maximum standardized uptake value (SUV(max)) in spleen (SUVS(p)) and in bone marrow (SUVBM) were measured to analyze their relationship with various laboratorial parameters and clinical outcome of secondary HPS patients. The results showed that 4 out of the 11 patients had malignancies, the sensitivity, specificity and diagnostic accuracy of F-18 FDG PET/CT for malignancy detection were 100%, 66.7% and 75% respectively, the SUV(max) of spleen and bone marrow showed no significant correlation with laboratorial parameters, a maximum SUVS(p) of 3.10 and a maximum SUVBM of 3.47 were the optimal cutoffs for predicting patients' outcome, the increased uptake of F-18 FDG in the BM and spleen were significantly associated with shorter survival time according to univariate analysis. It is concluded that 18F-FDG PET/CT may especially play an important role in diagnosis and predicting outcome of secondary HPS for the small sample size.

  8. Renal Cell Carcinoma with Paraneoplastic Manifestations: Imaging with CT and F-18 FDG PET/CT.

    PubMed

    Nguyen, Ba D; Roarke, Michael C

    2007-01-01

    We present a case of renal cell carcinoma with prominent inflammatory and paraneoplastic manifestations. The initial CT detection of renal malignancy and subsequent post-therapeutic F-18 FDG PET/CT diagnosis of occult osseous metastasis were based on the patient's anemia, thrombocytosis and abnormally increased levels of serum C-reactive protein.

  9. Cholangiolocellular Carcinoma of the Liver Exhibiting High F-18 FDG Uptake.

    PubMed

    Mori, Naoko; Ichikawa, Tamaki; Hashimoto, Jun; Yamashita, Tomohiro; Yamada, Misuzu; Hirabayashi, Kenichi; Imai, Yutaka

    2016-06-20

    Cholangiolocellular carcinoma (CoCC) is a rare primary liver cancer. It is considered to originate from hepatic progenitor or stem cells. We report a rare case of a 74-year-old male with CoCC of the liver and duodenal gastrointestinal stromal tumor (GIST). Both tumors manifested tracer uptakes on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT); however, the uptake in hepatic tumor was extremely higher than that in the duodenal tumor. This finding was helpful to exclude the metastasis of GIST.

  10. Benign Schwannoma Mimicking Metastatic Lesion on F-18 FDG PET/CT in Differentiated Thyroid Cancer.

    PubMed

    Kang, Sungmin

    2013-06-01

    We report a case of benign schwannoma mimicking metastatic carcinoma. A 55-year-old female with papillary thyroid carcinoma underwent total thyroidectomy. F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) demonstrated a focal hypermetabolic lesion with maximum standardized uptake value (SUVmax) 5.3 at the right chest wall. Conventional chest CT demonstrated a 5.4 cm ovoid mass lesion between the intercostal muscles and liver. Pathology revealed a schwannoma by tumor excision. This case demonstrates that benign schwannoma may demonstrate FDG uptake mimicking metastatic carcinoma.

  11. Rapidly growing complex fibroadenoma with surrounding ductal hyperplasia mimics breast malignancy on serial F-18 FDG PET/CT imaging.

    PubMed

    Makis, William; Ciarallo, Anthony; Hickeson, Marc; Derbekyan, Vilma

    2011-07-01

    A 30-year-old woman was referred for an F-18 fluorodeoxyglucose (FDG) PET/CT to rule out lymphoma, and was found to have an incidental FDG-avid right breast nodule that grew significantly in size and FDG uptake on a subsequent scan, raising suspicion of a growing breast malignancy. Histologic evaluation showed a complex fibroadenoma with adenosis and surrounding ductal hyperplasia. Although variable F-18 FDG uptake in fibroadenomas has been described, a distinction between simple and complex fibroadenomas has not been made in the PET literature, even though complex fibroadenomas have a higher propensity to develop into malignancies. This case shows that a rapidly growing complex fibroadenoma can mimic a breast malignancy on serial F-18 FDG PET/CT scans, showing significant increase in both size and FDG-avidity on follow-up studies.

  12. Isolated thymic Langerhans cell histiocytosis discovered on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT).

    PubMed

    Turpin, Sophie; Carret, Anne-Sophie; Dubois, Josée; Buteau, Chantal; Patey, Natalie

    2015-11-01

    The thymic infiltration in young patients with multisystemic Langerhans cell histiocytosis and its radiologic features are well known. However, isolated thymic disease has seldom been reported in the literature. We report the case of a 10-month-old child admitted for fever of unknown origin. Whole-body F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) was performed to identify a focus of infection. It demonstrated an unusual aspect of the thymus, which led to further investigation and revealed isolated infiltration of the thymus by Langerhans cell histiocytosis. The patient was treated accordingly and is now disease free. As evaluation of Langerhans cell histiocytosis patients with F-18 FDG PET/CT is becoming more frequent, it is important to be aware of the scintigraphical characteristics of thymic Langerhans cell histiocytosis.

  13. Muscular Sarcoidosis Detected by F-18 FDG PET/CT in a Hypercalcemic Patient

    PubMed Central

    Han, Eun Ji; Jang, Yi Sun; Lee, In Suk; Lee, Jong Min; Kang, Siwon

    2013-01-01

    Sarcoidosis is a systemic granulomatous disease of unknown etiology that involves many organs, occasionally mimicking malignancy. We herein report a 50-yr-old woman of muscular sarcoidosis of chronic myopathic type, manifested by hypercalcemia and muscle wasting. Besides insignificant hilar lymphadenopathy, her sarcoidosis was confined to generalized atrophic muscles and therefore, F-18 FDG PET/CT alone among conventional imaging studies provided diagnostic clues for the non-parathyroid-related hypercalcemia. On follow-up PET/CT during low-dose steroid treatment, FDG uptake in the muscles disappeared whereas that in the hilar lymph nodes remained. PET/CT may be useful in the evaluation of unexpected disease extent and monitoring treatment response in suspected or known sarcoidosis patients. PMID:24015050

  14. Current concepts in F18 FDG PET/CT-based radiation therapy planning for lung cancer.

    PubMed

    Lee, Percy; Kupelian, Patrick; Czernin, Johannes; Ghosh, Partha

    2012-01-01

    Radiation therapy is an important component of cancer therapy for early stage as well as locally advanced lung cancer. The use of F18 FDG PET/CT has come to the forefront of lung cancer staging and overall treatment decision-making. FDG PET/CT parameters such as standard uptake value and metabolic tumor volume provide important prognostic and predictive information in lung cancer. Importantly, FDG PET/CT for radiation planning has added biological information in defining the gross tumor volume as well as involved nodal disease. For example, accurate target delineation between tumor and atelectasis is facilitated by utilizing PET and CT imaging. Furthermore, there has been meaningful progress in incorporating metabolic information from FDG PET/CT imaging in radiation treatment planning strategies such as radiation dose escalation based on standard uptake value thresholds as well as using respiratory-gated PET and CT planning for improved target delineation of moving targets. In addition, PET/CT-based follow-up after radiation therapy has provided the possibility of early detection of local as well as distant recurrences after treatment. More research is needed to incorporate other biomarkers such as proliferative and hypoxia biomarkers in PET as well as integrating metabolic information in adaptive, patient-centered, tailored radiation therapy.

  15. Diagnostic performance of PET/CT with tracers other than F-18-FDG in oncology: an evidence-based review.

    PubMed

    Treglia, G; Sadeghi, R; Del Sole, A; Giovanella, L

    2014-09-01

    Fluorine-18-fluorodeoxyglucose (F-18-FDG) is the most used positron emitter radiopharmaceutical worldwide. This glucose analogue allows to study the glucose metabolism which is often increased in many tumors. Nowadays the diagnostic performance of positron emission tomography/computed tomography (PET/CT) using F-18-FDG in different tumors is well known. On the other hand, to date, there is an increasing interest for the use of PET tracers other than F-18-FDG in oncology, because they allow to study different metabolic pathways or receptor expression. The aim of this review is to summarize the scientific literature about the diagnostic performance of PET/CT using tracers other than F-18-FDG in oncology through an evidence-based approach. In particular, the results of meta-analyses (representing the highest level of evidence) on the diagnostic performance of PET tracers other than F-18-FDG in different tumors are described. Furthermore, recommendations for the use of different PET tracers in oncology are provided based on existing literature data.

  16. A Rationale for the Use of F18-FDG PET/CT in Fever and Inflammation of Unknown Origin

    PubMed Central

    Balink, H.; Verberne, H. J.; Bennink, R. J.; van Eck-Smit, B. L. F.

    2012-01-01

    This review focuses on the diagnostic value of hybrid F18-FDG Positron Emission Tomography/Computerized tomography (PET/CT) in fever of unknown origin (FUO) and inflammation of unknown origin (IUO). Due to the wide range of possible causes both FUO and IUO remain a clinical challenge for both patients and physicians. In addition, the aetiology of IUO shows the same variation in diseases as the FUO spectrum and probably requires the same diagnostic approach as FUO. There are numerous historically used diagnostic approaches incorporating invasive and non-invasive, and imaging techniques, all with relative high specificity but limited sensitivity. This hampers the generalization of these diagnostic approaches. However, recently published reports show that F18-FDG PET/CT in FUO and IUO has a high sensitivity and a relative non-specificity for malignancy, infection and inflammation. This makes F18-FDG PET/CT an ideal diagnostic tool to start the diagnostic process and to guide subsequent focused diagnostic approaches with higher specificity. In addition, F18-FDG PET/CT has a relative high negative predictive value. Therefore F18 FDG PET/CT should be incorporated in the routine diagnostic work-up of patients with FUO and IUO, preferably at an early stage in the diagnostic process. PMID:23316356

  17. A Study on the Basic Criteria for Selecting Heterogeneity Parameters of F18-FDG PET Images

    PubMed Central

    Forgacs, Attila; Pall Jonsson, Hermann; Dahlbom, Magnus; Daver, Freddie; D. DiFranco, Matthew; Opposits, Gabor; K. Krizsan, Aron; Garai, Ildiko; Czernin, Johannes; Varga, Jozsef; Tron, Lajos; Balkay, Laszlo

    2016-01-01

    Textural analysis might give new insights into the quantitative characterization of metabolically active tumors. More than thirty textural parameters have been investigated in former F18-FDG studies already. The purpose of the paper is to declare basic requirements as a selection strategy to identify the most appropriate heterogeneity parameters to measure textural features. Our predefined requirements were: a reliable heterogeneity parameter has to be volume independent, reproducible, and suitable for expressing quantitatively the degree of heterogeneity. Based on this criteria, we compared various suggested measures of homogeneity. A homogeneous cylindrical phantom was measured on three different PET/CT scanners using the commonly used protocol. In addition, a custom-made inhomogeneous tumor insert placed into the NEMA image quality phantom was imaged with a set of acquisition times and several different reconstruction protocols. PET data of 65 patients with proven lung lesions were retrospectively analyzed as well. Four heterogeneity parameters out of 27 were found as the most attractive ones to characterize the textural properties of metabolically active tumors in FDG PET images. These four parameters included Entropy, Contrast, Correlation, and Coefficient of Variation. These parameters were independent of delineated tumor volume (bigger than 25–30 ml), provided reproducible values (relative standard deviation< 10%), and showed high sensitivity to changes in heterogeneity. Phantom measurements are a viable way to test the reliability of heterogeneity parameters that would be of interest to nuclear imaging clinicians. PMID:27736888

  18. A Study on the Basic Criteria for Selecting Heterogeneity Parameters of F18-FDG PET Images.

    PubMed

    Forgacs, Attila; Pall Jonsson, Hermann; Dahlbom, Magnus; Daver, Freddie; D DiFranco, Matthew; Opposits, Gabor; K Krizsan, Aron; Garai, Ildiko; Czernin, Johannes; Varga, Jozsef; Tron, Lajos; Balkay, Laszlo

    2016-01-01

    Textural analysis might give new insights into the quantitative characterization of metabolically active tumors. More than thirty textural parameters have been investigated in former F18-FDG studies already. The purpose of the paper is to declare basic requirements as a selection strategy to identify the most appropriate heterogeneity parameters to measure textural features. Our predefined requirements were: a reliable heterogeneity parameter has to be volume independent, reproducible, and suitable for expressing quantitatively the degree of heterogeneity. Based on this criteria, we compared various suggested measures of homogeneity. A homogeneous cylindrical phantom was measured on three different PET/CT scanners using the commonly used protocol. In addition, a custom-made inhomogeneous tumor insert placed into the NEMA image quality phantom was imaged with a set of acquisition times and several different reconstruction protocols. PET data of 65 patients with proven lung lesions were retrospectively analyzed as well. Four heterogeneity parameters out of 27 were found as the most attractive ones to characterize the textural properties of metabolically active tumors in FDG PET images. These four parameters included Entropy, Contrast, Correlation, and Coefficient of Variation. These parameters were independent of delineated tumor volume (bigger than 25-30 ml), provided reproducible values (relative standard deviation< 10%), and showed high sensitivity to changes in heterogeneity. Phantom measurements are a viable way to test the reliability of heterogeneity parameters that would be of interest to nuclear imaging clinicians.

  19. Usefulness of F-18 FDG PET/CT in subcutaneous panniculitis-like T cell lymphoma: disease extent and treatment response evaluation.

    PubMed

    Kim, Jin-Suk; Jeong, Young Jin; Sohn, Myung-Hee; Jeong, Hwan-Jeong; Lim, Seok Tae; Kim, Dong Wook; Kwak, Jae-Yong; Yim, Chang-Yeol

    2012-12-01

    BACKGROUND.: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cutaneous lymphomas, accounting for less than 1% of cases of non-Hodgkin's lymphoma. Fluorine-18 fluorodeoxyglucose (F-18 FDG) positron-emission tomography/computed tomography (PET/CT) findings of SPTCL before and after treatment were rarely reported. CASE REPORT.: We report a case of SPTCL in which F-18 FDG PET/CT showed increased FDG accumulations in numerous subcutaneous nodules without extracutaneous disease. Contrast-enhanced CT during F-18 FDG PET/CT showed multiple minimally enhancing nodules with an infiltrative pattern in the subcutaneous layer throughout the body. Follow-up F-18 FDG PET/CT after three cycles of CHOP chemotherapy showed a complete metabolic remission of the lesions. CONCLUSIONS.: F-18 FDG PET/CT is suggested to be useful in assessing the disease activity, extent and treatment response in SPTCL.

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

    PubMed

    Yoon, Seokho; An, Young-Sil; Lee, Su Jin; So, Eu Young; Kim, Jang-Hee; Chung, Yoon-Sok; Yoon, Joon-Kee

    2015-12-01

    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 (SUVmax) 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 SUVmax by multivariate analysis (P = 0.048 and P < 0.001, respectively). SUVmax 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 SUVmax (P = 0.032 and P = 0.001, respectively). By contrast, in PTMC group, only tumor size was significantly associated with SUVmax (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.

  1. Very low-dose adult whole-body tumor imaging with F-18 FDG PET/CT

    NASA Astrophysics Data System (ADS)

    Krol, Andrzej; Naveed, Muhammad; McGrath, Mary; Lisi, Michele; Lavalley, Cathy; Feiglin, David

    2015-03-01

    The aim of this study was to evaluate if effective radiation dose due to PET component in adult whole-body tumor imaging with time-of-flight F-18 FDG PET/CT could be significantly reduced. We retrospectively analyzed data for 10 patients with the body mass index ranging from 25 to 50. We simulated F-18 FDG dose reduction to 25% of the ACR recommended dose via reconstruction of simulated shorter acquisition time per bed position scans from the acquired list data. F-18 FDG whole-body scans were reconstructed using time-of-flight OSEM algorithm and advanced system modeling. Two groups of images were obtained: group A with a standard dose of F-18 FDG and standard reconstruction parameters and group B with simulated 25% dose and modified reconstruction parameters, respectively. Three nuclear medicine physicians blinded to the simulated activity independently reviewed the images and compared diagnostic quality of images. Based on the input from the physicians, we selected optimal modified reconstruction parameters for group B. In so obtained images, all the lesions observed in the group A were visible in the group B. The tumor SUV values were different in the group A, as compared to group B, respectively. However, no significant differences were reported in the final interpretation of the images from A and B groups. In conclusion, for a small number of patients, we have demonstrated that F-18 FDG dose reduction to 25% of the ACR recommended dose, accompanied by appropriate modification of the reconstruction parameters provided adequate diagnostic quality of PET images acquired on time-of-flight PET/CT.

  2. MO-G-17A-07: Improved Image Quality in Brain F-18 FDG PET Using Penalized-Likelihood Image Reconstruction Via a Generalized Preconditioned Alternating Projection Algorithm: The First Patient Results

    SciTech Connect

    Schmidtlein, CR; Beattie, B; Humm, J; Li, S; Wu, Z; Xu, Y; Zhang, J; Shen, L; Vogelsang, L; Feiglin, D; Krol, A

    2014-06-15

    Purpose: To investigate the performance of a new penalized-likelihood PET image reconstruction algorithm using the 1{sub 1}-norm total-variation (TV) sum of the 1st through 4th-order gradients as the penalty. Simulated and brain patient data sets were analyzed. Methods: This work represents an extension of the preconditioned alternating projection algorithm (PAPA) for emission-computed tomography. In this new generalized algorithm (GPAPA), the penalty term is expanded to allow multiple components, in this case the sum of the 1st to 4th order gradients, to reduce artificial piece-wise constant regions (“staircase” artifacts typical for TV) seen in PAPA images penalized with only the 1st order gradient. Simulated data were used to test for “staircase” artifacts and to optimize the penalty hyper-parameter in the root-mean-squared error (RMSE) sense. Patient FDG brain scans were acquired on a GE D690 PET/CT (370 MBq at 1-hour post-injection for 10 minutes) in time-of-flight mode and in all cases were reconstructed using resolution recovery projectors. GPAPA images were compared PAPA and RMSE-optimally filtered OSEM (fully converged) in simulations and to clinical OSEM reconstructions (3 iterations, 32 subsets) with 2.6 mm XYGaussian and standard 3-point axial smoothing post-filters. Results: The results from the simulated data show a significant reduction in the 'staircase' artifact for GPAPA compared to PAPA and lower RMSE (up to 35%) compared to optimally filtered OSEM. A simple power-law relationship between the RMSE-optimal hyper-parameters and the noise equivalent counts (NEC) per voxel is revealed. Qualitatively, the patient images appear much sharper and with less noise than standard clinical images. The convergence rate is similar to OSEM. Conclusions: GPAPA reconstructions using the 1{sub 1}-norm total-variation sum of the 1st through 4th-order gradients as the penalty show great promise for the improvement of image quality over that currently achieved

  3. Radiation assessment to paediatric with F-18-FDG undergo whole-body PET/CT examination

    NASA Astrophysics Data System (ADS)

    Dhalisa, H.; Mohamad, A. S.; Rafidah, Z.

    2016-01-01

    This study was carried out on wholebody radiation dose assessment to paediatrics patient who undergo PET/CT scanner at Institut Kanser Negara. Consist of 68 patients with varies of malignancies and epilepsy disease case covering age between 2 years to 12 years old. This is a retrospective study from 2010-2014. The use of PET/CT scanner as an advanced tool has been proven to give an extra radiation dose to the patient. It is because of the radiation exposure from the combination of both CT and PET scans rather than a single CT or PET scan. Furthermore, a study on radiation dose to paediatric patient undergoing PET/CT is rare in Malaysia. So, the aim of this study is to estimate the wholebody effective dose to paediatric patient in Malaysia. Effective dose from PET scan was calculated based on the activity of F18 FDG and dose coefficient reported in International Commission on Radiological Protection (ICRP) Publication 106. Effective dose from CT was determined using k coefficient as reported in ICRP publication 102 and Dose Length Product (DLP) value. The average effective dose from PET and CT were found to be 7.05mSv and 5.77mSv respectively. The mean wholebody effective dose received by a patient with combined PETCT examination was 12.78mSv. These results could be used as reference for dosimetry of a patient undergoing PETCT examination in Malaysia.

  4. Radiation assessment to paediatric with F-18-FDG undergo whole-body PET/CT examination

    SciTech Connect

    Dhalisa, H. Rafidah, Z.; Mohamad, A. S.

    2016-01-22

    This study was carried out on wholebody radiation dose assessment to paediatrics patient who undergo PET/CT scanner at Institut Kanser Negara. Consist of 68 patients with varies of malignancies and epilepsy disease case covering age between 2 years to 12 years old. This is a retrospective study from 2010-2014. The use of PET/CT scanner as an advanced tool has been proven to give an extra radiation dose to the patient. It is because of the radiation exposure from the combination of both CT and PET scans rather than a single CT or PET scan. Furthermore, a study on radiation dose to paediatric patient undergoing PET/CT is rare in Malaysia. So, the aim of this study is to estimate the wholebody effective dose to paediatric patient in Malaysia. Effective dose from PET scan was calculated based on the activity of F18 FDG and dose coefficient reported in International Commission on Radiological Protection (ICRP) Publication 106. Effective dose from CT was determined using k coefficient as reported in ICRP publication 102 and Dose Length Product (DLP) value. The average effective dose from PET and CT were found to be 7.05mSv and 5.77mSv respectively. The mean wholebody effective dose received by a patient with combined PETCT examination was 12.78mSv. These results could be used as reference for dosimetry of a patient undergoing PETCT examination in Malaysia.

  5. Correlation of Glut-1 and Glut-3 expression with F-18 FDG uptake in pulmonary inflammatory lesions.

    PubMed

    Wang, Zhen Guang; Yu, Ming Ming; Han, Yu; Wu, Feng Yu; Yang, Guang Jie; Li, Da Cheng; Liu, Si Min

    2016-11-01

    The aim of the study was to investigate the correlation of glucose transporter-1 (Glut-1) and glucose transporter-3 (Glut-3) expression with F-18 FDG uptake in pulmonary inflammatory lesions.Twenty-two patients with pulmonary inflammatory lesions underwent positron emission tomography/computed tomography (PET/CT) examination preoperatively, and Glut-1 and Glut-3 expression were detected by immunohistochemistry in these lesions. Correlations of Glut-1 and Glut-3 with F-FDG uptake were assessed using Spearman's rank correlation test.The maximum standardized uptake value (SUVmax) of pulmonary inflammatory lesions in 22 patients was 0.50 to 7.50, with a mean value of 3.66 ± 1.62. Immunohistochemical staining scores of Glut-1 and Glut-3 were 2.18 ± 0.96 and 2.82 ± 1.37, respectively. The expression of Glut-1 and Glut-3 was positively correlated with F-18 FDG uptake. Glut-3 expression was evidently higher than Glut-1 expression in 22 patients.Glut-1 and Glut-3 expressions are high in pulmonary inflammatory lesions, and Glut-3 plays a more important role in F-18 FDG uptake in pulmonary inflammatory lesions.

  6. F18-FDG-PET/CT for evaluation of intraductal papillary mucinous neoplasms (IPMN): a review of the literature.

    PubMed

    Bertagna, Francesco; Treglia, Giorgio; Baiocchi, Gian Luca; Giubbini, Raffaele

    2013-04-01

    Intraductal papillary mucinous neoplasms (IPMN) are intraductal mucin-producing neoplasms with tall columnar, mucin-containing epithelium, with or without papillary projections, involving the main pancreatic duct and/or major side branches. They account for approximately 25 % of all cystic neoplasms and can be subdivided into benign lesions, borderline lesions, and carcinoma. In this clinical scenario accurate preoperative diagnosis can eliminate unnecessary surgery, which is risky and potentially harmful, yet enable effective selection of patients who are candidates for surgery. In this review we try to provide a complete evaluation of the use of F18-FDG-PET/CT for diagnosis of this neoplasm on the basis of published papers. F18-FDG-PET/CT seems to be an useful technique for preoperative work-up of patients with suspected IPMN and is an improvement over conventional imaging in distinguishing benign from malignant lesions, especially for selecting patients for surgical treatment or for long-term follow-up.

  7. Differentiation of thoracic tumors from post-treatment changes using PET with F-18 FDG and C-11 methionine

    SciTech Connect

    Kim, E.E.; Garcia, J.R.; Wong, F.C.L.

    1994-05-01

    This study was undertaken to differentiate active residual or recurrent thoracic tumors from various post-treatment changes by utilizing PET with F-18 FDG and also to compare F-18 FDG and C-11 methionine (Met) in diagnostic accuracy. We have prospectively evaluated 77 FDG-PET studies in 61 patients with histologically proven lung (37) and other thoracic (24) malignant tumors. Eleven Met-PET studies were obtained in 10 patients (three lung, seven other cancers). All patients received surgery, radiation, and/or chemotherapy, and their routine follow-up radiographic exam including CT showed suspected recurrent or residual tumors. PET studies were performed using Posicam scanner (Positron Co.) transaxial as well as reconstructed coronal or sagittal images were obtained after injection of 5-10 mCi F-18 FDG or 15-20 mCi C-11 Met following at least four hour fasting and attenuating correction. All PET images were visually inspected and correlated with radiographic studies. Standard uptake values (SUVs) were generated and compared on serial studies. Fifty-one studies had histologic correlation and all patients had at least six month follow-ups. Sensitivity, specificity and accuracy for diagnosing active thoracic tumors with FDG-PET scans were 100% (52/52), 88% (22/25) and 96% (74/77), respectively. They were 100% (7/7), 100% (4/4) and 100% (11/11), respectively with Met-PET in selected patients. Three false positive (FP) FDG cases showed active inflammation histologically. SUVs of FDG-PET were 6.5{plus_minus}2.9 for true positives and 1.4{plus_minus}1.3 for true negatives, respectively. SUVs of Met-PET were 4.3{plus_minus}2.3 for TP and 1.2{plus_minus}0.5 for TN, respectively. In conclusion, PET with FDG or Met is useful in diagnosing active thoracic tumors after various treatments, and FDG showed greater SUV than Met.

  8. Prognostic value of pre-treatment F-18-FDG PET-CT in patients with hepatocellular carcinoma undergoing radioembolization

    PubMed Central

    Abuodeh, Yazan; Naghavi, Arash O; Ahmed, Kamran A; Venkat, Puja S; Kim, Youngchul; Kis, Bela; Choi, Junsung; Biebel, Benjamin; Sweeney, Jennifer; Anaya, Daniel A; Kim, Richard; Malafa, Mokenge; Frakes, Jessica M; Hoffe, Sarah E; El-Haddad, Ghassan

    2016-01-01

    AIM To evaluate the value of pre-treatment 18F-FDG PET/CT in patients with HCC following liver radioembolization. METHODS We identified 34 patients with HCC who underwent an FDG PET/CT scan prior to hepatic radioembolization at our institution between 2009 and 2013. Patients were seen in clinic one month after radioembolization and then at 2-3 mo intervals. We assessed the influence of FDG tumor uptake on outcomes including local liver control (LLC), distant liver control (DLC), time to distant metastases (DM), progression free survival (PFS) and overall survival (OS). RESULTS The majority of patients were males (n = 25, 74%), and had Child Pugh Class A (n = 31, 91%), with a median age of 68 years (46-84 years). FDG-avid disease was found in 19 (56%) patients with SUVmax ranging from 3 to 20. Female patients were more likely to have an FDG-avid HCC (P = 0.02). Median follow up of patients following radioembolization was 12 months (1.2-62.8 mo). FDG-avid disease was associated with a decreased 1 year LLC, DLC, DM and PFS (P < 0.05). Using multivariate analysis, FDG avidity predicted for LLC, DLC, and PFS (all P < 0.05). CONCLUSION In this retrospective study, pre-treatment HCC FDG-avidity was found to be associated with worse LLC, DLC, and PFS following radioembolization. Larger studies are needed to validate our initial findings to assess the role of F-18-FDG PET/CT scans as biomarker for patients with HCC following radioembolization. PMID:28058021

  9. Response Assessment and Prediction in Esophageal Cancer Patients via F-18 FDG PET/CT Scans

    NASA Astrophysics Data System (ADS)

    Higgins, Kyle J.

    Purpose: The purpose of this study is to utilize F-18 FDG PET/CT scans to determine an indicator for the response of esophageal cancer patients during radiation therapy. There is a need for such an indicator since local failures are quite common in esophageal cancer patients despite modern treatment techniques. If an indicator is found, a patient's treatment strategy may be altered to possibly improve the outcome. This is investigated with various standard uptake volume (SUV) metrics along with image texture features. The metrics and features showing the most promise and indicating response are used in logistic regression analysis to find an equation for the prediction of response. Materials and Methods: 28 patients underwent F-18 FDG PET/CT scans prior to the start of radiation therapy (RT). A second PET/CT scan was administered following the delivery of ~32 Gray (Gy) of dose. A physician contoured gross tumor volume (GTV) was used to delineate a PET based GTV (GTV-pre-PET) based on a threshold of >40% and >20% of the maximum SUV value in the GTV. Deformable registration was used in VelocityAI software to register the pre-treatment and intra-treatment CT scans so that the GTV-pre-PET contours could be transferred from the pre to intra scans (GTV-intra-PET). The fractional decrease in the maximum, mean, volume to the highest intensity 10%-90%, and combination SUV metrics of the significant previous SUV metrics were compared to post-treatment pathologic response for an indication of response. Next for the >40% threshold, texture features based on a neighborhood gray-tone dimension matrix (NGTDM) were analyzed. The fractional decrease in coarseness, contrast, busyness, complexity, and texture strength were compared to the pathologic response of the patients. From these previous two types of analysis, SUV and texture features, the two most significant results were used in logistic regression analysis to find an equation to predict the probability of a non

  10. Is there any complimentary role of F-18 NaF PET/CT in detecting of osseous involvement of multiple myeloma? A comparative study for F-18 FDG PET/CT and F-18 FDG NaF PET/CT.

    PubMed

    Ak, İlknur; Onner, Hasan; Akay, Olga Meltem

    2015-09-01

    Multiple myeloma (MM) is a disease characterized by a monoclonal plasma cell population in the bone marrow whereby osseous involvement is a predominant feature. The aim of this prospective study was to investigate the combined use of F-18 FDG and F-18 NaF PET/CT in the skeletal assessment of patients with MM and to compare the efficacy of these two PET tracers regarding detection of myeloma-indicative osseous lesions. A total of 26 patients (14 females and 12 males, mean age 61.8 ± 1.8 years (range 40-81 years)) with MM diagnosed according to standard criteria. All patients underwent both F-18 FDG PET/CT and F-18 NaF PET/CT scans within 1 week after the completion of the usual staging workup for MM. In total, approximately 128 focal F-18 FDG avid skeletal lesions were detected; the stage I (n = 5) patients had 10 bone lesions, the stage II (n = 11) patients had 43 lesions, and the stage III (n = 10) patients demonstrated 75 focal bone lesions. F-18 NaF PET/CTs demonstrated fewer myeloma indicative lesions than F-18 FDG PET/CTs. Totally, 57 focal bone lesions were detected with whole body F-18 NaF PET/CT (mean 2.19 ± 0.34, between 1 and 9 lesions); the five stage I patients had 6 bone lesions, the 11 stage II pts had 18 lesions, and the ten stage III patients demonstrated 33 focal bone lesions. On the other hand, F-18 NaF PET/CT demonstrated additional 135 bone lesions defined as rib fractures and other findings due to degenerative changes. In conclusion, our study implies that F-18 NaF PET/CT scan did not actually aid for assessing the myelomatous bone lesions in patients with MM. Therefore, a complementary F-18 NaF PET/CT may be an accurate modality for detecting of bone fracture in patients with MM.

  11. Extensive invasive extramammary Paget disease evaluated by F-18 FDG PET/CT: a case report.

    PubMed

    Li, Zu-Gui; Qin, Xiao-Jing

    2015-01-01

    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.

  12. Pulmonary artery sarcoma detected on F-18 FDG PET/CT as origin of multiple spinal metastases.

    PubMed

    Chun, In Kook; Eo, Jae Seon; Paeng, Jin Chul; Kim, Dong Wan; Chung, June-Key; Lee, Dong Soo

    2011-08-01

    A 67-year-old man with back pain was diagnosed as having multiple spinal metastases on MRI. On CT scan, only a filling defect in the right pulmonary artery was observed and suspected as venous thromboembolism. On F-18 fluorodeoxyglucose (FDG) PET/CT, intense hypermetabolism was observed in the right pulmonary artery in addition to the metastatic spine lesions. Biopsy confirmed the lesion as a primary pulmonary artery sarcoma (PAS), and the spine lesions as metastases of PAS. Although PAS is rare and its bone metastasis presenting initial symptom is extremely rare, FDG PET/CT is an effective diagnostic modality for PAS, not only in discrimination from venous thromboembolism, but also in workup of metastatic origin.

  13. Usefulness of F-18 FDG PET/CT in a case of Kaposi sarcoma with an unexpected bone lesion.

    PubMed

    Morooka, Miyako; Ito, Kimiteru; Kubota, Kazuo; Yanagisawa, Kunio; Teruya, Katsuji; Hasuo, Kahehiro; Shida, Yoshitaka; Minamimoto, Rhogo; Kikuchi, Yoshimi; Oka, Shinichi

    2011-03-01

    Bone lesions of Kaposi sarcoma are rare. A 56-year-old man who was HIV positive and was diagnosed with Kaposi sarcoma on the basis of the results of a biopsy of skin lesions, underwent F-18 FDG PET/CT scan for detecting Kaposi sarcoma lesions and other AIDS-related diseases. An abnormal uptake was observed in the lumbar spine. MRI showed a diffuse enhanced spine lesion, and Ga-67 and ²⁰¹Tl scanning were negative. As a result, the lesion was considered to be a Kaposi sarcoma, and the shrinkage of the lesion was noted after the therapy for Kaposi sarcoma.

  14. Predictive value of intratumoral heterogeneity of F-18 FDG uptake for characterization of thyroid nodules according to Bethesda categories of fine needle aspiration biopsy results.

    PubMed

    Kim, Seong-Jang; Chang, Samuel

    2015-12-01

    The current study was aimed to investigate the clinical value of intratumoral heterogeneity of F-18 FDG uptake for characterization of thyroid nodule (TN) with inconclusive fine-needle aspiration biopsy (FNAB) results. The current study enrolled 200 patients who showed F-18 FDG incidentaloma and were performed FNAB. The intratumoral heterogeneity of F-18 FDG uptake was represented as the heterogeneity factor (HF), defined as the derivative (dV/dT) of a volume-threshold function for a primary tumor. The diagnostic and predictive values of HF and F-18 FDG PET/CT parameters were evaluated for characterization of inconclusive FNAB results. Among F-18 FDG PET/CT parameters, SUVmax, MTV, and TLG of malignant group were statistically higher than those of Bethesda category of suspicious malignant group. However, HF values were not statistically different between the groups of Bethesda categories (Kruskal-Wallis statistics, 9.924; p = 0.0774). In ROC analysis, when HF > 2.751 was used as cut-off value, the sensitivity and specificity for prediction of malignant TN were 100 % (95 % CI 69.2-100 %) and 60 % (95 % CI 42.1-76.1 %), respectively. The AUC was 0.826 (95 % CI 0.684-0.922) and standard error was 0.0648 (p < 0.0001). In conclusion, the intratumoral heterogeneity of F-18 FDG uptake represented by HF could be a predictor for characterization of TN with inconclusive FNAB results. Additional large population-based prospective studies are needed to validate the diagnostic utility of HF of F-18 FDG PET/CT.

  15. 2-Deoxy-2[F-18]FDG-PET for Detection of Recurrent Laryngeal Carcinoma after Radiotherapy: Interobserver Variability in Reporting

    PubMed Central

    van der Putten, L.; Hoekstra, O. S.; Kuik, D. J.; Comans, E. F. I.; Langendijk, J. A.; Leemans, C. R.

    2008-01-01

    Purpose To evaluate accuracy and interobserver variability in the assessment of 2-deoxy-2[F-18]fluoro-d-glucose-positron emission tomography (FDG-PET) for detection of recurrent laryngeal carcinoma after radiotherapy. Procedures Eleven experienced nuclear physicians from eight centres assessed 30 FDG-PET scans on the appearance of local recurrence (negative/equivocal/positive). Conservative (equivocal analysed as negative) and sensitive (equivocal analysed as positive) assessment strategies were compared to the reference standard (recurrence within 6months after PET). Results Seven patients had proven recurrences. For the conservative and sensitive strategy, the mean sensitivity was 87% and 97%, specificity 81% and 63%, positive predictive values 61% and 46% and negative predictive values 96% and 99%, respectively. Interobserver variability showed a reasonable relation in comparison to the reference standard (kappa = 0.55). Conclusions FDG-PET has acceptable interobserver agreement and yields good negative predictive value for detection of recurrent laryngeal carcinoma. It could therefore be used as first diagnostic step and may reduce futile invasive diagnostics. PMID:18622649

  16. Diagnosis of ventriculoperitoneal shunt infection using [F-18]-FDG PET: a case report.

    PubMed

    Rehman, T; Chohan, M O; Yonas, H

    2011-06-01

    Infection of cerebrospinal fluid (CSF) shunts is a common occurrence and can often be difficult to diagnose using standard analysis of shunt fluid. This article presents the first case report on the diagnosis of a CSF shunt infection on FDG PET scan. A 26-year-old female underwent ventriculoperitoneal shunt placement after developing a pseudomeningocele subsequent to a suboccipital craniectomy for Chiari malformation. Two months later, the patient presented with abdominal pain and non-specific symptoms and was found to have a perisplenic abscess for which she was adequately treated. Failure of her symptoms to solve and an initial negative shunt CSF analysis prompted the search for other sources of infection. An FDG PET scan performed a week later found evidence of increase tracer uptake around the distal tip of the catheter and a repeat shunt CSF analysis showed evidence of CSF infection. FDG PET may be useful in diagnosing shunt related infections in case of high clinical suspicion when standard diagnostic modalities fail to diagnose hardware infection.

  17. Functional neuroimaging using F-18 FDG PET/CT in amnestic mild cognitive impairment: A preliminary study

    PubMed Central

    Tripathi, Madhavi; Tripathi, Manjari; Sharma, Rajnish; Jaimini, Abhinav; MD’Souza, Maria; Saw, Sanjiv; Mondal, Anupam; Kushwaha, Suman

    2013-01-01

    Background and Objective: People with amnestic mild cognitive impairment (aMCI) are at a higher risk of developing Alzheimers Dementia (AD) than their cognitively normal peers. Decreased glucose metabolism with F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) is a downstream marker of neuronal injury and neurodegeneration. The risk of developing AD is higher in patients with aMCI who have a pattern of AD related glucose metabolic changes on FDG-PET than those who do not have these changes. We evaluated the utility of visual and ‘statistical parametric mapping (SPM)-supported reading’ of the FDG-PET scans of patients clinically classified as aMCI for identification of predementia patterns and for prediction of their progression to AD (PTAD). Patients and Methods: A total of 35 patients diagnosed as aMCI (mini mental state examination (MMSE) score ≥ 25) at the cognitive disorders and memory (CDM) clinic of speciality neurology centers were referred for a resting FDG-PET study. All patients had a detailed neurological, neuropsychological, and magnetic resonance imaging (MRI) evaluation prior to referral. Mean age of patients was 67.9 ± 8.7 (standard deviation (SD)) years, male: female (M: F) =26:9. Twenty healthy age-matched controls were included in the study for SPM (http://www.fil.ion.ucl.ac.uk/spm/). Scans were interpreted visually and using SPM. Each scan was classified as high, intermediate, or low likelihood for PTAD. Results: On visual analysis, four scans were classified as high likelihood of PTAD and reveled hypometabolism in AD related territories. Seven patients had hypometabolism in at least one AD related territory and were classified as intermediate likelihood for PTAD. Two patients had hypometabolism in other than AD territories, while 22 patients did not show any significant hypometabolism on their FDG-PET scans and were classified as low likelihood for PTAD. SPM analysis of these cases confirmed the areas hypometabolism in all

  18. Unexpected Second Primary Malignancies Detected by F-18 FDG PET/CT During Follow-up for Primary Malignancy: Two Case Reports.

    PubMed

    Bang, Ji-In; Lee, Eun Seong; Kim, Tae-Sung; Kim, Seok-Ki

    2015-03-01

    As the survival rate of cancer patients has increased over the last few decades, the risk of cancer survivors developing second primary malignancies has gained attention. We report two rare cases of second primary hematologic malignancy detected by (18)F-fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) during follow-up for primary solid malignancies. Acute lymphoblastic leukemia developed in a breast cancer patient and non-Hodgkin lymphoma in an anal cancer patient. F-18 FDG PET/CT findings led to the diagnosis of unexpected second primary hematologic malignancy in cancer survivors in these two cases.

  19. Pharmacologic perturbation as a potential tool to increase the sensitivity of FDG-PET in the evaluation of brain tumors

    SciTech Connect

    Wong, F.C.L.; Kim, E.E.; Yung, W.K.A.

    1994-05-01

    The usefulness of F-18 FDG PET in the study of brain tumors is limited by the high baseline cortical uptake which decreases the contrast of the tumor. Two alternatives to increase the tumor/background contrast have been reported: barbiturate-induced coma and postprandial state. This project evaluates the effects of sedation with diazepam or of oral glucose intake on the brain tumor/background contrast during F-18 FDG PET studies.

  20. Registration of parametric dynamic F-18-FDG PET/CT breast images with parametric dynamic Gd-DTPA breast images

    NASA Astrophysics Data System (ADS)

    Magri, Alphonso; Krol, Andrzej; Lipson, Edward; Mandel, James; McGraw, Wendy; Lee, Wei; Tillapaugh-Fay, Gwen; Feiglin, David

    2009-02-01

    This study was undertaken to register 3D parametric breast images derived from Gd-DTPA MR and F-18-FDG PET/CT dynamic image series. Nonlinear curve fitting (Levenburg-Marquardt algorithm) based on realistic two-compartment models was performed voxel-by-voxel separately for MR (Brix) and PET (Patlak). PET dynamic series consists of 50 frames of 1-minute duration. Each consecutive PET image was nonrigidly registered to the first frame using a finite element method and fiducial skin markers. The 12 post-contrast MR images were nonrigidly registered to the precontrast frame using a free-form deformation (FFD) method. Parametric MR images were registered to parametric PET images via CT using FFD because the first PET time frame was acquired immediately after the CT image on a PET/CT scanner and is considered registered to the CT image. We conclude that nonrigid registration of PET and MR parametric images using CT data acquired during PET/CT scan and the FFD method resulted in their improved spatial coregistration. The success of this procedure was limited due to relatively large target registration error, TRE = 15.1+/-7.7 mm, as compared to spatial resolution of PET (6-7 mm), and swirling image artifacts created in MR parametric images by the FFD. Further refinement of nonrigid registration of PET and MR parametric images is necessary to enhance visualization and integration of complex diagnostic information provided by both modalities that will lead to improved diagnostic performance.

  1. F18 EF5 PET/CT Imaging in Patients with Brain Metastases from Breast Cancer

    DTIC Science & Technology

    2013-07-01

    with Brain Metastases from Breast Cancer PRINCIPAL INVESTIGATOR: Lilie Lin, MD CONTRACTING ORGANIZATION: University of Pennsylvania...Annual 3. DATES COVERED 01 July 2012 to 30 June 2013 4. TITLE AND SUBTITLE F18 EF5 PET/CT Imaging in Patients with Brain Metastases from Breast 5a...SUPPLEMENTARY NOTES 14. ABSTRACT The aim of this study is to estimate the degree of residual hypoxia after whole brain radiation therapy in patients

  2. Validating novel tau PET tracer [F-18]-AV-1451 (T807) on postmortem brain tissue

    PubMed Central

    Marquie, Marta; Normandin, Marc D.; Vanderburg, Charles R.; Costantino, Isabel; Bien, Elizabeth A.; Rycyna, Lisa G.; Klunk, William E.; Mathis, Chester A.; Ikonomovic, Milos D.; Debnath, Manik L.; Vasdev, Neil; Dickerson, Bradford C.; Gomperts, Stephen N.; Growdon, John H.; Johnson, Keith A.; Frosch, Matthew P.; Hyman, Bradley T.; Gomez-Isla, Teresa

    2016-01-01

    Objective To examine region and substrate-specific autoradiographic and in vitro binding patterns of PET tracer [F-18]-AV-1451 (previously known as T807), tailored to allow in vivo detection of paired helical filament tau-containing lesions, and to determine whether there is off-target binding to other amyloid/non-amyloid proteins. Methods We applied [F-18]-AV-1451 phosphor screen autoradiography, [F-18]-AV-1451 nuclear emulsion autoradiography and [H-3]-AV-1451 in vitro binding assays to the study of postmortem samples from patients with a definite pathological diagnosis of Alzheimer’s disease, frontotemporal lobar degeneration-tau, frontotemporal lobar degeneration-TDP-43, progressive supranuclear palsy, corticobasal degeneration, dementia with Lewy bodies, multiple system atrophy, cerebral amyloid angiopathy and elderly controls free of pathology. Results Our data suggest that AV-1451 strongly binds to tau lesions primarily made of paired helical filaments in Alzheimer’s brains e.g. intra and extraneuronal tangles and dystrophic neurites, but does not seem to bind to a significant extent to neuronal and glial inclusions mainly composed of straight tau filaments in non-Alzheimer tauopathy brains or to β-amyloid, α-synuclein or TDP-43-containing lesions. AV-1451 off-target binding to neuromelanin- and melanin-containing cells and, to a lesser extent, to brain hemorrhagic lesions was identified. Interpretation Our data suggest that AV-1451 holds promise as surrogate marker for the detection of brain tau pathology in the form of tangles and paired helical filament-tau-containing neurites in Alzheimer’s brains but also point to its relatively lower affinity for lesions primarily made of straight tau filaments in non-Alzheimer tauopathy cases and to the existence of some AV-1451 off-target binding. These findings provide important insights for interpreting in vivo patterns of [F-18]-AV-1451 retention. PMID:26344059

  3. In vivo characterization of chronic traumatic encephalopathy using [F-18]FDDNP PET brain imaging.

    PubMed

    Barrio, Jorge R; Small, Gary W; Wong, Koon-Pong; Huang, Sung-Cheng; Liu, Jie; Merrill, David A; Giza, Christopher C; Fitzsimmons, Robert P; Omalu, Bennet; Bailes, Julian; Kepe, Vladimir

    2015-04-21

    Chronic traumatic encephalopathy (CTE) is an acquired primary tauopathy with a variety of cognitive, behavioral, and motor symptoms linked to cumulative brain damage sustained from single, episodic, or repetitive traumatic brain injury (TBI). No definitive clinical diagnosis for this condition exists. In this work, we used [F-18]FDDNP PET to detect brain patterns of neuropathology distribution in retired professional American football players with suspected CTE (n = 14) and compared results with those of cognitively intact controls (n = 28) and patients with Alzheimer's dementia (AD) (n = 24), a disease that has been cognitively associated with CTE. [F-18]FDDNP PET imaging results in the retired players suggested the presence of neuropathological patterns consistent with models of concussion wherein brainstem white matter tracts undergo early axonal damage and cumulative axonal injuries along subcortical, limbic, and cortical brain circuitries supporting mood, emotions, and behavior. This deposition pattern is distinctively different from the progressive pattern of neuropathology [paired helical filament (PHF)-tau and amyloid-β] in AD, which typically begins in the medial temporal lobe progressing along the cortical default mode network, with no or minimal involvement of subcortical structures. This particular [F-18]FDDNP PET imaging pattern in cases of suspected CTE also is primarily consistent with PHF-tau distribution observed at autopsy in subjects with a history of mild TBI and autopsy-confirmed diagnosis of CTE.

  4. In vivo characterization of chronic traumatic encephalopathy using [F-18]FDDNP PET brain imaging

    PubMed Central

    Barrio, Jorge R.; Small, Gary W.; Wong, Koon-Pong; Huang, Sung-Cheng; Liu, Jie; Merrill, David A.; Giza, Christopher C.; Fitzsimmons, Robert P.; Omalu, Bennet; Bailes, Julian; Kepe, Vladimir

    2015-01-01

    Chronic traumatic encephalopathy (CTE) is an acquired primary tauopathy with a variety of cognitive, behavioral, and motor symptoms linked to cumulative brain damage sustained from single, episodic, or repetitive traumatic brain injury (TBI). No definitive clinical diagnosis for this condition exists. In this work, we used [F-18]FDDNP PET to detect brain patterns of neuropathology distribution in retired professional American football players with suspected CTE (n = 14) and compared results with those of cognitively intact controls (n = 28) and patients with Alzheimer’s dementia (AD) (n = 24), a disease that has been cognitively associated with CTE. [F-18]FDDNP PET imaging results in the retired players suggested the presence of neuropathological patterns consistent with models of concussion wherein brainstem white matter tracts undergo early axonal damage and cumulative axonal injuries along subcortical, limbic, and cortical brain circuitries supporting mood, emotions, and behavior. This deposition pattern is distinctively different from the progressive pattern of neuropathology [paired helical filament (PHF)-tau and amyloid-β] in AD, which typically begins in the medial temporal lobe progressing along the cortical default mode network, with no or minimal involvement of subcortical structures. This particular [F-18]FDDNP PET imaging pattern in cases of suspected CTE also is primarily consistent with PHF-tau distribution observed at autopsy in subjects with a history of mild TBI and autopsy-confirmed diagnosis of CTE. PMID:25848027

  5. Imaging Keratitis-Icthyosis-Deafness (KID) syndrome with FDG-PET (F18-fluorodeoxiglucose-Positron Emission Tomography).

    PubMed

    Aparici, Carina Mari; Arcienega, Daniela; Cho, Eric; Hawkins, Randy

    2010-01-01

    Keratitis-Icthyosis-Deafness (KID) syndrome is a rare dysplasia characterized by vascularizing keratitis, congenital sensorineural hearing-loss, and progressive erythrokeratoderma. To our knowledge, this is the first KID syndrome imaged with FDG-PET in the literature. This paper is intended to help familiarize with the FDG abnormalities related to this rare entity.

  6. Predictive value of F-18 FDG PET/CT quantization parameters in diffuse large B cell lymphoma: a meta-analysis with 702 participants.

    PubMed

    Xie, Mixue; Wu, Kefei; Liu, Yan; Jiang, Qi; Xie, Yanhui

    2015-01-01

    F-18 fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) is considered to be the most beneficial imaging method for staging patients with lymphoma. Whether maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) acquired from F-18 FDG PET/CT are predictors of prognosis of diffuse large B cell lymphoma (DLBCL) is controversial, with some studies concluding that it is and others concluding the opposite. Therefore, a systematic review was performed to explore the relationship of F-18 FDG PET/CT quantization parameters with the prognosis of DLBCL. Seven trials with a total of 703 DLBCL patients were included for analysis. Hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS), and odds ratios (ORs) for 3-year PFS and OS were pooled using the STATA package. Combined results suggested a strong link between the high SUVmax, MTV and TLG values and the poor 3-year PFS with ORs of 2.59, 3.69 and 2.29, respectively. Similarly, high MTV and TLG values unfavorably influenced the 3-year OS with ORs of 5.40 and 2.19, respectively. The pooled results also showed that high SUVmax and MTV were negative predictors of PFS with HRs of 1.61 (p = 0.038) and 2.18 (p = 0.000), respectively. The TLG value was not predictive of PFS. And for OS, only high MTV was a strong predictor of poor prognosis in DLBCL with HR 2.99 (p = 0.000). Our results suggested that SUVmax and MTV may be significant prognostic markers for PFS and MTV may be the only predictor for OS in DLBCL.

  7. Three-dimensional texture analysis of contrast enhanced CT images for treatment response assessment in Hodgkin lymphoma: Comparison with F-18-FDG PET

    SciTech Connect

    Knogler, Thomas; El-Rabadi, Karem; Weber, Michael; Karanikas, Georgios; Mayerhoefer, Marius E.

    2014-12-15

    Purpose: To determine the diagnostic performance of three-dimensional (3D) texture analysis (TA) of contrast-enhanced computed tomography (CE-CT) images for treatment response assessment in patients with Hodgkin lymphoma (HL), compared with F-18-fludeoxyglucose (FDG) positron emission tomography/CT. Methods: 3D TA of 48 lymph nodes in 29 patients was performed on venous-phase CE-CT images before and after chemotherapy. All lymph nodes showed pathologically elevated FDG uptake at baseline. A stepwise logistic regression with forward selection was performed to identify classic CT parameters and texture features (TF) that enable the separation of complete response (CR) and persistent disease. Results: The TF fraction of image in runs, calculated for the 45° direction, was able to correctly identify CR with an accuracy of 75%, a sensitivity of 79.3%, and a specificity of 68.4%. Classical CT features achieved an accuracy of 75%, a sensitivity of 86.2%, and a specificity of 57.9%, whereas the combination of TF and CT imaging achieved an accuracy of 83.3%, a sensitivity of 86.2%, and a specificity of 78.9%. Conclusions: 3D TA of CE-CT images is potentially useful to identify nodal residual disease in HL, with a performance comparable to that of classical CT parameters. Best results are achieved when TA and classical CT features are combined.

  8. Active transport of C-11-Methyl-D-Glucose and 3-F-18-Deoxyglucose in acute ischemic brain disease and Huntington's chorea, studied by positron-emission-tomography (PET)

    SciTech Connect

    Vyska, K.; Magloire, R.; Schuier, F.; Machulla, H.J.; Knust, E.J.; Lange, W.; Becker, V.; Spohr, G.; Notohamiprodjo, G.; Feinendegen, L.E.

    1984-01-01

    C-11-Methyl-D-Glucose (CMG) and 3-F-18-Deoxyglucose (3FDG) were demonstrated to be non-metabolizable glucose analogues which are transported across the blood-brain-barrier into and out of tissue via the glucose carrier system (GCS). These two substances were used as indicators for determining the perfusion-independent rate constant of GCS in the brain. Five normals with informed consent, 12 patients with acute ischemic brain disease and 9 patients with initial and advanced Huntington's chorea were examined by PET after i.v. application of 5 mCi of GMG or 3FDG. In each patient 30 transaxial images were registered in 1 selected plane, image collection time being 1 min. Time-activity curves were created from different regions of interest. The slope to tracer steady state between tissue and blood yields the perfusion-independent rate constant of GCS from tissue to blood (k/sub 2/). In normals k/sub 2/ for CMG was 0.235 +- 0.03/min, as expected, and for 3FDG 0.47 +- 0.07/min indicating a higher affinity to GCS for 3FDG than CMG. In acute ischemic brain disease k/sub 2/ was normal or reduced at the site of insult for both CMG and 3FDG. In Huntington's chorea, k/sub 2/ was reduced in the basal ganglia but normal or occasionally significantly increased in frontal or occipital cortical areas, for CMG and 3FDG. The authors conclude that CMG permits noninvasive analysis of the perfusion-independent rate constant of CCS. 3FDG shows a higher affinity for CCS than CMC but gives comparable information.

  9. Non-invasive breast biopsy method using GD-DTPA contrast enhanced MRI series and F-18-FDG PET/CT dynamic image series

    NASA Astrophysics Data System (ADS)

    Magri, Alphonso William

    This study was undertaken to develop a nonsurgical breast biopsy from Gd-DTPA Contrast Enhanced Magnetic Resonance (CE-MR) images and F-18-FDG PET/CT dynamic image series. A five-step process was developed to accomplish this. (1) Dynamic PET series were nonrigidly registered to the initial frame using a finite element method (FEM) based registration that requires fiducial skin markers to sample the displacement field between image frames. A commercial FEM package (ANSYS) was used for meshing and FEM calculations. Dynamic PET image series registrations were evaluated using similarity measurements SAVD and NCC. (2) Dynamic CE-MR series were nonrigidly registered to the initial frame using two registration methods: a multi-resolution free-form deformation (FFD) registration driven by normalized mutual information, and a FEM-based registration method. Dynamic CE-MR image series registrations were evaluated using similarity measurements, localization measurements, and qualitative comparison of motion artifacts. FFD registration was found to be superior to FEM-based registration. (3) Nonlinear curve fitting was performed for each voxel of the PET/CT volume of activity versus time, based on a realistic two-compartmental Patlak model. Three parameters for this model were fitted; two of them describe the activity levels in the blood and in the cellular compartment, while the third characterizes the washout rate of F-18-FDG from the cellular compartment. (4) Nonlinear curve fitting was performed for each voxel of the MR volume of signal intensity versus time, based on a realistic two-compartment Brix model. Three parameters for this model were fitted: rate of Gd exiting the compartment, representing the extracellular space of a lesion; rate of Gd exiting a blood compartment; and a parameter that characterizes the strength of signal intensities. Curve fitting used for PET/CT and MR series was accomplished by application of the Levenburg-Marquardt nonlinear regression

  10. Guidelines for brain radionuclide imaging. Perfusion single photon computed tomography (SPECT) using Tc-99m radiopharmaceuticals and brain metabolism positron emission tomography (PET) using F-18 fluorodeoxyglucose. The Belgian Society for Nuclear Medicine.

    PubMed

    Vander Borght, T; Laloux, P; Maes, A; Salmon, E; Goethals, I; Goldman, S

    2001-12-01

    The purpose of these guidelines is to assist nuclear medicine practitioners in recommending, performing, interpreting, and reporting the results of brain perfusion SPECT studies using Tc-99m radiopharmaceuticals and brain metabolism PET studies using F-18 fluorodeoxyglucose (FDG). These guidelines have been adapted and extended from those produced by the Society of Nuclear Medicine (Juni et al., 1998) and the European Association of Nuclear Medicine by a Belgian group of experts in the field trained in neurology and/or nuclear medicine. Some indications are not universally approved (e.g. brain death), but largely supported by the literature. They have been included in these guidelines in order to provide recommendations and a standardised protocol.

  11. Breath-hold and free-breathing F-18-FDG-PET/CT in malignant melanoma—detection of additional tumoral foci and effects on quantitative parameters

    PubMed Central

    Bärwolf, Robert; Zirnsak, Mariana; Freesmeyer, Martin

    2017-01-01

    Abstract During PET/CT acquisition, respiratory motion generates artifacts in the form of breath-related blurring, which may impair lesion detectability and diagnostic accuracy. This observational study was undertaken to verify whether breath-hold F-18-FDG-PET/CT (bhPET) detects additional foci compared to free-breathing PET/CT (fbPET) in cases of malignant melanoma, and to assess the impact of breath-holding on standard uptake values (SUV) and metabolic isocontoured volume (mVic40). Thirty-four patients with melanoma were examined. BhPET and fbPET findings of 117 lesions were compared and correlated with standard contrast-enhanced (ce) CT and MRI for lesion verification. Quantitative parameters (SUVmax, SUVmean, and mVic40) were assessed for both methods and evaluated by linear regression and Spearman correlation. The impact of lesion size and time interval between investigations was analyzed. In 1 patient, a CT-confirmed liver metastasis was seen only on bhPET but not on fbPET. At bhPET, SUVmax, and SUVmean proved significantly higher and mVic40 significantly lower than at fbPET. The positive effect on SUVmax and SUVmean was more pronounced in smaller lesions, whereas the time interval between bhPET and fbPET did not influence SUV or mVic40. In our patient cohort, bhPET yielded significantly higher SUV and provided improved volumetric lesion definition, particularly of smaller lesions. Also one additional liver lesion was identified. Breath-hold PET/CT is technically feasible, and may become clinically useful when fine quantitative evaluations are needed. PMID:28079829

  12. Semi-Quantitative Calculations of Primary Tumor Metabolic Activity Using F-18 FDG PET/CT as a Predictor of Survival in 92 Patients With High-Grade Bone or Soft Tissue Sarcoma.

    PubMed

    Andersen, Kim Francis; Fuglo, Hanna Maria; Rasmussen, Sine Hvid; Petersen, Michael Mork; Loft, Annika

    2015-07-01

    To assess the prognostic value of primary tumor metabolic activity in patients with high-grade bone sarcomas (BS) or soft tissue sarcomas (STS) using F-18 FDG PET/CT. A single-site, retrospective study including 92 patients with high-grade BS or STS. Pretreatment F-18 FDG PET/CT scan was performed. Clinical data were registered. Accuracy of maximum standardized uptake value of primary tumor (SUVmax) and tumor-to-background (T/B) uptake ratio as prognostic variables and identification of cut-off values to group patients were determined. Kaplan-Meier survival estimates and log-rank test were used to compare survival distributions. Prognostic variables were assessed using Cox proportional hazards regression analysis. Forty-one of 92 patients died during follow-up (45%). Average survival was 6.5 years (95% CI 5.8-7.3 years) and probability of 5-year survival was 52%. Accuracy of SUVmax and T/B uptake ratio as prognostic variables in all patients and during subgroup analysis of patients with STS was significant. No significant results for AUCs were registered in patients with BS. Surgery was independently prognostic for survival throughout multivariate regression analysis of all patients (P = 0.001, HR 3.84) and subgroup analysis (BS: P = 0.02, HR 11.62; STS: P = 0.005, HR 4.13). SUVmax was significant as prognostic variable in all patients (P = 0.02, HR 3.66) and in patients with STS (P = 0.007, HR 3.75). No significant results were demonstrated for T/B uptake ratio. Estimation of primary tumor metabolic activity with pretherapeutic SUVmax using F-18 FDG PET/CT demonstrates independent properties beyond histologic grading for prediction of survival in patients with high-grade STS, but not with high-grade BS.

  13. Oncocytic carcinoid tumor of the lung with intense F-18 fluorodeoxyglucose (FDG) uptake in positron emission tomography-computed tomography (PET/CT).

    PubMed

    Tanabe, Yuki; Sugawara, Yoshifumi; Nishimura, Rieko; Hosokawa, Kohei; Kajihara, Makoto; Shimizu, Teruhiko; Takahashi, Tadaaki; Sakai, Shinya; Sawada, Shigeki; Yamashita, Motohiro; Ohtani, Haruhiko

    2013-10-01

    The present report describes a case of typical carcinoid tumor with intense fluorodeoxyglucose (FDG) uptake. The most of tumor cells were characterized by eosinophilic cytoplasm resulting from accumulation of mitochondria, which was called an oncocytic carcinoid tumor. Glucose transporter type 1 (GLUT-1) was expressed in a membranous pattern in the oncocytic component. Oncocytic carcinoid tumors could show intense FDG uptake due to the numerous intracellular mitochondria and the membranous overexpression of GLUT-1. Thus, it could be a potential pitfall of interpreting FDG-PET/CT image.

  14. F18 EF5 PET/CT Imaging in Patients with Brain Metastases from Breast Cancer

    DTIC Science & Technology

    2014-09-01

    Pennsylvania, where more patients are offered gamma knife radiotherapy upfront rather than whole brain radiotherapy which has impacted our accrual rates...to follow. Furthermore, patients with better performance status often receive upfront gamma knife radiotherapy instead. These patients were...four weeks post treatment. Additionally, opening up the protocol enrollment to include patients receiving gamma knife radiotherapy was done

  15. Comparison of F-18 FDG-PET/CT and Tc-99m MIBI in the preoperative evaluation of cold thyroid nodules in the same patient group.

    PubMed

    Sager, Sait; Vatankulu, Betul; Erdogan, Ezgi; Mut, Sanem; Teksoz, Serkan; Ozturk, Tulin; Sonmezoglu, Kerim; Kanmaz, Bedii

    2015-09-01

    Recent studies have reported that standardized uptake values of FDG-PET imaging might predict malignant thyroid nodules and can be used in the preoperative evaluation of thyroid lesions. The aim of our study was to evaluate FDG-PET imaging in patients with cold thyroid nodules and to compare the imaging findings with Tc-99m MIBI scans and with post-op histopathology results. Twenty-three patients (18F, 5M) with 24 nodules that were suspicious in ultrasound and cold in Tc-99m pertechnetate scan, were included in the study. Each nodule underwent sonographically guided fine-needle aspiration biopsy. FDG-PET and MIBI scans were performed with an interval of 3-5 days. All patients underwent thyroidectomy and their FDG-PET, and MIBI thyroid scan results were compared with post-thyroidectomy pathology results. Post-op histopathology results found 7 malignant and 17 benign nodules. Six of the seven malignant nodules had increased uptake, which were positive for malignancy in both PET and MIBI scans. Each imaging method used different radiopharmaceuticals but showed one false-negative result in two different patients. FDG-PET produced false positives in eight nodules and MIBI scans found false positives in four nodules. FDG-PET imaging and MIBI scan showed the same sensitivity in malignant nodule evaluation, but their specificity differed. As a result, we suggest that FDG-PET imaging is not superior to MIBI scanning in differentiating malignant from benign thyroid nodules. MIBI imaging should be the first choice in the preoperative evaluation of patients with cold thyroid nodules as an adjunct procedure to FNAB because of its low cost and availability. This imaging technique can be used routinely in patients who are reluctant to undergo FNAB.

  16. Radiosynthesis and Biological Evaluation of alpha-[F-18]Fluoromethyl Phenylalanine for Brain Tumor Imaging

    PubMed Central

    Huang, Chaofeng; Yuan, Liya; Rich, Keith; McConathy, Jonathan

    2013-01-01

    Objectives Radiolabeled amino acids have proven utility for imaging brain tumors in humans, particularly those that target system L amino acid transport. We have prepared the novel phenylalanine analogue, α-[18F]fluoromethyl phenylalanine (FMePhe, 9), as part of an effort to develop new system L tracers that can be prepared in high radiochemical yield through nucleophilic [18F]fluorination. The tumor imaging properties of both enantiomers this new tracer were evaluated through cell uptake, biodistribution and microPET studies in the mouse DBT model of high grade glioma. Methods The non-radioactive form of 9 and the cyclic sulfamidate labeling precursor were prepared from commercially available racemic α-benzylserine. Racemic [18F]9 was prepared from the labeling precursor in two steps using standard [18F]fluoride nucleophilic reaction conditions followed by acidic deprotection. The individual enantiomers [18F]9a and [18F]9b were isolated using preparative chiral HPLC. In vitro uptake inhibition assays were performed with each enantiomer using DBT cells. Biodistribution and microPET/CT studies were performed with each enantiomers in male BALB/c mice at approximately 2 weeks after implantation of DBT tumor cells. Results Radiolabeling of the cyclic sulfamidate precursor 5 provide racemic [18F]9 in high radiochemical yield (60–70%, n = 4) and high radiochemical purity (>96%, n = 4). In vitro uptake assays demonstrate that both [18F]9a and [18F]9b undergo tumor cell uptake through system L transport. The biodistribution studies using the single enantiomers [18F]9a and [18F]9b demonstrated good tumor uptake with lower uptake in most normal tissues, and [18F]9a had higher tumor uptake than [18F]9b. MicroPET imaging demonstrated good tumor visualization within 10 min of injection, rapid uptake of radioactivity, and tumor to brain ratios of approximately 6:1 at 60 min postinjection. Conclusions The novel PET tracer, [18F]FMePhe, is readily synthesized in good yield

  17. A strategy for obtaining both resting and psychologically activated state metabolic data from a single PET study using (F-18)-fluorodeoxyglucose(FDG)

    SciTech Connect

    Chang, J.; Duara, R.; Barker, W.; Apicella, A.; Gilson, A.

    1985-05-01

    When psychological activation is studied with PET using the deoxyglucose method, a stable and specific psychological state for at least 30 minutes is required before commencing the scan. At this time, if the subject reverts to the testing state, a progressive degradation of the activated pattern occurs. However, a strategy could be used to obtain corrected activation state data and resting state data in a single study using a tracer such as FDG. The amount of tracer FDG and FDG-6P in the tissue at the time of study completion, t, will be the sum of the remaining quantity (R) of tracer accumulated in the tissue at the time T, when activation ceases, and the uptake during the subsequent period t-T when resting state glucose transport kinetics apply.

  18. Assessment of myocardial injury after reperfusion with T1-201, Tc-99m pyrophosphate (PPi) and F-18 deoxyglucose (FDG)

    SciTech Connect

    Sochor, H.; Schwaiger, M.; Hansen, H.W.; Parodi, O.; Selin, C.; Huang, S.C.; Ellison, D.; Grover, M.; Schelbert, H.R.

    1984-01-01

    The authors previously demonstrated that enhanced glucose utilization assessed by FDG and Positron-CT in reperfused myocardium predicts functional recovery. This study compared segmental uptake of FDG with T1-201 and PPi as conventional indicators of tissue viability in 5 dogs, submitted to a 3 hr LAD occlusion followed by 24 hrs of reperfusion (R). Myocardial blood flow (MBF) was then determined by microspheres and T1-201, PPi and FDG administered i.v. Regional tracer concentrations were determined by well counting of tissue samples and grouped according to MBF (% of control). Severe flow reductions were associated with PPi uptake increase, T1-201 decrease and depressed glucose utilization representing mainly irreversible injury. Moderately reduced MBF areas showed the highest PPi uptake with T1-201 similar to MBF, but preserved FDG uptake not different from control, indicating partially viable tissue. Areas with MBF >60% had significantly increased PPi despite normal T1-201 uptake and enhanced glucose utilization and thus, preserved viability. Thus, assessment of tissue injury by conventional tracers such as T1-201 and PPi is limited. By contrast, quantification of residual glucose metabolism by PCT appears more accurate for evaluating myocardial viability and predicting potential functional recovery.

  19. Volume-Based F-18 FDG PET/CT Imaging Markers Provide Supplemental Prognostic Information to Histologic Grading in Patients With High-Grade Bone or Soft Tissue Sarcoma.

    PubMed

    Andersen, Kim Francis; Fuglo, Hanna Maria; Rasmussen, Sine Hvid; Petersen, Michael Mork; Loft, Annika

    2015-12-01

    The aim of the study is to assess the prognostic value of different volume-based calculations of tumor metabolic activity in the initial assessment of patients with high-grade bone sarcomas (BS) and soft tissue sarcomas (STS) using F-18 FDG PET/CT.A single-site, retrospective study from 2002 to 2012 including 92 patients with histologically verified high-grade BS (N = 37) or STS (N = 55). All patients underwent a pretreatment F-18 FDG PET/CT scan. Clinical data were registered. Measurements of the accuracy of metabolic tumor volume with a preset threshold of 40% of the maximum standardized uptake value of primary tumor (MTV40%) and total lesion glycolysis (TLG) as prognostic variables and identification of optimal discriminating cut-off values were performed through ROC curve analysis. Patients were grouped according to the cut-off values. All deaths were considered an event in survival analysis. Kaplan-Meier survival estimates and log-rank test were used to compare the degree of equality of survival distributions. Prognostic variables with related hazard ratios (HR) were assessed using Cox proportional hazards regression analysis.Forty-one of 92 patients died during follow-up (45%; 12 BS and 29 STS). Average survival for included patients was 6.5 years (95% CI 5.8-7.3 years) and probability of 5-year survival was 52%. There was a high-significant accuracy of TLG and MTV40% as prognostic variables when looking on all patients and during subgroup analysis. AUCs were higher for TLG than for MTV40%. TLG above optimal cut-off value was the only variable which was independently prognostic for survival throughout multivariate regression analysis of all included patients (P = 0.01, HR 4.78 [95% CI 1.45-15.87]) and subgroup analysis (BS: P = 0.04, HR 11.11 [95% CI 1.09-111.11]; STS: P < 0.05, HR 3.37 [95% CI 1.02-11.11]). No significant results were demonstrated for MTV40%.Volume-based F-18 FDG PET/CT imaging markers in terms of pretreatment estimation

  20. Haematogenous muscular metastasis of non-small cell lung cancer in F-18 fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Savas, Karyagar; Pinar, Koc Zehra; Sevda, Karyagar Saglampinar; Evrim, Savli; Halit, Cinarka; Sevdegul, Mungan; Ansal, Balci Tansel

    2014-01-01

    Aim of the study F-18 FDG PET/CT is the most effective method for demonstrating extrapulmonary metastases of lung cancer. The aim of this study is to investigate the level of muscular metastasis of non-small-cell lung carcinoma (NSCLC) in F-18 FDG PET/CT and to demonstrate the characteristics of this special group of patients. Material and methods A total of 1150 patients with the diagnosis of NSCLC, who were referred for F-18 FDG PET/CT, were included into the study. Among these patients, the findings of 13 who were shown to have muscle metastases were studied. Results In the retrospective analysis of the patients, 13 patients (12 male, 1 female; mean: 59 ±7 years old) were found to have haematogenous (excluding local invasion) muscular metastases of NSCLC using F-18 FDG PET/CT. Two of the 13 patients had only muscular metastases (one patient isolated, one patient two foci). The other 11 patients had additional distant metastases in six metastatic sites (bone in 7 patients, distant lymph node in 6, adrenal gland in 5, contralateral lung in 3, liver in 1, and brain metastasis in 1 patient). Five patients died during the mean 11 ±8 months follow up. Conclusions Muscular metastasis is not a rare condition, especially in F-18 FDG PET/CT examinations, and is frequently associated with additional distant metastases. PMID:26557766

  1. Monte Carlo estimation of radiation dose in organs of female and male adult phantoms due to FDG-F18 absorbed in the lungs

    NASA Astrophysics Data System (ADS)

    Belinato, Walmir; Santos, William S.; Silva, Rogério M. V.; Souza, Divanizia N.

    2014-03-01

    The determination of dose conversion factors (S values) for the radionuclide fluorodeoxyglucose (18F-FDG) absorbed in the lungs during a positron emission tomography (PET) procedure was calculated using the Monte Carlo method (MCNPX version 2.7.0). For the obtained dose conversion factors of interest, it was considered a uniform absorption of radiopharmaceutical by the lung of a healthy adult human. The spectrum of fluorine was introduced in the input data file for the simulation. The simulation took place in two adult phantoms of both sexes, based on polygon mesh surfaces called FASH and MASH with anatomy and posture according to ICRP 89. The S values for the 22 internal organs/tissues, chosen from ICRP No. 110, for the FASH and MASH phantoms were compared with the results obtained from a MIRD V phantoms called ADAM and EVA used by the Committee on Medical Internal Radiation Dose (MIRD). We observed variation of more than 100% in S values due to structural anatomical differences in the internal organs of the MASH and FASH phantoms compared to the mathematical phantom.

  2. SU-D-9A-02: Relative Effects of Threshold Choice and Spatial Resolution Modeling On SUV and Volume Quantification in F18-FDG PET Imaging of Anal Cancer Patients

    SciTech Connect

    Zhao, F; Bowsher, J; Palta, M; Czito, B; Willett, C; Yin, F

    2014-06-01

    Purpose: PET imaging with F18-FDG is utilized for treatment planning, treatment assessment, and prognosis. A region of interest (ROI) encompassing the tumor may be determined on the PET image, often by a threshold T on the PET standard uptake values (SUVs). Several studies have shown prognostic value for relevant ROI properties including maximum SUV value (SUVmax), metabolic tumor volume (MTV), and total glycolytic activity (TGA). The choice of threshold T may affect mean SUV value (SUVmean), MTV, and TGA. Recently spatial resolution modeling (SRM) has been introduced on many PET systems. SRM may also affect these ROI properties. The purpose of this work is to investigate the relative influence of SRM and threshold choice T on SUVmean, MTV, TGA, and SUVmax. Methods: For 9 anal cancer patients, 18F-FDG PET scans were performed prior to treatment. PET images were reconstructed by 2 iterations of Ordered Subsets Expectation Maximization (OSEM), with and without SRM. ROI contours were generated by 5 different SUV threshold values T: 2.5, 3.0, 30%, 40%, and 50% of SUVmax. Paired-samples t tests were used to compare SUVmean, MTV, and TGA (a) for SRM on versus off and (b) between each pair of threshold values T. SUVmax was also compared for SRM on versus off. Results: For almost all (57/60) comparisons of 2 different threshold values, SUVmean, MTV, and TGA showed statistically significant variation. For comparison of SRM on versus off, there were no statistically significant changes in SUVmax and TGA, but there were statistically significant changes in MTV for T=2.5 and T=3.0 and in SUVmean for all T. Conclusion: The near-universal statistical significance of threshold choice T suggests that, regarding harmonization across sites, threshold choice may be a greater concern than choice of SRM. However, broader study is warranted, e.g. other iterations of OSEM should be considered.

  3. Brain MRI, Tc-99m HMPAO SPECT and F-18 FP-CIT PET/CT Findings in a Patient with Wilson Disease: A Case Report.

    PubMed

    Kim, Seungyoo; Song, In Uk; Chung, Yong An; Choi, Eun Kyung; Oh, Jin Kyoung

    2014-12-01

    A 34-year-old female had experienced head and hand tremors with a dystonic component for 8 months. Brain MRI showed T2 high signal intensity in the periaqueductal region, dorsal midbrain and dorsal upper pons. No abnormal uptake was noted on Tc-99m HMPAO SPECT or F-18 FP-CIT PET/CT. Wilson disease was diagnosed according to the 2008 consensus guideline from the American Association for the Study of Liver Disease and 2012 guideline from the European Association for the Study of the Liver. This case demonstrates T2 signal change in the basal ganglia, excluding the putamen, in a Wilson disease patient with relatively severe clinical findings, but normal Tc-99m HMPAO SPECT and F-18 FP-CIT PET/CT.

  4. Effect of Donepezil on Wernicke Aphasia After Bilateral Middle Cerebral Artery Infarction: Subtraction Analysis of Brain F-18 Fluorodeoxyglucose Positron Emission Tomographic Images.

    PubMed

    Yoon, Seo Yeon; Kim, Je-Kyung; An, Young-Sil; Kim, Yong Wook

    2015-01-01

    Aphasia is one of the most common neurologic deficits occurring after stroke. Although the speech-language therapy is a mainstream option for poststroke aphasia, pharmacotherapy is recently being tried to modulate different neurotransmitter systems. However, the efficacy of those treatments is still controversial. We present a case of a 53-year-old female patient with Wernicke aphasia, after the old infarction in the territory of left middle cerebral artery for 8 years and the recent infarction in the right middle cerebral artery for 4 months. On the initial evaluation, the Aphasia Quotient in Korean version of the Western Aphasia Battery was 25.6 of 100. Baseline brain F-18 fluorodeoxyglucose positron emission tomographic images demonstrated a decreased cerebral metabolism in the left temporoparietal area and right temporal lobe. Donepezil hydrochloride, a reversible acetylcholinesterase inhibitor, was orally administered 5 mg/d for 6 weeks after the initial evaluation and was increased to 10 mg/d for the following 6 weeks. After the donepezil treatment, the patient showed improvement in language function, scoring 51.0 of 100 on Aphasia Quotient. A subtraction analysis of the brain F-18 fluorodeoxyglucose positron emission tomographic images after donepezil medication demonstrated increased uptake in both middle temporal gyri, extended to the occipital area and the left cerebellum. Thus, we suggest that donepezil can be an effective therapeutic choice for the treatment of Wernicke aphasia.

  5. F-18 SRA landing

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A highly-modified F-18 Hornet being flown by the Dryden Flight Research Center in a joint NASA/DOD/industry research program touches down on the main runway at Edwards Air Force Base following another research flight. The two-seat 'B' model F-18, formerly a support aircraft at DFRC, has been converted into a Sytems Research Aircraft (SRA) to flight test a variety of experimental components and sub-sytems. Among the more than 20 experiments is the Advanced L-Probe Air Data Integration, or 'ALADIN,' scheduled to begin flight tests this fall. Similiar to a standard pitot tube, the fuselage-mounted ALADIN probe measures and integrates Mach speed, altitude, angle of attack and side-slip angle. The experiment also incorporates a neural network computer which will be 'trained' to compute air data measured by the probe.

  6. [F-18]FDDNP microPET imaging correlates with brain Aβ burden in a transgenic rat model of Alzheimer disease: effects of aging, in vivo blockade, and anti-Aβ antibody treatment.

    PubMed

    Teng, Edmond; Kepe, Vladimir; Frautschy, Sally A; Liu, Jie; Satyamurthy, Nagichettiar; Yang, Fusheng; Chen, Ping-Ping; Cole, Graham B; Jones, Mychica R; Huang, Sung-Cheng; Flood, Dorothy G; Trusko, Stephen P; Small, Gary W; Cole, Gregory M; Barrio, Jorge R

    2011-09-01

    In vivo detection of Alzheimer's disease (AD) neuropathology in living patients using positron emission tomography (PET) in conjunction with high affinity molecular imaging probes for β-amyloid (Aβ) and tau has the potential to assist with early diagnosis, evaluation of disease progression, and assessment of therapeutic interventions. Animal models of AD are valuable for exploring the in vivo binding of these probes, particularly their selectivity for specific neuropathologies, but prior PET experiments in transgenic mice have yielded conflicting results. In this work, we utilized microPET imaging in a transgenic rat model of brain Aβ deposition to assess [F-18]FDDNP binding profiles in relation to age-associated accumulation of neuropathology. Cross-sectional and longitudinal imaging demonstrated that [F-18]FDDNP binding in the hippocampus and frontal cortex progressively increases from 9 to 18months of age and parallels age-associated Aβ accumulation. Specificity of in vivo [F-18]FDDNP binding was assessed by naproxen pretreatment, which reversibly blocked [F-18]FDDNP binding to Aβ aggregrates. Both [F-18]FDDNP microPET imaging and neuropathological analyses revealed decreased Aβ burden after intracranial anti-Aβ antibody administration. The combination of this non-invasive imaging method and robust animal model of brain Aβ accumulation allows for future longitudinal in vivo assessments of potential therapeutics for AD that target Aβ production, aggregation, and/or clearance. These results corroborate previous analyses of [F-18]FDDNP PET imaging in clinical populations.

  7. F-18 SRA landing

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A highly modified F-18B Hornet fighter being flown by NASA's Dryden Flight Research Center settles towards the runway at Edwards Air Force Base following another research flight. Known as the Systems Research Aircraft (SRA), the two-seat F-18 is currently engaged in a multi-year project to evaluate a variety of advanced control subsystems and sensors. Among the more than 20 experiments being researched in the joint NASA/DOD/industry program is the Electrical-Powered Actuation Design (EPAD), which is testing prototype aileron actuators which operate independently of the aircraft's hydraulic system. One experimental electrohydrostatic actuator (EHA) generates hydraulic force to move the aileron via a compact electric-driven hydraulic pump incorporated in the actuator itself. Another 'smart' actuator uses actuator-mounted electronics while a third electro-mechanical actuator is electrically operated and moves the aileron mechanically. Such actuators could eliminate much of the need for complex central hydraulic systems on future aircraft, with signifigant savings in weight and cost. They are also being evaluated for use on the planned Reusable Launch Vehicle.

  8. Radiolabeling of Poly(lactic-co-glycolic acid) (PLGA) Nanoparticles with Biotinylated F-18 Prosthetic Groups and Imaging of Their Delivery to the Brain with Positron Emission Tomography

    PubMed Central

    2015-01-01

    The avidin–biotin interaction permits rapid and nearly irreversible noncovalent linkage between biotinylated molecules and avidin-modified substrates. We designed a biotinylated radioligand intended for use in the detection of avidin-modified polymer nanoparticles in tissue with positron emission tomography (PET). Using an F-18 labeled prosthetic group, [18F]4-fluorobenzylamine, and a commercially available biotin derivate, NHS-PEG4-biotin, [18F]-fluorobenzylamide-poly(ethylene glycol)4-biotin ([18F]NPB4) was prepared with high purity and specific activity. The attachment of the [18F]NPB4 radioligand to avidin-modified poly(lactic-co-glycolic acid) (PLGA) nanoparticles was tested by using PET imaging to measure the kinetics of convection-enhanced delivery (CED) of nanoparticles of varying size to the rat brain. PET imaging enabled the direct observation of nanoparticle delivery by measurement of the spatial volume of distribution of radiolabeled nanoparticles as a function of time, both during and after the infusion. This work thus validates new methods for radiolabeling PEG-biotin derivatives and also provides insight into the fate of nanoparticles that have been infused directly into the brain. PMID:25322194

  9. F-18 FDG PET/CT and Tc-99m sulfur colloid SPECT imaging in the diagnosis and treatment of a case of dual solitary fibrous tumors of the retroperitoneum and pancreas.

    PubMed

    Azadi, Javad; Subhawong, Andrea; Durand, Daniel James

    2012-03-01

    Although FDG PET is increasingly used for the staging of many types of sarcoma, little has been written regarding the FDG PET imaging characteristics of solitary fibrous tumor. We report a patient undergoing FDG PET/CT surveillance for squamous cell carcinoma of the tongue who was incidentally found to have two soft tissue masses in the retroperitoneum and pancreatic tail. Due to their low degree of FDG avidity, they were followed conservatively for approximately one year as they gradually increased in size. Technetium-99m sulfur colloid SPECT helped confirm that the pancreatic tail mass was not a splenule, after which both lesions were surgically resected and found to be extrathoracic solitary fibrous tumors without malignant features. These findings suggest that, as with other low-grade sarcomas, benign extrathoracic solitary fibrous tumors exhibit relatively little glycolytic metabolism in vivo.

  10. Dynamic functional imaging of brain glucose utilization using fPET-FDG

    SciTech Connect

    Villien, Marjorie; Wey, Hsiao-Ying; Mandeville, Joseph B.; Catana, Ciprian; Polimeni, Jonathan R.; Sander, Christin Y.; Zürcher, Nicole R.; Chonde, Daniel B.; Fowler, Joanna S.; Rosen, Bruce R.; Hooker, Jacob M.

    2014-06-14

    We report that glucose is the principal source of energy for the brain and yet the dynamic response of glucose utilization to changes in brain activity is still not fully understood. Positron emission tomography (PET) allows quantitative measurement of glucose metabolism using 2-[18F]-fluorodeoxyglucose (FDG). However, FDG PET in its current form provides an integral (or average) of glucose consumption over tens of minutes and lacks the temporal information to capture physiological alterations associated with changes in brain activity induced by tasks or drug challenges. Traditionally, changes in glucose utilization are inferred by comparing two separate scans, which significantly limits the utility of the method. We report a novel method to track changes in FDG metabolism dynamically, with higher temporal resolution than exists to date and within a single session. Using a constant infusion of FDG, we demonstrate that our technique (termed fPET-FDG) can be used in an analysis pipeline similar to fMRI to define within-session differential metabolic responses. We use visual stimulation to demonstrate the feasibility of this method. Ultimately, this new method has a great potential to be used in research protocols and clinical settings since fPET-FDG imaging can be performed with most PET scanners and data acquisition and analysis are straightforward. fPET-FDG is a highly complementary technique to MRI and provides a rich new way to observe functional changes in brain metabolism.

  11. Dynamic functional imaging of brain glucose utilization using fPET-FDG

    DOE PAGES

    Villien, Marjorie; Wey, Hsiao-Ying; Mandeville, Joseph B.; ...

    2014-06-14

    We report that glucose is the principal source of energy for the brain and yet the dynamic response of glucose utilization to changes in brain activity is still not fully understood. Positron emission tomography (PET) allows quantitative measurement of glucose metabolism using 2-[18F]-fluorodeoxyglucose (FDG). However, FDG PET in its current form provides an integral (or average) of glucose consumption over tens of minutes and lacks the temporal information to capture physiological alterations associated with changes in brain activity induced by tasks or drug challenges. Traditionally, changes in glucose utilization are inferred by comparing two separate scans, which significantly limits themore » utility of the method. We report a novel method to track changes in FDG metabolism dynamically, with higher temporal resolution than exists to date and within a single session. Using a constant infusion of FDG, we demonstrate that our technique (termed fPET-FDG) can be used in an analysis pipeline similar to fMRI to define within-session differential metabolic responses. We use visual stimulation to demonstrate the feasibility of this method. Ultimately, this new method has a great potential to be used in research protocols and clinical settings since fPET-FDG imaging can be performed with most PET scanners and data acquisition and analysis are straightforward. fPET-FDG is a highly complementary technique to MRI and provides a rich new way to observe functional changes in brain metabolism.« less

  12. Dynamic Functional Imaging of Brain Glucose Utilization using fPET-FDG

    PubMed Central

    Villien, Marjorie; Wey, Hsiao-Ying; Mandeville, Joseph B.; Catana, Ciprian; Polimeni, Jonathan R.; Sander, Christin Y.; Zürcher, Nicole R.; Chonde, Daniel B.; Fowler, Joanna S.; Rosen, Bruce R.; Hooker, Jacob M.

    2014-01-01

    Glucose is the principal source of energy for the brain and yet the dynamic response of glucose utilization to changes in brain activity is still not fully understood. Positron emission tomography (PET) allows quantitative measurement of glucose metabolism using 2-[18F]-fluorodeoxyglucose (FDG). However, FDG PET in its current form provides an integral (or average) of glucose consumption over tens of minutes and lacks the temporal information to capture physiological alterations associated with changes in brain activity induced by tasks or drug challenges. Traditionally, changes in glucose utilization are inferred by comparing two separate scans, which significantly limits the utility of the method. We report a novel method to track changes in FDG metabolism dynamically, with higher temporal resolution than exists to date and within a single session. Using a constant infusion of FDG, we demonstrate that our technique (termed fPET-FDG) can be used in an analysis pipeline similar to fMRI to define within-session differential metabolic responses. We use visual stimulation to demonstrate the feasibility of this method. This new method has a great potential to be used in research protocols and clinical settings since fPET-FDG imaging can be performed with most PET scanners and data acquisition and analysis is straightforward. fPET-FDG is a highly complementary technique to MRI and provides a rich new way to observe functional changes in brain metabolism. PMID:24936683

  13. Dynamic functional imaging of brain glucose utilization using fPET-FDG.

    PubMed

    Villien, Marjorie; Wey, Hsiao-Ying; Mandeville, Joseph B; Catana, Ciprian; Polimeni, Jonathan R; Sander, Christin Y; Zürcher, Nicole R; Chonde, Daniel B; Fowler, Joanna S; Rosen, Bruce R; Hooker, Jacob M

    2014-10-15

    Glucose is the principal source of energy for the brain and yet the dynamic response of glucose utilization to changes in brain activity is still not fully understood. Positron emission tomography (PET) allows quantitative measurement of glucose metabolism using 2-[(18)F]-fluorodeoxyglucose (FDG). However, FDG PET in its current form provides an integral (or average) of glucose consumption over tens of minutes and lacks the temporal information to capture physiological alterations associated with changes in brain activity induced by tasks or drug challenges. Traditionally, changes in glucose utilization are inferred by comparing two separate scans, which significantly limits the utility of the method. We report a novel method to track changes in FDG metabolism dynamically, with higher temporal resolution than exists to date and within a single session. Using a constant infusion of FDG, we demonstrate that our technique (termed fPET-FDG) can be used in an analysis pipeline similar to fMRI to define within-session differential metabolic responses. We use visual stimulation to demonstrate the feasibility of this method. This new method has a great potential to be used in research protocols and clinical settings since fPET-FDG imaging can be performed with most PET scanners and data acquisition and analysis are straightforward. fPET-FDG is a highly complementary technique to MRI and provides a rich new way to observe functional changes in brain metabolism.

  14. Cardiac Magnetic Resonance for Evaluating Catheter Related FDG Avidity

    PubMed Central

    Gage, Kenneth L.; Berman, Claudia G.; Montilla-Soler, Jaime L.

    2016-01-01

    A 53-year-old female with a history of metastatic left arm melanoma presented for F(18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) which showed a moderately FDG avid focus at her port catheter tip near the cavoatrial junction. Although catheter tip related FDG avidity has previously been suggested to be bland thrombus or infection, melanoma can metastasize to unusual locations including the superior vena cava. In addition, the patient had an elevated risk of anticoagulation due to a history of hemorrhagic brain metastases. Therefore, confirmatory cardiac magnetic resonance (CMR) was obtained and findings were consistent with bland catheter-related thrombus. PMID:27867676

  15. Comparison of F-18 Fluorodeoxyglucose and F-18 Fluorothymidine Positron Emission Tomography in Differentiating Radiation Necrosis from Recurrent Glioma

    PubMed Central

    Enslow, Michael S.; Zollinger, Lauren V.; Morton, Kathryn A.; Kadrmas, Dan J.; Butterfield, Regan I.; Christian, Paul E.; Boucher, Kenneth M.; Heilbrun, Marta E.; Jensen, Randy L.; Hoffman, John M.

    2012-01-01

    Purpose of the Report The objective was to compare F-18 fluorodeoxyglucose (FDG) and F-18 fluorothymidine (FLT) positron emission tomography (PET) in differentiating radiation necrosis from recurrent glioma. Materials and methods Visual and quantitative analyses were derived from static FDG PET and static and dynamic FLT PET in 15 patients with suspected recurrence of treated ≥ grade II glioma with a new focus of Gd-contrast enhancement on MRI. For FDG PET, SUVmax and the ratio of lesion SUVmax to the SUVmean of contralateral white matter were measured. For FLT PET, SUVmax and Patlak-derived metabolic flux parameter Kimax were measured for the same locus. A 5-point visual confidence scale was applied to FDG PET and FLT PET. ROC analysis was applied to visual and quantitative results. Differences between recurrent tumor and radiation necrosis were tested by Kruskal-Wallis analysis. Based on follow-up Gd-MRI imaging, lesion-specific recurrent tumor was defined as a definitive increase in size of the lesion, and radiation necrosis as stability or regression. Results For FDG SUVmax, FDG ratio lesion:white matter and FLT Kimax, there was a significant difference between mean values for recurrent tumor and radiation necrosis. Recurrent tumor was best identified by FDG ratio of lesion:contralateral normal white matter (AUC 0.98, CI 0.91–1.00, sens. 100%, spec. 75% for an optimized cut-off value of 1.82). Conclusion Both quantitative and visual determinations allow accurate differentiation between recurrent glioma and radiation necrosis by both FDG and FLT PET. In this small series, FLT PET offers no advantage over FDG PET. PMID:22889774

  16. Ictal onset zone and seizure propagation delineated on ictal F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Tripathi, Madhavi; Tripathi, Manjari; Garg, Ajay; Damle, Nishikant; Bal, Chandrasekhar

    2016-01-01

    The present case highlights the utility of ictal F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in delineating the seizure onset zone in a child with complex partial seizures. Although F-18 FDG PET has been successfully used to delineate interictal hypometabolism, planned ictal FDG PET, in cases with prolonged seizure activity, can provide better spatial resolution than single-photon emission CT by delineating the seizure onset zone and propagation pathway.

  17. Long-term effects of 'ecstasy' abuse on the human brain studied by FDG PET.

    PubMed

    Buchert, R; Obrocki, J; Thomasius, R; Väterlein, O; Petersen, K; Jenicke, L; Bohuslavizki, K H; Clausen, M

    2001-08-01

    The popular recreational drug, 'ecstasy', mainly contains 3,4-methylenedioxymethamphetamine (MDMA) as the psychotropic agent. MDMA is suspected of causing neurotoxic lesions to the serotonergic system as demonstrated by animal studies, examinations of human cerebrospinal fluid, and the first positron emission tomography (PET) studies using the serotonin transporter ligand [11C]-McN5652. Damage of serotonergic afferents might mediate long-lasting alterations of cerebral glucose metabolism as a secondary effect. To study a relationship between ecstasy use and long-lasting alterations, PET using 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) was performed in 93 ecstasy users and 27 subjects without any known history of illicit-drug abuse. As an index of glucose metabolism, mean normalized FDG uptake was determined in both groups using a computerized brain atlas, and was compared for a selected number of brain regions. FDG uptake was normalized in each individual by dividing local FDG uptake by the maximum FDG uptake in the individual's brain. Within the group of ecstasy users we examined the relationship between FDG uptake and cumulative ecstasy dose, time since last ecstasy ingestion at the time of PET scanning, and age at first ecstasy use, respectively. Normalized FDG uptake was reduced within the striatum and amygdala of ecstasy users when compared to controls. No statistically significant correlation of the FDG uptake and the cumulative dose of ecstasy was detected. A positive correlation was found in the cingulate between FDG uptake and the time since last ecstasy ingestion. As compared to the control group, normalized FDG uptake in the cingulate was reduced in ecstasy users who took ecstasy during the last 6 months, while it was elevated in former ecstasy users who did not consume ecstasy for more than 1 year. FDG uptake was significantly more affected in ecstasy users who started to consume ecstasy before the age of 18 years. In conclusion, ecstasy abuse causes long

  18. Concurrent Low Brain and High Liver Uptake on FDG PET Are Associated with Cardiovascular Risk Factors

    PubMed Central

    Nam, Hyun-Yeol; Jun, Sungmin; Pak, Kyoungjune

    2017-01-01

    Objective Concurrent low brain and high liver uptake are sometimes observed on fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). We investigated the potential clinical significance of this uptake pattern related to metabolic syndrome (MS). Materials and Methods We retrospectively reviewed data from 264 consecutive males who had undergone general health check-ups, including FDG PET/CT scans. After an overnight fast, the men had their peripheral blood drawn and the levels of various laboratory parameters measured; an FDG PET/CT scan was performed on the same day. We measured the maximum standardized uptake values of the brain and liver from regions of interest manually placed over the frontal cortex at the level of the centrum semiovale and the right lobe of the liver parenchyma, respectively. Results Fasting blood glucose (FBG; odds ratio [OR] = 1.063, p < 0.001) and glycated hemoglobin (HbA1c; OR = 3.634, p = 0.010) were the strongest predictive factors for low brain FDG uptake, whereas waist circumference (OR = 1.200, p < 0.001) and γ-glutamyl transpeptidase (OR = 1.012, p = 0.001) were the strongest predictive factors for high liver uptake. Eleven subjects (4.2%) showed concurrent low brain and high liver FDG uptake, and all but one of these subjects (90.9%) had MS. Systolic blood pressure, waist circumference, FBG, triglyceride, alanine aminotransferase, insulin resistance (measured by homeostasis model assessment), insulin, HbA1c, and body mass index were higher in subjects with this FDG uptake pattern than in those without (all, p < 0.001). Conclusion Concurrent low brain and high liver FDG uptake were closely associated with MS. Moreover, subjects with this pattern had higher values for various cardiovascular risk factors than did those without. PMID:28246520

  19. Asymmetrical F-18 Flurorodeoxyglucose uptake in the breasts: A dilemma solved by patient history.

    PubMed

    Gupta, Ravi Kant; Tripathi, Madhavi; Sahoo, Manas Kumar; Nazar, Aftab Hasan; Agarwal, Krishankant; Kumar, Kunal; Damle, Nishikant; Bal, Chandrasekhar

    2016-01-01

    The present case highlights the importance of history taking in solving the dilemmas of variant F-18 FDG uptake on PET/CT. Asymmetrically increased, abnormal looking, FDG uptake in the right breast of our patient was related to her breast feeding practice. Because of personal preference the patient suckled her child from the right breast only. This resulted in asymmetry of size, increase in glandular breast parenchyma and FDG uptake in the breast that was suckled.

  20. FDG PET brain scan demonstrated glucose hypometabolism of bilateral caudate nuclei and putamina in a patient with chorea-acanthocytosis.

    PubMed

    Cui, Ruixue; You, Hui; Niu, Na; Li, Fang

    2015-12-01

    Chorea-acanthocytosis is 1 type of neuroacanthocytosis that is a group of rare, hereditary neurodegenerative disorders. We presented a brain FDG PET finding of a 31-year-old woman with chorea-acanthocytosis. The images demonstrated significant hypometabolism in bilateral caudate nuclei and putamina. The finding of FDG PET is more prominent than that of MRI. Another interesting observation is the mildly increased FDG uptake in pituitary gland, although its relationship with the disease is unclear.

  1. Pilot study of F(18)-Fluorodeoxyglucose Positron Emission Tomography/computerised tomography in Wilms' tumour: correlation with conventional imaging, pathology and immunohistochemistry.

    PubMed

    Begent, Joanna; Sebire, Neil J; Levitt, Gill; Brock, Penelope; Jones, Kathy Pritchard; Ell, Peter; Gordon, Isky; Anderson, John

    2011-02-01

    Wilms' tumour is the second most common paediatric solid tumour. Prognosis is good although higher stage disease carries significant mortality and treatment related morbidity. In the UK, risk stratification is based on histological response to pre-operative chemotherapy. F(18)-Fluorodeoxyglucose Positron Emission Tomography (F(18)FDG-PET) is an emerging functional imaging technique in paediatric oncology. Little is known about the relationship between F(18)FDG-PET images and the disease process of Wilms' tumour. We performed F(18)FDG-PET/CT scans in seven children with Wilms' tumour after induction chemotherapy, immediately before surgery. The standard uptake values (SUV) of F(18)FDG-PET/CT images were related to conventional imaging and histopathological findings. In total seven children were studied. F(18)FDG-PET/CT was consistently safely performed. All tumours showed F(18)FDG activity. Four tumours had activity with SUV/bw max >5 g/ml. Histological examination of these active areas revealed viable anaplastic Wilms' tumour. Furthermore, in these four tumours GLUT-1 and Ki67 immunostaining was strongly positive. Three further tumours demonstrated lower uptake (SUV/bw max <5 g/ml), which represented areas of microscopic foci of residual viable tumour mixed with post chemotherapy change. Metastatic disease was F(18)FDG avid in two of four children with stage four diseases. In conclusion, following chemotherapy, active Wilms' tumour is F(18)FDG avid and higher SUV was seen in histologically high risk disease.

  2. Diffuse FDG renal uptake in lymphoma.

    PubMed

    Navalkissoor, Shaunak; Szyszko, Teresa; Gnanasegaran, Gopinath; Nunan, Thomas

    2010-10-01

    In patients presenting with acute renal failure and known/suspected lymphoma, the diagnosis of diffuse renal involvement is important, as there is potential for rapid resolution with chemotherapy. Although FDG is excreted through the kidneys and focal renal disease may be difficult to identify, diffuse renal FDG is more easily recognized and is always abnormal. We report a patient presenting with acute renal failure and suspected lymphoma. F-18 FDG PET/CT study demonstrated diffuse increased FDG uptake in bilaterally enlarged kidneys. Following 1 cycle of chemotherapy, the renal function normalized. An interim F-18 FDG PET/CT demonstrated normal size and FDG uptake within both kidneys.

  3. F-18 fluorodeoxyglucose PET/CT and post hoc PET/MRI in a case of primary meningeal melanomatosis.

    PubMed

    Lee, Hong Je; Ahn, Byeong-Cheol; Hwang, Seong Wook; Cho, Suk Kyong; Kim, Hae Won; Lee, Sang-Woo; Hwang, Jeong-Hyun; Lee, Jaetae

    2013-01-01

    Primary meningeal melanomatosis is a rare, aggressive variant of primary malignant melanoma of the central nervous system, which arises from melanocytes within the leptomeninges and carries a poor prognosis. We report a case of primary meningeal melanomatosis in a 17-year-old man, which was diagnosed with (18)F-fluorodeoxyglucose (F-18 FDG) PET/CT, and post hoc F-18 FDG PET/MRI fusion images. Whole-body F-18 FDG PET/CT was helpful in ruling out the extracranial origin of melanoma lesions, and in assessing the therapeutic response. Post hoc PET/MRI fusion images facilitated the correlation between PET and MRI images and demonstrated the hypermetabolic lesions more accurately than the unenhanced PET/CT images. Whole body F-18 FDG PET/CT and post hoc PET/MRI images might help clinicians determine the best therapeutic strategy for patients with primary meningeal melanomatosis.

  4. Short-Term Practice Effects and Brain Hypometabolism: Preliminary Data from an FDG PET Study.

    PubMed

    Duff, Kevin; Horn, Kevin P; Foster, Norman L; Hoffman, John M

    2015-05-01

    Practice effects are improvements in cognitive test scores due to repeated exposure to the same tests. Typically viewed as error, short-term practice effects have been shown to provide valuable clinical information about diagnosis, prognosis, and treatment outcomes in older patients with mild cognitive impairments. This study examined short-term practice effects across one week and brain hypometabolism on fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in 25 older adults (15 intact, 10 Mild Cognitive Impairment). Averaged cerebral brain metabolism on FDG PET was correlated with multiple cognitive scores at baseline in those with Mild Cognitive Impairment, and short-term practice effects accounted for additional variance in these same subjects. The relationship between brain metabolism and cognition (either at baseline or practice effects) was minimal in the intact individuals. Although needing replication in larger samples, short-term practice effects on tests of executive functioning and memory may provide valuable information about biomarkers of Alzheimer's disease.

  5. Prediction of standard-dose brain PET image by using MRI and low-dose brain [{sup 18}F]FDG PET images

    SciTech Connect

    Kang, Jiayin; Gao, Yaozong; Shi, Feng; Lalush, David S.; Lin, Weili; Shen, Dinggang

    2015-09-15

    Purpose: Positron emission tomography (PET) is a nuclear medical imaging technology that produces 3D images reflecting tissue metabolic activity in human body. PET has been widely used in various clinical applications, such as in diagnosis of brain disorders. High-quality PET images play an essential role in diagnosing brain diseases/disorders. In practice, in order to obtain high-quality PET images, a standard-dose radionuclide (tracer) needs to be used and injected into a living body. As a result, it will inevitably increase the patient’s exposure to radiation. One solution to solve this problem is predicting standard-dose PET images using low-dose PET images. As yet, no previous studies with this approach have been reported. Accordingly, in this paper, the authors propose a regression forest based framework for predicting a standard-dose brain [{sup 18}F]FDG PET image by using a low-dose brain [{sup 18}F]FDG PET image and its corresponding magnetic resonance imaging (MRI) image. Methods: The authors employ a regression forest for predicting the standard-dose brain [{sup 18}F]FDG PET image by low-dose brain [{sup 18}F]FDG PET and MRI images. Specifically, the proposed method consists of two main steps. First, based on the segmented brain tissues (i.e., cerebrospinal fluid, gray matter, and white matter) in the MRI image, the authors extract features for each patch in the brain image from both low-dose PET and MRI images to build tissue-specific models that can be used to initially predict standard-dose brain [{sup 18}F]FDG PET images. Second, an iterative refinement strategy, via estimating the predicted image difference, is used to further improve the prediction accuracy. Results: The authors evaluated their algorithm on a brain dataset, consisting of 11 subjects with MRI, low-dose PET, and standard-dose PET images, using leave-one-out cross-validations. The proposed algorithm gives promising results with well-estimated standard-dose brain [{sup 18}F]FDG PET

  6. Validation of true low-dose (18)F-FDG PET of the brain.

    PubMed

    Fällmar, David; Lilja, Johan; Kilander, Lena; Danfors, Torsten; Lubberink, Mark; Larsson, Elna-Marie; Sörensen, Jens

    2016-01-01

    The dosage of (18)F-FDG must be sufficient to ensure adequate PET image quality. For younger patients and research controls, the lowest possible radiation dose should be used. The purpose of this study was to find a protocol for FDG-PET of the brain with reduced radiation dose and preserved quantitative characteristics. Eight patients with neurodegenerative disorders and nine controls (n=17) underwent FDG-PET/CT twice on separate occasions, first with normal-dose (3 MBq/kg), and second with low-dose (0.75 MBq/kg, 25% of the original). Five additional controls (total n=22) underwent FDG-PET twice, using normal-dose and ultra-low-dose (0.3 MBq/kg, 10% of original). All subjects underwent MRI. Ten-minute summation images were spatially normalized and intensity normalized. Regional standard uptake value ratios (SUV-r) were calculated using an automated atlas. SUV-r values from the normal- and low-dose images were compared pairwise. No clinically significant bias was found in any of the three groups. The mean absolute difference in regional SUV-r values was 0.015 (1.32%) in controls and 0.019 (1.67%) in patients. The ultra-low-dose protocol produced a slightly higher mean difference of 0.023 (2.10%). The main conclusion is that 0.75 MBq/kg (56 MBq for a 75-kg subject) is a sufficient FDG dose for evaluating regional SUV-ratios in brain PET scans in adults with or without neurodegenerative disease, resulting in a reduction of total PET/CT effective dose from 4.54 to 1.15 mSv. The ultra-low-dose (0.5 mSv) could be useful in research studies requiring serial PET in healthy controls or children.

  7. Validation of true low-dose 18F-FDG PET of the brain

    PubMed Central

    Fällmar, David; Lilja, Johan; Kilander, Lena; Danfors, Torsten; Lubberink, Mark; Larsson, Elna-Marie; Sörensen, Jens

    2016-01-01

    The dosage of 18F-FDG must be sufficient to ensure adequate PET image quality. For younger patients and research controls, the lowest possible radiation dose should be used. The purpose of this study was to find a protocol for FDG-PET of the brain with reduced radiation dose and preserved quantitative characteristics. Eight patients with neurodegenerative disorders and nine controls (n=17) underwent FDG-PET/CT twice on separate occasions, first with normal-dose (3 MBq/kg), and second with low-dose (0.75 MBq/kg, 25% of the original). Five additional controls (total n=22) underwent FDG-PET twice, using normal-dose and ultra-low-dose (0.3 MBq/kg, 10% of original). All subjects underwent MRI. Ten-minute summation images were spatially normalized and intensity normalized. Regional standard uptake value ratios (SUV-r) were calculated using an automated atlas. SUV-r values from the normal- and low-dose images were compared pairwise. No clinically significant bias was found in any of the three groups. The mean absolute difference in regional SUV-r values was 0.015 (1.32%) in controls and 0.019 (1.67%) in patients. The ultra-low-dose protocol produced a slightly higher mean difference of 0.023 (2.10%). The main conclusion is that 0.75 MBq/kg (56 MBq for a 75-kg subject) is a sufficient FDG dose for evaluating regional SUV-ratios in brain PET scans in adults with or without neurodegenerative disease, resulting in a reduction of total PET/CT effective dose from 4.54 to 1.15 mSv. The ultra-low-dose (0.5 mSv) could be useful in research studies requiring serial PET in healthy controls or children. PMID:27766185

  8. Symmetric increased skeletal muscular uptake of F-18 fluoro-deoxyglucose: A clue for the diagnosis of Graves' disease.

    PubMed

    Santhosh, Sampath; Mittal, Bhagwant Rai; Kashyap, Raghava; Bhattacharya, Anish; Singh, Baljinder

    2011-07-01

    F-18 fluoro-deoxyglucose (FDG) uptake in the thyroid and thymus is well reported in patients with Graves' disease. Incidental skeletal muscle uptake has also been reported in other non-musculoskeletal (benign and malignant) pathologies. We report a patient of Graves' disease showing symmetrical skeletal muscle uptake but no thyroidal or thymus uptake of FDG.

  9. F-18 SRA in flight

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's Dryden Flight Research Center, Edwards, California, is using this early-model F-18 Hornet as a flying research platform to evaluate a number of emerging technologies in aircraft control and information systems. The Systems Research Aircraft, a pre-production two-seat version of the twin-engine tactical fighter aircraft, has been extensively modified for its research role. Among projects flown on the plane are experiments to evaluate fiber optics for flight-critical control systems, advanced air data acquisition systems, and electrically-powered flight control actuators which do not require connection to the aircraft central hydraulic system. The new technologies could lead to lighter and more efficient aircraft designs with higher performance and greater safety.

  10. Positron Emission Tomography Using Fluorine F 18 EF5 to Find Oxygen in Tumor Cells of Patients Who Are Undergoing Surgery or Biopsy for Newly Diagnosed Brain Tumors

    ClinicalTrials.gov

    2013-01-15

    Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Anaplastic Oligodendroglioma; Adult Brain Stem Glioma; Adult Central Nervous System Germ Cell Tumor; Adult Choroid Plexus Tumor; Adult Craniopharyngioma; Adult Diffuse Astrocytoma; Adult Ependymoblastoma; Adult Ependymoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Grade I Meningioma; Adult Grade II Meningioma; Adult Grade III Meningioma; Adult Medulloblastoma; Adult Meningeal Hemangiopericytoma; Adult Mixed Glioma; Adult Myxopapillary Ependymoma; Adult Oligodendroglioma; Adult Pilocytic Astrocytoma; Adult Pineoblastoma; Adult Pineocytoma; Adult Subependymoma; Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Meningeal Melanocytoma

  11. FDG-PET imaging in mild traumatic brain injury: a critical review.

    PubMed

    Byrnes, Kimberly R; Wilson, Colin M; Brabazon, Fiona; von Leden, Ramona; Jurgens, Jennifer S; Oakes, Terrence R; Selwyn, Reed G

    2014-01-09

    Traumatic brain injury (TBI) affects an estimated 1.7 million people in the United States and is a contributing factor to one third of all injury related deaths annually. According to the CDC, approximately 75% of all reported TBIs are concussions or considered mild in form, although the number of unreported mild TBIs (mTBI) and patients not seeking medical attention is unknown. Currently, classification of mTBI or concussion is a clinical assessment since diagnostic imaging is typically inconclusive due to subtle, obscure, or absent changes in anatomical or physiological parameters measured using standard magnetic resonance (MR) or computed tomography (CT) imaging protocols. Molecular imaging techniques that examine functional processes within the brain, such as measurement of glucose uptake and metabolism using [(18)F]fluorodeoxyglucose and positron emission tomography (FDG-PET), have the ability to detect changes after mTBI. Recent technological improvements in the resolution of PET systems, the integration of PET with magnetic resonance imaging (MRI), and the availability of normal healthy human databases and commercial image analysis software contribute to the growing use of molecular imaging in basic science research and advances in clinical imaging. This review will discuss the technological considerations and limitations of FDG-PET, including differentiation between glucose uptake and glucose metabolism and the significance of these measurements. In addition, the current state of FDG-PET imaging in assessing mTBI in clinical and preclinical research will be considered. Finally, this review will provide insight into potential critical data elements and recommended standardization to improve the application of FDG-PET to mTBI research and clinical practice.

  12. FDG-PET imaging in mild traumatic brain injury: a critical review

    PubMed Central

    Byrnes, Kimberly R.; Wilson, Colin M.; Brabazon, Fiona; von Leden, Ramona; Jurgens, Jennifer S.; Oakes, Terrence R.; Selwyn, Reed G.

    2013-01-01

    Traumatic brain injury (TBI) affects an estimated 1.7 million people in the United States and is a contributing factor to one third of all injury related deaths annually. According to the CDC, approximately 75% of all reported TBIs are concussions or considered mild in form, although the number of unreported mild TBIs (mTBI) and patients not seeking medical attention is unknown. Currently, classification of mTBI or concussion is a clinical assessment since diagnostic imaging is typically inconclusive due to subtle, obscure, or absent changes in anatomical or physiological parameters measured using standard magnetic resonance (MR) or computed tomography (CT) imaging protocols. Molecular imaging techniques that examine functional processes within the brain, such as measurement of glucose uptake and metabolism using [18F]fluorodeoxyglucose and positron emission tomography (FDG-PET), have the ability to detect changes after mTBI. Recent technological improvements in the resolution of PET systems, the integration of PET with magnetic resonance imaging (MRI), and the availability of normal healthy human databases and commercial image analysis software contribute to the growing use of molecular imaging in basic science research and advances in clinical imaging. This review will discuss the technological considerations and limitations of FDG-PET, including differentiation between glucose uptake and glucose metabolism and the significance of these measurements. In addition, the current state of FDG-PET imaging in assessing mTBI in clinical and preclinical research will be considered. Finally, this review will provide insight into potential critical data elements and recommended standardization to improve the application of FDG-PET to mTBI research and clinical practice. PMID:24409143

  13. [(18)F]FDG-PET Combined with MRI Elucidates the Pathophysiology of Traumatic Brain Injury in Rats.

    PubMed

    Brabazon, Fiona; Wilson, Colin M; Shukla, Dinesh K; Mathur, Sanjeev; Jaiswal, Shalini; Bermudez, Sara; Byrnes, Kimberly R; Selwyn, Reed

    2017-03-01

    Non-invasive measurements of brain metabolism using (18)F-fluorodeoxyglucose (FDG) with positron emission tomography (PET) may provide important information about injury severity following traumatic brain injury (TBI). There is growing interest in the potential of combining functional PET imaging with anatomical and functional magnetic resonance imaging (MRI). This study aimed to investigate the effectiveness of combining clinically available FDG-PET with T2 and diffusion MR imaging, with a particular focus on inflammation and the influence of glial alterations after injury. Adult male Sprague Dawley rats underwent a moderate controlled cortical impact (CCI) injury followed by FDG-PET, MRI, and histological evaluation. FDG uptake showed significant alterations in the corpus callosum, hippocampus, and amygdala after TBI, demonstrating that a relatively "focal" CCI injury can result in global alterations. Analysis of MRI T2 intensity and apparent diffusion coefficient (ADC) also showed significant alterations in these regions to include cytotoxic and vasogenic edema. Histology showed increased glial activation in the corpus callosum and hippocampus that was associated with increased FDG uptake at sub-acute time-points. Glial activation was not detected in the amygdala but neuronal damage was evident, as the amygdala was the only region to show a reduction in both FDG uptake and ADC at sub-acute time-points. Overall, FDG-PET detected glial activation but was confounded by the presence of cell damage, whereas MRI consistently detected cell damage but was confounded by glial activation. These results demonstrate that FDG-PET and MRI can be used together to improve our understanding of the complex alterations in the brain after TBI.

  14. Brain FDG-PET metabolic abnormalities in Macrophagic Myofasciitis: Are They Stable?

    PubMed

    Blanc-Durand, Paul; Van Der Gucht, Axel; Aoun Sebaiti, Mehdi; Abulizi, Mukedaisi; Authier, Francois-Jérome; Itti, Emmanuel

    2017-03-16

    We address this letter in addition to our recent published study (1). The aim is to add some insight to the evolution of the brain abnormalities that are observed with macrophagic myofasciitis (MMF). MMF is a chronic disease whom evolution is slow and symptoms first may occurs from months to year after a vaccination containing aluminium hydroxid adjuvants (2). Nevertheless, its evolution is not fully understood or known. MMF associated cognitive dysfunction (MACD) is based on a tripod combining dysexecutive syndrom, visual memory impairment and interhemispheric disconnection. One pilot study suggest that MACD appears clinically stable over time (3). One recent study evaluating a support vector machine classifier also suggest that the abnormalities observed with 18-fluorodeoxyglose positron emission tomography ((18)F-FDG PET) may be sensitive and could be used to monitor patients. The study population comes from cohort followed in our Reference Center for Rare Neuromuscular Diseases and data were collected retrospectively. Among those patients, 15 had two consecutives (18)F-FDG PET brain acquisitions (median age 42.1 [range 20.9 to 63.5]) following the same brain protocol acquisition as previously described (1). Median time duration between the two examinations was 2.3 years (range 0.5 to 4]. Using analysis of covariance and negative or positive contrast in SPM12, a t-test mask was generated from the comparison between the two means of the first cerebral (18)F-FDG PET images and between the mean of the second acquisition. Results of the comparison were collected at a P-value < 0.005 at the voxel level, for clusters k ≥ 200 voxels (corrected for cluster volume) with adjustment for age. Brain abnormalities maps didn't show any statistical difference between the two examinations confirming the idea that MMF is a slowly or not progressive disease and it is in concordance with the fact that neurological symptoms even if fluctuate do not worsen over time (nor ameliorate).

  15. F-18 SRA during flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This bright blue-and-white twin-jet aircraft may look like an ordinary F/A-18 Hornet fighter, but inside its a different bird. Currently being flown by NASA's Dryden Flight Research Center, Edwards, California, in a multi-year, joint NASA/DOD/industry program, the former Navy fighter has been modified into a unique Systems Research Aircraft (SRA) to investigate a host of new technologies in the areas of flight controls, airdata sensing and advanced computing. One of the more than 20 experiments being tested aboard the SRA F-18 is an advanced air data sensing system which uses a group of pressure taps flush-mounted on the forward fuselage to measure both altitude and wind speed and direction--critical data for flight control and research investigations. The Real-Time Flush Air Data Sensing system concept is being evaluated for possible use on the X-33 resuable space-launch vehicle. The primary goal of the SRA program is to validate through flight research cutting-edge technologies which could benefit future aircraft and spacecraft by improving efficiency and performance, reducing weight and complexity, with a resultant reduction on development and operational costs.

  16. F-18 SRA during flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Aeronautics and Space Administration's Systems Research Aircraft (SRA), a highly modified F-18 jet fighter, is seen here during a recent research flight. The former Navy aircraft is being flown by NASA's Dryden Flight Research Center at Edwards Air Force Base, California, to evaluate a number of experimental aerospace technologies in a multi-year, joint NASA/DOD/industry program. Among the more than 20 experiments being flight-tested were several involving fiber optic sensor systems. Experiments developed by McDonnell-Douglas and Lockheed-Martin centered on installation and maintenace techniques for various types of fiber-optic hardware proposed for use in military and commercial aircraft, while a Parker-Hannifin experiment focused in alternative fiber-optic designs for position measurement sensors as well as operational experience in handling optical sensor systems. Other experiments being flown on this testbed aircraft include electronically-controlled control surface actuators, flush air data collection systems, 'smart' skin antennae and laser-based systems. Incorporation of one or more of these technologies in future aircraft and spacecraft could result in signifigant savings in weight, maintenance and overall cost.

  17. Bitemporal hypometabolism in Creutzfeldt-Jakob Disease measured by positron emission tomography with (F-18)2-fluorodeoxyglucose

    SciTech Connect

    Friedland, R.P.; Budinger, T.F.; Prusiner, S.B.; Jagust, W.J.

    1984-01-01

    It is well established that Creutzfeldt-Jakob Disease (CJD) is caused by a slow infectious agent similar to the scrapie prion. However, the pathogenesis of this infection is poorly understood. Positron emission tomography (PET) was performed on a 54 year old male subject with autopsy confirmed CJD using (F-18)2-fluorodeoxyglucose (FDG) and the Donner 280-crystal tomograph. An x-ray computed tomographic study of the brain performed 4 days prior to PET was normal. In the PET study the frontal to temporal cortex difference of activity densities was 30% on the left and 12% on the right, reflecting temporal hypometabolism. The left-right temporal cortex difference of activity density was 25%, documenting marked hemispheric asymmetry. These findings are similar to those previously obtained in PET-FDG studies of patients with clinically defined Alzheimer's Disease (AD) and are distinctly different from PET-FDG finding in patients with other dementing illnesses or in healthy aged subjects. Recent work has demonstrated extensive biological similarities between CJD, scrapie and AD. The similarities in the regional metabolic alterations between CJD and AD provide additional evidence for the hypothesis that AD is caused by a slow infectious (prion-like) pathogen.

  18. Striatofrontal Deafferentiation in MSA-P: Evaluation with [18F]FDG Brain PET

    PubMed Central

    Kim, Hae Won; Oh, Minyoung; Oh, Jungsu S.; Oh, Seung Jun; Lee, Sang Ju; Chung, Sun Ju; Kim, Jae Seung

    2017-01-01

    Background Although cognitive impairment is not a consistent feature of multiple system atrophy (MSA), increasing evidence suggests that cognitive impairment is common in MSA with predominant parkinsonism (MSA-P). It is assumed that the cognitive impairment in MSA-P is caused by the striatal dysfunction and disruption of striatofrontal connections. The aim of this study was to evaluate the relationship between regional glucose metabolism in the frontal cortex and striatum in patients with MSA-P using [18F]FDG brain PET. Methods Twenty-nine patients with MSA-P and 28 healthy controls underwent [18F]FDG brain PET scan. The [18F]FDG brain PET images were semiquantitatively analyzed on the basis of a template in standard space. The regional glucose metabolism of the cerebral cortex and striatum were compared between MSA-P and healthy control groups. The correlations between age, symptom duration, H&Y stage, UPDRS III score, MMSE score, and glucose metabolism in the cerebellum and striatum to glucose metabolism in the frontal cortex were evaluated by multivariate analysis. Results The glucose metabolism in the frontal cortex and striatum in MSA-P patients were significantly lower than those in healthy controls. Glucose metabolism in the striatum was the most powerful determinant of glucose metabolism in the frontal cortex in MSA-P. Only age and glucose metabolism in the cerebellum were independent variables affecting the glucose metabolism in the frontal cortex in healthy controls. Conclusion The decrease in frontal glucose metabolism in MSA-P is related to the decrease in striatal glucose metabolism. This result provided evidence of striatofrontal deafferentiation in patients with MSA-P. PMID:28085923

  19. Brain (18)F-FDG PET Metabolic Abnormalities in Patients with Long-Lasting Macrophagic Myofascitis.

    PubMed

    Van Der Gucht, Axel; Aoun Sebaiti, Mehdi; Guedj, Eric; Aouizerate, Jessie; Yara, Sabrina; Gherardi, Romain K; Evangelista, Eva; Chalaye, Julia; Cottereau, Anne-Ségolène; Verger, Antoine; Bachoud-Levi, Anne-Catherine; Abulizi, Mukedaisi; Itti, Emmanuel; Authier, François-Jérôme

    2017-03-01

    The aim of this study was to characterize brain metabolic abnormalities in patients with macrophagic myofascitis (MMF) and the relationship with cognitive dysfunction through the use of PET with (18)F-FDG. Methods:(18)F-FDG PET brain imaging and a comprehensive battery of neuropsychological tests were performed in 100 consecutive MMF patients (age [mean ± SD], 45.9 ± 12 y; 74% women). Images were analyzed with statistical parametric mapping (SPM12). Through the use of analysis of covariance, all (18)F-FDG PET brain images of MMF patients were compared with those of a reference population of 44 healthy subjects similar in age (45.4 ± 16 y; P = 0.87) and sex (73% women; P = 0.88). The neuropsychological assessment identified 4 categories of patients: those with no significant cognitive impairment (n = 42), those with frontal subcortical (FSC) dysfunction (n = 29), those with Papez circuit dysfunction (n = 22), and those with callosal disconnection (n = 7). Results: In comparison with healthy subjects, the whole population of patients with MMF exhibited a spatial pattern of cerebral glucose hypometabolism (P < 0.001) involving the occipital lobes, temporal lobes, limbic system, cerebellum, and frontoparietal cortices, as shown by analysis of covariance. The subgroup of patients with FSC dysfunction exhibited a larger extent of involved areas (35,223 voxels vs. 13,680 voxels in the subgroup with Papez circuit dysfunction and 5,453 voxels in patients without cognitive impairment). Nonsignificant results were obtained for the last subgroup because of its small population size. Conclusion: Our study identified a peculiar spatial pattern of cerebral glucose hypometabolism that was most marked in MMF patients with FSC dysfunction. Further studies are needed to determine whether this pattern could represent a diagnostic biomarker of MMF in patients with chronic fatigue syndrome and cognitive dysfunction.

  20. Short-Term Practice Effects and Brain Hypometabolism: Preliminary Data from an FDG PET Study

    PubMed Central

    Duff, Kevin; Horn, Kevin P.; Foster, Norman L.; Hoffman, John M.

    2015-01-01

    Practice effects are improvements in cognitive test scores due to repeated exposure to the same tests. Typically viewed as error, short-term practice effects have been shown to provide valuable clinical information about diagnosis, prognosis, and treatment outcomes in older patients with mild cognitive impairments. This study examined short-term practice effects across one week and brain hypometabolism on fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in 25 older adults (15 intact, 10 Mild Cognitive Impairment). Averaged cerebral brain metabolism on FDG PET was correlated with multiple cognitive scores at baseline in those with Mild Cognitive Impairment, and short-term practice effects accounted for additional variance in these same subjects. The relationship between brain metabolism and cognition (either at baseline or practice effects) was minimal in the intact individuals. Although needing replication in larger samples, short-term practice effects on tests of executive functioning and memory may provide valuable information about biomarkers of Alzheimer’s disease. PMID:25908614

  1. F-18-fluorodeoxyglucose positron emission tomography-guided sampling of mediastinal lymph nodes in the diagnosis of cardiac sarcoidosis.

    PubMed

    Simonen, Piia; Lehtonen, Jukka; Kandolin, Riina; Schildt, Jukka; Marjasuo, Suvi; Miettinen, Heikki; Airaksinen, Juhani; Vihinen, Tapani; Tuohinen, Suvi; Haataja, Petri; Kupari, Markku

    2015-11-15

    Histologic proof of granulomatous inflammation is prerequisite for the diagnosis of cardiac sarcoidosis (CS). Because of the limited sensitivity of endomyocardial biopsy (EMB), confirmation of sarcoidosis often has to be acquired from extracardiac biopsies. We set out to review our experience of F-18-fluorodeoxyglucose positron emission tomography (F-18-FDG PET) in guiding extracardiac tissue biopsies in suspected CS. We included in this work 68 consecutive patients with proved CS who had undergone cardiac F-18-FDG PET with (n = 57) or without whole-body imaging as part of initial diagnostic evaluation. Their hospital charts, imaging studies, and diagnostic biopsies were reviewed in retrospect. Whole-body PET images showed extracardiac foci of abnormally high F-18-FDG uptake in 39 of 57 patients, of whom 38 had involvement of mediastinal lymph nodes (MLN). Parallel F-18-FDG uptake was found in other lymph nodes (n = 10), lungs (n = 9), liver (n = 3), spleen (n = 2), and thyroid gland (n = 1). Adding the mediastinal findings at cardiac PET without whole-body imaging, abnormal F-18-FDG uptake in MLN was found in totally 43 of the 68 patients with CS (63%). Histology of systemic sarcoidosis was known at presentation of cardiac symptoms in 8 patients. Of the 60 patients with missing histology, 24 patients underwent mediastinoscopy for sampling of PET-positive MLN, most often (n = 20) after nondiagnostic EMB; microscopy revealed diagnostic noncaseating granulomatous inflammation in 24 of the 24 cases (sensitivity 100%). In the remaining 36 patients, sarcoidosis histology was confirmed by EMB (n = 30), by biopsy of lungs (n = 2) or peripheral lymph nodes (n = 2), or at autopsy (n = 1) or post-transplantation (n = 1). In conclusion, MLN accumulate F-18-FDG at PET in most patients with CS and provide a highly productive source for diagnostic biopsies either primarily or subsequent to nondiagnostic EMB.

  2. Added value of using a cocktail of F-18 sodium fluoride and F-18 fluorodeoxyglucose in positron emission tomography/computed tomography for detecting bony metastasis: a case report.

    PubMed

    Chan, Hung-Pin; Hu, Chin; Yu, Chang-Ching; Huang, Tsung-Chi; Peng, Nan-Jing

    2015-04-01

    Current nuclear imaging of the skeletal system is achieved using technetium-99m (Tc-99m) methylene diphosphonate (MDP), F-18 sodium fluoride (NaF), or F-18 fluorodeoxyglucose (FDG). However, comparisons of these are rare in the literature. We present a case of a 51-year-old female with suspicious lung cancer due to main symptoms of dyspnea, nonproductive cough, and pleural pain. Tc-99m MDP whole-body bone scan (WBBS) showed multiple bony metastases. Five days later, positron emission tomography/computed tomography (PET/CT) images using both F-18 NaF and a cocktail of F-18 NaF and F-18 FDG were obtained on the same day 2 hours apart. The former showed more foci and precisely showed bony lesions compared to those obtained using Tc-99m MDP WBBS. However, the latter demonstrated more extensive radiotracer uptake, especially in osteolytic lesions, and additional soft tissue lesions in the left axillary and surpraclavicular nodes as well as the left pleura. Surgical biopsy was performed in left axillary nodes, and the metastatic carcinoma was found to be of breast origin. This case demonstrated that a cocktail of F-18 NaF and F-18 FDG could be useful in PET/CT for not only detecting more skeletal lesions but also guiding biopsies accurately to the affected tissue.

  3. [F-18]-fluorodeoxyglucose positron emission tomography for targeting radiation dose escalation for patients with glioblastoma multiforme: Clinical outcomes and patterns of failure

    SciTech Connect

    Douglas, James G. . E-mail: drjay@u.washington.edu; Stelzer, Keith J.; Mankoff, David A.; Tralins, Kevin S.; Krohn, Kenneth A.; Muzi, Mark; Silbergeld, Daniel L.; Rostomily, Robert C.; Scharnhorst, Jeffrey B.S.; Spence, Alexander M.

    2006-03-01

    Purpose: [F-18]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging for brain tumors has been shown to identify areas of active disease. Radiation dose escalation in the treatment of glioblastoma multiforme may lead to improved disease control. Based on these premises, we initiated a prospective study of FDG-PET for the treatment planning of radiation dose escalation for the treatment of glioblastoma multiforme. Methods and Materials: Forty patients were enrolled. Patients were treated with standard conformal fractionated radiotherapy with volumes defined by MRI imaging. When patients reached a dose of 45-50.4 Gy, they underwent FDG-PET imaging for boost target delineation, for an additional 20 Gy (2 Gy per fraction) to a total dose of 79.4 Gy (n = 30). Results: The estimated 1-year and 2-year overall survival (OS) for the entire group was 70% and 17%, respectively, with a median overall survival of 70 weeks. The estimated 1-year and 2-year progression-free survival (PFS) was 18% and 3%, respectively, with a median of 24 weeks. No significant improvements in OS or PFS were observed for the study group in comparison to institutional historical controls. Conclusions: Radiation dose escalation to 79.4 Gy based on FDG-PET imaging demonstrated no improvement in OS or PFS. This study establishes the feasibility of integrating PET metabolic imaging into radiotherapy treatment planning.

  4. Utility of F-18 fluorodeoxyglucose posıtron emıssıon tomography/computed ın carcınoma of unknown primary.

    PubMed

    Elboga, Umut; Kervancioğlu, Selim; Sahin, Ertan; Basibuyuk, Mustafa; Celen, Y Zeki; Aktolun, Cumali

    2014-01-01

    Carcinoma of unknown primary (CUP) is a heterogeneous group of tumors with various clinical features causing diagnostic and therapeutic challenges. The aim of this study was to evaluate the ability of F-18 FDG PET/CT for localizing the primary tumor, disclosing additional metastases, and changing the treatment in patients with CUP. One hundred and twelve metastatic patients (female = 40, male = 72, median age = 60.5 years) in whom conventional diagnostic work-up failed to disclose the primary tumor were included in the study. F-18 FDG PET/CT imaging was performed in a standard protocol (patient supine, arms on patient's side, vertex to thigh, 369.3 MBq (296-444 MBq) F-18 FDG, a 60-minute uptake period, 6-7 bed position). Histopathology was taken as the only reference standard. F-18 FDG PET/CT correctly detected primary tumor in 37 of 112 (33.03%) patients. The most common site of primary tumor detected by F-18 FDG PET/CT was lung (n = 18), which was followed by nasopharynx (n = 7), pancreas (n = 5), tonsil (n = 2), breast (n = 2), thyroid (n = 1), uterus (n = 1) and colon/rectum (n = 1). F-18 FDG PET/CT imaging disclosed additional previously undetected metastases in 32 (28.5%) and changed the treatment in 33 (29.4%) of 112 patients. There were false positive F-18 FDG PET/CT results in 21 (18.5%) patients. F-18 FDG PET/CT is able to disclose the primary tumor, disclose new metatases and change the treatment in about one third of patients with CUP.

  5. Potential of F-18 PET/CT in the Detection of Leptomeningeal Metastasis.

    PubMed

    Short, Ryan G; Bal, Susan; German, John P; Poelstra, Raymond J; Kardan, Arash

    2014-12-01

    Leptomeningeal metastasis (LM) is a rare but increasingly common condition in which malignant cells migrate to the meninges. The gold standard for diagnosing LM is detection of cancer cells in the cerebrospinal fluid (CSF). Contrast enhanced-magnetic resonance imaging (CE-MRI) is also used to diagnose LM. We describe a case of LM in which CE-MRI of the neuroaxis was initially negative for meningeal enhancement but F-18 fluorodeoxyglucose positron-emission tomography/computed tomography (F-18 FDG PET/CT) revealed hypermetabolism within the lumbar spinal canal. Positive F-18 FDG PET findings have rarely been reported in LM and, to our knowledge, have never been reported in the context of initially negative CE-MRI scanning of the neuroaxis. F-18 FDG PET/CT may represent an alternative modality for diagnosing LM in patients who are unable to undergo CE-MRI and/or LP or in patients for whom initial CE-MRI and/or LP are negative for LM.

  6. 18F-FDG PET/CT Brain Imaging on a Patient With Paraneoplastic Opsoclonus-Myoclonus Syndrome Arising out of a Mature Cystic Teratoma.

    PubMed

    Na, Chang Ju; Jeong, Young Jin; Lim, Seok Tae; Sohn, Myung-Hee; Jeong, Hwan-Jeong

    2016-02-01

    Opsoclonus-myoclonus syndrome (OMS) is an involuntary multidirectional eye movement accompanied by myoclonic jerks and a subtype of paraneoplastic neurological syndromes. Clinical features of OMS include opsoclonus with myoclonic jerks and cerebellar ataxia. Although there have been a few studies on brain FDG PET in paraneoplastic neurological syndrome associated with some kinds of malignancies such as lung and gastric cancer, brain FDG PET of patients with OMS caused by a mature cystic teratoma has not been reported. Here, we described a case of brain FDG PET/CT studies performed in a woman with OMS provoked from a mature cystic teratoma.

  7. F-18 Fluoride Positron Emission Tomography-Computed Tomography for Detecting Atherosclerotic Plaques.

    PubMed

    Kang, Won Jun

    2015-01-01

    A large number of major cardiovascular events occur in patients due to minimal or some lumen narrowing of the coronary artery. Recent biological studies have shown that the biological composition or vulnerability of the plaque is more critical for plaque rupture compared to the degree of stenosis. To overcome the limitations of anatomical images, molecular imaging techniques have been suggested as promising imaging tools in various fields. F-18 fluorodeoxyglucose (FDG), which is widely used in the field of oncology, is an example of molecular probes used in atherosclerotic plaque evaluation. FDG is a marker of plaque macrophage glucose utilization and inflammation, which is a prominent characteristic of vulnerable plaque. Recently, F-18 fluoride has been used to visualize vulnerable plaque in clinical studies. F-18 fluoride accumulates in regions of active microcalcification, which is normally observed during the early stages of plaque formation. More studies are warranted on the accumulation of F-18 fluoride and plaque formation/vulnerability; however, due to high specific accumulation, low background activity, and easy accessibility, F-18 fluoride is emerging as a promising non-invasive imaging probe to detect vulnerable plaque.

  8. Parkinson's disease-related perfusion and glucose metabolic brain patterns identified with PCASL-MRI and FDG-PET imaging

    PubMed Central

    Teune, Laura K.; Renken, Remco J.; de Jong, Bauke M.; Willemsen, Antoon T.; van Osch, Matthias J.; Roerdink, Jos B.T.M.; Dierckx, Rudi A.; Leenders, Klaus L.

    2014-01-01

    Introduction Under normal conditions, the spatial distribution of resting cerebral blood flow and cerebral metabolic rate of glucose are closely related. A relatively new magnetic resonance (MR) technique, pseudo-continuous arterial spin labeling (PCASL), can be used to measure regional brain perfusion. We identified a Parkinson's disease (PD)-related perfusion and metabolic covariance pattern in the same patients using PCASL and FDG-PET imaging and assessed (dis)similarities in the disease-related pattern between perfusion and metabolism in PD patients. Methods Nineteen PD patients and seventeen healthy controls underwent [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging. Of 14 PD patients and all healthy controls PCASL-MRI could be obtained. Data were analyzed using scaled subprofile model/principal component analysis (SSM/PCA). Results Unique Parkinson's disease-related perfusion and metabolic covariance patterns were identified using PCASL and FDG-PET in the same patients. The PD-related metabolic covariance brain pattern is in high accordance with previously reports. Also our disease-related perfusion pattern is comparable to the earlier described perfusion pattern. The most marked difference between our perfusion and metabolic patterns is the larger perfusion decrease in cortical regions including the insula. Conclusion We identified PD-related perfusion and metabolic brain patterns using PCASL and FDG-PET in the same patients which were comparable with results of existing research. In this respect, PCASL appears to be a promising addition in the early diagnosis of individual parkinsonian patients. PMID:25068113

  9. Pancreatic tuberculosis: Evaluation of therapeutic response using F-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography.

    PubMed

    Santhosh, Sampath; Bhattacharya, Anish; Rana, Surinder Singh; Bhasin, Deepak Kumar; Srinivasan, Radhika; Mittal, Bhagwant Rai

    2014-10-01

    F-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG PET/CT) is a functional imaging technique that monitors glucose metabolism in tissues. Pulmonary tuberculosis (TB) has been reported to show intense uptake of FDG, with a decrease in metabolism of the tuberculous lesions after successful anti-tubercular treatment (ATT). The authors present a patient with pancreatic TB and demonstrate the usefulness of FDG PET/CT in monitoring the response to ATT.

  10. Evaluation of MLACF based calculated attenuation brain PET imaging for FDG patient studies

    NASA Astrophysics Data System (ADS)

    Bal, Harshali; Panin, Vladimir Y.; Platsch, Guenther; Defrise, Michel; Hayden, Charles; Hutton, Chloe; Serrano, Benjamin; Paulmier, Benoit; Casey, Michael E.

    2017-04-01

    Calculating attenuation correction for brain PET imaging rather than using CT presents opportunities for low radiation dose applications such as pediatric imaging and serial scans to monitor disease progression. Our goal is to evaluate the iterative time-of-flight based maximum-likelihood activity and attenuation correction factors estimation (MLACF) method for clinical FDG brain PET imaging. FDG PET/CT brain studies were performed in 57 patients using the Biograph mCT (Siemens) four-ring scanner. The time-of-flight PET sinograms were acquired using the standard clinical protocol consisting of a CT scan followed by 10 min of single-bed PET acquisition. Images were reconstructed using CT-based attenuation correction (CTAC) and used as a gold standard for comparison. Two methods were compared with respect to CTAC: a calculated brain attenuation correction (CBAC) and MLACF based PET reconstruction. Plane-by-plane scaling was performed for MLACF images in order to fix the variable axial scaling observed. The noise structure of the MLACF images was different compared to those obtained using CTAC and the reconstruction required a higher number of iterations to obtain comparable image quality. To analyze the pooled data, each dataset was registered to a standard template and standard regions of interest were extracted. An SUVr analysis of the brain regions of interest showed that CBAC and MLACF were each well correlated with CTAC SUVrs. A plane-by-plane error analysis indicated that there were local differences for both CBAC and MLACF images with respect to CTAC. Mean relative error in the standard regions of interest was less than 5% for both methods and the mean absolute relative errors for both methods were similar (3.4%  ±  3.1% for CBAC and 3.5%  ±  3.1% for MLACF). However, the MLACF method recovered activity adjoining the frontal sinus regions more accurately than CBAC method. The use of plane-by-plane scaling of MLACF images was found to be a

  11. Preparation and biodistribution of F-18 labeled FQNPe

    SciTech Connect

    Luo, H.; Beets, K.; McPherson, D.W.; Knapp, F.F. Jr.

    1996-05-01

    1-Azabicyclo[2.2.2]oct-3-yl {alpha}-(1-fluoropentan-5-yl)-{alpha}-hydroxy-{alpha}-phenylacetate (FQNPe) is an attractive candidate for the in vivo imaging of muscarinic receptors (mAChR) by PET. Initial studies with this new agent demonstrated a high binding affinity and ability to bind to regions of the brain containing mAChR. Fluorine-18 (F-18) labeling of racemic 1 was performed using X = tosyl, triflate, or mesylate group and a decay corrected radiolabeling yields of 2.6, 33, 75%, respectively, were obtained. F-18-3 in 11 % yield (decay corrected to beginning of synthesis). Initial biodistribution studies in rats (n=5) showed F-18-3 had high cerebral uptake of 0.72 ({plus_minus}0.26) and 0.83 ({plus_minus} 0.12) injected dose/gram at 15 and 30 minutes, respectively. The F-18 labeling and biodistribution study of the (-)-quinuclidinyl (-)-acetate and (-)-quinuclidinyl (+)-acetate isomers of FQNPe are currently being pursued.

  12. Investigation of partial volume correction methods for brain FDG PET studies

    SciTech Connect

    Yang, J.; Huang, S.C.; Mega, M.; Toga, A.W.; Small, G.W.; Phelps, M.E.; Lin, K.P.

    1996-12-01

    The use of positron emission tomography (PET) in quantitative fluorodeoxyglucose (FDG) studies of aging and dementia has been limited by partial volume effects. A general method for correction of partial volume effects (PVE) in PET involves the following common procedures; segmentation of MRI brain images into gray matter (GM), white matter (WM), cerebral spinal fluid (CSF), and muscle (MS) components; MRI PET registration; and generation of simulated PET images. Afterward, two different approaches can be taken. The first approach derives first a pixel-by-pixel correction map as the ratio of the measured image to the simulated image [with realistic full-width at half-maximum (FWHM)]. The correction map was applied to the MRI segmentation image. Regions of interest (ROI`s) can then be applied to give results free of partial volume effects. The second approach uses the ROI values of the simulated ``pure`` image (with negligible FWHM) and those of the simulated and the measured PET images to correct for the PVE effect. By varying the ratio of radiotracer concentrations for different tissue components, the in-plane FWHM`s of a three-dimensional point spread function, and the ROI size, the authors evaluated the performance of these two approaches in terms of their accuracy and sensitivity to different simulation configurations. The results showed that both approaches are more robust than the approach developed by Muller-Gartner et al., and the second approach is more accurate and more robust than the first. In conclusion, the authors recommend that the second approach should be used on FDG PET images to correct for partial volume effects and to determine whether an apparent change in GM radiotracer concentration is truly due to metabolic changes.

  13. Factors affecting bilateral temporal lobe hypometabolism on 18F-FDG PET brain scan in unilateral medial temporal lobe epilepsy.

    PubMed

    Tepmongkol, Supatporn; Srikijvilaikul, Teeradej; Vasavid, Pataramon

    2013-11-01

    Bilateral temporal lobe hypometabolism (BTH) on (18)F-FDG PET brain scan is frequently seen in unilateral medial temporal lobe epilepsy (mTLE). This study aimed to identify the factors that influence BTH in patients with mTLE in order to minimize the significant factor(s) prior to performing a FDG-PET brain scan. Forty patients with unilateral mTLE who underwent (18)F-FDG PET scan for presurgical epilepsy workup were included. Bilateral temporal lobe hypometabolism of the anterior and medial parts of the temporal lobe was identified by a semiquantitative visual scale. Lateralization of TLE was identified by either intracranial EEG (22/40 cases) and/or improvement of seizure 2 years after temporal lobectomy (37/40 cases). The factors analyzed included basic demographic characteristics (age, sex, occupation, years of education, and handedness), history related to seizure (age at epilepsy onset and epilepsy duration, history of febrile seizure and head injury, frequency of seizure with impaired cognition in the last 3 months, presence of secondarily generalized tonic-clonic seizure, automatism side, presence of postictal confusion, and side of MRI temporal abnormality), information during video-EEG monitoring (clinical lateralization, interictal scalp EEG lateralization (interictal epileptiform discharge), and ictal scalp EEG lateralization), and information during the FDG-PET study (duration from the last seizure (≤2 days or >2 days), last seizure type, and the presence of slow waves or sharp waves during the FDG uptake period). Significant factors related to BTH were analyzed using multivariate analysis. Only the ≤2-day duration from the last seizure to the PET scan shows a significant effect (p=0.021) on BTH finding with 15 times greater incidence compared to a duration >2 days. Bilateral temporal lobe hypometabolism, which causes conflict in lateralizing the epileptogenic zone in temporal lobe epilepsy, can be avoided by performing PET scan more than 2 days

  14. Classification of Parkinsonian Syndromes from FDG-PET Brain Data Using Decision Trees with SSM/PCA Features

    PubMed Central

    Mudali, D.; Teune, L. K.; Renken, R. J.; Leenders, K. L.; Roerdink, J. B. T. M.

    2015-01-01

    Medical imaging techniques like fluorodeoxyglucose positron emission tomography (FDG-PET) have been used to aid in the differential diagnosis of neurodegenerative brain diseases. In this study, the objective is to classify FDG-PET brain scans of subjects with Parkinsonian syndromes (Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy) compared to healthy controls. The scaled subprofile model/principal component analysis (SSM/PCA) method was applied to FDG-PET brain image data to obtain covariance patterns and corresponding subject scores. The latter were used as features for supervised classification by the C4.5 decision tree method. Leave-one-out cross validation was applied to determine classifier performance. We carried out a comparison with other types of classifiers. The big advantage of decision tree classification is that the results are easy to understand by humans. A visual representation of decision trees strongly supports the interpretation process, which is very important in the context of medical diagnosis. Further improvements are suggested based on enlarging the number of the training data, enhancing the decision tree method by bagging, and adding additional features based on (f)MRI data. PMID:25918550

  15. Comparison of brain MRI and 18F-FDG PET in the differential diagnosis of multiple system atrophy from Parkinson's disease.

    PubMed

    Kwon, Kyum-Yil; Choi, Choong G; Kim, Jae S; Lee, Myoung C; Chung, Sun J

    2007-12-01

    To investigate the diagnostic value of brain magnetic resonance image (MRI) and (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) in the differentiation of multiple system atrophy (MSA) from Parkinson's disease (PD). Thirty-five patients with MSA (23 MSA-P and 12 MSA-C) and 17 patients with PD were included in this study. Overall correct diagnosis rates between clinical and imaging diagnosis among MSA-P, MSA-C, and PD patients were 80% for visual MRI analysis, 88.5% for visual (18)F-FDG PET analysis, and 84.3% for SPM-supported analysis of (18)F-FDG PET. The sensitivity of brain MRI, and visual and SPM analysis of (18)F-FDG PET in differentiating MSA from PD was 72.7%, 90.9%, and 95.5%, respectively, the specificity was 100% for each imaging analysis, the positive predictive value was 100% for each imaging analysis, and the negative predictive value was 60%, 81.8%, and 90%, respectively. Our results suggest that brain MRI and (18)F-FDG PET are diagnostically useful in differentiating MSA (MSA-P and MSA-C) from PD, and indicate that (18)F-FDG PET has a tendency toward higher sensitivity compared to brain MRI, but a larger longitudinal study including pathological data will be required to confirm our findings.

  16. Intracranial Leptomeningeal Carcinomatosis in Three Cases from Breast Cancer Demonstrated on F-18 Fluorodeoxyglucose Positron Emission Tomography/Computerized Tomography.

    PubMed

    Ortapamuk, Hulya; Demir, Mustafa Kemal

    2017-01-01

    Leptomeningeal carcinomatosis (LC) is an uncommon late manifestation of non-central nervous system (CNS) solid tumors. With prolonged survival in solid tumors, an increased frequency of metastases is noted in these tumors too. The detection of tumor cells in the cerebrospinal fluid remains the gold standard. Noninvasively, magnetic resonance imaging is frequently used for the diagnosis of LC. Although its low sensitivity of F-18 fluorodeoxyglucose positron emission tomography/computerized tomography (F-18 FDG PET/CT) on demonstrating CNS lesions, it could be useful in identifying the possibility of LC of breast carcinoma by giving high attention to the meninges. We discuss here three cases all of them having intracranial LC; where (18)F-FDG PET/CT study helped us in the diagnosis of LC. To our knowledge, this is the second report about intracranial LC from breast cancer demonstrating on (18)F-FDG PET/CT.

  17. Intracranial Leptomeningeal Carcinomatosis in Three Cases from Breast Cancer Demonstrated on F-18 Fluorodeoxyglucose Positron Emission Tomography/Computerized Tomography

    PubMed Central

    Ortapamuk, Hulya; Demir, Mustafa Kemal

    2017-01-01

    Leptomeningeal carcinomatosis (LC) is an uncommon late manifestation of non-central nervous system (CNS) solid tumors. With prolonged survival in solid tumors, an increased frequency of metastases is noted in these tumors too. The detection of tumor cells in the cerebrospinal fluid remains the gold standard. Noninvasively, magnetic resonance imaging is frequently used for the diagnosis of LC. Although its low sensitivity of F-18 fluorodeoxyglucose positron emission tomography/computerized tomography (F-18 FDG PET/CT) on demonstrating CNS lesions, it could be useful in identifying the possibility of LC of breast carcinoma by giving high attention to the meninges. We discuss here three cases all of them having intracranial LC; where 18F-FDG PET/CT study helped us in the diagnosis of LC. To our knowledge, this is the second report about intracranial LC from breast cancer demonstrating on 18F-FDG PET/CT. PMID:28242978

  18. Advantages and disadvantages of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of unknown primary.

    PubMed

    Yu, Xiaozhou; Li, Xiaofeng; Song, Xiuyu; Dai, Dong; Zhu, Lei; Zhu, Yanjia; Wang, Jian; Zhao, Huiqin; Xu, Wengui

    2016-11-01

    Carcinoma of unknown primary is a type of malignant disease where the primary carcinoma cannot be identified by conventional examination, which presents challenges in diagnosis and therapy. This study aims to evaluate the detailed clinical value and indications of using fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in a large sample. A total of 449 patients who were selected under strict standards were retrospectively included in this study. F-18 FDG PET/CT accurately detected the primary carcinoma in 115 of 449 patients whose primaries could not be detected by conventional examination (25.6%), with additional 27 false-positive patients. The most common primary site was the lung (34.8%). In addition, except for in metastatic melanoma (1/19, 5.3%) and axillary metastasis patients (2/49, 4.1%), F-18 FDG PET/CT had a comparative performance in detecting primary carcinoma in other pathological types and anatomical locations. The scan is able to guide treatment strategy modifications to some extent (130/449, 29.0%). We strongly recommend the use of F-18 FDG PET/CT in the early phase of examination. It is also recommended as a supplementary radiological method, and certain patients may benefit from its application in cases where regular examination is inconclusive. However, in metastatic melanoma or axillary metastasis patients where the primary site cannot be identified by routine examination, regular application of F-18 FDG PET/CT for the sole purpose of detecting the primary carcinoma should not be encouraged.

  19. Advantages and disadvantages of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of unknown primary

    PubMed Central

    Yu, Xiaozhou; Li, Xiaofeng; Song, Xiuyu; Dai, Dong; Zhu, Lei; Zhu, Yanjia; Wang, Jian; Zhao, Huiqin; Xu, Wengui

    2016-01-01

    Carcinoma of unknown primary is a type of malignant disease where the primary carcinoma cannot be identified by conventional examination, which presents challenges in diagnosis and therapy. This study aims to evaluate the detailed clinical value and indications of using fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in a large sample. A total of 449 patients who were selected under strict standards were retrospectively included in this study. F-18 FDG PET/CT accurately detected the primary carcinoma in 115 of 449 patients whose primaries could not be detected by conventional examination (25.6%), with additional 27 false-positive patients. The most common primary site was the lung (34.8%). In addition, except for in metastatic melanoma (1/19, 5.3%) and axillary metastasis patients (2/49, 4.1%), F-18 FDG PET/CT had a comparative performance in detecting primary carcinoma in other pathological types and anatomical locations. The scan is able to guide treatment strategy modifications to some extent (130/449, 29.0%). We strongly recommend the use of F-18 FDG PET/CT in the early phase of examination. It is also recommended as a supplementary radiological method, and certain patients may benefit from its application in cases where regular examination is inconclusive. However, in metastatic melanoma or axillary metastasis patients where the primary site cannot be identified by routine examination, regular application of F-18 FDG PET/CT for the sole purpose of detecting the primary carcinoma should not be encouraged. PMID:27895731

  20. Direct mapping of 19F in 19FDG-6P in brain tissue at subcellular resolution using soft X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Poitry-Yamate, C.; Gianoncelli, A.; Kourousias, G.; Kaulich, B.; Lepore, M.; Gruetter, R.; Kiskinova, M.

    2013-10-01

    Low energy x-ray fluorescence (LEXRF) detection was optimized for imaging cerebral glucose metabolism by mapping the fluorine LEXRF signal of 19F in 19FDG, trapped as intracellular 19F-deoxyglucose-6-phosphate (19FDG-6P) at 1μm spatial resolution from 3μm thick brain slices. 19FDG metabolism was evaluated in brain structures closely resembling the general cerebral cytoarchitecture following formalin fixation of brain slices and their inclusion in an epon matrix. 2-dimensional distribution maps of 19FDG-6P were placed in a cytoarchitectural and morphological context by simultaneous LEXRF mapping of N and O, and scanning transmission x-ray (STXM) imaging. A disproportionately high uptake and metabolism of glucose was found in neuropil relative to intracellular domains of the cell body of hypothalamic neurons, showing directly that neurons, like glial cells, also metabolize glucose. As 19F-deoxyglucose-6P is structurally identical to 18F-deoxyglucose-6P, LEXRF of subcellular 19F provides a link to in vivo 18FDG PET, forming a novel basis for understanding the physiological mechanisms underlying the 18FDG PET image, and the contribution of neurons and glia to the PET signal.

  1. Development and use of a kinetic FDG-PET dataset simulated from the MNI standard brain

    NASA Astrophysics Data System (ADS)

    Schottlander, David; Guimond, Alexandre; Pan, Xiao-Bo; Brady, Michael; Declerck, Jérôme; Collins, Louis; Evans, Alan C.; Reilhac, Anthonin

    2006-03-01

    Simulated data is an important tool for evaluation of reconstruction and image processing algorithms in the frequent absence of ground truth, in-vivo data from living subjects. This is especially true in the case of dynamic PET studies, in which counting statistics of the volume can vary widely over the time-course of the acquisition. Realistic simulated data-sets which model anatomy and physiology, and make explicit the spatial and temporal image acquisition characteristics, facilitate experimentation with a wide range of the conditions anticipated in practice, and which can severely challenge algorithm performance and reliability. As a first example, we have developed a realistic dynamic FDG-PET data-set using the PET-SORTEO Monte Carlo simulation code and the MNI digital brain phantom. The phantom is a three-dimensional data-set that defines the spatial distribution of different tissues. Time activity curves were calculated using an impulse response function specified by generally accepted rate constants, convolved with an input function obtained by blood sampling, and assigned to grey and white matter tissue regions. We created a dynamic PET study using PET-SORTEO configured to simulate an ECAT Exact HR+. The resulting sinograms were reconstructed with all corrections, using variations of FBP and OSEM. Having constructed the dynamic PET data-sets, we used them to evaluate the performance of intensity-based registration as part of a tool for quantifying hyper/hypo perfusion with particular application to analysis of brain dementia scans, and a study of the stability of kinetic parameter estimation.

  2. F-18 HARV research pilot Jim Smolka

    NASA Technical Reports Server (NTRS)

    1994-01-01

    James W. 'Smoke' Smolka, a research pilot at NASA's Dryden Flight Research Center, Edwards, California, since 1985, was co-project pilot on the F-18 High Alpha Research Vehicle (HARV) aircraft. Before joining NASA, Smolka was an F-16 experimental test pilot with General Dynamics Corporation for two years at Edwards. He was also a project pilot with the Advanced Fighter Technology Integration (AFTI) F-16 Joint Test Force located at Dryden. In addition to his work with the F-18 program, Smolka also flies as a pilot on the NASA B-52 launch aircraft, and as a co-project pilot on the F-16XL Supersonic Laminar Flow aircraft. He also participated in F-15 HIDEC flight and engine control system programs, and the AFTI F-111 Mission Adaptive Wing, and F-104 Aeronautical Research Aircraft programs. Smolka has accumulated 5000 hours of flight time since he became a pilot in 1973. NASA used an F-18 Hornet fighter aircraft as its High Alpha Research Vehicle (HARV). The aircraft is on loan from the U.S. Navy. The high angle of attack technology program is a joint effort of NASA's Dryden, Ames, Langley, and Lewis Research Centers. Its flight operations were based at Dryden.

  3. Identification of ischemic and hibernating myocardium: feasibility of post-exercise F-18 deoxyglucose positron emission tomography

    SciTech Connect

    Marwick, T.H.; MacIntyre, W.J.; Salcedo, E.E.; Go, R.T.; Saha, G.; Beachler, A. )

    1991-02-01

    The identification of ischemic and hibernating myocardium facilitates the selection of patients most likely to benefit from revascularization. This study examined the feasibility of metabolic imaging, using post-exercise F-18 deoxyglucose positron emission tomography (FDG-PET) for the diagnosis of both ischemia and hibernation in 27 patients with known coronary anatomy. Normal post-exercise FDG uptake was defined in each patient by reference to normal resting perfusion and normal coronary supply. Abnormal elevation of FDG (ischemia or hibernation) was compared in 13 myocardial segments in each patient, with the results of dipyridamole stress perfusion imaging performed by rubidium-82 positron emission tomography (Rb-PET). Myocardial ischemia was diagnosed by either FDG-PET or Rb-PET in 34 segments subtended by significant local coronary stenoses. Increased FDG uptake was present in 32/34 (94%) and a reversible perfusion defect was identified by Rb-PET in 22/34 (65%, p less than .01). In 3 patients, ischemia was identified by metabolic imaging alone. In 16 patients with previous myocardial infarction, perfusion defects were present at rest in 89 regions, 30 of which (34%) demonstrated increased FDG uptake, consistent with the presence of hibernation. Increased post-exercise FDG uptake appears to be a sensitive indicator of ischemia and myocardial hibernation. Increased post-exercise FDG uptake, appears to be a sensitive indicator of ischemia and myocardial hibernation. This test may be useful in selecting post-infarction patients for revascularization.

  4. Predicting conversion from MCI to AD with FDG-PET brain images at different prodromal stages.

    PubMed

    Cabral, Carlos; Morgado, Pedro M; Campos Costa, Durval; Silveira, Margarida

    2015-03-01

    Early diagnosis of Alzheimer disease (AD), while still at the stage known as mild cognitive impairment (MCI), is important for the development of new treatments. However, brain degeneration in MCI evolves with time and differs from patient to patient, making early diagnosis a very challenging task. Despite these difficulties, many machine learning techniques have already been used for the diagnosis of MCI and for predicting MCI to AD conversion, but the MCI group used in previous works is usually very heterogeneous containing subjects at different stages. The goal of this paper is to investigate how the disease stage impacts on the ability of machine learning methodologies to predict conversion. After identifying the converters and estimating the time of conversion (TC) (using neuropsychological test scores), we devised 5 subgroups of MCI converters (MCI-C) based on their temporal distance to the conversion instant (0, 6, 12, 18 and 24 months before conversion). Next, we used the FDG-PET images of these subgroups and trained classifiers to distinguish between the MCI-C at different stages and stable non-converters (MCI-NC). Our results show that MCI to AD conversion can be predicted as early as 24 months prior to conversion and that the discriminative power of the machine learning methods decreases with the increasing temporal distance to the TC, as expected. These findings were consistent for all the tested classifiers. Our results also show that this decrease arises from a reduction in the information contained in the regions used for classification and by a decrease in the stability of the automatic selection procedure.

  5. F-18 SRA taxi at dawn

    NASA Technical Reports Server (NTRS)

    1993-01-01

    One of NASA's F/A-18 Hornets is seen here sitting on the ramp at the Dryden Flight Research Center, Edwards, California, at dawn August 6, 1993. F-18 aircraft, on loan to NASA by the U.S. Navy, are currently being flown at Dryden as support aircraft and as research testbeds. As support aircraft, they are used primarily for safety chase, pilot proficiency and aerial photography. As research aircraft, they are involved in thrust vectoring and high angle of attack research, as well as numerous smaller scale experiments.

  6. FDG-PET in the Evaluation of Brain Metabolic Changes Induced by Cognitive Stimulation in aMCI Subjects.

    PubMed

    Ciarmiello, Andrea; Gaeta, Maria Chiara; Benso, Francesco; Del Sette, Massimo

    2015-01-01

    Cognitive training has reported to improve cognitive performance in Mild Cognitive Impairment (MCI) as well as in older healthy subjects. 18F-FDG-PET is widely used in the diagnoses of dementia for its ability to identify early metabolic changes. This study was aimed to assess the effect of cognitive stimulation on brain metabolic network and clinical cognitive performance. Thirty aMCI subjects were enrolled in the study and allocated in two groups matched for cognitive profile, sex and schooling and then randomly assigned to the training arm or to the placebo arm. All subjects underwent neuropsychological assessment and PET imaging before and after intervention. We found significant association between brain metabolism and cognitive stimulation in treated aMCI subjects. Brain metabolic changes included Brodmann areas reported to be involved in working memory and attentive processes as well as executive functions. Our study shows that metabolic changes occur earlier than possible clinical changes related to the intervention. 18F-FDG-PET could provide a useful biomarker of response to identify a population of aMCI suitable to respond to treatment, according to most recent data on default network mode and its adaptivity to external stimuli.

  7. F-18 cockpit and instrument panel

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's Dryden Flight Research Center's F/A-18 chase and support aircraft retains the basic fighter plane cockpit controls with some exceptions. The pilot's center control stick is relatively typical of a modern fighter aircraft. This F-18 has no weapons delivery capability. The primary cockpit displays include a left- and right-side cathode-ray tube display, referred to as the DDIs, and the heads-up display (HUD). The DDIs and HUD are generally used to display primary flight condition information such as airspeed, altitude, altitude rate, attitude, heading, etc. Other flight conditions displayed include angle of attack (AOA), Mach number, and load factor. The HUD also provides primary flight condition information to the pilot without having to refer to the DDIs. Select flight controls information also can be presented on the HUD. The twenty pushbuttons located on the periphery of each DDI are used to select a variety of displays for pilot interrogation of F-18 systems. These displays are pilot selectable and menu driven.

  8. Synthesis of 6-(F-18)L-fluoro-dopa using F-18 labelled acetyl hypofluorite

    SciTech Connect

    Adam, M.J.; Abeysekera, B.; Ruth, T.J.; Grierson, J.R.; Pate, B.D.

    1985-05-01

    The synthesis of (F-18)6-fluoro-dopa via acetyl hypofluorite has recently been reported. The authors have modified this procedure by adding an acetate protecting group on the dopa ring and have treated this new starting material with either solution or gas phase F-18 acetyl hypofluorite. Using this starting material the yield has been significantly increased over the published method. The authors routinely prepare 4-5 mCi of pure (F-18)6-fluoro-dopa (3-4% radiochemical yield, at EOS) in an overall synthesis time of 2 hours. Both 2 and 6 fluoro-dopa are produced in nearly equivalent amounts by this method as determined by /sup 19/F nmr. These are easily separated by HPLC after deblocking with HI. The final isolated product is >99% in the L-isomer form and fluorinated in >97% in the 6 position.

  9. F18-fluorodeoxyglucose-positron emission tomography and computed tomography is not accurate in preoperative staging of gastric cancer

    PubMed Central

    Ha, Tae Kyung; Choi, Yun Young; Song, Soon Young

    2011-01-01

    Purpose To investigate the clinical benefits of F18-fluorodeoxyglucose-positron emission tomography and computed tomography (18F-FDG-PET/CT) over multi-detector row CT (MDCT) in preoperative staging of gastric cancer. Methods FDG-PET/CT and MDCT were performed on 78 patients with gastric cancer pathologically diagnosed by endoscopy. The accuracy of radiologic staging retrospectively was compared to pathologic result after curative resection. Results Primary tumors were detected in 51 (65.4%) patients with 18F-FDG-PET/CT, and 47 (60.3%) patients with MDCT. Regarding detection of lymph node metastasis, the sensitivity of FDG-PET/CT was 51.5% with an accuracy of 71.8%, whereas those of MDCT were 69.7% and 69.2%, respectively. The sensitivity of 18F-FDG-PET/CT for a primary tumor with signet ring cell carcinoma was lower than that of 18F-FDG-PET/CT for a primary tumor with non-signet ring cell carcinoma (35.3% vs. 73.8%, P < 0.01). Conclusion Due to its low sensitivity, 18F-FDG-PET/CT alone shows no definite clinical benefit for prediction of lymph node metastasis in preoperative staging of gastric cancer. PMID:22066108

  10. MRI-based elastic-mapping method for inter-subject comparison of brain FDG-PET images

    SciTech Connect

    Yang, J.; Huang, S.C.; Lin, K.P.; Small, G.; Phelps, M.E.

    1996-12-31

    Inter-subject anatomic differences prohibits direct image-wise statistical evaluation of brain FDG-PET images of Alzheimer`s disease (AD) patients. In this study, we propose a MRI-based elastic-mapping method which enables image-wise evaluation. The method involves intra-subject MR-PET registration, 3-D elastic mapping of two set of MR images, and elastically transforming the co-registered PET images. The MR-PET registration used simulated PET images, which were based on segmentation of MR images. In the 3-D elastic mapping stage, first a global linear scaling was applied to compensate for brain size difference, then a deformation field was obtained by minimizing the regional sum of squared difference between the two sets of MR images. Two groups (AD patient and normal control), each with three subjects, were included in the current study. After processing, images from all subjects have similar shapes. Averaging the images across all subjects (either within the individual group or for both groups) give images indistinguishable from original single subject FDG images (i.e. without much spatial resolution loss), except with lower image noise level. The method is expected to allow statistical image-wise analysis to be performed across different subjects.

  11. Intelligent [F-18] fluoride target system

    NASA Astrophysics Data System (ADS)

    Hichwa, R. D.; Aykac, M.; Bilgen, D.; Watkins, G. L.

    1999-06-01

    An automated target filling system has been developed for [F-18]F- production from [O-18]water. The system consists of a pair of standard syringe dispensing pumps, valve manifolds, pressure and flow sensors, RS-232 serial I/O modules, high pressure silver targets and X-windows software. Operations are controlled through a graphical interface and can be manipulated individually, in groups for specific functions, or as complex processes either manually or automatically. Major functional operations include: 1) system test, 2) target fill, 3) target empty, and 4) target clean up. Fault conditions if present are identified and flagged. Alternate (duplicate) pathways are automatically used if a nonfatal failure mode is detected. Results from the testing procedures are logged to a file for documented adherence to SOPs and trend assessment of performance.

  12. F-18 SRA in flight from below

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's Dryden Flight Research Center, Edwards, California, is using this early-model F-18 Hornet as a flying research platform to evaluate a number of emerging technologies in aircraft control and information systems. The Systems Research Aircraft, a pre-production two-seat version of the twin-engine tactical fighter aircraft, has been extensively modified for its research role. Among projects flown on the plane are experiments to evaluate fiber optics for flight-critical control systems, advanced air data acquisition systems, and electrically-powered flight control actuators which do not require connection to the aircraft central hydraulic system. The new technologies could lead to lighter and more efficient aircraft designs with higher performance and greater safety.

  13. F-18 HARV research pilot Dana Purifoy

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Dana D. Purifoy is an aerospace research pilot at NASA's Dryden Flight Research Center, Edwards, California. He joined NASA in August 1994. Purifoy is a former Air Force test pilot who served as a project pilot in the joint NASA/Air Force X-29 Forward Swept Wing research program conducted at Dryden from 1984 to 1991. His most recent assignment in the Air Force was flying U-2 aircraft as a test pilot at Air Force Plant 42, Palmdale, CA. In addition to flying the X-29 at Dryden as an Air Force pilot, Purifoy also served as project pilot and joint test force director with the AFTI F-16 (Advanced Fighter Technology Integration/F-16) program, also located at Dryden. Before his assignments as project pilot on the X-29 and AFTI/F-16 aircraft, Purifoy was chief of the Academics Systems Branch at the Air Force Test Pilot School at Edwards. Prior to becoming a test pilot, he flew F-111 and F-16 aircraft in Great Britain and Germany. He has accumulated 3800 hours of flying time in his career. The final flight for the F-18 High Alpha Research Vehicle (HARV) took place at NASA Dryden on May 29, 1996. The highly modified F-18 airplane flew 383 flights over a nine year period and demonstrated concepts that greatly increase fighter maneuverability. Among concepts proven in the aircraft is the use of paddles to direct jet engine exhaust in cases of extreme altitudes where conventional control surfaces lose effectiveness. Another concept, developed by NASA Langley Research Center, is a deployable wing-like surface installed on the nose of the aircraft for increased right and left (yaw) control on nose-high flight angles.

  14. Relationship between Tl-201, Tc-99m (Sn) pyrophosphate and F-18 2-deoxyglucose uptake in ischemically injured dog myocardium

    SciTech Connect

    Sochor, H.; Schwaiger, M.; Schelbert, H.R.; Huang, S.C.; Ellison, D.; Hansen, H.; Selin, C.; Parodi, O.; Phelps, M.E.

    1987-11-01

    We have previously demonstrated that enhanced glucose utilization in reperfused myocardium as assessed by F-18 2-deoxyglucose (FDG) and positron tomography predicts functional recovery. In this study, we compared segmental uptake of F-18 FDG with that of Tl-201 and Tc-99m (Sn) pyrophosphate (Tc-99m PPi) as conventional markers of tissue viability in seven dogs after a 3-hour intracoronary balloon occlusion and 20 hours of reperfusion. Myocardial blood flow was determined with microspheres. Regional retention fractions were calculated from tracer tissue concentrations, the arterial input function, and blood flow. Ischemic injury was assessed by triphenyltetrazolium chloride (TTC) staining and histologic analysis. At 24 hours, blood flow was 22% lower in reperfused than in control myocardium (p less than 0.05). Uptake of Tl-201 was related linearly to blood flow (r = 0.92), while glucose utilization and Tc-99m PPi were 2.9 (p less than 0.01) and 4.7 (p less than 0.05) times higher in reperfused than in control myocardium. Retention fractions of Tc-99m PPi increased with the degree of ischemic injury, while F-18 FDG uptake was highest in segments with mild cell injury. Thus, in ischemically injured myocardium, Tl-201 primarily reflects blood flow. F-18 FDG as a marker of glucose utilization identifies ischemically injured but viable tissue. The admixture of necrotic cells can be determined with Tc-99m PPi. Our results indicate that a dual tracer approach might best characterize the presence and extent of reversibly and of irreversibly injured tissue in a given myocardial region.

  15. Brain metastases detectability of routine whole body (18)F-FDG PET and low dose CT scanning in 2502 asymptomatic patients with solid extracranial tumors.

    PubMed

    Bochev, Pavel; Klisarova, Aneliya; Kaprelyan, Ara; Chaushev, Borislav; Dancheva, Zhivka

    2012-01-01

    As fluorine-18-fluorodesoxyglucose positron emission tomography/computed tomography ( (18)F-FDG PET/CT) is gaining wider availability, more and more patients with malignancies undergo whole body PET/CT, mostly to assess tumor spread in the rest of the body, but not in the brain. Brain is a common site of metastatic spread in patients with solid extracranial tumors. Gold standard in the diagnosis of brain metastases remains magnetic resonance imaging (MRI). However MRI is not routinely indicated and is not available for all cancer patients. Fluorine-18-FDG PET is considered as having poor sensitivity in detecting brain metastases, but this may not be true for PET/CT. The aim of our study was to assess the value of (18)F-FDG PET/CT in the detection of brain metastases found by whole body scan including the brain, in patients with solid extracranial neoplasms. A total of 2502 patients with solid extracranial neoplasms were studied. All patients underwent a routine whole body (18)F-FDG PET/CT scan with the whole brain included in the scanned field. Patients with known or suspected brain metastases were preliminary excluded from the study. Hypermetabolic and ring-like brain lesions on the PET scan were considered as metastases. Lesions with CT characteristics of brain metastases were regarded as such irrespective of their metabolic pattern. Lesions in doubt were verified by MRI during first testing or on follow-up or by operation. Our results showed that brain lesions, indicative of and verified to be metastases were detected in 25 out of the 2502 patients (1%), with lung cancer being the most common primary. Twenty three out of these 25 patients had no neurological symptoms by the time of the scan. The detection rate of brain metastases was relatively low, but information was obtained with a minimum increase of radiation burden. In conclusion, whole body (18)F-FDG PET/CT detected brain metastases in 1% of the patients if brain was included in the scanned field. Brain

  16. Exploratory Evaluation of MR Permeability with 18F-FDG PET Mapping in Pediatric Brain Tumors: A Report from the Pediatric Brain Tumor Consortium

    PubMed Central

    Zukotynski, Katherine A.; Fahey, Frederic H.; Vajapeyam, Sridhar; Ng, Sarah S.; Kocak, Mehmet; Gururangan, Sridharan; Kun, Larry E.; Poussaint, Tina Y.

    2014-01-01

    The purpose of this study was to develop a method of registering 18F-FDG PET with MR permeability images for investigating the correlation of 18F-FDG uptake, permeability, and cerebral blood volume (CBV) in children with pediatric brain tumors and their relationship with outcome. Methods Twenty-four children with brain tumors in a phase II study of bevacizumab and irinotecan underwent brain MR and 18F-FDG PET within 2 wk. Tumor types included supratentorial high-grade astrocytoma (n = 7), low-grade glioma (n = 9), brain stem glioma (n = 4), medulloblastoma (n = 2), and ependymoma (n = 2). There were 33 cases (pretreatment only [n = 12], posttreatment only [n = 3], and both pretreatment [n = 9] and posttreatment [n = 9]). 18F-FDG PET images were registered to MR images from the last time point of the T1 perfusion time series using mutual information. Three-dimensional regions of interest (ROIs) drawn on permeability images were automatically transferred to registered PET images. The quality of ROI registration was graded (1, excellent; 2, very good; 3, good; 4, fair; and 5, poor) by 3 independent experts. Spearman rank correlations were used to assess correlation of maximum tumor permeability (Kpsmax), maximum CBV (CBVmax), and maximum 18F-FDG uptake normalized to white matter (T/Wmax). Cox proportional hazards models were used to investigate associations of these parameters with progression-free survival (PFS). Results The quality of ROI registration between PET and MR was good to excellent in 31 of 33 cases. There was no correlation of baseline Kpsmax with CBVmax (Spearman rank correlation =0.018 [P =0.94]) or T/Wmax (Spearman rank correlation = 0.07 [P = 0.76]). Baseline CBVmax was correlated with T/Wmax (Spearman rank correlation = 0.47 [P = 0.036]). Baseline Kpsmax, CBVmax, and T/Wmax were not significantly associated with PFS (P = 0.42, hazard ratio [HR] = 0.97, 95% confidence interval [CI] = 0.90–1.045, and number of events [nevents] = 15 for Kpsmax; P = 0

  17. 76 FR 37129 - Determination That SODIUM FLUORIDE F 18 (Sodium Fluoride F-18) Injection, 10 to 200 Millicuries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ... HUMAN SERVICES Food and Drug Administration Determination That SODIUM FLUORIDE F 18 (Sodium Fluoride F... Drug Administration (FDA) has determined that SODIUM FLUORIDE F 18 (sodium fluoride F-18) injection, 10... effectiveness. This determination will allow FDA to approve abbreviated new drug applications (ANDAs) for...

  18. F-18 SRA during flight from below

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Aeronautics and Space Administration's Systems Research Aircraft (SRA), a highly modified F-18 jet fighter, shows its colors during a recent research flight. The former Navy aircraft is being flown by NASA's Dryden Flight Research Center at Edwards Air Force Base, California, to evaluate a number of experimental aerospace technologies in a multi-year, joint NASA/DOD/industry program. Among the more than 20 experiments being flight-tested were several involving fiber optic sensor systems. Experiments developed by McDonnell-Douglas and Lockheed-Martin centered on installation and maintenace techniques for various types of fiber-optic hardware proposed for use in military and commercial aircraft, while a Parker-Hannifin experiment focused in alternative fiber-optic designs for postion measurement sensors as well as operational experience in handling optical sensor systems. Other experiments being flown on this testbed aircraft include electronically-controlled control surface actuators, flush air data collection systems, 'smart' skin antennae and laser-based systems. Incorporation of one or more of these technologies in future aircraft and spacecraft could result in signifigant savings in weight, maintenance and overall cost.

  19. F-18 SRA in flight over lakebed

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The National Aeronautics and Space Administration's Systems Research Aircraft (SRA), a highly modified F-18 jet fighter, on an early research flight over Rogers Dry Lake. The former Navy aircraft is being flown by NASA's Dryden Flight Research Center at Edwards Air Force Base, California, to evaluate a number of experimental aerospace technologies in a multi-year, joint NASA/DOD/industry program. Among the more than 20 experiments being flight-tested were several involving fiber optic sensor systems. Experiments developed by McDonnell-Douglas and Lockheed-Martin centered on installation and maintenace techniques for various types of fiber-optic hardware proposed for use in military and commercial aircraft, while a Parker-Hannifin experiment focused in alternative fiber-optic designs for postion measurement sensors as well as operational experience in handling optical sensor systems. Other experiments being flown on this testbed aircraft include electronically-controlled control surface actuators, flush air data collection systems, 'smart' skin antennae and laser-based systems. Incorporation of one or more of these technologies in future aircraft and spacecraft could result in signifigant savings in weight, maintenance and overall cost.

  20. Effect of α-Methyl versus α-Hydrogen Substitution on Brain Availability and Tumor Imaging Properties of Heptanoic [F-18]Fluoroalkyl Amino Acids for Positron Emission Tomography (PET).

    PubMed

    Bouhlel, Ahlem; Alyami, Wadha; Li, Aixiao; Yuan, Liya; Rich, Keith; McConathy, Jonathan

    2016-04-14

    Two [(18)F]fluoroalkyl substituted amino acids differing only by the presence or absence of a methyl group on the α-carbon, (S)-2-amino-7-[(18)F]fluoro-2-methylheptanoic acid ((S)-[(18)F]FAMHep, (S)-[(18)F]14) and (S)-2-amino-7-[(18)F]fluoroheptanoic acid ((S)-[(18)F]FAHep, (S)-[(18)F]15), were developed for brain tumor imaging and compared to the well-established system L amino acid tracer, O-(2-[(18)F]fluoroethyl)-l-tyrosine ([(18)F]FET), in the delayed brain tumor (DBT) mouse model of high-grade glioma. Cell uptake, biodistribution, and PET/CT imaging studies showed differences in amino acid transport of these tracer by DBT cells. Recognition of (S)-[(18)F]15 but not (S)-[(18)F]14 by system L amino acid transporters led to approximately 8-10-fold higher uptake of the α-hydrogen substituted analogue (S)-[(18)F]15 in normal brain. (S)-[(18)F]15 had imaging properties similar to those of (S)-[(18)F]FET in the DBT tumor model while (S)-[(18)F]14 afforded higher tumor to brain ratios due to much lower uptake by normal brain. These results have important implications for the future development of α-alkyl and α,α-dialkyl substituted amino acids for brain tumor imaging.

  1. Rare case of primary inferior vena cava leiomyosarcoma on F-18 fluorodeoxyglucose positron emission tomography-computed tomography scan: Differentiation from nontumor thrombus in a background of procoagulant state.

    PubMed

    Singh, Natasha; Shivdasani, Divya; Karangutkar, Sanket

    2014-10-01

    We report a rare case of leiomyosarcoma of the inferior vena cava (IVC) in which F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography-computed tomography (PET-CT) scan provided vital evidence, which led to its diagnosis, in a background of procoagulant state of the patient, where previous ultrasound-Doppler and echocardiography studies were nonspecific and revealed bilateral lower limb deep vein thrombosis with thrombus in IVC. The whole body F-18 FDG PET-CT scan was done in view of no significant improvement in clinical status of the patient over few months in spite of appropriate medical management. FDG PET-CT scan revealed high grade uptake in a large mass lesion occupying the right atrium, extending superiorly into terminal superior vena cava, inferiorly into dilated IVC and probably into hepatic veins. CT guided biopsy of this F-18 FDG avid mass was consistent with the diagnosis of leiomyosarcoma, which however was not amenable to surgery at this stage. F-18 FDG PET-CT accurately differentiated tumor mass from bland thrombus and further had a significant impact on the management, since aggressive surgery combined with adjuvant therapy offers the best outcome for patients with leiomyosarcoma of the IVC.

  2. A follow-up ¹⁸F-FDG brain PET study in a case of Hashimoto's encephalopathy causing drug-resistant status epilepticus treated with plasmapheresis.

    PubMed

    Pari, Elisa; Rinaldi, Fabrizio; Premi, Enrico; Codella, Maria; Rao, Renata; Paghera, Barbara; Panarotto, Maria Beatrice; De Maria, Giovanni; Padovani, Alessandro

    2014-04-01

    Hashimoto's encephalopathy (HE) is a rare neuropsychiatric syndrome associated with antithyroid antibodies. It may have an acute onset (episodes of cerebral ischemia, seizure, and psychosis) or it may present as an indolent form (depression, cognitive decline, myoclonus, tremors, and fluctuations in level of consciousness). We here describe a case of encephalopathy presenting as non-convulsive status epilepticus associated with Hashimoto's thyroiditis (HT), unresponsive to corticosteroid therapy, with improvement after plasma exchange treatment. A previously healthy 19-year-old woman, presented generalized tonic-clonic seizures. About a month later, she manifested a speech disorder characterized by difficulties in the production and comprehension of language. Within a few days she also developed confusion and difficulties in recognizing familiar places, with gradual worsening over time. EEG revealed a non-convulsive status epilepticus (NCSE). CSF examination showed slightly elevated cell count and four oligoclonal bands. MRI was unremarkable, and (18)F-FDG brain PET showed widespread hypometabolism, mostly in posterior regions bilaterally. Laboratory and ultrasound findings showed signs of HT. Treatment with steroid was introduced without any improvement. After five sessions of plasma exchange there was a decrease of antithyroid antibodies, as well as EEG and clinical improvement. Three months after discharge (18)F-FDG brain PET showed a complete normalization of the picture, and the patient was asymptomatic. This report emphasizes the successful treatment of HE with plasma exchange in a patient who presented with NCSE. Based on the actual evidence, the term "Encephalopathy associated with Hashimoto's thyroiditis" may be the most proper. Furthermore, to our knowledge, this is the first case of an adult patient studied twice with an (18)F-FDG brain PET: prior to treatment with plasma exchange, and at 3 months follow-up when the patient was clinically completely

  3. Differential diagnosis of adrenal mass using imaging modality: special emphasis on f-18 fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography.

    PubMed

    Lee, Hong Je; Lee, Jaetae

    2014-03-01

    Adrenal incidentalomas are adrenal masses serendipitously detected during an imaging study performed for reasons unrelated to suspicion of adrenal disease. The incidence of adrenal incidentalomas has increased because of the widespread use of various imaging modalities. In oncology patients with adrenal incidentalomas, the characterization of the adrenal masses is challenging because nearly 50% of incidental adrenal masses are metastatic lesions that need special medical attention. Although unenhanced computed tomography (CT) densitometry, chemical shift magnetic resonance imaging (MRI), delayed contrast-enhanced CT and CT histogram analysis have been used as sensitive and specific modalities for differentiating benign from malignant adrenal masses, F-18 fluoro-2-deoxy-D-glucose positron emission tomography (F-18 FDG PET)/CT is a highly accurate imaging modality compared to CT or MRI, especially when these two imaging modalities are combined. In addition, a semiquantitative analysis using standardized uptake value ratio further improves the diagnostic accuracy of F-18 FDG PET/CT in differentiating benign from malignant adrenal masses. Thus, F-18 FDG PET/CT is very helpful for determining the best therapeutic management, especially for assessing the need for surgery.

  4. Defining risk groups of patients with cancer of unknown primary site and cervical nodal metastases by F-18 fluorodeoxyglucose positron emission tomography and computed tomography imaging.

    PubMed

    Su, Yung-Yueh; Chen, Shih-Shin; Hsieh, Chia-Hsun; Liao, Chun-Ta; Lin, Chien-Yu; Kang, Chung-Jan; Yen, Tzu-Chen

    2016-08-01

    We sought to investigate the clinical utility of F-18 fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT) in Taiwanese patients with cancer of unknown primary site (CUP) and cervical nodal metastases. We also aimed to study the impact of F-18 FDG PET/CT on clinical treatment priority in this patient group. Between September 2006 and May 2014, patients with CUP and cervical nodal metastases who underwent F-18 FDG PET/CT imaging study were retrospectively identified. The clinicopathological risk factors and PET parameters were analyzed in relation to 2-year overall survival (OS) rates using univariate and multivariate analyses. Two-year OS curves were plotted with the Kaplan-Meier method. Of the eligible patients (n = 54), 12 (22.2%) had distant metastases (DM) at presentation. A total of 13 (24.1%) and 15 (27.8%) primary tumors were identified by FDG PET/CT imaging and an additional triple biopsy, respectively. The results of multivariate analysis identified smoking [p = 0.033, 95% confidence interval (CI) = 1.197-40.342], a maximum standardized uptake value (SUVmax) of cervical nodes ≥ 14.2 (p = 0.035, 95% CI = 1.134-28.029), and DM at presentation (p = 0.031, 95% CI = 1.257-114.854) as independent predictors of 2-year OS. Specifically, patients who carried ≥ 2 risk factors showed poorer outcomes (70.3% vs. 11.8%, p < 0.001). Fifteen study patients (27.8%) had their treatment modified by FDG PET/CT findings. We conclude that FDG PET/CT is clinically useful in CUP patients not only for tumor staging, but also for modifying treatment regimens.

  5. Reversal of brain metabolic abnormalities following treatment of AIDS dementia complex with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine): a PET-FDG study

    SciTech Connect

    Brunetti, A.; Berg, G.; Di Chiro, G.; Cohen, R.M.; Yarchoan, R.; Pizzo, P.A.; Broder, S.; Eddy, J.; Fulham, M.J.; Finn, R.D.

    1989-05-01

    Brain glucose metabolism was evaluated in four patients with acquired immunodeficiency syndrome (AIDS) dementia complex using (/sup 18/F)fluorodeoxyglucose (FDG) and positron emission tomography (PET) scans at the beginning of therapy with 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine), and later in the course of therapy. In two patients, baseline, large focal cortical abnormalities of glucose utilization were reversed during the course of therapy. In the other two patients, the initial PET study did not reveal pronounced focal alterations, while the post-treatment scans showed markedly increased cortical glucose metabolism. The improved cortical glucose utilization was accompanied in all patients by immunologic and neurologic improvement. PET-FDG studies can detect cortical metabolic abnormalities associated with AIDS dementia complex, and may be used to monitor the metabolic improvement in response to AZT treatment.

  6. Skeletal muscle metastases as the initial manifestation of an unknown primary lung cancer detected on F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Agrawal, Kanhaiyalal; Bhattacharya, Anish; Singh, Navneet; Harisankar, Chidambaram Natarajan Balasubramanian; Mittal, Bhagwant Rai

    2013-01-01

    Skeletal muscle metastasis as the initial presentation of the unknown primary lung cancer is unusual. A 65-year-old male patient presented with pain and swelling of the right forearm. Fine needle aspiration of the swelling revealed metastatic squamous cell carcinoma. The patient underwent whole body F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) to identify the site of the primary malignancy. The authors present PET/CT images showing FDG-avid metastases to the skeletal muscles along with a previously unknown primary tumor in the right lung, in a patient presenting with initial muscular symptoms without any pulmonary manifestations.

  7. F18 Life Support: APECS and EDOX Cockpit Integration

    NASA Technical Reports Server (NTRS)

    Herrick, Paul

    1998-01-01

    Two systems are currently being integrated into the F18 Hornet support aircraft at NASA Dryden Flight Research Center (DFRC). The first system is the Aircrew Personal Environmental Control System (APECS). The system is designed to increase aircrew performance by combating heat stress in the cockpit. The second system is the Extended Duration Oxygen System (EDOX). This system will provide additional redundancy and oxygen system duration to the F18 without extensive modification to the current system.

  8. Analysis of predictability of F-18 fluorodeoxyglucose-PET/CT in the recurrence of papillary thyroid carcinoma.

    PubMed

    Kim, Suk Kyeong; So, Young; Chung, Hyun Woo; Yoo, Young Bum; Park, Kyung Sik; Hwang, Tae Sook; Kim, Bokyung; Lee, Won Woo

    2016-10-01

    Whether preoperative F-18 fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) can predict recurrence of papillary thyroid carcinoma (PTC) remains unclear. Herein, we evaluated the potential of primary tumor FDG avidity for the prediction of tumor recurrence in PTC patients. A total of 412 PTC patients (72 males, 340 females; age: 47.2 ± 12.2 years; range: 17-84 years) who underwent FDG-PET/CT prior to total thyroidectomy (n = 350), subtotal thyroidectomy (n = 2), or lobectomy (n = 60) from 2007 to 2011 were analyzed. The predictive ability for recurrence was investigated among various clinicopathological factors, BRAF(V)(600E) mutation, and preoperative FDG avidity of the primary tumor using Kaplan-Meier (univariate) and Cox proportional hazards regression (multivariate) analyses. Of the 412 patients, 19 (4.6%) experienced recurrence, which was confirmed either by pathology (n = 17) or high serum thyroglobulin level (n = 2), during a mean follow-up period of 43.9 ± 16.6 months. Of the 412 patients, 237 (57.5%) had FDG-avid tumors (maximum standardized uptake value, 7.1 ± 7.0; range: 1.6-50.5). Kaplan-Meier analysis revealed that tumor size (P = 0.0054), FDG avidity of the tumor (P = 0.0049), extrathyroidal extension (P = 0.0212), and lymph node (LN) stage (P < 0.0001) were significant predictors for recurrence. However, only LN stage remained a significant predictor in the multivariate analysis (P < 0.0001). Patients with FDG-avid tumors had higher LN stage (P < 0.0001), larger tumor size (P < 0.0001), and more frequent extrathyroidal extension (P < 0.0001). In conclusion, FDG avidity of the primary tumor in preoperative FDG-PET/CT could not predict the recurrence of PTC. LN stage was the only identified predictor of PTC recurrence.

  9. Glucose Metabolic Changes in the Brain and Muscles of Patients with Nonspecific Neck Pain Treated by Spinal Manipulation Therapy: A [18F]FDG PET Study

    PubMed Central

    Inami, Akie; Ogura, Takeshi; Watanuki, Shoichi; Masud, Md. Mehedi; Shibuya, Katsuhiko; Miyake, Masayasu; Matsuda, Rin; Hiraoka, Kotaro; Itoh, Masatoshi; Fuhr, Arlan W.; Yanai, Kazuhiko

    2017-01-01

    Objective. The aim of this study was to investigate changes in brain and muscle glucose metabolism that are not yet known, using positron emission tomography with [18F]fluorodeoxyglucose ([18F]FDG PET). Methods. Twenty-one male volunteers were recruited for the present study. [18F]FDG PET scanning was performed twice on each subject: once after the spinal manipulation therapy (SMT) intervention (treatment condition) and once after resting (control condition). We performed the SMT intervention using an adjustment device. Glucose metabolism of the brain and skeletal muscles was measured and compared between the two conditions. In addition, we measured salivary amylase level as an index of autonomic nervous system (ANS) activity, as well as muscle tension and subjective pain intensity in each subject. Results. Changes in brain activity after SMT included activation of the dorsal anterior cingulate cortex, cerebellar vermis, and somatosensory association cortex and deactivation of the prefrontal cortex and temporal sites. Glucose uptake in skeletal muscles showed a trend toward decreased metabolism after SMT, although the difference was not significant. Other measurements indicated relaxation of cervical muscle tension, decrease in salivary amylase level (suppression of sympathetic nerve activity), and pain relief after SMT. Conclusion. Brain processing after SMT may lead to physiological relaxation via a decrease in sympathetic nerve activity. PMID:28167971

  10. Brain metabolic changes in Hodgkin disease patients following diagnosis and during the disease course: An 18F-FDG PET/CT study

    PubMed Central

    CHIARAVALLOTI, AGOSTINO; PAGANI, MARCO; CANTONETTI, MARIA; DI PIETRO, BARBARA; TAVOLOZZA, MARIO; TRAVASCIO, LAURA; DI BIAGIO, DANIELE; DANIELI, ROBERTA; SCHILLACI, ORAZIO

    2015-01-01

    The aim of the present study was to investigate brain glucose metabolism in patients with Hodgkin disease (HD) after diagnosis and during chemotherapy treatment. Following the administration of first-line doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) chemotherapy, 74 HD patients underwent 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography brain scans, both baseline (PET0) and interim (PET2) at the Department of Biomedicine and Prevention, University of Rome Tor Vergata (Rome, Italy). Fifty-seven patients were further evaluated 15±6 days after four additional cycles (PET6). Furthermore, a control group (CG) of 40 chemotherapy-naïve subjects was enrolled. Differences in brain 18F-FDG uptake between the CG, PET0, PET2 and PET6 scans were analyzed using statistical parametric mapping. Compared with the PET0 and CG scans, the PET2 scan demonstrated a higher metabolic activity in Brodmann area (BA) 39, and a metabolic reduction in BA 11 bilaterally and in left BA 32. All of these changes disappeared at PET6. The results of the present study indicate that ABVD chemotherapy has a limited impact on brain metabolism. PMID:25621038

  11. Insufficiency of bone scintigraphy in vertebral lesions of langerhans cell histiocytosis compared to f-18 fluorodeoxyglucose positron emission tomography/computed tomography and diagnostic computed tomography.

    PubMed

    Koç, Zehra Pınar; Şimşek, Selçuk; Akarsu, Saadet; Balcı, Tansel Ansal; Onur, Mehmet Ruhi; Kepenek, Ferat

    2015-02-05

    Langerhans cell histiocytosis (LCH) is a benign disorder related to the histiocytes which can infiltrate bone tissue. The most effective method for demonstrating severity of this disease is PET/CT and bone scintigraphy might show bone lesions. We present a seventeen year old male patient with disseminated LCH presented with exophtalmos and having multiple vertebral lesions which were identified by F-18 FDG PET/CT scan and diagnostic CT but not in the bone scintigraphy.

  12. Reduced grey matter metabolism due to white matter edema allows optimal assessment of brain tumors on 18F-FDG-PET.

    PubMed

    Pourdehnad, Michael; Basu, Sandip; Duarte, Paulo; Okpaku, Aubrey S; Saboury, Babak; Hustinx, Roland; Alavi, Abass

    2011-01-01

    The main aim of this research was to demonstrate that the cortical and subcortical grey matter hypometabolism as revealed by fluorine-18 fluorodesoxyglucose-positron emission tomography ((18)F-FDG-PET) imaging in brain tumors is related to associated edema as demonstrated by magnetic resonance imaging (MRI). This in turn enhances the ability to assess disease activity in the tumor and the degree of loss of cerebral function in the adjacent and distant structures. We evaluated brain T1 and T2 weighted MRI and (18)F-FDG-PET scans of 29 patients (19 adult, 10 pediatric) with history of brain tumor. Tumor histology types included 21 gliomas, 1 melanoma, 1 primitive neuroectodermal tumor, 3 medulloblastomas and 3 ependymomas. The majority of scans were performed within the same week (94% <1 month. The extent of hypo and hypermetabolism was assessed on the (18)F-FDG-PET scans. A template of 12 regions of interest (ROI) was applied and the laterality indices of the regional counts (signal intensity) were computed. Extent of edema, enhancement, and anatomical change were assessed on the MRI scans. Extent of edema in the same ROI was evaluated by a 6-point semiquantitative scale and laterality indices were generated. Metabolic activity of the grey matter was correlated with the extent of edema using these indices. In all cases where edema was present, significant hypometabolism was observed in the adjacent structures. Overall, there was a strong correlation between the extent of edema and severity of hypometabolism (r=0.92, P=0.01). This was true regardless of the location of edema, whether there was history of radiation treatment (r=0.91, P=0.03), or not (r=0.97, P=0.17). In conclusion, edema independent of underlying variables appeared to contribute significantly to cortical and sub-cortical grey matter hypometabolism observed in patients with brain tumors. This would indicate that brain tumors can be successfully assessed by (18)F-FDG-PET and therefore the efforts for

  13. Mapping the Binding Domain of the F18 Fimbrial Adhesin

    PubMed Central

    Smeds, A.; Pertovaara, M.; Timonen, T.; Pohjanvirta, T.; Pelkonen, S.; Palva, A.

    2003-01-01

    F18 fimbrial Esherichia coli strains are associated with porcine postweaning diarrhea and pig edema disease. Recently, the FedF subunit was identified as the adhesin of the F18 fimbriae. In this study, adhesion domains of FedF were further studied by constructing deletions within the fedF gene and expressing FedF proteins with deletions either together with the other F18 fimbrial subunits or as fusion proteins tagged with maltose binding protein. The region essential for adhesion to porcine intestinal epithelial cells was mapped between amino acid residues 60 and 109 of FedF. To map the binding domain even more closely, all eight charged amino acid residues within this region were independently replaced by alanine. Three of these single point mutants expressing F18 fimbriae exhibited significantly diminished capabilities to adhere to porcine epithelial cells in vitro. In addition, a triple point mutation and a double point mutation completely abolished receptor adhesiveness. The result further confirmed that the region between amino acid residues 60 and 109 is essential for the binding of F18 fimbriae to their receptor. In addition, the adhesion capability of the binding domain was eliminated after treatment with iodoacetamide, suggesting the formation of a disulfide bridge between Cys-63 and Cys-83, whereas Cys-111 and Cys-116 could be deleted without affecting the binding ability of FedF. PMID:12654838

  14. Falsely Negative F-18 FDG PET of Osteosarcoma Arising In Paget Disease.

    PubMed

    Bush, Lisabeth Ann; Toresdahl, Brett; Hoch, Benjamin; Chew, Felix S

    2009-01-01

    We present the case of a large, painful pelvic bone tumor in a 53-year-old woman with severe Paget disease. Her presentation was complicated with bilateral total hip arthroplasty, history of spinal stenosis, and multiple lucent lesions in the spine and pelvis in severely affected pagetoid bone. This case features the rare but dreaded complication of osteosarcomatous transformation in Paget disease. A variety of imaging modalities including PET/CT were utilized in the evaluation of these lesions. The PET/CT findings were counter-intuitive with regard to the intense uptake of the underlying chronic disease process and the near-absence of uptake in the tumors. The histology of the pelvic mass is also intriguing, as it demonstrated a sarcoma with giant cell features. Conservative, non-operative management was chosen, due to the patient's poor medical condition, so we may never know the nature of the spinal lesion in this case, but will discuss the differential diagnosis for a lytic spinal lesion in a patient with severe Paget disease complicated by osteosarcoma with giant cell features.

  15. A quantitative analysis of the F18 flight control system

    NASA Technical Reports Server (NTRS)

    Doyle, Stacy A.; Dugan, Joanne B.; Patterson-Hine, Ann

    1993-01-01

    This paper presents an informal quantitative analysis of the F18 flight control system (FCS). The analysis technique combines a coverage model with a fault tree model. To demonstrate the method's extensive capabilities, we replace the fault tree with a digraph model of the F18 FCS, the only model available to us. The substitution shows that while digraphs have primarily been used for qualitative analysis, they can also be used for quantitative analysis. Based on our assumptions and the particular failure rates assigned to the F18 FCS components, we show that coverage does have a significant effect on the system's reliability and thus it is important to include coverage in the reliability analysis.

  16. Construction and Evaluation of Quantitative Small-Animal PET Probabilistic Atlases for [18F]FDG and [18F]FECT Functional Mapping of the Mouse Brain

    PubMed Central

    Casteels, Cindy; Vunckx, Kathleen; Aelvoet, Sarah-Ann; Baekelandt, Veerle; Bormans, Guy; Van Laere, Koen; Koole, Michel

    2013-01-01

    Automated voxel-based or pre-defined volume-of-interest (VOI) analysis of small-animal PET data in mice is necessary for optimal information usage as the number of available resolution elements is limited. We have mapped metabolic ([18F]FDG) and dopamine transporter ([18F]FECT) small-animal PET data onto a 3D Magnetic Resonance Microscopy (MRM) mouse brain template and aligned them in space to the Paxinos co-ordinate system. In this way, ligand-specific templates for sensitive analysis and accurate anatomical localization were created. Next, using a pre-defined VOI approach, test-retest and intersubject variability of various quantification methods were evaluated. Also, the feasibility of mouse brain statistical parametric mapping (SPM) was explored for [18F]FDG and [18F]FECT imaging of 6-hydroxydopamine-lesioned (6-OHDA) mice. Methods Twenty-three adult C57BL6 mice were scanned with [18F]FDG and [18F]FECT. Registrations and affine spatial normalizations were performed using SPM8. [18F]FDG data were quantified using (1) an image-derived-input function obtained from the liver (cMRglc), using (2) standardized uptake values (SUVglc) corrected for blood glucose levels and by (3) normalizing counts to the whole-brain uptake. Parametric [18F]FECT binding images were constructed by reference to the cerebellum. Registration accuracy was determined using random simulated misalignments and vectorial mismatch determination. Results Registration accuracy was between 0.21–1.11 mm. Regional intersubject variabilities of cMRglc ranged from 15.4% to 19.2%, while test-retest values were between 5.0% and 13.0%. For [18F]FECT uptake in the caudate-putamen, these values were 13.0% and 10.3%, respectively. Regional values of cMRglc positively correlated to SUVglc measured within the 45–60 min time frame (spearman r = 0.71). Next, SPM analysis of 6-OHDA-lesioned mice showed hypometabolism in the bilateral caudate-putamen and cerebellum, and an unilateral striatal decrease in DAT

  17. Evaluation of cancer detection with whole-body positron emission tomography (PET) and 2-[F-18]fluoro-2-deoxy-D-glucose

    NASA Astrophysics Data System (ADS)

    Hoh, Carl K.; Hawkins, Randall A.; Glaspy, John A.; Dahlbom, Magnus; Tse, Nielson Y.; Hoffman, Edward T.; Schiepers, Christiaan; Choi, Yong; Rege, Sheila; Nitzsche, Egbert U.; Maddahi, Jamshid; Phelps, Michael E.

    1993-08-01

    Until recently, positron emission tomography (PET) has been acquired and displayed in a standard transaxial image format. The development of whole body PET has allowed biochemical and physiologic imaging of the entire body, expanding the limited axial field of view of the conventional PET scanner. In this study, the application of whole body PET studies with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG) for tumor imaging was evaluated. Whole body PET studies were positive (presence of focal FDG uptake relative to surrounding tissue activity) in 61 of 70 patients (87%) with biopsy confirmed malignant tumors. PET images failed to reveal focal hypermetabolism in 9 of the 70 patients. Of the 17 patients with benign biopsies lesions, 13 patients had whole body PET studies without focal areas of FDG uptake. Because of the high glycolytic rate of malignant tissue, the whole body PET FDG technique has promise in the detection of a wide variety of both primary and metastatic malignancies. The presence of FDG uptake in benign inflammatory conditions may limit the specificity of the technique. The true positive rates for the characterization of known lesions was 87% in this series, and the PET FDG method is promising both in determining both the nature of a localized lesion, and in defining the systemic extent of malignant disease.

  18. [F-18]-(-,-)-FQNPe - an attractive ligand for evaluation of muscarinic-cholinergic neuron activity by PET

    SciTech Connect

    Luo, H.; McPherson, D.W.; Beets, A.L.; Knapp, F.F. Jr.

    1997-05-01

    The stereoisomers of 1-azabicyclo[2.2.2]oct-3-yl {alpha}-{alpha}-(1-fluoropentan-5-yl)-{alpha}-hydroxy-{alpha}-phenylacetate ({open_quotes}FQNPe{close_quotes}) have been resolved. (-,-)- receptors (K{sub i}, nM; ml, 0.3; m2, 0.1). [F-18]-(-,-)-FQNPe demonstrated high cerebral and myocardial uptake in rats in vivo. We now report significant blocking of [F-18]-(-.-)-FQNPe uptake in receptor-rich tissues in rats in vivo after (R)-QNB pretreatment and the absence of any TLC detectable FQNPe metabolites in tissue extracts. Rats were injected with (R)-QNB (3 mg/kg) 1 h prior to [F-18]-FQNPe injection (370-629 KBq). After 1 h, rats were sacrificed and tissues removed and counted. (R)-QNB significantly decreased FQNPe uptake in heart and all receptor-rich regions but not blood (Table; Mean % ID/g, n=5); C, control; Q, (R)-QNB; Hrt, heart; Cer, cerebellum; Pon, pons; Med, medulla; Cor, cortex; Stri, striatum; Hip, hippocampus; Th, thallamus; SuC, superior colliculi; InC, inferior colliculi. Tissues from untreated rats were Folch-extracted and 71-77% of activity was in organic extracts from brain and heart. TLC of organic extracts indicated a single radioactive component with R{sub f} of FQNPe. These combined results demonstrate that [F-18]-(-,-)-FQNPe does not appear to be metabolized in heart and brain, shows good receptor localization and is thus an attractive ligand for evaluation as a potential imaging agent by PET.

  19. F-18 HARV With Nose Strakes For Forebody Vortex Control

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.

    1996-01-01

    Nose of F-18 High Alpha Research Vehicle (HARV) modified with conformal, mechanically actuated nose strakes for enhanced rolling (ANSER). Forebody vortex control effected by use of actuated strakes and/or other flow-control devices. System provides means to evaluate design tradeoffs.

  20. Two F-18s in Autonomous Formation Flight

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This 32 second video clip shows two F-18s in NASA's Autonomous Formation Flight (AFF) program. The aircraft use smoke contrails to gather data on wingtip vortices. Flight research attempts to utilize the energy in the vortices for more efficient flight.

  1. Synthesis of F-18 labeled resazurin by direct electrophilic fluorination

    PubMed Central

    Kachur, Alexander V.; Arroyo, Alejandro D.; Popov, Anatoliy V.; Saylor, Sarah J.; Delikatny, E. James

    2015-01-01

    We present the synthesis and characterization of F18-labeled fluorinated derivatives of resazurin, a probe for cell viability. The compounds were prepared by direct fluorination of resazurin with diluted [F18]-F2 gas under acidic conditions. The fluorination occurs into the ortho-positions to the hydroxyl group producing various mono-, di-, and trifluorinated derivatives. The properties of the fluorinated resazurins are similar to the parent compound with the addition of fluorine leading to decreased pKa values and a bathochromic shift of the absorption maxima. The fluorinated resazurin derivatives can be used as probes for observation of cell viability in various cells, tissues and organs using a combination of positron emission tomography and direct optical imaging of Cerenkov luminescence. PMID:26504251

  2. F-18 HARV final flight over Edwards AFB

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The final flight for the F-18 High Alpha Research Vehicle (HARV) took place at NASA Dryden Flight Research Center, Edwards, California, on May 29, 1996 and was flown by NASA pilot Ed Schneider. The highly modified F-18 airplane flew 383 flights over a nine year period and demonstrated concepts that greatly increase fighter maneuverability. Among concepts proven in the aircraft is the use of paddles to direct jet engine exhaust in cases of extreme altitudes where conventional control surfaces lose effectiveness. Another concept, developed by NASA Langley Research Center, is a deployable wing-like surface installed on the nose of the aircraft for increased right and left (yaw) control on nose-high flight angles.

  3. F-18 HARV final flight over Dryden FRC

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The final flight for the F-18 High Alpha Research Vehicle (HARV) took place at NASA Dryden Flight Research Center, Edwards, California, on May 29, 1996 and was flown by NASA pilot Ed Schneider. The highly modified F-18 airplane flew 383 flights over a nine year period and demonstrated concepts that greatly increase fighter maneuverability. Among concepts proven in the aircraft is the use of paddles to direct jet engine exhaust in cases of extreme altitudes where conventional control surfaces lose effectiveness. Another concept, developed by NASA Langley Research Center, is a deployable wing-like surface installed on the nose of the aircraft for increased right and left (yaw) control on nose-high flight angles.

  4. F-18 high alpha research vehicle: Lessons learned

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.; Regenie, Victoria A.; Flick, Bradley C.

    1994-01-01

    The F-18 High Alpha Research Vehicle has proven to be a useful research tool with many unique capabilities. Many of these capabilities are to assist in characterizing flight at high angles of attack, while some provide significant research in their own right. Of these, the thrust vectoring system, the unique ability to rapidly reprogram flight controls, the reprogrammable mission computer, and a reprogrammable onboard excitation system have allowed an increased utility and versatility of the research being conducted. Because of this multifaceted approach to research in the high angle of attack regime, the capabilities of the F-18 High Alpha Research Vehicle were designed to cover as many high alpha technology bases as the program would allow. These areas include aerodynamics, controls, handling qualities, and propulsion.

  5. F-18 HARV in flight refueling with KC-135 tanker

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A thrust vectoring system can be seen mounted on the aft end of this NASA F-18 research aircraft at the Dryden Flight Research Center, Edwards, California, during an inflight refueling stop with a KC-135A (Serial #55-3135) tanker. The system was used to enhance its maneuverability and control at high angles of attack (high alpha) when conventional aerodynamic controls - ailerons, rudders, and elevators - are ineffective. The system features three spoon-shaped paddles mounted around the exhaust nozzles of each engine. The system, linked to the aircraft's flight control system, moves the paddles into the exhaust flow to redirect thrust for directional control and increased maneuverability at angles of attack near 70 degrees. First research flights with the system operating began during the spring of 1991. Data from the F-18 High Alpha Research Vehicle (HARV) program produced information to validate computer codes and wind tunnel results and led to design methods providing better performance in future aircraft.

  6. Atomic Mass and Nuclear Binding Energy for F-18 (Fluorine)

    NASA Astrophysics Data System (ADS)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume A `Nuclei with Z = 1 - 54' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope F-18 (Fluorine, atomic number Z = 9, mass number A = 18).

  7. A New F-18 Labeled PET Agent For Imaging Alzheimer's Plaques

    NASA Astrophysics Data System (ADS)

    Kulkarni, Padmakar V.; Vasdev, Neil; Hao, Guiyang; Arora, Veera; Long, Michael; Slavine, Nikolai; Chiguru, Srinivas; Qu, Bao Xi; Sun, Xiankai; Bennett, Michael; Antich, Peter P.; Bonte, Frederick J.

    2011-06-01

    Amyloid plaques and neurofibrillary tangles are hallmarks of Alzheimer's disease (AD). Advances in development of imaging agents have focused on targeting amyloid plaques. Notable success has been the development of C-11 labeled PIB (Pittsburgh Compound) and a number of studies have demonstrated the utility of this agent. However, the short half life of C-11 (t1/2: 20 min), is a limitation, thus has prompted the development of F-18 labeled agents. Most of these agents are derivatives of amyloid binding dyes; Congo red and Thioflavin. Some of these agents are in clinical trials with encouraging results. We have been exploring new class of agents based on 8-hydroxy quinoline, a weak metal chelator, targeting elevated levels of metals in plaques. Iodine-123 labeled clioquinol showed affinity for amyloid plaques however, it had limited brain uptake and was not successful in imaging in intact animals and humans. We have been successful in synthesizing F-18 labeled 8-hydroxy quinoline. Small animal PET/CT imaging studies with this agent showed high (7-10% ID/g), rapid brain uptake and fast washout of the agent from normal mice brains and delayed washout from transgenic Alzheimer's mice. These promising results encouraged us in further evaluation of this class of compounds for imaging AD plaques.

  8. Relationship between baseline brain metabolism measured using [¹⁸F]FDG PET and memory and executive function in prodromal and early Alzheimer's disease.

    PubMed

    Habeck, Christian; Risacher, Shannon; Lee, Grace J; Glymour, M Maria; Mormino, Elizabeth; Mukherjee, Shubhabrata; Kim, Sungeun; Nho, Kwangsik; DeCarli, Charles; Saykin, Andrew J; Crane, Paul K

    2012-12-01

    Differences in brain metabolism as measured by FDG-PET in prodromal and early Alzheimer's disease (AD) have been consistently observed, with a characteristic parietotemporal hypometabolic pattern. However, exploration of brain metabolic correlates of more nuanced measures of cognitive function has been rare, particularly in larger samples. We analyzed the relationship between resting brain metabolism and memory and executive functioning within diagnostic group on a voxel-wise basis in 86 people with AD, 185 people with mild cognitive impairment (MCI), and 86 healthy controls (HC) from the Alzheimer's Disease Neuroimaging Initiative (ADNI). We found positive associations within AD and MCI but not in HC. For MCI and AD, impaired executive functioning was associated with reduced parietotemporal metabolism, suggesting a pattern consistent with known AD-related hypometabolism. These associations suggest that decreased metabolic activity in the parietal and temporal lobes may underlie the executive function deficits in AD and MCI. For memory, hypometabolism in similar regions of the parietal and temporal lobes were significantly associated with reduced performance in the MCI group. However, for the AD group, memory performance was significantly associated with metabolism in frontal and orbitofrontal areas, suggesting the possibility of compensatory metabolic activity in these areas. Overall, the associations between brain metabolism and cognition in this study suggest the importance of parietal and temporal lobar regions in memory and executive function in the early stages of disease and an increased importance of frontal regions for memory with increasing impairment.

  9. Flagella from F18+Escherichia coli play a role in adhesion to pig epithelial cell lines.

    PubMed

    Duan, Qiangde; Zhou, Mingxu; Zhu, Xiaofang; Yang, Yang; Zhu, Jun; Bao, Wenbin; Wu, Shenglong; Ruan, Xiaosai; Zhang, Weiping; Zhu, Guoqiang

    2013-02-01

    F18 fimbriae and toxins produced by F18 fimbriae-carrying Escherichia coli (E. coli) strains are known virulence factors responsible for post-weaning diarrhea (PWD) and edema disease (ED). In this study, we showed that fliC isogenic mutants constructed in two reference wild-type F18 fimbriae (F18+) E. coli were markedly impaired in adherence in vitro cell models (p < 0.05). Flagella purified from F18+E. coli could directly bind to cultured piglet epithelial cells and block adherence of F18+E. coli to cells when pre-incubated. In addition, the F18+E. coli fliC deletion mutants up-regulated the expression of type I fimbriae produced by F18+E. coli strains. These results demonstrated that expression of flagella is essential for the adherence of F18+E. coli in vitro.

  10. Age- and Brain Region-Specific Changes of Glucose Metabolic Disorder, Learning, and Memory Dysfunction in Early Alzheimer’s Disease Assessed in APP/PS1 Transgenic Mice Using 18F-FDG-PET

    PubMed Central

    Li, Xue-Yuan; Men, Wei-Wei; Zhu, Hua; Lei, Jian-Feng; Zuo, Fu-Xing; Wang, Zhan-Jing; Zhu, Zhao-Hui; Bao, Xin-Jie; Wang, Ren-Zhi

    2016-01-01

    Alzheimer’s disease (AD) is a leading cause of dementia worldwide, associated with cognitive deficits and brain glucose metabolic alteration. However, the associations of glucose metabolic changes with cognitive dysfunction are less detailed. Here, we examined the brains of APP/presenilin 1 (PS1) transgenic (Tg) mice aged 2, 3.5, 5 and 8 months using 18F-labed fluorodeoxyglucose (18F-FDG) microPET to assess age- and brain region-specific changes of glucose metabolism. FDG uptake was calculated as a relative standardized uptake value (SUVr). Morris water maze (MWM) was used to evaluate learning and memory dysfunction. We showed a glucose utilization increase in multiple brain regions of Tg mice at 2 and 3.5 months but not at 5 and 8 months. Comparisons of SUVrs within brains showed higher glucose utilization than controls in the entorhinal cortex, hippocampus, and frontal cortex of Tg mice at 2 and 3.5 months but in the thalamus and striatum at 3.5, 5 and 8 months. By comparing SUVrs in the entorhinal cortex and hippocampus, Tg mice were distinguished from controls at 2 and 3.5 months. In MWM, Tg mice aged 2 months shared a similar performance to the controls (prodromal-AD). By contrast, Tg mice failed training tests at 3.5 months but failed all MWM tests at 5 and 8 months, suggestive of partial or complete cognitive deficits (symptomatic-AD). Correlation analyses showed that hippocampal SUVrs were significantly correlated with MWM parameters in the symptomatic-AD stage. These data suggest that glucose metabolic disorder occurs before onset of AD signs in APP/PS1 mice with the entorhinal cortex and hippocampus affected first, and that regional FDG uptake increase can be an early biomarker for AD. Furthermore, hippocampal FDG uptake is a possible indicator for progression of Alzheimer’s cognition after cognitive decline, at least in animals. PMID:27763550

  11. Age- and Brain Region-Specific Changes of Glucose Metabolic Disorder, Learning, and Memory Dysfunction in Early Alzheimer's Disease Assessed in APP/PS1 Transgenic Mice Using (18)F-FDG-PET.

    PubMed

    Li, Xue-Yuan; Men, Wei-Wei; Zhu, Hua; Lei, Jian-Feng; Zuo, Fu-Xing; Wang, Zhan-Jing; Zhu, Zhao-Hui; Bao, Xin-Jie; Wang, Ren-Zhi

    2016-10-18

    Alzheimer's disease (AD) is a leading cause of dementia worldwide, associated with cognitive deficits and brain glucose metabolic alteration. However, the associations of glucose metabolic changes with cognitive dysfunction are less detailed. Here, we examined the brains of APP/presenilin 1 (PS1) transgenic (Tg) mice aged 2, 3.5, 5 and 8 months using (18)F-labed fluorodeoxyglucose ((18)F-FDG) microPET to assess age- and brain region-specific changes of glucose metabolism. FDG uptake was calculated as a relative standardized uptake value (SUVr). Morris water maze (MWM) was used to evaluate learning and memory dysfunction. We showed a glucose utilization increase in multiple brain regions of Tg mice at 2 and 3.5 months but not at 5 and 8 months. Comparisons of SUVrs within brains showed higher glucose utilization than controls in the entorhinal cortex, hippocampus, and frontal cortex of Tg mice at 2 and 3.5 months but in the thalamus and striatum at 3.5, 5 and 8 months. By comparing SUVrs in the entorhinal cortex and hippocampus, Tg mice were distinguished from controls at 2 and 3.5 months. In MWM, Tg mice aged 2 months shared a similar performance to the controls (prodromal-AD). By contrast, Tg mice failed training tests at 3.5 months but failed all MWM tests at 5 and 8 months, suggestive of partial or complete cognitive deficits (symptomatic-AD). Correlation analyses showed that hippocampal SUVrs were significantly correlated with MWM parameters in the symptomatic-AD stage. These data suggest that glucose metabolic disorder occurs before onset of AD signs in APP/PS1 mice with the entorhinal cortex and hippocampus affected first, and that regional FDG uptake increase can be an early biomarker for AD. Furthermore, hippocampal FDG uptake is a possible indicator for progression of Alzheimer's cognition after cognitive decline, at least in animals.

  12. Functional neuroimaging in epilepsy: FDG PET and ictal SPECT.

    PubMed Central

    Lee, D. S.; Lee, S. K.; Lee, M. C.

    2001-01-01

    Epileptogenic zones can be localized by F-18 fluorodeoxyglucose positron emission tomography (FDG PET) and ictal single-photon emission computed tomography(SPECT). In medial temporal lobe epilepsy, the diagnostic sensitivity of FDG PET or ictal SPECT is excellent, however, the sensitivity of MRI is so high that the incremental sensitivity by FDG PET or ictal SPECT has yet to be proven. When MRI findings are ambiguous or normal, or discordant with those of ictal EEG, FDG PET and ictal SPECT are helpful for localization without the need for invasive ictal EEG. In neocortical epilepsy, the sensitivities of FDG PET or ictal SPECT are fair. However, because almost a half of the patients are normal on MRI, FDG PET and ictal SPECT are helpful for localization or at least for lateralization in these non-lesional epilepsies in order to guide the subdural insertion of electrodes. Interpretation of FDG PET has been recently advanced by voxel-based analysis and automatic volume of interest analysis based on a population template. Both analytical methods confirmed the performance of previous visual interpretation results. Ictal SPECT was analyzed using subtraction methods(coregistered to MRI) and voxel-based analysis. Rapidity of injection of tracers, HMPAO versus ECD, and repeated ictal SPECT, which remain the technical issues of ictal SPECT, are detailed. PMID:11748346

  13. A voxel-based analysis of FDG-PET in traumatic brain injury: regional metabolism and relationship between the thalamus and cortical areas.

    PubMed

    García-Panach, Javier; Lull, Nuria; Lull, Juan José; Ferri, Joan; Martínez, Carlos; Sopena, Pablo; Robles, Montserrat; Chirivella, Javier; Noé, Enrique

    2011-09-01

    The objective was to study the correlations and the differences in glucose metabolism between the thalamus and cortical structures in a sample of severe traumatic brain injury (TBI) patients with different neurological outcomes. We studied 49 patients who had suffered a severe TBI and 10 healthy control subjects using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET). The patients were divided into three groups: a vegetative or minimally-conscious state (MCS&VS) group (n=17), which included patients who were in a vegetative or a minimally conscious state; an In-post-traumatic amnesia (In-PTA) group (n=12), which included patients in PTA; and an Out-PTA group (n=20), which included patients who had recovered from PTA. SPM5 software was used to determine the metabolic differences between the groups. FDG-PET images were normalized and four regions of interest were generated around the thalamus, precuneus, and the frontal and temporal lobes. The groups were parameterized using Student's t-test. Principal component analysis was used to obtain an intensity-estimated-value per subject to correlate the function between the structures. Differences in glucose metabolism in all structures were related to the neurological outcome, and the most severe patients showed the most severe hypometabolism. We also found a significant correlation between the cortico-thalamo-cortical metabolism in all groups. Voxel-based analysis suggests a functional correlation between these four areas, and decreased metabolism was associated with less favorable outcomes. Higher levels of activation of the cortico-cortical connections appear to be related to better neurological condition. Differences in the thalamo-cortical correlations between patients and controls may be related to traumatic dysfunction due to focal or diffuse lesions.

  14. F-18 HARV in flight with actuated nose strakes

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's F-18 from the Dryden Flight Research Center, Edwards, California, soars over the Mojave Desert while flying the third and final phase of the HARV (High Alpha Research Vehicle) program. A set of control surfaces called strakes were installed in the nose of the aircraft. The strakes, outlined in gold and white, provided improved yaw control at steep angles of attack. Normally folded flush, the units -- four feet long and six inches wide -- can be opened independently to interact with the nose vortices to produce large side forces for control. Testing involved evaluation of the strakes by themselves as well as combined with the aircraft's Thrust Vectoring System. The strakes were designed by NASA's Langley Research Center, then installed and flight tested at Dryden.

  15. F-18 HARV in flight with actuated nose strakes

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's F-18 from the Dryden Flight Research Center, Edwards, California, soars over the Mojave Desert while flying the current phase of the HARV (High Alpha Research Vehicle) program. A set of control surfaces called strakes were installed in the nose of the aircraft. The strakes, outlined in gold and white, provided improved yaw control at steep angles of attack. Normally folded flush, the units -- four feet long and six inches wide -- can be opened independently to interact with the nose vortices to produce large side forces for control. Testing involved evaluation of the strakes by themselves as well as combined with the aircraft's Thrust Vectoring System. The strakes were designed by NASA's Langley Research Center, then installed and flight tested at Dryden.

  16. Experiments With Recirculating Target for F-18 Production

    NASA Astrophysics Data System (ADS)

    Kiselev, M. Y.

    2003-08-01

    Approximately 10 ml of O-18 water was loaded in an apparatus containing a 5 ml storage vessel, pump, silver target attached to a cyclotron, filter, backpressure regulator, conductivity meter, several valves and ion exchange cartridges. The water was continuously pumped through the target during proton bombardment at a rate 5 ml/min. Continuous irradiation with beam current ranging from 10 to 50 uA was conducted while pressure, temperature and conductivity were continuously monitored. The results indicate that recirculating of the target water can increase production of F-18 in relation to consumed O-18 water material. It can also increase productivity by eliminating idle periods for re-filling the target. A backpressure regulator can precisely control target pressure. This method also allows for continuous monitoring of the target material temperature, pressure, conductivity and accumulated radioactivity. Results of these observations provide important information about target performance and physical processes taking place inside the target.

  17. FDG uptake in cervical facet subchondral cysts demonstrated by PET/CT.

    PubMed

    Lin, Eugene; Sicuro, Paul

    2008-04-01

    F-18 fluorodeoxyglucose (FDG) uptake in facet joints related to degenerative disease has been previously described. However, FDG uptake in subchondral cysts is the subject of this report. We describe 2 cases of intense focal FDG uptake in subchondral cysts in the cervical facets seen on positron emission tomography/computed tomography (PET/CT) exams. The location of these cysts immediately adjacent to the facet joints and the presence of associated facet joint degenerative changes are helpful in distinguishing this uptake from metastatic disease or other bone lesions.

  18. F-18 SRA in banked flight over lakebed

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's F/A-18 Hornet is seen here in a banked turn over Rogers Dry Lake in the Mojave desert on an early research flight. Currently being flown by NASA's Dryden Flight Research Center, Edwards, California, in a multi-year, joint NASA/DOD/industry program, the former Navy fighter has been modified into a unique Systems Research Aircraft (SRA) to investigate a host of new technologies in the areas of flight controls, airdata sensing and advanced computing. One of the more than 20 experiments being tested aboard the SRA F-18 is an advanced air data sensing system which uses a group of pressure taps flush-mounted on the forward fuselage to measure both altitude and wind speed and direction--critical data for flight control and research investigations. The Real-Time Flush Air Data Sensing system concept is being evaluated for possible use on the X-33 and X-34 resuable space-launch vehicles. The primary goal of the SRA program is to validate through flight research cutting-edge technologies which could benefit future aircraft and spacecraft by improving efficiency and performance, reducing weight and complexity, with a resultant reduction on development and operational costs.

  19. F-18 production with the TOP linac injector

    NASA Astrophysics Data System (ADS)

    Cianfarani, Cesidio; Cisbani, Evaristo; Orlandi, Gianluca; Frullani, Salvatore; Picardi, Luigi; Ronsivalle, Concetta

    2006-06-01

    ENEA and ISS (Italian National Institute of Health), are collaborating to develop a dedicated proton medical accelerator, TOP (Oncological Therapy with Protons) linac, consisting of a sequence of three pulsed linear accelerators. The 7 MeV injector can be used in three operating modes: Protontherapy and Radiobiology Mode—injecting low current proton beam into the TOP linac accelerating sections; Radioisotope Mode—generating an intense proton beam (8-10 mA, 50-100 μs, 30-100 Hz) to produce the positron-emitting radionuclide F18 for PET analyses. In the high current mode, at the exit of the injector the beam is guided through a magnetic quadrupoles channel to a target composed by a thin chamber (0.5 mm thick and 1 in. diameter) containing water enriched with O18. Production yield as well as total activity similar to these achieved with higher energy cyclotrons have been obtained. Environmental doses measured give indications on the shielding required for operation under current radioprotection regulations. Improvements are foreseen to optimize the production yield, the useful beam current and to better characterize gamma and neutron dose rates in the different operational modes.

  20. F-15B and F-18 SRA in flight

    NASA Technical Reports Server (NTRS)

    1993-01-01

    NASA's F-15B (upper right), later used for aerodynaic flight research, is seen here with the F/A-18B Systems Research Aircraft, on a flight from the Dryden Flight Research Facility, Edwards, California. Currently being flown by Dryden in a multi-year, joint NASA/DOD/industry program, the F/A-18B has been modified into a unique Systems Research Aircraft (SRA) to investigate a host of new technologies in the areas of flight controls, airdata sensing and advanced computing. One of the more than 20 experiments being tested aboard the SRA F-18 is an advanced air data sensing system which uses a group of pressure taps flush-mounted on the forward fuselage to measure both altitude and wind speed and direction--critical data for flight control and research investigations. The Real-Time Flush Air Data Sensing system concept is being evaluated for possible use on the X-33 and X-34 resuable space-launch vehicles. The primary goal of the SRA program is to validate through flight research cutting-edge technologies which could benefit future aircraft and spacecraft by improving effeciency and performance, reducing weight and complexity, with a resultant reduction on development and operational costs. NASA's F-15B aircraft is being used by Dryden as an aerospace research aircraft. Certain experiments can be placed on the Flight Test Fixture, which is mounted under the fuselage. The research projects can then be subjected to different aerodynamic loads, speeds and temperatures. The F-15B, No. 836, was acquired in 1993 and is also used at Dryden as a research support aircraft.

  1. F-18 Fluorodeoxyglucose Positron Emission Tomography study of Impaired Emotion Processing in First Episode Schizophrenia

    PubMed Central

    Choudhary, Mona; Kumar, Arvind; Tripathi, Madhavi; Bhatia, Triptish; Shivakumar, Venkataram; Beniwal, Ram Pratap; Gur, Ruben C.; Gur, Raquel E.; Nimgaonkar, Vishwajit L.

    2015-01-01

    Background Schizophrenia cases have consistently shown to have behavioural and neurofunctional abnormalities but studies during early course are scarce. The present work assesses the performance of acute first episode schizophrenia cases on correlation of a facial emotion perception task with brain function using Fluorine-18 Fluorodeoxyglucose (FDG) positron emission tomography (PET). Methods Twenty First episode schizophrenia cases and 20 matched healthy controls living in the community were enrolled. For cases, longest duration of illness was one year and treatment with neuroleptic did not exceed two weeks on the day of scan. To measure facial emotion perception (FEP) both groups were administered the Emotion battery from the Penn Computerized Battery followed by PET acquisition. SPM 8 analysis for group differences at p<0.001 was performed. Results Schizophrenia subjects showed hypoactivation of bilateral prefrontal cortices and fusiform gyrii, with significant hyperactivation of bilateral basal ganglia and left precuneus. Positive correlation of metabolism in prefrontal cortex and performance indices on emotions domain was seen. No correlation of CPZ equivalent days with metabolism in basal ganglia was observed. Conclusions The performance of schizophrenia cases on FEP task was significantly impaired in comparison to the control group. Brain regions implicated in emotion processing showed hypometabolism in cases as compared to controls. Failure of schizophrenia cases to optimally recruit brain circuitry may be contributing to deficits on FEP task. These findings suggest inherent deficits in neural circuitry of emotion processing in schizophrenia; devoid of confounding effects of neuroleptics and duration of illness. PMID:25655909

  2. Test-retest reproducibility for regional brain metabolic responses to lorazepam

    SciTech Connect

    Wang, G.J.; Volkow, N.D.; Overall, J. |||

    1996-05-01

    Changes in regional brain glucose metabolism as assessed with PET and FDG in response to acute administration of benzodiazepine agonists have been used as indicators of benzodiazepine-GABA receptor function. The purpose of this study was to assess the reproducibility of these responses. Sixteen healthy right-handed men were scanned with positron emission tomography (PET) and [F-18] fluorodeoxyglucose (FDG) twice: prior to placebo and prior to lorazepam (30 {mu}g/kg). The same double FDG procedure was repeated 6-8 weeks later to assess test-retest reproducibility. The regional absolute brain metabolic values obtained during the second evaluation were significantly lower than those obtained for the first evaluation regardless of condition (p {le} 0.001). Lorazepam significantly and consistently decreased whole brain metabolism and the magnitude as well as the regional pattern of the changes was comparable for both studies (12.3 {plus_minus} 6.9% and 13.7 {plus_minus} 7.4%). Lorazepam effects were largest in thalamus (22.2 {plus_minus} 8.9%). Relative metabolic measures ROI/global were highly reproducible both for drug as well as replication condition. This is the first study to measure test-retest reproducibility in regional brain metabolic response to a pharmacological challenge. While the global and regional absolute metabolic values were significantly lower for the repeated evaluation, the regional brain metabolic response to lorazepam was highly reproducible.

  3. Quantitative characterization of brain β-amyloid in 718 normal subjects using a joint PiB/FDG PET image histogram

    NASA Astrophysics Data System (ADS)

    Camp, Jon J.; Hanson, Dennis P.; Lowe, Val J.; Kemp, Bradley J.; Senjem, Matthew L.; Murray, Melissa E.; Dickson, Dennis W.; Parisi, Joseph E.; Petersen, Ronald C.; Robb, Richard A.; Holmes, David R.

    2016-03-01

    We have previously described an automated system for the co-registration of PiB and FDG PET images with structural MRI and a neurological anatomy atlas to produce region-specific quantization of cortical activity and amyloid burden. We also reported a global joint PiB/FDG histogram-based measure (FDG-Associated PiB Uptake Ratio - FAPUR) that performed as well as regional PiB ratio in stratifying Alzheimer's disease (AD) and Lewy Body Dementia (LBD) patients from normal subjects in an autopsy-verified cohort of 31. In this paper we examine results of this analysis on a clinically-verified cohort of 718 normal volunteers. We found that the global FDG ratio correlated negatively with age (r2 = 0.044) and global PiB ratio correlated positively with age (r2=0.038). FAPUR also correlated negatively with age (r2-.025), and in addition, we introduce a new metric - the Pearson's correlation coefficient (r2) of the joint PiB/FDG histogram which correlates positively (r2=0.014) with age. We then used these measurements to construct age-weighted Z-scores for all measurements made on the original autopsy cohort. We found similar stratification using Z-scores compared to raw values; however, the joint PiB/FDG r2 Z-score showed the greatest stratification ability.

  4. Correlation of (18)F-FDG PET and MR Apparent Diffusion Coefficient (ADC) Histogram Metrics with Survival in Diffuse Intrinsic Pontine Glioma: A Report from the Pediatric Brain Tumor Consortium.

    PubMed

    Zukotynski, Katherine; Vajapeyam, Sridhar; Fahey, Frederic H; Kocak, Mehmet; Brown, Douglas; Ricci, Kelsey; Onar-Thomas, Arzu; Fouladi, Maryam; Poussaint, Tina Young

    2017-03-30

    Rationale: To describe baseline (18)F-labeled 2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) voxel characteristics in pediatric diffuse intrinsic pontine glioma (DIPG) and to correlate these metrics with baseline magnetic resonance (MR) apparent diffusion coefficient (ADC) histogram metrics, progression-free survival (PFS) and overall survival (OS). Methods: Baseline brain FDG-PET and MR scans were obtained in 33 children from Pediatric Brain Tumor Consortium (PBTC) clinical DIPG trials. FDG-PET, post-gadolinium (PG) and ADC images were registered to baseline fluid attenuation inversion recovery (FLAIR) images. Three-dimensional regions of interest on FLAIR and PG images and FDG-PET and ADC histograms were generated. Metrics evaluated included peak number, skewness and kurtosis. Correlation between PET and ADC histogram metrics was evaluated. PET pixel values within the ROI for each tumor were plotted against ADC values. Association of these imaging markers with survival was described. Results: PET histograms were almost always unimodal (94% vs. 6% bimodal). None of the PET histogram parameters (skewness or kurtosis) had a significant association with PFS, although a higher PET PG skewness tended towards less favorable PFS (Hazard Ratio (95% CI)=3.48 (0.75, 16.28); P = 0.11). There was a significant association of higher ADC PG skewness with shorter PFS (Hazard Ratio (95% CI)=2.56 (1.11, 5.91); P = 0.028) and the suggestion that this also led to shorter OS (Hazard Ratio (95% CI)=2.18 (0.95, 5.04); P = 0.067). Higher ADC PG kurtosis tended towards shorter PFS (Hazard Ratio (95% CI)=1.30 (0.98, 1.74); P = 0.073). In a number of cases, PET and ADC pixel values were negatively correlated using the Pearson correlation coefficient. Further, the level of PET and ADC correlation was significantly positively associated with PFS; tumors with higher values of ADC-PET correlation had more favorable PFS (Hazard Ratio (95% CI)=0.17 (0.03, 0.89), P = 0

  5. Defining PET / CT Protocols With Optimized F18-FDG (Fluorodeoxyglucose) Dose, Focusing on Reduced Radiation Dose and Improved Image Quality

    ClinicalTrials.gov

    2015-08-19

    Malignant Neoplasm of Breast.; Hodgkin's Disease.; Non-Hodgkin Lymphoma, Follicular (Nodular).; Malignant Neoplasm of Bronchus and Lung.; Malignant Neoplasm of Colon.; Secondary Neoplasm Malignant and Unspecified Lymph Nodes.; Malignant Melanoma of the Skin.; Malignant Neoplasm of Small Intestine.

  6. Radiosynthesis of F-18-3-acetylcyclofoxy: A high affinity opiate antagonist

    SciTech Connect

    Channing, M.A.; Eckelman, W.C.; Bennett, J.M.; Burke, T.R. Jr.; Rice, K.C.; Larson, S.M.

    1985-05-01

    A convenient method for the preparation of F-18-3-acetylcyclofoxy (3-acetyl-6-deoxy-6-beta-F-18-fluoronaltrexone was developed. The method uses reactor-produced F-18-fluoride as its tetraethylammonium salt. F-18 fluoride is produced at the National Bureau of Standards nuclear reactor by the Li-6(n,..cap alpha..)H-3, 0-16(H-3,n) F-18 nuclear reaction. A sealed quartz tube containing enriched lithium carbonate (0.4 g) was irradiated in a neutron flux of 1.1 x 10/sup 14/ n/cm/sup 2//s for 2h to produce 80 mCi. The lithium is removed by cation exchange resin. The fluoride is then adsorbed on a strong anion exchange column which is rinsed to remove H-3 and any remaining cations. The F-18 is then eluted with tetraethylammonium hydroxide to produce tetraethylammonium fluoride (TEAF). The triflate of 3-acetyl-6-alpha-naltrexol, synthesized by reaction of the alcohol with trifluoromethanesulfonic anhydride was added in anhydrous acetonitrile to the dry F-18 TEAF containing 0.2 ..mu..mol F-19 TEAF. The mixture was refluxed for 15 minutes after which the product was purified by reversed phase chromatography. F-18-acetylcyclofoxy was prepared in 35% radiochemical yield. About 55% of the F-18 was lost by decay (36%) and by incomplete transfer (19%). The specific activity of the final product was approximately 50 Ci/mmol but the effective specific activity was approximately 25 Ci/mmol. Visualization of the basal ganglia in baboons was possible using PET. F-18 3-acetylcyclofoxy is the first positron-emitting opiate for which the active and inactive forms of naloxone were used to unequivocially demonstrate stereospecific displacement from opiate receptor-rich regions.

  7. Quantitative evaluation of two scatter correction techniques for (18)F-FDG brain PET/MR imaging in regard to MR-based attenuation correction.

    PubMed

    Teuho, Jarmo; Saunavaara, Virva; Tolvanen, Tuula; Tuokkola, Terhi; Karlsson, Antti; Tuisku, Jouni; Teräs, Mika

    2017-03-23

    minimal in non-time-of-flight (TOF) (18)F-FDG PET/MR brain imaging. The SSS algorithm was not affected significantly by MRAC. The performance of MCSSS algorithm is comparable but not superior to SSS, warranting further investigations of algorithm optimization and performance with different radiotracers and TOF imaging.

  8. Development of [F-18]-Labeled Amyloid Imaging Agents for PET

    SciTech Connect

    Mathis, CA

    2007-05-09

    The applicant proposes to design and synthesize a series of fluorine-18-labeled radiopharmaceuticals to be used as amyloid imaging agents for positron emission tomography (PET). The investigators will conduct comprehensive iterative in vitro and in vivo studies based upon well defined acceptance criteria in order to identify lead agents suitable for human studies. The long term goals are to apply the selected radiotracers as potential diagnostic agents of Alzheimer's disease (AD), as surrogate markers of amyloid in the brain to determine the efficacy of anti-amyloid therapeutic drugs, and as tools to help address basic scientific questions regarding the progression of the neuropathology of AD, such as testing the "amyloid cascade hypothesis" which holds that amyloid accumulation is the primary cause of AD.

  9. A New F-18 Prosthetic Group via an Oxime Coupling

    PubMed Central

    Carberry, Patrick; Lieberman, Brian P.; Ploessl, Karl; Choi, Seok R.; Haase, Danniebelle N.; Kung, Hank F.

    2011-01-01

    A novel fluorine-18 prosthetic ligand, 5-(1,3-dioxolan-2-yl)-2-(2-(2-(2- fluoroethoxy)ethoxy)ethoxy)pyridine [18F]2, has been synthesized. The prosthetic ligand is formed in high radiochemical yield (rcy = 71 ± 2 %, n = 3) with excellent radiochemical purity (rcp = 99 ± 1 %, n = 3) in a short reaction time (10 min). [18F]2 is a small, neutral, organic complex, easily synthesized in four steps from a readily available starting material. It can be anchored onto a target molecule containing an aminooxy functional group under acidic conditions by way of an oxime bond. We report herein two examples [18F]23 and [18F]24, potential imaging agents for β-amyloid plaques, which were labeled with this prosthetic group. This approach could be used for labeling proteins and peptides containing an aminooxy group. Biodistribution in male ICR mice for both oxime labeled complexes [18F]23 and [18F]24 were compared to that of the known β-amyloid plaque indicator, [18F]-AV-45, florbetapir 1. Oximes [18F]23 and [18F]24 are larger in size and therefore should reduce the blood-brain barrier (BBB) penetration. The brain uptake for oxime [18F]23 appeared to be reduced, but still retained some capability to cross the BBB. Oxime [18F]24 showed promising results after 2 min post injection (0.48 % dose/gram), however the uptake increased after 30 min post injection (0.92 % dose/gram) suggesting an in-vivo decomposition/metabolism of compound [18F]24. We have demonstrated a general protocol for the fluoride-18 labeling with a new prosthetic ligand [18F]2 that is tolerant towards several functional groups and is formed via chemoselective oxime coupling. PMID:21452846

  10. Numerical simulation of the flow about the F-18 HARV at high angle of attack

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.

    1994-01-01

    This report summarizes research done over the past two years as part of NASA Grant NCC 2-729. This research has been aimed at validating numerical methods for computing the flow about the complete F-18 HARV at alpha = 30 deg and alpha = 45 deg. At 30 deg angle of attack, the flow about the F-18 is dominated by the formation, and subsequent breakdown, of strong vortices over the wing leading-edge extensions (LEX). As the angle of attack is increased to alpha = 45 deg, the fuselage forebody of the F-18 contains significant laminar and transitional regions which are not present at alpha = 30 deg. Further, the flow over the LEX at alpha = 45 deg is dominated by an unsteady shedding in time, rather than strong coherent vortices. This complex physics, combined with the complex geometry of a full aircraft configuration, provides a challenge for current computational fluid dynamics (CFD) techniques. The following sections present the numerical method and grid generation scheme that was used, a review of prior research done to numerically model the F-18 HARV, and a discussion of the current research. The current research is broken into two main topics: the effect of engine-inlet mass-flow rate on the F-18 vortex breakdown position, and the results using a refined F-18 computational model to compute the flow at alpha = 30 deg and alpha = 45 deg.

  11. Numerical simulation of the flow about the F-18 HARV at high angle of attack

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.

    1995-01-01

    This research has been aimed at validating numerical methods for computing the flow about the complete F-18 HARV at alpha = 30 deg and alpha = 45 deg. At 30 deg angle of attack, the flow about the F-18 is dominated by the formation, and subsequent breakdown, of strong vortices over the wing leading-edge extensions (LEX). As the angle of attack is increased to alpha = 45 deg, the fuselage forebody of the F-18 contains significant laminar and transitional regions which are not present at alpha = 30 deg. Further, the flow over the LEX at alpha = 45 deg is dominated by an unsteady shedding in time, rather than strong coherent vortices. This complex physics, combined with the complex geometry of a full-aircraft configuration, provides a challenge for current computational fluid dynamics (CFD) techniques. The following sections present the numerical method and grid generation scheme that was used, a review of prior research done to numerically model the F-18 HARV, and a discussion of the current research. The current research is broken into three main topics; the effect of engine-inlet mass-flow rate on the F-18 vortex breakdown position, the results using a refined F-18 computational model to compute the flow at alpha = 30 deg and alpha = 45 deg, and research done using the simplified geometry of an ogive-cylinder configuration to investigate the physics of unsteady shear-layer shedding. The last section briefly summarizes the discussion.

  12. Metabolism of human gliomas: Assessment with H-1 MR spectroscopy and F-18 fluorodeoxyglucose PET

    SciTech Connect

    Alger, J.R.; Frank, J.A.; Bizzi, A.; Fulham, M.J.; DeSouza, B.X.; Duhaney, M.O.; Inscoe, S.W.; Black, J.L.; van Zijl, P.C.; Moonen, C.T. , Bethesda, MD )

    1990-12-01

    Localized hydrogen-1 magnetic resonance (MR) spectroscopy and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) were employed to obtain metabolic information from intracranial gliomas. Advantages and difficulties associated with comparison of results from the two modalities were realized. Forty patients were studied with H-1 MR spectroscopy. MR signal intensities from lactate, N-acetylaspartate (NAA), choline, and creatine from a volume of interest containing the tumor and a contralateral volume were obtained and evaluated. NAA signal intensities were generally decreased in the tumor spectra, and choline signal intensities were elevated. H-1 MR spectroscopy was unsuccessful in eight patients, and FDG PET scans were not obtained in four of the patients with successful MR spectroscopic examinations. Lactate signal intensity was detected in 10 of the 28 patients who had successful H-1 MR spectroscopic and FDG PET studies. Lactate signal intensities were observed in lesions shown at FDG PET to be hypermetabolic, as well as in lesions found to be hypometabolic.

  13. The brain metabolic activity after resuscitation with liposome-encapsulated hemoglobin in a rat model of hypovolemic shock.

    PubMed

    Rao, Geeta; Hedrick, Andria F; Yadav, Vivek R; Xie, Jun; Hussain, Alamdar; Awasthi, Vibhudutta

    2015-09-01

    We examined the effect of resuscitation with liposome-encapsulated hemoglobin (LEH) on cerebral bioenergetics in a rat model of 45% hypovolemia. The rats were resuscitated with isovolemic LEH or saline after 15 minutes of shock and followed up to 6 hours. Untreated hypovolemic rats received no fluid. The cerebral uptake of F-18-fluorodeoxyglucose (FDG) was measured by PET, and at 6 hours, the brain was collected for various assays. Hypovolemia decreased cellular adenosine triphosphate (ATP), phosphocreatine, nicotinamide adenine dinucleotide (NAD)/NADH ratio, citrate synthase activity, glucose-6-phosphate, and nerve growth factor (NGF), even when FDG uptake remained unchanged. The FDG uptake was reduced by saline, but not by LEH infusion. The reduced FDG uptake in saline group was associated with a decrease in hexokinase I expression. The LEH infusion effectively restored ATP content, NAD/NADH ratio, and NGF expression, and reduced the hypovolemia-induced accumulation of pyruvate and ubiquitinated proteins; in comparison, saline was significantly less effective. The LEH infusion was associated with low pH and high anion gap, indicating anionic gap acidosis. The results suggest that hypovolemic shock perturbs glucose metabolism at the level of pyruvate utilization, resulting in deranged cerebral energy stores. The correction of volume and oxygen deficits by LEH recovers the cerebral metabolism and creates a prosurvival phenotype.

  14. Expression of key glycosphingolipid biosynthesis-globo series pathway genes in Escherichia coli F18-resistant and Escherichia coli F18-sensitive piglets.

    PubMed

    Dong, W H; Dai, C H; Sun, L; Wang, J; Sun, S Y; Zhu, G Q; Wu, S L; Bao, W B

    2016-08-01

    A pioneering study showed that the glycosphingolipid biosynthesis-globo series pathway genes (FUT1, FUT2, ST3GAL1, HEXA, HEXB, B3GALNT1 and NAGA) may play an important regulatory role in resistance to Escherichia coli F18 in piglets. Therefore, we analysed differential gene expression in 11 tissues of two populations of piglets sensitive and resistant respectively to E. coli F18 and the correlation of differential gene expression in duodenal and jejunal tissues. We found that the mRNA expression of the seven genes was relatively high in spleen, liver, lung, kidney, stomach and intestinal tract; the levels in thymus and lymph nodes were lower, with the lowest levels in heart and muscle. FUT2 gene expression in the duodenum and jejunum of the resistant population was significantly lower than that in the sensitive group (P < 0.01). ST3GAL1 gene expression was also significantly lower in the duodenum of the resistant population than in the sensitive group (P < 0.05). No significant differences were observed among the remaining genes. The expression level of FUT1 was extremely significantly positively correlated with FUT2 and B3GALNT1 expression (P < 0.01) and also had a significant positive correlation with NAGA expression (P < 0.05). The expression level of FUT2 had extremely significant positive correlations with FUT1, ST3GAL1 and B3GALNT1 (P < 0.01). These results suggest that FUT2 plays an important role in E. coli F18 resistance in piglets. FUT1, ST3GAL1, B3GALNT1 and NAGA may also participate in the mechanism of resistance to E. coli F18.

  15. Effectiveness of F18+ Fimbrial Antigens Released by a Novel Autolyzed Salmonella Expression System as a Vaccine Candidate against Lethal F18+ STEC Infection

    PubMed Central

    Won, Gayeon; Lee, John H.

    2016-01-01

    Porcine edema disease (ED) caused by Shiga toxin 2e producing Escherichia coli expressing F18ab+ fimbriae (F18ab+STEC) frequently occurs in post-weaned piglets, resulting in a significant economic loss in swine industries worldwide. In the present study, we proposed an efficient prevention scheme against ED in which the attenuated Salmonella Typhimurium inactivated by the E-mediated cell lysis to deliver target antigens, FedF and FedA, which function in fimbrial-mediated adhesion and as a major subunit of F18ab+fimbriae, respectively. The co-expression of FedA and FedF protein with outer membrane protein A signal peptide was confirmed in the resultant strains JOL1460 and JOL1464 by immunoblot analysis. Immunization with the candidate strains in mice led to the significant generation of immunoglobulin (Ig) G, specific to both antigens and secretory IgA specific to FedF (P < 0.05). The titers of IgG isotypes, IgG1 and IgG2a, used as markers for T-helpers (Th)-2 and Th-1lymphocytes, respectively, also significantly increased in the immunized group (P < 0.05). The increase in CD3+CD4+ T lymphocyte subpopulation and in vitro proliferative activity was observed in in vivo stimulated splenocytes, which indicated the immunostimulatory effect of the candidate strains. Moreover, the immunized mice were completely protected from a lethal challenge against wild-type F18+STEC whereas 28% of mice died in the non-immunized group. This study demonstrated that the inactivated Salmonella system could efficiently release FedF and FedA and induce robust immune responses specific to the target antigens, which is sufficient to protect the mice from the lethal challenge. PMID:27920758

  16. [Cloning and expression of F18 fimbrial operon gene clusters from enterotoxigenic Escherichia coli and their bioactivity].

    PubMed

    Zhang, Jian-Jun; Zhu, Guo-Qiang

    2007-10-01

    The fed operon gene clusters with each size of 5.6kb, encoding the F18ab or F18ac fimbriae, was amplified respectively by high fidelity PCR using the genomic DNA templates from F18 fimbriae E. coli strains 107/86 or 2134P. The PCR products with the restriction enzyme sites at each end were digested and then cloned into the vector pET-22b (+), the recombinant plamids with the inserts of both type of fed gene clusters were constructed and screened, further confirmed by the means of combination with restriction endonuclease analysis and sequencing. The both types of fimbriae F18ab and F18ac were expressed efficiently in the E. coli BL21 (DE3) after proper concentration of IPTG induction. Expressed fimbriae were revealed and confirmed by transmissible electromicroscope observation. The both fimbriae F18ab and F18ac were isolated and purified from the recombinant E. coli, and only a single major band of protein with size of approximately 15kDa was visualized in Coomassie blue-stained gels after SDS-PAGE. The rabbits sera with high titer of anti-F18 fimbriae were detected after being immunized with the purified F18ab or F18ac fimbriae. The results of combination of agglutination assay with Western blotting showed that the sera directed against both fimbriae F18ab and F18ac reacted positively with the F18 fimbriae from both wild E. coli 107/86 and 2134P. Small intestine epithelial cells with F18 fimbriae receptors, which were from post-weaning piglets with the genotypes of FUT1 gene both M307(GG) and M307(AG), were prepared and tested for the adherence of E. coli expressing F18 fimbriae under the microscopic examination. Adhesion and adhesion inhibition test showed both of the recombinant E. coli expressing F18ab or F18ac fimbriae respectively could adhere to the jejunal epithelial cells in vitro as E. coli 107/86 and 2134p did. The both of anti-sera directed against fimbriae F18ab or F18ac respectively can efficiently inhibit the fimbriae-mediated post-weaning piglet

  17. STM study of C60F18 high dipole moment molecules on Au(111)

    NASA Astrophysics Data System (ADS)

    Bairagi, K.; Bellec, A.; Chumakov, R. G.; Menshikov, K. A.; Lagoute, J.; Chacon, C.; Girard, Y.; Rousset, S.; Repain, V.; Lebedev, A. M.; Sukhanov, L. P.; Svechnikov, N. Yu.; Stankevich, V. G.

    2015-11-01

    Scanning tunneling microscopy and spectroscopy studies of C60F18 molecules deposited on Au(111) are reported and compared to C60 molecules both at liquid helium temperature and room temperature (RT). Whereas adsorption and electronic properties of C60F18 single molecules were studied at low temperature (LT), self-assemblies were investigated at RT. In both cases, the fluorine atoms of the C60F18 molecules are pointed towards the surface. Individual C60F18 molecules on Au(111) have a HOMO-LUMO gap of 2.9 eV. The self-assembled islands exhibit a close-packed hexagonal lattice with amorphous borders. The comparison with C60 molecules clearly demonstrates the influence of the C60F18 electric dipole moment (EDM) on the electronic properties of single molecules and on the thermodynamics of self-assembled islands. Besides, the apparent height value of a separate molecule increases in a self-assembly environment as a result of a depolarization phenomenon.

  18. Ground-Recorded Sonic Boom Signatures of F-18 Aircraft in Formation Flight

    NASA Technical Reports Server (NTRS)

    Bahm, Catherine M.; Haering, Edward A., Jr.

    1996-01-01

    Two F-18 aircraft were flown, one above the other, in two formations, in order for the shock systems of the two aircraft to merge and propagate to the ground. The first formation had the canopy of the lower F-18 in the tail shock of the upper F-18 (called tail-canopy). The second formation had the canopy of the lower F- 18 in the inlet shock of the upper F-18 (called inlet-canopy). The flight conditions were Mach 1.22 and an altitude of 23,500 ft . An array of five sonic boom recorders was used on the ground to record the sonic boom signatures. This paper describes the flight test technique and the ground level sonic boom signatures. The tail-canopy formation resulted in two, separated, N-wave signatures. Such signatures probably resulted from aircraft positioning error. The inlet-canopy formation yielded a single modified signature; two recorders measured an approximate flattop signature. Loudness calculations indicated that the single inlet-canopy signatures were quieter than the two, separated tail-canopy signatures. Significant loudness occurs after a sonic boom signature. Such loudness probably comes from the aircraft engines.

  19. Results From F-18B Stability and Control Parameter Estimation Flight Tests at High Dynamic Pressures

    NASA Technical Reports Server (NTRS)

    Moes, Timothy R.; Noffz, Gregory K.; Iliff, Kenneth W.

    2000-01-01

    A maximum-likelihood output-error parameter estimation technique has been used to obtain stability and control derivatives for the NASA F-18B Systems Research Aircraft. This work has been performed to support flight testing of the active aeroelastic wing (AAW) F-18A project. The goal of this research is to obtain baseline F-18 stability and control derivatives that will form the foundation of the aerodynamic model for the AAW aircraft configuration. Flight data have been obtained at Mach numbers between 0.85 and 1.30 and at dynamic pressures ranging between 600 and 1500 lbf/sq ft. At each test condition, longitudinal and lateral-directional doublets have been performed using an automated onboard excitation system. The doublet maneuver consists of a series of single-surface inputs so that individual control-surface motions cannot be correlated with other control-surface motions. Flight test results have shown that several stability and control derivatives are significantly different than prescribed by the F-18B aerodynamic model. This report defines the parameter estimation technique used, presents stability and control derivative results, compares the results with predictions based on the current F-18B aerodynamic model, and shows improvements to the nonlinear simulation using updated derivatives from this research.

  20. Auditory adaptation to sound intensity in conscious rats: 2-[F-18]-fluoro-2-deoxy-D-glucose PET study.

    PubMed

    Jang, Dong Pyo; Lee, Kyoung Min; Lee, Sang-Yoon; Oh, Jin-Hwan; Park, Chan-Woong; Kim, In Young; Kim, Young-Bo; Cho, Zang-Hee

    2012-03-07

    Despite the importance of the adaptive process for discriminating the broad range of sound intensity, there have been few systemic investigations targeting the auditory mechanisms. In this study, the adaptation effect of sound intensity on the change in glucose metabolism in rat brains was examined using a PET technique. In the first experiment, broadband white noise sound (40, 60, 80, or 100 dB sound pressure level) was given for 30 min after an 2-[F-18]-fluoro-2-deoxy-D-glucose injection in an awake condition. In the second experiment, sound stimuli with an intensity modulation of 0, 0.5, and 5.0 Hz in frequency and at three intensity levels were used for examining the metabolism change according to the short time scale variation of the sound intensity. As a result, the metabolic activities in the bilateral cochlear nucleus, superior olivary complexes, and inferior colliculus were proportional to the sound intensity level, whereas the bilateral auditory cortical areas unexpectedly decreased as the sound intensity level increased in the first experiment. In the second experiment, the glucose metabolism in the auditory cortex was higher at 0.5 and 5.0 Hz modulation frequency than the 0.0 Hz modulation frequency, while retaining an inverse relationship with the sound intensity. The metabolism in inferior colliculus was higher at 5.0 Hz modulation frequency than 0.0 and 0.5 Hz modulation frequencies. Taken together, the auditory cortex metabolism seemed to be actively adapted to the average sound intensity, which indicates that it plays an important role in processing the broad range to sound intensity more than the other nucleus of the auditory pathway. Especially, this study demonstrated that the sound intensity-dependent glucose metabolism can be seen in a small rodent's brain stem level using 2-[F-18]-fluoro-2-deoxy-D-glucose PET functional neuroimaging.

  1. F-18 SRA closeup of nose cap showing Advanced L-Probe Air Data Integration experiment

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This L-shaped probe mounted on the forward fuselage of a modified F-18 Systems Research Aircraft was the focus of an air data collection experiment flown at NASA's Dryden Flight Research Center, Edwards, California. The Advanced L-Probe Air Data Integration (ALADIN) experiment focused on providing pilots with angle-of-attack and angle-of-sideslip information as well as traditional airspeed and altitude data from a single system. For the experiment, the probes--one mounted on either side of the F-18's forward fuselage--were hooked to a series of four transducers, which relayed pressure measurements to an on-board research computer.

  2. The poststall nonlinear dynamics and control of an F-18: A preliminary investigation

    NASA Technical Reports Server (NTRS)

    Patten, William N.

    1988-01-01

    The successful high angle of attack (HAOA) operation of fighter aircraft will necessarily require the introduction of a new onboard control methodology that address the nonlinearity of the system when flown at the stall/poststall limits of the craft's flight envelope. As a precursor to this task, a researcher endeavored to familarize himself with the dynamics of one specific aircraft, the F-18, when it is flown at HAOA. This was accomplished by conducting a number of real time flight sorties using the NASA-Langley Research Center's F-18 simulator, which was operated with a pilot in the loop. In addition to developing a first hand familarity with the aircraft's dynamic characteristic at HAOA, work was also performed to identify the input/output operational footprint of the F-18's control surfaces. This investigator proposes to employ the nonlinear models of the plant identified this summer in a subsequent research effort that will make it possible to fly the F-18 effectively at poststall angles of attack. The controller design used there will rely on a new technique proposed by this investigator that provides for the automatic generation of online optimal control solutions for nonlinear dynamic systems.

  3. Measurement of Radiative Proton Capture on F18 and Implications for Oxygen-Neon Novae

    NASA Astrophysics Data System (ADS)

    Akers, C.; Laird, A. M.; Fulton, B. R.; Ruiz, C.; Bardayan, D. W.; Buchmann, L.; Christian, G.; Davids, B.; Erikson, L.; Fallis, J.; Hager, U.; Hutcheon, D.; Martin, L.; Murphy, A. St. J.; Nelson, K.; Spyrou, A.; Stanford, C.; Ottewell, D.; Rojas, A.

    2013-06-01

    The rate of the F18(p,γ)Ne19 reaction affects the final abundance of the γ-ray observable radioisotope F18, produced in novae. However, no successful measurement of this reaction exists and the rate used is calculated from incomplete information on the contributing resonances. Of the two resonances thought to play a significant role, one has a radiative width estimated from the assumed analogue state in the mirror nucleus, F19. The second does not have an analogue state assignment at all, resulting in an arbitrary radiative width being assumed. Here, we report the first successful direct measurement of the F18(p,γ)Ne19 reaction. The strength of the 665 keV resonance (Ex=7.076MeV) is found to be over an order of magnitude weaker than currently assumed in nova models. Reaction rate calculations show that this resonance therefore plays no significant role in the destruction of F18 at any astrophysical energy.

  4. Complete Genome Sequence of Salmonella enterica Serovar Enteritidis Bacteriophage f18SE, Isolated in Chile

    PubMed Central

    Segovia, Cristopher; Vasquez, Ignacio; Maracaja-Coutinho, Vinicius; Robeson, James

    2015-01-01

    Bacteriophage f18SE was isolated from poultry sewage in Olmue, Chile, and lytic activity was demonstrated against Salmonella enterica serovar Enteritidis and serovar Pullorum strains. This bacteriophage has a 41,868-bp double-stranded DNA (ds-DNA) genome encoding 53 coding sequences (CDSs) and belongs to the family Siphoviridae, subfamily Jerseyvirinae. PMID:26450716

  5. Targeting Pod Effects on Weapons Release from F-18C Hornet

    DTIC Science & Technology

    2008-01-01

    70 L I S T O F T A B L E S Table 1. Number of surface patches used on models ...from the F-18C Hornet 6. AUTHOR( S ) - Godiksen III, William H. 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME( S ...AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10

  6. F18 EF5 PET/CT Imaging in Patients with Brain Metastases from Breast Cancer

    DTIC Science & Technology

    2012-07-01

    disease . One had progressive lung disease limiting her ability to lay supine for imaging, and the second patient developed leptomeningeal spread...patient developed progressive leptomeningeal disease and required spinal radiation leaving her fatigued and unable to complete the study. A third patient...of her disease and declined further imaging studies. A third patient has been enrolled and is scheduled for imaging later in August 2012. 15

  7. Structural loads testing on the Active Aeroelastic Wing F-18 in the Flight Loads Laboratory at NASA'

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Structural loads testing on the Active Aeroelastic Wing F-18 in the Flight Loads Laboratory at NASA's Dryden flight Research Center, Edwards, California. The heavily modified and instrumented F-18A entered the Loads Lab in mid-March, 2001, for fit checks of loads hardware and instrumentation checkout prior to initiation of actual structural loads testing. The F-18A underwent loads testing on its modified wings for almost six months, followed by extensive systems tests and simulation before flight tests began.

  8. F-18 SRA closeup of nose cap showing new flush air data system sensor holes

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The small numbers on the nose of this F-18 aircraft at NASA's Dryden Flight Research Center, Edwards, California, show the locations of 11 tiny holes which are an integral part of a new air data system installed on the aircraft. The Real-Time Flush Air Data Sensing system measures the speed and direction of the airflow past the aircraft and its altitude, similar to standard air data systems. It incorporates flush-mounted pressure taps, miniature transducers and an advanced research computer to give pilots more accurate information than standard systems employing external probes can provide. Developed by Dryden researchers in cooperation with Honeywell's Research and Technology Center, Minneapolis, Minnesota, the system was flight tested on Dryden's Systems Research Aircraft (SRA) last year, and is now being used as a precise reference for other air data systems currently being evaluated on the modified F-18.

  9. The measurement and improvement of the lateral agility of the F-18

    NASA Technical Reports Server (NTRS)

    Eggold, David P.; Valasek, John; Downing, David R.

    1991-01-01

    The effect of vehicle configuration and flight control system performance on the roll agility of a modern fighter aircraft has been investigated. A batch simulation of a generic F-18 Hornet was used to study the roll agility as measured by the time to roll through 90 deg metric. Problems discussed include definition of agility, factors affecting the agility of a vehicle, the development of the time to roll through 90 deg agility metric, and a simulation experiment. It is concluded that the integral of stability or wind axis roll rate should be used as a measure of the roll measure traversed. The time through roll angle 90 deg metric is considered to be a good metric for measuring the transient performance aspect of agility. Roll agility of the F-18, as measured by 90 deg metric, can be improved by 10 to 30 percent. Compatible roll and rudder actuator rates can significantly affect 90 deg agility metric.

  10. Pet imaging of human pituitary 5-HT2 receptors with F-18 setoperone

    SciTech Connect

    Fischman, A.J.; Bonab, A.A.; Babich, J.W.

    1995-05-01

    Serotonin (5-HT) receptors play an important role in the regulation of pituitary function. In particular, 5HT agonists stimulate ACTH, {beta}-endorphin, prolactin and growth hormone secretion but inhibit TSH release. 5-HT binding sites have been identified by autoradiographic studies of rat and human pituitary. In the present investigation, we used PET with F-18 setoperone to image 5-HT2 receptors in normal humans. Setoperone, a piperidine derivative with potent 5-HT2 receptor blocking properties was labelled with F-18 by nucleophilic substitution on the nitro derivative. After HPLC purification, specific activity was between 10,000 and 15,000 mCi/{mu} mole and radiochemical purity was >98%. Six healthy male volunteers were injected with 5-7 mCi of F-18. Setoperone and serial PET images and arterial blood samples were collected over 2 hrs. Specific binding to 5-HT2 receptors in the frontal cortex (FC), striatum (ST) and pituitary (P) was quantitated using the cerebellum (C) as reference. The tracer showed clear retention in FC, ST and P (known to contain a high density of 5-HT2 receptors) relative to C (known to be devoid of 5-HT2 receptors). In all subjects, FC/C, ST/C and P/C ratios increased during the first hr. and remained stable thereafter. For FC and ST, the ratios reached similar values; 3.92{plus_minus}0.73 and 3.53{plus_minus}0.32. For pituitary, a significantly higher ratio, was measured at all times; 6.53{plus_minus}1.82 (p<0.01). These results indicate that F-18 setoperone is an effective PET radiopharmaceutical for imaging 5-HT2 receptors in the human pituitary. Future applications of this agent could provide important new insights into neuroendocrine function.

  11. Ground-recorded sonic boom signatures of F-18 aircraft formation flight

    NASA Technical Reports Server (NTRS)

    Bahm, Catherine M.; Haering, Edward A., Jr.

    1995-01-01

    Two F-18 aircraft were flown, one above the other, in two formations, in order for the shock systems of the two aircraft to merge and propagate to the ground. The first formation had the canopy of the lower F-18 in the inlet shock of the upper F-18 (called inlet-canopy). The flight conditions were Mach 1.22 and an altitude of 23,500 ft. An array of five sonic boom recorders was used on the ground to record the sonic boom signatures. This paper describes the flight test technique and the ground level sonic boom signatures. The tail-canopy formation resulted in two, separated, N-wave signatures. Such signatures probably resulted from aircraft positioning error. The inlet-canopy formation yielded a single modified signature; two recorders measured an approximate flattop signature. Loudness calculations indicated that the single inlet-canopy signatures were quieter than the two, separated tail-canopy signatures. Significant loudness occurs after a sonic boom signature. Such loudness probably comes from the aircraft engines.

  12. Occipital Hypometabolism on FDG PET/CT Scan in a Child with Hodgkin's Lymphoma

    PubMed Central

    Tatci, Ebru; Ozmen, Ozlem; Gokcek, Atila; Demir, Haci Ahmet; Gulleroglu, Nadide Basak

    2016-01-01

    It is known that Fluorodeoxyglucose (FDG) Positron Emission/Computed Tomography (PET/CT) images may be helpful for evaluation of brain function in newborns. Here we described the fluorine-18 [18-F] FDG PET/CT imaging findings of encephalomalacia due to perinatal asphyxia in a child with refractory Hodgkin's Lymphoma (HL) who underwent PET/CT scan to stage the primary disease. Prominent hypometabolism was incidentally detected in the occipital regions bilaterally apart from the FDG uptakes in the malign lymphatic infiltrations. This case highlights the potential coexistence of a malignancy and a functional brain disorder. PMID:27965911

  13. Synthesis of Fluorine-Containing Phosphodiesterase 10A (PDE10A) Inhibitors and the In Vivo Evaluation of F-18 Labeled PDE10A PET Tracers in Rodent and Nonhuman Primate

    PubMed Central

    Li, Junfeng; Zhang, Xiang; Jin, Hongjun; Fan, Jinda; Flores, Hubert; Perlmutter, Joel S.; Tu, Zhude

    2015-01-01

    A series of fluorine-containing PDE10A inhibitors were designed and synthesized to improve the metabolic stability of [11C]MP-10. Twenty of the 22 new analogues had high potency and selectivity for PDE10A: 18a–j, 19d–j, 20a–b, and 21b had IC50 values <5 nM for PDE10A. Seven F-18 labeled compounds [18F]18a–e, [18F]18g, and [18F]20a were radiosynthesized by 18F-introduction onto the quinoline rather than the pyrazole moiety of the MP-10 pharmacophore and performed in vivo evaluation. Biodistribution studies in rats showed ~2-fold higher activity in the PDE10A-enriched striatum than nontarget brain regions; this ratio increased from 5 to 30 min postinjection, particularly for [18F]18a–d and [18F]20a. Micro-PET studies of [18F]18d and [18F]20a in nonhuman primates provided clear visualization of striatum with suitable equilibrium kinetics and favorable metabolic stability. These results suggest this strategy may identify a 18F-labeled PET tracer for quantifying the levels of PDE10A in patients with CNS disorders including Huntington’s disease and schizophrenia. PMID:26430878

  14. F-18 chase craft with NASA test pilots Schneider and Fulton

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Ed Schneider, (left), is the project pilot for the F-18 High Angle of Attack program at NASA's Dryden Flight Research Center, Edwards, California. He has been a NASA research pilot at Dryden since 1983. In addition to his assignment with the F-18 High Angle of Attack program, Schneider is a project pilot for the F-15B aeronautical research aircraft, the NASA NB-52B launch aircraft, and the SR-71 'Blackbird' aircraft. He is a Fellow and was the 1994 President of the Society of Experimental Test Pilots. In 1996 he was awarded the NASA Exceptional Service Medal. Schneider is seen here with Fitzhugh L. Fulton Jr., (right), who was a civilian research pilot at Dryden. from August 1, 1966, until July 3, 1986, following 23 years of service as a pilot in the U.S. Air Force. Fulton was the project pilot on all early tests of the 747 Shuttle Carrier Aircraft (SCA) used to air launch the Space Shuttle prototype Enterprise in the Approach and Landing Tests (ALT) at Dryden in l977. For his work in the ALT program, Fulton received NASA's Exceptional Service Medal. He also received the Exceptional Service Medal again in 1983 for flying the 747 SCA during the European tour of the Space Shuttle Enterprise. During his career at Dryden, Fulton was project pilot on NASA's NB-52B launch aircraft used to air launch a variety of piloted and unpiloted research aircraft, including the X-15s and lifting bodies. He flew the XB-70 prototype supersonic bomber on both NASA-USAF tests and NASA research flights during the late 1960s, attaining speeds exceeding Mach 3. He was also a project pilot on the YF-12A and YF-12C research program from April 14, 1969, until September 25, 1978. The F/A-18 Hornet seen behind them is used primarily as a safety chase and support aircraft at NASA's Dryden Flight Research Center, Edwards, Calif. As support aircraft, the F-18's are used for safety chase, pilot proficiency and aerial photography. As a safety chase aircraft, F-18's, flown by research pilots

  15. FDG-PET-positive ovarian thecoma with GLUT5 expression: Five cases.

    PubMed

    Bono, Yukiko; Mizumoto, Yasunari; Nakamura, Mitsuhiro; Iwadare, Jyunpei; Obata, Takeshi; Fujiwara, Hiroshi

    2017-03-01

    Positron emission tomography (PET) with fluorodeoxyglucose F18 ((18) F-FDG) is useful for detecting malignancies, but benign lesions occasionally have false-positive (18) F-FDG uptake. Here, we report the cases of five postmenopausal women with solid ovarian tumors suspected to be ovarian cancer on magnetic resonance imaging and (18) F-FDG uptake. Mean age of the five patients was 57 years (range, 53-65 years). Average early standardized uptake value (SUV) of (18) F-FDG was 5.76 (range, 2.2-12.0) and delayed SUV was 6.56 (range, 2.4-13.8). In all five patients, frozen section diagnosis at surgery was thecoma, and bilateral salpingo-oophorectomy was performed. On immunohistochemistry, immunoreactive glucose transporter 5 (GLUT5) expression was detected in thecoma tissues. This case shows that thecoma sometimes has positive (18) F-FDG uptake on positron emission tomography-computed tomography (PET-CT), indicating the need for caution regarding false-positive PET-CT in patients with benign solid ovarian tumor.

  16. F-18 HARV in high-alpha flight with smoke generator

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The NASA Dryden Flight Research Center, Edwards, California, used an F-18 Hornet fighter aircraft as its High Angle-of-Attack (alpha) Research Vehicle (HARV) in a three-phased flight research program lasting from April 1987 until September 1996. The aircraft completed 385 research flights and demonstrated stabilized flight at angles of attack between 65 and 70 degrees using thrust vectoring vanes, a research flight control system, and (eventually) forebody strakes (hinged structures on the forward side of the fuselage to provide control by interacting with vortices that are generated at high angles of attack, and thus create side forces). This combination of technologies provided carefree handling of a fighter aircraft in a part of the flight regime that was otherwise very dangerous. Flight research with the HARV increased our understanding of flight at high angles of attack, enabling designers of U.S. fighter aircraft to design airplanes that will fly safely in portions of the flight envelope that pilots previously had to avoid. Angle of attack (alpha) is an aeronautical term that describes the angle of an aircraft body and wings relative to its actual flightpath. During maneuvers, pilots often fly at extreme angles of attack -- with the nose pitched up while the aircraft continues in its original direction. This can lead to conditions in which the airflow becomes separated over large regions of the lifting surfaces (airfoils). These conditions can result in insufficient lift to maintain altitude or control of the aircraft and a corresponding increase in drag -- a condition known as stall. (In an ideal situation, the airflow would remain attached to the airfoil surface from leading to trailing edge; this would reduce the drag that impedes the movement of the airfoil through the atmosphere. When the airflow separates from the surface, this increases the drag and can lead to a stall.) The HARV was developed from a pre-production model of the F-18, a single

  17. Changes in Cervical Cancer FDG Uptake During Chemoradiation and Association With Response

    SciTech Connect

    Kidd, Elizabeth A.; Thomas, Maria; Siegel, Barry A.; Dehdashti, Farrokh; Grigsby, Perry W.

    2013-01-01

    Purpose: Previous research showed that pretreatment uptake of F-18 fluorodeoxyglucose (FDG), as assessed by the maximal standardized uptake value (SUV{sub max}) and the variability of uptake (FDG{sub hetero}), predicted for posttreatment response in cervical cancer. In this pilot study, we evaluated the changes in SUV{sub max} and FDG{sub hetero} during concurrent chemoradiation for cervical cancer and their association with post-treatment response. Methods and Materials: Twenty-five patients with stage Ib1-IVa cervical cancer were enrolled. SUV{sub max}, FDG{sub hetero}, and metabolic tumor volume (MTV) were recorded from FDG-positron emission tomography (PET)/computed tomography (CT) scans performed pretreatment and during weeks 2 and 4 of treatment and were evaluated for changes and association with response assessed on 3-month post-treatment FDG-PET/CT. Results: For all patients, the average pretreatment SUV{sub max} was 17.8, MTV was 55.4 cm{sup 3}, and FDG{sub hetero} was -1.33. A similar decline in SUV{sub max} was seen at week 2 compared with baseline and week 4 compared with week 2 (34%). The areas of highest FDG uptake in the tumor remained relatively consistent on serial scans. Mean FDG{sub hetero} decreased during treatment. For all patients, MTV decreased more from week 2 to week 4 than from pretreatment to week 2. By week 4, the average SUV{sub max} had decreased by 57% and the MTV had decreased by 30%. Five patients showed persistent or new disease on 3-month post-treatment PET. These poor responders showed a higher average SUV{sub max}, larger MTV, and greater heterogeneity at all 3 times. Week 4 SUV{sub max} (P=.037), week 4 FDG{sub hetero} (P=.005), pretreatment MTV (P=.008), and pretreatment FDG{sub hetero} (P=.008) were all significantly associated with post-treatment PET response. Conclusions: SUV{sub max} shows a consistent rate of decline during treatment and declines at a faster rate than MTV regresses. Based on this pilot study

  18. Analysis of the Metabolic and Structural Brain Changes in Patients With Torture-Related Post-Traumatic Stress Disorder (TR-PTSD) Using ¹⁸F-FDG PET and MRI.

    PubMed

    Zandieh, Shahin; Bernt, Reinhard; Knoll, Peter; Wenzel, Thomas; Hittmair, Karl; Haller, Joerg; Hergan, Klaus; Mirzaei, Siroos

    2016-04-01

    Many people exposed to torture later suffer from torture-related post-traumatic stress disorder (TR-PTSD). The aim of this study was to analyze the morphologic and functional brain changes in patients with TR-PTSD using magnetic resonance imaging (MRI) and positron emission tomography (PET). This study evaluated 19 subjects. Thirteen subcortical brain structures were evaluated using FSL software. On the T1-weighted images, normalized brain volumes were measured using SIENAX software. The study compared the volume of the brain and 13 subcortical structures in 9 patients suffering from TR-PTSD after torture and 10 healthy volunteers (HV). Diffusion-weighted imaging (DWI) was performed in the transverse plane. In addition, the 18F-FDG PET data were evaluated to identify the activity of the elected regions. The mean left hippocampal volume for the TR-PTSD group was significantly lower than in the HV group (post hoc test (Bonferroni) P < 0.001). There was a significant difference between the gray matter volume of the patients with TR-PTSD and the HV group (post hoc test (Bonferroni) P < 0.001). The TR-PTSD group showed low significant expansion of the ventricles in contrast to the HV group (post hoc test (Bonferroni) P < 0.001). Diffusion-weighted imaging revealed significant differences in the right frontal lobe and the left occipital lobe between the TR-PTSD and HV group (post hoc test (Bonferroni) P < 0.001). Moderate hypometabolism was noted in the occipital lobe in 6 of the 9 patients with TR-PTSD, in the temporal lobe in 1 of the 9 patients, and in the caudate nucleus in 5 of the 9 patients. In 2 cases, additional hypometabolism was observed in the posterior cingulate cortex and in the parietal and frontal lobes. The findings from this study show that TR-PTSD might have a deleterious influence on a set of specific brain structures. This study also demonstrated that PET combined with MRI is sensitive in detecting possible metabolic and structural

  19. Analysis of the Metabolic and Structural Brain Changes in Patients With Torture-Related Post-Traumatic Stress Disorder (TR-PTSD) Using 18F-FDG PET and MRI

    PubMed Central

    Zandieh, Shahin; Bernt, Reinhard; Knoll, Peter; Wenzel, Thomas; Hittmair, Karl; Haller, Joerg; Hergan, Klaus; Mirzaei, Siroos

    2016-01-01

    Abstract Many people exposed to torture later suffer from torture-related post-traumatic stress disorder (TR-PTSD). The aim of this study was to analyze the morphologic and functional brain changes in patients with TR-PTSD using magnetic resonance imaging (MRI) and positron emission tomography (PET). This study evaluated 19 subjects. Thirteen subcortical brain structures were evaluated using FSL software. On the T1-weighted images, normalized brain volumes were measured using SIENAX software. The study compared the volume of the brain and 13 subcortical structures in 9 patients suffering from TR-PTSD after torture and 10 healthy volunteers (HV). Diffusion-weighted imaging (DWI) was performed in the transverse plane. In addition, the 18F-FDG PET data were evaluated to identify the activity of the elected regions. The mean left hippocampal volume for the TR-PTSD group was significantly lower than in the HV group (post hoc test (Bonferroni) P < 0.001). There was a significant difference between the gray matter volume of the patients with TR-PTSD and the HV group (post hoc test (Bonferroni) P < 0.001). The TR-PTSD group showed low significant expansion of the ventricles in contrast to the HV group (post hoc test (Bonferroni) P < 0.001). Diffusion-weighted imaging revealed significant differences in the right frontal lobe and the left occipital lobe between the TR-PTSD and HV group (post hoc test (Bonferroni) P < 0.001). Moderate hypometabolism was noted in the occipital lobe in 6 of the 9 patients with TR-PTSD, in the temporal lobe in 1 of the 9 patients, and in the caudate nucleus in 5 of the 9 patients. In 2 cases, additional hypometabolism was observed in the posterior cingulate cortex and in the parietal and frontal lobes. The findings from this study show that TR-PTSD might have a deleterious influence on a set of specific brain structures. This study also demonstrated that PET combined with MRI is sensitive in detecting possible metabolic and

  20. Numerical simulation of the flow about an F-18 aircraft in the high-alpha regime

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.; Rizk, Yehia M.

    1994-01-01

    The current research is aimed at developing and extending numerical methods to accurately predict the high Reynolds number flow about the NASA F-18 HARV at large angles of attack. The resulting codes are validated by comparison of the numerical results with in-flight aerodynamic measurements and flow visualization obtained on the HARV. Further, computations have been used to provide an analysis and numerical optimization of a pneumatic slot blowing concept, and a mechanical strake concept, for use as potential forebody flow control devices in improving high-alpha maneuverability.

  1. New Cyclotron Targetry to Enhance F-18 clinical Position Emission Tomography

    SciTech Connect

    J. Michael Doster

    2008-12-19

    This project proposes to develop cyclotron targets that produce F-18 for clinical Positron Emission Tomography (PET) at significantly higher rates than that available from current targetry. This production rate of 18F is directly proportional to the beam current. Higher beam currents would result in increased 18F production but would be accompanied by higher heat loads to the target. The beam power available in most commercial cyclotrons exceeds the heat removal capacity of current target technology by a factor of two to four, significantly limiting the production rate of Fluorine-18.

  2. 4-[F-18]fluoroproline: A potential tracer for collagen synthesis. Radiosynthesis and biological evaluation

    SciTech Connect

    Hamacher, K.; Herz, M.; Truckenbrodt, R.

    1996-05-01

    Proline is an important constituent of the structural protein collagen. It has been shown that its fluorinated analogs (2S,4S)- and particularly (2S,4R)-4-fluoroproline are also incorporated into collagen (Gottlieb et al., Biochemistry (1965), 4: 2507). 4-[F-18]fluoroproline is therefore a potential probe for studying abnormal collagen synthesis e. g. in tumors, lung fibrosis and liver cirrhosis. We have evaluated the two diastereomeric forms using a transplantable osteosarcoma in mice as an in vivo model for elevated collagen synthesis, and a MCF 7 mamma carcinoma cell line for monolayer incubation studies.

  3. FDG positron emission computed tomography in a study of aphasia

    SciTech Connect

    Metter, E.J.; Wasterlain, C.G.; Kuhl, D.E.; Hanson, W.R.; Phelps, M.E.

    1981-08-01

    Positron emission computed tomography (PECT) using 18F-2-fluoro-2-deoxy-D-glucose (FDG) was used to investigate the correlations between clinical status, anatomy (as described by CT), and metabolism in five patients with stable aphasia resulting from ischemic cerebral infarction. Local cerebral metabolic activity was diminished in an area larger than the area of infarction demonstrated by CT. In one patient, FDG PECT revealed a metabolic lesion that probably caused the aphasic syndrome and was not apparent by CT. The data suggest that reliance on CT in delineating the extent of the brain lesion in aphasia or other neuropsychological defects can be misleading; FDG PECT may provide important additional information. Two patients with similar metabolic lesions had very different clinical syndromes, showing that even when currently available methods are combined, major gaps remain in clinicoanatomical correlations in aphasia.

  4. An Overview of the NASA F-18 High Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.; Pahle, Joseph W.; Wilson, R. Joseph; Flick, Bradley C.; Rood, Richard L.

    1996-01-01

    This paper gives an overview of the NASA F-18 High Alpha Research Vehicle. The three flight phases of the program are introduced, along with the specific goals and data examples taken during each phase. The aircraft configuration and systems needed to perform the disciplinary and inter-disciplinary research are discussed. The specific disciplines involved with the flight research are introduced, including aerodynamics, controls, propulsion, systems, and structures. Decisions that were made early in the planning of the aircraft project and the results of those decisions are briefly discussed. Each of the three flight phases corresponds to a particular aircraft configuration, and the research dictated the configuration to be flown. The first phase gathered data with the baseline F-18 configuration. The second phase was the thrust-vectoring phase. The third phase used a modified forebody with deployable nose strakes. Aircraft systems supporting these flights included extensive instrumentation systems, integrated research flight controls using flight control hardware and corresponding software, analog interface boxes to control forebody strakes, a thrust-vectoring system using external post-exit vanes around axisymmetric nozzles, a forebody vortex control system with strakes, and backup systems using battery-powered emergency systems and a spin recovery parachute.

  5. Thrust Vectoring on the NASA F-18 High Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.; Pahle, Joseph W.

    1996-01-01

    Investigations into a multiaxis thrust-vectoring system have been conducted on an F-18 configuration. These investigations include ground-based scale-model tests, ground-based full-scale testing, and flight testing. This thrust-vectoring system has been tested on the NASA F-18 High Alpha Research Vehicle (HARV). The system provides thrust vectoring in pitch and yaw axes. Ground-based subscale test data have been gathered as background to the flight phase of the program. Tests investigated aerodynamic interaction and vane control effectiveness. The ground-based full-scale data were gathered from static engine runs with image analysis to determine relative thrust-vectoring effectiveness. Flight tests have been conducted at the NASA Dryden Flight Research Center. Parameter identification input techniques have been developed. Individual vanes were not directly controlled because of a mixer-predictor function built into the flight control laws. Combined effects of the vanes have been measured in flight and compared to combined effects of the vanes as predicted by the cold-jet test data. Very good agreement has been found in the linearized effectiveness derivatives.

  6. Performance of an Electro-Hydrostatic Actuator on the F-18 Systems Research Aircraft

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    1997-01-01

    An electro-hydrostatic actuator was evaluated at NASA Dryden Flight Research Center, Edwards, California. The primary goal of testing this actuator system was the flight demonstration of power-by-wire technology on a primary flight control surface. The electro-hydrostatic actuator uses an electric motor to drive a hydraulic pump and relies on local hydraulics for force transmission. This actuator replaced the F-18 standard left aileron actuator on the F-18 Systems Research Aircraft and was evaluated throughout the Systems Research Aircraft flight envelope. As of July 24, 1997 the electro-hydrostatic actuator had accumulated 23.5 hours of flight time. This paper presents the electro-hydrostatic actuator system configuration and component description, ground and flight test plans, ground and flight test results, and lessons learned. This actuator performs as well as the standard actuator and has more load capability than required by aileron actuator specifications of McDonnell- Douglas Aircraft, St. Louis, Missouri. The electro-hydrostatic actuator system passed all of its ground tests with the exception of one power-off test during unloaded dynamic cycling.

  7. F-18 SRA closeup of nose cap showing new flush air data system sensor holes

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Small numbers on the nose cap of this F-18 Systems Research Aircraft at NASA's Dryden Flight Research Center, Edwards, California, show the locations of 11 tiny holes, which are an integral part of a new air data system installed on the aircraft. The Real-Time Flush Air Data Sensing system measures the speed and direction of the airflow past the aircraft and its altitude, similar to standard air data systems. It differs from those systems by incorporating flush-mounted pressure taps, miniature transducers and an advanced research computer to give the pilot more accurate information than systems employing external probes provide. Stephen A. Whitmore of Dryden's Aerodynamics Branch won NASA's Space Act Award for his development of the Real-Time Flush Air Data Sensing system. The award honors projects which are scientifically or technologically significant to the aeronautics and space community. The system was flight tested on the modified F-18 last year, and is now being used as a precise reference system for other air data systems currently being evaluated on the aircraft.

  8. A comparison study of 11C-methionine and 18F-fluorodeoxyglucose positron emission tomography-computed tomography scans in evaluation of patients with recurrent brain tumors

    PubMed Central

    Sharma, Rajnish; D’Souza, Maria; Jaimini, Abhinav; Hazari, Puja Panwar; Saw, Sanjeev; Pandey, Santosh; Singh, Dinesh; Solanki, Yachna; Kumar, Nitin; Mishra, Anil K.; Mondal, Anupam

    2016-01-01

    Introduction: 11C-methonine ([11C]-MET) positron emission tomography-computed tomography (PET-CT) is a well-established technique for evaluation of tumor for diagnosis and treatment planning in neurooncology. [11C]-MET reflects amino acid transport and has been shown to be more sensitive than magnetic resonance imaging (MRI) in stereotactic biopsy planning. This study compared fluorodeoxyglucose (FDG) PET-CT and MET PET-CT in the detection of various brain tumors. Materials and Methods: Sixty-four subjects of brain tumor treated by surgery, chemotherapy, and/or radiotherapy were subjected to [18F]-FDG, [11C]-MET, and MRI scan. The lesion was analyzed semiquantitatively using tumor to normal contralateral ratio. The diagnosis was confirmed by surgery, stereotactic biopsy, clinical follow-up, MRI, or CT scans. Results: Tumor recurrence was found in 5 out of 22 patients on [F-18] FDG scan while [11C]-MET was able to detect recurrence in 18 out of 22 patients in low-grade gliomas. Two of these patients were false positive for the presence of recurrence of tumor and later found to be harboring necrosis. Among oligodendroglioma, medulloblastoma and high-grade glioma out of 42 patients 39 were found to be concordant MET and FDG scans. On semiquantitative analysis, mean T/NT ratio was found to be 2.96 ± 0.94 for lesions positive for recurrence of tumors and 1.18 ± 0.74 for lesions negative for recurrence of tumor on [11C]-MET scan. While the ratio for FDG scan on semiquantitative analysis was found to be 2.05 ± 1.04 for lesions positive for recurrence of tumors and 0.52 ± 0.15 for lesions negative for recurrence of tumors. Conclusion: The study highlight that [11C]-MET is superior to [18F]-FDG PET scans to detect recurrence in low-grade glioma. A cut-off value of target to nontarget value of 1.47 is a useful parameter to distinguish benign from malignant lesion on an [11C]-MET Scan. Both [18F]-FDG and [11C]-MET scans were found to be useful in high-grade astrocytoma

  9. Effects of nonlinear unsteady aerodynamics on performance, stability and control of an F-18 configuration

    NASA Astrophysics Data System (ADS)

    Lin, Guofeng

    Large-amplitude forced oscillation data for an F-18 configuration are analyzed with two modeling methods: Fourier functional analysis to form the indicial integrals, and a generalized dynamic aerodynamic model for stability and control analysis. The indicial integral is first applied to calculate the pitch damping parameter for comparison with the conventional forced oscillation test. It is shown that the reduced frequency affects the damping much more strongly than the test amplitude. Using the indicial integral models in a flight simulation code for an F-18 configuration, it is found that the configuration with unsteady aerodynamics becomes unstable in pitch if the pitch rate is high, in contrast to the quasi-steady configuration which depends mainly on the instantaneous angle of attack. In a pitch-up maneuver in the post-stall regime the configuration with unsteady aerodynamics can stay at a high pitch attitude and angle of attack without losing altitude for a much longer duration than the quasi-steady model. However, the speed will decrease faster because of higher drag. The newly developed generalized dynamic aerodynamic model is of the nonlinear algebraic form with the coefficients being determined from a set of large amplitude oscillatory experimental data by using least-square fitting. The resulting model coefficients are functions of the reduced frequency and amplitude. The new aerodynamic models have been verified with data in harmonic oscillation with a smaller amplitude and in constant pitch-rate motions. The new algebraic models are especially useful in stability and control analysis, and are used in bifurcation analysis and control studies for the same F-18 HARV configuration. The results show significant differences in the equilibrium surfaces and dynamic stability. It is also shown that control gains developed with the conventional quasi-steady aerodynamic data may not be adequate when the effect of unsteady aerodynamics is significant. A numerical

  10. Brain glucose overexposure and lack of acute metabolic flexibility in obesity and type 2 diabetes: a PET-[18F]FDG study in Zucker and ZDF rats.

    PubMed

    Liistro, Tiziana; Guiducci, Letizia; Burchielli, Silvia; Panetta, Daniele; Belcari, Nicola; Pardini, Silvia; Del Guerra, Alberto; Salvadori, Piero A; Iozzo, Patricia

    2010-05-01

    Brain glucose exposure may complicate diabetes and obesity. We used positron emission tomography with (18)F-fluorodeoxyglucose in Zucker obese, diabetic, and control rats to determine the contributions of blood glucose mass action versus local mechanisms in regulating central glucose disposal in fasted and acutely glucose-stimulated states, and their adaptations in obesity and diabetes. Our study data indicate that brain glucose uptake is dependent on both local and mass action components, and is stimulated by acute glucose intake in healthy rats. In diseased animals, the organ was chronically overexposed to glucose, due to high fasting glucose uptake, almost abolishing the physiologic response to glucose loading.

  11. Cranberry extract inhibits in vitro adhesion of F4 and F18(+)Escherichia coli to pig intestinal epithelium and reduces in vivo excretion of pigs orally challenged with F18(+) verotoxigenic E. coli.

    PubMed

    Coddens, Annelies; Loos, Michaela; Vanrompay, Daisy; Remon, Jean Paul; Cox, Eric

    2017-01-20

    F4(+)E. coli and F18(+)E. coli infections are an important threat for pig industry worldwide. Antibiotics are commonly used to treat infected piglets, but the emerging development of resistance against antibiotics raises major concerns. Hence, alternative therapies to prevent pigs from F4(+)E. coli and F18(+)E. coli infections need to be developed. Since cranberry previously showed anti-adhesive activity against uropathogenic E. coli, we aimed to investigate whether cranberry extract could also inhibit binding of F4(+)E. coli and F18(+)E. coli to pig intestinal epithelium. Using the in vitro villus adhesion assay, we found that low concentrations of cranberry extract (20μg or 100μg/ml) have strong inhibitory activity on F4(+)E. coli (75.3%, S.D.=9.31 or 95.8%, S.D.=2.56, respectively) and F18(+)E. coli adherence (100% inhibition). This effect was not due to antimicrobial activity. Moreover, cranberry extract (10mg or 100mg) could also abolish in vivo binding of F4 and F18 fimbriae to the pig intestinal epithelium in ligated loop experiments. Finally, two challenge experiments with F18(+)E. coli were performed to address the efficacy of in-feed or water supplemented cranberry extract. No effect could be observed in piglets that received cranberry extract only in feed (1g/kg or 10g/kg). However, supplementation of feed (10g/kg) and drinking water (1g/L) significantly decreased excretion and diarrhea. The decreased infection resulted in a decreased serum antibody response indicating reduced exposure to F18(+)E. coli.

  12. F-18 HARV in flight close-up of actuated nose strakes

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's F-18 from the Dryden Flight Research Center, Edwards, California, soars over the Mojave Desert while flying the third phase of the HARV (High Alpha Research Vehicle) program. This is a closer look at the set of control surfaces called strakes that were installed in the nose of the aircraft. The strakes, outlined in gold and white, are expected to provide improved yaw control at steep angles of attack. Normally folded flush, the units -- four feet long and six inches wide -- can be opened independently to interact with the nose vortices to produce large side forces for control. Testing involved evaluation of the strakes by themselves as well as combined with the aircraft's Thrust Vectoring System. The strakes were designed by NASA's Langley Research Center, then installed and flight tested at Dryden.

  13. F-18 HARV in flight close-up of actuated nose strakes

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's F-18 from the Dryden Flight Research Center, Edwards, California, soars over the Mojave Desert while flying the third phase of the HARV (High Alpha Research Vehicle) program. This is a closer look at the set of control surfaces called strakes that were installed in the nose of the aircraft. The strakes, outlined in gold and white, provided improved yaw control at steep angles of attack. Normally folded flush, the units -- four feet long and six inches wide -- can be opened independently to interact with the nose vortices to produce large side forces for control. Testing involved evaluation of the strakes by themselves as well as combined with the aircraft's Thrust Vectoring System. The strakes were designed by NASA's Langley Research Center, then installed and flight tested at Dryden.

  14. F-18 HARV on ramp close-up of actuated nose strakes

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Outlined with gold stripes are the hinged nose strakes, modifications made to NASA's F-18 HARV (High Alpha Research Vehicle) at the Dryden Flight Research Center, Edwards, California. Actuated Nose Strakes for Enhanced Rolling (ANSER) were installed to fly the third and final phase in the HARV flight test project. Normally folded flush, the units -- four feet long and six inches wide -- can be opened independently to interact with the nose vortices to produce large side forces for control. Early wind tunnel tests indicated that the strakes would be as effective in yaw control at high angles of attack as rudders are at lower angles. Testing involved evaluation of the strakes by themselves as well as combined with the aircraft's Thrust Vectoring System. The strakes were designed by NASA's Langley Research Center, then installed and flight tested at Dryden.

  15. Numerical simulation of the flow about the F-18 HARV at high angle of attack

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.

    1994-01-01

    As part of NASA's High Alpha Technology Program, research has been aimed at developing and extending numerical methods to accurately predict the high Reynolds number flow about the NASA F-18 High Alpha Research Vehicle (HARV) at large angles of attack. The HARV aircraft is equipped with a bidirectional thrust vectoring unit which enables stable, controlled flight through 70 deg angle of attack. Currently, high-fidelity numerical solutions for the flow about the HARV have been obtained at alpha = 30 deg, and validated against flight-test data. It is planned to simulate the flow about the HARV through alpha = 60 deg, and obtain solutions of the same quality as those at the lower angles of attack. This report presents the status of work aimed at extending the HARV computations to the extreme angle of attack range.

  16. FDG-PET Contributions to the Pathophysiology of Memory Impairment.

    PubMed

    Segobin, Shailendra; La Joie, Renaud; Ritz, Ludivine; Beaunieux, Hélène; Desgranges, Béatrice; Chételat, Gaël; Pitel, Anne Lise; Eustache, Francis

    2015-09-01

    Measurement of synaptic activity by Positron Emission Tomography (PET) and its relation to cognitive functions such as episodic memory, working memory and executive functions in healthy humans and patients with neurocognitive disorders have been well documented. In this review, we introduce the concept of PET imaging that allows the observation of a particular biological process in vivo through the use of radio-labelled compounds, its general use to the medical world and its contributions to the understanding of memory systems. We then focus on [(18)F]-2-fluoro-2-deoxy-D-glucose (FDG-PET), the radiotracer that is used to measure local cerebral metabolic rate of glucose that is indicative of synaptic activity in the brain. FDG-PET at rest has been at the forefront of functional neuroimaging over the past 3 decades, contributing to the understanding of cognitive functions in healthy humans and how these functional patterns change with cognitive alterations. We discuss methodological considerations that are important for optimizing FDG-PET imaging data prior to analysis. We then highlight the contribution of FDG-PET to the understanding of the patterns of functional differences in non-degenerative pathologies, normal ageing, and age-related neurodegenerative disorders. Through reasonable temporal and spatial resolution, its ability to measure synaptic activity in the whole brain, independently of any specific network and disease, makes it ideal to observe regional functional changes associated with memory impairment.

  17. [(18)F]FDG PET signal is driven by astroglial glutamate transport.

    PubMed

    Zimmer, Eduardo R; Parent, Maxime J; Souza, Débora G; Leuzy, Antoine; Lecrux, Clotilde; Kim, Hyoung-Ihl; Gauthier, Serge; Pellerin, Luc; Hamel, Edith; Rosa-Neto, Pedro

    2017-03-01

    Contributions of glial cells to neuroenergetics have been the focus of extensive debate. Here we provide positron emission tomography evidence that activation of astrocytic glutamate transport via the excitatory amino acid transporter GLT-1 triggers widespread but graded glucose uptake in the rodent brain. Our results highlight the need for a reevaluation of the interpretation of [(18)F]FDG positron emission tomography data, whereby astrocytes would be recognized as contributing to the [(18)F]FDG signal.

  18. Computational Investigation of an F-18 Aircraft in the High-Alpha Regime

    NASA Technical Reports Server (NTRS)

    Murman, Scott M.; Rizk, Yehia M.; Kutler, Paul (Technical Monitor)

    1994-01-01

    One of the goals of NASA's High Alpha Technology Program is to provide flight-validated design methods for the high-angle-of-attack regime. This is an integrated effort utilizing computational simulations, wind tunnel experiments, and flight tests using the F-18 High Alpha Research Vehicle (HARV). The dominant physics of the aircraft flows in the high alpha regime changes as the angle of attack is increased. At moderate angle of attack the flow is characterized by boundary layer separation and the formation of tight vortices. As the angle of attack is increased, these vortices break down producing unsteady wakes. With further increase in angle of attack, the, vortex breakdown moves progressively upstream until the entire flowfield becomes dominated by the unsteady wake. Previous computational work has demonstrated the ability to simulate flows about the F-18 HARV in the medium-to-high angle of attack range, where the flowfield is characterized by the vortex formation and subsequent breakdown. This paper extends the previous computations to include conditions of 45 degree angle of attack where the flowfield becomes dominated by the unsteady wake shed from the Leading Edge Extension (LEX), and regions of laminar and transitional flow appear on the fuselage forebody. A more complete surface geometry is utilized, which includes the features of the engine nacelle, inlet diffuser, and the boundary layer diverter duct. A volume grid sensitivity study was also performed to extend the accuracy of the results, most notably in the prediction of the LEX vortex breakdown position. This paper includes comparisons of computational results with both in-flight surface pressure measurements, and flow visualizations of the surface and off-surface particle trajectories.

  19. Diagnostic evaluation of solitary pulmonary nodules (SPNs) using PET-FDG imaging

    SciTech Connect

    Gupta, N.; Chandramouli, B.; Reeb, S.

    1994-05-01

    We have reported high sensitivity of PET-FDG imaging in detecting malignancy in SPNs. We now report clinical utility of PET-FDG imaging in pre-intervention workup of 66 pts (age 24-89 yrs) with radiographically indeterminate SPNs (0.5-3 cm) in size. All pts had PET imaging performed 1 hr after injection of 10 mCi of F-18 FDG. Images were analyzed qualitatively and semi-quantitatively to compute DUR indices using ROI analysis. Final diagnosis was established by histology in 65/66 pts (thoracotomy 47, needle biopsy 13, bronchoscopy 5, stable nodule 1). PET-FDG imaging demonstrates sensitivity, specificity and predictive accuracy of 94%, 87% and 92% respectively. All 3 false negative cases were SPNs <1.5 cm in size and histologically adenoca. True positive malignant SPNs were adenoca 18, small cell 5, squamous cell 12, nonsmall cell 7, and others 6. Among 15 benign lesions (granuloma 6, histoplasmosis 4, nonspecific inflammation 2, hamartoma 1, stable nodule 1, organizing pneumonia 1), 2 false positive cases were seen in histoplasmosis. In 10 patients hilar/mediastinal lymph node lesions were accurately classified as benign (5) or malignant (5). Mean DUR in malignant lesions (5.41{plus_minus}2.63) was significantly greater (p value <0.001) than benign lesions (1.12{plus_minus}0.78). In conclusion, PET-FDG imaging is highly accurate in differentiating benign from malignant lung modules and lymph node lesions. PET-FDG imaging may thus optimize surgical management of pts with radiographically SPNs.

  20. Diagnostic Ability of FDG-PET/CT in the Detection of Malignant Pleural Effusion

    PubMed Central

    Nakajima, Reiko; Abe, Koichiro; Sakai, Shuji

    2015-01-01

    Abstract We investigated the role of F-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) for the differential diagnosis of malignant and benign pleural effusion. We studied 36 consecutive patients with histologically proven cancer (excluding malignant mesothelioma) who underwent FDG-PET/CT for suspected malignant pleural effusion. Fourteen patients had cytologically proven malignant pleural effusion and the other 22 patients had either negative cytology or clinical follow-up, which confirmed the benign etiology. We examined the maximum standardized uptake values (SUVmax) of pleural effusion and the target-to-normal tissue ratio (TNR), calculated as the ratio of the pleural effusion SUVmax to the SUVmean of the normal tissues (liver, spleen, 12th thoracic vertebrae [Th12], thoracic aorta, and spinalis muscle). We also examined the size and density (in Hounsfield units) of the pleural effusion and pleural abnormalities on CT images. TNR (Th12) and increased pleural FDG uptake compared to background blood pool were significantly more frequent in cases with malignant pleural effusion (P < 0.05 for both). The cutoff TNR (Th12) value of >0.95 was the most accurate; the sensitivity, specificity, and accuracy for this value were 93%, 68%, and 75%, respectively. FDG-PET/CT can be a useful method for the differential diagnosis of malignant and benign pleural effusion. PMID:26200610

  1. Fluorination of aromatic compounds by cleavage of aryl-tin bonds with F-18 F/sub 2/ and CH/sub 3/COOF

    SciTech Connect

    Adam, M.J.; Abeysekera, B.F.; Ruth, T.J.; Jivan, S.; Pate, B.D.

    1984-01-01

    Direct fluorination of aromatic nuclei is difficult since the reaction is usually accompanied by unselective, partial, or total replacement of hydrogen. By attaching the tri-n-butyltin moiety to one position of the ring one can achieve an enhanced reactivity and site selectivity toward electrophilic fluorination. The intent of this study was to demonstrate the utility of the fluorodestannylation reaction for fluorine labelling of aromatic compounds and to compare F/sub 2/ and acetyl hypofluorite as the fluorinating agents. Thus, eight stannylated aromatic compounds (1-8) were synthesized via lithium halogen exchange of the bromo precursor and subsequent transmetallation using tri-n-butyltin chloride. The stannylated substrates were treated with F-18 F/sub 2/ and -78/sup 0/C and CH/sub 3/COOF at room temperature. Both reagents gave good yields of labelled aryl fluorides. Overall, acetyl hypofluorite gave more consistent yields (approx. =70%), while F/sub 2/ gave more variable yields (54-95%). This method is currently being extended to label more complex systems such as L-Dopa with F-18 for brain studies with positron emission tomography. The authors have successfully stannylated Dopa on the ring and fluorination studies of this substrate are underway.

  2. SU-E-J-258: Prediction of Cervical Cancer Treatment Response Using Radiomics Features Based On F18-FDG Uptake in PET Images

    SciTech Connect

    Altazi, B; Fernandez, D; Zhang, G; Biagioli, M; Moros, E; Moffitt, H. Lee

    2015-06-15

    Purpose: Radiomics have shown potential for predicting treatment outcomes in several body sites. This study investigated the correlation between PET Radiomics features and treatment response of cervical cancer outcomes. Methods: our dataset consisted of a cohort of 79 patients diagnosed with cervical cancer, FIGO stage IB-IVA, age range 25–86 years, (median age at diagnosis: 50 years) all treated between: 2009–14 with external beam radiation therapy to a dose range between: 45–50.4 Gy (median= 45 Gy), concurrent cisplatin chemotherapy and MRI-based brachytherapy to a dose of 20–30 Gy (median= 28 Gy). Metabolic Tumor Volume (MTV) in patient’s primary site was delineated on pretreatment PET/CT by two board certified Radiation Oncologists. The features extracted from each patient’s volume were: 26 Co-occurrence matrix (COM) Feature, 11 Run-Length Matrix (RLM), 11 Gray Level Size Zone Matrix (GLSZM) and 33 Intensity-based features (IBF). The treatment outcome was divided based on the last follow up status into three classes: No Evidence of Disease (NED), Alive with Disease (AWD) and Dead of Disease (DOD). The ability for the radiomics features to differentiate between the 3 treatments outcome categories were assessed by One-Way ANOVA test with p-value < 0.05 was to be statistically significant. The results from the analysis were compared with the ones obtained previously for standard Uptake Value (SUV). Results: Based on patients last clinical follow-up; 52 showed NED, 17 AWD and 10 DOD. Radiomics Features were able to classify the patients based on their treatment response. A parallel analysis was done for SUV measurements for comparison. Conclusion: Radiomics features were able to differentiate between the three different classes of treatment outcomes. However, most of the features were only able to differentiate between NED and DOD class. Also, The ability or radiomics features to differentiate types of response were more significant than SUV.

  3. SU-E-J-243: Reproducibility of Radiomics Features Through Different Voxel Discretization Levels in F18-FDG PET Images of Cervical Cancer

    SciTech Connect

    Altazi, B; Fernandez, D; Zhang, G; Biagioli, M; Moros, E; Moffitt, H. Lee

    2015-06-15

    Purpose: Site-specific investigations of the role of Radiomics in cancer diagnosis and therapy are needed. We report of the reproducibility of quantitative image features over different discrete voxel levels in PET/CT images of cervical cancer. Methods: Our dataset consisted of the pretreatment PET/CT scans from a cohort of 76 patients diagnosed with cervical cancer, FIGO stage IB-IVA, age range 31–76 years, treated with external beam radiation therapy to a dose range between 45–50.4 Gy (median dose: 45 Gy), concurrent cisplatin chemotherapy and MRI-based Brachytherapy to a dose of 20–30 Gy (median total dose: 28 Gy). Two board certified radiation oncologists delineated Metabolic Tumor volume (MTV) for each patient. Radiomics features were extracted based on 32, 64, 128 and 256 discretization levels (DL). The 64 level was chosen to be the reference DL. Features were calculated based on Co-occurrence (COM), Gray Level Size Zone (GLSZM) and Run-Length (RLM) matrices. Mean Percentage Differences (Δ) of features for discrete levels were determined. Normality distribution of Δ was tested using Kolomogorov - Smirnov test. Bland-Altman test was used to investigate differences between feature values measured on different DL. The mean, standard deviation and upper/lower value limits for each pair of DL were calculated. Interclass Correlation Coefficient (ICC) analysis was performed to examine the reliability of repeated measures within the context of the test re-test format. Results: 3 global and 5 regional features out of 48 features showed distribution not significantly different from a normal one. The reproducible features passed the normality test. Only 5 reproducible results were reliable, ICC range 0.7 – 0.99. Conclusion: Most of the radiomics features tested showed sensitivity to voxel level discretization between (32 – 256). Only 4 GLSZM, 3 COM and 1 RLM showed insensitivity towards mentioned discrete levels.

  4. The Effect of Endogenous Adenosine on Neuronal Activity in Rats: An FDG PET Study

    PubMed Central

    Paul, Soumen; Zhang, Dali; Mzengeza, Shadreck; Ko, Ji Hyun

    2016-01-01

    ABSTRACT 2–18F‐fluorodeoxy‐D‐glucose (FDG) is a glucose analog that is taken up by cells and phosphorylated. The amount of FDG accumulated by cells is a measure of the rate of glycolysis, which reflects cellular activity. As the levels and actions of the neuromodulator adenosine are dynamically regulated by neuronal activity, this study was designed to test whether endogenous adenosine affects tissue accumulation of FDG as assessed by positron emission tomography (PET) or by postmortem analysis of tissue radioactivity. Rats were given an intraperitoneal injection of the adenosine A1 receptor antagonist 8‐cyclopentyl‐1,3‐dipropyl‐xanthine (DPCPX, 3 mg/kg), the adenosine kinase inhibitor ABT‐702 (3 mg/kg), or vehicle 10 minutes prior to an intravenous injection of FDG (15.4 ± 0.7 MBq per rat). Rats were then subjected to a 15 minute static PET scan. Reconstructed images were normalized to FDG PET template for rats and standard uptake values (SUVs) were calculated. To examine the regional effect of active treatment compared to vehicle, statistical parametric mapping analysis was performed. Whole‐brain FDG uptake was not affected by drug treatment. Significant regional hypometabolism was detected, particularly in cerebellum, of DPCPX‐ and ABT‐702 treated rats, relative to vehicle‐treated rats. Thus, endogenous adenosine can affect FDG accumulation although this effect is modest in quiescent rats. PMID:27082948

  5. Radiation Dose from Whole-Body F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: Nationwide Survey in Korea

    PubMed Central

    2016-01-01

    The purpose of this study was to estimate average radiation exposure from 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) examinations and to analyze possible factors affecting the radiation dose. A nation-wide questionnaire survey was conducted involving all institutions that operate PET/CT scanners in Korea. From the response, radiation doses from injected FDG and CT examination were calculated. A total of 105 PET/CT scanners in 73 institutions were included in the analysis (response rate of 62.4%). The average FDG injected activity was 310 ± 77 MBq and 5.11 ± 1.19 MBq/kg. The average effective dose from FDG was estimated to be 5.89 ± 1.46 mSv. The average CT dose index and dose-length product were 4.60 ± 2.47 mGy and 429.2 ± 227.6 mGy∙cm, which corresponded to 6.26 ± 3.06 mSv. The radiation doses from FDG and CT were significantly lower in case of newer scanners than older ones (P < 0.001). Advanced PET technologies such as time-of-flight acquisition and point-spread function recovery were also related to low radiation dose (P < 0.001). In conclusion, the average radiation dose from FDG PET/CT is estimated to be 12.2 mSv. The radiation dose from FDG PET/CT is reduced with more recent scanners equipped with image-enhancing algorithms. PMID:26908992

  6. Preparations for flight research to evaluate actuated forebody strakes on the F-18 high-alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Murri, Daniel G.; Shah, Gautam H.; Dicarlo, Daniel J.

    1994-01-01

    As part of the NASA High-Angle-of-Attack Technology Program (HATP), flight tests are currently being conducted with a multi-axis thrust vectoring system applied to the NASA F-18 High Alpha Research Vehicle (HARV). A follow-on series of flight tests with the NASA F-18 HARV will be focusing on the application of actuated forebody strake controls. These controls are designed to provide increased levels of yaw control at high angles of attack where conventional aerodynamic controls become ineffective. The series of flight tests are collectively referred to as the Actuated Nose Strakes for Enhanced Rolling (ANSER) Flight Experiment. The development of actuated forebody strake controls for the F-18 HARV is discussed and a summary of the ground tests conducted in support of the flight experiment is provided. A summary of the preparations for the flight tests is also provided.

  7. Reciprocal Benefits of Mass-Univariate and Multivariate Modeling in Brain Mapping: Applications to Event-Related Functional MRI, H2 15O-, and FDG-PET

    PubMed Central

    Habeck, Christian G.

    2006-01-01

    In brain mapping studies of sensory, cognitive, and motor operations, specific waveforms of dynamic neural activity are predicted based on theoretical models of human information processing. For example in event-related functional MRI (fMRI), the general linear model (GLM) is employed in mass-univariate analyses to identify the regions whose dynamic activity closely matches the expected waveforms. By comparison multivariate analyses based on PCA or ICA provide greater flexibility in detecting spatiotemporal properties of experimental data that may strongly support alternative neuroscientific explanations. We investigated conjoint multivariate and mass-univariate analyses that combine the capabilities to (1) verify activation of neural machinery we already understand and (2) discover reliable signatures of new neural machinery. We examined combinations of GLM and PCA that recover latent neural signals (waveforms and footprints) with greater accuracy than either method alone. Comparative results are illustrated with analyses of real fMRI data, adding to Monte Carlo simulation support. PMID:23165047

  8. Evaluation of the dependence of the exposure dose on the attenuation correction in brain PET/CT scans using 18F-FDG

    NASA Astrophysics Data System (ADS)

    Choi, Eun-Jin; Jeong, Moon-Taeg; Jang, Seong-Joo; Choi, Nam-Gil; Han, Jae-Bok; Yang, Nam-Hee; Dong, Kyung-Rae; Chung, Woon-Kwan; Lee, Yun-Jong; Ryu, Young-Hwan; Choi, Sung-Hyun; Seong, Kyeong-Jeong

    2014-01-01

    This study examined whether scanning could be performed with minimum dose and minimum exposure to the patient after an attenuation correction. A Hoffman 3D Brain Phantom was used in BIO_40 and D_690 PET/CT scanners, and the CT dose for the equipment was classified as a low dose (minimum dose), medium dose (general dose for scanning) and high dose (dose with use of contrast medium) before obtaining the image at a fixed kilo-voltage-peak (kVp) and milliampere (mA) that were adjusted gradually in 17-20 stages. A PET image was then obtained to perform an attenuation correction based on an attenuation map before analyzing the dose difference. Depending on tube current in the range of 33-190 milliampere-second (mAs) when BIO_40 was used, a significant difference in the effective dose was observed between the minimum and the maximum mAs (p < 0.05). According to a Scheffe post-hoc test, the ratio of the minimum to the maximum of the effective dose was increased by approximately 5.26-fold. Depending on the change in the tube current in the range of 10-200 mA when D_690 was used, a significant difference in the effective dose was observed between the minimum and the maximum of mA (p < 0.05). The Scheffe posthoc test revealed a 20.5-fold difference. In conclusion, because effective exposure dose increases with increasing operating current, it is possible to reduce the exposure limit in a brain scan can be reduced if the CT dose can be minimized for a transmission scan.

  9. Imaging cardiac SCN5A using the novel F-18 radiotracer radiocaine

    PubMed Central

    Hooker, Jacob M.; Strebl, Martin G.; Schroeder, Frederick A.; Wey, Hsiao-Ying; Ambardekar, Amrut V.; McKinsey, Timothy A.; Schoenberger, Matthias

    2017-01-01

    The key function of the heart, a well-orchestrated series of contractions, is controlled by cardiac action potentials. These action potentials are initiated and propagated by a single isoform of voltage gated sodium channels – SCN5A. However, linking changes in SCN5A expression levels to human disease in vivo has not yet been possible. Radiocaine, an F-18 radiotracer for positron emission tomography (PET), is the first SCN5A imaging agent in the heart. Explants from healthy and failing human hearts were compared using radiocaine autoradiography to determine that the failing heart has ~30% lower SCN5A levels - the first evidence of changes in SCN5A expression in humans as a function of disease. Paving the way for translational imaging, radiocaine proved to exhibit high in vivo specific binding to the myocardium of non-human primates. We envision that SCN5A measurements using PET imaging may serve as a novel diagnostic tool to stratify arrhythmia risk and assess for progression of heart failure in patients with a broad spectrum of cardiovascular diseases. PMID:28205593

  10. Performance characteristics of nonaxisymmetric nozzles installed on the F-18 aircraft

    NASA Technical Reports Server (NTRS)

    Capone, F. J.; Gowadia, N. S.; Wooten, W. H.

    1979-01-01

    The Langley Research Center has conducted an experimental program on a model of the F-18 airplane to determine the performance of nonaxisymmetric nozzles relative to the aircraft's baseline axisymmetric nozzle. The performance of a single expansion ramp (ADEN) and two-dimensional convergent-divergent (2-D C-D) nozzle were compared to the baseline axisymmetric nozzles. The effects of vectoring and reversing were also studied. Performance of a modified YF-17 airplane with the ADEN nozzle was also estimated. The results of this investigation indicate that nonaxisymmetric nozzles can be installed on a twin engine fighter airplane with equal or better performance than axisymmetric nozzles. The nonaxisymmetric nozzles also offer potential for innovative and improved aircraft maneuver through thrust vectoring and reversing. The YF-17/ADEN flown as a technology demonstrator would have reduced performance compared to an unmodified YF-17. However, on an equal aircraft weight basis, performance would essentially be equivalent. This study also showed that the YF-17 can serve as a testbed to validate nonaxisymmetric nozzle technology.

  11. Forebody Flow Visualization on the F-18 HARV with Actuated Forebody Strakes

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Murri, Daniel G.

    1998-01-01

    Off-surface smoke flow visualization and extensive pressure measurements were obtained on the forebody of the NASA F-18 High Alpha Research Vehicle equipped with actuated forebody strakes. Test points at alpha = 50 deg. were examined in which only one strake was deflected or in which both strakes were deflected differentially. The forebody pressures were integrated to obtain forebody yawing moments. Results showed that small single strake deflections can cause an undesirable yawing moment reversal. At alpha = 50 deg., this reversal was corrected by deploying both strakes at 20 deg. initially, then differentially from 20 deg. to create a yawing moment. The off-surface flow visualization showed that in the case of the small single strake deflection, the resulting forebody/strake vortex remained close to the surface and caused accelerated flow and increased suction pressures on the deflected side. When both strakes were deflected differentially, two forebody/strake vortices were present. The forebody/strake vortex from the larger deflection would lift from the surface while the other would remain close to the surface. The nearer forebody/strake vortex would cause greater flow acceleration, higher suction pressures and a yawing moment on that side of the forebody. Flow visualization provided a clear description of the strake vortices fluid mechanics.

  12. Forebody Aerodynamics of the F-18 High Alpha Research Vehicle with Actuated Forebody Strakes

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Murri, Daniel G.

    2003-01-01

    Extensive pressure measurements and off-surface flow visualization were obtained on the forebody and strakes of the NASA F-18 High Alpha Research Vehicle (HARV) equipped with actuated forebody strakes. Forebody yawing moments were obtained by integrating the circumferential pressures on the forebody and strakes. Results show that large yawing moments can be generated with forebody strakes. At a 50 -angle-of-attack, deflecting one strake at a time resulted in a forebody yawing moment control reversal for small strake deflection angles. However, deflecting the strakes differentially about a 20 symmetric strake deployment eliminated the control reversal and produced a near linear variation of forebody yawing moment with differential strake deflection. At an angle of attack of 50 and for 0 and 20 symmetric strake deployments, a larger forebody yawing moment was generated by the forward fuselage (between the radome and the apex of the leading-edge extensions) than on the radome where the actuated forebody strakes were located. Cutouts on the flight vehicle strakes that were not on the wind tunnel models are believed to be responsible for deficits in the suction peaks on the flight radome pressure distributions and differences in the forebody yawing moments.

  13. Experience with Ada on the F-18 High Alpha Research Vehicle flight test program

    NASA Technical Reports Server (NTRS)

    Regenie, Victoria A.; Earls, Michael; Le, Jeanette; Thomson, Michael

    1994-01-01

    Considerable experience has been acquired with Ada at the NASA Dryden Flight Research Facility during the on-going High Alpha Technology Program. In this program, an F-18 aircraft has been highly modified by the addition of thrust-vectoring vanes to the airframe. In addition, substantial alteration was made in the original quadruplex flight control system. The result is the High Alpha Research Vehicle. An additional research flight control computer was incorporated in each of the four channels. Software for the research flight control computer was written Ada. To date, six releases of this software have been flown. This paper provides a detailed description of the modifications to the research flight control system. Efficient ground-testing of the software was accomplished by using simulations that used the Ada for portions of their software. These simulations are also described. Modifying and transferring the Ada flight software to the software simulation configuration has allowed evaluation of this language. This paper also discusses such significant issues in using Ada as portability, modifiability, and testability as well as documentation requirements.

  14. Adaptive Flight Control Design with Optimal Control Modification on an F-18 Aircraft Model

    NASA Technical Reports Server (NTRS)

    Burken, John J.; Nguyen, Nhan T.; Griffin, Brian J.

    2010-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to as the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly; however, a large adaptive gain can lead to high-frequency oscillations which can adversely affect the robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient robustness. A damping term (v) is added in the modification to increase damping as needed. Simulations were conducted on a damaged F-18 aircraft (McDonnell Douglas, now The Boeing Company, Chicago, Illinois) with both the standard baseline dynamic inversion controller and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model.

  15. Experience with Ada on the F-18 High Alpha Research Vehicle Flight Test Program

    NASA Technical Reports Server (NTRS)

    Regenie, Victoria A.; Earls, Michael; Le, Jeanette; Thomson, Michael

    1992-01-01

    Considerable experience was acquired with Ada at the NASA Dryden Flight Research Facility during the on-going High Alpha Technology Program. In this program, an F-18 aircraft was highly modified by the addition of thrust-vectoring vanes to the airframe. In addition, substantial alteration was made in the original quadruplex flight control system. The result is the High Alpha Research Vehicle. An additional research flight control computer was incorporated in each of the four channels. Software for the research flight control computer was written in Ada. To date, six releases of this software have been flown. This paper provides a detailed description of the modifications to the research flight control system. Efficient ground-testing of the software was accomplished by using simulations that used the Ada for portions of their software. These simulations are also described. Modifying and transferring the Ada for flight software to the software simulation configuration has allowed evaluation of this language. This paper also discusses such significant issues in using Ada as portability, modifiability, and testability as well as documentation requirements.

  16. Flight-determined engine exhaust characteristics of an F404 engine in an F-18 airplane

    NASA Technical Reports Server (NTRS)

    Ennix, Kimberly A.; Burcham, Frank W., Jr.; Webb, Lannie D.

    1993-01-01

    Personnel at the NASA Langley Research Center (NASA-Langley) and the NASA Dryden Flight Research Facility (NASA-Dryden) recently completed a joint acoustic flight test program. Several types of aircraft with high nozzle pressure ratio engines were flown to satisfy a twofold objective. First, assessments were made of subsonic climb-to-cruise noise from flights conducted at varying altitudes in a Mach 0.30 to 0.90 range. Second, using data from flights conducted at constant altitude in a Mach 0.30 to 0.95 range, engineers obtained a high quality noise database. This database was desired to validate the Aircraft Noise Prediction Program and other system noise prediction codes. NASA-Dryden personnel analyzed the engine data from several aircraft that were flown in the test program to determine the exhaust characteristics. The analysis of the exhaust characteristics from the F-18 aircraft are reported. An overview of the flight test planning, instrumentation, test procedures, data analysis, engine modeling codes, and results are presented.

  17. F-16XL and F-18 High Speed Acoustic Flight Test Databases

    NASA Technical Reports Server (NTRS)

    Kelly, J. J.; Wilson, M. R.; Rawls, J., Jr.; Norum, T. D.; Golub, R. A.

    1999-01-01

    This report presents the recorded acoustic data and the computed narrow-band and 1/3-octave band spectra produced by F-18 and F-16XL aircraft in subsonic flight over an acoustic array. Both broadband-shock noise and turbulent mixing noise are observed in the spectra. Radar and c-band tracking systems provided the aircraft position which enabled directivity and smear angles from the aircraft to each microphone to be computed. These angles are based on source emission time and thus give some idea about the directivity of the radiated sound field due to jet noise. A follow-on static test was also conducted where acoustic and engine data were obtained. The acoustic data described in the report has application to community noise analysis, noise source characterization and validation of prediction models. A detailed description of the signal processing procedures is provided. Follow-on static tests of each aircraft were also conducted for which engine data and far-field acoustic data are presented.

  18. Effect of Actuated Forebody Strakes on the Forebody Aerodynamics of the NASA F-18 HARV

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Murri, Daniel G.; Lanser, Wendy R.

    1996-01-01

    Extensive pressure measurements and off-surface flow visualization were obtained on the forebody and strakes of the NASA F-18 High Alpha Research Vehicle (HARV) equipped with actuated forebody strakes. Forebody yawing moments were obtained by integrating the circumferential pressures on the forebody and strakes. Results show that large yawing moments can be generated with forebody strakes. At angles of attack greater than 40 deg., deflecting one strake at a time resulted in a forebody yawing moment control reversal for small strake deflection angles. At alpha = 40 deg. and 50 deg., deflecting the strakes differentially about a 20 deg. symmetric strake deployment eliminated the control reversal and produced a near linear variation of forebody yawing moment with differential strake deflection. At alpha = 50 deg. and for 0 deg. and 20 deg. symmetric strake deployments, a larger forebody yawing moment was generated by the forward fuselage (between the radome and the apex of the leading-edge extensions), than on the radome where the actuated forebody strakes were located. Cutouts on the flight vehicle strakes that were not on the wind tunnel models are believed to be responsible for deficits in the suction peaks on the flight radome pressure distributions and differences in the forebody yawing moments.

  19. Forebody Aerodynamics of the F-18 High Alpha Research Vehicle with Actuated Forebody Strakes

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Murri, Daniel G.

    2001-01-01

    Extensive pressure measurements and off-surface flow visualization were obtained on the forebody and strakes of the NASA F-18 High Alpha Research Vehicle (HARV) equipped with actuated forebody strakes. Forebody yawing moments were obtained by integrating the circumferential pressures on the forebody and strakes. Results show that large yawing moments can be generated with forebody strakes. At a 50 deg-angle-of-attack, deflecting one strake at a time resulted in a forebody yawing moment control reversal for small strake deflection angles. However, deflecting the strakes differentially about a 20 deg symmetric strake deployment eliminated the control reversal and produced a near linear variation of forebody yawing moment with differential strake deflection. At an angle of attack of 50 deg and for 0 deg and 20 deg symmetric strake deployments, a larger forebody yawing moment was generated by the forward fuselage (between the radome and the apex of the leading-edge extensions) than on the radome where the actuated forebody strakes were located. Cutouts on the flight vehicle strakes that were not on the wind tunnel models are believed to be responsible for deficits in the suction peaks on the flight radome pressure distributions and differences in the forebody yawing moments.

  20. [18F FDG PET-Applications in Oncology].

    PubMed

    Răileanu, Irena; Rusu, V; Stefănescu, Cipriana; Cinotti, L; Hountis, D

    2002-01-01

    In the first part our intention was, essentially, to present the particularities of glucose tumoral cells metabolism, PET components, the synthesis of 18F FDG and the detection of unknown cancers. This second part makes reference about mainly types of tumors who benefit by FDG-PET indications. Clinical PET has a rapid growth because of its use in cancer diagnosis and management. According with published studies all over the world, the sensibility and specificity of FDG-PET, noninvasive method, is higher than that of the conventional methods like CT, IRM, ultrasonography. PET is en excellent detection method of most of common cancer types and depends not on the histological neoplasm type; the more aggressive is the tumor, more it will uptake the radiotracer. The cost is significant, so the indications must be very precise: evaluating the malignity of solitary pulmonary nodules, evaluating the recurrences of melanoma, colon cancer diagnosis, differentiation between recurrent brain tumor and radiation injury, differential diagnosis of the benign lymph and malign lymph nodes, staging of Hodgkin's and non-Hodgkin's lymphoma, evaluation the response to therapy. Because the PET images are difficult to interpret, appears the necessity of correlation with anatomic images: this was the fusion images beginnings (the PET and CT images combination); now the physiologic information has precise anatomic localization. The growing of this method is very probably, both using 18F FDG -thanks to its highly favorable physical characteristics- and other new radiopharmaceuticals. The clinical cases that illustrate the applications are investigated at CERMEP, Lyon, France.

  1. Screening for occult malignancy with FDG-PET/CT in patients with unprovoked venous thromboembolism.

    PubMed

    Alfonso, Ana; Redondo, Margarita; Rubio, Tomás; Del Olmo, Beatriz; Rodríguez-Wilhelmi, Pablo; García-Velloso, María J; Richter, José A; Páramo, José A; Lecumberri, Ramón

    2013-11-01

    Extensive screening strategies to detect occult cancer in patients with unprovoked venous thromboembolism (VTE) are complex and no benefit in terms of survival has been reported. FDG-PET/CT (2-[F-18] fluoro-2-deoxy-D-glucose positron emission tomography combined with computed tomography), a noninvasive technique for the diagnosis and staging of malignancies, could be useful in this setting. Consecutive patients ≥ 50 years with a first unprovoked VTE episode were prospectively included. Screening with FDG-PET/CT was performed 3-4 weeks after the index event. If positive, appropriate diagnostic work-up was programmed. Clinical follow-up continued for 2 years. Blood samples were collected to assess coagulation biomarkers. FDG-PET/CT was negative in 68/99 patients (68.7%), while suspicious FDG uptake was detected in 31/99 patients (31.3%). Additional diagnostic work-up confirmed a malignancy in 7/31 patients (22.6%), with six of them at early stage. During follow-up, two patients with negative FDG-PET/CT were diagnosed with cancer. Sensitivity (S), positive (PPV) and negative predictive values (NPV) of FDG-PET/CT as single tool for the detection of occult malignancy were 77.8% (95% CI: 0.51-1), 22.6% (95% CI: 0.08-0.37) and 97.1% (95% CI: 0.93-1), respectively. Median tissue factor (TF) activity in patients with occult cancer was 5.38 pM vs. 2.40 pM in those without cancer (p = 0.03). Limitation of FDG-PET/CT screening to patients with TF activity > 2.8 pM would improve the PPV to 37.5% and reduce the costs of a single cancer diagnosis from 20,711€ to 11,670€. FDG-PET/CT is feasible for the screening of occult cancer in patients with unprovoked VTE, showing high S and NPV. The addition of TF activity determination may be useful for patient selection.

  2. Flight-Determined, Subsonic, Lateral-Directional Stability and Control Derivatives of the Thrust-Vectoring F-18 High Angle of Attack Research Vehicle (HARV), and Comparisons to the Basic F-18 and Predicted Derivatives

    NASA Technical Reports Server (NTRS)

    Iliff, Kenneth W.; Wang, Kon-Sheng Charles

    1999-01-01

    The subsonic, lateral-directional, stability and control derivatives of the thrust-vectoring F-1 8 High Angle of Attack Research Vehicle (HARV) are extracted from flight data using a maximum likelihood parameter identification technique. State noise is accounted for in the identification formulation and is used to model the uncommanded forcing functions caused by unsteady aerodynamics. Preprogrammed maneuvers provided independent control surface inputs, eliminating problems of identifiability related to correlations between the aircraft controls and states. The HARV derivatives are plotted as functions of angles of attack between 10deg and 70deg and compared to flight estimates from the basic F-18 aircraft and to predictions from ground and wind tunnel tests. Unlike maneuvers of the basic F-18 aircraft, the HARV maneuvers were very precise and repeatable, resulting in tightly clustered estimates with small uncertainty levels. Significant differences were found between flight and prediction; however, some of these differences may be attributed to differences in the range of sideslip or input amplitude over which a given derivative was evaluated, and to differences between the HARV external configuration and that of the basic F-18 aircraft, upon which most of the prediction was based. Some HARV derivative fairings have been adjusted using basic F-18 derivatives (with low uncertainties) to help account for differences in variable ranges and the lack of HARV maneuvers at certain angles of attack.

  3. Genome Sequences and Phylogenetic Analysis of K88- and F18-Positive Porcine Enterotoxigenic Escherichia coli

    PubMed Central

    Shepard, Sara M.; Danzeisen, Jessica L.; Isaacson, Richard E.; Seemann, Torsten; Achtman, Mark

    2012-01-01

    Porcine enterotoxigenic Escherichia coli (ETEC) continues to result in major morbidity and mortality in the swine industry via postweaning diarrhea. The key virulence factors of ETEC strains, their serotypes, and their fimbrial components have been well studied. However, most studies to date have focused on plasmid-encoded traits related to colonization and toxin production, and the chromosomal backgrounds of these strains have been largely understudied. Here, we generated the genomic sequences of K88-positive and F18-positive porcine ETEC strains and examined the phylogenetic distribution of clinical porcine ETEC strains and their plasmid-associated genetic content. The genomes of porcine ETEC strains UMNK88 and UMNF18 were both found to contain remarkable plasmid complements containing known virulence factors, potential novel virulence factors, and antimicrobial resistance-associated elements. The chromosomes of these strains also possessed several unique genomic islands containing hypothetical genes with similarity to classical virulence factors, although phage-associated genomic islands dominated the accessory genomes of these strains. Phylogenetic analysis of 78 clinical isolates associated with neonatal and porcine diarrhea revealed that a limited subset of porcine ETEC lineages exist that generally contain common toxin and fimbrial profiles, with many of the isolates belonging to the ST10, ST23, and ST169 multilocus sequencing types. These lineages were generally distinct from existing human ETEC database isolates. Overall, most porcine ETEC strains appear to have emerged from a limited subset of E. coli lineages that either have an increased propensity to carry plasmid-encoded virulence factors or have the appropriate ETEC core genome required for virulence. PMID:22081385

  4. 1/48-scale model of an F-18 aircraft in Flow Visualization Facility (FVF)

    NASA Technical Reports Server (NTRS)

    1985-01-01

    This image shows a plastic 1/48-scale model of an F-18 aircraft inside the 'Water Tunnel' more formally known as the NASA Dryden Flow Visualization Facility. Water is pumped through the tunnel in the direction of normal airflow over the aircraft; then, colored dyes are pumped through tubes with needle valves. The dyes flow back along the airframe and over the airfoils highlighting their aerodynamic characteristics. The aircraft can also be moved through its pitch axis to observe airflow disruptions while simulating actual flight at high angles of attack. The Water Tunnel at NASA's Dryden Flight Research Center, Edwards, CA, became operational in 1983 when Dryden was a Flight Research Facility under the management of the Ames Research Center in Mountain View, CA. As a medium for visualizing fluid flow, water has played a significant role. Its use dates back to Leonardo da Vinci (1452-1519), the Renaissance Italian engineer, architect, painter, and sculptor. In more recent times, water tunnels have assisted the study of complex flows and flow-field interactions on aircraft shapes that generate strong vortex flows. Flow visualization in water tunnels assists in determining the strength of vortices, their location, and possible methods of controlling them. The design of the Dryden Water Tunnel imitated that of the Northrop Corporation's tunnel in Hawthorne, CA. Called the Flow Visualization Facility, the Dryden tunnel was built to assist researchers in understanding the aerodynamics of aircraft configured in such a way that they create strong vortex flows, particularly at high angles of attack. The tunnel provides results that compare well with data from aircraft in actual flight in another fluid-air. Other uses of the tunnel have included study of how such flight hardware as antennas, probes, pylons, parachutes, and experimental fixtures affect airflow. The facility has also been helpful in finding the best locations for emitting smoke from flight vehicles for flow

  5. 1/48-scale model of an F-18 aircraft in Flow Visualization Facility (FVF)

    NASA Technical Reports Server (NTRS)

    1980-01-01

    This short movie clip shows a plastic 1/48-scale model of an F-18 aircraft inside the 'Water Tunnel' more formally known as the NASA Dryden Flow Visualization Facility. Water is pumped through the tunnel in the direction of normal airflow over the aircraft; then, colored dyes are pumped through tubes with needle valves. The dyes flow back along the airframe and over the airfoils highlighting their aerodynamic characteristics. The aircraft can also be moved through its pitch axis to observe airflow disruptions while simulating actual flight at high angles of attack. The Water Tunnel at NASA's Dryden Flight Research Center, Edwards, CA, became operational in 1983 when Dryden was a Flight Research Facility under the management of the Ames Research Center in Mountain View, CA. As a medium for visualizing fluid flow, water has played a significant role. Its use dates back to Leonardo da Vinci (1452-1519), the Renaissance Italian engineer, architect, painter, and sculptor. In more recent times, water tunnels have assisted the study of complex flows and flow-field interactions on aircraft shapes that generate strong vortex flows. Flow visualization in water tunnels assists in determining the strength of vortices, their location, and possible methods of controlling them. The design of the Dryden Water Tunnel imitated that of the Northrop Corporation's tunnel in Hawthorne, CA. Called the Flow Visualization Facility, the Dryden tunnel was built to assist researchers in understanding the aerodynamics of aircraft configured in such a way that they create strong vortex flows, particularly at high angles of attack. The tunnel provides results that compare well with data from aircraft in actual flight in another fluid-air. Other uses of the tunnel have included study of how such flight hardware as antennas, probes, pylons, parachutes, and experimental fixtures affect airflow. The facility has also been helpful in finding the best locations for emitting smoke from flight vehicles

  6. Oral administration of citrus pulp reduces gastrointestinal recovery of orally dosed Escherichia coli F18 in weaned pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of citrus pulp (CTP) on the immune and cortisol responses to E. coli F18 inoculation and subsequent E. coli recovery were evaluated in newly weaned pigs (23.3 + 1.8 d of age). Barrows were assigned to 1 of 2 treatment groups; with (CTP; n = 15) and without (Control; n = 15) the in-feed i...

  7. Oral administration of citrus pulp reduces gasrointestinal recovery of orally dosed Escherichia coli F18 in weaned pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of citrus pulp (CTP), on the immune and cortisol responses to E. coli F18 inoculation and subsequent E. coli recovery were evaluated in newly weaned pigs (23.3 + 1.8 d of age). Barrows were assigned to 1 of 2 treatment groups; with (CTP; n = 15) and without (Control; n = 15) the in-feed ...

  8. F-18 HARV yaw rate expansion flight #125 with Inverted Recovery

    NASA Technical Reports Server (NTRS)

    1991-01-01

    NASA's Dryden Flight Research Center, Edwards, CA, used an F-18 Hornet fighter aircraft as its High Angle-of-Attack (Alpha) Research Vehicle (HARV) in a three-phased flight research program lasting from April 1987 until September 1996. The aircraft completed 385 research flights and demonstrated stabilized flight at angles of attack between 65 and 70 degrees using thrust vectoring vanes, a research flight control system, and (eventually) forebody strakes (hinged structures on the forward side of the fuselage to provide control by interacting with vortices, generated at high angles of attack, to create side forces). This combination of technologies provided carefree handling of a fighter aircraft in a part of the flight regime that was otherwise very dangerous. Flight research with the HARV increased our understanding of flight at high angles of attack (angle of the wings with respect to the direction in which the aircraft was heading), enabling designers of U.S. fighter aircraft to design airplanes that will fly safely in portions of the flight envelope that pilots previously had to avoid. Flight 125 with the HARV involved yaw rate expansion up to 50 degrees per second (moving the nose to the left or right at that rate). NASA research pilot Ed Schneider was the pilot, and the purpose of the flight was to look at the spin characteristics of the HARV. The sequence in this particular video clip includes the first and second maneuvers in the flight. On the first maneuver, the pilot attempted to achieve a yaw rate of 40 degrees per second and actually went to 47 degrees. The spin was oscillatory in pitch (up and down) and roll (rotating around the longitudinal axis). Recovery was normal. On the second maneuver of the flight in which Schneider tried to achieve a yaw rate of 40 degrees per second, the aircraft overshot to 54 degrees per second during an oscillatory spin. In the course of the recovery, the aircraft rolled after a large sideslip buildup. Moderate aft stick

  9. [Usefulness of SPECT images in helping radiologists understand brain diseases].

    PubMed

    Hayashida, K

    2001-04-01

    Nuclear brain imaging is able to show functional abnormalities of lesions that are not detectable by CT and MR images. The diagnostic keys of nuclear-imaging in terms of clinical usefulness are its early detection of lesions and determination of the efficacy of drug and surgical therapies. In dementic patients, F-18 FDG brain images can be diagnosed as Alzheimer's disease 12 months earlier than is possible on CT and MRI images, and can provide information for effective drug therapy. O-15 water CBF images can predict the effect of Nicholin by assessing transient increases in cerebral blood flow (CBF), thereby facilitating improvement in higher brain functions such as orientation. In stroke patients, brain SPECT images with Tc-99m HMPAO can predict fatal cerebral hemorrhage caused by anti-thrombic therapy by showing the decrease in count ratio (count ratio of infarcted to contralateral area of < 0.34) in the acute phase and identifying disruption of the blood brain barrier by showing hyperfixation in the subacute phase. Brain SPECT with I-123 IMP can also identify "misery" perfused areas resulting from reduced CBF and decreased vasoreactivity in the chronic phase. This criterion is utilized for patient selection for extracranial/intracranial bypass surgery, because patients with areas of poor perfusion might be indicated for such surgery. Since nuclear medicine images can accurately select candidates for drug or surgical therapies, they will be beneficial in reducing Medicare costs as well as in enhancing patients' quality of life as a result of the successful treatment. With the advancement of technology, nuclear medicine units that can simultaneously obtain CT images and can combine functional with anatomical images will provide more useful information for the diagnosis of brain disease.

  10. Wilson's disease studied with FDG and positron emission tomography

    SciTech Connect

    Hawkins, R.A.; Mazziotta, J.C.; Phelps, M.E.

    1987-11-01

    Four patients with Wilson's disease and eight normal controls were studied with 2-deoxy-2-(/sup 18/F)fluoro-D-glucose (FDG) and positron emission tomography (PET). The patients had diffusely reduced glucose metabolism in all brain regions evaluated compared with controls, with the exception of the thalamus. The ratio of the cerebral metabolic rate for glucose in the lenticular nuclei to hemispheres declined from 1.23 (+/- 0.14 SD) in controls to 1.03 (+/- 0.06) (p less than 0.025) in Wilson's disease patients. Compared with Huntington's disease, the PET FDG results in Wilson's disease indicate relatively less focal involvement of the caudate nucleus, more severe focal changes in the lenticular nuclei, and more significant global changes in glucose metabolism.

  11. FDG-PET scan shows increased cerebral blood flow in rat after sublingual glycine application

    NASA Astrophysics Data System (ADS)

    Blagosklonov, Oleg; Podoprigora, Guennady I.; Davani, Siamak; Nartsissov, Yaroslav R.; Comas, Laurent; Boulahdour, Hatem; Cardot, Jean-Claude

    2007-02-01

    Positron emission tomography (PET) with [18F]-2-fluoro-deoxy-D-glucose (FDG) is being increasingly used in research. Isotope studies may be of help in an assessment of vasoactive potential of newly developed therapeutic preparations, including natural metabolites, like glycine. As a medicine, glycine was recently shown to have a positive therapeutic effect in the treatment of patients with neurological disorders based on vascular disturbances. By previous direct biomicroscopic investigations of pial microvessels in laboratory rats, an expressed vasodilatory effect of topically applied glycine was proved. The aim of this study was to evaluate the influence of glycine on the rat cerebral blood flow (CBF) using FDG-PET scan. A baseline study was started immediately after intravenous injection of 19 MBq of FDG in anesthetized rat. The PET images were acquired twice, one by one during 20 min. Two hours later, after sublingual application of glycine and the second FDG injection, the pair of PET scan was performed during 20 min as well. Finally, 4 days after the first studies, we repeated the PET scans in the same conditions after sublingual application of glycine. The quantitative analysis of FDG volume concentration (Bq/ml) in the rat brain demonstrated that in both studies after glycine administration, the FDG uptake increased at least 1.5 times in comparison with the baseline data. Moreover, the peak of the concentration was coming in more rapidly. These results confirm the enhancing effect of glycine on the rat CBF possibly because of its vasodilatory effect on brain microvessels. Therefore, FDG-PET technique contributes to better understanding of glycine pharmacokinetics.

  12. Flutter Clearance of the F-18 High-angle-of-attack Research Vehicle with Experimental Wingtip Instrumentation Pods

    NASA Technical Reports Server (NTRS)

    Freudinger, Lawrence C.

    1989-01-01

    An F-18 aircraft was modified with wingtip instrumentation pods for use in NASA's high-angle-of-attack research program. Ground vibration and flight flutter testing were performed to clear an acceptable flight envelope for the aircraft. Flight test utilized atmospheric turbulence for structural excitation; the aircraft displayed no adverse aeroelastic trends within the envelope tested. The data presented in this report include mode shapes from the ground vibration and estimates of frequency and damping as a function of Mach number.

  13. Surface flow visualization of separated flows on the forebody of an F-18 aircraft and wind-tunnel model

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Richwine, David M.; Banks, Daniel W.

    1988-01-01

    A method of in-flight surface flow visualization similar to wind-tunnel-model oil flows is described for cases where photo-chase planes or onboard photography are not practical. This method, used on an F-18 aircraft in flight at high angles of attack, clearly showed surface flow streamlines in the fuselage forebody. Vortex separation and reattachment lines were identified with this method and documented using postflight photography. Surface flow angles measured at the 90 and 270 degrees meridians show excellent agreement with the wind tunnel data for a pointed tangent ogive with an aspect ratio of 3.5. The separation and reattachment line locations were qualitatively similar to the F-18 wind-tunnel-model oil flows but neither the laminar separation bubble nor the boundary-layer transition on the wind tunnel model were evident in the flight surface flows. The separation and reattachment line locations were in fair agreement with the wind tunnel data for the 3.5 ogive. The elliptical forebody shape of the F-18 caused the primary separation lines to move toward the leeward meridian. Little effect of angle of attack on the separation locations was noted for the range reported.

  14. KEY COMPARISON: Comparisons CCRI(II)-K3.F-18 and APMP.RI(II)-K3.F-18 of activity measurements of the radionuclide 18F and links to the key comparison reference value of the BIPM.RI(II)-K1.F-18 comparison

    NASA Astrophysics Data System (ADS)

    Ratel, G.; Michotte, C.; Woods, M. J.

    2005-01-01

    In 2003, the CCRI(II) decided that an indirect comparison of 18F measurements piloted by the National Physical Laboratory (NPL), UK in 2001 was sufficiently well constructed that it could be converted into a CCRI(II) comparison, with comparison identifier CCRI(II)-K3.F-18. At the same time, the pilot laboratory made a bilateral comparison with the institute in Chinese Taipei, comparison identifier APMP.RI(II)-K3.F-18. The results of the comparisons have been reported and the key comparison working group (KCWG) of the CCRI(II) has approved the mechanism to link all the results to the key comparison reference value (KCRV) of 18F. The KCRV has been determined through the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.F-18. These comparisons have enabled a further four results to be added to the matrix of degrees of equivalence for 18F activity measurements. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by Section II of the Consultative Committee for Ionizing Radiation (CCRI(II)), according to the provisions of the Mutual Recognition Arrangement (MRA).

  15. SR-71B - in Flight with F-18 Chase Aircraft - View from Air Force Tanker

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA 831, an SR-71B operated by the Dryden Flight Research Center, Edwards, California, cruises over the Mojave Desert with an F/A-18 Hornet flying safety chase. They were photographed on a 1996 mission from an Air Force refueling tanker The F/A-18 Hornet is used primarily as a safety chase and support aircraft at Dryden. As support aircraft, the F-18s are used for safety chase, pilot proficiency and aerial photography. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used

  16. SR-71B - in Flight with F-18 Chase Aircraft - View from Air Force Tanker

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA 831, an SR-71B operated by the Dryden Flight Research Center, Edwards, California, cruises over the Mojave Desert with an F/A-18 Hornet flying safety chase. They were photographed on a 1996 mission from an Air Force refueling tanker The F/A-18 Hornet is used primarily as a safety chase and support aircraft at Dryden. As support aircraft, the F-18s are used for safety chase, pilot proficiency and aerial photography. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used

  17. Designations F18ab and F18ac for the related fimbrial types F107, 2134P and 8813 of Escherichia coli isolated from porcine postweaning diarrhoea and from oedema disease.

    PubMed

    Rippinger, P; Bertschinger, H U; Imberechts, H; Nagy, B; Sorg, I; Stamm, M; Wild, P; Wittig, W

    1995-08-01

    The relatedness of the fimbriae produced by eight E. coli strains including type strains with F107 fimbriae, 2134P pili and colonization factor 8813 (preliminary F18), was examined. These strains had been isolated principally from pigs which were affected with postweaning diarrhoea or with oedema disease. The fimbriae were analyzed by means of electron microscopy, slide agglutination, immunofluorescence, immunogold labelling, immuno-diffusion, immunoelectrophoresis and western blot, molecular genetic techniques, and in vitro adhesion. The fimbriae of all the strains were long flexible filaments with a diameter not larger than 4.6 nm showing a zig-zag pattern. Results obtained by the serological techniques confirmed that the fimbriae possessed a common antigenic determinant designated 'a' in addition to a variant-specific determinant designated 'b' or 'c'. Immunoelectron microscopy demonstrated that the determinants 'a' and 'b' or 'a' and 'c' were localized along the same fimbrium. In immunoelectrophoresis, fimbrial extracts of selected strains yielded a single precipitation line towards the cathode. One single major subunit of approximately 15 kDa was recognised in western blots by antisera against the common antigenic determinant and the variant specific determinants. All strains possessed sequences related to gene fedA, coding for the major subunit of fimbriae F107. Two types of fedA-related subunit genes were differentiated, corresponding to the 'ab' and 'ac' types of fimbriae as defined by serological methods. The results demonstrated that F107 fimbriae, 2134P pili and colonization factor 8813 are related, and that two serological variants can be distinguished. We propose designations F18ab (for F107), and F18ac (for 2134P and 8813) in analogy to the nomenclature of F4 fimbriae.

  18. 18F-FDG PET/CT diagnosis of vagus nerve neurolymphomatosis.

    PubMed

    Tsang, Hailey Hoi Ching; Lee, Elaine Yuen Phin; Anthony, Marina-Portia; Khong, Pek-Lan

    2012-09-01

    A 62-year-old woman was in remission from previously treated stage IV diffuse large B-cell lymphoma with cranial involvement. She presented with new-onset hoarseness of voice and choking; MRI of the brain showed disease recurrence in the left cavernous sinus. She was subsequently referred for F-FDG PET/CT with contrast for further evaluation of lymphomatous recurrence. F-FDG PET/CT not only revealed hypermetabolic activity in the left cavernous sinus correlating to the MRI findings but also showed an interesting manifestation explaining the patient's hoarseness of voice, being neurolymphomatosis along the left vagus nerve.

  19. Sphenoid wing meningioma behavior on 11C-PiB and 18F-FDG PET.

    PubMed

    Chaves, Hernan; Bergamo, Yanina; Paz, Santiago; Sanchez, Flavio; Vazquez, Silvia

    2015-01-01

    Two patients with mild cognitive impairment underwent C-PiB and F-FDG brain PET. Both patients had previously gone through a contrast-enhanced MRI scan that revealed extra-axial tumors next to the sphenoid wing, suggestive of meningiomas. C-PiB PET images showed a highly increased uptake by the extra-axial masses. These 2 cases represent 1.2% of our C-PiB population (n = 163). No meningioma was found with negative C-PiB uptake. The F-FDG concentration was not increased within the lesions. C-PiB could be used as a meningioma marker.

  20. CD14 in the TLRs signaling pathway is associated with the resistance to E. coli F18 in Chinese domestic weaned piglets

    PubMed Central

    Wu, Zhengchang; Liu, Ying; Dong, Wenhua; Zhu, Guo-qiang; Wu, Shenglong; Bao, Wenbin

    2016-01-01

    Escherichia coli F18 (E. coli F18) is mainly responsible for post-weaning diarrhea (PWD) in piglets. The genetic basis and regulatory mechanism of E. coli F18 resistance in Chinese domestic weaned piglets remain unclear. Meishan piglets were used as model animals to test their susceptibility to E. coli F18. By performing a comparative transcriptome study on duodenum tissues of sensitive and resistant pigs, we identified 198 differentially expressed genes (DEGs; 125 upregulated and 73 downregulated) in the resistant pigs. DEGs were predominately involved in immune system pathways, including the Toll-like receptor (TLR) signaling pathway. qPCR and western blot showed CD14, IFN-α, TLR4 and IL-1β, etc. in the TLR signaling pathway had significantly higher expression levels in lipopolysaccharide (LPS)-induced small intestinal epithelial cell lines (IPEC-J2) than those in normal IPEC-J2 cells. Immunohistochemical analysis showed the increased expression of CD14 gene in the E. coli F18-resistant individuals. After CD14 knockdown, the levels of cytokines IL-6 and IL-12 were significantly reduced in IPEC-J2 cell supernatants. The adhesion ability of F18ab strain with IPEC-J2 cells was significantly increased (p < 0.01). This study revealed the TLR signaling pathway, and especially CD14, probably plays an important role in resistance to E. coli F18 infection in Chinese domestic piglets. PMID:27098998

  1. Free-to-roll tests of X-31 and F-18 subscale models with correlation to flight test results

    NASA Technical Reports Server (NTRS)

    Williams, David L., II; Nelson, Robert C.; Fisher, David F.

    1994-01-01

    This presentation will concentrate on a series of low-speed wind tunnel tests conducted on a 2.5 percent subscale F-18 model and a 2 percent subscale X-31 model. The model's control surfaces were unaugmented; and for the most part, were deflected at a constant angle throughout the tests. The tests consisted mostly of free-to-roll experiments conducted with the use of an air-bearing, surface pressure measurements, off-surface flow visualization, and force-balance tests. Where possible the results of the subscale tests have been compared to flight test data, or to other wind tunnel data taken at higher Reynolds numbers.

  2. Parameter Identification Flight Test Maneuvers for Closed Loop Modeling of the F-18 High Alpha Research Vehicle (HARV)

    NASA Technical Reports Server (NTRS)

    Batterson, James G. (Technical Monitor); Morelli, E. A.

    1996-01-01

    Flight test maneuvers are specified for the F-18 High Alpha Research Vehicle (HARV). The maneuvers were designed for closed loop parameter identification purposes, specifically for longitudinal and lateral linear model parameter estimation at 5,20,30,45, and 60 degrees angle of attack, using the Actuated Nose Strakes for Enhanced Rolling (ANSER) control law in Thrust Vectoring (TV) mode. Each maneuver is to be realized by applying square wave inputs to specific pilot station controls using the On-Board Excitation System (OBES). Maneuver descriptions and complete specifications of the time / amplitude points defining each input are included, along with plots of the input time histories.

  3. Piloted Parameter Identification Flight Test Maneuvers for Closed Loop Modeling of the F-18 High Alpha Research Vehicle (HARV)

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    1996-01-01

    Flight test maneuvers are specified for the F-18 High Alpha Research Vehicle (HARV). The maneuvers were designed for closed loop parameter identification purposes, specifically for longitudinal and lateral linear model parameter estimation at 5, 20, 30, 45, and 60 degrees angle of attack, using the NASA 1A control law. Each maneuver is to be realized by the pilot applying square wave inputs to specific pilot station controls. Maneuver descriptions and complete specifications of the time/amplitude points defining each input are included, along with plots of the input time histories.

  4. Role of F18 fluorodeoxyglucose positron-emission tomography/computed tomography in the management of Askin's tumor.

    PubMed

    Santhosh, Sampath; Kashyap, Raghava; Bhattacharya, Anish; Kumar Jindal, Surinder; Rai Mittal, Bhagwant

    2013-07-01

    A primitive neuroectodermal tumor (PNET) of the thoraco-abdominal region is one of a group of small round cell tumors usually found in children and young adults, originally described by Askin et al. Most cases arise in the soft-tissues of the thorax, but may rarely occur within the lung with the symptoms of chest wall pain, pleural effusion and dyspnea. The authors present two cases demonstrating the utility of F18 fluorodeoxyglucose positron-emission tomography/computed tomography in the staging and prognosis of PNET of the chest wall.

  5. Central Pontine Myelinolysis and Localized Fluorodeoxyglucose Uptake Seen on 18F-FDG PET/CT

    PubMed Central

    Rønne, Frederik; Tfelt-Hansen, Peer Carsten; Rørdam, Lene

    2017-01-01

    Case report describing the finding of central pontine myelinolysis (CPM) using combined fluorine-18 ( 18F)-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). The patient was a known alcoholic who, during admission was under treatment for hyponatremia, showed a significant decline in both motor and cognitive function. Combined 18F-FDG PET/CT showed localized FDG uptake in the pons, consistent with the finding of CPM observed on magnetic resonance imaging (MRI). CPM is a demyelinating lesion of the pons, resulting in several neurological symptoms. The exact cause of CPM is not clear, but a strong relations between loss of myelin and osmotic stress exists, especially during rapid correction of hyponatremia. The osmotic stress is thought to induce disruption of the blood-brain barrier, allowing access for inflammatory mediators in extravascular brain tissue, which most likely attracts glial cells of the brain, attracts macrophages and activates astocytes. We suggest that metabolism in these activated cells could be responsible for the localized FDG uptake during active CPM. PMID:28217021

  6. Calcified peritoneal metastasis identified on 18F-fluoride positron emission tomography/computed tomography: Importance of extraosseous uptake of F-18 fluoride.

    PubMed

    Verma, Priyanka; Chandra, Piyush; Agrawal, Archi; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2016-01-01

    F-18 NaF positron emission tomography/computed tomography (PET/CT) is used for the evaluation of malignant and nonmalignant osseous disease. Extraosseous uptake of 18 fluoride-NaF has been observed in the arterial vasculature, gastrointestinal tract, and genitourinary tract. We describe a case of a woman with carcinoma of unknown primary in whom F-18 NaF PET/CT showed tracer uptake in the calcified peritoneal metastasis. Extraosseous findings on F-18 NaF PET/CT, though rare, may be visualized and may result in important management changes.

  7. Optimal feature selection for automated classification of FDG-PET in patients with suspected dementia

    NASA Astrophysics Data System (ADS)

    Serag, Ahmed; Wenzel, Fabian; Thiele, Frank; Buchert, Ralph; Young, Stewart

    2009-02-01

    FDG-PET is increasingly used for the evaluation of dementia patients, as major neurodegenerative disorders, such as Alzheimer's disease (AD), Lewy body dementia (LBD), and Frontotemporal dementia (FTD), have been shown to induce specific patterns of regional hypo-metabolism. However, the interpretation of FDG-PET images of patients with suspected dementia is not straightforward, since patients are imaged at different stages of progression of neurodegenerative disease, and the indications of reduced metabolism due to neurodegenerative disease appear slowly over time. Furthermore, different diseases can cause rather similar patterns of hypo-metabolism. Therefore, classification of FDG-PET images of patients with suspected dementia may lead to misdiagnosis. This work aims to find an optimal subset of features for automated classification, in order to improve classification accuracy of FDG-PET images in patients with suspected dementia. A novel feature selection method is proposed, and performance is compared to existing methods. The proposed approach adopts a combination of balanced class distributions and feature selection methods. This is demonstrated to provide high classification accuracy for classification of FDG-PET brain images of normal controls and dementia patients, comparable with alternative approaches, and provides a compact set of features selected.

  8. FDG-PET predicts survival in recurrent high-grade gliomas treated with bevacizumab and irinotecan

    PubMed Central

    Colavolpe, Cécile; Chinot, Olivier; Metellus, Philippe; Mancini, Julien; Barrie, Maryline; Bequet-Boucard, Céline; Tabouret, Emeline; Mundler, Olivier; Figarella-Branger, Dominique; Guedj, Eric

    2012-01-01

    Prognosis of recurrent high-grade glioma (HGG) is poor, although bevacizumab has been documented in that context. This study aimed to determine the independent prognostic value of fluorodeoxyglucose (FDG)-PET on progression-free survival (PFS) and overall survival (OS) of recurrent HGG after combined treatment with bevacizumab and irinotecan, compared with other documented prognostic variables. Twenty-five adult patients with histologically proven HGG were included at recurrence. Brain FDG-PET imaging was performed within 6 weeks of starting chemotherapy with bevacizumab and irinotecan. Response based on MRI was assessed every 2 months according to revised assessment in Neuro-Oncology (RANO) criteria. Median PFS and OS were 4 months (range, 0.9–10.4 months) and 7.2 months (range, 1.2–41.7 months), respectively. At 6 months, PFS and OS rate were 16.0% and 72.0%. FDG uptake was the most powerful predictor of both PFS and OS, using either univariate or multivariate analysis, among all variables tested: histological grade, Karnofsky performance status, steroid intake, and number of previous treatments. Moreover, FDG uptake was also prognostic of response to bevacizumab-based therapy. This study provides the first evidence that pretreatment FDG-PET can serve as an imaging biomarker in recurrent HGG for predicting survival following anti-angiogenic therapy with bevacizumab. PMID:22379188

  9. F-18 Labeled Vasoactive Intestinal Peptide Analogue in the PET Imaging of Colon Carcinoma in Nude Mice

    PubMed Central

    Liu, Yuxia; Shen, Hua; Pang, Lifang; Yin, Duanzhi; Wang, Yongxian; Li, Shanqun; Shi, Hongcheng

    2013-01-01

    As large amount of vasoactive intestinal peptide (VIP) receptors are expressed in various tumors and VIP-related diseases, radiolabeled VIP provides a potential PET imaging agent for VIP receptor. However, structural modification of VIP is required before being radiolabeled and used for VIP receptor imaging due to its poor in vivo stability. As a VIP analogue, [R8, 15, 21, L17]-VIP exhibited improved stability and receptor specificity in preliminary studies. In this study, F-18 labeled [R8,15,21, L17]-VIP was produced with the radiochemical yield being as high as 33.6% ± 3% (decay-for-corrected, n = 5) achieved within 100 min, a specific activity of 255 GBq/μmol, and a radiochemical purity as high as 99% as characterized by radioactive HPLC, TLC, and SDS-Page radioautography. A biodistribution study in normal mice also demonstrated fast elimination of F-18 labeled [R8,15,21, L17]-VIP in the blood, liver, and gastrointestinal tracts. A further micro-PET imaging study in C26 colon carcinoma bearing mice confirmed the high tumor specificity, with the tumor/muscle radioactivity uptake ratio being as high as 3.03 at 60 min following injection, and no apparent radioactivity concentration in the intestinal tracts. In addition, blocking experiment and Western Blot test further confirmed its potential in PET imaging of VIP receptor-positive tumor. PMID:24459669

  10. (18)F-FLT and (18)F-FDG PET-CT imaging in the evaluation of early therapeutic effects of chemotherapy on Walker 256 tumor-bearing rats.

    PubMed

    Xu, Weina; Yu, Shupeng; Xin, Jun; Guo, Qiyong

    2016-12-01

    The present study aimed to evaluate the early therapeutic effects of chemotherapy on Walker 256 tumor-bearing Wistar rats via F-18-fluoro-3'-deoxy-3'-L-fluorothymidine ((18)F-FLT) and F-18-fluoro-deoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) imaging. Walker 256 tumor-bearing Wistar rats were subjected to (18)F-FLT and (18)F-FDG PET-CT imaging prior to and 24 and 48 h after epirubicin chemotherapy. (18)F-FLT and (18)F-FDG uptake [tumor/muscle (T/M)], the percentage of injected dose per gram (% ID/g), and the Ki-67 labeling index (LI-Ki-67) were quantitatively determined for each rat prior to and following epirubicin chemotherapy. The correlation between % ID/g and tumor LI-Ki-67 was analyzed. Both (18)F-FLT and (18)F-FDG tumor uptake decreased significantly at 24 and 48 h after chemotherapy (P<0.01 and P<0.05, respectively). LI-Ki-67 also significantly reduced 24 and 48 h after chemotherapy (P<0.001). Furthermore, (18)F-FLT and (18)F-FDG T/M tumor uptake correlated positively with LI-Ki-67 before and after chemotherapy (r=0.842 and 0.813, respectively). During the early post-chemotherapy stage, (18)F-FLT and (18)F-FDG uptake in Walker 256 tumors reduced significantly, which correlated positively with the tumor cell proliferative activity.

  11. 18F-FLT and 18F-FDG PET-CT imaging in the evaluation of early therapeutic effects of chemotherapy on Walker 256 tumor-bearing rats

    PubMed Central

    Xu, Weina; Yu, Shupeng; Xin, Jun; Guo, Qiyong

    2016-01-01

    The present study aimed to evaluate the early therapeutic effects of chemotherapy on Walker 256 tumor-bearing Wistar rats via F-18-fluoro-3′-deoxy-3′-L-fluorothymidine (18F-FLT) and F-18-fluoro-deoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) imaging. Walker 256 tumor-bearing Wistar rats were subjected to 18F-FLT and 18F-FDG PET-CT imaging prior to and 24 and 48 h after epirubicin chemotherapy. 18F-FLT and 18F-FDG uptake [tumor/muscle (T/M)], the percentage of injected dose per gram (% ID/g), and the Ki-67 labeling index (LI-Ki-67) were quantitatively determined for each rat prior to and following epirubicin chemotherapy. The correlation between % ID/g and tumor LI-Ki-67 was analyzed. Both 18F-FLT and 18F-FDG tumor uptake decreased significantly at 24 and 48 h after chemotherapy (P<0.01 and P<0.05, respectively). LI-Ki-67 also significantly reduced 24 and 48 h after chemotherapy (P<0.001). Furthermore, 18F-FLT and 18F-FDG T/M tumor uptake correlated positively with LI-Ki-67 before and after chemotherapy (r=0.842 and 0.813, respectively). During the early post-chemotherapy stage, 18F-FLT and 18F-FDG uptake in Walker 256 tumors reduced significantly, which correlated positively with the tumor cell proliferative activity. PMID:28101193

  12. 18F-FDG super bone marrow uptake

    PubMed Central

    Alam, Mohammed Shah; Fu, Lilan; Ren, Yun-Yan; Wu, Hu-Bing; Wang, Quan-Shi; Han, Yan-Jiang; Zhou, Wen-Lan; Li, Hong-Sheng; Wang, Zhen

    2016-01-01

    Abstract The present study was performed to investigate whether the markedly 2-deoxy-2-(fluorine-18) fluoro-D-glucose (18F-FDG) uptake in the bone marrow (BM) is a presentation of malignant infiltration (MI). Super bone marrow uptake (super BMU) was used to name the markedly 18F-FDG uptake on BM, which was similar to or higher than that of the brain. From April 2008 to December 2015, 31 patients with such presentation were retrospectively reviewed. The 18F-FDG uptake was semiquantified using SUVmax and BM to cerebellum (BM/C) ratio. The origin of super BMU was diagnosed by pathology. Some blood parameters, as well as fever, were also collected and analyzed. For comparison, 106 patients with mildly and moderately uptake in BM and 20 healthy subjects were selected as the control group. Bone marrow MI was diagnosed in 93.5% (29/31) patients with super BMU, which mostly originated from acute leukemia and highly aggressive lymphoma. The super BMU group had markedly higher 18F-FDG uptake in the BM than those of mildly and moderately uptake, and the control subjects (all P = 0.000) and the BM/C ratio reached a high of 1.24 ± 0.36. The incidence of bone marrow MI in the super BMU group was markedly higher than that of mildly and moderately uptake (93.5% vs 36.8%, P = 0.000). Based on the receiver operating characteristic analysis, when cut-off values of BM/C and SUVmax were set at 0.835 and 6.560, the diagnostic specificity for bone marrow MI reached the high levels of 91.4% and 95.7%, respectively. In 15 patients with bone marrow MI, the extra-BM malignant lesions were simultaneously detected by 18F-FDG PET/CT. The liver and the nasal cavity involvements were only found in the patients with lymphoma, but not in those with leukemia. A decrease of leukocyte, hemoglobin, and platelet counts was noted in 48.4%, 86.2%, and 51.5% of patients with bone marrow MI, respectively. The present study revealed that super BMU was a highly potent indicator for the bone

  13. 18-FDG in diabetes mellitus

    NASA Astrophysics Data System (ADS)

    Fares, Y.; Itoh, M.; Watabe, H.; Ghista, D. N.

    1993-06-01

    The intravenous glucose tolerance test, IVGTT, has been used to evaluate patients in whom abnormalities in carbohydrate metabolism and diabetes mellitus are suspected. IVGTT, if analyzed using "minimal models", or discrete-time methods, provides information on the sensitivity of glucose disappearance to insulin and on pancreatic sensitivity to glucose, information that cannot be obtained from direct analysis of the dynamic response alone. In a preliminary study, data obtained by intravenously injecting 18-FDG in four subjects was analyzed using a discrete-time model. The experimental details, the results and their implications will be discussed.

  14. Structure/Function Analysis of the Vaccinia Virus F18 Phosphoprotein, an Abundant Core Component Required for Virion Maturation and Infectivity▿

    PubMed Central

    Wickramasekera, Nadi T.; Traktman, Paula

    2010-01-01

    Poxvirus virions, whose outer membrane surrounds two lateral bodies and a core, contain at least 70 different proteins. The F18 phosphoprotein is one of the most abundant core components and is essential for the assembly of mature virions. We report here the results of a structure/function analysis in which the role of conserved cysteine residues, clusters of charged amino acids and clusters of hydrophobic/aromatic amino acids have been assessed. Taking advantage of a recombinant virus in which F18 expression is IPTG (isopropyl-β-d-thiogalactopyranoside) dependent, we developed a transient complementation assay to evaluate the ability of mutant alleles of F18 to support virion morphogenesis and/or to restore the production of infectious virus. We have also examined protein-protein interactions, comparing the ability of mutant and WT F18 proteins to interact with WT F18 and to interact with the viral A30 protein, another essential core component. We show that F18 associates with an A30-containing multiprotein complex in vivo in a manner that depends upon clusters of hydrophobic/aromatic residues in the N′ terminus of the F18 protein but that it is not required for the assembly of this complex. Finally, we confirmed that two PSSP motifs within F18 are the sites of phosphorylation by cellular proline-directed kinases in vitro and in vivo. Mutation of both of these phosphorylation sites has no apparent impact on virion morphogenesis but leads to the assembly of virions with significantly reduced infectivity. PMID:20392848

  15. Brain ¹⁸F-FDG and ¹¹C-PiB PET findings in two siblings with FTD/ALS associated with the C9ORF72 repeat expansion.

    PubMed

    Martikainen, Mika H; Gardberg, Maria; Jansson, Lilja; Röyttä, Matias; Rinne, Juha O; Kaasinen, Valtteri

    2014-04-01

    The C9ORF72 hexanucleotide expansion is a major pathological expansion pattern found in patients with frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (C9FTD/ALS). We describe a patient in whom early clinical evaluation, MRI and fluorodeoxyglucose (FDG) positron emission tomography (PET) findings failed to definitively differentiate between FTD and Alzheimer's disease (AD), whereas (11)C-Pittsburgh compound B (PiB) PET was negative for amyloid pathology. He later developed ALS symptoms, and post mortem neuropathological findings were diagnostic of FTD-ALS, while no findings suggested AD. His sister was diagnosed with FTD, and the C9ORF72 expansion was detected in both siblings. We conclude that ¹¹C-PiB PET imaging may help the early differential diagnosis between AD and FTD, including C9FTD/ALS.

  16. Electronic structures and nonlinear optical properties of highly deformed halofullerenes C(3v) C60F18 and D(3d) C60Cl30.

    PubMed

    Tang, Shu-Wei; Feng, Jing-Dong; Qiu, Yong-Qing; Sun, Hao; Wang, Feng-Di; Chang, Ying-Fei; Wang, Rong-Shun

    2010-11-15

    Electronic structures and nonlinear optical properties of two highly deformed halofullerenes C(3v) C(60)F(18) and D(3d) C(60)Cl(30) have been systematically studied by means of density functional theory. The large energy gaps (3.62 and 2.61 eV) between the highest occupied and lowest unoccupied molecular orbitals (HOMOs and LUMOs) and the strong aromatic character (with nucleus-independent chemical shifts varying from -15.08 to -23.71 ppm) of C(60)F(18) and C(60)Cl(30) indicate their high stabilities. Further investigations of electronic property show that C(60)F(18) and C(60)Cl(30) could be excellent electron acceptors for potential photonic/photovoltaic applications in consequence of their large vertical electron affinities. The density of states and frontier molecular orbitals are also calculated, which present that HOMOs and LUMOs are mainly distributed in the tortoise shell subunit of C(60)F(18) and the aromatic [18] trannulene ring of C(60)Cl(30), and the influence from halogen atoms is secondary. In addition, the static linear polarizability and second-order hyperpolarizability of C(60)F(18) and C(60)Cl(30) are calculated using finite-field approach. The values of and for C(60)F(18) and C(60)Cl(30) molecules are significantly larger than those of C(60) because of their lower symmetric structures and high delocalization of pi electrons.

  17. FDG PET Imaging in Pneumocystis Pneumonia.

    PubMed

    Kono, Masanori; Yamashita, Hiroyuki; Kubota, Kazuo; Kano, Toshikazu; Mimori, Akio

    2015-08-01

    A 69-year-old woman with rheumatoid arthritis and pleuritis presented with dyspnea. On admission, she was afebrile and had an oxygen saturation of 97% on ambient air. Chest radiography and CT revealed only subtle ground-glass opacities. However, FDG PET revealed pathological uptake in both lungs. A diagnosis of Pneumocystis pneumonia was made based on a positive β-D-glucan assay and polymerase chain reaction amplification of Pneumocystis jirovecii from the sputum. Posttreatment FDG PET revealed resolution of the previously noted uptake. This case illustrates that FDG PET can be used to diagnose Pneumocystis pneumonia when the CT findings are equivocal.

  18. In-flight flow visualization with pressure measurements at low speeds on the NASA F-18 high alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Delfrate, John H.; Fisher, David F.; Zuniga, Fanny A.

    1990-01-01

    In-flight results from surface and off-surface flow visualizations and from extensive pressure distributions document the vortical flow on the leading edge extensions (LEX) and forebody of the NASA F-18 high alpha research vehicle for low speeds and angles of attack up to 50 degs. Surface flow visualization data, obtained using the emitted fluid technique, were used to define separation lines and laminar separation bubbles. Off-surface flow visualization data, obtained by smoke injection, were used to document both the path of the vortex cores and the location of vortex core breakdown. The location of vortex core breakdown correlated well with the loss of suction pressure on the LEX and with the flow visualization results from ground facilities. Surface flow separation lines on the LEX and forebody corresponded well with the end of pressure recovery under the vortical flows. Correlation of the pressures with wind tunnel results show fair to good correlation.

  19. Lockheed L-1011 TriStar to support Adaptive Performance Optimization study with NASA F-18 chase plan

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This Lockheed L-1011 Tristar, seen here June 1995, is currently the subject of a new flight research experiment developed by NASA's Dryden Flight Research Center, Edwards, California, to improve the effiecency of large transport aircraft. Shown with a NASA F-18 chase plane over California's Sierra Nevada mountains during an earlier baseline flight, the jetliner operated by Oribtal Sciences Corp., recently flew its first data-gathering mission in the Adaptive Performance Optimization project. The experiment seeks to reduce fuel comsumption of large jetliners by improving the aerodynamic efficiency of their wings at cruise conditions. A research computer employing a sophisticated software program adapts to changing flight conditions by commanding small movements of the L-1011's outboard ailerons to give its wings the most efficient - or optimal - airfoil. Up to a dozen research flights will be flown in the current and follow-on phases of the project over the next couple years.

  20. F-18 SRA closeup of nose cap showing L-Probe experiment and standard air data sensors

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This under-the-nose view of a modified F-18 Systems Research Aircraft at NASA's Dryden Flight Research Center, Edwards, California, shows three critical components of the aircraft's air data systems which are mounted on both sides of the forward fuselage. Furthest forward are two L-probes that were the focus of the recent Advanced L-probe Air Data Integration (ALADIN) experiment. Behind the L-probes are angle-of-attack vanes, while below them are the aircraft's standard pitot-static air data probes. The ALADIN experiment focused on providing pilots with angle-of-attack and angle-of-sideslip air data as well as traditional airspeed and altitude information, all from a single system. Once fully developed, the new L-probes have the potential to give pilots more accurate air data information with less hardware.

  1. In-flight flow visualization characteristics of the NASA F-18 high alpha research vehicle at high angles of attack

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Delfrate, John H.; Richwine, David M.

    1991-01-01

    Surface and off-surface flow visualization techniques were used to visualize the 3-D separated flows on the NASA F-18 high alpha research vehicle at high angles of attack. Results near the alpha = 25 to 26 deg and alpha = 45 to 49 deg are presented. Both the forebody and leading edge extension (LEX) vortex cores and breakdown locations were visualized using smoke. Forebody and LEX vortex separation lines on the surface were defined using an emitted fluid technique. A laminar separation bubble was also detected on the nose cone using the emitted fluid technique and was similar to that observed in the wind tunnel test, but not as extensive. Regions of attached, separated, and vortical flow were noted on the wing and the leading edge flap using tufts and flow cones, and compared well with limited wind tunnel results.

  2. PET/CT in giant cell arteritis: High (18)F-FDG uptake in the temporal, occipital and vertebral arteries.

    PubMed

    Rehak, Z; Vasina, J; Ptacek, J; Kazda, T; Fojtik, Z; Nemec, P

    (18)F-FDG PET/CT imaging is useful in patients with fever of unknown origin and can detect giant cell arteritis in extracranial large arteries. However, it is usually assumed that temporal arteries cannot be visualized with a PET/CT scanner due to their small diameter. Three patients with clinical symptoms of temporal arteritis were examined using a standard whole body PET/CT protocol (skull base - mid thighs) followed by a head PET/CT scan using the brain protocol. High (18)F-FDG uptake in the aorta and some arterial branches were detected in all 3 patients with the whole body protocol. Using the brain protocol, head imaging led to detection of high (18)F-FDG uptake in temporal arteries as well as in their branches (3 patients), in occipital arteries (2 patients) and also in vertebral arteries (3 patients).

  3. Suture Granuloma With False-Positive Findings on FDG-PET/CT Resected via Laparoscopic Surgery.

    PubMed

    Takeshita, Nobuyoshi; Tohma, Takayuki; Miyauchi, Hideaki; Suzuki, Kazufumi; Nishimori, Takanori; Ohira, Gaku; Narushima, Kazuo; Imanishi, Shunsuke; Toyozumi, Takeshi; Matsubara, Hisahiro

    2015-04-01

    A 61-year-old woman who had undergone total hysterectomy 16 years previously exhibited a pelvic tumor on computed tomography (CT). F-18 fluorodeoxyglucose (FDG) combined positron emission tomography (PET)/CT imaging revealed a solitary small focus of increased FDG activity in the pelvis. A gastrointestinal stromal tumor originating in the small intestine or another type of tumor originating in the mesentery (desmoid, schwannoma, or foreign body granuloma) was suspected; therefore, laparoscopic resection was conducted. A white, hard tumor was found to originate from the mesentery of the sigmoid colon and adhered slightly to the small intestine. The tumor was resected with a negative margin, and the pathologic diagnosis was suture granuloma. The possibility of suture granuloma should be kept in mind in cases of tumors with positive PET findings and a history of surgery close to the lesion. However, it is difficult to preoperatively diagnose pelvic tumors using a biopsy. Therefore, considering the possibility of malignancy, it is necessary to achieve complete resection without exposing the tumor.

  4. (99m)Tc-DMSA (V) in Evaluation of Osteosarcoma: Comparative Studies with (18)F-FDG PET/CT in Detection of Primary and Malignant Lesions.

    PubMed

    Bandopadhyaya, G P; Gupta, Priyanka; Singh, Archana; Shukla, Jaya; Rastogi, S; Kumar, Rakesh; Malhotra, Arun

    2012-01-01

    To evaluate the role of (99m)Tc-DMSA (V) and [(18)F]FDG PET-CT in management of patients with osteosarcoma, 22 patients were included in our study. All patients underwent both (99m)Tc-DMSA (V) and whole-body [(18)F]FDG PET-CT scans within an interval of 1 week. 555-740 MBq of (99m)Tc-DMSA (V) was injected i.v. the whole-body planar, SPECT images of primary site and chest were performed after 3-4 hours. [(18)F]FDG PET-CT images were obtained 60 minutes after i.v. injection of 370 MBq of F-18 FDG. Both FDG PET-CT (mean SUV(max) = 7.1) and DMSA (V) scans showed abnormal uptake at primary site in all the 22 patients (100% sensitivity for both). Whole-body PET-CT detected metastasis in 11 pts (lung mets in 10 and lung + bone mets in 1 patient). Whole-body planar DMSA (V) and SPECT detected bone metastasis in one patient, lung mets in 7 patients and LN in 1 patient. HRCT of chest confirmed lung mets in 10 patients and inflammatory lesion in one patient. 7 patients positive for mets on DMSA (V) scan had higher uptake in lung lesions as compared to FDG uptake on PET-CT. Three patients who did not show any DMSA uptake had subcentimeter lung nodule. Resuts of both (99m)Tc-DMSA (V) (whole-body planar and SPECT imaging) and [(18)F]FDG PET-CT were comparable in evaluation of primary site lesions and metastatic lesions greater than 1 cm. Though (99m)Tc-DMSA (V) had higher uptake in the lesions as compared to [(18)F]FDG PET-CT, the only advantage [(18)F]FDG PET-CT had was that it could also detect subcentimeter lesions.

  5. The extent of resection of FDG-PET hypometabolism relates to outcome of temporal lobectomy.

    PubMed

    Vinton, Anita B; Carne, Ross; Hicks, Rodney J; Desmond, Patricia M; Kilpatrick, Christine; Kaye, Andrew H; O'Brien, Terence J

    2007-02-01

    A significant minority of patients undergoing surgery for medically refractory non-lesional temporal lobe epilepsy (TLE) continue to have seizures, but the reasons for this are uncertain. Fluorodeoxyglucose (FDG) PET shows hypometabolism in a majority of patients with non-lesional TLE, even in the absence of hippocampal atrophy. We examined whether the extent of resection of the area of FDG-PET hypometabolism influenced outcome following surgery for non-lesional TLE. Twenty-six patients who underwent temporal lobectomy for medically refractory TLE with at least 12 months follow-up were studied. The preoperative FDG-PET was compared with 20 non-epileptic controls using SPM99 to identify regions of significant hypometabolism (P < 0.0005, cluster > 200). This image was then co-registered to the postoperative MRI scan. The volume of the FDG-PET hypometabolism that lay within the area of the resected temporal lobe was calculated. The volume of temporal lobe resected was also calculated. Patients with a good outcome had a greater proportion of the total FDG-PET hypometabolism volume resected than those with a poor outcome (24.1% versus 11.8%, P = 0.02). There was no significant difference between the groups in the volume of temporal lobe resected (P = 0.86). Multivariate regression demonstrated that the extent of resection of the hypometabolism significantly correlated with outcome (P = 0.03), independent of the presence of hippocampal sclerosis (P = 0.03) and total brain volume of hypometabolism (P = 0.45). The extent of resection of the region of hypometabolism on the preoperative FDG-PET is predictive of outcome following surgery for non-lesional TLE. Strategies that tailor resection extent to regional hypometabolism may warrant further evaluation.

  6. Brain heterotopia.

    PubMed

    Modarresifar, Homayoun; Ho, Linh

    2009-03-01

    We present a case with intractable partial complex seizures in a 14-year-old girl who was found to have brain heterotopia on MRI and PET-CT. The patient presented with intractable partial complex seizures and a normal electroencephalogram. Her brain magnetic resonance imaging showed heterotopic gray matter lining the ventricular margin of the right occipital horn. Subsequent PET-CT demonstrated moderate tracer localization in the heterotopic gray matter surrounding the ventricular margin of the right occipital horn. Heterotopia may demonstrate normal or increased FDG uptake on PET, therefore its appearance may be deceiving when other pathologies are being considered.

  7. 18F-FDG positron autoradiography with a particle counting silicon pixel detector.

    PubMed

    Russo, P; Lauria, A; Mettivier, G; Montesi, M C; Marotta, M; Aloj, L; Lastoria, S

    2008-11-07

    We report on tests of a room-temperature particle counting silicon pixel detector of the Medipix2 series as the detector unit of a positron autoradiography (AR) system, for samples labelled with (18)F-FDG radiopharmaceutical used in PET studies. The silicon detector (1.98 cm(2) sensitive area, 300 microm thick) has high intrinsic resolution (55 microm pitch) and works by counting all hits in a pixel above a certain energy threshold. The present work extends the detector characterization with (18)F-FDG of a previous paper. We analysed the system's linearity, dynamic range, sensitivity, background count rate, noise, and its imaging performance on biological samples. Tests have been performed in the laboratory with (18)F-FDG drops (37-37 000 Bq initial activity) and ex vivo in a rat injected with 88.8 MBq of (18)F-FDG. Particles interacting in the detector volume produced a hit in a cluster of pixels whose mean size was 4.3 pixels/event at 11 keV threshold and 2.2 pixels/event at 37 keV threshold. Results show a sensitivity for beta(+) of 0.377 cps Bq(-1), a dynamic range of at least five orders of magnitude and a lower detection limit of 0.0015 Bq mm(-2). Real-time (18)F-FDG positron AR images have been obtained in 500-1000 s exposure time of thin (10-20 microm) slices of a rat brain and compared with 20 h film autoradiography of adjacent slices. The analysis of the image contrast and signal-to-noise ratio in a rat brain slice indicated that Poisson noise-limited imaging can be approached in short (e.g. 100 s) exposures, with approximately 100 Bq slice activity, and that the silicon pixel detector produced a higher image quality than film-based AR.

  8. FDG-PET/CT Limited to the Thorax and Upper Abdomen for Staging and Management of Lung Cancer

    PubMed Central

    Postema, Jan W. A.; Schreurs, Wendy M. J.; Lafeber, Albert; Hendrickx, Baudewijn W.; Oyen, Wim J. G.; Vogel, Wouter V.

    2016-01-01

    Purpose This study evaluates the diagnostic accuracy of [F-18]-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) of the chest/upper abdomen compared to the generally performed scan from head to upper thighs, for staging and management of (suspected) lung cancer in patients with no history of malignancy or complaints outside the thorax. Methods FDG-PET/CT scans of 1059 patients with suspected or recently proven lung cancer, with no history of malignancy or complaints outside the thorax, were analysed in a retrospective multi-centre trial. Suspect FDG-avid lesions in the chest and upper abdomen, the head and neck area above the shoulder line and in the abdomen and pelvis below the caudal tip of the liver were noted. The impact of lesions detected in the head and neck area and abdomen and pelvis on additional diagnostic procedures, staging and treatment decisions was evaluated. Results The head and neck area revealed additional suspect lesions in 7.2%, and the abdomen and pelvis in 15.8% of patients. Imaging of the head and neck area and the abdomen and pelvic area showed additional lesions in 19.5%, inducing additional diagnostic procedures in 7.8%. This resulted in discovery of additional lesions considered malignant in 10.7%, changing patient management for lung cancer in 1.2%. In (suspected) lung cancer, PET/CT limited to the chest and upper abdomen resulted in correct staging in 98.7% of patients, which led to the identical management as full field of view PET in 98.8% of patients. Conclusion High value of FDG-PET/CT for staging and correct patient management is already achieved with chest and upper abdomen. Findings in head and neck area and abdomen and pelvis generally induce investigations with limited or no impact on staging and treatment of NSCLC, and can be interpreted accordingly. PMID:27556809

  9. Posttransplant Lymphoproliferative Disorder of the Thorax: CT and FDG-PET Features in a Single Tertiary Referral Center

    PubMed Central

    Yoon, Ga Young; Kim, Mi Young; Huh, Joo Rryung; Jo, Kyung-Wook; Shim, Tae Sun

    2015-01-01

    Abstract To investigate the chest computed tomography (CT) and F-18 fluoro-2-deoxy-d-glucose positron emission tomographic (FDG-PET) findings of posttransplant lymphoproliferative disorder (PTLD) in the thorax. From November 2004 to February 2013, the cases of 12 adult patients (3 female and 9 male, age range 34–68, and median age 46 years) with proven PTLD were retrospectively reviewed. The transplanted organs included the kidney (5/12), liver (4/12), heart (1/12), combined kidney and pancreas (1/12), and hematopoietic stem cell (1/12). We investigated the relationship of the Epstein–Barr virus (EBV) to the patients’ long-term follow-up, and evaluated the characteristics of the lesions on the chest CT and FDG-PET. The lesions were classified into 2 patterns: that of lymph node and lung involvement. The interval between the transplantation and the onset of PTLD was 2 to 128 months (median, 49). Positive EBV-encoded RNA in the pathologic specimens was found in 10 patients (83.3%). Eight patients were positive for EBV PCR in their blood, and 3 patients showed seroconversion without antiviral therapy. The responses to treatment were complete in 7 cases (58.3%), partial remission in 4 cases (33.3%), and undetermined in 1 case (8.3%). The more common chest CT patterns showed lymph node involvement (10/12) rather than lung involvement (3/12). The median maximum-standardized uptake value on the FDG-PET scans was 7.7 (range, 2.7–25.5). In patients with PTLD involving the thorax, lymphadenopathy was the more common manifestation on the chest CT rather than lung involvement. The lesions showed hypermetabolism on FDG-PET. PMID:26252295

  10. Radioactive by-products of a self-shielded cyclotron and the liquid target system for F-18 routine production.

    PubMed

    Kambali, I; Suryanto, H; Parwanto

    2016-06-01

    Routine production of F-18 radionuclide using proton beams accelerated in a cyclotron could potentially generate residual radioisotopes in the cyclotron vicinity which eventually become major safety concerns over radiation exposure to the workers. In this investigation, a typical 11-MeV proton, self-shielded cyclotron has been assessed for its residual radiation sources in the cyclotron's shielding, tank/chamber, cave wall as well as target system. Using a portable gamma ray spectroscopy system, the radiation measurement in the cyclotron environment has been carried out. Experimental results indicate that relatively long-lived radioisotopes such as Mn-54, Zn-65 and Eu-152 are detected in the inner and outer surface of the cyclotron shielding respectively while Mn-54 spectrum is observed around the cyclotron chamber. Weak intensity of Eu-152 radioisotope is again spotted in the inner and outer surface of the cyclotron cave wall. Angular distribution measurement of the Eu-152 shows that the intensity slightly drops with increasing observation angle relative to the proton beam incoming angle. In the target system, gamma rays from Co-56, Mn-52, Co-60, Mn-54, Ag-110 m are identified. TALYS-calculated nuclear cross-section data are used to study the origins of the radioactive by-products.

  11. Extraction of Lateral-Directional Stability and Control Derivatives for the Basic F-18 Aircraft at High Angles of Attack

    NASA Technical Reports Server (NTRS)

    Iliff, Kenneth W.; Wang, Kon-Sheng Charles

    1997-01-01

    The results of parameter identification to determine the lateral-directional stability and control derivatives of an F-18 research aircraft in its basic hardware and software configuration are presented. The derivatives are estimated from dynamic flight data using a specialized identification program developed at NASA Dryden Flight Research Center. The formulation uses the linearized aircraft equations of motions in their continuous/discrete form and a maximum likelihood estimator that accounts for both state and measurement noise. State noise is used to model the uncommanded forcing function caused by unsteady aerodynamics, such as separated and vortical flows, over the aircraft. The derivatives are plotted as functions of angle of attack between 3 deg and 47 deg and compared with wind-tunnel predictions. The quality of the derivative estimates obtained by parameter identification is somewhat degraded because the maneuvers were flown with the aircraft's control augmentation system engaged, which introduced relatively high correlations between the control variables and response variables as a result of control motions from the feedback control system.

  12. Computational fluid dynamics simulation of the air/suppressant flow in an uncluttered F18 engine nacelle

    SciTech Connect

    Lopez, A.R.; Gritzo, L.A.; Hassan, B.

    1997-06-01

    For the purposes of designing improved Halon-alternative fire suppression strategies for aircraft applications, Computational Fluid Dynamics (CFD) simulations of the air flow, suppressant transport, and air-suppressant mixing within an uncluttered F18 engine nacelle were performed. The release of inert gases from a Solid Propellant Gas Generator (SPGG) was analyzed at two different injection locations in order to understand the effect of injection position on the flow patterns and the mixing of air and suppression agent. An uncluttered engine nacelle was simulated to provide insight into the global flow features as well as to promote comparisons with previous nacelle fire tests and recent water tunnel tests which included little or no clutter. Oxygen concentration levels, fuel/air residence times that would exist if a small fuel leak were present, velocity contours, and streamline patterns are presented inside the engine nacelle. The numerical results show the influence of the gent release location on regions of potential flame extinction due to oxygen inerting and high flame strain. The occurrence of inflow through the exhaust ducts on the aft end of the nacelle is also predicted. As expected, the predicted oxygen concentration levels were consistently higher than the measured levels since a fire was not modeled in this analysis. Despite differences in the conditions of these simulations and the experiments, good agreement was obtained between the CFD predictions and the experimental measurements.

  13. Validation of an optimized SPM procedure for FDG-PET in dementia diagnosis in a clinical setting

    PubMed Central

    Perani, Daniela; Della Rosa, Pasquale Anthony; Cerami, Chiara; Gallivanone, Francesca; Fallanca, Federico; Vanoli, Emilia Giovanna; Panzacchi, Andrea; Nobili, Flavio; Pappatà, Sabina; Marcone, Alessandra; Garibotto, Valentina; Castiglioni, Isabella; Magnani, Giuseppe; Cappa, Stefano F.; Gianolli, Luigi

    2014-01-01

    Diagnostic accuracy in FDG-PET imaging highly depends on the operating procedures. In this clinical study on dementia, we compared the diagnostic accuracy at a single-subject level of a) Clinical Scenarios, b) Standard FDG Images and c) Statistical Parametrical (SPM) Maps generated via a new optimized SPM procedure. We evaluated the added value of FDG-PET, either Standard FDG Images or SPM Maps, to Clinical Scenarios. In 88 patients with neurodegenerative diseases (Alzheimer's Disease—AD, Frontotemporal Lobar Degeneration—FTLD, Dementia with Lewy bodies—DLB and Mild Cognitive Impairment—MCI), 9 neuroimaging experts made a forced diagnostic decision on the basis of the evaluation of the three types of information. There was also the possibility of a decision of normality on the FDG-PET images. The clinical diagnosis confirmed at a long-term follow-up was used as the gold standard. SPM Maps showed higher sensitivity and specificity (96% and 84%), and better diagnostic positive (6.8) and negative (0.05) likelihood ratios compared to Clinical Scenarios and Standard FDG Images. SPM Maps increased diagnostic accuracy for differential diagnosis (AD vs. FTD; beta 1.414, p = 0.019). The AUC of the ROC curve was 0.67 for SPM Maps, 0.57 for Clinical Scenarios and 0.50 for Standard FDG Images. In the MCI group, SPM Maps showed the highest predictive prognostic value (mean LOC = 2.46), by identifying either normal brain metabolism (exclusionary role) or hypometabolic patterns typical of different neurodegenerative conditions. PMID:25389519

  14. FDG uptake, a surrogate of tumour hypoxia?

    PubMed Central

    Van de Wiele, Christophe

    2008-01-01

    Introduction Tumour hyperglycolysis is driven by activation of hypoxia-inducible factor-1 (HIF-1) through tumour hypoxia. Accordingly, the degree of 2-fluro-2-deoxy-d-glucose (FDG) uptake by tumours might indirectly reflect the level of hypoxia, obviating the need for more specific radiopharmaceuticals for hypoxia imaging. Discussion In this paper, available data on the relationship between hypoxia and FDG uptake by tumour tissue in vitro and in vivo are reviewed. In pre-clinical in vitro studies, acute hypoxia was consistently shown to increase FDG uptake by normal and tumour cells within a couple of hours after onset with mobilisation or modification of glucose transporters optimising glucose uptake, followed by a delayed response with increased rates of transcription of GLUT mRNA. In pre-clinical imaging studies on chronic hypoxia that compared FDG uptake by tumours grown in rat or mice to uptake by FMISO, the pattern of normoxic and hypoxic regions within the human tumour xenografts, as imaged by FMISO, largely correlated with glucose metabolism although minor locoregional differences could not be excluded. In the clinical setting, data are limited and discordant. Conclusion Further evaluation of FDG uptake by various tumour types in relation to intrinsic and bioreductive markers of hypoxia and response to radiotherapy or hypoxia-dependent drugs is needed to fully assess its application as a marker of hypoxia in the clinical setting. PMID:18509637

  15. Estimated radiation dose to the newborn in FDG-PET studies

    SciTech Connect

    Ruotsalainen, U.; Suhonen-Polvi, H.; Eronen, E.; Kinnala, A.

    1996-02-01

    The aim of this study was to estimate the radiation dose due to intravenous injection of 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (FDG) for infants studied with PET. The radioactivity concentration in the brain and bladder content was measured with PET to determine the cumulated activity in these organs in 21 infant FDG studies. The individual organ masses were estimated according to the whole-body and brain masses, and they were used to calculate the absorbed dose per unit cumulated activity (S values). For organs other than brain and bladder, the cumulated activity was defined from adult studies. For each individual patient, the absorbed dose to the brain, bladder wall and selected organs were calculated. An estimation of the effective dose was determined. Whole-body distribution of FDG in the infants differed from adults: a greater proportion of the injected activity accumulated into the brain (9% versus 7%) and less was excreted to urine (7% versus 20% respectively). The measured cumulated activity in the brain was 0.25 MBq {center_dot} h/MBq and in the bladder content 0.04 MBq {center_dot}h/MBq with a large individual variation in latter. The calculated absorbed dose was 0.24 mGy/MBq to the brain and 1.03 mGy/MBq to the bladder wall. The estimated effective dose was 0.43 mSv/MBq. The dose to the bladder wall was lower in infants as compared to adults with ordinary amounts of injected activity. The greater amount of activity remaining in the body may increase the dose to other organs. The effective dose was lower compared to adults and conventional nuclear medicine studies of infants. PET can be a valuable tool in pediatric nuclear medicine because of good resolution images, sensitive radiation measurement and a variety of tracers labeled with short-lived isotopes. 27 refs., 4 figs., 2 tabs.

  16. Correlation between direct microscopy and FDG-PET in the study of cerebral blood flow in rats

    NASA Astrophysics Data System (ADS)

    Blagosklonov, Oleg; Podoprigora, Guennady I.; Pushkin, Sergey V.; Nartsissov, Yaroslav R.; Comas, Laurent; Cardot, Jean-Claude; Boulahdour, Hatem

    2007-07-01

    Isotope studies provide valuable data about an organ's function in vivo. Thanks to positron emission tomography (PET) using the radiolabeled natural metabolites, such as [18F]-2-fluoro-deoxy-d-glucose (FDG), biological and physiological meaning of nuclear medicine scans has been considerably increased. Therefore it is of interest to elucidate the possibilities of the technique in a study of some natural metabolites like glycine influencing the blood microcirculation. Glycine, as a medicine, was recently shown to have a positive therapeutic effect in the treatment of patients with ischemic stroke and some other neurological disorders based on vascular disturbances. By previous direct biomicroscopic investigations of pial microvessels in laboratory rats an expressed vasodilatory effect of topically applied glycine was proved. The arterioles diameters depending on initial size have been increased by 200-250% for arterioles of 20-40 μm and by 150-200% for arterioles of 50-80 μm. The PET images were acquired before and after sublingual application of glycine (200 mg). The quantitative analysis of FDG volume concentration (Bq/ml) in the rat brain demonstrated that, in studies after glycine administration, maximal, minimal and mean FDG volume concentration in the brain increased by 200-250% in comparison with the baseline data. Thus, our results revealing evident correlation between FDG-PET images and direct biomicroscopic observations confirm the great potential of molecular imaging techniques to explore in vivo process in the brain.

  17. PREPARATION OF ANHYDROUS F-18 FLUORIDE, T. Tewson. Journal of Labelled Compounds and Radiopharmaceuticals S165; 52, Supplement 1 2009

    SciTech Connect

    Tewson, T.

    2009-07-01

    The original specific aims of the grant where cut back considerably as the study section reduced both the time and the budget for the project. The objective of the grant was to show that fluorine-18 fluoride could be prepared completely anhydrous and thus substantially more reactive than conventionally dried fluoride using the method of Sun and DiMagno. This method involved using conventionally dried fluoride to prepare an aromatic fluoride in which the aromatic ring is substituted with electron withdrawing groups. The aryl fluoride is then dried and purified and the fluoride is displaced with an anhydrous nucleophile. Using fluorine-19 and macroscopic scale reactions the reactions work well and give anhydrous fluoride salts that are both more reactive and more selective in their reactions than conventionally dried fluoride. The original substrate chosen for the reaction was bromopentacyanobenzene (1). This compound proved to be easy to make but very hard to purify. As an alternative hexabromobenzene, which is commercially available in high purity, was tried. This reacted cleanly with conventionally dried F-18 fluoride in acetonitrile to give [{sup 18}F]-fluoropentabromobenzene (2), which could be dried by passage of the solution over alumina, which also removed any unreacted fluoride. The fluorine-18 fluoride could be liberated from (2) by displacement with an anhydrous nucleophilic tetra-alkylammonium salt but the anion had to be chosen with considerable care. The reaction is potentially reversible especially as, on the no carrier added scale, there is inevitably an excess of hexabromobenzene and so the displacing nucleophile is chosen to deactivate the aromatic compound to further nucleophilic displacement reactions. To this end tetrabutylammonium azide and tetrabutylammonium phenolate have been tried. Both work but the phenolate is probably the better choice. The F-18 fluoride produced by this process is substantially more reactive than conventionally dried

  18. Synthesis of no carrier added F-18 16-fluorohexadecanoic acid (FHDA) and investigation of its labeled metabolites and its kinetics in the heart

    SciTech Connect

    DeGrado, T.R.; Bernstein, D.R.; Gatley, S.J.; Ng, C.K.; Holden, J.E.

    1984-01-01

    No carrier added FHDA was prepared via saponification of the product of silver oxide assisted reaction of near-anhydrous tetraethylammonium fluoride with methyl 16-iodohexadecanoate. The labeled fatty acid was injected into isolated perfused rat hearts. Coronary perfusate was collected for 4-9 minutes, when hearts were chilled and homogenized. F-18 in perfusate was analysed by HPLC (NH column; 50mM amm. acetate in 50% acetonitrile). Material with the same retention time as F-18 fluoroacetate (prepared by F-for-I exchange with ethyl iodoacetate) was found. Some F-18 stuck permanently to the column and was assigned as fluoride since the same fraction of label in perfusate was retained on alumina columns eluted with water. Anion exchange HPLC (SAX column; 20mM pot. phosphate, pH 7) of homogenates gave peaks corresponding to fluoroacetate plus fluoride and minor peaks which could be fluoroacetylCoA and fluorocitrate. The authors interpret their data as follows. Beta-oxidation of FHDA results in fluoroacetylCoA which either undergoes ''lethal synthesis'' to fluorocitrate or is hydrolysed to fluoroacetate which diffuses out of the heart. The source of the fluoride is not yet clear, but could complicate interpretation of FHDA kinetics measured in vivo with positron tomography. Clearance of label from FHDA in isolated perfused hearts was faster than for labeled 16-iodohexadecanoic acid, indicating that the F-18 tracer may be a more sensitive probe of myocardial fatty acid metabolism.

  19. FDG-PET and Neuropsychiatric Symptoms among Cognitively Normal Elderly Persons: The Mayo Clinic Study of Aging

    PubMed Central

    Krell-Roesch, Janina; Ruider, Hanna; Lowe, Val J.; Stokin, Gorazd B.; Pink, Anna; Roberts, Rosebud O.; Mielke, Michelle M.; Knopman, David S.; Christianson, Teresa J.; Machulda, Mary M.; Jack, Clifford R.; Petersen, Ronald C.; Geda, Yonas E.

    2016-01-01

    One of the key research agenda of the field of aging is investigation of presymptomatic Alzheimer’s disease (AD). Furthermore, abnormalities in brain glucose metabolism (as measured by FDG-PET) have been reported among cognitively normal elderly persons. However, little is known about the association of FDG-PET abnormalities with neuropsychiatric symptoms (NPS) in a population-based setting. Thus, we conducted a cross-sectional study derived from the ongoing population-based Mayo Clinic Study of Aging in order to examine the association between brain glucose metabolism and NPS among cognitively normal (CN) persons aged > 70 years. Participants underwent FDG-PET and completed the Neuropsychiatric Inventory Questionnaire (NPI-Q), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI). Cognitive classification was made by an expert consensus panel. We conducted multivariable logistic regression analyses to compute odds ratios (OR) and 95% confidence intervals after adjusting for age, sex, and education. For continuous variables, we used linear regression and Spearman rank-order correlations. Of 668 CN participants (median 78.1 years, 55.4% males), 205 had an abnormal FDG-PET (i.e., standardized uptake value ratio < 1.32 in AD-related regions). Abnormal FDG-PET was associated with depression as measured by NPI-Q (OR = 2.12; 1.23–3.64); the point estimate was further elevated for APOE ɛ4 carriers (OR = 2.59; 1.00–6.69), though marginally significant. Additionally, we observed a significant association between abnormal FDG-PET and depressive and anxiety symptoms when treated as continuous measures. These findings indicate that NPS, even in community-based samples, can be an important additional tool to the biomarker-based investigation of presymptomatic AD. PMID:27447426

  20. Estimation of radiation dose to patients from 18FDG whole body PET/CT investigations using dynamic PET scan protocol

    PubMed Central

    Kaushik, Aruna; Jaimini, Abhinav; Tripathi, Madhavi; D’Souza, Maria; Sharma, Rajnish; Mondal, Anupam; Mishra, Anil K.; Dwarakanath, Bilikere S.

    2015-01-01

    Background & objectives: There is a growing concern over the radiation exposure of patients from undergoing 18FDG PET/CT (18F-fluorodeoxyglucose positron emission tomography/computed tomography) whole body investigations. The aim of the present study was to study the kinetics of 18FDG distributions and estimate the radiation dose received by patients undergoing 18FDG whole body PET/CT investigations. Methods: Dynamic PET scans in different regions of the body were performed in 49 patients so as to measure percentage uptake of 18FDG in brain, liver, spleen, adrenals, kidneys and stomach. The residence time in these organs was calculated and radiation dose was estimated using OLINDA software. The radiation dose from the CT component was computed using the software CT-Expo and measured using computed tomography dose index (CTDI) phantom and ionization chamber. As per the clinical protocol, the patients were refrained from eating and drinking for a minimum period of 4 h prior to the study. Results: The estimated residence time in males was 0.196 h (brain), 0.09 h (liver), 0.007 h (spleen), 0.0006 h (adrenals), 0.013 h (kidneys) and 0.005 h (stomach) whereas it was 0.189 h (brain), 0.11 h (liver), 0.01 h (spleen), 0.0007 h (adrenals), 0.02 h (kidneys) and 0.004 h (stomach) in females. The effective dose was found to be 0.020 mSv/MBq in males and 0.025 mSv/MBq in females from internally administered 18FDG and 6.8 mSv in males and 7.9 mSv in females from the CT component. For an administered activity of 370 MBq of 18FDG, the effective dose from PET/CT investigations was estimated to be 14.2 mSv in males and 17.2 mSv in females. Interpretation & conclusions: The present results did not demonstrate significant difference in the kinetics of 18FDG distribution in male and female patients. The estimated PET/CT doses were found to be higher than many other conventional diagnostic radiology examinations suggesting that all efforts should be made to clinically justify and

  1. Diagnostic Value of (18)F-FDG PET/CT versus MRI in the Setting of Antibody Specific Autoimmune Encephalitis.

    PubMed

    Solnes, Lilja B; Jones, Krystyna M; Rowe, Steven P; Pattanayak, Puskar; Nalluri, Abhinav; Venkatesan, Arun; Probasco, John C; Javadi, Mehrbod Som

    2017-02-16

    Introduction: Diagnosis of autoimmune encephalitis presents some challenges in the clinical setting due to varied clinical presentations and delay in obtaining antibody panel results. We examined the role of neuroimaging in the setting of autoimmune encephalitides comparing the utility (18)F-FDG PET/CT versus conventional brain imaging with MRI. Methods: A retrospective study was performed assessing the positivity rate of MRI versus (18)F-FDG PET/CT during the initial work-up of 23 patients proven to have antibody positive autoimmune encephalitis. (18)F-FDG PET/CT studies were analyzed qualitatively and using Cortex ID (GE Health systems). Areas of cortical lobar hypo (hyper) metabolism in the cerebrum that were 2 standard deviations from the mean were recorded as abnormal. Results: On visual inspection, all patients were identified to have abnormal pattern of (18)F-FDG uptake. In semi-quantitative analysis at least one region of interest with metabolic change was identified in 22/23 (95.6%) patients using discriminating Z-score of 2. Overall, (18)F-FDG PET/CT was more often abnormal during the diagnostic period than MRI (10/23, 43% of patients). The predominant finding on brain (18)F-FDG PET/CT imaging was lobar hypometabolism, being observed in 21/23 (91.3%) of patients. Hypometabolism were most commonly observed in parietal lobe following by occipital lobe. An entire subset of antibody positive patients, anti-NMDAR (5 patients), had normal MRIs and abnormal (18)F-FDG PET/CT while other subsets demonstrated a greater heterogeneity. Conclusion: Brain (18)F-FDG PET/CT may play a significant role in initial evaluation of patients with clinically suspected antibody-mediated autoimmune encephalitis. Given that it is more often abnormal when compared with MRI in the acute setting, this molecular imaging technique may be better positioned as an early biomarker of disease so that treatment may be initiated earlier resulting in improved patient outcomes.

  2. FDG-PET in colorectal cancer.

    PubMed

    de Geus-Oei, Lioe-Fee; Ruers, Theo J M; Punt, Cornelis J A; Leer, Jan Willem; Corstens, Frans H M; Oyen, Wim J G

    2006-10-31

    [18F]Fluorodeoxyglucose (FDG) positron emission tomography (PET) is a useful imaging tool in the evolving management of patients with colorectal carcinoma. This technique is able to measure and visualize metabolic changes in cancer cells. This feature results in the ability to distinguish viable tumor from scar tissue, in the detection of tumor foci at an earlier stage than possible by conventional anatomic imaging and in the measurement of alterations in tumor metabolism, indicative of tumor response to therapy. Nowadays, FDG-PET plays a pivotal role in staging patients before surgical resection of recurrence and metastases, in the localization of recurrence in patients with an unexplained rise in serum carcinoembryonic antigen and in assessment of residual masses after treatment. In the presurgical evaluation, FDG-PET may be best used in conjunction with anatomic imaging in order to combine the benefits of both anatomical (CT) and functional (PET) information, which leads to significant improvements in preoperative liver staging and preoperative judgment on the feasibility of resection. Integration of FDG-PET into the management algorithm of these categories of patients alters and improves therapeutic management, reduces morbidity due to futile surgery, leads to substantial cost savings and probably also to a better patient outcome. FDG-PET also appears to have great potential in monitoring the success of local ablative therapies soon after intervention and in the prediction and evaluation of response to radiotherapy, systemic therapy, and combinations thereof. This review aims to outline the current and future role of FDG-PET in the field of colorectal cancer.

  3. 18F-FDG PET/CT in Bladder Cancer.

    PubMed

    Tagliabue, Luca; Russo, Giovanna; Lucignani, Giovanni

    2016-12-01

    Urinary clearance of F-FDG and variability in bladder wall FDG uptake may hamper the interpretation and limit the use of FDG-PET/CT for imaging bladder tumors. Nevertheless, careful combined evaluation of both CT and FDG-PET images of the urinary tract can provide useful findings. We present 2 cases of bladder cancer detected by FDG-PET/CT. These cases suggest that FDG uptake can be indicative of malignancy in bladder cancer when viewed in conjunction with CT scans and that whole-body FDG-PET/CT scans should always be reviewed with particular attention to the urinary tract because abnormalities suggestive of bladder cancer can be found unexpectedly.

  4. The flagella of F18ab Escherichia coli is a virulence factor that contributes to infection in a IPEC-J2 cell model in vitro.

    PubMed

    Duan, Qiangde; Zhou, Mingxu; Zhu, Xiaofang; Bao, Wenbin; Wu, Shenglong; Ruan, Xiaosai; Zhang, Weiping; Yang, Yang; Zhu, Jun; Zhu, Guoqiang

    2012-11-09

    Bacterial flagella contribute to pathogen virulence; however, the role of flagella in the pathogenesis of F18ab E. coli-mediated swine edema disease (ED) is not currently known. We therefore evaluated the role of flagella in F18ab E. coli adhesion, invasion, biofilm formation, and IL-8 production using an in vitro cell infection model approach with gene-deletion mutant and complemented bacterial strains. We demonstrated that the flagellin-deficient fliC mutant had a marked decrease in the ability to adhere to and invade porcine epithelial IPEC-J2 cells. Surprisingly, there was no difference in adhesion between the F18 fimbriae-deficient ΔfedA mutant and its parent strain. In addition, both the ΔfedA and double ΔfliCΔfedA mutants exhibited an increased ability to invade IPEC-J2 cells compared to the wild-type strain, although this may be due to increased expression of other adhesins following the loss of F18ab fimbriae and flagella. Compared to the wild-type strain, the ΔfliC mutant showed significantly reduced ability to form biofilm, whereas the ΔfedA mutant increased biofilm formation. Although ΔfliC, ΔfedA, and ΔfliCΔfedA mutants had a reduced ability to stimulate IL-8 production from infected Caco-2 cells, the ΔfliC mutant impaired this ability to a greater extent than the ΔfedA mutant. The results from this study clearly demonstrate that flagella are required for efficient F18ab E. coli adhesion, invasion, biofilm formation, and IL-8 production in vitro.

  5. FDG-PET findings in patients with galactosaemia.

    PubMed

    Dubroff, J G; Ficicioglu, C; Segal, S; Wintering, N A; Alavi, A; Newberg, A B

    2008-08-01

    Despite treatment with a galactose-restricted diet, many galactosaemia patients develop lifelong cognitive impairment, speech abnormalities and a gamut of neurological problems including cognitive impairment and tremors. No study has explored changes in cerebral glucose metabolism in patients with galactosaemia. Five patients with galactosaemia had ages ranging from 20 to 40 years (mean age 28 years) and eight similarly aged controls received brain [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) scans. PET scans were analysed using a previously validated template methodology of regions of interest (ROIs). Count ratios for each anatomical ROI were compared between the galactosaemic patients and the healthy controls. Statistical parametric mapping (SPM) software was also used to further analyse the data. ROI analysis showed that galactosaemic patients had significant bilateral decreases in cerebral glucose metabolism in the superior temporal gyrus, medial occipital lobe, parietal lobe, cerebellum, calcarine cortex, superior frontal cortex, and superior parietal cortex when compared with controls. Significant increases were seen in the cingulate gyrus and temporal poles, bilaterally. SPM analysis revealed foci of decreased glucose metabolism in the caudate, cerebellum, precentral gyrus and cerebellar tonsils of galactosaemic patients. SPM also showed increased glucose metabolism in the subcallosal gyrus and claustrum. The results show significant abnormalities in cerebral function in patients with galactosaemia, particularly with widespread decreases in cortical metabolism. These abnormalities appear to be in brain regions that may be associated with the neuropsychological deficits in these patients. PET brain scans may be of value in galactosaemia patients to evaluate for dysfunction.

  6. Production of the PET bone agent (18)F-fluoride ion, simultaneously with (18)F-FDG by a single run of the medical cyclotron with minimal radiation exposure- a novel technique.

    PubMed

    Kumar, Rajeev; Sonkawade, Rajendra G; Tripathi, Madhavi; Sharma, Punit; Gupta, Priyanka; Kumar, Praveen; Pandey, Anil K; Bal, Chandrasekhar; Damle, Nishikant Avinash; Bandopadhayaya, Gurupad

    2014-01-01

    Our aim was to establish an easy and convenient procedure for the preparation of fluorine-18-sodium fluoride ((18)F-NaF) for bone positron emission tomography (PET) during routine (18)F-FDG production using the Explora FDG4 radiochemistry module (EFRM) by single run of Cyclotron with negligible radiation exposure. We compared three techniques for (18)F-NaF production during routine PET radiochemistry at our setup. In one method we used synthesis module and in other two methods we did not. In the first and third method, F-18 was directly extracted from the V-vial and in the second method, (18)F-NaF was extracted by post processing from the EFRM. In the first method, F-18 was extracted directly from V-vial manually by opening the V-vial cap. In the second method, Explora FDG-4 Module was used. First, F-18 was transferred from the V-vial. Then, after post processing in EFRM, pure F-18 was obtained in the product vial. In the third method, pure F-18 was obtained in the product vial with the help of a mechanical robotic arm. The above were followed by routine quality control of (18)F-NaF produced by each method. Results of quality control of the (18)F-NaF obtained by all three methods satisfied all parameters prescribed by the United States Pharmacopeia (USP) and the British Pharmacopeia (BP) including biological, physical and chemical specifications. The radiochemical purity was 98.5±1.5% with Rf 0.006. The level of Kryptofix-222 (K222) in (18)F-NaF was within the prescribed limit. Mean pH of (18)F-NaF was 6.0±1.5. The exposure rate around the hot cell was negligible. In conclusion, from the results it was obvious that by our method number three (18)F-NaF was directly obtained from the V-vial using mechanical robotic arms. This method was the most appropriate with minimized radiation exposure to the handling Radiochemist and was also saving time as compared to the other two methods.

  7. A summary of the forebody high-angle-of-attack aerodynamics research on the F-18 and the X-29A aircraft

    NASA Technical Reports Server (NTRS)

    Bjarke, Lisa J.; Delfrate, John H.; Fisher, David F.

    1992-01-01

    High-angle-of-attack aerodynamic studies have been conducted on both the F18 High Alpha Research Vehicle (HARV) and the X-29A aircraft. Data obtained include on- and off-surface flow visualization and static pressure measurements on the forebody. Comparisons of similar results are made between the two aircraft where possible. The forebody shapes of the two aircraft are different and the X-29A forebody flow is affected by the addition of nose strakes and a flight test noseboom. The forebody flow field of the F-18 HARV is fairly symmetric at zero sideslip and has distinct, well-defined vortices. The X-29A forebody vortices are more diffuse and are sometimes asymmetric at zero sideslip. These asymmetries correlate with observed zero-sideslip aircraft yawing moments.

  8. Flurpiridaz F 18 PET: Phase II Safety and Clinical Comparison with SPECT Myocardial Perfusion Imaging for Detection of Coronary Artery Disease

    PubMed Central

    Berman, Daniel S.; Maddahi, Jamshid; Tamarappoo, B. K.; Czernin, Johannes; Taillefer, Raymond; Udelson, James E.; Gibson, C. Michael; Devine, Marybeth; Lazewatsky, Joel; Bhat, Gajanan; Washburn, Dana

    2015-01-01

    Objectives Phase II trial to assess flurpiridaz F 18 for safety and compare its diagnostic performance for PET myocardial perfusion imaging (MPI) to Tc-99m SPECT-MPI regarding image quality, interpretative certainty, defect magnitude and detection of coronary artery disease (CAD)(≥ 50% stenosis) on invasive coronary angiography (ICA). Background In preclinical and phase I studies, flurpiridaz F 18 has shown characteristics of an essentially ideal MPI tracer. Methods 143 patients from 21 centers underwent rest-stress PET and Tc-99m SPECT-MPI. Eighty-six patients underwent ICA, and 39 had low-likelihood of CAD. Images were scored by 3 independent, blinded readers. Results A higher % of images were rated as excellent/good on PET vs. SPECT on stress (99.2% vs. 88.5%, p<0.01) and rest (96.9% vs. 66.4, p<0.01) images. Diagnostic certainty of interpretation (% cases with definitely abnormal/normal interpretation) was higher for PET vs. SPECT (90.8% vs. 70.9%, p<0.01). In 86 patients who underwent ICA, sensitivity of PET was higher than SPECT [78.8% vs. 61.5%, respectively (p=0.02)]. Specificity was not significantly different (PET:76.5% vs. SPECT:73.5%). Receiver operating characteristic curve area was 0.82±0.05 for PET and 0.70±0.06 for SPECT (p=0.04). Normalcy rate was 89.7% with PET and 97.4% with SPECT (p=NS). In patients with CAD on ICA, the magnitude of reversible defects was greater with PET than SPECT (p=0.008). Extensive safety assessment revealed that flurpiridaz F 18 was safe in this cohort. Conclusions In this Phase 2 trial, PET MPI using flurpiridaz F 18 was safe and superior to SPECT MPI for image quality, interpretative certainty, and overall CAD diagnosis. PMID:23265345

  9. F-18 fluoride positron emission tomography/computed tomography in the diagnosis of avascular necrosis of the femoral head: Comparison with magnetic resonance imaging

    PubMed Central

    Gayana, Shankaramurthy; Bhattacharya, Anish; Sen, Ramesh Kumar; Singh, Paramjeet; Prakash, Mahesh; Mittal, Bhagwant Rai

    2016-01-01

    Objective: Femoral head avascular necrosis (FHAVN) is one of the increasingly common causes of musculoskeletal disability and poses a major diagnostic and therapeutic challenge. Although radiography, scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI) have been widely used in the diagnosis of FHAVN, positron emission tomography (PET) has recently been evaluated to assess vascularity of the femoral head. In this study, the authors compared F-18 fluoride PET/CT with MRI in the initial diagnosis of FHAVN. Patients and Methods: We prospectively studied 51 consecutive patients with a high clinical suspicion of FHAVN. All patients underwent MRI and F-18 fluoride PET/CT, the time interval between the two scans being 4–10 (mean 8) days. Two nuclear medicine physicians blinded to the MRI report read the PET/CT scans. Clinical assessment was also done. Final diagnoses were made by surgical pathology or clinical and radiologic follow-up. Results: A final diagnosis of avascular necrosis (AVN) was made in 40 patients. MRI was 96.5% sensitive, 100% specific, and 98.03% accurate while PET/CT was 100% sensitive, specific, and accurate in diagnosing FHAVN. The agreement between the two imaging modalities for the diagnosis of AVN was 96.07%. Conclusion: F-18 fluoride PET/CT showed good agreement with MRI in the initial diagnosis of FHAVN and can be better than MRI in detecting early disease. PMID:26917886

  10. Is γ-Ray Emission from Novae Affected by Interference Effects in the F18(p,α)O15 Reaction?

    NASA Astrophysics Data System (ADS)

    Laird, A. M.; Parikh, A.; Murphy, A. St. J.; Wimmer, K.; Chen, A. A.; Deibel, C. M.; Faestermann, T.; Fox, S. P.; Fulton, B. R.; Hertenberger, R.; Irvine, D.; José, J.; Longland, R.; Mountford, D. J.; Sambrook, B.; Seiler, D.; Wirth, H.-F.

    2013-01-01

    The F18(p,α)O15 reaction rate is crucial for constraining model predictions of the γ-ray observable radioisotope F18 produced in novae. The determination of this rate is challenging due to particular features of the level scheme of the compound nucleus, Ne19, which result in interference effects potentially playing a significant role. The dominant uncertainty in this rate arises from interference between Jπ=3/2+ states near the proton threshold (Sp=6.411MeV) and a broad Jπ=3/2+ state at 665 keV above threshold. This unknown interference term results in up to a factor of 40 uncertainty in the astrophysical S-factor at nova temperatures. Here we report a new measurement of states in this energy region using the F19(He3,t)Ne19 reaction. In stark contrast to previous assumptions we find at least 3 resonances between the proton threshold and Ecm=50keV, all with different angular distributions. None of these are consistent with Jπ=3/2+ angular distributions. We find that the main uncertainty now arises from the unknown proton width of the 48 keV resonance, not from possible interference effects. Hydrodynamic nova model calculations performed indicate that this unknown width affects F18 production by at least a factor of two in the model considered.

  11. Predictors of Pathologic Outcome of Focal FDG Uptake in the Parotid Gland Identified on Whole Body FDG PET Imaging

    PubMed Central

    Mabray, Marc C.; Behr, Spencer C.; Naeger, David M.; Flavell, Robert R.; Glastonbury, Christine M.

    2015-01-01

    Purpose To test whether patient's primary malignancy type and presence of FDG-avid cervical lymph node(s) are predictors of pathologic outcome of incidental focal FDG-avid parotid lesions. Basic Procedures Retrospective cohort study of pathologically proven incidental cases. Main Findings Focal parotid FDG uptake in the setting of head and neck cancer/melanoma(OR=24.6,p<0.01), lymphoma(OR=7.2,p=0.02), or FDG-avid cervical lymph node(s)(OR=3.6,p=0.07) has a higher odds of representing metastases. No malignant primary parotid tumors were incidentally discovered. Principal Conclusions In patients with head and neck cancer/melanoma, lymphoma, or FDG-avid cervical lymph node(s) there was a higher odds that focal parotid FDG uptake was a metastasis. PMID:26324219

  12. FDG PET/CT findings of common bile duct tuberculosis.

    PubMed

    Dong, Aisheng; Wang, Yang; Gong, Jing; Zuo, Changjing

    2014-01-01

    Common bile duct (CBD) tuberculosis is rare. A 39-year-old woman was referred because of a 5-month history of abdominal pain. Abdominal enhanced MRI and CT showed dilatation of the distal CBD with irregularly thickened wall. Enhanced CT revealed enlarged retroperitoneal lymph nodes. FDG PET/CT showed increased FDG uptake of the CBD lesion and several retroperitoneal lymph nodes with slight FDG uptake. CBD cholangiocarcinoma with retroperitoneal lymph node metastasis was suspected. CBD tuberculosis was confirmed by endoluminal biopsy. Tuberculosis should be considered in the differential diagnosis of abnormal biliary FDG accumulation, particularly in tuberculosis endemic areas.

  13. Isolation rearing significantly perturbs brain metabolism in the thalamus and hippocampus.

    PubMed

    Bonab, A A; Fricchione, J G; Gorantla, S; Vitalo, A G; Auster, M E; Levine, S J; Scichilone, J M; Hegde, M; Foote, W; Fricchione, G L; Denninger, J W; Yarmush, D M; Fischman, A J; Yarmush, M L; Levine, J B

    2012-10-25

    Psychosocial neglect during childhood severely impairs both behavioral and physical health. The isolation rearing model in rodents has been employed by our group and others to study this clinical problem at a basic level. We previously showed that immediate early gene (IEG) expression in the hippocampus and medial prefrontal cortex (mPFC) is decreased in isolation-reared (IR) compared to group-reared (GR) rats. In the current study, we sought to evaluate: (1) whether these changes in IEG expression would be detected by the measurement of brain glucose metabolism using positron emission tomography (PET) with fluorodeoxyglucose (FDG) and (2) whether PET FDG could illuminate other brain regions with different glucose metabolism in IR compared to GR rats. We found that there were significant differences in FDG uptake in the hippocampus that were consistent with our findings for IEG expression (decreased mean FDG uptake in IR rats). In contrast, in the mPFC, the FDG uptake between IR and GR rats did not differ. Finally, we found decreased mean FDG uptake in the thalamus of the IR rats, a region we had not previously examined. The results suggest that PET FDG has the potential to be utilized as a biomarker of molecular changes in the hippocampus. Further, the differences found in thalamic brain FDG uptake suggest that further investigation of this region at the molecular and cellular levels may provide an important insight into the neurobiological basis of the adverse clinical outcomes found in children exposed to psychosocial deprivation.

  14. Organizing Hematoma of the Maxillary Sinus Mimicking Malignancy Diagnosed by Fluorodeoxyglucose Positron-Emission Tomography (FDG PET/CT): A Case Report

    PubMed Central

    Park, Yong Kyun; Kim, Kyung Soo

    2015-01-01

    Organizing hematoma of the paranasal sinuses is a diagnostic dilemma clinically and radiographically, mimicking benign or malignant neoplastic processes. Although the diagnostic rate of this disease has increased as characteristic imaging findings are somewhat elucidated, endoscopic examination, preoperative biopsy, and computed tomography (CT) imaging do not give helpful information in differentiating these lesions from malignant neoplastic processes. A 55-year-old man presented with a 4-month history of recurrent nasal bleeding. He also complained of a left-sided nasal obstruction. CT findings were highly suggestive of a malignant tumor of the maxillary sinus. However, based on fluorodeoxyglucose F18 positron-emission tomography (PET/CT) and magnetic resonance imaging (MRI), the provisional diagnosis of benign tumor rather than malignancy was made. Complete resection of the mass was achieved by simple transnasal endoscopic surgery using the Caldwell-Luc approach. Organizing hematoma of the maxillary sinus was diagnosed by histopathologic evaluation. The clinical, radiological, and histopathologic findings of the patient are presented. In this report, we have presented 18FDG-PET findings of organized hematoma of the maxillary sinus (OHMS) that showed an increased FDG uptake in the peripheral rim of the mass with central photopenia. To our knowledge, this is the first case report in the literature reporting FDG-PET/CT findings of OHMS. Careful interpretation of metabolic (FDG-PET/CT) and anatomic (CT and MRI) images should be performed to accurately characterize the expansile lesion of the maxillary sinus in order to increase specificity and reduce equivocal findings significantly. PMID:26587203

  15. Cerebral metabolic rate for glucose during the first six months of life: an FDG positron emission tomography study.

    PubMed Central

    Kinnala, A.; Suhonen-Polvi, H.; Aärimaa, T.; Kero, P.; Korvenranta, H.; Ruotsalainen, U.; Bergman, J.; Haaparanta, M.; Solin, O.; Nuutila, P.; Wegelius, U.

    1996-01-01

    AIM: To measure the local cerebral metabolic rate for glucose (LCMRGlc) in neonatal brains during maturation using positron emission tomography (PET) and 2-[18F]fluoro-2-deoxy-D-glucose (FDG). METHODS: Twenty infants were studied using PET during the neonatal period. The postconceptional age ranged from 32.7 to 60.3 weeks. All infants had normal neurodevelopment and were normoglycaemic. The development of the infants was carefully evaluated (follow up 12-36 months) clinically, and by using a method based on Gesell Amatruda's developmental diagnosis. LCMRGlc was quantitated using PET derived from FDG kinetics and calculated in the whole brain and for regional brain structures. RESULTS: LCMRGlc for various cortical brain regions and the basal ganglia was low at birth (from 4 to 16 mumol/100 g/minute). In infants 2 months of age and younger LCMRGlc was highest in the sensorimotor cortex, thalamus, and brain stem. By 5 months, LCMRGlc had increased in the frontal, parietal, temporal, occipital and cerebellar cortical regions. In general, the whole brain LCMRGlc correlated with postconceptional age (r = 0.90; P < 0.001). The change in the glucose metabolic pattern observed in the neonatal brain reflects the functional maturation of these brain regions. CONCLUSION: These findings show that LCMRGlc in infants increases with maturation. Accordingly, when LCMRGlc is measured during infancy, the postconceptional age has to be taken into account when interpretating the results. Images Figure 1 PMID:8777676

  16. Connectivity analysis of normal and mild cognitive impairment patients based on FDG and PiB-PET images.

    PubMed

    Son, Seong-Jin; Kim, Jonghoon; Seo, Jongbum; Lee, Jong-min; Park, Hyunjin

    2015-09-01

    Connectivity analysis allows researchers to explore interregional correlations, and thus is well suited for analysis of complex networks such as the brain. We applied whole brain connectivity analysis to assess the progression of Alzheimer's disease (AD). To detect early AD progression, we focused on distinguishing between normal control (NC) subjects and subjects with mild cognitive impairment (MCI). Fludeoxyglucose (FDG) and Pittsburgh compound B (PiB)-positron emission tomography (PET) were acquired for 75 participants. A graph network was implemented using correlation matrices. Correlation matrices of FDG and PiB-PET were combined into one matrix using a novel method. Group-wise differences between NC and MCI patients were assessed using clustering coefficients, characteristic path lengths, and betweenness centrality using various correlation matrices. Using connectivity analysis, this study identified important regions differentially affected by AD progression.

  17. Pulmonary intravascular lymphoma detected by FDG PET-CT: a case report.

    PubMed

    Kohan, A A; Paganini, L; Biedak, P; Arma, J I; Dalurzo, M C L; Garcia-Monaco, R D

    2013-01-01

    Intravascular lymphoma is a rare subtype of extranodal Non-Hodgkin's lymphoma. Its prognosis is poor in a high percentage of cases due to its insidious appearance and low clinical suspicion. Its diagnosis is usually only reached after an autopsy. It may affect different organs as a whole or only one organ. It is extremely rare that the lung is the only damaged organ. Its diagnosis depends of the clinician's suspicion and proper evaluation with imaging studies as well as correct selection of the organ to be biopsied. When detected on time, the treatment of choice is a combination of a series of chemotherapy associated to a monoclonal antibody (anti-CD20). We present the case of a male patient who underwent a positron emission tomography-computed tomography with 2-[F-18]-fluoro-2 deoxy-D-glucose (FDG) due to symptoms suggestive of a lymphoproliferative disease with no clear structural abnormalities. The images led to a diagnosis of pulmonary intravascular large B cell lymphoma.

  18. Reduced 123I Ioflupane Binding in Bilateral Diabetic Chorea: Findings With 18F FDG PET, 99mTc ECD SPECT, and 123I MIBG Scintigraphy.

    PubMed

    Sato, Kenichiro; Hida, Ayumi; Kameyama, Masashi; Morooka, Miyako; Takeuchi, Sousuke

    2016-06-01

    We report a 64-year-old man with diabetic chorea whom we investigated with dopamine transporter SPECT, F FDG PET, Tc ethylcysteinate dimer (ECD) SPECT, and I metaiodobenzylguanidine (MIBG) scintigraphy. Dopamine transporter SPECT revealed reduced I ioflupane binding in the bilateral striatum. F FDG PET showed metabolic dysfunction in the bilateral striatum, as shown in earlier studies. Tc ECD SPECT revealed reduced brain perfusion in the bilateral caudate nucleus and putamen. I MIBG scintigraphy revealed no cardiac sympathetic nerve dysfunction. Our case suggests a possible nigrostriatal presynaptic dopaminergic involvement in diabetic chorea.

  19. Medial thalamic 18-FDG uptake following inescapable shock correlates with subsequent learned helpless behavior

    SciTech Connect

    Mirrione,M.M.; Mirrione, M.M.; Schulz, D.; Dewey, S.L.; Henn, F.A.

    2009-12-06

    The learned helplessness paradigm has been repeatedly shown to correlate with neurobiological aspects of depression in humans. In this model, rodents are exposed inescapable foot-shock in order to reveal susceptibility to escape deficit, defined as 'learned helplessness' (LH). Few methods are available to probe the neurobiological aspects underlying the differences in susceptibility in the living animal, thus far being limited to studies examining regional neurochemical changes with microdialysis. With the widespread implementation of small animal neuroimaging methods, including positron emission tomography (PET), it is now possible to explore the living brain on a systems level to define regional changes that may correlate with vulnerability to stress. In this study, 12 wild type Sprague-Dawley rats were exposed to 40 minutes of inescapable foot-shock followed by metabolic imaging using 2-deoxy-2[{sup 18}F]fluoro-D-glucose (18-FDG) 1 hour later. The escape test was performed on these rats 48 hours later (to accommodate radiotracer decay), where they were given the opportunity to press a lever to shut off the shock. A region of interest (ROI) analysis was used to investigate potential correlations (Pearson Regression Coefficients) between regional 18-FDG uptake following inescapable shock and subsequent learned helpless behavior (time to finish the test; number of successful lever presses within 20 seconds of shock onset). ROI analysis revealed a significant positive correlation between time to finish and 18-FDG uptake, and a negative correlation between lever presses and uptake, in the medial thalamic area (p=0.033, p=0.036). This ROI included the paraventricular thalamus, mediodorsal thalamus, and the habenula. In an effort to account for possible spillover artifact, the posterior thalamic area (including ventral medial and lateral portions) was also evaluated but did not reveal significant correlations (p=0.870, p=0.897). No other significant correlations were

  20. Global emission estimates and radiative impact of C4F10, C5F12, C6F14, C7F16 and C8F18

    NASA Astrophysics Data System (ADS)

    Ivy, D. J.; Rigby, M.; Baasandorj, M.; Burkholder, J. B.; Prinn, R. G.

    2012-05-01

    Global emission estimates based on new atmospheric observations are presented for the acylic high molecular weight perfluorocarbons (PFCs): decafluorobutane (C4F10), dodecafluoropentane (C5F12), tetradecafluorohexane (C6F14), hexadecafluoroheptane (C7F16) and octadecafluorooctane (C8F18). Emissions are estimated using a 3-dimensional chemical transport model and an inverse method that includes a growth constraint on emissions. The observations used in the inversion are based on newly measured archived air samples that cover a 39-yr period, from 1973 to 2011, and include 36 Northern Hemispheric and 46 Southern Hemispheric samples (Ivy et al., 2012). The derived emission estimates show that global emission rates were largest in the 1980s and 1990s for C4F10 and C5F12, and in the 1990s for C6F14,C7F16 and C8F18. After a subsequent decline, emissions have remained relatively stable, within 20%, for the last 5 yr. Bottom-up emission estimates are available from the Emission Database for Global Atmospheric Research version 4.2 (EDGARv4.2) for C4F10, C5F12, C6F14 and C7F16, and inventories of C4F10, C5F12 andC6F14 are reported to the United Nations' Framework Convention on Climate Change (UNFCCC) by Annex 1 countries that have ratified the Kyoto Protocol. The atmospheric measurement based emission estimates are 20 times larger than EDGARv4.2 for C4F10 and over three orders of magnitude for C5F12. The derived emission estimates for C6F14 largely agree with the bottom-up estimates from EDGARv4.2. Moreover, the C7F16 emission estimates are comparable to those of EDGARv4.2 at their peak in the 1990s, albeit significant underestimation for the other time periods. There are no bottom-up emission estimates for C8F18, thus the emission rates reported here are the first for C8F18. The reported inventories for C4F10, C5F12 and C6F14 to UNFCCC are five to ten times lower than those estimated in this study. In addition, we present measured infrared absorption spectra for C7F16 and C8

  1. Global emission estimates and radiative impact of C4F10, C5F12, C6F14, C7F16 and C8F18

    NASA Astrophysics Data System (ADS)

    Ivy, D. J.; Rigby, M.; Baasandorj, M.; Burkholder, J. B.; Prinn, R. G.

    2012-08-01

    Global emission estimates based on new atmospheric observations are presented for the acylic high molecular weight perfluorocarbons (PFCs): decafluorobutane (C4F10), dodecafluoropentane (C5F12), tetradecafluorohexane (C6F14), hexadecafluoroheptane (C7F16) and octadecafluorooctane (C8F18). Emissions are estimated using a 3-dimensional chemical transport model and an inverse method that includes a growth constraint on emissions. The observations used in the inversion are based on newly measured archived air samples that cover a 39-yr period, from 1973 to 2011, and include 36 Northern Hemispheric and 46 Southern Hemispheric samples. The derived emission estimates show that global emission rates were largest in the 1980s and 1990s for C4F10 and C5F12, and in the 1990s for C6F14, C7F16 and C8F18. After a subsequent decline, emissions have remained relatively stable, within 20%, for the last 5 yr. Bottom-up emission estimates are available from the Emission Database for Global Atmospheric Research version 4.2 (EDGARv4.2) for C4F10, C5F12, C6F14 and C7F16, and inventories of C4F10, C5F12 and C6F14 are reported to the United Nations' Framework Convention on Climate Change (UNFCCC) by Annex 1 countries that have ratified the Kyoto Protocol. The atmospheric measurement-based emission estimates are 20 times larger than EDGARv4.2 for C4F10 and over three orders of magnitude larger for C5F12 (with 2008 EDGARv4.2 estimates for C5F12 at 9.6 kg yr-1, as compared to 67±53 t yr-1 as derived in this study). The derived emission estimates for C6F14 largely agree with the bottom-up estimates from EDGARv4.2. Moreover, the C7F16 emission estimates are comparable to those of EDGARv4.2 at their peak in the 1990s, albeit significant underestimation for the other time periods. There are no bottom-up emission estimates for C8F18, thus the emission rates reported here are the first for C8F18. The reported inventories for C4F10, C5F12 and C6F14 to UNFCCC are five to ten times lower than those

  2. Brain PET metabolic abnormalities in a case of varicella-zoster virus encephalitis.

    PubMed

    Coiffard, Benjamin; Guedj, Eric; Daumas, Aurélie; Leveque, Pierre; Villani, Patrick

    2014-09-01

    The role of brain 18F-FDG PET in the diagnostic evaluation of encephalitis has been recently suggested, especially in limbic encephalitis, but descriptions are mainly limited to small case reports. However, the evaluation of cerebral metabolism by 18F-FDG PET has never been described for varicella-zoster virus encephalitis. We report the first case of varicella-zoster virus encephalitis in which 18F-FDG PET revealed brain metabolic abnormalities. Brain metabolic PET imaging was analyzed by comparing the patient's brain 18F-FDG PET scans to that of 12 healthy subjects. Compared with healthy subjects, significant hypometabolism and hypermetabolism were found and evolved over time with treatment.

  3. The mediational effects of FDG hypometabolism on the association between cerebrospinal fluid biomarkers and neurocognitive function.

    PubMed

    Dowling, N Maritza; Johnson, Sterling C; Gleason, Carey E; Jagust, William J

    2015-01-15

    Positive cerebrospinal fluid (CSF) biomarkers of tau and amyloid beta42 suggest possible active underlying Alzheimer's disease (AD) including neurometabolic dysfunction and neurodegeneration leading to eventual cognitive decline. But the temporal relationship between CSF, imaging markers of neural function, and cognition has not been described. Using a statistical mediation model, we examined relationships between cerebrospinal fluid (CSF) analytes (hyperphosphorylated tau (p-Tau(181p)), β-amyloid peptides 1-42 (Aβ(1-42)), total tau (t-Tau), and their ratios); change in cognitive function; and change in [18F]fluorodeoxyglucose (FDG) uptake using positron emission tomography (PET). We hypothesized that a) abnormal CSF protein values at baseline, result in cognitive declines by decreasing neuronal glucose metabolism across time, and b) the role of altered glucose metabolism in the assumed causal chain varies by brain region and the nature of CSF protein alteration. Data from 412 individuals participating in Alzheimer's Disease Neuroimaging (ADNI) cohort studies were included in analyses. At baseline, individuals were cognitively normal (N = 82), or impaired: 241 with mild cognitive impairment, and 89 with Alzheimer's disease. A parallel-process latent growth curve model was used to test mediational effects of changes in regional FDG-PET uptake over time in relation to baseline CSF biomarkers and changes in cognition, measured with the 13-item Alzheimer Disease's Assessment Scale-cognitive subscale (ADAS-Cog). Findings suggested a causal sequence of events; specifically, FDG hypometabolism acted as a mediator between antecedent CSF biomarker alterations and subsequent cognitive impairment. Higher baseline concentrations of t-Tau, and p-Tau(181p) were more predictive of decline in cerebral glucose metabolism than lower baseline concentrations of Aβ(1-42). FDG-PET changes appeared to mediate t-Tau or t-Tau/Aβ(1-42)-associated cognitive change across all brain

  4. Flight test maneuvers for closed loop lateral-directional modeling of the F-18 High Alpha Research Vehicle (HARV) using forebody strakes

    NASA Technical Reports Server (NTRS)

    Morelli, E. A.

    1996-01-01

    Flight test maneuvers are specified for the F-18 High Alpha Research Vehicle (HARV). The maneuvers were designed for closed loop parameter identification purposes, specifically for lateral linear model parameter estimation at 30, 45, and 60 degrees angle of attack, using the Actuated Nose Strakes for Enhanced Rolling (ANSER) control law in Strake (S) model and Strake/Thrust Vectoring (STV) mode. Each maneuver is to be realized by applying square wave inputs to specific pilot station controls using the On-Board Excitation System (OBES). Maneuver descriptions and complete specification of the time/amplitude points defining each input are included, along with plots of the input time histories.

  5. F-18 High Alpha Research Vehicle (HARV) parameter identification flight test maneuvers for optimal input design validation and lateral control effectiveness

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    1995-01-01

    Flight test maneuvers are specified for the F-18 High Alpha Research Vehicle (HARV). The maneuvers were designed for open loop parameter identification purposes, specifically for optimal input design validation at 5 degrees angle of attack, identification of individual strake effectiveness at 40 and 50 degrees angle of attack, and study of lateral dynamics and lateral control effectiveness at 40 and 50 degrees angle of attack. Each maneuver is to be realized by applying square wave inputs to specific control effectors using the On-Board Excitation System (OBES). Maneuver descriptions and complete specifications of the time/amplitude points define each input are included, along with plots of the input time histories.

  6. Development of F-18 Labeled Radiotracers for PET Imaging of Brain Alpha-1 Noradrenergic Receptors: Potential PTSD Vulnerability and Diagnostic Biomarkers

    DTIC Science & Technology

    2012-09-01

    SERT) Dopamine: D1, D2, D3, D4, and D5 Dopamine uptake transporter (DAT) Histamine : H1, H2, and H3 Acetylcholine: M1, M2, M3, M4, and M5...Cimetidine H3 [3H]alpha-methylhistamine Histamine HISTAMINE H4 [3H] Histamine Clozapine M1 [3H]QNB Atropine M2 [3H]QNB Atropine M3...Dopamine: D1, D2, D3, D4, and D5 •Dopamine uptake transporter (DAT) • Histamine : H1, H2, and H3 •Acetylcholine: M1, M2, M3, M4, and M5 •Endogenous

  7. FDG-PET Assessment of the Effect of Head and Neck Radiotherapy on Parotid Gland Glucose Metabolism

    SciTech Connect

    Roach, Michael C.; Turkington, Timothy G.; Higgins, Kristin A.; Hawk, Thomas C.; Hoang, Jenny K.; Brizel, David M.

    2012-01-01

    Purpose: Functional imaging with [F-18]-fluorodeoxyglucose positron emission tomography (FDG-PET) provides the opportunity to define the physiology of the major salivary glands before and after radiation therapy. The goal of this retrospective study was to identify the radiation dose-response relationship of parotid gland glucose metabolism in patients with head and neck squamous cell carcinoma (HNSCC). Materials and Methods: Forty-nine adults with HNSCC were identified who had curative intent intensity-modulated radiation therapy (IMRT) and FDG-PET imaging before and after treatment. Using a graphical user interface, contours were delineated for the parotid glands on axial CT slices while all authors were blinded to paired PET slices. Average and maximal standard uptake values (SUV) were measured within these anatomic regions. Changes in SUV and volume after radiation therapy were correlated with parotid gland dose-volume histograms from IMRT plans. Results: The average parotid gland volume was 30.7 mL and contracted 3.9 {+-} 1.9% with every increase of 10 Gy in mean dose (p = 0.04). However, within the first 3 months after treatment, there was a uniform reduction of 16.5% {+-} 7.3% regardless of dose. The average SUV{sub mean} of the glands was 1.63 {+-} 0.48 pretreatment and declined by 5.2% {+-} 2.5% for every increase of 10 Gy in mean dose (p = 0.04). The average SUV{sub max} was 4.07 {+-} 2.85 pretreatment and decreased in a sigmoid manner with mean dose. A threshold of 32 Gy for mean dose existed, after which SUV{sub max} declined rapidly. Conclusion: Radiation dose responses of the parotid glands can be measured by integrated CT/FDG-PET scans. Retrospective analysis showed sigmoidal declines in the maximum metabolism but linear declines in the average metabolism of the glands with dose. Future studies should correlate this decline in FDG uptake with saliva production to improve treatment planning.

  8. The Role of 18F-FDG PET/CT in the Evaluation of Gastric Cancer Recurrence

    PubMed Central

    Cayvarlı, Hakan; Bekiş, Recep; Akman, Tülay; Altun, Deniz

    2014-01-01

    Objective: F-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been widely used for staging, re-staging and for monitoring therapy-induced changes and response to therapy in patients with various types of cancer, but its utilization for gastric cancer has been limited. This study aimed to assess the diagnostic performance of 18F-FDG PET/CT for detecting recurrence in gastric cancer patients with radiologic or clinical suspicion of recurrence and its clinical impact on making decision. Methods: We performed a retrospective review of 130 consecutive patients who underwent PET/CT scans for post-treatment surveillance of gastric cancer between January 2008 and March 2012. The mean time between the initial diagnosis of gastric cancer and PET/CT studies was 44 weeks with a median of 18 weeks. The number and site of positive FDG uptake were analyzed and correlated with the final diagnosis by calculating the diagnostic values. We evaluated the diagnostic accuracy of PET/CT for detecting the recurrence in terms of whether or not histology had been SRC/musinous adenocarcinoma. The changes in the clinical management of patients were also evaluated according to the results of PET/CT. Results: Of all 130 patients, 91 patients were confirmed to have true recurrence. The sensitivity, specificity, positive predictive value, negative predictive value and the accuracy of PET/CT for diagnosing true recurrence on a per-person basis were 91.2%, 61.5%, 84.6%, 75.0% and 82.3% respectively. Final diagnoses were confirmed histopathologically in 59 (45.4%) of 130 patients and by clinical and radiological follow-up in the remaining 71 (54.6%) patients. In the subgroup with SRC/mucinous adenocarcinoma differentiation of the primary tumor, there was no statistically significant difference in terms of diagnostic accuracy of PET/CT on a per-person basis. In addition, PET/CT results changed the patients’ management in 20 (15%) cases. Conclusions: 18F-FDG

  9. Systemic Immune Response to Vaccination on FDG-PET/CT.

    PubMed

    Mingos, Mark; Howard, Stephanie; Giacalone, Nicholas; Kozono, David; Jacene, Heather

    2016-12-01

    A patient with newly diagnosed right lung cancer had transient (18)F-fluorodeoxyglucose (FDG)-avid left axillary lymph nodes and intense splenic FDG uptake on positron emission tomography (PET)/computed tomography (CT). History revealed that the patient received a left-sided influenza vaccine 2-3 days before the examination. Although inflammatory FDG uptake in ipsilateral axillary nodes is reported, to our knowledge, this is the first report of visualization of the systemic immune response in the spleen related to the influenza vaccination on FDG-PET/CT. The history, splenic uptake and time course on serial FDG-PET/CT helped to avoid a false-positive interpretation for progressing lung cancer and alteration of the radiation therapy plan.

  10. Stereotactic Comparison Study of 18F-Alfatide and 18F-FDG PET Imaging in an LLC Tumor-Bearing C57BL/6 Mouse Model

    PubMed Central

    Wei, Yu-Chun; Gao, Yongsheng; Zhang, Jianbo; Fu, Zheng; Zheng, Jinsong; Liu, Ning; Hu, Xudong; Hou, Wenhong; Yu, Jinming; Yuan, Shuanghu

    2016-01-01

    This study aimed to stereotactically compare the PET imaging performance of 18F-Alfatide (18F-ALF-NOTA-PRGD2, denoted as 18F-Alfatide) and 18F-fluorodeoxyglucose (FDG) and immunohistochemistry (IHC) staining in Lewis lung carcinoma (LLC) tumor-bearing C57BL/6 mouse model. 18F-FDG standard uptake values (SUVs) were higher than 18F-Alfatide SUVs in tumors, most of the normal tissues and organs except for the bladder. Tumor-to-brain, tumor-to-lung, and tumor-to-heart ratios of 18F-Alfatide PET were significantly higher than those of 18F-FDG PET (P < 0.001). The spatial heterogeneity of the tumors was detected, and the tracer accumulation enhanced from the outer layer to the inner layer consistently using the two tracers. The parameters of the tumors were significantly correlated with each other between 18F-FDG SUV and GLUT-1 (R = 0.895, P < 0.001), 18F-Alfatide SUV and αvβ3 (R = 0.595, P = 0.019), 18F-FDG SUV and 18F-Alfatide SUV (R = 0.917, P < 0.001), and GLUT-1 and αvβ3 (R = 0.637, P = 0.011). Therefore, 18F-Alfatide PET may be an effective tracer for tumor detection, spatial heterogeneity imaging and an alternative supplement to 18F-FDG PET, particularly for patients with enhanced characteristics in the brain, chest tumors or diabetes, meriting further study. PMID:27350554

  11. Longitudinal Characterization of [18F]-FDG and [18F]-AV45 Uptake in the Double Transgenic TASTPM Mouse Model

    PubMed Central

    Waldron, Ann-Marie; wyffels, Leonie; Verhaeghe, Jeroen; Richardson, Jill C.; Schmidt, Mark; Stroobants, Sigrid; Langlois, Xavier; Staelens, Steven

    2016-01-01

    We aimed to monitor the timing of amyloid-β deposition in relation to changes in brain function using in vivo imaging with [18F]-AV45 and [18F]-FDG in a mouse model of Alzheimer’s disease. TASTPM transgenic mice and wild-type controls were scanned longitudinally with [18F]-AV45 and [18F]-FDG before (3 months of age) and at multiple time points after the onset of amyloid deposition (6, 9, 12, and 15 months of age). As expected with increasing amyloidosis, TASTPM mice demonstrated progressive age-dependent increases in [18F]-AV45 uptake that were significantly higher than for WT from 9 months onwards and correlated to ex vivo measures of amyloid burden. The metabolism of [18F]-AV45 produces several brain penetrant radiometabolites and normalization to a reference region helps to negate this non-specific binding and improve the sensitivity of [18F]-AV45. The observed trajectory of [18F]-FDG alterations deviated from our proposed hypothesis of gradual decreases with worsening amyloidosis. While [18F]-FDG uptake in TASTPM mice was significantly lower than that of WT at 9 months, reduced [18F]-FDG was not associated with aging in TASTPM mice. Moreover, [18F]-FDG uptake did not correlate to measures of ex vivo amyloid burden. Our findings suggest that while amyloid-β is sufficient to induce hypometabolism, these pathologies are not linked in a dose-dependent manner in TASTPM mice. PMID:27911309

  12. Challenges and Approaches to Quantitative Therapy Response Assessment in Glioblastoma Multiforme Using the Novel Apoptosis Positron Emission Tomography Tracer F-18 ML-10.

    PubMed

    Oborski, Matthew J; Laymon, Charles M; Qian, Yongxian; Lieberman, Frank S; Nelson, Arden D; Mountz, James M

    2014-02-01

    Evaluation of cancer-therapy efficacy at early time points is necessary for realizing the goal of delivering maximally effective treatment. Molecular imaging with carefully selected tracers and methodologies can provide the means for realizing this ability. Many therapies are aimed at inducing apoptosis in malignant tissue; thus, the ability to quantify apoptosis in vivo may be a fruitful approach. Apoptosis rate changes occur on a fast time scale, potentially allowing correspondingly rapid decisions regarding therapy value. However, quantification of tissue status based on apoptosis imaging is complicated by this time scale and by the spatial heterogeneity of the process. Using the positron emission tomography (PET) tracer 2-(5-fluoro-pentyl)-2-methyl-malonic acid (F-18 ML-10), we present methods of voxelwise analysis yielding quantitative measures of apoptosis changes, parametric apoptosis change images, and graphical representation of apoptotic features. A method of deformable registration to account for anatomic changes between scan time points is also demonstrated. Overall apoptotic rates deduced from imaging depend on tumor density and the specific rate of apoptosis, a situation resulting in an ambiguity in the source of observed image-based changes. The ambiguity may be resolved through multimodality imaging. An example of intracellular sodium magnetic resonance imaging coupled with F-18 ML-10 PET is provided.

  13. Multiaxis Thrust-Vectoring Characteristics of a Model Representative of the F-18 High-Alpha Research Vehicle at Angles of Attack From 0 deg to 70 deg

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Capone, Francis J.

    1995-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the multiaxis thrust-vectoring characteristics of the F-18 High-Alpha Research Vehicle (HARV). A wingtip supported, partially metric, 0.10-scale jet-effects model of an F-18 prototype aircraft was modified with hardware to simulate the thrust-vectoring control system of the HARV. Testing was conducted at free-stream Mach numbers ranging from 0.30 to 0.70, at angles of attack from O' to 70', and at nozzle pressure ratios from 1.0 to approximately 5.0. Results indicate that the thrust-vectoring control system of the HARV can successfully generate multiaxis thrust-vectoring forces and moments. During vectoring, resultant thrust vector angles were always less than the corresponding geometric vane deflection angle and were accompanied by large thrust losses. Significant external flow effects that were dependent on Mach number and angle of attack were noted during vectoring operation. Comparisons of the aerodynamic and propulsive control capabilities of the HARV configuration indicate that substantial gains in controllability are provided by the multiaxis thrust-vectoring control system.

  14. F-18 high alpha research vehicle surface pressures: Initial in-flight results and correlation with flow visualization and wind-tunnel data

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Banks, Daniel W.; Richwine, David M.

    1990-01-01

    Pressure distributions measured on the forebody and the leading-edge extensions (LEX's) of the NASA F-18 high alpha research vehicle (HARV) were reported at 10 and 50 degree angles of attack and at Mach 0.20 to 0.60. The results were correlated with HARV flow visualization and 6-percent scale F-18 wind-tunnel-model test results. The general trend in the data from the forebody was for the maximum suction pressure peaks to first appear at an angle of attack (alpha) of approximately 19 degrees and increase in magnitude with angle of attack. The LEX pressure distribution general trend was the inward progression and increase in magnitude of the maximum suction peaks up to vortex core breakdown and then the decrease and general flattening of the pressure distribution beyond that. No significant effect of Mach number was noted for the forebody results. However, a substantial compressibility effect on the LEX's resulted in a significant reduction in vortex-induced suction pressure as Mach number increased. The forebody primary and the LEX secondary vortex separation lines, from surface flow visualization, correlated well with the end of pressure recovery, leeward and windward, respectively, of maximum suction pressure peaks. The flight to wind-tunnel correlations were generally good with some exceptions.

  15. Single-scan dual-tracer FLT+FDG PET tumor characterization

    NASA Astrophysics Data System (ADS)

    Kadrmas, Dan J.; Rust, Thomas C.; Hoffman, John M.

    2013-02-01

    five patients with primary brain tumors where the data from separate scans of each tracer were combined to synthesize dual-tracer scans with known single-tracer components; results demonstrated similar dual-tracer signal recovery performance. We conclude that rapid dual-tracer FLT+FDG tumor imaging is feasible and can provide quantitative tumor imaging measures comparable to those from conventional separate-scan imaging.

  16. Brain PET in the Diagnosis of Alzheimer’s Disease

    PubMed Central

    Marcus, Charles; Mena, Esther; Subramaniam, Rathan M.

    2015-01-01

    Objectives The aim of this article was to review the current role of brain PET in the diagnosis of Alzheimer dementia. The characteristic patterns of glucose metabolism on brain FDG-PET can help in differentiating Alzheimer’s disease from other causes of dementia such as frontotemporal dementia and dementia of Lewy body. Amyloid brain PET may exclude significant amyloid deposition and thus Alzheimer’s disease in appropriate clinical setting. Conclusions FDG-PET and amyloid PET imaging are valuable in the assessment of patients with Alzheimer’s disease. PMID:25199063

  17. Effects of the −791(C→T) mutation in the promoter for tumor necrosis factor alpha on gene expression and resistance of Large White pigs to enterotoxigenic Escherichia coli F18

    PubMed Central

    Liu, Ying; Dai, Chaohui; Sun, Li; Zhu, Guoqiang; Wu, Shenglong; Bao, Wenbin

    2016-01-01

    Tumor necrosis factor alpha (TNF-α) plays an important role in the immune system. In this study, TNF-α expression was analyzed in 11 tissues of 8 piglets resistant to enterotoxigenic Escherichia coli (ETEC) F18 and 8 ETEC F18-susceptible piglets from the Large White breed. The expression levels of TNF-α were high in immune organs (spleen, lung, thymus, and lymph nodes). The levels were higher in ETEC F18-resistant piglets than in ETEC F18-susceptible piglets, with significant differences in spleen, kidney, thymus, lymph node, and duodenum (P < 0.05). The mutation TNF-α −791(C→T) and 3 genotypes (CC, CT, and TT) were identified. The TNF-α expression levels in the spleen, kidney, lymph nodes, and duodenum were significantly higher in the TT pigs than in the CC pigs (P < 0.05). Thus, TNF-α −791(C→T) has significant effects on mRNA expression and may regulate ETEC F18 resistance of weaning piglets. Therefore, the −791(C→T) mutation of the TNF-α gene could be considered an important potential genetic marker of ETEC F18 resistance. PMID:27408333

  18. Predictive and prognostic value of FDG-PET

    PubMed Central

    Oyen, Wim J.G.

    2008-01-01

    Abstract The predictive and prognostic value of fluorodeoxyglucose (FDG)-positron emission tomography (PET) in non-small-cell lung carcinoma, colorectal carcinoma and lymphoma is discussed. The degree of FDG uptake is of prognostic value at initial presentation, after induction treatment prior to resection and in the case of relapse of non-small cell lung cancer (NSCLC). In locally advanced and advanced stages of NSCLC, FDG-PET has been shown to be predictive for clinical outcome at an early stage of treatment. In colorectal carcinoma, limited studies are available on the prognostic value of FDG-PET, however, the technique appears to have great potential in monitoring the success of local ablative therapies soon after intervention and in the prediction and evaluation of response to radiotherapy, systemic therapy, and combinations thereof. The prognostic value of end-of treatment FDG-PET for FDG-avid lymphomas has been established, and the next step is to define how to use this information to optimize patient outcome. In Hodgkin's lymphoma, FDG-PET has a high negative predictive value, however, histological confirmation of positive findings should be sought where possible. For non-Hodgkin's lymphoma, the opposite applies. The newly published standardized guidelines for interpretation formulates specific criteria for visual interpretation and for defining PET positivity in the liver, spleen, lung, bone marrow and small residual lesions. The introduction of these guidelines should reduce variability among studies. Interim PET offers a reliable method for early prediction of long-term remission, however it should only be performed in prospective randomized controlled trials. Many of the diagnostic and management questions considered in this review are relevant to other tumour types. Further research in this field is of great importance, since it may lead to a change in the therapeutic concept of cancer. The preliminary findings call for systematic inclusion of FDG

  19. Clustering-Based Linear Least Square Fitting Method for Generation of Parametric Images in Dynamic FDG PET Studies

    PubMed Central

    Huang, Xinrui; Zhou, Yun; Bao, Shangliang; Huang, Sung-Cheng

    2007-01-01

    Parametric images generated from dynamic positron emission tomography (PET) studies are useful for presenting functional/biological information in the 3-dimensional space, but usually suffer from their high sensitivity to image noise. To improve the quality of these images, we proposed in this study a modified linear least square (LLS) fitting method named cLLS that incorporates a clustering-based spatial constraint for generation of parametric images from dynamic PET data of high noise levels. In this method, the combination of K-means and hierarchical cluster analysis was used to classify dynamic PET data. Compared with conventional LLS, cLLS can achieve high statistical reliability in the generated parametric images without incurring a high computational burden. The effectiveness of the method was demonstrated both with computer simulation and with a human brain dynamic FDG PET study. The cLLS method is expected to be useful for generation of parametric images from dynamic FDG PET study. PMID:18273393

  20. Increased fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) uptake in childhood CNS tumors is correlated with malignancy grade: a study with FDG positron emission tomography/magnetic resonance imaging coregistration and image fusion.

    PubMed

    Borgwardt, Lise; Højgaard, Liselotte; Carstensen, Henrik; Laursen, Henning; Nowak, Markus; Thomsen, Carsten; Schmiegelow, Kjeld

    2005-05-01

    PURPOSE Positron emission tomography (PET) has been used in grading of CNS tumors in adults, whereas studies of children have been limited. PATIENTS AND METHODS Nineteen boys and 19 girls (median age, 8 years) with primary CNS tumors were studied prospectively by fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) PET with (n = 16) or without (n = 22) H(2)(15)O-PET before therapy. Image processing included coregistration to magnetic resonance imaging (MRI) in all patients. The FDG uptake in tumors was semiquantitatively calculated by a region-of-interest-based tumor hotspot/brain index. Eight tumors without histologic confirmation were classified as WHO grade 1 based on location, MRI, and clinical course (22 to 42 months). Results Four grade 4 tumors had a mean index of 4.27 +/- 0.5, four grade 3 tumors had a mean index of 2.47 +/- 1.07, 10 grade 2 tumors had a mean index of 1.34 +/- 0.73, and eight of 12 grade 1 tumors had a mean index of -0.31 +/- 0.59. Eight patients with no histologic confirmation had a mean index of 1.04. For these 34 tumors, FDG uptake was positively correlated with malignancy grading (n = 34; r = 0.72; P < .01), as for the 26 histologically classified tumors (n = 26; r = 0.89; P < .01). The choroid plexus papilloma (n = 1) and the pilocytic astrocytomas (n = 3) had a mean index of 3.26 (n = 38; r = 0.57; P < .01). H(2)(15)O-uptake showed no correlation with malignancy. Digitally performed PET/MRI coregistration increased information on tumor characterization in 90% of cases. CONCLUSION FDG PET of the brain with MRI coregistration can be used to obtain a more specific diagnosis with respect to malignancy grading. Improved PET/MRI imaging of the benign hypermetabolic tumors is needed to optimize clinical use.

  1. F-18 high alpha research vehicle surface pressures - Initial in-flight results and correlation with flow visualization and wind-tunnel data

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Banks, Daniel W.; Richwine, David M.

    1990-01-01

    Flight tests with the NASA F-18 high-alpha research vehicle (HARV) have yielded pressure distributions at angles of attack from 10 to 50 deg, at Mach 0.23 to 0.6, at five fuselage forebody stations and three on the leading-edge extensions (LEXs). Correlations are made between these data and both previously obtained HARV flow visualizations and wind tunnel model test results. The general trend is one in which the forebody's maximum suction pressure peaks increase in magnitude, after their first appearance at alpha of about 19 deg, with increasing alpha. LEX pressure-distribution trends involve the inward progression of the maximum suction peaks, an increase in the magnitude of the maximum pressure peaks up to pressure core breakdown, and the decrease and general flattening of the pressure distribution beyond the LEX primary vortex breakdown.

  2. Quorum-sensing gene luxS regulates flagella expression and Shiga-like toxin production in F18ab Escherichia coli.

    PubMed

    Yang, Yang; Zhou, Mingxu; Hou, Huayan; Zhu, Jun; Yao, Fenghua; Zhang, Xinjun; Zhu, Xiaofang; Hardwidge, Philip R; Zhu, Guoqiang

    2014-06-01

    To investigate the effect of the luxS gene on the expression of virulence factors in Shiga-like toxin producing and verotoxin-producing Escherichia coli, the luxS gene from E. coli 107/86 (wild type, O139:H1:F18ab, Stx2e) was deleted. The successful deletion of luxS was confirmed by bioluminescence assays. The luxS deletion mutant exhibited changed flagella-related phenotypes, like impaired expression of flagella, decreased flagella motility, reduced biofilm formation, and reduced ability to induce pro-immunity response in host cells, which were restored after complementation with the intact luxS gene. The mutant strain also displayed attenuated production of Stx2e. This study provides new information to the crucial function of luxS in regulating Shiga-like toxin producing E. coli virulence.

  3. 18F-AFETP, 18F-FET, and 18F-FDG Imaging of Mouse DBT Gliomas

    PubMed Central

    Sai, Kiran Kumar Solingapuram; Huang, Chaofeng; Yuan, Liya; Zhou, Dong; Piwnica-Worms, David; Garbow, Joel R.; Engelbach, John A.; Mach, Robert H.; Rich, Keith M.; McConathy, Jonathan

    2013-01-01

    The goal of this study was to evaluate the 18F-labeled nonnatural amino acid (S)-2-amino-3-[1-(2-18F-fluoroethyl)-1H-[1,2,3]triazol-4-yl]propanoic acid (18F-AFETP) as a PET imaging agent for brain tumors and to compare its effectiveness with the more-established tracers O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) and 18F-FDG in a murine model of glioblastoma. The tracer 18F-AFETP is a structural analog of histidine and is a lead compound for imaging cationic amino acid transport, a relatively unexplored target for oncologic imaging. Methods 18F-AFETP was prepared using the click reaction. BALB/c mice with intracranially implanted delayed brain tumor (DBT) gliomas (n = 4) underwent biodistribution and dynamic small-animal PET imaging for 60 min after intravenous injection of 18F-AFETP. Tumor and brain uptake of 18F-AFETP were compared with those of 18F-FDG and 18F-FET through small-animal PET analyses. Results 18F-AFETP demonstrated focally increased uptake in tumors with good visualization. Peak tumor uptake occurred within 10 min of injection, with stable or gradual decrease over time. All 3 tracers demonstrated relatively high uptake in the DBTs throughout the study. At late time points (47.5–57.5 min after injection), the average standardized uptake value with 18F-FDG (1.9 ± 0.1) was significantly greater than with 18F-FET (1.1 ± 0.1) and 18F-AFETP (0.7 ± 0.2). The uptake also differed substantially in normal brain, with significant differences in the standardized uptake values at late times among 18F-FDG (1.5 ± 0.2), 18F-FET (0.5 ± 0.05), and 18F-AFETP (0.1 ± 0.04). The resulting average tumor-to-brain ratio at the late time points was significantly higher for 18F-AFETP (7.5 ± 0.1) than for 18F-FDG (1.3 ± 0.1) and 18F-FET (2.0 ± 0.3). Conclusion 18F-AFETP is a promising brain tumor imaging agent, providing rapid and persistent tumor visualization, with good tumor–to–normal-brain ratios in the DBT glioma model. High tumor-to-brain, tumor

  4. Effect of Harderian adenectomy on the statistical analyses of mouse brain imaging using positron emission tomography

    PubMed Central

    Kim, Minsoo; Woo, Sang-Keun; Yu, Jung Woo; Lee, Yong Jin; Kim, Kyeong Min; Kang, Joo Hyun; Eom, Kidong

    2014-01-01

    Positron emission tomography (PET) using 2-deoxy-2-[18F] fluoro-D-glucose (FDG) as a radioactive tracer is a useful technique for in vivo brain imaging. However, the anatomical and physiological features of the Harderian gland limit the use of FDG-PET imaging in the mouse brain. The gland shows strong FDG uptake, which in turn results in distorted PET images of the frontal brain region. The purpose of this study was to determine if a simple surgical procedure to remove the Harderian gland prior to PET imaging of mouse brains could reduce or eliminate FDG uptake. Measurement of FDG uptake in unilaterally adenectomized mice showed that the radioactive signal emitted from the intact Harderian gland distorts frontal brain region images. Spatial parametric measurement analysis demonstrated that the presence of the Harderian gland could prevent accurate assessment of brain PET imaging. Bilateral Harderian adenectomy efficiently eliminated unwanted radioactive signal spillover into the frontal brain region beginning on postoperative Day 10. Harderian adenectomy did not cause any post-operative complications during the experimental period. These findings demonstrate the benefits of performing a Harderian adenectomy prior to PET imaging of mouse brains. PMID:23820224

  5. Imaging local brain function with emission computed tomography

    SciTech Connect

    Kuhl, D.E.

    1984-03-01

    Positron emission tomography (PET) using /sup 18/F-fluorodeoxyglucose (FDG) was used to map local cerebral glucose utilization in the study of local cerebral function. This information differs fundamentally from structural assessment by means of computed tomography (CT). In normal human volunteers, the FDG scan was used to determine the cerebral metabolic response to conrolled sensory stimulation and the effects of aging. Cerebral metabolic patterns are distinctive among depressed and demented elderly patients. The FDG scan appears normal in the depressed patient, studded with multiple metabolic defects in patients with multiple infarct dementia, and in the patients with Alzheimer disease, metabolism is particularly reduced in the parietal cortex, but only slightly reduced in the caudate and thalamus. The interictal FDG scan effectively detects hypometabolic brain zones that are sites of onset for seizures in patients with partial epilepsy, even though these zones usually appear normal on CT scans. The future prospects of PET are discussed.

  6. Post-Surgical Atypical FDG-PET Uptake

    PubMed Central

    Dubroff, Jacob G.; Alavi, Abass; Friedberg, Joseph S.; Cengel, Keith A.

    2011-01-01

    False positive recognition is crucial for proper interpretation of FDG-PET studies. The authors present a case of a woman who underwent surgery over a month prior to PET/CT imaging which revealed significant tracer uptake within muscles and soft tissue in several sites contralateral to the location of surgery. The FDG-PET images of this case illustrate the importance of communication between physicians ordering and physicians reading FDG-PET/CT scans as well as atypical FDG-PET findings that could be interpreted as concerning but are, in fact, innocuous. This study also demonstrates the unusual glucose metabolic patterns which may arise following treatment be it surgical, chemotherapeutic or radiation. PMID:19851183

  7. 18F-FDG-avid brunner gland hyperplasia.

    PubMed

    Park, Seol Hoon; Park, Kwang-Min; Kim, Jae Seung

    2014-08-01

    Brunner gland hyperplasia, a rare duodenal tumor, usually presents with benign features. A 68-year-old man with a history of anemia presented with a polypoid duodenal mass that was detected by CT and esophagogastroduodenoscopy. This mass showed high F-FDG avidity on PET/CT and was histopathologically confirmed as Brunner gland hyperplasia. We suggest that Brunner gland hyperplasia should be considered in the differential diagnosis of F-FDG-avid duodenal tumors.

  8. F-18 labeled 3-fluorodiazepam

    SciTech Connect

    Luxen, A.; Barrio, J.R.; Bida, G.T.; Satyamurthy, N.; Phelps, M.E.

    1985-05-01

    3-Fluorodiazepam is a new and potent antianxiety agent with prolonged action. The authors found that molecular fluorine (0.5% in Ne) reacts cleanly with diazepam in freon or chloroform at room temperature to produce 3-fluorodiazepam in good yields. Successful syntheses have employed 2:1 to 5:1 molar ratios diazepam: fluorine to minimize the formation of byproducts. (/sup 18/F) 3-Fluorodiazepam, a potential candidate for PET studies, (specific activity 3-5 Ci/mmol) has been synthesized from /sup 18/F-F/sub 2/ using the same procedure, followed by column chromatographic purification (Silicagel, dichloromethane: ethyl acetate, 5:1) with a radiochemical yield of 12-20% (50% maximum) and a chemical and radiochemical purity >99% as judged by reversed-phase high pressure liquid chromatography analysis (Ultrasyl octyl column, 10 ..mu.. m, 4.6 x 250 mm i.d., 60% MeOH 40% water; flow rate, 1.0 ml/min; retention time for (/sup 18/F) fluorodiazepam, 11.4 min; for diazepam, 13.5 min; radioactivity and ultraviolet detectors). Lower radiochemical yields (5-7%), and significant formation of by-products were observed when (/sup 18/F)acetylhypofluorite, prepared in the gasphase, was used as the reagent. Readily accessible routes to /sup 18/F-labeled benzodiazepines of higher specific activity were also investigated. Approaches to the synthesis of high specific activity (>200 Ci/mmol) (/sup 18/F)3-fluorodiazepam involve nucleophilic displacement at carbon-3 (e.g. from 3-chlorodiazepam) with (/sup 18/F)fluoride ion. The results presented here demonstrate the synthetic accessibility of /sup 18/F-labeled benzodiazepines for application in neurotransmitter ligand studies with PET.

  9. Diminished glucose transport and phosphorylation in Alzheimer`s disease determined by dynamic FDG-PET

    SciTech Connect

    Piert, M.; Koeppe, R.A.; Giordani, B.; Berent, S.; Kuhl, D.E.

    1996-02-01

    Using dynamic [{sup 18}F] fluorodeoxyglucose (FDG) and PET, kinetic rate constants that describe influx (K{sub 1}) and efflux (k{sub 2}) of FDG as well s phosphorylation (k{sub 3}) and dephosphorylation (k{sub 4}) were determined in patients with probable Alzheimer`s disease and similarly aged normal controls. The regional cerebral metabolic rate for glucose (CMR{sub glu}) was calculated from individually fitted rate constants in frontal, temporal, parietal and occipital cerebral cortex, caudate nucleus, putamen, thalamus and cerebellar cortex. Dynamic PET scans were obtained in normal controls (n = 10, mean age = 67) and Alzheimer`s disease patients (n = 8, mean age = 67) for 60 min following injection of 10 mCi of FDG. The Alzheimer`s disease group was characterized by decreases of the CMR{sub glu} ranging from 13.3% in the frontal to 40.9% in the parietal cortex, which achieved significance in all regions except the thalamus. K{sub 1} was significantly reduced in the parietal (p < 0.01) and temporal cortices (p < 0.005), temporal and occipital cortex, and in the putamen and cerebellum (p < 0.05). The rate constants k{sub 2} and k{sub 4} were unchanged in the Alzheimer`s disease group. These data suggest that hypometabolism in Alzheimer`s disease is related to reduced glucose phosphorylation activity as well as diminished glucose transport, particularly in the most metabolically affected areas of the brain, the parietal and temporal cortex. 60 refs., 2 figs., 2 tabs.

  10. Subcutaneous fatty tissue metastasis from renal cell carcinoma detected with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging

    PubMed Central

    Tatoğlu, Mehmet Tarιk; Özülker, Tamer; Değirmenci, Hülya; Sayιlgan, Ayşe Tülay

    2011-01-01

    A patient who had undergone left radical nephrectomy 11 years ago for renal cell carcinoma (RCC) was referred to our clinic for restaging. Fluorine-18 fluorodeoxyglucose (F18-FDG) positron emission tomography/computed tomography (F18-FDG PET/CT) showed hypometabolic area in left frontal region of the brain and increased FDG uptake in the subcutaneous fatty tissues of the right thigh. Histopathological examination of the biopsy material from the left frontal region and right gluteal region revealed metastasis of clear cell type RCC. Seven months later, a magnetic resonance ımaging (MRI) of right cruris showed a contrast-enhancing lesion with a diameter of 3.5 cm, located at the subcutaneous area of posterior part of right cruris. A concomitant F18-FDG PET/CT detected an increased FDG uptake focus in the proximal third of right cruris adjacent to the muscle planes and this finding was consistent with metastasis of RCC. PMID:21969776

  11. Right Limbic FDG-PET Hypometabolism Correlates with Emotion Recognition and Attribution in Probable Behavioral Variant of Frontotemporal Dementia Patients

    PubMed Central

    Cerami, Chiara; Dodich, Alessandra; Iannaccone, Sandro; Marcone, Alessandra; Lettieri, Giada; Crespi, Chiara; Gianolli, Luigi; Cappa, Stefano F.; Perani, Daniela

    2015-01-01

    The behavioural variant of frontotemporal dementia (bvFTD) is a rare disease mainly affecting the social brain. FDG-PET fronto-temporal hypometabolism is a supportive feature for the diagnosis. It may also provide specific functional metabolic signatures for altered socio-emotional processing. In this study, we evaluated the emotion recognition and attribution deficits and FDG-PET cerebral metabolic patterns at the group and individual levels in a sample of sporadic bvFTD patients, exploring the cognitive-functional correlations. Seventeen probable mild bvFTD patients (10 male and 7 female; age 67.8±9.9) were administered standardized and validated version of social cognition tasks assessing the recognition of basic emotions and the attribution of emotions and intentions (i.e., Ekman 60-Faces test-Ek60F and Story-based Empathy task-SET). FDG-PET was analysed using an optimized voxel-based SPM method at the single-subject and group levels. Severe deficits of emotion recognition and processing characterized the bvFTD condition. At the group level, metabolic dysfunction in the right amygdala, temporal pole, and middle cingulate cortex was highly correlated to the emotional recognition and attribution performances. At the single-subject level, however, heterogeneous impairments of social cognition tasks emerged, and different metabolic patterns, involving limbic structures and prefrontal cortices, were also observed. The derangement of a right limbic network is associated with altered socio-emotional processing in bvFTD patients, but different hypometabolic FDG-PET patterns and heterogeneous performances on social tasks at an individual level exist. PMID:26513651

  12. Comparability of [(18)F]THK5317 and [(11)C]PIB blood flow proxy images with [(18)F]FDG positron emission tomography in Alzheimer's disease.

    PubMed

    Rodriguez-Vieitez, Elena; Leuzy, Antoine; Chiotis, Konstantinos; Saint-Aubert, Laure; Wall, Anders; Nordberg, Agneta

    2017-02-01

    For amyloid positron emission tomography tracers, the simplified reference tissue model derived ratio of influx rate in target relative to reference region (R1) has been shown to serve as a marker of brain perfusion, and, due to the strong coupling between perfusion and metabolism, as a proxy for glucose metabolism. In the present study, 11 prodromal Alzheimer's disease and nine Alzheimer's disease dementia patients underwent [(18)F]THK5317, carbon-11 Pittsburgh Compound-B ([(11)C]PIB), and 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) positron emission tomography to assess the possible use of early-phase [(18)F]THK5317 and R1 as proxies for brain perfusion, and thus, for glucose metabolism. Discriminative performance (prodromal vs Alzheimer's disease dementia) of [(18)F]THK5317 (early-phase SUVr and R1) was compared with that of [(11)C]PIB (early-phase SUVr and R1) and [(18)F]FDG. Strong positive correlations were found between [(18)F]THK5317 (early-phase, R1) and [(18)F]FDG, particularly in frontal and temporoparietal regions. Differences in correlations between early-phase and R1 ([(18)F]THK5317 and [(11)C]PIB) and [(18)F]FDG, were not statistically significant, nor were differences in area under the curve values in the discriminative analysis. Our findings suggest that early-phase [(18)F]THK5317 and R1 provide information on brain perfusion, closely related to glucose metabolism. As such, a single positron emission tomography study with [(18)F]THK5317 may provide information about both tau pathology and brain perfusion in Alzheimer's disease, with potential clinical applications.

  13. A FDG-PET Study of Metabolic Networks in Apolipoprotein E ε4 Allele Carriers.

    PubMed

    Yao, Zhijun; Hu, Bin; Zheng, Jiaxiang; Zheng, Weihao; Chen, Xuejiao; Gao, Xiang; Xie, Yuanwei; Fang, Lei

    2015-01-01

    Recently, some studies have applied the graph theory in brain network analysis in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). However, relatively little research has specifically explored the properties of the metabolic network in apolipoprotein E (APOE) ε4 allele carriers. In our study, all the subjects, including ADs, MCIs and NCs (normal controls) were divided into 165 APOE ε4 carriers and 165 APOE ε4 noncarriers. To establish the metabolic network for all brain regions except the cerebellum, cerebral glucose metabolism data obtained from FDG-PET (18F-fluorodeoxyglucose positron emission tomography) were segmented into 90 areas with automated anatomical labeling (AAL) template. Then, the properties of the networks were computed to explore the between-group differences. Our results suggested that both APOE ε4 carriers and noncarriers showed the small-world properties. Besides, compared with APOE ε4 noncarriers, the carriers showed a lower clustering coefficient. In addition, significant changes in 6 hub brain regions were found in between-group nodal centrality. Namely, compared with APOE ε4 noncarriers, significant decreases of the nodal centrality were found in left insula, right insula, right anterior cingulate, right paracingulate gyri, left cuneus, as well as significant increases in left paracentral lobule and left heschl gyrus in APOE ε4 carriers. Increased local short distance interregional correlations and disrupted long distance interregional correlations were found, which may support the point that the APOE ε4 carriers were more similar with AD or MCI in FDG uptake. In summary, the organization of metabolic network in APOE ε4 carriers indicated a less optimal pattern and APOE ε4 might be a risk factor for AD.

  14. Spin-Tunnel Investigation of a 1/28-Scale Model of the NASA F-18 High Alpha Research Vehicle (HARV) with and without Vertical Tails

    NASA Technical Reports Server (NTRS)

    Fremaux, C. Michael

    1997-01-01

    An investigation was conducted in the NASA Langley 20-Foot Vertical Spin Tunnel to determine the developed spin and spin-recovery characteristics of a 1/28-scale, free-spinning model of the NASA F-18 HARV (High Alpha Research Vehicle) airplane that can configured with and without the vertical tails installed. The purpose of the test was to determine what effects, if any, the absence of vertical tails (and rudders) had on the spin and spin-recovery capabilities of the HARV. The model was ballasted to dynamically represent the full-scale airplane at an altitude of 25,000 feet. Erect and inverted spin tests with symmetric mass loadings were conducted with the free-spinning model. The model results indicate that the basic airplane with vertical tails installed (with unaugmented control system) will exhibit fast, flat erect and inverted spins from which acceptable recoveries can be made. Removing the vertical tails had little effect on the erect spin mode, but did degrade recoveries from erect spins. In contrast, inverted spins without the vertical tails were significantly more severe than those with the tails installed.

  15. KEY COMPARISON: Update of the BIPM comparison BIPM.RI(II)-K1.F-18 of activity measurements of the radionuclide 18F to include the NPL

    NASA Astrophysics Data System (ADS)

    Ratel, G.; Michotte, C.; Woods, M. J.

    2003-01-01

    Since 2001, four national metrology institutes (NMIs) have submitted four samples of known activity of 18F to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures, the most recent being that of the NPL (UK). The activities ranged from about 1 MBq to 8 MBq. The key comparison reference value (KCRV) has been recalculated to include the latest value and the degrees of equivalence between each equivalent activity measured in the SIR and the key comparison reference value (KCRV) have been calculated and the results are given in the form of a matrix. A graphical presentation is also given. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by Section II of the Consultative Committee for Ionizing Radiation (CCRI(II)), comparison identifier BIPM.RI(II)-K1.F-18, according to the provisions of the Mutual Recognition Arrangement (MRA).

  16. KEY COMPARISON: Update of the BIPM comparison BIPM.RI(II)-K1.F-18 of activity measurements of the radionuclide 18F to include the CIEMAT

    NASA Astrophysics Data System (ADS)

    Ratel, G.; Michotte, C.; García-Toraño, E.; Los Arcos, J.-M.

    2004-01-01

    Since 2001, five national metrology institutes (NMIs) have submitted five samples of known activity of 18F to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), the most recent being that of the CIEMAT (Spain). The activities ranged from about 1 MBq to 18 MBq. The key comparison reference value (KCRV) has been recalculated to include the latest value and the degrees of equivalence between each equivalent activity measured in the SIR have been calculated and the results are given in the form of a matrix. A graphical presentation is also given for this key comparison with identifier BIPM.RI(II)-K1.F-18. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by Section II of the Consultative Committee for Ionizing Radiation (CCRI(II)), according to the provisions of the Mutual Recognition Arrangement (MRA).

  17. Flight-Determined Subsonic Longitudinal Stability and Control Derivatives of the F-18 High Angle of Attack Research Vehicle (HARV) with Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Iliff, Kenneth W.; Wang, Kon-Sheng Charles

    1997-01-01

    The subsonic longitudinal stability and control derivatives of the F-18 High Angle of Attack Research Vehicle (HARV) are extracted from dynamic flight data using a maximum likelihood parameter identification technique. The technique uses the linearized aircraft equations of motion in their continuous/discrete form and accounts for state and measurement noise as well as thrust-vectoring effects. State noise is used to model the uncommanded forcing function caused by unsteady aerodynamics over the aircraft, particularly at high angles of attack. Thrust vectoring was implemented using electrohydraulically-actuated nozzle postexit vanes and a specialized research flight control system. During maneuvers, a control system feature provided independent aerodynamic control surface inputs and independent thrust-vectoring vane inputs, thereby eliminating correlations between the aircraft states and controls. Substantial variations in control excitation and dynamic response were exhibited for maneuvers conducted at different angles of attack. Opposing vane interactions caused most thrust-vectoring inputs to experience some exhaust plume interference and thus reduced effectiveness. The estimated stability and control derivatives are plotted, and a discussion relates them to predicted values and maneuver quality.

  18. KEY COMPARISON: Update of the BIPM comparison BIPM.RI(II)-K1.F-18 of activity measurements of the radionuclide 18F to include the PTB

    NASA Astrophysics Data System (ADS)

    Ratel, G.; Michotte, C.; Kossert, K.; Janßen, H.

    2006-01-01

    Since 2001, six national metrology institutes (NMIs) have submitted six samples of known activity of 18F to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), the most recent being that of the PTB (Germany). The activities ranged from about 1 MBq to 18 MBq. The key comparison reference value (KCRV) has been recalculated to include the latest value, with the agreement of the CCRI(II). The degrees of equivalence between each equivalent activity measured in the SIR have been recalculated and the results are given in the form of a matrix. A graphical presentation is also given for this key comparison with identifier BIPM.RI(II)-K1.F-18. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by Section II of the Consultative Committee for Ionizing Radiation (CCRI(II)), according to the provisions of the Mutual Recognition Arrangement (MRA).

  19. In-flight leading-edge extension vortex flow-field survey measurements on a F-18 aircraft at high angle of attack

    NASA Technical Reports Server (NTRS)

    Richwine, David M.; Fisher, David F.

    1992-01-01

    Flow-field measurements on the leading-edge extension (LEX) of the F-18 High Alpha Research Vehicle (HARV) were obtained using a rotating rake with 16 hemispherical-tipped five-hole probes. Detailed pressure, velocity, and flow direction data were obtained through the LEX vortex core. Data were gathered during 1-g quasi-stabilized flight conditions at angles of attack alpha from 10 degrees to 52 degrees and at Reynolds numbers based on mean aerodynamic cord up to 16 x 10(exp 6). Normalized dynamic pressures and crossflow velocities clearly showed the primary vortex above the LEX and formation of a secondary vortex at higher angles of attack. The vortex was characterized by a ring of high dynamic pressure surrounding a region of low dynamic pressure at the vortex core center. The vortex core, subcore diameter, and vertical location of the core above the LEX increased with angle of attack. Minimum values for static pressure were obtained in the vortex subcore and decreased nearly linearly with increasing angle of attack until vortex breakdown. Rake-measured static pressures were consistent with previously documented surface pressures and showed good agreement with flow visualization flight test results. Comparison of the LEX vortex flight test data to computational solutions at alpha approximately equals 19 degrees and 30 degrees showed fair correlation.

  20. An atypical sarcoidosis involvement in FDG PET/CT

    PubMed Central

    Robin, Philippe; Benigni, Paolo; Feger, Benoit; Salaun, Pierre-Yves; Abgral, Ronan

    2016-01-01

    Abstract Rationale: Sarcoidosis is an idiopathic systemic inflammatory granulomatous disorder comprised of epithelioid and multinucleated giant cells with little necrosis which involve various organs. Laryngeal involvement is extremely rare, with a prevalence of about 0.5 to 1%. Diagnoses: Here we present a case of laryngeal involvement of sarcoidosis demonstrated on 18F-Fluorodesoxyglucose Positron-Emission Tomography/Computed Tomography (FDG PET/CT). Patient concerns: A 63 year-old man suffering from dysphonia was referred to our department for characterization of laryngeal lesion suspicious for cancer with non-informative biopsy, the sample was not sufficient for diagnosis. Interventions: FDG PET/CT showed a pathological uptake on the right vocal cord, but also highlighted a bilateral uptake in intrathoracic hilar lymphadenopathy areas, typically found in several inflammatory diseases. Outcomes: New laryngeal targeted biopsies revealed non-caseating epithelioid granulomas suggesting sarcoidosis involvement. After 6 months of systemic steroid treatment, FDG PET/CT showed a significant decrease of the laryngeal uptake. Lessons: This case shows the usefulness of FDG PET/CT to accurately assess inflammatory activity in rare extra-pulmonary sarcoidosis involvement. Moreover, this case emphasizes that FDG PET/CT is an interesting tool for assessing therapeutic efficacy of inflammatory diseases such as sarcoidosis. PMID:28033265

  1. FDG-PET evaluation of indeterminate pancreatic masses

    SciTech Connect

    Ho, Chi-Lai; Dehdashti, Farrokh; Griffeth, L.K.

    1996-05-01

    The purpose of this study was to assess the-ability of PET with 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (FDG) to differentiate benign from malignant pancreatic masses in patients with indeterminate findings on CT. We performed FDG-PET on 12 patients with indeterminate mass lesions and 2 patients with CT findings typical for malignancy. Eight were found to have pancreatic carcinoma and six had benign lesions. The final diagnosis was histopathologically confirmed in all patients but two with a presumed diagnosis of focal pancreatitis based on stable clinical follow-up for at least 12 months. Lesion uptake of FDG was evaluated qualitatively and semi-quantitatively by determination of the standardized uptake value (SUV). With use of a 2.5 cutoff value for SUV, all eight malignant and four of six benign lesions were correctly categorized. Qualitative evaluation gave the same results. The two false-positive lesions had elevated SUV values of 3.4 and 3.8, respectively. Our results indicate that FDG-PET has potential value for assessing patients with CT findings that are indeterminate for pancreatic carcinoma. FDG-PET may obviate invasive diagnostic procedures in many patients with benign disease. 36 refs., 2 figs., 1 tab.

  2. Analysis of Pretreatment FDG-PET SUV Parameters in Head-and-Neck Cancer: Tumor SUV{sub mean} Has Superior Prognostic Value

    SciTech Connect

    Higgins, Kristin A.; Hoang, Jenny K.; Roach, Michael C.; Chino, Junzo; Yoo, David S.; Turkington, Timothy G.; Brizel, David M.

    2012-02-01

    Purpose: To evaluate the prognostic significance of different descriptive parameters in head-and-neck cancer patients undergoing pretreatment [F-18] fluoro-D-glucose-positron emission tomography (FDG-PET) imaging. Patients and Methods: Head-and-neck cancer patients who underwent FDG-PET before a course of curative intent radiotherapy were retrospectively analyzed. FDG-PET imaging parameters included maximum (SUV{sub max}), and mean (SUV{sub mean}) standard uptake values, and total lesion glycolysis (TLG). Tumors and lymph nodes were defined on co-registered axial computed tomography (CT) slices. SUV{sub max} and SUV{sub mean} were measured within these anatomic regions. The relationships between pretreatment SUV{sub max}, SUV{sub mean}, and TLG for the primary site and lymph nodes were assessed using a univariate analysis for disease-free survival (DFS), locoregional control (LRC), and distant metastasis-free survival (DMFS). Kaplan-Meier survival curves were generated and compared via the log-rank method. SUV data were analyzed as continuous variables. Results: A total of 88 patients was assessed. Two-year OS, LRC, DMFS, and DFS for the entire cohort were 85%, 78%, 81%, and 70%, respectively. Median SUV{sub max} for the primary tumor and lymph nodes was 15.4 and 12.2, respectively. Median SUV{sub mean} for the primary tumor and lymph nodes was 7 and 5.2, respectively. Median TLG was 770. Increasing pretreatment SUV{sub mean} of the primary tumor was associated with decreased disease-free survival (p = 0.01). Neither SUV{sub max} in the primary tumor or lymph nodes nor TLG was prognostic for any of the clinical endpoints. Patients with pretreatment tumor SUV{sub mean} that exceeded the median value (7) of the cohort demonstrated inferior 2-year DFS relative to patients with SUV{sub mean} {<=} the median value of the cohort, 58% vs. 82%, respectively, p = 0.03. Conclusion: Increasing SUV{sub mean} in the primary tumor was associated with inferior DFS. Although not

  3. Synthesis, biological evaluation, and molecular dynamics (MD) simulation studies of three novel F-18 labeled and focal adhesion kinase (FAK) targeted 5-bromo pyrimidines as radiotracers for tumor.

    PubMed

    Fang, Yu; Wang, Dawei; Xu, Xingyu; Liu, Jianping; Wu, Aiqin; Li, Xiang; Xue, Qianqian; Wang, Huan; Wang, Hang; Zhang, Huabei

    2017-02-15

    Focal adhesion kinase (FAK) is considered as an attractive target for oncology. A series of F-18 labeled 5-bromo-N(2)-(4-(2-fluoro-pegylated (FPEG))-3,5-dimethoxyphenyl)-N(4)-(4-methoxyphenyl)pyrimidine-2,4-diamine derivatives were prepared and evaluated as the FAK targeted radiotracers for the early diagnoses of tumor. For the study of the FAK targeted drug molecules, this was the first attempt to develop the tumor diagnostic imaging agents on the radiopharmaceutical level. They inhibited the activity of FAK with IC50 in the range of 91.4-425.7 nM, and among which the result of the [(19)F]2 was relatively good and had a modest IC50 of 91.4 nM. The [(19)F]2 was also profiled in vitro against some other kinds of cancer-related kinases (including two kinds of non-receptor tyrosine kinase: PYK2 and JAK2, and three kinds of receptor tyrosine kinase: IGF-1R, EGFR and PDGFRβ). It displayed 25.2 folds selectivity against PYK2, 35.1 folds selectivity against EGFR, and more than 100 folds selectivity against IGF-1R, JAK2 and PDGFRβ. For the biodistribution in S180 bearing mice, the corresponding [(18)F]2 were also relatively good, with modest tumor uptake of 5.47 ± 0.19 and 5.80 ± 0.06 %ID/g at 15 and 30 min post-injection, respectively. Furthermore, its tumor/muscle, tumor/bone and tumor/blood ratio at 15 min post-injection were 3.16, 2.53 and 4.52, respectively. And its tumor/muscle, tumor/bone and tumor/blood ratio at 30 min post-injection were 3.14, 2.76 and 4.43, respectively. In addition, coronal micro-PET/CT images of a mouse bearing S180 tumor clearly confirmed that [(18)F]2 could be accumulated in tumor, especially at 30 min post-injection. Besides, for the [(18)F]2, both the biodistribution data and the micro-PET/CT imaging study showed significantly reduced uptake of the radiotracer in the tumor tissue at 30 min post-injection in mice that received PF-562,271 (one of the reported best selective FAK inhibitor which was developed by Pfitzer Inc. and

  4. Functional imaging of the brain with/sup 18/F-fluorodeoxyglucose

    SciTech Connect

    Reivich, M; Greenberg, J; Alavi, A; Hand, P; Rintelmann, W; Rosenquist, A; Christman, D; Fowler, J; MacGregor, R; Wolf, A

    1980-01-01

    A techniques is reported by which it is possible to determine which regions of the human brain become functionally active in response to a specific stimulus. The method utilizes /sup 18/F-2-fluoro-2-deoxyglucose ((/sup 18/F)-FDG) administered as a bolus. (/sup 18/F)-FDG is used as a tracer for the exchange of glucose between plasma and brain and its phosphorylation. The subject is then scanned during administration of a physiologic stimulus by position emission tomography and the three-dimensional distribution of /sup 18/F activity in the brain determined. (ACR)

  5. FDG PET/MR Imaging Coregistration Helps Predict Survival in Patients with Glioblastoma and Radiologic Progression after Standard of Care Treatment.

    PubMed

    Leiva-Salinas, Carlos; Schiff, David; Flors, Lucia; Patrie, James T; Rehm, Patrice K

    2016-10-19

    Purpose To determine the correlation between metabolic activity at fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and survival in patients with glioblastoma and suspected progression at posttherapy magnetic resonance (MR) imaging. Materials and Methods The authors retrospectively examined the relationship between metabolic activity at FDG PET in the residual lesion identified at brain MR imaging and survival time in 56 patients with glioblastoma who were treated with postoperative concurrent radiation and temozolomide therapy and who underwent FDG PET/computed tomography because of radiologic deterioration at follow-up MR imaging between 2006 and 2015. A normalized metric of metabolic activity in the residual lesion (standardized uptake value ratio [SUVr]) was calculated as the maximum standardized uptake value (SUVmax) in the tumor relative to that in healthy white matter. The primary end point of the study was survival time from PET. Patients were stratified according to SUVr. Comparisons of risk for death between subgroups were made with the log-hazard ratio of the Cox proportional hazard model. Results There was a significant association between overall survival and SUVr in the residual lesion (P = .006), and a survival benefit was observed in patients with SUVr of less than 1.7, who had a median survival time of 23.1 months (95% confidence interval [CI]: 12.7, 38.9), which was significantly longer than that in patients with an SUVr of 2.0 to less than 2.5 and those with an SUVr of at least 2.5, who had a median survival time of 10.1 (95% CI: 2.4, 15.9; P = .008) and 7.5 (95% CI: 3.9, 9.7; P < .001) months, respectively. Conclusion Patients with glioblastoma whose posttherapy MR images showed a residual lesion with high relative metabolic activity at FDG PET had a shorter survival time than did those with low activity at FDG PET. (©) RSNA, 2016.

  6. Quantitative techniques in 18FDG PET scanning in oncology.

    PubMed

    Castell, F; Cook, G J R

    2008-05-20

    The clinical applications of (18)F-fluoro-2-deoxyglucose ((18)FDG) positron emission tomography (PET) in oncology are becoming established. While simple static scanning techniques are used for the majority of routine clinical examinations, increasing use of PET in clinical trials to monitor treatment response with (18)FDG and novel tracers reflecting different pharmacodynamic end points, often necessitates a more complex and quantitative analysis of radiopharmaceutical kinetics. A wide range of PET analysis techniques exist, ranging from simple visual analysis and semiquantitative methods to full dynamic studies with kinetic analysis. These methods are discussed, focusing particularly on the available methodologies that can be utilised in clinical trials.

  7. A Novel Method for Direct site-specific Radiolabeling of Peptides Using [18F]FDG

    PubMed Central

    Namavari, Mohammad; Cheng, Zhen; Zhang, Rong; De, Abhijit; Levi, Jelena; Hoerner, Joshua K.; Yaghoubi, Shahriar S.; Syud, Faisal A.; Gambhir, Sanjiv S.

    2009-01-01

    We have used the well-accepted and easily available 2-[18F]Fluoro-2-deoxyglucose ([18F]FDG) positron emission tomography (PET) tracer as a prosthetic group for synthesis of 18F-labeled peptides. We herein report the synthesis of [18F]FDG-RGD (18F labeled linear RGD) and [18F]FDG-cyclo(RGDDYK) (18F labeled cyclic RGD) as examples of the use of [18F]FDG. We have successfully prepared [18F]FDG-RGD and [18F]FDG-cyclo(RGDDYK) in 27.5% and 41% radiochemical yields (decay corrected) respectively. The receptor binding affinity study of FDG-cyclo(RGDDYK) for integrin αvβ3 , using αvβ3 positive U87MG cells confirmed a competitive displacement with 125I-echistatin as a radioligand. The IC50 value for FDG-cyclo(RGDDYK) was determined to be 0.67 ± 0.19µM. High contrast small animal PET images with relatively moderate tumor uptake were observed for [18F]FDG-RGD and [18F]FDG-cyclo(RGDDYK) as PET probes in xenografts models expressing αvβ3 integrin. In conclusion, we have successfully used [18F]FDG as a prosthetic group to prepare 18F]FDG-RGD and [18F]FDG-cyclic[RGDDYK] based on a simple one step radiosynthesis. The one step radiosynthesis methodology consists of chemoselective oxime formation between an aminooxy functionalized peptide and [18F]FDG. The results have implications for radiolabeling of other macromolecules and would lead to a very simple strategy for routine pre-clinical and clinical use. PMID:19226160

  8. Quantitative Analysis of Torso FDG-PET Scans by Using Anatomical Standardization of Normal Cases from Thorough Physical Examinations.

    PubMed

    Hara, Takeshi; Kobayashi, Tatsunori; Ito, Satoshi; Zhou, Xiangrong; Katafuchi, Tetsuro; Fujita, Hiroshi

    2015-01-01

    Understanding of standardized uptake value (SUV) of 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography (FDG-PET) depends on the background accumulations of glucose because the SUV often varies the status of patients. The purpose of this study was to develop a new method for quantitative analysis of SUV of FDG-PET scan images. The method included an anatomical standardization and a statistical comparison with normal cases by using Z-score that are often used in SPM or 3D-SSP approach for brain function analysis. Our scheme consisted of two approaches, which included the construction of a normal model and the determination of the SUV scores as Z-score index for measuring the abnormality of an FDG-PET scan image. To construct the normal torso model, all of the normal images were registered into one shape, which indicated the normal range of SUV at all voxels. The image deformation process consisted of a whole body rigid registration of shoulder to bladder region and liver registration and a non-linear registration of body surface by using the thin-plate spline technique. In order to validate usefulness of our method, we segment suspicious regions on FDG-PET images manually, and obtained the Z-scores of the regions based on the corresponding voxels that stores the mean and the standard deviations from the normal model. We collected 243 (143 males and 100 females) normal cases to construct the normal model. We also extracted 432 abnormal spots from 63 abnormal cases (73 cancer lesions) to validate the Z-scores. The Z-scores of 417 out of 432 abnormal spots were higher than 2.0, which statistically indicated the severity of the spots. In conclusions, the Z-scores obtained by our computerized scheme with anatomical standardization of torso region would be useful for visualization and detection of subtle lesions on FDG-PET scan images even when the SUV may not clearly show an abnormality.

  9. TU-G-BRA-07: Characterization of Tumor Proliferation During Successive Cycles of Anti-Angiogenic Therapy Using [F-18]FLT PET/CT

    SciTech Connect

    Scarpelli, M; Perlman, S; Harmon, S; Perk, T; Scully, P; Bruce, J; Liu, G; Jeraj, R

    2015-06-15

    Purpose: Studies have shown cessation of anti-angiogenic treatment during the first cycle of therapy resulted in rebound of tumor proliferation (flare). This study characterized proliferation dynamics during the first and third cycle of anti-angiogenic treatment using [F-18]FLT PET. Methods: Thirteen patients with various solid cancers were treated with Axitinib (Pfizer, Inc) at a dose of 5mg orally, twice daily, on contiguous three-week cycles with intermittent dosing (two-weeks-on/one-week-off). All patients received three FLT PET/CT scans during cycle 1 (C1): at baseline (C1D0), peak Axitinib concentration (C1D14), and the end of washout (C1D21). Ten patients received up to an additional three scans at corresponding time points during cycle 3 (C3). Lesions were identified by a nuclear medicine physician and manually contoured. Tumor burden was quantified using standard SUV metrics. Correlations between imaging metrics across C1 and C3 were calculated using the Spearman correlation. Results: At C1 peak drug concentration 11/13 patients had decreases in SUVtotal, with median decrease of 50% (change from C1D0 to C1D14). At C3 peak drug concentration 7/7 patients had decreases in SUVtotal, with median decrease of 20% (C3D0 to C3D14). Proliferative flare during C1 washout (>20% increase from C1D14 to C1D21) occurred in 9/13 patients, with median SUVtotal increase of 190%. Flare was also seen in C3 for 5/5 patients, with median SUVtotal increase of 70% (change from C3D14 to C3D21). Correlations were found between changes in imaging metrics across C1 and C3, notably the change in SUVtotal from C1D0 to C1D21 and the change in SUVtotal from C1D0 to C3D0 (ρ = 0.80). Conclusion: Measurements of SUVtotal showed that both patient response to treatment and flare were evident in both cycles of treatment. Correlation between changes in SUVtotal across C1 and C3 suggest early time points could be used to characterize patient response in later cycles. Research funded in part by

  10. Effectiveness of infliximab in refractory FDG PET-positive sarcoidosis.

    PubMed

    Vorselaars, Adriane D M; Crommelin, Heleen A; Deneer, Vera H M; Meek, Bob; Claessen, Anke M E; Keijsers, Ruth G M; van Moorsel, Coline H M; Grutters, Jan C

    2015-07-01

    Inconclusive evidence for the efficacy of infliximab in sarcoidosis hinders the global use of this potentially beneficial drug. To study infliximab efficacy in a clinical setting, we performed a prospective open-label trial in patients refractory to conventional treatment. Patients (n=56) received eight infusions of 5 mg·kg(-1) infliximab. Pulmonary function, disease activity measured by (18)F-fluorodeoxyglucose (FDG) by positron emission tomography (PET) and quality of life were part of the clinical work-up. Infliximab levels were measured before every infusion. After 26 weeks of infliximab treatment, mean improvement in forced vital capacity (FVC) was 6.6% predicted (p=0.0007), whereas in the 6 months before start of treatment, lung function decreased. Maximum standardised uptake value (SUVmax) of pulmonary parenchyma on (18)F-FDG PET decreased by 3.93 (p<0.0001). High SUVmax of pulmonary parenchyma at baseline predicted FVC improvement (R=0.62, p=0.0004). An overall beneficial response was seen in 79% of patients and a partial response was seen in 17% of patients. No correlation between infliximab trough level (mean 18.0 µg·mL(-1)) and initial response was found. In conclusion, infliximab causes significant improvement in FVC in refractory (18)F-FDG PET positive sarcoidosis. Especially in pulmonary disease, high (18)F-FDG PET SUVmax values at treatment initiation predict clinically relevant lung function improvement. These results suggest that inclusion of (18)F-FDG PET is useful in therapeutic decision-making in complex sarcoidosis.

  11. Whole Body FDG-PET and FDG-PET/CT in Patients with Suspected Paraneoplastic Syndrome: A Systematic review and Meta-analysis of Diagnostic Accuracy.

    PubMed

    Sheikhbahaei, Sara; Marcus, Charles; Fragomeni, Roberto S; Rowe, Steven P; Javadi, Mehrbod S; Solnes, Lilja B

    2016-12-15

    The purpose of this study was to assess the diagnostic performance of whole body (18)F-FDG-PET or (18)F-FDG-PET/CT for detection of underlying malignancy in patients with clinically suspected neurological and non-neurological paraneoplastic syndromes.

  12. Fluorine F 18 Fluorodopa-Labeled PET Scan in Planning Surgery and Radiation Therapy in Treating Patients With Newly Diagnosed High- or Low-Grade Malignant Glioma

    ClinicalTrials.gov

    2016-10-10

    Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Anaplastic Oligodendroglioma; Adult Brain Stem Glioma; Adult Diffuse Astrocytoma; Adult Ependymoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Mixed Glioma; Adult Myxopapillary Ependymoma; Adult Oligodendroglioma; Adult Pilocytic Astrocytoma; Adult Pineal Gland Astrocytoma; Adult Subependymal Giant Cell Astrocytoma; Adult Subependymoma

  13. Usefulness of 3-dimensional stereotactic surface projection FDG PET images for the diagnosis of dementia

    PubMed Central

    Kim, Jahae; Cho, Sang-Geon; Song, Minchul; Kang, Sae-Ryung; Kwon, Seong Young; Choi, Kang-Ho; Choi, Seong-Min; Kim, Byeong-Chae; Song, Ho-Chun

    2016-01-01

    Abstract To compare diagnostic performance and confidence of a standard visual reading and combined 3-dimensional stereotactic surface projection (3D-SSP) results to discriminate between Alzheimer disease (AD)/mild cognitive impairment (MCI), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD). [18F]fluorodeoxyglucose (FDG) PET brain images were obtained from 120 patients (64 AD/MCI, 38 DLB, and 18 FTD) who were clinically confirmed over 2 years follow-up. Three nuclear medicine physicians performed the diagnosis and rated diagnostic confidence twice; once by standard visual methods, and once by adding of 3D-SSP. Diagnostic performance and confidence were compared between the 2 methods. 3D-SSP showed higher sensitivity, specificity, accuracy, positive, and negative predictive values to discriminate different types of dementia compared with the visual method alone, except for AD/MCI specificity and FTD sensitivity. Correction of misdiagnosis after adding 3D-SSP images was greatest for AD/MCI (56%), followed by DLB (13%) and FTD (11%). Diagnostic confidence also increased in DLB (visual: 3.2; 3D-SSP: 4.1; P < 0.001), followed by AD/MCI (visual: 3.1; 3D-SSP: 3.8; P = 0.002) and FTD (visual: 3.5; 3D-SSP: 4.2; P = 0.022). Overall, 154/360 (43%) cases had a corrected misdiagnosis or improved diagnostic confidence for the correct diagnosis. The addition of 3D-SSP images to visual analysis helped to discriminate different types of dementia in FDG PET scans, by correcting misdiagnoses and enhancing diagnostic confidence in the correct diagnosis. Improvement of diagnostic accuracy and confidence by 3D-SSP images might help to determine the cause of dementia and appropriate treatment. PMID:27930593

  14. Update of the BIPM comparison BIPM.RI(II)-K1.F-18 of activity measurements of the radionuclide 18F to include the 2010 result of the LNE-LNHB (France)

    NASA Astrophysics Data System (ADS)

    Michotte, C.; Ratel, G.; Courte, S.; Cassette, P.; Moune, M.

    2016-01-01

    Since 2001, six national metrology institutes (NMI) have submitted seven samples of known activity of 18F to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.F-18. The values of the activity submitted were between about 1 MBq and 18 MBq. The primary standardization result for the LNE-LNHB, France, replaces their earlier result of 2002 and the key comparison reference value (KCRV) has been recalculated. In the frame of the BIPM.RI(II)-K4.F18 comparison, the NPL updated their result in the KCDB. Consequently there are now five results in the BIPM.RI(II)-K1.F-18 comparison. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  15. Incidental Detection of Femoral Pseudoaneurysm at 18F-FDG PET/CT

    PubMed Central

    Nougaret, Stephanie; Ragucci, Monica; Bach, Ariadne M.; Carollo, Gabriella; Mannelli, Lorenzo

    2016-01-01

    A 72-year-old man with history of lung cancer and melanoma was referred for routine follow-up with 18F-FDG PET/CT. CT images showed a new mass in the right groin associated with mild FDG activity on 18F-FDG PET images. Subsequent ultrasound obtained the same day demonstrated flow within the lesion to be a pseudoaneurysm of the right femoral artery. PMID:26462043

  16. Increased 18F-FDG Uptake in Multiple Muscles in a Patient With Violent Cough.

    PubMed

    Wang, Yu; Shao, Fuqiang; Zhang, Li; Luo, Xiufang; Chen, Yue

    2017-03-31

    Increased muscular FDG uptake could be due to various causes. Detailed analysis combined with history might be helpful for image interpretation. We present FDG PET/CT findings of a 69-year-old woman with lung cancer. The images demonstrated intense FDG uptake in multiple muscles, likely due to cough before the PET/CT study. To relieve the patient's cough, codeine was administrated. The second F-FDG PET/CT was performed 2 days later. The images showed that the abnormal muscular activity had become decreased, which was slightly lower than hepatic activity.

  17. Normal variations and benign findings in pediatric 18F-FDG-PET/CT.

    PubMed

    Grant, Frederick D

    2014-04-01

    (18)F-FDG PET and PET/CT have a wide variety of indications in children and young adults. Oncologic indications are the most common, but others include neurology, sports medicine, cardiology, and infection imaging. Accurate interpretation of pediatric (18)F-FDG PET and PET/CT requires a technically adequate study and knowledgeable interpretation of the images. A successful pediatric (18)F-FDG PET requires age-appropriate patient preparation and consideration of patient age and developmental stage. Accurate interpretation of the study requires familiarity with normal patterns of physiologic (18)F-FDG uptake in children at all stages of development.

  18. Longitudinal assessment of a transgenic animal model of tauopathy by FDG-PET imaging.

    PubMed

    de Cristóbal, Javier; García-García, Luis; Delgado, Mercedes; Pérez, Mar; Pozo, Miguel A; Medina, Miguel

    2014-01-01

    Abnormal levels and hyperphosphorylation of tau protein have been proposed as the underlying cause of a group of neurodegenerative disorders collectively known as 'tauopathies'. The detrimental consequence is the loss of affinity between this protein and the microtubules, increased production of fibrillary aggregates, and the accumulation of insoluble intracellular neurofibrillary tangles. A similar phenotype can be observed in various preclinical models, which have been generated to study the role of tau protein in neurodegenerative disorders. In this study, we have analyzed the brain metabolic activity in an animal model of tauopathy (tauVLW transgenic mice), which has been previously reported to mimic some of the phenotypic features of these disorders. By using a non-invasive technique, positron emission tomography (PET), a longitudinal non-clinical follow up study was carried out during most of the lifespan of these transgenic mice, from the youth to the senescence stages. The results obtained point out to an aging-dependent decrease in 18F-fluoro-deoxyglucose (FDG) uptake in the cerebral areas analyzed, which was already significant at the adult age, i.e., 11 months, and became much more prominent in the oldest animals (19 months old). This observation correlates well with the histopathological observation of neurodegeneration in brain areas where there is overexpression of tau protein.

  19. Purulent lupus panniculitis unmasked by FDG-PET/CT scan

    PubMed Central

    van der Geest, Kornelis S.M.; Moerman, Rada V.; Koopmans, Klaas P.; Holman, Nicole D.; Janssen, Wilbert M.T.

    2016-01-01

    Abstract Rationale: Lupus panniculitis (LP) is a unique variant of cutaneous lupus erythematosus. Clinical manifestations are typically mild and include erythema, nodules, and small ulcers. In certain cases, diagnosing LP may be challenging. Skin overlying the typical subcutaneous inflammation may appear normal, and bacterial superinfections of the skin sometimes mask the underlying LP. It has been suggested that a computed tomography (CT) scan may help to identify obscure LP lesions. Here, we report a case of a 54-year-old woman with an unusually severe form of LP, in which the full disease extent was only revealed by a fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan. Patient concerns/Diagnoses/Interventions/Outcomes: Our patient initially presented with a bacterial infection of the skin. After initial improvement with antibiotic treatment, new erythematous lesions and sterile subcutaneous pus collections developed. An FDG-PET/CT scan revealed extensive subcutaneous inflammation at sites that had appeared normal during physical examination and on CT scan. As the subcutaneous lesions showed a remarkably linear pattern on FDG-PET/CT scan, the patient was suspected of having LP. After confirmation of this diagnosis by a deep-skin biopsy, our patient was treated with systemic glucocorticoids. Eventually, our patient succumbed to complications of LP and its treatment. Lessons: Our case demonstrates that clinical manifestations of LP are not always mild and that timely diagnosis is needed. Furthermore, we show that obscure LP lesions are more readily identified on an FDG-PET/CT scan than CT scan. PMID:27902603

  20. Protein rich diet suppressed net and unidirectional clearances of 6-[F-18]Fluoro-DOPA to striatum but did not alter relative DOPA decarboxylase activity

    SciTech Connect

    Kuwabara, H.; Cumming, P.; Reutens, D.

    1994-05-01

    We examined the effects of competitors in plasma (i.e., large neutral amino acids, LNAA) on the transport across the blood-brain-barrier and decarboxylation of tracer FDOPA in human striatum. We studied 10 healthy, neurologically normal subjects with the Scanditronix PC 2048-15B PET camera for 2 hours following intravenous injection of FDOPA. The subjects were either fasted overnight (n=6, ages:23-42 years) or received protein rich diet ({approximately}50 g protein) 1 hour before the study (n=4, ages:21-40 years). During the study, we obtained time-courses of radioactivity in arterial plasma and separated FDOPA and O-methyl-fluoro-DOPA with HPLC. We estimated, by means of least-squares optimization, the unidirectional blood-brain D clearance (K{sub 1}{sup D}), relative DOPA decarboxylase activity (k{sub 3}{sup D}), and effective vascular volume (V{sub 0}) in striatum while the partition volume (V{sub e}=K{sub 1}/k2) was set to the individual`s estimates of frontal lobe. The net clearance (K{sup D}) was calculated as K{sub 1}{sup D}k{sub 3}{sup D}/(k{sub 2}{sup D}+k{sub 3}{sup D}).

  1. FDG-PET findings in the Wernicke-Korsakoff syndrome.

    PubMed

    Reed, Laurence J; Lasserson, Dan; Marsden, Paul; Stanhope, Nicola; Stevens, Tom; Bello, Fernando; Kingsley, Derek; Colchester, Alan; Kopelman, Michael D

    2003-01-01

    This study reports FDG-PET findings in Wernicke-Korsakoff patients. Twelve patients suffering amnesia arising from the Korsakoff syndrome were compared with 10 control subjects without alcohol-related disability. Subjects received [18F]-fluorodeoxyglucose (FDG-PET) imaging as well as neuropsychological assessment and high-resolution MR imaging with volumetric analysis. Volumetric MRI analysis had revealed thalamic and mamillary body atrophy in the patient group as well as frontal lobe atrophy with relative sparing of medial temporal lobe structures. Differences in regional metabolism were identified using complementary region of interest (ROI) and statistical parametric mapping (SPM) approaches employing either absolute methods or a reference region approach to increase statistical power. In general, we found relative hypermetabolism in white matter and hypometabolism in subcortical grey matter in Korsakoff patients. When FDG uptake ratios were examined with occipital lobe metabolism as covariate reference region, Korsakoff patients showed widespread bilateral white matter hypermetabolism on both SPM and ROI analysis. When white matter metabolism was the reference covariate; Korsakoff patients showed relative hypometabolism in the diencephalic grey matter, consistent with their known underlying neuropathology, and medial temporal and retrosplenial hypometabolism, interpreted as secondary metabolic effects within the diencephalic-limbic memory circuits. There was also evidence of a variable degree of more general frontotemporal neocortical hypometabolism on some, but not all, analyses.

  2. Candida Esophagitis Incidentally Detected by 18F-FDG PET/CT in Metastatic Lung Adenocarcinoma

    PubMed Central

    Martínez-Amador, N; Martínez-Rodríguez, I; Quirce, R; Jiménez-Bonilla, J; Banzo, I

    2017-01-01

    The diagnostic significance of esophageal 18F-FDG uptake in oncologic patient is challenging. It may represent normal physiological uptake, inflammation, infection, or neoplasia. We present a patient with a recent diagnosis of non-small cell lung cancer stage IV and esophageal mild uptake on 18F-FDG PET/CT scan. Biopsy of esophageal mucosa demonstrated Candida esophagitis.

  3. Plasmacytoma of the ovary: additional role of 18F-FDG PET/CT.

    PubMed

    Santhosh, Sampath; Mittal, Bhagwant Rai; Raveendran, Ainharan; Jain, Vanita; Nijhawan, Raje; Kumar, Ritesh; Bhattacharya, Anish; Sharma, Suresh C

    2013-05-01

    We report a case of ovarian plasmacytomas where 18F-FDG PET/CT helped in staging by demonstrating increased FDG uptake limited to the ovary, and hence, surgical treatment was carried out as the disease was localized to the ovary.

  4. Effect of simulated in-flight thrust reversing on vertical-tail loads of F-18 and F-15 airplane models. [conducted in the Langley 16-foot transonic tunnel

    NASA Technical Reports Server (NTRS)

    Bare, E. A.; Berrier, B. L.; Capone, F. J.

    1981-01-01

    Investigations were conducted in the Langley 16-Foot Transonic Tunnel to provide data on a 0.10-scale model of the prototype F-18 airplane and a 0.047-scale model of the F-15 three-surface configuration (canard, wing, and horizontal tails). Test data were obtained at static conditions and at Mach numbers from 0.6 to 1.2 over an angle-of-attack range from 2 deg to 15 deg. Nozzle pressure ratio was varied from jet off to about 8.0.

  5. Parallel ICA of FDG-PET and PiB-PET in three conditions with underlying Alzheimer's pathology.

    PubMed

    Laforce, Robert; Tosun, Duygu; Ghosh, Pia; Lehmann, Manja; Madison, Cindee M; Weiner, Michael W; Miller, Bruce L; Jagust, William J; Rabinovici, Gil D

    2014-01-01

    AD-visuospatial (bilateral occipito-parieto-temporal [AUC 0.85, p = 0.009] and right posterior cingulate cortex [PCC]/precuneus and right lateral parietal [AUC 0.69, p = 0.045]). The AD-memory associated component included predominantly bilateral inferior frontal, cuneus and inferior temporal, and right inferior parietal hypometabolism but did not reach significance (AUC 0.65, p = 0.062). None of the PiB components correlated with clinical group. Joint analysis of PiB and FDG with pICA revealed a correlated component pair, in which increased frontal and decreased PCC/precuneus PiB correlated with decreased FDG in the frontal, occipital and temporal regions (partial r = 0.75, p < 0.0001). Using multivariate data analysis, this study reinforced the notion that clinical phenotype in AD is tightly linked to patterns of glucose hypometabolism but not amyloid deposition. These findings are strikingly similar to those of univariate paradigms and provide additional support in favor of specific involvement of the language network, higher-order visual network, and default mode network in clinical variants of AD. The inverse relationship between Aβ deposition and glucose metabolism in partially overlapping brain regions suggests that Aβ may exert both local and remote effects on brain metabolism. Applying multivariate approaches such as pICA to multimodal imaging data is a promising approach for unraveling the complex relationships between different elements of AD pathophysiology.

  6. Parallel ICA of FDG-PET and PiB-PET in three conditions with underlying Alzheimer's pathology

    PubMed Central

    Laforce, Robert; Tosun, Duygu; Ghosh, Pia; Lehmann, Manja; Madison, Cindee M.; Weiner, Michael W.; Miller, Bruce L.; Jagust, William J.; Rabinovici, Gil D.

    2014-01-01

    AD-visuospatial (bilateral occipito-parieto-temporal [AUC 0.85, p = 0.009] and right posterior cingulate cortex [PCC]/precuneus and right lateral parietal [AUC 0.69, p = 0.045]). The AD-memory associated component included predominantly bilateral inferior frontal, cuneus and inferior temporal, and right inferior parietal hypometabolism but did not reach significance (AUC 0.65, p = 0.062). None of the PiB components correlated with clinical group. Joint analysis of PiB and FDG with pICA revealed a correlated component pair, in which increased frontal and decreased PCC/precuneus PiB correlated with decreased FDG in the frontal, occipital and temporal regions (partial r = 0.75, p < 0.0001). Using multivariate data analysis, this study reinforced the notion that clinical phenotype in AD is tightly linked to patterns of glucose hypometabolism but not amyloid deposition. These findings are strikingly similar to those of univariate paradigms and provide additional support in favor of specific involvement of the language network, higher-order visual network, and default mode network in clinical variants of AD. The inverse relationship between Aβ deposition and glucose metabolism in partially overlapping brain regions suggests that Aβ may exert both local and remote effects on brain metabolism. Applying multivariate approaches such as pICA to multimodal imaging data is a promising approach for unraveling the complex relationships between different elements of AD pathophysiology. PMID:24818077

  7. Altered Brain Glucose Consumption in Cogan's Syndrome

    PubMed Central

    Ruffini, Livia; Ghirardini, Stella; Scarlattei, Maura; Baldari, Giorgio; Cidda, Carla; Gandolfi, Stefano A.; Orsoni, Jelka G.

    2016-01-01

    Purpose. Prospective, controlled cohort study to investigate possible alterations in brain glucose metabolism (CMRglc) in patients with Cogan's syndrome (CS). Patients and Methods. Functional mapping of the CMRglc was obtained by quantitative molecular imaging positron emission tomography, combined with computed tomography (FDG-PET/CT). The patients were divided into three clinical groups: typical CS; atypical CS (ACS); autoimmune inner ear disease (AIED). The unmatched control group (CG) consisted of subjects requiring FDG-PET/CT for an extracranial pathology. Statistical mapping searched areas of significant glucose hypometabolism in all the affected patients (DG) and in each clinical subgroup. The results were compared with those of the CG. Results. 44 patients were enrolled (DG) and assigned to the three study groups: 8 patients to the CS group; 21 patients to the ACS group; and 15 to the AIED group. Sixteen subjects formed the CG group. Areas of significant brain glucose hypometabolism were identified in all the study groups, with the largest number and extension in the DG and CS. Conclusions. This study revealed areas of significantly altered CMRglc in patients with CS (any subform) without neurologic complains and normal conventional neuroimaging. Our results suggest that FDG-PET/CT may represent a very useful tool for the global assessment of patients with Cogan's syndrome. PMID:28050276

  8. Spectrum of the Breast Lesions With Increased 18F-FDG Uptake on PET/CT

    PubMed Central

    Dong, Aisheng; Wang, Yang; Lu, Jianping; Zuo, Changjing

    2016-01-01

    Abstract Interpretation of 18F-FDG PET/CT studies in breast is challenging owing to nonspecific FDG uptake in various benign and malignant conditions. Benign conditions include breast changes in pregnancy and lactation, gynecomastia, mastitis, fat necrosis, fibroadenoma, intraductal papilloma, and atypical ductal hyperplasia. Among malignancies, invasive ductal carcinoma and invasive lobular carcinoma are common histological types of breast carcinoma. Rarely, other unusual histological types of breast carcinomas (eg, intraductal papillary carcinoma, invasive micropapillary carcinoma, medullary carcinoma, mucinous carcinoma, and metaplastic carcinoma), lymphoma, and metastasis can be the causes. Knowledge of a wide spectrum of hypermetabolic breast lesions on FDG PET/CT is essential in accurate reading of FDG PET/CT. The purpose of this atlas article is to demonstrate features of various breast lesions encountered at our institution, both benign and malignant, which can result in hypermetabolism on FDG PET/CT imaging. PMID:26975010

  9. Accuracy of FDG-PET to diagnose lung cancer in a region of endemic granulomatous disease

    PubMed Central

    Deppen, Stephen; Putnam, Joe B.; Andrade, Gabriela; Speroff, Theodore; Nesbitt, Jonathan C.; Lambright, Eric S.; Massion, Pierre P.; Walker, Ron; Grogan, Eric L.

    2011-01-01

    Background 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) is used to evaluate suspicious pulmonary lesions due to its diagnostic accuracy. The southeastern United States has a high prevalence of infectious granulomatous lung disease, and the accuracy of FDGPET may be reduced in this population. We examined the diagnostic accuracy of FDG-PET in patients with known or suspected NSCLC treated at our institution. Methods 279 patients identified through our prospective database, underwent an operation for known or suspected lung cancer. Preoperative FDG-PET in 211 eligible patients was defined by standardized uptake value, SUV > 2.5 or by description (“moderate” or “intense”) as avid. Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and decision diagrams were calculated for FDG-PET in all patients and in patients with indeterminate nodules. Results In all eligible patients (n=211), sensitivity and specificity of FDG-PET were 92% and 40%. Positive and negative predictive values were 86% and 55%. Overall FDG-PET accuracy to diagnose lung cancer was 81%. Preoperative positive likelihood ratio for FDG-PET diagnosis of lung cancer in this population was 1.5 compared to previously published values of 7.1. In 113 indeterminate lesions, 65% had lung cancer and the sensitivity and specificity were 89% and 40% respectively. 24 benign nodules (60%) had false positive FDG-PET scans. 22 of 43 benign nodules (51%) were granulomas. Conclusions In a region with endemic granulomatous diseases, the specificity of FDG-PET for diagnosis of lung cancer was 40%. Clinical decisions and future clinical predictive models for lung cancer must accommodate regional variation of FDG-PET scan results. PMID:21592456

  10. A case of brain and leptomeningeal metastases from urothelial carcinoma of the bladder.

    PubMed

    Erhamamcı, S; Reyhan, M; Altinkaya, N

    2014-01-01

    Brain metastases are unusual from urethelial carcinoma of bladder and particularly the occurrence of leptomeningeal metastases is extremely rare, with few cases described in the literature. We present a case of a 45-year-old man with a rare brain metastases as the first metastatic manifestation secondary to urethelial carcinoma of bladder followed by leptomeningeal metastases without any other organ involvement. Eleven months after the diagnosis of high-grade urethelial carcinoma of bladder (T2N0M0), the patient was detected having brain metastases by MRI. FDG PET/CT images for the metastatic evaluation showed no abnormal FDG uptake elsewhere in the body except the brain. Histopathology examination from brain lesion demonstrated the cerebral lesion to be a metastatic urothelial carcinoma. Two months later, the patient was diagnosed to have leptomeningeal metastases by MRI. Our patient's condition gradually worsened, and he died 3 months after the diagnosis of leptomeningeal metastases.

  11. [(18)F]FDG PET monitoring of tumour response to chemotherapy: does [(18)F]FDG uptake correlate with the viable tumour cell fraction?

    PubMed

    Spaepen, Karoline; Stroobants, Sigrid; Dupont, Patrick; Bormans, Guy; Balzarini, Jan; Verhoef, Gregor; Mortelmans, Luc; Vandenberghe, Peter; De Wolf-Peeters, Christine

    2003-05-01

    Because metabolic changes induced by chemotherapy precede the morphological changes, fluorine-18 fluorodeoxyglucose positron emission tomography ([(18)F]FDG PET) is thought to predict response to therapy earlier and more accurately than other modalities. To be a reliable predictor of response, changes in tumour [(18)F]FDG uptake should reflect changes in viable cell fraction, but little is known about the contribution of apoptotic and necrotic cancer cells and inflammatory tissue to the [(18)F]FDG signal. In a tumour mouse model we investigated the relation between chemotherapy-induced changes in various tumoral components and tumour uptake and size. SCID mice were subcutaneously inoculated in the right thigh with 5 x 10(6) Daudi cells. When the tumour measured 15-20 mm, Endoxan was given intravenously. At different time points [1-15 days (d1-d15) after the injection of Endoxan], ex vivo autoradiography and histopathology were performed in two mice and [(18)F]FDG uptake in the tumour and tumour size were correlated with the different cell fractions measured with flow cytometry in five mice. At d1/d3, similar reductions in [(18)F]FDG uptake and viable tumoral cell fraction were observed and these reductions preceded changes in tumour size. By d8/d10, [(18)F]FDG uptake had stabilised despite a further reduction in viable tumoral cell fraction. At these time points a major inflammatory response was observed. At d15, an increase in viable tumour cells was again observed and this was accurately predicted by an increase in [(18)F]FDG uptake, while the tumour volume remained unchanged. In contrast with variations in tumour volume, [(18)F]FDG is a good marker for chemotherapy response monitoring. However, optimal timing seems crucial since a transient increase in stromal reaction may result in overestimation of the fraction of viable cells.

  12. Activity measurements of the radionuclides 18F and 99mTc for the NMISA, South Africa in the ongoing comparisons BIPM.RI(II)-K4.F-18 and BIPM.RI(II)-K4.Tc-99m

    NASA Astrophysics Data System (ADS)

    Michotte, C.; Nonis, M.; Van Rooy, M. W.; Van Staden, M. J.; Lubbe, J.

    2017-01-01

    In 2015, comparisons of activity measurements of 18F and 99mTc using the Transfer Instrument of the International Reference System (SIRTI) took place at the National Metrology Institute of South Africa (NMISA, South Africa). Ampoules containing about 25 kBq of 18F and 99mTc solutions were measured in the SIRTI for more than two half-lives. The NMISA standardized the activity in the ampoules by ionization chamber measurements traceable to 4π(LS)β-γ coincidence measurements. The comparisons, identifiers BIPM.RI(II)-K4.F-18 and BIPM.RI(II)-K4.Tc-99m, are linked to the corresponding BIPM.RI(II)-K1.F-18 and BIPM.RI(II)-K1.Tc-99m comparisons and degrees of equivalence with the respective key comparison reference values have been evaluated. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  13. Pleuroperitoneal Mesothelioma: A Rare Entity on 18F-FDG PET/CT

    PubMed Central

    Sahoo, Manas Kumar; Mukherjee, Anirban; Girish; Parida, Kumar; Agarwal, Krishan Kant; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

    2017-01-01

    Pleuroperitoneal mesothelioma is an extremely rare entity. Only few cases are reported worldwide. We hereby represent a case of pleural mesothelioma referred for F-18-Fluorodeoxyglucose positron emission tomography/computed tomography for response evaluation. Diffuse F-18-Fluorodeoxyglucose avid peritoneal and omental thickening noted which subsequently turned out to be mesothelial involvement on peritoneal biopsy. This case demonstrates the role of F-18-Fluorodeoxyglucose positron emission tomography/computed tomography in detecting other sites of involvement in case of malignant mesothelioma. PMID:28242997

  14. Human radiation dosimetry of 6-[{sup 18}F]FDG predicted from preclinical studies

    SciTech Connect

    Muzic, Raymond F.; Chandramouli, Visvanathan; Hatami, Ahmad; Huang, Hsuan-Ming; Wu, Chunying; Ismail-Beigi, Faramarz

    2014-03-15

    Purpose: The authors are developing 6-[{sup 18}F]fluoro-6-deoxy-D-glucose (6-[{sup 18}F]FDG) as an in vivo tracer of glucose transport. While 6-[{sup 18}F]FDG has the same radionuclide half-life as 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (2-[{sup 18}F]FDG) which is ubiquitously used for PET imaging, 6-[{sup 18}F]FDG has special biologic properties and different biodistributions that make it preferable to 2-[{sup 18}F]FDG for assessing glucose transport. In preparation for 6-[{sup 18}F]FDG use in human PET scanning, the authors would like to determine the amount of 6-[{sup 18}F]FDG to inject while maintaining radiation doses in a safe range. Methods: Rats were injected with 6-[{sup 18}F]FDG, euthanized at specified times, and tissues were collected and assayed for activity content. For each tissue sample, the percent of injected dose per gram was calculated and extrapolated to that for humans in order to construct predicted time-courses. Residence times were calculated as areas under the curves and were used as inputs to OLINDA/EXM in order to calculate the radiation doses. Results: Unlike with 2-[{sup 18}F]FDG for which the urinary bladder wall receives the highest absorbed dose due to urinary excretion, with 6-[{sup 18}F]FDG there is little urinary excretion and osteogenic cells and the liver are predicted to receive the highest absorbed doses: 0.027 mGy/MBq (0.100 rad/mCi) and 0.018 mGy/MBq (0.066 rad/mCi), respectively. Also, the effective dose from 6-[{sup 18}F]FDG, i.e., 0.013 mSv/MBq (0.046 rem/mCi), is predicted to be approximately 30% lower than that from 2-[{sup 18}F]FDG. Conclusions: 6-[{sup 18}F]FDG will be safe for use in the PET scanning of humans.

  15. Controversies on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma.

    PubMed

    Adams, Hugo J A; Kwee, Thomas C

    2016-12-01

    Hodgkin lymphoma, even in advanced-stage, is a highly curable malignancy, but treatment is associated with short-term toxicity and long-term side effects. Early predictive markers are required to identify those patients who do not require the full-length standard therapy (and thus qualify for therapy de-escalation) and those patients who will not be cured by standard therapy (and thus qualify for therapy escalation). Multiple trials have assessed the value of (18) F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) after a few cycles of chemotherapy (also known as 'interim FDG-PET') in predicting outcome in advanced-stage Hodgkin lymphoma. Furthermore, multiple interim FDG-PET-adapted trials, in which patients with positive interim FDG-PET scans are assigned to escalated therapies, and patients with negative interim FDG-PET scans are assigned to de-escalated therapies, have recently been published or are currently ongoing, with generally heterogeneous results. The present article reports the currently available evidence (and controversies) on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma in patients with positive and negative interim FDG-PET findings following continuation of standard chemotherapy or escalated/de-escalated therapy.

  16. Focal Colonic FDG Activity with PET/CT: Guidelines for Recommendation of Colonoscopy

    PubMed Central

    Liu, Tianye; Behr, Spencer; Khan, Sana; Osterhoff, Robert; Aparici, Carina Mari

    2015-01-01

    Focal 18F-fluorodeoxyglucose (FDG) colonic activity can be incidentally seen in positron emission tomography/computed tomography (PET/CT) scans. Its clinical significance is still unclear. The purpose of this study was to assess the significance of focal FDG activity in PET/CT scans by correlating the imaging findings to colonoscopy results, and come up with some guidelines for recommendation of follow-up colonoscopy. A total of 133 patients who underwent both 18F-FDG PET/CT for different oncological indications and colonoscopy within 3 months were retrospectively studied. Imaging, colonoscopy and pathology results were analyzed. Of the 133 FDG-PET/CT scans, 109/133 (82%) did not show focal colonic FDG activity, and 24/133 (18%) did. Of the 109/133 PET/CTs without focal colonic FDG activity, 109/109 (100%) did not have evidence of colon cancer after colonoscopy and histology. Of the 24/133 PET/CTs with focal colonic FDG activity, 10/24 (42%) had pathologic confirmation of colon cancer and 14/24 (58%) did not have evidence of colon cancer after colonoscopy and histological analysis. Sensitivity was 10/10 (100%), specificity 109/123 (89%), positive predictive value (PPV) 10/24 (42%) and negative predictive value (NPV) 109/109 (100%). Incidental focal 18FDG activity in PET/CT imaging shows a high sensitivity, specificity and NPV for malignancy, with a not so high PPV of 42%. Although some people would argue that a 42% chance of malignancy justifies colonoscopy, this maybe is not possible in all cases. However, the high sensitivity of the test does not allow these studies to be overlooked. We provide our recommendations as per when to send patients with focal FDG colonic activity to have further characterization with colonoscopy. PMID:25709541

  17. Fluorodeoxyglucose positron emission tomography (FDG-PET) for monitoring lymphadenopathy in the autoimmune lymphoproliferative syndrome (ALPS).

    PubMed

    Rao, V Koneti; Carrasquillo, Jorge A; Dale, Janet K; Bacharach, Stephen L; Whatley, Millie; Dugan, Faith; Tretler, Jean; Fleisher, Thomas; Puck, Jennifer M; Wilson, Wyndham; Jaffe, Elaine S; Avila, Nilo; Chen, Clara C; Straus, Stephen E

    2006-02-01

    Autoimmune lymphoproliferative syndrome (ALPS) is associated with mutations that impair the activity of lymphocyte apoptosis proteins, leading to chronic lymphadenopathy, hepatosplenomegaly, autoimmunity, and an increased risk of lymphoma. We investigated the utility of fluorodeoxyglucose positron emission tomography (FDG-PET) in discriminating benign from malignant lymphadenopathy in ALPS. We report that FDG avidity of benign lymph nodes in ALPS can be high and, hence, by itself does not imply presence of lymphoma; but FDG-PET can help guide the decision for selecting which of many enlarged nodes in ALPS patients to biopsy when lymphoma is suspected.

  18. Cat-Scratch Disease: A Pitfall for Lymphoma Evaluation by FDG-PET/CT.

    PubMed

    Dubreuil, Julien; Dony, Arthur; Salles, Gilles; Traverse-Glehen, Alexandra; Giammarile, Francesco; Skanjeti, Andrea

    2017-02-01

    FDG-PET/CT is a standard of care in staging and response assessment of Hodgkin lymphoma. Hence, it is important to recognize pitfalls owing to the potential therapeutic impact. We report a case of a 29-year-old woman affected by stage III bulky Hodgkin lymphoma. The interim FDG-PET/CT showed a complete metabolic response. After three new cycles of chemotherapy, the patient showed fever and lymphadenopathy at clinic examination, PET/CT revealed several FDG uptakes at lymph nodes in inguinal and iliac region. Pathologic analyses, after biopsy and serologic examinations, led to the diagnosis of cat-scratch disease.

  19. Abdomen: normal variations and benign conditions resulting in uptake on FDG-PET/CT.

    PubMed

    Zukotynski, Katherine; Kim, Chun K

    2014-04-01

    The increasing use of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in oncology has led to: improved sensitivity and specificity in detecting localized and metastatic disease, increased ability to target biopsies to the site of most aggressive disease, and development of a noninvasive biomarker to assess prognosis and effects of therapy. However, for correct interpretation of FDG-PET/CT studies, an understanding of both normal and abnormal imaging appearances commonly encountered in oncology patients is important. This article discusses commonly seen normal variations and benign findings on FDG-PET/CT of the abdomen.

  20. Monitoring the Therapy of Extensive Osseous Sarcoidosis With FDG PET/CT.

    PubMed

    Yang, Hua; Numani, Shah; Liu, Shuang

    2017-02-24

    FDG PET/CT was performed in a 47-year-old man to evaluate possible malignancy of the spine revealed by MRI. The PET images revealed numerous focal FDG activity throughout the skeletal system. In addition, multiple foci of the increased activity in the mediastinal and hilar nodes were noted, suggestive of sarcoidosis, which was proven following biopsy. Therapy for sarcoidosis was initiated. In the subsequent 4 follow-up FDG PET/CT scans, the activity in both the bones and mediastinal/hilar regions fluctuated. However, anatomical abnormality in the bones on the CT images was never visualized during the entire clinical course.

  1. A case of gouty arthritis to tophi on 18F-FDG PET/CT imaging.

    PubMed

    Ito, Kimiteru; Minamimoto, Ryogo; Morooka, Miyako; Kubota, Kazuo

    2012-06-01

    We report a case of gouty arthritis with tophi that was evaluated using 18F-fluorodeoxyglucose (FDG) positron emission tomography. A 77-year-old man with a history of gouty attacks was admitted with severe polyarticular pain and fever. 18F-FDG positron emission tomography/CT demonstrated focal uptake at multiple joints, including the juxta-articular soft-tissue-density masses of the elbows, and the bases of bilateral large toes. Gouty arthritis should be considered with focal 18F-FDG uptake in juxta-articular soft-tissue-density masses (tophi) with or without associated erosions.

  2. Abnormal 18 F-FDG and 82 Rb PET Findings in Chagas Heart Disease.

    PubMed

    Salimy, Medhi S; Parwani, Purvi J; Mukai, Kanae; Pampaloni, Miguel Hernandez; Flavell, Robert R

    2017-03-03

    Uptake of the radiopharmaceutical F-FDG visualized by PET imaging can reflect abnormal myocardial inflammation. When utilized in conjunction with other imaging modalities, such as echocardiography, PET F-FDG imaging can help distinguish between active cardiac sarcoidosis and other etiologies of nonischemic cardiomyopathy. We present a case of a 46-year-old man with nonischemic cardiomyopathy and ventricular tachycardia who underwent an echocardiogram suggestive of cardiac Chagas disease. A subsequent F-FDG PET demonstrated abnormal hypermetabolism. The diagnosis was confirmed by positive serologic examination results.

  3. Computer-Aided Diagnosis and Localization of Lateralized Temporal Lobe Epilepsy Using Interictal FDG-PET

    PubMed Central

    Kerr, Wesley T.; Nguyen, Stefan T.; Cho, Andrew Y.; Lau, Edward P.; Silverman, Daniel H.; Douglas, Pamela K.; Reddy, Navya M.; Anderson, Ariana; Bramen, Jennifer; Salamon, Noriko; Stern, John M.; Cohen, Mark S.

    2013-01-01

    Interictal FDG-PET (iPET) is a core tool for localizing the epileptogenic focus, potentially before structural MRI, that does not require rare and transient epileptiform discharges or seizures on EEG. The visual interpretation of iPET is challenging and requires years of epilepsy-specific expertise. We have developed an automated computer-aided diagnostic (CAD) tool that has the potential to work both independent of and synergistically with expert analysis. Our tool operates on distributed metabolic changes across the whole brain measured by iPET to both diagnose and lateralize temporal lobe epilepsy (TLE). When diagnosing left TLE (LTLE) or right TLE (RTLE) vs. non-epileptic seizures (NES), our accuracy in reproducing the results of the gold standard long term video-EEG monitoring was 82% [95% confidence interval (CI) 69–90%] or 88% (95% CI 76–94%), respectively. The classifier that both diagnosed and lateralized the disease had overall accuracy of 76% (95% CI 66–84%), where 89% (95% CI 77–96%) of patients correctly identified with epilepsy were correctly lateralized. When identifying LTLE, our CAD tool utilized metabolic changes across the entire brain. By contrast, only temporal regions and the right frontal lobe cortex, were needed to identify RTLE accurately, a finding consistent with clinical observations and indicative of a potential pathophysiological difference between RTLE and LTLE. The goal of CADs is to complement – not replace – expert analysis. In our dataset, the accuracy of manual analysis (MA) of iPET (∼80%) was similar to CAD. The square correlation between our CAD tool and MA, however, was only 30%, indicating that our CAD tool does not recreate MA. The addition of clinical information to our CAD, however, did not substantively change performance. These results suggest that automated analysis might provide clinically valuable information to focus treatment more effectively. PMID:23565107

  4. (18)F-FDG positron emission tomography/computed tomography and (99m)Tc-MDP skeletal scintigraphy in a case of Erdheim-Chester disease.

    PubMed

    Asabella, Artor Niccoli; Cimmino, Antonietta; Altini, Corinna; Notaristefano, Antonio; Rubini, Giuseppe

    2011-01-01

    Erdheim-Chester disease (ECD), first described by Jakob Erdheim and William Chester in 1930, is a rare form of non-Langerhan's cell histiocytosis with unknown aetiology, is charaterized by systemic xanthogranulomatous infiltrative disease. To date, about 350 cases of ECD have been described in the medical literature. The typical ECD diagnostic triad is bone pain, diabetes insipidus and bilateral exophthalmos. A 24 years old man came at our attention for polydipsia with nocturnal and diurnal polyuria, anorexia, febrile episodes (38(o)C), and arthromyalgia especially in the knees. Physical examination showed bilateral periorbital xanthelasma. Blood exams showed increase of plasma osmolarity, haematocrit, sodium and urea and decrease of potassium. Urine exams showed just decreased urine specific gravity, (1.001;normal range: 1.010-1.030) suggestive for central diabetes insipidus (CDI). Brain magnetic resonance with gadolinium enhancement showed the presence of multiple hyperintense lesions expecially in neurohypophysis (swollen and with markedly contrast enhancement). All these data raised the suspision of neurosarcoidosis, so a chest and abdomen contrast enhancement computed tomography was performed, which didn't show abnormalities, making less possible the diagnosis of sarcoidosis. Two weeks later, whole-body (from head to pelvis) plus lower limbs 18-fluorine-labelled 2-deoxy-2-fluoro-D-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) was performed. Uptake of (18)F-FDG was observed in the upper portion of the midbrain area (SUV(max) 7.1) and the pituitary gland (SUV(max) 7.3), and diffuse bone marrow uptake of (18)F-FDG in the proximal epiphysis and metaphysis of both humeri and thigh bones (SUV(max) 6.5), shoulder blades, pelvis bones and the L2 vertebral body (SUV(max) 3.9). This (18)F-FDG PET/CT confirmed the presence of brain lesion seen in MRI , the absence of visceral lesions, but also showed the presence of an atypical bone uptake

  5. Sparse brain network using penalized linear regression

    NASA Astrophysics Data System (ADS)

    Lee, Hyekyoung; Lee, Dong Soo; Kang, Hyejin; Kim, Boong-Nyun; Chung, Moo K.

    2011-03-01

    Sparse partial correlation is a useful connectivity measure for brain networks when it is difficult to compute the exact partial correlation in the small-n large-p setting. In this paper, we formulate the problem of estimating partial correlation as a sparse linear regression with a l1-norm penalty. The method is applied to brain network consisting of parcellated regions of interest (ROIs), which are obtained from FDG-PET images of the autism spectrum disorder (ASD) children and the pediatric control (PedCon) subjects. To validate the results, we check their reproducibilities of the obtained brain networks by the leave-one-out cross validation and compare the clustered structures derived from the brain networks of ASD and PedCon.

  6. Gapless spin liquid ground state in the S = 1/2 vanadium oxyfluoride kagome antiferromagnet [NH4]2[C7H14N][V7O6F18].

    PubMed

    Clark, L; Orain, J C; Bert, F; De Vries, M A; Aidoudi, F H; Morris, R E; Lightfoot, P; Lord, J S; Telling, M T F; Bonville, P; Attfield, J P; Mendels, P; Harrison, A

    2013-05-17

    The vanadium oxyfluoride [NH(4)](2)[C(7)H(14)N][V(7)O(6)F(18)] (DQVOF) is a geometrically frustrated magnetic bilayer material. The structure consists of S = 1/2 kagome planes of V(4+) d(1) ions with S = 1 V(3+) d(2) ions located between the kagome layers. Muon spin relaxation measurements demonstrate the absence of spin freezing down to 40 mK despite an energy scale of 60 K for antiferromagnetic exchange interactions. From magnetization and heat capacity measurements we conclude that the S = 1 spins of the interplane V(3+) ions are weakly coupled to the kagome layers, such that DQVOF can be viewed as an experimental model for S = 1/2 kagome physics, and that it displays a gapless spin liquid ground state.

  7. Electron-tracking Compton gamma-ray camera for small animal and phantom imaging

    NASA Astrophysics Data System (ADS)

    Kabuki, Shigeto; Kimura, Hiroyuki; Amano, Hiroo; Nakamoto, Yuji; Kubo, Hidetoshi; Miuchi, Kentaro; Kurosawa, Shunsuke; Takahashi, Michiaki; Kawashima, Hidekazu; Ueda, Masashi; Okada, Tomohisa; Kubo, Atsushi; Kunieda, Etuso; Nakahara, Tadaki; Kohara, Ryota; Miyazaki, Osamu; Nakazawa, Tetsuo; Shirahata, Takashi; Yamamoto, Etsuji; Ogawa, Koichi; Togashi, Kaori; Saji, Hideo; Tanimori, Toru

    2010-11-01

    We have developed an electron-tracking Compton camera (ETCC) for medical use. Our ETCC has a wide energy dynamic range (200-1300 keV) and wide field of view (3 sr), and thus has potential for advanced medical use. To evaluate the ETCC, we imaged the head (brain) and bladder of mice that had been administered with F-18-FDG. We also imaged the head and thyroid gland of mice using double tracers of F-18-FDG and I-131 ions.

  8. Enhanced regional brain metabolic responses to benzodiazepines in cocaine abusers

    SciTech Connect

    Volkow, N.D.; Wang, G.J.; Fowler, J.S.

    1997-05-01

    While dopamine (DA) appears to be crucial for cocaine reinforcement, its involvement in cocaine addiction is much less clear. Using PET we have shown persistent reductions in striatal DA D2 receptors (which arc predominantly located on GABA cells) in cocaine abusers. This finding coupled to GABA`s role as an effector for DA led us to investigate if there were GABAergic abnormalities in cocaine abusers. In this study we measured regional brain metabolic responses to lorazepam, to indirectly assess GABA function (benzodiazepines facilitate GABAergic neurotransmission). Methods: The experimental subjects consisted of 12 active cocaine abusers and 32 age matched controls. Each subject underwent two PET FDG scans obtained within 1 week of each other. The first FDG scan was obtained after administration of placebo (3 cc of saline solution) given 40-50 minutes prior to FDG; and the second after administration of lorazepam (30 {mu}g/kg) given 40-50 minutes prior to FDG. The subjects were blind to the drugs received. Results: Lorazepam-induced sleepiness was significantly greater in abusers than in controls (p<0.001). Lorazepam-induced decreases in brain glucose metabolism were significantly larger in cocaine abusers than in controls. Whereas in controls whole brain metabolism decreased 13{+-}7 %, in cocaine abusers it decreased 21{+-}13 % (p < 0.05). Lorazepam-induced decrements in regional metabolism were significantly larger in striatum (p < 0.0 1), thalamus (p < 0.01) and cerebellum (p < 0.005) of cocaine abusers than of controls (ANOVA diagnosis by condition (placebo versus lorazepam) interaction effect). The only brain region for which the absolute metabolic changes-induced by lorazepam in cocaine abusers were equivalent to those in controls was the orbitofrontal cortex. These results document an accentuated sensitivity to benzodiazepines in cocaine abusers which is compatible with disrupted GABAergic function in these patients.

  9. Voxel-based analysis of Alzheimer's disease PET imaging using a triplet of radiotracers: PIB, FDDNP, and FDG.

    PubMed

    Shin, Jonghan; Lee, Sang-Yoon; Kim, Seog Ju; Kim, So-Hee; Cho, Seong-Jin; Kim, Young-Bo

    2010-08-15

    Beta amyloid plaques, neurofibrillary tangles, and impaired glucose metabolism are among the most prevalent pathological characteristics of Alzheimer's disease (AD). However, separate visualization of these three AD-related pathologies in living humans has not been conducted. Here, we show that positron emission tomography (PET) imaging using the three radiotracers (11)C-Pittsburgh compound B (PIB), 2-(1-{6-[(2-(18)F-fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene) malononitrile (FDDNP), and 2-[18F]fluoro-2-deoxy-d-glucose (FDG), in the same subjects, with and without AD, can provide valuable information on the pathological patterns of the distribution of tracers for amyloid plaque, neurofibrillary tangle, and glucose hypometabolism in AD. Voxel-based analysis of PIB-PET in patients with AD compared with normal control subjects showed that patients with AD have highly significant PIB retention in brain regions known to have high amyloid plaque deposition (e.g., frontal, parietal, temporal, and posterior cingulate/precuneus cortices). In contrast, voxel-based analysis of FDDNP-PET showed significantly high FDDNP binding in some brain regions known to have high tangle accumulation in patients with AD compared with age-matched normal subjects (e.g., entorhinal cortex, inferior temporal gyrus, and secondary visual cortex). In addition, because FDDNP binds both plaques and tangles but PIB binds plaques specifically, we examined subtracted PET data (FDDNP minus PIB) acquired from the same patients with AD using an SPM analysis. We found that the hippocampal formation was the most significant brain region in the voxel mapping of FDDNP minus PIB in the same patients with AD. Voxel-based analysis of FDG-PET in the same subjects revealed that brain regions with glucose hypometabolism in patients with AD overlap with regions of high PIB binding. In conclusion, PET imaging using these three radiotracers in the same subjects may contribute toward developing and testing disease

  10. Discussion on the alteration of FDG uptake by the breast according to the menstrual cycle in 18F-FDG PET/CT

    NASA Astrophysics Data System (ADS)

    Park, H. H.; Park, M. S.; Lee, C. H.; Cho, J. H.; Dong, K. R.; Chung, W. K.

    2012-09-01

    18F-FDG (fluorodeoxyglucose) PET (positron emission tomography)/CT (computed tomography) is a useful modality for identifying high-glucose-consuming cells, such as cancer cells, by the glucose metabolism of FDG. FDG is taken up by cancer and inflammatory cells, but occasionally there is also some FDG uptake by normal tissues as a result of their individual physiological characteristics. In particular, in fertile females, unusual FDG uptake in the breast changes according to the stages in the menstrual cycle, which can adversely affect a diagnosis. Therefore, this study examined the change in breast FDG uptake in the menstrual cycle on 18F-FDG PET/CT. One hundred and sixty females (34±3.5 years old), who had not undergone a gynecologic anamnesis and had a regular menstrual cycle over the previous 6 months, were examined from March 2010 to February 2011. The subjects were divided into the following four groups (each with 40 patients): flow phase, proliferative phase, ovulatory phase and secretory phase using Pregnancy Calculator Ver. 0.14 and history taking. Discovery Ste was used as the PET/CT. The standardized uptake values (SUVs) on the accumulated region on the breast were analyzed, and three nuclear medicine specialists performed a blind test. The SUVs on the breast were the flow phase (1.64±0.25), proliferative phase (0.93±0.28), ovulatory phase (1.66±0.26) and secretory phase (1.77±0.28). A high uptake value was observed in the secretory, flow and ovulatory phases. The FDG accumulation of the breast was divided into the following three grades compared with the lung and liver by gross analysis: the breast uptake was equal to the lung (Grade I), between the lung and liver (Grade II) and equal to or greater than the liver (Grade III). These results showed a high uptake value in the secretory, flow and ovulatory phases. In fertile females, the FDG uptake of the breast showed changes according to the menstrual cycle, which can be used to improve the diagnosis

  11. Clinical implications of defining the gross tumor volume with combination of CT and {sup 18}FDG-positron emission tomography in non-small-cell lung cancer

    SciTech Connect

    Grills, Inga S. . E-mail: igrills@beaumont.edu; Yan Di; Black, Quinten C.; Wong, Ching-Yee O.; Martinez, Alvaro A.; Kestin, Larry L.

    2007-03-01

    Purpose: To compare the planning target volume (PTV) definitions for computed tomography (CT) vs. positron emission tomography (PET) in non-small-cell lung cancer (NSCLC). Methods and Materials: A total of 21 patients with NSCLC underwent three-dimensional conformal radiotherapy planning. All underwent a staging F-18 fluorodeoxyglucose-position emission tomography ({sup 18}FDG-PET) scan and underwent treatment simulation using CT plus a separate planning {sup 18}FDG-PET scan. Three sets of target volumes were defined: Set 1, CT volumes (CT tumor + staging PET nodal disease); Set 2, PET volumes (planning PET tumor {l_brace}gross tumor volume (GTV) = [(0.3069 x mean standardized uptake value) + 0.5853]){r_brace}; Set 3, composite CT-PET volumes (fused CT-PET tumor). Sets 1 and 2 were compared using a matching index. Three-dimensional conformal radiotherapy plans were created using the Set 1 (CT) volumes; and coverage of the Set 3 (composite) volumes was evaluated. Separate three-dimensional conformal radiotherapy plans were designed for the Set 3 volumes. Results: For the primary tumor GTV, the Set 1 (CT) volume was larger than the Set 2 (PET) volume in 48%, smaller in 33%, and equal in 19%. The mean matching index was 0.65 (35% CT-PET mismatch). Although quantitatively similar, the volumes differed qualitatively. The Set 3 (composite) volume was larger than either CT or PET alone in 62%, smaller in 24%, and equal in 14%. The dose-volume histogram parameters did not differ among the plans for Set 1 (CT) vs. Set 3 (composite) volumes. Small portions of the Set 3 PTV were significantly underdosed in 40% of cases using the CT-only plan. Conclusion: Computed tomography and PET are complementary and should be obtained in the treatment position and fused to define the GTV for NSCLC. Although the quantitative absolute target volume is sometimes similar, the qualitative target locations can be substantially different, leading to underdosage of the target when planning is

  12. S-values calculated from a tomographic head/brain model for brain imaging

    NASA Astrophysics Data System (ADS)

    Chao, Tsi-chian; Xu, X. George

    2004-11-01

    A tomographic head/brain model was developed from the Visible Human images and used to calculate S-values for brain imaging procedures. This model contains 15 segmented sub-regions including caudate nucleus, cerebellum, cerebral cortex, cerebral white matter, corpus callosum, eyes, lateral ventricles, lenses, lentiform nucleus, optic chiasma, optic nerve, pons and middle cerebellar peduncle, skull CSF, thalamus and thyroid. S-values for C-11, O-15, F-18, Tc-99m and I-123 have been calculated using this model and a Monte Carlo code, EGS4. Comparison of the calculated S-values with those calculated from the MIRD (1999) stylized head/brain model shows significant differences. In many cases, the stylized head/brain model resulted in smaller S-values (as much as 88%), suggesting that the doses to a specific patient similar to the Visible Man could have been underestimated using the existing clinical dosimetry.

  13. A Pilot Study Treatment of Malignant Tumors Using [18F] Fluorodeoxyglucose (FDG)

    ClinicalTrials.gov

    2016-08-18

    Radiosensitive Stage IV Solid and Hematological Tumors With High FDG Uptake Not Responding to Standard of Care; Lung Cancer, Head and Neck Cancer, Breast Cancer, Gastric Cancer, Pancreatic Cancer, Colon Cancer, Lymphomas, Sarcomas, Etc

  14. Unusual Horner's Syndrome in Recurrent Breast Cancer: Evaluation Using (18)F-FDG PET/CT.

    PubMed

    Park, Sohyun; Kim, Tae Sung; Kim, Seok-Ki

    2017-03-01

    (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a widely used imaging modality in the initial diagnosis of cancer, treatment response evaluation and detection of recurrence. Herein, we present the case of a 39-year-old female who presented right ptosis on the follow-up of breast cancer after surgery. Clinicians suspected Horner's syndrome, and the patient underwent FDG PET/CT for the evaluation of recurrence that could cause Horner's syndrome. FDG PET/CT demonstrated a focal hypermetabolic lesion in the right cervicothoracic junction area, corresponding to the preganglionic cervical sympathetic trunk. A subsequent needle biopsy was done, and the lesion was confirmed as metastatic ductal carcinoma. In this case, we could detect the exact location of the recurring lesion that caused Horner's syndrome using FDG PET/CT.

  15. Clinical significance of incidental FDG uptake in the prostate gland detected by PET/CT

    PubMed Central

    Sahin, Ertan; Elboga, Umut; Kalender, Ebuzer; Basıbuyuk, Mustafa; Demir, Hasan Deniz; Celen, Yusuf Zeki

    2015-01-01

    The value of FDG-positron emission tomography/computed tomography (PET/CT) for detecting prostate cancer is unknown. We aimed to investigate the clinical value of incidental prostate FDG uptake on PET/CT scans. We reviewed 6128 male patients who underwent FDG-PET/CT scans and selected cases that reported hypermetabolic lesion in the prostate. The patients who have prior history of prostate carcinoma or prostate surgery were excluded from the study. We have analyzed the correlation between PET/CT findings and serum prostate-specific antigen (PSA) levels, imaging (USG), urological examinations and biopsy. Incidental 18F-FDG uptake of the prostate gland was observed in 79 patients (1.3%). While sixteen of them were excluded due to inadequate clinical data, the remaining 63 patients were included for further analysis. The patients were divided into two groups; 8 patients (12.7%) in the malignant group and 55 patients (87.3%) in the benign group. The SUVmax values were not significantly different between the two groups. In 6 (75%) patients with prostate cancer, FDG uptake was observed focally in the peripheral zone of the prostate glands. There was no significant correlation between the SUVmax and the PSA levels. Incidental 18F-FDG uptake in the prostate gland is a rare condition, but a substantial portion of it is associated with the cancer. Benign and malignant lesions of the prostate gland in FDG-PET/CT imaging could not be reliably distinguished. The peripheral focally FDG uptake of prostate glands should be further examined with the clinical and labaratory evaluations. PMID:26379847

  16. A Monte Carlo studies of the entrance foil material in a target assembly for FDG production

    SciTech Connect

    Merouani, A.; El Khayati, N.; EL Ghayour, A.; El Alamy, H.; Zoubir, B.

    2015-07-01

    In this work, a Monte Carlo simulation was performed for different entrance foil Materials in the target assembly for [{sup 18}F] FDG production, to investigate the neutron generations in the entrance foil. However, the objective is to study a materials that has the more or less similar mechanical properties as the Havar{sup R} foil with less generation of secondary particles and without affecting, the yield of FDG production. (authors)

  17. FDG PET/CT Evidence of Effective Treatment of Cardiac Sarcoidosis With Adalimumab.

    PubMed

    Miller, Christina T; Sweiss, Nadera J; Lu, Yang

    2016-05-01

    A 53-year-old man with mediastinal lymph node biopsy and cardiac MRI-proven cardiac sarcoidosis (CS) received treatment with pacemaker and steroids. FDG PET/CT showed active CS despite treatment with prednisone and methotrexate. Addition of weekly adalimumab (Humira) injections was introduced for 3 months. Follow-up FDG PET/CT showed complete resolution of CS as well as improvement of other sarcoid lesions in the thoracic lymph nodes.

  18. Askin tumor: CT and FDG-PET/CT imaging findings and follow-up.

    PubMed

    Xia, Tingting; Guan, Yubao; Chen, Yongxin; Li, Jingxu

    2014-07-01

    The aim of the study was to describe the imaging findings of Askin tumors on computed tomography (CT) and fluorine 18 fluorodeoxyglucose-positron emission tomography (FDG-PET/CT).Seventeen cases of Askin tumors confirmed by histopathology were retrospectively analyzed in terms of CT (17 cases) and FDG-PET/CT data (6 cases).Fifteen of the tumors were located in the chest wall and the other 2 were in the anterior middle mediastinum. Of the 15 chest wall cases, 13 demonstrated irregular, heterogeneous soft tissue masses with cystic degeneration and necrosis, and 2 demonstrated homogeneous soft tissue masses on unenhanced CT scans. Two mediastinal tumors demonstrated the irregular, heterogeneous soft tissue masses. Calcifications were found in 2 tumors. The tumors demonstrated heterogeneously enhancement in 16 cases and homogeneous enhancement in 1 case on contrast-enhanced scans. FDG-PET/CT images revealed increased metabolic activity in all 6 cases undergone FDG-PET/CT scan, and the lesion SUVmax ranged from 4.0 to 18.6. At initial diagnosis, CT and FDG-PET/CT scans revealed rib destruction in 9 cases, pleural effusion in 9 cases, and lung metastasis in 1 case. At follow-up, 12 cases showed recurrence and/or metastases, 4 cases showed improvement or remained stable, and 1 was lost to follow-up.In summary, CT and FDG-PET/CT images of Askin tumors showed heterogeneous soft tissue masses in the chest wall and the mediastinum, accompanied by rib destruction, pleural effusion, and increased FDG uptake. CT and FDG-PET/CT imaging play important roles in the diagnosis and follow-up of patients with Askin tumors.

  19. Impact of PET-FDG in the diagnosis and therapeutic care of patients presenting with metastases of unknown primary.

    PubMed

    Garin, Etienne; Prigent-Lejeune, Florence; Lesimple, Thierry; Barge, Marie-Luce; Rousseau, Caroline; Devillers, Anne; Bouriel, Catherine; Habiba, Mesbah T; Bernard, Anne-Marie; Bridji, Boumédienne; Resche, Isabelle

    2007-06-01

    We carried out a study to evaluate the contribution of positron emission tomography with (18)F-fluorodeoxyglucose (PET-FDG) in the diagnosis and therapeutic care of patients presenting with metastases of unknown primary. PET-FDG was prospectively performed in 51 patients. The PET-FDG data were confirmed histologically or by a follow-up on average at 13 months. PET-FDG identified the primary in 24 percent of cases, and detected the presence of additional metastases in 41 percent of cases. PET-FDG led to a therapeutic modification for 12 patients (24 percent). Furthermore, the therapeutic impact seems more marked in localized forms than in the multifocal. This broad exploratory study confirms the important role of PET-FDG in the diagnosis and therapeutic management of patients with metastases of unknown primary.

  20. FDG-PET/CT for Monitoring Response of Melanoma to the Novel Oncolytic Viral Therapy Talimogene Laherparepvec.

    PubMed

    Covington, Matthew F; Curiel, Clara N; Lattimore, Lois; Avery, Ryan J; Kuo, Phillip H

    2017-02-01

    61-year-old woman with stage IIIa (T3a N1a M0) left lower leg melanoma with lesions suggestive of in-transit metastases 8 months following wide local excision and femoral nodal dissection. FDG-PET/CT demonstrated 5 FDG-avid in-transit nodal metastases in the distal left leg, confirmed on biopsy. Talimogene laherparepvec (T-VEC) oncolytic immunotherapy consisting of intralesional injections of modified herpes simplex virus-expressing granulocyte-macrophage colony-stimulating factor was completed over 6 months. Subsequent FDG-PET/CT demonstrated reduced or resolved FDG activity in the treated in-transit metastases and a new FDG-avid left thigh in-transit metastasis. FDG-PET/CT can monitor response to T-VEC and potentially other novel viral immunotherapies.

  1. Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) Correlation of Histopathology and MRI in Prion Disease.

    PubMed

    Mente, Karin P; O'Donnell, James K; Jones, Stephen E; Cohen, Mark L; Thompson, Nicolas R; Bizzi, Alberto; Gambetti, Pierluigi; Safar, Jiri G; Appleby, Brian S

    2017-01-01

    Creutzfeldt-Jakob disease (CJD) and other prion diseases are rapidly progressive spongiform encephalopathies that are invariably fatal. Clinical features and magnetic resonance imaging, electroencephalogram, and cerebrospinal fluid abnormalities may suggest prion disease, but a definitive diagnosis can only be made by means of neuropathologic examination. Fluorodeoxyglucose positron emission tomography (FDG-PET) is not routinely used to evaluate patients with suspected prion disease. This study includes 11 cases of definite prion disease in which FDG-PET scans were obtained. There were 8 sporadic CJD cases, 2 genetic CJD cases, and 1 fatal familial insomnia case. Automated FDG-PET analysis revealed parietal region hypometabolism in all cases. Surprisingly, limbic and mesolimbic hypermetabolism were also present in the majority of cases. When FDG-PET hypometabolism was compared with neuropathologic changes (neuronal loss, astrocytosis, spongiosis), hypometabolism was predictive of neuropathology in 80.6% of cortical regions versus 17.6% of subcortical regions. The odds of neuropathologic changes were 2.1 times higher in cortical regions than subcortical regions (P=0.0265). A similar discordance between cortical and subcortical regions was observed between FDG-PET hypometabolism and magnetic resonance imaging diffusion weighted imaging hyperintensity. This study shows that there may be a relationship between FDG-PET hypometabolism and neuropathology in cortical regions in prion disease but it is unlikely to be helpful for diagnosis.

  2. Two years of experience with the [ 18F]FDG production module

    NASA Astrophysics Data System (ADS)

    Kim, Sang Wook; Hur, Min Goo; Chai, Jong-Seo; Park, Jeong Hoon; Yu, Kook Hyun; Jeong, Cheol Ki; Lee, Goung Jin; Min, Young Don; Yang, Seung Dae

    2007-08-01

    Chemistry module for a conventional [18F]FDG production by using tetrabutylammonium bicarbonate (TBA) and an acidic hydrolysis has been manufactured and evaluated. In this experiment, 75 mM (pH 7.5-7.8) of TBA solution and a ca. 2-curies order of [18F]-fluoride have been used for the evaluation. The commercial acidic purification cartridge was purchased from GE or UKE. The operation system (OS) was programmed with Lab-View which was selected because of its easy customization of the OS. Small sized solenoid valves (Burkert; type 6124) were selected to reduce the module dimensions (W 350 × D 270 × H 250). The total time for the synthesis of [18F]FDG was 30 ± 3 min. The production yield of [18F]FDG was 60 ± 2% on an average at EOS, with the decay uncorrected. This experimental data show that the traditional chemistry module can provide a good [18F]FDG production yield by optimizing the operational conditions. The radiochemical purity, radionuclidic purity, acidity, residual solvent, osmolality and endotoxin were determined to assess the quality of [18F]FDG. The examined contents for the quality control of [18F]FDG were found to be suitable for a clinical application.

  3. Science to Practice: Does FDG Differentiate Morphologically Unstable from Stable Atherosclerotic Plaque?

    PubMed

    Dilsizian, Vasken; Jadvar, Hossein

    2017-04-01

    It has been reported that fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) may detect the inflammatory state and macrophage burden of atherosclerotic plaques and potentially identify vulnerable plaques. However, published reports have been inconsistent in this area. Tavakoli et al ( 1 ) hypothesized that differential regulation of macrophage glucose metabolism by macrophage colony-stimulating factor (M-CSF; inflammation resolving) and granulocyte-M-CSF (GM-CSF; proinflammatory) may contribute to the inconsistency of FDG vessel wall inflammation. After the induction of inflammatory and metabolic profiles, both M-CSF and GM-CSF generated comparable levels of glucose uptake in cultured macrophages and murine atherosclerotic plaques. These findings suggest that although FDG uptake is an indicator of vascular macrophage burden (total number of macrophages), it may not necessarily differentiate morphologically unstable (inflammatory) from stable (noninflammatory) atherosclerotic plaque. Moreover, although atherosclerosis is characterized by macrophage-predominated inflammation, there is a wide range of other vascular diseases in which macrophages and inflammation play an important role in the absence of atherosclerosis. FDG uptake will be indistinguishable in atherosclerosis from large-artery inflammatory vascular disease, such as Takayasu arteritis, chemotherapy- or radiation-induced vascular inflammation, or foreign-body reaction, such as synthetic arterial graft. Because of the nonspecific nature of FDG uptake by any cell (upregulated under hypoxic conditions or other microenvironmental factors), this work calls for a more cautious approach to interpreting vascular FDG uptake as indicative of inflammatory atherosclerosis in the clinical setting.

  4. Prognostic value of interim and end-of-treatment FDG-PET in follicular lymphoma: a systematic review.

    PubMed

    Adams, Hugo J A; Nievelstein, Rutger A J; Kwee, Thomas C

    2016-01-01

    This study aimed to systematically review the prognostic value of interim and end-of-treatment (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in follicular lymphoma during and after first-line therapy. The PubMed/MEDLINE database was searched for relevant original studies. Included studies were methodologically assessed, and their results were extracted and descriptively analyzed. Three studies on the prognostic value of interim FDG-PET and eight studies on the prognostic value of end-of-treatment FDG-PET were included. Overall, studies were of poor methodological quality. In addition, there was incomplete reporting of progression-free survival (PFS) and overall survival (OS) data by several studies, and none of the studies incorporated the Follicular Lymphoma International Prognostic Index (FLIPI) in the OS analyses. Two studies reported no significant difference in PFS between interim FDG-PET positive and negative patients, whereas one study reported a significant difference in PFS between the two groups. Two studies reported no significant difference in OS between interim FDG-PET positive and negative patients. Five studies reported end-of-treatment FDG-PET positive patients to have a significantly worse PFS than end-of-treatment FDG-PET negative patients, and one study reported a non-significant trend towards a worse PFS for end-of-treatment FDG-PET positive patients. Three studies reported end-of-treatment FDG-PET positive patients to have a significantly worse OS than end-of-treatment FDG-PET negative patients. In conclusion, the available evidence does not support the use of interim FDG-PET in follicular lymphoma. Although published studies suggest end-of-treatment FDG-PET to be predictive of PFS and OS, they suffer from numerous biases and failure to correct OS prediction for the FLIPI.

  5. The F-18 systems research aircraft facility

    NASA Technical Reports Server (NTRS)

    Sitz, Joel R.

    1992-01-01

    To help ensure that new aerospace initiatives rapidly transition to competitive U.S. technologies, NASA Dryden Flight Research Facility has dedicated a systems research aircraft facility. The primary goal is to accelerate the transition of new aerospace technologies to commercial, military, and space vehicles. Key technologies include more-electric aircraft concepts, fly-by-light systems, flush airdata systems, and advanced computer architectures. Future aircraft that will benefit are the high-speed civil transport and the National AeroSpace Plane. This paper describes the systems research aircraft flight research vehicle and outlines near-term programs.

  6. Repeatability of quantitative FDG-PET/CT and contrast enhanced CT in recurrent ovarian carcinoma: test retest measurements for tumor FDG uptake, diameter and volume

    PubMed Central

    Rockall, Andrea G.; Avril, Norbert; Lam, Raymond; Iannone, Robert; Mozley, P. David; Parkinson, Christine; Bergstrom, Donald; Sala, Evis; Sarker, Shah-Jalal; McNeish, Iain A.; Brenton, James D.

    2014-01-01

    Purpose Repeatability of baseline FDG-PET/CT measurements has not been tested in ovarian cancer. This dual-center, prospective study assessed variation in tumor FDG uptake, tumor diameter (TD) and tumor volume (TV) from sequential FDG-PET/CT and contrast-enhanced CT (CECT) in patients with recurrent platinum-sensitive ovarian cancer. Methods Patients underwent two pre-treatment baseline FDG-PET/CT (n=21) and CECT (n=20) at 2 clinical sites with different PET/CT instruments. Patients were included if they had at least one target lesion (TL) in the abdomen with an SUV maximum (SUVmax) of ≥2.5 and a long axis diameter of ≥15mm. Two independent reading methods were used to evaluate repeatability of TD and SUV uptake: on site and at an imaging clinical research organization (CRO). TV reads were only performed by CRO. In each reading set, TLs were independently measured on sequential imaging. Results Median time between FDG-PET/CT was 2 days (range 1-7). For site reads, concordance correlation coefficient (CCC) for SUVmean, SUVmax and TD were 0.95, 0.94 and 0.99 respectively. Repeatability coefficients were 16.3%, 17.3% and 8.8% for SUVmean, SUVmax and TD respectively. Similar results were observed for CRO reads. TV CCC was 0.99 with a repeatability coefficient of 28.1%. Conclusions There was excellent test/retest repeatability for FDG-PET/CT quantitative measurements across two sites and two independent reading methods. Cut-off values for determining change in SUVmean, SUVmax and TV establish limits to determine metabolic and/or volumetric response to treatment in platinum-sensitive relapsed ovarian cancer. PMID:24573555

  7. Correlation of 18F-FDG Avid Volumes on Pre–Radiation Therapy and Post–Radiation Therapy FDG PET Scans in Recurrent Lung Cancer

    PubMed Central

    Shusharina, Nadya; Cho, Joseph; Sharp, Gregory C.; Choi, Noah C.

    2014-01-01

    Purpose To investigate the spatial correlation between high uptake regions of 2-deoxy-2-[18F]-fluoro-D-glucose positron emission tomography (18F-FDG PET) before and after therapy in recurrent lung cancer. Methods and Materials We enrolled 106 patients with inoperable lung cancer into a prospective study whose primary objectives were to determine first, the earliest time point when the maximum decrease in FDG uptake representing the maximum metabolic response (MMR) is attainable and second, the optimum cutoff value of MMR based on its predicted tumor control probability, sensitivity, and specificity. Of those patients, 61 completed the required 4 serial 18F-FDG PET examinations after therapy. Nineteen of 61 patients experienced local recurrence at the primary tumor and underwent analysis. The volumes of interest (VOI) on pretherapy FDG-PET were defined by use of an isocontour at ≥50% of maximum standard uptake value (SUVmax) (≥50% of SUVmax) with correction for heterogeneity. The VOI on posttherapy images were defined at ≥80% of SUVmax. The VOI of pretherapy and posttherapy 18F-FDG PET images were correlated for the extent of overlap. Results The size of VOI at pretherapy images was on average 25.7% (range, 8.8%-56.3%) of the pretherapy primary gross tumor volume (GTV), and their overlap fractions were 0.8 (95% confidence interval [CI]: 0.7-0.9), 0.63 (95% CI: 0.49-0.77), and 0.38 (95% CI: 0.19-0.57) of VOI of posttherapy FDG PET images at 10 days, 3 months, and 6 months, respectively. The residual uptake originated from the pretherapy VOI in 15 of 17 cases. Conclusions VOI defined by the SUVmax- ≥50% isocontour may be a biological target volume for escalated radiation dose. PMID:24725696

  8. Correlation of {sup 18}F-FDG Avid Volumes on Pre–Radiation Therapy and Post–Radiation Therapy FDG PET Scans in Recurrent Lung Cancer

    SciTech Connect

    Shusharina, Nadya Cho, Joseph; Sharp, Gregory C.; Choi, Noah C.

    2014-05-01

    Purpose: To investigate the spatial correlation between high uptake regions of 2-deoxy-2-[{sup 18}F]-fluoro-D-glucose positron emission tomography ({sup 18}F-FDG PET) before and after therapy in recurrent lung cancer. Methods and Materials: We enrolled 106 patients with inoperable lung cancer into a prospective study whose primary objectives were to determine first, the earliest time point when the maximum decrease in FDG uptake representing the maximum metabolic response (MMR) is attainable and second, the optimum cutoff value of MMR based on its predicted tumor control probability, sensitivity, and specificity. Of those patients, 61 completed the required 4 serial {sup 18}F-FDG PET examinations after therapy. Nineteen of 61 patients experienced local recurrence at the primary tumor and underwent analysis. The volumes of interest (VOI) on pretherapy FDG-PET were defined by use of an isocontour at ≥50% of maximum standard uptake value (SUV{sub max}) (≥50% of SUV{sub max}) with correction for heterogeneity. The VOI on posttherapy images were defined at ≥80% of SUV{sub max}. The VOI of pretherapy and posttherapy {sup 18}F-FDG PET images were correlated for the extent of overlap. Results: The size of VOI at pretherapy images was on average 25.7% (range, 8.8%-56.3%) of the pretherapy primary gross tumor volume (GTV), and their overlap fractions were 0.8 (95% confidence interval [CI]: 0.7-0.9), 0.63 (95% CI: 0.49-0.77), and 0.38 (95% CI: 0.19-0.57) of VOI of posttherapy FDG PET images at 10 days, 3 months, and 6 months, respectively. The residual uptake originated from the pretherapy VOI in 15 of 17 cases. Conclusions: VOI defined by the SUV{sub max}-≥50% isocontour may be a biological target volume for escalated radiation dose.

  9. Applications of 2-deoxy-2-fluoro-D-glucose (FDG) in Plant Imaging: Past, Present, and Future

    PubMed Central

    Fatangare, Amol; Svatoš, Aleš

    2016-01-01

    The aim of this review article is to explore and establish the current status of 2-deoxy-2-fluoro-D-glucose (FDG) applications in plant imaging. In the present article, we review the previous literature on its experimental merits to formulate a consistent and inclusive picture of FDG applications in plant-imaging research. 2-deoxy-2-fluoro-D-glucose is a [18F]fluorine-labeled glucose analog in which C-2 hydroxyl group has been replaced by a positron-emitting [18F] radioisotope. As FDG is a positron-emitting radiotracer, it could be used in in vivo imaging studies. FDG mimics glucose chemically and structurally. Its uptake and distribution are found to be similar to those of glucose in animal models. FDG is commonly used as a radiotracer for glucose in medical diagnostics and in vivo animal imaging studies but rarely in plant imaging. Tsuji et al. (2002) first reported FDG uptake and distribution in tomato plants. Later, Hattori et al. (2008) described FDG translocation in intact sorghum plants and suggested that it could be used as a tracer for photoassimilate translocation in plants. These findings raised interest among other plant scientists, which has resulted in a recent surge of articles involving the use of FDG as a tracer in plants. There have been seven studies describing FDG-imaging applications in plants. These studies describe FDG applications ranging from monitoring radiotracer translocation to analyzing solute transport, root uptake, photoassimilate tracing, carbon allocation, and glycoside biosynthesis. Fatangare et al. (2015) recently characterized FDG metabolism in plants; such knowledge is crucial to understanding and validating the application of FDG in plant imaging research. Recent FDG studies significantly advance our understanding of FDG translocation and metabolism in plants but also raise new questions. Here, we take a look at all the previous results to form a comprehensive picture of FDG translocation, metabolism, and applications in

  10. Concurrent Diffuse Pyelonephritis and Prostatitis: Discordant Findings on Sequential FDG PET/CT and 67Ga SPECT/CT Imaging.

    PubMed

    Lucaj, Robert; Achong, Dwight M

    2017-01-01

    A 45-year-old man underwent FDG PET/CT for initial imaging evaluation of recurrent Escherichia coli urinary tract infections, which demonstrated no significant FDG uptake in either kidney and subtle FDG uptake in the right prostate lobe. Subsequent Ga SPECT/CT demonstrated abnormal intense gallium uptake throughout the right kidney and entire prostate gland, clearly discordant with PET/CT findings and consistent with unexpected concurrent pyelonephritis and prostatitis. Although FDG has effectively replaced Ga in everyday clinical practice, the current case serves as a reminder that there is still a role for Ga in the evaluation of genitourinary infections.

  11. Radiation Changes Do Not Interfere With Postchemoradiation Restaging of Patients With Rectal Cancer by FDG PET/CT Before Curative Surgical Therapy

    SciTech Connect

    Kalff, Victor; Ware, Robert; Heriot, Alexander; Chao, Michael; Drummond, Elizabeth; Hicks, Rodney J.

    2009-05-01

    Purpose: Changes in F-18 fluorodeoxyglucose (FDG) uptake in normal tissues after chemoradiation therapy (CRT) potentially limit the ability of positron emission tomography (PET) to provide early assessment of therapeutic response. This study evaluated whether such changes negatively impact interpretation of posttherapy PET performed within 6 weeks of CRT completion and before definitive surgery in patients with locally advanced rectal cancer. The positive predictive value (PPV) and specificity of post-CRT PET, read clinically, was determined in 63 consecutive rectal cancer patients who had undergone preoperative CRT. Methods and Materials: A schema for identifying and scoring postradiation effects on PET was prospectively defined and applied in a blinded manner. This was compared with initial clinical reporting of response. Histologic assessment of the operative specimens was used as the reference standard. Correlation between clinical proctitis during CRT and radiation changes on subsequent PET was also assessed. Results: Clinical reporting of post-CRT PET yielded a high PPV (94%; 95% confidence interval, 89--100%) but may have been exaggerated by the low prevalence of complete tumor clearance (16%). The specificity was 80% with only two false-positive results. On blinded reading, significant post-CRT effects on PET were recorded in 4 of 63 patients (6% 95% confidence interval, 0-13%), but pattern recognition converted both false-positive PET results to a complete metabolic response. Clinical CRT proctitis was not correlated with PET findings. Conclusion: Postradiation effects do not appear to significantly compromise the interpretation of PET for therapeutic response assessment. The proposed PET pattern of response may further improve the specificity of PET.

  12. Predicting the transition from normal aging to Alzheimer's disease: A statistical mechanistic evaluation of FDG-PET data.

    PubMed

    Pagani, Marco; Giuliani, Alessandro; Öberg, Johanna; Chincarini, Andrea; Morbelli, Silvia; Brugnolo, Andrea; Arnaldi, Dario; Picco, Agnese; Bauckneht, Matteo; Buschiazzo, Ambra; Sambuceti, Gianmario; Nobili, Flavio

    2016-11-01

    The assessment of the degree of order of brain metabolism by means of a statistical mechanistic approach applied to FDG-PET, allowed us to characterize healthy subjects as well as patients with mild cognitive impairment and Alzheimer's Disease (AD). The intensity signals from 24 volumes of interest were submitted to principal component analysis (PCA) giving rise to a major first principal component whose eigenvalue was a reliable cumulative index of order. This index linearly decreased from 77 to 44% going from normal aging to AD patients with intermediate conditions between these values (r=0.96, p<0.001). Bootstrap analysis confirmed the statistical significance of the results. The progressive detachment of different brain regions from the first component was assessed, allowing for a purely data driven reconstruction of already known maximally affected areas. We demonstrated for the first time the reliability of a single global index of order in discriminating groups of cognitively impaired patients with different clinical outcome. The second relevant finding was the identification of clusters of regions relevant to AD pathology progressively separating from the first principal component through different stages of cognitive impairment, including patients cognitively impaired but not converted to AD. This paved the way to the quantitative assessment of the functional networking status in individual patients.

  13. (18)F-FDG PET/CT and functional MRI in a case of crossed logopenic primary progressive aphasia.

    PubMed

    Cabrera-Martín, M N; Matías-Guiu, J A; Yus-Fuertes, M; Valles-Salgado, M; Moreno-Ramos, T; Matías-Guiu, J; Carreras Delgado, J L

    Primary progressive aphasia is a clinical syndrome caused by a neurodegeneration of areas and neural networks involved in language, usually in the left hemisphere. The term "crossed aphasia" denotes an acquired language dysfunction caused by a lesion in the hemisphere ipsilateral to the dominant hand. A case is presented on a 75-year-old right-handed woman with a logopenic variant of primary progressive aphasia with word-finding difficulties of 2 years onset. The (18)F-FDG PET/CT showed right temporoparietal hypometabolism. A functional MRI scan was performed during a verb naming task in order to characterise language lateralisation patterns. A similar activation pattern was observed in both hemispheres, with less activation than expected in bilateral inferior frontal gyrus. These findings support that logopenic variant of primary progressive aphasia should not be considered as a neurodegeneration starting in the left brain hemisphere, but as a syndrome characterised by asymmetric neurodegeneration of brain regions and neural networks involved in language.

  14. Robustness of correlations between PCA of FDG-PET scans and biological variables in healthy and demented subjects.

    PubMed

    Markiewicz, P J; Matthews, J C; Declerck, J; Herholz, K

    2011-05-15

    In neuroimaging it is helpful and useful to obtain robust and accurate estimates of relationships between the image derived data and separately derived covariates such as clinical and demographic measures. Due to the high dimensionality of brain images, complex image analysis is typically used to extract certain image features, which may or may not relate to the covariates. These correlations which explain variance within the image data are frequently of interest. Principal component analysis (PCA) is used to extract image features from a sample of 42 FDG PET brain images (19 normal controls (NCs), 23 Alzheimer's disease (AD) patients). For the first three most robust PCs, the correlation of the PC scores with: i) the Mini Mental Status Exam (MMSE) score and ii) age is examined. The key aspects of this work is the assessment of: i) the robustness and significance of the correlations using bootstrap resampling; ii) the influence of the PCA on the robustness of the correlations; iii) the impact of two intensity normalization methods (global and cerebellum). Results show that: i) Pearson's statistics can lead to overoptimistic results. ii) The robustness of the correlations deteriorate with the number of PCs. iii) The correlations are hugely influenced by the method of intensity normalization: the correlation of cognitive impairment with PC1 are stronger and more significant for global normalization; whereas the correlations with age were strongest and more robust with PC2 and cerebellar normalization.

  15. Central modulation in cluster headache patients treated with occipital nerve stimulation: an FDG-PET study

    PubMed Central

    2011-01-01

    Background Occipital nerve stimulation (ONS) has raised new hope for drug-resistant chronic cluster headache (drCCH), a devastating condition. However its mode of action remains elusive. Since the long delay to meaningful effect suggests that ONS induces slow neuromodulation, we have searched for changes in central pain-control areas using metabolic neuroimaging. Methods Ten drCCH patients underwent an 18FDG-PET scan after ONS, at delays varying between 0 and 30 months. All were scanned with ongoing ONS (ON) and with the stimulator switched OFF. Results After 6-30 months of ONS, 3 patients were pain free and 4 had a ≥ 90% reduction of attack frequency (responders). In all patients compared to controls, several areas of the pain matrix showed hypermetabolism: ipsilateral hypothalamus, midbrain and ipsilateral lower pons. All normalized after ONS, except for the hypothalamus. Switching the stimulator ON or OFF had little influence on brain glucose metabolism. The perigenual anterior cingulate cortex (PACC) was hyperactive in ONS responders compared to non-responders. Conclusions Metabolic normalization in the pain neuromatrix and lack of short-term changes induced by the stimulation might support the hypothesis that ONS acts in drCCH through slow neuromodulatory processes. Selective activation in responders of PACC, a pivotal structure in the endogenous opioid system, suggests that ONS could restore balance within dysfunctioning pain control centres. That ONS is nothing but a symptomatic treatment might be illustrated by the persistent hypothalamic hypermetabolism, which could explain why autonomic attacks may persist despite pain relief and why cluster attacks recur shortly after stimulator arrest. PET studies on larger samples are warranted to confirm these first results. PMID:21349186

  16. Neurometabolic effects of psilocybin, 3,4-methylenedioxyethylamphetamine (MDE) and d-methamphetamine in healthy volunteers. A double-blind, placebo-controlled PET study with [18F]FDG.

    PubMed

    Gouzoulis-Mayfrank, E; Schreckenberger, M; Sabri, O; Arning, C; Thelen, B; Spitzer, M; Kovar, K A; Hermle, L; Büll, U; Sass, H

    1999-06-01

    The neurometabolic effects of the hallucinogen psilocybin (PSI; 0.2 mg/kg), the entactogen 3,4-methylenedioxyethylamphetamine (MDE; 2 mg/kg) and the stimulant d-methamphetamine (METH; 0.2-0.4 mg/kg) and the drugs' interactions with a prefrontal activation task were investigated in a double-blind, placebo-controlled human [F-18]fluorodeoxyglucoseFDG-positron emission tomographicPET study (each group: n = 8). Subjects underwent two scans (control: word repetition; activation word association) within 2-4 weeks. Psilocybin increased rMRGlu in distinct right hemispheric frontotemporal cortical regions, particularly in the anterior cingulate and decreased rMRGlu in the thalamus. Both MDE and METH induced cortical hypometabolism and cerebellar hypermetabolism. In the MDE group, cortical hypometabolism was more pronounced in frontal regions, with the exception of the right anterior cingulate, which tended to be hyperactive. Cognitive activation-related increases in left frontocortical regions were attenuated under all three psychoactive substances, but less so under MDE. Taking into account performance data and subjective reports on task difficulty, these effects may result from different mechanisms across the three groups. Our PSI data are in line with studies on acute schizophrenic patients suggesting frontal overactivity at rest, but diminished capacity to activate prefrontal regions upon cognitive demand. The MDE data support the hypothesis that entactogens constitute a distinct psychoactive substance class, which takes an intermediate position between stimulants and hallucinogens.

  17. HPLC and TLC methods for analysis of [(18)F]FDG and its metabolites from biological samples.

    PubMed

    Rokka, Johanna; Grönroos, Tove J; Viljanen, Tapio; Solin, Olof; Haaparanta-Solin, Merja

    2017-03-24

    The most used positron emission tomography (PET) tracer, 2-[(18)F]fluoro-2-deoxy-d-glucose ([(18)F]FDG), is a glucose analogue that is used to measure tissue glucose consumption. Traditionally, the Sokoloff model is the basis for [(18)F]FDG modeling. According to this model, [(18)F]FDG is expected to be trapped in a cell in the form of [(18)F]FDG-6-phosphate ([(18)F]FDG-6-P). However, several studies have shown that in tissues, [(18)F]FDG metabolism goes beyond [(18)F]FDG-6-P. Our aim was to develop radioHPLC and radioTLC methods for analysis of [(18)F]FDG metabolites from tissue samples. The radioHPLC method uses a sensitive on-line scintillation detector to detect radioactivity, and the radioTLC method employs digital autoradiography to detect the radioactivity distribution on a TLC plate. The HPLC and TLC methods were developed using enzymatically in vitro-produced metabolites of [(18)F]FDG as reference standards. For this purpose, three [(18)F]FDG metabolites were synthesized: [(18)F]FDG-6-P, [(18)F]FD-PGL, and [(18)F]FDG-1,6-P2. The two methods were evaluated by analyzing the [(18)F]FDG metabolic profile from rodent ex vivo tissue homogenates. The HPLC method with an on-line scintillation detector had a wide linearity in a range of 5Bq-5kBq (LOD 46Bq, LOQ 139Bq) and a good resolution (Rs ≥1.9), and separated [(18)F]FDG and its metabolites clearly. The TLC method combined with digital autoradiography had a high sensitivity in a wide range of radioactivity (0.1Bq-2kBq, LOD 0.24Bq, LOQ 0.31Bq), and multiple samples could be analyzed simultaneously. As our test and the method validation with ex vivo samples showed, both methods are useful, and at best they complement each other in analysis of [(18)F]FDG and its radioactive metabolites from biological samples.

  18. Primary Tumor Standardized Uptake Value Measured on F18-Fluorodeoxyglucose Positron Emission Tomography Is of Prediction Value for Survival and Local Control in Non–Small-Cell Lung Cancer Receiving Radiotherapy

    PubMed Central

    Na, Feifei; Wang, Jingwen; Li, Cong; Deng, Lei; Xue, Jianxin

    2014-01-01

    Introduction: The 2-[18F]-Fluorodeoxyglucose (FDG) positron emission tomography (PET/CT) has become an imaging tool for clinical assessment of tumor, node, metastasis in non–small-cell lung cancer (NSCLC). Primary tumor maximum standardized uptake value (SUVmax) on 18F-FDG PET/CT before and after radiation therapy (RT) has been studied as a potential prognostic factor for NSCLC patients receiving radiotherapy. However, the sample sizes of most studies were small, and the results of the prediction value of SUVmax remained undetermined, which lead us to perform a meta-analysis to improve the precision in estimating its effect. Methods: We performed a meta-analysis of published literature for primary tumor SUVmax-based biomarkers of the outcome of NSCLC receiving radiotherapy. The required data for estimation of individual hazard ratios (HRs) to compare patients with a low and a high SUVmax were extracted from each publication. A combined HR was calculated by Stata statistical software (Version 11). All of the results were verified by two persons to ensure its accuracy. Results: Thirteen studies were finally included into this meta-analysis; data are available in 13 studies for pre-RT primary tumor SUVmax and in five studies for post-RT. For overall survival, the combined HR estimate was 1.05 (95% confidence interval [CI], 1.02–1.08) and 1.32 (95% CI, 1.15–1.51) for pre-RT SUVmax and post-RT SUVmax, respectively; 1.26 (95% CI, 1.05–1.52) and 2.01 (95% CI, 1.16–3.46) for local control (LC). In stereotactic body radiotherapy (SBRT) group, HR for LC was 1.11 (95% CI, 1.06–1.18) and 2.19 (95% CI, 1.34–3.60) for pre-SBRT SUVmax and post-SBRT SUVmax, respectively. Conclusion: Both pre-RT and post-RT primary tumor SUVmax can predict the outcome of patients with NSCLC treated with radiotherapy. Patients with high levels of pre-RT SUVmax seemed to have poorer overall survival and LC. PMID:24787963

  19. Flight and full-scale wind-tunnel comparison of pressure distributions from an F-18 aircraft at high angles of attack. [Conducted in NASA Ames Research Center's 80 by 120 ft wind tunnel

    NASA Technical Reports Server (NTRS)

    Fisher, David F.; Lanser, Wendy R.

    1994-01-01

    Pressure distributions were obtained at nearly identical fuselage stations and wing chord butt lines in flight on the F-18 HARV at NASA Dryden Flight Research Center and in the NASA Ames Research Center's 80 by 120 ft wind tunnel on a full-scale F/A-18 aircraft. The static pressures were measured at the identical five stations on the forebody, three stations on the left and right leading-edge extensions, and three spanwise stations on the wing. Comparisons of the flight and wind-tunnel pressure distributions were made at alpha = 30 deg, 45 deg, and 60 deg/59 deg. In general, very good agreement was found. Minor differences were noted at the forebody at alpha = 45 deg and 60 deg in the magnitude of the vortex footprints and a Mach number effect was noted at the leading-edge extension at alpha = 30 deg. The inboard leading edge flap data from the wind tunnel at alpha = 59 deg showed a suction peak that did not appear in the flight data. This was the result of a vortex from the corner of the leading edge flap whose path was altered by the lack of an engine simulation in the wind tunnel.

  20. The Role of 18F-FDG PET/CT Integrated Imaging in Distinguishing Malignant from Benign Pleural Effusion

    PubMed Central

    Sun, Yajuan; Yu, Hongjuan; Ma, Jingquan

    2016-01-01

    Objective The aim of our study was to evaluate the role of 18F-FDG PET/CT integrated imaging in differentiating malignant from benign pleural effusion. Methods A total of 176 patients with pleural effusion who underwent 18F-FDG PET/CT examination to differentiate malignancy from benignancy were retrospectively researched. The images of CT imaging, 18F-FDG PET imaging and 18F-FDG PET/CT integrated imaging were visually analyzed. The suspected malignant effusion was characterized by the presence of nodular or irregular pleural thickening on CT imaging. Whereas on PET imaging, pleural 18F-FDG uptake higher than mediastinal activity was interpreted as malignant effusion. Images of 18F-FDG PET/CT integrated imaging were interpreted by combining the morphologic feature of pleura on CT imaging with the degree and form of pleural 18F-FDG uptake on PET imaging. Results One hundred and eight patients had malignant effusion, including 86 with pleural metastasis and 22 with pleural mesothelioma, whereas 68 patients had benign effusion. The sensitivities of CT imaging, 18F-FDG PET imaging and 18F-FDG PET/CT integrated imaging in detecting malignant effusion were 75.0%, 91.7% and 93.5%, respectively, which were 69.8%, 91.9% and 93.0% in distinguishing metastatic effusion. The sensitivity of 18F-FDG PET/CT integrated imaging in detecting malignant effusion was higher than that of CT imaging (p = 0.000). For metastatic effusion, 18F-FDG PET imaging had higher sensitivity (p = 0.000) and better diagnostic consistency with 18F-FDG PET/CT integrated imaging compared with CT imaging (Kappa = 0.917 and Kappa = 0.295, respectively). The specificities of CT imaging, 18F-FDG PET imaging and 18F-FDG PET/CT integrated imaging were 94.1%, 63.2% and 92.6% in detecting benign effusion. The specificities of CT imaging and 18F-FDG PET/CT integrated imaging were higher than that of 18F-FDG PET imaging (p = 0.000 and p = 0.000, respectively), and CT imaging had better diagnostic consistency with

  1. Alterations in 18F-FDG accumulation into neck-related muscles after neck dissection for patients with oral cancers

    PubMed Central

    Kito, Shinji; Koga, Hirofumi; Kodama, Masaaki; Habu, Manabu; Kokuryo, Shinya; Oda, Masafumi; Matsuo, Kou; Nishino, Takanobu; Matsumoto-Takeda, Shinobu; Uehara, Masataka; Yoshiga, Daigo; Tanaka, Tatsurou; Nishimura, Shun; Miyamoto, Ikuya; Sasaguri, Masaaki; Tominaga, Kazuhiro; Yoshioka, Izumi; Morimoto, Yasuhiro

    2016-01-01

    Background 18F-fluoro-2-deoxy-D-glucose (18F-FDG) accumulations are commonly seen in the neck-related muscles of the surgical and non-surgical sides after surgery with neck dissection (ND) for oral cancers, which leads to radiologists having difficulty in diagnosing the lesions. To examine the alterations in 18F-FDG accumulation in neck-related muscles of patients after ND for oral cancer. Material and Methods 18F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) in neck-related muscles were retrospectively analyzed after surgical dissection of cervical lymph nodes in oral cancers. Results According to the extent of ND of cervical lymph nodes, the rate of patients with 18F-FDG-PET-positive areas increased in the trapezius, sternocleidomastoid, and posterior neck muscles of the surgical and/or non-surgical sides. In addition, SUVmax of 18F-FDG-PET-positive areas in the trapezius and sternocleidomastoid muscles were increased according to the extent of the ND. Conclusions In evaluating 18F-FDG accumulations after ND for oral cancers, we should pay attention to the 18F-FDG distributions in neck-related muscles including the non-surgical side as false-positive findings. Key words:18F-FDG, PET-CT, oral cancers, muscles. PMID:27031062

  2. Brain imaging in Alzheimer disease.

    PubMed

    Johnson, Keith A; Fox, Nick C; Sperling, Reisa A; Klunk, William E

    2012-04-01

    Imaging has played a variety of roles in the study of Alzheimer disease (AD) over the past four decades. Initially, computed tomography (CT) and then magnetic resonance imaging (MRI) were used diagnostically to rule out other causes of dementia. More recently, a variety of imaging modalities including structural and functional MRI and positron emission tomography (PET) studies of cerebral metabolism with fluoro-deoxy-d-glucose (FDG) and amyloid tracers such as Pittsburgh Compound-B (PiB) have shown characteristic changes in the brains of patients with AD, and in prodromal and even presymptomatic states that can help rule-in the AD pathophysiological process. No one imaging modality can serve all purposes as each have unique strengths and weaknesses. These modalities and their particular utilities are discussed in this article. The challenge for the future will be to combine imaging biomarkers to most efficiently facilitate diagnosis, disease staging, and, most importantly, development of effective disease-modifying therapies.

  3. Correlation of PET and AMS analyses for early kinetics of 2-fluoro-2-deoxyglucose (FDG)

    NASA Astrophysics Data System (ADS)

    Minamimoto, Ryogo; Hamabe, Yoshimi; Miyaoka, Teiji; Theeraladanon, Chumpol; Oka, Takashi; Matsui, Takao; Inoue, Tomio

    2010-04-01

    The draft of the guidelines for microdosing in clinical trials was published in Japan in 2008 following the guidelines of the European Medicines Agency (EMEA) and the Food and Drug Administration (FDA). It recommends utilizing accelerator mass spectrometry (AMS), liquid chromatography/mass spectrometry (LC/MS/MS), and positron emission tomography (PET) for monitoring drug metabolites in preclinical studies. In this study, we clarified the correlation in measuring result between PET and AMS. The AMS measurement was undergone by using AMS system of Institute of Accelerator Analysis Ltd. (IAA, Kawasaki, Japan). First the back ground 14C level of blood in mice was measured by AMS. Second, we clarified the relationship between AMS and PET by using 2-fluoro-2-deoxyglucose (FDG). The correlation coefficient ( r) of the measurements using PET ( 18F-FDG) and AMS ( 14C-FDG) were quite high at 0.97 ( Y = 7.54 E - 05 X + 0.02, p < 0.001). The blood clearance profile of 18F-FDG was nearly identical with that of 14C-FDG. These results indicate that the AMS analysis has excellent correlation with the PET method.

  4. Selection of patients for resection of hepatic metastases: improved detection of extrahepatic disease with FDG pet.

    PubMed

    Zealley, I A; Skehan, S J; Rawlinson, J; Coates, G; Nahmias, C; Somers, S

    2001-10-01

    A rapidly emerging clinical application of positron emission tomography (PET) is the detection of tumor tissue at whole-body studies performed with the glucose analogue 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG). High rates of recurrence after partial hepatic resection in patients with colorectal cancer liver metastases indicate that current presurgical imaging strategies are failing to show extrahepatic tumor deposits. Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in the liver and the lungs, it is particularly useful for identification and characterization of extrahepatic disease. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterization of indeterminate soft-tissue masses. Several sources of benign and physiologic increased activity at FDG PET emphasize the need for careful correlation with findings of other imaging studies and clinical findings. FDG PET can improve the selection of patients for partial hepatic resection and thereby reduce the morbidity and mortality associated with inappropriate surgery.

  5. FDG PET/CT dataset for navigation on femoral bone: a feasibility study.

    PubMed