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Sample records for f-18 fdg positron

  1. Hypoxia is important in F-18 FDG accumulation in thecoma-fibroma tumors on F-18 FDG PET/CT scans

    PubMed Central

    SEINO, HIROKO; ONO, SHUICHI; MIURA, HIROYUKI; MOROHASHI, SATOKO; WU, YUNYAN; TSUSHIMA, FUMIYASU; TAKAI, YOSHIHIRO; KIJIMA, HIROSHI

    2016-01-01

    Several studies have noted benign thecoma-fibroma tumors with positive F-18 fluorodeoxyglucose (FDG) accumulation mimicking malignant ovarian tumors following F-18 FDG positron emission tomography (PET). The present study analyzed four cases with false-positive F-18 FDG PET/computed tomography (CT) diagnoses of thecoma-fibroma tumors as malignant tumors due to F-18 FDG accumulation, compared with eight cases of FDG-positive ovarian cancers and two cases of FDG-negative fibromas. Hypoxia inducible factor (HIF)-1α expression was examined in the six thecoma-fibroma tumors using reverse transcription-polymerase chain reaction (RT-PCR). The four F-18 FDG-positive cases exhibited higher cellularity, maximum standard uptake and signal intensity on T2-weighted imaging, and gadolinium (Gd) enhancement using magnetic resonance imaging than the two FDG-negative fibroma cases. In the F-18 FDG-positive thecoma-fibroma group, Ki-67 expression was low and LAT1 expression was not identified, ruling out the diagnosis and potential for malignancy. However, considerable glucose transporter 1, HIF-1α, and vascular endothelial growth factor expression was observed. HIF-1α expression was elevated in all four false-positive cases by RT-PCR. From these results, it was hypothesized that hypoxia due to elevated cellularity may stimulate HIF-1α expression and be associated with F-18 FDG accumulation in F-18-positive thecoma-fibroma tumors. PMID:27035330

  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

    PubMed Central

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

    2015-01-01

    Abstract 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. PMID:25837761

  3. Parametric dynamic F-18-FDG PET/CT breast imaging

    NASA Astrophysics Data System (ADS)

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

    2008-03-01

    This study was undertaken to estimate metabolic tissue properties from dynamic breast F-18-FDG PET/CT image series and to display them as 3D parametric images. Each temporal PET series was obtained immediately after injection of 10 mCi of F-18-FDG and consisted of fifty 1- minute frames. Each consecutive frame was nonrigidly registered to the first frame using a finite element method (FEM) based model and fiducial skin markers. Nonlinear curve fitting of activity vs. time based on a realistic two-compartment model was performed for each voxel of the volume. Curve fitting was accomplished by application of the Levenburg-Marquardt algorithm (LMA) that minimized X2. We evaluated which parameters are most suitable to determine the spatial extent and malignancy in suspicious lesions. In addition, Patlak modeling was applied to the data. A mixture model was constructed and provided a classification system for the breast tissue. It produced unbiased estimation of the spatial extent of the lesions. We conclude that nonrigid registration followed by voxel-by-voxel based nonlinear fitting to a realistic two-compartment model yields better quality parametric images, as compared to unprocessed dynamic breast PET time series. By comparison with the mixture model, we established that the total cumulated activity and maximum activity parametric images provide the best delineation of suspicious breast tissue lesions and hyperactive subregions within the lesion that cannot be discerned in unprocessed images.

  4. Estimation of radiation dose received by the radiation worker during F-18 FDG injection process

    PubMed Central

    Jha, Ashish Kumar; Zade, Anand; Rangarajan, Venkatesh

    2011-01-01

    Background: The radiation dosimetric literature concerning the medical and non-medical personnel working in nuclear medicine departments are limited, particularly radiation doses received by radiation worker in nuclear medicine department during positron emission tomography (PET) radiopharmaceutical injection process. This is of interest and concern for the personnel. Aim: To measure the radiation dose received by the staff involved in injection process of Fluorine-18 Fluorodeoxyglucose (FDG). Materials and Methods: The effective whole body doses to the radiation workers involved in injections of 1511 patients over a period of 10 weeks were evaluated using pocket dosimeter. Each patient was injected with 5 MBq/kg of F-18 FDG. The F18-FDG injection protocol followed in our department is as follows. The technologist dispenses the dose to be injected and records the pre-injection activity. The nursing staff members then secure an intravenous catheter. The nuclear medicine physicians/residents inject the dose on a rotation basis in accordance with ALARA principle. After the injection of the tracer, the nursing staff members flush the intravenous catheter. The person who injected the tracer then measures the post-injection residual dose in the syringe. Results: The mean effective whole body doses per injection for the staff were the following: Nurses received 1.44±0.22 μSv/injection (3.71±0.48 nSv/MBq), for doctors the dose values were 2.44±0.25 μSv/injection (6.29±0.49 nSv/MBq) and for technologists the doses were 0.61±0.10 μSv/injection (1.58±0.21 nSv/MBq). It was seen that the mean effective whole body dose per injection of our positron emission tomography/computed tomography (PET/CT) staff who were involved in the F18-FDG injection process was maximum for doctors (54.34% differential doses), followed by nurses (32.02% differential doses) and technologist (13.64% differential doses). Conclusion: This study confirms that low levels of radiation dose are

  5. F18-FDG-PET for recurrent differentiated thyroid cancer: a systematic meta-analysis

    PubMed Central

    Haslerud, Torjan; Brauckhoff, Katrin; Reisæter, Lars; Küfner Lein, Regina; Heinecke, Achim; Varhaug, Jan Erik

    2015-01-01

    Background Positron emission tomography (PET) with fluor-18-deoxy-glucose (FDG) is widely used for diagnosing recurrent or metastatic disease in patients with differentiated thyroid cancer (DTC). Purpose To assess the diagnostic accuracy of FDG-PET for DTC in patients after ablative therapy. Material and Methods A systematic search was conducted in Medline/PubMed, EMBASE, Cochrane Library, Web of Science, and Open Grey looking for all English-language original articles on the performance of FDG-PET in series of at least 20 patients with DTC having undergone ablative therapy including total thyroidectomy. Diagnostic performance measures were pooled using Reitsma’s bivariate model. Results Thirty-four publications between 1996 and 2014 met the inclusion criteria. Pooled sensitivity and specificity were 79.4% (95% confidence interval [CI], 73.9–84.1) and 79.4% (95% CI, 71.2–85.4), respectively, with an area under the curve of 0.858. Conclusion F18-FDG-PET is a useful method for detecting recurrent DTC in patients having undergone ablative therapy. PMID:26163534

  6. Extensive tumor thrombus in a case of carcinoma lung detected by F18-FDG-PET/CT.

    PubMed

    Mudalsha, Ravina; Jacob, Mj; Pandit, Ag; Jora, Charu

    2011-04-01

    Tumor thrombus is a rare complication of solid cancers, mainly seen in cases of renal cell carcinoma, wilm's tumor, testicular carcinoma, adrenal cortical carcinoma and hepatocellular carcinoma.[1] Tumor thrombus in inferior vena cava is a rare complication of primary carcinoma lung. It should be identified so as to rule out venous thromboembolism and avoiding unnecessary anticoagulant therapy. We describe a case where F18-Fluorodeoxyglucose (FDG) positron emission tomography - computed tomography (PET/CT) helped to identify extensive tumor thrombus. PMID:22174524

  7. Extensive tumor thrombus in a case of carcinoma lung detected by F18-FDG-PET/CT

    PubMed Central

    Mudalsha, Ravina; Jacob, MJ; Pandit, AG; Jora, Charu

    2011-01-01

    Tumor thrombus is a rare complication of solid cancers, mainly seen in cases of renal cell carcinoma, wilm's tumor, testicular carcinoma, adrenal cortical carcinoma and hepatocellular carcinoma.[1] Tumor thrombus in inferior vena cava is a rare complication of primary carcinoma lung. It should be identified so as to rule out venous thromboembolism and avoiding unnecessary anticoagulant therapy. We describe a case where F18-Fluorodeoxyglucose (FDG) positron emission tomography - computed tomography (PET/CT) helped to identify extensive tumor thrombus. PMID:22174524

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

    PubMed Central

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

    2015-01-01

    Abstract 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. PMID:26632889

  9. 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.

  10. Fluorination in aqueous media with elemental fluorine: The synthesis of (F-18)2-FDG

    SciTech Connect

    Bida, G.T.; Satyamurthy, N.; Barrio, J.R.

    1984-01-01

    Continued emphasis on the use of F-18 labeled 2-deoxy-2-fluor-D-glucose (2-FDG) for the determination of local organ glucose metabolism in normal and diseased states with PET provides the impetus for investigation of more facile procedures for synthesizing this important radiopharmaceutical. The authors report herein the regio- and stereo-selective addition of fluorine across a double bond, i.e. D-glucal (1), in aqueous media to yield 2-FDG. 2-FDG was prepared by bubbling 0.2% fluorine in neon into an aqueous solution containing an equimolar amount of glucal at room temperature. Hydrolysis of the resultant fluorinated product mixture with 1 N HCL (120/sup 0/C, 15m) followed by chromatographic purification, using an ion retardation resin-alumina column gave 2-FDG in about 60% yield. The final product was identified by TLC, /sup 19/F NMR (94.1 MHz, deuterium oxide, hexafluorobezene (external standard) delta + 32.81 ppm (..cap alpha..-anomer, 48.5%) and + 32.51 ppm (..beta..-anomer, 51.5%)), and by its conversion to the corresponding 6-phosphate with yeast hexokinase as shown by HPLC. This method was extended to the synthesis of (F-18)2-FDG. (F-18)2-FDG was similarly prepared as described above from (F-18)fluorine in radiochemical yields of 25-30% (50-60% of theoretical maximum) with a processing time of 30 min after EOB. This synthesis of (F-18)2-FDG provides simplification, reduced processing time, and a radiochemical yield that is competitive with other methods recently described.

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

    PubMed Central

    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. PMID:24019675

  12. [F-18] FDG-PET/CT parameters as predictors of outcome in inoperable NSCLC patients

    PubMed Central

    Nappi, Antonio; Gallicchio, Rosj; Simeon, Vittorio; Nardelli, Anna; Pelagalli, Alessandra; Zupa, Angela; Vita, Giulia; Venetucci, Angela; Di Cosola, Michele; Barbato, Francesco; Storto, Giovanni

    2015-01-01

    Background We evaluated the prognostic significance of standardized uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) in [F-18] FDG PET/CT findings in patients with inoperable non-small-cell lung cancer (NSCLC). Patients and methods. One hundred and three patients (mean age, 65.6 ± 16 years) underwent [F-18] FDG PET/CT before the chemotherapy. The SUVmax value, the MTV (cm3; 42% threshold) and the TLG (g) were registered. The patients were followed up to 18 months thereafter (range 12–55 months). Failure to respond without progression, progression and/or disease-related death constituted surrogate end-points. The optimal SUVmax, MTV and TLG cut-off to predict the patients’ outcome were estimated. PET/CT results were then related to disease outcome (progression free survival; PFS). Results The Kaplan-Meier survival analysis for SUVmax showed a significant shorter PFS in patients presenting with lower values as compared to those with higher (p < 0.05, log-rank test). MTV and TLG were not suitable for predicting PFS apart from the subset of patients with mediastinal nodal involvement. Conclusions Despite the availability of new tools for the quantitative assessment of disease activity on PET/CT, the SUVmax rather than MTV and TLG remains the only predictor for PFS in NSCLC patients. MTV holds a value only when concomitant nodal involvement occurs. PMID:26834517

  13. 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.

  14. 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. PMID:27523454

  15. Hodgkin lymphoma post-transplant lymphoproliferative disorder following pediatric renal transplant: serial imaging with F-18 FDG PET/CT.

    PubMed

    Makis, William; Lisbona, Robert; Derbekyan, Vilma

    2010-09-01

    Post-transplant lymphoproliferative disorder (PTLD) occurs in 1.2% of pediatric renal transplant patients, and is frequently Epstein-Barr Virus mediated. Hodgkin Lymphoma PTLD is the rarest of the 4 types of PTLDs recognized by the World Health Organization, with an incidence of <4% of all PTLD patients. It has a distinct clinical course and treatment from all other types of PTLD. This is a case of a 16-year-old girl who had a renal transplant in 2000 due to Moya Moya disease. Her first F-18 FDG PET/CT done in 2006 showed mildly FDG-avid mediastinal adenopathy (histologically nonspecific reactive nodes), however in 2009, after presenting with fevers, a repeat PET/CT showed extensive intensely FDG-avid disease. Biopsy of a supraclavicular node identified Hodgkin Lymphoma PTLD. The patient was treated with chemotherapy and reimaged, showing excellent response to therapy. In contrast, classic PTLD is treated by withdrawal of immunosuppression and administration of Rituximab. F-18 FDG PET/CT is known to be very useful in the staging and monitoring of response to therapy in the setting of classic PTLD. In this case, serial F-18 FDG PET/CT scans proved very useful in the evaluation and follow-up of the rare and distinct Hodgkin Lymphoma PTLD subtype. PMID:20706047

  16. 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.

  17. 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.

  18. Bone scintigraphy using Tc-99m DPD and F18-FDG in a patient with SAPHO syndrome.

    PubMed

    Pichler, Robert; Weiglein, Klaus; Schmekal, Barnhard; Sfetsos, Konstantinos; Maschek, Wilhelmine

    2003-01-01

    Synovitis (inflammatory arthritis), acne (pustulosa), palmoplantar pustulosis, hyperostosis and osteitis (bland osteomyelitis) are symptoms forming the acronym SAPHO. We present the case of a 48-year old man with sterno-costo-clavicular hyperostosis and typical pustulosis palmaris. We performed Tc-99m DPD serial bone scanning to monitor the course of disease and to assess therapeutic efficiency. Control bone scans in 2001 showed minor compromises of the ribs and diminished disease activity on collarbones and the sternum after medication with non-steroidal anti-inflammatory drugs (NSAIDs) and bisphosphonates. F-18 FDG PET presented synovial inflammation in the left sterno-clavicular joint but no relevant tracer uptake on clavicles or breastbones. In case of diagnostic doubts F-18 FDG PET could be recommended in order to discriminate bland osteomyelitis from bacterial osteomyelitis or from bone malignancy when SAPHO-syndrome is assumed. PMID:12635949

  19. Choice of reference area in studies of Alzheimer's disease using positron emission tomography with fluorodeoxyglucose-F18.

    PubMed

    Yakushev, Igor; Landvogt, Christian; Buchholz, Hans-Georg; Fellgiebel, Andreas; Hammers, Alexander; Scheurich, Armin; Schmidtmann, Irene; Gerhard, Alexander; Schreckenberger, Mathias; Bartenstein, Peter

    2008-11-30

    At present, there is still no consensus on the choice of the reference area in positron emission tomography (PET) studies of Alzheimer's disease (AD). In this study, PET scans with fluorodeoxyglucose-F18 were carried out in the following groups of subjects: 47 patients with probable AD, 8 patients with mild cognitive impairment, and 15 age-similar healthy subjects. Scans normalized to the cerebral global mean (CGM), cerebellum (CBL), and the primary sensorimotor cortex (SMC). We evaluated the effect of the different count normalization procedures on the accuracy of (18)F-FDG PET to detect AD-specific metabolic abnormalities (voxel-based group comparison) and to differentiate between patients and healthy subjects (ROI-based discriminant analysis) with regard to the degree of clinical deterioration. Metabolic reductions in groups of very mildly, mildly and moderate-to-severely affected patients appeared, respectively, 2.2, 2.6, and 2.7 times greater in spatial extent when tracer uptake was normalized to SMC rather than to CGM. The overall accuracy of discrimination was 94%, 91%, and 80% after normalization to SMC, CBL, and CGM, respectively. In general, normalization to SMC was somewhat superior to cerebellar normalization, allowing the detection of more pronounced metabolic deficits and the more accurate discrimination of patients from non-patients. Normalization to CGM should be used with great caution not only in advanced stages of dementia, but also in very mild AD cases. PMID:18930634

  20. Nerve Sheath Tumors in Neurofibromatosis Type 1: Assessment of Whole-Body Metabolic Tumor Burden Using F-18-FDG PET/CT

    PubMed Central

    Salamon, Johannes; Papp, László; Tóth, Zoltán; Laqmani, Azien; Apostolova, Ivayla; Adam, Gerhard; Mautner, Victor F.; Derlin, Thorsten

    2015-01-01

    Purpose To determine the metabolically active whole-body tumor volume (WB-MTV) on F-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) in individuals with neurofibromatosis type 1 (NF1) using a three-dimensional (3D) segmentation and computerized volumetry technique, and to compare PET WB-MTV between patients with benign and malignant peripheral nerve sheath tumors (PNSTs). Patients and Methods Thirty-six NF1 patients (18 patients with malignant PNSTs and 18 age- and sex-matched controls with benign PNSTs) were examined by F-18-FDG PET/CT. WB-MTV, whole-body total lesion glycolysis (WB-TLG) and a set of semi-quantitative imaging-based parameters were analyzed both on a per-patient and a per-lesion basis. Results On a per-lesion basis, malignant PNSTs demonstrated both a significantly higher MTV and TLG than benign PNSTs (p < 0.0001). On a per-patient basis, WB-MTV and WB-TLG were significantly higher in patients with malignant PNSTs compared to patients with benign PNSTs (p < 0.001). ROC analysis showed that MTV and TLG could be used to differentiate between benign and malignant tumors. Conclusions WB-MTV and WB-TLG may identify malignant change and may have the potential to provide a basis for investigating molecular biomarkers that correlate with metabolically active disease manifestations. Further evaluation will determine the potential clinical impact of these PET-based parameters in NF1. PMID:26625155

  1. Factors affecting myocardial 2-[F-18]fluoro-2-deoxy-D-glucose uptake in positron emission tomography studies of normal humans.

    PubMed

    Choi, Y; Brunken, R C; Hawkins, R A; Huang, S C; Buxton, D B; Hoh, C K; Phelps, M E; Schelbert, H R

    1993-04-01

    The goal of this study was to identify the anatomic and physiologic factors affecting left ventricular myocardial 2-[F-18]fluoro-2-deoxy-D-glucose (FDG) uptake and myocardial glucose utilization rates (MRGlc) in normal humans. Eighteen healthy male volunteers were studied in the fasting state (4-19 h) and 16 after oral glucose loading (100 g dextrose) with positron emission tomography (PET) and FDG. Substrate and hormone concentrations were measured in each study. The kinetics of myocardial FDG uptake were evaluated using both a three-compartment model and Patlak graphical analysis. Systolic blood pressures and rate pressure products were similar in the fasting and postglucose states. MRGlc averaged 0.24 +/- 0.17 mumol/min/g in fasting subjects and rose to 0.69 +/- 0.11 mumol/min/g after glucose loading. Phosphorylation rate constant, k3, and MRGlc were linearly related (P < 0.001). Increases in MRGlc following glucose loading were correlated with plasma glucose, insulin and free fatty acid concentrations, ratios of insulin to glucagon levels, and influx rate constants of FDG. Glucose loading improved the diagnostic image quality due to more rapid clearance of tracer from blood and higher myocardial FDG uptake. When MRGlc, glucose and insulin concentrations, and insulin to glucagon ratios exceeded 0.2 mumol/min/g, 100 mg/dl, 19 microU/ml, and 0.2 microU/pg, respectively, myocardial uptake of FDG was always adequate for diagnostic use. FDG image quality and MRGlc were similar after relatively short (6 +/- 2 h) and overnight (16 +/- 2 h) fasting. Significant (P < 0.05) regional heterogeneity of myocardial FDG uptake and MRGlc was observed in both the fasting and the postglucose studies. MRGlc and FDG uptake values in the posterolateral wall were higher than those in the anterior wall and septum. Thus, both 6-h and overnight fasts resulted in similarly low myocardial glucose utilization rates. While MRGlc and myocardial FDG uptake depended on plasma glucose, free

  2. [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.

  3. [F-18]-Fluoro-2-deoxy-D-glucose positron emission tomography as a tool for early detection of immunotherapy response in a murine B cell lymphoma model

    PubMed Central

    Chaise, Coralie; Itti, Emmanuel; Petegnief, Yolande; Wirquin, Evelyne; Copie-Bergman, Christiane; Farcet, Jean-Pierre; Delfau-Larue, Marie-Hélène; Meignan, Michel; Talbot, Jean-Noël; Molinier-Frenkel, Valérie

    2007-01-01

    [F-18]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is a non-invasive imaging technique which has recently been validated for the assessment of therapy response in patients with aggressive non-Hodgkin’s lymphoma. Our objective was to determine its value for the evaluation of immunotherapy efficacy in immunocompetent Balb/c mice injected with the A20 syngeneic B lymphoma cell line. The high level of in vitro FDG uptake by A20 cells validated the model for further imaging studies. When injected intravenously, the tumour developed as nodular lesions mostly in liver and spleen, thus mimicking the natural course of an aggressive human lymphoma. FDG-PET provided three-dimensionnal images of tumour extension including non palpable lesions, in good correlation with ex-vivo macroscopic examination. When mice were pre-immunized with an A20 cell lysate in adjuvant before tumour challenge, their significantly longer survival, compared to control mice, was associated with a lower incidence of lymphoma visualized by PET at different time points. Estimation of tumour growth and metabolism using the calculated tumour volumes and maximum standardized uptake values respectively, also demonstrated delayed lymphoma development and lower activity in the vaccinated mice. Thus, FDG-PET is a sensitive tool relevant for early detection and follow-up of internal tumours, allowing discrimination between treated and non-treated small animal cohorts without invasive intervention. PMID:17171356

  4. 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

  5. Tenosynovial Giant Cell Tumor of Diffuse Type Mimicking Bony Metastasis Detected on F-18 FDG PET/CT.

    PubMed

    Chang, Kyoung Jin; Byun, Byung Hyun; Moon, Han Sol; Park, Jihyun; Koh, Jae Soo; Kim, Byung Il; Lim, Sang Moo

    2014-09-01

    Tenosynovial giant cell tumor of diffuse type (TGCT-D) is a locally aggressive neoplasm that arises in the tendon sheath, bursa, or synovium. It typically involves the appendicular skeleton and rarely involves the axial skeleton. Because there are no specific findings of TGCT-D based on imaging studies or clinical symptoms, TGCT-D can be confused with other primary or metastatic bone tumors. We report findings of TGCT-D involving the T9 vertebra incidentally detected on F-18 FDG PET/CT in a patient with papillary thyroid cancer. PMID:25177381

  6. 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.

  7. F-18 deoxyglucose and stress N-13 ammonia positron emission tomography in anterior wall healed myocardial infarction

    SciTech Connect

    Fudo, T.; Kambara, H.; Hashimoto, T.; Hayashi, M.; Nohara, R.; Tamaki, N.; Yonekura, Y.; Senda, M.; Konishi, J.; Kawai, C.

    1988-06-01

    To evaluate myocardial blood flow and glucose utilization, N-13 ammonia (NH3) and F-18 deoxyglucose positron emission tomography scanning was performed in 22 patients with previous anterior wall myocardial infarction, using a high-resolution, multi-slice, whole-body scanner. The N-13 ammonia study was performed at rest and after exercise. The F-18 deoxyglucose study was performed at rest after fasting greater than 5 hours. The N-13 ammonia study revealed a hypoperfused area in 19 of the 22 patients (86%), that corresponded to the infarcted regions as diagnosed by electrocardiography, coronary arteriography and left ventriculography (21 patients). The hypoperfused areas expanded after exercise in 16 of 22 patients (73%). F-18 deoxyglucose uptake was observed in these hypoperfused areas, especially in patients with hypokinetic wall motion on left ventriculography and in exercise-induced hypoperfused areas. However, positron emission tomography demonstrated diffuse uptake of F-18 deoxyglucose in 3 of 8 patients with dyskinetic wall motion. Thus, metabolically active myocardium in infarcted areas or periinfarct ischemia can be visualized with F-18 deoxyglucose and stress N-13 ammonia studies.

  8. Comparative study of 18F-DOPA, 13N-Ammonia and F18-FDG PET/CT in primary brain tumors

    PubMed Central

    Jacob, Mattakarottu J; Pandit, Aniruddha G; Jora, Charu; Mudalsha, Ravina; Sharma, Amit; Pathak, Harish C

    2011-01-01

    Aim: To determine the diagnostic reliability of 18F-FDOPA, 13N-Ammonia and F18-FDG PET/CT in primary brain tumors. We evaluated the amino acid and glucose metabolism of brain tumors by using PET with 18F-FDOPA, 13N-Ammonia and F18-FDG PET/CT. Materials and Methods: Nine patients undergoing evaluation for brain tumors were studied. Tracer uptake was quantified by the use of standardized uptake values and the ratio of tumor uptake to normal identical area of contra lateral hemisphere (T/N). In addition, PET uptake with 18F-FDOPA was quantified by use of ratio of tumor uptake to striatum uptake (T/S). The results were correlated with the patient's clinical profile. Results: Both high-grade and low-grade tumors were well visualized with 18F-FDOPA. The sensitivity for identifying tumors was substantially higher with 18F-FDOPA PET than with F18-FDG and 13N-Ammonia PET as determined by simple visual inspection. The sensitivity for identifying recurrence in low grade gliomas is higher with 13N-Ammonia than with F18-FDG. Conclusion: 18F-FDOPA PET is more reliable than F18-FDG and 13N-Ammonia PET for evaluating brain tumors. PMID:23326065

  9. F-18 fluoro-d-glucose positron emission tomography/computed tomography in a patient with corticobasal degeneration.

    PubMed

    Marti, Alejandro

    2015-01-01

    Corticobasal degeneration is a rare neurodegenerative disorder that often eludes clinical diagnosis. The present case shows the F-18 fluoro-d-glucose positron emission tomography/computed tomography (PET/CT) of a 62-year-old man with a progressive movement disorder with asymmetric features. PET/CT examination showed a markedly right-brain hemispheric hypometabolism also involving basal ganglia. PMID:25829747

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

    PubMed

    Kwon, Hyun Woo; Kim, Jong Phil; Lee, Hong Jae; Paeng, Jin Chul; Lee, Jae Sung; Cheon, Gi Jeong; Lee, Dong Soo; Chung, June-Key; Kang, Keon Wook

    2016-02-01

    The purpose of this study was to estimate average radiation exposure from (18)F-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

  11. 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

  12. Attenuation-Corrected vs. Nonattenuation-Corrected 2-Deoxy-2-[F-18]fluoro-d-glucose-Positron Emission Tomography in Oncology, A Systematic Review

    PubMed Central

    Joshi, Urvi; Riphagen, Ingrid I.; Teule, Gerrit J. J.; van Lingen, Arthur; Hoekstra, Otto S.

    2007-01-01

    Purpose To perform a systematic review and meta-analysis to determine the diagnostic accuracy of attenuation-corrected (AC) vs. nonattenuation-corrected (NAC) 2-deoxy-2-[F-18]fluoro-d-glucose-positron emission tomography (FDG-PET) in oncological patients. Procedures Following a comprehensive search of the literature, two reviewers independently assessed the methodological quality of eligible studies. The diagnostic value of AC was studied through its sensitivity/specificity compared to histology, and by comparing the relative lesion detection rate reported with NAC-PET vs. AC, for full-ring and dual-head coincidence PET (FR- and DH-PET, respectively). Results Twelve studies were included. For FR-PET, the pooled sensitivity/specificity on a patient basis was 64/97% for AC and 62/99% for NAC, respectively. Pooled lesion detection with NAC vs. AC was 98% [95% confidence interval (95% CI): 96–99%, n = 1,012 lesions] for FR-PET, and 88% (95% CI:81–94%, n = 288 lesions) for DH-PET. Conclusions Findings suggest similar sensitivity/specificity and lesion detection for NAC vs. AC FR-PET and significantly higher lesion detection for NAC vs. AC DH-PET. PMID:17318671

  13. Malignant extrarenal rhabdoid tumor of the spine: staging and evaluation of response to therapy with F-18 FDG PET/CT.

    PubMed

    Makis, William; Ciarallo, Anthony; Hickeson, Marc

    2011-07-01

    Malignant extrarenal rhabdoid tumor (ERRT) is a very rare type of soft-tissue sarcoma with a reported incidence of 0.3% of all soft-tissue sarcomas. Only 7 cases of spinal malignant ERRT have been reported in the literature, and to our knowledge, F-18 FDG PET/CT imaging for staging and evaluation of response to therapy for these tumors has not been previously described. This is a case of an 8-month-old boy with malignant ERRT of the spine, who was staged with F-18 FDG PET/CT, and had his tumor burden assessed with PET/CT after chemotherapy, which altered the subsequent chemotherapy regimen. PMID:21637073

  14. Cerebral metabolic rates for glucose in mood disorders. Studies with positron emission tomography and fluorodeoxyglucose F 18

    SciTech Connect

    Baxter, L.R. Jr.; Phelps, M.E.; Mazziotta, J.C.; Schwartz, J.M.; Gerner, R.H.; Selin, C.E.; Sumida, R.M.

    1985-05-01

    Cerebral metabolic rates for glucose were examined in patients with unipolar depression (N = 11), bipolar depression (N = 5), mania (N = 5), bipolar mixed states (N = 3), and in normal controls (N = 9) using positron emission tomography and fluorodeoxyglucose F 18. All subjects were studied supine under ambient room conditions with eyes open. Bipolar depressed and mixed patients had supratentorial whole brain glucose metabolic rates that were significantly lower than those of the other comparison groups. The whole brain metabolic rates for patients with bipolar depression increased going from depression or a mixed state to a euthymic or manic state. Patients with unipolar depression showed a significantly lower ratio of the metabolic rate of the caudate nucleus, divided by that of the hemisphere as a whole, when compared with normal controls and patients with bipolar depression.

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

    PubMed Central

    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. PMID:27095869

  16. Unusual case of infantile fibrosarcoma evaluated on F-18 fluorodeoxyglucose positron emission tomography-computed tomography.

    PubMed

    Bedmutha, Akshay; Singh, Natasha; Shivdasani, Divya; Gupta, Nitin

    2016-01-01

    Infantile fibrosarcoma (IFS) is a rare soft-tissue sarcoma originating from extremities and occasionally from axial soft tissue. The prognosis is good with favorable long-term survival. It is rarely metastasizing tumor, the chances being lesser with IFS originating from extremities. Use of neoadjuvant chemotherapy (NACT) as a treatment regime further reduces the chances of local relapse and distant metastasis. The organs commonly affected in metastatic IFS are lungs and lymph nodes. We report an unusual case of an IFS originating from extremity, which received NACT, yet presented with an early metastatic disease involving soft tissues and sparing lungs and lymph nodes, as demonstrated on fluorodeoxyglucose positron emission tomography-computed tomography. PMID:27385891

  17. Unusual case of infantile fibrosarcoma evaluated on F-18 fluorodeoxyglucose positron emission tomography-computed tomography

    PubMed Central

    Bedmutha, Akshay; Singh, Natasha; Shivdasani, Divya; Gupta, Nitin

    2016-01-01

    Infantile fibrosarcoma (IFS) is a rare soft-tissue sarcoma originating from extremities and occasionally from axial soft tissue. The prognosis is good with favorable long-term survival. It is rarely metastasizing tumor, the chances being lesser with IFS originating from extremities. Use of neoadjuvant chemotherapy (NACT) as a treatment regime further reduces the chances of local relapse and distant metastasis. The organs commonly affected in metastatic IFS are lungs and lymph nodes. We report an unusual case of an IFS originating from extremity, which received NACT, yet presented with an early metastatic disease involving soft tissues and sparing lungs and lymph nodes, as demonstrated on fluorodeoxyglucose positron emission tomography-computed tomography. PMID:27385891

  18. 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.

  19. 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 Central

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

    2015-01-01

    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. PMID:25800594

  20. Is [F-18]-fluorodeoxyglucose FDG-PET/CT better than ct alone for the preoperative lymph node staging of muscle invasive bladder cancer?

    PubMed Central

    Uttam, Mete; Pravin, Nayak; Anish, Bhattacharya; Nandita, Kakkar; Arup, Mandal

    2016-01-01

    ABSTRACT Objective: To evaluate whether the use of [F-18]-FDG-PET/CT can accurately predict pelvic lymph node metastasis in patients with muscle invasive TCC of the bladder undergoing radical cystectomy. Materials and Methods: Fifteen patients with muscle invasive bladder cancer had undergone FDG-PET/CT scan from the skull base to the mid-thighs after IV injection of 6.5MBq (Mega-Becquerel)/Kg of FDG. After intravenous hydration IV furosemide was given to overcome the difficulties posed by urinary excretion of 18F-FDG. PET/CT data were analyzed as PET and CT images studied separately as well as fused PET/CT images. The imaging findings were correlated with the histopathology of the nodes (gold standard). Results: CT and FDG-PET had demonstrated positive lymph nodes in 9 & 8 patients respectively. Among the 15 patients 3 had documented metastasis on histopathology. Both CT and PET could detect the nodes in all these 3 patients (100% sensitivity). Nodes were histologically negative amongst 6&5 patients who had node involvement by CT and PET respectively. Therefore, specificity, positive predictive value (PPV) & negative predictive value (NPV) for CT and PET/CT were 50%, 33.3%, 100% and 58.3%, 37.5%, 100% respectively. Conclusion: The theoretical advantage of this cutting edge technology for whole body imaging has not been translated into clinical practice as we found minimal advantage of combined FDG-PET/CT over CT alone for nodal staging of muscle invasive bladder cancer. This may be due to substantial overlap between standardized uptake values (SUVs) from active inflammatory processes with those of malignant lesion. PMID:27256176

  1. 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.

  2. F-18-FDG-PET Confined Radiotherapy of Locally Advanced NSCLC With Concomitant Chemotherapy: Results of the PET-PLAN Pilot Trial

    SciTech Connect

    Fleckenstein, Jochen; Hellwig, Dirk; Kremp, Stephanie; Grgic, Aleksandar; Groeschel, Andreas; Kirsch, Carl-Martin; Nestle, Ursula; Ruebe, Christian

    2011-11-15

    Purpose: The integration of fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) in the process of radiotherapy (RT) planning of locally advanced non-small-cell lung cancer (NSCLC) may improve diagnostic accuracy and minimize interobserver variability compared with target volume definition solely based on computed tomography. Furthermore, irradiating only FDG-PET-positive findings and omitting elective nodal regions may allow dose escalation by treating smaller volumes. The aim of this prospective pilot trial was to evaluate the therapeutic safety of FDG-PET-based RT treatment planning with an autocontour-derived delineation of the primary tumor. Methods and Materials: Eligible patients had Stages II-III inoperable NSCLC, and simultaneous, platinum-based radiochemotherapy was indicated. FDG-PET and computed tomography acquisitions in RT treatment planning position were coregistered. The clinical target volume (CTV) included the FDG-PET-defined primary tumor, which was autodelineated with a source-to-background algorithm, plus FDG-PET-positive lymph node stations. Limited by dose restrictions for normal tissues, prescribed total doses were in the range of 66.6 to 73.8 Gy. The primary endpoint was the rate of out-of-field isolated nodal recurrences (INR). Results: As per intent to treat, 32 patients received radiochemotherapy. In 15 of these patients, dose escalation above 66.6 Gy was achieved. No Grade 4 toxicities occurred. After a median follow-up time of 27.2 months, the estimated median survival time was 19.3 months. During the observation period, one INR was observed in 23 evaluable patients. Conclusions: FDG-PET-confined target volume definition in radiochemotherapy of NSCLC, based on a contrast-oriented source-to-background algorithm, was associated with a low risk of INR. It might provide improved tumor control because of dose escalation.

  3. F18-FDG-PET/CT thyroid incidentalomas: a wide retrospective analysis in three Italian centres on the significance of focal uptake and SUV value.

    PubMed

    Bertagna, Francesco; Treglia, Giorgio; Piccardo, Arnoldo; Giovannini, Elisabetta; Bosio, Giovanni; Biasiotto, Giorgio; Bahij, El Khayat; Maroldi, Roberto; Giubbini, Raffaele

    2013-06-01

    Thyroid incidental uptake is defined as a thyroid uptake incidentally and newly detected by imaging techniques performed for an unrelated purpose and especially for non-thyroid diseases. Aim of the study was to establish the prevalence and pathological nature of focal thyroid incidentalomas detected at F18-FDG-PET/CT in patients studied for oncological purposes and not for thyroid disease. Secondary end point was to establish a possible maximum standardised uptake value cut-off over which a malignant lesion should be suspected. We have retrospectively evaluated 49519 patients who underwent F18-FDG-PET/CT for oncologic purposes in three Nuclear Medicine Centres (N.1 = 11278, N.2 = 31076, N.3 = 7165). A focal incidental thyroid uptake was diagnosed in 729 (1.5 %) patients (287-39.4 % male and 442-60.6 % female; average age: 65.26). Of 729 thyroid incidentalomas 211 (28.9 %) underwent further investigation to determine the nature of the nodule; 124/211 (58.8 %) incidentalomas were benign, 72/211 (34.1 %) malignant, 4/211 (1.9 %) non-diagnostic at cytological examination in the absence of surgery and histological evaluation and 11/211 (5.2 %) were indeterminate at cytological examination. A centre-based receiver operating curve (ROC) analysis of the patients with a definitive diagnosis was performed to identify a SUVmax cut-off useful in differentiating benign from malignant incidentalomas. In the centre N.1 it was 4.8 (sensitivity = 95.7 %, specificity = 46.4 %, area under the curve = 0.758); 5.3 in the centre N.2 (sensitivity = 76.3 %, specificity = 72.5 %, area under the curve = 0.815); 7 in the centre N.3 (sensitivity = 57.1 %, specificity = 79.3 %, area under the curve = 0.627). F18-FDG-PET/CT thyroid incidentalomas are a relevant diagnostic reality which requires further investigations and clinical management especially considering that, despite mainly benign, approximately one third of focal thyroid uptakes are malignant. PMID:23179777

  4. 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.

  5. Challenges and Approaches to Quantitative Therapy Response Assessment in Glioblastoma Multiforme Using the Novel Apoptosis Positron Emission Tomography Tracer F-18 ML-101

    PubMed Central

    Oborski, Matthew J; Laymon, Charles M; Qian, Yongxian; Lieberman, Frank S; Nelson, Arden D; Mountz, James M

    2014-01-01

    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. PMID:24772214

  6. Zolpidem-Induced Arousal by Paradoxical GABAergic Stimulation: A Case Report With F-18 Flumazenil Positron Emission Tomography and Single Photon Emission Computed Tomography Study

    PubMed Central

    Kim, Changjae; Nam, Ki Yeun; Park, Jin Woo; Lee, Ho Jun

    2016-01-01

    Zolpidem is a non-benzodiazepine drug that has selectivity for the gamma-aminobutyric acid (GABA) receptors. We experienced paradoxical effect of zolpidem in a 48-year-old male patient with hypoxic-ischemic brain injury after cardiac arrest. The patient was in stupor and could not communicate. His Glasgow Coma Scale (GCS) was E2M4V2 and Rancho Los Amigos (RLA) was grade III to IV. Zolpidem was prescribed to induce sedation but paradoxically, he became alert (GCS 15, RLA VII) and was able to communicate. The arousal lasted for 2 hours repeatedly following each administration of the medication. While he was alert, electroencephalogram showed the reversal of slow wave into beta range fast activity and F-18 flumazenil positron emission tomography (PET) showed increased GABAergic receptor activity in both frontoparietotemporal cortices. Single photon emission computed tomography (SPECT) also showed increased cerebral perfusion and reversal of cerebellar diaschisis. PMID:26949686

  7. Zolpidem-Induced Arousal by Paradoxical GABAergic Stimulation: A Case Report With F-18 Flumazenil Positron Emission Tomography and Single Photon Emission Computed Tomography Study.

    PubMed

    Kim, Changjae; Kwon, Bum Sun; Nam, Ki Yeun; Park, Jin Woo; Lee, Ho Jun

    2016-02-01

    Zolpidem is a non-benzodiazepine drug that has selectivity for the gamma-aminobutyric acid (GABA) receptors. We experienced paradoxical effect of zolpidem in a 48-year-old male patient with hypoxic-ischemic brain injury after cardiac arrest. The patient was in stupor and could not communicate. His Glasgow Coma Scale (GCS) was E2M4V2 and Rancho Los Amigos (RLA) was grade III to IV. Zolpidem was prescribed to induce sedation but paradoxically, he became alert (GCS 15, RLA VII) and was able to communicate. The arousal lasted for 2 hours repeatedly following each administration of the medication. While he was alert, electroencephalogram showed the reversal of slow wave into beta range fast activity and F-18 flumazenil positron emission tomography (PET) showed increased GABAergic receptor activity in both frontoparietotemporal cortices. Single photon emission computed tomography (SPECT) also showed increased cerebral perfusion and reversal of cerebellar diaschisis. PMID:26949686

  8. 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.

  9. 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

    Sirianni, Rachael W; Zheng, Ming-Qiang; Patel, Toral R; Shafbauer, Thomas; Zhou, Jiangbing; Saltzman, W Mark; Carson, Richard E; Huang, Yiyun

    2014-12-17

    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, [(18)F]4-fluorobenzylamine, and a commercially available biotin derivate, NHS-PEG4-biotin, [(18)F]-fluorobenzylamide-poly(ethylene glycol)4-biotin ([(18)F]NPB4) was prepared with high purity and specific activity. The attachment of the [(18)F]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

  10. 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

  11. The usefulness of F-18 FDG PET/CT-mammography for preoperative staging of breast cancer: comparison with conventional PET/CT and MR-mammography

    PubMed Central

    Moon, Eun-Ha; Lim, Seok Tae; Han, Yeon-Hee; Jeong, Young Jin; Kang, Yun-Hee; Jeong, Hwan-Jeong; Sohn, Myung-Hee

    2013-01-01

    Background The objective of the study was to compare the diagnostic efficacy of an integrated Fluorine-18 fluorodeoxyglucose (F-18 FDG) PET/CT-mammography (mammo-PET/CT) with conventional torso PET/CT (supine-PET/CT) and MR-mammography for initial assessment of breast cancer patients. Patients and methods Forty women (52.0 ± 12.0 years) with breast cancer who underwent supine-PET/CT, mammo-PET/CT, and MR-mammography from April 2009 to August 2009 were enrolled in the study. We compared the size of the tumour, tumour to chest wall distance, tumour to skin distance, volume of axillary fossa, and number of meta-static axillary lymph nodes between supine-PET/CT and mammo-PET/CT. Next, we assessed the difference of focality of primary breast tumour and tumour size in mammo-PET/CT and MR-mammography. Histopathologic findings served as the standard of reference. Results In the comparison between supine-PET/CT and mammo-PET/CT, significant differences were found in the tumour size (supine-PET/CT: 1.3 ± 0.6 cm, mammo-PET/CT: 1.5 ± 0.6 cm, p < 0.001), tumour to thoracic wall distance (1.8 ± 0.9 cm, 2.2 ± 2.1 cm, p < 0.001), and tumour to skin distance (1.5 ± 0.8 cm, 2.1 ± 1.4 cm, p < 0.001). The volume of axillary fossa was significantly wider in mammo-PET/CT than supine-PET/CT (21.7 ± 8.7 cm3 vs. 23.4 ± 10.4 cm3, p = 0.03). Mammo-PET/CT provided more correct definition of the T-stage of the primary tumour than did supine-PET/CT (72.5% vs. 67.5%). No significant difference was found in the number of metastatic axillary lymph nodes. Compared with MR-mammography, mammo-PET/CT provided more correct classification of the focality of lesion than did MR-mammography (95% vs. 90%). In the T-stage, 72.5% of cases with mammo-PET/CT and 70% of cases with MR-mammography showed correspondence with pathologic results. Conclusions Mammo-PET/CT provided more correct definition of the T-stage and evaluation of axillary fossa may also be delineated more clearly than with supine

  12. Absolute Quantitation of Myocardial Blood Flow in Human Subjects with or without Myocardial Ischemia using Dynamic Flurpiridaz F 18 Positron Emission Tomography

    PubMed Central

    Packard, René R. S.; Huang, Sung-Cheng; Dahlbom, Magnus; Czernin, Johannes; Maddahi, Jamshid

    2015-01-01

    Absolute quantitation of myocardial blood flow (MBF) by positron emission tomography (PET) is an established method of analyzing coronary artery disease (CAD) but subject to the various shortcomings of available radiotracers. Flurpiridaz F 18 is a novel PET radiotracer which exhibits properties of an ideal tracer. Methods A new absolute perfusion quantitation method with Flurpiridaz was developed, taking advantage of the early kinetics and high first-pass extraction by the myocardium of this radiotracer, and the first in human measurements of MBF performed in 7 normal subjects and 8 patients with documented CAD. PET images with time-activity curves were acquired at rest and during adenosine stress. Results In normal subjects, regional MBF between coronary artery territories did not differ significantly, leading to a mean global MBF of 0.73 mL/min/g at rest and 2.53 mL/min/g during stress, with a mean global myocardial flow reserve (MFR) of 3.70. CAD vascular territories with <50% stenosis demonstrated a mean MBF of 0.73 at rest and 2.02 during stress, leading to a mean MFR of 2.97. CAD vascular territories with ≥50% stenosis exhibited a mean MBF of 0.86 at rest and 1.43 during stress, leading to a mean MFR of 1.86. Differences in stress MBF and MFR between normal and CAD territories, as well as between <50% and ≥50% stenosis vascular territories, were significant (P<0.01). Conclusion Absolute quantitation of MBF in humans with the novel PET radiotracer Flurpiridaz is feasible over a wide range of cardiac flow in the presence or absence of stress-inducible myocardial ischemia. The significant decrease in stress MBF and ensuing MFR in CAD territories allows a clear distinction between vascular territories exhibiting stress-inducible myocardial ischemia and those with normal perfusion. PMID:25071096

  13. 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.

  14. 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

  15. 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 Central

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

    2015-01-01

    Abstract 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

  16. Clinical evaluation of thallium-201 SPECT for the detection and differentiation of gliomas: A comparative study with C-11 methionine and F-18 FDG PET

    SciTech Connect

    Sasaki, M.; Ichiya, Y.; Kuwabara, Y.

    1994-05-01

    The aim of this study is to evaluate thallium (Tl)-SPECT in the detection and differentiation of gliomas and then to compare it with the results of methionine (MET)-PET and FDG-PET. We examined 8 patients with gliomas including 3 patients with astrocytoma grade-II, 3 with anaplastic astrocytoma grade-III, 1 with glioblastoma and 1 with malignant oligodendroglioma. A glioblastoma and a malignant oligodendroglioma were grouped together as highly malignant gliomas. The Tl-SPECT images were obtained by GCA9300A 15 minutes after the administration of 148 MBq of thallium. The SPECT images were graded as negative, positive and intensely positive according to the focal thallium uptake in the tumor. Both the MET-PET and FDG-pet were examined by HEADTOME III one hour after the administration of 148-851 MBq of radiopharmaceuticals. Thereafter the standard uptake value (SUV) of MET and FDG were determined. One out of the 3 patients with astrocytoma grade-II and 3 out of the 3 with anaplastic astroycytoma grade-III were positive on Tl-SPECT. Two out of the 2 patients with highly malignant gliomas were intensely positive on Tl-SPECT. The mean SUV of MET for astrocytoma grade-II with negative Tl-SPECT was 0.92, for astrocytoma grade-II with positive Tl-SPECT it was 1.57, for anaplastic astrocytoma grade-III it was 3.02 and for highly malignant glioma it was 3.55. On the other hand, those of FDG were 3.02,4.41,2.25 and 3.70, respectively. In conclusion, Tl-SPECT was found to be as sensitive as MET-PET for detecting gliomas. The grade of Tl accumulation and the SUV of MET demonstrated a positive correlation with the histological grade of gliomas.

  17. Detection of lung cancer in patients with pneumoconiosis by fluorodeoxyglucose-positron emission tomography/computed tomography: four cases.

    PubMed

    Yu, Hua; Zhang, Hua; Wang, Yanli; Cui, Xinjian; Han, Jiankui

    2013-01-01

    We report 4 cases of lung cancer in patients with pneumoconiosis detected by F18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT), which could differentiate lung cancer and pneumoconiosis. FDG-PET/CT may be useful in cancer screening for patients with pneumoconiosis. PMID:23369632

  18. Both F-18 FDG-avidity and Malignant Shape of Cervical Lymph Nodes on PET/CT after Total Thyroidectomy Predict Resistance to High-dose I-131 Therapy in Patients with Papillary Thyroid Cancer

    PubMed Central

    Byun, Byung Hyun; Kwon, Seong Young; Chong, Ari; Kim, Jahae; Yoo, Su Woong; Min, Jung-Joon; Song, Ho-Chun; Bom, Henry Hee-Seung

    2013-01-01

    Objective: Resistance of metastatic lymph nodes (LNs) to high dose I-131 therapy is associated with high morbidity in patients with differentiated thyroid cancer. We evaluated the role of F-18 FDG PET/CT in the prediction of resistance to high dose I-131 therapy in patients with papillary thyroid cancer. Methods: The subjects were 307 patients who underwent total or near total thyroidectomy followed by high dose (5.55-6.66 GBq) I-131 therapy. We divided the patients into three subgroups by visual assessment of regional LNs: FDG-avid LNs with a malignant shape on CT (PET/CT-positive group), FDG-avid LNs with a benign shape on CT (PET/CT-intermediate group) and no FDG-avid lesion (PET/CT-negative group). We measured the maximum SUV (SUVmax) of FDG-avid LNs in each patient. The presence or absence of focal increased uptake of I-131 was evaluated by whole body scan (WBS), and was denoted as WBS-positive group or WBS-negative group, respectively. Resistance to therapy was defined as presence of thyroglobulin (Tg) in serum (Tg ≥1.0 ng/ml) 3-6 months after I-131 therapy. Univariate and multivariate analyses were performed to determine the relationship between resistance to I-131 therapy and various clinico-pathologic variables. Results: PET/CT-positive, intermediate, and negative groups included 20 (6.5%), 44 (14.3%) and 243 (79.2%) patients, respectively. The mean SUVmax was significantly higher in the PET/CT-positive group than that of the PET/CT-intermediate group (4.6 vs. 2.7, P <0.001). Univariate analysis revealed that the PET/CT-positive group (P <0.001), T2-4 stage (P <0.001), N1b stage (P = 0.001), lower dose (5.55 GBq) of I-131 (P <0.001), and the WBS-positive group (P = 0.029) were associated with resistance to therapy. In multivariate analysis, the PET/CT-positive group, lower dose of I-131, N1b stage, and T2-4 stage remained significant with odds ratios of 10.07 (P <0.001), 3.82 (P <0.001), 3.58 (P = 0.001), and 2.53 (P = 0.009), respectively. Conclusion

  19. Caged [(18)F]FDG Glycosylamines for Imaging Acidic Tumor Microenvironments Using Positron Emission Tomography.

    PubMed

    Flavell, Robert R; Truillet, Charles; Regan, Melanie K; Ganguly, Tanushree; Blecha, Joseph E; Kurhanewicz, John; VanBrocklin, Henry F; Keshari, Kayvan R; Chang, Christopher J; Evans, Michael J; Wilson, David M

    2016-01-20

    Solid tumors are hypoxic with altered metabolism, resulting in secretion of acids into the extracellular matrix and lower relative pH, a feature associated with local invasion and metastasis. Therapeutic and diagnostic agents responsive to this microenvironment may improve tumor-specific delivery. Therefore, we pursued a general strategy whereby caged small-molecule drugs or imaging agents liberate their parent compounds in regions of low interstitial pH. In this manuscript, we present a new acid-labile prodrug method based on the glycosylamine linkage, and its application to a class of positron emission tomography (PET) imaging tracers, termed [(18)F]FDG amines. [(18)F]FDG amines operate via a proposed two-step mechanism, in which an acid-labile precursor decomposes to form the common radiotracer 2-deoxy-2-[(18)F]fluoro-d-glucose, which is subsequently accumulated by glucose avid cells. The rate of decomposition of [(18)F]FDG amines is tunable in a systematic fashion, tracking the pKa of the parent amine. In vivo, a 4-phenylbenzylamine [(18)F]FDG amine congener showed greater relative accumulation in tumors over benign tissue, which could be attenuated upon tumor alkalinization using previously validated models, including sodium bicarbonate treatment, or overexpression of carbonic anhydrase. This new class of PET tracer represents a viable approach for imaging acidic interstitial pH with potential for clinical translation. PMID:26649808

  20. 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.

  1. F-18 HARV cockpit

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The F-18 HARV retains the basic F-18 cockpit controls with some exceptions. The pilot's center control stick is relatively typical of a modern fighter aircraft. The F-18 HARV has no weapons delivery capability. Independent throttling of the left or right engine is possible through split throttle levers located on the left console. The pilot's friction control is provided for adjustment of throttle lever force. The three-position (extend, hold, and retract) speed brake thumb switch is located on the inboard side of the right-engine throttle lever. 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, RFCS status, 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 HARV systems. These displays are pilot selectable and menu driven. Various aerodynamic research experiments were conducted on the F-18 HARV. Switches for control of these experiments were located on the research systems control panel located at the lower center of the instrument panel. These switches operated in conjunction with the gun trigger switch. The configuration of this panel and the function of the gun trigger switch varied with the particular experiment flown.

  2. 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.

  3. Evidence for a caudate role in aphasia from FDG positron emission tomography

    SciTech Connect

    Metter, E.J.; Riege, W.H.; Hanson, W.R.; Phelps, M.; Kuhl, D.E.

    1982-01-01

    In a recent study correlations between language function and regional glucose metabolism from FDG positron computed tomography were examined. Caudate metabolism correlated with PICA speaking and comprehension factors, as well as BDAE mean writing and reading scores. To identify the language function implicated with caudate metabolism in these eleven patients, twenty subtests making up these two PICA factors and mean BDAE scores were correlated to caudate metabolism. Also a principle components analysis on the twenty subtests identified three factors, only one of which correlated with caudate metabolism. Evidence was found that the caudate has a functional relationship to recognition or motor planning of simple and overlearned materials. This involved simple syntax, low levels of abstraction, identification or sequencing of phonetic and semantic material. This role appeared related to but independent of Broca and frontal lobe function, and may involve the focusing of cortical functions, by allowing two or more regions to interact together.

  4. F-18-fluoro-2-deoxyglucose positron emission tomography (PET) and PET/computed tomography imaging in primary staging of patients with malignant melanoma: a systematic review

    PubMed Central

    2012-01-01

    Purpose The aim of this systematic review was to systematically assess the potential patient-relevant benefit (primary aim) and diagnostic and prognostic accuracy (secondary aim) of positron emission tomography (PET) and PET/computed tomography (CT) in primary staging of malignant melanoma. This systematic review updates the previous evidence for PET(/CT) in malignant melanoma. Materials and methods For the first aim, randomized controlled trials (RCTs) investigating patient-relevant outcomes and comparing PET and PET(/CT) with each other or with conventional imaging were considered. For the secondary aim, a review of reviews was conducted, which was amended by an update search for primary studies. MEDLINE, EMBASE and four databases of the Cochrane Library were searched. The risk of bias was assessed using a modified QUADAS tool. Results No RCTs investigating the patient-relevant benefit of PET(/CT) and no prognostic accuracy studies were found. Seventeen diagnostic accuracy studies of varying quality were identified. For patients with American Joint Committee on Cancer (AJCC) stages I and II, sensitivity mostly ranged from 0 to 67%. Specificity ranged from 77 to 100%. For AJCC stages III and IV, sensitivity ranged from 68 to 87% and specificity from 92 to 98%. Conclusion There is currently no evidence of a patient-relevant benefit of PET(/CT) in the primary staging of malignant melanoma. RCTs investigating patient-relevant outcomes are therefore required. The diagnostic accuracy of PET(/CT) appears to increase with higher AJCC stages. PMID:23237499

  5. Diagnostic FDG and FDOPA positron emission tomography scans distinguish the genomic type and treatment outcome of neuroblastoma

    PubMed Central

    Chang, Hsiu-Hao; Lu, Ching-Chu; Lin, Dong-Tsamn; Jou, Shiann-Tarng; Yang, Yung-Li; Lee, Ya-Ling; Huang, Shiu-Feng; Jeng, Yung-Ming; Lee, Hsinyu; Miser, James S.; Lin, Kai-Hsin; Liao, Yung-Feng; Hsu, Wen-Ming; Tzen, Kai-Yuan

    2016-01-01

    Neuroblastoma (NB) is a heterogeneous childhood cancer that requires multiple imaging modalities for accurate staging and surveillances. This study aims to investigate the utility of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) and 18F-fluoro-dihydroxyphenylalanine (FDOPA) in determining the prognosis of NB. During 2007–2014, forty-two NB patients (male:female, 28:14; median age, 2.0 years) undergoing paired FDG and FDOPA PET scans at diagnosis were evaluated for the maximum standardized uptake value (SUVmax) of FDG or FDOPA by the primary tumor. Patients with older age, advanced stages, or MYCN amplification showed higher FDG and lower FDOPA SUVmax (all P < 0.02). Receiver operating characteristics analysis identified FDG SUVmax≥ 3.31 and FDOPA SUVmax < 4.12 as an ultra-high-risk feature (PET-UHR) that distinguished the most unfavorable genomic types, i.e. segmental chromosomal alterations and/or MYCN amplification, at a sensitivity of 81.3% (54.4%–96.0%) and a specificity of 93.3% (68.1%–99.8%). Considering with age, stage, MYCN status, and anatomical image-defined risk factor, PET-UHR was an independent predictor of inferior event-free survival (multivariate hazard ratio, 4.9 [1.9–30.1]; P = 0.012). Meanwhile, the ratio between FDG and FDOPA SUVmax (G:D) correlated positively with HK2 (Spearman's ρ = 0.86, P < 0.0001) and negatively with DDC (ρ = −0.58, P = 0.02) gene expression levels, which might suggest higher glycolytic activity and less catecholaminergic differentiation in NB tumors taking up higher FDG and lower FDOPA. In conclusion, the intensity of FDG and FDOPA uptake on diagnostic PET scans may predict the tumor behavior and complement the current risk stratification systems of NB. PMID:26959748

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

    PubMed Central

    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. PMID:26917909

  7. 18F-fluorodeoxy-glucose positron emission tomography (18FDG-PET) marks MYC-overexpressing human basal-like breast cancers

    PubMed Central

    Palaskas, Nicolaos; Larson, Steven M.; Schultz, Nikolaus; Komisopoulou, Evangelia; Wong, Justin; Rohle, Dan; Campos, Carl; Yannuzzi, Nicolas; Osborne, Joseph R.; Linkov, Irina; Kastenhuber, Edward R.; Taschereau, Richard; Plaisier, Seema B.; Tran, Chris; Heguy, Adriana; Wu, Hong; Sander, Chris; Phelps, Michael E.; Brennan, Cameron; Port, Elisa; Huse, Jason T.; Graeber, Thomas G.; Mellinghoff, Ingo K.

    2011-01-01

    In contrast to normal cells, cancer cells avidly take up glucose and metabolize it to lactate even when oxygen is abundant, a phenomenon referred to as the Warburg effect. This fundamental alteration in glucose metabolism in cancer cells enables their specific detection by Positron Emission Tomography (PET) following intravenous injection of the glucose analogue 18F-fluorodeoxy-glucose (18FDG). However, this useful imaging technique is limited by the fact that not all cancers avidly take up FDG. To identify molecular determinants of 18FDG-retention, we interogated the transcriptomes of human cancer cell lines and primary tumors for metabolic pathways associated with 18FDG radiotracer uptake. From 95 metabolic pathways that were interrogated, the glycolysis and several glycolysis-related pathways (pentose-phosphate, carbon fixation, aminoacyl-tRNA biosynthesis, one-carbon-pool by folate) showed the greatest transcriptional enrichment. This “FDG signature” predicted FDG-uptake in breast cancer cell lines and overlapped with established gene expression signatures for the “basal-like” breast cancer subtype and MYC-induced tumorigenesis in mice. Human breast cancers with nuclear MYC staining and high RNA expression of MYC target genes showed high 18FDG-PET uptake (p < 0.005). Presence of the FDG signature was similarly associated with MYC gene copy gain, increased MYC transcript levels, and elevated expression of metabolic MYC target genes in a human breast cancer genomic dataset. Together, our findings link clinical observations of glucose uptake with a pathologic and molecular subtype of human breast cancer. Further, they suggest related approaches to derive molecular determinants of radiotracer retention for other PET-imaging probes. PMID:21646475

  8. The influence of tumor oxygenation on 18F-FDG (Fluorine-18 Deoxyglucose) uptake: A mouse study using positron emission tomography (PET)

    PubMed Central

    Chan, Linda W; Hapdey, Sebastien; English, Sean; Seidel, Jurgen; Carson, Joann; Sowers, Anastasia L; Krishna, Murali C; Green, Michael V; Mitchell, James B; Bacharach, Stephen L

    2006-01-01

    Background This study investigated whether changing a tumor's oxygenation would alter tumor metabolism, and thus uptake of 18F-FDG (fluorine-18 deoxyglucose), a marker for glucose metabolism using positron emission tomography (PET). Results Tumor-bearing mice (squamous cell carcinoma) maintained at 37°C were studied while breathing either normal air or carbogen (95% O2, 5% CO2), known to significantly oxygenate tumors. Tumor activity was measured within an automatically determined volume of interest (VOI). Activity was corrected for the arterial input function as estimated from image and blood-derived data. Tumor FDG uptake was initially evaluated for tumor-bearing animals breathing only air (2 animals) or only carbogen (2 animals). Subsequently, 5 animals were studied using two sequential 18F-FDG injections administered to the same tumor-bearing mouse, 60 min apart; the first injection on one gas (air or carbogen) and the second on the other gas. When examining the entire tumor VOI, there was no significant difference of 18F-FDG uptake between mice breathing either air or carbogen (i.e. air/carbogen ratio near unity). However, when only the highest 18F-FDG uptake regions of the tumor were considered (small VOIs), there was a modest (21%), but significant increase in the air/carbogen ratio suggesting that in these potentially most hypoxic regions of the tumor, 18F-FDG uptake and hence glucose metabolism, may be reduced by increasing tumor oxygenation. Conclusion Tumor 18F-FDG uptake may be reduced by increases in tumor oxygenation and thus may provide a means to further enhance 18F-FDG functional imaging. PMID:16722588

  9. Image findings of monomorphic non-hogdkin lymphoproliferative disorder in a post renal transplant patient diagnosed with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography

    PubMed Central

    Kamaleshwaran, Koramadai Karuppusamy; Rajasekar, Thirugnanam; Shibu, Deepu; Radhakrishnan, Edathurthy Kalarikal; Shinto, Ajit Sugunan

    2014-01-01

    Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous group of lymphoid proliferations caused by immunosuppression after solid organ or bone marrow transplantation. PTLD is categorized by early lesion, polymorphic PTLD and monomorphic PTLD. Fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) scans have clinical significance in the evaluation of PTLD following renal transplantation. We report imaging findings of a monomorphic non-Hodgkin lymphoma, post renal transplant seen on FDG PET/CT in a 32-year-old lactating woman. Whole body FDG- ET/CT demonstrated uptake in right external iliac and inguinal lymph nodes. PMID:25210292

  10. Image findings of monomorphic non-hogdkin lymphoproliferative disorder in a post renal transplant patient diagnosed with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography.

    PubMed

    Kamaleshwaran, Koramadai Karuppusamy; Rajasekar, Thirugnanam; Shibu, Deepu; Radhakrishnan, Edathurthy Kalarikal; Shinto, Ajit Sugunan

    2014-07-01

    Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous group of lymphoid proliferations caused by immunosuppression after solid organ or bone marrow transplantation. PTLD is categorized by early lesion, polymorphic PTLD and monomorphic PTLD. Fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) scans have clinical significance in the evaluation of PTLD following renal transplantation. We report imaging findings of a monomorphic non-Hodgkin lymphoma, post renal transplant seen on FDG PET/CT in a 32-year-old lactating woman. Whole body FDG- ET/CT demonstrated uptake in right external iliac and inguinal lymph nodes. PMID:25210292

  11. 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

  12. Maturational changes in cerebral function in infants determined by /sup 18/FDG positron emission tomography

    SciTech Connect

    Chugani, H.T.; Phelps, M.E.

    1986-02-21

    2-Deoxy-2(/sup 18/F)fluro-D-glucose positron emission tomography performed in human infants during development revealed progressive changes in local cerebral glucose utilization. In infants 5 weeks of age and younger, glucose utilization was highest in the sensorimotor cortex, thalamus, midbrain-brainstem, and cerebellar vermis. By 3 months, glucose metabolic activity had increased in the parietal, temporal, and occipital cortices and the basal ganglia, with subsequent increases in frontal and various association regions occurring by 8 months. These functional changes measured with positron emission tomography are in agreement with behavioral, neurophysiological, and anatomical alterations known to occur during infant development. 32 references, 2 figures, 1 table.

  13. 18F-FLT Positron Emission Tomography/Computed Tomography Imaging in Pancreatic Cancer: Determination of Tumor Proliferative Activity and Comparison with Glycolytic Activity as Measured by 18F-FDG Positron Emission Tomography/Computed Tomography Imaging

    PubMed Central

    Debebe, Senait Aknaw; Goryawala, Mohammed; Adjouadi, Malek; Mcgoron, Anthony J.; Güleç, Seza A.

    2016-01-01

    Objective: This phase-I imaging study examined the imaging characteristic of 3’-deoxy-3’-(18F)-fluorothymidine (18F-FLT) positron emission tomography (PET) in patients with pancreatic cancer and comparisons were made with (18F)-fluorodeoxyglucose (18F-FDG). The ultimate aim was to develop a molecular imaging tool that could better define the biologic characteristics of pancreas cancer, and to identify the patients who could potentially benefit from surgical resection who were deemed inoperable by conventional means of staging. Methods: Six patients with newly diagnosed pancreatic cancer underwent a combined FLT and FDG computed tomography (CT) PET/CT imaging protocol. The FLT PET/CT scan was performed within 1 week of FDG PET/CT imaging. Tumor uptake of a tracer was determined and compared using various techniques; statistical thresholding (z score=2.5), and fixed standardized uptake value (SUV) thresholds of 1.4 and 2.5, and applying a threshold of 40% of maximum SUV (SUVmax) and mean SUV (SUVmean). The correlation of functional tumor volumes (FTV) between 18F-FDG and 18F-FLT was assessed using linear regression analysis. Results: It was found that there is a correlation in FTV due to metabolic and proliferation activity when using a threshold of SUV 2.5 for FDG and 1.4 for FLT (r=0.698, p=ns), but a better correlation was obtained when using SUV of 2.5 for both tracers (r=0.698, p=ns). The z score thresholding (z=2.5) method showed lower correlation between the FTVs (r=0.698, p=ns) of FDG and FLT PET. Conclusion: Different tumor segmentation techniques yielded varying degrees of correlation in FTV between FLT and FDG-PET images. FLT imaging may have a different meaning in determining tumor biology and prognosis. PMID:27299286

  14. Comparison of the Prognostic Value of F-18 Pet Metabolic Parameters of Primary Tumors and Regional Lymph Nodes in Patients with Locally Advanced Cervical Cancer Who Are Treated with Concurrent Chemoradiotherapy

    PubMed Central

    Chong, Gun Oh; Jeong, Shin Young; Park, Shin-Hyung; Lee, Yoon Hee; Lee, Sang-Woo; Hong, Dae Gy; Kim, Jae-Chul; Lee, Yoon Soon; Cho, Young Lae

    2015-01-01

    Objective This study investigated the metabolic parameters of primary tumors and regional lymph nodes, as measured by pre-treatment F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) to compare the prognostic value for the prediction of tumor recurrence. This study also identified the most powerful parameter in patients with locally advanced cervical cancer treated with concurrent chemoradiotherapy. Methods Fifty-six patients who were diagnosed with cervical cancer with pelvic and/or paraaortic lymph node metastasis were enrolled in this study. Metabolic parameters including the maximum standardized uptake value (SUVmax), the metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumors and lymph nodes were measured by pre-treatment F-18 FDG PET/CT. Univariate and multivariate analyses for disease-free survival (DFS) were performed using the clinical and metabolic parameters. Results The metabolic parameters of the primary tumors were not associated with DFS. However, DFS was significantly longer in patients with low values of nodal metabolic parameters than in those with high values of nodal metabolic parameters. A univariate analysis revealed that nodal metabolic parameters (SUVmax, MTV and TLG), paraaortic lymph node metastasis, and post-treatment response correlated significantly with DFS. Among these parameters, nodal SUVmax (hazard ratio [HR], 4.158; 95% confidence interval [CI], 1.1–22.7; p = 0.041) and post-treatment response (HR, 7.162; 95% CI, 1.5–11.3; p = 0.007) were found to be determinants of DFS according to a multivariate analysis. Only nodal SUVmax was an independent pre-treatment prognostic factor for DFS, and the optimal cutoff for nodal SUVmax to predict progression was 4.7. Conclusion Nodal SUVmax according to pre-treatment F-18 FDG PET/CT may be a prognostic biomarker for the prediction of disease recurrence in patients with locally advanced cervical cancer. PMID:26368542

  15. 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.

  16. 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.

  17. Diagnostic utility of FDG-PET in neurolymphomatosis: report of five cases.

    PubMed

    Kinoshita, Hisanori; Yamakado, Hodaka; Kitano, Toshiyuki; Kitamura, Akihiro; Yamashita, Hirofumi; Miyamoto, Masakazu; Hitomi, Takefumi; Okada, Tomohisa; Nakamoto, Yuji; Sawamoto, Nobukatsu; Takaori-Kondo, Akifumi; Takahashi, Ryosuke

    2016-09-01

    Neurolymphomatosis (NL) is a rare condition involving the infiltration of lymphoma cells into the peripheral nervous system. NL can be primary or secondary in the setting of an unknown or known hematologic malignancy, respectively. Here, we report five cases in which F-18 2-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (F-18 FDG-PET/CT) had great value for diagnosing NL. Two cases were rare primary NL, and the other three were secondary NL. Clinical presentations were asymmetric sensorimotor disturbances in the extremities with or without involvement of cranial nerves. Furthermore, all patients experienced spontaneous pain in the face or affected extremities. Cerebrospinal fluid analysis was cytologically negative in two of five cases. Gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) detected abnormalities in the cranial nerves, nerve roots, and cauda equina in all cases except case 1 and the recurrent stage of case 2. F-18 FDG-PET/CT showed clear visualization of almost all the lymphomatous involvement of peripheral nerves and other tissues in all patients. Furthermore, F-18 FDG-PET/CT detected abnormalities including asymptomatic lesions that were not detected with MRI, and also identified the appropriate lesion for diagnostic biopsy. However, as in case 3, the lesions in the left oculomotor nerve and the cauda equina were detected only with Gd-enhanced MRI, which has superior spatial resolution. In conclusion, F-18 FDG-PET/CT is a sensitive modality that can suggest the presence of malignancy and identify appropriate places for diagnostic biopsies. It is especially useful when combined with Gd-enhanced MRI, even in patients with primary NL that is usually difficult to diagnose. PMID:27286845

  18. Extrapulmonary Small Cell Carcinoma of the Seminal Vesicles and Prostate Demonstrated on 18F-FDG Positron Emission Tomography/Computed Tomography

    PubMed Central

    Tabrizipour, Amir Iravani; Shen, Lily; Mansberg, Robert; Chuong, Bui

    2016-01-01

    Extrapulmonary primary small cell carcinomas arising from the urogenital tract is infrequent. It can rarely arise from the prostate and even more rarely from the seminal vesicles. We present a 79-year-old male who was admitted due to acute renal failure with a history of radical radiotherapy for prostate adenocarcinoma 13 years ago. The prostate specific antigen level was not elevated. An abdominopelvic computed tomography (CT) scan showed markedly enlarged seminal vesicles causing bilateral ureteral obstruction and a mildly enlarged prostate. Further evaluation with fluorine-18-fluorodeoxyglucose (0F-FDG) positron emission tomography/CT demonstrated extensive 18F-FDG uptake in the pelvis with diffuse involvement of both seminal vesicles and the prostate without pathologic uptake in the lungs or elsewhere in the body. Core biopsies of the prostate and both seminal vesicles revealed diffuse involvement by small cell carcinoma. Therapy could not be instituted due to a rapid deterioration in the patient’s clinical condition.

  19. 18F-FDG positron emission tomography in oncology: main indications.

    PubMed

    Vercher-Conejero, J L; Gámez Cenzano, C

    2016-01-01

    The development of molecular and functional imaging with new imaging techniques such as computed tomography, magnetic resonance imaging, and positron emission tomography (PET) among others, has greatly improved the detection of tumors, tumor staging, and the detection of possible recurrences. Furthermore, the combination of these different imaging modalities and the continual development of radiotracers for PET have advanced our understanding and knowledge of the different pathophysiological processes in cancer, thereby helping to make treatment more efficacious, improving patients' quality of life, and increasing survival. PET is one of the imaging techniques that has attracted the most interest in recent years for its diagnostic capabilities. Its ability to anatomically locate pathologic foci of metabolic activity has revolutionized the detection and staging of many tumors, exponentially broadening its potential indications not only in oncology but also in other fields such as cardiology, neurology, and inflammatory and infectious diseases. PMID:27184919

  20. The role of 18F-FDG positron emission tomography in the follow-up of liver tumors treated with 90Yttrium radioembolization

    PubMed Central

    Bagni, Oreste; Filippi, Luca; Schillaci, Orazio

    2015-01-01

    In the last years, radioembolization (RE) has emerged as a novel technique for the treatment of malignant hepatic lesions using 90Y embedded in spheres, which are infused directly into the hepatic arterial circulation. 90Y-spheres, once implanted in liver, can release a significant radiation burden to neoplastic cells with a relative low dose to normal parenchyma. 90Y RE results as a combination of embolization and radiation therapy, thus the standard radiologic follow up modalities may be not sufficiently accurate to assess tumor response to treatment. 18Fluoro-deoxyglucose Positron Emission Tomography (18F-FDG PET) detects glucose uptake and metabolic activity in tumor cells. 18F-FDG PET has become a well established diagnostic tool in many oncological scenarios. Furthermore, PET response criteria (PERCIST) have been recently introduced to categorize the metabolic response to therapy of cancer patients. Several semiquantitative parameters, such as SUVmax and its changes, the Functional Tumor Volume and the Total Lesion Glycolysis can be useful to accurately assess tumor changes after therapy. The purpose of this article is to present the literature on the role of 18F-FDG PET in the evaluation of patients with primary and secondary liver tumors treated with 90Y RE. PMID:26069856

  1. [{sup 18}F]FDG-Positron Emission Tomography Coregistration With Computed Tomography Scans for Radiation Treatment Planning of Lymphoma and Hematologic Malignancies

    SciTech Connect

    Terezakis, Stephanie A.; Hunt, Margie A.; Kowalski, Alexander; McCann, Patrick; Schmidtlein, C. Ross; Reiner, Anne; Goenen, Mithat; Kirov, Assen S.; Gonzales, Anne Marie; Schoeder, Heiko; Yahalom, Joachim

    2011-11-01

    Purpose: Positron emission-tomography (PET) using 2-[{sup 18}F]fluoro-2-deoxyglucose (FDG-PET) increases sensitivity and specificity of disease detection in lymphoma and thus is standard in lymphoma management. This study examines the effects of coregistering FDG-PET and computed tomography (CT) (PET/CT) scans on treatment planning for lymphoma patients. Methods and Materials: Twenty-nine patients (30 positive PET scans) underwent PET/CT treatment planning from July 2004 to February 2007 and were retrospectively studied. For each patient, gross tumor volume was blindly contoured on the CT-only and PET/CT studies by a radiation oncologist. Treatment plans were generated for both the CT-only and PET/CT planning target volumes (PTVs) for all patients. Normal tissue doses and PTV coverage were evaluated using dose--volume histograms for all sites. Results: Thirty-two treatment sites were evaluated. Twenty-one patients had non-Hodgkin lymphoma, 5 patients had Hodgkin lymphoma, and 3 patients had plasma cell neoplasms. Previously undetected FDG-avid sites were identified in 3 patients during PET/CT simulation, resulting in one additional treatment field. Due to unexpected PET/CT simulation findings, 2 patients did not proceed with radiation treatment. The addition of PET changed the volume of 23 sites (72%). The PTV was increased in 15 sites (47%) by a median of 11% (range, 6-40%) and reduced in 8 sites (25%) by a median of 20% (range, 6%-75%). In six (19%) replanned sites, the CT-based treatment plan would not have adequately covered the PTV defined by PET/CT. Conclusions: Incorporation of FDG-PET into CT-based treatment planning for lymphoma patients resulted in considerable changes in management, volume definition, and normal tissue dosimetry for a significant number of patients.

  2. Using 18F Fluorodeoxyglucose Positron Emission Tomography (FDG PET) to Monitor Clinical Outcomes in Patients Treated with Neoadjuvant Chemo-Radiotherapy for Locally Advanced Pancreatic Cancer

    PubMed Central

    Choi, Minsig; Heilbrun, Lance K.; Venkatramanamoorthy, Raghu; Lawhorn-Crews, Jawana M.; Zalupski, Mark M.; Shields, Anthony F.

    2013-01-01

    BACKGROUND Pancreatic cancer ranks as the fourth leading cause of cancer death in the United States with five year survival ranging from 1-5%. Positron emission tomography (PET) is a metabolic imaging system that is widely used for the initial staging of cancer and detecting residual disease after treatment. There are limited data, however, on the use of this molecular imaging technique to assess early tumor response after treatment in pancreatic cancer. METHODS The objective of the study was to explore the relationship of early treatment response using the 18 F- fluorodeoxyglucose (FDG) PET with surgical outcome and overall survival in patients with locally advanced pancreatic cancer. FDG-PET measurements of maximum standardized uptake value (SUV) and kinetic parameters were compared to the clinical outcome. RESULTS Twenty patients were enrolled in the study evaluating neoadjuvant induction chemotherapy followed by concurrent chemoradiotherapy (chemo-RT) for locally advanced pancreatic cancer. All twenty patients had pre-study PET scans and a total of fifty PET scans were performed. Among patients who were PET responders (≥50% decrease in SUV after cycle 1), 100% (2/2) had complete surgical resection. Only 6% (1/16) had surgical resection in the PET non-responders (<50% decrease). Two patients did not have the second PET scan due to clinical progression or treatment toxicity. Mean survival was 23.2 months for PET responders and 11.3 months for non-responders (p=0.234). Similar differences in survival were also noted when response was measured using Patlak analysis. CONCLUSION FDG-PET can aid in monitoring the clinical outcome of patients with locally advanced pancreatic cancer treated with neoadjuvant chemo-RT. FDG-PET may be used to aid patients who could have complete surgical resection as well as prognosticate patients’ survival. PMID:19806035

  3. Regional brain distribution of 2-deoxy-2-[F-18]Fluoro-D-talose: A new PET tracer for measurement of galactokinase activity

    SciTech Connect

    Haradahira, T.; Inoue, O.; Suzuki, K.

    1994-05-01

    We have recently developed a 2-deoxy-2-[F-18]fluoro-D-talose (2-[F-18]FDTal) as a new PET tracer for measurements of galactokinase activities in tissues. The rational of 2-[F-18]FDTal as a PET tracer is based on the metabolic trapping by a formation of 2-[F-18]FDTal-1-phosphate by galactokinase. In this study, we have examined the regional brain distribution of 2-[F-18]FDTal in monkey by PET, and compared it with those of 2-deoxy-2-[F-18]fluoro-D-glucose (2-[F-18]FDG) and 2-deoxy-2-[F-18]fluoro-D-galactose (2-[F-18]FDTal), PET tracers for D-glucose and D-galactose metabolisms, respectively. The F-18 sugars used for the PET studies were prepared through nucleophilic fluorinations of the corresponding triflates with [F-18]fluoride. PET imaging obtained by i.v. injection of 2-[F-18]FDTal in rhesus monkey showed very high accumulation of the radioactivity into an occipital cortex region. This regional distribution was very similar to that of 2-[F-18]FDGal, but was quite different with that of 2-[F-18]FDG. In PET data analyses, washout of the radioactivity from the occipital cortex (30% loss of the initial activity) was observed in an early period ({<=}5 min) after injection of 2-[F-18]FDTal, in contrast with the continuous increase of the radioactivity in the same region after injection of 2-[F-18]FDGal. This data indicates a smaller phosphorylation rate constant (K3) of 2-[F-18]FDTal by brain galactokinase than that of 2-[F-18]FDGal. 2-[F-18]FDGal has been reported to be partly metabolized into an UDP-2-[F-18]FDGal via 2-CF-18]FDGal-l-phosphate in animal brains. Therefore 2-[F-18]FDTal offers an advantage over 2-[F-18]FDGal in undergoing its simple metabolism which enables us to make a simple kinetic model for PET imaging. We conclude that 2-[F-18]FDTal may be a new PET tracer to give a characteristic regional brain distribution which reflect the regional galactokinase activity.

  4. Positron-emission tomography pitfalls related to oral prosthesis.

    PubMed

    More, Yogesh; Dusing, Reginald; Counts, Shaheen; Bond, Justin; Tsue, Terrance; Girod, Douglas

    2013-02-01

    This case report describes false-positive positron-emission tomography/computed tomography (PET/CT) findings related to oral prostheses and its implications in cancer surveillance. In head and neck cancer management, F18-flurodeoxyglucose (FDG) PET/CT is widely accepted for evaluating treatment response and detecting recurrence. Interpretation of FDG PET/CT images in this setting is often challenging due to various prostheses and reconstruction methods. Following surgery for squamous cell carcinoma of the maxillary alveolus, a 61-year-old female had a FDG PET/CT scan on a 7-month follow-up that showed high FDG uptake along the resection site. Clinical examination showed no signs of inflammation or recurrence. Repeat FDG PET/CT without the prosthesis was normal. The PET/CT attenuation-corrected images demonstrated high FDG uptake (standardized uptake value: 11.6) along the resection site corresponding to contrast-enhanced CT images of the lesion. PET/CT nonattenuation-corrected images also confirmed increased activity. Repeat PET/CT without the prosthesis was normal. FDG is not tumor specific; it can accumulate in inflammation, infection, and post-therapy settings. Metallic and high-density prostheses show radial artifacts on CT and falsely elevated FDG uptake on PET/ CT in adjacent areas. Salivary pooling may concentrate FDG. The presence of oral prostheses has not been described as a cause of this high level of activity. PET/CT images that demonstrate intense activity corresponding to dense structures should be viewed with caution. A detailed history and physical exam as well as knowledge of artifacts are pertinent for the managing physician. Laryngoscope, 2012. PMID:22778055

  5. 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.

  6. A Novel Method to Evaluate Local Control of Lung Cancer in Stereotactic Body Radiation Therapy (SBRT) Treatment Using 18F-FDG Positron Emission Tomography (PET)

    NASA Astrophysics Data System (ADS)

    Kathriarachchi, Vindu Wathsala

    An improved method is introduced for prediction of local tumor control following lung stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). A normalized background-corrected tumor maximum Standard Uptake Value (SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of the maximum uptake of lung tumor (SUVmax). This method minimizes the variations associated with SUVmax and objectively demonstrates a strong correlation between the low SUVcmax (< 2.5-3.0) and local control of post lung SBRT. The false positive rates of both SUVmax and SUVcmax increase with inclusion of early (<6 months) PET scans, therefore such inclusion is not recommended for assessing local tumor control of post lung SBRT.

  7. Radionuclide impurities in [¹⁸F]F⁻ and [¹⁸F]FDG for positron emission tomography.

    PubMed

    Köhler, M; Degering, D; Zessin, J; Füchtner, F; Konheiser, J

    2013-11-01

    The paper describes radionuclide impurities (γ-emitters and (3)H) in proton irradiated (18)O enriched water from an Nb target vessel with Nb entrance window, their distribution in different synthesis steps and finally in the PET radiopharmaceuticals [(18)F]Fluoride and [(18)F]FDG. PMID:23608142

  8. PET with F-18 fluorodeoxyglucose measures of local brain activity and memory in schizophrenia and in depression

    SciTech Connect

    Riege, W.H.; Metter, E.J.; Kuhl, D.E.; Phelps, M.E.; Kling, A.

    1984-01-01

    Positron emission tomography with (F-18) fluorodeoxyglucose (FDG) scan has provided non-invasive measures of regional cerebral glucose utilization which are directly related with levels of functional activity in regions of the brain. The FDG technique was applied to the study of brain activity thought to be impaired in 6 chronic schizophrenics (SCH) and 6 depressed (D) patients in comparison with 6 healthy age-matched controls (C). Local cerebral metabolic rates of glucose utilization LCMRglc were determined for 8 regions in both left and right hemispheres and were expressed in reference to a person's mean CMRglc. Multivariate comparisons of the 16 measures showed no significant differences between the 3 groups; follow-up step-down analyses and t-tests failed to specify any regional or global LCMRglc reliable to separate patients from controls. They also did not differ in any of 18 multidimensional tests of memory and decision, except for lower delayed verbal recall in D patients. When both SCH and D were classified into those with CT large and those with CT small ventricles, there were no multivariate differences. Only partial LCMRglc separated large from small ventricle patients (F(1,7) = 6.12, p<0.042), but finding no multivariate significance makes this result questionable. The ventricular grouping of SCH alone may reveal a marginal difference in global CMRglc t(4) = 2.58, p<0.06, given a larger patient sample. In contrast to recent reports, indices to brain activity in schizophrenic and depressed patients do not seem to be abnormal.

  9. Role of dual time fluorodeoxyglucose (FDG) positron emission tomography-computed tomography in identifying co-existing inflammatory and malignant disease: Who holds it (FDG) longer?

    PubMed Central

    Nair, Anirudh V.; Sandya, C. J.; Shagos, G.S.; Anirudh, Soumya; Rajamma, Bindhu Mangalath; Ramachandran, P. V.; Moorthy, Srikanth

    2015-01-01

    18-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) is an integral part of imaging in the follow-up of head and neck malignancies. Very often distinguishing inflammatory/infective from malignant recurrence cannot be made confidently with standard uptake value (SUV) alone, as inflammatory lesions have shown to have a very high SUV, and in some cases both can co-exist. In such doubtful cases, dual time PET-CT (3–5 h delayed) is of paramount importance in confidently differentiating inflammatory/infective from a malignant cause. PMID:25829732

  10. [Utility of positron emission tomography with 18F-FDG in a case of juvenile recurrent respiratory papillomatosis].

    PubMed

    Navales, I; Paredes, P; Cols, M; Perissinotti, A; Vancells, M; Pons, F

    2013-01-01

    Juvenile recurrent respiratory papillomatosis (JRRP) is an infectious disease caused by the growth of papillomas in the airway. Up to 4% of these cases degenerate into squamous cell carcinoma. We present the case of a 17-year-old female patient with JRRP in which the utility of (18)F-FDG-PET/CT in the characterization of suspicious papillomatous lesions of malignancy is evaluated. Morphometabolic techniques, CT scan and PET/CT scans were suggestive of malignancy. However, this was not confirmed in the histopathological analysis after its resection. The (18)F-FDG-PET/CT does not seem to be a useful tool for early detection of malignancy in JRRP. However, it does increase the diagnostic accuracy of the biopsy as it identifies the most active lesions and, therefore, those most likely to be malignant. PMID:23491504

  11. 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.

  12. 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.

  13. Test-retest studies of glucose metabolic rate with F-18-deoxyglucose

    SciTech Connect

    Brooks, R.A.; Di Chiro, G.; Zukerberg, B.; Bairamian, D.; Larson, S.

    1985-05-01

    In studies using F-18-deoxyglucose (FDG), one often wants to compare metabolic rates following stimulation (drug or motor-sensory) with the baseline values. However because of repeatability problems, with baseline variations of 25% in the same individual being not uncommon, the global effect of the stimulation may be difficult to see. One approach to this problem is to perform the two studies close together on the same day. With the 110 minute half-life of F-18, this means that one must take into account the residual activity from the first phase when calculating metabolic rates for the second phase. The authors performed test-retest baseline studies on three subjects, with a one hour interval between injections. To help reduce the effect of residual activity, they gave only 2 mCi in the first injection in two cases, and only 1 mCi in the other case, out of a total injected dose of 5 mCi. The use of only 1 mCi is possible because of the high sensitivity of the Neuro-PET scanner that was used for these studies. A correction for residual activity was included in the phase 2 calculation, which takes into account both the washout of free FDG from the tissue, and the dephosphorylation of trapped FDG. The authors found agreement of about 5% between the phases, for comparable areas of the brain. Better results may be achieved by increasing the time interval between studies.

  14. 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.

  15. 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.

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

    SciTech Connect

    Kidd, Elizabeth A.; Thomas, Maria; Siegel, Barry A.; Dehdashti, Farrokh; Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri ; Grigsby, Perry W.; Alvin J. Siteman Cancer Center, St. Louis, Missouri; Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri; Division of Gynecologic Oncology, Washington University School of Medicine, St. Louis, Missouri

    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

  17. 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

  18. 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.

  19. Tumor Response and Survival Predicted by Post-Therapy FDG-PET/CT in Anal Cancer

    SciTech Connect

    Schwarz, Julie K.; Siegel, Barry A.; Dehdashti, Farrokh; Myerson, Robert J.; Fleshman, James W.; Grigsby, Perry W.

    2008-05-01

    Purpose: To evaluate the response to therapy for anal carcinoma using post-therapy imaging with positron emission tomography (PET)/computed tomography and F-18 fluorodeoxyglucose (FDG) and to compare the metabolic response with patient outcome. Patients and Methods: This was a prospective cohort study of 53 consecutive patients with anal cancer. All patients underwent pre- and post-treatment whole-body FDG-PET/computed tomography. Patients had been treated with external beam radiotherapy and concurrent chemotherapy. Whole-body FDG-PET was performed 0.9-5.4 months (mean, 2.1) after therapy completion. Results: The post-therapy PET scan did not show any abnormal FDG uptake (complete metabolic response) in 44 patients. Persistent abnormal FDG uptake (partial metabolic response) was found in the anal tumor in 9 patients. The 2-year cause-specific survival rate was 94% for patients with a complete vs. 39% for patients with a partial metabolic response in the anal tumor (p = 0.0008). The 2-year progression-free survival rate was 95% for patients with a complete vs. 22% for patients with a partial metabolic response in the anal tumor (p < 0.0001). A Cox proportional hazards model of survival outcome indicated that a complete metabolic response was the most significant predictor of progression-free survival in our patient population (p = 0.0003). Conclusions: A partial metabolic response in the anal tumor as determined by post-therapy FDG-PET is predictive of significantly decreased progression-free and cause-specific survival after chemoradiotherapy for anal cancer.

  20. Fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography scan contributes to the diagnosis and management of brucellar spondylodiskitis

    PubMed Central

    2013-01-01

    Background Limited data suggest that fluorine-18 fluoro-2-deoxy-D-glucose (F-18 FDG) positron emission tomography combined with computed tomography (PET/CT) scan may be useful for diagnosing infections of the spine. Brucellar spondylodiskitis might be devastating and current imaging techniques lack sensitivity and specificity. The aim of this prospective study was to determine the role of F-18 FDG PET/CT scan in the diagnosis of brucellar spondylodiskitis and in monitoring the efficacy of its treatment. Methods Ten consecutive patients with brucellar spondylitis were prospectively evaluated with PET/CT. Baseline evaluation included also magnetic resonance imaging (MRI) of the affected spine, indices of inflammation, the slide agglutination test (SAT), and the standard hematology and biochemistry. All cases were treated with suitable antibiotics until resolution or significant improvement of clinical and radiological (MRI) findings. Upon completion of treatment, they were re-evaluated with follow-up PET/CT scan. The maximum standardized uptake values (SUV) were measured and compared with SAT. Results In all patients there was an increased F-18 FDG activity in the infected spine region detected by the initial MRI. F-18 FDG PET/CT provided additional information, compared to MRI, in 4 (40%) patients. More specifically it revealed additional spine lesions (in 3 patients), lymphadenitis, arthritis, organomegaly, as well as new paravertebral soft tissue involvement and epidural masses. This additional information had an impact on the duration of treatment in these patients. At the end of treatment all patients had a complete clinical response; 5 patients had positive serology, 6 patients had residual MRI findings, while 9 had a positive PET/CT but with significantly decreased FDG uptake compared to baseline (median 2.6, range 1.4 – 4.4 vs. median 5.5, range 2.8 – 9.4, p = 0.005). During the follow up period (median 12.5 months) no relapses have been observed

  1. Performance evaluation of principal component analysis in dynamic FDG-PET studies of recurrent colorectal cancer.

    PubMed

    Thireou, Trias; Strauss, Ludwig G; Dimitrakopoulou-Strauss, Antonia; Kontaxakis, George; Pavlopoulos, Sotiris; Santos, Andres

    2003-01-01

    Performance evaluation of principal component analysis (PCA) of dynamic F-18-FDG-PET studies of patients with recurrent colorectal cancer. Principal component images (PCI) of 17 iteratively reconstructed data sets were visually and quantitatively evaluated. The F-18-FDG compartment model parameters were estimated using polynomial regression. All structures were present in PCI1. PCI2 was correlated with the vascular component and PCI3 with the tumor. The vessel density in the tumor was estimated with a correlation coefficient equal to 0.834. PCA supports the visual interpretation of dynamic F-18-FDG-PET studies, facilitates the application of compartment modeling and is a promising quantification technique. PMID:12573889

  2. FDG-PET/CT and CT Findings of a Benign Solitary Fibrous Tumor of the Kidney; Correlation with Pathology.

    PubMed

    Nakajima, Reiko; Abe, Koichiro; Kondo, Tsunenori; Nagashima, Yoji; Kimura, Ken; Fukushima, Kenji; Momose, Mitsuru; Kondo, Chisato; Tanabe, Kazunari; Sakai, Shuji

    2015-01-01

    Herein, we report the F-18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) findings of a benign solitary fibrous tumor (SFT) of the kidney. The patient was a 63-year-old woman with a mass in the right kidney (10×9.7 cm), incidentally found on CT images. The CT scan showed a lobulated tumor arising from the hilum of the right kidney. The tumor consisted of two components with different patterns of enhancement. Most of the tumor demonstrated moderate enhancement from the corticomedullary to nephrographic phase. A small nodular component at the caudal portion of the tumor showed avid enhancement in the corticomedullary phase and rapid washout in the nephrographic phase in contrast-enhanced CT. FDG-PET/CT was performed and showed weak FDG accumulation (SUVmax=2.30 and 1.91 in the main and small caudal components). Although renal cell carcinoma was preoperatively diagnosed, histopathological examination revealed renal SFT, with no malignant potential. Therefore, when a renal tumor with contrast-medium enhancement and low FDG accumulation is demonstrated, SFT should be considered as a differential diagnosis in addition to renal cell carcinoma. PMID:27408891

  3. FDG-PET/CT and CT Findings of a Benign Solitary Fibrous Tumor of the Kidney; Correlation with Pathology

    PubMed Central

    Nakajima, Reiko; Abe, Koichiro; Kondo, Tsunenori; Nagashima, Yoji; Kimura, Ken; Fukushima, Kenji; Momose, Mitsuru; Kondo, Chisato; Tanabe, Kazunari; Sakai, Shuji

    2015-01-01

    Herein, we report the F-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) findings of a benign solitary fibrous tumor (SFT) of the kidney. The patient was a 63-year-old woman with a mass in the right kidney (10×9.7 cm), incidentally found on CT images. The CT scan showed a lobulated tumor arising from the hilum of the right kidney. The tumor consisted of two components with different patterns of enhancement. Most of the tumor demonstrated moderate enhancement from the corticomedullary to nephrographic phase. A small nodular component at the caudal portion of the tumor showed avid enhancement in the corticomedullary phase and rapid washout in the nephrographic phase in contrast-enhanced CT. FDG-PET/CT was performed and showed weak FDG accumulation (SUVmax=2.30 and 1.91 in the main and small caudal components). Although renal cell carcinoma was preoperatively diagnosed, histopathological examination revealed renal SFT, with no malignant potential. Therefore, when a renal tumor with contrast-medium enhancement and low FDG accumulation is demonstrated, SFT should be considered as a differential diagnosis in addition to renal cell carcinoma. PMID:27408891

  4. FDG-PET imaging in hematological malignancies.

    PubMed

    Valls, L; Badve, C; Avril, S; Herrmann, K; Faulhaber, P; O'Donnell, J; Avril, N

    2016-07-01

    The majority of aggressive lymphomas is characterized by an up regulated glycolytic activity, which enables the visualization by F-18 FDG-PET/CT. One-stop hybrid FDG-PET/CT combines the functional and morphologic information, outperforming both, CT and FDG-PET as separate imaging modalities. This has resulted in several recommendations using FDG-PET/CT for staging, restaging, monitoring during therapy, and assessment of treatment response as well as identification of malignant transformation. FDG-PET/CT may obviate the need for a bone marrow biopsy in patients with Hodgkin's lymphoma and diffuse large B cell lymphoma. FDG-PET/CT response assessment is recommended for FDG-avid lymphomas, whereas CT-based response evaluation remains important in lymphomas with low or variable FDG avidity. The treatment induced change in metabolic activity allows for assessment of response after completion of therapy as well as prediction of outcome early during therapy. The five-point scale Deauville Criteria allows the assessment of treatment response based on visual FDG-PET analysis. Although the use of FDG-PET/CT for prediction of therapeutic response is promising it should only be conducted in the context of clinical trials. Surveillance FDG-PET/CT after complete remission is discouraged due to the relative high number of false-positive findings, which in turn may result in further unnecessary investigations. Future directions include the use of new PET tracers such as F-18 fluorothymidine (FLT), a surrogate biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker as well as innovative digital PET/CT and PET/MRI techniques. PMID:27090170

  5. 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.

  6. 18F-FDG PET/CT Imaging of Primary Hepatic Neuroendocrine Tumor

    PubMed Central

    Mitamura, Katsuya; Yamamoto, Yuka; Tanaka, Kenichi; Sanomura, Takayuki; Murota, Makiko; Nishiyama, Yoshihiro

    2015-01-01

    Primary hepatic neuroendocrine tumors (PHNETs) are extremely rare neoplasms. Herein, we report a case of a 70- year-old man with a hepatic mass. The non-contrast computed tomography (CT) image showed a low-density mass, and dynamic CT images indicated the enhancement of the mass in the arterial phase and early washout in the late phase. F-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and fused PET/CT images showed increased uptake in the hepatic mass. Whole-body 18F-FDG PET images showed no abnormal activity except for the liver lesion. Presence of an extrahepatic tumor was also ruled out by performing upper gastrointestinal endoscopy, total colonoscopy, and chest and abdominal CT. A posterior segmentectomy was performed, and histologic examination confirmed a neuroendocrine tumor (grade 1). The patient was followed up for about 2 years after the resection, and no extrahepatic lesions were radiologically found. Therefore, the patient was diagnosed with PHNET. To the best of our knowledge, no previous case of PHNET have been detected by 18F-FDG PET imaging.

  7. (18)F-FDG PET/CT Imaging of Primary Hepatic Neuroendocrine Tumor.

    PubMed

    Mitamura, Katsuya; Yamamoto, Yuka; Tanaka, Kenichi; Sanomura, Takayuki; Murota, Makiko; Nishiyama, Yoshihiro

    2015-01-01

    Primary hepatic neuroendocrine tumors (PHNETs) are extremely rare neoplasms. Herein, we report a case of a 70- year-old man with a hepatic mass. The non-contrast computed tomography (CT) image showed a low-density mass, and dynamic CT images indicated the enhancement of the mass in the arterial phase and early washout in the late phase. F-18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and fused PET/CT images showed increased uptake in the hepatic mass. Whole-body (18)F-FDG PET images showed no abnormal activity except for the liver lesion. Presence of an extrahepatic tumor was also ruled out by performing upper gastrointestinal endoscopy, total colonoscopy, and chest and abdominal CT. A posterior segmentectomy was performed, and histologic examination confirmed a neuroendocrine tumor (grade 1). The patient was followed up for about 2 years after the resection, and no extrahepatic lesions were radiologically found. Therefore, the patient was diagnosed with PHNET. To the best of our knowledge, no previous case of PHNET have been detected by (18)F-FDG PET imaging. PMID:27408882

  8. Prognostic Value of SUVmax Measured by Pretreatment Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Patients with Ewing Sarcoma

    PubMed Central

    Hwang, Jae Pil; Lim, Ilhan; Kong, Chang-Bae; Jeon, Dae Geun; Byun, Byung Hyun; Kim, Byung Il; Choi, Chang Woon; Lim, Sang Moo

    2016-01-01

    Aim The aim of this retrospective study was to determine whether glucose metabolism assessed by using Fluorine-18 (F-18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) provides prognostic information independent of established prognostic factors in patients with Ewing sarcoma. Methods We retrospectively reviewed the medical records of 34 patients (men, 19; women, 15; mean age, 14.5 ± 9.7 years) with pathologically proven Ewing sarcoma. They had undergone F-18 FDG PET/CT as part of a pretreatment workup between September 2006 and April 2012. In this analysis, patients were classified by age, sex, initial location, size, and maximum standardized uptake value (SUVmax). The relationship between FDG uptake and survival was analyzed using the Kaplan-Meier method with the log-rank test and Cox’s proportional hazards regression model. Results The median survival time for all 34 subjects was 999 days and the median SUV by using PET/CT was 5.8 (range, 2–18.1). Patients with a SUVmax ≤ 5.8 survived significantly longer than those with a SUVmax > 5.8 (median survival time, 1265 vs. 656 days; p = 0.002). Survival was also found to be significantly related to age (p = 0.024), size (p = 0.03), and initial tumor location (p = 0.036). Multivariate analysis revealed that a higher SUVmax (p = 0.003; confidence interval [CI], 3.63–508.26; hazard ratio [HR], 42.98), older age (p = 0.023; CI, 1.34–54.80; HR, 8.59), and higher stage (p = 0.03; CI, 1.21–43.95; HR, 7.3) were associated with worse overall survival. Conclusions SUVmax measured by pretreatment F-18-FDG PET/CT can predict overall survival in patients with Ewing sarcoma. PMID:27100297

  9. Positron Lymphography: Multimodal, High-Resolution, Dynamic Mapping and Resection of Lymph Nodes After Intradermal Injection of 18F-FDG

    PubMed Central

    Thorek, Daniel L.J.; Abou, Diane S.; Beattie, Bradley J.; Bartlett, Rachel M.; Huang, Ruimin; Zanzonico, Pat B.; Grimm, Jan

    2012-01-01

    The lymphatic system plays a critical role in the maintenance of healthy tissues. Its function is an important indicator of the presence and extent of disease. In oncology, metastatic spread to local lymph nodes (LNs) is a strong predictor of poor outcome. Clinical methods for the visualization of LNs involve regional injection and tracking of 99mTc-sulfur colloid (99mTc-SC) along with absorbent dyes. Intraoperatively, these techniques suffer from the requirement of administration of multiple contrast media (99mTc-SC and isosulfan blue), unwieldy γ-probes, and a short effective surgical window for dyes. Preclinically, imaging of transport through the lymphatics is further hindered by the resolution of lymphoscintigraphy and SPECT. We investigated multimodal imaging in animal models using intradermal administration of 18F-FDG for combined diagnostic and intraoperative use. PET visualizes LNs with high sensitivity and resolution and low background. Cerenkov radiation (CR) from 18F-FDG was evaluated to optically guide surgical resection of LNs. Methods Imaging of 18F-FDG uptake used PET and sensitive luminescent imaging equipment (for CR). Dynamic PET was performed in both sexes and multiple strains (NCr Nude, C57BL/6, and Nu/Nu) of mice. Biodistribution confirmed the uptake of 18F-FDG and was compared with that of 99mTc-SC. Verification of uptake and the ability to use 18F-FDG CR to guide nodal removal were confirmed histologically. Results Intradermal injection of 18F-FDG clearly revealed lymphatic vessels and LNs by PET. Dynamic imaging revealed rapid and sustained labeling of these structures. Biodistribution of the radiotracer confirmed the active transport of radioglucose in the lymphatics to the local LNs and over time into the general circulation. 18F-FDG also enabled visualization of LNs through CR, even before surgically revealing the site, and guided LN resection. Conclusion Intradermal 18F-FDG can enhance the preclinical investigation of the lymphatics

  10. Fluorinated glucose analog, 2-fluoro-2-deoxy-D-glucose (F-18): nontoxic tracer for rapid tumor detection

    SciTech Connect

    Som, P.; Atkins, H.L.; Bandoypadhyay, D.

    1980-07-01

    Rapid uptake of F-18 FDG was observed in a variety of transplanted and spontaneous tumors in animals. The tumor uptake reached a peak by 30 min and remained relatively constant up to 60 min, with a very slow wash-out of F-18 activity from the tumor thereafter. Tumor-to-normal tissue and tumor-to-blood ratios ranged from 2.10 to 9.15 and 2.61 to 17.82, respectively, depending on the type of tumor. A scintiscan of a seminoma in a dog showed very high uptake in the viable part and lack of uptake in the necrotic mass. Toxicological studies in mice using 1000 times human tracer dose (HTD) per week for 3 weeks and in dogs using 50 times HTD per week for 3 weeks did not show any evidence of acute or chronic toxicity.

  11. Predictive value of early 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) during salvage chemotherapy in relapsing/refractory Hodgkin lymphoma (HL) treated with high-dose chemotherapy.

    PubMed

    Castagna, Luca; Bramanti, Stefania; Balzarotti, Monica; Sarina, Barbara; Todisco, Elisabetta; Anastasia, Antonella; Magagnoli, Massimo; Mazza, Rita; Nozza, Andrea; Giordano, Laura; Rodari, Marcello; Rinifilo, Eva; Chiti, Arturo; Santoro, Armando

    2009-05-01

    This retrospective study evaluated whether early 2-[fluorine-18]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) after two cycles of salvage chemotherapy (PET2) could predict survival after high-dose chemotherapy (HDC). Twenty-four Hodgkin lymphoma (HL) patients were included. PET2 was negative in 58% and positive in 42% of patients. Ninety per cent of patients (9/10) with positive PET2 relapsed after HDC while all but one patient with negative PET2 maintained a complete remission. The 2-year progression-free survival was 93% vs. 10% for patients with negative and positive PET2, respectively (P < 0.001). This study shows that interim PET can predict the outcome after high-dose chemotherapy in HL patients. PMID:19344403

  12. 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.

  13. 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.

  14. 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.

  15. Correlation of amyloid PET ligand florbetapir F 18 (18F-AV-45) binding with β-amyloid aggregation and neuritic plaque deposition in postmortem brain tissue

    PubMed Central

    Choi, Seok Rye; Schneider, Julie A.; Bennett, David A.; Beach, Thomas G.; Bedell, Barry J.; Zehntner, Simone P.; Krautkramer, Michael; Kung, Hank F.; Skovronsky, Daniel M.; Hefti, Franz; Clark, Christopher M.

    2011-01-01

    Background Florbetapir F 18 (18F-AV-45) is a positron emission tomography (PET) imaging ligand for the detection of amyloid aggregation associated with Alzheimer’s disease. Earlier data showed that florbetapir F 18 binds with high affinity to β-amyloid plaques in human brain homogenates (Kd = 3.7 nM) and has favorable imaging pharmacokinetic properties, including rapid brain penetration and washout. The present study used human autopsy brain tissue to evaluate the correlation between in vitro florbetapir F 18 binding and β-amyloid density measured by established neuropathological methods. Methods The localization and density of florbetapir F 18 binding in frozen and formalin-fixed paraffin-embedded sections of postmortem brain tissue from 40 subjects with a varying degree of neurodegenerative pathology was assessed by standard florbetapir F 18 autoradiography and correlated with the localization and density of β-amyloid identified by silver staining, thioflavin S staining, and immunohistochemistry. Results There were strong quantitative correlations between florbetapir F 18 tissue binding and both β-amyloid plaques identified by light microscopy (sliver staining and thioflavin S fluorescence) and by immunohistochemical measurements of β-amyloid using three antibodies recognizing different epitopes of the β-amyloid peptide (Aβ). Florbetapir F 18 did not bind to neurofibrillary tangles. Conclusion Florbetapir F 18 selectively binds β-amyloid in human brain tissue. The binding intensity was quantitatively correlated with the density of β-amyloid plaques identified by standard neuropathological techniques and correlated with the density of Aβ measured by immunohistochemistry. Since β-amyloid plaques are a defining neuropathological feature for Alzheimer’s disease, these results support the use of florbetapir F 18 as an amyloid PET ligand to identify the presence of AD pathology in patients with signs and symptoms of progressive late-life cognitive

  16. [18F]FDG Positron Emission Tomography within Two Weeks of Starting Erlotinib Therapy Can Predict Response in Non-Small Cell Lung Cancer Patients

    PubMed Central

    Hachemi, Mammar; Couturier, Olivier; Vervueren, Laurent; Fosse, Pacôme; Lacœuille, Franck; Urban, Thierry; Hureaux, José

    2014-01-01

    Purpose The aim of this prospective study was to evaluate whether [18F]FDG-PET/CT, performed within two weeks of starting erlotinib therapy can predict tumor response defined by RECIST 1.1 criteria after 8 weeks of treatment in patients with inoperable (stage IIIA to IV) non-small cell lung cancer patients. Patients and Methods Three [18F]FDG-PET/CT scans were acquired in 12 patients before (5±4 days) and after 9±3 days (early PET) and 60±6 days (late PET) of erlotinib therapy. Conventional evaluation, including at least chest CT (baseline versus after 8 weeks of treatment), was performed according to RECIST 1.1 criteria. Change in [18F]FDG uptake was compared with conventional response, progression-free survival (PFS), and overall survival (OS). Results By using ROC analysis, the Area Under the Curve for prediction of metabolic non-progressive disease (mNP) by early PET was 0.86 (95% CI, 0.62 to 1.1; P = 0.04) at a cut-off of 21.6% reduction in maximum Standardized Uptake Value (SUVmax). This correctly classified 11/12 patients (7 with true progressive disease; 4 with true non-progressive disease; 1 with false progressive disease). Non-progressive disease after 8 weeks of treatment according to RECIST 1.1 criteria was significantly more frequent in patients classified mNP (P = 0.01, Fisher's exact test). mNP patients showed prolonged PFS (HR = 0.27; 95% CI, 0.04 to 0.59; P<0.01) and OS (HR = 0.34; 95% CI, 0.06 to 0.84; P = 0.03). Late PET analysis provided concordant results. Conclusion Morphologic response, PFS and OS survival in non-small cell lung cancer patients can be predicted by [18F]FDG-PET/CT scan within 2 weeks after starting erlotinib therapy. PMID:24505298

  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

    ... Product List'' section of the Orange Book. In previous instances (see, e.g., 72 FR 9763, March 5, 2007; 61 FR 25497, May 21, 1996), the Agency has determined that, for purposes of Sec. Sec. 314.161 and 314... HUMAN SERVICES Food and Drug Administration Determination That SODIUM FLUORIDE F 18 (Sodium Fluoride...

  18. Positron Emission Tomography and Magnetic Resonance Imaging of the Brain in Fabry Disease: A Nationwide, Long-Time, Prospective Follow-Up

    PubMed Central

    Korsholm, Kirsten; Feldt-Rasmussen, Ulla; Granqvist, Henrik; Højgaard, Liselotte; Bollinger, Birgit; Rasmussen, Aase K.; Law, Ian

    2015-01-01

    Background Fabry disease is a rare metabolic glycosphingolipid storage disease caused by deficiency of the lysosomal enzyme α-galactosidase A—leading to cellular accumulation of globotriasylceramide in different organs, vessels, tissues, and nerves. The disease is associated with an increased risk of cerebrovascular disease at a young age in addition to heart and kidney failure. Objective The objective of this study was to assess brain function and structure in the Danish cohort of patients with Fabry disease in a prospective way using 18-fluoro-deoxyglucose (F-18 FDG) positron emission tomography (PET) and magnetic resonance imaging (MRI). Patients Forty patients with Fabry disease (14 males, 26 females, age at inclusion: 10–66 years, median: 39 years) underwent a brain F-18-FDG-PET-scan at inclusion, and 31 patients were followed with FDG-PET biannually for up to seven years. All patients (except one) had a brain MRI-scan at inclusion, and 34 patients were followed with MRI biannually for up to nine years. Image Analysis The FDG-PET-images were inspected visually and analysed using a quantitative 3-dimensional stereotactic surface projection analysis (Neurostat). MRI images were also inspected visually and severity of white matter lesions (WMLs) was graded using a visual rating scale. Results In 28 patients brain-FDG-PET was normal; in 23 of these 28 patients brain MRI was normal—of the remaining five patients in this group, four patients had WMLs and one patient never had an MRI-scan. In 10 patients hypometabolic areas were observed on brain-FDG-PET; all of these patients had cerebral infarcts/hemorrhages visualized on MRI corresponding to the main hypometabolic areas. In two patients brain-FDG-PET was ambiguous, while MRI was normal in one and abnormal in the other. Conclusion Our data indicated that, in patients with Fabry disease, MRI is the preferable clinical modality—if applicable—when monitoring cerebral status, as no additional major brain

  19. 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.

  20. Numerical investigation of tail buffet on F-18 aircraft

    NASA Technical Reports Server (NTRS)

    Rizk, Yehia M.; Guruswamy, Guru P.; Gee, Ken

    1992-01-01

    Numerical investigation of vortex induced tail buffet is conducted on the F-18 aircraft at high angles of attack. The Reynolds-averaged Navier-Stokes equations are integrated using a time-accurate, implicit procedure. A generalized overset zonal grid scheme is used to decompose the computational space around the complete aircraft with faired-over inlet. A weak coupling between the aerodynamics and structures is assumed to compute the structural oscillation of the flexible vertical tail. Time-accurate computations of the turbulent flow around the F-18 aircraft at 30 degrees angle of attack show the surface and off-surface flowfield details, including the unsteadiness created by the vortex burst and its interaction with the vertical twin tail which causes the tail buffet. The effect of installing a LEX fence on modifying the vortex structure upstream of the tail is also examined.

  1. Prediction of Central Nervous System Relapse of Diffuse Large B-Cell Lymphoma Using Pretherapeutic [18F]2-Fluoro-2-Deoxyglucose (FDG) Positron Emission Tomography/Computed Tomography

    PubMed Central

    Song, Yoo Sung; Lee, Won Woo; Lee, Jong Seok; Kim, Sang Eun

    2015-01-01

    Abstract Central nervous system (CNS) relapse of diffuse large B-cell lymphoma (DLBCL) is a rare complication, but has a poor prognosis with unknown pathophysiology. Recent trials of CNS prophylaxis have shown to be ineffective, despite patient's selection using several known clinical risk factors. In this study, the authors evaluated the value of pretreatment [18F]2-Fluoro-2-deoxyglucose positron emission tomography in predicting CNS relapse in DLBCL patients. The authors analyzed 180 pathologically confirmed DLBCL patients, retrospectively. Patients underwent [18F]2-Fluoro-2-deoxyglucose positron emission tomography/computed tomography before first line rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone therapy. Clinical characteristics were evaluated and total lesion glycolysis (TLG) with a threshold margin of 50% was calculated. Among age, sex, Ann Arbor stage, International Prognostic Index, revised International Prognostic Index, high serum lactate dehydrogenase level, presence of B symptoms, bulky disease (≥10 cm), extranodal lesion involvement, bone marrow involvement, high metabolic tumor volume ( >450 mL), and high TLG50 (>2000), the high TLG50 was the only significant prognostic factor for predicting CNS relapse in a multivariate analysis (P = 0.04). Kaplan–Meir survival analysis between high TLG50 (>2000) and low TLG50 (≤2000) groups revealed significantly different mean progression free survival (PFS) of 1317.2 ± 134.3 days and 1968.6 ± 18.3 days, respectively (P < 0.001). High TLG50 on [18F]2-Fluoro-2-deoxyglucose positron emission tomography/computed tomography is the most significant predictor of CNS relapse in un-treated DLBCL patients. PMID:26554808

  2. 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

  3. Posttransplant Lymphoproliferative Disorder of the Thorax: CT and FDG-PET Features in a Single Tertiary Referral Center.

    PubMed

    Yoon, Ga Young; Kim, Mi Young; Huh, Joo Rryung; Jo, Kyung-Wook; Shim, Tae Sun

    2015-08-01

    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

  4. Rolling flow wind tunnel tests of F-18 aircraft

    NASA Technical Reports Server (NTRS)

    Lutze, F. H.

    1980-01-01

    The lateral directional characteristics of an F-18 aircraft was investigated. Aerodynamic derivatives associated with pure roll rate, or the 'p' derivatives were obtained. The model is described and the procedures used to obtain and correct the data, and a graphical presentation of the results are presented. These results include graphs of the lateral directional static stability derivatives versus angle of attack, and the lateral directional force and moment coefficients versus nondimensional roll rate. Results are presented for several configurations including complete, complete without vertical tails, complete without horizontal tails, fuselage wing and fuselage alone. Each of these configuations was tested with and without wing leading edge extensions. The basic control surfaces were deflected and the results were investigated.

  5. 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.

  6. 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.

  7. Curved flow wind tunnnel test of F-18 aircraft

    NASA Technical Reports Server (NTRS)

    Lutze, F. H.

    1980-01-01

    The curved flow capability of a stability wind tunnel was used to investigate the lateral directional characteristics of an F-18 aircraft. The model is described and the procedures used to obtain and correct the data and a graphical presentation of the results are presented. The results include graphs of lateral directional derivatives versus sideslip or static plots, the lateral directional static stability derivatives versus angle of attack, and finally the lateral directional derivatives versus nondimensional yaw rate for different angles of attack and sideslip. Results are presented for several configurations including complete, complete without vertical tails, complete without horizontal tails, fuselage wing and fuselage alone. Each of these were tested with and without wing leading edge extensions.

  8. Evaluation of focal thyroid lesions incidentally detected in fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography images.

    PubMed

    Yaylali, O; Kirac, F S; Yuksel, D; Marangoz, E

    2014-01-01

    Background and Purpose: Increased uptake in the thyroid gland (TG) is often identified as an incidental finding on the whole body fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) in non-thyroid cancer patients. Currently, there is no consensus on the appropriate approach for the management of these cases. Thyroid ultrasound, scintigraphy and fine-needle aspiration biopsy (FNAB) are suggested to exclude malignant thyroid lesions. Our aim is to determine the importance of increased F-18-FDG uptake in the TG on positron emission tomography/computed tomography (PET/CT) scans in patients who are being screened for various forms of non-thyroid cancer. Materials and Methods: We evaluated 2000 cases undergoing whole body PET/CT scanning between April 2011 and October 2012. The age, sex, type of primary cancer, maximum standardized uptake value (SUV max ), size of the thyroid nodules and cervical lymph nodes (CLNs) on 18 F-FDG PET/CT images and if available, the biopsy results were evaluated. Results: In total, 57 patients (23 men, 34 women, mean age ± standard deviation (SD), 60.89 ± 14 years) showed an increased fluorine-18-fluorodeoxyglucose ( 18 F-FDG) uptake by the TG (average SUV max : 4.07 ± 3.7). The CLNs were detected in 19/57 patients (33%). Only 20 cases (35%) received FNAB. The final histopathological diagnosis was papillary thyroid carcinoma in seven patients (mean SUV max ± SD: 6.0 ± 5.43) and benign thyroid disease in seven patients (mean SUV max ± SD: 2.36 ± 0.63). The FNAB results were undetermined for six patients. Conclusion: Focal high 18 F-FDG uptake in the TG may be associated with an increased risk of malignancy, but the clinical significance is unclear. More data are needed to elucidate the role of the SUV in the differentiation of benign and malign thyroid lesions. If a focal increase in 18 F-FDG uptake in the TG on PET/CT is present, a prompt histopathological evaluation should be suggested

  9. Evaluation and optimization of occupational eye lens dosimetry during positron emission tomography (PET) procedures.

    PubMed

    Guiu-Souto, Jacobo; Sánchez-García, Manuel; Vázquez-Vázquez, Rubén; Otero, Carlos; Luna, Victor; Mosquera, Javier; Busto, Ramón Lobato; Aguiar, Pablo; Ruibal, Álvaro; Pardo-Montero, Juan; Pombar-Cameán, Miguel

    2016-06-01

    The last recommendations of the International Commission on Radiological Protection for eye lens dose suggest an important reduction on the radiation limits associated with early and late tissue reactions. The aim of this work is to quantify and optimize the eye lens dose associated to nurse staff during positron emission tomography (PET) procedures. PET is one of the most important diagnostic methods of oncological and neurological cancer disease involving an important number of workers exposed to the high energy isotope F-18. We characterize the relevant stages as preparation and administration of monodose syringes in terms of occupational dose. A direct reading silicon dosimeter was used to measure the lens dose to staff. The highest dose of radiation was observed during preparation of the fluorodesoxyglucose (FDG) syringes. By optimizing a suitable vials' distribution of FDG we find an important reduction in occupational doses. Extrapolation of our data to other clinical scenarios indicates that, depending on the work load and/or syringes activity, safety limits of the dose might be exceeded. PMID:27182832

  10. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three- dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  11. The FDG dose uptake ratio corrected for blood radioactivity (cDUR) is a more robust index of glucose metabolic rate

    SciTech Connect

    Hunter, G.J.; Hamberg, L.M.; Alpert, N.M.

    1994-05-01

    The dose uptake ratio (DUR) is a widely used index of F-18 fluorodeoxyglucose (FDG) metabolism in a variety of tumors. However, the reliability of this parameter depends on the time of measurement relative to the plateau of FDG uptake, the plasma glucose concentration and the rate of FDG removal from the circulation. These effects are of particular importance when DUR`s are compared in pre and post treatment studies.

  12. Metabolomics of Breast Cancer Using High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy: Correlations with 18F-FDG Positron Emission Tomography-Computed Tomography, Dynamic Contrast-Enhanced and Diffusion-Weighted Imaging MRI

    PubMed Central

    Yoon, Haesung; Yoon, Dahye; Yun, Mijin; Choi, Ji Soo; Park, Vivian Youngjean; Kim, Eun-Kyung; Jeong, Joon; Koo, Ja Seung; Yoon, Jung Hyun; Moon, Hee Jung; Kim, Suhkmann; Kim, Min Jung

    2016-01-01

    Purpose Our goal in this study was to find correlations between breast cancer metabolites and conventional quantitative imaging parameters using high-resolution magic angle spinning (HR-MAS) magnetic resonance spectroscopy (MRS) and to find breast cancer subgroups that show high correlations between metabolites and imaging parameters. Materials and methods Between August 2010 and December 2013, we included 53 female patients (mean age 49.6 years; age range 32–75 years) with a total of 53 breast lesions assessed by the Breast Imaging Reporting and Data System. They were enrolled under the following criteria: breast lesions larger than 1 cm in diameter which 1) were suspicious for malignancy on mammography or ultrasound (US), 2) were pathologically confirmed to be breast cancer with US-guided core-needle biopsy (CNB) 3) underwent 3 Tesla MRI with dynamic contrast-enhanced (DCE) and diffusion-weighted imaging (DWI) and positron emission tomography-computed tomography (PET-CT), and 4) had an attainable immunohistochemistry profile from CNB. We acquired spectral data by HR-MAS MRS with CNB specimens and expressed the data as relative metabolite concentrations. We compared the metabolites with the signal enhancement ratio (SER), maximum standardized FDG uptake value (SUV max), apparent diffusion coefficient (ADC), and histopathologic prognostic factors for correlation. We calculated Spearman correlations and performed a partial least squares-discriminant analysis (PLS-DA) to further classify patient groups into subgroups to find correlation differences between HR-MAS spectroscopic values and conventional imaging parameters. Results In a multivariate analysis, the PLS-DA models built with HR-MAS MRS metabolic profiles showed visible discrimination between high and low SER, SUV, and ADC. In luminal subtype breast cancer, compared to all cases, high SER, ADV, and SUV were more closely clustered by visual assessment. Multiple metabolites were correlated with SER and SUV in

  13. F-18-labeled 3-deoxy-3-fluoro-D-glucose for the study of regional metabolism in the brain and heart

    SciTech Connect

    Goodman, M.M.; Elmaleh, D.R.; Kearfott, K.J.; Ackerman, R.H.; Hoop, B. Jr.; Brownell, G.L.; Alpert, N.M.; Strauss, H.W.

    1981-02-01

    Glucose is the major physiological substrate of the brain and an important physiological substrate for the myocardium. (/sup 18/F)fluoro-3-deoxy-glucose(3-FDG(F-18)) was studied to determine whether it is a suitable tracer for evaluating the metabolic function of the brain and myocardium. 3-FDG(F-18) was rapidly accumulated in the mouse myocardium (10 to 12% injected dose/g) and remained constant up to 120 min. Blood, liver, and lung activities exhibited a rapid accumulation of activity (4% injected dose/g) at 1 min, followed by elimination of activity up to 30 min (2% injected dose/g), and then remaining unchanged for a period of 120 min. The arterial blood curve in the dog was fit best by three exponential components (T/sub 1/2/ = 0.52 min, 2.75 min, and 142.8 min). Transverse-section images were obtained of the dog's brain and myocardium. From sequential two-dimensional images, a clearance half-time of 26.88 min was determined for the canine brain. Radiation doses for man were calculated from tissue distribution data for mice.

  14. Proteomic Analysis of Duodenal Tissue from Escherichia coli F18-Resistant and -Susceptible Weaned Piglets

    PubMed Central

    Wu, Zhengchang; Xia, Riwei; Yin, Xuemei; Huo, Yongjiu; Zhu, Guoqiang; Wu, Shenglong; Bao, Wenbin

    2015-01-01

    Diarrhea and edema disease in weaned piglets due to infection by Escherichia coli F18 is a leading cause of economic loss in the pig industry. Resistance to E. coli F18 depends on expression of receptors on intestinal epithelial cells, and individual immunity. This study was conducted in Sutai pig E. coli F18-resistant and -susceptible full sib-pair individuals, identified on the basis of resource populations and verification of adhesion assays. The molecular mechanism underlying E. coli F18 resistance was investigated through analysis of the expression of E. coli F18 receptor associated and innate immunity proteins, using proteomics and bioinformatics techniques. Two-dimensional electrophoresis analysis revealed a total of 20 differentially expressed proteins in E. coli F18-resistant and -susceptible groups (10 upregulated and 10 downregulated). A total of 16 differentially expressed proteins were identified by MALDI TOF/TOF mass spectral analysis. According to gene ontology and pathway analysis, differentially expressed proteins were mainly involved in cell adhesion, immune response and other biologically relevant functions. Network analysis of interactions between differentially expressed proteins indicated a likelihood of their involvement in E. coli F18 infection. The expression levels of several important proteins including actin beta (ACTB), vinculin (VCL), heat stress proteins (HSPs) and transferrin (TF) in E. coli F18-resistant and -susceptible individuals were verified by Western blotting, supporting the identification of ACTB, VCL, HSPs and TF as promising candidate proteins for association with E. coli F18 susceptibility. PMID:26053838

  15. 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.

  16. (18)F-FDG PET/CT imaging in granulomatosis with polyangiitis.

    PubMed

    De Geeter, Frank; Gykiere, Pieterjan

    2016-01-01

    The paper gives an overview of the literature data on uptake of fluorine-18-fluorodeoxyglucose ((18)F-FDG) into the different tissue lesions which may occur in granulomatosis with polyangiitis (formerly called Wegener's syndrome). It discusses the cellular mechanisms of such (18)F-FDG uptake, which provide a basis for its interpretation in the context of (18)F-FDG positron emission tomography (PET) for inflammatory conditions. PMID:26929934

  17. X-31 in Flight with F-18 Chase

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A head-on view of the X-31 Enhanced Fighter Maneuverability Demonstrator aircraft (right), accompanied by a NASA F-18 chase aircraft during a research flight over the desert floor. The X-31 had a three-axis thrust-vectoring system, coupled with advanced flight controls, to allow it to maneuver tightly at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight at a 70-degree angle of attack. On April 29, 1993, the second X-31 successfully executed a rapid minimum-radius, 180-degree turn using a post-stall maneuver, flying well

  18. X-31 in Flight with F-18 Chase

    NASA Technical Reports Server (NTRS)

    1994-01-01

    One of two X-31 Enhanced Fighter Maneuverability Demonstrator aircraft (top), flown by an international test organization at NASA's Dryden Flight Research Center, Edwards, California, is seen here accompanied by a NASA F-18 chase aircraft during a research flight over the desert floor. The X-31 had a three-axis thrust-vectoring system, coupled with advanced flight controls, to allow it to maneuver tightly at very high angles of attack. The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force's Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft. This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack. Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack. During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight at a 70-degree angle of attack. On April 29, 1993, the second X-31

  19. 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

  20. Use of micro-positron emission tomography with (18)F-fallypride to measure the levels of dopamine receptor-D2 and (18)F-FDG as molecular imaging tracer in the pituitary glands and prolactinomas of Fischer-344 rats.

    PubMed

    Li, Ping; Gui, Songbai; Cao, Lei; Gao, Hua; Bai, Jiwei; Li, Chuzhong; Zhang, Yazhuo

    2016-01-01

    Dopamine receptor-D2 (DRD2) is the most important drug target in prolactinoma. The aim of this current study was to investigate the role of using micro-positron emission tomography (micro-PET) with (18)F-fallypride and (18)F-fluorodeoxyglucose ((18)F-FDG) as molecular imaging tracer in the pituitary glands and prolactinomas of Fischer-344 (F344) rats and detect the difference of the levels of DRD2 in the pituitary glands and prolactinomas of F344 rat prolactinoma models. Female F344 rat prolactinoma models were established by subcutaneous administration of 15 mg 17β-estradiol for 8 weeks. The growth of tumors was monitored by the small-animal magnetic resonance imaging and micro-PET. A series of molecular biological experiments were also performed 4 and 6 weeks after pump implantation. The micro-PET molecular imaging with (18)F-fallypride revealed a decreased expression of DRD2 in F344 rat prolactinoma models, but the micro-PET molecular imaging with (18)F-FDG presented an increased uptake in the prolactinoma compared with the pituitary gland. A decreasing trend of levels of DRD2 in F344 rat prolactinoma models was also detected by molecular biological experiments. From this, we can conclude that micro-PET with (18)F-fallypride and (18)F-FDG can be used to assess tumorigenesis of the prolactinomas in vivo and molecular imaging detection of DRD2 level in prolactinoma may be an indication of treatment effect in the animal experiment. PMID:27103832

  1. Use of micro-positron emission tomography with 18F-fallypride to measure the levels of dopamine receptor-D2 and 18F-FDG as molecular imaging tracer in the pituitary glands and prolactinomas of Fischer-344 rats

    PubMed Central

    Li, Ping; Gui, Songbai; Cao, Lei; Gao, Hua; Bai, Jiwei; Li, Chuzhong; Zhang, Yazhuo

    2016-01-01

    Dopamine receptor-D2 (DRD2) is the most important drug target in prolactinoma. The aim of this current study was to investigate the role of using micro-positron emission tomography (micro-PET) with 18F-fallypride and 18F-fluorodeoxyglucose (18F-FDG) as molecular imaging tracer in the pituitary glands and prolactinomas of Fischer-344 (F344) rats and detect the difference of the levels of DRD2 in the pituitary glands and prolactinomas of F344 rat prolactinoma models. Female F344 rat prolactinoma models were established by subcutaneous administration of 15 mg 17β-estradiol for 8 weeks. The growth of tumors was monitored by the small-animal magnetic resonance imaging and micro-PET. A series of molecular biological experiments were also performed 4 and 6 weeks after pump implantation. The micro-PET molecular imaging with 18F-fallypride revealed a decreased expression of DRD2 in F344 rat prolactinoma models, but the micro-PET molecular imaging with 18F-FDG presented an increased uptake in the prolactinoma compared with the pituitary gland. A decreasing trend of levels of DRD2 in F344 rat prolactinoma models was also detected by molecular biological experiments. From this, we can conclude that micro-PET with 18F-fallypride and 18F-FDG can be used to assess tumorigenesis of the prolactinomas in vivo and molecular imaging detection of DRD2 level in prolactinoma may be an indication of treatment effect in the animal experiment. PMID:27103832

  2. A fiber-optically coupled positron-sensitive surgical probe

    SciTech Connect

    Raylman, R.R.; Wahl, R.L.

    1994-05-01

    Positron-emitting radiopharmaceuticals such as {sup 18}F-labeled 2-deoxy-D-glucose (FDG) have considerable utility in the noninvasive imaging of cancers due to their rapid and excellent tumor-localizing properties. In addition, the relatively short range of positrons in tissue facilitates the precise delineation of FDG-avid tumors. Therefore, FDG used in conjunction with a positron-sensitive probe may be capable of guiding surgical procedures. Many of the current probe systems, however, are sensitive to the intense flux of background photons produced by positron annihilation. The authors describe the design, manufacture and initial in vitro and in vivo testing of a probe well-suited to the detection of positron-emitting isotopes in a high-photon background. The device consists of a small piece of plastic scintillator coupled by fiber-optic cable to a photomultiplier tube. Measurements of resolution and detector sensitivity were obtained. In addition, the reduction in resolution caused by the effects of various levels of background photon flux was determined. These measurements indicate that resolution is degraded minimally ({approximately}5% with a background-to-source ratio of 2:1) due to annihilation photon background. Sensitivity for positrons is good, detecting amounts of radioactivity as low as 10.2 nCi of FDG in vitro. In rats given FDG subcutaneously, lymph nodes containing as little as 11 nCi of FDG could be detected above the background activity levels present in normal surrounding tissues. A plastic scintillator probe system has been devised which may be highly suitable for intraoperative FDG-guided (or other positron or beta emitting-tracer) surgery. 29 refs., 7 figs.

  3. Value of sequential 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in prediction of the overall survival of esophageal cancer patients treated with chemoradiotherapy

    PubMed Central

    Li, Yimin; Lin, Qin; Luo, Zuoming; Zhao, Long; Zhu, Luchao; Sun, Long; Wu, Hua

    2015-01-01

    This study is to investigate the value of the metabolic parameters measured by sequential FDG PET/CT in predicting the overall survival of patients with esophageal squamous cell carcinoma (ESCC). A total of 160 patients who were newly diagnosed as ESCC patients and treated with chemoradiotherapy were included in this study. The FDG PET/CT was carried out prior to radiotherapy (PET1), when the cumulative dose of radiotherapy reached 50 Gy (PET2), at the end of radiotherapy (PET3) and 1 month after radiotherapy (PET4). The max of the standard uptake value (SUVmax) of the primary tumor, the metabolic tumor volume (MTV) and the total lesion glycolisis (TLG) prior to treatment were measured. The correlation of the measured parameters and the derived parameters of SUVmax with the overall survival was analyzed. The relatively reduced percentage of the SUVmax of PET3 and PET4 to the SUVmax of PET1 and PET2, had predictive value for the overall survival. The area under researcher operation curve (ROC) was between 0.62 and 0.73 (P < 0.01). The MTV and TLG prior to treatment might be used to predict the overall survival, and the area under ROC were both 0.69 (P < 0.001). Sequential FDG PET/CT scanning is useful to predict the overall survival of chemoradiotherapy for ESCC. The metabolic parameters and the derived parameters of FDG PET/CT have predictive values for overall survival. PMID:26379889

  4. Value of sequential 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in prediction of the overall survival of esophageal cancer patients treated with chemoradiotherapy.

    PubMed

    Li, Yimin; Lin, Qin; Luo, Zuoming; Zhao, Long; Zhu, Luchao; Sun, Long; Wu, Hua

    2015-01-01

    This study is to investigate the value of the metabolic parameters measured by sequential FDG PET/CT in predicting the overall survival of patients with esophageal squamous cell carcinoma (ESCC). A total of 160 patients who were newly diagnosed as ESCC patients and treated with chemoradiotherapy were included in this study. The FDG PET/CT was carried out prior to radiotherapy (PET1), when the cumulative dose of radiotherapy reached 50 Gy (PET2), at the end of radiotherapy (PET3) and 1 month after radiotherapy (PET4). The max of the standard uptake value (SUVmax) of the primary tumor, the metabolic tumor volume (MTV) and the total lesion glycolisis (TLG) prior to treatment were measured. The correlation of the measured parameters and the derived parameters of SUVmax with the overall survival was analyzed. The relatively reduced percentage of the SUVmax of PET3 and PET4 to the SUVmax of PET1 and PET2, had predictive value for the overall survival. The area under researcher operation curve (ROC) was between 0.62 and 0.73 (P < 0.01). The MTV and TLG prior to treatment might be used to predict the overall survival, and the area under ROC were both 0.69 (P < 0.001). Sequential FDG PET/CT scanning is useful to predict the overall survival of chemoradiotherapy for ESCC. The metabolic parameters and the derived parameters of FDG PET/CT have predictive values for overall survival. PMID:26379889

  5. Contrast-enhanced [18F] fluorodeoxyglucose-positron emission tomography-computed tomography as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin

    PubMed Central

    Jain, Avani; Srivastava, Madhur Kumar; Pawaskar, Alok Suresh; Shelley, Simon; Elangovan, Indirani; Jain, Hasmukh; Pandey, Somnath; Kalal, Shilpa; Amalachandran, Jaykanth

    2015-01-01

    Background: To evaluate the advantages of contrast enhanced F-18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-contrast enhanced CT [CECT]) when used as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin (MUO). Materials and Methods: A total of 243 patients with fine needle aspiration cytology/biopsy proven MUO were included in this prospective study. Patients who were thoroughly evaluated for primary or primary tumor was detected by any other investigation were excluded from the analysis. Totally, 163 patients with pathological diagnosis of malignancy but no apparent sites of the primary tumor were finally selected for analysis. The site of probable primary malignancy suggested by PET-CECT was confirmed by biopsy/follow-up. Results: PET-CECT suggested probable site of primary in 128/163 (78.52%) patients. In 30/35 remaining patients, primary tumor was not detected even after extensive work-up. In 5 patients, where PET-CECT was negative, primary was found on further extensive investigations or follow-up. The sensitivity, specificity, positive predictive value and negative predictive value of the study were 95.76%, 66.67%, 88.28% and 85.71% respectively. Conclusions: F-18 FDG PET-CECT aptly serves the purpose of initial imaging modality owing to high sensitivity, negative and positive predictive value. PET-CECT not only surveys the whole body for the primary malignancy but also stages the disease accurately. Use of contrast improves the diagnostic utility of modality as well as help in staging of the primary tumor. Although benefits of using PET-CECT as initial diagnostic modality are obvious from this study, there is a need for a larger study comparing conventional methods for diagnosing primary in patients with MUO versus PET-CECT. PMID:26170563

  6. 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.

  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. 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.

  9. [HPLC enantioseparation, absolute configuration determination and anti-HIV-1 activity of (±)-F18 enantiomers].

    PubMed

    Zhang, Lei-lei; Xue, Hai; Li, Li; Lu, Xiao-fan; Chen, Zhi-wei; Lu, Gang

    2015-06-01

    Racemic (±)-F18 (10-chloromethyl-11-demethyl-12-oxo-calanolide A), an analog of nature product (+)-calanolide A, is a new anti-HIV-1 nonnucleoside reverse transcript inhibitor (NNRTI). A successful enantioseparation of (±)-F18 offering (R)-F18 and (S)-F18 was achieved by a chiral stationary phase prepared HPLC. Their absolute configurations were determined by measurement of their electronic circular dichroisms combined with modem quantum-chemical calculations. Further investigation revealed that (R)-F18 and (S)-F18 shared a similar anti-HIV activities, however, (R)-F18 was more potent than (S)-F18 against wild-type virus, K101E mutation and P225H mutation pseudoviruses. PMID:26521445

  10. Positron microscopy

    SciTech Connect

    Hulett, L.D. Jr.; Xu, J.

    1995-02-01

    The negative work function property that some materials have for positrons make possible the development of positron reemission microscopy (PRM). Because of the low energies with which the positrons are emitted, some unique applications, such as the imaging of defects, can be made. The history of the concept of PRM, and its present state of development will be reviewed. The potential of positron microprobe techniques will be discussed also.

  11. Positron emission tomographic imaging of tumors using monoclonal antibodies

    SciTech Connect

    Zalutsky, M.R.

    1992-08-01

    This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.

  12. Real-time PCR for differentiation of F18 variants among enterotoxigenic and Shiga toxin-producing Escherichia coli from piglets with diarrhoea and oedema disease.

    PubMed

    Byun, Jae-Won; Jung, Byeong Yeal; Kim, Ha-Young; Fairbrother, John M; Lee, Myoung-Heon; Lee, Wan-Kyu

    2013-11-01

    One-step real-time PCR using one set of primers and four probes was developed for differentiation of F18 variants (F18 common, F18ab, F18ac, F18new variant) of enterotoxigenic (ETEC) and Shiga toxin-producing (STEC) Escherichia coli from piglets with diarrhoea and oedema disease. The limits of detection for F18common, F18ab, F18ac, and F18new variant were 10(7), 10(7), 10(5) and 10(7)colony forming units/g faeces, respectively. Of 94 Korean isolates of E. coli encoding F18, 70 were F18ac (43 STEC/ETEC, 4 STEC and 23 ETEC), 15 were F18ab (all STEC) and nine were F18new variant (1 STEC/ETEC, 7 STEC, 1 ETEC). PMID:23992871

  13. High uptake in schneiderian papillomas of the maxillary sinus on positron-emission tomography using fluorodeoxyglucose.

    PubMed

    Lin, F Y; Genden, E M; Lawson, W L; Som, P; Kostakoglu, L

    2009-02-01

    Schneiderian papillomas are benign tumors of the nasal cavity and paranasal sinuses often asymptomatic in their early stages. We report a case of a maxillary sinus oncocytic schneiderian papilloma first detected by positron-emission tomography by using fluorodeoxyglucose (FDG). Schneiderian papillomas demonstrate increased FDG uptake, similar to that of other oncocytic tumors, making it important for otolaryngologists and radiologists to realize that high uptake of FDG does not necessarily indicate a malignant lesion. PMID:18768722

  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. PMID:26970430

  15. 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.

  16. 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.

  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. Comparative Oncology: Evaluation of 2-Deoxy-2-[18F]fluoro-D-glucose (FDG) Positron Emission Tomography/Computed Tomography (PET/CT) for the Staging of Dogs with Malignant Tumors

    PubMed Central

    Beer, Ambros J.; Brühschwein, Andreas; Kreutzmann, Nina; Laberke, Silja; Wergin, Melanie C.; Meyer-Lindenberg, Andrea; Brandl, Johanna; von Thaden, Anne-Kathrin; Farrell, Eliane

    2015-01-01

    Introduction 2-Deoxy-2-[18F]fluoro-D-glucose PET/CT is a well-established imaging method for staging, restaging and therapy-control in human medicine. In veterinary medicine, this imaging method could prove to be an attractive and innovative alternative to conventional imaging in order to improve staging and restaging. The aim of this study was both to evaluate the effectiveness of this image-guided method in canine patients with spontaneously occurring cancer as well as to illustrate the dog as a well-suited animal model for comparative oncology. Methods Ten dogs with various malignant tumors were included in the study and underwent a whole body FDG PET/CT. One patient has a second PET-CT 5 months after the first study. Patients were diagnosed with histiocytic sarcoma (n = 1), malignant lymphoma (n = 2), mammary carcinoma (n = 4), sertoli cell tumor (n = 1), gastrointestinal stromal tumor (GIST) (n = 1) and lung tumor (n = 1). PET/CT data were analyzed with the help of a 5-point scale in consideration of the patients’ medical histories. Results In seven of the ten dogs, the treatment protocol and prognosis were significantly changed due to the results of FDG PET/CT. In the patients with lymphoma (n = 2) tumor extent could be defined on PET/CT because of increased FDG uptake in multiple lymph nodes. This led to the recommendation for a therapeutic polychemotherapy as a treatment. In one of the dogs with mammary carcinoma (n = 4) and in the patient with the lung tumor (n = 1), surgery was cancelled due to the discovery of multiple metastasis. Consequently no treatment was recommended. Conclusion FDG PET/CT offers additional information in canine patients with malignant disease with a potential improvement of staging and restaging. The encouraging data of this clinical study highlights the possibility to further improve innovative diagnostic and staging methods with regard to comparative oncology. In the future, performing PET/CT not only for staging but also in

  19. 18F-FDG PET in the Diagnosis and Treatment of Primary Central Nervous System Lymphoma

    PubMed Central

    Yamamoto, Yuka; Nishiyama, Yoshihiro; Tamiya, Takashi

    2013-01-01

    This paper summarizes the usefulness and limitation of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) in the diagnosis and treatment of primary central nervous system lymphoma (PCNSL). The 18F-FDG uptake in typical PCNSL is about 2.5 times higher than that in the normal gray matter, and the tumor can usually be identified visually. The 18F-FDG uptake pattern and value provide useful information for differentiating PCNSL from other enhancing malignant brain tumors especially glioblastoma (GB). The 18F-FDG uptake in typical PCNSL is usually homogenous, and the uptake value is significantly higher than that in GB. However, 18F-FDG PET often fails to show the presence of tumor in the brain as 18F-FDG uptake is faint in atypical PCNSL such as disseminated or nonenhancing lesions. 18F-FDG PET is also useful for evaluating the treatment response at a very early stage after the initial treatment. Pretreatment and posttreatment 18F-FDG uptake values may have a prognostic value in patients with PCNSL. In conclusion, 18F-FDG PET is very useful in the diagnosis of typical PCNSL and can differentiate PCNSL from other malignant brain tumors. However, the usefulness of 18F-FDG PET is limited in the diagnosis of atypical PCNSL. PMID:23844359

  20. Research flight-control system development for the F-18 high alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Pahle, Joseph W.; Powers, Bruce; Regenie, Victoria; Chacon, Vince; Degroote, Steve; Murnyak, Steven

    1991-01-01

    The F-18 high alpha research vehicle was recently modified by adding a thrust vectoring control system. A key element in the modification was the development of a research flight control system integrated with the basic F-18 flight control system. Discussed here are design requirements, system development, and research utility of the resulting configuration as an embedded system for flight research in the high angle of attack regime. Particular emphasis is given to control system modifications and control law features required for high angle of attack flight. Simulation results are used to illustrate some of the thrust vectoring control system capabilities and predicted maneuvering improvements.

  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. 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

  3. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  4. The Basic Principles of FDG-PET/CT Imaging.

    PubMed

    Basu, Sandip; Hess, Søren; Nielsen Braad, Poul-Erik; Olsen, Birgitte Brinkmann; Inglev, Signe; Høilund-Carlsen, Poul Flemming

    2014-10-01

    Positron emission tomography (PET) imaging with 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG) forms the basis of molecular imaging. FDG-PET imaging is a multidisciplinary undertaking that requires close interdisciplinary collaboration in a broad team comprising physicians, technologists, secretaries, radio-chemists, hospital physicists, molecular biologists, engineers, and cyclotron technicians. The aim of this review is to provide a brief overview of important basic issues and considerations pivotal to successful patient examinations, including basic physics, instrumentation, radiochemistry, molecular and cell biology, patient preparation, normal distribution of tracer, and potential interpretive pitfalls. PMID:26050942

  5. 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.

  6. 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.

  7. Nanobody Mediated Inhibition of Attachment of F18 Fimbriae Expressing Escherichia coli

    PubMed Central

    Moonens, Kristof; De Kerpel, Maia; Coddens, Annelies; Cox, Eric; Pardon, Els; Remaut, Han; De Greve, Henri

    2014-01-01

    Post-weaning diarrhea and edema disease caused by F18 fimbriated E. coli are important diseases in newly weaned piglets and lead to severe production losses in farming industry. Protective treatments against these infections have thus far limited efficacy. In this study we generated nanobodies directed against the lectin domain of the F18 fimbrial adhesin FedF and showed in an in vitro adherence assay that four unique nanobodies inhibit the attachment of F18 fimbriated E. coli bacteria to piglet enterocytes. Crystallization of the FedF lectin domain with the most potent inhibitory nanobodies revealed their mechanism of action. These either competed with the binding of the blood group antigen receptor on the FedF surface or induced a conformational change in which the CDR3 region of the nanobody displaces the D″-E loop adjacent to the binding site. This D″-E loop was previously shown to be required for the interaction between F18 fimbriated bacteria and blood group antigen receptors in a membrane context. This work demonstrates the feasibility of inhibiting the attachment of fimbriated pathogens by employing nanobodies directed against the adhesin domain. PMID:25502211

  8. Utility of [18F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG PET/CT) in the Initial Staging and Response Assessment of Locally Advanced Breast Cancer Patients Receiving Neoadjuvant Chemotherapy.

    PubMed

    Hulikal, Narendra; Gajjala, Sivanath Reddy; Kalawat, Teck Chand; Kottu, Radhika; Amancharla Yadagiri, Lakshmi

    2015-12-01

    In India up to 50 % of breast cancer patients still present as locally advanced breast cancer (LABC). The conventional methods of metastatic work up include physical examination, bone scan, chest & abdominal imaging, and biochemical tests. It is likely that the conventional staging underestimates the extent of initial spread and there is a need for more sophisticated staging procedure. The PET/CT can detect extra-axillary and occult distant metastases and also aid in predicting response to chemotherapy at an early point in time. To evaluate the utility of FDG PET/CT in initial staging and response assessment of patients with LABC receiving NACT. A prospective study of all biopsy confirmed female patients diagnosed with LABC receiving NACT from April 2013 to May 2014. The conventional work up included serum chemistry, CECT chest and abdomen and bone scan. A baseline whole body PET/CT was done in all patients. A repeat staging evaluation and a whole body PET/CT was done after 2/3rd cycle of NACT in non-responders and after 3/4 cycles in clinical responders. The histopathology report of the operative specimen was used to document the pathological response. The FDG PET/CT reported distant metastases in 11 of 38 patients, where as conventional imaging revealed metastases in only 6. Almost all the distant lesions detected by conventional imaging were detected with PET/CT, which showed additional sites of metastasis in 3 patients. In 2 patients, PET/CT detected osteolytic bone metastasis which were not detected by bone scan. In 5 patients PET CT detected N3 disease which were missed on conventional imaging. A total of 14 patients had second PET/CT done to assess the response to NACT and 11 patients underwent surgery. Two patients had complete pathological response. Of these 1 patient had complete metabolic and morphologic response and other had complete metabolic and partial morphologic response on second PET/CT scan. The 18 FDG PET/CT can detect more number of

  9. Flip-flop phenomenon in systemic sclerosis on fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Oksuzoglu, Kevser; Ozen, Gulsen; Inanir, Sabahat; Direskeneli, Rafi Haner

    2015-01-01

    Systemic sclerosis (SSc) is a rare autoimmune disease, which may affect multiple organ systems. Fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) can demonstrate the degree and anatomical extent of involvement in the entire body and coexisting malignancies in connective tissue diseases. We present a case of SSc with an increased 18F-FDG uptake in the cutaneous and subcutaneous tissues even higher than the neighboring skeletal muscles ("flip-flop phenomenon," that is, an increased 18F-FDG uptake in the skin but a decreased 18F-FDG uptake in the skeletal muscles). PMID:26430324

  10. Improving (18)F-Fluoro-D-Glucose-Positron Emission Tomography/Computed Tomography Imaging in Alzheimer's Disease Studies.

    PubMed

    Knešaurek, Karin

    2015-01-01

    The goal was to improve Alzheimer's 2-deoxy-2-(18)F-fluoro-D-glucose ((18)F FDG)-positron emission tomography (PET)/computed tomography (CT) imaging through application of a novel, hybrid Fourier-wavelet windowed Fourier transform (WFT) restoration technique, in order to provide earlier and more accurate clinical results. General Electric Medical Systems downward-looking sonar PET/CT 16 slice system was used to acquire studies. Patient data were acquired according the Alzheimer's disease Neuroimaging Initiative (ADNI) protocol. Here, we implemented Fourier-wavelet regularized restoration, with a Butterworth low-pass filter, order n = 6 and a cut-off frequency f = 0.35 cycles/pixel and wavelet (Daubechies, order 2) noise suppression. The original (PET-O) and restored (PET-R) ADNI subject PET images were compared using the Alzheimer's discrimination analysis by dedicated software. Forty-two PET/CT scans were used in the study. They were performed on eleven ADNI subjects at intervals of approximately 6 months. The final clinical diagnosis was used as a gold standard. For three subjects, the final clinical diagnosis was mild cognitive impairment and those 13 PET/CT studies were not included in the final comparison, as the result was considered as inconclusive. Using the reminding 29 PET/CT studies (23 AD and 6 normal), the sensitivity and specificity of the PET-O and PET-R were calculated. The sensitivity was 0.65 and 0.96 for PET-O and PET-R, respectively, and the specificity was 0.67 and 0.50 for PET-O and PET-R. The accuracy was 0.66 and 0.86 for PET-O and PET-R, respectively. The results of the study demonstrated that the accuracy of three-dimensional brain F-18 FDG PET images was significantly improved by Fourier-wavelet restoration filtering. PMID:26420987

  11. Two foci of FDG-avid secondary tumoral calcinosis incidentally noted in a patient with small-cell lung carcinoma after PET/CT

    PubMed Central

    Duryea, Dennis M.; Walker, Eric R.; Brian, Pamela L.

    2015-01-01

    This case report describes intense F-18 fluorodeoxyglucose (FDG) uptake within two foci of secondary tumoral calcinosis, incidentally noted during the workup of small-cell lung cancer. The patient had insulin-dependent diabetes mellitus and secondary hyperparathyroidism as a result of IgA nephropathy. PMID:27190558

  12. 18F-Fluorodeoxyglucose Positron Emission Tomography/Magnetic Resonance in Lymphoma

    PubMed Central

    Giraudo, Chiara; Raderer, Markus; Karanikas, Georgios; Weber, Michael; Kiesewetter, Barbara; Dolak, Werner; Simonitsch-Klupp, Ingrid; Mayerhoefer, Marius E.

    2016-01-01

    Objectives The aim of this study was to compare 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) (with and without diffusion-weighted imaging [DWI]) to 18F-FDG PET/computed tomography (CT), with regard to the assessment of nodal and extranodal involvement, in patients with Hodgkin lymphoma and non-Hodgkin lymphoma, without restriction to FDG-avid subytpes. Materials and Methods Patients with histologically proven lymphoma were enrolled in this prospective, institutional review board–approved study. After a single 18F-FDG injection, patients consecutively underwent 18F-FDG PET⁄CT and 18F-FDG PET/MR on the same day for staging or restaging. Three sets of images were analyzed separately: 18F-FDG PET/CT, 18F-FDG PET/MR without DWI, and 18F-FDG PET/MR with DWI. Region-based agreement and examination-based sensitivity and specificity were calculated for 18F-FDG PET/CT, 18F-FDG PET/MR without DWI, and 18F-FDG PET/MR DWI. Maximum and mean standardized uptake values (SUVmax, SUVmean) on 18F-FDG PET/CT and 18F-FDG PET/MR were compared and correlated with minimum and mean apparent diffusion coefficients (ADCmin, ADCmean). Results Thirty-four patients with a total of 40 examinations were included. Examination-based sensitivities for 18F-FDG PET/CT, 18F-FDG PET/MR, and 18F-FDG PET/MR DWI were 82.1%, 85.7%, and 100%, respectively; specificities were 100% for all 3 techniques; and accuracies were 87.5%, 90%, and 100%, respectively. 18F-FDG PET/CT was false negative in 5 of 40 examinations (all with mucosa-associated lymphoid tissue lymphoma), and 18F-FDG PET/MR (without DWI) was false negative in 4 of 40 examinations. Region-based percentages of agreement were 99% (κ, 0.95) between 18F-FDG PET/MR DWI and 18F-FDG PET/CT, 99.2% (κ, 0.96) between 18F-FDG PET/MR and 18F-FDG PET/CT, and 99.4% (κ, 0.97) between 18F-FDG PET/MR DWI and 18F-FDG PET/MR. There was a strong correlation between 18F-FDG PET/CT and 18F-FDG PET/MR for SUVmax (r = 0

  13. FDG-Avid Portal Vein Tumor Thrombosis from Hepatocellular Carcinoma in Contrast-Enhanced FDG PET/CT

    PubMed Central

    Nguyen, Xuan Canh; Nguyen, Dinh Song Huy; Ngo, Van Tan; Maurea, Simone

    2015-01-01

    Objective(s): In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT), complicating hepatocellular carcinoma (HCC) in contrast-enhanced FDG PET/CT scan. Methods: In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), which is a combination of dynamic liver CT scan, multiphase imaging, and whole-body PET scan. PET and CT DICOM images of patients were imported into the PET/CT imaging system for the re-analysis of contrast enhancement and FDG uptake in thrombus, the diameter of the involved portal vein, and characteristics of liver tumors and metastasis. Results: Two patients with previously untreated HCC and 7 cases with previously treated HCC had FDG-avid PVTT in contrast-enhanced FDG PET/CT scan. During the arterial phase of CT scan, portal vein thrombus showed contrast enhancement in 8 out of 9 patients (88.9%). PET scan showed an increased linear FDG uptake along the thrombosed portal vein in all patients. The mean greatest diameter of thrombosed portal veins was 1.8 ± 0.2 cm, which was significantly greater than that observed in normal portal veins (P<0.001). FDG uptake level in portal vein thrombus was significantly higher than that of blood pool in the reference normal portal vein (P=0.001). PVTT was caused by the direct extension of liver tumors. All patients had visible FDG-avid liver tumors in contrast-enhanced images. Five out of 9 patients (55.6%) had no extrahepatic metastasis, 3 cases (33.3%) had metastasis of regional lymph nodes, and 1 case (11.1%) presented with distant metastasis. The median estimated survival time of patients was 5 months. Conclusion: The intraluminal filling defect consistent with thrombous within the portal vein, expansion of the involved portal vein, contrast enhancement, and linear increased FDG uptake of the thrombus extended from liver tumor are findings of FDG

  14. Guidance for reading FDG PET scans in dementia patients.

    PubMed

    Herholz, K

    2014-12-01

    18F-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) is a powerful method for detection of disease-related impairment of cerebral glucose metabolism in neurodegenerative diseases. It is of particular interest for early and differential diagnosis of dementia. Reading FDG PET scans requires training to recognise deviations from normal functional brain anatomy and its variations. This paper provides guidance for displaying FDG PET brain scans in a reproducible manner that allows reliable recognition of characteristic disease-related metabolic changes. It also describes typical findings in Alzheimer's disease, Frontotemporal Dementia and Dementia with Lewy Bodies and possible confounding factors, such as vascular changes and brain atrophy. It provides a brief overview on findings in other neurodegenerative diseases and addresses the potential and limitations of software packages for comparison of individual scans with reference data. PMID:25391316

  15. F-18 simulation with Simulation Group Lead Martha Evans at the controls

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Simulation Group Leader Martha Evans is seen here at the controls of the F-18 aircraft simulator at NASA's Dryden Flight Research Center, Edwards, California. Simulators offer a safe and economical alternative to actual flights to gather data, as well as being excellent facilities for pilot practice and training. 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.

  16. 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.

  17. 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.

  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. Microarray analysis of differential gene expression in sensitive and resistant pig to Escherichia coli F18.

    PubMed

    Bao, W B; Ye, L; Pan, Z Y; Zhu, J; Du, Z D; Zhu, G Q; Huang, X G; Wu, S L

    2012-10-01

    In this study, Agilent two-colour microarray-based gene expression profiling was used to detect differential gene expression in duodenal tissues collected from eight full-sib pairs of Sutai pigs differing in adhesion phenotype (sensitivity and resistance to Escherichia coli F18). Using a two-fold change minimum threshold, we found 18 genes that were differentially expressed (10 up-regulated and eight down-regulated) between the sensitive and resistant animal groups. Our gene ontology analysis revealed that these differentially expressed genes are involved in a variety of biological processes, including immune responses, extracellular modification (e.g. glycosylation), cell adhesion and signal transduction, all of which are related to the anabolic metabolism of glycolipids, as well as to inflammation- and immune-related pathways. Based on the genes identified in the screen and the pathway analysis results, real-time PCR was used to test the involvement of ST3GAL1 and A genes (of glycolipid-related pathways), SLA-1 and SLA-3 genes (of inflammation- and immune-related pathways), as well as the differential genes FUT1, TAP1 and SLA-DQA. Subsequently, real-time PCR was performed to validate seven differentially expressed genes screened out by the microarray approach, and sufficient consistency was observed between the two methods. The results support the conclusion that these genes are related to the E. coli F18 receptor and susceptibility to E. coli F18. PMID:22497274

  20. 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

  1. 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.

  2. Realizing the potential of positron emission tomography with 18F-fluorodeoxyglucose to improve the treatment of Alzheimer's disease.

    PubMed

    Foster, Norman L; Wang, Angela Y; Tasdizen, Tolga; Fletcher, P Thomas; Hoffman, John M; Koeppe, Robert A

    2008-01-01

    Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG-PET) thus far rarely has been used to advance the development of new treatments for Alzheimer's disease (AD). Now that FDG-PET with standard acquisition protocols for dementia is widely available, change in cerebral glucose metabolism is a feasible outcome variable for clinical drug trials. Individual analysis of FDG-PET results also might prove valuable. FDG-PET can detect metabolic changes very early in the course of AD and identify subjects for earlier treatment. FDG-PET reliably distinguishes AD from frontotemporal dementia so that only those most likely to benefit are enrolled in trials. Finally, objectively identifying phenotypic variations of AD with FDG-PET might have pathogenic and prognostic implications that can be used for personalized treatment approaches. The judicious use of FDG-PET is needed to accelerate the evaluation of promising new drugs and more rationally target treatments for dementing diseases. PMID:18631997

  3. 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

  4. Positron autoradiography for intravascular imaging: feasibility evaluation

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.; Xu, Tong; Ducote, Justin L.; Easwaramoorthy, Balasubramaniam; Mukherjee, Jogeshwar; Molloi, Sabee

    2006-02-01

    Approximately 70% of acute coronary artery disease is caused by unstable (vulnerable) plaques with an inflammation of the overlying cap and high lipid content. A rupturing of the inflamed cap of the plaque results in propagation of the thrombus into the lumen, blockage of the artery and acute ischaemic syndrome or sudden death. Morphological imaging such as angiography or intravascular ultrasound cannot determine inflammation status of the plaque. A radiotracer such as 18F-FDG is accumulated in vulnerable plaques due to higher metabolic activity of the inflamed cap and could be used to detect a vulnerable plaque. However, positron emission tomography (PET) cannot detect the FDG-labelled plaques because of respiratory and heart motions, small size and low activity of the plaques. Plaques can be detected using a miniature particle (positron) detector inserted into the artery. In this work, a new detector concept is investigated for intravascular imaging of the plaques. The detector consists of a storage phosphor tip bound to the end of an intravascular catheter. It can be inserted into an artery, absorb the 18F-FDG positrons from the plaques, withdrawn from the artery and read out. Length and diameter of the storage phosphor tip can be matched to the length and the diameter of the artery. Monte Carlo simulations and experimental evaluations of coronary plaque imaging with the proposed detector were performed. It was shown that the sensitivity of the storage phosphor detector to the positrons of 18F-FDG is sufficient to detect coronary plaques with 1 mm and 2 mm sizes and 590 Bq and 1180 Bq activities in the arteries with 2 mm and 3 mm diameters, respectively. An experimental study was performed using plastic tubes with 2 mm diameter filled with an FDG solution, which simulates blood. FDG spots simulating plaques were placed over the surface of the tube. A phosphor tip was inserted into the tube and imaged the plaques. Exposure time was 1 min in all simulations and

  5. 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

  6. Methods and applications of positron-based medical imaging

    NASA Astrophysics Data System (ADS)

    Herzog, H.

    2007-02-01

    Positron emission tomography (PET) is a diagnostic imaging method to examine metabolic functions and their disorders. Dedicated ring systems of scintillation detectors measure the 511 keV γ-radiation produced in the course of the positron emission from radiolabelled metabolically active molecules. A great number of radiopharmaceuticals labelled with 11C, 13N, 15O, or 18F positron emitters have been applied both for research and clinical purposes in neurology, cardiology and oncology. The recent success of PET with rapidly increasing installations is mainly based on the use of [ 18F]fluorodeoxyglucose (FDG) in oncology where it is most useful to localize primary tumours and their metastases.

  7. Feasibility of FDG-PET/CT for the initial diagnosis of papillary thyroid cancer.

    PubMed

    Kim, Heejin; Na, Kyung Jin; Choi, Jae Hyuk; Ahn, Byeong-Cheol; Ahn, Dongbin; Sohn, Jin Ho

    2016-06-01

    To assess the role of [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) as a preoperative diagnostic tool in papillary thyroid carcinoma (PTC). From 2011 to 2014, 197 patients with PTC (246 tumor foci in all) underwent FDG-PET. Among these patients, 46 underwent neck dissection for lateral neck metastasis. According to the FDG avidity of the tumor foci or lateral neck metastasis, factors associated with the prognostic value were evaluated by univariate and multivariate logistic regression analyses. Among the 197 patients, 7 (3.6 %) were incidentally found to have non-thyroid origin malignancy. Additionally, 63.0 % (155/246) of PTC foci showed FDG uptake on PET/CT. Univariate analysis showed that the tumor size, the presence of extrathyroidal extension, BRAF mutation, and Hashimoto thyroiditis were associated with FDG avidity. However, except for pathological extrathyroidal extension, the other factors showed statistically significant correlations with FDG avidity (p < 0.001, p = 0.008, and p = 0.009, respectively). FDG uptake in lateral neck node metastasis showed high specificity and negative predictive value (NPV). In four cases of nonspecific findings on ultrasonography (USG)/CT, FDG avidity was helpful to diagnose the presence of lateral neck metastasis. The maximum standardized uptake value (SUVmax) of PET/CT was correlated with the maximum diameter of the involved lateral node. FDG avidity did not show any significance in the recurrence-free survival of both the thyroid tumor and lateral neck metastasis. The FDG avidity of PTC did not show prognostic predictive meaning. However, in the case of lateral neck metastasis, FDG avidity showed high sensitivity and NPV, and could provide better information in cases of nonspecific findings on USG and CT. PMID:25971994

  8. 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.

  9. Positron Physics

    NASA Technical Reports Server (NTRS)

    Drachman, Richard J.

    2003-01-01

    I will give a review of the history of low-energy positron physics, experimental and theoretical, concentrating on the type of work pioneered by John Humberston and the positronics group at University College. This subject became a legitimate subfield of atomic physics under the enthusiastic direction of the late Sir Harrie Massey, and it attracted a diverse following throughout the world. At first purely theoretical, the subject has now expanded to include high brightness beams of low-energy positrons, positronium beams, and, lately, experiments involving anti-hydrogen atoms. The theory requires a certain type of persistence in its practitioners, as well as an eagerness to try new mathematical and numerical techniques. I will conclude with a short summary of some of the most interesting recent advances.

  10. Positron emission tomography and bone metastases.

    PubMed

    Fogelman, Ignac; Cook, Gary; Israel, Ora; Van der Wall, Hans

    2005-04-01

    The use of 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in the evaluation and management of patients with malignancy continues to increase. However, its role in the identification of bone metastases is far from clear. FDG has the advantage of demonstrating all metastatic sites, and in the skeleton it is assumed that its uptake is directly into tumor cells. It is probable that for breast and lung carcinoma, FDG-PET has similar sensitivity, although poorer specificity, when compared with the isotope bone scan, although there is conflicting evidence, with several articles suggesting that it is less sensitive than conventional imaging in breast cancer. There is convincing evidence that for prostate cancer, FDG-PET is less sensitive than the bone scan and this may be tumor specific. There is very little data relating to lymphoma, but FDG-PET seems to perform better than the bone scan. There is an increasing body of evidence relating to the valuable role of FDG-PET in myeloma, where it is clearly better than the bone scan, presumably because FDG is identifying marrow-based disease at an early stage. There are, however, several other important variables that should be considered. The morphology of the metastasis itself appears to be relevant. At least in breast cancer, different patterns of FDG uptake have been shown in sclerotic, lytic, or lesions with a mixed pattern, Furthermore, the precise localization of a metastasis in the skeleton may be important with regard to the extent of the metabolic response induced. Previous treatment is highly relevant and it has been found that although the majority of untreated bone metastases are positive on PET scans and have a lytic pattern on computed tomography (CT), after treatment, incongruent CT-positive/PET-negative lesions are significantly more prevalent and generally are blastic, which presumably reflects a direct effect of treatment. Finally, the aggressiveness of the tumor itself may be relevant

  11. 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

  12. Applications of 2-deoxy-2-fluoro-D-glucose (FDG) in Plant Imaging: Past, Present, and Future.

    PubMed

    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 [(18)F]fluorine-labeled glucose analog in which C-2 hydroxyl group has been replaced by a positron-emitting [(18)F] 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

  13. Formulation of the linear model from the nonlinear simulation for the F18 HARV

    NASA Technical Reports Server (NTRS)

    Hall, Charles E., Jr.

    1991-01-01

    The F-18 HARV is a modified F-18 Aircraft which is capable of flying in the post-stall regime in order to achieve superagility. The onset of aerodynamic stall, and continued into the post-stall region, is characterized by nonlinearities in the aerodynamic coefficients. These aerodynamic coefficients are not expressed as analytic functions, but rather in the form of tabular data. The nonlinearities in the aerodynamic coefficients yield a nonlinear model of the aircraft's dynamics. Nonlinear system theory has made many advances, but this area is not sufficiently developed to allow its application to this problem, since many of the theorems are existance theorems and that the systems are composed of analytic functions. Thus, the feedback matrices and the state estimators are obtained from linear system theory techniques. It is important, in order to obtain the correct feedback matrices and state estimators, that the linear description of the nonlinear flight dynamics be as accurate as possible. A nonlinear simulation is run under the Advanced Continuous Simulation Language (ACSL). The ACSL simulation uses FORTRAN subroutines to interface to the look-up tables for the aerodynamic data. ACSL has commands to form the linear representation for the system. Other aspects of this investigation are discussed.

  14. Actuated forebody strake controls for the F-18 high alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Murri, Daniel G.; Shah, Gautam H.; Dicarlo, Daniel J.; Trilling, Todd W.

    1993-01-01

    A series of ground-based studies have been conducted to develop actuated forebody strake controls for flight test evaluations using the NASA F-18 High-Alpha Research Vehicle. The actuated forebody strake concept has been designed to provide increased levels of yaw control at high angles of attack where conventional rudders become ineffective. Results are presented from tests conducted with the flight-test strake design, including static and dynamic wind-tunnel tests, transonic wind-tunnel tests, full-scale wind-tunnel tests, pressure surveys, and flow visualization tests. Results from these studies show that a pair of conformal actuated forebody strakes applied to the F-18 HARV can provide a powerful and precise yaw control device at high angles of attack. The preparations for flight testing are described, including the fabrication of flight hardware and the development of aircraft flight control laws. The primary objectives of the flight tests are to provide flight validation of the groundbased studies and to evaluate the use of this type of control to enhance fighter aircraft maneuverability.

  15. 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.

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

    SciTech Connect

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

    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.

  17. 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.

  18. 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.

  19. 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.

  20. Assessment of the biodistribution of an [18F]FDG-loaded perfluorocarbon double emulsion using dynamic micro-PET in rats

    PubMed Central

    Fabiilli, Mario L.; Piert, Morand R.; Koeppe, Robert A.; Sherman, Phillip S.; Quesada, Carole A.; Kripfgans, Oliver D.

    2013-01-01

    Perfluorocarbon (PFC) double emulsions loaded with a water-soluble, therapeutic agent can be triggered by ultrasound in a process known as acoustic droplet vaporization (ADV). Elucidating the stability and biodistribution of these sonosensitive vehicles and encapsulated agents are critical in developing targeted drug delivery strategies using ultrasound. [18F]fluorodeoxyglucose (FDG) was encapsulated in a PFC double emulsion and the in vitro diffusion of FDG was assessed using a Franz diffusion cell. Using dynamic micro positron emission tomography (micro-PET) and direct tissue sampling, the biodistribution of FDG administered as a solution (i.e. non-emulsified) or as an emulsion was studied in Fisher 344 rats (n = 6) bearing subcutaneous 9L gliosarcoma. Standardized uptake values (SUVs) and area under the curve of the SUV (AUCSUV) of FDG were calculated for various tissues. The FDG flux from the emulsion decreased by up to a factor of 6.9 compared to the FDG solution. FDG uptake, calculated from the AUCSUV, decreased by 36% and 44% for brain and tumor, respectively, when comparing FDG solution versus FDG emulsion (p < 0.01). Decreases in AUCSUV in highly metabolic tissues such as brain and tumor demonstrated retention of FDG within the double emulsion. No statistically significant differences in lung AUCSUV were observed, suggesting minimal accumulation of the emulsion in the pulmonary capillary bed. The liver AUCSUV increased by 356% for the FDG emulsion, thus indicating significant hepatic retention of the emulsion. PMID:23613440

  1. Positron annihilation gamma rays from novae

    NASA Technical Reports Server (NTRS)

    Leising, Mark D.; Clayton, Donald D.

    1987-01-01

    The potential for observing annihilation gamma rays from novae is investigated. These gamma rays, a unique signature of the thermonuclear runaway models of novae, would result from the annihilation of positrons emitted by beta(+)-unstable nuclei produced near the peak of the runaway and carried by rapid convection to the surface of the nova envelope. Simple models, which are extensions of detailed published models, of the expansion of the nova atmospheres are evolved. These models serve as input into investigations of the fate of nearby Galactic fast novae could yield detectable fluxes of electron-positron annihilation gamma rays produced by the decay of N-13 and F-18. Although nuclear gamma-ray lines are produced by other nuclei, it is unlikely that the fluxes at typical nova distances would be detectable to present and near-future instruments.

  2. Lymphadenopathy by Scrub Typhus Mimicking Metastasis on FDG PET/CT in a Patient with a History of Breast Cancer.

    PubMed

    Lee, Jeong Won; Lee, Sang Mi; Lee, Kyu Taek; Kim, Sung Young; Han, Sun Wook; Kim, Shin Young

    2015-06-01

    We report the case of a 60-year-old woman with left-sided breast cancer who showed lymphadenopathy mimicking metastatic lesions. She underwent surveillance (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) after treatment. PET/CT demonstrated multiple lymphadenopathies with increased FDG uptake, most notably in the right axilla. She had an eschar on the right axillary area, and her serologic test was positive for anti-Orientia tsutsugamushi IgM antibody. Ten months after the treatment, follow-up FDG PET/CT and ultrasonography showed improvement in generalized lymphadenopathy. PMID:26082810

  3. 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.

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

    DOE PAGESBeta

    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.; et al

    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

  5. FDG-PET/CT in staging of clear cell odontogenic carcinoma.

    PubMed

    Krishnamoorthy, R; Ravi Kumar, A S; Batstone, M

    2014-11-01

    Clear cell odontogenic carcinoma (CCOC) is a rare neoplasm; only 75 cases have been reported in the English language literature. They have a tendency for recurrence and a capacity to metastasize. There is very little known regarding the metabolic features of this tumour or the utility of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans in the staging and follow-up of these tumours. We present two cases of CCOC with their relevant FDG-PET/CT scan findings. The first patient had primary CCOC of the mandible that was FDG-avid, and the other had recurrence of CCOC of the anterior mandible and superomedial orbit that was not FDG-avid. FDG uptake in CCOC appears to be variable. Although FDG-PET/CT is useful in other head and neck cancers and has benefits compared to other imaging modalities, further studies are needed to investigate the sensitivity of FDG-PET/CT in CCOC. PMID:25015905

  6. FDG-PET improves accuracy in distinguishing frontotemporal dementia and Alzheimer's disease.

    PubMed

    Foster, Norman L; Heidebrink, Judith L; Clark, Christopher M; Jagust, William J; Arnold, Steven E; Barbas, Nancy R; DeCarli, Charles S; Turner, R Scott; Koeppe, Robert A; Higdon, Roger; Minoshima, Satoshi

    2007-10-01

    Distinguishing Alzheimer's disease (AD) and frontotemporal dementia (FTD) currently relies on a clinical history and examination, but positron emission tomography with [(18)F] fluorodeoxyglucose (FDG-PET) shows different patterns of hypometabolism in these disorders that might aid differential diagnosis. Six dementia experts with variable FDG-PET experience made independent, forced choice, diagnostic decisions in 45 patients with pathologically confirmed AD (n = 31) or FTD (n = 14) using five separate methods: (1) review of clinical summaries, (2) a diagnostic checklist alone, (3) summary and checklist, (4) transaxial FDG-PET scans and (5) FDG-PET stereotactic surface projection (SSP) metabolic and statistical maps. In addition, we evaluated the effect of the sequential review of a clinical summary followed by SSP. Visual interpretation of SSP images was superior to clinical assessment and had the best inter-rater reliability (mean kappa = 0.78) and diagnostic accuracy (89.6%). It also had the highest specificity (97.6%) and sensitivity (86%), and positive likelihood ratio for FTD (36.5). The addition of FDG-PET to clinical summaries increased diagnostic accuracy and confidence for both AD and FTD. It was particularly helpful when raters were uncertain in their clinical diagnosis. Visual interpretation of FDG-PET after brief training is more reliable and accurate in distinguishing FTD from AD than clinical methods alone. FDG-PET adds important information that appropriately increases diagnostic confidence, even among experienced dementia specialists. PMID:17704526

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

    PubMed

    Parkinson, Fiona E; Paul, Soumen; Zhang, Dali; Mzengeza, Shadreck; Ko, Ji Hyun

    2016-07-01

    2-(18) F-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

  8. 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. PMID:26576560

  9. 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.

  10. Distinguishing tumor recurrence from irradiation sequelae with positron emission tomography in patients treated for larynx cancer

    SciTech Connect

    Greven, K.M.; Williams, D.W. III; Keyes, J.W. Jr.; McGuirt, W.F.; Harkness, B.A.; Watson, N.E. Jr.; Raben, M.; Frazier, L.C.; Geisinger, K.R.; Capellari, J.O.

    1994-07-01

    Distinguishing persistent or recurrent tumor from postradiation edema, or soft tissue/cartilage necrosis in patients treated for carcinoma of the larynx can be difficult. Because recurrent tumor is often submucosal, multiple deep biopsies may be necessary before a diagnosis can be established. Positron emission tomography with 18F-2-fluro-2-deoxglucose (FDG) was studied for its ability to aid in this problem. Positron emission tomography (18FDG) scans were performed on 11 patients who were suspected of having persistent or recurrent tumor after radiation treatment for carcinoma of the larynx. Patients underwent thorough history and physical examinations, scans with computerized tomography, and pathologic evaluation when indicated. Standard uptake values were used to quantitate the FDG uptake in the larynx. The time between completion of radiation treatment and positron emission tomography examination ranged from 2 to 26 months with a median of 6 months. Ten patients underwent computed tomography (CT) of the larynx, which revealed edema of the larynx (six patients), glottic mass (four patients), and cervical nodes (one patient). Positron emission tomography scans revealed increased FDG uptake in the larynx in five patients and laryngectomy confirmed the presence of carcinoma in these patients. Five patients had positron emission tomography results consistent with normal tissue changes in the larynx, and one patient had increased FDG uptake in neck nodes. This patient underwent laryngectomy, and no cancer was found in the primary site, but nodes were pathologically positive. One patient had slightly elevated FDG uptake and negative biopsy results. The remaining patients have been followed for 11 to 14 months since their positron emission studies and their examinations have remained stable. In patients without tumor, average standard uptake values of the larynx ranged from 2.4 to 4.7, and in patients with tumor, the range was 4.9 to 10.7. 18 refs., 3 figs., 1 tab.

  11. 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.

  12. Positron emission tomography: An overview

    PubMed Central

    Shukla, A. K.; Kumar, Utham

    2006-01-01

    The rate of glucose utilization in tumor cells is significantly enhanced as compared to normal cells and this biochemical characteristic is utilized in PET imaging using FDG as a major workhorse. The PET systems as well as cyclotrons producing positron emitting radiopharmaceuticals have undergone continuous technological refinements. While PET (CT) systems enable fusion images as well as precise attenuation correction, the self-shielded cyclotrons developed provide dedicated systems for in-house production of a large number of PET radiopharmaceuticals. The application of PET images in oncology includes those of pulmonary, colorectal, breast, lymphoma, head & neck, bone, ovarian and GI cancers. The PET has been recognized as promising diagnostic tool to predict biological and physiological changes at the molecular level and hence offer a potential area for future applications including Stem Cell research. PMID:21206635

  13. FDG-PET/CT in lymphoma

    PubMed Central

    D'souza, Maria M; Jaimini, Abhinav; Bansal, Abhishek; Tripathi, Madhavi; Sharma, Rajnish; Mondal, Anupam; Tripathi, Rajendra Prashad

    2013-01-01

    Lymphomas are a heterogeneous group of diseases that arise from the constituent cells of the immune system or from their precursors. 18F-fludeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is now the cornerstone of staging procedures in the state-of-the-art management of Hodgkin's disease and aggressive non-Hodgkin's lymphoma. It plays an important role in staging, restaging, prognostication, planning appropriate treatment strategies, monitoring therapy, and detecting recurrence. However, its role in indolent lymphomas is still unclear and calls for further investigational trials. The protean PET/CT manifestations of lymphoma necessitate a familiarity with the spectrum of imaging findings to enable accurate diagnosis. A meticulous evaluation of PET/CT findings, an understanding of its role in the management of lymphomas, and knowledge of its limitations are mandatory for the optimal utilization of this technique. PMID:24604942

  14. 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. PMID:26319237

  15. FDG-PET study of patients with Leigh syndrome.

    PubMed

    Haginoya, Kauzhiro; Kaneta, Tomohiro; Togashi, Noriko; Hino-Fukuyo, Naomi; Kobayashi, Tomoko; Uematsu, Mitsugu; Kitamura, Taro; Inui, Takehiko; Okubo, Yukimune; Takezawa, Yusuke; Anzai, Mai; Endo, Wakaba; Miyake, Noriko; Saitsu, Hirotomo; Matsumoto, Naomichi; Kure, Shigeo

    2016-03-15

    We conducted a [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) study in five patients (median age 11 (range 4-13) years) with Leigh syndrome to evaluate its usefulness for understanding the functional brain dysfunction in this disease and in future drug trials. Four patients were found to have reported mitochondrial DNA gene mutations. The brain T2-weighted magnetic resonance imaging (MRI) showed high-intensity areas in the putamen bilaterally in five patients, caudate bilaterally in four, thalamus bilaterally in two, and brainstem in one. Cerebellar atrophy was observed in older two patients. For disease control, seven age-matched epilepsy patients who had normal MRI and FDG-PET studies were selected. For semiquantitative analysis of the lesions with decreased (18)F-FDG uptake, the mean standard uptake value (SUV) was calculated in regions of interest (ROIs) placed in each brain structure. We compared the SUV of nine segments (the frontal, temporal, parietal, and occipital lobes, thalami, basal ganglia, mid-brain, pons, and cerebellum) between patients with Leigh syndrome and controls. The glucose uptake was decreased significantly in the cerebellum and basal ganglia, which could explain the ataxia and dystonia in patients with Leigh syndrome. Although this study had some limitations, FDG-PET might be useful for evaluating the brain dysfunction and treatment efficacy of new drugs in patients with Leigh syndrome. Further study with more patients using advanced methods to quantify glucose uptake is needed before drawing a conclusion. PMID:26944169

  16. 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.

  17. The role of fluorine-18-fluorodeoxyglucose positron emission tomography in aggressive histological subtypes of thyroid cancer: an overview.

    PubMed

    Treglia, Giorgio; Annunziata, Salvatore; Muoio, Barbara; Salvatori, Massimo; Ceriani, Luca; Giovanella, Luca

    2013-01-01

    Aggressive histological subtypes of thyroid cancer are rare and have a poor prognosis. The most important aggressive subtypes of thyroid cancer are Hürthle cell carcinoma (HCTC) and anaplastic and poorly differentiated carcinoma (ATC and PDTC). The American Thyroid Association recently published guidelines for the management of patients with ATC, but no specific guidelines have been done about HCTC. We performed an overview of the literature about the role of Fluorine-18-Fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (FDG-PET or PET/CT) in aggressive histological subtypes of thyroid cancer. Only few original studies about the role of FDG-PET or PET/CT in HCTC, PDTC, and ATC have been published in the literature. FDG-PET or PET/CT seems to be useful in staging or followup of invasive and metastatic HCTC. FDG-PET or PET/CT should be used in patients with ATC in initial staging and in the followup after surgery to evaluate metastatic disease. Some authors suggest the use of FDG-PET/CT in staging of PDTC, but more studies are needed to define the diagnostic use of FDG-PET/CT in this setting. Limited experience suggests the usefulness of FDG-PET or PET/CT in patients with more aggressive histological subtypes of DTC. However, DTC presenting as radioiodine refractory and FDG-PET positive should be considered aggressive tumours with poor prognosis. PMID:23653645

  18. 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

  19. Altered Leukotriene B4 metabolism in CYP4F18-deficient mice does not impact inflammation following renal ischemia

    PubMed Central

    Winslow, Valeria; Vaivoda, Rachel; Vasilyev, Aleksandr; Dombkowski, David; Douaidy, Karim; Stark, Christopher; Drake, Justin; Guilliams, Evin; Choudhary, Dharamainder; Preffer, Frederic; Stoilov, Ivaylo; Christmas, Peter

    2014-01-01

    Inflammatory responses to infection and injury must be restrained and negatively regulated to minimize damage to host tissue. One proposed mechanism involves enzymatic inactivation of the pro-inflammatory mediator leukotriene B4, but it is difficult to dissect the roles of various metabolic enzymes and pathways. A primary candidate for a regulatory pathway is omega oxidation of leukotriene B4 in neutrophils, presumptively by CYP4F3A in humans and CYP4F18 in mice. This pathway generates ω, ω-1, and ω-2 hydroxylated products of leukotriene B4, depending on species. We created mouse models targeting exons 8 and 9 of the Cyp4f18 allele that allows both conventional and conditional knockout of Cyp4f18. Neutrophils from wild-type mice convert leukotriene B4 to 19-hydroxy leukotriene B4, and to a lesser extent 18-hydroxy leukotriene B4, whereas these products were not detected in neutrophils from conventional Cyp4f18 knockouts. A mouse model of renal ischemia-reperfusion injury was used to investigate the consequences of loss of CYP4F18 in vivo. There were no significant changes in infiltration of neutrophils and other leukocytes into kidney tissue as determined by flow cytometry and immunohistochemistry, or renal injury as assessed by histological scoring and measurement of blood urea nitrogen. It is concluded that CYP4F18 is necessary for omega oxidation of leukotriene B4 in neutrophils, and is not compensated by other CYP enzymes, but loss of this metabolic pathway is not sufficient to impact inflammation and injury following renal ischemia-reperfusion in mice. PMID:24632148

  20. 18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals derived from a single-institution 18F-FDG-directed surgery experience: feasibility and quantification of 18F-FDG accumulation within 18F-FDG-avid lesions and background tissues

    PubMed Central

    2014-01-01

    Background 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is a well-established imaging modality for a wide variety of solid malignancies. Currently, only limited data exists regarding the utility of PET/CT imaging at very extended injection-to-scan acquisition times. The current retrospective data analysis assessed the feasibility and quantification of diagnostic 18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals. Methods 18F-FDG-avid lesions (not surgically manipulated or altered during 18F-FDG-directed surgery, and visualized both on preoperative and postoperative 18F-FDG PET/CT imaging) and corresponding background tissues were assessed for 18F-FDG accumulation on same-day preoperative and postoperative 18F-FDG PET/CT imaging. Multiple patient variables and 18F-FDG-avid lesion variables were examined. Results For the 32 18F-FDG-avid lesions making up the final 18F-FDG-avid lesion data set (from among 7 patients), the mean injection-to-scan times of the preoperative and postoperative 18F-FDG PET/CT scans were 73 (±3, 70-78) and 530 (±79, 413-739) minutes, respectively (P < 0.001). The preoperative and postoperative mean 18F-FDG-avid lesion SUVmax values were 7.7 (±4.0, 3.6-19.5) and 11.3 (±6.0, 4.1-29.2), respectively (P < 0.001). The preoperative and postoperative mean background SUVmax values were 2.3 (±0.6, 1.0-3.2) and 2.1 (±0.6, 1.0-3.3), respectively (P = 0.017). The preoperative and postoperative mean lesion-to-background SUVmax ratios were 3.7 (±2.3, 1.5-9.8) and 5.8 (±3.6, 1.6-16.2), respectively, (P < 0.001). Conclusions 18F-FDG PET/CT oncologic imaging can be successfully performed at extended injection-to-scan acquisition time intervals of up to approximately 5 half-lives for 18F-FDG while maintaining good/adequate diagnostic image quality. The resultant increase in the 18F-FDG-avid lesion SUVmax values, decreased background SUVmax values, and

  1. Hypertrophic pulmonary osteoarthropathy on bone scintigraphy and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in a patient with lung adenocarcinoma

    PubMed Central

    Cengiz, Arzu; Eren, Mine Şencan; Polatli, Mehmet; Yürekli, Yakup

    2015-01-01

    Hypertrophic pulmonary osteoarthropathy (HPOA) is not an uncommon paraneoplastic syndrome that is frequently associated with lung cancer. A 54-year-old male patient with lung adenocarcinoma underwent bone scintigraphy and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scanning for initial staging. Bone scintigraphy revealed increased periosteal activity in lower extremities. FDG PET/CT revealed hypermetabolic right lung mass, mediastinal lymph nodes, and mildly increased periosteal FDG uptake in both femurs and tibias. The findings in lower extremities on bone scan and FDG PET/CT were interpreted as HPOA. PMID:26170569

  2. Hypertrophic pulmonary osteoarthropathy on bone scintigraphy and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in a patient with lung adenocarcinoma.

    PubMed

    Cengiz, Arzu; Eren, Mine Şencan; Polatli, Mehmet; Yürekli, Yakup

    2015-01-01

    Hypertrophic pulmonary osteoarthropathy (HPOA) is not an uncommon paraneoplastic syndrome that is frequently associated with lung cancer. A 54-year-old male patient with lung adenocarcinoma underwent bone scintigraphy and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scanning for initial staging. Bone scintigraphy revealed increased periosteal activity in lower extremities. FDG PET/CT revealed hypermetabolic right lung mass, mediastinal lymph nodes, and mildly increased periosteal FDG uptake in both femurs and tibias. The findings in lower extremities on bone scan and FDG PET/CT were interpreted as HPOA. PMID:26170569

  3. Positron emission tomographic imaging of tumors using monoclonal antibodies. Progress report, April 15, 1992--October 31, 1992

    SciTech Connect

    Zalutsky, M.R.

    1992-08-01

    This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. The Role of 18F-Fluorodeoxyglucose Positron Emission Tomography in Thyroid Neoplasms

    PubMed Central

    Law, Tsz Ting

    2011-01-01

    18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has established itself as an important imaging modality in many oncological and nononcological specialties and, as a consequence, it is increasingly being used in clinical practice. Since the first report of FDG being taken up by metastatic differentiated thyroid carcinoma (DTC) cells >20 years ago, various groups of investigators have explored the potential role of FDG-PET scanning in patients with benign and malignant thyroid neoplasms. With the increasing demand for FDG-PET scanning, clinicians are faced with the challenge of managing an increasing number of FDG-PET–detected thyroid incidentalomas because their significance remains unclear. The aims of this review are to address some of these issues, specifically, the clinical significance of FDG-PET–detected thyroid incidentalomas, the ability of FDG-PET to characterize thyroid nodules, especially those with indeterminate fine needle aspiration cytology results, and the role of FDG-PET in patients with confirmed primary DTC and with suspected recurrent DTC, by reviewing the current literature. PMID:21378078

  14. 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.

  15. Present and future roles of FDG-PET/CT imaging in the management of lung cancer.

    PubMed

    Kitajima, Kazuhiro; Doi, Hiroshi; Kanda, Tomonori; Yamane, Tomohiko; Tsujikawa, Tetsuya; Kaida, Hayato; Tamaki, Yukihisa; Kuribayashi, Kozo

    2016-06-01

    Integrated positron emission tomography/computed tomography (PET/CT) using 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) has emerged as a powerful tool for combined metabolic and anatomic evaluation in clinical oncologic imaging. This review discusses the utility of (18)F-FDG PET/CT as a tool for managing patients with lung cancer. We discuss different patient management stages, including diagnosis, initial staging, therapy planning, early treatment response assessment, re-staging, and prognosis. PMID:27121156

  16. 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.

  17. Clinical significance of patterns of incidental thyroid uptake at (18)F-FDG PET/CT.

    PubMed

    Agrawal, K; Weaver, J; Ngu, R; Krishnamurthy Mohan, H

    2015-05-01

    Incidental uptake of 2-[(18)F]-fluoro-2-deoxy-d-glucose ((18)F-FDG) in the thyroid gland is not uncommonly encountered in day-to-day practice of oncological (18)F-FDG positron-emission tomography/computed tomography (PET/CT). These are often felt to be "nuisance lesions" by referring clinicians and radiologists alike. However, recognition of the importance of different patterns of FDG uptake in the thyroid gland and knowledge of the possible underlying aetiologies are crucial in ensuring that patients are managed appropriately in the clinical context of their primary diagnosis, as the underlying pathological condition may be clinically important in a significant minority of such cases. This review describes the various patterns of (18)F-FDG uptake within the thyroid and discusses the clinical significance and possible impact on patient management. Incidental low-grade homogeneous diffuse increased thyroid (18)F-FDG uptake is usually seen in the patients with chronic thyroiditis, Grave's disease, and hypothyroidism. Thyroid function tests and antibody profiling are advised in these patients. Incidental focal (18)F-FDG thyroid uptake should raise the possibility of underlying malignancy. Ultrasound with or without fine-needle aspiration cytology is usually recommended for the evaluation of these lesions. Heterogeneous uptake with prominent focal uptake in the thyroid should be further evaluated to exclude malignancy. PMID:25687827

  18. 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.

  19. 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.

  20. 18F-Fluoride bone positron emission tomography demonstrating changes related to finger clubbing and hypertrophic osteoarthropathy.

    PubMed

    Kashyap, Raghava; Ali, Mirza Athar; Nagaraju, Madhusudhan; Muntimadugu, Babaiah

    2014-04-01

    Hypertrophic pulmonary osteoarthropathy is manifested by clubbing and periostitis of bones. We present a very rare documentation of increased F18-sodium fluoride uptake in the distal phalanges of both hands correlating to clubbing of the fingers in a 55-year-old female patient with carcinoma of lung in whom bone positron emission tomography was performed for metastatic work-up. PMID:24761070

  1. Clinical, pathological and (18)F-FDG PET/CT findings in synchronous primary vaginal and endometrial cancers.

    PubMed

    Gunes, Burcak Yilmaz; Akbayır, Ozgur; Demirci, Emre; Ozaydin, Ipek

    2016-01-01

    Synchronous primary gynecologic malignancies are infrequently seen. In this report, we describe the clinical, pathological and fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) findings of a patient with synchronous primary vaginal and endometrial cancers. To our knowledge, this is the first such case described in the literature. PMID:27331214

  2. Utility of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in a child with chronic granulomatous disease.

    PubMed

    Garg, Gunjan; DaSilva, Raphaella; Bhalakia, Avni; Milstein, David M

    2016-01-01

    We report the fluorodeoxyglucose positron emission tomography/computed tomography (FDG - PET/CT) findings in an 11-month-old boy with suspected milk protein allergy, presented to the hospital with 2-month history of fever of unknown origin and failure to thrive. It showed FDG avid lymphadenopathy above and below the diaphragm and splenic focus, which could represent diffuse inflammatory process or lymphoma. Subsequent jejunal biopsy showed non-necrotizing granulomas. PMID:26917900

  3. Utility of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in a child with chronic granulomatous disease

    PubMed Central

    Garg, Gunjan; DaSilva, Raphaella; Bhalakia, Avni; Milstein, David M.

    2016-01-01

    We report the fluorodeoxyglucose positron emission tomography/computed tomography (FDG - PET/CT) findings in an 11-month-old boy with suspected milk protein allergy, presented to the hospital with 2-month history of fever of unknown origin and failure to thrive. It showed FDG avid lymphadenopathy above and below the diaphragm and splenic focus, which could represent diffuse inflammatory process or lymphoma. Subsequent jejunal biopsy showed non-necrotizing granulomas. PMID:26917900

  4. Incidental finding of silent appendicitis on (18)F-FDG PET/CT in a patient with small cell lung adenocarcinoma.

    PubMed

    Bourgeois, Sophie; Van Den Berghe, Ivo; De Geeter, Frank

    2016-01-01

    We report the incidental diagnosis of acute asymptomatic appendicitis on a fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography ((18)F-FDG PET/CT) performed for staging of a non small cell lung carcinoma. The patient was asymptomatic and laboratory tests were normal. The case illustrates: a) the possibility to diagnose appendicitis on (18)F-FDG PET/CT and b) the possibility of silent acute appendicitis, although this is a rare occurrence. PMID:27331212

  5. Does Delayed-Time-Point Imaging Improve 18F-FDG-PET in Patients With MALT Lymphoma?

    PubMed Central

    Mayerhoefer, Marius E.; Giraudo, Chiara; Senn, Daniela; Hartenbach, Markus; Weber, Michael; Rausch, Ivo; Kiesewetter, Barbara; Herold, Christian J.; Hacker, Marcus; Pones, Matthias; Simonitsch-Klupp, Ingrid; Müllauer, Leonhard; Dolak, Werner; Lukas, Julius; Raderer, Markus

    2016-01-01

    Purpose To determine whether in patients with extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue lymphoma (MALT), delayed–time-point 2-18F-fluoro-2-deoxy-d-glucose-positron emission tomography (18F-FDG-PET) performs better than standard–time-point 18F-FDG-PET. Materials and Methods Patients with untreated histologically verified MALT lymphoma, who were undergoing pretherapeutic 18F-FDG-PET/computed tomography (CT) and consecutive 18F-FDG-PET/magnetic resonance imaging (MRI), using a single 18F-FDG injection, in the course of a larger-scale prospective trial, were included. Region-based sensitivity and specificity, and patient-based sensitivity of the respective 18F-FDG-PET scans at time points 1 (45–60 minutes after tracer injection, TP1) and 2 (100–150 minutes after tracer injection, TP2), relative to the reference standard, were calculated. Lesion-to-liver and lesion-to-blood SUVmax (maximum standardized uptake values) ratios were also assessed. Results 18F-FDG-PET at TP1 was true positive in 15 o f 23 involved regions, and 18F-FDG-PET at TP2 was true-positive in 20 of 23 involved regions; no false-positive regions were noted. Accordingly, region-based sensitivities and specificities were 65.2% (confidence interval [CI], 45.73%–84.67%) and 100% (CI, 100%-100%) for 18F-FDG-PET at TP1; and 87.0% (CI, 73.26%–100%) and 100% (CI, 100%-100%) for 18F-FDG-PET at TP2, respectively. FDG-PET at TP1 detected lymphoma in at least one nodal or extranodal region in 7 of 13 patients, and 18F-FDG-PET at TP2 in 10 of 13 patients; accordingly, patient-based sensitivity was 53.8% (CI, 26.7%–80.9%) for 18F-FDG-PET at TP1, and 76.9% (CI, 54.0%–99.8%) for 18F-FDG-PET at TP2. Lesion-to-liver and lesion-to-blood maximum standardized uptake value ratios were significantly lower at TP1 (ratios, 1.05 ± 0.40 and 1.52 ± 0.62) than at TP2 (ratios, 1.67 ± 0.74 and 2.56 ± 1.10; P = 0.003 and P = 0.001). Conclusions Delayed–time-point imaging

  6. 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

  7. 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

  8. Genome sequences and phylogenetic analysis of K88- and F18-positive porcine enterotoxigenic Escherichia coli.

    PubMed

    Shepard, Sara M; Danzeisen, Jessica L; Isaacson, Richard E; Seemann, Torsten; Achtman, Mark; Johnson, Timothy J

    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

  9. Recurrent tumor vs radiation effects after Gamma Knife radiosurgery of intracerebral metastases: Diagnosis with PET-FDG

    SciTech Connect

    Mogard, J.; Kihlstroem, L.; Ericson, K. |

    1994-03-01

    Our objective was to differentiate radiation effects from tumor progression in metastases stereotaxically irradiated with the multicobalt unit (Gamma Knife). Eleven patients with stereotaxically irradiated cerebral metastases were examined with PET using [{sup 18}F]fluorodeoxyglucose (FDG) to differentiate recurrent tumor from radiation effects. Six patients had increased uptake of FDG, and clinical, radiological, and pathological findings confirmed the diagnosis of recurrent metastases. These patients had an unfavorable prognosis and were all dead within 54 weeks after radiosurgery. Five patients had lesions without an increased accumulation of FDG. Four of these patients were alive after a total follow-up of 1.7 years, while one patient died of a peptic ulcer 56 weeks after radiosurgery. Positron emission tomography with FDG was of obvious prognostic value in this small series of patients and was clearly superior to CT and MR in the distinction between tumor recurrence and radiation effects (verified necrosis in one case). 24 refs., 2 figs., 2 tabs.

  10. FDG PET in the evaluation of the aggressiveness of pulmonary adenocarcinoma: correlation with histopathological features.

    PubMed

    Higashi, K; Ueda, Y; Ayabe, K; Sakurai, A; Seki, H; Nambu, Y; Oguchi, M; Shikata, H; Taki, S; Tonami, H; Katsuda, S; Yamamoto, I

    2000-08-01

    2-[Fluorine-18]fluoro-2-deoxy-d-glucose (FDG) uptake within the primary lesion correlates with survival on positron emission tomography (PET) studies of patients with non-small cell lung cancer. The more metabolically active the tumour, the worse the outcome. The aim of this study was to determine whether a correlation exists between aggressiveness as determined by pathology and the findings of FDG PET in pulmonary adenocarcinoma. Thirty-five patients with 38 adenocarcinomas of the lung were studied. All patients underwent thoracotomy within 4 weeks of the FDG PET study. For semiquantitative analysis, standardized uptake values (SUVs) were calculated. Patients were classified into high SUV (> or = 4.0) and low SUV (<4.0) groups. The degree of FDG uptake (SUVs) in primary lung lesions was correlated with the histopathological features of aggressiveness (pleural involvement, vascular invasion or lymphatic permeation). The mean SUV of aggressive adenocarcinomas (4.36+/-1.94, n = 22) was higher than that of non-aggressive ones (1.53+/-0.88, n = 16) (P < 0.0001). Tumours with a high FDG uptake have a significantly higher likelihood of aggressiveness than those with a low FDG uptake (P = 0.0004). Analysis by the Kaplan-Meier methods revealed that the groups had different prognoses (log-rank test, P = 0.0099). The high SUV group had a significantly worse prognosis. In conclusion, a correlation was seen between aggressiveness as determined by pathology and glucose metabolism as measured by FDG PET in adenocarcinoma of the lung. FDG PET may be used as a non-invasive diagnostic technique in measuring aggressiveness and prognosis in patients with pulmonary adenocarcinoma. PMID:11039452