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Sample records for choline pet based

  1. Usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base: comparison with FDG-PET

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    Ito Shin

    2012-02-01

    Full Text Available Abstract Background Choline is a new PET tracer that is useful for the detection of malignant tumor. Choline is a precursor of the biosynthesis of phosphatidylcholine, a major phospholipid in the cell membrane of eukaryotic cells. Malignant tumors have an elevated level of phosphatidylcholine in cell membrane. Thus, choline is a marker of tumor malignancy. Method The patient was a 51-year-old man with repeated recurrent hemangiopericytoma in the skull base. We performed Choline-PET in this patient after various treatments and compared findings with those of FDG-PET. Results Choline accumulated in this tumor, but FDG did not accumulate. We diagnosed this tumor as residual hemangiopericytoma and performed the resection of the residual tumor. FDG-PET is not appropriate for skull base tumor detection because uptake in the brain is very strong. Conclusion We emphasize the usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base after various treatments, compared with FDG-PET.

  2. Choline PET based dose-painting in prostate cancer - Modelling of dose effects

    International Nuclear Information System (INIS)

    Niyazi, Maximilian; Bartenstein, Peter; Belka, Claus; Ganswindt, Ute

    2010-01-01

    Several randomized trials have documented the value of radiation dose escalation in patients with prostate cancer, especially in patients with intermediate risk profile. Up to now dose escalation is usually applied to the whole prostate. IMRT and related techniques currently allow for dose escalation in sub-volumes of the organ. However, the sensitivity of the imaging modality and the fact that small islands of cancer are often dispersed within the whole organ may limit these approaches with regard to a clear clinical benefit. In order to assess potential effects of a dose escalation in certain sub-volumes based on choline PET imaging a mathematical dose-response model was developed. Based on different assumptions for α/β, γ50, sensitivity and specificity of choline PET, the influence of the whole prostate and simultaneous integrated boost (SIB) dose on tumor control probability (TCP) was calculated. Based on the given heterogeneity of all potential variables certain representative permutations of the parameters were chosen and, subsequently, the influence on TCP was assessed. Using schedules with 74 Gy within the whole prostate and a SIB dose of 90 Gy the TCP increase ranged from 23.1% (high detection rate of choline PET, low whole prostate dose, high γ50/ASTRO definition for tumor control) to 1.4% TCP gain (low sensitivity of PET, high whole prostate dose, CN + 2 definition for tumor control) or even 0% in selected cases. The corresponding initial TCP values without integrated boost ranged from 67.3% to 100%. According to a large data set of intermediate-risk prostate cancer patients the resulting TCP gains ranged from 22.2% to 10.1% (ASTRO definition) or from 13.2% to 6.0% (CN + 2 definition). Although a simplified mathematical model was employed, the presented model allows for an estimation in how far given schedules are relevant for clinical practice. However, the benefit of a SIB based on choline PET seems less than intuitively expected. Only under the

  3. Choline-PET/CT for imaging prostate cancer; Cholin-PET/CT zur Bildgebung des Prostatakarzinoms

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    Krause, Bernd Joachim [Klinik- und Poliklinik fuer Nuklearmedizin, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany); Treiber, U.; Schwarzenboeck, S.; Souvatzoglou, M. [Klinik fuer Urologie, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany)

    2010-09-15

    PET and PET/CT using [{sup 11}C]- and [{sup 18}F]-labelled choline derivatives are increasingly being used for imaging of prostate cancer. The value of PET and PET/CT with [{sup 11}C]- and [{sup 18}F]-labelled choline derivates in biochemical recurrence of prostate cancer has been examined in many studies and demonstrates an increasing importance. Primary prostate cancer can be detected with moderate sensitivity using PET and PET/CT using [{sup 11}C]- and [{sup 18}F]-labelled choline derivatives - the differentiation between benign prostatic hyperplasia, prostatitis or high-grade intraepithelial neoplasia (HGPIN) is not always possible. At the present time [{sup 11}C]choline PET/CT is not recommended in the primary setting but may be utilized in clinically suspected prostate cancer with repeatedly negative prostate biopsies, in preparation of a focused re-biopsy. Promising results have been obtained for the use of PET and PET/CT with [{sup 11}C]- and [{sup 18}F]-labelled choline derivates in patients with biochemical recurrence. The detection rate of choline PET and PET/CT for local, regional, and distant recurrence in patients with a biochemical recurrence shows a linear correlation with PSA values at the time of imaging and reaches about 75% in patients with PSA > 3 ng/mL. At PSA values below 1 ng/mL, the recurrence can be diagnosed with choline PET/CT in approximately 1/3 of the patients. PET and PET/CT with [{sup 11}C]- and [{sup 18}F]choline derivates can be helpful for choosing a therapeutic strategy in the sense of an individualized treatment: since an early diagnosis of recurrence is crucial to the choice of optimal treatment. The localization of the site of recurrence - local recurrence, lymph node metastasis or systemic dissemination - has important influence on the therapy regimen. (orig.)

  4. Role of choline PET/CT in guiding target volume delineation for irradiation of prostate cancer

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    Schwarzenboeck, S.M.; Kurth, J. [University Medical Centre Rostock, Department of Nuclear Medicine, Rostock (Germany); Gocke, C.; Kuhnt, T.; Hildebrandt, G. [University Medical Centre Rostock, Department of Radiotherapy, Rostock (Germany); Krause, B.J. [University Medical Centre Rostock, Department of Nuclear Medicine, Rostock (Germany); Universitaet Rostock, Department of Nuclear Medicine, Universitaetsmedizin Rostock, Rostock (Germany)

    2013-07-15

    Choline PET/CT has shown limitations for the detection of primary prostate cancer and nodal metastatic disease, mainly due to limited sensitivity and specificity. Conversely in the restaging of prostate cancer recurrence, choline PET/CT is a promising imaging modality for the detection of local regional and nodal recurrence with an impact on therapy management. This review highlights current literature on choline PET/CT for radiation treatment planning in primary and recurrent prostate cancer. Due to limited sensitivity and specificity in differentiating between benign and malignant prostatic tissues in primary prostate cancer, there is little enthusiasm for target volume delineation based on choline PET/CT. Irradiation planning for the treatment of single lymph node metastases on the basis of choline PET/CT is controversial due to its limited lesion-based sensitivity in primary nodal staging. In high-risk prostate cancer, choline PET/CT might diagnose lymph node metastases, which potentially can be included in the conventional irradiation field. Prior to radiation treatment of recurrent prostate cancer, choline PET/CT may prove useful for patient stratification by excluding distant disease which would require systemic therapy. In patients with local recurrence, choline PET/CT can be used to delineate local sites of recurrence within the prostatic resection bed allowing a boost to PET-positive sites. In patients with lymph node metastases outside the prostatic fossa and regional metastatic lymph nodes, choline PET/CT might influence radiation treatment planning by enabling extension of the target volume to lymphatic drainage sites with or without a boost to PET-positive lymph nodes. Further clinical randomized trials are required to assess treatment outcomes following choline-based biological radiation treatment planning in comparison with conventional radiation treatment planning. (orig.)

  5. Value of {sup 11}C-choline PET and PET/CT in patients with suspected prostate cancer

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    Scher, Bernhard; Albinger, Wolfram; Tiling, Reinhold; Gildehaus, Franz-Josef; Dresel, Stefan [University of Munich, Department of Nuclear Medicine, Munich (Germany); Seitz, Michael [University of Munich, Department of Urology, Munich (Germany); Scherr, Michael; Becker, Hans-Christoph [University of Munich, Department of Radiology, Munich (Germany); Souvatzogluou, Michael; Wester, Hans-Juergen [Technical University of Munich, Department of Nuclear Medicine, Munich (Germany)

    2007-01-15

    The value and limitations of {sup 11}C-choline PET and PET/CT for the detection of prostate cancer remain controversial. The aim of this study was to investigate the diagnostic efficacy of {sup 11}C-choline PET and PET/CT in a large group of patients with suspected prostate cancer. Fifty-eight patients with clinical suspicion of prostate cancer underwent {sup 11}C-choline PET (25/58, Siemens ECAT Exact HR+) or PET/CT (33/58, Philips Gemini) scanning. On average, 500 MBq of {sup 11}C-choline was administered intravenously. Studies were interpreted by raters blinded to clinical information and other diagnostic procedures. Qualitative image analysis as well as semiquantitative SUV measurement was carried out. The reference standard was histopathological examination of resection specimens or biopsy. Prevalence of prostate cancer in this selected patient population was 63.8% (37/58). {sup 11}C-choline PET and PET/CT showed a sensitivity of 86.5% (32/37) and a specificity of 61.9% (13/21) in the detection of the primary malignancy. With regard to metastatic spread, PET showed a per-patient sensitivity of 81.8% (9/11) and produced no false positive findings. Based on our findings, differentiation between benign prostatic changes, such as benign prostatic hyperplasia or prostatitis, and prostate cancer is feasible in the majority of cases when image interpretation is primarily based on qualitative characteristics. SUV{sub max} may serve as guidance. False positive findings may occur due to an overlap of {sup 11}C-choline uptake between benign and malignant processes. By providing functional information regarding both the primary malignancy and its metastases, {sup 11}C-choline PET may prove to be a useful method for staging prostate cancer. (orig.)

  6. 11C-Choline PET/pathology image coregistration in primary localized prostate cancer

    International Nuclear Information System (INIS)

    Grosu, Anca-Ligia; Prokic, Vesna; Weirich, Gregor; Wendl, Christina; Geinitz, Hans; Molls, Michael; Kirste, Simon; Souvatzoglou, Michael; Schwaiger, Markus; Gschwend, Juergen E.; Treiber, Uwe; Weber, Wolfgang A.; Krause, Bernd Joachim

    2014-01-01

    The aim of this study was to develop a methodology for the comparison of pathology specimens after prostatectomy (post-S) with PET images obtained before surgery (pre-S). This method was used to evaluate the merit of 11 C-choline PET/CT for delineation of gross tumour volume (GTV) in prostate cancer (PC). In 28 PC patients, 11 C-choline PET/CT was performed before surgery. PET/CT data were coregistered with the pathology specimens. GTV on PET images (GTV-PET) was outlined automatically and corrected manually. Tumour volume in the prostate (TVP) was delineated manually on the pathology specimens. Based on the coregistered PET/pathology images, the following parameters were assessed: SUVmax and SUVmean in the tumoral and nontumoral prostate (NP), GTV-PET (millilitres) and TVP (millilitres). PET/pathology image coregistration was satisfactory. Mean SUVmax in the TVP was lower than in the NP: 5.0 and 5.5, respectively (p = 0.093). Considering the entire prostate, SUVmax was located in the TVP in two patients, in the TVP and NP in 12 patients and exclusively in NP in 14 patients. Partial overlap the TVP and GTV-PET was seen in 71 % of patients, and complete overlap in 4 %. PET/pathology image coregistration can be used for evaluation of different imaging modalities. 11 C-Choline PET failed to distinguish tumour from nontumour tissue. (orig.)

  7. Evaluation of the PET component of simultaneous [18F]choline PET/MRI in prostate cancer: comparison with [18F]choline PET/CT

    International Nuclear Information System (INIS)

    Wetter, Axel; Lipponer, Christine; Nensa, Felix; Altenbernd, Jens-Christian; Schlosser, Thomas; Lauenstein, Thomas; Heusch, Philipp; Ruebben, Herbert; Bockisch, Andreas; Poeppel, Thorsten; Nagarajah, James

    2014-01-01

    The aim of this study was to evaluate the positron emission tomography (PET) component of [ 18 F]choline PET/MRI and compare it with the PET component of [ 18 F]choline PET/CT in patients with histologically proven prostate cancer and suspected recurrent prostate cancer. Thirty-six patients were examined with simultaneous [ 18 F]choline PET/MRI following combined [ 18 F]choline PET/CT. Fifty-eight PET-positive lesions in PET/CT and PET/MRI were evaluated by measuring the maximum and mean standardized uptake values (SUV max and SUV mean ) using volume of interest (VOI) analysis. A scoring system was applied to determine the quality of the PET images of both PET/CT and PET/MRI. Agreement between PET/CT and PET/MRI regarding SUV max and SUV mean was tested using Pearson's product-moment correlation and Bland-Altman analysis. All PET-positive lesions that were visible on PET/CT were also detectable on PET/MRI. The quality of the PET images was comparable in both groups. Median SUV max and SUV mean of all lesions were significantly lower in PET/MRI than in PET/CT (5.2 vs 6.1, p max of PET/CT and PET/MRI (R = 0.86, p mean of PET/CT and PET/MRI (R = 0.81, p max of PET/CT vs PET/MRI and -1.12 to +2.23 between SUV mean of PET/CT vs PET/MRI. PET image quality of PET/MRI was comparable to that of PET/CT. A highly significant correlation between SUV max and SUV mean was found. Both SUV max and SUV mean were significantly lower in [ 18 F]choline PET/MRI than in [ 18 F]choline PET/CT. Differences of SUV max and SUV mean might be caused by different techniques of attenuation correction. Furthermore, differences in biodistribution and biokinetics of [ 18 F]choline between the subsequent examinations and in the respective organ systems have to be taken into account. (orig.)

  8. Role of carbon-11 choline PET/CT in the management of uterine carcinoma. Initial experience

    International Nuclear Information System (INIS)

    Sofue, Keitaro; Sawada, Morio; Arai, Yasuaki; Tateishi, Ukihide; Inoue, Tomio; Maeda, Tetsuo; Sugimura, Kazuro; Terauchi, Takashi; Kano, Daisuke

    2009-01-01

    The present study was conducted to clarify the role of carbon-11 choline ( 11 C-choline) positron emission tomography (PET)/computed tomography (CT) in the management of uterine carcinoma. Twenty-two patients who underwent 11 C-choline PET/CT and pelvic MRI were evaluated retrospectively. The images were reviewed by a board-certified radiologist and a nuclear medicine specialist who were unaware of any clinical information, and a consensus was reached. Diagnostic accuracy of PET/CT was evaluated for staging. The reference standard consisted of histological examination (n=17) and follow-up conventional CT (n=5). In five patients with cervical carcinoma, 11 C-choline PET/CT was performed before and after treatment that consisted of cisplatin infusion and subsequent radiotherapy. Standardized uptake value (SUV) was compared with unidimensional and volumetric measurements that were made on magnetic resonance images (MRI) before and after treatment. Based on PET/CT interpretations, the reviewers correctly classified tumor (T) stage in 8 patients (47%), nodes (N) stage in 21 patients (96%), metastasis (M) stage in 20 patients (91%), and tumor, nodes and metastasis (TNM) stage in 15 patients (88%). Tumor size, volume, and SUV decreased after treatment in five patients with cervical carcinoma. Using the Pearson correlation test, a significant correlation was found between the reduction rate of SUV and reduction rate of tumor volume. 11 C-choline PET/CT is an accurate means for the management of patients with uterine carcinoma. The combination of 11 C-choline PET/CT and MRI increases the accuracy of staging in patients with uterine carcinoma. (author)

  9. {sup 18}F-Choline, {sup 11}C-choline and {sup 11}C-acetate PET/CT: comparative analysis for imaging prostate cancer patients

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    Brogsitter, Claudia; Zoephel, Klaus; Kotzerke, Joerg [Carl Gustav Carus Medical School, University of Dresden, Department of Nuclear Medicine, Dresden (Germany)

    2013-07-15

    Prostate cancer (PCA) is the second most common tumour in men worldwide. Whereas prostate specific antigen (PSA) is an established biochemical marker, the optimal imaging method for all clinical scenarios has not yet been found. With the rising number of PET centres there is an increasing availability and use of {sup 18}F-/{sup 11}C-choline or {sup 11}C-acetate for staging of PCA. However, to date no final conclusion has been reached as to whether acetate or choline tracers should be preferred. In this review we provide an overview of the performance of choline and acetate PET for staging the primary and recurrent disease and lymph nodes in PCA, based on the literature of the last 10 years. Although predominantly choline has been used rather than acetate, both tracers performed in a similar manner in published studies. Choline as well as acetate have insufficient diagnostic accuracy for the staging of the primary tumour, due to a minimum detectable tumour size of 5 mm and inability to differentiate PCA from benign prostate hyperplasia, chronic prostatitis and high-grade intraepithelial neoplasia. Regarding lymph node staging, choline tracers have demonstrated a high specificity. Unfortunately, the sensitivity is only moderate. For staging recurrent disease, sensitivity depends on the level of serum PSA (PSA should be >2 ng/ml). This applies to both choline and acetate. However, despite these limitations, a significant number of patients with recurrent disease can benefit from PET imaging by a change in treatment planning. (orig.)

  10. Feasibility of TCP-based dose painting by numbers applied to a prostate case with 18F-choline PET imaging

    International Nuclear Information System (INIS)

    Dirscherl, Thomas; Bogner, Ludwig; Rickhey, Mark

    2012-01-01

    Introduction: A biologically adaptive radiation treatment method to maximize the TCP is shown. Functional imaging is used to acquire a heterogeneous dose prescription in terms of Dose Painting by Numbers and to create a patient-specific IMRT plan. Method and Materials: Adapted from a method for selective dose escalation under the guidance of spatial biology distribution, a model, which translates heterogeneously distributed radiobiological parameters into voxelwise dose prescriptions, was developed. At the example of a prostate case with 18 F-choline PET imaging, different sets of reported values for the parameters were examined concerning their resulting range of dose values. Furthermore, the influence of each parameter of the linear-quadratic model was investigated. A correlation between PET signal and proliferation as well as cell density was assumed. Using our in-house treatment planning software Direct Monte Carlo Optimization (DMCO), a treatment plan based on the obtained dose prescription was generated. Gafchromic EBT films were irradiated for evaluation. Results: When a TCP of 95% was aimed at, the maximal dose in a voxel of the prescription exceeded 100 Gy for most considered parameter sets. One of the parameter sets resulted in a dose range of 87.1 Gy to 99.3 Gy, yielding a TCP of 94.7%, and was investigated more closely. The TCP of the plan decreased to 73.5% after optimization based on that prescription. The dose difference histogram of optimized and prescribed dose revealed a mean of -1.64 Gy and a standard deviation of 4.02 Gy. Film verification showed a reasonable agreement of planned and delivered dose. Conclusion: If the distribution of radiobiological parameters within a tumor is known, this model can be used to create a dose-painting by numbers plan which maximizes the TCP. It could be shown, that such a heterogeneous dose distribution is technically feasible. (orig.)

  11. 3D-segmentation of the 18F-choline PET signal for target volume definition in radiation therapy of the prostate.

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    Ciernik, I Frank; Brown, Derek W; Schmid, Daniel; Hany, Thomas; Egli, Peter; Davis, J Bernard

    2007-02-01

    Volumetric assessment of PET signals becomes increasingly relevant for radiotherapy (RT) planning. Here, we investigate the utility of 18F-choline PET signals to serve as a structure for semi-automatic segmentation for forward treatment planning of prostate cancer. 18F-choline PET and CT scans of ten patients with histologically proven prostate cancer without extracapsular growth were acquired using a combined PET/CT scanner. Target volumes were manually delineated on CT images using standard software. Volumes were also obtained from 18F-choline PET images using an asymmetrical segmentation algorithm. PTVs were derived from CT 18F-choline PET based clinical target volumes (CTVs) by automatic expansion and comparative planning was performed. As a read-out for dose given to non-target structures, dose to the rectal wall was assessed. Planning target volumes (PTVs) derived from CT and 18F-choline PET yielded comparable results. Optimal matching of CT and 18F-choline PET derived volumes in the lateral and cranial-caudal directions was obtained using a background-subtracted signal thresholds of 23.0+/-2.6%. In antero-posterior direction, where adaptation compensating for rectal signal overflow was required, optimal matching was achieved with a threshold of 49.5+/-4.6%. 3D-conformal planning with CT or 18F-choline PET resulted in comparable doses to the rectal wall. Choline PET signals of the prostate provide adequate spatial information amendable to standardized asymmetrical region growing algorithms for PET-based target volume definition for external beam RT.

  12. PET imaging of hepatocellular carcinoma with {sup 18}F-fluoroethylcholine and {sup 11}C-choline

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    Kolthammer, Jeffrey A.; Tenley, Nathan [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); Corn, David J.; Wu, Chunying; Tian, Haibin; Wang, Yanming [University Hospitals Case Medical Center, Nuclear Medicine Division, Department of Radiology, Cleveland, OH (United States); Lee, Zhenghong [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); University Hospitals Case Medical Center, Nuclear Medicine Division, Department of Radiology, Cleveland, OH (United States)

    2011-07-15

    Choline-based radiotracers have been studied for PET imaging of hepatocellular carcinoma (HCC). Using an {sup 18}F-labeled choline analog, instead of the {sup 11}C-labeled native choline, would facilitate its widespread use in the clinic. In this study, PET with {sup 18}F-fluoroethylcholine (FEC) and {sup 11}C-choline (CHOL) were compared using an animal model of HCC. The effects of fasting on the performance of choline-based tracers were also investigated. A woodchuck model of HCC was used to compare the two tracers, which were administered and imaged in sequence during the same imaging session. Dynamic PET images were generated spanning 50 min starting from tracer injection. Time-activity curves and tracer contrast were calculated in liver regions with tracer accumulation, and the contrast at a late time-point with the two tracers, and between fasted and nonfasted states, were compared. Foci of HCC with increased uptake ranged in size from 1.0 to 1.6 cm, with mean tumor-to-background contrast of 1.3 with FEC and 1.5 with CHOL at 50 min after injection. The tracers show similar patterns of uptake immediately following administration, and both activities plateaued at 10 min after injection. No significant differences in uptake dynamics or final contrast were observed between the fasted and nonfasted states. PET imaging of HCC is possible with both CHOL and FEC. Fasting was not found to affect accumulation of either tracer. These results encourage further investigation into the clinical utility of FEC for HCC imaging. (orig.)

  13. Prospective head-to-head comparison of 11C-choline-PET/MR and 11C-choline-PET/CT for restaging of biochemical recurrent prostate cancer

    International Nuclear Information System (INIS)

    Eiber, Matthias; Rauscher, Isabel; Souvatzoglou, Michael; Schwaiger, Markus; Maurer, Tobias; Holzapfel, Konstantin; Beer, Ambros J.

    2017-01-01

    Whole-body integrated 11 C-choline PET/MR might provide advantages compared to 11 C-choline PET/CT for restaging of prostate cancer (PC) due to the high soft-tissue contrast and the use of multiparametric MRI, especially for detection of local recurrence and bone metastases. Ninety-four patients with recurrent PC underwent a single-injection/dual-imaging protocol with contrast-enhanced PET/CT followed by fully diagnostic PET/MR. Imaging datasets were read separately by two reader teams (team 1 and 2) assessing the presence of local recurrence, lymph node and bone metastases in predefined regions using a five-point scale. Detection rates were calculated. The diagnostic performance of PET/CT vs. PET/MR was compared using ROC analysis. Inter-observer and inter-modality variability, radiation exposure, and mean imaging time were evaluated. Clinical follow-up, imaging, and/or histopathology served as standard of reference (SOR). Seventy-five patients qualified for the final image analysis. A total of 188 regions were regarded as positive: local recurrence in 37 patients, 87 regions with lymph node metastases, and 64 regions with bone metastases. Mean detection rate between both readers teams for PET/MR was 84.7% compared to 77.3% for PET/CT (p > 0.05). Local recurrence was identified significantly more often in PET/MR compared to PET/CT by team 1. Lymph node and bone metastases were identified significantly more often in PET/CT compared to PET/MR by both teams. However, this difference was not present in the subgroup of patients with PSA values ≤2 ng/ml. Inter-modality and inter-observer agreement (K > 0.6) was moderate to substantial for nearly all categories. Mean reduction of radiation exposure for PET/MR compared to PET/CT was 79.7% (range, 72.6-86.2%). Mean imaging time for PET/CT was substantially lower (18.4 ± 0.7 min) compared to PET/MR (50.4 ± 7.9 min). 11 C-choline PET/MR is a robust imaging modality for restaging biochemical recurrent PC and

  14. Prostate cancer: concordance between "1"8F-choline PET and CT in biochemical relapse

    International Nuclear Information System (INIS)

    Herández Pinzón, J.; Ferrarotti, C.; Ferrari, L.; Larrañaga, N.; Gallo, J.C.; Mena, D.; Bastianello, M.

    2016-01-01

    Objective: To establish the concordance between 18-fluor choline positron emission tomography (PET) and computed tomography (CT) for re-staging patients with biochemical relapse of prostate cancer according to the TNM system. Materials and methods: The medical records of the Molecular Imaging Section were retrospectively reviewed. The TNM classification was established by us for each method, and the Kappa concordance statistic was used to classify the results according to the Landis and Koch proposal. Results: The PET-choline reported 19 (59.4%) patients N0 and 13 (40.6%) N1, while CT reported 28 (87.5%) N0 and 4 (12.5%) N1. In metastasis classification PET-choline established M0 in 17 (53.1%) patients, M1a in 1 (3.1%), M1b in 5 (15.6%), M1c in 1 (3.1%), M1a + M1b in 7 (21.9%), and M1b + M1c in 1 (3.1%). On the other hand, CT was M0 in 23 (71.9%) patients, M1a in 2 (6.25%), M1a + M1b in 2 (6.25%), and M1b + M1c in 5 (15.6%). The correlation between PET-choline and CT in the TNM lymph node and metastasis classifications was 71.88%, with a Kappa of 0.3455 (standard error 0.1336; P=.0049) and 62.5% with Kappa 0.3725 (standard error 0.0847; P=.0001), respectively. Discussion: Several studies have shown a high diagnostic accuracy of PET-choline detecting the spread of the disease compared to conventional methods. Conclusion: There is poor concordance for metastatic and lymph node classifications according to the TNM system between choline-PET and CT. (authors) [es

  15. Diagnostic performance of 11C-choline PET/CT and bone scintigraphy in the detection of bone metastases in patients with prostate cancer.

    Science.gov (United States)

    Kitajima, Kazuhiro; Fukushima, Kazuhito; Yamamoto, Shingo; Kato, Takashi; Odawara, Soichi; Takaki, Haruyuki; Fujiwara, Masayuki; Yamakado, Koichiro; Nakanishi, Yukako; Kanematsu, Akihiro; Nojima, Michio; Hirota, Shozo

    2017-08-01

    The aim of this study was to compare 11C-choline PET/CT and bone scintigraphy (BS) for detection of bone metastases in patients with prostate cancer. Twenty-one patients with histologically proven prostate cancer underwent 11C-choline PET/CT and BS before (n = 4) or after (n = 17) treatment. Patient-, region-, and lesion-based diagnostic performances of bone metastasis of both 11C-choline PET/CT and BS were evaluated using a five-point scale by two experienced readers. Bone metastases were present in 11 (52.4%) of 21 patients and 48 (32.7%) of 147 regions; 111 lesions were found to have bone metastases. Region-based analysis showed that the sensitivity, specificity, accuracy, and area under the receiver-operating-characteristic curves (AUC) of 11C-choline PET/CT were 97.9%, 99.0%, 98.6%, and 0.9989, respectively; those of BS were 72.9%, 99.0%, 90.5%, and 0.8386, respectively. Sensitivity, accuracy, and AUC significantly differed between the two methods (McNemar test, p = 0.0015, p = 0.0015, and p PET/CT detected 110/111 metastatic lesions (99.1%); BS detected 85 (76.6%) (p PET/BS were 100%/90.3% for the blastic type, 91.7%/8.3% for the lytic type, 100%/100% for the mixed type, and 100%/53.3% for the invisible type, respectively. Significant differences in blastic, lytic, and invisible types were observed between the two methods (p = 0.013, p = 0.0044, and p = 0.023, respectively). In conclusion, 11C-choline PET/CT had greater sensitivity and accuracy than BS for detection of bone involvement in patients with prostate cancer.

  16. Therapy assessment in prostate cancer using choline and PSMA PET/CT

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    Ceci, Francesco; Castellucci, Paolo; Fanti, Stefano [University of Bologna, Nuclear Medicine Unit, S. Orsola-Malpighi University Hospital, Bologna (Italy); Herrmann, Ken [University Hospital Essen, Department of Nuclear Medicine, Essen (Germany); University of California Los Angeles, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, CA (United States); Hadaschik, Boris [University Hospital Essen, Department of Urology, Essen (Germany)

    2017-08-15

    While PET with non-FDG tracers (mainly choline and Ga-PSMA) has commonly been used for restaging in men with biochemically recurrent prostate cancer, as well as for primary staging, it is only recently that a few preliminary studies have addressed the possible use of PET for monitoring the response to systemic therapy of metastatic disease, especially innovative treatments such as abiraterone and enzalutamide. This article aims to evaluate the role of PET imaging with different non-FDG radiotracers for assessment of therapy in advanced prostate cancer patients. (orig.)

  17. Automated synthesis of 11C-carfentanil with 11C-choline module and micro PET imaging

    International Nuclear Information System (INIS)

    Zhang Jinming; Zhang Xiaojun; Tian Jiahe; Xu Zhihong; Xiang Xiaohui

    2011-01-01

    A simple modified home-made 11 C-choline module enabled to rapid and efficient synthesis 11 C-carfentanil ( 11 C-CFN) as CNS μ-opioid receptor imaging agent. The synthesis of 11 C-CFN was completed in a yield of 14.8 GBq within 18 min from 11 C-CO 2 on the choline module. The methylation took place from 4-piperidinecarboxylic acid, 4-[(1-oxopropyl) phenylamino]-l-(2-phenylethyl), sodium salt as precursor in DMSO solution. The radio- chemical yields were over 80% (n=55, decay-corrected and based on 11 CH 3 -triflate). The radiochemical purity was over 95% and the specific activities was over 1.4 × 10 14 Bq/g. The biologic activity of 11 C-CFN was confirmed with Micro PET/CT imaging. (authors)

  18. PET and PET/CT with radiolabeled choline in prostate cancer: a critical reappraisal of 20 years of clinical studies

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    Giovacchini, Giampiero; Giovannini, Elisabetta; Leoncini, Rossella; Riondato, Mattia; Ciarmiello, Andrea [S. Andrea Hospital, Nuclear Medicine Department, La Spezia (Italy)

    2017-09-15

    We here aim to provide a comprehensive and critical review of the literature concerning the clinical applications of positron emission tomography/computed tomography (PET/CT) with radiolabeled choline in patients with prostate cancer (PCa). We will initially briefly summarize the historical context that brought to the synthesis of [{sup 11}C]choline, which occurred exactly 20 years ago. We have arbitrarily grouped the clinical studies in three different periods, according to the year in which they were published and according to their relation with their applications in urology, radiotherapy and oncology. Studies at initial staging and, more extensively, studies in patients with biochemical failure, as well as factors predicting positive PET/CT will be reviewed. The capability of PET/CT with radiolabeled choline to provide prognostic information on PCa-specific survival will also be examined. The last sections will be devoted to the use of radiolabeled choline for monitoring the response to androgen deprivation therapy, radiotherapy, and chemotherapy. The accuracy and the limits of the technique will be discussed according to the information available from standard validation processes, including biopsy or histology. The clinical impact of the technique will be discussed on the basis of changes induced in the management of patients and in the evaluation of the response to therapy. Current indications to PET/CT, as officially endorsed by guidelines, or as routinely performed in the clinical practice will be illustrated. Emphasis will be made on methodological factors that might have influenced the results of the studies or their interpretation. Finally, we will briefly highlight the potential role of positron emission tomography/magnetic resonance and of new radiotracers for PCa imaging. (orig.)

  19. An Incidental Renal Oncocytoma: 18F-Choline PET/MRI

    Directory of Open Access Journals (Sweden)

    Andrew Mallia

    2016-04-01

    Full Text Available PET/MRI is a new hybrid imaging modality and has the potential to become a powerful imaging tool. It is currently one of the most active areas of research in diagnostic imaging. The characterisation of an incidental renal lesion can be difficult. In particular, the differentiation of an oncocytoma from other solid renal lesions such as renal cell carcinoma (RCC represents a diagnostic challenge. We describe the detection of an incidental renal oncocytoma in a 79-year gentleman who underwent a re-staging 18F-Choline PET/MRI following a rise in PSA values (4.07, nadir 1.3.

  20. Comparison of C-11-choline and F-18-FDG PET in primary diagnosis and staging of patients with thoracic cancer

    NARCIS (Netherlands)

    Pieterman, RM; Que, TH; Elsinga, PH; Pruim, J; van Putten, JWG; Willemsen, ATM; Vaalburg, W; Groen, HJM

    PET with F-18-FDG is used for detection and staging of thoracic cancer; however, more specific PET radiopharmaceuticals would be welcome. C-11-labeled choline (CHOL) is a new radiopharmaceutical potentially useful for tumor imaging, since it is incorporated into cell membranes as

  1. Evaluation of 11C-choline PET/CT for primary diagnosis and staging of urothelial carcinoma of the upper urinary tract: a pilot study

    International Nuclear Information System (INIS)

    Sassa, Naoto; Yamamoto, Tokunori; Gotoh, Momokazu; Kato, Katsuhiko; Ikeda, Mitsuru; Shimamoto, Kazuhiro; Yamamoto, Seiichi; Abe, Shinji; Iwano, Shingo; Ito, Shinji; Naganawa, Shinji

    2014-01-01

    We conducted a pilot study to prospectively evaluate the efficacy of PET/CT with 11 C-choline (choline PET/CT) for primary diagnosis and staging of urothelial carcinoma of the upper urinary tract (UUT-UC). Enrolled in this study were 16 patients (9 men, 7 women; age range 51 - 83 years, mean ± SD 69 ± 10.8 years) with suspected UUT-UC. The patients were examined by choline PET/CT, and 13 underwent laparoscopic nephroureterectomy and partial cystectomy. Lymphadenectomy and chemotherapy were also performed as necessary in some of the patients. Of the 16 patients, 12 were confirmed to have UUT-UC (7 renal pelvis carcinoma and 5 ureteral carcinoma), 1 had malignant lymphoma (ureter), 1 had IgG4-related disease (ureter), and 2 had other benign diseases (ureter). Of the 16 study patients, 13 showed definite choline uptake in urothelial lesions, and of these, 11 had UUT-UC, 1 had malignant lymphoma, and 1 had IgG4-related disease. Three patients without choline uptake comprised one with UUT-UC and two with benign diseases. Of the 12 patients with UUT-UC, 3 had distant metastases, 2 had metastases only in the regional lymph nodes, and 7 had no metastases. Distant metastases and metastases in the regional lymph nodes showed definite choline uptake. The outcome in patients with UUT-UC, which was evaluated 592 - 1,530 days after surgery, corresponded to the patient classification based on the presence or absence of metastases and locoregional or distant metastases. Choline uptake determined as SUVmax 10 min after administration was significantly higher than at 20 min in metastatic tumours of UUT-UC (p < 0.05), whereas there was no statistically significant difference between the SUVmax values at 10 and those at 20 min in primary tumours of UUT-UC. This study suggests that choline PET/CT is a promising tool for the primary diagnosis and staging of UUT-UC. (orig.)

  2. Prostate cancer: a comparative study of {sup 11}C-choline PET and MR imaging combined with proton MR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Takako; Lee, Jin; Takahashi, Nobukazu; Oka, Takashi; Shizukuishi, Kazuya; Inoue, Tomio [Yokohama City University School of Medicine, Department of Radiology, Yokohama (Japan); Uemura, Hiroji; Kubota, Yoshinobu [Yokohama City University School of Medicine, Department of Urology, Kanagawa (Japan); Sasaki, Takeshi [Yokohama City University School of Medicine, Department of Pathology, Kanagawa (Japan); Endou, Hisashi [Yokohama City University School of Medicine, Department of Pharmacy, Kanagawa (Japan)

    2005-07-01

    Prostate cancer is difficult to visualise in its early stages using current imaging technology. The present study aimed to clarify the utility of {sup 11}C-choline PET for localising and evaluating cancer lesions in patients with prostate cancer by conducting a prospective comparison with magnetic resonance (MR) imaging combined with proton MR spectroscopy. PET and MR imaging combined with proton MR spectroscopy were performed in 20 patients with prostate cancer. Correlations among the metabolite ratio of choline + creatine to citrate (Cho+Cr/Ci) on MR spectroscopy, serum PSA and maximum standardised uptake value (SUV{sub max}) of {sup 11}C-choline were assessed. The location of the primary lesion was assessed by the site of SUV{sub max} and the laterality of the highest Cho+Cr/Ci ratio and confirmed by examination of surgical pathology specimens (n=16). PET exhibited a diagnostic sensitivity of 100% (20/20) for primary lesions, while the sensitivities of MR imaging and MR spectroscopy were 60% (12/20) and 65% (13/20), respectively. Weak linear correlations were observed between SUV{sub max} and serum PSA (r=0.52, p<0.05), and between SUV{sub max} and Cho+Cr/Ci ratio (r=0.49, p<0.05). Regarding the localisation of main primary lesions, PET results agreed with pathological findings in 13 patients (81%) ({kappa}=0.59), while MR spectroscopy results were in accordance with pathological findings in eight patients (50%) ({kappa}=0.11). This preliminary study suggests that {sup 11}C-choline PET may provide more accurate information regarding the localisation of main primary prostate cancer lesions than MR imaging/MR spectroscopy. A further clinical study of {sup 11}C-choline PET in a large number of patients suspected of prostate cancer will be necessary to determine the clinical utility of {sup 11}C-choline PET in patients who clinically require biopsy. (orig.)

  3. Carbon-11 choline or FDG-PET for staging of oesophageal cancer?

    International Nuclear Information System (INIS)

    Jager, P.L.; Que, T.H.; Vaalburg, W.; Pruim, J.; Elsinga, P.; Plukker, J.T.

    2001-01-01

    We investigated the feasibility of using carbon-11 choline (CHOL) positron emission tomography (PET) for the staging of oesophageal cancer, in comparison with fluorine-18 fluorodeoxyglucose (FDG) PET, using histopathological findings as the gold standard. Eighteen patients were studied: 16 patients with cancer of the oesophagus or gastro-oesophageal junction and two with in situ carcinoma/high-grade dysplasia. PET imaging was performed 5 min (CHOL) or 90 min (FDG) after injection of 370 MBq of the tracer. PET images were analysed by two independent and blinded physicians using visual and standardised uptake value (SUV) analysis. PET results were compared with surgical and histopathological findings. FDG-PET was able to detect all (100%) of the 16 malignant primary lesions, while CHOL-PET detected 73%. In situ carcinoma (n=1) and high-grade dysplasia (n=1) were not visualised with either tracer. Diffuse uptake of the tracers was noted in areas of Barrett's oesophagitis. Twelve patients had locoregional metastases (N1) that were not detected with either FDG or CHOL. Six patients had additional distant nodal (M1a) metastases; four of six (66%) were visualised by FDG, and three of five (60%) by CHOL-PET. On a lesion basis, FDG-PET detected 10/12 non-regional metastases (sensitivity 83%), while CHOL-PET detected 5/12 (sensitivity 42%). Haematogenous distant metastases (M1b) were positive on FDG-PET in three of four patients, and on CHOL-PET in two of four. SUV values were significantly higher for FDG (FDG 6.6±3.5, CHOL 5.5±2.5, P=0.04). CHOL-PET is able to visualise oesophageal carcinoma and its metastases, but appears to be inferior to FDG-PET. Presumably this is the result of lower tumoural uptake and considerable non-specific uptake of CHOL in liver, stomach wall, pancreas and small intestine. Further studies are needed to confirm these data. (orig.)

  4. Carbon-11 choline or FDG-PET for staging of oesophageal cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Jager, P.L.; Que, T.H.; Vaalburg, W.; Pruim, J.; Elsinga, P. [PET Centre, Groningen Univ. Hospital (Netherlands); Plukker, J.T. [Dept. of Surgical Oncology, Groningen University Hospital (Netherlands)

    2001-12-01

    We investigated the feasibility of using carbon-11 choline (CHOL) positron emission tomography (PET) for the staging of oesophageal cancer, in comparison with fluorine-18 fluorodeoxyglucose (FDG) PET, using histopathological findings as the gold standard. Eighteen patients were studied: 16 patients with cancer of the oesophagus or gastro-oesophageal junction and two with in situ carcinoma/high-grade dysplasia. PET imaging was performed 5 min (CHOL) or 90 min (FDG) after injection of 370 MBq of the tracer. PET images were analysed by two independent and blinded physicians using visual and standardised uptake value (SUV) analysis. PET results were compared with surgical and histopathological findings. FDG-PET was able to detect all (100%) of the 16 malignant primary lesions, while CHOL-PET detected 73%. In situ carcinoma (n=1) and high-grade dysplasia (n=1) were not visualised with either tracer. Diffuse uptake of the tracers was noted in areas of Barrett's oesophagitis. Twelve patients had locoregional metastases (N1) that were not detected with either FDG or CHOL. Six patients had additional distant nodal (M1a) metastases; four of six (66%) were visualised by FDG, and three of five (60%) by CHOL-PET. On a lesion basis, FDG-PET detected 10/12 non-regional metastases (sensitivity 83%), while CHOL-PET detected 5/12 (sensitivity 42%). Haematogenous distant metastases (M1b) were positive on FDG-PET in three of four patients, and on CHOL-PET in two of four. SUV values were significantly higher for FDG (FDG 6.6{+-}3.5, CHOL 5.5{+-}2.5, P=0.04). CHOL-PET is able to visualise oesophageal carcinoma and its metastases, but appears to be inferior to FDG-PET. Presumably this is the result of lower tumoural uptake and considerable non-specific uptake of CHOL in liver, stomach wall, pancreas and small intestine. Further studies are needed to confirm these data. (orig.)

  5. Visualisation of bladder cancer using 11C-choline PET: first clinical experience

    International Nuclear Information System (INIS)

    De Jong, Igle J.; Pruim, Jan; Elsinga, Philip H.; Jongen, Maud M.G.J.; Vaalburg, Willem; Mensink, Han J.A.

    2002-01-01

    Fluorine-18 fluorodeoxyglucose (FDG), the most widely used radiopharmaceutical in positron emission tomography (PET) for oncological purposes, is unsuitable for imaging of bladder cancer owing to high excretion into the urine. More specific PET radiopharmaceuticals which are not excreted into urine would be welcome. Carbon-11 labelled choline (CHOL) is a new radiopharmaceutical potentially useful for tumour imaging and is not excreted into the urine. We prospectively studied the visualisation of bladder cancer using CHOL PET. Eighteen patients with bladder cancer and five healthy volunteers were included. Bladder cancer was first diagnosed by transurethral resection or by biopsy of the tumour. Next, PET images were performed before surgical treatment by cystectomy. The histopathological findings after cystectomy were used as the gold standard. PET images were performed on either an ECAT 951/31 or an ECAT Exact HR+ system. Attenuation-corrected PET images were obtained after injection of 400 MBq CHOL. PET images were analysed by two independent physicians using visual analysis and calculation of the standardised uptake value (SUV). In the normal bladder wall, the uptake of CHOL was low, and the bladder margin was only outlined by minimal urinary radioactivity, if present. In ten patients the tumour was detected correctly by CHOL PET, with an SUV of 4.7±3.6 (mean±SD). One false positive CHOL PET scan was seen in a patient with an indwelling catheter for 2 weeks prior to the PET scan. In two patients, lymph node metastases were detected by CHOL PET. A micrometastasis <5 mm was not visualised with CHOL PET. In seven patients, no residual tumour was found after surgery. In six of seven patients CHOL PET imaging was negative. In situ carcinoma, dysplasia and a non-invasive urothelial tumour (pTa) remained undetected in three of these six patients. Minimal to no urinary tract radioactivity was seen in 22/23 subjects. Non-specific uptake of CHOL was observed in the small

  6. Value of bimodal (18)F-choline-PET/MRI and trimodal (18)F-choline-PET/MRI/TRUS for the assessment of prostate cancer recurrence after radiation therapy and radical prostatectomy.

    Science.gov (United States)

    Paparo, Francesco; Piccardo, Arnoldo; Bacigalupo, Lorenzo; Romagnoli, Andrea; Piccazzo, Riccardo; Monticone, Michela; Cevasco, Luca; Campodonico, Fabio; Conzi, Giuseppe Maria; Carmignani, Giorgio; Rollandi, Gian Andrea

    2015-08-01

    Between 27% and 53% of all patients who undergo radical prostatectomy (RP) or radiation therapy (RT) as the first-line treatment of prostate cancer (PCa) develop a biochemical recurrence. Imaging plays a pivotal role in restaging by helping to distinguish between local relapse and metastatic disease (i.e., lymph-node and skeletal metastases). At present, the most promising tools for assessing PCa patients with biochemical recurrence are multiparametric magnetic resonance imaging (mpMRI) and positron emission tomography (PET)/computed tomography (CT) with radio-labeled choline derivatives. The main advantage of mpMRI is its high diagnostic accuracy in detecting local recurrence, while choline-PET/CT is able to identify lymph-node metastases when they are not suspicious on morphological imaging. The most recent advances in the field of fusion imaging have shown that multimodal co-registration, synchronized navigation, and combined interpretation are more valuable than the individual; separate assessment offered by different diagnostic techniques. The objective of the present essay was to describe the value of bimodal choline-PET/mpMRI fusion imaging and trimodal choline-PET/mpMRI/transrectal ultrasound (TRUS) in the assessment of PCa recurrence after RP and RT. Bimodal choline-PET/mpMRI fusion imaging allows morphological, functional, and metabolic information to be combined, thereby overcoming the limitations of each separate imaging modality. In addition, trimodal real-time choline-PET/mpMRI/TRUS fusion imaging may be useful for the planning and real-time guidance of biopsy procedures in order to obtain histological confirmation of the local recurrence.

  7. The detection rate of [11C]Choline-PET/CT depends on the serum PSA-value in patients with biochemical recurrence of prostate cancer

    International Nuclear Information System (INIS)

    Krause, B.J.; Souvatzoglou, M.; Tuncel, M.; Herrmann, K.; Buck, A.K.; Praus, C.; Schwaiger, M.; Schuster, T.; Geinitz, H.; Treiber, U.

    2008-01-01

    An increase of the serum PSA-level is a sensitive in vitro marker for recurrent prostate cancer. However, it remains difficult to differentiate between local, regional or distant recurrent disease. The aim of this study was to assess the relationship between the detection rate of [ 11 C]Choline-PET/CT and the serum PSA-level in patients with a biochemical recurrence of prostate cancer with the view towards localisation of recurrent disease. Sixty-three patients (mean age, 68.8 ± 6.9; range, 45-83 years) with biochemical recurrence after primary therapy for prostate cancer were included in the analysis. Mean PSA-levels were 5.9 ± 9.7 ng/ml (range, 0.2-39 ng/ml; median, 2.15). Of the 63 patients, 17 were under anti-androgen therapy at the time of [ 11 C]Choline PET/CT. Patients underwent a [ 11 C]Choline-PET/CT study after injection of 656 ± 119 MBq [ 11 C]Choline on a Sensation 16 Biograph PET/CT scanner. Of the 63 patients, 35 (56%) showed a pathological [ 11 C]Choline uptake. The detection rate of [ 11 C]Choline-PET/CT showed a relationship with the serum PSA-level: The detection rate was 36% for a PSA-value 11 C]Choline-PET/CT (p = 0.374). As an important result our study shows that even for PSA-values 11 C]Choline-PET/CT is 36%. Furthermore, the detection rate of [ 11 C]Choline-PET/CT shows a positive relationship with serum PSA-levels in patients with biochemical recurrence of prostate cancer after primary therapy. Therefore, in these patients, [ 11 C]Choline PET/CT allows not only to diagnose but also to localise recurrent disease with implications on disease management (localised vs systemic therapy). (orig.)

  8. Diagnostic value of combining {sup 11}C-choline and {sup 18}F-FDG PET/CT in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Castilla-Lievre, Maria-Angela [University Department Hepatinov, Assistance-Publique Hopitaux de Paris, Department of Nuclear Medicine, Hopital Antoine Beclere, Clamart (France); IMIV - UMR 1023 Inserm/CEA/Universite Paris Sud - ERL 9218 CNRS, Orsay (France); Franco, Dominique [Universite Paris-Sud, Department of Surgery, Hopital Antoine Beclere, University Department Hepatinov, Assistance-Publique Hopitaux de Paris, Clamart (France); Gervais, Philippe; Kuhnast, Bertrand; Desarnaud, Serge; Helal, Badia-Ourkia [IMIV - UMR 1023 Inserm/CEA/Universite Paris Sud - ERL 9218 CNRS, Orsay (France); CEA, DSV, I2BM, Service Hospitalier Frederic Joliot, Orsay (France); Agostini, Helene [University Department Hepatinov, Assistance-Publique Hopitaux de Paris, Clinical Research Unit of Hopitaux universitaires Paris-Sud, Hopital Kremlin Bicetre (France); Marthey, Lysiane [Universite Paris-Sud, Department of Gastroenterology, Hopital Antoine Beclere, University Department Hepatinov, Assistance-Publique Hopitaux de Paris, Clamart (France)

    2016-05-15

    In this prospective study, our goal was to emphasize the diagnostic value of combining {sup 11}C-choline and {sup 18}F-FDG PET/CT for hepatocellular carcinoma (HCC) in patients with chronic liver disease. Thirty-three consecutive patients were enrolled. All patients were suspected to have HCC based on CT and/or MRI imaging. A final diagnosis was obtained by histopathological examination or by imaging alone according to American Association for the Study of Liver Disease criteria. All patients underwent PET/CT with both tracers within a median of 5 days. All lesions showing higher tracer uptake than normal liver were considered positive for HCC. We examined how tracer uptake was related to biological (serum α-fetoprotein levels) and pathological (differentiation status, peritumoral capsule and vascular invasion) prognostic markers of HCC, as well as clinical observations at 6 months (recurrence and death). Twenty-eight HCC, four cholangiocarcinomas and one adenoma were diagnosed. In the HCC patients, the sensitivity of {sup 11}C-choline, {sup 18}F-FDG and combined {sup 11}C-choline and {sup 18}F-FDG PET/CT for the detection of HCC was 75 %, 36 % and 93 %, respectively. Serum α-fetoprotein levels >200 ng/ml were more frequent among patients with {sup 18}F-FDG-positive lesions than those with {sup 18}F-FDG-negative lesions (p < 0.05). Early recurrence (n=2) or early death (n=5) occurred more frequently in patients with {sup 18}F-FDG-positive lesions than in those with {sup 18}F-FDG-negative lesions (p < 0.05). The combined use of {sup 11}C-choline and {sup 18}F-FDG PET/CT detected HCC with high sensitivity. This approach appears to be of potential prognostic value and may facilitate the selection of patients for surgical resection or liver transplantation. (orig.)

  9. 18F-FDG versus 11C-choline PET/CT for the imaging of advanced head and neck cancer after combined intra-arterial chemotherapy and radiotherapy: the time period during which PET/CT can reliably detect non-recurrence

    International Nuclear Information System (INIS)

    Ito, Kimiteru; Matsuda, Hiroshi; Yokoyama, Jyunkichi; Kubota, Kazuo; Morooka, Miyako; Shiibashi, Michio

    2010-01-01

    The purpose of this prospective study was to evaluate the usefulness of 18 F-fluorodeoxyglucose (FDG) and 11 C-choline positron emission tomography (PET)/computed tomography (CT) for detecting recurrences of advanced head and neck cancer after combined intra-arterial chemotherapy and radiotherapy. Additionally, we surveyed the time period during which an effective negative predictive value could be maintained after the first follow-up PET/CT examination and estimated the optimal timing of a second PET/CT examination for detecting late recurrences. Fifty-three subjects (36 men and 17 women; mean age: 59.4±11.5 years) with advanced head and neck squamous cell carcinoma were recruited. Post-treatment 18 F-FDG PET/CT and 11 C-choline examinations were performed in all patients between 8 and 12 weeks after combined intra-arterial chemotherapy and radiotherapy. The PET/CT images were evaluated using a patient-based analysis and a lesion-based analysis. All of the patients were prospectively followed for at least 9 months after the post-treatment PET/CT examination, with surveillance using conventional images (including CT and/or MRI) and a physical examination performed every 3 months. Recurrences, as determined using the patient-based analysis, were eventually confirmed in 18, 6 and 5 patients at 3, 4-6 and 7-9 months after the post-treatment PET/CT examination, respectively. The sensitivity and specificity of the 18F-FDG PET/CT and the 11C-choline PET/CT examinations to predict recurrence within 3 months were higher (FDG: 89 and 91%; choline: 83 and 80%, respectively) than for recurrence detection 6 months (FDG: 67 and 90%; choline: 62 and 76%, respectively) and 9 months later (FDG: 59 and 92%; choline: 55 and 75%, respectively). The lesion-based analysis showed that the maximum standardized uptake value of 18 F-FDG and 11 C-choline in the recurrent lesions were correlated with each other, compared with their relation in scar tissues (R 2 = 0.492 and 0

  10. Prospective evaluation of [{sup 11}C]Choline PET/CT in therapy response assessment of standardized docetaxel first-line chemotherapy in patients with advanced castration refractory prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzenboeck, Sarah M.; Krause, Bernd J. [Technical University of Munich, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Rostock University Medical Centre, Department of Nuclear Medicine, Rostock (Germany); Eiber, Matthias; Schwaiger, Markus [Technical University of Munich, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Kundt, Guenther [Rostock University Medical Centre, Department of Biostatistics and Informatics, Rostock (Germany); Retz, Margitta; Treiber, Uwe; Nawroth, Roman; Gschwend, Juergen E.; Thalgott, Mark [Technical University of Munich, Department of Urology, Klinikum rechts der Isar, Munich (Germany); Sakretz, Monique; Kurth, Jens [Rostock University Medical Centre, Department of Nuclear Medicine, Rostock (Germany); Rummeny, Ernst J. [Technical University of Munich, Institute of Radiology, Klinikum rechts der Isar, Munich (Germany)

    2016-11-15

    The aim of this study was to prospectively evaluate the value of [{sup 11}C] Choline PET/CT in monitoring early and late response to a standardized first-line docetaxel chemotherapy in castration refractory prostate cancer (mCRPC) patients. Thirty-two patients were referred for [{sup 11}C] Choline PET/CT before the start of docetaxel chemotherapy, after one and ten chemotherapy cycles (or - in case of discontinuation - after the last administered cycle) for therapy response assessment. [{sup 11}C] Choline uptake (SUV{sub max}, SUV{sub mean}), CT derived Houndsfield units (HU{sub max}, HU{sub mean}), and volume of bone, lung, and nodal metastases and local recurrence were measured semi-automatically at these timepoints. Change in SUV{sub max}, SUV{sub mean}, HU{sub max}, HU{sub mean,} and volume was assessed between PET 2 and 1 (early response assessment, ERA) and PET 3 and 1 (late response assessment, LRA) on a patient and lesion basis. Results of PET/CT were compared to clinically used RECIST 1.1 and clinical criteria based therapy response assessment including PSA for defining progressive disease (PD) and non-progressive disease (nPD), respectively. Relationships between changes of SUV{sub max} and SUV{sub mean} (early and late) and changes of PSA{sub early} and PSA{sub late} were evaluated. Prognostic value of initial SUV{sub max} and SUV{sub mean} was assessed. Statistical analyses were performed using SPSS. In the patient-based ERA and LRA there were no statistically significant differences in change of choline uptake, HU, and volume between PD and nPD applying RECIST or clinical response criteria. In the lesion-based ERA, decrease in choline uptake of bone metastases was even higher in PD (applying RECIST criteria), whereas in LRA the decrease was higher in nPD (applying clinical criteria). There were only significant correlations between change in choline uptake and PSA in ERA in PD, in LRA no significant correlations were discovered. Initial SUV{sub max

  11. Prospective evaluation of [11C]Choline PET/CT in therapy response assessment of standardized docetaxel first-line chemotherapy in patients with advanced castration refractory prostate cancer

    International Nuclear Information System (INIS)

    Schwarzenboeck, Sarah M.; Krause, Bernd J.; Eiber, Matthias; Schwaiger, Markus; Kundt, Guenther; Retz, Margitta; Treiber, Uwe; Nawroth, Roman; Gschwend, Juergen E.; Thalgott, Mark; Sakretz, Monique; Kurth, Jens; Rummeny, Ernst J.

    2016-01-01

    The aim of this study was to prospectively evaluate the value of [ 11 C] Choline PET/CT in monitoring early and late response to a standardized first-line docetaxel chemotherapy in castration refractory prostate cancer (mCRPC) patients. Thirty-two patients were referred for [ 11 C] Choline PET/CT before the start of docetaxel chemotherapy, after one and ten chemotherapy cycles (or - in case of discontinuation - after the last administered cycle) for therapy response assessment. [ 11 C] Choline uptake (SUV max , SUV mean ), CT derived Houndsfield units (HU max , HU mean ), and volume of bone, lung, and nodal metastases and local recurrence were measured semi-automatically at these timepoints. Change in SUV max , SUV mean , HU max , HU mean, and volume was assessed between PET 2 and 1 (early response assessment, ERA) and PET 3 and 1 (late response assessment, LRA) on a patient and lesion basis. Results of PET/CT were compared to clinically used RECIST 1.1 and clinical criteria based therapy response assessment including PSA for defining progressive disease (PD) and non-progressive disease (nPD), respectively. Relationships between changes of SUV max and SUV mean (early and late) and changes of PSA early and PSA late were evaluated. Prognostic value of initial SUV max and SUV mean was assessed. Statistical analyses were performed using SPSS. In the patient-based ERA and LRA there were no statistically significant differences in change of choline uptake, HU, and volume between PD and nPD applying RECIST or clinical response criteria. In the lesion-based ERA, decrease in choline uptake of bone metastases was even higher in PD (applying RECIST criteria), whereas in LRA the decrease was higher in nPD (applying clinical criteria). There were only significant correlations between change in choline uptake and PSA in ERA in PD, in LRA no significant correlations were discovered. Initial SUV max and SUV mean were statistically significantly higher in nPD (applying clinical

  12. Application of 11C-choline PET/CT imaging for differentiating malignant from benign prostate lesions

    International Nuclear Information System (INIS)

    Li Xin; Wang Muwen; Liu Qingwei; Zhu Renjuan; Liu Lihui; Yuan Xianshun; Yao Shuzhan; Liu Songtao

    2006-01-01

    Objective: To investigate the potential of 11 C-choline PET/CT imaging for differentiating prostate cancer from benign prostate hyperplasia. Methods: A total of 45 patients with prostate lesions under- went 11 C-choline PET/CT imaging before transrectal needle biopsy. PET/CT imaging was performed 5 min after injection of 7.4 MBq/kg 11 C-choline in supine position over lower abdomen (3 min per bed with 2 beds), including the pelvis, and the whole body with 6 beds when necessary. After attenuation correction and iterative reconstruction, PET data were analyzed semi-quantitatively by measuring maximum standardized uptake values (SUV max ) in prostate lesions (P, target) and the muscles (M, non-target) and then P/M ratios were calculated. Also visual analysis was performed in different transverse, sagittal views and slices as well as three-dimensional images. Results: Eighteen prostate cancer and 27 benign prostate hyperplasia [and(or) chronic prostatitis] were all confirmed by pathology. The mean P/M ratio of prostate cancer was 4.02± 1.88, while in benign lesions was 1.87±1.21. The statistical differences of P/M ratios between them were significant (t=2.07, P 11 C-choline PET/CT imaging were 88.89%, 88.89% and 92.31% respectively. Conclusions: 11 C-choline PET/CT imaging is a valuable non-invasive technology in the diagnosis of pros- tate cancer. The P/M ratio can differentiate prostate cancer from benign lesions better than SUV. (authors)

  13. Histopathological correlation of 11C-choline PET scans for target volume definition in radical prostate radiotherapy

    International Nuclear Information System (INIS)

    Chang, Joe H.; Joon, Daryl Lim; Lee, Sze Ting; Gong, Sylvia J.; Scott, Andrew M.; Davis, Ian D.; Clouston, David; Bolton, Damien; Hamilton, Christopher S.; Khoo, Vincent

    2011-01-01

    Background and purpose: To evaluate the accuracy of 11 C-choline PET scans in defining dominant intraprostatic lesions (DILs) for radiotherapy target volume definition. Material and methods: Eight men with prostate cancer who had 11 C-choline PET scans prior to radical prostatectomy were studied. Several methods were used to contour the DIL on the PET scans: visual, PET Edge, Region Grow, absolute standardised uptake value (SUV) thresholds and percentage of maximum SUV thresholds. Prostatectomy specimens were sliced in the transverse plane and DILs were delineated on these by a pathologist. These were then compared with the PET scans. The accuracy of correlation was assessed by the Dice similarity coefficient (DSC) and the Youden index. Results: The contouring method resulting in both the highest DSC and the highest Youden index was 60% of the maximum SUV (SUV 60% ), with values of 0.64 and 0.51, respectively. However SUV 60% was not statistically significantly better than all of the other methods by either measure. Conclusions: Although not statistically significant, SUV 60% resulted in the best correlation between 11 C-choline PET and pathology amongst all the methods studied. The degree of correlation shown here is consistent with previous studies that have justified using imaging for DIL radiotherapy target volume definition.

  14. {sup 11}C-Choline PET/CT in castration-resistant prostate cancer patients treated with docetaxel

    Energy Technology Data Exchange (ETDEWEB)

    Ceci, Francesco [University of Bologna, Service of Nuclear Medicine, S. Orsola-Malpighi Hospital, Bologna (Italy); Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, UO Medicina Nucleare PAD. 30, Bologna (Italy); Castellucci, Paolo; Graziani, Tiziano; Renzi, Riccardo; Fanti, Stefano [University of Bologna, Service of Nuclear Medicine, S. Orsola-Malpighi Hospital, Bologna (Italy); Schiavina, Riccardo; Borghesi, Marco; Brunocilla, Eugenio [University of Bologna, Department of Urology, S. Orsola-Malpighi Hospital, Bologna (Italy); Di Tullio, Piergiorgio; Ardizzoni, Andrea [University of Bologna, Department of Oncology, S. Orsola-Malpighi Hospital, Bologna (Italy)

    2016-01-15

    To investigate the role of {sup 11}C-choline PET/CT for evaluating the response to treatment in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with docetaxel in comparison with PSA response. Inclusion criteria were (a) proven mCRPC, (b) docetaxel as first line of chemotherapy (docetaxel 75 mg/m{sup 2} + prednisone 5 mg), and (c) {sup 11}C-choline PET/CT and PSA values assessed before and after docetaxel administration. A total of 61 patients were retrospectively enrolled (mean age 68.9 years, range 57 - 84 years). {sup 11}C-Choline PET/CT was performed at baseline before docetaxel treatment (PET1) and after the end of treatment (PET2). PSA values were measured before treatment (PSA1) and after treatment (PSA2). PET2 was reported as complete response (CR), partial response (PR) or stable disease (SD). Progressive disease (PD) was considered if a new lesion was seen. PSA trend was calculated from the change in absolute values between PSA1 and PSA2. A decrease of ≥50 % between PSA1 and PSA2 was considered a PSA response. Clinical, radiological and laboratory follow-up ranged from 6 to 53 months (mean 13.5 months). Of the 61 patients, 40 (65.5 %) showed PD on PET2, 13 (21.3 %) showed SD, 2 (3.4 %) showed PR, and 6 (9.8 %) showed CR. An increasing PSA trend was seen in 29 patients (47.5 %) and a decreasing PSA trend in 32 patients (52.5 %). A PSA response of ≥50 % was seen in 25 patients (41 %). Radiological PD was seen in 23 of the 29 patients (79.3 %) with an increasing PSA trend, in 16 of the 32 patients (50 %) with a decreasing PSA trend, and in 11 of the 25 patients (44 %) with a PSA response of ≥50 %. In the multivariate statistical analysis, the presence of more than ten bone lesions detected on PET1 was significantly associated with an increased probability of PD on PET2. No association was observed between PSA level and PD on PET2. Our results suggest that an increasing PSA trend measured after docetaxel treatment could be

  15. [11C]Choline PET/CT predicts survival in hormone-naive prostate cancer patients with biochemical failure after radical prostatectomy

    International Nuclear Information System (INIS)

    Giovacchini, Giampiero; Incerti, Elena; Mapelli, Paola; Gianolli, Luigi; Picchio, Maria; Kirienko, Margarita; Briganti, Alberto; Gandaglia, Giorgio; Montorsi, Francesco

    2015-01-01

    Over the last decade, PET/CT with radiolabelled choline has been shown to be useful for restaging patients with prostate cancer (PCa) who develop biochemical failure. The limitations of most clinical studies have been poor validation of [ 11 C]choline PET/CT-positive findings and lack of survival analysis. The aim of this study was to assess whether [ 11 C]choline PET/CT can predict survival in hormone-naive PCa patients with biochemical failure. This retrospective study included 302 hormone-naive PCa patients treated with radical prostatectomy who underwent [ 11 C]choline PET/CT from 1 December 2004 to 31 July 2007 because of biochemical failure (prostate-specific antigen, PSA, >0.2 ng/mL). Median PSA was 1.02 ng/mL. PCa-specific survival was estimated using Kaplan-Meier curves. Cox regression analysis was used to evaluate the association between clinicopathological variables and PCa-specific survival. The coefficients of the covariates included in the Cox regression analysis were used to develop a novel nomogram. Median follow-up was 7.2 years (1.4 - 18.9 years). [ 11 C]Choline PET/CT was positive in 101 of 302 patients (33 %). Median PCa-specific survival after prostatectomy was 14.9 years (95 % CI 9.7 - 20.1 years) in patients with positive [ 11 C]choline PET/CT. Median survival was not achieved in patients with negative [ 11 C]choline PET/CT. The 15-year PCa-specific survival probability was 42.4 % (95 % CI 31.7 - 53.1 %) in patients with positive [ 11 C]choline PET/CT and 95.5 % (95 % CI 93.5 - 97.5 %) in patients with negative [ 11 C]choline PET/CT. In multivariate analysis, [ 11 C]choline PET/CT (hazard ratio 6.36, 95 % CI 2.14 - 18.94, P < 0.001) and Gleason score >7 (hazard ratio 3.11, 95 % CI 1.11 - 8.66, P = 0.030) predicted PCa-specific survival. An internally validated nomogram predicted 15-year PCa-specific survival probability with an accuracy of 80 %. Positive [ 11 C]choline PET/CT after biochemical failure predicts PCa-specific survival in hormone

  16. SU-F-J-101: Stereotactic Body Radiation Therapy Planning for Primary Prostate Cancer with Selective Intraprostatic Boost Determined by 18F-Choline PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Wu, L [Cancer Hospital of Shantou University Medical College, Shantou, Guangdong (China); Wang, H; Kuang, Y [University of Nevada Las Vegas, Las Vegas, NV (United States); Hirata, E; Kwee, S [Queen’s Medical Center, Honolulu, HI (United States)

    2016-06-15

    Purpose: To investigate the utility of {sup 18}F-choline positron emission tomography (PET) scans guidance for SBRT dose painting in patients with prostate cancer and its impact on tumor control probability (TCP) and normal tissue complication probability (NTCP). Methods: Twenty seven patients with localized prostate cancer who had {sup 18}F-choline PET/CT scan prior to treatment were included. A pair of nested intraprostatic dominant lesion (IDL) contours (IDL{sub suv60%} and IDL{sub suv70%}) were generated for each patient based on 60% and 70% of maximum prostate uptake on the {sup 18}F-choline PET images. GTV{sub reg} was delineated on prostate according to the gland boundary seen on CT images. The PTVs (PTV{sub suv60%} and PTV{sub suv70%}) were defined as respective IDLs with a 3-mm margin posteriorly and 5 mm in all other dimensions. Two 5-fraction SBRT plans using VMAT technique along with 10 MV FFF beams, plan{sub 36Gy} and plan{sub 50–55Gy}, were generated for each patient. All plans included a dose of 36.25 Gy prescribed to PTV{sub reg}. The Plan{sub 50–55Gy} also included a simultaneous boost dose of 50 Gy and 55 Gy prescribed to the PTV{sub suv60%} and PTV{sub suv70%}, respectively. The utility of {sup 18}F-Choline PET-guided SBRT dose escalation was evaluated by its ability to achieve the prescription dose objectives while adhering to organ-at-risk (OAR) dose constraints. The TCP and NTCP calculated by radiological models were also compared between two plans for each patient. Results: In all 54 SBRT plans generated, the planning objectives and dose constraints were met without exception. Plan{sub 50–55Gy} had a significantly higher dose in PTV{sub suv60%} and PTV{sub suv70%} than those in Plan{sub 36Gy} (p < 0.05), respectively, while still maintaining a safe OAR sparing profile. In addition, plan{sub 50–55Gy} had significantly higher TCP than plan{sub 36Gy}. Conclusion: Using VMAT with FFF beams to incorporate a simultaneous {sup 18}F-choline

  17. Prospective head-to-head comparison of {sup 11}C-choline-PET/MR and {sup 11}C-choline-PET/CT for restaging of biochemical recurrent prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Eiber, Matthias [Klinikum rechts der Isar, Department of Nuclear Medicine, Technische Universitaet Muenchen, Munich (Germany); David Geffen School of Medicine at UCLA, Department of Molecular and Medical Pharmacology, Los Angeles (United States); Rauscher, Isabel; Souvatzoglou, Michael; Schwaiger, Markus [Klinikum rechts der Isar, Department of Nuclear Medicine, Technische Universitaet Muenchen, Munich (Germany); Maurer, Tobias [Klinikum rechts der Isar, Department of Urology, Technische Universitaet Muenchen, Munich (Germany); Holzapfel, Konstantin [Klinikum rechts der Isar, Department of Radiology, Technische Universitaet Muenchen, Munich (Germany); Beer, Ambros J. [Klinikum rechts der Isar, Department of Nuclear Medicine, Technische Universitaet Muenchen, Munich (Germany); Ulm University, Department of Nuclear Medicine, Ulm (Germany)

    2017-12-15

    Whole-body integrated {sup 11}C-choline PET/MR might provide advantages compared to {sup 11}C-choline PET/CT for restaging of prostate cancer (PC) due to the high soft-tissue contrast and the use of multiparametric MRI, especially for detection of local recurrence and bone metastases. Ninety-four patients with recurrent PC underwent a single-injection/dual-imaging protocol with contrast-enhanced PET/CT followed by fully diagnostic PET/MR. Imaging datasets were read separately by two reader teams (team 1 and 2) assessing the presence of local recurrence, lymph node and bone metastases in predefined regions using a five-point scale. Detection rates were calculated. The diagnostic performance of PET/CT vs. PET/MR was compared using ROC analysis. Inter-observer and inter-modality variability, radiation exposure, and mean imaging time were evaluated. Clinical follow-up, imaging, and/or histopathology served as standard of reference (SOR). Seventy-five patients qualified for the final image analysis. A total of 188 regions were regarded as positive: local recurrence in 37 patients, 87 regions with lymph node metastases, and 64 regions with bone metastases. Mean detection rate between both readers teams for PET/MR was 84.7% compared to 77.3% for PET/CT (p > 0.05). Local recurrence was identified significantly more often in PET/MR compared to PET/CT by team 1. Lymph node and bone metastases were identified significantly more often in PET/CT compared to PET/MR by both teams. However, this difference was not present in the subgroup of patients with PSA values ≤2 ng/ml. Inter-modality and inter-observer agreement (K > 0.6) was moderate to substantial for nearly all categories. Mean reduction of radiation exposure for PET/MR compared to PET/CT was 79.7% (range, 72.6-86.2%). Mean imaging time for PET/CT was substantially lower (18.4 ± 0.7 min) compared to PET/MR (50.4 ± 7.9 min). {sup 11}C-choline PET/MR is a robust imaging modality for restaging biochemical recurrent PC

  18. (18)F-choline PET/CT pitfalls in image interpretation: an update on 300 examined patients with prostate cancer.

    Science.gov (United States)

    Calabria, Ferdinando; Chiaravalloti, Agostino; Schillaci, Orazio

    2014-02-01

    F-choline PET/CT is an important diagnostic tool in the management of patients with prostate cancer (PC). The aim of this study was to describe and discuss some abnormal sites of uptake that we observed, not due to PC recurrence. Three hundred patients were submitted to F-choline PET/CT for staging or restaging of PC. Whole-body PET/CT was acquired 40 minutes after the F-choline administration. We found abnormal uptake of the tracer, not related to PC, in 48/300 patients (16%). Most of these findings were due to inflammatory processes. Furthermore, some malignant conditions, such as a case of colon cancer, a case of bladder carcinoma, and a multiple myeloma, were diagnosed. Mild uptake was also detected in some benign diseases, such as thymoma, adrenal adenoma, and sarcoidosis. Six patients showed focal brain uptake in correspondence to a meningioma. It is necessary for nuclear physicians, during clinical practice, to consider the possibility of F-choline uptake in some benign or malignant conditions for the intrinsic pharmacologic property of the tracer. An accurate medical investigation, correlative imaging with CT and/or MRI with contrast agents, laboratory data, and above all, histologic examination are often necessary for correct diagnosis.

  19. [{sup 11}C]Choline PET/CT detection of bone metastases in patients with PSA progression after primary treatment for prostate cancer: comparison with bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Picchio, Maria [San Raffaele Scientific Institute, Nuclear Medicine Department, Milan (Italy); National Research Council (IBFM-CNR), Institute for Bioimaging and Molecular Physiology, Milan (Italy); Spinapolice, Elena Giulia; Crivellaro, Cinzia [University of Milano-Bicocca, Center for Molecular Bioimaging, Milan (Italy); Fallanca, Federico; Gianolli, Luigi [San Raffaele Scientific Institute, Nuclear Medicine Department, Milan (Italy); Giovacchini, Giampiero [University of Milano-Bicocca, Center for Molecular Bioimaging, Milan (Italy); University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Messa, Cristina [National Research Council (IBFM-CNR), Institute for Bioimaging and Molecular Physiology, Milan (Italy); University of Milano-Bicocca, Center for Molecular Bioimaging, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine, Monza (Italy)

    2012-01-15

    The aim of this study was to evaluate the clinical usefulness of [{sup 11}C]choline positron emission tomography (PET)/CT in comparison with bone scintigraphy (BS) in detecting bone metastases (BM) of patients with biochemical progression after radical treatment for prostate cancer (PCa). Seventy-eight consecutive patients with biochemical progression of PCa (mean prostate-specific antigen 21.1 ng/ml, range 0.2-500.0 ng/ml) referred for both [{sup 11}C]choline PET/CT and BS for restaging purposes were retrospectively analysed. The diagnostic accuracy of [{sup 11}C]choline PET/CT and BS was assessed by using morphological imaging and/or follow-up as standards of reference. As equivocal findings were found, the accuracy analysis was performed twice, once including them as positive and once as negative. A separate analysis was also performed in hormone-resistant patients and data compared with those of patients who did not receive anti-androgenic treatment. Equivocal findings occurred in 1 of 78 (1%) cases in [{sup 11}C]choline PET/CT and in 21 of 78 (27%) cases in BS. Depending on their attribution as either positive or negative, the ranges of sensitivity, specificity, positive predictive value, negative predictive value and accuracy for [{sup 11}C]choline PET/CT were 89-89%, 98-100%, 96-100%, 94-96% and 95-96%, respectively. For BS they were 100-70%, 75-100%, 68-100%, 100-86% and 83-90%, respectively. Concordant findings between [{sup 11}C]choline PET/CT and BS occurred in 55 of 78 (71%) cases. The accuracy of [{sup 11}C]choline PET/CT did not significantly (p = 0.30) differ between hormone-resistant patients (97%) and those who did not receive anti-androgenic treatment (95%). In clinical practice, [{sup 11}C]choline PET/CT may not replace BS because of its lower sensitivity. However, for its high specificity, [{sup 11}C]choline PET/CT positive findings may accurately predict the presence of BM. Equivocal findings are more frequent in BS than [{sup 11}C]choline PET

  20. 11C-choline vs. 18F-FDG PET/CT in assessing bone involvement in patients with multiple myeloma

    Directory of Open Access Journals (Sweden)

    Ambrosini Valentina

    2007-06-01

    Full Text Available Abstract Background Multiple Myeloma (MM is a B cell neoplasm causing lytic or osteopenic bone abnormalities. Whole body skeletal survey (WBSS, Magnetic resonance (MR and 18F-FDG PET/CT are imaging techniques routinely used for the evaluation of bone involvement in MM patients. Aim As MM bone lesions may present low 18F-FDG uptake; the aim of this study was to assess the possible added value and limitations of 11C-Choline to that of 18F-FDG PET/CT in patients affected with MM. Methods Ten patients affected with MM underwent a standard 11C-Choline PET/CT and an 18F-FDG PET/CT within one week. The results of the two scans were compared in terms of number, sites and SUVmax of lesions. Results Four patients (40% had a negative concordant 11C-Choline and 18F-FDG PET/CT scans. Two patients (20% had a positive 11C-Choline and 18F-FDG PET/CT scans that identified the same number and sites of bone lesions. The remaining four patients (40% had a positive 11C-Choline and 18F-FDG PET/CT scan, but the two exams identified different number of lesions. Choline showed a mean SUVmax of 5 while FDG showed a mean SUVmax of 3.8 (P = 0.042. Overall, 11C-Choline PET/CT scans detected 37 bone lesions and 18F-FDG PET/CT scans detected 22 bone lesions but the difference was not significant (P = 0.8. Conclusion According to these preliminary data, 11C-Choline PET/CT appears to be more sensitive than 18F-FDG PET/CT for the detection of bony myelomatous lesions. If these data are confirmed in larger series of patients, 11C-Choline may be considered a more appropriate functional imaging in association with MRI for MM bone staging.

  1. Evaluation of tumor recurrences after radical prostatectomy using 18F-Choline PET/CT and 3T multiparametric MRI without endorectal coil: a single center experience.

    Science.gov (United States)

    Couñago, Felipe; Recio, Manuel; Maldonado, Antonio; Del Cerro, Elia; Díaz-Gavela, Ana Aurora; Thuissard, Israel J; Sanz-Rosa, David; Marcos, Francisco José; Olaciregui, Karmele; Mateo, María; Cerezo, Laura

    2016-12-07

    To evaluate and compare the utility of 18F-fluorocholine (18F-CH) PET/CT versus 3-Tesla multiparametric MRI (mpMRI) without endorectal coil to detect tumor recurrences in patients with biochemical relapse following radical prostatectomy (RP). Secondarily, to identify possible prognostic variables associated with mpMRI and 18F-CH PET/CT findings. Retrospective study of 38 patients who developed biochemical recurrence after RP between the years 2011 and 2015 at our institution. PET/CT and mpMRI were both performed within 30 days of each other in all patients. The PET/CT was reviewed by a nuclear medicine specialist while the mpMRI was assessed by a radiologist, both of whom were blinded to outcomes. The median prostate-specific antigen (PSA) value pre-MRI/PET-CT was 0.9 ng/mL (interquartile range 0.4-2.2 ng/mL). There were no differences in the detection rate between 18F-CH PET/CT and mpMRI for local recurrence (LR), lymph node recurrence (LNR) and bone metastases (BM). Separately, mpMRI and 18F-CH PET/CT were positive for recurrence in 55.2% and 52.6% of cases, respectively, and in 65.7% of cases when findings from both modalities were considered together. The detection of LR was better with combined mpMRI and choline PET/CT versus choline PET/CT alone (34.2% vs 18.4%, p = 0.04). Salvage treatment was modified in 22 patients (57.8%) based on the imaging findings. PSA values on the day of biochemical failure were significantly associated with mpMRI positivity (adjusted odds ratio (OR): 30.9; 95% confidence interval (CI): 1.5-635.8). Gleason score > 7 was significantly associated with PET/CT positivity (OR: 13.9; 95% CI: 1.5-125.6). A significant association was found between PSA doubling time (PSADT) (OR: 1.3; 95% CI: 1.0-1.7), T stage (OR: 21.1; 95% CI: 1.6-272.1), and LR. Multiparametric MRI and 18F-CH PET/CT yield similar detection rates for LR, LNR and pelvic BM. The combination of both imaging techniques provides a better LR detection versus choline

  2. The value of 18F-choline PET/CT in patients with elevated PSA-level and negative prostate needle biopsy for localisation of prostate cancer

    International Nuclear Information System (INIS)

    Igerc, I.; Kohlfuerst, S.; Gallowitsch, H.J.; Matschnig, S.; Kresnik, E.; Gomez-Segovia, I.; Lind, P.

    2008-01-01

    Patients with persistent elevated PSA and repeated negative prostate biopsy, that means having the prostate biopsied at multiple times, were investigated with 18F-choline PET/CT to delineate prostate cancer and guide renewed prostate biopsy. Twenty patients with elevated PSA and negative prostate biopsies underwent 18F-choline PET/CT. We performed an early examination of the pelvic region 3-5 min after application. After 30 minutes a whole body PET/CT examination was performed. Image analysis was performed visually and by semi-quantitative analysis calculating the maximum standardised uptake value (SUVmax). 18F-choline uptake was defined as focal, multifocal or inhomogeneous. After the 18F-choline PET/CT, all patients underwent a repeated prostate biopsy, and in the cases where a focal or multifocal uptake was found, the biopsy was guided by the result of the examination. Qualitative image analysis revealed focal 18F-choline uptake in 13 out of 20 patients. In five patients, prostate cancer was revealed by repeated aspiration biopsy. None of the patients with a multifocal or inhomogeneous 18F-choline uptake had a malignant neoplasm in the prostate. Semiquantitative analysis performed with SUVmax was not helpful in the discrimination of malignancy but showed high values also in benign prostate diseases, as well as in normal prostate tissue. The dual-phase protocol delivered no clear benefit in discriminating malignancy from benign alterations. The use of 18F-choline cannot be generally recommended for localising prostate cancer; however, in highly selected patients, we found useful additional information. In 25% of patients, 18F-choline PET/CT allowed the identification of neoplastic prostatic zones. (orig.)

  3. Biocompatible choline based ionic salts: Solubility in short-chain alcohols

    International Nuclear Information System (INIS)

    Lopes, Joana M.; Paninho, Ana B.; Môlho, Marta F.; Nunes, Ana V.M.; Rocha, Angelo; Lourenço, Nuno M.T.; Najdanovic-Visak, Vesna

    2013-01-01

    Highlights: • Biocompatible ionic liquids based on choline esters were synthesized in this work. • Solubility of choline and choline esters based ionic salt in alcohols were measured. • Activity coefficients were calculated. • Experimental data were correlated by means of the semi-empirical Grant equation. -- Abstract: In this work, we report data on solubility of choline chloride and choline acetate in short-chain linear alcohols (ethanol, 1-propanol and 1-butanol) at various temperatures. Furthermore, we synthesize two choline derivatives: hydrogen choline chloride glutarate ([CholGlut][Cl]) and hydrogen choline chloride succinate ([CholSucc][Cl]). Their characterization and solubility in short-chain alcohols as a function of temperature are also included. Activity coefficients were calculated and their comparisons with ideal solutions were discussed. The experimental data were correlated successfully by means of the semi-empirical Grant equation

  4. The optimal timing to perform 18F/11C-choline PET/CT in patients with suspicion of relapse of prostate cancer: trigger PSA versus PSA velocity and PSA doubling time.

    Science.gov (United States)

    Calabria, Ferdinando; Rubello, Domenico; Schillaci, Orazio

    2014-12-09

    In the present short communication we considered the main publications focused on trigger prostate-specific antigen (PSA) and PSA kinetics that systematically compared 18F to 11C-choline PET/CT in order to establish the optimal time to perform choline PET/CT in relation to the trigger values and velocity, as well as doubling time of PSA serum levels.

  5. Comparison of 11C-choline-PET/CT and whole body-MRI for staging of prostate cancer

    International Nuclear Information System (INIS)

    Eschmann, S.M.; Rieger, A.; Mueller, M.; Bares, R.; Pfannenberg, A.C.; Aschoff, P.; Claussen, C.D.; Schlemmer, H.P.; Paulsen, F.; Anastasiadis, A.

    2007-01-01

    Aim of this study was to compare the diagnostic accuracy of positron emission tomography and computed tomography with 11 C-Choline (Cho-PET/CT) and whole body magneticresonance imaging (WB-MRI) for diagnostic work-up of prostate cancer. Patients, methods: We evaluated retrospectively 42 patients with untreated prostate cancer (n =17), or increasing levels of prostate-specific antigen (PSA) after curative therapy (n = 25) who had been investigated by both Cho-PET/CT and WB-MRI. MRI, CT, and PET images were separately analyzed by experienced radiologists or nuclear medicine experts, followed by consensus reading. Validation was established by histology, follow-up, or consensus reading. Results: 88/103 detected lesions were considered as malignant: 44 bone metastases, 22 local tumor, 15 lymph node metastases, 3 lung, and 3 brain metastases. One further lesion was located in the adrenal gland, which was a second tumor. Overall sensitivity, specificity and accuracy for Cho-PET/CT were 96.6%, 76.5%, and 93.3%, resp., and for WB-MRI 78.4%, 94.1%, and 81.0%, resp. 3 vertebral metastases had initially been missed by Cho-PET/CT and were found retrospectively. MRI identified 2 bone metastases and 1 lymph node metastasis after being informed about the results of Cho-PET/CT. Conclusions: Cho-PET/CT and WB-MRI both presented high accuracy in the detection of bone and lymph node metastases. The strength of MRI is excellent image quality providing detailed anatomical information whereas the advantage of Cho-PET/CT is high image contrast of pathological foci. (orig.)

  6. Variability of Gross Tumor Volume in Nasopharyngeal Carcinoma Using 11C-Choline and 18F-FDG PET/CT.

    Directory of Open Access Journals (Sweden)

    Jun Jiang

    Full Text Available This study was conducted to evaluate the variability of gross tumor volume (GTV using 11C-Choline and 18F-FDG PET/CT images for nasopharyngeal carcinomas boundary definition. Assessment consisted of inter-observer and inter-modality variation analysis. Four radiation oncologists were invited to manually contour GTV by using PET/CT fusion obtained from a cohort of 12 patients with nasopharyngeal carcinoma (NPC and who underwent both 11C-Choline and 18F-FDG scans. Student's paired-sample t-test was performed for analyzing inter-observer and inter-modality variability. Semi-automatic segmentation methods, including thresholding and region growing, were also validated against the manual contouring of the two types of PET images. We observed no significant variation in the results obtained by different oncologists in terms of the same type of PET/CT volumes. Choline fusion volumes were significantly larger than the FDG volumes (p < 0.0001, mean ± SD = 18.21 ± 8.19. While significantly consistent results were obtained between the oncologists and the standard references in Choline volumes compared with those in FDG volumes (p = 0.0025. Simple semi-automatic delineation methods indicated that 11C-Choline PET images could provide better results than FDG volumes (p = 0.076, CI = [-0.29, 0.025]. 11C-Choline PET/CT may be more advantageous in GTV delineation for the radiotherapy of NPC than 18F-FDG. Phantom simulations and clinical trials should be conducted to prove the possible improvement of the treatment outcome.

  7. Comparison of {sup 68}Ga-labelled PSMA-11 and {sup 11}C-choline in the detection of prostate cancer metastases by PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Schwenck, Johannes [Eberhard Karls University, Department of Nuclear Medicine and Clinical Molecular Imaging, Tuebingen (Germany); Eberhard Karls University, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Rempp, Hansjoerg; Nikolaou, Konstantin; Pfannenberg, Christina [Eberhard Karls University, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Reischl, Gerald [Eberhard Karls University, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Kruck, Stephan; Stenzl, Arnulf [Eberhard Karls University, Department of Urology, Tuebingen (Germany); La Fougere, Christian [Eberhard Karls University, Department of Nuclear Medicine and Clinical Molecular Imaging, Tuebingen (Germany); German Cancer Consortium, German Cancer Research Center Partner Site, Heidelberg (Germany)

    2017-01-15

    Prostate-specific membrane antigen (PSMA) is expressed ubiquitously on the membrane of most prostate tumors and its metastasis. While PET/CT using {sup 11}C-choline was considered as the gold standard in the staging of prostate cancer, PET with radiolabelled PSMA ligands was introduced into the clinic in recent years. Our aim was to compare the PSMA ligand {sup 68}Ga-PSMA-11 with {sup 11}C-choline in patients with primary and recurrent prostate cancer. 123 patients underwent a whole-body PET/CT examination using {sup 68}Ga-PSMA-11 and {sup 11}C-choline. Suspicious lesions were evaluated visually and semiquantitatively (SUVavg). Out of these, 103 suffered from a confirmed biochemical relapse after prostatectomy and/or radiotherapy (mean PSA level of 4.5 ng/ml), while 20 patients underwent primary staging. In 67 patients with biochemical relapse, we detected 458 lymph nodes suspicious for metastasis. PET using {sup 68}Ga-PSMA-11 showed a significantly higher uptake and detection rate than {sup 11}C-choline PET. Also {sup 68}Ga-PSMA-11 PET identified significantly more patients with suspicious lymph nodes as well as affected lymph nodes regions especially at low PSA levels. Bone lesions suspicious for prostate cancer metastasis were revealed in 36 patients' biochemical relapse. Significantly more bone lesions were detected by {sup 68}Ga-PSMA-11, but only 3 patients had only PSMA-positive bone lesions. Nevertheless, we detected also 29 suspicious lymph nodes and 8 bone lesions, which were only positive as per {sup 11}C-choline PET. These findings led to crucial differences in the TNM classification and the identification of oligometastatic patients. In the patients who underwent initial staging, all primary tumors showed uptake of both tracers. Although significantly more suspicious lymph nodes and bone lesions were identified, only 2 patients presented with bone lesions only detected by {sup 68}Ga-PSMA-11 PET. Thus, PET using {sup 68}Ga-PSMA-11 showed a higher

  8. Pattern of occult nodal relapse diagnosed with 18F-fluoro-choline PET/CT in prostate cancer patients with biochemical failure after prostate-only radiotherapy

    International Nuclear Information System (INIS)

    Lépinoy, Alexis; Cochet, Alexandre; Cueff, Adèle; Cormier, Luc; Martin, Etienne; Maingon, Philippe; Bosset, Jean François; Brunotte, François; Créhange, Gilles

    2014-01-01

    Introduction: The purpose of this study was to describe the pattern of nodal relapse with 18 F-fluoro-choline (FCH) Positron Emission Tomography/Computerized Tomography (PET/CT) in prostate cancer patients after radiotherapy. Materials and methods: Eighty-three patients had a FCH PET/CT at time of biochemical failure. Of 65 patients with positive findings, 33 had positive nodes. This analysis included 31 patients who had undergone prior prostate-only radiotherapy with or without a prior radical prostatectomy. Each FCH positive node was assigned to a lymph node station with respect to the CTV defined by the RTOG guidelines (CTV RTOG ). 3D mapping was performed after each node was manually placed in a reference planning CT scan after automatic co-registration of the two scans based on bone anatomy. Eighteen patients (58%) underwent focal salvage FCH PET-guided stereotactic radiotherapy with no hormones. Results: Fourteen patients (45.2%) had a relapse outside the CTV RTOG . Of the 17 patients with a positive node inside the CTV RTOG , 15 had a single node (88.2%) while seven patients out of the 13 evaluable patients (53.9%) who had a relapse outside the CTV RTOG had ⩾2 positive nodes on FCH PET/CT (OR = 8.75, [95% CI: 1.38–54.80], p = 0.020). Relapses that occurred outside the CTV RTOG involved the proximal common iliac (19.3%) and lower periaortic nodes (19.3%) up to L2–L3. Conclusion: 3D mapping of nodal relapses evaluated with FCH PET/CT suggests that with IMRT the upper field limit of pelvic radiotherapy could be extended to L2–L3 safely to cover 95% of nodal stations at risk of an occult relapse

  9. Targeting personalized medicine in a non-Hodgkin lymphoma patient with {sup 18F}-FDG and {sup 18F}-choline PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Thalles H.; Filho, Raul S.; Castro, Ana Carolina G.; Paulino Junior, Eduardo; Mamede, Marcelo, E-mail: mamede.mm@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2017-02-15

    Early diagnosis and staging of non-Hodgkin lymphoma (NHL) is essential for therapeutic strategy decision. Positron emission tomography/computed tomography (PET/CT) with fluorodeoxyglucose (FDG), a glucose analogue, labeled with fluor-18 ({sup 18F}-FDG) has been used to evaluate staging, therapy response and prognosis in NHL patients. However, in some cases, {sup 18F}-FDG has shown false- -positive uptake due to inflammatory reaction after chemo and/or radiation therapy. In this case report, we present a NHL patient evaluated with {sup 18F}-FDG and {sup 18F}-choline PET/CT scan imaging pre- and post-therapy. {sup 18F}-FDG and {sup 18F}-choline PET/CT were performed for the purpose of tumor staging and have shown intense uptake in infiltrative tissue as well as in the lymph node, but with some mismatching in the tumor. Post-treatment {sup 18F}-FDG and {sup 18F}-choline PET/ CT scans revealed no signs of radiotracer uptake, suggesting complete remission of the tumor. {sup 18F}-choline may be a complimentary tool for staging and assessment of therapeutic response in non-Hodgkin lymphoma, while non-{sup 18F}-FDG tracer can be used for targeted therapy and patient management. (author)

  10. PET/CT with 18F-choline: Physiological whole bio-distribution in male and female subjects and diagnostic pitfalls on 1000 prostate cancer patients: 18F-choline PET/CT bio-distribution and pitfalls. A southern Italian experience.

    Science.gov (United States)

    Calabria, Ferdinando; Chiaravalloti, Agostino; Cicciò, Carmelo; Gangemi, Vincenzo; Gullà, Domenico; Rocca, Federico; Gallo, Gianpasquale; Cascini, Giuseppe Lucio; Schillaci, Orazio

    2017-08-01

    The 11 C/ 18 F-choline is a PET/CT radiopharmaceutical useful in detecting tumors with high lipogenesis. 11 C/ 18 F-choline uptake can occur in physiological conditions or tumors. The knowledge of its bio-distribution is essential to recognize physiologic variants or diagnostic pitfalls. Moreover, few information are available on the bio-distribution of this tracer in female patients. Our aim was to discuss some documented 18 F-choline PET/CT pitfalls in prostate cancer patients. Our secondary aim was to describe the 18 F-choline bio-distribution in the female body. We collected diagnostic pitfalls in three PET centers examining 1000 prostate cancer by 18 F-choline PET/CT. All pitfalls were ensured by follow-up, imaging and/or histology. We also performed whole body 18 F-choline PET/CT in 5 female patients. 169/1000 (16.9%) patients showed pitfalls not owing to prostate cancer. These findings were due to inflammation, benign tumors while, in 1% of examined patients, a concomitant neoplasm was found. In the female body, the breast showed low physiological uptake. The accurate knowledge of 18 F-choline PET/CT bio-distribution and diagnostic pitfalls is essential. Correlative imaging and histological exam are often necessary to depict pitfalls. In women, the uptake in the breast is due to the physiological gradient of 18 F-choline uptake in the exocrine glands. Our results confirm the possibility of 18 F-choline uptake in several diseases other than prostate cancer. However, our experience was acquired on a large population and shows that a conspicuous amount of 18 F-choline diagnostic pitfalls are easily recognizable and attributable to inflammation. A new advance in knowledge is the minimal difference in terms of physiological tracer bio-distribution between male and female patients. The knowledge of the physiological bio-distribution and of the potential pitfalls linked of a tracer could help physicians to choose the best diagnostic and therapeutic approaches for a

  11. Is the detection rate of 18F-choline PET/CT influenced by androgen-deprivation therapy?

    Energy Technology Data Exchange (ETDEWEB)

    Chondrogiannis, Sotirios; Marzola, Maria Cristina; Grassetto, Gaia; Maffione, Anna Margherita; Rampin, Lucia; Rubello, Domenico [' ' Santa Maria della Misericordia' ' Hospital, Rovigo (Italy). PET/CT Centre; Ferretti, Alice [' ' San Giacomo Apostolo' ' Hospital, Castelfranco Veneto, Treviso (Italy). Service of Medical Physics; Fanti, Stefano [Azienda Ospedaliero-Univ. Policlinico S. Orsola-Malpighi, Bologna (Italy). Dept. of Nuclear Medicine; Giammarile, Francesco [Lyon 1 Univ. Centre Hospitalier Lyon Sud Biophysique, Villeurbanne (Italy). Dept. of Nuclear Medicine

    2014-07-15

    To evaluate if the detection rate (DR) of {sup 18}F-choline (18F-CH) PET/CT is influenced by androgen-deprivation therapy (ADT) in patients with prostate cancer (PC) already treated with radical intent and presenting biochemical relapse. We have retrospectively evaluated {sup 18}F-CH PET/CT scans of 325 consecutive PC patients enrolled in the period November 2009 to December 2012 previously treated with radical intent and referred to our centre to perform {sup 18}F-CH PET/CT for biochemical relapse. Two different groups of patients were evaluated. group A included the whole sample of 325 patients (mean age 70 years, range: 49-86) who presented trigger PSA between 0.1 and 80 ng/ml (mean 5.5 ng/ml), and group B included 187 patients (mean age 70 years, range 49-86) with medium-low levels of trigger PSA ranging between 0.5 and 5 ng/ml (mean PSA 2.1 ng/ml); group B was chosen in order to obtain a more homogeneous group of patients in terms of PSA values also excluding both very low and very high PSA levels avoiding the ''a priori'' higher probability of negative or positive PET scan, respectively. At the time of examination, 139 patients from group A and 72 patients from group B were under ADT: these patients were considered to be hormone-resistant PC patients because from their oncologic history (>18 months) an increase of PSA levels emerged despite the ongoing ADT. The relationship between {sup 18}F-CH PET/CT findings and possible clinical predictors was investigated using both univariate and multivariate binary logistic regression analyses, including trigger PSA and ADT. Considering the whole population, overall DR of {sup 18}F-CH PET was 58.2 % (189/325 patients). In the whole sample of patients (group A), both at the univariate and multivariate logistic regression analysis, trigger PSA and ADT were significantly correlated with the DR of {sup 18}F-CH PET (p < 0.05). Moreover, the DR in patients under ADT (mean PSA 7.8 ng/ml) was higher than in

  12. Is the detection rate of 18F-choline PET/CT influenced by androgen-deprivation therapy?

    International Nuclear Information System (INIS)

    Chondrogiannis, Sotirios; Marzola, Maria Cristina; Grassetto, Gaia; Maffione, Anna Margherita; Rampin, Lucia; Rubello, Domenico; Ferretti, Alice; Fanti, Stefano; Giammarile, Francesco

    2014-01-01

    To evaluate if the detection rate (DR) of 18 F-choline (18F-CH) PET/CT is influenced by androgen-deprivation therapy (ADT) in patients with prostate cancer (PC) already treated with radical intent and presenting biochemical relapse. We have retrospectively evaluated 18 F-CH PET/CT scans of 325 consecutive PC patients enrolled in the period November 2009 to December 2012 previously treated with radical intent and referred to our centre to perform 18 F-CH PET/CT for biochemical relapse. Two different groups of patients were evaluated. group A included the whole sample of 325 patients (mean age 70 years, range: 49-86) who presented trigger PSA between 0.1 and 80 ng/ml (mean 5.5 ng/ml), and group B included 187 patients (mean age 70 years, range 49-86) with medium-low levels of trigger PSA ranging between 0.5 and 5 ng/ml (mean PSA 2.1 ng/ml); group B was chosen in order to obtain a more homogeneous group of patients in terms of PSA values also excluding both very low and very high PSA levels avoiding the ''a priori'' higher probability of negative or positive PET scan, respectively. At the time of examination, 139 patients from group A and 72 patients from group B were under ADT: these patients were considered to be hormone-resistant PC patients because from their oncologic history (>18 months) an increase of PSA levels emerged despite the ongoing ADT. The relationship between 18 F-CH PET/CT findings and possible clinical predictors was investigated using both univariate and multivariate binary logistic regression analyses, including trigger PSA and ADT. Considering the whole population, overall DR of 18 F-CH PET was 58.2 % (189/325 patients). In the whole sample of patients (group A), both at the univariate and multivariate logistic regression analysis, trigger PSA and ADT were significantly correlated with the DR of 18 F-CH PET (p 18 F-CH PET and ADT. In group B patients only trigger PSA resulted a reliable predictor of the 18 F-CH positivity, since ADT was not

  13. Prospective Comparison of F-18 Choline PET/CT Scan Versus Axial MRI for Detecting Bone Metastasis in Biochemically Relapsed Prostate Cancer Patients

    Directory of Open Access Journals (Sweden)

    Wouter Huysse

    2017-10-01

    Full Text Available We compared fluor-18 choline positron emission tomography/computed tomography (PET/CT and axial skeleton magnetic resonance imaging (MRI prospectively obtained for the detection of bone metastases in non-castrated patients with biochemically recurrent prostate cancer following primary treatment. PET/CT was performed 45 min post-injection of 3–4 MBq/kg F-18 methyl choline. MRI included T1- and fluid sensitive T2-weighted images of the spine and pelvis. Readers were initially blinded from other results and all scans underwent independent double reading. The best valuable comparator (BVC defined the metastatic status. On the basis of the BVC, 15 out of 64 patients presented with 24 bone metastases. On a patient level, the sensitivity and specificity of MRI and PET were not significantly different. On a lesion level, the sensitivity of MRI was significantly better compared to PET, and the specificity did not differ significantly. In conclusion, axial MRI is an interesting screening tool for the detection of bone metastases because of its low probability of false negative results. However, F-18 choline PET is a valuable addition as it can overrule false positive MRI results and detect non-axial metastases.

  14. Is There an Additional Value of 11C-Choline PET-CT to T2-weighted MRI Images in the Localization of Intraprostatic Tumor Nodules?

    International Nuclear Information System (INIS)

    Van den Bergh, Laura; Koole, Michel; Isebaert, Sofie; Joniau, Steven; Deroose, Christophe M.; Oyen, Raymond; Lerut, Evelyne; Budiharto, Tom; Mottaghy, Felix; Bormans, Guy; Van Poppel, Hendrik; Haustermans, Karin

    2012-01-01

    Purpose: To investigate the additional value of 11 C-choline positron emission tomography (PET)-computed tomography (CT) to T2-weighted (T2w) magnetic resonance imaging (MRI) for localization of intraprostatic tumor nodules. Methods and Materials: Forty-nine prostate cancer patients underwent T2w MRI and 11 C-choline PET-CT before radical prostatectomy and extended lymphadenectomy. Tumor regions were outlined on the whole-mount histopathology sections and on the T2w MR images. Tumor localization was recorded in the basal, middle, and apical part of the prostate by means of an octant grid. To analyze 11 C-choline PET-CT images, the same grid was used to calculate the standardized uptake values (SUV) per octant, after rigid registration with the T2w MR images for anatomic reference. Results: In total, 1,176 octants were analyzed. Sensitivity, specificity, and accuracy of T2w MRI were 33.5%, 94.6%, and 70.2%, respectively. For 11 C-choline PET-CT, the mean SUV max of malignant octants was significantly higher than the mean SUV max of benign octants (3.69 ± 1.29 vs. 3.06 ± 0.97, p mean values (2.39 ± 0.77 vs. 1.94 ± 0.61, p mean and absolute tumor volume (Spearman r = 0.3003, p = 0.0362). No correlation was found between SUVs and prostate-specific antigen, T-stage or Gleason score. The highest accuracy (61.1%) was obtained with a SUV max cutoff of 2.70, resulting in a sensitivity of 77.4% and a specificity of 44.9%. When both modalities were combined (PET-CT or MRI positive), sensitivity levels increased as a function of SUV max but at the cost of specificity. When only considering suspect octants on 11 C-choline PET-CT (SUV max ≥ 2.70) and T2w MRI, 84.7% of these segments were in agreement with the gold standard, compared with 80.5% for T2w MRI alone. Conclusions: The additional value of 11 C-choline PET-CT next to T2w MRI in detecting tumor nodules within the prostate is limited.

  15. Incidental detection of colorectal cancer via 1(8)F-choline PET/CT in a patient with recurrent prostate cancer: usefulness of early images.

    Science.gov (United States)

    Bagni, Oreste; Filippi, Luca; Schillaci, Orazio

    2015-06-01

    A 74-year-old man with history of prostate cancer underwent F-choline PET/CT for restaging. Early acquisition of the pelvic region revealed intense uptake in prostate, with infiltration of the posterior wall of the bladder. Furthermore, focal uptake in the thickened anterior wall of the rectum was detected. Whole-body scan at 60 minutes confirmed early findings in pelvis, although the infiltration of the bladder was no more evident due to interference of radioactive urine. Biopsy demonstrated the presence of colorectal carcinoma. The dual-phase protocol resulted in significant clinical impact to clearly characterize focuses of abnormal F-choline uptake in the pelvic region.

  16. New Acquisition Protocol of 18F-Choline PET/CT in Prostate Cancer Patients: Review of the Literature about Methodology and Proposal of Standardization

    Directory of Open Access Journals (Sweden)

    Sotirios Chondrogiannis

    2014-01-01

    Full Text Available Purpose. (1 To evaluate a new acquisition protocol of 18F-choline (FCH PET/CT for prostate cancer patients (PC, (2 to review acquisition 18F-choline PET/CT methodology, and (3 to propose a standardized acquisition protocol on FCH PET/CT in PC patients. Materials. 100 consecutive PC patients (mean age 70.5 years, mean PSA 21.35 ng/mL were prospectively evaluated. New protocol consisted of an early scan of the pelvis immediately after the injection of the tracer (1 bed position of 4 min followed by a whole body scan at one 1 hour. Early and 1 hour images were compared for interfering activity and pathologic findings. Results. The overall detection rate of FCH PET/CT was 64%. The early static images of the pelvis showed absence of radioactive urine in ureters, bladder, or urethra which allowed a clean evaluation of the prostatic fossae. Uptake in the prostatic region was better visualized in the early phase in 26% (7/30 of cases. Other pelvic pathologic findings (bone and lymph nodes were visualized in both early and late images. Conclusion. Early 18F-choline images improve visualization of abnormal uptake in prostate fossae. All pathologic pelvic deposits (prostate, lymph nodes, and bone were visualized in both early and late images.

  17. Imaging primary prostate cancer with 11C-Choline PET/CT: relation to tumour stage, Gleason score and biomarkers of biologic aggressiveness

    International Nuclear Information System (INIS)

    Chen, Ji; Zhao, Yong; Li, Xin; Sun, Peng; Wang, Muwen; Wang, Ridong; Jin, Xunbo

    2012-01-01

    As a significant overlap of 11C-Choline standardized uptake value (SUV) between prostate cancer and benign prostate hyperplasia (BPH) tissue, controversy exists regarding the clinical value of 11C-Choline PET/CT scan in primary prostate cancer. In this study, the SUVmax of the prostate lesions and the pelvic muscles were measured and their ratios (SUVmax-P/M ratio) were calculated. Then we evaluated whether the tracer 11C-Choline uptake, quantified as SUVmax-P/M ratio, correlated with tumour stage, Gleason score, and expression levels of several biomarkers of aggressiveness. Twenty-six patients with primary prostate cancer underwent 11C-Choline PET/CT. Tumour specimens from these patients were graded histopathologically, and immunnohistochemistry for Ki-67, CD31, androgen receptor (AR), Her-2/neu, Bcl-2, and PTEN were performed. Both SUVmax and SUVmax-P/M ratio showed no significant difference between patients with tumour stage II and III, but significantly elevated in patients with tumour stage IV. SUVmax-P/M ratio was also significantly higher in lesions with Gleason score of 4+3 or higher versus less than or equal to 3+4. SUVmax-P/M ratio was found significantly correlated with expression levels of Ki-67 and CD31. In addition, a higher SUVmax-P/M ratio was demonstrated in Her-2/neu positive subgroup than negative subgroup. At the same time, Gleason score and expression levels of these biomarkers showed no significant association with SUVmax. Using the parameter SUVmax-P/M ratio, 11C-Choline PET/CT may be a valuable non-invasive imaging technology in the diagnosis of primary prostate cancer

  18. Assessment of Lymph Nodes and Prostate Status Using Early Dynamic Curves with (18)F-Choline PET/CT in Prostate Cancer.

    Science.gov (United States)

    Mathieu, Cédric; Ferrer, Ludovic; Carlier, Thomas; Colombié, Mathilde; Rusu, Daniela; Kraeber-Bodéré, Françoise; Campion, Loic; Rousseau, Caroline

    2015-01-01

    Dynamic image acquisition with (18)F-Choline [fluorocholine (FCH)] PET/CT in prostate cancer is mostly used to overcome the bladder repletion, which could obstruct the loco-regional analysis. The aim of our study was to analyze early dynamic FCH acquisitions to define pelvic lymph node or prostate pathological status. Retrospective analysis was performed on 39 patients for initial staging (n = 18), or after initial treatment (n = 21). Patients underwent 10-min dynamic acquisitions centered on the pelvis, after injection of 3-4 MBq/kg of FCH. Whole-body images were acquired about 1 h after injection using a PET/CT GE Discovery LS (GE-LS) or Siemens Biograph mCT (mCT). Maximum and mean SUV according to time were measured on nodal and prostatic lesions. SUVmean was corrected for partial volume effect (PVEC) with suitable recovery coefficients. The status of each lesion was based on histological results or patient follow-up (>6 months). A Mann-Whitney test and ANOVA were used to compare mean and receiver operating characteristic (ROC) curve analysis. The median PSA was 8.46 ng/mL and the median Gleason score was 3 + 4. Ninety-two lesions (43 lymph nodes and 49 prostate lesions) were analyzed, including 63 malignant lesions. In early dynamic acquisitions, the maximum and mean SUV were significantly higher, respectively, on mCT and GE-LS, in malignant versus benign lesions (p dynamic imaging using PET/CT FCH allowed prostate cancer detection in situations where proof of malignancy is difficult to obtain.

  19. PET/CT with {sup 11}C-choline for evaluation of prostate cancer patients with biochemical recurrence: meta-analysis and critical review of available data

    Energy Technology Data Exchange (ETDEWEB)

    Fanti, Stefano; Castellucci, Paolo [S. Orsola-Malpighi University Hospital, Department of Nuclear Medicine, Bologna (Italy); Minozzi, Silvia [Lazio Regional Health Service, Cochrane Review Group on Drugs and Alcohol, Department of Epidemiology, Rome (Italy); Balduzzi, Sara [University of Modena and Reggio Emilia, Department of Diagnostic Medicine, Clinical and Public Health, Modena (Italy); Herrmann, Ken [David Geffen School of Medicine at UCLA, Department of Molecular and Medical Pharmacology, Los Angeles, CA (United States); University Hospital Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Krause, Bernd Joachim [Universitaetsmedizin Rostock, Department of Nuclear Medicine, Rostock (Germany); Oyen, Wim [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Chiti, Arturo [Humanitas Research Hospital, Nuclear Medicine, Rozzano, Milano (Italy); Humanitas University, Rozzano, Milano (Italy)

    2016-01-15

    For the last decade PET and PET/CT with {sup 11}C-choline have been proposed for the evaluation of prostate cancer (PC), but the diagnostic performance of {sup 11}C-choline PET/CT is still a matter of debate. We performed a comprehensive review of the most important clinical application of {sup 11}C-choline PET, restaging of patients with biochemical relapse, following a rigorous methodological approach and including assessment of the risk of bias. We conducted a systematic review and meta-analysis of the literature assessing {sup 11}C-choline PET/CT for its accuracy in the diagnosis and ability to detect the site of recurrence of PC in the restaging of patients with biochemical recurrence after initial treatment with curative intent. We performed a comprehensive literature search of PubMed and the Cochrane Library to determine the accuracy for the detection of the site of recurrence (prostate bed recurrences, metastatic spread to locoregional pelvic lymph nodes or distant metastases). Only studies with a reference standard (for prostatic bed histopathology, for histopathology or biopsy of distant metastases or a composite reference standard with clinical follow-up of at least 12 months, correlative imaging and clinical data) were included. Overall 425 studies were retrieved, of which 43 were judged as potentially relevant and 29 with 2,686 participants were finally included. Of these 29 studies, 18 reported results for any relapse, All 18 studies, with a total of 2,126 participants, reported detection rates. The pooled rate was 62 % (95 % CI 53 - 71 %). Of the 18 studies, 12 with 1,270 participants reported useful data to derive sensitivity and specificity. The pooled sensitivity was 89 % (95 % CI 83 - 93 %) and the pooled specificity was 89 % (95 % CI 73 - 96 %). Of 11 studies reporting results for local relapse, 9 with 993 participants reported detection rates. The pooled rate was 27 % (95 % CI 16 - 38 %). Six studies with 491 participants reported sensitivity

  20. Choline-based biodegradable ionic liquid catalyst for Mannich-type

    Indian Academy of Sciences (India)

    Choline-based biodegradable ionic liquid catalyst for Mannich-type reaction ... Abstract. A three-component Mannich-type reaction of aromatic aldehydes, ketones, and amines was catalyzed by a novel ... Journal of Chemical Sciences | News.

  1. {sup 11}C-Choline PET/CT for restaging prostate cancer. Results from 4,426 scans in a single-centre patient series

    Energy Technology Data Exchange (ETDEWEB)

    Graziani, Tiziano; Ceci, Francesco; Polverari, Giulia; Lima, Giacomo Maria; Lodi, Filippo; Fanti, Stefano [S. Orsola-Malpighi Hospital, University of Bologna, Service of Nuclear Medicine, Bologna (Italy); Castellucci, Paolo [S. Orsola-Malpighi Hospital, University of Bologna, Service of Nuclear Medicine, Bologna (Italy); Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, UO Medicina Nucleare, Bologna (Italy); Morganti, Alessio Giuseppe [S. Orsola-Malpighi Hospital, University of Bologna, Department of Radiotherapy, Bologna (Italy); Ardizzoni, Andrea [S. Orsola-Malpighi Hospital, University of Bologna, Department of Oncology, Bologna (Italy); Schiavina, Riccardo [S. Orsola-Malpighi Hospital, University of Bologna, Department of Urology, Bologna (Italy)

    2016-10-15

    To evaluate {sup 11}C-choline PET/CT as a diagnostic tool for restaging prostate cancer (PCa), in a large, homogeneous and clinically relevant population of patients with biochemical recurrence (BCR) of PCa after primary therapy. The secondary aim was to assess the best timing for performing {sup 11}C-choline PET/CT during BCR. We retrospectively analysed 9,632 {sup 11}C-choline PET/CT scans performed in our institution for restaging PCa from January 2007 to June 2015. The inclusion criteria were: (1) proven PCa radically treated with radical prostatectomy (RP) or with primary external beam radiotherapy (EBRT); (2) PSA serum values available; (3) proven BCR (PSA >0.2 ng/mL after RP or PSA >2 ng/mL above the nadir after primary EBRT with rising PSA levels). Finally, 3,203 patients with recurrent PCa matching all the inclusion criteria were retrospectively enrolled and 4,426 scans were analysed. Overall, 52.8 % of the {sup 11}C-choline PET/CT scans (2,337/4,426) and 54.8 % of the patients (1,755/3,203) were positive. In 29.4 % of the scans, at least one distant finding was observed. The mean and median PSA values were, respectively, 4.9 and 2.1 ng/mL at the time of the scan (range 0.2 - 50 ng/mL). In our series, 995 scans were performed in patients with PSA levels between 1 and 2 ng/mL. In this subpopulation the positivity rate in the 995 scans was 44.7 %, with an incidence of distant findings of 19.2 % and an incidence of oligometastatic disease (one to three lesions) of 37.7 %. The absolute PSA value at the time of the scan and ongoing androgen deprivation therapy were associated with an increased probability of a positive {sup 11}C-choline PET/CT scan (p < 0.0001). In the ROC analysis, a PSA value of 1.16 ng/mL was the optimal cut-off value. In patients with a PSA value <1.16 ng/mL, 26.8 % of 1,426 {sup 11}C-choline PET/CT scans were positive, with oligometastatic disease in 84.7 % of positive scans. In a large cohort of patients, the feasibility of {sup 11}C-choline

  2. Gamma camera based FDG PET in oncology

    International Nuclear Information System (INIS)

    Park, C. H.

    2002-01-01

    Positron Emission Tomography(PET) was introduced as a research tool in the 1970s and it took about 20 years before PET became an useful clinical imaging modality. In the USA, insurance coverage for PET procedures in the 1990s was the turning point, I believe, for this progress. Initially PET was used in neurology but recently more than 80% of PET procedures are in oncological applications. I firmly believe, in the 21st century, one can not manage cancer patients properly without PET and PET is very important medical imaging modality in basic and clinical sciences. PET is grouped into 2 categories; conventional (c) and gamma camera based ( CB ) PET. CB PET is more readily available utilizing dual-head gamma cameras and commercially available FDG to many medical centers at low cost to patients. In fact there are more CB PET in operation than cPET in the USA. CB PET is inferior to cPET in its performance but clinical studies in oncology is feasible without expensive infrastructures such as staffing, rooms and equipments. At Ajou university Hospital, CBPET was installed in late 1997 for the first time in Korea as well as in Asia and the system has been used successfully and effectively in oncological applications. Our was the fourth PET operation in Korea and I believe this may have been instrumental for other institutions got interested in clinical PET. The following is a brief description of our clinical experience of FDG CBPET in oncology

  3. 68Ga-PSMA and 11C-Choline comparison using a tri-modality PET/CT-MRI (3.0 T) system with a dedicated shuttle.

    Science.gov (United States)

    Alonso, Omar; Dos Santos, Gerardo; García Fontes, Margarita; Balter, Henia; Engler, Henry

    2018-01-01

    The aim of this study was to prospectively compare the detection rate of 68 Ga-PSMA versus 11 C-Choline in men with prostate cancer with biochemical recurrence and to demonstrate the added value of a tri-modality PET/CT-MRI system. We analysed 36 patients who underwent both 11 C-Choline PET/CT and 68 Ga-PSMA PET/CT scanning within a time window of 1-2 weeks. Additionally, for the 68 Ga-PSMA scan, we used a PET/CT-MRI (3.0 T) system with a dedicated shuttle, acquiring MRI images of the pelvis. Both scans were positive in 18 patients (50%) and negative in 8 patients (22%). Nine patients were positive with 68 Ga-PSMA alone (25%) and one with 11 C-Choline only (3%). The median detected lesion per patient was 2 for 68 Ga-PSMA (range 0-93) and 1 for 11 C-Choline (range 0-57). Tumour to background ratios in all concordant lesions ( n  = 96) were higher for 68 Ga-PSMA than for 11 C-Choline (110.3 ± 107.8 and 27.5 ± 17.1, mean ± S.D., for each tracer, respectively P  = 0.0001). The number of detected lesions per patient was higher for 11 C-Choline in those with PSA ≥ 3.3 ng/mL, while the number of detected lesions was independent of PSA levels for 68 Ga-PSMA using the same PSA cut-off value. Metastatic pelvic lesions were found in 25 patients (69%) with 68 Ga-PSMA PET/CT, in 18 (50%) with 11 C-Choline PET/CT and in 21 (58%) with MRI (3.0 T). MRI was very useful in detecting recurrence in cases classified as indeterminate by means of PET/CT alone at prostate bed. In patients with prostate cancer with biochemical recurrence 68 Ga-PSMA detected more lesions per patient than 11 C-Choline, regardless of PSA levels. PET/CT-MRI (3.0 T) system is a feasible imaging modality that potentially adds useful relevant information with increased accuracy of diagnosis.

  4. Positron emission tomographic imaging with 11C-choline in differential diagnosis of head and neck tumors. Comparison with 18F-FDG PET

    International Nuclear Information System (INIS)

    Khan, N.; Oriuchi, Noboru; Ninomiya, Hiroshi; Higuchi, Tetsuya; Kamada, Hideo; Endo, Keigo

    2004-01-01

    The aim of this study was to evaluate the clinical value of positron emission tomography (PET) with 11 C-labeled choline (CHOL) for the differential diagnosis of malignant head and neck tumors from benign lesions as compared with 18 F-fluorodeoxyglucose PET. We studied 45 patients (28 males, 17 females, age range, 29-84 years) with suspected lesions in the head and neck region using both CHOL and FDG PET within a 2-week period on each patient. All patients fasted for at least 6 hours for both the CHOL and FDG studies. PET imaging was performed 5 min and 50-60 min after intravenous injection of CHOL and FDG, respectively. After data acquisition, PET images were corrected for attenuation, and the reconstructed images were analyzed by visual interpretation. Then, the standardized uptake value (SUV) was calculated for semiquantitative evaluation of tumor tracer uptake. Finally the results of PET scans were compared with the histological diagnoses from surgical specimens or biopsies. With CHOL PET, malignant tumors were correctly detected in 24 (96%) of 25 patients, and benign lesions in 14 (70%) of 20 patients with an accuracy of 84.4%. With FDG PET, malignancy was correctly diagnosed in 23 (92%) of 25 patients, and benign lesions in 13 (65%) of 20 patients resulting an accuracy of 80%. A significant positive correlation between CHOL and FDG SUVs was found for all lesions (r=0.677, p=0.004, n=45). Malignant tumors showed significantly higher tracer accumulation than the benign lesions in both CHOL and FDG studies (5.69±1.61, n=25 vs. 2.98±2.13, n=20, p<0.0001; 9.21±4.23, n=25 vs. 3.60±2.57, n=20, p<0.0001). The cutoff SUV for differentiating malignant and benign lesions was 3.5 for CHOL and 3.9 for FDG. CHOL showed slightly better differentiation between malignant and benign lesions than FDG although some overlap existed on both studies. But the difference was not statistically significant. The results of this study indicate that CHOL PET may be feasible clinically

  5. An electrochemiluminescence-based fibre optic biosensor for choline flow injection analysis.

    Science.gov (United States)

    Tsafack, V C; Marquette, C A; Leca, B; Blum, L J

    2000-01-01

    A fibre optic biosensor based on luminol electrochemiluminescence (ECL) integrated in a flow injection analysis (FIA) system was developed for the detection of choline. The electrochemiluminescence of luminol was generated by a glassy carbon electrode polarised at +425 mV vs. a platinum pseudo-reference electrode. Choline oxidase (Chx) was immobilised either covalently on polyamide (ABC type) or on UltraBind preactivated membranes, or by physical entrapment in a photo-cross-linkable poly(vinyl alcohol) polymer (PVA-SbQ) alone or after absorption on a weak anion exchanger, DEAE (diethylaminoethyl) Sepharose. The optimisation of the reaction conditions and physicochemical parameters influencing the FIA biosensor response demonstrated that the choline biosensor exhibited the best performances in a 30 mM veronal buffer containing 30 mM KCl and 1.5 mM MgCl2, at pH 9. The use of a 0.5 ml min-1 flow rate enabled the measurement of choline by the membrane-based ECL biosensors in 8 or 5 min, with ABC or UltraBind membranes, respectively, whereas the measurement required only 3 min with the DEAE-PVA system. For comparison, the detection of choline was performed with Chx immobilised using the four different supports. The best performances were obtained with the DEAE-PVA-Chx sensing layer, which allowed a detection limit of 10 pmol, whereas with the ABC, the UltraBind and the PVA systems, the detection limits were 300 pmol, 75 pmol and 220 pmol, respectively. The DEAE-based system also exhibited a good operational stability since 160 repeated measurements of 3 nmol of choline could be performed with an RSD of 4.5% whereas the stability under the best conditions was 45 assays with the other supports.

  6. F18-choline PET/CT guided surgery in primary hyperparathyroidism when ultrasound and MIBI SPECT/CT are negative or inconclusive: the APACH1 study.

    Science.gov (United States)

    Quak, Elske; Blanchard, David; Houdu, Benjamin; Le Roux, Yannick; Ciappuccini, Renaud; Lireux, Barbara; de Raucourt, Dominique; Grellard, Jean-Michel; Licaj, Idlir; Bardet, Stéphane; Reznik, Yves; Clarisse, Bénédicte; Aide, Nicolas

    2018-04-01

    To evaluate the sensitivity of F18-choline (FCH) PET/CT for parathyroid adenoma detection prior to surgery in patients with primary hyperparathyroidism and negative or inconclusive cervical ultrasound and Tc99m-sestaMIBI SPECT/CT. We conducted a prospective bicentric study (NCT02432599). All patients underwent FCH PET/CT. The result was scored positive, inconclusive or negative. The number of uptakes and their sites were recorded. The FCH PET/CT result guided the surgical procedure (minimally invasive parathyroidectomy, bilateral cervical exploration, or other in case of multiple or ectopic foci). FCH PET/CT results were compared to the surgical and pathological findings and the follow-up. Twenty-five patients were included. Mean calcium and PTH levels prior to surgery were 2.76 ± 0.17 mmol/l and 94.8 ± 37.4 ng/l. Nineteen (76%) FCH PET/CTs were scored positive, 3 (12%) inconclusive and 3 (12%) negative, showing 21 cases of uniglandular disease, including 1 ectopic localization and 1 case of multiglandular (3 foci) disease. Mean lesion size was 13.1 ± 8.6 mm. Twenty-four patients underwent surgery. FCH PET/CT guided surgery in 22 (88%) patients, allowing for 17 minimally invasive parathyroidectomies, 1 bilateral cervical exploration for multifocality and 4 other surgical procedures. Two patients with negative FCH-PET/CT underwent bilateral cervical exploration. When dichotomizing the FCH PET/CT results, thereby classifying the inconclusive FCH PET/CT results as positive, the per lesion and per patient sensitivities were 91.3% (95%CI: 72.0-98.9) and 90.5% (95%CI: 69.6-98.8) and the corresponding positive predictive values were 87.5% (95%CI: 67.6-97.3) and 86.4% (95%CI: 65.1-97.1), respectively. Twenty-one (88%) patients were considered cured after surgery. Their mean calcium level after surgery was 2.36 ± 0.17 mmol/l. Preoperative FCH PET/CT has a high sensitivity and positive predictive value for parathyroid adenoma detection in patients

  7. F18-choline PET/CT guided surgery in primary hyperparathyroidism when ultrasound and MIBI SPECT/CT are negative or inconclusive. The APACH1 study

    Energy Technology Data Exchange (ETDEWEB)

    Quak, Elske; Lireux, Barbara; Bardet, Stephane [Francois Baclesse Cancer Centre, Department of Nuclear Medicine and Thyroid Unit, Caen (France); Blanchard, David; Raucourt, Dominique de [Francois Baclesse Cancer Centre, Department of Head and Neck Surgery, Caen (France); Houdu, Benjamin [University Hospital, Department of Nuclear Medicine, Caen (France); Le Roux, Yannick [University Hospital, Department of General and Endocrine Surgery, Caen (France); Ciappuccini, Renaud [Francois Baclesse Cancer Centre, Department of Nuclear Medicine and Thyroid Unit, Caen (France); Caen University, INSERM 1086 ANTICIPE, Caen (France); Grellard, Jean-Michel; Licaj, Idlir; Clarisse, Benedicte [Francois Baclesse Cancer Centre, Department of Clinical Research, Caen (France); Reznik, Yves [University Hospital, Department of Endocrinology, Caen (France); Aide, Nicolas [Francois Baclesse Cancer Centre, Department of Nuclear Medicine and Thyroid Unit, Caen (France); University Hospital, Department of Nuclear Medicine, Caen (France); Caen University, INSERM 1086 ANTICIPE, Caen (France)

    2018-04-15

    To evaluate the sensitivity of F18-choline (FCH) PET/CT for parathyroid adenoma detection prior to surgery in patients with primary hyperparathyroidism and negative or inconclusive cervical ultrasound and Tc99m-sestaMIBI SPECT/CT. We conducted a prospective bicentric study (NCT02432599). All patients underwent FCH PET/CT. The result was scored positive, inconclusive or negative. The number of uptakes and their sites were recorded. The FCH PET/CT result guided the surgical procedure (minimally invasive parathyroidectomy, bilateral cervical exploration, or other in case of multiple or ectopic foci). FCH PET/CT results were compared to the surgical and pathological findings and the follow-up. Twenty-five patients were included. Mean calcium and PTH levels prior to surgery were 2.76 ± 0.17 mmol/l and 94.8 ± 37.4 ng/l. Nineteen (76%) FCH PET/CTs were scored positive, 3 (12%) inconclusive and 3 (12%) negative, showing 21 cases of uniglandular disease, including 1 ectopic localization and 1 case of multiglandular (3 foci) disease. Mean lesion size was 13.1 ± 8.6 mm. Twenty-four patients underwent surgery. FCH PET/CT guided surgery in 22 (88%) patients, allowing for 17 minimally invasive parathyroidectomies, 1 bilateral cervical exploration for multifocality and 4 other surgical procedures. Two patients with negative FCH-PET/CT underwent bilateral cervical exploration. When dichotomizing the FCH PET/CT results, thereby classifying the inconclusive FCH PET/CT results as positive, the per lesion and per patient sensitivities were 91.3% (95%CI: 72.0-98.9) and 90.5% (95%CI: 69.6-98.8) and the corresponding positive predictive values were 87.5% (95%CI: 67.6-97.3) and 86.4% (95%CI: 65.1-97.1), respectively. Twenty-one (88%) patients were considered cured after surgery. Their mean calcium level after surgery was 2.36 ± 0.17 mmol/l. Preoperative FCH PET/CT has a high sensitivity and positive predictive value for parathyroid adenoma detection in patients with primary

  8. F18-choline PET/CT guided surgery in primary hyperparathyroidism when ultrasound and MIBI SPECT/CT are negative or inconclusive. The APACH1 study

    International Nuclear Information System (INIS)

    Quak, Elske; Lireux, Barbara; Bardet, Stephane; Blanchard, David; Raucourt, Dominique de; Houdu, Benjamin; Le Roux, Yannick; Ciappuccini, Renaud; Grellard, Jean-Michel; Licaj, Idlir; Clarisse, Benedicte; Reznik, Yves; Aide, Nicolas

    2018-01-01

    To evaluate the sensitivity of F18-choline (FCH) PET/CT for parathyroid adenoma detection prior to surgery in patients with primary hyperparathyroidism and negative or inconclusive cervical ultrasound and Tc99m-sestaMIBI SPECT/CT. We conducted a prospective bicentric study (NCT02432599). All patients underwent FCH PET/CT. The result was scored positive, inconclusive or negative. The number of uptakes and their sites were recorded. The FCH PET/CT result guided the surgical procedure (minimally invasive parathyroidectomy, bilateral cervical exploration, or other in case of multiple or ectopic foci). FCH PET/CT results were compared to the surgical and pathological findings and the follow-up. Twenty-five patients were included. Mean calcium and PTH levels prior to surgery were 2.76 ± 0.17 mmol/l and 94.8 ± 37.4 ng/l. Nineteen (76%) FCH PET/CTs were scored positive, 3 (12%) inconclusive and 3 (12%) negative, showing 21 cases of uniglandular disease, including 1 ectopic localization and 1 case of multiglandular (3 foci) disease. Mean lesion size was 13.1 ± 8.6 mm. Twenty-four patients underwent surgery. FCH PET/CT guided surgery in 22 (88%) patients, allowing for 17 minimally invasive parathyroidectomies, 1 bilateral cervical exploration for multifocality and 4 other surgical procedures. Two patients with negative FCH-PET/CT underwent bilateral cervical exploration. When dichotomizing the FCH PET/CT results, thereby classifying the inconclusive FCH PET/CT results as positive, the per lesion and per patient sensitivities were 91.3% (95%CI: 72.0-98.9) and 90.5% (95%CI: 69.6-98.8) and the corresponding positive predictive values were 87.5% (95%CI: 67.6-97.3) and 86.4% (95%CI: 65.1-97.1), respectively. Twenty-one (88%) patients were considered cured after surgery. Their mean calcium level after surgery was 2.36 ± 0.17 mmol/l. Preoperative FCH PET/CT has a high sensitivity and positive predictive value for parathyroid adenoma detection in patients with primary

  9. Comparable stability of Hoogsteen and Watson-Crick base pairs in ionic liquid choline dihydrogen phosphate.

    Science.gov (United States)

    Tateishi-Karimata, Hisae; Nakano, Miki; Sugimoto, Naoki

    2014-01-08

    The instability of Hoogsteen base pairs relative to Watson-Crick base pairs has limited biological applications of triplex-forming oligonucleotides. Hydrated ionic liquids (ILs) provide favourable environments for a wide range of chemical reactions and are known to impact the stabilities of Watson-Crick base pairs. We found that DNA triplex formation was significantly stabilized in hydrated choline dihydrogen phosphate as compared with an aqueous buffer at neutral pH. Interestingly, the stability of Hoogsteen base pairs was found to be comparable with that of Watson-Crick base pairs in the hydrated IL. Molecular dynamics simulations of a DNA triplex in the presence of choline ions revealed that the DNA triplex was stabilized because of the binding of choline ion around the third strand in the grooves. Our finding will facilitate the development of new DNA materials. Our data also indicate that triplex formation may be stabilized inside cells where choline ions and their derivatives are abundant in vivo.

  10. Comparable Stability of Hoogsteen and Watson–Crick Base Pairs in Ionic Liquid Choline Dihydrogen Phosphate

    Science.gov (United States)

    Tateishi-Karimata, Hisae; Nakano, Miki; Sugimoto, Naoki

    2014-01-01

    The instability of Hoogsteen base pairs relative to Watson–Crick base pairs has limited biological applications of triplex-forming oligonucleotides. Hydrated ionic liquids (ILs) provide favourable environments for a wide range of chemical reactions and are known to impact the stabilities of Watson–Crick base pairs. We found that DNA triplex formation was significantly stabilized in hydrated choline dihydrogen phosphate as compared with an aqueous buffer at neutral pH. Interestingly, the stability of Hoogsteen base pairs was found to be comparable with that of Watson–Crick base pairs in the hydrated IL. Molecular dynamics simulations of a DNA triplex in the presence of choline ions revealed that the DNA triplex was stabilized because of the binding of choline ion around the third strand in the grooves. Our finding will facilitate the development of new DNA materials. Our data also indicate that triplex formation may be stabilized inside cells where choline ions and their derivatives are abundant in vivo. PMID:24399194

  11. Quantitative evaluation of bone metastases from prostate cancer with simultaneous [18F] choline PET/MRI. Combined SUV and ADC analysis

    International Nuclear Information System (INIS)

    Wetter, A.; Lipponer, C.; Nensa, F.; Schlosser, T.W.; Lauenstein, T.C.; Heusch, P.; Ruebben, H.; Poeppel, T.D.; Nagarajah, J.

    2014-01-01

    To quantitatively analyze bone metastases from prostate cancer and correlate the apparent diffusion coefficients (ADCs) and standardized uptake values (SUVs). Fifty-five patients with biopsy-proven prostate cancer or suspected recurrent prostate cancer were examined with simultaneous [ 18 F] choline Positron emission tomography (PET)/MRI at 3 T. In 11 patients, thirty-two PET-positive bone lesions could be identified that were located in the field-of-view of the Diffusion weighted imaging-sequence. Region-of-interest and volume-of-interest analyses were performed to measure the mean and minimal ADCs and to assess maximum and mean SUVs of every bone lesion. Correlations between maximum and mean SUVs and mean and minimal ADCs were calculated. The SUV max of all lesions was 5.5 ± 3.1 (mean ± SD). The SUV mean was 1.8 ± 0.9. The mean ADC (ADC mean ) of all lesions was 0.67 ± 0.13 x 10 -3 mm 2 /s. The minimal ADC (ADC min ) of all lesions was 0.56 ± 0.14 x 10 -3 mm 2 /s. There was a moderate but significant inverse correlation of SUV max vs. ADC mean with a correlation coefficient of -0.4 (p=0.02). There was also a significant inverse correlation of SUV max vs. ADC min with r=-0.41 (p=0.02). Our initial results demonstrate a moderate but significant inverse correlation between increased choline metabolism and ADC values of bone metastases from prostate cancer. Further research on a multimodality approach using simultaneous PET/MRI in bone metastasis of prostate cancer seems to be justified. (author)

  12. Galvanostatic bottom-up filling of TSV-like trenches: Choline-based leveler containing two quaternary ammoniums

    International Nuclear Information System (INIS)

    Kim, Myung Jun; Seo, Youngran; Kim, Hoe Chul; Lee, Yoonjae; Choe, Seunghoe; Kim, Young Gyu; Cho, Sung Ki; Kim, Jae Jeong

    2015-01-01

    Highlights: • The choline-based leveler having two quaternary ammoniums was synthesized. • The adsorption of this leveler with suppressor and accelerator was examined. • Galvanostatic Cu bottom-up filling was achieved with three-additive system. • The mechanism of gap-filling was elucidated based on the additive adsorption. - Abstract: Through Silicon Via (TSV) technology is essential to accomplish 3-dimensional packaging of electronics. Hence, more reliable and faster TSV filling by Cu electrodeposition is required. Our approach to improve Cu gap-filling in TSV is based on the development of new organic additives for feature filling. Here, we introduce our achievements from the synthesis of choline-based leveler to the feature filling using a synthesized leveler. The choline-based leveler, which includes two quaternary ammoniums at both ends of the molecule, is synthesized from glutaric acid. The characteristics of the choline-based additive are examined by the electrochemical analyses, and it is confirmed that the choline-based leveler shows a convection dependent adsorption behavior, which is essential for leveling. The interactions between the polymeric suppressor, accelerator, and the choline-based leveler are also investigated by changing the convection condition. Using the combination of suppressor, accelerator, and the choline-based leveler, the extreme bottom-up filling of Cu at trenches with dimensions similar to TSV are fulfilled. The mechanism of Cu gap-filling is demonstrated based on the results of electrochemical analyses and feature filling

  13. Formulation and utilization of choline based samples for dissolution dynamic nuclear polarization

    DEFF Research Database (Denmark)

    Bowen, Sean; Ardenkjær-Larsen, Jan Henrik

    2013-01-01

    their performance to more traditional sample formulations. Choline yields stable samples with exceptional polarization performance while simultaneously offering the capability to easily remove the choline after dissolution, perform experiments with the hyperpolarized choline, or anything in between....

  14. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    International Nuclear Information System (INIS)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie

    2015-01-01

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  15. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie [Tianjin University of Technology, Tianjin (China)

    2015-10-15

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  16. Prognostic value of 18F-choline PET/CT metabolic parameters in patients with metastatic castration-resistant prostate cancer treated with abiraterone or enzalutamide

    Energy Technology Data Exchange (ETDEWEB)

    Caroli, Paola; Fantini, Lorenzo; Celli, Monica; Paganelli, Giovanni; Matteucci, Federica [Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Nuclear Medicine Unit, Meldola (Italy); De Giorgi, Ugo; Conteduca, Vincenza; Rossi, Lorena [Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Department of Medical Oncology, Meldola (Italy); Scarpi, Emanuela [Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Unit of Biostatistics and Clinical Trials Unit, Meldola (Italy); Moretti, Andrea; Galassi, Riccardo [Morgagni Pierantoni Hospital, Nuclear Medicine Unit, Forli (Italy); Bianchi, Emanuela [Infermi Hospital, Department of Medical Oncology, Rimini (Italy)

    2018-03-15

    The role of 18F-choline positron emission tomography/computed tomography (FCH-PET/CT) in patients with metastatic castration-resistant prostate cancer (mCRPC) has been firmly established in recent years. We analyzed the prognostic value of functional parameters such as mean standardized uptake volume (SUVmean), maximum standardized uptake volume (SUVmax), metabolic total volume (MTV; the volume of interest consisting of all spatially connected voxels within a fixed threshold of 40% of the SUVmax), and total lesion activity (TLA: the product of MTV and mean standardized uptake value) estimated with FCH-PET/CT in mCRPC patients in progression after docetaxel and treated with new antiandrogen receptor therapies, abiraterone or enzalutamide. We retrospectively studied 94 mCRPC patients, mean age 74 years (range 42-90), previously treated with docetaxel who were treated with either abiraterone (n = 52) or enzalutamide (n = 42). An FCH-PET/CT was performed at baseline, and patients were evaluated on a monthly basis for serological PSA response and every 3 months for radiological response. We measured MTV, SUVmean, SUVmax and TLA for each lesion and analyzed the sum of MTV (SMTV), SUVmean (SSUVmean), SUVmax (SSUVmax) and TLA (STLA) values for a maximum of 20 lesions. Univariate analysis was used to correlate these data with PFS and OS. We observed a median SMTV of 130 cm{sup 3}, median SSUVmax of 106.5 and a median STLA of 495,070. All of these parameters were significant for PFS and OS in univariate analysis, while only STLA was significant for PFS and OS in multivariate analysis after adjusting for lesion and age (p < 0.0001 and p = 0.001, respectively). Baseline PSA values maintained a certain reliability for OS (p = 0.034). Semiquantitative parameters of FCH-PET/CT play a prognostic role in mCRCP patients treated with abiraterone or enzalutamide. (orig.)

  17. Magnetic Resonance-based Motion Correction for Quantitative PET in Simultaneous PET-MR Imaging.

    Science.gov (United States)

    Rakvongthai, Yothin; El Fakhri, Georges

    2017-07-01

    Motion degrades image quality and quantitation of PET images, and is an obstacle to quantitative PET imaging. Simultaneous PET-MR offers a tool that can be used for correcting the motion in PET images by using anatomic information from MR imaging acquired concurrently. Motion correction can be performed by transforming a set of reconstructed PET images into the same frame or by incorporating the transformation into the system model and reconstructing the motion-corrected image. Several phantom and patient studies have validated that MR-based motion correction strategies have great promise for quantitative PET imaging in simultaneous PET-MR. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Influence of PSA, PSA velocity and PSA doubling time on contrast-enhanced 18F-choline PET/CT detection rate in patients with rising PSA after radical prostatectomy

    International Nuclear Information System (INIS)

    Schillaci, Orazio; Calabria, Ferdinando; Tavolozza, Mario; Caracciolo, Cristiana Ragano; Orlacchio, Antonio; Danieli, Roberta; Simonetti, Giovanni; Agro, Enrico Finazzi; Miano, Roberto

    2012-01-01

    To evaluate the accuracy of contrast-enhanced 18 F-choline PET/CT in restaging patients with prostate cancer after radical prostatectomy in relation to PSA, PSA velocity (PSAve) and PSA doubling time (PSAdt). PET/CT was performed in 49 patients (age range 58-87 years) with rising PSA (mean 4.13 ng/ml) who were divided in four groups according to PSA level: ≤1 ng/ml, 1 to ≤2 ng/ml, 2 to ≤4 ng/ml, and >4 ng/ml. PSAve and PSAdt were measured. PET and CT scans were interpreted separately and then together. PET/CT diagnosed relapse in 33 of the 49 patients (67%). The detection rates were 20%, 55%, 80% and 87% in the PSA groups ≤1, 1 to ≤2, 2 to ≤4 and >4 ng/ml, respectively. PET/CT was positive in 7 of 18 patients (38.9%) with a PSA ≤2 ng/ml, and in 26 of 31 (83.9%) with a PSA >2 ng/ml. PET/CT was positive in 7 of 25 patients (84%) with PSAdt ≤6 months, and in 12 of 24 patients (50%) with PSAdt >6 months, and was positive in 26 of 30 patients (86%) with a PSAve >2 ng/ml per year, and in 7 of 19 patients (36.8%) with PSAve ≤2 ng/ml per year. PET alone was positive in 31 of 49 patients (63.3%), and of these 31 patients, CT was negative in 14 but diagnosed bone lesions in 2 patients in whom PET alone was negative. CT with the administration of intravenous contrast medium did not provide any further information. Detection rate of 18 F-choline imaging is closely related to PSA and PSA kinetics. In particular, 18 F-choline PET/CT is recommended in patients with PSA >2 ng/ml, PSAdt ≤6 months and PSAve >2 ng/ml per year. CT is useful for detecting bone metastases that are not 18 F-choline-avid. The use of intravenous contrast agent seems unnecessary. (orig.)

  19. Influence of PSA, PSA velocity and PSA doubling time on contrast-enhanced {sup 18}F-choline PET/CT detection rate in patients with rising PSA after radical prostatectomy

    Energy Technology Data Exchange (ETDEWEB)

    Schillaci, Orazio [University ' ' Tor Vergata' ' , Department of Biopathology and Diagnostic Imaging, Interventional, Rome (Italy); IRCCS Neuromed, Department of Nuclear Medicine and Molecular Imaging, Pozzilli (Italy); Calabria, Ferdinando [IRCCS Neuromed, Department of Nuclear Medicine and Molecular Imaging, Pozzilli (Italy); Tavolozza, Mario; Caracciolo, Cristiana Ragano; Orlacchio, Antonio; Danieli, Roberta; Simonetti, Giovanni [University ' ' Tor Vergata' ' , Department of Biopathology and Diagnostic Imaging, Interventional, Rome (Italy); Agro, Enrico Finazzi; Miano, Roberto [University Hospital ' ' Tor Vergata' ' , Department of Urology, Rome (Italy)

    2012-04-15

    To evaluate the accuracy of contrast-enhanced {sup 18}F-choline PET/CT in restaging patients with prostate cancer after radical prostatectomy in relation to PSA, PSA velocity (PSAve) and PSA doubling time (PSAdt). PET/CT was performed in 49 patients (age range 58-87 years) with rising PSA (mean 4.13 ng/ml) who were divided in four groups according to PSA level: {<=}1 ng/ml, 1 to {<=}2 ng/ml, 2 to {<=}4 ng/ml, and >4 ng/ml. PSAve and PSAdt were measured. PET and CT scans were interpreted separately and then together. PET/CT diagnosed relapse in 33 of the 49 patients (67%). The detection rates were 20%, 55%, 80% and 87% in the PSA groups {<=}1, 1 to {<=}2, 2 to {<=}4 and >4 ng/ml, respectively. PET/CT was positive in 7 of 18 patients (38.9%) with a PSA {<=}2 ng/ml, and in 26 of 31 (83.9%) with a PSA >2 ng/ml. PET/CT was positive in 7 of 25 patients (84%) with PSAdt {<=}6 months, and in 12 of 24 patients (50%) with PSAdt >6 months, and was positive in 26 of 30 patients (86%) with a PSAve >2 ng/ml per year, and in 7 of 19 patients (36.8%) with PSAve {<=}2 ng/ml per year. PET alone was positive in 31 of 49 patients (63.3%), and of these 31 patients, CT was negative in 14 but diagnosed bone lesions in 2 patients in whom PET alone was negative. CT with the administration of intravenous contrast medium did not provide any further information. Detection rate of {sup 18}F-choline imaging is closely related to PSA and PSA kinetics. In particular, {sup 18}F-choline PET/CT is recommended in patients with PSA >2 ng/ml, PSAdt {<=}6 months and PSAve >2 ng/ml per year. CT is useful for detecting bone metastases that are not {sup 18}F-choline-avid. The use of intravenous contrast agent seems unnecessary. (orig.)

  20. Current evaluation of the clinical utility of fluoromethyl choline-(18F) PET/CT in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Talbot, Jean-Noel [Hopital Tenon AP-HP, Paris (France); Universite Pierre et Marie Curie, Paris (France); E-mail: jean-noel.talbot@tnn.ap-hop-paris.fr; Chevalme, Yanna-Marina [Agence Francaise de Securite Sanitaire des Produits de Sante (AFSSAPS), St Denis (France)

    2008-12-15

    This short review is dedicated to the current status of the assessment of a new PET radiopharmaceutical, fluoromethylcholine-(18F) or FCH, which is taken-up by prostate cancer tissue, in contrary to fluorodeoxyglucose- (18F) or FDG. It seems that FCH could become 'the FDG of prostate cancer', with the same type of achievements (detection of distant metastases and of occult recurrences, restaging prior to invasive treatments), and the same drawbacks (false negative results in case of small lesions, in particular lymph nodes metastases, and false positive results in case of infection/inflammation, in particular prostatitis). Current evidence is summarised and discussed for each of the potential settings of FCH PET/CT imaging in prostate cancer. The perspectives for granting a marketing authorisation to a FCH preparation are briefly analysed. (author)

  1. Electrochemical synthesis of nanosized TiO2 nanopowder involving choline chloride based ionic liquids

    International Nuclear Information System (INIS)

    Anicai, Liana; Petica, Aurora; Patroi, Delia; Marinescu, Virgil; Prioteasa, Paula; Costovici, Stefania

    2015-01-01

    Highlights: • TiO 2 nanopowder electrochemically prepared using choline chloride based ionic liquids. • The new proposed method allowed high anodic synthesis efficiencies of minimum 92%. • High surface area of the electrochemically synthesized titania nanopowders. • Enhanced photocatalytic activity. - Abstract: The paper presents some experimental results regarding the electrochemical synthesis of TiO 2 nanopowders through anodic dissolution of Ti metal in choline chloride based eutectic mixtures (DES). A detailed characterization of the obtained titania has been performed, using various techniques, including XRD, Raman spectroscopy, XPS, SEM associated with EDX analysis, BET and UV–vis diffuse reflectance spectra. The anodic behavior of Ti electrode in DES has been also investigated. The photoreactivity of the synthesized materials was evaluated for the degradation of Orange II dye under UV (λ = 365 nm) and visible light irradiation. An anodic synthesis efficiency of minimum 92% has been determined. The as-synthesized TiO 2 showed amorphous structure and a calcination post-treatment at temperatures between 400 and 600 °C yielded anatase. The anodically obtained nanocrystalline oxides have crystallite sizes of 8–18 nm, a high surface area and enhanced photocatalytic effect

  2. Electrochemical synthesis of nanosized TiO{sub 2} nanopowder involving choline chloride based ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Anicai, Liana, E-mail: lanicai@itcnet.ro [POLITEHNICA University of Bucharest, Center of Surface Science and Nanotechnology, Splaiul Independentei 313, Bucharest, 060042 (Romania); Petica, Aurora [Leather and Footwear Research Institute (ICPI), Ion Minulescu 93, Bucharest, 031215 (Romania); Patroi, Delia; Marinescu, Virgil; Prioteasa, Paula [INCDIE ICPE-Advanced Research, Splaiul Unirii 313, Bucharest (Romania); Costovici, Stefania [POLITEHNICA University of Bucharest, Center of Surface Science and Nanotechnology, Splaiul Independentei 313, Bucharest, 060042 (Romania)

    2015-09-15

    Highlights: • TiO{sub 2} nanopowder electrochemically prepared using choline chloride based ionic liquids. • The new proposed method allowed high anodic synthesis efficiencies of minimum 92%. • High surface area of the electrochemically synthesized titania nanopowders. • Enhanced photocatalytic activity. - Abstract: The paper presents some experimental results regarding the electrochemical synthesis of TiO{sub 2} nanopowders through anodic dissolution of Ti metal in choline chloride based eutectic mixtures (DES). A detailed characterization of the obtained titania has been performed, using various techniques, including XRD, Raman spectroscopy, XPS, SEM associated with EDX analysis, BET and UV–vis diffuse reflectance spectra. The anodic behavior of Ti electrode in DES has been also investigated. The photoreactivity of the synthesized materials was evaluated for the degradation of Orange II dye under UV (λ = 365 nm) and visible light irradiation. An anodic synthesis efficiency of minimum 92% has been determined. The as-synthesized TiO{sub 2} showed amorphous structure and a calcination post-treatment at temperatures between 400 and 600 °C yielded anatase. The anodically obtained nanocrystalline oxides have crystallite sizes of 8–18 nm, a high surface area and enhanced photocatalytic effect.

  3. Comparing life cycle energy and GHG emissions of bio-based PET, recycled PET, PLA and man-made cellulosics

    NARCIS (Netherlands)

    Shen, L.; Worrell, E.; Patel, M.K.

    2012-01-01

    The purpose of this paper is to review the environmental profiles of petrochemical PET, (partially) bio-based PET, recycled PET, and recycled (partially) bio-based PET, and compare them with other bio-based materials, namely PLA (polylactic acid, a bio-based polyester) and man-made cellulose

  4. Electrodeposition of copper composites from deep eutectic solvents based on choline chloride.

    Science.gov (United States)

    Abbott, Andrew P; El Ttaib, Khalid; Frisch, Gero; McKenzie, Katy J; Ryder, Karl S

    2009-06-07

    Here we describe for the first time the electrolytic deposition of copper and copper composites from a solution of the metal chloride salt in either urea-choline chloride, or ethylene glycol-choline chloride based eutectics. We show that the deposition kinetics and thermodynamics are quite unlike those in aqueous solution under comparable conditions and that the copper ion complexation is also different. The mechanism of copper nucleation is studied using chronoamperometry and it is shown that progressive nucleation leads to a bright nano-structured deposit. In contrast, instantaneous nucleation, at lower concentrations of copper ions, leads to a dull deposit. This work also pioneers the use of the electrochemical quartz crystal microbalance (EQCM) to monitor both current efficiency and the inclusion of inert particulates into the copper coatings. This technique allows the first in situ quantification or particulate inclusion. It was found that the composition of composite material was strongly dependent on the amount of species suspended in solution. It was also shown that the majority of material was dragged onto the surface rather than settling on to it. The distribution of the composite material was found to be even throughout the coating. This technology is important because it facilitates deposition of bright copper coatings without co-ligands such as cyanide. The incorporation of micron-sized particulates into ionic liquids has resulted, in one case, in a decrease in viscosity. This observation is both unusual and surprising; we explain this here in terms of an increase in the free volume of the liquid and local solvent perturbation.

  5. Qualification test of a MPPC-based PET module for future MRI-PET scanners

    Science.gov (United States)

    Kurei, Y.; Kataoka, J.; Kato, T.; Fujita, T.; Funamoto, H.; Tsujikawa, T.; Yamamoto, S.

    2014-11-01

    We have developed a high-resolution, compact Positron Emission Tomography (PET) module for future use in MRI-PET scanners. The module consists of large-area, 4×4 ch MPPC arrays (Hamamatsu S11827-3344MG) optically coupled with Ce:LYSO scintillators fabricated into 12×12 matrices of 1×1 mm2 pixels. At this stage, a pair of module and coincidence circuits was assembled into an experimental prototype gantry arranged in a ring of 90 mm in diameter to form the MPPC-based PET system. The PET detector ring was then positioned around the RF coil of the 4.7 T MRI system. We took an image of a point 22Na source under fast spin echo (FSE) and gradient echo (GE), in order to measure interference between the MPPC-based PET and the MRI. We only found a slight degradation in the spatial resolution of the PET image from 1.63 to 1.70 mm (FWHM; x-direction), or 1.48-1.55 mm (FWHM; y-direction) when operating with the MRI, while the signal-to-noise ratio (SNR) of the MRI image was only degraded by 5%. These results encouraged us to develop a more advanced version of the MRI-PET gantry with eight MPPC-based PET modules, whose detailed design and first qualification test are also presented in this paper.

  6. PeneloPET, a Monte Carlo PET simulation tool based on PENELOPE: features and validation

    Energy Technology Data Exchange (ETDEWEB)

    Espana, S; Herraiz, J L; Vicente, E; Udias, J M [Grupo de Fisica Nuclear, Departmento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, Madrid (Spain); Vaquero, J J; Desco, M [Unidad de Medicina y CirugIa Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain)], E-mail: jose@nuc2.fis.ucm.es

    2009-03-21

    Monte Carlo simulations play an important role in positron emission tomography (PET) imaging, as an essential tool for the research and development of new scanners and for advanced image reconstruction. PeneloPET, a PET-dedicated Monte Carlo tool, is presented and validated in this work. PeneloPET is based on PENELOPE, a Monte Carlo code for the simulation of the transport in matter of electrons, positrons and photons, with energies from a few hundred eV to 1 GeV. PENELOPE is robust, fast and very accurate, but it may be unfriendly to people not acquainted with the FORTRAN programming language. PeneloPET is an easy-to-use application which allows comprehensive simulations of PET systems within PENELOPE. Complex and realistic simulations can be set by modifying a few simple input text files. Different levels of output data are available for analysis, from sinogram and lines-of-response (LORs) histogramming to fully detailed list mode. These data can be further exploited with the preferred programming language, including ROOT. PeneloPET simulates PET systems based on crystal array blocks coupled to photodetectors and allows the user to define radioactive sources, detectors, shielding and other parts of the scanner. The acquisition chain is simulated in high level detail; for instance, the electronic processing can include pile-up rejection mechanisms and time stamping of events, if desired. This paper describes PeneloPET and shows the results of extensive validations and comparisons of simulations against real measurements from commercial acquisition systems. PeneloPET is being extensively employed to improve the image quality of commercial PET systems and for the development of new ones.

  7. PeneloPET, a Monte Carlo PET simulation tool based on PENELOPE: features and validation

    International Nuclear Information System (INIS)

    Espana, S; Herraiz, J L; Vicente, E; Udias, J M; Vaquero, J J; Desco, M

    2009-01-01

    Monte Carlo simulations play an important role in positron emission tomography (PET) imaging, as an essential tool for the research and development of new scanners and for advanced image reconstruction. PeneloPET, a PET-dedicated Monte Carlo tool, is presented and validated in this work. PeneloPET is based on PENELOPE, a Monte Carlo code for the simulation of the transport in matter of electrons, positrons and photons, with energies from a few hundred eV to 1 GeV. PENELOPE is robust, fast and very accurate, but it may be unfriendly to people not acquainted with the FORTRAN programming language. PeneloPET is an easy-to-use application which allows comprehensive simulations of PET systems within PENELOPE. Complex and realistic simulations can be set by modifying a few simple input text files. Different levels of output data are available for analysis, from sinogram and lines-of-response (LORs) histogramming to fully detailed list mode. These data can be further exploited with the preferred programming language, including ROOT. PeneloPET simulates PET systems based on crystal array blocks coupled to photodetectors and allows the user to define radioactive sources, detectors, shielding and other parts of the scanner. The acquisition chain is simulated in high level detail; for instance, the electronic processing can include pile-up rejection mechanisms and time stamping of events, if desired. This paper describes PeneloPET and shows the results of extensive validations and comparisons of simulations against real measurements from commercial acquisition systems. PeneloPET is being extensively employed to improve the image quality of commercial PET systems and for the development of new ones.

  8. Fully automated SPE-based synthesis and purification of 2-[{sup 18}F]fluoroethyl-choline for human use

    Energy Technology Data Exchange (ETDEWEB)

    Schmaljohann, Joern [Department of Nuclear Medicine, University of Bonn, Bonn (Germany); Department of Nuclear Medicine, University of Aachen, Aachen (Germany); Schirrmacher, Esther [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec (Canada); Waengler, Bjoern; Waengler, Carmen [Department of Nuclear Medicine, Ludwig-Maximilians University, Munich (Germany); Schirrmacher, Ralf, E-mail: ralf.schirrmacher@mcgill.c [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec (Canada); Guhlke, Stefan, E-mail: stefan.guhlke@ukb.uni-bonn.d [Department of Nuclear Medicine, University of Bonn, Bonn (Germany)

    2011-02-15

    Introduction: 2-[{sup 18}F]Fluoroethyl-choline ([{sup 18}F]FECH) is a promising tracer for the detection of prostate cancer as well as brain tumors with positron emission tomography (PET). [{sup 18}F]FECH is actively transported into mammalian cells, becomes phosphorylated by choline kinase and gets incorporated into the cell membrane after being metabolized to phosphatidylcholine. So far, its synthesis is a two-step procedure involving at least one HPLC purification step. To allow a wider dissemination of this tracer, finding a purification method avoiding HPLC is highly desirable and would result in easier accessibility and more reliable production of [{sup 18}F]FECH. Methods: [{sup 18}F]FECH was synthesized by reaction of 2-bromo-1-[{sup 18}F]fluoroethane ([{sup 18}F]BFE) with dimethylaminoethanol (DMAE) in DMSO. We applied a novel and very reliable work-up procedure for the synthesis of [{sup 18}F]BFE. Based on a combination of three different solid-phase cartridges, the purification of [{sup 18}F]BFE from its precursor 2-bromoethyl-4-nitrobenzenesulfonate (BENos) could be achieved without using HPLC. Following the subsequent reaction of the purified [{sup 18}F]BFE with DMAE, the final product [{sup 18}F]FECH was obtained as a sterile solution by passing the crude reaction mixture through a combination of two CM plus cartridges and a sterile filter. The fully automated synthesis was performed using as well a Raytest SynChrom module (Raytest, Germany) or a Scintomics HotboxIII module (Scintomics, Germany). Results: The radiotracer [{sup 18}F]FECH can be synthesized in reliable radiochemical yields (RCY) of 37{+-}5% (Synchrom module) and 33{+-}5% (Hotbox III unit) in less than 1 h using these two fully automated commercially available synthesis units without HPLC involvement for purification. Detailed quality control of the final injectable [{sup 18}F]FECH solution proved the high radiochemical purity and the absence of Kryptofix2.2.2, DMAE and DMSO used in the

  9. Novel Small Molecule Inhibitors of Choline Kinase Identified by Fragment-Based Drug Discovery.

    Science.gov (United States)

    Zech, Stephan G; Kohlmann, Anna; Zhou, Tianjun; Li, Feng; Squillace, Rachel M; Parillon, Lois E; Greenfield, Matthew T; Miller, David P; Qi, Jiwei; Thomas, R Mathew; Wang, Yihan; Xu, Yongjin; Miret, Juan J; Shakespeare, William C; Zhu, Xiaotian; Dalgarno, David C

    2016-01-28

    Choline kinase α (ChoKα) is an enzyme involved in the synthesis of phospholipids and thereby plays key roles in regulation of cell proliferation, oncogenic transformation, and human carcinogenesis. Since several inhibitors of ChoKα display antiproliferative activity in both cellular and animal models, this novel oncogene has recently gained interest as a promising small molecule target for cancer therapy. Here we summarize our efforts to further validate ChoKα as an oncogenic target and explore the activity of novel small molecule inhibitors of ChoKα. Starting from weakly binding fragments, we describe a structure based lead discovery approach, which resulted in novel highly potent inhibitors of ChoKα. In cancer cell lines, our lead compounds exhibit a dose-dependent decrease of phosphocholine, inhibition of cell growth, and induction of apoptosis at low micromolar concentrations. The druglike lead series presented here is optimizable for improvements in cellular potency, drug target residence time, and pharmacokinetic parameters. These inhibitors may be utilized not only to further validate ChoKα as antioncogenic target but also as novel chemical matter that may lead to antitumor agents that specifically interfere with cancer cell metabolism.

  10. Toxicity profile of choline chloride-based deep eutectic solvents for fungi and Cyprinus carpio fish.

    Science.gov (United States)

    Juneidi, Ibrahim; Hayyan, Maan; Mohd Ali, Ozair

    2016-04-01

    An investigation on the toxicological assessment of 10 choline chloride (ChCl)-based deep eutectic solvents (DESs) towards four fungi strains and Cyprinus carpio fish was conducted. ChCl was combined with materials from different chemical groups such as alcohols, sugars, acids and others to form DESs. The study was carried out on the individual DES components, their aqueous mixture before DES formation and their formed DESs. The agar disc diffusion method was followed to investigate their toxicity on four fungi strains selected as a model of eukaryotic microorganisms (Phanerochaete chrysosporium, Aspergillus niger, Lentinus tigrinus and Candida cylindracea). Among these DESs, ChCl:ZnCl2 exhibited the highest inhibition zone diameter towards the tested fungi growth in vitro, followed by the acidic group (malonic acid and p-toluenesulfonic acid). Another study was conducted to test the acute toxicity and determine the lethal concentration at 50 % (LC50) of the same DESs on C. carpio fish. The inhibition range and LC50 of DESs were found to be different from their individual components. DESs were found to be less toxic than their mixture or individual components. The LC50 of ChCl:MADES is much higher than that of ChCl:MAMix. Moreover, the DESs acidic group showed a lower inhibition zone on fungi growth. Thus, DESs should be considered as new components with different physicochemical properties and toxicological profiles, and not merely compositions of compounds.

  11. The physicochemical and thermodynamic properties of the choline chloride-based deep eutectic solvents

    Directory of Open Access Journals (Sweden)

    Troter Dragan Z.

    2017-01-01

    Full Text Available This paper reports the physicochemical (density, dynamic viscosity, electrical conductivity and refractive index and the thermodynamic (thermal expansion coefficient, molecular volume, lattice energy and heat capacity properties of several choline chloride (ChCl based deep eutectic solvents (DESs, with 1:2 mole ratio, respectively: ChCl:propylene glycol, ChCl:1,3-dimethylurea and ChCl:thiourea, at atmospheric pressure as a function of temperature over the range of 293.15–363.15 K. Their properties were also compared with those of some already characterized ChCl-based DESs, namely ChCl:ethylene glycol, ChCl:glycerol and ChCl:urea (1:2 mole ratio. Density, viscosity and refractive index of all DESs decrease with the increasing temperature while the electrical conductivity increases. Viscosity and conductivity of the tested DESs were fitted by both Arrhenius-type and Vogel–Tamman–Fulcher equations. The changes of molar enthalpy, entropy and Gibbs energy of activation, determined using the Eyring theory, demonstrated the interactional factor as predominant over the structural factor for all DES systems. The fractional Walden rule, used to correlate molar conductivity and viscosity, showed an excellent linear behaviour. It was shown that ChCl:propylene glycol DES had properties similar to ChCl:ethylene glycol and ChCl:glycerol DESs. However, the properties (density, viscosity and electrical conductivity of ChCl:1,3-dimethylurea and ChCl: :thiourea DESs were inferior to those of the ChCl:urea DES. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 45001

  12. Gastrin-releasing peptide receptor-based targeting using bombesin analogues is superior to metabolism-based targeting using choline for in vivo imaging of human prostate cancer xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Rogier P.J. [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Erasmus MC, Department of Urology, Rotterdam (Netherlands); Weerden, W.M. van; Bangma, C.H.; Reneman, S. [Erasmus MC, Department of Urology, Rotterdam (Netherlands); Krenning, E.P.; Berndsen, S.; Grievink-de Ligt, C.H.; Groen, H.C.; Blois, E. de; Breeman, W.A.P.; Jong, M. de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands)

    2011-07-15

    Prostate cancer (PC) is a major health problem. Overexpression of the gastrin-releasing peptide receptor (GRPR) in PC, but not in the hyperplastic prostate, provides a promising target for staging and monitoring of PC. Based on the assumption that cancer cells have increased metabolic activity, metabolism-based tracers are also being used for PC imaging. We compared GRPR-based targeting using the {sup 68}Ga-labelled bombesin analogue AMBA with metabolism-based targeting using {sup 18}F-methylcholine ({sup 18}F-FCH) in nude mice bearing human prostate VCaP xenografts. PET and biodistribution studies were performed with both {sup 68}Ga-AMBA and {sup 18}F-FCH in all VCaP tumour-bearing mice, with PC-3 tumour-bearing mice as reference. Scanning started immediately after injection. Dynamic PET scans were reconstructed and analysed quantitatively. Biodistribution of tracers and tissue uptake was expressed as percent of injected dose per gram tissue (%ID/g). All tumours were clearly visualized using {sup 68}Ga-AMBA. {sup 18}F-FCH showed significantly less contrast due to poor tumour-to-background ratios. Quantitative PET analyses showed fast tumour uptake and high retention for both tracers. VCaP tumour uptake values determined from PET at steady-state were 6.7 {+-} 1.4%ID/g (20-30 min after injection, N = 8) for {sup 68}Ga-AMBA and 1.6 {+-} 0.5%ID/g (10-20 min after injection, N = 8) for {sup 18}F-FCH, which were significantly different (p <0.001). The results in PC-3 tumour-bearing mice were comparable. Biodistribution data were in accordance with the PET results showing VCaP tumour uptake values of 9.5 {+-} 4.8%ID/g (N = 8) for {sup 68}Ga-AMBA and 2.1 {+-} 0.4%ID/g (N = 8) for {sup 18}F-FCH. Apart from the GRPR-expressing organs, uptake in all organs was lower for {sup 68}Ga-AMBA than for {sup 18}F-FCH. Tumour uptake of {sup 68}Ga-AMBA was higher while overall background activity was lower than observed for {sup 18}F-FCH in the same PC-bearing mice. These results

  13. PET

    DEFF Research Database (Denmark)

    Mariager, Rasmus Mølgaard; Schmidt, Regin; Heiberg, Morten Rievers

    PET handler om den hemmelige tjenestes arbejde under den kolde krig 1945-1989. Her fortæller Regin Schmidt, Rasmus Mariager og Morten Heiberg om de mest dramatiske og interessante sager fra PET's arkiv. PET er på flere måder en udemokratisk institution, der er sat til at vogte over demokratiet....... Dens virksomhed er skjult for offentligheden, den overvåger borgernes aktiviteter, og den registrerer følsomme personoplysninger. Historien om PET rejser spørgsmålet om, hvad man skal gøre, når befolkningen i et demokrati er kritisk indstillet over for overvågningen af lovlige politiske aktiviteter......, mens myndighederne mener, at det er nødvendigt for at beskytte demokratiet. PET er på en gang en fortælling om konkrete aktioner og begivenheder i PET's arbejde og et stykke Danmarkshistorie. Det handler om overvågning, spioner, politisk ekstremisme og international terrorisme.  ...

  14. Toxicity and quality of life after choline-PET/CT directed salvage lymph node dissection and adjuvant radiotherapy in nodal recurrent prostate cancer

    International Nuclear Information System (INIS)

    Jilg, Cordula A; Leifert, Anja; Schnell, Daniel; Kirste, Simon; Volegova-Neher, Natalia; Schlager, Daniel; Wieser, Gesche; Henne, Karl; Schultze-Seemann, Wolfgang; Grosu, Anca-L; Rischke, Hans Christian

    2014-01-01

    In a previous study we demonstrated that, based on 11 C/ 18 F-choline positron emission tomography-computerized-tomography as a diagnostic tool, salvage lymph node dissection (LND) plus adjuvant radiotherapy (ART) is feasible for treatment of pelvic/retroperitoneal nodal recurrence of prostate cancer (PCa). However, the toxicity of this combined treatment strategy has not been systematically investigated before. The aim of the current study was to evaluate the acute and late toxicity and quality of life of ART after LND in pelvic/retroperitoneal nodal recurrent PCa. 43 patients with nodal recurrent PCa were treated with 46 LND followed by ART (mean 49.6 Gy total dose) at the sites of nodal recurrence. Toxicity of ART was analysed by physically examination (31/43, 72.1%), by requesting 15 frequent items of adverse events from the Common-Terminology-Criteria for Adverse Events Version 4.0-catalogue and by review of medical records. QLQ-C30 (EORTC quality of life assessment) and PR25 (prostate cancer module) questionnaires were used to investigate quality of life. Toxicity was evaluated before starting of ART, during ART (acute toxicity), after ART (mean 2.3 months) and at end of follow up (mean 3.2 years after end of ART) reflecting late toxicity. 71.7% (33/46) of 46 ART were treatment of pelvic, 10.9% (5/46) of retroperitoneal only and 28.3% (13/46) of pelvic and retroperitoneal regions. Overall 52 symptoms representing toxicities were observed before ART, 107 during ART, 88 after end of ART and 52 at latest follow up. Leading toxicities during ART were diarrhoea (19%, 20/107), urinary incontinence (16%, 17/107) and fatigue (16%, 17/107). The spectrum of late toxicities was almost equal to those before beginning of ART. No grade 3 adverse events or chronic lymphedema at extremities were observed. We observed no clear correlation between localisation of treated regions, technique of ART and frequency or severity of toxicities. Mean quality of life at final evaluation

  15. Filtered backprojection algorithm in RPCs based PET

    International Nuclear Information System (INIS)

    Cruceru, Ilie; Manea Ioana; Nicorescu, Carmen; Constantin Florin

    2003-01-01

    The basis of PET consists in administration of a radioactive isotope attached to a tracer that permits to reveal its molecular pathways in the human body. A 3-D Whole-Body-Scan is necessary in order to minimize the radiation exposure of the patient and to increase significantly the axial field of view (FOV). A major candidate for gamma pair detection in 3-D Whole-Body-Scan appear to be the RPCs (Resistive Plate Counters). They consist in a longitudinal microstrip grid 15 mm thick, spaced at 1 mm; the grid is placed between a large electric resistive glass anode (ρ = 10 12 Ωcm) and an aluminium cathode; the gap of around 300 μm is filled with a special gas and is polarized at around 6 kV. Several detecting structures based on Resistive Plate Counters (RPCs) are evaluated for use in a positron emission 3-Dimensional Whole-Body-Scan tomograph. The coincidence matrix is built for the specific detecting structure by means of random gamma pair ray generation and then the filtered backprojection algorithm is used to reconstruct the original picture. The accuracy of image reconstruction is examined for the four different detecting structures. (authors)

  16. Interference between PET and MRI sub-systems in a silicon-photomultiplier-based PET/MRI system

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Watabe, Hiroshi; Kanai, Yasukazu; Hatazawa, Jun; Aoki, Masaaki; Sugiyama, Eiji; Watabe, Tadashi; Imaizumi, Masao; Shimosegawa, Eku

    2011-01-01

    The silicon-photomultiplier (Si-PM) is a promising photodetector, especially for integrated PET/MRI systems, due to its small size, high gain, and low sensitivity to static magnetic fields. The major problem using a Si-PM-based PET system within the MRI system is the interference between the PET and MRI units. We measured the interference by combining a Si-PM-based PET system with a permanent-magnet MRI system. When the RF signal-induced pulse height exceeded the lower energy threshold level of the PET system, interference between the Si-PM-based PET system and MRI system was detected. The prompt as well as the delayed coincidence count rates of the Si-PM-based PET system increased significantly. These noise counts produced severe artifacts on the reconstructed images of the Si-PM-based PET system. In terms of the effect of the Si-PM-based PET system on the MRI system, although no susceptibility artifact was observed on the MR images, electronic noise from the PET detector ring was detected by the RF coil and reduced the signal-to-noise ratio (S/N) of the MR images. The S/N degradation of the MR images was reduced when the distance between the RF coil and the Si-PM-based PET system was increased. We conclude that reducing the interference between the PET and MRI systems is essential for achieving the optimum performance of integrated Si-PM PET/MRI systems.

  17. PET/CT Based Dose Planning in Radiotherapy

    DEFF Research Database (Denmark)

    Berthelsen, Anne Kiil; Jakobsen, Annika Loft; Sapru, Wendy

    2011-01-01

    radiotherapy planning with PET/CT prior to the treatment. The PET/CT, including the radiotherapy planning process as well as the radiotherapy process, is outlined in detail. The demanding collaboration between mould technicians, nuclear medicine physicians and technologists, radiologists and radiology......This mini-review describes how to perform PET/CT based radiotherapy dose planning and the advantages and possibilities obtained with the technique for radiation therapy. Our own experience since 2002 is briefly summarized from more than 2,500 patients with various malignant diseases undergoing...... technologists, radiation oncologists, physicists, and dosimetrists is emphasized. We strongly believe that PET/CT based radiotherapy planning will improve the therapeutic output in terms of target definition and non-target avoidance and will play an important role in future therapeutic interventions in many...

  18. Model-based image reconstruction for four-dimensional PET

    International Nuclear Information System (INIS)

    Li Tianfang; Thorndyke, Brian; Schreibmann, Eduard; Yang Yong; Xing Lei

    2006-01-01

    Positron emission tonography (PET) is useful in diagnosis and radiation treatment planning for a variety of cancers. For patients with cancers in thoracic or upper abdominal region, the respiratory motion produces large distortions in the tumor shape and size, affecting the accuracy in both diagnosis and treatment. Four-dimensional (4D) (gated) PET aims to reduce the motion artifacts and to provide accurate measurement of the tumor volume and the tracer concentration. A major issue in 4D PET is the lack of statistics. Since the collected photons are divided into several frames in the 4D PET scan, the quality of each reconstructed frame degrades as the number of frames increases. The increased noise in each frame heavily degrades the quantitative accuracy of the PET imaging. In this work, we propose a method to enhance the performance of 4D PET by developing a new technique of 4D PET reconstruction with incorporation of an organ motion model derived from 4D-CT images. The method is based on the well-known maximum-likelihood expectation-maximization (ML-EM) algorithm. During the processes of forward- and backward-projection in the ML-EM iterations, all projection data acquired at different phases are combined together to update the emission map with the aid of deformable model, the statistics is therefore greatly improved. The proposed algorithm was first evaluated with computer simulations using a mathematical dynamic phantom. Experiment with a moving physical phantom was then carried out to demonstrate the accuracy of the proposed method and the increase of signal-to-noise ratio over three-dimensional PET. Finally, the 4D PET reconstruction was applied to a patient case

  19. PET-based molecular imaging in neuroscience

    International Nuclear Information System (INIS)

    Jacobs, A.H.; Heiss, W.D.; Li, H.; Knoess, C.; Schaller, B.; Kracht, L.; Monfared, P.; Vollmar, S.; Bauer, B.; Wagner, R.; Graf, R.; Wienhard, K.; Winkeler, A.; Rueger, A.; Klein, M.; Hilker, R.; Galldiks, N.; Herholz, K.; Sobesky, J.

    2003-01-01

    Positron emission tomography (PET) allows non-invasive assessment of physiological, metabolic and molecular processes in humans and animals in vivo. Advances in detector technology have led to a considerable improvement in the spatial resolution of PET (1-2 mm), enabling for the first time investigations in small experimental animals such as mice. With the developments in radiochemistry and tracer technology, a variety of endogenously expressed and exogenously introduced genes can be analysed by PET. This opens up the exciting and rapidly evolving field of molecular imaging, aiming at the non-invasive localisation of a biological process of interest in normal and diseased cells in animal models and humans in vivo. The main and most intriguing advantage of molecular imaging is the kinetic analysis of a given molecular event in the same experimental subject over time. This will allow non-invasive characterisation and ''phenotyping'' of animal models of human disease at various disease stages, under certain pathophysiological stimuli and after therapeutic intervention. The potential broad applications of imaging molecular events in vivo lie in the study of cell biology, biochemistry, gene/protein function and regulation, signal transduction, transcriptional regulation and characterisation of transgenic animals. Most importantly, molecular imaging will have great implications for the identification of potential molecular therapeutic targets, in the development of new treatment strategies, and in their successful implementation into clinical application. Here, the potential impact of molecular imaging by PET in applications in neuroscience research with a special focus on neurodegeneration and neuro-oncology is reviewed. (orig.)

  20. Choline Magnesium Trisalicylate

    Science.gov (United States)

    Choline magnesium trisalicylate is used to relieve the pain, tenderness, inflammation (swelling), and stiffness caused by arthritis and painful ... used to relieve pain and lower fever. Choline magnesium trisalicylate is in a class of nonsteroidal anti- ...

  1. Choline chloride based ionic liquid analogues as tool for the fabrication of agar films with improved mechanical properties

    Science.gov (United States)

    In the present paper, we test the suitability of Choline-Cl/urea (DES-U) and Choline-Cl/glycerol (DES-G) eutectic mixtures at 1:2 molar ratios for the production of agar biodegradable films. A three-step process is proposed: pre-solubilization of polymer in DES followed by compression-molding and s...

  2. Bias atlases for segmentation-based PET attenuation correction using PET-CT and MR.

    Science.gov (United States)

    Ouyang, Jinsong; Chun, Se Young; Petibon, Yoann; Bonab, Ali A; Alpert, Nathaniel; Fakhri, Georges El

    2013-10-01

    This study was to obtain voxel-wise PET accuracy and precision using tissue-segmentation for attenuation correction. We applied multiple thresholds to the CTs of 23 patients to classify tissues. For six of the 23 patients, MR images were also acquired. The MR fat/in-phase ratio images were used for fat segmentation. Segmented tissue classes were used to create attenuation maps, which were used for attenuation correction in PET reconstruction. PET bias images were then computed using the PET reconstructed with the original CT as the reference. We registered the CTs for all the patients and transformed the corresponding bias images accordingly. We then obtained the mean and standard deviation bias atlas using all the registered bias images. Our CT-based study shows that four-class segmentation (air, lungs, fat, other tissues), which is available on most PET-MR scanners, yields 15.1%, 4.1%, 6.6%, and 12.9% RMSE bias in lungs, fat, non-fat soft-tissues, and bones, respectively. An accurate fat identification is achievable using fat/in-phase MR images. Furthermore, we have found that three-class segmentation (air, lungs, other tissues) yields less than 5% standard deviation of bias within the heart, liver, and kidneys. This implies that three-class segmentation can be sufficient to achieve small variation of bias for imaging these three organs. Finally, we have found that inter- and intra-patient lung density variations contribute almost equally to the overall standard deviation of bias within the lungs.

  3. Wavelet-based partial volume effect correction for simultaneous MR/PET of the carotid arteries

    Energy Technology Data Exchange (ETDEWEB)

    Bini, Jason; Eldib, Mootaz [Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, NY, NY (United States); Department of Biomedical Engineering, The City College of New York, NY, NY (United States); Robson, Philip M; Fayad, Zahi A [Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, NY, NY (United States)

    2014-07-29

    Simultaneous MR/PET scanners allow for the exploration and development of novel PVE correction techniques without the challenges of coregistration of MR and PET. The development of a wavelet-based PVE correction method, to improve PET quantification, has proven successful in brain PET.{sup 2} We report here the first attempt to apply these methods to simultaneous MR/PET imaging of the carotid arteries.

  4. Wavelet-based partial volume effect correction for simultaneous MR/PET of the carotid arteries

    International Nuclear Information System (INIS)

    Bini, Jason; Eldib, Mootaz; Robson, Philip M; Fayad, Zahi A

    2014-01-01

    Simultaneous MR/PET scanners allow for the exploration and development of novel PVE correction techniques without the challenges of coregistration of MR and PET. The development of a wavelet-based PVE correction method, to improve PET quantification, has proven successful in brain PET. 2 We report here the first attempt to apply these methods to simultaneous MR/PET imaging of the carotid arteries.

  5. Software-based PET-MR image coregistration: combined PET-MRI for the rest of us

    International Nuclear Information System (INIS)

    Robertson, Matthew S.; Liu, Xinyang; Vyas, Pranav K.; Safdar, Nabile M.; Plishker, William; Zaki, George F.; Shekhar, Raj

    2016-01-01

    With the introduction of hybrid positron emission tomography/magnetic resonance imaging (PET/MRI), a new imaging option to acquire multimodality images with complementary anatomical and functional information has become available. Compared with hybrid PET/computed tomography (CT), hybrid PET/MRI is capable of providing superior anatomical detail while removing the radiation exposure associated with CT. The early adoption of hybrid PET/MRI, however, has been limited. To provide a viable alternative to the hybrid PET/MRI hardware by validating a software-based solution for PET-MR image coregistration. A fully automated, graphics processing unit-accelerated 3-D deformable image registration technique was used to align PET (acquired as PET/CT) and MR image pairs of 17 patients (age range: 10 months-21 years, mean: 10 years) who underwent PET/CT and body MRI (chest, abdomen or pelvis), which were performed within a 28-day (mean: 10.5 days) interval. MRI data for most of these cases included single-station post-contrast axial T1-weighted images. Following registration, maximum standardized uptake value (SUV max ) values observed in coregistered PET (cPET) and the original PET were compared for 82 volumes of interest. In addition, we calculated the target registration error as a measure of the quality of image coregistration, and evaluated the algorithm's performance in the context of interexpert variability. The coregistration execution time averaged 97±45 s. The overall relative SUV max difference was 7% between cPET-MRI and PET/CT. The average target registration error was 10.7±6.6 mm, which compared favorably with the typical voxel size (diagonal distance) of 8.0 mm (typical resolution: 0.66 mm x 0.66 mm x 8 mm) for MRI and 6.1 mm (typical resolution: 3.65 mm x 3.65 mm x 3.27 mm) for PET. The variability in landmark identification did not show statistically significant differences between the algorithm and a typical expert. We have presented a software-based

  6. Software-based PET-MR image coregistration: combined PET-MRI for the rest of us

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Matthew S.; Liu, Xinyang; Vyas, Pranav K.; Safdar, Nabile M. [Children' s National Health System, Sheikh Zayed Institute for Pediatric Surgical Innovation, Washington, DC (United States); Plishker, William; Zaki, George F. [IGI Technologies, Inc., College Park, MD (United States); Shekhar, Raj [Children' s National Health System, Sheikh Zayed Institute for Pediatric Surgical Innovation, Washington, DC (United States); IGI Technologies, Inc., College Park, MD (United States)

    2016-10-15

    With the introduction of hybrid positron emission tomography/magnetic resonance imaging (PET/MRI), a new imaging option to acquire multimodality images with complementary anatomical and functional information has become available. Compared with hybrid PET/computed tomography (CT), hybrid PET/MRI is capable of providing superior anatomical detail while removing the radiation exposure associated with CT. The early adoption of hybrid PET/MRI, however, has been limited. To provide a viable alternative to the hybrid PET/MRI hardware by validating a software-based solution for PET-MR image coregistration. A fully automated, graphics processing unit-accelerated 3-D deformable image registration technique was used to align PET (acquired as PET/CT) and MR image pairs of 17 patients (age range: 10 months-21 years, mean: 10 years) who underwent PET/CT and body MRI (chest, abdomen or pelvis), which were performed within a 28-day (mean: 10.5 days) interval. MRI data for most of these cases included single-station post-contrast axial T1-weighted images. Following registration, maximum standardized uptake value (SUV{sub max}) values observed in coregistered PET (cPET) and the original PET were compared for 82 volumes of interest. In addition, we calculated the target registration error as a measure of the quality of image coregistration, and evaluated the algorithm's performance in the context of interexpert variability. The coregistration execution time averaged 97±45 s. The overall relative SUV{sub max} difference was 7% between cPET-MRI and PET/CT. The average target registration error was 10.7±6.6 mm, which compared favorably with the typical voxel size (diagonal distance) of 8.0 mm (typical resolution: 0.66 mm x 0.66 mm x 8 mm) for MRI and 6.1 mm (typical resolution: 3.65 mm x 3.65 mm x 3.27 mm) for PET. The variability in landmark identification did not show statistically significant differences between the algorithm and a typical expert. We have presented a software-based

  7. An Evaluation of PET Based on Longitudinal Data.

    Science.gov (United States)

    Mandeville, Garrett K.

    Although teacher inservice programs based on Madeline Hunter's Program for Effective Teaching (PET) have become very popular in U.S. schools, there is little evidence that the Hunter model ultimately results in increased student achievement. This longitudinal study attempts to evaluate the effects of Hunter-based staff development programs on…

  8. Optimization for PET imaging based on phantom study and NECdensity

    International Nuclear Information System (INIS)

    Daisaki, Hiromitsu; Shimada, Naoki; Shinohara, Hiroyuki

    2012-01-01

    In consideration of the requirement for global standardization and quality control of PET imaging, the present studies gave an outline of phantom study to decide both scan and reconstruction parameters based on FDG-PET/CT procedure guideline in Japan, and optimization of scan duration based on NEC density was performed continuously. In the phantom study, scan and reconstruction parameters were decided by visual assessment and physical indexes (N 10mm , NEC phantom , Q H,10mm /N 10mm ) to visualize hot spot of 10 mm diameter with standardized uptake value (SUV)=4 explicitly. Simultaneously, Recovery Coefficient (RC) was evaluated to recognize that PET images had enough quantifiably. Scan durations were optimized by Body Mass Index (BMI) based on retrospective analysis of NEC density . Correlation between visual score in clinical FDG-PET images and NEC density fell after the optimization of scan duration. Both Inter-institution and inter-patient variability were decreased by performing the phantom study based on the procedure guideline and the optimization of scan duration based on NEC density which seem finally useful to practice highly precise examination and promote high-quality controlled study. (author)

  9. Temperature dependence of APD-based PET scanners

    International Nuclear Information System (INIS)

    Keereman, Vincent; Van Holen, Roel; Vandenberghe, Stefaan; Vanhove, Christian

    2013-01-01

    Purpose: Solid state detectors such as avalanche photodiodes (APDs) are increasingly being used in PET detectors. One of the disadvantages of APDs is the strong decrease of their gain factor with increasing ambient temperature. The light yield of most scintillation crystals also decreases when ambient temperature is increased. Both effects lead to considerable temperature dependence of the performance of APD-based PET scanners. In this paper, the authors propose a model for this dependence and the performance of the LabPET8 APD-based small animal PET scanner is evaluated at different temperatures.Methods: The model proposes that the effect of increasing temperature on the energy histogram of an APD-based PET scanner is a compression of the histogram along the energy axis. The energy histogram of the LabPET system was acquired at 21 °C and 25 °C to verify the validity of this model. Using the proposed model, the effect of temperature on system sensitivity was simulated for different detector temperature coefficients and temperatures. Subsequently, the effect of short term and long term temperature changes on the peak sensitivity of the LabPET system was measured. The axial sensitivity profile was measured at 21 °C and 24 °C following the NEMA NU 4-2008 standard. System spatial resolution was also evaluated. Furthermore, scatter fraction, count losses and random coincidences were evaluated at different temperatures. Image quality was also investigated.Results: As predicted by the model, the photopeak energy at 25 °C is lower than at 21 °C with a shift of approximately 6% per °C. Simulations showed that this results in an approximately linear decrease of sensitivity when temperature is increased from 21 °C to 24 °C and energy thresholds are constant. Experimental evaluation of the peak sensitivity at different temperatures showed a strong linear correlation for short term (2.32 kcps/MBq/°C = 12%/°C, R = −0.95) and long term (1.92 kcps/MBq/°C = 10%/

  10. Dietary Reference Values for choline

    DEFF Research Database (Denmark)

    Sjödin, Anders Mikael

    2016-01-01

    Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives Dietary Reference Values (DRVs) for choline. In this Opinion, the Panel considers dietary choline including choline compounds (e.g. glycerophosphocholine, phosphocholine...

  11. Basic study of entire whole-body PET scanners based on the OpenPET geometry

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Eiji, E-mail: rush@nirs.go.j [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan); Yamaya, Taiga; Nishikido, Fumihiko; Inadama, Naoko; Murayama, Hideo [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan)

    2010-09-21

    A conventional PET scanner has a 15-25 cm axial field-of-view (FOV) and images a whole body using about six bed positions. An OpenPET geometry can extend the axial FOV with a limited number of detectors. The entire whole-body PET scanner must be able to process a large amount of data effectively. In this work, we study feasibility of the fully 3D entire whole-body PET scanner using the GATE simulation. The OpenPET has 12 block detector rings with the ring diameter of 840 mm and each block detector ring consists of 48 depth-of-interaction (DOI) detectors. The OpenPET has the axial length of 895.95 mm with five parts of 58.95 mm open gaps. The OpenPET has higher single data loss than a conventional PET scanner at grouping circuits. NECR of the OpenPET decreases by single data loss. But single data loss is mitigated by separating the axially arranged detector into two parts. Also, multiple coincidences are found to be important for the entire whole-body PET scanner. The entire whole-body PET scanner with the OpenPET geometry promises to provide a large axial FOV with the open space and to have sufficient performance values. But single data loss at the grouping circuits and multiple coincidences are limited to the peak noise equivalent count rate (NECR) for the entire whole-body PET scanner.

  12. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanhua; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-02

    Highlights: • A strategy for extraction of protein based on DES-coated magnetic graphene oxide. • The deep eutectic solvents were based on choline chloride. • Bovine serum albumin was used as the analyte. • The material prepared works for the acidic but not the basic or the neutral proteins. - Abstract: Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe{sub 3}O{sub 4}@GO) to form Fe{sub 3}O{sub 4}@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe{sub 3}O{sub 4}@GO-DES, and the results indicated the successful preparation of Fe{sub 3}O{sub 4}@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe{sub 3}O{sub 4}@GO-DES. Comparison of Fe{sub 3}O{sub 4}@GO and Fe{sub 3}O{sub 4}@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe{sub 3}O{sub 4}@GO-DES performs better than Fe{sub 3}O{sub 4}@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L{sup −1} Na{sub 2}HPO{sub 4} contained 1 mol L{sup −1} NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled.

  13. Artificial Neural Network-Based System for PET Volume Segmentation

    Directory of Open Access Journals (Sweden)

    Mhd Saeed Sharif

    2010-01-01

    Full Text Available Tumour detection, classification, and quantification in positron emission tomography (PET imaging at early stage of disease are important issues for clinical diagnosis, assessment of response to treatment, and radiotherapy planning. Many techniques have been proposed for segmenting medical imaging data; however, some of the approaches have poor performance, large inaccuracy, and require substantial computation time for analysing large medical volumes. Artificial intelligence (AI approaches can provide improved accuracy and save decent amount of time. Artificial neural networks (ANNs, as one of the best AI techniques, have the capability to classify and quantify precisely lesions and model the clinical evaluation for a specific problem. This paper presents a novel application of ANNs in the wavelet domain for PET volume segmentation. ANN performance evaluation using different training algorithms in both spatial and wavelet domains with a different number of neurons in the hidden layer is also presented. The best number of neurons in the hidden layer is determined according to the experimental results, which is also stated Levenberg-Marquardt backpropagation training algorithm as the best training approach for the proposed application. The proposed intelligent system results are compared with those obtained using conventional techniques including thresholding and clustering based approaches. Experimental and Monte Carlo simulated PET phantom data sets and clinical PET volumes of nonsmall cell lung cancer patients were utilised to validate the proposed algorithm which has demonstrated promising results.

  14. Reproducibility of MR-based Attenuation Maps in PET/MRI and the Impact on PET Quantification in Lung Cancer

    DEFF Research Database (Denmark)

    Olin, Anders; Ladefoged, Claes N; Langer, Natasha H

    2018-01-01

    AIM: Quantitative positron emission tomography/magnetic resonance imaging (PET/MRI) is dependent upon reliable and reproducible MR-based attenuation correction (MR-AC). In this study we evaluated the quality of current vendor-provided thoracic MR-AC maps, and further investigated...... affecting the reproducibility of PET/MRI. This, in combination with other well-known sources of error associated with PET/MRI examinations, leads to inconsistent SUV measurements in serial studies and follow-up scenarios, which may affect the reliability of therapy response assessment. A thorough visual...

  15. Quantitative Evaluation of Atlas-based Attenuation Correction for Brain PET in an Integrated Time-of-Flight PET/MR Imaging System.

    Science.gov (United States)

    Yang, Jaewon; Jian, Yiqiang; Jenkins, Nathaniel; Behr, Spencer C; Hope, Thomas A; Larson, Peder E Z; Vigneron, Daniel; Seo, Youngho

    2017-07-01

    Purpose To assess the patient-dependent accuracy of atlas-based attenuation correction (ATAC) for brain positron emission tomography (PET) in an integrated time-of-flight (TOF) PET/magnetic resonance (MR) imaging system. Materials and Methods Thirty recruited patients provided informed consent in this institutional review board-approved study. All patients underwent whole-body fluorodeoxyglucose PET/computed tomography (CT) followed by TOF PET/MR imaging. With use of TOF PET data, PET images were reconstructed with four different attenuation correction (AC) methods: PET with patient CT-based AC (CTAC), PET with ATAC (air and bone from an atlas), PET with ATAC patientBone (air and tissue from the atlas with patient bone), and PET with ATAC boneless (air and tissue from the atlas without bone). For quantitative evaluation, PET mean activity concentration values were measured in 14 1-mL volumes of interest (VOIs) distributed throughout the brain and statistical significance was tested with a paired t test. Results The mean overall difference (±standard deviation) of PET with ATAC compared with PET with CTAC was -0.69 kBq/mL ± 0.60 (-4.0% ± 3.2) (P PET with ATAC boneless (-9.4% ± 3.7) was significantly worse than that of PET with ATAC (-4.0% ± 3.2) (P PET with ATAC patientBone (-1.5% ± 1.5) improved over that of PET with ATAC (-4.0% ± 3.2) (P PET/MR imaging achieves similar quantification accuracy to that from CTAC by means of atlas-based bone compensation. However, patient-specific anatomic differences from the atlas causes bone attenuation differences and misclassified sinuses, which result in patient-dependent performance variation of ATAC. © RSNA, 2017 Online supplemental material is available for this article.

  16. Bienzymatic Acetylcholinesterase and Choline Oxidase Immobilized Biosensor Based on a Phenyl Carboxylic Acid-Grafted Multiwalled Carbon Nanotube

    Directory of Open Access Journals (Sweden)

    So-Ra Lee

    2014-01-01

    Full Text Available Bienzymatic acetylcholinesterase (AChE and choline oxidase (ChOx immobilized biosensor based on a phenyl carboxylic acid-grafted multiwalled carbon nanotube (MWNT modified glass carbon electrode (GCE and carbon-screen printed electrode (SPE was fabricated for acetylcholine detection in human blood samples. Phenyl carboxylic acid-modified MWNT supports were prepared by electrochemical polymerization of 4-carboxyphenyl diazonium salts, which were synthesized by an amine group and sodium nitrite, on the surface of the MWNT-modified GCE and SPE in 0.1 M PBS. The successful fabrication of the AChE-ChOx-immobilized biosensor was confirmed via scanning electron microscopy (SEM, X-ray photoelectron spectroscopy (XPS, electrochemical impedance spectroscopy (EIS, and cyclic voltammetry (CV. The sensing range of the biosensor based on a GCE and SPE was 1.0~10 μM and 10~100 μM, respectively. The interfering effect of 0.1 M L-ascorbic acid, 0.1 M L-cysteine, and 0.1 M uric acid to 0.1 M acetylcholine was 3.00%, 9.00%, and 3.00%, respectively. Acetylcholine in a human blood sample was detected by the AChE-ChOx-immobilized biosensor.

  17. Towards Implementing an MR-based PET Attenuation Correction Method for Neurological Studies on the MR-PET Brain Prototype

    Science.gov (United States)

    Catana, Ciprian; van der Kouwe, Andre; Benner, Thomas; Michel, Christian J.; Hamm, Michael; Fenchel, Matthias; Fischl, Bruce; Rosen, Bruce; Schmand, Matthias; Sorensen, A. Gregory

    2013-01-01

    A number of factors have to be considered for implementing an accurate attenuation correction (AC) in a combined MR-PET scanner. In this work, some of these challenges were investigated and an AC method based entirely on the MR data obtained with a single dedicated sequence was developed and used for neurological studies performed with the MR-PET human brain scanner prototype. Methods The focus was on the bone/air segmentation problem, the bone linear attenuation coefficient selection and the RF coil positioning. The impact of these factors on the PET data quantification was studied in simulations and experimental measurements performed on the combined MR-PET scanner. A novel dual-echo ultra-short echo time (DUTE) MR sequence was proposed for head imaging. Simultaneous MR-PET data were acquired and the PET images reconstructed using the proposed MR-DUTE-based AC method were compared with the PET images reconstructed using a CT-based AC. Results Our data suggest that incorrectly accounting for the bone tissue attenuation can lead to large underestimations (>20%) of the radiotracer concentration in the cortex. Assigning a linear attenuation coefficient of 0.143 or 0.151 cm−1 to bone tissue appears to give the best trade-off between bias and variability in the resulting images. Not identifying the internal air cavities introduces large overestimations (>20%) in adjacent structures. Based on these results, the segmented CT AC method was established as the “silver standard” for the segmented MR-based AC method. Particular to an integrated MR-PET scanner, ignoring the RF coil attenuation can cause large underestimations (i.e. up to 50%) in the reconstructed images. Furthermore, the coil location in the PET field of view has to be accurately known. Good quality bone/air segmentation can be performed using the DUTE data. The PET images obtained using the MR-DUTE- and CT-based AC methods compare favorably in most of the brain structures. Conclusion An MR-DUTE-based AC

  18. Image artifacts from MR-based attenuation correction in clinical, whole-body PET/MRI

    DEFF Research Database (Denmark)

    Keller, Sune H; Holm, Søren; Hansen, Adam E

    2013-01-01

    Integrated whole-body PET/MRI tomographs have become available. PET/MR imaging has the potential to supplement, or even replace combined PET/CT imaging in selected clinical indications. However, this is true only if methodological pitfalls and image artifacts arising from novel MR-based attenuation...

  19. [Microeconomics of introduction of a PET system based on the revised Japanese National Insurance reimbursement system].

    Science.gov (United States)

    Abe, Katsumi; Kosuda, Shigeru; Kusano, Shoichi; Nagata, Masayoshi

    2003-11-01

    It is crucial to evaluate an annual balance before-hand when an institution installs a PET system because the revised Japanese national insurance reimbursement system set the cost of a FDG PET study as 75,000 yen. A break-even point was calculated in an 8-hour or a 24-hour operation of a PET system, based on the total costs reported. The break-even points were as follows: 13.4, 17.7, 22.1 studies per day for the 1 cyclotron-1 PET camera, 1 cyclotron-2 PET cameras, 1 cyclotron-3 PET cameras system, respectively, in an ordinary PET system operation of 8 hours. The break-even points were 19.9, 25.5, 31.2 studies per day for the 1 cyclotron-1 PET camera, 1 cyclotron-2 PET cameras, 1 cyclotron-3 PET cameras system, respectively, in a full PET system operation of 24 hours. The results indicate no profit would accrue in an ordinary PET system operation of 8 hours. The annual profit and break-even point for the total cost including the initial investment would be respectively 530 million yen and 2.8 years in a 24-hour operation with 1 cyclotron-3 PET cameras system.

  20. Microeconomics of introduction of a PET system based on the revised Japanese national insurance reimbursement system

    International Nuclear Information System (INIS)

    Abe, Katsumi; Kosuda, Shigeru; Kusano, Shoichi; Nagata, Masayoshi

    2003-01-01

    It is crucial to evaluate an annual balance beforehand when an institution installs a PET system because the revised Japanese national insurance reimbursement system set the cost of a FDG PET study as 75,000 yen. A break-even point was calculated in an 8-hour or a 24-hour operation of a PET system, based on the total costs reported. The break-even points were as follows: 13.4, 17.7, 22.1 studies per day for the 1 cyclotron-1 PET camera, 1 cyclotron-2 PET cameras, 1 cyclotron-3 PET cameras system, respectively, in an ordinary PET system operation of 8 hours. The break-even points were 19.9, 25.5, 31.2 studies per day for the 1 cyclotron-1 PET camera, 1 cyclotron-2 PET cameras, 1 cyclotron-3 PET cameras system, respectively, in a full PET system operation of 24 hours. The results indicate no profit would accrue in an ordinary PET system operation of 8 hours. The annual profit and break-even point for the total cost including the initial investment would be respectively 530 million yen and 2.8 years in a 24-hour operation with 1 cyclotron-3 PET cameras system. (author)

  1. A small animal PET prototype based on Silicon Photomultipliers

    International Nuclear Information System (INIS)

    Marcatili, S; Belcari, N.; Bisogni, M.G.; Del Guerra, A.; Collazuol, G.; Pedreschi, E.; Spinella, F.; Sportelli, G.; Marzocca, C.

    2011-01-01

    Next generation PET scanners should full fill very high requirements in terms of spatial, energy and timing resolution. Modern scanner performances are inherently limited by the use of standard photomultiplier tubes. The use of Silicon Photomultiplier (Si P M) matrices is proposed for the construction of a small animal PET system consisting of two detector heads based on Lyso continuos crystals. The use of large area multi-pixel Silicon Photomultiplier (Si P M) detectors requires the development of a multichannel Digital Acquisition system (DAQ) as well as of a dedicated front-end in order not to degrade the intrinsic detector capabilities. At the University of Pisa and INFN Pisa we developed a DAQ board for the read-out of 2 64-pixel Si P M matrices in time coincidence for Positron Emission Tomography (PET) applications. The proof of principles is based on 64-pixel detectors, but the whole system has been conceived to be easily scalable to a higher number of channels. Here we describe the Group-V INFN DASi P M 2 (Development and Application of Si P M) project and related results.

  2. Congruency of tumour volume delineated by FET PET and MRSI

    Energy Technology Data Exchange (ETDEWEB)

    Mauler, Jörg; Langen, Karl-Josef [Institute of Neuroscience and Medicine, Forschungszentrum Jülich (Germany); Maudsley, Andrew A [Miller School of Medicine, University of Miami (United States); Nikoubashman, Omid [Department of Neuroradiology, Faculty of Medicine, RWTH Aachen University (Germany); Filss, Christian; Stoffels, Gabriele; Shah, N Jon [Institute of Neuroscience and Medicine, Forschungszentrum Jülich (Germany)

    2015-05-18

    In addition to MR imaging, PET imaging of O-(2-[18F]Fluorethyl)-L-Tyrosine (FET) uptake provides information on brain tumour extent and metabolic activity. Similarly, MRS has been shown to be of value for distinguishing high- from low-grade gliomas. Based on 2D spatially resolved MRSI, an overlap between 18FET uptake and the choline/N-acetyl-aspartate (Cho/NAA) ratio of more than 75 % has been reported.

  3. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein.

    Science.gov (United States)

    Huang, Yanhua; Wang, Yuzhi; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-02

    Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe3O4@GO) to form Fe3O4@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe3O4@GO-DES, and the results indicated the successful preparation of Fe3O4@GO-DES. The UV-vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe3O4@GO-DES. Comparison of Fe3O4@GO and Fe3O4@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe3O4@GO-DES performs better than Fe3O4@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L(-1) Na2HPO4 contained 1 mol L(-1) NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Molar enthalpy of mixing and refractive indices of choline chloride-based deep eutectic solvents with water

    International Nuclear Information System (INIS)

    Ma, Chunyan; Guo, Yanhua; Li, Dongxue; Zong, Jianpeng; Ji, Xiaoyan; Liu, Chang

    2017-01-01

    Highlights: • Molar enthalpy of mixing and refractive indices for binary mixtures of different deep eutectic solvents with water. • The Redlich–Kister equation and the NRTL model was used to fit the experimental data. • The NRTL model with fitted parameters were used to predict the vapour pressure and compared with experimental data. - Abstract: The molar enthalpies of mixing were measured for binary systems of choline chloride-based deep eutectic solvents (glycerol, ethylene glycol and malonic acid) with water at 298.15 K and 308.15 K, and atmospheric pressure with an isothermal calorimeter. Refractive indices were also measured at 303.15 K and atmospheric pressure. The binary mixtures of {chcl/glycerol (1:2) + water, chcl/ethylene glycol (1:2) + water} showed exothermic behaviour over the entire range of composition, while the binary mixture of {chcl/malonic acid (1:1) + water} showed endothermic behaviour at first and then changed to be exothermic with the increasing content of chcl/malonic acid (1:1). Experimental refractive indices were fitted with the Redlich–Kister equation, and experimental molar enthalpies of mixing were correlated with the Redlich–Kister equation and the non-random two-liquid (NRTL) model. The NRTL model with the fitted parameters was used to predict the vapour pressures of these three mixtures. For mixtures of {chcl/glycerol (1:2) + water} and {chcl/ethylene glycol (1:2) + water}, the predicted vapour pressures agreed well with the experimental results from the literature. While for mixture of {chcl/malonic acid (1:1) + water}, the predicted vapour pressures showed deviation at the high concentration of chcl/malonic acid (1:1), and this was probably because of the complex molecular interaction between chcl/malonic acid (1:1) and water.

  5. Towards quantitative PET/MRI: a review of MR-based attenuation correction techniques.

    Science.gov (United States)

    Hofmann, Matthias; Pichler, Bernd; Schölkopf, Bernhard; Beyer, Thomas

    2009-03-01

    Positron emission tomography (PET) is a fully quantitative technology for imaging metabolic pathways and dynamic processes in vivo. Attenuation correction of raw PET data is a prerequisite for quantification and is typically based on separate transmission measurements. In PET/CT attenuation correction, however, is performed routinely based on the available CT transmission data. Recently, combined PET/magnetic resonance (MR) has been proposed as a viable alternative to PET/CT. Current concepts of PET/MRI do not include CT-like transmission sources and, therefore, alternative methods of PET attenuation correction must be found. This article reviews existing approaches to MR-based attenuation correction (MR-AC). Most groups have proposed MR-AC algorithms for brain PET studies and more recently also for torso PET/MR imaging. Most MR-AC strategies require the use of complementary MR and transmission images, or morphology templates generated from transmission images. We review and discuss these algorithms and point out challenges for using MR-AC in clinical routine. MR-AC is work-in-progress with potentially promising results from a template-based approach applicable to both brain and torso imaging. While efforts are ongoing in making clinically viable MR-AC fully automatic, further studies are required to realize the potential benefits of MR-based motion compensation and partial volume correction of the PET data.

  6. Towards quantitative PET/MRI: a review of MR-based attenuation correction techniques

    International Nuclear Information System (INIS)

    Hofmann, Matthias; Pichler, Bernd; Schoelkopf, Bernhard; Beyer, Thomas

    2009-01-01

    Positron emission tomography (PET) is a fully quantitative technology for imaging metabolic pathways and dynamic processes in vivo. Attenuation correction of raw PET data is a prerequisite for quantification and is typically based on separate transmission measurements. In PET/CT attenuation correction, however, is performed routinely based on the available CT transmission data. Recently, combined PET/magnetic resonance (MR) has been proposed as a viable alternative to PET/CT. Current concepts of PET/MRI do not include CT-like transmission sources and, therefore, alternative methods of PET attenuation correction must be found. This article reviews existing approaches to MR-based attenuation correction (MR-AC). Most groups have proposed MR-AC algorithms for brain PET studies and more recently also for torso PET/MR imaging. Most MR-AC strategies require the use of complementary MR and transmission images, or morphology templates generated from transmission images. We review and discuss these algorithms and point out challenges for using MR-AC in clinical routine. MR-AC is work-in-progress with potentially promising results from a template-based approach applicable to both brain and torso imaging. While efforts are ongoing in making clinically viable MR-AC fully automatic, further studies are required to realize the potential benefits of MR-based motion compensation and partial volume correction of the PET data. (orig.)

  7. Towards quantitative PET/MRI: a review of MR-based attenuation correction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Matthias [Max Planck Institute for Biological Cybernetics, Tuebingen (Germany); University of Tuebingen, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Radiology, Tuebingen (Germany); University of Oxford, Wolfson Medical Vision Laboratory, Department of Engineering Science, Oxford (United Kingdom); Pichler, Bernd [University of Tuebingen, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Radiology, Tuebingen (Germany); Schoelkopf, Bernhard [Max Planck Institute for Biological Cybernetics, Tuebingen (Germany); Beyer, Thomas [University Hospital Duisburg-Essen, Department of Nuclear Medicine, Essen (Germany); Cmi-Experts GmbH, Zurich (Switzerland)

    2009-03-15

    Positron emission tomography (PET) is a fully quantitative technology for imaging metabolic pathways and dynamic processes in vivo. Attenuation correction of raw PET data is a prerequisite for quantification and is typically based on separate transmission measurements. In PET/CT attenuation correction, however, is performed routinely based on the available CT transmission data. Recently, combined PET/magnetic resonance (MR) has been proposed as a viable alternative to PET/CT. Current concepts of PET/MRI do not include CT-like transmission sources and, therefore, alternative methods of PET attenuation correction must be found. This article reviews existing approaches to MR-based attenuation correction (MR-AC). Most groups have proposed MR-AC algorithms for brain PET studies and more recently also for torso PET/MR imaging. Most MR-AC strategies require the use of complementary MR and transmission images, or morphology templates generated from transmission images. We review and discuss these algorithms and point out challenges for using MR-AC in clinical routine. MR-AC is work-in-progress with potentially promising results from a template-based approach applicable to both brain and torso imaging. While efforts are ongoing in making clinically viable MR-AC fully automatic, further studies are required to realize the potential benefits of MR-based motion compensation and partial volume correction of the PET data. (orig.)

  8. MR-based attenuation correction for cardiac FDG PET on a hybrid PET/MRI scanner: comparison with standard CT attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Vontobel, Jan; Liga, Riccardo; Possner, Mathias; Clerc, Olivier F.; Mikulicic, Fran; Veit-Haibach, Patrick; Voert, Edwin E.G.W. ter; Fuchs, Tobias A.; Stehli, Julia; Pazhenkottil, Aju P.; Benz, Dominik C.; Graeni, Christoph; Gaemperli, Oliver; Herzog, Bernhard; Buechel, Ronny R.; Kaufmann, Philipp A. [University Hospital Zurich, Department of Nuclear Medicine, Zurich (Switzerland)

    2015-09-15

    The aim of this study was to evaluate the feasibility of attenuation correction (AC) for cardiac {sup 18}F-labelled fluorodeoxyglucose (FDG) positron emission tomography (PET) using MR-based attenuation maps. We included 23 patients with no known cardiac history undergoing whole-body FDG PET/CT imaging for oncological indications on a PET/CT scanner using time-of-flight (TOF) and subsequent whole-body PET/MR imaging on an investigational hybrid PET/MRI scanner. Data sets from PET/MRI (with and without TOF) were reconstructed using MR AC and semi-quantitative segmental (20-segment model) myocardial tracer uptake (per cent of maximum) and compared to PET/CT which was reconstructed using CT AC and served as standard of reference. Excellent correlations were found for regional uptake values between PET/CT and PET/MRI with TOF (n = 460 segments in 23 patients; r = 0.913; p < 0.0001) with narrow Bland-Altman limits of agreement (-8.5 to +12.6 %). Correlation coefficients were slightly lower between PET/CT and PET/MRI without TOF (n = 460 segments in 23 patients; r = 0.851; p < 0.0001) with broader Bland-Altman limits of agreement (-12.5 to +15.0 %). PET/MRI with and without TOF showed minimal underestimation of tracer uptake (-2.08 and -1.29 %, respectively), compared to PET/CT. Relative myocardial FDG uptake obtained from MR-based attenuation corrected FDG PET is highly comparable to standard CT-based attenuation corrected FDG PET, suggesting interchangeability of both AC techniques. (orig.)

  9. Intensity Modulated Radiation Therapy Dose Painting for Localized Prostate Cancer Using 11C-choline Positron Emission Tomography Scans

    International Nuclear Information System (INIS)

    Chang, Joe H.; Lim Joon, Daryl; Lee, Sze Ting; Gong, Sylvia J.; Anderson, Nigel J.; Scott, Andrew M.; Davis, Ian D.; Clouston, David; Bolton, Damien; Hamilton, Christopher S.; Khoo, Vincent

    2012-01-01

    Purpose: To demonstrate the technical feasibility of intensity modulated radiation therapy (IMRT) dose painting using 11 C-choline positron emission tomography PET scans in patients with localized prostate cancer. Methods and Materials: This was an RT planning study of 8 patients with prostate cancer who had 11 C-choline PET scans prior to radical prostatectomy. Two contours were semiautomatically generated on the basis of the PET scans for each patient: 60% and 70% of the maximum standardized uptake values (SUV 60% and SUV 70% ). Three IMRT plans were generated for each patient: PLAN 78 , which consisted of whole-prostate radiation therapy to 78 Gy; PLAN 78-90 , which consisted of whole-prostate RT to 78 Gy, a boost to the SUV 60% to 84 Gy, and a further boost to the SUV 70% to 90 Gy; and PLAN 72-90 , which consisted of whole-prostate RT to 72 Gy, a boost to the SUV 60% to 84 Gy, and a further boost to the SUV 70% to 90 Gy. The feasibility of these plans was judged by their ability to reach prescription doses while adhering to published dose constraints. Tumor control probabilities based on PET scan-defined volumes (TCP PET ) and on prostatectomy-defined volumes (TCP path ), and rectal normal tissue complication probabilities (NTCP) were compared between the plans. Results: All plans for all patients reached prescription doses while adhering to dose constraints. TCP PET values for PLAN 78 , PLAN 78-90 , and PLAN 72-90 were 65%, 97%, and 96%, respectively. TCP path values were 71%, 97%, and 89%, respectively. Both PLAN 78-90 and PLAN 72-90 had significantly higher TCP PET (P=.002 and .001) and TCP path (P 78 . PLAN 78-90 and PLAN 72-90 were not significantly different in terms of TCP PET or TCP path . There were no significant differences in rectal NTCPs between the 3 plans. Conclusions: IMRT dose painting for localized prostate cancer using 11 C-choline PET scans is technically feasible. Dose painting results in higher TCPs without higher NTCPs.

  10. Model-based normalization for iterative 3D PET image

    International Nuclear Information System (INIS)

    Bai, B.; Li, Q.; Asma, E.; Leahy, R.M.; Holdsworth, C.H.; Chatziioannou, A.; Tai, Y.C.

    2002-01-01

    We describe a method for normalization in 3D PET for use with maximum a posteriori (MAP) or other iterative model-based image reconstruction methods. This approach is an extension of previous factored normalization methods in which we include separate factors for detector sensitivity, geometric response, block effects and deadtime. Since our MAP reconstruction approach already models some of the geometric factors in the forward projection, the normalization factors must be modified to account only for effects not already included in the model. We describe a maximum likelihood approach to joint estimation of the count-rate independent normalization factors, which we apply to data from a uniform cylindrical source. We then compute block-wise and block-profile deadtime correction factors using singles and coincidence data, respectively, from a multiframe cylindrical source. We have applied this method for reconstruction of data from the Concorde microPET P4 scanner. Quantitative evaluation of this method using well-counter measurements of activity in a multicompartment phantom compares favourably with normalization based directly on cylindrical source measurements. (author)

  11. GPU based Monte Carlo for PET image reconstruction: parameter optimization

    International Nuclear Information System (INIS)

    Cserkaszky, Á; Légrády, D.; Wirth, A.; Bükki, T.; Patay, G.

    2011-01-01

    This paper presents the optimization of a fully Monte Carlo (MC) based iterative image reconstruction of Positron Emission Tomography (PET) measurements. With our MC re- construction method all the physical effects in a PET system are taken into account thus superior image quality is achieved in exchange for increased computational effort. The method is feasible because we utilize the enormous processing power of Graphical Processing Units (GPUs) to solve the inherently parallel problem of photon transport. The MC approach regards the simulated positron decays as samples in mathematical sums required in the iterative reconstruction algorithm, so to complement the fast architecture, our work of optimization focuses on the number of simulated positron decays required to obtain sufficient image quality. We have achieved significant results in determining the optimal number of samples for arbitrary measurement data, this allows to achieve the best image quality with the least possible computational effort. Based on this research recommendations can be given for effective partitioning of computational effort into the iterations in limited time reconstructions. (author)

  12. Imaging and PET - PET/CT imaging

    International Nuclear Information System (INIS)

    Von Schulthess, G.K.; Hany, Th.F.

    2008-01-01

    PET/CT has grown because the lack of anatomic landmarks in PET makes 'hardware-fusion' to anatomic cross-sectional data extremely useful. Addition of CT to PET improves specificity, but also sensitivity, and adding PET to CT adds sensitivity and specificity in tumor imaging. The synergistic advantage of adding CT is that the attenuation correction needed for PET data can also be derived from the CT data. This makes PET-CT 25-30% faster than PET alone, leading to higher patient throughput and a more comfortable examination for patients typically lasting 20 minutes or less. FDG-PET-CT appears to provide relevant information in the staging and therapy monitoring of many tumors, such as lung carcinoma, colorectal cancer, lymphoma, gynaecological cancers, melanoma and many others, with the notable exception of prostatic cancer. for this cancer, choline derivatives may possibly become useful radiopharmaceuticals. The published literature on the applications of FDG-PET-CT in oncology is still limited but several designed studies have demonstrated the benefits of PET-CT. (authors)

  13. Implementation and application of simulation platform of PET based on GATE

    International Nuclear Information System (INIS)

    Zhang Bin; Zhao Shujun; Zhang Shixun; Liu Haojia

    2010-01-01

    Positron emission tomography (PET) is a tool for obtaining functional image in vivo and GATE is a dedicated software for PET/SPECT simulation based on Mentor Carlo Method. It encapsulates the Geant4 libraries to achieve a modular and provides a number of new characteristics. In practice, a simulation platform of PET has been builded employing GATE based on Ubuntu operating system, including many keys and skills in the process. We have exploited benchmark PET, a testing example in GATE, and implemented PET scanner simulation in the end. Through analyzing the simulation data, the result demonstrate that predictive goal has been reached. The work provides the foundation for investigating PET scanner and optimizing the algorithm of tomograph image reconstruction. (authors)

  14. Performance simulation of a MRPC-based PET imaging system

    Science.gov (United States)

    Roy, A.; Banerjee, A.; Biswas, S.; Chattopadhyay, S.; Das, G.; Saha, S.

    2014-10-01

    The less expensive and high resolution Multi-gap Resistive Plate Chamber (MRPC) opens up a new possibility to find an efficient alternative detector for the Time of Flight (TOF) based Positron Emission Tomography, where the sensitivity of the system depends largely on the time resolution of the detector. In a layered structure, suitable converters can be used to increase the photon detection efficiency. In this work, we perform a detailed GEANT4 simulation to optimize the converter thickness towards improving the efficiency of photon conversion. A Monte Carlo based procedure has been developed to simulate the time resolution of the MRPC-based system, making it possible to simulate its response for PET imaging application. The results of the test of a six-gap MRPC, operating in avalanche mode, with 22Na source have been discussed.

  15. Poster - 01: LabPET II Pixelated APD-Based PET Scanner for High-Resolution Preclinical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte, Roger; Arpin, Louis; Beaudoin, Jean-François; Bergeron, Mélanie; Bouchard, Jonathan; Bouziri, Haithem; Cadorette, Jules; Gaudin, Émilie; Jürgensen, Nadia; Koua, Konin Calliste; Trépanier, Pierre-Yves Lauzier; Leroux, Jean-Daniel; Loignon-Houle, Francis; Njejimana, Larissa; Paillé, Maxime; Paulin, Caroline; Pepin, Catherine; Pratte, Jean-François; Samson, Arnaud; Thibaudeau, Christian [Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, Université de Sherbrooke, Université de Sherbrooke, 3IT, Université de Sherbrooke, Novalgo Inc., Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, 3IT, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, 3IT, Université de Sherbrooke (Canada); and others

    2016-08-15

    Purpose: LabPET II is a new generation APD-based PET scanner designed to achieve sub-mm spatial resolution using truly pixelated detectors and highly integrated parallel front-end processing electronics. Methods: The basic element uses a 4×8 array of 1.12×1.12 mm{sup 2} Lu{sub 1.9}Y{sub 0.1}SiO{sub 5}:Ce (LYSO) scintillator pixels with one-to-one coupling to a 4×8 pixelated monolithic APD array mounted on a ceramic carrier. Four detector arrays are mounted on a daughter board carrying two flip-chip, 64-channel, mixed-signal, application-specific integrated circuits (ASIC) on the backside interfacing to two detector arrays each. Fully parallel signal processing was implemented in silico by encoding time and energy information using a dual-threshold Time-over-Threshold (ToT) scheme. The self-contained 128-channel detector module was designed as a generic component for ultra-high resolution PET imaging of small to medium-size animals. Results: Energy and timing performance were optimized by carefully setting ToT thresholds to minimize the noise/slope ratio. ToT spectra clearly show resolved 511 keV photopeak and Compton edge with ToT resolution well below 10%. After correction for nonlinear ToT response, energy resolution is typically 24±2% FWHM. Coincidence time resolution between opposing 128-channel modules is below 4 ns FWHM. Initial imaging results demonstrate that 0.8 mm hot spots of a Derenzo phantom can be resolved. Conclusion: A new generation PET scanner featuring truly pixelated detectors was developed and shown to achieve a spatial resolution approaching the physical limit of PET. Future plans are to integrate a small-bore dedicated mouse version of the scanner within a PET/CT platform.

  16. Health physics and quality control management of a cyclotron-based PET facility

    International Nuclear Information System (INIS)

    Jerabek, P.A.

    1995-01-01

    This paper provides an overview of the operation and management of a Positron Emission Tomography (PET) facility at the University of Texas. The facility components are discussed from an operations perspective with an emphasis on devices, and on practices and procedures which are implemented to ensure that personnel exposures are as low as reasonably achievable. The cyclotron-based PET facility uses in-house production of PET radioisotopes for preparation of radiopharmaceuticals. A combination of specially designed cyclotron equipped devices, radiopharmaceutical preparation devices, and shielded devices along with health physics practices have helped to make PET operations become routine

  17. Value of a dixon-based MR/PET attenuation correction sequence for the localization and evaluation of PET-positive lesions

    International Nuclear Information System (INIS)

    Eiber, Matthias; Holzapfel, Konstantin; Rummeny, Ernst J.; Martinez-Moeller, Axel; Souvatzoglou, Michael; Ziegler, Sibylle; Schwaiger, Markus; Nekolla, Stephan G.; Beer, Ambros J.; Pickhard, Anja; Loeffelbein, Dennys; Santi, Ivan

    2011-01-01

    In this study, the potential contribution of Dixon-based MR imaging with a rapid low-resolution breath-hold sequence, which is a technique used for MR-based attenuation correction (AC) for MR/positron emission tomography (PET), was evaluated for anatomical correlation of PET-positive lesions on a 3T clinical scanner compared to low-dose CT. This technique is also used in a recently installed fully integrated whole-body MR/PET system. Thirty-five patients routinely scheduled for oncological staging underwent 18 F-fluorodeoxyglucose (FDG) PET/CT and a 2-point Dixon 3-D volumetric interpolated breath-hold examination (VIBE) T1-weighted MR sequence on the same day. Two PET data sets reconstructed using attenuation maps from low-dose CT (PET AC C T ) or simulated MR-based segmentation (PET AC M R ) were evaluated for focal PET-positive lesions. The certainty for the correlation with anatomical structures was judged in the low-dose CT and Dixon-based MRI on a 4-point scale (0-3). In addition, the standardized uptake values (SUVs) for PET AC C T and PET AC M R were compared. Statistically, no significant difference could be found concerning anatomical localization for all 81 PET-positive lesions in low-dose CT compared to Dixon-based MR (mean 2.51 ± 0.85 and 2.37 ± 0.87, respectively; p = 0.1909). CT tended to be superior for small lymph nodes, bone metastases and pulmonary nodules, while Dixon-based MR proved advantageous for soft tissue pathologies like head/neck tumours and liver metastases. For the PET AC C T - and PET AC M R -based SUVs (mean 6.36 ± 4.47 and 6.31 ± 4.52, respectively) a nearly complete concordance with a highly significant correlation was found (r = 0.9975, p < 0.0001). Dixon-based MR imaging for MR AC allows for anatomical allocation of PET-positive lesions similar to low-dose CT in conventional PET/CT. Thus, this approach appears to be useful for future MR/PET for body regions not fully covered by diagnostic MRI due to potential time

  18. Development of a MPPC-based prototype gantry for future MRI-PET scanners

    Science.gov (United States)

    Kurei, Y.; Kataoka, J.; Kato, T.; Fujita, T.; Ohshima, T.; Taya, T.; Yamamoto, S.

    2014-12-01

    We have developed a high spatial resolution, compact Positron Emission Tomography (PET) module designed for small animals and intended for use in magnetic resonance imaging (MRI) systems. This module consists of large-area, 4 × 4 ch MPPC arrays (S11830-3344MF; Hamamatsu Photonics K.K.) optically coupled with Ce-doped (Lu,Y)2(SiO4)O (Ce:LYSO) scintillators fabricated into 16 × 16 matrices of 0.5 × 0.5 mm2 pixels. We set the temperature sensor (LM73CIMK-0; National Semiconductor Corp.) at the rear of the MPPC acceptance surface, and apply optimum voltage to maintain the gain. The eight MPPC-based PET modules and coincidence circuits were assembled into a gantry arranged in a ring 90 mm in diameter to form the MPPC-based PET system. We have developed two types PET gantry: one made of non-magnetic metal and the other made of acrylonitrile butadiene styrene (ABS) resins. The PET gantry was positioned around the RF coil of the 4.7 T MRI system. We took an image of a point }22Na source under fast spin echo (FSE) and gradient echo (GE), in order to measure the interference between the MPPC-based PET and MRI. The spatial resolution of PET imaging in a transaxial plane of about 1 mm (FWHM) was achieved in all cases. Operating with PET made of ABS has no effect on MR images, while operating with PET made of non-magnetic metal has a significant detrimental effect on MR images. This paper describes our quantitative evaluations of PET images and MR images, and presents a more advanced version of the gantry for future MRI/DOI-PET systems.

  19. PET based nanocomposite films for microwave packaging applications

    International Nuclear Information System (INIS)

    Galdi, M. R.; Olivieri, R.; Liguori, L.; Albanese, D.; Di Matteo, M.; Di Maio, L.

    2015-01-01

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET

  20. PET based nanocomposite films for microwave packaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Galdi, M. R., E-mail: mrgaldi@unisa.it; Olivieri, R.; Liguori, L.; Albanese, D., E-mail: dalbanese@unisa.it; Di Matteo, M.; Di Maio, L., E-mail: ldimaio@unisa.it [Industrial Engineering Department, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (Italy)

    2015-12-17

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET.

  1. PET based nanocomposite films for microwave packaging applications

    Science.gov (United States)

    Galdi, M. R.; Olivieri, R.; Liguori, L.; Albanese, D.; Di Matteo, M.; Di Maio, L.

    2015-12-01

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET.

  2. Imaging performance of LabPET APD-based digital PET scanners for pre-clinical research

    International Nuclear Information System (INIS)

    Bergeron, Mélanie; Cadorette, Jules; Beaudoin, Jean-François; Lecomte, Roger; Tétrault, Marc-André; Leroux, Jean-Daniel; Fontaine, Réjean

    2014-01-01

    The LabPET is an avalanche photodiode (APD) based digital PET scanner with quasi-individual detector read-out and highly parallel electronic architecture for high-performance in vivo molecular imaging of small animals. The scanner is based on LYSO and LGSO scintillation crystals (2×2×12/14 mm 3 ), assembled side-by-side in phoswich pairs read out by an APD. High spatial resolution is achieved through the individual and independent read-out of an individual APD detector for recording impinging annihilation photons. The LabPET exists in three versions, LabPET4 (3.75 cm axial length), LabPET8 (7.5 cm axial length) and LabPET12 (11.4 cm axial length). This paper focuses on the systematic characterization of the three LabPET versions using two different energy window settings to implement a high-efficiency mode (250–650 keV) and a high-resolution mode (350–650 keV) in the most suitable operating conditions. Prior to measurements, a global timing alignment of the scanners and optimization of the APD operating bias have been carried out. Characteristics such as spatial resolution, absolute sensitivity, count rate performance and image quality have been thoroughly investigated following the NEMA NU 4-2008 protocol. Phantom and small animal images were acquired to assess the scanners' suitability for the most demanding imaging tasks in preclinical biomedical research. The three systems achieve the same radial FBP spatial resolution at 5 mm from the field-of-view center: 1.65/3.40 mm (FWHM/FWTM) for an energy threshold of 250 keV and 1.51/2.97 mm for an energy threshold of 350 keV. The absolute sensitivity for an energy window of 250–650 keV is 1.4%/2.6%/4.3% for LabPET4/8/12, respectively. The best count rate performance peaking at 362 kcps is achieved by the LabPET12 with an energy window of 250–650 keV and a mouse phantom (2.5 cm diameter) at an activity of 2.4 MBq ml −1 . With the same phantom, the scatter fraction for all scanners is about

  3. Contourlet-based active contour model for PET image segmentation

    NARCIS (Netherlands)

    Abdoli, M.; Dierckx, R. A. J. O.; Zaidi, H.

    Purpose: PET-guided radiation therapy treatment planning, clinical diagnosis, assessment of tumor growth, and therapy response rely on the accurate delineation of the tumor volume and quantification of tracer uptake. Most PET image segmentation techniques proposed thus far are suboptimal in the

  4. Predicting standard-dose PET image from low-dose PET and multimodal MR images using mapping-based sparse representation

    International Nuclear Information System (INIS)

    Wang, Yan; Zhou, Jiliu; Zhang, Pei; An, Le; Ma, Guangkai; Kang, Jiayin; Shi, Feng; Shen, Dinggang; Wu, Xi; Lalush, David S; Lin, Weili

    2016-01-01

    Positron emission tomography (PET) has been widely used in clinical diagnosis for diseases and disorders. To obtain high-quality PET images requires a standard-dose radionuclide (tracer) injection into the human body, which inevitably increases risk of radiation exposure. One possible solution to this problem is to predict the standard-dose PET image from its low-dose counterpart and its corresponding multimodal magnetic resonance (MR) images. Inspired by the success of patch-based sparse representation (SR) in super-resolution image reconstruction, we propose a mapping-based SR (m-SR) framework for standard-dose PET image prediction. Compared with the conventional patch-based SR, our method uses a mapping strategy to ensure that the sparse coefficients, estimated from the multimodal MR images and low-dose PET image, can be applied directly to the prediction of standard-dose PET image. As the mapping between multimodal MR images (or low-dose PET image) and standard-dose PET images can be particularly complex, one step of mapping is often insufficient. To this end, an incremental refinement framework is therefore proposed. Specifically, the predicted standard-dose PET image is further mapped to the target standard-dose PET image, and then the SR is performed again to predict a new standard-dose PET image. This procedure can be repeated for prediction refinement of the iterations. Also, a patch selection based dictionary construction method is further used to speed up the prediction process. The proposed method is validated on a human brain dataset. The experimental results show that our method can outperform benchmark methods in both qualitative and quantitative measures. (paper)

  5. Current concepts in F18 FDG PET/CT-based Radiation Therapy planning for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Percy eLee

    2012-07-01

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

  6. Direct Reconstruction of CT-based Attenuation Correction Images for PET with Cluster-Based Penalties

    Science.gov (United States)

    Kim, Soo Mee; Alessio, Adam M.; De Man, Bruno; Asma, Evren; Kinahan, Paul E.

    2015-01-01

    Extremely low-dose CT acquisitions for the purpose of PET attenuation correction will have a high level of noise and biasing artifacts due to factors such as photon starvation. This work explores a priori knowledge appropriate for CT iterative image reconstruction for PET attenuation correction. We investigate the maximum a posteriori (MAP) framework with cluster-based, multinomial priors for the direct reconstruction of the PET attenuation map. The objective function for direct iterative attenuation map reconstruction was modeled as a Poisson log-likelihood with prior terms consisting of quadratic (Q) and mixture (M) distributions. The attenuation map is assumed to have values in 4 clusters: air+background, lung, soft tissue, and bone. Under this assumption, the MP was a mixture probability density function consisting of one exponential and three Gaussian distributions. The relative proportion of each cluster was jointly estimated during each voxel update of direct iterative coordinate decent (dICD) method. Noise-free data were generated from NCAT phantom and Poisson noise was added. Reconstruction with FBP (ramp filter) was performed on the noise-free (ground truth) and noisy data. For the noisy data, dICD reconstruction was performed with the combination of different prior strength parameters (β and γ) of Q- and M-penalties. The combined quadratic and mixture penalties reduces the RMSE by 18.7% compared to post-smoothed iterative reconstruction and only 0.7% compared to quadratic alone. For direct PET attenuation map reconstruction from ultra-low dose CT acquisitions, the combination of quadratic and mixture priors offers regularization of both variance and bias and is a potential method to derive attenuation maps with negligible patient dose. However, the small improvement in quantitative accuracy relative to the substantial increase in algorithm complexity does not currently justify the use of mixture-based PET attenuation priors for reconstruction of CT

  7. Wobbling and LSF-based maximum likelihood expectation maximization reconstruction for wobbling PET

    International Nuclear Information System (INIS)

    Kim, Hang-Keun; Son, Young-Don; Kwon, Dae-Hyuk; Joo, Yohan; Cho, Zang-Hee

    2016-01-01

    Positron emission tomography (PET) is a widely used imaging modality; however, the PET spatial resolution is not yet satisfactory for precise anatomical localization of molecular activities. Detector size is the most important factor because it determines the intrinsic resolution, which is approximately half of the detector size and determines the ultimate PET resolution. Detector size, however, cannot be made too small because both the decreased detection efficiency and the increased septal penetration effect degrade the image quality. A wobbling and line spread function (LSF)-based maximum likelihood expectation maximization (WL-MLEM) algorithm, which combined the MLEM iterative reconstruction algorithm with wobbled sampling and LSF-based deconvolution using the system matrix, was proposed for improving the spatial resolution of PET without reducing the scintillator or detector size. The new algorithm was evaluated using a simulation, and its performance was compared with that of the existing algorithms, such as conventional MLEM and LSF-based MLEM. Simulations demonstrated that the WL-MLEM algorithm yielded higher spatial resolution and image quality than the existing algorithms. The WL-MLEM algorithm with wobbling PET yielded substantially improved resolution compared with conventional algorithms with stationary PET. The algorithm can be easily extended to other iterative reconstruction algorithms, such as maximum a priori (MAP) and ordered subset expectation maximization (OSEM). The WL-MLEM algorithm with wobbling PET may offer improvements in both sensitivity and resolution, the two most sought-after features in PET design. - Highlights: • This paper proposed WL-MLEM algorithm for PET and demonstrated its performance. • WL-MLEM algorithm effectively combined wobbling and line spread function based MLEM. • WL-MLEM provided improvements in the spatial resolution and the PET image quality. • WL-MLEM can be easily extended to the other iterative

  8. 18F-FET-PET in Primary Hyperparathyroidism

    DEFF Research Database (Denmark)

    Krakauer, Martin; Kjær, Andreas; Bennedbæk, Finn Noe

    2016-01-01

    -isotope parathyroid subtraction single photon emission computed tomography had determined the exact location of the parathyroid adenoma. A dynamic FET PET/CT scan was performed with subsequent visual evaluation and calculation of target-to-background (TBR; parathyroid vs. thyroid). The maximum TBR in the two patients......Preoperative localisation of the diseased parathyroid gland(s) in primary hyperparathyroidism (PHP) is a prerequisite for subsequent minimally invasive surgery. Recently, as alternatives to conventional sestamibi parathyroid scintigraphy, the (11)C-based positron emission tomography (PET) tracers...... methionine and choline have shown promise for this purpose. We evaluated the feasibility of using the (18)F-based PET tracer fluoroethyl-l-tyrosine (FET), as the longer half-life of (18)F makes it logistically more favourable. As a proof-of-concept study, we included two patients with PHP in which dual...

  9. Initial clinical evaluation of PET-based ion beam therapy monitoring under consideration of organ motion.

    Science.gov (United States)

    Kurz, Christopher; Bauer, Julia; Unholtz, Daniel; Richter, Daniel; Herfarth, Klaus; Debus, Jürgen; Parodi, Katia

    2016-02-01

    Intrafractional organ motion imposes considerable challenges to scanned ion beam therapy and demands for a thorough verification of the applied treatment. At the Heidelberg Ion-Beam Therapy Center (HIT), the scanned ion beam delivery is verified by means of postirradiation positron-emission-tomography (PET) imaging. This work presents a first clinical evaluation of PET-based treatment monitoring in ion beam therapy under consideration of target motion. Three patients with mobile liver lesions underwent scanned carbon ion irradiation at HIT and postirradiation PET/CT (x-ray-computed-tomography) imaging with a commercial scanner. Respiratory motion was recorded during irradiation and subsequent image acquisition. This enabled a time-resolved (4D) calculation of the expected irradiation-induced activity pattern and, for one patient where an additional 4D CT was acquired at the PET/CT scanner after treatment, a motion-compensated PET image reconstruction. For the other patients, PET data were reconstructed statically. To verify the treatment, calculated prediction and reconstructed measurement were compared with a focus on the ion beam range. Results in the current three patients suggest that for motion amplitudes in the order of 2 mm there is no benefit from incorporating respiratory motion information into PET-based treatment monitoring. For a target motion in the order of 10 mm, motion-related effects become more severe and a time-resolved modeling of the expected activity distribution can lead to an improved data interpretation if a sufficient number of true coincidences is detected. Benefits from motion-compensated PET image reconstruction could not be shown conclusively at the current stage. The feasibility of clinical PET-based treatment verification under consideration of organ motion has been shown for the first time. Improvements in noise-robust 4D PET image reconstruction are deemed necessary to enhance the clinical potential.

  10. Initial clinical evaluation of PET-based ion beam therapy monitoring under consideration of organ motion

    International Nuclear Information System (INIS)

    Kurz, Christopher; Bauer, Julia; Unholtz, Daniel; Herfarth, Klaus; Debus, Jürgen; Richter, Daniel; Parodi, Katia

    2016-01-01

    Purpose: Intrafractional organ motion imposes considerable challenges to scanned ion beam therapy and demands for a thorough verification of the applied treatment. At the Heidelberg Ion-Beam Therapy Center (HIT), the scanned ion beam delivery is verified by means of postirradiation positron-emission-tomography (PET) imaging. This work presents a first clinical evaluation of PET-based treatment monitoring in ion beam therapy under consideration of target motion. Methods: Three patients with mobile liver lesions underwent scanned carbon ion irradiation at HIT and postirradiation PET/CT (x-ray-computed-tomography) imaging with a commercial scanner. Respiratory motion was recorded during irradiation and subsequent image acquisition. This enabled a time-resolved (4D) calculation of the expected irradiation-induced activity pattern and, for one patient where an additional 4D CT was acquired at the PET/CT scanner after treatment, a motion-compensated PET image reconstruction. For the other patients, PET data were reconstructed statically. To verify the treatment, calculated prediction and reconstructed measurement were compared with a focus on the ion beam range. Results: Results in the current three patients suggest that for motion amplitudes in the order of 2 mm there is no benefit from incorporating respiratory motion information into PET-based treatment monitoring. For a target motion in the order of 10 mm, motion-related effects become more severe and a time-resolved modeling of the expected activity distribution can lead to an improved data interpretation if a sufficient number of true coincidences is detected. Benefits from motion-compensated PET image reconstruction could not be shown conclusively at the current stage. Conclusions: The feasibility of clinical PET-based treatment verification under consideration of organ motion has been shown for the first time. Improvements in noise-robust 4D PET image reconstruction are deemed necessary to enhance the

  11. Surface modification of PET film by plasma-based ion implantation

    International Nuclear Information System (INIS)

    Sakudo, N.; Mizutani, D.; Ohmura, Y.; Endo, H.; Yoneda, R.; Ikenaga, N.; Takikawa, H.

    2003-01-01

    It has been reported that thin diamond like carbon (DLC) coating is very Amsterdam, Theenhancing the barrier characteristics of polyethylene terephthalate (PET) against CO 2 and O 2 gases. However, coating technique has a problem of DLC-deposit peeling. In this research, we develop a new technique to change the PET surface into DLC by ion implantation instead of coating the surface with the DLC deposit. The surface of PET film is modified by plasma-based ion implantation using pulse voltages of 10 kV in height and 5 μs in width. Attenuated total reflection FT-IR spectroscopy shows that the specific absorption peaks for PET decrease with dose, that is, the molecules of ethylene terephthalate are destroyed by ion bombardment. Then, laser Raman spectroscopy shows that thin DLC layer is formed in the PET surface area

  12. MR-1S Interacts with PET100 and PET117 in Module-Based Assembly of Human Cytochrome c Oxidase

    Directory of Open Access Journals (Sweden)

    Sara Vidoni

    2017-02-01

    Full Text Available The biogenesis of human cytochrome c oxidase (COX is an intricate process in which three mitochondrial DNA (mtDNA-encoded core subunits are assembled in a coordinated way with at least 11 nucleus-encoded subunits. Many chaperones shared between yeast and humans are involved in COX assembly. Here, we have used a MT-CO3 mutant cybrid cell line to define the composition of assembly intermediates and identify new human COX assembly factors. Quantitative mass spectrometry analysis led us to modify the assembly model from a sequential pathway to a module-based process. Each module contains one of the three core subunits, together with different ancillary components, including HIGD1A. By the same analysis, we identified the short isoform of the myofibrillogenesis regulator 1 (MR-1S as a new COX assembly factor, which works with the highly conserved PET100 and PET117 chaperones to assist COX biogenesis in higher eukaryotes.

  13. Enhancement of dynamic myocardial perfusion PET images based on low-rank plus sparse decomposition.

    Science.gov (United States)

    Lu, Lijun; Ma, Xiaomian; Mohy-Ud-Din, Hassan; Ma, Jianhua; Feng, Qianjin; Rahmim, Arman; Chen, Wufan

    2018-02-01

    The absolute quantification of dynamic myocardial perfusion (MP) PET imaging is challenged by the limited spatial resolution of individual frame images due to division of the data into shorter frames. This study aims to develop a method for restoration and enhancement of dynamic PET images. We propose that the image restoration model should be based on multiple constraints rather than a single constraint, given the fact that the image characteristic is hardly described by a single constraint alone. At the same time, it may be possible, but not optimal, to regularize the image with multiple constraints simultaneously. Fortunately, MP PET images can be decomposed into a superposition of background vs. dynamic components via low-rank plus sparse (L + S) decomposition. Thus, we propose an L + S decomposition based MP PET image restoration model and express it as a convex optimization problem. An iterative soft thresholding algorithm was developed to solve the problem. Using realistic dynamic 82 Rb MP PET scan data, we optimized and compared its performance with other restoration methods. The proposed method resulted in substantial visual as well as quantitative accuracy improvements in terms of noise versus bias performance, as demonstrated in extensive 82 Rb MP PET simulations. In particular, the myocardium defect in the MP PET images had improved visual as well as contrast versus noise tradeoff. The proposed algorithm was also applied on an 8-min clinical cardiac 82 Rb MP PET study performed on the GE Discovery PET/CT, and demonstrated improved quantitative accuracy (CNR and SNR) compared to other algorithms. The proposed method is effective for restoration and enhancement of dynamic PET images. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. The progress of PET based reporter gene imaging

    International Nuclear Information System (INIS)

    Zhao Wei; Zhang Xiuli

    2005-01-01

    More than two decades of intense research have allowed gene therapy to move from the laboratory to the clinical setting, where its use for the treatment of human pathologies has been considerably increased in the last years. However, many crucial questions remain to be solved in this challenging field. In vivo imaging with positron emission tomography (PET) by combination of the appropriate PET reporter gene and PET reporter probe could provide invaluable qualitative and quantitative information to answer multiple unsolved questions about gene therapy. PET imaging could be used to define parameters not available by other techniques that are of substantial interest not only for the proper understanding of the gene therapy process, but also for its future development and clinical application in humans. (authors)

  15. MR/PET quantification tools: Registration, segmentation, classification, and MR-based attenuation correction

    Science.gov (United States)

    Fei, Baowei; Yang, Xiaofeng; Nye, Jonathon A.; Aarsvold, John N.; Raghunath, Nivedita; Cervo, Morgan; Stark, Rebecca; Meltzer, Carolyn C.; Votaw, John R.

    2012-01-01

    Purpose: Combined MR/PET is a relatively new, hybrid imaging modality. A human MR/PET prototype system consisting of a Siemens 3T Trio MR and brain PET insert was installed and tested at our institution. Its present design does not offer measured attenuation correction (AC) using traditional transmission imaging. This study is the development of quantification tools including MR-based AC for quantification in combined MR/PET for brain imaging. Methods: The developed quantification tools include image registration, segmentation, classification, and MR-based AC. These components were integrated into a single scheme for processing MR/PET data. The segmentation method is multiscale and based on the Radon transform of brain MR images. It was developed to segment the skull on T1-weighted MR images. A modified fuzzy C-means classification scheme was developed to classify brain tissue into gray matter, white matter, and cerebrospinal fluid. Classified tissue is assigned an attenuation coefficient so that AC factors can be generated. PET emission data are then reconstructed using a three-dimensional ordered sets expectation maximization method with the MR-based AC map. Ten subjects had separate MR and PET scans. The PET with [11C]PIB was acquired using a high-resolution research tomography (HRRT) PET. MR-based AC was compared with transmission (TX)-based AC on the HRRT. Seventeen volumes of interest were drawn manually on each subject image to compare the PET activities between the MR-based and TX-based AC methods. Results: For skull segmentation, the overlap ratio between our segmented results and the ground truth is 85.2 ± 2.6%. Attenuation correction results from the ten subjects show that the difference between the MR and TX-based methods was <6.5%. Conclusions: MR-based AC compared favorably with conventional transmission-based AC. Quantitative tools including registration, segmentation, classification, and MR-based AC have been developed for use in combined MR/PET

  16. MR/PET quantification tools: Registration, segmentation, classification, and MR-based attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Baowei, E-mail: bfei@emory.edu [Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1841 Clifton Road Northeast, Atlanta, Georgia 30329 (United States); Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322 (United States); Department of Mathematics and Computer Sciences, Emory University, Atlanta, Georgia 30322 (United States); Yang, Xiaofeng; Nye, Jonathon A.; Raghunath, Nivedita; Votaw, John R. [Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30329 (United States); Aarsvold, John N. [Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30329 (United States); Nuclear Medicine Service, Atlanta Veterans Affairs Medical Center, Atlanta, Georgia 30033 (United States); Cervo, Morgan; Stark, Rebecca [The Medical Physics Graduate Program in the George W. Woodruff School, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Meltzer, Carolyn C. [Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia 30329 (United States); Department of Neurology and Department of Psychiatry and Behavior Sciences, Emory University School of Medicine, Atlanta, Georgia 30322 (United States)

    2012-10-15

    Purpose: Combined MR/PET is a relatively new, hybrid imaging modality. A human MR/PET prototype system consisting of a Siemens 3T Trio MR and brain PET insert was installed and tested at our institution. Its present design does not offer measured attenuation correction (AC) using traditional transmission imaging. This study is the development of quantification tools including MR-based AC for quantification in combined MR/PET for brain imaging. Methods: The developed quantification tools include image registration, segmentation, classification, and MR-based AC. These components were integrated into a single scheme for processing MR/PET data. The segmentation method is multiscale and based on the Radon transform of brain MR images. It was developed to segment the skull on T1-weighted MR images. A modified fuzzy C-means classification scheme was developed to classify brain tissue into gray matter, white matter, and cerebrospinal fluid. Classified tissue is assigned an attenuation coefficient so that AC factors can be generated. PET emission data are then reconstructed using a three-dimensional ordered sets expectation maximization method with the MR-based AC map. Ten subjects had separate MR and PET scans. The PET with [{sup 11}C]PIB was acquired using a high-resolution research tomography (HRRT) PET. MR-based AC was compared with transmission (TX)-based AC on the HRRT. Seventeen volumes of interest were drawn manually on each subject image to compare the PET activities between the MR-based and TX-based AC methods. Results: For skull segmentation, the overlap ratio between our segmented results and the ground truth is 85.2 ± 2.6%. Attenuation correction results from the ten subjects show that the difference between the MR and TX-based methods was <6.5%. Conclusions: MR-based AC compared favorably with conventional transmission-based AC. Quantitative tools including registration, segmentation, classification, and MR-based AC have been developed for use in combined MR/PET.

  17. MR/PET quantification tools: Registration, segmentation, classification, and MR-based attenuation correction

    International Nuclear Information System (INIS)

    Fei, Baowei; Yang, Xiaofeng; Nye, Jonathon A.; Raghunath, Nivedita; Votaw, John R.; Aarsvold, John N.; Cervo, Morgan; Stark, Rebecca; Meltzer, Carolyn C.

    2012-01-01

    Purpose: Combined MR/PET is a relatively new, hybrid imaging modality. A human MR/PET prototype system consisting of a Siemens 3T Trio MR and brain PET insert was installed and tested at our institution. Its present design does not offer measured attenuation correction (AC) using traditional transmission imaging. This study is the development of quantification tools including MR-based AC for quantification in combined MR/PET for brain imaging. Methods: The developed quantification tools include image registration, segmentation, classification, and MR-based AC. These components were integrated into a single scheme for processing MR/PET data. The segmentation method is multiscale and based on the Radon transform of brain MR images. It was developed to segment the skull on T1-weighted MR images. A modified fuzzy C-means classification scheme was developed to classify brain tissue into gray matter, white matter, and cerebrospinal fluid. Classified tissue is assigned an attenuation coefficient so that AC factors can be generated. PET emission data are then reconstructed using a three-dimensional ordered sets expectation maximization method with the MR-based AC map. Ten subjects had separate MR and PET scans. The PET with ["1"1C]PIB was acquired using a high-resolution research tomography (HRRT) PET. MR-based AC was compared with transmission (TX)-based AC on the HRRT. Seventeen volumes of interest were drawn manually on each subject image to compare the PET activities between the MR-based and TX-based AC methods. Results: For skull segmentation, the overlap ratio between our segmented results and the ground truth is 85.2 ± 2.6%. Attenuation correction results from the ten subjects show that the difference between the MR and TX-based methods was <6.5%. Conclusions: MR-based AC compared favorably with conventional transmission-based AC. Quantitative tools including registration, segmentation, classification, and MR-based AC have been developed for use in combined MR/PET.

  18. Influence of expanded graphite (EG) and graphene oxide (GO) on physical properties of PET based nanocomposites

    OpenAIRE

    Paszkiewicz Sandra; Nachman Małgorzata; Szymczyk Anna; Špitalský Zdeno; Mosnáček Jaroslav; Rosłaniec Zbigniew

    2014-01-01

    This work is the continuation and refinement of already published communications based on PET/EG nanocomposites prepared by in situ polymerization1, 2. In this study, nanocomposites based on poly(ethylene terephthalate) with expanded graphite were compared to those with functionalized graphite sheets (GO). The results suggest that the degree of dispersion of nanoparticles in the PET matrix has important effect on the structure and physical properties of the nanocomposites. The existence of gr...

  19. Development of a SiPM-based PET imaging system for small animals

    International Nuclear Information System (INIS)

    Lu, Yanye; Yang, Kun; Zhou, Kedi; Zhang, Qiushi; Pang, Bo; Ren, Qiushi

    2014-01-01

    Advances in small animal positron emission tomography (PET) imaging have been accelerated by many new technologies such as the successful incorporation of silicon photomultiplier (SiPM). In this paper, we have developed a compact, lightweight PET imaging system that is based on SiPM detectors for small animals imaging, which could be integrated into a multi-modality imaging system. This PET imaging system consists of a stationary detector gantry, a motor-controlled animal bed module, electronics modules, and power supply modules. The PET detector, which was designed as a multi-slice circular ring geometry of 27 discrete block detectors, is composed of a cerium doped lutetium–yttrium oxyorthosilicate (LYSO) scintillation crystal and SiPM arrays. The system has a 60 mm transaxial field of view (FOV) and a 26 mm axial FOV. Performance tests (e.g. spatial resolution, energy resolution, and sensitivity) and phantom and animal imaging studies were performed to evaluate the imaging performance of the PET imaging system. The performance tests and animal imaging results demonstrate the feasibility of an animal PET system based on SiPM detectors and indicate that SiPM detectors can be promising photodetectors in animal PET instrumentation development

  20. Development of a SiPM-based PET imaging system for small animals

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yanye [Department of Biomedicine and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Yang, Kun, E-mail: yangkun9999@hotmail.com [Department of Control Technology and Instrumentation, College of Quality and Technical Supervision, Hebei University, Baoding, 071000 (China); Zhou, Kedi; Zhang, Qiushi; Pang, Bo [Department of Biomedicine and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Ren, Qiushi, E-mail: renqsh@coe.pku.edu.cn [Department of Biomedicine and Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2014-04-11

    Advances in small animal positron emission tomography (PET) imaging have been accelerated by many new technologies such as the successful incorporation of silicon photomultiplier (SiPM). In this paper, we have developed a compact, lightweight PET imaging system that is based on SiPM detectors for small animals imaging, which could be integrated into a multi-modality imaging system. This PET imaging system consists of a stationary detector gantry, a motor-controlled animal bed module, electronics modules, and power supply modules. The PET detector, which was designed as a multi-slice circular ring geometry of 27 discrete block detectors, is composed of a cerium doped lutetium–yttrium oxyorthosilicate (LYSO) scintillation crystal and SiPM arrays. The system has a 60 mm transaxial field of view (FOV) and a 26 mm axial FOV. Performance tests (e.g. spatial resolution, energy resolution, and sensitivity) and phantom and animal imaging studies were performed to evaluate the imaging performance of the PET imaging system. The performance tests and animal imaging results demonstrate the feasibility of an animal PET system based on SiPM detectors and indicate that SiPM detectors can be promising photodetectors in animal PET instrumentation development.

  1. Comparison of [11C]choline Positron Emission Tomography With T2- and Diffusion-Weighted Magnetic Resonance Imaging for Delineating Malignant Intraprostatic Lesions

    International Nuclear Information System (INIS)

    Chang, Joe H.; Lim Joon, Daryl; Davis, Ian D.; Lee, Sze Ting; Hiew, Chee-Yan; Esler, Stephen; Gong, Sylvia J.; Wada, Morikatsu; Clouston, David; O'Sullivan, Richard; Goh, Yin P.; Bolton, Damien; Scott, Andrew M.; Khoo, Vincent

    2015-01-01

    Purpose: The purpose of this study was to compare the accuracy of [ 11 C]choline positron emission tomography (CHOL-PET) with that of the combination of T2-weighted and diffusion-weighted (T2W/DW) magnetic resonance imaging (MRI) for delineating malignant intraprostatic lesions (IPLs) for guiding focal therapies and to investigate factors predicting the accuracy of CHOL-PET. Methods and Materials: This study included 21 patients who underwent CHOL-PET and T2W/DW MRI prior to radical prostatectomy. Two observers manually delineated IPL contours for each scan, and automatic IPL contours were generated on CHOL-PET based on varying proportions of the maximum standardized uptake value (SUV). IPLs identified on prostatectomy specimens defined reference standard contours. The imaging-based contours were compared with the reference standard contours using Dice similarity coefficient (DSC), and sensitivity and specificity values. Factors that could potentially predict the DSC of the best contouring method were analyzed using linear models. Results: The best automatic contouring method, 60% of the maximum SUV (SUV 60 ) , had similar correlations (DSC: 0.59) with the manual PET contours (DSC: 0.52, P=.127) and significantly better correlations than the manual MRI contours (DSC: 0.37, P<.001). The sensitivity and specificity values were 72% and 71% for SUV 60 ; 53% and 86% for PET manual contouring; and 28% and 92% for MRI manual contouring. The tumor volume and transition zone pattern could independently predict the accuracy of CHOL-PET. Conclusions: CHOL-PET is superior to the combination of T2W/DW MRI for delineating IPLs. The accuracy of CHOL-PET is insufficient for gland-sparing focal therapies but may be accurate enough for focal boost therapies. The transition zone pattern is a new classification that may predict how well CHOL-PET delineates IPLs

  2. Evaluation of a video-based head motion tracking system for dedicated brain PET

    Science.gov (United States)

    Anishchenko, S.; Beylin, D.; Stepanov, P.; Stepanov, A.; Weinberg, I. N.; Schaeffer, S.; Zavarzin, V.; Shaposhnikov, D.; Smith, M. F.

    2015-03-01

    Unintentional head motion during Positron Emission Tomography (PET) data acquisition can degrade PET image quality and lead to artifacts. Poor patient compliance, head tremor, and coughing are examples of movement sources. Head motion due to patient non-compliance can be an issue with the rise of amyloid brain PET in dementia patients. To preserve PET image resolution and quantitative accuracy, head motion can be tracked and corrected in the image reconstruction algorithm. While fiducial markers can be used, a contactless approach is preferable. A video-based head motion tracking system for a dedicated portable brain PET scanner was developed. Four wide-angle cameras organized in two stereo pairs are used for capturing video of the patient's head during the PET data acquisition. Facial points are automatically tracked and used to determine the six degree of freedom head pose as a function of time. The presented work evaluated the newly designed tracking system using a head phantom and a moving American College of Radiology (ACR) phantom. The mean video-tracking error was 0.99±0.90 mm relative to the magnetic tracking device used as ground truth. Qualitative evaluation with the ACR phantom shows the advantage of the motion tracking application. The developed system is able to perform tracking with accuracy close to millimeter and can help to preserve resolution of brain PET images in presence of movements.

  3. The Investigation of Electrochemistry Behaviors of Tyrosinase Based on Directly-Electrodeposited Grapheneon Choline-Gold Nanoparticles.

    Science.gov (United States)

    He, Yaping; Yang, Xiaohui; Han, Quan; Zheng, Jianbin

    2017-06-23

    A novel catechol (CA) biosensor was developed by embedding tyrosinase (Tyr) onto in situ electrochemical reduction graphene (EGR) on choline-functionalized gold nanoparticle (AuNPs-Ch) film. The results of UV-Vis spectra indicated that Tyr retained its original structure in the film, and an electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with E pa = -0.0744 V and E pc = -0.114 V (vs. SCE) in 0.1 M, pH 7.0 sodium phosphate-buffered saline at a scan rate of 100 mV/s. The transfer rate constant k s is 0.66 s -1 . The Tyr-EGR/AuNPs-Ch showed a good electrochemical catalytic response for the reduction of CA, with the linear range from 0.2 to 270 μM and a detection limit of 0.1 μM (S/N = 3). The apparent Michaelis-Menten constant was estimated to be 109 μM.

  4. Markov random field and Gaussian mixture for segmented MRI-based partial volume correction in PET

    International Nuclear Information System (INIS)

    Bousse, Alexandre; Thomas, Benjamin A; Erlandsson, Kjell; Hutton, Brian F; Pedemonte, Stefano; Ourselin, Sébastien; Arridge, Simon

    2012-01-01

    In this paper we propose a segmented magnetic resonance imaging (MRI) prior-based maximum penalized likelihood deconvolution technique for positron emission tomography (PET) images. The model assumes the existence of activity classes that behave like a hidden Markov random field (MRF) driven by the segmented MRI. We utilize a mean field approximation to compute the likelihood of the MRF. We tested our method on both simulated and clinical data (brain PET) and compared our results with PET images corrected with the re-blurred Van Cittert (VC) algorithm, the simplified Guven (SG) algorithm and the region-based voxel-wise (RBV) technique. We demonstrated our algorithm outperforms the VC algorithm and outperforms SG and RBV corrections when the segmented MRI is inconsistent (e.g. mis-segmentation, lesions, etc) with the PET image. (paper)

  5. Influence of expanded graphite (EG and graphene oxide (GO on physical properties of PET based nanocomposites

    Directory of Open Access Journals (Sweden)

    Paszkiewicz Sandra

    2014-12-01

    Full Text Available This work is the continuation and refinement of already published communications based on PET/EG nanocomposites prepared by in situ polymerization1, 2. In this study, nanocomposites based on poly(ethylene terephthalate with expanded graphite were compared to those with functionalized graphite sheets (GO. The results suggest that the degree of dispersion of nanoparticles in the PET matrix has important effect on the structure and physical properties of the nanocomposites. The existence of graphene sheets nanoparticles enhances the crystallization rate of PET. It has been confirmed that in situ polymerization is the effective method for preparation nanocomposites which can avoid the agglomeration of nanoparticles in polymer matrices and improve the interfacial interaction between nanofiller and polymer matrix. The obtained results have shown also that due to the presence of functional groups on GO surface the interactions with PET matrix can be stronger than in the case of exfoliated graphene (EG and matrix.

  6. PET-Based Personalized Management of Infectious and Inflammatory Disorders

    DEFF Research Database (Denmark)

    Hess, Søren; Alavi, Abass; Basu, Sandip

    2016-01-01

    It is challenging to diagnose and manage infectious and inflammatory diseases; symptoms are relatively nonspecific, the disease patterns are often systemic. Imaging is pivotal and fluorodeoxyglucose (FDG)-PET/computed tomography (CT) is increasingly used due to its high sensitivity whole-body app......It is challenging to diagnose and manage infectious and inflammatory diseases; symptoms are relatively nonspecific, the disease patterns are often systemic. Imaging is pivotal and fluorodeoxyglucose (FDG)-PET/computed tomography (CT) is increasingly used due to its high sensitivity whole...

  7. Heredity, pet ownership, and confounding control in a population-based birth cohort.

    Science.gov (United States)

    Almqvist, Catarina; Egmar, Ann-Charlotte; van Hage-Hamsten, Marianne; Berglind, Niklas; Pershagen, Göran; Nordvall, S Lennart; Svartengren, Magnus; Hedlin, Gunilla; Wickman, Magnus

    2003-04-01

    The association between pet ownership in childhood and subsequent allergic disease is controversial. Bias related to selection of pet exposure has been suggested as a reason for contradictory study results. The purpose of this investigation was to elucidate how pet exposure depends on family history of allergic disease, smoking, and socioeconomic factors in a prospective birth cohort. Parents of 4089 two-month-old children answered a questionnaire that included detailed questions about family history of asthma (maternal, paternal, and sibling), rhinoconjunctivitis, atopic eczema/dermatitis syndrome, pollen and pet allergy, smoking habits, parental occupation, and family pet ownership (cat and dog). Dust samples collected from the mothers' beds were analyzed for Fel d 1 and Can f 1 in a subgroup of the cohort. Cats were less frequently kept in families with parental asthma, rhinoconjunctivitis, or pet or pollen allergy (3.5% to 5.8%) than in families without parental allergic disease (10.8% to 11.8%). Dogs were less common in families with (3.3%) than in families without (5.9%) parental atopic eczema/dermatitis syndrome. Families with smoking mothers and those with low socioeconomic index kept cats and dogs more frequently. Cat allergen levels were lower in homes with than in homes without maternal pet allergy, and this tended to hold true even for homes without a cat. Cat ownership decreased from birth to 2 years of age, especially in families with parental history of allergic diseases. There seems to be a selection of pet exposure based on parental history of allergy, maternal smoking, and socioeconomic factors. This has to be taken into consideration in evaluations of risk associations between pet exposure and allergic disease in childhood.

  8. Distribution of prostate nodes: a PET/CT-derived anatomic atlas of prostate cancer patients before and after surgical treatment.

    Science.gov (United States)

    Hegemann, Nina-Sophie; Wenter, Vera; Spath, Sonja; Kusumo, Nadia; Li, Minglun; Bartenstein, Peter; Fendler, Wolfgang P; Stief, Christian; Belka, Claus; Ganswindt, Ute

    2016-03-11

    In order to define adequate radiation portals in nodal positive prostate cancer a detailed knowledge of the anatomic lymph-node distribution is mandatory. We therefore systematically analyzed the localization of Choline PET/CT positive lymph nodes and compared it to the RTOG recommendation of pelvic CTV, as well as to previous work, the SPECT sentinel lymph node atlas. Thirty-two patients being mostly high risk patients with a PSA of 12.5 ng/ml (median) received PET/CT before any treatment. Eighty-seven patients received PET/CT for staging due to biochemical failure with a median PSA of 3.12 ng/ml. Each single PET-positive lymph node was manually contoured in a "virtual" patient dataset to achieve a 3-D visualization, resulting in an atlas of the cumulative PET positive lymph node distribution. Further the PET-positive lymph node location in each patient was assessed with regard to the existence of a potential geographic miss (i.e. PET-positive lymph nodes that would not have been treated adequately by the RTOG consensus on CTV definition of pelvic lymph nodes). Seventy-eight and 209 PET positive lymph nodes were detected in patients with no prior treatment and in postoperative patients, respectively. The most common sites of PET positive lymph nodes in patients with no prior treatment were external iliac (32.1 %), followed by common iliac (23.1 %) and para-aortic (19.2 %). In postoperative patients the most common sites of PET positive lymph nodes were common iliac (24.9 %), followed by external iliac (23.0 %) and para-aortic (20.1 %). In patients with no prior treatment there were 34 (43.6 %) and in postoperative patients there were 77 (36.8 %) of all detected lymph nodes that would not have been treated adequately using the RTOG CTV. We compared the distribution of lymph nodes gained by Choline PET/CT to the preexisting SPECT sentinel lymph node atlas and saw an overall good congruence. Choline PET/CT and SPECT sentinel lymph node atlas are comparable to each

  9. MR-based attenuation correction in brain PET based on UTE sequences

    Energy Technology Data Exchange (ETDEWEB)

    Cabello, Jorge; Nekolla, Stephan G; Ziegler, Sibylle I [Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München (Germany)

    2014-07-29

    Attenuation correction (AC) in brain PET/MR has recently emerged as one of the challenging tasks in the PET/MR field. It has been shown that to ignore the attenuation produced by bone can lead to errors ranging from 5-30% in regions close to bone structures. Since the information provided by the MR signal is not directly related to tissue attenuation, alternative methods have to be developed. Signal from bone tissue is difficult to measure given its short transverse relaxation time (T2). Ultrashort-echo time (UTE) pulse sequences were developed to measure signal from tissues with short T2. A combination of two consecutive UTE echoes has been used in several works to measure signal from bone tissue. The first echo is able to measure signal from bone tissue in addition to soft tissue, while the second echo contains most of the soft tissue contained in the first echo but not bone. In this work we extract the attenuation information from the difference between the logarithm of two images obtained after applying two consecutive UTE pulse sequences using the mMR scanner (Siemens Healthcare). Subsequently, image processing techniques are applied to reduce the noise and extract air cavities within the head. The resulting image is converted to linear attenuation coefficients, generating what is known as µ-map, to be used during reconstruction. For comparison purposes PET/CT scans of the same patients were acquired prior to the PET/MR scan. Additional µ-maps obtained for comparison were extracted from a Dixon sequence (used in clinical routine) and an additional µ-map calculated by the scanner based on UTE pulse sequences. Preliminary quantitative results measured in the cerebellum, using the value obtained with CT-based AC as reference, show differences of 34% without AC, 13% using the Dixon-based and UTE-based provided by the scanner, and 0.8% with the AC strategy presented here.

  10. An experimental phantom study of the effect of gadolinium-based MR contrast agents on PET attenuation coefficients and PET quantification in PET-MR imaging: application to cardiac studies.

    Science.gov (United States)

    O' Doherty, Jim; Schleyer, Paul

    2017-12-01

    Simultaneous cardiac perfusion studies are an increasing trend in PET-MR imaging. During dynamic PET imaging, the introduction of gadolinium-based MR contrast agents (GBCA) at high concentrations during a dual injection of GBCA and PET radiotracer may cause increased attenuation effects of the PET signal, and thus errors in quantification of PET images. We thus aimed to calculate the change in linear attenuation coefficient (LAC) of a mixture of PET radiotracer and increasing concentrations of GBCA in solution and furthermore, to investigate if this change in LAC produced a measurable effect on the image-based PET activity concentration when attenuation corrected by three different AC strategies. We performed simultaneous PET-MR imaging of a phantom in a static scenario using a fixed activity of 40 MBq [18 F]-NaF, water, and an increasing GBCA concentration from 0 to 66 mM (based on an assumed maximum possible concentration of GBCA in the left ventricle in a clinical study). This simulated a range of clinical concentrations of GBCA. We investigated two methods to calculate the LAC of the solution mixture at 511 keV: (1) a mathematical mixture rule and (2) CT imaging of each concentration step and subsequent conversion to LAC at 511 keV. This comparison showed that the ranges of LAC produced by both methods are equivalent with an increase in LAC of the mixed solution of approximately 2% over the range of 0-66 mM. We then employed three different attenuation correction methods to the PET data: (1) each PET scan at a specific millimolar concentration of GBCA corrected by its corresponding CT scan, (2) each PET scan corrected by a CT scan with no GBCA present (i.e., at 0 mM GBCA), and (3) a manually generated attenuation map, whereby all CT voxels in the phantom at 0 mM were replaced by LAC = 0.1 cm -1 . All attenuation correction methods (1-3) were accurate to the true measured activity concentration within 5%, and there were no trends in image-based

  11. SiliPET: An ultra high resolution design of a small animal PET scanner based on double sided silicon strip detector stacks

    International Nuclear Information System (INIS)

    Zavattini, G.; Cesca, N.; Di Domenico, G.; Moretti, E.; Sabba, N.

    2006-01-01

    We investigated the capabilities of a small animal PET scanner, named SiliPET, based on four stacks of double sided silicon strips detectors. Each stack consists of 40 silicon detectors with dimension 60x60x1mm 3 . These are arranged to form a box 5x5x6cm 3 with minor sides opened; the box represents the maximal FOV of the scanner. The performance parameters of SiliPET scanner have been estimated, giving an intrinsic spatial resolution of 0.52mm and a sensitivity of 5.1% at the center of the system

  12. FDG-PET/CT based response-adapted treatment

    DEFF Research Database (Denmark)

    de Geus-Oei, Lioe-Fee; Vriens, Dennis; Arens, Anne I J

    2012-01-01

    It has been shown that [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) provides robust and reproducible data for early metabolic response assessment in various malignancies. This led to the initiation of several prospective multicenter trials in malignant lymphoma and adenocarc...

  13. Degradation of recycled PET fibers in Portland cement-based materials

    International Nuclear Information System (INIS)

    Silva, D.A.; Betioli, A.M.; Gleize, P.J.P.; Roman, H.R.; Gomez, L.A.; Ribeiro, J.L.D.

    2005-01-01

    In order to investigate the durability of recycled PET fibers embedded in cement-based materials, fiber-reinforced mortar specimens were tested until 164 days after mixing. Compressive, tensile, and flexural strengths, elasticity modulus, and toughness of the specimens were determined. The mortars were also analyzed by SEM. The results have shown that PET fibers have no significant influence on mortars strengths and elasticity modulus. However, the toughness indexes I 5 , I 10 , and I 20 decreased with time due to the degradation of PET fibers by alkaline hydrolysis when embedded in the cement matrix. Fourier transform infrared spectroscopy (FT-IR) and SEM analysis of PET fibers immersed and kept for 150 days in alkaline solutions supported the conclusions

  14. SBML-PET-MPI: a parallel parameter estimation tool for Systems Biology Markup Language based models.

    Science.gov (United States)

    Zi, Zhike

    2011-04-01

    Parameter estimation is crucial for the modeling and dynamic analysis of biological systems. However, implementing parameter estimation is time consuming and computationally demanding. Here, we introduced a parallel parameter estimation tool for Systems Biology Markup Language (SBML)-based models (SBML-PET-MPI). SBML-PET-MPI allows the user to perform parameter estimation and parameter uncertainty analysis by collectively fitting multiple experimental datasets. The tool is developed and parallelized using the message passing interface (MPI) protocol, which provides good scalability with the number of processors. SBML-PET-MPI is freely available for non-commercial use at http://www.bioss.uni-freiburg.de/cms/sbml-pet-mpi.html or http://sites.google.com/site/sbmlpetmpi/.

  15. Experimental investigation of irregular motion impact on 4D PET-based particle therapy monitoring

    International Nuclear Information System (INIS)

    Tian, Y; Stützer, K; Enghardt, W; Priegnitz, M; Helmbrecht, S; Fiedler, F; Bert, C

    2016-01-01

    Particle therapy positron emission tomography (PT-PET) is an in vivo and non-invasive imaging technique to monitor treatment delivery in particle therapy. The inevitable patient respiratory motion during irradiation causes artefacts and inaccurate activity distribution in PET images. Four-dimensional (4D) maximum likelihood expectation maximisation (4D MLEM) allows for a compensation of these effects, but has up to now been restricted to regular motion for PT-PET investigations. However, intra-fractional motion during treatment might differ from that during acquisition of the 4D-planning CT (e.g. amplitude variation, baseline drift) and therefore might induce inaccurate 4D PET reconstruction results. This study investigates the impact of different irregular analytical one-dimensional (1D) motion patterns on PT-PET imaging by means of experiments with a radioactive source and irradiated moving phantoms. Three sorting methods, namely phase sorting, equal amplitude sorting and event-based amplitude sorting, were applied to manage the PET list-mode data. The influence of these sorting methods on the motion compensating algorithm has been analysed. The event-based amplitude sorting showed a superior performance and it is applicable for irregular motions with  ⩽4 mm amplitude elongation and drift. For motion with 10 mm baseline drift, the normalised root mean square error was as high as 10.5% and a 10 mm range deviation was observed. (note)

  16. Experimental investigation of irregular motion impact on 4D PET-based particle therapy monitoring

    Science.gov (United States)

    Tian, Y.; Stützer, K.; Enghardt, W.; Priegnitz, M.; Helmbrecht, S.; Bert, C.; Fiedler, F.

    2016-01-01

    Particle therapy positron emission tomography (PT-PET) is an in vivo and non-invasive imaging technique to monitor treatment delivery in particle therapy. The inevitable patient respiratory motion during irradiation causes artefacts and inaccurate activity distribution in PET images. Four-dimensional (4D) maximum likelihood expectation maximisation (4D MLEM) allows for a compensation of these effects, but has up to now been restricted to regular motion for PT-PET investigations. However, intra-fractional motion during treatment might differ from that during acquisition of the 4D-planning CT (e.g. amplitude variation, baseline drift) and therefore might induce inaccurate 4D PET reconstruction results. This study investigates the impact of different irregular analytical one-dimensional (1D) motion patterns on PT-PET imaging by means of experiments with a radioactive source and irradiated moving phantoms. Three sorting methods, namely phase sorting, equal amplitude sorting and event-based amplitude sorting, were applied to manage the PET list-mode data. The influence of these sorting methods on the motion compensating algorithm has been analysed. The event-based amplitude sorting showed a superior performance and it is applicable for irregular motions with  ⩽4 mm amplitude elongation and drift. For motion with 10 mm baseline drift, the normalised root mean square error was as high as 10.5% and a 10 mm range deviation was observed.

  17. Initial clinical results for breath-hold CT-based processing of respiratory-gated PET acquisitions

    International Nuclear Information System (INIS)

    Fin, Loic; Daouk, Joel; Morvan, Julie; Esper, Isabelle El; Saidi, Lazhar; Meyer, Marc-Etienne; Bailly, Pascal

    2008-01-01

    Respiratory motion causes uptake in positron emission tomography (PET) images of chest structures to spread out and misregister with the CT images. This misregistration can alter the attenuation correction and thus the quantisation of PET images. In this paper, we present the first clinical results for a respiratory-gated PET (RG-PET) processing method based on a single breath-hold CT (BH-CT) acquisition, which seeks to improve diagnostic accuracy via better PET-to-CT co-registration. We refer to this method as ''CT-based'' RG-PET processing. Thirteen lesions were studied. Patients underwent a standard clinical PET protocol and then the CT-based protocol, which consists of a 10-min List Mode RG-PET acquisition, followed by a shallow end-expiration BH-CT. The respective performances of the CT-based and clinical PET methods were evaluated by comparing the distances between the lesions' centroids on PET and CT images. SUV MAX and volume variations were also investigated. The CT-based method showed significantly lower (p=0.027) centroid distances (mean change relative to the clinical method =-49%; range =-100% to 0%). This led to higher SUV MAX (mean change =+33%; range =-4% to 69%). Lesion volumes were significantly lower (p=0.022) in CT-based PET volumes (mean change =-39%: range =-74% to -1%) compared with clinical ones. A CT-based RG-PET processing method can be implemented in clinical practice with a small increase in radiation exposure. It improves PET-CT co-registration of lung lesions and should lead to more accurate attenuation correction and thus SUV measurement. (orig.)

  18. Radiosynthesis and pre-clinical evaluation of [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Graham [Comprehensive Cancer Imaging Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Zhao Yongjun [MDx Discovery (part of GE Healthcare) at Hammersmith Imanet, Ltd., Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Leyton, Julius [Comprehensive Cancer Imaging Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Shan Bo [MDx Discovery (part of GE Healthcare) at Hammersmith Imanet, Ltd., Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Nguyen, Quang-de; Perumal, Meg [Comprehensive Cancer Imaging Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Turton, David [GE-Imanet, Hammersmith Hospital, Du Cane Road, London, W12 0NN (United Kingdom); Arstad, Erik; Luthra, Sajinder K.; Robins, Edward G. [MDx Discovery (part of GE Healthcare) at Hammersmith Imanet, Ltd., Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Aboagye, Eric O., E-mail: eric.aboagye@imperial.ac.u [Comprehensive Cancer Imaging Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom)

    2011-01-15

    Introduction: Choline radiotracers are widely used for clinical PET diagnosis in oncology. [{sup 11}C]Choline finds particular utility in the imaging of brain and prostate tumor metabolic status, where 2-[{sup 18}F]fluoro-2-deoxy-D-glucose ('FDG') shows high background uptake. More recently we have extended the clinical utility of [{sup 11}C]choline to breast cancer where radiotracer uptake correlates with tumor aggressiveness (grade). In the present study, a new choline analog, [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline, was synthesized and evaluated as a potential PET imaging probe. Methods: [{sup 18}F]Fluorocholine, [{sup 18}F]fluoro-[1-{sup 2}H{sub 2}]choline and [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline were synthesized by alkylation of the relevant precursor with [{sup 18}F]fluorobromomethane or [{sup 18}F]fluoromethyl tosylate. Radiosynthesis of [{sup 18}F]fluoromethyl tosylate required extensive modification of the existing method. [{sup 18}F]Fluorocholine and [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline were then subjected to in vitro oxidative stability analysis in a chemical oxidation model using potassium permanganate and an enzymatic model using choline oxidase. The two radiotracers, together with the corresponding di-deuterated compound, [{sup 18}F]fluoro-[1-{sup 2}H{sub 2}]choline, were then evaluated in vivo in a time-course biodistribution study in HCT-116 tumor-bearing mice. Results: Alkylation with [{sup 18}F]fluoromethyl tosylate proved to be the most reliable radiosynthetic route. Stability models indicate that [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline possesses increased chemical and enzymatic (choline oxidase) oxidative stability relative to [{sup 18}F]fluorocholine. The distribution of the three radiotracers, [{sup 18}F]fluorocholine, [{sup 18}F]fluoro-[1-{sup 2}H{sub 2}]choline and [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline, showed a similar uptake profile in most organs. Crucially, tumor uptake of [{sup 18}F

  19. Evaluation of GMI and PMI diffeomorphic‐based demons algorithms for aligning PET and CT Images

    Science.gov (United States)

    Yang, Juan; Zhang, You; Yin, Yong

    2015-01-01

    Fusion of anatomic information in computed tomography (CT) and functional information in F18‐FDG positron emission tomography (PET) is crucial for accurate differentiation of tumor from benign masses, designing radiotherapy treatment plan and staging of cancer. Although current PET and CT images can be acquired from combined F18‐FDG PET/CT scanner, the two acquisitions are scanned separately and take a long time, which may induce potential positional errors in global and local caused by respiratory motion or organ peristalsis. So registration (alignment) of whole‐body PET and CT images is a prerequisite for their meaningful fusion. The purpose of this study was to assess the performance of two multimodal registration algorithms for aligning PET and CT images. The proposed gradient of mutual information (GMI)‐based demons algorithm, which incorporated the GMI between two images as an external force to facilitate the alignment, was compared with the point‐wise mutual information (PMI) diffeomorphic‐based demons algorithm whose external force was modified by replacing the image intensity difference in diffeomorphic demons algorithm with the PMI to make it appropriate for multimodal image registration. Eight patients with esophageal cancer(s) were enrolled in this IRB‐approved study. Whole‐body PET and CT images were acquired from a combined F18‐FDG PET/CT scanner for each patient. The modified Hausdorff distance (dMH) was used to evaluate the registration accuracy of the two algorithms. Of all patients, the mean values and standard deviations (SDs) of dMH were 6.65 (± 1.90) voxels and 6.01 (± 1.90) after the GMI‐based demons and the PMI diffeomorphic‐based demons registration algorithms respectively. Preliminary results on oncological patients showed that the respiratory motion and organ peristalsis in PET/CT esophageal images could not be neglected, although a combined F18‐FDG PET/CT scanner was used for image acquisition. The PMI

  20. Evaluation of GMI and PMI diffeomorphic-based demons algorithms for aligning PET and CT Images.

    Science.gov (United States)

    Yang, Juan; Wang, Hongjun; Zhang, You; Yin, Yong

    2015-07-08

    Fusion of anatomic information in computed tomography (CT) and functional information in 18F-FDG positron emission tomography (PET) is crucial for accurate differentiation of tumor from benign masses, designing radiotherapy treatment plan and staging of cancer. Although current PET and CT images can be acquired from combined 18F-FDG PET/CT scanner, the two acquisitions are scanned separately and take a long time, which may induce potential positional errors in global and local caused by respiratory motion or organ peristalsis. So registration (alignment) of whole-body PET and CT images is a prerequisite for their meaningful fusion. The purpose of this study was to assess the performance of two multimodal registration algorithms for aligning PET and CT images. The proposed gradient of mutual information (GMI)-based demons algorithm, which incorporated the GMI between two images as an external force to facilitate the alignment, was compared with the point-wise mutual information (PMI) diffeomorphic-based demons algorithm whose external force was modified by replacing the image intensity difference in diffeomorphic demons algorithm with the PMI to make it appropriate for multimodal image registration. Eight patients with esophageal cancer(s) were enrolled in this IRB-approved study. Whole-body PET and CT images were acquired from a combined 18F-FDG PET/CT scanner for each patient. The modified Hausdorff distance (d(MH)) was used to evaluate the registration accuracy of the two algorithms. Of all patients, the mean values and standard deviations (SDs) of d(MH) were 6.65 (± 1.90) voxels and 6.01 (± 1.90) after the GMI-based demons and the PMI diffeomorphic-based demons registration algorithms respectively. Preliminary results on oncological patients showed that the respiratory motion and organ peristalsis in PET/CT esophageal images could not be neglected, although a combined 18F-FDG PET/CT scanner was used for image acquisition. The PMI diffeomorphic-based demons

  1. Toward implementing an MRI-based PET attenuation-correction method for neurologic studies on the MR-PET brain prototype.

    Science.gov (United States)

    Catana, Ciprian; van der Kouwe, Andre; Benner, Thomas; Michel, Christian J; Hamm, Michael; Fenchel, Matthias; Fischl, Bruce; Rosen, Bruce; Schmand, Matthias; Sorensen, A Gregory

    2010-09-01

    Several factors have to be considered for implementing an accurate attenuation-correction (AC) method in a combined MR-PET scanner. In this work, some of these challenges were investigated, and an AC method based entirely on the MRI data obtained with a single dedicated sequence was developed and used for neurologic studies performed with the MR-PET human brain scanner prototype. The focus was on the problem of bone-air segmentation, selection of the linear attenuation coefficient for bone, and positioning of the radiofrequency coil. The impact of these factors on PET data quantification was studied in simulations and experimental measurements performed on the combined MR-PET scanner. A novel dual-echo ultrashort echo time (DUTE) MRI sequence was proposed for head imaging. Simultaneous MR-PET data were acquired, and the PET images reconstructed using the proposed DUTE MRI-based AC method were compared with the PET images that had been reconstructed using a CT-based AC method. Our data suggest that incorrectly accounting for the bone tissue attenuation can lead to large underestimations (>20%) of the radiotracer concentration in the cortex. Assigning a linear attenuation coefficient of 0.143 or 0.151 cm(-1) to bone tissue appears to give the best trade-off between bias and variability in the resulting images. Not identifying the internal air cavities introduces large overestimations (>20%) in adjacent structures. On the basis of these results, the segmented CT AC method was established as the silver standard for the segmented MRI-based AC method. For an integrated MR-PET scanner, in particular, ignoring the radiofrequency coil attenuation can cause large underestimations (i.e., PET field of view has to be accurately known. High-quality bone-air segmentation can be performed using the DUTE data. The PET images obtained using the DUTE MRI- and CT-based AC methods compare favorably in most of

  2. A brief history of choline

    Science.gov (United States)

    Zeisel, Steven H.

    2015-01-01

    In 1850, Theodore Gobley, working in Paris, described a substance “lecithine”, which he named after the Greek “lekithos” for egg yolk. Adolph Strecker noted in 1862 that when lecithin from bile was heated, it generated a new nitrogenous chemical that he named “choline”. Three years later, Oscar Liebreich identified a new substance, “neurine”, in the brain. After a period of confusion, neurine and choline were found to be the same molecule, and the name choline was adapted. Lecithin was eventually characterized chemically as being phosphatidylcholine. In 1954, Eugene Kennedy described the cytidine 5-dihphosphocholine pathway by which choline is incorporated into phosphatidylcholine. A second route, the phosphatidylethanolamine-N-methyltransferase pathway, was identified by Jon Bremer and David Greenberg in 1960. The role of choline as part of the neurotransmitter acetylcholine was established by Otto Loewi and Henry Dale. Working in the 1930s at the University of Toronto, Charles Best showed that choline prevented fatty liver in dogs and rats. The importance of choline as an essential nutrient for human health was determined in the 1990s through controlled feeding studies in humans. Recently, an understanding of the role of genetic variation in setting the dietary requirement for choline in people is being unraveled. PMID:23183298

  3. PET/CT with (18)F-choline after radical prostatectomy in patients with PSA ≤2 ng/ml. Can PSA velocity and PSA doubling time help in patient selection?

    Science.gov (United States)

    Chiaravalloti, Agostino; Di Biagio, Daniele; Tavolozza, Mario; Calabria, Ferdinando; Schillaci, Orazio

    2016-07-01

    To investigate the performance of (18)F-fluorocholine ((18)F-FCH) PET/CT in relation to the prostate-specific antigen (PSA) kinetic indexes, PSA doubling time (PSAdt) and PSA velocity (PSAve), in detecting recurrent prostate cancer (PC) in a selected population of patients treated with radical prostatectomy and with PSA ≤2 ng/ml. The study group comprised 79 patients (mean age 70 ± 7 years, range 58 - 77 years) who had been treated with radical surgery 30 to 90 months previously and with biochemical failure (defined as a measurable serum PSA level) who were evaluated with (18)F-FCH PET/CT. In order to establish the optimal threshold for PSAdt and PSAve, the diagnostic performance of PSA, PSAdt and PSAve were compared by receiver operating characteristic analysis. In the population examined, PSA (mean ± SD) was 1.37 ± 0.44 ng/ml (range 0.21 - 2 ng/ml) before PET/CT examination, PSAdt was 10.04 ± 16.67 months and PSAve was 2.75 ± 3.11 ng/ml per year. (18)F-FCH PET/CT was positive in 44 patients (55 %). PSAve and PSAdt were significantly different between patients with a positive and a negative (18)F-FCH PET/CT scan. Thresholds of 6 months for PSAdt and 1 ng/ml per year for PSAve were selected. For PSAdt ≤6 months the detection rate (DR) was 65 %, and for PSAve >1 ng/ml per year the DR was 67 %. PSA values were not significantly different between patients with a positive and a negative PET/CT scan. The results of our study suggest that (18)F-FCH PET/CT could be considered for the evaluation of patients with biochemical recurrence of PC and with low PSA levels. Fast PSA kinetics could be useful in the selection of these patients.

  4. Simultaneous PET/MRI with 13C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification

    DEFF Research Database (Denmark)

    Hansen, Adam E.; Andersen, Flemming L.; Henriksen, Sarah T.

    2016-01-01

    Background: Integrated PET/MRI with hyperpolarized 13C magnetic resonance spectroscopic imaging (13C-MRSI) offers simultaneous, dual-modality metabolic imaging. A prerequisite for the use of simultaneous imaging is the absence of interference between the two modalities. This has been documented...... for a clinical whole-body system using simultaneous 1 H-MRI and PET but never for 13C-MRSI and PET. Here, the feasibility of simultaneous PET and 13C-MRSI as well as hyperpolarized 13C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Methods: Combined PET and 13C......-MRSI phantoms including a NEMA [18F]-FDG phantom, 13C-acetate and 13C-urea sources, and hyperpolarized 13C-pyruvate were imaged repeatedly with PET and/or 13C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET...

  5. MR-1S Interacts with PET100 and PET117 in Module-Based Assembly of Human Cytochrome c Oxidase.

    Science.gov (United States)

    Vidoni, Sara; Harbour, Michael E; Guerrero-Castillo, Sergio; Signes, Alba; Ding, Shujing; Fearnley, Ian M; Taylor, Robert W; Tiranti, Valeria; Arnold, Susanne; Fernandez-Vizarra, Erika; Zeviani, Massimo

    2017-02-14

    The biogenesis of human cytochrome c oxidase (COX) is an intricate process in which three mitochondrial DNA (mtDNA)-encoded core subunits are assembled in a coordinated way with at least 11 nucleus-encoded subunits. Many chaperones shared between yeast and humans are involved in COX assembly. Here, we have used a MT-CO3 mutant cybrid cell line to define the composition of assembly intermediates and identify new human COX assembly factors. Quantitative mass spectrometry analysis led us to modify the assembly model from a sequential pathway to a module-based process. Each module contains one of the three core subunits, together with different ancillary components, including HIGD1A. By the same analysis, we identified the short isoform of the myofibrillogenesis regulator 1 (MR-1S) as a new COX assembly factor, which works with the highly conserved PET100 and PET117 chaperones to assist COX biogenesis in higher eukaryotes. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Photophysical studies of PET based acridinedione dyes with globular protein: Bovine serum albumin

    International Nuclear Information System (INIS)

    Rajendran, Kumaran; Perumal, Ramamurthy

    2010-01-01

    Interaction of acridinedione dyes with model transport proteins, bovine serum albumin (BSA) in aqueous solution were investigated by fluorescence spectral studies. A fluorescence enhancement was observed on the addition of BSA to photoinduced electron transfer (PET) based acridinedione dyes, which posses C 6 H 4 (p-OCH 3 ) in the 9th position of the basic acridinedione ring. On the contrary, the addition of BSA to non-PET based acridinedione dyes with methyl or phenyl substitution in the 9th position does not result in any fluorescence enhancement. The enhancement in the fluorescence intensity is attributed to the suppression of PET process through space between -OCH 3 group and the acridinedione moiety is elucidated by steady state fluorescence measurements. The fluorescence anisotropy value (r) of 0.40 reveals that the motion of the dye molecule is highly constrained and is largely confined to the rigid microenvironment of the protein molecule. The binding constant (K) was found to be in the order of 6.0x10 3 [M] -1 , which implies the existence of hydrophobic interaction between the PET based dye and BSA. Time resolved fluorescence lifetime measurements reveal that the PET based acridinedione dye preferably binds in the hydrophobic interior of BSA.

  7. PET image reconstruction with rotationally symmetric polygonal pixel grid based highly compressible system matrix

    International Nuclear Information System (INIS)

    Yu Yunhan; Xia Yan; Liu Yaqiang; Wang Shi; Ma Tianyu; Chen Jing; Hong Baoyu

    2013-01-01

    To achieve a maximum compression of system matrix in positron emission tomography (PET) image reconstruction, we proposed a polygonal image pixel division strategy in accordance with rotationally symmetric PET geometry. Geometrical definition and indexing rule for polygonal pixels were established. Image conversion from polygonal pixel structure to conventional rectangular pixel structure was implemented using a conversion matrix. A set of test images were analytically defined in polygonal pixel structure, converted to conventional rectangular pixel based images, and correctly displayed which verified the correctness of the image definition, conversion description and conversion of polygonal pixel structure. A compressed system matrix for PET image recon was generated by tap model and tested by forward-projecting three different distributions of radioactive sources to the sinogram domain and comparing them with theoretical predictions. On a practical small animal PET scanner, a compress ratio of 12.6:1 of the system matrix size was achieved with the polygonal pixel structure, comparing with the conventional rectangular pixel based tap-mode one. OS-EM iterative image reconstruction algorithms with the polygonal and conventional Cartesian pixel grid were developed. A hot rod phantom was detected and reconstructed based on these two grids with reasonable time cost. Image resolution of reconstructed images was both 1.35 mm. We conclude that it is feasible to reconstruct and display images in a polygonal image pixel structure based on a compressed system matrix in PET image reconstruction. (authors)

  8. Simultaneous PET/MRI with (13)C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification.

    Science.gov (United States)

    Hansen, Adam E; Andersen, Flemming L; Henriksen, Sarah T; Vignaud, Alexandre; Ardenkjaer-Larsen, Jan H; Højgaard, Liselotte; Kjaer, Andreas; Klausen, Thomas L

    2016-12-01

    Integrated PET/MRI with hyperpolarized (13)C magnetic resonance spectroscopic imaging ((13)C-MRSI) offers simultaneous, dual-modality metabolic imaging. A prerequisite for the use of simultaneous imaging is the absence of interference between the two modalities. This has been documented for a clinical whole-body system using simultaneous (1)H-MRI and PET but never for (13)C-MRSI and PET. Here, the feasibility of simultaneous PET and (13)C-MRSI as well as hyperpolarized (13)C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Combined PET and (13)C-MRSI phantoms including a NEMA [(18)F]-FDG phantom, (13)C-acetate and (13)C-urea sources, and hyperpolarized (13)C-pyruvate were imaged repeatedly with PET and/or (13)C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET trues; and (13)C-MRSI signal-to-noise ratio (SNR) for urea and acetate phantoms. Differences between measurement conditions were evaluated using t tests. PET and (13)C-MRSI data acquisition could be performed simultaneously without any discernible artifacts. The average difference in PET activity between acquisitions with and without simultaneous (13)C-MRSI was 0.83 (largest sphere) and -0.76 % (background). The average difference in net trues was -0.01 %. The average difference in (13)C-MRSI SNR between acquisitions with and without simultaneous PET ranged from -2.28 to 1.21 % for all phantoms and measurement conditions. No differences were significant. The system was capable of (13)C-MRSI of hyperpolarized (13)C-pyruvate. Simultaneous PET and (13)C-MRSI in an integrated whole-body PET/MRI hybrid scanner is feasible. Phantom experiments showed that possible interference effects introduced by acquiring data from the two modalities simultaneously are small and non-significant. Further experiments can now investigate the benefits of simultaneous PET and

  9. A novel digestion method based on a choline chloride–oxalic acid deep eutectic solvent for determining Cu, Fe, and Zn in fish samples

    Energy Technology Data Exchange (ETDEWEB)

    Habibi, Emadaldin [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Ghanemi, Kamal, E-mail: Kamal.ghanemi@kmsu.ac.ir [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Marine Science Research Institute, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of); Fallah-Mehrjardi, Mehdi [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Marine Science Research Institute, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of); Dadolahi-Sohrab, Ali [Department of Marine Environment, Faculty of marine natural resources, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of)

    2013-01-31

    Highlights: ► A novel digestion method: lack of concentrated acids or oxidizing reagents. ► First report of using choline chloride–oxalic acid (ChCl–Ox) for digestion. ► Complete dissolution of biological samples in ChCl–Ox for solubilization metals. ► Extraction recoveries greater than 95%: validated by the fish protein CRM. ► Successfully applied in different fish tissues (Muscle, Liver, and Gills). -- Abstract: A novel and efficient digestion method based on choline chloride–oxalic acid (ChCl–Ox) deep eutectic solvent (DES) was developed for flame atomic absorption spectrometry (FAAS) determination of Cu, Zn, and Fe in biological fish samples. Key parameters that influence analyte recovery were investigated and optimized, using the fish protein certified reference material (CRM, DORM-3) throughout the procedure. In this method, 100 mg of the sample was dissolved in ChCl–Ox (1:2, molar ratio) at 100 °C for 45 min. Then, 5.0 mL HNO{sub 3} (1.0 M) was added. After centrifugation, the supernatant solution was filtered, diluted to a known volume, and analyzed by FAAS. Under optimized conditions, an excellent agreement between the obtained results and the certified values was observed, using Student's t-test (P = 0.05); the extraction recovery of the all elements was greater than 95.3%. The proposed method was successfully applied to the determination of analytes in different tissues (muscle, liver, and gills) having a broad concentration range in a marine fish sample. The reproducibility of the method was validated by analyzing all samples by our method in a different laboratory, using inductively coupled plasma optical emission spectrometry (ICP-OES). For comparison, a conventional acid digestion (CAD) method was also used for the determination of analytes in all studied samples. The simplicity of the proposed experimental procedure, high extraction efficiency, short analysis time, lack of concentrated acids and oxidizing agents, and the

  10. A novel digestion method based on a choline chloride–oxalic acid deep eutectic solvent for determining Cu, Fe, and Zn in fish samples

    International Nuclear Information System (INIS)

    Habibi, Emadaldin; Ghanemi, Kamal; Fallah-Mehrjardi, Mehdi; Dadolahi-Sohrab, Ali

    2013-01-01

    Highlights: ► A novel digestion method: lack of concentrated acids or oxidizing reagents. ► First report of using choline chloride–oxalic acid (ChCl–Ox) for digestion. ► Complete dissolution of biological samples in ChCl–Ox for solubilization metals. ► Extraction recoveries greater than 95%: validated by the fish protein CRM. ► Successfully applied in different fish tissues (Muscle, Liver, and Gills). -- Abstract: A novel and efficient digestion method based on choline chloride–oxalic acid (ChCl–Ox) deep eutectic solvent (DES) was developed for flame atomic absorption spectrometry (FAAS) determination of Cu, Zn, and Fe in biological fish samples. Key parameters that influence analyte recovery were investigated and optimized, using the fish protein certified reference material (CRM, DORM-3) throughout the procedure. In this method, 100 mg of the sample was dissolved in ChCl–Ox (1:2, molar ratio) at 100 °C for 45 min. Then, 5.0 mL HNO 3 (1.0 M) was added. After centrifugation, the supernatant solution was filtered, diluted to a known volume, and analyzed by FAAS. Under optimized conditions, an excellent agreement between the obtained results and the certified values was observed, using Student's t-test (P = 0.05); the extraction recovery of the all elements was greater than 95.3%. The proposed method was successfully applied to the determination of analytes in different tissues (muscle, liver, and gills) having a broad concentration range in a marine fish sample. The reproducibility of the method was validated by analyzing all samples by our method in a different laboratory, using inductively coupled plasma optical emission spectrometry (ICP-OES). For comparison, a conventional acid digestion (CAD) method was also used for the determination of analytes in all studied samples. The simplicity of the proposed experimental procedure, high extraction efficiency, short analysis time, lack of concentrated acids and oxidizing agents, and the use of

  11. Model-Based Normalization of a Fractional-Crystal Collimator for Small-Animal PET Imaging.

    Science.gov (United States)

    Li, Yusheng; Matej, Samuel; Karp, Joel S; Metzler, Scott D

    2017-05-01

    Previously, we proposed to use a coincidence collimator to achieve fractional-crystal resolution in PET imaging. We have designed and fabricated a collimator prototype for a small-animal PET scanner, A-PET. To compensate for imperfections in the fabricated collimator prototype, collimator normalization, as well as scanner normalization, is required to reconstruct quantitative and artifact-free images. In this study, we develop a normalization method for the collimator prototype based on the A-PET normalization using a uniform cylinder phantom. We performed data acquisition without the collimator for scanner normalization first, and then with the collimator from eight different rotation views for collimator normalization. After a reconstruction without correction, we extracted the cylinder parameters from which we generated expected emission sinograms. Single scatter simulation was used to generate the scattered sinograms. We used the least-squares method to generate the normalization coefficient for each LOR based on measured, expected and scattered sinograms. The scanner and collimator normalization coefficients were factorized by performing two normalizations separately. The normalization methods were also verified using experimental data acquired from A-PET with and without the collimator. In summary, we developed a model-base collimator normalization that can significantly reduce variance and produce collimator normalization with adequate statistical quality within feasible scan time.

  12. Composites based on PET and red mud residues as catalyst for organic removal from water

    Energy Technology Data Exchange (ETDEWEB)

    Bento, Natálya I.; Santos, Patrícia S.C. [Science and Technology Institute, Federal University of Alfenas, Rodovia José Aurélio Vilela, 11999, BR 267, Km 533, CEP 37715-400 Poços de Caldas, MG (Brazil); Souza, Talita E. de; Oliveira, Luiz C.A. [Department of Chemistry, Federal University of Minas Gerais, UFMG, Av. Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG (Brazil); Castro, Cínthia S., E-mail: cinthia.soares.castro@gmail.com [Science and Technology Institute, Federal University of Alfenas, Rodovia José Aurélio Vilela, 11999, BR 267, Km 533, CEP 37715-400 Poços de Caldas, MG (Brazil)

    2016-08-15

    Highlights: • Composite based on carbon/iron oxide from PET and red mud wastes for organic contaminants oxidation. • Composites are mainly composed of hematite and a carbon matrix from PET decomposition. • RM/PET-15 presents the highest methylene blue (MB) removal from water, by combined adsorption and oxidation processes. • The dye oxidation was confirmed by ESI-MS studies. • The RM/PET catalysts can be reused for at least four batch runs. - Abstract: In this study, we obtained a composite based on carbon/iron oxide from red mud and PET (poly(ethylene terephthalate)) wastes by mechanical mixture (10, 15 and 20 wt.% of PET powder/red mud) followed by a controlled thermal treatment at 400 °C under air. XRD analyses revealed that the α-Fe{sub 2}O{sub 3} is the main phase formed from red mud. TPR analyses showed that the iron oxide present in the composites undergoes reduction at lower temperature to form Fe{sup 2+} species present in Fe{sub 3}O{sub 4}, indicating that the iron oxide in the composite can exhibit greater reactivity in the catalytic processes compared to the original red mud. In fact, catalytic tests showed that the composites presented higher capacity to remove methylene blue dye (MB), presenting about 90% of removal after 24 h of reaction. The MB removal was also monitored by mass spectrometer with ionization via electrospray (ESI-MS), which demonstrated the occurrence of the oxidation process, showing the formation of MB oxidation products. The stability of the composites was confirmed after four reuse cycles. The results seem to indicate that PET carbon deposited over the iron oxide from red mud promotes adsorption of the contaminant allowing its contact with the iron atoms and their consequent reaction.

  13. A Choline Oxidase Amperometric Bioassay for the Detection of Mustard Agents Based on Screen-Printed Electrodes Modified with Prussian Blue Nanoparticles

    Directory of Open Access Journals (Sweden)

    Fabiana Arduini

    2015-02-01

    Full Text Available In this work a novel bioassay for mustard agent detection was proposed. The bioassay is based on the capability of these compounds to inhibit the enzyme choline oxidase. The enzymatic activity, which is correlated to the mustard agents, was electrochemically monitored measuring the enzymatic product, hydrogen peroxide, by means of a screen-printed electrode modified with Prussian Blue nanoparticles. Prussian Blue nanoparticles are able to electrocatalyse the hydrogen peroxide concentration reduction at low applied potential (−50 mV vs. Ag/AgCl, thus allowing the detection of the mustard agents with no electrochemical interferences. The suitability of this novel bioassay was tested with the nitrogen mustard simulant bis(2-chloroethylamine and the sulfur mustard simulants 2-chloroethyl ethyl sulfide and 2-chloroethyl phenyl sulfide. The bioassay proposed in this work allowed the detection of mustard agent simulants with good sensitivity and fast response, which are excellent premises for the development of a miniaturised sensor well suited for an alarm system in case of terrorist attacks.

  14. Direct Patlak Reconstruction From Dynamic PET Data Using the Kernel Method With MRI Information Based on Structural Similarity.

    Science.gov (United States)

    Gong, Kuang; Cheng-Liao, Jinxiu; Wang, Guobao; Chen, Kevin T; Catana, Ciprian; Qi, Jinyi

    2018-04-01

    Positron emission tomography (PET) is a functional imaging modality widely used in oncology, cardiology, and neuroscience. It is highly sensitive, but suffers from relatively poor spatial resolution, as compared with anatomical imaging modalities, such as magnetic resonance imaging (MRI). With the recent development of combined PET/MR systems, we can improve the PET image quality by incorporating MR information into image reconstruction. Previously, kernel learning has been successfully embedded into static and dynamic PET image reconstruction using either PET temporal or MRI information. Here, we combine both PET temporal and MRI information adaptively to improve the quality of direct Patlak reconstruction. We examined different approaches to combine the PET and MRI information in kernel learning to address the issue of potential mismatches between MRI and PET signals. Computer simulations and hybrid real-patient data acquired on a simultaneous PET/MR scanner were used to evaluate the proposed methods. Results show that the method that combines PET temporal information and MRI spatial information adaptively based on the structure similarity index has the best performance in terms of noise reduction and resolution improvement.

  15. Deep Learning MR Imaging-based Attenuation Correction for PET/MR Imaging.

    Science.gov (United States)

    Liu, Fang; Jang, Hyungseok; Kijowski, Richard; Bradshaw, Tyler; McMillan, Alan B

    2018-02-01

    Purpose To develop and evaluate the feasibility of deep learning approaches for magnetic resonance (MR) imaging-based attenuation correction (AC) (termed deep MRAC) in brain positron emission tomography (PET)/MR imaging. Materials and Methods A PET/MR imaging AC pipeline was built by using a deep learning approach to generate pseudo computed tomographic (CT) scans from MR images. A deep convolutional auto-encoder network was trained to identify air, bone, and soft tissue in volumetric head MR images coregistered to CT data for training. A set of 30 retrospective three-dimensional T1-weighted head images was used to train the model, which was then evaluated in 10 patients by comparing the generated pseudo CT scan to an acquired CT scan. A prospective study was carried out for utilizing simultaneous PET/MR imaging for five subjects by using the proposed approach. Analysis of covariance and paired-sample t tests were used for statistical analysis to compare PET reconstruction error with deep MRAC and two existing MR imaging-based AC approaches with CT-based AC. Results Deep MRAC provides an accurate pseudo CT scan with a mean Dice coefficient of 0.971 ± 0.005 for air, 0.936 ± 0.011 for soft tissue, and 0.803 ± 0.021 for bone. Furthermore, deep MRAC provides good PET results, with average errors of less than 1% in most brain regions. Significantly lower PET reconstruction errors were realized with deep MRAC (-0.7% ± 1.1) compared with Dixon-based soft-tissue and air segmentation (-5.8% ± 3.1) and anatomic CT-based template registration (-4.8% ± 2.2). Conclusion The authors developed an automated approach that allows generation of discrete-valued pseudo CT scans (soft tissue, bone, and air) from a single high-spatial-resolution diagnostic-quality three-dimensional MR image and evaluated it in brain PET/MR imaging. This deep learning approach for MR imaging-based AC provided reduced PET reconstruction error relative to a CT-based standard within the brain compared

  16. Development of a Si-PM-based high-resolution PET system for small animals

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Imaizumi, Masao; Watabe, Tadashi; Shimosegawa, Eku; Hatazawa, Jun; Watabe, Hiroshi; Kanai, Yasukazu

    2010-01-01

    A Geiger-mode avalanche photodiode (Si-PM) is a promising photodetector for PET, especially for use in a magnetic resonance imaging (MRI) system, because it has high gain and is less sensitive to a static magnetic field. We developed a Si-PM-based depth-of-interaction (DOI) PET system for small animals. Hamamatsu 4 x 4 Si-PM arrays (S11065-025P) were used for its detector blocks. Two types of LGSO scintillator of 0.75 mol% Ce (decay time: ∼45 ns; 1.1 mm x 1.2 mm x 5 mm) and 0.025 mol% Ce (decay time: ∼31 ns; 1.1 mm x 1.2 mm x 6 mm) were optically coupled in the DOI direction to form a DOI detector, arranged in a 11 x 9 matrix, and optically coupled to the Si-PM array. Pulse shape analysis was used for the DOI detection of these two types of LGSOs. Sixteen detector blocks were arranged in a 68 mm diameter ring to form the PET system. Spatial resolution was 1.6 mm FWHM and sensitivity was 0.6% at the center of the field of view. High-resolution mouse and rat images were successfully obtained using the PET system. We confirmed that the developed Si-PM-based PET system is promising for molecular imaging research.

  17. Regional MLEM reconstruction strategy for PET-based treatment verification in ion beam radiotherapy

    International Nuclear Information System (INIS)

    Gianoli, Chiara; Riboldi, Marco; Fattori, Giovanni; Baselli, Giuseppe; Baroni, Guido; Bauer, Julia; Debus, Jürgen; Parodi, Katia; De Bernardi, Elisabetta

    2014-01-01

    In ion beam radiotherapy, PET-based treatment verification provides a consistency check of the delivered treatment with respect to a simulation based on the treatment planning. In this work the region-based MLEM reconstruction algorithm is proposed as a new evaluation strategy in PET-based treatment verification. The comparative evaluation is based on reconstructed PET images in selected regions, which are automatically identified on the expected PET images according to homogeneity in activity values. The strategy was tested on numerical and physical phantoms, simulating mismatches between the planned and measured β + activity distributions. The region-based MLEM reconstruction was demonstrated to be robust against noise and the sensitivity of the strategy results were comparable to three voxel units, corresponding to 6 mm in numerical phantoms. The robustness of the region-based MLEM evaluation outperformed the voxel-based strategies. The potential of the proposed strategy was also retrospectively assessed on patient data and further clinical validation is envisioned. (paper)

  18. The MINDView brain PET detector, feasibility study based on SiPM arrays

    Energy Technology Data Exchange (ETDEWEB)

    González, Antonio J., E-mail: agonzalez@i3m.upv.es [Institute for Instrumentation in Molecular Imaging (I3M), 46022 Valencia (Spain); Majewski, Stan [Radiology Research, Department of Radiology, University of Virginia, VA 22903 (United States); Sánchez, Filomeno [Institute for Instrumentation in Molecular Imaging (I3M), 46022 Valencia (Spain); Aussenhofer, Sebastian [NORAS MRI products GmbH, Hochberg (Germany); Aguilar, Albert; Conde, Pablo; Hernández, Liczandro; Vidal, Luis F. [Institute for Instrumentation in Molecular Imaging (I3M), 46022 Valencia (Spain); Pani, Roberto; Bettiol, Marco; Fabbri, Andrea [Department of Molecular Medicine, Sapienza University of Rome (Italy); Bert, Julien; Visvikis, Dimitris [Université de Bretagne Occidentale, Brest (France); Jackson, Carl; Murphy, John; O’Neill, Kevin [SensL Technologies, Cork (Ireland); Benlloch, Jose M. [Institute for Instrumentation in Molecular Imaging (I3M), 46022 Valencia (Spain)

    2016-05-11

    The Multimodal Imaging of Neurological Disorders (MINDView) project aims to develop a dedicated brain Positron Emission Tomography (PET) scanner with sufficient resolution and sensitivity to visualize neurotransmitter pathways and their disruptions in mental disorders for diagnosis and follow-up treatment. The PET system should be compact and fully compatible with a Magnetic Resonance Imaging (MRI) device in order to allow its operation as a PET brain insert in a hybrid imaging setup with most MRI scanners. The proposed design will enable the currently-installed MRI base to be easily upgraded to PET/MRI systems. The current design for the PET insert consists of a 3-ring configuration with 20 modules per ring and an axial field of view of ~15 cm and a geometrical aperture of ~33 cm in diameter. When coupled to the new head Radio Frequency (RF) coil, the inner usable diameter of the complete PET-RF coil insert is reduced to 26 cm. Two scintillator configurations have been tested, namely a 3-layer staggered array of LYSO with 1.5 mm pixel size, with 35×35 elements (6 mm thickness each) and a black-painted monolithic LYSO block also covering about 50×50 mm{sup 2} active area with 20 mm thickness. Laboratory test results associated with the current MINDView PET module concept are presented in terms of key parameters' optimization, such as spatial and energy resolution, sensitivity and Depth of Interaction (DOI) capability. It was possible to resolve all pixel elements from the three scintillator layers with energy resolutions as good as 10%. The monolithic scintillator showed average detector resolutions varying from 3.5 mm in the entrance layer to better than 1.5 mm near the photosensor, with average energy resolutions of about 17%.

  19. Design and implementation of a web-based PET-CT reporting assessment and e-portfolio tool

    International Nuclear Information System (INIS)

    Subesinghe, M.; Goldstone, A.R.; Patel, C.N.; Chowdhury, F.U.; Scarsbrook, A.F.

    2015-01-01

    Highlights: • We describe a simple internet-based reporting tool to enhance PET-CT training. • Automatically created competency based metrics are valuable in monitoring progress. • This tool provides robust evidence of competency in PET-CT reporting

  20. Dose prescription and treatment planning based on FMISO-PET hypoxia

    International Nuclear Information System (INIS)

    Toma-Dasu, Iuliana; Antonovic, Laura; Uhrdin, Johan; Dasu, Alexandru; Nuyts, Sandra; Dirix, Piet; Haustermans, Karin; Brahme, Anders

    2012-01-01

    Purpose. The study presents the implementation of a novel method for incorporating hypoxia information from PET-CT imaging into treatment planning and estimates the efficiency of various optimization approaches. Its focuses on the feasibility of optimizing treatment plans based on the non-linear conversion of PET hypoxia images into radiosensitivity maps from the uptake properties of the tracers used. Material and methods. PET hypoxia images of seven head-and-neck cancer patients were used to determine optimal dose distributions needed to counteract the radiation resistance associated with tumor hypoxia assuming various scenarios regarding the evolution of the hypoxic compartment during the treatment. A research planning system for advanced studies has been used to optimize IMRT plans based on hypoxia information from patient PET images. These resulting plans were compared in terms of target coverage for the same fulfilled constraints regarding the organs at risk. Results. The results of a planning study indicated the clinical feasibility of the proposed method for treatment planning based on PET hypoxia. Antihypoxic strategies would lead to small improvements in all the patients, but higher effects are expected for the fraction of patients with hypoxic tumors. For these, individualization of the treatment based on hypoxia PET imaging could lead to improved treatment outcome while creating the premises for limiting the irradiation of the surrounding normal tissues. Conclusions. The proposed approach offers the possibility of improved treatment results as it takes into consideration the heterogeneity and the dynamics of the hypoxic regions. It also provides early identification of the clinical cases that might benefit from dose escalation as well as the cases that could benefit from other counter-hypoxic measures

  1. Separation and recycling of cotton from cotton/PET blends by depolymerization of PET catalyzed by bases and ionic liquids

    NARCIS (Netherlands)

    Bouwhuis, G.H. (Gerrit); Brinks, G.J. (Ger); Groeneveld, R.A.J. (Richard); Oelerich, J. (Jens)

    2014-01-01

    The recycling of post consumer cotton textile waste is highly requested, due to the high environmental impact of cotton production. Often cotton is mixed in blends with polyethylene terephthalate (PET). For the generation of high value products from recycled cotton, it essential that PET is

  2. A statistical method for lung tumor segmentation uncertainty in PET images based on user inference.

    Science.gov (United States)

    Zheng, Chaojie; Wang, Xiuying; Feng, Dagan

    2015-01-01

    PET has been widely accepted as an effective imaging modality for lung tumor diagnosis and treatment. However, standard criteria for delineating tumor boundary from PET are yet to develop largely due to relatively low quality of PET images, uncertain tumor boundary definition, and variety of tumor characteristics. In this paper, we propose a statistical solution to segmentation uncertainty on the basis of user inference. We firstly define the uncertainty segmentation band on the basis of segmentation probability map constructed from Random Walks (RW) algorithm; and then based on the extracted features of the user inference, we use Principle Component Analysis (PCA) to formulate the statistical model for labeling the uncertainty band. We validated our method on 10 lung PET-CT phantom studies from the public RIDER collections [1] and 16 clinical PET studies where tumors were manually delineated by two experienced radiologists. The methods were validated using Dice similarity coefficient (DSC) to measure the spatial volume overlap. Our method achieved an average DSC of 0.878 ± 0.078 on phantom studies and 0.835 ± 0.039 on clinical studies.

  3. Deep-learning-based classification of FDG-PET data for Alzheimer's disease categories

    Science.gov (United States)

    Singh, Shibani; Srivastava, Anant; Mi, Liang; Caselli, Richard J.; Chen, Kewei; Goradia, Dhruman; Reiman, Eric M.; Wang, Yalin

    2017-11-01

    Fluorodeoxyglucose (FDG) positron emission tomography (PET) measures the decline in the regional cerebral metabolic rate for glucose, offering a reliable metabolic biomarker even on presymptomatic Alzheimer's disease (AD) patients. PET scans provide functional information that is unique and unavailable using other types of imaging. However, the computational efficacy of FDG-PET data alone, for the classification of various Alzheimers Diagnostic categories, has not been well studied. This motivates us to correctly discriminate various AD Diagnostic categories using FDG-PET data. Deep learning has improved state-of-the-art classification accuracies in the areas of speech, signal, image, video, text mining and recognition. We propose novel methods that involve probabilistic principal component analysis on max-pooled data and mean-pooled data for dimensionality reduction, and multilayer feed forward neural network which performs binary classification. Our experimental dataset consists of baseline data of subjects including 186 cognitively unimpaired (CU) subjects, 336 mild cognitive impairment (MCI) subjects with 158 Late MCI and 178 Early MCI, and 146 AD patients from Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. We measured F1-measure, precision, recall, negative and positive predictive values with a 10-fold cross validation scheme. Our results indicate that our designed classifiers achieve competitive results while max pooling achieves better classification performance compared to mean-pooled features. Our deep model based research may advance FDG-PET analysis by demonstrating their potential as an effective imaging biomarker of AD.

  4. PET/MR brain imaging: evaluation of clinical UTE-based attenuation correction

    International Nuclear Information System (INIS)

    Aasheim, Lars Birger; Karlberg, Anna; Goa, Paal Erik; Haaberg, Asta; Soerhaug, Sveinung; Fagerli, Unn-Merete; Eikenes, Live

    2015-01-01

    One of the greatest challenges in PET/MR imaging is that of accurate MR-based attenuation correction (AC) of the acquired PET data, which must be solved if the PET/MR modality is to reach its full potential. The aim of this study was to investigate the performance of Siemens' most recent version (VB20P) of MR-based AC of head PET data, by comparing it to CT-based AC. Methods: 18 F-FDG PET data from seven lymphoma and twelve lung cancer patients examined with a Biograph mMR PET/MR system were reconstructed with both CT-based and MR-based AC, avoiding sources of error arising when comparing PET data from different systems. The resulting images were compared quantitatively by measuring changes in mean SUV in ten different brain regions in both hemispheres, as well as the brainstem. In addition, the attenuation maps (μ maps) were compared regarding volume and localization of cranial bone. The UTE μ maps clearly overestimate the amount of bone in the neck, while slightly underestimating the amount of bone in the cranium, and the localization of bone in the cranial region also differ from the CT μ maps. In air/tissue interfaces in the sinuses and ears, the MRAC method struggles to correctly classify the different tissues. The misclassification of tissue is most likely caused by a combination of artefacts and the insufficiency of the UTE method to accurately separate bone. Quantitatively, this results in a combination of overestimation (0.5-3.6 %) and underestimation (2.7-5.2 %) of PET activity throughout the brain, depending on the proximity to the inaccurate regions. Our results indicate that the performance of the UTE method as implemented in VB20P is close to the theoretical maximum of such an MRAC method in the brain, while it does not perform satisfactorily in the neck or face/nasal area. Further improvement of the UTE MRAC or other available methods for more accurate segmentation of bone should be incorporated. (orig.)

  5. A small animal PET based on GAPDs and charge signal transmission approach for hybrid PET-MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jihoon; Choi, Yong; Hong, Key Jo; Hu, Wei; Jung, Jin Ho; Huh, Yoonsuk [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Kim, Byung-Tae, E-mail: ychoi.image@gmail.com [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of)

    2011-08-15

    Positron emission tomography (PET) employing Geiger-mode avalanche photodiodes (GAPDs) and charge signal transmission approach was developed for small animal imaging. Animal PET contained 16 LYSO and GAPD detector modules that were arranged in a 70 mm diameter ring with an axial field of view of 13 mm. The GAPDs charge output signals were transmitted to a preamplifier located remotely using 300 cm flexible flat cables. The position decoder circuits (PDCs) were used to multiplex the PET signals from 256 to 4 channels. The outputs of the PDCs were digitized and further-processed in the data acquisition unit. The cross-compatibilities of the PET detectors and MRI were assessed outside and inside the MRI. Experimental studies of the developed full ring PET were performed to examine the spatial resolution and sensitivity. Phantom and mouse images were acquired to examine the imaging performance. The mean energy and time resolution of the PET detector were 17.6% and 1.5 ns, respectively. No obvious degradation on PET and MRI was observed during simultaneous PET-MRI data acquisition. The measured spatial resolution and sensitivity at the CFOV were 2.8 mm and 0.7%, respectively. In addition, a 3 mm diameter line source was clearly resolved in the hot-sphere phantom images. The reconstructed transaxial PET images of the mouse brain and tumor displaying the glucose metabolism patterns were imaged well. These results demonstrate GAPD and the charge signal transmission approach can allow the development of high performance small animal PET with improved MR compatibility.

  6. Preparation and characterization of polymer blends based on recycled PET and polyester derived by terephthalic acid

    International Nuclear Information System (INIS)

    Ohara, L.; Miranda, C.S.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M.

    2010-01-01

    Environmentally friendly materials, made from industrial waste, are being increasingly used as a solution to the growing amount of waste generated by society, but also as a cheaper alternative to replace conventional materials for use in construction. In this work were investigated the properties of polymer blends based on recycled PET and a polyester derived from terephthalic acid and glycerin, a co-product of biodiesel. The samples were characterized by XRD, TGA, DSC, FTIR and SEM. The polyester synthesized showed a degradation event near 300 deg C. The blends with higher ratio of PET showed thermal behavior similar to pure PET. The X-ray diffraction showed that the polymer blends are semicrystalline materials. The micrographs presents the presence of a smooth surface, indicating the possibility of miscibility between the arrays. Therefore, the blending makes possible the fabrication of low-cost materials with applications in several areas. (author)

  7. PET-CT and PET-MRI of the prostate. From {sup 18}F-FDG to {sup 68}Ga-PSMA; PET-CT/-MRT der Prostata. Von {sup 18}F-FDG zu {sup 68}Ga-PSMA

    Energy Technology Data Exchange (ETDEWEB)

    Knorr, K.; Eiber, M.; Scheidhauer, K. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Maurer, T. [Technische Universitaet Muenchen, Urologische Klinik und Poliklinik, Klinikum rechts der Isar, Muenchen (Germany); Wester, H.J. [Technische Universitaet Muenchen, Pharmazeutische Radiochemie, Garching (Germany)

    2017-08-15

    In the last few years nuclear medical diagnostics have experienced a unprecedented renaissance in the diagnostics of prostate cancer, due to the availability of hybrid imaging with positron emission tomography computed tomography (PET/CT), PET magnetic resonance imaging (PET/MRI) and single photon emission computed tomography (SPECT) CT as well as the development of prostate-specific radiopharmaceuticals. The use of fluorodeoxyglucose (FDG), which has been successfully implemented for many years in PET diagnostics, is only helpful in dedifferentiated tumors due to the biological characteristics of prostate cancer. New specific radiopharmaceuticals, such as choline-derivatives, which are incorporated into the prostate cancer cell and built into the cell membrane as well as the recently developed highly specific ligands for prostate-specific membrane antigen (PSMA) are revolutionizing prostate cancer imaging and (re-) staging. The {sup 68} Ga-labeled PSMA ligands for PET-CT and PET-MRI are highly specific tracers for primary diagnostics and detection of metastases of prostate carcinoma. In risk patients, which includes patients with intermediate and high-risk tumors, they have largely replaced choline-based PET-CT, especially in the case of very low PSA values <0.5 ng/ml in the diagnostics of recurrence. The use in the primary diagnostics as PET-MRI, also in combination with multiparametric MRI (mpMRI), is promising with respect to early diagnostics and image fusion-assisted biopsy as well as surgery and irradiation planning. (orig.) [German] Die nuklearmedizinische Diagnostik hat in den letzten Jahren bei der Bildgebung des Prostatakarzinoms eine rasante Entwicklung erlebt, sowohl aufgrund der verfuegbaren Hybridbildgebung mit der Positronenemissionstomographie(PET)-CT, PET-MRT sowie der Single-photon-emission-computed-tomography(SPECT)-CT als auch durch die Entwicklung prostataspezifischer Radiopharmaka. Die in der PET-Diagnostik seit Jahren erfolgreich eingesetzte

  8. FDG PET/CT in cancer: comparison of actual use with literature-based recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Henrik; Johansen, Allan; Hoeilund-Carlsen, Poul Flemming [Odense University Hospital, Department of Nuclear Medicine, Odense C (Denmark); Holdgaard, Paw Christian [Vejle Hospital, Department of Nuclear Medicine, Vejle (Denmark); Madsen, Poul Henning [Vejle Hospital, Department of Medicine, Vejle (Denmark); Knudsen, Lene Meldgaard [Odense University Hospital, Department of Haematological, Odense (Denmark); Gad, Dorte; Gravergaard, Anders Eggert [Odense University Hospital, Department of Plastic Surgery, Odense (Denmark); Rohde, Max; Godballe, Christian [Odense University Hospital, Department of ORL Head and Neck Surgery, Odense (Denmark); Engelmann, Bodil Elisabeth [Naestved Sygehus, Department of Clinical Physiology and Nuclear Medicine, Naestved (Denmark); Bech, Karsten [Aabenraa Sygehus, Organ Centre, Aabenraa (Denmark); Teilmann-Joergensen, Dorte [Aabenraa Sygehus, Department of Gynaecoligcal and Obstetrics, Aabenraa (Denmark); Mogensen, Ole [Odense University Hospital, Department of Gynaecoligcal and Obstetrics, Odense (Denmark); Karstoft, Jens [Odense University Hospital, Department of Radiology, Odense (Denmark); Johansen, Joergen [Odense University Hospital, Department of Oncology, Odense (Denmark); Christensen, Janne Buck [Odense University Hospital, Department of Quality and Research/HTA, Odense (Denmark); Collaboration: on behalf of the PET/CT Task Force of the Region of Southern Denmark

    2016-04-15

    The Region of Southern Denmark (RSD), covering 1.2 of Denmark's 5.6 million inhabitants, established a task force to (1) retrieve literature evidence for the clinical use of positron emission tomography (PET)/CT and provide consequent recommendations and further to (2) compare the actual use of PET/CT in the RSD with these recommendations. This article summarizes the results. A Work Group appointed a professional Subgroup which made Clinician Groups conduct literature reviews on six selected cancers responsible for 5,768 (62.6 %) of 9,213 PET/CT scans in the RSD in 2012. Rapid Evidence Assessment was applied, using the methodology of systematic reviews with predefined limitations to search PubMed, Embase and the Cochrane Library for articles published in English/Danish/Swedish/Norwegian since 2002. PICO questions were defined, data recorded and quality appraised and rated with regard to strength and evidence level. Consequent recommendations for applications of PET/CT were established. The actual use of PET/CT was compared with these, where grades A and B indicated ''established'' and ''useful'' and grades C and D ''potentially useful'' and ''non-recommendable'' indications, respectively. Of 11,729 citations, 1,729 were considered for review, and 204 were included. The evidence suggested usefulness of PET/CT in lung, lymphoma, melanoma, head and neck, and colorectal cancers, whereas evidence was sparse in gynaecological cancers. The agreement between actual use of PET/CT and literature-based recommendations was high in the first five mentioned cancers in that 96.2 % of scans were made for grade A or B indications versus only 22.2 % in gynaecological cancers. Evidence-based usefulness was reported in five of six selected cancers; evidence was sparse in the sixth, gynaecological cancers. Actual use of PET/CT agreed well with recommendations. (orig.)

  9. Evaluation of the choline status in mink fed different levels and sources of choline

    DEFF Research Database (Denmark)

    Hedemann, Mette Skou; Damgaard, Birthe Marie; Clausen, T.N.

    2012-01-01

    Choline is an essential nutrient but the daily need for choline in mink has never been determined. Two experiments were performed to evalutate the choline status in mink kits and full-grown mink fed different levels of choline. In the first experiment mink kits were fed a synthetic diet with chol...

  10. Evaluating radon loss from water during storage in standard PET, bio-based PET, and PLA bottles

    International Nuclear Information System (INIS)

    Lucchetti, Carlo; De Simone, Gabriele; Galli, Gianfranco; Tuccimei, Paola

    2016-01-01

    Polyethylene terephthalate (PET) and polylactic acid (PLA) bottles were tested to evaluate radon loss from water during 15 days of storage. PET bottles (lower surface/volume-ratio vials) lost 0.4–7.1% of initial radon, whereas PLA bottles lost 3.7% of it. PET bottles with volume of 0.5 L, lower surface/weight ratio, and hence higher thickness display proportionally reduced radon loss. Corrections for dissolved radium are needed during analyses. Formulas for calculating degassing efficiency and water interference on electrostatic collections are developed. - Highlights: • Radon loss from water during storage in polyethylene terephthalate (PET) and polylactic acid (PLA) bottles was evaluated. • Surface/volume ratio and thickness of plastic materials were studied. • A correction for dissolved radium concentration was applied to estimate gas loss. • Proper corrections for degassing efficiency of aerators were developed. • The interference of H 2 O on radon daughter electrostatic collection was quantified.

  11. Improved frame-based estimation of head motion in PET brain imaging

    International Nuclear Information System (INIS)

    Mukherjee, J. M.; Lindsay, C.; King, M. A.; Licho, R.; Mukherjee, A.; Olivier, P.; Shao, L.

    2016-01-01

    not susceptible to motion introduced between CT and PET acquisitions. Conclusions: The authors have shown that they can estimate motion for frames with time intervals as short as 5 s using nonattenuation corrected reconstructed FDG PET brain images. Intraframe motion in 60-s frames causes degradation of accuracy to about 2 mm based on the motion type.

  12. Improved frame-based estimation of head motion in PET brain imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, J. M., E-mail: joyeeta.mitra@umassmed.edu; Lindsay, C.; King, M. A.; Licho, R. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Mukherjee, A. [Aware, Inc., Bedford, Massachusetts 01730 (United States); Olivier, P. [Philips Medical Systems, Cleveland, Ohio 44143 (United States); Shao, L. [ViewRay, Oakwood Village, Ohio 44146 (United States)

    2016-05-15

    not susceptible to motion introduced between CT and PET acquisitions. Conclusions: The authors have shown that they can estimate motion for frames with time intervals as short as 5 s using nonattenuation corrected reconstructed FDG PET brain images. Intraframe motion in 60-s frames causes degradation of accuracy to about 2 mm based on the motion type.

  13. 21 CFR 582.5252 - Choline chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Choline chloride. 582.5252 Section 582.5252 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5252 Choline chloride. (a) Product. Choline chloride. (b) Conditions of use. This...

  14. Comparison between MRI-based attenuation correction methods for brain PET in dementia patients

    International Nuclear Information System (INIS)

    Cabello, Jorge; Lukas, Mathias; Pyka, Thomas; Nekolla, Stephan G.; Ziegler, Sibylle I.; Rota Kops, Elena; Shah, N. Jon; Ribeiro, Andre; Yakushev, Igor

    2016-01-01

    The combination of Positron Emission Tomography (PET) with magnetic resonance imaging (MRI) in hybrid PET/MRI scanners offers a number of advantages in investigating brain structure and function. A critical step of PET data reconstruction is attenuation correction (AC). Accounting for bone in attenuation maps (μ-map) was shown to be important in brain PET studies. While there are a number of MRI-based AC methods, no systematic comparison between them has been performed so far. The aim of this work was to study the different performance obtained by some of the recent methods presented in the literature. To perform such a comparison, we focused on [ 18 F]-Fluorodeoxyglucose-PET/MRI neurodegenerative dementing disorders, which are known to exhibit reduced levels of glucose metabolism in certain brain regions. Four novel methods were used to calculate μ-maps from MRI data of 15 patients with Alzheimer's dementia (AD). The methods cover two atlas-based methods, a segmentation method, and a hybrid template/segmentation method. Additionally, the Dixon-based and a UTE-based method, offered by a vendor, were included in the comparison. Performance was assessed at three levels: tissue identification accuracy in the μ-map, quantitative accuracy of reconstructed PET data in specific brain regions, and precision in diagnostic images at identifying hypometabolic areas. Quantitative regional errors of -20-10 % were obtained using the vendor's AC methods, whereas the novel methods produced errors in a margin of ±5 %. The obtained precision at identifying areas with abnormally low levels of glucose uptake, potentially regions affected by AD, were 62.9 and 79.5 % for the two vendor AC methods, the former ignoring bone and the latter including bone information. The precision increased to 87.5-93.3 % in average for the four new methods, exhibiting similar performances. We confirm that the AC methods based on the Dixon and UTE sequences provided by the vendor are inferior

  15. Comparison between MRI-based attenuation correction methods for brain PET in dementia patients

    Energy Technology Data Exchange (ETDEWEB)

    Cabello, Jorge; Lukas, Mathias; Pyka, Thomas; Nekolla, Stephan G.; Ziegler, Sibylle I. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Rota Kops, Elena; Shah, N. Jon [Forschungszentrum Juelich GmbH, Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Juelich (Germany); Ribeiro, Andre [Forschungszentrum Juelich GmbH, Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Juelich (Germany); Institute of Biophysics and Biomedical Engineering, Lisbon (Portugal); Yakushev, Igor [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Institute TUM Neuroimaging Center (TUM-NIC), Munich (Germany)

    2016-11-15

    The combination of Positron Emission Tomography (PET) with magnetic resonance imaging (MRI) in hybrid PET/MRI scanners offers a number of advantages in investigating brain structure and function. A critical step of PET data reconstruction is attenuation correction (AC). Accounting for bone in attenuation maps (μ-map) was shown to be important in brain PET studies. While there are a number of MRI-based AC methods, no systematic comparison between them has been performed so far. The aim of this work was to study the different performance obtained by some of the recent methods presented in the literature. To perform such a comparison, we focused on [{sup 18}F]-Fluorodeoxyglucose-PET/MRI neurodegenerative dementing disorders, which are known to exhibit reduced levels of glucose metabolism in certain brain regions. Four novel methods were used to calculate μ-maps from MRI data of 15 patients with Alzheimer's dementia (AD). The methods cover two atlas-based methods, a segmentation method, and a hybrid template/segmentation method. Additionally, the Dixon-based and a UTE-based method, offered by a vendor, were included in the comparison. Performance was assessed at three levels: tissue identification accuracy in the μ-map, quantitative accuracy of reconstructed PET data in specific brain regions, and precision in diagnostic images at identifying hypometabolic areas. Quantitative regional errors of -20-10 % were obtained using the vendor's AC methods, whereas the novel methods produced errors in a margin of ±5 %. The obtained precision at identifying areas with abnormally low levels of glucose uptake, potentially regions affected by AD, were 62.9 and 79.5 % for the two vendor AC methods, the former ignoring bone and the latter including bone information. The precision increased to 87.5-93.3 % in average for the four new methods, exhibiting similar performances. We confirm that the AC methods based on the Dixon and UTE sequences provided by the vendor are

  16. Time of flight measurements based on FPGA using a breast dedicated PET

    International Nuclear Information System (INIS)

    Aguilar, A; García-Olcina, R; Martos, J; Soret, J; Torres, J; Benlloch, J M; González, A J; Sánchez, F

    2014-01-01

    In this work the implementation of a Time-to-Digital Converter (TDC) using a Nutt delay line FPGA-based and applied on a Positron Emission Tomography (PET) device is going to be presented in order to check the system's suitability for Time of Flight (TOF) measurements. In recent years, FPGAs have shown great advantages for precise time measurements in PET. The architecture employed for these measurements is described in detail. The system developed was tested on a dedicated breast PET prototype, composed of LYSO crystals and Positive Sensitive Photomultipliers (PSPMTs). Two distinct experiments were carried out for this purpose. In the first test, system linearity was evaluated in order to calibrate the time measurements, providing a linearity error of less than 2% and an average time resolution of 1.4 ns FWHM. The second set of measurements tested system resolution, resulting in a FWHM as good as 1.35 ns. The results suggest that the coincidence window for the current PET can be reduced in order to minimize the random events and thus, achieve better image quality

  17. Time over threshold based multi-channel LuAG-APD PET detector

    International Nuclear Information System (INIS)

    Shimazoe, Kenji; Orita, Tadashi; Nakamura, Yasuaki; Takahashi, Hiroyuki

    2013-01-01

    To achieve efficient signal processing, several time-based positron emission tomography (PET) systems using a large number of granulated gamma-ray detectors have recently been proposed. In this work described here, a 144-channel Pr:LuAG avalanche photodiode (APD) PET detector that uses time over threshold (ToT) and pulse train methods was designed and fabricated. The detector is composed of 12×12 Pr:LuAG crystals, each of which produces a 2 mm×2 mm×10 mm pixel individually coupled to a 12×12 APD array, which in turn is connected pixel-by-pixel with one channel of a time over threshold based application-specific integrated circuit (ToT-ASIC) that was designed and fabricated using a 0.25 μm 3.3 V Taiwan Semiconductor Company complementary metal oxide semiconductor (TSMC CMOS) process. The ToT outputs are connected through a field-programmable gate array (FPGA) to a data acquisition (DAQ) system. Three front-end ASIC boards—each incorporating a ToT-ASIC chip, threshold control digital-to-analog converters (DACs), and connectors, and dissipating power at about 230 mW per board—are used to read from the 144-channel LuAG-APD detector. All three boards are connected through an FPGA board that is programmed to calibrate the individual thresholds of the ToT circuits to allow digital multiplexing to form an integrated PET module with a measured timing resolution of 4.2 ns. Images transmitted by this PET system can be successfully acquired through collimation masks. As a further implementation of this technology, an animal PET system consisting of eight gamma pixel modules forming a ring is planned

  18. Genetic Variation in Choline-Metabolizing Enzymes Alters Choline Metabolism in Young Women Consuming Choline Intakes Meeting Current Recommendations

    Directory of Open Access Journals (Sweden)

    Ariel B. Ganz

    2017-01-01

    Full Text Available Single nucleotide polymorphisms (SNPs in choline metabolizing genes are associated with disease risk and greater susceptibility to organ dysfunction under conditions of dietary choline restriction. However, the underlying metabolic signatures of these variants are not well characterized and it is unknown whether genotypic differences persist at recommended choline intakes. Thus, we sought to determine if common genetic risk factors alter choline dynamics in pregnant, lactating, and non-pregnant women consuming choline intakes meeting and exceeding current recommendations. Women (n = 75 consumed 480 or 930 mg choline/day (22% as a metabolic tracer, choline-d9 for 10–12 weeks in a controlled feeding study. Genotyping was performed for eight variant SNPs and genetic differences in metabolic flux and partitioning of plasma choline metabolites were evaluated using stable isotope methodology. CHKA rs10791957, CHDH rs9001, CHDH rs12676, PEMT rs4646343, PEMT rs7946, FMO3 rs2266782, SLC44A1 rs7873937, and SLC44A1 rs3199966 altered the use of choline as a methyl donor; CHDH rs9001 and BHMT rs3733890 altered the partitioning of dietary choline between betaine and phosphatidylcholine synthesis via the cytidine diphosphate (CDP-choline pathway; and CHKA rs10791957, CHDH rs12676, PEMT rs4646343, PEMT rs7946 and SLC44A1 rs7873937 altered the distribution of dietary choline between the CDP-choline and phosphatidylethanolamine N-methyltransferase (PEMT denovo pathway. Such metabolic differences may contribute to disease pathogenesis and prognosis over the long-term.

  19. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    International Nuclear Information System (INIS)

    Rota Kops, Elena; Herzog, Hans

    2013-01-01

    Aim: Attenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methods: An anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). Results: Error A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled

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

    Science.gov (United States)

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

    2017-04-01

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

  1. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    Science.gov (United States)

    Rota Kops, Elena; Herzog, Hans

    2013-02-01

    AimAttenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methodsAn anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). ResultsError A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled nasal

  2. MRI-Based Nonrigid Motion Correction in Simultaneous PET/MRI

    Science.gov (United States)

    Chun, Se Young; Reese, Timothy G.; Ouyang, Jinsong; Guerin, Bastien; Catana, Ciprian; Zhu, Xuping; Alpert, Nathaniel M.; El Fakhri, Georges

    2014-01-01

    Respiratory and cardiac motion is the most serious limitation to whole-body PET, resulting in spatial resolution close to 1 cm. Furthermore, motion-induced inconsistencies in the attenuation measurements often lead to significant artifacts in the reconstructed images. Gating can remove motion artifacts at the cost of increased noise. This paper presents an approach to respiratory motion correction using simultaneous PET/MRI to demonstrate initial results in phantoms, rabbits, and nonhuman primates and discusses the prospects for clinical application. Methods Studies with a deformable phantom, a free-breathing primate, and rabbits implanted with radioactive beads were performed with simultaneous PET/MRI. Motion fields were estimated from concurrently acquired tagged MR images using 2 B-spline nonrigid image registration methods and incorporated into a PET list-mode ordered-subsets expectation maximization algorithm. Using the measured motion fields to transform both the emission data and the attenuation data, we could use all the coincidence data to reconstruct any phase of the respiratory cycle. We compared the resulting SNR and the channelized Hotelling observer (CHO) detection signal-to-noise ratio (SNR) in the motion-corrected reconstruction with the results obtained from standard gating and uncorrected studies. Results Motion correction virtually eliminated motion blur without reducing SNR, yielding images with SNR comparable to those obtained by gating with 5–8 times longer acquisitions in all studies. The CHO study in dynamic phantoms demonstrated a significant improvement (166%–276%) in lesion detection SNR with MRI-based motion correction as compared with gating (P < 0.001). This improvement was 43%–92% for large motion compared with lesion detection without motion correction (P < 0.001). CHO SNR in the rabbit studies confirmed these results. Conclusion Tagged MRI motion correction in simultaneous PET/MRI significantly improves lesion detection

  3. Neuroprotective Actions of Dietary Choline

    Directory of Open Access Journals (Sweden)

    Jan Krzysztof Blusztajn

    2017-07-01

    Full Text Available Choline is an essential nutrient for humans. It is a precursor of membrane phospholipids (e.g., phosphatidylcholine (PC, the neurotransmitter acetylcholine, and via betaine, the methyl group donor S-adenosylmethionine. High choline intake during gestation and early postnatal development in rat and mouse models improves cognitive function in adulthood, prevents age-related memory decline, and protects the brain from the neuropathological changes associated with Alzheimer’s disease (AD, and neurological damage associated with epilepsy, fetal alcohol syndrome, and inherited conditions such as Down and Rett syndromes. These effects of choline are correlated with modifications in histone and DNA methylation in brain, and with alterations in the expression of genes that encode proteins important for learning and memory processing, suggesting a possible epigenomic mechanism of action. Dietary choline intake in the adult may also influence cognitive function via an effect on PC containing eicosapentaenoic and docosahexaenoic acids; polyunsaturated species of PC whose levels are reduced in brains from AD patients, and is associated with higher memory performance, and resistance to cognitive decline.

  4. Monte Carlo based performance assessment of different animal PET architectures using pixellated CZT detectors

    International Nuclear Information System (INIS)

    Visvikis, D.; Lefevre, T.; Lamare, F.; Kontaxakis, G.; Santos, A.; Darambara, D.

    2006-01-01

    The majority of present position emission tomography (PET) animal systems are based on the coupling of high-density scintillators and light detectors. A disadvantage of these detector configurations is the compromise between image resolution, sensitivity and energy resolution. In addition, current combined imaging devices are based on simply placing back-to-back and in axial alignment different apparatus without any significant level of software or hardware integration. The use of semiconductor CdZnTe (CZT) detectors is a promising alternative to scintillators for gamma-ray imaging systems. At the same time CZT detectors have the potential properties necessary for the construction of a truly integrated imaging device (PET/SPECT/CT). The aims of this study was to assess the performance of different small animal PET scanner architectures based on CZT pixellated detectors and compare their performance with that of state of the art existing PET animal scanners. Different scanner architectures were modelled using GATE (Geant4 Application for Tomographic Emission). Particular scanner design characteristics included an overall cylindrical scanner format of 8 and 24 cm in axial and transaxial field of view, respectively, and a temporal coincidence window of 8 ns. Different individual detector modules were investigated, considering pixel pitch down to 0.625 mm and detector thickness from 1 to 5 mm. Modified NEMA NU2-2001 protocols were used in order to simulate performance based on mouse, rat and monkey imaging conditions. These protocols allowed us to directly compare the performance of the proposed geometries with the latest generation of current small animal systems. Results attained demonstrate the potential for higher NECR with CZT based scanners in comparison to scintillator based animal systems

  5. Green synthesis of chromium-based metal-organic framework (Cr-MOF) from waste polyethylene terephthalate (PET) bottles for hydrogen storage applications

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2016-10-01

    Full Text Available It is of great economic value to produce high-value PET-based MOF materials by the veritable elimination of waste PET, and provide sufficient MOF materials for hydrogen storage applications. Consequently, this work demonstrates the use of waste PET...

  6. FDG-PET-based radiotherapy planning in lung cancer. Optimum breathing protocol and patient positioning - an intraindividual comparison; FDG-PET-basierte Bestrahlungsplanung von nicht kleinzelligen Bronchialkarzinomen. Optimales Atemprotokoll und Patientenpositionierung - ein intraindividueller Vergleich

    Energy Technology Data Exchange (ETDEWEB)

    Grgic, A.; Schaefer-Schuler, A.; Kirsch, C.M.; Hellwig, D. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Nuklearmedizin; Nestle, U. [Universitaetsklinikum Freiburg (Germany). Klinik fuer Strahlenheilkunde; Kremp, S. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    2008-12-15

    FDG-PET and PET / CT is increasingly used for radiotherapy (RT) planning in non-small-cell lung carcinoma (NSCLC). The planning process is often based on separately-acquired FDG-PET / CT and planning CT. We compared intraindividual differences between PET acquired in diagnostic and radiotherapy treatment position coregistered with planning CTs acquired using different breathing protocols. Sixteen patients with NSCLC underwent two PET acquisitions (diagnostic position-D-PET, radiotherapy position-RT-PET) and three planning-CT acquisitions (expiration-EXP, inspiration-INS, mid-breathhold-MID) on the same day. All scans were rigidly coregistered resulting in six fused datasets: D-INS, D-EXP, D-MID, RT-INS, RT-EXP and RT-MID. Fusion accuracy was assessed by three readers at eight anatomical landmarks: lung apices, aortic arch, heart, spine, sternum, carina, diaphragm and tumor using an alignment score ranging from 1 (no alignment) to 5 (exact alignment). RT-PET showed better alignment with any CT than D-PET (p < 0.001). With regard to breathing, RT-MID showed the best mean alignment score (3.7 {+-} 1.0) followed by RT-EXP (3.5 {+-} 0.9) and RT-INS (3.0 {+-} 0.8), all differences being significant (p < 0.001). Comparing the alignment scores with regard to anatomical landmarks, the largest deviations were found at diaphragm, heart and apices. Overall, there was a fair agreement (? = 0.48; p < 0.001) among the three readers. Significantly better fusion of PET and planning-CT can be reached with PET acquired in RT-position. The best intraindividual fusion results are obtained with the planning-CT performed during mid-breathhold. Our data justify the acquisition of a separate planning-PET in RT-treatment position if only a diagnostic PET-scan is available. (orig.)

  7. The development and preliminary testing of new boronated agents for BNCT based on PET derived data

    International Nuclear Information System (INIS)

    Nichols, T.; Kabalka, G.; Kahn, M.; Das, B.; Das, S.; Bao, W.; Miller, L.

    2000-01-01

    Positron emission tomography (PET) has been utilized at the University of Tennessee for evaluating a variety of tumors including glioblastoma multiforme (GBM) and metastatic malignant melanoma (MM). Studies have been carried out utilizing fluorine-18 labeled p-boronophenylalanine ( 18 F-BPA) and other unnatural amino acids. A comparison of PET studies obtained using 18 F-BPA and a carbon-11 labeled cyclobutane-based amino acid ( 11 C-ACBC) revealed that 11 C-ACBC localized effectively in GBM tumors. Based on these results, we have prepared a series of boronated, aminocyclobutanecarboxylic acids. Preliminary uptake and cell toxicity studies have been carried out and show that many of the agents are not toxic. In one instance, a biodistribution study carried out using nude mice implanted with a human glioblastoma tumor, the tumor to normal tissue uptake of boron exceeds that observed for BPA. (author)

  8. 3.5D dynamic PET image reconstruction incorporating kinetics-based clusters

    International Nuclear Information System (INIS)

    Lu Lijun; Chen Wufan; Karakatsanis, Nicolas A; Rahmim, Arman; Tang Jing

    2012-01-01

    Standard 3D dynamic positron emission tomographic (PET) imaging consists of independent image reconstructions of individual frames followed by application of appropriate kinetic model to the time activity curves at the voxel or region-of-interest (ROI). The emerging field of 4D PET reconstruction, by contrast, seeks to move beyond this scheme and incorporate information from multiple frames within the image reconstruction task. Here we propose a novel reconstruction framework aiming to enhance quantitative accuracy of parametric images via introduction of priors based on voxel kinetics, as generated via clustering of preliminary reconstructed dynamic images to define clustered neighborhoods of voxels with similar kinetics. This is then followed by straightforward maximum a posteriori (MAP) 3D PET reconstruction as applied to individual frames; and as such the method is labeled ‘3.5D’ image reconstruction. The use of cluster-based priors has the advantage of further enhancing quantitative performance in dynamic PET imaging, because: (a) there are typically more voxels in clusters than in conventional local neighborhoods, and (b) neighboring voxels with distinct kinetics are less likely to be clustered together. Using realistic simulated 11 C-raclopride dynamic PET data, the quantitative performance of the proposed method was investigated. Parametric distribution-volume (DV) and DV ratio (DVR) images were estimated from dynamic image reconstructions using (a) maximum-likelihood expectation maximization (MLEM), and MAP reconstructions using (b) the quadratic prior (QP-MAP), (c) the Green prior (GP-MAP) and (d, e) two proposed cluster-based priors (CP-U-MAP and CP-W-MAP), followed by graphical modeling, and were qualitatively and quantitatively compared for 11 ROIs. Overall, the proposed dynamic PET reconstruction methodology resulted in substantial visual as well as quantitative accuracy improvements (in terms of noise versus bias performance) for parametric DV

  9. Improving the Spatial Alignment in PET/CT Using Amplitude-Based Respiration-Gated PET and Respiration-Triggered CT

    NARCIS (Netherlands)

    Vos, C.S. van der; Grootjans, W.; Osborne, D.R.; Meeuwis, A.P.; Hamill, J.J.; Acuff, S.; Geus-Oei, L.F. de; Visser, E.P.

    2015-01-01

    Respiratory motion during PET can cause inaccuracies in the quantification of radiotracer uptake, which negatively affects PET-guided radiotherapy planning. Quantitative accuracy can be improved by respiratory gating. However, additional miscalculation of standardized uptake value (SUV) in PET

  10. Study of oxygen scavenging PET-based films activated by water

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana [Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II, 132 - 84084 Fisciano (Italy)

    2016-05-18

    In this work an active barrier system consisting of a thin and transparent film based on polyethylene terephthalate (PET) was studied. Dynamic oxygen absorption measurements were performed at different values of relative humidity and temperature, pointing out that humidity is a key factor in activating the oxidation of the polymer sample. Moreover, the thermal and optical properties of the films were investigated and a good correlation was found between the crystallinity increase and the consequent transparency reduction occurring after the oxygen absorption.

  11. Study of oxygen scavenging PET-based films activated by water

    Science.gov (United States)

    Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana

    2016-05-01

    In this work an active barrier system consisting of a thin and transparent film based on polyethylene terephthalate (PET) was studied. Dynamic oxygen absorption measurements were performed at different values of relative humidity and temperature, pointing out that humidity is a key factor in activating the oxidation of the polymer sample. Moreover, the thermal and optical properties of the films were investigated and a good correlation was found between the crystallinity increase and the consequent transparency reduction occurring after the oxygen absorption.

  12. Whole-body PET/MRI: The effect of bone attenuation during MR-based attenuation correction in oncology imaging

    DEFF Research Database (Denmark)

    Aznar, M.C.; Sersar, Rachida; Saabye, J.

    2014-01-01

    patients referred for a PET/CT were injected with either [18F]-FDG or [18F]-NaF and imaged on PET/CT (Biograph TruePoint/mCT, Siemens) and PET/MRI (mMR, Siemens) following a standard single-injection, dual-imaging clinical WB-protocol. Routine MR-AC was based on in-/opposed-phase MR imaging (orgMR-AC). PET...... and then investigate different strategies to account for bone tissue in clinical PET/MR imaging. To this purpose, bone tissue representation was extracted from separate CT images, and different bone representations were simulated from hypothetically derived MR-based bone classifications. Methods: Twenty oncology.......3%) and lowest for spongCT (–2.2%, range: 0.0% to –13.7%). Conclusions: In PET/MR imaging using standard MR-AC PET uptake values in soft lesions and bone lesions are underestimated by about 10%. In individual patients this bias can be as high as 22%, which is significant during clinical follow-up exams. If bone...

  13. Carbon Nanotubes/Gold Nanoparticles Composite Film for the Construction of a Novel Amperometric Choline Biosensor

    Directory of Open Access Journals (Sweden)

    Baoyan Wu

    2011-01-01

    Full Text Available This study develops a facile method to fabricate a novel choline biosensor based on multiwalled carbon nanotubes (MWCNTs and gold nanoparticles (AuNPs. Chitosan, a natural biocompatible polymer, was used to solubilize MWCNTs for constructing the aqueous Chit-MWCNTs solution. Then Chit-MWCNTs were first dropped on the surface of a cleaned platinum electrode. Finally, a thiolated silica sol containing AuNPs and choline oxidase (ChOx was immobilized on the surface of the Chit-MWCNTs-modified electrode. The MWCNTs/AuNPs/Pt electrode showed excellent electrocatalytic activity for choline. The resulting choline biosensor showed high sensitivity of choline (3.56 μA/mM, and wide linear range from 0.05 to 0.8 mM with the detection limit of 15 μM. In addition, good reproducibility and stability were obtained.

  14. Comparability of Computer-based and Paper-based Versions of Writing Section of PET in Iranian EFL Context

    OpenAIRE

    Mohammad Mohammadi; Masoud Barzgaran

    2010-01-01

    Computer technology has provided language testing experts with opportunity to develop computerized versions of traditional paper-based language tests. New generations of TOEFL and Cambridge IELTS, BULATS, KET, PET are good examples of computer-based language tests. Since this new method of testing introduces new factors into the realm of language assessment ( e.g. modes of test delivery, familiarity with computer, etc.),the question may be whether the two modes of computer- and paper-based te...

  15. Field of view extension and truncation correction for MR-based human attenuation correction in simultaneous MR/PET imaging

    International Nuclear Information System (INIS)

    Blumhagen, Jan O.; Ladebeck, Ralf; Fenchel, Matthias; Braun, Harald; Quick, Harald H.; Faul, David; Scheffler, Klaus

    2014-01-01

    Purpose: In quantitative PET imaging, it is critical to accurately measure and compensate for the attenuation of the photons absorbed in the tissue. While in PET/CT the linear attenuation coefficients can be easily determined from a low-dose CT-based transmission scan, in whole-body MR/PET the computation of the linear attenuation coefficients is based on the MR data. However, a constraint of the MR-based attenuation correction (AC) is the MR-inherent field-of-view (FoV) limitation due to static magnetic field (B 0 ) inhomogeneities and gradient nonlinearities. Therefore, the MR-based human AC map may be truncated or geometrically distorted toward the edges of the FoV and, consequently, the PET reconstruction with MR-based AC may be biased. This is especially of impact laterally where the patient arms rest beside the body and are not fully considered. Methods: A method is proposed to extend the MR FoV by determining an optimal readout gradient field which locally compensates B 0 inhomogeneities and gradient nonlinearities. This technique was used to reduce truncation in AC maps of 12 patients, and the impact on the PET quantification was analyzed and compared to truncated data without applying the FoV extension and additionally to an established approach of PET-based FoV extension. Results: The truncation artifacts in the MR-based AC maps were successfully reduced in all patients, and the mean body volume was thereby increased by 5.4%. In some cases large patient-dependent changes in SUV of up to 30% were observed in individual lesions when compared to the standard truncated attenuation map. Conclusions: The proposed technique successfully extends the MR FoV in MR-based attenuation correction and shows an improvement of PET quantification in whole-body MR/PET hybrid imaging. In comparison to the PET-based completion of the truncated body contour, the proposed method is also applicable to specialized PET tracers with little uptake in the arms and might reduce the

  16. Evaluation of Sinus/Edge-Corrected Zero-Echo-Time-Based Attenuation Correction in Brain PET/MRI.

    Science.gov (United States)

    Yang, Jaewon; Wiesinger, Florian; Kaushik, Sandeep; Shanbhag, Dattesh; Hope, Thomas A; Larson, Peder E Z; Seo, Youngho

    2017-11-01

    In brain PET/MRI, the major challenge of zero-echo-time (ZTE)-based attenuation correction (ZTAC) is the misclassification of air/tissue/bone mixtures or their boundaries. Our study aimed to evaluate a sinus/edge-corrected (SEC) ZTAC (ZTAC SEC ), relative to an uncorrected (UC) ZTAC (ZTAC UC ) and a CT atlas-based attenuation correction (ATAC). Methods: Whole-body 18 F-FDG PET/MRI scans were obtained for 12 patients after PET/CT scans. Only data acquired at a bed station that included the head were used for this study. Using PET data from PET/MRI, we applied ZTAC UC , ZTAC SEC , ATAC, and reference CT-based attenuation correction (CTAC) to PET attenuation correction. For ZTAC UC , the bias-corrected and normalized ZTE was converted to pseudo-CT with air (-1,000 HU for ZTE 0.75), and bone (-2,000 × [ZTE - 1] + 42 HU for 0.2 ≤ ZTE ≤ 0.75). Afterward, in the pseudo-CT, sinus/edges were automatically estimated as a binary mask through morphologic processing and edge detection. In the binary mask, the overestimated values were rescaled below 42 HU for ZTAC SEC For ATAC, the atlas deformed to MR in-phase was segmented to air, inner air, soft tissue, and continuous bone. For the quantitative evaluation, PET mean uptake values were measured in twenty 1-mL volumes of interest distributed throughout brain tissues. The PET uptake was compared using a paired t test. An error histogram was used to show the distribution of voxel-based PET uptake differences. Results: Compared with CTAC, ZTAC SEC achieved the overall PET quantification accuracy (0.2% ± 2.4%, P = 0.23) similar to CTAC, in comparison with ZTAC UC (5.6% ± 3.5%, P PET quantification in brain PET/MRI, comparable to the accuracy achieved by CTAC, particularly in the cerebellum. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  17. Rise of the machines : cyclotrons and radiopharmaceuticals in the PET-CT-MR golden age

    International Nuclear Information System (INIS)

    Price, Roger

    2011-01-01

    Full text: One particularly inspiring narrative in the evolution of medical imaging over 35 years begins with the introduction of quassi-routine production of 18F, enabled by advances in reliability of (medical) cyclotrons; invention of the 'molecule of the century' [18F]FOG and its robust synthesis; comprehending betrayal of major tumour-cell types by their glucose avidity; astounding advances in PET scanners (recently, time-of-flight); and marriage of anatomic with functional 3-D imaging as PET/CT or (recently) PET/MR. Though the explosion in PET is identified historically with diagnostic oncology plus quantitation of nuclear medicine, plus the collateral leverage of advances in CT and MR, other potentially transformative opportunities (pre-diagnosis or quantifying treatment response) are emerging in dementia and diabetes-as exemplars of PET-addressable mass afflictions-driven by advances in specificity/sensitivity of targeting molecules. PET delivers femto-M functional sensitivity (e.g.; receptor-targeting)-several magnitude-orders of narrow-context superiority over MR or CT-exemplified by the rapid rise of solid-targetry metallo-PET (64Cu, 89Zr), and concomitantly, preclinical radioimmuno micro-PET/CT/SPECT imaging. Though [11 C ] PET has elucidated brain, prostate and other cell +/- tumour mechanisms, realistic clinical rollout demands longer halflife [18F]-labelling. [18F] innovations beyond [18F]FDG elucidate numerous metabolisms, including choline, hypoxia, apoptosis and amino-acid, and notably will soon provide a routine-clinical [18F]-alternative to [11 C] based beta-amyloid dementia diagnosis. Frontier PET is constrained by cost/dose, shackled to 'twentieth century' technologies-cyclotron, hotcell and synthesis unit. Example is [18F] bone scintigraphy; acknowledged as clinically superior to [99mTc]MOP, its widespread implementation awaits cheaper isotope, accessible PET/CT scanners, and maybe 'true' shortage of [99mTc]. Generator-sourced 68 Ga-PET is

  18. Low-dose respiratory-gated PET/CT: based on 30 mA tube current

    International Nuclear Information System (INIS)

    Wu Ping; Li Sijin; Zhang Yanlan; Hao Xinzhong; Qin Zhixing; Yan Min; Cheng Pengliang; Wu Zhifang

    2013-01-01

    Objective: To establish a low-dose but image-comparable respiratory-gated PET/CT (RG PET/CT) protocol based on 30 mA tube current plus other improved scanning parameters, such as the tube current, the number of respiratory phase and length of breathing cycle. Methods: Twenty-six patients with 18 F-FDG-intaking lung nodules underwent one-bed standard-dose PET/CT (120 mA, 2 min/bed) and low dose RG PET/CT (30 mA, 6 respiratory phases, 1 min/phase). The radiation dose and image quality were analyzed subsequently with signal to noise ratio (SNR) for PET and the homogeneity, noise level for CT in the water phantom respectively. Otherwise the CT images were both visual evaluated by two experienced doctors. In addition, different respiratory cycle was simulated to observe its relation with radiation dose. Results: The effective dose of low-dose RG PET/CT was 4.88∼7.69 mSv [mean (5.68±0.83) mSv]. The PET SNR showed no significance between groups. The homogeneity of 30 mA is good (< 5 HU), although noise level was high, the visual character like lobulation, speculation of lung nodule was superior in some respiratory phases. The radiation dose was positively correlated with respiratory cycle. Conclusions: The performance of low-dose RG PET/CT was comparable to those of standard-dose PET/CT based on a protocol with 30 mA tube current, 6 respiratory phases and breathing state of eupnoea. It produced a much lower radiation exposure and the image quality was enough for clinical use such as delineation of tumor active target, characterization and staging of lung nodules, etc. (authors)

  19. Internet2-based 3D PET image reconstruction using a PC cluster

    International Nuclear Information System (INIS)

    Shattuck, D.W.; Rapela, J.; Asma, E.; Leahy, R.M.; Chatzioannou, A.; Qi, J.

    2002-01-01

    We describe an approach to fast iterative reconstruction from fully three-dimensional (3D) PET data using a network of PentiumIII PCs configured as a Beowulf cluster. To facilitate the use of this system, we have developed a browser-based interface using Java. The system compresses PET data on the user's machine, sends these data over a network, and instructs the PC cluster to reconstruct the image. The cluster implements a parallelized version of our preconditioned conjugate gradient method for fully 3D MAP image reconstruction. We report on the speed-up factors using the Beowulf approach and the impacts of communication latencies in the local cluster network and the network connection between the user's machine and our PC cluster. (author)

  20. Kinetic parametric estimation in animal PET molecular imaging based on artificial immune network

    International Nuclear Information System (INIS)

    Chen Yuting; Ding Hong; Lu Rui; Huang Hongbo; Liu Li

    2011-01-01

    Objective: To develop an accurate,reliable method without the need of initialization in animal PET modeling for estimation of the tracer kinetic parameters based on the artificial immune network. Methods: The hepatic and left ventricular time activity curves (TACs) were obtained by drawing ROIs of liver tissue and left ventricle on dynamic 18 F-FDG PET imaging of small mice. Meanwhile, the blood TAC was analyzed by sampling the tail vein blood at different time points after injection. The artificial immune network for parametric optimization of pharmacokinetics (PKAIN) was adapted to estimate the model parameters and the metabolic rate of glucose (K i ) was calculated. Results: TACs of liver,left ventricle and tail vein blood were obtained.Based on the artificial immune network, K i in 3 mice was estimated as 0.0024, 0.0417 and 0.0047, respectively. The average weighted residual sum of squares of the output model generated by PKAIN was less than 0.0745 with a maximum standard deviation of 0.0084, which indicated that the proposed PKAIN method can provide accurate and reliable parametric estimation. Conclusion: The PKAIN method could provide accurate and reliable tracer kinetic modeling in animal PET imaging without the need of initialization of model parameters. (authors)

  1. Event-based motion correction for PET transmission measurements with a rotating point source

    International Nuclear Information System (INIS)

    Zhou, Victor W; Kyme, Andre Z; Meikle, Steven R; Fulton, Roger

    2011-01-01

    Accurate attenuation correction is important for quantitative positron emission tomography (PET) studies. When performing transmission measurements using an external rotating radioactive source, object motion during the transmission scan can distort the attenuation correction factors computed as the ratio of the blank to transmission counts, and cause errors and artefacts in reconstructed PET images. In this paper we report a compensation method for rigid body motion during PET transmission measurements, in which list mode transmission data are motion corrected event-by-event, based on known motion, to ensure that all events which traverse the same path through the object are recorded on a common line of response (LOR). As a result, the motion-corrected transmission LOR may record a combination of events originally detected on different LORs. To ensure that the corresponding blank LOR records events from the same combination of contributing LORs, the list mode blank data are spatially transformed event-by-event based on the same motion information. The number of counts recorded on the resulting blank LOR is then equivalent to the number of counts that would have been recorded on the corresponding motion-corrected transmission LOR in the absence of any attenuating object. The proposed method has been verified in phantom studies with both stepwise movements and continuous motion. We found that attenuation maps derived from motion-corrected transmission and blank data agree well with those of the stationary phantom and are significantly better than uncorrected attenuation data.

  2. Interval-based reconstruction for uncertainty quantification in PET

    Science.gov (United States)

    Kucharczak, Florentin; Loquin, Kevin; Buvat, Irène; Strauss, Olivier; Mariano-Goulart, Denis

    2018-02-01

    A new directed interval-based tomographic reconstruction algorithm, called non-additive interval based expectation maximization (NIBEM) is presented. It uses non-additive modeling of the forward operator that provides intervals instead of single-valued projections. The detailed approach is an extension of the maximum likelihood—expectation maximization algorithm based on intervals. The main motivation for this extension is that the resulting intervals have appealing properties for estimating the statistical uncertainty associated with the reconstructed activity values. After reviewing previously published theoretical concepts related to interval-based projectors, this paper describes the NIBEM algorithm and gives examples that highlight the properties and advantages of this interval valued reconstruction.

  3. NMR (1H and 13C) based signatures of abnormal choline metabolism in oral squamous cell carcinoma with no prominent Warburg effect

    International Nuclear Information System (INIS)

    Bag, Swarnendu; Banerjee, Deb Ranjan; Basak, Amit; Das, Amit Kumar; Pal, Mousumi; Banerjee, Rita; Paul, Ranjan Rashmi; Chatterjee, Jyotirmoy

    2015-01-01

    At functional levels, besides genes and proteins, changes in metabolome profiles are instructive for a biological system in health and disease including malignancy. It is understood that metabolomic alterations in association with proteomic and transcriptomic aberrations are very fundamental to unravel malignant micro-ambient criticality and oral cancer is no exception. Hence deciphering intricate dimensions of oral cancer metabolism may be contributory both for integrated appreciation of its pathogenesis and to identify any critical but yet unexplored dimension of this malignancy with high mortality rate. Although several methods do exist, NMR provides higher analytical precision in identification of cancer metabolomic signature. Present study explored abnormal signatures in choline metabolism in oral squamous cell carcinoma (OSCC) using 1 H and 13 C NMR analysis of serum. It has demonstrated down-regulation of choline with concomitant up-regulation of its break-down product in the form of trimethylamine N-oxide in OSCC compared to normal counterpart. Further, no significant change in lactate profile in OSCC possibly indicated that well-known Warburg effect was not a prominent phenomenon in such malignancy. Amongst other important metabolites, malonate has shown up-regulation but D-glucose, saturated fatty acids, acetate and threonine did not show any significant change. Analyzing these metabolomic findings present study proposed trimethyl amine N-oxide and malonate as important metabolic signature for oral cancer with no prominent Warburg effect. - Highlights: • NMR ( 1 H and 13 C) study of Oral Squamous cell Carcinoma Serum. • Abnormal Choline metabolomic signatures. • Up-regulation of Trimethylamine N-oxide. • Unchanged lactate profile indicates no prominent Warburg effect. • Proposed alternative glucose metabolism path through up-regulation of malonate

  4. NMR ({sup 1}H and {sup 13}C) based signatures of abnormal choline metabolism in oral squamous cell carcinoma with no prominent Warburg effect

    Energy Technology Data Exchange (ETDEWEB)

    Bag, Swarnendu, E-mail: Swarna.bag@gmail.com [School of Medical Science and Technology, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India); Banerjee, Deb Ranjan, E-mail: debranjan2@gmail.com [Department of Chemistry, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India); Basak, Amit, E-mail: absk@chem.iitkgp.ernet.in [Department of Chemistry, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India); Das, Amit Kumar, E-mail: amitk@hijli.iitkgp.ernet.in [Department of Biotechnology, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India); Pal, Mousumi, E-mail: drmpal62@gmail.com [Department of Oral and Maxillofacial Pathology, Guru Nanak Institute of Dental Sciences and Research, Kolkata, West Bengal (India); Banerjee, Rita, E-mail: ritabanerjee@outlook.com [Department of Science and Technology, New Mehrauli Road, New Delhi 110016 (India); Paul, Ranjan Rashmi, E-mail: dr_rsspaul@yahoo.co.in [Department of Oral and Maxillofacial Pathology, Guru Nanak Institute of Dental Sciences and Research, Kolkata, West Bengal (India); Chatterjee, Jyotirmoy, E-mail: jchatterjee.iitkgp@gmail.com [School of Medical Science and Technology, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India)

    2015-04-17

    At functional levels, besides genes and proteins, changes in metabolome profiles are instructive for a biological system in health and disease including malignancy. It is understood that metabolomic alterations in association with proteomic and transcriptomic aberrations are very fundamental to unravel malignant micro-ambient criticality and oral cancer is no exception. Hence deciphering intricate dimensions of oral cancer metabolism may be contributory both for integrated appreciation of its pathogenesis and to identify any critical but yet unexplored dimension of this malignancy with high mortality rate. Although several methods do exist, NMR provides higher analytical precision in identification of cancer metabolomic signature. Present study explored abnormal signatures in choline metabolism in oral squamous cell carcinoma (OSCC) using {sup 1}H and {sup 13}C NMR analysis of serum. It has demonstrated down-regulation of choline with concomitant up-regulation of its break-down product in the form of trimethylamine N-oxide in OSCC compared to normal counterpart. Further, no significant change in lactate profile in OSCC possibly indicated that well-known Warburg effect was not a prominent phenomenon in such malignancy. Amongst other important metabolites, malonate has shown up-regulation but D-glucose, saturated fatty acids, acetate and threonine did not show any significant change. Analyzing these metabolomic findings present study proposed trimethyl amine N-oxide and malonate as important metabolic signature for oral cancer with no prominent Warburg effect. - Highlights: • NMR ({sup 1}H and {sup 13}C) study of Oral Squamous cell Carcinoma Serum. • Abnormal Choline metabolomic signatures. • Up-regulation of Trimethylamine N-oxide. • Unchanged lactate profile indicates no prominent Warburg effect. • Proposed alternative glucose metabolism path through up-regulation of malonate.

  5. 4D offline PET-based treatment verification in ion beam therapy. Experimental and clinical evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, Christopher

    2014-06-12

    Due to the accessible sharp dose gradients, external beam radiotherapy with protons and heavier ions enables a highly conformal adaptation of the delivered dose to arbitrarily shaped tumour volumes. However, this high conformity is accompanied by an increased sensitivity to potential uncertainties, e.g., due to changes in the patient anatomy. Additional challenges are imposed by respiratory motion which does not only lead to rapid changes of the patient anatomy, but, in the cased of actively scanned ions beams, also to the formation of dose inhomogeneities. Therefore, it is highly desirable to verify the actual application of the treatment and to detect possible deviations with respect to the planned irradiation. At present, the only clinically implemented approach for a close-in-time verification of single treatment fractions is based on detecting the distribution of β{sup +}-emitter formed in nuclear fragmentation reactions during the irradiation by means of positron emission tomography (PET). For this purpose, a commercial PET/CT (computed tomography) scanner has been installed directly next to the treatment rooms at the Heidelberg Ion-Beam Therapy Center (HIT). Up to present, the application of this treatment verification technique is, however, still limited to static target volumes. This thesis aimed at investigating the feasibility and performance of PET-based treatment verification under consideration of organ motion. In experimental irradiation studies with moving phantoms, not only the practicability of PET-based treatment monitoring for moving targets, using a commercial PET/CT device, could be shown for the first time, but also the potential of this technique to detect motion-related deviations from the planned treatment with sub-millimetre accuracy. The first application to four exemplary hepato-cellular carcinoma patient cases under substantially more challenging clinical conditions indicated potential for improvement by taking organ motion into

  6. 4D offline PET-based treatment verification in ion beam therapy. Experimental and clinical evaluation

    International Nuclear Information System (INIS)

    Kurz, Christopher

    2014-01-01

    Due to the accessible sharp dose gradients, external beam radiotherapy with protons and heavier ions enables a highly conformal adaptation of the delivered dose to arbitrarily shaped tumour volumes. However, this high conformity is accompanied by an increased sensitivity to potential uncertainties, e.g., due to changes in the patient anatomy. Additional challenges are imposed by respiratory motion which does not only lead to rapid changes of the patient anatomy, but, in the cased of actively scanned ions beams, also to the formation of dose inhomogeneities. Therefore, it is highly desirable to verify the actual application of the treatment and to detect possible deviations with respect to the planned irradiation. At present, the only clinically implemented approach for a close-in-time verification of single treatment fractions is based on detecting the distribution of β + -emitter formed in nuclear fragmentation reactions during the irradiation by means of positron emission tomography (PET). For this purpose, a commercial PET/CT (computed tomography) scanner has been installed directly next to the treatment rooms at the Heidelberg Ion-Beam Therapy Center (HIT). Up to present, the application of this treatment verification technique is, however, still limited to static target volumes. This thesis aimed at investigating the feasibility and performance of PET-based treatment verification under consideration of organ motion. In experimental irradiation studies with moving phantoms, not only the practicability of PET-based treatment monitoring for moving targets, using a commercial PET/CT device, could be shown for the first time, but also the potential of this technique to detect motion-related deviations from the planned treatment with sub-millimetre accuracy. The first application to four exemplary hepato-cellular carcinoma patient cases under substantially more challenging clinical conditions indicated potential for improvement by taking organ motion into

  7. 18F-fluorocholine PET-guided target volume delineation techniques for partial prostate re-irradiation in local recurrent prostate cancer

    International Nuclear Information System (INIS)

    Wang Hui; Vees, Hansjoerg; Miralbell, Raymond; Wissmeyer, Michael; Steiner, Charles; Ratib, Osman; Senthamizhchelvan, Srinivasan; Zaidi, Habib

    2009-01-01

    Background and purpose: We evaluate the contribution of 18 F-choline PET/CT in the delineation of gross tumour volume (GTV) in local recurrent prostate cancer after initial irradiation using various PET image segmentation techniques. Materials and methods: Seventeen patients with local-only recurrent prostate cancer (median = 5.7 years) after initial irradiation were included in the study. Rebiopsies were performed in 10 patients that confirmed the local recurrence. Following injection of 300 MBq of 18 F-fluorocholine, dynamic PET frames (3 min each) were reconstructed from the list-mode acquisition. Five PET image segmentation techniques were used to delineate the 18 F-choline-based GTVs. These included manual delineation of contours (GTV man ) by two teams consisting of a radiation oncologist and a nuclear medicine physician each, a fixed threshold of 40% and 50% of the maximum signal intensity (GTV 40% and GTV 50% ), signal-to-background ratio-based adaptive thresholding (GTV SBR ), and a region growing (GTV RG ) algorithm. Geographic mismatches between the GTVs were also assessed using overlap analysis. Results: Inter-observer variability for manual delineation of GTVs was high but not statistically significant (p = 0.459). In addition, the volumes and shapes of GTVs delineated using semi-automated techniques were significantly higher than those of GTVs defined manually. Conclusions: Semi-automated segmentation techniques for 18 F-choline PET-guided GTV delineation resulted in substantially higher GTVs compared to manual delineation and might replace the latter for determination of recurrent prostate cancer for partial prostate re-irradiation. The selection of the most appropriate segmentation algorithm still needs to be determined.

  8. 18F-fluorocholine PET-guided target volume delineation techniques for partial prostate re-irradiation in local recurrent prostate cancer.

    Science.gov (United States)

    Wang, Hui; Vees, Hansjörg; Miralbell, Raymond; Wissmeyer, Michael; Steiner, Charles; Ratib, Osman; Senthamizhchelvan, Srinivasan; Zaidi, Habib

    2009-11-01

    We evaluate the contribution of (18)F-choline PET/CT in the delineation of gross tumour volume (GTV) in local recurrent prostate cancer after initial irradiation using various PET image segmentation techniques. Seventeen patients with local-only recurrent prostate cancer (median=5.7 years) after initial irradiation were included in the study. Rebiopsies were performed in 10 patients that confirmed the local recurrence. Following injection of 300 MBq of (18)F-fluorocholine, dynamic PET frames (3 min each) were reconstructed from the list-mode acquisition. Five PET image segmentation techniques were used to delineate the (18)F-choline-based GTVs. These included manual delineation of contours (GTV(man)) by two teams consisting of a radiation oncologist and a nuclear medicine physician each, a fixed threshold of 40% and 50% of the maximum signal intensity (GTV(40%) and GTV(50%)), signal-to-background ratio-based adaptive thresholding (GTV(SBR)), and a region growing (GTV(RG)) algorithm. Geographic mismatches between the GTVs were also assessed using overlap analysis. Inter-observer variability for manual delineation of GTVs was high but not statistically significant (p=0.459). In addition, the volumes and shapes of GTVs delineated using semi-automated techniques were significantly higher than those of GTVs defined manually. Semi-automated segmentation techniques for (18)F-choline PET-guided GTV delineation resulted in substantially higher GTVs compared to manual delineation and might replace the latter for determination of recurrent prostate cancer for partial prostate re-irradiation. The selection of the most appropriate segmentation algorithm still needs to be determined.

  9. Application of machine learning methodology for pet-based definition of lung cancer

    Science.gov (United States)

    Kerhet, A.; Small, C.; Quon, H.; Riauka, T.; Schrader, L.; Greiner, R.; Yee, D.; McEwan, A.; Roa, W.

    2010-01-01

    We applied a learning methodology framework to assist in the threshold-based segmentation of non-small-cell lung cancer (nsclc) tumours in positron-emission tomography–computed tomography (pet–ct) imaging for use in radiotherapy planning. Gated and standard free-breathing studies of two patients were independently analysed (four studies in total). Each study had a pet–ct and a treatment-planning ct image. The reference gross tumour volume (gtv) was identified by two experienced radiation oncologists who also determined reference standardized uptake value (suv) thresholds that most closely approximated the gtv contour on each slice. A set of uptake distribution-related attributes was calculated for each pet slice. A machine learning algorithm was trained on a subset of the pet slices to cope with slice-to-slice variation in the optimal suv threshold: that is, to predict the most appropriate suv threshold from the calculated attributes for each slice. The algorithm’s performance was evaluated using the remainder of the pet slices. A high degree of geometric similarity was achieved between the areas outlined by the predicted and the reference suv thresholds (Jaccard index exceeding 0.82). No significant difference was found between the gated and the free-breathing results in the same patient. In this preliminary work, we demonstrated the potential applicability of a machine learning methodology as an auxiliary tool for radiation treatment planning in nsclc. PMID:20179802

  10. A local contrast based approach to threshold segmentation for PET target volume delineation

    International Nuclear Information System (INIS)

    Drever, Laura; Robinson, Don M.; McEwan, Alexander; Roa, Wilson

    2006-01-01

    Current radiation therapy techniques, such as intensity modulated radiation therapy and three-dimensional conformal radiotherapy rely on the precise delivery of high doses of radiation to well-defined volumes. CT, the imaging modality that is most commonly used to determine treatment volumes cannot, however, easily distinguish between cancerous and normal tissue. The ability of positron emission tomography (PET) to more readily differentiate between malignant and healthy tissues has generated great interest in using PET images to delineate target volumes for radiation treatment planning. At present the accurate geometric delineation of tumor volumes is a subject open to considerable interpretation. The possibility of using a local contrast based approach to threshold segmentation to accurately delineate PET target cross sections is investigated using well-defined cylindrical and spherical volumes. Contrast levels which yield correct volumetric quantification are found to be a function of the activity concentration ratio between target and background, target size, and slice location. Possibilities for clinical implementation are explored along with the limits posed by this form of segmentation

  11. Automated analysis of PET based in-vivo monitoring in ion beam therapy

    International Nuclear Information System (INIS)

    Kuess, P.

    2014-01-01

    Particle Therapy (PT)-PET is currently the only clinically approved in-vivo method for monitoring PT. Due to fragmentation processes in the patients' tissue and the beam projectiles, a beta plus activity distribution (BAD) can be measured during or shortly after the irradiation. The recorded activity map can not be directly compared to the planned dose distribution. However, by means of a Monte Carlo (MC) simulation it is possible to predict the measured BAD from a treatment plan (TP). Thus to verify a patient's treatment fraction the actual PET measurement can be compared to the respective BAD prediction. This comparison is currently performed by visual inspection which requires experienced evaluators and is rather time consuming. In this PhD thesis an evaluation tool is presented to compare BADs in an automated and objective way. The evaluation method was based on the Pearson's correlation coefficient (PCC) – an established measure in medical image processing – which was coded into a software tool. The patient data used to develop, test and validate the software tool were acquired at the GSI research facility where over 400 patient treatments with 12C were monitored by means of an in-beam PET prototype. The number of data sets was increased by artificially altering BAD to simulate different beam ranges. The automated detection tool was tested in head and neck (H&N), prostate, lung, and brain. To generate carbon ion TPs the treatment planning system TRiP98 was used for all cases. From these TPs the respective BAD predictions were derived. Besides the detection of range deviations by means of PT-PET also the automated detection of patient setup uncertainties was investigated. Although all measured patient data were recorded during the irradiation (in-beam) also scenarios performing PET scans shortly after the irradiation (in-room) were considered. To analyze the achievable precision of PT-PET with the automated evaluation tool based on

  12. A Novel Kernel-Based Regularization Technique for PET Image Reconstruction

    Directory of Open Access Journals (Sweden)

    Abdelwahhab Boudjelal

    2017-06-01

    Full Text Available Positron emission tomography (PET is an imaging technique that generates 3D detail of physiological processes at the cellular level. The technique requires a radioactive tracer, which decays and releases a positron that collides with an electron; consequently, annihilation photons are emitted, which can be measured. The purpose of PET is to use the measurement of photons to reconstruct the distribution of radioisotopes in the body. Currently, PET is undergoing a revamp, with advancements in data measurement instruments and the computing methods used to create the images. These computer methods are required to solve the inverse problem of “image reconstruction from projection”. This paper proposes a novel kernel-based regularization technique for maximum-likelihood expectation-maximization ( κ -MLEM to reconstruct the image. Compared to standard MLEM, the proposed algorithm is more robust and is more effective in removing background noise, whilst preserving the edges; this suppresses image artifacts, such as out-of-focus slice blur.

  13. Metabolic patterns in prion diseases: an FDG PET voxel-based analysis

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, Elena; Dominguez-Prado, Ines; Jesus Ribelles, Maria; Arbizu, Javier [Clinica Universidad de Navarra, Nuclear Medicine Department, Pamplona (Spain); Riverol, Mario; Ortega-Cubero, Sara; Rosario Luquin, Maria; Castro, Purificacion de [Clinica Universidad de Navarra, Neurology Department, Pamplona (Spain)

    2015-09-15

    Clinical diagnosis of human prion diseases can be challenging since symptoms are common to other disorders associated with rapidly progressive dementia. In this context, {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET) might be a useful complementary tool. The aim of this study was to determine the metabolic pattern in human prion diseases, particularly sporadic Creutzfeldt-Jakob disease (sCJD), the new variant of Creutzfeldt-Jakob disease (vCJD) and fatal familial insomnia (FFI). We retrospectively studied 17 patients with a definitive, probable or possible prion disease who underwent FDG PET in our institution. Of these patients, 12 were diagnosed as sCJD (9 definitive, 2 probable and 1 possible), 1 was diagnosed as definitive vCJD and 4 were diagnosed as definitive FFI. The hypometabolic pattern of each individual and comparisons across the groups of subjects (control subjects, sCJD and FFI) were evaluated using a voxel-based analysis. The sCJD group exhibited a pattern of hypometabolism that affected both subcortical (bilateral caudate, thalamus) and cortical (frontal cortex) structures, while the FFI group only presented a slight hypometabolism in the thalamus. Individual analysis demonstrated a considerable variability of metabolic patterns among patients, with the thalamus and basal ganglia the most frequently affected areas, combined in some cases with frontal and temporal hypometabolism. Patients with a prion disease exhibit a characteristic pattern of brain metabolism presentation in FDG PET imaging. Consequently, in patients with rapidly progressive cognitive impairment, the detection of these patterns in the FDG PET study could orient the diagnosis to a prion disease. (orig.)

  14. Metabolic patterns in prion diseases: an FDG PET voxel-based analysis

    International Nuclear Information System (INIS)

    Prieto, Elena; Dominguez-Prado, Ines; Jesus Ribelles, Maria; Arbizu, Javier; Riverol, Mario; Ortega-Cubero, Sara; Rosario Luquin, Maria; Castro, Purificacion de

    2015-01-01

    Clinical diagnosis of human prion diseases can be challenging since symptoms are common to other disorders associated with rapidly progressive dementia. In this context, 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) might be a useful complementary tool. The aim of this study was to determine the metabolic pattern in human prion diseases, particularly sporadic Creutzfeldt-Jakob disease (sCJD), the new variant of Creutzfeldt-Jakob disease (vCJD) and fatal familial insomnia (FFI). We retrospectively studied 17 patients with a definitive, probable or possible prion disease who underwent FDG PET in our institution. Of these patients, 12 were diagnosed as sCJD (9 definitive, 2 probable and 1 possible), 1 was diagnosed as definitive vCJD and 4 were diagnosed as definitive FFI. The hypometabolic pattern of each individual and comparisons across the groups of subjects (control subjects, sCJD and FFI) were evaluated using a voxel-based analysis. The sCJD group exhibited a pattern of hypometabolism that affected both subcortical (bilateral caudate, thalamus) and cortical (frontal cortex) structures, while the FFI group only presented a slight hypometabolism in the thalamus. Individual analysis demonstrated a considerable variability of metabolic patterns among patients, with the thalamus and basal ganglia the most frequently affected areas, combined in some cases with frontal and temporal hypometabolism. Patients with a prion disease exhibit a characteristic pattern of brain metabolism presentation in FDG PET imaging. Consequently, in patients with rapidly progressive cognitive impairment, the detection of these patterns in the FDG PET study could orient the diagnosis to a prion disease. (orig.)

  15. Skull base meningioma. Surgical and adjuvant treatment with clinical and PET evaluation

    International Nuclear Information System (INIS)

    Gudjonsson, O.

    2001-01-01

    The treatment strategy for skull base meningiomas remains a controversial issue. Because of the proximity of these tumours to critical neurovascular structures, the risk for vascular damage and new cranial neuropathies postoperatively is significant. To avoid unacceptable neurological deficits the surgical treatment strategy includes different surgical approaches and a subtotal removal of these tumours in some cases. However, because the rate of recurrence and progression is significant in these patients, a demand for adjuvant treatment and better prognostic methods is called for so that treatment and follow-up can be tailored to each patient. Accordingly, we have chosen to evaluate general outcome and facial nerve function after translabyrinthine and transcochlear approaches for cerebellopontine angle (CPA) meningiomas. Furthermore, we have evaluated two adjuvant treatments, namely, irradiation by high-energy proton beams and medical treatment with interferon-alpha as well as evaluation of the treatment effect with 11 C-L-methionine PET. In addition, we have evaluated a new PET tracer ( 76 Br-BrdU) for 'in vivo' determination of the growth potential of intracranial tumours. Conclusion: The translabyrinthine and transcochlear approaches are apparently safe surgical procedures in the treatment of CPA meningiomas. Proton beam therapy is technically feasible as suggested by the fact that only minimal side effects were observed. Moreover, none of the meningiomas treated have shown progression during a 36-month follow-up. Our results indicate that IFN-alpha can be an effective oncostatic treatment for certain patients with meningiomas. The 11 C-L-methionine PET method might be used as a complement to CT or MRI in the evaluation of the effect of proton beam and IFN-alpha treatment in meningiomas. The present attempt failed to demonstrate that the PET tracer 76 Br-BrdU could be used for the non-invasive characterisation of growth potential in brain, tumours

  16. Skull base meningioma. Surgical and adjuvant treatment with clinical and PET evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Gudjonsson, O

    2001-05-01

    The treatment strategy for skull base meningiomas remains a controversial issue. Because of the proximity of these tumours to critical neurovascular structures, the risk for vascular damage and new cranial neuropathies postoperatively is significant. To avoid unacceptable neurological deficits the surgical treatment strategy includes different surgical approaches and a subtotal removal of these tumours in some cases. However, because the rate of recurrence and progression is significant in these patients, a demand for adjuvant treatment and better prognostic methods is called for so that treatment and follow-up can be tailored to each patient. Accordingly, we have chosen to evaluate general outcome and facial nerve function after translabyrinthine and transcochlear approaches for cerebellopontine angle (CPA) meningiomas. Furthermore, we have evaluated two adjuvant treatments, namely, irradiation by high-energy proton beams and medical treatment with interferon-alpha as well as evaluation of the treatment effect with {sup 11}C-L-methionine PET. In addition, we have evaluated a new PET tracer ({sup 76}Br-BrdU) for 'in vivo' determination of the growth potential of intracranial tumours. Conclusion: The translabyrinthine and transcochlear approaches are apparently safe surgical procedures in the treatment of CPA meningiomas. Proton beam therapy is technically feasible as suggested by the fact that only minimal side effects were observed. Moreover, none of the meningiomas treated have shown progression during a 36-month follow-up. Our results indicate that IFN-alpha can be an effective oncostatic treatment for certain patients with meningiomas. The {sup 11}C-L-methionine PET method might be used as a complement to CT or MRI in the evaluation of the effect of proton beam and IFN-alpha treatment in meningiomas. The present attempt failed to demonstrate that the PET tracer {sup 76}Br-BrdU could be used for the non-invasive characterisation of growth potential in

  17. Image-based Modeling of PSF Deformation with Application to Limited Angle PET Data

    Science.gov (United States)

    Matej, Samuel; Li, Yusheng; Panetta, Joseph; Karp, Joel S.; Surti, Suleman

    2016-01-01

    The point-spread-functions (PSFs) of reconstructed images can be deformed due to detector effects such as resolution blurring and parallax error, data acquisition geometry such as insufficient sampling or limited angular coverage in dual-panel PET systems, or reconstruction imperfections/simplifications. PSF deformation decreases quantitative accuracy and its spatial variation lowers consistency of lesion uptake measurement across the imaging field-of-view (FOV). This can be a significant problem with dual panel PET systems even when using TOF data and image reconstruction models of the detector and data acquisition process. To correct for the spatially variant reconstructed PSF distortions we propose to use an image-based resolution model (IRM) that includes such image PSF deformation effects. Originally the IRM was mostly used for approximating data resolution effects of standard PET systems with full angular coverage in a computationally efficient way, but recently it was also used to mitigate effects of simplified geometric projectors. Our work goes beyond this by including into the IRM reconstruction imperfections caused by combination of the limited angle, parallax errors, and any other (residual) deformation effects and testing it for challenging dual panel data with strongly asymmetric and variable PSF deformations. We applied and tested these concepts using simulated data based on our design for a dedicated breast imaging geometry (B-PET) consisting of dual-panel, time-of-flight (TOF) detectors. We compared two image-based resolution models; i) a simple spatially invariant approximation to PSF deformation, which captures only the general PSF shape through an elongated 3D Gaussian function, and ii) a spatially variant model using a Gaussian mixture model (GMM) to more accurately capture the asymmetric PSF shape in images reconstructed from data acquired with the B-PET scanner geometry. Results demonstrate that while both IRMs decrease the overall uptake

  18. Pathology-based validation of FDG PET segmentation tools for volume assessment of lymph node metastases from head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Schinagl, Dominic A.X. [Radboud University Nijmegen Medical Centre, Department of Radiation Oncology, Nijmegen (Netherlands); Radboud University Nijmegen Medical Centre, Department of Radiation Oncology (874), P.O. Box 9101, Nijmegen (Netherlands); Span, Paul N.; Kaanders, Johannes H.A.M. [Radboud University Nijmegen Medical Centre, Department of Radiation Oncology, Nijmegen (Netherlands); Hoogen, Frank J.A. van den [Radboud University Nijmegen Medical Centre, Department of Otorhinolaryngology, Head and Neck Surgery, Nijmegen (Netherlands); Merkx, Matthias A.W. [Radboud University Nijmegen Medical Centre, Department of Oral and Maxillofacial Surgery, Nijmegen (Netherlands); Slootweg, Piet J. [Radboud University Nijmegen Medical Centre, Department of Pathology, Nijmegen (Netherlands); Oyen, Wim J.G. [Radboud University Nijmegen Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands)

    2013-12-15

    FDG PET is increasingly incorporated into radiation treatment planning of head and neck cancer. However, there are only limited data on the accuracy of radiotherapy target volume delineation by FDG PET. The purpose of this study was to validate FDG PET segmentation tools for volume assessment of lymph node metastases from head and neck cancer against the pathological method as the standard. Twelve patients with head and neck cancer and 28 metastatic lymph nodes eligible for therapeutic neck dissection underwent preoperative FDG PET/CT. The metastatic lymph nodes were delineated on CT (Node{sub CT}) and ten PET segmentation tools were used to assess FDG PET-based nodal volumes: interpreting FDG PET visually (PET{sub VIS}), applying an isocontour at a standardized uptake value (SUV) of 2.5 (PET{sub SUV}), two segmentation tools with a fixed threshold of 40 % and 50 %, and two adaptive threshold based methods. The latter four tools were applied with the primary tumour as reference and also with the lymph node itself as reference. Nodal volumes were compared with the true volume as determined by pathological examination. Both Node{sub CT} and PET{sub VIS} showed good correlations with the pathological volume. PET segmentation tools using the metastatic node as reference all performed well but not better than PET{sub VIS}. The tools using the primary tumour as reference correlated poorly with pathology. PET{sub SUV} was unsatisfactory in 35 % of the patients due to merging of the contours of adjacent nodes. FDG PET accurately estimates metastatic lymph node volume, but beyond the detection of lymph node metastases (staging), it has no added value over CT alone for the delineation of routine radiotherapy target volumes. If FDG PET is used in radiotherapy planning, treatment adaptation or response assessment, we recommend an automated segmentation method for purposes of reproducibility and interinstitutional comparison. (orig.)

  19. Clinical significance of creative 3D-image fusion across multimodalities [PET + CT + MR] based on characteristic coregistration

    International Nuclear Information System (INIS)

    Peng, Matthew Jian-qiao; Ju Xiangyang; Khambay, Balvinder S.; Ayoub, Ashraf F.; Chen, Chin-Tu; Bai Bo

    2012-01-01

    Objective: To investigate a registration approach for 2-dimension (2D) based on characteristic localization to achieve 3-dimension (3D) fusion from images of PET, CT and MR one by one. Method: A cubic oriented scheme of“9-point and 3-plane” for co-registration design was verified to be geometrically practical. After acquisiting DICOM data of PET/CT/MR (directed by radiotracer 18 F-FDG etc.), through 3D reconstruction and virtual dissection, human internal feature points were sorted to combine with preselected external feature points for matching process. By following the procedure of feature extraction and image mapping, “picking points to form planes” and “picking planes for segmentation” were executed. Eventually, image fusion was implemented at real-time workstation mimics based on auto-fuse techniques so called “information exchange” and “signal overlay”. Result: The 2D and 3D images fused across modalities of [CT + MR], [PET + MR], [PET + CT] and [PET + CT + MR] were tested on data of patients suffered from tumors. Complementary 2D/3D images simultaneously presenting metabolic activities and anatomic structures were created with detectable-rate of 70%, 56%, 54% (or 98%) and 44% with no significant difference for each in statistics. Conclusion: Currently, based on the condition that there is no complete hybrid detector integrated of triple-module [PET + CT + MR] internationally, this sort of multiple modality fusion is doubtlessly an essential complement for the existing function of single modality imaging.

  20. Relationship Between Organophosphate Toxicity and Choline Metabolism

    Science.gov (United States)

    1986-06-06

    Results from studies on the actions of the organophosphates on the central nervus system have suggested that these compounds, through an action on...Grganophosphates alter the disposition and metabolism of choline and choline-containing compounds in the nervous system , the relationshi ý of these changes to...mechanisms regulating the metabolism of choline, as well as the specific interactions of the organophospha:es with biochemical systems , may differ

  1. GPU based Monte Carlo for PET image reconstruction: detector modeling

    International Nuclear Information System (INIS)

    Légrády; Cserkaszky, Á; Lantos, J.; Patay, G.; Bükki, T.

    2011-01-01

    Monte Carlo (MC) calculations and Graphical Processing Units (GPUs) are almost like the dedicated hardware designed for the specific task given the similarities between visible light transport and neutral particle trajectories. A GPU based MC gamma transport code has been developed for Positron Emission Tomography iterative image reconstruction calculating the projection from unknowns to data at each iteration step taking into account the full physics of the system. This paper describes the simplified scintillation detector modeling and its effect on convergence. (author)

  2. Effects on Mechanical Properties of Recycled PET in Cement-Based Composites

    Directory of Open Access Journals (Sweden)

    Liliana Ávila Córdoba

    2013-01-01

    Full Text Available Concretes consisting of portland cement (OPC, silica sand, gravel, water, and recycled PET particles were developed. Specimens without PET particles were prepared for comparison. Curing times, PET particle sizes, and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and Young modulus were determined. Morphological and chemical compositions of recycled PET particles were seen in a scanning electron microscopy. Results show that smaller PET particle sizes in lower concentrations generate improvements on compressive strength and strain, and Young’s modulus decreases when the size of PET particles used was increased.

  3. Attenuation correction for brain PET imaging using deep neural network based on dixon and ZTE MR images.

    Science.gov (United States)

    Gong, Kuang; Yang, Jaewon; Kim, Kyungsang; El Fakhri, Georges; Seo, Youngho; Li, Quanzheng

    2018-05-23

    Positron Emission Tomography (PET) is a functional imaging modality widely used in neuroscience studies. To obtain meaningful quantitative results from PET images, attenuation correction is necessary during image reconstruction. For PET/MR hybrid systems, PET attenuation is challenging as Magnetic Resonance (MR) images do not reflect attenuation coefficients directly. To address this issue, we present deep neural network methods to derive the continuous attenuation coefficients for brain PET imaging from MR images. With only Dixon MR images as the network input, the existing U-net structure was adopted and analysis using forty patient data sets shows it is superior than other Dixon based methods. When both Dixon and zero echo time (ZTE) images are available, we have proposed a modified U-net structure, named GroupU-net, to efficiently make use of both Dixon and ZTE information through group convolution modules when the network goes deeper. Quantitative analysis based on fourteen real patient data sets demonstrates that both network approaches can perform better than the standard methods, and the proposed network structure can further reduce the PET quantification error compared to the U-net structure. © 2018 Institute of Physics and Engineering in Medicine.

  4. Background based Gaussian mixture model lesion segmentation in PET

    Energy Technology Data Exchange (ETDEWEB)

    Soffientini, Chiara Dolores, E-mail: chiaradolores.soffientini@polimi.it; Baselli, Giuseppe [DEIB, Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133 (Italy); De Bernardi, Elisabetta [Department of Medicine and Surgery, Tecnomed Foundation, University of Milano—Bicocca, Monza 20900 (Italy); Zito, Felicia; Castellani, Massimo [Nuclear Medicine Department, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, via Francesco Sforza 35, Milan 20122 (Italy)

    2016-05-15

    Purpose: Quantitative {sup 18}F-fluorodeoxyglucose positron emission tomography is limited by the uncertainty in lesion delineation due to poor SNR, low resolution, and partial volume effects, subsequently impacting oncological assessment, treatment planning, and follow-up. The present work develops and validates a segmentation algorithm based on statistical clustering. The introduction of constraints based on background features and contiguity priors is expected to improve robustness vs clinical image characteristics such as lesion dimension, noise, and contrast level. Methods: An eight-class Gaussian mixture model (GMM) clustering algorithm was modified by constraining the mean and variance parameters of four background classes according to the previous analysis of a lesion-free background volume of interest (background modeling). Hence, expectation maximization operated only on the four classes dedicated to lesion detection. To favor the segmentation of connected objects, a further variant was introduced by inserting priors relevant to the classification of neighbors. The algorithm was applied to simulated datasets and acquired phantom data. Feasibility and robustness toward initialization were assessed on a clinical dataset manually contoured by two expert clinicians. Comparisons were performed with respect to a standard eight-class GMM algorithm and to four different state-of-the-art methods in terms of volume error (VE), Dice index, classification error (CE), and Hausdorff distance (HD). Results: The proposed GMM segmentation with background modeling outperformed standard GMM and all the other tested methods. Medians of accuracy indexes were VE <3%, Dice >0.88, CE <0.25, and HD <1.2 in simulations; VE <23%, Dice >0.74, CE <0.43, and HD <1.77 in phantom data. Robustness toward image statistic changes (±15%) was shown by the low index changes: <26% for VE, <17% for Dice, and <15% for CE. Finally, robustness toward the user-dependent volume initialization was

  5. Higher Dietary Choline and Betaine Intakes Are Associated with Better Body Composition in the Adult Population of Newfoundland, Canada.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available Choline is an essential nutrient and betaine is an osmolyte and methyl donor. Both are important to maintain health including adequate lipid metabolism. Supplementation of dietary choline and betaine increase muscle mass and reduce body fat in animals. However, little data is available regarding the role of dietary choline and betaine on body composition in humans.To investigate the association between dietary choline and betaine intakes with body composition in a large population based cross-sectional study.A total of 3214 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics study were assessed. Dietary choline and betaine intakes were computed from the Willett Food Frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses.Significantly inverse correlations were found between dietary choline and betaine intakes, with all obesity measurements: total percent body fat (%BF, percent trunk fat (%TF, percent android fat (%AF, percent gynoid fat (%GF and anthropometrics: weight, body mass index, waist circumference, waist-to-hip ratio in both women and men (r range from -0.13 to -0.47 for choline and -0.09 to -0.26 for betaine, p<0.001 for all. Dietary choline intake had stronger association than betaine. Moreover, obese subjects had the lowest dietary choline and betaine intakes, with overweight subjects in the middle, and normal weight subjects consumed the highest dietary choline and betaine (p<0.001. Vice versa, when subjects were ranked according to dietary choline and betaine intakes, subjects with the highest intake of both had the lowest %TF, %AF, %GF, %BF and highest %LM among the groups in both sexes.Our findings indicate that high dietary choline and betaine intakes are significantly associated with favorable body

  6. Full modelling of the MOSAIC animal PET system based on the GATE Monte Carlo simulation code

    International Nuclear Information System (INIS)

    Merheb, C; Petegnief, Y; Talbot, J N

    2007-01-01

    within 9%. For a 410-665 keV energy window, the measured sensitivity for a centred point source was 1.53% and mouse and rat scatter fractions were respectively 12.0% and 18.3%. The scattered photons produced outside the rat and mouse phantoms contributed to 24% and 36% of total simulated scattered coincidences. Simulated and measured single and prompt count rates agreed well for activities up to the electronic saturation at 110 MBq for the mouse and rat phantoms. Volumetric spatial resolution was 17.6 μL at the centre of the FOV with differences less than 6% between experimental and simulated spatial resolution values. The comprehensive evaluation of the Monte Carlo modelling of the Mosaic(TM) system demonstrates that the GATE package is adequately versatile and appropriate to accurately describe the response of an Anger logic based animal PET system

  7. Correlation between 11C-choline or 18F-FDG uptake and tumor proliferation: a rabbit bearing lung cancer model study

    International Nuclear Information System (INIS)

    Li Yajun; Bai Renju; Gao Shuo; Li Yansheng; Liu Lei; Jia Wei; Cai Li; Xing Xiling

    2009-01-01

    Objective: Tumor proliferative activity has been recognized as an indicator of malignant degree in lung cancer and related to prognosis. The purpose of this study was to evaluate the feasibility of assessing proliferative activity with 11 C-choline and 18 F-fluorodeoxyglucose (FDG) PET on a rabbit bearing lung VX2 tumor model. Methods: About 0.5 ml of viable VX2 tumor cell suspension was slowly injected into the right lungs of 54 New Zealand white rabbits through a transthoracical needle insertion. 11 C-choline and 18 F-FDG PET scan were performed 10-11 d after tumor implantation. One ear vein was cannulated for administration of the tracers, 11 C-choline PET scan (with Discovery LS PET/CT scanner, GE) was performed 5 rain after intravenously injection of 37 MBq 11 C-choline. Then 18.7 MBq 18 F-FDG was infused at 60 min after 11 C-choline administration and 18 F-FDG PET scan was performed at 60 min after 18 F-FDG administration. The maximal standardized uptake value of tumor was calculated. The animals were euthanized after examination. Histochemical stain with proliferating cell nuclear antigen (PCNA) was performed and PCNA index was obtained to assess tumor proliferation. The difference of 11 C-choline and 18 F-FDG was analyzed using paired student t-test. The correlation of 11 C-choline 18 F-FDG and tumor cell density and PCNA index was analyzed using Pearson linear regression. Results: Of the 54 rabbits, 36 had a solitary pulmonary tumor. The rate of successful generation of a solitary VX2 tumor was 66.7% (36/54). Only 33 rabbits underwent both 11 C-choline and 18 F-FDG PET, and enrolled in this study. The mean cellular density was (547.36 ± 64.78) cells/field and the mean PCNA index was (42.34 ± 15.26)%. 18 F-FDG was higher than 11 C-choline (5.70 ± 3.45 vs 4.02 ± 3.07, t=-3.188, P=0.003). 11 C-choline significantly and positively correlated with PCNA index (r=0.786, P 11 C-choline and tumor cellular density (r=-0.176, P=0.327). 18 F-FDG significantly and

  8. The Advantages of Human Milk Recognize the Spatiotemporal Locations of Toxins and Intelligently Bypass Them by Forming a Hummingbird-Like Hovering Neural Network Circuitry Based on an Organic Biomimetic Choline Acetyltransferase Memristor/Memcapacitor Prosthesis

    Directory of Open Access Journals (Sweden)

    E. T. CHEN

    2016-08-01

    Full Text Available We have demonstrated a unique approach to study human milk’s advantage in promoting and protecting infant early brain cognitive development by recognizing toxins and intelligently bypassing the toxin by forming high frequency oscillation (HFO in the brain circuitry when compared with organic cow milk samples based on an organic memristor/memcapacitor biomimetic Choline Acetyltransferase (CHAT neural network circuitry prosthesis along with a 3D Energy-sensory dynamic mapping method under antibody- free, radiolabeling-free, and reagent-less conditions. We also demonstrated cow milk is unfit for infant cognitive development, and it is actually harmful in terms of mutating infant brain synapse circuitry conformation, current flow direction, and energy output that lead to multiple Pathological High Frequency Oscillation (pHFO formations, and further, it led to sudden infant death syndrome (SIDS based on our prediction.

  9. History and current status of PET development based on time of flight

    International Nuclear Information System (INIS)

    Yun Mingkai; Li Ting; Zhang Zhiming; Zhang Yubao; Shan Baoci; Wei Long

    2012-01-01

    The principle of time of flight (TOF) positron emission tomography (PET) and a brief review of the history of TOF-PET are introduced. The factors influencing the time resolution of a TOF-PET scanner are presented, especially focus on the intrinsic properties of scintillators and front-end electronics. Challenges and achievements of the structure of data organization and image reconstruction are reviewed. Finally, the benefits of TOF-PET on image quality improvement and tumor detection are emphasized. (authors)

  10. Intestinal absorption of cytidine diphosphate choline and its changes in the digestive tract

    International Nuclear Information System (INIS)

    Yashima, Keisuke; Takamatsu, Masatoshi; Okuda, Kunio

    1975-01-01

    Intestinal absorption of cytidine diphosphate choline (CDP-choline), its structural changes in the digestive tract, and hepatic uptake have been investigated in rats using 14 C-labeled ( 14 CH 3 attached to N of choline) and 3 H-labeled (at C 5 of pyrimidine) compounds. The results indicate that: 1) CDP-choline is relatively stable in the stomach, but is quickly degraded into cytidine and choline in the intestine; 2) The hepatic uptakes of 14 C and 3 H reach the maximum in two to three hours after oral administration; 3) Whereas the amount of 14 C remaining in the gut is inversely related to the hepatic uptake, no similar correlation is seen with 3 H-labeled CDP-choline, and 4) Extrahepatic uptake of 14 C and 3 H is very small. The possibility of phosphorylation in the mucosa of choline and cytidine has been discussed, based on the differences in relative amount of radioactivity in individual broken-down products in the intestinal lumen and mucosa. (auth.)

  11. Dietary Intake and Plasma Levels of Choline and Betaine in Children with Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Joanna C. Hamlin

    2013-01-01

    Full Text Available Abnormalities in folate-dependent one-carbon metabolism have been reported in many children with autism. Because inadequate choline and betaine can negatively affect folate metabolism and in turn downstream methylation and antioxidant capacity, we sought to determine whether dietary intake of choline and betaine in children with autism was adequate to meet nutritional needs based on national recommendations. Three-day food records were analyzed for 288 children with autism (ASDs who participated in the national Autism Intervention Research Network for Physical Health (AIR-P Study on Diet and Nutrition in children with autism. Plasma concentrations of choline and betaine were measured in a subgroup of 35 children with ASDs and 32 age-matched control children. The results indicated that 60–93% of children with ASDs were consuming less than the recommended Adequate Intake (AI for choline. Strong positive correlations were found between dietary intake and plasma concentrations of choline and betaine in autistic children as well as lower plasma concentrations compared to the control group. We conclude that choline and betaine intake is inadequate in a significant subgroup of children with ASDs and is reflected in lower plasma levels. Inadequate intake of choline and betaine may contribute to the metabolic abnormalities observed in many children with autism and warrants attention in nutritional counseling.

  12. Anatomically guided voxel-based partial volume effect correction in brain PET : Impact of MRI segmentation

    NARCIS (Netherlands)

    Gutierrez, Daniel; Montandon, Marie-Louise; Assal, Frederic; Allaoua, Mohamed; Ratib, Osman; Loevblad, Karl-Olof; Zaidi, Habib

    2012-01-01

    Partial volume effect is still considered one of the main limitations in brain PET imaging given the limited spatial resolution of current generation PET scanners. The accuracy of anatomically guided partial volume effect correction (PVC) algorithms in brain PET is largely dependent on the

  13. Outcome after PSMA PET/CT based radiotherapy in patients with biochemical persistence or recurrence after radical prostatectomy.

    Science.gov (United States)

    Schmidt-Hegemann, Nina-Sophie; Fendler, Wolfgang Peter; Ilhan, Harun; Herlemann, Annika; Buchner, Alexander; Stief, Christian; Eze, Chukwuka; Rogowski, Paul; Li, Minglun; Bartenstein, Peter; Ganswindt, Ute; Belka, Claus

    2018-03-02

    PSMA PET/CT visualises prostate cancer residual disease or recurrence at lower PSA levels compared to conventional imaging and results in a change of treatment in a remarkable high number of patients. Radiotherapy with dose escalation to the former prostate bed has been associated with improved biochemical recurrence-free survival. Thus, it can be hypothesised that PSMA PET/CT-based radiotherapy might improve the prognosis of these patients. One hundred twenty-nine patients underwent PSMA PET/CT due to biochemical persistence (52%) or recurrence (48%) after radical prostatectomy without evidence of distant metastases (February 2014-May 2017) and received PSMA PET/CT-based radiotherapy. Biochemical recurrence free survival (PSA ≤ 0.2 ng/ml) was defined as the study endpoint. Patients with biochemical persistence were significantly more often high-risk patients with significantly shorter time interval before PSMA PET/CT than patients with biochemical recurrence. Patients with biochemical recurrence had significantly more often no evidence of disease or local recurrence only in PSMA PET/CT, whereas patients with biochemical persistence had significantly more often lymph node involvement. Seventy-three patients were started on antiandrogen therapy prior to radiotherapy due to macroscopic disease in PSMA PET/CT. Cumulatively, 70 (66-70.6) Gy was delivered to local macroscopic tumor, 66 (63-66) Gy to the prostate fossa, 61.6 (53.2-66) Gy to PET-positive lymph nodes and 50.4 (45-52.3) Gy to lymphatic pathways. Median PSA after radiotherapy was 0.07 ng/ml with 74% of patients having a PSA ≤ 0.1 ng/ml. After a median follow-up of 20 months, median PSA was 0.07 ng/ml with ongoing antiandrogen therapy in 30 patients. PET-positive patients without antiandrogen therapy at last follow-up (45 patients) had a median PSA of 0.05 ng/ml with 89% of all patients, 94% of patients with biochemical recurrence and 82% of patients with biochemical persistence having a

  14. Accuracy and Radiation Dose of CT-Based Attenuation Correction for Small Animal PET: A Monte Carlo Simulation Study

    International Nuclear Information System (INIS)

    Yang, Ching-Ching; Chan, Kai-Chieh

    2013-06-01

    -Small animal PET allows qualitative assessment and quantitative measurement of biochemical processes in vivo, but the accuracy and reproducibility of imaging results can be affected by several parameters. The first aim of this study was to investigate the performance of different CT-based attenuation correction strategies and assess the resulting impact on PET images. The absorbed dose in different tissues caused by scanning procedures was also discussed to minimize biologic damage generated by radiation exposure due to PET/CT scanning. A small animal PET/CT system was modeled based on Monte Carlo simulation to generate imaging results and dose distribution. Three energy mapping methods, including the bilinear scaling method, the dual-energy method and the hybrid method which combines the kVp conversion and the dual-energy method, were investigated comparatively through assessing the accuracy of estimating linear attenuation coefficient at 511 keV and the bias introduced into PET quantification results due to CT-based attenuation correction. Our results showed that the hybrid method outperformed the bilinear scaling method, while the dual-energy method achieved the highest accuracy among the three energy mapping methods. Overall, the accuracy of PET quantification results have similar trend as that for the estimation of linear attenuation coefficients, whereas the differences between the three methods are more obvious in the estimation of linear attenuation coefficients than in the PET quantification results. With regards to radiation exposure from CT, the absorbed dose ranged between 7.29-45.58 mGy for 50-kVp scan and between 6.61-39.28 mGy for 80-kVp scan. For 18 F radioactivity concentration of 1.86x10 5 Bq/ml, the PET absorbed dose was around 24 cGy for tumor with a target-to-background ratio of 8. The radiation levels for CT scans are not lethal to the animal, but concurrent use of PET in longitudinal study can increase the risk of biological effects. The

  15. 21 CFR 182.8252 - Choline chloride.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Choline chloride. 182.8252 Section 182.8252 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... chloride. (a) Product. Choline chloride. (b) Conditions of use. This substance is generally recognized as...

  16. Choline Theft-An Inside Job.

    Science.gov (United States)

    Mora-Ortiz, Marina; Claus, Sandrine Paule

    2017-09-13

    Choline is a crucial methyl donor necessary for epigenetic regulation. In this issue of Cell Host & Microbe, Romano et al. (2017) demonstrate that choline-utilizing gut bacteria compete with their host for this essential resource, calling for a systematic consideration of gut microbial composition for personalized diet recommendations. Copyright © 2017. Published by Elsevier Inc.

  17. Pilot tests of a PET detector using the TOF-PET ASIC based on monolithic crystals and SiPMs

    International Nuclear Information System (INIS)

    Aguilar, A.; González-Montoro, A.; González, A.J.; Hernández, L.; Monzó, J.M.; Benlloch, J.M.; Bugalho, R.; Ferramacho, L.

    2016-01-01

    In this work we show pilot tests of PET detector blocks using the TOF-PET ASIC, coupled to SiPM detector arrays and different crystal configurations. We have characterized the main ASIC features running calibration processes to compensate the time dispersion among the different ASIC/SiPM paths as well as for the time walk on the arrival of optical photons. The aim of this work is to use of LYSO monolithic crystals and explore their photon Depth of Interaction (DOI) capabilities, keeping good energy and spatial resolutions. First tests have been carried out with crystal arrays. Here we made it possible to reach a coincidence resolving times (CRT) of 370 ps FWHM, with energy resolutions better than 20% and resolving well 2 mm sized crystal elements. When using monolithic crystals, a single-pixel LYSO reference crystal helped to explore the CRT performance. We studied different strategies to provide the best timestamp determination in the monolithic scintillator. Times around 1 ns FWHM have been achieved in these pilot studies. In terms of spatial and energy resolution, values of about 3 mm and better than 30% were found, respectively. We have also demonstrated the capability of this system (monolithic and ASIC) to return accurate DOI information.

  18. Factors influencing erythrocyte choline concentrations.

    Science.gov (United States)

    Miller, B L; Jenden, D J; Tang, C; Read, S

    1989-01-01

    Choline concentrations in human erythrocytes increase after freezing and thawing, during incubation in Krebs-phosphate for 30 min or on storage at 0 degrees C for 3-24 hr. The increase is prevented by protein precipitation by 10% perchloric acid, 10% zinc hydroxide, 10% sodium tungstate or boiling in water. It is not prevented by EDTA (10 mM) and is increased by oleate (5 mM). We suggest that the increase is due to the action of phospholipase D on erythrocyte phospholipids.

  19. A Time-Based Front End Readout System for PET & CT

    CERN Document Server

    Meyer, T C; Anghinolfi, F; Auffray, E; Dosanjh, M; Hillemanns, H; Hoffmann, H -F; Jarron, P; Kaplon, J; Kronberger, M; Lecoq, P; Moraes, D; Trummer, J

    2007-01-01

    In the framework of the European FP6's BioCare project, we develop a novel, time-based, photo-detector readout technique to increase sensitivity and timing precision for molecular imaging in PET and CT. The project aims to employ Avalanche Photo Diode (APD) arrays with state of the art, high speed, front end amplifiers and discrimination circuits developed for the Large Hadron Collider (LHC) physics program at CERN, suitable to detect and process photons in a combined one-unit PET/CT detection head. In the so-called time-based approach our efforts focus on the system's timing performance with sub-nanosecond time-jitter and -walk, and yet also provide information on photon energy without resorting to analog to digital conversion. The bandwidth of the electronic circuitry is compatible with the scintillator's intrinsic light response (e.g. les40ns in LSO) and hence allows high rate CT operation in single-photon counting mode. Based on commercial LSO crystals and Hamamatsu S8550 APD arrays, we show the system pe...

  20. A scheme for PET data normalization in event-based motion correction

    International Nuclear Information System (INIS)

    Zhou, Victor W; Kyme, Andre Z; Fulton, Roger; Meikle, Steven R

    2009-01-01

    Line of response (LOR) rebinning is an event-based motion-correction technique for positron emission tomography (PET) imaging that has been shown to compensate effectively for rigid motion. It involves the spatial transformation of LORs to compensate for motion during the scan, as measured by a motion tracking system. Each motion-corrected event is then recorded in the sinogram bin corresponding to the transformed LOR. It has been shown previously that the corrected event must be normalized using a normalization factor derived from the original LOR, that is, based on the pair of detectors involved in the original coincidence event. In general, due to data compression strategies (mashing), sinogram bins record events detected on multiple LORs. The number of LORs associated with a sinogram bin determines the relative contribution of each LOR. This paper provides a thorough treatment of event-based normalization during motion correction of PET data using LOR rebinning. We demonstrate theoretically and experimentally that normalization of the corrected event during LOR rebinning should account for the number of LORs contributing to the sinogram bin into which the motion-corrected event is binned. Failure to account for this factor may cause artifactual slice-to-slice count variations in the transverse slices and visible horizontal stripe artifacts in the coronal and sagittal slices of the reconstructed images. The theory and implementation of normalization in conjunction with the LOR rebinning technique is described in detail, and experimental verification of the proposed normalization method in phantom studies is presented.

  1. Textural features and SUV-based variables assessed by dual time point 18F-FDG PET/CT in locally advanced breast cancer.

    Science.gov (United States)

    Garcia-Vicente, Ana María; Molina, David; Pérez-Beteta, Julián; Amo-Salas, Mariano; Martínez-González, Alicia; Bueno, Gloria; Tello-Galán, María Jesús; Soriano-Castrejón, Ángel

    2017-12-01

    To study the influence of dual time point 18F-FDG PET/CT in textural features and SUV-based variables and their relation among them. Fifty-six patients with locally advanced breast cancer (LABC) were prospectively included. All of them underwent a standard 18F-FDG PET/CT (PET-1) and a delayed acquisition (PET-2). After segmentation, SUV variables (SUVmax, SUVmean, and SUVpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were obtained. Eighteen three-dimensional (3D) textural measures were computed including: run-length matrices (RLM) features, co-occurrence matrices (CM) features, and energies. Differences between all PET-derived variables obtained in PET-1 and PET-2 were studied. Significant differences were found between the SUV-based parameters and MTV obtained in the dual time point PET/CT, with higher values of SUV-based variables and lower MTV in the PET-2 with respect to the PET-1. In relation with the textural parameters obtained in dual time point acquisition, significant differences were found for the short run emphasis, low gray-level run emphasis, short run high gray-level emphasis, run percentage, long run emphasis, gray-level non-uniformity, homogeneity, and dissimilarity. Textural variables showed relations with MTV and TLG. Significant differences of textural features were found in dual time point 18F-FDG PET/CT. Thus, a dynamic behavior of metabolic characteristics should be expected, with higher heterogeneity in delayed PET acquisition compared with the standard PET. A greater heterogeneity was found in bigger tumors.

  2. Interaction between cytotoxic effects of γ-radiation and folate deficiency in relation to choline reserves

    International Nuclear Information System (INIS)

    Batra, Vipen; Devasagayam, Thomas Paul Asir

    2009-01-01

    The search for non-toxic radio-protective drugs has yielded many potential agents but most of these compounds have certain amount of toxicity. Recent studies have indicated that bio-molecules such as folate and choline might be of radio-protective value as they are, within broad dose ranges, non-toxic to humans and experimental animals. The objective of the present study was to investigate choline dependent adaptive response to potential synergistic cytotoxic effect of folate deficiency and γ-radiation. Male Swiss mice maintained on folate sufficient diet (FSD) and folate free diet (FFD) based on AIN-93 M formula, were subjected to 1-4 Gy total body γ-irradiation. To investigate liver DNA damage, apurinic/apyrimidinic sites (AP sites) were quantified. A significant increase in liver DNA AP sites with concomitant depletion of liver choline reserves was observed when γ-radiation was combined with folate deficiency. Further work in this direction suggested that cytotoxic interaction between folate deficiency and gamma radiation might induce utilization of choline and choline containing moieties by modifying levels of key regulatory enzymes dihydrofolate reductase (DHFR) and choline oxidase (ChoOx). Another major finding of these studies is that significant liver damage at higher doses of radiation (3-4 Gy), might release considerable amounts of choline reserves to serum. In conclusion, a plausible interpretation of the present studies is that folate deprivation and γ-radiation interact to mobilize additional choline reserves of hepatic tissue, for redistribution to other organs, which could not be utilized by folate deficiency alone. Present results clearly indicated a distinct choline pool in liver and kidney tissues that could be utilized by folate deficient animals only under radiation stress conditions

  3. A gradient-based method for segmenting FDG-PET images: methodology and validation

    International Nuclear Information System (INIS)

    Geets, Xavier; Lee, John A.; Gregoire, Vincent; Bol, Anne; Lonneux, Max

    2007-01-01

    A new gradient-based method for segmenting FDG-PET images is described and validated. The proposed method relies on the watershed transform and hierarchical cluster analysis. To allow a better estimation of the gradient intensity, iteratively reconstructed images were first denoised and deblurred with an edge-preserving filter and a constrained iterative deconvolution algorithm. Validation was first performed on computer-generated 3D phantoms containing spheres, then on a real cylindrical Lucite phantom containing spheres of different volumes ranging from 2.1 to 92.9 ml. Moreover, laryngeal tumours from seven patients were segmented on PET images acquired before laryngectomy by the gradient-based method and the thresholding method based on the source-to-background ratio developed by Daisne (Radiother Oncol 2003;69:247-50). For the spheres, the calculated volumes and radii were compared with the known values; for laryngeal tumours, the volumes were compared with the macroscopic specimens. Volume mismatches were also analysed. On computer-generated phantoms, the deconvolution algorithm decreased the mis-estimate of volumes and radii. For the Lucite phantom, the gradient-based method led to a slight underestimation of sphere volumes (by 10-20%), corresponding to negligible radius differences (0.5-1.1 mm); for laryngeal tumours, the segmented volumes by the gradient-based method agreed with those delineated on the macroscopic specimens, whereas the threshold-based method overestimated the true volume by 68% (p = 0.014). Lastly, macroscopic laryngeal specimens were totally encompassed by neither the threshold-based nor the gradient-based volumes. The gradient-based segmentation method applied on denoised and deblurred images proved to be more accurate than the source-to-background ratio method. (orig.)

  4. A Registration Method Based on Contour Point Cloud for 3D Whole-Body PET and CT Images

    Directory of Open Access Journals (Sweden)

    Zhiying Song

    2017-01-01

    Full Text Available The PET and CT fusion image, combining the anatomical and functional information, has important clinical meaning. An effective registration of PET and CT images is the basis of image fusion. This paper presents a multithread registration method based on contour point cloud for 3D whole-body PET and CT images. Firstly, a geometric feature-based segmentation (GFS method and a dynamic threshold denoising (DTD method are creatively proposed to preprocess CT and PET images, respectively. Next, a new automated trunk slices extraction method is presented for extracting feature point clouds. Finally, the multithread Iterative Closet Point is adopted to drive an affine transform. We compare our method with a multiresolution registration method based on Mattes Mutual Information on 13 pairs (246~286 slices per pair of 3D whole-body PET and CT data. Experimental results demonstrate the registration effectiveness of our method with lower negative normalization correlation (NC = −0.933 on feature images and less Euclidean distance error (ED = 2.826 on landmark points, outperforming the source data (NC = −0.496, ED = 25.847 and the compared method (NC = −0.614, ED = 16.085. Moreover, our method is about ten times faster than the compared one.

  5. Impacts of Intelligent Automated Quality Control on a Small Animal APD-Based Digital PET Scanner

    Science.gov (United States)

    Charest, Jonathan; Beaudoin, Jean-François; Bergeron, Mélanie; Cadorette, Jules; Arpin, Louis; Lecomte, Roger; Brunet, Charles-Antoine; Fontaine, Réjean

    2016-10-01

    Stable system performance is mandatory to warrant the accuracy and reliability of biological results relying on small animal positron emission tomography (PET) imaging studies. This simple requirement sets the ground for imposing routine quality control (QC) procedures to keep PET scanners at a reliable optimal performance level. However, such procedures can become burdensome to implement for scanner operators, especially taking into account the increasing number of data acquisition channels in newer generation PET scanners. In systems using pixel detectors to achieve enhanced spatial resolution and contrast-to-noise ratio (CNR), the QC workload rapidly increases to unmanageable levels due to the number of independent channels involved. An artificial intelligence based QC system, referred to as Scanner Intelligent Diagnosis for Optimal Performance (SIDOP), was proposed to help reducing the QC workload by performing automatic channel fault detection and diagnosis. SIDOP consists of four high-level modules that employ machine learning methods to perform their tasks: Parameter Extraction, Channel Fault Detection, Fault Prioritization, and Fault Diagnosis. Ultimately, SIDOP submits a prioritized faulty channel list to the operator and proposes actions to correct them. To validate that SIDOP can perform QC procedures adequately, it was deployed on a LabPET™ scanner and multiple performance metrics were extracted. After multiple corrections on sub-optimal scanner settings, a 8.5% (with a 95% confidence interval (CI) of [7.6, 9.3]) improvement in the CNR, a 17.0% (CI: [15.3, 18.7]) decrease of the uniformity percentage standard deviation, and a 6.8% gain in global sensitivity were observed. These results confirm that SIDOP can indeed be of assistance in performing QC procedures and restore performance to optimal figures.

  6. Automated lung tumor segmentation for whole body PET volume based on novel downhill region growing

    Science.gov (United States)

    Ballangan, Cherry; Wang, Xiuying; Eberl, Stefan; Fulham, Michael; Feng, Dagan

    2010-03-01

    We propose an automated lung tumor segmentation method for whole body PET images based on a novel downhill region growing (DRG) technique, which regards homogeneous tumor hotspots as 3D monotonically decreasing functions. The method has three major steps: thoracic slice extraction with K-means clustering of the slice features; hotspot segmentation with DRG; and decision tree analysis based hotspot classification. To overcome the common problem of leakage into adjacent hotspots in automated lung tumor segmentation, DRG employs the tumors' SUV monotonicity features. DRG also uses gradient magnitude of tumors' SUV to improve tumor boundary definition. We used 14 PET volumes from patients with primary NSCLC for validation. The thoracic region extraction step achieved good and consistent results for all patients despite marked differences in size and shape of the lungs and the presence of large tumors. The DRG technique was able to avoid the problem of leakage into adjacent hotspots and produced a volumetric overlap fraction of 0.61 +/- 0.13 which outperformed four other methods where the overlap fraction varied from 0.40 +/- 0.24 to 0.59 +/- 0.14. Of the 18 tumors in 14 NSCLC studies, 15 lesions were classified correctly, 2 were false negative and 15 were false positive.

  7. New component-based normalization method to correct PET system models

    International Nuclear Information System (INIS)

    Kinouchi, Shoko; Miyoshi, Yuji; Suga, Mikio; Yamaya, Taiga; Yoshida, Eiji; Nishikido, Fumihiko; Tashima, Hideaki

    2011-01-01

    Normalization correction is necessary to obtain high-quality reconstructed images in positron emission tomography (PET). There are two basic types of normalization methods: the direct method and component-based methods. The former method suffers from the problem that a huge count number in the blank scan data is required. Therefore, the latter methods have been proposed to obtain high statistical accuracy normalization coefficients with a small count number in the blank scan data. In iterative image reconstruction methods, on the other hand, the quality of the obtained reconstructed images depends on the system modeling accuracy. Therefore, the normalization weighing approach, in which normalization coefficients are directly applied to the system matrix instead of a sinogram, has been proposed. In this paper, we propose a new component-based normalization method to correct system model accuracy. In the proposed method, two components are defined and are calculated iteratively in such a way as to minimize errors of system modeling. To compare the proposed method and the direct method, we applied both methods to our small OpenPET prototype system. We achieved acceptable statistical accuracy of normalization coefficients while reducing the count number of the blank scan data to one-fortieth that required in the direct method. (author)

  8. Dental artifacts in the head and neck region: implications for Dixon-based attenuation correction in PET/MR

    Energy Technology Data Exchange (ETDEWEB)

    Ladefoged, Claes N; Hansen, Adam E; Keller, Sune H; Fischer, Barbara M [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen East (Denmark); Rasmussen, Jacob H [Department of Oncology, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen East (Denmark); Law, Ian; Kjær, Andreas; Højgaard, Liselotte [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen East (Denmark); Lauze, Francois [Department of Computer Science, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen East (Denmark); Beyer, Thomas [Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, Vienna, A-1090 (Austria); Andersen, Flemming L [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen East (Denmark)

    2015-03-11

    In the absence of CT or traditional transmission sources in combined clinical positron emission tomography/magnetic resonance (PET/MR) systems, MR images are used for MR-based attenuation correction (MR-AC). The susceptibility effects due to metal implants challenge MR-AC in the neck region of patients with dental implants. The purpose of this study was to assess the frequency and magnitude of subsequent PET image distortions following MR-AC. A total of 148 PET/MR patients with clear visual signal voids on the attenuation map in the dental region were included in this study. Patients were injected with [{sup 18}F]-FDG, [{sup 11}C]-PiB, [{sup 18}F]-FET, or [{sup 64}Cu]-DOTATATE. The PET/MR data were acquired over a single-bed position of 25.8 cm covering the head and neck. MR-AC was based on either standard MR-AC{sub DIXON} or MR-AC{sub INPAINTED} where the susceptibility-induced signal voids were substituted with soft tissue information. Our inpainting algorithm delineates the outer contour of signal voids breaching the anatomical volume using the non-attenuation-corrected PET image and classifies the inner air regions based on an aligned template of likely dental artifact areas. The reconstructed PET images were evaluated visually and quantitatively using regions of interests in reference regions. The volume of the artifacts and the computed relative differences in mean and max standardized uptake value (SUV) between the two PET images are reported. The MR-based volume of the susceptibility-induced signal voids on the MR-AC attenuation maps was between 1.6 and 520.8 mL. The corresponding/resulting bias of the reconstructed tracer distribution was localized mainly in the area of the signal void. The mean and maximum SUVs averaged across all patients increased after inpainting by 52% (± 11%) and 28% (± 11%), respectively, in the corrected region. SUV underestimation decreased with the distance to the signal void and correlated with the volume of the susceptibility

  9. Radiation exposure during transmission measurements: comparison between CT- and germanium-based techniques with a current PET scanner

    International Nuclear Information System (INIS)

    Wu, Tung-Hsin; Huang, Yung-Hui; Lee, Jason J.S.; Wang, Shih-Yuan; Wang, Su-Cheng; Su, Cheng-Tau; Chen, Liang-Kung; Chu, Tieh-Chi

    2004-01-01

    In positron emission tomographic (PET) scanning, transmission measurements for attenuation correction are commonly performed by using external germanium-68 rod sources. Recently, combined PET and computed tomographic (CT) scanners have been developed in which the CT data can be used for both anatomical-metabolic image formation and attenuation correction of the PET data. The purpose of this study was to evaluate the difference between germanium- and CT-based transmission scanning in terms of their radiation doses by using the same measurement technique and to compare the doses that patients receive during brain, cardiac and whole-body scans. Measurement of absorbed doses to organs was conducted by using a Rando Alderson phantom with thermoluminescent dosimeters. Effective doses were calculated according to the guidelines in the International Commission on Radiation Protection Publication Number 60. Compared with radionuclide doses used in routine 2-[fluorine-18]-fluoro-2-deoxy-d-glucose PET imaging, doses absorbed during germanium-based transmission scans were almost negligible. On the other hand, absorbed doses from CT-based transmission scans were significantly higher, particularly with a whole-body scanning protocol. Effective doses were 8.81 mSv in the high-speed mode and 18.97 mSv in the high-quality mode for whole-body CT-based transmission scans. These measurements revealed that the doses received by a patient during CT-based transmission scanning are more than those received in a typical PET examination. Therefore, the radiation doses represent a limitation to the generalised use of CT-based transmission measurements with current PET/CT scanner systems. (orig.)

  10. Localization of Epileptogenic Zones using Partical Volume Corrected FDG Uptake on FDG PET and Voxel Based Morphometry on MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Won Jun; Lee, Ho Young; Lee, Jae Sung; Lee, Dong Soo; Lee, Sang Kun; Chung, June Key; Lee, Myung Chul [College of Medicine, Univ. of Seoul National, Seoul (Korea, Republic of)

    2003-07-01

    Partial volume corrected (PVC) FDG uptake yields information about regional metabolic level void of volume change, and voxel based morphometry (VBM) yields objective information regarding gray matter concentration. We investigated the roles of PVC PET and VBM to localize epileptogenic zones in medial temporal lobe epilepsy (mTLE) and non-lesional neocortical epilepsy. As a control group for PVC, 40 normal volunteers without history of neurologic or psychiatric diseases underwent FDG PET and MRI. Seventeen mTLE patients (M: F=7: 10, age=309 y) and nine neocortical epilepsy patients (M: F=6: 3, age=246, lateral temporal: 5, frontal: 3, occipital: 1) confirmed by surgery or epilepsy board meeting were enrolled. Standard VBM analysis was performed using individual MRI images compared with those of age-matched controls. For PVC, FDG PET was co-registered with its own MRI. PVC PET was obtained by dividing spillover-corrected PET by smoothed gray matter image pixel by pixel. SPAM was applied as a mask of volume of interest (VOI) to calculate gyral FDG uptake on PVC-FDG PET. Hippocampus, amygdala, superior, middle, inferior temporal gyrus and parahippocampal gyrus were the gyral SPAM VOIs in mTLE. Globally normalized PVC-FDG counts were compared with those of age-matched controls in mTLE and neocortical epilepsy patients. In mTlE, PVC-FDG PET correctly localized epileptogenic zones with the accuracy of 76% (13/17) in hippocampus and 82% (14/17) in any of six regions. VBM correctly localized 59% (10/17) in mTLE. In neocortical epilepsy, PVC-FDG PET localized epileptogenic zones in 44%, and VBM in 33%, Using VBM and PVC-FDG PET altogether, epileptogenic zones were localized in 66% (6/9). In mTLE, gyral PVC FDG uptake of temporal lobes was useful in localizing epileptogenic zones by demonstrating partial volume-void FDG concentration. In non-lesional cryptogenic neocortical epilepsy, combination of PVC-FDG PET and VBM is recommended to localize epileptogenic zones.

  11. 18F-FDG PET/CT in breast cancer: Evidence-based recommendations in initial staging.

    Science.gov (United States)

    Caresia Aroztegui, Ana Paula; García Vicente, Ana María; Alvarez Ruiz, Soledad; Delgado Bolton, Roberto Carlos; Orcajo Rincon, Javier; Garcia Garzon, Jose Ramon; de Arcocha Torres, Maria; Garcia-Velloso, Maria Jose

    2017-10-01

    Current guidelines do not systematically recommend 18F-FDG PET/CT for breast cancer staging; and the recommendations and level of evidence supporting its use in different groups of patients vary among guidelines. This review summarizes the evidence about the role of 18F-FDG PET/CT in breast cancer staging and the therapeutic and prognostic impact accumulated in the last decade. Other related aspects, such as the association of metabolic information with biology and prognosis are considered and evidence-based recommendations for the use of 18F-FDG PET/CT in breast cancer staging are offered. We systematically searched MEDLINE for articles reporting studies with at least 30 patients related to clinical questions following the Problem/Population, Intervention, Comparison, and Outcome framework. We critically reviewed the selected articles and elaborated evidence tables structuring the summarized information into methodology, results, and limitations. The level of evidence and the grades of recommendation for the use of 18F-FDG PET/CT in different contexts are summarized. Level III evidence supports the use of 18F-FDG PET/CT for initial staging in patients with recently diagnosed breast cancer; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a weak recommendation in this population. In patients with locally advanced breast cancer, level II evidence supports the use of 18F-FDG PET/CT for initial staging; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a strong recommendation in this population. In patients with recently diagnosed breast cancer, the metabolic information from baseline 18F-FDG PET/CT is associated with tumor biology and has prognostic implications, supported by level II evidence. In conclusion, 18F-FDG PET/CT is not recommended for staging all patients with early breast cancer, although evidence of improved regional and systemic staging supports its use in locally advanced

  12. Comparability of Computer-based and Paper-based Versions of Writing Section of PET in Iranian EFL Context

    Directory of Open Access Journals (Sweden)

    Mohammad Mohammadi

    2010-11-01

    Full Text Available Computer technology has provided language testing experts with opportunity to develop computerized versions of traditional paper-based language tests. New generations of TOEFL and Cambridge IELTS, BULATS, KET, PET are good examples of computer-based language tests. Since this new method of testing introduces new factors into the realm of language assessment ( e.g. modes of test delivery, familiarity with computer, etc.,the question may be whether the two modes of computer- and paper-based tests comparably measure the same construct, and hence, the scores obtained from the two modes can be used interchangeably. Accordingly, the present study aimed to investigate the comparability of the paper- and computer-based versions of a writing test. The data for this study were collected from administering the writing section of a Cambridge Preliminary English Test (PET to eighty Iranian intermediate EFL learners through the two modes of computer- and paper-based testing. Besides, a computer familiarity questionnaire was used to divide participants into two groups with high and low computer familiarity. The results of the independent samples t-test revealed that there was no statistically significant difference between the learners' computer- and paper-based writing scores. The results of the paired samples t-test showed no statistically significant difference between high- and low-computer-familiar groups on computer-based writing. The researchers concluded that the two modes comparably measured the same construct.

  13. A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

    International Nuclear Information System (INIS)

    Kaminska, D.; Gajos, A.; Czerwinski, E.; Alfs, D.; Bednarski, T.; Bialas, P.; Dulski, K.; Glowacz, B.; Gupta-Sharma, N.; Korcyl, G.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedzwiecki, Sz.; Pawlik-Niedzwiecka, M.; Rudy, Z.; Wieczorek, A.; Zielinski, M.; Moskal, P.; Curceanu, C.; Silarski, M.; Gorgol, M.; Jasinska, B.; Zgardzinska, B.; Hiesmayr, B.C.; Kowalski, P.; Raczynski, L.; Wislicki, W.; Krzemien, W.

    2016-01-01

    We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps → 3γ decays with angular and energy resolution equal to σ(θ) ∼ 0.4 circle and σ(E) ∼ 4.1 keV, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities. (orig.)

  14. A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Kaminska, D.; Gajos, A.; Czerwinski, E.; Alfs, D.; Bednarski, T.; Bialas, P.; Dulski, K.; Glowacz, B.; Gupta-Sharma, N.; Korcyl, G.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedzwiecki, Sz.; Pawlik-Niedzwiecka, M.; Rudy, Z.; Wieczorek, A.; Zielinski, M.; Moskal, P. [Jagiellonian University, Faculty of Physics, Astronomy and Applied Computer Science, Krakow (Poland); Curceanu, C.; Silarski, M. [INFN, Laboratori Nazionali di Frascati, CP 13, Frascati (Italy); Gorgol, M.; Jasinska, B.; Zgardzinska, B. [Maria Curie-Sklodowska University, Department of Nuclear Methods, Institute of Physics, Lublin (Poland); Hiesmayr, B.C. [University of Vienna, Faculty of Physics, Vienna (Austria); Kowalski, P.; Raczynski, L.; Wislicki, W. [Swierk Computing Centre, National Centre for Nuclear Research, Otwock-Swierk (Poland); Krzemien, W. [National Centre for Nuclear Research, High Energy Department, Otwock-Swierk (Poland)

    2016-08-15

    We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps → 3γ decays with angular and energy resolution equal to σ(θ) ∼ 0.4 {sup circle} and σ(E) ∼ 4.1 keV, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities. (orig.)

  15. A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

    Science.gov (United States)

    Kamińska, D.; Gajos, A.; Czerwiński, E.; Alfs, D.; Bednarski, T.; Białas, P.; Curceanu, C.; Dulski, K.; Głowacz, B.; Gupta-Sharma, N.; Gorgol, M.; Hiesmayr, B. C.; Jasińska, B.; Korcyl, G.; Kowalski, P.; Krzemień, W.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz.; Pawlik-Niedźwiecka, M.; Raczyński, L.; Rudy, Z.; Silarski, M.; Wieczorek, A.; Wiślicki, W.; Zgardzińska, B.; Zieliński, M.; Moskal, P.

    2016-08-01

    We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the { o-Ps }→ 3γ decays with angular and energy resolution equal to σ (θ ) ≈ {0.4°} and σ (E) ≈ 4.1 {keV}, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.

  16. Comparison of CT and integrated PET-CT based radiation therapy planning in patients with malignant pleural mesothelioma

    International Nuclear Information System (INIS)

    Pehlivan, Berrin; Topkan, Erkan; Onal, Cem; Nursal, Gul Nihal; Yuksel, Oznur; Dolek, Yemliha; Yavuz, Melek Nur; Yavuz, Ali Aydin

    2009-01-01

    When combined with adequate tumoricidal doses, accurate target volume delineation remains to be the one of the most important predictive factors for radiotherapy (RT) success in locally advanced or medically inoperable malignant pleural mesothelioma (MPM) patients. Recently, 18-fluorodeoxyglucose positron emission tomography (PET) has demonstrated significant improvements in diagnosis and accurate staging of MPM. However, role of additional PET data has not been studied in RT planning (RTP) of patients with inoperable MPM or in those who refuse surgery. Therefore, we planned to compare CT with co-registered PET-CT as the basis for delineating target volumes in these patients group. Retrospectively, the CT and co-registered PET-CT data of 13 patients with histologically proven MPM were utilized to delineate target volumes separately. For each patient, target volumes (gross tumor volume [GTV], clinical target volume [CTV], and planning target volume [PTV]) were defined using the CT and PET-CT fusion data sets. The PTV was measured in two ways: PTV1 was CTV plus a 1-cm margin, and PTV2 was GTV plus a 1-cm margin. We analyzed differences in target volumes. In 12 of 13 patients, compared to CT-based delineation, PET-CT-based delineation resulted in a statistically significant decrease in the mean GTV, CTV, PTV1, and PTV2. In these 12 patients, mean GTV decreased by 47.1% ± 28.4%, mean CTV decreased by 38.7% ± 24.7%, mean PTV1 decreased by 31.1% ± 23.1%, and mean PTV2 decreased by 40.0% ± 24.0%. In 4 of 13 patients, hilar lymph nodes were identified by PET-CT that was not identified by CT alone, changing the nodal status of tumor staging in those patients. This study demonstrated the usefulness of PET-CT-based target volume delineation in patients with MPM. Co-registration of PET and CT information reduces the likelihood of geographic misses, and additionally, significant reductions observed in target volumes may potentially allow escalation of RT dose beyond

  17. Fuzzy clustering-based segmented attenuation correction in whole-body PET

    CERN Document Server

    Zaidi, H; Boudraa, A; Slosman, DO

    2001-01-01

    Segmented-based attenuation correction is now a widely accepted technique to reduce noise contribution of measured attenuation correction. In this paper, we present a new method for segmenting transmission images in positron emission tomography. This reduces the noise on the correction maps while still correcting for differing attenuation coefficients of specific tissues. Based on the Fuzzy C-Means (FCM) algorithm, the method segments the PET transmission images into a given number of clusters to extract specific areas of differing attenuation such as air, the lungs and soft tissue, preceded by a median filtering procedure. The reconstructed transmission image voxels are therefore segmented into populations of uniform attenuation based on the human anatomy. The clustering procedure starts with an over-specified number of clusters followed by a merging process to group clusters with similar properties and remove some undesired substructures using anatomical knowledge. The method is unsupervised, adaptive and a...

  18. Whole-body PET/MRI: The effect of bone attenuation during MR-based attenuation correction in oncology imaging

    Energy Technology Data Exchange (ETDEWEB)

    Aznar, M.C., E-mail: marianne.aznar@regionh.dk [Department of Oncology, Section of Radiotherapy 3994, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen (Denmark); Sersar, R., E-mail: rachidadk@hotmail.com [DTU Informatics, Technical University of Denmark, Kongens Lyngby (Denmark); Saabye, J., E-mail: julie_saa@hotmail.com [DTU Informatics, Technical University of Denmark, Kongens Lyngby (Denmark); Ladefoged, C.N., E-mail: claesnl@gmail.com [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Andersen, F.L., E-mail: Flemming.Andersen@regionh.dk [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Rasmussen, J.H., E-mail: jacobrasmu@gmail.com [Department of Oncology, Section of Radiotherapy 3994, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen (Denmark); Löfgren, J., E-mail: Johan.Loefgren@regionh.dk [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Beyer, T., E-mail: thomas.beyer@meduniwien.ac.at [Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna (Austria)

    2014-07-15

    Purpose: In combined PET/MRI standard PET attenuation correction (AC) is based on tissue segmentation following dedicated MR sequencing and, typically, bone tissue is not represented. We evaluate PET quantification in whole-body (WB)-PET/MRI following MR-AC without considering bone attenuation and then investigate different strategies to account for bone tissue in clinical PET/MR imaging. To this purpose, bone tissue representation was extracted from separate CT images, and different bone representations were simulated from hypothetically derived MR-based bone classifications. Methods: Twenty oncology patients referred for a PET/CT were injected with either [18F]-FDG or [18F]-NaF and imaged on PET/CT (Biograph TruePoint/mCT, Siemens) and PET/MRI (mMR, Siemens) following a standard single-injection, dual-imaging clinical WB-protocol. Routine MR-AC was based on in-/opposed-phase MR imaging (orgMR-AC). PET(/MRI) images were reconstructed (AW-OSEM, 3 iterations, 21 subsets, 4 mm Gaussian) following routine MR-AC and MR-AC based on four modified attenuation maps. These modified attenuation maps were created for each patient by non-linear co-registration of the CT images to the orgMR-AC images, and adding CT bone mask values representing cortical bone: 1200 HU (cortCT), spongiosa bone: 350 HU (spongCT), average CT value (meanCT) and original CT values (orgCT). Relative difference images of the PET following AC using the modified attenuation maps were compared. SUVmean was calculated in anatomical reference regions and for PET-positive lesions. Results: The relative differences in SUVmean across patients following orgMR-AC and orgCT in soft tissue lesions and in bone lesions were similar (range: 0.0% to −22.5%), with an average underestimation of SUVmean of 7.2% and 10.0%, respectively when using orgMR-AC. In bone lesions, spongCT values were closest to orgCT (median bias of 1.3%, range: –9.0% to 13.5%) while the overestimation of SUVmean with respect to orgCT was

  19. Cost-effectiveness of FDG-PET for the management of potentially operable non-small cell lung cancer: priority for a PET-based strategy after nodal-negative CT results

    International Nuclear Information System (INIS)

    Dietlein, M.; Weber, K.; Moka, D.; Theissen, P.; Schicha, H.

    2000-01-01

    Decision analysis is used here to establish the most cost-effective strategy for management of potentially operable non-small cell lung cancers (NSCLCs). The strategies compared were conventional staging (strategy A), dedicated systems of positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) in patients with normal-sized (strategy B) or in patients with enlarged mediastinal lymph nodes (part of strategy C), and FDG-PET followed by exclusion from surgical procedures when both computed tomography (CT) and PET were positive for mediastinal lymph nodes (strategy D) or when PET alone was positive (strategy E). Based on published data, the sensitivity and specificity of FDG-PET were estimated at 0.74 and 0.96 for detecting metastasis in normal-sized mediastinal lymph nodes, and at 0.95 and 0.76 when these lymph nodes were enlarged. The calculated probability of up-staging to M1 by using PET was 0.05. The costs quoted correspond to the cost reimbursed in 1999 by the public health provider in Germany. The incremental cost-effectiveness ratio (ICER) of strategy B was much more favourable (143 EUR/LYS; LYS = life year saved) than the ICER of strategy C (36,667 EUR/LYS). In strategy B, the use of PET did not raise the overall costs because the costs of PET were almost balanced by a better selection of patients for beneficial cancer resection. The exclusion from biopsy confirmation in strategies D and E led to cost savings that did not justify the expected reduction in life expectancy. In sensitivity analyses, the ICERs of strategy B were robust to the pretest likelihood of N2/N3, to penalized test parameters of PET and to reimbursement of PET. However, the ICER of strategy B would be raised to 28,000 EUR/LYS through use of thoracic PET without whole-body scanning. To conclude, the implementation of whole-body PET with a full ring of detectors in the preoperative staging of patients with NSCLC and normal-sized lymph nodes is clearly cost

  20. Preparation and characterization of polymer blends based on recycled PET and polyester derived by terephthalic acid; Preparacao e caracterizacao de blendas polimericas a base de PET reciclado e poliester derivado do acido tereftalico

    Energy Technology Data Exchange (ETDEWEB)

    Ohara, L.; Miranda, C.S.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M., E-mail: leandro.ohara@gmail.co [Universidade Federal da Bahia (GECIM/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais

    2010-07-01

    Environmentally friendly materials, made from industrial waste, are being increasingly used as a solution to the growing amount of waste generated by society, but also as a cheaper alternative to replace conventional materials for use in construction. In this work were investigated the properties of polymer blends based on recycled PET and a polyester derived from terephthalic acid and glycerin, a co-product of biodiesel. The samples were characterized by XRD, TGA, DSC, FTIR and SEM. The polyester synthesized showed a degradation event near 300 deg C. The blends with higher ratio of PET showed thermal behavior similar to pure PET. The X-ray diffraction showed that the polymer blends are semicrystalline materials. The micrographs presents the presence of a smooth surface, indicating the possibility of miscibility between the arrays. Therefore, the blending makes possible the fabrication of low-cost materials with applications in several areas. (author)

  1. A temperature-dependent gain control system for improving the stability of Si-PM-based PET systems

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Satomi, Junkichi; Watabe, Tadashi; Imaizumi, Masao; Shimosegawa, Eku; Hatazawa, Jun; Watabe, Hiroshi; Kanai, Yasukazu

    2011-01-01

    The silicon-photomultiplier (Si-PM) is a promising photodetector for the development of new PET systems due to its small size, high gain and relatively low sensitivity to the static magnetic field. One drawback of the Si-PM is that it has significant temperature-dependent gain that poses a problem for the stability of the Si-PM-based PET system. To reduce this problem, we developed and tested a temperature-dependent gain control system for the Si-PM-based PET system. The system consists of a thermometer, analog-to-digital converter, personal computer, digital-to-analog converter and variable gain amplifiers in the weight summing board of the PET system. Temperature characteristics of the Si-PM array are measured and the calculated correction factor is sent to the variable gain amplifier. Without this correction, the temperature-dependent peak channel shifts of the block detector were -55% from 20 deg. C to 35 deg.C. With the correction, the peak channel variations were corrected within ±8%. The coincidence count rate of the Si-PM-based PET system was measured using a Na-22 point source while monitoring the room temperature. Without the correction, the count rate inversely changed with the room temperature by 10% for 1.5 deg. C temperature changes. With the correction, the count rate variation was reduced to within 3.7%. These results indicate that the developed temperature-dependent gain control system can contribute to improving the stability of Si-PM-based PET systems.

  2. Diagnostic accuracy and cost-effectiveness of FDG-PET in recurrent colorectal carcinoma. An analysis based on the results of questionnaire

    International Nuclear Information System (INIS)

    Ito, Kengo; Kato, Takashi; Inagaki, Hiroshi

    2000-01-01

    This study was done by the PET working group under Japan Radioisotope Association. The usefulness of [ 18 F]fluorodeoxyglucose (FDG)-PET in detecting local recurrence of colorectal carcinoma was investigated retrospectively, by the results of questionnaire. Six institutions participated in this study. One hundred and four cases were analyzed to calculate the diagnostic accuracy. The accuracy of FDG-PET in detecting local recurrence of colorectal carcinoma was 96.2%, with two false positive and two false negative cases. We also evaluated the cost-effectiveness of FDG-PET in staging recurrent colorectal carcinoma based on the results of questionnaire. FDG-PET reduced unnecessary radical surgery by 50% in comparison with that in the conventional protocol without PET, and the net savings were about 6.6 billion yen per year in Japan. (author)

  3. Loss of P53 Function in Colon Cancer Cells Results in Increased Phosphocholine and Total Choline

    Directory of Open Access Journals (Sweden)

    Noriko Mori

    2004-10-01

    Full Text Available Mutations in the p53 gene are the most frequently observed genetic lesions in human cancers. Human cancers that contain a p53 mutation are more aggressive, more apt to metastasize, and more often fatal. p53 controls numerous downstream targets that can influence various outcomes such as apoptosis, growth arrest, and DNA repair. Based on previous observations using 1H magnetic resonance spectroscopy (MRS, we have identified choline phospholipid metabolite intensities typical of increased malignancy. Here we have used 1H MRS to characterize the choline phospholipid metabolite levels of p53+/+ and p53−/– cells, and demonstrated that loss of p53 function results in increased phosphocholine and total choline. These data suggest that the increased malignancy of cancer cells resulting from loss of p53 may be mediated, in part, through the choline phospholipid pathway.

  4. Evaluation of a low-carbohydrate diet-based preparation protocol without fasting for cardiac PET/MR imaging.

    Science.gov (United States)

    Nensa, Felix; Tezgah, E; Schweins, K; Goebel, J; Heusch, P; Nassenstein, K; Schlosser, T; Poeppel, T D

    2017-06-01

    Assessment of increased glucose uptake in inflammatory or malignant myocardial disease using PET/MRI relies on uptake suppression in normal myocardium. We evaluated the efficacy of a ≥24 hours high-fat, low-carbohydrate, and protein-permitted diet (HFLCPP) in combination with unfractionated heparin for suppression of "physiologic" myocardial glucose uptake. PET/MRI was successfully performed in 89 patients. HFLCPP was started ≥24 hours prior to PET/MRI. All patients received i.v. injection of unfractionated heparin (50 IU·kg -1 ) 15 minutes prior to FDG administration. Left ventricular FDG uptake was visually evaluated by two readers. Diffuse myocardial uptake exceeding liver uptake, isolated uptake in the lateral wall, or diffuse uptake in the entire circumference of the heart base were defined as failed suppression. Homogeneous myocardial uptake below liver uptake with/without focal uptake was defined as successful suppression. Success rate was 84%. Suppression was unsuccessful in 14 patients. No significant influence of gender (P = .40) or age (P = .21) was found. However, insufficient suppression was more common in patients younger than 45 years (20% vs 7%). PET/MR imaging completion rate was >97%. A HFLCPP diet in combination with unfractionated heparin was successfully implemented for cardiac PET/MRI and resulted in a sufficient suppression of myocardial FDG uptake in 84% of patients.

  5. Validation of PSF-based 3D reconstruction for myocardial blood flow measurements with Rb-82 PET

    DEFF Research Database (Denmark)

    Tolbod, Lars Poulsen; Christensen, Nana Louise; Møller, Lone W.

    images, filtered backprojection (FBP). Furthermore, since myocardial segmentation might be affected by image quality, two different approaches to segmentation implemented in standard software (Carimas (Turku PET Centre) and QPET (Cedar Sinai)) are utilized. Method:14 dynamic rest-stress Rb-82 patient......-scans performed on a GE Discovery 690 PET/CT were included. Images were reconstructed in an isotropic matrix (3.27x3.27x3.27 mm) using PSF (SharpIR: 3 iterations and 21 subsets) and FBP (FORE FBP) with the same edge-preserving filter (3D Butterworth: cut-off 10 mm, power 10). Analysis: The dynamic PET......Aim:The use of PSF-based 3D reconstruction algorithms (PSF) is desirable in most clinical PET-exams due to their superior image quality. Rb-82 cardiac PET is inherently noisy due to short half-life and prompt gammas and would presumably benefit from PSF. However, the quantitative behavior of PSF...

  6. Practical considerations for image-based PSF and blobs reconstruction in PET

    International Nuclear Information System (INIS)

    Stute, Simon; Comtat, Claude

    2013-01-01

    Iterative reconstructions in positron emission tomography (PET) need a model relating the recorded data to the object/patient being imaged, called the system matrix (SM). The more realistic this model, the better the spatial resolution in the reconstructed images. However, a serious concern when using a SM that accurately models the resolution properties of the PET system is the undesirable edge artefact, visible through oscillations near sharp discontinuities in the reconstructed images. This artefact is a natural consequence of solving an ill-conditioned inverse problem, where the recorded data are band-limited. In this paper, we focus on practical aspects when considering image-based point-spread function (PSF) reconstructions. To remove the edge artefact, we propose to use a particular case of the method of sieves (Grenander 1981 Abstract Inference New York: Wiley), which simply consists in performing a standard PSF reconstruction, followed by a post-smoothing using the PSF as the convolution kernel. Using analytical simulations, we investigate the impact of different reconstruction and PSF modelling parameters on the edge artefact and its suppression, in the case of noise-free data and an exactly known PSF. Using Monte-Carlo simulations, we assess the proposed method of sieves with respect to the choice of the geometric projector and the PSF model used in the reconstruction. When the PSF model is accurately known, we show that the proposed method of sieves succeeds in completely suppressing the edge artefact, though after a number of iterations higher than typically used in practice. When applying the method to realistic data (i.e. unknown true SM and noisy data), we show that the choice of the geometric projector and the PSF model does not impact the results in terms of noise and contrast recovery, as long as the PSF has a width close to the true PSF one. Equivalent results were obtained using either blobs or voxels in the same conditions (i.e. the blob

  7. Sensitivity study of voxel-based PET image comparison to image registration algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Yip, Stephen, E-mail: syip@lroc.harvard.edu; Chen, Aileen B.; Berbeco, Ross [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Aerts, Hugo J. W. L. [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 and Department of Radiology, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2014-11-01

    Purpose: Accurate deformable registration is essential for voxel-based comparison of sequential positron emission tomography (PET) images for proper adaptation of treatment plan and treatment response assessment. The comparison may be sensitive to the method of deformable registration as the optimal algorithm is unknown. This study investigated the impact of registration algorithm choice on therapy response evaluation. Methods: Sixteen patients with 20 lung tumors underwent a pre- and post-treatment computed tomography (CT) and 4D FDG-PET scans before and after chemoradiotherapy. All CT images were coregistered using a rigid and ten deformable registration algorithms. The resulting transformations were then applied to the respective PET images. Moreover, the tumor region defined by a physician on the registered PET images was classified into progressor, stable-disease, and responder subvolumes. Particularly, voxels with standardized uptake value (SUV) decreases >30% were classified as responder, while voxels with SUV increases >30% were progressor. All other voxels were considered stable-disease. The agreement of the subvolumes resulting from difference registration algorithms was assessed by Dice similarity index (DSI). Coefficient of variation (CV) was computed to assess variability of DSI between individual tumors. Root mean square difference (RMS{sub rigid}) of the rigidly registered CT images was used to measure the degree of tumor deformation. RMS{sub rigid} and DSI were correlated by Spearman correlation coefficient (R) to investigate the effect of tumor deformation on DSI. Results: Median DSI{sub rigid} was found to be 72%, 66%, and 80%, for progressor, stable-disease, and responder, respectively. Median DSI{sub deformable} was 63%–84%, 65%–81%, and 82%–89%. Variability of DSI was substantial and similar for both rigid and deformable algorithms with CV > 10% for all subvolumes. Tumor deformation had moderate to significant impact on DSI for progressor

  8. SiliPET: Design of an ultra-high resolution small animal PET scanner based on stacks of semi-conductor detectors

    International Nuclear Information System (INIS)

    Cesca, N.; Auricchio, N.; Di Domenico, G.; Zavattini, G.; Malaguti, R.; Andritschke, R.; Kanbach, G.; Schopper, F.

    2007-01-01

    We studied with Monte Carlo simulations, using the EGSnrc code, a new scanner for small animal positron emission tomography (PET), based on stacks of double-sided semiconductor detectors. Each stack is composed of planar detectors with dimension 70x60x1 mm 3 and orthogonal strips on both sides with 500 μm pitch to read the two interaction coordinates, the third being the detector number in the stack. Multiple interactions in a stack are discarded. In this way, we achieve a precise determination of the first interaction point of the two 511 keV photons. The reduced dimensions of the scanner also improve the solid angle coverage resulting in a high sensitivity. Preliminary results of scanners based on Si planar detectors are presented and the initial tomographic reconstructions demonstrate very good spatial resolution limited only by the positron range. This suggests that, this is a promising new approach for small animal PET imaging. We are testing some double-sided silicon detectors, equipped with 128 orthogonal p and n strips on opposite sides using VATAGP3 ASIC by IDEAS

  9. Imaging with PET system

    International Nuclear Information System (INIS)

    Das, B.K.; Noreen Norfaraheen Lee Abdullah

    2012-01-01

    PET deals with biochemistry and metabolic changes that occur at molecular level. Hence, PET differs fundamentally from other imaging modalities. CT imaging is based on tissue density, whereas MRI conveys anatomic information based on proton density and proton relaxation dynamics. CT and MRI are useful in clinical diagnosis only when disease process has caused significant anatomic alterations. However, in most disease conditions chemical changes precede anatomic changes, that can be detected by PET technology. Thus, PET can provide earliest and unique information about ongoing disease process long before anatomic or structural changes take place. There is no other modality available at present that can replace PET technology. Although PET produces cross-sectional images like that obtained in MRI or CT, they represent circulation, function and metabolism, and not anatomic structure. PET is extremely sensitive measuring quantitatively concentration of tracers in nano to pico-molar range. Thus, PET enables merger of biochemistry and biology in medicine giving birth to molecular medicine that focuses on identifying the molecular errors of disease leading to developing molecular corrections including gene therapy. Molecular imaging with PET has been playing a role in examining the biological nature of a disease condition and its characterization to guide selection and evaluation of treatment. (author)

  10. The Semi-automatic Synthesis of 18F-fluoroethyl-choline by Domestic FDG Synthesizer

    Directory of Open Access Journals (Sweden)

    ZHOU Ming

    2016-02-01

    Full Text Available As an important complementary imaging agent for 18F-FDG, 18F-fluoroethyl-choline (18F-FECH has been demonstrated to be promising in brain and prostate cancer imaging. By using domestic PET-FDG-TI-I CPCU synthesizer, 18F-FECH was synthesized by different reagents and consumable supplies. The C18 column was added before the product collection bottle to remove K2.2.2. The 18F-FECH was synthesized by PET-FDG-IT-I synthesizer efficiently about 30 minutes by radiochemical yield of 42.0% (no decay corrected, n=5, and the radiochemical purity was still more than 99.0% after 6 hours. The results showed the domestic PET-FDG-IT-I synthesizer could semi-automatically synthesize injectable 18F-FECH in high efficiency and radiochemical purity

  11. Evaluation of signal energy calculation methods for a light-sharing SiPM-based PET detector

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Qingyang [School of Automation and Electrical Engineering, University of Science & Technology Beijing, Beijing 100083 (China); Beijing Engineering Research Center of Industrial Spectrum Imaging, University of Science and Technology Beijing, Beijing 100083 (China); Ma, Tianyu; Xu, Tianpeng; Liu, Yaqiang; Wang, Shi [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Gu, Yu, E-mail: guyu@ustb.edu.cn [School of Automation and Electrical Engineering, University of Science & Technology Beijing, Beijing 100083 (China)

    2017-03-11

    Signals of a light-sharing positron emission tomography (PET) detector are commonly multiplexed to three analog pulses (E, X, and Y) and then digitally sampled. From this procedure, the signal energy that are critical to detector performance are obtained. In this paper, different signal energy calculation strategies for a self-developed SiPM-based PET detector, including pulse height and different integration methods, are evaluated in terms of energy resolution and spread of the crystal response in the flood histogram using a root-mean-squared (RMS) index. Results show that integrations outperform the pulse height. Integration using the maximum derivative value of the pulse E as the landmark point and 28 integrated points (448 ns) has the best performance in these evaluated methods for our detector. Detector performance in terms of energy and position is improved with this integration method. The proposed methodology is expected to be applicable for other light-sharing PET detectors.

  12. Effect of hypoxia on the uptake of [methyl-3H]choline, [1-14C] acetate and [18F]FDG in cultured prostate cancer cells

    International Nuclear Information System (INIS)

    Hara, Toshihiko; Bansal, Aditya; DeGrado, Timothy R.

    2006-01-01

    Introduction: Choline, acetate and glucose ([2- 18 F]fluoro-2-deoxyglucose, [ 18 F]FDG) analogs are under investigation as positron emission tomography (PET) tracers for the imaging of prostate cancer; however, their response to tumor hypoxia has not been clarified. Methods: The uptake of [methyl- 3 H]choline, [1- 14 C]acetate and [ 18 F]FDG was monitored in androgen-independent PC-3 cells and androgen-sensitive LNCaP cells under aerobic or anoxic conditions. The effect of androgen depletion was also examined. Results: PC-3 cells exhibited aerobic choline and acetate uptake five to six times higher than FDG uptake, whereas LNCaP cells showed choline uptake 2.2-fold higher than acetate uptake and 10-fold higher than FDG uptake. After 4 h of anoxia, PC-3 cells showed an 85% increase in FDG uptake, a 15% decrease in choline uptake and a 36% increase in acetate uptake, whereas LNCaP cells showed a 212% increase in FDG uptake, a 28% decrease in choline uptake and no change in acetate uptake. Androgen depletion resulted in a marked decrease in the uptake of all tracers in LNCaP cells but no changes in PC-3 cells. Conclusion: In aerobic conditions, both PC-3 and LNCaP cells exhibited an order of uptake preference as follows: choline>acetate>FDG. In hypoxic cells, the order is reversed, reflecting diverse biochemical responses to hypoxia. These findings may help to explain PET imaging findings of the diverse responses of these tracers in different stages and locations of prostate cancer. Androgen depletion markedly suppressed the uptake of all three tracers in LNCaP cells, which suggests the potential for underestimation of the disease state when PET imaging is performed subsequent to antiandrogen therapy

  13. Impact of total PSA, PSA doubling time and PSA velocity on detection rates of 11C-Choline positron emission tomography in recurrent prostate cancer

    NARCIS (Netherlands)

    Rybalov, Maxim; Breeuwsma, Anthonius J.; Leliveld, Anna M.; Pruim, Jan; Dierckx, Rudi A.; de Jong, Igle J.

    PURPOSE: To evaluate the effect of total PSA (tPSA) and PSA kinetics on the detection rates of (11)C-Choline PET in patients with biochemical recurrence (BCR) after radical prostatectomy (RP) or external beam radiotherapy (EBRT). METHODS: We included 185 patients with BCR after RP (PSA >0.2 ng/ml)

  14. PET Motion Compensation for Radiation Therapy Using a CT-Based Mid-Position Motion Model: Methodology and Clinical Evaluation

    International Nuclear Information System (INIS)

    Kruis, Matthijs F.; Kamer, Jeroen B. van de; Houweling, Antonetta C.; Sonke, Jan-Jakob; Belderbos, José S.A.; Herk, Marcel van

    2013-01-01

    Purpose: Four-dimensional positron emission tomography (4D PET) imaging of the thorax produces sharper images with reduced motion artifacts. Current radiation therapy planning systems, however, do not facilitate 4D plan optimization. When images are acquired in a 2-minute time slot, the signal-to-noise ratio of each 4D frame is low, compromising image quality. The purpose of this study was to implement and evaluate the construction of mid-position 3D PET scans, with motion compensated using a 4D computed tomography (CT)-derived motion model. Methods and Materials: All voxels of 4D PET were registered to the time-averaged position by using a motion model derived from the 4D CT frames. After the registration the scans were summed, resulting in a motion-compensated 3D mid-position PET scan. The method was tested with a phantom dataset as well as data from 27 lung cancer patients. Results: PET motion compensation using a CT-based motion model improved image quality of both phantoms and patients in terms of increased maximum SUV (SUV max ) values and decreased apparent volumes. In homogenous phantom data, a strong relationship was found between the amplitude-to-diameter ratio and the effects of the method. In heterogeneous patient data, the effect correlated better with the motion amplitude. In case of large amplitudes, motion compensation may increase SUV max up to 25% and reduce the diameter of the 50% SUV max volume by 10%. Conclusions: 4D CT-based motion-compensated mid-position PET scans provide improved quantitative data in terms of uptake values and volumes at the time-averaged position, thereby facilitating more accurate radiation therapy treatment planning of pulmonary lesions

  15. Prediction of CT Substitutes from MR Images Based on Local Diffeomorphic Mapping for Brain PET Attenuation Correction.

    Science.gov (United States)

    Wu, Yao; Yang, Wei; Lu, Lijun; Lu, Zhentai; Zhong, Liming; Huang, Meiyan; Feng, Yanqiu; Feng, Qianjin; Chen, Wufan

    2016-10-01

    Attenuation correction is important for PET reconstruction. In PET/MR, MR intensities are not directly related to attenuation coefficients that are needed in PET imaging. The attenuation coefficient map can be derived from CT images. Therefore, prediction of CT substitutes from MR images is desired for attenuation correction in PET/MR. This study presents a patch-based method for CT prediction from MR images, generating attenuation maps for PET reconstruction. Because no global relation exists between MR and CT intensities, we propose local diffeomorphic mapping (LDM) for CT prediction. In LDM, we assume that MR and CT patches are located on 2 nonlinear manifolds, and the mapping from the MR manifold to the CT manifold approximates a diffeomorphism under a local constraint. Locality is important in LDM and is constrained by the following techniques. The first is local dictionary construction, wherein, for each patch in the testing MR image, a local search window is used to extract patches from training MR/CT pairs to construct MR and CT dictionaries. The k-nearest neighbors and an outlier detection strategy are then used to constrain the locality in MR and CT dictionaries. Second is local linear representation, wherein, local anchor embedding is used to solve MR dictionary coefficients when representing the MR testing sample. Under these local constraints, dictionary coefficients are linearly transferred from the MR manifold to the CT manifold and used to combine CT training samples to generate CT predictions. Our dataset contains 13 healthy subjects, each with T1- and T2-weighted MR and CT brain images. This method provides CT predictions with a mean absolute error of 110.1 Hounsfield units, Pearson linear correlation of 0.82, peak signal-to-noise ratio of 24.81 dB, and Dice in bone regions of 0.84 as compared with real CTs. CT substitute-based PET reconstruction has a regression slope of 1.0084 and R 2 of 0.9903 compared with real CT-based PET. In this method, no

  16. Four-week dietary supplementation with 10- and/or 15-fold basal choline caused decreased body weight in Sprague Dawley rats.

    Science.gov (United States)

    Bagley, Bradford D; Chang, Shu-Ching; Ehresman, David J; Eveland, Alan; Parker, George A; Peters, Jeffrey M; Butenhoff, John L

    2017-10-01

    Choline is an essential nutrient utilized for phosphatidylcholine biosynthesis and lipoprotein packaging and secretion. Recently, choline supplementation has been used by athletes and the public for weight loss. However, the potential toxicological impact of choline dietary supplementation requires further investigation. This study examined the effects of choline dietary supplementation in Sprague Dawley rats for 4 weeks. Rats were fed diets containing basal choline levels (control) or 5-, 10-, or 15-fold (5×, 10×, or 15×) basal diet concentration. In groups fed choline-supplemented diets, there were no toxicologically relevant findings in clinical observations, food intake, clinical chemistry, liver weights, or liver histopathology. However, decreased mean body weights (8.5-10.2%) and body weight gains (24-31%) were noted for the 10× choline-supplemented (females only) and 15× choline-supplemented (both sexes) groups relative to the control groups from day 3 onward. These body weight effects were not related to a persistent reduction in average food intake. Serum cholesterol was increased in the 15× choline-supplemented male rats relative to the controls, an expected effect of choline supplementation; however, there were no changes in the serum cholesterol of female rats. Serum choline concentrations were increased in female rats relative to the male rats across all treatment groups. The maximum tolerated dose for male and female rats were the 15× and 10× choline supplements, respectively, based on decreased mean body weight and body weight gains. This study supported the conclusions of a clinical trial that showed a high choline diet can decrease body weight in humans.

  17. Whole-body PET/MRI: The effect of bone attenuation during MR-based attenuation correction in oncology imaging

    DEFF Research Database (Denmark)

    Aznar, M.C.; Sersar, Rachida; Saabye, J.

    2014-01-01

    and then investigate different strategies to account for bone tissue in clinical PET/MR imaging. To this purpose, bone tissue representation was extracted from separate CT images, and different bone representations were simulated from hypothetically derived MR-based bone classifications. Methods: Twenty oncology...

  18. 89Zr-Oxine Complex PET Cell Imaging in Monitoring Cell-based Therapies

    Science.gov (United States)

    Wu, Haitao; Asiedu, Kingsley O.; Szajek, Lawrence P.; Griffiths, Gary L.; Choyke, Peter L.

    2015-01-01

    Purpose To develop a clinically translatable method of cell labeling with zirconium 89 (89Zr) and oxine to track cells with positron emission tomography (PET) in mouse models of cell-based therapy. Materials and Methods This study was approved by the institutional animal care committee. 89Zr-oxine complex was synthesized in an aqueous solution. Cell labeling conditions were optimized by using EL4 mouse lymphoma cells, and labeling efficiency was examined by using dendritic cells (DCs) (n = 4), naïve (n = 3) and activated (n = 3) cytotoxic T cells (CTLs), and natural killer (NK) (n = 4), bone marrow (n = 4), and EL4 (n = 4) cells. The effect of 89Zr labeling on cell survival, proliferation, and function were evaluated by using DCs (n = 3) and CTLs (n = 3). Labeled DCs (444–555 kBq/[5 × 106] cells, n = 5) and CTLs (185 kBq/[5 × 106] cells, n = 3) transferred to mice were tracked with microPET/CT. In a melanoma immunotherapy model, tumor targeting and cytotoxic function of labeled CTLs were evaluated with imaging (248.5 kBq/[7.7 × 106] cells, n = 4) and by measuring the tumor size (n = 6). Two-way analysis of variance was used to compare labeling conditions, the Wilcoxon test was used to assess cell survival and proliferation, and Holm-Sidak multiple tests were used to assess tumor growth and perform biodistribution analyses. Results 89Zr-oxine complex was synthesized at a mean yield of 97.3% ± 2.8 (standard deviation). It readily labeled cells at room temperature or 4°C in phosphate-buffered saline (labeling efficiency range, 13.0%–43.9%) and was stably retained (83.5% ± 1.8 retention on day 5 in DCs). Labeling did not affect the viability of DCs and CTLs when compared with nonlabeled control mice (P > .05), nor did it affect functionality. 89Zr-oxine complex enabled extended cell tracking for 7 days. Labeled tumor-specific CTLs accumulated in the tumor (4.6% on day 7) and induced tumor regression (P cell tracking technique for use with PET that is

  19. (89)Zr-Oxine Complex PET Cell Imaging in Monitoring Cell-based Therapies.

    Science.gov (United States)

    Sato, Noriko; Wu, Haitao; Asiedu, Kingsley O; Szajek, Lawrence P; Griffiths, Gary L; Choyke, Peter L

    2015-05-01

    To develop a clinically translatable method of cell labeling with zirconium 89 ((89)Zr) and oxine to track cells with positron emission tomography (PET) in mouse models of cell-based therapy. This study was approved by the institutional animal care committee. (89)Zr-oxine complex was synthesized in an aqueous solution. Cell labeling conditions were optimized by using EL4 mouse lymphoma cells, and labeling efficiency was examined by using dendritic cells (DCs) (n = 4), naïve (n = 3) and activated (n = 3) cytotoxic T cells (CTLs), and natural killer (NK) (n = 4), bone marrow (n = 4), and EL4 (n = 4) cells. The effect of (89)Zr labeling on cell survival, proliferation, and function were evaluated by using DCs (n = 3) and CTLs (n = 3). Labeled DCs (444-555 kBq/[5 × 10(6)] cells, n = 5) and CTLs (185 kBq/[5 × 10(6)] cells, n = 3) transferred to mice were tracked with microPET/CT. In a melanoma immunotherapy model, tumor targeting and cytotoxic function of labeled CTLs were evaluated with imaging (248.5 kBq/[7.7 × 10(6)] cells, n = 4) and by measuring the tumor size (n = 6). Two-way analysis of variance was used to compare labeling conditions, the Wilcoxon test was used to assess cell survival and proliferation, and Holm-Sidak multiple tests were used to assess tumor growth and perform biodistribution analyses. (89)Zr-oxine complex was synthesized at a mean yield of 97.3% ± 2.8 (standard deviation). It readily labeled cells at room temperature or 4°C in phosphate-buffered saline (labeling efficiency range, 13.0%-43.9%) and was stably retained (83.5% ± 1.8 retention on day 5 in DCs). Labeling did not affect the viability of DCs and CTLs when compared with nonlabeled control mice (P > .05), nor did it affect functionality. (89)Zr-oxine complex enabled extended cell tracking for 7 days. Labeled tumor-specific CTLs accumulated in the tumor (4.6% on day 7) and induced tumor regression (P cell tracking technique for use with PET that is applicable to a broad range of

  20. A PET system based on 2-18FDG production with a low energy electrostatic proton accelerator and a dual headed PET scanner.

    Science.gov (United States)

    Sandell, A; Ohlsson, T; Erlandsson, K; Hellborg, R; Strand, S E

    1992-01-01

    We have developed a comparatively inexpensive PET system, based on a rotating scanner with two scintillation camera heads, and a nearby low energy electrostatic proton accelerator for production of short-lived radionuclides. Using a 6 MeV proton beam of 5 microA, and by optimization of the target geometry for the 18O(p,n)18F reaction, 750 MBq of 2-18FDG can be obtained. The PET scanner shows a spatial resolution of 6 mm (FWHM) and a sensitivity of 80 s-1kBq-1ml-1 (3 kcps/microCi/ml). Various corrections are included in the imaging process, to compensate for spatial and temporal response variations in the detector system. Both filtered backprojection and iterative reconstruction methods are employed. Clinical studies have been performed with acquisition times of 30-40 min. The system will be used for clinical experimental research with short- as well as long-lived positron emitters. Also the possibility of true 3D reconstruction is under evaluation.

  1. SiliPET: An ultra-high resolution design of a small animal PET scanner based on stacks of double-sided silicon strip detector

    International Nuclear Information System (INIS)

    Di Domenico, Giovanni; Zavattini, Guido; Cesca, Nicola; Auricchio, Natalia; Andritschke, Robert; Schopper, Florian; Kanbach, Gottfried

    2007-01-01

    We investigated with Monte Carlo simulations, using the EGSNrcMP code, the capabilities of a small animal PET scanner based on four stacks of double-sided silicon strip detectors. Each stack consists of 40 silicon detectors with dimension of 60x60x1 mm 3 and 128 orthogonal strips on each side. Two coordinates of the interaction are given by the strips, whereas the third coordinate is given by the detector number in the stack. The stacks are arranged to form a box of 5x5x6 cm 3 with minor sides opened; the box represents the minimal FOV of the scanner. The performance parameters of the SiliPET scanner have been estimated giving a (positron range limited) spatial resolution of 0.52 mm FWHM, and an absolute sensitivity of 5.1% at the center of system. Preliminary results of a proof of principle measurement done with the MEGA advanced Compton imager using a ∼1 mm diameter 22 Na source, showed a focal ray tracing FWHM of 1 mm

  2. Diagnostic Challenges in Prostate Cancer and 68Ga-PSMA PET Imaging: A Game Changer?

    Science.gov (United States)

    Zaman, Maseeh uz; Fatima, Nosheen; Zaman, Areeba; Sajid, Mahwsih; Zaman, Unaiza; Zaman, Sidra

    2017-10-26

    Prostate cancer (PC) is the most frequent solid tumor in men and the third most common cause of cancer mortality among men in developed countries. Current imaging modalities like ultrasound (US), computerized tomography (CT), magnetic resonance imaging (MRI) and choline based positron emission (PET) tracing have disappointing sensitivity for detection of nodal metastasis and small tumor recurrence. This poses a diagnostic challenge in staging of intermediate to high risk PC and restaging of patients with biochemical recurrence (PSA >0.2 ng/ml). Gallium-68 labeled prostate specific membrane antigen (68Ga-PSMA) PET imaging has now emerged with a higher diagnostic yield. 68Ga-PSMA PET/CT or PET/MRI can be expected to offer a one-stop-shop for staging and restaging of PC. PSMA ligands labeled with alpha and beta emitters have also shown promising therapeutic efficacy for nodal, bone and visceral metastasis. Therefore a PSMA based theranostics approach for detection, staging, treatment, and follow-up of PC would appear to be highly valuable to achieve personalized PC treatment. Creative Commons Attribution License

  3. Dye-sensitized solar cells based on different nano-oxides on plastic PET substrate

    Science.gov (United States)

    Mikula, Milan; Gemeiner, Pavol; Beková, Zuzana; Dvonka, Vladimír; Búc, Dalibor

    2015-01-01

    Polyethylene-terephthalate (PET) foils and glass slides coated with thin conductive layers were used as substrates for TiO2 or ZnO based photoactive electrodes of dye-sensitized solar cells (DSSC) with organo-metallic Ru-dye, standard iodine electrolyte and Pt coated FTO/glass counterelectrode (CE). Different compositions of nanoparticle oxides in forms of alcohol pastes as well as the CE paste were applied onto the substrates by screen printing or by doctor blade techniques. Photocurrents and I-V loading characteristics were measured depending on the solar cell structure and preparation, including the oxide composition, electrode conductivity and the dye type. The influence of thin TiO2 blocking layer prepared by sol-gel technique is also discussed.

  4. SU-E-J-174: Adaptive PET-Based Dose Painting with Tomotherapy

    International Nuclear Information System (INIS)

    Darwish, N; Mackie, T; Thomadsen, B

    2014-01-01

    Purpose: PET imaging can be converted into dose prescription directly. Due to the variability of the intensity of PET the image, PET prescription maybe superior over uniform dose prescription. Furthermore, unlike the case in image reconstruction of not knowing the image solution in advance, the prescribed dose is known from a PET image a priori. Therefore, optimum beam orientations are derivable. Methods: We can assume the PET image to be the prescribed dose and invert it to determine the energy fluence. The same method used to reconstruct tissue images from projections could be used to solve the inverse problem of determining beam orientations and modulation patterns from a dose prescription [10]. Unlike standard tomographic reconstruction of images from measured projection profiles, the inversion of the prescribed dose results in photon fluence which may be negative and therefore unphysical. Two-dimensional modulated beams can be modelled in terms of the attenuated or exponential radon transform of the prescribed dose function (assumed to be the PET image in this case), an application of a Ram-Lak filter, and inversion by backprojection. Unlike the case in PET processing, however, the filtered beam obtained from the inversion represents a physical photon fluence. Therefore, a positivity constraint for the fluence (setting negative fluence to zero) must be applied (Brahme et al 1982, Bortfeld et al 1990) Results: Truncating the negative profiles from the PET data results in an approximation of the derivable energy fluence. Backprojection of the deliverable fluence is an approximation of the dose delivered. The deliverable dose is comparable to the original PET image and is similar to the PET image. Conclusion: It is possible to use the PET data or image as a direct indicator of deliverable fluence for cylindrical radiotherapy systems such as TomoTherapy

  5. Comparison of MR-based attenuation correction and CT-based attenuation correction of whole-body PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo-Garcia, David [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, New York, NY (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA (United States); Sawiak, Stephen J. [University of Cambridge, Wolfson Brain Imaging Centre, Cambridge (United Kingdom); Knesaurek, Karin; Machac, Joseph [Mount Sinai School of Medicine, Division of Nuclear Medicine, Department of Radiology, New York, NY (United States); Narula, Jagat [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Fuster, Valentin [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); The Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid (Spain); Fayad, Zahi A. [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, New York, NY (United States); Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States)

    2014-08-15

    The objective of this study was to evaluate the performance of the built-in MR-based attenuation correction (MRAC) included in the combined whole-body Ingenuity TF PET/MR scanner and compare it to the performance of CT-based attenuation correction (CTAC) as the gold standard. Included in the study were 26 patients who underwent clinical whole-body FDG PET/CT imaging and subsequently PET/MR imaging (mean delay 100 min). Patients were separated into two groups: the alpha group (14 patients) without MR coils during PET/MR imaging and the beta group (12 patients) with MR coils present (neurovascular, spine, cardiac and torso coils). All images were coregistered to the same space (PET/MR). The two PET images from PET/MR reconstructed using MRAC and CTAC were compared by voxel-based and region-based methods (with ten regions of interest, ROIs). Lesions were also compared by an experienced clinician. Body mass index and lung density showed significant differences between the alpha and beta groups. Right and left lung densities were also significantly different within each group. The percentage differences in uptake values using MRAC in relation to those using CTAC were greater in the beta group than in the alpha group (alpha group -0.2 ± 33.6 %, R{sup 2} = 0.98, p < 0.001; beta group 10.31 ± 69.86 %, R{sup 2} = 0.97, p < 0.001). In comparison to CTAC, MRAC led to underestimation of the PET values by less than 10 % on average, although some ROIs and lesions did differ by more (including the spine, lung and heart). The beta group (imaged with coils present) showed increased overall PET quantification as well as increased variability compared to the alpha group (imaged without coils). PET data reconstructed with MRAC and CTAC showed some differences, mostly in relation to air pockets, metallic implants and attenuation differences in large bone areas (such as the pelvis and spine) due to the segmentation limitation of the MRAC method. (orig.)

  6. Comparison of MR-based attenuation correction and CT-based attenuation correction of whole-body PET/MR imaging

    International Nuclear Information System (INIS)

    Izquierdo-Garcia, David; Sawiak, Stephen J.; Knesaurek, Karin; Machac, Joseph; Narula, Jagat; Fuster, Valentin; Fayad, Zahi A.

    2014-01-01

    The objective of this study was to evaluate the performance of the built-in MR-based attenuation correction (MRAC) included in the combined whole-body Ingenuity TF PET/MR scanner and compare it to the performance of CT-based attenuation correction (CTAC) as the gold standard. Included in the study were 26 patients who underwent clinical whole-body FDG PET/CT imaging and subsequently PET/MR imaging (mean delay 100 min). Patients were separated into two groups: the alpha group (14 patients) without MR coils during PET/MR imaging and the beta group (12 patients) with MR coils present (neurovascular, spine, cardiac and torso coils). All images were coregistered to the same space (PET/MR). The two PET images from PET/MR reconstructed using MRAC and CTAC were compared by voxel-based and region-based methods (with ten regions of interest, ROIs). Lesions were also compared by an experienced clinician. Body mass index and lung density showed significant differences between the alpha and beta groups. Right and left lung densities were also significantly different within each group. The percentage differences in uptake values using MRAC in relation to those using CTAC were greater in the beta group than in the alpha group (alpha group -0.2 ± 33.6 %, R 2 = 0.98, p 2 = 0.97, p < 0.001). In comparison to CTAC, MRAC led to underestimation of the PET values by less than 10 % on average, although some ROIs and lesions did differ by more (including the spine, lung and heart). The beta group (imaged with coils present) showed increased overall PET quantification as well as increased variability compared to the alpha group (imaged without coils). PET data reconstructed with MRAC and CTAC showed some differences, mostly in relation to air pockets, metallic implants and attenuation differences in large bone areas (such as the pelvis and spine) due to the segmentation limitation of the MRAC method. (orig.)

  7. Whole-body bone segmentation from MRI for PET/MRI attenuation correction using shape-based averaging

    DEFF Research Database (Denmark)

    Arabi, Hossein; Zaidi, H.

    2016-01-01

    Purpose: The authors evaluate the performance of shape-based averaging (SBA) technique for whole-body bone segmentation from MRI in the context of MRI-guided attenuation correction (MRAC) in hybrid PET/MRI. To enhance the performance of the SBA scheme, the authors propose to combine it with stati......Purpose: The authors evaluate the performance of shape-based averaging (SBA) technique for whole-body bone segmentation from MRI in the context of MRI-guided attenuation correction (MRAC) in hybrid PET/MRI. To enhance the performance of the SBA scheme, the authors propose to combine...... it with statistical atlas fusion techniques. Moreover, a fast and efficient shape comparisonbased atlas selection scheme was developed and incorporated into the SBA method. Methods: Clinical studies consisting of PET/CT and MR images of 21 patients were used to assess the performance of the SBA method. In addition...... voting (MV) atlas fusion scheme was also evaluated as a conventional and commonly used method. MRI-guided attenuation maps were generated using the different segmentation methods. Thereafter, quantitative analysis of PET attenuation correction was performed using CT-based attenuation correction...

  8. Rapid detection of Salmonella in pet food: design and evaluation of integrated methods based on real-time PCR detection.

    Science.gov (United States)

    Balachandran, Priya; Friberg, Maria; Vanlandingham, V; Kozak, K; Manolis, Amanda; Brevnov, Maxim; Crowley, Erin; Bird, Patrick; Goins, David; Furtado, Manohar R; Petrauskene, Olga V; Tebbs, Robert S; Charbonneau, Duane

    2012-02-01

    Reducing the risk of Salmonella contamination in pet food is critical for both companion animals and humans, and its importance is reflected by the substantial increase in the demand for pathogen testing. Accurate and rapid detection of foodborne pathogens improves food safety, protects the public health, and benefits food producers by assuring product quality while facilitating product release in a timely manner. Traditional culture-based methods for Salmonella screening are laborious and can take 5 to 7 days to obtain definitive results. In this study, we developed two methods for the detection of low levels of Salmonella in pet food using real-time PCR: (i) detection of Salmonella in 25 g of dried pet food in less than 14 h with an automated magnetic bead-based nucleic acid extraction method and (ii) detection of Salmonella in 375 g of composite dry pet food matrix in less than 24 h with a manual centrifugation-based nucleic acid preparation method. Both methods included a preclarification step using a novel protocol that removes food matrix-associated debris and PCR inhibitors and improves the sensitivity of detection. Validation studies revealed no significant differences between the two real-time PCR methods and the standard U.S. Food and Drug Administration Bacteriological Analytical Manual (chapter 5) culture confirmation method.

  9. Voxel-based morphometry (VBM) based assessment of gray matter loss in medial temporal lobe epilepsy; comparison with FDG PET

    International Nuclear Information System (INIS)

    Kang, Hye Jin; Lee, Ho Young; Lee, Jae Sung; Kang, Eun Joo; Lee, Sang Gun; Chang, Kee Hyun; Lee, Dong Soo

    2004-01-01

    The aims of this study were to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphometry (VBM) analysis for lateralizing epileptogenic zones in medial temporal lobe epilepsy (mTLE). The findings were compared with fluorodeoxyglucose positron emission tomography (FDG PET). MR T1-weighted images of 12 left mTLE and 11 right mTLE patients were compared with those of 37 normal controls. Images were transformed to standard MNI space and averaged in order to create study-specific brain template. Each image was normalized to this local template and brain tissues were segmented. Modulation VBM analysis was performed in order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was performed using statistical parametric mapping software (SPM99). FDG PET images were compared with those of 22 normal controls using SPM. Gray matter volume was significantly reduced in the left amygdala and hippocampus in left mTLE. In addition, volume of cerebellum, anterior cingulate, and fusiform gyrus in both sides and left insula was reduced. In right mTLE, volume was reduced significantly in right hippocampus. In contrast, FDG uptake was decreased in broad areas of left or right temporal lobes in left TLE and right TLE, respectively. Gray matter loss was found in the ipsilateral hippocampus by modulation VBM analysis in medial temporal lobe epilepsy. This VBM analysis might be useful in lateralizing the epileptogenic zones in medial temporal lobe epilepsy, while SPM analysis of FDG PET disclosed hypometabolic epileptogenic zones

  10. Voxel-based morphometry (VBM) based assessment of gray matter loss in medial temporal lobe epilepsy; comparison with FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hye Jin; Lee, Ho Young; Lee, Jae Sung; Kang, Eun Joo; Lee, Sang Gun; Chang, Kee Hyun; Lee, Dong Soo [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2004-02-01

    The aims of this study were to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphometry (VBM) analysis for lateralizing epileptogenic zones in medial temporal lobe epilepsy (mTLE). The findings were compared with fluorodeoxyglucose positron emission tomography (FDG PET). MR T1-weighted images of 12 left mTLE and 11 right mTLE patients were compared with those of 37 normal controls. Images were transformed to standard MNI space and averaged in order to create study-specific brain template. Each image was normalized to this local template and brain tissues were segmented. Modulation VBM analysis was performed in order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was performed using statistical parametric mapping software (SPM99). FDG PET images were compared with those of 22 normal controls using SPM. Gray matter volume was significantly reduced in the left amygdala and hippocampus in left mTLE. In addition, volume of cerebellum, anterior cingulate, and fusiform gyrus in both sides and left insula was reduced. In right mTLE, volume was reduced significantly in right hippocampus. In contrast, FDG uptake was decreased in broad areas of left or right temporal lobes in left TLE and right TLE, respectively. Gray matter loss was found in the ipsilateral hippocampus by modulation VBM analysis in medial temporal lobe epilepsy. This VBM analysis might be useful in lateralizing the epileptogenic zones in medial temporal lobe epilepsy, while SPM analysis of FDG PET disclosed hypometabolic epileptogenic zones.

  11. Simulation-based partial volume correction for dopaminergic PET imaging. Impact of segmentation accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Rong, Ye; Winz, Oliver H. [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; Vernaleken, Ingo [University Hospital Aachen (Germany). Dept. of Psychiatry, Psychotherapy and Psychosomatics; Goedicke, Andreas [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; High Tech Campus, Philips Research Lab., Eindhoven (Netherlands); Mottaghy, Felix M. [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; Maastricht University Medical Center (Netherlands). Dept. of Nuclear Medicine; Rota Kops, Elena [Forschungszentrum Juelich (Germany). Inst. of Neuroscience and Medicine-4

    2015-07-01

    Partial volume correction (PVC) is an essential step for quantitative positron emission tomography (PET). In the present study, PVELab, a freely available software, is evaluated for PVC in {sup 18}F-FDOPA brain-PET, with a special focus on the accuracy degradation introduced by various MR-based segmentation approaches. Methods Four PVC algorithms (M-PVC; MG-PVC; mMG-PVC; and R-PVC) were analyzed on simulated {sup 18}F-FDOPA brain-PET images. MR image segmentation was carried out using FSL (FMRIB Software Library) and SPM (Statistical Parametric Mapping) packages, including additional adaptation for subcortical regions (SPM{sub L}). Different PVC and segmentation combinations were compared with respect to deviations in regional activity values and time-activity curves (TACs) of the occipital cortex (OCC), caudate nucleus (CN), and putamen (PUT). Additionally, the PVC impact on the determination of the influx constant (K{sub i}) was assessed. Results Main differences between tissue-maps returned by three segmentation algorithms were found in the subcortical region, especially at PUT. Average misclassification errors in combination with volume reduction was found to be lowest for SPM{sub L} (PUT < 30%) and highest for FSL (PUT > 70%). Accurate recovery of activity data at OCC is achieved by M-PVC (apparent recovery coefficient varies between 0.99 and 1.10). The other three evaluated PVC algorithms have demonstrated to be more suitable for subcortical regions with MG-PVC and mMG-PVC being less prone to the largest tissue misclassification error simulated in this study. Except for M-PVC, quantification accuracy of K{sub i} for CN and PUT was clearly improved by PVC. Conclusions The regional activity value of PUT was appreciably overcorrected by most of the PVC approaches employing FSL or SPM segmentation, revealing the importance of accurate MR image segmentation for the presented PVC framework. The selection of a PVC approach should be adapted to the anatomical

  12. Evaluation of Prostate Cancer Bone Metastases with 18F-NaF and 18F-Fluorocholine PET/CT.

    Science.gov (United States)

    Beheshti, Mohsen; Rezaee, Alireza; Geinitz, Hans; Loidl, Wolfgang; Pirich, Christian; Langsteger, Werner

    2016-10-01

    18 F-fluorocholine is a specific promising agent for imaging tumor cell proliferation, particularly in prostate cancer, using PET/CT. It is a beneficial tool in the early detection of marrow-based metastases because it excludes distant metastases and evaluates the response to hormone therapy. In addition, 18 F-fluorocholine has the potential to differentiate between degenerative and malignant osseous abnormalities because degenerative changes are not choline-avid; however, the agent may accumulate in recent traumatic bony lesions. On the other hand, 18 F-NaF PET/CT can indicate increased bone turnover and is generally used in the assessment of primary and secondary osseous malignancies, the evaluation of response to treatment, and the clarification of abnormalities on other imaging modalities or clinical data. 18 F-NaF PET/CT is a highly sensitive method in the evaluation of bone metastases from prostate cancer, but it has problematic specificity, mainly because of tracer accumulation in degenerative and inflammatory bone diseases. In summary, 18 F-NaF PET/CT is a highly sensitive method, but 18 F-fluorocholine PET/CT can detect early bone marrow metastases and provide greater specificity in the detection of bone metastases in patients with prostate cancer. However, the difference seems not to be significant. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  13. Cerebral 18F-FDG PET in macrophagic myofasciitis: An individual SVM-based approach.

    Science.gov (United States)

    Blanc-Durand, Paul; Van Der Gucht, Axel; Guedj, Eric; Abulizi, Mukedaisi; Aoun-Sebaiti, Mehdi; Lerman, Lionel; Verger, Antoine; Authier, François-Jérôme; Itti, Emmanuel

    2017-01-01

    Macrophagic myofasciitis (MMF) is an emerging condition with highly specific myopathological alterations. A peculiar spatial pattern of a cerebral glucose hypometabolism involving occipito-temporal cortex and cerebellum have been reported in patients with MMF; however, the full pattern is not systematically present in routine interpretation of scans, and with varying degrees of severity depending on the cognitive profile of patients. Aim was to generate and evaluate a support vector machine (SVM) procedure to classify patients between healthy or MMF 18F-FDG brain profiles. 18F-FDG PET brain images of 119 patients with MMF and 64 healthy subjects were retrospectively analyzed. The whole-population was divided into two groups; a training set (100 MMF, 44 healthy subjects) and a testing set (19 MMF, 20 healthy subjects). Dimensionality reduction was performed using a t-map from statistical parametric mapping (SPM) and a SVM with a linear kernel was trained on the training set. To evaluate the performance of the SVM classifier, values of sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (Acc) were calculated. The SPM12 analysis on the training set exhibited the already reported hypometabolism pattern involving occipito-temporal and fronto-parietal cortices, limbic system and cerebellum. The SVM procedure, based on the t-test mask generated from the training set, correctly classified MMF patients of the testing set with following Se, Sp, PPV, NPV and Acc: 89%, 85%, 85%, 89%, and 87%. We developed an original and individual approach including a SVM to classify patients between healthy or MMF metabolic brain profiles using 18F-FDG-PET. Machine learning algorithms are promising for computer-aided diagnosis but will need further validation in prospective cohorts.

  14. A fully automated and scalable timing probe-based method for time alignment of the LabPET II scanners

    Science.gov (United States)

    Samson, Arnaud; Thibaudeau, Christian; Bouchard, Jonathan; Gaudin, Émilie; Paulin, Caroline; Lecomte, Roger; Fontaine, Réjean

    2018-05-01

    A fully automated time alignment method based on a positron timing probe was developed to correct the channel-to-channel coincidence time dispersion of the LabPET II avalanche photodiode-based positron emission tomography (PET) scanners. The timing probe was designed to directly detect positrons and generate an absolute time reference. The probe-to-channel coincidences are recorded and processed using firmware embedded in the scanner hardware to compute the time differences between detector channels. The time corrections are then applied in real-time to each event in every channel during PET data acquisition to align all coincidence time spectra, thus enhancing the scanner time resolution. When applied to the mouse version of the LabPET II scanner, the calibration of 6 144 channels was performed in less than 15 min and showed a 47% improvement on the overall time resolution of the scanner, decreasing from 7 ns to 3.7 ns full width at half maximum (FWHM).

  15. Image fusion between whole body FDG PET images and whole body MRI images using a full-automatic mutual information-based multimodality image registration software

    International Nuclear Information System (INIS)

    Uchida, Yoshitaka; Nakano, Yoshitada; Fujibuchi, Toshiou; Isobe, Tomoko; Kazama, Toshiki; Ito, Hisao

    2006-01-01

    We attempted image fusion between whole body PET and whole body MRI of thirty patients using a full-automatic mutual information (MI) -based multimodality image registration software and evaluated accuracy of this method and impact of the coregistrated imaging on diagnostic accuracy. For 25 of 30 fused images in body area, translating gaps were within 6 mm in all axes and rotating gaps were within 2 degrees around all axes. In head and neck area, considerably much gaps caused by difference of head inclination at imaging occurred in 16 patients, however these gaps were able to decrease by fused separately. In 6 patients, diagnostic accuracy using PET/MRI fused images was superior compared by PET image alone. This work shows that whole body FDG PET images and whole body MRI images can be automatically fused using MI-based multimodality image registration software accurately and this technique can add useful information when evaluating FDG PET images. (author)

  16. Free-running ADC- and FPGA-based signal processing method for brain PET using GAPD arrays

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wei [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Choi, Yong, E-mail: ychoi.image@gmail.com [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Hong, Key Jo [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Kang, Jihoon [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Jung, Jin Ho [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Huh, Youn Suk [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Lim, Hyun Keong; Kim, Sang Su [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Kim, Byung-Tae [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Chung, Yonghyun [Department of Radiological Science, Yonsei University College of Health Science, 234 Meaji, Heungup Wonju, Kangwon-Do 220-710 (Korea, Republic of)

    2012-02-01

    Currently, for most photomultiplier tube (PMT)-based PET systems, constant fraction discriminators (CFD) and time to digital converters (TDC) have been employed to detect gamma ray signal arrival time, whereas anger logic circuits and peak detection analog-to-digital converters (ADCs) have been implemented to acquire position and energy information of detected events. As compared to PMT the Geiger-mode avalanche photodiodes (GAPDs) have a variety of advantages, such as compactness, low bias voltage requirement and MRI compatibility. Furthermore, the individual read-out method using a GAPD array coupled 1:1 with an array scintillator can provide better image uniformity than can be achieved using PMT and anger logic circuits. Recently, a brain PET using 72 GAPD arrays (4 Multiplication-Sign 4 array, pixel size: 3 mm Multiplication-Sign 3 mm) coupled 1:1 with LYSO scintillators (4 Multiplication-Sign 4 array, pixel size: 3 mm Multiplication-Sign 3 mm Multiplication-Sign 20 mm) has been developed for simultaneous PET/MRI imaging in our laboratory. Eighteen 64:1 position decoder circuits (PDCs) were used to reduce GAPD channel number and three off-the-shelf free-running ADC and field programmable gate array (FPGA) combined data acquisition (DAQ) cards were used for data acquisition and processing. In this study, a free-running ADC- and FPGA-based signal processing method was developed for the detection of gamma ray signal arrival time, energy and position information all together for each GAPD channel. For the method developed herein, three DAQ cards continuously acquired 18 channels of pre-amplified analog gamma ray signals and 108-bit digital addresses from 18 PDCs. In the FPGA, the digitized gamma ray pulses and digital addresses were processed to generate data packages containing pulse arrival time, baseline value, energy value and GAPD channel ID. Finally, these data packages were saved to a 128 Mbyte on-board synchronous dynamic random access memory (SDRAM) and

  17. Characterization and detection of a widely distributed gene cluster that predicts anaerobic choline utilization by human gut bacteria.

    Science.gov (United States)

    Martínez-del Campo, Ana; Bodea, Smaranda; Hamer, Hilary A; Marks, Jonathan A; Haiser, Henry J; Turnbaugh, Peter J; Balskus, Emily P

    2015-04-14

    Elucidation of the molecular mechanisms underlying the human gut microbiota's effects on health and disease has been complicated by difficulties in linking metabolic functions associated with the gut community as a whole to individual microorganisms and activities. Anaerobic microbial choline metabolism, a disease-associated metabolic pathway, exemplifies this challenge, as the specific human gut microorganisms responsible for this transformation have not yet been clearly identified. In this study, we established the link between a bacterial gene cluster, the choline utilization (cut) cluster, and anaerobic choline metabolism in human gut isolates by combining transcriptional, biochemical, bioinformatic, and cultivation-based approaches. Quantitative reverse transcription-PCR analysis and in vitro biochemical characterization of two cut gene products linked the entire cluster to growth on choline and supported a model for this pathway. Analyses of sequenced bacterial genomes revealed that the cut cluster is present in many human gut bacteria, is predictive of choline utilization in sequenced isolates, and is widely but discontinuously distributed across multiple bacterial phyla. Given that bacterial phylogeny is a poor marker for choline utilization, we were prompted to develop a degenerate PCR-based method for detecting the key functional gene choline TMA-lyase (cutC) in genomic and metagenomic DNA. Using this tool, we found that new choline-metabolizing gut isolates universally possessed cutC. We also demonstrated that this gene is widespread in stool metagenomic data sets. Overall, this work represents a crucial step toward understanding anaerobic choline metabolism in the human gut microbiota and underscores the importance of examining this microbial community from a function-oriented perspective. Anaerobic choline utilization is a bacterial metabolic activity that occurs in the human gut and is linked to multiple diseases. While bacterial genes responsible for

  18. Non-FDG PET imaging of brain tumors

    Institute of Scientific and Technical Information of China (English)

    HUANG Zemin; GUAN Yihui; ZUO Chuantao; ZHANG Zhengwei; XUE Fangping; LIN Xiangtong

    2007-01-01

    Due to relatively high uptake of glucose in the brain cortex, the use of FDG PET imaging is greatly limited in brain tumor imaging, especially for low-grade gliomas and some metastatic tumours. More and more tracers with higher specificity were developed lately for brain tumor imaging. There are 3 main types of non-FDG PET tracers:amino acid tracers, choline tracers and nucleic acid tracers. These tracers are now widely applied in many aspects of brain tumor imaging. This article summarized the general use of non-FDG PET in different aspects of brain tumor imaging.

  19. The effect of cytidine-diphosphate choline (CDP-choline) on brain lipid changes during aging

    International Nuclear Information System (INIS)

    De Medio, G.E.; Trovarelli, G.; Piccinin, G.L.; Porcellati, G.

    1984-01-01

    Lipid synthesis has been tested in vivo in different brain areas of 12-month-old male rats. Cortex, striatum, brainstem, and subcortex of brain have been examined. The cerebellum was discarded. Mixtures of (2- 3 H)glycerol and (Me- 14 C)choline were injected into the lateral ventricle of the brain as lipid precursors, and their incorporation into total lipid, water-soluble intermediates and choline-containing phospholipids was examined 1 hr after isotope injection. In another series of experiments cytidine-5'-diphosphate choline (CDP-choline) was injected intraventricularly to the aged rats 10 min before sacrifice with a simultaneous injection, and radioactivity assays were performed as above. Distribution of radioactivity content of CDP-choline among brain areas 10 min after its administration showed a noticeable enrichment of the nucleotide and water-soluble-related compounds in the examined areas, but to a lesser degree in the cerebral cortex. The incorporation of labelled glycerol, which is severely depressed in aged rats in all four areas [Gaiti et al, 1982, 1983], was increased only in the cortex, and apparently decreased in the other areas. This last result is probably due to a dilution effect brought about by the administered cold CDP-choline upon the ( 14 C)-containing water-soluble metabolites. As a consequence, the ( 3 H)/( 14 C) ratio in total lipid and in isolated phosphatidylcholine and choline plasmalogen increased after CDP-choline treatment

  20. Impact of subject head motion on quantitative brain 15O PET and its correction by image-based registration algorithm

    International Nuclear Information System (INIS)

    Matsubara, Keisuke; Ibaraki, Masanobu; Nakamura, Kazuhiro; Yamaguchi, Hiroshi; Umetsu, Atsushi; Kinoshita, Fumiko; Kinoshita, Toshibumi

    2013-01-01

    Subject head motion during sequential 15 O positron emission tomography (PET) scans can result in artifacts in cerebral blood flow (CBF) and oxygen metabolism maps. However, to our knowledge, there are no systematic studies examining this issue. Herein, we investigated the effect of head motion on quantification of CBF and oxygen metabolism, and proposed an image-based motion correction method dedicated to 15 O PET study, correcting for transmission-emission mismatch and inter-scan mismatch of emission scans. We analyzed 15 O PET data for patients with major arterial steno-occlusive disease (n=130) to determine the occurrence frequency of head motion during 15 O PET examination. Image-based motion correction without and with realignment between transmission and emission scans, termed simple and 2-step method, respectively, was applied to the cases that showed severe inter-scan motion. Severe inter-scan motion (>3 mm translation or >5deg rotation) was observed in 27 of 520 adjacent scan pairs (5.2%). In these cases, unrealistic values of oxygen extraction fraction (OEF) or cerebrovascular reactivity (CVR) were observed without motion correction. Motion correction eliminated these artifacts. The volume-of-interest (VOI) analysis demonstrated that the motion correction changed the OEF on the middle cerebral artery territory by 17.3% at maximum. The inter-scan motion also affected cerebral blood volume (CBV), cerebral metabolism rate of oxygen (CMRO 2 ) and CBF, which were improved by the motion correction. A difference of VOI values between the simple and 2-step method was also observed. These data suggest that image-based motion correction is useful for accurate measurement of CBF and oxygen metabolism by 15 O PET. (author)

  1. SU-C-207B-03: A Geometrical Constrained Chan-Vese Based Tumor Segmentation Scheme for PET

    International Nuclear Information System (INIS)

    Chen, L; Zhou, Z; Wang, J

    2016-01-01

    Purpose: Accurate segmentation of tumor in PET is challenging when part of tumor is connected with normal organs/tissues with no difference in intensity. Conventional segmentation methods, such as thresholding or region growing, cannot generate satisfactory results in this case. We proposed a geometrical constrained Chan-Vese based scheme to segment tumor in PET for this special case by considering the similarity between two adjacent slices. Methods: The proposed scheme performs segmentation in a slice-by-slice fashion where an accurate segmentation of one slice is used as the guidance for segmentation of rest slices. For a slice that the tumor is not directly connected to organs/tissues with similar intensity values, a conventional clustering-based segmentation method under user’s guidance is used to obtain an exact tumor contour. This is set as the initial contour and the Chan-Vese algorithm is applied for segmenting the tumor in the next adjacent slice by adding constraints of tumor size, position and shape information. This procedure is repeated until the last slice of PET containing tumor. The proposed geometrical constrained Chan-Vese based algorithm was implemented in Matlab and its performance was tested on several cervical cancer patients where cervix and bladder are connected with similar activity values. The positive predictive values (PPV) are calculated to characterize the segmentation accuracy of the proposed scheme. Results: Tumors were accurately segmented by the proposed method even when they are connected with bladder in the image with no difference in intensity. The average PPVs were 0.9571±0.0355 and 0.9894±0.0271 for 17 slices and 11 slices of PET from two patients, respectively. Conclusion: We have developed a new scheme to segment tumor in PET images for the special case that the tumor is quite similar to or connected to normal organs/tissues in the image. The proposed scheme can provide a reliable way for segmenting tumors.

  2. SU-C-207B-03: A Geometrical Constrained Chan-Vese Based Tumor Segmentation Scheme for PET

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L; Zhou, Z; Wang, J [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: Accurate segmentation of tumor in PET is challenging when part of tumor is connected with normal organs/tissues with no difference in intensity. Conventional segmentation methods, such as thresholding or region growing, cannot generate satisfactory results in this case. We proposed a geometrical constrained Chan-Vese based scheme to segment tumor in PET for this special case by considering the similarity between two adjacent slices. Methods: The proposed scheme performs segmentation in a slice-by-slice fashion where an accurate segmentation of one slice is used as the guidance for segmentation of rest slices. For a slice that the tumor is not directly connected to organs/tissues with similar intensity values, a conventional clustering-based segmentation method under user’s guidance is used to obtain an exact tumor contour. This is set as the initial contour and the Chan-Vese algorithm is applied for segmenting the tumor in the next adjacent slice by adding constraints of tumor size, position and shape information. This procedure is repeated until the last slice of PET containing tumor. The proposed geometrical constrained Chan-Vese based algorithm was implemented in Matlab and its performance was tested on several cervical cancer patients where cervix and bladder are connected with similar activity values. The positive predictive values (PPV) are calculated to characterize the segmentation accuracy of the proposed scheme. Results: Tumors were accurately segmented by the proposed method even when they are connected with bladder in the image with no difference in intensity. The average PPVs were 0.9571±0.0355 and 0.9894±0.0271 for 17 slices and 11 slices of PET from two patients, respectively. Conclusion: We have developed a new scheme to segment tumor in PET images for the special case that the tumor is quite similar to or connected to normal organs/tissues in the image. The proposed scheme can provide a reliable way for segmenting tumors.

  3. Recyclability of PET/WPI/PE Multilayer Films by Removal of Whey Protein Isolate-Based Coatings with Enzymatic Detergents

    Directory of Open Access Journals (Sweden)

    Patrizia Cinelli

    2016-06-01

    Full Text Available Multilayer plastic films provide a range of properties, which cannot be obtained from monolayer films but, at present, their recyclability is an open issue and should be improved. Research to date has shown the possibility of using whey protein as a layer material with the property of acting as an excellent barrier against oxygen and moisture, replacing petrochemical non-recyclable materials. The innovative approach of the present research was to achieve the recyclability of the substrate films by separating them, with a simple process compatible with industrial procedures, in order to promote recycling processes leading to obtain high value products that will beneficially impact the packaging and food industries. Hence, polyethyleneterephthalate (PET/polyethylene (PE multi-layer film was prepared based on PET coated with a whey protein layer, and then the previous structure was laminated with PE. Whey proteins, constituting the coating, can be degraded by enzymes so that the coating films can be washed off from the plastic substrate layer. Enzyme types, dosage, time, and temperature optima, which are compatible with procedures adopted in industrial waste recycling, were determined for a highly-efficient process. The washing of samples based on PET/whey and PET/whey/PE were efficient when performed with enzymatic detergent containing protease enzymes, as an alternative to conventional detergents used in recycling facilities. Different types of enzymatic detergents tested presented positive results in removing the protein layer from the PET substrate and from the PET/whey/PE multilayer films at room temperature. These results attested to the possibility of organizing the pre-treatment of the whey-based multilayer film by washing with different available commercial enzymatic detergents in order to separate PET and PE, thus allowing a better recycling of the two different polymers. Mechanical properties of the plastic substrate, such as stress at

  4. Recyclability of PET/WPI/PE Multilayer Films by Removal of Whey Protein Isolate-Based Coatings with Enzymatic Detergents

    Science.gov (United States)

    Cinelli, Patrizia; Schmid, Markus; Bugnicourt, Elodie; Coltelli, Maria Beatrice; Lazzeri, Andrea

    2016-01-01

    Multilayer plastic films provide a range of properties, which cannot be obtained from monolayer films but, at present, their recyclability is an open issue and should be improved. Research to date has shown the possibility of using whey protein as a layer material with the property of acting as an excellent barrier against oxygen and moisture, replacing petrochemical non-recyclable materials. The innovative approach of the present research was to achieve the recyclability of the substrate films by separating them, with a simple process compatible with industrial procedures, in order to promote recycling processes leading to obtain high value products that will beneficially impact the packaging and food industries. Hence, polyethyleneterephthalate (PET)/polyethylene (PE) multi-layer film was prepared based on PET coated with a whey protein layer, and then the previous structure was laminated with PE. Whey proteins, constituting the coating, can be degraded by enzymes so that the coating films can be washed off from the plastic substrate layer. Enzyme types, dosage, time, and temperature optima, which are compatible with procedures adopted in industrial waste recycling, were determined for a highly-efficient process. The washing of samples based on PET/whey and PET/whey/PE were efficient when performed with enzymatic detergent containing protease enzymes, as an alternative to conventional detergents used in recycling facilities. Different types of enzymatic detergents tested presented positive results in removing the protein layer from the PET substrate and from the PET/whey/PE multilayer films at room temperature. These results attested to the possibility of organizing the pre-treatment of the whey-based multilayer film by washing with different available commercial enzymatic detergents in order to separate PET and PE, thus allowing a better recycling of the two different polymers. Mechanical properties of the plastic substrate, such as stress at yield, stress and

  5. Partial volume effect correction in PET using regularized iterative deconvolution with variance control based on local topology

    International Nuclear Information System (INIS)

    Kirov, A S; Schmidtlein, C R; Piao, J Z

    2008-01-01

    Correcting positron emission tomography (PET) images for the partial volume effect (PVE) due to the limited resolution of PET has been a long-standing challenge. Various approaches including incorporation of the system response function in the reconstruction have been previously tested. We present a post-reconstruction PVE correction based on iterative deconvolution using a 3D maximum likelihood expectation-maximization (MLEM) algorithm. To achieve convergence we used a one step late (OSL) regularization procedure based on the assumption of local monotonic behavior of the PET signal following Alenius et al. This technique was further modified to selectively control variance depending on the local topology of the PET image. No prior 'anatomic' information is needed in this approach. An estimate of the noise properties of the image is used instead. The procedure was tested for symmetric and isotropic deconvolution functions with Gaussian shape and full width at half-maximum (FWHM) ranging from 6.31 mm to infinity. The method was applied to simulated and experimental scans of the NEMA NU 2 image quality phantom with the GE Discovery LS PET/CT scanner. The phantom contained uniform activity spheres with diameters ranging from 1 cm to 3.7 cm within uniform background. The optimal sphere activity to variance ratio was obtained when the deconvolution function was replaced by a step function few voxels wide. In this case, the deconvolution method converged in ∼3-5 iterations for most points on both the simulated and experimental images. For the 1 cm diameter sphere, the contrast recovery improved from 12% to 36% in the simulated and from 21% to 55% in the experimental data. Recovery coefficients between 80% and 120% were obtained for all larger spheres, except for the 13 mm diameter sphere in the simulated scan (68%). No increase in variance was observed except for a few voxels neighboring strong activity gradients and inside the largest spheres. Testing the method for

  6. The efflux of choline from nerve cells: mediation by ionic gradients and functional exchange of choline from glia to neurons

    International Nuclear Information System (INIS)

    Hoffmann, D.; Ferret, B.; Massarelli, R.; Mykita, S.

    1986-01-01

    This paper analyzes the relationship between ions and the efflux of choline, and suggests the possibility of a balance effect for choline fluxes which is produced and maintained by ioinic gradients. It is also suggested that glial cells may actively exchange choline with neurons during nerve actively exchange choline with neurons during nerve activity, and that they may function as a choline reservoir for neuronal needs. The study shows that neurons and glial cells spontaneously discharge choline into the incubation medium. The exiting choline is essentially of free origin, as can be seen in an illustration provided. Neurons and glial cells had been prelabelled with ( 14 C) choline overnight, and labelled for 15 min with tritium-choline. The higher amount of tritium-choline exiting the cells indicates that it is the freshly labelled choline which is preferentially released. The remaining of ( 14 C) - choline exiting the cells corresponds to the free choline of phospholipid origin which amounts to about one third of the total free choline content

  7. NEMA NU 2-2012 performance studies for the SiPM-based ToF-PET component of the GE SIGNA PET/MR system

    Energy Technology Data Exchange (ETDEWEB)

    Grant, Alexander M. [Department of Bioengineering, Stanford University, Stanford, California 94305-5128 and Department of Radiology, Stanford University, Stanford, California 94305-5128 (United States); Deller, Timothy W.; Maramraju, Sri Harsha [GE Healthcare, Waukesha, Wisconsin 53188-1678 (United States); Khalighi, Mohammad Mehdi [GE Healthcare, Applied Science Lab, Menlo Park, California 94025-3493 (United States); Delso, Gaspar [GE Healthcare and University Hospital of Zurich, Zurich 8006 (Switzerland); Levin, Craig S., E-mail: cslevin@stanford.edu [Department of Bioengineering, Stanford University, Stanford, California 94305-5128 (United States); Department of Radiology, Stanford University, Stanford, California 94305-5128 (United States); Department of Electrical Engineering, Stanford University, Stanford, California 94305-5128 (United States); Department of Physics, Stanford University, Stanford, California 94305-5128 (United States)

    2016-05-15

    Purpose: The GE SIGNA PET/MR is a new whole body integrated time-of-flight (ToF)-PET/MR scanner from GE Healthcare. The system is capable of simultaneous PET and MR image acquisition with sub-400 ps coincidence time resolution. Simultaneous PET/MR holds great potential as a method of interrogating molecular, functional, and anatomical parameters in clinical disease in one study. Despite the complementary imaging capabilities of PET and MRI, their respective hardware tends to be incompatible due to mutual interference. In this work, the GE SIGNA PET/MR is evaluated in terms of PET performance and the potential effects of interference from MRI operation. Methods: The NEMA NU 2-2012 protocol was followed to measure PET performance parameters including spatial resolution, noise equivalent count rate, sensitivity, accuracy, and image quality. Each of these tests was performed both with the MR subsystem idle and with continuous MR pulsing for the duration of the PET data acquisition. Most measurements were repeated at three separate test sites where the system is installed. Results: The scanner has achieved an average of 4.4, 4.1, and 5.3 mm full width at half maximum radial, tangential, and axial spatial resolutions, respectively, at 1 cm from the transaxial FOV center. The peak noise equivalent count rate (NECR) of 218 kcps and a scatter fraction of 43.6% are reached at an activity concentration of 17.8 kBq/ml. Sensitivity at the center position is 23.3 cps/kBq. The maximum relative slice count rate error below peak NECR was 3.3%, and the residual error from attenuation and scatter corrections was 3.6%. Continuous MR pulsing had either no effect or a minor effect on each measurement. Conclusions: Performance measurements of the ToF-PET whole body GE SIGNA PET/MR system indicate that it is a promising new simultaneous imaging platform.

  8. NEMA NU 2-2012 performance studies for the SiPM-based ToF-PET component of the GE SIGNA PET/MR system

    International Nuclear Information System (INIS)

    Grant, Alexander M.; Deller, Timothy W.; Maramraju, Sri Harsha; Khalighi, Mohammad Mehdi; Delso, Gaspar; Levin, Craig S.

    2016-01-01

    Purpose: The GE SIGNA PET/MR is a new whole body integrated time-of-flight (ToF)-PET/MR scanner from GE Healthcare. The system is capable of simultaneous PET and MR image acquisition with sub-400 ps coincidence time resolution. Simultaneous PET/MR holds great potential as a method of interrogating molecular, functional, and anatomical parameters in clinical disease in one study. Despite the complementary imaging capabilities of PET and MRI, their respective hardware tends to be incompatible due to mutual interference. In this work, the GE SIGNA PET/MR is evaluated in terms of PET performance and the potential effects of interference from MRI operation. Methods: The NEMA NU 2-2012 protocol was followed to measure PET performance parameters including spatial resolution, noise equivalent count rate, sensitivity, accuracy, and image quality. Each of these tests was performed both with the MR subsystem idle and with continuous MR pulsing for the duration of the PET data acquisition. Most measurements were repeated at three separate test sites where the system is installed. Results: The scanner has achieved an average of 4.4, 4.1, and 5.3 mm full width at half maximum radial, tangential, and axial spatial resolutions, respectively, at 1 cm from the transaxial FOV center. The peak noise equivalent count rate (NECR) of 218 kcps and a scatter fraction of 43.6% are reached at an activity concentration of 17.8 kBq/ml. Sensitivity at the center position is 23.3 cps/kBq. The maximum relative slice count rate error below peak NECR was 3.3%, and the residual error from attenuation and scatter corrections was 3.6%. Continuous MR pulsing had either no effect or a minor effect on each measurement. Conclusions: Performance measurements of the ToF-PET whole body GE SIGNA PET/MR system indicate that it is a promising new simultaneous imaging platform.

  9. Evaluation of two population-based input functions for quantitative neurological FDG PET studies

    International Nuclear Information System (INIS)

    Eberl, S.; Anayat, A.R.; Fulton, R.R.; Hooper, P.K.; Fulham, M.J.

    1997-01-01

    The conventional measurement of the regional cerebral metabolic rate of glucose (rCMRGlc) with fluorodexoyglucose (FDG) and positron emission tomography (PET) requires arterial or arterialised-venous (a-v) blood sampling at frequent intervals to obtain the plasma input function (IF). We evaluated the accuracy of rCMRGlc measurements using population-based IFs that were calibrated with two a-v blood samples. Population-based IFs were derived from: (1) the average of a-v IFs from 26 patients (Standard IF) and (2) a published model of FDG plasma concentration (Feng IF). Values for rCMRGlc calculated from the population-based IFs were compared with values obtained with IFs derived from frequent a-v blood sampling in 20 non-diabetic and six diabetic patients. Values for rCMRGlc calculated with the different IFs were highly correlated for both patient groups (r≥0.992) and root mean square residuals about the regression line were less than 0.24 mg/min/100 g. The Feng IF tended to underestimate high rCMRGlc. Both population-based IFs simplify the measurement of rCMRGlc with minimal loss in accuracy and require only two a-v blood samples for calibration. The reduced blood sampling requirements markedly reduce radiation exposure to the blood sampler. (orig.)

  10. A prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer

    International Nuclear Information System (INIS)

    Leong, Trevor; Everitt, Craig; Yuen, Kally; Condron, Sara; Hui, Andrew; Ngan, Samuel Y.K.; Pitman, Alexander; Lau, Eddie W.F.; MacManus, Michael; Binns, David; Ackerly, Trevor; Hicks, Rodney J.

    2006-01-01

    Background and purpose: This prospective study sought to determine how the use of combined PET/CT for radiotherapy treatment planning of oesophageal cancer would alter the delineation of tumour volumes compared to CT alone if PET/CT is assumed to more accurately represent true disease extent. Patients and methods: All patients underwent FDG-PET/CT scanning in the radiotherapy treatment position. For each patient, two separate gross tumour volumes (GTV) were defined, one based on CT images alone (GTV-CT) and another based on combined PET/CT data (GTV-PET). Corresponding planning target volumes (PTV) were generated, and separate treatment plans were then produced. For each patient, volumetric analysis of GTV-CT, PTV-CT and GTV-PET was performed to quantify the proportion of PET-avid disease that was not included in the GTV and PTV (geographic miss) if CT data alone were used for radiotherapy planning. Assessment of the cranial and caudal extent of the primary oesophageal tumour as defined by CT alone vs PET/CT was also compared. Results: The addition of PET information altered the clinical stage in 8 of 21 eligible patients enrolled on the study (38%); 4 patients had distant metastatic disease and 4 had unsuspected regional nodal disease. Sixteen patients proceeded to the radiotherapy planning phase of the study and received definitive chemoradiation planned with the PET/CT data set. The GTV based on CT information alone excluded PET-avid disease in 11 patients (69%), and in five patients (31%) this would have resulted in a geographic miss of gross tumour. The discordance between CT and PET/CT was due mainly to differences in defining the longitudinal extent of disease in the oesophagus. The cranial extent of the primary tumour as defined by CT vs PET/CT differed in 75% of cases, while the caudal extent differed in 81%. Conclusions: This study demonstrates that if combined PET/CT is used for radiotherapy treatment planning, there may be alterations to the delineation

  11. Preprocessing of 18F-DMFP-PET Data Based on Hidden Markov Random Fields and the Gaussian Distribution

    Directory of Open Access Journals (Sweden)

    Fermín Segovia

    2017-10-01

    Full Text Available 18F-DMFP-PET is an emerging neuroimaging modality used to diagnose Parkinson's disease (PD that allows us to examine postsynaptic dopamine D2/3 receptors. Like other neuroimaging modalities used for PD diagnosis, most of the total intensity of 18F-DMFP-PET images is concentrated in the striatum. However, other regions can also be useful for diagnostic purposes. An appropriate delimitation of the regions of interest contained in 18F-DMFP-PET data is crucial to improve the automatic diagnosis of PD. In this manuscript we propose a novel methodology to preprocess 18F-DMFP-PET data that improves the accuracy of computer aided diagnosis systems for PD. First, the data were segmented using an algorithm based on Hidden Markov Random Field. As a result, each neuroimage was divided into 4 maps according to the intensity and the neighborhood of the voxels. The maps were then individually normalized so that the shape of their histograms could be modeled by a Gaussian distribution with equal parameters for all the neuroimages. This approach was evaluated using a dataset with neuroimaging data from 87 parkinsonian patients. After these preprocessing steps, a Support Vector Machine classifier was used to separate idiopathic and non-idiopathic PD. Data preprocessed by the proposed method provided higher accuracy results than the ones preprocessed with previous approaches.

  12. Geographic Distribution of CT, MRI and PET Devices in Japan: A Longitudinal Analysis Based on National Census Data.

    Science.gov (United States)

    Matsumoto, Masatoshi; Koike, Soichi; Kashima, Saori; Awai, Kazuo

    2015-01-01

    Japan has the most CT and MRI scanners per unit population in the world; however, the geographic distribution of these technologies is currently unknown. Moreover, nothing is known of the cause-effect relationship between the number of diagnostic imaging devices and their geographic distribution. Data on the number of CT, MRI and PET devices and that of their utilizations in all 1829 municipalities of Japan was generated, based on the Static Survey of Medical Institutions conducted by the government. The inter-municipality equity of the number of devices or utilizations was evaluated with Gini coefficient. Between 2005 and 2011, the number of CT, MRI and PET devices in Japan increased by 47% (8789 to 12945), 19% (5034 to 5990) and 70% (274 to 466), respectively. Gini coefficient of the number of devices was largest for PET and smallest for CT (p for PET-MRI difference geographic distribution of the diagnostic imaging technology in Japan appears to be affected by spatial competition derived from a market force.

  13. TU-AB-202-11: Tumor Segmentation by Fusion of Multi-Tracer PET Images Using Copula Based Statistical Methods

    International Nuclear Information System (INIS)

    Lapuyade-Lahorgue, J; Ruan, S; Li, H; Vera, P

    2016-01-01

    Purpose: Multi-tracer PET imaging is getting more attention in radiotherapy by providing additional tumor volume information such as glucose and oxygenation. However, automatic PET-based tumor segmentation is still a very challenging problem. We propose a statistical fusion approach to joint segment the sub-area of tumors from the two tracers FDG and FMISO PET images. Methods: Non-standardized Gamma distributions are convenient to model intensity distributions in PET. As a serious correlation exists in multi-tracer PET images, we proposed a new fusion method based on copula which is capable to represent dependency between different tracers. The Hidden Markov Field (HMF) model is used to represent spatial relationship between PET image voxels and statistical dynamics of intensities for each modality. Real PET images of five patients with FDG and FMISO are used to evaluate quantitatively and qualitatively our method. A comparison between individual and multi-tracer segmentations was conducted to show advantages of the proposed fusion method. Results: The segmentation results show that fusion with Gaussian copula can receive high Dice coefficient of 0.84 compared to that of 0.54 and 0.3 of monomodal segmentation results based on individual segmentation of FDG and FMISO PET images. In addition, high correlation coefficients (0.75 to 0.91) for the Gaussian copula for all five testing patients indicates the dependency between tumor regions in the multi-tracer PET images. Conclusion: This study shows that using multi-tracer PET imaging can efficiently improve the segmentation of tumor region where hypoxia and glucidic consumption are present at the same time. Introduction of copulas for modeling the dependency between two tracers can simultaneously take into account information from both tracers and deal with two pathological phenomena. Future work will be to consider other families of copula such as spherical and archimedian copulas, and to eliminate partial volume

  14. Chronic Liver Disease and the Detection of Hepatocellular Carcinoma by [18F]fluorocholine PET/CT

    Directory of Open Access Journals (Sweden)

    Sandi A. Kwee

    2015-05-01

    Full Text Available Positron emission tomography (PET using the radiopharmaceutical tracer fluorine-18 fluorocholine (FCh can elucidate tumors based on differences in choline phospholipid metabolism between tumor and surrounding tissue. The feasibility of detecting hepatocellular carcinoma (HCC using FCh PET has been shown despite constitutively high parenchymal choline metabolism in the liver. Since HCC frequently develops in the setting of chronic liver disease, we comparatively evaluated FCh PET/CT between cirrhotic and non-cirrhotic patients with HCC to investigate the effects of hepatic dysfunction on tumor detection and the tumor-to-background ratio (TBR of FCh uptake. FCh PET/CT was performed prospectively in 22 consecutive patients with HCC (7 newly diagnosed, 15 previously treated. Of these 22 patients, 14 were cirrhotic and 8 non-cirrhotic. Standardized uptake value (SUV measurements were obtained by region of interest analysis of the PET images. Tumor FCh uptake and the TBR were compared between cirrhotic and non-cirrhotic patients. Liver lesions were confirmed to be HCC by biopsy in 10 patients and by Barcelona criteria in 4 patients. There was correspondingly increased liver tumor FCh uptake in 13/14 of those patients, and iso-intense tumor FCh uptake (TBR 0.94 in one non-cirrhotic patient with newly diagnosed HCC. FCh PET/CT also showed metastatic disease without local tumor recurrence in 2 previously treated patients, and was negative in 6 treated patients without tumor recurrence by radiographic and clinical follow-up. Tumor maximum SUV ranged from 6.4 to 15.3 (mean 12.1 and liver TBR ranged from 0.94 to 2.1 (mean 1.6, with no significant differences between cirrhotic and non-cirrhotic patients (SUVmax 11.9 vs. 12.2, p = 0.83; TBR 1.71 vs. 1.51, p = 0.29. Liver parenchyma mean SUV was significantly lower in cirrhotic patients (6.4 vs. 8.7, p < 0.05. This pilot study supports the general feasibility of HCC detection by FCh PET/CT. However, a broad

  15. A knowledge-based method for reducing attenuation artefacts caused by cardiac appliances in myocardial PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Hamill, James J [Siemens Medical Solutions, Molecular Imaging, 810 Innovation Dr., Knoxville, TN (United States); Brunken, Richard C [Department of Molecular and Functional Imaging, Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH (United States); Bybel, Bohdan [Department of Molecular and Functional Imaging, Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH (United States); DiFilippo, Frank P [Department of Molecular and Functional Imaging, Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH (United States); Faul, David D [Siemens Medical Solutions, Molecular Imaging, 810 Innovation Dr., Knoxville, TN (United States)

    2006-06-07

    Attenuation artefacts due to implanted cardiac defibrillator leads have previously been shown to adversely impact cardiac PET/CT imaging. In this study, the severity of the problem is characterized, and an image-based method is described which reduces the resulting artefact in PET. Automatic implantable cardioverter defibrillator (AICD) leads cause a moving-metal artefact in the CT sections from which the PET attenuation correction factors (ACFs) are derived. Fluoroscopic cine images were measured to demonstrate that the defibrillator's highly attenuating distal shocking coil moves rhythmically across distances on the order of 1 cm. Rhythmic motion of this magnitude was created in a phantom with a moving defibrillator lead. A CT study of the phantom showed that the artefact contained regions of incorrect, very high CT values and adjacent regions of incorrect, very low CT values. The study also showed that motion made the artefact more severe. A knowledge-based metal artefact reduction method (MAR) is described that reduces the magnitude of the error in the CT images, without use of the corrupted sinograms. The method modifies the corrupted image through a sequence of artefact detection procedures, morphological operations, adjustments of CT values and three-dimensional filtering. The method treats bone the same as metal. The artefact reduction method is shown to run in a few seconds, and is validated by applying it to a series of phantom studies in which reconstructed PET tracer distribution values are wrong by as much as 60% in regions near the CT artefact when MAR is not applied, but the errors are reduced to about 10% of expected values when MAR is applied. MAR changes PET image values by a few per cent in regions not close to the artefact. The changes can be larger in the vicinity of bone. In patient studies, the PET reconstruction without MAR sometimes results in anomalously high values in the infero-septal wall. Clinical performance of MAR is assessed by

  16. A knowledge-based method for reducing attenuation artefacts caused by cardiac appliances in myocardial PET/CT

    International Nuclear Information System (INIS)

    Hamill, James J; Brunken, Richard C; Bybel, Bohdan; DiFilippo, Frank P; Faul, David D

    2006-01-01

    Attenuation artefacts due to implanted cardiac defibrillator leads have previously been shown to adversely impact cardiac PET/CT imaging. In this study, the severity of the problem is characterized, and an image-based method is described which reduces the resulting artefact in PET. Automatic implantable cardioverter defibrillator (AICD) leads cause a moving-metal artefact in the CT sections from which the PET attenuation correction factors (ACFs) are derived. Fluoroscopic cine images were measured to demonstrate that the defibrillator's highly attenuating distal shocking coil moves rhythmically across distances on the order of 1 cm. Rhythmic motion of this magnitude was created in a phantom with a moving defibrillator lead. A CT study of the phantom showed that the artefact contained regions of incorrect, very high CT values and adjacent regions of incorrect, very low CT values. The study also showed that motion made the artefact more severe. A knowledge-based metal artefact reduction method (MAR) is described that reduces the magnitude of the error in the CT images, without use of the corrupted sinograms. The method modifies the corrupted image through a sequence of artefact detection procedures, morphological operations, adjustments of CT values and three-dimensional filtering. The method treats bone the same as metal. The artefact reduction method is shown to run in a few seconds, and is validated by applying it to a series of phantom studies in which reconstructed PET tracer distribution values are wrong by as much as 60% in regions near the CT artefact when MAR is not applied, but the errors are reduced to about 10% of expected values when MAR is applied. MAR changes PET image values by a few per cent in regions not close to the artefact. The changes can be larger in the vicinity of bone. In patient studies, the PET reconstruction without MAR sometimes results in anomalously high values in the infero-septal wall. Clinical performance of MAR is assessed by two

  17. Arterial spin labeling-based Z-maps have high specificity and positive predictive value for neurodegenerative dementia compared to FDG-PET

    Energy Technology Data Exchange (ETDEWEB)

    Faellmar, David; Larsson, Elna-Marie [Uppsala University, Department of Surgical Sciences, Radiology, Uppsala (Sweden); Haller, Sven [Uppsala University, Department of Surgical Sciences, Radiology, Uppsala (Sweden); University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); University of Geneva, Faculty of Medicine, Geneva (Switzerland); Affidea CDRC - Centre Diagnostique Radiologique de Carouge, Carouge (Switzerland); Lilja, Johan [Uppsala University, Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala (Sweden); Hermes Medical Solutions, Stockholm (Sweden); Danfors, Torsten [Uppsala University, Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala (Sweden); Kilander, Lena [Uppsala University, Department of Public Health and Caring Sciences, Geriatrics, Uppsala (Sweden); Tolboom, Nelleke; Croon, Philip M.; Berckel, Bart N.M. van [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Egger, Karl [University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); Kellner, Elias [Medical Center University of Freiburg, Department of Radiology, Medical Physics, Faculty of Medicine, Freiburg (Germany); Verfaillie, Sander C.J.; Ossenkoppele, Rik [VU University Medical Center, Department of Neurology, Alzheimer Center Amsterdam, Amsterdam (Netherlands); Barkhof, Frederik [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); UCL, Institutes of Neurology and Healthcare Engineering, London (United Kingdom)

    2017-10-15

    Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level. This study aimed to compare the performance of Z-maps based on ASL to FDG-PET. Data were combined from two separate sites, each cohort consisting of patients with Alzheimer's disease (n = 18 + 7), frontotemporal dementia (n = 12 + 8) and controls (n = 9 + 29). Subjects underwent pseudocontinuous ASL and FDG-PET. Z-maps were created for each subject and modality. Four experienced physicians visually assessed the 166 Z-maps in random order, blinded to modality and diagnosis. Discrimination of patients versus controls using ASL-based Z-maps yielded high specificity (84%) and positive predictive value (80%), but significantly lower sensitivity compared to FDG-PET-based Z-maps (53% vs. 96%, p < 0.001). Among true-positive cases, correct diagnoses were made in 76% (ASL) and 84% (FDG-PET) (p = 0.168). ASL-based Z-maps can be used for visual assessment of neurodegenerative dementia with high specificity and positive predictive value, but with inferior sensitivity compared to FDG-PET. (orig.)

  18. Lung PET scan

    Science.gov (United States)

    ... Chest PET scan; Lung positron emission tomography; PET - chest; PET - lung; PET - tumor imaging; ... Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. Philadelphia, ...

  19. PET/MRI for Oncologic Brain Imaging: A Comparison of Standard MR-Based Attenuation Corrections with a Model-Based Approach for the Siemens mMR PET/MR System.

    Science.gov (United States)

    Rausch, Ivo; Rischka, Lucas; Ladefoged, Claes N; Furtner, Julia; Fenchel, Matthias; Hahn, Andreas; Lanzenberger, Rupert; Mayerhoefer, Marius E; Traub-Weidinger, Tatjana; Beyer, Thomas

    2017-09-01

    The aim of this study was to compare attenuation-correction (AC) approaches for PET/MRI in clinical neurooncology. Methods: Forty-nine PET/MRI brain scans were included: brain tumor studies using 18 F-fluoro-ethyl-tyrosine ( 18 F-FET) ( n = 31) and 68 Ga-DOTANOC ( n = 7) and studies of healthy subjects using 18 F-FDG ( n = 11). For each subject, MR-based AC maps (MR-AC) were acquired using the standard DIXON- and ultrashort echo time (UTE)-based approaches. A third MR-AC was calculated using a model-based, postprocessing approach to account for bone attenuation values (BD, noncommercial prototype software by Siemens Healthcare). As a reference, AC maps were derived from patient-specific CT images (CTref). PET data were reconstructed using standard settings after AC with all 4 AC methods. We report changes in diagnosis for all brain tumor patients and the following relative differences values (RDs [%]), with regards to AC-CTref: for 18 F-FET (A)-SUVs as well as volumes of interest (VOIs) defined by a 70% threshold of all segmented lesions and lesion-to-background ratios; for 68 Ga-DOTANOC (B)-SUVs as well as VOIs defined by a 50% threshold for all lesions and the pituitary gland; and for 18 F-FDG (C)-RD of SUVs of the whole brain and 10 anatomic regions segmented on MR images. Results: For brain tumor imaging (A and B), the standard PET-based diagnosis was not affected by any of the 3 MR-AC methods. For A, the average RDs of SUV mean were -10%, -4%, and -3% and of the VOIs 1%, 2%, and 7% for DIXON, UTE, and BD, respectively. Lesion-to-background ratios for all MR-AC methods were similar to that of CTref. For B, average RDs of SUV mean were -11%, -11%, and -3% and of the VOIs 1%, -4%, and -3%, respectively. In the case of 18 F-FDG PET/MRI (C), RDs for the whole brain were -11%, -8%, and -5% for DIXON, UTE, and BD, respectively. Conclusion: The diagnostic reading of PET/MR patients with brain tumors did not change with the chosen AC method. Quantitative accuracy of

  20. Utility evaluations for Markov states of lung cancer for PET-based disease management

    International Nuclear Information System (INIS)

    Papatheofanis, F.J.

    2000-01-01

    Utilities for the health outcomes states (Markov states) of non-small cell lung carcinoma (NSCLCL) should be measured to evaluate management options for patients because patients are key participants in the process of care, and their assessment of diagnostic and therapeutic value in the options presented to them ultimately impacts their net health outcomes. This investigation sought to measure utilities for stage-dependent outcomes states of NSCLC. Persons (n=23) with suspected NSCLC based on physical findings and computed tomography completed a short utilities survey. Utility valuations were obtained according to severity of morbidity and varied considerably. Respondents rated these health states according to accuracy measures for 18 flurodeoxyglucose ( 18 FDG) positron emission tomography (PET) imaging and mediastinoscopy. The results demonstrate that stage-dependent morbidity is an important consideration for patients with NSCLC and should be included in any decision analysis regarding the evaluation or treatment of NSCLC. Respondents valued the quality of information obtained from non-invasive mediastinoscopy comparably. The utilities obtained from this investigation are useful in clinical decision-making based on Markov processes because they provide an initial estimation of utility assessment for 18 FDG-based diagnostic evaluation of lung cancer. Consequently, these utilities will be useful in future decision analyses that require patient preference in the assignment of the evaluation of decision options (branches)

  1. A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators.

    Science.gov (United States)

    Du, Junwei; Schmall, Jeffrey P; Judenhofer, Martin S; Di, Kun; Yang, Yongfeng; Cherry, Simon R

    2017-09-01

    The leading edge timing pick-off technique is the simplest timing extraction method for PET detectors. Due to the inherent time-walk of the leading edge technique, corrections should be made to improve timing resolution, especially for time-of-flight PET. Time-walk correction can be done by utilizing the relationship between the threshold crossing time and the event energy on an event by event basis. In this paper, a time-walk correction method is proposed and evaluated using timing information from two identical detectors both using leading edge discriminators. This differs from other techniques that use an external dedicated reference detector, such as a fast PMT-based detector using constant fraction techniques to pick-off timing information. In our proposed method, one detector was used as reference detector to correct the time-walk of the other detector. Time-walk in the reference detector was minimized by using events within a small energy window (508.5 - 513.5 keV). To validate this method, a coincidence detector pair was assembled using two SensL MicroFB SiPMs and two 2.5 mm × 2.5 mm × 20 mm polished LYSO crystals. Coincidence timing resolutions using different time pick-off techniques were obtained at a bias voltage of 27.5 V and a fixed temperature of 20 °C. The coincidence timing resolution without time-walk correction were 389.0 ± 12.0 ps (425 -650 keV energy window) and 670.2 ± 16.2 ps (250-750 keV energy window). The timing resolution with time-walk correction improved to 367.3 ± 0.5 ps (425 - 650 keV) and 413.7 ± 0.9 ps (250 - 750 keV). For comparison, timing resolutions were 442.8 ± 12.8 ps (425 - 650 keV) and 476.0 ± 13.0 ps (250 - 750 keV) using constant fraction techniques, and 367.3 ± 0.4 ps (425 - 650 keV) and 413.4 ± 0.9 ps (250 - 750 keV) using a reference detector based on the constant fraction technique. These results show that the proposed leading edge based time-walk correction method works well. Timing resolution obtained

  2. Imaging performance of a full-ring prototype PET-MRI system based on four-layer DOI-PET detectors integrated with a RF coil

    Energy Technology Data Exchange (ETDEWEB)

    Nishikido, Fumihiko; Tashima, Hideaki [National Institute of Radiological Sciences, Chiba (Japan); Suga, Mikio [Chiba University, Chiba (Japan); Inadama, Naoko; Eiji, Yoshida; Obata, Takayuki; Yamaya, Taiga [National Institute of Radiological Sciences, Chiba (Japan)

    2015-05-18

    We are developing a PET system integrated with a birdcage RF-coil for PET-MRI in order to realize both high sensitivity and high spatial resolution of the PET image by using the 4-layered depth-of-interaction (DOI) PET detector. We constructed a full-ring prototype system and evaluated performances, especially imaging performance, of the prototype system in simultaneous measurement. The prototype system consists of eight four-layer DOI-PET detectors and a prototype birdcage RF-coil developed for the proposed system. The PET detectors consist of six monolithic multi-pixel photon counter array (S11064-050P), a readout circuit, fourlayer DOI scintillator arrays and a shielding box made of 35 μm thick copper foil. The crystal array consists of 2.0 mm x 2.0 mm x 5.0 mm LYSO crystals arranged in 38 x 6 x 4 layer. The RF-coil has eight coil elements and the eight PET detectors are positioned at each element gap. The diameter of the RF-coil elements is 261 mm. We conducted performance tests of the prototype system with a 3.0 T MRI (MAGNETOM Verio). Only the PET detectors, the RF-coil and the cables were in an MRI room during measurements. A data acquisition system and power supplies for the MPPCs and preamplifiers were outside the MRI room and connected to all the detectors through a penetration panel. As a result, the spatial resolutions of a Na-22 point source in the PET image were lower than 1.6 mm in whole the FOV due to the DOI capability. In addition, the influence of the simultaneous measurements on the PET performance is negligible. On the other hand, the SNR of the phantom image in the magnitude images was degraded from 259.7 to 209.4 due to noise contamination from the power supplies.

  3. Imaging performance of a full-ring prototype PET-MRI system based on four-layer DOI-PET detectors integrated with a RF coil

    International Nuclear Information System (INIS)

    Nishikido, Fumihiko; Tashima, Hideaki; Suga, Mikio; Inadama, Naoko; Eiji, Yoshida; Obata, Takayuki; Yamaya, Taiga

    2015-01-01

    We are developing a PET system integrated with a birdcage RF-coil for PET-MRI in order to realize both high sensitivity and high spatial resolution of the PET image by using the 4-layered depth-of-interaction (DOI) PET detector. We constructed a full-ring prototype system and evaluated performances, especially imaging performance, of the prototype system in simultaneous measurement. The prototype system consists of eight four-layer DOI-PET detectors and a prototype birdcage RF-coil developed for the proposed system. The PET detectors consist of six monolithic multi-pixel photon counter array (S11064-050P), a readout circuit, fourlayer DOI scintillator arrays and a shielding box made of 35 μm thick copper foil. The crystal array consists of 2.0 mm x 2.0 mm x 5.0 mm LYSO crystals arranged in 38 x 6 x 4 layer. The RF-coil has eight coil elements and the eight PET detectors are positioned at each element gap. The diameter of the RF-coil elements is 261 mm. We conducted performance tests of the prototype system with a 3.0 T MRI (MAGNETOM Verio). Only the PET detectors, the RF-coil and the cables were in an MRI room during measurements. A data acquisition system and power supplies for the MPPCs and preamplifiers were outside the MRI room and connected to all the detectors through a penetration panel. As a result, the spatial resolutions of a Na-22 point source in the PET image were lower than 1.6 mm in whole the FOV due to the DOI capability. In addition, the influence of the simultaneous measurements on the PET performance is negligible. On the other hand, the SNR of the phantom image in the magnitude images was degraded from 259.7 to 209.4 due to noise contamination from the power supplies.

  4. What Is the Best Way to Contour Lung Tumors on PET Scans? Multiobserver Validation of a Gradient-Based Method Using a NSCLC Digital PET Phantom

    International Nuclear Information System (INIS)

    Werner-Wasik, Maria; Nelson, Arden D.; Choi, Walter; Arai, Yoshio; Faulhaber, Peter F.; Kang, Patrick; Almeida, Fabio D.; Xiao, Ying; Ohri, Nitin; Brockway, Kristin D.; Piper, Jonathan W.; Nelson, Aaron S.

    2012-01-01

    Purpose: To evaluate the accuracy and consistency of a gradient-based positron emission tomography (PET) segmentation method, GRADIENT, compared with manual (MANUAL) and constant threshold (THRESHOLD) methods. Methods and Materials: Contouring accuracy was evaluated with sphere phantoms and clinically realistic Monte Carlo PET phantoms of the thorax. The sphere phantoms were 10–37 mm in diameter and were acquired at five institutions emulating clinical conditions. One institution also acquired a sphere phantom with multiple source-to-background ratios of 2:1, 5:1, 10:1, 20:1, and 70:1. One observer segmented (contoured) each sphere with GRADIENT and THRESHOLD from 25% to 50% at 5% increments. Subsequently, seven physicians segmented 31 lesions (7–264 mL) from 25 digital thorax phantoms using GRADIENT, THRESHOLD, and MANUAL. Results: For spheres 20 mm (p < 0.065) and <20 mm (p < 0.015). For digital thorax phantoms, GRADIENT was the most accurate (p < 0.01), with a mean absolute % error in volume of 10.99% (11.9% SD), followed by 25% THRESHOLD at 17.5% (29.4% SD), and MANUAL at 19.5% (17.2% SD). GRADIENT had the least systematic bias, with a mean % error in volume of –0.05% (16.2% SD) compared with 25% THRESHOLD at –2.1% (34.2% SD) and MANUAL at –16.3% (20.2% SD; p value <0.01). Interobserver variability was reduced using GRADIENT compared with both 25% THRESHOLD and MANUAL (p value <0.01, Levene’s test). Conclusion: GRADIENT was the most accurate and consistent technique for target volume contouring. GRADIENT was also the most robust for varying imaging conditions. GRADIENT has the potential to play an important role for tumor delineation in radiation therapy planning and response assessment.

  5. Longitudinal studies of the 18F-FDG kinetics after ipilimumab treatment in metastatic melanoma patients based on dynamic FDG PET/CT.

    Science.gov (United States)

    Sachpekidis, Christos; Anwar, Hoda; Winkler, Julia K; Kopp-Schneider, Annette; Larribere, Lionel; Haberkorn, Uwe; Hassel, Jessica C; Dimitrakopoulou-Strauss, Antonia

    2018-06-05

    Immunotherapy has raised the issue of appropriate treatment response evaluation, due to the unique mechanism of action of the immunotherapeutic agents. Aim of this analysis is to evaluate the potential role of quantitative analysis of 2-deoxy-2-( 18 F)fluoro-D-glucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) data in monitoring of patients with metastatic melanoma undergoing ipilimumab therapy. 25 patients with unresectable metastatic melanoma underwent dynamic PET/CT (dPET/CT) of the thorax and upper abdomen as well as static, whole body PET/CT with 18 F-FDG before the start of ipilimumab treatment (baseline PET/CT), after two cycles of treatment (interim PET/CT) and at the end of treatment after four cycles (late PET/CT). The evaluation of dPET/CT studies was based on semi-quantitative (standardized uptake value, SUV) calculation as well as quantitative analysis, based on two-tissue compartment modeling and a fractal approach. Patients' best clinical response, assessed at a mean of 59 weeks, was used as reference. According to their best clinical response, patients were dichotomized in those demonstrating clinical benefit (CB, n = 16 patients) and those demonstrating no clinical benefit (no-CB, n = 9 patients). No statistically significant differences were observed between CB and no-CB regarding either semi-quantitative or quantitative parameters in all scans. On contrary, the application of the recently introduced PET response evaluation criteria for immunotherapy (PERCIMT) led to a correct classification rate of 84% (21/25 patients). Quantitative analysis of 18 F-FDG PET data does not provide additional information in treatment response evaluation of metastatic melanoma patients receiving ipilimumab. PERCIMT criteria correlated better with clinical response.

  6. CHERENCUBE: Concept definition and implementation challenges of a Cherenkov-based detector block for PET

    International Nuclear Information System (INIS)

    Somlai-Schweiger, I.; Ziegler, S. I.

    2015-01-01

    Purpose: A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed “CHERENCUBE” consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimation is presented and the requirements for a practical implementation of the proposed concept are defined. Methods: The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm 3 and 10 × 10 × 10 mm 3 . For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO 4 . Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Results: Detection efficiency increases with crystal size from 8.2% (1 × 1

  7. Development of a circular shape Si-PM-based detector ring for breast-dedicated PET system

    Science.gov (United States)

    Nakanishi, Kouhei; Yamamoto, Seiichi; Watabe, Hiroshi; Abe, Shinji; Fujita, Naotoshi; Kato, Katsuhiko

    2018-02-01

    In clinical situations, various breast-dedicated positron emission tomography (PET) systems have been used. However, clinical breast-dedicated PET systems have polygonal detector ring. Polygonal detector ring sometimes causes image artifact, so complicated reconstruction algorithm is needed to reduce artifact. Consequently, we developed a circular detector ring for breast-dedicated PET to obtain images without artifact using a simple reconstruction algorithm. We used Lu1.9Gd0.1SiO5 (LGSO) scintillator block which was made of 1.5 x 1.9 x 15 mm pixels that were arranged in an 8 x 24 matrix. As photodetectors, we used silicon photomultiplier (Si-PM) arrays whose channel size was 3 x 3 mm. A detector unit was composed of four scintillator blocks, 16 Si-PM arrays and a light guide. The developed detector unit had angled configuration since the light guide was bending. A detector unit had three gaps with an angle of 5.625° between scintillator blocks. With these configurations, we could arrange 64 scintillator blocks in nearly circular shape (regular 64-sided polygon) using 16 detector units. The use of the smaller number of detector units could reduce the size of the front-end electronics circuits. The inner diameter of the developed detector ring was 260 mm. This size was similar to those of brain PET systems, so our breast-dedicated PET detector ring can measure not only breast but also brain. Measured radial, tangential and axial spatial resolution of the detector ring reconstructed by the filtered back-projection (FBP) algorithm were 2.1 mm FWHM, 2.0 mm FWHM and 1.7 mm FWHM at center of field of view (FOV), respectively. The sensitivity was 2.0% at center of the axial FOV. With the developed detector ring, we could obtain high resolution image of the breast phantom and the brain phantom. We conclude that our developed Si-PM-based detector ring is promising for a high resolution breast-dedicated PET system that can also be used for brain PET system.

  8. Impact of muscular uptake and statistical noise on tumor quantification based on simulated FDG-PET studies

    International Nuclear Information System (INIS)

    Silva-Rodríguez, Jesús; Domínguez-Prado, Inés; Pardo-Montero, Juan; Ruibal, Álvaro

    2017-01-01

    Purpose: The aim of this work is to study the effect of physiological muscular uptake variations and statistical noise on tumor quantification in FDG-PET studies. Methods: We designed a realistic framework based on simulated FDG-PET acquisitions from an anthropomorphic phantom that included different muscular uptake levels and three spherical lung lesions with diameters of 31, 21 and 9 mm. A distribution of muscular uptake levels was obtained from 136 patients remitted to our center for whole-body FDG-PET. Simulated FDG-PET acquisitions were obtained by using the Simulation System for Emission Tomography package (SimSET) Monte Carlo package. Simulated data was reconstructed by using an iterative Ordered Subset Expectation Maximization (OSEM) algorithm implemented in the Software for Tomographic Image Reconstruction (STIR) library. Tumor quantification was carried out by using estimations of SUV max , SUV 50 and SUV mean from different noise realizations, lung lesions and multiple muscular uptakes. Results: Our analysis provided quantification variability values of 17–22% (SUV max ), 11–19% (SUV 50 ) and 8–10% (SUV mean ) when muscular uptake variations and statistical noise were included. Meanwhile, quantification variability due only to statistical noise was 7–8% (SUV max ), 3–7% (SUV 50 ) and 1–2% (SUV mean ) for large tumors (>20 mm) and 13% (SUV max ), 16% (SUV 50 ) and 8% (SUV mean ) for small tumors (<10 mm), thus showing that the variability in tumor quantification is mainly affected by muscular uptake variations when large enough tumors are considered. In addition, our results showed that quantification variability is strongly dominated by statistical noise when the injected dose decreases below 222 MBq. Conclusions: Our study revealed that muscular uptake variations between patients who are totally relaxed should be considered as an uncertainty source of tumor quantification values. - Highlights: • Distribution of muscular uptake from 136 PET

  9. Selected PET radiomic features remain the same.

    Science.gov (United States)

    Tsujikawa, Tetsuya; Tsuyoshi, Hideaki; Kanno, Masafumi; Yamada, Shizuka; Kobayashi, Masato; Narita, Norihiko; Kimura, Hirohiko; Fujieda, Shigeharu; Yoshida, Yoshio; Okazawa, Hidehiko

    2018-04-17

    We investigated whether PET radiomic features are affected by differences in the scanner, scan protocol, and lesion location using 18 F-FDG PET/CT and PET/MR scans. SUV, TMR, skewness, kurtosis, entropy, and homogeneity strongly correlated between PET/CT and PET/MR images. SUVs were significantly higher on PET/MR 0-2 min and PET/MR 0-10 min than on PET/CT in gynecological cancer ( p = 0.008 and 0.008, respectively), whereas no significant difference was observed between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images in oral cavity/oropharyngeal cancer. TMRs on PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min increased in this order in gynecological cancer and oral cavity/oropharyngeal cancer. In contrast to conventional and histogram indices, 4 textural features (entropy, homogeneity, SRE, and LRE) were not significantly different between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images. 18 F-FDG PET radiomic features strongly correlated between PET/CT and PET/MR images. Dixon-based attenuation correction on PET/MR images underestimated tumor tracer uptake more significantly in oral cavity/oropharyngeal cancer than in gynecological cancer. 18 F-FDG PET textural features were affected less by differences in the scanner and scan protocol than conventional and histogram features, possibly due to the resampling process using a medium bin width. Eight patients with gynecological cancer and 7 with oral cavity/oropharyngeal cancer underwent a whole-body 18 F-FDG PET/CT scan and regional PET/MR scan in one day. PET/MR scans were performed for 10 minutes in the list mode, and PET/CT and 0-2 min and 0-10 min PET/MR images were reconstructed. The standardized uptake value (SUV), tumor-to-muscle SUV ratio (TMR), skewness, kurtosis, entropy, homogeneity, short-run emphasis (SRE), and long-run emphasis (LRE) were compared between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images.

  10. Synthesis of a new benzanthrone probe for pH determination based on PET and ICT

    International Nuclear Information System (INIS)

    Miladinova, Polya M.

    2016-01-01

    The synthesis and sensor activity of a novel benzanthrone fluoropore is reported. The system is configured on the “fluoropore–receptor_1–spacer–receptor_2” model able to act as a pH-probe via PET and ICT fluorescence sensing mechanism. The novel probe shows “off-on-off” switching properties under the transition from alkaline to acid media. Keywords: benzanthrone derivative, photoinduced electron transfer (PET), Internal Charge Transfer (ICT), selective pH sensor.

  11. Prognostic Value of FDG-PET, Based on the Revised Response Criteria, in Patients with Malignant Lymphoma: A Comparison with CT/MRI Evaluations, Based on the International Working Group/Cotswolds Meeting Criteria

    International Nuclear Information System (INIS)

    Isohashi, Kayako; Tatsumi, Mitsuaki; Kato, Hiroki; Fukushima, Kentaro; Maeda, Tetsuo; Watabe, Tadashi; Shimosegawa, Eku; Kanakura, Yuzuru; Hatazawa, Jun

    2015-01-01

    Post-treatment evaluations by CT/MRI (based on the International Working Group/Cotswolds meeting guidelines) and PET (based on Revised Response Criteria), were examined in terms of progression-free survival (PFS) in patients with malignant lymphoma (ML). 79 patients, undergoing CT/MRI for the examination of suspected lesions and whole-body PET/CT before and after therapy, were included in the study during April 2007-January 2013. The relationship between post-treatment evaluations (CT/MRI and PET) and PFS during the follow-up period was examined, using Kaplan-Meier survival analysis. The patients were grouped according to the histological type into Hodgkin’s lymphoma (HL), diffuse large B-cell lymphoma (DLBCL), and other histological types. The association between post-treatment evaluations (PET or PET combined with CT/MRI) and PFS was examined separately. Moreover, the relationship between disease recurrence and serum soluble interleukin-2 receptor, lactic dehydrogenase, and C-reactive protein levels was evaluated before and after the treatment. Patients with incomplete remission on both CT/MRI and PET had a significantly shorter PFS, compared to patients with complete remission on both CT/MRI and PET and those exhibiting incomplete remission on CT/MRI and complete remission on PET (P<0.001). Post-treatment PET evaluations were strongly correlated with patient outcomes in cases with HL or DLBCL (P<0.01) and other histological types (P<0.001). In patients with HL or DLBCL, incomplete remission on both CT/MRI and PET was associated with a significantly shorter PFS, compared to patients with complete remission on both CT/MRI and PET (P<0.05) and those showing incomplete remission on CT/MRI and complete remission on PET (P<0.01). In patients with other histological types, incomplete remission on both CT/MRI and PET was associated with a significantly shorter PFS, compared to cases with complete remission on both CT/MRI and PET (P<0.001). None of the serum parameters

  12. A fast preamplifier concept for SiPM-based time-of-flight PET detectors

    Energy Technology Data Exchange (ETDEWEB)

    Huizenga, J., E-mail: j.huizenga@tudelft.nl [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Seifert, S. [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Schreuder, F. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Dam, H.T. van [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Dendooven, P.; Loehner, H.; Vinke, R. [Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); Schaart, D.R. [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands)

    2012-12-11

    Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise ratio are crucial. Challenges include the high sensor capacitance, typically >300 pF for a 3 mm Multiplication-Sign 3 mm SiPM sensor, as well as oscillation issues. Here we present a preamplifier concept based on low noise, high speed transistors, designed for optimum timing performance. The input stage consists of a transimpedance common-base amplifier with a very low input impedance even at high frequencies, which assures a good linearity and avoids that the high detector capacitance affects the amplifier bandwidth. The amplifier has a fast timing output as well as a 'slow' energy output optimized for determining the total charge content of the pulse. The rise time of the amplifier is about 300 ps. The measured coincidence resolving time (CRT) for 511 keV photon pairs using the amplifiers in combination with 3 mm Multiplication-Sign 3 mm SiPMs (Hamamatsu MPPC-S10362-33-050C) coupled to 3 mm Multiplication-Sign 3 mm Multiplication-Sign 5 mm LaBr{sub 3}:Ce and LYSO:Ce crystals equals 95 ps FWHM and 138 ps FWHM, respectively.

  13. A fast preamplifier concept for SiPM-based time-of-flight PET detectors

    International Nuclear Information System (INIS)

    Huizenga, J.; Seifert, S.; Schreuder, F.; Dam, H.T. van; Dendooven, P.; Löhner, H.; Vinke, R.; Schaart, D.R.

    2012-01-01

    Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise ratio are crucial. Challenges include the high sensor capacitance, typically >300 pF for a 3 mm×3 mm SiPM sensor, as well as oscillation issues. Here we present a preamplifier concept based on low noise, high speed transistors, designed for optimum timing performance. The input stage consists of a transimpedance common-base amplifier with a very low input impedance even at high frequencies, which assures a good linearity and avoids that the high detector capacitance affects the amplifier bandwidth. The amplifier has a fast timing output as well as a ‘slow’ energy output optimized for determining the total charge content of the pulse. The rise time of the amplifier is about 300 ps. The measured coincidence resolving time (CRT) for 511 keV photon pairs using the amplifiers in combination with 3 mm×3 mm SiPMs (Hamamatsu MPPC-S10362-33-050C) coupled to 3 mm×3 mm×5 mm LaBr 3 :Ce and LYSO:Ce crystals equals 95 ps FWHM and 138 ps FWHM, respectively.

  14. PET and PET-CT. State of the art and future prospects

    International Nuclear Information System (INIS)

    Fanti, Stefano; Franchi, Roberto; Battista, Giuseppe; Monetti, Nino; Canini, Romeo

    2005-01-01

    Fluoro-deoxyglucose positron emission tomography (FDG PET) enables the in vivo study of tissue metabolism, and thus is able to identify malignant tumours as hypermetabolic lesions by an increase in tracer uptake. Many papers have demonstrated both the relevant impact of FDG PET on staging of many cancers and the superior accuracy of the technique compared with conventional diagnostic methods for pre-treatment evaluation, therapy response evaluation and relapse identification. In particular PET was found useful in identifying lymph nodal and metastatic spread. thus altering patient management in more than 30% of cases. PET images, however, provide limited anatomical data, which in regions such as the head and neck, mediastinum and pelvic cavity is a significant drawback. The exact localization of lesions may also be difficult in some cases, on the basis of PET images alone. The introduction of combined PET-computed tomography (PET-CT) scanners enables the almost simultaneous acquisition of transmission and emission images, thus obtaining optimal fusion images in a very short time. PET-CT fusion images enable lesions to be located, reducing false positive studies and increasing accuracy; the overall duration of examination may also be reduced. On the basis of both literature data and our experience we established the clinical indications when PET-CT may be particularly useful, in comparison with PET alone. It should also be underlined that the use of PET-CT is almost mandatory for new traces such as C-choline and C-methionine; these new tracers may be applied for studying tumours not assessable with FDG, such as prostate cancer. In conclusion PET-CT is at present the most advanced method for metabolic imaging, and is capable of precisely localizing and assessing tumours; fusion images reduce false positive and inconclusive studies, thus increasing diagnostic accuracy [it

  15. New developments in PET detector technology

    International Nuclear Information System (INIS)

    Niu Lingxin; Zhao Shujun; Zhang Bin; Liu Haojia

    2010-01-01

    The researches on PET detector are always active and innovative area. The research direction of PET detector includes improving performances of scintillator-based detectors, investigating new detectors suitable for multi-modality imaging (e.g. PET/CT and PET/MRI), meeting requirements of TOF and DOI technologies and boosting the development of the technologies. In this paper, new developments in PET detector technology about scintillation crystal, photodetector and semiconductor detector is introduced. (authors)

  16. Evaluation of data reduction methods for dynamic PET series based on Monte Carlo techniques and the NCAT phantom

    International Nuclear Information System (INIS)

    Thireou, Trias; Rubio Guivernau, Jose Luis; Atlamazoglou, Vassilis; Ledesma, Maria Jesus; Pavlopoulos, Sotiris; Santos, Andres; Kontaxakis, George

    2006-01-01

    A realistic dynamic positron-emission tomography (PET) thoracic study was generated, using the 4D NURBS-based (non-uniform rational B-splines) cardiac-torso (NCAT) phantom and a sophisticated model of the PET imaging process, simulating two solitary pulmonary nodules. Three data reduction and blind source separation methods were applied to the simulated data: principal component analysis, independent component analysis and similarity mapping. All methods reduced the initial amount of image data to a smaller, comprehensive and easily managed set of parametric images, where structures were separated based on their different kinetic characteristics and the lesions were readily identified. The results indicate that the above-mentioned methods can provide an accurate tool for the support of both visual inspection and subsequent detailed kinetic analysis of the dynamic series via compartmental or non-compartmental models

  17. Prediction of chemotherapy outcome in patients with metastatic soft tissue sarcomas based on dynamic FDG PET (dPET) and a multiparameter analysis

    International Nuclear Information System (INIS)

    Dimitrakopoulou-Strauss, Antonia; Strauss, Ludwig G.; Vasamiliette, Julie; Egerer, Gerlinde; Schmitt, Thomas; Kasper, Bernd; Haberkorn, Uwe

    2010-01-01

    Dynamic PET studies with 18 F-FDG were performed in patients with metastatic soft tissue sarcomas who received conventional chemotherapy with doxorubicin hydrochloride (Adriamycin) and ifosfamide (AI-G). The goal of the study was to evaluate the impact of full kinetic analysis and assess its value with regard to the therapy outcome based on survival data. The evaluation included 17 patients with 29 metastatic lesions of soft tissue sarcomas, who were treated with chemotherapy consisting of an AI-G regimen prior to high-dose chemotherapy and peripheral blood stem cell transplantation where applicable. Patients were examined prior to onset of therapy and after completion of the first cycle of AI-G. Restaging data (n = 17) based on Response Evaluation Criteria in Solid Tumors were available. Survival data (n = 14) served for reference. The following parameters were retrieved from the dynamic PET studies: standardized uptake value (SUV), fractal dimension, two-compartment model with computation of k1, k2, k3, k4 (unit: 1/min), the fractional blood volume and the FDG influx calculated according to Patlak. The mean SUV was 6.9 prior to therapy and 4.7 after one cycle. The mean influx was 0.066 prior to therapy in comparison to 0.058 after one cycle. We dichotomized the patients according to the median survival time of 320 days into response (n = 6) and non-response (n = 8). The mean SUV was 7.6 in the group of responders and 5.4 in the group of non-responders prior to therapy. Responders revealed a mean SUV of 3.8 after therapy as compared to 5.0 SUV for non-responders. We used discriminant analysis to classify the patients into the two response groups. The classification of the non-responders was generally higher (negative predictive value > 61%) than for the responders. Finally, the combined use of the four predictor variables, namely mean SUV and k1 of both studies led to the highest accuracy of 90% for both groups. The data demonstrate that only a multiparameter

  18. Synthesis and Biological Evaluation of Thiophene-Based Cannabinoid Receptor Type 2 Radiotracers for PET Imaging

    Directory of Open Access Journals (Sweden)

    Ahmed Haider

    2016-07-01

    Full Text Available Over the past two decades, our understanding of the endocannabinoid system has greatly improved due to the wealth of results obtained from exploratory studies. Currently, two cannabinoid receptor subtypes have been well characterized. The cannabinoid receptor type 1 (CB1 is widely expressed in the central nervous system, while the levels of the cannabinoid receptor type 2 (CB2 in the brain and spinal cord of healthy individuals are relatively low. However, recent studies demonstrated a CB2 upregulation on activated microglia upon neuroinflammation, an indicator of neurodegeneration. Our research group aims to develop a suitable positron emission tomography (PET tracer to visualize the CB2 receptor in patients suffering from neurodegenerative diseases. Herein we report two novel thiophene-based 11C-labeled PET ligands designated [11C]AAT-015 and [11C]AAT-778. The reference compounds were synthesized using Gewald reaction conditions to obtain the aminothiophene intermediates, followed by amide formation. Saponification of the esters provided their corresponding precursors. Binding affinity studies revealed Ki values of 3.3 ± 0.5 nM (CB2 and 1.0 ± 0.2 µM (CB1 for AAT-015. AAT-778 showed similar Ki values of 4.3 ± 0.7 nM (CB2 and 1.1 ± 0.1 µM (CB1. Radiosynthesis was carried out under basic conditions using [11C]iodomethane as methylating agent. After semi-preparative HPLC purification both radiolabeled compounds were obtained in 99% radiochemical purity and the radiochemical yields ranged from 12 to 37%. Specific activity was between 96 - 449 GBq/µmol for both tracers. In order to demonstrate CB2 specificity of [11C]AAT-015 and [11C]AAT-778, we carried out autoradiography studies using CB2-positive mouse/rat spleen tissues. The obtained results revealed unspecific binding in spleen tissue that was not blocked by an excess of CB2-specific ligand GW402833. For in vivo analysis, [11C]AAT-015 was administered to healthy rats via tail

  19. Pet exposure in utero and postnatal decreases the effects of air pollutants on hypertension in children: A large population based cohort study.

    Science.gov (United States)

    Lawrence, Wayne R; Yang, Mo; Lin, Shao; Wang, Si-Quan; Liu, Yimin; Ma, Huimin; Chen, Duo-Hong; Yang, Bo-Yi; Zeng, Xiao-Wen; Hu, Li-Wen; Dong, Guang-Hui

    2018-07-01

    The effect of ambient air pollution exposure on childhood hypertension has emerged as a concern in China, and previous studies suggested pet ownership is associated with lower blood pressure (BP). However, limited information exists on the interactive effects pet ownership and air pollution exposure has on hypertension. We investigated the interactions between exposure to pet ownership and air pollutants on hypertension in Chinese children. 9354 students in twenty-four elementary and middle schools (aged 5-17 years) in Northeastern China were evaluated during 2012-2013. Four-year average concentrations of particulate matter with aerodynamic diameter of ≤10 μm (PM 10 ), SO 2 , NO 2 , and O 3 , were collected in the 24 districts from 2009 to 2012. Hypertension was defined as average diastolic or systolic BP (three time measurements) in the 95th percentile or higher based on height, age, and sex. To examine effects, two-level regression analysis was used, controlling covariates. Consistent interactions between exposure to pet and air pollutants were observed. Compared to children exposed to pet, those not exposed exhibited consistently stronger effects of air pollution. The highest odds ratios (ORs) per 30.6 μg/m 3 increase in PM 10 were 1.79 (95%confidence interval [95%CI]: 1.29-2.50) in children without current pet exposure compared to 1.24 (95%CI: 0.85-1.82) in children with current pet exposure. As for BP, only O 3 had an interaction for all exposure to pet ownership types, and showed lower BP in children exposed to pet. The increases in mean diastolic BP per 46.3 μg/m 3 increase in O 3 were 0.60  mmHg (95%CI: 0.21, 0.48) in children without pet exposure in utero compared with 0.34  mmHg (95%CI: 0.21, 0.48) in their counterparts. When stratified by age, pet exposure was more protective among younger children. In conclusion, in this large population-based cohort, pet ownership is associated with smaller associations between air pollution and

  20. A Novel Time-Based Readout Scheme for a Combined PET-CT Detector Using APDs

    CERN Document Server

    Powolny, F; Hillemanns, H; Jarron, P; Lecoq, P; Meyer, T C; Moraes, D

    2008-01-01

    This paper summarizes CERN R&D work done in the framework of the European Commission's FP6 BioCare Project. The objective was to develop a novel "time-based" signal processing technique to read out LSO-APD photodetectors for medical imaging. An important aspect was to employ the technique in a combined scenario for both computer tomography (CT) and positron emission tomography (PET) with effectively no tradeoffs in efficiency and resolution compared to traditional single mode machines. This made the use of low noise and yet very high-speed monolithic front-end electronics essential so as to assure the required timing characteristics together with a high signal-to-noise ratio. Using APDs for photon detection, two chips, traditionally employed for particle physics, could be identified to meet the above criteria. Although both were not optimized for their intended new medical application, excellent performance in conjunction with LSO-APD sensors could be derived. Whereas a measured energy resolution of 16% (...

  1. Test of a single module of the J-PET scanner based on plastic scintillators

    International Nuclear Information System (INIS)

    Moskal, P.; Niedźwiecki, Sz.; Bednarski, T.; Czerwiński, E.; Kapłon, Ł.; Kubicz, E.; Moskal, I.; Pawlik-Niedźwiecka, M.; Sharma, N.G.; Silarski, M.; Zieliński, M.; Zoń, N.; Białas, P.; Gajos, A.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kowalski, P.; Kozik, T.; Krzemień, W.

    2014-01-01

    A Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this paper we report on tests of a single detection module built out from the BC-420 plastic scintillator strip (with dimensions of 5×19×300 mm 3 ) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68 Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50 ps intervals. The time resolution of the prototype module was established to be better than 80 ps (σ) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93 cm (σ) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to σ(E)/E≈0.044/√(E(MeV)) and corresponds to the σ(E)/E of 7.5% at the Compton edge

  2. Test of a single module of the J-PET scanner based on plastic scintillators

    Science.gov (United States)

    Moskal, P.; Niedźwiecki, Sz.; Bednarski, T.; Czerwiński, E.; Kapłon, Ł.; Kubicz, E.; Moskal, I.; Pawlik-Niedźwiecka, M.; Sharma, N. G.; Silarski, M.; Zieliński, M.; Zoń, N.; Białas, P.; Gajos, A.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kowalski, P.; Kozik, T.; Krzemień, W.; Molenda, M.; Pałka, M.; Raczyński, L.; Rudy, Z.; Salabura, P.; Słomski, A.; Smyrski, J.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.

    2014-11-01

    A Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this paper we report on tests of a single detection module built out from the BC-420 plastic scintillator strip (with dimensions of 5×19×300 mm3) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50 ps intervals. The time resolution of the prototype module was established to be better than 80 ps (σ) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93 cm (σ) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to σ(E) / E ≈ 0.044 /√{ E(MeV) } and corresponds to the σ(E) / E of 7.5% at the Compton edge.

  3. Fast gradient-based methods for Bayesian reconstruction of transmission and emission PET images

    International Nuclear Information System (INIS)

    Mumcuglu, E.U.; Leahy, R.; Zhou, Z.; Cherry, S.R.

    1994-01-01

    The authors describe conjugate gradient algorithms for reconstruction of transmission and emission PET images. The reconstructions are based on a Bayesian formulation, where the data are modeled as a collection of independent Poisson random variables and the image is modeled using a Markov random field. A conjugate gradient algorithm is used to compute a maximum a posteriori (MAP) estimate of the image by maximizing over the posterior density. To ensure nonnegativity of the solution, a penalty function is used to convert the problem to one of unconstrained optimization. Preconditioners are used to enhance convergence rates. These methods generally achieve effective convergence in 15--25 iterations. Reconstructions are presented of an 18 FDG whole body scan from data collected using a Siemens/CTI ECAT931 whole body system. These results indicate significant improvements in emission image quality using the Bayesian approach, in comparison to filtered backprojection, particularly when reprojections of the MAP transmission image are used in place of the standard attenuation correction factors

  4. The findings of F-18 FDG camera-based coincidence PET in acute leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, S. N.; Joh, C. W.; Lee, M. H. [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2002-07-01

    We evaluated the usefulness of F-18 FDG coincidence PET (CoDe-PET) using a dual-head gamma camera in the assessment of patients with acute leukemia. F-18 FDG CoDE-PET studies were performed in 5 patients with acute leukemia (6 ALL and 2 AML) before or after treatment. CoDe-PET was performed utilizing a dual-head gamma camera equipped with 5/8 inch NaI(Tl) crystal. Image acquisition began 60 minutes after the injection of F-18 FDG in the fasting state. A whole trunk from cervical to inguinal regions or selected region were scanned. No attenuation correction was made and image reconstruction was done using filtered back-projection. CoDe-PET studies were evaluated visually. F-18 FDG image performed in 5 patients with ALL before therapy depicted multiple lymph node involvement and diffuse increased uptake involving axial skeleton, pelvis and femurs. F-18 FDG image done in 2 AML after chemotherapy showed only diffuse increased uptake in sternum, ribs, spine, pelvis and proximal femur and these may be due to G-CSF stimulation effect in view of drug history. But bone marrow histology showed scattered blast cell suggesting incomplete remission in one and completer remission in another. F-18 image done in 1 ALL after therapy showed no abnormal uptake. CoDe-PET with F-18 FDG in acute lymphoblastic lymphoma showed multiple lymphnode and bone marrow involvement in whole body. Therefore we conclude that CoDe-PET with F-18 FDG usefulness for evaluation of extent in acute lymphoblastic leukemia. But there was a limitation to assess therapy effectiveness during therapy due to reactive bone marrow.

  5. Dynamic PET reconstruction using temporal patch-based low rank penalty for ROI-based brain kinetic analysis

    International Nuclear Information System (INIS)

    Kim, Kyungsang; Ye, Jong Chul; Son, Young Don; Cho, Zang Hee; Bresler, Yoram; Ra, Jong Beom

    2015-01-01

    Dynamic positron emission tomography (PET) is widely used to measure changes in the bio-distribution of radiopharmaceuticals within particular organs of interest over time. However, to retain sufficient temporal resolution, the number of photon counts in each time frame must be limited. Therefore, conventional reconstruction algorithms such as the ordered subset expectation maximization (OSEM) produce noisy reconstruction images, thus degrading the quality of the extracted time activity curves (TACs). To address this issue, many advanced reconstruction algorithms have been developed using various spatio-temporal regularizations. In this paper, we extend earlier results and develop a novel temporal regularization, which exploits the self-similarity of patches that are collected in dynamic images. The main contribution of this paper is to demonstrate that the correlation of patches can be exploited using a low-rank constraint that is insensitive to global intensity variations. The resulting optimization framework is, however, non-Lipschitz and non-convex due to the Poisson log-likelihood and low-rank penalty terms. Direct application of the conventional Poisson image deconvolution by an augmented Lagrangian (PIDAL) algorithm is, however, problematic due to its large memory requirements, which prevents its parallelization. Thus, we propose a novel optimization framework using the concave-convex procedure (CCCP) by exploiting the Legendre–Fenchel transform, which is computationally efficient and parallelizable. In computer simulation and a real in vivo experiment using a high-resolution research tomograph (HRRT) scanner, we confirm that the proposed algorithm can improve image quality while also extracting more accurate region of interests (ROI) based kinetic parameters. Furthermore, we show that the total reconstruction time for HRRT PET is significantly accelerated using our GPU implementation, which makes the algorithm very practical in clinical environments

  6. PET imaging of HSV1-tk mutants with acquired specificity toward pyrimidine- and acycloguanosine-based radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Likar, Yury; Dobrenkov, Konstantin; Olszewska, Malgorzata; Shenker, Larissa; Hricak, Hedvig; Ponomarev, Vladimir [Memorial Sloan-Kettering Cancer Center, Molecular Imaging Laboratory, Department of Radiology, New York, NY (United States); Cai, Shangde [Memorial Sloan-Kettering Cancer Center, Radiochemistry/Cyclotron Core Facility, New York, NY (United States)

    2009-08-15

    The aim of this study was to create an alternative mutant of the herpes simplex virus type 1 thymidine kinase (HSV1-tk) reporter gene with reduced phosphorylation capacity for acycloguanosine derivatives, but not pyrimidine-based compounds that will allow for successful PET imaging. A new mutant of HSV1-tk reporter gene, suitable for PET imaging using pyrimidine-based radiotracers, was developed. The HSV1-tk mutant contains an arginine-to-glutamine substitution at position 176 (HSV1-R176Qtk) of the nucleoside binding region of the enzyme. The mutant-gene product showed favorable enzymatic characteristics toward pyrimidine-based nucleosides, while exhibiting reduced activity with acycloguanosine derivatives. In order to enhance HSV1-R176Qtk reporter activity with pyrimidine-based radiotracers, we introduced the R176Q substitution into the more active HSV1-sr39tk mutant. U87 human glioma cells transduced with the HSV1-R176Qsr39tk double mutant reporter gene showed high {sup 3}H-FEAU pyrimidine nucleoside and low {sup 3}H-penciclovir acycloguanosine analog uptake in vitro. PET imaging also demonstrated high {sup 18}F-FEAU and low {sup 18}F-FHBG accumulation in HSV1-R176Qsr39tk+ xenografts. The feasibility of imaging two independent nucleoside-specific HSV1-tk mutants in the same animal with PET was demonstrated. Two opposite xenografts expressing the HSV1-R176Qsr39tk reporter gene and the previously described acycloguanosine-specific mutant of HSV1-tk, HSV1-A167Ysr39tk reporter gene, were imaged using a short-lived pyrimidine-based {sup 18}F-FEAU and an acycloguanosine-based {sup 18}F-FHBG radiotracer, respectively, administered on 2 consecutive days. We conclude that in combination with acycloguanosine-specific HSV1-A167Ysr39tk reporter gene, a HSV1-tk mutant containing the R176Q substitution could be used for PET imaging of two different cell populations or concurrent molecular biological processes in the same living subject. (orig.)

  7. MR-based automatic delineation of volumes of interest in human brain PET images using probability maps

    DEFF Research Database (Denmark)

    Svarer, Claus; Madsen, Karina; Hasselbalch, Steen G.

    2005-01-01

    subjects' MR-images, where VOI sets have been defined manually. High-resolution structural MR-images and 5-HT(2A) receptor binding PET-images (in terms of (18)F-altanserin binding) from 10 healthy volunteers and 10 patients with mild cognitive impairment were included for the analysis. A template including...... 35 VOIs was manually delineated on the subjects' MR images. Through a warping algorithm template VOI sets defined from each individual were transferred to the other subjects MR-images and the voxel overlap was compared to the VOI set specifically drawn for that particular individual. Comparisons were...... delineation of the VOI set. The approach was also shown to work equally well in individuals with pronounced cerebral atrophy. Probability-map-based automatic delineation of VOIs is a fast, objective, reproducible, and safe way to assess regional brain values from PET or SPECT scans. In addition, the method...

  8. The degradation potential of PET bottles in the marine environment: An ATR-FTIR based approach

    Science.gov (United States)

    Ioakeimidis, C.; Fotopoulou, K. N.; Karapanagioti, H. K.; Geraga, M.; Zeri, C.; Papathanassiou, E.; Galgani, F.; Papatheodorou, G.

    2016-03-01

    The dominance and persistence of plastic debris in the marine environment are well documented. No information exists in respect to their lifespan in the marine environment. Nevertheless, the degradation potential of plastic litter items remains a critical issue for marine litter research. In the present study, polyethylene terephthalate bottles (PETs) collected from the submarine environment were characterized using ATR-FTIR in respect to their degradation potential attributed to environmental conditions. A temporal indication was used as indicative to the years of presence of the PETs in the environment as debris. PETs seem to remain robust for approximately fifteen years. Afterwards, a significant decrease of the native functional groups was recorded; some even disappear; or new-not typical for PETs-are created. At a later stage, using the PET time series collected from the Saronikos Gulf (Aegean Sea-E. Mediterranean), it was possible to date bottles that were collected from the bottom of the Ionian Sea (W. Greece). It is the first time that such a study has been conducted with samples that were actually degraded in the marine environment.

  9. A novel APD-based detector module for multi-modality PET/SPECT/CT scanners

    International Nuclear Information System (INIS)

    Saoudi, A.; Lecomte, R.

    1999-01-01

    The lack of anatomical information in SPECT and PET images is one of the major factors limiting the ability to localize and accurately quantify radionuclide uptake in small regions of interest. This problem could be resolved by using multi-modality scanners having the capability to acquire anatomical and functional images simultaneously. The feasibility of a novel detector suitable for measuring high-energy annihilation radiation in PET, medium-energy γ-rays in SPECT and low-energy X-rays in transmission CT is demonstrated and its performance is evaluated for potential use in multi-modality PET/SPECT/CT imaging. The proposed detector consists of a thin CsI(Tl) scintillator sitting on top of a deep GSO/LSO pair read out by an avalanche photodiode. The GSO/LOS pair provides depth-of-interaction information for 511 keV detection in PET, while the thin CsI(Tl) that is essentially transparent to annihilation radiation is used for detecting lower energy X- and γ-rays. The detector performance is compared to that of an LSO/YSO phoswich. Although the implementation of the proposed GSO/LSO/CsI(Tl) detector raises special problems that increase complexity, it generally outperforms the LSO/YSO phoswich for simultaneous PET, SPECT and CT imaging

  10. Image quality assessment of LaBr3-based whole-body 3D PET scanners: a Monte Carlo evaluation

    International Nuclear Information System (INIS)

    Surti, S; Karp, J S; Muehllehner, G

    2004-01-01

    The main thrust for this work is the investigation and design of a whole-body PET scanner based on new lanthanum bromide scintillators. We use Monte Carlo simulations to generate data for a 3D PET scanner based on LaBr 3 detectors, and to assess the count-rate capability and the reconstructed image quality of phantoms with hot and cold spheres using contrast and noise parameters. Previously we have shown that LaBr 3 has very high light output, excellent energy resolution and fast timing properties which can lead to the design of a time-of-flight (TOF) whole-body PET camera. The data presented here illustrate the performance of LaBr 3 without the additional benefit of TOF information, although our intention is to develop a scanner with TOF measurement capability. The only drawbacks of LaBr 3 are the lower stopping power and photo-fraction which affect both sensitivity and spatial resolution. However, in 3D PET imaging where energy resolution is very important for reducing scattered coincidences in the reconstructed image, the image quality attained in a non-TOF LaBr 3 scanner can potentially equal or surpass that achieved with other high sensitivity scanners. Our results show that there is a gain in NEC arising from the reduced scatter and random fractions in a LaBr 3 scanner. The reconstructed image resolution is slightly worse than a high-Z scintillator, but at increased count-rates, reduced pulse pileup leads to an image resolution similar to that of LSO. Image quality simulations predict reduced contrast for small hot spheres compared to an LSO scanner, but improved noise characteristics at similar clinical activity levels

  11. Choline or methionine reverses impaired secretion of VLDL by hepatocytes from choline-deficient rats

    International Nuclear Information System (INIS)

    Yao, Z.; Vance, D.E.

    1987-01-01

    Male rats fed a choline-deficient (CD) diet for three days accumulated triacylglycerol (TG) in the liver. Hepatocytes from these rats were cultured and maintained in a medium + choline. The rate of secretion of TG was reduced by 50% in the CD cells. Correspondingly, [ 3 H]oleate and [ 3 H]glycerol were incorporated at a 2-fold higher rate into TG secreted by choline-supplemented cells compared to CD cells. Isolation of lipoprotein fractions by ultracentrifugation showed that the reduced secretion of TG by CD hepatocytes was mainly due to an impaired secretion of very low density lipoprotein (VLDL). Incorporation of [ 3 H]leucine into secreted apoB/sub H/, apoB/sub L/ and apoE was markedly reduced in CD cells compared to choline-supplemented cells. Secretion of high density lipoprotein was not reduced in the CD hepatocytes. Normal secretion of VLDL was resumed upon addition of methionine to the CD cells

  12. New method for extracting tumors in PET/CT images based on the probability distribution

    International Nuclear Information System (INIS)

    Nitta, Shuhei; Hontani, Hidekata; Hukami, Tadanori

    2006-01-01

    In this report, we propose a method for extracting tumors from PET/CT images by referring to the probability distribution of pixel values in the PET image. In the proposed method, first, the organs that normally take up fluorodeoxyglucose (FDG) (e.g., the liver, kidneys, and brain) are extracted. Then, the tumors are extracted from the images. The distribution of pixel values in PET images differs in each region of the body. Therefore, the threshold for detecting tumors is adaptively determined by referring to the distribution. We applied the proposed method to 37 cases and evaluated its performance. This report also presents the results of experiments comparing the proposed method and another method in which the pixel values are normalized for extracting tumors. (author)

  13. Blind source separation analysis of PET dynamic data: a simple method with exciting MR-PET applications

    Energy Technology Data Exchange (ETDEWEB)

    Oros-Peusquens, Ana-Maria; Silva, Nuno da [Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Weiss, Carolin [Department of Neurosurgery, University Hospital Cologne, 50924 Cologne (Germany); Stoffels, Gabrielle; Herzog, Hans; Langen, Karl J [Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Shah, N Jon [Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Jülich-Aachen Research Alliance (JARA) - Section JARA-Brain RWTH Aachen University, 52074 Aachen (Germany)

    2014-07-29

    Denoising of dynamic PET data improves parameter imaging by PET and is gaining momentum. This contribution describes an analysis of dynamic PET data by blind source separation methods and comparison of the results with MR-based brain properties.

  14. Choline and Choline Metabolite Patterns and Associations in Blood and Milk during Lactation in Dairy Cows

    Science.gov (United States)

    Artegoitia, Virginia M.; Middleton, Jesse L.; Harte, Federico M.; Campagna, Shawn R.; de Veth, Michael J.

    2014-01-01

    Milk and dairy products are an important source of choline, a nutrient essential for human health. Infant formula derived from bovine milk contains a number of metabolic forms of choline, all contribute to the growth and development of the newborn. At present, little is known about the factors that influence the concentrations of choline metabolites in milk. The objectives of this study were to characterize and then evaluate associations for choline and its metabolites in blood and milk through the first 37 weeks of lactation in the dairy cow. Milk and blood samples from twelve Holstein cows were collected in early, mid and late lactation and analyzed for acetylcholine, free choline, betaine, glycerophosphocholine, lysophosphatidylcholine, phosphatidylcholine, phosphocholine and sphingomyelin using hydrophilic interaction liquid chromatography-tandem mass spectrometry, and quantified using stable isotope-labeled internal standards. Total choline concentration in plasma, which was almost entirely phosphatidylcholine, increased 10-times from early to late lactation (1305 to 13,535 µmol/L). In milk, phosphocholine was the main metabolite in early lactation (492 µmol/L), which is a similar concentration to that found in human milk, however, phosphocholine concentration decreased exponentially through lactation to 43 µmol/L in late lactation. In contrast, phosphatidylcholine was the main metabolite in mid and late lactation (188 µmol/L and 659 µmol/L, respectively), with the increase through lactation positively correlated with phosphatidylcholine in plasma (R 2 = 0.78). Unlike previously reported with human milk we found no correlation between plasma free choline concentration and milk choline metabolites. The changes in pattern of phosphocholine and phosphatidylcholine in milk through lactation observed in the bovine suggests that it is possible to manufacture infant formula that more closely matches these metabolites profile in human milk. PMID:25157578

  15. Choline and choline metabolite patterns and associations in blood and milk during lactation in dairy cows.

    Directory of Open Access Journals (Sweden)

    Virginia M Artegoitia

    Full Text Available Milk and dairy products are an important source of choline, a nutrient essential for human health. Infant formula derived from bovine milk contains a number of metabolic forms of choline, all contribute to the growth and development of the newborn. At present, little is known about the factors that influence the concentrations of choline metabolites in milk. The objectives of this study were to characterize and then evaluate associations for choline and its metabolites in blood and milk through the first 37 weeks of lactation in the dairy cow. Milk and blood samples from twelve Holstein cows were collected in early, mid and late lactation and analyzed for acetylcholine, free choline, betaine, glycerophosphocholine, lysophosphatidylcholine, phosphatidylcholine, phosphocholine and sphingomyelin using hydrophilic interaction liquid chromatography-tandem mass spectrometry, and quantified using stable isotope-labeled internal standards. Total choline concentration in plasma, which was almost entirely phosphatidylcholine, increased 10-times from early to late lactation (1305 to 13,535 µmol/L. In milk, phosphocholine was the main metabolite in early lactation (492 µmol/L, which is a similar concentration to that found in human milk, however, phosphocholine concentration decreased exponentially through lactation to 43 µmol/L in late lactation. In contrast, phosphatidylcholine was the main metabolite in mid and late lactation (188 µmol/L and 659 µmol/L, respectively, with the increase through lactation positively correlated with phosphatidylcholine in plasma (R2 = 0.78. Unlike previously reported with human milk we found no correlation between plasma free choline concentration and milk choline metabolites. The changes in pattern of phosphocholine and phosphatidylcholine in milk through lactation observed in the bovine suggests that it is possible to manufacture infant formula that more closely matches these metabolites profile in human milk.

  16. What Is the Best Way to Contour Lung Tumors on PET Scans? Multiobserver Validation of a Gradient-Based Method Using a NSCLC Digital PET Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Werner-Wasik, Maria, E-mail: Maria.Werner-wasik@jeffersonhospital.org [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Nelson, Arden D. [MIM Software Inc., Cleveland, OH (United States); Choi, Walter [Department of Radiation Oncology, UPMC Health Systems, Pittsburgh, PA (United States); Arai, Yoshio [Department of Radiation Oncology, Beth Israel Medical Center, New York, NY (Israel); Faulhaber, Peter F. [University Hospitals Case Medical Center, Cleveland, OH (United States); Kang, Patrick [Department of Radiology, Beth Israel Medical Center, New York, NY (Israel); Almeida, Fabio D. [Division of Nuclear Medicine, University of Arizona Health Sciences Center, Tucson, AZ (United States); Xiao, Ying; Ohri, Nitin [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Brockway, Kristin D.; Piper, Jonathan W.; Nelson, Aaron S. [MIM Software Inc., Cleveland, OH (United States)

    2012-03-01

    Purpose: To evaluate the accuracy and consistency of a gradient-based positron emission tomography (PET) segmentation method, GRADIENT, compared with manual (MANUAL) and constant threshold (THRESHOLD) methods. Methods and Materials: Contouring accuracy was evaluated with sphere phantoms and clinically realistic Monte Carlo PET phantoms of the thorax. The sphere phantoms were 10-37 mm in diameter and were acquired at five institutions emulating clinical conditions. One institution also acquired a sphere phantom with multiple source-to-background ratios of 2:1, 5:1, 10:1, 20:1, and 70:1. One observer segmented (contoured) each sphere with GRADIENT and THRESHOLD from 25% to 50% at 5% increments. Subsequently, seven physicians segmented 31 lesions (7-264 mL) from 25 digital thorax phantoms using GRADIENT, THRESHOLD, and MANUAL. Results: For spheres <20 mm in diameter, GRADIENT was the most accurate with a mean absolute % error in diameter of 8.15% (10.2% SD) compared with 49.2% (51.1% SD) for 45% THRESHOLD (p < 0.005). For larger spheres, the methods were statistically equivalent. For varying source-to-background ratios, GRADIENT was the most accurate for spheres >20 mm (p < 0.065) and <20 mm (p < 0.015). For digital thorax phantoms, GRADIENT was the most accurate (p < 0.01), with a mean absolute % error in volume of 10.99% (11.9% SD), followed by 25% THRESHOLD at 17.5% (29.4% SD), and MANUAL at 19.5% (17.2% SD). GRADIENT had the least systematic bias, with a mean % error in volume of -0.05% (16.2% SD) compared with 25% THRESHOLD at -2.1% (34.2% SD) and MANUAL at -16.3% (20.2% SD; p value <0.01). Interobserver variability was reduced using GRADIENT compared with both 25% THRESHOLD and MANUAL (p value <0.01, Levene's test). Conclusion: GRADIENT was the most accurate and consistent technique for target volume contouring. GRADIENT was also the most robust for varying imaging conditions. GRADIENT has the potential to play an important role for tumor delineation in

  17. Effect of choline chloride supplementation on milk production and milk composition of Etawah grade goats

    Directory of Open Access Journals (Sweden)

    Supriyati

    2016-08-01

    Full Text Available Abstract Background The effect of choline chloride supplementation through forced drinking combined with concentrate diets containing Ca-fish oil on milk production and milk composition of Etawah Grade goats was evaluated. Choline chloride is an essential component in ruminant diets as it is required for fat metabolism. Method The experiment was conducted in a completely randomized block design with three types of treatments and eight replications. The trial had two successive experimental periods; the first, during the eight weeks of late pregnancy, and the second, during the first 12 weeks of lactation. Twenty-four Etawah Grade does in the second gestation period were divided into three treatment groups. Commercial choline chloride 60 % in corncobs-based powder was used as a source of choline chloride. The treatments were no supplementation (control and supplemented with either 4 g or 8 g/2days of choline chloride. Choline chloride was given to the animals through a forced drinking technique, after dissolving it in 60 ml drinking water. The initial body weight of does was 38.81 ± 3.66 kg. The does were penned individually, and were given fresh chopped King Grass ad libitum and 700 g/day of concentrate diets containing Ca-fish oil, starting eight weeks prior to expecting kidding and continuing for 12 weeks of parturition. Results All nutrient intakes were not significantly different (p > 0.05 among the treatments during the late pregnancy and the lactation periods. Supplementation did not affect (p > 0.05 the average daily gains and feed conversion ratio during pregnancy but gave effects (p < 0.05 on the average daily gains, feed conversion ratio and income over feed cost during lactation. The highest average daily milk yields and 4 % fat corrected milk yields were found in goats supplemented with 4 g/2days of choline chloride and increased by 17.00 % and 24.67 %, respectively, compared to the control. Moreover, milk

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    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Lee, Jong Jin; Kang, Hye Jin; Lee, Hyo Jeong; Oh, Seung Ha; Kim, Chong Sun; Jung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National University College of Medicine