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Sample records for fdg small-animal pet

  1. Quantification of cerebral glucose metabolic rate in mice using 18F-FDG and small-animal PET.

    PubMed

    Yu, Amy S; Lin, Hong-Dun; Huang, Sung-Cheng; Phelps, Michael E; Wu, Hsiao-Ming

    2009-06-01

    The aim of this study was to evaluate various methods for estimating the metabolic rate of glucose utilization in the mouse brain (cMR(glc)) using small-animal PET and reliable blood curves derived by a microfluidic blood sampler. Typical values of (18)F-FDG rate constants of normal mouse cerebral cortex were estimated and used for cMR(glc) calculations. The feasibility of using the image-derived liver time-activity curve as a surrogate input function in various quantification methods was also evaluated. Thirteen normoglycemic C57BL/6 mice were studied. Eighteen blood samples were taken from the femoral artery by the microfluidic blood sampler. Tissue time-activity curves were derived from PET images. cMR(glc) values were calculated using 2 different input functions (one derived from the blood samples [IF(blood)] and the other from the liver time-activity curve [IF(liver)]) in various quantification methods, which included the 3-compartment (18)F-FDG model (from which the (18)F-FDG rate constants were derived), the Patlak analysis, and operational equations. The estimated cMR(glc) value based on IF(blood) and the 3-compartment model served as a standard for comparisons with the cMR(glc) values calculated by the other methods. The values of K(1), k(2), k(3), k(4), and K(FDG) estimated by IF(blood) and the 3-compartment model were 0.22 +/- 0.05 mL/min/g, 0.48 +/- 0.09 min(-1), 0.06 +/- 0.02 min(-1), 0.025 +/- 0.010 min(-1), and 0.024 +/- 0.007 mL/min/g, respectively. The standard cMR(glc) value was, therefore, 40.6 +/- 13.3 micromol/100 g/min (lumped constant = 0.6). No significant difference between the standard cMR(glc) and the cMR(glc) estimated by the operational equation that includes k(4) was observed. The standard cMR(glc) was also found to have strong correlations (r > 0.8) with the cMR(glc) value estimated by the use of IF(liver) in the 3-compartment model and with those estimated by the Patlak analysis (using either IF(blood) or IF(liver)). The (18)F-FDG

  2. Optimization of a Model Corrected Blood Input Function from Dynamic FDG-PET Images of Small Animal Heart In Vivo

    PubMed Central

    Zhong, Min; Kundu, Bijoy K.

    2013-01-01

    Quantitative evaluation of dynamic Positron Emission Tomography (PET) of mouse heart in vivo is challenging due to the small size of the heart and limited intrinsic spatial resolution of the PET scanner. Here, we optimized a compartment model which can simultaneously correct for spill over and partial volume effects for both blood pool and the myocardium, compute kinetic rate parameters and generate model corrected blood input function (MCBIF) from ordered subset expectation maximization – maximum a posteriori (OSEM-MAP) cardiac and respiratory gated 18F-FDG PET images of mouse heart with attenuation correction in vivo, without any invasive blood sampling. Arterial blood samples were collected from a single mouse to indicate the feasibility of the proposed method. In order to establish statistical significance, venous blood samples from n=6 mice were obtained at 2 late time points, when SP contamination from the tissue to the blood is maximum. We observed that correct bounds and initial guesses for the PV and SP coefficients accurately model the wash-in and wash-out dynamics of the tracer from mouse blood. The residual plot indicated an average difference of about 1.7% between the blood samples and MCBIF. The downstream rate of myocardial FDG influx constant, Ki (0.15±0.03 min−1), compared well with Ki obtained from arterial blood samples (P=0.716). In conclusion, the proposed methodology is not only quantitative but also reproducible. PMID:24741130

  3. Noninvasive image derived heart input function for CMRglc measurements in small animal slow infusion FDG PET studies

    NASA Astrophysics Data System (ADS)

    Xiong, Guoming; Cumming, Paul; Todica, Andrei; Hacker, Marcus; Bartenstein, Peter; Böning, Guido

    2012-12-01

    Absolute quantitation of the cerebral metabolic rate for glucose (CMRglc) can be obtained in positron emission tomography (PET) studies when serial measurements of the arterial [18F]-fluoro-deoxyglucose (FDG) input are available. Since this is not always practical in PET studies of rodents, there has been considerable interest in defining an image-derived input function (IDIF) by placing a volume of interest (VOI) within the left ventricle of the heart. However, spill-in arising from trapping of FDG in the myocardium often leads to progressive contamination of the IDIF, which propagates to underestimation of the magnitude of CMRglc. We therefore developed a novel, non-invasive method for correcting the IDIF without scaling to a blood sample. To this end, we first obtained serial arterial samples and dynamic FDG-PET data of the head and heart in a group of eight anaesthetized rats. We fitted a bi-exponential function to the serial measurements of the IDIF, and then used the linear graphical Gjedde-Patlak method to describe the accumulation in myocardium. We next estimated the magnitude of myocardial spill-in reaching the left ventricle VOI by assuming a Gaussian point-spread function, and corrected the measured IDIF for this estimated spill-in. Finally, we calculated parametric maps of CMRglc using the corrected IDIF, and for the sake of comparison, relative to serial blood sampling from the femoral artery. The uncorrected IDIF resulted in 20% underestimation of the magnitude of CMRglc relative to the gold standard arterial input method. However, there was no bias with the corrected IDIF, which was robust to the variable extent of myocardial tracer uptake, such that there was a very high correlation between individual CMRglc measurements using the corrected IDIF with gold-standard arterial input results. Based on simulation, we furthermore find that electrocardiogram-gating, i.e. ECG-gating is not necessary for IDIF quantitation using our approach.

  4. A Hybrid Clustering Method for ROI Delineation in Small Animal Dynamic PET Images: Application to the Automatic Estimation of FDG Input Functions

    PubMed Central

    Zheng, Xiujuan; Tian, Guangjian; Huang, Sung-Cheng; Feng, Dagan

    2011-01-01

    Tracer kinetic modeling with dynamic Positron Emission Tomography (PET) requires a plasma time-activity curve (PTAC) as an input function. Several image-derived input function (IDIF) methods that rely on drawing the region-of-interest (ROI) in large vascular structures have been proposed to overcome the problems caused by the invasive approach to obtaining the PTAC, especially for small animal studies. However, the manual placement of ROIs for estimating IDIF is subjective and labor-intensive, making it an undesirable and unreliable process. In this paper, we propose a novel hybrid clustering method (HCM) that objectively delineates ROIs in dynamic PET images for the estimation of IDIFs, and demonstrate its application to the mouse PET studies acquired with [18F]Fluoro-2-deoxy-2-D-glucose (FDG). We begin our HCM using K-means clustering for background removal. We then model the time-activity curves using polynomial regression mixture models in curve clustering for heart structure detection. The hierarchical clustering is finally applied for ROI refinements. The HCM achieved accurate ROI delineation in both computer simulations and experimental mouse studies. In the mouse studies the predicted IDIF had a high correlation with the gold standard, the PTAC derived from the invasive blood samples. The results indicate that the proposed HCM has a great potential in ROI delineation for automatic estimation of IDIF in dynamic FDG-PET studies. PMID:20952342

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

    PubMed Central

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

    2013-01-01

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

  6. A Very High Spatial Resolution Detector for Small Animal PET

    SciTech Connect

    Kanai Shah, M.S.

    2007-03-06

    Positron Emission Tomography (PET) is an in vivo analog of autoradiography and has the potential to become a powerful new tool in imaging biological processes in small laboratory animals. PET imaging of small animals can provide unique information that can help in advancement of human disease models as well as drug development. Clinical PET scanners used for human imaging are bulky, expensive and do not have adequate spatial resolution for small animal studies. Hence, dedicated, low cost instruments are required for conducting small animal studies with higher spatial resolution than what is currently achieved with clinical as well as dedicated small animal PET scanners. The goal of the proposed project is to investigate a new all solid-state detector design for small animal PET imaging. Exceptionally high spatial resolution, good timing resolution, and excellent energy resolution are expected from the proposed detector design. The Phase I project was aimed at demonstrating the feasibility of producing high performance solid-state detectors that provide high sensitivity, spatial resolution, and timing characteristics. Energy resolution characteristics of the new detector were also investigated. The goal of the Phase II project is to advance the promising solid-state detector technology for small animal PET and determine its full potential. Detectors modules will be built and characterized and finally, a bench-top small animal PET system will be assembled and evaluated.

  7. Comparison of the Intraperitoneal, Retroorbital and per Oral Routes for F-18 FDG Administration as Effective Alternatives to Intravenous Administration in Mouse Tumor Models Using Small Animal PET/CT Studies.

    PubMed

    Kim, Chulhan; Kim, In Hye; Kim, Seo-Il; Kim, Young Sang; Kang, Se Hun; Moon, Seung Hwan; Kim, Tae-Sung; Kim, Seok-Ki

    2011-09-01

    We compared alternative routes for (18)F-fluorodeoxyglucose (FDG) administration, such as the retroorbital (RO), intraperitoneal (IP) and per oral (PO) routes, with the intravenous (IV) route in normal tissues and tumors of mice. CRL-1642 (ATCC, Lewis lung carcinoma) cells were inoculated in female BALB/c-nu/nu mice 6 to 10 weeks old. When the tumor grew to about 9 mm in diameter, positron emission tomography (PET) scans were performed after FDG administration via the RO, IP, PO or IV route. Additional serial PET scans were performed using the RO, IV or IP route alternatively from 5 to 29 days after the tumor cell injection. There was no significant difference in the FDG uptake in normal tissues at 60 min after FDG administration via RO, IP and IV routes. PO administration, however, showed delayed distribution and unwanted high gastrointestinal uptake. Tumoral uptake of FDG showed a similar temporal pattern and increased until 60 min after FDG administration in the RO, IP and IV injection groups. In the PO administration group, tumoral uptake was delayed and reduced. There was no statistical difference among the RO, IP and IV administration groups for additional serial PET scans. RO administration is an effective alternative route to IV administration for mouse FDG PET scans using normal mice and tumor models. In addition, IP administration can be a practical alternative in the late phase, although the initial uptake is lower than those in the IV and RO groups.

  8. Performing Repeated Quantitative Small-Animal PET with an Arterial Input Function Is Routinely Feasible in Rats.

    PubMed

    Huang, Chi-Cheng; Wu, Chun-Hu; Huang, Ya-Yao; Tzen, Kai-Yuan; Chen, Szu-Fu; Tsai, Miao-Ling; Wu, Hsiao-Ming

    2017-04-01

    Performing quantitative small-animal PET with an arterial input function has been considered technically challenging. Here, we introduce a catheterization procedure that keeps a rat physiologically stable for 1.5 mo. We demonstrated the feasibility of quantitative small-animal (18)F-FDG PET in rats by performing it repeatedly to monitor the time course of variations in the cerebral metabolic rate of glucose (CMRglc). Methods: Aseptic surgery was performed on 2 rats. Each rat underwent catheterization of the right femoral artery and left femoral vein. The catheters were sealed with microinjection ports and then implanted subcutaneously. Over the next 3 wk, each rat underwent (18)F-FDG quantitative small-animal PET 6 times. The CMRglc of each brain region was calculated using a 3-compartment model and an operational equation that included a k*4Results: On 6 mornings, we completed 12 (18)F-FDG quantitative small-animal PET studies on 2 rats. The rats grew steadily before and after the 6 quantitative small-animal PET studies. The CMRglc of the conscious brain (e.g., right parietal region, 99.6 ± 10.2 μmol/100 g/min; n = 6) was comparable to that for (14)C-deoxyglucose autoradiographic methods. Conclusion: Maintaining good blood patency in catheterized rats is not difficult. Longitudinal quantitative small-animal PET imaging with an arterial input function can be performed routinely. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  9. Tapered LSO arrays for small animal PET

    NASA Astrophysics Data System (ADS)

    Yang, Yongfeng; St. James, Sara; Wu, Yibao; Du, Huini; Qi, Jinyi; Farrell, Richard; Dokhale, Purushottam A.; Shah, Kanai S.; Vaigneur, Keith; Cherry, Simon R.

    2011-01-01

    By using detectors with good depth encoding accuracy (~2 mm), an animal PET scanner can be built with a small ring diameter and thick crystals to simultaneously obtain high spatial resolution and high sensitivity. However, there will be large wedge-shaped gaps between detector modules in such a scanner if traditional cuboid crystal arrays are used in a polygonal arrangement. The gaps can be minimized by using tapered scintillator arrays enabling the sensitivity of the scanner to be further improved. In this work, tapered lutetium oxyorthosilicate (LSO) arrays with different crystal dimensions and different combinations of inter-crystal reflector and crystal surface treatments were manufactured and their performance was evaluated. Arrays were read out from both ends by position-sensitive avalanche photodiodes (PSAPDs). In the optimal configuration, arrays consisting of 0.5 mm LSO elements could be clearly resolved and a depth of interaction resolution of 2.6 mm was obtained for a 20 mm thick array. For this tapered array, the intrinsic spatial is degraded from 0.67 to 0.75 mm compared to a standard cuboidal array with similar dimensions, while the increase in efficiency is 41%. Tapered scintillator arrays offer the prospect of improvements in sensitivity and sampling for small-bore scanners, without large increases in manufacturing complexity.

  10. Tapered LSO Arrays for Small Animal PET

    PubMed Central

    Yang, Yongfeng; James, Sara St.; Wu, Yibao; Du, Huini; Qi, Jinyi; Farrell, Richard; Dokhale, Purushottam A.; Shah, Kanai S.; Vaigneur, Keith; Cherry, Simon R.

    2011-01-01

    By using detectors with good depth encoding accuracy (~ 2 mm), an animal PET scanner can be built with a small ring diameter and thick crystals to simultaneously obtain high spatial resolution and high sensitivity. However, there will be large wedge-shaped gaps between detector modules in such a scanner if traditional cuboid crystal arrays are used in a polygonal arrangement. The gaps can be minimized by using tapered scintillator arrays enabling the sensitivity of the scanner to be further improved. In this work, tapered lutetium oxyorthosilicate (LSO) arrays with different crystal dimensions and different combinations of inter-crystal reflector and crystal surface treatments were manufactured and their performance was evaluated. Arrays were read out from both ends by position-sensitive avalanche photodiodes (PSAPDs). In the optimal configuration, arrays consisting of 0.5 mm LSO elements could be clearly resolved and a depth of interaction resolution of 2.6 mm was obtained for a 20-mm thick array. For this tapered array, the intrinsic spatial is degraded from 0.67 mm to 0.75 mm compared to a standard cuboidal array with similar dimensions, while the increase in efficiency is 41%. Tapered scintillator arrays offer the prospect of improvements in sensitivity and sampling for small-bore scanners, without large increases in manufacturing complexity. PMID:21119228

  11. Towards very high resolution RPC-PET for small animals

    NASA Astrophysics Data System (ADS)

    Martins, P.; Blanco, A.; Crespo, P.; Fátima Ferreira Marques, M.; Ferreira Marques, R.; Gordo, P. M.; Kajetanowicz, M.; Korcyl, G.; Lopes, L.; Michel, J.; Palka, M.; Traxler, M.; Fonte, P.

    2014-10-01

    We present imaging results of needle-like and planar 22Na sources obtained with a prototype of a high-acceptance small-animal positron emission tomograph based on resistive plate chambers (RPC-PET). The maximum-likelihood expectation-maximization (MLEM) reconstruction of the acquired data yielded an excellent and stable resolution of 0.4 mm FWHM.

  12. Noninvasive Assessment of Myocardial Viability in a Small Animal Model: Comparison of MRI, SPECT, and PET

    PubMed Central

    Thomas, Daniel; Bal, Harshali; Arkles, Jeffrey; Horowitz, James; Araujo, Luis; Acton, Paul D.; Ferrari, Victor A.

    2010-01-01

    Acute myocardial infarction (AMI) research relies increasingly on small animal models and noninvasive imaging methods such as MRI, single-photon emission computed tomography (SPECT), and positron emission tomography (PET). However, a direct comparison among these techniques for characterization of perfusion, viability, and infarct size is lacking. Rats were studied within 18–24 hr post AMI by MRI (4.7 T) and subsequently (40–48 hr post AMI) by SPECT (99Tc-MIBI) and micro-PET (18FDG). A necrosis-specific MRI contrast agent was used to detect AMI, and a fast low angle shot (FLASH) sequence was used to acquire late enhancement and functional images contemporaneously. Infarcted regions showed late enhancement, whereas corresponding radionuclide images had reduced tracer uptake. MRI most accurately depicted AMI, showing the closest correlation and agreement with triphenyl tetrazolium chloride (TTC), followed by SPECT and PET. In some animals a mismatch of reduced uptake in normal myocardium and relatively increased 18FDG uptake in the infarct border zone precluded conventional quantitative analysis. We performed the first quantitative comparison of MRI, PET, and SPECT for reperfused AMI imaging in a small animal model. MRI was superior to the other modalities, due to its greater spatial resolution and ability to detect necrotic myocardium directly. The observed 18FDG mismatch likely represents variable metabolic conditions between stunned myocardium in the infarct border zone and normal myocardium and supports the use of a standardized glucose load or glucose clamp technique for PET imaging of reperfused AMI in small animals. PMID:18228591

  13. Feasibility study of small animal imaging using clinical PET/CT scanner

    NASA Astrophysics Data System (ADS)

    Hsu, Wen-Lin; Chen, Chia-Lin; Wang, Ze-Jing; Wu, Tung-Hsin; Liu, Dai-Wei; Lee, Jason J. S.

    2007-02-01

    The feasibility of small animal imaging using a clinical positron emission tomography/computed tomography (PET/CT) scanner with [F-18]-fluoro-2-deoxy- D-glucose (FDG) was evaluated. Two protocols in PET/CT system, single-mouse high-resolution mode (SHR) and multi-mouse high throughput mode (MHT) protocol were employed to investigate the ability of the scanner and also explored the performance differences between microPET and clinical PET/CT. In this study, we have found that even the clinical PET/CT scanner could not compete with the microPET scanner, especially in spatial resolution; the high-resolution CT image could advance the anatomical information to sub-millimeter level. Besides, CT-based attenuation correction can improve the image uniformity characteristics and quantification accuracy, and the large bore of a human whole-body scanner broadens the possibility of high throughput studies. Considering all the benefits, clinical PET/CT imaging might be a potential alternative for small animal study.

  14. Pet food recalls and pet food contaminants in small animals.

    PubMed

    Bischoff, Karyn; Rumbeiha, Wilson K

    2012-03-01

    Most pet foods are safe, but incidents of chemical contamination occur and lead to illness and recalls. There were 11 major pet food recalls in the United States between 1996 and 2010 that were due to chemical contaminants or misformulations: 3 aflatoxin, 3 excess vitamin D3, 1 excess methionine, 3 inadequate thiamine, and 1 adulteration with melamine and related compounds and an additional 2 warnings concerning a Fanconilike renal syndrome in dogs after ingesting large amounts of chicken jerky treat products. This article describes clinical findings and treatment of animals exposed to the most common pet food contaminants.

  15. Development of a Body Shield for Small Animal PET System to Reduce Random and Scatter Coincidences

    NASA Astrophysics Data System (ADS)

    Wada, Yasuhiro; Yamamoto, Seiichi; Watanabe, Yasuyoshi

    2015-02-01

    For small animal positron emission tomography (PET) research using high radioactivity, such as dynamic studies, the resulting high random coincidence rate of the system degrades image quality. The random coincidence rate is increased not only by the gamma photons from inside the axial-field-of-view (axial-FOV) of the PET system but also by those from outside the axial-FOV. For brain imaging in small animal studies, significant interference is observed from gamma photons emitted from the body. Single gamma photons from the body enter the axial-FOV and increase the random and scatter coincidences. Shielding against the gamma photons from outside the axial-FOV would improve the image quality. For this purpose, we developed a body shield for a small animal PET system, the microPET Primate 4-ring system, and evaluated its performance. The body shield is made of 9-mm-thick lead and it surrounds most of a rat's body. We evaluated the effectiveness of the body shield using a head phantom and a body phantom with a radioactivity concentration ratio of 1:2 and a maximum total activity of approximately 250 MBq. The random coincidence rate was dramatically decreased to 1/10, and the noise equivalent count rate (NECR) was increased 6 times with an activity of 7 MBq in the head phantom. The true count rate was increased to 35% due to the decrease in system deadtime. The average scatter fraction was decreased to 1/2.5 with the body shield. Count rate measurements of rat were also conducted with an injection activity of approximately 25 MBq of [C-11]N,N-dimethyl-2-(2-amino-4-cyanophenylthio) benzylamine ([C-11]DASB) and approximately 70 and 310 MBq of 2-deoxy-2-(F-18)fluoro-D-glucose ([F-18]FDG). Using the body shield, [F-18]FDG images of rats were improved by increasing the amount of radioactivity injected. The body shield designed for small animal PET systems is a promising tool for improving image quality and quantitation accuracy in small animal molecular imaging research.

  16. Preclinical evaluation of the anti-tumor effects of the natural isoflavone genistein in two xenograft mouse models monitored by [18F]FDG, [18F]FLT, and [64Cu]NODAGA-cetuximab small animal PET

    PubMed Central

    Honndorf, Valerie S.; Wiehr, Stefan; Rolle, Anna-Maria; Schmitt, Julia; Kreft, Luisa; Quintanilla-Martinez, Letitia; Kohlhofer, Ursula; Reischl, Gerald; Maurer, Andreas; Boldt, Karsten; Schwarz, Michael; Schmidt, Holger; Pichler, Bernd J.

    2016-01-01

    The natural phytoestrogen genistein is known as protein kinase inhibitor and tumor suppressor in various types of cancers. We studied its antitumor effect in two different xenograft models using positron emission tomography (PET) in vivo combined with ex vivo histology and nuclear magnetic resonance (NMR) metabolic fingerprinting. Procedures A431 and Colo205 tumor-bearing mice were treated with vehicle or genistein (500 mg/kg/d) over a period of 12 days. Imaging was performed with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) and 3′-deoxy-3′-[18F]fluorothymidine ([18F] FLT). In a second study A431 tumor-bearing mice were treated with vehicle, genistein (500 mg/kg/d), cetuximab (1mg/3d) or a combination of the compounds and imaged using [18F]FDG, [18F]FLT and [64Cu]NODAGA-cetuximab. Data were compared to histology and principal components analysis (PCA) of NMR fingerprinting data. Results Genistein reduced tumor growth significantly in both xenografts. [18F] FLT uptake was consistent in both models and corresponded to histological findings and also PCA whereas [18F]FDG and [64Cu]NODAGA-cetuximab were not suitable for therapy monitoring. Conclusions As mono-therapy the natural isoflavone genistein has a powerful therapeutic effect in vivo on A431 and Colo205 tumors. [18F]FLT has superior consistency compared to the other tested tracers in therapy monitoring, while the treatment effect could be shown on the molecular level by histology and metabolic fingerprinting. PMID:27070087

  17. Radiation dose estimate in small animal SPECT and PET.

    PubMed

    Funk, Tobias; Sun, Mingshan; Hasegawa, Bruce H

    2004-09-01

    Calculations of radiation dose are important in assessing the medical and biological implications of ionizing radiation in medical imaging techniques such as SPECT and PET. In contrast, radiation dose estimates of SPECT and PET imaging of small animals are not very well established. For that reason we have estimated the whole-body radiation dose to mice and rats for isotopes such as 18F, 99mTc, 201Tl, (111)In, 123I, and 125I that are used commonly for small animal imaging. We have approximated mouse and rat bodies with uniform soft tissue equivalent ellipsoids. The mouse and rat sized ellipsoids had a mass of 30 g and 300 g, respectively, and a ratio of the principal axes of 1:1:4 and 0.7:1:4. The absorbed fractions for various photon energies have been calculated using the Monte Carlo software package MCNP. Using these values, we then calculated MIRD S-values for two geometries that model the distribution of activity in the animal body: (a) a central point source and (b) a homogeneously distributed source, and compared these values against S-value calculations for small ellipsoids tabulated in MIRD Pamphlet 8 to validate our results. Finally we calculated the radiation dose taking into account the biological half-life of the radiopharmaceuticals and the amount of activity administered. Our calculations produced S-values between 1.06 x 10(-13) Gy/Bq s and 2.77 x 10(-13) Gy/Bq s for SPECT agents, and 15.0 x 10(-13) Gy/Bq s for the PET agent 18F, assuming mouse sized ellipsoids with uniform source distribution. The S-values for a central point source in an ellipsoid are about 10% higher than the values obtained for the uniform source distribution. Furthermore, the S-values for mouse sized ellipsoids are approximately 10 times higher than for the rat sized ellipsoids reflecting the difference in mass. We reviewed published data to obtain administered radioactivity and residence times for small animal imaging. From these values and our computed S-values we estimated

  18. PET performance evaluation of MADPET4: a small animal PET insert for a 7-Tesla MRI scanner.

    PubMed

    Omidvari, Negar; Cabello, Jorge; Topping, Geoffrey; Schneider, Florian Roland; Paul, Stephan; Schwaiger, Markus; Ziegler, Sibylle I

    2017-10-04

    MADPET4 is the first small animal PET insert with two layers of individually read out crystals in combination with silicon photomultiplier technology. It has a novel detector arrangement, in which all crystals face the center of field of view transaxially. In this work, the PET performance of MADPET4 was evaluated and compared to other preclinical PET scanners using the NEMA NU 4 measurements, followed by imaging a mouse-size hot-rod resolution phantom and two in vivo simultaneous PET/MRI scans in a 7-T MRI scanner. The insert had a peak sensitivity of 0.49%, using an energy threshold of 350 keV. A uniform transaxial resolution was obtained up to 15 mm radial offset from the axial center, using filtered back-projection with single-slice rebinning. The measured average radial and tangential resolutions (FWHM) were 1.38 mm and 1.39 mm, respectively. The 1.2 mm rods were separable in the hot-rod phantom using an iterative image reconstruction algorithm. The scatter fraction was 7.3% and peak noise equivalent count rate was 15.5 kcps at 65.1 MBq of activity. The FDG uptake in a mouse heart and brain were visible in the two in vivo simultaneous PET/MRI scans without applying image corrections. In conclusion, the insert demonstrated a good overall performance and can be used for small animal multi-modal research applications. © 2017 Institute of Physics and Engineering in Medicine.

  19. Optimising rigid motion compensation for small animal brain PET imaging

    NASA Astrophysics Data System (ADS)

    Spangler-Bickell, Matthew G.; Zhou, Lin; Kyme, Andre Z.; De Laat, Bart; Fulton, Roger R.; Nuyts, Johan

    2016-10-01

    Motion compensation (MC) in PET brain imaging of awake small animals is attracting increased attention in preclinical studies since it avoids the confounding effects of anaesthesia and enables behavioural tests during the scan. A popular MC technique is to use multiple external cameras to track the motion of the animal’s head, which is assumed to be represented by the motion of a marker attached to its forehead. In this study we have explored several methods to improve the experimental setup and the reconstruction procedures of this method: optimising the camera-marker separation; improving the temporal synchronisation between the motion tracker measurements and the list-mode stream; post-acquisition smoothing and interpolation of the motion data; and list-mode reconstruction with appropriately selected subsets. These techniques have been tested and verified on measurements of a moving resolution phantom and brain scans of an awake rat. The proposed techniques improved the reconstructed spatial resolution of the phantom by 27% and of the rat brain by 14%. We suggest a set of optimal parameter values to use for awake animal PET studies and discuss the relative significance of each parameter choice.

  20. Automated Method for Small-Animal PET Image Registration with Intrinsic Validation

    PubMed Central

    Pascau, Javier; Gispert, Juan Domingo; Michaelides, Michael; Thanos, Panayotis K.; Volkow, Nora D.; Vaquero, Juan José; Soto-Montenegro, Maria Luisa; Desco, Manuel

    2009-01-01

    Purpose: We propose and compare different registration approaches to align small-animal PET studies and a procedure to validate the results by means of objective registration consistency measurements. Procedures: We have applied a registration algorithm based on information theory, using different approaches to mask the reference image. The registration consistency allows for the detection of incorrect registrations. This methodology has been evaluated on a test dataset (FDG-PET rat brain images). Results: The results show that a multiresolution two-step registration approach based on the use of the whole image at the low resolution step, while masking the brain at the high resolution step, provides the best robustness (87.5% registration success) and highest accuracy (0.67-mm average). Conclusions: The major advantages of our approach are minimal user interaction and automatic assessment of the registration error, avoiding visual inspection of the results, thus facilitating the accurate, objective, and rapid analysis of large groups of rodent PET images. PMID:18670824

  1. Development of a PET Scanner for Simultaneously Imaging Small Animals with MRI and PET

    PubMed Central

    Thompson, Christopher J; Goertzen, Andrew L; Thiessen, Jonathan D; Bishop, Daryl; Stortz, Greg; Kozlowski, Piotr; Retière, Fabrice; Zhang, Xuezhu; Sossi, Vesna

    2014-01-01

    Recently, positron emission tomography (PET) is playing an increasingly important role in the diagnosis and staging of cancer. Combined PET and X-ray computed tomography (PET-CT) scanners are now the modality of choice in cancer treatment planning. More recently, the combination of PET and magnetic resonance imaging (MRI) is being explored in many sites. Combining PET and MRI has presented many challenges since the photo-multiplier tubes (PMT) in PET do not function in high magnetic fields, and conventional PET detectors distort MRI images. Solid state light sensors like avalanche photo-diodes (APDs) and more recently silicon photo-multipliers (SiPMs) are much less sensitive to magnetic fields thus easing the compatibility issues. This paper presents the results of a group of Canadian scientists who are developing a PET detector ring which fits inside a high field small animal MRI scanner with the goal of providing simultaneous PET and MRI images of small rodents used in pre-clinical medical research. We discuss the evolution of both the crystal blocks (which detect annihilation photons from positron decay) and the SiPM array performance in the last four years which together combine to deliver significant system performance in terms of speed, energy and timing resolution. PMID:25120157

  2. Geo-PET: A novel generic organ-pet for small animal organs and tissues

    NASA Astrophysics Data System (ADS)

    Sensoy, Levent

    Reconstructed tomographic image resolution of small animal PET imaging systems is improving with advances in radiation detector development. However the trend towards higher resolution systems has come with an increase in price and system complexity. Recent developments in the area of solid-state photomultiplication devices like silicon photomultiplier arrays (SPMA) are creating opportunities for new high performance tools for PET scanner design. Imaging of excised small animal organs and tissues has been used as part of post-mortem studies in order to gain detailed, high-resolution anatomical information on sacrificed animals. However, this kind of ex-vivo specimen imaging has largely been limited to ultra-high resolution muCT. The inherent limitations to PET resolution have, to date, excluded PET imaging from these ex-vivo imaging studies. In this work, we leverage the diminishing physical size of current generation SPMA designs to create a very small, simple, and high-resolution prototype detector system targeting ex-vivo tomographic imaging of small animal organs and tissues. We investigate sensitivity, spatial resolution, and the reconstructed image quality of a prototype small animal PET scanner designed specifically for imaging of excised murine tissue and organs. We aim to demonstrate that a cost-effective silicon photomultiplier (SiPM) array based design with thin crystals (2 mm) to minimize depth of interaction errors might be able to achieve sub-millimeter resolution. We hypothesize that the substantial decrease in sensitivity associated with the thin crystals can be compensated for with increased solid angle detection, longer acquisitions, higher activity and wider acceptance energy windows (due to minimal scatter from excised organs). The constructed system has a functional field of view (FoV) of 40 mm diameter, which is adequate for most small animal specimen studies. We perform both analytical (3D-FBP) and iterative (ML-EM) methods in order to

  3. Innovations in Small-Animal PET/MR Imaging Instrumentation.

    PubMed

    Tsoumpas, Charalampos; Visvikis, Dimitris; Loudos, George

    2016-04-01

    Multimodal imaging has led to a more detailed exploration of different physiologic processes with integrated PET/MR imaging being the most recent entry. Although the clinical need is still questioned, it is well recognized that it represents one of the most active and promising fields of medical imaging research in terms of software and hardware. The hardware developments have moved from small detector components to high-performance PET inserts and new concepts in full systems. Conversely, the software focuses on the efficient performance of necessary corrections without the use of CT data. The most recent developments in both directions are reviewed. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Performance of a PET Insert for High Resolution Small Animal PET/MR Imaging at 7T.

    PubMed

    Stortz, Greg; Thiessen, Jonathan D; Bishop, Daryl; Khan, Muhammad S; Kozlowski, Piotr; Retière, Fabrice; Schellenberg, Graham; Shams, Ehsan; Zhang, Xuezhu; Thompson, Christopher J; Goertzen, Andrew; Sossi, Vesna

    2017-09-14

    We present the characterization of a compact magnetic resonance (MR) compatible positron emission tomography (PET) insert for simultaneous pre-clinical PET/MR imaging. While specifically designed with the strict size constraint to fit inside the 114 mm inner diameter of the BGA-12S gradient coil used in the Bruker 70/20 and 94/20 series of small animal MR imaging (MRI) systems, the insert can be easily installed in any appropriate MRI scanner or used as a stand-alone PET system. Methods: The insert is made from a ring of 16 detector-blocks each made from depth-of-interaction capable dual-layer-offset arrays of cerium-doped lutetium-yttrium oxyorthosilicate crystals read out by silicon photomultiplier (SiPM) arrays. Scintillator crystal arrays are made from 22×10 / 21×9 crystals in the bottom/top layers with 6/4 mm layer thicknesses, arranged with a 1.27 mm pitch, resulting in a useable field of view (FOV) 28 mm long and ~55 mm wide. Results: Spatial resolution ranges from 1.17 to 1.86 mm full-width-at-half-maximum (FWHM) in the radial direction from a radial offset of 0 to 15 mm. With a 300-800 keV energy window, peak sensitivity is 2.2% and noise-equivalent count rate (NECR) from a mouse-sized phantom at 3.7 MBq is 11.1 kcps and peaks at 20.8 kcps at 14.5 MBq. Phantom imaging shows that feature sizes as low as 0.7 mm can be resolved. (18)F-fluorodeoxyglucose ((18)F-FDG) PET/MR images of mouse and rat brains show no signs of inter-modality interference, and can excellently resolve substructures within the brains. Conclusion: Due to excellent spatial resolvability and lack of intermodality interference, this PET insert will serve as a useful tool for pre-clinical PET/MR. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  5. FDG PET Imaging in Pneumocystis Pneumonia.

    PubMed

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

    2015-08-01

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

  6. Markerless rat head motion tracking using structured light for brain PET imaging of unrestrained awake small animals

    NASA Astrophysics Data System (ADS)

    Miranda, Alan; Staelens, Steven; Stroobants, Sigrid; Verhaeghe, Jeroen

    2017-03-01

    Preclinical positron emission tomography (PET) imaging in small animals is generally performed under anesthesia to immobilize the animal during scanning. More recently, for rat brain PET studies, methods to perform scans of unrestrained awake rats are being developed in order to avoid the unwanted effects of anesthesia on the brain response. Here, we investigate the use of a projected structure stereo camera to track the motion of the rat head during the PET scan. The motion information is then used to correct the PET data. The stereo camera calculates a 3D point cloud representation of the scene and the tracking is performed by point cloud matching using the iterative closest point algorithm. The main advantage of the proposed motion tracking is that no intervention, e.g. for marker attachment, is needed. A manually moved microDerenzo phantom experiment and 3 awake rat [18F]FDG experiments were performed to evaluate the proposed tracking method. The tracking accuracy was 0.33 mm rms. After motion correction image reconstruction, the microDerenzo phantom was recovered albeit with some loss of resolution. The reconstructed FWHM of the 2.5 and 3 mm rods increased with 0.94 and 0.51 mm respectively in comparison with the motion-free case. In the rat experiments, the average tracking success rate was 64.7%. The correlation of relative brain regional [18F]FDG uptake between the anesthesia and awake scan reconstructions was increased from on average 0.291 (not significant) before correction to 0.909 (p  <  0.0001) after motion correction. Markerless motion tracking using structured light can be successfully used for tracking of the rat head for motion correction in awake rat PET scans.

  7. Development of an ultrahigh resolution Si-PM based PET system for small animals.

    PubMed

    Yamamoto, Seiichi; Watabe, Hiroshi; Kanai, Yasukazu; Watabe, Tadashi; Kato, Katsuhiko; Hatazawa, Jun

    2013-11-07

    Since a high resolution PET system is needed for small animal imaging, especially for mouse studies, we developed a new small animal PET system that decreased the size of the scintillators to less than 1 mm. Our developed PET system used 0.5 × 0.7 × 5 mm(3) LYSO pixels arranged in an 11 × 13 matrix to form a block with a 0.1 mm BaSO4 reflector between the pixels. Two LYSO blocks were optically coupled to two optical fiber based angled image guides. These LYSO blocks and image guides were coupled to a Si-PM array (Hamamatsu MPPC S11064-050P) to form a block detector. Eight block detectors (16 LYSO blocks) were arranged in a 34 mm inner diameter ring to form a small animal PET system. The block detector showed good separation for the 22 × 13 LYSO pixels in the two-dimensional position histogram. The energy resolution was 20% full-with at half-maximum (FWHM) for 511 keV gamma photons. The transaxial resolution reconstructed by filtered backprojection was 0.71 to 0.75 mm FWHM and the axial resolution was 0.70 mm. The point source sensitivity was 0.24% at the central axial field-of-view. High resolution mouse images were obtained using our PET system. The developed ultrahigh resolution PET system showed attractive images for small animal studies and has a potential to provide new findings in molecular imaging researches.

  8. FDG PET/CT in bone sarcoidosis.

    PubMed

    Grozdic Milojevic, Isidora; Sobic-Saranovic, Dragana; Videnovic-Ivanov, Jelica; Saranovic, Djordjije; Odalovic, Strahinja; Artiko, Vera

    2016-03-29

    Bone sarcoidosis is rare manifestation of disease usually accompanied with pulmonary involvement. Until today, exact prevalence of bone sarcoidosis is not known, since reported prevalence varies widely depending on the studied population and the used diagnostic techniques. To determine the prevalence of bone involvement and distribution pattern in active chronic sarcoidosis by using FDG PET/CT. Between January 2010 and December 2011, 98 patients with chronic sarcoidosis and presence of prolonged symptoms or other findings suggestive of active disease were referred to FDG PET/CT examination. Active disease was found in 82 patients, and they all were screened for presence of bone sarcoidosis on FDG PET/CT. All patients also underwent MDCT and assessment of serum ACE level. Bone sarcoidosis was present in 18/82 patients with active sarcoidosis. FDG uptake in bones was focal in 8 (44.4%), diffuse in 6 (33.3%) and both diffuse and focal in 4 (22.2%) patients. CT indicated bone abnormalities only in 5% patients. Osseous involvement was present in: pelvis (61.1%), vertebrae (44.4%), ribs (27.8%) and bone marrow (16.7%). Some patients had two or more locations of disease. Follow-up FDG PET/CT showed normal findings in two patients, same localization of active disease in four patients and progression of disease in one. In patients with active chronic sarcoidosis 22% of patients had osseous abnormalities on FDG PET/CT that mostly were not detected on CT.

  9. A combined micro-PET/CT scanner for small animal imaging

    NASA Astrophysics Data System (ADS)

    Jan, Meei-Ling; Ni, Yu-Ching; Chen, Kuo-Wei; Liang, Hsing-Ching; Chuang, Keh-Shih; Fu, Ying-Kai

    2006-12-01

    A micro-PET/CT system was developed by combination of an in-house micro-CT and a microPET ® R4 scanner. The cone-beam micro-CT consists of a rotational gantry that fits an X-ray tube, a CCD-based X-ray detector, and motor-driven linear stages. The gantry was designed to be coaxial with the scanner of microPET ® R4. It can be moved for the convenience of mounting the Ge-68 point-source holder for PET's calibration. The image volumes obtained from two modalities is registered by a pre-determined, inherent spatial transformation function. This hardware-approach fusion, which provides accurate and no labor-intensive alignment, is suitable for mass scanning. The micro-PET/CT system has been operated successfully. Merging the anatomical and functional images benefit studies of the small animal imaging.

  10. Small animal PET scanner based on monolithic LYSO crystals: performance evaluation.

    PubMed

    Sanchez, F; Moliner, L; Correcher, C; Gonzalez, A; Orero, A; Carles, M; Soriano, A; Rodriguez-Alvarez, M J; Medina, L A; Mora, F; Benlloch, J M

    2012-02-01

    The authors have developed a small animal Positron emission tomography (PET) scanner based on monolithic LYSO crystals coupled to multi-anode photomultiplier tubes (MA-PMTs). In this study, the authors report on the design, calibration procedure, and performance evaluation of a PET system that the authors have developed using this innovative nonpixelated detector design. The scanner is made up of eight compact modules forming an octagon with an axial field of view (FOV) of 40 mm and a transaxial FOV of 80 mm diameter. In order to fully determine its performance, a recently issued National Electrical Manufacturers Association (NEMA) NU-4 protocol, specifically developed for small animal PET scanners, has been followed. By measuring the width of light distribution collected in the MA-PMT the authors are able to determine depth of interaction (DOI), thus making the proper identification of lines of response (LORs) with large incidence angles possible. PET performances are compared with those obtained with currently commercially available small animal PET scanners. At axial center when the point-like source is located at 5 mm from the radial center, the spatial resolution measured was 1.65, 1.80, and 1.86 mm full width at half maximum (FWHM) for radial, tangential, and axial image profiles, respectively. A system scatter fraction of 7.5% (mouse-like phantom) and 13% (rat-like phantom) was obtained, while the maximum noise equivalent count rate (NECR) was 16.9 kcps at 12.7 MBq (0.37 MBq/ml) for mouse-like phantom and 12.8 kcps at 12.4 MBq (0.042 MBq/ml) for rat-like phantom The peak absolute sensitivity in the center of the FOV is 2% for a 30% peak energy window. Several animal images are also presented. The overall performance of our small animal PET is comparable to that obtained with much more complex crystal pixelated PET systems. Moreover, the new proposed PET produces high-quality images suitable for studies with small animals.

  11. Towards a high sensitivity small animal PET system based on CZT detectors (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Abbaszadeh, Shiva; Levin, Craig

    2017-03-01

    Small animal positron emission tomography (PET) is a biological imaging technology that allows non-invasive interrogation of internal molecular and cellular processes and mechanisms of disease. New PET molecular probes with high specificity are under development to target, detect, visualize, and quantify subtle molecular and cellular processes associated with cancer, heart disease, and neurological disorders. However, the limited uptake of these targeted probes leads to significant reduction in signal. There is a need to advance the performance of small animal PET system technology to reach its full potential for molecular imaging. Our goal is to assemble a small animal PET system based on CZT detectors and to explore methods to enhance its photon sensitivity. In this work, we reconstruct an image from a phantom using a two-panel subsystem consisting of six CZT crystals in each panel. For image reconstruction, coincidence events with energy between 450 and 570 keV were included. We are developing an algorithm to improve sensitivity of the system by including multiple interaction events.

  12. Design and performance from an integrated PET/MRI system for small animals.

    PubMed

    Yamamoto, Seiichi; Imaizumi, Masao; Kanai, Yasukazu; Tatsumi, Mitsuaki; Aoki, Masaaki; Sugiyama, Eiji; Kawakami, Makoto; Shimosegawa, Eku; Hatazawa, Jun

    2010-02-01

    Although simultaneous measurements of PET and magnetic resonance imaging (MRI) can provide interesting results in molecular imaging research, most of the combined systems are huge and animal handling in the system is not easy. To minimize these problems, we developed a compact integrated PET/MRI (iPET/MRI) system for small animals. For the iPET/MRI system, a new MR-compatible PET and a permanent magnet open MRI were designed. In the MRI, a tunnel is opened at the yoke of the magnet. The position-sensitive photo-multiplier tubes (PSPMTs) of the MR-compatible PET are positioned at the back of the yoke where the magnetic field is sufficiently low. The scintillators for the PET system are positioned at the center of the MRI magnets, and the direction of the scintillation photons is changed by slanted light guides, and they are fed to the PSPMTs by 75 cm long optical fiber bundles. The PET detectors employed two types of LGSO crystals (1.9 mm x 2.2 mm x 6 mm and 7 mm) with different decay times (33 and 43 ns) for depth of interaction detection. Sixteen optical fiber-based block detectors are arranged in a 112 mm diameter ring. The transaxial field-of-view (FOV) of the PET system is ~80 mm, and the axial FOV is 21 mm which can be enlarged by the axial motion of the PET detector ring during MRI acquisition. The transaxial and axial resolutions at the center of the PET system was 2.9 and 2.4 mm FWHM, respectively. The absolute sensitivity was 1.5% at the center of the axial FOV. Phantom images revealed no artifact in either the PET or MRI images. We successfully obtained simultaneously measured small animal images using the iPET/MRI system. The open geometry of the developed iPET/ MRI facilitates easy accessibility to the subject. The iPET/ MRI system appears to be a promising tool for molecular imaging research.

  13. Simultaneous Multiparametric PET/MRI with Silicon Photomultiplier PET and Ultra-High-Field MRI for Small-Animal Imaging.

    PubMed

    Ko, Guen Bae; Yoon, Hyun Suk; Kim, Kyeong Yun; Lee, Min Sun; Yang, Bo Yeun; Jeong, Jae Min; Lee, Dong Soo; Song, In Chan; Kim, Seok-Ki; Kim, Daehong; Lee, Jae Sung

    2016-08-01

    Visualization of biologic processes at molecular and cellular levels has revolutionized the understanding and treatment of human diseases. However, no single biomedical imaging modality provides complete information, resulting in the emergence of multimodal approaches. Combining state-of-the-art PET and MRI technologies without loss of system performance and overall image quality can provide opportunities for new scientific and clinical innovations. Here, we present a multiparametric PET/MR imager based on a small-animal dedicated, high-performance, silicon photomultiplier (SiPM) PET system and a 7-T MR scanner. A SiPM-based PET insert that has the peak sensitivity of 3.4% and center volumetric resolution of 1.92/0.53 mm(3) (filtered backprojection/ordered-subset expectation maximization) was developed. The SiPM PET insert was placed between the mouse body transceiver coil and gradient coil of a 7-T small-animal MRI scanner for simultaneous PET/MRI. Mutual interference between the MRI and SiPM PET systems was evaluated using various MR pulse sequences. A cylindric corn oil phantom was scanned to assess the effects of the SiPM PET on the MR image acquisition. To assess the influence of MRI on the PET imaging functions, several PET performance indicators including scintillation pulse shape, flood image quality, energy spectrum, counting rate, and phantom image quality were evaluated with and without the application of MR pulse sequences. Simultaneous mouse PET/MRI studies were also performed to demonstrate the potential and usefulness of the multiparametric PET/MRI in preclinical applications. Excellent performance and stability of the PET system were demonstrated, and the PET/MRI combination did not result in significant image quality degradation of either modality. Finally, simultaneous PET/MRI studies in mice demonstrated the feasibility of the developed system for evaluating the biochemical and cellular changes in a brain tumor model and facilitating the

  14. FDG-PET evaluation of pleural abnormalities

    SciTech Connect

    Lowe, V.J.; Patz, E.; Harris, P.L.

    1994-05-01

    Pleural abnormalities identified on anatomical studies are often nonspecific and may represent benign or malignant disease. We prospectively evaluated the ability of FDG-PET to identify malignancy in patients with pleural abnormalities detected on chest radiographs or chest CT. Thirty-two patients with pleural abnormalities (pleural masses, thickening or effusions) found on chest radiographs or CT were evaluated by FDG-PET. Regions of interest (ROI) were identified on the PET images correlating to anatomic abnormalities and standard uptake ratios (SUR`s) of these ROI`s were calculated. A SUR value of 2.5 or greater was considered positive for malignancy. Physicians blinded to biopsy results graded their confidence of malignancy (1-5 scale) and graded lesion FDG uptake with respect to mediastinal radioactivity. Twenty-three of the patients had definitive diagnoses by tissue biopsy. Seventeen of these patients had malignant (SUR=7.9{plus_minus}3.8) and 6 had benign (SUR=2.8{plus_minus}2.4) causes of their pleural abnormalities (p=0.001). All but two malignant cases had SURs higher than 2.5 and one of these two was correctly interpreted by the observers. SURs lower than 2.5 were seen in four of the six (67%) benign pleural abnormalities. Using a combination of both visual and semiquantitative analysis, the sensitivity of FDG-PET for detecting malignant pleural abnormalities was 94%. Active infections in the pleural space had increased FDG uptake on PET studies while other benign pleural abnormalities did not. FDG-PET has very high sensitivity for detecting malignant pleural abnormalities and can differentiate benign from malignant pleural abnormalities.

  15. Real-time 3D motion tracking for small animal brain PET

    NASA Astrophysics Data System (ADS)

    Kyme, A. Z.; Zhou, V. W.; Meikle, S. R.; Fulton, R. R.

    2008-05-01

    High-resolution positron emission tomography (PET) imaging of conscious, unrestrained laboratory animals presents many challenges. Some form of motion correction will normally be necessary to avoid motion artefacts in the reconstruction. The aim of the current work was to develop and evaluate a motion tracking system potentially suitable for use in small animal PET. This system is based on the commercially available stereo-optical MicronTracker S60 which we have integrated with a Siemens Focus-220 microPET scanner. We present measured performance limits of the tracker and the technical details of our implementation, including calibration and synchronization of the system. A phantom study demonstrating motion tracking and correction was also performed. The system can be calibrated with sub-millimetre accuracy, and small lightweight markers can be constructed to provide accurate 3D motion data. A marked reduction in motion artefacts was demonstrated in the phantom study. The techniques and results described here represent a step towards a practical method for rigid-body motion correction in small animal PET. There is scope to achieve further improvements in the accuracy of synchronization and pose measurements in future work.

  16. Efficient system modeling for a small animal PET scanner with tapered DOI detectors

    PubMed Central

    Zhang, Mengxi; Zhou, Jian; Yang, Yongfeng; Rodríguez-Villafuerte, Mercedes; Qi, Jinyi

    2016-01-01

    A prototype small animal positron emission tomography (PET) scanner for mouse brain imaging has been developed at UC Davis. The new scanner uses tapered detector arrays with depth of interaction (DOI) measurement. In this paper, we present an efficient system model for the tapered PET scanner using matrix factorization and a virtual scanner geometry. The factored system matrix mainly consists of two components: a sinogram blurring matrix and a geometrical matrix. The geometric matrix is based on a virtual scanner geometry. The sinogram blurring matrix is estimated by matrix factorization. We investigate the performance of different virtual scanner geometries. Both simulation study and real data experiments are performed in the fully 3D mode to study the image quality under different system models. The results indicate that the proposed matrix factorization can maintain image quality while substantially reduce the image reconstruction time and system matrix storage cost. The proposed method can be also applied to other PET scanners with DOI measurement. PMID:26682623

  17. Efficient system modeling for a small animal PET scanner with tapered DOI detectors.

    PubMed

    Zhang, Mengxi; Zhou, Jian; Yang, Yongfeng; Rodríguez-Villafuerte, Mercedes; Qi, Jinyi

    2016-01-21

    A prototype small animal positron emission tomography (PET) scanner for mouse brain imaging has been developed at UC Davis. The new scanner uses tapered detector arrays with depth of interaction (DOI) measurement. In this paper, we present an efficient system model for the tapered PET scanner using matrix factorization and a virtual scanner geometry. The factored system matrix mainly consists of two components: a sinogram blurring matrix and a geometrical matrix. The geometric matrix is based on a virtual scanner geometry. The sinogram blurring matrix is estimated by matrix factorization. We investigate the performance of different virtual scanner geometries. Both simulation study and real data experiments are performed in the fully 3D mode to study the image quality under different system models. The results indicate that the proposed matrix factorization can maintain image quality while substantially reduce the image reconstruction time and system matrix storage cost. The proposed method can be also applied to other PET scanners with DOI measurement.

  18. Efficient system modeling for a small animal PET scanner with tapered DOI detectors

    NASA Astrophysics Data System (ADS)

    Zhang, Mengxi; Zhou, Jian; Yang, Yongfeng; Rodríguez-Villafuerte, Mercedes; Qi, Jinyi

    2016-01-01

    A prototype small animal positron emission tomography (PET) scanner for mouse brain imaging has been developed at UC Davis. The new scanner uses tapered detector arrays with depth of interaction (DOI) measurement. In this paper, we present an efficient system model for the tapered PET scanner using matrix factorization and a virtual scanner geometry. The factored system matrix mainly consists of two components: a sinogram blurring matrix and a geometrical matrix. The geometric matrix is based on a virtual scanner geometry. The sinogram blurring matrix is estimated by matrix factorization. We investigate the performance of different virtual scanner geometries. Both simulation study and real data experiments are performed in the fully 3D mode to study the image quality under different system models. The results indicate that the proposed matrix factorization can maintain image quality while substantially reduce the image reconstruction time and system matrix storage cost. The proposed method can be also applied to other PET scanners with DOI measurement.

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

    NASA Astrophysics Data System (ADS)

    Kang, Jihoon; Choi, Yong; Hong, Key Jo; Hu, Wei; Jung, Jin Ho; Huh, Yoonsuk; Kim, Byung-Tae

    2011-08-01

    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.

  20. Evaluation of attenuation and scatter correction requirements in small animal PET and SPECT imaging

    NASA Astrophysics Data System (ADS)

    Konik, Arda Bekir

    Positron emission tomography (PET) and single photon emission tomography (SPECT) are two nuclear emission-imaging modalities that rely on the detection of high-energy photons emitted from radiotracers administered to the subject. The majority of these photons are attenuated (absorbed or scattered) in the body, resulting in count losses or deviations from true detection, which in turn degrades the accuracy of images. In clinical emission tomography, sophisticated correction methods are often required employing additional x-ray CT or radionuclide transmission scans. Having proven their potential in both clinical and research areas, both PET and SPECT are being adapted for small animal imaging. However, despite the growing interest in small animal emission tomography, little scientific information exists about the accuracy of these correction methods on smaller size objects, and what level of correction is required. The purpose of this work is to determine the role of attenuation and scatter corrections as a function of object size through simulations. The simulations were performed using Interactive Data Language (IDL) and a Monte Carlo based package, Geant4 application for emission tomography (GATE). In IDL simulations, PET and SPECT data acquisition were modeled in the presence of attenuation. A mathematical emission and attenuation phantom approximating a thorax slice and slices from real PET/CT data were scaled to 5 different sizes (i.e., human, dog, rabbit, rat and mouse). The simulated emission data collected from these objects were reconstructed. The reconstructed images, with and without attenuation correction, were compared to the ideal (i.e., non-attenuated) reconstruction. Next, using GATE, scatter fraction values (the ratio of the scatter counts to the total counts) of PET and SPECT scanners were measured for various sizes of NEMA (cylindrical phantoms representing small animals and human), MOBY (realistic mouse/rat model) and XCAT (realistic human model

  1. A rat head holder for simultaneous scanning of two rats in small animal PET scanners: design, construction, feasibility testing and kinetic validation.

    PubMed

    Cheng, Tee Ean; Yoder, Karmen K; Normandin, Marc D; Risacher, Shannon L; Converse, Alexander K; Hampel, Joseph A; Miller, Michael A; Morris, Evan D

    2009-01-15

    To reduce imaging costs, we designed a head holder for scanning two rats simultaneously in small animal PET scanners. Our goals were (i) to maintain high sensitivity and (ii) to minimize repositioning error between scans. A semi-stereotaxic dual rat head holder was designed and constructed for dual rat scanning in our IndyPET-II scanner and the commercial microPET P4. It was also used for single rat scanning in a small-bore, high-resolution animal scanner ("ISAP"). Positional repeatability was validated via multiple [11C]Raclopride scans of a single rat on different days. Accuracy of repositioning was determined by visual comparison of images, and by metrics derived through image alignment. Kinetic validation was assessed via analysis of [18F]Fluorodeoxyglucose ([18F]FDG) dynamic PET studies of six rats. Each rat was scanned twice: once individually, with brain positioned at the center of field of view (CFOV), and once with a partner, with brain away from CFOV. Both rats were injected with FDG during each dual rat session. Patlak uptake constants (Ki) were calculated from whole brain images. Effects of attenuation and scatter correction on single versus dual scan images were explored. Image comparison and alignment metrics indicated excellent repositioning of rats. Scaled time-activity-curves from single and dual rat scans were indistinguishable. Average single and dual scan Ki values differed by only 6.3+/-7.5%. Dual rat scanning in a semi-stereotaxic holder is practical for economical small animal scanning and does not compromise kinetic accuracy of [18F]FDG dynamic scan data.

  2. Automatic Cardiac Self-Gating of Small-Animal PET Data.

    PubMed

    Herraiz, Joaquin L; Herranz, Elena; Cal-González, Jacobo; Vaquero, Juan J; Desco, Manuel; Cussó, Lorena; Udias, Jose M

    2016-02-01

    The cardiac gating signal (CGS) in positron emission tomography (PET) studies is usually obtained from an electrocardiography (ECG) monitor. In this work, we propose a method to obtain the CGS in small-animal PET using the acquired list-mode data without using any hardware or end-user input. The CGS was obtained from the number of coincidences over time acquired in the lines-of-response connected with the cardiac region. This region is identified in the image as its value changes with frequencies in the range of 3 to 12 Hz. The procedure was tested in a study with 29 Wistar rats and 6 mice injected with 2-deoxy-2-[(18)F]fluoro-D-glucose, which underwent a 45-min single-bed list-mode PET scan of the heart syncronized with an ECG. The estimated signals and the reconstructed images using eight-gated frames were compared with the ones obtained using the ECG signal from the monitor. The differences of the PET-based CGS with respect to the ECG relative to the duration of the heartbeats were 5.6 % in rats and 11.0 % in mice. The reconstructed gated images obtained from the proposed method do not differ qualitatively with respect to the ones obtained with the ECG. The quantitative analysis of both set of images were performed measuring the volume of the left ventricle (LV) of the rats in the end-of-systole and end-of-diastole phase. The differences found in these parameters between both methods were below 12.1 % in the ESV and 9.3 % in the EDV with a 95 % confidence interval, which are comparable to the accuracy (7 %) of the method used for segmenting the LV. The proposed method is able to provide a valid and accurate CGS in small-animal PET list-mode data.

  3. Performance evaluation of a very high resolution small animal PET imager using silicon scatter detectors

    NASA Astrophysics Data System (ADS)

    Park, Sang-June; Rogers, W. Leslie; Huh, Sam; Kagan, Harris; Honscheid, Klaus; Burdette, Don; Chesi, Enrico; Lacasta, Carlos; Llosa, Gabriela; Mikuz, Marko; Studen, Andrej; Weilhammer, Peter; Clinthorne, Neal H.

    2007-05-01

    A very high resolution positron emission tomography (PET) scanner for small animal imaging based on the idea of inserting a ring of high-granularity solid-state detectors into a conventional PET scanner is under investigation. A particularly interesting configuration of this concept, which takes the form of a degenerate Compton camera, is shown capable of providing sub-millimeter resolution with good sensitivity. We present a Compton PET system and estimate its performance using a proof-of-concept prototype. A prototype single-slice imaging instrument was constructed with two silicon detectors 1 mm thick, each having 512 1.4 mm × 1.4 mm pads arranged in a 32 × 16 array. The silicon detectors were located edgewise on opposite sides and flanked by two non-position sensitive BGO detectors. The scanner performance was measured for its sensitivity, energy, timing, spatial resolution and resolution uniformity. Using the experimental scanner, energy resolution for the silicon detectors is 1%. However, system energy resolution is dominated by the 23% FWHM BGO resolution. Timing resolution for silicon is 82.1 ns FWHM due to time-walk in trigger devices. Using the scattered photons, time resolution between the BGO detectors is 19.4 ns FWHM. Image resolution of 980 µm FWHM at the center of the field-of-view (FOV) is obtained from a 1D profile of a 0.254 mm diameter 18F line source image reconstructed using the conventional 2D filtered back-projection (FBP). The 0.4 mm gap between two line sources is resolved in the image reconstructed with both FBP and the maximum likelihood expectation maximization (ML-EM) algorithm. The experimental instrument demonstrates sub-millimeter resolution. A prototype having sensitivity high enough for initial small animal images can be used for in vivo studies of small animal models of metabolism, molecular mechanism and the development of new radiotracers.

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

    PubMed

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

    2010-10-07

    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 × 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 × 1.2 mm × 5 mm) and 0.025 mol% Ce (decay time: ∼31 ns; 1.1 mm × 1.2 mm × 6 mm) were optically coupled in the DOI direction to form a DOI detector, arranged in a 11 × 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.

  5. Practical method for radioactivity distribution analysis in small-animal PET cancer studies

    PubMed Central

    Slavine, Nikolai V.; Antich, Peter P.

    2008-01-01

    We present a practical method for radioactivity distribution analysis in small-animal tumors and organs using positron emission tomography imaging with a calibrated source of known activity and size in the field of view. We reconstruct the imaged mouse together with a source under the same conditions, using an iterative method, Maximum Likelihood Expectation-Maximization with System Modeling, capable of delivering high resolution images. Corrections for the ratios of geometrical efficiencies, radioisotope decay in time and photon attenuation are included in the algorithm. We demonstrate reconstruction results for the amount of radioactivity within the scanned mouse in a sample study of osteolytic and osteoblastic bone metastasis from prostate cancer xenografts. Data acquisition was performed on the small-animal PET system which was tested with different radioactive sources, phantoms and animals to achieve high sensitivity and spatial resolution. Our method uses high resolution images to determine the volume of organ or tumor and the amount of their radioactivity, has the possibility of saving time, effort and the necessity to sacrifice animals. This method has utility for prognosis and quantitative analysis in small-animal cancer studies, and will enhance the assessment of characteristics of tumor growth, identifying metastases, and potentially determining the effectiveness of cancer treatment. The possible application for this technique could be useful for the organ radioactivity dosimetry studies. PMID:18667322

  6. Correction of MRI-induced geometric distortions in whole-body small animal PET-MRI

    SciTech Connect

    Frohwein, Lynn J. Schäfers, Klaus P.; Hoerr, Verena; Faber, Cornelius

    2015-07-15

    Purpose: The fusion of positron emission tomography (PET) and magnetic resonance imaging (MRI) data can be a challenging task in whole-body PET-MRI. The quality of the registration between these two modalities in large field-of-views (FOV) is often degraded by geometric distortions of the MRI data. The distortions at the edges of large FOVs mainly originate from MRI gradient nonlinearities. This work describes a method to measure and correct for these kind of geometric distortions in small animal MRI scanners to improve the registration accuracy of PET and MRI data. Methods: The authors have developed a geometric phantom which allows the measurement of geometric distortions in all spatial axes via control points. These control points are detected semiautomatically in both PET and MRI data with a subpixel accuracy. The spatial transformation between PET and MRI data is determined with these control points via 3D thin-plate splines (3D TPS). The transformation derived from the 3D TPS is finally applied to real MRI mouse data, which were acquired with the same scan parameters used in the phantom data acquisitions. Additionally, the influence of the phantom material on the homogeneity of the magnetic field is determined via field mapping. Results: The spatial shift according to the magnetic field homogeneity caused by the phantom material was determined to a mean of 0.1 mm. The results of the correction show that distortion with a maximum error of 4 mm could be reduced to less than 1 mm with the proposed correction method. Furthermore, the control point-based registration of PET and MRI data showed improved congruence after correction. Conclusions: The developed phantom has been shown to have no considerable negative effect on the homogeneity of the magnetic field. The proposed method yields an appropriate correction of the measured MRI distortion and is able to improve the PET and MRI registration. Furthermore, the method is applicable to whole-body small animal

  7. A method for small-animal PET/CT alignment calibration

    NASA Astrophysics Data System (ADS)

    Pascau, J.; Vaquero, J. J.; Chamorro-Servent, J.; Rodríguez-Ruano, A.; Desco, M.

    2012-06-01

    Small-animal positron-emission tomography/computed tomography (PET/CT) scanners provide anatomical and molecular imaging, which enables the joint visualization and analysis of both types of data. A proper alignment calibration procedure is essential for small-animal imaging since resolution is much higher than that in human devices. This work presents an alignment phantom and two different calibration methods that provide a reliable and repeatable measurement of the spatial geometrical alignment between the PET and the CT subsystems of a hybrid scanner. The phantom can be built using laboratory materials, and it is meant to estimate the rigid spatial transformation that aligns both modalities. It consists of three glass capillaries filled with a positron-emitter solution and positioned in a non-coplanar triangular geometry inside the system field of view. The calibration methods proposed are both based on automatic line detection, but with different approaches to calculate the transformation of the lines between both modalities. Our results show an average accuracy of the alignment estimation of 0.39 mm over the whole field of view.

  8. Scanner-Dependent Threshold Estimation of Wavelet Denoising for Small-Animal PET

    NASA Astrophysics Data System (ADS)

    Zhao, Jie; Lee, Jhih-Shian; Xu, Hang; Xu, Kai; Ren, Zi-Hui; Chen, Jyh-Cheng; Wu, Cheng-Han

    2017-01-01

    Reducing the noise associated with small-animal positron emission tomography (PET) images is an important and challenging task. Recently, several hybrid denoising techniques based on wavelet transform (WT) have been developed. However, these hybrid methods have complicated mathematical structures and require complex parameter estimations, and they therefore require a high level of manual intervention. Under such circumstances, good performance with respect to image quality using these new methods would only seem to be achievable with an increased computational burden. In this paper, we propose a novel wavelet denoising (WD) method. This method is based on scanner-dependent threshold estimation and the Visushrink method. The method provides a compromise between computational burden and image quality. The experimental results indicate that the proposed method is better than the Visushrink method. Compared with the Visushrink method, the proposed method provides good image quality at higher decomposition levels. In terms of usability and efficiency, the proposed method is better than the hybrid method. The proposed WD method also has several useful properties; therefore, it is possible that it might become an alternative solution to reducing the noise associated with small-animal PET images.

  9. Evaluation of Matrix9 silicon photomultiplier array for small-animal PET.

    PubMed

    Du, Junwei; Schmall, Jeffrey P; Yang, Yongfeng; Di, Kun; Roncali, Emilie; Mitchell, Gregory S; Buckley, Steve; Jackson, Carl; Cherry, Simon R

    2015-02-01

    The MatrixSL-9-30035-OEM (Matrix9) from SensL is a large-area silicon photomultiplier (SiPM) photodetector module consisting of a 3 × 3 array of 4 × 4 element SiPM arrays (total of 144 SiPM pixels) and incorporates SensL's front-end electronics board and coincidence board. Each SiPM pixel measures 3.16 × 3.16 mm(2) and the total size of the detector head is 47.8 × 46.3 mm(2). Using 8 × 8 polished LSO/LYSO arrays (pitch 1.5 mm) the performance of this detector system (SiPM array and readout electronics) was evaluated with a view for its eventual use in small-animal positron emission tomography (PET). Measurements of noise, signal, signal-to-noise ratio, energy resolution, flood histogram quality, timing resolution, and array trigger error were obtained at different bias voltages (28.0-32.5 V in 0.5 V intervals) and at different temperatures (5 °C-25 °C in 5 °C degree steps) to find the optimal operating conditions. The best measured signal-to-noise ratio and flood histogram quality for 511 keV gamma photons were obtained at a bias voltage of 30.0 V and a temperature of 5 °C. The energy resolution and timing resolution under these conditions were 14.2% ± 0.1% and 4.2 ± 0.1 ns, respectively. The flood histograms show that all the crystals in the 1.5 mm pitch LSO array can be clearly identified and that smaller crystal pitches can also be resolved. Flood histogram quality was also calculated using different center of gravity based positioning algorithms. Improved and more robust results were achieved using the local 9 pixels for positioning along with an energy offset calibration. To evaluate the front-end detector readout, and multiplexing efficiency, an array trigger error metric is introduced and measured at different lower energy thresholds. Using a lower energy threshold greater than 150 keV effectively eliminates any mispositioning between SiPM arrays. In summary, the Matrix9 detector system can resolve high-resolution scintillator arrays

  10. Evaluation of Matrix9 silicon photomultiplier array for small-animal PET

    PubMed Central

    Du, Junwei; Schmall, Jeffrey P.; Yang, Yongfeng; Di, Kun; Roncali, Emilie; Mitchell, Gregory S.; Buckley, Steve; Jackson, Carl; Cherry, Simon R.

    2015-01-01

    Purpose: The MatrixSL-9-30035-OEM (Matrix9) from SensL is a large-area silicon photomultiplier (SiPM) photodetector module consisting of a 3 × 3 array of 4 × 4 element SiPM arrays (total of 144 SiPM pixels) and incorporates SensL’s front-end electronics board and coincidence board. Each SiPM pixel measures 3.16 × 3.16 mm2 and the total size of the detector head is 47.8 × 46.3 mm2. Using 8 × 8 polished LSO/LYSO arrays (pitch 1.5 mm) the performance of this detector system (SiPM array and readout electronics) was evaluated with a view for its eventual use in small-animal positron emission tomography (PET). Methods: Measurements of noise, signal, signal-to-noise ratio, energy resolution, flood histogram quality, timing resolution, and array trigger error were obtained at different bias voltages (28.0–32.5 V in 0.5 V intervals) and at different temperatures (5 °C–25 °C in 5 °C degree steps) to find the optimal operating conditions. Results: The best measured signal-to-noise ratio and flood histogram quality for 511 keV gamma photons were obtained at a bias voltage of 30.0 V and a temperature of 5 °C. The energy resolution and timing resolution under these conditions were 14.2% ± 0.1% and 4.2 ± 0.1 ns, respectively. The flood histograms show that all the crystals in the 1.5 mm pitch LSO array can be clearly identified and that smaller crystal pitches can also be resolved. Flood histogram quality was also calculated using different center of gravity based positioning algorithms. Improved and more robust results were achieved using the local 9 pixels for positioning along with an energy offset calibration. To evaluate the front-end detector readout, and multiplexing efficiency, an array trigger error metric is introduced and measured at different lower energy thresholds. Using a lower energy threshold greater than 150 keV effectively eliminates any mispositioning between SiPM arrays. Conclusions: In summary, the Matrix9 detector system can resolve

  11. Micro insert: a prototype full-ring PET device for improving the image resolution of a small-animal PET scanner.

    PubMed

    Wu, Heyu; Pal, Debashish; Song, Tae Yong; O'Sullivan, Joseph A; Tai, Yuan-Chuan

    2008-10-01

    A full-ring PET insert device should be able to enhance the image resolution of existing small-animal PET scanners. The device consists of 18 high-resolution PET detectors in a cylindric enclosure. Each detector contains a cerium-doped lutetium oxyorthosilicate array (12 x 12 crystals, 0.72 x 1.51 x 3.75 mm each) coupled to a position-sensitive photomultiplier tube via an optical fiber bundle made of 8 x 16 square multiclad fibers. Signals from the insert detectors are connected to the scanner through the electronics of the disabled first ring of detectors, which permits coincidence detection between the 2 systems. Energy resolution of a detector was measured using a (68)Ge point source, and a calibrated (68)Ge point source stepped across the axial field of view (FOV) provided the sensitivity profile of the system. A (22)Na point source imaged at different offsets from the center characterized the in-plane resolution of the insert system. Imaging was then performed with a Derenzo phantom filled with 19.5 MBq of (18)F-fluoride and imaged for 2 h; a 24.3-g mouse injected with 129.5 MBq of (18)F-fluoride and imaged in 5 bed positions at 3.5 h after injection; and a 22.8-g mouse injected with 14.3 MBq of (18)F-FDG and imaged for 2 h with electrocardiogram gating. The energy resolution of a typical detector module at 511 keV is 19.0% +/- 3.1%. The peak sensitivity of the system is approximately 2.67%. The image resolution of the system ranges from 1.0- to 1.8-mm full width at half maximum near the center of the FOV, depending on the type of coincidence events used for image reconstruction. Derenzo phantom and mouse bone images showed significant improvement in transaxial image resolution using the insert device. Mouse heart images demonstrated the gated imaging capability of the device. We have built a prototype full-ring insert device for a small-animal PET scanner to provide higher-resolution PET images within a reduced imaging FOV. Development of additional

  12. Appropriateness criteria of FDG PET/CT in oncology

    PubMed Central

    Agrawal, Archi; Rangarajan, Venkatesh

    2015-01-01

    18Fluorine-2-fluoro-2-Deoxy-d-glucose (18F-FDG) positron emission tomography/computerized tomography (PET/CT) is a well-established functional imaging method widely used in oncology. In this article, we have incorporated the various indications for 18FDG PET/CT in oncology based on available evidence and current guidelines. Growing body of evidence for use of 18FDG PET/CT in select tumors is also discussed. This article attempts to give the reader an overview of the appropriateness of using 18F-FDG PET/CT in various malignancies. PMID:25969632

  13. Molecular Imaging in Atherosclerosis: FDG PET

    PubMed Central

    Millon, Antoine

    2013-01-01

    18F-FDG PET is a new noninvasive tool for inflammation functional imaging. Low spatial resolution is now compensated by coregistration with CT or MRI. New mechanistic insights have emerged from animal and histology to explain the obtained signals by hypoxia, macrophage infiltration, and differentiation. Mixed results have been found in biomarkers studies. Interesting data have come recently linking plaque anatomy and function in carotids and in aortic aneurysms as well as inflammation and events. In coronary arteries, plaque assessment is still hampered by myocardium uptake but developments are being made. 18-FDG PET has been able to monitor inflammation before and after several therapies in animals and humans but to date the lack of standardization and the absence of prospective event-driven studies prevent this promising technique to be used in clinical practice. PMID:22872371

  14. 18F-FDG PET/CT in Bladder Cancer.

    PubMed

    Tagliabue, Luca; Russo, Giovanna; Lucignani, Giovanni

    2016-12-01

    Urinary clearance of F-FDG and variability in bladder wall FDG uptake may hamper the interpretation and limit the use of FDG-PET/CT for imaging bladder tumors. Nevertheless, careful combined evaluation of both CT and FDG-PET images of the urinary tract can provide useful findings. We present 2 cases of bladder cancer detected by FDG-PET/CT. These cases suggest that FDG uptake can be indicative of malignancy in bladder cancer when viewed in conjunction with CT scans and that whole-body FDG-PET/CT scans should always be reviewed with particular attention to the urinary tract because abnormalities suggestive of bladder cancer can be found unexpectedly.

  15. TandemPET-A High Resolution, Small Animal, Virtual Pinhole-Based PET Scanner: Initial Design Study

    NASA Astrophysics Data System (ADS)

    Raylman, Raymond R.; Stolin, Alexander V.; Martone, Peter F.; Smith, Mark F.

    2016-02-01

    Mice are the perhaps the most common species of rodents used in biomedical research, but many of the current generation of small animal PET scanners are non-optimal for imaging these small rodents due to their relatively low resolution. Consequently, a number of researchers have investigated the development of high-resolution scanners to address this need. In this investigation, the design of a novel, high-resolution system based on the dual-detector, virtual-pinhole PET concept was explored via Monte Carlo simulations. Specifically, this system, called TandemPET, consists of a 5 cm × 5 cm high-resolution detector made-up of a 90 × 90 array of 0.5 mm × 0.5 × 10 mm (pitch = 0.55 mm) LYSO detector elements in coincidence with a lower resolution detector consisting of a 68 × 68 array of 1.5 mm × 1.5 mm × 10 mm LYSO detector elements (total size = 10.5 cm × 10.5 cm). Analyses indicated that TandemPET's optimal geometry is to position the high-resolution detector 3 cm from the center-of-rotation, with the lower resolution detector positioned 9 cm from center. Measurements using modified NEMA NU4-2008-based protocols revealed that the spatial resolution of the system is 0.5 mm FWHM, after correction of positron range effects. Peak sensitivity is 2.1%, which is comparable to current small animal PET scanners. Images from a digital mouse brain phantom demonstrated the potential of the system for identifying important neurological structures.

  16. Assessment of myocardial metabolic rate of glucose by means of Bayesian ICA and Markov Chain Monte Carlo methods in small animal PET imaging

    NASA Astrophysics Data System (ADS)

    Berradja, Khadidja; Boughanmi, Nabil

    2016-09-01

    In dynamic cardiac PET FDG studies the assessment of myocardial metabolic rate of glucose (MMRG) requires the knowledge of the blood input function (IF). IF can be obtained by manual or automatic blood sampling and cross calibrated with PET. These procedures are cumbersome, invasive and generate uncertainties. The IF is contaminated by spillover of radioactivity from the adjacent myocardium and this could cause important error in the estimated MMRG. In this study, we show that the IF can be extracted from the images in a rat heart study with 18F-fluorodeoxyglucose (18F-FDG) by means of Independent Component Analysis (ICA) based on Bayesian theory and Markov Chain Monte Carlo (MCMC) sampling method (BICA). Images of the heart from rats were acquired with the Sherbrooke small animal PET scanner. A region of interest (ROI) was drawn around the rat image and decomposed into blood and tissue using BICA. The Statistical study showed that there is a significant difference (p < 0.05) between MMRG obtained with IF extracted by BICA with respect to IF extracted from measured images corrupted with spillover.

  17. A detector head design for small-animal PET with silicon photomultipliers (SiPM).

    PubMed

    Moehrs, Sascha; Del Guerra, Alberto; Herbert, Deborah J; Mandelkern, Mark A

    2006-03-07

    Small-animal PET systems are now striving for sub-millimetre resolution. Current systems based upon PSPMTs and finely pixellated scintillators can be pushed to higher resolution, but at the expense of other performance parameters and a rapidly escalating cost. Moreover, depth of interaction (DOI) information is usually difficult to assess in such systems, even though this information is highly desirable to reduce the parallax error, which is often the dominant error for such high-resolution systems. In this study we propose a high-resolution detector head for a small-animal PET imaging system with intrinsic DOI information. Instead of a pixellated scintillator, our design is based upon the classic Anger camera principle, i.e. the head is constructed of modular layers each consisting of a continuous slab of scintillator, viewed by a new type of compact silicon photodetector. The photodetector is the recently developed silicon photomultiplier (SiPM) that as well as being very compact has many other attractive properties: high gain at low bias voltage, excellent single-photoelectron resolution and fast timing. A detector head of about 4 x 4 cm2 in area is proposed, constructed from three modular layers of the type described above. We perform a simulation study, using the Monte Carlo simulation package Geant4. The simulation results are used to optimize the geometry of the detector head and characterize its performance. Additionally, hit estimation algorithms are studied to determine the interaction position of annihilation photons correctly over the whole detector surface. The resulting detector has a nearly uniform efficiency for 511 keV photons of approximately 70% and an intrinsic spatial resolution of less than approximately 0.4 mm full width at half maximum (fwhm).

  18. Characterization of a Small Animal PET Detector Block Incorporating a Digital Photon Counter Array

    NASA Astrophysics Data System (ADS)

    Stortz, Greg; Thompson, Christopher J.; Retière, Fabrice; Goertzen, Andrew L.; Kozlowski, Piotr; Shams, Ehsan; Thiessen, Jonathan D.; Walker, Matthew D.; Sossi, Vesna

    2015-06-01

    A Small Animal PET detector block made with a Dual Layer Offset crystal array with 1.27 mm wide LYSO crystals on a Philips PDC3200-22-44 Digital Photon Counter (DPC) array was characterized while operating near room temperature. Crystal map peak to valley ratio, energy resolution, and timing resolution were characterized as a function of various device settings of the DPC and temperature. In addition, rates of count loss due to the phenomena of incomplete neighbor logic and dark-readout deadtime were measured. Device settings of interest were: Trigger scheme-defining the threshold of when a DPC will generate a timestamp and enter a readout cycle, inhibit fraction-the fraction of noisy cells which are disabled, and RTL-refresh-a setting which reduces the probability of the DPC being triggered from dark noise. At 15°C, peak to valley ratios were measured to be around 11, and energy resolution around 11.5% regardless of device settings. Timing resolution ranged from near 300 ps to 1.5 ns. Count loss from dark readout deadtime was insignificant compared to incomplete neighbor logic, which ranged from as high as 95% to 5% of coincidences. It was found that trade-offs had to be made between timing resolution and count loss. With the most optimal device settings for small animal PET, a timing resolution of 1.4 ns and coincidence losses of 5% were achieved. At these settings, the detector block had little sensitivity to a 5°C temperature fluctuation.

  19. Development of small-animal PET prototype using silicon photomultiplier (SiPM): initial results of phantom and animal imaging studies.

    PubMed

    Kwon, Sun Il; Lee, Jae Sung; Yoon, Hyun Suk; Ito, Mikiko; Ko, Guen Bae; Choi, Jae Yeon; Lee, Sung-Hyuk; Chan Song, In; Jeong, Jae Min; Lee, Dong Soo; Hong, Seong Jong

    2011-04-01

    Silicon photomultiplier (SiPM; also called a Geiger-mode avalanche photodiode) is a promising semiconductor photosensor in PET and PET/MRI because it is intrinsically MRI-compatible and has internal gain and timing properties comparable to those of a photomultiplier tube. In this study, we have developed a small-animal PET system using SiPMs and lutetium gadolinium oxyorthosilicate (LGSO) crystals and performed physical evaluation and animal imaging studies to show the feasibility of this system. The SiPM PET system consists of 8 detectors, each of which comprises 2 × 6 SiPMs and 4 × 13 LGSO crystals. Each crystal has dimensions of 1.5 × 1.5 × 7 mm. The crystal face-to-face diameter and axial field of view are 6.0 cm and 6.5 mm, respectively. Bias voltage is applied to each SiPM using a finely controlled voltage supply because the gain of the SiPM strongly depends on the supply voltage. The physical characteristics were studied by measuring energy resolution, sensitivity, and spatial resolution. Various mouse and rat images were obtained to study the feasibility of the SiPM PET system in in vivo animal studies. Reconstructed PET images using a maximum-likelihood expectation maximization algorithm were coregistered with animal CT images. All individual LGSO crystals within the detectors were clearly distinguishable in flood images obtained by irradiating the detector using a (22)Na point source. The energy resolution for individual crystals was 25.8% ± 2.6% on average for 511-keV photopeaks. The spatial resolution measured with the (22)Na point source in a warm background was 1.0 mm (2 mm off-center) and 1.4 mm (16 mm off-center) when the maximum-likelihood expectation maximization algorithm was applied. A myocardial (18)F-FDG study in mice and a skeletal (18)F study in rats demonstrated the fine spatial resolution of the scanner. The feasibility of the SiPM PET system was also confirmed in the tumor images of mice using (18)F-FDG and (68)Ga-RGD and in the

  20. TandemPET- A High Resolution, Small Animal, Virtual Pinhole-Based PET Scanner: Initial Design Study

    PubMed Central

    Raylman, Raymond R.; Stolin, Alexander V.; Martone, Peter F.; Smith, Mark F.

    2016-01-01

    Mice are the perhaps the most common species of rodents used in biomedical research, but many of the current generation of small animal PET scanners are non-optimal for imaging these small rodents due to their relatively low resolution. Consequently, a number of researchers have investigated the development of high-resolution scanners to address this need. In this investigation, the design of a novel, high-resolution system based on the dual-detector, virtual-pinhole PET concept was explored via Monte Carlo simulations. Specifically, this system, called TandemPET, consists of a 5 cm × 5 cm high-resolution detector made-up of a 90 × 90 array of 0.5 mm × 0.5 mm × 10 mm (pitch= 0.55 mm) LYSO detector elements in coincidence with a lower resolution detector consisting of a 68 × 68 array of 1.5 mm × 1.5 mm × 10 mm LYSO detector elements (total size= 10.5 cm × 10.5 cm). Analyses indicated that TandemPET’s optimal geometry is to position the high-resolution detector 3 cm from the center-of-rotation, with the lower resolution detector positioned 9 cm from center. Measurements using modified NEMA NU4-2008-based protocols revealed that the spatial resolution of the system is ~0.5 mm FWHM, after correction of positron range effects. Peak sensitivity is 2.1%, which is comparable to current small animal PET scanners. Images from a digital mouse brain phantom demonstrated the potential of the system for identifying important neurological structures. PMID:27041767

  1. Denoising of high resolution small animal 3D PET data using the non-subsampled Haar wavelet transform

    NASA Astrophysics Data System (ADS)

    Ochoa Domínguez, Humberto de Jesús; Máynez, Leticia O.; Vergara Villegas, Osslan O.; Mederos, Boris; Mejía, José M.; Cruz Sánchez, Vianey G.

    2015-06-01

    PET allows functional imaging of the living tissue. However, one of the most serious technical problems affecting the reconstructed data is the noise, particularly in images of small animals. In this paper, a method for high-resolution small animal 3D PET data is proposed with the aim to reduce the noise and preserve details. The method is based on the estimation of the non-subsampled Haar wavelet coefficients by using a linear estimator. The procedure is applied to the volumetric images, reconstructed without correction factors (plane reconstruction). Results show that the method preserves the structures and drastically reduces the noise that contaminates the image.

  2. FDG-PET/CT in lymphoma

    PubMed Central

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

    2013-01-01

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

  3. Evaluation of Matrix9 silicon photomultiplier array for small-animal PET

    SciTech Connect

    Du, Junwei Schmall, Jeffrey P.; Yang, Yongfeng; Di, Kun; Roncali, Emilie; Mitchell, Gregory S.; Buckley, Steve; Jackson, Carl; Cherry, Simon R.

    2015-02-15

    Purpose: The MatrixSL-9-30035-OEM (Matrix9) from SensL is a large-area silicon photomultiplier (SiPM) photodetector module consisting of a 3 × 3 array of 4 × 4 element SiPM arrays (total of 144 SiPM pixels) and incorporates SensL’s front-end electronics board and coincidence board. Each SiPM pixel measures 3.16 × 3.16 mm{sup 2} and the total size of the detector head is 47.8 × 46.3 mm{sup 2}. Using 8 × 8 polished LSO/LYSO arrays (pitch 1.5 mm) the performance of this detector system (SiPM array and readout electronics) was evaluated with a view for its eventual use in small-animal positron emission tomography (PET). Methods: Measurements of noise, signal, signal-to-noise ratio, energy resolution, flood histogram quality, timing resolution, and array trigger error were obtained at different bias voltages (28.0–32.5 V in 0.5 V intervals) and at different temperatures (5 °C–25 °C in 5 °C degree steps) to find the optimal operating conditions. Results: The best measured signal-to-noise ratio and flood histogram quality for 511 keV gamma photons were obtained at a bias voltage of 30.0 V and a temperature of 5 °C. The energy resolution and timing resolution under these conditions were 14.2% ± 0.1% and 4.2 ± 0.1 ns, respectively. The flood histograms show that all the crystals in the 1.5 mm pitch LSO array can be clearly identified and that smaller crystal pitches can also be resolved. Flood histogram quality was also calculated using different center of gravity based positioning algorithms. Improved and more robust results were achieved using the local 9 pixels for positioning along with an energy offset calibration. To evaluate the front-end detector readout, and multiplexing efficiency, an array trigger error metric is introduced and measured at different lower energy thresholds. Using a lower energy threshold greater than 150 keV effectively eliminates any mispositioning between SiPM arrays. Conclusions: In summary, the Matrix9 detector system

  4. Contrast-enhanced small-animal PET/CT in cancer research: strong improvement of diagnostic accuracy without significant alteration of quantitative accuracy and NEMA NU 4–2008 image quality parameters

    PubMed Central

    2013-01-01

    Background The use of iodinated contrast media in small-animal positron emission tomography (PET)/computed tomography (CT) could improve anatomic referencing and tumor delineation but may introduce inaccuracies in the attenuation correction of the PET images. This study evaluated the diagnostic performance and accuracy of quantitative values in contrast-enhanced small-animal PET/CT (CEPET/CT) as compared to unenhanced small animal PET/CT (UEPET/CT). Methods Firstly, a NEMA NU 4–2008 phantom (filled with 18F-FDG or 18F-FDG plus contrast media) and a homemade phantom, mimicking an abdominal tumor surrounded by water or contrast media, were used to evaluate the impact of iodinated contrast media on the image quality parameters and accuracy of quantitative values for a pertinent-sized target. Secondly, two studies in 22 abdominal tumor-bearing mice and rats were performed. The first animal experiment studied the impact of a dual-contrast media protocol, comprising the intravenous injection of a long-lasting contrast agent mixed with 18F-FDG and the intraperitoneal injection of contrast media, on tumor delineation and the accuracy of quantitative values. The second animal experiment compared the diagnostic performance and quantitative values of CEPET/CT versus UEPET/CT by sacrificing the animals after the tracer uptake period and imaging them before and after intraperitoneal injection of contrast media. Results There was minimal impact on IQ parameters (%SDunif and spillover ratios in air and water) when the NEMA NU 4–2008 phantom was filled with 18F-FDG plus contrast media. In the homemade phantom, measured activity was similar to true activity (−0.02%) and overestimated by 10.30% when vials were surrounded by water or by an iodine solution, respectively. The first animal experiment showed excellent tumor delineation and a good correlation between small-animal (SA)-PET and ex vivo quantification (r2 = 0.87, P < 0.0001). The second animal experiment showed a good

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

    NASA Astrophysics Data System (ADS)

    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. DigiPET: sub-millimeter spatial resolution small-animal PET imaging using thin monolithic scintillators

    NASA Astrophysics Data System (ADS)

    España, Samuel; Marcinkowski, Radoslaw; Keereman, Vincent; Vandenberghe, Stefaan; Van Holen, Roel

    2014-07-01

    A new preclinical PET system based on dSiPMs, called DigiPET, is presented. The system is based on thin monolithic scintillation crystals and exhibits superior spatial resolution at low-cost compared to systems based on pixelated crystals. Current dedicated small-rodent PET scanners have a spatial resolution in the order of 1 mm. Most of them have a large footprint, requiring considerable laboratory space. For rodent brain imaging, a PET scanner with sub-millimeter resolution is desired. To achieve this, crystals with a pixel pitch down to 0.5 mm have been used. However, fine pixels are difficult to produce and will render systems expensive. In this work, we present the first results with a high-resolution preclinical PET scanner based on thin monolithic scintillators and a large solid angle. The design is dedicated to rat-brain imaging and therefore has a very compact geometry. Four detectors were placed in a square arrangement with a distance of 34.5 mm between two opposing detector modules, defining a field of view (FOV) of 32 × 32 × 32 mm3. Each detector consists of a thin monolithic LYSO crystal of 32 × 32 × 2 mm3 optically coupled to a digital silicon photomultiplier (dSiPM). Event positioning within each detector was obtained using the maximum likelihood estimation (MLE) method. To evaluate the system performance, we measured the energy resolution, coincidence resolving time (CRT), sensitivity and spatial resolution. The image quality was evaluated by acquiring a hot-rod phantom filled with 18F-FDG and a rat head one hour after an 18F-FDG injection. The MLE yielded an average intrinsic spatial resolution on the detector of 0.54 mm FWHM. We obtained a CRT of 680 ps and an energy resolution of 18% FWHM at 511 keV. The sensitivity and spatial resolution obtained at the center of the FOV were 6.0 cps kBq-1 and 0.7 mm, respectively. In the reconstructed images of the hot-rod phantom, hot rods down to 0.7 mm can be discriminated. In conclusion, a compact PET

  7. Validation of a small-animal PET simulation using GAMOS: a GEANT4-based framework

    NASA Astrophysics Data System (ADS)

    Cañadas, M.; Arce, P.; Rato Mendes, P.

    2011-01-01

    Monte Carlo-based modelling is a powerful tool to help in the design and optimization of positron emission tomography (PET) systems. The performance of these systems depends on several parameters, such as detector physical characteristics, shielding or electronics, whose effects can be studied on the basis of realistic simulated data. The aim of this paper is to validate a comprehensive study of the Raytest ClearPET small-animal PET scanner using a new Monte Carlo simulation platform which has been developed at CIEMAT (Madrid, Spain), called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations). This toolkit, based on the GEANT4 code, was originally designed to cover multiple applications in the field of medical physics from radiotherapy to nuclear medicine, but has since been applied by some of its users in other fields of physics, such as neutron shielding, space physics, high energy physics, etc. Our simulation model includes the relevant characteristics of the ClearPET system, namely, the double layer of scintillator crystals in phoswich configuration, the rotating gantry, the presence of intrinsic radioactivity in the crystals or the storage of single events for an off-line coincidence sorting. Simulated results are contrasted with experimental acquisitions including studies of spatial resolution, sensitivity, scatter fraction and count rates in accordance with the National Electrical Manufacturers Association (NEMA) NU 4-2008 protocol. Spatial resolution results showed a discrepancy between simulated and measured values equal to 8.4% (with a maximum FWHM difference over all measurement directions of 0.5 mm). Sensitivity results differ less than 1% for a 250-750 keV energy window. Simulated and measured count rates agree well within a wide range of activities, including under electronic saturation of the system (the measured peak of total coincidences, for the mouse-sized phantom, was 250.8 kcps reached at 0.95 MBq mL-1 and the simulated peak was

  8. Clinical application of FDG-PET/CT in metastatic infections.

    PubMed

    Kouijzer, Ilse J; Vos, Fidel J; Bleeker-Rovers, Chantal P; Oyen, Wim J

    2017-06-01

    FDG-PET/CT has proven its clinical value and cost-effectiveness in diagnosing metastatic infections in patients with Gram-positive bacteremia. In identification of metastatic foci, FDG-PET/CT is useful as a screening method when localizing symptoms are absent because it provides whole-body coverage. FDG-PET/CT detects early metabolic activity rather than the late anatomical changes as visualized by computed tomography and magnetic resonance imaging. FDG-PET/CT allows more precise localization of infection within a shorter time span between injection and diagnosis as compared to conventional nuclear imaging. This review focuses on the clinical application of imaging of metastatic infectious diseases, with an emphasis on FDG-PET/CT putting it in perspective with other imaging modalities.

  9. FDG PET Appearance of "Cannonball" Pulmonary Metastases.

    PubMed

    Meka, Murali; Bommireddipalli, Srinivas; Killam, Jonathan; Bhargava, Peeyush; Depuey, E Gordon

    2009-01-01

    We present the case of a 67-year-old woman with a recent tissue diagnosis of endometrial cancer whose FDG PET scan exhibited multiple hypermetabolic foci through out both the lungs. Contemporaneously acquired conventional radiolographs showed parenchymal nodules that demonstrated the classic "cannon ball" appearance of pulmonary metastases. Pulmonary metastasis from an endometrial primary is a rare event, as are the presence of pulmonary findings at the time of initial staging. Thus, this case demonstrates rare, and yet, distinctive aspects of the disease presentation and image correlation across the various imaging modalities.

  10. NEMA NU 2-2007 performance measurements of the Siemens Inveon™ preclinical small animal PET system

    NASA Astrophysics Data System (ADS)

    Kemp, Brad J.; Hruska, Carrie B.; McFarland, Aaron R.; Lenox, Mark W.; Lowe, Val J.

    2009-04-01

    National Electrical Manufacturers Association (NEMA) NU 2-2007 performance measurements were conducted on the Inveon™ preclinical small animal PET system developed by Siemens Medical Solutions. The scanner uses 1.51 × 1.51 × 10 mm LSO crystals grouped in 20 × 20 blocks; a tapered light guide couples the LSO crystals of a block to a position-sensitive photomultiplier tube. There are 80 rings with 320 crystals per ring and the ring diameter is 161 mm. The transaxial and axial fields of view (FOVs) are 100 and 127 mm, respectively. The scanner can be docked to a CT scanner; the performance characteristics of the CT component are not included herein. Performance measurements of spatial resolution, sensitivity, scatter fraction and count rate performance were obtained for different energy windows and coincidence timing window widths. For brevity, the results described here are for an energy window of 350-650 keV and a coincidence timing window of 3.43 ns. The spatial resolution at the center of the transaxial and axial FOVs was 1.56, 1.62 and 2.12 mm in the tangential, radial and axial directions, respectively, and the system sensitivity was 36.2 cps kBq-1 for a line source (7.2% for a point source). For mouse- and rat-sized phantoms, the scatter fraction was 5.7% and 14.6%, respectively. The peak noise equivalent count rate with a noisy randoms estimate was 1475 kcps at 130 MBq for the mouse-sized phantom and 583 kcps at 74 MBq for the rat-sized phantom. The performance measurements indicate that the Inveon™ PET scanner is a high-resolution tomograph with excellent sensitivity that is capable of imaging at a high count rate.

  11. NEMA NU 2-2007 performance measurements of the Siemens Inveon preclinical small animal PET system.

    PubMed

    Kemp, Brad J; Hruska, Carrie B; McFarland, Aaron R; Lenox, Mark W; Lowe, Val J

    2009-04-21

    National Electrical Manufacturers Association (NEMA) NU 2-2007 performance measurements were conducted on the Inveon preclinical small animal PET system developed by Siemens Medical Solutions. The scanner uses 1.51 x 1.51 x 10 mm LSO crystals grouped in 20 x 20 blocks; a tapered light guide couples the LSO crystals of a block to a position-sensitive photomultiplier tube. There are 80 rings with 320 crystals per ring and the ring diameter is 161 mm. The transaxial and axial fields of view (FOVs) are 100 and 127 mm, respectively. The scanner can be docked to a CT scanner; the performance characteristics of the CT component are not included herein. Performance measurements of spatial resolution, sensitivity, scatter fraction and count rate performance were obtained for different energy windows and coincidence timing window widths. For brevity, the results described here are for an energy window of 350-650 keV and a coincidence timing window of 3.43 ns. The spatial resolution at the center of the transaxial and axial FOVs was 1.56, 1.62 and 2.12 mm in the tangential, radial and axial directions, respectively, and the system sensitivity was 36.2 cps kBq(-1) for a line source (7.2% for a point source). For mouse- and rat-sized phantoms, the scatter fraction was 5.7% and 14.6%, respectively. The peak noise equivalent count rate with a noisy randoms estimate was 1475 kcps at 130 MBq for the mouse-sized phantom and 583 kcps at 74 MBq for the rat-sized phantom. The performance measurements indicate that the Inveon PET scanner is a high-resolution tomograph with excellent sensitivity that is capable of imaging at a high count rate.

  12. The effect of β + energy on performance of a small animal PET camera

    NASA Astrophysics Data System (ADS)

    Partridge, M.; Spinelli, A.; Ryder, W.; Hindorf, C.

    2006-12-01

    The effective spatial resolution of a positron emission tomography (PET) scanner is determined in part by the initial energy of the positron, which is a function of the radionuclide. For F-18 ( Emax=0.633 MeV) the mean positron range in water is small (0.6 mm). However, many other useful positron-emitting nuclides have higher energies, for example Ga-68 ( Emax=1.899 MeV, mean range 2.9 mm) has one of the highest. The performance of a non-rotating, 16 module high density avalanche chamber (quad-HIDAC) small animal PET scanner was measured using both F-18 and Ga-68 to represent the extremes of high and low positron energy. The count rate performance—scatter fraction and noise-equivalent count rate (NEC)—were measured for both isotopes. Data were also collected for a spatial resolution phantom with rectangular arrays of holes of diameter 2.0, 1.5, 1.0 and 0.5 mm with the centres separated by 4.0, 3.0, 2.0 and 1.0 mm respectively. The NEC, measured for both 70 and 200 cm 3 cylindrical phantoms, was approximately linear up to 30 MBq, but shows a rapid drop-off above this value. The spatial resolution phantom showed that 1 mm objects are just resolved with F-18, but none of the targets are resolved for Ga-68. In conclusion, spatial resolution is dominated by the choice of isotope down to 1 mm, with sensitivity and count-rate data being largely independent of positron range.

  13. NEMA NU 2-2007 performance measurements of the Siemens Inveon™ preclinical small animal PET system

    PubMed Central

    Kemp, Brad J; Hruska, Carrie B; McFarland, Aaron R; Lenox, Mark W; Lowe, Val J

    2010-01-01

    National Electrical Manufacturers Association (NEMA) NU 2-2007 performance measurements were conducted on the Inveon™ preclinical small animal PET system developed by Siemens Medical Solutions. The scanner uses 1.51 × 1.51 × 10 mm LSO crystals grouped in 20 × 20 blocks; a tapered light guide couples the LSO crystals of a block to a position-sensitive photomultiplier tube. There are 80 rings with 320 crystals per ring and the ring diameter is 161 mm. The transaxial and axial fields of view (FOVs) are 100 and 127 mm, respectively. The scanner can be docked to a CT scanner; the performance characteristics of the CT component are not included herein. Performance measurements of spatial resolution, sensitivity, scatter fraction and count rate performance were obtained for different energy windows and coincidence timing window widths. For brevity, the results described here are for an energy window of 350–650 keV and a coincidence timing window of 3.43 ns. The spatial resolution at the center of the transaxial and axial FOVs was 1.56, 1.62 and 2.12 mm in the tangential, radial and axial directions, respectively, and the system sensitivity was 36.2 cps kBq−1 for a line source (7.2% for a point source). For mouse- and rat-sized phantoms, the scatter fraction was 5.7% and 14.6%, respectively. The peak noise equivalent count rate with a noisy randoms estimate was 1475 kcps at 130 MBq for the mouse-sized phantom and 583 kcps at 74 MBq for the rat-sized phantom. The performance measurements indicate that the Inveon™ PET scanner is a high-resolution tomograph with excellent sensitivity that is capable of imaging at a high count rate. PMID:19321924

  14. In vivo biodistribution and small animal PET of (64)Cu-labeled antimicrobial peptoids.

    PubMed

    Seo, Jiwon; Ren, Gang; Liu, Hongguang; Miao, Zheng; Park, Minyoung; Wang, Yihong; Miller, Tyler M; Barron, Annelise E; Cheng, Zhen

    2012-05-16

    Peptoids are a rapidly developing class of biomimetic polymers based on oligo-N-substituted glycine backbones, designed to mimic peptides and proteins. Inspired by natural antimicrobial peptides, a group of cationic amphipathic peptoids has been successfully discovered with potent, broad-spectrum activity against pathogenic bacteria; however, there are limited studies to address the in vivo pharmacokinetics of the peptoids. Herein, (64)Cu-labeled DOTA conjugates of three different peptoids and two control peptides were synthesized and assayed in vivo by both biodistribution studies and small animal positron emission tomography (PET). The study was designed in a way to assess how structural differences of the peptidomimetics affect in vivo pharmacokinetics. As amphipathic molecules, major uptake of the peptoids occurred in the liver. Increased kidney uptake was observed by deleting one hydrophobic residue in the peptoid, and (64)Cu-3 achieved the highest kidney uptake of all the conjugates tested in this study. In comparison to peptides, our data indicated that peptoids had general in vivo properties of higher tissue accumulation, slower elimination, and higher in vivo stability. Different administration routes (intravenous, intraperitoneal, and oral) were investigated with peptoids. When administered orally, the peptoids showed poor bioavailability, reminiscent of that of peptide. However, remarkably longer passage through the gastrointestinal (GI) tract without rapid digestion was observed for peptoids. These unique in vivo properties of peptoids were rationalized by efficient cellular membrane permeability and protease resistance of peptoids. The results observed in the biodistribution studies could be confirmed by PET imaging, which provides a reliable way to evaluate in vivo pharmacokinetic properties of peptoids noninvasively and in real time. The pharmacokinetic data presented here can provide insight for further development of the antimicrobial peptoids as

  15. A prototype of very high resolution small animal PET scanner using silicon pad detectors

    PubMed Central

    Park, Sang-June; Leslie Rogers, W.; Huh, Sam; Kagan, Harris; Honscheid, Klaus; Burdette, Don; Chesi, Enrico; Lacasta, Carlos; Llosa, Gabriela; Mikuz, Marko; Studen, Andrej; Weilhammer, Peter; Clinthorne, Neal H.

    2007-01-01

    A very high resolution small animal positron emission tomograph (PET) which can achieve sub-millimeter spatial resolution is being developed using silicon pad detectors. The prototype PET for a single slice instrument consists of two 1 mm thick silicon pad detectors, each containing a 32 × 16 array of 1.4 mm × 1.4 mm pads read out with four VATAGP3 chips which have 128 channels low-noise self triggering ASIC in each chip, coincidence units, a source turntable and tungsten slice collimator. The silicon detectors were located edgewise on opposite sides of a 4 cm field-of-view to maximize efficiency. Energy resolution is dominated by electronic noise, which is 0.98% (1.38 keV) FWHM at 140.5 keV. Coincidence timing resolution is 82.1 ns FWHM and coincidence efficiency was measured to be 1.04 × 10-3 % from two silicon detectors with annihilation photons of 18F source Image data were acquired and reconstructed using conventional 2-D filtered-back projection (FBP) and a maximum likelihood expectation maximization (ML-EM) method. Image resolution of approximately 1.45 mm FWHM is obtained from 1-D profile of 1.1 mm diameter 18F line source image. Even better resolution can be obtained with smaller detector element sizes. While many challenges remain in scaling up the instrument to useful efficiency including densely packed detectors and significantly improved timing resolution, performance of the test setup in terms of easily achieving submillimeter resolution is compelling. PMID:18084629

  16. FDG-PET uptake in occult acute pelvic fracture.

    PubMed

    Ravenel, James G; Gordon, Leonie L; Pope, Thomas L; Reed, Carolyn E

    2004-02-01

    The role of FDG-PET in the diagnosis of bone metastases remains unsettled, although it is hoped that PET scans will add specificity to or replace bone scintigraphy. We report a case in which an acute traumatic fracture presented with a level of uptake generally considered indicative of neoplasm. It is important to recognize that increased FDG-PET activity in bone should not be accepted as definitive evidence of metastatic disease.

  17. Design of a Second Generation Firewire Based Data Acquisition System for Small Animal PET Scanners.

    PubMed

    Lewellen, T K; Miyaoka, R S; Macdonald, L R; Haselman, M; Dewitt, D; Hunter, William; Hauck, S

    2008-10-19

    The University of Washington developed a Firewire based data acquisition system for the MiCES small animal PET scanner. Development work has continued on new imaging scanners that require more data channels and need to be able to operate within a MRI imaging system. To support these scanners, we have designed a new version of our data acquisition system that leverages the capabilities of modern field programmable gate arrays (FPGA). The new design preserves the basic approach of the original system, but puts almost all functions into the FPGA, including the Firewire elements, the embedded processor, and pulse timing and pulse integration. The design has been extended to support implementation of the position estimation and DOl algorithms developed for the cMiCE detector module. The design is centered around an acquisition node board (ANB) that includes 65 ADC channels, Firewire 1394b support, the FPGA, a serial command bus and signal lines to support a rough coincidence window implementation to reject singles events from being sent on the Firewire bus. Adapter boards convert detector signals into differential paired signals to connect to the ANB.

  18. A LSO β microprobe for measuring input functions for quantitative small animal PET

    NASA Astrophysics Data System (ADS)

    Maramraju, S.; Stoll, S.; Woody, C.; Schlyer, D.; Schiffer, W.; Lee, D.; Dewey, S.; Vaska, P.

    2007-02-01

    A miniature scintillation microprobe has been developed to measure the input function in live rodents for use in longitudinal, quantitative PET studies. The probe consists of a small lutetium oxyorthosilicate (LSO) crystal measuring typically 0.3-0.5 mm diameter ×0.5-2 mm in length that is used to directly detect positrons in the blood or tissue. The probe has a sensitivity of 10-30 Hz/μCi/cm 3 and is primarily sensitive to short-range positrons emitted by labeled radiotracers in the blood. The sensitivity to γ-ray background can be minimized using a variable threshold in the readout to discriminate between positrons and γ's. The probe was implanted in one of the tail veins of a Sprague-Dawley rat and the input function was measured for the injection of 0.8 mCi of FDG in the other tail vein. The probe exhibits a fast time response that is able to quickly and accurately measure the concentration of 18F circulating in the bloodstream. Additional tests were also carried out to study the probe's sensitivity to γ-ray background.

  19. A high resolution prototype small-animal PET scanner dedicated to mouse brain imaging

    PubMed Central

    Yang, Yongfeng; Bec, Julien; Zhou, Jian; Zhang, Mengxi; Judenhofer, Martin S; Bai, Xiaowei; Di, Kun; Wu, Yibao; Rodriguez, Mercedes; Dokhale, Purushottam; Shah, Kanai S.; Farrell, Richard; Qi, Jinyi; Cherry, Simon R.

    2017-01-01

    A prototype small-animal PET scanner was developed based on depth-encoding detectors using dual-ended readout of very small scintillator elements to produce high and uniform spatial resolution suitable for imaging the mouse brain. Methods The scanner consists of 16 tapered dual-ended readout detectors arranged in a ring of diameter 61 mm. The axial field of view is 7 mm and the transaxial field of view is 30 mm. The scintillator arrays consist of 14×14 lutetium oxyorthosilicate (LSO) elements, with a crystal size of 0.43×0.43 mm2 at the front end and 0.80×0.43 mm2 at the back end, and the crystal elements are 13 mm long. The arrays are read out by 8×8 mm2 and a 13×8 mm2 position-sensitive avalanche photodiodes (PSAPDs) placed at opposite ends of the array. Standard nuclear instrumentation module (NIM) electronics and a custom designed multiplexer are used for signal processing. Results The detector performance was measured and all except the very edge crystals could be clearly resolved. The average detector intrinsic spatial resolution in the axial direction was 0.61 mm. A depth of interaction resolution of 1.7 mm was achieved. The sensitivity of the scanner at center of the field of view was 1.02% for a lower energy threshold of 150 keV and 0.68% for a lower energy threshold of 250 keV. The spatial resolution within a field of view that can accommodate the entire mouse brain was ~0.6 mm using a 3D Maximum Likelihood-Expectation Maximization (ML-EM) reconstruction algorithm. Images of a micro hot-rod phantom showed that rods with diameter down to 0.5 mm could be resolved. First in vivo studies were obtained using 18F-fluoride and confirmed that 0.6 mm resolution can be achieved in the mouse head in vivo. Brain imaging studies with 18F-fluorodeoxyglucose were also acquired. Conclusion A prototype PET scanner achieving a spatial resolution approaching the physical limits for a small-bore PET scanner set by positron range and acolinearity was developed. Future

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

    PubMed Central

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

    2001-01-01

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

  1. Predictive and prognostic value of FDG-PET

    PubMed Central

    Oyen, Wim J.G.

    2008-01-01

    Abstract The predictive and prognostic value of fluorodeoxyglucose (FDG)-positron emission tomography (PET) in non-small-cell lung carcinoma, colorectal carcinoma and lymphoma is discussed. The degree of FDG uptake is of prognostic value at initial presentation, after induction treatment prior to resection and in the case of relapse of non-small cell lung cancer (NSCLC). In locally advanced and advanced stages of NSCLC, FDG-PET has been shown to be predictive for clinical outcome at an early stage of treatment. In colorectal carcinoma, limited studies are available on the prognostic value of FDG-PET, however, the technique appears to have great potential in monitoring the success of local ablative therapies soon after intervention and in the prediction and evaluation of response to radiotherapy, systemic therapy, and combinations thereof. The prognostic value of end-of treatment FDG-PET for FDG-avid lymphomas has been established, and the next step is to define how to use this information to optimize patient outcome. In Hodgkin's lymphoma, FDG-PET has a high negative predictive value, however, histological confirmation of positive findings should be sought where possible. For non-Hodgkin's lymphoma, the opposite applies. The newly published standardized guidelines for interpretation formulates specific criteria for visual interpretation and for defining PET positivity in the liver, spleen, lung, bone marrow and small residual lesions. The introduction of these guidelines should reduce variability among studies. Interim PET offers a reliable method for early prediction of long-term remission, however it should only be performed in prospective randomized controlled trials. Many of the diagnostic and management questions considered in this review are relevant to other tumour types. Further research in this field is of great importance, since it may lead to a change in the therapeutic concept of cancer. The preliminary findings call for systematic inclusion of FDG-PET

  2. Diffuse hepatic amebiasis detected by FDG PET/CT.

    PubMed

    Zhou, Weiyan; Zhao, Jinhua; Xing, Yan; Chen, Xiang; Song, Jianhua

    2015-02-01

    A 39-year-old man presented with sudden decreased visual acuity in his left eye. Orbital CT and MRI revealed a soft tissue lesion in his left orbital apex. FDG PET/CT showed increased FDG uptake by the left orbital lesion, abnormal focal FDG uptake in the soft tissues of the external ears, and abnormal heterogeneous FDG activity throughout the liver. Percutaneous liver biopsy, external auditory canal discharge, and stool specimens revealed amebiasis. The patient responded to antiamebic therapy, and his lesions improved. The case demonstrates that during its early stage, hepatic amebiasis may be associated with a relatively heterogeneous pattern of FDG uptake.

  3. Post-Surgical Atypical FDG-PET Uptake

    PubMed Central

    Dubroff, Jacob G.; Alavi, Abass; Friedberg, Joseph S.; Cengel, Keith A.

    2011-01-01

    False positive recognition is crucial for proper interpretation of FDG-PET studies. The authors present a case of a woman who underwent surgery over a month prior to PET/CT imaging which revealed significant tracer uptake within muscles and soft tissue in several sites contralateral to the location of surgery. The FDG-PET images of this case illustrate the importance of communication between physicians ordering and physicians reading FDG-PET/CT scans as well as atypical FDG-PET findings that could be interpreted as concerning but are, in fact, innocuous. This study also demonstrates the unusual glucose metabolic patterns which may arise following treatment be it surgical, chemotherapeutic or radiation. PMID:19851183

  4. FDG PET/CT findings in rare sarcomas.

    PubMed

    Ergül, N; Aydın, M

    2013-01-01

    The role of FDG PET/CT in management of soft tissue and bone sarcomas has been described in many studies up-to-date. However, contribution of PET/CT to diagnosis and treatment in some types of sarcomas that are seen with low incidence has not been identified properly yet. Clear cell sarcoma, synovial sarcoma of chest and myxoid lyposarcoma are rare types of sarcomas. We aimed to describe the FDG uptake patterns of these rare tumors and find out the role of FDG PET/CT in management of disease. Copyright © 2012 Elsevier España, S.L. and SEMNIM. All rights reserved.

  5. Small animal simultaneous PET/MRI: initial experiences in a 9.4 T microMRI

    NASA Astrophysics Data System (ADS)

    Harsha Maramraju, Sri; Smith, S. David; Junnarkar, Sachin S.; Schulz, Daniela; Stoll, Sean; Ravindranath, Bosky; Purschke, Martin L.; Rescia, Sergio; Southekal, Sudeepti; Pratte, Jean-François; Vaska, Paul; Woody, Craig L.; Schlyer, David J.

    2011-04-01

    We developed a non-magnetic positron-emission tomography (PET) device based on the rat conscious animal PET that operates in a small-animal magnetic resonance imaging (MRI) scanner, thereby enabling us to carry out simultaneous PET/MRI studies. The PET detector comprises 12 detector blocks, each being a 4 × 8 array of lutetium oxyorthosilicate crystals (2.22 × 2.22 × 5 mm3) coupled to a matching non-magnetic avalanche photodiode array. The detector blocks, housed in a plastic case, form a 38 mm inner diameter ring with an 18 mm axial extent. Custom-built MRI coils fit inside the positron-emission tomography (PET) device, operating in transceiver mode. The PET insert is integrated with a Bruker 9.4 T 210 mm clear-bore diameter MRI scanner. We acquired simultaneous PET/MR images of phantoms, of in vivo rat brain, and of cardiac-gated mouse heart using [11C]raclopride and 2-deoxy-2-[18F]fluoro-d-glucose PET radiotracers. There was minor interference between the PET electronics and the MRI during simultaneous operation, and small effects on the signal-to-noise ratio in the MR images in the presence of the PET, but no noticeable visual artifacts. Gradient echo and high-duty-cycle spin echo radio frequency (RF) pulses resulted in a 7% and a 28% loss in PET counts, respectively, due to high PET counts during the RF pulses that had to be gated out. The calibration of the activity concentration of PET data during MR pulsing is reproducible within less than 6%. Our initial results demonstrate the feasibility of performing simultaneous PET and MRI studies in adult rats and mice using the same PET insert in a small-bore 9.4 T MRI.

  6. Small animal simultaneous PET/MRI: initial experiences in a 9.4T microMRI

    SciTech Connect

    Maramraju, S.H.; Schlyer, D.; Maramraju, S.H.; Smith, S.D.; Junnarkar, S.S.; Schulz, D.; Stoll, S.; Ravindranath, B.; Purschke, M.L.; Rescia, S.; Southekal, S.; Pratte, J.-F.; Vaska, P.; Woody, C.L.; Schlyer, D.J.

    2011-03-25

    We developed a non-magnetic positron-emission tomography (PET) device based on the rat conscious animal PET that operates in a small-animal magnetic resonance imaging (MRI) scanner, thereby enabling us to carry out simultaneous PET/MRI studies. The PET detector comprises 12 detector blocks, each being a 4 x 8 array of lutetium oxyorthosilicate crystals (2.22 x 2.22 x 5 mm{sup 3}) coupled to a matching non-magnetic avalanche photodiode array. The detector blocks, housed in a plastic case, form a 38 mm inner diameter ring with an 18 mm axial extent. Custom-built MRI coils fit inside the positron-emission tomography (PET) device, operating in transceiver mode. The PET insert is integrated with a Bruker 9.4 T 210 mm clear-bore diameter MRI scanner. We acquired simultaneous PET/MR images of phantoms, of in vivo rat brain, and of cardiac-gated mouse heart using [{sup 11}C]raclopride and 2-deoxy-2-[{sup 18}F]fluoro-d-glucose PET radiotracers. There was minor interference between the PET electronics and the MRI during simultaneous operation, and small effects on the signal-to-noise ratio in the MR images in the presence of the PET, but no noticeable visual artifacts. Gradient echo and high-duty-cycle spin echo radio frequency (RF) pulses resulted in a 7% and a 28% loss in PET counts, respectively, due to high PET counts during the RF pulses that had to be gated out. The calibration of the activity concentration of PET data during MR pulsing is reproducible within less than 6%. Our initial results demonstrate the feasibility of performing simultaneous PET and MRI studies in adult rats and mice using the same PET insert in a small-bore 9.4 T MRI.

  7. Attenuation correction for freely moving small animal brain PET studies based on a virtual scanner geometry

    NASA Astrophysics Data System (ADS)

    Angelis, G. I.; Kyme, A. Z.; Ryder, W. J.; Fulton, R. R.; Meikle, S. R.

    2014-10-01

    Attenuation correction in positron emission tomography brain imaging of freely moving animals is a very challenging problem since the torso of the animal is often within the field of view and introduces a non negligible attenuating factor that can degrade the quantitative accuracy of the reconstructed images. In the context of unrestrained small animal imaging, estimation of the attenuation correction factors without the need for a transmission scan is highly desirable. An attractive approach that avoids the need for a transmission scan involves the generation of the hull of the animal’s head based on the reconstructed motion corrected emission images. However, this approach ignores the attenuation introduced by the animal’s torso. In this work, we propose a virtual scanner geometry which moves in synchrony with the animal’s head and discriminates between those events that traversed only the animal’s head (and therefore can be accurately compensated for attenuation) and those that might have also traversed the animal’s torso. For each recorded pose of the animal’s head a new virtual scanner geometry is defined and therefore a new system matrix must be calculated leading to a time-varying system matrix. This new approach was evaluated on phantom data acquired on the microPET Focus 220 scanner using a custom-made phantom and step-wise motion. Results showed that when the animal’s torso is within the FOV and not appropriately accounted for during attenuation correction it can lead to bias of up to 10% . Attenuation correction was more accurate when the virtual scanner was employed leading to improved quantitative estimates (bias < 2%), without the need to account for the attenuation introduced by the extraneous compartment. Although the proposed method requires increased computational resources, it can provide a reliable approach towards quantitatively accurate attenuation correction for freely moving animal studies.

  8. Small-Animal PET Imaging of Tau Pathology with 18F-THK5117 in 2 Transgenic Mouse Models.

    PubMed

    Brendel, Matthias; Jaworska, Anna; Probst, Federico; Overhoff, Felix; Korzhova, Viktoria; Lindner, Simon; Carlsen, Janette; Bartenstein, Peter; Harada, Ryuichi; Kudo, Yukitsuka; Haass, Christian; Van Leuven, Fred; Okamura, Nobuyuki; Herms, Jochen; Rominger, Axel

    2016-05-01

    Abnormal accumulation of tau aggregates in the brain is one of the hallmarks of Alzheimer disease neuropathology. We visualized tau deposition in vivo with the previously developed 2-arylquinoline derivative (18)F-THK5117 using small-animal PET in conjunction with autoradiography and immunohistochemistry gold standard assessment in 2 transgenic mouse models expressing hyperphosphorylated tau. Small-animal PET recordings were obtained in groups of P301S (n = 11) and biGT mice (n = 16) of different ages, with age-matched wild-type (WT) serving as controls. After intravenous administration of 16 ± 2 MBq of (18)F-THK5117, a dynamic 90-min emission recording was initiated for P301S mice and during 20-50 min after injection for biGT mice, followed by a 15-min transmission scan. After coregistration to the MRI atlas and scaling to the cerebellum, we performed volume-of-interest-based analysis (SUV ratio [SUVR]) and statistical parametric mapping. Small-animal PET results were compared with autoradiography ex vivo and in vitro and further validated with AT8 staining for neurofibrillary tangles. SUVRs calculated from static recordings during the interval of 20-50 min after tracer injection correlated highly with estimates of binding potential based on the entire dynamic emission recordings (R = 0.85). SUVR increases were detected in the brain stem of aged P301S mice (+11%; P < 0.001) and in entorhinal/amygdaloidal areas (+15%; P < 0.001) of biGT mice when compared with WT, whereas aged WT mice did not show increased tracer uptake. Immunohistochemical tau loads correlated with small-animal PET SUVR for both P301S (R = 0.8; P < 0.001) and biGT (R = 0.7; P < 0.001) mice, and distribution patterns of AT8-positive neurons matched voxelwise statistical parametric mapping analysis. Saturable binding of the tracer was verified by autoradiographic blocking studies. In the first dedicated small-animal PET study in 2 different transgenic tauopathy mouse models using the tau tracer

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

    PubMed

    Hwang, Jae Pil; Lim, Sang Moo

    2013-06-01

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

  10. Systemic Immune Response to Vaccination on FDG-PET/CT.

    PubMed

    Mingos, Mark; Howard, Stephanie; Giacalone, Nicholas; Kozono, David; Jacene, Heather

    2016-12-01

    A patient with newly diagnosed right lung cancer had transient (18)F-fluorodeoxyglucose (FDG)-avid left axillary lymph nodes and intense splenic FDG uptake on positron emission tomography (PET)/computed tomography (CT). History revealed that the patient received a left-sided influenza vaccine 2-3 days before the examination. Although inflammatory FDG uptake in ipsilateral axillary nodes is reported, to our knowledge, this is the first report of visualization of the systemic immune response in the spleen related to the influenza vaccination on FDG-PET/CT. The history, splenic uptake and time course on serial FDG-PET/CT helped to avoid a false-positive interpretation for progressing lung cancer and alteration of the radiation therapy plan.

  11. Development of a PET/OMRI combined system for simultaneous imaging of positron and free radical probes for small animals.

    PubMed

    Yamamoto, Seiichi; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Ichikawa, Kazuhiro; Nakao, Motonao; Kato, Katsuhiko; Hatazawa, Jun

    2016-10-01

    Positron emission tomography (PET) has high sensitivity for imaging radioactive tracer distributions in subjects. However, it is not possible to image free radical distribution in a subject by PET. Since free radicals are quite reactive, they are related to many diseases, including but not limited to cancer, inflammation, strokes, and heart disease. The Overhauser enhanced magnetic resonance imaging (OMRI) is so far the only method that images free radical distribution in vivo. By combining PET and OMRI, a new hybrid imaging modality might be developed that can simultaneously image the radioactive tracer and free radical distributions. For this purpose, the authors developed a PET/OMRI combined system for small animals. The developed PET/OMRI system used an optical fiber-based PET system combined with a permanent magnet-based OMRI system. The optical fiber-based PET system uses flexible optical fiber bundles. Eight optical fiber-based block detectors were arranged in a 56 mm diameter ring to form a PET system. The LGSO blocks were located inside the field-of-view (FOV) of the OMRI, and the position sensitive photomultiplier tubes were positioned behind the OMRI to minimize the interference between the PET and the OMRI. The OMRI system used a 0.0165 T permanent magnet. The system has an electron spin resonance coil to enhance the MRI signal using the Overhauser effect to image the free radical in the FOV of the PET/OMRI system. The spatial resolution and sensitivity of the optical fiber-based PET system were 1.2 mm FWHM and 1.2% at the central FOV, respectively. The OMRI system imaged the distribution of a nitroxyl radical (NXR) solution. The interference between PET and OMRI was small. Simultaneous imaging of the positron radiotracer and the NXR solution was successfully conducted with the developed PET/OMRI system for phantom and small animal studies. The authors developed a PET/OMRI combined system with the potential to provide interesting new results in

  12. Synthesis and quality control of fluorodeoxyglucose and performance assessment of Siemens MicroFocus 220 small animal PET scanner

    NASA Astrophysics Data System (ADS)

    Phaterpekar, Siddhesh Nitin

    The scope of this article is to cover the synthesis and quality control procedures involved in production of Fludeoxyglucose (18F--FDG). The article also describes the cyclotron production of 18F radioisotope and gives a brief overview on operations and working of a fixed energy medical cyclotron. The quality control procedures for FDG involve radiochemical and radionuclidic purity tests, pH tests, chemical purity tests, sterility tests, endotoxin tests. Each of these procedures were carried out for multiple batches of FDG with a passing rate of 95% among 20 batches. The article also covers the quality assurance steps for the Siemens MicroPET Focus 220 Scanner using a Jaszczak phantom. We have carried out spatial resolution tests on the scanner, with an average transaxial resolution of 1.775mm with 2-3mm offset. Tests involved detector efficiency, blank scan sinograms and transmission sinograms. A series of radioactivity distribution tests are also carried out on a uniform phantom, denoting the variations in radioactivity and uniformity by using cylindrical ROIs in the transverse region of the final image. The purpose of these quality control tests is to make sure the manufactured FDG is biocompatible with the human body. Quality assurance tests are carried on PET scanners for efficient performance, and to make sure the quality of images acquired is according to the radioactivity distribution in the subject of interest.

  13. Performance evaluation of a compact PET/SPECT/CT tri-modality system for small animal imaging applications

    NASA Astrophysics Data System (ADS)

    Wei, Qingyang; Wang, Shi; Ma, Tianyu; Wu, Jing; Liu, Hui; Xu, Tianpeng; Xia, Yan; Fan, Peng; Lyu, Zhenlei; Liu, Yaqiang

    2015-06-01

    PET, SPECT and CT imaging techniques are widely used in preclinical small animal imaging applications. In this paper, we present a compact small animal PET/SPECT/CT tri-modality system. A dual-functional, shared detector design is implemented which enables PET and SPECT imaging with a same LYSO ring detector. A multi-pinhole collimator is mounted on the system and inserted into the detector ring in SPECT imaging mode. A cone-beam CT consisting of a micro focus X-ray tube and a CMOS detector is implemented. The detailed design and the performance evaluations are reported in this paper. In PET imaging mode, the measured NEMA based spatial resolution is 2.12 mm (FWHM), and the sensitivity at the central field of view (CFOV) is 3.2%. The FOV size is 50 mm (∅)×100 mm (L). The SPECT has a spatial resolution of 1.32 mm (FWHM) and an average sensitivity of 0.031% at the center axial, and a 30 mm (∅)×90 mm (L) FOV. The CT spatial resolution is 8.32 lp/mm @10%MTF, and the contrast discrimination function value is 2.06% with 1.5 mm size cubic box object. In conclusion, a compact, tri-modality PET/SPECT/CT system was successfully built with low cost and high performance.

  14. FDG-PET in fever of unknown origin.

    PubMed

    Kouijzer, Ilse J E; Bleeker-Rovers, Chantal P; Oyen, Wim J G

    2013-09-01

    Fever of unknown origin (FUO) is commonly defined as fever higher than 38.3°C on several occasions during at least 3 weeks with uncertain diagnosis after a number of obligatory tests. FUO remains a clinical challenge as no diagnosis is reached in up to 50% of cases. In general, infection accounts for one-fourth of cases of FUO, followed by neoplasm and noninfectious inflammatory diseases. FDG-PET is a sensitive diagnostic technique for the evaluation of FUO. Especially integrated imaging combining PET and CT facilitates anatomical localization of focally increased FDG uptake, thereby guiding further diagnostic tests to achieve a final diagnosis. FDG-PET/CT appears to be a more sensitive diagnostic tool in FUO than stand-alone FDG-PET, because of the precise anatomical localization of small lesions and better differentiation between physiological and pathologic metabolic foci. With FDG-PET/CT becoming widely available, FDG-PET/CT should be a routine procedure in the workup of FUO. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Optimization of LSO/LuYAP phoswich detector for small animal PET

    NASA Astrophysics Data System (ADS)

    Jung, Jin Ho; Choi, Yong; Chung, Yong Hyun; Devroede, Olivier; Krieguer, Magalie; Bruyndonckx, Peter; Tavernier, Stefaan

    2007-02-01

    LSO/LuYAP phoswich detectors for small animal PET were developed to measure the depth of interaction (DOI), and to improve the spatial resolution at the edge of the field of view (FOV). The aim of this study was to optimize the optical coupling conditions between the crystal and photomultiplier tube (PMT) to maximize the light-collection efficiency, and to develop a method for rejecting scatter events by applying an equal energy window in each crystal layer. The light yields of the phoswich detector were estimated by changing the refractive index of the optical coupling material using a DETECT simulation. The accuracy of the DOI measurement on the phoswich detector, using an optical coupling material with the optimal light yield, were evaluated experimentally and compared with the air condition. The energy window for the photopeak events cannot be applied properly because the light outputs of LSO and LuYAP are different. The LSO/LuYAP photopeaks need to be superposed in order to effectively discriminate the scattered events by applying an equal energy window. The photopeaks of the LSO and LuYAP can be superposed by inserting a reflecting material between the crystals. The optimal coverage ratio of the inserting material was derived from a DETECT simulation, and its performance was investigated. In the simulation result, optimal refractive index of the optical coupling material was 1.7. The average DOI measurement errors of the LSO/LuYAP were 0.6%/3.4% and 4.9%/41.4% in the phoswich detector with and without an optical coupling material, respectively. The photopeaks of the LSO and LuYAP were superposed by covering 75% of the contact surface between the crystals with white Teflon. The DOI measurement errors of the LSO/LuYAP were 0.2%/2.4%. In this study, the optimal condition of the optical coupling material inserted between the crystal and PMT was derived to improve the accuracy of DOI measurement, and a photopeak superposition method of the LSO and LuYAP was

  16. Detector development for microPET II: a 1 μl resolution PET scanner for small animal imaging

    NASA Astrophysics Data System (ADS)

    Chatziioannou, A.; Tai, Y. C.; Doshi, N.; Cherry, S. R.

    2001-11-01

    We are currently developing a small animal positron emission tomography (PET) scanner with a design goal of 1 microlitre (1 mm3) image resolution. The detectors consist of a 12 × 12 array of 1 × 1 × 10 mm lutetium oxyorthosilicate (LSO) scintillator crystals coupled to a 64-channel photomultiplier tube (PMT) via 5 cm long optical fibre bundles. The optical fibre connection allows a high detector packing fraction despite the dead space surrounding the active region of the PMT. Optical fibre bundles made from different types of glass were tested for light transmission, and also their effects on crystal identification and energy resolution, and compared to direct coupling of the LSO arrays to the PMTs. We also investigated the effects of extramural absorber (EMA) in the fibre bundles. Based on these results, fibre bundles manufactured from F2 glass were selected. We built three pairs of prototype detectors (directly coupled LSO array, fibre bundle without EMA and fibre bundle with EMA) and measured flood histograms, energy resolution, intrinsic spatial resolution and timing resolution. The results demonstrated an intrinsic spatial resolution (FWHM) of 1.12 mm (directly coupled), 1.23 mm (fibre bundle without EMA coupling) and 1.27 mm (fibre bundle with EMA coupling) using an approximately 500 μm diameter Na-22 point source. Using a 330 μm outer diameter steel needle line source filled with F-18, spatial resolution for the detector with the EMA optical fibre bundle improved to 1.05 mm. The respective timing and energy FWHM values were 1.96 ns, 21% (directly coupled), 2.20 ns, 23% (fibre bundle without EMA) and 2.99 ns, 30% (fibre bundle with EMA). The peak-to-valley ratio in the flood histograms was better with EMA (5:1) compared to the optical fibre bundle without EMA (2.5:1), due to the decreased optical cross-talk. In comparison to the detectors used in our current generation microPET scanner, these detectors substantially improve on the spatial resolution

  17. FDG μPET Fails to Detect a Disease-Specific Phenotype in Rats Transgenic for Huntington's Disease – A 15 Months Follow-up Study.

    PubMed

    Reilmann, Ralf; Lippross, Veronika; Hölzner, Eva; Gigengack, Fabian; Bohlen, Stefan; Kugel, Harald; Deppe, Michael; Osada, Nani; Lücke, M; Riess, Olaf; Nguyen, Huu Phuc; Von Hörsten, Stephan; Schäfers, Klaus; Schäfers, Michael; Jacobs, Andreas H; Hermann, Sven

    2015-01-01

    FDG-PET detects hypometabolism in premanifest and symptomatic Huntington's disease (HD). A cross-sectional study suggested that whole-brain FDG-PET is capable to detect a phenotype in transgenic (tg) HD rats. Recently, a longitudinal follow-up study showed no FDG-PET changes in tgHD rats. Both studies applied small sample sizes and analysis was limited to whole-brain or striatum. We therefore performed a follow-up study in a larger cohort of tgHD and wild-type (wt) rats encompassing several pre-defined regions of interest (ROIs) and hypothesis free voxel-by-voxel SPM analysis to clarify whether FDG-PET can detect a phenotype in tgHD rats and to determine onset …and effect sizes of changes over time. N = 19 tgHD- and n = 20 wt-rats, mixed gender, were included. Repeated small animal FDG-μPET and MRI were performed at 5,10,15, and 20 months of age. ROIs encompassing entire brain, cortex, striatum, thalamus, subventricular-zone, and cerebellum were placed manually on the MRI and transferred to the co-registered μPET. Mean and maximal FDG-PET activities within ROIs were calculated and normalized to cerebellar FDG uptake. Activity and spatially normalized FDG-μPET were compared between groups on a hypothesis-free voxel-by-voxel basis using SPM. FDG uptake showed changes over time in both tgHD- and wt-rats, however, there was no consistent difference between tgHD- and wt-rats in both the manual ROI and SPM analysis. In this transgenic rat model of HD FDG-μPET imaging does not detect significant alterations at the ages investigated. Further investigations are warranted employing other age groups and alternative imaging biomarkers for neuronal degeneration, respectively.

  18. FDG PET/CT in Type I Glycogen Storage Disease.

    PubMed

    Manca, Chloé; Claudin, Marine; Belle, Arthur; Marie, Pierre Yves; Verger, Antoine

    2016-04-01

    Type I glycogen storage disease (GSD) is a rare autosomal recessive disorder caused by glucose-6-phosphatase deficiency. We report herein the particular pattern provided by FDG PET imaging in a 33-year-old patient with type Ib GSD. PET images yielded evidence of a pulmonary infectious focus as well as of: (1) a dramatically enlarged liver leading to a high global FDG uptake, (2) increased bone marrow activity, (3) splenomegalia leading to a high global spleen uptake, (4) a diffuse enhancement in muscle FDG uptake.

  19. FDG PET/CT findings of common bile duct tuberculosis.

    PubMed

    Dong, Aisheng; Wang, Yang; Gong, Jing; Zuo, Changjing

    2014-01-01

    Common bile duct (CBD) tuberculosis is rare. A 39-year-old woman was referred because of a 5-month history of abdominal pain. Abdominal enhanced MRI and CT showed dilatation of the distal CBD with irregularly thickened wall. Enhanced CT revealed enlarged retroperitoneal lymph nodes. FDG PET/CT showed increased FDG uptake of the CBD lesion and several retroperitoneal lymph nodes with slight FDG uptake. CBD cholangiocarcinoma with retroperitoneal lymph node metastasis was suspected. CBD tuberculosis was confirmed by endoluminal biopsy. Tuberculosis should be considered in the differential diagnosis of abnormal biliary FDG accumulation, particularly in tuberculosis endemic areas.

  20. Transient Osteoporosis of the Hip on FDG PET/CT.

    PubMed

    Ulaner, Gary A; Sawan, Peter

    2017-05-01

    Transient osteoporosis of the hip (TOH) is characterized by bone pain, osteopenia, and bone marrow edema in the absence of trauma. We present a 59-year-old man with chronic lymphocytic leukemia who underwent F-FDG PET/CT. F-FDG PET/CT demonstrated mildly FDG-avid lymph nodes consistent for chronic lymphocytic leukemia, as well as FDG-avidity in the right femoral head with corresponding osteopenia, rather than a focal lytic lesion. MR demonstrated bone marrow edema consistent with TOH. TOH is benign and self-limiting. Corresponding imaging may prevent misdiagnosis of benign FDG-avid TOH as other more severe hip processes such as tumors or infection.

  1. FDG-PET/CT in the evaluation of anal carcinoma

    SciTech Connect

    Cotter, Shane E.; Grigsby, Perry W. . E-mail: pgrigsby@wustl.edu; Siegel, Barry A.

    2006-07-01

    Purpose: Surgical staging and treatment of anal carcinoma has been replaced by noninvasive staging studies and combined modality therapy. In this study, we compare computed tomography (CT) and physical examination to [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the staging of carcinoma of the anal canal, with special emphasis on determination of spread to inguinal lymph nodes. Methods and Materials: Between July 2003 and July 2005, 41 consecutive patients with biopsy-proved anal carcinoma underwent a complete staging evaluation including physical examination, CT, and 2-FDG-PET/CT. Patients ranged in age from 30 to 89 years. Nine men were HIV-positive. Treatment was with standard Nigro regimen. Results: [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) detected 91% of nonexcised primary tumors, whereas CT visualized 59%. FDG-PET/CT detected abnormal uptake in pelvic nodes of 5 patients with normal pelvic CT scans. FDG-PET/CT detected abnormal nodes in 20% of groins that were normal by CT, and in 23% without abnormality on physical examination. Furthermore, 17% of groins negative by both CT and physical examination showed abnormal uptake on FDG-PET/CT. HIV-positive patients had an increased frequency of PET-positive lymph nodes. Conclusion: [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography detects the primary tumor more often than CT. FDG-PET/CT detects substantially more abnormal inguinal lymph nodes than are identified by standard clinical staging with CT and physical examination.

  2. Quantitative techniques in 18FDG PET scanning in oncology.

    PubMed

    Castell, F; Cook, G J R

    2008-05-20

    The clinical applications of (18)F-fluoro-2-deoxyglucose ((18)FDG) positron emission tomography (PET) in oncology are becoming established. While simple static scanning techniques are used for the majority of routine clinical examinations, increasing use of PET in clinical trials to monitor treatment response with (18)FDG and novel tracers reflecting different pharmacodynamic end points, often necessitates a more complex and quantitative analysis of radiopharmaceutical kinetics. A wide range of PET analysis techniques exist, ranging from simple visual analysis and semiquantitative methods to full dynamic studies with kinetic analysis. These methods are discussed, focusing particularly on the available methodologies that can be utilised in clinical trials.

  3. 18F-FDG PET/CT in Detecting Metastatic Infection in Children.

    PubMed

    Kouijzer, Ilse J E; Blokhuis, Gijsbert J; Draaisma, Jos M T; Oyen, Wim J G; de Geus-Oei, Lioe-Fee; Bleeker-Rovers, Chantal P

    2016-04-01

    Metastatic infection is a severe complication of bacteremia with high morbidity and mortality. The aim of this study was to investigate the diagnostic value of 18F-FDG PET combined with CT (FDG PET/CT) in children suspected of having metastatic infection. The results of FDG PET/CT scans performed in children because of suspected metastatic infection from September 2003 to June 2013 were analyzed retrospectively. The results were compared with the final clinical diagnosis. FDG PET/CT was performed in 13 children with suspected metastatic infection. Of the total number of FDG PET/CT scans, 38% were clinically helpful. Positive predictive value of FDG PET/CT was 71%, and negative predictive value was 100%. FDG PET/CT appears to be a valuable diagnostic technique in children with suspected metastatic infection. Prospective studies of FDG PET/CT as part of a structured diagnostic protocol are needed to assess the exact additional diagnostic value.

  4. Preliminary assessment of the imaging capability of the YAP (S)PET small animal scanner in neuroscience

    NASA Astrophysics Data System (ADS)

    Bartoli, Antonietta; Belcari, Nicola; Stark, Daniela; Höhnemann, Sabine; Piel, Markus; Jennewein, Marc; Schmitt, Ulrich; Tillmanns, Julia; Thews, Oliver; Hiemke, Christoph; Roesch, Frank; Del Guerra, Alberto

    2006-12-01

    The new and fully engineered version of the YAP-(S)PET small animal scanner has been tested at the University of Mainz for preliminary assessment of its imaging capability for studies related to neuropharmacology and psychiatry. The main feature of the scanner is the capability to combine PET and SPECT techniques. It allows the development of new and interesting protocols for the investigation of many biological phenomena, more effectively than with PET or SPECT modalities alone. The scanner is made up of four detector heads, each one composed of a 4×4 cm 2 of YAlO 3:Ce (or YAP:Ce) matrix, and has a field of view (FOV) of 4 cm axially×4 cm ∅ transaxially. In PET mode, the volume resolution is less than 8 mm 3 and is nearly constant over the whole FOV, while the sensitivity is about 2%. The SPECT performance is not so good, due to the presence of the multi-hole lead collimator in front of each head. Nevertheless, the YAP-PET scanner offers excellent resolution and sensitivity for performing on the availability of D2-like dopamine receptors on mice and rats in both PET and SPECT modalities.

  5. Comparison of 18F-FDG-PET/CT and 18F-FDG-PET/MR imaging in oncology: a systematic review.

    PubMed

    Singnurkar, Amit; Poon, Raymond; Metser, Ur

    2017-06-01

    The aim of this study was to systematically review the literature to evaluate the clinical performance of integrated (18)F-FDG PET/MR as compared with (18)F-FDG PET/CT in oncologic imaging. The literature was searched using MEDLINE and EMBASE via OVID. Studies comparing the diagnostic accuracy of integrated (18)F-FDG PET/MR and (18)F-FDG PET/CT in the diagnosis, staging/restaging, assessment of treatment response, or evaluation of metastasis in patients with suspected or diagnosed cancers were deemed eligible for inclusion. Risk of bias and applicability concerns were assessed using the QUADAS-2 tool. Twenty studies met the inclusion criteria. The overall quality of the studies was rated favorably with bias or applicability concerns in a few studies. Our review suggests that (18)F-FDG PET/MR performs comparably to (18)F-FDG PET/CT in the detection of local lymph node and distant metastases and superiorly in determining the local extent of tumor. SUV obtained from (18)F-FDG PET/MR correlated highly with those obtained from (18)F-FDG PET/CT. Based on early evidence, (18)F-FDG PET/MR is comparable to (18)F-FDG PET/CT in the clinical scenarios examined in this review. The potential for interchangeability of (18)F-FDG PET/MR with (18)F-FDG PET/CT will vary by indication and the body site that is being imaged, with PET scanners integrated with MRI predicted to provide greater detail in the evaluation of local tumor extent, where (18)F-FDG PET/CT can be limited.

  6. [18F FDG PET-Applications in Oncology].

    PubMed

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

    2002-01-01

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

  7. Simulation Study of Spatial Resolution and Sensitivity for Tapered Depth of Interaction PET Detectors for Small Animal Imaging

    PubMed Central

    James, Sara St.; Yang, Yongfeng; Bowen, Spencer L.; Qi, Jinyi; Cherry, Simon R.

    2011-01-01

    Improvements to current small animal PET scanners can be made by improving the sensitivity and the spatial resolution of the scanner. In the past, efforts have been made to minimize the crystal dimensions in the axial and transaxial directions to improve the spatial resolution and to increase the crystal length to improve the sensitivity of the scanner. We have designed tapered PET detectors with the purpose of reducing the gaps between detector modules and optimizing the sensitivity of a future generation small animal PET scanner. In this work, we investigate spatial resolution and sensitivity of a scanner based on tapered detector elements using Monte Carlo simulations. For tapered detector elements more scintillation material is used per detector resulting in a higher sensitivity of the scanner. However, since the detector elements are not uniform in size, degradation in spatial resolution is also expected. To investigate characteristics of tapered PET detectors the spatial resolution and sensitivity of a one-ring scanner were simulated for a system based on traditional cuboid detectors and a scanner based on tapered detectors. Additionally, the effect of depth of interaction (DOI) resolution on the spatial resolution for the traditional and tapered detectors was evaluated. All simulations were performed using the Monte Carlo simulation package GATE. Using the tapered arrays a 64 % improvement in the sensitivity across the field of view was found compared with traditional detectors for the same ring diameter. The level of DOI encoding was found to be the dominating factor in determining the radial spatial resolution and not the detector shape. For all levels of DOI encoding, no significant difference was found for the spatial resolution when comparing the tapered and the cuboid detectors. Detectors employing the tapered crystal design along with excellent DOI resolution will lead to PET scanners with higher sensitivity and uniform spatial resolution across the

  8. An atypical sarcoidosis involvement in FDG PET/CT

    PubMed Central

    Robin, Philippe; Benigni, Paolo; Feger, Benoit; Salaun, Pierre-Yves; Abgral, Ronan

    2016-01-01

    Abstract Rationale: Sarcoidosis is an idiopathic systemic inflammatory granulomatous disorder comprised of epithelioid and multinucleated giant cells with little necrosis which involve various organs. Laryngeal involvement is extremely rare, with a prevalence of about 0.5 to 1%. Diagnoses: Here we present a case of laryngeal involvement of sarcoidosis demonstrated on 18F-Fluorodesoxyglucose Positron-Emission Tomography/Computed Tomography (FDG PET/CT). Patient concerns: A 63 year-old man suffering from dysphonia was referred to our department for characterization of laryngeal lesion suspicious for cancer with non-informative biopsy, the sample was not sufficient for diagnosis. Interventions: FDG PET/CT showed a pathological uptake on the right vocal cord, but also highlighted a bilateral uptake in intrathoracic hilar lymphadenopathy areas, typically found in several inflammatory diseases. Outcomes: New laryngeal targeted biopsies revealed non-caseating epithelioid granulomas suggesting sarcoidosis involvement. After 6 months of systemic steroid treatment, FDG PET/CT showed a significant decrease of the laryngeal uptake. Lessons: This case shows the usefulness of FDG PET/CT to accurately assess inflammatory activity in rare extra-pulmonary sarcoidosis involvement. Moreover, this case emphasizes that FDG PET/CT is an interesting tool for assessing therapeutic efficacy of inflammatory diseases such as sarcoidosis. PMID:28033265

  9. Preparedness of small animal veterinary practices to communicate with Spanish-speaking pet owners with limited proficiency in English.

    PubMed

    Landau, Ruth E; Beck, Alan; Glickman, Larry T; Litster, Annette; Widmar, Nicole J Olynk; Moore, George E

    2016-03-15

    To investigate the preparedness of small animal veterinary personnel to communicate with Spanish-speaking pet owners with limited English-language proficiency (LEP). Cross-sectional telephone survey. Data from 383 small animal veterinary practices. Telephone surveys were conducted with veterinarians and office or practice managers from a random sample of US small animal veterinary practices in 10 states to estimate the number of Spanish-speaking pet owners with LEP visiting these practices, proportion of practices that used services to facilitate communication with Spanish-speaking clients with LEP, and degree of veterinarian satisfaction with their communication with those clients. Responses were obtained from 383 of 1,245 (31%) eligible practices, of which 340 (89%) had Spanish-speaking clients with LEP and 200 (52%) had such clients on a weekly basis. Eight percent of practices had veterinary personnel who were conversant or fluent in spoken Spanish. Veterinarians who depended on clients' friends or family to translate were significantly less satisfied with client communication than were those who could converse in Spanish with clients directly. Availability of Spanish-speaking staff and offering of Spanish-language resources were associated with an increase in the number of Spanish-speaking clients with LEP seen on a weekly basis. Industry- and practice-generated Spanish-language materials were offered at 32% (124/383) and 21% (81/383) of practices, respectively; 329 (86%) practices had no Spanish-language marketing. Opportunities were identified for improving communication with pet owners with LEP in the veterinary clinical setting, which could ultimately positively impact patient well-being and client compliance.

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2015-09-01

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

  12. Noise Reduction in Small Animal PET Images Using a Variational Non-Convex Functional

    NASA Astrophysics Data System (ADS)

    Mejia, Jose; Mederos, Boris; Mollineda, Ramón A.; Ortega Maynez, Leticia

    2016-10-01

    Positron emission tomography (PET) imaging is widely used in nuclear medicine. However, data acquired by a PET system are generally contaminated with heavy noise, which often persists after image reconstruction. In this paper, a novel non-convex functional is introduced to suitably attenuate noise in PET images. The proposed functional contains a new regularization term defined as a convex combination of two terms: a robust function for border preserving and the L2 semi-norm. The combination coefficient depends on the gradient of the noisy image, so that it allows a selective smoothing of image regions according to their local characteristics. The proposed method has been qualitatively and quantitatively tested on both simulated and measured data, demonstrating its better performance against well-established methods for PET denoising.

  13. Small Animal Care.

    ERIC Educational Resources Information Center

    Livesey, Dennis W.; Fong, Stephen

    This small animal care course guide is designed for students who will be seeking employment in veterinary hospitals, kennels, grooming shops, pet shops, and small-animal laboratories. The guide begins with an introductory section that gives the educational philosophy of the course, job categories and opportunities, units of instruction required…

  14. Small Animal Care.

    ERIC Educational Resources Information Center

    Livesey, Dennis W.; Fong, Stephen

    This small animal care course guide is designed for students who will be seeking employment in veterinary hospitals, kennels, grooming shops, pet shops, and small-animal laboratories. The guide begins with an introductory section that gives the educational philosophy of the course, job categories and opportunities, units of instruction required…

  15. Effect of Carbidopa on 18F-FDOPA Uptake in Insulinoma: From Cell Culture to Small-Animal PET Imaging.

    PubMed

    Detour, Julien; Pierre, Alice; Boisson, Fréderic; Kreutter, Guillaume; Lavaux, Thomas; Namer, Izzie Jacques; Kessler, Laurence; Brasse, David; Marchand, Patrice; Imperiale, Alessio

    2017-01-01

    Patient premedication with carbidopa seems to improve the accuracy of 6-(18)F-fluoro-3,4-dihydroxy-l-phenylalanine ((18)F-FDOPA) PET for insulinoma diagnosis. However, the risk of PET false-negative results in the presence of carbidopa is a concern. Consequently, we aimed to evaluate the effect of carbidopa on (18)F-FDOPA uptake in insulinoma β-cells and an insulinoma xenograft model in mice. (18)F-FDOPA in vitro accumulation was assessed in the murine β-cell line RIN-m5F. In vivo small-animal PET experiments were performed on tumor-bearing nude mice after subcutaneous injection of RIN-m5F cells. Experiments were conducted with and without carbidopa pretreatment. Incubation of RIN-m5F cells with 80 μM carbidopa did not significantly affect the cellular accumulation of (18)F-FDOPA. Tumor xenografts were clearly detectable by small-animal PET in all cases. Insulinoma xenografts in carbidopa-treated mice showed significantly higher (18)F-FDOPA uptake than those in nontreated mice. Regardless of carbidopa premedication, the xenografts were characterized by an early increase in (18)F-FDOPA uptake and then a progressive reduction over time. Carbidopa did not influence in vitro (18)F-FDOPA accumulation in RIN-m5F cells but improved insulinoma imaging in vivo. Our findings increase current knowledge about the (18)F-FDOPA uptake profile of RIN-m5F cells and a related xenograft model. To our knowledge, the present work represents the first preclinical research specifically focused on insulinomas, with potential translational implications. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  16. FDG-PET evaluation of indeterminate pancreatic masses

    SciTech Connect

    Ho, Chi-Lai; Dehdashti, Farrokh; Griffeth, L.K.

    1996-05-01

    The purpose of this study was to assess the-ability of PET with 2-[{sup 18}F]fluoro-2-deoxy-D-glucose (FDG) to differentiate benign from malignant pancreatic masses in patients with indeterminate findings on CT. We performed FDG-PET on 12 patients with indeterminate mass lesions and 2 patients with CT findings typical for malignancy. Eight were found to have pancreatic carcinoma and six had benign lesions. The final diagnosis was histopathologically confirmed in all patients but two with a presumed diagnosis of focal pancreatitis based on stable clinical follow-up for at least 12 months. Lesion uptake of FDG was evaluated qualitatively and semi-quantitatively by determination of the standardized uptake value (SUV). With use of a 2.5 cutoff value for SUV, all eight malignant and four of six benign lesions were correctly categorized. Qualitative evaluation gave the same results. The two false-positive lesions had elevated SUV values of 3.4 and 3.8, respectively. Our results indicate that FDG-PET has potential value for assessing patients with CT findings that are indeterminate for pancreatic carcinoma. FDG-PET may obviate invasive diagnostic procedures in many patients with benign disease. 36 refs., 2 figs., 1 tab.

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

    PubMed

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

    2014-10-01

    Positron emission tomography (PET) imaging with 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG) forms the basis of molecular imaging. FDG-PET imaging is a multidisciplinary undertaking that requires close interdisciplinary collaboration in a broad team comprising physicians, technologists, secretaries, radio-chemists, hospital physicists, molecular biologists, engineers, and cyclotron technicians. The aim of this review is to provide a brief overview of important basic issues and considerations pivotal to successful patient examinations, including basic physics, instrumentation, radiochemistry, molecular and cell biology, patient preparation, normal distribution of tracer, and potential interpretive pitfalls. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. A computational pipeline for quantification of pulmonary infections in small animal models using serial PET-CT imaging.

    PubMed

    Bagci, Ulas; Foster, Brent; Miller-Jaster, Kirsten; Luna, Brian; Dey, Bappaditya; Bishai, William R; Jonsson, Colleen B; Jain, Sanjay; Mollura, Daniel J

    2013-07-23

    Infectious diseases are the second leading cause of death worldwide. In order to better understand and treat them, an accurate evaluation using multi-modal imaging techniques for anatomical and functional characterizations is needed. For non-invasive imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), there have been many engineering improvements that have significantly enhanced the resolution and contrast of the images, but there are still insufficient computational algorithms available for researchers to use when accurately quantifying imaging data from anatomical structures and functional biological processes. Since the development of such tools may potentially translate basic research into the clinic, this study focuses on the development of a quantitative and qualitative image analysis platform that provides a computational radiology perspective for pulmonary infections in small animal models. Specifically, we designed (a) a fast and robust automated and semi-automated image analysis platform and a quantification tool that can facilitate accurate diagnostic measurements of pulmonary lesions as well as volumetric measurements of anatomical structures, and incorporated (b) an image registration pipeline to our proposed framework for volumetric comparison of serial scans. This is an important investigational tool for small animal infectious disease models that can help advance researchers' understanding of infectious diseases. We tested the utility of our proposed methodology by using sequentially acquired CT and PET images of rabbit, ferret, and mouse models with respiratory infections of Mycobacterium tuberculosis (TB), H1N1 flu virus, and an aerosolized respiratory pathogen (necrotic TB) for a total of 92, 44, and 24 scans for the respective studies with half of the scans from CT and the other half from PET. Institutional Administrative Panel on Laboratory Animal Care approvals were

  19. A computational pipeline for quantification of pulmonary infections in small animal models using serial PET-CT imaging

    PubMed Central

    2013-01-01

    Background Infectious diseases are the second leading cause of death worldwide. In order to better understand and treat them, an accurate evaluation using multi-modal imaging techniques for anatomical and functional characterizations is needed. For non-invasive imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), there have been many engineering improvements that have significantly enhanced the resolution and contrast of the images, but there are still insufficient computational algorithms available for researchers to use when accurately quantifying imaging data from anatomical structures and functional biological processes. Since the development of such tools may potentially translate basic research into the clinic, this study focuses on the development of a quantitative and qualitative image analysis platform that provides a computational radiology perspective for pulmonary infections in small animal models. Specifically, we designed (a) a fast and robust automated and semi-automated image analysis platform and a quantification tool that can facilitate accurate diagnostic measurements of pulmonary lesions as well as volumetric measurements of anatomical structures, and incorporated (b) an image registration pipeline to our proposed framework for volumetric comparison of serial scans. This is an important investigational tool for small animal infectious disease models that can help advance researchers’ understanding of infectious diseases. Methods We tested the utility of our proposed methodology by using sequentially acquired CT and PET images of rabbit, ferret, and mouse models with respiratory infections of Mycobacterium tuberculosis (TB), H1N1 flu virus, and an aerosolized respiratory pathogen (necrotic TB) for a total of 92, 44, and 24 scans for the respective studies with half of the scans from CT and the other half from PET. Institutional Administrative Panel on Laboratory Animal

  20. Small-Animal Molecular Imaging for Preclinical Cancer Research: .μPET and μ.SPECT.

    PubMed

    Cuccurullo, Vincenzo; Di Stasio, Giuseppe D; Schillirò, Maria L; Mansi, Luigi

    2016-01-01

    Due to different sizes of humans and rodents, the performance of clinical imaging devices is not enough for a scientifically reliable evaluation in mice and rats; therefore dedicated small-animal systems with a much higher sensitivity and spatial resolution, compared to the ones used in humans, are required. Smallanimal imaging represents a cutting-edge research method able to approach an enormous variety of pathologies in which animal models of disease may be used to elucidate the mechanisms underlying the human condition and/or to allow a translational pharmacological (or other) evaluation of therapeutic tools. Molecular imaging, avoiding animal sacrifice, permits repetitive (i.e. longitudinal) studies on the same animal which becomes its own control. In this way also the over time evaluation of disease progression or of the treatment response is enabled. Many different rodent models have been applied to study almost all kind of human pathologies or to experiment a wide series of drugs and/or other therapeutic instruments. In particular, relevant information has been achieved in oncology by in vivo neoplastic phenotypes, obtained through procedures such as subcutaneous tumor grafts, surgical transplantation of solid tumor, orthotopic injection of tumor cells into specific organs/sites of interest, genetic modification of animals to promote tumor-genesis; in this way traditional or innovative treatments, also including gene therapy, of animals with a cancer induced by a known carcinogen may be experimented. Each model has its own disadvantage but, comparing different studies, it is possible to achieve a panoramic and therefore substantially reliable view on the specific subject. Small-animal molecular imaging has become an invaluable component of modern biomedical research that will gain probably an increasingly important role in the next few years.

  1. Simultaneous acquisition of magnetic resonance spectroscopy (MRS) data and positron emission tomography (PET) images with a prototype MR-compatible, small animal PET imager

    NASA Astrophysics Data System (ADS)

    Raylman, Raymond R.; Majewski, Stan; Velan, S. Sendhil; Lemieux, Susan; Kross, Brian; Popov, Vladimir; Smith, Mark F.; Weisenberger, Andrew G.

    2007-06-01

    Multi-modality imaging (such as PET-CT) is rapidly becoming a valuable tool in the diagnosis of disease and in the development of new drugs. Functional images produced with PET, fused with anatomical images created by MRI, allow the correlation of form with function. Perhaps more exciting than the combination of anatomical MRI with PET, is the melding of PET with MR spectroscopy (MRS). Thus, two aspects of physiology could be combined in novel ways to produce new insights into the physiology of normal and pathological processes. Our team is developing a system to acquire MRI images and MRS spectra, and PET images contemporaneously. The prototype MR-compatible PET system consists of two opposed detector heads (appropriate in size for small animal imaging), operating in coincidence mode with an active field-of-view of ˜14 cm in diameter. Each detector consists of an array of LSO detector elements coupled through a 2-m long fiber optic light guide to a single position-sensitive photomultiplier tube. The use of light guides allows these magnetic field-sensitive elements of the PET imager to be positioned outside the strong magnetic field of our 3T MRI scanner. The PET scanner imager was integrated with a 12-cm diameter, 12-leg custom, birdcage coil. Simultaneous MRS spectra and PET images were successfully acquired from a multi-modality phantom consisting of a sphere filled with 17 brain relevant substances and a positron-emitting radionuclide. There were no significant changes in MRI or PET scanner performance when both were present in the MRI magnet bore. This successful initial test demonstrates the potential for using such a multi-modality to obtain complementary MRS and PET data.

  2. 18F-FDG PET and PET/CT in fever of unknown origin.

    PubMed

    Meller, Johannes; Sahlmann, Carsten-Oliver; Scheel, Alexander Konrad

    2007-01-01

    Fever of unknown origin (FUO) was originally defined as recurrent fever of 38.3 degrees C or higher, lasting 2-3 wk or longer, and undiagnosed after 1 wk of hospital evaluation. The last criterion has undergone modification and is now generally interpreted as no diagnosis after appropriate inpatient or outpatient evaluation. The 3 major categories that account for most FUOs are infections, malignancies, and noninfectious inflammatory diseases. The diagnostic approach in FUO includes repeated physical investigations and thorough history-taking combined with standardized laboratory tests and simple imaging procedures. Nevertheless, there is a need for more complex or invasive techniques if this strategy fails. This review describes the impact of (18)F-FDG PET in the diagnostic work-up of FUO. (18)F-FDG accumulates in malignant tissues but also at the sites of infection and inflammation and in autoimmune and granulomatous diseases by the overexpression of distinct facultative glucose transporter (GLUT) isotypes (mainly GLUT-1 and GLUT-3) and by an overproduction of glycolytic enzymes in cancer cells and inflammatory cells. The limited data of prospective studies indicate that (18)F-FDG PET has the potential to play a central role as a second-line procedure in the management of patients with FUO. In these studies, the PET scan contributed to the final diagnosis in 25%-69% of the patients. In the category of infectious diseases, a diagnosis of focal abdominal, thoracic, or soft-tissue infection, as well as chronic osteomyelitis, can be made with a high degree of certainty. Negative findings on (18)F-FDG PET essentially rule out orthopedic prosthetic infections. In patients with noninfectious inflammatory diseases, (18)F-FDG PET is of importance in the diagnosis of large-vessel vasculitis and seems to be useful in the visualization of other diseases, such as inflammatory bowel disease, sarcoidosis, and painless subacute thyroiditis. In patients with tumor fever, diseases

  3. Automatic Channel Fault Detection on a Small Animal APD-Based Digital PET Scanner

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    Avalanche photodiode (APD) based positron emission tomography (PET) scanners show enhanced imaging capabilities in terms of spatial resolution and contrast due to the one to one coupling and size of individual crystal-APD detectors. However, to ensure the maximal performance, these PET scanners require proper calibration by qualified scanner operators, which can become a cumbersome task because of the huge number of channels they are made of. An intelligent system (IS) intends to alleviate this workload by enabling a diagnosis of the observational errors of the scanner. The IS can be broken down into four hierarchical blocks: parameter extraction, channel fault detection, prioritization and diagnosis. One of the main activities of the IS consists in analyzing available channel data such as: normalization coincidence counts and single count rates, crystal identification classification data, energy histograms, APD bias and noise thresholds to establish the channel health status that will be used to detect channel faults. This paper focuses on the first two blocks of the IS: parameter extraction and channel fault detection. The purpose of the parameter extraction block is to process available data on individual channels into parameters that are subsequently used by the fault detection block to generate the channel health status. To ensure extensibility, the channel fault detection block is divided into indicators representing different aspects of PET scanner performance: sensitivity, timing, crystal identification and energy. Some experiments on a 8 cm axial length LabPET scanner located at the Sherbrooke Molecular Imaging Center demonstrated an erroneous channel fault detection rate of 10% (with a 95% confidence interval (CI) of [9, 11]) which is considered tolerable. Globally, the IS achieves a channel fault detection efficiency of 96% (CI: [95, 97]), which proves that many faults can be detected automatically. Increased fault detection efficiency would be

  4. Segmentation of PET Images for Computer-Aided Functional Quantification of Tuberculosis in Small Animal Models

    PubMed Central

    Foster, Brent; Bagci, Ulas; Xu, Ziyue; Dey, Bappaditya; Luna, Brian; Bishai, William; Jain, Sanjay; Mollura, Daniel J.

    2014-01-01

    Pulmonary infections often cause spatially diffuse and multi-focal radiotracer uptake in positron emission tomography (PET) images, which makes accurate quantification of the disease extent challenging. Image segmentation plays a vital role in quantifying uptake due to the distributed nature of immuno-pathology and associated metabolic activities in pulmonary infection, specifically tuberculosis (TB). For this task, thresholding-based segmentation methods may be better suited over other methods; however, performance of the thresholding-based methods depend on the selection of thresholding parameters, which are often suboptimal. Several optimal thresholding techniques have been proposed in the literature, but there is currently no consensus on how to determine the optimal threshold for precise identification of spatially diffuse and multi-focal radiotracer uptake. In this study, we propose a method to select optimal thresholding levels by utilizing a novel intensity affinity metric within the affinity propagation clustering framework. We tested the proposed method against 70 longitudinal PET images of rabbits infected with TB. The overall dice similarity coefficient between the segmentation from the proposed method and two expert segmentations was found to be 91.25 ± 8.01% with a sensitivity of 88.80 ± 12.59% and a specificity of 96.01 ± 9.20%. High accuracy and heightened efficiency of our proposed method, as compared to other PET image segmentation methods, were reported with various quantification metrics. PMID:24235292

  5. Performance evaluation of a 90°-rotating dual-head small animal PET system

    NASA Astrophysics Data System (ADS)

    Zhang, Chunhui; Chen, Xueli; Zhu, Shouping; Wan, Lu; Xie, Qingguo; Liang, Jimin

    2015-08-01

    Dual-head PET system suffers from poor resolution in the dimension perpendicular to the detector heads and vastly increased computations required by the accurate estimation of the system response matrix (SRM). The problem of poor x-axis resolution is caused by missing data owing to the intrinsic geometry flaws of the dual-head PET, which leads to high SRM similarity between the adjacent voxels along the x-axis. To compensate for this problem, our dual-head PET system prototype incorporates a {{90}{^\\circ}} -rotating mechanism. In addition, the cubic field of view (FOV) and cubic voxels are adopted to achieve a better geometrical symmetry, which avoids the re-estimation of SRM after rotation. The spatial resolution, sensitivity, noise equivalent count rate, scatter fraction and pileup fraction under different head separation distances were evaluated by a series of simulations, and the results were compared with those of the non-rotation system. The SRM was estimated using the Monte Carlo method and the three-dimensional images were reconstructed using the ordered subsets expectation maximization algorithm. Experimental results reveal a significantly improved x-axis resolution via the proposed rotation mechanism. Our system can achieve x-axis spatial resolution of 0.79 mm, 0.74 mm and 0.72 mm at the center of FOV under the head separation distance of 5 cm, 10 cm and 15 cm, respectively.

  6. Thorax: normal and benign pathologic patterns in FDG-PET/CT imaging.

    PubMed

    Wachsmann, Jason W; Gerbaudo, Victor H

    2014-04-01

    This article describes the normal patterns of thoracic (18)F-fluorodeoxyglucose (FDG) biodistribution, and expands on the role of FDG-PET/computed tomography (CT) for the evaluation of patients suffering from a spectrum of benign pathologic conditions that affect the chest. The discussion addresses the applications of FDG-PET/CT imaging in a wide variety of chest-related disorders. Familiarity with the normal thoracic biodistribution of FDG, coupled with knowledge of the potential nonmalignant causes of increased FDG uptake in the chest, is essential to minimize the incidence of incorrect interpretation of FDG-PET images in daily clinical practice. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Design considerations for a C-shaped PET system, dedicated to small animal brain imaging, using GATE Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Efthimiou, N.; Papadimitroulas, P.; Kostou, T.; Loudos, G.

    2015-09-01

    Commercial clinical and preclinical PET scanners rely on the full cylindrical geometry for whole body scans as well as for dedicated organs. In this study we propose the construction of a low cost dual-head C-shaped PET system dedicated for small animal brain imaging. Monte Carlo simulation studies were performed using GATE toolkit to evaluate the optimum design in terms of sensitivity, distortions in the FOV and spatial resolution. The PET model is based on SiPMs and BGO pixelated arrays. Four different configurations with C- angle 0°, 15°, 30° and 45° within the modules, were considered. Geometrical phantoms were used for the evaluation process. STIR software, extended by an efficient multi-threaded ray tracing technique, was used for the image reconstruction. The algorithm automatically adjusts the size of the FOV according to the shape of the detector's geometry. The results showed improvement in sensitivity of ∼15% in case of 45° C-angle compared to the 0° case. The spatial resolution was found 2 mm for 45° C-angle.

  8. [Interest of FDG-PET for lung cancer radiotherapy].

    PubMed

    Thureau, S; Mezzani-Saillard, S; Modzelewski, R; Edet-Sanson, A; Dubray, B; Vera, P

    2011-10-01

    The recent advances in medical imaging have profoundly altered the radiotherapy of non-small cell lung cancers (NSCLC). A meta-analysis has confirmed the superiority of FDG PET-CT over CT for initial staging. FDG PET-CT improves the reproducibility of target volume delineation, especially close to the mediastinum or in the presence of atelectasia. Although not formally validated by a randomized trial, the reduction of the mediastinal target volume, by restricting the irradiation to FDG-avid nodes, is widely accepted. The optimal method of delineation still remains to be defined. The role of FDG PET-CT in monitoring tumor response during radiotherapy is under investigation, potentially opening the way to adapting the treatment modalities to tumor radiation sensitivity. Other tracers, such as F-miso (hypoxia), are also under clinical investigation. To avoid excessive delays, the integration of PET-CT in routine practice requires quick access to the imaging equipment, technical support (fusion and image processing) and multidisciplinary delineation of target volumes. Copyright © 2011 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  9. A prototype PET/SPECT/X-rays scanner dedicated for whole body small animal studies.

    PubMed

    Rouchota, Maritina; Georgiou, Maria; Fysikopoulos, Eleftherios; Fragogeorgi, Eirini; Mikropoulos, Konstantinos; Papadimitroulas, Panagiotis; Kagadis, George; Loudos, George

    2017-01-01

    To present a prototype tri-modal imaging system, consisting of a single photon emission computed tomography (SPET), a positron emission tomography (PET), and a computed tomography (CT) subsystem, evaluated in planar mode. The subsystems are mounted on a rotating gantry, so as to be able to allow tomographic imaging in the future. The system, designed and constructed by our group, allows whole body mouse imaging of competent performance and is currently, to the best of our knowledge, unequaled in a national and regional level. The SPET camera is based on two Position Sensitive Photomultiplier Tubes (PSPMT), coupled to a pixilated Sodium Iodide activated with Thallium (NaI(Tl)) scintillator, having an active area of 5x10cm(2). The dual head PET camera is also based on two pairs of PSPMT, coupled to pixelated berillium germanium oxide (BGO) scintillators, having an active area of 5x10cm(2). The X-rays system consists of a micro focus X-rays tube and a complementary metal-oxide-semiconductor (CMOS) detector, having an active area of 12x12cm(2). The scintigraphic mode has a spatial resolution of 1.88mm full width at half maximum (FWHM) and a sensitivity of 107.5cpm/0.037MBq at the collimator surface. The coincidence PET mode has an average spatial resolution of 3.5mm (FWHM) and a peak sensitivity of 29.9cpm/0.037MBq. The X-rays spatial resolution is 3.5lp/mm and the contrast discrimination function value is lower than 2%. A compact tri-modal system was successfully built and evaluated for planar mode operation. The system has an efficient performance, allowing accurate and informative anatomical and functional imaging, as well as semi-quantitative results. Compared to other available systems, it provides a moderate but comparable performance, at a fraction of the cost and complexity. It is fully open, scalable and its main purpose is to support groups on a national and regional level and provide an open technological platform to study different detector components and

  10. Performance evaluation of the small-animal PET scanner ClairvivoPET using NEMA NU 4-2008 Standards

    NASA Astrophysics Data System (ADS)

    Sato, K.; Shidahara, M.; Watabe, H.; Watanuki, S.; Ishikawa, Y.; Arakawa, Y.; Nai, YH; Furumoto, S.; Tashiro, M.; Shoji, T.; Yanai, K.; Gonda, K.

    2016-01-01

    The aim of this study was to evaluate the performance of ClairvivoPET using NEMA NU4 standards. The ClairvivoPET incorporates a LYSO dual depth-of-interaction detector system with 151 mm axial field of view (FOV). Spatial resolution, sensitivity, counting rate capabilities, and image quality were evaluated using NEMA NU4-2008 standards. Normal mouse imaging was also performed for 10min after intravenous injection of 18F(-)-NaF. Data were compared with 19 other preclinical PET scanners. Spatial resolution measured using full width at half maximum on FBP-ramp reconstructed images was 2.16 mm at radial offset 5 mm of the axial centre FOV. The maximum absolute sensitivity for a point source at the FOV centre was 8.72%. Peak noise equivalent counting rate (NECR) was 415kcps at 14.6MBq ml-1. The uniformity with the image-quality phantom was 4.62%. Spillover ratios in the images of air and water filled chambers were 0.19 and 0.06, respectively. Our results were comparable with the 19 other preclinical PET scanners based on NEMA NU4 standards, with excellent sensitivity because of the large FOV. The ClairvivoPET with iterative reconstruction algorithm also provided sufficient visualization of the mouse spine. The high sensitivity and resolution of the ClairvivoPET scanner provided high quality images for preclinical studies.

  11. Evaluation of 18F-FDG uptake and arterial wall calcifications using 18F-FDG PET/CT.

    PubMed

    Ben-Haim, Simona; Kupzov, Ela; Tamir, Ada; Israel, Ora

    2004-11-01

    Glucose metabolic activity expressed as (18)F-FDG uptake may be increased in active atherosclerotic plaque. Calcium depositions are often increased in mature atherosclerotic plaque. The purpose of the present study was to assess the patterns of vascular-wall (18)F-FDG uptake and CT calcifications using combined PET/CT. One hundred twenty-two consecutive patients over the age of 50 (47 women and 75 men; mean age, 66 +/- 9 y) undergoing whole-body (18)F-FDG PET/CT for tumor assessment were retrospectively evaluated. PET, CT, and PET/CT slices were generated for review. Abnormal vascular findings in major arteries in the chest and abdomen were categorized as PET positive (PET+), PET negative (PET-), CT positive (CT+), or CT negative (CT-). The topographic relationship between increased vascular-wall (18)F-FDG uptake on PET and the presence of calcifications on CT was assessed on PET/CT fused images, with abnormal sites further classified as PET+/CT+, PET+/CT-, or PET-/CT+. The presence of CT calcifications and increased vascular-wall (18)F-FDG uptake was correlated with age, sex, presence of cardiovascular risk factors, and cardiovascular disease. Abnormal findings were identified at 349 sites. CT calcifications (CT+) were observed at 320 sites (92%) of 100 patients (82%), more commonly in men (P < 0.03), in older patients (P < 0.0001), in patients with hypertension (P < 0.003) or hyperlipidemia (P < 0.04), and in smokers (P < 0.008). Increased vascular-wall (18)F-FDG uptake (PET+) was observed at 52 sites (15%) of 38 patients (31%), more commonly in men (P < 0.02), in older patients (P < 0.0001), and in patients with hypertension (P < 0.02), and was borderline in patients with cardiovascular disease (P = 0.057). PET+ and CT+ findings correlated in 12 patients, a PET+/CT- pattern was found in 18 patients, and 8 patients had increased vascular-wall (18)F-FDG uptake in sites with and without calcifications (PET+/CT+, CT-). Twenty-two patients (18%) had a PET

  12. A sub-millimeter resolution detector module for small-animal PET applications

    NASA Astrophysics Data System (ADS)

    Sacco, I.; Dohle, R.; Fischer, P.; Gola, A.; Piemonte, C.; Ritzert, M.

    2017-01-01

    We present a gamma detection module optimized for very high resolution PET applications, able to resolve arrays of scintillating crystals with sub-millimeter pitch. The detector is composed of a single ceramic substrate (LTCC): it hosts four flip-chip mounted PETA5 ASICs on the bottom side and an array of SiPM sensors on the top surface, fabricated in HD-RGB technology by FBK. Each chip has 36 channels, for a maximum of 144 readout channels on a sensitive area of about 32 mm × 32 mm. The module is MR-compatible. The thermal decoupling of the readout electronics from the photon sensors is obtained with an efficient internal liquid channel, integrated within the ceramic substrate. Two modules have been designed, based on different SiPM topologies: • Light spreader-based: an array of 12 × 12 SiPMs, with an overall pitch of 2.5 mm, is coupled with a scintillators array using a 1 mm thick glass plate. The light from one crystal is spread over a group of SiPMs, which are read out in parallel using PETA5 internal neighbor logic. • Interpolating SiPM-based: ISiPMs are intrinsic position-sensitive sensors. The photon diodes in the array are connected to one of the four available outputs so that the center of gravity of any bunch of detected photons can be reconstructed using a proper weight function of the read out amplitudes. An array of ISiPMs, each 7.5 mm× 5 mm sized, is directly coupled with the scintillating crystals. Both modules can clearly resolve LYSO arrays with a pitch of only 0.833 mm. The detector can be adjusted for clinical PET, where it has already shown ToF resolution of about 230 ps CRT at FWHM. The module designs, their features and results are described.

  13. Normal variations and benign findings in pediatric 18F-FDG-PET/CT.

    PubMed

    Grant, Frederick D

    2014-04-01

    (18)F-FDG PET and PET/CT have a wide variety of indications in children and young adults. Oncologic indications are the most common, but others include neurology, sports medicine, cardiology, and infection imaging. Accurate interpretation of pediatric (18)F-FDG PET and PET/CT requires a technically adequate study and knowledgeable interpretation of the images. A successful pediatric (18)F-FDG PET requires age-appropriate patient preparation and consideration of patient age and developmental stage. Accurate interpretation of the study requires familiarity with normal patterns of physiologic (18)F-FDG uptake in children at all stages of development.

  14. Whole Body FDG-PET and FDG-PET/CT in Patients with Suspected Paraneoplastic Syndrome: A Systematic review and Meta-analysis of Diagnostic Accuracy.

    PubMed

    Sheikhbahaei, Sara; Marcus, Charles; Fragomeni, Roberto S; Rowe, Steven P; Javadi, Mehrbod S; Solnes, Lilja B

    2016-12-15

    The purpose of this study was to assess the diagnostic performance of whole body (18)F-FDG-PET or (18)F-FDG-PET/CT for detection of underlying malignancy in patients with clinically suspected neurological and non-neurological paraneoplastic syndromes.

  15. A feasibility study of PETiPIX: an ultra high resolution small animal PET scanner

    NASA Astrophysics Data System (ADS)

    Li, K.; Safavi-Naeini, M.; Franklin, D. R.; Petasecca, M.; Guatelli, S.; Rosenfeld, A. B.; Hutton, B. F.; Lerch, M. L. F.

    2013-12-01

    PETiPIX is an ultra high spatial resolution positron emission tomography (PET) scanner designed for imaging mice brains. Four Timepix pixellated silicon detector modules are placed in an edge-on configuration to form a scanner with a field of view (FoV) 15 mm in diameter. Each detector module consists of 256 × 256 pixels with dimensions of 55 × 55 × 300 μm3. Monte Carlo simulations using GEANT4 Application for Tomographic Emission (GATE) were performed to evaluate the feasibility of the PETiPIX design, including estimation of system sensitivity, angular dependence, spatial resolution (point source, hot and cold phantom studies) and evaluation of potential detector shield designs. Initial experimental work also established that scattered photons and recoil electrons could be detected using a single edge-on Timepix detector with a positron source. Simulation results estimate a spatial resolution of 0.26 mm full width at half maximum (FWHM) at the centre of FoV and 0.29 mm FWHM overall spatial resolution with sensitivity of 0.01%, and indicate that a 1.5 mm thick tungsten shield parallel to the detectors will absorb the majority of non-coplanar annihilation photons, significantly reducing the rates of randoms. Results from the simulated phantom studies demonstrate that PETiPIX is a promising design for studies demanding high resolution images of mice brains.

  16. Experimental Approach to Evaluate the 11C Perfusion and Diffusion in Small Animal Tissues for HadronPET Applications.

    PubMed

    Martínez-Rovira, Immaculada; Boisgard, Raphaël; Pottier, Géraldine; Kuhnast, Bertrand; Jan, Sébastien

    2016-01-01

    The development of a reliable dose monitoring system in hadron therapy is essential in order to control the treatment plan delivery. Positron Emission Tomography (PET) is the only method used in clinics nowadays for quality assurance. However, the accuracy of this method is limited by the loss of signal due to the biological washout processes. Up to the moment, very few studies measured the washout processes and there is no database of washout data as a function of the tissue and radioisotope. One of the main difficulties is related to the complexity of such measurements, along with the limited time slots available in hadron therapy facilities. Thus, in this work, we proposed an alternative in vivo methodology for the measurement and modeling of the biological washout parameters without any radiative devices. It consists in the implementation of a point-like radioisotope source by direct injection on the tissues of interest and its measurement by means of high-resolution preclinical PET systems. In particular, the washout of 11C carbonate radioisotopes was assessed, considering that 11C is is the most abundant β+ emitter produced by carbon beams. 11C washout measurements were performed in several tissues of interest (brain, muscle and 9L tumor xenograf) in rodents (Wistar rat). Results show that the methodology presented is sensitive to the washout variations depending on the selected tissue. Finally, a first qualitative correlation between 11C tumor washout properties and tumor metabolism (via 18F-FDG tracer uptake) was found.

  17. The role of FDG-PET in Hodgkin lymphoma

    PubMed Central

    Hałka, Janusz; Dziuk, Mirosław

    2017-01-01

    18-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) is currently the most valuable imaging technique in Hodgkin lymphoma. Since its first use in lymphomas in the 1990s, it has become the gold standard in the staging and end-of-treatment remission assessment in patients with Hodgkin lymphoma. The possibility of using early (interim) PET during first-line therapy to evaluate chemosensitivity and thus personalize treatment at this stage holds great promise, and much attention is now being directed toward this goal. With high probability, it is believed that in the near future, the result of interim PET-CT would serve as a compass to optimize treatment. Also the role of PET in pre-transplant assessment is currently evolving. Much controversy surrounds the possibility of detecting relapse after completed treatment with the use of PET in surveillance in the absence of symptoms suggestive of recurrence and the results of published studies are rather discouraging because of low positive predictive value. This review presents current knowledge about the role of 18-FDG-PET/CT imaging at each point of management of patients with Hodgkin lymphoma. PMID:28947879

  18. Staging recurrent ovarian cancer with 18FDG PET/CT

    PubMed Central

    DRAGOSAVAC, SANJA; DERCHAIN, SOPHIE; CASERTA, NELSON M.G.; DE SOUZA, GUSTAVO

    2013-01-01

    The aim of the present study was to evaluate the use of 2-deoxy-2-(18F)-fluoro-D-glucose (18FDG) positron emission tomography (PET)/computed tomography (CT) in patients with suspected ovarian cancer recurrence and describe the distribution of metastasis. A total of 45 female patients who underwent PET/CT scan due to raised CA-125 levels, clinical suspicion of ovarian cancer recurrence or alterations detected on ultrasound (US), CT or magnetic resonance imaging (MRI) were included in this retrospective study. PET/CT results were compared with histological findings (n=15) or clinical, laboratory and repeated imaging techniques during subsequent follow-up for at least six months (n=30). CA-125 was elevated in 34 patients, 14 patients had clinical symptoms of disease and 23 presented with alterations on US, CT and MRI. A total of 42 patients were confirmed to have ovarian cancer recurrence, all with abnormal findings on PET/CT. Three patients remained free of disease during clinical follow-up, all with normal PET/CT findings. There were 11 patients with raised CA-125 levels and normal conventional imaging, all with positive PET/CT. Among the 11 patients with normal CA-125 levels, eight presented with positive PET/CT scan. Lymph nodes were the most frequent site of relapse of disease, followed by peritoneal implants. Distant sites of metastasis included the liver, spleen, pleura, lung and bone. PET/CT detected unsuspected lesions in 20/45 patients (44.4%). 18FDG PET/CT was a useful tool for evaluating the extent of ovarian cancer recurrence. In the current series, lymph nodes were the most frequent site of relapse of disease, with supradiaphragmatic lymph node metastasis in a large number of cases. PMID:23420711

  19. 18F-FDG labeling of mesenchymal stem cells and multipotent adult progenitor cells for PET imaging: effects on ultrastructure and differentiation capacity.

    PubMed

    Wolfs, Esther; Struys, Tom; Notelaers, Tineke; Roberts, Scott J; Sohni, Abhishek; Bormans, Guy; Van Laere, Koen; Luyten, Frank P; Gheysens, Olivier; Lambrichts, Ivo; Verfaillie, Catherine M; Deroose, Christophe M

    2013-03-01

    Because of their extended differentiation capacity, stem cells have gained great interest in the field of regenerative medicine. For the development of therapeutic strategies, more knowledge on the in vivo fate of these cells has to be acquired. Therefore, stem cells can be labeled with radioactive tracer molecules such as (18)F-FDG, a positron-emitting glucose analog that is taken up and metabolically trapped by the cells. The aim of this study was to optimize the radioactive labeling of mesenchymal stem cells (MSCs) and multipotent adult progenitor cells (MAPCs) in vitro with (18)F-FDG and to investigate the potential radiotoxic effects of this labeling procedure with a range of techniques, including transmission electron microscopy (TEM). Mouse MSCs and rat MAPCs were used for (18)F-FDG uptake kinetics and tracer retention studies. Cell metabolic activity, proliferation, differentiation and ultrastructural changes after labeling were evaluated using an Alamar Blue reagent, doubling time calculations and quantitative TEM, respectively. Additionally, mice were injected with MSCs and MAPCs prelabeled with (18)F-FDG, and stem cell biodistribution was investigated using small-animal PET. The optimal incubation period for (18)F-FDG uptake was 60 min. Significant early tracer washout was observed, with approximately 30%-40% of the tracer being retained inside the cells 3 h after labeling. Cell viability, proliferation, and differentiation capacity were not severely affected by (18)F-FDG labeling. No major changes at the ultrastructural level, considering mitochondrial length, lysosome size, the number of lysosomes, the number of vacuoles, and the average rough endoplasmic reticulum width, were observed with TEM. Small-animal PET experiments with radiolabeled MAPCs and MSCs injected intravenously in mice showed a predominant accumulation in the lungs and a substantial elution of (18)F-FDG from the cells. MSCs and MAPCs can be successfully labeled with (18)F-FDG for

  20. Influence of FDG-PET on primary nodal target volume definition for head and neck carcinomas.

    PubMed

    van Egmond, Sylvia L; Piscaer, Vera; Janssen, Luuk M; Stegeman, Inge; Hobbelink, Monique G; Grolman, Wilko; Terhaard, Chris H

    The role of 2-[(18)F]-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in routine diagnostic staging remains controversial. In case of discordance between FDG-PET and CT, a compromise has to be made between the risk of false positive FDG-PET and the risk of delaying appropriate salvage intervention. Second, with intensity modulated radiation therapy (IMRT), smaller radiation fields allow tissue sparing, but could also lead to more marginal failures. We retrospectively studied 283 patients with head and neck carcinoma scheduled for radiotherapy between 2002 and 2010. We analyzed the influence of FDG-PET/CT versus CT alone on defining nodal target volume definition and evaluated its long-term clinical results. Second, the location of nodal recurrences was related to the radiation regional dose distribution. In 92 patients, CT and FDG-PET, performed in mold, showed discordant results. In 33%, nodal staging was altered by FDG-PET. In 24%, FDG-PET also led to an alteration in nodal treatment, including a nodal upstage of 18% and downstage of 6%. In eight of these 92 patients, a regional recurrence occurred. Only two patients had a recurrence in the discordant node on FDG-PET and CT and both received a boost (high dose radiation). These results support the complementary value of FDG-PET/CT compared to CT alone in defining nodal target volume definition for radiotherapy of head and neck cancer.

  1. Purulent lupus panniculitis unmasked by FDG-PET/CT scan

    PubMed Central

    van der Geest, Kornelis S.M.; Moerman, Rada V.; Koopmans, Klaas P.; Holman, Nicole D.; Janssen, Wilbert M.T.

    2016-01-01

    Abstract Rationale: Lupus panniculitis (LP) is a unique variant of cutaneous lupus erythematosus. Clinical manifestations are typically mild and include erythema, nodules, and small ulcers. In certain cases, diagnosing LP may be challenging. Skin overlying the typical subcutaneous inflammation may appear normal, and bacterial superinfections of the skin sometimes mask the underlying LP. It has been suggested that a computed tomography (CT) scan may help to identify obscure LP lesions. Here, we report a case of a 54-year-old woman with an unusually severe form of LP, in which the full disease extent was only revealed by a fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan. Patient concerns/Diagnoses/Interventions/Outcomes: Our patient initially presented with a bacterial infection of the skin. After initial improvement with antibiotic treatment, new erythematous lesions and sterile subcutaneous pus collections developed. An FDG-PET/CT scan revealed extensive subcutaneous inflammation at sites that had appeared normal during physical examination and on CT scan. As the subcutaneous lesions showed a remarkably linear pattern on FDG-PET/CT scan, the patient was suspected of having LP. After confirmation of this diagnosis by a deep-skin biopsy, our patient was treated with systemic glucocorticoids. Eventually, our patient succumbed to complications of LP and its treatment. Lessons: Our case demonstrates that clinical manifestations of LP are not always mild and that timely diagnosis is needed. Furthermore, we show that obscure LP lesions are more readily identified on an FDG-PET/CT scan than CT scan. PMID:27902603

  2. NEMA NU-04-based performance characteristics of the LabPET-8™ small animal PET scanner

    NASA Astrophysics Data System (ADS)

    Prasad, Rameshwar; Ratib, Osman; Zaidi, Habib

    2011-10-01

    The objective of this study is to characterize the performance of the preclinical avalanche photodiode (APD)-based LabPET-8™ subsystem of the fully integrated trimodality PET/SPECT/CT Triumph™ scanner using the National Electrical Manufacturers Association (NEMA) NU 04-2008 protocol. The characterized performance parameters include the spatial resolution, sensitivity, scatter fraction, counts rate performance and image-quality characteristics. The PET system is fully digital using APD-based detector modules with highly integrated electronics. The detector assembly consists of phoswich pairs of Lu1.9Y0.1SiO5 (LYSO) and Lu0.4Gd1.6SiO5 (LGSO) crystals with dimensions of 2 × 2 × 14 mm3 having 7.5 cm axial and 10 cm transverse field of view (FOV). The spatial resolution and sensitivity were measured using a small 22Na point source at different positions in the scanner's FOV. The scatter fraction and count rate characteristics were measured using mouse- and rat-sized phantoms fitted with an18F line source. The overall imaging capabilities of the scanner were assessed using the NEMA image-quality phantom and laboratory animal studies. The NEMA-based radial and tangential spatial resolution ranged from 1.7 mm at the center of the FOV to 2.59 mm at a radial offset of 2.5 cm and from 1.85 mm at the center of the FOV to 1.76 mm at a radial offset of 2.5 cm, respectively. Iterative reconstruction improved the spatial resolution to 0.84 mm at the center of the FOV. The total absolute system sensitivity is 12.74% for an energy window of 250-650 keV. For the mouse-sized phantom, the peak noise equivalent count rate (NECR) is 183 kcps at 2.07 MBq cc-1, whereas the peak true count rate is 320 kcps at 2.5 MBq cc-1 with a scatter fraction of 19%. The rat-sized phantom had a scatter fraction of 31%, with a peak NECR of 67 kcps at 0.23 MBq cc-1 and a peak true count rate of 186 kcps at 0.27 MBq cc-1. The average activity concentration and percentage standard deviation were 126

  3. A useful PET probe [(11)C]BU99008 with ultra-high specific radioactivity for small animal PET imaging of I2-imidazoline receptors in the hypothalamus.

    PubMed

    Kawamura, Kazunori; Shimoda, Yoko; Yui, Joji; Zhang, Yiding; Yamasaki, Tomoteru; Wakizaka, Hidekatsu; Hatori, Akiko; Xie, Lin; Kumata, Katsushi; Fujinaga, Masayuki; Ogawa, Masanao; Kurihara, Yusuke; Nengaki, Nobuki; Zhang, Ming-Rong

    2017-02-01

    A positron emission tomography (PET) probe with ultra-high specific radioactivity (SA) enables measuring high receptor specific binding in brain regions by avoiding mass effect of the PET probe itself. It has been reported that PET probe with ultra-high SA can detect small change caused by endogenous or exogenous ligand. Recently, Kealey et al. developed [(11)C]BU99008, a more potent PET probe for I2-imidazoline receptors (I2Rs) imaging, with a conventional SA (mean 76GBq/μmol) showed higher specific binding in the brain. Here, to detect small change of specific binding for I2Rs caused by endogenous or exogenous ligand in an extremely small region, such as hypothalamus in the brain, we synthesized and evaluated [(11)C]BU99008 with ultra-high SA as a useful PET probe for small-animal PET imaging of I2Rs. [(11)C]BU99008 was prepared by [(11)C]methylation of N-desmethyl precursor with [(11)C]methyl iodide. Biodistribution, metabolite analysis, and brain PET studies were conducted in rats. [(11)C]BU99008 with ultra-high SA in the range of 5400-16,600GBq/μmol were successfully synthesized (n=7), and had appropriate radioactivity for in vivo study. In the biodistribution study, the mean radioactivity levels in all investigated tissues except for the kidney did not show significant difference between [(11)C]BU99008 with ultra-high SA and that with conventional SA. In the metabolite analysis, the percentage of unchanged [(11)C]BU99008 at 30min after the injection of probes with ultra-high and conventional SA was similar in rat brain and plasma. In the PET study of rats' brain, radioactivity level (AUC30-60 min) in the hypothalamus of rats injected with [(11)C]BU99008 with ultra-high SA (64 [SUV ∙ min]) was significantly higher than that observed for that with conventional SA (50 [SUV ∙ min]). The specific binding of [(11)C]BU99008 with ultra-high SA (86% of total binding) for I2R was higher than that of conventional SA (76% of total binding). A PET study using [(11)C

  4. First Results From a High-Resolution Small Animal SiPM PET Insert for PET/MR Imaging at 7T

    NASA Astrophysics Data System (ADS)

    Goertzen, Andrew L.; Stortz, Greg; Thiessen, Jonathan D.; Bishop, Daryl; Khan, Muhammad Salman; Kozlowski, Piotr; Retière, Fabrice; Schellenberg, Graham; Shams, Ehsan; Sossi, Vesna; Thompson, Christopher J.

    2016-10-01

    We present the initial results from a small animal PET insert designed to be operated inside a 7T MRI. The insert fits within the 114 mm inner diameter of the Bruker BGA-12S gradient coil while accommodating the Bruker 35 mm volume RF coil (outer diameter 60 mm), both used in the Bruker 70/20 MRI systems. The PET insert is a ring comprising 16 detectors. Each detector has a dual-layer offset (DLO) lutetium-yttrium oxyorthsilicate (LYSO) scintillator array read out by two SensL SPMArray4B SiPM arrays. The DLO scintillator has bottom (top) layers of: 22 × 10 (21 × 9) crystals of size 1.2 × 1.2 × 6 (4) mm3 for a total of 409 crystals per block, providing an axial extent of 28.17 mm. The detector outputs are multiplexed to four signals using a custom readout board and digitized using the OpenPET data acquisition platform. The detector flood images successfully resolve over 99% of the crystals, with average energy resolution of 12.5 ± 2.0% at 511 keV. Testing of the PET system inside the MRI showed that the PET insert had no effect on MRI image homogeneity and only a small effect on echo planar images (EPI) signal to noise ratio (SNR) (-9%), with neither PET nor MRI images showing obvious artefacts. These acquisitions used the OpenPET operating in “oscilloscope mode” with USB2.0 interface, allowing a maximum total singles event rate of 280 kcps, strongly limiting the count rate capabilities of the system. The PET radial spatial resolution (as measured with a 22Na point source and FBP-3DRP reconstruction) is 1.17 mm at the centre, degrading to 1.86 mm at a 15 mm radial offset. Simultaneous phantom and mouse PET/MR imaging produced good quality images that were free of any obvious artefacts.

  5. Supraclavicular lymph nodes detected by 18F-FDG PET/CT in cancer patients: assessment with 18F-FDG PET/CT and sonography.

    PubMed

    Lee, Jae-hoon; Kim, Jinna; Moon, Hee Jung; Cho, Arthur; Yun, Mijin; Lee, Jong Doo; Kang, Won Jun

    2012-01-01

    The purposes of this study were to assess the diagnostic accuracy of 18F-FDG PET (FDG PET) for the detection of metastatic supraclavicular lymph nodes (LNs) and to propose an optimal diagnostic strategy with additional sonography, contrast-enhanced CT (CECT), or both. One hundred supraclavicular LNs initially detected using FDG PET were examined using sonography. Regardless of the imaging findings, all 100 supraclavicular LNs underwent sonography-guided fine-needle aspiration biopsy. The maximum standardized uptake values (SUVsmax) of the supraclavicular LNs were measured, and a receiver operating characteristic (ROC) analysis was performed to determine the cutoff SUVmax. Then we evaluated the diagnostic performance of FDG PET and figured out the optimal combination of FDG PET and sonography or CECT to improve the diagnostic accuracy of the imaging studies and minimize procedures. In total, 86 of 100 PET-detected supraclavicular LNs were malignant. With application of the cutoff value obtained by ROC analysis (SUVmax=3.0), the diagnostic accuracy of FDG PET was 75.0% with a sensitivity of 74.4% and specificity of 78.6%. For supraclavicular LNs with an SUVmax of more than 3.0, FDG PET showed a positive predictive value of 95.5%; for supraclavicular LNs with an SUVmax of 3.0 or less, sonography excluded all false-negative FDG PET cases and showed a high negative predictive value of 100%. When sonography was selectively applied to cases with an SUVmax of 3.0 or less, the overall diagnostic accuracy increased to 92%. Our study revealed a high incidence rate of metastasis in PET-detected supraclavicular LNs in cancer patients. We believe that our proposed diagnostic workflow could decrease unnecessary diagnostic procedures in the evaluation of PET-positive supraclavicular LNs in cancer patients with reliability.

  6. Characteristics of a multichannel low-noise front-end ASIC for CZT-based small animal PET imaging

    NASA Astrophysics Data System (ADS)

    Gao, W.; Liu, H.; Gan, B.; Hu, Y.

    2014-05-01

    In this paper, we present the design and characteristics of a novel low-noise front-end readout application-specific integrated circuit dedicated to CdZnTe (CZT) detectors for a small animal PET imaging system. A low-noise readout method based on the charge integration and the delayed peak detection is proposed. An eight-channel front-end readout prototype chip is designed and implemented in a 0.35 μm CMOS process. The die size is 2.3 mm ×2.3 mm. The prototype chip is tested in different methods including electronic test, energy spectrum test and irradiation test. The input range of the ASIC is from 2000e- to 180,000e-, reflecting the energy of the gamma ray from 11.2 keV to 1 MeV. The gain of the readout channel is 65 mV/fC at the shaping time of 1 μs. The best test result of the equivalent noise charge (ENC) is 58.9 e- at zero farad plus 5.4 e- per picofarad. The nonlinearity and the crosstalk are less than 3% and less than 2%, respectively, at the room temperature. The static power dissipation is about 3 mW/channel.

  7. A true singles list-mode data acquisition system for a small animal PET scanner with independent crystal readout.

    PubMed

    McElroy, D P; Hoose, M; Pimpl, W; Spanoudaki, V; Schüler, T; Ziegler, S I

    2005-07-21

    We present a unique data acquisition system designed to read out signals from the MADPET-II small animal LSO-APD PET tomograph. The scanner consists of 36 independent detector modules arranged in a dual-radial layer ring (phi 71 mm). Each module contains a 4 x 8 array of optically isolated, 2 x 2 mm LSO crystals, coupled one-to-one to a 32 channel APD. To take full advantage of the detector geometry, signals from each crystal are individually processed without any data reduction. This is realized using custom designed mixed-signal ASICs for analogue signal processing, and FPGAs to control the digitization of analogue signals and subsequent multiplexing. Analogue to digital converters (ADCs) digitize the signal peak height, time to digital converters (TDCs) time stamp each event relative to a system clock and two 32 bit words containing the energy, time and position information for each singles event are multiplexed through three FIFO stages before being written to disk via gigabit Ethernet. Every singles event is processed and stored in list-mode format, and coincidences are sorted post-acquisition in software. The 1152 channel data acquisition system was designed to be able to handle sustained data rates of up to 11 520 000 cps without loss (10 000 cps/channel). The timing resolution of the TDC was measured to be 1 ns FWHM. In addition to describing the data acquisition system, performance measurements made using a 128-channel detector prototype will be presented.

  8. A true singles list-mode data acquisition system for a small animal PET scanner with independent crystal readout

    NASA Astrophysics Data System (ADS)

    McElroy, D. P.; Hoose, M.; Pimpl, W.; Spanoudaki, V.; Schüler, T.; Ziegler, S. I.

    2005-07-01

    We present a unique data acquisition system designed to read out signals from the MADPET-II small animal LSO-APD PET tomograph. The scanner consists of 36 independent detector modules arranged in a dual-radial layer ring (∅ 71 mm). Each module contains a 4 × 8 array of optically isolated, 2 × 2 mm LSO crystals, coupled one-to-one to a 32 channel APD. To take full advantage of the detector geometry, signals from each crystal are individually processed without any data reduction. This is realized using custom designed mixed-signal ASICs for analogue signal processing, and FPGAs to control the digitization of analogue signals and subsequent multiplexing. Analogue to digital converters (ADCs) digitize the signal peak height, time to digital converters (TDCs) time stamp each event relative to a system clock and two 32 bit words containing the energy, time and position information for each singles event are multiplexed through three FIFO stages before being written to disk via gigabit Ethernet. Every singles event is processed and stored in list-mode format, and coincidences are sorted post-acquisition in software. The 1152 channel data acquisition system was designed to be able to handle sustained data rates of up to 11 520 000 cps without loss (10 000 cps/channel). The timing resolution of the TDC was measured to be 1 ns FWHM. In addition to describing the data acquisition system, performance measurements made using a 128-channel detector prototype will be presented.

  9. Performance evaluation of a rotatory dual-head PET system with 90o increments for small animal imaging

    NASA Astrophysics Data System (ADS)

    Meng, F.; Zhu, S.; Li, L.; Wang, J.; Cao, X.; Cao, X.; Chen, X.; Liang, J.

    2017-09-01

    A rotatory dual-head positron emission tomography (PET) system with 90o increments has been built up by our lab. In this study, a geometric calibration phantom was designed and then used to calibrate the geometric offset of the system. With the geometric calibration, the artifacts in the reconstructed images were greatly eliminated. Then, we measured the imaging performance including resolution, sensitivity and image quality. The results showed that the full width at half maximum (FWHMs) of the point source were about 1.1 mm in three directions. The peak absolute sensitivity in the center of the field of view varied from 5.66% to 3.17% when the time window was fixed to 10 ns and the energy window was changed from 200-800 keV to 350–650 keV. The recovery coefficients ranged from 0.13 with a standard deviation of 17.5% to 0.98 with a standard deviation of 15.76%. For the air-filled and water-filled chamber, the spill-over ratio was 14.48% and 15.38%, respectively. The in vivo mouse experiment was carried out and further demonstrated the potential of our system in small animal studies.

  10. Accuracy of FDG-PET to diagnose lung cancer in a region of endemic granulomatous disease.

    PubMed

    Deppen, Stephen; Putnam, Joe B; Andrade, Gabriela; Speroff, Theodore; Nesbitt, Jonathan C; Lambright, Eric S; Massion, Pierre P; Walker, Ron; Grogan, Eric L

    2011-08-01

    The 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) is used to evaluate suspicious pulmonary lesions due to its diagnostic accuracy. The southeastern United States has a high prevalence of infectious granulomatous lung disease, and the accuracy of FDG-PET may be reduced in this population. We examined the diagnostic accuracy of FDG-PET in patients with known or suspected non-small cell lung cancer treated at our institution. A total of 279 patients, identified through our prospective database, underwent an operation for known or suspected lung cancer. Preoperative FDG-PET in 211 eligible patients was defined by standardized uptake value greater than 2.5 or by description ("moderate" or "intense") as avid. Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and decision diagrams were calculated for FDG-PET in all patients and in patients with indeterminate nodules. In all eligible patients (n=211), sensitivity and specificity of FDG-PET were 92% and 40%, respectively. Positive and negative predictive values were 86% and 55%. Overall FDG-PET accuracy to diagnose lung cancer was 81%. Preoperative positive likelihood ratio for FDG-PET diagnosis of lung cancer in this population was 1.5 compared with previously published values of 7.1. In 113 indeterminate lesions, 65% had lung cancer and the sensitivity and specificity were 89% and 40%, respectively. Twenty-four benign nodules (60%) had false positive FDG-PET scans. Twenty-two of 43 benign nodules (51%) were granulomas. In a region with endemic granulomatous diseases, the specificity of FDG-PET for diagnosis of lung cancer was 40%. Clinical decisions and future clinical predictive models for lung cancer must accommodate regional variation of FDG-PET scan results. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Clinical significance of FDG-PET/CT at the postoperative surveillance in the breast cancer patients.

    PubMed

    Jung, Na Young; Yoo, Ie Ryung; Kang, Bong Joo; Kim, Sung Hun; Chae, Byung Joo; Seo, Ye Young

    2016-01-01

    We evaluated the clinical role of [(18)F]-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) compared with conventional imaging (CI) to detect locoregional recurrence or distant metastasis during postoperative surveillance of patients with breast cancer. We included 1,819 examinations of 1,161 patients, who underwent FDG-PET/CT and CI, including mammography, breast ultrasound, whole-body bone scintigraphy, and chest radiography for postoperative surveillance. All patients had a history of surgery with or without adjuvant treatment due to more than stage II breast cancer between November 2003 and November 2009. We evaluated the diagnostic performance of CI, FDG-PET/CT, and combined CI and FDG-PET/CT for detecting locoregional recurrence, distant metastasis, and incidental cancer. We also analyzed false-positive and false-negative results in both FDG-PET/CT and CI. Sensitivity, specificity, positive predictive value, and negative predictive value of CI were 75.4, 98.7, 93.4, and 94.3 %. Those of FDG-PET/CT were 97.5, 98.8, 95.4, and 99.4 %. Those of the combined results were 98.6, 98.2, 96.7, and 99.7 %. Sensitivity of FDG-PET/CT was significantly higher than that of CI (P < 0.05). Sensitivity of combined CI and FDG-PET/CT results improved, but they were not significantly different from those of FDG-PET/CT alone (P = 0.43). Seventeen false-positive and nine false-negative cases were detected with FDG-PET/CT, and 19 false-positive and 88 false-negative cases were detected with CI. FDG-PET/CT is considered as an acceptable diagnostic imaging modality for postoperative surveillance of patients with breast cancer.

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

    PubMed

    Ito, Shin; Yokoyama, Junkichi; Yoshimoto, Hitoshi; Yazawa, Masaki; Kazuo, Kubota; Hanaguri, Makoto; Ohba, Shinichi; Fujimaki, Mitsuhisa; Ikeda, Katsuhisa

    2012-02-07

    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. 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. 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. We emphasize the usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base after various treatments, compared with FDG-PET.

  13. FDG PET/CT appearance of local osteosarcoma recurrences in pediatric patients.

    PubMed

    Sharp, Susan E; Shulkin, Barry L; Gelfand, Michael J; McCarville, M Beth

    2017-09-08

    Osteosarcoma is the most common pediatric malignant bone tumor, frequently surgically managed with limb salvage rather than amputation. Local recurrences are seen in up to 9% of osteosarcoma patients, with CT and MRI imaging often limited by metal artifacts. To describe the [F-18]2-fluoro-2-deoxyglucose (FDG) PET/CT appearance of local osteosarcoma recurrences with correlation to findings on other imaging modalities. A retrospective review of pediatric osteosarcoma patients imaged with FDG PET/CT was performed in patients with pathologically proven local recurrences. FDG PET/CT findings were reviewed and correlated with available comparison imaging studies. Ten local osteosarcoma recurrences in eight pediatric osteosarcoma patients were imaged with FDG PET/CT. All eight patients had a local recurrence after limb salvage; two patients had a second local recurrence after amputation. All local recurrences were seen with FDG PET/CT, demonstrating solid (n=5) or peripheral/nodular (n=5) FDG uptake patterns. Maximum standard uptake values (SUVs) ranged from 3.0 to 15.7. In five recurrences imaged with FDG PET/CT and MRI, MRI was limited or nondiagnostic in three. In four recurrences imaged with FDG PET/CT and bone scan, the bone scan was negative in three. Local osteosarcoma recurrences are well visualized by FDG PET/CT, demonstrating either solid or peripheral/nodular FDG uptake with a wide range of maximum SUVs. FDG PET/CT demonstrates the full extent of local recurrences, while MRI can be limited by artifact from metallic hardware. PET/CT appears to be more sensitive than bone scan in detecting local osteosarcoma recurrences.

  14. Derivation of input function from FDG-PET studies in small hearts

    SciTech Connect

    Wu, Hsiao-Ming; Huang, Sung-Cheng; Allada, V.

    1996-10-01

    The extraction of pure arterial time-activity curves (TACs) from dynamic PET images of a small animal heart using factor analysis of dynamic structures (FADS) was found to be unsuccessful due to the small size of the cardiac chamber that causes extensive mixture of TACs of different structures. In this study, we used digital phantoms of the left ventricle (LV cavity size: 1-2 cm) and small monkey (LV cavity size: {approx} 2 cm) dynamic FDG PET studies to evaluate FADS for extracting the pure blood-pool TACs by adding a single blood sample (taken at a late scan time) constraint. In the digital phantom studies, spillover fractions in the extracted blood-pool TACs using FADS without a blood sample constraint (FADS(-)) and with a blood sample constraint (FADS(+)) were 3%-91% and < 3%, respectively. In the monkey studies (n = 4), FADS(+) extracted blood-pool TACs matched well with the arterialized well counter measurements (% differences of curve integration: FADS(-) < 82%; FADS(+) < 9%). The microparameters (K*{sub 1}, k*{sub 2}, k*{sub 3}, k*{sub 4}) and macroparameters (K{sub nlr}), obtained from the FADS(+) blood-pool TACs, were similar to those obtained from plasma samples in a three-compartment model fitting (% differences of K{sub nlr}: phantom studies < 5%; monkey studies < 9%). The FADS technique with a single-blood sample has the potential to extract the pure blood-pool TACs directly from dynamic PET images of a small animal without multiple blood sampling, region of interest definition or spillover correction. 14 refs., 5 figs., 3 tabs.

  15. Beyond the lymph nodes: FDG-PET/CT in primary extranodal lymphoma.

    PubMed

    Sin, Kin Man; Ho, Stanton King Dat; Wong, Brian Yung Kong; Gill, Harry; Khong, Pek-Lan; Lee, Elaine Yuen Phin

    Extranodal lymphoma can be the primary presentation or secondary to systemic involvement of lymphoma. 2-(fluorine-18) fluoro-2-deoxy-d-glucose positron emission tomography with computer tomography (FDG-PET/CT) is useful in detecting extranodal sites during staging, treatment response assessment or recurrence detection in patients with lymphoma. In this article, we reviewed the imaging features and FDG avidity of primary extranodal lymphoma of various organs and systems on FDG-PET/CT, demonstrating the pearls and pitfalls of FDG-PET/CT in evaluating this disease entity and cross-referencing to other imaging modalities that aid in diagnosis and management. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. FDG-PET findings in the Wernicke-Korsakoff syndrome.

    PubMed

    Reed, Laurence J; Lasserson, Dan; Marsden, Paul; Stanhope, Nicola; Stevens, Tom; Bello, Fernando; Kingsley, Derek; Colchester, Alan; Kopelman, Michael D

    2003-01-01

    This study reports FDG-PET findings in Wernicke-Korsakoff patients. Twelve patients suffering amnesia arising from the Korsakoff syndrome were compared with 10 control subjects without alcohol-related disability. Subjects received [18F]-fluorodeoxyglucose (FDG-PET) imaging as well as neuropsychological assessment and high-resolution MR imaging with volumetric analysis. Volumetric MRI analysis had revealed thalamic and mamillary body atrophy in the patient group as well as frontal lobe atrophy with relative sparing of medial temporal lobe structures. Differences in regional metabolism were identified using complementary region of interest (ROI) and statistical parametric mapping (SPM) approaches employing either absolute methods or a reference region approach to increase statistical power. In general, we found relative hypermetabolism in white matter and hypometabolism in subcortical grey matter in Korsakoff patients. When FDG uptake ratios were examined with occipital lobe metabolism as covariate reference region, Korsakoff patients showed widespread bilateral white matter hypermetabolism on both SPM and ROI analysis. When white matter metabolism was the reference covariate; Korsakoff patients showed relative hypometabolism in the diencephalic grey matter, consistent with their known underlying neuropathology, and medial temporal and retrosplenial hypometabolism, interpreted as secondary metabolic effects within the diencephalic-limbic memory circuits. There was also evidence of a variable degree of more general frontotemporal neocortical hypometabolism on some, but not all, analyses.

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

    PubMed Central

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

    2015-01-01

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

  18. A Small-Animal PET System Based on LYSO Crystal Arrays, PS-PMTs and a PCI DAQ Board

    NASA Astrophysics Data System (ADS)

    Alva-Sanchez, H.; Murrieta, T.; Moreno-Barbosa, E.; Brandan, M. E.; Ruiz-Trejo, C.; Martinez-Davalos, A.; Rodriguez-Villafuerte, M.

    2010-02-01

    A positron emission tomography system for small animals has been designed for research purposes, and developed at Instituto de Fi¿sica, UNAM, Mexico. Its detection modules are based on pixelated scintillator LYSO crystal arrays coupled to Hamamatsu H8500 position-sensitive photomultiplier tubes. The front-end electronics are based on nuclear instrumentation modules (NIM) and in-house built readout circuits. Peak signal digitization is performed with a commercial analogue-to-digital acquisition (DAQ) board. The system has been characterized for spatial, timing and energy resolution, system dead time, absolute sensitivity, scatter fraction and noise equivalent count rate (NEC). The results indicate that the detection modules are able to identify individual crystals (out of 400) with up to 8-to-1 peak-to-valley ratios with individual crystal energy resolution ranging from 7 to 15% at 511 keV. The timing resolution is 1.9 ns and the system dead time was found to be 16.8 ¿s and 42.1 ¿s for 0.5 ml and 10 ml volume sources, respectively. The measured absolute system sensitivity is 0.11% and the scatter fraction from a glass capillary inside a 2.5 cm diameter mouse phantom is 21.5%. A true NEC maximum value was not achieved with the system due to saturation of the PS-PMT output signals for activities above 0.27 mCi. Results from a Na18 F PET bone scan of a 30 g mouse are shown.

  19. IMOTEPAD: A mixed-signal 64-channel front-end ASIC for small-animal PET imaging

    NASA Astrophysics Data System (ADS)

    Fang, Xiaochao; Ollivier-Henry, Nicolas; Gao, Wu; Hu-Guo, Christine; Colledani, Claude; Humbert, Bernard; Brasse, David; Hu, Yann

    2011-04-01

    This paper presents the design and characteristics of a mixed-signal 64-channel front-end readout ASIC called IMOTEPAD dedicated to multi-channel plate (MCP) photodetector coupled to LYSO scintillating crystals for small-animal PET imaging. In our configuration, the crystals are oriented in the axial direction readout on both sides by individual photodetector channels allowing the spatial resolution and the detection efficiency to be independent of each other. As a result, both energy signals and timing triggers from the photodetectors are required to be read out by the front-end ASIC. This dedicated ASIC IMOTEPAD comprises two parts: the analog part IMOTEPA and the digital part IMOTEPD. The IMOTEPA is dedicated to energy measurement. And the timing information is digitized by the IMOTEPD in which the key principal element is a time-to-digital converter (TDC) based on a delay-locked loop (DLL) with 32 delay cells. The chip is designed and fabricated in 0.35 μm CMOS process. The measurements show that for the analog part IMOTEPA, the energy gain is 13.1 mV/pC while the peak time of a CR-RC pulse shaper is 280 ns. The SNR is 39 dB and the RMS noise is 300 μV. The nonlinearity is less than 3%. The crosstalk is less than 0.2%. For the IMOTEPD, the bin size of the TDC is 625 ps with a reference clock of 50 MHz. The RMS jitter of the DLL is less than 42 ps. The DNL of the TDC is equal to about 0.17 LSB and the INL is equal to 0.31 LSB. The power dissipation of each channel is less than 16.8 mW. The design of the ASIC, especially for TDC and the measurement results of the IMOTEPAD will be presented and discussed in this paper.

  20. The distribution of D2/D3 receptor binding in the adolescent rhesus monkey using small animal PET imaging

    PubMed Central

    Christian, BT; Vandehey, NT; Fox, AS; Murali, D; Oakes, TR; Converse, AK; Nickles, RJ; Shelton, SE; Davidson, RJ; Kalin, NH

    2009-01-01

    PET imaging of the neuroreceptor systems in the brain has earned a prominent role in studying normal development, neuropsychiatric illness and developing targeted drugs. The dopaminergic system is of particular interest due to its role in the development of cognitive function and mood as well as its suspected involvement in neuropsychiatric illness. Nonhuman primate animal models provide a valuable resource for relating neurochemical changes to behavior. To facilitate comparison within and between primate models, we report in vivo D2/D3 binding in a large cohort of adolescent rhesus monkeys. Methods In this work, the in vivo D2/D3 dopamine receptor availability was measured in a cohort of 33 rhesus monkeys in the adolescent stage of development (3.2 – 5.3 years). Both striatal and extrastriatal D2/D3 binding were measured using [F-18]fallypride with a high resolution small animal PET scanner. The distribution volume ratio (DVR) was measured for all subjects and group comparisons of D2/D3 binding among the cohort were made based on age and sex. Because two sequential studies were acquired from a single [F-18]fallypride batch, the effect of competing (unlabeled) ligand mass was also investigated. Results Among this cohort, the rank order of regional D2/D3 receptor binding did not vary from previous studies with adult rhesus monkeys, with: putamen > caudate > ventral striatum > amygdala ~ substantia nigra > medial dorsal thalamus > lateral temporal cortex ~ frontal cortex. The DVR coefficient of variation ranged from 14% – 26%, with the greatest variance seen in the head of the caudate. There were significant sex differences in [F-18]fallypride kinetics in the pituitary gland, but this was not observed for regions within the blood-brain barrier. Furthermore, no regions in the brain showed significant sex or age related differences in DVR within this small age range. Based on a wide range of injected fallypride mass across the cohort, significant competition

  1. Incidental Detection of Femoral Pseudoaneurysm at 18F-FDG PET/CT

    PubMed Central

    Nougaret, Stephanie; Ragucci, Monica; Bach, Ariadne M.; Carollo, Gabriella; Mannelli, Lorenzo

    2016-01-01

    A 72-year-old man with history of lung cancer and melanoma was referred for routine follow-up with 18F-FDG PET/CT. CT images showed a new mass in the right groin associated with mild FDG activity on 18F-FDG PET images. Subsequent ultrasound obtained the same day demonstrated flow within the lesion to be a pseudoaneurysm of the right femoral artery. PMID:26462043

  2. A simple device to convert a small-animal PET scanner into a multi-sample tissue and injection syringe counter.

    PubMed

    Green, Michael V; Seidel, Jurgen; Choyke, Peter L; Jagoda, Elaine M

    2017-10-01

    We describe a simple fixture that can be added to the imaging bed of a small-animal PET scanner that allows for automated counting of multiple organ or tissue samples from mouse-sized animals and counting of injection syringes prior to administration of the radiotracer. The combination of imaging and counting capabilities in the same machine offers advantages in certain experimental settings. A polyethylene block of plastic, sculpted to mate with the animal imaging bed of a small-animal PET scanner, is machined to receive twelve 5-ml containers, each capable of holding an entire organ from a mouse-sized animal. In addition, a triangular cross-section slot is machined down the centerline of the block to secure injection syringes from 1-ml to 3-ml in size. The sample holder is scanned in PET whole-body mode to image all samples or in one bed position to image a filled injection syringe. Total radioactivity in each sample or syringe is determined from the reconstructed images of these objects using volume re-projection of the coronal images and a single region-of-interest for each. We tested the accuracy of this method by comparing PET estimates of sample and syringe activity with well counter and dose calibrator estimates of these same activities. PET and well counting of the same samples gave near identical results (in MBq, R(2)=0.99, slope=0.99, intercept=0.00-MBq). PET syringe and dose calibrator measurements of syringe activity in MBq were also similar (R(2)=0.99, slope=0.99, intercept=- 0.22-MBq). A small-animal PET scanner can be easily converted into a multi-sample and syringe counting device by the addition of a sample block constructed for that purpose. This capability, combined with live animal imaging, can improve efficiency and flexibility in certain experimental settings. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. FDG-MicroPET and Diffusion-Weighted MR Image Evaluation of Early Changes After Radiofrequency Ablation in Implanted VX2 Tumors in Rabbits

    SciTech Connect

    Ohira, Tomohiro Okuma, Tomohisa; Matsuoka, Toshiyuki; Wada, Yasuhiro; Nakamura, Kenji; Watanabe, Yasuyoshi; Inoue, Yuichi

    2009-01-15

    The objective of this study was to evaluate the early changes after radiofrequency ablation (RFA) in VX2 rabbit tumors implanted into the back muscles by diffusion-weighted magnetic resonance (MR) imaging and {sup 18}F-2-fluoro-2-deoxy-D-glucose positron emission tomography ({sup 18}F-FDG PET). Percutaneous CT-guided RFA was conducted in seven rabbits with implanted VX2 tumors. VX2 tumors on the other side were untreated and served as the control. MR imaging was performed with a clinical 1.5-T instrument 2 days after RFA, and FDG-PET, using a high-resolution PET scanner for small animals, was obtained 3 days after the procedure. The mean apparent diffusion coefficient (ADC) values and radioactivity count of untreated and ablated tumors were calculated. Untreated VX2 tumors showed hyperintensity on T1-, T2-, and diffusion-weighted MR images, ring-enhanced on contrast-enhanced T1-weighted imaging, and ring-shaped FDG accumulation on FDG-PET. Ablated VX2 tumors showed slight hyperintensity on T1-, T2-, and diffusion-weighed images, slight enhancement on contrast-enhanced T1-weighted images, and low accumulation on FDG-PET. The ADC value of ablated VX2 tumors (1.52 {+-} 0.24 x 10{sup -3} mm{sup 2}/s) was significantly higher than that of untreated tumors (1.09 {+-} 0.12 x 10{sup -3}; p < 0.05). The tumor/muscle ratio of ablated tumors (0.5 {+-} 0.3) was significantly lower than that of untreated tumors (11.6 {+-} 3.2; p < 0.05). Histopathological examination confirmed the lack of viable tumor cells in the ablated lesions. The results indicate that both ADC value and FDG-PET are potentially useful markers for monitoring the early effects of RFA.

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

    NASA Astrophysics Data System (ADS)

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

    2008-03-01

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

  5. Accuracy of FDG-PET to diagnose lung cancer in a region of endemic granulomatous disease

    PubMed Central

    Deppen, Stephen; Putnam, Joe B.; Andrade, Gabriela; Speroff, Theodore; Nesbitt, Jonathan C.; Lambright, Eric S.; Massion, Pierre P.; Walker, Ron; Grogan, Eric L.

    2011-01-01

    Background 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) is used to evaluate suspicious pulmonary lesions due to its diagnostic accuracy. The southeastern United States has a high prevalence of infectious granulomatous lung disease, and the accuracy of FDGPET may be reduced in this population. We examined the diagnostic accuracy of FDG-PET in patients with known or suspected NSCLC treated at our institution. Methods 279 patients identified through our prospective database, underwent an operation for known or suspected lung cancer. Preoperative FDG-PET in 211 eligible patients was defined by standardized uptake value, SUV > 2.5 or by description (“moderate” or “intense”) as avid. Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and decision diagrams were calculated for FDG-PET in all patients and in patients with indeterminate nodules. Results In all eligible patients (n=211), sensitivity and specificity of FDG-PET were 92% and 40%. Positive and negative predictive values were 86% and 55%. Overall FDG-PET accuracy to diagnose lung cancer was 81%. Preoperative positive likelihood ratio for FDG-PET diagnosis of lung cancer in this population was 1.5 compared to previously published values of 7.1. In 113 indeterminate lesions, 65% had lung cancer and the sensitivity and specificity were 89% and 40% respectively. 24 benign nodules (60%) had false positive FDG-PET scans. 22 of 43 benign nodules (51%) were granulomas. Conclusions In a region with endemic granulomatous diseases, the specificity of FDG-PET for diagnosis of lung cancer was 40%. Clinical decisions and future clinical predictive models for lung cancer must accommodate regional variation of FDG-PET scan results. PMID:21592456

  6. Concordance between brain (18)F-FDG PET and cerebrospinal fluid biomarkers in diagnosing Alzheimer's disease.

    PubMed

    Rubí, S; Noguera, A; Tarongí, S; Oporto, M; García, A; Vico, H; Espino, A; Picado, M J; Mas, A; Peña, C; Amer, G

    2017-06-20

    Cortical posterior hypometabolism on PET imaging with (18)F-FDG (FDG-PET), and altered levels of Aß1-42 peptide, total Tau (tTau) and phosphorylated Tau (pTau) proteins in cerebrospinal fluid (CSF) are established diagnostic biomarkers in Alzheimer's disease (AD). An evaluation has been made of the concordance and relationship between the results of FDG-PET and CSF biomarkers in symptomatic patients with suspected AD. A retrospective review was carried out on 120 patients with cognitive impairment referred to our Cognitive Neurology Unit, and who were evaluated by brain FDG-PET and a lumbar puncture for CSF biomarkers. In order to calculate their Kappa coefficient of concordance, the result of the FDG-PET and the set of the three CSF biomarkers in each patient was classified as normal, inconclusive, or AD-compatible. The relationship between the results of both methods was further assessed using logistic regression analysis, including the Aß1-42, tTau and pTau levels as quantitative predictors, and the FDG-PET result as the dependent variable. The weighted Kappa coefficient between FDG-PET and CSF biomarkers was 0.46 (95% CI: 0.35-0.57). Logistic regression analysis showed that the Aß1-42 and tTau values together were capable of discriminating an FDG-PET result metabolically suggestive of AD from one non-suggestive of AD, with a 91% sensitivity and 93% specificity at the cut-off line Aß1-42=44+1.3×tTau. The level of concordance between FDG-PET and CSF biomarkers was moderate, indicating their complementary value in diagnosing AD. The Aß1-42 and tTau levels in CSF help to predict the patient FDG-PET cortical metabolic status. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  7. Clinicopathological Features of Ductal Carcinoma In Situ from (18)F-FDG-PET Findings.

    PubMed

    Fujii, Takaaki; Yanai, Keiko; Tokuda, Shoko; Nakazawa, Yuko; Kurozumi, Sasagu; Obayashi, Sayaka; Yajima, Reina; Hirakata, Tomoko; Kuwano, Hiroyuki

    2017-09-01

    The presence of ductal carcinoma in situ (DCIS) can increase the risk of developing an invasive ductal carcinoma (IDC), but it is difficult to predict what will occur if a DCIS is left untreated. We reported the usefulness of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) for DCIS, and that the presence of FDG uptake in the tumor could be considered a predictor of invasive potential in patients with DCIS. In this study, we retrospectively evaluated the clinicopathological features of DCIS by using FDG-PET findings, and we evaluated the possibility of using FDG-PET in DCIS cases as a biomarker of which lesions will go on to become invasive. We investigated the cases of 185 consecutive patients with primary breast cancer who were diagnosed as having DCIS or IDC and underwent FDG-PET preoperatively. We divided the cases into two groups on the basis of histology; DCIS vs. IDC (n=171). The DCIS cases were divided into two groups on the basis of FDG uptake in the primary tumor. Fourteen of the 185 patients (7.4%) were revealed to have a DCIS. The analysis revealed that the SUVmax and the number of cases not detected by FDG-PET were significantly different between the DICS and IDC groups. The extent of the primary tumor was not significantly different between the two groups. In six cases (42.9%) of the 14 DCIS cases, no FDG uptake was detected by FDG-PET. The extent of tumor did not significantly differ between the two groups. In addition, all six cases without FDG uptake were of the diffuse-spread type, without mass formation. All eight cases with mass formation had FDG uptake. Our present findings suggest that the FDG-PET uptake reflects tumor burden or tumor density, which should be considered to be associated with the presence of invasion. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  8. Comparison of 18F-FDG PET/CT and PET/MRI in patients with multiple myeloma

    PubMed Central

    Sachpekidis, Christos; Hillengass, Jens; Goldschmidt, Hartmut; Mosebach, Jennifer; Pan, Leyun; Schlemmer, Heinz-Peter; Haberkorn, Uwe; Dimitrakopoulou-Strauss, Antonia

    2015-01-01

    PET/MRI represents a promising hybrid imaging modality with several potential clinical applications. Although PET/MRI seems highly attractive in the diagnostic approach of multiple myeloma (MM), its role has not yet been evaluated. The aims of this prospective study are to evaluate the feasibility of 18F-FDG PET/MRI in detection of MM lesions, and to investigate the reproducibility of bone marrow lesions detection and quantitative data of 18F-FDG uptake between the functional (PET) component of PET/CT and PET/MRI in MM patients. The study includes 30 MM patients. All patients initially underwent 18F-FDG PET/CT (60 min p.i.), followed by PET/MRI (120 min p.i.). PET/CT and PET/MRI data were assessed and compared based on qualitative (lesion detection) and quantitative (SUV) evaluation. The hybrid PET/MRI system provided good image quality in all cases without artefacts. PET/MRI identified 65 of the 69 lesions, which were detectable with PET/CT (94.2%). Quantitative PET evaluations showed the following mean values in MM lesions: SUVaverage=5.5 and SUVmax=7.9 for PET/CT; SUVaverage=3.9 and SUVmax=5.8 for PET/MRI. Both SUVaverage and SUVmax were significantly higher on PET/CT than on PET/MRI. Spearman correlation analysis demonstrated a strong correlation between both lesional SUVaverage (r=0.744) and lesional SUVmax (r=0.855) values derived from PET/CT and PET/MRI. Regarding detection of myeloma skeletal lesions, PET/MRI exhibited equivalent performance to PET/CT. In terms of tracer uptake quantitation, a significant correlation between the two techniques was demonstrated, despite the statistically significant differences in lesional SUVs between PET/CT and PET/MRI. PMID:26550538

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

    PubMed Central

    Vriens, Dennis; Arens, Anne I.J.; Hutchings, Martin; Oyen, Wim J.G.

    2012-01-01

    Abstract It has been shown that [18F]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 adenocarcinoma of the esophagogastric junction, in order to investigate whether the use of PET-guided treatment individualization results in a survival benefit. In Hodgkin lymphoma and aggressive non-Hodgkin lymphoma, several trials are ongoing. Some studies aim to investigate the use of PET in early identification of metabolic non-responders in order to intensify treatment to improve survival. Other studies aim at reducing toxicity without adversely affecting cure rates by safely de-escalating therapy in metabolic responders. In solid tumors the first PET response-adjusted treatment trials have been realized in adenocarcinoma of the esophagogastric junction. These trials showed that patients with an early metabolic response to neoadjuvant chemotherapy benefit from this treatment, whereas metabolic non-responders should switch early to surgery, thus reducing the risk of tumor progression during chemotherapy and the risk of toxic death. The trials provide a model for designing response-guided treatment algorithms in other malignancies. PET-guided treatment algorithms are the promise of the near future; the choice of therapy, its intensity, and its duration will become better adjusted to the biology of the individual patient. Today’s major challenge is to investigate the impact on patient outcome of personalized response-adapted treatment concepts. PMID:23023063

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

    PubMed

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

    2014-04-01

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

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

    PubMed

    Li, Zu-Gui; Qin, Xiao-Jing

    2015-01-01

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

  12. Spectrum of the Breast Lesions With Increased 18F-FDG Uptake on PET/CT

    PubMed Central

    Dong, Aisheng; Wang, Yang; Lu, Jianping; Zuo, Changjing

    2016-01-01

    Abstract Interpretation of 18F-FDG PET/CT studies in breast is challenging owing to nonspecific FDG uptake in various benign and malignant conditions. Benign conditions include breast changes in pregnancy and lactation, gynecomastia, mastitis, fat necrosis, fibroadenoma, intraductal papilloma, and atypical ductal hyperplasia. Among malignancies, invasive ductal carcinoma and invasive lobular carcinoma are common histological types of breast carcinoma. Rarely, other unusual histological types of breast carcinomas (eg, intraductal papillary carcinoma, invasive micropapillary carcinoma, medullary carcinoma, mucinous carcinoma, and metaplastic carcinoma), lymphoma, and metastasis can be the causes. Knowledge of a wide spectrum of hypermetabolic breast lesions on FDG PET/CT is essential in accurate reading of FDG PET/CT. The purpose of this atlas article is to demonstrate features of various breast lesions encountered at our institution, both benign and malignant, which can result in hypermetabolism on FDG PET/CT imaging. PMID:26975010

  13. Controversies on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma.

    PubMed

    Adams, Hugo J A; Kwee, Thomas C

    2016-12-01

    Hodgkin lymphoma, even in advanced-stage, is a highly curable malignancy, but treatment is associated with short-term toxicity and long-term side effects. Early predictive markers are required to identify those patients who do not require the full-length standard therapy (and thus qualify for therapy de-escalation) and those patients who will not be cured by standard therapy (and thus qualify for therapy escalation). Multiple trials have assessed the value of (18) F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) after a few cycles of chemotherapy (also known as 'interim FDG-PET') in predicting outcome in advanced-stage Hodgkin lymphoma. Furthermore, multiple interim FDG-PET-adapted trials, in which patients with positive interim FDG-PET scans are assigned to escalated therapies, and patients with negative interim FDG-PET scans are assigned to de-escalated therapies, have recently been published or are currently ongoing, with generally heterogeneous results. The present article reports the currently available evidence (and controversies) on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma in patients with positive and negative interim FDG-PET findings following continuation of standard chemotherapy or escalated/de-escalated therapy. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Automated Identification of Dementia Using FDG-PET Imaging

    PubMed Central

    Wen, Lingfeng; Fulham, Michael; Feng, David Dagan

    2014-01-01

    Parametric FDG-PET images offer the potential for automated identification of the different dementia syndromes. However, various existing image features and classifiers have their limitations in characterizing and differentiating the patterns of this disease. We reported a hybrid feature extraction, selection, and classification approach, namely, the GA-MKL algorithm, for separating patients with suspected Alzheimer's disease and frontotemporal dementia from normal controls. In this approach, we extracted three groups of features to describe the average level, spatial variation, and asymmetry of glucose metabolic rates in 116 cortical volumes. An optimal combination of features, that is, capable of classifying dementia cases was identified by a genetic algorithm- (GA-) based method. The condition of each FDG-PET study was predicted by applying the selected features to a multikernel learning (MKL) machine, in which the weighting parameter of each kernel function can be automatically estimated. We compared our approach to two state-of-the-art dementia identification algorithms on a set of 129 clinical cases and improved the performance in separating the dementia types, achieving accuracy of 94.62%. There is a very good agreement between the proposed automated technique and the diagnosis made by clinicians. PMID:24672787

  15. Automated identification of dementia using FDG-PET imaging.

    PubMed

    Xia, Yong; Lu, Shen; Wen, Lingfeng; Eberl, Stefan; Fulham, Michael; Feng, David Dagan

    2014-01-01

    Parametric FDG-PET images offer the potential for automated identification of the different dementia syndromes. However, various existing image features and classifiers have their limitations in characterizing and differentiating the patterns of this disease. We reported a hybrid feature extraction, selection, and classification approach, namely, the GA-MKL algorithm, for separating patients with suspected Alzheimer's disease and frontotemporal dementia from normal controls. In this approach, we extracted three groups of features to describe the average level, spatial variation, and asymmetry of glucose metabolic rates in 116 cortical volumes. An optimal combination of features, that is, capable of classifying dementia cases was identified by a genetic algorithm- (GA-) based method. The condition of each FDG-PET study was predicted by applying the selected features to a multikernel learning (MKL) machine, in which the weighting parameter of each kernel function can be automatically estimated. We compared our approach to two state-of-the-art dementia identification algorithms on a set of 129 clinical cases and improved the performance in separating the dementia types, achieving accuracy of 94.62%. There is a very good agreement between the proposed automated technique and the diagnosis made by clinicians.

  16. Simultaneous scanning of two mice in a small-animal PET scanner: a simulation-based assessment of the signal degradation.

    PubMed

    Reilhac, Anthonin; Boisson, Frédéric; Wimberley, Catriona; Parmar, Arvind; Zahra, David; Hamze, Hasar; Davis, Emma; Arthur, Andrew; Bouillot, Caroline; Charil, Arnaud; Grégoire, Marie-Claude

    2016-02-07

    In PET imaging, research groups have recently proposed different experimental set ups allowing multiple animals to be simultaneously imaged in a scanner in order to reduce the costs and increase the throughput. In those studies, the technical feasibility was demonstrated and the signal degradation caused by additional mice in the FOV characterized, however, the impact of the signal degradation on the outcome of a PET study has not yet been studied. Here we thoroughly investigated, using Monte Carlo simulated [18F]FDG and [11C]Raclopride PET studies, different experimental designs for whole-body and brain acquisitions of two mice and assessed the actual impact on the detection of biological variations as compared to a single-mouse setting. First, we extended the validation of the PET-SORTEO Monte Carlo simulation platform for the simultaneous simulation of two animals. Then, we designed [18F]FDG and [11C]Raclopride input mouse models for the simulation of realistic whole-body and brain PET studies. Simulated studies allowed us to accurately estimate the differences in detection between single- and dual-mode acquisition settings that are purely the result of having two animals in the FOV. Validation results showed that PET-SORTEO accurately reproduced the spatial resolution and noise degradations that were observed with actual dual phantom experiments. The simulated [18F]FDG whole-body study showed that the resolution loss due to the off-center positioning of the mice was the biggest contributing factor in signal degradation at the pixel level and a minimal inter-animal distance as well as the use of reconstruction methods with resolution modeling should be preferred. Dual mode acquisition did not have a major impact on ROI-based analysis except in situations where uptake values in organs from the same subject were compared. The simulated [11C]Raclopride study however showed that dual-mice imaging strongly reduced the sensitivity to variations when mice were

  17. Simultaneous scanning of two mice in a small-animal PET scanner: a simulation-based assessment of the signal degradation

    NASA Astrophysics Data System (ADS)

    Reilhac, Anthonin; Boisson, Frédéric; Wimberley, Catriona; Parmar, Arvind; Zahra, David; Hamze, Hasar; Davis, Emma; Arthur, Andrew; Bouillot, Caroline; Charil, Arnaud; Grégoire, Marie-Claude

    2016-02-01

    In PET imaging, research groups have recently proposed different experimental set ups allowing multiple animals to be simultaneously imaged in a scanner in order to reduce the costs and increase the throughput. In those studies, the technical feasibility was demonstrated and the signal degradation caused by additional mice in the FOV characterized, however, the impact of the signal degradation on the outcome of a PET study has not yet been studied. Here we thoroughly investigated, using Monte Carlo simulated [18F]FDG and [11C]Raclopride PET studies, different experimental designs for whole-body and brain acquisitions of two mice and assessed the actual impact on the detection of biological variations as compared to a single-mouse setting. First, we extended the validation of the PET-SORTEO Monte Carlo simulation platform for the simultaneous simulation of two animals. Then, we designed [18F]FDG and [11C]Raclopride input mouse models for the simulation of realistic whole-body and brain PET studies. Simulated studies allowed us to accurately estimate the differences in detection between single- and dual-mode acquisition settings that are purely the result of having two animals in the FOV. Validation results showed that PET-SORTEO accurately reproduced the spatial resolution and noise degradations that were observed with actual dual phantom experiments. The simulated [18F]FDG whole-body study showed that the resolution loss due to the off-center positioning of the mice was the biggest contributing factor in signal degradation at the pixel level and a minimal inter-animal distance as well as the use of reconstruction methods with resolution modeling should be preferred. Dual mode acquisition did not have a major impact on ROI-based analysis except in situations where uptake values in organs from the same subject were compared. The simulated [11C]Raclopride study however showed that dual-mice imaging strongly reduced the sensitivity to variations when mice were

  18. [Business administration of PET facilities: a cost analysis of three facilities utilizing delivery FDG].

    PubMed

    Mitsutake, Naohiro; Oku, Shinya; Fujii, Ryo; Furui, Yuji; Yasunaga, Hideo

    2008-05-01

    PET (positron emission tomography) has been proved to be a powerful imaging tool in clinical oncology. The number of PET facilities in Japan has remarkably increased over the last decade. Furthermore, the approval of delivery FDG in 2005 resulted in a tremendous expansion of the PET institutions without a cyclotron facility. The aim of this study was to conduct a cost analysis of PET institutions that utilized delivery FDG. Three PET facilities using delivery FDG were investigated about the costs for PET service. Fixed costs included depreciation costs for construction and medical equipments such as positron camera. Variable costs consisted of costs for medical materials including delivery FDG. The break-even point was analyzed in each of three institutions. In the three hospitals (A, B and C), the annual number of PET scan was 1,591, 1,637 and 914, while cost per scan was accounted as yen 110,262, yen 111,091, and yen 134,192, respectively. The break-even point was calculated to be 2,583, 2,679 and 2,081, respectively. PET facilities utilizing delivery FDG seemed to have difficulty in business administration. Such a situation suggests the possibility that the current supply of PET facilities might exceed actual demand for the service. The efficiency of resource allocation should be taken into consideration in the future health service researches on PET.

  19. Evaluation of ¹⁸F-FDG PET/MRI, ¹⁸F-FDG PET/CT, MRI, and CT in whole-body staging of recurrent breast cancer.

    PubMed

    Sawicki, Lino M; Grueneisen, Johannes; Schaarschmidt, Benedikt M; Buchbender, Christian; Nagarajah, James; Umutlu, Lale; Antoch, Gerald; Kinner, Sonja

    2016-02-01

    To compare the diagnostic performance of (18)F-fluordesoxyglucose positron emission tomography/magnetic resonance imaging ((18)F-FDG PET/MRI) with (18)F-FDG PET/computed tomography ((18)F-FDG PET/CT), MRI, and CT in whole-body staging of recurrent breast cancer. Twenty-one consecutive patients (age 59.4 ± 11.5 years, range 38.5-76.9 years; 20 female, 1 male) with suspected breast cancer recurrence underwent a clinically indicated (18)F-FDG PET/CT and subsequently a (18)F-FDG PET/MRI examination in a single injection protocol (mean injected activity: 257 ± 44 MBq (18)F-FDG). Each (18)F-FDG PET/MRI, (18)F-FDG PET/CT, as well as the CT component of PET/CT (CTPET/CT) and MR images of PET/MRI (MRIPET/MRI) were separately evaluated by two radiologists regarding lesion count, lesion localization, and lesion categorization (benign/malignant). The reference standard was based on histopathological results as well as prior and follow-up imaging. A Wilcoxon test assessed differences in SUVmax between (18)F-FDG PET/MRI and (18)F-FDG PET/CT. Correlation of SUVmax between (18)F-FDG PET/MRI and (18)F-FDG PET/CT was calculated using Pearson's correlation coefficient. Interobserver agreement on dignity ratings was evaluated using Cohen's kappa. According to the reference standard, 17 patients had breast cancer recurrence. (18)F-FDG PET/MRI, (18)F-FDG PET/CT, and MRIPET/MRI correctly identified each of the 17 patients, whereas CTPET/CT correctly identified 15 of the 17 patients. A total of 134 lesions were described (116 malignant, 18 benign). (18)F-FDG PET/MRI detected all 134 lesions, of which (18)F-FDG PET/CT, MRIPET/MRI, and CTPET/CT detected 97.0%, 96.2%, and 74.6%, respectively. (18)F-FDG PET/MRI yielded the highest proportion of correctly categorized lesions (98.5%) compared with (18)F-FDG PET/CT (94.8%), MRIPET/MRI (88.1%), and CTPET/CT (57.5%). SUVmax was strongly correlated (r=0.72) but measured significantly higher on (18)F-FDG PET/MRI than on (18)F-FDG PET/CT in

  20. Abdomen: normal variations and benign conditions resulting in uptake on FDG-PET/CT.

    PubMed

    Zukotynski, Katherine; Kim, Chun K

    2014-04-01

    The increasing use of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in oncology has led to: improved sensitivity and specificity in detecting localized and metastatic disease, increased ability to target biopsies to the site of most aggressive disease, and development of a noninvasive biomarker to assess prognosis and effects of therapy. However, for correct interpretation of FDG-PET/CT studies, an understanding of both normal and abnormal imaging appearances commonly encountered in oncology patients is important. This article discusses commonly seen normal variations and benign findings on FDG-PET/CT of the abdomen.

  1. Monitoring the Therapy of Extensive Osseous Sarcoidosis With FDG PET/CT.

    PubMed

    Yang, Hua; Numani, Shah; Liu, Shuang

    2017-02-24

    FDG PET/CT was performed in a 47-year-old man to evaluate possible malignancy of the spine revealed by MRI. The PET images revealed numerous focal FDG activity throughout the skeletal system. In addition, multiple foci of the increased activity in the mediastinal and hilar nodes were noted, suggestive of sarcoidosis, which was proven following biopsy. Therapy for sarcoidosis was initiated. In the subsequent 4 follow-up FDG PET/CT scans, the activity in both the bones and mediastinal/hilar regions fluctuated. However, anatomical abnormality in the bones on the CT images was never visualized during the entire clinical course.

  2. Abnormal 18 F-FDG and 82 Rb PET Findings in Chagas Heart Disease.

    PubMed

    Salimy, Medhi S; Parwani, Purvi J; Mukai, Kanae; Pampaloni, Miguel Hernandez; Flavell, Robert R

    2017-03-03

    Uptake of the radiopharmaceutical F-FDG visualized by PET imaging can reflect abnormal myocardial inflammation. When utilized in conjunction with other imaging modalities, such as echocardiography, PET F-FDG imaging can help distinguish between active cardiac sarcoidosis and other etiologies of nonischemic cardiomyopathy. We present a case of a 46-year-old man with nonischemic cardiomyopathy and ventricular tachycardia who underwent an echocardiogram suggestive of cardiac Chagas disease. A subsequent F-FDG PET demonstrated abnormal hypermetabolism. The diagnosis was confirmed by positive serologic examination results.

  3. Cat-Scratch Disease: A Pitfall for Lymphoma Evaluation by FDG-PET/CT.

    PubMed

    Dubreuil, Julien; Dony, Arthur; Salles, Gilles; Traverse-Glehen, Alexandra; Giammarile, Francesco; Skanjeti, Andrea

    2017-02-01

    FDG-PET/CT is a standard of care in staging and response assessment of Hodgkin lymphoma. Hence, it is important to recognize pitfalls owing to the potential therapeutic impact. We report a case of a 29-year-old woman affected by stage III bulky Hodgkin lymphoma. The interim FDG-PET/CT showed a complete metabolic response. After three new cycles of chemotherapy, the patient showed fever and lymphadenopathy at clinic examination, PET/CT revealed several FDG uptakes at lymph nodes in inguinal and iliac region. Pathologic analyses, after biopsy and serologic examinations, led to the diagnosis of cat-scratch disease.

  4. Unilateral thalamic hypometabolism on FDG brain PET in patient with temporal lobe epilepsy

    PubMed Central

    Sager, Sait; Asa, Sertac; Uslu, Lebriz; Halac, Metin

    2011-01-01

    Interictal Brain F-18 fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) imaging has been widely used for localizing the focus of a seizure. Hypometabolism in the extratemporal cortex on FDG-PET study is an important finding to localize seizure focus, which might be seen as ipsilateral, contralateral or bilateral thalamus hypometabolism in epileptic patients. In this case report, it is aimed to show ipsilateral thalamus hypomethabolism on FDG PET brain study of a 24-year-old male patient with temporal lobe epilepsy. PMID:22174515

  5. Practical Aspects of 18F-FDG PET When Receiving 18F-FDG from a Distant Supplier.

    PubMed

    Ducharme, Jaylene; Goertzen, Andrew L; Patterson, Judy; Demeter, Sandor

    2009-09-01

    With PET becoming more widely used, there is an increase in the number of imaging centers being forced to rely on distant suppliers of (18)F-FDG. Because of the large distances between major urban centers, this is particularly true for PET centers in Canada. Our PET center, located in Winnipeg, Manitoba, Canada, currently purchases (18)F-FDG from a commercial vendor located more than 1,000 km from Winnipeg, necessitating transport by commercial airline cargo. This dependence on air transport and a distant supplier creates a situation in which our (18)F-FDG supply is less reliable than it would be with onsite production. In this article, we offer insight into the obstacles we have encountered in imaging with a distant supplier of (18)F-FDG and the solutions we have implemented to minimize the disruption to our patients and maximize the number of scans performed each year. The development of contingency plans and protocols designed to suit our operating environment has allowed us to increase the number of patient scans obtained from 659 in year 1 to 993 in year 3, an increase of 51%, despite an increase in our actual number of scan days of only 24%. (18)F-FDG injection timetables are presented for a variety of scenarios including normal delivery, low shipped activity, and delayed delivery. Through the careful establishment of contingency protocols and management of (18)F-FDG shipments, patient throughput can be increased and disruptions minimized.

  6. Sub-millimetre DOI detector based on monolithic LYSO and digital SiPM for a dedicated small-animal PET system.

    PubMed

    Marcinkowski, Radosław; Mollet, Pieter; Van Holen, Roel; Vandenberghe, Stefaan

    2016-03-07

    The mouse model is widely used in a vast range of biomedical and preclinical studies. Thanks to the ability to detect and quantify biological processes at the molecular level in vivo, PET has become a well-established tool in these investigations. However, the need to visualize and quantify radiopharmaceuticals in anatomic structures of millimetre or less requires good spatial resolution and sensitivity from small-animal PET imaging systems.In previous work we have presented a proof-of-concept of a dedicated high-resolution small-animal PET scanner based on thin monolithic scintillator crystals and Digital Photon Counter photosensor. The combination of thin monolithic crystals and MLE positioning algorithm resulted in an excellent spatial resolution of 0.7 mm uniform in the entire field of view (FOV). However, the limitation of the scanner was its low sensitivity due to small thickness of the lutetium-yttrium oxyorthosilicate (LYSO) crystals (2 mm).Here we present an improved detector design for a small-animal PET system that simultaneously achieves higher sensitivity and sustains a sub-millimetre spatial resolution. The proposed detector consists of a 5 mm thick monolithic LYSO crystal optically coupled to a Digital Photon Counter. Mean nearest neighbour (MNN) positioning combined with depth of interaction (DOI) decoding was employed to achieve sub-millimetre spatial resolution. To evaluate detector performance the intrinsic spatial resolution, energy resolution and coincidence resolving time (CRT) were measured. The average intrinsic spatial resolution of the detector was 0.60 mm full-width-at-half-maximum (FWHM). A DOI resolution of 1.66 mm was achieved. The energy resolution was 23% FWHM at 511 keV and CRT of 529 ps were measured. The improved detector design overcomes the sensitivity limitation of the previous design by increasing the nominal sensitivity of the detector block and retains an excellent intrinsic spatial resolution.

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

    DOE PAGES

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

    2014-06-14

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-10-15

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

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

    SciTech Connect

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

    2014-06-14

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

  11. C11-Acetate and F-18 FDG PET for Men With Prostate Cancer Bone Metastases

    PubMed Central

    Yu, Evan Y.; Muzi, Mark; Hackenbracht, Joy A.; Rezvani, Brian B.; Link, Jeanne M.; Montgomery, Robert Bruce; Higano, Celestia S.; Eary, Janet F.; Mankoff, David A.

    2011-01-01

    Purpose of the Report This study tested the feasibility of C11-acetate (acetate) positron emission tomography (PET) imaging to assess response to therapy in men with bone metastatic prostate cancer and compared results for disease detection and response evaluation with F-18 fluorodeoxyglucose (FDG) PET. Materials and Methods Men with ≥3 prostate cancer bone metastases identified by Tc-99m methylene diphosphonate (MDP) bone scintigraphy and/or computed tomography were enrolled in a prospective study of serial acetate and FDG PET imaging. Patients were imaged before and 6 to 12 weeks after initial androgen deprivation therapy for new metastatic prostate cancer or first-line chemotherapy with docetaxel for castration-resistant prostate cancer. Qualitative assessment and changes in the tumor:normal uptake ratio were used to assess response by both acetate and FDG PET. In addition, the detection of bone metastases pretherapy was compared for acetate and FDG PET. Results A total of 8 patients with documented bone metastases were imaged, of which 6 were imaged both pre- and post-therapy. Acetate PET detected bone metastases in all 8 patients, whereas FDG PET detected lesions in 6 of the 7 imaged patients. Acetate PET generally detected more metastases with a higher tumor:normal uptake ratio. Qualitative and quantitative assessments of post-treatment response correlated with composite clinical designations of response, stable disease, or progression in 6 of 6 and 5 of 6 by acetate and 4 of 5 and 3 of 5 by FDG PET, respectively. Conclusions In this pilot study, results indicate that acetate PET holds promise for response assessment of prostate cancer bone metastases and is complementary to FDG PET in bone metastasis detection. PMID:21285676

  12. Validation of FDG-PET/MRI coregistration in nonlesional refractory childhood epilepsy.

    PubMed

    Rubí, Sebastià; Setoain, Xavier; Donaire, Antonio; Bargalló, Núria; Sanmartí, Francesc; Carreño, Mar; Rumià, Jordi; Calvo, Anna; Aparicio, Javier; Campistol, Jaume; Pons, Francesca

    2011-12-01

    To validate the use of 18F-fluorodeoxyglucose-positron emission tomography/magnetic resonance imaging (FDG-PET/MRI) coregistration for epileptogenic zone detection in children with MRI nonlesional refractory epilepsy and to assess its ability to guide a second interpretation of the MRI studies. Thirty-one children with refractory epilepsy whose MRI results were nonlesional were included prospectively. All patients underwent presurgical evaluation following the standard protocol of our epilepsy unit, which included FDG-PET and FDG-PET/MRI coregistration. Cerebral areas of decreased uptake in PET and PET/MRI fusion images were compared visually and then contrasted with presumed epileptogenic zone localization, which had been obtained from other clinical data. A second interpretation of MRI studies was carried out, focusing on the exact anatomic region in which hypometabolism was located in FDG-PET/MRI fusion images. Both FDG-PET and FDG-PET/MRI detected hypometabolism in 67.8% of patients, with good concordance on a subject basis and on the cerebral region involved (κ statistic = 0.83 and 0.79, respectively). Hypometabolism detected by single PET, as well as by PET/MRI fusion images, was located in the same hemisphere, as indicated by electroclinical data in 58% of patients, and at the same place in 39% of cases. Of the patients who showed hypometabolism on PET/MRI, 43% also experienced changes in the guided second MRI interpretation, from nonlesional to subtle-lesional. PET/MRI coregistration is an imaging variant that is at least as accurate as PET alone in detecting epileptogenic zone in pediatric nonlesional patients, and can guide a second look at MRI studies previously reported as nonlesional, turning a meaningful percentage into subtle-lesional. Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.

  13. Is FDG-PET/CT useful for managing malignant pleural mesothelioma?

    PubMed

    Otsuka, Hideki; Terazawa, Kaori; Morita, Naomi; Otomi, Yoichi; Yamashita, Kyo; Nishitani, Hiromu

    2009-02-01

    Imaging techniques such as CT, MRI and PET/CT have essential pre- and post-treatment roles in detecting tumors and evaluating the extension of malignant pleural mesothelioma (MPM). We sough to evaluate the advantages and limitations on FDG-PET/CT findings. We performed 13 FDG-PET/CT studies in 9 patients with MPM (8 males, 1 female, aged 51 to 84 years, 9 at the initial diagnosis, 4 follow up studies). We reviewed FDG-PET/CT findings of primary tumors, recurrent tumors, lymph nodes, metastasis. All primary and recurrent tumors were FDG positive. The uptake patterns at initial diagnosis were; diffuse+multi-nodular uptake pattern in 5, diffuse irregular thickened uptake pattern in 2, some focal thickened pattern in one, and a slight diffuse uptake pattern in one. Two of the 3 patients diagnosed as N0 by PET and operated on had negative lymph nodes confirmed pathologically. The other patient diagnosed as N0 by PET, who had one month of time lag between PET/CT examination and surgery, was confirmed as N2 by extrapleural pneumonectomy. In 3 patients, hilar or mediastinal lymph nodes were difficult to distinguish from irregular pleural thickening. One patient had a FDG positive lymph node in the ipsilateral supraclavicular region confirmed as metastasis (N3). One patient had a FDG positive lymph node in the para-aortic region. Lung metastasis was seen in one patient (M1). In another patient, two focal nodular uptakes in the colon were detected and confirmed as colon polyps (pathologically Group 3-4). At restaging, 3 of 4 patients showed diffuse+multi-nodular uptake and one patient showed multi-nodular uptake. The utility of FDG-PET/CT is limited for evaluation of primary tumor extension and nodal status. FDG-PET/CT is useful for detecting distant metastasis and for evaluating activity in supraclavicular or abdominal lymph nodes. It is also useful for identifying unsuspected diseases.

  14. MR-compatibility of a high-resolution small animal PET insert operating inside a 7 T MRI.

    PubMed

    Thiessen, J D; Shams, E; Stortz, G; Schellenberg, G; Bishop, D; Khan, M S; Kozlowski, P; Retière, F; Sossi, V; Thompson, C J; Goertzen, A L

    2016-11-21

    A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding. MR-compatibility measurements included field mapping of the static magnetic field (B 0) and the time-varying excitation field (B 1) as well as acquisitions with multiple pulse sequences: spin echo (SE), rapid imaging with refocused echoes (RARE), fast low angle shot (FLASH) gradient echo, and echo planar imaging (EPI). B 0 field maps revealed a small degradation in the mean homogeneity (+0.1 ppm) when the PET insert was installed and operating. No significant change was observed in the B 1 field maps or the image homogeneity of various MR images, with a 9% decrease in the signal-to-noise ratio (SNR) observed only in EPI images acquired with the PET insert installed and operating. PET detector flood histograms, photopeak amplitudes, and energy resolutions were unchanged in individual PET detector modules when acquired during MRI operation. There was a small baseline shift on the PET detector signals due to the switching amplifiers used to power MRI gradient pulses. This baseline shift was observable when measured with an oscilloscope and varied as a function of the gradient duty cycle, but had no noticeable effect on the performance of the PET detector modules. Compact front-end electronics and effective RF shielding led to minimal cross-interference between the PET and MRI systems. Both PET detector and MRI performance was excellent, whether operating as a standalone system or a hybrid PET/MRI.

  15. Assessment of MR-compatibility of SiPM PET insert using short optical fiber bundles for small animal research

    NASA Astrophysics Data System (ADS)

    Kang, H. G.; Hong, S. J.; Ko, G. B.; Yoon, H. S.; Song, I. C.; Rhee, J. T.; Lee, J. S.

    2015-12-01

    Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) can provide new perspectives in human disease research because of their complementary in-vivo imaging techniques. Previously, we have developed an MR-compatible PET insert based on optical fibers using silicon photomultipliers (SiPM). However when echo planar imaging (EPI) sequence was performed, signal intensity was slowly decreased by -0.9% over the 5.5 minutes and significant geometrical distortion was observed as the PET insert was installed inside an MRI bore, indicating that the PET electronics and its shielding boxes might have been too close to an MR imaging object. In this paper, optical fiber bundles with a length of 54 mm instead of 31 mm were employed to minimize PET interference on MR images. Furthermore, the LYSO crystals with a size of 1.5 × 1.5 × 7.0 mm3 were used instead of 2.47 × 2.74 × 20.0 mm3 for preclinical PET/MR applications. To improve the MR image quality, two receive-only loop coils were used. The effects of the PET insert on the SNR of the MR image either for morphological or advanced MR pulse sequences such as diffusion weighted imaging (DWI), functional MRI (fMRI), and magnetic resonance spectroscopy (MRS) were investigated. The quantitative MR compatibility such as B0 and B1 field homogeneity without PET, with `PET OFF', and with `PET ON' was also evaluated. In conclusion, B0 maps were not affected by the proposed PET insert whereas B1 maps were significantly affected by the PET insert. The advanced MRI sequences such as DWI, EPI, and MRS can be performed without a significant MR image quality degradation.

  16. MR-compatibility of a high-resolution small animal PET insert operating inside a 7 T MRI

    NASA Astrophysics Data System (ADS)

    Thiessen, J. D.; Shams, E.; Stortz, G.; Schellenberg, G.; Bishop, D.; Khan, M. S.; Kozlowski, P.; Retière, F.; Sossi, V.; Thompson, C. J.; Goertzen, A. L.

    2016-11-01

    A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding. MR-compatibility measurements included field mapping of the static magnetic field (B 0) and the time-varying excitation field (B 1) as well as acquisitions with multiple pulse sequences: spin echo (SE), rapid imaging with refocused echoes (RARE), fast low angle shot (FLASH) gradient echo, and echo planar imaging (EPI). B 0 field maps revealed a small degradation in the mean homogeneity (+0.1 ppm) when the PET insert was installed and operating. No significant change was observed in the B 1 field maps or the image homogeneity of various MR images, with a 9% decrease in the signal-to-noise ratio (SNR) observed only in EPI images acquired with the PET insert installed and operating. PET detector flood histograms, photopeak amplitudes, and energy resolutions were unchanged in individual PET detector modules when acquired during MRI operation. There was a small baseline shift on the PET detector signals due to the switching amplifiers used to power MRI gradient pulses. This baseline shift was observable when measured with an oscilloscope and varied as a function of the gradient duty cycle, but had no noticeable effect on the performance of the PET detector modules. Compact front-end electronics and effective RF shielding led to minimal cross-interference between the PET and MRI systems. Both PET detector and MRI performance was excellent, whether operating as a standalone system or a hybrid PET/MRI.

  17. Usefulness of FDG, MET and FLT-PET Studies for the Management of Human Gliomas

    PubMed Central

    Miyake, Keisuke; Shinomiya, Aya; Okada, Masaki; Hatakeyama, Tetsuhiro; Kawai, Nobuyuki; Tamiya, Takashi

    2012-01-01

    The use of positron imaging agents such as FDG, MET, and FLT is expected to lead the way for novel applications toward efficient malignancy grading and treatment of gliomas. In this study, the usefulness of FDG, MET and FLT-PET images was retrospectively reviewed by comparing their histopathological findings. FDG, MET, and FLT-PET were performed in 27 patients with WHO grade IV, 15 patients with WHO grade III, and 12 patients with WHO grade II during 5.5 years. The resulting PET images were compared by measuring SUVs and T/N ratios (tumor to normal tissue ratios). Although there were no significant differences in FDG-PET, there were significant differences in the T/N ratios in the MET-PET between WHO grades II and IV and in the FLT-PET between the WHO grades III and IV. In glioblastoma patients, the SUVs of the areas depicted by MRI in the MET-PET were different from those SUVs in the FLT-PET. Importantly, the areas with high SUVs in both MET-PET and FLT-PET were also high in Ki-67 index and were histologically highly malignant. PET imaging is a noninvasive modality that is useful in determining a tumor area for removal as well as improving preoperative diagnosis for gliomas. PMID:22577290

  18. FDG-PET findings in patients with galactosaemia.

    PubMed

    Dubroff, J G; Ficicioglu, C; Segal, S; Wintering, N A; Alavi, A; Newberg, A B

    2008-08-01

    Despite treatment with a galactose-restricted diet, many galactosaemia patients develop lifelong cognitive impairment, speech abnormalities and a gamut of neurological problems including cognitive impairment and tremors. No study has explored changes in cerebral glucose metabolism in patients with galactosaemia. Five patients with galactosaemia had ages ranging from 20 to 40 years (mean age 28 years) and eight similarly aged controls received brain [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) scans. PET scans were analysed using a previously validated template methodology of regions of interest (ROIs). Count ratios for each anatomical ROI were compared between the galactosaemic patients and the healthy controls. Statistical parametric mapping (SPM) software was also used to further analyse the data. ROI analysis showed that galactosaemic patients had significant bilateral decreases in cerebral glucose metabolism in the superior temporal gyrus, medial occipital lobe, parietal lobe, cerebellum, calcarine cortex, superior frontal cortex, and superior parietal cortex when compared with controls. Significant increases were seen in the cingulate gyrus and temporal poles, bilaterally. SPM analysis revealed foci of decreased glucose metabolism in the caudate, cerebellum, precentral gyrus and cerebellar tonsils of galactosaemic patients. SPM also showed increased glucose metabolism in the subcallosal gyrus and claustrum. The results show significant abnormalities in cerebral function in patients with galactosaemia, particularly with widespread decreases in cortical metabolism. These abnormalities appear to be in brain regions that may be associated with the neuropsychological deficits in these patients. PET brain scans may be of value in galactosaemia patients to evaluate for dysfunction.

  19. Focal Colonic FDG Activity with PET/CT: Guidelines for Recommendation of Colonoscopy

    PubMed Central

    Liu, Tianye; Behr, Spencer; Khan, Sana; Osterhoff, Robert; Aparici, Carina Mari

    2015-01-01

    Focal 18F-fluorodeoxyglucose (FDG) colonic activity can be incidentally seen in positron emission tomography/computed tomography (PET/CT) scans. Its clinical significance is still unclear. The purpose of this study was to assess the significance of focal FDG activity in PET/CT scans by correlating the imaging findings to colonoscopy results, and come up with some guidelines for recommendation of follow-up colonoscopy. A total of 133 patients who underwent both 18F-FDG PET/CT for different oncological indications and colonoscopy within 3 months were retrospectively studied. Imaging, colonoscopy and pathology results were analyzed. Of the 133 FDG-PET/CT scans, 109/133 (82%) did not show focal colonic FDG activity, and 24/133 (18%) did. Of the 109/133 PET/CTs without focal colonic FDG activity, 109/109 (100%) did not have evidence of colon cancer after colonoscopy and histology. Of the 24/133 PET/CTs with focal colonic FDG activity, 10/24 (42%) had pathologic confirmation of colon cancer and 14/24 (58%) did not have evidence of colon cancer after colonoscopy and histological analysis. Sensitivity was 10/10 (100%), specificity 109/123 (89%), positive predictive value (PPV) 10/24 (42%) and negative predictive value (NPV) 109/109 (100%). Incidental focal 18FDG activity in PET/CT imaging shows a high sensitivity, specificity and NPV for malignancy, with a not so high PPV of 42%. Although some people would argue that a 42% chance of malignancy justifies colonoscopy, this maybe is not possible in all cases. However, the high sensitivity of the test does not allow these studies to be overlooked. We provide our recommendations as per when to send patients with focal FDG colonic activity to have further characterization with colonoscopy. PMID:25709541

  20. Unusual Horner's Syndrome in Recurrent Breast Cancer: Evaluation Using (18)F-FDG PET/CT.

    PubMed

    Park, Sohyun; Kim, Tae Sung; Kim, Seok-Ki

    2017-03-01

    (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a widely used imaging modality in the initial diagnosis of cancer, treatment response evaluation and detection of recurrence. Herein, we present the case of a 39-year-old female who presented right ptosis on the follow-up of breast cancer after surgery. Clinicians suspected Horner's syndrome, and the patient underwent FDG PET/CT for the evaluation of recurrence that could cause Horner's syndrome. FDG PET/CT demonstrated a focal hypermetabolic lesion in the right cervicothoracic junction area, corresponding to the preganglionic cervical sympathetic trunk. A subsequent needle biopsy was done, and the lesion was confirmed as metastatic ductal carcinoma. In this case, we could detect the exact location of the recurring lesion that caused Horner's syndrome using FDG PET/CT.

  1. Candida Esophagitis Incidentally Detected by 18F-FDG PET/CT in Metastatic Lung Adenocarcinoma

    PubMed Central

    Martínez-Amador, N; Martínez-Rodríguez, I; Quirce, R; Jiménez-Bonilla, J; Banzo, I

    2017-01-01

    The diagnostic significance of esophageal 18F-FDG uptake in oncologic patient is challenging. It may represent normal physiological uptake, inflammation, infection, or neoplasia. We present a patient with a recent diagnosis of non-small cell lung cancer stage IV and esophageal mild uptake on 18F-FDG PET/CT scan. Biopsy of esophageal mucosa demonstrated Candida esophagitis.

  2. Plasmacytoma of the ovary: additional role of 18F-FDG PET/CT.

    PubMed

    Santhosh, Sampath; Mittal, Bhagwant Rai; Raveendran, Ainharan; Jain, Vanita; Nijhawan, Raje; Kumar, Ritesh; Bhattacharya, Anish; Sharma, Suresh C

    2013-05-01

    We report a case of ovarian plasmacytomas where 18F-FDG PET/CT helped in staging by demonstrating increased FDG uptake limited to the ovary, and hence, surgical treatment was carried out as the disease was localized to the ovary.

  3. Multi-tracer small animal PET imaging of the tumour response to the novel pan-Erb-B inhibitor CI-1033.

    PubMed

    Dorow, Donna S; Cullinane, Carleen; Conus, Nelly; Roselt, Peter; Binns, David; McCarthy, Timothy J; McArthur, Grant A; Hicks, Rodney J

    2006-04-01

    This study was designed as "proof of concept" for a drug development model utilising multi-tracer serial small animal PET imaging to characterise tumour responses to molecularly targeted therapy. Mice bearing subcutaneous A431 human squamous carcinoma xenografts (n=6-8) were treated with the pan-Erb-B inhibitor CI-1033 or vehicle and imaged serially (days 0, 3 and 6 or 7) with [(18)F]fluorodeoxyglucose, [(18)F]fluoro-L: -thymidine, [(18)F]fluoro-azoazomycinarabinoside or [(18)F]fluoromisonidazole. Separate cohorts (n=3) were treated identically and tumours were assessed ex vivo for markers of glucose metabolism, proliferation and hypoxia. During the study period, mean uptake of all PET tracers generally increased for control tumours compared to baseline. In contrast, tracer uptake into CI-1033-treated tumours decreased by 20-60% during treatment. Expression of the glucose transporter Glut-1 and cell cycle markers was unchanged or increased in control tumours and generally decreased with CI-1033 treatment, compared to baseline. Thymidine kinase activity was reduced in all tumours compared to baseline at day 3 but was sevenfold higher in control versus CI-1033-treated tumours by day 6 of treatment. Uptake of the hypoxia marker pimonidazole was stable in control tumours but was severely reduced following 7 days of CI-1033 treatment. CI-1033 treatment significantly affects tumour metabolism, proliferation and hypoxia as determined by PET. The PET findings correlated well with ex vivo biomarkers for each of the cellular processes studied. These results confirm the utility of small animal PET for evaluation of the effectiveness of molecularly targeted therapies and simultaneously definition of specific cellular processes involved in the therapeutic response.

  4. FDG PET/CT Evidence of Effective Treatment of Cardiac Sarcoidosis With Adalimumab.

    PubMed

    Miller, Christina T; Sweiss, Nadera J; Lu, Yang

    2016-05-01

    A 53-year-old man with mediastinal lymph node biopsy and cardiac MRI-proven cardiac sarcoidosis (CS) received treatment with pacemaker and steroids. FDG PET/CT showed active CS despite treatment with prednisone and methotrexate. Addition of weekly adalimumab (Humira) injections was introduced for 3 months. Follow-up FDG PET/CT showed complete resolution of CS as well as improvement of other sarcoid lesions in the thoracic lymph nodes.

  5. Cognitive reserve associated with FDG-PET in preclinical Alzheimer disease.

    PubMed

    Ewers, Michael; Insel, Philip S; Stern, Yaakov; Weiner, Michael W

    2013-03-26

    To examine the effect of education (a surrogate measure of cognitive reserve) on FDG-PET brain metabolism in elderly cognitively healthy (HC) subjects with preclinical Alzheimer disease (AD). Fifty-two HC subjects (mean age 75 years) with FDG-PET and CSF measurement of Aβ1-42 were included from the prospective Alzheimer's Disease Neuroimaging Initiative biomarker study. HC subjects received a research classification of preclinical AD if CSF Aβ1-42 was <192 pg/mL (Aβ1-42 [+]) vs HC with normal Aβ (Aβ1-42 [-]). In regression analyses, we tested the interaction effect between education and CSF Aβ1-42 status (Aβ1-42 [+] vs Aβ1-42 [-]) on FDG-PET metabolism in regions of interest (ROIs) (posterior cingulate, angular gyrus, inferior/middle temporal gyrus) and the whole brain (voxel-based). An interaction between education and CSF Aβ1-42 status was observed for FDG-PET in the posterior cingulate (p < 0.001) and angular gyrus ROIs (p = 0.03), but was not significant for the inferior/middle temporal gyrus ROI (p = 0.06), controlled for age, sex, and global cognitive ability (Alzheimer's Disease Assessment Scale-cognitive subscale). The interaction effect was such that higher education was associated with lower FDG-PET in the Aβ1-42 (+) group, but with higher FDG-PET in the Aβ1-42 (-) group. Voxel-based analysis showed that this interaction effect was primarily restricted to temporo-parietal and ventral prefrontal brain areas. Higher education was associated with lower FDG-PET in preclinical AD (Aβ1-42 [+]), suggesting that cognitive reserve had a compensatory function to sustain cognitive ability in presence of early AD pathology that alters FDG-PET metabolism.

  6. Reproducibility of 18F-FDG PET uptake measurements in head and neck squamous cell carcinoma on both PET/CT and PET/MR

    PubMed Central

    Fischer, B M; Aznar, M C; Hansen, A E; Vogelius, I R; Löfgren, J; Andersen, F L; Loft, A; Kjaer, A; Højgaard, L; Specht, L

    2015-01-01

    Objective: To investigate reproducibility of fluorine-18 fludeoxyglucose (18F-FDG) uptake on 18F-FDG positron emission tomography (PET)/CT and 18F-FDG PET/MR scans in patients with head and neck squamous cell carcinoma (HNSCC). Methods: 30 patients with HNSCC were included in this prospective study. The patients were scanned twice before radiotherapy treatment with both PET/CT and PET/MR. Patients were scanned on the same scanners, 3 days apart and according to the same protocol. Metabolic tumour activity was measured by the maximum and peak standardized uptake value (SUVmax and SUVpeak, respectively), and total lesion glycolysis from the metabolic tumour volume defined from ≥50% SUVmax. Bland–Altman analysis with limits of agreement, coefficient of variation (CV) from the two modalities were performed in order to test the reproducibility. Furthermore, CVs from SUVmax and SUVpeak were compared. The area under the curve from cumulative SUV–volume histograms were measured and tested for reproducibility of the distribution of 18F-FDG uptake. Results: 24 patients had two pre-treatment PET/CT scans and 21 patients had two pre-treatment PET/MR scans available for further analyses. Mean difference for SUVmax, peak and mean was approximately 4% for PET/CT and 3% for PET/MR, with 95% limits of agreement less than ±20%. CV was small (5–7%) for both modalities. There was no significant difference in CVs between PET/CT and PET/MR (p = 0.31). SUVmax was not more reproducible than SUVpeak (p = 0.09). Conclusion: 18F-FDG uptake in PET/CT and PET/MR is highly reproducible and we found no difference in reproducibility between PET/CT and PET/MR. Advances in knowledge: This is the first report to test reproducibility of PET/CT and PET/MR. PMID:25634069

  7. Evaluation of a 3D point spread function (PSF) model derived from Monte Carlo simulation for a small animal PET scanner

    NASA Astrophysics Data System (ADS)

    Yao, Rutao; Ramachandra, Ranjith M.; Panse, Ashish; Balla, Deepika; Yan, Jianhua; Carson, Richard E.

    2010-04-01

    We previously designed a component based 3-D PSF model to obtain a compact yet accurate system matrix for a dedicated human brain PET scanner. In this work, we adapted the model to a small animal PET scanner. Based on the model, we derived the system matrix for back-to-back gamma source in air, fluorine-18 and iodine-124 source in water by Monte Carlo simulation. The characteristics of the PSF model were evaluated and the performance of the newly derived system matrix was assessed by comparing its reconstructed images with the established reconstruction program provided on the animal PET scanner. The new system matrix showed strong PSF dependency on the line-of-response (LOR) incident angle and LOR depth. This confirmed the validity of the two components selected for the model. The effect of positron range on the system matrix was observed by comparing the PSFs of different isotopes. A simulated and an experimental hot-rod phantom study showed that the reconstruction with the proposed system matrix achieved better resolution recovery as compared to the algorithm provided by the manufacturer. Quantitative evaluation also showed better convergence to the expected contrast value at similar noise level. In conclusion, it has been shown that the system matrix derivation method is applicable to the animal PET system studied, suggesting that the method may be used for other PET systems and different isotope applications.

  8. Monte Carlo simulations versus experimental measurements in a small animal PET system. A comparison in the NEMA NU 4-2008 framework

    NASA Astrophysics Data System (ADS)

    Popota, F. D.; Aguiar, P.; España, S.; Lois, C.; Udias, J. M.; Ros, D.; Pavia, J.; Gispert, J. D.

    2015-01-01

    In this work a comparison between experimental and simulated data using GATE and PeneloPET Monte Carlo simulation packages is presented. All simulated setups, as well as the experimental measurements, followed exactly the guidelines of the NEMA NU 4-2008 standards using the microPET R4 scanner. The comparison was focused on spatial resolution, sensitivity, scatter fraction and counting rates performance. Both GATE and PeneloPET showed reasonable agreement for the spatial resolution when compared to experimental measurements, although they lead to slight underestimations for the points close to the edge. High accuracy was obtained between experiments and simulations of the system’s sensitivity and scatter fraction for an energy window of 350-650 keV, as well as for the counting rate simulations. The latter was the most complicated test to perform since each code demands different specifications for the characterization of the system’s dead time. Although simulated and experimental results were in excellent agreement for both simulation codes, PeneloPET demanded more information about the behavior of the real data acquisition system. To our knowledge, this constitutes the first validation of these Monte Carlo codes for the full NEMA NU 4-2008 standards for small animal PET imaging systems.

  9. Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) Correlation of Histopathology and MRI in Prion Disease.

    PubMed

    Mente, Karin P; O'Donnell, James K; Jones, Stephen E; Cohen, Mark L; Thompson, Nicolas R; Bizzi, Alberto; Gambetti, Pierluigi; Safar, Jiri G; Appleby, Brian S

    2017-01-01

    Creutzfeldt-Jakob disease (CJD) and other prion diseases are rapidly progressive spongiform encephalopathies that are invariably fatal. Clinical features and magnetic resonance imaging, electroencephalogram, and cerebrospinal fluid abnormalities may suggest prion disease, but a definitive diagnosis can only be made by means of neuropathologic examination. Fluorodeoxyglucose positron emission tomography (FDG-PET) is not routinely used to evaluate patients with suspected prion disease. This study includes 11 cases of definite prion disease in which FDG-PET scans were obtained. There were 8 sporadic CJD cases, 2 genetic CJD cases, and 1 fatal familial insomnia case. Automated FDG-PET analysis revealed parietal region hypometabolism in all cases. Surprisingly, limbic and mesolimbic hypermetabolism were also present in the majority of cases. When FDG-PET hypometabolism was compared with neuropathologic changes (neuronal loss, astrocytosis, spongiosis), hypometabolism was predictive of neuropathology in 80.6% of cortical regions versus 17.6% of subcortical regions. The odds of neuropathologic changes were 2.1 times higher in cortical regions than subcortical regions (P=0.0265). A similar discordance between cortical and subcortical regions was observed between FDG-PET hypometabolism and magnetic resonance imaging diffusion weighted imaging hyperintensity. This study shows that there may be a relationship between FDG-PET hypometabolism and neuropathology in cortical regions in prion disease but it is unlikely to be helpful for diagnosis.

  10. Impact of PET-FDG in the diagnosis and therapeutic care of patients presenting with metastases of unknown primary.

    PubMed

    Garin, Etienne; Prigent-Lejeune, Florence; Lesimple, Thierry; Barge, Marie-Luce; Rousseau, Caroline; Devillers, Anne; Bouriel, Catherine; Habiba, Mesbah T; Bernard, Anne-Marie; Bridji, Boumédienne; Resche, Isabelle

    2007-06-01

    We carried out a study to evaluate the contribution of positron emission tomography with (18)F-fluorodeoxyglucose (PET-FDG) in the diagnosis and therapeutic care of patients presenting with metastases of unknown primary. PET-FDG was prospectively performed in 51 patients. The PET-FDG data were confirmed histologically or by a follow-up on average at 13 months. PET-FDG identified the primary in 24 percent of cases, and detected the presence of additional metastases in 41 percent of cases. PET-FDG led to a therapeutic modification for 12 patients (24 percent). Furthermore, the therapeutic impact seems more marked in localized forms than in the multifocal. This broad exploratory study confirms the important role of PET-FDG in the diagnosis and therapeutic management of patients with metastases of unknown primary.

  11. F18-FDG coincidence-PET in patients with suspected gynecological malignancy.

    PubMed

    Zor, E; Stokkel, M P; Ozalp, S; Vardareli, E; Yalçin, O Tarik; Ak, I

    2006-07-01

    To assess the role of F18-FDG imaging with a dual-head coincidence mode gamma camera (Co-PET) in identifying malignant tumors in patients with a suspicious adnexal mass depicted by conventional imaging methods. F18-FDG Co-PET was performed preoperatively in 18 women (mean age 56.38 years) with suspected malignant gynecologic tumors according to clinical and abdomino-pelvic/transvaginal ultrasound or computed tomography findings. Exploratory laparotomy was performed in all patients within the 10 days post-F18-FDG Co-PET study, and the definitive diagnosis of the adnexal masses was established by histopathological examination. Histopathological examinations of the surgically excised adnexal masses revealed eight malignant, one borderline, and nine benign neoplastic tumors. Four benign tumors had no F18-FDG uptake, while the remaining five tumors, all leiomyomas, showed mild FDG accumulation. Eight malignant tumors showed intense F18-FDG uptake. Sensitivity, specificity, PPV, and NPV of F18-FDG co-PET in differentiating benign from malign adnexal masses were 88%, 44%, 61%, and 80%, respectively. Tumor to background ratios (T/B) in benign lesions (2.04 +/- 0.27) were significantly lower than in malignant lesions (7.4 +/- 0.99). F18-FDG Co-PET is of clinical value when assessing suspicious malignant adnexal masses. False-negative F18-FDG results might arise from borderline disease. Moderate F18-FDG uptake in leiomyomas can result false-positive, but T/B ratios may be helpful in such cases.

  12. Addition of 18F-FDG-PET scans to radiotherapy planning of thoracic lymphoma.

    PubMed

    Lee, Young K; Cook, Gary; Flower, Maggie A; Rowbottom, Carl; Shahidi, Mehdi; Sharma, Bhupinder; Webb, Steve

    2004-12-01

    FDG-PET possesses greater sensitivity and accuracy than computed tomography (CT) in detecting diseased lymph nodes. Though the FDG-PET scans are acquired for similar diagnostic reasons as CT, they are not used in the radiotherapy (RT) planning process. Successful tumourcidal dose is usually delivered but large volumes of normal and non-malignant tissues are irradiated due to the nature of lymphoma and also to the subjectivity of the field determining process. This study tries to lessen the subjectivity of the field determining process by the addition of currently acquired PET to the conventional thoracic lymphoma RT. The differences between retrospectively delineated volumes from CT and FDG-PET were compared and the effect of this additional information was evaluated. Seventeen FDG-PET scans were registered to corresponding CT scans using rigid-body registration with negligible intra-observer variability. Comparisons were made between the volumes, lateral extensions and the most inferior point of the delineated gross tumour volumes (GTVs). For 1/17 patient data, no diseased volumes were delineated and in 6/17, no volumes were delineated on PET and yet in CT, masses up to 367.2 cm3 were outlined. From the 10 positive-CT and PET data, the GTV(PET) were smaller than GTV(CT) in six cases. Greater than 3.0 cm lateral disease extension differences were observed in 4/10 cases. Inferior tumour extents were confirmed in 6/10 cases whereas in 2/10 patients GTV(CT) was greater than 12.0 cm inferior compared to GTV(PET). FDG-PET data can be introduced to current thoracic lymphoma RT planning protocol with minimal intervention and changes. The subjectivity in the RT planning of thoracic lymphoma would be decreased with the addition of currently acquired FDG-PET data.

  13. Prognostic value of interim and end-of-treatment FDG-PET in follicular lymphoma: a systematic review.

    PubMed

    Adams, Hugo J A; Nievelstein, Rutger A J; Kwee, Thomas C

    2016-01-01

    This study aimed to systematically review the prognostic value of interim and end-of-treatment (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in follicular lymphoma during and after first-line therapy. The PubMed/MEDLINE database was searched for relevant original studies. Included studies were methodologically assessed, and their results were extracted and descriptively analyzed. Three studies on the prognostic value of interim FDG-PET and eight studies on the prognostic value of end-of-treatment FDG-PET were included. Overall, studies were of poor methodological quality. In addition, there was incomplete reporting of progression-free survival (PFS) and overall survival (OS) data by several studies, and none of the studies incorporated the Follicular Lymphoma International Prognostic Index (FLIPI) in the OS analyses. Two studies reported no significant difference in PFS between interim FDG-PET positive and negative patients, whereas one study reported a significant difference in PFS between the two groups. Two studies reported no significant difference in OS between interim FDG-PET positive and negative patients. Five studies reported end-of-treatment FDG-PET positive patients to have a significantly worse PFS than end-of-treatment FDG-PET negative patients, and one study reported a non-significant trend towards a worse PFS for end-of-treatment FDG-PET positive patients. Three studies reported end-of-treatment FDG-PET positive patients to have a significantly worse OS than end-of-treatment FDG-PET negative patients. In conclusion, the available evidence does not support the use of interim FDG-PET in follicular lymphoma. Although published studies suggest end-of-treatment FDG-PET to be predictive of PFS and OS, they suffer from numerous biases and failure to correct OS prediction for the FLIPI.

  14. Role of (18)F-FDG PET/CT in patients affected by Langerhans cell histiocytosis.

    PubMed

    Albano, Domenico; Bosio, Giovanni; Giubbini, Raffaele; Bertagna, Francesco

    2017-07-26

    Langerhans cell histiocytosis (LCH) is a rare hematological disorder for which the utility of(18)F-FDG PET/CT is unclear. Our aim was to explore the metabolic features of LCH and the possible role of(18)F-FDG PET/CT in LCH evaluation. We found 17 patients with histologically proven LCH who underwent 17(18)F-FDG PET/CT scans for staging and 42 scans for restaging/follow-up purposes. PET/CT results were compared with those obtained from other conventional imaging modalities (bone scintigraphy, plain radiogram, computed tomography, magnetic resonance). (18)F-FDG PET/CT was positive in 15/17 patients, and it detected 36/37 lesions; all bone and extraskeletal lesions, except for a cecal lesion, were(18)F-FDG-avid. Only 1/4 of the patients with lung LCH had hypermetabolic lesions. The average SUVmax of the FDG-avid lesions was 7.3 ± 6.7, the average lesion-to-liver SUVmax ratio was 3.4 ± 2.5, and the average lesion-to-blood pool SUVmax ratio was 4 ± 3.2. In comparison to other imaging methods,(18)F-FDG PET/CT detected additional lesions or was able to evaluate treatment response earlier in 33/74 cases; it was confirmatory in 38/74 and detected fewer lesions in 3/74 (all three with lung LCH). (18)F-FDG PET/CT seems to be useful for evaluating LCH when compared to conventional imaging, except in pulmonary cases. It can be used both for staging and restaging purposes.

  15. Askin tumor: CT and FDG-PET/CT imaging findings and follow-up.

    PubMed

    Xia, Tingting; Guan, Yubao; Chen, Yongxin; Li, Jingxu

    2014-07-01

    The aim of the study was to describe the imaging findings of Askin tumors on computed tomography (CT) and fluorine 18 fluorodeoxyglucose-positron emission tomography (FDG-PET/CT).Seventeen cases of Askin tumors confirmed by histopathology were retrospectively analyzed in terms of CT (17 cases) and FDG-PET/CT data (6 cases).Fifteen of the tumors were located in the chest wall and the other 2 were in the anterior middle mediastinum. Of the 15 chest wall cases, 13 demonstrated irregular, heterogeneous soft tissue masses with cystic degeneration and necrosis, and 2 demonstrated homogeneous soft tissue masses on unenhanced CT scans. Two mediastinal tumors demonstrated the irregular, heterogeneous soft tissue masses. Calcifications were found in 2 tumors. The tumors demonstrated heterogeneously enhancement in 16 cases and homogeneous enhancement in 1 case on contrast-enhanced scans. FDG-PET/CT images revealed increased metabolic activity in all 6 cases undergone FDG-PET/CT scan, and the lesion SUVmax ranged from 4.0 to 18.6. At initial diagnosis, CT and FDG-PET/CT scans revealed rib destruction in 9 cases, pleural effusion in 9 cases, and lung metastasis in 1 case. At follow-up, 12 cases showed recurrence and/or metastases, 4 cases showed improvement or remained stable, and 1 was lost to follow-up.In summary, CT and FDG-PET/CT images of Askin tumors showed heterogeneous soft tissue masses in the chest wall and the mediastinum, accompanied by rib destruction, pleural effusion, and increased FDG uptake. CT and FDG-PET/CT imaging play important roles in the diagnosis and follow-up of patients with Askin tumors.

  16. Food residue granuloma mimicking metastatic disease on FDG-PET/CT.

    PubMed

    Crucitti, Antonio; Grossi, Ugo; Leccisotti, Lucia; Maggi, Fabio; Ricci, Riccardo; Mazzari, Andrea; Tomaiuolo, Pasquina M C; Giordano, Alessandro

    2013-05-01

    A 31-year-old woman presenting with acute abdomen underwent an emergency Hartmann's procedure for fecal peritonitis due to perforated adenocarcinoma of the left colon. Shortly after a 7-month course of adjuvant chemotherapy, follow-up contrast-enhanced CT showed multiple peritoneal and hepatic nodules, showing focal intense and homogeneous FDG uptake on FDG-PET/CT, highly suspected for recurrence of disease. Excisional biopsy of the nodules revealed foreign body granulomas made up of alimentary materials surrounded by a fibrous wall. We report a unique case of a false-positive finding secondary to food residues mimicking metastatic disease on FDG-PET in a patient with colon cancer.

  17. Fluorodeoxyglucose positron emission tomography (FDG-PET) for monitoring lymphadenopathy in the autoimmune lymphoproliferative syndrome (ALPS).

    PubMed

    Rao, V Koneti; Carrasquillo, Jorge A; Dale, Janet K; Bacharach, Stephen L; Whatley, Millie; Dugan, Faith; Tretler, Jean; Fleisher, Thomas; Puck, Jennifer M; Wilson, Wyndham; Jaffe, Elaine S; Avila, Nilo; Chen, Clara C; Straus, Stephen E

    2006-02-01

    Autoimmune lymphoproliferative syndrome (ALPS) is associated with mutations that impair the activity of lymphocyte apoptosis proteins, leading to chronic lymphadenopathy, hepatosplenomegaly, autoimmunity, and an increased risk of lymphoma. We investigated the utility of fluorodeoxyglucose positron emission tomography (FDG-PET) in discriminating benign from malignant lymphadenopathy in ALPS. We report that FDG avidity of benign lymph nodes in ALPS can be high and, hence, by itself does not imply presence of lymphoma; but FDG-PET can help guide the decision for selecting which of many enlarged nodes in ALPS patients to biopsy when lymphoma is suspected.

  18. Development of a clear sub-millimeter small animal PET scanner by reducing the influence of the non-collinearity effect

    NASA Astrophysics Data System (ADS)

    Bolwin, K.; Vernekohl, D.; Lühder, J.; Czekalla, B.; Wessels, J. P.; Schäfers, K. P.

    2017-03-01

    Small animal PET plays a major role in studying molecular processes in vivo. However, the spatial resolution of small animal PET is limited by physical effects like positron range, photon non-collinearity, and object scattering. The aim of this project was to minimize the influence of the non-collinearity effect by reducing the distance between the coincidence detectors leading to an improved spatial resolution. A multi-wire proportional chamber-based high-resolution PET scanner (quadHIDAC) was used, offering a spatial resolution of nearly 1 mm FWHM. By removing two opposite detector banks of the 4-detector-setup, the inner distance between the two remaining detector plates could be reduced from 180 mm to 40 mm. List mode acquisitions of a small point source (22Na) experiment were performed, images were reconstructed (0.25 mm voxel size) using a one-pass list-mode EM algorithm and the FWHM in the radial, tangential, and axial directions was calculated. In addition, a Jaszczak phantom (hole sizes of 0.7 up to 1.2 mm) was acquired with both scanners. The prototype high-resolution PET scanner showed improved spatial resolution in radial (0.9 mm FWHM), tangential (0.9 mm FWHM), and axial (0.8 mm FWHM) direction compared to the quadHIDAC scanner (1.x mm, 1.x mm, 1.x mm), respectively offering clear sub-millimeter imaging. Blurring effects due to photon non-collinearity could be reduced by minimizing the detector distance.

  19. Post-PET ultrasound improves specificity of 18F-FDG-PET for recurrent differentiated thyroid cancer while maintaining sensitivity.

    PubMed

    Biermann, Martin; Kråkenes, Jostein; Brauckhoff, Katrin; Haugland, Hans Kristian; Heinecke, Achim; Akslen, Lars A; Varhaug, Jan Erik; Brauckhoff, Michael

    2015-11-01

    Positron emission tomography (PET) using fluor-18-deoxyglucose (18F-FDG) with or without computed tomography (CT) is generally accepted as the most sensitive imaging modality for diagnosing recurrent differentiated thyroid cancer (DTC) in patients with negative whole body scintigraphy with iodine-131 (I-131). To assess the potential incremental value of ultrasound (US) over 18F-FDG-PET-CT. Fifty-one consecutive patients with suspected recurrent DTC were prospectively evaluated using the following multimodal imaging protocol: (i) US before PET (pre-US) with or without fine needle biopsy (FNB) of suspicious lesions; (ii) single photon emission computed tomography (≥3 GBq I-131) with co-registered CT (SPECT-CT); (iii) 18F-FDG-PET with co-registered contrast-enhanced CT of the neck; (iv) US in correlation with the other imaging modalities (post-US). Postoperative histology, FNB, and long-term follow-up (median, 2.8 years) were taken as composite gold standard. Fifty-eight malignant lesions were identified in 34 patients. Forty lesions were located in the neck or upper mediastinum. On receiver operating characteristics (ROC) analysis, 18F-FDG-PET had a limited lesion-based specificity of 59% at a set sensitivity of 90%. Pre-US had poor sensitivity and specificity of 52% and 53%, respectively, increasing to 85% and 94% on post-US, with knowledge of the PET/CT findings (P < 0.05 vs. PET and pre-US). Multimodal imaging changed therapy in 15 out of 51 patients (30%). In patients with suspected recurrent DTC, supplemental targeted US in addition to 18F-FDG-PET-CT increases specificity while maintainin sensitivity, as non-malignant FDG uptake in cervical lesions can be confirmed. © The Foundation Acta Radiologica 2015.

  20. Value of 18F-FDG PET and PET/CT for evaluation of pediatric malignancies.

    PubMed

    Uslu, Lebriz; Donig, Jessica; Link, Michael; Rosenberg, Jarrett; Quon, Andrew; Daldrup-Link, Heike E

    2015-02-01

    Successful management of solid tumors in children requires imaging tests for accurate disease detection, characterization, and treatment monitoring. Technologic developments aim toward the creation of integrated imaging approaches that provide a comprehensive diagnosis with a single visit. These integrated diagnostic tests not only are convenient for young patients but also save direct and indirect health-care costs by streamlining procedures, minimizing hospitalizations, and minimizing lost school or work time for children and their parents. (18)F-FDG PET/CT is a highly sensitive and specific imaging modality for whole-body evaluation of pediatric malignancies. However, recent concerns about ionizing radiation exposure have led to a search for alternative imaging methods, such as whole-body MR imaging and PET/MR. As we develop new approaches for tumor staging, it is important to understand current benchmarks. This review article will synthesize the current literature on (18)F-FDG PET/CT for tumor staging in children, summarizing questions that have been solved and providing an outlook on unsolved avenues.

  1. Poor predictive value of positive interim FDG-PET/CT in primary mediastinal large B-cell lymphoma.

    PubMed

    Lazarovici, Julien; Terroir, Marie; Arfi-Rouche, Julia; Michot, Jean-Marie; Mussot, Sacha; Florea, Valentina; Ghigna, Maria-Rosa; Dartigues, Peggy; Petrovanu, Cynthia; Danu, Alina; Fermé, Christophe; Ribrag, Vincent; Ghez, David

    2017-06-21

    Though commonly used to assess response to therapy, the prognostic value of interim FDG-PET/CT in Primary Mediastinal Large B-cell Lymphoma (PMBCL) is unclear. We conducted a retrospective study on 36 consecutive patients treated at our institution for a PMBCL between 2006 and 2014. All patients with a positive interim FDG-PET/CT had undergone histological restaging consisting either in a surgical debulking of the residual lesion (15 patients) or a CT-guided core needle biopsy (two patients). All FDG-PET/CT were secondarily reviewed according to the more recent Deauville criteria. Interim FDG-PET/CT was considered positive in 17/36 patients using visual evaluation. Among these patients, 14 had a Deauville score of 4. Histological restaging was negative in all but one case, showing inflammation and/or fibrosis. After a median follow-up of 48.5 months, a total of five patients have relapsed, two patients in the positive FDG-PET/CT group, and three patients in the negative FDG-PET/CT group, respectively. These data indicate that a positive interim FDG-PET/CT does not reflect persistence of active disease in the vast majority of PMBCL cases. The relapse rate appears similar regardless of interim FDG-PET/CT results and interpretation criteria. This suggests that interim FDG-PET/CT has a poor positive predictive value, thus kt should be used with caution in PMBCL.

  2. The Value of FDG PET/CT in Treatment Response Assessment, Follow-Up, and Surveillance of Lung Cancer.

    PubMed

    Sheikhbahaei, Sara; Mena, Esther; Yanamadala, Anusha; Reddy, Siddaling; Solnes, Lilja B; Wachsmann, Jason; Subramaniam, Rathan M

    2017-02-01

    The purpose of this article is to summarize the evidence regarding the role of FDG PET/CT in treatment response assessment and surveillance of lung cancer and to provide suggested best practices. FDG PET/CT is a valuable imaging tool for assessing treatment response for patients with lung cancer, though evidence for its comparative effectiveness with chest CT is still evolving. FDG PET/CT is most useful when there is clinical suspicion or other evidence for disease recurrence or metastases. The sequencing, cost analysis, and comparative effectiveness of FDG PET/CT and conventional imaging modalities in the follow-up setting need to be investigated.

  3. FDG-PET probe-guided surgery for recurrent retroperitoneal testicular tumor recurrences.

    PubMed

    de Jong, J S; van Ginkel, R J; Slart, R H J A; Lemstra, C L; Paans, A M J; Mulder, N H; Hoekstra, H J

    2010-11-01

    Tumor marker based recurrences of previously treated testicular cancer are generally detected with CT scan. They sometimes cannot be visualized with conventional morphologic imaging. FDG-PET has the ability to detect these recurrences. PET probe-guided surgery, may facilitate the extent of surgery and optimize the surgical resection. Three patients with resectable 2nd or 3rd recurrent testicular cancer based on elevated tumor markers after previous various chemotherapy schedules and resections of residual retroperitoneal tumor masses were included in this study. A diagnostic FDG-PET was performed and a hotspot in previously operated area of the retroperitoneal space in all three patients was visualized. PET probe-guided surgery was performed using a high-energy gamma probe 3 h post-injection of 500 MBq FDG. All patients showed extended adhesions and scar tissue in the retroperitoneal area due to the previous surgeries. Pre-operative PET/CT scan showed a good correlation with intra-operative PET probe-guided detection of recurrent lesions. There was a high target to background ratio (TGB) of 5:1 during the procedure. In one patient, a 2 cm large lesion, which did not show on pre-operative FDG-PET scan, was detected with the PET probe. Histopathologic tissue evaluation demonstrated recurrent vital tumor in all PET probe positive lesions. PET probe-guided surgery seems to be a promising tool to localize FDG-PET positive lesion in recurrent testicular cancer in hardly accessible surgical locations. PET probe-guided surgery might be a useful technique in surgical oncology for recurrent testicular cancer and has the potential to be applied in surgery of other malignant diseases. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Emerging role of FDG-PET/CT in assessing atherosclerosis in large arteries.

    PubMed

    Chen, Wengen; Bural, Gonca G; Torigian, Drew A; Rader, Daniel J; Alavi, Abass

    2009-01-01

    Atherosclerosis is a dynamic inflammatory disorder. The biological composition and inflammatory state of an atherosclerotic plaque, rather than the degree of stenosis or its size are the major determinants of acute clinical events. A noninvasive technique to detect vulnerable atherosclerotic plaque is critically needed. FDG-PET/CT, a combined functional and structural whole-body imaging modality, holds great potential for this purpose. FDG uptake in large arteries has been frequently observed and is associated with cardiovascular risk factors. FDG accumulates in plaque macrophages and uptake is correlated with macrophage density. It is known that vascular FDG uptake and calcification do not overlap significantly and changes of FDG uptake are common, suggesting that FDG uptake may represent a dynamic inflammatory process. It has been reported that vascular FDG uptake can be attenuated by simvastatin in patients, and by the antiinflammatory drug probucol in rabbits. Vascular FDG uptake has been linked to cardiovascular events in some preliminary studies. Data from basic sciences, and animal and clinical studies support the emerging role of FDG-PET/CT in assessing atherosclerosis in large arteries in humans.

  5. Clinical utility and limitations of FDG PET in detecting recurrent hepatocellular carcinoma in postoperative patients.

    PubMed

    Hayakawa, Nobuyuki; Nakamoto, Yuji; Nakatani, Koya; Hatano, Etsuro; Seo, Satoru; Higashi, Tatsuya; Saga, Tsuneo; Uemoto, Shinji; Togashi, Kaori

    2014-12-01

    The clinical usefulness of positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) for the detection of recurrent hepatocellular carcinoma (HCC) is controversial because HCC displays varying FDG avidity. The purposes of this study were to re-evaluate the utility of FDG PET for the detection of recurrent HCC, and to assess its prognostic value in a large series of postoperative patients. We retrospectively reviewed 113 scans in 86 patients undergoing FDG PET after curative surgery for HCC. These scans were performed for suspected recurrence on radiologic imaging (group A: n = 44) because of an elevated tumor marker level with negative prior imaging results (group B: n = 32) or with no suspicion of recurrence (group C: n = 37). FDG PET's accuracy for recurrence detection and its value as a predictor of survival were assessed. The sensitivity, specificity, and diagnostic accuracy were 53, 100, and 55 % for group A; 34, 100, and 41 % for group B; and 11, 100, and 78 % for group C, respectively. A change in therapy resulted from the scan results in 7, 9, and 8 % in groups A, B, and C, respectively. The combined sensitivities for intra- and extrahepatic recurrence were 30 and 42 %, respectively. Histopathological features at initial surgery did not affect the sensitivity. The overall survival of patients with positive scans was significantly poorer than that of patients with negative scans (P = 0.008). The sensitivity of FDG PET for recurrent HCC was low, with little change in treatment resulting. However, it can predict prognosis in postoperative patients.

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

    PubMed

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

    2014-12-01

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

  7. Choline molecular imaging with small-animal PET for monitoring tumor cellular response to photodynamic therapy of cancer

    NASA Astrophysics Data System (ADS)

    Fei, Baowei; Wang, Hesheng; Wu, Chunying; Meyers, Joseph; Xue, Liang-Yan; MacLennan, Gregory; Schluchter, Mark

    2009-02-01

    We are developing and evaluating choline molecular imaging with positron emission tomography (PET) for monitoring tumor response to photodynamic therapy (PDT) in animal models. Human prostate cancer (PC-3) was studied in athymic nude mice. A second-generation photosensitizer Pc 4 was used for PDT in tumor-bearing mice. MicroPET images with 11C-choline were acquired before PDT and 48 h after PDT. Time-activity curves of 11C-choline uptake were analyzed before and after PDT. For treated tumors, normalized choline uptake decreased significantly 48 h after PDT, compared to the same tumors pre-PDT (p <~ 0.001). However, for the control tumors, normalized choline uptake increased significantly (p <~ 0.001). PET imaging with 11C-choline is sensitive to detect early tumor response to PDT in the animal model of human prostate cancer.

  8. Benefits of respiratory-gated 18F-FDG PET acquisition in lung disease.

    PubMed

    Bailly, Pascal; Bouzerar, Roger; Shields, Trevor; Meyer, Marc-Etienne; Daouk, Joël

    2017-10-03

    Fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) is a reliable imaging modality for the diagnosis of malignant lung nodules and to assess the latter's prognosis. However, physiological respiratory motion deteriorates PET images and thus decreases the technique's diagnostic and prognostic values. This issue can be overcome by applying respiratory gating to the F-FDG PET/CT acquisitions. The aim of this study was to evaluate the ability of respiratory-gated F-FDG PET/CT to diagnose malignant lung nodules and to predict recurrence and patient survival. A total of 103 prospectively enrolled patients with solid lung nodules underwent both ungated and gated F-FDG PET/CT acquisitions. The maximum standardized uptake value (SUVmax) was used to differentiate benign from malignant nodules. Patients have been followed up for at least 36 months to confirm imaging results and assess survival. Gated F-FDG PET/CT was significantly more sensitive than ungated PET/CT for the diagnosis of malignant lung nodules located in the lower lobes (92 vs. 58%; P<0.001) and in patients aged older than 60 years (73 vs. 48%; P<0.001). The same gain was observed for stage I cancers with tumors from 10 to 20 mm. When considering patients aged older than 60 years, those with a low SUVmax on gated PET images had a significantly higher 3-year disease-free survival rate than those with a high SUVmax (76 vs. 47%; P=0.03). F-FDG PET/CT is advisable for the assessment of lung nodules in patients aged older than 60 years and/or in the lower lobes.

  9. Comparison of CE-FDG-PET/CT with CE-FDG-PET/MR in the evaluation of osseous metastases in breast cancer patients

    PubMed Central

    Catalano, O A; Nicolai, E; Rosen, B R; Luongo, A; Catalano, M; Iannace, C; Guimaraes, A; Vangel, M G; Mahmood, U; Soricelli, A; Salvatore, M

    2015-01-01

    Background: Despite improvements in treatments, metastatic breast cancer remains difficult to cure. Bones constitute the most common site of first-time recurrence, occurring in 40–75% of cases. Therefore, evaluation for possible osseous metastases is crucial. Technetium 99 (99Tc) bone scintigraphy and fluorodexossyglucose (FDG) positron emission tomography (PET)-computed tomography (PET-CT) are the most commonly used techniques to assess osseous metastasis. PET magnetic resonance (PET-MR) imaging is an innovative technique still under investigation. We compared the capability of PET-MR to that of same-day PET-CT to assess osseous metastases in patients with breast cancer. Methods: One hundred and nine patients with breast cancer, who underwent same-day contrast enhanced (CE)-PET-CT and CE-PET-MR, were evaluated. CE-PET-CT and CE-PET-MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Binomial confidence intervals and a χ2 test were used for categorical data, and paired t-test was used for the SUVmax data; a non-informative prior Bayesian approach was used to estimate and compare the specificities. Results: Osseous metastases affected 25 out 109 patients. Metastases were demonstrated by CE-PET-CT in 22 out of 25 patients (88%±7%), and by CE-PET-MR in 25 out of 25 patients (100%). CE-PET-CT revealed 90 osseous metastases and CE-PET-MR revealed 141 osseous metastases (P<0.001). The estimated sensitivity of CE-PET-CT and CE-PET-MR were 0.8519 and 0.9630, respectively. The estimated specificity for CE-FDG-PET-MR was 0.9884. The specificity of CE-PET-CT cannot be determined from patient-level data, because CE-PET-CT yielded a false-positive lesion in a patient who also had other, true metastases. Conclusions: CE-PET-MR detected a higher number of osseous metastases than did same-day CE-PET-CT, and was positive for 12% of the patients

  10. Comparison of CE-FDG-PET/CT with CE-FDG-PET/MR in the evaluation of osseous metastases in breast cancer patients.

    PubMed

    Catalano, O A; Nicolai, E; Rosen, B R; Luongo, A; Catalano, M; Iannace, C; Guimaraes, A; Vangel, M G; Mahmood, U; Soricelli, A; Salvatore, M

    2015-04-28

    Despite improvements in treatments, metastatic breast cancer remains difficult to cure. Bones constitute the most common site of first-time recurrence, occurring in 40-75% of cases. Therefore, evaluation for possible osseous metastases is crucial. Technetium 99 ((99)Tc) bone scintigraphy and fluorodexossyglucose (FDG) positron emission tomography (PET)-computed tomography (PET-CT) are the most commonly used techniques to assess osseous metastasis. PET magnetic resonance (PET-MR) imaging is an innovative technique still under investigation. We compared the capability of PET-MR to that of same-day PET-CT to assess osseous metastases in patients with breast cancer. One hundred and nine patients with breast cancer, who underwent same-day contrast enhanced (CE)-PET-CT and CE-PET-MR, were evaluated. CE-PET-CT and CE-PET-MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Binomial confidence intervals and a χ(2) test were used for categorical data, and paired t-test was used for the SUVmax data; a non-informative prior Bayesian approach was used to estimate and compare the specificities. Osseous metastases affected 25 out 109 patients. Metastases were demonstrated by CE-PET-CT in 22 out of 25 patients (88%±7%), and by CE-PET-MR in 25 out of 25 patients (100%). CE-PET-CT revealed 90 osseous metastases and CE-PET-MR revealed 141 osseous metastases (P<0.001). The estimated sensitivity of CE-PET-CT and CE-PET-MR were 0.8519 and 0.9630, respectively. The estimated specificity for CE-FDG-PET-MR was 0.9884. The specificity of CE-PET-CT cannot be determined from patient-level data, because CE-PET-CT yielded a false-positive lesion in a patient who also had other, true metastases. CE-PET-MR detected a higher number of osseous metastases than did same-day CE-PET-CT, and was positive for 12% of the patients deemed osseous metastasis-negative on the

  11. Systematic analysis of 18F-FDG PET and metabolism, proliferation and hypoxia markers for classification of head and neck tumors

    PubMed Central

    2014-01-01

    Background Quantification of molecular cell processes is important for prognostication and treatment individualization of head and neck cancer (HNC). However, individual tumor comparison can show discord in upregulation similarities when analyzing multiple biological mechanisms. Elaborate tumor characterization, integrating multiple pathways reflecting intrinsic and microenvironmental properties, may be beneficial to group most uniform tumors for treatment modification schemes. The goal of this study was to systematically analyze if immunohistochemical (IHC) assessment of molecular markers, involved in treatment resistance, and 18F-FDG PET parameters could accurately distinguish separate HNC tumors. Methods Several imaging parameters and texture features for 18F-FDG small-animal PET and immunohistochemical markers related to metabolism, hypoxia, proliferation and tumor blood perfusion were assessed within groups of BALB/c nu/nu mice xenografted with 14 human HNC models. Classification methods were used to predict tumor line based on sets of parameters. Results We found that 18F-FDG PET could not differentiate between the tumor lines. On the contrary, combined IHC parameters could accurately allocate individual tumors to the correct model. From 9 analyzed IHC parameters, a cluster of 6 random parameters already classified 70.3% correctly. Combining all PET/IHC characteristics resulted in the highest tumor line classification accuracy (81.0%; cross validation 82.0%), which was just 2.2% higher (p = 5.2×10-32) than the performance of the IHC parameter/feature based model. Conclusions With a select set of IHC markers representing cellular processes of metabolism, proliferation, hypoxia and perfusion, one can reliably distinguish between HNC tumor lines. Addition of 18F-FDG PET improves classification accuracy of IHC to a significant yet minor degree. These results may form a basis for development of tumor characterization models for treatment allocation purposes

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

    PubMed

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

    2012-01-01

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

  13. Differential Diagnosis of Neurodegenerative Dementias Using Metabolic Phenotypes on F-18 FDG PET/CT

    PubMed Central

    Tripathi, Madhavi; Tripathi, Manjari; Damle, Nishikant; Kushwaha, Suman; Jaimini, Abhinav; D’Souza, Maria M.; Sharma, Rajnish; Saw, Sanjiv; Mondal, Anupam

    2014-01-01

    Summary Positron emission tomography (PET) imaging with F-18 fluorodeoxyglucose (FDG) can be used as a downstream marker of neuronal injury, a hallmark of neurodegenerative dementias. Characteristic patterns of regional glucose metabolism have been used to classify the dementia subtypes, namely Alzheimer's dementia (AD), frontotemporal dementia (FTD), diffuse Lewy body (DLBD) and vascular dementia (VD). We undertook this study to assess the utility of FDG-PET in the differential diagnosis of dementia subtypes. One hundred and twenty-five patients diagnosed with dementia were referred from cognitive disorders and memory clinics of speciality neurology centres for the FDG-PET study. Imaging-based diagnosis of dementia type was established in 101 patients by visual assessment of individual scans by a PET physician blinded to the clinical diagnosis. The results were compared with an 18-month follow-up clinical assessment made by the specialist neurologist. Concordance of visual evaluation of FDG-PET scans with clinical diagnosis of the dementia type was achieved in 90% of patients scanned. This concordance was 93.4% for AD, 88.8% for FTD, 66.6% for DLBD and 92.3% for the other dementia syndromes. FDG-PET performed after the initial work-up of dementias is useful for supporting the clinical diagnosis of dementia subtype. PMID:24571830

  14. FDG PET/CT dataset for navigation on femoral bone: a feasibility study.

    PubMed

    Militz, Matthias; Uhde, Jörg; Christian, Georg; Linke, Rainer; Morgenstern, Mario; Hungerer, Sven

    2015-12-01

    FDG PET/CT has become a valuable tool in the diagnosis of the activity of chronic osteomyelitis. The surgical strategy in the treatment of chronic osteomyelitis is the identification of the bone focus and radical debridement of sequesters. The aim of the current study was the registration and use of the FDG PET/CT imaging datasets on a navigation system to provide diagnostic imaging based feedback during surgical procedures. For the present study, FDG PET/CT scans were acquired from artificial bones and cadaver bones with a local focus of activity. The DICOM data sets were merged using a navigation system. The referenced regions of interest were matched with fluoroscopic pictures to register the PET/CT DICOM datasets to the bone and direct visual control. Navigated targeting led to accurate results when verified with fluoroscopic images by targeting previously inserted reference points in artificial and cadaver bone. FDG PET/CT datasets are suitable for navigation and compatible with conventional planning and navigation software. The combination of diagnostic FDG PET/CT imaging with surgical navigation techniques could be a valuable tool for the accurate treatment of chronic osteomyelitis.

  15. 18F-FDG-PET/CT in fever of unknown origin: clinical value.

    PubMed

    Buch-Olsen, Karen M; Andersen, Rikke V; Hess, Søren; Braad, Poul-Erik; Schifter, Søren

    2014-09-01

    Fever of unknown origin continues to be a diagnostic challenge for clinicians. The aim of this study was to confirm whether (18)F-fluorodeoxyglucose ((18)F-FDG)-PET/computed tomography (CT) is a helpful tool in patients suffering from this condition. Fifty-seven patients with fever of unknown origin were examined with (18)F-FDG-PET/CT as part of their diagnostic workup at the clinicians' discretion. The medical records were read retrospectively to establish the final diagnosis and evaluate the degree to which PET/CT contributed to the diagnosis. The examination was considered helpful if it corresponded to the final diagnosis by showing uptake in an organ considered responsible for the condition, or if it was without focal findings, thereby excluding the patient from having focal infection or malignancy. It was perceived false positive if it pointed towards an organ not regarded by the clinicians as being related to the final diagnosis. It was perceived not helpful if the cause of fever was not visible on (18)F-FDG-PET/CT. We found (18)F-FDG-PET/CT helpful in 75% of patients, not helpful in 4%, and false positive in 21% of patients. (18)F-FDG-PET/CT is a useful tool in the investigation of fever of unknown origin; it can reduce patient inconvenience and possibly costs to society if used earlier in the diagnostic process.

  16. Progressive osteoblastic bone metastases in breast cancer negative on FDG-PET.

    PubMed

    Huyge, Valérie; Garcia, Camilo; Vanderstappen, Anja; Alexiou, Jean; Gil, Thierry; Flamen, Patrick

    2009-07-01

    Positron emission tomography using F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is increasingly used in breast cancer. The new generation cameras integrate PET and CT within the same camera, allowing the simultaneous assessment of the structural and metabolic aspects of disease. There is presently a controversy on the clinical significance of osteoblastic bone metastases in breast cancer which are not detected on FDG-PET. It has been suggested that these radiologically dense lesions represent the result of successful treatment of initially osteolytic lesions. We report a case of a 65-year-old woman with a suspicion of recurrent breast cancer based on an increasing serum tumor marker. Serial PET/CT showed progressive blastic bone metastases on the CT without FDG uptake. These lesions were confirmed by bone single photon emission computed tomography. This case report shows: first, that progressive osteoblastic lesions can lack FDG-avidity, leading to a false-negative PET; and secondly, that bone scintigraphy should not be replaced by FDG-PET/CT for the detection of bone metastases in breast cancer.

  17. FDG-PET/CT for differentiating between aseptic and septic delayed union in the lower extremity.

    PubMed

    van Vliet, Kirsten E; de Jong, Vincent M; Termaat, M Frank; Schepers, Tim; van Eck-Smit, Berthe L F; Goslings, J Carel; Schep, Niels W L

    2017-09-27

    (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) has proven to have a high diagnostic accuracy for the detection of bone infections. In patients with delayed union it may be clinically important to differentiate between aseptic and septic delayed union. The aim of this study was to evaluate the efficacy and to assess the optimal diagnostic accuracy of FDG-PET/CT in differentiating between aseptic and septic delayed union in the lower extremity. This is a retrospective study of consecutive patients who underwent FDG-PET/CT scanning for suspicion of septic delayed union of the lower extremity. Diagnosis of aseptic delayed union or septic delayed union was made based on surgical deep cultures following PET/CT scanning and information on clinical follow-up. FDG-uptake values were measured at the fractured site by use of the maximum standardized uptake value (SUVmax). Sensitivity, specificity and diagnostic accuracy of FDG-PET/CT were calculated at various SUVmax cut-off points. A total of 30 patients were included; 13 patients with aseptic delayed unions and 17 patients with septic delayed unions. Mean SUVmax in aseptic delayed union patients was 3.23 (SD ± 1.21). Mean SUVmax in septic delayed union patients was 4.77 (SD ± 1.87). A cut-off SUVmax set at 4.0 showed sensitivity, specificity and diagnostic accuracy of FDG-PET/CT were 65, 77 and 70% to differentiate between aseptic and septic delayed union, respectively. Using a semi-quantitative measure (SUVmax) for interpretation of FDG-PET/CT imaging seems to be a promising tool for the discrimination between aseptic and septic delayed union.

  18. Practical utility of amyloid and FDG-PET in an academic dementia center

    PubMed Central

    Ghosh, Pia M.; Hagen, Jayne; Gesierich, Benno; Henry, Maya; Grinberg, Lea T.; O'Neil, James P.; Janabi, Mustafa; Huang, Eric J.; Trojanowski, John Q.; Vinters, Harry V.; Gorno-Tempini, Marilu; Seeley, William W.; Boxer, Adam L.; Rosen, Howard J.; Kramer, Joel H.; Miller, Bruce L.; Jagust, William J.; Rabinovici, Gil D.

    2014-01-01

    Objective: To evaluate the effect of amyloid imaging on clinical decision making. Methods: We conducted a retrospective analysis of 140 cognitively impaired patients (mean age 65.0 years, 46% primary β-amyloid (Aβ) diagnosis, mean Mini-Mental State Examination 22.3) who underwent amyloid (Pittsburgh compound B [PiB]) PET as part of observational research studies and were evaluated clinically before and after the scan. One hundred thirty-four concurrently underwent fluorodeoxyglucose (FDG)-PET. We assessed for changes between the pre- and post-PET clinical diagnosis (from Aβ to non-Aβ diagnosis or vice versa) and Alzheimer disease treatment plan. The association between PiB/FDG results and changes in management was evaluated using χ2 and multivariate logistic regression. Postmortem diagnosis was available for 24 patients (17%). Results: Concordance between scan results and baseline diagnosis was high (PiB 84%, FDG 82%). The primary diagnosis changed after PET in 13/140 patients (9%) overall but in 5/13 (38%) patients considered pre-PET diagnostic dilemmas. When examined independently, discordant PiB and discordant FDG were both associated with diagnostic change (unadjusted p < 0.0001). However, when examined together in a multivariate logistic regression, only discordant PiB remained significant (adjusted p = 0.00013). Changes in treatment were associated with discordant PiB in patients with non-Aβ diagnoses (adjusted p = 0.028), while FDG had no effect on therapy. Both PiB (96%) and FDG (91%) showed high agreement with autopsy diagnosis. Conclusions: PET had a moderate effect on clinical outcomes. Discordant PiB had a greater effect than discordant FDG, and influence on diagnosis was greater than on treatment. Prospective studies are needed to better characterize the clinical role of amyloid PET. PMID:24353340

  19. Cold wall effect eliminating method to determine the contrast recovery coefficient for small animal PET scanners using the NEMA NU-4 image quality phantom

    NASA Astrophysics Data System (ADS)

    Lajtos, Imre; Czernin, Johannes; Dahlbom, Magnus; Daver, Freddie; Emri, Miklos; Farshchi-Heydari, Salman; Forgacs, Attila; Hoh, Carl K.; Joszai, Istvan; Krizsan, Aron K.; Lantos, Judit; Major, Peter; Molnar, Jozsef; Opposits, Gabor; Tron, Lajos; Vera, David R.; Balkay, Laszlo

    2014-06-01

    The contrast recovery coefficients (CRC) were evaluated for five different small animal PET scanners: GE Explore Vista, Genisys4, MiniPET-2, nanoScan PC and Siemens Inveon. The NEMA NU-4 2008 performance test with the suggested image quality phantom (NU4IQ) does not allow the determination of the CRC values for the hot regions in the phantom. This drawback of NU4IQ phantom motivated us to develop a new method for this purpose. The method includes special acquisition and reconstruction protocols using the original phantom, and results in an artificially merged image enabling the evaluation of CRC values. An advantageous feature of this method is that it stops the cold wall effect from distorting the CRC calculation. Our suggested protocol results in a set of CRC values contributing to the characterization of small animal PET scanners. GATE simulations were also performed to validate the new method and verify the evaluated CRC values. We also demonstrated that the numerical values of this parameter depend on the actual object contrast of the hot region(s) and this mainly comes from the spillover effect. This effect was also studied while analysing the background activity level around the hot rods. We revealed that the calculated background mean values depended on the target contrast in a scanner specific manner. Performing the artificially merged imaging procedure and additional simulations using the micro hollow sphere (MHS) phantom geometry, we also proved that the inactive wall around the hot spheres can have a remarkable impact on the calculated CRC. In conclusion, we have shown that the proposed artificial merging procedure and the commonly used NU4IQ phantom prescribed by the NEMA NU-4 can easily deliver reliable CRC data otherwise unavailable for the NU4IQ phantom in the conventional protocol or the MHS phantom.

  20. Optimization of the scan protocols for CT-based material extraction in small animal PET/CT studies

    NASA Astrophysics Data System (ADS)

    Yang, Ching-Ching; Yu, Jhih-An; Yang, Bang-Hung; Wu, Tung-Hsin

    2013-12-01

    We investigated the effects of scan protocols on CT-based material extraction to minimize radiation dose while maintaining sufficient image information in small animal studies. The phantom simulation experiments were performed with the high dose (HD), medium dose (MD) and low dose (LD) protocols at 50, 70 and 80 kVp with varying mA s. The reconstructed CT images were segmented based on Hounsfield unit (HU)-physical density (ρ) calibration curves and the dual-energy CT-based (DECT) method. Compared to the (HU;ρ) method performed on CT images acquired with the 80 kVp HD protocol, a 2-fold improvement in segmentation accuracy and a 7.5-fold reduction in radiation dose were observed when the DECT method was performed on CT images acquired with the 50/80 kVp LD protocol, showing the possibility to reduce radiation dose while achieving high segmentation accuracy.

  1. FDG PET/CT detection of intussusception caused by lymphoma in a pediatric patient.

    PubMed

    Kang, Hye Jin; Beylergil, Volkan; Price, Anita P; Abramson, Sara J; Carrasquillo, Jorge A

    2014-01-01

    A previously healthy 9-year-old boy presented to an outside hospital with a history of abdominal pain and vomiting. An abdominal x-ray was unremarkable. A CT of the abdomen and pelvis performed to evaluate possible obstruction after weight loss and vomiting over a 3-week period demonstrated a large retroperitoneal mass. Laparoscopic biopsy showed diffuse large B-cell lymphoma. FDG PET/CT was performed for staging. An ileocolic intussusception was identified on the PET/CT. The intussusception was successfully managed with medical treatment. We present FDG PET/CT findings in intussusception with non-Hodgkin lymphoma as the lead point in a pediatric patient.

  2. FDG-PET or PET/CT in Fever of Unknown Origin: The Diagnostic Role of Underlying Primary Disease

    PubMed Central

    Ergül, Nurhan; Çermik, Tevfik Fikret

    2011-01-01

    Fever of unknown origin (FUO) is generally defined as a fever greater than 38.3°C on several occasions during a period longer than 3 weeks for which the etiology behind cannot be diagnosed at the end of at least 1 week hospital stay. Conventional diagnostic methods are still not adequate to reveal underlying reason in approximately 50% of patients with FUO. In patients with certain diagnosis, three major categories are infections, malignancies, and noninfectious inflammatory diseases. Fluoro-18-fluoro-2-deoxy-D-glucose (FDG) is a structural analog of 2-deoxyglucose and accumulates in malignant tissues but also at sites of infection and inflammation. For this reason, FDG PET or PET/CT has great advantage in understanding of underlying pathology in assessment of FUO. However, till today, there are limited studies about the role of FDG PET or PET/CT in evaluation of FUO. In this paper, the impact of FDG PET or PET/CT in the diagnostic work-up of FUO is described by data obtained from literature review. PMID:21490728

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

    PubMed Central

    2012-01-01

    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. PMID:22314195

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

    PubMed Central

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

    2016-01-01

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

  5. FDG-PET for hepatobiliary and pancreatic cancer: Advances and current limitations.

    PubMed

    Murakami, Koji

    2011-05-10

    In Japan, the use of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for some malignant tumors came to be covered by the National Health Insurance in 2002. In 2010, the health insurance coverage was expanded to all types of malignant tumors. However, since PET examination requires a large amount of capital investment, facilities at which PET is available are still limited. On the other hand, PET equipment has rapidly been introduced in large hospitals and in the diagnostic imaging centers of major cities during the past few years. Although numerous middle-sized and small hospitals cannot afford to perform PET, physicians can refer their patients to facilities where PET is available. Therefore, it is essential for general physicians to gain accurate knowledge on PET, including the appropriate indications for PET, in order to select patients for referral to PET facilities. PET is not always a useful tool, especially for lesions of the pancreas and hepatobiliary system, which is the main topic of this review. The indications of PET for lesions in these organs vary depending on the purpose of the examination. In this article, we review the indications for PET (or PET/computed tomography [CT]) using FDG of the liver, biliary tract, and pancreas.

  6. [Role of FDG-PET in Staging and Therapy of Children with Hodgkin Lymphoma].

    PubMed

    Kluge, R; Körholz, D

    2011-11-01

    The paediatric Hodgkin lymphoma treatment optimisation concepts aim at reduction of treatment intensity with preservation of the high cure rates. A negative interim FDG-PET result after 2 cycles of chemotherapy is associated with a good prognosis. In the current EuroNet-PHL-C1 study radiotherapy is being omitted, if interim PET becomes negative. In addition to the early interim PET after 2 cycles of chemotherapy, all patients undergo an initial PET investigation which is part of the staging processs and plays an essential role for the interpretation of the interim PET. Skeletal involvement can be detected by a typical FDG-PET uptake pattern with high sensitivity and specifity. Therefore, in the forthcoming EuroNet-PHL-C2 study bone marrow biopsy and bone scintigraphy will no longer be part of the staging algorithm.

  7. Misalignments calibration in small-animal PET scanners based on rotating planar detectors and parallel-beam geometry.

    PubMed

    Abella, M; Vicente, E; Rodríguez-Ruano, A; España, S; Lage, E; Desco, M; Udias, J M; Vaquero, J J

    2012-11-21

    Technological advances have improved the assembly process of PET detectors, resulting in quite small mechanical tolerances. However, in high-spatial-resolution systems, even submillimetric misalignments of the detectors may lead to a notable degradation of image resolution and artifacts. Therefore, the exact characterization of misalignments is critical for optimum reconstruction quality in such systems. This subject has been widely studied for CT and SPECT scanners based on cone beam geometry, but this is not the case for PET tomographs based on rotating planar detectors. The purpose of this work is to analyze misalignment effects in these systems and to propose a robust and easy-to-implement protocol for geometric characterization. The result of the proposed calibration method, which requires no more than a simple calibration phantom, can then be used to generate a correct 3D-sinogram from the acquired list mode data.

  8. A Novel Side-Bridged Hybrid Phosphonate/Acetate Pendant Cyclam: Synthesis, Characterization, and 64Cu Small Animal PET Imaging

    PubMed Central

    Boswell, C. Andrew; Regino, Celeste A. S.; Baidoo, Kwamena E.; Wong, Karen J.; Milenic, Diane E.; Kelley, James A.; Lai, Christopher C.; Brechbiel, Martin W.

    2008-01-01

    Copper-64 (t½ = 12.7 hr; β+: 0.653 MeV, 17.4%; β−: 0.578 MeV, 39%) is produced in a biomedical cyclotron and has applications in both imaging and therapy. Macrocyclic chelators are widely used as bifunctional chelators to bind copper radionuclides to antibodies and peptides owing to their relatively high kinetic stability. A novel side-bridged cyclam featuring both pendant acetate and phosphonate groups was synthesized using a Kabachnik-Fields approach followed by hydrobromic acid deprotection. The Cu(II) complex of the novel ligand was synthesized, radiolabeling with 64Cu was demonstrated, and in vitro (serum) stability was performed. In addition, in vivo distribution and clearance of the 64Cu-labeled complex was visualized by positron emission tomography (PET) imaging. This novel chelate may be useful in 64Cu-mediated diagnostic positron emission tomography (PET) imaging as well as targeted radiotherapeutic applications. PMID:19101152

  9. The Role of 18F-FDG PET/CT Integrated Imaging in Distinguishing Malignant from Benign Pleural Effusion

    PubMed Central

    Sun, Yajuan; Yu, Hongjuan; Ma, Jingquan

    2016-01-01

    Objective The aim of our study was to evaluate the role of 18F-FDG PET/CT integrated imaging in differentiating malignant from benign pleural effusion. Methods A total of 176 patients with pleural effusion who underwent 18F-FDG PET/CT examination to differentiate malignancy from benignancy were retrospectively researched. The images of CT imaging, 18F-FDG PET imaging and 18F-FDG PET/CT integrated imaging were visually analyzed. The suspected malignant effusion was characterized by the presence of nodular or irregular pleural thickening on CT imaging. Whereas on PET imaging, pleural 18F-FDG uptake higher than mediastinal activity was interpreted as malignant effusion. Images of 18F-FDG PET/CT integrated imaging were interpreted by combining the morphologic feature of pleura on CT imaging with the degree and form of pleural 18F-FDG uptake on PET imaging. Results One hundred and eight patients had malignant effusion, including 86 with pleural metastasis and 22 with pleural mesothelioma, whereas 68 patients had benign effusion. The sensitivities of CT imaging, 18F-FDG PET imaging and 18F-FDG PET/CT integrated imaging in detecting malignant effusion were 75.0%, 91.7% and 93.5%, respectively, which were 69.8%, 91.9% and 93.0% in distinguishing metastatic effusion. The sensitivity of 18F-FDG PET/CT integrated imaging in detecting malignant effusion was higher than that of CT imaging (p = 0.000). For metastatic effusion, 18F-FDG PET imaging had higher sensitivity (p = 0.000) and better diagnostic consistency with 18F-FDG PET/CT integrated imaging compared with CT imaging (Kappa = 0.917 and Kappa = 0.295, respectively). The specificities of CT imaging, 18F-FDG PET imaging and 18F-FDG PET/CT integrated imaging were 94.1%, 63.2% and 92.6% in detecting benign effusion. The specificities of CT imaging and 18F-FDG PET/CT integrated imaging were higher than that of 18F-FDG PET imaging (p = 0.000 and p = 0.000, respectively), and CT imaging had better diagnostic consistency with

  10. Clinical significance of incidental FDG uptake in the prostate gland detected by PET/CT

    PubMed Central

    Sahin, Ertan; Elboga, Umut; Kalender, Ebuzer; Basıbuyuk, Mustafa; Demir, Hasan Deniz; Celen, Yusuf Zeki

    2015-01-01

    The value of FDG-positron emission tomography/computed tomography (PET/CT) for detecting prostate cancer is unknown. We aimed to investigate the clinical value of incidental prostate FDG uptake on PET/CT scans. We reviewed 6128 male patients who underwent FDG-PET/CT scans and selected cases that reported hypermetabolic lesion in the prostate. The patients who have prior history of prostate carcinoma or prostate surgery were excluded from the study. We have analyzed the correlation between PET/CT findings and serum prostate-specific antigen (PSA) levels, imaging (USG), urological examinations and biopsy. Incidental 18F-FDG uptake of the prostate gland was observed in 79 patients (1.3%). While sixteen of them were excluded due to inadequate clinical data, the remaining 63 patients were included for further analysis. The patients were divided into two groups; 8 patients (12.7%) in the malignant group and 55 patients (87.3%) in the benign group. The SUVmax values were not significantly different between the two groups. In 6 (75%) patients with prostate cancer, FDG uptake was observed focally in the peripheral zone of the prostate glands. There was no significant correlation between the SUVmax and the PSA levels. Incidental 18F-FDG uptake in the prostate gland is a rare condition, but a substantial portion of it is associated with the cancer. Benign and malignant lesions of the prostate gland in FDG-PET/CT imaging could not be reliably distinguished. The peripheral focally FDG uptake of prostate glands should be further examined with the clinical and labaratory evaluations. PMID:26379847

  11. Characterization and optimization of image quality as a function of reconstruction algorithms and parameter settings in a Siemens Inveon small-animal PET scanner using the NEMA NU 4-2008 standards

    NASA Astrophysics Data System (ADS)

    Visser, Eric P.; Disselhorst, Jonathan A.; van Lier, Monique G. J. T. B.; Laverman, Peter; de Jong, Gabie M.; Oyen, Wim J. G.; Boerman, Otto C.

    2011-02-01

    The image reconstruction algorithms provided with the Siemens Inveon small-animal PET scanner are filtered backprojection (FBP), 3-dimensional reprojection (3DRP), ordered subset expectation maximization in 2 or 3 dimensions (OSEM2D/3D) and maximum a posteriori (MAP) reconstruction. This study aimed at optimizing the reconstruction parameter settings with regard to image quality (IQ) as defined by the NEMA NU 4-2008 standards. The NEMA NU 4-2008 image quality phantom was used to determine image noise, expressed as percentage standard deviation in the uniform phantom region (%STD unif), activity recovery coefficients for the FDG-filled rods (RC rod), and spill-over ratios for the non-radioactive water- and air-filled phantom compartments (SOR wat and SOR air). Although not required by NEMA NU 4, we also determined a contrast-to-noise ratio for each rod (CNR rod), expressing the trade-off between activity recovery and image noise. For FBP and 3DRP the cut-off frequency of the applied filters, and for OSEM2D and OSEM3D, the number of iterations was varied. For MAP, the "smoothing parameter" β and the type of uniformity constraint (variance or resolution) were varied. Results of these analyses were demonstrated in images of an FDG-injected rat showing tumours in the liver, and of a mouse injected with an 18F-labeled peptide, showing a small subcutaneous tumour and the cortex structure of the kidneys. Optimum IQ in terms of CNR rod for the small-diameter rods was obtained using MAP with uniform variance and β=0.4. This setting led to RC rod,1 mm=0.21, RC rod,2 mm=0.57, %STD unif=1.38, SOR wat=0.0011, and SOR air=0.00086. However, the highest activity recovery for the smallest rods with still very small %STD unif was obtained using β=0.075, for which these IQ parameters were 0.31, 0.74, 2.67, 0.0041, and 0.0030, respectively. The different settings of reconstruction parameters were clearly reflected in the rat and mouse images as the trade-off between the recovery of

  12. 18F-DG PET/CT in detection of recurrence and metastasis of colorectal cancer

    PubMed Central

    Chen, Long-Bang; Tong, Jin-Long; Song, Hai-Zhu; Zhu, Hong; Wang, Yu-Cai

    2007-01-01

    AIM: To evaluate the value of 18F-DG PET/CT in detecting recurrence and/or metastasis of colorectal cancer (CRC). METHODS: Combined visual analysis with semiquantitative analysis, the 18F-DG PET/CT whole-body imaging results and the corresponding clinical data of 68 postoperative CRC patients including 48 male and 20 female with average age of 58.1 were analyzed retrospectively. RESULTS: Recurrence and/or metastasis were confirmed in 56 patients in the clinical follow-up after the PET/CT imaging. The sensitivity of PET/CT diagnosis of CRC recurrence and/or metastasis was 94.6%, and the specificity was 83.3%. The positive predictive value (PPV) was 96.4% and the negative predictive value (NPV) was 76.9%. PET/CT imaging detected one or more occult malignant lesions in 8 cases where abdominal/pelvic CT and/or ultrasonography showed negative findings, and also detected more lesions than CT or ultrasonography did in 30.4% (17/56) cases. Recurrence and/or metastasis was detected in 91.7% (22/24) cases with elevated serum CEA levels by 18F-DG PET/CT imaging. CONCLUSION: 18F-DG PET/CT could detect the recurrence and/or metastasis of CRC with high sensitivity and specificity. PMID:17854148

  13. Wavelet denoising in voxel-based parametric estimation of small animal PET images: a systematic evaluation of spatial constraints and noise reduction algorithms.

    PubMed

    Su, Yi; Shoghi, Kooresh I

    2008-11-07

    Voxel-based estimation of PET images, generally referred to as parametric imaging, can provide invaluable information about the heterogeneity of an imaging agent in a given tissue. Due to high level of noise in dynamic images, however, the estimated parametric image is often noisy and unreliable. Several approaches have been developed to address this challenge, including spatial noise reduction techniques, cluster analysis and spatial constrained weighted nonlinear least-square (SCWNLS) methods. In this study, we develop and test several noise reduction techniques combined with SCWNLS using simulated dynamic PET images. Both spatial smoothing filters and wavelet-based noise reduction techniques are investigated. In addition, 12 different parametric imaging methods are compared using simulated data. With the combination of noise reduction techniques and SCWNLS methods, more accurate parameter estimation can be achieved than with either of the two techniques alone. A less than 10% relative root-mean-square error is achieved with the combined approach in the simulation study. The wavelet denoising based approach is less sensitive to noise and provides more accurate parameter estimation at higher noise levels. Further evaluation of the proposed methods is performed using actual small animal PET datasets. We expect that the proposed method would be useful for cardiac, neurological and oncologic applications.

  14. The role of (18)F-FDG PET/CT in the detection of osteosarcoma recurrence.

    PubMed

    Angelini, Andrea; Ceci, Francesco; Castellucci, Paolo; Graziani, Tiziano; Polverari, Giulia; Trovarelli, Giulia; Palmerini, Emanuela; Ferrari, Stefano; Fanti, Stefano; Ruggieri, Pietro

    2017-09-01

    The aim of this study was to investigate the diagnostic accuracy of (18)F-FDG-PET/CT in osteosarcoma patients suspicious for disease recurrence after adequate surgical therapy. Inclusion criteria were: a) adequate surgical treatment for proven osteosarcoma and documented complete remission after therapy; b) (18)F-FDG-PET/CT performed during follow-up for clinical/diagnostic suspicion of relapse; c) new surgical treatment with excision of the suspected lesions; d) histological validation of (18)F-FDG-PET/CT findings. Thirty-seven patients matching all inclusion criteria were retrospectively enrolled (20 men and 17 female). Primary surgical treatment consists of resection (31 cases) or amputation (six cases). (18)F-FDG-PET/CT performance was assessed with a per-patient and per-site evaluation of sensitivity, specificity, accuracy, positive predicting value (PPV), and negative predicting value (NPV). The sites of relapse were classified as local, lung, lymphnodes (LNs), and distant (other skeletal segments and/or distant soft tissue). The disease-free survival (DFS) and the overall survival (OS) after 18F-FDG PET/CT were evaluated. (18)F-FDG-PET/CT was positive in 89.2% (33/37) of patients. Local uptake only was observed in 35.1% patients (13/37); lung uptake only in 18.9% (7/37); distant uptake only in 2.7% (1/37) case; multiple sites of uptake in 32.4% (12/37). Histology resulted positive in 92% (34/37) of patients. A total of 51 pathologic lesions were evaluated (22 local relapse, 11 lung metastasis, 10 metastatic LNs, eight distant metastatic lesions). On a per-patient analysis (18)F-FDG-PET/CT showed a sensitivity, specificity, accuracy, PPV, and NPV of 91%, 75%, 89%, 97%, 50%. On a per-site analysis the performance for local relapse was 96%, 100%, 97%, 100%, 93%, while for lung relapse detection was 80%, 100%, 92%, 100%, 88%. The mean follow-up after (18)F-FDG-PET/CT was 21.5 months. At the last follow-up, 19% (7/37) of patients were death with disease, 38% (14

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

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

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

  16. Additive value of amyloid-PET in routine cases of clinical dementia work-up after FDG-PET.

    PubMed

    Brendel, Matthias; Schnabel, Jonas; Schönecker, Sonja; Wagner, Leonie; Brendel, Eva; Meyer-Wilmes, Johanna; Unterrainer, Marcus; Schildan, Andreas; Patt, Marianne; Prix, Catharina; Ackl, Nibal; Catak, Cihan; Pogarell, Oliver; Levin, Johannes; Danek, Adrian; Buerger, Katharina; Bartenstein, Peter; Barthel, Henryk; Sabri, Osama; Rominger, Axel

    2017-09-20

    In recent years, several [(18)F]-labeled amyloid-PET tracers have been developed and have obtained clinical approval. Despite their widespread scientific use, studies in routine clinical settings are limited. We therefore investigated the impact of [(18)F]-florbetaben (FBB)-PET on the diagnostic management of patients with suspected dementia that was still unclarified after [(18)F]-fluordeoxyglucose (FDG)-PET. All subjects were referred in-house with a suspected dementia syndrome due to neurodegenerative disease. After undergoing an FDG-PET exam, the cases were discussed by the interdisciplinary dementia board, where the most likely diagnosis as well as potential differential diagnoses were documented. Because of persistent diagnostic uncertainty, the patients received an additional FBB-PET exam. Results were interpreted visually and classified as amyloid-positive or amyloid-negative, and we then compared the individual clinical diagnoses before and after additional FBB-PET. A total of 107 patients (mean age 69.4 ± 9.7y) were included in the study. The FBB-PET was rated as amyloid-positive in 65/107. In 83% of the formerly unclear cases, a final diagnosis was reached through FBB-PET, and the most likely prior diagnosis was changed in 28% of cases. The highest impact was observed for distinguishing Alzheimer's dementia (AD) from fronto-temporal dementia (FTLD), where FBB-PET altered the most likely diagnosis in 41% of cases. FBB-PET has a high additive value in establishing a final diagnosis in suspected dementia cases when prior investigations such as FDG-PET are inconclusive. The differentiation between AD and FTLD was particularly facilitated by amyloid-PET, predicting a considerable impact on patient management, especially in the light of upcoming disease-modifying therapies.

  17. Localization of medullary thyroid carcinoma after surgery using (11)C-methionine PET/CT: comparison with (18)F-FDG PET/CT.

    PubMed

    Jang, Hye Won; Choi, Joon Young; Lee, Ji In; Kim, Hee Kyung; Shin, Hyun Won; Shin, Jung Hee; Kim, Sun Wook; Chung, Jae Hoon

    2010-01-01

    Tumor localization is difficult in patients with medullary thyroid carcinoma (MTC) that have persistent hypercalcitoninemia after thyroidectomy. In this study, the (11)C-methionine positron emission tomography/computed tomography (PET/CT) was compared with the (18)F-FDG PET/CT for diagnostic sensitivity in detecting residual or metastatic disease. (11)C-methionine PET/CT and (18)F-FDG PET/CT were performed on 16 consecutive patients with MTC that had persistent hypercalcitoninemia after surgery in this prospective, single-center study. Patient- and lesion-based analyses were performed using a composite reference standard which was the sum of the lesions confirmed by all combined modalities, including neck ultrasonography (US) with or without fine needle aspiration cytology, CT, bone scan, magnetic resonance imaging (MRI), and surgery. By patient-based analysis, the sensitivities of (11)C-methionine PET/CT and (18)F-FDG PET/CT were both 63%. By lesion-based analysis, the sensitivity of (11)C-methionine PET/CT was similar to (18)F-FDG PET/CT (73% vs. 80%). Excluding hepatic lesions, which could not be detected because of physiological uptake of methionine by the liver, the sensitivity of (11)C-methionine PET/CT was better than (18)F-FDG PET/CT especially for detecting cervical lymph node lesions; however, it was not superior to US. All patients with serum calcitonin levels ≥370 pg/mL showed uptake by (11)C-methionine PET/CT and (18)F-FDG PET/CT. This preliminary data showed that despite its similar sensitivity to (18)F-FDG PET/CT for detecting residual or metastatic MTC, (11)C-methionine PET/CT provided minimal additional information compared to combined (18)F-FDG PET/CT and neck US.

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

    SciTech Connect

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

    2015-09-15

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

  19. Correlation of PET and AMS analyses for early kinetics of 2-fluoro-2-deoxyglucose (FDG)

    NASA Astrophysics Data System (ADS)

    Minamimoto, Ryogo; Hamabe, Yoshimi; Miyaoka, Teiji; Theeraladanon, Chumpol; Oka, Takashi; Matsui, Takao; Inoue, Tomio

    2010-04-01

    The draft of the guidelines for microdosing in clinical trials was published in Japan in 2008 following the guidelines of the European Medicines Agency (EMEA) and the Food and Drug Administration (FDA). It recommends utilizing accelerator mass spectrometry (AMS), liquid chromatography/mass spectrometry (LC/MS/MS), and positron emission tomography (PET) for monitoring drug metabolites in preclinical studies. In this study, we clarified the correlation in measuring result between PET and AMS. The AMS measurement was undergone by using AMS system of Institute of Accelerator Analysis Ltd. (IAA, Kawasaki, Japan). First the back ground 14C level of blood in mice was measured by AMS. Second, we clarified the relationship between AMS and PET by using 2-fluoro-2-deoxyglucose (FDG). The correlation coefficient ( r) of the measurements using PET ( 18F-FDG) and AMS ( 14C-FDG) were quite high at 0.97 ( Y = 7.54 E - 05 X + 0.02, p < 0.001). The blood clearance profile of 18F-FDG was nearly identical with that of 14C-FDG. These results indicate that the AMS analysis has excellent correlation with the PET method.

  20. [Study of patients with prolonged fever with (18)F-FDG PET/CT].

    PubMed

    Moragas, M; Cozar, M Puig; Buxeda, M; Soler, M; Riera, E; García, J R

    2015-01-01

    To review the findings on (18)F-FDG PET-CT in patients with fever of unknown origin lasting more than 7 days. This retrospective descriptive observational study included 93 (18)F-FDG PET-CT studies to detect a fever-causing focus done at three nuclear medicine centers from October 2006 through February 2014. A nuclear medicine specialist and a radiologist reviewed the images for foci of pathological uptake; another specialist's opinion resolved discrepancies. The findings on (18)F-FDG PET-CT studies were checked against clinical and/or histological findings. Abnormal (18)F-FDG uptake on PET-CT that could explain the cause of the fever was found in 52 (56%) of the 93 studies, and the cause of the fever was confirmed in 50 of these 52 studies. In the 50 cases in which the cause of the fever was confirmed, infection was the most common cause (54%), followed by noninfectious inflammatory disease (28%) and tumors (18%). (18)F-FDG PET-CT is useful in diagnosing the cause of prolonged febrile illness, so it might be practical to use it earlier in the diagnostic process. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  1. Selection of patients for resection of hepatic metastases: improved detection of extrahepatic disease with FDG pet.

    PubMed

    Zealley, I A; Skehan, S J; Rawlinson, J; Coates, G; Nahmias, C; Somers, S

    2001-10-01

    A rapidly emerging clinical application of positron emission tomography (PET) is the detection of tumor tissue at whole-body studies performed with the glucose analogue 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG). High rates of recurrence after partial hepatic resection in patients with colorectal cancer liver metastases indicate that current presurgical imaging strategies are failing to show extrahepatic tumor deposits. Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in the liver and the lungs, it is particularly useful for identification and characterization of extrahepatic disease. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterization of indeterminate soft-tissue masses. Several sources of benign and physiologic increased activity at FDG PET emphasize the need for careful correlation with findings of other imaging studies and clinical findings. FDG PET can improve the selection of patients for partial hepatic resection and thereby reduce the morbidity and mortality associated with inappropriate surgery.

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

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

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

  3. [SPECT and FDG-PET in diagnostics of neurolues].

    PubMed

    Pichler, Robert; Doppler, Stefan; Szalay, Elisabeth; Hertl, Christine; Knell, Ulrich; Winkler, Johanna

    2008-01-01

    Syphilis is a recurrent treponematosis of acute and chronic evolution. In general it is either sexually or congenitally transmitted. Primary syphilis appears as a single and painless lesion. Secondary syphilis may manifest years later, the secondary bacteremic stage is accompanied by generalized mucocutaneous lesions. Tertiary disease can be disseminated to bones and virtually any organ, involving principally the ascending aorta and the central nervous system. Nuclear medicine provides diagnostic methods in case of skeletal manifestations by bone scan - identifying periostitis and osteomyelitis. Hepatic gummas can be imaged by 99m-Tc-colloid liver scintigraphy. In neurosyphilis brain perfusion SPECT enables imaging of cerebral involvement by small vessel endarteritis resulting from syphilitic vascular disease. 18-FDG PET is also useful to evaluate neurosyphilis, a reduction of brain glucose consumption is observed. The technique adequately enables imaging of therapeutic response and might be superior to morphologic imaging. We present our experiences with these nuclear medicine methods in patients with neurolues. The incidence of neurolues is estimated at 2 per 100.000 inhabitants worldwide, migration processes might bring a re-emergence of this disease to Austria and other developed countries of the EU. Scintigraphic methods should be kept in mind for diagnostic evaluation of neurosyphilis.

  4. Calcified metastases from ovarian carcinoma highlighted by F-18 FDG PET/CT: report of two cases.

    PubMed

    Hu, Si-Long; Zhou, Zheng-Rong; Zhang, Ying-Jian

    2012-08-01

    Two cases of postoperative female patients with ovarian serous papillary carcinoma were referred for F-18 Fluorodeoxyglucose (F-18 FDG) PET/CT to evaluate suspicious recurrence and/or metastasis. One patient presented with multiple extensive calcified lesions with increased FDG uptake in the abdominopelvic cavity and the series of PET/CT scans showed progression of disease after chemotherapy. The other patient presented with three calcified masses with intensive uptake of FDG located in the left pelvis, the right subphrenic region, and the right supradiaphragmatic area, respectively. These suggest that F-18 FDG PET/CT can be useful in identifying malignant calcification and assessing therapeutic response of calcified malignancy.

  5. Sclerosing angiomatoid nodular transformation (SANT) of the spleen: a case report with FDG-PET findings and literature review.

    PubMed

    Imamura, Yumi; Nakajima, Reiko; Hatta, Kazuha; Seshimo, Akiyoshi; Sawada, Tatsuo; Abe, Koichiro; Sakai, Shuji

    2016-08-01

    We report the 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) findings of sclerosing angiomatoid nodular transformation (SANT) of the spleen. The patient was a 37-year-old woman with a splenic mass incidentally found on abdominal ultrasound. FDG-PET/CT showed weak FDG accumulation (maximum standardized uptake value = 3.65). An unenhanced CT scan showed a low density and well-circumscribed splenic tumor that demonstrated weak enhancement from the arterial to delayed phase. Although hemangioma or hamartoma of the spleen was preoperatively diagnosed, histopathological examination revealed SANT. Therefore, when a splenic tumor with weak contrast medium enhancement and low FDG accumulation is observed, SANT should be considered as a differential diagnosis. Although CT and magnetic resonance imaging features of SANT have been reported, there are few reports on FDG-PET/CT findings. We report the radiological features of SANT, including FDG-PET/CT, and review the literature on SANT.

  6. Wavelet-based regularization and edge preservation for submillimetre 3D list-mode reconstruction data from a high resolution small animal PET system

    NASA Astrophysics Data System (ADS)

    de Jesús Ochoa Domínguez, Humberto; Máynez, Leticia Ortega; Villegas, Osslan Osiris Vergara; Castillo, Nelly Gordillo; Sánchez, Vianey Guadalupe Cruz; Casas, Efrén David Gutiérrez

    2011-10-01

    The data obtained from a PET system tend to be noisy because of the limitations of the current instrumentation and the detector efficiency. This problem is particularly severe in images of small animals as the noise contaminates areas of interest within small organs. Therefore, denoising becomes a challenging task. In this paper, a novel wavelet-based regularization and edge preservation method is proposed to reduce such noise. To demonstrate this method, image reconstruction using a small mouse 18F NEMA phantom and a 18F mouse was performed. Investigation on the effects of the image quality was addressed for each reconstruction case. Results show that the proposed method drastically reduces the noise and preserves the image details.

  7. Approach to assessing myocardial perfusion in rats using static [13N]-ammonia images and a small-animal PET.

    PubMed

    Vaquero, Juan José; Gao, Dong-Wei; García-Villaba, Carmen; Bacharach, Stephen; Vanbrocklin, Henry; Fang, Qizhi; Desco, Manuel; Lee, Randall; Dae, Michael

    2012-10-01

    Semi-quantitative, static positron emission tomography (PET) has been used to perform an initial approach to the assessment of [13N]-ammonia perfusion studies aimed to elucidating the effect of injecting human embryonic stem cell-derived (hES) hemangioblasts on infarcted rat hearts. Female NIH nude rats underwent occlusion of the left anterior descending coronary artery for 30 min before reperfusion. Either one million hES-derived hemangioblasts (n = 5) or control media (n = 4) were injected into the site of the infarct 1 day post-myocardial infarction (MI) under high-resolution echocardiography guidance. PET imaging was performed 6 weeks after MI induction, and uptake polar maps were created by sampling the left ventricle at equidistant slices from the base to the apex and measuring the average myocardium value at three contiguous voxels to minimize partial volume effects. Statistical comparison between treatment and control groups was done with a Mann-Whitney U test. Myocardium uptake ratios for treated and untreated subjects show statistically significant difference (98% certainty). The straightforward procedure described here (similar to those commonly used in clinical routine) was sufficient to yield statistically significant perfusion differences between the treated and untreated animals despite the small sample size.

  8. Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma.

    PubMed

    Tiwari, B P; Jangra, S; Nair, N; Tongaonkar, H B; Basu, S

    2010-01-01

    Prostate cancer is one of the most common malignancies of elderly males. Management depends on the accurate estimation of disease both at initial diagnosis and in its subsequent course. In the present study, we evaluated the diagnostic utility of positron emission tomography with 18 F-fluorodeoxyglucose (FDG-PET) in patients having prostate cancer. The findings were compared with the results of bone scan (BS) for the detection of bone metastases. Sixteen patients (age range, 55-83 years) with confirmed diagnosis of prostate cancer were included in the prospective study. Three patients had undergone bilateral orchidectomy, 1 had hormonal therapy, 9 had undergone both, and 3 had no therapy. All the patients underwent wholebody BS and FDG-PET within 1 week. Interpretation of BS and FDG-PET were performed qualitatively. Osseous abnormalities detected by both methods were compared. Involvement of the disease in other sites as seen on FDG-PET was also noted. BS detected 197 osseous lesions, whereas FDG-PET could detect 97 (49%) bone lesions. However, in 3 patients without any prior therapeutic intervention, FDG-PET results were superior or equivalent to that of BS. FDG-PET also detected extensive involvement of the disease in the bone marrow in 4 patients, lymph node metastases at various sites in 8, liver metastases in 2, and lung metastases in 1 patient. FDG-PET could demonstrate less number of osseous metastases in comparison with BSs, but the results have to be interpreted in the background of prior treatment administered and the tumor biology of the lesion. It is evident that FDG-PET could detect the unknown soft tissue involvement of the disease with good sensitivity, which might play an important role in the management of prostate cancer. Overall, in the absence of novel PET tracers, both skeletal scintigraphy and FDG-PET imaging can play a complimentary role in the management of prostate cancer.

  9. Quantitative assessment of crystal material and size on the performance of rotating dual head small animal PET scanners using Monte Carlo modeling.

    PubMed

    Ghazanfari, Nafise; Sarkar, Saeed; Loudos, George; Ay, Mohammad Reza

    2012-01-01

    In this work, among different proposed designs we have studied dual-head coincidence detectors (DHC) with pixelated crystals in order to optimize the design of detector systems of small animal PET scanners. Monte Carlo simulations and different detector components and materials, under different imaging conditions and geant 4 application for tomographic emission (GATE) were used for all simulations. Crystal length and inter material space on system performance were studied modeling several pixel sizes, ranging from 0.5 x 0.5mm² to 3.0 x 3.0mm² by increment of 0.5mm and using epoxy intermaterial with pitch of 0.1, 0.2 and 0.3mm. Three types of scintillator crystals:bismuth germinate orthosilicate, cerium-doped lutetium orthosilicate and gadolinium orthosilicate were simulated with thicknesses of 10mm and 15 mm. For all measurements a point source with the activity of 1MBq was placed at the center of field of view. The above simulation revealed that by increasing pixel size and crystal length in scintillator material of a pixelated array, sensitivity can be raised from 1% to 7%. However, spatial resolution becomes worse when pixel size increases from 0.6mm to 2.6mm. In addition, photons mispositioned events decrease from 76%to 45%. Crystal length decrease, significantly reduces the percentage of mispositioned events from 89% to 59%. Moreover increase in crystal length from 10mm to 15 mm changes sensitivity from 2% to 6% and spatial resolution from 0.6mm to 3.5mm. In conclusion, it was shown that pixel size 2mm with 10mm crystal thickness can provide the best dimensions in order to optimize system performance. These results confirmed the value of GATE Monte Carlo code, as being a useful tool for optimizing nuclear medicine imaging systems performance, for small animal PET studies.

  10. Primary Cutaneous Angiosarcoma Mimicking Metastasis on 18F-FDG PET/CT in Woman With Cervix Cancer.

    PubMed

    Hwang, Jae Pil

    2017-09-01

    Primary cutaneous angiosarcoma is a rare vascular tumor usually affecting the whole body, and its hypermetabolic features on F-FDG PET/CT may be confused with those of infection, metastasis, or primary malignancy. This is a case report of a cutaneous angiosarcoma of the lower anterior abdomen showing increased FDG uptake on F-FDG PET/CT mimicking a cutaneous metastasis in an 84-year-old woman with cervical cancer.

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

    PubMed

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

    2015-12-01

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

  12. Assessment of FDG retention differences between the FDG-avid benign pulmonary lesion and primary lung cancer using dual-time-point FDG-PET imaging.

    PubMed

    Kaneko, Koichiro; Sadashima, Eiji; Sadashima, Shinji; Irie, Koji; Hayashi, Akihiro; Masunari, Satoru; Yoshida, Tsuyoshi; Omagari, Junichi

    2013-05-01

    The aim of this study was to clarify FDG retention differences between FDG-avid benign pulmonary lesions (BPLs) and primary lung cancers (PLCs), and between tuberculous and non-tuberculous BPLs using dual-time-point FDG-PET imaging. Thirty-four BPLs and 47 PLCs with a maximal standardized uptake value (SUVmax) >2.5 and a maximal axial diameter >10 mm were enrolled. We compared the retention index (RI) among different types of lesions, and evaluated the relationship between RI and SUVmax at 1 h (SUV1). Glucose transporter-1 (Glut-1) and hexokinase (HK)-2 expression was assessed in eight non-tuberculous BPLs. BPLs and PLCs showed similar high RIs (mean ± SD 33.6 ± 22.6 and 32.5 ± 23.7, respectively; p = 0.95). In BPLs, both tuberculous and non-tuberculous lesions showed high RIs (39.1 ± 25.8 and 30.3 ± 20.3, respectively; p = 0.43). However, BPLs and PLCs exhibited a different relationship between RI and SUV1. BPLs tended to show lower RIs with higher SUV1s, and a mild negative correlation, whereas PLCs showed persistent high RIs and no significant correlation. Glut-1 and HK-2 expression was found in 75 and 12.5 % of non-tuberculous BPLs, respectively. FDG-avid BPLs could show high RIs regardless of their being tuberculous and non-tuberculous lesions, and no significant difference with PLC RIs was found. FDG-avid BPLs and PLCs showed different relationships between RI and SUV1, and it seemed to be related with different mechanisms of high FDG retention. However, the mechanisms of high FDG retention in FDG-avid BPLs remain unclear, and this matter requires further investigation.

  13. Analysis of various malignant neoplasms detected by FDG-PET cancer screening program: based on a Japanese Nationwide Survey.

    PubMed

    Minamimoto, Ryogo; Senda, Michio; Terauchi, Takashi; Jinnouchi, Seishi; Inoue, Tomio; Iinuma, Takeshi; Inoue, Takeshi; Ito, Kengo; Iwata, Hiroshi; Uno, Kimiichi; Oku, Shinya; Oguchi, Kazuhiro; Tsukamoto, Eriko; Nakashima, Rumi; Nishizawa, Sadahiko; Fukuda, Hiroshi; Murano, Takeshi; Yoshida, Tsuyoshi

    2011-01-01

    The most distinctive feature of FDG-PET cancer screening program is the ability to find various kinds of malignant neoplasms in a single test. The aim of this survey is to clarify the range and frequency of various malignant neoplasms detected by FDG-PET cancer screening performed in Japan. "FDG-PET cancer screening" was defined as FDG-PET or positron emission tomography and computed tomography (PET/CT) scan with or without other tests performed for cancer screening of healthy subjects. This survey was based on a questionnaire regarding FDG-PET cancer screening. We analyzed the situation of 9 less frequently found malignant neoplasms including malignant lymphoma, malignancy of head and neck, esophagus, hepatobiliary and gallbladder, pancreas, kidney, cervical and uterine, ovary, and bladder. The detailed information of subjects with the suspected 9 kinds of malignant neoplasms mentioned above in the FDG-PET cancer screening program was studied in a total of 1,219 cases from 212 facilities. A statistical significance between PET/CT and PET was found in relative sensitivity and PPV for renal cell cancer. Malignant lymphoma was frequently of indolent type, suspected head and neck cancers had many false-positive results, and pancreatic cancer detected in this program was often in the advanced stage even in asymptomatic subjects. The recommendation of combined screening modality to PET or PET/CT was as follows: gastric endoscopy for assessing early esophageal cancer; abdominal ultrasound for screening hepatobiliary and gallbladder cancer; pelvic magnetic resonance imaging for assessing gynecological and pelvic cancers; and the CA125 blood test for screening ovarian cancer. Delayed image was helpful depending on the type of suspected malignant neoplasm. We analyzed various types of malignant neoplasms detected by the FDG-PET cancer screening program and presented recommended combination of examinations to cover FDG-PET and PET/CT.

  14. Clinicopathological Features of Cases with Primary Breast Cancer not Identified by 18F-FDG-PET.

    PubMed

    Fujii, Takaaki; Yajima, Reina; Tsuboi, Miki; Higuchi, Toru; Obayashi, Sayaka; Tokiniwa, Hideaki; Nagaoka, Rin; Takata, Daisuke; Horiguchi, Jun; Kuwano, Hiroyuki

    2016-06-01

    Several studies have reported that high F18-fluorodeoxyglucose (FDG) uptake is predictive of poor prognosis and aggressive features in patients with breast cancer. While these studies evaluated the prognostic value for cases with high FDG uptake, they did not elucidate the meaning of FDG negativity in primary breast cancer. In this study, we evaluated the clinicopathological features of breast cancer cases without FDG uptake. We retrospectively investigated the cases of 219 consecutive patients with primary breast cancer who underwent FDG-positron emission tomography (PET) preoperatively. Among the 219 patients, 25 (11.4%) did not have FDG uptake in the tumor. The 219 cases with breast cancer were divided into two groups based on the presence of FDG uptake in the primary tumor. The present univariate analysis revealed that histology, small invasive tumor size, high estrogen receptor (ER) or progesterone receptor (PgR) expression, low nuclear grade and absence of lymph node metastasis were significantly associated with negative FDG uptake in the primary tumor. On the other hand, the size of ductal spread was not significantly different between the two groups. Multivariate analysis revealed that small-size tumor invasion and lower nuclear grade were statistically significant. Among the 25 cases without FDG uptake, there was no recurrent disease in spite of there being no case that underwent chemotherapy, while 4 cases among the 194 cases with FDG uptake had disease recurrence. Our findings imply that preoperative FDG negativity in primary breast cancer is effective in predicting better prognosis, but is less effective in predicting ductal spread. Cases without FDG uptake in the primary tumor may have a lower risk of recurrent disease and may be able to safely avoid adjuvant chemotherapy. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  15. In Vivo ¹⁸F-FDG-PET Imaging in Mouse Atherosclerosis.

    PubMed

    Mateo, Jesús; Bilbao, Izaskun; Vaquero, Juan José; Ruiz-Cabello, Jesús; España, Samuel

    2015-01-01

    Positron emission tomography (PET) is an important technique in cardiovascular research. Vascular inflammation detected by fluorodeoxyglucose (FDG)-PET has been shown to predict cardiovascular (CV) events independent of traditional risk factors and is also highly associated with overall burden of atherosclerosis. The use of PET imaging in mouse models of atherosclerosis is challenged by the reduced size of the scanned organs. However, the last generation of dedicated PET scanners has an improved spatial resolution (<1 mm) and increased sensitivity allowing those studies to be performed. Here, we describe a procedure to perform FDG-PET experiments in atherosclerosis mouse models, the required equipment for animal handling and imaging, and the tools and procedures for image analysis and validation of the results.

  16. Rifaximin suppresses background intestinal 18F-FDG uptake on PET/CT scans.

    PubMed

    Franquet, Elisa; Palmer, Mathew R; Gifford, Anne E; Selen, Daryl J; Chen, Yih-Chieh S; Sedora-Roman, Neda; Joyce, Robin M; Kolodny, Gerald M; Moss, Alan C

    2014-10-01

    Identification of cancer or inflammatory bowel disease in the intestinal tract by PET/computed tomography (CT) imaging can be hampered by physiological uptake of F-fluorodeoxyglucose (F-FDG) in the normal colon. Previous work has localized this F-FDG uptake to the intestinal lumen, predominantly occupied by bacteria. We sought to determine whether pretreatment with an antibiotic could reduce F-FDG uptake in the healthy colon. Thirty patients undergoing restaging PET/CT for nongastrointestinal lymphoma were randomly selected to receive rifaximin 550 mg twice daily for 2 days before their scan (post-rifaximin). Their PET/CT images were compared with those from their prior study (pre-rifaximin). Cecal maximum standard uptake value (SUVmax) and overall colonic F-FDG uptake were compared between scans. All PET/CT images were blindly scored by a radiologist. The same comparison of sequential scans was also undertaken in 30 patients who did not receive antibiotics. Thirty post-rifaximin scans were compared with 30 pre-rifaximin scans in the same patients. SUVmax in the cecum was significantly lower in the patient's post-rifaximin scans than in their pre-rifaximin scans (P=0.002). The percentage of scans with greater than grade 1 colonic F-FDG uptake was significantly lower in the post-rifaximin scans than in the pre-rifaximin scans (P<0.05). In contrast, there was no significant difference in the paired sequential scans from control patients, nor a reduction in the percentage of scans with greater than grade 1 colonic F-FDG uptake. This pilot study shows that treatment with rifaximin for 2 days before PET/CT scanning can significantly reduce physiological F-FDG uptake in the normal colonic lumen.

  17. The value of 18F-FDG PET/CT in diagnosing infectious endocarditis.

    PubMed

    Kouijzer, Ilse J E; Vos, Fidel J; Janssen, Marcel J R; van Dijk, Arie P J; Oyen, Wim J G; Bleeker-Rovers, Chantal P

    2013-07-01

    Early detection of infectious endocarditis is challenging. For diagnosing infectious endocarditis, the revised Duke criteria are the gold standard. Evidence of endocardial involvement on echocardiography is a major criterion, but sensitivity and specificity of echocardiography are not optimal. Here we investigated the utility of (18)F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT) to diagnose infectious endocarditis in patients with gram-positive bacteraemia. Seventy-two patients with gram-positive bacteraemia were prospectively included. Patients with a positive blood culture growing Staphylococcus aureus, Streptococcus species or Enterococcus species were eligible when a risk factor for developing metastatic infectious foci was present. Infectious endocarditis was defined according to the revised Duke criteria. All patients underwent (18)F-FDG PET/CT and echocardiography. (18)F-FDG uptake in or around the heart valves was evaluated independently by two nuclear medicine physicians. Sensitivity for diagnosing infectious endocarditis with (18)F-FDG PET/CT was 39% and specificity was 93%. The positive predictive value was 64% and negative predictive value was 82%. The mortality rate in patients without infectious endocarditis and without increased (18)F-FDG uptake in or around the heart valves was 18%, and in patients without infectious endocarditis but with high (18)F-FDG uptake in or around the heart valves the mortality rate was 50% (p = 0.181). (18)F-FDG PET/CT is currently not sufficiently adequate for the diagnosis of infectious endocarditis because of its low sensitivity. Improvements such as patient preparation with low carbohydrate-fat allowed diet and technical advances in the newest PET/CT scanners may increase sensitivity in future studies.

  18. Small-Animal PET Imaging of Pancreatic Cancer Xenografts Using a 64Cu-Labeled Monoclonal Antibody, MAb159.

    PubMed

    Wang, Hui; Li, Dan; Liu, Shuanglong; Liu, Ren; Yuan, Hong; Krasnoperov, Valery; Shan, Hong; Conti, Peter S; Gill, Parkash S; Li, Zibo

    2015-06-01

    Overexpression of the GRP78 receptor on cell surfaces has been linked with tumor growth, metastasis, and resistance to therapy. We developed a (64)Cu-labeled probe for PET imaging of tumor GRP78 expression based on a novel anti-GRP78 monoclonal antibody, MAb159. MAb159 was conjugated with the (64)Cu-chelator DOTA through lysines on the antibody. DOTA-human IgG was also prepared as a control that did not bind to GRP78. The resulting PET probes were evaluated in BXPC3 pancreatic cancer xenografts in athymic nude mice. The radiotracer was synthesized with a specific activity of 0.8 MBq/μg of antibody. In BXPC3 xenografts, (64)Cu-DOTA-MAb159 demonstrated prominent tumor accumulation (4.3 ± 1.2, 15.4 ± 2.6, and 18.3 ± 1.0 percentage injected dose per gram at 1, 17, and 48 after injection, respectively). In contrast, (64)Cu-DOTA-human IgG had low BXPC3 tumor accumulation (4.8 ± 0.5, 7.5 ± 0.7, and 4.6 ± 0.8 percentage injected dose per gram at 1, 17, and 48 h after injection, respectively). We demonstrated that GRP78 can serve as a valid target for pancreatic cancer imaging. The success of this approach will be valuable for evaluating disease course and therapeutic efficacy at the earliest stages of anti-GRP78 treatment. Moreover, these newly developed probes may have important applications in other types of cancer overexpressing GRP78. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  19. 18F-FDG PET/CT for Early Postradiotherapy Assessment in Solitary Bone Plasmacytomas.

    PubMed

    Alongi, Pierpaolo; Zanoni, Lucia; Incerti, Elena; Fallanca, Federico; Mapelli, Paola; Papathanasiou, Nikolaos; Gianolli, Luigi; Picchio, Maria; Bomanji, Jamshed

    2015-08-01

    The purpose of this study was to evaluate the performance and possible prognostic value of early (18)F-FDG PET/CT (FDG PET/CT) assessment after radiotherapy (RT) in patients with solitary bone plasmacytoma (SBP). Twenty-one patients affected by SBP who underwent FDG PET/CT scan for early restaging (≤6 months) postradiotherapy assessment were selected from the PET databases of University College London Hospital of London and San Raffaele Hospital of Milan. Patients with no abnormal uptake were classified as having no pathologic uptake (NPU). A SUV(max) cutoff value of 4 was chosen to discriminate minimal residual uptake (MRU; SUV(max) ≤ 4) from pathologic uptake (PU, SUV(max) >4). Progression-free survival (PFS) rate was estimated using Kaplan-Meier curves and Cox regression analysis. In 10 of 21 patients restaged by FDG PET/CT, further previous baseline scan was available also at staging, and results showed positive findings at the level of all biopsy-proven disease areas.Considering MRU as PU, FDG PET/CT showed a sensitivity and specificity of 86% and 29%, respectively. Using SUV(max) >4 as the cutoff, sensitivity and specificity were 86% and 93%, respectively. Kaplan-Meier curves revealed a significant difference in PFS probability between patients classified as positive on FDG PET/CT using a cutoff of SUV(max) >4 (PU) and those classified as negative (NPU + MRU) (log-rank, Mantel-Cox, P = 0.009; χ(2) = 6.85). Cox regression analysis of PFS using SUV(max) >4 as cutoff revealed an interesting relation in prediction of progression (HR, 9.458). (18)F-FDG PET/CT for early restaging after RT in patients with SBP should be considered carefully in view of the lack of specificity of a low SUV(max) value. The good correlation between a high SUV(max) value and follow-up suggests a possible prognostic role for FDG PET/CT in disease progression at early restaging after RT.

  20. EANM procedure guidelines for PET brain imaging using [18F]FDG, version 2.

    PubMed

    Varrone, Andrea; Asenbaum, Susanne; Vander Borght, Thierry; Booij, Jan; Nobili, Flavio; Någren, Kjell; Darcourt, Jacques; Kapucu, Ozlem L; Tatsch, Klaus; Bartenstein, Peter; Van Laere, Koen

    2009-12-01

    These guidelines summarize the current views of the European Association of Nuclear Medicine Neuroimaging Committee (ENC). The purpose of the guidelines is to assist nuclear medicine practitioners in making recommendations, performing, interpreting, and reporting the results of fluorine-18 fluoro-2-deoxyglucose ([(18)F]FDG) PET imaging of the brain. The aim is to help achieve a high standard of FDG imaging, which will increase the diagnostic impact of this technique in neurological and psychiatric practice. The present document replaces a former version of the guidelines that were published in 2002 [1] and includes an update in the light of advances in PET technology, the introduction of hybrid PET/CT systems and the broadening clinical indications for FDG brain imaging. These guidelines are intended to present information specifically adapted for European practice. The information provided should be taken in the context of local conditions and regulations.

  1. Growing applications of FDG PET-CT imaging in non-oncologic conditions

    PubMed Central

    Zhuang, Hongming; Codreanu, Ion

    2015-01-01

    Abstract As the number of clinical applications of 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET-CT) grows, familiarity with the conditions that can be diagnosed by this modality and when relevant pieces of additional information can be obtained becomes increasingly important for both requesting physicians and nuclear medicine physicians or radiologists who interpret the findings. Apart from its heavy use in clinical oncology, FDG PET-CT is widely used in a variety of non-oncologic conditions interconnecting to such disciplines as general internal medicine, infectious diseases, cardiology, neurology, surgery, traumatology, orthopedics, pediatrics, endocrinology, rheumatology, psychiatry, neuropsychology, and cognitive neuroscience. The aim of this review was to summarize the current evidence of FDG PET-CT applications in evaluating non-oncologic pathologies and the relevant information it can add to achieve a final diagnosis. PMID:26060443

  2. [Bone metastases from unknown primary. FDG-PET detection of two synchronous tumors].

    PubMed

    Cuenca Cuenca, J I; Borrego Dorado, I; Rodríguez Rodríguez, J R; Navarro González, E; Vázquez Albertino, R

    2007-01-01

    A 60-year-old woman presented with noncardiac chest pain over months and negative laboratory findings. Conventional imaging methods and bone scintigraphy detected bone lesions suggesting metastatic disease from an unknown primary tumor. An 18FDG-PET scan performed to orient the search for the primary tumor found focal lesions suggesting lymphoma and identified a focal thyroid lesion and a cervical lymph node accessible for biopsy. The biopsy of this lymph node incidentally detected a papillary differentiated thyroid cancer (DTC), since the existence of a non-Hodgkin's lymphoma was confirmed after a new biopsy. After confirming the presence of a lymphoma, 18FDG-PET enabled the initial staging of the tumor, the evaluation of the response to treatment, and follow-up for detection of recurrence. On the other hand, 18FDG-PET incidentally detected a DTC.

  3. Diagnosing neuroleukemiosis: Is there a role for (18)F-FDG-PET/CT?

    PubMed

    Sabaté-Llobera, A; Cortés-Romera, M; Gamundí-Grimalt, E; Sánchez-Fernández, J J; Rodríguez-Bel, L; Gámez-Cenzano, C

    2017-05-04

    An imaging case is presented on a patient referred to our department for an (18)F-FDG-PET/CT, as a paraneoplastic syndrome was suspected due to his clinical situation. He had a history of acute myeloid leukemia (AML) treated two years earlier, with sustained complete remission to date. (18)F-FDG-PET/CT findings revealed hypermetabolism in almost all nerve roots, suggesting meningeal spread, consistent with the subsequent MRI findings. Cerebrospinal fluid (CSF) findings confirmed a leptomeningeal reactivation of AML. Although not many studies have evaluated the role of (18)F-FDG-PET/CT in leukemia, it is a noninvasive tool for detecting extramedullary sites of disease and a good imaging alternative for those patients on whom an MRI cannot be performed. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  4. ¹⁸F-FDG-PET/CT Imaging in Patients with Febrile Neutropenia and Haematological Malignancies.

    PubMed

    Camus, Vincent; Edet-Sanson, Agathe; Bubenheim, Michael; Hitzel, Anne; Becker, Stéphanie; David, Marion; Stamatoullas, Aspasia; Lenain, Pascal; Jardin, Fabrice; Contentin, Nathalie; Fontoura, Marie Laure; Cardinael, Nathalie; Vaudaux, Sandrine; Dubois, Sydney; Tilly, Hervé; Vera, Pierre; Leprêtre, Stéphane

    2015-05-01

    The aim of the present study was to assess the prevalence of hyper-metabolic infection sites revealed by fluorine-18 ((18)F) fluorodeoxyglucose (FDG) positron-emission tomography (PET) combined with computed tomography (CT) in patients with febrile neutropenia (FN). Forty-eight consecutive patients with haematological malignancies and persistent FN (temperature ≥ 38°C and neutrophil count <500 cells/μl for more than two days) as a consequence of intensive chemotherapy were prospectively included. Pathological FDG uptakes identified 31 foci of infections located in the lungs (n=15, 48.4 %), colon (n=4, 12.9%), pancreas (n=2, 6.5%), skin (n=3, 9.7%), ear-nose-throat area (n=5, 16.1%), central venous catheter tract (n=1, 3.2%) and gallbladder (n=1, 3.2%). These pathological FDG uptakes were observed in half of the 48 patients (n=24). Among the 38 patients with a clinical diagnosis of infection, 23 showed a pathological FDG uptake, resulting in a FDG-PET/CT sensitivity of 61% (95% CI, 43-76%). Our study confirmed the ability of FDG-PET/CT to diagnose infections in patients with persistent FN. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  5. 18F-FDG PET/CT in multicentric Castleman disease: a case report

    PubMed Central

    Zhang, Jiexin; Yang, Lu

    2016-01-01

    Castleman disease (CD) is a chronic lymphoproliferative disorder characterized by unexplained enlarged lymph nodes. According to lymph nodes distribution it contains two types of single-centric and multicentric (more than one site) disease. Multicentric Castleman disease (MCD) is rare, and shows unspecific manifestation with high misdiagnosis rate. Here we reported a case of MCD in a 43-year-old male. 18F-FDG PET/CT imaging demonstrated higher FDG uptake in multiple lymph nodes and slightly FDG uptake in spleen and bone marrow. Right inguinal Lymph node biopsy was taken and the results confirmed CD. PMID:26904580

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

    PubMed

    Lin, Eugene; Sicuro, Paul

    2008-04-01

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

  7. Asymmetric pulmonary hypermetabolism on 18F-FDG PET/CT caused by pulmonary embolism.

    PubMed

    Caekebeke, Evert; Deroose, Christophe M; Verhamme, Peter; Coolen, Johan; Gheysens, Olivier

    2015-04-01

    We present a case of diffuse and moderately increased 18F-FDG uptake in the entire left lung on 18F-FDG PET without any morphological parenchymal abnormalities in a patient with recent history of esophageal adenocarcinoma treated by minimal invasive surgery and adjuvant chemotherapy. Contrast-enhanced CT revealed a large embolism in the left pulmonary artery with near total occlusion. In the absence of parenchymal lesions, the increased 18F-FDG uptake is most likely an inflammatory response to a recent ischemic insult. This case illustrates that asymmetric lung hypermetabolism in the absence of parenchymal disease can be caused by a central pulmonary embolism.

  8. 18F-FDG PET and intravascular ultrasonography (IVUS) images compared with histology of atherosclerotic plaques: 18F-FDG accumulates in foamy macrophages.

    PubMed

    Ishino, Seigo; Ogawa, Mikako; Mori, Ikuo; Nishimura, Satoshi; Ikeda, Shota; Sugita, Taku; Oikawa, Tatsuo; Horiguchi, Takashi; Magata, Yasuhiro

    2014-04-01

    Intravascular ultrasonography (IVUS) and (18)F-FDG PET have been used to evaluate the efficacy of antiatherosclerosis drugs. These two modalities image different characteristics of atherosclerotic plaques, and a comparison of IVUS and PET images with histology has not been performed. The aim of this study was to align IVUS and PET images using anatomic landmarks in Watanabe heritable hyperlipidaemic (WHHL) rabbits, enabling comparison of their depiction of aortic atherosclerosis. Cellular (18)F-FDG localization was evaluated by (3)H-FDG microautoradiography (micro-ARG). A total of 19 WHHL rabbits (7 months of age) were divided into three groups: baseline (n = 6), 3 months (n = 4), and 6 months (n = 9). PET, IVUS and histological images of the same aortic segments were analysed. Infiltration by foamy macrophages was scored from 0 to IV using haematoxylin and eosin (H&E) and antimacrophage immunohistochemical staining, and compared with (3)H-FDG micro-ARG findings in two additional WHHL rabbits. IVUS images did not identify foamy macrophage deposition but revealed the area of intimal lesions (r = 0.87). (18)F-FDG PET revealed foamy macrophage distribution in the plaques. The intensity of (18)F-FDG uptake was correlated positively with the degree of foamy macrophage infiltration. Micro-ARG showed identical (3)H-FDG accumulation in the foamy macrophages surrounding the lipid core of the plaques. F-FDG PET localized and quantified the degree of infiltration of foamy macrophages in atherosclerotic lesions. IVUS defined the size of lesions. (18)F-FDG PET is a promising imaging technique for evaluating atherosclerosis and for monitoring changes in the composition of atherosclerotic plaques affecting their stability.

  9. Diagnostic value of FDG-PET/(CT) in children with fever of unknown origin and unexplained fever during immune suppression.

    PubMed

    Blokhuis, Gijsbert J; Bleeker-Rovers, Chantal P; Diender, Marije G; Oyen, Wim J G; Draaisma, Jos M Th; de Geus-Oei, Lioe-Fee

    2014-10-01

    Fever of unknown origin (FUO) and unexplained fever during immune suppression in children are challenging medical problems. The aim of this study is to investigate the diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and FDG-PET combined with computed tomography (FDG-PET/CT) in children with FUO and in children with unexplained fever during immune suppression. All FDG-PET/(CT) scans performed in the Radboud university medical center for the evaluation of FUO or unexplained fever during immune suppression in the last 10 years were reviewed. Results were compared with the final clinical diagnosis. FDG-PET/(CT) scans were performed in 31 children with FUO. A final diagnosis was established in 16 cases (52 %). Of the total number of scans, 32 % were clinically helpful. The sensitivity and specificity of FDG-PET/CT in these patients was 80 % and 78 %, respectively. FDG-PET/(CT) scans were performed in 12 children with unexplained fever during immune suppression. A final diagnosis was established in nine patients (75 %). Of the total number of these scans, 58 % were clinically helpful. The sensitivity and specificity of FDG-PET/CT in children with unexplained fever during immune suppression was 78 % and 67 %, respectively. FDG-PET/CT appears a valuable imaging technique in the evaluation of children with FUO and in the diagnostic process of children with unexplained fever during immune suppression. Prospective studies of FDG-PET/CT as part of a structured diagnostic protocol are warranted to assess the additional diagnostic value.

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

    SciTech Connect

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

    1994-05-01

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

  11. 18F-FDG PET in the Evaluation of Acuity of Deep Vein Thrombosis

    PubMed Central

    Rondina, Matthew T.; Lam, Uyen T.; Pendleton, Robert C.; Kraiss, Larry W.; Wanner, Nathan; Zimmerman, Guy A.; Hoffman, John M.; Hanrahan, Christopher; Boucher, Kenneth; Christian, Paul E.; Butterfield, Regan I.; Morton, Kathryn A.

    2013-01-01

    Purpose 18F-FDG PET has been used for vascular disease, but its role in deep vein thrombosis (DVT) remains prospectively unexplored. Patients and Methods Whole-body 18F-FDG PET/CT scans were performed in patients 1 to 10 weeks after onset of symptomatic DVT (n = 12) and in control subjects without DVT (n = 24). The metabolic activity (SUVmax) of thrombosed and contralateral nonthrombosed vein segments was determined. The sensitivity and specificity of 18F-FDG PET/CT for the diagnosis of DVT were determined by receiver operating characteristic curve analyses. In 2 patients with DVT, changes in the metabolic activity of thrombosed vein segments in serial 18F-FDG PET scans. Results The metabolic activity in thrombosed veins [SUVmax, 2.41 (0.75)] was visually appreciable and significantly higher than in nonthrombosed veins in either the contralateral extremity of patients with DVT [SUVmax, 1.09 (0.25), P = 0.007] or control subjects [1.21 (0.22), P < 001]. The area under the receiver operating characteristic curve for SUVmax was 0.9773 (P < 001), indicating excellent accuracy. An SUVmax threshold of greater than 1.645 was 87.5% sensitive and 100% specific for DVT. Metabolic activity in thrombosed veins correlated significantly with time from DVT symptom onset (decrease in SUVmax of 0.02/d, P < 0.05). Best-fit-line analyses suggested that approximately 84 to 91 days after acute DVT, the maximum metabolic activity of thrombosed veins would return to normal levels. Conclusions 18F-FDG PET/CT is accurate for detecting acute symptomatic, proximal DVT. Metabolic activity in thrombosed veins decreases with time, suggesting that 18F-FDG PET may be helpful in assessing the age of the clot. PMID:23154470

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

    PubMed

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

    2007-02-01

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

  13. Sequential FDG-PET brachytherapy treatment planning in carcinoma of the cervix

    SciTech Connect

    Lin, Lilie L.; Mutic, Sasa M.S.; Malyapa, Robert S.; Low, Daniel A.; Miller, Tom R.; Vicic, Milos; LaForest, Richard; Zoberi, Imran; Grigsby, Perry W. . E-mail: pgrigsby@wustl.edu

    2005-12-01

    Purpose: To evaluate the utility of sequential {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging for brachytherapy treatment planning in patients with carcinoma of the cervix. Methods and Materials: Twenty-four patients with carcinoma of the cervix were included in this prospective study. The clinical stage of their disease was Ib (7), IIa (1), IIb (7), and IIIb (9). Patients were treated with irradiation and brachytherapy, with the majority receiving concurrent weekly cisplatin chemotherapy. Patients underwent diagnostic FDG-PET imaging before treatment, sequential FDG-PET brachytherapy imaging during treatment, and diagnostic FDG-PET 3 months after treatment completion. Delineation of the gross tumor volume, bladder, and rectum was performed for all scans using a commercially available treatment-planning system. Actual treatment delivery was based on two-dimensional orthogonal planning. Results: The mean gross tumor volume and percent coverage by the target isodose surface for the initial, mid, and last implant were 37 cm{sup 3}, 17 cm{sup 3}, and 10 cm{sup 3} and 68%, 76%, and 79%, respectively. Nine of 11 patients were found to have continued decrease in tumor volume as measured by FDG-PET, with 3 patients having complete regression of their tumor before treatment was completed. The maximal bladder and rectal doses obtained from three-dimensional dose-volume histograms were significantly higher than the International Commission on Radiation Units and Measurements Report 38 bladder and rectal points obtained by two-dimensional treatment-planning. Conclusions: Sequential FDG-PET brachytherapy imaging identifies the tumor response in individual patients, potentially making patient-specific brachytherapy treatment planning possible.

  14. Intestinal Glycolysis Visualized by FDG PET/CT Correlates With Glucose Decrement After Gastrectomy.

    PubMed

    Ku, Cheol Ryong; Lee, Narae; Hong, Jae Won; Kwon, In Gyu; Hyung, Woo Jin; Noh, Sung Hoon; Lee, Eun Jig; Yun, Mijin; Cho, Arthur

    2017-02-01

    Gastrectomy method is known to influence glucose homeostasis. (18)F-fluoro-2-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) images acquired after gastrectomy often reveals newly developed physiological small bowel uptake. We correlated newly developed small bowel FDG uptake and glucose homeostasis in postgastrectomy gastric cancer patients. We retrospectively analyzed 239 patients without diabetes who underwent staging and follow-up FDG PET/CT scanning before and after gastrectomy for gastric cancer. Postoperative small bowel glycolysis was quantified by recording intestinal total lesion glycolysis (TLG). TLG was assessed with regard to surgical method (Billroth I, Billroth II [BII], Roux-en-Y [RY]), fasting glucose decrement (≥10 mg/dL), and other clinical factors. Patients' weight, fasting glucose, cholesterol, TLG, and body fat levels significantly decreased after surgery. The glucose decrement was significantly associated with fasting glucose, surgical methods, total cholesterol, TLG, and total body fat on univariate analysis. Multivariate analysis showed that BII surgery (odds ratio 6.51) and TLG (odds ratio 3.17) were significantly correlated with glucose decrement. High small bowel glycolysis (TLG >42.0 g) correlated with glucose decrement in RY patients. Newly developed small bowel glycolysis on postgastrectomy FDG PET/CT scanning is correlated with a glucose decrement. These findings suggest a potential role of FDG PET/CT scanning in the evaluation of small bowel glycolysis and glucose control. © 2017 by the American Diabetes Association.

  15. Regional, kinetic [18F]FDG PET imaging of a unilateral Parkinsonian animal model

    PubMed Central

    Silva, Matthew D; Glaus, Charles; Hesterman, Jacob Y; Hoppin, Jack; Puppa, Geraldine Hill della; Kazules, Timothy; Orcutt, Kelly M; Germino, Mary; Immke, David; Miller, Silke

    2013-01-01

    Positron emission tomography (PET) imaging with the glucose analog 2-deoxy-2-[18F]fluoro-D-glucose ([18F] FDG) has demonstrated clinical utility for the monitoring of brain glucose metabolism alteration in progressive neurodegenerative diseases. We examined dynamic [18F]FDG PET imaging and kinetic modeling of atlas-based regions to evaluate regional changes in the cerebral metabolic rate of glucose in the widely-used 6-hydroxydopamine (6-OHDA) rat model of Parkinson’s disease. Following a bolus injection of 18.5 ± 1 MBq [18F]FDG and a 60-minute PET scan, image-derived input functions from the vena cava and left ventricle were used with three models, including Patlak graphical analysis, to estimate the influx constant and the metabolic rate in ten brain regions. We observed statistically significant changes in [18F]FDG uptake ipsilateral to the 6-OHDA injection in the basal ganglia, olfactory bulb, and amygdala regions; and these changes are of biological relevance to the disease. These experiments provide further validation for the use of [18F]FDG PET imaging in this model for drug discovery and development. PMID:23526185

  16. [Clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer].

    PubMed

    Cuenca Cuenca, J I; Borrego Dorado, I; Vázquez Albertino, R; Gómez Camarero, P; Sanz Viedma, S; Fernández López, R

    2008-01-01

    To evaluate the efficacy and clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer. Between October 2001 and October 2006, we retrospectively studied 49 FDG-PET performed in 40 women (age: 52.4 +/- 12.2 years) with ovarian cancer, who had suspicion of recurrent disease by positive morphologic imaging tests (MIT) or increased tumour markers and negative MIT. All patients underwent whole body FDG-PET after the injection of 370-434 MBq of (18)FDG. The results were confirmed by histology in 31 cases, and by clinical-radiological follow-up in 18. Prevalence of disease was 79.6 %. We obtained a global sensitivity and positive predictive value of 87.2 % and 87.2 %, and an accuracy of 79.6 %. Results led to a change in the patient's management in 25 cases (51 %). Subgroup results were: Sensitivity of 81.8 % in patients with increased tumour markers and negative MIT, and 89.3 % in patients with operable malignant lesions. FDG-PET has high sensitivity and clinical impact in patients with suspicion of recurrent ovarian cancer. Better results were obtained in patients with increased tumour markers and negative MIT.

  17. Estimation of radiation dose to patients from (18) FDG whole body PET/CT investigations using dynamic PET scan protocol.

    PubMed

    Kaushik, Aruna; Jaimini, Abhinav; Tripathi, Madhavi; D'Souza, Maria; Sharma, Rajnish; Mondal, Anupam; Mishra, Anil K; Dwarakanath, Bilikere S

    2015-12-01

    There is a growing concern over the radiation exposure of patients from undergoing 18FDG PET/CT (18F-fluorodeoxyglucose positron emission tomography/computed tomography) whole body investigations. The aim of the present study was to study the kinetics of 18FDG distributions and estimate the radiation dose received by patients undergoing 18FDG whole body PET/CT investigations. Dynamic PET scans in different regions of the body were performed in 49 patients so as to measure percentage uptake of 18FDG in brain, liver, spleen, adrenals, kidneys and stomach. The residence time in these organs was calculated and radiation dose was estimated using OLINDA software. The radiation dose from the CT component was computed using the software CT-Expo and measured using computed tomography dose index (CTDI) phantom and ionization chamber. As per the clinical protocol, the patients were refrained from eating and drinking for a minimum period of 4 h prior to the study. The estimated residence time in males was 0.196 h (brain), 0.09 h (liver), 0.007 h (spleen), 0.0006 h (adrenals), 0.013 h (kidneys) and 0.005 h (stomach) whereas it was 0.189 h (brain), 0.11 h (liver), 0.01 h (spleen), 0.0007 h (adrenals), 0.02 h (kidneys) and 0.004 h (stomach) in females. The effective dose was found to be 0.020 mSv/MBq in males and 0.025 mSv/MBq in females from internally administered 18FDG and 6.8 mSv in males and 7.9 mSv in females from the CT component. For an administered activity of 370 MBq of 18FDG, the effective dose from PET/CT investigations was estimated to be 14.2 mSv in males and 17.2 mSv in females. The present results did not demonstrate significant difference in the kinetics of 18FDG distribution in male and female patients. The estimated PET/CT doses were found to be higher than many other conventional diagnostic radiology examinations suggesting that all efforts should be made to clinically justify and carefully weigh the risk-benefit ratios prior to every 18FDG whole body PET

  18. Estimation of radiation dose to patients from 18FDG whole body PET/CT investigations using dynamic PET scan protocol

    PubMed Central

    Kaushik, Aruna; Jaimini, Abhinav; Tripathi, Madhavi; D’Souza, Maria; Sharma, Rajnish; Mondal, Anupam; Mishra, Anil K.; Dwarakanath, Bilikere S.

    2015-01-01

    Background & objectives: There is a growing concern over the radiation exposure of patients from undergoing 18FDG PET/CT (18F-fluorodeoxyglucose positron emission tomography/computed tomography) whole body investigations. The aim of the present study was to study the kinetics of 18FDG distributions and estimate the radiation dose received by patients undergoing 18FDG whole body PET/CT investigations. Methods: Dynamic PET scans in different regions of the body were performed in 49 patients so as to measure percentage uptake of 18FDG in brain, liver, spleen, adrenals, kidneys and stomach. The residence time in these organs was calculated and radiation dose was estimated using OLINDA software. The radiation dose from the CT component was computed using the software CT-Expo and measured using computed tomography dose index (CTDI) phantom and ionization chamber. As per the clinical protocol, the patients were refrained from eating and drinking for a minimum period of 4 h prior to the study. Results: The estimated residence time in males was 0.196 h (brain), 0.09 h (liver), 0.007 h (spleen), 0.0006 h (adrenals), 0.013 h (kidneys) and 0.005 h (stomach) whereas it was 0.189 h (brain), 0.11 h (liver), 0.01 h (spleen), 0.0007 h (adrenals), 0.02 h (kidneys) and 0.004 h (stomach) in females. The effective dose was found to be 0.020 mSv/MBq in males and 0.025 mSv/MBq in females from internally administered 18FDG and 6.8 mSv in males and 7.9 mSv in females from the CT component. For an administered activity of 370 MBq of 18FDG, the effective dose from PET/CT investigations was estimated to be 14.2 mSv in males and 17.2 mSv in females. Interpretation & conclusions: The present results did not demonstrate significant difference in the kinetics of 18FDG distribution in male and female patients. The estimated PET/CT doses were found to be higher than many other conventional diagnostic radiology examinations suggesting that all efforts should be made to clinically justify and

  19. Value of FDG PET/CT in staging of oral cancer: four simultaneous primary malignancies.

    PubMed

    Linz, Christian; Müller-Richter, Urs D A; Kircher, Stefan; Lapa, Constantin; Bluemel, Christina

    2015-05-01

    Patients with squamous cell cancer (SCC) of the head and neck are at increased risk for second primary malignancies (SPMs). We report on a 53-year-old patient with primary diagnosis of SCC in the anterior floor of the mouth. Panendoscopy suspected an SPM of the right vocal cord. FDG PET/CT, as a whole-body imaging method, confirmed this suspicion and raised concern for further SPM of both esophagus and colon. All malignancies were confirmed by biopsy. Subsequently, the patient underwent radiochemotherapy. In summary, FDG PET/CT revealed unexpected multiple SPMs, prevented unnecessary resection of the oral SCC, and enabled individualized therapeutic management.

  20. 18F-FDG PET/CT diagnosis of vagus nerve neurolymphomatosis.

    PubMed

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

    2012-09-01

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

  1. Early detection of encephalitis with (18)F-FDG PET/CT.

    PubMed

    Gaeta, M C; Godani, M; Nunziata, R; Capellini, C; Ciarmiello, A

    2015-01-01

    Encephalitis is a relatively rare condition for which making an accurate diagnosis can be challenging. In fact, clinical features are not specific and structural imaging can be normal in a considerable number of cases. However, an early diagnosis is important as many forms of treatment are effective if started promptly. Even though recent guidelines do not recommend (18)F-FDG PET/CT for patients with suspected encephalitis, the case presented suggests that (18)F-FDG PET/CT may play a relevant role for the early diagnosis of this clinical condition. Copyright © 2014 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  2. Conjunctival Melanoma on 18F-FDG PET/CT as a Second Primary Cancer.

    PubMed

    Tsai, Szu-Ying; Shiau, Yu-Chien; Wang, Shan-Ying; Wu, Yen-Wen

    2016-03-01

    Herein we present the F-FDG PET/CT findings in conjunctival melanoma as a second primary cancer in a 56-year-old Taiwanese man with a history of small lymphocytic lymphoma/chronic lymphocytic leukemia and nasal cavity carcinoma under remission. The right eye lesion slowly progressed since noted by the patient himself 2 years ago, but he refused biopsy and further treatment including surgery. Either small lymphocytic lymphoma/chronic lymphocytic leukemia or conjunctival melanoma is extremely rare in Asians, left alone in combination with a third malignancy of nasal cavity carcinoma. FDG PET/CT could effectively evaluate malignancies with multiple primary origins.

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

    PubMed

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

    2015-01-01

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

  4. IgG4-Related Tubulointerstitial Nephritis Pattern in 18F-FDG PET/CT.

    PubMed

    Bélissant, Ophélie; Guernou, Mohamed; Rouvier, Philippe; Compain, Caroline; Bonardel, Gérald

    2015-10-01

    A 17-year-old adolescent girl was admitted with chronic arthralgia, Raynaud phenomenon, pericarditis, and evidences of chronic diffuse inflammation. F-FDG PET/CT scan was performed to search systemic vasculitis and showed diffuse moderate uptake in the kidneys. We suggested the existence of a nephritis, but the ultrasonography result was normal, and no treatment was introduced. Another F-FDG PET/CT scan was performed 7 months later to explore abdominal pain. It showed again diffuse intense uptake in both kidneys. A proteinuria was highlighted, and renal biopsy allowed to diagnose IgG4-related disease.

  5. Repeatability of the Maximum Standard Uptake Value (SUVmax) in FDG PET

    PubMed Central

    Lindholm, Henry; Staaf, Johan; Jacobsson, Hans; Brolin, Fredrik; Hatherly, Robert; Sânchez-Crespo, Alejandro

    2014-01-01

    Objective: SUVmax is often calculated at FDG PET examinations in systematic studies as well as at clinical examinations. Since SUVmax represents a very small portion of a lesion it may be questioned how statistically reliable the figure is. This was studied by assessing the repeatability of SUVmax between two FDG acquisitions acquired immediately upon each other in patients with chest lesions. Methods: In 100 clinical patients with a known chest lesion, two identical 3 min PET registrations (PET1 and PET2, respectively) were initiated within 224±31 sec of each other. The difference in SUVmax between the lesion for the two PET scans (ΔSUVmax) was calculated and the uncertainty expressed as the coefficient of variation, CV (%). The correlation between ΔSUVmax and the lowest SUVmax from PET1 or PET2, the approximate metabolic lesion volume, the time from FDG injection to PET1 and the time between PET1 and PET2, respectively, was also assessed. Results: In 56 patients SUVmax increased at the second acquisition and in 44 patients it decreased. Mean of SUVmax was 7.8±6.1 and 7.8±6.2 for PET1 and PET2, respectively. The mean percentage difference was 0.9±7.8. The difference was not significant (p=0.20). CV gave an uncertainty of 4.3% between the two measurements which is a strong indicator of equivalence. There was no correlation between ΔSUVmax and any of the assessed four parameters. The difference between the acquisitions, 0.9%, was much lower compared to the 3 previous published similar, but more restricted studies where the difference was 2.5-8.2%. Conclusion: From camera and computational perspectives, SUVmax is a stable parameter Conflict of interest:None declared. PMID:24653930

  6. Prevalence and malignancy risk of focal colorectal incidental uptake detected by 18F-FDG-PET or PET/CT: a meta-analysis

    PubMed Central

    Treglia, Giorgio; Taralli, Silvia; Salsano, Marco; Muoio, Barbara; Sadeghi, Ramin; Giovanella, Luca

    2014-01-01

    Background The aim of the study was to meta-analyze published data about prevalence and malignancy risk of focal colorectal incidentalomas (FCIs) detected by Fluorine-18-Fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (18F-FDG-PET or PET/CT). Methods A comprehensive computer literature search of studies published through July 31st 2012 regarding FCIs detected by 18F-FDG-PET or PET/CT was performed. Pooled prevalence of patients with FCIs and risk of malignant or premalignant FCIs after colonoscopy or histopathology verification were calculated. Furthermore, separate calculations for geographic areas were performed. Finally, average standardized uptake values (SUV) in malignant, premalignant and benign FCIs were reported. Results Thirty-two studies comprising 89,061 patients evaluated by 18F-FDG-PET or PET/CT were included. The pooled prevalence of FCIs detected by 18F-FDG-PET or PET/CT was 3.6% (95% confidence interval [95% CI]: 2.6–4.7%). Overall, 1,044 FCIs detected by 18F-FDG-PET or PET/CT underwent colonoscopy or histopathology evaluation. Pooled risk of malignant or premalignant lesions was 68% (95% CI: 60–75%). Risk of malignant and premalignant FCIs in Asia-Oceania was lower compared to that of Europe and America. A significant overlap in average SUV was found between malignant, premalignant and benign FCIs. Conclusions FCIs are observed in a not negligible number of patients who undergo 18F-FDG-PET or PET/CT studies with a high risk of malignant or premalignant lesions. SUV is not reliable as a tool to differentiate between malignant, premalignant and benign FCIs. Further investigation is warranted whenever FCIs are detected by 18F-FDG-PET or PET/CT. PMID:24991198

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

    PubMed Central

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

    2016-01-01

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

  8. The role of 18F-FDG-PET/ceCT in peritoneal mesothelioma.

    PubMed

    Dubreuil, Julien; Giammarile, Francesco; Rousset, Pascal; Rubello, Domenico; Bakrin, Naoual; Passot, Guillaume; Isaac, Sylvie; Glehen, Olivier; Skanjeti, Andrea

    2017-04-01

    The aim of this study was to assess glucose metabolism of multicystic peritoneal mesothelioma and epithelioid peritoneal mesothelioma by fluorine-18 fluorodeoxyglucose (F-FDG)-PET/contrast-enhanced computed tomography (ceCT) and to assess its prognostic impact. Twenty-three (14 women) patients, without previous treatment, underwent F-FDG-PET/ceCT before peritoneal mesothelioma cytoreductive surgery and intraperitoneal chemotherapy. F-FDG-PET/ceCT was interpreted prospectively as positive or negative. Maximum standardized uptake value (SUVmax) of each lesion was measured retrospectively on the basis of postsurgery data. At laparotomy, disease extension was estimated with the Peritoneal Cancer Index. The median follow-up was 27 months (95% confidence interval: 12.9-37.8); progression-free survival (PFS) was recorded. Nine patients were affected by multicystic and 14 were affected by epithelioid peritoneal mesothelioma. PET showed mild focal uptake in one case of multicystic peritoneal mesothelioma, whereas in eight patients, no abnormal uptake was observed. PET was positive in 12/14 patients with epithelioid peritoneal mesothelioma. Sensitivity, specificity and accuracy were respectively 86, 89 and 87%; the qualitative assessment was statistically different (P=0.0020, χ). Multicystic peritoneal mesothelioma histology was significantly associated with lower SUVmaxlesion (P=0.0061), SUVmaxlesion/liver (P=0.0025), Peritoneal Cancer Index, younger age, and it was observed only in women.Recurrence was observed on nine patients affected by epithelioid peritoneal mesothelioma, whereas no recurrences were observed among multicystic peritoneal mesothelioma patients. SUVmaxlesion (P=0.0278) and age (P=0.0241) were significantly associated with PFS in patients with epithelioid peritoneal mesothelioma. F-FDG-PET/ceCT showed significant differences between multicystic and epithelioid peritoneal mesothelioma, whereas SUVmaxlesion was associated with PFS in the latter. Although

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

    PubMed

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

    2016-01-01

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

  10. Advantages of (18)F FDG-PET/CT over Conventional Staging for Sarcoma Patients.

    PubMed

    Németh, Zsuzsanna; Boér, Katalin; Borbély, Katalin

    2017-10-09

    The effective management of patients with sarcomas requires accurate diagnosis and staging. Imaging, such as ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI) are the most freqently used methods for the detection of the lesion location, size, morphology and structural changes to adjacent tissues; however, these modalities provide little information about tumour biology. MRI is a robust and useful modality in tumour staging of sarcomas, however metabolic-fluorodeoxyglucose positron emission tomography/ computer tomography ((18)F-FDG PET/CT) provides greater accuracy to overall staging in combination with MRI [1]. The advantages of (18)F-FDG PET/CT method compared with CT and MRI is that it provides a whole body imaging, maps the viability of the tumour or the metabolic activity of the tissue. Additionally, PET detects the most agressive part of the tumour, demonstrates the biological behaviour of the tumour and therefore has a predictive value. Little data ara available on the role of (18)F-FDG PET/CT in the management of sarcomas. The present manuscript aims to provide a review of the major indications of (18)F-FDG PET/CT for diagnosis, staging, restaging and monitoring response to therapy and to compare its usefulness with the conventional imaging modalities in the management of patients with sarcomas.

  11. Ability of FDG-PET/CT in the detection of gallbladder cancer.

    PubMed

    Ramos-Font, Carlos; Gómez-Rio, Manuel; Rodríguez-Fernández, Antonio; Jiménez-Heffernan, Amelia; Sánchez Sánchez, Rocío; Llamas-Elvira, Jose Manuel

    2014-03-01

    To assess the value of FDG-PET/CT in the evaluation of gallbladder carcinomas (GBC). A prospective cohort of patients with suspicion of or confirmed GBC was studied with FDG-PET/CT. Diagnostic accuracy parameters were calculated in comparison with pathology and/or the clinical course of patients. Clinical impact of PET/CT imaging was estimated. Forty-nine patients were enrolled (34 malignant tumors, 15 benign lesions; 37 staging, 12 restaging). Overall diagnostic accuracy was 95.9% for the diagnosis of the primary lesion, 85.7% for lymph node involvement and 95.9% for metastatic disease. Mean SUVmax in malignant gallbladder lesions was 7.92 ± 6.25 Analysis of ROC curves showed a SUVmax cut-off value of 3.62 for malignancy (S: 78.1%; Sp: 88.2%). Diagnostic accuracy in the restaging group reached 100%. FDG-PET/CT changed the management of 22.4% of the population. Diagnosis of malignancy or benignity of suspicious gallbladder lesions is accurately made with FDG PET/CT, allowing a precise staging of GBC due to its ability to identify unsuspected metastatic disease. SUVmax has a complementary role in addition to visual analysis. © 2013 Wiley Periodicals, Inc.

  12. Sestamibi and FDG-PET scans to support diagnosis of jaw osteonecrosis.

    PubMed

    Catalano, Lucio; Del Vecchio, Silvana; Petruzziello, Fara; Fonti, Rosa; Salvatore, Barbara; Martorelli, Carmen; Califano, Catello; Caparrotti, Giuseppe; Segreto, Sabrina; Pace, Leonardo; Rotoli, Bruno

    2007-06-01

    Osteonecrosis of the maxillary or mandibular bone is an infrequent but often severe event occurring in patients who undergo prolonged treatment with bisphosphonates. Histology is in some cases mandatory to differentiate it from neoplastic osteolysis, but a biopsy can further contribute to bone damage. Functional imaging obtained by a tracer that shows oncotropic properties, such as Tc99m-sestamibi, in comparison to a non-tumor-specific substance such as FDG-PET, can support the differential diagnosis, thus avoiding invasive procedures. Four patients affected by multiple myeloma and jaw osteonecrosis were prospectively evaluated by sestamibi and FDG-PET scans. Local diagnosis was performed by clinical, radiological and, in some cases, histological evaluations. Each patient was studied by Tc99m-sestamibi, performed by planar anterior and posterior whole-body scans and SPECT of the head and neck, and by PET/CT. Two nuclear medicine physicians, unaware of the final diagnosis, reviewed the images. No sestamibi uptake was evident in the four patients with jaw osteonecrosis, while FDG-PET/CT showed focal uptake in all of them. Our study suggests that the combined use of sestamibi scintigraphy and FDG-PET/CT could support the clinical diagnosis of oral osteonecrosis avoiding the risks of a surgical biopsy. Studies on higher number of patients are necessary to validate these preliminary observations.

  13. 68Ga-Chloride PET Reveals Human Pancreatic Adenocarcinoma Xenografts in Rats—Comparison with FDG

    PubMed Central

    Ujula, Tiina; Salomäki, Satu; Autio, Anu; Luoto, Pauliina; Tolvanen, Tuula; Lehikoinen, Pertti; Viljanen, Tapio; Sipilä, Hannu; Härkönen, Pirkko

    2009-01-01

    Purpose The aim of the study was to compare 68Ga-chloride with 2-[18F]fluoro-2-deoxy-d-glucose (FDG) for the imaging of pancreatic xenografts. Procedures Rats with subcutaneous human pancreatic adenocarcinoma xenografts were evaluated in vivo by dynamic positron emission tomography (PET) and ex vivo by measuring radioactivity of excised tissues and by digital autoradiography of tumor cryosections. Results Both tracers were capable of delineating all subcutaneous tumors from surrounding tissues by PET. The standardized uptake values of tumors by PET were 0.9 ± 0.3 (mean ± SD) for 68Ga-chloride (n = 13) and 1.8 ± 1.2 for FDG (n = 11). Ex vivo studies showed tumor-to-muscle ratio of 4.0 ± 0.3 for 68Ga-chloride (n = 4) and 7.9 ± 3.2 for FDG (n = 4). Conclusions 68Ga-chloride delineated subcutaneously implanted pancreatic adenocarcinoma xenografts by PET, but the uptake was lower than FDG. Further studies to clarify the value of 68Ga-chloride for PET imaging of tumors are warranted. PMID:19798536

  14. Intraindividual homogeneity of (18)F-FDG PET/CT parameters in HPV-positive OPSCC.

    PubMed

    Sharma, Shachi Jenny; Wittekindt, Claus; Knuth, Jennifer; Steiner, Dagmar; Wuerdemann, Nora; Laur, Maren; Kroll, Tobias; Wagner, Steffen; Klussmann, Jens Peter

    2017-10-01

    (18)F-FDG PET/CT is widely used in clinical oncology. Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) represents an emerging disease that differs from HPV-negative OPSCC in clinical behavior and tumour biology. In these tumours, HPV-oncogenes might lead to distinct alterations in metabolic pathways. Therefore, we compared metabolic parameters using (18)F-FDG PET/CT in HPV-positive and HPV-negative OPSCC in relation to histopathological findings. Eighty-six patients with OPSCC received pre-therapeutic (18)F-FDG PET/CT. Standardised uptake volume (SUV), total lesion glycolysis (TLG) and metabolic tumour volume (MTV) were analysed for the primary tumour. SUVmax was determined for neck lymph nodes. HPV-status was determined; overall survival rates (OS) were estimated. 32/86 patients (37.2%) had HPV-related OPSCC. Overall, PET-parameters in primary tumours of both groups did not differ significantly. Comparing early with locally advanced primary tumours, there was a significant increase in (18)F-FDG uptake in HPV-negative patients (p<0.001). Positive nodes of HPV-related OPSCC showed significantly higher SUVmax values (p=0.039) compared to HPV-negative OPSCC. Strikingly, there was a higher intraindividual homogeneity of (18)F-FDG uptake between primary and respective positive nodes in HPV-related primary OPSCC (p=0.001). SUV-max and -mean values did not correlate with OS in HPV-related OPSCC. The intraindividual homogeneity of 18F-FDG uptake in HPV-related OPSCC could reflect the more homogenously, HPV-triggered carcinogenesis compared to the mutation-driven carcinogenesis in the HPV-negative OPSCC with heterogenic (18)F-FDG uptake. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2011-07-01

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

  16. Evaluation of brain SERT occupancy by resveratrol against MDMA-induced neurobiological and behavioral changes in rats: A 4-[¹⁸F]-ADAM/small-animal PET study.

    PubMed

    Shih, Jui-Hu; Ma, Kuo-Hsing; Chen, Chien-Fu F; Cheng, Cheng-Yi; Pao, Li-Heng; Weng, Shao-Ju; Huang, Yuahn-Sieh; Shiue, Chyng-Yann; Yeh, Ming-Kung; Li, I-Hsun

    2016-01-01

    The misuse of 3,4-methylenedioxymethamphetamine (MDMA) has drawn a growing concern worldwide for its psychophysiological impacts on humans. MDMA abusers are often accompanied by long-term serotonergic neurotoxicity, which is associated with reduced density of cerebral serotonin transporters (SERT) and depressive disorders. Resveratrol (RSV) is a natural polyphenolic phytoalexin that has been known for its antidepressant and neuroprotective effects. However, biological targets of RSV as well as its neuroprotective effects against MDMA remained largely unknown. In this study, we examined binding potency of RSV and MDMA to SERT using small-animal positron emission tomography (PET) with the SERT radioligand, N,N-dimethyl-2-(2-amino-4-[(18)F]fluorophenylthio)benzylamine (4-[(18)F]-ADAM) and investigated the protection of RSV against the acute and long-term adverse effects of MDMA. We found that RSV exhibit binding potentials to SERT in vivo in a dose-dependent manner with variation among brain regions. When the MDMA-treated rats (10mg/kg, s.c.) were co-injected with RSV (20mg/kg, i.p.) twice daily for 4 consecutive days, MDMA-induced acute elevation in plasma corticosterone was significantly reduced. Further, 4-[(18)F]-ADAM PET imaging revealed that RSV protected against the MDMA-induced decrease in SERT availability in the midbrain and the thalamus 2 weeks following the co-treatment. The PET data were comparable to the observation from the forced swim test that RSV sufficiently ameliorated the depressive-like behaviors of the MDMA-treated rats. Together, these findings suggest that RSV is a potential antidepressant and may confer protection against neurobiological and behavioral changes induced by MDMA.

  17. Diagnostic contribution of (18)F-FDG-PET/CT in fever of unknown origin.

    PubMed

    Tokmak, Handan; Ergonul, Onder; Demirkol, Onur; Cetiner, Mustafa; Ferhanoglu, Burhan

    2014-02-01

    Fever of unknown origin (FUO) remains one of the most compelling diagnostic issues in medicine. We aimed to evaluate the potential clinical contribution of 18-fluoro-2-deoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) in the identification of the underlying cause of FUO. Fifty consecutive patients (27 men and 23 women; age range 16-88 years) with FUO based on the revised definition criteria were included in the study. A diagnostic protocol including biochemistry, histopathology, and microbiological tests was performed and the patients were followed up. FDG-PET was performed in 25 of the 50 patients (12 males and 13 females; age range 16-88 years) in order to determine the etiology of the patient's fever. PET-CT images were obtained with the Gemini Philips TF (18)F-FDG-PET/CT camera after a 60-min 'standard uptake' period following an injection of a mean 330 MBq (range 290-370 MBq) intravenous (18)F-FDG. A total of 21 patients were available for analysis of the diagnostic contribution of PET/CT (two patients were undiagnosed and two had non-contributory PET/CT findings). (18)F-FDG-PET/CT was able to precisely detect the cause of fever in 60% of the cases (n=15). The accuracy, sensitivity, and specificity of this imaging modality were 90.5%, 93.8%, and 80%, respectively. Among the cases with a true-positive (18)F-FDG-PET/CT finding (i.e., 15 cases), the identified underlying causes of FUO included localized infection (n=7), non-infective inflammatory process (n=5), and malignancy (n=3). Further studies to confirm the high diagnostic yield of (18)F-FDG-PET/CT observed in the present study would lend support to the inclusion of this imaging modality in the initial diagnostic work-up of patients with suspected FUO. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    SciTech Connect

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

    2008-05-01

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

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

    PubMed

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

    2013-11-01

    Extensive screening strategies to detect occult cancer in patients with unprovoked venous thromboembolism (VTE) are complex and no benefit in terms of survival has been reported. FDG-PET/CT (2-[F-18] fluoro-2-deoxy-D-glucose positron emission tomography combined with computed tomography), a noninvasive technique for the diagnosis and staging of malignancies, could be useful in this setting. Consecutive patients ≥ 50 years with a first unprovoked VTE episode were prospectively included. Screening with FDG-PET/CT was performed 3-4 weeks after the index event. If positive, appropriate diagnostic work-up was programmed. Clinical follow-up continued for 2 years. Blood samples were collected to assess coagulation biomarkers. FDG-PET/CT was negative in 68/99 patients (68.7%), while suspicious FDG uptake was detected in 31/99 patients (31.3%). Additional diagnostic work-up confirmed a malignancy in 7/31 patients (22.6%), with six of them at early stage. During follow-up, two patients with negative FDG-PET/CT were diagnosed with cancer. Sensitivity (S), positive (PPV) and negative predictive values (NPV) of FDG-PET/CT as single tool for the detection of occult malignancy were 77.8% (95% CI: 0.51-1), 22.6% (95% CI: 0.08-0.37) and 97.1% (95% CI: 0.93-1), respectively. Median tissue factor (TF) activity in patients with occult cancer was 5.38 pM vs. 2.40 pM in those without cancer (p = 0.03). Limitation of FDG-PET/CT screening to patients with TF activity > 2.8 pM would improve the PPV to 37.5% and reduce the costs of a single cancer diagnosis from 20,711€ to 11,670€. FDG-PET/CT is feasible for the screening of occult cancer in patients with unprovoked VTE, showing high S and NPV. The addition of TF activity determination may be useful for patient selection. Copyright © 2013 UICC.

  20. The clinical utility of FDG PET/CT among solid organ transplant recipients suspected of malignancy or infection.

    PubMed

    Wareham, Neval E; Lundgren, J D; Da Cunha-Bang, C; Gustafsson, F; Iversen, M; Johannesen, H H; Kjær, A; Rasmussen, A; Sengeløv, H; Sørensen, S S; Fischer, B M

    2017-03-01

    Solid organ transplant (SOT) recipients are at high risk of developing infections and malignancies. (18)F-FDG PET/CT may enable timely detection of these diseases and help to ensure early intervention. We aimed to describe the clinical utility of FDG PET/CT in consecutive, diagnostic unresolved SOT recipients transplanted from January 2004 to May 2015. Recipients with a post-transplant FDG PET/CT performed as part of diagnostic work-up were included. Detailed chart reviews were done to extract relevant clinical information and determine the final diagnosis related to the FDG PET/CT. Based on á priori defined criteria and the final diagnosis, results from each scan were classified as true or false, and diagnostic values determined. Among the 1,814 recipients in the cohort, 145 had an FDG PET/CT performed; 122 under the indication of diagnostically unresolved symptoms with a suspicion of malignancy or infection. The remaining (N = 23) had an FDG PET/CT to follow-up on a known disease or to stage a known malignancy. The 122 recipients underwent a total of 133 FDG PET/CT scans performed for a suspected malignancy (66 %) or an infection (34 %). Sensitivity, specificity, and positive and negative predictive values of the FDG PET/CT in diagnosing these conditions were 97, 84, 87, and 96 %, respectively. FDG PET/CT is an accurate diagnostic tool for the work-up of diagnostic unresolved SOT recipients suspected of malignancy or infection. The high sensitivity and NPV underlines the potential usefulness of PET/CT for excluding malignancy or focal infections in this often complex clinical situation.

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

    PubMed

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

    2017-03-01

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

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

    PubMed Central

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

    2012-01-01

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

  3. Concurrent Diffuse Pyelonephritis and Prostatitis: Discordant Findings on Sequential FDG PET/CT and 67Ga SPECT/CT Imaging.

    PubMed

    Lucaj, Robert; Achong, Dwight M

    2017-01-01

    A 45-year-old man underwent FDG PET/CT for initial imaging evaluation of recurrent Escherichia coli urinary tract infections, which demonstrated no significant FDG uptake in either kidney and subtle FDG uptake in the right prostate lobe. Subsequent Ga SPECT/CT demonstrated abnormal intense gallium uptake throughout the right kidney and entire prostate gland, clearly discordant with PET/CT findings and consistent with unexpected concurrent pyelonephritis and prostatitis. Although FDG has effectively replaced Ga in everyday clinical practice, the current case serves as a reminder that there is still a role for Ga in the evaluation of genitourinary infections.

  4. Clinical utility of FDG PET/CT in acute complicated pyelonephritis-results from an observational study.

    PubMed

    Wan, Chih-Hsing; Tseng, Jing-Ren; Lee, Ming-Hsun; Yang, Lan-Yan; Yen, Tzu-Chen

    2017-09-26

    Acute complicated pyelonephritis (ACP) is an upper urinary tract infection associated with coexisting urinary tract abnormalities or medical conditions that could predispose to serious outcomes or treatment failures. Although CT and magnetic resonance imaging (MRI) are frequently used in patients with ACP, the clinical value of (18)F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) has not been systematically investigated. This single-center retrospective study was designed to evaluate the potential usefulness of FDG PET/CT in patients with ACP. Thirty-one adult patients with ACP who underwent FDG PET/CT were examined. FDG PET/CT imaging characteristics, including tracer uptake patterns, kidney volumes, and extrarenal imaging findings, were reviewed in combination with clinical data and conventional imaging results. Of the 31 patients, 19 (61%) showed focal FDG uptake. The remaining 12 study participants showed a diffuse FDG uptake pattern. After volumetric approximation, the affected kidneys were found to be significantly enlarged. Patients who showed a focal uptake pattern had a higher frequency of abscess formation requiring drainage. ACP patients showing diffuse tracer uptake patterns had a more benign clinical course. Seven patients had suspected extrarenal coinfections, and FDG PET/CT successfully confirmed the clinical suspicion in five cases. FDG PET/CT was as sensitive as CT in identifying the six patients (19%) who developed abscesses. Notably, FDG PET/CT findings caused a modification to the initial antibiotic regimen in nine patients (29%). FDG PET/CT may be clinically useful in the assessment of patients with ACP who have a progressive disease course.

  5. Detection of local tumor progression by (18)F-FDG PET/CT following lung radiofrequency ablation: PET versus CT.

    PubMed

    Suzawa, Naohisa; Yamakado, Koichiro; Takao, Motoshi; Taguchi, Osamu; Yamada, Tomomi; Takeda, Kan

    2013-04-01

    The objective of this study was to compare the diagnostic performance for detecting local tumor progression between FDG PET and CT in patients who received lung radiofrequency (RF) ablation for the treatment of malignant lung tumors. A total of 469 FDG PET/CT studies were performed at 4 time points (3, 6, 9, 12 months) after lung RF ablation in 143 patients (87 male and 56 female patients) with 231 tumors. The SUVmax was calculated in treated tumors in each PET image. The percentage decrease (% decrease) in ablative zone size was evaluated in each CT image. The final response was judged based on follow-up findings and histology. Diagnostic performance of FDG PET and CT images was evaluated using receiver operating characteristic analysis. Local tumor progression was identified in 37 patients (25.9%, 37/143) having 47 tumors (20.4%, 47/231) during the median follow-up of 24 months (range, 8-75 months). The area under the receiver operating characteristic curve of PET was higher than that of CT at all 4 time points (0.71 vs 0.55 at 3 months, 0.82 vs 0.60 at 6 months, 0.84 vs 0.66 at 9 months, and 0.92 vs 0.68 at 12 months), and its diagnostic performance was significant at each time point (P = 0.0010 at 3 months and P < 0.001 at 6, 9, and 12 months). However, the area under the receiver operating characteristic curve of CT was significant at 9 months (P = 0.040) and 12 months (P = 0.032). FDG PET/CT is better able to assess local tumor progression at 3 and 6 months after lung RF ablation than CT alone.

  6. (18)F-FDG PET/CT delayed images with forced diuresis for revaluating abdominopelvic malignancies.

    PubMed

    Wang, Hui-Chun; Wang, Zhi-Min; Wang, Yu-Bin; Chen, Xiao-Hong; Cui, Lan-Lan

    2017-05-01

    The aim of this retrospective study was to evaluate the role of delayed images after forced diuresis coupled with oral hydration in abdominopelvic (18)F-FDG PET/CT. Forty-six patients consisting of 17 urological diseases, 9 gynecological tumors, 18 colorectal malignancies, and 2 cancers of unknown primary site were retrospectively analyzed. All patients who presented with indeterminate or equivocal abdominopelvic foci on standard (18)F-FDG PET/CT underwent a delayed abdominopelvic imaging after administration of 20 mg furosemide intravenously and extra water intake of 500 mL. PET/CT images before and after furosemide were compared with each other and their findings correlated with pathology or clinical follow-up (>6 months). On initial PET/CT, the glucose metabolism characters of lesions were disguised by radioactive urine, or some undetermined (18)F-FDG accumulating foci near the urinary tract appeared. While postdiuretic PET/CT demonstrated an excellent urinary tracer washout, and hypermetabolic lesions could be clearly detected and precisely localized in all cases. On the other hand, the suspected active foci caused by potential stagnation of excreted (18)F-FDG in urinary tract were eliminated. The sensitivity, specificity, and accuracy were 94.4% (34/36), 8/10, 91.3% (42/46), respectively. Furthermore, the additional lesions with surrounding invasion or locoregional metastasis were discovered in 8 of 46 (17.4%) patients only by the delayed images, including 2 gynecological and 6 rectal malignancies. Detection of abdominopelvic malignancies can be improved using delayed (18)F-FDG PET/CT images after a diuretic and oral hydration.

  7. Role of (18)F-FDG PET/CT in primary brain lymphoma.

    PubMed

    de-Bonilla-Damiá, Á; Fernández-López, R; Capote-Huelva, F J; de la Cruz-Vicente, F; Egea-Guerrero, J J; Borrego-Dorado, I

    To study the usefulness of (18)F-FDG PET/CT in the initial evaluation and in the response assessment in primary brain lymphoma. A retrospective analysis was carried out on 18 patients diagnosed with primary brain lymphoma, a histological subtype of diffuse large B-cell lymphoma, on whom an initial (18)F-FDG PET/CT and MRI was performed, with 7 of the cases being analysed after the completion of treatment in order to assess response and clinical follow up. Initial (18)F-FDG PET/CT showed 26 hypermetabolic foci, whereas 46 lesions were detected by MRI. The average SUV maximum of the lesions was 17.56 with T/N 3.55. The concordance of both tests for identifying the same number of lesions was moderate, obtaining a kappa index of 0.395 (P<.001). In the evaluation of treatment, MRI identified 16 lesions compared to 7 pathological accumulations observed by (18)F-FDG PET/CT. The concordance of both tests to assess type of response to treatment was moderate (kappa index 0.41) (P=.04). In both the initial evaluation and the assessment of the response to treatment, PET/CT led to a change strategy in 22% of patients who had lesions outside the cerebral parenchyma. MRI appears to be the method of choice for detecting brain disease in patients with primary brain lymphoma, whereas (18)F-FDG PET/CT seems to play a relevant role in the assessment of extra-cerebral disease. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

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

    PubMed

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

    2001-08-01

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

  9. Comparison of (18)FDG PET/PET-CT and bone scintigraphy for detecting bone metastases in patients with nasopharyngeal cancer: a meta-analysis.

    PubMed

    Xu, Chuanhui; Zhang, Ruiming; Zhang, Huanlei; Zhang, Zhenyan

    2017-08-29

    We performed a meta-analysis to compare the diagnostic efficacy of (18)FDG PET/PET-CT and bone scintigraphy (BS) for diagnosing bone metastatic cancers in nasopharyngeal cancer patients. 6 studies (1238 patients) fulfilled the inclusion criteria. The pooled sensitivities for (18)FDG PET/PET-CT and BS were 0.81 (95% confidence interval [CI] = 0.70 to 0.98) and 0.39 (95% CI = 0.26 to 0.54), specificities were 0.99 (95% CI = 0.98 to 0.99) and 0.98 (95% CI = 0.96 to 0.99), and the areas under curve were 0.98 (95% CI = 0.97 to 0.99) and 0.84 (95% CI = 0.81 to 0.87). Several databases were searched for all available articles. We calculated the sensitivities, specificities, diagnostic odds ratios, likelihood ratios, and area under summary receiver operating characteristic curves for (18)FDG PET/PET-CT and BS, respectively. (18)FDG PET/PET-CT is superior to BS for diagnosing bone metastases in nasopharyngeal cancer patients.(18)FDG PET/PET-CT may enhance the diagnosis of bone metastases and provide more accurate information for the optimal management of nasopharyngeal cancer.

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

    PubMed

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

    2010-04-01

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

  11. Dual-time-point [18F]-FDG PET/CT in the diagnostic evaluation of suspicious breast lesions.

    PubMed

    Caprio, M G; Cangiano, A; Imbriaco, M; Soscia, F; Di Martino, G; Farina, A; Avitabile, G; Pace, L; Forestieri, P; Salvatore, M

    2010-03-01

    The authors sought to evaluate whether the reacquisition of images 3 h after administration of radiotracer improves the sensitivity of fluorine-18 fluorodeoxyglucose positron emission tomography computed tomography ([(18)F]-FDG PET/CT) in patients with suspicious breast lesions. Forty-eight patients with 59 breast lesions underwent an [(18)F]-FDG PET/CT study in the prone position with a dual-time-point acquisition performed in the early phase 1 h after FDG administration (PET-1) and in the delayed phase 3 h after FDG administration (PET-2). Both examinations were evaluated qualitatively and semiquantitatively with calculation of the mean percentage variation of the standard uptake values (Delta% SUV(max)) between PET-1 and PET-2. All lesions with an SUV(max) >or=2.5 at PET-1 or a reduction in SUV between PET-1 and PET-2 were considered benign. The definitive histopathological diagnosis was available for all patients included in the study. The dual-time-point acquisition of [(18)F]-FDG PET/CT displayed an accuracy of 85% for lesions with an SUV(max) >or=2.5 and/or positive Delta% SUV(max), with sensitivity and specificity values of 81% and 100% compared with 69%, 63% (both p<0.001) and 100% (p=n.s.), respectively, for the single-time-point acquisition. Malignant lesions showed an increase in FDG uptake between PET-1 and PET-2, with a Delta% SUV(max) of 10+/-7 (p<0.04). In contrast, benign lesions showed a decrease in SUV between PET-1 and PET-2, with a Delta% SUV(max) of -21+/-7 (p<0.001). The delayed repeat acquisition of PET images improves the accuracy of [(18)F]-FDG PET/CT in patients with suspicious breast lesions with respect to the single-time-point acquisition. In addition, malignant breast lesions displayed an increase in FDG uptake over time, whereas benign lesions showed a reduction. These variations in FDG uptake between PET-1 and PET-2 are a reliable parameter that can be used for differentiating between benign and malignant breast lesions.

  12. Rheumatic fever: a forgotten but still existing cause of fever of unknown origin detected on FDG PET/CT.

    PubMed

    Sathekge, Mike; Stoltz, Anton; Gheysens, Olivier

    2015-03-01

    We present a case of heterogeneous and strongly increased myocardial and valvular 18F-FDG uptake on 18F-FDG PET/CT in an HIV-positive patient with productive cough, fever, weight loss, and progressive dyspnea for 6 months. Contrast-enhanced CT did not reveal the cause of fever, but hyperechogenic valvular lesions on echocardiography in combination with PET/CT findings are suggestive of endocarditis/myocarditis. Postmortem histology 3 weeks after PET/CT showed Aschoff bodies with Anitschkow cells, pathognomonic for rheumatic carditis. This case illustrates that rheumatic heart disease can be detected on 18F-FDG PET/CT and demonstrates the value of 18F-FDG PET/CT in patients with fever of unknown origin.

  13. Granulocytic sarcoma of the pancreas on 18F-FDG PET/CT

    PubMed Central

    Ishii, Akira; Kondo, Tadakazu; Oka, Tomomi; Nakamoto, Yuji; Takaori-Kondo, Akifumi

    2016-01-01

    Abstract Rationale: Granulocytic sarcoma (GS) is defined as leukemia infiltration in any organ other than the bone marrow. GS rarely occurs in the pancreas. Here, we present the first report of GS in the pancreas on 18F-fluorodexyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Patient concerns: A 19-year-old male patient with acute myeloid leukemia received a human leukocyte antigen-haploidentical stem cell transplant as a second transplant while in second complete remission. Interventions: After a second stem cell transplant, obstructive pancreatitis accompanied by a mass in the pancreatic head was observed. FDG-PET/CT revealed abnormal activity in the head of the pancreas and the skin in the patient's left breast area. Diagnoses: Pathological examination demonstrated relapsed acute myeloid leukemia in both the lesions. Outcomes: This is the first report showing the 18F-FDG PET/CT findings of GS in the pancreas. Lessons: 18F-FDG PET/CT may help determine the stage of GS. PMID:27930567

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

    PubMed

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

    2016-10-01

    Positron emission tomography (PET) with fluor-18-deoxy-glucose (FDG) is widely used for diagnosing recurrent or metastatic disease in patients with differentiated thyroid cancer (DTC). To assess the diagnostic accuracy of FDG-PET for DTC in patients after ablative therapy. A systematic search was conducted in Medline/PubMed, EMBASE, Cochrane Library, Web of Science, and Open Grey looking for all English-language original articles on the performance of FDG-PET in series of at least 20 patients with DTC having undergone ablative therapy including total thyroidectomy. Diagnostic performance measures were pooled using Reitsma's bivariate model. Thirty-four publications between 1996 and 2014 met the inclusion criteria. Pooled sensitivity and specificity were 79.4% (95% confidence interval [CI], 73.9-84.1) and 79.4% (95% CI, 71.2-85.4), respectively, with an area under the curve of 0.858. F18-FDG-PET is a useful method for detecting recurrent DTC in patients having undergone ablative therapy. © The Foundation Acta Radiologica 2015.

  15. An unusual orbital localization of wegener granulomatosis detected by 18F-FDG PET/CT.

    PubMed

    Bertagna, Francesco; Treglia, Giorgio; Rossini, Pierluigi; Giubbini, Raffaele

    2014-08-01

    We report a case of a 61-year-old male patient affected by Wegener granulomatosis and left exophthalmos who underwent F-FDG PET/CT during follow-up for rectal cancer. The study was negative for secondary lesions but revealed high uptake at the left orbital mass consistent with Wegener granulomatosis.

  16. [Postoperative follow-up of gastric adenocarcinoma with neoplastic markers and 18-FDG-PET/TC].

    PubMed

    Patriti, Alberto; Graziosi, Luigina; Baffa, Nicodemo; Pacifico, Eugenio; Lamprini, Papaefthimiou; Valiani, Saverio; Gullà, Nino; Donini, Annibale

    2007-01-01

    The usefulness of tumour markers CEA, CA19.9 and CA72.4 in association with FDG-PET/TC were prospectively evaluated in the post-operative follow-up of gastric cancer patients. Fifty one consecutive patients were enrolled in a follow-up programme entailing with periodical clinical evaluations, instrumental examinations and tumour markers assay FDG-PET/TC was performed only in cases of suspected recurrence. Sensitivity of CEA, CA19.9 e CA72.4 during the follow-up period was respectively: 16%, 33.3% e 50%. Overall sensitivity was 66.6%. Specificity was 100% for CEA, 93.3% for CA19.9, 100% for CA72.4, with an overall specificity of 96.2%. FDG-PET/TC had a sensitivity of 100%. Tumour markers in association with FDG-PET/TC allow an early identification of recurrences after surgery, with the advantage to start chemotherapy or surgical protocols before the tumour has reached an advanced stage.

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

    PubMed

    Nguyen, Ba D; Roarke, Michael C

    2007-01-01

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

  18. Brain FDG-PET changes in ALS and ALS-FTD.

    PubMed

    Renard, Dimitri; Collombier, Laurent; Castelnovo, Giovanni; Fourcade, Genevieve; Kotzki, Pierre-Olivier; LaBauge, Pierre

    2011-12-01

    FDG-PET in ALS most typically demonstrates a primary (and sometimes also supplementary) motor cortex hypometabolism, often associated with more diffuse cortical hypometabolism involving mostly the dorsolateral prefrontal cortex, the medial and lateral premotor cortices, and the bilateral insular cortex involvement. In ALS-FTD, extensive temporal hypometabolism is seen in addition to severe diffuse frontal hypometabolism. This study analyses FDG-PET findings in 6 ALS patients and 4 ALS-FTD patients. In addition to earlier described areas of hypometabolism in ALS, we found also reduced FDG-PET metabolism in the medial frontal cortex, the orbitofrontal cortex, and the anterior temporal lobe in our ALS patients. The anterolateral area was the best preserved part of the frontal lobe in ALS patients. In ALS-FTD, frontal and temporal hypometabolism was severe (and parietal hypometabolism was often also present) with relatively preserved perirolandic metabolism. In ALS, more diffuse frontal and temporal FDG-PET hypometabolism was seen than earlier reported, with the anterolateral area as the best preserved part of the frontal lobe. In ALS-FTD, relatively preserved perirolandic metabolism was seen, associated with severe frontal and temporal hypometabolism.

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

    PubMed Central

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

    2017-01-01

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

  20. Bone Windows for Distinguishing Malignant from Benign Primary Bone Tumors on FDG PET/CT

    PubMed Central

    Costelloe, Colleen M.; Chuang, Hubert H.; Chasen, Beth A.; Pan, Tinsu; Fox, Patricia S.; Bassett, Roland L.; Madewell, John E.

    2013-01-01

    Objective. The default window setting on PET/CT workstations is soft tissue. This study investigates whether bone windowing and hybrid FDG PET/CT can help differentiate between malignant and benign primary bone tumors. Materials and methods. A database review included 98 patients with malignant (n=64) or benign primary bone (n=34) tumors. The reference standard was biopsy for malignancies and biopsy or >1 year imaging follow-up of benign tumors. Three radiologists and/or nuclear medicine physicians blinded to diagnosis and other imaging viewed the lesions on CT with bone windows (CT-BW) without and then with PET (PET/CT-BW), and separate PET-only images for malignancy or benignity. Three weeks later the tumors were viewed on CT with soft tissue windows (CT-STW) without and then with PET (PET/CT-STW). Results. Mean sensitivity and specificity for identifying malignancies included: CT-BW: 96%, 90%; CT-STW: 90%, 90%; PET/CT-BW: 95%, 85%, PET/CT-STW: 95%, 86% and PET-only: 96%, 75%, respectively. CT-BW demonstrated higher specificity than PET-only and PET/CT-BW (p=0.0005 and p=0.0103, respectively) and trended toward higher sensitivity than CT-STW (p=0.0759). Malignant primary bone tumors were more avid than benign lesions overall (p<0.0001) but the avidity of benign aggressive lesions (giant cell tumors and Langerhans Cell Histiocytosis) trended higher than the malignancies (p=0.08). Conclusion. Bone windows provided high specificity for distinguishing between malignant and benign primary bone tumors and are recommended when viewing FDG PET/CT. PMID:23983816

  1. Bone Windows for Distinguishing Malignant from Benign Primary Bone Tumors on FDG PET/CT.

    PubMed

    Costelloe, Colleen M; Chuang, Hubert H; Chasen, Beth A; Pan, Tinsu; Fox, Patricia S; Bassett, Roland L; Madewell, John E

    2013-01-01

    Objective. The default window setting on PET/CT workstations is soft tissue. This study investigates whether bone windowing and hybrid FDG PET/CT can help differentiate between malignant and benign primary bone tumors. Materials and methods. A database review included 98 patients with malignant (n=64) or benign primary bone (n=34) tumors. The reference standard was biopsy for malignancies and biopsy or >1 year imaging follow-up of benign tumors. Three radiologists and/or nuclear medicine physicians blinded to diagnosis and other imaging viewed the lesions on CT with bone windows (CT-BW) without and then with PET (PET/CT-BW), and separate PET-only images for malignancy or benignity. Three weeks later the tumors were viewed on CT with soft tissue windows (CT-STW) without and then with PET (PET/CT-STW). Results. Mean sensitivity and specificity for identifying malignancies included: CT-BW: 96%, 90%; CT-STW: 90%, 90%; PET/CT-BW: 95%, 85%, PET/CT-STW: 95%, 86% and PET-only: 96%, 75%, respectively. CT-BW demonstrated higher specificity than PET-only and PET/CT-BW (p=0.0005 and p=0.0103, respectively) and trended toward higher sensitivity than CT-STW (p=0.0759). Malignant primary bone tumors were more avid than benign lesions overall (p<0.0001) but the avidity of benign aggressive lesions (giant cell tumors and Langerhans Cell Histiocytosis) trended higher than the malignancies (p=0.08). Conclusion. Bone windows provided high specificity for distinguishing between malignant and benign primary bone tumors and are recommended when viewing FDG PET/CT.

  2. Sinonasal oncocytic Schneiderian papilloma accompanied by intravascular lymphoma: A case report on FDG-PET/CT imaging.

    PubMed

    Koyama, Masamichi; Terauchi, Takashi; Koizumi, Mitsuru; Tanaka, Hiroko; Takeuchi, Kengo

    2016-08-01

    F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is useful for the staging and assessment of treatment response in patients with lymphoma. Occasionally, benign lesions demonstrate avid FDG uptake and result in false positive findings. We report the case of an 82-year-old man presenting with cutaneous lesions, which were histopathologically diagnosed as intravascular lymphoma. FDG-PET/CT for staging demonstrated an FDG-avid mass extending from the right maxillary sinus to the nasal cavity, moderate uptake in the adrenal glands, mild uptake in the knee and the foot, and faint uptake in the skin and subcutaneous tissue of the legs. He subsequently underwent biopsy of the paranasal mass, which was diagnosed as oncocytic Schneiderian papilloma without lymphoma invasion. Glucose transporter (GLUT) 1 staining was highly positive in the papilloma cells, resulting in high FDG avidity. After completion of chemotherapy, the abnormal FDG uptakes in the skin, soft tissue, and adrenal glands disappeared on PET/CT. However, avid FDG uptake persisted in the sinonasal Schneiderian papilloma for 15 months before regression. Benign tumors with oncocytic components may show avid FDG uptake. Therefore, correct diagnosis of oncocytic Schneiderian papilloma on FDG images is difficult when other accompanying malignant tumors, especially lymphoma, are present. If post-therapeutic PET/CT images show a discordant lesion, oncocytic tumors, albeit uncommon, should be considered in the differential diagnoses.

  3. Thyroid Incidentalomas on (18)F-FDG PET/CT: Clinical Significance and Controversies.

    PubMed

    Makis, William; Ciarallo, Anthony

    2017-10-03

    The purpose of the current study is to examine the incidence and clinical significance of unexpected focal uptake of (18)F-fluorodeoxyglucose ((18)F-FDG) on positron emission tomography/computed tomography (PET/CT) in the thyroid gland of oncology patients, the maximum standardized uptake value (SUVmax) of benign and malignant thyroid incidentalomas in these patients, and review the literature. Seven thousand two hundred fifty-two (18)F-FDG PET/CT studies performed over four years, were retrospectively reviewed. Studies with incidental focal (18)F-FDG uptake in the thyroid gland were further analyzed. Incidental focal thyroid (18)F-FDG uptake was identified in 157 of 7252 patients (2.2%). Sufficient follow-up data (≥12 months) were available in 128 patients, of whom 57 (45%) had a biopsy performed and 71 had clinical follow-up. Malignancy was diagnosed in 14 of 128 patients (10.9%). There was a statistically significant difference between the median SUVmax of benign thyroid incidentalomas (SUVmax 4.8) vs malignant (SUVmax 6.3), but the wide range of overlap between the two groups yielded no clinically useful SUVmax threshold value to determine malignancy. (18)F-FDG positive focal thyroid incidentalomas occurred in 2.2% of oncologic PET/CT scans, and were malignant in 10.9% of 128 patients. This is the lowest reported malignancy rate in a North American study to date, and significantly lower than the average malignancy rate (35%) reported in the literature. Invasive biopsy of all (18)F-FDG positive thyroid incidentalomas, as recommended by some studies, is unwarranted and further research to determine optimal management is needed. There was no clinically useful SUVmax cut-off value to determine malignancy and PET/CT may not be a useful imaging modality to follow these patients conservatively.

  4. Analysis of Metabolism of 6FDG: A PET Glucose Transport Tracer

    PubMed Central

    Muzic, Raymond F.; Chandramouli, Visvanathan; Huang, Hsuan-Ming; Wu, Chunying; Wang, Yanming; Ismail-Beigi, Faramarz

    2011-01-01

    Introduction We are developing 18F-labeled 6-fluoro-6-deoxy-D-glucose ([18F]6FDG) as a tracer of glucose transport. As part of this process it is important to characterize and quantify putative metabolites. In contrast to the ubiquitous PET tracer 18F-labeled 2-fluoro-2-deoxy-D-glucose ([18F]2FDG) which is phosphorylated and trapped intracellularly, the substitution of fluorine for a hydroxyl group at carbon 6 in [18F]6FDG should prevent its phosphorylation. Consequently, [18F]6FDG has the potential to trace the transport step of glucose metabolism without the confounding effects of phosphorylation and subsequent steps of metabolism. Herein the focus is to determine whether, and the degree to which, [18F]6FDG remains unchanged following intravenous injection. Methods Biodistribution studies were performed using 6FDG labeled with 18F as well as the longer-lived radionuclides 3H and 14C. Tissues were harvested at 1, 6, and 24 h following intravenous administration and radioactivity was extracted from the tissues and analyzed using a combination of ion exchange columns, high-performance liquid chromatography, and chemical reactivity. Results At the 1 h time-point, the vast majority of radioactivity in the liver, brain, heart, skeletal muscle, and blood was identified as 6FDG. At the 6- and 24-h time-points there was evidence of a minor amount of radioactive materials that appeared to be 6-fluoro-6-deoxy-D-sorbitol and possibly 6-fluoro-6-deoxy-D-gluconic acid. Conclusion On the time scale typical of PET imaging studies radioactive metabolites of [18F]6FDG are negligible. PMID:21718942

  5. Combination of FDG PET/CT and contrast-enhanced MSCT in detecting lymph node metastasis of esophageal cancer.

    PubMed

    Tan, Ru; Yao, Shu-Zhan; Huang, Zhao-Qin; Li, Jun; Li, Xin; Tan, Hai-Hua; Liu, Qing-Wei

    2014-01-01

    Lymph node metastasis is believed to be a dependent negative prognostic factor of esophageal cancer. To explore detection methods with high sensitivity and accuracy for metastases to regional and distant lymph nodes in the clinic is of great significance. This study focused on clinical application of FDG PET/CT and contrast-enhanced multiple-slice helical computed tomography (MSCT) in lymph node staging of esophageal cancer. One hundred and fifteen cases were examined with enhanced 64-slice-MSCT scan, and FDG PET/CT imaging was conducted for neck, chest and upper abdomen within one week. The primary lesion, location and numbers of metastatic lymph nodes were observed. Surgery was performed within one week after FDG PET/CT detection. All resected lesions were confirmed histopathologically as the gold standard. Comparative analysis of the sensitivity, specificity, and accuracy based on FDG PET/CT and MSCT was conducted. There were 946 lymph node groups resected during surgery from 115 patients, and 221 were confirmed to have metastasis pathologically. The sensitivity, specificity, accuracy of FDG PET/CT in detecting lymph node metastasis were 74.7%, 97.2% and 92.0%, while with MSCT they were 64.7%, 96.4%, and 89.0%, respectively. A significance difference was observed in sensitivity (p=0.030), but not the others (p>0.05). The accuracy of FDG PET/CT in detecting regional lymph node with or without metastasis were 91.9%, as compared to 89.4% for MSCT, while FDG PET/CT and MSCT values for detecting distant lymph node with or without metastasis were 94.4% and 94.7%. No significant difference was observed for either regional or distant lymph node metastasis. Additionally, for detecting para-esophageal lymph nodes metastasis, the sensitivity of FDG PET/CT was 72%, compared with 54.7% for MSCT (p=0.029). FDG PET/CT is more sensitive than MSCT in detecting lymph node metastasis, especially for para-esophageal lymph nodes in esophageal cancer cases, although no significant

  6. (18)F-FDG PET/CT Optimizes Treatment in Staphylococcus Aureus Bacteremia and Is Associated with Reduced Mortality.

    PubMed

    Berrevoets, Marvin A H; Kouijzer, Ilse J E; Aarntzen, Erik H J G; Janssen, Marcel J R; De Geus-Oei, Lioe-Fee; Wertheim, Heiman F L; Kullberg, Bart-Jan; Oever, Jaap Ten; Oyen, Wim J G; Bleeker-Rovers, Chantal P

    2017-09-01

    Metastatic infection is an important complication of Staphylococcus aureus bacteremia (SAB). Early diagnosis of metastatic infection is crucial, because specific treatment is required. However, metastatic infection can be asymptomatic and difficult to detect. In this study, we investigated the role of (18)F-FDG PET/CT in patients with SAB for detection of metastatic infection and its consequences for treatment and outcome. Methods: All patients with SAB at Radboud University Medical Center were included between January 2013 and April 2016. Clinical data and results of (18)F-FDG PET/CT and other imaging techniques, including echocardiography, were collected. Primary outcomes were newly diagnosed metastatic infection by (18)F-FDG PET/CT, subsequent treatment modifications, and patient outcome. Results: A total of 184 patients were included, and (18)F-FDG PET/CT was performed in 105 patients, of whom 99 had a high-risk bacteremia. (18)F-FDG PET/CT detected metastatic infectious foci in 73.7% of these high-risk patients. In 71.2% of patients with metastatic infection, no signs and symptoms suggesting metastatic complications were present before (18)F-FDG PET/CT was performed. (18)F-FDG PET/CT led to a total of 104 treatment modifications in 74 patients. Three-month mortality was higher in high-risk bacteremia patients without (18)F-FDG PET/CT performed than in those in whom (18)F-FDG PET/CT was performed (32.7% vs. 12.4%, P = 0.003). In multivariate analysis, (18)F-FDG PET/CT was the only factor independently associated with reduced mortality (P = 0.005; odds ratio, 0.204; 95% confidence interval, 0.066-0.624). A higher comorbidity score was independently associated with increased mortality (P = 0.003; odds ratio, 1.254; 95% confidence interval, 1.078-1.457). Conclusion:(18)F-FDG PET/CT is a valuable technique for early detection of metastatic infectious foci, often leading to treatment modification. Performing (18)F-FDG PET/CT is associated with significantly reduced

  7. Corticosteroid Responsive Sarcoidosis with Multisystemic Involvement Years after Initial Diagnosis: A Lymphoma Mimicker on 18-FDG PET/CT

    PubMed Central

    Acar, Turker; Savas, Recep; Kocacelebi, Kenan; Ucan, Eyup Sabri

    2015-01-01

    Sarcoidosis is a chronic multisystemic inflammatory disease characterized by noncaseating epithelioid cell granulomas. 18-Fluorodeoxyglucose positron-emission tomography/computer tomography (FDG-PET/CT) is increasingly used in routine clinical practice to assess active sarcoidosis because it can detect active inflammatory granulomatous disease. However, active sarcoidosis lesions are observed to be hypermetabolic on FDG-PET/CT much like malignancies, which may lead to misinterpretation on imaging. In this case report, we present a rare case of sarcoidosis with multisystem involvement including lung, lymph nodes, bone, pleura, and soft tissue that mimicked lymphoma on FDG-PET/CT and responded to corticosteroid treatment. PMID:26312138

  8. Atypical mycobacteriosis caused by Mycobacterium haemophilum in an immunocompromised patient: diagnosis by (18)F-FDG PET/CT.

    PubMed

    Münster, Silvia; Zustin, Jozef; Derlin, Thorsten

    2013-04-01

    We report a rare case of atypical mycobacteriosis diagnosed by F-FDG PET/CT. A 28-year-old man with a history of kidney transplantation presented with fever, painful nodular skin lesions, and elevated inflammatory markers. FDG PET/CT demonstrated multiple subcutaneous, cutaneous, and osseous areas of increased tracer uptake. Histopathologic and microbiological evaluation revealed disseminated infection with Mycobacterium haemophilum. FDG PET/CT is a valuable tool for early and correct diagnosis of occult sources of infection in immunocompromised patients.

  9. Lymphoma and tuberculosis: temporal evolution of dual pathology on sequential 18F-FDG PET/CT.

    PubMed

    Mukherjee, Anirban; Sharma, Punit; Karunanithi, Sellam; Dhull, Varun Singh; Kumar, Rakesh

    2014-08-01

    Tuberculosis can often be seen in patients undergoing chemotherapy for lymphoma, especially in endemic countries. As both tuberculosis and lymphoma can lead to hypermetabolic lesions of F-FDG PET/CT, a diagnostic dilemma often ensues. We present the sequential F-FDG PET/CT images of a 22-year-old female patient with Hodgkin lymphoma who developed tuberculosis and later relapse of lymphoma. These images present the temporal evaluation of the dual pathology on F-FDG PET/CT.

  10. Basic performance evaluation of a Si-PM array-based LGSO phoswich DOI block detector for a high-resolution small animal PET system.

    PubMed

    Yamamoto, Seiichi

    2013-07-01

    The silicon photomultiplier (Si-PM) is a promising photodetector for PET. However, it remains unclear whether Si-PM can be used for a depth-of-interaction (DOI) detector based on the decay time differences of the scintillator where pulse shape analysis is used. For clarification, we tested the Hamamatsu 4 × 4 Si-PM array (S11065-025P) combined with scintillators that used different decay times to develop DOI block detectors using the pulse shape analysis. First, Ce-doped Gd(2)SiO(5) (GSO) scintillators of 0.5 mol% Ce were arranged in a 4 × 4 matrix and were optically coupled to the center of each pixel of the Si-PM array for measurement of the energy resolution as well as its gain variations according to the temperature. Then two types of Ce-doped Lu(1.9)Gd(0.1)Si0(5) (LGSO) scintillators, 0.025 mol% Ce (decay time: ~31 ns) and 0.75 mol% Ce (decay time: ~46 ns), were optically coupled in the DOI direction, arranged in a 11 × 7 matrix, and optically coupled to a Si-PM array for testing of the possibility of a high-resolution DOI detector. The energy resolution of the Si-PM array-based GSO block detector was 18 ± 4.4 % FWHM for a Cs-137 gamma source (662 keV). Less than 1 mm crystals were clearly resolved in the position map of the LGSO DOI block detector. The peak-to-valley ratio (P/V) derived from the pulse shape spectra of the LGSO DOI block detector was 2.2. These results confirmed that Si-PM array-based DOI block detectors are promising for high-resolution small animal PET systems.

  11. (18)F-FDG PET radiomics approaches: comparing and clustering features in cervical cancer.

    PubMed

    Tsujikawa, Tetsuya; Rahman, Tasmiah; Yamamoto, Makoto; Yamada, Shizuka; Tsuyoshi, Hideaki; Kiyono, Yasushi; Kimura, Hirohiko; Yoshida, Yoshio; Okazawa, Hidehiko

    2017-08-16

    The aims of our study were to find the textural features on (18)F-FDG PET/CT which reflect the different histological architectures between cervical cancer subtypes and to make a visual assessment of the association between (18)F-FDG PET textural features in cervical cancer. Eighty-three cervical cancer patients [62 squamous cell carcinomas (SCCs) and 21 non-SCCs (NSCCs)] who had undergone pretreatment (18)F-FDG PET/CT were enrolled. A texture analysis was performed on PET/CT images, from which 18 PET radiomics features were extracted including first-order features such as standardized uptake value (SUV), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), second- and high-order textural features using SUV histogram, normalized gray-level co-occurrence matrix (NGLCM), and neighborhood gray-tone difference matrix, respectively. These features were compared between SCC and NSCC using a Bonferroni adjusted P value threshold of 0.0028 (0.05/18). To assess the association between PET features, a heat map analysis with hierarchical clustering, one of the radiomics approaches, was performed. Among 18 PET features, correlation, a second-order textural feature derived from NGLCM, was a stable parameter and it was the only feature which showed a robust trend toward significant difference between SCC and NSCC. Cervical SCC showed a higher correlation (0.70 ± 0.07) than NSCC (0.64 ± 0.07, P = 0.0030). The other PET features did not show any significant differences between SCC and NSCC. A higher correlation in SCC might reflect higher structural integrity and stronger spatial/linear relationship of cancer cells compared with NSCC. A heat map with a PET feature dendrogram clearly showed 5 distinct clusters, where correlation belonged to a cluster including MTV and TLG. However, the association between correlation and MTV/TLG was not strong. Correlation was a relatively independent PET feature in cervical cancer. (18)F-FDG PET textural features might reflect

  12. Oncologic 18F-FDG PET/CT: referring physicians' point of view.

    PubMed

    Karantanis, Dimitrios; Kalkanis, Dimitrios; Allen-Auerbach, Martin; Bogsrud, Trond Velde; Subramaniam, Rathan M; Danielson, Adam; Lowe, Val J; Czernin, Johannes

    2012-10-01

    Oncologic (18)F-FDG PET/CT is rapidly gaining acceptance in clinical practice. However, the referring physician's attitude toward the usefulness of this diagnostic modality is unknown. This survey was undertaken to collect information regarding the current perspective of referring physicians on oncologic PET/CT. We conducted a prospective worldwide, Web-based survey of physicians who manage cancer patients. A total of 963 referring physicians completed a 20-question survey focused on their experience with oncologic (18)F-FDG PET/CT. Attention was directed toward their confidence about indications, their satisfaction with related educational resources, the quality of interaction with interpreting physicians, and practical problems encountered. The respondents included oncologists (38.5%, n = 371), hematologists (16.4%, n = 158), radiation oncologists (9.0%, n = 87), surgeons (30.3%, n = 292), and other physicians (5.7%, n = 55). Only 25.2% of respondents considered the oncologic (18)F-FDG PET/CT indications to be well established and defined. Frequent uncertainty about the need for a PET scan was indicated by 62.3% of the respondents. High cost and overinterpretation of findings were the most commonly reported concerns (47.0% and 40.9%, respectively). The experience and skill level of the interpreting physician was considered very important by 96.8% of the surveyed physicians. Referring physicians expressed considerable uncertainty about the appropriate use of oncologic PET/CT. Additional major concerns are procedure costs and quality of interpretation. The responses suggest a strong need for efforts to educate referring and interpreting physicians about the appropriate use of (18)F-FDG PET/CT in oncology.

  13. (18)F-FDG PET/CT in the detection of asymptomatic malignant melanoma recurrence.

    PubMed

    Lawal, Ismaheel; Lengana, Thabo; Ololade, Kehinde; Boshomane, Tebatso; Reyneke, Florette; Modiselle, Moshe; Vorster, Mariza; Sathekge, Mike

    2017-06-12

    To evaluate the diagnostic accuracy of FDG PET/CT in the detection of asymptomatic recurrence in patients with malignant melanoma who have had resection of their primary lesion. We also aimed to determine the pattern and factors predisposing to disease recurrence. Patients with malignant melanoma who have had surgical resection of their disease and without any clinical evidence of disease recurrence were followed-up with FDG PET/CT. The diagnostic accuracy of FDG PET/CT, pattern of recurrence and factors predictive of disease recurrence were determined. A total of 144 patients were followed-up for a median period of 50.50 months. Asymptomatic recurrence was seen in 37 patients (25.7 %) with a median time to recurrence of 20 months. Lymph node was the commonest site of asymptomatic recurrence. Sex, tumour depth, histology type and presence of nodal metastasis were significant predictors of tumour recurrence. Age, race, site of primary lesion, type of lymph node resection were not significant predictors of disease recurrence. Race has a significant effect on the histological subtype of tumour (nodular maligna was more common in Caucasian while acral lentiginous was more prevalent in the Blacks) and the site of the primary lesion (lower limb in Blacks and trunk in Caucasians). Sensitivity, specificity and accuracy of FDG PET/CT for the detection of disease recurrence were 94.5 %, 87.6 % and 89.6 % respectively. FDG PET/CT is a suitable modality for early detection of asymptomatic recurrence of malignant melanoma. Asymptomatic recurrence most commonly occurs in lymph nodes. Sex, nodal metastasis and tumour pathologic features are predictors of recurrence.

  14. FDG PET/CT in infection and inflammation--current and emerging clinical applications.

    PubMed

    Vaidyanathan, S; Patel, C N; Scarsbrook, A F; Chowdhury, F U

    2015-07-01

    Integrated positron emission tomography/computed tomography (PET/CT) with the glucose analogue, 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG), is an evolving hybrid imaging technique in the evaluation of an important and diverse group of pathological conditions, which are characterised by infection and aseptic inflammation. With a rapidly expanding body of evidence, it is being increasingly recognised that, in addition to its established role in oncological imaging, FDG PET/CT also has clinical utility in suspected infection and inflammation. The technique can identify the source of infection or inflammation in a timely fashion ahead of morphological changes on conventional anatomical imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), map the extent and severity of disease, identify sites for tissue sampling, and assess therapy response. FDG PET/CT exhibits distinct advantages over traditional radionuclide imaging techniques in terms of shorter duration of examination, higher spatial resolution, non-invasive nature of acquisition, ability to perform quantitative analyses, and the provision of a synergistic combination of functional and anatomical imaging. With the use of illustrative clinico-radiological cases, this article discusses the current and emerging evidence for the use of FDG PET/CT in a broad spectrum of disorders, such as fever of unknown origin, sarcoidosis, large vessel vasculitis, musculoskeletal infections, joint prosthesis or implant-related complications, human immunodeficiency virus (HIV)-related infections, and miscellaneous indications, such as IgG4-related systemic disease. It will also briefly summarise the role of more novel tracers such as FDG-labelled leukocytes and gallium-68 PET tracers in this arena. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  15. (18)F-FDG PET/CT in the clinical management of patients with lymphoma.

    PubMed

    Tamayo, P; Martín, A; Díaz, L; Cabrero, M; García, R; García-Talavera, P; Caballero, D

    The aim of this work was to review the current recommendations for staging and response assessment of patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) in routine clinical practice after chemotherapy and/or stem cell transplantation. A five-point scale (5-PS) from the First International Workshop on PET in Lymphoma in Deauville, France, in 2009, was recommended as the standard tool to score imaging to assess treatment response in patients with lymphoma using (18)F-Fluorodeoxyglucose (FDG) PET/CT. Following the recommendations of the 11th and 12th International Conferences on Malignant Lymphoma held in Lugano (Switzerland), in 2011 and 2013, respectively, a consensus (the so-called Lugano Classification) was reached regarding the use of PET/CT for staging and response assessment in FDG-avid lymphomas. As a result, (18)F-FDG PET/CT was formally incorporated into standard staging for FDG-avid lymphomas. A bone marrow biopsy is no longer indicated for the routine staging of HL and most diffuse large B-cell lymphomas. PET/CT will be used to assess response in FDG-avid histologies using the 5-point scale. The recent introduction of biological agents with immune mechanisms requires flexibility in interpretations of the Lugano criteria due to tumour flare or a pseudo-progression effect produced by these agents. Provisional criteria have been proposed (Lymphoma Response to Immunomodulatory Therapy Criteria) with the introduction of the term 'Indeterminate Response' in order to identify this phenomenon until confirmed as flare/pseudoprogression or true progression. All these recommendations will improve evaluations of patients with lymphoma, and allow comparison of results from clinical practice and trials. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  16. (18) F-FDG-PET/CT as adjunctive diagnostic modalities in canine fever of unknown origin.

    PubMed

    Grobman, Megan; Cohn, Leah; Knapp, Stephanie; Bryan, Jeffrey N; Reinero, Carol

    2017-09-18

    Fever of unknown origin (FUO) is a persistent or recurrent fever for which the underlying source has not been identified despite diagnostic investigation. In people, (18) F-fluoro-2-deoxyglucose positron emission tomography ((18) F-FDG-PET) alone or in combination with computed tomography (CT) is often beneficial in detecting the source of fever when other diagnostics have failed. Veterinary reports describing use of these modalities in animals with fever of unknown origin are currently lacking. Aims of this retrospective case series were to describe (18) F-FDG-PET or (18) F-FDG-PET/CT findings in a group of dogs with fever of unknown origin. Dogs presenting to a single center between April 2012 and August 2015 were included. A total of four dogs met inclusion criteria and underwent either positron emission tomography (n = 2) or positron emission tomography/CT (n = 2) as a part of their diagnostic investigation. All subjects underwent extensive diagnostic testing prior to (18) F-FDG-PET/CT. Initial diagnostic evaluation failed to identify either a cause of fever or an anatomic location of disease in these four dogs. In each dog, positron emission tomography or positron emission tomography/CT was either able to localize or rule out the presence of focal lesion thereby allowing for directed sampling and/or informed disease treatment. Follow up (18) F-FDG-PET/CT scans performed in two patients showed improvement of observed abnormalities (n = 1) or detected recurrence of disease allowing for repeated treatment before clinical signs recurred (n = 1). Fever resolved after specific treatment in each dog. Findings from the current study supported the use of positron emission tomography or positron emission tomography/CT as adjunctive imaging modalities for diagnosis and gauging response to therapy in dogs with fever of unknown origin. © 2017 American College of Veterinary Radiology.

  17. (18)F-FDG PET/CT and contrast-enhanced CT findings of pulmonary cryptococcosis.

    PubMed

    Wang, Si-Yun; Chen, Gang; Luo, Dong-Lan; Shao, Dan; Liu, En-Tao; Sun, Taotao; Wang, Shu-Xia

    2017-04-01

    Pulmonary cryptococcosis is an uncommon cause of pulmonary nodules in non-AIDS patients. This study reports the (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG PET/CT) and contrast-enhanced CT (CE-CT) findings of 42 patients with pulmonary cryptococcosis. A retrospective review of the (18)F-FDG PET/CT and CE-CT findings of 42 patients with histologically proven pulmonary cryptococcosis was conducted. All patients underwent PET/CT and CE-CT in the same session. The CT diagnosis was based on the location, morphological features, and enhancement of lesions. The PET/CT findings were recorded, and clinical data and surgical and histopathological findings were collected. The results of the PET scans revealed that 37 (88%) of 42 patients showed higher FDG uptake, and 5 (12%) patients demonstrated lower FDG uptake than the mediastinal blood pool. The maximum standardized uptake value (SUV) of pulmonary cryptococcosis ranged from 1.4 to 13.0 (average: 5.7±3.3, median 4.9). A single nodular pattern was the most prevalent pattern observed and was found in 29 (69%) patients. This pattern was followed by scattered nodular (n=4, 10%), clustered nodular (n=3, 7%), mass-like (n=3, 7%), and bronchopneumonic (n=3, 7%) patterns. The most frequent pattern of immunocompetent patients was the single nodular pattern (29 of 33, 88%). Immunocompromised patients most frequently pattern exhibited mass-like (3 of 9, 33%) and bronchopneumonic (3 of 9, 33%) patterns. Pulmonary cryptococcosis most commonly appears as single nodules in immunocompetent patients. Mass-like and bronchopneumonic patterns were common in immunocompromised patients. In 88% of patients, lung lesions showed high FDG uptake, thus mimicking a possible malignant condition. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Prognostic value of interim FDG-PET in Hodgkin lymphoma: systematic review and meta-analysis.

    PubMed

    Adams, Hugo J A; Nievelstein, Rutger A J; Kwee, Thomas C

    2015-08-01

    This study aimed to systematically review and meta-analyse the value of interim (18) F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in predicting treatment failure in Hodgkin lymphoma. MEDLINE was systematically searched for original studies that used standardized international criteria for interim FDG-PET interpretation. Included studies were methodologically assessed. Summary receiver operating characteristic (sROC) analysis was performed, and pooled sensitivity and specificity were calculated using a random effects model. Heterogeneity in diagnostic odds ratios (DORs) across studies was assessed and potential sources for inter-study heterogeneity were explored using subgroup analyses. Ten studies, comprising a total of 1389 Hodgkin lymphoma patients, were included. Sensitivity, specificity, positive predictive value and negative predictive value of interim FDG-PET for predicting treatment failure ranged between 0.0-81.5%, 72.2-96.6%, 0.0-86.0% and 84.4-98.6%, respectively. The area under the sROC curve was 0.877. Pooled sensitivity and specificity were 70.8% [95% confidence interval (CI): 64.7-76.4%] and 89.9% (95% CI: 88.0-91.6%). There was heterogeneity in DORs across individual studies (I2 = 72.7). The overall prognostic value of interim FDG-PET appears to be moderate for excluding and relatively high for identifying treatment failure in Hodgkin lymphoma. However, interim FDG-PET cannot yet be implemented in routine clinical practice due to moderate-quality evidence and inter-study heterogeneity that cannot be fully explained yet.

  19. 18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

    PubMed Central

    Mhlanga, Joyce C.; Carrino, John A.; Lodge, Martin; Wang, Hao

    2015-01-01

    Purpose The aim of this study was to prospectively determine the feasibility and compare the novel use of a positron emission mammography (PEM) scanner with standard PET/CT for evaluating hand osteoarthritis (OA) with 18F-FDG. Methods Institutional review board approval and written informed consent were obtained for this HIPAA-compliant prospective study in which 14 adults referred for oncological 18F-FDG PET/CT underwent dedicated hand PET/CT followed by arthro-PET using the PEM device. Hand radiographs were obtained and scored for the presence and severity of OA. Summed qualitative and quantitative joint glycolytic scores for each modality were compared with the findings on plain radiography and clinical features. Results Eight patients with clinical and/or radiographic evidence of OA comprised the OA group (mean age 73±7.7 years). Six patients served as the control group (53.7±9.3 years). Arthro-PET quantitative and qualitative joint glycolytic scores were highly correlated with PET/CT findings in the OA patients (r=0.86. p =0.007; r=0.94, p=0.001). Qualitative arthro-PET and PET/CT joint scores were significantly higher in the OA patients than in controls (38.7±6.6 vs. 32.2±0.4, p=0.02; 37.5±5.4 vs. 32.2±0.4, p=0.03, respectively). Quantitative arthro-PET and PET/CT maximum SUV-lean joint scores were higher in the OA patients, although they did not reach statistical significance (20.8±4.2 vs. 18±1.8, p= 0.13; 22.8±5.38 vs. 20.1±1.54, p=0.21). By definition, OA patients had higher radiographic joint scores than controls (30.9±31.3 vs. 0, p=0.03). Conclusion Hand imaging using a small field of view PEM system (arthro-PET) with FDG is feasible, performing comparably to PET/CT in assessing metabolic joint activity. Arthro-PET and PET/CT showed higher joint FDG uptake in OA. Further exploration of arthro-PET in arthritis management is warranted. PMID:25134669

  20. 18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters.

    PubMed

    Mhlanga, Joyce C; Carrino, John A; Lodge, Martin; Wang, Hao; Wahl, Richard L

    2014-12-01

    The aim of this study was to prospectively determine the feasibility and compare the novel use of a positron emission mammography (PEM) scanner with standard PET/CT for evaluating hand osteoarthritis (OA) with (18)F-FDG. Institutional review board approval and written informed consent were obtained for this HIPAA-compliant prospective study in which 14 adults referred for oncological (18)F-FDG PET/CT underwent dedicated hand PET/CT followed by arthro-PET using the PEM device. Hand radiographs were obtained and scored for the presence and severity of OA. Summed qualitative and quantitative joint glycolytic scores for each modality were compared with the findings on plain radiography and clinical features. Eight patients with clinical and/or radiographic evidence of OA comprised the OA group (mean age 73 ± 7.7 years). Six patients served as the control group (53.7 ± 9.3 years). Arthro-PET quantitative and qualitative joint glycolytic scores were highly correlated with PET/CT findings in the OA patients (r = 0.86. p = 0.007; r = 0.94, p = 0.001). Qualitative arthro-PET and PET/CT joint scores were significantly higher in the OA patients than in controls (38.7 ± 6.6 vs. 32.2 ± 0.4, p = 0.02; 37.5 ± 5.4 vs. 32.2 ± 0.4, p = 0.03, respectively). Quantitative arthro-PET and PET/CT maximum SUV-lean joint scores were higher in the OA patients, although they did not reach statistical significance (20.8 ± 4.2 vs. 18 ± 1.8, p = 0.13; 22.8 ± 5.38 vs. 20.1 ± 1.54, p = 0.21). By definition, OA patients had higher radiographic joint scores than controls (30.9 ± 31.3 vs. 0, p = 0.03). Hand imaging using a small field of view PEM system (arthro-PET) with FDG is feasible, performing comparably to PET/CT in assessing metabolic joint activity. Arthro-PET and PET/CT showed higher joint FDG uptake in OA. Further exploration of arthro-PET in arthritis management is warranted.

  1. The role of 18F-FDG PET or PET/CT in the detection of fever of unknown origin.

    PubMed

    Qiu, Lin; Chen, Yue

    2012-11-01

    Even with the recent advance in diagnostic tools and techniques, fever of unknown origin (FUO) remains a clinical challenge. A wide range of diseases, mainly infections, autoimmune conditions (inflammatory diseases), malignancies and miscellaneous can cause FUO. Positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) scanning makes a great contribution to the diagnosis and differential diagnosis of FUO due to the high sensitivity of pathological accumulation of 18F-FDG. The diagnostic yield of PET/CT is higher than traditional radiographic imaging and other nuclear medicine scanning. Owing to the numerous advantages of PET/CT including high sensitivity and the ability to perform whole-body scans, many rare diseases presenting with FUO can be detected and the spectrum of diseases that can exhibit FUO has been increasing. Recent studies utilizing FUO are discussed in this paper. However, there are limited data available about the role of 18F-FDG PET or PET/CT in evaluation of FUO. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. Determinants of diagnostic performance of 18F-FDG PET/CT in patients with fever of unknown origin.

    PubMed

    Pereira, Ashoka M V; Husmann, Lars; Sah, Bert-Ram; Battegay, Edouard; Franzen, Daniel

    2016-01-01

    There is uncertainty about patient selection and the adequate timing at which fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) is indicated in the diagnostic work-up of fever of unknown origin (FUO). The aim of this study was to determine the diagnostic performance of F-FDG PET/CT in patients with FUO. All consecutive patients who underwent F-FDG PET/CT at the University Hospital Zurich because of FUO between 2006 and 2012 were included in this retrospective, observational study. A total of 76 patients [70% men, median (interquartile range) age 60 (47-67) years] were included. F-FDG PET/CT showed characteristically increased F-FDG activity in 56 patients (74%), leading to confirmation of or change in the suspected cause of FUO in 57 and 17%, respectively. The final diagnosis after F-FDG PET/CT included infection (21%), malignancy (22%), noninfectious inflammatory disease (12%), others (5%), or an unknown cause (40%). The success rate, sensitivity, and specificity of F-FDG PET/CT were 60, 77, and 31%, respectively. Sensitivity was highest in patients with suspected malignancy (100%, 95% confidence interval 79-100%). Diagnostic performance was independent of the investigated variables other than suspected infection as a cause of FUO (odds ratio 0.1, 95% confidence interval 0.01-0.8, P=0.033). The diagnostic performance of F-FDG PET/CT was significantly higher in patients with suspected malignancy causing a FUO compared with suspected infection or noninfectious inflammatory disease. However, it was independent of the baseline characteristics and duration of fever. This supports the recommendation to perform F-FDG PET/CT early in the diagnostic work-up of FUO, which may shorten disease duration and lower health costs, particularly when infection or malignancy is suspected.

  3. Exploring Small Animal Care. Teacher's Guide.

    ERIC Educational Resources Information Center

    Livesey, Dennis W.

    This course guide in small animal care is designed to give students seeking employment in veterinary hospitals, kennels, or pet shops an opportunity to (1) develop basic skills in small animal handling, sanitation of housing, and nutrition, (2) acquire skills in dog and cat grooming, including shop operation, (3) develop attitudes which contribute…

  4. Exploring Small Animal Care. Teacher's Guide.

    ERIC Educational Resources Information Center

    Livesey, Dennis W.

    This course guide in small animal care is designed to give students seeking employment in veterinary hospitals, kennels, or pet shops an opportunity to (1) develop basic skills in small animal handling, sanitation of housing, and nutrition, (2) acquire skills in dog and cat grooming, including shop operation, (3) develop attitudes which contribute…

  5. Natural history of atherosclerotic disease progression as assessed by (18)F-FDG PET/CT.

    PubMed

    Hetterich, Holger; Rominger, Axel; Walter, Lisa; Habs, Maximilian; Volpers, Sarah; Hacker, Marcus; Reiser, Maximilian F; Bartenstein, Peter; Saam, Tobias

    2016-01-01

    The aim of this study was to assess the impact of cardiovascular risk factors and plaque inflammation on the progression of atherosclerosis as assessed by positron emission tomography/computed tomography (PET/CT) imaging with (18)F-radiolabled fluorodeoxyglucose ((18)F-FDG). This study was designed as a retrospective cohort study. Patients who received a (18)F-FDG PET/CT scan and follow-up scan 9-24 months later without systemic inflammation or steroid medication were eligible for the study. (18)F-FDG PET/CT included a full diagnostic contrast enhanced CT scan. Cardiovascular risk factors and medication were documented. Calcified plaque volume, lumen area and (18)F-FDG uptake, quantified by the target-to-background ratio (TBR), were measured in the carotid arteries, aorta and iliac arteries. Influence of cardiovascular risk factors and vessel wall inflammation on atherosclerotic disease progression was analyzed. Ninety-four patients underwent baseline and follow-up whole body (18)F-FDG PET/CT (mean follow-up time 14.5 ± 3.5 months). Annualized calcified plaque volume increased by 15.4 % (p < 0.0001), carotid and aortic lumen area decreased by 10.5 % (p < 0.0001) and 1.7 % (p = 0.045). There was no significant difference in (18)F-FDG uptake at baseline and follow-up (mean TBR 1.44 ± 0.18 vs. 1.42 ± 0.19, p = 0.18). Multiple linear regression analysis identified hypertension as an independent predictor for total, aortic and iliac calcified plaque volume progression (all p < 0.04). Carotid lumen reduction was predicted by hypercholesterolemia (p = 0.008) while aortic lumen reduction was associated with BMI and mean (18)F-FDG uptake (p ≤ 0.005). Furthermore we observed a dose response relationship between the number of cardiovascular risk factors and calcified plaque volume progression in the aorta (p = 0.03). Findings from this study provide data on the natural history of atherosclerotic disease burden in multiple vascular beds and emphasize the value of

  6. High School Small Animal Laboratory--Business

    ERIC Educational Resources Information Center

    Penn, Alan

    1974-01-01

    An Ohio vocational school Small Animal Care program prepares students for entry level employment as veterinary assistants, pet shop salesmen, kennel workers, animal groomers, Humane Society workers, laboratory animal assistants, and riding stable assistants. (EA)

  7. High School Small Animal Laboratory--Business

    ERIC Educational Resources Information Center

    Penn, Alan

    1974-01-01

    An Ohio vocational school Small Animal Care program prepares students for entry level employment as veterinary assistants, pet shop salesmen, kennel workers, animal groomers, Humane Society workers, laboratory animal assistants, and riding stable assistants. (EA)

  8. Adaptive brachytherapy treatment planning for cervical cancer using FDG-PET

    SciTech Connect

    Lin, Lilie L.; Mutic, Sasa; Low, Daniel A.; La Forest, Richard; Vicic, Milos; Zoberi, Imran; Miller, Tom R.; Grigsby, Perry W. . E-mail: pgrigsby@wustl.edu

    2007-01-01

    Purpose: A dosimetric study was conducted to compare intracavitary brachytherapy using both a conventional and a custom loading intended to cover a positron emission tomography (PET)-defined tumor volume in patients with cervix cancer. Methods and Materials: Eleven patients who underwent an [{sup 18}F]-fluoro-deoxy-D-glucose (FDG)-PET in conjunction with their first, middle, or last brachytherapy treatment were included in this prospective study. A standard plan that delivers 6.5 Gy to point A under ideal conditions was compared with an optimized plan designed to conform the 6.5-Gy isodose surface to the PET defined volume. Results: A total of 31 intracavitary brachytherapy treatments in conjunction with an FDG-PET were performed. The percent coverage of the target isodose surface for the first implant with and without optimization was 73% and 68% (p = 0.21). The percent coverage of the target isodose surface for the mid/final implant was 83% and 70% (p = 0.02), respectively. The dose to point A was higher with the optimized plans for both the first implant (p = 0.02) and the mid/last implants (p = 0.008). The dose to 2 cm{sup 3} and 5 cm{sup 3} of both the bladder and rectum were not significantly different. Conclusions: FDG-PET based treatment planning allowed for improved dose coverage of the tumor without significantly increasing the dose to the bladder and rectum.

  9. Serial changes of (18)F-FDG PET/CT findings in ischiopubic synchondrosis: comparison with contrast-enhanced MRI.

    PubMed

    Tsuji, Kazunobu; Tsuchida, Tatsuro; Kosaka, Nobuyuki; Tanizawa, Akihiko; Kimura, Hirohiko

    2015-01-01

    A 3 years old female patient underwent resection and chemotherapy for a yolk sac tumor of the retroperitoneum. Two years later, fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) showed high uptake in the right ischiopubic synchondrosis (IPS), which had a radiolucent structure on CT. The structure showed contrast enhancement on magnetic resonance imaging (MRI), which was a non-specific finding. Six weeks later, a follow-up (18)F-FDG PET/CT scan was performed which showed no abnormal uptake in the IPS. The disappearance of (18)F-FDG uptake preceded that of contrast enhancement on MRI, which was seen 7 months after the initial (18)F-FDG PET/CT scan. This is the first report showing serial changes of (18)F-FDG uptake in IPS, in comparison to MRI findings.

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  12. 18-FDG PET/CT assessment of basal cell carcinoma with vismodegib.

    PubMed

    Thacker, Curtis A; Weiss, Glen J; Tibes, Raoul; Blaydorn, Lisa; Downhour, Molly; White, Erica; Baldwin, Jason; Hoff, Daniel D; Korn, Ronald L

    2012-10-01

    The use of 18-fluorodeoxyglucose (FDG) positron emission tomography with computed tomography (PET/CT) in subjects with advanced basal cell carcinoma (BCC) has not been fully explored due to the rarity of disease presentation. This study evaluated PET/CTs from subjects with advanced BCC participating in a phase I dose-escalation clinical trial of vismodegib. Fourteen subjects with BCC were imaged with 18-FDG PET/CT for lesion identification and response categorizing (European Organisation for Research and Treatment for Cancer [EORTC] and PET response criteria in solid tumors [PERCIST] 1.0). Several parameters including metabolic activity of target lesions, site of disease presentation and spread, treatment response, and prognostic significance of metabolic activity following therapy were evaluated. All subjects exhibited at least one hypermetabolic lesion. Most subjects had only four organ systems involved at study enrollment: skin-muscle (93%), lung (57%), lymph nodes (29%), and bone (21%). SUVmax measured across all lesions decreased (median 33%, SD ± 45%) following therapy with metabolic activity normalizing or disappearing in 42% of lesions. No significant difference was observed between EORTC and PERCIST 1.0. Subjects that demonstrated at least a 33% reduction in SUVmax from baseline had a significantly longer progression-free survival (PFS) (median 17 months, 95% confidence interval [CI] ±4 months vs. 9 months, 95% CI ±5 months, P = 0.038) and overall survival (OS) (median 24 months, 95% CI ±4 months vs. 17 months, 95% CI ±13 months, P = 0.019). BCC lesions are hypermetabolic on 18-FDG PET/CT. A decrease in SUVmax was associated with improved PFS and OS. These results further support the incorporation of 18-FDG PET/CT scans in advanced BCC management.

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

    PubMed

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

    2014-01-09

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

  14. (18)F-FDG-labeled red blood cell PET for blood-pool imaging: preclinical evaluation in rats.

    PubMed

    Matsusaka, Yohji; Nakahara, Tadaki; Takahashi, Kazuhiro; Iwabuchi, Yu; Nishime, Chiyoko; Kajimura, Mayumi; Jinzaki, Masahiro

    2017-12-01

    Red blood cells (RBCs) labeled with single-photon emitters have been clinically used for blood-pool imaging. Although some PET tracers have been introduced for blood-pool imaging, they have not yet been widely used. The present study investigated the feasibility of labeling RBCs with (18)F-2-deoxy-2-fluoro-D-glucose ((18)F-FDG) for blood-pool imaging with PET. RBCs isolated from venous blood of rats were washed with glucose-free phosphate-buffered saline and labeled with (18)F-FDG. To optimize labeling efficiency, the effects of glucose deprivation time and incubation (labeling) time with (18)F-FDG were investigated. Post-labeling stability was assessed by calculating the release fraction of radioactivity and identifying the chemical forms of (18)F in the released and intracellular components of (18)F-FDG-labeled RBCs incubated in plasma. Just after intravenous injection of the optimized autologous (18)F-FDG-labeled RBCs, dynamic PET scans were performed to evaluate in vivo imaging in normal rats and intraabdominal bleeding models (temporary and persistent bleeding). The optimal durations of glucose deprivation and incubation (labeling) with (18)F-FDG were 60 and 30 min, respectively. As low as 10% of (18)F was released as the form of (18)F-FDG from (18)F-FDG-labeled RBCs after a 60-min incubation. Dynamic PET images of normal rats showed strong persistence in the cardiovascular system for at least 120 min. In the intraabdominal bleeding models, (18)F-FDG-labeled RBC PET visualized the extravascular blood clearly and revealed the dynamic changes of the extravascular radioactivity in the temporary and persistent bleeding. RBCs can be effectively labeled with (18)F-FDG and used for blood-pool imaging with PET in rats.

  15. A Survey of FDG- and Amyloid-PET Imaging in Dementia and GRADE Analysis

    PubMed Central

    Daniela, Perani; Orazio, Schillaci; Alessandro, Padovani; Mariano, Nobili Flavio; Leonardo, Iaccarino; Pasquale Anthony, Della Rosa; Giovanni, Frisoni; Carlo, Caltagirone

    2014-01-01

    PET based tools can improve the early diagnosis of Alzheimer's disease (AD) and differential diagnosis of dementia. The importance of identifying individuals at risk of developing dementia among people with subjective cognitive complaints or mild cognitive impairment has clinical, social, and therapeutic implications. Within the two major classes of AD biomarkers currently identified, that is, markers of pathology and neurodegeneration, amyloid- and FDG-PET imaging represent decisive tools for their measurement. As a consequence, the PET tools have been recognized to be of crucial value in the recent guidelines for the early diagnosis of AD and other dementia conditions. The references based recommendations, however, include large PET imaging literature based on visual methods that greatly reduces sensitivity and specificity and lacks a clear cut-off between normal and pathological findings. PET imaging can be assessed using parametric or voxel-wise analyses by comparing the subject's scan with a normative data set, significantly increasing the diagnostic accuracy. This paper is a survey of the relevant literature on FDG and amyloid-PET imaging aimed at providing the value of quantification for the early and differential diagnosis of AD. This allowed a meta-analysis and GRADE analysis revealing high values for PET imaging that might be useful in considering recommendations. PMID:24772437

  16. A survey of FDG- and amyloid-PET imaging in dementia and GRADE analysis.

    PubMed

    Perani, Daniela; Daniela, Perani; Schillaci, Orazio; Orazio, Schillaci; Padovani, Alessandro; Alessandro, Padovani; Nobili, Flavio Mariano; Mariano, Nobili Flavio; Iaccarino, Leonardo; Leonardo, Iaccarino; Della Rosa, Pasquale Anthony; Pasquale Anthony, Della Rosa; Frisoni, Giovanni; Giovanni, Frisoni; Caltagirone, Carlo; Carlo, Caltagirone

    2014-01-01

    PET based tools can improve the early diagnosis of Alzheimer's disease (AD) and differential diagnosis of dementia. The importance of identifying individuals at risk of developing dementia among people with subjective cognitive complaints or mild cognitive impairment has clinical, social, and therapeutic implications. Within the two major classes of AD biomarkers currently identified, that is, markers of pathology and neurodegeneration, amyloid- and FDG-PET imaging represent decisive tools for their measurement. As a consequence, the PET tools have been recognized to be of crucial value in the recent guidelines for the early diagnosis of AD and other dementia conditions. The references based recommendations, however, include large PET imaging literature based on visual methods that greatly reduces sensitivity and specificity and lacks a clear cut-off between normal and pathological findings. PET imaging can be assessed using parametric or voxel-wise analyses by comparing the subject's scan with a normative data set, significantly increasing the diagnostic accuracy. This paper is a survey of the relevant literature on FDG and amyloid-PET imaging aimed at providing the value of quantification for the early and differential diagnosis of AD. This allowed a meta-analysis and GRADE analysis revealing high values for PET imaging that might be useful in considering recommendations.

  17. (18)F-FDG PET image biomarkers improve prediction of late radiation-induced xerostomia.

    PubMed

    van Dijk, Lisanne V; Noordzij, Walter; Brouwer, Charlotte L; Boellaard, Ronald; Burgerhof, Johannes G M; Langendijk, Johannes A; Sijtsema, Nanna M; Steenbakkers, Roel J H M

    2017-09-23

    Current prediction of radiation-induced xerostomia 12months after radiotherapy (Xer12m) is based on mean parotid gland dose and baseline xerostomia (Xerbaseline) scores. The hypothesis of this study was that prediction of Xer12m is improved with patient-specific characteristics extracted from (18)F-FDG PET images, quantified in PET image biomarkers (PET-IBMs). Intensity and textural PET-IBMs of the parotid gland were collected from pre-treatment (18)F-FDG PET images of 161 head and neck cancer patients. Patient-rated toxicity was prospectively collected. Multivariable logistic regression models resulting from step-wise forward selection and Lasso regularisation were internally validated by bootstrapping. The reference model with parotid gland dose and Xerbaseline was compared with the resulting PET-IBM models. High values of the intensity PET-IBM (90th percentile (P90)) and textural PET-IBM (Long Run High Grey-level Emphasis 3 (LRHG3E)) were significantly associated with lower risk of Xer12m. Both PET-IBMs significantly added in the prediction of Xer12m to the reference model. The AUC increased from 0.73 (0.65-0.81) (reference model) to 0.77 (0.70-0.84) (P90) and 0.77 (0.69-0.84) (LRHG3E). Prediction of Xer12m was significantly improved with pre-treatment PET-IBMs, indicating that high metabolic parotid gland activity is associated with lower risk of developing late xerostomia. This study highlights the potential of incorporating patient-specific PET-derived functional characteristics into NTCP model development. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  18. Early identification of MCI converting to AD: a FDG PET study.

    PubMed

    Pagani, Marco; Nobili, Flavio; Morbelli, Silvia; Arnaldi, Dario; Giuliani, Alessandro; Öberg, Johanna; Girtler, Nicola; Brugnolo, Andrea; Picco, Agnese; Bauckneht, Matteo; Piva, Roberta; Chincarini, Andrea; Sambuceti, Gianmario; Jonsson, Cathrine; De Carli, Fabrizio

    2017-06-29

    Mild cognitive impairment (MCI) is a transitional pathological stage between normal ageing (NA) and Alzheimer's disease (AD). Although subjects with MCI show a decline at different rates, some individuals remain stable or even show an improvement in their cognitive level after some years. We assessed the accuracy of FDG PET in discriminating MCI patients who converted to AD from those who did not. FDG PET was performed in 42 NA subjects, 27 MCI patients who had not converted to AD at 5 years (nc-MCI; mean follow-up time 7.5 ± 1.5 years), and 95 MCI patients who converted to AD within 5 years (MCI-AD; mean conversion time 1.8 ± 1.1 years). Relative FDG uptake values in 26 meta-volumes of interest were submitted to ANCOVA and support vector machine analyses to evaluate regional differences and discrimination accuracy. The MCI-AD group showed significantly lower FDG uptake values in the temporoparietal cortex than the other two groups. FDG uptake values in the nc-MCI group were similar to those in the NA group. Support vector machine analysis discriminated nc-MCI from MCI-AD patients with an accuracy of 89% (AUC 0.91), correctly detecting 93% of the nc-MCI patients. In MCI patients not converting to AD within a minimum follow-up time of 5 years and MCI patients converting within 5 years, baseline FDG PET and volume-based analysis identified those who converted with an accuracy of 89%. However, further analysis is needed in patients with amnestic MCI who convert to a dementia other than AD.

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

    PubMed Central

    Nakajima, Reiko; Abe, Koichiro; Sakai, Shuji

    2015-01-01

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

  20. FDG-PET imaging for the assessment of physiologic volume response during radiotherapy in cervix cancer

    SciTech Connect

    Lin, Lilie L.; Yang Zhiyun; Mutic, Sasa; Miller, Tom R.; Grigsby, Perry W. . E-mail: pgrigsby@wustl.edu

    2006-05-01

    Purpose: To evaluate the physiologic tumor volume response during treatment in cervical cancer using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). Patients and Methods: This was a prospective study of 32 patients. Physiologic tumor volume in cubic centimeters was determined from the FDG-PET images using the 40% threshold method. Results: The mean pretreatment tumor volume was 102 cm{sup 3}. The mean volume by clinical Stages I, II, and III were 54, 79, and 176 cm{sup 3}, respectively. After 19.8 Gy external irradiation to the pelvis, the reduction in tumor volume was 29% (72 cm{sup 3}). An additional 13 Gy from high-dose-rate (HDR) brachytherapy reduced the mean volume to 15.4 cm{sup 3}, and this was subsequently reduced to 8.6 cm{sup 3} with 13 Gy additional HDR brachytherapy (26 Gy, HDR). Four patients had physiologic FDG uptake in the cervix at 3 months after the completion of therapy. The mean time to the 50% reduction in physiologic tumor volume was 19.9 days and after combined external irradiation and HDR to 24.9 Gy. Conclusion: These results indicate that physiologic tumor volume determination by FDG-PET is feasible and that a 50% physiologic tumor volume reduction occurs within 20 days of starting therapy.

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

    PubMed

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

    2010-01-01

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

  2. (18) F-FDG PET/CT for planning external beam radiotherapy alters therapy in 11% of 581 patients.

    PubMed

    Birk Christensen, Charlotte; Loft-Jakobsen, Annika; Munck Af Rosenschöld, Per; Højgaard, Liselotte; Roed, Henrik; Berthelsen, Anne K

    2017-02-06

    (18) F-FDG PET/CT (FDG PET/CT) used in radiotherapy planning for extra-cerebral malignancy may reveal metastases to distant sites that may affect the choice of therapy. To investigate the role of FDG PET/CT on treatment strategy changes induced by the use of PET/CT as part of the radiotherapy planning. 'A major change of treatment strategy' was defined as either including more lesions in the gross tumour volume (GTV) distant from the primary tumour or a change in treatment modalities. The study includes 581 consecutive patients who underwent an FDG PET/CT scan for radiotherapy planning in our institution in the year 2008. All PET/CT scans were performed with the patient in treatment position with the use of immobilization devices according to the intended radiotherapy treatment. All scans were evaluated by a nuclear medicine physician together with a radiologist to delineate PET-positive GTV (GTV-PET). For 63 of the patients (11%), the PET/CT simulation scans resulted in a major change in treatment strategy because of the additional diagnostic information. Changes were most frequently observed in patients with lung cancer (20%) or upper gastrointestinal cancer (12%). In 65% of the patients for whom the PET/CT simulation scan revealed unexpected dissemination, radiotherapy was given - changed (n = 38) or unchanged (n = 13) according to the findings on the FDG PET/CT. Unexpected dissemination on the FDG PET/CT scanning performed for radiotherapy planning caused a change in treatment strategy in 11% of 581 patients. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  3. Comparative Analysis between [(18)F]Fludarabine-PET and [(18)F]FDG-PET in a Murine Model of Inflammation.

    PubMed

    Hovhannisyan, Narinée; Dhilly, Martine; Guillouet, Stéphane; Leporrier, Michel; Barré, Louisa

    2016-06-06

    Lymphoma research has advanced thanks to introduction of [(18)F]fludarabine, a positron-emitting tool. This novel radiotracer has been shown to display a great specificity for lymphoid tissues. However, in a benign process such as inflammation, the uptake of this tracer has not been questioned. Indeed, in inflammatory zones, elevated glucose metabolism rate may result in false-positives with [(18)F]FDG-PET Imaging. In the present investigation, it has been argued that cells, involved in inflammation, might be less avid of [(18)F]fludarabine. To generate inflammation, Swiss mice were intramuscularly injected with 0.1 mL of turpentine oil into the right front paw. Imaging sessions with (18)F-labeled tracers named above were conducted on days 5 and 25 after inoculation. For each animal, volumes of interest (VOI), delineating the muscle of the inflamed (IP) and normal paws (NP), were determined on PET scans. For characterization of inflammation, muscle samples from IP and NP were stained with hematoxylin and eosin (H&E). In early (day 5) inflammation, [(18)F]FDG accumulation was 4.00 ± 1.65 times greater in the IP than in the contralateral NP; for [(18)F]fludarabine, this IP/NP ratio was 1.31 ± 0.28, resulting in a significant difference between radiotracer groups (p < 0.01). In late (day 25) inflammation, the IP/NP ratios were 2.07 ± 0.49 and 1.03 ± 0.07, for [(18)F]FDG and [(18)F]fludarabine, respectively (p < 0.001). [(18)F]Fludarabine showed significantly weaker uptake in inflammation when compared with [(18)F]FDG. This encouraging finding suggests that [(18)F]fludarabine-PET might well be a robust approach for distinguishing tumor from inflammatory tissue, avoiding false-positive PET results and thus enabling an accurate imaging of lymphoma.

  4. Quantitative assessment of atherosclerotic plaques on (18)F-FDG PET/MRI: comparison with a PET/CT hybrid system.

    PubMed

    Li, Xiang; Heber, Daniel; Rausch, Ivo; Beitzke, Dietrich; Mayerhoefer, Marius E; Rasul, Sazan; Kreissl, Michael; Mitthauser, Markus; Wadsak, Wolfgang; Hartenbach, Markus; Haug, Alexander; Zhang, Xiaoli; Loewe, Christian; Beyer, Thomas; Hacker, Marcus

    2016-07-01

    PET with (18)F-FDG has the potential to assess vascular macrophage metabolism. (18)F-FDG is most often used in combination with contrast-enhanced CT to localize increased metabolism to specific arterial lesions. Novel (18)F-FDG PET/MRI hybrid imaging shows high potential for the combined evaluation of atherosclerotic plaques, due to the superior morphological conspicuity of plaque lesions. The purpose of this study was to evaluate the reliability and accuracy of (18)F-FDG PET/MRI uptake quantification compared to PET/CT as a reference standard in patients with carotid atherosclerotic plaques. The study group comprised 34 consecutive oncological patients with carotid plaques who underwent both PET/CT and PET/MRI with (18)F-FDG on the same day. The presence of atherosclerotic plaques was confirmed by 3 T MRI scans. Maximum standardized uptake values (SUVmax) for carotid plaque lesions and the average SUV of the blood pool within the adjacent internal jugular vein were determined and target-to-blood ratios (TBRs, plaque to blood pool) were calculated. Atherosclerotic lesions with maximum colocalized focal FDG uptake were assessed in each patient. SUVmax values of carotid plaque lesions were significantly lower on PET/MRI than on PET/CT (2.3 ± 0.6 vs. 3.1 ± 0.6; P < 0.01), but were significantly correlated between PET/CT and PET/MRI (Spearman's r = 0.67, P < 0.01). In contrast, TBRmax values of plaque lesions were similar on PET/MRI and on PET/CT (2.2 ± 0.3 vs. 2.2 ± 0.3; P = 0.4), and again were significantly correlated between PET/MRI and PET/CT (Spearman's r = 0.73, P < 0.01). Considering the increasing trend in SUVmax and TBRmax values from early to delayed imaging time-points on PET/CT and PET/MRI, respectively, with continuous clearance of radioactivity from the blood, a slight underestimation of TBRmax values may also be expected with PET/MRI compared with PET/CT. SUVmax and TBRmax values are widely accepted reference

  5. Cerebral Toxoplasmosis Masquerading Cns Lymphoma on FDG PET-CT in Post Renal Transplant Patient.

    PubMed

    Mukherjee, Anirban; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

    2017-01-01

    20 year old post renal transplant patient developed recurrent episodes of seizure. MRI revealed focal lesion in right parieto-occipital lobe with perilesional edema. FDG PET-CT revealed multiple hypermetabolic lesions in bilateral cerebral hemisphere. Subsequent biopsy from the lesion demonstrated bradyzoites of Toxoplasma gondii with inflammatory cells and thereby, a confirmatory diagnosis of cerebral toxoplasmosis was made. This case demonstrates the fact that increased FDG uptake in cerebral lesions in post transplant patient should be interpreted with caution and confirmed with histopathological correlation.

  6. Cerebral Toxoplasmosis Masquerading Cns Lymphoma on FDG PET-CT in Post Renal Transplant Patient

    PubMed Central

    Mukherjee, Anirban; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

    2017-01-01

    20 year old post renal transplant patient developed recurrent episodes of seizure. MRI revealed focal lesion in right parieto-occipital lobe with perilesional edema. FDG PET-CT revealed multiple hypermetabolic lesions in bilateral cerebral hemisphere. Subsequent biopsy from the lesion demonstrated bradyzoites of Toxoplasma gondii with inflammatory cells and thereby, a confirmatory diagnosis of cerebral toxoplasmosis was made. This case demonstrates the fact that increased FDG uptake in cerebral lesions in post transplant patient should be interpreted with caution and confirmed with histopathological correlation. PMID:28533649

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

    PubMed

    Kang, Sungmin

    2013-06-01

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

  8. Breast implant foreign body reaction mimicking breast cancer recurrence on FDG PET/CT.

    PubMed

    Ulaner, Gary A; D'Andrea, Gabriella; Cody, Hiram S

    2013-06-01

    A woman with bilateral breast cancer treated with bilateral mastectomies, implant reconstructions, chemotherapy, and hormonal therapy underwent FDG PET/CT imaging. Imaging demonstrated sternal, nodal, and lung lesions which were stable or slowly increasing, as well as a parasternal chest wall mass which was enlarging much more rapidly and was excised. Pathology of the chest wall mass demonstrated only benign soft tissue with fat necrosis and foreign body giant cell reaction, without evidence of malignancy or implant rupture. This case demonstrates how a benign FDG-avid foreign body reaction, induced by an intact breast prosthesis, could easily be mistaken for malignancy.

  9. Multiorgan Involvement of Chemotherapy-Induced Sarcoidosis Mimicking Progression of Lymphoma on FDG PET/CT.

    PubMed

    Sanan, Prateek; Lu, Yang

    2017-09-01

    A 35-year-old woman with biopsy-proven recurrent Hodgkin lymphoma in the neck lymph nodes received salvage chemotherapy of brentuximab/insulin growth factor-methotrexate. Although the patient continued doing well clinically with no constitutional symptoms or significant laboratory abnormalities following the second recurrence, subsequent FDG PET CT examinations over the next 2 years revealed multiple new FDG-avid foci including lymph nodes above/below the diaphragm, liver, spleen, lungs, and bone. An alternate diagnosis of chemotherapy-induced sarcoidosis was suggested and confirmed on both bone marrow and right inguinal node biopsy.

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

    SciTech Connect

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

    1994-05-01

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

  11. Histopathologic Validation of Lymph Node Staging With FDG-PET Scan in Cancer of the Esophagus and Gastroesophageal Junction

    PubMed Central

    Lerut, Toni; Flamen, Patrick; Ectors, Nadine; Van Cutsem, Erik; Peeters, Marc; Hiele, Martin; De Wever, Walter; Coosemans, Willy; Decker, Georges; De Leyn, Paul; Deneffe, Georges; Van Raemdonck, Dirk; Mortelmans, Luc

    2000-01-01

    Objective To assess the value of positron emission tomography with 18fluorodeoxyglucose (FDG-PET) for preoperative lymph node staging of patients with primary cancer of the esophagus and gastroesophageal junction. Summary Background Data FDG-PET appears to be a promising tool in the preoperative staging of cancer of the esophagus and gastroesophageal junction. Recent reports indicate a higher sensitivity and specificity for detection of stage IV disease and a higher specificity for diagnosis of lymph node involvement compared with the standard use of computed tomography and endoscopic ultrasound. Methods Forty-two patients entered the prospective study. All underwent attenuation-corrected FDG-PET imaging of the neck, thorax, and upper abdomen, a spiral computed tomography scan, and an endoscopic ultrasound. The gold standard consisted exclusively of the histology of sampled nodes obtained by extensive two-field or three-field lymphadenectomies (n = 39) or from guided biopsies of suspicious distant nodes indicated by imaging (n = 3). Results The FDG-PET scan had lower accuracy for the diagnosis of locoregional nodes (N1–2) than combined computed tomography and endoscopic ultrasound (48% vs. 69%) because of a significant lack of sensitivity (22% vs. 83%). The accuracy for distant nodal metastasis (M+Ly), however, was significantly higher for FDG-PET than the combined use of computed tomography and endoscopic ultrasound (86% vs. 62%). Sensitivity was not significantly different, but specificity was greater (90% vs. 69%). The FDG-PET scan correctly upstaged five patients (12%) from N1–2 stage to M+Ly stage. One patient was falsely downstaged by FDG-PET scanning. Conclusions FDG-PET scanning improves the clinical staging of lymph node involvement based on the increased detection of distant nodal metastases and on the superior specificity compared with conventional imaging modalities. PMID:11088069

  12. Multicenter Standardized 18F-FDG PET Diagnosis of Mild Cognitive Impairment, Alzheimer’s Disease, and Other Dementias

    PubMed Central

    Mosconi, Lisa; Tsui, Wai H.; Herholz, Karl; Pupi, Alberto; Drzezga, Alexander; Lucignani, Giovanni; Reiman, Eric M.; Holthoff, Vjera; Kalbe, Elke; Sorbi, Sandro; Diehl-Schmid, Janine; Perneczky, Robert; Clerici, Francesca; Caselli, Richard; Beuthien-Baumann, Bettina; Kurz, Alexander; Minoshima, Satoshi; de Leon, Mony J.

    2013-01-01

    This multicenter study examined 18F-FDG PET measures in the differential diagnosis of Alzheimer’s disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB) from normal aging and from each other and the relation of disease-specific patterns to mild cognitive impairment (MCI). Methods We examined the 18F-FDG PET scans of 548 subjects, including 110 healthy elderly individuals (“normals” or NLs), 114 MCI, 199 AD,98FTD, and 27 DLB patients, collected at 7 participating centers. Individual PET scans were Z scored using automated voxel-based comparison with generation of disease-specific patterns of cortical and hippocampal 18F-FDG uptake that were then applied to characterize MCI. Results Standardized disease-specific PET patterns were developed that correctly classified 95%AD, 92% DLB,94%FTD,and 94%NL. MCI patients showed primarily posterior cingulate cortex and hippocampal hypometabolism (81%), whereas neocortical abnormalities varied according to neuropsychological profiles. An AD PET pattern was observed in 79% MCI with deficits in multiple cognitive domains and 31% amnesic MCI. 18F-FDG PET heterogeneity in MCI with nonmemory deficits ranged from absent hypometabolism to FTD and DLB PET patterns. Conclusion Standardized automated analysis of 18F-FDG PET scans may provide an objective and sensitive support to the clinical diagnosis in early dementia. PMID:18287270

  13. Staging of recurrent and advanced lung cancer with 18F-FDG PET in a coincidence technique (hybrid PET).

    PubMed

    Schmid, R A; Hautmann, H; Poellinger, B; Kellner, W; Moisseev, A; Brinkbaeumer, K; Weiss, M; Hahn, K; Dresel, S

    2003-01-01

    The aim of this study was to evaluate [18F]fluorodeoxyglucose ( F-FDG) imaging of recurrent or inoperable lung cancer using a hybrid positron emission tomography (PET) device of the third generation. Examinations were compared with the results of conventional staging. Thirty-six patients suffering from recurrent or primarily inoperable lung cancer (29 men, seven women; age 64.8+/-12.0 years) were examined using hybrid PET (Marconi Axis gamma-PET ) 60 min after injection of 370 MBq F-FDG. The data obtained were reconstructed iteratively. All patients received a computed tomography (CT) scan using either the spiral or multislice technique. All lesions suspicious for primary or recurrent tumour were verified by biopsy; mediastinal lymph nodes were considered as malignant, when positive histology or a small axis diameter of greater than 1 cm measured with CT in addition to progression of clinical course was found. Distant metastases were diagnosed by CT and bone scintigraphy. Using hybrid PET all lesions showed a focally elevated glucose metabolism. Lymph node involvement of the ipsilateral peribronchial and hilar station (N1) was identified in 24/26 cases (92%), in 26/29 cases (90%) of ipsilateral central manifestation (N2) and in 11/13 (85%) cases of central contralateral or supraclavicular lymphatic infestation (N3). Pulmonary spread in hybrid PET was found in 4/8 cases (50%), whereas mainly lung metastases with a diameter of 1.5 cm and smaller were missed. Pleural involvement diagnosed by CT was verified in 4/5 patients. All four patients with bony metastases in conventional staging also presented with positive findings in hybrid PET (8/9 lesions). Concordance with conventional staging was found in 28/36 of patients (78%). In 4/36 patients (11%) unknown sites of tumour were detected leading to therapeutic consequences in three patients after radiological confirmation. Hybrid PET would have led to an understaging in four cases (11%), resulting theoretically in

  14. FDG-PET in the selection of brain lesions for biopsy

    SciTech Connect

    Hanson, M.W.; Glantz, M.J.; Hoffman, J.M.; Friedman, A.H.; Burger, P.C.; Schold, S.C.; Coleman, R.E. )

    1991-09-01

    The CT-guided stereotaxic needle biopsy has become a widely used procedure in the diagnostic evaluation of intracranial lesions including tumors. Conventional CT or MR frequently defines the anatomic regions of abnormality, which may be multiple lesions or a single lesion that is heterogeneous in cellular composition owing to the topographic variation of cellular constituency or the combination of active disease, nonspecific inflammation, necrosis, and/or edema. In these cases, selection of the most appropriate site for a successful diagnostic needle biopsy can be difficult. In three patients, we have used (18F)fluorodeoxyglucose (FDG) positron emission tomography (PET) to determine the site most likely to provide a diagnostic biopsy result. In the first patient, who presented with confusion, multiple biopsies from the temporal lobe, based on MR abnormalities, revealed only reactive gliosis and edema. Repeat biopsy directed by PET revealed an anaplastic astrocytoma. In a second patient, PET allowed us to differentiate radiation effect from active metastatic breast cancer. In the third patient, who presented with a grand mal seizure, biopsy of a CT-defined hypodense region demonstrated lymphocytosis. Metabolism of FDG was normal or increased in areas of Aspergillus encephalitis at autopsy. These preliminary studies suggest a complementary role for FDG-PET and CT or MR in selected patients for defining the intracranial site most likely to yield a positive biopsy result.

  15. The role of FDG-PET/CT in the evaluation of residual disease in paediatric non-Hodgkin lymphoma.

    PubMed

    Bhojwani, Deepa; McCarville, Mary B; Choi, John K; Sawyer, Jennifer; Metzger, Monika L; Inaba, Hiroto; Davidoff, Andrew M; Gold, Robert; Shulkin, Barry L; Sandlund, John T

    2015-03-01

    (18) F-labelled-fluorodeoxyglucose positron emission tomography (FDG-PET) findings are challenging to interpret for residual disease versus complete response in paediatric patients with non-Hodgkin lymphoma (NHL). A biopsy is often warranted to confirm the presence or absence of viable tumour if there is clinical or radiographic evidence of residual disease. In this study, we compared conventional imaging and FDG-PET/computerized tomography (CT) findings with biopsy results in 18 children with NHL. Our goal was to provide additional data to establish more reliable criteria for response evaluation. Residual disease was suspected after conventional imaging alone in eight patients, after FDG-PET/CT alone in three and after both modalities in seven patients. Biopsy confirmed the presence of viable tumour in two patients. Two additional patients experienced progressive disease or relapse. The sensitivity and negative predictive value of FDG-PET/CT using the London criteria to indicate residual tumour detectable by biopsy were 100%, but specificity was low (60%), as was the positive predictive value (25%). Thus, in this study, a negative FDG-PET/CT finding was a good indicator of complete remission. However, because false-positive FDG-PET/CT findings are common, biopsy and close monitoring are required for accurate determination of residual disease in individual patients.

  16. Influence of Co-57 and CT Transmission Measurements on the Quantification Accuracy and Partial Volume Effect of a Small Animal PET Scanner.

    PubMed

    Mannheim, Julia G; Schmid, Andreas M; Pichler, Bernd J

    2017-03-30

    Non-invasive in vivo positron emission tomography (PET) provides high detection sensitivity in the nano- to picomolar range and in addition to other advantages, the possibility to absolutely quantify the acquired data. The present study focuses on the comparison of transmission data acquired with an X-ray computed tomography (CT) scanner or a Co-57 source for the Inveon small animal PET scanner (Siemens Healthcare, Knoxville, TN, USA), as well as determines their influences on the quantification accuracy and partial volume effect (PVE). A special focus included the impact of the performed calibration on the quantification accuracy. Phantom measurements were carried out to determine the quantification accuracy, the influence of the object size on the quantification, and the PVE for different sphere sizes, along the field of view and for different contrast ratios. An influence of the emission activity on the Co-57 transmission measurements was discovered (deviations up to 24.06 % measured to true activity), whereas no influence of the emission activity on the CT attenuation correction was identified (deviations <3 % for measured to true activity). The quantification accuracy was substantially influenced by the applied calibration factor and by the object size. The PVE demonstrated a dependency on the sphere size, the position within the field of view, the reconstruction and correction algorithms and the count statistics. Depending on the reconstruction algorithm, only ∼30-40 % of the true activity within a small sphere could be resolved. The iterative 3D reconstruction algorithms uncovered substantially increased recovery values compared to the analytical and 2D iterative reconstruction algorithms (up to 70.46 % and 80.82 % recovery for the smallest and largest sphere using iterative 3D reconstruction algorithms). The transmission measurement (CT or Co-57 source) to correct for attenuation did not severely influence the PVE. The analysis of the quantification

  17. Multiple values of (18)F-FDG PET/CT in idiopathic inflammatory myopathy.

    PubMed

    Li, Yuan; Zhou, Yunshan; Wang, Qian

    2017-08-22

    This study aimed to investigate the multiple values of (18)F-FDG PET/CT in detecting malignant tumors, evaluating myopathy, and determining interstitial lung disease in patients with idiopathic inflammatory myopathy (IIM). We retrospectively analyzed the data of 38 patients who were examined by (18)F-FDG PET/CT and eventually diagnosed as IIM. We also collected the data of another 22 cases with negative PET/CT as the control. Pulmonary HRCT images were acquired simultaneously with regular (18)F-FDG PET/CT imaging for each patient. Image analysis included the presence of malignant lesions, muscular FDG uptake, and interstitial lung disease and its imaging features. IIM was classified into polymyositis (PM), classic dermatomyositis (CDM), and clinical amyopathic dermatomyositis (CADM). All suspected malignant lesions were confirmed by histopathological examination. Interstitial lung disease was diagnosed by HRCT. Rapidly progressive interstitial lung disease (RP-ILD) was determined according to clinical follow-ups. The significance of (18)F-FDG PET/CT in the detection of malignancy, observation of activity of myopathy, and determination of interstitial lung disease in IIM patients was explored based on the final clinical diagnosis. In the 38 patients with IIM, 3 cases were classified as PM, 18 as CDM, and 17 as CADM. PET/CT correctly detected 7 cases (18.4%) of malignant tumors, and all of which were found in CDM and PM patients. The muscular FDG uptake in IIM patients was higher than the control population, and it was higher in patients with myopathy (including PM and CDM) than in patients with CADM. The muscular FDG uptake in IIM patients was correlated with elevated serum creatine kinase level (r = 0.332, P = 0.042) and impaired muscle strength (r = -0.605, P < 0.001). Interstitial lung disease was detected by HRCT in 30 patients (78.9%), and 7 of them were eventually confirmed as RP-ILD, according to the clinical outcome. The FDG uptake in lung lesions of

  18. The impact of FDG-PET/CT in the management of patients with vulvar and vaginal cancer.

    PubMed

    Robertson, N L; Hricak, H; Sonoda, Y; Sosa, R E; Benz, M; Lyons, G; Abu-Rustum, N R; Sala, E; Vargas, H A

    2016-03-01

    To evaluate the changes in prognostic impression and patient management following PET/CT in patients with vulvar and vaginal carcinoma; and to compare PET/CT findings with those of conventional imaging modalities. We summarized prospectively and retrospectively collected data for 50 consecutive patients from our institution that enrolled in the National Oncologic PET Registry and underwent FDG-PET/CT for a suspected or known primary or recurrent vulvar/vaginal cancer. 54/83 (65%) studies included had a diagnosis of vulvar cancer, and the remaining 29/83 (35%), a diagnosis of vaginal cancer. Following FDG-PET/CT, the physician's prognostic impression changed in 51% of cases. A change in patient management, defined as a change to/from a non-interventional strategy (observation or additional imaging), to/from an interventional strategy (biopsy or treatment), was documented in 36% of studies. The electronic records demonstrated that 95% of the management strategies recorded in the physician questionnaires were implemented as planned. MRI and/or CT were performed within one month of the FDG-PET/CT in 20/83 (24%) and 28/83 (34%) cases, respectively. FDG-PET/CT detected nodes suspicious for metastases on 29/83 (35%) studies performed. MRI and CT detected positive nodes on 6 and 11 studies respectively. Distant metastases were identified in 10 cases imaged with FDG-PET and 5 cases that had additional conventional CT imaging. All suspicious lesions seen on CT were positively identified on PET/CT. In 4 cases, an abnormality identified on PET/CT, was not seen on diagnostic CT. FDG-PET/CT may play an important role in the management of vulvar and vaginal carcinoma. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Repetitive (18)F-FDG-PET/CT in patients with large-vessel giant-cell arteritis and controlled disease.

    PubMed

    de Boysson, Hubert; Aide, Nicolas; Liozon, Eric; Lambert, Marc; Parienti, Jean-Jacques; Monteil, Jacques; Huglo, Damien; Bienvenu, Boris; Manrique, Alain; Aouba, Achille

    2017-08-30

    (18)F-FDG PET/CT can detect large-vessel involvement in giant-cell arteritis (GCA) with a good sensitivity. In patients with clinically and biologically controlled disease, we aimed to assess how vascular uptakes evolve on repetitive FDG-PET/CT. All included patients had to satisfy the 4 following criteria: 1) diagnosis of GCA was retained according to the criteria of the American College of Rheumatology or based on the satisfaction of 2 criteria associated with the demonstration of large-vessel involvement on FDG-PET/CT; 2) all patients had a positive PET/CT that was performed at diagnosis before treatment or within the first 10days of treatment; 3) another FDG-PET/CT was performed after at least 3months of controlled disease without any relapse; 4) patients were followed-up at least for 12months. Twenty-five patients (17 [68%] women, median age: 69 [65-78]) with large-vessel inflammation on a baseline FDG-PET/CT and with repetitive imaging during the period with controlled disease were included and followed-up for 62 [25-95] months. Four repeated procedures revealed total extinction of vascular uptakes at 11.5 [8-12] months after the first FDG-PET/CT. Eight PET/CT revealed decreased numbers of vascular uptakes, and 10 procedures revealed no changes. The 3 remaining procedures indicated worsening of the numbers of vascular uptakes in the absence of relapse. Our study revealed long-term persistent vascular uptake on repeated FDG-PET/CT in >80% of our GCA patients with large-vessel inflammation and clinical-biological controlled disease. Prospective studies are required to confirm these findings. Copyright © 2017 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  20. Semiquantitative Assessment of (18)F-FDG Uptake in the Normal Skeleton: Comparison Between PET/CT and Time-of-Flight Simultaneous PET/MRI.

    PubMed

    Minamimoto, Ryogo; Xu, Guofan; Jamali, Mehran; Holley, Dawn; Barkhodari, Amir; Zaharchuk, Greg; Iagaru, Andrei

    2017-08-04

    Differences in the attenuation correction methods used in PET/CT scanners versus the newly introduced whole-body simultaneous PET/MRI reportedly result in differences in standardized uptake values (SUVs) in the normal skeleton. The aim of the study was to compare the semiquantitative FDG uptake in the normal skeleton using time-of-flight (TOF) PET/MRI versus PET/CT with and without TOF. Participants received a single FDG injection and underwent non-TOF and TOF PET/CT (n = 23) or non-TOF PET/CT and TOF PET/MRI (n = 50). Mean SUV (SUVmean) and maximum SUV (SUVmax) were measured from all PET scans for nine normal regions of the skeleton. Pearson correlation coefficients (r) were used to evaluate the SUVmax and SUVmean of normal skeleton between non-TOF and TOF PET/CT, as well as between non-TOF PET/CT and TOF PET/MRI. In addition, percentage differences in SUVmax and SUVmean of the normal skeleton between non-TOF and TOF PET/CT and between non-TOF PET/CT and TOF PET/MRI were evaluated. The SUVmax and SUVmean in the normal skeleton significantly increased between non-TOF and TOF PET/CT, but they significantly decreased between non-TOF PET/CT and TOF PET/MRI. The SUVmax and SUVmean in normal skeleton showed good correlation between non-TOF PET/CT and TOF PET/MRI (SUVmax, r = 0.88; SUVmean, r = 0.91) and showed a similar trend between non-TOF and TOF PET/CT (SUVmax, r = 0.88; SUVmean, r = 0.94). In the normal skeleton, SUVmax and SUVmean showed high correlations between PET/MRI and PET/CT. The MRI attenuation correction used in TOF PET/MRI provides reliable semiquantitative measurements in the normal skeleton.

  1. Role of 18F-FDG PET in the management of gestational trophoblastic neoplasia.

    PubMed

    Mapelli, P; Mangili, G; Picchio, M; Gentile, C; Rabaiotti, E; Giorgione, V; Spinapolice, E G; Gianolli, L; Messa, C; Candiani, M

    2013-04-01

    Gestational trophoblastic neoplasia (GTN) is a rare and aggressive tumour that is usually sensitive to chemotherapy. The usefulness of conventional imaging modalities in evaluating treatment response is limited, mainly due to the difficulty in differentiating between residual tumour tissue and necrosis. The aim of the present study was to evaluate the role of FDG PET or PET/CT in primary staging and in monitoring treatment efficacy. The effect of FDG PET and combined PET/CT on the management of patients with GTN was also evaluated comparing the differences between standard treatments based on conventional imaging and alternative treatments based on PET. This retrospective study included 41 patients with GTN referred to San Raffaele Hospital between 2002 and 2010. All patients were studied by either PET or PET/CT in addition to conventional imaging. Of the 41 patients, 38 were evaluated for primary staging of GTN and 3 patients for chemotherapy resistance after first-line chemotherapy performed in other Institutions. To validate the PET data, PET and PET/CT findings were compared with those from conventional imaging, including transvaginal ultrasonography (TV-US) in those with uterine disease, CT and chest plain radiography in those with lung disease and whole-body CT in those with systemic metastases. Conventional imaging was considered positive for the presence of uterine disease and/or metastases when abnormal findings relating to GTN were reported. PET and PET/CT were considered concordant with conventional imaging when metabolic active disease was detected at the sites corresponding to the pathological findings on conventional imaging. In addition, in 12 of the 41 patients showing extrauterine disease, FDG PET/CT was repeated to monitor treatment efficacy, in 8 after normalization of beta human chorionic gonadotropin (βHCG) and in 4 with βHCG resistance. In some patients, PET or PET/CT findings led to an alternative nonconventional treatment, and this was

  2. Repeatability of quantitative FDG-PET/CT and contrast enhanced CT in recurrent ovarian carcinoma: test retest measurements for tumor FDG uptake, diameter and volume

    PubMed Central

    Rockall, Andrea G.; Avril, Norbert; Lam, Raymond; Iannone, Robert; Mozley, P. David; Parkinson, Christine; Bergstrom, Donald; Sala, Evis; Sarker, Shah-Jalal; McNeish, Iain A.; Brenton, James D.

    2014-01-01

    Purpose Repeatability of baseline FDG-PET/CT measurements has not been tested in ovarian cancer. This dual-center, prospective study assessed variation in tumor FDG uptake, tumor diameter (TD) and tumor volume (TV) from sequential FDG-PET/CT and contrast-enhanced CT (CECT) in patients with recurrent platinum-sensitive ovarian cancer. Methods Patients underwent two pre-treatment baseline FDG-PET/CT (n=21) and CECT (n=20) at 2 clinical sites with different PET/CT instruments. Patients were included if they had at least one target lesion (TL) in the abdomen with an SUV maximum (SUVmax) of ≥2.5 and a long axis diameter of ≥15mm. Two independent reading methods were used to evaluate repeatability of TD and SUV uptake: on site and at an imaging clinical research organization (CRO). TV reads were only performed by CRO. In each reading set, TLs were independently measured on sequential imaging. Results Median time between FDG-PET/CT was 2 days (range 1-7). For site reads, concordance correlation coefficient (CCC) for SUVmean, SUVmax and TD were 0.95, 0.94 and 0.99 respectively. Repeatability coefficients were 16.3%, 17.3% and 8.8% for SUVmean, SUVmax and TD respectively. Similar results were observed for CRO reads. TV CCC was 0.99 with a repeatability coefficient of 28.1%. Conclusions There was excellent test/retest repeatability for FDG-PET/CT quantitative measurements across two sites and two independent reading methods. Cut-off values for determining change in SUVmean, SUVmax and TV establish limits to determine metabolic and/or volumetric response to treatment in platinum-sensitive relapsed ovarian cancer. PMID:24573555

  3. FDG-PET/CT during concomitant chemo radiotherapy for esophageal cancer: Reducing target volumes to deliver higher radiotherapy doses.

    PubMed

    Nkhali, Lamyaa; Thureau, Sébastien; Edet-Sanson, Agathe; Doyeux, Kaya; Benyoucef, Ahmed; Gardin, Isabelle; Michel, Pierre; Vera, Pierre; Dubray, Bernard

    2015-06-01

    A planning study investigated whether reduced target volumes defined on FDG-PET/CT during radiotherapy allow total dose escalation without compromising normal tissue tolerance in patients with esophageal cancer. Ten patients with esophageal squamous cell carcinoma (SCC), candidate to curative-intent concomitant chemo-radiotherapy (CRT), had FDG-PET/CT performed in treatment position, before and during (Day 21) radiotherapy (RT). Four planning scenarios were investigated: 1) 50 Gy total dose with target volumes defined on pre-RT FDG-PET/CT; 2) 50 Gy with boost target volume defined on FDG-PET/CT during RT; 3) 66 Gy with target volumes from pre-RT FDG-PET/CT; and 4) 66 Gy with boost target volume from during-RT FDG-PET/CT. The median metabolic target volume decreased from 12.9 cm3 (minimum 3.7-maximum 44.8) to 5.0 cm3 (1.7-13.5) (p=0.01) between pre- and during-RCT FDG-PET/CT. The median PTV66 was smaller on during-RT than on baseline FDG-PET/CT [108 cm3 (62.5-194) vs. 156 cm3 (68.8-251), p=0.02]. When total dose was set to 50 Gy, planning on during-RT FDG-PET/CT was associated with a marginal reduction in normal tissues irradiation. When total dose was increased to 66 Gy, planning on during-RT PET yielded significantly lower doses to the spinal cord [Dmax=44.1Gy (40.8-44.9) vs. 44.7Gy (41.5-45.0), p=0.007] and reduced lung exposure [V20Gy=23.2% (17.3-27) vs. 26.8% (19.7-30.2), p=0.006]. This planning study suggests that adaptive RT based on target volume reduction assessed on FDG-PET/CT during treatment could facilitate dose escalation up to 66 Gy in patients with esophageal SCC.

  4. Prognostic value of pretransplant FDG-PET in refractory/relapsed Hodgkin lymphoma treated with autologous stem cell transplantation: systematic review and meta-analysis.

    PubMed

    Adams, Hugo J A; Kwee, Thomas C

    2016-04-01

    This study aimed to systematically review the prognostic value of pretransplant (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in refractory/relapsed Hodgkin lymphoma treated with autologous stem cell transplantation (SCT). MEDLINE was systematically searched for appropriate studies. Included studies were methodologically appraised. Results of individual studies were meta-analyzed, if possible. Eleven studies, comprising a total of 745 refractory/relapsed Hodgkin lymphoma patients who underwent FDG-PET before autologous SCT, were included. The overall methodological quality of these studies was moderate. The proportion of pretransplant FDG-PET positive patients ranged between 25 and 65.2 %. Progression-free survival ranged between 0 and 52 % in pretransplant FDG-PET positive patients, and between 55 and 85 % in pretransplant FDG-PET negative patients. Overall survival ranged between 17 and 77 % in pretransplant FDG-PET positive patients, and between 78 and 100 % in FDG-PET negative patients. Based on five studies that provided sufficient data for meta-analysis, pooled sensitivity and specificity of pretransplant FDG-PET in predicting treatment failure (i.e., either progressive, residual, or relapsed disease) were 67.2 % (95 % confidence interval [CI] 58.2-75.3 %) and 70.7 % (95 % CI 64.2-76.5 %), respectively. Based on two studies that provided sufficient data for meta-analysis, pooled sensitivity and specificity of pretransplant FDG-PET in predicting death during follow-up were 74.4 % (95 % CI 58.8-86.5 %) and 58.0 % (95 % CI 49.3-66.3 %), respectively. In conclusion, the moderate quality evidence suggests pretransplant FDG-PET to have value in predicting outcome in refractory/relapsed Hodgkin lymphoma patients treated with autologous SCT. Nevertheless, a considerable proportion of pretransplant FDG-PET positive patients remains disease free and a considerable proportion of pretransplant FDG-PET negative patients develops disease relapse

  5. FDG PET in the evaluation of phaeochromocytoma: a correlative study with MIBG scintigraphy and Ki-67 proliferative index.

    PubMed

    Lin, Michael; Wong, Vincent; Yap, June; Jin, Richard; Leong, Paul; Campbell, Peter

    2013-01-01

    To compare 123I-metaiodobenzylguanidine (MIBG) and [Fluorine-18]-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in 22 patients with phaeochromocytomas and paragangliomas (PGL) retrospectively and to evaluate the correlation between FDG uptake and Ki-67 proliferative index. Fourteen of 17 (82%) patients at initial diagnosis had positive FDG uptake, more intensely in PGL. Eleven of 12 (92%) patients had positive MIBG uptake. PET and MIBG scintigraphy were concordant in 10 patients, discordant in 6. Combined results yielded no false negative findings and are complementary. Neither maximum standardised uptake value nor visual scores on MIBG correlated with Ki-67. © 2013 Elsevier Inc. All rights reserved.

  6. 18F-FDG PET imaging in a patient with late omental infarction after treatment of pancreatic adenocarcinoma.

    PubMed

    Chassagnon, Guillaume; Metrard, Gilles; Besse, Hélène; Gauvain, Sabine

    2014-06-01

    We report a case of late omental infarction visualized by F-FDG PET/CT during follow-up for pancreatic adenocarcinoma. The 65-year-old patient was referred for imaging 8 months after pancreaticoduodenectomy and 2 months after completion of a course of chemotherapy. PET/CT showed an FDG-avid omental lesion that suggested peritoneal carcinomatosis. The appearance and evolution at follow-up studies confirmed the diagnosis of omental infarction, a rare complication of pancreatic surgery. This case revealed the possibility of late FDG uptake in omental infarction.

  7. FDG PET/CT images demonstrating Fournier gangrene with bilateral pelvic muscle extension in a patient with recurrent rectosigmoid cancer.

    PubMed

    Hsu, Chia-Tien; Kao, Pan-Fu; Huang, Chi-Chou; Huang, Hsin-Hui; Lee, Jong-Kang

    2014-01-01

    A 71-year-old male patient with Parkinsonism was referred for an F-FDG PET/CT scan for suspicious recurrence of rectosigmoid adenocarcinoma. The FDG PET/CT scan revealed increased FDG uptakes in the lower pelvic region around the wall of the rectal stump, with extension to the bilateral pelvic sidewalls and the right gluteous minimus muscle. In addition, multiple small air bubbles were noted in the lesions on the attenuation CT images. Fournier gangrene was diagnosed. After treatment with intravenous antibiotics and debridement with sigmoidoscopic irrigation, the patient was discharged and remained uneventful during clinical follow-up for 50 days.

  8. 18F-FDG PET/CT in the diagnosis of prosthetic valve endocarditis.

    PubMed

    Fagman, Erika; van Essen, Martijn; Fredén Lindqvist, Johan; Snygg-Martin, Ulrika; Bech-Hanssen, Odd; Svensson, Gunnar

    2016-04-01

    Recent studies have shown promising results using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in the diagnosis of prosthetic valve endocarditis (PVE). However, previous studies did not include negative controls. The aim of this study was to compare (18)F-FDG-uptake around prosthetic aortic valves in patients with and without PVE and to determine the diagnostic performance of (18)F-FDG PET/CT in the diagnosis of PVE. (18)F-FDG PET/CT examinations in patients with a prosthetic aortic valve performed 2008-2014 were retrieved. Eight patients with a final diagnosis of definite PVE were included in the analysis of the diagnostic performance of (18)F-FDG PET/CT. Examinations performed on suspicion of malignancy in patients without PVE (n = 19) were used as negative controls. Visual and semi-quantitative analysis was performed. Maximal standardized uptake value (SUVmax) in the valve area was measured and SUVratio was calculated by dividing valve SUVmax by SUVmax in the descending aorta. The sensitivity was 75 %, specificity 84 %, positive likelihood ratio [LR(+)] 4.8 and negative likelihood ratio [LR(-)] 0.3 on visual analysis. Both SUVmax and SUVratio were significantly higher in PVE patients [5.8 (IQR 3.5-6.5) and 2.4 (IQR 1.7-3.0)] compared to non-PVE patients [3.2 (IQR 2.8-3.8) and 1.5 (IQR 1.3-1.6)] (p < 0.001). ROC-curve analysis of SUVratio yielded an area under the curve of 0.90 (95 % CI 0.74-1.0). (18)F-FDG-uptake around non-infected aortic prosthetic valves was low. The level of (18)F-FDG-uptake in the prosthetic valve area showed a good diagnostic performance in the diagnosis of PVE.

  9. (18)F-FDG-PET/MRI in lymphoma patients.

    PubMed

    Ferdová, Eva; Ferda, Jiří; Baxa, Jan

    2017-01-23

    The introduction of hybrid PET/MRI imaging using integrated systems into clinical practice has opened up the possibility of reducing the radiation dose from hybrid imaging by eliminating the contribution from computed tomography. Studies comparing the possibilities of PET/CT and PET/MRI imaging demonstrated it is possible to use the advantages of the high contrast resolution of magnetic resonance for soft tissue and bone marrow along with PET records in a quality comparable to PET/CT imaging. The significant feature for PET imaging in Hodgkińs lymphoma is that it is a tissue with high levels of radiopharmaceutical accumulation, which decreases proportionally after successful therapeutic effect, the effect of therapy is assessed using Deauville score system on interim examinations. While the efficacy of prognosis determined using the Deauville scale in HL is widely accepted, it turns out that in DLBCL, the prognostic value of PET imaging is bound to the evaluation of subtypes. PET/MRI scanning can be used to evaluate a relapse if follicular lymphoma has already been treated, or to confirm transformation into more aggressive forms. In children and adults with Burkitt's lymphoma, negative findings after induction therapy have a high negative predictive value for relapse prognosis.

  10. Neurosarcoidosis on FET and FDG PET/CT.

    PubMed

    Chan, Mico; Hsiao, Edward

    2017-03-01

    O-(2-fluoroethyl)-L-tyrosine (FET) PET/CT is a promising imaging modality for brain tumor imaging because of its reported high sensitivity for biologically active tumor tissue. We present a case of biopsy-proven neurosarcoidosis showing FET uptake. It is an important cause of false-positive uptake on FET PET/CT.

  11. Functional pattern of brain FDG-PET in amyotrophic lateral sclerosis.

    PubMed

    Pagani, Marco; Chiò, Adriano; Valentini, Maria Consuelo; Öberg, Johanna; Nobili, Flavio; Calvo, Andrea; Moglia, Cristina; Bertuzzo, Davide; Morbelli, Silvia; De Carli, Fabrizio; Fania, Piercarlo; Cistaro, Angelina

    2014-09-16

    We investigated a large sample of patients with amyotrophic lateral sclerosis (ALS) at rest in order to assess the value of (18)F-2-fluoro-2-deoxy-d-glucose ((18)F-FDG) PET as a biomarker to discriminate patients from controls. A total of 195 patients with ALS and 40 controls underwent brain (18)F-FDG-PET, most within 5 months of diagnosis. Spinal and bulbar subgroups of ALS were also investigated. Twenty-five bilateral cortical and subcortical volumes of interest and cerebellum were taken into account, and (18)F-FDG uptakes were individually normalized by whole-brain values. Group analyses investigated the ALS-related metabolic changes. Discriminant analysis investigating sensitivity and specificity was performed using the 51 volumes of interest as well as age and sex. Metabolic connectivity was explored by voxel-wise interregional correlation analysis. Hypometabolism was found in frontal, motor, and occipital cortex and hypermetabolism in midbrain, temporal pole, and hippocampus in patients with ALS compared to controls. A similar metabolic pattern was also found in the 2 subgroups. Discriminant analysis showed a sensitivity of 95% and a specificity of 83% in separating patients from controls. Connectivity analysis found a highly significant positive correlation between midbrain and white matter in corticospinal tracts in patients with ALS. (18)F-FDG distribution changes in ALS showed a clear pattern of hypometabolism in frontal and occipital cortex and hypermetabolism in midbrain. The latter might be interpreted as the neurobiological correlate of diffuse subcortical gliosis. Discriminant analysis resulted in high sensitivity and specificity in differentiating patients with ALS from controls. Once validated by diseased-control studies, the present methodology might represent a potentially useful biomarker for ALS diagnosis. This study provides Class III evidence that (18)F-FDG-PET accurately distinguishes patients with ALS from normal controls (sensitivity 95

  12. Comparison of analytical methods of brain [(18)F]FDG-PET after severe traumatic brain injury.

    PubMed

    Madsen, Karine; Hesby, Sara; Poulsen, Ingrid; Fuglsang, Stefan; Graff, Jesper; Larsen, Karen B; Kammersgaard, Lars P; Law, Ian; Siebner, Hartwig R

    2017-08-12

    Loss of consciousness has been shown to reduce cerebral metabolic rates of glucose (CMRglc) measured by brain [(18)F]FDG-PET. Measurements of regional metabolic patterns by normalization to global cerebral metabolism or cerebellum may underestimate widespread reductions. The aim of this study was to compare quantification methods of whole brain glucose metabolism, including whole brain [18F]FDG uptake normalized to uptake in cerebellum, normalized to injected activity, normalized to plasma tracer concentration, and two methods for estimating CMRglc. Six patients suffering from severe traumatic brain injury (TBI) and ten healthy controls (HC) underwent a 10min static [(18)F]FDG-PET scan and venous blood sampling. Except from normalizing to cerebellum, all quantification methods found significant lower level of whole brain glucose metabolism of 25-33% in TBI patients compared to HC. In accordance these measurements correlated to level of consciousness. Our study demonstrates that the analysis method of the [(18)F]FDG PET data has a substantial impact on the estimated whole brain cerebral glucose metabolism in patients with severe TBI. Importantly, the SUVR method which is often used in a clinical setting was not able to distinguish patients with severe TBI from HC at the whole-brain level. We recommend supplementing a static [(18)F]FDG scan with a single venous blood sample in future studies of patients with severe TBI or reduced level of consciousness. This can be used for simple semi-quantitative uptake values by normalizing brain activity uptake to plasma tracer concentration, or quantitative estimates of CMRglc. Copyright © 2017. Published by Elsevier B.V.

  13. 18F-FDG PET/CT and extragastric MALT lymphoma: role of Ki-67 score and plasmacytic differentiation.

    PubMed

    Albano, Domenico; Bosio, Giovanni; Giubbini, Raffaele; Bertagna, Francesco

    2017-10-01

    The detection rate of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in extragastric mucosa associated lymphoid tissue (MALT) lymphoma is under debate and the reason is not clear. Our aim was to investigate the metabolic behavior of extragastric MALT lymphoma and whether the histological features (Ki-67 index and plasmacytic differentiation, PD) might explain it. PET/CT images were analyzed visually and semi-quantitatively and compared with Ki-67 index and PD. Seventy-two patients were included. Twelve of 18 patients with PD showed intense 18F-FDG uptake; on the contrary, 42 of 54 patients without PD had positive 18F-FDG PET/CT. Twenty-six of 27 patients with Ki-67 > 15% had 18F-FDG-avid lesions; 28 of 45 patients with Ki-67 ≤ 15% had positive 18F-FDG PET/CT. 18F-FDG avidity was significantly associated with Ki-67 index (p < .001) and not correlated with PD (p = .352). Maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio and lesion-to-blood pool SUVmax ratio were not correlated with Ki-67 index or PD. 18F-FDG avidity was noted in 75% and is correlated only with Ki-67.

  14. 18F-FDG PET/CT and PET/MRI Perform Equally Well in Cancer: Evidence from Studies on More Than 2,300 Patients

    PubMed Central

    Spick, Claudio; Herrmann, Ken; Czernin, Johannes

    2016-01-01

    18F-FDG PET/CT has become the reference standard in oncologic imaging against which the performance of other imaging modalities is measured. The promise of PET/MRI includes multiparametric imaging to further improve diagnosis and phenotyping of cancer. Rather than focusing on these capabilities, many investigators have examined whether 18F-FDG PET combined with mostly anatomic MRI improves cancer staging and restaging. After a description of PET/MRI scanner designs and a discussion of technical and operational issues, we review the available literature to determine whether cancer assessments are improved with PET/MRI. The available data show that PET/MRI is feasible and performs as well as PET/CT in most types of cancer. Diagnostic advantages may be achievable in prostate cancer and in bone metastases, whereas disadvantages exist in lung nodule assessments. We conclude that 18F-FDG PET/MRI and PET/CT provide comparable diagnostic information when MRI is used simply to provide the anatomic framework. Thus, PET/MRI could be used in lieu of PET/CT if this approach becomes economically viable and if reasonable workflows can be established. Future studies should explore the multiparametric potential of MRI. PMID:26742709

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

    PubMed

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

    2015-05-01

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

  16. Uterine leiomyosarcoma metastatic to thyroid shown by (18)F-FDG PET/CT imaging.

    PubMed

    Gauthé, M; Testart Dardel, N; Nascimento, C; Trassard, M; Banal, A; Alberini, J-L

    About one third of focal thyroid uptakes in a fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) study are malignant, the most frequent histological type being papillary carcinoma. Metastases to the thyroid account for approximately 7.5% of thyroid malignancies and come mainly from kidney, lung, head and neck, and breast cancers. We report the case of a 64-year-old woman presenting a fast growing thyroid nodule whose primitive or metastatic origin was not obvious, for which (18)F-FDG PET/CT helped in the diagnostic process and in the later management of the patient. Histopathologic findings finally revealed a metastasis of uterine leiomyosarcoma. Copyright © 2016 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  17. Inflammatory pseudotumour of the infratemporal fossa visualized with (18)F-FDG PET/CT.

    PubMed

    Cabrera Villegas, A; González Juez, B; Llorente Pendás, J L; Albornoz Almada, M C; Santos Holgueras, P; Sanchez Rodriguez, I E

    2017-05-08

    The inflammatory pseudotumour of the head and neck is a benign lesion, extremely rare outside the cranial orbits. A case is presented of an inflammatory pseudotumour not associated with the IgG4-related disease. The pseudotumour was found as a solitary mass in the infratemporal fossa of a young woman who complained of otalgia and hearing loss. A clear image of the lesion was obtained using an (18)F-fluoro-deoxy-glucose ((18)F-FDG) PET. After the histopathological diagnosis, and treatment with corticosteroids, a second (18)F-FDG PET was performed. The metabolic image had returned to normal, and the previously observed mass disappeared. A brief review is presented of the studies examining this type of lesion. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

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

    PubMed Central

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

    2017-01-01

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

  19. Combined Modality Treatment for PET-Positive Non-Hodgkin Lymphoma: Favorable Outcomes of Combined Modality Treatment for Patients With Non-Hodgkin Lymphoma and Positive Interim or Postchemotherapy FDG-PET

    SciTech Connect

    Halasz, Lia M.; Jacene, Heather A.; Catalano, Paul J.; Van den Abbeele, Annick D.; LaCasce, Ann; Mauch, Peter M.; Ng, Andrea K.

    2012-08-01

    Purpose: To evaluate outcomes of patients treated for aggressive non-Hodgkin lymphoma (NHL) with combined modality therapy based on [{sup 18}F]fluoro-2-deoxy-2-D-glucose positron emission tomography (FDG-PET) response. Methods and Materials: We studied 59 patients with aggressive NHL, who received chemotherapy and radiation therapy (RT) from 2001 to 2008. Among them, 83% of patients had stage I/II disease. Patients with B-cell lymphoma received R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone)-based chemotherapy, and 1 patient with anaplastic lymphoma kinase-negative anaplastic T-cell lymphoma received CHOP therapy. Interim and postchemotherapy FDG-PET or FDG-PET/computed tomography (CT) scans were performed for restaging. All patients received consolidated involved-field RT. Median RT dose was 36 Gy (range, 28.8-50 Gy). Progression-free survival (PFS) and local control (LC) rates were calculated with and without a negative interim or postchemotherapy FDG-PET scan. Results: Median follow-up was 46.5 months. Thirty-nine patients had negative FDG-PET results by the end of chemotherapy, including 12 patients who had a negative interim FDG-PET scan and no postchemotherapy PET. Twenty patients were FDG-PET-positive, including 7 patients with positive interim FDG-PET and no postchemotherapy FDG-PET scans. The 3-year actuarial PFS rates for patients with negative versus positive FDG-PET scans were 97% and 90%, respectively. The 3-year actuarial LC rates for patients with negative versus positive FDG-PET scans were 100% and 90%, respectively. Conclusions: Patients who had a positive interim or postchemotherapy FDG-PET had a PFS rate of 90% at 3 years after combined modality treatment, suggesting that a large proportion of these patients can be cured with consolidated RT.

  20. Systematic review of FDG-PET prediction of complete pathological response and survival in rectal cancer.

    PubMed

    Memon, Sameer; Lynch, A Craig; Akhurst, Timothy; Ngan, Samuel Y; Warrier, Satish K; Michael, Michael; Heriot, Alexander G

    2014-10-01

    Advances in the management of rectal cancer have resulted in an increased application of multimodal therapy with the aim of tailoring therapy to individual patients. Complete pathological response (pCR) is associated with improved survival and may be potentially managed without radical surgical resection. Over the last decade, there has been increasing interest in the ability of functional imaging to predict complete response to treatment. The aim of this review was to assess the role of (18)F-flurordeoxyglucose positron emission tomography (FDG-PET) in prediction of pCR and prognosis in resectable locally advanced rectal cancer. A search of the MEDLINE and Embase databases was conducted, and a systematic review of the literature investigating positron emission tomography (PET) in the prediction of pCR and survival in rectal cancer was performed. Seventeen series assessing PET prediction of pCR were included in the review. Seven series assessed postchemoradiation SUVmax, which was significantly different between response groups in all six studies that assessed this. Nine series assessed the response index (RI) for SUVmax, which was significantly different between response groups in seven series. Thirteen studies investigated PET response for prediction of survival. Metabolic complete response assessed by SUV2max or visual response and RISUVmax showed strong associations with disease-free survival (DFS) and overall survival (OS). SUV2max and RISUVmax appear to be useful FDG-PET markers for prediction of pCR and these parameters also show strong associations with DFS and OS. FDG-PET may have a role in outcome prediction in patients with advanced rectal cancer.

  1. Pigmented Villonodular Synovitis: Potential Pitfall on Oncologic 18F-FDG PET/CT.

    PubMed

    Broski, Stephen M; Murdoch, Nathan M; Skinner, John A; Wenger, Doris E

    2016-01-01

    This study evaluated the semiquantitative and qualitative appearance of pigmented villonodular synovitis (PVNS) and giant cell tumor of the tendon sheath (GCTTS) on 18F-FDG PET/CT. An institutional review board-approved retrospective review was performed for patients diagnosed with GCTTS, focal PVNS, or diffuse PVNS who underwent PET/CT from 2003 to 2013. SUVmax and SUVmax/SUVmean of the liver (SUVr) were determined for each lesion on all available PET/CTs. Relevant conventional imaging and patient records were reviewed. Fourteen patients (mean [SD] age, 52.8 [14.0] years; range, 26-74 years) were identified, 6 with 2 or more PET/CT examinations. The mean (SD) SUVmax and SUVr of all lesions were 8.7 (3.4; range, 4.0-14.5) and 3.9 (1.7; range, 2.0-7.1), respectively. There was no difference of the mean (SD) SUVmax (P = 0.10) or SUVr (P = 0.11) between focal PVNS (6.8 [3.0], 3.3 [1.9]), GCTTS (9.1 [3.0], 4.0 [1.2]), or diffuse PVNS (14.5, 7.1) subtypes. Of 29 comparison PET/CTs in 6 patients, 17 were performed after nontargeted chemotherapy and 12 without antecedent therapy. Significant SUVr fluctuations (>25%) occurred in 11 cases; no correlation existed between SUVr change and presence or absence of chemotherapy. Pigmented villonodular synovitis and GCTTS can be intensely hypermetabolic, mimicking musculoskeletal metastases on 18F-FDG PET/CT. They may have significant SUV fluctuations, both during nontargeted chemotherapy and between treatments. The diagnosis of PVNS/GCTTS should be considered for focal intra-articular or juxta-articular FDG-avid lesions, and MRI is useful in further evaluation given the often diagnostic imaging features with this modality.

  2. 18F-FDG PET/CT evaluation of children and young adults with suspected spinal fusion hardware infection.

    PubMed

    Bagrosky, Brian M; Hayes, Kari L; Koo, Phillip J; Fenton, Laura Z

    2013-08-01

    Evaluation of the child with spinal fusion hardware and concern for infection is challenging because of hardware artifact with standard imaging (CT and MRI) and difficult physical examination. Studies using (18)F-FDG PET/CT combine the benefit of functional imaging with anatomical localization. To discuss a case series of children and young adults with spinal fusion hardware and clinical concern for hardware infection. These people underwent FDG PET/CT imaging to determine the site of infection. We performed a retrospective review of whole-body FDG PET/CT scans at a tertiary children's hospital from December 2009 to January 2012 in children and young adults with spinal hardware and suspected hardware infection. The PET/CT scan findings were correlated with pertinent clinical information including laboratory values of inflammatory markers, postoperative notes and pathology results to evaluate the diagnostic accuracy of FDG PET/CT. An exempt status for this retrospective review was approved by the Institution Review Board. Twenty-five FDG PET/CT scans were performed in 20 patients. Spinal fusion hardware infection was confirmed surgically and pathologically in six patients. The most common FDG PET/CT finding in patients with hardware infection was increased FDG uptake in the soft tissue and bone immediately adjacent to the posterior spinal fusion rods at multiple contiguous vertebral levels. Noninfectious hardware complications were diagnosed in ten patients and proved surgically in four. Alternative sources of infection were diagnosed by FDG PET/CT in seven patients (five with pneumonia, one with pyonephrosis and one with superficial wound infections). FDG PET/CT is helpful in evaluation of children and young adults with concern for spinal hardware infection. Noninfectious hardware complications and alternative sources of infection, including pneumonia and pyonephrosis, can be diagnosed. FDG PET/CT should be the first-line cross-sectional imaging study in patients

  3. Dynamic FDG PET/CT imaging with diuresis demonstrates an enterovesical fistula in a lymphoma patient with repeated colon diverticulitis.

    PubMed

    Kao, Pan-Fu; Ting, Wen-Chien; Hsiao, Pei-Ching; Kao, Yu-Lin; Chang, Pai-Jung; Lee, Jong-Kang

    2013-04-01

    A 43-year-old male patient with follicular B-cell lymphoma was referred for a FDG PET/CT scan due to severe left lower abdominal pain to rule out recurrent cancer. These FDG PET/CT images and previous FDG PET/CT images 5 months ago both revealed an air bubble in the urinary bladder on the CT images. He had a recurrent urinary tract infection history for 6 months. A list-mode dynamic data acquisition with diuresis intravenous injection revealed linear FDG activity extending from the upper-left portion of the bladder to a soft tissue mass in the lower-left pelvic region. An enterovesical fistula was confirmed by surgery.

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

    PubMed

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

    2016-09-01

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

  5. (18)F-FDG PET/CT findings in a case with HIV (-) Kaposi sarcoma.

    PubMed

    Ozdemir, E; Poyraz, N Y; Keskin, M; Kandemir, Z; Turkolmez, S

    2014-01-01

    Although mucocutaneous sites are the most frequently encountered sites of involvement, Kaposi Sarcoma (KS) may also occasionally involve the breast and the skeletal, endocrine, urinary and nervous systems.. Various imaging modalities may be used to delineate the extent of the disease by detecting unexpected sites of involvement. Herein, we report a case of classical type KS, in whom staging with (18)F-FDG PET/CT imaging disclosed widespread disease and unexpected findings of bone and salivary gland involvement.

  6. "Bottle Brush Sign"-Spinal Meningeal Disease on 18F-FDG PET-CT Scan.

    PubMed

    Riaz, Saima; Naz, Fozia; Bashir, Humayun; Niazi, Imran Khalid

    2016-09-01

    A 30-year-old man with a history of stage IV AE diffuse large cell lymphoma of left proximal humerus presented with new onset lower limb weakness at completion of chemotherapy. The F-FDG PET-CT scan showed increased intraspinal uptake from T12 to S1 vertebrae with unique "bottle brush" appearance in keeping with spinal meningeal disease. The leptomeningeal disease was further confirmed on correlative MRI scan.

  7. Primary Pulmonary Artery Sarcoma on Dual-Time Point FDG PET/CT Imaging.

    PubMed

    Li, Juan; Zhao, Qian; He, Lirong; Zhuang, Xiaoqing; Li, Fang

    2016-08-01

    A 59-year-old man presented cough, chest pain, and shortness of breath for 2 weeks and fever for 4 days. A contrast chest CT revealed a large right pulmonary artery filling defect, suggestive of pulmonary embolism that failed to respond to anticoagulation therapy. FDG PET/CT was performed to evaluate possible malignancy, which revealed intense activity in the right main pulmonary artery without any extrathoracic abnormality. The ratio of the SUVmax of this lesion to the liver was significantly increased in the delayed PET images. The pathological examination demonstrated primary pulmonary artery sarcoma.

  8. Pulmonary Artery Sarcoma Detected on 18F-FDG PET/CT With Unusual Findings.

    PubMed

    Guo, Yuehong; Wang, Tie; Yang, Minfu

    2015-11-01

    A 32-year-old woman, who presented with "sharp pain" in the right chest for more than 1 month and worsening dyspnea and fever for 10 days, was initially thought to have a pulmonary embolism. Cardiac ultrasound showed an ill-defined echogenic mass within the pulmonary trunk. F-FDG PET/CT was performed for further evaluation. PET/CT showed an intense hypermetabolism in the main, bilateral proximal, and the right main pulmonary arteries, suggesting the presence of a malignant lesion. Biopsy confirmed the lesion as a primary pulmonary artery sarcoma.

  9. FDG PET/CT Demonstration of Pancreatic Metastasis from Prostate Cancer

    PubMed Central

    Desai, Bhushan; Elatre, Wafaa; Quinn, David I.; Jadvar, Hossein

    2011-01-01

    We report the hybrid FDG PET/CT appearance of a biopsy-proven pancreatic metastasis from prostate cancer in a man with castrate-resistant metastatic disease. The common sites of metastases from prostate cancer are bone and locoregional lymph nodes. Pancreas is an atypical location of metastasis from prostate cancer. PET/CT in this case helped with the targeted pathologic confirmation to differentiate primary pancreatic tumor from an unusual metastasis from prostate cancer which in turn impacted the clinical management. PMID:21892064

  10. A dual tracer (68)Ga-DOTANOC PET/CT and (18)F-FDG PET/CT pilot study for detection of cardiac sarcoidosis.

    PubMed

    Gormsen, Lars C; Haraldsen, Ate; Kramer, Stine; Dias, Andre H; Kim, Won Yong; Borghammer, Per

    2016-12-01

    Cardiac sarcoidosis (CS) is a potentially fatal condition lacking a single test with acceptable diagnostic accuracy. (18)F-FDG PET/CT has emerged as a promising imaging modality, but is challenged by physiological myocardial glucose uptake. An alternative tracer, (68)Ga-DOTANOC, binds to somatostatin receptors on inflammatory cells in sarcoid granulomas. We therefore aimed to conduct a proof-of-concept study using (68)Ga-DOTANOC to diagnose CS. In addition, we compared diagnostic accuracy and inter-observer variability of (68)Ga-DOTANOC vs. (18)F-FDG PET/CT. Nineteen patients (seven female) with suspected CS were prospectively recruited and dual tracer scanned within 7 days. PET images were reviewed by four expert readers for signs of CS and compared to the reference standard (Japanese ministry of Health and Welfare CS criteria). CS was diagnosed in 3/19 patients. By consensus, 11/19 (18)F-FDG scans and 0/19 (68)Ga-DOTANOC scans were rated as inconclusive. The sensitivity of (18)F-FDG PET for diagnosing CS was 33 %, specificity was 88 %, PPV was 33 %, NPV was 88 %, and diagnostic accuracy was 79 %. For (68)Ga-DOTANOC, accuracy was 100 %. Inter-observer agreement was poor for (18)F-FDG