Analog electro-optical readout of SiPMs for compact, low power ToF PET/MRI

International Nuclear Information System (INIS)

Bieniosek, Matthew F; Levin, Craig S

2014-01-01

The aim of this work is to demonstrate time of flight (ToF) performance from analog electro-optical transmission of SiPM-based PET detector signals. In electro-optical readout schemes, scintillation signals are converted to near-infrared light by a laser diode and transmitted out of the MRI bore with fiber-optics [], greatly reducing the PET system's footprint, power consumption, and mutual interference with the MRI.

Evaluation of endothelium-dependent myocardial perfusion reserve in healthy smokers; cold pressor test using H215O PET

International Nuclear Information System (INIS)

Hwang, Kyung Hoon; Lee, Dong Soo; Lee, Byeong Il; Lee, Jae Sung; Lee, Ho Young; Chung, June Key; Lee, Myung Chul

2004-01-01

Much evidence suggests long-term cigarette smoking alters coronary vascular endothelial response. In this study, we applied nonnegative matrix factorization (NMF), an unsupervised learning algorithm, to CO-less H 2 15 O-PET to investigate coronary endothelial dysfunction caused by smoking noninvasively. This study enrolled eighteen young male volunteers consisting of 9 smokers (23.8±1.1 yr; 6.6±2.5 pack-years) and 9 nonsmokers (23.8±2.9 yr). They do not have any cardiovascular risk factor or disease history. Myocardial H 2 15 O-PET was performed at rest, during cold (5.deg.C) pressor stimulation and during adenosine infusion. Left ventricular blood pool and myocardium were segmented on dynamic PET data by NMF method. Myocardial blood flow (MBF) was calculated from input and tissue functions by a single compartmental model with correction of partial volume and spillover effects. There were no significant difference in resting MBF between the two groups (Smokers: 1.43 0.41ml/g/min and non-smokers: 1.37±0.41 ml/g/min; p = NS). during cold pressor stimulation, MBF in smokers was significantly lower than that in non-smokers (1.25±0.34 ml/g/min vs 1.59±0.29 ml/g/min ; p = 0.019). The difference in the ratio of cold pressor MBF to resting MBF between the two groups was also significant (p=0.024; 90±24% in smokers and 122±28% in non-smokers.). During adenosine infusion, however, hyperemic MBF did not differ significantly between smokers and non-smokers (5.81±1.99 ml/g/min vs 5.11±1.31 ml/g/min ; p=NS). In smokers, MBF during cold pressor stimulation was significantly lower compared with nonsmokers, reflecting smoking-induced endothelial dysfunction. However, there was no significant difference in MBF during adenosine-induced hyperemia between the two groups

Markerless PET motion correction: tracking in narrow gantries through optical fibers

DEFF Research Database (Denmark)

Jensen, Rasmus Ramsbøl; Olesen, Oline Vinter; Benjaminsen, Claus

2015-01-01

be accurate while only adding minimal complexity to the workflow. We present: Tracoline 2.0, a surface scanner prototype, which allows for markerless tracking in the clinic. The system uses structured light through optical fibre bundles, which easily fit in narrow gantries. The optical fibres also makes...... the system compatible with magnetic resonance (MR) imaging since all the electronics are moved away from the scanner. We demonstrate the system in a positron emission tomography (PET) study using the Siemens high resolution research tomography (HRRT). With two Ge/Ga-68 line sources fitted in a mannequin head...... for rotations up to ±25º. Based on the tracking results the PET frames were also successfully corrected for motion by aligning 10 s frames without motion for the stepwise experiment and aligning 1 s frames for the experiment with continuous motion. We have demonstrated and evaluated a system for markerless...

Rational synthesis of high nuclearity Mo/Fe/S clusters: the reductive coupling approach in the convenient synthesis of (Cl(4)-cat)(2)Mo(2)Fe(6)S(8)(PR(3))(6) [R = Et, (n)Pr, (n)Bu] and the new [(Cl(4)-cat)(2)Mo(2)Fe(2)S(3)O(PEt(3))(3)Cl]-1/2(Fe(PEt(3))(2)(MeCN)(4)) and (Cl(4)-cat)(2)Mo(2)Fe(3)S(5)(PEt(3))(5) clusters.

Science.gov (United States)

Han, J; Koutmos, M; Ahmad, S A; Coucouvanis, D

2001-11-05

A general method for the synthesis of high nuclearity Mo/Fe/S clusters is presented and involves the reductive coupling of the (Et(4)N)(2)[(Cl(4)-cat)MoOFeS(2)Cl(2)] (I) and (Et(4)N)(2)[Fe(2)S(2)Cl(4)] (II) clusters. The reaction of I and II with Fe(PR(3))(2)Cl(2) or sodium salts of noncoordinating anions such as NaPF(6) or NaBPh(4) in the presence of PR(3) (R = Et, (n)Pr, or (n)Bu) affords (Cl(4)-cat)(2)Mo(2)Fe(6)S(8)(PR(3))(6) [R = Et (IIIa), (n)Pr (IIIb), (n)Bu (IIIc)], Fe(6)S(6)(PEt(3))(4)Cl(2) (IV) and (PF(6))[Fe(6)S(8)(P(n)Pr(3))(6)] (V) as byproducts. The isolation of (Et(4)N)[Fe(PEt(3))Cl(3)] (VI), NaCl, and SPEt(3) supports a reductive coupling mechanism. Cluster IV and V also have been synthesized by the reductive self-coupling of compound II. The reductive coupling reaction between I and II by PEt(3) and NaPF(6) in a 1:1 ratio produces the (Et(4)N)(2)[(Cl(4)-cat)Mo(L)Fe(3)S(4)Cl(3)] clusters [L = MeCN (VIIa), THF (VIIb)]. The hitherto unknown [(Cl(4)-cat)(2)Mo(2)Fe(2)S(3)O(PEt(3))(3)Cl](+) cluster (VIII) has been isolated as the 2:1 salt of the (Fe(PEt(3))(2)(MeCN)(4))(2+) cation after the reductive self-coupling reaction of I in the presence of Fe(PEt(3))(2)Cl(2). Cluster VIII crystallizes in the monoclinic space group P2(1)/c with a = 11.098(3) A, b = 22.827(6) A, c = 25.855(6) A, beta = 91.680(4) degrees, and Z = 4. The formal oxidation states of metal atoms in VIII have been assigned as Mo(III), Mo(IV), Fe(II), and Fe(III) on the basis of zero-field Mössbauer spectra. The Fe(PEt(3))(2)(MeCN)(4) cation of VIII is also synthesized independently, isolated as the BPh(4)(-) salt (IX), and has been structurally characterized. The reductive coupling of compound I also affords in low yield the new (Cl(4)-cat)(2)Mo(2)Fe(3)S(5)(PEt(3))(5) cluster (X) as a byproduct. Cluster X crystallizes in the monoclinic space group P2(1)/n with a = 14.811(3) A, b = 22.188(4) A, c = 21.864(4) A, beta = 100.124(3) degrees, and Z = 4 and the structure shows very short Mo

Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe

OpenAIRE

Zhu, Lei; Guo, Ning; Li, Quanzheng; Ma, Ying; Jacboson, Orit; Lee, Seulki; Choi, Hak Soo; Mansfield, James R.; Niu, Gang; Chen, Xiaoyuan

2012-01-01

Purpose: The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/64Cu dual-labeled cyclic RGD peptide. Methods: The integrin αvβ3 binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA)...

Radiation dose to radiosensitive organs in PET/CT myocardial perfusion examination using versatile optical fibre

Science.gov (United States)

Salasiah, M.; Nordin, A. J.; Fathinul Fikri, A. S.; Hishar, H.; Tamchek, N.; Taiman, K.; Ahmad Bazli, A. K.; Abdul-Rashid, H. A.; Mahdiraji, G. A.; Mizanur, R.; Noor, Noramaliza M.

2013-05-01

Cardiac positron emission tomography (PET) provides a precise method in order to diagnose obstructive coronary artery disease (CAD), compared to single photon emission tomography (SPECT). PET is suitable for obese and patients who underwent pharmacologic stress procedures. It has the ability to evaluate multivessel coronary artery disease by recording changes in left ventricular function from rest to peak stress and quantifying myocardial perfusion (in mL/min/g of tissue). However, the radiation dose to the radiosensitive organs has become crucial issues in the Positron Emission Tomography/Computed Tomography(PET/CT) scanning procedure. The objective of this study was to estimate radiation dose to radiosensitive organs of patients who underwent PET/CT myocardial perfusion examination at Centre for Diagnostic Nuclear Imaging, Universiti Putra Malaysia in one month period using versatile optical fibres (Ge-B-doped Flat Fibre) and LiF (TLD-100 chips). All stress and rest paired myocardial perfusion PET/CT scans will be performed with the use of Rubidium-82 (82Rb). The optic fibres were loaded into plastic capsules and attached to patient's eyes, thyroid and breasts prior to the infusion of 82Rb, to accommodate the ten cases for the rest and stress PET scans. The results were compared with established thermoluminescence material, TLD-100 chips. The result shows that radiation dose given by TLD-100 and Germanium-Boron-doped Flat Fiber (Ge-B-doped Flat Fiber) for these five organs were comparable to each other where the p>0.05. For CT scans,thyroid received the highest dose compared to other organs. Meanwhile, for PET scans, breasts received the highest dose.

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

International Nuclear Information System (INIS)

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

2015-01-01

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 mm 3 were used instead of 2.47 × 2.74 × 20.0 mm 3 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 B 0 and B 1 field homogeneity without PET, with 'PET OFF', and with 'PET ON' was also evaluated. In conclusion, B 0 maps were not affected by the proposed PET insert whereas B 1 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

Preserved benzodiazepine receptors in Alzheimer's disease measured with C-11 flumazenil PET and I-123 iomazenil SPECT in comparison with CBF

International Nuclear Information System (INIS)

Ohyama, Masashi; Kitamura, Shin; Mishina, Masahiro; Katayama, Yasuo; Senda, Michio; Ishiwata, Kiichi; Ishii, Kenji; Toyama, Hinako; Oda, Keiichi

1999-01-01

This study evaluates the regional cerebral blood flow (CBF) with H 2 15 O-PET and the distribution of central benzodiazepine receptor (BZR) with C-11 flumazenil (FMZ) by PET and I-123 iomazenil (IMZ) by SPECT in Alzheimer's disease (AD). In AD, whereas the CBF was diminished in the frontal, temporal, parietal, and occipital cortex, the distribution volume of FMZ and delayed activity of IMZ were relatively preserved in these cortices, suggesting that the BZR reduction, reflecting neuronal loss, is less prominent than the CBF suppression. The mini-mental state examination score (MMS) was weakly correlated with the CBF in the parietal cortex but not with BZR. It is speculated that the neuronal density reflected by BZR is less impaired than the neuronal function assessed with blood flow in the association cortex of AD. High correlation was found between the uptake of FMZ and the delayed activity of IMZ. The delayed image of IMZ-SPECT is clinically useful to evaluate the preservation of neuronal density in the affected temoporoparietal association cortex in AD. (author)

DMAP-BODIPY alkynes: a convenient tool for labeling biomolecules for bimodal PET-optical imaging.

Science.gov (United States)

Brizet, Bertrand; Goncalves, Victor; Bernhard, Claire; Harvey, Pierre D; Denat, Franck; Goze, Christine

2014-09-26

Several new boron dipyrromethene/N,N-dimethylaminopyridine (BODIPY-DMAP) assemblies were synthesized as precursors for bimodal imaging probes (optical imaging, OI/positron emission tomography, PET). The photophysical properties of the new compounds were also studied. The first proof-of-concept was obtained with the preparation of several new BODIPY-labeled bombesins and evaluation of the affinity for bombesin receptors by using a competition binding assay. Fluorination reactions were investigated on DMAP-BODIPY precursors as well as on DMAP-BODIPY-labeled bombesins. Chemical modifications on the BODIPY core were also performed to obtain luminescent dyes emitting in the therapeutic window (650-900 nm), suitable for in vivo imaging, making these compounds promising precursors for PET/optical dual-modality imaging agents. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The role of language areas in motor control dysfunction in Parkinson's disease

NARCIS (Netherlands)

Albani, G; Kunig, G; Soelch, CM; Mauro, A; Priano, L; Martignoni, E; Leenders, K.L.

We evaluated the differences in motor control organization between parkinsonian patients with (seven cases) and without(ten cases) gait disorder. We used positron emission tomography (O-15-H2O-PET) to measure regional cerebral blood flow as a correlate for local neuronal activation. This has been

Simultaneous acquisition of multislice PET and MR images: initial results with a MR-compatible PET scanner.

Science.gov (United States)

Catana, Ciprian; Wu, Yibao; Judenhofer, Martin S; Qi, Jinyi; Pichler, Bernd J; Cherry, Simon R

2006-12-01

PET and MRI are powerful imaging techniques that are largely complementary in the information they provide. We have designed and built a MR-compatible PET scanner based on avalanche photodiode technology that allows simultaneous acquisition of PET and MR images in small animals. The PET scanner insert uses magnetic field-insensitive, position-sensitive avalanche photodiode (PSAPD) detectors coupled, via short lengths of optical fibers, to arrays of lutetium oxyorthosilicate (LSO) scintillator crystals. The optical fibers are used to minimize electromagnetic interference between the radiofrequency and gradient coils and the PET detector system. The PET detector module components and the complete PET insert assembly are described. PET data were acquired with and without MR sequences running, and detector flood histograms were compared with the ones generated from the data acquired outside the magnet. A uniform MR phantom was also imaged to assess the effect of the PET detector on the MR data acquisition. Simultaneous PET and MRI studies of a mouse were performed ex vivo. PSAPDs can be successfully used to read out large numbers of scintillator crystals coupled through optical fibers with acceptable performance in terms of energy and timing resolution and crystal identification. The PSAPD-LSO detector performs well in the 7-T magnet, and no visible artifacts are detected in the MR images using standard pulse sequences. The first images from the complete system have been successfully acquired and reconstructed, demonstrating that simultaneous PET and MRI studies are feasible and opening up interesting possibilities for dual-modality molecular imaging studies.

A novel optically transparent RF shielding for fully integrated PET/MRI systems

Science.gov (United States)

Parl, C.; Kolb, A.; Schmid, A. M.; Wehrl, H. F.; Disselhorst, J. A.; Soubiran, P. D.; Stricker-Shaver, D.; Pichler, B. J.

2017-09-01

Preclinical imaging benefits from simultaneous acquisition of high-resolution anatomical and molecular data. Additionally, PET/MRI systems can provide functional PET and functional MRI data. To optimize PET sensitivity, we propose a system design that fully integrates the MRI coil into the PET system. This allows positioning the scintillators near the object but requires an optimized design of the MRI coil and PET detector. It further requires a new approach in realizing the radiofrequency (RF) shielding. Thus, we propose the use of an optically transparent RF shielding material between the PET scintillator and the light sensor, suppressing the interference between both systems. We evaluated two conductive foils (ITO, 9900) and a wire mesh. The PET performance was tested on a dual-layer scintillator consisting of 12  ×  12 LSO matrices, shifted by half a pitch. The pixel size was 0.9  ×  0.9 mm2 the lengths were 10.0 mm and 5.0 mm, respectively. For a light sensor, we used a 4  ×  4 SiPM array. The RF attenuation was measured from 320 kHz to 420 MHz using two pick-up coils. MRI-compatibility and shielding effect of the materials were evaluated with an MRI system. The average FWHM energy resolution at 511 keV of all 144 crystals of the layer next to the SiPM was deteriorated from 15.73  ±  0.24% to 16.32  ±  0.13%, 16.60  ±  0.25%, and 19.16  ±  0.21% by the ITO foil, 9900 foil, mesh material, respectively. The average peak-to-valley ratio of the PET detector changed from 5.77  ±  0.29 to 4.50  ±  0.39, 4.78  ±  0.48, 3.62  ±  0.16, respectively. The ITO, 9900, mesh attenuated the scintillation light by 11.3  ±  1.6%, 11.0  ±  1.8%, 54.3  ±  0.4%, respectively. To attenuate the RF from 20 MHz to 200 MHz, mesh performed better than copper. The results show that an RF shielding material that is sufficiently transparent for

Simultaneous PET and MR imaging

International Nuclear Information System (INIS)

Yiping Shao; Cherry, Simon R.; Meadors, Ken; Siegel, Stefan; Silverman, Robert W.; Farahani, Keyvan; Marsden, Paul K.

1997-01-01

We have developed a prototype PET detector which is compatible with a clinical MRI system to provide simultaneous PET and MR imaging. This single-slice PET system consists of 48 2x2x10mm 3 LSO crystals in a 38 mm diameter ring configuration that can be placed inside the receiver coil of the MRI system, coupled to three multi-channel photomultipliers housed outside the main magnetic field via 4 m long and 2 mm diameter optical fibres. The PET system exhibits 2 mm spatial resolution, 41% energy resolution at 511 keV and 20 ns timing resolution. Simultaneous PET and MR phantom images were successfully acquired. (author)

qPET - a quantitative extension of the Deauville scale to assess response in interim FDG-PET scans in lymphoma

Energy Technology Data Exchange (ETDEWEB)

Hasenclever, Dirk [University of Leipzig, Institute for Medical Informatics, Statistics and Epidemiology (IMISE), Leipzig (Germany); Kurch, Lars; Georgi, Thomas; Sabri, Osama; Kluge, Regine [University Hospital Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Mauz-Koerholz, Christine; Koerholz, Dieter [University Hospital Halle, Department of Pediatrics, Halle (Germany); Elsner, Andreas [Hermes Medical Solutions AB, Stockholm (Sweden); Wallace, Hamish [Royal Hospital for Sick Children, Edinburgh, Scotland (United Kingdom); Landman-Parker, Judith [Hopital d' Enfants Armand Trousseau, Paris (France); Moryl-Bujakowska, Angelina [Jagiellonian University Medical College, Department of Pediatric Oncology and Hematology, Polish-American Institute of Pediatrics, Krakow (Poland); Cepelova, Michaela [Department of Pediatric Hematology and Oncology, Faculty Hospital Motol, Prague (Czech Republic); Karlen, Jonas [Karolinska University Hospital, Pediatric Cancer Unit, Astrid Lindgrens Childrens Hospital, Stockholm (Sweden); Alvarez Fernandez-Teijeiro, Ana [University Hospital Virgen Macarena Avda, Department of Pediatric Oncology and Hematology, Sevilla (Spain); Attarbaschi, Andishe [Medical University of Vienna, Department of Pediatric Hematology and Oncology, St. Anna Children' s Hospital, Vienna (Austria); Fossaa, Alexander [Department of Medical Oncology and Radiotherapy, Rikshospitalet - Radiumhospitalet HF, Oslo (Norway); Pears, Jane [Our Lady' s Children' s Hospital, Crumlin, Dublin (Ireland); Hraskova, Andrea [University Children' s Hospital, Clinic of Pediatric Oncology, Bratislava (Slovakia); Bergstraesser, Eva [University Children' s Hospital, Department Oncology, Zurich (Switzerland); Beishuizen, Auke [MC - Sophia Children' s Hospital, Department of Pediatric Oncology/Hematology, Rotterdam (Netherlands); Uyttebroeck, Anne [University Hospitals of Leuven, Department of Pediatric Hemato-Oncology, Leuven (Belgium); Schomerus, Eckhard [University of Odense (OUH), Department of Pediatric Oncology and Hematology, H. C. Andersen Children' s Hospital, Odense (Denmark)

2014-07-15

Interim FDG-PET is used for treatment tailoring in lymphoma. Deauville response criteria consist of five ordinal categories based on visual comparison of residual tumor uptake to physiological reference uptakes. However, PET-response is a continuum and visual assessments can be distorted by optical illusions. With a novel semi-automatic quantification tool we eliminate optical illusions and extend the Deauville score to a continuous scale. SUV{sub peak} of residual tumors and average uptake of the liver is measured with standardized volumes of interest. The qPET value is the quotient of these measurements. Deauville scores and qPET-values were determined in 898 pediatric Hodgkin's lymphoma patients after two OEPA chemotherapy cycles. Deauville categories translate to thresholds on the qPET scale: Categories 3, 4, 5 correspond to qPET values of 0.95, 1.3 and 2.0, respectively. The distribution of qPET values is unimodal with a peak representing metabolically normal responses and a tail of clearly abnormal outliers. In our patients, the peak is at qPET = 0.95 coinciding with the border between Deauville 2 and 3. qPET cut values of 1.3 or 2 (determined by fitting mixture models) select abnormal metabolic responses with high sensitivity, respectively, specificity. qPET methodology provides semi-automatic quantification for interim FDG-PET response in lymphoma extending ordinal Deauville scoring to a continuous scale. Deauville categories correspond to certain qPET cut values. Thresholds between normal and abnormal response can be derived from the qPET-distribution without need for follow-up data. In our patients, qPET < 1.3 excludes abnormal response with high sensitivity. (orig.)

qPET - a quantitative extension of the Deauville scale to assess response in interim FDG-PET scans in lymphoma

International Nuclear Information System (INIS)

Hasenclever, Dirk; Kurch, Lars; Georgi, Thomas; Sabri, Osama; Kluge, Regine; Mauz-Koerholz, Christine; Koerholz, Dieter; Elsner, Andreas; Wallace, Hamish; Landman-Parker, Judith; Moryl-Bujakowska, Angelina; Cepelova, Michaela; Karlen, Jonas; Alvarez Fernandez-Teijeiro, Ana; Attarbaschi, Andishe; Fossaa, Alexander; Pears, Jane; Hraskova, Andrea; Bergstraesser, Eva; Beishuizen, Auke; Uyttebroeck, Anne; Schomerus, Eckhard

2014-01-01

Interim FDG-PET is used for treatment tailoring in lymphoma. Deauville response criteria consist of five ordinal categories based on visual comparison of residual tumor uptake to physiological reference uptakes. However, PET-response is a continuum and visual assessments can be distorted by optical illusions. With a novel semi-automatic quantification tool we eliminate optical illusions and extend the Deauville score to a continuous scale. SUV peak of residual tumors and average uptake of the liver is measured with standardized volumes of interest. The qPET value is the quotient of these measurements. Deauville scores and qPET-values were determined in 898 pediatric Hodgkin's lymphoma patients after two OEPA chemotherapy cycles. Deauville categories translate to thresholds on the qPET scale: Categories 3, 4, 5 correspond to qPET values of 0.95, 1.3 and 2.0, respectively. The distribution of qPET values is unimodal with a peak representing metabolically normal responses and a tail of clearly abnormal outliers. In our patients, the peak is at qPET = 0.95 coinciding with the border between Deauville 2 and 3. qPET cut values of 1.3 or 2 (determined by fitting mixture models) select abnormal metabolic responses with high sensitivity, respectively, specificity. qPET methodology provides semi-automatic quantification for interim FDG-PET response in lymphoma extending ordinal Deauville scoring to a continuous scale. Deauville categories correspond to certain qPET cut values. Thresholds between normal and abnormal response can be derived from the qPET-distribution without need for follow-up data. In our patients, qPET < 1.3 excludes abnormal response with high sensitivity. (orig.)

STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF PET POLYMER FILMS MODIFIED BY LOW ENERGY Ar+ ION BEAMS

Science.gov (United States)

Fawzy, Y. H. A.; Abdel-Hamid, H. M.; El-Okr, M. M.; Atta, A.

Polyethylene terephthalate (PET) films with thickness 40μm are irradiated with 3keV argon ion beams with different fluence ranging from 0.5×1018ions.cm-2 to 2×1018ions.cm-2 using locally designed broad ion source. The changes in the PET structure are characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscope (SEM) techniques. The XRD patterns show that the peak intensity decreases with irradiation and the particle size decreases from 65.75 Å for the un-irradiated to 52.80 Å after irradiation. The FTIR indicates partial decrease and reduction in the intensity of the bands due to the degradation of the polymer after ion irradiation. The optical energy band gap decreases from 3.14eV to 3.05eV and the number of carbon cluster increases from 119 to 126 after ion irradiation. The results show a slight increase in the electrical conductivities and the dielectric constant (ɛ). The results indicate the effectiveness of using PET films as capacitors and resistors in industrial applications.

Indium-tin oxide thin films deposited at room temperature on glass and PET substrates: Optical and electrical properties variation with the H2-Ar sputtering gas mixture

Science.gov (United States)

Álvarez-Fraga, L.; Jiménez-Villacorta, F.; Sánchez-Marcos, J.; de Andrés, A.; Prieto, C.

2015-07-01

The optical and electrical properties of indium tin oxide (ITO) films deposited at room temperature on glass and polyethylene terephthalate (PET) substrates were investigated. A clear evolution of optical transparency and sheet resistance with the content of H2 in the gas mixture of H2 and Ar during magnetron sputtering deposition is observed. An optimized performance of the transparent conductive properties ITO films on PET was achieved for samples prepared using H2/(Ar + H2) ratio in the range of 0.3-0.6%. Moreover, flexible ITO-PET samples show a better transparent conductive figure of merit, ΦTC = T10/RS, than their glass counterparts. These results provide valuable insight into the room temperature fabrication and development of transparent conductive ITO-based flexible devices.

Indium-tin oxide thin films deposited at room temperature on glass and PET substrates: Optical and electrical properties variation with the H2–Ar sputtering gas mixture

International Nuclear Information System (INIS)

Álvarez-Fraga, L.; Jiménez-Villacorta, F.; Sánchez-Marcos, J.; Andrés, A. de; Prieto, C.

2015-01-01

Highlights: • ITO deposition on glass and PET at room temperature by using H. • High transparency and low resistance is obtained by tuning the H. • The figure of merit for ITO films on PET becomes maximal for thickness near 100 nm. - Abstract: The optical and electrical properties of indium tin oxide (ITO) films deposited at room temperature on glass and polyethylene terephthalate (PET) substrates were investigated. A clear evolution of optical transparency and sheet resistance with the content of H 2 in the gas mixture of H 2 and Ar during magnetron sputtering deposition is observed. An optimized performance of the transparent conductive properties ITO films on PET was achieved for samples prepared using H 2 /(Ar + H 2 ) ratio in the range of 0.3–0.6%. Moreover, flexible ITO-PET samples show a better transparent conductive figure of merit, Φ TC = T 10 /R S , than their glass counterparts. These results provide valuable insight into the room temperature fabrication and development of transparent conductive ITO-based flexible devices

Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

Energy Technology Data Exchange (ETDEWEB)

Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

2004-05-01

Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

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

Science.gov (United States)

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

2014-11-01

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

Pathophysiological aspects of malignant brain tumors studied with positron emission tomography

International Nuclear Information System (INIS)

Jarden, J.O.

1994-01-01

To further understand the control of brain tumor fluid balance and pH, the following studies were undertaken. The transport of a water soluble molecule across the brain and tumor capillary endothelium was studied during glucocorticoid and radiation treatment. The brain and brain-tumor acidity (pH) was evaluated as a single measurement in patients receiving a low maintenance dose of glucocorticoid. Transport changes and pH were measured in 61 patients with cerebral tumors using 82 Rubidium ( 82 Rb) and 11 C-Dimethyloxa-zolidindione ( 11 C-DMO), respectively, and Positron Emission Tomography (PET). Supplementary studies of tumor and contralateral brain blood flow and blood volume using the C 15 O 2 /PET and C 15 O/PET technique, respectively, were included to validate the 82 Rb/PET model and obtain further information. A total of 125 PET scans were performed. Supplementary studies were undertaken to estimate delay of blood registration and form distribution of arterial blood isotope activity curves. Blood-to-tumor barrier transport was outlined at baseline and at 6 and 24 hours after the start of glucocorticoid treatment, finding a significant decrease in the transpfort. Radiation treatment (2-6 gray) did not alter the blood-to-tumor barrier transport when restudied within one hour in patients receiving glucocorticoid. The pH in brain tumors was as high as 6.88-7.26, suggesting that tumors are more alkalotic than the normal brain. The permeability surface area product and the permeability coefficient were determined form the 82 Rb/PET transport and C 15 O 2 /PET flow studies. Baseline permeability values were comparable to the literature values both for 82 Rb and potassium. No difference in tissue blood volume was seen between 82 Rb/PET and C 15 O/PET models and was of the same magnitude in the tumor and the contralateral tissue. Aspects of tumor alkalosis, tumor edema production, glucocorticoid edema clearance, and relationship between the anti-edema effect of

Detection of misery perfusion in the cerebral hemisphere with chronic unilateral major cerebral artery steno-occlusive disease using crossed cerebellar hypoperfusion: comparison of brain SPECT and PET imaging

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Yoshiyasu; Ogasawara, Kuniaki; Saito, Hideo; Takahashi, Yoshihiro; Ogasawara, Yasushi; Kobayashi, Masakazu; Ogawa, Akira [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Terasaki, Kazunori [Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Yoshida, Kenji; Beppu, Takaaki; Kubo, Yoshitaka; Fujiwara, Shunrou [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Tsushima, Eiki [Hirosaki University, Graduate School of Health Sciences, Hirosaki (Japan)

2013-10-15

In patients with unilateral internal carotid or middle cerebral artery (ICA or MCA) occlusive disease, the degree of crossed cerebellar hypoperfusion that is evident within a few months after the onset of stroke may reflect cerebral metabolic rate of oxygen in the affected cerebral hemisphere relative to that in the contralateral cerebral hemisphere. The aim of the present study was to determine whether the ratio of blood flow asymmetry in the cerebellar hemisphere to blood flow asymmetry in the cerebral hemisphere on positron emission tomography (PET) and single photon emission computed tomography (SPECT) correlates with oxygen extraction fraction (OEF) asymmetry in the cerebral hemisphere on PET in patients with chronic unilateral ICA or MCA occlusive disease and whether this blood flow ratio on SPECT detects misery perfusion in the affected cerebral hemisphere in such patients. Brain blood flow and OEF were assessed using {sup 15}O-PET and N-isopropyl-p-[{sup 123}I]iodoamphetamine ({sup 123}I-IMP) SPECT, respectively. All images were anatomically standardized using SPM2. A region of interest (ROI) was automatically placed in the bilateral MCA territories and in the bilateral cerebellar hemispheres using a three-dimensional stereotaxic ROI template, and affected-to-contralateral asymmetry in the MCA territory or contralateral-to-affected asymmetry in the cerebellar hemisphere was calculated. Sixty-three patients with reduced blood flow in the affected cerebral hemisphere on {sup 123}I-IMP SPECT were enrolled in this study. A significant correlation was observed between MCA ROI asymmetry of PET OEF and the ratio of cerebellar hemisphere asymmetry of blood flow to MCA ROI asymmetry of blood flow on PET (r = 0.381, p = 0.0019) or SPECT (r = 0.459, p = 0.0001). The correlation coefficient was higher when reanalyzed in a subgroup of 43 patients undergoing a PET study within 3 months after the last ischemic event (r = 0.541, p = 0.0001 for PET; r = 0.609, p < 0

A study of artefacts in simultaneous PET and MR imaging using a prototype MR compatible PET scanner

International Nuclear Information System (INIS)

Slates, R.B.; Farahani, K.; Marsden, P.K.; Taylor, J.; Summers, P.E.; Williams, S.; Beech, J.

1999-01-01

We have assessed the possibility of artefacts that can arise in attempting to perform simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) using a small prototype MR compatible PET scanner (McPET). In these experiments, we examine MR images for any major artefacts or loss in image quality due to inhomogeneities in the magnetic field, radiofrequency interference or susceptibility effects caused by operation of the PET system inside the MR scanner. In addition, possible artefacts in the PET images caused by the static and time-varying magnetic fields or radiofrequency interference from the MR system were investigated. Biological tissue and a T 2 -weighted spin echo sequence were used to examine susceptibility artefacts due to components of the McPET scanner (scintillator, optical fibres) situated in the MR field of view. A range of commonly used MR pulse sequences was studied while acquiring PET data to look for possible artefacts in either the PET or MR images. Other than a small loss in signal-to-noise using gradient echo sequences, there was no significant interaction between the two imaging systems. Simultaneous PET and MR imaging of simple phantoms was also carried out in different MR systems with field strengths ranging from 0.2 to 4.7 T. The results of these studies demonstrate that it is possible to acquire PET and MR images simultaneously, without any significant artefacts or loss in image quality, using our prototype MR compatible PET scanner. (author)

Approach to ''Mind'' using functional neuroimaging

International Nuclear Information System (INIS)

Matsuda, Hiroshi

2006-01-01

This review mainly describes authors' recent investigations concerning neuroimages approaching to even human ''mind'' using techniques of PET, SPECT and functional MRI (fMRI). Progress of such studies greatly owes to the development of image statistics of the brain like statistical parametric mapping (www.fil.ion.ucl.ac.uk/spm/), and brain standards (www.mrc-cbu.cam.ac.uk/Imaging/mnispace.html, and ric.uthscsa.edu/projects/talairach daemon.html). The author discusses and presents images in cases of hallucinations (SPECT and H 2 15 O-PET), autism (SPECT), sleep, depression, and its therapy by transcaranial magnetic stimulation. These studies are expected to contribute to diagnosis and therapy of endogenous neurological disorders. (T.I.)

Approach to ''Mind'' using functional neuroimaging

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Hiroshi [Saitama Medical School, Hospital, Moroyama, Saitama (Japan)

2006-05-15

This review mainly describes authors' recent investigations concerning neuroimages approaching to even human ''mind'' using techniques of PET, SPECT and functional MRI (fMRI). Progress of such studies greatly owes to the development of image statistics of the brain like statistical parametric mapping (www.fil.ion.ucl.ac.uk/spm/), and brain standards (www.mrc-cbu.cam.ac.uk/Imaging/mnispace.html, and ric.uthscsa.edu/projects/talairach daemon.html). The author discusses and presents images in cases of hallucinations (SPECT and H{sub 2}{sup 15}O-PET), autism (SPECT), sleep, depression, and its therapy by transcaranial magnetic stimulation. These studies are expected to contribute to diagnosis and therapy of endogenous neurological disorders. (T.I.)

Radiolabeled Peptide Scaffolds for PET/SPECT - Optical in Vivo Imaging of Carbohydrate-Lectin Interactions

Energy Technology Data Exchange (ETDEWEB)

Deutscher, Susan

2014-09-30

The objective of this research is to develop phage display-selected peptides into radio- and fluoresecently- labeled scaffolds for the multimodal imaging of carbohydrate-lectin interactions. While numerous protein and receptor systems are being explored for the development of targeted imaging agents, the targeting and analysis of carbohydrate-lectin complexes in vivo remains relatively unexplored. Antibodies, nanoparticles, and peptides are being developed that target carbohydrate-lectin complexes in living systems. However, antibodies and nanoparticles often suffer from slow clearance and toxicity problems. Peptides are attractive alternative vehicles for the specific delivery of radionuclides or fluorophores to sites of interest in vivo, although, because of their size, uptake and retention may be less than antibodies. We have selected high affinity peptides that bind a specific carbohydrate-lectin complex involved in cell-cell adhesion and cross-linking using bacteriophage (phage) display technologies (1,2). These peptides have allowed us to probe the role of these antigens in cell adhesion. Fluorescent versions of the peptides have been developed for optical imaging and radiolabeled versions have been used in single photon emission computed tomography (SPECT) and positron emission tomography (PET) in vivo imaging (3-6). A benefit in employing the radiolabeled peptides in SPECT and PET is that these imaging modalities are widely used in living systems and offer deep tissue sensitivity. Radiolabeled peptides, however, often exhibit poor stability and high kidney uptake in vivo. Conversely, optical imaging is sensitive and offers good spatial resolution, but is not useful for deep tissue penetration and is semi-quantitative. Thus, multimodality imaging that relies on the strengths of both radio- and optical- imaging is a current focus for development of new in vivo imaging agents. We propose a novel means to improve the efficacy of radiolabeled and fluorescently

Motion compensation for fully 4D PET reconstruction using PET superset data

Energy Technology Data Exchange (ETDEWEB)

Verhaeghe, J; Gravel, P; Mio, R; Fukasawa, R; Rosa-Neto, P; Soucy, J-P; Thompson, C J; Reader, A J, E-mail: jeroen.verhaeghe@mcgill.c [Montreal Neurological Institute, McGill University, Montreal (Canada)

2010-07-21

Fully 4D PET image reconstruction is receiving increasing research interest due to its ability to significantly reduce spatiotemporal noise in dynamic PET imaging. However, thus far in the literature, the important issue of correcting for subject head motion has not been considered. Specifically, as a direct consequence of using temporally extensive basis functions, a single instance of movement propagates to impair the reconstruction of multiple time frames, even if no further movement occurs in those frames. Existing 3D motion compensation strategies have not yet been adapted to 4D reconstruction, and as such the benefits of 4D algorithms have not yet been reaped in a clinical setting where head movement undoubtedly occurs. This work addresses this need, developing a motion compensation method suitable for fully 4D reconstruction methods which exploits an optical tracking system to measure the head motion along with PET superset data to store the motion compensated data. List-mode events are histogrammed as PET superset data according to the measured motion, and a specially devised normalization scheme for motion compensated reconstruction from the superset data is required. This work proceeds to propose the corresponding time-dependent normalization modifications which are required for a major class of fully 4D image reconstruction algorithms (those which use linear combinations of temporal basis functions). Using realistically simulated as well as real high-resolution PET data from the HRRT, we demonstrate both the detrimental impact of subject head motion in fully 4D PET reconstruction and the efficacy of our proposed modifications to 4D algorithms. Benefits are shown both for the individual PET image frames as well as for parametric images of tracer uptake and volume of distribution for {sup 18}F-FDG obtained from Patlak analysis.

Deep brain stimulation of nucleus accumbens region in alcoholism affects reward processing.

Science.gov (United States)

Heldmann, Marcus; Berding, Georg; Voges, Jürgen; Bogerts, Bernhard; Galazky, Imke; Müller, Ulf; Baillot, Gunther; Heinze, Hans-Jochen; Münte, Thomas F

2012-01-01

The influence of bilateral deep brain stimulation (DBS) of the nucleus nucleus (NAcc) on the processing of reward in a gambling paradigm was investigated using H(2)[(15)O]-PET (positron emission tomography) in a 38-year-old man treated for severe alcohol addiction. Behavioral data analysis revealed a less risky, more careful choice behavior under active DBS compared to DBS switched off. PET showed win- and loss-related activations in the paracingulate cortex, temporal poles, precuneus and hippocampus under active DBS, brain areas that have been implicated in action monitoring and behavioral control. Except for the temporal pole these activations were not seen when DBS was deactivated. These findings suggest that DBS of the NAcc may act partially by improving behavioral control.

Preliminary results of a prototype C-shaped PET designed for an in-beam PET system

International Nuclear Information System (INIS)

Kim, Hyun-Il; Chung, Yong Hyun; Lee, Kisung; Kim, Kyeong Min; Kim, Yongkwon; Joung, Jinhun

2016-01-01

Positron emission tomography (PET) can be utilized in particle beam therapy to verify the dose distribution of the target volume as well as the accuracy of the treatment. We present an in-beam PET scanner that can be integrated into a particle beam therapy system. The proposed PET scanner consisted of 14 detector modules arranged in a C-shape to avoid blockage of the particle beam line by the detector modules. Each detector module was composed of a 9×9 array of 4.0 mm×4.0 mm×20.0 mm LYSO crystals optically coupled to four 29-mm-diameter PMTs using the photomultiplier-quadrant-sharing (PQS) technique. In this study, a Geant4 Application for Tomographic Emission (GATE) simulation study was conducted to design a C-shaped PET scanner and then experimental evaluation of the proposed design was performed. The spatial resolution and sensitivity were measured according to NEMA NU2-2007 standards and were 6.1 mm and 5.61 cps/kBq, respectively, which is in good agreement with our simulation, with an error rate of 12.0%. Taken together, our results demonstrate the feasibility of the proposed C-shaped in-beam PET system, which we expect will be useful for measuring dose distribution in particle therapy.

Difference of cerebral activation between healthy volunteers and MCI-patients during navigation in a virtual reality environment. A parametric study using O15 H2O-PET

International Nuclear Information System (INIS)

Drzezga, A.; Wermke, M.D.; Schwaiger, M.; Grimmer, T.; Foerstl, H.; Kurz, A.

2002-01-01

Aim: To assess the regional cerebral activation during navigation in a virtual reality (VR) environment in healthy volunteers and patients with mild cognitive impairment (MCI) to identify possible differences in cerebral processing of a complex cognitive task. Materials and Methods: A computer-based VR-system has been developed that allows movements in a virtual labyrinth using a special space-mouse and 3-dimensional perception by shutter-glasses. In 11 healthy, right-handed volunteers (3 female, age 66+/-9 years) and 9 patients with MCI (3 female, 69+/-10 years, diagnosis according to criteria of the Mayo-Clinic) twelve H215O PET-scans were performed (each 370 MBq i.v.-bolus). During the scan subjects had to navigate actively from startpoint to a predefined destination point. Three difficulty levels were presented, 4 times each, in randomized order. Test performance (speed, mistakes) was co-registered. PET data were analyzed using statistical parametric mapping (SPM99, Wellcome Inst., London, UK) including correlation analysis with the acquired test performance results. A significance threshold of p<0,001 uncorrected was applied. Results: In both groups a similar network of extended cerebral activation was identified during active navigation, including maxima in the cerebellum, premotor cortex (Brodmann area [BA] 6), parietal cortex (BA 7, 40) and posterior cingulate cortex (BA 31). However, in MCI-patients a significantly stronger activation of anterior cingulate cortex (BA 24), prefrontal cortex (BA 8) and parietal cortex (BA 40) was observed, as compared to healthy volunteers. Conclusion: The applied combination of PET and VR-technology allows to examine the processing of complex cognitive tasks in the brain. During active navigation significant differences have been observed between the activated cerebral networks in MCI-patients and healthy volunteers. In MCI-patients stronger activation has been identified in cerebral regions associated with attention and

64Cu radiolabeled nano-materials as bimodal contrast agent for optical imaging and Positron Emission Tomography (PET)

International Nuclear Information System (INIS)

Nonat, A.M.; Roux, A.; Yahia-Ammar, A.; Charbonniere, L.J.; Platas-Iglesias, C.; Camerle, F.

2015-01-01

Fluorescent nano-crystals made of semiconductor material, also called Quantum Dots, are ideal agents for long-term or real-time optical imaging. They have been found to outperform traditional organic fluorescent dyes in many ways (size-tunable optical properties, high quantum yields, high extinction coefficients, resistance to photo bleaching). We have developed a microwave method for the synthesis of highly luminescent water soluble CdTe x S 1-x nano-crystals (Φ= 53% at 600 nm). Their surface functionalization has been developed and controlled using a Nile-Red derivative as a fluorescent marker. The same coupling strategy will be used to incorporate 64 Cu-radiotracers for PET imaging at the surface of the Quantum Dots. A large variety of poly-aza-macrocyclic ligands, have been studied in order to optimize the in vivo stability of the 64 Cu-radiolabeled complexes and their efficiency as radiopharmaceuticals

Co-registration of fluorescence diffuse optical tomography (fDOT) with positron emission tomography (PET) and development of multi-angle fDOT

International Nuclear Information System (INIS)

Tong, X.

2012-01-01

This thesis concerns the image processing of fluorescence diffuse optical tomography (fDOT), following two axes: fDOT image co-registration with PET (positron emission tomography) image and improvement of fDOT image reconstructions using mirrors to collect additional projections. It is presented in two parts:In the first part, an automatic method to co-register the fDOT images with PET images has been developed to correlate all the information from each modality. This co-registration method is based on automatic detection of fiducial markers (FM) present in both modalities. The particularity of this method is the use of optical surface image obtained in fDOT imaging system, which serves to identify the Z position of FM in optical images. We tested this method on a model of mice bearing tumor xenografts of MEN2A cancer cells that mimic a human medullary thyroid carcinoma, after a double injection of radiotracer [ 18 F] 2-fluoro-2-Deoxy-D-glucose (FDG) for PET imaging and optical fluorescent infrared tracer Sentidye. With the accuracy of our method, we can demonstrate that the signal of Sentidye is present both in the tumor and surrounding vessels.The fDOT reconstruction image quality is degraded along the Z axis due to a limited number of projections for reconstruction. In the second part, the work is oriented towards a new method of fDOT image reconstruction with a new multi-angle data acquisition system in placing two mirrors on each side of the animal. This work was conducted in collaboration with the CS Department of University College London (UCL), a partner of the European project FMT-XCT. TOAST software developed by this team was used as source code for the reconstruction algorithm, and was modified to adapt to the concerned problem. After several tests on the adjustment of program parameters, we applied this method on a phantom that simulating the biological tissue and on mice. The results showed an improvement in the reconstructed image of a semi

First steps towards ultrasound-based motion compensation for imaging and therapy: calibration with an optical system and 4D PET imaging

Directory of Open Access Journals (Sweden)

Julia eSchwaab

2015-11-01

Full Text Available Target motion, particularly in the abdomen, due to respiration or patient movement is still a challenge in many diagnostic and therapeutic processes. Hence, methods to detect and compensate this motion are required. Diagnostic ultrasound represents a non-invasive and dose-free alternative to fluoroscopy, providing more information about internal target motion than respiration belt or optical tracking.The goal of this project is to develop an ultrasound based motion tracking for real time motion correction in radiation therapy and diagnostic imaging, notably in 4D positron emission tomography (PET. In this work, a workflow is established to enable the transformation of ultrasound tracking data to the coordinates of the treatment delivery or imaging system – even if the ultrasound probe is moving due to respiration. It is shown that the ultrasound tracking signal is equally adequate for 4D PET image reconstruction as the clinically used respiration belt and provides additional opportunities in this concern. Furthermore, it is demonstrated that the ultrasound probe being within the PET field of view generally has no relevant influence on the image quality. The accuracy and precision of all the steps in the calibration workflow for ultrasound tracking based 4D PET imaging are found to be in an acceptable range for clinical implementation. Eventually, we show in vitro that an ultrasound based motion tracking in absolute room coordinates with a moving US-transducer is feasible.

Imaging and PET - PET/CT imaging

International Nuclear Information System (INIS)

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

2008-01-01

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

Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests.

Science.gov (United States)

Demir, Mustafa; Toklu, Türkay; Abuqbeitah, Mohammad; Çetin, Hüseyin; Sezgin, H Sezer; Yeyin, Nami; Sönmezoğlu, Kerim

2018-02-01

The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated aspects were spatial resolution, sensitivity, scatter fraction, count rate performance, image quality, count loss and random events correction accuracy. The findings of this study demonstrated superior sensitivity (~ 4 folds) of PET scanner in PET/MR compared to PET/CT system. Image quality test exhibited higher contrast in PET/MR (~ 9%) compared with PET/CT. The scatter fraction of PET/MR was 43.4% at noise equivalent count rate (NECR) peak of 218 kcps and the corresponding activity concentration was 17.7 kBq/cc. Whereas the scatter fraction of PET/CT was found as 39.2% at NECR peak of 72 kcps and activity concentration of 24.3 kBq/cc. The percentage error of the random event correction accuracy was 3.4% and 3.1% in PET/MR and PET/CT, respectively. It was concluded that PET/MR system is about 4 times more sensitive than PET/CT, and the contrast of hot lesions in PET/MR was ~ 9% higher than PET/CT. These outcomes also emphasize the possibility to achieve excellent clinical PET images with low administered dose and/or a short acquisition time in PET/MR.

Effects of attention on dichotic listening: an 15O-PET study

DEFF Research Database (Denmark)

Hugdahl, K; Law, I; Kyllingsbæk, Søren

2000-01-01

The present study investigated the effect of attention on brain activation in a dichotic listening situation. Dichotic listening is a technique to study laterality effects in the auditory sensory modality. Two different stimuli were presented simultaneously, one in each ear. Twelve subjects...... areas of Broca and Wernicke. The musical instrument stimuli mainly activated areas in visual association cortex, cerebellum, and the hippocampus. An interpretation of the findings is that attention has a facilitating effect for auditory processing, causing reduced activation in the primary auditory...... cortex when attention is explicitly recruited. The observed activations in the parietal lobe during the focused attention conditions could be part of a modality non-specific "attentional network"....

Development of a PET/Cerenkov-light hybrid imaging system

International Nuclear Information System (INIS)

Yamamoto, Seiichi; Hamamura, Fuka; Kato, Katsuhiko; Ogata, Yoshimune; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Hatazawa, Jun; Watabe, Hiroshi

2014-01-01

Purpose: Cerenkov-light imaging is a new molecular imaging technology that detects visible photons from high-speed electrons using a high sensitivity optical camera. However, the merit of Cerenkov-light imaging remains unclear. If a PET/Cerenkov-light hybrid imaging system were developed, the merit of Cerenkov-light imaging would be clarified by directly comparing these two imaging modalities. Methods: The authors developed and tested a PET/Cerenkov-light hybrid imaging system that consists of a dual-head PET system, a reflection mirror located above the subject, and a high sensitivity charge coupled device (CCD) camera. The authors installed these systems inside a black box for imaging the Cerenkov-light. The dual-head PET system employed a 1.2 × 1.2 × 10 mm 3 GSO arranged in a 33 × 33 matrix that was optically coupled to a position sensitive photomultiplier tube to form a GSO block detector. The authors arranged two GSO block detectors 10 cm apart and positioned the subject between them. The Cerenkov-light above the subject is reflected by the mirror and changes its direction to the side of the PET system and is imaged by the high sensitivity CCD camera. Results: The dual-head PET system had a spatial resolution of ∼1.2 mm FWHM and sensitivity of ∼0.31% at the center of the FOV. The Cerenkov-light imaging system's spatial resolution was ∼275μm for a 22 Na point source. Using the combined PET/Cerenkov-light hybrid imaging system, the authors successfully obtained fused images from simultaneously acquired images. The image distributions are sometimes different due to the light transmission and absorption in the body of the subject in the Cerenkov-light images. In simultaneous imaging of rat, the authors found that 18 F-FDG accumulation was observed mainly in the Harderian gland on the PET image, while the distribution of Cerenkov-light was observed in the eyes. Conclusions: The authors conclude that their developed PET/Cerenkov-light hybrid imaging

Initial tests of a prototype MRI-compatible PET imager

International Nuclear Information System (INIS)

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

2006-01-01

Multi-modality imaging 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 structure images created by MRI, will allow the correlation of form with function. Our group (a collaboration of West Virginia University and Jefferson Lab) is developing a system to acquire MRI and PET images contemporaneously. The prototype device consists of two opposed detector heads, operating in coincidence mode with an active FOV of 5x5x4 cm 3 . Each MRI-PET detector module consists of an array of LSO detector elements (2.5x2.5x15 mm 3 ) coupled through a long fiber optic light guide to a single Hamamatsu flat panel PSPMT. The fiber optic light guide is made of a glued assembly of 2 mm diameter acrylic fibers with a total length of 2.5 m. The use of a light guides allows the PSPMTs to be positioned outside the bore of the 3 T General Electric MRI scanner used in the tests. Photon attenuation in the light guides resulted in an energy resolution of ∼60% FWHM, interaction of the magnetic field with PSPMT further reduced energy resolution to ∼85% FWHM. Despite this effect, excellent multi-plane PET and MRI images of a simple disk phantom were acquired simultaneously. Future work includes improved light guides, optimized magnetic shielding for the PSPMTs, construction of specialized coils to permit high-resolution MRI imaging, and use of the system to perform simultaneous PET and MRI or MR-spectroscopy

Comparison of PET/CT with Sequential PET/MRI Using an MR-Compatible Mobile PET System.

Science.gov (United States)

Nakamoto, Ryusuke; Nakamoto, Yuji; Ishimori, Takayoshi; Fushimi, Yasutaka; Kido, Aki; Togashi, Kaori

2018-05-01

The current study tested a newly developed flexible PET (fxPET) scanner prototype. This fxPET system involves dual arc-shaped detectors based on silicon photomultipliers that are designed to fit existing MRI devices, allowing us to obtain fused PET and MR images by sequential PET and MR scanning. This prospective study sought to evaluate the image quality, lesion detection rate, and quantitative values of fxPET in comparison with conventional whole-body (WB) PET and to assess the accuracy of registration. Methods: Seventeen patients with suspected or known malignant tumors were analyzed. Approximately 1 h after intravenous injection of 18 F-FDG, WB PET/CT was performed, followed by fxPET and MRI. For reconstruction of fxPET images, MRI-based attenuation correction was applied. The quality of fxPET images was visually assessed, and the number of detected lesions was compared between the 2 imaging methods. SUV max and maximum average SUV within a 1 cm 3 spheric volume (SUV peak ) of lesions were also compared. In addition, the magnitude of misregistration between fxPET and MR images was evaluated. Results: The image quality of fxPET was acceptable for diagnosis of malignant tumors. There was no significant difference in detectability of malignant lesions between fxPET and WB PET ( P > 0.05). However, the fxPET system did not exhibit superior performance to the WB PET system. There were strong positive correlations between the 2 imaging modalities in SUV max (ρ = 0.88) and SUV peak (ρ = 0.81). SUV max and SUV peak measured with fxPET were approximately 1.1-fold greater than measured with WB PET. The average misregistration between fxPET and MR images was 5.5 ± 3.4 mm. Conclusion: Our preliminary data indicate that running an fxPET scanner near an existing MRI system provides visually and quantitatively acceptable fused PET/MR images for diagnosis of malignant lesions. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Comparison between PET/MR and PET/CT in evaluation of oncological patients%PET/MR与PET/CT的对比研究

Institute of Scientific and Technical Information of China (English)

徐白萱; 富丽萍; 关志伟; 尹大一; 刘家金; 杨晖; 张锦明; 陈英茂; 安宁豫

2014-01-01

Objective To verify the feasibility of the integrated PET/MR for oncological applications by comparing PET/MR with PET/CT in terms of lesion detection and quantitative measurement.Methods A total of 277 patients (165 males,112 females,average age (52.9± 12.6) years) voluntarily participated in this same-day PET/CT and PET/MR comparative study.The time interval between the two studies was 15-35 min.PET/CT images were acquired and reconstructed following standard protocols.PET/MR covered the body trunk with a sequence combination of transverse T1 weighted imaging (WI) 3D-volumetric interpolated breath-hold,T2WI turbo spin echo with fat saturation,diffusion-weighted imaging,and simultaneous PET acquisition.PET images were reconstructed by vender-provided attenuation correction methods.The results of PET/CT and PET/MR were regarded as positive if any modality (CT,PET or MRI) was positive.SUVmax was obtained by the manually drawn ROI.Detection rates were compared with x2 test and SUVmax from the two modalities was analyzed with Spearman correlation analysis.Results A total of 353 lesions were detected in 220 patients.Compared to PET/CT,PET/MR revealed 30 additional true-positive lesions,while missed 6.The detection rates between PET/CT and PET/MR were significantly different (P＜0.05).The lesion-based and patient-based consistency was 89.8％ (317/353) and 85.9％ (189/220),respectively.There were significant correlations of SUVmax between PET/MR and PET/CT for lesions(rs =0.91,P＜0.01) and for normal tissues(rs =0.62-0.76,all P＜0.01).Conclusions With reference to PET/CT,integrated PET/MR may provide comparable semi-quantitative measurements of pathological lesions as well as normal tissues.Integrated PET/MR may be more effective to detect lesions in abdomen and pelvis.%目的 通过与PET/CT在病灶检测及定量分析方面的比较,论证PET/MR一体机应用于临床的可行性.方法 2012年5月至2013年2月共300例患者同天间隔15 ～ 35 min行PET/CT和PET

Initial tests of a prototype MRI-compatible PET imager

Energy Technology Data Exchange (ETDEWEB)

Raylman, Raymond R. [Center for Advanced Imaging, Department of Radiology, West Virginia University, HSB Box 9236, Morgantown, WV (United States)]. E-mail: rraylman@wvu.edu; Majewski, Stan [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Lemieux, Susan [Center for Advanced Imaging, Department of Radiology, West Virginia University, HSB Box 9236, Morgantown, WV (United States); Velan, S. Sendhil [Center for Advanced Imaging, Department of Radiology, West Virginia University, HSB Box 9236, Morgantown, WV (United States); Kross, Brain [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Popov, Vladimir [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Smith, Mark F. [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Weisenberger, Andrew G. [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Wojcik, Randy [Detector Group, Physics Division, Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2006-12-20

Multi-modality imaging 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 structure images created by MRI, will allow the correlation of form with function. Our group (a collaboration of West Virginia University and Jefferson Lab) is developing a system to acquire MRI and PET images contemporaneously. The prototype device consists of two opposed detector heads, operating in coincidence mode with an active FOV of 5x5x4 cm{sup 3}. Each MRI-PET detector module consists of an array of LSO detector elements (2.5x2.5x15 mm{sup 3}) coupled through a long fiber optic light guide to a single Hamamatsu flat panel PSPMT. The fiber optic light guide is made of a glued assembly of 2 mm diameter acrylic fibers with a total length of 2.5 m. The use of a light guides allows the PSPMTs to be positioned outside the bore of the 3 T General Electric MRI scanner used in the tests. Photon attenuation in the light guides resulted in an energy resolution of {approx}60% FWHM, interaction of the magnetic field with PSPMT further reduced energy resolution to {approx}85% FWHM. Despite this effect, excellent multi-plane PET and MRI images of a simple disk phantom were acquired simultaneously. Future work includes improved light guides, optimized magnetic shielding for the PSPMTs, construction of specialized coils to permit high-resolution MRI imaging, and use of the system to perform simultaneous PET and MRI or MR-spectroscopy.

Pet Problems at Home: Pet Problems in the Community.

Science.gov (United States)

Soltow, Willow

1984-01-01

Discusses problems of pets in the community, examining the community's role related to disruptive pets and pet overpopulation. Also discusses pet problems at home, offering advice on selecting a pet, meeting a pet's needs, and disciplining pets. Includes a list of books, films/filmstrips, teaching materials, and various instructional strategies.…

Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests

OpenAIRE

Mustafa Demir; Türkay Toklu; Mohammad Abuqbeitah; Hüseyin Çetin; H. Sezer Sezgin; Nami Yeyin; Kerim Sönmezoğlu

2018-01-01

Objective: The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. Methods: According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated...

Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests

OpenAIRE

Demir, Mustafa; Toklu, Türkay; Abuqbeitah, Mohammad; Çetin, Hüseyin; Sezgin, H. Sezer; Yeyin, Nami; Sönmezoğlu, Kerim

2018-01-01

Objective: The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. Methods: According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated asp...

Simultaneous MRI and PET imaging of a rat brain

Energy Technology Data Exchange (ETDEWEB)

Raylman, Raymond R [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Majewski, Stan [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Lemieux, Susan K [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Velan, S Sendhil [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States); Kross, Brian [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Popov, Vladimir [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Smith, Mark F [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Weisenberger, Andrew G [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Zorn, Carl [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Ave., Newport News, VA (United States); Marano, Gary D [Center for Advanced Imaging, Department of Radiology, Box 9236, West Virginia University, Morgantown, WV (United States)

2006-12-21

Multi-modality imaging 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 structure images created by MRI will allow the correlation of form with function. Our group is developing a system to acquire MRI and PET images contemporaneously. The prototype device consists of two opposed detector heads, operating in coincidence mode. Each MRI-PET detector module consists of an array of LSO detector elements coupled through a long fibre optic light guide to a single Hamamatsu flat panel position-sensitive photomultiplier tube (PSPMT). The use of light guides allows the PSPMTs to be positioned outside the bore of a 3T MRI scanner where the magnetic field is relatively small. To test the device, simultaneous MRI and PET images of the brain of a male Sprague Dawley rat injected with FDG were successfully obtained. The images revealed no noticeable artefacts in either image set. Future work includes the construction of a full ring PET scanner, improved light guides and construction of a specialized MRI coil to permit higher quality MRI imaging.

Simultaneous MRI and PET imaging of a rat brain

International Nuclear Information System (INIS)

Raylman, Raymond R; Majewski, Stan; Lemieux, Susan K; Velan, S Sendhil; Kross, Brian; Popov, Vladimir; Smith, Mark F; Weisenberger, Andrew G; Zorn, Carl; Marano, Gary D

2006-01-01

Multi-modality imaging 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 structure images created by MRI will allow the correlation of form with function. Our group is developing a system to acquire MRI and PET images contemporaneously. The prototype device consists of two opposed detector heads, operating in coincidence mode. Each MRI-PET detector module consists of an array of LSO detector elements coupled through a long fibre optic light guide to a single Hamamatsu flat panel position-sensitive photomultiplier tube (PSPMT). The use of light guides allows the PSPMTs to be positioned outside the bore of a 3T MRI scanner where the magnetic field is relatively small. To test the device, simultaneous MRI and PET images of the brain of a male Sprague Dawley rat injected with FDG were successfully obtained. The images revealed no noticeable artefacts in either image set. Future work includes the construction of a full ring PET scanner, improved light guides and construction of a specialized MRI coil to permit higher quality MRI imaging

Indium zinc oxide films deposited on PET by LF magnetron sputtering

International Nuclear Information System (INIS)

Kim, Eun Lyoung; Jung, Sang Kooun; Sohn, Sang Ho; Park, Duck Kyu

2007-01-01

Indium zinc oxide (IZO) has attracted much attention recently for use in transparent oxide films compared with the ITO film. We carried out the deposition of IZO on a polyethylene terapthalate (PET) substrate at room temperature by a low-frequency (LF) magnetron sputtering system. These films have amorphous structures with excellent electrical stability, surface uniformity and high optical transmittance. The effects of LF applied voltage and O 2 flow rate were investigated. The electrical and optical properties were studied. At optimal deposition conditions, thin films of IZO with a sheet resistance of 32 Ω/sq and an optical transmittance of over 80% in the visible spectrum range were achieved. The IZO thin films fabricated by this method do not require substrate heating during the film preparation of any additional post-deposition annealing treatment. The experimental results show that films with good qualities of surface morphology, transmittance and electrical conduction can be grown by the LF magnetron sputtering method on PET which is recommendable

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Immuno PET/MR imaging allows specific detection of Aspergillus fumigatus lung infection in vivo

DEFF Research Database (Denmark)

Rolle, Anna-Maria; Hasenberg, Mike; Thornton, Christopher R.

2016-01-01

-infected mice allowed specific localization of lung infection when combined with PET. Optical imaging with a fluorochrome-labeled version of the mAb showed colocalization with invasive hyphae. The mAb-based newly developed PET tracer [64Cu]DOTA-JF5 distinguishedIPA from bacterial lung infections and...

Growth and characterization of indium tin oxide thin films deposited on PET substrates

International Nuclear Information System (INIS)

Lee, Jaehyeong; Jung, Hakkee; Lee, Jongin; Lim, Donggun; Yang, Keajoon; Yi, Junsin; Song, Woo-Chang

2008-01-01

Transparent and conductive indium tin oxide (ITO) thin films were deposited onto polyethylene terephthalate (PET) by d.c. magnetron sputtering as the front and back electrical contact for applications in flexible displays and optoelectronic devices. In addition, ITO powder was used for sputter target in order to reduce the cost and time of the film formation processes. As the sputtering power and pressure increased, the electrical conductivity of ITO films decreased. The films were increasingly dark gray colored as the sputtering power increased, resulting in the loss of transmittance of the films. When the pressure during deposition was higher, however, the optical transmittance improved at visible region of light. ITO films deposited onto PET have shown similar optical transmittance and electrical resistivity, in comparison with films onto glass substrate. High quality films with resistivity as low as 2.5 x 10 -3 Ω cm and transmittance over 80% have been obtained on to PET substrate by suitably controlling the deposition parameters

Comparison of lesion detection and quantitation of tracer uptake between PET from a simultaneously acquiring whole-body PET/MR hybrid scanner and PET from PET/CT

International Nuclear Information System (INIS)

Wiesmueller, Marco; Schmidt, Daniela; Beck, Michael; Kuwert, Torsten; Gall, Carl C. von; Quick, Harald H.; Navalpakkam, Bharath; Lell, Michael M.; Uder, Michael; Ritt, Philipp

2013-01-01

PET/MR hybrid scanners have recently been introduced, but not yet validated. The aim of this study was to compare the PET components of a PET/CT hybrid system and of a simultaneous whole-body PET/MR hybrid system with regard to reproducibility of lesion detection and quantitation of tracer uptake. A total of 46 patients underwent a whole-body PET/CT scan 1 h after injection and an average of 88 min later a second scan using a hybrid PET/MR system. The radioactive tracers used were 18 F-deoxyglucose (FDG), 18 F-ethylcholine (FEC) and 68 Ga-DOTATATE (Ga-DOTATATE). The PET images from PET/CT (PET CT ) and from PET/MR (PET MR ) were analysed for tracer-positive lesions. Regional tracer uptake in these foci was quantified using volumes of interest, and maximal and average standardized uptake values (SUV max and SUV avg , respectively) were calculated. Of the 46 patients, 43 were eligible for comparison and statistical analysis. All lesions except one identified by PET CT were identified by PET MR (99.2 %). In 38 patients (88.4 %), the same number of foci were identified by PET CT and by PET MR . In four patients, more lesions were identified by PET MR than by PET CT , in one patient PET CT revealed an additional focus compared to PET MR . The mean SUV max and SUV avg of all lesions determined by PET MR were by 21 % and 11 % lower, respectively, than the values determined by PET CT (p CT and PET MR were minor, but statistically significant. Nevertheless, a more detailed study of the quantitative accuracy of PET MR and the factors governing it is needed to ultimately assess its accuracy in measuring tissue tracer concentrations. (orig.)

Tracking accuracy evaluation of a PET-enabled glove for molecular image-guided surgery

International Nuclear Information System (INIS)

Gruionu, L.G.; Wilson, E.; Cleary, K.; Wong, K.H.; Weinberg, I.N.

2007-01-01

We are developing a new type of PET scanner with a flexible geometry that can provide in situ functional imaging in environments where conventional full-body PET scanning would be difficult or impossible. Because PET reconstruction depends on localizing emissions from the radiotracer inside the patient, our system must have a means of continuously monitoring the detectors' position and orientation. We therefore evaluated the accuracy of using electromagnetic tracking for this task by comparing position measurements from the electromagnetic tracking system to a reference optical tracking system. The mean error in localization was 2.1 mm. (orig.)

Tracking accuracy evaluation of a PET-enabled glove for molecular image-guided surgery

Energy Technology Data Exchange (ETDEWEB)

Gruionu, L.G. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Faculty of Engineering and Management of Technological Systems, Univ. of Craiova, Craiova (Romania); Wilson, E.; Cleary, K.; Wong, K.H. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Weinberg, I.N. [Fast Imaging Co., Bethesda, MD (United States)

2007-06-15

We are developing a new type of PET scanner with a flexible geometry that can provide in situ functional imaging in environments where conventional full-body PET scanning would be difficult or impossible. Because PET reconstruction depends on localizing emissions from the radiotracer inside the patient, our system must have a means of continuously monitoring the detectors' position and orientation. We therefore evaluated the accuracy of using electromagnetic tracking for this task by comparing position measurements from the electromagnetic tracking system to a reference optical tracking system. The mean error in localization was 2.1 mm. (orig.)

Novel Electro-Optical Coupling Technique for Magnetic Resonance-Compatible Positron Emission Tomography Detectors

Directory of Open Access Journals (Sweden)

Peter D. Olcott

2009-03-01

Full Text Available A new magnetic resonance imaging (MRI-compatible positron emission tomography (PET detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

Novel electro-optical coupling technique for magnetic resonance-compatible positron emission tomography detectors.

Science.gov (United States)

Olcott, Peter D; Peng, Hao; Levin, Craig S

2009-01-01

A new magnetic resonance imaging (MRI)-compatible positron emission tomography (PET) detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL) diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

Detection of Cancer with PET and PET/CT in Asymptomatic Volunteers

International Nuclear Information System (INIS)

Chung, Ji In; Choi, Joon Young; Lee, Kyung Han; Kim, Byung Tae; Choi, Yoon Ho; Cho, Han Byoul; Shim, Jae Yong

2009-01-01

We retrospectively investigated the diagnostic performance of 18 F-fluorodeoxyglucose positron emission tomography (PET) and PET/CT for cancer detection in asymptomatic health-check examinees. This study consisted of 5091 PET or PET/CT conducted as part of annual health examination at one hospital from March 1998 to February 2008. To find the incidence of cancers, medical records of the subjects were thoroughly reviewed for a follow-up period of one year. The patterns of formal readings of PET and PET/CT were analyzed to assess the sensitivity and specificity for cancer detection. The histopathology and stage of the cancers were evaluated in relation to the results of PET. Eighty-six cancers (1.7%) were diagnosed within one year after PET or PET/CT. When PET and PET/CT results were combined, the sensitivity was 48.8% and specificity was 81.1% for cancer detection. PET only had a sensitivity of 46.2% and a specificity of 81.4%, and PET/CT only had a sensitivity of 75.0% and a specificity of 78.5% respectively. There were no significant differences in cancer site, stage and histopathology between PET positive and PET negative cancers. In 19.3% of formal readings of PET and PET/CT, further evaluation to exclude malignancy or significant disease was recommended. Head and neck area and upper gastrointestinal tract were commonly recommended sites for further evaluation. PET and PET/CT showed moderate performance for detecting cancers in asymptomatic adults in this study. More experience and further investigation are needed to overcome limitations of PET and PET/CT for cancer screening

PET

DEFF Research Database (Denmark)

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

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

Clinical usefulness of PET in the management of oral cancer. Comparison between FDG-PET and MET-PET

International Nuclear Information System (INIS)

Kitagawa, Yoshimasa; Saitoh, Masaaki; Nakamura, Mikiko

2007-01-01

Inductive chemoradiotherapy has played an important role in preserving organs and functions in patients with oral squamous cell carcinoma (SCC). To determine whether a reduced form of surgery should be performed after chemoradiotherapy, accurate evaluation of residual tumor cells is essential. We investigated the clinical value of positron emission tomography with 18 F labeled fluorodeoxyglucose (FDG-PET) in the management of oral SCCs. Forty-five patients underwent two FDG-PET studies, one prior to and one at 6 weeks after the chemoradiotherapy. Pretreatment FDG-PET was useful in predicting the response to treatment. Posttreatment FDG-PET could evaluate residual viable cells and prognosis. Organ preservation may be feasible based on PET evaluation. Hence FDG-PET is a valuable tool in the treatment of oral cancer. 11 C-Methionine (MET) is another promising tracer for PET that can be used to assess metabolic demand for amino acids in cancer cells. A MET-PET and FDG-PET study was performed during the same period to investigate diagnostic accuracy in 40 oral malignancies. Sensitivity and positive predictive value of MET-PET were 95% and 100%, respectively, and were comparable with those of FDG-PET. Further study is required to determine the diagnostic significance of MET-PET in evaluating response to chemoradiotherapy. (author)

Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

International Nuclear Information System (INIS)

Jung, Jin Ho; Choi, Yong; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun; Oh, Chang Hyun; Park, Hyun-wook; Kim, Kyung Min; Kim, Jong Guk

2015-01-01

Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

Energy Technology Data Exchange (ETDEWEB)

Jung, Jin Ho; Choi, Yong, E-mail: ychoi.image@gmail.com; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun [Department of Electronic Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 121-742 (Korea, Republic of); Oh, Chang Hyun; Park, Hyun-wook [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Kyung Min; Kim, Jong Guk [Korea Institute of Radiological and Medical Science, 75 Nowon-ro, Nowon-gu, Seoul 139-709 (Korea, Republic of)

2015-05-15

Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

Evaluation of attenuation correction in cardiac PET using PET/MR.

Science.gov (United States)

Lau, Jeffrey M C; Laforest, R; Sotoudeh, H; Nie, X; Sharma, S; McConathy, J; Novak, E; Priatna, A; Gropler, R J; Woodard, P K

2017-06-01

Simultaneous acquisition Positron emission tomography/magnetic resonance (PET/MR) is a new technology that has potential as a tool both in research and clinical diagnosis. However, cardiac PET acquisition has not yet been validated using MR imaging for attenuation correction (AC). The goal of this study is to evaluate the feasibility of PET imaging using a standard 2-point Dixon volume interpolated breathhold examination (VIBE) MR sequence for AC. Evaluation was performed in both phantom and patient data. A chest phantom containing heart, lungs, and a lesion insert was scanned by both PET/MR and PET/CT. In addition, 30 patients underwent whole-body 18 F-fluorodeoxyglucose PET/CT followed by simultaneous cardiac PET/MR. Phantom study showed 3% reduction of activity values in the myocardium due to the non-inclusion of the phased array coil in the AC. In patient scans, average standardized uptake values (SUVs) obtained by PET/CT and PET/MR showed no significant difference (n = 30, 4.6 ± 3.5 vs 4.7 ± 2.8, P = 0.47). There was excellent per patient correlation between the values acquired by PET/CT and PET/MR (R 2  = 0.97). Myocardial SUVs PET imaging using MR for AC shows excellent correlation with myocardial SUVs obtained by standard PET/CT imaging. The 2-point Dixon VIBE MR technique can be used for AC in simultaneous PET/MR data acquisition.

Role of PET in gene therapy

International Nuclear Information System (INIS)

Lee, Kyung Han

2002-01-01

In addition to the well-established use of positron emission tomography (PET) in clinical oncology, novel roles for PET are rapidly emerging in the field of gene therapy. Methods for controlled gene delivery to living bodies, made available through advances in molecular biology, are currently being employed in animals for reasearch purposes and in humans to treat diseases such as cancer. Although gene therapy is still in its early developmental stage, it is perceived that many serious illnesses could be treated successfully by the use of therapeutic gene delivery. A major challenge for the widespread use of human gene therapy is to achieve a controlled and effective delivery of foreign genes to target cells and subsequently, adequate levels of expression. As such, the availability of noninvasive imaging methods to accurately assess the location, duration, and level of transgene expression is critical for optimizing gene therapy strategies. Current endeavors to achieve this goal include methods that utilize magnetic resonance imaging, optical imaging, and nuclear imaging techniques. As for PET, reporter systems that utilize gene encoding enzymes that accumulate postion labeled substrates and those transcribing surface receptors that bind specific positron labeled ligands have been successfully developed. More recent advances in this area include improved reporter gene constructs and radiotracers, introduction of potential strategies to monitor endogenous gene expression, and human pilot studies evaluating the distribution and safety of reporter PET tracers. The remarkably rapid progress occuring in gene imaging technology indicates its importance and wide range of application. As such, gene imaging is likely to become a major and exciting new area for future application of PET technology

Role of PET in gene therapy

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyung Han [School of Medicine, Sungkyunkwan Univ., Seoul (Korea, Republic of)

2002-02-01

In addition to the well-established use of positron emission tomography (PET) in clinical oncology, novel roles for PET are rapidly emerging in the field of gene therapy. Methods for controlled gene delivery to living bodies, made available through advances in molecular biology, are currently being employed in animals for reasearch purposes and in humans to treat diseases such as cancer. Although gene therapy is still in its early developmental stage, it is perceived that many serious illnesses could be treated successfully by the use of therapeutic gene delivery. A major challenge for the widespread use of human gene therapy is to achieve a controlled and effective delivery of foreign genes to target cells and subsequently, adequate levels of expression. As such, the availability of noninvasive imaging methods to accurately assess the location, duration, and level of transgene expression is critical for optimizing gene therapy strategies. Current endeavors to achieve this goal include methods that utilize magnetic resonance imaging, optical imaging, and nuclear imaging techniques. As for PET, reporter systems that utilize gene encoding enzymes that accumulate postion labeled substrates and those transcribing surface receptors that bind specific positron labeled ligands have been successfully developed. More recent advances in this area include improved reporter gene constructs and radiotracers, introduction of potential strategies to monitor endogenous gene expression, and human pilot studies evaluating the distribution and safety of reporter PET tracers. The remarkably rapid progress occuring in gene imaging technology indicates its importance and wide range of application. As such, gene imaging is likely to become a major and exciting new area for future application of PET technology.

18F-FDG PET and PET/CT in Burkitt's lymphoma

International Nuclear Information System (INIS)

Karantanis, Dimitrios; Durski, Jolanta M.; Lowe, Val J.; Nathan, Mark A.; Mullan, Brian P.; Georgiou, Evangelos; Johnston, Patrick B.; Wiseman, Gregory A.

2010-01-01

Objective: To explore the value of 18 F fluorodeoxy-glucose (FDG) positron emission tomography (PET) in Burkitt's lymphoma. Methods: All Burkitt's lymphoma patients referred for FDG PET or FDG PET/computed tomography (CT) exams at our institution from June 2003 to June 2006 were included. Selected patients were followed and clinical information was reviewed retrospectively. Results from FDG PET-PET/CT, as blindly reviewed by a consensus of two experienced readers, were compared with the status of the disease as determined by other laboratory, clinical and imaging exams and clinical follow-up. FDG PET-PET/CT results were classified as true positive or negative and false positive or negative. The degree of FDG uptake in the positive lesions was semiquantified as maximum standard uptake value (SUVmax). Results: Fifty-seven FDG PET-PET/CT exams were done in 15 patients. Seven exams were done for initial staging, 8 during and 14 after the completion of therapy, and 28 for disease surveillance. For nodal disease FDG PET-PET/CT was true positive in 8, true negative in 47 and false positive in 2 exams (sensitivity 100%, specificity 96%). For extranodal disease FDG PET-PET/CT was true positive in 6, true negative in 48 and false positive in 3 exams (sensitivity 100%, specificity 94%). The mean SUVmax for the positive nodal lesions was 15.7 (range 6.9-21.7, median 18.5) and for extranodal lesions was 14.2 (range 6.2-24.3, median 12.4). Conclusions: FDG PET-PET/CT is sensitive for the detection of viable disease in Burkitt's lymphoma. Affected areas demonstrated high degree of uptake that was reversible upon successful implementation of treatment.

Optical and electrical properties of some electron and proton irradiated polymers

International Nuclear Information System (INIS)

Mishra, R.; Tripathy, S.P.; Sinha, D.; Dwivedi, K.K.; Ghosh, S.; Khathing, D.T.; Mueller, M.; Fink, D.; Chung, W.H.

2000-01-01

Ion beam treatment studies have been carried out to investigate the potential for improvements in conductivity properties of the polymers Polytetrafluroethylene (PTFE), Polyimide (PI), Polyethyleneterepthalate (PET) and Polypropylene (PP), after 2 MeV electron and 62 MeV proton irradiation. The shift in optical absorption edges as observed by UV-VIS spectra of the irradiated polymers has been correlated to the optical band-gap using Tauc's expression. A decrease in the optical band-gap has been observed in irradiated PP and PTFE, but no considerable change was found for the optical band-gaps of PET and PI. Further AC conductivity measurements confirmed an increase in conductivity in electron irradiated PP

PET or PET-CT with cancer screening

International Nuclear Information System (INIS)

Wang Taisong; Zhao Jinhua; Song Jianhua

2007-01-01

At present, cancer screening remains a lot of debate in contemporary medical practice. Many constitutes have done a lot of experiments in cancer screening. The same version is that recommendations and decisions regarding cancer screening should be based on reliable data, not self- approbation. Now, some institutes advocate 18 F-FDG PET or 18 F-FDG PET-CT for cancer screening, here, discussed status quo, potential financial, radiation safety and statistical data in 18 F-FDG PET or 18 F-FDG PET- CT cancer screening. (authors)

PET / MRI vs. PET / CT. Indications Oncology

International Nuclear Information System (INIS)

Oliva González, Juan P.

2016-01-01

Hybrid techniques in Nuclear Medicine is currently a field in full development for diagnosis and treatment of various medical conditions. With the recent advent of PET / MRI much it speculated about whether or not it is superior to PET / CT especially in oncology. The Conference seeks to clarify this situation by dealing issues such as: State of the art technology PET / MRI; Indications Oncology; Some clinical cases. It concludes by explaining the oncological indications of both the real and current situation of the PET / MRI. (author)

Application of PET and PET/CT imaging for cancer screening

International Nuclear Information System (INIS)

Chen Yenkung; Hu Fenglan; Shen Yehyou; Liao, A.C.; Hung, T.Z.; Su, Chentau; Chen Liangkuang

2004-01-01

The aim of this study was to evaluate the potential application of 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) and PET/CT for cancer screening in asymptomatic individuals. Methods: The subjects consisted of 3631 physical check up examinees (1947 men, 1684 women; mean age ±SD, 52.1±8.2 y) with non-specific medical histories. Whole-body FDG PET (or PET/CT), ultrasound and tumor markers were performed on all patients. Focal hypermetabolic areas with intensities equal to or exceeding the level of FDG uptake in the brain and bladder were considered abnormal and interpreted as neoplasia. Follow-up periods were longer than one year. Results: Among the 3631 FDG PET (including 1687 PET/CT), ultrasound and tumor markers examinations, malignant tumors were discovered in 47 examinees (1.29%). PET findings were true-positive in 38 of the 47 cancers (80.9%). In addition, 32 of the 47 cancers were performed with the PET-CT scan. PET detected cancer lesions in 28 of the 32 examinees. However, the CT detected cancer lesions in only 15 of 32 examinees. Conclusion: The sensitivity of FDG PET in the detection of a wide variety of cancers is high. Most cancer can be detected with FDG PET in a resectable stage. CT of the PET/CT for localization and characteristics of the lesion shows an increased specificity of the PET scan. Using ultrasound and tumor markers may complement the PET scan in cancer screening for hepatic and urologic neoplasms. (authors)

PET/CT in lymphoma patients; PET-CT bei Lymphompatienten

Energy Technology Data Exchange (ETDEWEB)

Steinert, H.C. [Universitaetsspital Zuerich, Klinik und Poliklinik fuer Nuklearmedizin (Switzerland)

2004-11-01

First results of PET/CT in Hodgkin's disease (HD) and aggressive non-Hodgkin's lymphoma (NHL) are reported. From March 2001 to August 2004 822 PET/CT were performed at our clinic in lymphoma patients for primary staging, restaging after therapy, and diagnosis of recurrence. For coregistration non contrast-enhanced low-dose CT were used. Due to the exact anatomic localization of {sup 18}F-FDG accumulating lesions equivocal or false positive PET findings are avoided. In comparison to contrast enhanced CT, PET/CT has a higher sensitivity and specificity in patients with HD and aggressive NHL. Integration of PET/CT in treatment planning of radiation therapy optimizes the field volume. Even in the initial phase of clinical evaluation, PET/CT has proven useful in staging and restaging of lymphoma. The exact anatomic localization of the PET findings is essential for a precise report, for treatment planning of radiation therapy, and for planning surgical biopsy. (orig.) [German] Erste Ergebnisse der PET-CT bei Morbus Hodgkin (HD) und den aggressiven Non-Hodgkin-Lymphomen (NHL) werden beschrieben. Von Maerz 2001 bis August 2004 wurden 822 PET-CT bei Lymphompatienten zum primaeren Staging, zum Restaging nach Therapie und zur Rezidivdiagnostik an unserer Klinik durchgefuehrt. Fuer die Koregistration wurde ein Low-dose-CT ohne i.v.-Kontrastmittel verwendet. Durch die exakte anatomische Zuordnung der {sup 18}F-FDG aufnehmenden Laesionen wurden unklare oder falsch-positive PET-Befunde vermieden. Die PET-CT erzielte im Vergleich zur KM-verstaerkten CT eine hoehere Sensitivitaet und Spezifitaet bei Patienten mit HD und aggressiven NHL. Die Integration der PET-CT in die Planung der Strahlentherapie fuehrte zu einer Optimierung der Feldgrenzen. Die PET-CT hat sich bereits in der Phase der initialen klinischen Evaluation als wertvoll beim Staging und Restaging von Lymphomen erwiesen. Die exakte anatomische Zuordnung der PET-Informationen ist fuer eine sichere Befundung

Do carotid MR surface coils affect PET quantification in PET/MR imaging?

International Nuclear Information System (INIS)

Willemink, Martin J; Eldib, Mootaz; Leiner, Tim; Fayad, Zahi A; Mani, Venkatesh

2015-01-01

To evaluate the effect of surface coils for carotid MR imaging on PET quantification in a clinical simultaneous whole-body PET/MR scanner. A cylindrical phantom was filled with a homogeneous 2L water-FDG mixture at a starting dose of 301.2MBq. Clinical PET/MR and PET/CT systems were used to acquire PET-data without a coil (reference standard) and with two carotid MRI coils (Siemens Special Purpose 8-Channel and Machnet 4-Channel Phased Array). PET-signal attenuation was evaluated with Osirix using 51 (PET/MR) and 37 (PET/CT) circular ROIs. Mean and maximum standardized uptake values (SUVs) were quantified for each ROI. Furthermore, SUVs of PET/MR and PET/CT were compared. For validation, a patient was scanned with an injected dose of 407.7MBq on both a PET/CT and a PET/MR system without a coil and with both coils. PET/MR underestimations were -2.2% (Siemens) and -7.8% (Machnet) for SUVmean, and -1.2% (Siemens) and -3.3% (Machnet) for SUVmax, respectively. For PET/CT, underestimations were -1.3% (Siemens) and -1.4% (Machnet) for SUVmean and -0.5% (both Siemens and Machnet) for SUVmax, respectively using no coil data as reference. Except for PET/CT SUVmax values all differences were significant. SUVs differed significantly between PET/MR and PET/CT with SUVmean values of 0.51-0.55 for PET/MR and 0.68-0.69 for PET/CT, respectively. The patient examination showed that median SUVmean values measured in the carotid arteries decreased from 0.97 without a coil to 0.96 (Siemens) and 0.88 (Machnet). Carotid surface coils do affect attenuation correction in both PET/MR and PET/CT imaging. Furthermore, SUVs differed significantly between PET/MR and PET/CT.

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Design and development of 1 mm resolution PET detectors with position-sensitive PMTs

CERN Document Server

Shao, Y; Chatziioannou, A F

2002-01-01

We report our investigation of a positron emission tomography (PET) detector with 1 m spatial resolution. The prototype detector consists of a 9x9 array of 1x1x10 mm sup 3 lutetium oxyorthosilicate (LSO) scintillator crystals coupled to Hamamatsu R5900-M64 or R5900-C12 position sensitive PMT by either optical fibers or an optical fiber bundle. With a 511 eV gamma source, the intrinsic spatial resolution of this detector was measured to be 0.92 mm. All crystals were well resolved in the flood source histogram. The measured energy and coincidence timing resolutions were around 26% and 4 ns, respectively, demonstrating that sufficient light can be extracted from these small crystals for PET applications.

Effect of sputtering parameters on optical and electrical properties of ITO films on PET substrates

International Nuclear Information System (INIS)

Tseng, Kun-San; Lo, Yu-Lung

2013-01-01

The optical and electrical properties of indium tin oxide (ITO) thin films deposited on flexible polyethylene terephthalate (PET) substrates using a DC magnetron sputtering technique are investigated as a function of the deposition time, the argon flow rate and the target–substrate distance. It is found that all of the ITO films contain a high fraction of amorphous phase. The volume fraction of crystallite precipitates in the amorphous host increases with an increasing deposition time or a reducing argon flow rate. The deposition time and argon flow rate have higher effects on the optical transparency of the ITO films than the target–substrate distance has. Increasing film thickness is not the only reason for the transmittance reduced. It is found that an increase of the extinction coefficient by increasing deposition time or an increase of the refractive index by decreasing argon flow rate also reduces the transmittance of thin film. For a constant deposition time, the resistivity of the ITO films reduces with a reducing argon flow rate or a reducing target–substrate distance. For a constant argon flow rate, a critical value of the deposition time exists at which both the resistivity and the effect of the target–substrate distance are minimized. Finally, it is concluded that the film resistivity has low sensitivity to the target–substrate distance if the best deposition conditions which mostly attain the lowest resistivity are matched.

Effect of sputtering parameters on optical and electrical properties of ITO films on PET substrates

Science.gov (United States)

Tseng, Kun-San; Lo, Yu-Lung

2013-11-01

The optical and electrical properties of indium tin oxide (ITO) thin films deposited on flexible polyethylene terephthalate (PET) substrates using a DC magnetron sputtering technique are investigated as a function of the deposition time, the argon flow rate and the target-substrate distance. It is found that all of the ITO films contain a high fraction of amorphous phase. The volume fraction of crystallite precipitates in the amorphous host increases with an increasing deposition time or a reducing argon flow rate. The deposition time and argon flow rate have higher effects on the optical transparency of the ITO films than the target-substrate distance has. Increasing film thickness is not the only reason for the transmittance reduced. It is found that an increase of the extinction coefficient by increasing deposition time or an increase of the refractive index by decreasing argon flow rate also reduces the transmittance of thin film. For a constant deposition time, the resistivity of the ITO films reduces with a reducing argon flow rate or a reducing target-substrate distance. For a constant argon flow rate, a critical value of the deposition time exists at which both the resistivity and the effect of the target-substrate distance are minimized. Finally, it is concluded that the film resistivity has low sensitivity to the target-substrate distance if the best deposition conditions which mostly attain the lowest resistivity are matched.

Effect of sputtering parameters on optical and electrical properties of ITO films on PET substrates

Energy Technology Data Exchange (ETDEWEB)

Tseng, Kun-San [Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Lo, Yu-Lung, E-mail: loyl@mail.ncku.edu.tw [Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan (China)

2013-11-15

The optical and electrical properties of indium tin oxide (ITO) thin films deposited on flexible polyethylene terephthalate (PET) substrates using a DC magnetron sputtering technique are investigated as a function of the deposition time, the argon flow rate and the target–substrate distance. It is found that all of the ITO films contain a high fraction of amorphous phase. The volume fraction of crystallite precipitates in the amorphous host increases with an increasing deposition time or a reducing argon flow rate. The deposition time and argon flow rate have higher effects on the optical transparency of the ITO films than the target–substrate distance has. Increasing film thickness is not the only reason for the transmittance reduced. It is found that an increase of the extinction coefficient by increasing deposition time or an increase of the refractive index by decreasing argon flow rate also reduces the transmittance of thin film. For a constant deposition time, the resistivity of the ITO films reduces with a reducing argon flow rate or a reducing target–substrate distance. For a constant argon flow rate, a critical value of the deposition time exists at which both the resistivity and the effect of the target–substrate distance are minimized. Finally, it is concluded that the film resistivity has low sensitivity to the target–substrate distance if the best deposition conditions which mostly attain the lowest resistivity are matched.

[Principles of PET].

Science.gov (United States)

Beuthien-Baumann, B

2018-05-01

Positron emission tomography (PET) is a procedure in nuclear medicine, which is applied predominantly in oncological diagnostics. In the form of modern hybrid machines, such as PET computed tomography (PET/CT) and PET magnetic resonance imaging (PET/MRI) it has found wide acceptance and availability. The PET procedure is more than just another imaging technique, but a functional method with the capability for quantification in addition to the distribution pattern of the radiopharmaceutical, the results of which are used for therapeutic decisions. A profound knowledge of the principles of PET including the correct indications, patient preparation, and possible artifacts is mandatory for the correct interpretation of PET results.

Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

International Nuclear Information System (INIS)

Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah

2014-01-01

Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after 18 F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast-enhanced PET

Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

Energy Technology Data Exchange (ETDEWEB)

Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah [Yeungnam Univ. Hospital, Daegu (Korea, Republic of)

2014-03-15

Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after {sup 18}F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast

Electrical properties of transparent CNT and ITO coatings on PET substrate including nano-structural aspects

Science.gov (United States)

Park, Joung-Man; Wang, Zuo-Jia; Kwon, Dong-Jun; Gu, Ga-Young; Lawrence DeVries, K.

2013-01-01

Ultraviolet (UV)-visible spectra and surface resistance measurement were used to investigate optical transmittance and conductive properties of carbon nanotube (CNT) and indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates. Conductive CNT and ITO coatings were successfully fabricated on PET by a spray-coating method. Thin coatings of both materials exhibited good conductivity and transparency. Changes in electrical and optical properties of the coatings were studied as a function of the coating suspension concentration. Interfacial durability of the coatings on PET substrates was also investigated under fatigue and bending loads. CNT coated substrates, with high aspect ratios, exhibited no detectable change in surface resistance up to 2000 cyclic loadings, whereas the ITO coated substrates exhibited a substantial increase in surface resistance at 1000 loading cycles. This change in resistance is attributed to a reduction in the number and effectiveness of the electrical contact points due to the inherent brittle nature of ITO.

Lung PET scan

Science.gov (United States)

... Chest PET scan; Lung positron emission tomography; PET - chest; PET - lung; PET - tumor imaging; ... Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. Philadelphia, ...

GPU-based optical propagation simulator of a laser-processed crystal block for the X'tal cube PET detector.

Science.gov (United States)

Ogata, Yuma; Ohnishi, Takashi; Moriya, Takahiro; Inadama, Naoko; Nishikido, Fumihiko; Yoshida, Eiji; Murayama, Hideo; Yamaya, Taiga; Haneishi, Hideaki

2014-01-01

The X'tal cube is a next-generation DOI detector for PET that we are developing to offer higher resolution and higher sensitivity than is available with present detectors. It is constructed from a cubic monolithic scintillation crystal and silicon photomultipliers which are coupled on various positions of the six surfaces of the cube. A laser-processing technique is applied to produce 3D optical boundaries composed of micro-cracks inside the monolithic scintillator crystal. The current configuration is based on an empirical trial of a laser-processed boundary. There is room to improve the spatial resolution by optimizing the setting of the laser-processed boundary. In fact, the laser-processing technique has high freedom in setting the parameters of the boundary such as size, pitch, and angle. Computer simulation can effectively optimize such parameters. In this study, to design optical characteristics properly for the laser-processed crystal, we developed a Monte Carlo simulator which can model arbitrary arrangements of laser-processed optical boundaries (LPBs). The optical characteristics of the LPBs were measured by use of a setup with a laser and a photo-diode, and then modeled in the simulator. The accuracy of the simulator was confirmed by comparison of position histograms obtained from the simulation and from experiments with a prototype detector composed of a cubic LYSO monolithic crystal with 6 × 6 × 6 segments and multi-pixel photon counters. Furthermore, the simulator was accelerated by parallel computing with general-purpose computing on a graphics processing unit. The calculation speed was about 400 times faster than that with a CPU.

Nondestructive Analysis of Apollo Samples by Micro-CT and Micro-XRF Analysis: A PET Style Examination

Science.gov (United States)

Zeigler, Ryan A.

2014-01-01

An integral part of any sample return mission is the initial description and classification of returned samples by the preliminary examination team (PET). The goal of a PET is to characterize and classify the returned samples, making this information available to the general research community who can then conduct more in-depth studies on the samples. A PET strives to minimize the impact their work has on the sample suite, which often limits the PET work to largely visual measurements and observations like optical microscopy. More modern techniques can also be utilized by future PET to nondestructively characterize astromaterials in a more rigorous way. Here we present our recent analyses of Apollo samples 14321 and 14305 by micro-CT and micro-XRF (respectively), assess the potential for discovery of "new" Apollo samples for scientific study, and evaluate the usefulness of these techniques in future PET efforts.

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

DEFF Research Database (Denmark)

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

2016-01-01

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

Positron Emission Tomography (PET)

International Nuclear Information System (INIS)

Welch, M.J.

1990-01-01

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs

Positron Emission Tomography (PET)

Science.gov (United States)

Welch, M. J.

1990-01-01

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

Positron Emission Tomography (PET)

Energy Technology Data Exchange (ETDEWEB)

Welch, M.J.

1990-01-01

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs.

FDG PET for therapy monitoring in Hodgkin and non-Hodgkin lymphomas

Energy Technology Data Exchange (ETDEWEB)

Barrington, Sally F. [St. Thomas' Hospital, PET Imaging Centre, King' s College London and Guy' s, King' s Health Partners, London (United Kingdom); Kluge, Regine [University Hospital of Leipzig, Department of Nuclear Medicine, Leipzig (Germany)

2017-08-15

PET using {sup 18}F-FDG for treatment monitoring in patients with lymphoma is one of the most well-developed clinical applications. PET/CT is nowadays used during treatment to assess chemosensitivity, with response-adapted therapy given according to 'interim' PET in clinical practice to adults and children with Hodgkin lymphoma. PET is also used to assess remission from disease and to predict prognosis in the pretransplant setting. Mature data have been reported for the common subtypes of aggressive B-cell lymphomas, with more recent data also supporting the use of PET for response assessment in T-cell lymphomas. The Deauville five-point scale incorporating the Deauville criteria (DC) is recommended for response assessment in international guidelines. FDG uptake is graded in relation to the reference regions of normal mediastinum and liver. The DC have been validated in most lymphoma subtypes. The DC permit the threshold for adequate or inadequate response to be adapted according to the clinical context or research question. It is important for PET readers to understand how the DC have been applied in response-adapted trials for correct interpretation and discussion with the multidisciplinary team. Quantitative methods to perform PET in standardized ways have also been developed which may further improve response assessment including a quantitative extension to the DC (qPET). This may have advantages in providing a continuous scale to refine the threshold for adequate/inadequate response in specific clinical situations or treatment optimization in trials. qPET is also less observer-dependent and limits the problem of optical misinterpretation due to the influence of background activity. (orig.)

Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

Energy Technology Data Exchange (ETDEWEB)

Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

2016-12-15

Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[{sup 18}F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases

Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

International Nuclear Information System (INIS)

Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh

2016-01-01

Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-["1"8F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases, the

PET and PET/CT in tumour of undetermined origin; PET y PET/CT en tumor de origen indeterminado

Energy Technology Data Exchange (ETDEWEB)

Garcia O, J R [Nuclear Medicine and Molecular Imaging, PET/CT, Centro Medico ABC, Mexico D.F. (Mexico)

2007-07-01

In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

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

Science.gov (United States)

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

2016-12-01

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

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

Science.gov (United States)

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

2014-12-01

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

Pet Allergy Quiz

Science.gov (United States)

... Treatments ▸ Allergies ▸ Pet Allergy ▸ Pet Allergy Quiz Share | Pet Allergy Quiz More than half of U.S. households ... cat family. Yet, millions of people suffer from pet allergies. Take this quiz to test your knowledge ...

Colorectal cancer staging: comparison of whole-body PET/CT and PET/MR.

Science.gov (United States)

Catalano, Onofrio A; Coutinho, Artur M; Sahani, Dushyant V; Vangel, Mark G; Gee, Michael S; Hahn, Peter F; Witzel, Thomas; Soricelli, Andrea; Salvatore, Marco; Catana, Ciprian; Mahmood, Umar; Rosen, Bruce R; Gervais, Debra

2017-04-01

Correct staging is imperative for colorectal cancer (CRC) since it influences both prognosis and management. Several imaging methods are used for this purpose, with variable performance. Positron emission tomography-magnetic resonance (PET/MR) is an innovative imaging technique recently employed for clinical application. The present study was undertaken to compare the staging accuracy of whole-body positron emission tomography-computed tomography (PET/CT) with whole-body PET/MR in patients with both newly diagnosed and treated colorectal cancer. Twenty-six patients, who underwent same day whole-body (WB) PET/CT and WB-PET/MR, were evaluated. PET/CT and 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. Correct staging was compared between methods using McNemar's Chi square test. The two methods were in agreement and correct for 18/26 (69%) patients, and in agreement and incorrect for one patient (3.8%). PET/MR and PET/CT stages for the remaining 7/26 patients (27%) were discordant, with PET/MR staging being correct in all seven cases. PET/MR significantly outperformed PET/CT overall for accurate staging (P = 0.02). PET/MR outperformed PET/CT in CRC staging. PET/MR might allow accurate local and distant staging of CRC patients during both at the time of diagnosis and during follow-up.

TOF-PET/MR和TOF-PET/CT在体部恶性肿瘤SUVmax值的比较%Comparision of SUVmax of TOF-PET/MR and TOF-PET/CT in body malignant tumor

Institute of Scientific and Technical Information of China (English)

宋天彬; 卢洁; 崔碧霄; 马杰; 杨宏伟; 马蕾; 梁志刚

2017-01-01

目的 探讨时间飞行(TOF)技术PET/CT和PET/MR检查体部恶性病变SUVmax值的一致性.方法 回顾性分析接受TOF-PET/CT和TOF-PET/MR检查的体部恶性肿瘤患者20例,分为先PET/CT后PET/MR组和先PET/MR后PET/CT组,每组10例.采用Bland-Altma图评价两次检查病灶SUVmax值的一致性,采用多因素方差分析评价扫描顺序和机器类型对病灶的SUVmax测量值的影响.结果 TOF-PET/CT与TOF-PET/MR检查病灶的SUVmax值有较好的一致性[先PET/CT后PET/MR组:均值差为3.06,95％CI(-7.5,13.6),先PET/MR后PET/CT组:均值差3.0,95％CI(-2.4,8.3)].扫描顺序对于恶性病灶的SUVmax有影响(F=46.00,P＜0.001),而机器类型对恶性病灶的SUVmax值无影响(F=0.005,P=0.95).结论 TOF-PET/MR和TOF-PET/CT在体部恶性病变SUVmax值测量方面具有相当的诊断价值,且延迟显像SUVmax的增加与采集时间有关,而与检查机器类型无关.%Objective To explore the consistency of time-of-flight (TOF) technology of PET/MRI and PET/CT for max standardized uptake value (SUVmax) of body malignant tumors.Methods A retrospective analysis of TOF-PET/CT and TOF-PET/MR imaging data about twenty patients with body malignant tumors was performed.Patients were divided into two groups (each n=10),including PET/CT first and sequentially PET/MR group and PET/MR first and sequentially PET/CT group.Bland-Altman figure was used to evaluate consistency of SUVmax of malignant lesions between TOF-PET/CT and TOF-PET/MR.Multi-way ANOVA was used to analysis effect of machine type and exam order on SUVmaxof malignant lesions in TOF-PET/CT and TOF-PET/MR.Results SUVmax of malignant lesions in TOF-PET/CT and TOF-PET/MR had good consistency in two groups (PET/CT first and sequentially PET/MR group:Mean difference was 3.06,95％CI was [-7.5,13.6];PET/MR first and sequentially PET/CT group:Mean difference was 3.0,95％CI was [-2.4,8.3]).SUVmax was not influenced by machine type (F=0.005,P=0.95),but exam order (F=46.00,P＜0

Dedicated brain PET system of PET/MR for brain research

International Nuclear Information System (INIS)

Cheng, Li; Liu, Yaqiang; Ma, Tianyu; Wang, Shi; Wei, Qingyang; Xu, Tianpeng

2015-01-01

This work is to replace PET ring in human brain PET/MR system with a dedicated wearable PET insert, aimed at improving both patient feasibility and system performance for brain imaging. The designed PET/MR system includes two parts: the inside parts, including a radio frequency (RF) coil and PET ring, are mounted on patient’s head, and the outside part, a MR imager, is dependent of patient. The RF coil is the innermost layer, surrounded by an outer PET-ring layer. They are supported by a MRcompatible structure. And both RF coil and PET detectors are placed inside a standard clinical 3-T MR imager. From the design of the system we can infer that some advantages can be achieved. First, high sensitivity will be achieved with the same amount crystals as the PET ring is more close to region-of-interest area, at a reduced cost. Second, by using a 2-layer depth of interaction (DOI) detector, the parallax effect can be minimized. The resolution will benefit from short positron range caused by magnetic field and smaller ring diameter will also reduce the effect of non-collinearity. Thirdly, as the PET ring is mounted on head, impact of patient motion will be reduced.

Dedicated brain PET system of PET/MR for brain research

Energy Technology Data Exchange (ETDEWEB)

Cheng, Li; Liu, Yaqiang; Ma, Tianyu; Wang, Shi; Wei, Qingyang; Xu, Tianpeng [Institute of Medical Physics, Department of Engineering Physics, Tsinghua University, Beijing (China)

2015-05-18

This work is to replace PET ring in human brain PET/MR system with a dedicated wearable PET insert, aimed at improving both patient feasibility and system performance for brain imaging. The designed PET/MR system includes two parts: the inside parts, including a radio frequency (RF) coil and PET ring, are mounted on patient’s head, and the outside part, a MR imager, is dependent of patient. The RF coil is the innermost layer, surrounded by an outer PET-ring layer. They are supported by a MRcompatible structure. And both RF coil and PET detectors are placed inside a standard clinical 3-T MR imager. From the design of the system we can infer that some advantages can be achieved. First, high sensitivity will be achieved with the same amount crystals as the PET ring is more close to region-of-interest area, at a reduced cost. Second, by using a 2-layer depth of interaction (DOI) detector, the parallax effect can be minimized. The resolution will benefit from short positron range caused by magnetic field and smaller ring diameter will also reduce the effect of non-collinearity. Thirdly, as the PET ring is mounted on head, impact of patient motion will be reduced.

PET/CT-guided Interventions: Personnel Radiation Dose

Energy Technology Data Exchange (ETDEWEB)

Ryan, E. Ronan, E-mail: ronan@ronanryan.com; Thornton, Raymond; Sofocleous, Constantinos T.; Erinjeri, Joseph P. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States); Hsu, Meier [Memorial Sloan-Kettering Cancer Center, Department of Epidemiology and Biostatistics (United States); Quinn, Brian; Dauer, Lawrence T. [Memorial Sloan-Kettering Cancer Center, Department of Medical Physics (United States); Solomon, Stephen B. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States)

2013-08-01

PurposeTo quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.MethodsIn this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).ResultsThe median effective dose was 0.02 (range 0-0.13) mSv for the primary operator, 0.01 (range 0-0.05) mSv for the nurse anesthetist, and 0.02 (range 0-0.05) mSv for the radiology technologist. The median extremity dose equivalent for the operator was 0.05 (range 0-0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).ConclusionThe operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient.

Effect of Attenuation Correction on Regional Quantification Between PET/MR and PET/CT

DEFF Research Database (Denmark)

Teuho, Jarmo; Johansson, Jarkko; Linden, Jani

2016-01-01

UNLABELLED: A spatial bias in brain PET/MR exists compared with PET/CT, because of MR-based attenuation correction. We performed an evaluation among 4 institutions, 3 PET/MR systems, and 4 PET/CT systems using an anthropomorphic brain phantom, hypothesizing that the spatial bias would be minimized....../MR systems, CTAC was applied as the reference method for attenuation correction. RESULTS: With CTAC, visual and quantitative differences between PET/MR and PET/CT systems were minimized. Intersystem variation between institutions was +3.42% to -3.29% in all VOIs for PET/CT and +2.15% to -4.50% in all VOIs...... for PET/MR. PET/MR systems differed by +2.34% to -2.21%, +2.04% to -2.08%, and -1.77% to -5.37% when compared with a PET/CT system at each institution, and these differences were not significant (P ≥ 0.05). CONCLUSION: Visual and quantitative differences between PET/MR and PET/CT systems can be minimized...

Quantitative PET imaging with the 3T MR-BrainPET

International Nuclear Information System (INIS)

Weirich, C.; Scheins, J.; Lohmann, P.; Tellmann, L.; Byars, L.; Michel, C.; Rota Kops, E.; Brenner, D.; Herzog, H.; Shah, N.J.

2013-01-01

The new hybrid imaging technology of MR-PET allows for simultaneous acquisition of versatile MRI contrasts and the quantitative metabolic imaging with PET. In order to achieve the quantification of PET images with minimal residual error the application of several corrections is crucial. In this work we present our results on quantification with the 3T MR BrainPET scanner

Brain PET scan

Science.gov (United States)

... results on a PET scan. Blood sugar or insulin levels may affect the test results in people with diabetes . PET scans may be done along with a CT scan. This combination scan is called a PET/CT. Alternative Names Brain positron emission tomography; PET scan - brain References Chernecky ...

Clinical PET application

Energy Technology Data Exchange (ETDEWEB)

Lim, Sang Moo; Hong, Song W.; Choi, Chang W.; Yang, Seong Dae [Korea Cancer Center Hospital, Seoul (Korea)

1997-12-01

PET gives various methabolic images, and is very important, new diagnostic modality in clinical oncology. In Korea Cancer Center Hospital, PET is installed as a research tool of long-mid-term atomic research project. For the efficient use of PET for clinical and research projects, income from the patients should be managed to get the raw material, equipment, manpower, and also for the clinical PET research. 1. Support the clinical application of PET in oncology. 2. Budgetary management of income, costs for raw material, equipment, manpower, and the clinical PET research project. In this year, 250 cases of PET images were obtained, which resulted total income of 180,000,000 won. 50,000,000 won was deposited for the 1998 PET clinical research. Second year PET clinical research should be managed under unified project. Increased demand for {sup 18}FDG in and outside KCCH need more than 2 times production of {sup 18}FDG in a day purchase of HPLC pump and {sup 68}Ga pin source which was delayed due to economic crisis, should be done early in 1998. (author). 2 figs., 3 tabs.

PET and PET/CT in oncology: the key of diagnostic challenge

International Nuclear Information System (INIS)

Mortelmans, L.; Stroobants, S.; Spaepen, K.

2004-01-01

In this presentation authors present use of positron emission tomography (PET) in oncology. This lecture is divided to the following parts: (1) Assessment of treatment response; (2) Treatment monitoring by PET: clinical examples; (3) PET for early response assessment; (4) Use of PET in Radiotherapy planning

'PET -Compton' system. Comparative evaluation with PET system using Monte Carlo simulation

International Nuclear Information System (INIS)

Diaz Garcia, Angelina; Arista Romeu, Eduardo; Abreu Alfonso, Yamiel; Leyva Fabelo, Antonio; Pinnera Hernandez, Ibrahin; Bolannos Perez, Lourdes; Rubio Rodriguez, Juan A; Perez Morales, Jose M.; Arce Dubois, Pedro; Vela Morales, Oscar; Willmott Zappacosta, Carlos

2011-01-01

Positron Emission Tomography (PET) in small animals has actually achieved spatial resolution round about 1 mm and currently there are under study different approaches to improve this spatial resolution. One of them combines PET technology with Compton Cameras. This paper presents the idea of the so called 'PET-Compton' systems and includes comparative evaluation of spatial resolution and global efficiency in both PET and PET-Compton system by means of Monte Carlo simulations using Geant4 code. Simulation is done on a PET-Compton system consisting of LYSO-LuYAP scintillating detectors of particular small animal PET scanner named 'Clear-PET' and for Compton detectors based on CdZnTe semiconductor. A group of radionuclides that emits a positron (e + ) and γ quantum almost simultaneously and fulfills some selection criteria for their possible use in PET-Compton systems for medical and biological applications were studied under simulation conditions. (Author)

PET-COMPTON System. Comparative evaluation with PET System using Monte Carlo Simulation

International Nuclear Information System (INIS)

Diaz Garcia, Angelina; Arista Romeu, Eduardo; Abreu Alfonso, Yamiel; Leyva Fabelo, Antonio; Pinnera HernAndez, Ibrahin; Bolannos Perez, Lourdes; Rubio Rodriguez, Juan A.; Perez Morales, Jose M.; Arce Dubois, Pedro; Vela Morales, Oscar; Willmott Zappacosta, Carlos

2012-01-01

Positron Emission Tomography (PET) in small animals has actually achieved spatial resolution round about 1 mm and currently there are under study different approaches to improve this spatial resolution. One of them combines PET technology with Compton Cameras. This paper presents the idea of the so called PET-Compton systems and has included comparative evaluation of spatial resolution and global efficiency in both PET and PET-Compton system by means of Monte Carlo simulations using Geant4 code. Simulation was done on a PET-Compton system made-up of LYSO-LuYAP scintillating detectors of particular small animal PET scanner named Clear-PET and for Compton detectors based on CdZnTe semiconductor. A group of radionuclides that emits a positron (e+) and quantum almost simultaneously and fulfills some selection criteria for their possible use in PET-Compton systems for medical and biological applications were studied under simulation conditions. By means of analytical reconstruction using SSRB (Single Slide Rebinning) method were obtained superior spatial resolution in PET-Compton system for all tested radionuclides (reaching sub-millimeter values of for 22Na source). However this analysis done by simulation have shown limited global efficiency values in PET-Compton system (in the order of 10 -5 -10 -6 %) instead of values around 5*10 -1 % that have been achieved in PET system. (author)

Comparison of dosimetry between PET/CT and PET alone using 11C-ITMM

International Nuclear Information System (INIS)

Ito, Kimiteru; Sakata, Muneyuki; Wagarsuma, Kei; Toyohara, Jun; Ishibashi, Kenji; Ishii, Kenji; Ishiwata, Kiichi; Oda, Keiichi

2016-01-01

We used a new tracer, N-[4-[6-(isopropylamino) pyrimidin-4-yl]-1,3-thiazol-2-yl]-4- 11 C-methoxy-N-methylbenzamide ( 11 C-ITMM), to compare radiation doses from positron emission tomography (PET)/computed tomography (CT) with previously published doses from PET alone. Twelve healthy volunteers [six males (mean age ± SD, 27.7 ± 6.7 years) and six females (31.8 ± 14.5 years)] in 12 examinations were recruited. Dose estimations from PET/CT were compared with those from PET alone. Regions of interest (ROIs) in PET/CT were delineated on the basis of low-dose CT (LD-CT) images acquired during PET/CT. Internal and external radiation doses were estimated using OLINDA/EXM 1.0 and CT-Expo software. The effective dose (ED) for 11 C-ITMM calculated from PET/CT was estimated to be 4.7 ± 0.5 μSv/MBq for the male subjects and 4.1 ± 0.7 μSv/MBq for the female subjects. The mean ED for 11 C-ITMM calculated from PET alone in a previous report was estimated to be 4.6 ± 0.3 μSv/MBq (males, n = 3). The ED values for 11 C-ITMM calculated from PET/CT in the male subjects were almost identical to those from PET alone. The absorbed doses (ADs) of the gallbladder, stomach, red bone marrow, and spleen calculated from PET/CT were significantly different from those calculated from PET alone. The EDs of 11 C-ITMM calculated from PET/CT were almost identical to those calculated from PET alone. The ADs in several organs calculated from PET/CT differed from those from PET alone. LD-CT images acquired during PET/CT may facilitate organ identification.

National Electrical Manufacturers Association NU-4 performance evaluation of the PET component of the NanoPET/CT preclinical PET/CT scanner.

Science.gov (United States)

Szanda, Istvan; Mackewn, Jane; Patay, Gergely; Major, Peter; Sunassee, Kavitha; Mullen, Gregory E; Nemeth, Gabor; Haemisch, York; Blower, Philip J; Marsden, Paul K

2011-11-01

The NanoPET/CT represents the latest generation of commercial preclinical PET/CT systems. This article presents a performance evaluation of the PET component of the system according to the National Electrical Manufacturers Association (NEMA) NU-4 2008 standard. The NanoPET/CT consists of 12 lutetium yttrium orthosilicate:cerium modular detectors forming 1 ring, with 9.5-cm axial coverage and a 16-cm animal port. Each detector crystal is 1.12 × 1.12 × 13 mm, and 1 module contains 81 × 39 of these crystals. An optical light guide transmits the scintillation light to the flat-panel multianode position-sensitive photomultiplier tubes. Analog-to-digital converter cards and a field-programmable gate array-based data-collecting card provide the readout. Spatial resolution, sensitivity, counting rate capabilities, and image quality were evaluated in accordance with the NEMA NU-4 standard. Energy and temporal resolution measurements and a mouse imaging study were performed in addition to the standard. Energy resolution was 19% at 511 keV. The spatial resolution, measured as full width at half maximum on single-slice rebinning/filtered backprojection-reconstructed images, approached 1 mm on the axis and remained below 2.5 mm in the central 5-cm transaxial region both in the axial center and at one-quarter field of view. The maximum absolute sensitivity for a point source at the center of the field of view was 7.7%. The maximum noise equivalent counting rates were 430 kcps at 36 MBq and 130 kcps at 27 MBq for the mouse- and rat-sized phantoms, respectively. The uniformity and recovery coefficients were measured with the image-quality phantom, giving good-quality images. In a mouse study with an (18)F-labeled thyroid-specific tracer, the 2 lobes of the thyroid were clearly distinguishable, despite the small size of this organ. The flexible readout system allowed experiments to be performed in an efficient manner, and the system remained stable throughout. The large number

Additional value of PET-CT in the staging of lung cancer: comparison with CT alone, PET alone and visual correlation of PET and CT

International Nuclear Information System (INIS)

Wever, W. de; Marchal, G.; Bogaert, J.; Verschakelen, J.A.; Ceyssens, S.; Mortelmans, L.; Stroobants, S.

2007-01-01

Integrated positron emission tomography (PET) and computed tomography (CT) is a new imaging modality offering anatomic and metabolic information. The purpose was to evaluate retrospectively the accuracy of integrated PET-CT in the staging of a suggestive lung lesion, comparing this with the accuracy of CT alone, PET alone and visually correlated PET-CT. Fifty patients undergoing integrated PET-CT for staging of a suggestive lung lesion were studied. Their tumor, node, metastasis (TNM) statuses were determined with CT, PET, visually correlated PET-CT and integrated PET-CT. These TNM stages were compared with the surgical TNM status. Integrated PET-CT was the most accurate imaging technique in the assessment of the TNM status. Integrated PET-CT predicted correctly the T status, N status, M status and TNM status in, respectively, 86%, 80%, 98%, 70% versus 68%, 66%,88%, 46% with CT, 46%, 70%, 96%, 30% with PET and 72%, 68%, 96%, 54% with visually correlated PET-CT. T status and N status were overstaged, respectively, in 8% and 16% with integrated PET-CT, in 20% and 28% with CT, in 16% and 20% with PET, in 12% and 20% with visually correlated PET-CT and understaged in 6% and 4% with integrated PET-CT, versus 12% and 6% with CT, 38% and 10% with PET and 12% with visually correlated PET-CT. Integrated PET-CT improves the staging of lung cancer through a better anatomic localization and characterization of lesions and is superior to CT alone and PET alone. If this technique is not available, visual correlation of PET and CT can be a valuable alternative. (orig.)

Pet-Related Infections.

Science.gov (United States)

Day, Michael J

2016-11-15

Physicians and veterinarians have many opportunities to partner in promoting the well-being of people and their pets, especially by addressing zoonotic diseases that may be transmitted between a pet and a human family member. Common cutaneous pet-acquired zoonoses are dermatophytosis (ringworm) and sarcoptic mange (scabies), which are both readily treated. Toxoplasmosis can be acquired from exposure to cat feces, but appropriate hygienic measures can minimize the risk to pregnant women. Persons who work with animals are at increased risk of acquiring bartonellosis (e.g., cat-scratch disease); control of cat fleas is essential to minimize the risk of these infections. People and their pets share a range of tick-borne diseases, and exposure risk can be minimized with use of tick repellent, prompt tick removal, and appropriate tick control measures for pets. Pets such as reptiles, amphibians, and backyard poultry pose a risk of transmitting Salmonella species and are becoming more popular. Personal hygiene after interacting with these pets is crucial to prevent Salmonella infections. Leptospirosis is more often acquired from wildlife than infected dogs, but at-risk dogs can be protected with vaccination. The clinical history in the primary care office should routinely include questions about pets and occupational or other exposure to pet animals. Control and prevention of zoonoses are best achieved by enhancing communication between physicians and veterinarians to ensure patients know the risks of and how to prevent zoonoses in themselves, their pets, and other people.

Twelve automated thresholding methods for segmentation of PET images: a phantom study

International Nuclear Information System (INIS)

Prieto, Elena; Peñuelas, Iván; Martí-Climent, Josep M; Lecumberri, Pablo; Gómez, Marisol; Pagola, Miguel; Bilbao, Izaskun; Ecay, Margarita

2012-01-01

Tumor volume delineation over positron emission tomography (PET) images is of great interest for proper diagnosis and therapy planning. However, standard segmentation techniques (manual or semi-automated) are operator dependent and time consuming while fully automated procedures are cumbersome or require complex mathematical development. The aim of this study was to segment PET images in a fully automated way by implementing a set of 12 automated thresholding algorithms, classical in the fields of optical character recognition, tissue engineering or non-destructive testing images in high-tech structures. Automated thresholding algorithms select a specific threshold for each image without any a priori spatial information of the segmented object or any special calibration of the tomograph, as opposed to usual thresholding methods for PET. Spherical 18 F-filled objects of different volumes were acquired on clinical PET/CT and on a small animal PET scanner, with three different signal-to-background ratios. Images were segmented with 12 automatic thresholding algorithms and results were compared with the standard segmentation reference, a threshold at 42% of the maximum uptake. Ridler and Ramesh thresholding algorithms based on clustering and histogram-shape information, respectively, provided better results that the classical 42%-based threshold (p < 0.05). We have herein demonstrated that fully automated thresholding algorithms can provide better results than classical PET segmentation tools. (paper)

PET and PET-CT. State of the art and future prospects

International Nuclear Information System (INIS)

Fanti, Stefano; Franchi, Roberto; Battista, Giuseppe; Monetti, Nino; Canini, Romeo

2005-01-01

Fluoro-deoxyglucose positron emission tomography (FDG PET) enables the in vivo study of tissue metabolism, and thus is able to identify malignant tumours as hypermetabolic lesions by an increase in tracer uptake. Many papers have demonstrated both the relevant impact of FDG PET on staging of many cancers and the superior accuracy of the technique compared with conventional diagnostic methods for pre-treatment evaluation, therapy response evaluation and relapse identification. In particular PET was found useful in identifying lymph nodal and metastatic spread. thus altering patient management in more than 30% of cases. PET images, however, provide limited anatomical data, which in regions such as the head and neck, mediastinum and pelvic cavity is a significant drawback. The exact localization of lesions may also be difficult in some cases, on the basis of PET images alone. The introduction of combined PET-computed tomography (PET-CT) scanners enables the almost simultaneous acquisition of transmission and emission images, thus obtaining optimal fusion images in a very short time. PET-CT fusion images enable lesions to be located, reducing false positive studies and increasing accuracy; the overall duration of examination may also be reduced. On the basis of both literature data and our experience we established the clinical indications when PET-CT may be particularly useful, in comparison with PET alone. It should also be underlined that the use of PET-CT is almost mandatory for new traces such as C-choline and C-methionine; these new tracers may be applied for studying tumours not assessable with FDG, such as prostate cancer. In conclusion PET-CT is at present the most advanced method for metabolic imaging, and is capable of precisely localizing and assessing tumours; fusion images reduce false positive and inconclusive studies, thus increasing diagnostic accuracy [it

Development of PET insert for simultaneous PET/MR imaging of human brain

Energy Technology Data Exchange (ETDEWEB)

Jung, Jiwoong; Choi, Yong; Jung, Jin Ho; Kim, Sangsu; Im, Ki Chun; Lim, Hyun Keong [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Oh, Changheun; Park, HyunWook; Cho, Gyuseong [Departments of Electrical Engineering and Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of)

2014-07-29

Recently, there has been great interest on the development of combined PET/MR, which is a useful tool for both functional and anatomic imaging. The purpose of this study was to develop a MR compatible PET insert for simultaneous PET and MR imaging of human brain and to evaluate the performance of the hybrid PET-MRI. The PET insert consisted of 18 detector blocks arranged in a ring of 390 mm diameter with 60 mm axial FOV. Each detector block was composed of 4 × 4 matrix of detector modules, each of which consisted of a 4 × 4 array LYSO coupled to a 4 × 4 GAPD array. The PET gantry was shielded with gold-plated conductive fabric tapes. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuits (PDCs) and then transferred to FPGA-embedded DAQ modules. The PDCs and DAQ modules were enclosed in an aluminum box and located at the rear of the MR bore inside MRI room. 3-T human MRIs of two different vendors were used to evaluate the MR compatibility of developed PET insert. No significant changes of the PET performance and the homogeneity of MR images caused by the non-compatibility of PET-MRI were observed with the 2 different MRIs. The signal intensities of MR images were slightly degraded (<3.6%) with the both MRI systems. The difference between independently and simultaneously acquired PET images of brain phantom was negligibly small (<4.3%). High quality simultaneous brain PET and MRI of 3 normal volunteers were successfully acquired. Experimental results indicate that the high performance compact and lightweight PET insert for hybrid PET/MRI, which could be utilized with the MRI from various manufactures, can be developed using GAPD arrays and charge signal transmission method proposed in this study.

PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

Energy Technology Data Exchange (ETDEWEB)

Queiroz, Marcelo A.; Schulthess, Gustav von; Veit-Haibach, Patrick [University Hospital Zurich, Department Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department Medical Radiology, Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Zurich (Switzerland); Kubik-Huch, Rahel A.; Freiwald-Chilla, Bianka [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); Hauser, Nik [Kantonsspital Baden AG, Department of Gynaecology, Baden (Switzerland); Froehlich, Johannes M. [Guerbet AG, Zurich (Switzerland)

2015-08-15

To compare the diagnostic accuracy of PET/MRI and PET/CT for staging and re-staging advanced gynaecological cancer patients as well as identify the potential benefits of each method in such a population. Twenty-six patients with suspicious or proven advanced gynaecological cancer (12 ovarian, seven cervical, one vulvar and four endometrial tumours, one uterine metastasis, and one primary peritoneal cancer) underwent whole-body imaging with a sequential trimodality PET/CT/MR system. Images were analysed regarding primary tumour detection and delineation, loco-regional lymph node staging, and abdominal/extra-abdominal distant metastasis detection (last only by PET/CT). Eighteen (69.2 %) patients underwent PET/MRI for primary staging and eight patients (30.8 %) for re-staging their gynaecological malignancies. For primary tumour delineation, PET/MRI accuracy was statistically superior to PET/CT (p < 0.001). Among the different types of cancer, PET/MRI presented better tumour delineation mainly for cervical (6/7) and endometrial (2/3) cancers. PET/MRI for local evaluation as well as PET/CT for extra-abdominal metastases had therapeutic consequences in three and one patients, respectively. PET/CT detected 12 extra-abdominal distant metastases in 26 patients. PET/MRI is superior to PET/CT for primary tumour delineation. No differences were found in detection of regional lymph node involvement and abdominal metastases detection. (orig.)

Comparative analysis of PET/CT and PET/MR image characteristics of head and neck squamous cell carcinoma%对比分析头颈部鳞状细胞癌PET/CT与PET/MR特征

Institute of Scientific and Technical Information of China (English)

白乐; 程勇; 唐勇进; 凌雪英

2017-01-01

Objective To investigate PET/CT and PET/MR characteristics of head and neck squamous cell carcinoma (HNSCC).Methods Totally 40 patients with HNSCC underwent whole body 18F-FDG PET/CT and MR scans of head and neck before anti-tumor treatment.PET positive lesions of HNSCC,including primary lesions and lymph nodes were evaluated by 2 radiologists independently.Then the imaging quality,fusion quality,lesion conspicuity and lesion characteristics were assessed based on PET/CT,PET/MR T1WI and PET/MR T2WI.Results Ninety PET positive lesions in all 40patients were evaluated,including 40 primary lesions and 50 lymph nodes.Similar imaging quality and fusion quality of PET/CT,PET/MR T1WI and PET/MR T2WI were obtained without statistical difference (both P＞0.05).For the lesion conspicuity,PET/MR T1WI and PET/MR T2WI demonstrated significantly better than PET/CT in positive primary lesions and lymph nodes (all P＜0.05).For the characteristics of positive primary lesions,PET/MR T2WI provided more information than PET/CT in 29 lesions,equal to PET/CT in 4 lesions,and less than PET/CT in 7 lesions.Conclusion The application of PET/MR in HNSCC is feasible,being superior to PET/CT in indication of lesions in head and neck area.%目的 探讨头颈部鳞状细胞癌(HNSCC)的PET/CT及PET/MR特征.方法 纳入未经抗肿瘤治疗的头颈部鳞状细胞癌患者40例,所有患者均接受PET/CT及头颈部MR检查.由2名观察者独立观察PET阳性病灶,包括阳性原发灶及阳性淋巴结;并对PET/CT、PET/MR T1WI及PET/MR T2WI的图像质量、融合准确度、病灶清晰度、病灶特征等进行评分.分析2名观察者间的一致性.结果 40例患者共90个PET阳性病灶,包括阳性原发灶40个、阳性淋巴结50个.PET/CT、PET/MR T1WI及PET/MR T2WI在图像质量及融合准确度方面差异均无统计学意义(P均＞0.05);在显示阳性原发灶及阳性淋巴结的清晰度方面,PET/MR T1WI及PET/MR T2WI均优于PET/CT(P均＜0.05).40个阳性原发灶中,PET

Present and future of PET and PET/CT in gynaecologic malignancies

International Nuclear Information System (INIS)

Musto, Alessandra; Rampin, Lucia; Nanni, Cristina; Marzola, Maria Cristina; Fanti, Stefano; Rubello, Domenico

2011-01-01

Objectives: To review the published data in literature on patients affected by gynaecological malignancies to establish the role of 18 F-FDG positron emission tomography (PET) and PET/CT in comparison to conventional imaging (CI). Materials and methods: All papers specifically addressed to the role of 18 F-FDG PET and PET/CT in gynaecological malignancies published on PubMed/Medline, in abstracts from the principal international congresses, in the guidelines from national Societies that had appeared in literature until November 2009 were considered for the purpose of the present study. Results and conclusions: The use of 18 F-FDG PET, and even more of 18 F-FDG PET/CT, is increasing in the follow up of patients with gynaecologic malignancies and suspected recurrent disease: there is evidence in the literature that 18 F-FDG PET/CT has a higher sensitivity than CI in depicting occult metastatic spread. An interesting issue is represented by patients with ovarian cancer with an increase of the specific biomarker, CA-125, and negative/inconclusive findings at CI. The use of 18 F-FDG PET in differential diagnosis and staging is more controversial, but there is some evidence that a baseline PET examination performed before commencing therapy, for staging purpose, is also useful to evaluate the response to chemoradiation treatment. In several papers it has been suggested a relevant role of 18 F-FDG PET/CT in evaluating the entity of response to treatment and therefore to plan the subsequent therapeutic strategy.

Comparison of rCBF between patients with medial temporal lobe epilepsy and normal controls using H215O PET

International Nuclear Information System (INIS)

Kang, Eun Joo; Lee, Jae Sung; Nam, Hyun Woo; Lee, Sang Kun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul

2002-01-01

The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H 2 15 O-PET. 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Duirng the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Epilepsy induced changes were found not only in relative increase/ decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period

PET/CT-guided Interventions: Personnel Radiation Dose

International Nuclear Information System (INIS)

Ryan, E. Ronan; Thornton, Raymond; Sofocleous, Constantinos T.; Erinjeri, Joseph P.; Hsu, Meier; Quinn, Brian; Dauer, Lawrence T.; Solomon, Stephen B.

2013-01-01

PurposeTo quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.MethodsIn this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).ResultsThe median effective dose was 0.02 (range 0–0.13) mSv for the primary operator, 0.01 (range 0–0.05) mSv for the nurse anesthetist, and 0.02 (range 0–0.05) mSv for the radiology technologist. The median extremity dose equivalent for the operator was 0.05 (range 0–0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).ConclusionThe operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient

Head and neck imaging with PET and PET/CT: artefacts from dental metallic implants

International Nuclear Information System (INIS)

Goerres, Gerhard W.; Hany, Thomas F.; Kamel, Ehab; Schulthess von, Gustav K.; Buck, Alfred

2002-01-01

Germanium-68 based attenuation correction (PET Ge68 ) is performed in positron emission tomography (PET) imaging for quantitative measurements. With the recent introduction of combined in-line PET/CT scanners, CT data can be used for attenuation correction. Since dental implants can cause artefacts in CT images, CT-based attenuation correction (PET CT ) may induce artefacts in PET images. The purpose of this study was to evaluate the influence of dental metallic artwork on the quality of PET images by comparing non-corrected images and images attenuation corrected by PET Ge68 and PET CT . Imaging was performed on a novel in-line PET/CT system using a 40-mAs scan for PET CT in 41 consecutive patients with high suspicion of malignant or inflammatory disease. In 17 patients, additional PET Ge68 images were acquired in the same imaging session. Visual analysis of fluorine-18 fluorodeoxyglucose (FDG) distribution in several regions of the head and neck was scored on a 4-point scale in comparison with normal grey matter of the brain in the corresponding PET images. In addition, artefacts adjacent to dental metallic artwork were evaluated. A significant difference in image quality scoring was found only for the lips and the tip of the nose, which appeared darker on non-corrected than on corrected PET images. In 33 patients, artefacts were seen on CT, and in 28 of these patients, artefacts were also seen on PET imaging. In eight patients without implants, artefacts were seen neither on CT nor on PET images. Direct comparison of PET Ge68 and PET CT images showed a different appearance of artefacts in 3 of 17 patients. Malignant lesions were equally well visible using both transmission correction methods. Dental implants, non-removable bridgework etc. can cause artefacts in attenuation-corrected images using either a conventional 68 Ge transmission source or the CT scan obtained with a combined PET/CT camera. We recommend that the non-attenuation-corrected PET images also be

Covalent Binding of Heparin to Functionalized PET Materials for Improved Haemocompatibility

Directory of Open Access Journals (Sweden)

Metod Kolar

2015-03-01

Full Text Available The hemocompatibility of vascular grafts made from poly(ethylene terephthalate (PET is insufficient due to the rapid adhesion and activation of blood platelets that occur upon incubation with whole blood. PET polymer was treated with NHx radicals created by passing ammonia through gaseous plasma formed by a microwave discharge, which allowed for functionalization with amino groups. X-ray photoelectron spectroscopy characterization using derivatization with 4-chlorobenzaldehyde indicated that approximately 4% of the –NH2 groups were associated with the PET surface after treatment with the gaseous radicals. The functionalized polymers were coated with an ultra-thin layer of heparin and incubated with fresh blood. The free-hemoglobin technique, which is based on the haemolysis of erythrocytes, indicated improved hemocompatibility, which was confirmed by imaging the samples using confocal optical microscopy. A significant decrease in number of adhered platelets was observed on such samples. Proliferation of both human umbilical vein endothelial cells and human microvascular endothelial cells was enhanced on treated polymers, especially after a few hours of cell seeding. Thus, the technique represents a promising substitute for wet-chemical modification of PET materials prior to coating with heparin.

{sup 18}F-FDG PET and PET/CT in Burkitt's lymphoma

Energy Technology Data Exchange (ETDEWEB)

Karantanis, Dimitrios, E-mail: dkarantanis@nuclmed.ne [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States); Durski, Jolanta M.; Lowe, Val J.; Nathan, Mark A.; Mullan, Brian P. [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States); Georgiou, Evangelos [Medical Physics Department, Medical School, University of Athens (Greece); Johnston, Patrick B. [Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN (United States); Wiseman, Gregory A. [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States)

2010-07-15

Objective: To explore the value of {sup 18}F fluorodeoxy-glucose (FDG) positron emission tomography (PET) in Burkitt's lymphoma. Methods: All Burkitt's lymphoma patients referred for FDG PET or FDG PET/computed tomography (CT) exams at our institution from June 2003 to June 2006 were included. Selected patients were followed and clinical information was reviewed retrospectively. Results from FDG PET-PET/CT, as blindly reviewed by a consensus of two experienced readers, were compared with the status of the disease as determined by other laboratory, clinical and imaging exams and clinical follow-up. FDG PET-PET/CT results were classified as true positive or negative and false positive or negative. The degree of FDG uptake in the positive lesions was semiquantified as maximum standard uptake value (SUVmax). Results: Fifty-seven FDG PET-PET/CT exams were done in 15 patients. Seven exams were done for initial staging, 8 during and 14 after the completion of therapy, and 28 for disease surveillance. For nodal disease FDG PET-PET/CT was true positive in 8, true negative in 47 and false positive in 2 exams (sensitivity 100%, specificity 96%). For extranodal disease FDG PET-PET/CT was true positive in 6, true negative in 48 and false positive in 3 exams (sensitivity 100%, specificity 94%). The mean SUVmax for the positive nodal lesions was 15.7 (range 6.9-21.7, median 18.5) and for extranodal lesions was 14.2 (range 6.2-24.3, median 12.4). Conclusions: FDG PET-PET/CT is sensitive for the detection of viable disease in Burkitt's lymphoma. Affected areas demonstrated high degree of uptake that was reversible upon successful implementation of treatment.

Standardised uptake values from PET/CT images: comparison with conventional attenuation-corrected PET

International Nuclear Information System (INIS)

Souvatzoglou, M.; Ziegler, S.I.; Martinez, M.J.; Dzewas, G.; Schwaiger, M.; Bengel, F.; Busch, R.

2007-01-01

In PET/CT, CT-derived attenuation factors may influence standardised uptake values (SUVs) in tumour lesions and organs when compared with stand-alone PET. Therefore, we compared PET/CT-derived SUVs intra-individually in various organs and tumour lesions with stand-alone PET-derived SUVs. Thirty-five patients with known or suspected cancer were prospectively included. Sixteen patients underwent FDG PET using an ECAT HR+scanner, and subsequently a second scan using a Biograph Sensation 16PET/CT scanner. Nineteen patients were scanned in the reverse order. All images were reconstructed with an iterative algorithm (OSEM). Suspected lesions were grouped as paradiaphragmatic versus distant from the diaphragm. Mean and maximum SUVs were also calculated for brain, lung, liver, spleen and vertebral bone. The attenuation coefficients (μ values) used for correction of emission data (bone, soft tissue, lung) in the two data sets were determined. A body phantom containing six hot spheres and one cold cylinder was measured using the same protocol as in patients. Forty-six lesions were identified. There was a significant correlation of maximum and mean SUVs derived from PET and PET/CT for 14 paradiaphragmatic lesions (r=0.97 respectively; p<0.001 respectively) and for 32 lesions located distant from the diaphragm (r=0.87 and r=0.89 respectively; p<0.001 respectively). No significant differences were observed in the SUVs calculated with PET and PET/CT in the lesions or in the organs. In the phantom, radioactivity concentration in spheres calculated from PET and from PET/CT correlated significantly (r=0.99; p<0.001). SUVs of cancer lesions and normal organs were comparable between PET and PET/CT, supporting the usefulness of PET/CT-derived SUVs for quantification of tumour metabolism. (orig.)

Present and future of PET and PET/CT in gynaecologic malignancies

Energy Technology Data Exchange (ETDEWEB)

Musto, Alessandra [Department of Nuclear Medicine, PET Center, Policlinico Sant' Orsola Malpighi, Bologna University, Bologna (Italy); Rampin, Lucia [Department of Nuclear Medicine, PET Center, Radiology, Medical Physics, Santa Maria della Misericordia Hospital, viale tre martiri 140, 45100 Rovigo (Italy); Nanni, Cristina [Department of Nuclear Medicine, PET Center, Policlinico Sant' Orsola Malpighi, Bologna University, Bologna (Italy); Marzola, Maria Cristina [Department of Nuclear Medicine, PET Center, Radiology, Medical Physics, Santa Maria della Misericordia Hospital, viale tre martiri 140, 45100 Rovigo (Italy); Fanti, Stefano [Department of Nuclear Medicine, PET Center, Policlinico Sant' Orsola Malpighi, Bologna University, Bologna (Italy); Rubello, Domenico, E-mail: domenico.rubello@libero.it [Department of Nuclear Medicine, PET Center, Radiology, Medical Physics, Santa Maria della Misericordia Hospital, viale tre martiri 140, 45100 Rovigo (Italy)

2011-04-15

Objectives: To review the published data in literature on patients affected by gynaecological malignancies to establish the role of {sup 18}F-FDG positron emission tomography (PET) and PET/CT in comparison to conventional imaging (CI). Materials and methods: All papers specifically addressed to the role of {sup 18}F-FDG PET and PET/CT in gynaecological malignancies published on PubMed/Medline, in abstracts from the principal international congresses, in the guidelines from national Societies that had appeared in literature until November 2009 were considered for the purpose of the present study. Results and conclusions: The use of {sup 18}F-FDG PET, and even more of {sup 18}F-FDG PET/CT, is increasing in the follow up of patients with gynaecologic malignancies and suspected recurrent disease: there is evidence in the literature that {sup 18}F-FDG PET/CT has a higher sensitivity than CI in depicting occult metastatic spread. An interesting issue is represented by patients with ovarian cancer with an increase of the specific biomarker, CA-125, and negative/inconclusive findings at CI. The use of {sup 18}F-FDG PET in differential diagnosis and staging is more controversial, but there is some evidence that a baseline PET examination performed before commencing therapy, for staging purpose, is also useful to evaluate the response to chemoradiation treatment. In several papers it has been suggested a relevant role of {sup 18}F-FDG PET/CT in evaluating the entity of response to treatment and therefore to plan the subsequent therapeutic strategy.

Quantitative and Visual Assessments toward Potential Sub-mSv or Ultrafast FDG PET Using High-Sensitivity TOF PET in PET/MRI.

Science.gov (United States)

Behr, Spencer C; Bahroos, Emma; Hawkins, Randall A; Nardo, Lorenzo; Ravanfar, Vahid; Capbarat, Emily V; Seo, Youngho

2018-06-01

Newer high-performance time-of-flight (TOF) positron emission tomography (PET) systems have the capability to preserve diagnostic image quality with low count density, while maintaining a high raw photon detection sensitivity that would allow for a reduction in injected dose or rapid data acquisition. To assess this, we performed quantitative and visual assessments of the PET images acquired using a highly sensitive (23.3 cps/kBq) large field of view (25-cm axial) silicon photomultiplier (SiPM)-based TOF PET (400-ps timing resolution) integrated with 3 T-MRI in comparison to PET images acquired on non-TOF PET/x-ray computed tomography (CT) systems. Whole-body 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) PET/CT was acquired for 15 patients followed by whole body PET/magnetic resonance imaging (MRI) with an average injected dose of 325 ± 84 MBq. The PET list mode data from PET/MRI were reconstructed using full datasets (4 min/bed) and reduced datasets (2, 1, 0.5, and 0.25 min/bed). Qualitative assessment between PET/CT and PET/MR images were made. A Likert-type scale between 1 and 5, 1 for non-diagnostic, 3 equivalent to PET/CT, and 5 superior quality, was used. Maximum and mean standardized uptake values (SUV max and SUV mean ) of normal tissues and lesions detected were measured and compared. Mean visual assessment scores were 3.54 ± 0.32, 3.62 ± 0.38, and 3.69 ± 0.35 for the brain and 3.05 ± 0.49, 3.71 ± 0.45, and 4.14 ± 0.44 for the whole-body maximum intensity projections (MIPs) for 1, 2, and 4 min/bed PET/MR images, respectively. The SUV mean values for normal tissues were lower and statistically significant for images acquired at 4, 2, 1, 0.5, and 0.25 min/bed on the PET/MR, with values of - 18 ± 28 % (p PET/MR datasets. High-sensitivity TOF PET showed comparable but still better visual image quality even at a much reduced activity in comparison to lower-sensitivity non-TOF PET. Our data translates to a seven times

Imaging with 124I in differentiated thyroid carcinoma: is PET/MRI superior to PET/CT?

International Nuclear Information System (INIS)

Binse, I.; Poeppel, T.D.; Ruhlmann, M.; Gomez, B.; Bockisch, A.; Rosenbaum-Krumme, S.J.; Umutlu, L.

2016-01-01

The aim of this study was to compare integrated PET/CT and PET/MRI for their usefulness in detecting and categorizing cervical iodine-positive lesions in patients with differentiated thyroid cancer using 124 I as tracer. The study group comprised 65 patients at high risk of iodine-positive metastasis who underwent PET/CT (low-dose CT scan, PET acquisition time 2 min; PET/CT 2 ) followed by PET/MRI of the neck 24 h after 124 I administration. PET images from both modalities were analysed for the numbers of tracer-positive lesions. Two different acquisition times were used for the comparisons, one matching the PET/CT 2 acquisition time (2 min, PET/MRI 2 ) and the other covering the whole MRI scan time (30 min, PET/MRI 30 ). Iodine-positive lesions were categorized as metastasis, thyroid remnant or inconclusive according to their location on the PET/CT images. Morphological information provided by MRI was considered for evaluation of lesions on PET/MRI and for volume information. PET/MRI 2 detected significantly more iodine-positive metastases and thyroid remnants than PET/CT 2 (72 vs. 60, p = 0.002, and 100 vs. 80, p = 0.001, respectively), but the numbers of patients with at least one tumour lesion identified were not significantly different (21/65 vs. 17/65 patients). PET/MRI 30 tended to detect more PET-positive metastases than PET/MRI 2 (88 vs. 72), but the difference was not significant (p = 0.07). Of 21 lesions classified as inconclusive on PET/CT, 5 were assigned to metastasis or thyroid remnant when evaluated by PET/MRI. Volume information was available in 34 % of iodine-positive metastases and 2 % of thyroid remnants on PET/MRI. PET/MRI of the neck was found to be superior to PET/CT in detecting iodine-positive lesions. This was attributed to the higher sensitivity of the PET component, Although helpful in some cases, we found no substantial advantage of PET/MRI over PET/CT in categorizing iodine-positive lesions as either metastasis or thyroid remnant

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

Science.gov (United States)

Rakvongthai, Yothin; El Fakhri, Georges

2017-07-01

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

New DOI identification approach for high-resolution PET detectors

International Nuclear Information System (INIS)

Choghadi, Amin; Takahashi, Hiroyuki; Shimazoe, Kenji

2016-01-01

Depth-of-interaction (DOI) Identification in positron emission tomography (PET) detectors is getting importance as it improves spatial resolution in both conventional and time-of-flight (TOF) PET, and coincidence time resolution (CTR) in TOF-PET. In both prototypes, spatial resolution is affected by parallax error caused by length of scintillator crystals. This long length also contributes substantial timing uncertainty to the time resolution of TOF-PET. Through DOI identification, both parallax error and the timing uncertainty caused by the length of crystal can be resolved. In this work, a novel approach to estimate DOI was investigated, enjoying the interference of absorbance spectrum of scintillator crystals with their emission spectrum. Because the absorption length is close to zero for shorter wavelengths of crystal emission spectrum, the counts in this range of spectrum highly depend on DOI; that is, higher counts corresponds to deeper interactions. The ratio of counts in this range to the total counts is a good measure to estimate DOI. In order to extract such ratio, two photodetectors for each crystal are used and an optical filter is mounted only on top of one of them. The ratio of filtered output to non-filtered output can be utilized as DOI estimator. For a 2×2×20 mm 3 GAGG:Ce scintillator, 8-mm DOI resolution achieved in our simulations. (author)

Sensory analysis of pet foods.

Science.gov (United States)

Koppel, Kadri

2014-08-01

Pet food palatability depends first and foremost on the pet and is related to the pet food sensory properties such as aroma, texture and flavor. Sensory analysis of pet foods may be conducted by humans via descriptive or hedonic analysis, pets via acceptance or preference tests, and through a number of instrumental analysis methods. Sensory analysis of pet foods provides additional information on reasons behind palatable and unpalatable foods as pets lack linguistic capabilities. Furthermore, sensory analysis may be combined with other types of information such as personality and environment factors to increase understanding of acceptable pet foods. Most pet food flavor research is proprietary and, thus, there are a limited number of publications available. Funding opportunities for pet food studies would increase research and publications and this would help raise public awareness of pet food related issues. This mini-review addresses current pet food sensory analysis literature and discusses future challenges and possibilities. © 2014 Society of Chemical Industry.

The application of PET and PET-CT in cervical cancer

International Nuclear Information System (INIS)

Huang Jianmin; Pan Liping; Li Dongxue

2007-01-01

Cervical cancer is the common malignancies in woman, 18 F-fluorodeoxyglucose ( 18 F-FDG) PET is a well-established method for detecting, staging, cancer recurrence, therapeutic response and prognosis of cervical cancer. PET-CT can accurately locate the anatomical sites of tracer uptake and improve the diagnostic accuraccy of PET. (authors)

The petit rat (pet/pet), a new semilethal mutant dwarf rat with thymic and testicular anomalies.

Science.gov (United States)

Chiba, Junko; Suzuki, Katsushi; Suzuki, Hiroetsu

2008-12-01

The petit rat (pet/pet) is a recently discovered semilethal mutant dwarf. The neonatal pet/pet rats had a low body weight and small thymus and testis. During the first 3 d after birth, 50% of the male and 80% of the female pet/pet pups were lost or found dead. Surviving pet/pet rats showed marked retardation of postnatal growth, and their body weights were 41% (female rats) and 32% (male rats) of those of normal rats at the adult stage. The pet/pet rats exhibited proportional dwarfism, and their longitudinal bones were shorter than those of controls without skeletal malformations. Most organs of male pet/pet rats, especially the thymus, testis, adipose tissue surrounding the kidney, and accessory sex organs, weighed markedly less at 140 d of age than did those of their normal counterparts. The thymus of pet/pet rats was small with abnormal thymic follicles. Testes from pet/pet rats exhibited 2 patterns of abnormal histology. Spermatogenesis was present in testes that were only slightly anomalous, but the seminiferous tubules were reduced in diameter. In severely affected testes, most of the seminiferous tubules showed degeneration, and interstitial tissue was increased. Plasma growth hormone concentrations did not differ between pet/pet and normal male rats. The dwarf phenotype of pet/pet rats was inherited as an autosomal recessive trait. These results indicate that the pet/pet rat has a semilethal growth-hormone-independent dwarf phenotype that is accompanied by thymic and testicular anomalies and low birth weight.

Value of PET and PET-CT for monitoring tumor therapy

International Nuclear Information System (INIS)

Chen Xiang; Zhao Jinhua

2007-01-01

18 F-fluorodeoxyglucose ( 18 F-FDG) PET or PET-CT is an accurate test for differentiating residual viable tumor tissue from therapy-induced changes in tumor. Furthermore, quantitative assessment of therapy-induced changes in tumor 18 F-FDG uptake may allow the prediction of tumor response. Treatment may be adjusted according to tumor response. So it is increasingly used to monitor tumor response in patients undergoing chemotherapy and chemoradiotherapy. Here we focused on practical aspects of 18 F-FDG PET or PET-CT for treatment monitoring and on the existing advantages and challenges. (authors)

Processing and characterization of extruded PET and its r-PET and ...

Indian Academy of Sciences (India)

of r-PET and r-PET+ MWCNT fillers was obtained by the precipitation method using TFA as a solvent and acetone ... crystallinity in r-PET and decrease in chain entanglements. ..... insufficient to supply the complete information of the surface.

PET and PET/CT in tumour of undetermined origin

International Nuclear Information System (INIS)

Garcia O, J.R.

2007-01-01

In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

Clinical applications of PET/CT

International Nuclear Information System (INIS)

Le Ngoc Ha

2011-01-01

The purpose of this article is to review the evolution of PET, PET/CT focusing on the technical aspects, PET radiopharmaceutical developments and current clinical applications as well. The newest technologic advances have been reviewed, including improved crystal design, acquisition modes, reconstruction algorithms, etc. These advancements will continue to improve contrast, decrease noise, and increase resolution. Combined PET/CT system provides faster attenuation correction and useful anatomic correlation to PET functional information. A number of new radiopharmaceuticals used for PET imaging have been developed, however, FDG have been considered as the principal PET radiotracer. The current clinical applications of PET and PET/CT are widespread and include oncology, cardiology and neurology. (author)

Diagnosis and dosimetry in differentiated thyroid carcinoma using 124I PET: comparison of PET/MRI vs PET/CT of the neck

International Nuclear Information System (INIS)

Nagarajah, James; Jentzen, Walter; Hartung, Verena; Rosenbaum-Krumme, Sandra; Bockisch, Andreas; Stahl, Alexander; Mikat, Christian; Heusner, Till Alexander; Antoch, Gerald

2011-01-01

This study compares intrinsically coregistered 124 I positron emission tomography (PET) and CT (PET/CT) and software coregistered 124 I PET and MRI (PET/MRI) images for the diagnosis and dosimetry of thyroid remnant tissues and lymph node metastases in patients with differentiated thyroid carcinoma (DTC). After thyroidectomy, 33 high-risk DTC patients (stage III or higher) received 124 I PET/CT dosimetry prior to radioiodine therapy to estimate the absorbed dose to lesions and subsequently underwent a contrast-enhanced MRI examination of the neck. Images were evaluated by two experienced nuclear medicine physicians and two radiologists to identify the lesions and to categorize their presumable provenience, i.e. thyroid remnant tissue (TT), lymph node metastasis (LN) and inconclusive tissue. The categorization and dosimetry of lesions was initially performed with PET images alone (PET only). Subsequently lesions were reassessed including the CT and MRI data. The analyses were performed on a patient and on a lesion basis. Patient-based analyses showed that 26 of 33 (79%) patients had at least one lesion categorized as TT on PET only. Of these patients, 11 (42%) and 16 (62%) had a morphological correlate on CT and MRI, respectively, in at least one TT PET lesion. Twelve patients (36%) had at least one lesion classified as LN on PET only. Nine (75%) of these patients had a morphological correlate on both CT and MRI in at least one LN PET lesion. Ten patients (30%) showed at least one lesion on PET only classified as inconclusive. The classification was changed to a clear classification in two patients (two LN) by CT and in four (two TT, two LN) patients by MRI. Lesion-based analyses (n = 105 PET positive lesions) resulted in categorization as TT in 61 cases (58%), 16 (26%) of which had a morphological correlate on CT and 33 (54%) on MRI. A total of 29 lesions (27%) were classified as LN on PET, 18 (62%) of which had a morphological correlate on CT and 24 (83%) on MRI

Clinical Application of F-18 FDG PET (PET/CT) in Colo-rectal and Anal Cancer

International Nuclear Information System (INIS)

Kim, Byung Il

2008-01-01

In the management of colo-retal and anal cancer, accurate staging, treatment evaluation, early detection of recurrence are main clinical problems. F-18 FDG PET (PET/CT) has been reported as useful in the management of colo-rectal and anal cancer because that PET has high diagnostic performance comparing to conventional studies. In case of liver metastases, for confirmation of no extrahepatic metastases, in case of high risk of metastasis, for avoiding unnecessary operation, PET (PET/CT) is expected more useful. In anal cancer, PET is expected useful in lymph node staging. For the early prediction of chemotherapy or radiation therapy effect PET has been reported as useful, also. In early detection of recurrence by PET, cost-benefit advantages has been suggested, also. PET/CT is expected to have higher diagnostic performance than PET alone

Clinical Application of F-18 FDG PET (PET/CT) in Malignancy of Unknown Origin

International Nuclear Information System (INIS)

Kim, Byung Il

2008-01-01

Diagnosis of primary origin site in the management of malignancy of unknown origin (MUO) is the most important issue. According to the histopathologic subtype of primary lesion, specialized treatment can be given and survival gain is expected. F-18 FDG PET (PET/CT) has been estimated as useful in detection of primary lesion with high sensitivity and moderate specificity. F-18 FDG PET (PET/CT) study before conventional studies is also recommended because it has high diagnostic performance compared to conventional studies. Although there has few data, F-18 FDG PET (PET/CT) is expected to be useful in diagnosis of recurrence, restaging, evaluation of treatment effect, considering that PET (PET/CT) has been reported as useful in other malignancies

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-09-21

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

Trends in PET imaging

International Nuclear Information System (INIS)

Moses, William W.

2000-01-01

Positron Emission Tomography (PET) imaging is a well established method for obtaining information on the status of certain organs within the human body or in animals. This paper presents an overview of recent trends PET instrumentation. Significant effort is being expended to develop new PET detector modules, especially those capable of measuring depth of interaction. This is aided by recent advances in scintillator and pixellated photodetector technology. The other significant area of effort is development of special purpose PET cameras (such as for imaging breast cancer or small animals) or cameras that have the ability to image in more than one modality (such as PET / SPECT or PET / X-Ray CT)

Imaging with {sup 124}I in differentiated thyroid carcinoma: is PET/MRI superior to PET/CT?

Energy Technology Data Exchange (ETDEWEB)

Binse, I.; Poeppel, T.D.; Ruhlmann, M.; Gomez, B.; Bockisch, A.; Rosenbaum-Krumme, S.J. [University of Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Essen (Germany); Umutlu, L. [University of Duisburg-Essen, Medical Faculty, Department of Radiology, Essen (Germany)

2016-06-15

The aim of this study was to compare integrated PET/CT and PET/MRI for their usefulness in detecting and categorizing cervical iodine-positive lesions in patients with differentiated thyroid cancer using {sup 124}I as tracer. The study group comprised 65 patients at high risk of iodine-positive metastasis who underwent PET/CT (low-dose CT scan, PET acquisition time 2 min; PET/CT{sub 2}) followed by PET/MRI of the neck 24 h after {sup 124}I administration. PET images from both modalities were analysed for the numbers of tracer-positive lesions. Two different acquisition times were used for the comparisons, one matching the PET/CT{sub 2} acquisition time (2 min, PET/MRI{sub 2}) and the other covering the whole MRI scan time (30 min, PET/MRI{sub 30}). Iodine-positive lesions were categorized as metastasis, thyroid remnant or inconclusive according to their location on the PET/CT images. Morphological information provided by MRI was considered for evaluation of lesions on PET/MRI and for volume information. PET/MRI{sub 2} detected significantly more iodine-positive metastases and thyroid remnants than PET/CT{sub 2} (72 vs. 60, p = 0.002, and 100 vs. 80, p = 0.001, respectively), but the numbers of patients with at least one tumour lesion identified were not significantly different (21/65 vs. 17/65 patients). PET/MRI{sub 30} tended to detect more PET-positive metastases than PET/MRI{sub 2} (88 vs. 72), but the difference was not significant (p = 0.07). Of 21 lesions classified as inconclusive on PET/CT, 5 were assigned to metastasis or thyroid remnant when evaluated by PET/MRI. Volume information was available in 34 % of iodine-positive metastases and 2 % of thyroid remnants on PET/MRI. PET/MRI of the neck was found to be superior to PET/CT in detecting iodine-positive lesions. This was attributed to the higher sensitivity of the PET component, Although helpful in some cases, we found no substantial advantage of PET/MRI over PET/CT in categorizing iodine

Imaging corn plants with PhytoPET, a modular PET system for plant biology

Energy Technology Data Exchange (ETDEWEB)

Lee, S.; Kross, B.; McKisson, J.; McKisson, J. E.; Weisenberger, A. G.; Xi, W.; Zorn, C.; Bonito, G.; Howell, C. R.; Reid, C. D.; Crowell, A.; Cumberbatch, L. C.; Topp, C.; Smith, M. F.

2013-11-01

PhytoPET is a modular positron emission tomography (PET) system designed specifically for plant imaging. The PhytoPET design allows flexible arrangements of PET detectors based on individual standalone detector modules built from single Hamamatsu H8500 position sensitive photomultiplier tubes and pixelated LYSO arrays. We have used the PhytoPET system to perform preliminary corn plant imaging studies at the Duke University Biology Department Phytotron. Initial evaluation of the PhytoPET system to image the biodistribution of the positron emitting tracer {sup 11}C in corn plants is presented. {sup 11}CO{sub 2} is loaded into corn seedlings by a leaf-labeling cuvette and translocation of {sup 11}C-sugars is imaged by a flexible arrangement of PhytoPET modules on each side. The PhytoPET system successfully images {sup 11}C within corn plants and allows for the dynamic measurement of {sup 11}C-sugar translocation from the leaf to the roots.

Oncology PET imaging

International Nuclear Information System (INIS)

Inubushi, Masayuki

2014-01-01

At the beginning of this article, likening medical images to 'Where is Waldo?' I indicate the concept of diagnostic process of PET/CT imaging, so that medical physics specialists could understand the role of each imaging modality and infer our distress for image diagnosis. Then, I state the present situation of PET imaging and the basics (e.g. health insurance coverage, clinical significance, principle, protocol, and pitfall) of oncology FDG-PET imaging which accounts for more than 99% of all clinical PET examinations in Japan. Finally, I would like to give a wishful prospect of oncology PET that will expand to be more cancer-specific in order to assess therapeutic effects of emerging molecular targeted drugs targeting the 'hallmarks of cancer'. (author)

Towards time-of-flight PET with a semiconductor detector

Science.gov (United States)

Ariño-Estrada, Gerard; Mitchell, Gregory S.; Kwon, Sun Il; Du, Junwei; Kim, Hadong; Cirignano, Leonard J.; Shah, Kanai S.; Cherry, Simon R.

2018-02-01

The feasibility of using Cerenkov light, generated by energetic electrons following 511 keV photon interactions in the semiconductor TlBr, to obtain fast timing information for positron emission tomography (PET) was evaluated. Due to its high refractive index, TlBr is a relatively good Cerenkov radiator and with its wide bandgap, has good optical transparency across most of the visible spectrum. Coupling an SiPM photodetector to a slab of TlBr (TlBr-SiPM) yielded a coincidence timing resolution of 620 ps FWHM between the TlBr-SiPM detector and a LFS reference detector. This value improved to 430 ps FWHM by applying a high pulse amplitude cut based on the TlBr-SiPM and reference detector signal amplitudes. These results are the best ever achieved with a semiconductor PET detector and already approach the performance required for time-of-flight. As TlBr has higher stopping power and better energy resolution than the conventional scintillation detectors currently used in PET scanners, a hybrid TlBr-SiPM detector with fast timing capability becomes an interesting option for further development.

[18F]FDG PET/CT outperforms [18F]FDG PET/MRI in differentiated thyroid cancer

International Nuclear Information System (INIS)

Vrachimis, Alexis; Wenning, Christian; Weckesser, Matthias; Stegger, Lars; Burg, Matthias Christian; Allkemper, Thomas; Schaefers, Michael

2016-01-01

To evaluate the diagnostic potential of PET/MRI with [ 18 F]FDG in comparison to PET/CT in patients with differentiated thyroid cancer suspected or known to have dedifferentiated. The study included 31 thyroidectomized and remnant-ablated patients who underwent a scheduled [ 18 F]FDG PET/CT scan and were then enrolled for a PET/MRI scan of the neck and thorax. The datasets (PET/CT, PET/MRI) were rated regarding lesion count, conspicuity, diameter and characterization. Standardized uptake values were determined for all [ 18 F]FDG-positive lesions. Histology, cytology, and examinations before and after treatment served as the standards of reference. Of 26 patients with a dedifferentiated tumour burden, 25 were correctly identified by both [ 18 F]FDG PET/CT and PET/MRI. Detection rates by PET/CT and PET/MRI were 97 % (113 of 116 lesions) and 85 % (99 of 113 lesions) for malignant lesions, and 100 % (48 of 48 lesions) and 77 % (37 of 48 lesions) for benign lesions, respectively. Lesion conspicuity was higher on PET/CT for both malignant and benign pulmonary lesions and in the overall rating for malignant lesions (p < 0.001). There was a difference between PET/CT and PET/MRI in overall evaluation of malignant lesions (p < 0.01) and detection of pulmonary metastases (p < 0.001). Surgical evaluation revealed three malignant lesions missed by both modalities. PET/MRI additionally failed to detect 14 pulmonary metastases and 11 benign lesions. In patients with thyroid cancer and suspected or known dedifferentiation, [ 18 F]FDG PET/MRI was inferior to low-dose [ 18 F]FDG PET/CT for the assessment of pulmonary status. However, for the assessment of cervical status, [ 18 F]FDG PET/MRI was equal to contrast-enhanced neck [ 18 F]FDG PET/CT. Therefore, [ 18 F]FDG PET/MRI combined with a low-dose CT scan of the thorax may provide an imaging solution when high-quality imaging is needed and high-energy CT is undesirable or the use of a contrast agent is contraindicated. (orig.)

CyberPET: a PET service distributed over a wide area

International Nuclear Information System (INIS)

Pilloy, W.J.; Hellwig, D.; Schaeffer, A.; Hoffmann, P.; Lens, V.

2002-01-01

Aim: Demonstration of bi-directional PET data transmission, interactive display and co-registration, for the purpose of correlative imaging, treatment planning and teaching. Material and Method: In the year 2000, the initial problem to attend was to provide an effective PET service to a hospital (in Luxemburg) which lies 150 km away from a PET center (in another country). Once this solved, the procedure was expanded (in 2001) to co-registration with CT/MRI scans performed locally, and with radiotherapy simulation CT performed in another center 25 km away (in 2002). Equipment from various vendors was used (Siemens, Adac, GE, Hermes). With preliminary agreement of the national medical aid, patients are sent from the Nuclear Medicine Dept of the Centre Hospitalier in Luxemburg (CHL) to the Dept NM of the Saarland University Medical Center for PET examination. The digital data are then sent from the Siemens PET camera to a PC connected to the LAN, and then to a FTP server (Healthnet). The data are similarly collected by a PC of the hospital network in Luxemburg, and transferred to a Hermes NM station. The Dicom PET data are converted on the fly to Interfile, displayed interactively as any other tomographic data, printed and available on the NM image server. Since 2001, the PET data are co-registered with whole-body CT data recorded at CHL according to a specific protocol (see other paper of this group). Now in 2002, we are busy implementing the co-registration of PET data and simulation CT data obtained from the Centre Baclesse (CFB, 25 km from CHL) for the treatment planning of brain tumours (input into an ADAC system). Furthermore, we plan to send the data (after deletion of their digital ID) to a (South African) university which does not yet dispose of a PET camera, to allow the training of their registrars. Results: For the end-user clinician at CHL and CFB , the PET data have the quality of 'live data', which can be examined interactively, along with other imaging

Optical Imaging of Mammaglobin Expression of Breast Cancer

National Research Council Canada - National Science Library

Achilefu, Samuel I

2003-01-01

.... TO accomplish this goal, we labeled polyclonal and monoclonal anti-MMG antibodies with a near infrared fluorescent probe for optical imaging and 64Cu-DOTA for positron emission tomography (mPET...

Childhood Attachment to Pets: Associations between Pet Attachment, Attitudes to Animals, Compassion, and Humane Behaviour

Directory of Open Access Journals (Sweden)

Roxanne D. Hawkins

2017-05-01

Full Text Available Attachment to pets has an important role in children’s social, emotional, and cognitive development, mental health, well-being, and quality of life. This study examined associations between childhood attachment to pets and caring and friendship behaviour, compassion, and attitudes towards animals. This study also examined socio-demographic differences, particularly pet ownership and pet type. A self-report survey of over one thousand 7 to 12 year-olds in Scotland, UK, revealed that the majority of children are strongly attached to their pets, but attachment scores differ depending on pet type and child gender. Analysis revealed that attachment to pets is facilitated by compassion and caring and pet-directed friendship behaviours and that attachment to pets significantly predicts positive attitudes towards animals. The findings have implications for the promotion of prosocial and humane behaviour. Encouraging children to participate in pet care behaviour may promote attachment between children and their pet, which in turn may have a range of positive outcomes for both children (such as reduced aggression, better well-being, and quality of life and pets (such as humane treatment. This study enhances our understanding of childhood pet attachment and has implications for humane education and promoting secure emotional attachments in childhood.

Improving the utilization of detector motion in PET

International Nuclear Information System (INIS)

Wernick, M.N.; Chintu Chen; Ordonez, C.E.

1992-01-01

The authors first proposed a superresolution concept for PET in their DOE renewal application of last year. Since then, they have implemented the technique in software and have performed several simulation studies that demonstrate the potential value of the proposed method in substantially improving the image quality obtainable by PET. The fundamentals of the approach and initial simulation results were reported in a paper to appear later this year in Journal of the Optical Society of America A. In subsequent publications and presentations they described various extensions of the method and showed that the superresolution method was robust to various misspecifications of the system spatial response functions which are inevitable in a practical implementation. In February of this year, two of them (Wernick and Chen) filed an application with the US Patent Office entitled, Method for Recovering signals in tomographic Measurement Systems, in which they describe various configurations of the superresolution approach as it applies generally to tomographic imaging systems. Various kinds of detector system motions were considered as well as various configurations of the algorithm. the methods described may be useful in a number of situations, but the preferred embodiment detailed in the application refers to the use of signal recovery to exploit the extra information reported by a wobbling PET system

Selecting Safe Pets (For Parents)

Science.gov (United States)

... supplies (pet bowls, pet bed, leash, etc.) as gifts, then selecting the pet as a family. That way, everyone has time to really think about whether your family is ready for a pet. Key Questions Before adopting or purchasing any pet, talk to all family members, discuss ...

Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis

International Nuclear Information System (INIS)

Jin, H.; Yuan, L.; Li, C.; Kan, Y.; Yang, J.; Hao, R.

2014-01-01

The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis.

Science.gov (United States)

Jin, H; Yuan, L; Li, C; Kan, Y; Hao, R; Yang, J

2014-03-01

The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

Clinical Applications of FDG PET and PET/CT in Head and Neck Cancer

Directory of Open Access Journals (Sweden)

Akram Al-Ibraheem

2009-01-01

Full Text Available 18F-FDG PET plays an increasing role in diagnosis and management planning of head and neck cancer. Hybrid PET/CT has promoted the field of molecular imaging in head and neck cancer. This modality is particular relevant in the head and neck region, given the complex anatomy and variable physiologic FDG uptake patterns. The vast majority of 18F-FDG PET and PET/CT applications in head and neck cancer related to head and neck squamous cell carcinoma. Clinical applications of 18F-FDG PET and PET/CT in head and neck cancer include diagnosis of distant metastases, identification of synchronous 2nd primaries, detection of carcinoma of unknown primary and detection of residual or recurrent disease. Emerging applications are precise delineation of the tumor volume for radiation treatment planning, monitoring treatment, and providing prognostic information. The clinical role of 18F-FDG PET/CT in N0 disease is limited which is in line with findings of other imaging modalities. MRI is usually used for T staging with an intense discussion concerning the preferable imaging modality for regional lymph node staging as PET/CT, MRI, and multi-slice spiral CT are all improving rapidly. Is this review, we summarize recent literature on 18F-FDG PET and PET/CT imaging of head and neck cancer.

Feasibility of quantitative PET/CT dosimetry for proton therapy using polymer gels

Energy Technology Data Exchange (ETDEWEB)

Zeidan, O A; Hsi, W C; Lopatiuk-Tirpak, O; Sriprisan, S I; Meeks, S L; Kupelian, P A; Li, Z; Palta, J R, E-mail: lenatirpak@gmail.co

2010-11-01

A feasibility study of proton beam PET/CT off-line quantitative dosimetry using polymer gels is presented. A newly developed proton-sensitive polymer gel dosimeter (BANG( (registered)) 3-Pro2) is used as a dosimeter and a tissue-equivalent phantom medium for this study. We explore a new approach to correlating measured proton 3-dimensional (3D) dose distributions directly to measured positron emission from in the gel medium using PET/CT imaging. A large cylindrical volume (2.2 Litres) of the gel was irradiated with a clinical modulated proton beam using irregular-shaped aperture geometry. The gel was imaged in a nearby PET/CT unit immediately (<3 min) after irradiation. Dose distribution in the gel was generated using an optical tomography scanning system. Direct 3D spatial comparison of dose and positron emission distributions was then performed. Profiles along the beam path show that the distal fall-off of the dose is nearly 2 cm deeper than the activity profile which is comparable to previous studies with plastic phantoms and Monte Carlo simulations of activity distributions. Planar PET and dose distributions at depth and perpendicular to beam axis show a strong one-to-one spatial correlation. This phantom study demonstrates that the gel medium could be potentially useful for quantifying various physical factors that can influence the PET activity range verification method in patients.

Functional neuroanatomy of tics.

Science.gov (United States)

Neuner, Irene; Schneider, Frank; Shah, N Jon

2013-01-01

The therapeutic success of haloperidol in the treatment of Tourette syndrome (TS) put an end to the discussion about a "hysteric" or "neurotic" origin of TS. The cortico-striato-thalamo-cortical circuit has been identified as an underlying neurobiological correlate of TS. In this review we explore the main findings of structural alterations in TS including cortical areas, basal ganglia, hippocampus, amygdala, midbrain, and cerebellum. Based on the structural changes we examine the functional pattern described by the findings of fMRI and (15)O-PET/(18)FDG PET investigations. From the neuroimaging findings a cortical origin of the generation of tics is indicated. Future research on the neuronal footprint of TS should be directed towards addressing the question of which patterns of connectivity distinguish individuals in whom tics disappear during early adulthood from those in whom the tics persist. The understanding of this pathomechanism could provide a key on how to influence dysconnectivity in TS, for example, by more specific pharmaceutical intervention or by individually adopted EEG and/or fMRI neurofeedback. © 2013 Elsevier Inc. All rights reserved.

Imaging with PET system

International Nuclear Information System (INIS)

Das, B.K.; Noreen Norfaraheen Lee Abdullah

2012-01-01

PET deals with biochemistry and metabolic changes that occur at molecular level. Hence, PET differs fundamentally from other imaging modalities. CT imaging is based on tissue density, whereas MRI conveys anatomic information based on proton density and proton relaxation dynamics. CT and MRI are useful in clinical diagnosis only when disease process has caused significant anatomic alterations. However, in most disease conditions chemical changes precede anatomic changes, that can be detected by PET technology. Thus, PET can provide earliest and unique information about ongoing disease process long before anatomic or structural changes take place. There is no other modality available at present that can replace PET technology. Although PET produces cross-sectional images like that obtained in MRI or CT, they represent circulation, function and metabolism, and not anatomic structure. PET is extremely sensitive measuring quantitatively concentration of tracers in nano to pico-molar range. Thus, PET enables merger of biochemistry and biology in medicine giving birth to molecular medicine that focuses on identifying the molecular errors of disease leading to developing molecular corrections including gene therapy. Molecular imaging with PET has been playing a role in examining the biological nature of a disease condition and its characterization to guide selection and evaluation of treatment. (author)

Cost-effectiveness of PET and PET/Computed Tomography

DEFF Research Database (Denmark)

Gerke, Oke; Hermansson, Ronnie; Hess, Søren

2015-01-01

measure by means of incremental cost-effectiveness ratios when considering the replacement of the standard regimen by a new diagnostic procedure. This article discusses economic assessments of PET and PET/computed tomography reported until mid-July 2014. Forty-seven studies on cancer and noncancer...

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-09-15

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

Hybrid FDG-PET/MR compared to FDG-PET/CT in adult lymphoma patients.

Science.gov (United States)

Atkinson, Wendy; Catana, Ciprian; Abramson, Jeremy S; Arabasz, Grae; McDermott, Shanaugh; Catalano, Onofrio; Muse, Victorine; Blake, Michael A; Barnes, Jeffrey; Shelly, Martin; Hochberg, Ephraim; Rosen, Bruce R; Guimaraes, Alexander R

2016-07-01

The goal of this study is to evaluate the diagnostic performance of simultaneous FDG-PET/MR including diffusion compared to FDG-PET/CT in patients with lymphoma. Eighteen patients with a confirmed diagnosis of non-Hodgkin's (NHL) or Hodgkin's lymphoma (HL) underwent an IRB-approved, single-injection/dual-imaging protocol consisting of a clinical FDG-PET/CT and subsequent FDG-PET/MR scan. PET images from both modalities were reconstructed iteratively. Attenuation correction was performed using low-dose CT data for PET/CT and Dixon-MR sequences for PET/MR. Diffusion-weighted imaging was performed. SUVmax was measured and compared between modalities and the apparent diffusion coefficient (ADC) using ROI analysis by an experienced radiologist using OsiriX. Strength of correlation between variables was measured using the Pearson correlation coefficient (r p). Of the 18 patients included in this study, 5 had HL and 13 had NHL. The median age was 51 ± 14.8 years. Sixty-five FDG-avid lesions were identified. All FDG-avid lesions were visible with comparable contrast, and therefore initial and follow-up staging was identical between both examinations. SUVmax from FDG-PET/MR [(mean ± sem) (21.3 ± 2.07)] vs. FDG-PET/CT (mean 23.2 ± 2.8) demonstrated a strongly positive correlation [r s = 0.95 (0.94, 0.99); p < 0.0001]. There was no correlation found between ADCmin and SUVmax from FDG-PET/MR [r = 0.17(-0.07, 0.66); p = 0.09]. FDG-PET/MR offers an equivalent whole-body staging examination as compared with PET/CT with an improved radiation safety profile in lymphoma patients. Correlation of ADC to SUVmax was weak, understating their lack of equivalence, but not undermining their potential synergy and differing importance.

Clinical evaluation of PET image quality as a function of acquisition time in a new TOF-PET/MR compared to TOF-PET/CT - initial results

International Nuclear Information System (INIS)

Zeimpekis, Konstantinos; Huellner, Martin; De Galiza Barbosa, Felipe; Ter Voert, Edwin; Davison, Helen; Delso, Gaspar; Veit-Haibach, Patrick

2015-01-01

The recently available integrated PET/MR imaging can offer significant additional advances in clinical imaging. The purpose of this study was to compare the PET performance between a PET/CT scanner and an integrated TOF-PET/MR scanner concerning image quality parameters and quantification in terms of SUV as a function of acquisition time (a surrogate of dose). Five brain and five whole body patients were included in the study. The PET/CT scan was used as a reference and the PET/MR acquisition time was consecutively adjusted, taking into account the decay between the scans in order to expose both systems to the same amount of emitted signal. The acquisition times were then retrospectively reduced to assess the performance of the PET/MRI for lower count rates. Image quality, image sharpness, artifacts and noise were evaluated. SUV measurements were taken in the liver and in white matter to compare quantification. Quantitative evaluation showed good correlation between PET/CT and PET/MR brain SUVs. Liver correlation was lower, with uptake underestimation in PET/MR, partially justified by bio-redistribution. The clinical evaluation showed that PET/MR offers higher image quality and sharpness with lower levels of noise and artefacts compared to PET/CT with reduced acquisition times for whole body scans, while for brain scans there is no significant difference. The PET-component of the TOF-PET/MR showed higher image quality compared to PET/CT as tested with reduced imaging times. However, these results account mainly for body imaging, while no significant difference were found in brain imaging. This overall higher image quality suggests that the acquisition time or injected activity can be reduced by at least 37% on the PET/MR scanner.

Clinical evaluation of PET image quality as a function of acquisition time in a new TOF-PET/MR compared to TOF-PET/CT - initial results

Energy Technology Data Exchange (ETDEWEB)

Zeimpekis, Konstantinos; Huellner, Martin; De Galiza Barbosa, Felipe; Ter Voert, Edwin; Davison, Helen; Delso, Gaspar; Veit-Haibach, Patrick [Nuclear Medicine, University Hospital Zurich (Switzerland)

2015-05-18

The recently available integrated PET/MR imaging can offer significant additional advances in clinical imaging. The purpose of this study was to compare the PET performance between a PET/CT scanner and an integrated TOF-PET/MR scanner concerning image quality parameters and quantification in terms of SUV as a function of acquisition time (a surrogate of dose). Five brain and five whole body patients were included in the study. The PET/CT scan was used as a reference and the PET/MR acquisition time was consecutively adjusted, taking into account the decay between the scans in order to expose both systems to the same amount of emitted signal. The acquisition times were then retrospectively reduced to assess the performance of the PET/MRI for lower count rates. Image quality, image sharpness, artifacts and noise were evaluated. SUV measurements were taken in the liver and in white matter to compare quantification. Quantitative evaluation showed good correlation between PET/CT and PET/MR brain SUVs. Liver correlation was lower, with uptake underestimation in PET/MR, partially justified by bio-redistribution. The clinical evaluation showed that PET/MR offers higher image quality and sharpness with lower levels of noise and artefacts compared to PET/CT with reduced acquisition times for whole body scans, while for brain scans there is no significant difference. The PET-component of the TOF-PET/MR showed higher image quality compared to PET/CT as tested with reduced imaging times. However, these results account mainly for body imaging, while no significant difference were found in brain imaging. This overall higher image quality suggests that the acquisition time or injected activity can be reduced by at least 37% on the PET/MR scanner.

Medical application of PET technology

International Nuclear Information System (INIS)

Lim, Sang Moo; Choi, C. W.; An, S. H.; Woo, K. S.; Chung, W. S.; Yang, S. D.; Jun, G. S. and others

1999-04-01

We performed following studies using PET technology: 1. Clinical usefulness of [ 18 F]FDG whole body PET in malignant disease 2. Clinical usefulness of quantitative evaluation of F-18-FDG 3. Pilot study of C-11 methionine PET in brain tumor 4. PET study in patients with Parkinson's disease 5. A study on the clinical myocardial PET image. PET gives various metabolic information for the living human body, and is very important, new diagnostic modality. The PET study will give us the information of cancer patients such as early detection of cancer, staging, recurrence detection and characterization of cancer. The quantitative analysis using PET could be applied to evaluate the pathophysiology of various diseases and develop new drugs and develop new radiopharmaceuticals

Medical application of PET technology

Energy Technology Data Exchange (ETDEWEB)

Lim, Sang Moo; Choi, C. W.; An, S. H.; Woo, K. S.; Chung, W. S.; Yang, S. D.; Jun, G. S. and others

1999-04-01

We performed following studies using PET technology: 1. Clinical usefulness of [{sup 18}F]FDG whole body PET in malignant disease 2. Clinical usefulness of quantitative evaluation of F-18-FDG 3. Pilot study of C-11 methionine PET in brain tumor 4. PET study in patients with Parkinson's disease 5. A study on the clinical myocardial PET image. PET gives various metabolic information for the living human body, and is very important, new diagnostic modality. The PET study will give us the information of cancer patients such as early detection of cancer, staging, recurrence detection and characterization of cancer. The quantitative analysis using PET could be applied to evaluate the pathophysiology of various diseases and develop new drugs and develop new radiopharmaceuticals.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-15

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

Competitive advantage of PET/MRI

Energy Technology Data Exchange (ETDEWEB)

Jadvar, Hossein, E-mail: jadvar@usc.edu; Colletti, Patrick M.

2014-01-15

Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved.

Competitive advantage of PET/MRI.

Science.gov (United States)

Jadvar, Hossein; Colletti, Patrick M

2014-01-01

Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Competitive advantage of PET/MRI

International Nuclear Information System (INIS)

Jadvar, Hossein; Colletti, Patrick M.

2014-01-01

Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved

Validating PET segmentation of thoracic lesions-is 4D PET necessary?

DEFF Research Database (Denmark)

Nielsen, M. S.; Carl, J.

2017-01-01

Respiratory-induced motions are prone to degrade the positron emission tomography (PET) signal with the consequent loss of image information and unreliable segmentations. This phantom study aims to assess the discrepancies relative to stationary PET segmentations, of widely used semiautomatic PET...... segmentation methods on heterogeneous target lesions influenced by motion during image acquisition. Three target lesions included dual F-18 Fluoro-deoxy-glucose (FDG) tracer concentrations as high-and low tracer activities relative to the background. Four different tracer concentration arrangements were...... segmented using three SUV threshold methods (Max40%, SUV40% and 2.5SUV) and a gradient based method (GradientSeg). Segmentations in static 3D-PET scans (PETsta) specified the reference conditions for the individual segmentation methods, target lesions and tracer concentrations. The motion included PET...

FDG PET and PET/CT : EANM procedure guidelines for tumour PET imaging: version 1.0

NARCIS (Netherlands)

Boellaard, Ronald; O'Doherty, Mike J.; Weber, Wolfgang A.; Mottaghy, Felix M.; Lonsdale, Markus N.; Stroobants, Sigrid G.; Oyen, Wim J. G.; Kotzerke, Joerg; Hoekstra, Otto S.; Pruim, Jan; Marsden, Paul K.; Tatsch, Klaus; Hoekstra, Corneline J.; Visser, Eric P.; Arends, Bertjan; Verzijlbergen, Fred J.; Zijlstra, Josee M.; Comans, Emile F. I.; Lammertsma, Adriaan A.; Paans, Anne M.; Willemsen, Antoon T.; Beyer, Thomas; Bockisch, Andreas; Schaefer-Prokop, Cornelia; Delbeke, Dominique; Baum, Richard P.; Chiti, Arturo; Krause, Bernd J.

The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed

FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0

NARCIS (Netherlands)

Boellaard, Ronald; O'Doherty, Mike J.; Weber, Wolfgang A.; Mottaghy, Felix M.; Lonsdale, Markus N.; Stroobants, Sigrid G.; Oyen, Wim J. G.; Kotzerke, Joerg; Hoekstra, Otto S.; Pruim, Jan; Marsden, Paul K.; Tatsch, Klaus; Hoekstra, Corneline J.; Visser, Eric P.; Arends, Bertjan; Verzijlbergen, Fred J.; Zijlstra, Josee M.; Comans, Emile F. I.; Lammertsma, Adriaan A.; Paans, Anne M.; Willemsen, Antoon T.; Beyer, Thomas; Bockisch, Andreas; Schaefer-Prokop, Cornelia; Delbeke, Dominique; Baum, Richard P.; Chiti, Arturo; Krause, Bernd J.

2010-01-01

The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed

FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0

NARCIS (Netherlands)

Boellaard, R.; O'Doherty, M.J.; Weber, W.A.; Mottaghy, F.M.; Lonsdale, M.N.; Stroobants, S.G.; Oyen, W.J.G.; Kotzerke, J.; Hoekstra, O.S.; Pruim, J.; Marsden, P.K.; Tatsch, K.; Hoekstra, C.J.; Visser, E.P.; Arends, B.; Verzijlbergen, F.J.; Zijlstra, J.M.; Comans, E.F.I.; Lammertsma, A.A.; Paans, A.M.; Willemsen, A.T.; Beyer, T.; Bockisch, A.; Schaefer-Prokop, C.; Delbeke, D.; Baum, R.P.; Chiti, A.; Krause, B.J.

2010-01-01

The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed

Reproducibility of Quantitative Brain Imaging Using a PET-Only and a Combined PET/MR System

Directory of Open Access Journals (Sweden)

Martin L. Lassen

2017-07-01

Full Text Available The purpose of this study was to test the feasibility of migrating a quantitative brain imaging protocol from a positron emission tomography (PET-only system to an integrated PET/MR system. Potential differences in both absolute radiotracer concentration as well as in the derived kinetic parameters as a function of PET system choice have been investigated. Five healthy volunteers underwent dynamic (R-[11C]verapamil imaging on the same day using a GE-Advance (PET-only and a Siemens Biograph mMR system (PET/MR. PET-emission data were reconstructed using a transmission-based attenuation correction (AC map (PET-only, whereas a standard MR-DIXON as well as a low-dose CT AC map was applied to PET/MR emission data. Kinetic modeling based on arterial blood sampling was performed using a 1-tissue-2-rate constant compartment model, yielding kinetic parameters (K1 and k2 and distribution volume (VT. Differences for parametric values obtained in the PET-only and the PET/MR systems were analyzed using a 2-way Analysis of Variance (ANOVA. Comparison of DIXON-based AC (PET/MR with emission data derived from the PET-only system revealed average inter-system differences of −33 ± 14% (p < 0.05 for the K1 parameter and −19 ± 9% (p < 0.05 for k2. Using a CT-based AC for PET/MR resulted in slightly lower systematic differences of −16 ± 18% for K1 and −9 ± 10% for k2. The average differences in VT were −18 ± 10% (p < 0.05 for DIXON- and −8 ± 13% for CT-based AC. Significant systematic differences were observed for kinetic parameters derived from emission data obtained from PET/MR and PET-only imaging due to different standard AC methods employed. Therefore, a transfer of imaging protocols from PET-only to PET/MR systems is not straightforward without application of proper correction methods.Clinical Trial Registration:www.clinicaltrialsregister.eu, identifier 2013-001724-19

Evaluation of PeneloPET Simulations of Biograph PET/CT Scanners

Science.gov (United States)

Abushab, K. M.; Herraiz, J. L.; Vicente, E.; Cal-González, J.; España, S.; Vaquero, J. J.; Jakoby, B. W.; Udías, J. M.

2016-06-01

Monte Carlo (MC) simulations are widely used in positron emission tomography (PET) for optimizing detector design, acquisition protocols, and evaluating corrections and reconstruction methods. PeneloPET is a MC code based on PENELOPE, for PET simulations which considers detector geometry, acquisition electronics and materials, and source definitions. While PeneloPET has been successfully employed and validated with small animal PET scanners, it required a proper validation with clinical PET scanners including time-of-flight (TOF) information. For this purpose, we chose the family of Biograph PET/CT scanners: the Biograph True-Point (B-TP), Biograph True-Point with TrueV (B-TPTV) and the Biograph mCT. They have similar block detectors and electronics, but a different number of rings and configuration. Some effective parameters of the simulations, such as the dead-time and the size of the reflectors in the detectors, were adjusted to reproduce the sensitivity and noise equivalent count (NEC) rate of the B-TPTV scanner. These parameters were then used to make predictions of experimental results such as sensitivity, NEC rate, spatial resolution, and scatter fraction (SF), from all the Biograph scanners and some variations of them (energy windows and additional rings of detectors). Predictions agree with the measured values for the three scanners, within 7% (sensitivity and NEC rate) and 5% (SF). The resolution obtained for the B-TPTV is slightly better (10%) than the experimental values. In conclusion, we have shown that PeneloPET is suitable for simulating and investigating clinical systems with good accuracy and short computational time, though some effort tuning of a few parameters of the scanners modeled may be needed in case that the full details of the scanners studied are not available.

SU-F-I-57: Evaluate and Optimize PET Acquisition Overlap in 18F-FDG Oncology Wholebody PET/CT: Can We Scan PET Faster?

International Nuclear Information System (INIS)

Zhang, J; Natwa, M; Hall, NC; Knopp, MV; Knopp, MU; Zhang, B; Tung, C

2016-01-01

Purpose: The longer patient has to remain on the table during PET imaging, the higher the likelihood of motion artifacts due to patient discomfort. This study was to investigate and optimize PET acquisition overlap in 18F-FDG oncology wholebody PET/CT to speed up PET acquisition and improve patient comfort. Methods: Wholebody 18F-FDG PET/CT of phantoms, 8 pre-clinical patients (beagles) and 5 clinical oncology patients were performed in 90s/bed on a time-of-flight Gemini TF 64 system. Imaging of phantoms and beagles was acquired with reduced PET overlaps (40%, 33%, 27%, 20%, 13% and no overlap) in addition to the system default (53%). In human studies, 1 or 2 reduced overlaps from the listed options were used to acquire PET/CT sweeps right after the default standard of care imaging. Image quality was blindly reviewed using visual scoring criteria and quantitative SUV assessment. NEMA PET sensitivity was performed under different overlaps. Results: All PET exams demonstrated no significant impact on the visual grades for overlaps >20%. Blinded reviews assigned the best visual scores to PET using overlaps 53%–27%. Reducing overlap to 27% for oncology patients (12-bed) saved an average of ∼40% acquisition time (11min) compared to using the default overlap (18min). No significant SUV variances were found when reducing overlap to half of default for cerebellum, lung, heart, aorta, liver, fat, muscle, bone marrow, thighs and target lesions (p>0.05), except expected variability in urinary system. Conclusion: This study demonstrated by combined phantom, pre-clinical and clinical PET/CT scans that PET acquisition overlap in axial of today’s systems can be reduced and optimized. It showed that a reduction of PET acquisition overlap to 27% (half of system default) can be implemented to reduce table time by ∼40% to improve patient comfort and minimize potential motion artifacts, without prominently degrading image quality or compromising PET quantification.

SU-F-I-57: Evaluate and Optimize PET Acquisition Overlap in 18F-FDG Oncology Wholebody PET/CT: Can We Scan PET Faster?

Energy Technology Data Exchange (ETDEWEB)

Zhang, J; Natwa, M; Hall, NC; Knopp, MV [The Ohio State University, Columbus, OH (United States); Knopp, MU [Pepperdine University, Malibu, CA (United States); Zhang, B; Tung, C [Philips Healthcare, Highland Heights, OH (United States)

2016-06-15

Purpose: The longer patient has to remain on the table during PET imaging, the higher the likelihood of motion artifacts due to patient discomfort. This study was to investigate and optimize PET acquisition overlap in 18F-FDG oncology wholebody PET/CT to speed up PET acquisition and improve patient comfort. Methods: Wholebody 18F-FDG PET/CT of phantoms, 8 pre-clinical patients (beagles) and 5 clinical oncology patients were performed in 90s/bed on a time-of-flight Gemini TF 64 system. Imaging of phantoms and beagles was acquired with reduced PET overlaps (40%, 33%, 27%, 20%, 13% and no overlap) in addition to the system default (53%). In human studies, 1 or 2 reduced overlaps from the listed options were used to acquire PET/CT sweeps right after the default standard of care imaging. Image quality was blindly reviewed using visual scoring criteria and quantitative SUV assessment. NEMA PET sensitivity was performed under different overlaps. Results: All PET exams demonstrated no significant impact on the visual grades for overlaps >20%. Blinded reviews assigned the best visual scores to PET using overlaps 53%–27%. Reducing overlap to 27% for oncology patients (12-bed) saved an average of ∼40% acquisition time (11min) compared to using the default overlap (18min). No significant SUV variances were found when reducing overlap to half of default for cerebellum, lung, heart, aorta, liver, fat, muscle, bone marrow, thighs and target lesions (p>0.05), except expected variability in urinary system. Conclusion: This study demonstrated by combined phantom, pre-clinical and clinical PET/CT scans that PET acquisition overlap in axial of today’s systems can be reduced and optimized. It showed that a reduction of PET acquisition overlap to 27% (half of system default) can be implemented to reduce table time by ∼40% to improve patient comfort and minimize potential motion artifacts, without prominently degrading image quality or compromising PET quantification.

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Comparison of rCBF between patients with medial temporal lobe epilepsy and normal controls using H{sub 2}{sup 15}O PET

Energy Technology Data Exchange (ETDEWEB)

Kang, Eun Joo; Lee, Jae Sung; Nam, Hyun Woo; Lee, Sang Kun; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

2002-06-01

The aim of this study was to identify the brain areas whose regional cerebral blood flow (rCBF) was changed in medial temporal lobe epilepsy (mTLE) using H{sub 2}{sup 15}O-PET. 12 patients with mTLE (6 left, 6 right mTLE) and 6 normal controls were scanned during a fixation baseline period and a sensory-motor condition where subjects pressed a button to an upward arrow. A voxel-based analysis using SPM99 software was performed to compare the patient groups with the normal controls for the rCBF during fixation baseline period and for relative changes of rCBF during the sensory-motor task relative to fixation. Duirng the fixation baseline, a significant reduction of rCBF was found posterior insula bilaterally and right frontopolar regions in right mTLE patients compared to the normal controls. In left mTLE patients, the reduction was found in left frontopolar and temporal regions. During the sensory-motor task, rCBF increase over the fixation period, was reduced in left frontal and superior temporal regions in the right mTLE patients whereas in various areas of right hemisphere in left mTLE patients, relative to normal controls. However, the increased rCBF was also found in the left inferior parietal and anterior thalamic/fornix regions in both right and left mTLE patients compared to normal controls. Epilepsy induced changes were found not only in relative increase/ decrease of rCBF during a simple sensory-motor control condition relative to a fixation rest condition but also in the relative rCBF distribution during the rest period.

[F-18]FDG imaging of head and neck tumors: comparison of hybrid PET, dedicated PET and CT

International Nuclear Information System (INIS)

Dresel, S.; Brinkbaeumer, K.; Schmid, R.; Poepperl, G.; Hahn, K.; Szeimies, U.

2001-01-01

Aim: Aim of the study was to evaluate [F-18]FDG imaging of head and neck tumors using a Hybrid-PET device of the 2nd or 3rd generation. Examinations were compared to dedicated PET and Spiral-CT. Methods: 54 patients suffering from head and neck tumors were examined using dedicated PET and Hybrid-PET after injection of 185-350 MBq [F-18]FDG. Examinations were carried out on the dedicated PET first followed by a scan on the Hybrid-PET. Dedicated PET was acquired in 3D mode, Hybrid-PET was performed in list mode using an axial filter. Reconstruction of data was performed iteratively on both, dedicated PET and Hybrid-PET. All patients received a CT scan in multislice technique. All finding have been verified by the goldstandard histology or in case of negative histology by follow up. Results: Using dedicated PET the primary or recurrent lesion was correctly diagnosed in 47/48 patients, using Hybrid-PET in 46/48 patients and using CT in 25/48 patients. Metastatic disease in cervical lymph nodes was diagnosed in 17/18 patients with dedicated PET, in 16/18 patients with Hybrid-PET and in 15/18 with CT. False positive results with regard to lymph node metastasis were seen with one patient for dedicated PET and Hybrid-PET, respectively, and with 18 patients for CT. In a total of 11 patients unknown metastastic lesions were seen with dedicated PET and with Hybrid-PET elsewhere in the body. Additional malignant disease other than the head and neck tumor was found in 4 patients. Conclusion: Using Hybrid-PET for [F-18]FDG imaging reveals a loss of sensitivity and specificity of about 1-5% as compared to dedicated PET in head and neck tumors. [F-18]FDG PET with both, dedicated PET and Hybrid-PET is superior to CT in the diagnosis of primary or recurrent lesions as well as in the assessment of lymph node involvement. (orig.) [de

The spatial distribution of pet dogs and pet cats on the island of Ireland

Directory of Open Access Journals (Sweden)

More Simon J

2011-06-01

Full Text Available Abstract Background There is considerable international research regarding the link between human demographics and pet ownership. In several international studies, pet ownership was associated with household demographics including: the presence of children in the household, urban/rural location, level of education and age/family structure. What is lacking across all these studies, however, is an understanding of how these pets are spatially distributed throughout the regions under study. This paper describes the spatial distribution of pet dog and pet cat owning households on the island of Ireland. Results In 2006, there were an estimated 640,620 pet dog owning households and 215,542 pet cat owning households in Ireland. These estimates are derived from logistic regression modelling, based on household composition to determine pet dog ownership and the type of house to determine pet cat ownership. Results are presented using chloropleth maps. There is a higher density of pet dog owning households in the east of Ireland and in the cities than the west of Ireland and rural areas. However, in urban districts there are a lower proportion of households owning pet dogs than in rural districts. There are more households with cats in the urban areas, but the proportion of households with cats is greater in rural areas. Conclusions The difference in spatial distribution of dog ownership is a reflection of a generally higher density of households in the east of Ireland and in major cities. The higher proportion of ownership in the west is understandable given the higher proportion of farmers and rural dwellings in this area. Spatial representation allows us to visualise the impact of human household distribution on the density of both pet dogs and pet cats on the island of Ireland. This information can be used when analysing risk of disease spread, for market research and for instigating veterinary care.

FDG PET and PET/CT: EANM procedure guidelines for tumour PET imaging: version 1.0

DEFF Research Database (Denmark)

Boellaard, Ronald; O'Doherty, Mike J; Weber, Wolfgang A

2010-01-01

The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomogr...

PET/MR in oncology

DEFF Research Database (Denmark)

Balyasnikova, Svetlana; Löfgren, Johan; de Nijs, Robin

2012-01-01

of the challenges inherent in this new technology, but focus on potential applications for simultaneous PET/MR in the field of oncology. Methods and tracers for use with the PET technology will be familiar to most readers of this journal; thus this paper aims to provide a short and basic introduction to a number...... be applied together with PET increasing the amount of information about the tissues of interest. The potential clinical benefit of applying PET/MR in staging, radiotherapy planning and treatment evaluation in oncology, as well as the research perspectives for the use of PET/MR in the development of new...

18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters.

Science.gov (United States)

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.

Deep-inspiration breath-hold PET/CT versus free breathing PET/CT and respiratory gating PET for reference. Evaluation in 95 patients with lung cancer

International Nuclear Information System (INIS)

Kawano, Tsuyoshi; Ohtake, Eiji; Inoue, Tomio

2011-01-01

The objective of this study was to define the factors that correlate with differences in maximum standardized uptake value (SUV max ) in deep-inspiration breath-hold (DIBH) and free breathing (FB) positron emission tomography (PET)/CT admixed with respiratory gating (RG) PET for reference. Patients (n=95) with pulmonary lesions were evaluated at one facility over 33 months. After undergoing whole-body PET/CT, a RG PET and FB PET/CT scans were obtained, followed by a DIBH PET/CT scan. All scans were recorded using a list-mode dynamic collection method with respiratory gating. The RG PET was reconstructed using phase gating without attenuation correction; the FB PET was reconstructed from the RG PET sinogram datasets with attenuation correction. Respiratory motion distance, breathing cycle speed, and waveform of RG PET were recorded. The SUV max of FB PET/CT and DIBH PET/CT were recorded: the percent difference in SUV max between the FB and DIBH scans was defined as the %BH-index. The %BH-index was significantly higher for lesions in the lower lung area than in the upper lung area. Respiratory motion distance was significantly higher in the lower lung area than in the upper lung area. A significant relationship was observed between the %BH-index and respiratory motion distance. Waveforms without steady end-expiration tended to show a high %BH-index. Significant inverse relationships were observed between %BH-index and cycle speed, and between respiratory motion distance and cycle speed. Decrease in SUV max of FB PET/CT was due to tumor size, distribution of lower lung, long respiratory movement at slow breathing cycle speeds, and respiratory waveforms without steady end-expiration. (author)

Clinical Evaluation of PET Image Quality as a Function of Acquisition Time in a New TOF-PET/MRI Compared to TOF-PET/CT--Initial Results.

Science.gov (United States)

Zeimpekis, Konstantinos G; Barbosa, Felipe; Hüllner, Martin; ter Voert, Edwin; Davison, Helen; Veit-Haibach, Patrick; Delso, Gaspar

2015-10-01

The purpose of this study was to compare only the performance of the PET component between a TOF-PET/CT (henceforth noted as PET/CT) scanner and an integrated TOF-PET/MRI (henceforth noted as PET/MRI) scanner concerning image quality parameters and quantification in terms of standardized uptake value (SUV) as a function of acquisition time (a surrogate of dose). The CT and MR image quality were not assessed, and that is beyond the scope of this study. Five brain and five whole-body patients were included in the study. The PET/CT scan was used as a reference and the PET/MRI acquisition time was consecutively adjusted, taking into account the decay between the scans in order to expose both systems to the same amount of the emitted signal. The acquisition times were then retrospectively reduced to assess the performance of the PET/MRI for lower count rates. Image quality, image sharpness, artifacts, and noise were evaluated. SUV measurements were taken in the liver and in the white matter to compare quantification. Quantitative evaluation showed strong correlation between PET/CT and PET/MRI brain SUVs. Liver correlation was good, however, with lower uptake estimation in PET/MRI, partially justified by bio-redistribution. The clinical evaluation showed that PET/MRI offers higher image quality and sharpness with lower levels of noise and artifacts compared to PET/CT with reduced acquisition times for whole-body scans while for brain scans there is no significant difference. The TOF-PET/MRI showed higher image quality compared to TOF-PET/CT as tested with reduced imaging times. However, this result accounts mainly for body imaging, while no significant differences were found in brain imaging.

Evacuating People and Their Pets: Older Floridians' Need for and Proximity to Pet-Friendly Shelters.

Science.gov (United States)

Douglas, Rachel; Kocatepe, Ayberk; Barrett, Anne E; Ozguven, Eren Erman; Gumber, Clayton

2017-10-04

Pets influence evacuation decisions, but little is known about pet-friendly emergency shelters' availability or older adults' need for them. Our study addresses this issue, focusing on the most densely populated area of Florida (Miami-Dade)-the state with the oldest population and greatest hurricane susceptibility. We use Geographic Information Systems (GIS)-based methodology to identify the shortest paths to pet-friendly shelters, based on distance and congested and uncongested travel times-taking into account the older population's spatial distribution. Logistic regression models using the 2013 American Housing Survey's Disaster Planning Module examine anticipated shelter use as a function of pet ownership and requiring pet evacuation assistance. Thirty-four percent of older adults in the Miami-Dade area have pets-35% of whom report needing pet evacuation assistance. However, GIS accessibility measures show that travel time factors are likely to impede older adults' use of the area's few pet-friendly shelters. Logistic regression results reveal that pet owners are less likely to report anticipating shelter use; however, the opposite holds for pet owners reporting they would need help evacuating their pets-they anticipate using shelters. High pet shelter need coupled with low availability exacerbates older adults' heightened vulnerability during Florida's hurricane season. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Role of FDG-PET and PET/CT in the diagnosis of prolonged febrile states

International Nuclear Information System (INIS)

Jaruskova, M.; Belohlavek, O.

2006-01-01

The role of FDG-PET and PET/CT in patients whose main symptom is prolonged fever has not yet been defined. We addressed this topic in a retrospective study. A total of 124 patients (referred between May 2001 and December 2004) with fever of unknown origin or prolonged fever due to a suspected infection of a joint or vascular prosthesis were included in the study. The patients underwent either FDG-PET or FDG-PET/CT scanning. Sixty-seven patients had a negative focal FDG-PET finding; in this group the method was regarded as unhelpful in determining a diagnosis, and no further investigation was pursued. We tried to obtain clinical confirmation for all patients with positive PET findings. Fifty-seven (46%) patients had positive FDG-PET findings. In six of them no further clinical information was available. Fifty-one patients with positive PET findings and 118 patients in total were subsequently evaluated. Systemic connective tissue disease was confirmed in 17 patients, lymphoma in three patients, inflammatory bowel disease in two patients, vascular prosthesis infection in seven patients, infection of a hip or knee replacement in seven patients, mycotic aneurysm in two patients, abscess in four patients and AIDS in one patient. In eight (16%) patients the finding was falsely positive. FDG-PET or PET/CT contributed to establishing a final diagnosis in 84% of the 51 patients with positive PET findings and in 36% of all 118 evaluated patients with prolonged fever. (orig.)

Bacteriophages safely reduce Salmonella contamination in pet food and raw pet food ingredients.

Science.gov (United States)

Soffer, Nitzan; Abuladze, Tamar; Woolston, Joelle; Li, Manrong; Hanna, Leigh Farris; Heyse, Serena; Charbonneau, Duane; Sulakvelidze, Alexander

2016-01-01

Contamination of pet food with Salmonella is a serious public health concern, and several disease outbreaks have recently occurred due to human exposure to Salmonella tainted pet food. The problem is especially challenging for raw pet foods (which include raw meats, seafood, fruits, and vegetables). These foods are becoming increasingly popular because of their nutritional qualities, but they are also more difficult to maintain Salmonella -free because they lack heat-treatment. Among various methods examined to improve the safety of pet foods (including raw pet food), one intriguing approach is to use bacteriophages to specifically kill Salmonella serotypes. At least 2 phage preparations (SalmoFresh® and Salmonelex™) targeting Salmonella are already FDA cleared for commercial applications to improve the safety of human foods. However, similar preparations are not yet available for pet food applications. Here, we report the results of evaluating one such preparation (SalmoLyse®) in reducing Salmonella levels in various raw pet food ingredients (chicken, tuna, turkey, cantaloupe, and lettuce). Application of SalmoLyse® in low (ca. 2-4×10 6 PFU/g) and standard (ca. 9×10 6 PFU/g) concentrations significantly ( P contamination in all raw foods examined compared to control treatments. When SalmoLyse®-treated (ca. 2×10 7 PFU/g) dry pet food was fed to cats and dogs, it did not trigger any deleterious side effects in the pets. Our data suggest that the bacteriophage cocktail lytic for Salmonella can significantly and safely reduce Salmonella contamination in various raw pet food ingredients.

The MiniPET: a didactic PET system

International Nuclear Information System (INIS)

Pedro, R; Silva, J; Maio, A; Gurriana, L; Silva, J M; Augusto, J Soares

2013-01-01

The MiniPET project aims to design and build a small PET system. It consists of two 4 × 4 matrices of 16 LYSO scintillator crystals and two PMTs with 16 channels resulting in a low cost system with the essential functionality of a clinical PET instrument. It is designed to illustrate the physics of the PET technique and to provide a didactic platform for the training of students and nuclear imaging professionals as well as for scientific outreach. The PET modules can be configured to test for the coincidence of 511 keV gamma rays. The model has a flexible mechanical setup [1] and can simulate 14 diferent ring geometries, from a configuration with as few as 18 detectors per ring (ring radius φ=51 mm), up to a geometry with 70 detectors per ring (φ=200 mm). A second version of the electronic system [2] allowed measurement and recording of the energy deposited in 4 detector channels by photons from a 137 Cs radioactive source and by photons resulting of the annihilation of positrons from a 22 Na radioactive source. These energy spectra are used for detector performance studies, as well as angular dependency studies. In this paper, the mechanical setup, the front-end high-speed analog electronics, the digital acquisition and control electronics implemented in a FPGA, as well as the data-transfer interface between the FPGA board and a host PC are described. Recent preliminary results obtained with the 4 active channels in the prototype are also presented.

Recommendations for the use of PET and PET-CT for radiotherapy planning in research projects.

Science.gov (United States)

Somer, E J; Pike, L C; Marsden, P K

2012-08-01

With the increasing use of positron emission tomography (PET) for disease staging, follow-up and therapy monitoring in a number of oncological indications there is growing interest in the use of PET and PET-CT for radiation treatment planning. In order to create a strong clinical evidence base for this, it is important to ensure that research data are clinically relevant and of a high quality. Therefore the National Cancer Research Institute PET Research Network make these recommendations to assist investigators in the development of radiotherapy clinical trials involving the use of PET and PET-CT. These recommendations provide an overview of the current literature in this rapidly evolving field, including standards for PET in clinical trials, disease staging, volume delineation, intensity modulated radiotherapy and PET-augmented planning techniques, and are targeted at a general audience. We conclude with specific recommendations for the use of PET in radiotherapy planning in research projects.

Quantitative simultaneous PET-MR imaging

Science.gov (United States)

Ouyang, Jinsong; Petibon, Yoann; Huang, Chuan; Reese, Timothy G.; Kolnick, Aleksandra L.; El Fakhri, Georges

2014-06-01

Whole-body PET is currently limited by the degradation due to patient motion. Respiratory motion degrades imaging studies of the abdomen. Similarly, both respiratory and cardiac motions significantly hamper the assessment of myocardial ischemia and/or metabolism in perfusion and viability cardiac PET studies. Based on simultaneous PET-MR, we have developed robust and accurate MRI methods allowing the tracking and measurement of both respiratory and cardiac motions during abdominal or cardiac studies. Our list-mode iterative PET reconstruction framework incorporates the measured motion fields into PET emission system matrix as well as the time-dependent PET attenuation map and the position dependent point spread function. Our method significantly enhances the PET image quality as compared to conventional methods.

Selected PET radiomic features remain the same.

Science.gov (United States)

Tsujikawa, Tetsuya; Tsuyoshi, Hideaki; Kanno, Masafumi; Yamada, Shizuka; Kobayashi, Masato; Narita, Norihiko; Kimura, Hirohiko; Fujieda, Shigeharu; Yoshida, Yoshio; Okazawa, Hidehiko

2018-04-17

We investigated whether PET radiomic features are affected by differences in the scanner, scan protocol, and lesion location using 18 F-FDG PET/CT and PET/MR scans. SUV, TMR, skewness, kurtosis, entropy, and homogeneity strongly correlated between PET/CT and PET/MR images. SUVs were significantly higher on PET/MR 0-2 min and PET/MR 0-10 min than on PET/CT in gynecological cancer ( p = 0.008 and 0.008, respectively), whereas no significant difference was observed between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images in oral cavity/oropharyngeal cancer. TMRs on PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min increased in this order in gynecological cancer and oral cavity/oropharyngeal cancer. In contrast to conventional and histogram indices, 4 textural features (entropy, homogeneity, SRE, and LRE) were not significantly different between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images. 18 F-FDG PET radiomic features strongly correlated between PET/CT and PET/MR images. Dixon-based attenuation correction on PET/MR images underestimated tumor tracer uptake more significantly in oral cavity/oropharyngeal cancer than in gynecological cancer. 18 F-FDG PET textural features were affected less by differences in the scanner and scan protocol than conventional and histogram features, possibly due to the resampling process using a medium bin width. Eight patients with gynecological cancer and 7 with oral cavity/oropharyngeal cancer underwent a whole-body 18 F-FDG PET/CT scan and regional PET/MR scan in one day. PET/MR scans were performed for 10 minutes in the list mode, and PET/CT and 0-2 min and 0-10 min PET/MR images were reconstructed. The standardized uptake value (SUV), tumor-to-muscle SUV ratio (TMR), skewness, kurtosis, entropy, homogeneity, short-run emphasis (SRE), and long-run emphasis (LRE) were compared between PET/CT, PET/MR 0-2 min , and PET/MR 0-10 min images.

Practical use and implementation of PET in children in a hospital PET centre

DEFF Research Database (Denmark)

Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate

2003-01-01

Children are not just small adults-they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use...... and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments......, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine....

Practical use and implementation of PET in children in a hospital PET centre

International Nuclear Information System (INIS)

Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate; Hoejgaard, Liselotte

2003-01-01

Children are not just small adults - they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine. (orig.)

Practical use and implementation of PET in children in a hospital PET centre

Energy Technology Data Exchange (ETDEWEB)

Borgwardt, Lise; Larsen, Helle Jung; Pedersen, Kate; Hoejgaard, Liselotte [Department of Clinical Physiology, Nuclear Medicine and PET, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen (Denmark)

2003-10-01

Children are not just small adults - they differ in their psychology, normal physiology and pathophysiology, and various aspects should be considered when planning a positron emission tomography (PET) scan in a child. PET in children is a growing area, and this article describes the practical use and implementation of PET in children in a hospital PET centre. It is intended to be of use to nuclear medicine departments implementing or starting to implement PET scans in children. Topics covered are: dealing with children, dosimetry, organisation within the department and relations with other departments, preparation of the child (provision of information to the child and parents and the fasting procedure), the imaging procedure (resting, tracer injection, positioning, sedation and bladder emptying) and pitfalls in the interpretation of PET scans in children, including experiences with telemedicine. (orig.)

Healthy Pets and People

Science.gov (United States)

... prevent the spread of germs between pets and people. Keep pets and their supplies out of the kitchen, and ... a local wildlife rehabilitation facility. More Information Healthy Pets Healthy People Clean Hands Save Lives! Stay Healthy at Animal ...

Clinical Nononcologic Applications of PET/CT and PET/MRI in Musculoskeletal, Orthopedic, and Rheumatologic Imaging.

Science.gov (United States)

Gholamrezanezhad, Ali; Basques, Kyle; Batouli, Ali; Matcuk, George; Alavi, Abass; Jadvar, Hossein

2018-06-01

With improvements in PET/CT and PET/MRI over the last decade, as well as increased understanding of the pathophysiology of musculoskeletal diseases, there is an emerging potential for PET as a primary or complementary modality in the management of rheumatologic and orthopedic conditions. We discuss the role of PET/CT and PET/MRI in nononcologic musculoskeletal disorders, including inflammatory and infectious conditions and postoperative complications. There is great potential for an increased role for PET to serve as a primary or complementary modality in the management of orthopedic and rheumatologic disorders.

Influence of PET/CT-introduction on PET scanning frequency and indications. Results of a multicenter study

International Nuclear Information System (INIS)

Stergar, H.; Bockisch, A.; Eschmann, S.M.; Krause, B.J.; Roedel, R.; Tiling, R.; Weckesser, M.

2007-01-01

Aim: to evaluate the influence of the introduction of combined PET/CT scanners into clinical routine. This investigation addresses the quantitative changes between PET/CT and stand alone PET. Methods: the study included all examinations performed on stand alone PET- or PET/CT-scanners within 12 month prior to and after implementation of PET/CT. The final data analysis included five university hospitals and a total number of 15 497 exams. We distinguished exams on stand alone tomographs prior to and after installation of the combined device as well as PET/CT scans particularly with regard to disease entities. Various further parameters were investigated. Results: the overall number of PET scans (PET and PET/CT) rose by 146% while the number of scans performed on stand alone scanners declined by 22%. Only one site registered an increase in stand alone PET. The number of exams for staging in oncology increased by 196% while that of cardiac scans decreased by 35% and the number of scans in neurology rose by 47%. The use of scans for radiotherapy planning increased to 7% of all PET/CT studies. The increase of procedures for so-called classic PET oncology indications was moderate compared to the more common tumors. An even greater increase was observed in some rare entities. Conclusions: the introduction of PET/CT led to more than a doubling of overall PET procedures with a main focus on oncology. Some of the observed changes in scanning frequency may be caused by a rising availability of new radiotracers and advancements of competing imaging methods. Nevertheless the evident increase in the use of PET/CT for the most common tumour types demonstrates its expanding role in cancer staging. The combination of molecular and morphologic imaging has not only found its place but is still gaining greater importance with new developments in technology and radiochemistry. (orig.)

Breast cancer detection using high-resolution breast PET compared to whole-body PET or PET/CT

Energy Technology Data Exchange (ETDEWEB)

Kalinyak, Judith E. [Naviscan Inc., San Diego, CA (United States); Berg, Wendie A. [University of Pittsburgh School of Medicine, Magee-Womens Hospital, Pittsburgh, PA (United States); Schilling, Kathy [Boca Raton Regional Hospital, Boca Raton, FL (United States); Madsen, Kathleen S. [Certus International, Inc., St. Louis, MO (United States); Narayanan, Deepa [Naviscan Inc., San Diego, CA (United States); National Cancer Institute, Bethesda, MD (United States); Tartar, Marie [Scripps Clinic, Scripps Green Hospital, La Jolla, CA (United States)

2014-02-15

To compare the performance characteristics of positron emission mammography (PEM) with those of whole-body PET (WBPET) and PET/CT in women with newly diagnosed breast cancer. A total of 178 women consented to PEM for presurgical planning in an IRB-approved protocol and also underwent either WBPET (n = 69) or PET/CT (n = 109) imaging, as per usual care at three centers. Tumor detection sensitivity, positive predictive values, and {sup 18}F-fluorodeoxyglucose (FDG) uptake were compared between the modalities. The effects of tumor size, type, and grade on detection were examined. The chi-squared or Fisher's exact tests were used to compare distributions between groups, and McNemar's test was used to compare distributions for paired data within subject groups, i.e. PEM versus WBPET or PEM versus PET/CT. The mean age of the women was 59 ± 12 years (median 60 years, range 26-89 years), with a mean invasive index tumor size of 1.6 ± 0.8 cm (median 1.5 cm, range 0.5-4.0 cm). PEM detected more index tumors (61/66, 92 %) than WBPET (37/66, 56 %; p < 0.001) or PET/CT (95/109, 87 % vs. 104/109, 95 % for PEM; p < 0.029). Sensitivity for the detection of additional ipsilateral malignancies was also greater with PEM (7/15, 47 %) than with WBPET (1/15, 6.7 %; p = 0.014) or PET/CT (3/23, 13 % vs. 13/23, 57 % for PEM; p = 0.003). Index tumor detection decreased with decreasing invasive tumor size for both WBPET (p = 0.002) and PET/CT (p < 0.001); PEM was not significantly affected (p = 0.20). FDG uptake, quantified in terms of maximum PEM uptake value, was lowest in ductal carcinoma in situ (median 1.5, range 0.7-3.0) and invasive lobular carcinoma (median 1.5, range 0.7-3.4), and highest in grade III invasive ductal carcinoma (median 3.1, range 1.4-12.9). PEM was more sensitive than either WBPET or PET/CT in showing index and additional ipsilateral breast tumors and remained highly sensitive for tumors smaller than 1 cm. (orig.)

Direct comparison of [18F]FDG PET/CT with PET alone and with side-by-side PET and CT in patients with malignant melanoma

International Nuclear Information System (INIS)

Mottaghy, Felix M.; Wohlfart, Petra; Blumstein, Norbert M.; Neumaier, Bernd; Glatting, Gerhard; Buck, Andreas K.; Reske, Sven N.; Sunderkoetter, Cord; Schubert, Roland; Oezdemir, Cueneyt; Scharfetter-Kochanek, Karin

2007-01-01

The purpose of this retrospective, blinded study was to evaluate the additional value of [ 18 F]FDG PET/CT in comparison with PET alone and with side-by-side PET and CT in patients with malignant melanoma (MM). A total of 127 consecutive studies of patients with known MM referred for a whole-body PET/CT examination were included in this study. PET alone, side-by-side PET and CT and integrated PET/CT study were independently and separately interpreted without awareness of the clinical information. One score each was applied for certainty of lesion localisation and for certainty of lesion characterisation. Verification of the findings was subsequently performed using all available clinical, pathological (n = 30) and follow-up information. The number of lesions with an uncertain localisation was significantly (p 18 F]FDG. (orig.)

18F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

International Nuclear Information System (INIS)

Mhlanga, Joyce C.; Lodge, Martin; Carrino, John A.; Wang, Hao; Wahl, Richard L.

2014-01-01

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. (orig.)

Implementation and performance of an optical motion tracking system for high resolution brain PET imaging

Science.gov (United States)

Lopresti, B. J.; Russo, A.; Jones, W. F.; Fisher, T.; Crouch, D. G.; Altenburger, D. E.; Townsend, D. W.

1999-12-01

Head motion during PET scanning is widely regarded as a source of image degradation and resolution loss. Recent improvements in the spatial resolution of state-of-the-art tomographs may be compromised by patient motion during scanning, as these high resolution data will be increasingly susceptible to smaller movements of the head. The authors have developed an opto-electronic motion tracking system based on commercially-available technology that is capable of very accurate real-time measurements of the position and orientation of the patient's head. These positions are transformed to the reference frame of the PET scanner, and could potentially be used to provide motion correction of list-mode emission data on an event-by-event basis.

Combined PET/MRI

DEFF Research Database (Denmark)

Bailey, D L; Pichler, B J; Gückel, B

2018-01-01

The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tübingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants c...... of response to pharmacological interventions and therapies. As such, PET/MRI is a key to advancing medicine and patient care.......The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tübingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants...... critically assessed the current state of PET/MRI, both clinically and as a research tool, and attempted to chart future directions. The meeting addressed the use of PET/MRI and workflows in oncology, neurosciences, infection, inflammation and chronic pain syndromes, as well as deeper discussions about how...

Local recurrence of prostate cancer after radical prostatectomy is at risk to be missed in {sup 68}Ga-PSMA-11-PET of PET/CT and PET/MRI: comparison with mpMRI integrated in simultaneous PET/MRI

Energy Technology Data Exchange (ETDEWEB)

Freitag, Martin T. [Department of Radiology, German Cancer Research Center, Heidelberg (Germany); Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany); Radtke, Jan P. [Department of Radiology, German Cancer Research Center, Heidelberg (Germany); University Hospital Heidelberg, Department of Urology, Heidelberg (Germany); Afshar-Oromieh, Ali; Flechsig, Paul; Giesel, Frederik; Haberkorn, Uwe [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); Roethke, Matthias C.; Bonekamp, David; Schlemmer, Heinz-Peter [Department of Radiology, German Cancer Research Center, Heidelberg (Germany); Hadaschik, Boris A.; Hohenfellner, Markus [University Hospital Heidelberg, Department of Urology, Heidelberg (Germany); Gleave, Martin [University of British Columbia, The Vancouver Prostate Centre, Vancouver (Canada); Kopka, Klaus; Eder, Matthias [Division of Radiopharmaceutical Chemistry, German Cancer Research Center, Heidelberg (Germany); Heusser, Thorsten; Kachelriess, Marc [Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany); Wieczorek, Kathrin [University Hospital Heidelberg, Institute of Pathology, Heidelberg (Germany); Sachpekidis, Christos; Dimitrakopoulou-Strauss, A. [Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, Heidelberg (Germany)

2017-05-15

The positron emission tomography (PET) tracer {sup 68}Ga-PSMA-11, targeting the prostate-specific membrane antigen (PSMA), is rapidly excreted into the urinary tract. This leads to significant radioactivity in the bladder, which may limit the PET-detection of local recurrence (LR) of prostate cancer (PC) after radical prostatectomy (RP), developing in close proximity to the bladder. Here, we analyze if there is additional value of multi-parametric magnetic resonance imaging (mpMRI) compared to the {sup 68}Ga-PSMA-11-PET-component of PET/CT or PET/MRI to detect LR. One hundred and nineteen patients with biochemical recurrence after prior RP underwent both hybrid {sup 68}Ga-PSMA-11-PET/CT{sub low-dose} (1 h p.i.) and -PET/MRI (2-3 h p.i.) including a mpMRI protocol of the prostatic bed. The comparison of both methods was restricted to the abdomen with focus on LR (McNemar). Bladder-LR distance and recurrence size were measured in axial T2w-TSE. A logistic regression was performed to determine the influence of these variables on detectability in {sup 68}Ga-PSMA-11-PET. Standardized-uptake-value (SUV{sub mean}) quantification of LR was performed. There were 93/119 patients that had at least one pathologic finding. In addition, 18/119 Patients (15.1%) were diagnosed with a LR in mpMRI of PET/MRI but only nine were PET-positive in PET/CT and PET/MRI. This mismatch was statistically significant (p = 0.004). Detection of LR using the PET-component was significantly influenced by proximity to the bladder (p = 0.028). The PET-pattern of LR-uptake was classified into three types (1): separated from bladder; (2): fuses with bladder, and (3): obliterated by bladder. The size of LRs did not affect PET-detectability (p = 0.84), mean size was 1.7 ± 0.69 cm long axis, 1.2 ± 0.46 cm short-axis. SUV{sub mean} in nine men was 8.7 ± 3.7 (PET/CT) and 7.0 ± 4.2 (PET/MRI) but could not be quantified in the remaining nine cases (obliterated by bladder). The present study demonstrates

'Serial review on clinical PET tracers'. Application of health insurance of [15O]oxygen PET and [18F]FDG-PET

International Nuclear Information System (INIS)

Torizuka, Kanji

2009-01-01

As regards the application required for health insurance of PET, the Ministry of Health, Labour and Welfare indicates the following procedures: first, request a permission to the Ministry of Health, Labour and Welfare for the clinical use of the automatic synthetic instrument for PET drug, approved according to the Pharmaceutical Affairs Law. Second, put into practice the use of PET test, under the highly advanced medicine premises. Then, in case of gathered positive results, the health insurance is approved for this PET test. Thus, following the above mentioned procedures, first, the use of [ 15 O] oxygen PET was approved in April 1996. Second, the use of [ 18 F]FDG-PET was approved in 12 different diseases: epilepsy, ischemic heart disease and 10 different types of cancer, in April 2002. Third, in April 2006, a additional 3 types of cancer were approved. Now, we are in the process to get the health insurance of all kinds of malignant tumors (cancer and sarcoma) except for the early gastric cancer. (author)

PET studies in epilepsy

Science.gov (United States)

Sarikaya, Ismet

2015-01-01

Various PET studies, such as measurements of glucose, serotonin and oxygen metabolism, cerebral blood flow and receptor bindings are availabe for epilepsy. 18Fluoro-2-deoxyglucose (18F-FDG) PET imaging of brain glucose metabolism is a well established and widely available technique. Studies have demonstrated that the sensitivity of interictal FDG-PET is higher than interictal SPECT and similar to ictal SPECT for the lateralization and localization of epileptogenic foci in presurgical patients refractory to medical treatments who have noncontributory EEG and MRI. In addition to localizing epileptogenic focus, FDG-PET provide additional important information on the functional status of the rest of the brain. The main limitation of interictal FDG-PET is that it cannot precisely define the surgical margin as the area of hypometabolism usually extends beyond the epileptogenic zone. Various neurotransmitters (GABA, glutamate, opiates, serotonin, dopamine, acethylcholine, and adenosine) and receptor subtypes are involved in epilepsy. PET receptor imaging studies performed in limited centers help to understand the role of neurotransmitters in epileptogenesis, identify epileptic foci and investigate new treatment approaches. PET receptor imaging studies have demonstrated reduced 11C-flumazenil (GABAA-cBDZ) and 18F-MPPF (5-HT1A serotonin) and increased 11C-cerfentanil (mu opiate) and 11C-MeNTI (delta opiate) bindings in the area of seizure. 11C-flumazenil has been reported to be more sensitive than FDG-PET for identifying epileptic foci. The area of abnormality on GABAAcBDZ and opiate receptor images is usually smaller and more circumscribed than the area of hypometabolism on FDG images. Studies have demonstrated that 11C-alpha-methyl-L-tryptophan PET (to study synthesis of serotonin) can detect the epileptic focus within malformations of cortical development and helps in differentiating epileptogenic from non-epileptogenic tubers in patients with tuberous sclerosis complex

Structural, optical and electrical characteristics of ITO thin films deposited by sputtering on different polyester substrates

International Nuclear Information System (INIS)

Guillen, C.; Herrero, J.

2008-01-01

Indium tin oxide (ITO) thin films were deposited by sputtering at room temperature on glass and different polyester substrates; namely polyarylate (PA), polycarbonate (PC) and polyethylene terephtalate (PET). The influence of the substrate on the structural, optical and electrical characteristics of the ITO layers was investigated. The sputtered films exhibited crystallization in the (2 2 2) orientation, with higher mean crystallite size and lower structural distortion onto PET than onto PA, PC or glass substrates. ITO films deposited onto PET showed also higher band gap energy, higher carrier concentration and lower resistivity than the ITO layers onto the other tested substrates. These optical and electrical characteristics have been related to the structural distortion that was found dependent on the specific polyester substrate

Development of a small prototype for a proof-of-concept of OpenPET imaging

International Nuclear Information System (INIS)

Yamaya, Taiga; Yoshida, Eiji; Wakizaka, Hidekatsu; Kokuryo, Daisuke; Tsuji, Atsushi; Mitsuhashi, Takayuki; Tashima, Hideaki; Nishikido, Fumihiko; Inadama, Naoko; Murayama, Hideo; Kinouchi, Shoko; Inaniwa, Taku; Sato, Shinji; Nakajima, Yasunori; Kawai, Hideyuki; Haneishi, Hideaki; Suga, Mikio

2011-01-01

The OpenPET geometry is our new idea to visualize a physically opened space between two detector rings. In this paper, we developed the first small prototype to show a proof-of-concept of OpenPET imaging. Two detector rings of 110 mm diameter and 42 mm axial length were placed with a gap of 42 mm. The basic imaging performance was confirmed through phantom studies; the open imaging was realized at the cost of slight loss of axial resolution and 24% loss of sensitivity. For a proof-of-concept of PET image-guided radiation therapy, we carried out the in-beam tests with 11 C radioactive beam irradiation in the heavy ion medical accelerator in Chiba to visualize in situ distribution of primary particles stopped in a phantom. We showed that PET images corresponding to dose distribution were obtained. For an initial proof-of-concept of real-time multimodal imaging, we measured a tumor-inoculated mouse with 18 F-FDG, and an optical image of the mouse body surface was taken during the PET measurement by inserting a digital camera in the ring gap. We confirmed that the tumor in the gap was clearly visualized. The result also showed the extension effect of an axial field-of-view (FOV); a large axial FOV of 126 mm was obtained with the detectors that originally covered only an 84 mm axial FOV. In conclusion, our initial imaging studies showed promising performance of the OpenPET.

Development of a small prototype for a proof-of-concept of OpenPET imaging

Energy Technology Data Exchange (ETDEWEB)

Yamaya, Taiga; Yoshida, Eiji; Wakizaka, Hidekatsu; Kokuryo, Daisuke; Tsuji, Atsushi; Mitsuhashi, Takayuki; Tashima, Hideaki; Nishikido, Fumihiko; Inadama, Naoko; Murayama, Hideo; Kinouchi, Shoko [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Inaniwa, Taku; Sato, Shinji [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Nakajima, Yasunori [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); Kawai, Hideyuki; Haneishi, Hideaki; Suga, Mikio, E-mail: taiga@nirs.go.jp [Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522 (Japan)

2011-02-21

The OpenPET geometry is our new idea to visualize a physically opened space between two detector rings. In this paper, we developed the first small prototype to show a proof-of-concept of OpenPET imaging. Two detector rings of 110 mm diameter and 42 mm axial length were placed with a gap of 42 mm. The basic imaging performance was confirmed through phantom studies; the open imaging was realized at the cost of slight loss of axial resolution and 24% loss of sensitivity. For a proof-of-concept of PET image-guided radiation therapy, we carried out the in-beam tests with {sup 11}C radioactive beam irradiation in the heavy ion medical accelerator in Chiba to visualize in situ distribution of primary particles stopped in a phantom. We showed that PET images corresponding to dose distribution were obtained. For an initial proof-of-concept of real-time multimodal imaging, we measured a tumor-inoculated mouse with {sup 18}F-FDG, and an optical image of the mouse body surface was taken during the PET measurement by inserting a digital camera in the ring gap. We confirmed that the tumor in the gap was clearly visualized. The result also showed the extension effect of an axial field-of-view (FOV); a large axial FOV of 126 mm was obtained with the detectors that originally covered only an 84 mm axial FOV. In conclusion, our initial imaging studies showed promising performance of the OpenPET.

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-03-21

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

FDG-PET and FDG-PET/CT for therapy monitoring and restaging in malignant lymphoma

International Nuclear Information System (INIS)

Mottaghy, F.M.; Krause, B.J.

2003-01-01

F-18-fluorodeoxyglucose (FDG) PET allows to assess residual masses in patients with malignant lymphoma differentiating vital tumor from scar tissue. This approach is not applicable with conventional imaging methods (CDM) such as CT or MRI. On the other hand circumscribed results often cannot be definitely allocated in PET, therefore the combined morphological-biochemical approach using the now available PET/CT systems promises to be a pathbreaking technical progress. There is no doubt that stand alone PET is superior to CDM differentiating residual scar tissue from vital tumor as has been shown in 15 recently published studies. The median sensitivity for detecting active disease with FDG PET across the studies was 91%; the corresponding specificity was 89%. As a result FDG PET had a high negative predictive value of 94%. In contrast, specificity and positive predictive value (PPV) of CDM in the 9 studies were a direct comparison was available were low (31% and 46%, one study 82%). PET positive residual masses were associated with a progression-free survival of 0 - 55%. Only a few studies have included FDG-PET in therapy response monitoring studies, however also these results are promising. At the moment FDG-PET seems to be the best possibility to characterize and qualitatively visualize vitality of tumor masses and also hold promises for efficient therapy response monitoring in patients with malignant lymphoma. Therefore it should be included in standard diagnostic protocols in lymphoma patients. The combined PET/CT has to be ranked superior to conventional PET studies as in many cases the combined structural and functional imaging brings a clearer diagnostic statement. (orig.) [de

Comparison of the diagnosis using FDG-PET and AC-PET with histopathological features in lung adenocarcinomas

International Nuclear Information System (INIS)

Koizumi, Satoko

2011-01-01

Fluorodeoxyglucose-positron emission tomography (FDG-PET) is a useful tool for lung cancer diagnosis because of its good sensitivity and specificity. However, FDG-PET is problematically causing the false negative in cases of well differentiated lung adenocarcinomas which are low grade malignancies. Acetate (AC)-PET using 11 C-acetate is thought to be a superior detection tool for low grade malignancies. In this study, comparison of each type of PET in relation with histopathological features of lung adenocarcinomas was conducted. Samples obtained from 81 lesions in 75 patients with a lung adenocarcinoma who were operated at various institutions of our collaborators between 2005 and 2009 following FDG-PET and AC-PET procedures were examined. These samples consisted of fifty-seven cases of a well differentiated adenocarcinoma and twenty-four cases of a moderately- or a poorly-differentiated adenocarcinoma. Relationships between the histopathological factors (ly, v, p) as well as the lymphatic microvessel and microvessel densities in a tumor and FDG- and AC-PET findings were evaluated. AC-PET was more sensitive than FDG-PET (0.58 vs 0.74, p=0.0001). FDG-PET showed a correlation with invasiveness of the tumor and intratumoral lymphatic microvessel density (p<0.05). Furthermore, AC-PET possessed a superior sensitivity for the detection of well differentiated adenocarcinomas, and tumors without ly, v, or p factors. In lung adenocarcinoma AC-PET showed better sensitivity than FDG-PET and true positive in all cases of stage I B or more. FDG-PET showed the correlation with the pathological invasiveness (ly, v, p) of a tumor and the intratumoral lymphatic microvessel density. (author)

F-FDG PET/CT (PET/CT) influences management in patients with known or suspected pancreatic cancer

International Nuclear Information System (INIS)

Barber, Thomas W.; Kalff, Victor; Cherk, Martin H.; Yap, Kenneth SK.; Evans, Peter; Kelly, Michael J.

2009-01-01

Full text: Objective: To assess the impact on clinical management of PET/CT in patients with known or suspected pancreatic cancer. Methods: Between April 2006 and September 2008,25 PET/CT scans were performed using a dedicated PET/CT (22 scans) or a coincidence hybrid PET/CT camera (3 scans) in 23 patients with known or suspected pancreatic cancer. 17 scans were performed for initial evaluation and 8 for restaging of disease. The pre-PET/CT management plan and for intent were prospectively recorded in all cases. The post-PET/CT management plan was determined from the medical record and for discussions with treating clinicians. The impact of PET/CT on management was classified as High, Medium, Low or None, defined using ANZAPNM PET data collection project criteria. Follow-up was used to reconcile any discordance between PET/CT and conventional imaging. Results: Overall, PET/CT management impact was classified as high (n equal 7), medium (n equal 4), low (n equal 10) or none (n equal 4). Impact was either high or medium in l l/25 patients (44%) (95% confidence interval; 24 - 64%). Impact was high in 4/17 patients imaged for initial evaluation, predominantly by clarifying equivocal lesions on conventional imaging. In restaged patients, PET/CT impact was high in 3/8, and it correctly modified disease extent in 5/8. In the 16 discordant studies, PET/CT assessment was correct in 10, conventional imaging in 4 and there was insufficient information in 2. Conclusion: PET/CT has high or medium management impact in 44% of patients imaged for known or suspected pancreatic cancer, more commonly during restaging. Discordant PET/CT results were usually correct.

Heart PET scan

Science.gov (United States)

... nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), ...

PET-Tool: a software suite for comprehensive processing and managing of Paired-End diTag (PET sequence data

Directory of Open Access Journals (Sweden)

Wei Chia-Lin

2006-08-01

Full Text Available Abstract Background We recently developed the Paired End diTag (PET strategy for efficient characterization of mammalian transcriptomes and genomes. The paired end nature of short PET sequences derived from long DNA fragments raised a new set of bioinformatics challenges, including how to extract PETs from raw sequence reads, and correctly yet efficiently map PETs to reference genome sequences. To accommodate and streamline data analysis of the large volume PET sequences generated from each PET experiment, an automated PET data process pipeline is desirable. Results We designed an integrated computation program package, PET-Tool, to automatically process PET sequences and map them to the genome sequences. The Tool was implemented as a web-based application composed of four modules: the Extractor module for PET extraction; the Examiner module for analytic evaluation of PET sequence quality; the Mapper module for locating PET sequences in the genome sequences; and the ProjectManager module for data organization. The performance of PET-Tool was evaluated through the analyses of 2.7 million PET sequences. It was demonstrated that PET-Tool is accurate and efficient in extracting PET sequences and removing artifacts from large volume dataset. Using optimized mapping criteria, over 70% of quality PET sequences were mapped specifically to the genome sequences. With a 2.4 GHz LINUX machine, it takes approximately six hours to process one million PETs from extraction to mapping. Conclusion The speed, accuracy, and comprehensiveness have proved that PET-Tool is an important and useful component in PET experiments, and can be extended to accommodate other related analyses of paired-end sequences. The Tool also provides user-friendly functions for data quality check and system for multi-layer data management.

Simultaneous PET-MR acquisition and MR-derived motion fields for correction of non-rigid motion in PET

International Nuclear Information System (INIS)

Tsoumpas, C.; Mackewn, J.E.; Halsted, P.; King, A.P.; Buerger, C.; Totman, J.J.; Schaeffter, T.; Marsden, P.K.

2010-01-01

Positron emission tomography (PET) provides an accurate measurement of radiotracer concentration in vivo, but performance can be limited by subject motion which degrades spatial resolution and quantitative accuracy. This effect may become a limiting factor for PET studies in the body as PET scanner technology improves. In this work, we propose a new approach to address this problem by employing motion information from images measured simultaneously using a magnetic resonance (MR) scanner. The approach is demonstrated using an MR-compatible PET scanner and PET-MR acquisition with a purpose-designed phantom capable of non-rigid deformations. Measured, simultaneously acquired MR data were used to correct for motion in PET, and results were compared with those obtained using motion information from PET images alone. Motion artefacts were significantly reduced and the PET image quality and quantification was significantly improved by the use of MR motion fields, whilst the use of PET-only motion information was less successful. Combined PET-MR acquisitions potentially allow PET motion compensation in whole-body acquisitions without prolonging PET acquisition time or increasing radiation dose. This, to the best of our knowledge, is the first study to demonstrate that simultaneously acquired MR data can be used to estimate and correct for the effects of non-rigid motion in PET. (author)

Feasibility of simultaneous PET/MR of the carotid artery: first clinical experience and comparison to PET/CT

DEFF Research Database (Denmark)

Ripa, Rasmus Sejersten; Knudsen, Andreas; Hag, Anne Mette Fisker

2013-01-01

The study aimed at comparing PET/MR to PET/CT for imaging the carotid arteries in patients with known increased risk of atherosclerosis. Six HIV-positive men underwent sequential PET/MR and PET/CT of the carotid arteries after injection of 400 MBq of 18F-FDG. PET/MR was performed a median of 131......) indicating that the luminal 18F-FDG content had minimal influence on the values. The study shows for the first time that simultaneous PET/MR of the carotid arteries is feasible in patients with increased risk of atherosclerosis. Quantification of 18F-FDG uptake correlated well between PET/MR and PET...

A phoswich detector design for improved spatial sampling in PET

Science.gov (United States)

Thiessen, Jonathan D.; Koschan, Merry A.; Melcher, Charles L.; Meng, Fang; Schellenberg, Graham; Goertzen, Andrew L.

2018-02-01

Block detector designs, utilizing a pixelated scintillator array coupled to a photosensor array in a light-sharing design, are commonly used for positron emission tomography (PET) imaging applications. In practice, the spatial sampling of these designs is limited by the crystal pitch, which must be large enough for individual crystals to be resolved in the detector flood image. Replacing the conventional 2D scintillator array with an array of phoswich elements, each consisting of an optically coupled side-by-side scintillator pair, may improve spatial sampling in one direction of the array without requiring resolving smaller crystal elements. To test the feasibility of this design, a 4 × 4 phoswich array was constructed, with each phoswich element consisting of two optically coupled, 3 . 17 × 1 . 58 × 10mm3 LSO crystals co-doped with cerium and calcium. The amount of calcium doping was varied to create a 'fast' LSO crystal with decay time of 32.9 ns and a 'slow' LSO crystal with decay time of 41.2 ns. Using a Hamamatsu R8900U-00-C12 position-sensitive photomultiplier tube (PS-PMT) and a CAEN V1720 250 MS/s waveform digitizer, we were able to show effective discrimination of the fast and slow LSO crystals in the phoswich array. Although a side-by-side phoswich array is feasible, reflections at the crystal boundary due to a mismatch between the refractive index of the optical adhesive (n = 1 . 5) and LSO (n = 1 . 82) caused it to behave optically as an 8 × 4 array rather than a 4 × 4 array. Direct coupling of each phoswich element to individual photodetector elements may be necessary with the current phoswich array design. Alternatively, in order to implement this phoswich design with a conventional light sharing PET block detector, a high refractive index optical adhesive is necessary to closely match the refractive index of LSO.

{sup 18}F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

Energy Technology Data Exchange (ETDEWEB)

Mhlanga, Joyce C.; Lodge, Martin [Johns Hopkins University School of Medicine, Division of Nuclear Medicine, The Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Carrino, John A. [Johns Hopkins University School of Medicine, Division of Musculoskeletal Radiology, The Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Wang, Hao [Johns Hopkins University School of Medicine, Department of Oncology Biostatistics Division, Baltimore, MD (United States); Wahl, Richard L. [Johns Hopkins University School of Medicine, Division of Nuclear Medicine, The Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Johns Hopkins University Hospitals, Division of Nuclear Medicine, Baltimore, MD (United States)

2014-12-15

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 {sup 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 {sup 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. (orig.)

18F-fluorodeoxyglucose PET and PET-CT in early detection of cancer recurrent

International Nuclear Information System (INIS)

Xing Yan; Zhao Jinhua

2007-01-01

Early detection of recurrent can improve prognosis and survival of patients with cancer. 18 F- fluorodeoxyglucose( 18 F-FDG) PET can detect metabolic changes before structural changes. The fused imaging provided by PET-CT can precisely localize the foci and demonstrate the complementary roles of functional and anatomic assessments in the diagnosis of cancer recurrence. In addition to the accurate diagnosis and definition of the whole extent of recurrent cancer, 18 F-FDG PET and PET-CT can impact patients management. (authors)

PET/MRI. Challenges, solutions and perspectives

Energy Technology Data Exchange (ETDEWEB)

Herzog, Hans [Forschungszentrum Juelich (Germany). Inst. of Neuroscience and Medicine - 4

2012-07-01

Already from the start of PET/CT integrating positron emission tomography (PET) and computed tomography (CT) in one instrument, there have been considerations how to combine PET and magnetic resonance imaging (MRI) so that their complementary abilities can be utilized in a single investigation. Since classical PET electronics fail in an even weak magnetic field and PET signal processing might disturb high-frequency signals of MRI, it soon became clear that new solutions had to be found to avoid mutual interferences. During the last fifteen years a number of different approaches towards PET/MRI for small animal imaging have been developed by research groups which together with their specific features are summarized in this review. Recently, PET/MRI for human imaging became available as well - this time by industrial initiatives. First some prototypes of BrainPET/MRI were developed followed by commercial products for simultaneous and non-simultaneous whole-body PET/MRI. Although only PET/MRI integrated in one scanner offers the full diversity of complementary multiparametric imaging, there are also promising applications of non-simultaneous sequential PET/MRI. While describing the present instrumentation for human PET/MRI, this review discusses the challenges and promises related to this new imaging technology. (orig.)

Adenocarcinoma Prostate With Neuroendocrine Differentiation: Potential Utility of 18F-FDG PET/CT and 68Ga-DOTANOC PET/CT Over 68Ga-PSMA PET/CT.

Science.gov (United States)

Parida, Girish Kumar; Tripathy, Sarthak; Datta Gupta, Shreya; Singhal, Abhinav; Kumar, Rakesh; Bal, Chandrasekhar; Shamim, Shamim Ahmed

2018-04-01

Ga-PSMA PET/CT is the upcoming imaging modality for staging, restaging and response assessment of prostate cancer. However, due to neuroendocrine differentiation in some of patients with prostate cancer, they express somatostatin receptors instead of prostate specific membrane antigen. This can be exploited and other modalities like Ga-DOTANOC PET/CT and F-FDG PET/CT should be used in such cases for guiding management. We hereby discuss a similar case of 67-year-old man of adenocarcinoma prostate with neuroendocrine differentiation, which shows the potential pitfall of Ga-PSMA PET/CT imaging and benefit of Ga-DOTANOC PET/CT and F-FDG PET/CT in such cases.

Molecular Imaging in Breast Cancer: From Whole-Body PET/CT to Dedicated Breast PET

Directory of Open Access Journals (Sweden)

B. B. Koolen

2012-01-01

Full Text Available Positron emission tomography (PET, with or without integrated computed tomography (CT, using 18F-fluorodeoxyglucose (FDG is based on the principle of elevated glucose metabolism in malignant tumors, and its use in breast cancer patients is frequently being investigated. It has been shown useful for classification, staging, and response monitoring, both in primary and recurrent disease. However, because of the partial volume effect and limited resolution of most whole-body PET scanners, sensitivity for the visualization of small tumors is generally low. To improve the detection and quantification of primary breast tumors with FDG PET, several dedicated breast PET devices have been developed. In this nonsystematic review, we shortly summarize the value of whole-body PET/CT in breast cancer and provide an overview of currently available dedicated breast PETs.

Virtual 3-D 18F-FDG PET/CT panendoscopy for assessment of the upper airways of head and neck cancer patients: a feasibility study

International Nuclear Information System (INIS)

Buchbender, Christian; Heusner, Till A.; Treffert, Jon; Lehnerdt, Goetz; Mattheis, Stefan; Geiger, Bernhard; Bockisch, Andreas; Forsting, Michael; Antoch, Gerald

2012-01-01

The aim of this study was to evaluate whether a virtual 3-D 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT panendoscopy is feasible and can be used for noninvasive imaging of the upper airways and pharyngeal/laryngeal tumours. From 18 F-FDG PET/CT data sets of 40 patients (29 men, 11 women; age 61 ± 9 years) with pharyngeal or laryngeal malignancies virtual 3-D 18 F-FDG PET/CT panendoscopies were reconstructed and the image processing time was measured. The feasibility of assessing the oral cavity, nasopharynx, tongue base, soft palate, pharyngeal tonsils, epiglottis, aryepiglottic folds, piriform sinus, postcricoid space, glottis, subglottis, trachea, bronchi and oesophagus and of detecting primary tumours was tested. Results of fibre-optic bronchoscopy and histology served as the reference standard. The nasopharynx, tongue base, soft palate, pharyngeal tonsils, epiglottis, subglottis and the tracheobronchial tree were accessible in all 40, and the aryepiglottic folds, posterior hypopharyngeal wall, postcricoid space, piriform sinus, glottis, oral cavity and oesophagus in 37, 37, 37, 37, 33, 16 and 0 patients, respectively. In all 12 patients with restricted fibre-optic evaluation due to being primarily intubated, the subglottis was accessible via virtual panendoscopy. The primary tumour was depicted in 36 of 40 patients (90 %). The mean processing time for virtual 18 F-FDG PET/CT panendoscopies was 145 ± 98 s. Virtual 18 F-FDG PET/CT panendoscopy of the upper airways is technically feasible and can detect pharyngeal and laryngeal malignancies. This new tool can aid in the complete evaluation of the subglottic space in intubated patients and may be used for planning optical panendoscopies, biopsies and surgery in the future. (orig.)

Cancer screening with FDG-PET

International Nuclear Information System (INIS)

Ide, M.

2006-01-01

Aim: This study is based on medical health check-up and cancer screening on of a medical health club using PET, MRI, spiral CT and other conventional examinations. Methods: Between October 1994 and June 2005, 9357 asymptomatic members of the health club participated in 24772 screening session (5693 men and 3664 women, mean age 52.2±10.4 years). Results: Malignant tumors were discovered in 296 of the 9357 participants (3.16%) and 24772 screening sessions (1.19%). The detection rate of our program is much higher than that of mass screening in Japan. The thyroid, lung, colon and breast cancers were PET positive, but the prostate, renal and bladder cancers were generally PET negative. Conclusion: FDG-PET has the potential to detect a wide variety of cancers at curable stages in asymptomatic individuals. To reduce false-positive and false-negative results of PET examination, there is a need of experienced radiologist and/or oncologists who had training in the wide aspect of FDG-PET. FDG-PET has limitations in the detection of urological cancers, cancers of low cell density, small cancers and hypo metabolic or FDG non-avid cancers. Therefore, conventional examinations and/or PET/CT are also needed for cancer screening in association with FDG-PET

[{sup 18}F]FDG PET/CT outperforms [{sup 18}F]FDG PET/MRI in differentiated thyroid cancer

Energy Technology Data Exchange (ETDEWEB)

Vrachimis, Alexis; Wenning, Christian; Weckesser, Matthias; Stegger, Lars [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Burg, Matthias Christian; Allkemper, Thomas [University Hospital Muenster, Department of Clinical Radiology, Muenster (Germany); Schaefers, Michael [University Hospital Muenster, Department of Nuclear Medicine, Muenster (Germany); Westfaelische Wilhelms University Muenster, European Institute for Molecular Imaging, Muenster (Germany)

2016-02-15

To evaluate the diagnostic potential of PET/MRI with [{sup 18}F]FDG in comparison to PET/CT in patients with differentiated thyroid cancer suspected or known to have dedifferentiated. The study included 31 thyroidectomized and remnant-ablated patients who underwent a scheduled [{sup 18}F]FDG PET/CT scan and were then enrolled for a PET/MRI scan of the neck and thorax. The datasets (PET/CT, PET/MRI) were rated regarding lesion count, conspicuity, diameter and characterization. Standardized uptake values were determined for all [{sup 18}F]FDG-positive lesions. Histology, cytology, and examinations before and after treatment served as the standards of reference. Of 26 patients with a dedifferentiated tumour burden, 25 were correctly identified by both [{sup 18}F]FDG PET/CT and PET/MRI. Detection rates by PET/CT and PET/MRI were 97 % (113 of 116 lesions) and 85 % (99 of 113 lesions) for malignant lesions, and 100 % (48 of 48 lesions) and 77 % (37 of 48 lesions) for benign lesions, respectively. Lesion conspicuity was higher on PET/CT for both malignant and benign pulmonary lesions and in the overall rating for malignant lesions (p < 0.001). There was a difference between PET/CT and PET/MRI in overall evaluation of malignant lesions (p < 0.01) and detection of pulmonary metastases (p < 0.001). Surgical evaluation revealed three malignant lesions missed by both modalities. PET/MRI additionally failed to detect 14 pulmonary metastases and 11 benign lesions. In patients with thyroid cancer and suspected or known dedifferentiation, [{sup 18}F]FDG PET/MRI was inferior to low-dose [{sup 18}F]FDG PET/CT for the assessment of pulmonary status. However, for the assessment of cervical status, [{sup 18}F]FDG PET/MRI was equal to contrast-enhanced neck [{sup 18}F]FDG PET/CT. Therefore, [{sup 18}F]FDG PET/MRI combined with a low-dose CT scan of the thorax may provide an imaging solution when high-quality imaging is needed and high-energy CT is undesirable or the use of a contrast

Modern imaging methods: positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) combination

International Nuclear Information System (INIS)

Votrubova, J.; Belohlavek, O.

2004-01-01

An overview of the title topic is presented. Attention is paid to the technical principles of PET and CT, indications for PET and PET/CT examination, and achievements of the PET Centre of the Na Homolce hospital. (P.A.)

PET/CT and radiotherapy

International Nuclear Information System (INIS)

Messa, C.; CNR, Milano; S. Gerardo Hospital, Monza; Di Muzio, N.; Picchio, M.; Bettinardi, V.; Gilardi, M.C.; CNR, Milano; San Raffaele Scientific Institute, Milano; Fazio, F.; CNR, Milano; San Raffaele Scientific Institute, Milano; San Raffaele Scientific Institute, Milano

2006-01-01

This article reviews the state of the art of PET/CT applications in radiotherapy, specifically its use in disease staging, patient selection, treatment planning and treatment evaluation. Diseases for which radiotherapy with radical intent is indicated will be considered, as well as those in which PET/CT may actually change the course of disease. The methodological and technological aspects of PET/CT in radiotherapy are discussed, focusing on the problem of target volume definition with CT and PET functional imaging and the problem of tumor motion with respect to imaging and dose delivery

Pets and the immunocompromised person

Science.gov (United States)

... marrow transplant patients and pets; Chemotherapy patients and pets ... Centers for Disease Control and Prevention website. Healthy pets healthy people. www.cdc.gov/healthypets . Updated July 19, 2016. ...

Reliability of semiquantitative 18F-FDG PET parameters derived from simultaneous brain PET/MRI: A feasibility study

International Nuclear Information System (INIS)

Jena, Amarnath; Taneja, Sangeeta; Goel, Reema; Renjen, Pushpendranath; Negi, Pradeep

2014-01-01

Purpose: Simultaneous brain PET/MRI faces an important issue of validation of accurate MRI based attenuation correction (AC) method for precise quantitation of brain PET data unlike in PET/CT systems where the use of standard, validated CT based AC is routinely available. The aim of this study was to investigate the feasibility of evaluation of semiquantitative 18 F-FDG PET parameters derived from simultaneous brain PET/MRI using ultrashort echo time (UTE) sequences for AC and to assess their agreement with those obtained from PET/CT examination. Methods: Sixteen patients (age range 18–73 years; mean age 49.43 (19.3) years; 13 men 3 women) underwent simultaneous brain PET/MRI followed immediately by PET/CT. Quantitative analysis of brain PET images obtained from both studies was undertaken using Scenium v.1 brain analysis software package. Twenty ROIs for various brain regions were system generated and 6 semiquantitative parameters including maximum standardized uptake value (SUV max), SUV mean, minimum SUV (SUV min), minimum standard deviation (SD min), maximum SD (SD max) and SD from mean were calculated for both sets of PET data for each patient. Intra-class correlation coefficients (ICCs) were determined to assess agreement between the various semiquantitative parameters for the two PET data sets. Results: Intra-class co-relation between the two PET data sets for SUV max, SUV mean and SD max was highly significant (p < 0.00) for all the 20 predefined brain regions with ICC > 0.9. SD from mean was also found to be statistically significant for all the predefined brain regions with ICC > 0.8. However, SUV max and SUV mean values obtained from PET/MRI were significantly lower compared to those of PET/CT for all the predefined brain regions. Conclusion: PET quantitation accuracy using the MRI based UTE sequences for AC in simultaneous brain PET/MRI is reliable in a clinical setting, being similar to that obtained using PET/CT

An update on the role of PET/CT and PET/MRI in ovarian cancer

International Nuclear Information System (INIS)

Khiewvan, Benjapa; Torigian, Drew A.; Emamzadehfard, Sahra; Paydary, Koosha; Salavati, Ali; Houshmand, Sina; Werner, Thomas J.; Alavi, Abass

2017-01-01

This review article summarizes the role of PET/CT and PET/MRI in ovarian cancer. With regard to the diagnosis of ovarian cancer, the presence of FDG uptake within the ovary of a postmenopausal woman raises the concern for ovarian cancer. Multiple studies show that FDG PET/CT can detect lymph node and distant metastasis in ovarian cancer with high accuracy and may, therefore, alter the management to obtain better clinical outcomes. Although PET/CT staging is superior for N and M staging of ovarian cancer, its role is limited for T staging. Additionally, FDG PET/CT is of great benefit in evaluating treatment response and has prognostic value in patients with ovarian cancer. FDG PET/CT also has value to detect recurrent disease, particularly in patients with elevated serum CA-125 levels and negative or inconclusive conventional imaging test results. PET/MRI may beneficial for tumor staging because MRI has higher soft tissue contrast and no ionizing radiation exposure compared to CT. Some non-FDG PET radiotracers such as 18 F-fluorothymidine (FLT) or 11 C-methionine (MET) have been studied in preclinical and clinical studies as well and may play a role in the evaluation of patients with ovarian cancer. (orig.)

An update on the role of PET/CT and PET/MRI in ovarian cancer

Energy Technology Data Exchange (ETDEWEB)

Khiewvan, Benjapa [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Mahidol University, Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine Siriraj Hospital, Bangkok (Thailand); Torigian, Drew A.; Emamzadehfard, Sahra; Paydary, Koosha; Salavati, Ali; Houshmand, Sina; Werner, Thomas J.; Alavi, Abass [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States)

2017-06-15

This review article summarizes the role of PET/CT and PET/MRI in ovarian cancer. With regard to the diagnosis of ovarian cancer, the presence of FDG uptake within the ovary of a postmenopausal woman raises the concern for ovarian cancer. Multiple studies show that FDG PET/CT can detect lymph node and distant metastasis in ovarian cancer with high accuracy and may, therefore, alter the management to obtain better clinical outcomes. Although PET/CT staging is superior for N and M staging of ovarian cancer, its role is limited for T staging. Additionally, FDG PET/CT is of great benefit in evaluating treatment response and has prognostic value in patients with ovarian cancer. FDG PET/CT also has value to detect recurrent disease, particularly in patients with elevated serum CA-125 levels and negative or inconclusive conventional imaging test results. PET/MRI may beneficial for tumor staging because MRI has higher soft tissue contrast and no ionizing radiation exposure compared to CT. Some non-FDG PET radiotracers such as {sup 18}F-fluorothymidine (FLT) or {sup 11}C-methionine (MET) have been studied in preclinical and clinical studies as well and may play a role in the evaluation of patients with ovarian cancer. (orig.)

MR-assisted PET motion correction in simultaneous PET/MRI studies of dementia subjects.

Science.gov (United States)

Chen, Kevin T; Salcedo, Stephanie; Chonde, Daniel B; Izquierdo-Garcia, David; Levine, Michael A; Price, Julie C; Dickerson, Bradford C; Catana, Ciprian

2018-03-08

Subject motion in positron emission tomography (PET) studies leads to image blurring and artifacts; simultaneously acquired magnetic resonance imaging (MRI) data provides a means for motion correction (MC) in integrated PET/MRI scanners. To assess the effect of realistic head motion and MR-based MC on static [ 18 F]-fluorodeoxyglucose (FDG) PET images in dementia patients. Observational study. Thirty dementia subjects were recruited. 3T hybrid PET/MR scanner where EPI-based and T 1 -weighted sequences were acquired simultaneously with the PET data. Head motion parameters estimated from high temporal resolution MR volumes were used for PET MC. The MR-based MC method was compared to PET frame-based MC methods in which motion parameters were estimated by coregistering 5-minute frames before and after accounting for the attenuation-emission mismatch. The relative changes in standardized uptake value ratios (SUVRs) between the PET volumes processed with the various MC methods, without MC, and the PET volumes with simulated motion were compared in relevant brain regions. The absolute value of the regional SUVR relative change was assessed with pairwise paired t-tests testing at the P = 0.05 level, comparing the values obtained through different MR-based MC processing methods as well as across different motion groups. The intraregion voxelwise variability of regional SUVRs obtained through different MR-based MC processing methods was also assessed with pairwise paired t-tests testing at the P = 0.05 level. MC had a greater impact on PET data quantification in subjects with larger amplitude motion (higher than 18% in the medial orbitofrontal cortex) and greater changes were generally observed for the MR-based MC method compared to the frame-based methods. Furthermore, a mean relative change of ∼4% was observed after MC even at the group level, suggesting the importance of routinely applying this correction. The intraregion voxelwise variability of regional SUVRs

PET/MRI in cancer patients

DEFF Research Database (Denmark)

Kjær, Andreas; Loft, Annika; Law, Ian

2013-01-01

Combined PET/MRI systems are now commercially available and are expected to change the medical imaging field by providing combined anato-metabolic image information. We believe this will be of particular relevance in imaging of cancer patients. At the Department of Clinical Physiology, Nuclear...... described include brain tumors, pediatric oncology as well as lung, abdominal and pelvic cancer. In general the cases show that PET/MRI performs well in all these types of cancer when compared to PET/CT. However, future large-scale clinical studies are needed to establish when to use PET/MRI. We envision...... that PET/MRI in oncology will prove to become a valuable addition to PET/CT in diagnosing, tailoring and monitoring cancer therapy in selected patient populations....

A new PET detector concept for compact preclinical high-resolution hybrid MR-PET

Science.gov (United States)

Berneking, Arne; Gola, Alberto; Ferri, Alessandro; Finster, Felix; Rucatti, Daniele; Paternoster, Giovanni; Jon Shah, N.; Piemonte, Claudio; Lerche, Christoph

2018-04-01

This work presents a new PET detector concept for compact preclinical hybrid MR-PET. The detector concept is based on Linearly-Graded SiPM produced with current FBK RGB-HD technology. One 7.75 mm x 7.75 mm large sensor chip is coupled with optical grease to a black coated 8 mm x 8 mm large and 3 mm thick monolithic LYSO crystal. The readout is obtained from four readout channels with the linear encoding based on integrated resistors and the Center of Gravity approach. To characterize the new detector concept, the spatial and energy resolutions were measured. Therefore, the measurement setup was prepared to radiate a collimated beam to 25 different points perpendicular to the monolithic scintillator crystal. Starting in the center point of the crystal at 0 mm / 0 mm and sampling a grid with a pitch of 1.75 mm, all significant points of the detector were covered by the collimator beam. The measured intrinsic spatial resolution (FWHM) was 0.74 +/- 0.01 mm in x- and 0.69 +/- 0.01 mm in the y-direction at the center of the detector. At the same point, the measured energy resolution (FWHM) was 13.01 +/- 0.05 %. The mean intrinsic spatial resolution (FWHM) over the whole detector was 0.80 +/- 0.28 mm in x- and 0.72 +/- 0.19 mm in y-direction. The energy resolution (FWHM) of the detector was between 13 and 17.3 % with an average energy resolution of 15.7 +/- 1.0 %. Due to the reduced thickness, the sensitivity of this gamma detector is low but still higher than pixelated designs with the same thickness due to the monolithic crystals. Combining compact design, high spatial resolution, and high sensitivity, the detector concept is particularly suitable for applications where the scanner bore size is limited and high resolution is required - as is the case in small animal hybrid MR-PET.

Pet ownership and physical health.

Science.gov (United States)

Matchock, Robert L

2015-09-01

Pet ownership and brief human-animal interactions can serve as a form of social support and convey a host of beneficial psychological and physiological health benefits. This article critically examines recent relevant literature on the pet-health connection. Cross-sectional studies indicate correlations between pet ownership and numerous aspects of positive health outcomes, including improvements on cardiovascular measures and decreases in loneliness. Quasi-experimental studies and better controlled experimental studies corroborate these associations and suggest that owning and/or interacting with a pet may be causally related to some positive health outcomes. The value of pet ownership and animal-assisted therapy (AAT), as a nonpharmacological treatment modality, augmentation to traditional treatment, and healthy preventive behavior (in the case of pet ownership), is starting to be realized. However, more investigations that employ randomized controlled trials with larger sample sizes and investigations that more closely examine the underlying mechanism of the pet-health effect, such as oxytocin, are needed.

A new cubic phantom for PET/CT dosimetry: Experimental and Monte Carlo characterization

International Nuclear Information System (INIS)

Belinato, Walmir; Silva, Rogerio M.V.; Souza, Divanizia N.; Santos, William S.; Caldas, Linda V.E.; Perini, Ana P.; Neves, Lucio P.

2015-01-01

In recent years, positron emission tomography (PET) associated with multidetector computed tomography (MDCT) has become a diagnostic technique widely disseminated to evaluate various malignant tumors and other diseases. However, during PET/CT examinations, the doses of ionizing radiation experienced by the internal organs of patients may be substantial. To study the doses involved in PET/CT procedures, a new cubic phantom of overlapping acrylic plates was developed and characterized. This phantom has a deposit for the placement of the fluorine-18 fluoro-2-deoxy-D-glucose ( 18 F-FDG) solution. There are also small holes near the faces for the insertion of optically stimulated luminescence dosimeters (OSLD). The holes for OSLD are positioned at different distances from the 18 F-FDG deposit. The experimental results were obtained in two PET/CT devices operating with different parameters. Differences in the absorbed doses were observed in OSLD measurements due to the non-orthogonal positioning of the detectors inside the phantom. This phantom was also evaluated using Monte Carlo simulations, with the MCNPX code. The phantom and the geometrical characteristics of the equipment were carefully modeled in the MCNPX code, in order to develop a new methodology form comparison of experimental and simulated results, as well as to allow the characterization of PET/CT equipments in Monte Carlo simulations. All results showed good agreement, proving that this new phantom may be applied for these experiments. (authors)

A new cubic phantom for PET/CT dosimetry: Experimental and Monte Carlo characterization

Energy Technology Data Exchange (ETDEWEB)

Belinato, Walmir [Departamento de Ensino, Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia, Campus Vitoria da Conquista, Zabele, Av. Amazonas 3150, 45030-220 Vitoria da Conquista, BA (Brazil); Silva, Rogerio M.V.; Souza, Divanizia N. [Departamento de Fisica, Universidade Federal de Sergipe-UFS, Sao Cristovao, Sergipe (Brazil); Santos, William S.; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo SP (Brazil); Perini, Ana P.; Neves, Lucio P. [Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo SP (Brazil); Instituto de Fisica, Universidade Federal de Uberlandia, Caixa Postal 593, 38400-902, Uberlandia, MG (Brazil)

2015-07-01

In recent years, positron emission tomography (PET) associated with multidetector computed tomography (MDCT) has become a diagnostic technique widely disseminated to evaluate various malignant tumors and other diseases. However, during PET/CT examinations, the doses of ionizing radiation experienced by the internal organs of patients may be substantial. To study the doses involved in PET/CT procedures, a new cubic phantom of overlapping acrylic plates was developed and characterized. This phantom has a deposit for the placement of the fluorine-18 fluoro-2-deoxy-D-glucose ({sup 18}F-FDG) solution. There are also small holes near the faces for the insertion of optically stimulated luminescence dosimeters (OSLD). The holes for OSLD are positioned at different distances from the {sup 18}F-FDG deposit. The experimental results were obtained in two PET/CT devices operating with different parameters. Differences in the absorbed doses were observed in OSLD measurements due to the non-orthogonal positioning of the detectors inside the phantom. This phantom was also evaluated using Monte Carlo simulations, with the MCNPX code. The phantom and the geometrical characteristics of the equipment were carefully modeled in the MCNPX code, in order to develop a new methodology form comparison of experimental and simulated results, as well as to allow the characterization of PET/CT equipments in Monte Carlo simulations. All results showed good agreement, proving that this new phantom may be applied for these experiments. (authors)

MRI-assisted PET motion correction for neurologic studies in an integrated MR-PET scanner.

Science.gov (United States)

Catana, Ciprian; Benner, Thomas; van der Kouwe, Andre; Byars, Larry; Hamm, Michael; Chonde, Daniel B; Michel, Christian J; El Fakhri, Georges; Schmand, Matthias; Sorensen, A Gregory

2011-01-01

Head motion is difficult to avoid in long PET studies, degrading the image quality and offsetting the benefit of using a high-resolution scanner. As a potential solution in an integrated MR-PET scanner, the simultaneously acquired MRI data can be used for motion tracking. In this work, a novel algorithm for data processing and rigid-body motion correction (MC) for the MRI-compatible BrainPET prototype scanner is described, and proof-of-principle phantom and human studies are presented. To account for motion, the PET prompt and random coincidences and sensitivity data for postnormalization were processed in the line-of-response (LOR) space according to the MRI-derived motion estimates. The processing time on the standard BrainPET workstation is approximately 16 s for each motion estimate. After rebinning in the sinogram space, the motion corrected data were summed, and the PET volume was reconstructed using the attenuation and scatter sinograms in the reference position. The accuracy of the MC algorithm was first tested using a Hoffman phantom. Next, human volunteer studies were performed, and motion estimates were obtained using 2 high-temporal-resolution MRI-based motion-tracking techniques. After accounting for the misalignment between the 2 scanners, perfectly coregistered MRI and PET volumes were reproducibly obtained. The MRI output gates inserted into the PET list-mode allow the temporal correlation of the 2 datasets within 0.2 ms. The Hoffman phantom volume reconstructed by processing the PET data in the LOR space was similar to the one obtained by processing the data using the standard methods and applying the MC in the image space, demonstrating the quantitative accuracy of the procedure. In human volunteer studies, motion estimates were obtained from echo planar imaging and cloverleaf navigator sequences every 3 s and 20 ms, respectively. Motion-deblurred PET images, with excellent delineation of specific brain structures, were obtained using these 2 MRI

Staging performance of whole-body DWI, PET/CT and PET/MRI in invasive ductal carcinoma of the breast.

Science.gov (United States)

Catalano, Onofrio Antonio; Daye, Dania; Signore, Alberto; Iannace, Carlo; Vangel, Mark; Luongo, Angelo; Catalano, Marco; Filomena, Mazzeo; Mansi, Luigi; Soricelli, Andrea; Salvatore, Marco; Fuin, Niccolo; Catana, Ciprian; Mahmood, Umar; Rosen, Bruce Robert

2017-07-01

The aim of the present study was to evaluate the performance of whole-body diffusion-weighted imaging (WB-DWI), whole-body positron emission tomography with computed tomography (WB-PET/CT), and whole-body positron emission tomography with magnetic resonance imaging (WB-PET/MRI) in staging patients with untreated invasive ductal carcinoma of the breast. Fifty-one women with newly diagnosed invasive ductal carcinoma of the breast underwent WB-DWI, WB-PET/CT and WB-PET/MRI before treatment. A radiologist and a nuclear medicine physician reviewed in consensus the images from the three modalities and searched for occurrence, number and location of metastases. Final staging, according to each technique, was compared. Pathology and imaging follow-up were used as the reference. WB-DWI, WB-PET/CT and WB-PET/MRI correctly and concordantly staged 33/51 patients: stage IIA in 7 patients, stage IIB in 8 patients, stage IIIC in 4 patients and stage IV in 14 patients. WB-DWI, WB-PET/CT and WB-PET/MRI incorrectly and concordantly staged 1/51 patient as stage IV instead of IIIA. Discordant staging was reported in 17/51 patients. WB-PET/MRI resulted in improved staging when compared to WB-PET/CT (50 correctly staged on WB-PET/MRI vs. 38 correctly staged on WB-PET/CT; McNemar's test; p<0.01). Comparing the performance of WB-PET/MRI and WB-DWI (43 correct) did not reveal a statistically significant difference (McNemar test, p=0.14). WB-PET/MRI is more accurate in the initial staging of breast cancer than WB-DWI and WB-PET/CT, however, the discrepancies between WB-PET/MRI and WB-DWI were not statistically significant. When available, WB-PET/MRI should be considered for staging patient with invasive ductal breast carcinoma.

Pet ownership, dog types and attachment to pets in 9-10 year old children in Liverpool, UK.

Science.gov (United States)

Westgarth, Carri; Boddy, Lynne M; Stratton, Gareth; German, Alexander J; Gaskell, Rosalind M; Coyne, Karen P; Bundred, Peter; McCune, Sandra; Dawson, Susan

2013-05-13

Little is known about ethnic, cultural and socioeconomic differences in childhood ownership and attitudes to pets. The objective of this study was to describe the factors associated with living with different pet types, as well as factors that may influence the intensity of relationship or 'attachment' that children have to their pet. Data were collected using a survey of 1021 9-10 year old primary school children in a deprived area of the city of Liverpool, UK. Dogs were the most common pet owned, most common 'favourite' pet, and species most attached to. Twenty-seven percent of dog-owning children (10% of all children surveyed) reported living with a 'Bull Breed' dog (which includes Pit Bulls and Staffordshire Bull Terriers), and the most popular dog breed owned was the Staffordshire Bull Terrier. Multivariable regression modelling identified a number of variables associated with ownership of different pets and the strength of attachment to the child's favourite pet. Girls were more likely to own most pet types, but were no more or less attached to their favourite pet than boys. Children of white ethnicity were more likely to own dogs, rodents and 'other' pets but were no more or less attached to their pets than children of non-white ethnicity. Single and youngest children were no more or less likely to own pets than those with younger brothers and sisters, but they showed greater attachment to their pets. Children that owned dogs lived in more deprived areas than those without dogs, and deprivation increased with number of dogs owned. 'Pit Bull or cross' and 'Bull Breed' dogs were more likely to be found in more deprived areas than other dog types. Non-whites were also more likely to report owning a 'Pit Bull or cross' than Whites. Gender, ethnicity and socioeconomic status were associated with pet ownership, and sibling status with level of attachment to the pet. These are important to consider when conducting research into the health benefits and risks of the

Application of PET in breast cancer

International Nuclear Information System (INIS)

Noh, Dong Young

2002-01-01

Positron emission tomography (PET) is an imaging method that employs radionuclide and tomography techniques. Since 1995, we applied PET not only to the diagnosis of breast cancer but also to the detection of abnormalities in the augmented breast and to the detection of metastasis. Until 2001, we evaluated 242 breast cases by PET at PET center of Seoul National University Hospital. Our group has reported serially at the international journals. In the firtst report, PET showed high sensitivity for detecting breast cancer, both the primary and axillary node metastasis. A total of 27 patients underwent breast operations based on PET results at Seoul National University Hospital from 1995 to 1996. The diagnostic accuracy of PET were 97% for the primary tumor mass and 96% for axillary lymph node metastasis. In case of the breast augmented, PET also showed excellent diagnostic results for primary breast cancer and axillary lymph node metastasis where mammography and ultrasound could not diagnose properly. PET also had outstanding results in the detection of recurrent or metastatic breast cancer(sensitivity 94%, specificity 80%, accuracy 89%). In addition, our study gave some evidence that PET could be applied further to evaluate the growth rate of tumors by measuring SUV, and finally to prognosticated the disease. PET could also be applied to evaluate the response after chemotherapy to measure its metabolic rate and size. In conclsion, PET is a highly sensitive, accurate diagnostic tool for breast cancer of primary lesion in various conditions including metastasis

Use of the CT component of PET-CT to improve PET-MR registration: demonstration in soft-tissue sarcoma

International Nuclear Information System (INIS)

Somer, Edward J; Benatar, Nigel A; O'Doherty, Michael J; Smith, Mike A; Marsden, Paul K

2007-01-01

We have investigated improvements to PET-MR image registration offered by PET-CT scanning. Ten subjects with suspected soft-tissue sarcomas were scanned with an in-line PET-CT and a clinical MR scanner. PET to CT, CT to MR and PET to MR image registrations were performed using a rigid-body external marker technique and rigid and non-rigid voxel-similarity algorithms. PET-MR registration was also performed using transformations derived from the registration of CT to MR. The external marker technique gave fiducial registration errors of 2.1 mm, 5.1 mm and 5.3 mm for PET-CT, PET-MR and CT-MR registration. Target registration errors were 3.9 mm, 9.0 mm and 9.3 mm, respectively. Voxel-based algorithms were evaluated by measuring the distance between corresponding fiducials after registration. Registration errors of 6.4 mm, 14.5 mm and 9.5 mm, respectively, for PET-CT, PET-MR and CT-MR were observed for rigid-body registration while non-rigid registration gave errors of 6.8 mm, 16.3 mm and 7.6 mm for the same modality combinations. The application of rigid and non-rigid CT to MR transformations to accompanying PET data gives significantly reduced PET-MR errors of 10.0 mm and 8.5 mm, respectively. Visual comparison by two independent observers confirmed the improvement over direct PET-MR registration. We conclude that PET-MR registration can be more accurately and reliably achieved using the hybrid technique described than through direct rigid-body registration of PET to MR

Pets and Parasites

Science.gov (United States)

... good news is that this rarely happens. Most pet-to-people diseases can be avoided by following a few ... your doctor Can a parasite cause death in people and pets? Can human disease from a parasite be treated ...

PET motion correction in context of integrated PET/MR: Current techniques, limitations, and future projections.

Science.gov (United States)

Gillman, Ashley; Smith, Jye; Thomas, Paul; Rose, Stephen; Dowson, Nicholas

2017-12-01

Patient motion is an important consideration in modern PET image reconstruction. Advances in PET technology mean motion has an increasingly important influence on resulting image quality. Motion-induced artifacts can have adverse effects on clinical outcomes, including missed diagnoses and oversized radiotherapy treatment volumes. This review aims to summarize the wide variety of motion correction techniques available in PET and combined PET/CT and PET/MR, with a focus on the latter. A general framework for the motion correction of PET images is presented, consisting of acquisition, modeling, and correction stages. Methods for measuring, modeling, and correcting motion and associated artifacts, both in literature and commercially available, are presented, and their relative merits are contrasted. Identified limitations of current methods include modeling of aperiodic and/or unpredictable motion, attaining adequate temporal resolution for motion correction in dynamic kinetic modeling acquisitions, and maintaining availability of the MR in PET/MR scans for diagnostic acquisitions. Finally, avenues for future investigation are discussed, with a focus on improvements that could improve PET image quality, and that are practical in the clinical environment. © 2017 American Association of Physicists in Medicine.

PET/MR Imaging in Gynecologic Oncology.

Science.gov (United States)

Ohliger, Michael A; Hope, Thomas A; Chapman, Jocelyn S; Chen, Lee-May; Behr, Spencer C; Poder, Liina

2017-08-01

MR imaging and PET using 2-Deoxy-2-[ 18 F]fluoroglucose (FDG) are both useful in the evaluation of gynecologic malignancies. MR imaging is superior for local staging of disease whereas fludeoxyglucose FDG PET is superior for detecting distant metastases. Integrated PET/MR imaging scanners have great promise for gynecologic malignancies by combining the advantages of each modality into a single scan. This article reviews the technology behind PET/MR imaging acquisitions and technical challenges relevant to imaging the pelvis. A dedicated PET/MR imaging protocol; the roles of PET and MR imaging in cervical, endometrial, and ovarian cancers; and future directions for PET/MR imaging are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

MR Imaging-Guided Attenuation Correction of PET Data in PET/MR Imaging.

Science.gov (United States)

Izquierdo-Garcia, David; Catana, Ciprian

2016-04-01

Attenuation correction (AC) is one of the most important challenges in the recently introduced combined PET/magnetic resonance (MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients of the tissues and other components located in the PET field of view. MR-AC methods can be divided into 3 categories: segmentation, atlas, and PET based. This review provides a comprehensive list of the state-of-the-art MR-AC approaches and their pros and cons. The main sources of artifacts are presented. Finally, this review discusses the current status of MR-AC approaches for clinical applications. Copyright © 2016 Elsevier Inc. All rights reserved.

Role of FDG-PET and PET/CT in the diagnosis and management of vasculitis

Energy Technology Data Exchange (ETDEWEB)

Zerizer, Imene; Tan, Kathryn; Khan, Sameer; Barwick, Tara [Department of Nuclear Medicine, Imperial College Healthcare, Hammersmith Hospital, Du Cane Road, London (United Kingdom); Marzola, Maria Cristina [Department of Nuclear Medicine, PET/CT Centre, Radiology and Medical Physics, ' Santa Maria della Misericordia' Hospital, Rovigo (Italy); Rubello, Domenico [Department of Nuclear Medicine, PET/CT Centre, Radiology and Medical Physics, ' Santa Maria della Misericordia' Hospital, Rovigo (Italy)], E-mail: domenico.rubello@libero.it; Al-Nahhas, Adil [Department of Nuclear Medicine, Imperial College Healthcare, Hammersmith Hospital, Du Cane Road, London (United Kingdom)

2010-03-15

Purpose: to investigate the role of FDG-PET and PET/CT in the evaluation of vasculitis. Materials and methods: a systematic revision of the papers published in PubMed/Medline until December 2009 was done. Results: FDG-PET and PET/CT have been proven to be valuable in the diagnosis of large-vessel vasculitis, especially giant cells arteritis with sensitivity values ranging 77% to 92%, and specificity values ranging 89% to 100%. In particular, FDG-PET/CT has demonstrated the potential to non-invasively diagnose the onset of the vasculitis earlier than traditional anatomical imaging techniques, thus enabling prompt treatment. False positive results mainly occur in the differential diagnosis between vasculitis and atherosclerotic vessels in elderly patients. Another area where FDG-PET/CT is gaining wider acceptance is in monitoring response to therapy; it can reliably detect the earliest changes of disease improvement post-therapy, and persistent activity is an indicator of non-responders to therapy. A few data have been reported about medium/small vessel vasculitis. Discussion: FDG-PET and PET/CT have proven utility: (a) in the initial diagnosis of patients suspected of having vasculitis particularly in those who present with non-specific symptoms; (b) in the identification of areas of increased FDG uptake in which a biopsy should be done for obtaining a diagnosis; (c) in evaluating the extent of the disease; (d) in assessing response to treatment.

Role of FDG-PET and PET/CT in the diagnosis and management of vasculitis

International Nuclear Information System (INIS)

Zerizer, Imene; Tan, Kathryn; Khan, Sameer; Barwick, Tara; Marzola, Maria Cristina; Rubello, Domenico; Al-Nahhas, Adil

2010-01-01

Purpose: to investigate the role of FDG-PET and PET/CT in the evaluation of vasculitis. Materials and methods: a systematic revision of the papers published in PubMed/Medline until December 2009 was done. Results: FDG-PET and PET/CT have been proven to be valuable in the diagnosis of large-vessel vasculitis, especially giant cells arteritis with sensitivity values ranging 77% to 92%, and specificity values ranging 89% to 100%. In particular, FDG-PET/CT has demonstrated the potential to non-invasively diagnose the onset of the vasculitis earlier than traditional anatomical imaging techniques, thus enabling prompt treatment. False positive results mainly occur in the differential diagnosis between vasculitis and atherosclerotic vessels in elderly patients. Another area where FDG-PET/CT is gaining wider acceptance is in monitoring response to therapy; it can reliably detect the earliest changes of disease improvement post-therapy, and persistent activity is an indicator of non-responders to therapy. A few data have been reported about medium/small vessel vasculitis. Discussion: FDG-PET and PET/CT have proven utility: (a) in the initial diagnosis of patients suspected of having vasculitis particularly in those who present with non-specific symptoms; (b) in the identification of areas of increased FDG uptake in which a biopsy should be done for obtaining a diagnosis; (c) in evaluating the extent of the disease; (d) in assessing response to treatment.

AX-PET: A novel PET concept with G-APD readout

CERN Document Server

Heller, M; Casella, C; Chesi, E; De Leo, R; Dissertori, G; Fanti, V; Gillam, J E; Joram, C; Lustermann, W; Nappi, E; Oliver, J F; Pauss, F; Rafecas, M; Rudge, A; Ruotsalainen, U; Schinzel, D; Schneider, T; Seguinot, J; Solevi, P; Stapnes, S; Tuna, U; Weilhammer, P

2012-01-01

The AX-PET collaboration has developed a novel concept for high resolution PET imaging to overcome some of the performance limitations of classical PET cameras, in particular the compromise between spatial resolution and sensitivity introduced by the parallax error. The detector consists of an arrangement of long LYSO scintillating crystals axially oriented around the field of view together with arrays of wave length shifter strips orthogonal to the crystals. This matrix allows a precise 3D measurement of the photon interaction point. This is valid both for photoelectric absorption at 511 key and for Compton scattering down to deposited energies of about 100 keV. Crystals and WLS strips are individually read out using Geiger-mode Avalanche Photo Diodes (G-APDs). The sensitivity of such a detector can be adjusted by changing the number of layers and the resolution is defined by the crystal and strip dimensions. Two AX-PET modules were built and fully characterized in dedicated test set-ups at CERN, with point-...

Dynamic comparison of PET imaging performance between state-of-the-art ToF-PET/CT and ToF-PET/MR scanners

International Nuclear Information System (INIS)

Delso, Gaspar; Deller, Tim; Khalighi, Mehdi; Veit-Haibach, Patrick; Schulthess, Gustav von

2014-01-01

The goal of the present work was to determine the potential for dose reduction in a new clinical ToF-PET/MR scanner. This was achieved by means of long dynamic phantom acquisitions designed to provide a fair comparison of image quality and lesion detectability, as a function of activity, between the new PET/MR system and a state-of-the art PET/CT.

Use of PET and PET/CT for Radiation Therapy Planning: IAEA expert report 2006-2007

International Nuclear Information System (INIS)

MacManus, Michael; Nestle, Ursula; Rosenzweig, Kenneth E.; Carrio, Ignasi; Messa, Cristina; Belohlavek, Otakar; Danna, Massimo; Inoue, Tomio; Deniaud-Alexandre, Elizabeth; Schipani, Stefano; Watanabe, Naoyuki; Dondi, Maurizio; Jeremic, Branislav

2009-01-01

Positron Emission Tomography (PET) is a significant advance in cancer imaging with great potential for optimizing radiation therapy (RT) treatment planning and thereby improving outcomes for patients. The use of PET and PET/CT in RT planning was reviewed by an international panel. The International Atomic Energy Agency (IAEA) organized two synchronized and overlapping consultants' meetings with experts from different regions of the world in Vienna in July 2006. Nine experts and three IAEA staff evaluated the available data on the use of PET in RT planning, and considered practical methods for integrating it into routine practice. For RT planning, 18 F fluorodeoxyglucose (FDG) was the most valuable pharmaceutical. Numerous studies supported the routine use of FDG-PET for RT target volume determination in non-small cell lung cancer (NSCLC). There was also evidence for utility of PET in head and neck cancers, lymphoma and in esophageal cancers, with promising preliminary data in many other cancers. The best available approach employs integrated PET/CT images, acquired on a dual scanner in the radiotherapy treatment position after administration of tracer according to a standardized protocol, with careful optimization of images within the RT planning system and carefully considered rules for contouring tumor volumes. PET scans that are not recent or were acquired without proper patient positioning should be repeated for RT planning. PET will play an increasing valuable role in RT planning for a wide range of cancers. When requesting PET scans, physicians should be aware of their potential role in RT planning.

PET/CT with intravenous contrast can be used for PET attenuation correction in cancer patients

International Nuclear Information System (INIS)

Berthelsen, A.K.; Holm, S.; Loft, A.; Klausen, T.L.; Andersen, F.; Hoejgaard, L.

2005-01-01

If the CT scan of a combined PET/CT study is performed as a full diagnostic quality CT scan including intravenous (IV) contrast agent, the quality of the joint PET/CT procedure is improved and a separate diagnostic CT scan can be avoided. CT with IV contrast can be used for PET attenuation correction, but this may result in a bias in the attenuation factors. The clinical significance of this bias has not been established. Our aim was to perform a prospective clinical study where each patient had CT performed with and without IV contrast agent to establish whether PET/CT with IV contrast can be used for PET attenuation without reducing the clinical value of the PET scan. A uniform phantom study was used to document that the PET acquisition itself is not significantly influenced by the presence of IV contrast medium. Then, 19 patients referred to PET/CT with IV contrast underwent CT scans without, and then with contrast agent, followed by an 18 F-fluorodeoxyglucose whole-body PET scan. The CT examinations were performed with identical parameters on a GE Discovery LS scanner. The PET data were reconstructed with attenuation correction based on the two CT data sets. A global comparison of standard uptake value (SUV) was performed, and SUVs in tumour, in non-tumour tissue and in the subclavian vein were calculated. Clinical evaluation of the number and location of lesions on all PET/CT scans was performed twice, blinded and in a different random order, by two independent nuclear medicine specialists. In all patients, the measured global SUV of PET images based on CT with IV contrast agent was higher than the global activity using non-contrast correction. The overall increase in the mean SUV (for two different conversion tables tested) was 4.5±2.3% and 1.6±0.5%, respectively. In 11/19 patients, focal uptake was identified corresponding to malignant tumours. Eight out of 11 tumours showed an increased SUV max (2.9±3.1%) on the PET images reconstructed using IV contrast

Value of new MR techniques in MR-PET; Stellenwert neuer MR-Techniken in der MR-PET

Energy Technology Data Exchange (ETDEWEB)

Attenberger, U.I.; Schoenberg, S.O. [Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim der Universitaet Heidelberg, Institut fuer klinische Radiologie und Nuklearmedizin, Mannheim (Germany); Quick, H.H. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Institut fuer Medizinische Physik, Erlangen (Germany); Guimaraes, A. [Massachusetts General Hospital, Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown (United States); Catalano, O. [University of Naples Federico II, Naples (Italy); Morelli, J.N. [The Johns Hopkins Hospital, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore (United States)

2013-12-15

The unparalleled soft tissue contrast of magnetic resonance imaging (MRI) and the functional information obtainable with 18-F fluorodeoxyglucose positron emission tomography (FDG-PET) render MR-PET well-suited for oncological and psychiatric imaging. The lack of ionizing radiation with MRI also makes MR-PET a promising modality for oncology patients requiring frequent follow-up and pediatric patients. Lessons learned with PET computed tomography (CT) over the last few years do not directly translate to MR-PET. For example, in PET-CT the Hounsfield units derived from CT are used for attenuation correction (AC). As 511 keV photons emitted in PET examinations are attenuated by the patient's body CT data are converted directly to linear attenuation coefficients (LAC); however, proton density measured by MRI is not directly related to the radiodensity or LACs of biological tissue. Thus, direct conversion to LAC data is not possible making AC more challenging in simultaneous MRI-PET scanning. In addition to these constraints simultaneous MRI-PET acquisitions also improve on some solutions to well-known challenges of hybrid imaging techniques, such as limitations in motion correction. This article reports on initial clinical experiences with simultaneously acquired MRI-PET data, focusing on the potential benefits and limitations of MRI with respect to motion correction as well as metal and attenuation correction artefacts. (orig.) [German] Die klinische Implementierung der neuen Hybridtechnologie MR-Positronenemissionstomographie (MR-PET) bietet durch die Kombination aus hochaufloesender Morphologie, Funktion und Metabolismus bisher ungeahnte diagnostische Moeglichkeiten, die nicht nur fuer die Diagnose und die Verlaufskontrolle onkologischer und psychiatrischer Erkrankungen von hoher Bedeutung sind. Verglichen mit der PET-CT wird dies mit reduzierter Strahlenbelastung fuer den Patienten moeglich, was wiederum insbesondere fuer Patienten in der Tumornachsorge, die

Oncologic PET/CT: current status and controversies

International Nuclear Information System (INIS)

Siegel, B.A.; Dehdashti, F.

2005-01-01

The introduction of integrated PET/CT has dramatically increased the worldwide rate of growth for PET, predominantly for oncologic imaging with the glucose analog 18 F-fluorodeoxyglucose (FDG). A rapidly expanding body of literature demonstrates that the use FDG-PET/CT and the resultant ability to interpret coregistered and fused PET and CT images lead to improved observer confidence and improved diagnostic performance by comparison with PET alone, CT alone, and visually correlated PET and CT. The value of PET/CT is likely to be even greater with new PET radiopharmaceuticals under development, many of which produce PET images with even fewer anatomical landmarks than FDG images. PET/CT is also likely to lead to the resurrection of 18 F-fluoride as a principal agent for radionuclide bone imaging. There are a number of controversies related to PET/CT, including minimum training and experience requirements for interpreting physicians and defining new models for technical and professional reimbursement. (orig.)

Gamma camera based FDG PET in oncology

International Nuclear Information System (INIS)

Park, C. H.

2002-01-01

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

Extended suicide with a pet.

Science.gov (United States)

Cooke, Brian K

2013-01-01

The combination of the killing of a pet and a suicide is a perplexing scenario that is largely unexplored in the literature. Many forensic psychiatrists and psychologists may be unaccustomed to considering the significance of the killing of a pet. The subject is important, however, because many people regard their pets as members of their family. A case is presented of a woman who killed her pet dog and herself by carbon monoxide poisoning. The purpose of this article is to provide an initial exploration of the topic of extended suicide with a pet. Forensic mental health evaluations may have a role in understanding the etiology of this event and in opining as to the culpability of individuals who attempt to or successfully kill a pet and then commit suicide. Because the scientific literature is lacking, there is a need to understand this act from a variety of perspectives. First, a social and anthropological perspective will be presented that summarizes the history of the practice of killing of one's pet, with a focus on the ancient Egyptians. A clinical context will examine what relationship animals have to mental illness. A vast body of existing scientific data showing the relevance of human attachment to pets suggests that conclusions from the phenomena of homicide-suicide and filicide-suicide are applicable to extended suicide with a pet. Finally, recommendations will be proposed for both clinical and forensic psychiatrists faced with similar cases.

Cyclotron/PET project in Uruguay

International Nuclear Information System (INIS)

Engler, H.

2006-01-01

The Positron Computed Tomography (PET) is a tri dimensional image technique which shows biochemical information. PET is used in neurology and cardiology diseases. The National Center Cyclotron PET has been found to research, development and health science applications.

Simulation study comparing the helmet-chin PET with a cylindrical PET of the same number of detectors

Science.gov (United States)

Ahmed, Abdella M.; Tashima, Hideaki; Yoshida, Eiji; Nishikido, Fumihiko; Yamaya, Taiga

2017-06-01

There is a growing interest in developing brain PET scanners with high sensitivity and high spatial resolution for early diagnosis of neurodegenerative diseases and studies of brain functions. Sensitivity of the PET scanner can be improved by increasing the solid angle. However, conventional PET scanners are designed based on a cylindrical geometry, which may not be the most efficient design for brain imaging in terms of the balance between sensitivity and cost. We proposed a dedicated brain PET scanner based on a hemispheric shape detector and a chin detector (referred to as the helmet-chin PET), which is designed to maximize the solid angle by increasing the number of lines-of-response in the hemisphere. The parallax error, which PET scanners with a large solid angle tend to have, can be suppressed by the use of depth-of-interaction detectors. In this study, we carry out a realistic evaluation of the helmet-chin PET using Monte Carlo simulation based on the 4-layer GSO detector which consists of a 16  ×  16  ×  4 array of crystals with dimensions of 2.8  ×  2.8  ×  7.5 mm3. The purpose of this simulation is to show the gain in imaging performance of the helmet-chin PET compared with the cylindrical PET using the same number of detectors in each configuration. The sensitivity of the helmet-chin PET evaluated with a cylindrical phantom has a significant increase, especially at the top of the (field-of-view) FOV. The peak-NECR of the helmet-chin PET is 1.4 times higher compared to the cylindrical PET. The helmet-chin PET provides relatively low noise images throughout the FOV compared to the cylindrical PET which exhibits enhanced noise at the peripheral regions. The results show the helmet-chin PET can significantly improve the sensitivity and reduce the noise in the reconstructed images.

Effect of MR contrast agents on quantitative accuracy of PET in combined whole-body PET/MR imaging

Energy Technology Data Exchange (ETDEWEB)

Lois, Cristina [University of Santiago de Compostela, Department of Particle Physics, Santiago de Compostela (Spain); Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela (Spain); Imaging Science Institute, Tuebingen (Germany); Bezrukov, Ilja [Eberhard Karls University, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens Foundation, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Max Plank Institute for Intelligent Systems, Department of Empirical Inference, Tuebingen (Germany); Schmidt, Holger [Eberhard Karls University, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens Foundation, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Schwenzer, Nina; Werner, Matthias K. [Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Kupferschlaeger, Juergen [Eberhard Karls University, Nuclear Medicine, Department of Radiology, Tuebingen (Germany); Beyer, Thomas [Imaging Science Institute, Tuebingen (Germany); cmi-experts GmbH, Zuerich (Switzerland)

2012-11-15

Clinical PET/MR acquisition protocols entail the use of MR contrast agents (MRCA) that could potentially affect PET quantification following MR-based attenuation correction (AC). We assessed the effect of oral and intravenous (IV) MRCA on PET quantification in PET/MR imaging. We employed two MRCA: Lumirem {sup registered} (oral) and Gadovist {sup registered} (IV). First, we determined their reference PET attenuation values using a PET transmission scan (ECAT-EXACT HR+, Siemens) and a CT scan (PET/CT Biograph 16 HI-REZ, Siemens). Second, we evaluated the attenuation of PET signals in the presence of MRCA. Phantoms were filled with clinically relevant concentrations of MRCA in a background of water and {sup 18}F-fluoride, and imaged using a PET/CT scanner (Biograph 16 HI-REZ, Siemens) and a PET/MR scanner (Biograph mMR, Siemens). Third, we investigated the effect of clinically relevant volumes of MRCA on MR-based AC using human pilot data: a patient study employing Gadovist {sup registered} (IV) and a volunteer study employing two different oral MRCA (Lumirem {sup registered} and pineapple juice). MR-based attenuation maps were calculated following Dixon-based fat-water segmentation and an external atlas-based and pattern recognition (AT and PR) algorithm. IV and oral MRCA in clinically relevant concentrations were found to have PET attenuation values similar to those of water. The phantom experiments showed that under clinical conditions IV and oral MRCA did not yield additional attenuation of PET emission signals. Patient scans showed that PET attenuation maps are not biased after the administration of IV MRCA but may be biased, however, after ingestion of iron oxide-based oral MRCA when segmentation-based AC algorithms are used. Alternative AC algorithms, such as AT and PR, or alternative oral contrast agents, such as pineapple juice, can yield unbiased attenuation maps. In clinical PET/MR scenarios MRCA are not expected to lead to markedly increased attenuation

Time-of-flight positron emission tomography using optical fiber circuit

International Nuclear Information System (INIS)

Yamawaki, Masato; Katsumura, Yousuke; Suzuki, Takenori

2008-01-01

The measurement method and system architecture of a new time-of-flight positron emission tomography (TOF-PET) system are proposed. This system collects scintillation light using optical fibers connected directly to scintillators and measures the position of positron annihilation. Many scintillators are placed cylindrically whereby a pair of scintillators detects a pair of γ-rays generated at the positron annihilation point. Optical fiber circuits, most of which are bundles of optical fibers bound clockwise or counterclockwise around the cylinder of scintillators, collect light signals generated by γ-rays. These light signals are amplified by several photomultiplier tubes and processed using a single digital oscilloscope to determine the TOF of the positron annihilation γ-rays. One of the most important factors in the performance of the TOF-PET system is the TOF resolution. When fiber circuits are used for transmitting light signals, the dispersion of light signals and the decrease in light intensity are the major factors in the deterioration of the TOF resolution. The result of the preliminary experiment leads to the conclusion that the use of optical fibers degrades the intensity of light but does not severely degrade the TOF resolution. (author)

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

International Nuclear Information System (INIS)

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

2017-01-01

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. (orig.)

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

Energy Technology Data Exchange (ETDEWEB)

Brendel, Matthias; Schnabel, Jonas; Wagner, Leonie; Brendel, Eva; Meyer-Wilmes, Johanna; Unterrainer, Marcus [University Hospital, LMU Munich, Department of Nuclear Medicine, Munich (Germany); Schoenecker, Sonja; Prix, Catharina; Ackl, Nibal [University Hospital, LMU Munich, Department of Neurology, Munich (Germany); Schildan, Andreas; Patt, Marianne; Barthel, Henryk; Sabri, Osama [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Catak, Cihan [Klinikum der Universitaet Muenchen, Institute for Stroke and Dementia Research, Munich (Germany); Pogarell, Oliver [University Hospital, LMU Munich, Department of Psychiatry, Munich (Germany); Levin, Johannes; Danek, Adrian [University Hospital, LMU Munich, Department of Neurology, Munich (Germany); DZNE - German Center for Neurodegenerative Diseases, Munich (Germany); Buerger, Katharina [Klinikum der Universitaet Muenchen, Institute for Stroke and Dementia Research, Munich (Germany); DZNE - German Center for Neurodegenerative Diseases, Munich (Germany); Bartenstein, Peter; Rominger, Axel [University Hospital, LMU Munich, Department of Nuclear Medicine, Munich (Germany); Munich Cluster for Systems Neurology (SyNergy), Munich (Germany)

2017-12-15

In recent years, several [{sup 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 [{sup 18}F]-florbetaben (FBB)-PET on the diagnostic management of patients with suspected dementia that was still unclarified after [{sup 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. (orig.)

64Cu-Labeled LyP-1-Dendrimer for PET-CT Imaging of Atherosclerotic Plaque

Science.gov (United States)

2015-01-01

The ability to detect and quantify macrophage accumulation can provide important diagnostic and prognostic information for atherosclerotic plaque. We have previously shown that LyP-1, a cyclic 9-amino acid peptide, binds to p32 proteins on activated macrophages, facilitating the visualization of atherosclerotic plaque with PET. Yet, the in vivo plaque accumulation of monomeric [18F]FBA-LyP-1 was low (0.31 ± 0.05%ID/g). To increase the avidity of LyP-1 constructs to p32, we synthesized a dendritic form of LyP-1 on solid phase using lysine as the core structural element. Imaging probes (FAM or 6-BAT) were conjugated to a lysine or cysteine on the dendrimer for optical and PET studies. The N-terminus of the dendrimer was further modified with an aminooxy group in order to conjugate LyP-1 and ARAL peptides bearing a ketone. Oxime ligation of peptides to both dendrimers resulted in (LyP-1)4- and (ARAL)4-dendrimers with optical (FAM) and PET probes (6-BAT). For PET-CT studies, (LyP-1)4- and (ARAL)4-dendrimer-6-BAT were labeled with 64Cu (t1/2 = 12.7 h) and intravenously injected into the atherosclerotic (ApoE–/–) mice. After two hours of circulation, PET-CT coregistered images demonstrated greater uptake of the (LyP-1)4-dendrimer-64Cu than the (ARAL)4-dendrimer-64Cu in the aortic root and descending aorta. Ex vivo images and the biodistribution acquired at three hours after injection also demonstrated a significantly higher uptake of the (LyP-1)4-dendrimer-64Cu (1.1 ± 0.26%ID/g) than the (ARAL)4-dendrimer-64Cu (0.22 ± 0.05%ID/g) in the aorta. Similarly, subcutaneous injection of the LyP-1-dendrimeric carriers resulted in preferential accumulation in plaque-containing regions over 24 h. In the same model system, ex vivo fluorescence images within aortic plaque depict an increased accumulation and penetration of the (LyP-1)4-dendrimer-FAM as compared to the (ARAL)4-dendrimer-FAM. Taken together, the results suggest that the (LyP-1)4-dendrimer can be applied for in

Business administration of PET facilities. A nationwide survey for prices of PET screening and a cost analysis of three facilities

International Nuclear Information System (INIS)

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

2007-01-01

The purpose of this study is to analyze the business administration of positron emission tomography (PET) facilities based on the survey of the price of PET cancer screening and cost analysis of PET examination. The questionnaire survey of the price of PET cancer screening was implemented for all PET facilities in Japan. Cost data of PET examination, including fixed costs and variable costs, were obtained from three different medical institutions. The marked price of the PET cancer screening was yen111,499 in average, and the most popular range of prices was between yen80,000 and yen90,000. Costs of PET per examination were accounted for yen110,675, yen79,158 and yen111,644 in facility A, B and C, respectively. The results suggested that facilities with two or more PET/CT per a cyclotron could only secure profits. In Japan, the boom in PET facility construction could not continue in accordance with increasing number of PET facilities. It would become more essential to analyze the appropriate distribution of PET facilities and the adequate amount of PET procedures from the perspective of efficient utilization of the PET equipments and supply of PET-related healthcare. (author)

PET Imaging Stability Measurements During Simultaneous Pulsing of Aggressive MR Sequences on the SIGNA PET/MR System.

Science.gov (United States)

Deller, Timothy W; Khalighi, Mohammad Mehdi; Jansen, Floris P; Glover, Gary H

2018-01-01

The recent introduction of simultaneous whole-body PET/MR scanners has enabled new research taking advantage of the complementary information obtainable with PET and MRI. One such application is kinetic modeling, which requires high levels of PET quantitative stability. To accomplish the required PET stability levels, the PET subsystem must be sufficiently isolated from the effects of MR activity. Performance measurements have previously been published, demonstrating sufficient PET stability in the presence of MR pulsing for typical clinical use; however, PET stability during radiofrequency (RF)-intensive and gradient-intensive sequences has not previously been evaluated for a clinical whole-body scanner. In this work, PET stability of the GE SIGNA PET/MR was examined during simultaneous scanning of aggressive MR pulse sequences. Methods: PET performance tests were acquired with MR idle and during simultaneous MR pulsing. Recent system improvements mitigating RF interference and gain variation were used. A fast recovery fast spin echo MR sequence was selected for high RF power, and an echo planar imaging sequence was selected for its high heat-inducing gradients. Measurements were performed to determine PET stability under varying MR conditions using the following metrics: sensitivity, scatter fraction, contrast recovery, uniformity, count rate performance, and image quantitation. A final PET quantitative stability assessment for simultaneous PET scanning during functional MRI studies was performed with a spiral in-and-out gradient echo sequence. Results: Quantitation stability of a 68 Ge flood phantom was demonstrated within 0.34%. Normalized sensitivity was stable during simultaneous scanning within 0.3%. Scatter fraction measured with a 68 Ge line source in the scatter phantom was stable within the range of 40.4%-40.6%. Contrast recovery and uniformity were comparable for PET images acquired simultaneously with multiple MR conditions. Peak noise equivalent count

New developments in PET detector technology

International Nuclear Information System (INIS)

Niu Lingxin; Zhao Shujun; Zhang Bin; Liu Haojia

2010-01-01

The researches on PET detector are always active and innovative area. The research direction of PET detector includes improving performances of scintillator-based detectors, investigating new detectors suitable for multi-modality imaging (e.g. PET/CT and PET/MRI), meeting requirements of TOF and DOI technologies and boosting the development of the technologies. In this paper, new developments in PET detector technology about scintillation crystal, photodetector and semiconductor detector is introduced. (authors)

PET in diagnosing exocrine pancreatic cancer; PET bei Tumoren des exokrinen Pankreas

Energy Technology Data Exchange (ETDEWEB)

Bares, R.; Besenfelder, H.; Dohmen, B.M. [Abt. Nuklearmedizin, Radiologische Klinik des Universitaetsklinikums Tuebingen (Germany)

2003-06-01

Despite dramatic improvements in diagnostic imaging (ultrasonography, in particular endoscopic ultrasound, CT, MRI) treatment results of pancreatic cancer are still poor. Due to the lack of early symptoms, most tumors are diagnosed at an advanced stage of disease which excludes curative surgical treatment. FDG-PET has been shown to be effective in detecting pancreatic cancer as well as differentiating benign from malignant pancreatic tumors. Results might be further improved by applying quantitative analyses, in particular kinetic modelling of FDG metabolism. Nevertheless false negative as well as false positive findings may occur. Small lesions (lymphnode or liver metastases < 1 cm) might be missed, furthermore hyperglycemia often present in patients with pancreatic disease might reduce tumor uptake and subsequently tumor detectability by PET. False positive findings were reported in active pancreatitis and some benign tumors. Although PET proved to be superior to CT or ERCP in detecting cancer, clinical relevance of PET is limited due to the absence of therapeutic consequences to be derived from PET. As a consequence PET should only be used in patients with equivocal findings of morphological imaging (CT, ERCP) who are potential candidates for surgical treatment. (orig.) [German] Trotz verbesserter diagnostischer Moeglichkeiten (endoskopischer Ultraschall, Spiral-CT, MRT) sind die Behandlungsergebnisse bei Tumoren des exokrinen Pankreas nach wie vor unbefriedigend. Aufgrund der spaet einsetzenden klinischen Symptomatik wird die Diagnose meist erst bei lokaler Inoperabilitaet gestellt. Die FDG-PET has sich sowohl im Nachweis von Pankreaskarzinomen als auch bei der Differenzialdiagnose pankreatischer Raumforderungen bewaehrt und den etablierten bildgebenden Verfahren (Ultraschall, CT) als ueberlegen erwiesen. Weitere Verbesserungen erscheinen durch absolute Quantifizierung der FDG-Kinetik moeglich. Dennoch koennen falsch negative wie auch falsch positive Ergebnisse

PET after use. From problem to opportunity; PET post-consumo. Da problema a opportunita'

Energy Technology Data Exchange (ETDEWEB)

Chiacchio, G.; Malinconico, M. [Consiglio Nazionale delle Ricerche, Arcofelice, NA (Italy). Istituto di Ricerca e Tecnologia delle Materie Plastiche; Santacesaria, E.; Di Sero, M. [Naples Univ. Federico 2. (Italy). Dipt. di Chimica

1999-04-01

Due to collection, separation and legislation problems, the only type of PET suitable for recycling, is, at moment, the polymer employed in liquid containers or, more precisely, PET from drink bottles. The paper refer to the most up-to-date strategies to overcomes typical problems occurring during physical recycling of PET (hydrolytic and thermal degradation). Among others, a recent procedure is cited, that utilizes p-hydroxybenzoic acid and titanium tetraisopropylate. As far as chemical recycling is concerned, alternative methodologies to PET glycolysis (normally employing ethyleneglycol to obtain monomers) using unsaturated diols to obtain polyesters suitable for production of thermosetting resins, are reported. Finally, chemical recycling of PET to produce alkyl-phthalates (well know plasticizers for thermoplastic polymers) is described. [Italian] L'unico tipo di PET che si presta concretamente ad essere impiegato in processi di riciclo e', attualmente, quello che deriva da contenitori per liquidi ed in particolare da bottiglie per bevande. Nel lavoro si fa riferimento alle strategie piu' recenti per ovviare ai problemi tipici del riciclo fisico del PET e ai metodidi riciclo chimico, mediante metodologie alternative di glicolisi del PET. Viene anche esposta una via alternativa di produzione di esteri alchil-ftalici (noti plastificanti per polimeri termoplastici).

MR-assisted PET Motion Correction for eurological Studies in an Integrated MR-PET Scanner

Science.gov (United States)

Catana, Ciprian; Benner, Thomas; van der Kouwe, Andre; Byars, Larry; Hamm, Michael; Chonde, Daniel B.; Michel, Christian J.; El Fakhri, Georges; Schmand, Matthias; Sorensen, A. Gregory

2011-01-01

Head motion is difficult to avoid in long PET studies, degrading the image quality and offsetting the benefit of using a high-resolution scanner. As a potential solution in an integrated MR-PET scanner, the simultaneously acquired MR data can be used for motion tracking. In this work, a novel data processing and rigid-body motion correction (MC) algorithm for the MR-compatible BrainPET prototype scanner is described and proof-of-principle phantom and human studies are presented. Methods To account for motion, the PET prompts and randoms coincidences as well as the sensitivity data are processed in the line or response (LOR) space according to the MR-derived motion estimates. After sinogram space rebinning, the corrected data are summed and the motion corrected PET volume is reconstructed from these sinograms and the attenuation and scatter sinograms in the reference position. The accuracy of the MC algorithm was first tested using a Hoffman phantom. Next, human volunteer studies were performed and motion estimates were obtained using two high temporal resolution MR-based motion tracking techniques. Results After accounting for the physical mismatch between the two scanners, perfectly co-registered MR and PET volumes are reproducibly obtained. The MR output gates inserted in to the PET list-mode allow the temporal correlation of the two data sets within 0.2 s. The Hoffman phantom volume reconstructed processing the PET data in the LOR space was similar to the one obtained processing the data using the standard methods and applying the MC in the image space, demonstrating the quantitative accuracy of the novel MC algorithm. In human volunteer studies, motion estimates were obtained from echo planar imaging and cloverleaf navigator sequences every 3 seconds and 20 ms, respectively. Substantially improved PET images with excellent delineation of specific brain structures were obtained after applying the MC using these MR-based estimates. Conclusion A novel MR-based MC

Diagnosis of non-osseous spinal metastatic disease: the role of PET/CT and PET/MRI.

Science.gov (United States)

Batouli, Ali; Braun, John; Singh, Kamal; Gholamrezanezhad, Ali; Casagranda, Bethany U; Alavi, Abass

2018-06-01

The spine is the third most common site for distant metastasis in cancer patients with approximately 70% of patients with metastatic cancer having spinal involvement. Positron emission tomography (PET), combined with computed tomography (CT) or magnetic resonance imaging (MRI), has been deeply integrated in modern clinical oncology as a pivotal component of the diagnostic work-up of patients with cancer. PET is able to diagnose several neoplastic processes before any detectable morphological changes can be identified by anatomic imaging modalities alone. In this review, we discuss the role of PET/CT and PET/MRI in the diagnostic management of non-osseous metastatic disease of the spinal canal. While sometimes subtle, recognizing such disease on FDG PET/CT and PET/MRI imaging done routinely in cancer patients can guide treatment strategies to potentially prevent irreversible neurological damage.

Novel PET sensors

International Nuclear Information System (INIS)

Cooper, C.R.

2001-03-01

This thesis describes the design, synthesis and evaluation of novel molecular sensors that utilize the phenomena of Photoinduced Electron Transfer (PET). PET design can be incorporated into molecules to allow them to selectively bind certain guest molecules. PET works by the modulation of electron potentials within a molecule. Binding events between a host and guest can, if designed suitably, change these potentials enough to cause a transfer of electronic charge within the molecular sensor. This event can be accurately and sensitively monitored by the use of ultra violet or fluorescence spectroscopy. A sensor molecule can be constructed by matching the guest to a suitable receptor site and incorporating this into a molecule containing a fluorophore with the correct electron potential characteristics. By using existing synthetic routes as well as exploiting new pathways these sensor molecules C n be constructed to contain a fluorophore separated from a guest receptor(s) by suitable spacers units. When put together these facets go to creating molecules that by design are sensitive and selective for certain guest molecules or functional groups. This methodology allows the synthetic chemist to rationally design and synthesise PET sensors, tailored to the needs of the guest. In this thesis the synthesis and evaluation of a novel PET sensors for D-glucosamine, disaccharides and fluoride is presented. It is believed that the novel sensors using the PET phenomenon presented in this thesis are a worthwhile extension of previous works undertaken by other groups around the world and shows new pathways to increasingly complex and sophisticated sensor molecular design. (author)

Study of oxygen scavenging PET-based films activated by water

Energy Technology Data Exchange (ETDEWEB)

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

2016-05-18

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

Study of oxygen scavenging PET-based films activated by water

Science.gov (United States)

Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana

2016-05-01

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

Philips Gemini TF64 PET/CT Acceptance Testing

International Nuclear Information System (INIS)

González Gonzalez, Joaquín J.; Calderón Marin, Carlos F.; Varela Corona, Consuelo; Machado Tejeda, Adalberto; González Correa, Héctor J.

2016-01-01

The Philips Gemini TF64 is the first PET/CT scanner installed in Cuba at the Institute of Oncology and Radiobiology in 2014. It is a third generation fully tridimensional whole body PET scanner with time-of-flight (TOF) technology combined with a 64-slice Brilliance CT scanner. The CT detector module contains 672x64 solid state detector, incorporating GOS scintillators, optical diodes and electronic signal channels arranged in 64 side by side arcs, with 672 detectors in each arc. There are sixteen 0.75 mm individual detector elements around the center and four 1.5 mm elements at each end, resulting in a 24 mm total detection length. The PET detector consists of 28 pixelar modules of a 23x44 array of 4x4x22 mm3 of LYSO crystals arranged in an Anger-logic detector design. The hardware coincidence-timing window for this scanner is set at 4 ns and delayed coincidence window technique is used to estimate the random coincidences in collected data. In this study the performance characteristics of PET/CT scanner were measured as part of the program tests of acceptance for clinical use.Methodology. The performance characteristics of CT scanner were evaluated by manufacturer protocol using Philips system performance phantom. Some additional geometrical tests were performed by the user. The intrinsic measurements of energy resolution as well as timing resolution, which define the TOF performance of PET scanner, were performed following the recommendations of manufacturer using 18 F. Spatial resolution, sensitivity, scatter fraction, counting rate performance, image quality and accuracy were measured according to the NEMA NU-2 2007 procedures. Additionally, to characterize the effect of TOF reconstruction on lesion contrast and noise, the standard NEMA torso phantom was reconstructed with and without TOF capability. The accuracy of PET/CT image registration was tested according to the manufacturer protocol using an image alignment calibration holder with 6 point sources of 22

Conspicuity of FDG-aid osseous lesions on PET/MRI versus PET/CT: A quantitative and visual analysis

Energy Technology Data Exchange (ETDEWEB)

Fraum, Tyler J.; Fowler, Kathryn J.; Mcconathy, Jonathan [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

2016-09-15

Because standard MRI-based attenuation correction (AC) does not account for the attenuation of photons by cortical bone, PET/MRI may have reduced sensitivity for FDG-avid focal bone lesions (FFBLs). This study evaluates whether MRI-based AC compromises detection of FFBLs, by comparing their conspicuity both quantitatively and qualitatively on PET/MRI versus PET/CT. One hundred ninety general oncology patients underwent whole-body PET/CT followed by whole-body PET/MRI, utilizing the same FDG dose. Thirteen patients with a total of 50 FFBLs were identified. Using automated contouring software, a volumetric contour was generated for each FFBL. Adjacent regions of normal background bone (BB) were selected manually. For each contour, SUV-max and SUV-mean were determined. Lesion-to-background SUV ratios served as quantitative metrics of conspicuity. Additionally, two blinded readers evaluated the relative conspicuity of FFBLs on PET images derived from MRI-based AC versus CT-based AC. Visibility of an anatomic correlate for FFBLs on the corresponding CT and MR images was also assessed. SUV-mean was lower on PET/MRI for both FFBLs (-6.5 %, p = 0.009) and BB (-20.5 %, p < 0.001). SUV-max was lower on PET/MRI for BB (-14.2 %, p = 0.002) but not for FFBLs (-6.2 %, p = 0.068). The ratio of FFBL SUV-mean to BB SUV-mean was higher for PET/MRI (+29.5 %, p < 0.001). Forty of 50 lesions (80 %) were visually deemed to be of equal or greater conspicuity on PET images derived from PET/MRI. Thirty-five of 50 FFBLs (70 %) had CT correlates, while 40/50 FFBLs (80 %) had a correlate on at least one MRI sequence. The mean interval from tracer administration to imaging was longer (p < 0.001) for PET/MRI (127 v. 62 min). Both FFBLs and BB had lower mean SUVs on PET/MRI than PET/CT. This finding was likely in part due to differences in the handling of cortical bone by MRI-based AC versus CT-based AC. Despite this systematic bias, FFBLs had greater conspicuity on PET

SmartPET: Applying HPGe and pulse shape analysis to small-animal PET

Energy Technology Data Exchange (ETDEWEB)

Cooper, R.J. [Department of Physics, University of Liverpool (United Kingdom)], E-mail: rjc@ns.ph.liv.ac.uk; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Grint, A.N.; Mather, A.R.; Nolan, P.J.; Scraggs, D.P.; Turk, G. [Department of Physics, University of Liverpool (United Kingdom); Hall, C.J.; Lazarus, I. [CCLRC Daresbury Laboratory, Warrington, Cheshire (United Kingdom); Berry, A.; Beveridge, T.; Gillam, J.; Lewis, R.A. [School of Physics and Materials Engineering, Monash University, Melbourne (Australia)

2007-08-21

The SmartPET project is the development of a prototype small-animal imaging system based on the use of Hyperpure Germanium (HPGe) detectors. The use of digital electronics and application of Pulse Shape Analysis (PSA) techniques provide fine spatial resolution, while the excellent intrinsic energy resolution of HPGe detectors makes the system ideal for multi-nuclide imaging. As a result, the SmartPET system has the potential to function as a dual modality imager, operating as a dual-head Positron Emission Tomography (PET) camera or in a Compton Camera configuration for Single Photon Emission Computed Tomography (SPECT) imaging. In this paper, we discuss how the use of simple PSA techniques greatly improves the position sensitivity of the detector yielding improved spatial resolution in reconstructed images. The PSA methods presented have been validated by comparison to data from high-precision scanning of the detectors. Results from this analysis are presented along with initial images from the SmartPET system, which demonstrates the impact of these techniques on PET images.

Usage of Recycled Pet

Directory of Open Access Journals (Sweden)

A. Ebru Tayyar

2010-01-01

Full Text Available The increasing industrialization, urbanization and the technological development have caused to increase depletion of the natural resources and environmental pollution's problem. Especially, for the countries which have not enough space recycling of the waste eliminating waste on regular basis or decreasing the amount and volume of waste have provided the important advantages. There are lots of studies and projects to develop both protect resources and prevent environmental pollution. PET bottles are commonly used in beverage industry and can be reused after physical and chemical recycling processes. Usage areas of recycled PET have been developed rapidly. Although recycled PET is used in plastic industry, composite industry also provides usage alternatives of recycled PET. Textile is a suitable sector for recycling of some plastics made of polymers too. In this study, the recycling technologies and applications of waste PET bottles have been investigated and scientific works in this area have been summarized.

A compact cost-effective beamline for a PET Cyclotron

International Nuclear Information System (INIS)

Dehnel, M.P.; Jackle, P.; Roeder, M.; Stewart, T.; Theroux, J.; Brasile, J.P.; Sirot, P.; Buckley, K.R.; Bedue, M.

2007-01-01

Most commercial PET Cyclotrons have targets mounted on or near the main cyclotron vacuum chamber. There is often little or no system capability for centering or focusing the extracted beam on target to achieve maximum production. This paper describes the ion-optics, design and development of a compact cost-effective beamline comprised of low activation and radiation resistant materials. The beamline, complete with suitable diagnostic devices, permits the extracted proton beam to be centered (X-Y steering magnet), and focused (quadrupole doublet) on target eliminating unnecessary beamspill and ensuring high production

The effect, identification and correction of misalignment between PET transmission and emission scans on brain PET imaging

International Nuclear Information System (INIS)

Zhang Xiangsong; He Zuoxiang; Tang Anwu; Qiao Suixian

2004-01-01

Objectives: To study the effect of misalignment between PET transmission and emission scans of brain on brain PET imaging, and the Methods to identify and correct it. Methods: 18F-FDG PET imaging was performed on 8 volunteers. The emission images were reconstructed with attenuation correction after some translations and rotations in the x-axis and transverse plane were given, 1 mm and 1 degree each step, respectively. The 3-D volume fusion of PET emission and transmission scans was used to identify the suspected misalignment on 10 18F-FDG PET brain imaging. Three Methods were used to correct the misalignment. First, to quantitate the amount of the misalignment by 3-D volume registration of PET emission and transmission scans, the emission images were reconstructed with corrected translations and rotations in x-direction and transverse plane. Second, the emission images were reconstructed with mathematic calculation of brain attenuation. Third, 18F-FDG PET brain imaging was redone with careful application of laser alignment. Results: The translations greater than 3 mm in x-direction and the rotations greater than 8 degrees in transverse plane could lead to visible artifacts, which were presented with decreasing radioactivity uptake in the cortex of half cerebrum and in the frontal cortex at the side in the translating or rotating direction, respectively. The 3-D volume fusion of PET emission and transmission scans could identify and quantitate the amount of misalignment between PET emission and transmission scans of brain. The PET emission images reconstructed with corrected misalignment and mathematic calculation of brain attenuation were consistent with redone PET brain imaging. Conclusions: The misalignment between PET transmission and emission scans of brain can lead to visible artifacts. The 3-D volume fusion of PET emission and transmission scans can identify and quantitate the amount of the misalignment. The visible artifacts caused by the misalignment can be

FDG PET and PET-CT for the detection of bone metastases in patients with head and neck cancer. A meta-analysis

International Nuclear Information System (INIS)

Yi, Xuelin; Zhang, Hongting; Liu, Shixi; Fan, Min; Liu, Yilin

2013-01-01

We performed a meta-analysis to evaluate 18FDG PET/PET-CT for the detection of bone metastases in patients with head and neck cancer. We calculated sensitivities, specificities, likelihood ratios, and constructed summary receiver operating characteristic curves for PET and PET-CT, respectively. We also compared the performance of PET/PET-CT with that of bone scintigraphy by analysing studies that had also used bone scintigraphy on the same patients. Across 9 PET studies (1621 patients) and 10 PET-CT studies (1291 patients), sensitivity and specificity of PET were 0.81 and 0.99, and of PET-CT were 0.89 and 0.99, respectively. In 5 comparative studies (1184 patients), sensitivity and specificity of PET/PET-CT were 0.85 and 0.98, and of bone scintigraphy were 0.55 and 0.98, respectively. 18FDG PET and PET-CT have high sensitivity and accuracy for the detection of bone metastasis in patients with head and neck cancer.

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

OpenAIRE

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 ...

Multi-technique hybrid imaging in PET/CT and PET/MR: what does the future hold?

International Nuclear Information System (INIS)

Galiza Barbosa, F. de; Delso, G.; Voert, E.E.G.W. ter; Huellner, M.W.; Herrmann, K.; Veit-Haibach, P.

2016-01-01

Integrated positron-emission tomography and computed tomography (PET/CT) is one of the most important imaging techniques to have emerged in oncological practice in the last decade. Hybrid imaging, in general, remains a rapidly growing field, not only in developing countries, but also in western industrialised healthcare systems. A great deal of technological development and research is focused on improving hybrid imaging technology further and introducing new techniques, e.g., integrated PET and magnetic resonance imaging (PET/MRI). Additionally, there are several new PET tracers on the horizon, which have the potential to broaden clinical applications in hybrid imaging for diagnosis as well as therapy. This article aims to highlight some of the major technical and clinical advances that are currently taking place in PET/CT and PET/MRI that will potentially maintain the position of hybrid techniques at the forefront of medical imaging technologies.

Thoracic staging in lung cancer: prospective comparison of 18F-FDG PET/MR imaging and 18F-FDG PET/CT.

Science.gov (United States)

Heusch, Philipp; Buchbender, Christian; Köhler, Jens; Nensa, Felix; Gauler, Thomas; Gomez, Benedikt; Reis, Henning; Stamatis, Georgios; Kühl, Hilmar; Hartung, Verena; Heusner, Till A

2014-03-01

Therapeutic decisions in non-small cell lung cancer (NSCLC) patients depend on the tumor stage. PET/CT with (18)F-FDG is widely accepted as the diagnostic standard of care. The purpose of this study was to compare a dedicated pulmonary (18)F-FDG PET/MR imaging protocol with (18)F-FDG PET/CT for primary and locoregional lymph node staging in NSCLC patients using histopathology as the reference. Twenty-two patients (12 men, 10 women; mean age ± SD, 65.1 ± 9.1 y) with histopathologically confirmed NSCLC underwent (18)F-FDG PET/CT, followed by (18)F-FDG PET/MR imaging, including a dedicated pulmonary MR imaging protocol. T and N staging according to the seventh edition of the American Joint Committee on Cancer staging manual was performed by 2 readers in separate sessions for (18)F-FDG PET/CT and PET/MR imaging, respectively. Results from histopathology were used as the standard of reference. The mean and maximum standardized uptake value (SUV(mean) and SUV(max), respectively) and maximum diameter of the primary tumor was measured and compared in (18)F-FDG PET/CT and PET/MR imaging. PET/MR imaging and (18)F-FDG PET/CT agreed on T stages in 16 of 16 of patients (100%). All patients were correctly staged by (18)F-FDG PET/CT and PET/MR (100%), compared with histopathology. There was no statistically significant difference between (18)F-FDG PET/CT and (18)F-FDG PET/MR imaging for lymph node metastases detection (P = 0.48). For definition of thoracic N stages, PET/MR imaging and (18)F-FDG PET/CT were concordant in 20 of 22 patients (91%). PET/MR imaging determined the N stage correctly in 20 of 22 patients (91%). (18)F-FDG PET/CT determined the N stage correctly in 18 of 22 patients (82%). The mean differences for SUV(mean) and SUV(max) of NSCLC in (18)F-FDG PET/MR imaging and (18)F-FDG PET/CT were 0.21 and -5.06. These differences were not statistically significant (P > 0.05). The SUV(mean) and SUV(max) measurements derived from (18)F-FDG PET/CT and (18)F-FDG PET

PET imaging in multiple sclerosis

NARCIS (Netherlands)

Faria, Daniele de Paula; Copray, Sjef; Buchpiguel, Carlos; Dierckx, Rudi; de Vries, Erik

Positron emission tomography (PET) is a non-invasive technique for quantitative imaging of biochemical and physiological processes in animals and humans. PET uses probes labeled with a radioactive isotope, called PET tracers, which can bind to or be converted by a specific biological target and thus

Brain PET and functional MRI: why simultaneously using hybrid PET/MR systems?

Science.gov (United States)

Cecchin, Diego; Palombit, Alessandro; Castellaro, Marco; Silvestri, Erica; Bui, Franco; Barthel, Henryk; Sabri, Osama; Corbetta, Maurizio; Bertoldo, Alessandra

2017-12-01

In the last 20 years growing attention has been devoted to multimodal imaging. The recent literature is rich of clinical and research studies that have been performed using different imaging modalities on both separate and integrated positron emission tomography (PET) and magnetic resonance (MR) scanners. However, today, hybrid PET/MR systems measure signals related to brain structure, metabolism, neurochemistry, perfusion, and neuronal activity simultaneously, i.e. in the same physiological conditions. A frequently raised question at meeting and symposia is: "Do we really need a hybrid PET/MR system? Are there any advantages over acquiring sequential and separate PET and MR scans?" The present paper is an attempt to answer these questions specifically in relation to PET combined with functional magnetic resonance imaging (fMRI) and arterial spin labeling. We searched (last update: June 2017) the databases PubMed, PMC, Google Scholar and Medline. We also included additional studies if they were cited in the selected articles. No language restriction was applied to the search, but the reviewed articles were all in English. Among all the retrieved articles, we selected only those performed using a hybrid PET/MR system. We found a total of 17 papers that were selected and discussed in three main groups according to the main radiopharmaceutical used: 18F-fluorodeoxyglucose (18F-FDG) (N.=8), 15O-water (15O-H2O) (N.=3) and neuroreceptors (N.=6). Concerning studies using 18F-FDG, simultaneous PET/fMRI revealed that global aspects of functional organization (e.g. graph properties of functional connections) are partially associated with energy consumption. There are remarkable spatial and functional similarities across modalities, but also discrepant findings. More work is needed on this point. There are only a handful of papers comparing blood flow measurements with PET 15O-H2O and MR arterial spin label (ASL) measures, and they show significant regional CBF differences

Are Pets in the Bedroom a Problem?

Science.gov (United States)

Krahn, Lois E; Tovar, M Diane; Miller, Bernie

2015-12-01

The presence of pets in the bedroom can alter the sleep environment in ways that could affect sleep. Data were collected by questionnaire and interview from 150 consecutive patients seen at the Center for Sleep Medicine, Mayo Clinic in Arizona. Seventy-four people (49%) reported having pets, with 31 (41% of pet owners) having multiple pets. More than half of pet owners (56%) allowed their pets to sleep in the bedroom. Fifteen pet owners (20%) described their pets as disruptive, whereas 31 (41%) perceived their pets as unobtrusive or even beneficial to sleep. Health care professionals working with patients with sleep concerns should inquire about the presence of companion animals in the sleep environment to help them find solutions and optimize their sleep. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

PET/TAC in Oncology; PET/TAC en Oncologia

Energy Technology Data Exchange (ETDEWEB)

Jimenez V, A M [Especialista en Medicina Nuclear, Profa. Depto. Radiologia de la Facultad de Medicina, Universidad Complutense de Madrid, Madrid (Spain)

2007-07-01

From this presentation of PET-TAC in oncology the following advantages on the conventional PET are obtained: 1. More short study and stadium in one session. 2. It adds the information of both techniques. 3. Better localization of leisure: affected organ, stadium change (neck, mediastinum, abdomen). 4. Reduction of false positive (muscle, brown fat, atelectasis, pneumonias, intestine, urinary vials, etc.). 5. Reduction of negative false. 6. Reduction of not conclusive. 7. More understandable for other specialists. 8. Biopsies guide. 9. Planning radiotherapy.

Simultaneous PET/MR imaging in a human brain PET/MR system in 50 patients—Current state of image quality

International Nuclear Information System (INIS)

Schwenzer, N.F.; Stegger, L.; Bisdas, S.; Schraml, C.; Kolb, A.; Boss, A.; Müller, M.

2012-01-01

Objectives: The present work illustrates the current state of image quality and diagnostic accuracy in a new hybrid BrainPET/MR. Materials and methods: 50 patients with intracranial masses, head and upper neck tumors or neurodegenerative diseases were examined with a hybrid BrainPET/MR consisting of a conventional 3T MR system and an MR-compatible PET insert. Directly before PET/MR, all patients underwent a PET/CT examination with either [ 18 F]-FDG, [ 11 C]-methionine or [ 68 Ga]-DOTATOC. In addition to anatomical MR scans, functional sequences were performed including diffusion tensor imaging (DTI), arterial spin labeling (ASL) and proton-spectroscopy. Image quality score of MR imaging was evaluated using a 4-point-scale. PET data quality was assessed by evaluating FDG-uptake and tumor delineation with [ 11 C]-methionine and [ 68 Ga]-DOTATOC. FDG uptake quantification accuracy was evaluated by means of ROI analysis (right and left frontal and temporo-occipital lobes). The asymmetry indices and ratios between frontal and occipital ROIs were compared. Results: In 45/50 patients, PET/MR examination was successful. Visual analysis revealed a diagnostic image quality of anatomical MR imaging (mean quality score T2 FSE: 1.27 ± 0.54; FLAIR: 1.38 ± 0.61). ASL and proton-spectroscopy was possible in all cases. In DTI, dental artifacts lead to one non-diagnostic dataset (mean quality score DTI: 1.32 ± 0.69; ASL: 1.10 ± 0.31). PET datasets of PET/MR and PET/CT offered comparable tumor delineation with [ 11 C]-methionine; additional lesions were found in 2/8 [ 68 Ga]-DOTATOC-PET in the PET/MR. Mean asymmetry index revealed a high accordance between PET/MR and PET/CT (1.5 ± 2.2% vs. 0.9 ± 3.6%; mean ratio (frontal/parieto-occipital) 0.93 ± 0.08 vs. 0.96 ± 0.05), respectively. Conclusions: The hybrid BrainPET/MR allows for molecular, anatomical and functional imaging with uncompromised MR image quality and a high accordance of PET results between PET/MR and PET

Simultaneous PET/MR imaging in a human brain PET/MR system in 50 patients-Current state of image quality

Energy Technology Data Exchange (ETDEWEB)

Schwenzer, N.F., E-mail: nina.schwenzer@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Stegger, L., E-mail: stegger@gmx.net [Department of Nuclear Medicine and European Institute for Molecular Imaging, University of Muenster, Muenster (Germany); Bisdas, S., E-mail: sbisdas@gmail.com [Department of Diagnostic and Interventional Neuroradiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Schraml, C., E-mail: christina.schraml@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Kolb, A., E-mail: armin.kolb@med.uni-tuebingen.de [Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Preclinical Imaging and Radiopharmacy, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Boss, A., E-mail: Andreas.Boss@usz.ch [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Institute of Diagnostic and Interventional Radiology, University Hospital Zuerich, Zuerich (Switzerland); Mueller, M., E-mail: mark.mueller@med.uni-tuebingen.de [Department of Nuclear Medicine, Eberhard-Karls University Tuebingen, Tuebingen (Germany); and others

2012-11-15

Objectives: The present work illustrates the current state of image quality and diagnostic accuracy in a new hybrid BrainPET/MR. Materials and methods: 50 patients with intracranial masses, head and upper neck tumors or neurodegenerative diseases were examined with a hybrid BrainPET/MR consisting of a conventional 3T MR system and an MR-compatible PET insert. Directly before PET/MR, all patients underwent a PET/CT examination with either [{sup 18}F]-FDG, [{sup 11}C]-methionine or [{sup 68}Ga]-DOTATOC. In addition to anatomical MR scans, functional sequences were performed including diffusion tensor imaging (DTI), arterial spin labeling (ASL) and proton-spectroscopy. Image quality score of MR imaging was evaluated using a 4-point-scale. PET data quality was assessed by evaluating FDG-uptake and tumor delineation with [{sup 11}C]-methionine and [{sup 68}Ga]-DOTATOC. FDG uptake quantification accuracy was evaluated by means of ROI analysis (right and left frontal and temporo-occipital lobes). The asymmetry indices and ratios between frontal and occipital ROIs were compared. Results: In 45/50 patients, PET/MR examination was successful. Visual analysis revealed a diagnostic image quality of anatomical MR imaging (mean quality score T2 FSE: 1.27 {+-} 0.54; FLAIR: 1.38 {+-} 0.61). ASL and proton-spectroscopy was possible in all cases. In DTI, dental artifacts lead to one non-diagnostic dataset (mean quality score DTI: 1.32 {+-} 0.69; ASL: 1.10 {+-} 0.31). PET datasets of PET/MR and PET/CT offered comparable tumor delineation with [{sup 11}C]-methionine; additional lesions were found in 2/8 [{sup 68}Ga]-DOTATOC-PET in the PET/MR. Mean asymmetry index revealed a high accordance between PET/MR and PET/CT (1.5 {+-} 2.2% vs. 0.9 {+-} 3.6%; mean ratio (frontal/parieto-occipital) 0.93 {+-} 0.08 vs. 0.96 {+-} 0.05), respectively. Conclusions: The hybrid BrainPET/MR allows for molecular, anatomical and functional imaging with uncompromised MR image quality and a high accordance

FDG-PET, PET/CT and conventional nuclear medicine procedures in the evaluation of lung cancer. A systematic review

International Nuclear Information System (INIS)

Hellwig, Dirk; Kirsch, C.M.; Baum, R.P.

2009-01-01

Aim: Currently, the German and Austrian S3 guidelines on the evaluation and treatment of lung cancer are about to be published whereas the American Colleague of Chest Physicians (ACCP) guidelines were already presented in 2007. An important part of the diagnostic workup of lung cancer will be the evaluation of indeterminate lung lesions and the mediastinal and extrathoracic staging using FDG-PET or PET/CT. The results from the literature on FDG-PET and PET/CT as well as on conventional nuclear medicine staging procedures and the clinical implications are presented. Methods: The literature data was amassed in analogy to the metaanalyses drawn for the current ACCP guidelines. In addition, relevant more recent publications were also considered. To answer the important question for the extent of pathological confirmation needed, the residual risk of mediastinal metastases was calculated for certain constellations of FDG-PET and CT findings. Suggested recommendations were characterized with the level of evidence. Results: FDG-PET (PET/CT) allows the differentiation of indeterminate lung lesions with high accuracy. FDG-PET (PET/CT) is the most accurate non-invasive procedure to assess the mediastinal nodal stage, for non-small cell as well as for small cell lung cancer. It is justified to omit invasive evaluation of enlarged but FDG-PET negative lymph nodes under certain circumstances. Unexpected extrathoracic metastases detected by FDG-PET imply important changes in therapeutic management. Conclusion: The upcoming S3 guideline on lung cancer will recommend FDG-PET in several indications due to its clinical efficacy well proven by data from literature (high level of evidence). The selected use of conventional nuclear medicine procedures remains beyond doubt. FDG-PET (PET/CT) belongs to the standard of care in lung cancer

FDG-PET, PET/CT and conventional nuclear medicine procedures in the evaluation of lung cancer. A systematic review

Energy Technology Data Exchange (ETDEWEB)

Hellwig, Dirk; Kirsch, C.M. [Saarland Univ. Medical Center, Homburg (Germany). Dept. of Nuclear Medicine; Baum, R.P. [Zentralklinik Bad Berka (Germany). Dept. of Nuclear Medicine / PET Center

2009-07-01

Aim: Currently, the German and Austrian S3 guidelines on the evaluation and treatment of lung cancer are about to be published whereas the American Colleague of Chest Physicians (ACCP) guidelines were already presented in 2007. An important part of the diagnostic workup of lung cancer will be the evaluation of indeterminate lung lesions and the mediastinal and extrathoracic staging using FDG-PET or PET/CT. The results from the literature on FDG-PET and PET/CT as well as on conventional nuclear medicine staging procedures and the clinical implications are presented. Methods: The literature data was amassed in analogy to the metaanalyses drawn for the current ACCP guidelines. In addition, relevant more recent publications were also considered. To answer the important question for the extent of pathological confirmation needed, the residual risk of mediastinal metastases was calculated for certain constellations of FDG-PET and CT findings. Suggested recommendations were characterized with the level of evidence. Results: FDG-PET (PET/CT) allows the differentiation of indeterminate lung lesions with high accuracy. FDG-PET (PET/CT) is the most accurate non-invasive procedure to assess the mediastinal nodal stage, for non-small cell as well as for small cell lung cancer. It is justified to omit invasive evaluation of enlarged but FDG-PET negative lymph nodes under certain circumstances. Unexpected extrathoracic metastases detected by FDG-PET imply important changes in therapeutic management. Conclusion: The upcoming S3 guideline on lung cancer will recommend FDG-PET in several indications due to its clinical efficacy well proven by data from literature (high level of evidence). The selected use of conventional nuclear medicine procedures remains beyond doubt. FDG-PET (PET/CT) belongs to the standard of care in lung cancer.

Analisis Gameplay Game Genre Virtual Pet

Directory of Open Access Journals (Sweden)

Abi Senoprabowo

2015-02-01

Full Text Available Game adalah struktur interaktif yang membuat pemain berjuang menuju sebuah tujuan. Game dapat memberikan emosi dan mood, menghubungkan dengan orang latihan, sarana latihan, serta dapat memberikan edukasi. Salah satu game yang berkembang saat ini adalah game bergenre Virtual pet. Game virtual pet merupakan game simulasi memelihara sesuatu. Virtual pet memiliki gameplay yang menarik dan menyenangkan yang membuat pemain seolah-olah benar-benar memiliki binatang peliharaan mereka sendiri. Virtual pet dianggap oleh sebagian besar penggunanya dapat memberikan kegembiraan serta rasa kasih sayang karena tingkat interaksinya yang baik. Banyak pengembang game pemula yang mengembangkan genre ini sebagai game yang mereka buat karena kemudahaan dan tingkat penggunanya yang banyak. Akan tetapi banyak dari pengembang game pemula tidak memperhatikan tingkat keberlanjutan game virtual pet yang mereka buat sehingga membuat pemain cepat bosan. Pada penelitian ini, analisis game bergenre virtual pet yang sudah sukses dibuat seperti Zombigotchi, Tamagotchi Unicorn, dan Bird Land, diharapkan dapat membantu para pengembang game pemula agar mengetahui cara merancang dan mengembangkan game virtual pet dengan baik. Kata Kunci: game, gameplay, virtual pet

PET/CT与PET/MR在诊断宫颈癌原发灶及评价盆腔淋巴结转移的比较研究%Value of PET/CT and PET/MR in diagnosing primary cervical cancer and evaluating pelvic lymph node metastasis: Comparative study

Institute of Scientific and Technical Information of China (English)

尚靳; 孙洪赞; 辛军; 郭启勇

2018-01-01

目的 比较PET/CT和PET/MR在诊断宫颈癌原发灶及盆腔淋巴结转移中的应用价值.方法 对40例宫颈癌患者于治疗前分别行PET/CT和PET/MR检查并进行评价.采用Kappa一致性检验及配对x2检验分别评价PET/CT和PET/MR与金标准的诊断一致性及差异.采用ROC曲线分析两者对盆腔转移淋巴结的诊断效能,采用秩和检验分析两者评价转移淋巴结的可见性及诊断自信度的差异.结果 PET/MR分期与金标准的诊断一致性显著高于PET/CT,二者对宫颈癌分期诊断的差异有统计学意义(x2=10.286,P=0.002);PET/CT和PET/MR诊断转移淋巴结的曲线下面积差异无统计学意义(Z=0.83,P＞0.05);二者对转移淋巴结的可见性评分差异无统计学意义(P=0.157),诊断自信度评分差异有统计学意义(P=0.014).结论 PET/CT和PET/MR对检出宫颈癌原发灶均有较高的诊断价值,但PET/MR对宫颈癌分期及判定淋巴结转移有更大的诊断优势,PET/MR有望在综合评价宫颈恶性病变进展中成为替代PET/CT的一种新技术.%Objective To compare the application value between PET/CT and PET/MR in diagnosing primary cervical cancer and pelvic lymph node metastasis.Methods Forty cases of cervical cancer were prospectively enrolled.PET/CT and PET/MR examinations were performed before treatment.All imaging data were evaluated by two experienced radiologists.The diagnostic consistency and difference of PET/CT and PET/MR were evaluated with Cohen's Kappa and paired Chi-square test.ROC curve was adopted to observe the value in diagnosing pelvic lymph node metastasis of cervical cancer.The lesions' visibility and diagnostic confidence of metastatic lymph nodes on PET/CT and PET/MR images were compared with Wilcoxon signed ranks test.Results Compared with the gold standard,the diagnostic consistency of PET/MR staging was much higher than that of PET/CT (x2 =10.286,P=0.002).The area under ROC curve of PET/CT and PET/MR on lymph node metastasis

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

Science.gov (United States)

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

2017-07-01

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

PET/CT with intravenous contrast can be used for PET attenuation correction in cancer patients

DEFF Research Database (Denmark)

Berthelsen, A K; Holm, S; Loft, A

2005-01-01

PURPOSE: If the CT scan of a combined PET/CT study is performed as a full diagnostic quality CT scan including intravenous (IV) contrast agent, the quality of the joint PET/CT procedure is improved and a separate diagnostic CT scan can be avoided. CT with IV contrast can be used for PET attenuation...... correction, but this may result in a bias in the attenuation factors. The clinical significance of this bias has not been established. Our aim was to perform a prospective clinical study where each patient had CT performed with and without IV contrast agent to establish whether PET/CT with IV contrast can...... scans without, and then with contrast agent, followed by an 18F-fluorodeoxyglucose whole-body PET scan. The CT examinations were performed with identical parameters on a GE Discovery LS scanner. The PET data were reconstructed with attenuation correction based on the two CT data sets. A global...

Present and future aspects of PET examinations

International Nuclear Information System (INIS)

Inoue, Tomio

2003-01-01

The PET examination gives the body distribution image of a compound labeled with the positron emitter manufactured by cyclotron. Recently, PET with F18-deoxyglucose (FDG) attracts considerable attention because the imaging is particularly useful for cancer detection. Since the technique was authorized by the United States (US) official health insurance in 1998, the number of the examination is increasing, which is also under similar situation in Japan due to the latest partial authorization for some malignant tumors. In Japan, about 30,000 examinations per year are carried out, half of which, in private hospitals. Their purpose is increasingly for cancer detection. For future PET examination, awaited are improvement of PET camera and development of a novel imaging agent. PET/CT imaging is for the former and F18-α-methyltyrosine, for the latter. Miniaturization of cyclotron, FDG delivery system, improved FDG synthetic method, popularization of PET/CT, development of PET camera for health examination, clinical trial of a novel imaging agent, and spread of PET health examination and operation of PET Center, are expected for future progress of PET technique. (N.I.)

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Development of PET in Latin America. Experience of the first PET-Cyclotron Center

International Nuclear Information System (INIS)

Tutor, C.A.; Frias, L.

2002-01-01

Aim: Describe the experience of the first PET-Cyclotron Center in Latin America. Demonstrate the viability of running a PET Center in Argentina despite the economic crisis. Materials and Methods: For this study, we used a UGM/GE Quest 250 PET scan, a RDS 112 cyclotron and a Radiosynthesis Laboratory installed at the (FUESMEN) Nuclear Medicine School Foundation, located in Mendoza City, in the middle-west of Argentina. From January 1999 to March 2002, 741 studies were obtained, 731 were 18 FluorDeoxyGlucose-PET studies and 10 phantoms for calibration purposes. We used acquisition and imaging processing standard protocols, as well as research protocols designed according to the pathology under investigation. To better correlate anatomical and functional images, we used fusion techniques with (CT) Computed Tomography in some (WB) whole-body PET scans. Results: A total of 731 patients were retrospectively analyzed and classified according to statistics variables such as: 1-sex: 317 women and 414 men, 2-type of scan: 439 WB cases, 267 brain studies and 25 cardiac. From this data we divided them as PET indications and resulted in 17 cases as healthy volunteers, 422 oncological cases, 267 neurological studies and 25 cardiac for myocardial viability. According to the origin they were classified as patients coming from Mendoza 544, Buenos Aires 112, other argentine provinces 60 and foreign (Chile, Brazil and Uruguay) 15 cases. In terms of billing, 181 studies were done free of charge, 95 under research protocols were also done free of charge and 451 were charged. Conclusion: Not only the economical and political factors play an important role limiting the advances of PET Imaging in Latin America, but also the lack of a neighboring cyclotron that circumscribe many hospitals to have access to the radiopharmaceutical agent. FUESMEN was established in 1991 by three governmental entities: the (CONEA) National Commission of Atomic Energy, the (UNC) National University of Cuyo and

Current status and future perspective of PET

International Nuclear Information System (INIS)

Lee, Myung Chul

2002-01-01

Positron Emission Tomography (PET) is a nuclear medicine imaging modality that consists of systemic administration to a subject of a radiopharmaceutical labeled with a positron-emitting radionuclide. Following administration, its distribution in the organ or structure under study can be assessed as a function of time and space by (1) detecting the annihilation radiation resulting from the interaction of the positrons with matter, and (2) reconstructing the distribution of the radioactivity from a series of that used in computed tomography (CT). The nuclides most generally exhibit chemical properties that render them particularly desirable in physiological studies. The radionuclides most widely used in PET are F-18, C-11, O-15 and N-13. Regarding to the number of the current PET Centers worldwide (based on ICP data), more than 300 PET Centers were in operation in 2000. The use of PET technology grew rapidly compared to that in 1992 and 1996, particularly in the USA, which demonstrates a three-fold rise in PET installations. In 2001, 194 PET Centers were operating in the USA. In 1994, two clinical and research-oriented PET Centers at Seoul National University Hospital and Samsung Medical Center, was established as the first dedicated PET and Cyclotron machines in Korea, followed by two more PET facilities at the Korea Cancer Center Hospital, Ajou Medical Center, Yonsei University Medical Center, National Cancer Center and established their PET Center. Catholic Medical School and Pusan National University Hospital have finalized a plan to install PET machine in 2002, which results in total of nine PET Centers in Korea. Considering annual trends of PET application in four major PET centers in Korea in Asan Medical Center recent six years (from 1995 to 2000), a total of 11,564 patients have been studied every year and the number of PET studies has shown steep growth year upon year. We had, 1,020 PET patients in 1995. This number increased to 1,196, 1,756, 2,379, 3

Exploring the differences between pet and non-pet owners: Implications for human-animal interaction research and policy.

Directory of Open Access Journals (Sweden)

Jessica Saunders

Full Text Available There is conflicting evidence about whether living with pets results in better mental and physical health outcomes, with the majority of the empirical research evidence being inconclusive due to methodological limitations. We briefly review the research evidence, including the hypothesized mechanisms through which pet ownership may influence health outcomes. This study examines how pet and non-pet owners differ across a variety of socio-demographic and health measures, which has implications for the proper interpretation of a large number of correlational studies that attempt to draw causal attributions. We use a large, population-based survey from California administered in 2003 (n = 42,044 and find that pet owners and non-pet owners differ across many traits, including gender, age, race/ethnicity, living arrangements, and income. We include a discussion about how the factors associated with the selection into the pet ownership group are related to a range of mental and physical health outcomes. Finally, we provide guidance on how to properly model the effects of pet ownership on health to accurately estimate this relationship in the general population.

Development of compact DOI-measurable PET detectors for simultaneous PET/MR Imaging

Energy Technology Data Exchange (ETDEWEB)

Shao, Yiping; Sun, Xishan [University of Texas MD Anderson Cancer Center (United States); Lou, Kai [Rice University (United States)

2015-05-18

It is critically needed yet challenging to develop compact PET detectors with high sensitivity and uniform, high imaging resolution for improving the performance of simultaneous PET/MR imaging, particularly for an integrated/inserted small-bore system. Using the latest “edge-less” SiPM arrays for DOI measurement using the design of dual-ended-scintillator readout, we developed several compact PET detectors suited for PET/MR imaging. Each detector consists of one LYSO array with each end coupled to a SiPM array. Multiple detectors can be seamlessly tiled together along all sides to form a large detector panel. Detectors with 1.5x1.5 and 2.0x2.0 mm crystals at 20 or 30 mm lengths were studied. Readout of individual SiPM or capacitor-based signal multiplexing was used to transfer 3D interaction position-coded analog signals through flexible-print-circuit cables to dedicated ASIC frontend electronics to output digital timing pulses that encode interaction information. These digital pulses can be transferred to, through standard LVDS cables, and decoded by a FPGA-based data acquisition positioned outside the MRI scanner for coincidence event selection. Initial detector performance measurement shows excellent crystal identification even with 30 mm long crystals, ~18% and 2.8 ns energy and timing resolutions, and around 2-3 mm DOI resolution. A large size detector panel can be scaled up with these modular detectors and different PET systems can be flexibly configured with the scalable readout electronics and data acquisition, providing an important design advantage for different system and application requirements. It is expected that standard shielding of detectors, electronics and signal transfer lines can be applied for simultaneous PET/MR imaging applications, with desired DOI measurement capability to enhance the PET performance and image quality.

Development of compact DOI-measurable PET detectors for simultaneous PET/MR Imaging

International Nuclear Information System (INIS)

Shao, Yiping; Sun, Xishan; Lou, Kai

2015-01-01

It is critically needed yet challenging to develop compact PET detectors with high sensitivity and uniform, high imaging resolution for improving the performance of simultaneous PET/MR imaging, particularly for an integrated/inserted small-bore system. Using the latest “edge-less” SiPM arrays for DOI measurement using the design of dual-ended-scintillator readout, we developed several compact PET detectors suited for PET/MR imaging. Each detector consists of one LYSO array with each end coupled to a SiPM array. Multiple detectors can be seamlessly tiled together along all sides to form a large detector panel. Detectors with 1.5x1.5 and 2.0x2.0 mm crystals at 20 or 30 mm lengths were studied. Readout of individual SiPM or capacitor-based signal multiplexing was used to transfer 3D interaction position-coded analog signals through flexible-print-circuit cables to dedicated ASIC frontend electronics to output digital timing pulses that encode interaction information. These digital pulses can be transferred to, through standard LVDS cables, and decoded by a FPGA-based data acquisition positioned outside the MRI scanner for coincidence event selection. Initial detector performance measurement shows excellent crystal identification even with 30 mm long crystals, ~18% and 2.8 ns energy and timing resolutions, and around 2-3 mm DOI resolution. A large size detector panel can be scaled up with these modular detectors and different PET systems can be flexibly configured with the scalable readout electronics and data acquisition, providing an important design advantage for different system and application requirements. It is expected that standard shielding of detectors, electronics and signal transfer lines can be applied for simultaneous PET/MR imaging applications, with desired DOI measurement capability to enhance the PET performance and image quality.

Multiphase contrast-enhanced CT with highly concentrated contrast agent can be used for PET attenuation correction in integrated PET/CT imaging

International Nuclear Information System (INIS)

Aschoff, Philip; Plathow, Christian; Lichy, Matthias P.; Claussen, Claus D.; Pfannenberg, Christina; Beyer, Thomas; Erb, Gunter; Oeksuez, Mehmet Oe.

2012-01-01

State-of-the-art positron emission tomography/computed tomography (PET/CT) systems incorporate multislice CT technology, thus facilitating the acquisition of multiphase, contrast-enhanced CT data as part of integrated PET/CT imaging protocols. We assess the influence of a highly concentrated iodinated contrast medium (CM) on quantification and image quality following CT-based attenuation correction (CT-AC) in PET/CT. Twenty-eight patients with suspected malignant liver lesions were enrolled prospectively. PET/CT was performed 60 min after injection of 400 MBq of 18 F-fluorodeoxyglucose (FDG) and following the biphasic administration of an intravenous CM (400 mg iodine/ml, Iomeron 400). PET images were reconstructed with CT-AC using any of four acquired CT image sets: non-enhanced, pre-contrast (n-PET), arterial phase (art-PET), portal venous phase (pv-PET) and late phase (late-PET). Normal tissue activity and liver lesions were assessed visually and quantitatively on each PET/CT image set. Visual assessment of PET following CT-AC revealed no noticeable difference in image appearance or quality when using any of the four CT data sets for CT-AC. A total of 44 PET-positive liver lesions was identified in 21 of 28 patients. There were no false-negative or false-positive lesions on PET. Mean standardized uptake values (SUV) in 36 evaluable lesions were: 5.5 (n-PET), 5.8 (art-PET), 5.8 (pv-PET) and 5.8 (late-PET), with the highest mean increase in mean SUV of 6%. Mean SUV changes in liver background increased by up to 10% from n-PET to pv-PET. Multiphase CT data acquired with the use of highly concentrated CM can be used for qualitative assessment of liver lesions in torso FDG PET/CT. The influence on quantification of FDG uptake is small and negligible for most clinical applications. (orig.)

The role of 18F-FDG PET and PET/CT in the evaluation of primary cutaneous lymphoma.

Science.gov (United States)

Qiu, Lin; Tu, Guojian; Li, Jing; Chen, Yue

2017-02-01

Primary cutaneous lymphoma (PCL) is the second most common type of extranodal non-Hodgkin lymphoma, including both cutaneous T-cell and B-cell lymphomas. PCL comprises numerous subtypes and thus has myriad clinical presentations in the skin and subcutaneous tissues. Accurate classification and staging are important for making treatment recommendations for PCL and will further impact patient prognosis significantly. We review the role of fluorine-18-fluorodeoxyglucose (F-FDG) PET (F-FDG PET) and F-FDG PET with computed tomography (CT) in the diagnosis, staging, tumor biological evaluation, treatment response assessment, and early recurrence surveillance of PCL. Although F-FDG PET and PET/CT do not seem to adequately distinguish the plaque, patch, or erythroderma cutaneous lesions of PCL, the imaging modalities are superior to CT, MRI, and other nuclear medicine methods in detecting both the cutaneous and the extracutaneous lesions of PCL. The available literature addressing the clinical role of F-FDG PET and PET/CT in patients with PCL is promising for the use of the modalities in staging, tumor biological evaluation, biopsy guidance, early treatment response assessment, and recurrence surveillance. However, more data are needed to better specify the role of F-FDG PET and PET/CT in the management of PCL.

Accuracy of a clinical PET/CT vs. a preclinical μPET system for monitoring treatment effects in tumour xenografts

Energy Technology Data Exchange (ETDEWEB)

Palmowski, Karin [Department of Experimental Molecular Imaging, RWTH-Aachen University, Aachen (Germany); Department of Pneumology and Critical Care Medicine, Thoraxklinik Heidelberg, University of Heidelberg, Heidelberg (Germany); Winz, Oliver [Department of Nuclear Medicine, RWTH-Aachen University, Aachen (Germany); Rix, Anne; Bzyl, Jessica [Department of Experimental Molecular Imaging, RWTH-Aachen University, Aachen (Germany); Behrendt, Florian F.; Verburg, Frederic A.; Mottaghy, Felix M. [Department of Nuclear Medicine, RWTH-Aachen University, Aachen (Germany); Palmowski, Moritz, E-mail: mpalmowski@ukaachen.de [Department of Experimental Molecular Imaging, RWTH-Aachen University, Aachen (Germany); Department of Nuclear Medicine, RWTH-Aachen University, Aachen (Germany); Academic Radiology Baden Baden, Diagnostic and Interventional Radiology, University Medical Center Heidelberg, Heidelberg (Germany)

2013-08-15

Purpose: Small animal imaging is of growing importance for preclinical research and drug development. Tumour xenografts implanted in mice can be visualized with a clinical PET/CT (cPET); however, it is unclear whether early treatment effects can be monitored. Thus, we investigated the accuracy of a cPET versus a preclinical μPET using {sup 18}F-FDG for assessing early treatment effects. Materials and methods: The spatial resolution and the quantitative accuracy of a clinical and preclinical PET were evaluated in phantom experiments. To investigate the sensitivity for assessing treatment response, A431 tumour xenografts were implanted in nude mice. Glucose metabolism was measured in untreated controls and in two therapy groups (either one or four days of antiangiogenic treatment). Data was validated by γ-counting of explanted tissues. Results: In phantom experiments, cPET enabled reliable separation of boreholes ≥ 5 mm whereas μPET visualized boreholes ≥ 2 mm. In animal studies, μPET provided significantly higher tumour-to-muscle ratios for untreated control tumours than cPET (3.41 ± 0.87 vs. 1.60 ± .0.28, respectively; p < 0.01). During treatment, cPET detected significant therapy effects at day 4 (p < 0.05) whereas μPET revealed highly significant therapy effects even at day one (p < 0.01). Correspondingly, γ-counting of explanted tumours indicated significant therapy effects at day one and highly significant treatment response at day 4. Correlation with γ-counting was good for cPET (r = 0.74; p < 0.01) and excellent for μPET (r = 0.85; p < 0.01). Conclusion: Clinical PET is suited to investigate tumour xenografts ≥ 5 mm at an advanced time-point of treatment. For imaging smaller tumours or for the sensitive assessment of very early therapy effects, μPET should be preferred.

Hybrid imaging for detection of carcinoma of unknown primary: A preliminary comparison trial of whole-body PET/MRI versus PET/CT

International Nuclear Information System (INIS)

Ruhlmann, Verena; Ruhlmann, Marcus; Bellendorf, Alexander; Grueneisen, Johannes; Sawicki, Lino M.; Grafe, Hong; Forsting, Michael; Bockisch, Andreas; Umutlu, Lale

2016-01-01

Highlights: • Both 18F-FDG PET/CT and 18F-FDG PET/MRI provide a comparable diagnostic ability for detection of primary cancer and metastases in CUP-syndrome. • Both imaging methods showed comparably high lesion conspicuity and diagnostic confidence (superior assessment of cervical lesions in PET/MRI). • PET/MRI may serve as a powerful alternative, particularly for therapy monitoring or surveillance considering the long-term cumulative dose. - Abstract: Purpose: The aim of this study is to evaluate and compare the diagnostic potential of integrated whole-body [18F]FDG-PET/MRI to [18F]FDG-PET/CT for detection of a potential primary cancer and metastases in patients suspected for cancer of unknown primary (CUP). Methods: A total of 20 patients (15 male, 5 female, age 53 ± 13 years) suspect for CUP underwent a dedicated head and neck & whole-body [18F]FDG-PET/CT (Biograph mCT 128, Siemens Healthcare) and a subsequent simultaneous [18F]FDG-PET/MRI examination (Biograph mMR, Siemens Healthcare). Two readers rated the datasets (PET/CT; PET/MRI) regarding the detection of the primary cancer and metastases, lesion conspicuity (4-point ordinal scale) and diagnostic confidence (3-point ordinal scale). PET analysis comprised the assessment of maximum standardized uptake values (SUVmax) of all PET-positive lesions using volume of interest (VOI) analysis derived from the PET/CT and PET/MR datasets. All available data considering histology and imaging including prior and clinical follow-up examinations served as reference standard. Statistical analysis included comparison of mean values using Mann-Whitney U test and correlation of SUVmax using Pearson‘s correlation. Results: In 14 out of 20 patients 49 malignant lesions were present. The primary cancer could be correctly identified in 11/20 patients with both PET/CT and PET/MRI. PET/CT enabled the detection of a total 38 metastases, PET/MR respectively of 37 metastases (one lung metastasis <5mm was missed). PET/CT and

Hybrid imaging for detection of carcinoma of unknown primary: A preliminary comparison trial of whole-body PET/MRI versus PET/CT

Energy Technology Data Exchange (ETDEWEB)

Ruhlmann, Verena; Ruhlmann, Marcus; Bellendorf, Alexander [Department of Nuclear Medicine, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Grueneisen, Johannes [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Sawicki, Lino M. [Department of Diagnostic and Interventional Radiology, University of Dusseldorf, Moorenstraße 5, 40225 Dusseldorf (Germany); Grafe, Hong [Department of Nuclear Medicine, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Forsting, Michael [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Bockisch, Andreas [Department of Nuclear Medicine, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany); Umutlu, Lale, E-mail: verena.ruhlmann@uk-essen.de [Department of Nuclear Medicine, University Hospital Essen, University Duisburg-Essen, Hufelandstr. 55, 45122 Essen (Germany)

2016-11-15

Highlights: • Both 18F-FDG PET/CT and 18F-FDG PET/MRI provide a comparable diagnostic ability for detection of primary cancer and metastases in CUP-syndrome. • Both imaging methods showed comparably high lesion conspicuity and diagnostic confidence (superior assessment of cervical lesions in PET/MRI). • PET/MRI may serve as a powerful alternative, particularly for therapy monitoring or surveillance considering the long-term cumulative dose. - Abstract: Purpose: The aim of this study is to evaluate and compare the diagnostic potential of integrated whole-body [18F]FDG-PET/MRI to [18F]FDG-PET/CT for detection of a potential primary cancer and metastases in patients suspected for cancer of unknown primary (CUP). Methods: A total of 20 patients (15 male, 5 female, age 53 ± 13 years) suspect for CUP underwent a dedicated head and neck & whole-body [18F]FDG-PET/CT (Biograph mCT 128, Siemens Healthcare) and a subsequent simultaneous [18F]FDG-PET/MRI examination (Biograph mMR, Siemens Healthcare). Two readers rated the datasets (PET/CT; PET/MRI) regarding the detection of the primary cancer and metastases, lesion conspicuity (4-point ordinal scale) and diagnostic confidence (3-point ordinal scale). PET analysis comprised the assessment of maximum standardized uptake values (SUVmax) of all PET-positive lesions using volume of interest (VOI) analysis derived from the PET/CT and PET/MR datasets. All available data considering histology and imaging including prior and clinical follow-up examinations served as reference standard. Statistical analysis included comparison of mean values using Mann-Whitney U test and correlation of SUVmax using Pearson‘s correlation. Results: In 14 out of 20 patients 49 malignant lesions were present. The primary cancer could be correctly identified in 11/20 patients with both PET/CT and PET/MRI. PET/CT enabled the detection of a total 38 metastases, PET/MR respectively of 37 metastases (one lung metastasis <5mm was missed). PET/CT and

Blind source separation analysis of PET dynamic data: a simple method with exciting MR-PET applications

Energy Technology Data Exchange (ETDEWEB)

Oros-Peusquens, Ana-Maria; Silva, Nuno da [Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Weiss, Carolin [Department of Neurosurgery, University Hospital Cologne, 50924 Cologne (Germany); Stoffels, Gabrielle; Herzog, Hans; Langen, Karl J [Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Shah, N Jon [Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Jülich-Aachen Research Alliance (JARA) - Section JARA-Brain RWTH Aachen University, 52074 Aachen (Germany)

2014-07-29

Denoising of dynamic PET data improves parameter imaging by PET and is gaining momentum. This contribution describes an analysis of dynamic PET data by blind source separation methods and comparison of the results with MR-based brain properties.

Fast and Accurate Rat Head Motion Tracking With Point Sources for Awake Brain PET.

Science.gov (United States)

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

2017-07-01

To avoid the confounding effects of anesthesia and immobilization stress in rat brain positron emission tomography (PET), motion tracking-based unrestrained awake rat brain imaging is being developed. In this paper, we propose a fast and accurate rat headmotion tracking method based on small PET point sources. PET point sources (3-4) attached to the rat's head are tracked in image space using 15-32-ms time frames. Our point source tracking (PST) method was validated using a manually moved microDerenzo phantom that was simultaneously tracked with an optical tracker (OT) for comparison. The PST method was further validated in three awake [ 18 F]FDG rat brain scans. Compared with the OT, the PST-based correction at the same frame rate (31.2 Hz) reduced the reconstructed FWHM by 0.39-0.66 mm for the different tested rod sizes of the microDerenzo phantom. The FWHM could be further reduced by another 0.07-0.13 mm when increasing the PST frame rate (66.7 Hz). Regional brain [ 18 F]FDG uptake in the motion corrected scan was strongly correlated ( ) with that of the anesthetized reference scan for all three cases ( ). The proposed PST method allowed excellent and reproducible motion correction in awake in vivo experiments. In addition, there is no need of specialized tracking equipment or additional calibrations to be performed, the point sources are practically imperceptible to the rat, and PST is ideally suitable for small bore scanners, where optical tracking might be challenging.

PET/MRI for Neurological Applications

Science.gov (United States)

Catana, Ciprian; Drzezga, Alexander; Heiss, Wolf-Dieter; Rosen, Bruce R.

2013-01-01

PET and MRI provide complementary information in the study of the human brain. Simultaneous PET/MR data acquisition allows the spatial and temporal correlation of the measured signals, opening up opportunities impossible to realize using stand-alone instruments. This paper reviews the methodological improvements and potential neurological and psychiatric applications of this novel technology. We first present methods for improving the performance and information content of each modality by using the information provided by the other technique. On the PET side, we discuss methods that use the simultaneously acquired MR data to improve the PET data quantification. On the MR side, we present how improved PET quantification could be used to validate a number of MR techniques. Finally, we describe promising research, translational and clinical applications that could benefit from these advanced tools. PMID:23143086

PET/MRI for neurologic applications.

Science.gov (United States)

Catana, Ciprian; Drzezga, Alexander; Heiss, Wolf-Dieter; Rosen, Bruce R

2012-12-01

PET and MRI provide complementary information in the study of the human brain. Simultaneous PET/MRI data acquisition allows the spatial and temporal correlation of the measured signals, creating opportunities impossible to realize using stand-alone instruments. This paper reviews the methodologic improvements and potential neurologic and psychiatric applications of this novel technology. We first present methods for improving the performance and information content of each modality by using the information provided by the other technique. On the PET side, we discuss methods that use the simultaneously acquired MRI data to improve the PET data quantification. On the MRI side, we present how improved PET quantification can be used to validate several MRI techniques. Finally, we describe promising research, translational, and clinical applications that can benefit from these advanced tools.

Adapting MR-BrainPET scans for comparison with conventional PET: experiences with dynamic FET-PET in brain tumours

Energy Technology Data Exchange (ETDEWEB)

Lohmann, Philipp; Herzog, Hans; Kops, Elena Rota; Stoffels, Gabriele; Filss, Christian [Institute of Neuroscience and Medicine (INM-3,-4,-5), Forschungszentrum Juelich, Juelich (Germany); Galldiks, Norbert [Institute of Neuroscience and Medicine (INM-3,-4,-5), Forschungszentrum Juelich, Juelich (Germany); Department of Neurology, University of Cologne, Cologne (Germany); Coenen, Heinrich H; Shah, N Jon; Langen, Karl-Josef [Institute of Neuroscience and Medicine (INM-3,-4,-5), Forschungszentrum Juelich, Juelich (Germany)

2014-07-29

Imaging results from subsequent measurements (preclinical 3T MR-BrainPET, HR+) are compared. O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine (FET) may exhibit non-uniform tracer uptake in gliomas. The aim was to analyse and adapt the physical properties of the scanners and study variations of biological tumour volume (BTV) in early and late FET-PET.

PET in cerebrovascular disease; PET bei zerebrovaskulaeren Erkrankungen

Energy Technology Data Exchange (ETDEWEB)

Herholz, K. [Neurologische Universitaetsklinik der Univ. Koeln (Germany)]|[Max-Planck-Institut fuer Neurologische Forschung, Koeln (Germany)

1997-03-01

Tissue viability is of particular interest in acute cerebral ischemia because it may be preserved if reperfusion can be achieved rapidly, e.g. by acute thrombolysis. Measurements of regional cerebral blood flow (CBF) and oxygen consumption by PET can assess tissue viability, and they have substantially increased our knowledge of th pathophysiology of ischemic stroke and the associated penumbra. Widerspread clinical application in acute stroke, however, is unlikely because of the large logistic and personnel resources required. In chronic cerebrovascular disease, measurement of regional CBF and glucose metabolism, which is usually coupled, provide detailed insights in disturbance of cortical function, e.g. due to deafferentiation, and contribute to differentiation of dementia types. Chronic misery perfusion, i.e. reduced perfusion that does not match the metabolic demand of the tissue, can be demonstrated by PET. It may be found in some patients with high-grade arterial stenoses. Less severe impairment of brain perfusion can be demonstrated by measurement of the cerebrovascular reserve capacity. The most frequent clinical situations can be assessed by less demanding procedures, e.g. by SPECT. In conclusion, PET has its role in cerebrovascular disease primarily within scientific studies, where high resolution and absolute quantitation of physiological variables are essential. (orig.). 65 refs. [Deutsch] Beim akuten ischaemischen Insult ist die Vitalitaet des Gewebes von besonderem Interesse, da sie durch rasche Reperfusion, z.B. durch Thrombolyse, erhalten bleiben kann. Messungen der zerebralen Durchblutung und des Sauerstoffumsatzes mittels PET geben darueber wesentliche Aufschluesse, und sie sind wichtig fuer das Verstaendnis der Pathophysiologie ischaemischer Infarkte und der Penumbra mit kritischer Perfusion beim Menschen. Ihre breitere Anwendung in der klinischen Patientenversorgung kommt allerdings wegen des hohen Aufwandes derzeit kaum in Betracht. Bei

Dose-Dependent Effects of Radiation Therapy on Cerebral Blood Flow, Metabolism, and Neurocognitive Dysfunction

International Nuclear Information System (INIS)

Hahn, Carol A.; Zhou Sumin; Raynor, Renee; Tisch, Andrea; Light, Kim; Shafman, Timothy; Wong, Terence; Kirkpatrick, John; Turkington, Timothy; Hollis, Donna; Marks, Lawrence B.

2009-01-01

Purpose: A prospective study was performed to formally relate dose-dependent radiologically defined changes in normal brain induced by radiotherapy (RT) to neurocognitive dysfunction in subjects with primary brain tumors. Methods and Materials: Adult patients receiving three-dimensional RT for central nervous system (CNS) tumors were enrolled. Positron emission tomography (PET) scanning and neuropsychological testing were performed before RT and 3 weeks and 6 months after treatment. Analyses were performed for correlations between changes in 2-deoxy-2-[ 18 F]-fluoro-D-glucose (FDG)-PET (metabolism), 15 O-PET (relative blood flow), regional radiation dose, follow-up time, and neuropsychological test scores. Results: Eleven subjects were enrolled and 6 completed follow-up studies. The PET data showed reduced FDG uptake, with average decreases of 2-6% in regions of the brain receiving greater than 40 Gy at 3 weeks' and 6 months' follow-up. The 15 O-H 2 O PET showed increases (<10%) at 3 weeks in relative regional blood flow in brain receiving greater than 30 Gy, but less at the 6-month follow-up studies. There were significant correlations between decreases in FDG uptake and increased scores from the Symptom Checklist-90-R, with an average increase in T score of 2 (p < 0.0001). The Wisconsin Card Sorting Test showed a significant correlation of decreased FDG uptake with increased errors and perseveration in test performance, with an average decrease in T score of 11 (p = 0.037). Conclusions: A dose-dependent response of CNS tissue was detected using FDG PET in this small number of patients. Decreases in CNS metabolism correlated with decreased performance on neuropsychological tests for problem solving, cognitive flexibility, and global measures of psychopathology. Additional research is needed to verify and define these findings

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

NARCIS (Netherlands)

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

2012-01-01

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

Usefulness of abdominal belt for restricting respiratory cardiac motion and improving image quality in myocardial perfusion PET.

Science.gov (United States)

Ichikawa, Yasutaka; Tomita, Yoya; Ishida, Masaki; Kobayashi, Shigeki; Takeda, Kan; Sakuma, Hajime

2018-04-01

The current study evaluated the usefulness of a belt technique for restricting respiratory motion of the heart and for improving image quality of 13 N-ammonia myocardial PET/CT, and it assessed the tolerability of the belt technique in the clinical setting. Myocardial 13 N-ammonia PET/CT scanning was performed in 8 volunteers on Discovery PET/CT 690 with an optical respiratory motion tracking system. Emission scans were performed with and without an abdominal belt. The amplitude of left ventricular (LV) respiratory motion was measured on respiratory-gated PET images. The degree of erroneous decreases in regional myocardial uptake was visually assessed on ungated PET images using a 5-point scale (0 = normal, 1/2/3 = mild/moderate/severe decrease, 4 = defect). The tolerability of the belt technique was evaluated in 53 patients. All subjects tolerated the belt procedure. The amplitude of the LV respiratory motion decreased significantly with the belt (8.1 ± 7.1 vs 12.1 ± 6.1 mm, P = .0078). The belt significantly improved the image quality scores in the anterior (0.29 ± 0.81 vs 0.71 ± 1.04, P = .015) and inferior (0.33 ± 0.92 vs 1.04 ± 1.04, P PET/CT, and it is well tolerated by patients.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-09-15

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

Initial evaluation of a practical PET respiratory motion correction method in clinical simultaneous PET/MRI

International Nuclear Information System (INIS)

Manber, Richard; Thielemans, Kris; Hutton, Brian; Barnes, Anna; Ourselin, Sebastien; Arridge, Simon; O’Meara, Celia; Atkinson, David

2014-01-01

Respiratory motion during PET acquisitions can cause image artefacts, with sharpness and tracer quantification adversely affected due to count ‘smearing’. Motion correction by registration of PET gates becomes increasingly difficult with shorter scan times and less counts. The advent of simultaneous PET/MRI scanners allows the use of high spatial resolution MRI to capture motion states during respiration [1, 2]. In this work, we use a respiratory signal derived from the PET list-mode data [3, ], with no requirement for an external device or MR sequence modifications.

The application of PET/MRI in pancreatic neoplasms%PET/MRI在胰腺肿瘤中的应用

Institute of Scientific and Technical Information of China (English)

李旭东; 林晓珠

2018-01-01

PET/MRI是一种将PET和MRI融合的新型影像诊断技术,其整合了PET提供的人体生理代谢、分子信息和MRI提供的功能及解剖形态信息.相较于CT,MRI具有更高的软组织对比度,可多参数成像,且无辐射.PET/MRI在胰腺癌病灶检测、 术前分期和预后评估方面优于PET/CT.68Ga标记的生长抑素受体显像剂PET/MRI能够提高胰腺神经内分泌肿瘤的检测和诊断能力.新型显像剂的研发和应用能够提高胰腺肿瘤PET/MRI的特异性和精准性.就PET/MRI在胰腺癌的诊断、分期及疗效监测的应用价值及其对胰腺神经内分泌肿瘤的研究进展予以综述.%PET/MRI is a new medical imaging technology that can obtain hybrid images of PET and MRI simultane-ously,which integrates human physiological metabolism and molecular information from PET with functional and anatomical information from MRI.MRI has many advantages compared with computed tomography (CT),such as better soft tissue contrast, multiple parameters and no radiation.Researches showed that PET/MRI is superior to PET/CT in the detection, preoperative staging and prognosis of pancreatic cancers. PET/MRI using Somatostatin(SST) receptor with 68-Gallium (68Ga)-labeled can enhance the detection and diagnosis of pancreatic neuroendocrine tumors. The application of newly developed contrast media can improve specificity and accuracy of PET/MRI in diagnosing pancreatic tumors.In this paper, the values of PET/MRI in di-agnosis, staging and evaluating therapeutic effect in pancreatic cancer and progress of PET/MRI researches in pancreatic neu-roendocrine tumors were reviewed.

Monte Carlo simulation of second-generation open-type PET ''single-ring OpenPET'' implemented with DOI detectors

International Nuclear Information System (INIS)

Tashima, Hideaki; Yamaya, Taiga; Hirano, Yoshiyuki; Yoshida, Eiji; Kinouch, Shoko; Watanabe, Mitsuo; Tanaka, Eiichi

2013-01-01

At the National Institute of Radiological Sciences, we are developing OpenPET, an open-type positron emission tomography (PET) geometry with a physically open space, which allows easy access to the patient during PET studies. Our first-generation OpenPET system, dual-ring OpenPET, which consisted of two detector rings, could provide an extended axial field of view (FOV) including the open space. However, for applications such as in-beam PET to monitor the dose distribution in situ during particle therapy, higher sensitivity concentrated on the irradiation field is required rather than a wide FOV. In this report, we propose a second-generation OpenPET geometry, single-ring OpenPET, which can efficiently improve sensitivity while providing the required open space. When the proposed geometry was realized with block detectors, position-dependent degradation of the spatial resolution was expected because it was necessary to arrange the detector blocks in ellipsoidal rings stacked and shifted relative to one another. However, we found by Monte Carlo simulation that the use of depth-of-interaction (DOI) detectors made it feasible to achieve uniform spatial resolution in the FOV. (author)

PET with a dual-head coincidence gamma camera in head and neck cancer: A comparison with computed tomography and dedicated PET

International Nuclear Information System (INIS)

Zimny, M.

2001-01-01

Positron emission tomography with 18 F-fluoro-deoxyglucose (FDG PET) is a promising imaging tool for detecting and staging of primary or recurrent head and neck cancer. The aim of this study was to evaluate a dual-head gamma camera modified for coincidence detection (KGK-PET) in comparison to computed tomography (CT) and dedicated PET (dPET). 50 patients with known or suspected primary or recurrent head and neck cancer were enrolled. 32 patients underwent KGK-PET and dPET using a one-day protocol. The sensitivity for the detection of primary/ recurrent head and neck cancer for KGK-PET and CT was 80% and 54%, respectively, specificity was 73% and 82%, respectively. The sensitivity and specificity for the detection of lymph node metastases based on neck sides with KGK-PET was 71% (CT: 65%) and 88% (CT: 89%) respectively. In comparison to dPET, KGK-PET revealed concordant results in 32/32 patients with respect to primary tumor/recurrent disease and in 55/60 evaluated neck sides. All involved neck sides that were missed by KGK-PET were also negative with dPET. These results indicate that in patients with head and neck cancer KGK-PET reveals information, that are similar to dPET and complementary to CT. (orig.) [de

PET in management of breast cancer

International Nuclear Information System (INIS)

Lee, Myung-Chul

2004-01-01

Full text: PET provides useful information about tumor metabolism enabling accurate visualization of malignant lesions. Approximately 60-80% suspicious lesions on mammography have benign histology and about 10% of breast cancers with palpable mass are not identified in mammography. The key roles of PET technology in breast cancer are in: primary diagnosis, staging, recurrent diseases monitoring and prediction of therapy response. The sensitivity and specificity of FDG-PET for the diagnosis of breast cancer has been reported to be 68-100% and 83-100%, respectively. Considering the increasing number of small breast tumors detected by mammography and false negative results, the clinical relevance of FDG-PET for the primary diagnosis is limited. In selected patients, however, for example with dense breasts, breasts implants, augmented breast or after breast surgery, which can affect the accuracy of mammography, and in cases with equivocal mammography, FDG-PET can provide clinically relevant information. PET accurately determines the extent of disease, including the loco-regional lymph node status. Furthermore, whole-body PET imaging promises a high diagnostic accuracy for detecting recurrent or metastatic breast carcinoma with a high positive predictive value. We studied the usefulness of the FDG-PET in 42 preoperative patients with suspected breast cancer in differentiation of lesions. The diagnostic value of FDG-PET in terms of sensitivity and specificity was 95% and 77% respectively in primary mass while it was 73% and 100% for axillary lymph nodes. PET is much more accurate than other conventional modalities. The sensitivity of FDG-PET for correct staging of axillary nodal status is 84-100%. It has the potential to replace conventional procedures for the staging of distant metastases. We observed the sensitivity and the specificity of FDG-PET to be 96% and 85% to detect distant metastases. FDG-PET may become the method of choice for the early assessment of

The system of the designing for PET detectors

International Nuclear Information System (INIS)

Fang Zongliang

2006-01-01

PET stands for Positron Emission Tomography, a new nuclear medicine imaging device. PET detector is the key of PET. This paper introduces a system of the designing for PET detector. The system can be used to design various PET detector. A PET detector BLOCK with 8 x 8 crystals has been designed and built by this system. (authors)

Detection and quantification of focal uptake in head and neck tumours: {sup 18}F-FDG PET/MR versus PET/CT

Energy Technology Data Exchange (ETDEWEB)

Varoquaux, Arthur; Rager, Olivier; Ratib, Osman; Becker, Christoph D.; Zaidi, Habib; Becker, Minerva [Geneva University Hospital, Department of Imaging, Divisions of Radiology and Nuclear Medicine, Geneva 14 (Switzerland); Poncet, Antoine [Geneva University Hospital, Center for Clinical Research, Geneva (Switzerland); Delattre, Benedicte M.A. [Geneva University Hospital, Department of Imaging, Divisions of Radiology and Nuclear Medicine, Geneva 14 (Switzerland); Philips Healthcare AG, Nuclear Medicine Division, Gland (Switzerland); Dulguerov, Pavel; Dulguerov, Nicolas [Geneva University Hospital, Clinic of Otorhinolaryngology Head and Neck Surgery, Geneva (Switzerland)

2014-03-15

Our objectives were to assess the quality of PET images and coregistered anatomic images obtained with PET/MR, to evaluate the detection of focal uptake and SUV, and to compare these findings with those of PET/CT in patients with head and neck tumours. The study group comprised 32 consecutive patients with malignant head and neck tumours who underwent whole-body {sup 18}F-FDG PET/MR and PET/CT. PET images were reconstructed using the attenuation correction sequence for PET/MR and CT for PET/CT. Two experienced observers evaluated the anonymized data. They evaluated image and fusion quality, lesion conspicuity, anatomic location, number and size of categorized (benign versus assumed malignant) lesions with focal uptake. Region of interest (ROI) analysis was performed to determine SUVs of lesions and organs for both modalities. Statistical analysis considered data clustering due to multiple lesions per patient. PET/MR coregistration and image fusion was feasible in all patients. The analysis included 66 malignant lesions (tumours, metastatic lymph nodes and distant metastases), 136 benign lesions and 470 organ ROIs. There was no statistically significant difference between PET/MR and PET/CT regarding rating scores for image quality, fusion quality, lesion conspicuity or anatomic location, number of detected lesions and number of patients with and without malignant lesions. A high correlation was observed for SUV{sub mean} and SUV{sub max} measured on PET/MR and PET/CT for malignant lesions, benign lesions and organs (ρ = 0.787 to 0.877, p < 0.001). SUV{sub mean} and SUV{sub max} measured on PET/MR were significantly lower than on PET/CT for malignant tumours, metastatic neck nodes, benign lesions, bone marrow, and liver (p < 0.05). The main factor affecting the difference between SUVs in malignant lesions was tumour size (p < 0.01). In patients with head and neck tumours, PET/MR showed equivalent performance to PET/CT in terms of qualitative results. Comparison of

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-01-15

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

Side-by-side reading of PET and CT scans in oncology: Which patients might profit from integrated PET/CT?

International Nuclear Information System (INIS)

Reinartz, Patrick; Wieres, Franz-Josef; Schneider, Wolfram; Schur, Alexander; Buell, Ulrich

2004-01-01

Most early publications on integrated positron emission tomography/computed tomography (PET/CT) devices have reported the new scanner generation to be superior to conventional PET. However, few of these studies have analysed the situation where, in addition to PET, a current CT scan is available for side-by-side viewing. This fact is important, because combined PET/CT or a software-based fusion of the two modalities may improve diagnosis only in cases where side-by-side reading of PET and CT data does not lead to a definitive diagnosis. The aim of this study was to analyse which patients will profit from integrated PET/CT in terms of lesion characterization. A total of 328 consecutively admitted patients referred for PET in whom a current CT scan was available were included in the study. The localization of all pathological PET lesions, as well as possible infiltration of adjacent anatomical structures, was assessed. Of 467 pathological lesions, 94.0% were correctly assessed with respect to localization and infiltration by either conventional PET alone (51.6%) or combined reading of PET and the already existing CT scans (42.4%). Hence, in only 6.0% of all lesions, affecting 6.7% of all patients, could evaluation have profited from integrated PET/CT. We conclude that side-by-side viewing of PET and CT scans is essential, as in 42.4% of all cases, combined viewing was important for a correct diagnosis in our series. In up to 6.7% of patients, integrated PET/CT might have given additional information, so that in nearly 50% of patients some form of combined viewing of PET and CT data is needed for accurate lesion characterization. (orig.)

A contactless approach for respiratory gating in PET using continuous-wave radar.

Science.gov (United States)

Ersepke, Thomas; Büther, Florian; Heß, Mirco; Schäfers, Klaus P

2015-08-01

Respiratory gating is commonly used to reduce motion artifacts in positron emission tomography (PET). Clinically established methods for respiratory gating in PET require contact to the patient or a direct optical line between the sensor and the patient's torso and time consuming preparation. In this work, a contactless method for capturing a respiratory signal during PET is presented based on continuous-wave radar. The proposed method relies on the principle of emitting an electromagnetic wave and detecting the phase shift of the reflected wave, modulated due to the respiratory movement of the patient's torso. A 24 GHz carrier frequency was chosen allowing wave propagation through plastic and clothing with high reflections at the skin surface. A detector module and signal processing algorithms were developed to extract a quantitative respiratory signal. The sensor was validated using a high precision linear table. During volunteer measurements and [(18)F] FDG PET scans, the radar sensor was positioned inside the scanner bore of a PET/computed tomography scanner. As reference, pressure belt (one volunteer), depth camera-based (two volunteers, two patients), and PET data-driven (six patients) signals were acquired simultaneously and the signal correlation was quantified. The developed system demonstrated a high measurement accuracy for movement detection within the submillimeter range. With the proposed method, small displacements of 25 μm could be detected, not considerably influenced by clothing or blankets. From the patient studies, the extracted respiratory radar signals revealed high correlation (Pearson correlation coefficient) to those derived from the external pressure belt and depth camera signals (r = 0.69-0.99) and moderate correlation to those of the internal data-driven signals (r = 0.53-0.70). In some cases, a cardiac signal could be visualized, due to the representation of the mechanical heart motion on the skin. Accurate respiratory signals were

Initial experience on protocol optimization for integrated PET/MR%PET/MR一体机操作优化的初步经验

Institute of Scientific and Technical Information of China (English)

刘家金; 陈英茂; 张雄伟; 富丽萍; 田嘉禾; 尹大一; 徐白萱

2014-01-01

目的 通过比较PET/CT和PET/MR,初步探索PET/MR一体机的操作流程和成像优化方案.方法 228例患者同日内接受PET/CT和PET/MR检查,通过6种不同MR序列与PET采集组合方案,比较图像质量的优劣,以在保证诊断信息基础上缩短患者扫描时间的原则分析判断,并初步确定最优PET/MR一体机采集方案.结果 PET/MR结果与PET/CT相近,但其操作流程和注意事项有独特之处;在6种方案中,以躯干和头部各有独立序列组合、兼顾各向同性结构显示与突出病灶特点的方案6效果最优;PET/MR比PET/CT更易产生伪影.结论 在优化方案基础上,PET/MR可获得与PET/CT一致的诊断级图像,但PET/MR采集时间长、伪影多,有待进一步完善.%Objective To investigate the optimal workflow and protocol for integrated PET/MR by comparison with PET/CT.Methods A total of 228 patients were enrolled in this study for PET/CT and PET/MR evaluation on the same day.Six PET/MR protocols with different MR sequences but the same PET acquisition protocol were investigated and the optimal protocol was identified based on image quality,acquisition time and diagnostic performance.Results PET/MR workflow was similar to PET/CT,however,some special issues needed to be considered for PET/MR.Among the 6 protocols,protocol No.6 outperformed others for body and head regions.Types of artifacts were found more often in PET/MR than in PET/CT.Conclusions By optimizing the protocol,PET/MR could achieve almost the same diagnostic performance as PET/CT.However,the issues of long acquisition time and artifacts on PET/MR need to be further improved.

A dual layer DOI GSO block detector for a small animal PET

International Nuclear Information System (INIS)

Yamamoto, Seiichi

2009-01-01

For a high resolution animal positron emission tomography (PET), depth-of-interaction (DOI) is a useful method to improve both spatial resolution and sensitivity. Gd 2 SiO 5 (GSO) with different amounts of Ce can provide different decay times and is ideal for DOI detector using pulse shape analysis. Dual layer DOI GSO block detectors using different amounts of Ce were developed for a new animal PET. The DOI GSO block detector employed two types of GSOs; one with 1.5 mol% Ce concentration (decay time: 35 ns) and the other with 0.5 mol% (decay time: 60 ns). These two GSO types were optically coupled in the DOI direction. The sizes of single GSOs were 1.9 mmx1.9 mmx6 mm and 1.9 mmx1.9 mmx9 mm, for 1.5 and 0.5 mol%, respectively. These GSO were arranged by 11x37 matrix and optically coupled to three position sensitive photomultiplier tubes (PSPMTs), where the PSPMTs used were Hamamatsu R8520U-00-C12. Different lengths of reflectors were used between crystals to increase the useful field-of-view (FOV) of the PSPMT and to avoid the dead areas between PSPMTs. With this configuration, almost all islands in a 2-D position histogram corresponding to GSO cells could be separated. The width of the GSO block was 22 mm in the transaxial direction and 74 mm in axial direction with no gaps. Also, two types of GSO of different decay time could be separated using dual integration method for pulse shape analysis. These results indicate that developed block detectors might be useful for a high resolution and high sensitivity animal PET with dual layer DOI detection capability, with no gaps in transaxial or axial directions.

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-08-15

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

Development of a PET Insert for simultaneously small animal PET/MRI

Energy Technology Data Exchange (ETDEWEB)

Wang, Yingjie; Zhang, Zhiming; Li, Daowu; Liu, Shuangquan; Wang, Peilin; Feng, Baotong; Chai, Pei; Wei, Long [Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 (China); Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing, 100049 (China)

2015-05-18

PET/MR is a new multi-modality imaging system which provide both structural and functional information with good soft tissue imaging ability and no ionizing radiation. In recent years, PET/MR is under major progress because of the development of silicon photomultipliers (SiPM). The goal of this study is to develop a MRI compatible PET insert based on SiPM and LYSO scintillator. The PET system was constituted by the detector ring, electronics and software. The detector ring consists of 16 detector module. The inner diameter of the ring was 151 mm, the external diameter was 216 mm, which was big enough for small animal research, e.g. rat, rabbit and tupaia. The sensor of each module was 2*2 SensL SPMArraySL, coupled with an array of 14 x 14 LYSO crystals, each crystal measuring 2 mm x 2 mm 10 mm. The detector was encapsulated in a copper box for light and magnetic shielding. Resister charge multiplexing circuit was used in the front end electronics. Each detector output 8X and 8Y position signals. One summed timing signal was extracted from the common cathode of all 64 channels. All these signals were transmitted to digital electronic board by a 3 m long coaxial cable from inside of the MR to the outside. Each digital electronic board handled 8 detector modules based on FPGA to obtain the timing, position and energy information of a single event. And then these single events were sent to the coincidence processing board to produce coincidence packets which are prepared for further processing. A 0.2mCi 68Ge line source was used to do the preliminary imaging test. The image was reconstructed by 3D-OSEM algorithm. The initial result proved the system to be feasible as a PET. FDG phantom imaging and simultaneous PET/MR imaging are in progress.

Pet ownership and older women: the relationships among loneliness, pet attachment support, human social support, and depressed mood.

Science.gov (United States)

Krause-Parello, Cheryl A

2012-01-01

Pets can play a positive role in the both the physical and psychological health of older adults. This cross sectional study investigated the relationships among loneliness, pet attachment support, human social support, and depressed mood in a convenience sample of 159 pet-owning older women residing in the community. Participants completed loneliness, pet attachment support, human social support, and depressed mood scales. The results supported significant relationships between loneliness, pet attachment support, human social support, and depressed mood. No relationship was found between human social support and depressed mood. Pet attachment support, but not human social support, influenced the relationship between loneliness and depressed mood indicating the importance of pet attachment as a greater form of support in this sample. Clinical and social implications for nurses working with the geriatric population were identified and discussed. Copyright © 2012 Mosby, Inc. All rights reserved.

Effects of pre-strain applied at a polyethylene terephthalate substrate before the coating of TiO2 film on the coating film quality and optical performance

International Nuclear Information System (INIS)

Li, Tse-Chang; Wu, Bo-Hsiung; Lin, Jen-Fin

2011-01-01

A mold was designed to create various strains in polyethylene terephthalate (PET) substrates before the deposition of TiO 2 film to simulate deposition process on a cylindrical drum. The residual stress of the PET substrate with TiO 2 film significantly increased with increasing strain, decreasing the radius of curvature. Compared to the as-received PET substrate, there was a noticeable increase in the surface roughness in the PET/TiO 2 specimens when a large strain was applied. The formation of voids or cavities in the TiO 2 layer significantly increased the roughness of the specimen. The mean cavity size and depth increased with increasing strain. For strains ≤ 4%, the specimen's hardness and Young's modulus factored by the voids/cavities increased with increasing surface roughness. The optical absorption increased with increasing surface roughness before becoming asymptotic to a constant value. The strain applied to the PET substrate before TiO 2 deposition greatly affects the optical reflection, transmittance, and absorption.

Additional value of integrated PET/CT over PET alone in the initial staging and follow up of head and neck malignancy

International Nuclear Information System (INIS)

Ishikita, Tomohiro; Oriuchi, Noboru; Higuchi, Tetsuya

2010-01-01

Clinical application of fluorodeoxyglucose (FDG)-positron emission tomography (PET) in head and neck cancer includes identification of metastases, unknown primary head and neck malignancy, or second primary carcinoma, and also recurrent tumor after treatment. In this study, the additional value of PET/CT fusion images over PET images alone was evaluated in patients with initial staging and follow up of head and neck malignancy. Forty patients with suspected primary head and neck malignancy and 129 patients with suspected relapse after treatment of head and neck malignancy were included. FDG-PET/CT study was performed after the intravenous administration of FDG (5 MBq/kg). Target of evaluation was set at primary tumor, cervical lymph node, and whole body. PET images and PET with CT fusion images were compared. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results of PET and PET/CT were compared with postoperative histopathological examination, and case by case comparison of PET and PET/CT results for each region was performed. The additional value of CT images over PET only images was assessed. Statistical differences in sensitivity and specificity were evaluated. In the comparative evaluation of 507 targets by PET alone and PET/CT, 401 targets showed agreement of the results. Of the 106 discordant targets, 103 showed a positive result on PET alone and negative result on PET/CT. These results showed a significant difference (p<0.01). Sensitivity of PET/CT was slightly higher than that of PET without statistical significance, while specificity of PET/CT was significantly higher than that of PET alone (Initial Staging: 90.5% vs. 62.2%, p<0.01; Follow up: 97.2% vs. 74.4%, p<0.01). In Fisher's direct probability test, a significant difference was noted in the sensitivity (Initial staging: 91.3% vs. 87.0%, p<0.01; Follow up: 93.9% vs. 91.4%, p<0.01). Combined PET/CT showed improved diagnostic

PET/MRI: Technical challenges and recent advances

International Nuclear Information System (INIS)

Jung, Jin Ho; Choi, Yong; Im, Ki Chun

2016-01-01

Integrated positron emission tomography (PET)/magnetic resonance imaging (MRI), which can provide complementary functional and anatomical information about a specific organ or body system at the molecular level, has become a powerful imaging modality to understand the molecular biology details, disease mechanisms, and pharmacokinetics in animals and humans. Although the first experiment on the PET/MRI was performed in the early 1990s, its clinical application was accomplished in recent years because there were various technical challenges in integrating PET and MRI in a single system with minimum mutual interference between PET and MRI. This paper presents the technical challenges and recent advances in combining PET and MRI along with several approaches for improving PET image quality of the PET/MRI hybrid imaging system

PET in neuro-oncology

NARCIS (Netherlands)

Roelcke, U; Leenders, K.L.

This article reviews possible clinical applications of positron emission tomography (PET) in brain tumor patients. PET allows quantitative assessment of brain tumor pathophysiology and biochemistry. It therefore provides different information about tumors when compared to histological or

Radiation monitoring of PET staff

International Nuclear Information System (INIS)

Trang, A.

2004-01-01

Full text: Positron emission tomography (PET) is becoming a common diagnostic tool in hospitals, often located in and employing staff from the Nuclear Medicine or Radiology departments. Although similar in some ways, staff in PET departments are commonly found to have the highest radiation doses in the hospital environment due to unique challenges which PET tracers present in administration as well as production. The establishment of a PET centre with a dedicated cyclotron has raised concerns of radiation protection to the staff at the WA PET Centre and the Radiopharmaceutical Production and Development (RAPID) team. Since every PET centre has differing designs and practices, it was considered important to closely monitor the radiation dose to our staff so that improvements to practices and design could be made to reduce radiation dose. Electronic dosimeters (MGP DMC 2000XB), which have a facility to log time and dose at 10 second intervals, were provided to three PET technologists and three PET nurses. These were worn in the top pocket of their lab coats throughout a whole day. Each staff member was then asked to note down their duties throughout the day and also note the time they performed each duty. The duties would then correlate with the dose with which the electronic monitor recorded and an estimate of radiation dose per duty could be given. Also an estimate of the dose per day to each staff member could be made. PET nurses averaged approximately 20 μ8v per day getting their largest dose from caring for occasional problematic patients. Smaller doses of a 1-2 μ8v were recorded for injections and removing cannulas. PET technologists averaged approximately 15 μ8v per day getting their largest dose of 1-5μ8v mainly from positioning of patients and sometimes larger doses due to problematic patients. Smaller doses of 1-2 μ5v were again recorded for injections and removal of cannulas. Following a presentation given to staff, all WA PET Centre and RAPID staff

What do we measure in oncology PET?

Energy Technology Data Exchange (ETDEWEB)

Pak, Kyoung June; Kim, Seong Jang [Dept. of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan (Korea, Republic of)

2017-09-15

Positron emission tomography (PET) has come to the practice of oncology. It is known that {sup 18}F-fluorodeoxyglucose (FDG) PET is more sensitive for the assessment of treatment response than conventional imaging. In addition, PET has an advantage in the use of quantitative analysis of the study. Nowadays, various PET parameters are adopted in clinical settings. In addition, a wide range of factors has been known to be associated with FDG uptake. Therefore, there has been a need for standardization and harmonization of protocols and PET parameters. We will introduce PET parameters and discuss major issues in this review.

TH-E-202-00: PET for Radiation Therapy

International Nuclear Information System (INIS)

2016-01-01

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss: Pitfalls and remedies in PET/CT imaging for RT planning The use of hypoxia PET imaging for radiotherapy PET for tumor response evaluation The first presentation will address the issue of mis-registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image-guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de-escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi-quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non-FDG PET tracers for response assessment. Learning Objectives: Identify the causes of mis-registration of CT and PET images in PET/CT, and review the strategies to remedy the issue. Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo-radiation therapy). Understand the basics of dynamic PET imaging, compartmental modeling and parametric images. Understand the

TH-E-202-00: PET for Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

NONE

2016-06-15

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss: Pitfalls and remedies in PET/CT imaging for RT planning The use of hypoxia PET imaging for radiotherapy PET for tumor response evaluation The first presentation will address the issue of mis-registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image-guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de-escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi-quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non-FDG PET tracers for response assessment. Learning Objectives: Identify the causes of mis-registration of CT and PET images in PET/CT, and review the strategies to remedy the issue. Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo-radiation therapy). Understand the basics of dynamic PET imaging, compartmental modeling and parametric images. Understand the

Coincidence detection FDG-PET (Co-PET) in the management of oncological patients: attenuation correction versus non-attenuation correction

International Nuclear Information System (INIS)

Chan, W.L.; Freund, J.; Pocock, N.; Szeto, E.; Chan, F.; Sorensen, B.; McBride, B.

2000-01-01

Full text: This study was to determine if attenuation correction (AC) in FDG Co-PET improved image quality, lesion detection, patient staging and management of various malignant neoplasms, compared to non-attenuation-corrected (NAC) images. Thirty patients (25 men, 5 women, mean age 58 years) with known or suspected malignant neoplasms, including non-small-cell lung cancer, non Hodgkin's and Hodgkin's lymphoma, carcinoma of the breast, head and neck cancer and melanoma, underwent FDG Co-PET, which was correlated with histopathology, CT and other conventional imaging modalities and clinical follow-up. Whole body tomography was performed (ADAC Vertex MCD) 60 min after 200 MBq of 18 F-FDG (>6h fasting). The number and location of FDG avid lesions detected on the AC images and NAC Co-PET images were blindly assessed by two independent observers. Semi-quantitative grading of image clarity and lesion-to-background quality was performed. This revealed markedly improved image clarity and lesion-to-background quality, in the AC versus NAC images. AC and NAC Co-PET were statistically different in relation to lesion detection (p<0.01) and tumour staging (p<0.0 1). NAC Co-PET demonstrated 51 of the 65 lesions (78%) detected by AC Co-PET. AC Co-PET staging was correct in 27 patients (90%), compared with NAC Co-PET in 22 patients (73%). AC Co-PET altered tumour staging in five of 30 patients (16%) and NAC Co-PET did not alter tumour staging in any of the patients- management was altered in only two of these five patients (7%). In conclusion, AC Co-PET resulted in better image quality with significantly improved lesion detectability and tumour staging compared to NAC Co-PET. Its additional impact on patient management in this relatively small sample was minor. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

Compensation for photon attenuation in PET

International Nuclear Information System (INIS)

Chintu Chen; Ordonez, C.E.; Xiaolin Yu.

1992-01-01

CT/MR and PET images usually are not in registration spatially because of differences in the imaging setup. CT, MR and PET imaging parameters that are used regularly for brain studies in their institution are compared, in addition, because the patient orientations in CT/MR and PET scanners are not the same, slice centers are positioned differently relative to the patients anatomy. For application of the new idea of using structural information from CT or MR images in PET image reconstruction for attenuation correction, image registration is required as a first step so that one can obtain a corresponding anatomic map for any selected PET image plane. The authors chose to use the surface-matching technique developed in their laboratories for image registration because this method is retrospective and accurate. After the PET and CT/MR scans are registered, they reslice the CT/MR images along the planes of the PET images. The differences in slice thickness and slice separation, as well as in image resolution between various image modalities are to be considered

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Application of PET in brain tumor