Image reconstruction from projections and its application in emission computer tomography

International Nuclear Information System (INIS)

Kuba, Attila; Csernay, Laszlo

1989-01-01

Computer tomography is an imaging technique for producing cross sectional images by reconstruction from projections. Its two main branches are called transmission and emission computer tomography, TCT and ECT, resp. After an overview of the theory and practice of TCT and ECT, the first Hungarian ECT type MB 9300 SPECT consisting of a gamma camera and Ketronic Medax N computer is described, and its applications to radiological patient observations are discussed briefly. (R.P.) 28 refs.; 4 figs

DE-BLURRING SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY IMAGES USING WAVELET DECOMPOSITION

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Neethu M. Sasi

2016-02-01

Full Text Available Single photon emission computed tomography imaging is a popular nuclear medicine imaging technique which generates images by detecting radiations emitted by radioactive isotopes injected in the human body. Scattering of these emitted radiations introduces blur in this type of images. This paper proposes an image processing technique to enhance cardiac single photon emission computed tomography images by reducing the blur in the image. The algorithm works in two main stages. In the first stage a maximum likelihood estimate of the point spread function and the true image is obtained. In the second stage Lucy Richardson algorithm is applied on the selected wavelet coefficients of the true image estimate. The significant contribution of this paper is that processing of images is done in the wavelet domain. Pre-filtering is also done as a sub stage to avoid unwanted ringing effects. Real cardiac images are used for the quantitative and qualitative evaluations of the algorithm. Blur metric, peak signal to noise ratio and Tenengrad criterion are used as quantitative measures. Comparison against other existing de-blurring algorithms is also done. The simulation results indicate that the proposed method effectively reduces blur present in the image.

Myocardial blood flow quantification for evaluation of coronary artery disease by positron emission tomography, cardiac magnetic resonance imaging, and computed tomography.

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Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond Y; Di Carli, Marcelo F

2014-05-01

The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging, and computed tomography, and its emerging clinical applications.

Attenuation Correction Strategies for Positron Emission Tomography/Computed Tomography and 4-Dimensional Positron Emission Tomography/Computed Tomography

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Pan, Tinsu; Zaidi, Habib

2013-01-01

This article discusses attenuation correction strategies in positron emission tomography/computed tomography (PET/CT) and 4 dimensional PET/CT imaging. Average CT scan derived from averaging the high temporal resolution CT images is effective in improving the registration of the CT and the PET images and quantification of the PET data. It underscores list mode data acquisition in 4 dimensional PET and introduces 4 dimensional CT popular in thoracic treatment planning to 4 dimensional PET/CT. ...

Positron Emission Tomography/Magnetic Resonance Imaging for Local Tumor Staging in Patients With Primary Breast Cancer: A Comparison With Positron Emission Tomography/Computed Tomography and Magnetic Resonance Imaging.

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Grueneisen, Johannes; Nagarajah, James; Buchbender, Christian; Hoffmann, Oliver; Schaarschmidt, Benedikt Michael; Poeppel, Thorsten; Forsting, Michael; Quick, Harald H; Umutlu, Lale; Kinner, Sonja

2015-08-01

This study aimed to assess the diagnostic performance of integrated positron emission tomography (PET)/magnetic resonance imaging (MRI) of the breast for lesion detection and local tumor staging of patients with primary breast cancer in comparison to PET/computed tomography (CT) and MRI. The study was approved by the local institutional review board. Forty-nine patients with biopsy-proven invasive breast cancer were prospectively enrolled in our study. All patients underwent a PET/CT, and subsequently, a contrast-enhanced PET/MRI of the breast after written informed consent was obtained before each examination. Two radiologists independently evaluated the corresponding data sets (PET/CT, PET/MRI, and MRI) and were instructed to identify primary tumors lesions as well as multifocal/multicentric and bilateral disease. Furthermore, the occurrence of lymph node metastases was assessed, and the T-stage for each patient was determined. Histopathological verification of the local tumor extent and the axillary lymph node status was available for 30 of 49 and 48 of 49 patients, respectively. For the remaining patients, a consensus characterization was performed for the determination of the T-stage and nodal status, taking into account the results of clinical staging, PET/CT, and PET/MRI examinations. Statistical analysis was performed to test for differences in diagnostic performance between the different imaging procedures. P values less than 0.05 were considered to be statistically significant. Positron emission tomography/MRI and MRI correctly identified 47 (96%) of the 49 patients with primary breast cancer, whereas PET/CT enabled detection of 46 (94%) of 49 breast cancer patients and missed a synchronous carcinoma in the contralateral breast in 1 patient. In a lesion-by-lesion analysis, no significant differences could be obtained between the 3 imaging procedures for the identification of primary breast cancer lesions (P > 0.05). Positron emission tomography/MRI and

Imaging of the dopaminergic neurotransmission system using single-photon emission tomography and positron emission tomography in patients with parkinsonism

International Nuclear Information System (INIS)

Booij, J.; Tissingh, G.; Winogrodzka, A.; Royen, E.A. van

1999-01-01

Parkinsonism is a feature of a number of neurodegenerative diseases, including Parkinson's disease, multiple system atrophy and progressive supranuclear palsy. The results of post-mortem studies point to dysfunction of the dopaminergic neurotransmitter system in patients with parkinsonism. Nowadays, by using single-photon emission tomography (SPET) and positron emission tomography (PET) it is possible to visualise both the nigrostriatal dopaminergic neurons and the striatal dopamine D 2 receptors in vivo. Consequently, SPET and PET imaging of elements of the dopaminergic system can play an important role in the diagnosis of several parkinsonian syndromes. This review concentrates on findings of SPET and PET studies of the dopaminergic neurotransmitter system in various parkinsonian syndromes. (orig.)

Positron Emission Tomography imaging with the SmartPET system

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Cooper, R.J. [Department of Physics, University of Liverpool, Liverpool, Merseyside L69 7ZE (United Kingdom)], E-mail: cooperrj@ornl.gov; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Grint, A.N.; Harkness, L.J.; Nolan, P.J.; Oxley, D.C.; Scraggs, D.P.; Mather, A.R. [Department of Physics, University of Liverpool, Liverpool, Merseyside L69 7ZE (United Kingdom); Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom)

2009-07-21

The Small Animal Reconstruction Tomograph for Positron Emission Tomography (SmartPET) project is the development of a small animal Positron Emission Tomography (PET) demonstrator based on the use of High-Purity Germanium (HPGe) detectors and state of the art digital electronics. The experimental results presented demonstrate the current performance of this unique system. By performing high precision measurements of one of the SmartPET HPGe detectors with a range of finely collimated gamma-ray beams the response of the detector as a function of gamma-ray interaction position has been quantified, facilitating the development of parametric Pulse Shape Analysis (PSA) techniques and algorithms for the correction of imperfections in detector performance. These algorithms have then been applied to data from PET imaging measurements using two such detectors in conjunction with a specially designed rotating gantry. In this paper we show how the use of parametric PSA approaches allows over 60% of coincident events to be processed and how the nature and complexity of an event has direct implications for the quality of the resulting image.

RELIABILITY OF POSITRON EMISSION TOMOGRAPHY-COMPUTED TOMOGRAPHY IN EVALUATION OF TESTICULAR CARCINOMA PATIENTS.

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Nikoletić, Katarina; Mihailović, Jasna; Matovina, Emil; Žeravica, Radmila; Srbovan, Dolores

2015-01-01

The study was aimed at assessing the reliability of 18F-fluorodeoxyglucose positron emission tomography-computed tomography scan in evaluation of testicular carcinoma patients. The study sample consisted of 26 scans performed in 23 patients with testicular carcinoma. According to the pathohistological finding, 14 patients had seminomas, 7 had nonseminomas and 2 patients had a mixed histological type. In 17 patients, the initial treatment was orchiectomy+chemotherapy, 2 patients had orchiectomy+chemotherapy+retroperitoneal lymph node dissection, 3 patients had orchiectomy only and one patient was treated with chemotherapy only. Abnormal computed tomography was the main cause for the oncologist to refer the patient to positron emission tomography-computed tomography scan (in 19 scans), magnetic resonance imaging abnormalities in 1 scan, high level oftumor markers in 3 and 3 scans were perforned for follow-up. Positron emission tomography-computed tomography imaging results were compared with histological results, other imaging modalities or the clinical follow-up of the patients. Positron emission tomography-computed tomography scans were positive in 6 and negative in 20 patients. In two patients, positron emission tomography-computed tomography was false positive. There were 20 negative positron emission omography-computed tomography scans perforned in 18 patients, one patient was lost for data analysis. Clinically stable disease was confirmed in 18 follow-up scans performed in 16 patients. The values of sensitivty, specificity, accuracy, and positive- and negative predictive value were 60%, 95%, 75%, 88% and 90.5%, respectively. A hgh negative predictive value obtained in our study (90.5%) suggests that there is a small possibility for a patient to have future relapse after normal positron emission tomography-computed tomography study. However, since the sensitivity and positive predictive value of the study ire rather low, there are limitations of positive

Data analysis in emission tomography using emission-count posteriors

International Nuclear Information System (INIS)

Sitek, Arkadiusz

2012-01-01

A novel approach to the analysis of emission tomography data using the posterior probability of the number of emissions per voxel (emission count) conditioned on acquired tomographic data is explored. The posterior is derived from the prior and the Poisson likelihood of the emission-count data by marginalizing voxel activities. Based on emission-count posteriors, examples of Bayesian analysis including estimation and classification tasks in emission tomography are provided. The application of the method to computer simulations of 2D tomography is demonstrated. In particular, the minimum-mean-square-error point estimator of the emission count is demonstrated. The process of finding this estimator can be considered as a tomographic image reconstruction technique since the estimates of the number of emissions per voxel divided by voxel sensitivities and acquisition time are the estimates of the voxel activities. As an example of a classification task, a hypothesis stating that some region of interest (ROI) emitted at least or at most r-times the number of events in some other ROI is tested. The ROIs are specified by the user. The analysis described in this work provides new quantitative statistical measures that can be used in decision making in diagnostic imaging using emission tomography. (paper)

Data analysis in emission tomography using emission-count posteriors

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Sitek, Arkadiusz

2012-11-01

A novel approach to the analysis of emission tomography data using the posterior probability of the number of emissions per voxel (emission count) conditioned on acquired tomographic data is explored. The posterior is derived from the prior and the Poisson likelihood of the emission-count data by marginalizing voxel activities. Based on emission-count posteriors, examples of Bayesian analysis including estimation and classification tasks in emission tomography are provided. The application of the method to computer simulations of 2D tomography is demonstrated. In particular, the minimum-mean-square-error point estimator of the emission count is demonstrated. The process of finding this estimator can be considered as a tomographic image reconstruction technique since the estimates of the number of emissions per voxel divided by voxel sensitivities and acquisition time are the estimates of the voxel activities. As an example of a classification task, a hypothesis stating that some region of interest (ROI) emitted at least or at most r-times the number of events in some other ROI is tested. The ROIs are specified by the user. The analysis described in this work provides new quantitative statistical measures that can be used in decision making in diagnostic imaging using emission tomography.

MR imaging and positron emission tomography of cortical heterotopia

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Bairamian, D.; Di Chiro, G.; Theodore, W.H.; Holmes, M.D.; Dorwart, R.H.; Larson, S.M.

1985-11-01

Heterotopia of the gray matter is a developmental malformation in which ectopic cortex is found in the white matter of the brain. A case of a 33-year-old man with cortical heterotopia who had a lifelong history of seizures and psychomotor retardation is reported, including the results of cerebral CT, magnetic resonance imaging, and positron emission tomography using YF-2-deoxyglucose.

MR imaging and positron emission tomography of cortical heterotopia

International Nuclear Information System (INIS)

Bairamian, D.; Di Chiro, G.; Theodore, W.H.; Holmes, M.D.; Dorwart, R.H.; Larson, S.M.

1985-01-01

Heterotopia of the gray matter is a developmental malformation in which ectopic cortex is found in the white matter of the brain. A case of a 33-year-old man with cortical heterotopia who had a lifelong history of seizures and psychomotor retardation is reported, including the results of cerebral CT, magnetic resonance imaging, and positron emission tomography using 18 F-2-deoxyglucose

Positron emission tomography

International Nuclear Information System (INIS)

Yamamoto, Y.L.; Thompson, C.J.; Diksic, M.; Meyer, E.; Feindel, W.H.

1984-01-01

One of the most exciting new technologies introduced in the last 10 yr is positron emission tomography (PET). PET provides quantitative, three-dimensional images for the study of specific biochemical and physiological processes in the human body. This approach is analogous to quantitative in-vivo autoradiography but has the added advantage of permitting non-invasive in vivo studies. PET scanning requires a small cyclotron to produce short-lived positron emitting isotopes such as oxygen-15, carbon-11, nitrogen-13 and fluorine-18. Proper radiochemical facilities and advanced computer equipment are also needed. Most important, PET requires a multidisciplinary scientific team of physicists, radiochemists, mathematicians, biochemists and physicians. The most recent trends are reviewed in the imaging technology, radiochemistry, methodology and clinical applications of positron emission tomography. (author)

Computed tomography and three-dimensional imaging

International Nuclear Information System (INIS)

Harris, L.D.; Ritman, E.L.; Robb, R.A.

1987-01-01

Presented here is a brief introduction to two-, three-, and four-dimensional computed tomography. More detailed descriptions of the mathematics of reconstruction and of CT scanner operation are presented elsewhere. The complementary tomographic imaging methods of single-photon-emission tomography (SPECT) positron-emission tomography (PET), nuclear magnetic resonance (NMR) imaging, ulltrasound sector scanning, and ulltrasound computer-assisted tomography [UCAT] are only named here. Each imaging modality ''probes'' the body with a different energy form, yielding unique and useful information about tomographic sections through the body

A novel phantom design for emission tomography enabling scatter- and attenuation-''free'' single-photon emission tomography imaging

International Nuclear Information System (INIS)

Larsson, S.A.; Johansson, L.; Jonsson, C.; Pagani, M.; Jacobsson, H.

2000-01-01

A newly designed technique for experimental single-photon emission tomography (SPET) and positron emission tomography (PET) data acquisition with minor disturbing effects from scatter and attenuation has been developed. In principle, the method is based on discrete sampling of the radioactivity distribution in 3D objects by means of equidistant 2D planes. The starting point is a set of digitised 2D sections representing the radioactivity distribution of the 3D object. Having a radioactivity-related grey scale, the 2D images are printed on paper sheets using radioactive ink. The radioactive sheets can be shaped to the outline of the object and stacked into a 3D structure with air or some arbitrary dense material in between. For this work, equidistantly spaced transverse images of a uniform cylindrical phantom and of the digitised Hoffman rCBF phantom were selected and printed out on paper sheets. The uniform radioactivity sheets were imaged on the surface of a low-energy ultra-high-resolution collimator (4 mm full-width at half-maximum) of a three-headed SPET camera. The reproducibility was 0.7% and the uniformity was 1.2%. Each rCBF sheet, containing between 8.3 and 80 MBq of 99m TcO 4 - depending on size, was first imaged on the collimator and then stacked into a 3D structure with constant 12 mm air spacing between the slices. SPET was performed with the sheets perpendicular to the central axis of the camera. The total weight of the stacked rCBF phantom in air was 63 g, giving a scatter contribution comparable to that of a point source in air. The overall attenuation losses were <20%. A second SPET study was performed with 12-mm polystyrene plates in between the radioactive sheets. With polystyrene plates, the total phantom weight was 2300 g, giving a scatter and attenuation magnitude similar to that of a patient study. With the proposed technique, it is possible to obtain ''ideal'' experimental images (essentially built up by primary photons) for comparison with

Diagnostic performance of fluorodeoxyglucose positron emission tomography/magnetic resonance imaging fusion images of gynecological malignant tumors. Comparison with positron emission tomography/computed tomography

International Nuclear Information System (INIS)

Nakajo, Kazuya; Tatsumi, Mitsuaki; Inoue, Atsuo

2010-01-01

We compared the diagnostic accuracy of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and PET/magnetic resonance imaging (MRI) fusion images for gynecological malignancies. A total of 31 patients with gynecological malignancies were enrolled. FDG-PET images were fused to CT, T1- and T2-weighted images (T1WI, T2WI). PET-MRI fusion was performed semiautomatically. We performed three types of evaluation to demonstrate the usefulness of PET/MRI fusion images in comparison with that of inline PET/CT as follows: depiction of the uterus and the ovarian lesions on CT or MRI mapping images (first evaluation); additional information for lesion localization with PET and mapping images (second evaluation); and the image quality of fusion on interpretation (third evaluation). For the first evaluation, the score for T2WI (4.68±0.65) was significantly higher than that for CT (3.54±1.02) or T1WI (3.71±0.97) (P<0.01). For the second evaluation, the scores for the localization of FDG accumulation showing that T2WI (2.74±0.57) provided significantly more additional information for the identification of anatomical sites of FDG accumulation than did CT (2.06±0.68) or T1WI (2.23±0.61) (P<0.01). For the third evaluation, the three-point rating scale for the patient group as a whole demonstrated that PET/T2WI (2.72±0.54) localized the lesion significantly more convincingly than PET/CT (2.23±0.50) or PET/T1WI (2.29±0.53) (P<0.01). PET/T2WI fusion images are superior for the detection and localization of gynecological malignancies. (author)

Review of cardiovascular imaging in the journal of nuclear cardiology in 2015. Part 1 of 2: Plaque imaging, positron emission tomography, computed tomography, and magnetic resonance.

Science.gov (United States)

AlJaroudi, Wael A; Hage, Fadi G

2016-02-01

In 2015, many original articles pertaining to cardiovascular imaging with impressive quality were published in the Journal of Nuclear Cardiology. In a set of 2 articles, we provide an overview of these contributions to facilitate for the interested reader a quick review of the advancements that occurred in the field over this year. In this first article, we focus on arterial plaque imaging, cardiac positron emission tomography, computed tomography, and magnetic resonance imaging.

Lhermitte-Duclos disease presenting with positron emission tomography-magnetic resonance fusion imaging: a case report

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Calabria Ferdinando

2012-03-01

Full Text Available Abstract Introduction Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum is an extremely rare tumor. It is a slowly enlarging mass within the cerebellar cortex. The majority of cases are diagnosed in the third or fourth decade of life. Case presentation We report the case of a 37-year-old Caucasian woman who underwent positron emission tomography-computed tomography with fluorine-18-fluorodeoxyglucose for evaluation of a solitary lung node. No pathological uptake was detected in the solitary lung node but the positron emission tomography-computed tomography of her brain showed intense tracer uptake, suggestive of a malignant neoplasm, in a mass in her left cerebellar lobe. Our patient had experienced two years of occipital headache and movement disorder. Subsequently, magnetic resonance imaging was performed with contrast agent administration, showing a large subtentorial mass in her left cerebellar hemisphere, with compression and dislocation of the fourth ventricle. Metabolic data provided by positron emission tomography and morphological magnetic resonance imaging views were fused in post-processing, allowing a diagnosis of dysplastic gangliocytoma with increased glucose metabolism. Total resection of the tumor was performed and histological examination confirmed the diagnosis of Lhermitte-Duclos disease. Conclusions Our case indicates that increased uptake of fluorine-18-fluorodeoxyglucose may be misinterpreted as a neoplastic process in the evaluation of patients with Lhermitte-Duclos disease, but supports the usefulness of integrated positron emission tomography-magnetic resonance imaging in the exact pathophysiologic explanation of this disease and in making the correct diagnosis. However, an accurate physical examination and exact knowledge of clinical data is of the utmost importance.

Positron Emission Tomography: Current Challenges and Opportunities for Technological Advances in Clinical and Preclinical Imaging Systems

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Vaquero, Juan José; Kinahan, Paul

2017-01-01

Positron emission tomography (PET) imaging is based on detecting two time-coincident high-energy photons from the emission of a positron-emitting radioisotope. The physics of the emission, and the detection of the coincident photons, give PET imaging unique capabilities for both very high sensitivity and accurate estimation of the in vivo concentration of the radiotracer. PET imaging has been widely adopted as an important clinical modality for oncological, cardiovascular, and neurological applications. PET imaging has also become an important tool in preclinical studies, particularly for investigating murine models of disease and other small-animal models. However, there are several challenges to using PET imaging systems. These include the fundamental trade-offs between resolution and noise, the quantitative accuracy of the measurements, and integration with X-ray computed tomography and magnetic resonance imaging. In this article, we review how researchers and industry are addressing these challenges. PMID:26643024

Positron Emission Tomography: Current Challenges and Opportunities for Technological Advances in Clinical and Preclinical Imaging Systems.

Science.gov (United States)

Vaquero, Juan José; Kinahan, Paul

2015-01-01

Positron emission tomography (PET) imaging is based on detecting two time-coincident high-energy photons from the emission of a positron-emitting radioisotope. The physics of the emission, and the detection of the coincident photons, give PET imaging unique capabilities for both very high sensitivity and accurate estimation of the in vivo concentration of the radiotracer. PET imaging has been widely adopted as an important clinical modality for oncological, cardiovascular, and neurological applications. PET imaging has also become an important tool in preclinical studies, particularly for investigating murine models of disease and other small-animal models. However, there are several challenges to using PET imaging systems. These include the fundamental trade-offs between resolution and noise, the quantitative accuracy of the measurements, and integration with X-ray computed tomography and magnetic resonance imaging. In this article, we review how researchers and industry are addressing these challenges.

Positron emission tomography/computed tomography--imaging protocols, artifacts, and pitfalls.

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Bockisch, Andreas; Beyer, Thomas; Antoch, Gerald; Freudenberg, Lutz S; Kühl, Hilmar; Debatin, Jörg F; Müller, Stefan P

2004-01-01

There has been a longstanding interest in fused images of anatomical information, such as that provided by computed tomography (CT) or magnetic resonance imaging (MRI) systems, with biological information obtainable by positron emission tomography (PET). The near-simultaneous data acquisition in a fixed combination of a PET and a CT scanner in a combined PET/CT imaging system minimizes spatial and temporal mismatches between the modalities by eliminating the need to move the patient in between exams. In addition, using the fast CT scan for PET attenuation correction, the duration of the examination is significantly reduced compared to standalone PET imaging with standard rod-transmission sources. The main source of artifacts arises from the use of the CT-data for scatter and attenuation correction of the PET images. Today, CT reconstruction algorithms cannot account for the presence of metal implants, such as dental fillings or prostheses, properly, thus resulting in streak artifacts, which are propagated into the PET image by the attenuation correction. The transformation of attenuation coefficients at X-ray energies to those at 511 keV works well for soft tissues, bone, and air, but again is insufficient for dense CT contrast agents, such as iodine or barium. Finally, mismatches, for example, due to uncoordinated respiration result in incorrect attenuation-corrected PET images. These artifacts, however, can be minimized or avoided prospectively by careful acquisition protocol considerations. In doubt, the uncorrected images almost always allow discrimination between true and artificial finding. PET/CT has to be integrated into the diagnostic workflow for harvesting the full potential of the new modality. In particular, the diagnostic power of both, the CT and the PET within the combination must not be underestimated. By combining multiple diagnostic studies within a single examination, significant logistic advantages can be expected if the combined PET

Development of novel emission tomography system

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Fu, Geng

In recent years, small animals, such as mice and rats, have been widely used as subjects of study in biomedical research while molecular biology and imaging techniques open new opportunities to investigate disease model. With the help of medical imaging techniques, researchers can investigate underlying mechanisms inside the small animal, which are useful for both early diagnosis and treatment monitoring. Based on tracer principle single photon emission computed tomography (SPECT) has increased popularity in small animal imaging due to its higher spatial resolution and variety of single-photon emitting radionuclides. Since the image quality strongly depends on the detector properties, both scintillation and semiconductor detectors are under active investigation for high resolution X-ray and gamma ray photon detection. The desired detector properties include high intrinsic spatial resolution, high energy resolution, and high detection efficiency. In this thesis study, we have made extensive efforts to develop novel emission tomography system, and evaluate the use of both semiconductor and ultra-high resolution scintillation detectors for small animal imaging. This thesis work includes the following three areas. Firstly, we have developed a novel energy-resolved photon counting (ERPC) detector. With the benefits of high energy resolution, high spatial resolution, flexible detection area, and a wide dynamic range of 27--200keV, ERPC detector is well-suited for small animal SPECT applications. For prototype ERPC detector excellent imaging (˜350microm) and spectroscopic performance (4keV Co-57 122keV) has been demonstrated in preliminary study. Secondly, to further improve spatial resolution to hundred-micron level, an ultra-high resolution Intensified EMCCD (I-EMCCD) detector has been designed and evaluated. This detector consists of the newly developed electron multiplying CCD (EMCCD) sensor, columnar CsI(Tl) scintillator, and an electrostatic de-magnifier (DM) tube

Spectrum of fluorodeoxyglucose-positron emission tomography/computed tomography and magnetic resonance imaging findings of ovarian tumors.

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Kitajima, Kazuhiro; Ueno, Yoshiko; Maeda, Tetsuo; Murakami, Koji; Kaji, Yasushi; Kita, Masato; Suzuki, Kayo; Sugimura, Kazuro

2011-11-01

The purpose of this article is to review fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) and magnetic resonance imaging (MRI) findings in a variety of benign, malignant, and borderline malignant ovarian tumors. It is advantageous to become familiar with the wide variety of FDG-PET/CT findings of this entity. Benign ovarian tumors generally have faint uptake, whereas endometriomas, fibromas, and teratomas show mild to moderate uptake. Malignant ovarian tumors generally have intense uptake, whereas tumors with a small solid component often show minimal uptake.

Quantitative single-photon emission tomography for cerebral flow and receptor distribution imaging

International Nuclear Information System (INIS)

Budinger, T.F.

1985-01-01

Recently there has been renewed interest in single-photon emission tomography for two major reasons. First, correction methods have been devised for attenuation compensation, nonuniform resolution, and scattered radiation. Second, new radiopharmaceuticals with 1-5% uptake in the brain provide adequate statistics for quantitative imaging of flow using properly designed single-photon tomographic instruments. The lack of commercially available instruments designed specifically to optimize sensitivity for a resolution finer than 15 mm full width at half maximum (FWHM) seems now to be the major deterrent to the widespread use of single-photon emission tomography. But it appears now that some development in this respect also might lead to a widespread renewed interest in single-photon tomography of the brain. Major activities of the past few years can be placed in three distinct categories of instrumentation and methodology

The role of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in resectable pancreatic cancer.

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Crippa, Stefano; Salgarello, Matteo; Laiti, Silvia; Partelli, Stefano; Castelli, Paola; Spinelli, Antonello E; Tamburrino, Domenico; Zamboni, Giuseppe; Falconi, Massimo

2014-08-01

The role of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in pancreatic ductal adenocarcinoma is debated. We retrospectively assessed the value of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in addition to conventional imaging as a staging modality in pancreatic cancer. (18)Fluoro-deoxyglucose positron emission tomography/computed tomography was performed in 72 patients with resectable pancreatic carcinoma after multi-detector computed tomography positron emission tomography was considered positive for a maximum standardized uptake value >3. Overall, 21% of patients had a maximum standardized uptake value ≤ 3, and 60% of those had undergone neoadjuvant treatment (P=0.0001). Furthermore, 11% of patients were spared unwarranted surgery since positron emission tomography/computed tomography detected metastatic disease. All liver metastases were subsequently identified with contrast-enhanced ultrasound. Sensitivity and specificity of positron emission tomography/computed tomography for distant metastases were 78% and 100%. The median CA19.9 concentration was 48.8 U/mL for the entire cohort and 292 U/mL for metastatic patients (P=0.112). The widespread application of (18)fluoro-deoxyglucose positron emission tomography/computed tomography in patients with resectable pancreatic carcinoma seems not justified. It should be considered in selected patients at higher risk of metastatic disease (i.e. CA19.9>200 U/mL) after undergoing other imaging tests. Neoadjuvant treatment is significantly associated with low metabolic activity, limiting the value of positron emission tomography in this setting. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

An introduction to emission computed tomography

International Nuclear Information System (INIS)

Williams, E.D.

1985-01-01

This report includes salient features of the theory and an examination of practical considerations for someone who is using or introducing tomography, selecting equipment for it or wishing to develop a clinical application. Emphasis is on gamma camera tomography. The subject is dealt with under the following headings: emission computed and gamma camera tomography and the relationship to other medical imaging techniques, the tomographic reconstruction technique theory, rotating gamma camera tomography, attenuation correction and quantitative reconstruction, other single photon tomographic techniques, positron tomography, image display, clinical application of single photon and positron tomography, and commercial systems for SPECT. Substantial bibliography. (U.K.)

Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging in Patients With Carcinoma of the Nasopharynx: Diagnostic Accuracy and Impact on Clinical Management

International Nuclear Information System (INIS)

Gordin, Arie; Golz, Avishay; Daitzchman, Marcello; Keidar, Zohar; Bar-Shalom, Rachel; Kuten, Abraham; Israel, Ora

2007-01-01

Purpose: To assess the value of 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma as compared with PET and conventional imaging (CI) alone, and to assess the impact of PET/CT on further clinical management. Methods and Materials: Thirty-three patients with nasopharyngeal carcinoma had 45 PET/CT examinations. The study was a retrospective analysis. Changes in patient care resulting from the PET/CT studies were recorded. Results: Positron emission tomography/computed tomography had sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 92%, 90%, 90%, 90%, and 91%, respectively, as compared with 92%, 65%, 76%, 86%, and 80% for PET and 92%, 15%, 60%, 60%, and 60% for CI. Imaging with PET/CT altered further management of 19 patients (57%). Imaging with PET/CT eliminated the need for previously planned diagnostic procedures in 11 patients, induced a change in the planned therapeutic approach in 5 patients, and guided biopsy to a specific metabolically active area inside an edematous region in 3 patients, thus decreasing the chances for tissue sampling errors and avoiding damage to nonmalignant tissue. Conclusions: In cancer of the nasopharynx, the diagnostic performance of PET/CT is better than that of stand-alone PET or CI. Positron emission tomography/computed tomography had a major impact on further clinical management in 57% of patients

Monte-Carlo simulations and image reconstruction for novel imaging scenarios in emission tomography

International Nuclear Information System (INIS)

Gillam, John E.; Rafecas, Magdalena

2016-01-01

Emission imaging incorporates both the development of dedicated devices for data acquisition as well as algorithms for recovering images from that data. Emission tomography is an indirect approach to imaging. The effect of device modification on the final image can be understood through both the way in which data are gathered, using simulation, and the way in which the image is formed from that data, or image reconstruction. When developing novel devices, systems and imaging tasks, accurate simulation and image reconstruction allow performance to be estimated, and in some cases optimized, using computational methods before or during the process of physical construction. However, there are a vast range of approaches, algorithms and pre-existing computational tools that can be exploited and the choices made will affect the accuracy of the in silico results and quality of the reconstructed images. On the one hand, should important physical effects be neglected in either the simulation or reconstruction steps, specific enhancements provided by novel devices may not be represented in the results. On the other hand, over-modeling of device characteristics in either step leads to large computational overheads that can confound timely results. Here, a range of simulation methodologies and toolkits are discussed, as well as reconstruction algorithms that may be employed in emission imaging. The relative advantages and disadvantages of a range of options are highlighted using specific examples from current research scenarios.

Monte-Carlo simulations and image reconstruction for novel imaging scenarios in emission tomography

Energy Technology Data Exchange (ETDEWEB)

Gillam, John E. [The University of Sydney, Faculty of Health Sciences and The Brain and Mind Centre, Camperdown (Australia); Rafecas, Magdalena, E-mail: rafecas@imt.uni-luebeck.de [University of Lubeck, Institute of Medical Engineering, Ratzeburger Allee 160, 23538 Lübeck (Germany)

2016-02-11

Emission imaging incorporates both the development of dedicated devices for data acquisition as well as algorithms for recovering images from that data. Emission tomography is an indirect approach to imaging. The effect of device modification on the final image can be understood through both the way in which data are gathered, using simulation, and the way in which the image is formed from that data, or image reconstruction. When developing novel devices, systems and imaging tasks, accurate simulation and image reconstruction allow performance to be estimated, and in some cases optimized, using computational methods before or during the process of physical construction. However, there are a vast range of approaches, algorithms and pre-existing computational tools that can be exploited and the choices made will affect the accuracy of the in silico results and quality of the reconstructed images. On the one hand, should important physical effects be neglected in either the simulation or reconstruction steps, specific enhancements provided by novel devices may not be represented in the results. On the other hand, over-modeling of device characteristics in either step leads to large computational overheads that can confound timely results. Here, a range of simulation methodologies and toolkits are discussed, as well as reconstruction algorithms that may be employed in emission imaging. The relative advantages and disadvantages of a range of options are highlighted using specific examples from current research scenarios.

Positron emission tomography of the heart

International Nuclear Information System (INIS)

Budinger, T.F.; Yano, Y.; Mathis, C.A.; Moyer, B.R.; Huesman, R.H.; Derenzo, S.E.

1983-01-01

Positron emission tomography (PET) offers the opportunity to noninvasively measure heart muscle blood perfusion, oxygen utilization, metabolism of fatty acids, sugars and amino acids. This paper reviews physiological principles which are basic to PET instrumentation for imaging the heart and gives examples of the application of positron emission tomography for measuring myocardial flow and metabolism. 33 references, 11 figures, 1 table

Functional cardiac imaging: positron emission tomography

International Nuclear Information System (INIS)

Mullani, N.A.; Gould, K.L.

1984-01-01

Dynamic cardiovascular imaging plays a vital role in the diagnosis and treatment of cardiac disease by providing information about the function of the heart. During the past 30 years, cardiovascular imaging has evolved from the simple chest x-ray and fluoroscopy to such sophisticated techniques as invasive cardiac angiography and cinearteriography and, more recently, to noninvasive cardiac CT scanning, nuclear magnetic resonance, and positron emission tomography, which reflect more complex physiologic functions. As research tools, CT, NMR, and PET provide quantitative information on global as well as regional ventricular function, coronary artery stenosis, myocardial perfusion, glucose and fatty acid metabolism, or oxygen utilization, with little discomfort or risk to the patient. As imaging modalities become more sophisticated and more oriented toward clinical application, the prospect of routinely obtaining such functional information about the heart is becoming realistic. However, these advances are double-edged in that the interpretation of functional data is more complex than that of the anatomic imaging familiar to most physicians. They will require an enhanced understanding of the physiologic and biochemical processes, as well as of the instrumentation and techniques for analyzing the data. Of the new imaging modalities that provide functional information about the heart, PET is the most useful because it quantitates the regional distribution of radionuclides in vivo. Clinical applications, interpretation of data, and the impact of PET on our understanding of cardiac pathophysiology are discussed. 5 figures

Images to visualize the brain. PET: Positron Emission Tomography

International Nuclear Information System (INIS)

1992-01-01

Diagnosis instrument and research tool, Positron Emission Tomography permits advanced technological developments on positron camera, on molecule labelling and principally on very complex 3D image processing. Cyceron Centre in Caen-France works on brain diseases and try to understand the mechanism of observed troubles and to assess the treatment efficiency with PET. Service Hospitalier Frederic Joliot of CEA-France establishes a mapping of cognitive functions in PET as vision areas, anxiety regions, brain organization of language, different attention forms, voluntary actions and motor functions

Positron emission tomography

International Nuclear Information System (INIS)

Chandrasekhar, Preethi; Himabindu, Pucha

2000-01-01

Positron Emission Tomography (PET) is a non-invasive nuclear imaging technique used to study different molecular pathways and anatomical structures. PET has found extensive applications in various fields of medicine viz. cardiology, oncology, psychiatry/psychology, neuro science and pulmonology. This study paper basically deals with the physics, chemistry and biology behind the PET technique. It discusses the methodology for generation of the radiotracers responsible for emission of positrons and the annihilation and detection techniques. (author)

Positron-emission tomography imaging of long-term shape recognition challenges

OpenAIRE

Rosier, A.; Cornette, L.; Dupont, P.; Bormans, G.; Michiels, J.; Mortelmans, L.; Orban, G. A.

1997-01-01

Long-term visual memory performance was impaired by two types of challenges: a diazepam challenge on acquisition and a sensory challenge on recognition. Using positron-emission tomography regional cerebral blood flow imaging, we studied the effect of these challenges on regional brain activation during the delayed recognition of abstract visual shapes as compared with a baseline fixation task. Both challenges induced a significant decrease in differential activation in the left fusiform gyrus...

Efficacy of 3D-positron emission tomography/computed tomography for upper abdomen.

Science.gov (United States)

Murakami, Koji; Nakahara, Tadaki

2014-04-01

Recent advancement in computed tomography (CT) enables us to obtain high spatial resolution image and made it possible to construct extensive high-definition three-dimensional (3D) images. But a lack of contrast resolution in CT alone is still remained problem. Meanwhile, as fluorodeoxyglucose-positron emission tomography (PET) can visualize tumors in high contrast, we can create 3D images fusing the accumulation in tumors on PET/CT images. Such images can play the role of a "map of body" which makes it easy to understand the anatomical information before surgery. We also try to evaluate segmental liver function by using PET/CT fusion images. By using (11) C-methionine PET/contrast-enhanced CT, superior image quality compared to single photon emission computed tomography/CT can be obtained. CT, especially with contrast enhancement for obtaining anatomical imaging information plus PET for obtaining functional imaging information is a highly compatible combination, and adding these two types information will further increase clinical usefulness. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Applications of X-ray Computed Tomography and Emission Computed Tomography

International Nuclear Information System (INIS)

Seletchi, Emilia Dana; Sutac, Victor

2005-01-01

Computed Tomography is a non-destructive imaging method that allows visualization of internal features within non-transparent objects such as sedimentary rocks. Filtering techniques have been applied to circumvent the artifacts and achieve high-quality images for quantitative analysis. High-resolution X-ray computed tomography (HRXCT) can be used to identify the position of the growth axis in speleothems by detecting subtle changes in calcite density between growth bands. HRXCT imagery reveals the three-dimensional variability of coral banding providing information on coral growth and climate over the past several centuries. The Nuclear Medicine imaging technique uses a radioactive tracer, several radiation detectors, and sophisticated computer technologies to understand the biochemical basis of normal and abnormal functions within the brain. The goal of Emission Computed Tomography (ECT) is to accurately determine the three-dimensional radioactivity distribution resulting from the radiopharmaceutical uptake inside the patient instead of the attenuation coefficient distribution from different tissues as obtained from X-ray Computer Tomography. ECT is a very useful tool for investigating the cognitive functions. Because of the low radiation doses associated with Positron Emission Tomography (PET), this technique has been applied in clinical research, allowing the direct study of human neurological diseases. (authors)

Positron emission tomography/computed tomography surveillance in patients with Hodgkin lymphoma in first remission has a low positive predictive value and high costs.

Science.gov (United States)

El-Galaly, Tarec Christoffer; Mylam, Karen Juul; Brown, Peter; Specht, Lena; Christiansen, Ilse; Munksgaard, Lars; Johnsen, Hans Erik; Loft, Annika; Bukh, Anne; Iyer, Victor; Nielsen, Anne Lerberg; Hutchings, Martin

2012-06-01

The value of performing post-therapy routine surveillance imaging in patients with Hodgkin lymphoma is controversial. This study evaluates the utility of positron emission tomography/computed tomography using 2-[18F]fluoro-2-deoxyglucose for this purpose and in situations with suspected lymphoma relapse. We conducted a multicenter retrospective study. Patients with newly diagnosed Hodgkin lymphoma achieving at least a partial remission on first-line therapy were eligible if they received positron emission tomography/computed tomography surveillance during follow-up. Two types of imaging surveillance were analyzed: "routine" when patients showed no signs of relapse at referral to positron emission tomography/computed tomography, and "clinically indicated" when recurrence was suspected. A total of 211 routine and 88 clinically indicated positron emission tomography/computed tomography studies were performed in 161 patients. In ten of 22 patients with recurrence of Hodgkin lymphoma, routine imaging surveillance was the primary tool for the diagnosis of the relapse. Extranodal disease, interim positron emission tomography-positive lesions and positron emission tomography activity at response evaluation were all associated with a positron emission tomography/computed tomography-diagnosed preclinical relapse. The true positive rates of routine and clinically indicated imaging were 5% and 13%, respectively (P = 0.02). The overall positive predictive value and negative predictive value of positron emission tomography/computed tomography were 28% and 100%, respectively. The estimated cost per routine imaging diagnosed relapse was US$ 50,778. Negative positron emission tomography/computed tomography reliably rules out a relapse. The high false positive rate is, however, an important limitation and a confirmatory biopsy is mandatory for the diagnosis of a relapse. With no proven survival benefit for patients with a pre-clinically diagnosed relapse, the high costs and low

Incidental head and neck findings on 18F-fluoro-deoxy-glucose positron emission tomography computed tomography.

Science.gov (United States)

Williams, S P; Kinshuck, A J; Williams, C; Dwivedi, R; Wieshmann, H; Jones, T M

2015-09-01

The overlapping risk factors for lung and head and neck cancer present a definite risk of synchronous malignant pathology. This is the first study to specifically review incidental positron emission tomography computed tomography findings in the head and neck region in lung carcinoma patients. A retrospective review was performed of all lung cancer patients who underwent positron emission tomography computed tomography imaging over a five-year period (January 2008 - December 2012), identified from the Liverpool thoracic multidisciplinary team database. Six hundred and nine patients underwent positron emission tomography computed tomography imaging over this period. In 76 (12.5 per cent) scans, incidental regions of avid 18F-fluoro-deoxy-glucose uptake were reported in the head and neck region. In the 28 patients who were fully investigated, there were 4 incidental findings of malignancy. In lung cancer patients undergoing investigative positron emission tomography computed tomography scanning, a significant number will also present with areas of clinically significant 18F-fluoro-deoxy-glucose uptake in the head and neck region. Of these, at least 5 per cent may have an undiagnosed malignancy.

An analysis of true- and false-positive results of vocal fold uptake in positron emission tomography-computed tomography imaging.

Science.gov (United States)

Seymour, N; Burkill, G; Harries, M

2018-03-01

Positron emission tomography-computed tomography with fluorine-18 fluorodeoxy-D-glucose has a major role in the investigation of head and neck cancers. Fluorine-18 fluorodeoxy-D-glucose is not a tumour-specific tracer and can also accumulate in benign pathology. Therefore, positron emission tomography-computed tomography scan interpretation difficulties are common in the head and neck, which can produce false-positive results. This study aimed to investigate patients detected as having abnormal vocal fold uptake on fluorine-18 fluorodeoxy-D-glucose positron emission tomography-computed tomography. Positron emission tomography-computed tomography scans were identified over a 15-month period where reports contained evidence of unilateral vocal fold uptake or vocal fold pathology. Patients' notes and laryngoscopy results were analysed. Forty-six patients were identified as having abnormal vocal fold uptake on positron emission tomography-computed tomography. Twenty-three patients underwent positron emission tomography-computed tomography and flexible laryngoscopy: 61 per cent of patients had true-positive positron emission tomography-computed tomography scans and 39 per cent had false-positive scan results. Most patients referred to ENT for abnormal findings on positron emission tomography-computed tomography scans had true-positive findings. Asymmetrical fluorine-18 fluorodeoxy-D-glucose uptake should raise suspicion of vocal fold pathology, accepting a false-positive rate of approximately 40 per cent.

Longitudinal emission tomography of thyroid and heart

International Nuclear Information System (INIS)

Giessen, J.W. van.

1986-01-01

In this thesis three devices are discussed for longitudinal emission tomography, one of which has been developed for myocardial imaging and the other two for thyroid imaging. Longitudinal emission tomography is a technique which enables three-dimensional reconstruction of the radioactivity distribution within an organ from two-dimensional distributions on a detector surface. In Ch. 1 a general survey is given of the clinical environment in which the devices will be used. Ch. 2 discusses a well-known technique for myocardial imaging: seven-pinhole tomography. In Ch. 3 this technique is applied to imaging of the thyroid. Three different reconstruction methods have been applied to the data collected with the system (from phantoms as well as from patients) and the results have been evaluated. Ch. 4 discusses simulation studies which were carried out in order to investigate the potentialities of a time-coded aperture (TCA) system designed for thyroid tomography. In Ch. 5 a prototype is tested of the time coded aperture in a clinical environment. The last chapter presents a comparison between the (thyroid) 7P collimator and the TCA device. (Auth.)

First results of genetic algorithm application in ML image reconstruction in emission tomography

International Nuclear Information System (INIS)

Smolik, W.

1999-01-01

This paper concerns application of genetic algorithm in maximum likelihood image reconstruction in emission tomography. The example of genetic algorithm for image reconstruction is presented. The genetic algorithm was based on the typical genetic scheme modified due to the nature of solved problem. The convergence of algorithm was examined. The different adaption functions, selection and crossover methods were verified. The algorithm was tested on simulated SPECT data. The obtained results of image reconstruction are discussed. (author)

Small animal positron emission tomography imaging and in vivo studies of atherosclerosis

DEFF Research Database (Denmark)

Hag, Anne Mette Fisker; Ripa, Rasmus Sejersten; Pedersen, Sune Folke

2013-01-01

Atherosclerosis is a growing health challenge globally, and despite our knowledge of the disease has increased over the last couple of decades, many unanswered questions remain. As molecular imaging can be used to visualize, characterize and measure biological processes at the molecular and cellu...... knowledge obtained from in vivo positron emission tomography studies of atherosclerosis performed in small animals....

Prospective, blinded trial of whole-body magnetic resonance imaging versus computed tomography positron emission tomography in staging primary and recurrent cancer of the head and neck.

LENUS (Irish Health Repository)

O'Neill, J P

2012-02-01

OBJECTIVES: To compare the use of computed tomography - positron emission tomography and whole-body magnetic resonance imaging for the staging of head and neck cancer. PATIENTS AND METHODS: From January to July 2009, 15 consecutive head and neck cancer patients (11 men and four women; mean age 59 years; age range 19 to 81 years) underwent computed tomography - positron emission tomography and whole-body magnetic resonance imaging for pre-therapeutic evaluation. All scans were staged, as per the American Joint Committee on Cancer tumour-node-metastasis classification, by two blinded consultant radiologists, in two sittings. Diagnoses were confirmed by histopathological examination of endoscopic biopsies, and in some cases whole surgical specimens. RESULTS: Tumour staging showed a 74 per cent concordance, node staging an 80 per cent concordance and metastasis staging a 100 per cent concordance, comparing the two imaging modalities. CONCLUSION: This study found radiological staging discordance between the two imaging modalities. Whole-body magnetic resonance imaging is an emerging staging modality with superior visualisation of metastatic disease, which does not require exposure to ionising radiation.

Utility of positron emission tomography-magnetic resonance imaging in musculoskeletal imaging

Institute of Scientific and Technical Information of China (English)

Ammar A Chaudhry; Maryam Gul; Elaine Gould; Mathew Teng; Kevin Baker; Robert Matthews

2016-01-01

Differentiation between neoplastic and nonneoplastic conditions magnetic resonance imaging(MRI) has established itself as one of the key clinical tools in evaluation of musculoskeletal pathology. However, MRI still has several key limitations which require supplemental information from additional modalities to complete evaluation of various disorders. This has led to the development hybrid positron emission tomography(PET)-MRI which is rapidly evolving to address key clinical questions by using the morphological strengths of MRI and functional information of PET imaging. In this article, we aim to review physical principles and techniques of PET-MRI and discuss clinical utility of functional information obtained from PET imaging and structural information obtained from MRI imaging for the evaluation of musculoskeletal pathology. More specifically, this review highlights the role of PET-MRI in musculoskeletal oncology including initial diagnosis and staging, treatment planning and posttreatment follow-up. Also we will review utility of PET-MRI in evaluating musculoskeletal infections(especially in the immunocompromised and diabetics) and inflammatory condition. Additionally, common pitfalls of PET-MRI will be addressed.

Fluorodeoxyglucose-positron emission tomography/computed tomography imaging features of colloid adenocarcinoma of the lung: a case report.

Science.gov (United States)

Wang, ZhenGuang; Yu, MingMing; Chen, YueHua; Kong, Yan

2017-07-27

Colloid adenocarcinoma of the lung is a rare subtype of variants of invasive adenocarcinomas. We report the appearance of this unusual entity on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography. A 60-year-old man of Chinese Han nationality coughed with a little white sputum for 1 month. Chest computed tomography showed multiple bilateral subpleural nodules and plaques accompanied by air bronchograms, which were most concentrated in the lower lobe of his right lung. Positron emission tomography indicated increased radioactivity uptake with a maximum standardized uptake value of 3.5. Positron emission tomography/computed tomography showed a soft tissue density lesion in his left adrenal gland with a maximum standardized uptake value of 4.1. The positron emission tomography/computed tomography appearance suggested a primary colloid adenocarcinoma in the lower lobe of his right lung accompanied by intrapulmonary and left adrenal gland metastases. The diagnostic rate of colloid adenocarcinoma can be increased by combining the anatomic and metabolic information of lesions. The advantage of positron emission tomography/computed tomography in the diagnosis of colloid adenocarcinoma, as with other cancers, is the ability to locate extrapulmonary disease, facilitating clinical staging.

Biological imaging in radiation therapy: role of positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Nestle, Ursula; Hentschel, Michael; Grosu, Anca-Ligia [Departments of Radiation Oncology, University of Freiburg, Robert Koch Str. 3, 79106 Freiburg (Germany); Weber, Wolfgang [Nuclear Medicine, University of Freiburg, Robert Koch Str. 3, 79106 Freiburg (Germany)], E-mail: ursula.nestle@uniklinik-freiburg.de

2009-01-07

In radiation therapy (RT), staging, treatment planning, monitoring and evaluation of response are traditionally based on computed tomography (CT) and magnetic resonance imaging (MRI). These radiological investigations have the significant advantage to show the anatomy with a high resolution, being also called anatomical imaging. In recent years, so called biological imaging methods which visualize metabolic pathways have been developed. These methods offer complementary imaging of various aspects of tumour biology. To date, the most prominent biological imaging system in use is positron emission tomography (PET), whose diagnostic properties have clinically been evaluated for years. The aim of this review is to discuss the valences and implications of PET in RT. We will focus our evaluation on the following topics: the role of biological imaging for tumour tissue detection/delineation of the gross tumour volume (GTV) and for the visualization of heterogeneous tumour biology. We will discuss the role of fluorodeoxyglucose-PET in lung and head and neck cancer and the impact of amino acids (AA)-PET in target volume delineation of brain gliomas. Furthermore, we summarize the data of the literature about tumour hypoxia and proliferation visualized by PET. We conclude that, regarding treatment planning in radiotherapy, PET offers advantages in terms of tumour delineation and the description of biological processes. However, to define the real impact of biological imaging on clinical outcome after radiotherapy, further experimental, clinical and cost/benefit analyses are required. (topical review)

Biological imaging in radiation therapy: role of positron emission tomography.

Science.gov (United States)

Nestle, Ursula; Weber, Wolfgang; Hentschel, Michael; Grosu, Anca-Ligia

2009-01-07

In radiation therapy (RT), staging, treatment planning, monitoring and evaluation of response are traditionally based on computed tomography (CT) and magnetic resonance imaging (MRI). These radiological investigations have the significant advantage to show the anatomy with a high resolution, being also called anatomical imaging. In recent years, so called biological imaging methods which visualize metabolic pathways have been developed. These methods offer complementary imaging of various aspects of tumour biology. To date, the most prominent biological imaging system in use is positron emission tomography (PET), whose diagnostic properties have clinically been evaluated for years. The aim of this review is to discuss the valences and implications of PET in RT. We will focus our evaluation on the following topics: the role of biological imaging for tumour tissue detection/delineation of the gross tumour volume (GTV) and for the visualization of heterogeneous tumour biology. We will discuss the role of fluorodeoxyglucose-PET in lung and head and neck cancer and the impact of amino acids (AA)-PET in target volume delineation of brain gliomas. Furthermore, we summarize the data of the literature about tumour hypoxia and proliferation visualized by PET. We conclude that, regarding treatment planning in radiotherapy, PET offers advantages in terms of tumour delineation and the description of biological processes. However, to define the real impact of biological imaging on clinical outcome after radiotherapy, further experimental, clinical and cost/benefit analyses are required.

Physics and instrumentation of emission computed tomography

International Nuclear Information System (INIS)

Links, J.M.

1986-01-01

Transverse emission computed tomography can be divided into two distinct classes: single photon emission computed tomography (SPECT) and positron emission tomography (PET). SPECT is usually accomplished with specially-adapted scintillation cameras, although dedicated SPECT scanners are available. The special SPECT cameras are standard cameras which are mounted on gantries that allow 360 degree rotation around the long axis of the head or body. The camera stops at a number of angles around the body (usually 64-128), acquiring a ''projection'' image at each stop. The data from these projections are used to reconstruct transverse images with a standard ''filtered back-projection'' algorithm, identical to that used in transmission CT. Because the scintillation camera acquires two-dimensional images, a simple 360 degree rotation around the patient results in the acquisition of data for a number of contiguous transverse slices. These slices, once reconstructed, can be ''stacked'' in computer memory, and orthogonal coronal and sagittal slices produced. Additionally, reorienting algorithms allow the generation of slices that are oblique to the long axis of the body

Imaging spectrum and pitfalls of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with tuberculosis.

Science.gov (United States)

Ito, Kimiteru; Morooka, Miyako; Minamimoto, Ryogo; Miyata, Yoko; Okasaki, Momoko; Kubota, Kazuo

2013-08-01

Mycobacterium tuberculosis (TB) is one of the most prominant diseases frequently causing false positive lesions in oncologic surveys using (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), since TB granulomas are composed of activated macrophages and lymphocytes with high affinity for glucose. These pitfalls of (18)F-FDG PET/CT are important for radiologists. Being familiar with (18)F-FDG images of TB could assist in preventing unfavorable clinical results based on misdiagnoses. In addition, (18)F-FDG PET/CT has the advantage of being able to screen the whole body, and can clearly detect harboring TB lesions as high uptake foci. This article details the spectrum and pitfalls of (18)F-FDG PET/CT imaging in TB.

F-18-fluorodeoxyglucose-positron emission tomography in colorectal cancer

International Nuclear Information System (INIS)

Joerg, L.; Langsteger, W.

2002-01-01

Whole-body positron emission tomography (PET) with the radiolabeled glucose analog F-18-fluorodeoxyglucose (F-18-FDG) is a sensitive diagnostic tool that images tumors based on increased uptake of glucose. Several recent publications have shown that F-18-fluorodeoxyglucose-positron emission tomography is more sensitive than computed-tomography (CT) in detecting colorectal cancer. In patients with increasing CEA (carcinoembryonic antigen) and no evidence of recurrent disease on CT F-18-fluorodeoxyglucose-positron emission tomography often detects recurrent cancer. In all, patient management seems to be changed in about 25 % of patients who undergo F-18-fluorodeoxyglucose-positron emission tomography in addition to standard staging procedure. Limited reports to date on both chemotherapy and radiotherapy support the role of F-18-fluorodeoxyglucose-positron emission tomography in assessing treatment response. Also regarding preoperative staging of primary colorectal cancer the literature is very limited. (author)

Principles of medical imaging with emphasis on tomography

Energy Technology Data Exchange (ETDEWEB)

Kouris, K [Institute of Nuclear Medicine, University College, London Medical School, Mortimer Street, London W1N 8AA (United Kingdom)

1994-12-31

Medical imaging with ionizing and non-ionizing radiations belongs to the class of problems known as indirect sensing. This article is concerned with imaging methods known as image reconstruction from projections or computerized tomography. A brief comparative study of the theory is presented. Depending on the nature and modes of propagation of the employed radiation, methods are discussed either under transmission tomography (with gamma rays and X rays) or emission tomography (with gamma rays and positrons). Magnetic resonance Imaging (MRI) is described as resonant absorption and re-emission of radiofrequency energy. (author). 6 refs, 1 fig.

Conditional probability distribution associated to the E-M image reconstruction algorithm for neutron stimulated emission tomography

International Nuclear Information System (INIS)

Viana, R.S.; Yoriyaz, H.; Santos, A.

2011-01-01

The Expectation-Maximization (E-M) algorithm is an iterative computational method for maximum likelihood (M-L) estimates, useful in a variety of incomplete-data problems. Due to its stochastic nature, one of the most relevant applications of E-M algorithm is the reconstruction of emission tomography images. In this paper, the statistical formulation of the E-M algorithm was applied to the in vivo spectrographic imaging of stable isotopes called Neutron Stimulated Emission Computed Tomography (NSECT). In the process of E-M algorithm iteration, the conditional probability distribution plays a very important role to achieve high quality image. This present work proposes an alternative methodology for the generation of the conditional probability distribution associated to the E-M reconstruction algorithm, using the Monte Carlo code MCNP5 and with the application of the reciprocity theorem. (author)

Conditional probability distribution associated to the E-M image reconstruction algorithm for neutron stimulated emission tomography

Energy Technology Data Exchange (ETDEWEB)

Viana, R.S.; Yoriyaz, H.; Santos, A., E-mail: rodrigossviana@gmail.com, E-mail: hyoriyaz@ipen.br, E-mail: asantos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

The Expectation-Maximization (E-M) algorithm is an iterative computational method for maximum likelihood (M-L) estimates, useful in a variety of incomplete-data problems. Due to its stochastic nature, one of the most relevant applications of E-M algorithm is the reconstruction of emission tomography images. In this paper, the statistical formulation of the E-M algorithm was applied to the in vivo spectrographic imaging of stable isotopes called Neutron Stimulated Emission Computed Tomography (NSECT). In the process of E-M algorithm iteration, the conditional probability distribution plays a very important role to achieve high quality image. This present work proposes an alternative methodology for the generation of the conditional probability distribution associated to the E-M reconstruction algorithm, using the Monte Carlo code MCNP5 and with the application of the reciprocity theorem. (author)

Imaging in hematology. Part 2: Computed tomography, magnetic resonance imaging and nuclear imaging

International Nuclear Information System (INIS)

Zhechev, Y.

2003-01-01

A dramatic increase of the role of imaging in diagnosis of blood diseases occurred with the development of computed tomography (CT) and magnetic resonance imaging (MRI). At present CT of the chest, abdomen, and pelvis is routinely employed in diagnostic and staging evaluation. The bone marrow may be imaged by one of several methods, including scintigraphy, CT and MRI. Nuclear imaging at diagnosis can clarify findings of uncertain significance on conventional staging and may be very useful in the setting of large masses to follow responses to therapy nad to evaluate the residual tumor in a large mass that has responded to treatment. Recent developments such as helical CT, single proton emission computed tomography (SPECT) and positron-emission tomography (PET) have continued to advance diagnosis and therapy

Single-photon emission tomography and cerebral blood flow

International Nuclear Information System (INIS)

Celsis, P.; Chan, M.; Marc-Vergnes, J.P.; Sveinsdottir, E.; Goldman, T.G.; Henriksen, L.; Paulson, O.B.; Stokely, E.M.; Lassen, N.A.

1982-01-01

This paper illustrates the capabilities of single-photon emission tomography in imaging local cerebral blood flows in man. The results purport the conclusion that a fairly good improvement has been achieved when compared to stationary detectors and that single-photon emission tomography is a well-suited tool for studying cerebral hemodynamics, especially within the framework of clinical studies [fr

Enhancement of positron emission tomography-computed tomography image quality using the principle of stochastic resonance

International Nuclear Information System (INIS)

Pandey, Anil Kumar; Sharma, Sanjay Kumar; Sharma, Punit; Singh, Harmandeep; Patel, Chetan; Sarkar, Kaushik; Kumar, Rakesh; Bal, Chandra Sekhar

2014-01-01

Acquisition of higher counts improves visual perception of positron emission tomography-computed tomography (PET-CT) image. Larger radiopharmaceutical doses (implies more radiation dose) are administered to acquire this count in a short time period. However, diagnostic information does not increase after a certain threshold of counts. This study was conducted to develop a post processing method based on principle of “stochastic resonance” to improve visual perception of the PET-CT image having a required threshold counts. PET-CT images (JPEG file format) with low, medium, and high counts in the image were included in this study. The image was corrupted with the addition of Poisson noise. The amplitude of the Poisson noise was adjusted by dividing each pixel by a constant 1, 2, 4, 8, 16, and 32. The best amplitude of the noise that gave best images quality was selected based on high value of entropy of the output image, high value of structural similarity index and feature similarity index. Visual perception of the image was evaluated by two nuclear medicine physicians. The variation in structural and feature similarity of the image was not appreciable visually, but statistically images deteriorated as the noise amplitude increases although maintaining structural (above 70%) and feature (above 80%) similarity of input images in all cases. We obtained the best image quality at noise amplitude “4” in which 88% structural and 95% feature similarity of the input images was retained. This method of stochastic resonance can be used to improve the visual perception of the PET-CT image. This can indirectly lead to reduction of radiation dose

Quantification in single photon emission computed tomography (SPECT)

International Nuclear Information System (INIS)

Buvat, Irene

2005-01-01

The objective of this lecture is to understand the possibilities and limitations of the quantitative analysis of single photon emission computed tomography (SPECT) images. It is also to identify the conditions to be fulfilled to obtain reliable quantitative measurements from images. Content: 1 - Introduction: Quantification in emission tomography - definition and challenges; quantification biasing phenomena; 2 - quantification in SPECT, problems and correction methods: Attenuation, scattering, un-stationary spatial resolution, partial volume effect, movement, tomographic reconstruction, calibration; 3 - Synthesis: actual quantification accuracy; 4 - Beyond the activity concentration measurement

Occult primary tumors of the head and neck: accuracy of thallium 201 single-photon emission computed tomography and computed tomography and/or magnetic resonance imaging

NARCIS (Netherlands)

van Veen, S. A.; Balm, A. J.; Valdés Olmos, R. A.; Hoefnagel, C. A.; Hilgers, F. J.; Tan, I. B.; Pameijer, F. A.

2001-01-01

To determine the accuracy of thallium 201 single-photon emission computed tomography (thallium SPECT) and computed tomography and/or magnetic resonance imaging (CT/MRI) in the detection of occult primary tumors of the head and neck. Study of diagnostic tests. National Cancer Institute, Amsterdam,

Development of emission computed tomography in Japan

International Nuclear Information System (INIS)

Tanaka, E.

1984-01-01

Two positron emission computed tomography (PCT) devices developed in Japan are described. One is for head and the other for wholebody. The devices show fairly quantitative images with slight modifications of the existing algorithms because they were developed based on filtered back-projection. The PCT device seems to be better than the single photon emission computed tomography (SPECT) since it provides adequade compensation for photon attenuation in patients. (M.A.C.) [pt

Measuring techniques in emission computed tomography

International Nuclear Information System (INIS)

Jordan, K.; Knoop, B.

1988-01-01

The chapter reviews the historical development of the emission computed tomography and its basic principles, proceeds to SPECT and PET, special techniques of emission tomography, and concludes with a comprehensive discussion of the mathematical fundamentals of the reconstruction and the quantitative activity determination in vivo, dealing with radon transformation and the projection slice theorem, methods of image reconstruction such as analytical and algebraic methods, limiting conditions in real systems such as limited number of measured data, noise enhancement, absorption, stray radiation, and random coincidence. (orig./HP) With 111 figs., 6 tabs [de

Computer tomography, magnetic resonance imaging, and positron emission tomography or positron emission tomography/computer tomography for detection of metastatic lymph nodes in patients with ovarian cancer: A meta-analysis

International Nuclear Information System (INIS)

Yuan Ying; Gu Zhaoxiang; Tao Xiaofeng; Liu Shiyuan

2012-01-01

Objectives: To compare the diagnostic performances of computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET or PET/CT) for detection of metastatic lymph nodes in patients with ovarian cancer. Methods: Relevant studies were identified with MEDLINE and EMBASE from January 1990 to July 2010. We estimated the weighted summary sensitivities, specificities, OR (odds ratio), and summary receiver operating characteristic (sROC) curves of each imaging technique and conducted pair-wise comparisons using the two-sample Z-test. Meta-regression, subgroup analysis, and funnel plots were also performed to explain the between-study heterogeneity. Results: Eighteen eligible studies were included, with a total of 882 patients. PET or PET/CT was a more accurate modality (sensitivity, 73.2%; specificity, 96.7%; OR [odds ratio], 90.32). No significant difference was detected between CT (sensitivity, 42.6%; specificity, 95.0%; OR, 19.87) and MR imaging (sensitivity, 54.7%; specificity, 88.3%; OR, 12.38). Meta-regression analyses and subgroup analyses revealed no statistical difference. Funnel plots with marked asymmetry suggested a publication bias. Conclusion: FDG-PET or FDG-PET/CT is more accurate than CT and MR imaging in the detection of lymph node metastasis in patients with ovarian cancer.

High-resolution PET [Positron Emission Tomography] for Medical Science Studies

Science.gov (United States)

Budinger, T. F.; Derenzo, S. E.; Huesman, R. H.; Jagust, W. J.; Valk, P. E.

1989-09-01

One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging.

Clinical value of whole body fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of metastatic bladder cancer.

Science.gov (United States)

Yang, Zhongyi; Pan, Lingling; Cheng, Jingyi; Hu, Silong; Xu, Junyan; Ye, Dingwei; Zhang, Yingjian

2012-07-01

To investigate the value of whole-body fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography for the detection of metastatic bladder cancer. From December 2006 to August 2010, 60 bladder cancer patients (median age 60.5 years old, range 32-96) underwent whole body positron emission tomography/computed tomography positron emission tomography/computed tomography. The diagnostic accuracy was assessed by performing both organ-based and patient-based analyses. Identified lesions were further studied by biopsy or clinically followed for at least 6 months. One hundred and thirty-four suspicious lesions were identified. Among them, 4 primary cancers (2 pancreatic cancers, 1 colonic and 1 nasopharyngeal cancer) were incidentally detected, and the patients could be treated on time. For the remaining 130 lesions, positron emission tomography/computed tomography detected 118 true positive lesions (sensitivity = 95.9%). On the patient-based analysis, the overall sensitivity and specificity resulted to be 87.1% and 89.7%, respectively. There was no difference of sensitivity and specificity in patients with or without adjuvant treatment in terms of detection of metastatic sites by positron emission tomography/computed tomography. Compared with conventional imaging modality, positron emission tomography/computed tomography correctly changed the management in 15 patients (25.0%). Positron emission tomography/computed tomography has excellent sensitivity and specificity in the detection of metastatic bladder cancer and it provides additional diagnostic information compared to standard imaging techniques. © 2012 The Japanese Urological Association.

Clinical value of whole body fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of metastatic bladder cancer

International Nuclear Information System (INIS)

Yang Zhongyi; Pan Lingling; Cheng Jingyi; Hu Silong; Xu Junyan; Zhang Yingjian; Ye Dingwei

2012-01-01

The objective of this study was to investigate the value of whole-body fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography for the detection of metastatic bladder cancer. From December 2006 to August 2010, 60 bladder cancer patients (median age 60.5 years old, range 32-96) underwent whole body positron emission tomography/computed tomography positron emission tomography/computed tomography. The diagnostic accuracy was assessed by performing both organ-based and patient-based analyses. Identified lesions were further studied by biopsy or clinically followed for at least 6 months. One hundred and thirty-four suspicious lesions were identified. Among them, 4 primary cancers (2 pancreatic cancers, 1 colonic and 1 nasopharyngeal cancer) were incidentally detected, and the patients could be treated on time. For the remaining 130 lesions, positron emission tomography/computed tomography detected 118 true positive lesions (sensitivity=95.9%). On the patient-based analysis, the overall sensitivity and specificity resulted to be 87.1% and 89.7%, respectively. There was no difference of sensitivity and specificity in patients with or without adjuvant treatment in terms of detection of metastatic sites by positron emission tomography/computed tomography. Compared with conventional imaging modality, positron emission tomography/computed tomography correctly changed the management in 15 patients (25.0%). Positron emission tomography/computed tomography has excellent sensitivity and specificity in the detection of metastatic bladder cancer and it provides additional diagnostic information compared to standard imaging techniques. (author)

Comparison of positron emission tomography/CT and bremsstrahlung imaging following Y-90 radiation synovectomy

International Nuclear Information System (INIS)

Barber, Thomas W.; Yap, Kenneth S.K.; Cherk, Martin H.; Kalff, Victor; Powell, Anne

2013-01-01

The aim of this study is to compare the results of positron emission tomography (PET)/CT with bremsstrahlung imaging following Y-90 radiation synovectomy. All patients referred to our institution for Y-90 radiation synovectomy between July 2011 and February 2012 underwent both PET/CT and bremsstrahlung planar (±single photon emission computed tomography (SPECT) or SPECT/CT) imaging at 4 or 24 h following administration of Y-90 silicate colloid. PET image acquisition was performed for between 15 and 20min. In patients who underwent SPECT, side-by-side comparison with PET was performed and image quality/resolution scored using a five-point scale. The distribution pattern of Y-90 on PET and bremsstrahlung imaging was compared with the intra- or extra-articular location of Y-90 activity on fused PET/CT. Thirteen joints (11 knees and two ankles) were imaged with both PET/CT and planar bremsstrahlung imaging with 12 joints also imaged with bremsstrahlung SPECT. Of the 12 joints imaged with SPECT, PET image quality/resolution was superior in 11 and inferior in one. PET demonstrated a concordant distribution pattern compared with bremsstrahlung imaging in all scans, with the pattern classified as diffuse in 12 and predominantly focal in one. In all 12 diffuse scans, PET/CT confirmed the Y-90 activity to be located intra-articularly. In the one predominantly focal scan, the fused PET/CT images localised the Y-90 activity to mostly lie in the extra-articular space of the knee. PET/CT can provide superior image quality compared with bremsstrahlung imaging and may enable reliable detection of extra-articular Y-90 activity when there are focal patterns on planar bremsstrahlung imaging.

Comprehensive Oncologic Imaging in Infants and Preschool Children With Substantially Reduced Radiation Exposure Using Combined Simultaneous ¹⁸F-Fluorodeoxyglucose Positron Emission Tomography/Magnetic Resonance Imaging: A Direct Comparison to ¹⁸F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Science.gov (United States)

Gatidis, Sergios; Schmidt, Holger; Gücke, Brigitte; Bezrukov, Ilja; Seitz, Guido; Ebinger, Martin; Reimold, Matthias; Pfannenberg, Christina A; Nikolaou, Konstantin; Schwenzer, Nina F; Schäfer, Jürgen F

2016-01-01

The aim of this study was to evaluate the clinical applicability and technical feasibility of fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) compared with FDG PET/computed tomography (CT) in young children focusing on lesion detection, PET quantification, and potential savings in radiation exposure. Twenty examinations (10 PET/CT and 10 PET/MRI examinations) were performed prospectively in 9 patients with solid tumors (3 female, 6 male; mean age, 4.8 [1-6] years). Fluorodeoxyglucose PET/CT and FDG PET/MRI were performed sequentially after a single tracer injection. Lesion detection and analysis were performed independently in PET/CT and PET/MRI. Potential changes in diagnostic or therapeutic patient management were recorded. Positron emission tomography quantification in PET/MRI was evaluated by comparing standardized uptake values resulting from MRI-based and CT-based attenuation correction. Effective radiation doses of PET and CT were estimated. Twenty-one PET-positive lesions were found congruently in PET/CT and PET/MRI. Magnetic resonance imaging enabled significantly better detection of morphologic PET correlates compared with CT. Eight suspicious PET-negative lesions were identified by MRI, of which one was missed in CT. Sensitivity, specificity, and accuracy for correct lesion classification were not significantly different (90%, 47%, and 62% in PET/CT; 100%, 68%, and 79% in PET/MRI, respectively). In 4 patients, the use of PET/MRI resulted in a potential change in diagnostic management compared with PET/CT, as local and whole-body staging could be performed within 1 single examination. In 1 patient, PET/MRI initiated a change in therapeutic management. Positron emission tomography quantification using MRI-based attenuation correction was accurate compared with CT-based attenuation correction. Higher standardized uptake value deviations of about 18% were observed in the lungs due to misclassification in MRI

Sparse representation and dictionary learning penalized image reconstruction for positron emission tomography

International Nuclear Information System (INIS)

Chen, Shuhang; Liu, Huafeng; Shi, Pengcheng; Chen, Yunmei

2015-01-01

Accurate and robust reconstruction of the radioactivity concentration is of great importance in positron emission tomography (PET) imaging. Given the Poisson nature of photo-counting measurements, we present a reconstruction framework that integrates sparsity penalty on a dictionary into a maximum likelihood estimator. Patch-sparsity on a dictionary provides the regularization for our effort, and iterative procedures are used to solve the maximum likelihood function formulated on Poisson statistics. Specifically, in our formulation, a dictionary could be trained on CT images, to provide intrinsic anatomical structures for the reconstructed images, or adaptively learned from the noisy measurements of PET. Accuracy of the strategy with very promising application results from Monte-Carlo simulations, and real data are demonstrated. (paper)

Positron emission tomography

International Nuclear Information System (INIS)

Reivich, M.; Alavi, A.

1985-01-01

This book contains 24 selections. Some of the titles are: Positron Emission Tomography Instrumentation, Generator Systems for Positron Emitters, Reconstruction Algorithms, Cerebral Glucose Consumption: Methodology and Validation, Cerebral Blood Flow Tomography Using Xenon-133 Inhalation: Methods and Clinical Applications, PET Studies of Stroke, Cardiac Positron Emission Tomography, and Use of PET in Oncology

Model-based respiratory motion compensation for emission tomography image reconstruction

International Nuclear Information System (INIS)

Reyes, M; Malandain, G; Koulibaly, P M; Gonzalez-Ballester, M A; Darcourt, J

2007-01-01

In emission tomography imaging, respiratory motion causes artifacts in lungs and cardiac reconstructed images, which lead to misinterpretations, imprecise diagnosis, impairing of fusion with other modalities, etc. Solutions like respiratory gating, correlated dynamic PET techniques, list-mode data based techniques and others have been tested, which lead to improvements over the spatial activity distribution in lungs lesions, but which have the disadvantages of requiring additional instrumentation or the need of discarding part of the projection data used for reconstruction. The objective of this study is to incorporate respiratory motion compensation directly into the image reconstruction process, without any additional acquisition protocol consideration. To this end, we propose an extension to the maximum likelihood expectation maximization (MLEM) algorithm that includes a respiratory motion model, which takes into account the displacements and volume deformations produced by the respiratory motion during the data acquisition process. We present results from synthetic simulations incorporating real respiratory motion as well as from phantom and patient data

Axial positrons emission tomography: from mouse to human brain imaging

International Nuclear Information System (INIS)

Brard, Emmanuel

2013-01-01

Positrons emission tomography is a nuclear imaging technics using nuclear decays. It is used both in clinical and preclinical studies. The later requires the use of small animals such as the mouse. The objective is to obtain the best signal with the best spatial resolution. Yet, a weight ratio between humans and mice indicates the need of a sub-millimeter resolution. A conventional scanner is based on detection modules surrounding the object to image and arranged perpendicularly. This implies a strong relationship between efficiency and spatial resolution. This work focuses on the axial geometry in which detection modules are arranged parallel to the object. This limits the relationship between the figures of merit, leading to both high spatial resolution and efficiency. The simulations of prototypes showed great perspectives in term of sub-millimeter resolution with efficiencies of 15 or 40% according to the scanner's axial extension. These results indicate great perspectives for both clinical and preclinical imaging. (author)

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

Directory of Open Access Journals (Sweden)

Senait Aknaw Debebe

2016-02-01

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

Photons-based medical imaging - Radiology, X-ray tomography, gamma and positrons tomography, optical imaging; Imagerie medicale a base de photons - Radiologie, tomographie X, tomographie gamma et positons, imagerie optique

Energy Technology Data Exchange (ETDEWEB)

Fanet, H.; Dinten, J.M.; Moy, J.P.; Rinkel, J. [CEA Leti, Grenoble (France); Buvat, I. [IMNC - CNRS, Orsay (France); Da Silva, A. [Institut Fresnel, Marseille (France); Douek, P.; Peyrin, F. [INSA Lyon, Lyon Univ. (France); Frija, G. [Hopital Europeen George Pompidou, Paris (France); Trebossen, R. [CEA-Service hospitalier Frederic Joliot, Orsay (France)

2010-07-01

This book describes the different principles used in medical imaging. The detection aspects, the processing electronics and algorithms are detailed for the different techniques. This first tome analyses the photons-based techniques (X-rays, gamma rays and visible light). Content: 1 - physical background: radiation-matter interaction, consequences on detection and medical imaging; 2 - detectors for medical imaging; 3 - processing of numerical radiography images for quantization; 4 - X-ray tomography; 5 - positrons emission tomography: principles and applications; 6 - mono-photonic imaging; 7 - optical imaging; Index. (J.S.)

Positron emission tomography of malignant tumours at head and neck. Evaluation of the diagnostic value of positron emission tomography by comparison with computed tomography

International Nuclear Information System (INIS)

Kettler, Nele

2011-01-01

Imaging methods for early, accurate diagnosis and aftercare of malignant growths is currently one of the most important research topics. The objective of this thesis is to evaluate the diagnostic value of FDG-positron emission tomography by comparison with computed tomography for patients with squamous cell carcinoma, malignant melanoma or sarcoma at head and neck. Measurement criteria are sensitivity and specificity. A retrospective evaluation of 100 examinations on 85 patients of University clinic Aachen was performed. The examination reports were supported by reports from histology, positron emission tomography and computed tomography. In each case, the histological results were assumed to provide a reliable benchmark. Sensitivity and specificity for the primary tumour site, metastatic lymphatic nodes and defined anatomic structures were compared across all patients. Comparisons were also performed on sub groups separated by gender, cancer type and the time and frequency at which tumours arose. The statistic analysis was done with MedCalc. Results: The results for sensitivity and specificity of the primary tumour site were 86.42% and 42.86%, and 64.71% and 66.07%, for positron emission tomography and computed tomography respectively. The results for the lymphatic nodes were 51.52% and 92.86% and 64.71% and 66.07%. When the constituent anatomic structures were evaluated separately, the specificity was significantly higher. The separation by gender showed no difference. Because the classification by tumor type resulted in samples that were of varying size, a comparison was difficult. For the diagnosis of primary tumours, the examination with positron emission tomography was superior, whereas computed tomography proved more effective for the diagnosis of recurrent tumours. For the diagnosis of the main tumour site, both methods were shown to be equally suitable. For the assessment of lymphatic nodes, positron emission tomography was superior to computed tomography

Comparing staging by positron emission tomography with contrast-enhanced computed tomography and by pathology in head and neck squamous cell carcinoma.

Science.gov (United States)

Qualliotine, J R; Mydlarz, W K; Chan, J Y K; Zhou, X; Wang, H; Agrawal, N

2015-12-01

This study aimed to evaluate the ability of positron emission tomography with contrast-enhanced computed tomography to correctly stage head and neck squamous cell carcinomas, in comparison with pathological staging. Positron emission tomography computed tomography was used to determine the tumour-node-metastasis classification and overall cancer stage in 85 head and neck squamous cell carcinoma patients who underwent pre-operative imaging using this modality and primary surgery between July 2010 and January 2013. Staging by positron emission tomography computed tomography was retrospectively compared with staging using pathological specimens. Agreement between imaging stage and pathological stage was examined by univariate and multivariate analysis both overall and for each primary tumour site. This imaging modality was 87.5 per cent sensitive and 44.8 per cent specific in identifying regional cervical metastases, and had false positive and false negative rates of 18.8 per cent and 8.2 per cent, respectively. The positive predictive and negative predictive values were 75.4 per cent and 65.0 per cent, respectively. Univariate and multivariate analyses revealed a significant agreement between positron emission tomography computed tomography and pathological node classification in older patients and for the oral cavity primary tumour site. There was significant agreement between both methods in the overall classification only for tumours classified as T3 or greater. Positron emission tomography computed tomography should be used with caution for the pre-operative staging of head and neck cancers because of its high false positive and false negative rates.

The role of positron emission tomography/computed tomography imaging with radiolabeled choline analogues in prostate cancer.

Science.gov (United States)

Navarro-Pelayo Láinez, M M; Rodríguez-Fernández, A; Gómez-Río, M; Vázquez-Alonso, F; Cózar-Olmo, J M; Llamas-Elvira, J M

2014-11-01

prostate cancer is the most frequent solid malignant tumor in Western Countries. Positron emission tomography/x-ray computed tomography imaging with radiolabeled choline analogues is a useful tool for restaging prostate cancer in patients with rising prostate-specific antigen after radical treatment (in whom conventional imaging techniques have important limitations) as well as in the initial assessment of a selected group of prostate cancer patients. For this reason a literature review is necessary in order to evaluate the usefulness of this imaging test for the diagnosis and treatment of prostate cancer. a MEDLINE (PubMed way) literature search was performed using the search parameters: «Prostate cancer» and «Choline-PET/CT». Other search terms were «Biochemical failure» and/or «Staging» and/or «PSA kinetics». English and Spanish papers were selected; original articles, reviews, systematic reviews and clinical guidelines were included. according to available data, radiolabeled choline analogues plays an important role in the management of prostate cancer, especially in biochemical relapse because technique accuracy is properly correlated with prostate-specific antigen values and kinetics. Although is an emerging diagnostic technique useful in treatment planning of prostate cancer, final recommendations have not been submitted. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

A tumor-targeted polymer theranostics platform for positron emission tomography and fluorescence imaging

Czech Academy of Sciences Publication Activity Database

Koziolová, Eva; Goel, S.; Chytil, Petr; Janoušková, Olga; Barnhart, T. E.; Cai, W.; Etrych, Tomáš

2017-01-01

Roč. 9, č. 30 (2017), s. 10906-10918 ISSN 2040-3364 R&D Projects: GA ČR(CZ) GA15-02986S; GA MZd(CZ) NV16-28594A; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers * positron emission tomography ( PET ) * fluorescence imaging Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 7.367, year: 2016

Fluorinated tracers for imaging cancer with positron emission tomography

International Nuclear Information System (INIS)

Couturier, Olivier; Chatal, Jean-Francois; Luxen, Andre; Vuillez, Jean-Philippe; Rigo, Pierre; Hustinx, Roland

2004-01-01

2-[ 18 F]fluoro-2-deoxy-d-glucose (FDG) is currently the only fluorinated tracer used in routine clinical positron emission tomography (PET). Fluorine-18 is considered the ideal radioisotope for PET imaging owing to the low positron energy (0.64 MeV), which not only limits the dose rate to the patient but also results in a relatively short range of emission in tissue, thereby providing high-resolution images. Further, the 110-min physical half-life allows for high-yield radiosynthesis, transport from the production site to the imaging site and imaging protocols that may span hours, which permits dynamic studies and assessment of potentially fairly slow metabolic processes. The synthesis of fluorinated tracers as an alternative to FDG was initially tested using nucleophilic fluorination of the molecule, as performed when radiolabelling with iodine-124 or bromide-76. However, in addition to being long, with multiple steps, this procedure is not recommended for bioactive molecules containing reactive groups such as amine or thiol groups. Radiochemical yields are also often low. More recently, radiosynthesis from prosthetic group precursors, which allows easier radiolabelling of biomolecules, has led to the development of numerous fluorinated tracers. Given the wide availability of 18 F, such tracers may well develop into important routine tracers. This article is a review of the literature concerning fluorinated radiotracers recently developed and under investigation for possible PET imaging in cancer patients. Two groups can be distinguished. The first includes ''generalist'' tracers, i.e. tracers amenable to use in a wide variety of tumours and indications, very similar in this respect to FDG. These are tracers for non-specific cell metabolism, such as protein synthesis, amino acid transport, nucleic acid synthesis or membrane component synthesis. The second group consists of ''specific'' tracers for receptor expression (i.e. oestrogens or somatostatin), cell

Imaging atherosclerosis with hybrid [18F]fluorodeoxyglucose positron emission tomography/computed tomography imaging: what Leonardo da Vinci could not see.

Science.gov (United States)

Cocker, Myra S; Mc Ardle, Brian; Spence, J David; Lum, Cheemun; Hammond, Robert R; Ongaro, Deidre C; McDonald, Matthew A; Dekemp, Robert A; Tardif, Jean-Claude; Beanlands, Rob S B

2012-12-01

Prodigious efforts and landmark discoveries have led toward significant advances in our understanding of atherosclerosis. Despite significant efforts, atherosclerosis continues globally to be a leading cause of mortality and reduced quality of life. With surges in the prevalence of obesity and diabetes, atherosclerosis is expected to have an even more pronounced impact upon the global burden of disease. It is imperative to develop strategies for the early detection of disease. Positron emission tomography (PET) imaging utilizing [(18)F]fluorodeoxyglucose (FDG) may provide a non-invasive means of characterizing inflammatory activity within atherosclerotic plaque, thus serving as a surrogate biomarker for detecting vulnerable plaque. The aim of this review is to explore the rationale for performing FDG imaging, provide an overview into the mechanism of action, and summarize findings from the early application of FDG PET imaging in the clinical setting to evaluate vascular disease. Alternative imaging biomarkers and approaches are briefly discussed.

Emission tomography: quantitative aspects in metabolic and physiopathologic studies

International Nuclear Information System (INIS)

Yerouchalmi-Soussaline, F.

1984-11-01

This thesis presents instrumental and data processing studies developped in emission tomography in man, using gamma and positron emitting tracers. High contrast visualisation of volume distribution of tracers in the organs, kinetic studies and measurements of radioactive concentration or of other clinical parameters necessitate a detailed analysis of all physical factors limiting the accuracy of the measure; therefore, development of adapted imaging devices and data processing techniques, together with models describing correctly the phenomena under study are to be carried out. Thus, in single photon (gamma) emission tomography an image reconstruction strategy is elaborated, based on an analytical model for the ill-posed problem including the attenuation effect. In positron emission tomography, the time-of-flight information combined with the reconstruction technique is used in the design of a first prototype imaging device which performance is presented and evaluated in a clinical environment. Moreover, a priori or a posteriori techniques correcting for Compton diffusion events, limited statistics and limited resolutions, are proposed and discussed for the improvement of regional measurement accuracy, in metabolic and physiopathologic studies [fr

Single photon emission computerized tomography (SPECT)

International Nuclear Information System (INIS)

Ganatra, R.D.

1992-01-01

Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as 123 I and 99 Tc m that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

Single photon emission computerized tomography (SPECT)

Energy Technology Data Exchange (ETDEWEB)

Ganatra, R D

1993-12-31

Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as {sup 123}I and {sup 99}Tc{sup m} that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

Hypoxia positron emission tomography imaging: combining information on perfusion and tracer retention to improve hypoxia specificity

DEFF Research Database (Denmark)

Busk, Morten; Munk, Ole L; Jakobsen, Steen S

2017-01-01

BACKGROUND: Static positron emission tomography (PET) allows mapping of tumor hypoxia, but low resolution and slow tracer retention/clearance results in poor image contrast and the risk of missing areas where hypoxic cells and necrosis are intermixed. Fully dynamic PET may improve accuracy but scan...

A wavelet phase filter for emission tomography

International Nuclear Information System (INIS)

Olsen, E.T.; Lin, B.

1995-01-01

The presence of a high level of noise is a characteristic in some tomographic imaging techniques such as positron emission tomography (PET). Wavelet methods can smooth out noise while preserving significant features of images. Mallat et al. proposed a wavelet based denoising scheme exploiting wavelet modulus maxima, but the scheme is sensitive to noise. In this study, the authors explore the properties of wavelet phase, with a focus on reconstruction of emission tomography images. Specifically, they show that the wavelet phase of regular Poisson noise under a Haar-type wavelet transform converges in distribution to a random variable uniformly distributed on [0, 2π). They then propose three wavelet-phase-based denoising schemes which exploit this property: edge tracking, local phase variance thresholding, and scale phase variation thresholding. Some numerical results are also presented. The numerical experiments indicate that wavelet phase techniques show promise for wavelet based denoising methods

Feasibility of Computed Tomography-Guided Methods for Spatial Normalization of Dopamine Transporter Positron Emission Tomography Image.

Science.gov (United States)

Kim, Jin Su; Cho, Hanna; Choi, Jae Yong; Lee, Seung Ha; Ryu, Young Hoon; Lyoo, Chul Hyoung; Lee, Myung Sik

2015-01-01

Spatial normalization is a prerequisite step for analyzing positron emission tomography (PET) images both by using volume-of-interest (VOI) template and voxel-based analysis. Magnetic resonance (MR) or ligand-specific PET templates are currently used for spatial normalization of PET images. We used computed tomography (CT) images acquired with PET/CT scanner for the spatial normalization for [18F]-N-3-fluoropropyl-2-betacarboxymethoxy-3-beta-(4-iodophenyl) nortropane (FP-CIT) PET images and compared target-to-cerebellar standardized uptake value ratio (SUVR) values with those obtained from MR- or PET-guided spatial normalization method in healthy controls and patients with Parkinson's disease (PD). We included 71 healthy controls and 56 patients with PD who underwent [18F]-FP-CIT PET scans with a PET/CT scanner and T1-weighted MR scans. Spatial normalization of MR images was done with a conventional spatial normalization tool (cvMR) and with DARTEL toolbox (dtMR) in statistical parametric mapping software. The CT images were modified in two ways, skull-stripping (ssCT) and intensity transformation (itCT). We normalized PET images with cvMR-, dtMR-, ssCT-, itCT-, and PET-guided methods by using specific templates for each modality and measured striatal SUVR with a VOI template. The SUVR values measured with FreeSurfer-generated VOIs (FSVOI) overlaid on original PET images were also used as a gold standard for comparison. The SUVR values derived from all four structure-guided spatial normalization methods were highly correlated with those measured with FSVOI (P normalization methods provided reliable striatal SUVR values comparable to those obtained with MR-guided methods. CT-guided methods can be useful for analyzing dopamine transporter PET images when MR images are unavailable.

New developments in molecular imaging: positron emission tomography time-of-flight (TOF-PET)

International Nuclear Information System (INIS)

Aguilar, P.; Couce, B.; Iglesias, A.; Lois, C.

2011-01-01

Positron Emission tomography (PET) in increasingly being used in oncology for the diagnosis and staging of disease, as well as in monitoring response to therapy. One of the last advances in PET is the incorporation of Time-of-Flight (TOF) information, which improves the tomographic reconstruction process and subsequently the quality of the final image. In this work, we explain the principles of PET and the fundamentals of TOF-PET. Clinical images are shown in order to illustrate how TOF-PET improves the detectability of small lesions, particularly in patients with high body mass index. (Author) 20 refs

Development of radiotracers for imaging NR2B subtype NMDA receptors with positron emission tomography

International Nuclear Information System (INIS)

Labas, R.

2007-01-01

The aim of this thesis was to develop new radioactive tracers for imaging NR2B subtype NMDA receptors with positron emission tomography. Several compounds including 4-(4-fluoro-benzyl)piperidine and presenting interesting in vivo biological properties were the object of a labelling with a positrons emitter atom ( 11 C or 18 F)

The display of multiple images derived from emission computed assisted tomography (ECAT)

International Nuclear Information System (INIS)

Jackson, P.C.; Davies, E.R.; Goddard, P.R.; Wilde, R.P.H.

1983-01-01

In emission computed assisted tomography, a technique has been developed to display the multiple sections of an organ within a single image, such that three dimensional appreciation of the organ can be obtained, whilst also preserving functional information. The technique when tested on phantoms showed no obvious deterioration in resolution and when used clinically gave satisfactory visual results. Such a method should allow easier appreciation of the extent of a lesion through an organ and thus allow dimensions to be obtained by direct measurement. (U.K.)

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.

Detectors for high resolution dynamic positron emission tomography

International Nuclear Information System (INIS)

Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.

1985-01-01

Tomography is the technique of producing a photographic image of an opaque specimen by transmitting a beam of x-rays or gamma rays through the specimen onto an adjacent photographic film. The image results from variations in thickness, density, and chemical composition, of the specimen. This technique is used to study the metabolism of the human brain. This article examines the design of equipment used for high resolution dynamic positron emission tomography. 27 references, 5 figures, 3 tables

Patterns of brown fat uptake of 18F-fluorodeoxyglucose in positron emission tomography/computed tomography scan

International Nuclear Information System (INIS)

Chakraborty, Dhritiman; Bhattacharya, Anish; Mittal, Bhagwant Rai

2015-01-01

Fluorodeoxyglucose (FDG) positron emission tomography (PET) has become the common imaging modality in oncological practice. FDG uptake is seen in brown adipose tissue in a significant number of patients. Recognizing the uptake patterns is important for optimal FDG PET interpretation. The introduction of PET/computed tomography (PET/CT) revolutionized PET imaging, bringing much-needed anatomical information. Careful review and correlation of FDG PET images with anatomical imaging should be performed to characterize accurately any lesion having high FDG uptake

About some generalization of calculation algorithm of three-dimensional images in the emission tomography

International Nuclear Information System (INIS)

Koblik, Yu.N.; Khugaev, A.V.; Mktchyan, G.A; Yuldashev, B.S.; Iloannou, P.; Dimovasili, E

2002-01-01

The aim of the work is the generalization of algorithm of processing of images of the objects in the emission tomography for case of arbitrarily directed cuts. In this work the problem of description of the mathematical law of lines of the such cuts in idealized event and with taking into account the parameters of cells in the working cavity of tomograph had been solved

Cardiac positron emission tomography

International Nuclear Information System (INIS)

Eftekhari, M.; Ejmalian, G.

2003-01-01

Positron emission tomography is an intrinsically tool that provide a unique and unparalleled approach for clinicians and researchers to interrogate the heart noninvasively. The ability to label substances of physiological interest with positron-emitting radioisotopes has permitted insight into normal blood flow and metabolism and the alterations that occur with disease states. Positron emission tomography of the heart has evolved as a unique, noninvasive approach for the assessment of myocardial perfusion, metabolism, and function. Because of the intrinsic quantitative nature of positron emission tomography measurements as well as the diverse compounds that can be labeled with positron- emitting radioisotopes, studies with positron emission tomography have provided rich insight into the physiology of the heart under diverse conditions

Carbon-11-methionine positron emission tomography imaging of chordoma

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hong [Department of Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Department of Medical Imaging, Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, 263-8555, Chiba (Japan); Yoshikawa, Kyosan; Tamura, Katsumi; Sagou, Kenji; Kandatsu, Susumu [Clinical Diagnosis Section, National Institute of Radiological Sciences, Chiba (Japan); Tian, Mei; Suhara, Tetsuya; Suzuki, Kazutoshi; Tanada, Shuji [Department of Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Tsujii, Hirohiko [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan)

2004-09-01

Chordoma is a rare malignant bone tumor that arises from notochord remnants. This is the first trial to investigate the utility of {sup 11}C-methionine (MET) positron emission tomography (PET) in the imaging of chordoma before and after carbon-ion radiotherapy (CIRT). Fifteen patients with chordoma were investigated with MET-PET before and after CIRT and the findings analyzed visually and quantitatively. Tumor MET uptake was evaluated by tumor-to-nontumor ratio (T/N ratio). In 12 (80%) patients chordoma was clearly visible in the baseline MET-PET study with a mean T/N ratio of 3.3{+-}1.7. The MET uptake decreased significantly to 2.3{+-}1.4 after CIRT (P<0.05). A significant reduction in tumor MET uptake of 24% was observed after CIRT. Fourteen (93%) patients showed no local recurrence after CIRT with a median follow-up time of 20 months. This study has demonstrated that MET-PET is feasible for imaging of chordoma. MET-PET could provide important tumor metabolic information for the therapeutic monitoring of chordoma after CIRT. (orig.)

Carbon-11-methionine positron emission tomography imaging of chordoma

International Nuclear Information System (INIS)

Zhang, Hong; Yoshikawa, Kyosan; Tamura, Katsumi; Sagou, Kenji; Kandatsu, Susumu; Tian, Mei; Suhara, Tetsuya; Suzuki, Kazutoshi; Tanada, Shuji; Tsujii, Hirohiko

2004-01-01

Chordoma is a rare malignant bone tumor that arises from notochord remnants. This is the first trial to investigate the utility of 11 C-methionine (MET) positron emission tomography (PET) in the imaging of chordoma before and after carbon-ion radiotherapy (CIRT). Fifteen patients with chordoma were investigated with MET-PET before and after CIRT and the findings analyzed visually and quantitatively. Tumor MET uptake was evaluated by tumor-to-nontumor ratio (T/N ratio). In 12 (80%) patients chordoma was clearly visible in the baseline MET-PET study with a mean T/N ratio of 3.3±1.7. The MET uptake decreased significantly to 2.3±1.4 after CIRT (P<0.05). A significant reduction in tumor MET uptake of 24% was observed after CIRT. Fourteen (93%) patients showed no local recurrence after CIRT with a median follow-up time of 20 months. This study has demonstrated that MET-PET is feasible for imaging of chordoma. MET-PET could provide important tumor metabolic information for the therapeutic monitoring of chordoma after CIRT. (orig.)

Imaging Cellular Proliferation in Prostate Cancer with Positron Emission Tomography

Directory of Open Access Journals (Sweden)

Hossein Jadvar

2015-07-01

Full Text Available Prostate cancer remains a major public health problem worldwide. Imaging plays an important role in the assessment of disease at all its clinical phases, including staging, restaging after definitive therapy, evaluation of therapy response, and prognostication. Positron emission tomography with a number of biologically targeted radiotracers has been demonstrated to have potential diagnostic and prognostic utility in the various clinical phases of this prevalent disease. Given the remarkable biological heterogeneity of prostate cancer, one major unmet clinical need that remains is the non-invasive imaging-based characterization of prostate tumors. Accurate tumor characterization allows for image-targeted biopsy and focal therapy as well as facilitates objective assessment of therapy effect. PET in conjunction with radiotracers that track the thymidine salvage pathway of DNA synthesis may be helpful to fulfill this necessity. We review briefly the preclinical and pilot clinical experience with the two major cellular proliferation radiotracers, [18F]-3’-deoxy-3’-fluorothymidine and [18F]-2’-fluoro-5-methyl-1-beta-D-arabinofuranosyluracil in prostate cancer.

T cell homing to tumors detected by 3D-coordinated positron emission tomography and magnetic resonance imaging

DEFF Research Database (Denmark)

Agger, Ralf; Petersen, Mikkel; Petersen, Charlotte Christie

2007-01-01

of magnetic resonance imaging with the high sensitivity and spatial accuracy of positron emission tomography. We have used this technique, together with determination of tissue radioactivity, flow cytometry, and microscopy, to characterize and quantitate the specific accumulation of transferred CD8+ T cells...

Positron emission tomography of incidentally detected small pulmonary nodules

DEFF Research Database (Denmark)

Fischer, B M; Mortensen, J; Dirksen, A

2004-01-01

The aim of this study was to assess the value of fluorodeoxyglucose positron emission tomography (FDG PET) imaging of small pulmonary nodules incidentally detected by spiral computed tomography (CT) in a high-risk population. Ten patients (five females, five males, aged 54-72 years) were recruited...

Influence of the Pixel Sizes of Reference Computed Tomography on Single-photon Emission Computed Tomography Image Reconstruction Using Conjugate-gradient Algorithm.

Science.gov (United States)

Okuda, Kyohei; Sakimoto, Shota; Fujii, Susumu; Ida, Tomonobu; Moriyama, Shigeru

The frame-of-reference using computed-tomography (CT) coordinate system on single-photon emission computed tomography (SPECT) reconstruction is one of the advanced characteristics of the xSPECT reconstruction system. The aim of this study was to reveal the influence of the high-resolution frame-of-reference on the xSPECT reconstruction. 99m Tc line-source phantom and National Electrical Manufacturers Association (NEMA) image quality phantom were scanned using the SPECT/CT system. xSPECT reconstructions were performed with the reference CT images in different sizes of the display field-of-view (DFOV) and pixel. The pixel sizes of the reconstructed xSPECT images were close to 2.4 mm, which is acquired as originally projection data, even if the reference CT resolution was varied. The full width at half maximum (FWHM) of the line-source, absolute recovery coefficient, and background variability of image quality phantom were independent on the sizes of DFOV in the reference CT images. The results of this study revealed that the image quality of the reconstructed xSPECT images is not influenced by the resolution of frame-of-reference on SPECT reconstruction.

Positron Emission Tomography: Principles, Technology, and Recent Developments

Science.gov (United States)

Ziegler, Sibylle I.

2005-04-01

Positron emission tomography (PET) is a nuclear medical imaging technique for quantitative measurement of physiologic parameters in vivo (an overview of principles and applications can be found in [P.E. Valk, et al., eds. Positron Emission Tomography. Basic Science and Clinical Practice. 2003, Springer: Heidelberg]), based on the detection of small amounts of posi-tron-emitter-labelled biologic molecules. Various radiotracers are available for neuro-logical, cardiological, and oncological applications in the clinic and in research proto-cols. This overview describes the basic principles, technology, and recent develop-ments in PET, followed by a section on the development of a tomograph with ava-lanche photodiodes dedicated for small animal imaging as an example of efforts in the domain of high resolution tomographs.

Emission tomography: quantitative aspects in metabolic and physio-pathologic studies

International Nuclear Information System (INIS)

Yerouchalmi-Soussaline, F.

1984-01-01

This thesis presents instrumental and data processing studies developed in emission tomography in man, using gamma and positron emitting tracers. High contrast visualisation of volume distribution of tracers in the organs, kinetic studies and measurements of radioactive concentration or of other clinical parameters necessitate a detailed analysis of all physical factors limiting the accuracy of the measure; therefore, development of adapted imaging devices and data processing techniques, together with models describing correctly the phenomena under study are to be carried out. Thus, in single photon (gamma) emission tomography an image reconstruction strategy is elaborated, based on an analytical model for the ill-posed problem including the attenuation effect. In positron emission tomography, the time-of-flight information combined with the reconstruction technique is used in the design of a first prototype imaging device which performance is presented and evaluated in a clinical environment. Moreover, a priori or a posteriori techniques correcting for Compton diffusion events, limited statistics and limited resolution, are proposed and discussed for the improvement of regional measurement accuracy, in metabolic and physio-pathologic studies. (author) [fr

18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Tuberculosis: Spectrum of Manifestations.

Science.gov (United States)

Agarwal, Krishan Kant; Behera, Abhishek; Kumar, Rakesh; Bal, Chandrasekhar

2017-01-01

The objective of this article is to provide an illustrative tutorial highlighting the utility of 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography ( 18 F-FDG-PET/CT) imaging to detect spectrum of manifestations in patients with tuberculosis (TB). FDG-PET/CT is a powerful tool for early diagnosis, measuring the extent of disease (staging), and consequently for evaluation of response to therapy in patients with TB.

Positron emission tomography

International Nuclear Information System (INIS)

Wienhard, K.; Heiss, W.D.

1984-01-01

The principles and selected clinical applications of positron emission tomography are described. In this technique a chemical compound is labeled with a positron emitting isotope and its biochemical pathway is traced by coincidence detection of the two annihilation photons. The application of the techniques of computed tomography allows to reconstruct the spatial distribution of the radioactivity within a subject. The 18 F-deoxyglucose method for quantitative measurement of local glucose metabolism is discussed in order to illustrate the possibilities of positron emission tomography to record physiological processes in vivo. (orig.) [de

Alternative positron emission tomography with non-conventional positron emitters: effects of their physical properties on image quality and potential clinical applications

International Nuclear Information System (INIS)

Pagani, M.; Stone-Elander, S.; Larsson, S.A.

1997-01-01

The increasing amount of clinically relevant information obtained by positron emission tomography (PET), primarily with fluorine-18 labelled 2-deoxy-2-fluoro-d-glucose, has generated a demand for new routes for the widespread and cost-efficient use of positron-emitting radiopharmaceuticals. New dual-head single-photon emission tomography (SPET) cameras are being developed which offer coincidence detection with camera heads lacking a collimator or SPET imaging with specially designed collimators and additional photon shielding. Thus, not only satellite PET imaging units but also nuclear medicine units investing in these new SPET/PET systems need to examine all available alternatives for rational radionuclide supplies from host cyclotrons. This article examines 25 ''alternative'' positron-emitting radionuclides, discusses the impact of their decay properties on image quality and reviews methods for their production as well as for their application in imaging techniques. (orig.)

Simultaneous in vivo positron emission tomography and magnetic resonance imaging.

Science.gov (United States)

Catana, Ciprian; Procissi, Daniel; Wu, Yibao; Judenhofer, Martin S; Qi, Jinyi; Pichler, Bernd J; Jacobs, Russell E; Cherry, Simon R

2008-03-11

Positron emission tomography (PET) and magnetic resonance imaging (MRI) are widely used in vivo imaging technologies with both clinical and biomedical research applications. The strengths of MRI include high-resolution, high-contrast morphologic imaging of soft tissues; the ability to image physiologic parameters such as diffusion and changes in oxygenation level resulting from neuronal stimulation; and the measurement of metabolites using chemical shift imaging. PET images the distribution of biologically targeted radiotracers with high sensitivity, but images generally lack anatomic context and are of lower spatial resolution. Integration of these technologies permits the acquisition of temporally correlated data showing the distribution of PET radiotracers and MRI contrast agents or MR-detectable metabolites, with registration to the underlying anatomy. An MRI-compatible PET scanner has been built for biomedical research applications that allows data from both modalities to be acquired simultaneously. Experiments demonstrate no effect of the MRI system on the spatial resolution of the PET system and <10% reduction in the fraction of radioactive decay events detected by the PET scanner inside the MRI. The signal-to-noise ratio and uniformity of the MR images, with the exception of one particular pulse sequence, were little affected by the presence of the PET scanner. In vivo simultaneous PET and MRI studies were performed in mice. Proof-of-principle in vivo MR spectroscopy and functional MRI experiments were also demonstrated with the combined scanner.

X-ray-based attenuation correction for positron emission tomography/computed tomography scanners.

Science.gov (United States)

Kinahan, Paul E; Hasegawa, Bruce H; Beyer, Thomas

2003-07-01

A synergy of positron emission tomography (PET)/computed tomography (CT) scanners is the use of the CT data for x-ray-based attenuation correction of the PET emission data. Current methods of measuring transmission use positron sources, gamma-ray sources, or x-ray sources. Each of the types of transmission scans involves different trade-offs of noise versus bias, with positron transmission scans having the highest noise but lowest bias, whereas x-ray scans have negligible noise but the potential for increased quantitative errors. The use of x-ray-based attenuation correction, however, has other advantages, including a lack of bias introduced from post-injection transmission scanning, which is an important practical consideration for clinical scanners, as well as reduced scan times. The sensitivity of x-ray-based attenuation correction to artifacts and quantitative errors depends on the method of translating the CT image from the effective x-ray energy of approximately 70 keV to attenuation coefficients at the PET energy of 511 keV. These translation methods are usually based on segmentation and/or scaling techniques. Errors in the PET emission image arise from positional mismatches caused by patient motion or respiration differences between the PET and CT scans; incorrect calculation of attenuation coefficients for CT contrast agents or metallic implants; or keeping the patient's arms in the field of view, which leads to truncation and/or beam-hardening (or x-ray scatter) artifacts. Proper interpretation of PET emission images corrected for attenuation by using the CT image relies on an understanding of the potential artifacts. In cases where an artifact or bias is suspected, careful inspection of all three available images (CT and PET emission with and without attenuation correction) is recommended. Copyright 2003 Elsevier Inc. All rights reserved.

Positron emission tomography. Basic principles

International Nuclear Information System (INIS)

Rodriguez, Jose Luis; Massardo, Teresa; Gonzalez, Patricio

2001-01-01

The basic principles of positron emission tomography (PET) technique are reviewed. lt allows to obtain functional images from gamma rays produced by annihilation of a positron, a positive beta particle. This paper analyzes positron emitters production in a cyclotron, its general mechanisms, and the various detection systems. The most important clinical applications are also mentioned, related to oncological uses of fluor-l8-deoxyglucose

Stimulated Emission Computed Tomography (NSECT) images enhancement using a linear filter in the frequency domain

Energy Technology Data Exchange (ETDEWEB)

Viana, Rodrigo S.S.; Tardelli, Tiago C.; Yoriyaz, Helio, E-mail: hyoriyaz@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Jackowski, Marcel P., E-mail: mjack@ime.usp.b [University of Sao Paulo (USP), SP (Brazil). Dept. of Computer Science

2011-07-01

In recent years, a new technique for in vivo spectrographic imaging of stable isotopes was presented as Neutron Stimulated Emission Computed Tomography (NSECT). In this technique, a fast neutrons beam stimulates stable nuclei in a sample, which emit characteristic gamma radiation. The photon energy is unique and is used to identify the emitting nuclei. The emitted gamma energy spectra can be used for reconstruction of the target tissue image and for determination of the tissue elemental composition. Due to the stochastic nature of photon emission process by irradiated tissue, one of the most suitable algorithms for tomographic reconstruction is the Expectation-Maximization (E-M) algorithm, once on its formulation are considered simultaneously the probabilities of photons emission and detection. However, a disadvantage of this algorithm is the introduction of noise in the reconstructed image as the number of iterations increases. This increase can be caused either by features of the algorithm itself or by the low sampling rate of projections used for tomographic reconstruction. In this work, a linear filter in the frequency domain was used in order to improve the quality of the reconstructed images. (author)

Stimulated Emission Computed Tomography (NSECT) images enhancement using a linear filter in the frequency domain

International Nuclear Information System (INIS)

Viana, Rodrigo S.S.; Tardelli, Tiago C.; Yoriyaz, Helio; Jackowski, Marcel P.

2011-01-01

In recent years, a new technique for in vivo spectrographic imaging of stable isotopes was presented as Neutron Stimulated Emission Computed Tomography (NSECT). In this technique, a fast neutrons beam stimulates stable nuclei in a sample, which emit characteristic gamma radiation. The photon energy is unique and is used to identify the emitting nuclei. The emitted gamma energy spectra can be used for reconstruction of the target tissue image and for determination of the tissue elemental composition. Due to the stochastic nature of photon emission process by irradiated tissue, one of the most suitable algorithms for tomographic reconstruction is the Expectation-Maximization (E-M) algorithm, once on its formulation are considered simultaneously the probabilities of photons emission and detection. However, a disadvantage of this algorithm is the introduction of noise in the reconstructed image as the number of iterations increases. This increase can be caused either by features of the algorithm itself or by the low sampling rate of projections used for tomographic reconstruction. In this work, a linear filter in the frequency domain was used in order to improve the quality of the reconstructed images. (author)

Imaging of the pancreas using positron emission tomography with N-13 ammonia

International Nuclear Information System (INIS)

Hayashi, N.; Tamaki, N.; Yamamoto, K.; Senda, M.; Yonekura, Y.; Saji, H.; Nishizawa, S.; Adachi, H.; Torizuka, K.

1986-01-01

A new technique for imaging the pancreas was developed using positron emission tomography (PET) with N-13 ammonia. Four healthy volunteers and 15 patients with pancreatic diseases were studied. After intravenous injection of 10-20 mCi of N-13 ammonia, serial PET scans were obtained every 150 seconds. In the healthy subjects, the pancreas was clearly visualized from the earliest scan. Scans in all ten patients with pancreatic cancer were abnormal. In five patients tumors were visualized as hot spots. When there was severe associated pancreatitis due to pancreatic duct obstruction by tumor, the radionuclide accumulation in the pancreas was remarkably low

Single-photon emission computed tomography

International Nuclear Information System (INIS)

Budinger, T.F.

1986-01-01

Single photon tomography dates from the early 1960's when the idea of emission transverse section tomography was presented by Kuhl and Edwards. They used a rectilinear scanner and analogue back-projection methods to detect emissions from a series of sequential positions transverse to the cephaldcaudad axis of the body. This chapter presents an explanation of emission tomography by describing longitudinal and transverse section tomography. In principle all modes of tomography can be considered under the general topic of coded apertures wherein the code ranges from translation of a pinhole collimator to rotation of a parallel hole or focused collimator array

Positron emission tomography

International Nuclear Information System (INIS)

Bolwig, T.G.; Haunsoe, S.; Dahlgaard Hove, J.; Hesse, B.; Hoejgard, L.; Jensen, M.; Paulson, O.B.; Hastrup Svendsen, J.; Soelvsten Soerensen, S.

1994-01-01

Positron emission tomography (PET) is a method for quantitative imaging of regional physiological and biochemical parameters. Positron emitting radioactive isotopes can be produced by a cyclotron, eg. the biologically important carbon ( 11 C), oxygen ( 15 O), and nitrogen ( 13 N) elements. With the tomographic principles of the PET scanner the quantitative distribution of the administered isotopes can be determined and images can be provided as well as dynamic information on blood flow, metabolism and receptor function. In neurology PET has been used for investigations on numerous physiological processes in the brain: circulation, metabolism and receptor studies. In Parkinson's disease PET studies have been able to localize the pathology specifically, and in early stroke PET technique can outline focal areas with living but non-functioning cells, and this could make it possible to intervene in this early state. With positron emission tomography a quantitative evaluation of myocardial blood flow, glucose and fatty acid metabolism can be made as well as combined assessments of blood flow and metabolism. Combined studies of blood flow and metabolism can determine whether myocardial segments with abnormal motility consist of necrotic or viable tissue, thereby delineating effects of revascularisation. In the future it will probably be possible to characterize the myocardial receptor status in different cardiac diseases. The PET technique is used in oncology for clinical as well as more basic research on tumor perfusion and metabolism. Further, tumor uptake of positron labelled cytotoxic drugs might predict the clinical benefit of treatment. (au) (19 refs.)

Magnetic resonance imaging-guided attenuation correction of positron emission tomography data in PET/MRI

OpenAIRE

Izquierdo-Garcia, David; Catana, Ciprian

2016-01-01

Attenuation correction (AC) is one of the most important challenges in the recently introduced combined positron emission tomography/magnetic resonance imaging (PET/MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients (LACs) of the tissues and other components located in the PET field of view (FoV). MR-AC methods can be divided into three main categories: segmentation-, atlas- and PET-based. This review aims to...

Clinical application of positron emission tomography imaging in urologic tumors

International Nuclear Information System (INIS)

Tang Ganghua; Wu Guangyuan

2007-01-01

Positron emission tomography (PET) is an advanced noninvasive molecular imaging modality that is being investigated for use in the differentiation, diagnosis, and guiding therapy ora variety of cancer types. FDG PET has the unique clinical value in the differentiation, diagnosis, and monitoring therapy of prostate, such as bladder, renal, and testicle cancer. However, high false-positive and false-negative findings are observed in the detection of these tumors with FDG PET. 11 C-Choline (CH) and 11 C-acetate (AC) can overcome the pitfall of FDG, and appear to be more successful than FGD in imaging prostate cancer and bladder cancer. The short half-life of 11 C prevents the widespread use of CH and AC and 18 F-fluorocholine (FCH) and 18 F-fluoroacetate (FAC) seem to be potential tracers. Potential clinical value of the new PET tracers, such as 3'-deoxy-3'- 18 F-fluorothymidine (FLT), 18 F-fluorodihydrotestosterone (FDHT), and 9-(4- 18 F-3-hydroxymethylbutyl)-guanine( 18 F-FHBG) in the detection of urologic tumors, can deserve further study. (authors)

Positron emission tomography molecular imaging of dopaminergic system in drug addiction.

Science.gov (United States)

Hou, Haifeng; Tian, Mei; Zhang, Hong

2012-05-01

Dopamine (DA) is involved in drug reinforcement, but its role in drug addiction remains unclear. Positron emission tomography (PET) is the first technology used for the direct measurement of components of the dopaminergic system in the living human brain. In this article, we reviewed the major findings of PET imaging studies on the involvement of DA in drug addiction, especially in heroin addiction. Furthermore, we summarized PET radiotracers that have been used to study the role of DA in drug addiction. To investigate presynaptic function in drug addiction, PET tracers have been developed to measure DA synthesis and transport. For the investigation of postsynaptic function, several radioligands targeting dopamine one (D1) receptor and dopamine two (D2) receptor are extensively used in PET imaging studies. Moreover, we also summarized the PET imaging findings of heroin addiction studies, including heroin-induced DA increases and the reinforcement, role of DA in the long-term effects of heroin abuse, DA and vulnerability to heroin abuse and the treatment implications. PET imaging studies have corroborated the role of DA in drug addiction and increase our understanding the mechanism of drug addiction. Copyright © 2012 Wiley Periodicals, Inc.

Positron emission tomography

International Nuclear Information System (INIS)

Dvorak, O.

1989-01-01

The principle is briefly described of positron emission tomography, and its benefits and constraints are listed. It is emphasized that positron emission tomography (PET) provides valuable information on metabolic changes in the organism that are otherwise only very difficult to obtain, such as brain diagnosis including relationships between mental disorders and the physiology and pathophysiology of the brain. A PET machine is to be installed in Czechoslovakia in the near future. (L.O.)

Development of radioiodinated receptor ligands for cerebral single photon emission tomography

International Nuclear Information System (INIS)

Knapp, F.F. Jr.; McPherson, D.W.

1992-01-01

In the last decade the use of radiolabeled ligands for the imaging of cerebral receptors by emission computed tomography (ECT) has seen rapid growth. The opportunity to routinely perform cerebral single photon emission tomography (SPET) with iodine-123-labeled ligands depends on the availability of receptor ligands into which iodine can be introduced without decreasing the required high target receptor specificity. The use of iodine-123-labeled receptor-specific ligands also depends on the availability of high purity iodine-123 at reasonable costs and the necessary imaging instrumentation. In this paper, the development and current stage of evaluation of various iodine-123-labeled ligands for SPET imaging of dopaminergic, serotonergic and muscarinic acetylcholinergic receptor classes are discussed

Positron emission tomography/computed tomography and radioimmunotherapy of prostate cancer

DEFF Research Database (Denmark)

Bouchelouche, Kirsten; Capala, Jacek; Oehr, Peter

2009-01-01

of a number of diagnostic and therapeutic strategies. J591, a monoclonal antibody, which targets the extracellular domain of prostate-specific membrane antigen, shows promising results. HER2 receptors may also have a potential as target for PET/CT imaging and RIT of advanced prostate cancer. SUMMARY: PET......PURPOSE OF REVIEW: Traditional morphologically based imaging modalities are now being complemented by positron emission tomography (PET)/computed tomography (CT) in prostate cancer. Metastatic prostate cancer is an attractive target for radioimmunotherapy (RIT) as no effective therapies...... are available. This review highlights the most important achievements within the last year in PET/CT and RIT of prostate cancer. RECENT FINDINGS: Conflicting results exist on the use of choline for detection of malignant disease in the prostate gland. The role of PET/CT in N-staging remains to be elucidated...

The added value of 18F-fluorodeoxyglucose positron emission tomography computed tomography in patients with neck lymph node metastases from an unknown primary malignancy.

Science.gov (United States)

Prowse, S J B; Shaw, R; Ganeshan, D; Prowse, P M; Hanlon, R; Lewis-Jones, H; Wieshmann, H

2013-08-01

The search for a primary malignancy in patients with a metastatic cervical lymph node is challenging yet ultimately of utmost clinical importance. This study evaluated the efficacy of positron emission tomography computed tomography in detecting the occult primary, within the context of a tertiary referral centre head and neck cancer multidisciplinary team tumour board meeting. Thirty-two patients (23 men and 9 women; mean and median age, 61 years) with a metastatic cervical lymph node of unknown primary origin, after clinical examination and magnetic resonance imaging, underwent positron emission tomography computed tomography. The primary tumour detection rate was 50 per cent (16/32). Positron emission tomography computed tomography had a sensitivity of 94 per cent (16/17) and a specificity of 67 per cent (10/15). Combining these results with those of 10 earlier studies of similar patients gave an overall detection rate of 37 per cent. Positron emission tomography computed tomography has become an important imaging modality. To date, it has the highest primary tumour detection rate, for head and neck cancer patients presenting with cervical lymph node metastases from an unknown primary.

Features and applications of positron emission tomography

International Nuclear Information System (INIS)

Fan Mingwu

1997-01-01

Positron emission tomography, the so-called world's smartest camera, is based on a NaI or BGO detector and imaging of positron-emitting radioisotopes which are introduced as a tracer into the regional tissue or organ of interest. With the aid of a computer visual images of a series of these distributions can be built into a picture of the functional status of the tissue or organ being imaged. This highly accurate imaging technique is already widely used for clinical diagnostics heart disease, brain disorder, tumors and so on

Digital contrast enhancement of 18Fluorine-fluorodeoxyglucose positron emission tomography images in hepatocellular carcinoma

International Nuclear Information System (INIS)

Pandey, Anil Kumar; Sharma, Sanjay Kumar; Agarwal, Krishan Kant; Sharma, Punit; Bal, Chandrasekhar; Kumar, Rakesh

2016-01-01

The role of 18 fluorodeoxyglucose positron emission tomography (PET) is limited for detection of primary hepatocellular carcinoma (HCC) due to low contrast to the tumor, and normal hepatocytes (background). The aim of the present study was to improve the contrast between the tumor and background by standardizing the input parameters of a digital contrast enhancement technique. A transverse slice of PET image was adjusted for the best possible contrast, and saved in JPEG 2000 format. We processed this image with a contrast enhancement technique using 847 possible combinations of input parameters (threshold “m” and slope “e”). The input parameters which resulted in an image having a high value of 2 nd order entropy, and edge content, and low value of absolute mean brightness error, and saturation evaluation metrics, were considered as standardized input parameters. The same process was repeated for total nine PET-computed tomography studies, thus analyzing 7623 images. The selected digital contrast enhancement technique increased the contrast between the HCC tumor and background. In seven out of nine images, the standardized input parameters “m” had values between 150 and 160, and for other two images values were 138 and 175, respectively. The value of slope “e” was 4 in 4 images, 3 in 3 images and 1 in 2 images. It was found that it is important to optimize the input parameters for the best possible contrast for each image; a particular value was not sufficient for all the HCC images. The use of above digital contrast enhancement technique improves the tumor to background ratio in PET images of HCC and appears to be useful. Further clinical validation of this finding is warranted

Serotonin synthesis studied with positron emission tomography, (PET)

DEFF Research Database (Denmark)

Honoré, Per Gustaf Hartvig; Lundquist, Pinelopi

Positron emission tomography (PET) has the potential to study the biosynthesis and release of serotonin (5HT) at brain serotonergic neurons. PET requires probe compounds with specific attributes to enable imaging and quantification of biological processes. This section focuses on probes to measure...

Imaging of dopamine transporters in rats using high-resolution pinhole single-photon emission tomography

Energy Technology Data Exchange (ETDEWEB)

Booij, Jan; Bruin, Kora de; Habraken, Jan B.A. [Department of Nuclear Medicine, F2N, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Voorn, Pieter [Department of Anatomy, Vrije Universiteit Medical Center, Amsterdam (Netherlands)

2002-09-01

To date, the vast majority of investigations on the dopaminergic system in small animals have been in vitro studies. In comparison with in vitro studies, single-photon emission tomography (SPET) or positron emission tomography (PET) imaging of the dopaminergic system in small animals has the advantage of permitting repeated studies within the same group of animals. Dopamine transporter imaging is a valuable non-invasive tool with which to investigate the integrity of dopaminergic neurons. The purpose of this study was to investigate the feasibility of assessing dopamine transporter density semi-quantitatively in rats using a recently developed high-resolution pinhole SPET system. This system was built exclusively for imaging of small animals. In this unique single-pinhole system, the animal rotates instead of the collimated detector. The system has proven to have a high spatial resolution. We performed SPET imaging with [{sup 123}I]FP-CIT to quantify striatal dopamine transporters in rat brain. In all seven studied control rats, symmetrical striatal binding to dopamine transporters was seen 2 h after injection of the radiotracer, with striatal-to-cerebellar binding ratios of approximately 3.5. In addition, test/retest variability of the striatal-to-cerebellar binding ratios was studied and found to be 14.5%. Finally, in unilaterally 6-hydroxydopamine-lesioned rats, striatal binding was only visible on the non-lesioned side. Quantitative analysis revealed that striatal-to-cerebellar SPET ratios were significantly lower on the lesioned (mean binding ratio 2.2{+-}0.2) than on the non-lesioned (mean ratio 3.1{+-}0.4) side. The preliminary results of this study indicate that semi-quantitative assessment of striatal dopamine transporter density using our recently developed high-resolution single-pinhole SPET system is feasible in living rat brain. (orig.)

Report of two cases of fluorodeoxyglucose positron emission tomography/computed tomography appearance of hibernoma: A rare benign tumor

International Nuclear Information System (INIS)

Agrawal, Archi; Kembhavi, Seema; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

2014-01-01

False-positive findings are commonly seen in positron emission tomography computed tomography imaging. One of the most common false positive finding is uptake of fluorodeoxyglucose in brown adipose tissue. Herein, we report two cases with incidentally detected hibernomas-a brown fat containing tumor with metabolic activity

Single photon emission computed tomography and albumin colloid imaging of the liver

International Nuclear Information System (INIS)

Croft, B.Y.; Teates, C.D.; Honeyman, J.C.

1984-01-01

A single photon emission computed tomography (ECT) system using the GE 400T Anger camera with 37 PM tubes and the SPETS software has been installed in our clinical laboratory. It has been used in the study of liver imaging with Tc-99m albumin colloid and other agents. The object of the study is to define what improvement in liver diagnosis might be made using ECT. Patients were injected with 3-4 mCi (ca 120 MBq) of colloid; five standard liver-spleen views and a 64-image ECT study were acquired. The ECT images were acquired either in a circle of the radius of the longer transverse axis of the patient or in an ellipse to match the patient contour. Studies were corrected for the attenuation of the Tc-99m gamma rays by tissue. A series of normal and abnormal patients have been studied and the data analyzed. The significant change in the technique of ECT imaging is the elliptical motion of the camera head which allows a better approximation of the patient contour and improves the spatial resolution of the images. (orig.)

Partial Volume Effects correction in emission tomography

International Nuclear Information System (INIS)

Le Pogam, Adrien

2010-01-01

Partial Volume Effects (PVE) designates the blur commonly found in nuclear medicine images and this PhD work is dedicated to their correction with the objectives of qualitative and quantitative improvement of such images. PVE arise from the limited spatial resolution of functional imaging with either Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT). They can be defined as a signal loss in tissues of size similar to the Full Width at Half Maximum (FWHM) of the PSF of the imaging device. In addition, PVE induce activity cross contamination between adjacent structures with different tracer uptakes. This can lead to under or over estimation of the real activity of such analyzed regions. Various methodologies currently exist to compensate or even correct for PVE and they may be classified depending on their place in the processing chain: either before, during or after the image reconstruction process, as well as their dependency on co-registered anatomical images with higher spatial resolution, for instance Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). The voxel-based and post-reconstruction approach was chosen for this work to avoid regions of interest definition and dependency on proprietary reconstruction developed by each manufacturer, in order to improve the PVE correction. Two different contributions were carried out in this work: the first one is based on a multi-resolution methodology in the wavelet domain using the higher resolution details of a co-registered anatomical image associated to the functional dataset to correct. The second one is the improvement of iterative deconvolution based methodologies by using tools such as directional wavelets and curvelets extensions. These various developed approaches were applied and validated using synthetic, simulated and clinical images, for instance with neurology and oncology applications in mind. Finally, as currently available PET/CT scanners incorporate more

Representation of photon limited data in emission tomography using origin ensembles

Energy Technology Data Exchange (ETDEWEB)

Sitek, A [Radiology Department, Brigham and Women' s Hospital and Harvard Medical School, 75 Francis Street, Boston, MA 02115 (United States)], E-mail: asitek@bwh.harvard.edu

2008-06-21

Representation and reconstruction of data obtained by emission tomography scanners are challenging due to high noise levels in the data. Typically, images obtained using tomographic measurements are represented using grids. In this work, we define images as sets of origins of events detected during tomographic measurements; we call these origin ensembles (OEs). A state in the ensemble is characterized by a vector of 3N parameters Y, where the parameters are the coordinates of origins of detected events in a three-dimensional space and N is the number of detected events. The 3N-dimensional probability density function (PDF) for that ensemble is derived, and we present an algorithm for OE image estimation from tomographic measurements. A displayable image (e.g. grid based image) is derived from the OE formulation by calculating ensemble expectations based on the PDF using the Markov chain Monte Carlo method. The approach was applied to computer-simulated 3D list-mode positron emission tomography data. The reconstruction errors for a 10 000 000 event acquisition for simulated ranged from 0.1 to 34.8%, depending on object size and sampling density. The method was also applied to experimental data and the results of the OE method were consistent with those obtained by a standard maximum-likelihood approach. The method is a new approach to representation and reconstruction of data obtained by photon-limited emission tomography measurements.

Representation of photon limited data in emission tomography using origin ensembles

Science.gov (United States)

Sitek, A.

2008-06-01

Representation and reconstruction of data obtained by emission tomography scanners are challenging due to high noise levels in the data. Typically, images obtained using tomographic measurements are represented using grids. In this work, we define images as sets of origins of events detected during tomographic measurements; we call these origin ensembles (OEs). A state in the ensemble is characterized by a vector of 3N parameters Y, where the parameters are the coordinates of origins of detected events in a three-dimensional space and N is the number of detected events. The 3N-dimensional probability density function (PDF) for that ensemble is derived, and we present an algorithm for OE image estimation from tomographic measurements. A displayable image (e.g. grid based image) is derived from the OE formulation by calculating ensemble expectations based on the PDF using the Markov chain Monte Carlo method. The approach was applied to computer-simulated 3D list-mode positron emission tomography data. The reconstruction errors for a 10 000 000 event acquisition for simulated ranged from 0.1 to 34.8%, depending on object size and sampling density. The method was also applied to experimental data and the results of the OE method were consistent with those obtained by a standard maximum-likelihood approach. The method is a new approach to representation and reconstruction of data obtained by photon-limited emission tomography measurements.

Representation of photon limited data in emission tomography using origin ensembles

International Nuclear Information System (INIS)

Sitek, A

2008-01-01

Representation and reconstruction of data obtained by emission tomography scanners are challenging due to high noise levels in the data. Typically, images obtained using tomographic measurements are represented using grids. In this work, we define images as sets of origins of events detected during tomographic measurements; we call these origin ensembles (OEs). A state in the ensemble is characterized by a vector of 3N parameters Y, where the parameters are the coordinates of origins of detected events in a three-dimensional space and N is the number of detected events. The 3N-dimensional probability density function (PDF) for that ensemble is derived, and we present an algorithm for OE image estimation from tomographic measurements. A displayable image (e.g. grid based image) is derived from the OE formulation by calculating ensemble expectations based on the PDF using the Markov chain Monte Carlo method. The approach was applied to computer-simulated 3D list-mode positron emission tomography data. The reconstruction errors for a 10 000 000 event acquisition for simulated ranged from 0.1 to 34.8%, depending on object size and sampling density. The method was also applied to experimental data and the results of the OE method were consistent with those obtained by a standard maximum-likelihood approach. The method is a new approach to representation and reconstruction of data obtained by photon-limited emission tomography measurements

Combined computed tomography and fluorodeoxyglucose positron emission tomography in the diagnosis of prosthetic valve endocarditis: a case series.

Science.gov (United States)

Bartoletti, Michele; Tumietto, Fabio; Fasulo, Giovanni; Giannella, Maddalena; Cristini, Francesco; Bonfiglioli, Rachele; Raumer, Luigi; Nanni, Cristina; Sanfilippo, Silvia; Di Eusanio, Marco; Scotton, Pier Giorgio; Graziosi, Maddalena; Rapezzi, Claudio; Fanti, Stefano; Viale, Pierluigi

2014-01-13

The diagnosis of prosthetic valve endocarditis is challenging. The gold standard for prosthetic valve endocarditis diagnosis is trans-esophageal echocardiography. However, trans-esophageal echocardiography may result in negative findings or yield images difficult to differentiate from thrombus in patients with prosthetic valve endocarditis. Combined computed tomography and fluorodeoxyglucose positron emission tomography is a potentially promising diagnostic tool for several infectious conditions and it has also been employed in patients with prosthetic valve endocarditis but data are still scant. We reviewed the charts of 6 patients with prosthetic aortic valves evaluated for suspicion of prosthetic valve endocarditis, at two different hospital, over a 3-year period. We found 3 patients with early-onset PVE cases and blood cultures yielding Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus lugdunensis, respectively; and 3 late-onset cases in the remaining 3 patients with isolation in the blood of Streptococcus bovis, Candida albicans and P. aeruginosa, respectively. Initial trans-esophageal echocardiography was negative in all the patients, while fluorodeoxyglucose positron emission tomography showed images suspicious for prosthetic valve endocarditis. In 4 out of 6 patients valve replacement was done with histology confirming the prosthetic valve endocarditis diagnosis. After an adequate course of antibiotic therapy fluorodeoxyglucose positron emission tomography showed resolution of prosthetic valve endocarditis in all the patients. Our experience confirms the potential role of fluoroseoxyglucose positron emission tomography in the diagnosis and follow-up of prosthetic valve endocarditis.

Attenuation correction in emission tomography using the emission data—A review

Energy Technology Data Exchange (ETDEWEB)

Berker, Yannick, E-mail: berker@mail.med.upenn.edu; Li, Yusheng [Department of Radiology, University of Pennsylvania, 3620 Hamilton Walk, Philadelphia, Pennsylvania 19104 (United States)

2016-02-15

The problem of attenuation correction (AC) for quantitative positron emission tomography (PET) had been considered solved to a large extent after the commercial availability of devices combining PET with computed tomography (CT) in 2001; single photon emission computed tomography (SPECT) has seen a similar development. However, stimulated in particular by technical advances toward clinical systems combining PET and magnetic resonance imaging (MRI), research interest in alternative approaches for PET AC has grown substantially in the last years. In this comprehensive literature review, the authors first present theoretical results with relevance to simultaneous reconstruction of attenuation and activity. The authors then look back at the early history of this research area especially in PET; since this history is closely interwoven with that of similar approaches in SPECT, these will also be covered. We then review algorithmic advances in PET, including analytic and iterative algorithms. The analytic approaches are either based on the Helgason–Ludwig data consistency conditions of the Radon transform, or generalizations of John’s partial differential equation; with respect to iterative methods, we discuss maximum likelihood reconstruction of attenuation and activity (MLAA), the maximum likelihood attenuation correction factors (MLACF) algorithm, and their offspring. The description of methods is followed by a structured account of applications for simultaneous reconstruction techniques: this discussion covers organ-specific applications, applications specific to PET/MRI, applications using supplemental transmission information, and motion-aware applications. After briefly summarizing SPECT applications, we consider recent developments using emission data other than unscattered photons. In summary, developments using time-of-flight (TOF) PET emission data for AC have shown promising advances and open a wide range of applications. These techniques may both remedy

Reproducibility of serial peri-ictal single-photon emission tomography difference images in epilepsy patients undergoing surgical resection

International Nuclear Information System (INIS)

Avery, R.A.; Studholme, C.; Stokking, R.; Morano, G.; Corsi, M.; Seibyl, J.P.; Zubal, I.G.; Spencer, S.S.; Spencer, D.D.

2000-01-01

Peri-ictal single-photon emission tomography (SPET) difference images co-registered to magnetic resonance imaging (MRI) visualize regional cerebral blood flow (rCBF) changes and help localize the epileptogenic area in medically refractory epilepsy. Few reports have examined the reproducibility of SPET difference image results. Epilepsy patients having two peri-ictal and at least one interictal SPET scan who later underwent surgical resection were studied. Localization accuracy of peri-ictal SPET difference images results, interictal electroencephalography (EEG), and ictal EEG from the first (seizure 1) and second (seizure 2) seizure, as well as MRI and positron emission tomography (PET) findings, were compared using surgical resection site as the standard. Thirteen patients underwent surgical resection (11 temporal lobe and 2 extratemporal). SPET results from seizure 1 were localized to the surgical site in 12/13 (92%) patients, while SPET results from seizure 2 were localized in 13/13 (100%) patients. All other modalities were less accurate than the SPET results [interictal EEG - seizure 1 6/13 (46%); ictal EEG - seizure 1 5/13 (38%); interictal intracranial EEG - seizure 2 4/9 (44%); ictal intracranial EEG - seizure 2 results 8/9 (89%); MRI 6/13 (46%); PET 9/13 (69%)]. SPET results were reproducible in 12/13 (92%) patients. SPET difference images calculated from two independent peri-ictal scans appear to be reproducible and accurately localize the epileptogenic area. While SPET difference images visualize many areas of rCBF change, the quantification of these results along with consideration of injection time improves the diagnostic interpretation of the results. (orig.)

Influence of 18F-fluorodeoxyglucose-positron emission tomography on computed tomography-based radiation treatment planning for oesophageal cancer

International Nuclear Information System (INIS)

Everitt, C.; Leong, T.

2006-01-01

The addition of positron emission tomography (PET) information to CT-based radiotherapy treatment planning has the potential to improve target volume definition through more accurate localization of the primary tumour and involved regional lymph nodes. This case report describes the first patient enrolled to a prospective study evaluating the effects of coregistered positron emission tomography/CT images on radiotherapy treatment planning for oesophageal cancer. The results show that if combined positron emission tomography/CT is used for radiotherapy treatment planning, there may be alterations to the delineation of tumour volumes when compared to CT alone. For this patient, a geographic miss of tumour would have occurred if CT data alone were used for radiotherapy planning Copyright (2006) Blackwell Publishing Asia Pty Ltd

Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

Directory of Open Access Journals (Sweden)

Erdem Sürücü

2016-10-01

Full Text Available A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT.

Fasciola Hepatica Mimicking Malignancy on 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

Science.gov (United States)

Sürücü, Erdem; Demir, Yusuf; Dülger, Ahmet C.; Batur, Abdüssamed; Ölmez, Şehmus; Kitapçı, Mehmet T.

2016-01-01

A 48-year-old female with complaints of gastrointestinal symptoms such as abdominal pain, fatigue, vomiting, nausea, and weight loss was diagnosed with neuroendocrine tumor after removal of a 2 mm lesion from the stomach with endoscopic biopsy. Her magnetic resonance imaging that was performed due to on-going symptoms showed multiple linear hypointense lesions in the liver. Positron emission tomography/computed tomography (PET/CT) scan was performed for differential diagnosis, which showed high fluorodeoxyglucose (FDG) uptake in these lesions. Clinical and laboratory findings revealed the final diagnosis as Fasciola hepatica. The imaging features of this case is presented to aid in differentiating this infectious disease from malignancy and avoid misdiagnosis on FDG-PET/CT. PMID:27751978

Non-oncological positron emission tomography (PET): brain imaging; La tomographie par emission de positons (TEP) hors oncologie: l'exploration du cerveau

Energy Technology Data Exchange (ETDEWEB)

Lomena, F. [Centro de Diagnostico por la imagen (CDIC), Hospital Clinic, Servicio de medicina nuclear, Barcelona (Spain)

2008-10-15

Positron emission tomography (PET) allows evaluation of the central nervous system function. Imaging of regional cerebral blood flow and metabolism, and of several neurotransmission systems may be obtained using PET. PET quantification is accurate and has good test-retest reliability. For research purposes, PET has been used to study brain physiology, to explore neurological and psychiatric diseases pathophysiology and for the new drugs research and development. F.D.G. is the only PET radioligand with clinical application. Following criteria of evidence-based medicine, the clinical indications of F.D.G.-PET are: evaluation of treated gliomas, pre surgical study of partial refractory epilepsy and diagnosis of Alzheimer's disease when it is impossible to differentiate clinically from fronto-temporal dementia.

Single-Photon Emission Computerized Tomography (SPECT in Neuropsychiatry: A Review

Directory of Open Access Journals (Sweden)

B. K. Puri

1992-01-01

Full Text Available Cranial single-photon emission computerized tomography (SPECT or SPET can now give regional cerebral blood flow images with a resolution approaching that of positron emission tomography (PET. In this paper, the use of high resolution SPECT neuroimaging in neuropsychiatric disorders, including Alzheimer's disease, multi-infarct dementia, Pick's disease, progressive supranuclear palsy, Korsakoff's psychosis, Creutzfeld-Jakob disease, Parkinson's disease, Huntington's disease, schizophrenia, mood disorders, obsessive–compulsive disorder, HIV infection and AIDS is reviewed. Finally, further potential research and clinical uses, based on ligand studies, are outlined.

Improved diagnostic performance of exercise thallium-201 single photon emission computed tomography over planar imaging in the diagnosis of coronary artery disease: a receiver operating characteristic analysis

International Nuclear Information System (INIS)

Fintel, D.J.; Links, J.M.; Brinker, J.A.; Frank, T.L.; Parker, M.; Becker, L.C.

1989-01-01

Qualitative interpretation of tomographic and planar scintigrams, a five point rating scale and receiver operating characteristic analysis were utilized to compare single photon emission computed tomography and conventional planar imaging of myocardial thallium-201 uptake in the accuracy of the diagnosis of coronary artery disease and individual vessel involvement. One hundred twelve patients undergoing cardiac catheterization and 23 normal volunteers performed symptom-limited treadmill exercise, followed by stress and redistribution imaging by both tomographic and planar techniques, with the order determined randomly. Paired receiver operating characteristic curves revealed that single photon emission computed tomography was more accurate than planar imaging over the entire range of decision thresholds for the overall detection and exclusion of coronary artery disease and involvement of the left anterior descending and left circumflex coronary arteries. Tomography offered relatively greater advantages in male patients and in patients with milder forms of coronary artery disease, who had no prior myocardial infarction, only single vessel involvement or no lesion greater than or equal to 50 to 69%. Tomography did not appear to provide improved diagnosis in women or in detection of disease in the right coronary artery. Although overall detection of coronary artery disease was not improved in patients with prior myocardial infarction, tomography provided improved identification of normal and abnormal vascular regions. These results indicate that single photon emission computed tomography provides improved diagnostic performance compared with planar imaging in many clinical subgroups

Hybrid Gama Emission Tomography (HGET): FY16 Annual Report

Energy Technology Data Exchange (ETDEWEB)

Miller, Erin A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Smith, Leon E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wittman, Richard S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Campbell, Luke W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Deshmukh, Nikhil S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zalavadia, Mital A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Batie, Margo A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mozin, Vladimir V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-02-01

Current International Atomic Energy Agency (IAEA) methodologies for the verification of fresh low-enriched uranium (LEU) and mixed oxide (MOX) fuel assemblies are volume-averaging methods that lack sensitivity to individual pins. Further, as fresh fuel assemblies become more and more complex (e.g., heavy gadolinium loading, high degrees of axial and radial variation in fissile concentration), the accuracy of current IAEA instruments degrades and measurement time increases. Particularly in light of the fact that no special tooling is required to remove individual pins from modern fuel assemblies, the IAEA needs new capabilities for the verification of unirradiated (i.e., fresh LEU and MOX) assemblies to ensure that fissile material has not been diverted. Passive gamma emission tomography has demonstrated potential to provide pin-level verification of spent fuel, but gamma-ray emission rates from unirradiated fuel emissions are significantly lower, precluding purely passive tomography methods. The work presented here introduces the concept of Hybrid Gamma Emission Tomography (HGET) for verification of unirradiated fuels, in which a neutron source is used to actively interrogate the fuel assembly and the resulting gamma-ray emissions are imaged using tomographic methods to provide pin-level verification of fissile material concentration.

Towards factor analysis exploration applied to positron emission tomography functional imaging for breast cancer characterization

International Nuclear Information System (INIS)

Rekik, W.; Ketata, I.; Sellami, L.; Ben slima, M.; Ben Hamida, A.; Chtourou, K.; Ruan, S.

2011-01-01

This paper aims to explore the factor analysis when applied to a dynamic sequence of medical images obtained using nuclear imaging modality, Positron Emission Tomography (PET). This latter modality allows obtaining information on physiological phenomena, through the examination of radiotracer evolution during time. Factor analysis of dynamic medical images sequence (FADMIS) estimates the underlying fundamental spatial distributions by factor images and the associated so-called fundamental functions (describing the signal variations) by factors. This method is based on an orthogonal analysis followed by an oblique analysis. The results of the FADMIS are physiological curves showing the evolution during time of radiotracer within homogeneous tissues distributions. This functional analysis of dynamic nuclear medical images is considered to be very efficient for cancer diagnostics. In fact, it could be applied for cancer characterization, vascularization as well as possible evaluation of response to therapy.

Retroperitoneal Endometriosis: A Possible Cause of False Positive Finding at 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

International Nuclear Information System (INIS)

Maffione, Anna Margherita; Panzavolta, Riccardo; Lisato, Laura Camilla; Ballotta, Maria; D'Isanto, Mariangela Zanforlini; Rubello, Domenico

2015-01-01

Endometriosis is a frequent and clinically relevant problem in young women. Laparoscopy is still the gold standard for the diagnosis of endometriosis, but frequently both morphologic and functional imaging techniques are involved in the diagnostic course before achieving a conclusive diagnosis. We present a case of a patient affected by infiltrating retroperitoneal endometriosis falsely interpreted as a malignant mass by contrast-enhanced magnetic resonance imaging and 18 F-fluorodeoxyglucose positron emission tomography/computed tomography

Positron emission tomography in brain function study

International Nuclear Information System (INIS)

Wu Hua

2006-01-01

Little has been recognized about the advanced brain function. Recent years several new techniques such as event-related potentials, megnetoencephalography, functional magnetic resonance imaging and positron emission tomography (PET) have been used in the study of brain function. The methodology, application study in normal people and clinical patients of PET in brain function are reviewed. (authors)

The impact of optimal respiratory gating and image noise on evaluation of intra-tumor heterogeneity in 18F-FDG positron emission tomography imaging of lung cancer

NARCIS (Netherlands)

Grootjans, W.; Tixier, F.; Vos, C.S. van der; Vriens, D.; Rest, C.C. Le; Bussink, J.; Oyen, W.J.G.; Geus-Oei, L.F. de; Visvikis, D.; Visser, E.P.

2016-01-01

Assessment of measurement accuracy of intra-tumor heterogeneity using texture features in positron emission tomography (PET) images is essential to characterize cancer lesions with high precision. In this study, we investigated the influence of respiratory motion and varying noise levels on

Positron emission tomography. Positronemisionstomografi

Energy Technology Data Exchange (ETDEWEB)

Bolwig, T G; Haunsoe, S; Dahlgaard Hove, J; Hesse, B; Hoejgard, L; Jensen, M; Paulson, O B; Hastrup Svendsen, J; Soelvsten Soerensen, S

1994-10-01

Positron emission tomography (PET) is a method for quantitative imaging of regional physiological and biochemical parameters. Positron emitting radioactive isotopes can be produced by a cyclotron, eg. the biologically important carbon ([sup 11]C), oxygen ([sup 15]O), and nitrogen ([sup 13]N) elements. With the tomographic principles of the PET scanner the quantitative distribution of the administered isotopes can be determined and images can be provided as well as dynamic information on blood flow, metabolism and receptor function. In neurology PET has been used for investigations on numerous physiological processes in the brain: circulation, metabolism and receptor studies. In Parkinson's disease PET studies have been able to localize the pathology specifically, and in early stroke PET technique can outline focal areas with living but non-functioning cells, and this could make it possible to intervene in this early state. With positron emission tomography a quantitative evaluation of myocardial blood flow, glucose and fatty acid metabolism can be made as well as combined assessments of blood flow and metabolism. Combined studies of blood flow and metabolism can determine whether myocardial segments with abnormal motility consist of necrotic or viable tissue, thereby delineating effects of revascularisation. In the future it will probably be possible to characterize the myocardial receptor status in different cardiac diseases. The PET technique is used in oncology for clinical as well as more basic research on tumor perfusion and metabolism. Further, tumor uptake of positron labelled cytotoxic drugs might predict the clinical benefit of treatment. (au) (19 refs.).

Role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in diagnosis and management of pancreatic cancer; comparison with multidetector row computed tomography, magnetic resonance imaging and endoscopic ultrasonography.

Science.gov (United States)

Ergul, N; Gundogan, C; Tozlu, M; Toprak, H; Kadıoglu, H; Aydin, M; Cermik, T F

2014-01-01

We aimed to analyze the contribution of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging to the diagnosis and management of pancreatic cancer compared with multidetector row computed tomography (MDCT), magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS). We retrospectively scanned the data of 52 patients who were referred for FDG PET/CT imaging for evaluation of pancreatic lesions greater than 10mm. The diagnostic performances of 4 imaging methods and the impact of PET/CT on the management of pancreatic cancer were defined. Pancreatic adenocarcinoma was diagnosed in 33 of 52 patients (63%), 15 patients had benign diseases of pancreas (29%), and 4 patients were normal (8%). Sensitivity and NPV of EUS and PET/CT were equal (100%) and higher than MDCT and MRI. Specificity, PPV and NPV of PET/CT were significantly higher than MDCT. However, sensitivities of two imaging methods were not significantly different. There was no significant difference between PET/CT and MRI and EUS for these values. When the cut-off value of SUVmax was 3.2, the most effective sensitivity and specificity values were obtained. PET/CT contributed to the management of pancreatic cancer in 30% of patients. FDG PET/CT is a valuable imaging method for the diagnosis and management of pancreatic cancer, especially when applied along with EUS as first line diagnostic tools. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

Gallium tomoscintigraphic imaging of esophageal cancer using emission computed tomography

International Nuclear Information System (INIS)

Hattori, Takao; Nakagawa, Tsuyoshi; Takeda, Kan; Maeda, Hisato; Taguchi, Mitsuo

1983-01-01

Emission computed tomography (ECT) was clinically evaluated in 67 Ga imaging of esophageal cancer. ECT system used in this study is equipped with opposed dual large-field-of-view cameras (GCA 70A-S, Toshiba Co.). Data were acquired by rotating the two cameras 180 0 about the longitudinal axis of the patient. Total acquisition time was about 12 minutes. Multiple slices of transaxial, sagittal and coronal sections were reconstructed in a 64 x 64 matrix form using convolution algorithms. In three out of six cases studied the tumor uptake was not detected on conventional images, because the lesion was small, concentration of activity was poor or the lesion activity was overlapped with the neighbouring activities distributed to normal organs such as sternum, vertebra, liver and hilus. On ECT images, by contrast, abnormal uptake of the tumors was definitively detected in all the six cases. ECT imaging was also useful in estimating the effect of treatment by the decrease in 67 Ga concentration. We have devised a special technique to repeat ECT scan with a thin tube filled with 67 Ga solution inserted through the esophagus. By this technique, comparing paired images with and without the tube activity, exact location of the uptake against the esophagus and extraesophageal extension of the disease could be accurately evaluated in a three-dimensional field of view. ECT in gallium scanning is expected to be of great clinical value to elevate the confidence level of diagnosis in detecting, localizing and following up the diseases. (author)

Improving the quantitative accuracy of optical-emission computed tomography by incorporating an attenuation correction: application to HIF1 imaging

Science.gov (United States)

Kim, E.; Bowsher, J.; Thomas, A. S.; Sakhalkar, H.; Dewhirst, M.; Oldham, M.

2008-10-01

Optical computed tomography (optical-CT) and optical-emission computed tomography (optical-ECT) are new techniques for imaging the 3D structure and function (including gene expression) of whole unsectioned tissue samples. This work presents a method of improving the quantitative accuracy of optical-ECT by correcting for the 'self'-attenuation of photons emitted within the sample. The correction is analogous to a method commonly applied in single-photon-emission computed tomography reconstruction. The performance of the correction method was investigated by application to a transparent cylindrical gelatin phantom, containing a known distribution of attenuation (a central ink-doped gelatine core) and a known distribution of fluorescing fibres. Attenuation corrected and uncorrected optical-ECT images were reconstructed on the phantom to enable an evaluation of the effectiveness of the correction. Significant attenuation artefacts were observed in the uncorrected images where the central fibre appeared ~24% less intense due to greater attenuation from the surrounding ink-doped gelatin. This artefact was almost completely removed in the attenuation-corrected image, where the central fibre was within ~4% of the others. The successful phantom test enabled application of attenuation correction to optical-ECT images of an unsectioned human breast xenograft tumour grown subcutaneously on the hind leg of a nude mouse. This tumour cell line had been genetically labelled (pre-implantation) with fluorescent reporter genes such that all viable tumour cells expressed constitutive red fluorescent protein and hypoxia-inducible factor 1 transcription-produced green fluorescent protein. In addition to the fluorescent reporter labelling of gene expression, the tumour microvasculature was labelled by a light-absorbing vasculature contrast agent delivered in vivo by tail-vein injection. Optical-CT transmission images yielded high-resolution 3D images of the absorbing contrast agent, and

Improving the quantitative accuracy of optical-emission computed tomography by incorporating an attenuation correction: application to HIF1 imaging

International Nuclear Information System (INIS)

Kim, E; Bowsher, J; Thomas, A S; Sakhalkar, H; Dewhirst, M; Oldham, M

2008-01-01

Optical computed tomography (optical-CT) and optical-emission computed tomography (optical-ECT) are new techniques for imaging the 3D structure and function (including gene expression) of whole unsectioned tissue samples. This work presents a method of improving the quantitative accuracy of optical-ECT by correcting for the 'self'-attenuation of photons emitted within the sample. The correction is analogous to a method commonly applied in single-photon-emission computed tomography reconstruction. The performance of the correction method was investigated by application to a transparent cylindrical gelatin phantom, containing a known distribution of attenuation (a central ink-doped gelatine core) and a known distribution of fluorescing fibres. Attenuation corrected and uncorrected optical-ECT images were reconstructed on the phantom to enable an evaluation of the effectiveness of the correction. Significant attenuation artefacts were observed in the uncorrected images where the central fibre appeared ∼24% less intense due to greater attenuation from the surrounding ink-doped gelatin. This artefact was almost completely removed in the attenuation-corrected image, where the central fibre was within ∼4% of the others. The successful phantom test enabled application of attenuation correction to optical-ECT images of an unsectioned human breast xenograft tumour grown subcutaneously on the hind leg of a nude mouse. This tumour cell line had been genetically labelled (pre-implantation) with fluorescent reporter genes such that all viable tumour cells expressed constitutive red fluorescent protein and hypoxia-inducible factor 1 transcription-produced green fluorescent protein. In addition to the fluorescent reporter labelling of gene expression, the tumour microvasculature was labelled by a light-absorbing vasculature contrast agent delivered in vivo by tail-vein injection. Optical-CT transmission images yielded high-resolution 3D images of the absorbing contrast agent

Anti-amyloid-β-mediated positron emission tomography imaging in Alzheimer's disease mouse brains.

Directory of Open Access Journals (Sweden)

Daniel McLean

Full Text Available Antibody-mediated imaging of amyloid β (Aβ in Alzheimer's disease (AD offers a promising strategy to detect and monitor specific Aβ species, such as oligomers, that have important pathological and therapeutic relevance. The major current limitation of antibodies as a diagnostic and imaging device is poor blood-brain-barrier permeability. A classical anti-Aβ antibody, 6E10, is modified with 10 kDa polyethylene glycol (PEG and a positron emitting isotope, Copper-64 (t(½ = 12.7 h, and intravenously delivered to the TgCRND8 mouse model of Alzheimer's disease. Modification of 6E10 with PEG (6E10-PEG increases accumulation of 6E10 in brain tissue in both TgCRND8 and wild type control animals. 6E10-PEG differentiates TgCRND8 animals from wild type controls using positron emission tomography (PET and provides a framework for using antibodies to detect pathology using non-invasive medical imaging techniques.

Quantification in dynamic and small-animal positron emission tomography

NARCIS (Netherlands)

Disselhorst, Johannes Antonius

2011-01-01

This thesis covers two aspects of positron emission tomography (PET) quantification. The first section addresses the characterization and optimization of a small-animal PET/CT scanner. The sensitivity and resolution as well as various parameters affecting image quality (reconstruction settings, type

New detector developments for high resolution positron emission tomography

International Nuclear Information System (INIS)

Ziegler, S.I.; Pichler, B.; Lorenz, E.

1998-01-01

The strength of quantitative, functional imaging using positron emission tomography, specially in small animals, is limited due to the spatial resolution. Therefore, various tomograph designs employing new scintillators, light sensors, or coincidence electronic are investigated to improve resolution without losses in sensitivity. Luminous scintillators with short light decay time in combination with novel readout schemes using photomultipliers or semiconductor detectors are currently tested by several groups and are implemented in tomographs for small animals. This review summarises the state of development in high resolution positron emission tomography with a detailed description of a system incorporating avalanche photodiode arrays and small scintillation crystals. (orig.) [de

Contribution of positron emission tomography in pleural disease.

OpenAIRE

Duysinx, Bernard; Corhay, Jean-Louis; Larock, Marie-Paule; Withofs, Nadia; Bury, Thierry; Hustinx, Roland; Louis, Renaud

2010-01-01

INTRODUCTION: Positron emission tomography (PET) now plays a clear role in oncology, especially in chest tumours. We discuss the value of metabolic imaging in characterising pleural pathology in the light of our own experience and review the literature. BACKGROUND: PET is particularly useful in characterising malignant pleural pathologies and is a factor of prognosis in mesothelioma. Metabolic imaging also provides clinical information for staging lung cancer, in researching the primary tumou...

[¹⁸F]Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) in Suspected Recurrent Breast Cancer

DEFF Research Database (Denmark)

Hildebrandt, Malene Grubbe; Gerke, Oke; Baun, Christina

2016-01-01

PURPOSE: To prospectively investigate the diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) with dual-time-point imaging, contrast-enhanced CT (ceCT), and bone scintigraphy (BS) in patients with suspected breast cancer recurrence....... PATIENTS AND METHODS: One hundred women with suspected recurrence of breast cancer underwent 1-hour and 3-hour FDG-PET/CT, ceCT, and BS within approximately 10 days. The study was powered to estimate the precision of the individual imaging tests. Images were visually interpreted using a four...

2-deoxy-2-(18F)fluoro-D-glucose positron emission tomography/computed tomography imaging in paediatric oncology

Institute of Scientific and Technical Information of China (English)

John; Freebody; Eva; A; Wegner; Monica; A; Rossleigh

2014-01-01

Positron emission tomography(PET) is a minimally in-vasive technique which has been well validated for the diagnosis, staging, monitoring of response to therapy, and disease surveillance of adult oncology patients. Tra-ditionally the value of PET and PET/computed tomogra-phy(CT) hybrid imaging has been less clearly defined for paediatric oncology. However recent evidence has emerged regarding the diagnostic utility of these mo-dalities, and they are becoming increasingly important tools in the evaluation and monitoring of children with known or suspected malignant disease. Important indi-cations for 2-deoxy-2-(18F)fluoro-D-glucose(FDG) PET in paediatric oncology include lymphoma, brain tumours, sarcoma, neuroblastoma, Langerhans cell histiocytosis, urogenital tumours and neurofibromatosis type Ⅰ. This article aims to review current evidence for the use of FDG PET and PET/CT in these indications. Attention will also be given to technical and logistical issues, the description of common imaging pitfalls, and dosimetric concerns as they relate to paediatric oncology.

Methodology of the individual detection of cerebral activations by positrons emission tomography: statistical characterization of noise images and introduction of anatomical information; Methodologie de la detection individuelle d`activations cerebrales en tomographie par emission de positons: caracterisation statistique des images de bruit et introduction d`information anatomique

Energy Technology Data Exchange (ETDEWEB)

Antoine, M J

1996-10-23

The work that presented here has been done in the context of non invasive study of human brain, with metabolism images techniques ( positrons emission tomography or P.E.T.) and anatomy images techniques (imaging by nuclear magnetic resonance or MRI). The objective of this thesis was to use jointly, the information given by these two ways, in the aim of improving the individual detection of cerebral activation. (N.C.)

Single photon emission computerized tomography

International Nuclear Information System (INIS)

Hooge, P. de.

1983-01-01

In this thesis two single-photon emission tomographic techniques are presented: (a) longitudinal tomography with a rotating slanting-hole collimator, and (b) transversal tomography with a rotating gamma camera. These methods overcome the disadvantages of conventional scintigraphy. Both detection systems and the image construction methods are explained and comparisons with conventional scintigraphy are drawn. One chapter is dedicated to the determination of system parameters like spatial resolution, contrast, detector uniformity, and size of the object, by phantom studies. In separate chapters the results are presented of detection of tumors and metastases in the liver and the liver hilus; skeletal diseases; various pathological aberrations of the brain; and myocardial perfusion. The possible use of these two ect's for other organs and body areas is discussed in the last chapter. (Auth.)

Positron emission tomography basic sciences

CERN Document Server

Townsend, D W; Valk, P E; Maisey, M N

2003-01-01

Essential for students, science and medical graduates who want to understand the basic science of Positron Emission Tomography (PET), this book describes the physics, chemistry, technology and overview of the clinical uses behind the science of PET and the imaging techniques it uses. In recent years, PET has moved from high-end research imaging tool used by the highly specialized to an essential component of clinical evaluation in the clinic, especially in cancer management. Previously being the realm of scientists, this book explains PET instrumentation, radiochemistry, PET data acquisition and image formation, integration of structural and functional images, radiation dosimetry and protection, and applications in dedicated areas such as drug development, oncology, and gene expression imaging. The technologist, the science, engineering or chemistry graduate seeking further detailed information about PET, or the medical advanced trainee wishing to gain insight into the basic science of PET will find this book...

False-positive uptake on 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography/computed tomography (PET/CT) in oncological imaging

International Nuclear Information System (INIS)

Culverwell, A.D.; Scarsbrook, A.F.; Chowdhury, F.U.

2011-01-01

With the increasing utilization of integrated positron-emission tomography/computed tomography (PET/CT) using the glucose analogue 2-[ 18 F]-fluoro-2-deoxy-D-glucose (FDG) in oncological imaging, it is important for radiologists and nuclear medicine physicians to be aware that FDG uptake is not specific for malignancy, as many different physiological variants and benign pathological conditions can also exhibit increased glucose metabolism. Such false-positive FDG uptake often arises outside the area of primary interest and may mimic malignant disease, thereby confounding accurate interpretation of PET/CT studies. With the use of illustrative clinical cases, this article will provide a systematic overview of potential interpretative pitfalls and illustrate how such unexpected findings can be appropriately evaluated.

Positron Emission Tomography: Its 65 years

International Nuclear Information System (INIS)

Del Guerra, A.; Belcari, N.; Bisogni, M.

2016-01-01

Positron Emission Tomography (PET) is a well-established imaging technique for in vivo molecular imaging. In this review after a brief history of PET there are presented its physical principles and the technology that has been developed for bringing PET from a bench experiment to a clinical indispensable instrument. The limitations and performance of the PET tomographs are discussed, both as for the hardware and software aspects. The status of art of clinical, preclinical and hybrid scanners (i.e., PET/CT and PET/MR) is reported. Finally the actual trend and the recent and future technological developments are fully illustrated.

Electrocardiographic gating in positron emission computed tomography

International Nuclear Information System (INIS)

Hoffman, E.J.; Phelps, M.E.; Wisenberg, G.; Schelbert, H.R.; Kuhl, D.E.

1979-01-01

Electrocardiographic (ECG) synchronized multiple gated data acquisition was employed with positron emission computed tomography (ECT) to obtain images of myocardial blood pool and myocardium. The feasibility and requirements of multiple gated data acquisition in positron ECT were investigated for 13NH3, ( 18 F)-2-fluoro-2-D-deoxyglucose, and ( 11 C)-carboxyhemoglobin. Examples are shown in which image detail is enhanced and image interpretation is facilitated when ECG gating is employed in the data collection. Analysis of count rate data from a series of volunteers indicates that multiple, statistically adequate images can be obtained under a multiple gated data collection format without an increase in administered dose

Radiolabeled phosphonium salts as mitocondrial voltage sensors for positron emission tomography myocardial imaging agents

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Yon; Min, Jung Joon [Dept. of Nuclear Medicine,Chonnam National University Medical School and Hwasun Hospital, Gwangju (Korea, Republic of)

2016-09-15

Despite substantial advances in the diagnosis of cardiovascular disease, {sup 18}F-labeled positron emission tomography (PET) radiopharmaceuticals remain necessary to diagnose heart disease because clinical use of current PET tracers is limited by their short half-life. Lipophilic cations such as phosphonium salts penetrate the mitochondrial membranes and accumulate in mitochondria of cardiomyocytes in response to negative inner-transmembrane potentials. Radiolabeled tetraphenyl phosphonium cation derivatives have been developed as myocardial imaging agents for PET. In this review, a general overview of these radiotracers, including their radiosynthesis, in vivo characterization, and evaluation is provided and clinical perspectives are discussed.

Positron emission tomography in drug development and drug evaluation

NARCIS (Netherlands)

Paans, AMJ; Vaalburg, W

2000-01-01

Positron Emission Tomography (PET) is an imaging modality which can determine biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labeled with positron emitting radionuclides as C-11, N-13, O-15 and F-18 and by measuring the annihilation radiation

Emission computed tomography

International Nuclear Information System (INIS)

Budinger, T.F.; Gullberg, G.T.; Huesman, R.H.

1979-01-01

This chapter is devoted to the methods of computer assisted tomography for determination of the three-dimensional distribution of gamma-emitting radionuclides in the human body. The major applications of emission computed tomography are in biological research and medical diagnostic procedures. The objectives of these procedures are to make quantitative measurements of in vivo biochemical and hemodynamic functions

Synthesis of novel ligands for neuro-inflammation imaging using Positron Emission Tomography

International Nuclear Information System (INIS)

Cacheux, Fanny

2016-01-01

Neuro-inflammation plays an important role in many neuro-degenerative diseases (Alzheimer, Parkinson, Multiple sclerosis..) and recent developments in molecular imaging provide today new insights into the diagnostic and the treatment management of these diseases. Among the existing imaging techniques, the highly sensitive and quantitative nuclear modalities SPECT (single photon emission computed tomography) but especially PET (positron emission tomography) play key roles. My PhD program is devoted to the design and synthesis of novel radioligands, all dedicated to the imaging of specific targets and processes linked to neuro-inflammation. For this, PET and the short-lived positron-emitter fluorine-18 (T 1/2 : 109.8 min) remain the main focuses. The project has been divided into two sections, the first one concentrates on the development of novel ligands targeting the Translocator Protein 18 kDa (TSPO). Indeed, this target is today recognized as an early bio-marker of neuro-inflammatory processes and PK11195, an isoquinoline carboxamide labelled with carbon-11, was, in the late 80's, the first reported PET-radioligand. More recently, new compounds, all belonging to different chemical classes, have emerged and notably the pyrazolopyrimidine acetamide [ 11 C]DPA-713 and the pyridazinoindole acetamide [ 11 C]SSR180575. Within the first section of my PhD, novel derivatives of both DPA-713 and SSR180575 have been synthesized and in vitro characterized. Dedicated precursors for labelling were also developed for the most promising candidates, and radiolabelling has been performed. Some results have been presented at the 21. International Symposium on Radiopharmaceutical Sciences (Columbia, MO, USA - May 26-31, 2015).The second part of my PhD, deals with the development of ligands for alternative targets to the TSPO, like the type-2 cannabinoid receptor (CB2R) and the purinergic P2Y14/P2Y12 receptors, the latter emerging today as a hot topic for imaging opportunities

[The value of multimodal imaging by single photon emission computed tomography associated to X ray computed tomography (SPECT-CT) in the management of differentiated thyroid carcinoma: about 156 cases].

Science.gov (United States)

Mhiri, Aida; El Bez, Intidhar; Slim, Ihsen; Meddeb, Imène; Yeddes, Imene; Ghezaiel, Mohamed; Gritli, Saïd; Ben Slimène, Mohamed Faouzi

2013-10-01

Single photon emission computed tomography combined with a low dose computed tomography (SPECT-CT), is a hybrid imaging integrating functional and anatomical data. The purpose of our study was to evaluate the contribution of the SPECTCT over traditional planar imaging of patients with differentiated thyroid carcinoma (DTC). Post therapy 131IWhole body scan followed by SPECTCT of the neck and thorax, were performed in 156 patients with DTC. Among these 156 patients followed for a predominantly papillary, the use of fusion imaging SPECT-CT compared to conventional planar imaging allowed us to correct our therapeutic approach in 26.9 % (42/156 patients), according to the protocols of therapeutic management of our institute. SPECT-CT is a multimodal imaging providing better identification and more accurate anatomic localization of the foci of radioiodine uptake with impact on therapeutic management.

Methods for modeling and quantification in functional imaging by positron emissions tomography and magnetic resonance imaging

International Nuclear Information System (INIS)

Costes, Nicolas

2017-01-01

This report presents experiences and researches in the field of in vivo medical imaging by positron emission tomography (PET) and magnetic resonance imaging (MRI). In particular, advances in terms of reconstruction, quantification and modeling in PET are described. The validation of processing and analysis methods is supported by the creation of data by simulation of the imaging process in PET. The recent advances of combined PET/MRI clinical cameras, allowing simultaneous acquisition of molecular/metabolic PET information, and functional/structural MRI information opens the door to unique methodological innovations, exploiting spatial alignment and simultaneity of the PET and MRI signals. It will lead to an increase in accuracy and sensitivity in the measurement of biological phenomena. In this context, the developed projects address new methodological issues related to quantification, and to the respective contributions of MRI or PET information for a reciprocal improvement of the signals of the two modalities. They open perspectives for combined analysis of the two imaging techniques, allowing optimal use of synchronous, anatomical, molecular and functional information for brain imaging. These innovative concepts, as well as data correction and analysis methods, will be easily translated into other areas of investigation using combined PET/MRI. (author) [fr

Use of positron emission tomography in colorectal cancer

International Nuclear Information System (INIS)

Gonzalez E, Patricio; Jofre E, Josefina; Massardo V, Teresa; Humeres, Pamela; Canessa G, Jose; Sierralta C, Paulina

2002-01-01

The value of PET (Positron Emission Tomography) in colorectal cancer is presented. PET is a novel technique that uses F-18-FDG (fluorodeoxiglucose) to assess glucose metabolism by whole body imaging. It has been demonstrated that malignant cells have both increase of glucose uptake and utilization. In colorectal cancer, PET is indicated for staging, assess recurrence, liver metastasis and treatment follow-up. PET is more sensitive and specific than CT (Computed Tomography) and is cost effective. In 30% of cases PET may change patient management, avoiding unnecessary procedures (au)

Use of antimatter for the in vivo investigation of the brain: positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Syrota, A. [CEA, 75 - Paris (France)

2002-07-01

This series of slides presents 3 imaging methods used in medicine: - the single photon emission computed tomography (SPECT), the positron emission tomography (PET), and the functional magnetic resonance imaging (FMRI). The presentation begins with a brief historical description that highlights the narrow link between progress in imaging techniques and the technological development in radiation detection and computer sciences. Another aspect is the parallel and necessary development of isotopic tracers along with imaging techniques. The clinical applications of PET and FMRI concerning either normal brain functions such as calculus or consciousness or diseases affecting the central nervous system such as Parkinson's disease or schizophrenia (trough the study of the pathways of dopamine in the brain) are presented.

Imaging local brain function with emission computed tomography

International Nuclear Information System (INIS)

Kuhl, D.E.

1984-01-01

Positron emission tomography (PET) using 18 F-fluorodeoxyglucose (FDG) was used to map local cerebral glucose utilization in the study of local cerebral function. This information differs fundamentally from structural assessment by means of computed tomography (CT). In normal human volunteers, the FDG scan was used to determine the cerebral metabolic response to conrolled sensory stimulation and the effects of aging. Cerebral metabolic patterns are distinctive among depressed and demented elderly patients. The FDG scan appears normal in the depressed patient, studded with multiple metabolic defects in patients with multiple infarct dementia, and in the patients with Alzheimer disease, metabolism is particularly reduced in the parietal cortex, but only slightly reduced in the caudate and thalamus. The interictal FDG scan effectively detects hypometabolic brain zones that are sites of onset for seizures in patients with partial epilepsy, even though these zones usually appear normal on CT scans. The future prospects of PET are discussed

Evaluation of scintillators and semiconductor detectors to image three-photon positron annihilation for positron emission tomography

International Nuclear Information System (INIS)

Abuelhia, E.; Spyrou, N.M.; Kacperski, K.; College University, Middlesex Hospital, London

2008-01-01

Positron emission tomography (PET) is rapidly becoming the main nuclear imaging modality of the present century. The future of PET instrumentation relies on semiconductor detectors because of their excellent characteristics. Three-photon positron annihilation has been recently investigated as a novel imaging modality, which demands the crucial high energy resolution of semiconductor detector. In this work the evaluation of the NaI(Tl) scintillator and HPGe and CdZTe semiconductor detectors, to construct a simple three-photon positron annihilation scanner has been explored. The effect of detector and scanner size on spatial resolution (FWHM) is discussed. The characteristics: energy resolution versus count rate and point-spread function of the three-photon positron annihilation image profile from triple coincidence measurements were investigated. (author)

{sup 11}C-Methionine positron emission tomography may monitor the activity of encephalitis

Energy Technology Data Exchange (ETDEWEB)

Hirata, Kenji; Shiga, Tohru; Manabe, Osamu; Tamaki, Nagara [Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Sapporo (Japan)], E-mail: khirata@med.hokudai.ac.jp; Fujima, Noriyuki [Department of Radiology, Graduate School of Medicine, Hokkaido University, Sapporo (Japan); Usui, Reiko [Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Sapporo (Japan); Department of Psychiatry, Graduate School of Medicine, Hokkaido University, Sapporo (Japan); Kuge, Yuji [Central Institute of Isotope Science, Hokkaido University, Sapporo (Japan)

2012-12-15

Encephalitis is generally diagnosed by clinical symptoms, cerebrospinal fluid examination, and imaging studies including CT, magnetic resonance imaging (MRI), and perfusion single photon emission tomography (SPECT). However, the role of positron emission tomography (PET) in diagnosis of encephalitis remains unclear. A 49-year-old woman presenting with coma and elevated inflammatory reaction was diagnosed as having encephalitis according to slow activity on electroencephalogram, broad cortical lesion in MR fluid attenuated inversion recovery image, and increased blood flow demonstrated by SPECT. PET revealed increased accumulation of {sup 11}C-methionine (MET) in the affected brain tissues. After the symptom had improved 2 months later, the accumulation of MET as well as the abnormal findings of MR imaging and SPECT was normalized. This case indicated that MET PET may monitor the activity of encephalitis.

An interior-point method for total variation regularized positron emission tomography image reconstruction

Science.gov (United States)

Bai, Bing

2012-03-01

There has been a lot of work on total variation (TV) regularized tomographic image reconstruction recently. Many of them use gradient-based optimization algorithms with a differentiable approximation of the TV functional. In this paper we apply TV regularization in Positron Emission Tomography (PET) image reconstruction. We reconstruct the PET image in a Bayesian framework, using Poisson noise model and TV prior functional. The original optimization problem is transformed to an equivalent problem with inequality constraints by adding auxiliary variables. Then we use an interior point method with logarithmic barrier functions to solve the constrained optimization problem. In this method, a series of points approaching the solution from inside the feasible region are found by solving a sequence of subproblems characterized by an increasing positive parameter. We use preconditioned conjugate gradient (PCG) algorithm to solve the subproblems directly. The nonnegativity constraint is enforced by bend line search. The exact expression of the TV functional is used in our calculations. Simulation results show that the algorithm converges fast and the convergence is insensitive to the values of the regularization and reconstruction parameters.

Laparoscopic Scar: a mimicker of Sister Mary Joseph's nodule on positron emission tomography/CT

International Nuclear Information System (INIS)

Setty, B.; Blake, M.A.; Holalkere, N.S.; Blaszkowsky, L.S.; Fischman, A.

2006-01-01

Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. 18 F -fluoro-2-deoxy-D-glucose (FDG) is the most commonly used radiotracer in positron emission tomography/CT. It is a tumour viability agent and usually its uptake within a lesion reflects the presence of a viable tumour tissue. However, false-positive FDG uptake is known to occur in benign processes of either inflammatory or infectious aetiology. We describe FDG uptake at the site of laparoscopic scar that mimicked Sister Mary Joseph's nodule in a patient with gastric adenocarcinoma. Here, the knowledge of the patient's history and subtle imaging findings helped in accurate staging of the patient. In this case report, we emphasize the value of the knowledge of the patient history and awareness of different pitfalls of FDG to achieve a correct diagnosis on positron emission tomography/CT

Multimodal imaging analysis of single-photon emission computed tomography and magnetic resonance tomography for improving diagnosis of Parkinson's disease

International Nuclear Information System (INIS)

Barthel, H.; Georgi, P.; Slomka, P.; Dannenberg, C.; Kahn, T.

2000-01-01

Parkinson's disease (PD) is characterized by a degeneration of nigrostriated dopaminergic neurons, which can be imaged with 123 I-labeled 2β-carbomethoxy-3β-(4-iodophenyl) tropane ([ 123 I]β-CIT) and single-photon emission computed tomography (SPECT). However, the quality of the region of interest (ROI) technique used for quantitative analysis of SPECT data is compromised by limited anatomical information in the images. We investigated whether the diagnosis of PD can be improved by combining the use of SPECT images with morphological image data from magnetic resonance imaging (MRI)/computed tomography (CT). We examined 27 patients (8 men, 19 women; aged 55±13 years) with PD (Hoehn and Yahr stage 2.1±0.8) by high-resolution [ 123 I]β-CIT SPECT (185-200 MBq, Ceraspect camera). SPECT images were analyzed both by a unimodal technique (ROIs defined directly within the SPECT studies) and a multimodal technique (ROIs defined within individual MRI/CT studies and transferred to the corresponding interactively coregistered SPECT studies). [ 123 I]β-CIT binding ratios (cerebellum as reference), which were obtained for heads of caudate nuclei (CA), putamina (PU), and global striatal structures were compared with clinical parameters. Differences between contra- and ipsilateral (related to symptom dominance) striatal [ 123 I]β-CIT binding ratios proved to be larger in the multimodal ROI technique than in the unimodal approach (e.g., for PU: 1.2*** vs. 0.7**). Binding ratios obtained by the unimodal ROI technique were significantly correlated with those of the multimodal technique (e.g., for CA: y=0.97x+2.8; r=0.70; P com subscore (r=-0.49* vs. -0.32). These results show that the impact of [ 123 I]β-CIT SPECT for diagnosing PD is affected by the method used to analyze the SPECT images. The described multimodal approach, which is based on coregistration of SPECT and morphological imaging data, leads to improved determination of the degree of this dopaminergic disorder

Methodology of the individual detection of cerebral activations by positrons emission tomography: statistical characterization of noise images and introduction of anatomical information

International Nuclear Information System (INIS)

Antoine, M.J.

1996-01-01

The work that presented here has been done in the context of non invasive study of human brain, with metabolism images techniques ( positrons emission tomography or P.E.T.) and anatomy images techniques (imaging by nuclear magnetic resonance or MRI). The objective of this thesis was to use jointly, the information given by these two ways, in the aim of improving the individual detection of cerebral activation. (N.C.)

Multimodality Imaging Probe for Positron Emission Tomography and Fluorescence Imaging Studies

Directory of Open Access Journals (Sweden)

Suresh K. Pandey

2014-05-01

Full Text Available Our goal is to develop multimodality imaging agents for use in cell tracking studies by positron emission tomography (PET and optical imaging (OI. For this purpose, bovine serum albumin (BSA was complexed with biotin (histologic studies, 5(6- carboxyfluorescein, succinimidyl ester (FAM SE (OI studies, and diethylenetriamine pentaacetic acid (DTPA for chelating gallium 68 (PET studies. For synthesis of BSA-biotin-FAM-DTPA, BSA was coupled to (+-biotin N-hydroxysuccinimide ester (biotin-NHSI. BSA- biotin was treated with DTPA-anhydride and biotin-BSA-DTPA was reacted with FAM. The biotin-BSA-DTPA-FAM was reacted with gallium chloride 3 to 5 mCi eluted from the generator using 0.1 N HCl and was passed through basic resin (AG 11 A8 and 150 mCi (100 μL, pH 7–8 was incubated with 0.1 mg of FAM conjugate (100 μL at room temperature for 15 minutes to give 66Ga-BSA-biotin-DTPA-FAM. A shaved C57 black mouse was injected with FAM conjugate (50 μL at one flank and FAM-68Ga (50 μL, 30 mCi at the other. Immediately after injection, the mouse was placed in a fluorescence imaging system (Kodak In-Vivo F, Bruker Biospin Co., Woodbridge, CT and imaged (Λex: 465 nm, Λem: 535 nm, time: 8 seconds, Xenon Light Source, Kodak. The same mouse was then placed under an Inveon microPET scanner (Siemens Medical Solutions, Knoxville, TN injected (intravenously with 25 μCi of 18F and after a half-hour (to allow sufficient bone uptake was imaged for 30 minutes. Molecular weight determined using matrix-associated laser desorption ionization (MALDI for the BSA sample was 66,485 Da and for biotin-BSA was 67,116 Da, indicating two biotin moieties per BSA molecule; for biotin-BSA-DTPA was 81,584 Da, indicating an average of 30 DTPA moieties per BSA molecule; and for FAM conjugate was 82,383 Da, indicating an average of 1.7 fluorescent moieties per BSA molecule. Fluorescence imaging clearly showed localization of FAM conjugate and FAM-68Ga at respective flanks of the mouse

Two-dimensional restoration of single photon emission computed tomography images using the Kalman filter

International Nuclear Information System (INIS)

Boulfelfel, D.; Rangayyan, R.M.; Kuduvalli, G.R.; Hahn, L.J.; Kloiber, R.

1994-01-01

The discrete filtered backprojection (DFBP) algorithm used for the reconstruction of single photon emission computed tomography (SPECT) images affects image quality because of the operations of filtering and discretization. The discretization of the filtered backprojection process can cause the modulation transfer function (MTF) of the SPECT imaging system to be anisotropic and nonstationary, especially near the edges of the camera's field of view. The use of shift-invariant restoration techniques fails to restore large images because these techniques do not account for such variations in the MTF. This study presents the application of a two-dimensional (2-D) shift-variant Kalman filter for post-reconstruction restoration of SPECT slices. This filter was applied to SPECT images of a hollow cylinder phantom; a resolution phantom; and a large, truncated cone phantom containing two types of cold spots, a sphere, and a triangular prism. The images were acquired on an ADAC GENESYS camera. A comparison was performed between results obtained by the Kalman filter and those obtained by shift-invariant filters. Quantitative analysis of the restored images performed through measurement of root mean squared errors shows a considerable reduction in error of Kalman-filtered images over images restored using shift-invariant methods

A general class of preconditioners for statistical iterative reconstruction of emission computed tomography

International Nuclear Information System (INIS)

Chinn, G.; Huang, S.C.

1997-01-01

A major drawback of statistical iterative image reconstruction for emission computed tomography is its high computational cost. The ill-posed nature of tomography leads to slow convergence for standard gradient-based iterative approaches such as the steepest descent or the conjugate gradient algorithm. In this paper new theory and methods for a class of preconditioners are developed for accelerating the convergence rate of iterative reconstruction. To demonstrate the potential of this class of preconditioners, a preconditioned conjugate gradient (PCG) iterative algorithm for weighted least squares reconstruction (WLS) was formulated for emission tomography. Using simulated positron emission tomography (PET) data of the Hoffman brain phantom, it was shown that the convergence rate of the PCG can reduce the number of iterations of the standard conjugate gradient algorithm by a factor of 2--8 times depending on the convergence criterion

Image reconstruction using three-dimensional compound Gauss-Markov random field in emission computed tomography

International Nuclear Information System (INIS)

Watanabe, Shuichi; Kudo, Hiroyuki; Saito, Tsuneo

1993-01-01

In this paper, we propose a new reconstruction algorithm based on MAP (maximum a posteriori probability) estimation principle for emission tomography. To improve noise suppression properties of the conventional ML-EM (maximum likelihood expectation maximization) algorithm, direct three-dimensional reconstruction that utilizes intensity correlations between adjacent transaxial slices is introduced. Moreover, to avoid oversmoothing of edges, a priori knowledge of RI (radioisotope) distribution is represented by using a doubly-stochastic image model called the compound Gauss-Markov random field. The a posteriori probability is maximized by using the iterative GEM (generalized EM) algorithm. Computer simulation results are shown to demonstrate validity of the proposed algorithm. (author)

Variabilities of Magnetic Resonance Imaging-, Computed Tomography-, and Positron Emission Tomography-Computed Tomography-Based Tumor and Lymph Node Delineations for Lung Cancer Radiation Therapy Planning.

Science.gov (United States)

Karki, Kishor; Saraiya, Siddharth; Hugo, Geoffrey D; Mukhopadhyay, Nitai; Jan, Nuzhat; Schuster, Jessica; Schutzer, Matthew; Fahrner, Lester; Groves, Robert; Olsen, Kathryn M; Ford, John C; Weiss, Elisabeth

2017-09-01

To investigate interobserver delineation variability for gross tumor volumes of primary lung tumors and associated pathologic lymph nodes using magnetic resonance imaging (MRI), and to compare the results with computed tomography (CT) alone- and positron emission tomography (PET)-CT-based delineations. Seven physicians delineated the tumor volumes of 10 patients for the following scenarios: (1) CT only, (2) PET-CT fusion images registered to CT ("clinical standard"), and (3) postcontrast T1-weighted MRI registered with diffusion-weighted MRI. To compute interobserver variability, the median surface was generated from all observers' contours and used as the reference surface. A physician labeled the interface types (tumor to lung, atelectasis (collapsed lung), hilum, mediastinum, or chest wall) on the median surface. Contoured volumes and bidirectional local distances between individual observers' contours and the reference contour were analyzed. Computed tomography- and MRI-based tumor volumes normalized relative to PET-CT-based volumes were 1.62 ± 0.76 (mean ± standard deviation) and 1.38 ± 0.44, respectively. Volume differences between the imaging modalities were not significant. Between observers, the mean normalized volumes per patient averaged over all patients varied significantly by a factor of 1.6 (MRI) and 2.0 (CT and PET-CT) (P=4.10 × 10 -5 to 3.82 × 10 -9 ). The tumor-atelectasis interface had a significantly higher variability than other interfaces for all modalities combined (P=.0006). The interfaces with the smallest uncertainties were tumor-lung (on CT) and tumor-mediastinum (on PET-CT and MRI). Although MRI-based contouring showed overall larger variability than PET-CT, contouring variability depended on the interface type and was not significantly different between modalities, despite the limited observer experience with MRI. Multimodality imaging and combining different imaging characteristics might be the best approach to define

18 F-sodium fluoride positron emission tomography of the equine distal limb: Exploratory study in three horses.

Science.gov (United States)

Spriet, M; Espinosa, P; Kyme, A Z; Phillips, K L; Katzman, S A; Galuppo, L D; Stepanov, P; Beylin, D

2018-01-01

Positron emission tomography (PET) is a cross-sectional, functional imaging modality that has recently become available to the horse. The use of 18 F-sodium fluoride ( 18 F-NaF), a PET bone tracer, has not previously been reported in this species. To assess the feasibility of 18 F-NaF PET in the equine distal limb and explore possible applications in the horse in comparison with other imaging modalities. Exploratory descriptive study involving three research horses. Horses were placed under general anaesthesia prior to intravenous (i.v.) administration of 1.5 MBq/kg of 18 F-NaF. Positron emission tomography imaging of both front feet and fetlocks was performed using a portable scanner. Computed tomography (CT) of the distal limb was performed under a separate anaesthetic episode. Bone scintigraphy and magnetic resonance imaging (MRI) were subsequently performed under standing sedation. Images obtained from PET and other imaging modalities were independently assessed and the results correlated. Positron emission tomography images were obtained without complication. The radiation exposure rate was similar to equine bone scintigraphy. Positron emission tomography detected focal 18 F-NaF uptake in areas where other imaging modalities did not identify any abnormalities. This included sites of ligamentous attachment, subchondral compact bone plate and the flexor cortex of the navicular bone. 18 F-NaF uptake was identified in some, but not all, osseous fragments and areas of osseous formation, suggesting a distinction between active and inactive lesions. A small number of horses were included and histopathology was not available. 18 F-NaF PET imaging of the equine distal limb provides useful additional information when compared with CT, MRI and scintigraphy and has the potential for both research and clinical applications in the horse. The Summary is available in Chinese - see Supporting information. © 2017 EVJ Ltd.

21 CFR 892.1200 - Emission computed tomography system.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Emission computed tomography system. 892.1200... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1200 Emission computed tomography system. (a) Identification. An emission computed tomography system is a device intended to detect the...

Computed tomography and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography findings in adrenal candidiasis and histoplasmosis: two cases.

Science.gov (United States)

Altinmakas, Emre; Guo, Ming; Kundu, Uma R; Habra, Mouhammed Amir; Ng, Chaan

2015-01-01

We report the contrast-enhanced computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography findings in adrenal histoplasmosis and candidiasis. Both demonstrated bilateral hypermetabolic heterogeneous adrenal masses with limited wash-out on delayed CT. Adrenal candidiasis has not been previously reported, nor have the CT wash-out findings in either infection. The adrenal imaging findings are indistinguishable from malignancy, which is more common; but in this setting, physicians should be alert to the differential diagnosis of fungal infections, since it can be equally deadly. Published by Elsevier Inc.

Single-photon emission computed tomography/computed tomography in lung cancer and malignant lymphoma.

Science.gov (United States)

Schillaci, Orazio

2006-10-01

In nuclear oncology, despite the fast-growing diffusion of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET), single-photon emission computed tomography (SPECT) studies can still play an useful clinical role in several applications. The main limitation of SPECT imaging with tumor-seeking agents is the lack of the structural delineation of the pathologic processes they detect; this drawback sometimes renders SPECT interpretation difficult and can diminish its diagnostic accuracy. Fusion with morphological studies can overcome this limitation by giving an anatomical map to scintigraphic data. In the past, software-based fusion of independently performed SPECT and CT images proved to be time-consuming and impractical for routine use. The recent development of dual-modality integrated imaging systems that provide functional (SPECT) and anatomical (CT) images in the same scanning session, with the acquired images coregistered by means of the hardware, has opened a new era in this field. The first reports indicate that SPECT/CT is very useful in cancer imaging because it is able to provide further information of clinical value in several cases. In SPECT, studies of lung cancer and malignant lymphomas using different radiopharmaceutical, hybrid images are of value in providing the correct localization of tumor sites, with a precise detection of the involved organs, and the definition of their functional status, and in allowing the exclusion of disease in sites of physiologic tracer uptake. Therefore, in lung cancer and lymphomas, hybrid SPECT/CT can play a role in the diagnosis of the primary tumor, in the staging of the disease, in the follow-up, in the monitoring of therapy, in the detection of recurrence, and in dosimetric estimations for target radionuclide therapy.

Positron Emission Tomography Imaging Using Radiolabeled Inorganic Nanomaterials

Science.gov (United States)

Sun, Xiaolian; Cai, Weibo; Chen, Xiaoyuan

2015-01-01

CONSPECTUS Positron emission tomography (PET) is a radionuclide imaging technology that plays an important role in preclinical and clinical research. With administration of a small amount of radiotracer, PET imaging can provide a noninvasive, highly sensitive, and quantitative readout of its organ/tissue targeting efficiency and pharmacokinetics. Various radiotracers have been designed to target specific molecular events. Compared with antibodies, proteins, peptides, and other biologically relevant molecules, nanoparticles represent a new frontier in molecular imaging probe design, enabling the attachment of different imaging modalities, targeting ligands, and therapeutic payloads in a single vector. We introduce the radiolabeled nanoparticle platforms that we and others have developed. Due to the fundamental differences in the various nanoparticles and radioisotopes, most radiolabeling methods are designed case-by-case. We focus on some general rules about selecting appropriate isotopes for given types of nanoparticles, as well as adjusting the labeling strategies according to specific applications. We classified these radiolabeling methods into four categories: (1) complexation reaction of radiometal ions with chelators via coordination chemistry; (2) direct bombardment of nanoparticles via hadronic projectiles; (3) synthesis of nanoparticles using a mixture of radioactive and nonradioactive precursors; (4) chelator-free postsynthetic radiolabeling. Method 1 is generally applicable to different nanomaterials as long as the surface chemistry is well-designed. However, the addition of chelators brings concerns of possible changes to the physicochemical properties of nanomaterials and detachment of the radiometal. Methods 2 and 3 have improved radiochemical stability. The applications are, however, limited by the possible damage to the nanocomponent caused by the proton beams (method 2) and harsh synthetic conditions (method 3). Method 4 is still in its infancy

Development of radiotracers for imaging NR2B subtype NMDA receptors with positron emission tomography; Developpement de radiotraceurs pour la visualisation des recepteurs NMDA de sous-type NR2B par tomographie par emission de positons

Energy Technology Data Exchange (ETDEWEB)

Labas, R

2007-07-01

The aim of this thesis was to develop new radioactive tracers for imaging NR2B subtype NMDA receptors with positron emission tomography. Several compounds including 4-(4-fluoro-benzyl)piperidine and presenting interesting in vivo biological properties were the object of a labelling with a positrons emitter atom ({sup 11}C or {sup 18}F)

Ultrasound, elastography, and fluorodeoxyglucose positron emission tomography/computed tomography imaging in Riedel's thyroiditis: report of two cases.

Science.gov (United States)

Slman, Rouba; Monpeyssen, Hervé; Desarnaud, Serge; Haroche, Julien; Fediaevsky, Laurence Du Pasquier; Fabrice, Menegaux; Seret-Begue, Dominique; Amoura, Zahir; Aurengo, André; Leenhardt, Laurence

2011-07-01

Riedel's thyroiditis (RT) is a rare disease characterized by a chronic inflammatory lesion of the thyroid gland with invasion by a dense fibrosis. Publications of the imaging features of RT are scarce. To our knowledge, ultrasound elastography (USE) findings have not been previously reported. Therefore, we describe two patients with RT who were imaged with ultrasonography (US), USE, and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT). Two women were referred for a large, hard goiter with compressive symptoms (dyspnea and dysphagia); in one patient, the goiter was associated with retroperitoneal fibrosis. In both cases, RT was confirmed by surgical biopsy with pathological examination. Thyroid US imaging was performed with a US scan and a 10-13 MHz linear transducer. The hardness of the tissues was analyzed using transient USE (ShearWave, Aixplorer-SuperSonic Imagine). PET/CT scanning was performed with a Philips Gemini GXL camera (GE Medical Systems). In the first patient, US examination revealed a compressive multinodular goiter with large solid hypoechoic and poorly vascularized areas adjacent to the nodules. The predominant right nodule was hypoechoic with irregular margins. The second patient had a hypoechoic goiter with large bilateral hypoechoic areas. In both cases, an unusual feature was observed: the presence of tissue surrounding the primitive carotid artery, associated with thrombi of the internal jugular vein. Further, USE showed heterogeneity in the stiffness values of the thyroid parenchyma varying between 21 kPa and 281 kPa. FDG-PET/CT imaging showed uptake foci in the thyroid gland. In both cases, US showed a decrease in the thyroid gland volume and the disappearance of encasement of the neck vasculature in response to corticosteroid treatment. In contrast, the FDG-PET/CT features remained unchanged. US features, such as vascular encasement and improvement under corticosteroid treatment, seem to be specific to this

Clinical applications of positron emission tomography in breast cancer patients

International Nuclear Information System (INIS)

Roemer, W.; Avril, N.; Schwaiger, M.

1997-01-01

Increased glucose metabolism by malignant tissue can be visualized with positron emission tomography (PET), using the radiolabeled glucose analogue F-18 fluorodeoxyglucose (FDG). Depending on the criteria of image interpretation FDG-PET allows detection of breast cancer with a sensitivity of 68% to 94 % and a specificity of 84 % to 97 %. However, sensitivity to visualize small tumors (< 1 cm) is limited. Positron emission tomography demonstrates tumor involvement of regional lymph nodes with high accuracy, predominantly in patients with advanced breast cancer. The sensitivity for the detection of axillary lymph node metastases was 79% with a corresponding specificity of 96 %. Lymph node metastases could not be identified in four of six patients with small primary breast cancer (stage pT1), resulting in a sensitivity of only 33% in these patients. By visualizing primary tumors and metastases in one imaging procedure, PET imaging may allow the effective staging of breast cancer patients. Further studies are needed to define the role of scintigraphic techniques for the diagnostic work-up in patients. (author)

Magnetic resonance imaging-guided attenuation and scatter corrections in three-dimensional brain positron emission tomography

CERN Document Server

Zaidi, H; Slosman, D O

2003-01-01

Reliable attenuation correction represents an essential component of the long chain of modules required for the reconstruction of artifact-free, quantitative brain positron emission tomography (PET) images. In this work we demonstrate the proof of principle of segmented magnetic resonance imaging (MRI)-guided attenuation and scatter corrections in 3D brain PET. We have developed a method for attenuation correction based on registered T1-weighted MRI, eliminating the need of an additional transmission (TX) scan. The MR images were realigned to preliminary reconstructions of PET data using an automatic algorithm and then segmented by means of a fuzzy clustering technique which identifies tissues of significantly different density and composition. The voxels belonging to different regions were classified into air, skull, brain tissue and nasal sinuses. These voxels were then assigned theoretical tissue-dependent attenuation coefficients as reported in the ICRU 44 report followed by Gaussian smoothing and additio...

Concept of an upright wearable positron emission tomography imager in humans.

Science.gov (United States)

Bauer, Christopher E; Brefczynski-Lewis, Julie; Marano, Gary; Mandich, Mary-Beth; Stolin, Alexander; Martone, Peter; Lewis, James W; Jaliparthi, Gangadhar; Raylman, Raymond R; Majewski, Stan

2016-09-01

Positron Emission Tomography (PET) is traditionally used to image patients in restrictive positions, with few devices allowing for upright, brain-dedicated imaging. Our team has explored the concept of wearable PET imagers which could provide functional brain imaging of freely moving subjects. To test feasibility and determine future considerations for development, we built a rudimentary proof-of-concept prototype (Helmet_PET) and conducted tests in phantoms and four human volunteers. Twelve Silicon Photomultiplier-based detectors were assembled in a ring with exterior weight support and an interior mechanism that could be adjustably fitted to the head. We conducted brain phantom tests as well as scanned four patients scheduled for diagnostic F(18-) FDG PET/CT imaging. For human subjects the imager was angled such that field of view included basal ganglia and visual cortex to test for typical resting-state pattern. Imaging in two subjects was performed ~4 hr after PET/CT imaging to simulate lower injected F(18-) FDG dose by taking advantage of the natural radioactive decay of the tracer (F(18) half-life of 110 min), with an estimated imaging dosage of 25% of the standard. We found that imaging with a simple lightweight ring of detectors was feasible using a fraction of the standard radioligand dose. Activity levels in the human participants were quantitatively similar to standard PET in a set of anatomical ROIs. Typical resting-state brain pattern activation was demonstrated even in a 1 min scan of active head rotation. To our knowledge, this is the first demonstration of imaging a human subject with a novel wearable PET imager that moves with robust head movements. We discuss potential research and clinical applications that will drive the design of a fully functional device. Designs will need to consider trade-offs between a low weight device with high mobility and a heavier device with greater sensitivity and larger field of view.

Positron emission tomography in oncology

International Nuclear Information System (INIS)

Lecomte, R.; Bentourkia, M.; Benard, F.

2002-01-01

Positron Emission Tomography is a sophisticated molecular imaging technique, using a special scanner, that displays the functional status of tissues in the body at the cellular level (their metabolism). It is a diagnostic scan that provides the physician with information not available with traditional anatomic studies such as CT or MRI. PET can detect changes in cell function (disease) long before they are evident as physical (anatomic) changes seen on CT or MRI. In this way PET can add important information about many diseases allowing the physician to make a diagnosis often much earlier than with anatomic imaging techniques such as CT or MRI alone. In addition, in cases where an abnormality is noted on CT or MRI, PET can help differentiate benign changes from changes due to disease. PET scanning also typically images the entire body, unlike CT/MRI which is usually broken up into specific limited body section scans. All cells use glucose as an energy source but cancer cells use much more since they are growing much faster and out of control. This is the basis of imaging with F-18 FDG glucose, the radiotracer agent use in a PET oncology study. The abnormal, accelerated glucose used by cancer cells is detected by the PET scanner that processes the emissions from the F-18 FDG glucose by abnormally high levels of metabolism (tumor)

Positron emission tomography and migraine. Tomographie par emission de positons et migraine

Energy Technology Data Exchange (ETDEWEB)

Chabriat, H. (CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot)

1992-04-01

Positron emission tomography (PET) is a brain imaging technique that allows in vivo studies of numerous physiological parameters. There have been few PET studies in migraine patients. Cerebral blood flow changes with no variations in brain oxygen consumption have been reported in patients with prolonged neurologic manifestations during migraine attacks. Parenteral administration of reserpine during migraine headache has been followed by a fall in the overall cerebral uptake of glucose. The small sample sizes and a number of methodologic problems complicate the interpretation of these results. Recent technical advances and the development of new PET tracers can be expected to provide further insight into the pathophysiology of migraine. Today cerebral cortex 5 HT{sub 2} serotonin receptors can be studied in migraine patients with PET.

18 F-fluorodeoxyglucose positron emission tomography-computed tomography for preoperative lymph node staging in patients undergoing radical cystectomy for bladder cancer: a prospective study.

Science.gov (United States)

Hitier-Berthault, Maryam; Ansquer, Catherine; Branchereau, Julien; Renaudin, Karine; Bodere, Françoise; Bouchot, Olivier; Rigaud, Jérôme

2013-08-01

The objective of our study was to analyze the diagnostic performance of (18) F-fluorodeoxyglucose positron emission tomography-computed tomography for lymph node staging in patients with bladder cancer before radical cystectomy and to compare it with that of computed tomography. A total of 52 patients operated on between 2005 and 2010 were prospectively included in this prospective, mono-institutional, open, non-randomized pilot study. Patients who had received neoadjuvant chemotherapy or radiotherapy were excluded. (18) F-fluorodeoxyglucose positron emission tomography-computed tomography in addition to computed tomography was carried out for lymph node staging of bladder cancer before radical cystectomy. Lymph node dissection during radical cystectomy was carried out. Findings from (18) F-fluorodeoxyglucose positron emission tomography-computed tomography and computed tomography were compared with the results of definitive histological examination of the lymph node dissection. The diagnostic performance of the two imaging modalities was assessed and compared. The mean number of lymph nodes removed during lymph node dissection was 16.5 ± 10.9. Lymph node metastasis was confirmed on histological examination in 22 cases (42.3%). This had been suspected in five cases (9.6%) on computed tomography and in 12 cases (23.1%) on (18) F-fluorodeoxyglucose positron emission tomography-computed tomography. Sensitivity, specificity, positive predictive value, negative predictive value, relative risk and accuracy were 9.1%, 90%, 40%, 57.4%, 0.91 and 55.7%, respectively, for computed tomography, and 36.4%, 86.7%, 66.7%, 65%, 2.72, 65.4%, respectively, for (18) F-fluorodeoxyglucose positron emission tomography-computed tomography. (18) F-fluorodeoxyglucose positron emission tomography-computed tomography is more reliable than computed tomography for preoperative lymph node staging in patients with invasive bladder carcinoma undergoing radical cystectomy. © 2012 The Japanese

Intra-tumour 18F-FDG uptake heterogeneity decreases the reliability on target volume definition with positron emission tomography/computed tomography imaging

International Nuclear Information System (INIS)

Dong, Xinzhe; Wu, Peipei; Yu, Jinming; Xing, Ligang; Sun, Xiaorong; Li, Wenwu; Wan, Honglin

2015-01-01

This study aims to explore whether the intra-tumour 18 F-fluorodeoxyglucose (FDG) uptake heterogeneity affects the reliability of target volume definition with FDG positron emission tomography/computed tomography (PET/CT) imaging for nonsmall cell lung cancer (NSCLC) and squamous cell oesophageal cancer (SCEC). Patients with NSCLC (n = 50) or SCEC (n = 50) who received 18 F-FDG PET/CT scanning before treatments were included in this retrospective study. Intra-tumour FDG uptake heterogeneity was assessed by visual scoring, the coefficient of variation (COV) of the standardised uptake value (SUV) and the image texture feature (entropy). Tumour volumes (gross tumour volume (GTV) ) were delineated on the CT images (GTV CT ), the fused PET/CT images (GTV PET-CT ) and the PET images, using a threshold at 40% SUV max (GTV PET40% ) or the SUV cut-off value of 2.5 (GTV PET2.5 ). The correlation between the FDG uptake heterogeneity parameters and the differences in tumour volumes among GTV CT , GTV PET-CT , GTV PET40% and GTV PET2.5 was analysed. For both NSCLC and SCEC, obvious correlations were found between uptake heterogeneity, SUV or tumour volumes. Three types of heterogeneity parameters were consistent and closely related to each other. Substantial differences between the four methods of GTV definition were found. The differences between the GTV correlated significantly with PET heterogeneity defined with the visual score, the COV or the textural feature-entropy for NSCLC and SCEC. In tumours with a high FDG uptake heterogeneity, a larger GTV delineation difference was found. Advance image segmentation algorithms dealing with tracer uptake heterogeneity should be incorporated into the treatment planning system.

Methods and instrumentation for positron emission tomography

International Nuclear Information System (INIS)

Mandelkern, M.A.; Phelps, M.E.

1988-01-01

This paper reports on positron emission tomography (PET), a technique for the noninvasive measurement of local tissue concentrations of injected radioactive tracers. Tracer kinetics techniques can be applied to this information to quantify physiologic function in human tissue. In the tracer method, a pharmaceutical is labeled by a radioactive atom. When introduced into the subject that molecule follows a physiologic pathway. The space- and time-dependent distribution of the radionuclide is obtained via an imaging technique. If the radiopharmaceutical is sufficiently analogous to a natural substrate or other substance of interest, a quantitative image can be translated into a physiologic measurement

Scintillation crystals for positron emission tomography having a non reflecting band

International Nuclear Information System (INIS)

Thompson, C.J.

1992-01-01

This invention relates generally to positron emission tomography, a sub-field of the class of medical imaging techniques using ionizing radiation and image reconstruction techniques; and more particularly to devices which use an array of scintillation detectors to detect the annihilation radiation from positron disintegration and use this information to reconstruct an image of the distribution of positron emitting isotope within a body section. 6 figs

Dynamic emission tomography of regional cerebral blood flow

International Nuclear Information System (INIS)

Lassen, N.A.

1984-01-01

The author reviews three tomographic methods for measuring the regional cerebral blood flow: single photon transmission tomography; dual photon emission tomography; and single photon emission tomography. The latter technique is discussed in detail. (Auth.)

Dynamic positron emission tomography image restoration via a kinetics-induced bilateral filter.

Directory of Open Access Journals (Sweden)

Zhaoying Bian

Full Text Available Dynamic positron emission tomography (PET imaging is a powerful tool that provides useful quantitative information on physiological and biochemical processes. However, low signal-to-noise ratio in short dynamic frames makes accurate kinetic parameter estimation from noisy voxel-wise time activity curves (TAC a challenging task. To address this problem, several spatial filters have been investigated to reduce the noise of each frame with noticeable gains. These filters include the Gaussian filter, bilateral filter, and wavelet-based filter. These filters usually consider only the local properties of each frame without exploring potential kinetic information from entire frames. Thus, in this work, to improve PET parametric imaging accuracy, we present a kinetics-induced bilateral filter (KIBF to reduce the noise of dynamic image frames by incorporating the similarity between the voxel-wise TACs using the framework of bilateral filter. The aim of the proposed KIBF algorithm is to reduce the noise in homogeneous areas while preserving the distinct kinetics of regions of interest. Experimental results on digital brain phantom and in vivo rat study with typical (18F-FDG kinetics have shown that the present KIBF algorithm can achieve notable gains over other existing algorithms in terms of quantitative accuracy measures and visual inspection.

Positron emission tomography

International Nuclear Information System (INIS)

Iio, Masahiro

1982-01-01

Utilization of positron emission tomography was reviewed in relation to construction and planned construction of small-size medical cyclotrons, planned construction of positron cameras and utilization of short-lived radionuclides. (Chiba, N.)

Positron emission tomography-computed tomography standardized uptake values in clinical practice and assessing response to therapy.

Science.gov (United States)

Kinahan, Paul E; Fletcher, James W

2010-12-01

The use of standardized uptake values (SUVs) is now common place in clinical 2-deoxy-2-[(18)F] fluoro-D-glucose (FDG) position emission tomography-computed tomography oncology imaging and has a specific role in assessing patient response to cancer therapy. Ideally, the use of SUVs removes variability introduced by differences in patient size and the amount of injected FDG. However, in practice there are several sources of bias and variance that are introduced in the measurement of FDG uptake in tumors and also in the conversion of the image count data to SUVs. In this article the overall imaging process is reviewed and estimates of the magnitude of errors, where known, are given. Recommendations are provided for best practices in improving SUV accuracy. Copyright © 2010 Elsevier Inc. All rights reserved.

Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

1979-01-01

Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined.

Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

International Nuclear Information System (INIS)

Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

1979-01-01

Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined

Positron Emission Tomography (PET) and breast cancer in clinical practice

International Nuclear Information System (INIS)

Lavayssiere, Robert; Cabee, Anne-Elizabeth; Filmont, Jean-Emmanuel

2009-01-01

The landscape of oncologic practice has changed deeply during the past few years and there is now a need, through a multidisciplinary approach, for imaging to provide accurate evaluation of morphology and function and to guide treatment (Image Guided Therapy). Increasing emphasis has been put on Position Emission Tomography (PET) role in various cancers among clinicians and patients despite a general context of healthcare expenditure limitation. Positron Emission Tomography has currently a limited role in breast cancer, but also general radiologists and specialists should be aware of these indications, especially when staging aggressive cancers and looking for recurrence. Currently, the hybrid systems associating PET and Computed Tomography (CT) and in the same device [Rohren EM, Turkington TG, Coleman RE. Clinical applications of PET in oncology. Radiology 2004;231:305-32; Blodgett TM, Meltzer CM, Townsend DW. PET/CT: form and function. Radiology 2007;242:360-85; von Schulthess GK, Steinert HC, Hany TF. Integrated PET/CT: current applications and futures directions. Radiology 2006;238(2):405-22], or PET-CT, are more commonly used and the two techniques are adding their potentialities. Other techniques, MRI in particular, may also compete with PET in some instance and as far as ionizing radiations dose limitation is considered, some breast cancers becoming some form of a chronic disease. Breast cancer is a very complex, non-uniform, disease and molecular imaging at large may contribute to a better knowledge and to new drugs development. Ongoing research, Positron Emission Mammography (PEM) and new tracers, are likely to bring improvements in patient care [Kelloff GJ, Hoffman JM, Johnson B, et al. Progress and promise of FDG-PET Imaging for cancer patient management and oncologic drug development. Clin Cancer Res 2005;1(April (8)): 2005

Positron Emission Tomography (PET) and breast cancer in clinical practice

Energy Technology Data Exchange (ETDEWEB)

Lavayssiere, Robert [Centre d' Imagerie Paris-Nord, 1, avenue Charles Peguy, 95200 Sarcelles (France); Institut du Sein Henri Hartmann (ISHH), 1, rue des Dames Augustines, 92200 Neuilly sur Seine (France)], E-mail: cab.lav@wanadoo.fr; Cabee, Anne-Elizabeth [Centre d' Imagerie Paris-Nord, 1, avenue Charles Peguy, 95200 Sarcelles (France); Institut du Sein Henri Hartmann (ISHH), 1, rue des Dames Augustines, 92200 Neuilly sur Seine (France); Centre RMX, 80, avenue Felix Faure, 75105 Paris (France); Filmont, Jean-Emmanuel [Institut du Sein Henri Hartmann (ISHH), 1, rue des Dames Augustines, 92200 Neuilly sur Seine (France); American Hospital of Paris, Nuclear Medicine, 63, boulevard Victor Hugo - BP 109, 92202 Neuilly sur Seine Cedex (France)

2009-01-15

The landscape of oncologic practice has changed deeply during the past few years and there is now a need, through a multidisciplinary approach, for imaging to provide accurate evaluation of morphology and function and to guide treatment (Image Guided Therapy). Increasing emphasis has been put on Position Emission Tomography (PET) role in various cancers among clinicians and patients despite a general context of healthcare expenditure limitation. Positron Emission Tomography has currently a limited role in breast cancer, but also general radiologists and specialists should be aware of these indications, especially when staging aggressive cancers and looking for recurrence. Currently, the hybrid systems associating PET and Computed Tomography (CT) and in the same device [Rohren EM, Turkington TG, Coleman RE. Clinical applications of PET in oncology. Radiology 2004;231:305-32; Blodgett TM, Meltzer CM, Townsend DW. PET/CT: form and function. Radiology 2007;242:360-85; von Schulthess GK, Steinert HC, Hany TF. Integrated PET/CT: current applications and futures directions. Radiology 2006;238(2):405-22], or PET-CT, are more commonly used and the two techniques are adding their potentialities. Other techniques, MRI in particular, may also compete with PET in some instance and as far as ionizing radiations dose limitation is considered, some breast cancers becoming some form of a chronic disease. Breast cancer is a very complex, non-uniform, disease and molecular imaging at large may contribute to a better knowledge and to new drugs development. Ongoing research, Positron Emission Mammography (PEM) and new tracers, are likely to bring improvements in patient care [Kelloff GJ, Hoffman JM, Johnson B, et al. Progress and promise of FDG-PET Imaging for cancer patient management and oncologic drug development. Clin Cancer Res 2005;1(April (8)): 2005].

Cardiac and pericardial tumors: A potential application of positron emission tomography-magnetic resonance imaging.

Science.gov (United States)

Fathala, Ahmed; Abouzied, Mohei; AlSugair, Abdul-Aziz

2017-07-26

Cardiac and pericardial masses may be neoplastic, benign and malignant, non-neoplastic such as thrombus or simple pericardial cysts, or normal variants cardiac structure can also be a diagnostic challenge. Currently, there are several imaging modalities for diagnosis of cardiac masses; each technique has its inherent advantages and disadvantages. Echocardiography, is typically the initial test utilizes in such cases, Echocardiography is considered the test of choice for evaluation and detection of cardiac mass, it is widely available, portable, with no ionizing radiation and provides comprehensive evaluation of cardiac function and valves, however, echocardiography is not very helpful in many cases such as evaluation of extracardiac extension of mass, poor tissue characterization, and it is non diagnostic in some cases. Cross sectional imaging with cardiac computed tomography provides a three dimensional data set with excellent spatial resolution but utilizes ionizing radiation, intravenous iodinated contrast and relatively limited functional evaluation of the heart. Cardiac magnetic resonance imaging (CMR) has excellent contrast resolution that allows superior soft tissue characterization. CMR offers comprehensive evaluation of morphology, function, tissue characterization. The great benefits of CMR make CMR a highly useful tool in the assessment of cardiac masses. (Fluorine 18) fluorodeoxygluocse (FDG) positron emission tomography (PET) has become a corner stone in several oncological application such as tumor staging, restaging, treatment efficiency, FDG is a very useful imaging modality in evaluation of cardiac masses. A recent advance in the imaging technology has been the development of integrated PET-MRI system that utilizes the advantages of PET and MRI in a single examination. FDG PET-MRI provides complementary information on evaluation of cardiac masses. The purpose of this review is to provide several clinical scenarios on the incremental value of PET

Single photon emission computed tomography/spiral computed tomography fusion imaging for the diagnosis of bone metastasis in patients with known cancer

International Nuclear Information System (INIS)

Zhao, Zhen; Li, Lin; Li, Fanglan; Zhao, Lixia

2010-01-01

To evaluate single photon emission computed tomography (SPECT)/spiral computed tomography (CT) fusion imaging for the diagnosis of bone metastasis in patients with known cancer and to compare the diagnostic efficacy of SPECT/CT fusion imaging with that of SPECT alone and with SPECT + CT. One hundred forty-one bone lesions of 125 cancer patients (with nonspecific bone findings on bone scintigraphy) were investigated in the study. SPECT, CT, and SPECT/CT fusion images were acquired simultaneously. All images were interpreted independently by two experienced nuclear medicine physicians. In cases of discrepancy, consensus was obtained by a joint reading. The final diagnosis was based on biopsy proof and radiologic follow-up over at least 1 year. The final diagnosis revealed 63 malignant bone lesions and 78 benign lesions. The diagnostic sensitivity of SPECT, SPECT + CT, and SPECT/CT fusion imaging for malignant lesions was 82.5%, 93.7%, and 98.4%, respectively. Specificity was 66.7%, 80.8%, and 93.6%, respectively. Accuracy was 73.8%, 86.5%, and 95.7%, respectively. The specificity and accuracy of SPECT/CT fusion imaging for the diagnosis malignant bone lesions were significantly higher than those of SPECT alone and of SPECT + CT (P 2 = 9.855, P = 0.002). The numbers of equivocal lesions were 37, 18, and 5 for SPECT, SPECT + CT, and SPECT/CT fusion imaging, respectively, and 29.7% (11/37), 27.8% (5/18), and 20.0% (1/5) of lesions were confirmed to be malignant by radiologic follow-up over at least 1 year. SPECT/spiral CT is particularly valuable for the diagnosis of bone metastasis in patients with known cancer by providing precise anatomic localization and detailed morphologic characteristics. (orig.)

Preclinical and clinical evaluation of O-[11C]methyl-L-tyrosine for tumor imaging by positron emission tomography

International Nuclear Information System (INIS)

Ishiwata, Kiichi; Tsukada, Hideo; Kubota, Kazuo; Nariai, Tadashi; Harada, Norihiro; Kawamura, Kazunori; Kimura, Yuichi; Oda, Keiichi; Iwata, Ren; Ishii, Kenji

2005-01-01

We performed preclinical and clinical studies of O-[ 11 C]methyl-L-tyrosine, a potential tracer for imaging amino acid transport of tumors by positron emission tomography (PET). Examinations of the radiation-absorbed dose by O-[ 11 C]methyl-L-tyrosine and the acute toxicity and mutagenicity of O-methyl-L-tyrosine showed suitability of the tracer for clinical use. The whole-body imaging of monkeys and healthy humans by PET showed low uptake of O-[ 11 C]methyl-L-tyrosine in all normal organs except for the urinary track and bladder, suggesting that the O-[ 11 C]methyl-L-tyrosine PET has the potential for tumor imaging in the whole-body. Finally, the brain tumor imaging was preliminarily demonstrated

Detection of distant metastases in patients with locally advanced breast cancer: role of {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography and conventional imaging with computed tomography scans

Energy Technology Data Exchange (ETDEWEB)

Bitencourt, Almir Galvao Vieira; Andrade, Wesley Pereira; Cunha, Rodrigo Rodrigues da; Conrado, Jorge Luis Fonseca de Acioli; Lima, Eduardo Nobrega Pereira; Barbosa, Paula Nicole Vieira Pinto; Chojniak, Rubens, E-mail: rodrigo.rcunha@hotmail.com [A. C. Camargo Cancer Center, Sao Paulo, SP (Brazil); Hospital Beneficincia Portuguesa de Sao Paulo, Sao Paulo, SP (Brazil)

2017-07-15

Objective: To evaluate positron emission tomography/computed tomography (PET/CT) and conventional imaging tests for the detection of distant metastases in patients with locally advanced breast cancer. Materials and Methods: We included 81 patients with breast cancer who had undergone {sup 18}-fluorodeoxyglucose (FDG) PET/CT before treatment. Conventional imaging included the following: bone scintigraphy; chest X-ray (in 14.5%) or CT (in 85.5%); and abdominal ultrasound (in 10.8%), CT (in 87.8%), or magnetic resonance imaging (in 1.4%). Histopathology and clinical/imaging follow-up served as reference. Results: Distant metastases were observed in nine patients (11.1%). On patient-based analysis, conventional imaging identified distant metastases in all 9 patients. In one patient, the initial {sup 18}F-FDG PET/CT failed to demonstrate bone metastases that was evident on bone scintigraphy. In two patients, the CT scan failed to show extra-axillary lymph node metastases that were identified on {sup 18}F-FDG PET/CT. There was no significant difference between {sup 18}F-FDG PET/CT and conventional imaging in terms of their sensitivity for the detection of distant metastases in patients with locally advanced breast cancer. Conclusion: This study showed that {sup 18}F-FDG PET/CT and conventional imaging with CT scans had similar sensitivity for the diagnosis of distant metastases in patients with locally advanced breast cancer. {sup 18}F-FDG PET/CT can add information about extra-axillary lymph node involvements. (author)

Role of single photon emission computed tomography/computed tomography in diagnostic iodine-131 scintigraphy before initial radioiodine ablation in differentiated thyroid cancer

International Nuclear Information System (INIS)

Agrawal, Kanhaiyalal; Bhattacharya, Anish; Mittal, Bhagwant Rai

2005-01-01

The study was performed to evaluate the incremental value of single photon emission computed tomography/computed tomography (SPECT/CT) over planar radioiodine imaging before radioiodine ablation in the staging, management and stratification of risk of recurrence (ROR) in differentiated thyroid cancer (DTC) patients. Totally, 83 patients (21 male, 62 female) aged 17–75 (mean 39.9) years with DTC were included consecutively in this prospective study. They underwent postthyroidectomy planar and SPECT/CT scans after oral administration of 37–114 MBq iodine-131 (I-131). The scans were interpreted as positive, negative or suspicious for tracer uptake in the thyroid bed, cervical lymph nodes and sites outside the neck. In each case, the findings on planar images were recorded first, without knowledge of SPECT/CT findings. Operative and pathological findings were used for postsurgical tumor–node–metastasis staging. The tumor staging was reassessed after each of these two scans. Single photon emission computed tomography/computed tomography localized radioiodine uptake in the thyroid bed in 9/83 (10.8%) patients, neck nodes in 24/83 (28.9%) patients and distant metastases in 8/83 (9.6%) patients in addition to the planar study. Staging was changed in 8/83 (9.6%), ROR in 11/83 (13.2%) and management in 26/83 (31.3%) patients by the pretherapy SPECT/CT in comparison to planar imaging. SPECT/CT had incremental value in 32/83 patients (38.5%) over the planar scan. Single photon emission computed tomography/computed tomography is feasible during a diagnostic I-131 scan with a low amount of radiotracer. It improved the interpretation of pretherapy I-131 scintigraphy and changed the staging and subsequent patient management

Simultaneous 68Ga DOTATATE Positron Emission Tomography/Magnetic Resonance Imaging in Meningioma Target Contouring: Feasibility and Impact Upon Interobserver Variability Versus Positron Emission Tomography/Computed Tomography and Computed Tomography/Magnetic Resonance Imaging.

Science.gov (United States)

Maclean, J; Fersht, N; Sullivan, K; Kayani, I; Bomanji, J; Dickson, J; O'Meara, C; Short, S

2017-07-01

The increasing use of highly conformal radiation techniques to treat meningioma confers a greater need for accurate targeting. Several groups have shown that positron emission tomography/computed tomography (PET/CT) information alters meningioma targets contoured by single observers, but whether this translates into improved accuracy has not been defined. As magnetic resonance imaging (MRI) is the cornerstone of meningioma target contouring, simultaneous PET/MRI may be superior to PET/CT. We assessed whether 68 Ga DOTATATE PET imaging (from PET/CT and PET/MRI) reduced interobserver variability (IOV) in meningioma target volume contouring. Ten patients with meningioma underwent simultaneous 68 Ga DOTATATE PET/MRI followed by PET/CT. They were selected as it was anticipated that target volume definition in their cases would be particularly challenging. Three radiation oncologists contoured target volumes according to an agreed protocol: gross tumour volume (GTV) and clinical target volume (CTV) on CT/MRI alone, CT/MRI+PET(CT) and CT/MRI+PET(MRI). GTV/CTV Kouwenhoven conformity levels (KCL), regions of contour variation and qualitative differences between PET(CT) and PET(MRI) were evaluated. There was substantial IOV in contouring. GTV mean KCL: CT/MRI 0.34, CT/MRI+PET(CT) 0.38, CT/MRI+PET(MRI) 0.39 (P = 0.06). CTV mean KCL: CT/MRI 0.31, CT/MRI+PET(CT) 0.35, CT/MRI+PET(MRI) 0.35 (P = 0.04 for all groups; P > 0.05 for individual pairs). One observer consistently contoured largest and one smallest. Observers rarely decreased volumes in relation to PET. Most IOV occurred in bone followed by dural tail, postoperative bed and venous sinuses. Tumour edges were qualitatively clearer on PET(MRI) versus PET(CT), but this did not affect contouring. IOV in contouring challenging meningioma cases was large and only slightly improved with the addition of 68 Ga DOTATATE PET. Simultaneous PET/MRI for meningioma contouring is feasible, but did not improve IOV versus PET

18F-fluorodeoxyglucose positron emission tomography in colorectal cancer: value in primary staging and follow-up

International Nuclear Information System (INIS)

Joerg, L.; Heinisch, M.; Rechberger, E.; Kurz, F.; Klug, R.; Aufschnaiter, M; Hammer, J.; Langsteger, W.

2002-01-01

Positron emission tomography using 18 F-fluorodeoxyglucose (FDG-PET) is a encouraging imaging techniques allowing a highly sensitive whole-body search for malignant foci detected by their increased glucose metabolism compared with benign tissues. Several studies are now available that indicate its added value for diagnosis and staging of colorectal cancer. In all, patient management seems to be changed in 20-30 % of patients who undergo fluorodeoxyglucose positron emission tomography in addition to standard staging procedures. Fluorodeoxyglucose positron emission tomography is also useful in monitoring radiation therapy and chemotherapy. Regarding preoperative staging of primary colorectal cancer the literature is very limited. (author)

Positron emission tomography in the management of cervix cancer patients

International Nuclear Information System (INIS)

Bonardel, G.; Gontier, E.; Soret, M.; Dechaud, C.; Fayolle, M.; Foehrenbach, H.; Chargari, C.; Bauduceau, O.

2009-01-01

Since its introduction in clinical practice in the 1990 s, positron emission tomography (PET), usually with 18 F-fluoro-2-deoxy-D-glucose ( 18 F-F.D.G.), has become an important imaging modality in patients with cancer. For cervix carcinoma, F.D.G.-PET is significantly more accurate than computed tomography (CT) and is recommended for loco-regional lymph node and extra pelvic staging. The metabolic dimension of the technique provides additional prognostic information. Ongoing studies now concentrate on more advanced clinical applications, such as the planning of radiotherapy, the response evaluation after the induction of therapy, the early detection of recurrence. Technical innovations, such as PET cameras with better spatial resolution and hybrid positron emission tomography/computed tomography (PET-CT), available now on the whole territory, provide both anatomic and metabolic information in the same procedure. From the point of view of biological metabolism, new radiopharmaceutical probes are being developed. Those hold promise for future refinements in this field. This article reviews the current applications of F.D.G.-PET in patients with cervix cancer. (authors)

Emission computed tomography using rotating gamma cameras for stress 201Tl myocardial imaging

International Nuclear Information System (INIS)

Takeda, Kan; Maeda, Hisato; Nakagawa, Tsuyoshi; Yamaguchi, Nobuo; Taguchi, Mitsuo

1983-01-01

The purpose of this study is to evaluate the efficacy of emission computed tomography (ECT) for stress 201 Tl myocardial imaging to localize coronary artery disease (CAD) in comparison with planar (PL) images. In a series of 14 normal subjects and 53 patients with CAD proved coronary arteriography, ECT and PL imaging were performed successively. ECT data were collected for 90 projections in a 64 x 64 matrix form with a total aquisition time of 6 munutes over 180 0 of opposed dual cameras ratation and tomographic sections oriented perpendicular and parallel to the long axis of left ventricle were reconstructed. PL images were obtained for left lateral, left anterior oblique (30 0 and 45 0 ) and anterior projections. Both ECT and PL myocardial images were divided into 8 segments and segmental analysis was performed by visual interpretation. The ECT images remarkably increased sensitivity over the PL images in left anterior descending (LAD) artery (from 56% to 76%), right coronary artery (RCA) (from 50% to 96%), and circumflex artery (CX) (from 56% to 69%) lesions. The specificity for ECT images, as compared with PL images, was higher in LAD (88% against 85%) but slightly lower in RCA (70% ag ainst 72%) and CX (84% against 88%). Overall accuracy, therefore, was improved in LAD (from 67% to 81%) and RCA (from 64% to 79%) but equal in CX (81%). We conclude that stress 201 Tl ECT imaging result in a remarkable improvement in the localization of CAD, especially in patients with RCA lesions and multi-vessel disease. (author)

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

International Nuclear Information System (INIS)

Knešaurek, Karin

2015-01-01

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

Image-reconstruction algorithms for positron-emission tomography systems

International Nuclear Information System (INIS)

Cheng, S.N.C.

1982-01-01

The positional uncertainty in the time-of-flight measurement of a positron-emission tomography system is modelled as a Gaussian distributed random variable and the image is assumed to be piecewise constant on a rectilinear lattice. A reconstruction algorithm using maximum-likelihood estimation is derived for the situation in which time-of-flight data are sorted as the most-likely-position array. The algorithm is formulated as a linear system described by a nonseparable, block-banded, Toeplitz matrix, and a sine-transform technique is used to implement this algorithm efficiently. The reconstruction algorithms for both the most-likely-position array and the confidence-weighted array are described by similar equations, hence similar linear systems can be used to described the reconstruction algorithm for a discrete, confidence-weighted array, when the matrix and the entries in the data array are properly identified. It is found that the mean square-error depends on the ratio of the full width at half the maximum of time-of-flight measurement over the size of a pixel. When other parameters are fixed, the larger the pixel size, the smaller is the mean square-error. In the study of resolution, parameters that affect the impulse response of time-of-flight reconstruction algorithms are identified. It is found that the larger the pixel size, the larger is the standard deviation of the impulse response. This shows that small mean square-error and fine resolution are two contradictory requirements

Preoperative lymph-node staging of invasive urothelial bladder cancer with 18F-fluorodeoxyglucose positron emission tomography/computed axial tomography and magnetic resonance imaging

DEFF Research Database (Denmark)

Jensen, Thor Knak; Holt, Per; Gerke, Oke

2011-01-01

OBJECTIVE: The treatment and prognosis of bladder cancer are based on the depth of primary tumour invasion and the presence of metastases. A highly accurate preoperative tumour, node, metastasis (TNM) staging is critical to proper patient management and treatment. This study retrospectively...... investigated the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed axial tomography (¹⁸F-FDG PET/CT) and magnetic resonance imaging (MRI) for preoperative N staging of bladder cancer. Material and methods. From June 2006 to January 2008, 48 consecutive patients diagnosed with bladder......) for MRI and ¹⁸F-FDG PET/CT, respectively. The differences in specificity and negative predictive values were not statistically significant. Conclusions. No significant statistical difference between ¹⁸F-FDG PET/CT and MRI for preoperative N staging of urothelial bladder cancer was found in the study...

Patient Study of In Vivo Verification of Beam Delivery and Range, Using Positron Emission Tomography and Computed Tomography Imaging After Proton Therapy

International Nuclear Information System (INIS)

Parodi, Katia; Paganetti, Harald; Shih, Helen A.; Michaud, Susan; Loeffler, Jay S.; DeLaney, Thomas F.; Liebsch, Norbert J.; Munzenrider, John E.; Fischman, Alan J.; Knopf, Antje; Bortfeld, Thomas

2007-01-01

Purpose: To investigate the feasibility and value of positron emission tomography and computed tomography (PET/CT) for treatment verification after proton radiotherapy. Methods and Materials: This study included 9 patients with tumors in the cranial base, spine, orbit, and eye. Total doses of 1.8-3 GyE and 10 GyE (for an ocular melanoma) per fraction were delivered in 1 or 2 fields. Imaging was performed with a commercial PET/CT scanner for 30 min, starting within 20 min after treatment. The same treatment immobilization device was used during imaging for all but 2 patients. Measured PET/CT images were coregistered to the planning CT and compared with the corresponding PET expectation, obtained from CT-based Monte Carlo calculations complemented by functional information. For the ocular case, treatment position was approximately replicated, and spatial correlation was deduced from reference clips visible in both the planning radiographs and imaging CT. Here, the expected PET image was obtained from an analytical model. Results: Good spatial correlation and quantitative agreement within 30% were found between the measured and expected activity. For head-and-neck patients, the beam range could be verified with an accuracy of 1-2 mm in well-coregistered bony structures. Low spine and eye sites indicated the need for better fixation and coregistration methods. An analysis of activity decay revealed as tissue-effective half-lives of 800-1,150 s. Conclusions: This study demonstrates the feasibility of postradiation PET/CT for in vivo treatment verification. It also indicates some technological and methodological improvements needed for optimal clinical application

Intra-tumour 18F-FDG uptake heterogeneity decreases the reliability on target volume definition with positron emission tomography/computed tomography imaging.

Science.gov (United States)

Dong, Xinzhe; Wu, Peipei; Sun, Xiaorong; Li, Wenwu; Wan, Honglin; Yu, Jinming; Xing, Ligang

2015-06-01

This study aims to explore whether the intra-tumour (18) F-fluorodeoxyglucose (FDG) uptake heterogeneity affects the reliability of target volume definition with FDG positron emission tomography/computed tomography (PET/CT) imaging for nonsmall cell lung cancer (NSCLC) and squamous cell oesophageal cancer (SCEC). Patients with NSCLC (n = 50) or SCEC (n = 50) who received (18)F-FDG PET/CT scanning before treatments were included in this retrospective study. Intra-tumour FDG uptake heterogeneity was assessed by visual scoring, the coefficient of variation (COV) of the standardised uptake value (SUV) and the image texture feature (entropy). Tumour volumes (gross tumour volume (GTV)) were delineated on the CT images (GTV(CT)), the fused PET/CT images (GTV(PET-CT)) and the PET images, using a threshold at 40% SUV(max) (GTV(PET40%)) or the SUV cut-off value of 2.5 (GTV(PET2.5)). The correlation between the FDG uptake heterogeneity parameters and the differences in tumour volumes among GTV(CT), GTV(PET-CT), GTV(PET40%) and GTV(PET2.5) was analysed. For both NSCLC and SCEC, obvious correlations were found between uptake heterogeneity, SUV or tumour volumes. Three types of heterogeneity parameters were consistent and closely related to each other. Substantial differences between the four methods of GTV definition were found. The differences between the GTV correlated significantly with PET heterogeneity defined with the visual score, the COV or the textural feature-entropy for NSCLC and SCEC. In tumours with a high FDG uptake heterogeneity, a larger GTV delineation difference was found. Advance image segmentation algorithms dealing with tracer uptake heterogeneity should be incorporated into the treatment planning system. © 2015 The Royal Australian and New Zealand College of Radiologists.

Sacrococcygeal chordoma: increased 99mTc methylene diphosphonate uptake on single photon emission computed tomography/computed tomography bone scintigraphy

International Nuclear Information System (INIS)

Kamaleshwaran, Koramadai Karuppuswamy; Bhattacharya, Anish; Harisankar, Chidambaram Natarajan Balasubramaniam; Mittal, Bhagwant Rai; Goni, Vijay

2012-01-01

Chordoma is a malignant tumor arising from the remnants of the notochord, and is the most frequent primitive tumor of the sacrum. While most sacral tumors show increased concentration of bone-seeking radiopharmaceuticals, chordomas usually exhibit decreased uptake. The authors present an image of a sacrococcygeal chordoma with osteolysis and increased uptake of 99m Tc methylene diphosphonate on planar and single photon emission computed tomography/computed tomography bone scintigraphy. (author)

Computed tomography angiography and perfusion to assess coronary artery stenosis causing perfusion defects by single photon emission computed tomography

DEFF Research Database (Denmark)

Rochitte, Carlos E; George, Richard T; Chen, Marcus Y

2014-01-01

AIMS: To evaluate the diagnostic power of integrating the results of computed tomography angiography (CTA) and CT myocardial perfusion (CTP) to identify coronary artery disease (CAD) defined as a flow limiting coronary artery stenosis causing a perfusion defect by single photon emission computed...... emission computed tomography (SPECT/MPI). Sixteen centres enroled 381 patients who underwent combined CTA-CTP and SPECT/MPI prior to conventional coronary angiography. All four image modalities were analysed in blinded independent core laboratories. The prevalence of obstructive CAD defined by combined ICA...... tomography (SPECT). METHODS AND RESULTS: We conducted a multicentre study to evaluate the accuracy of integrated CTA-CTP for the identification of patients with flow-limiting CAD defined by ≥50% stenosis by invasive coronary angiography (ICA) with a corresponding perfusion deficit on stress single photon...

Novel targets for positron emission tomography (PET) radiopharmaceutical tracers for visualization of neuroinflammation

Science.gov (United States)

Shchepetkin, I.; Shvedova, M.; Anfinogenova, Y.; Litvak, M.; Atochin, D.

2017-08-01

Non-invasive molecular imaging techniques can enhance diagnosis of neurological diseases to achieve their successful treatment. Positron emission tomography (PET) imaging can identify activated microglia and provide detailed functional information based on molecular biology. This imaging modality is based on detection of isotope labeled tracers, which emit positrons. The review summarizes the developments of various radiolabeled ligands for PET imaging of neuroinflammation.

Anti-3-[(18)F]FACBC positron emission tomography-computerized tomography and (111)In-capromab pendetide single photon emission computerized tomography-computerized tomography for recurrent prostate carcinoma: results of a prospective clinical trial.

Science.gov (United States)

Schuster, David M; Nieh, Peter T; Jani, Ashesh B; Amzat, Rianot; Bowman, F Dubois; Halkar, Raghuveer K; Master, Viraj A; Nye, Jonathon A; Odewole, Oluwaseun A; Osunkoya, Adeboye O; Savir-Baruch, Bital; Alaei-Taleghani, Pooneh; Goodman, Mark M

2014-05-01

We prospectively evaluated the amino acid analogue positron emission tomography radiotracer anti-3-[(18)F]FACBC compared to ProstaScint® ((111)In-capromab pendetide) single photon emission computerized tomography-computerized tomography to detect recurrent prostate carcinoma. A total of 93 patients met study inclusion criteria who underwent anti-3-[(18)F]FACBC positron emission tomography-computerized tomography plus (111)In-capromab pendetide single photon emission computerized tomography-computerized tomography for suspected recurrent prostate carcinoma within 90 days. Reference standards were applied by a multidisciplinary board. We calculated diagnostic performance for detecting disease. In the 91 of 93 patients with sufficient data for a consensus on the presence or absence of prostate/bed disease anti-3-[(18)F]FACBC had 90.2% sensitivity, 40.0% specificity, 73.6% accuracy, 75.3% positive predictive value and 66.7% negative predictive value compared to (111)In-capromab pendetide with 67.2%, 56.7%, 63.7%, 75.9% and 45.9%, respectively. In the 70 of 93 patients with a consensus on the presence or absence of extraprostatic disease anti-3-[(18)F]FACBC had 55.0% sensitivity, 96.7% specificity, 72.9% accuracy, 95.7% positive predictive value and 61.7% negative predictive value compared to (111)In-capromab pendetide with 10.0%, 86.7%, 42.9%, 50.0% and 41.9%, respectively. Of 77 index lesions used to prove positivity histological proof was obtained in 74 (96.1%). Anti-3-[(18)F]FACBC identified 14 more positive prostate bed recurrences (55 vs 41) and 18 more patients with extraprostatic involvement (22 vs 4). Anti-3-[(18)F]FACBC positron emission tomography-computerized tomography correctly up-staged 18 of 70 cases (25.7%) in which there was a consensus on the presence or absence of extraprostatic involvement. Better diagnostic performance was noted for anti-3-[(18)F]FACBC positron emission tomography-computerized tomography than for (111)In-capromab pendetide single

Positron emission tomography (PET) for oncologic applications in oral region

International Nuclear Information System (INIS)

Shozushima, Masanori; Terasaki, Kazunori

2004-01-01

A rapidly emerging clinical application of positron emission tomography (PET) is the detection of cancer with radionuclide tracer, because it provides information unavailable by ultrasound, computed tomography or magnetic resonance imaging. The most commonly used radiotracer for PET oncologic imaging is fluorine-18-labeled fluorodeoxyglucose ( 18 F-FDG). Early studies show PET has potential value in viewing the region of the tumor, detecting, staging, grading, monitoring response to anticancer therapy, and differentiating recurrent or residual disease from post treatment changes. However, limitations of FDG-PET in the head and neck region, namely, physiological FDG uptake in the salivary glands and palatine tonsils, have been reported, increasing the false-positive rates in image interpretation. This review was designed to address these distinctions of oral cancer PET imaging: specialization of PET equipment, cancer cell metabolism, proliferation and tracers, clinical diagnosis of oral cancer with PET, pitfalls in oncologic diagnosis with FDG-PET imaging. (author)

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

Science.gov (United States)

Vercher-Conejero, J L; Gámez Cenzano, C

2016-01-01

The development of molecular and functional imaging with new imaging techniques such as computed tomography, magnetic resonance imaging, and positron emission tomography (PET) among others, has greatly improved the detection of tumors, tumor staging, and the detection of possible recurrences. Furthermore, the combination of these different imaging modalities and the continual development of radiotracers for PET have advanced our understanding and knowledge of the different pathophysiological processes in cancer, thereby helping to make treatment more efficacious, improving patients' quality of life, and increasing survival. PET is one of the imaging techniques that has attracted the most interest in recent years for its diagnostic capabilities. Its ability to anatomically locate pathologic foci of metabolic activity has revolutionized the detection and staging of many tumors, exponentially broadening its potential indications not only in oncology but also in other fields such as cardiology, neurology, and inflammatory and infectious diseases. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Functional imaging of the brain with positron emission tomography

International Nuclear Information System (INIS)

Alavi, A.; Reivich, M.; Jones, S.C.; Greenberg, J.H.; Wolf, A.P.

1982-01-01

An extensive review, with 191 references, of the development and diagnostic use of positron emission tomography (PET) of the brain is presented. An historical overview of functional studies of the brain reviews the use of nitrons oxide, 85 Kr and 133 Xe, [ 14 C]2-deoxyglucose, and [ 18 F]FDG. The [ 18 F]FDG technique allows the investigation of the effects of physiologic stimulation on the brain. Several studies using this technique are reported. The effects of stroke, seizure disorders, aging and dementia, and schizophrenia on cerebral metabolism as demosntrated by PET are explored

Single-photon emission computed tomography in the clinical evaluation of dementia

International Nuclear Information System (INIS)

Jagust, W.J.; Reed, B.R.; Budinger, T.F.; Colina, M.

1987-01-01

Physiological imaging using positron emission tomography (PET) has been a useful tool in the investigation of dementia. In particular, patterns of cerebral glucose utilization appear to differentiate various types of dementia, with Alzheimer's disease (AD) demonstrating a propensity for hypometabolism to involve the temporoparietal cortex. Single-photon emission computed tomography (SPECT) using new tracers for the measurement of regional cerebral blood flow is a technique with potentially broader clinical availability than PET and thus may provide a practical method of routinely evaluating patients. The authors studied eight patients with AD, four healthy elderly controls, and one patient with multi-infarct dementia (MID) using the tracer 123 I-N-isopropyl-p-iodoamphetamine with SPECT

Contrast-enhanced 18F-fluorodeoxyglucose positron emission tomography/computed tomography in immunoglobulin G4-related retroperitoneal fibrosis

International Nuclear Information System (INIS)

Sharma, Punit; Chatterjee, Piyali

2015-01-01

Immunoglobulin G4 (IgG4)-related disease encompasses a wide variety of immune disorders previously thought be distinct. IgG4-related retroperitoneal fibrosis is one such entity. Metabolic imaging with 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) can be useful in the management of IgG4-related retroperitoneal fibrosis. We here discuss the case of 63-year-old male with IgG4-related retroperitoneal fibrosis and the role, 18 F-FDG PET/CT played in his management

Preclinical and clinical evaluation of O-[{sup 11}C]methyl-L-tyrosine for tumor imaging by positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Ishiwata, Kiichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan)]. E-mail: ishiwata@pet.tmig.or.jp; Tsukada, Hideo [Central Research Laboratory, Hamamatsu Photonics K.K., Hamakita 434-8601 (Japan); Kubota, Kazuo [Department of Radiology, Division of Nuclear Medicine, International Medical Center of Japan, Shinjuku-ku, Tokyo 162-8655 (Japan); Nariai, Tadashi [Department of Neurosurgery, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8519 (Japan); Harada, Norihiro [Department of Radiology, Division of Nuclear Medicine, International Medical Center of Japan, Shinjuku-ku, Tokyo 162-8655 (Japan); Kawamura, Kazunori [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan); SHI Accelerator Service Ltd., Shinagawa-ku, Tokyo 141-8686 (Japan); Kimura, Yuichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan); Oda, Keiichi [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan); Iwata, Ren [CYRIC, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo 173-0022 (Japan)

2005-04-01

We performed preclinical and clinical studies of O-[{sup 11}C]methyl-L-tyrosine, a potential tracer for imaging amino acid transport of tumors by positron emission tomography (PET). Examinations of the radiation-absorbed dose by O-[{sup 11}C]methyl-L-tyrosine and the acute toxicity and mutagenicity of O-methyl-L-tyrosine showed suitability of the tracer for clinical use. The whole-body imaging of monkeys and healthy humans by PET showed low uptake of O-[{sup 11}C]methyl-L-tyrosine in all normal organs except for the urinary track and bladder, suggesting that the O-[{sup 11}C]methyl-L-tyrosine PET has the potential for tumor imaging in the whole-body. Finally, the brain tumor imaging was preliminarily demonstrated.

Use of computed tomography and positron emission tomography/computed tomography for staging of local extent in patients with malignant pleural mesothelioma.

Science.gov (United States)

Frauenfelder, Thomas; Kestenholz, Peter; Hunziker, Roger; Nguyen, Thi Dan Linh; Fries, Martina; Veit-Haibach, Patrick; Husmann, Lars; Stahel, Rolf; Weder, Walter; Opitz, Isabelle

2015-01-01

The objective of this study was to determine the diagnostic value of computed tomography (CT) and positron emission tomography (PET)/CT for staging of malignant pleural mesothelioma (MPM) in patients undergoing induction chemotherapy. Sixty-two patients (median age, 61 years; female: n = 9) with proven MPM underwent CT after induction chemotherapy. Of these, 28 underwent additional PET/CT. Extrapleural pneumonectomy was performed for pathological TNM staging. Clinical TNM stage was assessed by 3 independent readers. Relative and absolute underestimation and overestimation were compared with pathological tumor stage. Sensitivity, specificity, and accuracy for differentiation between stages T2 and T3 were assessed. Interobserver agreement between the readers was analyzed (κ). Positron emission tomography/CT and CT underestimated T stage in up to 30% of the cases. Positron emission tomography/CT had a higher accuracy for tumor extent compared with CT (PET/CT: 0.92; CT: 0.84). The accuracy for nodal staging was higher for CT than for PET/CT (PET/CT: 0.78; CT: 0.87). Concerning International Mesothelioma Interest Group classification, PET/CT improved the accuracy of preoperative staging compared with CT (PET/CT: 0.91; CT: 0.82). Interobserver agreement was moderate for CT (0.48-0.62) and good for PET/CT (0.64-0.83) for T staging. For nodal staging, interobserver agreement was fair to moderate for CT and good for PET/CT (CT: 0.37-0.51; PET/CT: 0.73-0.76). Positron emission tomography/CT is more accurate and has a lower interobserver variability for clinical intrathoracic staging of MPM compared with CT. Nevertheless PET/CT underestimated tumor stage in a substantial number of cases, showing the need for a more accurate imaging technology or approach.

Preclinical evaluation of a positron emitting progestin ([18F]fluoro-16 alpha-methyl-19-norprogesterone) for imaging progesterone receptor positive tumours with positron emission tomography

NARCIS (Netherlands)

Verhagen, Aalt; Luurtsema, Gert; PESSER, JW; DEGROOT, TJ; OOSTERHUIS, JW; Vaalburg, Willem; Wouda, S.

Three 21-fluoro-progestins were investigated as potential imaging agents for the in vivo assessment of human progesterone receptor positive neoplasms with positron emission tomography. In competitive binding assays these compounds demonstrated high specificity, competing only for progesterone

Therapy response evaluation with positron emission tomography-computed tomography.

Science.gov (United States)

Segall, George M

2010-12-01

Positron emission tomography-computed tomography with F-18-fluorodeoxyglucose is widely used for evaluation of therapy response in patients with solid tumors but has not been as readily adopted in clinical trials because of the variability of acquisition and processing protocols and the absence of universal response criteria. Criteria proposed for clinical trials are difficult to apply in clinical practice, and gestalt impression is probably accurate in individual patients, especially with respect to the presence of progressive disease and complete response. Semiquantitative methods of determining tissue glucose metabolism, such as standard uptake value, can be a useful descriptor for levels of tissue glucose metabolism and changes in response to therapy if technical quality control measures are carefully maintained. The terms partial response, complete response, and progressive disease are best used in clinical trials in which the terms have specific meanings and precise definitions. In clinical practice, it may be better to use descriptive terminology agreed upon by imaging physicians and clinicians in their own practice. Copyright © 2010. Published by Elsevier Inc.

Fluorodeoxyglucose positron emission tomography/computed tomography findings in a patient with cerebellar mutism after operation in posterior fossa

Directory of Open Access Journals (Sweden)

Gonca Kara Gedik

2017-03-01

Full Text Available Cerebellar mutism is a transient period of speechlessness that evolves after posterior fossa surgery in children. Although direct cerebellar and brain stem injury and supratentorial dysfunction have been implicated in the mediation of mutism, the pathophysiological mechanisms involved in the evolution of this kind of mutism remain unclear. Magnetic resonance imaging revealed dentatothalamocortical tract injuries and single photon emission computed tomography showed cerebellar and cerebral hypoperfusion in patients with cerebellar mutism. However, findings with 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT in this group of patients have not been documented previously. In this clinical case, we report a patient who experienced cerebellar mutism after undergoing a posterior fossa surgery. Right cerebellar and left frontal lobe hypometabolism was shown using FDG PET/CT. The FDG metabolism of both the cerebellum and the frontal lobe returned to normal levels after the resolution of the mutism symptoms.

Motion correction in thoracic positron emission tomography

CERN Document Server

Gigengack, Fabian; Dawood, Mohammad; Schäfers, Klaus P

2015-01-01

Respiratory and cardiac motion leads to image degradation in Positron Emission Tomography (PET), which impairs quantification. In this book, the authors present approaches to motion estimation and motion correction in thoracic PET. The approaches for motion estimation are based on dual gating and mass-preserving image registration (VAMPIRE) and mass-preserving optical flow (MPOF). With mass-preservation, image intensity modulations caused by highly non-rigid cardiac motion are accounted for. Within the image registration framework different data terms, different variants of regularization and parametric and non-parametric motion models are examined. Within the optical flow framework, different data terms and further non-quadratic penalization are also discussed. The approaches for motion correction particularly focus on pipelines in dual gated PET. A quantitative evaluation of the proposed approaches is performed on software phantom data with accompanied ground-truth motion information. Further, clinical appl...

NMF on positron emission tomography

DEFF Research Database (Denmark)

Bödvarsson, Bjarni; Hansen, Lars Kai; Svarer, Claus

2007-01-01

In positron emission tomography, kinetic modelling of brain tracer uptake, metabolism or binding requires knowledge of the cerebral input function. Traditionally, this is achieved with arterial blood sampling in the arm or as shown in (Liptrot, M, et al., 2004) by non-invasive K-means clustering....... We propose another method to estimate time-activity curves (TAC) extracted directly from dynamic positron emission tomography (PET) scans by non-negative matrix factorization (NMF). Since the scaling of the basis curves is lost in the NMF the estimated TAC is scaled by a vector alpha which...

Positron emission tomography in oncology

International Nuclear Information System (INIS)

Anon.

1988-01-01

This report describes the current and potential uses of positron emission tomography in clinical medicine and research related to oncology. Assessment will be possible of metabolism and physiology of tumors and their effects on adjacent tissues. Specific probes are likely to be developed for target sites on tumors, including monoclonal antibodies and specific growth factors that recognize tumors. To date, most oncological applications of positron emission tomography tracers have been qualitative; in the future, quantitative metabolic measurements should aid in the evaluation of tumor biology and response to treatment

Semi-supervised manifold learning with affinity regularization for Alzheimer's disease identification using positron emission tomography imaging.

Science.gov (United States)

Lu, Shen; Xia, Yong; Cai, Tom Weidong; Feng, David Dagan

2015-01-01

Dementia, Alzheimer's disease (AD) in particular is a global problem and big threat to the aging population. An image based computer-aided dementia diagnosis method is needed to providing doctors help during medical image examination. Many machine learning based dementia classification methods using medical imaging have been proposed and most of them achieve accurate results. However, most of these methods make use of supervised learning requiring fully labeled image dataset, which usually is not practical in real clinical environment. Using large amount of unlabeled images can improve the dementia classification performance. In this study we propose a new semi-supervised dementia classification method based on random manifold learning with affinity regularization. Three groups of spatial features are extracted from positron emission tomography (PET) images to construct an unsupervised random forest which is then used to regularize the manifold learning objective function. The proposed method, stat-of-the-art Laplacian support vector machine (LapSVM) and supervised SVM are applied to classify AD and normal controls (NC). The experiment results show that learning with unlabeled images indeed improves the classification performance. And our method outperforms LapSVM on the same dataset.

[Myocardial single photon emission tomography imaging of reporter gene expression in rabbits].

Science.gov (United States)

Liu, Ying; Lan, Xiao-li; Zhang, Liang; Wu, Tao; Jiang, Ri-feng; Zhang, Yong-xue

2009-06-01

To explore the feasibility of single photon emission computed tomography (SPECT) detection of heart reporter gene expression and observed the optimal transfecting titer and imaging time by using herpes simplex virus 1-thymidine kinase (HSV1-tk) as reporter gene and 131I-2'-fluoro-2'-deoxy-1-beta-D-arabinofuranosyl-5-iodouracil (131I-FIAU) as reporter probe in rabbit myocardium. The recombinant Ad-tk carrying HSV1-tk gene and adenovirus (Ad) as vector was constructed and intramyocardially injected to rabbits at various concentrations (1 x 10(9) pfu, 5 x 10(8) pfu, 1 x 10(8) pfu, 5 x 10(7) pfu, 1 x 10(7) pfu). Two days later, rabbits were injected with 600 microCi 131I-FIAU in ear-margin vein and then underwent SPECT myocardium imaging for detection of HSV1-tk expression at 6 h, 24 h, 48 h and 72 h after injection, rabbits with 1 x 10(9) pfu Ad-tk injection were imaged at 96 h and 120 h. Rabbits were sacrificed after imaging and the total myocardial 131I-FIAU accumulation was quantified in percent of injected dose per gram myocardium (% ID/g). The myocardial Ad-tk expression was determined with RT-PCR. Reporter gene was detected by SPECT imaging in the injection site while not detected in the control myocardium and site remote from injection. RT-PCR results also evidenced HSV1-tk express in the injection site. The SPECT target/nontarget ratio was correlated with ex vivo gamma-counting (r2 = 0.933, Ppfu by SPECT imaging. The cardiac SPECT reporter gene imaging with HSV1-tk as reporter gene and 131I-FIAU as reporter probe is feasible.

Transmission imaging for registration of ictal and interictal single-photon emission tomography, magnetic resonance imaging and electroencephalography

Energy Technology Data Exchange (ETDEWEB)

Sipilae, O. [Epilepsy Unit, Neurology, Hospital for Children and Adolescents, Helsinki University Central Hospital (Finland); Laboratory of Biomedical Engineering, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT (Finland); Nikkinen, P.; Liewendahl, K. [Division of Nuclear Medicine, Laboratory Department, Helsinki University Central Hospital (Finland); Savolainen, S. [Division of Nuclear Medicine, Laboratory Department, Helsinki University Central Hospital (Finland); Department of Radiology, Helsinki University Central Hospital (Finland); Granstroem, M.-L.; Gaily, E. [Epilepsy Unit, Neurology, Hospital for Children and Adolescents, Helsinki University Central Hospital (Finland); Poutanen, V.-P. [Department of Radiology, Helsinki University Central Hospital (Finland); Pohjonen, H. [Technology Development Centre, P.O. Box 69, 00101 Helsinki (Finland)

2000-02-01

A method developed for registration of ictal and interictal single-photon emission tomography (SPET), magnetic resonance imaging (MRI) and electroencephalography (EEG) is described. For SPET studies, technetium-99m ethyl cysteinate dimer (ECD) was injected intravenously while the patient was monitored on video-EEG to document the ictal or interictal state. Imaging was performed using a triple-head gamma camera equipped with a transmission imaging device using a gadolinium-153 source. The images (128 x 128 pixels, voxel size 3.7 x 3.7 x 3.6 mm{sup 3}) were reconstructed using an iterative algorithm and postfiltered with a Wiener filter. The gold-plated silver electrodes on the patient's scalp were utilized as markers for registration of the ictal and interictal SPET images, as these metallic markers were clearly seen on the transmission images. Fitting of the marker sets was based on a non-iterative least squares method. The interictal SPET image was subtracted from the ictal image after scaling. The T1-weighted MPRAGE MR images with voxel size of 1.0 x 1.0 x 1.0 mm{sup 3} were obtained with a 1.5-T scanner. For registration of MR and subtraction SPET images, the external marker set of the ictal SPET study was fitted to the surface of the head segmented from MR images. The SPET registration was tested with a phantom experiment. Registration of ictal and interictal SPET in five patient studies resulted in a 2-mm RMS residual of the marker sets. The estimated RMS error of registration in the final result combining locations of the electrodes, subtraction SPET and MR images was 3-5 mm. In conclusion, transmission imaging can be utilized for an accurate and easily implemented registration procedure for ictal and interictal SPET, MRI and EEG. (orig.)

PET and Single-Photon Emission Computed Tomography in Brain Concussion.

Science.gov (United States)

Raji, Cyrus A; Henderson, Theodore A

2018-02-01

This article offers an overview of the application of PET and single photon emission computed tomography brain imaging to concussion, a type of mild traumatic brain injury and traumatic brain injury, in general. The article reviews the application of these neuronuclear imaging modalities in cross-sectional and longitudinal studies. Additionally, this article frames the current literature with an overview of the basic physics and radiation exposure risks of each modality. Copyright © 2017 Elsevier Inc. All rights reserved.

Positron emission tomography

NARCIS (Netherlands)

Paans, AMJ

Positron Emission Tomography (PET) is a method for determining biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labelled with positron emitting radionuclides as C-11, N-13, O-15 and F-18 and by measuring the annihilation radiation using a

Positron Emission Tomography/Computed Tomography Imaging of Residual Skull Base Chordoma Before Radiotherapy Using Fluoromisonidazole and Fluorodeoxyglucose: Potential Consequences for Dose Painting

Energy Technology Data Exchange (ETDEWEB)

Mammar, Hamid, E-mail: hamid.mammar@unice.fr [Radiation Oncology Department, Antoine Lacassagne Center, Nice (France); CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France); Kerrou, Khaldoun; Nataf, Valerie [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France); Pontvert, Dominique [Proton Therapy Center of Orsay, Curie Institute, Paris (France); Clemenceau, Stephane [Department of Neurosurgery, Pitie-Salpetriere Hospital, Paris (France); Lot, Guillaume [Department of Neurosurgery, Adolph De Rothschild Foundation, Paris (France); George, Bernard [Department of Neurosurgery, Lariboisiere Hospital, Paris (France); Polivka, Marc [Department of Pathology, Lariboisiere Hospital, Paris (France); Mokhtari, Karima [Department of Pathology, Pitie-Salpetriere Hospital, Paris (France); Ferrand, Regis; Feuvret, Loiec; Habrand, Jean-louis [Proton Therapy Center of Orsay, Curie Institute, Paris (France); Pouyssegur, Jacques; Mazure, Nathalie [CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France); Talbot, Jean-Noeel [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)

2012-11-01

Purpose: To detect the presence of hypoxic tissue, which is known to increase the radioresistant phenotype, by its uptake of fluoromisonidazole (18F) (FMISO) using hybrid positron emission tomography/computed tomography (PET/CT) imaging, and to compare it with the glucose-avid tumor tissue imaged with fluorodeoxyglucose (18F) (FDG), in residual postsurgical skull base chordoma scheduled for radiotherapy. Patients and Methods: Seven patients with incompletely resected skull base chordomas were planned for high-dose radiotherapy (dose {>=}70 Gy). All 7 patients underwent FDG and FMISO PET/CT. Images were analyzed qualitatively by visual examination and semiquantitatively by computing the ratio of the maximal standardized uptake value (SUVmax) of the tumor and cerebellum (T/C R), with delineation of lesions on conventional imaging. Results: Of the eight lesion sites imaged with FDG PET/CT, only one was visible, whereas seven of nine lesions were visible on FMISO PET/CT. The median SUVmax in the tumor area was 2.8 g/mL (minimum 2.1; maximum 3.5) for FDG and 0.83 g/mL (minimum 0.3; maximum 1.2) for FMISO. The T/C R values ranged between 0.30 and 0.63 for FDG (median, 0.41) and between 0.75 and 2.20 for FMISO (median,1.59). FMISO T/C R >1 in six lesions suggested the presence of hypoxic tissue. There was no correlation between FMISO and FDG uptake in individual chordomas (r = 0.18, p = 0.7). Conclusion: FMISO PET/CT enables imaging of the hypoxic component in residual chordomas. In the future, it could help to better define boosted volumes for irradiation and to overcome the radioresistance of these lesions. No relationship was founded between hypoxia and glucose metabolism in these tumors after initial surgery.

Pure ground glass nodular adenocarcinomas: Are preoperative positron emission tomography/computed tomography and brain magnetic resonance imaging useful or necessary?

Science.gov (United States)

Cho, Hyoun; Lee, Ho Yun; Kim, Jhingook; Kim, Hong Kwan; Choi, Joon Young; Um, Sang-Won; Lee, Kyung Soo

2015-09-01

The utility of (18)F-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning and brain magnetic resonance imaging (MRI) as a staging workup for lung adenocarcinoma manifesting as pure ground glass opacity (GGO) is unknown. The purpose of this study was to determine the utility of these 2 tests for preoperative staging of pure GGO nodular lung adenocarcinoma. The study included 164 patients (male:female, 73:91; mean age, 62 years) with pure GGO nodular lung adenocarcinoma who underwent PET/CT (in 136 patients) and/or brain MRI (in 109 patients) before surgery. Pathologic N staging and dedicated standard imaging or follow-up imaging findings for M staging were used as reference standards. The median follow-up time was 47.9 months. On PET/CT scan, abnormal FDG uptake of lymph nodes was found in 2 of 136 patients (1.5%); both were negative on final pathology. Abnormal FDG uptake of the liver was detected in 1 patient, which was also confirmed to be negative by dedicated abdominal CT. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT in detecting metastases were not applicable, 98% (95% confidence interval [CI], 94%-100%), 0% (95% CI, 0%-71%), 100% (95% CI, 97%-100%), and 98% (95% CI, 94%-100%), respectively. No brain metastasis was found in preoperative brain MRI of 109 patients. Of 109 patients, 1 (0.9%) developed brain metastasis 30 months after surgical resection. PET/CT and brain MRI is not necessary in the staging of pure GGO nodular lung adenocarcinoma. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Prediction of sentinel lymph node status using single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging of breast cancer.

Science.gov (United States)

Tomiguchi, Mai; Yamamoto-Ibusuki, Mutsuko; Yamamoto, Yutaka; Fujisue, Mamiko; Shiraishi, Shinya; Inao, Touko; Murakami, Kei-ichi; Honda, Yumi; Yamashita, Yasuyuki; Iyama, Ken-ichi; Iwase, Hirotaka

2016-02-01

Single-photon emission computed tomography (SPECT)/computed tomography (CT) improves the anatomical identification of sentinel lymph nodes (SNs). We aimed to evaluate the possibility of predicting the SN status using SPECT/CT. SN mapping using a SPECT/CT system was performed in 381 cases of clinically node-negative, operable invasive breast cancer. We evaluated and compared the values of SN mapping on SPECT/CT, the findings of other modalities and clinicopathological factors in predicting the SN status. Patients with SNs located in the Level I area were evaluated. Of the 355 lesions (94.8 %) assessed, six cases (1.6 %) were not detected using any imaging method. According to the final histological diagnosis, 298 lesions (78.2 %) were node negative and 83 lesions (21.7 %) were node positive. The univariate analysis showed that SN status was significantly correlated with the number of SNs detected on SPECT/CT in the Level I area (P = 0.0048), total number of SNs detected on SPECT/CT (P = 0.011), findings of planar lymphoscintigraphy (P = 0.011) and findings of a handheld gamma probe during surgery (P = 0.012). According to the multivariate analysis, the detection of multiple SNs on SPECT/CT imaging helped to predict SN metastasis. The number of SNs located in the Level I area detected using the SPECT/CT system may be a predictive factor for SN metastasis.

Contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography in solid pseudopapillary neoplasm of the pancreas

International Nuclear Information System (INIS)

Santhosh, Sampath; Lakshmanan, Ramesh Kumar; Sonik, Bhavay; Padmavathy, Rajagopalan; Gunaseelan, Rajamani Emmanuel

2016-01-01

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare pancreatic tumor with low malignant potential. It occurs characteristically more often in young women. Radiological and pathological studies have revealed that the tumor is quite different from other pancreatic tumors. Limited information is available in the literature reporting their accumulation of fluorine- 18 fluorodeoxyglucose ( 18 F-FDG) in positron emission tomography/computed tomography (PET/CT). Here, we report a case of pancreatic SPN imaged with contrast-enhanced FDG PET/CT. A percutaneous fine needle aspiration from the metabolically active lesion revealed SPN, and it was confirmed with histopathological results. Recurrence or metastasis was not found after 7 months of follow-up

Positron emission tomography - a new approach to brain chemistry

International Nuclear Information System (INIS)

Jacobson, H.G.

1988-01-01

Positron emission tomography permits examination of the chemistry of the brain in living beings. Until recently, positron emission tomography had been considered a research tool, but it is rapidly moving into clinical practice. This report describes the uses and applications of positron emission tomography in examinations of patients with strokes, epilepsy, malignancies, dementias, and schizophrenia and in basic studies of synaptic neurotransmission

Comparative study and implementation of images re processing methods for the tomography by positrons emission: interest of taking into account a priori information; Etude comparative et implementation de methodes de reconstruction d`images pour la tomographie par emission de positons: interet de la prise en compte d`informations a priori

Energy Technology Data Exchange (ETDEWEB)

Bouchet, F.

1996-09-25

The tomography by positron emission has for aim to explore an organ by injection of a radiotracer and bidimensional representation with processing techniques. The most used in routine is the filtered retro projection that gives smoothed images. this work realizes a comparative study of new techniques. The methods of preservations of contours are studied here, the idea is to use NMR imaging as a priori information. Two techniques of images construction are viewed more particularly: the resolution by pseudo inverse and the Bayesian method. (N.C.).

Simultaneous whole body (18)F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging for evaluation of pediatric cancer: Preliminary experience and comparison with (18)F-fluorodeoxyglucose positron emission tomography computed tomography.

Science.gov (United States)

Pugmire, Brian S; Guimaraes, Alexander R; Lim, Ruth; Friedmann, Alison M; Huang, Mary; Ebb, David; Weinstein, Howard; Catalano, Onofrio A; Mahmood, Umar; Catana, Ciprian; Gee, Michael S

2016-03-28

To describe our preliminary experience with simultaneous whole body (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography and magnetic resonance imaging (PET-MRI) in the evaluation of pediatric oncology patients. This prospective, observational, single-center study was Health Insurance Portability and Accountability Act-compliant, and institutional review board approved. To be eligible, a patient was required to: (1) have a known or suspected cancer diagnosis; (2) be under the care of a pediatric hematologist/oncologist; and (3) be scheduled for clinically indicated (18)F-FDG positron emission tomography-computed tomography (PET-CT) examination at our institution. Patients underwent PET-CT followed by PET-MRI on the same day. PET-CT examinations were performed using standard department protocols. PET-MRI studies were acquired with an integrated 3 Tesla PET-MRI scanner using whole body T1 Dixon, T2 HASTE, EPI diffusion-weighted imaging (DWI) and STIR sequences. No additional radiotracer was given for the PET-MRI examination. Both PET-CT and PET-MRI examinations were reviewed by consensus by two study personnel. Test performance characteristics of PET-MRI, for the detection of malignant lesions, including FDG maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin), were calculated on a per lesion basis using PET-CT as a reference standard. A total of 10 whole body PET-MRI exams were performed in 7 pediatric oncology patients. The mean patient age was 16.1 years (range 12-19 years) including 6 males and 1 female. A total of 20 malignant and 21 benign lesions were identified on PET-CT. PET-MRI SUVmax had excellent correlation with PET-CT SUVmax for both benign and malignant lesions (R = 0.93). PET-MRI SUVmax > 2.5 had 100% accuracy for discriminating benign from malignant lesions using PET-CT reference. Whole body DWI was also evaluated: the mean ADCmin of malignant lesions (780.2 + 326.6) was significantly lower than

Simultaneous whole body 18F-fluorodeoxyglucose positron emission tomography magnetic resonance imaging for evaluation of pediatric cancer: Preliminary experience and comparison with 18F-fluorodeoxyglucose positron emission tomography computed tomography

Science.gov (United States)

Pugmire, Brian S; Guimaraes, Alexander R; Lim, Ruth; Friedmann, Alison M; Huang, Mary; Ebb, David; Weinstein, Howard; Catalano, Onofrio A; Mahmood, Umar; Catana, Ciprian; Gee, Michael S

2016-01-01

AIM: To describe our preliminary experience with simultaneous whole body 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography and magnetic resonance imaging (PET-MRI) in the evaluation of pediatric oncology patients. METHODS: This prospective, observational, single-center study was Health Insurance Portability and Accountability Act-compliant, and institutional review board approved. To be eligible, a patient was required to: (1) have a known or suspected cancer diagnosis; (2) be under the care of a pediatric hematologist/oncologist; and (3) be scheduled for clinically indicated 18F-FDG positron emission tomography-computed tomography (PET-CT) examination at our institution. Patients underwent PET-CT followed by PET-MRI on the same day. PET-CT examinations were performed using standard department protocols. PET-MRI studies were acquired with an integrated 3 Tesla PET-MRI scanner using whole body T1 Dixon, T2 HASTE, EPI diffusion-weighted imaging (DWI) and STIR sequences. No additional radiotracer was given for the PET-MRI examination. Both PET-CT and PET-MRI examinations were reviewed by consensus by two study personnel. Test performance characteristics of PET-MRI, for the detection of malignant lesions, including FDG maximum standardized uptake value (SUVmax) and minimum apparent diffusion coefficient (ADCmin), were calculated on a per lesion basis using PET-CT as a reference standard. RESULTS: A total of 10 whole body PET-MRI exams were performed in 7 pediatric oncology patients. The mean patient age was 16.1 years (range 12-19 years) including 6 males and 1 female. A total of 20 malignant and 21 benign lesions were identified on PET-CT. PET-MRI SUVmax had excellent correlation with PET-CT SUVmax for both benign and malignant lesions (R = 0.93). PET-MRI SUVmax > 2.5 had 100% accuracy for discriminating benign from malignant lesions using PET-CT reference. Whole body DWI was also evaluated: the mean ADCmin of malignant lesions (780.2 + 326.6) was

Imaging of cellular proliferation in liver metastasis by [18F]fluorothymidine positron emission tomography: effect of therapy

International Nuclear Information System (INIS)

Contractor, Kaiyumars; Challapalli, Amarnath; Tomasi, Giampaolo; Rosso, Lula; Stebbing, Justin; Kenny, Laura; Palmieri, Carlo; Sharma, Rohini; Turkheimer, Federico; Coombes, R Charles; Aboagye, Eric; Wasan, Harpreet; Mangar, Stephen; Riddle, Pippa; Al-Nahhas, Adil

2012-01-01

Although [ 18 F]fluorothymidine positron emission tomography (FLT-PET) permits estimation of tumor thymidine kinase-1 expression, and thus, cell proliferation, high physiological uptake of tracer in liver tissue can limit its utility. We evaluated FLT-PET combined with a temporal-intensity information-based voxel-clustering approach termed kinetic spatial filtering (FLT-PET KSF ) for detecting drug response in liver metastases. FLT-PET and computed tomography data were collected from patients with confirmed breast or colorectal liver metastases before, and two weeks after the first cycle of chemotherapy. Changes in tumor FLT-PET and FLT-PET KSF variables were determined. Visual distinction between tumor and normal liver was seen in FLT-PET KSF images. Of the 33 metastases from 20 patients studied, 26 were visible after kinetic filtering. The net irreversible retention of the tracer (Ki; from unfiltered data) in the tumor, correlated strongly with tracer uptake when the imaging variable was an unfiltered average or maximal standardized uptake value, 60 min post-injection (SUV 60,av : r = 0.9, SUV 60,max : r = 0.7; p KSF (r = 0.7, p KSF detected changes in proliferation in liver metastases. (paper)

Imaging of cellular proliferation in liver metastasis by [18F]fluorothymidine positron emission tomography: effect of therapy

Science.gov (United States)

Contractor, Kaiyumars; Challapalli, Amarnath; Tomasi, Giampaolo; Rosso, Lula; Wasan, Harpreet; Stebbing, Justin; Kenny, Laura; Mangar, Stephen; Riddle, Pippa; Palmieri, Carlo; Al-Nahhas, Adil; Sharma, Rohini; Turkheimer, Federico; Coombes, R. Charles; Aboagye, Eric

2012-06-01

Although [18F]fluorothymidine positron emission tomography (FLT-PET) permits estimation of tumor thymidine kinase-1 expression, and thus, cell proliferation, high physiological uptake of tracer in liver tissue can limit its utility. We evaluated FLT-PET combined with a temporal-intensity information-based voxel-clustering approach termed kinetic spatial filtering (FLT-PETKSF) for detecting drug response in liver metastases. FLT-PET and computed tomography data were collected from patients with confirmed breast or colorectal liver metastases before, and two weeks after the first cycle of chemotherapy. Changes in tumor FLT-PET and FLT-PETKSF variables were determined. Visual distinction between tumor and normal liver was seen in FLT-PETKSF images. Of the 33 metastases from 20 patients studied, 26 were visible after kinetic filtering. The net irreversible retention of the tracer (Ki; from unfiltered data) in the tumor, correlated strongly with tracer uptake when the imaging variable was an unfiltered average or maximal standardized uptake value, 60 min post-injection (SUV60,av: r = 0.9, SUV60,max: r = 0.7; p benefit from chemotherapy. FLT-PET and FLT-PETKSF detected changes in proliferation in liver metastases.

Sparse image representation for jet neutron and gamma tomography

Energy Technology Data Exchange (ETDEWEB)

Craciunescu, T. [EURATOM-MEdC Association, Institute for Laser, Plasma and Radiation Physics, Bucharest (Romania); Kiptily, V. [EURATOM/CCFE Association, Culham Science Centre, Abingdon (United Kingdom); Murari, A. [Consorzio RFX, Associazione EURATOM-ENEA per la Fusione, Padova (Italy); Tiseanu, I.; Zoita, V. [EURATOM-MEdC Association, Institute for Laser, Plasma and Radiation Physics, Bucharest (Romania)

2013-10-15

Highlights: •A new tomographic method for the reconstruction of the 2-D neutron and gamma emissivity on JET. •The method is based on the sparse representation of the reconstructed image in an over-complete dictionary. •Several techniques, based on a priori information are used to regularize this highly limited data set tomographic problem. •The proposed method provides good reconstructions in terms of shapes and resolution. -- Abstract: The JET gamma/neutron profile monitor plasma coverage of the emissive region enables tomographic reconstruction. However, due to the availability of only two projection angles and to the coarse sampling, tomography is a highly limited data set problem. A new reconstruction method, based on the sparse representation of the reconstructed image in an over-complete dictionary, has been developed and applied to JET neutron/gamma tomography. The method has been tested on JET experimental data and significant results are presented. The proposed method provides good reconstructions in terms of shapes and resolution.

Magnetic resonance imaging-guided attenuation correction of positron emission tomography data in PET/MRI

Science.gov (United States)

Izquierdo-Garcia, David; Catana, Ciprian

2018-01-01

Synopsis Attenuation correction (AC) is one of the most important challenges in the recently introduced combined positron emission tomography/magnetic resonance imaging (PET/MR) scanners. PET/MR AC (MR-AC) approaches aim to develop methods that allow accurate estimation of the linear attenuation coefficients (LACs) of the tissues and other components located in the PET field of view (FoV). MR-AC methods can be divided into three main categories: segmentation-, atlas- and PET-based. This review aims to provide a comprehensive list of the state of the art MR-AC approaches as well as their pros and cons. The main sources of artifacts such as body-truncation, metallic implants and hardware correction will be presented. Finally, this review will discuss the current status of MR-AC approaches for clinical applications. PMID:26952727

Carbon-11 and Fluorine-18 Labeled Amino Acid Tracers for Positron Emission Tomography Imaging of Tumors

Science.gov (United States)

Sun, Aixia; Liu, Xiang; Tang, Ganghua

2017-12-01

Tumor cells have an increased nutritional demand for amino acids(AAs) to satisfy their rapid proliferation. Positron-emitting nuclide labeled AAs are interesting probes and are of great importance for imaging tumors using positron emission tomography (PET). Carbon-11 and fluorine-18 labeled AAs include the [1-11C] amino acids, labeling alpha-C- amino acids, the branched-chain of amino acids and N-substituted carbon-11 labeled amino acids. These tracers target protein synthesis or amino acid(AA) transport, and their uptake mechanism mainly involves AA transport. AA PET tracers have been widely used in clinical settings to image brain tumors, neuroendocrine tumors, prostate cancer, breast cancer, non–small cell lung cancer (NSCLC) and hepatocellular carcinoma. This review focuses on the fundamental concepts and the uptake mechanism of AAs, AA PET tracers and their clinical applications.

Positron emission tomography of malignant tumours at head and neck. Evaluation of the diagnostic value of positron emission tomography by comparison with computed tomography; Positronenemissionstomographie bei malignen Tumoren im Kopf- und Halsbereich. Beurteilung der diagnostischen Wertigkeit der Positronenemissionstomographie im Vergleich zur Computertomographie

Energy Technology Data Exchange (ETDEWEB)

Kettler, Nele

2011-12-02

Imaging methods for early, accurate diagnosis and aftercare of malignant growths is currently one of the most important research topics. The objective of this thesis is to evaluate the diagnostic value of FDG-positron emission tomography by comparison with computed tomography for patients with squamous cell carcinoma, malignant melanoma or sarcoma at head and neck. Measurement criteria are sensitivity and specificity. A retrospective evaluation of 100 examinations on 85 patients of University clinic Aachen was performed. The examination reports were supported by reports from histology, positron emission tomography and computed tomography. In each case, the histological results were assumed to provide a reliable benchmark. Sensitivity and specificity for the primary tumour site, metastatic lymphatic nodes and defined anatomic structures were compared across all patients. Comparisons were also performed on sub groups separated by gender, cancer type and the time and frequency at which tumours arose. The statistic analysis was done with MedCalc. Results: The results for sensitivity and specificity of the primary tumour site were 86.42% and 42.86%, and 64.71% and 66.07%, for positron emission tomography and computed tomography respectively. The results for the lymphatic nodes were 51.52% and 92.86% and 64.71% and 66.07%. When the constituent anatomic structures were evaluated separately, the specificity was significantly higher. The separation by gender showed no difference. Because the classification by tumor type resulted in samples that were of varying size, a comparison was difficult. For the diagnosis of primary tumours, the examination with positron emission tomography was superior, whereas computed tomography proved more effective for the diagnosis of recurrent tumours. For the diagnosis of the main tumour site, both methods were shown to be equally suitable. For the assessment of lymphatic nodes, positron emission tomography was superior to computed tomography

Positron emission tomography

International Nuclear Information System (INIS)

Pavuk, M.

2003-12-01

The aim of this project is to provide a simple summary of new trends in positron emission tomography and its basic physical principles. It provides thereby compendious introduction of the trends of the present development in diagnostics using PET systems. A review of available literature was performed. (author)

18 F-Labeling of Sensitive Biomolecules for Positron Emission Tomography.

Science.gov (United States)

Krishnan, Hema S; Ma, Longle; Vasdev, Neil; Liang, Steven H

2017-11-07

Positron emission tomography (PET) imaging study of fluorine-18 labeled biomolecules is an emerging and rapidly growing area for preclinical and clinical research. The present review focuses on recent advances in radiochemical methods for incorporating fluorine-18 into biomolecules via "direct" or "indirect" bioconjugation. Recently developed prosthetic groups and pre-targeting strategies, as well as representative examples in 18 F-labeling of biomolecules in PET imaging research studies are highlighted. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Imaging spectrum and pitfalls of 11C-methionine position emission tomography in a series of patients with intracranial lesions

International Nuclear Information System (INIS)

Ito, Kimiteru; Matsuda, Hiroshi; Kubota, Kazoo

2016-01-01

11 C-methionine (Met) positron emission tomography (PET) is one of the most commonly used PET tracers for evaluating brain tumors. However, few reports have described tips and pitfalls of 11 C-Met PET for general practitioners. Physiological 11 C-Met uptake, anatomical variations, vascular disorders, non-tumorous lesions such as inflammation or dysplasia, benign brain tumors and patient condition during 11 C-Met PET examination can potentially affect the image interpretation and cause false positives and negatives. These pitfalls in the interpretation of 11 C-Met PET images are important for not only nuclear medicine physicians but also general radiologists. Familiarity with the spectrum and pitfalls of 11 C-Met images could help prevent unfavorable clinical results caused by misdiagnoses

Imaging Spectrum and Pitfalls of (11)C-Methionine Positron Emission Tomography in a Series of Patients with Intracranial Lesions.

Science.gov (United States)

Ito, Kimiteru; Matsuda, Hiroshi; Kubota, Kazoo

2016-01-01

(11)C-methionine (Met) positron emission tomography (PET) is one of the most commonly used PET tracers for evaluating brain tumors. However, few reports have described tips and pitfalls of (11)C-Met PET for general practitioners. Physiological (11)C-Met uptake, anatomical variations, vascular disorders, non-tumorous lesions such as inflammation or dysplasia, benign brain tumors and patient condition during (11)C-Met PET examination can potentially affect the image interpretation and cause false positives and negatives. These pitfalls in the interpretation of (11)C-Met PET images are important for not only nuclear medicine physicians but also general radiologists. Familiarity with the spectrum and pitfalls of (11)C-Met images could help prevent unfavorable clinical results caused by misdiagnoses.

Patient study of in vivo verification of beam delivery and range, using positron emission tomography and computed tomography imaging after proton therapy

NARCIS (Netherlands)

Parodi, Katia; Paganetti, Harald; Shih, Helen A; Michaud, Susan; Loeffler, Jay S; DeLaney, Thomas F; Liebsch, Norbert J; Munzenrider, John E; Fischman, Alan J; Knopf, Antje; Bortfeld, Thomas

2007-01-01

PURPOSE: To investigate the feasibility and value of positron emission tomography and computed tomography (PET/CT) for treatment verification after proton radiotherapy. METHODS AND MATERIALS: This study included 9 patients with tumors in the cranial base, spine, orbit, and eye. Total doses of 1.8-3

Contribution of positron emission tomography in pleural disease.

Science.gov (United States)

Duysinx, B; Corhay, J-L; Larock, M-P; Withofs, N; Bury, T; Hustinx, R; Louis, R

2010-10-01

Positron emission tomography (PET) now plays a clear role in oncology, especially in chest tumours. We discuss the value of metabolic imaging in characterising pleural pathology in the light of our own experience and review the literature. PET is particularly useful in characterising malignant pleural pathologies and is a factor of prognosis in mesothelioma. Metabolic imaging also provides clinical information for staging lung cancer, in researching the primary tumour in metastatic pleurisy and in monitoring chronic or recurrent pleural pathologies. PET should therefore be considered as a useful tool in the diagnosis of liquid or solid pleural pathologies. Copyright © 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Positron emission tomography in the management of cervix cancer patients; Tomographie par emission de positons dans la prise en charge des cancers du col de l'uterus

Energy Technology Data Exchange (ETDEWEB)

Bonardel, G.; Gontier, E.; Soret, M.; Dechaud, C.; Fayolle, M.; Foehrenbach, H. [Hopital d' Instruction des Armees du Val-de-Grace, Service de Medecine Nucleaire, 75 - Paris (France); Chargari, C.; Bauduceau, O. [Hopital d' Instruction des Armees du Val-de-Grace, Service de Radiotherapie, 75 - Paris (France)

2009-10-15

Since its introduction in clinical practice in the 1990 s, positron emission tomography (PET), usually with {sup 18}F-fluoro-2-deoxy-D-glucose ({sup 18}F-F.D.G.), has become an important imaging modality in patients with cancer. For cervix carcinoma, F.D.G.-PET is significantly more accurate than computed tomography (CT) and is recommended for loco-regional lymph node and extra pelvic staging. The metabolic dimension of the technique provides additional prognostic information. Ongoing studies now concentrate on more advanced clinical applications, such as the planning of radiotherapy, the response evaluation after the induction of therapy, the early detection of recurrence. Technical innovations, such as PET cameras with better spatial resolution and hybrid positron emission tomography/computed tomography (PET-CT), available now on the whole territory, provide both anatomic and metabolic information in the same procedure. From the point of view of biological metabolism, new radiopharmaceutical probes are being developed. Those hold promise for future refinements in this field. This article reviews the current applications of F.D.G.-PET in patients with cervix cancer. (authors)

Positron emission tomography and migraine

International Nuclear Information System (INIS)

Chabriat, H.

1992-01-01

Positron emission tomography (PET) is a brain imaging technique that allows in vivo studies of numerous physiological parameters. There have been few PET studies in migraine patients. Cerebral blood flow changes with no variations in brain oxygen consumption have been reported in patients with prolonged neurologic manifestations during migraine attacks. Parenteral administration of reserpine during migraine headache has been followed by a fall in the overall cerebral uptake of glucose. The small sample sizes and a number of methodologic problems complicate the interpretation of these results. Recent technical advances and the development of new PET tracers can be expected to provide further insight into the pathophysiology of migraine. Today cerebral cortex 5 HT 2 serotonin receptors can be studied in migraine patients with PET

Molecular Imaging Probes for Positron Emission Tomography and Optical Imaging of Sentinel Lymph Node and Tumor

Science.gov (United States)

Qin, Zhengtao

Molecular imaging is visualizations and measurements of in vivo biological processes at the molecular or cellular level using specific imaging probes. As an emerging technology, biocompatible macromolecular or nanoparticle based targeted imaging probes have gained increasing popularities. Those complexes consist of a carrier, an imaging reporter, and a targeting ligand. The active targeting ability dramatically increases the specificity. And the multivalency effect may further reduce the dose while providing a decent signal. In this thesis, sentinel lymph node (SLN) mapping and cancer imaging are two research topics. The focus is to develop molecular imaging probes with high specificity and sensitivity, for Positron Emission Tomography (PET) and optical imaging. The objective of this thesis is to explore dextran radiopharmaceuticals and porous silicon nanoparticles based molecular imaging agents. Dextran polymers are excellent carriers to deliver imaging reporters or therapeutic agents due to its well established safety profile and oligosaccharide conjugation chemistry. There is also a wide selection of dextran polymers with different lengths. On the other hand, Silicon nanoparticles represent another class of biodegradable materials for imaging and drug delivery. The success in fluorescence lifetime imaging and enhancements of the immune activation potency was briefly discussed. Chapter 1 begins with an overview on current molecular imaging techniques and imaging probes. Chapter 2 presents a near-IR dye conjugated probe, IRDye 800CW-tilmanocept. Fluorophore density was optimized to generate the maximum brightness. It was labeled with 68Ga and 99mTc and in vivo SLN mapping was successfully performed in different animals, such as mice, rabbits, dogs and pigs. With 99mTc labeled IRDye 800CW-tilmanocept, chapter 3 introduces a two-day imaging protocol with a hand-held imager. Chapter 4 proposed a method to dual radiolabel the IRDye 800CW-tilmanocept with both 68Ga and

Automatic segmentation of dynamic neuroreceptor single-photon emission tomography images using fuzzy clustering

International Nuclear Information System (INIS)

Acton, P.D.; Pilowsky, L.S.; Kung, H.F.; Ell, P.J.

1999-01-01

The segmentation of medical images is one of the most important steps in the analysis and quantification of imaging data. However, partial volume artefacts make accurate tissue boundary definition difficult, particularly for images with lower resolution commonly used in nuclear medicine. In single-photon emission tomography (SPET) neuroreceptor studies, areas of specific binding are usually delineated by manually drawing regions of interest (ROIs), a time-consuming and subjective process. This paper applies the technique of fuzzy c-means clustering (FCM) to automatically segment dynamic neuroreceptor SPET images. Fuzzy clustering was tested using a realistic, computer-generated, dynamic SPET phantom derived from segmenting an MR image of an anthropomorphic brain phantom. Also, the utility of applying FCM to real clinical data was assessed by comparison against conventional ROI analysis of iodine-123 iodobenzamide (IBZM) binding to dopamine D 2 /D 3 receptors in the brains of humans. In addition, a further test of the methodology was assessed by applying FCM segmentation to [ 123 I]IDAM images (5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio] benzyl alcohol) of serotonin transporters in non-human primates. In the simulated dynamic SPET phantom, over a wide range of counts and ratios of specific binding to background, FCM correlated very strongly with the true counts (correlation coefficient r 2 >0.99, P 123 I]IBZM data comparable with manual ROI analysis, with the binding ratios derived from both methods significantly correlated (r 2 =0.83, P<0.0001). Fuzzy clustering is a powerful tool for the automatic, unsupervised segmentation of dynamic neuroreceptor SPET images. Where other automated techniques fail completely, and manual ROI definition would be highly subjective, FCM is capable of segmenting noisy images in a robust and repeatable manner. (orig.)

Imaging of the pancreas using dynamic positron emission tomography with N-13 ammonia

International Nuclear Information System (INIS)

Hayashi, N.; Tamaki, N.; Yonekura, Y.; Adachi, H.; Senda, M.; Saji, H.; Torizuka, K.

1985-01-01

This study was undertaken to develop a new imaging technique of the pancreas. Dynamic positron emission tomography (PET) was performed in 3 normal volunteers, 9 patient without the evidence of pancreatic diseases, 2 patients with adenocarcinoma of the pancreatic head and one patient with islet cell carcinoma. Immediately after the intravenous injection of 10-20mCi of N-13 ammonia, data were obtained every 150 seconds for 30 minutes using a multi-slice whole-body PET scanner. In two cases of adenocarcinoma, the pancreas was not imaged, probably because the nontumorous portion of the pancreas was also suffered from severe pancreatitis due to the duct obstruction at the pancreatic head. In the case with islet cell carcinoma, the radionuclide was accumulated in the tumor and pancreas similarly. Thus, both of them were visualized but not separated. The central necrosis of the tumor showed poor radioactivity. The mechanism of the radionuclide accumulation in the pancreas is not well understood. However, the authors also studied the biodistribution of N-13 ammonia in mice and confirmed that there is an early and high accumulation of the radionuclide in the murine pancreas. These preliminary results of this paper suggest that the dynamic PET study may be useful for the imaging of the pancreas as well as for the further study of the blood supply and metabolism of the pancreas

Therapeutic impact of [18F]fluoride positron-emission tomography/computed tomography on patients with unclear foot pain

International Nuclear Information System (INIS)

Fischer, Dorothee Rita; Hesselmann, Rolf; Johayem, Anass; Hany, Thomas F.; Schulthess, Gustav K. von; Strobel, Klaus; Maquieira, Gerardo J.; Espinosa, Norman; Zanetti, Marco

2010-01-01

To evaluate the therapeutic impact of [ 18 F]fluoride positron-emission tomography/computed tomography ([ 18 F]fluoride PET/CT) imaging on patients with unclear foot pain. Twenty-eight patients were prospectively included in this study. Therapeutic management was defined by two experienced dedicated foot surgeons before and after [ 18 F]fluoride PET/CT imaging. Twenty-six patients underwent cross-sectional imaging [CT, magnetic resonance (MR)] prior to PET/CT. A retrospective analysis of the magnetic resonance imaging (MRI) diagnoses was performed when a therapy change occurred after PET/CT imaging. In 13/28 (46%) patients therapeutic management was changed due to PET/CT results. Management changes occurred in patients with the following diagnoses: os trigonum syndrome; sinus tarsi syndrome; os tibiale externum syndrome; osteoarthritis of several joints; non-consolidated fragments; calcaneo-navicular coalition; plantar fasciitis; insertional tendinopathy; suggestion of periostitis; neoarticulations between metatarsal bones. Os trigonum, os tibiale externum, subtalar osteoarthritis and plantar fasciitis were only seen to be active on PET/CT images but not on MR images. [ 18 F]fluoride PET/CT has a substantial therapeutic impact on management in patients with unclear foot pain. (orig.)

Positron emission tomography/computed tomography scanning for ...

African Journals Online (AJOL)

Background: Although the site of nosocomial sepsis in the critically ill ventilated patient is usually identifiable, it may remain occult, despite numerous investigations. The rapid results and precise anatomical location of the septic source using positron emission tomography (PET) scanning, in combination with computed ...

The efficacy of preoperative positron emission tomography-computed tomography (PET-CT) for detection of lymph node metastasis in cervical and endometrial cancer: clinical and pathological factors influencing it.

Science.gov (United States)

Nogami, Yuya; Banno, Kouji; Irie, Haruko; Iida, Miho; Kisu, Iori; Masugi, Yohei; Tanaka, Kyoko; Tominaga, Eiichiro; Okuda, Shigeo; Murakami, Koji; Aoki, Daisuke

2015-01-01

We studied the diagnostic performance of (18)F-fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography in cervical and endometrial cancers with particular focus on lymph node metastases. Seventy patients with cervical cancer and 53 with endometrial cancer were imaged with (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography before lymphadenectomy. We evaluated the diagnostic performance of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography using the final pathological diagnoses as the golden standard. We calculated the sensitivity, specificity, positive predictive value and negative predictive value of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography. In cervical cancer, the results evaluated by cases were 33.3, 92.7, 55.6 and 83.6%, respectively. When evaluated by the area of lymph nodes, the results were 30.6, 98.9, 55.0 and 97.0%, respectively. As for endometrial cancer, the results evaluated by cases were 50.0, 93.9, 40.0 and 95.8%, and by area of lymph nodes, 45.0, 99.4, 64.3 and 98.5%, respectively. The limitation of the efficacy was found out by analyzing it by the region of the lymph node, the size of metastatic node, the historical type of tumor in cervical cancer and the prevalence of lymph node metastasis. The efficacy of positron emission tomography/computed tomography regarding the detection of lymph node metastasis in cervical and endometrial cancer is not established and has limitations associated with the region of the lymph node, the size of metastasis lesion in lymph node and the pathological type of primary tumor. The indication for the imaging and the interpretation of the results requires consideration for each case by the pretest probability based on the information obtained preoperatively. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Instrumentation for positron emission tomography

International Nuclear Information System (INIS)

Budinger, T.F.; Derenzo, S.E.; Huesman, R.H.

1984-01-01

Positron emission tomography with a spatial resolution of 2 mm full width at half maximum for quantitation in regions of interest 4 mm in diameter will become possible with the development of detectors that achieve ultrahigh resolution. Improved resolution will be possible using solid-state photodetectors for crystal identification or photomultiplier tubes with many small electron multipliers. Temporal resolution of 2 seconds and gating of cyclic events can be accomplished if statistical requirements are met. The major physical considerations in achieving high-resolution positron emission tomography are the degradation in resolution resulting from positron range, emission angle, parallax error, detector sampling density, the sensitivity of various detector materials and packing schemes, and the tradeoff between temporal resolution and statistical accuracy. The accuracy of data required for physiological models depends primarily on the fidelity of spatial sampling independent of statistical constraints

Positron emission tomography with additional γ-ray detectors for multiple-tracer imaging.

Science.gov (United States)

Fukuchi, Tomonori; Okauchi, Takashi; Shigeta, Mika; Yamamoto, Seiichi; Watanabe, Yasuyoshi; Enomoto, Shuichi

2017-06-01

Positron emission tomography (PET) is a useful imaging modality that quantifies the physiological distributions of radiolabeled tracers in vivo in humans and animals. However, this technique is unsuitable for multiple-tracer imaging because the annihilation photons used for PET imaging have a fixed energy regardless of the selection of the radionuclide tracer. This study developed a multi-isotope PET (MI-PET) system and evaluated its imaging performance. Our MI-PET system is composed of a PET system and additional γ-ray detectors. The PET system consists of pixelized gadolinium orthosilicate (GSO) scintillation detectors and has a ring geometry that is 95 mm in diameter with an axial field of view of 37.5 mm. The additional detectors are eight bismuth germanium oxide (BGO) scintillation detectors, each of which is 50 × 50 × 30 mm 3 , arranged into two rings mounted on each side of the PET ring with a 92-mm-inner diameter. This system can distinguish between different tracers using the additional γ-ray detectors to observe prompt γ-rays, which are emitted after positron emission and have an energy intrinsic to each radionuclide. Our system can simultaneously acquire double- (two annihilation photons) and triple- (two annihilation photons and a prompt γ-ray) coincidence events. The system's efficiency for detecting prompt de-excitation γ-rays was measured using a positron-γ emitter, 22 Na. Dual-radionuclide ( 18 F and 22 Na) imaging of a rod phantom and a mouse was performed to demonstrate the performance of the developed system. Our system's basic performance was evaluated by reconstructing two images, one containing both tracers and the other containing just the second tracer, from list-mode data sets that were categorized by the presence or absence of the prompt γ-ray. The maximum detection efficiency for 1275 keV γ-rays emitted from 22 Na was approximately 7% at the scanner's center, and the minimum detection efficiency was 5.1% at the edge of

Representation of photon limited data in emission tomography using origin ensembles

OpenAIRE

Sitek, A

2008-01-01

Representation and reconstruction of data obtained by emission tomography scanners are challenging due to high noise levels in the data. Typically, images obtained using tomographic measurements are represented using grids. In this work, we define images as sets of origins of events detected during tomographic measurements; we call these origin ensembles (OEs). A state in the ensemble is characterized by a vector of 3N parameters Y, where the parameters are the coordinates of origins of detec...

Fast Neutron Emission Tomography of Used Nuclear Fuel Assemblies

Science.gov (United States)

Hausladen, Paul; Iyengar, Anagha; Fabris, Lorenzo; Yang, Jinan; Hu, Jianwei; Blackston, Matthew

2017-09-01

Oak Ridge National Laboratory is developing a new capability to perform passive fast neutron emission tomography of spent nuclear fuel assemblies for the purpose of verifying their integrity for international safeguards applications. Most of the world's plutonium is contained in spent nuclear fuel, so it is desirable to detect the diversion of irradiated fuel rods from an assembly prior to its transfer to ``difficult to access'' storage, such as a dry cask or permanent repository, where re-verification is practically impossible. Nuclear fuel assemblies typically consist of an array of fuel rods that, depending on exposure in the reactor and consequent ingrowth of 244Cm, are spontaneous sources of as many as 109 neutrons s-1. Neutron emission tomography uses collimation to isolate neutron activity along ``lines of response'' through the assembly and, by combining many collimated views through the object, mathematically extracts the neutron emission from each fuel rod. This technique, by combining the use of fast neutrons -which can penetrate the entire fuel assembly -and computed tomography, is capable of detecting vacancies or substitutions of individual fuel rods. This paper will report on the physics design and component testing of the imaging system. This material is based upon work supported by the U.S. Department of Energy, Office of Defense Nuclear Nonproliferation Research and Development within the National Nuclear Security Administration, under Contract Number DE-AC05-00OR22725.

Characterization of hepatic tumors using [11C]metomidate through positron emission tomography

DEFF Research Database (Denmark)

Roivainen, Anne; Naum, Alexandru; Nuutinen, Heikki

2013-01-01

ABSTRACT: BACKGROUND: Using positron emission tomography (PET), we compared two tracers, [11C]metomidate ([11C]MTO) and [11C]acetate ([11C]ACE), for the characterization of hepatic tumors. METHODS: Thirty-three patients underwent PET with [11C]MTO and [11C]ACE and magnetic resonance imaging (MRI...

Tomography by positrons emission: integral unit to the service of Mexico

International Nuclear Information System (INIS)

Lopez D, F.A.

2005-01-01

The applications of the Positron emission tomography (PET) together with the one radiopharmaceutical 2 - [ 18 F]-fluoro-2-deoxy-D-glucose in the area of the medical imaging is expanding quickly and it possesses a bigger impact at the moment in favor of those patient to who suffers an oncological, cardiac or neurological illness in Mexico. (Author)

Imaging for carbon translocation to a fruit of tomato with carbon-11-labeled carbon dioxide and positron emission tomography

International Nuclear Information System (INIS)

Kawachi, N.; Suzui, N.; Ishii, S.; Fujimaki, S.; Ishioka, N.; Kikuchi, K.; Watanbe, H.

2009-01-01

Carbon kinetics in the fruit is an agricultural issue on the growth and development of the fruit to be harvested. Particularly, photo-assimilate translocation and distribution are important topics for understanding the mechanism. In the present work, carbon-11 ( 11 C) labeled photo-assimilate translocation into fruits of tomato has been imaged using carbon-11-labeled carbon dioxide and the positron emission tomography (PET). Dynamic PET data of gradual increasing of 11 C activity and its distribution is acquired quantitatively in intact plant body. This indicates that the three dimensional photo-assimilate translocation into the fruits is imaged successfully and carbon kinetics is analyzed to understand the plant physiology and nutrition. (authors)

Positron emission tomography/magnetic resonance hybrid scanner imaging of cerebral blood flow using ¹⁵O-water positron emission tomography and arterial spin labeling magnetic resonance imaging in newborn piglets

DEFF Research Database (Denmark)

Andersen, Julie B; Henning, William S; Lindberg, Ulrich

2015-01-01

Abnormality in cerebral blood flow (CBF) distribution can lead to hypoxic-ischemic cerebral damage in newborn infants. The aim of the study was to investigate minimally invasive approaches to measure CBF by comparing simultaneous (15)O-water positron emission tomography (PET) and single TI pulsed...

Design of a portable optical emission tomography system for microwave induced compact plasma for visible to near-infrared emission lines

Energy Technology Data Exchange (ETDEWEB)

Rathore, Kavita, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in; Munshi, Prabhat, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in [Nuclear Engineering and Technology Programme, Indian Institute of Technology Kanpur, Kanpur (India); Bhattacharjee, Sudeep, E-mail: kavira@iitk.ac.in, E-mail: pmunshi@iitk.ac.in, E-mail: sudeepb@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

2016-03-15

A new non-invasive diagnostic system is developed for Microwave Induced Plasma (MIP) to reconstruct tomographic images of a 2D emission profile. A compact MIP system has wide application in industry as well as research application such as thrusters for space propulsion, high current ion beams, and creation of negative ions for heating of fusion plasma. Emission profile depends on two crucial parameters, namely, the electron temperature and density (over the entire spatial extent) of the plasma system. Emission tomography provides basic understanding of plasmas and it is very useful to monitor internal structure of plasma phenomena without disturbing its actual processes. This paper presents development of a compact, modular, and versatile Optical Emission Tomography (OET) tool for a cylindrical, magnetically confined MIP system. It has eight slit-hole cameras and each consisting of a complementary metal–oxide–semiconductor linear image sensor for light detection. The optical noise is reduced by using aspheric lens and interference band-pass filters in each camera. The entire cylindrical plasma can be scanned with automated sliding ring mechanism arranged in fan-beam data collection geometry. The design of the camera includes a unique possibility to incorporate different filters to get the particular wavelength light from the plasma. This OET system includes selected band-pass filters for particular argon emission 750 nm, 772 nm, and 811 nm lines and hydrogen emission H{sub α} (656 nm) and H{sub β} (486 nm) lines. Convolution back projection algorithm is used to obtain the tomographic images of plasma emission line. The paper mainly focuses on (a) design of OET system in detail and (b) study of emission profile for 750 nm argon emission lines to validate the system design.

¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography for the evaluation of bone metastasis in patients with gastric cancer.

Science.gov (United States)

Ma, Dae Won; Kim, Jie-Hyun; Jeon, Tae Joo; Lee, Yong Chan; Yun, Mijin; Youn, Young Hoon; Park, Hyojin; Lee, Sang In

2013-09-01

The roles of positron emission tomography and bone scanning in identifying bone metastasis in gastric cancer are unclear. We compared the usefulness of positron emission tomography-computed tomography and scanning in detecting bone metastasis in gastric cancer. Data from 1485 patients diagnosed with gastric cancer who had undergone positron emission tomography-computed tomography and scanning were reviewed. Of 170 enrolled patients who were suspected of bone metastasis in either positron emission tomography or scanning, 81.2% were confirmed to have bone metastasis. The sensitivity, specificity, and accuracy were 93.5%, 25.0%, and 80.6%, respectively, for positron emission tomography and 93.5%, 37.5%, and 82.9%, respectively, for scanning. 87.7% of patients with bone metastasis showed positive findings on two modalities. 15.0% of solitary bone metastases were positive on positron emission tomography only. Positron emission tomography was superior to scanning for the detection of synchronous bone metastasis, but the two modalities were similar for the detection of metachronous bone metastasis. The concordance rate of response assessment after treatment between two modalities was moderate. Positron emission tomography-computed tomography may be more effective for the diagnosis of bone metastasis in the initial staging workup. Conversely, bone scanning and positron emission tomography-computed tomography may be similarly effective for the detection of metachronous bone metastasis. Copyright © 2013 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Technical aspects of positron emission tomography/computed tomography in radiotherapy treatment planning.

Science.gov (United States)

Scripes, Paola G; Yaparpalvi, Ravindra

2012-09-01

The usage of functional data in radiation therapy (RT) treatment planning (RTP) process is currently the focus of significant technical, scientific, and clinical development. Positron emission tomography (PET) using ((18)F) fluorodeoxyglucose is being increasingly used in RT planning in recent years. Fluorodeoxyglucose is the most commonly used radiotracer for diagnosis, staging, recurrent disease detection, and monitoring of tumor response to therapy (Lung Cancer 2012;76:344-349; Lung Cancer 2009;64:301-307; J Nucl Med 2008;49:532-540; J Nucl Med 2007;48:58S-67S). All the efforts to improve both PET and computed tomography (CT) image quality and, consequently, lesion detectability have a common objective to increase the accuracy in functional imaging and thus of coregistration into RT planning systems. In radiotherapy, improvement in target localization permits reduction of tumor margins, consequently reducing volume of normal tissue irradiated. Furthermore, smaller treated target volumes create the possibility of dose escalation, leading to increased chances of tumor cure and control. This article focuses on the technical aspects of PET/CT image acquisition, fusion, usage, and impact on the physics of RTP. The authors review the basic elements of RTP, modern radiation delivery, and the technical parameters of coregistration of PET/CT into RT computerized planning systems. Copyright © 2012 Elsevier Inc. All rights reserved.

Single photon emission computed tomography in children with idiopathic seizures

International Nuclear Information System (INIS)

Hara, Masafumi; Takahashi, Mutsumasa; Kojima, Akihiro; Shimomura, Osamu; Kinoshita, Rumi; Tomiguchi, Seiji; Taku, Keiichi; Miike, Teruhisa

1991-01-01

Single photon emission computed tomography (SPECT) with N-isoprophyl-p [ 123 I]-iodoamphetamine (IMP), X-ray computed tomography (X-CT), and magnetic resonance imaging (MRI) were performed in 20 children with idiopathic seizures. In children with idiopathic seizures, SPECT could detect the abnormal sites at the highest rate (45%) compared with CT (10%) and MRI (12%), but the abnormal sites on SPECT correlated poorly with the foci on electroencephalograph (EEG). Idiopathic epilepsy with hypoperfusion on SPECT was refractory to treatment and was frequently associated with mental and/or developmental retardation. Perfusion defects on SPECT scans probably affect the development and maturation of the brain in children. (author)

Single photon emission computed tomography of the liver

International Nuclear Information System (INIS)

Makler, P.T. Jr.

1988-01-01

Single photon emission computed tomography (SPECT) of the liver has been introduced in order to improve sensitivity and localization of space-occupying lesions. There have been numerous reports on the usefulness of the technique, as well as extensive analyses of its technical drawbacks. In general, SPECT provides a more accurate estimation of defect size than does conventional planar scintigraphy for cases in which one wishes to evaluate changes in lesion size due to therapy. The presence of a superimposed parenchymal disease, however, remains a major problem, which will only be resolved by a scanning technique that specifically detects the disease process of concern (hot spot imaging) rather than displacement of normal tissue (cold spot imaging)

Positron emission tomography

International Nuclear Information System (INIS)

Paans, A.M.J.

1981-01-01

Positron emitting radiopharmaceuticals have special applications in in-vivo studies of biochemical processes. The combination of a cyclotron for the production of radionuclides and a positron emission tomograph for the registration of the distribution of radioactivity in the body enables the measurement of local radioactivity concentration in tissues, and opens up new possibilities in the diagnosis and examination of abnormalities in the metabolism. The principles and procedures of positron emission tomography are described and the necessary apparatus considered, with emphasis on the positron camera. The first clinical applications using 55 Co bloemycine for tumor detection are presented. (C.F.)

Positron emission tomography of the heart

International Nuclear Information System (INIS)

Schelbert, H.R.; Phelps, M.E.; Kuhl, D.E.

1979-01-01

Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease

Positron emission tomography of the heart

Energy Technology Data Exchange (ETDEWEB)

Schelbert, H.R.; Phelps, M.E.; Kuhl, D.E.

1979-01-01

Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease.

18F-fluorodeoxyglucose positron emission tomography predicts survival of patients with neuroendocrine tumors

DEFF Research Database (Denmark)

Binderup, Tina; Knigge, Ulrich; Loft, Annika

2010-01-01

PURPOSE: (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) is currently not used on a routine basis for imaging of neuroendocrine (NE) tumors. The aim of this study was to investigate the prognostic value of FDG-PET in patients with NE tumors. EXPERIMENTAL DESIGN: Ninety...

Imaging spectrum and pitfalls of {sup 11}C-methionine position emission tomography in a series of patients with intracranial lesions

Energy Technology Data Exchange (ETDEWEB)

Ito, Kimiteru [Dept. of Radiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo (Japan); Matsuda, Hiroshi [Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, Tokyo (Japan); Kubota, Kazoo [Div. of Nuclear Medicine, National Center for Global Health and Medicine, Tokyo (Japan)

2016-06-15

{sup 11}C-methionine (Met) positron emission tomography (PET) is one of the most commonly used PET tracers for evaluating brain tumors. However, few reports have described tips and pitfalls of {sup 11}C-Met PET for general practitioners. Physiological {sup 11}C-Met uptake, anatomical variations, vascular disorders, non-tumorous lesions such as inflammation or dysplasia, benign brain tumors and patient condition during {sup 11}C-Met PET examination can potentially affect the image interpretation and cause false positives and negatives. These pitfalls in the interpretation of {sup 11}C-Met PET images are important for not only nuclear medicine physicians but also general radiologists. Familiarity with the spectrum and pitfalls of {sup 11}C-Met images could help prevent unfavorable clinical results caused by misdiagnoses.

Imaging TCR-Dependent NFAT-Mediated T-Cell Activation with Positron Emission Tomography In Vivo

Directory of Open Access Journals (Sweden)

Vladimir Ponomarev

2001-01-01

Full Text Available A noninvasive method for molecular imaging of T-cell activity in vivo would be of considerable value. It would aid in understanding the role of specific genes and signal transduction pathways in the course of normal and pathologic immune responses, could elucidate temporal dynamics and immune regulation at different stages of disease and following therapy. We developed and assessed a novel method for monitoring the T-cell receptor (TCR -dependent nuclear factor of activated T cells (NFAT -mediated activation of T cells by optical fluorescence imaging (OFI and positron emission tomography (PET. The herpes simplex virus type 1 thymidine kinase/green fluorescent protein [HSV1-tk/GFP (TKGFP ] dual reporter gene was used to monitor NFAT-mediated transcriptional activation in human Jurkat cells. A recombinant retrovirus bearing the NFAT-TKGFP reporter system was constructed in which the TKGFP reporter gene was placed under control of an artificial cis-acting NFAT-specific enhancer. Transduced Jurkat cells were used to establish subcutaneous infiltrates in nude rats. We demonstrated that noninvasive OR and nuclear imaging of T-cell activation is feasible using the NFAT-TKGFP reporter system. PET imaging with [124]FIAU using the NFAT-TKGFP reporter system is sufficiently sensitive to detect T-cell activation in vivo. PET images were confirmed by independent measurements of T-cell activation (e.g., CD69 and induction of GFP fluorescence. PET imaging of TCR-induced NFAT-dependent transcriptional activity may be useful in the assessment of T cell responses, T-cell-based adoptive therapies, vaccination strategies and immunosuppressive drugs.

[(18) F]fluoromethylcholine (FCH) positron emission tomography/computed tomography (PET/CT) for lymph node staging of prostate cancer

DEFF Research Database (Denmark)

Poulsen, Mads H; Bouchelouche, Kirsten; Høilund-Carlsen, Poul F

2012-01-01

recurrence. Therefore, one may question whether surgical lymph node dissection (LND) is sufficiently reliable for staging of these patients. Several imaging methods for primary LN staging of patients with prostate cancer have been tested. Acceptable detection rates have not been achieved by CT or MRI...... this procedure. However, we did detect several bone metastases with [(18) F]FCH PET/CT that the normal bone scans had missed, and this might be worth pursuing. OBJECTIVES: •  To assess the value of [(18) F]fluoromethylcholine (FCH) positron emission tomography/computed tomography (PET/CT) for lymph node (LN...

F-18 fluoride positron emission tomography/computed tomography in the diagnosis of avascular necrosis of the femoral head: Comparison with magnetic resonance imaging

Science.gov (United States)

Gayana, Shankaramurthy; Bhattacharya, Anish; Sen, Ramesh Kumar; Singh, Paramjeet; Prakash, Mahesh; Mittal, Bhagwant Rai

2016-01-01

Objective: Femoral head avascular necrosis (FHAVN) is one of the increasingly common causes of musculoskeletal disability and poses a major diagnostic and therapeutic challenge. Although radiography, scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI) have been widely used in the diagnosis of FHAVN, positron emission tomography (PET) has recently been evaluated to assess vascularity of the femoral head. In this study, the authors compared F-18 fluoride PET/CT with MRI in the initial diagnosis of FHAVN. Patients and Methods: We prospectively studied 51 consecutive patients with a high clinical suspicion of FHAVN. All patients underwent MRI and F-18 fluoride PET/CT, the time interval between the two scans being 4–10 (mean 8) days. Two nuclear medicine physicians blinded to the MRI report read the PET/CT scans. Clinical assessment was also done. Final diagnoses were made by surgical pathology or clinical and radiologic follow-up. Results: A final diagnosis of avascular necrosis (AVN) was made in 40 patients. MRI was 96.5% sensitive, 100% specific, and 98.03% accurate while PET/CT was 100% sensitive, specific, and accurate in diagnosing FHAVN. The agreement between the two imaging modalities for the diagnosis of AVN was 96.07%. Conclusion: F-18 fluoride PET/CT showed good agreement with MRI in the initial diagnosis of FHAVN and can be better than MRI in detecting early disease. PMID:26917886

F-18 fluoride positron emission tomography/computed tomography in the diagnosis of avascular necrosis of the femoral head: Comparison with magnetic resonance imaging

International Nuclear Information System (INIS)

Gayana, Shankaramurthy; Bhattacharya, Anish; Sen, Ramesh Kumar; Singh, Paramjeet; Prakash, Mahesh; Mittal, Bhagwant Rai

2016-01-01

Femoral head avascular necrosis (FHAVN) is one of the increasingly common causes of musculoskeletal disability and poses a major diagnostic and therapeutic challenge. Although radiography, scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI) have been widely used in the diagnosis of FHAVN, positron emission tomography (PET) has recently been evaluated to assess vascularity of the femoral head. In this study, the authors compared F-18 fluoride PET/CT with MRI in the initial diagnosis of FHAVN. We prospectively studied 51 consecutive patients with a high clinical suspicion of FHAVN. All patients underwent MRI and F-18 fluoride PET/CT, the time interval between the two scans being 4–10 (mean 8) days. Two nuclear medicine physicians blinded to the MRI report read the PET/CT scans. Clinical assessment was also done. Final diagnoses were made by surgical pathology or clinical and radiologic follow-up. A final diagnosis of avascular necrosis (AVN) was made in 40 patients. MRI was 96.5% sensitive, 100% specific, and 98.03% accurate while PET/CT was 100% sensitive, specific, and accurate in diagnosing FHAVN. The agreement between the two imaging modalities for the diagnosis of AVN was 96.07%. F-18 fluoride PET/CT showed good agreement with MRI in the initial diagnosis of FHAVN and can be better than MRI in detecting early disease

Single photon emission computed tomography in AIDS dementia complex

International Nuclear Information System (INIS)

Pohl, P.; Vogl, G.; Fill, H.; Roessler, H.Z.; Zangerle, R.; Gerstenbrand, F.

1988-01-01

Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder

Positron emission tomography imaging of CD105 expression during tumor angiogenesis

Energy Technology Data Exchange (ETDEWEB)

Hong, Hao [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Yang, Yunan [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Third Military Medical University, Department of Ultrasound, Xinqiao Hospital, Chongqing (China); Zhang, Yin; Engle, Jonathan W.; Barnhart, Todd E.; Nickles, Robert J. [University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); Leigh, Bryan R. [TRACON Pharmaceuticals, Inc., San Diego, CA (United States); Cai, Weibo [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin Carbone Cancer Center, Madison, WI (United States); University of Wisconsin - Madison, Departments of Radiology and Medical Physics, School of Medicine and Public Health, Madison, WI (United States)

2011-07-15

Overexpression of CD105 (endoglin) correlates with poor prognosis in many solid tumor types. Tumor microvessel density (MVD) assessed by CD105 staining is the current gold standard for evaluating tumor angiogenesis in the clinic. The goal of this study was to develop a positron emission tomography (PET) tracer for imaging CD105 expression. TRC105, a chimeric anti-CD105 monoclonal antibody, was conjugated to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and labeled with {sup 64}Cu. FACS analysis and microscopy studies were performed to compare the CD105 binding affinity of TRC105 and DOTA-TRC105. PET imaging, biodistribution, blocking, and ex vivo histology studies were performed on 4T1 murine breast tumor-bearing mice to evaluate the ability of {sup 64}Cu-DOTA-TRC105 to target tumor angiogenesis. Another chimeric antibody, cetuximab, was used as an isotype-matched control. FACS analysis of human umbilical vein endothelial cells (HUVECs) revealed no difference in CD105 binding affinity between TRC105 and DOTA-TRC105, which was further validated by fluorescence microscopy. {sup 64}Cu labeling was achieved with high yield and specific activity. Serial PET imaging revealed that the 4T1 tumor uptake of the tracer was 8.0 {+-} 0.5, 10.4 {+-} 2.8, and 9.7 {+-} 1.8%ID/g at 4, 24, and 48 h post-injection, respectively (n = 3), higher than most organs at late time points which provided excellent tumor contrast. Biodistribution data as measured by gamma counting were consistent with the PET findings. Blocking experiments, control studies with {sup 64}Cu-DOTA-cetuximab, as well as ex vivo histology all confirmed the in vivo target specificity of {sup 64}Cu-DOTA-TRC105. This is the first successful PET imaging study of CD105 expression. Fast, prominent, persistent, and CD105-specific uptake of the tracer in the 4T1 tumor was observed. Further studies are warranted and currently underway. (orig.)

MRI and {sup 18}F-fluorodeoxyglucose positron emission tomography in hemimegalencephaly

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, K.T.; Liebig, T.; Hosten, N. [Departments of Radiology and Nuclear Medicine, Virchow-Klinikum, Charite, Berlin (Germany); Amthauer, H.; Farahati, J.; Felix, R. [Departments of Radiology and Nuclear Medicine, Virchow-Klinikum, Charite, Berlin (Germany); PET-Centre Berlin, Virchow-Klinikum, Charite, Humboldt-University, Berlin (Germany); Etou, A.; Lehmann, T.N. [Department of Neurosurgery, Virchow-Klinikum, Charite, Humboldt-University, Berlin (Germany)

2000-10-01

We report hemimegalencephaly in a 44-year-old woman with mental retardation, epilepsy and a mild hemiparesis. In addition to typical findings on MRI, 2-deoxy-2[{sup 18}F]fluorodeoxyglucose positron-emission tomography (PET) demonstrated glucose hypometabolism of the affected hemisphere. The results of PET have been coregistered with morphological information from the MRI studies by image fusion. (orig.)

Importance of Defect Detectability in Positron Emission Tomography Imaging of Abdominal Lesions

International Nuclear Information System (INIS)

Yamashita, Shozo; Yokoyama, Kunihiko; Onoguchi, Masahisa; Yamamoto, Haruki; Nakaichi, Tetsu; Tsuji, Shiro; Nakajima, Kenichi

2015-01-01

This study was designed to assess defect detectability in positron emission tomography (PET) imaging of abdominal lesions. A National Electrical Manufactures Association International Electrotechnical Commission phantom was used. The simulated abdominal lesion was scanned for 10 min using dynamic list-mode acquisition method. Images, acquired with scan duration of 1-10 min, were reconstructed using VUE point HD and a 4.7 mm full-width at half-maximum (FWHM) Gaussian filter. Iteration-subset combinations of 2-16 and 2-32 were used. Visual and physical analyses were performed using the acquired images. To sequentially evaluate defect detectability in clinical settings, we examined two middle-aged male subjects. One had a liver cyst (approximately 10 mm in diameter) and the other suffered from pancreatic cancer with an inner defect region (approximately 9 mm in diameter). In the phantom study, at least 6 and 3 min acquisition durations were required to visualize 10 and 13 mm defect spheres, respectively. On the other hand, spheres with diameters ≥17 mm could be detected even if the acquisition duration was only 1 min. The visual scores were significantly correlated with background (BG) variability. In clinical settings, the liver cyst could be slightly visualized with an acquisition duration of 6 min, although image quality was suboptimal. For pancreatic cancer, the acquisition duration of 3 min was insufficient to clearly describe the defect region. The improvement of BG variability is the most important factor for enhancing lesion detection. Our clinical scan duration (3 min/bed) may not be suitable for the detection of small lesions or accurate tumor delineation since an acquisition duration of at least 6 min is required to visualize 10 mm lesions, regardless of reconstruction parameters. Improvements in defect detectability are important for radiation treatment planning and accurate PET-based diagnosis

Comparison of five segmentation tools for 18F-fluoro-deoxy-glucose-positron emission tomography-based target volume definition in head and neck cancer.

NARCIS (Netherlands)

Schinagl, D.A.X.; Vogel, W.V.; Hoffmann, A.L.; Dalen, J.A. van; Oyen, W.J.G.; Kaanders, J.H.A.M.

2007-01-01

PURPOSE: Target-volume delineation for radiation treatment to the head and neck area traditionally is based on physical examination, computed tomography (CT), and magnetic resonance imaging. Additional molecular imaging with (18)F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) may

Fluorine-18-fluorodeoxyglucose Positron Emission Tomography in Diffuse Large B-cell Lymphoma

DEFF Research Database (Denmark)

Mylam, Karen Juul; Nielsen, Anne Lerberg; Pedersen, Lars Møller

2014-01-01

Diffuse large B-cell lymphoma (DLBCL) is an aggressive and potentially curable type of lymphoma. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) is part of clinical routine for DLBCL in most hospitals and also recommended for staging and end-of-therapy evaluation. FDG......-PET/computed tomography (CT) is able to identify nodal and extranodal sites with greater accuracy than CT alone. Little evidence supports the use of surveillance FDG-PET imaging in the follow-up setting because of high rates of false-positive scans and because most studies are retrospective. This article discusses FDG...

Basic principles of 18F-fluoro-deoxyglucose positron emission tomography

International Nuclear Information System (INIS)

Standke, R.

2002-01-01

Positron emission tomography uses photons to receive regional information about dynamic, physiologic, and biochemical processes in the living body. A positron decay is measured indirectly by the simultaneous registration of both gamma rays created by the annihilation. The event is counted, if two directly opposite located detectors register gamma rays in coincidence. Unfortunately the detectors of a positron emission tomography system do not register only true coincident events. There are also scattered and random coincidences. Different types of positron tomographs are presented and scintillation crystals, which are in use for positron emission tomography are discussed. The 2D- and 3D-acquisition methods are described as well as preprocessing methods, such as correction for attenuation, scatter and dead time. For quantification the relative parameter standard uptake value (SUV) is explained. Finally hybrid systems, such as combined positron emission tomography/computed tomography scanners and the use of computed tomography data for attenuation correction are introduced. (author)

Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

Science.gov (United States)

Gewirtz, Henry; Dilsizian, Vasken

2016-05-31

In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted. © 2016 American Heart Association, Inc.

Positron emission tomography of the lung

International Nuclear Information System (INIS)

Wollmer, P.

1984-01-01

Positron emission tomography enables the distribution of positron emitting isotopes to be imaged in a transverse plane through the body and the regional concentration of the isotope to be measured quantitatively. This thesis reports some applications of positron emission tomography to studies of pulmonary pathophysiology. Measurements in lung phantoms showed that regional lung density could be measured from a transmission tomogram obtained with an external source of positron emitting isotope. The regional, fractional blood volume was measured after labelling the blood with carbon-11-monoxide. Regional extravascular lung density (lung tissue and interstitial water per unit thoracic volume) was obtained by subtracting fractional blood volume from lung density. Measurements in normal subjects revealed large regional variations in lung density and fractional blood volume in the supine posture. Extravascular lung density showed a more uniform distribution. The technique has been used to study patients with chronic interstitial pulmonary oedema, pulmonary sarcoidosis and fibrosis, pulmonary arterial hypertension and patients with intracardiac, left-to-right shunt. Tomographic measurements of pulmonary tissue concentration of radionuclides are difficult, since corrections for the blood content and the inflation of the lung must be applied. A simultaneous measurement of lung density and fractional blood volume allows such corrections to be made and the extravascular tracer concentration to be calculated. This has been applied to measurements of the tissue penetration of carbon-11-labelled erythromycin in patients with lobar pneumonia. (author)

(18)F-fluoride positron emission tomography/computed tomography and bone scintigraphy for diagnosis of bone metastases in newly diagnosed, high-risk prostate cancer patients: study protocol for a multicentre, diagnostic test accuracy study.

Science.gov (United States)

Fonager, Randi F; Zacho, Helle D; Langkilde, Niels C; Petersen, Lars J

2016-01-11

For decades, planar bone scintigraphy has been the standard practice for detection of bone metastases in prostate cancer and has been endorsed by recent oncology/urology guidelines. It is a sensitive method with modest specificity. (18)F-fluoride positron emission tomography/computed tomography has shown improved sensitivity and specificity over bone scintigraphy, but because of methodological issues such as retrospective design and verification bias, the existing level of evidence with (18)F-fluoride positron emission tomography/computed tomography is limited. The primary objective is to compare the diagnostic properties of (18)F-fluoride positron emission tomography/computed tomography versus bone scintigraphy on an individual patient basis. One hundred forty consecutive, high-risk prostate cancer patients will be recruited from several hospitals in Denmark. Sample size was calculated using Hayen's method for diagnostic comparative studies. This study will be conducted in accordance with recommendations of standards for reporting diagnostic accuracy studies. Eligibility criteria comprise the following: 1) biopsy-proven prostate cancer, 2) PSA ≥ 50 ng/ml (equals a prevalence of bone metastasis of ≈ 50% in the study population on bone scintigraphy), 3) patients must be eligible for androgen deprivation therapy, 4) no current or prior cancer (within the past 5 years), 5) ability to comply with imaging procedures, and 6) patients must not receive any investigational drugs. Planar bone scintigraphy and (18)F-fluoride positron emission tomography/computed tomography will be performed within a window of 14 days at baseline. All scans will be repeated after 26 weeks of androgen deprivation therapy, and response of individual lesions will be used for diagnostic classification of the lesions on baseline imaging among responding patients. A response is defined as PSA normalisation or ≥ 80% reduction compared with baseline levels, testosterone below castration levels

Neutron stimulated emission computed tomography: Background corrections

International Nuclear Information System (INIS)

Floyd, Carey E.; Sharma, Amy C.; Bender, Janelle E.; Kapadia, Anuj J.; Xia, Jessie Q.; Harrawood, Brian P.; Tourassi, Georgia D.; Lo, Joseph Y.; Kiser, Matthew R.; Crowell, Alexander S.; Pedroni, Ronald S.; Macri, Robert A.; Tajima, Shigeyuki; Howell, Calvin R.

2007-01-01

Neutron stimulated emission computed tomography (NSECT) is an imaging technique that provides an in-vivo tomographic spectroscopic image of the distribution of elements in a body. To achieve this, a neutron beam illuminates the body. Nuclei in the body along the path of the beam are stimulated by inelastic scattering of the neutrons in the beam and emit characteristic gamma photons whose unique energy identifies the element. The emitted gammas are collected in a spectrometer and form a projection intensity for each spectral line at the projection orientation of the neutron beam. Rotating and translating either the body or the beam will allow a tomographic projection set to be acquired. Images are reconstructed to represent the spatial distribution of elements in the body. Critical to this process is the appropriate removal of background gamma events from the spectrum. Here we demonstrate the equivalence of two background correction techniques and discuss the appropriate application of each

Emission computed tomography with technetium-99m pyrophosphate for delineating location and size of acute myocardial infarction in man

Energy Technology Data Exchange (ETDEWEB)

Tamaki, S; Kadota, K; Kambara, H; Suzuki, Y; Nohara, R; Murakami, T; Kawai, C; Tamaki, N; Torizuka, K [Kyoto Univ. (Japan). Faculty of Medicine

1984-07-01

Emission computed tomography with technetium-99m pyrophosphate was used to delineate the location and estimate the size of myocardial infarcts in 20 patients with documented acute myocardial infarction. Tomography was performed after planar imaging within 2-5 days after the onset of infarction. Infarct volume was measured from the tomographic images by computerised planimetry and compared with the cumulative release of creatine kinase MB isoenzyme. The planar images showed discrete myocardial uptake in 13 of the 20 patients and diffuse uptake throughout the cardiac region in the remaining seven. In contrast, the tomographic images clearly delineated myocardial uptake by avoiding confusion of myocardial activity with that of surrounding structures, particularly bones, in all patients. For the 10 patients whose infarct size was assessed by analysis of the creatine kinase MB curve there was a close correlation between infarct volume estimated by tomography and by cumulative creatine kinase MB release. Thus emission computed tomography can provide a three dimensional map of technetium-99m pyrophosphate distribution within the heart and is thus able accurately to localise and estimate the size of myocardial infarcts in man.

Emission computed tomography with technetium-99m pyrophosphate for delineating location and size of acute myocardial infarction in man

International Nuclear Information System (INIS)

Tamaki, S.; Kadota, K.; Kambara, H.; Suzuki, Y.; Nohara, R.; Murakami, T.; Kawai, C.; Tamaki, N.; Torizuka, K.

1984-01-01

Emission computed tomography with technetium-99m pyrophosphate was used to delineate the location and estimate the size of myocardial infarcts in 20 patients with documented acute myocardial infarction. Tomography was performed after planar imaging within 2-5 days after the onset of infarction. Infarct volume was measured from the tomographic images by computerised planimetry and compared with the cumulative release of creatine kinase MB isoenzyme. The planar images showed discrete myocardial uptake in 13 of the 20 patients and diffuse uptake throughout the cardiac region in the remaining seven. In contrast, the tomographic images clearly delineated myocardial uptake by avoiding confusion of myocardial activity with that of surrounding structures, particularly bones, in all patients. For the 10 patients whose infarct size was assessed by analysis of the creatine kinase MB curve there was a close correlation between infarct volume estimated by tomography and by cumulative creatine kinase MB release. Thus emission computed tomography can provide a three dimensional map of technetium-99m pyrophosphate distribution within the heart and is thus able accurately to localise and estimate the size of myocardial infarcts in man. (author)

Positron emission tomography for the assessment of myocardial viability

International Nuclear Information System (INIS)

Schelbert, H.R.

1991-01-01

The detection of viable myocardium or ischemically injured myocardium with a reversible impairment of contractile function remains clinically important but challenging. Detection of reversible dysfunction and distinction from irreversible tissue injury by positron emission tomography is based on identification of preserved or even enhanced glucose metabolism with F-18 2-fluoro 2-deoxyglucose. Regional patterns of myocardial glucose utilization and blood flow, defined as perfusion-metabolism mismatches or matches, on positron emission tomography in patients with chronic or even acute ischemic heart disease are highly accurate in predicting the functional outcome after interventional revascularization. Compared with thallium-201 redistribution scintigraphy, positron emission tomography appears to be diagnostically more accurate, especially in patients with severely impaired left ventricular function. While larger clinical trials are needed for further confirmation, positron emission tomography has already proved clinically useful for stratifying patients with poor left ventricular function to the most appropriate therapeutic approach

F-18-fluorodeoxyglucose-positron-emission tomography in neurology

International Nuclear Information System (INIS)

Fazekas, F.; Payer, F.

2002-01-01

Positron emission tomography using F-18-fluorodeoxyglucose (F-18-FDG-PET) is an ideal tool for imaging regional cerebral metabolism as glucose is the most important source of energy for neurons. Under physiologic conditions the pattern of metabolism reflects the state of cerebral activation which can be modulated by various stimuli to investigate cerebral organization. Pathologic conditions usually cause a drop in metabolism because of neuronal inactivity or loss. They can, however, also be associated with an increased rate of glucose metabolism such as in case of active epileptic foci or malignant tumors. As a consequence F-18-FDG-PET has become a valuable functional imaging modality especially for the diagnostic clarification of non-contributory or negative morphologic imaging results. Dementia, pre-surgical evaluation of epilepsy and neurooncology are currently frequent indications for referral to F-18-FDG-PET in neurology. (author)

Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

DEFF Research Database (Denmark)

Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

Background: Positron emission tomography (PET) imaging of anaesthetised pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the kinetics of several radiotracers. However, the impact of physiological factors regulating CBF...

Characterization of positron emission tomography hypoxia tracer uptake and tissue oxygenation via electrochemical modeling

NARCIS (Netherlands)

Bowen, S.R.; Kogel, A.J. van der; Nordsmark, M.; Bentzen, S.M.; Jeraj, R.

2011-01-01

PURPOSE: Unique uptake and retention mechanisms of positron emission tomography (PET) hypoxia tracers make in vivo comparison between them challenging. Differences in imaged uptake of two common hypoxia radiotracers, [(61)Cu]Cu-ATSM and [(18)F]FMISO, were characterized via computational modeling to

A heuristic statistical stopping rule for iterative reconstruction in emission tomography

International Nuclear Information System (INIS)

Ben Bouallegue, F.; Mariano-Goulart, D.; Crouzet, J.F.

2013-01-01

We propose a statistical stopping criterion for iterative reconstruction in emission tomography based on a heuristic statistical description of the reconstruction process. The method was assessed for maximum likelihood expectation maximization (MLEM) reconstruction. Based on Monte-Carlo numerical simulations and using a perfectly modeled system matrix, our method was compared with classical iterative reconstruction followed by low-pass filtering in terms of Euclidian distance to the exact object, noise, and resolution. The stopping criterion was then evaluated with realistic PET data of a Hoffman brain phantom produced using the Geant4 application in emission tomography (GATE) platform for different count levels. The numerical experiments showed that compared with the classical method, our technique yielded significant improvement of the noise-resolution tradeoff for a wide range of counting statistics compatible with routine clinical settings. When working with realistic data, the stopping rule allowed a qualitatively and quantitatively efficient determination of the optimal image. Our method appears to give a reliable estimation of the optimal stopping point for iterative reconstruction. It should thus be of practical interest as it produces images with similar or better quality than classical post-filtered iterative reconstruction with a mastered computation time. (author)

Positron emission tomography

International Nuclear Information System (INIS)

Marchenkov, N.S.

2000-01-01

The foundations of the positron emission tomography (PET), widely used for the medical diagnostics, are considered. The brief description of the cyclotron for production of radionuclides, applied in the PET, the target devices for manufacturing the position emitters, the moduli for the radiopharmaceuticals synthesis (RPS) for the PET is presented. The necessity and concept of complete automation of the RPS for the PET are discussed [ru

Monoamine oxidase B single-photon emission tomography with [123I]Ro 43-0463: imaging in volunteers and patients with temporal lobe epilepsy

International Nuclear Information System (INIS)

Buck, A.; Frey, L.D.; Blaeuenstein, P.; Schubiger, P.; Kraemer, G.; Siegel, A.; Weber, B.; Wieser, H.G.

1998-01-01

Imaging of monoamine oxidase of subtype B (MAO B) is of interest in various neurological diseases. In the past non-invasive assessment of MAO B has only been possible with positron emission tomography (PET) ligands. Given the limited availability of PET, a single-photon emission tomography (SPET) ligand would be desirable. In this study SPET imaging with the new MAO B inhibitor [ 123 I]Ro 43-0463 was performed in five volunteers and nine patients with temporal lobe epilepsy (TLE). In two volunteers a second study was performed 12 h following blockade with deprenyl. In the TLE patients the tracer was administered as bolus (n = 4) or as prolonged infusion (n = 5). The regional uptake pattern correlated well with the known distribution of MAO B. In the two blocking studies ligand uptake was substantially reduced compared with baseline. In the TLE patients increased uptake was found in the ipsilateral mesial temporal lobe and, surprisingly, in the ipsilateral putamen. This study indicates the potential of the new SPET ligand [ 123 I]Ro 43-0463 to map MAO B concentration in the human brain. The new finding of increased MAO B in the putamen of TLE patients needs further studies to elucidate its exact pathophysiology. (orig.)

Geometrical differences in target volumes based on 18F-fluorodeoxyglucose positron emission tomography/computed tomography and four-dimensional computed tomography maximum intensity projection images of primary thoracic esophageal cancer.

Science.gov (United States)

Guo, Y; Li, J; Wang, W; Zhang, Y; Wang, J; Duan, Y; Shang, D; Fu, Z

2014-01-01

The objective of the study was to compare geometrical differences of target volumes based on four-dimensional computed tomography (4DCT) maximum intensity projection (MIP) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) images of primary thoracic esophageal cancer for radiation treatment. Twenty-one patients with thoracic esophageal cancer sequentially underwent contrast-enhanced three-dimensional computed tomography (3DCT), 4DCT, and 18F-FDG PET/CT thoracic simulation scans during normal free breathing. The internal gross target volume defined as IGTVMIP was obtained by contouring on MIP images. The gross target volumes based on PET/CT images (GTVPET ) were determined with nine different standardized uptake value (SUV) thresholds and manual contouring: SUV≥2.0, 2.5, 3.0, 3.5 (SUVn); ≥20%, 25%, 30%, 35%, 40% of the maximum (percentages of SUVmax, SUVn%). The differences in volume ratio (VR), conformity index (CI), and degree of inclusion (DI) between IGTVMIP and GTVPET were investigated. The mean centroid distance between GTVPET and IGTVMIP ranged from 4.98 mm to 6.53 mm. The VR ranged from 0.37 to 1.34, being significantly (P<0.05) closest to 1 at SUV2.5 (0.94), SUV20% (1.07), or manual contouring (1.10). The mean CI ranged from 0.34 to 0.58, being significantly closest to 1 (P<0.05) at SUV2.0 (0.55), SUV2.5 (0.56), SUV20% (0.56), SUV25% (0.53), or manual contouring (0.58). The mean DI of GTVPET in IGTVMIP ranged from 0.61 to 0.91, and the mean DI of IGTVMIP in GTVPET ranged from 0.34 to 0.86. The SUV threshold setting of SUV2.5, SUV20% or manual contouring yields the best tumor VR and CI with internal-gross target volume contoured on MIP of 4DCT dataset, but 3DPET/CT and 4DCT MIP could not replace each other for motion encompassing target volume delineation for radiation treatment. © 2014 International Society for Diseases of the Esophagus.

Fluorodeoxyglucose-based positron emission tomography imaging to monitor drug responses in hematological tumors

NARCIS (Netherlands)

Newbold, Andrea; Martin, Ben P.; Cullinane, Carleen; Bots, Michael

2014-01-01

Positron emission tomography (PET) can be used to monitor the uptake of the labeled glucose analog fluorodeoxyglucose (¹⁸F-FDG), a process that is generally believed to reflect viable tumor cell mass. The use of ¹⁸F-FDG PET can be helpful in documenting over time the reduction in tumor mass volume

Detector response restoration in image reconstruction of high resolution positron emission tomography

International Nuclear Information System (INIS)

Liang, Z.

1994-01-01

A mathematical method was studied to model the detector response of high spatial-resolution positron emission tomography systems consisting of close-packed small crystals, and to restore the resolution deteriorated due to crystal penetration and/or nonuniform sampling across the field-of-view (FOV). The simulated detector system had 600 bismuth germanate crystals of 3.14 mm width and 30 mm length packed on a single ring of 60 cm diameter. The space between crystal was filled up with lead. Each crystal was in coincidence with 200 opposite crystals so that the FOV had a radius of 30 cm. The detector response was modeled based on the attenuating properties of the crystals and the septa, as well as the geometry of the detector system. The modeled detector-response function was used to restore the projections from the sinogram of the ring-detector system. The restored projections had a uniform sampling of 1.57 mm across the FOV. The crystal penetration and/or the nonuniform sampling were compensated in the projections. A penalized maximum-likelihood algorithm was employed to accomplish the restoration. The restored projections were then filtered and backprojected to reconstruct the image. A chest phantom with a few small circular ''cold'' objects located at the center and near the periphery of FOV was computer generated and used to test the restoration. The reconstructed images from the restored projections demonstrated resolution improvement off the FOV center, while preserving the resolution near the center

The Positron Emission Tomography. A diagnostic technique

International Nuclear Information System (INIS)

Salvadori, P.

2001-01-01

Positron Emission Tomography (PET) is a new imaging modality, which is able to assess non-invasively the biochemical mechanisms, underlying physiological and pathophysiological processes in vivo in humans. The technique relies on the administration of radioactive tracers labeled with short-lived positron emitters, which need to be produced on site via a particle accelerator (cyclotron). Radionuclides are produced upon request and formulated into biologically active organic molecules having precise pharmacokinetics and specificity. The radiotracer can be detected by the PET scanner and represented as tomographic sections (images of body sections) showing its regional distribution and concentration. This makes it possible to address clinical questions concerning occurrence and evolution of many diseases as well as their response to therapy. The ability to image (measure) biological processes and not only anatomy enables PET to explore diseases in the very early stage, including those diseases which are not related to modifications of organ structure (e.g. psychiatric diseases, metabolic disorders, biochemical disfunction). PET plays a major role, in conjunction with the other imaging modalities, to improve diagnosis capabilities and disease mechanism understanding [it

Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Disseminated Cryptococcosis.

Science.gov (United States)

Tripathy, Sarthak; Parida, Girish Kumar; Roy, Shambo Guha; Singhal, Abhinav; Mallick, Saumya Ranjan; Tripathi, Madhavi; Shamim, Shamim Ahmed

2017-01-01

Disseminated cryptococcosis without pulmonary involvement is a very rare phenomenon. Patterns of organ involvement in cryptococcosis resemble various other infective conditions as well as malignant conditions on fluorodeoxyglucose positron emission tomography-computed tomography. We present a case of a 43-year-old male patient who had disseminated cryptococcosis. The rarity of the case being noninvolvement of lungs and meninges and resembling more like lymphoma due to the diffuse involvement of the lymph nodes on both sides of the diaphragm.

Molecular Imaging of Transporters with Positron Emission Tomography

Science.gov (United States)

Antoni, Gunnar; Sörensen, Jens; Hall, Håkan

Positron emission tomography (PET) visualization of brain components in vivo is a rapidly growing field. Molecular imaging with PET is also increasingly used in drug development, especially for the determination of drug receptor interaction for CNS-active drugs. This gives the opportunity to relate clinical efficacy to per cent receptor occupancy of a drug on a certain targeted receptor and to relate drug pharmacokinetics in plasma to interaction with target protein. In the present review we will focus on the study of transporters, such as the monoamine transporters, the P-glycoprotein (Pgp) transporter, the vesicular monoamine transporter type 2, and the glucose transporter using PET radioligands. Neurotransmitter transporters are presynaptically located and in vivo imaging using PET can therefore be used for the determination of the density of afferent neurons. Several promising PET ligands for the noradrenaline transporter (NET) have been labeled and evaluated in vivo including in man, but a really useful PET ligand for NET still remains to be identified. The most promising tracer to date is (S,S)-[18F]FMeNER-D2. The in vivo visualization of the dopamine transporter (DAT) may give clues in the evaluation of conditions related to dopamine, such as Parkinson's disease and drug abuse. The first PET radioligands based on cocaine were not selective, but more recently several selective tracers such as [11C]PE2I have been characterized and shown to be suitable as PET radioligands. Although there are a large number of serotonin transporter inhibitors used today as SSRIs, it was not until very recently, when [11C]McN5652 was synthesized, that this transporter was studied using PET. New candidates as PET radioligands for the SERT have subsequently been developed and [11C]DASB and [11C]MADAM and their analogues are today the most promising ligands. The existing radioligands for Pgp transporters seem to be suitable tools for the study of both peripheral and central drug

Software development for dynamic position emission tomography: Dynamic image analysis (DIA) tool

Energy Technology Data Exchange (ETDEWEB)

Pyeon, Do Yeong; Jung, Young Jin [Dongseo University, Busan (Korea, Republic of); Kim, Jung Su [Dept. of Radilogical Science, Dongnam Health University, Suwon (Korea, Republic of)

2016-09-15

Positron Emission Tomography(PET) is nuclear medical tests which is a combination of several compounds with a radioactive isotope that can be injected into body to quantitatively measure the metabolic rate (in the body). Especially, Phenomena that increase (sing) glucose metabolism in cancer tissue using the 18F-FDG (Fluorodeoxyglucose) is utilized widely in cancer diagnosis. And then, Numerous studies have been reported that incidence seems high availability even in the modern diagnosis of dementia and Parkinson's (disease) in brain disease. When using a dynamic PET image including the time information in the static information that is provided for the diagnosis many can increase the accuracy of diagnosis. For this reason, clinical researchers getting great attention but, it is the lack of tools to conduct research. And, it interfered complex mathematical algorithm and programming skills for activation of research. In this study, in order to easy to use and enable research dPET, we developed the software based graphic user interface(GUI). In the future, by many clinical researcher using DIA-Tool is expected to be of great help to dPET research.

Software development for dynamic position emission tomography: Dynamic image analysis (DIA) tool

International Nuclear Information System (INIS)

Pyeon, Do Yeong; Jung, Young Jin; Kim, Jung Su

2016-01-01

Positron Emission Tomography(PET) is nuclear medical tests which is a combination of several compounds with a radioactive isotope that can be injected into body to quantitatively measure the metabolic rate (in the body). Especially, Phenomena that increase (sing) glucose metabolism in cancer tissue using the 18F-FDG (Fluorodeoxyglucose) is utilized widely in cancer diagnosis. And then, Numerous studies have been reported that incidence seems high availability even in the modern diagnosis of dementia and Parkinson's (disease) in brain disease. When using a dynamic PET image including the time information in the static information that is provided for the diagnosis many can increase the accuracy of diagnosis. For this reason, clinical researchers getting great attention but, it is the lack of tools to conduct research. And, it interfered complex mathematical algorithm and programming skills for activation of research. In this study, in order to easy to use and enable research dPET, we developed the software based graphic user interface(GUI). In the future, by many clinical researcher using DIA-Tool is expected to be of great help to dPET research

Positron emission tomography studies in the normal and abnormal ageing of human brain

International Nuclear Information System (INIS)

Comar, D.; Baron, J.C.

1987-01-01

Until recently, the investigation of the neurophysiological correlates of normal and abnormal ageing of the human brain was limited by methodological constraints, as the technics available provided only a few parameters (e.g. electroencephalograms, cerebral blood flow) monitored in superficial brain structures in a grossly regional and poorly quantitative way. Lately several non invasive techniques have been developed which allow to investigate in vivo both quantitatively and on local basis a number of previously inaccessible important aspects of brain function. Among these techniques, such as single photon emission tomography imaging of computerized electric events, nuclear magnetic resonance, positron emission tomography stands out as the most powerful and promising method since it allows the in vivo measurement of biochemical and pharmacological parameters

Evaluation of 4-[(18)F]fluorobenzoyl-FALGEA-NH(2) as a positron emission tomography tracer for epidermal growth factor receptor mutation variant III imaging in cancer

DEFF Research Database (Denmark)

Denholt, Charlotte Lund; Binderup, Tina; Stockhausen, Marie-Thérése

2011-01-01

This study describes the radiosynthesis, in vitro and in vivo evaluation of the novel small peptide radioligand, 4-[(18)F]fluorobenzoyl-Phe-Ala-Leu-Gly-Glu-Ala-NH(2,) ([(18)F]FBA-FALGEA-NH(2)) as a positron emission tomography (PET) tracer for imaging of the cancer specific epidermal growth facto...

Images of gravitational and magnetic phenomena derived from two-dimensional back-projection Doppler tomography of interacting binary stars

International Nuclear Information System (INIS)

Richards, Mercedes T.; Cocking, Alexander S.; Fisher, John G.; Conover, Marshall J.

2014-01-01

We have used two-dimensional back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries that undergo mass transfer from a magnetically active star onto a non-magnetic main-sequence star. This multitiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity images constructed from tomography, and the influence on the tomograms of orbital inclination, systemic velocity, orbital coverage, and shadowing. The Hα tomograms revealed eight sources: chromospheric emission, a gas stream along the gravitational trajectory, a star-stream impact region, a bulge of absorption or emission around the mass-gaining star, a Keplerian accretion disk, an absorption zone associated with hotter gas, a disk-stream impact region, and a hot spot where the stream strikes the edge of a disk. We described several methods used to extract the physical properties of the emission sources directly from the velocity images, including S-wave analysis, the creation of simulated velocity tomograms from hydrodynamic simulations, and the use of synthetic spectra with tomography to sequentially extract the separate sources of emission from the velocity image. In summary, the tomography images have revealed results that cannot be explained solely by gravitational effects: chromospheric emission moving with the mass-losing star, a gas stream deflected from the gravitational trajectory, and alternating behavior between stream state and disk state. Our results demonstrate that magnetic effects cannot be ignored in these interacting binaries.

Brain receptor single-photon emission computer tomography with 123I Datscan in Parkinson's disease

International Nuclear Information System (INIS)

Minchev, D.; Peshev, N.; Kostadinova, I.; Grigorova, O.; Trindev, P.; Shotekov, P.

2005-01-01

Clinical aspects of Parkinson's disease are not enough for the early diagnosis of the disease. Positron emission tomography and the receptor single - photon emission tomography can be used for imaging functional integrity of nigrostriatal dopaminergic structures. 24 patient (17 men and 7 women) were investigated. 20 of them are with Parkinson's disease and 4 are with essential tremor. The radiopharmaceutical - 123I-Datscan (ioflupane, bind with 123I) represent a cocaine analogue with selective affinity to dopamine transporters, located in the dopaminergic nigrostriatal terminals in the striatum. Single - photon emission computer tomography was performed with SPECT gamma camera (ADAC, SH Epic detector). The scintigraphic study was made 3 to 6 hours after intravenous injection of the radiopharmaceutical - 123I- Datscan in dose 185 MBq. 120 frames are registered with duration of each one 22 seconds and gamma camera rotation 360. After generation of transversal slices we generated two composites pictures. The first composite picture image the striatum, the second - the occipital region. Two ratios were calculated representing the uptake of the radiopharmaceutical in the left and right striatum. Qualitative and quantitative criteria were elaborated for evaluating the scintigraphic patterns. Decreased, nonhomogeneous and asymmetric uptake of the radiopharmaceutical coupled with low quantitative parameters in range from 1.44 to 2.87 represents the characteristic scintigraphic pattern for Parkinson's disease with clear clinical picture. Homogenous with high intensity and symmetric uptake of the radiopharmaceutical in the striatum coupled with his clear frontier and with quantitative parameters up to 4.40 represent the scintigraphic pattern in two patients with essential tremor. Receptor single - photon emission computer tomography with 123I - Datscan represents an accurate nuclear-medicine method for precise diagnosis of Parkinson's disease and for its differentiation from

Applications of multi-pinhole gamma camera collimation to tomography and image enhancement

Science.gov (United States)

Simpson, D. R.

1981-06-01

Multi-pinhole gamma camera collimation was introduced in the field of emission tomography. This collimation process simultaneously produces several images covering a limited angular range, which may then be recombined to obtain tomographic slices of the object imaged. A possible method for improving the images obtained by this technique by combining two multi-pinhole views taken 90 deg apart was investigated. Collimators were designed and built both for tomography and imaging tablet disintegration, and computer programs were written to reconstruct the images by simple backprojection and by filtered backprojection. The use of multi-pinhole collimators to image the disintegration of tablets in vivo was clearly demonstrated. Phantom tests done in vitro were capable of imaging defects as small as 5 sq mm, while images made with real tablets both in vitro and in vivo readily showed the onset and progress of the tablet disintegration.

Chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) with massive vertebral bone erosion: computed tomography (CT), magnetic resonance imaging (MRI) and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) findings.

Science.gov (United States)

Nakano, Sachiko; Okauchi, Kenzo; Tsushima, Yoshito

2014-02-01

A 62-year-old male presented with sudden onset of low back and right leg pain. Contrast-enhanced computed tomography demonstrated an abdominal aortic aneurysm (AAA), along with a large mass lesion causing vertebral body erosion. Magnetic resonance imaging (MRI) suggested that the mass lesion consisted of a chronic hematoma. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated increased uptake around the mass lesion, but not around the AAA. Surgical intervention was performed, and the subsequent histological diagnosis was chronic contained rupture of AAA. The mass lesion consisted of chronic hematoma and necrosis with inflammatory cell infiltration and hemosiderin deposition. This condition mimics some neoplastic diseases, but MRI and FDG-PET findings may help establish the correct diagnosis.

Identification of a unique cause of ring artifact seen in computed tomography trans-axial images

International Nuclear Information System (INIS)

Jha, Ashish Kumar; Purandare, Nilendu C; Shah, Sneha; Agrawal, Archi; Puranik, Ameya D; Rangarajan, Venkatesh

2013-01-01

Artifacts present in computed tomography (CT) image often degrade the image quality and ultimately, the diagnostic outcome. Ring artifact in trans-axial image is caused by either miscalibrated or defective detector element of detector row, which is often categorized as scanner based artifact. A ring artifact detected on trans-axial CT image of positron emission tomography/computed tomography (PET/CT), was caused by contamination of CT tube aperture by droplet of injectable contrast medium. This artifact was corrected by removal of contrast droplet from CT tube aperture. The ring artifact is a very common artifact, commonly cited in the literature. Our case puts forward an uncommon cause of this artifact and its method of correction, which also, has no mention in the existing literature

Fluorodeoxyglucose positron emission tomography in pancreatic cancer: an unsolved problem

International Nuclear Information System (INIS)

Kato, Takashi; Fukatsu, Hiroshi; Ito, Kengo; Tadokoro, Masanori; Ota, Toyohiro; Ikeda, Mitsuru; Isomura, Takayuki; Ito, Shigeki; Nishino, Masanari; Ishigaki, Takeo

1995-01-01

The aim of this study was to examine the significance and problems of 2-[fluorine-18]-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in diagnosing pancreatic cancer and mass-forming pancreatitis (MFP). PET, X-ray computed tomography (CT) and magnetic resonance (MR) imaging were performed in 15 patients with pancreatic cancer and nine patients with MFP. The areas of the PET scan were determined according to the markers drawn on the patients at CT or MR imaging. Regions of interests (ROIs) were placed by reference to the CT or MR images corresponding to the PET images. Tissue metabolism was evaluated by the differential absorption ratio (DAR) at 50 min after intravenous injection of FDG [DAR = tissue tracer concentration/(injected dose/body weight). The DAR value differed significantly in pancreatic cancer (mean±SD, 4.64±1.94) and MFP (mean±SD, 2.84±2.22) (P<0.05). In one false-negative case (mucinous adenocarcinoma), the tumour contained a small number of malignant cells. In one false-positive case, lymphocytes accumulated densely in the mass in the pancreatic head. Further studies are necessary to investigate the histopathological characteristics (especially the cellularity) and other factors affecting the FDG DAR on PET images. (orig.)

A Dual Reporter Iodinated Labeling Reagent for Cancer Positron Emission Tomography Imaging and Fluorescence-Guided Surgery

Science.gov (United States)

2018-01-01

The combination of early diagnosis and complete surgical resection offers the greatest prospect of curative cancer treatment. An iodine-124/fluorescein-based dual-modality labeling reagent, 124I-Green, constitutes a generic tool for one-step installation of a positron emission tomography (PET) and a fluorescent reporter to any cancer-specific antibody. The resulting antibody conjugate would allow both cancer PET imaging and intraoperative fluorescence-guided surgery. 124I-Green was synthesized in excellent radiochemical yields of 92 ± 5% (n = 4) determined by HPLC with an improved one-pot three-component radioiodination reaction. The A5B7 carcinoembryonic antigen (CEA)-specific antibody was conjugated to 124I-Green. High tumor uptake of the dual-labeled A5B7 of 20.21 ± 2.70, 13.31 ± 0.73, and 10.64 ± 1.86%ID/g was observed in CEA-expressing SW1222 xenograft mouse model (n = 3) at 24, 48, and 72 h post intravenous injection, respectively. The xenografts were clearly visualized by both PET/CT and ex vivo fluorescence imaging. These encouraging results warrant the further translational development of 124I-Green for cancer PET imaging and fluorescence-guided surgery. PMID:29388770

Positron emission tomography now and in the future

International Nuclear Information System (INIS)

Vaalburg, W.

1987-01-01

A survey is given of positron emission tomography used in nuclear medicine. The production of positron emitting radionuclides is discussed. The development of positron detectors is described. The application of positron emission tomography in cardiology, oncology and neurology is treated. The authors conclude that PET is a unique method to examine metabolic processes, although the method is still in its infancy. 7 refs.; 1 table

Towards a practical implementation of the MLE algorithm for positron emission tomography

International Nuclear Information System (INIS)

Llacer, J.; Andreae, S.; Veklerov, E.; Hoffman, E.J.

1986-01-01

Recognizing that the quality of images obtained by application of the Maximum Likelihood Estimator (MLE) to Positron Emission Tomography (PET) and Single Photon Emission Tomography (SPECT) appears to be substantially better than those obtained by conventional methods, the authors have started to develop methods that will facilitate the necessary research for a good evaluation of the algorithm and may lead to its practical application for research and routine tomography. They have found that the non-linear MLE algorithm can be used with pixel sizes which are smaller than the sampling distance, without interpolation, obtaining excellent resolution and no noticeable increase in noise. They have studied the role of symmetry in reducing the amount of matrix element storage requirements for full size applications of the algorithm and have used that concept to carry out two reconstructions of the Derenzo phantom with data from the ECAT-III instrument. The results show excellent signal-to-noise (S/N) ratio, particularly for data with low total counts, excellent sharpness, but low contrast at high frequencies when using the Shepp-Vardi model for probability matrices

Astigmatic single photon emission computed tomography imaging with a displaced center of rotation

International Nuclear Information System (INIS)

Wang, H.; Smith, M.F.; Stone, C.D.; Jaszczak, R.J.

1998-01-01

A filtered backprojection algorithm is developed for single photon emission computed tomography (SPECT) imaging with an astigmatic collimator having a displaced center of rotation. The astigmatic collimator has two perpendicular focal lines, one that is parallel to the axis of rotation of the gamma camera and one that is perpendicular to this axis. Using SPECT simulations of projection data from a hot rod phantom and point source arrays, it is found that a lack of incorporation of the mechanical shift in the reconstruction algorithm causes errors and artifacts in reconstructed SPECT images. The collimator and acquisition parameters in the astigmatic reconstruction formula, which include focal lengths, radius of rotation, and mechanical shifts, are often partly unknown and can be determined using the projections of a point source at various projection angles. The accurate determination of these parameters by a least squares fitting technique using projection data from numerically simulated SPECT acquisitions is studied. These studies show that the accuracy of parameter determination is improved as the distance between the point source and the axis of rotation of the gamma camera is increased. The focal length to the focal line perpendicular to the axis of rotation is determined more accurately than the focal length to the focal line parallel to this axis. copyright 1998 American Association of Physicists in Medicine

Monitoring of herpes simplex virus thymidine kinase enzyme activity using positron emission tomography

NARCIS (Netherlands)

Hospers, GAP; Calogero, Anna; van Waarde, A; Doze, P; Vaalburg, W; Mulder, NH; de Vries, EFJ

2000-01-01

9-[(1-[F-18]Fluoro-3-hydroxy-2-propoxy)methyl]guanine ([F-18]FHPG) wasevaluated as a tracer for noninvasive positron emission tomography (PET) imaging of herpes simplex virus type 1 thymidine kinase (HSV-tk) gene expression. C6 rat glioma cells with and without the HSV-tk gene were incubated with

Positron emission tomography. Present status and Romanian perspectives

International Nuclear Information System (INIS)

Constantinescu, B.; Lungu, V.

1995-01-01

Basic principles of the positron emission tomography (PET) are summarised. The main PET methods using short-lived radioisotopes (i.e. 11 C, 13 N, 15 O, 18 F) are briefly reviewed. Three types of particle accelerators for radioisotopes production and medical uses (including radiotherapy), corresponding to the proton energy (E p p p < 200 MeV) are presented. PET imaging equipment and procedures are discussed. Main radiopharmaceuticals based on beta decay for PET studies and their role in medicine is also described. Finally, perspectives for a PET program in Romania (Cyclotron + Radiochemistry + Tomograph ) are discussed. (author)

The Comparison of Computed Tomography Perfusion, Contrast-Enhanced Computed Tomography and Positron-Emission Tomography/Computed Tomography for the Detection of Primary Esophageal Carcinoma.

Science.gov (United States)

Genc, Berhan; Kantarci, Mecit; Sade, Recep; Orsal, Ebru; Ogul, Hayri; Okur, Aylin; Aydin, Yener; Karaca, Leyla; Eroğlu, Atilla

2016-01-01

The purpose of this study was to investigate the efficiency of computed tomography perfusion (CTP), contrast-enhanced computed tomography (CECT) and 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron-emission tomography (PET/CT) in the diagnosis of esophageal cancer. This prospective study consisted of 33 patients with pathologically confirmed esophageal cancer, 2 of whom had an esophageal abscess. All the patients underwent CTP, CECT and PET/CT imaging and the imaging findings were evaluated. Sensitivity, specificity and positive and negative predictive values were calculated for each of the 3 imaging modalities relative to the histological diagnosis. Thirty-three tumors were visualized on CTP, 29 on CECT and 27 on PET/CT. Six tumors were stage 1, and 2 and 4 of these tumors were missed on CECT and PET/CT, respectively. Significant differences between CTP and CECT (p = 0.02), and between CTP and PET/CT (p = 0.04) were found for stage 1 tumors. Values for the sensitivity, specificity and positive and negative predictive values on CTP were 100, 100, 100 and 100%, respectively. Corresponding values on CECT were 93.94, 0, 93.94 and 0%, respectively, and those on PET/CT were 87.88, 0, 93.55 and 0%, respectively. Hence, the sensitivity, specificity and positive and negative predictive values of CTP were better than those of CECT and PET/CT. CTP had an advantage over CECT and PET/CT in detecting small lesions. CTP was valuable, especially in detecting stage 1 tumors. © 2016 S. Karger AG, Basel.

Geneva University - The AX-PET experiment : A demonstrator for an axial Positron Emission Tomography

CERN Multimedia

Université de Genève

2012-01-01

Geneva University École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92   Wednesday 14 March 2012 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE 11.15 a.m. - Science II, Auditoire 1S081, 30, quai Ernest-Ansermet, 1211 Genève 4 The AX-PET experiment : A demonstrator for an axial Positron Emission Tomography Dr Chiara CASELLA   ETH Zurich   PET (Positron Emission Tomography) is a tool for in-vivo functional imaging, successfully used since the earliest days of nuclear medicine. It is based on the detection of the two coincident 511 keV photons from the annihilation of a positron, emitted from a radiotracer injected into the body. Tomographic analysis of the coincidence data allows for a 3D reconstructed image of the source distribution. The AX-PET experiment proposes a novel geometrical approach for a PET scanner, in which l...

A statistical analysis of count normalization methods used in positron-emission tomography

International Nuclear Information System (INIS)

Holmes, T.J.; Ficke, D.C.; Snyder, D.L.

1984-01-01

As part of the Positron-Emission Tomography (PET) reconstruction process, annihilation counts are normalized for photon absorption, detector efficiency and detector-pair duty-cycle. Several normalization methods of time-of-flight and conventional systems are analyzed mathematically for count bias and variance. The results of the study have some implications on hardware and software complexity and on image noise and distortion

The Medical Case for a Positron Emission Tomography and X-ray Computed Tomography Combined Service in Oman.

Science.gov (United States)

Al-Bulushi, Naima K; Bailey, Dale; Mariani, Giuliano

2013-11-01

The value of a positron emission tomography and X-ray computed tomography (PET/CT) combined service in terms of diagnostic accuracy, cost-effectiveness and impact on clinical decision-making is well-documented in the literature. Its role in the management of patients presenting with cancer is shifting from early staging and restaging to the early assessment of the treatment response. Currently, the application of PET/CT has extended to non-oncological specialties-mainly neurology, cardiology and rheumatology. A further emerging application for PET/CT is the imaging of infection/inflammation. This article illustrates some of the PET/CT applications in both oncological and non-oncological disorders. In view of the absence of this modality in Oman, this article aims to increase the awareness of the importance of these imaging modalities and their significant impact on diagnosis and management in both oncological and non-oncological specialties for patients of all age groups as well as the decision-makers.

Systematic screening of imaging biomarkers for the Islets of Langerhans, among clinically available positron emission tomography tracers

International Nuclear Information System (INIS)

Karlsson, Filip; Antonodimitrakis, Pantelis Clewemar; Eriksson, Olof

2015-01-01

Introduction: Functional imaging could be utilized for visualizing pancreatic islets of Langerhans. Therefore, we present a stepwise algorithm for screening of clinically available positron emission tomography (PET) tracers for their use in imaging of the neuroendocrine pancreas in the context of diabetes. Methods: A stepwise procedure was developed for screening potential islet imaging agents. Suitable PET-tracer candidates were identified by their molecular mechanism of targeting. Clinical abdominal examinations were retrospectively analyzed for pancreatic uptake and retention. The target protein localization in the pancreas was assessed in silico by –omics approaches and the in vitro by binding assays to human pancreatic tissue. Results: Six putative candidates were identified and screened by using the stepwise procedure. Among the tested PET tracers, only [ 11 C]5-Hydroxy-tryptophan passed all steps. The remaining identified candidates were falsified as candidates and discarded following in silico and in vitro screening. Conclusions: Of the six clinically available PET tracers identified, [ 11 C]5-HTP was found to be a promising candidate for beta cell imaging, based on intensity of in vivo pancreatic uptake in humans, and islet specificity as assessed on human pancreatic cell preparations. The flow scheme described herein constitutes a methodology for evaluating putative islet imaging biomarkers among clinically available PET tracers

[11C]CURB: Evaluation of a novel radiotracer for imaging fatty acid amide hydrolase by positron emission tomography

International Nuclear Information System (INIS)

Wilson, Alan A.; Garcia, Armando; Parkes, Jun; Houle, Sylvain; Tong, Junchao; Vasdev, Neil

2011-01-01

Introduction: Fatty acid amide hydrolase (FAAH) is the enzyme responsible for metabolising the endogenous cannabinoid, anandamide, and thus represents an important target for molecular imaging. To date, no radiotracer has been shown to be useful for imaging of FAAH using either positron emission tomography (PET) or single photon emission computed tomography (SPECT). We here determine the suitability of a novel carbon-11-labeled inhibitor of FAAH via ex vivo biodistribution studies in rat brain in conjunction with pharmacological challenges. Methods: A potent irreversible inhibitor of FAAH, URB694, radiolabeled with carbon-11 in the carbonyl position ([ 11 C]CURB), was administered to male rats via tail-vein injection. Rats were sacrificed at various time points postinjection, and tissue samples were dissected, counted and weighed. Specific binding to FAAH was investigated by pretreatment of animals with URB694 or URB597. For metabolism and mechanism of binding studies, whole brains were excised post-radiotracer injection, homogenised and extracted exhaustively with 80% aq. acetonitrile to determine the time course and fraction of radioactivity that was irreversibly bound to brain parenchyma. Results: Upon intravenous injection into rats, [ 11 C]CURB showed high brain uptake [standard uptake value (SUV) of 1.6-2.4 at 5 min] with little washout over time, which is characteristic of irreversible binding. Highest uptake of radioactivity was seen in the cortex, intermediate in the cerebellum and lowest in the hypothalamus, reflecting the reported distribution of FAAH. Brain uptake of radioactivity was decreased in a dose-dependent manner by pretreatment with increasing amounts of URB694, demonstrating that binding was saturable. Pretreatment with the well-characterised FAAH inhibitor, URB597, reduced binding in all brain regions by 70-80%. Homogenised brain extraction experiments demonstrated unequivocally that [ 11 C]CURB was irreversibly bound to FAAH. Conclusions

Radiolabelled molecules for imaging the translocator protein (18 kDa) using positron emission tomography

International Nuclear Information System (INIS)

Dolle, F.; Luus, C.; Reynolds, A.; Kassiou, M.

2009-01-01

The translocator protein (18 kDa) (TSPO), formerly known as the peripheral benzodiazepine receptor (PBR), was originally identified as an alternate binding site for the central benzodiazepine receptor (CBR) ligand, diazepam, in the periphery, but has now been distinguished as a novel site. The TSPO is ubiquitously expressed in peripheral tissues but only minimally in the healthy brain and increased levels of TSPO expression have been noted in neuro inflammatory conditions such as Alzheimer's disease, Parkinson's disease and stroke. This increase in TSPO expression has been reported to coincide with the process of micro-glial activation, whereby the brain's intrinsic immune system becomes active. Therefore, by using recently developed high affinity, selective TSPO ligands in conjunction with functional imaging modalities such as positron emission tomography (PET), it becomes possible to study the process of micro-glial activation in the living brain. A number of high affinity ligands, the majority of which are C, N-substituted acetamide derivatives, have been successfully radiolabelled and used in in vivo studies of the TSPO and the process of micro-glial activation. This review highlights recent achievements (up to December 2008) in the field of functional imaging of the TSPO as well as the radio-syntheses involved in such studies. (authors)

Positron emission tomography studies of brain receptors

International Nuclear Information System (INIS)

Maziere, B.; Maziere, M.

1991-01-01

Probing the regional distribution and affinity of receptors in the brain, in vivo, in human and non human primates has become possible with the use of selective ligands labelled with positron emitting radionuclides and positron emission tomography (PET). After describing the techniques used in positron emission tomography to characterize a ligand receptor binding and discussing the choice of the label and the limitations and complexities of the in vivo approach, the results obtained in the PET studies of various neurotransmission systems: dopaminergic, opiate, benzodiazepine, serotonin and cholinergic systems are reviewed

A case of skeletal tuberculosis and psoas abscess: disease activity evaluated using 18 F-fluorodeoxyglucose positron emission tomography-computed tomography

International Nuclear Information System (INIS)

Kimizuka, Yoshifumi; Hasegawa, Naoki; Ishii, Makoto; Murakami, Koji; Ishioka, Kota; Yagi, Kazuma; Ishii, Ken; Watanabe, Kota; Soejima, Kenzo; Betsuyaku, Tomoko

2013-01-01

Psoas abscess complicating tuberculous spondylitis is a rare morbidity in extrapulmonary tuberculosis. There are no established guidelines for evaluating the clinical response of psoas abscess. Although several studies have shown that positron emission tomography-computed tomography with 18 F-fluorodeoxyglucose can play a potential role in diagnosing multifocal tuberculosis and monitoring the clinical response of pulmonary tuberculosis, to our knowledge, this is the first report demonstrating that positron emission tomography-computed tomography is useful for evaluating local inflammation and disease activity of a tuberculous psoas abscess. We report a case of multifocal bone and lymph node tuberculosis with concomitant lumbar psoas abscess in a 77-year-old man, along with a literature review. An initial positron emission tomography-computed tomography scan showed intense 18 F-fluorodeoxyglucose accumulation in the sternum, ribs, vertebrae, and lymph nodes. The patient was successfully treated with antitubercular agents and computed tomography-guided drainage therapy. A follow-up positron emission tomography-computed tomography after abscess drainage and 9 months of antitubercular drug treatment revealed that the majority of lesions improved; however, protracted inflammation surrounding the psoas abscess was still observed. These results indicate that disease activity of psoas abscess can remain, even after successful drainage and antitubercular medication regime of appropriate duration. We have successfully followed up the extent of skeletal tuberculosis complicated with psoas abscess by positron emission tomography-computed tomography. In this patient, positron emission tomography-computed tomography is useful for evaluating the disease activity of tuberculous psoas abscess and for assessing the appropriate duration of antitubercular drug therapy in psoas abscess

Value of image fusion using single photon emission computed tomography with integrated low dose computed tomography in comparison with a retrospective voxel-based method in neuroendocrine tumours

International Nuclear Information System (INIS)

Amthauer, H.; Denecke, T.; Ruf, J.; Gutberlet, M.; Felix, R.; Lemke, A.J.; Rohlfing, T.; Boehmig, M.; Ploeckinger, U.

2005-01-01

The objective was the evaluation of single photon emission computed tomography (SPECT) with integrated low dose computed tomography (CT) in comparison with a retrospective fusion of SPECT and high-resolution CT and a side-by-side analysis for lesion localisation in patients with neuroendocrine tumours. Twenty-seven patients were examined by multidetector CT. Additionally, as part of somatostatin receptor scintigraphy (SRS), an integrated SPECT-CT was performed. SPECT and CT data were fused using software with a registration algorithm based on normalised mutual information. The reliability of the topographic assignment of lesions in SPECT-CT, retrospective fusion and side-by-side analysis was evaluated by two blinded readers. Two patients were not enrolled in the final analysis because of misregistrations in the retrospective fusion. Eighty-seven foci were included in the analysis. For the anatomical assignment of foci, SPECT-CT and retrospective fusion revealed overall accuracies of 91 and 94% (side-by-side analysis 86%). The correct identification of foci as lymph node manifestations (n=25) was more accurate by retrospective fusion (88%) than from SPECT-CT images (76%) or by side-by-side analysis (60%). Both modalities of image fusion appear to be well suited for the localisation of SRS foci and are superior to side-by-side analysis of non-fused images especially concerning lymph node manifestations. (orig.)

Early-Dynamic Positron Emission Tomography (PET)/Computed Tomography and PET Angiography for Endoleak Detection After Endovascular Aneurysm Repair.

Science.gov (United States)

Drescher, Robert; Gühne, Falk; Freesmeyer, Martin

2017-06-01

To propose a positron emission tomography (PET)/computed tomography (CT) protocol including early-dynamic and late-phase acquisitions to evaluate graft patency and aneurysm diameter, detect endoleaks, and rule out graft or vessel wall inflammation after endovascular aneurysm repair (EVAR) in one examination without intravenous contrast medium. Early-dynamic PET/CT of the endovascular prosthesis is performed for 180 seconds immediately after intravenous injection of F-18-fluorodeoxyglucose. Data are reconstructed in variable time frames (time periods after tracer injection) to visualize the arterial anatomy and are displayed as PET angiography or fused with CT images. Images are evaluated in view of vascular abnormalities, graft configuration, and tracer accumulation in the aneurysm sac. Whole-body PET/CT is performed 90 to 120 minutes after tracer injection. This protocol for early-dynamic PET/CT and PET angiography has the potential to evaluate vascular diseases, including the diagnosis of complications after endovascular procedures.

Lynch Syndrome Associated Colon Adenocarcinoma Resembling Lymphoma on Fluoro-Deoxyglucose-Positron Emission Tomography/Computed Tomography

International Nuclear Information System (INIS)

Aparici, Carina Mari; Win, Aung Zaw

2015-01-01

The patient was a 46-year-old Asian male diagnosed with lynch syndrome associated colon adenocarcinoma in the right ascending colon. A presurgical staging 18-fluoro-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) found increased metabolic activity in the cervical, axillary, mediastinal, supraclavicular, para-aortic and mesenteric lymph nodes. This pattern of metastasis was very unusual for lynch syndrome associated colon adenocarcinoma and the involvement of those lymph nodes resembles the pattern of spread of lymphoma. He underwent right hemicolectomy and he was subsequently treated with 12 cycles of folinic acid (leucovorin), fluorouracil (5-FU), irinotecan. A restaging FDG-PET/CT at the end of the chemotherapy showed interval decrease in size and metabolic activity in the affected lymph nodes. FDG-PET/CT is a useful imaging modality in following-up the treatment response in colon adenocarcinoma

Preamputation evaluation of lower-limb skeletal muscle perfusion with H(2) (15)O positron emission tomography.

Science.gov (United States)

Scremin, Oscar U; Figoni, Stephen F; Norman, Keith; Scremin, A M Erika; Kunkel, Charles F; Opava-Rutter, Dorene; Schmitter, Eric D; Bert, Alberto; Mandelkern, Mark

2010-06-01

To establish whether muscle blood flow (MBF) measurements with O-water positron emission tomography could reliably identify patients with critical limb ischemia and detect and quantify a distal deficit in skeletal MBF in these cases. O-water positron emission tomography scans were performed at rest or during unloaded ankle plantar and dorsiflexion exercise of the diseased leg in 17 subjects with leg ischemia or on a randomly selected leg of 18 age-matched healthy control subjects. TcPO2 was evaluated with Novametrix monitors and perfusion of skin topically heated to 44 degrees C and adjacent nonheated areas with a Moor Instruments laser Doppler imaging scanner. The enhancement of MBF induced by exercise was significantly lower in ischemic than in normal legs, and the sensitivity and specificity of this phenomenon were similar to those of laser Doppler imaging or TcPO2 in identifying ischemia subjects. In addition, the exercise MBF deficit was predominant at the distal-leg levels, indicating the ability of the technique to help determine the correct level of amputation. Skeletal MBF of legs with severe ischemia can be detected accurately with O-water positron emission tomography and could add valuable information about viability of skeletal muscle in the residual limb when deciding the level of an amputation.

Multimodality imaging using proton magnetic resonance spectroscopic imaging and 18F-fluorodeoxyglucose-positron emission tomography in local prostate cancer

Science.gov (United States)

Shukla-Dave, Amita; Wassberg, Cecilia; Pucar, Darko; Schöder, Heiko; Goldman, Debra A; Mazaheri, Yousef; Reuter, Victor E; Eastham, James; Scardino, Peter T; Hricak, Hedvig

2017-01-01

AIM To assess the relationship using multimodality imaging between intermediary citrate/choline metabolism as seen on proton magnetic resonance spectroscopic imaging (1H-MRSI) and glycolysis as observed on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in prostate cancer (PCa) patients. METHODS The study included 22 patients with local PCa who were referred for endorectal magnetic resonance imaging/1H-MRSI (April 2002 to July 2007) and 18F-FDG-PET/CT and then underwent prostatectomy as primary or salvage treatment. Whole-mount step-section pathology was used as the standard of reference. We assessed the relationships between PET parameters [standardized uptake value (SUVmax and SUVmean)] and MRSI parameters [choline + creatine/citrate (CC/Cmax and CC/Cmean) and total number of suspicious voxels] using spearman’s rank correlation, and the relationships of PET and 1H-MRSI index lesion parameters to surgical Gleason score. RESULTS Abnormal intermediary metabolism on 1H-MRSI was present in 21/22 patients, while abnormal glycolysis on 18F-FDG-PET/CT was detected in only 3/22 patients. Specifically, index tumor localization rates were 0.95 (95%CI: 0.77-1.00) for 1H-MRSI and 0.14 (95%CI: 0.03-0.35) for 18F-FDG-PET/CT. Spearman rank correlations indicated little relationship (ρ = -0.36-0.28) between 1H-MRSI parameters and 18F-FDG-PET/CT parameters. Both the total number of suspicious voxels (ρ = 0.55, P = 0.0099) and the SUVmax (ρ = 0.46, P = 0.0366) correlated weakly with the Gleason score. No significant relationship was found between the CC/Cmax, CC/Cmean or SUVmean and the Gleason score (P = 0.15-0.79). CONCLUSION The concentration of intermediary metabolites detected by 1H MRSI and glycolytic flux measured 18F-FDG PET show little correlation. Furthermore, only few tumors were FDG avid on PET, possibly because increased glycolysis represents a late and rather ominous event in the progression of PCa. PMID:28396727

Hybrid Single Photon Emission Computed Tomography/Computed Tomography Sulphur Colloid Scintigraphy in Focal Nodular Hyperplasia

International Nuclear Information System (INIS)

Bhoil, Amit; Gayana, Shankramurthy; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

2013-01-01

It is important to differentiate focal nodular hyperplasia (FNH), a benign condition of liver most commonly affecting women, from other neoplasm such as hepatic adenoma and metastasis. The functional reticuloendothelial features of FNH can be demonstrated by scintigraphy. We present a case of breast cancer in whom fluorodeoxyglucose positron emission tomography/computerized tomography (CT) showed a homogenous hyperdense lesion in liver, which on Tc99m sulfur colloid single-photon emission computed tomography/CT was found to have increased focal tracer uptake suggestive of FNH

Fluorodeoxyglucose positron emission tomography scan may be helpful in the case of ductal variant prostate cancer when prostate specific membrane antigen ligand positron emission tomography scan is negative

International Nuclear Information System (INIS)

McEwan, Louise M.; Wong, David; Yaxley, John

2017-01-01

Gallium-68 prostate specific membrane antigen ligand (Ga-68 PSMA) positron emission tomography/computed tomography (PET/CT) scanning is emerging as a useful imaging modality for the staging of suspected and known recurrent or metastatic prostate cancer and in staging of newly diagnosed higher grade prostate cancer. However, we have observed at our institution that in some cases of the more aggressive ductal variant, Ga-68 PSMA uptake has sometimes been poor compared with prominent 18-fluorodeoxyglucose (F-18 FDG) avidity seen in F-18 FDG PET/CT, which would suggest that FDG PET/CT scans are important in staging of ductal pattern prostate cancer.

Chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) with massive vertebral bone erosion. Computed tomography (CT), magnetic resonance imaging (MRI) and fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) findings

International Nuclear Information System (INIS)

Nakano, Sachiko; Okauchi, Kenzo; Tsushima, Yoshito

2014-01-01

A 62-year-old male presented with sudden onset of low back and right leg pain. Contrast-enhanced computed tomography demonstrated an abdominal aortic aneurysm (AAA), along with a large mass lesion causing vertebral body erosion. Magnetic resonance imaging (MRI) suggested that the mass lesion consisted of a chronic hematoma. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated increased uptake around the mass lesion, but not around the AAA. Surgical intervention was performed, and the subsequent histological diagnosis was chronic contained rupture of AAA. The mass lesion consisted of chronic hematoma and necrosis with inflammatory cell infiltration and hemosiderin deposition. This condition mimics some neoplastic diseases, but MRI and FDG-PET findings may help establish the correct diagnosis. (author)

The value of positron emission tomography/computed tomography for evaluating metastatic disease in patients with pancreatic cancer.

Science.gov (United States)

Kim, Mi-Jin; Lee, Kwang Hyuck; Lee, Kyu Taek; Lee, Jong Kyun; Ku, Bon-Ho; Oh, Cho-Rong; Heo, Jin Seok; Choi, Seong-Ho; Choi, Dong Wook

2012-08-01

Routine application of positron emission tomography/computed tomography (PET/CT) for pancreatic cancer staging remains a controversial approach. The purpose of this study was to reassess the clinical impact of PET/CT for the detection of distant metastasis of pancreatic cancer. From January 2006 to June 2009, 125 patients with histologically proven pancreatic cancer that had undergone PET/CT at our hospital were retrospectively reviewed. To evaluate the clinical efficacy of PET/CT on the management plan, the post-PET/CT management plans were compared with the pre-PET/CT management plans. After the conventional staging workup, we determined that 76 patients (60.8%) had resectable lesions, whereas 48 patients had unresectable lesions. One patient underwent explorative laparotomy due to equivocal resectability. Positron emission tomography/computed tomography diagnosed distant metastasis in only 2 (2.6%) of the 76 patients with resectable lesions, and these patients did not undergo unnecessary surgical treatment. Complete resection was not performed in 8 of the 74 operative patients because they had distant metastasis detected during the operative procedure. Positron emission tomography/computed tomography diagnosed distant metastasis in 32 of the 44 patients with metastatic lesions that were histologically shown to have sensitivity of 72.7%. Positron emission tomography/computed tomography has a limited role in the evaluation of metastatic disease from pancreatic cancer.

Benign thyroid and neck lesions mimicking malignancy with false positive findings on positron emission tomography-computed tomography

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ye Ri; Kim, Shin Young; Lee, Sang Mi [Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of); Lee, Deuk Young [Dept. of Surgery, Younsei Angelot Women' s Clinic, Cheonan (Korea, Republic of)

2017-02-15

The increasing use of positron emission tomography-computed tomography (PET/CT) has led to the frequent detection of incidental thyroid and neck lesions with increased 18F-deoxyglucose (FDG) uptake. Although lesions with increased FDG uptake are commonly assumed to be malignant, benign lesions may also exhibit increased uptake. The purpose of this pictorial essay is to demonstrate that benign thyroid and neck lesions can produce false-positive findings on PET/CT, and to identify various difficulties in interpretation. It is crucial to be aware that differentiating between benign and malignant lesions is difficult in a considerable proportion of cases, when relying only on PET/CT findings. Correlation of PET/CT findings with additional imaging modalities is essential to avoid misdiagnosis.

Utility of single photon emission computed tomography/computed tomography imaging in evaluation of chronic low back pain

International Nuclear Information System (INIS)

Harisankar, Chidambaram Natrajan Balasubramanian; Mittal, Bhagwant Rai; Bhattacharya, Anish; Singh, Paramjeet; Sen, Ramesh

2012-01-01

Abnormal morphologic findings in imaging were thought to explain the etiology of low back pain (LBP). However, it is now known that variety of morphologic abnormalities is noted even in asymptomatic individuals. Single photon emission computed tomography/computed tomography (SPECT/CT) could be used to differentiate incidental findings from clinically significant findings. This study was performed to define the SPECT/CT patterns in patients with LBP and to correlate these with clinical and magnetic resonance imaging (MRI) findings. Thirty adult patients with LBP of duration 3 months or more were prospectively evaluated in this study. Patients with known or suspected malignancy, trauma or infectious processes were excluded. A detailed history of sensory and motor symptoms and neurologic examination was performed. All the patients were subjected to MRI and bone scintigraphy with hybrid SPECT/CT of the lumbo-sacral spine within 1 month of each other. The patients were classified into those with and without neurologic symptoms, activity limitation. The findings of clinical examination and imaging were compared. MRI and SPECT/CT findings were also compared. Thirty patients (18 men and 12 women; mean age 38 years; range 17-64 years) were eligible for the study. Clinically, 14 of 30 (46%) had neurologic signs and or symptoms. Six of the 30 patients (20%) had positive straight leg raising test (SLRT). Twenty-two of the 30 patients (73%) had SPECT abnormality. Most frequent SPECT/CT abnormality was tracer uptake in the anterior part of vertebral body with osteophytes/sclerotic changes. Significant positive agreement was noted between this finding and MRI evidence of degenerative disc disease. Only 13% of patients had more than one abnormality in SPECT. All 30 patients had MRI abnormalities. The most frequent abnormality was degenerative disc disease and facet joint arthropathy. MRI showed single intervertebral disc abnormality in 36% of the patients and more than one

Radiolabeled, Antibody-Conjugated Manganese Oxide Nanoparticles for Tumor Vasculature Targeted Positron Emission Tomography and Magnetic Resonance Imaging.

Science.gov (United States)

Zhan, Yonghua; Shi, Sixiang; Ehlerding, Emily B; Graves, Stephen A; Goel, Shreya; Engle, Jonathan W; Liang, Jimin; Tian, Jie; Cai, Weibo

2017-11-08

Manganese oxide nanoparticles (Mn 3 O 4 NPs) have attracted a great deal of attention in the field of biomedical imaging because of their ability to create an enhanced imaging signal in MRI as novel potent T 1 contrast agents. In this study, we present tumor vasculature-targeted imaging in mice using Mn 3 O 4 NPs through conjugation to the anti-CD105 antibody TRC105 and radionuclide copper-64 ( 64 Cu, t 1/2 : 12.7 h). The Mn 3 O 4 conjugated NPs, 64 Cu-NOTA-Mn 3 O 4 @PEG-TRC105, exhibited sufficient stability in vitro and in vivo. Serial positron emission tomography (PET) and magnetic resonance imaging (MRI) studies evaluated the pharmacokinetics and demonstrated targeting of 64 Cu-NOTA-Mn 3 O 4 @PEG-TRC105 to 4T1 murine breast tumors in vivo, compared to 64 Cu-NOTA-Mn 3 O 4 @PEG. The specificity of 64 Cu-NOTA-Mn 3 O 4 @PEG-TRC105 for the vascular marker CD105 was confirmed through in vivo, in vitro, and ex vivo experiments. Since Mn 3 O 4 conjugated NPs exhibited desirable properties for T 1 enhanced imaging and low toxicity, the tumor-specific Mn 3 O 4 conjugated NPs reported in this study may serve as promising multifunctional nanoplatforms for precise cancer imaging and diagnosis.

A combined positron emission tomography (PET)- electron paramagnetic resonance imaging (EPRI) system: initial evaluation of a prototype scanner.

Science.gov (United States)

Tseytlin, Mark; Stolin, Alexander V; Guggilapu, Priyaankadevi; Bobko, Andrey A; Khramtsov, Valery V; Tseytlin, Oxana; Raylman, Raymond R

2018-04-20

The advent of hybrid scanners, combining complementary modalities, has revolutionized imaging; enhancing clinical practice and biomedical research. In this project, we investigated the melding of two complementary, functional imaging methods: positron emission tomography (PET) and electron paramagnetic resonance imaging (EPRI). The PET radiotracers can provide important information about cellular parameters, such as glucose metabolism. While EPR probes can provide assessment of tissue microenvironment, measuring parameters such as oxygenation and pH, for example. A combined PET/EPRI scanner has the promise to provide new insights not attainable with current imagers by simultaneous acquisition of multiple components of tissue microenvironments. In this investigation, a prototype system was created by combing two existing scanners, modified for simultaneous imaging. Specifically, a silicon photomultiplier (SiPM) based PET scanner ring designed as a portable scanner was combined with an EPRI scanner designed for the imaging of small animals. The ability of the system to obtain simultaneous images was assessed with a small phantom consisting of four cylinders containing both PET and EPR tracers. The resulting images demonstrated the ability to obtain contemporaneous PET and ERP images without cross-modality interference. The next step in this project is the construction of pre-clinical PET/EPRI scanner for multi-parametric assessment of physiologically important parameters of tissue microenvironments. . © 2018 Institute of Physics and Engineering in Medicine.

A combined positron emission tomography (PET)-electron paramagnetic resonance imaging (EPRI) system: initial evaluation of a prototype scanner

Science.gov (United States)

Tseytlin, Mark; Stolin, Alexander V.; Guggilapu, Priyaankadevi; Bobko, Andrey A.; Khramtsov, Valery V.; Tseytlin, Oxana; Raylman, Raymond R.

2018-05-01

The advent of hybrid scanners, combining complementary modalities, has revolutionized the application of advanced imaging technology to clinical practice and biomedical research. In this project, we investigated the melding of two complementary, functional imaging methods: positron emission tomography (PET) and electron paramagnetic resonance imaging (EPRI). PET radiotracers can provide important information about cellular parameters, such as glucose metabolism. While EPR probes can provide assessment of tissue microenvironment, measuring oxygenation and pH, for example. Therefore, a combined PET/EPRI scanner promises to provide new insights not attainable with current imagers by simultaneous acquisition of multiple components of tissue microenvironments. To explore the simultaneous acquisition of PET and EPR images, a prototype system was created by combining two existing scanners. Specifically, a silicon photomultiplier (SiPM)-based PET scanner ring designed as a portable scanner was combined with an EPRI scanner designed for the imaging of small animals. The ability of the system to obtain simultaneous images was assessed with a small phantom consisting of four cylinders containing both a PET tracer and EPR spin probe. The resulting images demonstrated the ability to obtain contemporaneous PET and EPR images without cross-modality interference. Given the promising results from this initial investigation, the next step in this project is the construction of the next generation pre-clinical PET/EPRI scanner for multi-parametric assessment of physiologically-important parameters of tissue microenvironments.

Positron emission tomography-computed tomography protocol considerations for head and neck cancer imaging.

Science.gov (United States)

Escott, Edward J

2008-08-01

Positron emission tomographic-computed tomographic (PET-CT) imaging of patients with primary head and neck cancers has become an established approach for staging and restaging, as well as radiation therapy planning. The inherent co-registration of PET and CT images made possible by the integrated PET-CT scanner is particularly valuable in head and neck cancer imaging due to the complex and closely situated anatomy in this part of the body, the varied sources of physiologic and benign 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) tracer uptake that occurs in the neck, and the varied and complex posttreatment appearance of the neck. Careful optimization of both the CT and the PET portion of the examination is essential to insure the most accurate and clinically valuable interpretation of these examinations.

Clinicopathological and prognostic relevance of uptake level using 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in primary breast cancer

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