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Sample records for 18-fluorodeoxyglucose positron emission

  1. Molecular pathology in vulnerable carotid plaques: correlation with [18]-fluorodeoxyglucose positron emission tomography (FDG-PET)

    Graebe, M; Pedersen, Sune Folke; Borgwardt, L;

    2008-01-01

    OBJECTIVES: Atherosclerosis is recognised as an inflammatory disease, and new diagnostic tools are warranted to evaluate plaque inflammatory activity and risk of cardiovascular events. We investigated [18]-fluorodeoxyglucose (FDG) uptake in vulnerable carotid plaques visualised by positron emission...

  2. Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography in evaluation of residual intramuscular myxoma

    Intramuscular myxoma (IM) is a rare benign neoplasm. In a patient diagnosed with IM of left thigh, we report the utility of a postoperative fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography scan in assessing the efficacy of surgical excision

  3. Gliomatosis cerebri mimicking encephalitis evaluated using fluorine-18 fluorodeoxyglucose: Positron emission tomography/computed tomography

    Gliomatosis cerebri (GC) is a rare condition in which an infiltrative glial neoplasm spreads through the brain with preservation of the underlying structure. F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has an important role in demonstrating the appropriate metabolism and differentiating pathologies mimicking GC on CT and magnetic resonance imaging. We describe imaging findings of FDG PET/CT in GC in a 9-year-old male child mimicking encephalitis

  4. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of primary pulmonary angiosarcomas

    Angiosarcoma is a malignant vascular tumor that originates from the mesenchymal cells which have undergone angioblastic differentiation. Pulmonary angiosarcomas are invariably (>90%) metastatic tumors form primaries of the skin, bone, liver, breast, or heart. Primary pulmonary angiosarcomas are exceedingly rare, with just about 20 cases being reported in the literature. We report an additional case with a brief review of the literature of a primary pulmonary angiosarcoma in a 26-year-old lady who presented with intractable hemoptysis. In addition, we highlight the potential of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography as an important diagnostic tool in the evaluation of this tumor and thus contribute to the existing sparse literature on this fascinating yet devastating disease

  5. Unusual sites of metastatic recurrence of osteosarcoma detected on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    Osteosarcoma (OS) is the most common nonhematolymphoid primary bone malignancy characterized by osteoid or new bone formation. Lungs and bones are the most common sites of metastases. We report a case where unusual sites of the soft tissue recurrence from OS were detected on restaging fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography scan done post 6 years of disease free interval

  6. Preliminary assessment of fluorine-18 fluorodeoxyglucose positron emission tomography in patients with bladder cancer

    The purpose of this study was to assess the feasibility of imaging of bladder cancer with fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scanning. We studied 12 patients with histologically proven bladder cancer who had undergone surgical procedures and/or radiotherapy. Retrograde irrigation of the urinary bladder with 1000-3710 ml saline was performed during nine of the studies. Dynamic and static PET images were obtained, and standardized uptake value images were reconstructed. FDG-PET scanning was true-positive in eight patients (66.7%), but false-negative in four (33.3%). Of 20 organs with tumor mass lesions confirmed pathologically or clinically, 16 (80%) were detected by FDG-PET scanning. FDG-PET scanning detected all of 17 distant metastatic lesions and two of three proven regional lymph node metastases. FDG-PET was also capable of differentiating viable recurrent bladder cancer from radiation-induced alterations in two patients. In conclusion, these preliminary data indicate the feasibility of FDG-PET imaging in patients with bladder cancer, although a major remaining pitfall is intense FDG accumulation in the urine. (orig.). With 3 figs., 1 tab

  7. Fluorine-18 fluorodeoxyglucose positron emission tomography in the follow-up of differentiated thyroid cancer

    Whole-body fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging was performed during the follow-up of 33 patients suffering from differentiated thyroid cancer. Among them there were 26 patients with papillary and seven with follicular tumours. Primary tumour stage (pT) was pT1 in six cases, pT2 in eight cases, pT3 in three cases and pT4 in 14 cases. FDG PET was normal in 18 patients. In three patients a slightly increased metabolism was observed in the thyroid bed, assumed to be related to remnant tissue. In one case local recurrence, in ten cases lymph node metastases (one false-positive, caused by sarcoidosis) and in three cases distant metastases were found with FDG PET. In comparison with whole-body scintigraphy using iodine-131 (WBS) there were a lot of discrepancies in imaging results. Whereas three patients had distant metastases (proven with 131I) and a negative FDG PET, in four cases 131I-negative lymph node metastases were detectable with PET. Even in the patients with concordant ''staging'', differences between 131I and FDG were observed as to the exact lesion localization. Therefore, a coexistence of 131I-positive/FDG-negative, 131I-negative/FDG-positive and 131I-positive/FDG-positive malignant tissue can be assumed in these patients. A higher correlation of FDG PET was observed with hexakis (2-methoxyisobutylisonitrile) technetium-99m (I) (MIBI) scintigraphy (performed in 20 cases) than with WBS. In highly differentiated tumours 131I scintigraphy had a high sensitivity, whereas in poorly differentiated carcinomas FDG PET was superior. The clinical use of FDG PET can be recommended in all cases of suspected or proven recurrence and/or metastases of differentiated thyroid cancer and is particularly useful in cases with elevated serum thyroglobulin levels and negative WBS. (orig.). With 3 figs., 2 tabs

  8. Fluorine-18 fluorodeoxyglucose positron emission tomography in infectious bone diseases: results of histologically confirmed cases

    The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in acute and chronic osteomyelitis and inflammatory spondylitis. The study population comprised 21 patients suspected of having acute or chronic osteomyelitis or inflammatory spondylitis. Fifteen of these patients subsequently underwent surgery. FDG-PET results were correlated with histopathological findings. The remaining six patients, who underwent conservative therapy, were excluded from any further evaluation due to the lack of histopathological data. The histopathological findings revealed osteomyelitis or inflammatory spondylitis in all 15 patients: seven patients had acute osteomyelitis and eight patients had chronic osteomyelitis or inflammatory spondylitis. FDG-PET yielded 15 true-positive results. The tracer uptake correlated with the histopathological findings in each case. Bone scintigraphy performed in 11 patients yielded ten true-positive results and one false-negative result. Follow-up carried out on two patients revealed normal or clearly reduced tracer uptake, which correlated with a normalisation of clinical data. In early postoperative follow-up it was impossible to differentiate between postsurgical reactive changes and further infection using FDG-PET. It is concluded that acute and chronic osteomyelitis of the peripheral as well as the central skeleton can be detected using FDG-PET. Osteomyelitis can be differentiated from soft tissue infection surrounding the bone. Unlike computed tomography and magnetic resonance imaging, FDG-PET is not affected by metal implants used for fixing fractures. FDG-PET demonstrated promising initial results with respect to treatment monitoring. Nevertheless, in the early postoperative phase FDG-PET seems to be of limited value owing to unspecific tracer uptake. (orig.)

  9. Fluorine-18 fluorodeoxyglucose positron emission tomography in infectious bone diseases: results of histologically confirmed cases

    Kaelicke, T. [Dept. of Surgery, University of Bochum (Germany); Schmitz, A.; Schmitt, O. [Dept. of Orthopaedics, University of Bonn (Germany); Risse, J.H.; Biersack, H.J. [Dept. of Nuclear Medicine, University of Bonn (Germany); Arens, S.; Hansis, M. [Dept. of Trauma Surgery, University of Bonn (Germany); Keller, E. [Department of Radiology, University of Bonn (Germany); Gruenwald, F. [Department of Nuclear Medicine, University of Frankfurt/Main (Germany)

    2000-05-01

    The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in acute and chronic osteomyelitis and inflammatory spondylitis. The study population comprised 21 patients suspected of having acute or chronic osteomyelitis or inflammatory spondylitis. Fifteen of these patients subsequently underwent surgery. FDG-PET results were correlated with histopathological findings. The remaining six patients, who underwent conservative therapy, were excluded from any further evaluation due to the lack of histopathological data. The histopathological findings revealed osteomyelitis or inflammatory spondylitis in all 15 patients: seven patients had acute osteomyelitis and eight patients had chronic osteomyelitis or inflammatory spondylitis. FDG-PET yielded 15 true-positive results. The tracer uptake correlated with the histopathological findings in each case. Bone scintigraphy performed in 11 patients yielded ten true-positive results and one false-negative result. Follow-up carried out on two patients revealed normal or clearly reduced tracer uptake, which correlated with a normalisation of clinical data. In early postoperative follow-up it was impossible to differentiate between postsurgical reactive changes and further infection using FDG-PET. It is concluded that acute and chronic osteomyelitis of the peripheral as well as the central skeleton can be detected using FDG-PET. Osteomyelitis can be differentiated from soft tissue infection surrounding the bone. Unlike computed tomography and magnetic resonance imaging, FDG-PET is not affected by metal implants used for fixing fractures. FDG-PET demonstrated promising initial results with respect to treatment monitoring. Nevertheless, in the early postoperative phase FDG-PET seems to be of limited value owing to unspecific tracer uptake. (orig.)

  10. Prognostic value of 18-fluorodeoxyglucose positron emission tomography-computed tomography in resectable colorectal cancer

    Jang Eun Lee; Sang Woo Kim; Jin Su Kim; Kyu Yong Choi; Won Kyung Kang; Seong Taek Oh; Ie Ryung Yoo

    2012-01-01

    AIM:To assess the prognostic value of preoperative 18 fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) in patients with resectable colorectal cancer.METHODS:One hundred sixty-three patients with resectable colorectal cancer who underwent FDG-PET/CT before surgery were included.Patient data including pathologic stage at presentation,histology,treatment,disease-free survival and the maximum standardized uptake value (SUVmax) of the primary tumor on FDGPET/CT were retrospectively analyzed.Median follow up duration was 756 (range,419-1355).The primary end point was disease-free survival.RESULTS:Twenty-five of 163 patients (15.3%) had recurrences.The median SUVmax values of the recurrence and no-recurrence groups were 8.9 (range,5-24) and 8.2 (range,0-23,P =0.998).Receiver operating characteristic (ROC) curve analysis showed no significant association between SUVmax and recurrence (area under the curve =0.5,P =0.998,95%CI:0.389-0.611).Because a statistically significant value was not found,SUVmax was dichotomized at its median of 8.6.The disease-free survival curve was analyzed using the median SUVmax (8.6) as the cut off.Univariate and multivariate analysis did not provide evidence that disease-free survival rates for the subgroups defined by the median SUVmax were significantly different (P =0.52,P =0.25).CONCLUSION:Our study suggests that the high FDG uptake of primary mass in resectable colorectal cancer doesn't have a significant relationship with tumor recurrence and disease-free survival.

  11. Use of fluorine-18 fluorodeoxyglucose positron emission tomography in the detection of thymoma: a preliminary report

    Liu Renshyan [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China)]|[National Def. Medical Center, Taipei (Taiwan, Province of China); Yeh Shinhwa [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Huang Minhsiung [Div. of Thoracic Surgery, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Wang Liangshun [Div. of Thoracic Surgery, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Chu Leeshing [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China)]|[National Def. Medical Center, Taipei (Taiwan, Province of China); Chang Chenpei [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Chu Yumkung [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China); Wu Lingchi [National PET/Cyclotron Center and Dept. of Nuclear Medicine, Taipei Veterans General Hospital and National Yang-Ming Univ. School of Medicine, Taipei (Taiwan, Province of China)

    1995-12-01

    This study aimed to analyse the uptake patterns of fluorine-18 fluorodeoxyglucose (FDG) in thymomas of different stages. FDG positron emission tomography (PET) scan was performed in 12 patients suspected of having thymoma and in nine controls. Qualitative visual interpretation was used to detect the foci with FDG uptake higher than that of normal mediastinum. Tumour/lung ratio (TLR) was calculated from the counts of ROIs over the mass and over comparable normal lung tissue in thymoma patients. Mediastinum/lung ratio (MLR) was calculated from the counts of ROIs over the anterior mediastinum and lung in controls. The PET scan patterns of distribution of foci with FDG uptake and TLRs were correlated with the computed tomography (CT) of magnetic resonance imaging (MRI) findings, and staging of the thymomas. Thymectomy was performed in ten patients and thoracoscopy was done in two patients. The results revealed ten thymomas (two stage I tumours, two stage II, four stage III and two stage IV, according to the Masaoka classification), and two cases of thymic hyperplasia associated with myasthenia gravis. Myasthenia gravis was also noted in four thymoma patients. FDG studies showed (a) diffuse uptake in the widened anterior mediastinum in patients with thymic hyperplasia, (b) confined focal FDG uptake in the non-invasive or less invasive, stage I and II thymomas, and (c) multiple discrete foci of FDG uptake in the mediastinum and thoraci structures in stage III and IV advanced invasive thymomas. The thymomas had the highest TLRs, followed by the TLRs of thymic hyperplasia and the MLRs of control subjects. No significant difference was found between thymomas in different stages or between thymomas with and thymomas without myasthenia gravis. In comparison with CT and/or MRI, FDG/PET detected more lesions in patients with invasive thymomas and downgraded the staging of thymoma in four patients. (orig./MG)

  12. Use of fluorine-18 fluorodeoxyglucose positron emission tomography in the detection of thymoma: a preliminary report

    This study aimed to analyse the uptake patterns of fluorine-18 fluorodeoxyglucose (FDG) in thymomas of different stages. FDG positron emission tomography (PET) scan was performed in 12 patients suspected of having thymoma and in nine controls. Qualitative visual interpretation was used to detect the foci with FDG uptake higher than that of normal mediastinum. Tumour/lung ratio (TLR) was calculated from the counts of ROIs over the mass and over comparable normal lung tissue in thymoma patients. Mediastinum/lung ratio (MLR) was calculated from the counts of ROIs over the anterior mediastinum and lung in controls. The PET scan patterns of distribution of foci with FDG uptake and TLRs were correlated with the computed tomography (CT) of magnetic resonance imaging (MRI) findings, and staging of the thymomas. Thymectomy was performed in ten patients and thoracoscopy was done in two patients. The results revealed ten thymomas (two stage I tumours, two stage II, four stage III and two stage IV, according to the Masaoka classification), and two cases of thymic hyperplasia associated with myasthenia gravis. Myasthenia gravis was also noted in four thymoma patients. FDG studies showed (a) diffuse uptake in the widened anterior mediastinum in patients with thymic hyperplasia, (b) confined focal FDG uptake in the non-invasive or less invasive, stage I and II thymomas, and (c) multiple discrete foci of FDG uptake in the mediastinum and thoraci structures in stage III and IV advanced invasive thymomas. The thymomas had the highest TLRs, followed by the TLRs of thymic hyperplasia and the MLRs of control subjects. No significant difference was found between thymomas in different stages or between thymomas with and thymomas without myasthenia gravis. In comparison with CT and/or MRI, FDG/PET detected more lesions in patients with invasive thymomas and downgraded the staging of thymoma in four patients. (orig./MG)

  13. Differentiation of autoimmune pancreatitis from suspected pancreatic cancer by fluorine-18 fluorodeoxyglucose positron emission tomography

    Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been widely used for the diagnosis of pancreatic cancer. Because autoimmune pancreatitis is easily misdiagnosed as pancreatic cancer and can be tested for by FDG-PET analysis based on the presence of suspected pancreatic cancer, we attempted to clarify the differences in FDG-PET findings between the two conditions. We compared FDG-PET findings between 15 patients with autoimmune pancreatitis and 26 patients with pancreatic cancer. The findings were evaluated visually or semiquantitatively using the maximum standardized uptake value and the accumulation pattern of FDG. FDG uptake was found in all 15 patients with autoimmune pancreatitis, whereas it was found in 19 of 26 patients (73.1%) with pancreatic cancer. An accumulation pattern characterized by nodular shapes was significantly more frequent in pancreatic cancer, whereas a longitudinal shape indicated autoimmune pancreatitis. Heterogeneous accumulation was found in almost all cases of autoimmune pancreatitis, whereas homogeneous accumulation was found in pancreatic cancer. Significantly more cases of pancreatic cancer showed solitary localization, whereas multiple localization in the pancreas favored the presence of autoimmune pancreatitis. FDG uptake by the hilar lymph node was significantly more frequent in autoimmune pancreatitis than in pancreatic cancer, and uptake by the lachrymal gland, salivary gland, biliary duct, retroperitoneal space, and prostate were seen only in autoimmune pancreatitis. FDG-PET is a useful tool for differentiating autoimmune pancreatitis from suspected pancreatic cancer, if the accumulation pattern and extrapancreatic involvement are considered. IgG4 measurement and other current image tests can further confirm the diagnosis. (author)

  14. The value of fluorine-18 fluorodeoxyglucose positron emission tomography in patients with medullary thyroid cancer

    Brandt-Mainz, K.; Mueller, S.P.; Goerges, R.; Bockisch, A. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Essen, Essen (Germany); Saller, B. [Klinik und Poliklinik fuer Endokrinologie, Universitaetsklinikum Essen, Essen (Germany)

    2000-05-01

    The early detection of metastases from medullary thyroid cancer (MTC) is important because the only curative therapy consists in surgical removal of all tumour tissue. There is no single sensitive diagnostic imaging modality for the localization of all metastases in patients with MTC. Therefore, in many cases several imaging modalities (e.g. ultrasonography, magnetic resonance imaging, computerized tomography and scintigraphy using pentavalent technetium-99m dimercaptosuccinic acid, thallium-201 chloride, indium-111 pentetreotide, anti-CEA antibodies or metaiodobenzylguanidine) must be performed consecutively in patients with elevated calcitonin levels until the tumour is localized. In this prospective study, we investigated the value of fluorine-18 fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG PET) in the follow-up of patients with MTC. [{sup 18}F]FDG PET examinations of the neck and the chest were performed in 20 patients with elevated calcitonin levels or sonographic abnormalities in the neck. Positive [{sup 18}F]FDG findings were validated by histology, computerized tomography or selective venous catheterization. [{sup 18}F]FDG PET detected tumour in 13/17 patients (nine cases were validated by histology, four by computerized tomography). Five patients showed completely negative PET scans (of these cases, one was true-negative and four false-negative). One patient with [{sup 18}F]FDG accumulation in pulmonary lesions from silicosis and one patient with a neck lesion that was not subjected to histological validation had to be excluded. Considering all validated localizations, [{sup 18}F]FDG PET detected 12/14 tumour manifestations in the neck, 6/7 mediastinal metastases, 2/2 pulmonary metastases and 2/2 bone metastases. In two patients with elevated calcitonin levels, no diagnostic modality was able to localize a tumour. The sensitivity of [{sup 18}F]FDG PET in the follow-up of MTC was 76% (95% confidence interval 53%-94%); this is encouraging

  15. Are restrictions to behaviour of patients required following fluorine-18 fluorodeoxyglucose positron emission tomographic studies?

    The clinical use of positron emission tomography (PET) is expanding rapidly in most European countries. It is likely therefore that patients receiving the tracer fluorine-18 fluorodeoxyglucose (18FDG) will be discharged to come into contact with family members, members of the public and ward staff. There are few direct measurements on which to base any recommendations with regard to radiation protection, and so we have measured the dose rates from patients undergoing clinical PET examinations in our centre. Seventy-five patients who underwent whole-body and brain 18FDG PET examinations were studied. Dose rates were measured at 0.1, 0.5, 1.0 and 2.0 m from the mid thorax on leaving the department. The median administered activity was 323 MBq with a 95th percentile value of 360 MBq. The median dose rates measured at the four distances were 90.0, 35.0, 14.0 and 5.0 μSv h-1 (the median dose rates per unit administered activity at 2 h post injection were 0.31, 0.11, 0.04 and 0.02 μSv h-1 MBq-1). The corresponding 95th percentile values were 174.0, 69.0, 29.0 and 7.5 μSv h-1 (0.43, 0.2, 0.08 and 0.03 μSv h-1 MBq-1). A number of social situations were modelled and an annual dose limit of 1 mSv was used to determine whether restrictive behavioural advice was required. In the case of nursing staff on wards a value of 6 mSv was regarded as the annual limit, which translates to a daily limit of approximately 24 μSv. There is no need for restrictive advice for patients travelling by public or private transport when they leave the department 2 h after the administration of 18FDG. Similarly, there is no need for restrictive advice with regard to their contact with partners, work colleagues or children of any age, although it should be stressed that children should not accompany the patient to the scanning department. The only possible area of concern is in an oncology ward, where patients may be regularly referred for PET investigations and other high activity radionuclide

  16. Splenic and lymph nodal involvement in sarcoidosis mimicking lymphoma on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    Sarcoidosis is a multisystemic disease presenting with well-defined, bilateral, symmetric hilar and right paratracheal lymph node enlargement. Recently, fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) has been used to stage and detect occult site of active inflammation in sarcoidosis. F-18 FDG PET/CT has become a cornerstone imaging modality in the modern lymphoma management, which can present with generalized lymphadenopathy including mediastinal. We present a case series, which shows how sarcoidosis can be a “great mimic of lymphoma” on F-18 FDG PET/CT and how histopathology is essential in diagnosing sarcoidosis and ruling out lymphoma

  17. Impact of F-18-fluorodeoxyglucose positron emission tomography/computed tomography staging in newly diagnosed classical Hodgkin lymphoma

    El-Galaly, T. C.; Hutchings, M.; Juul Mylam, Karen;

    2014-01-01

    F-18-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is a highly accurate staging method in classical Hodgkin lymphoma (cHL). We retrospectively compared the staging results obtained in two large cohorts of patients with cHL diagnosed before (n = 324) and after (n = 406......) the introduction of PET/CT staging in a retrospective study. In PET/CT staged patients, stage I disease was less frequent (16% vs. 27%, p <0.001) while stage IV disease was more frequent (17% vs. 10%, p = 0.02). Imaging-detected skeletal involvement was recognized more often in PET/CT staged patients...... (17% vs. 2%, p <0.001), and the presence of focal skeletal PET/CT lesions was associated with higher risk of progression (hazard ratio [HR] 1.96, 95% confidence interval [CI]: 1.14-3.36). The German Hodgkin Study Group (GHSG) risk classification (early, intermediate, advanced disease) predicted...

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

    O Yaylali

    2014-01-01

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

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

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

    2016-01-01

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

  20. Evaluation of fluorine-18-fluorodeoxyglucose whole body positron emission tomography imaging in the clinical diagnosis of lung cancer

    In recent years the use of positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (FDG) has become a valuable tool in the detection of a variety of tumors including lung cancer. To determine its role in the diagnosis of patients with suspected lung cancer, we compared the results of FDG-PET with those of the other scintigraphic imaging techniques (67Ga-planar image, 201T1-SPECT and 99mTc-bone scintigraphy) used worldwide in patients with lung cancer. The analysis group consists of 178 patients, 159 malignant pulmonary diseases and 19 benign pulmonary diseases. FDG-PET was performed in 65 patients (51 malignant pulmonary diseases, 14 benign pulmonary diseases). FDG-PET had a sensitivity, specificity and accuracy of 98.0%, 78.6% and 93.8%, respectively, in detecting malignant pulmonary nodules. In N staging, sensitivity, specificity and accuracy were 66.7%, 81.3% and 76.0%, respectively. In M staging, the accuracy was 100%. Thus, FDG-PET imaging was more accurate than the other types of scintigraphic imaging. In our observations, whole-body 18FDG-PET images improved diagnostic accuracy in the evaluation of lung lesions and the staging of lung cancer. (author)

  1. The role of Fluorine-18-Fluorodeoxyglucose positron emission tomography in staging and restaging of patients with osteosarcoma

    The objective of this study is to systematically review the role of positron emission tomography (PET) and PET/computed tomography (PET/CT) with Fluorine-18-Fluorodeoxyglucose (FDG) in patients with osteosarcoma (OS). A comprehensive literature search of published studies through October 10th, 2012 in PubMed/MEDLINE, Embase and Scopus databases regarding whole-body FDG-PET and FDG-PET/CT in patients with OS was performed. We identified 13 studies including 289 patients with OS. With regard to the staging and restaging of OS, the diagnostic performance of FDG-PET and PET/CT seem to be high; FDG-PET and PET/CT seem to be superior to bone scintigraphy and conventional imaging methods in detecting bone metastases; conversely, spiral CT seems to be superior to FDG-PET in detecting pulmonary metastases from OS Metabolic imaging may provide additional information in the evaluation of OS patients. The combination of FDG-PET or FDG-PET/CT with conventional imaging methods seems to be a valuable tool in the staging and restaging of OS and may have a relevant impact on the treatment planning

  2. Fluor-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in malignant melanoma: Diagnostic comparison with conventional imaging methods

    Purpose: To assess the diagnostic value of fluor-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in screening for melanoma metastases. Material and Methods: The case records of 94 melanoma patients who had been examined by whole-body FDG-PET between 1995 and 1999 were evaluated retrospectively. Forty patients showed evidence of lymphogenous and 42 of hematogenous metastasis. The maximal interval between PET and the diagnostic procedure under comparison was 2 weeks. Confirmation of the findings was based on histology or the clinical or radiological course. Results: In 24 patients, all diagnostic examinations including CT had been performed within 2 weeks from PET. In no case did PET change the staging. In 13 patients, PET agreed with morphological diagnosis in the number of metastatically invaded organs. This included 3 patients without metastases. The estimated number of organs invaded by metastases was higher with PET in 5 patients and higher with morphological imaging techniques in 6 patients. Among the PET findings with higher or equivocal counts of organs with metastases there were 2 confirmed false-positive findings. Conclusion: In a selected patient population, FDG-PET was found to be inferior to CT for diagnosing lung and liver metastases. The supplementary use of FDG-PET is not generally of value once metastasis has been established

  3. Usefulness of Whole-Body Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography in Patients with Neurofibromatosis Type 1: A Systematic Review

    To systematically review the role of positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (FDG) in patients with neurofibromatosis type 1 (NF1). Methods. A comprehensive literature search of published studies regarding FDG-PET and PET/CT in patients with NF1 was performed. No beginning date limit and language restriction were used; the search was updated until December 2011. Only those studies or subsets in studies including whole-body FDG-PET or PET/CT scans performed in patients with NF1 were included. Results. We identified 12 studies including 352 NF1 patients. Qualitative evaluation was performed in about half of the studies and semiquantitative analysis, mainly based on different values of SUV cutoff, in the others. Most of the studies evaluated the role of FDG-PET for differentiating benign from malignant peripheral nerve sheath tumors (MPNSTs). Malignant lesions were detected with a sensitivity ranging between 100% and 89%, but with lower specificity, ranging between 100% and 72%. Moreover, FDG-PET seems to be an important imaging modality for predicting the progression to MPNST and the outcome in patients with MPNST. Two studies evaluated the role of FDG-PET in pediatric patients with NF1. Conclusions. FDG-PET and PET/CT are useful methods to identify malignant change in neurogenic tumors in NF1 and to discriminate malignant from benign neurogenic lesions

  4. Usefulness of Whole-Body Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography in Patients with Neurofibromatosis Type 1: A Systematic Review

    Giorgio Treglia

    2012-01-01

    Full Text Available Aim. To systematically review the role of positron emission tomography (PET with fluorine-18-fluorodeoxyglucose (FDG in patients with neurofibromatosis type 1 (NF1. Methods. A comprehensive literature search of published studies regarding FDG-PET and PET/CT in patients with NF1 was performed. No beginning date limit and language restriction were used; the search was updated until December 2011. Only those studies or subsets in studies including whole-body FDG-PET or PET/CT scans performed in patients with NF1 were included. Results. We identified 12 studies including 352 NF1 patients. Qualitative evaluation was performed in about half of the studies and semiquantitative analysis, mainly based on different values of SUV cutoff, in the others. Most of the studies evaluated the role of FDG-PET for differentiating benign from malignant peripheral nerve sheath tumors (MPNSTs. Malignant lesions were detected with a sensitivity ranging between 100% and 89%, but with lower specificity, ranging between 100% and 72%. Moreover, FDG-PET seems to be an important imaging modality for predicting the progression to MPNST and the outcome in patients with MPNST. Two studies evaluated the role of FDG-PET in pediatric patients with NF1. Conclusions. FDG-PET and PET/CT are useful methods to identify malignant change in neurogenic tumors in NF1 and to discriminate malignant from benign neurogenic lesions.

  5. Use of fluorine-18 fluorodeoxyglucose positron emission tomography in the detection of silent metastases from malignant melanoma

    Correct staging is crucial for the management and prognosis of patients with malignant melanoma. The aim of this prospective study was to compare staging by whole-body positron emission tomography using fluorine-18 fluorodeoxyglucose (18F-FDG) with staging by conventional methods. Thirty-eight patients with malignant melanoma of clinical stage II (local recurrence, in-transit and regional lymph node metastases) or III (metastases to other sites than in stage II) were included in the study. The results of the PET scans were compared with those obtained by clinical examination, computed tomography, ultrasound, radiography, and liver function tests and histology or clinical follow-up. With 18F-FDG PET we found for all foci a sensitivity of 97% and a specificity of 56%, compared with 62% and 22%, respectively, when using routine methods. For intra-abdominal foci, the sensitivity and specificity were 100% for both 18F-FDG PET and routine methods. Corresponding figures for pulmonary/intrathoracic foci were 100% and 33%, respectively. Of the patients included in this study, 34% would not have been staged correctly by conventional methods alone. We conclude from this study that 18F-FDG PET is a sensitive method superior to conventional methods for detecting widespread metastases from malignant melanoma. Mutilating surgery of no benefit can thereby be avoided. 18F-FDG PET is useful as a supplement to clinical examination in melanoma staging. (orig.)

  6. Kikuchi-Fujimoto disease mimicking tuberculous lymphadenitis or lymphoma on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    Abdul Rahim N

    2016-07-01

    Full Text Available Noraini Abdul Rahim,1 Abdul Jalil Nordin,2 Chiara Rusconi,3 Cristina Gabutti,3 Erika Ravelli,4 Claudio Rossetti5 1Diagnostic Imaging Department, Serdang Hospital, Selangor, 2Centre for Diagnostic Nuclear Imaging, University Putra Malaysia, Serdang, Malaysia; 3Department of Haematology, Ospedale Niguarda, Milan, 4Unit of Haematology, Valduce Hospital, Como, 5Department of Advance Technology (Nuclear Medicine, Ospedale Niguarda, Milan, Italy Abstract: Kikuchi-Fujimoto disease, also known as histiocytic lymphadenitis is a rare and benign disease characterized by regional cervical lymphadenopathy with fever of unknown origin, affecting mainly young women. We describe a case of a young Asian female who was initially misdiagnosed as having tuberculous lymphadenitis because of multiple lymphadenopathies with 18-fluorodeoxyglucose uptake on positron emission tomography/computed tomography. Final histologic diagnosis of Kikuchi-Fujimoto disease was made after excisional biopsy of the affected lymph node. The cervical lymphadenopathy has reduced in size and lung lesions disappeared after 2 months without specific treatment. Keywords: cervical lymphadenopathy, Kikuchi disease, PET/CT features

  7. Use of fluorine-18 fluorodeoxyglucose positron emission tomography in the detection of silent metastases from malignant melanoma

    Jakobsen, Annika Loft; Andersson, A P; Dahlstrøm, K; Rabøl, A; Jensen, M; Holm, S; Sørensen, S S; Drzewiecki, K T; Højgaard, L; Friberg, L

    2000-01-01

    Correct staging is crucial for the management and prognosis of patients with malignant melanoma. The aim of this prospective study was to compare staging by whole-body positron emission tomography using fluorine-18 fluorodeoxyglucose (18F-FDG) with staging by conventional methods. Thirty-eight pa...... method superior to conventional methods for detecting widespread metastases from malignant melanoma. Mutilating surgery of no benefit can thereby be avoided. 18F-FDG PET is useful as a supplement to clinical examination in melanoma staging.......-eight patients with malignant melanoma of clinical stage II (local recurrence, in-transit and regional lymph node metastases) or III (metastases to other sites than in stage II) were included in the study. The results of the PET scans were compared with those obtained by clinical examination, computed tomography......, ultrasound, radiography, and liver function tests and histology or clinical follow-up. With 18F-FDG PET we found for all foci a sensitivity of 97% and a specificity of 56%, compared with 62% and 22%, respectively, when using routine methods. For intra-abdominal foci, the sensitivity and specificity were 100...

  8. False-positive 18-fluorodeoxyglucose positron emission tomography–computed tomography (FDG PET/CT scans mimicking malignancies

    Zehra Yasar

    2015-02-01

    Full Text Available Aim 18-Fluorodeoxyglucose (FDG positron emission tomography–computed tomography (PET/CT is an imaging modality that is often used to help differentiate benign from malignant pulmonary lesions and it has been shown to be more efficacious than conventional chest computed tomography (CT. However, some benign lesions may also show increased metabolic activity which can lead to false-positive PET findings. We aim to illustrate false positive findings of PET scan that simulate lung cancer in a variety of diseases. Methods Patients referred to Yedikule Chest Diseases and Surgery Teaching and Research Hospital with increased FDG uptake for which histological results were available over a 2-year period (2013-2014 were reviewed. Seven patients with false-positive PET/CT findings were reported in this study. Results The majority of lesions showing increased metabolic activity were due to malignant diseases. However, increased 18 F-FDG uptake was also seen in benign lesions such as active pulmonary inflammation or infection, granulomatous processes and fibrotic lesions. Conclusion. The integration of clinical history, morphologic findings of lesions on the CT component, and metabolic activities of PET/CT scan can help reduce false interpretations. Interventional procedures.

  9. Use of fluorine-18 fluorodeoxyglucose positron emission tomography in the detection of silent metastases from malignant melanoma

    Eigtved, A. [Cyclotron Unit, Department of Clinical Physiology and Nuclear Medicine, Rigshospitalet, Copenhagen University Hospital (Denmark); PET and Cyclotron Unit, Rigshospitalet, Copenhagen University Hospital, Copenhagen (Denmark); Andersson, A.P.; Dahlstroem, K.; Drzewiecki, K.T. [Dept. of Plastic and Reconstructive Surgery, Rigshospitalet, Copenhagen University Hospital (Denmark); Raboel, A.; Jensen, M.; Holm, S.; Soerensen, S.S.; Hoejgaard, L.; Friberg, L. [Cyclotron Unit, Department of Clinical Physiology and Nuclear Medicine, Rigshospitalet, Copenhagen University Hospital (Denmark)

    2000-01-01

    Correct staging is crucial for the management and prognosis of patients with malignant melanoma. The aim of this prospective study was to compare staging by whole-body positron emission tomography using fluorine-18 fluorodeoxyglucose ({sup 18}F-FDG) with staging by conventional methods. Thirty-eight patients with malignant melanoma of clinical stage II (local recurrence, in-transit and regional lymph node metastases) or III (metastases to other sites than in stage II) were included in the study. The results of the PET scans were compared with those obtained by clinical examination, computed tomography, ultrasound, radiography, and liver function tests and histology or clinical follow-up. With {sup 18}F-FDG PET we found for all foci a sensitivity of 97% and a specificity of 56%, compared with 62% and 22%, respectively, when using routine methods. For intra-abdominal foci, the sensitivity and specificity were 100% for both {sup 18}F-FDG PET and routine methods. Corresponding figures for pulmonary/intrathoracic foci were 100% and 33%, respectively. Of the patients included in this study, 34% would not have been staged correctly by conventional methods alone. We conclude from this study that {sup 18}F-FDG PET is a sensitive method superior to conventional methods for detecting widespread metastases from malignant melanoma. Mutilating surgery of no benefit can thereby be avoided. {sup 18}F-FDG PET is useful as a supplement to clinical examination in melanoma staging. (orig.)

  10. F-18 fluorodeoxyglucose positron emission tomography 'super scan' in a patient of metastatic primitive neuroectodermal tumor of the kidney

    We report F-18 fluorodeoxyglucose (FDG) 'positron emission tomography (PET) super scan' akin to 'super scan' of conventional skeletal scintigraphy, in a rare case of primitive neuroectodermal tumor (PNET) of the kidney. A twelve year old male patient of metastatic PNET of the kidney was subjected to a 'true' whole body F-18 FDG PET scan including lower limbs and skull region as per the institution protocol. The images revealed extensive hypermetabolic areas corresponding to the computed tomography described renal, hepatic, and pancreatic lesions along with intense and non-uniform uptake in the marrows of axial and appendicular skeletal system. Interestingly, low background tracer concentration was observed along with very low F-18 FDG uptake in the brain, skeletal muscles of limb, mediastinum, and bowel. In view of these findings, the scan can be interpreted as 'PET super scan' due to its resemblance with the super scan of skeletal scintigraphy. A repeat F-18 FDG PET scan after chemotherapy revealed marked treatment response with disappearance of 'super scan' like pattern, reduction in number, size, metabolic activity of the lesions, and stimulated marrow sans the previously diseased portion. Though uncommon the reporting physician should be aware of PET super scan and its implications described in this case. (author)

  11. Myocardial uptake of F-18-fluorodeoxyglucose in whole body positron emission tomography studies

    The objective of this study was to correlate the degree of myocardial fluorodeoxyglucose (FDG) uptake in routine oncology positron emission tomography (PET) studies with fasting blood sugar level (FBSL), fasting period (FP) and age of the patient. Ninety-one patients (62 males and 29 females, age range: 7-78 years) with malignant diseases were included in the study. Whole body FDF-PET study was carried out after 1 h of intravenous injection of 296-370 MBq (8-10 mCi) F-18 FDG. Images were interpreted visually and patients were classified into four grades of myocardial uptake: No myocardial uptake = Grade 0; mild uptake = Grade 1; moderate uptake = Grade 2; and Marked uptake = Grade 3. Quantitative analysis was done by calculating Standardized uptake value (SUV max). Age, FBSL and FP were recorded. The degree of myocardial FDG uptake did not show significant correlation with FBSL, FP or age of the patient. Perhaps the reason lies elsewhere like insulin levels, medical treatments, fat metabolism, and myocardium status or some unexplored factors

  12. Optimal scan time for evaluating pancreatic disease with positron emission tomography using F-18-fluorodeoxyglucose

    Image interpretation in positron emission tomography (PET) using F-18-fluoro-2-deoxy-D-glucose (FDG) is usually performed for images obtained at 1 h postinjection (PI) of FDG, but it remains unknown whether this is the optimal time for imaging patients with pancreatic disease. The aim of this study was to assess the optimal scan time for FDG-PET for patients suspected of having pancreatic cancer. Forty-four patients with suspected pancreatic cancer underwent FDG-PET scans at both 1 h and 2 h PI. Tracer uptake in the pancreatic lesions and possible liver metastasis was interpreted qualitatively, using a 5-point grading system (0=normal, 1=probably normal, 2=equivocal, 3=probably abnormal, and 4=definitely abnormal) by 4 nuclear medicine physicians independently, who were blind to all clinical information. Detection performance with each image was compared using receiver operating characteristic (ROC) analysis. An average score of the 4 readers for each patient was also defined as consensus average index (CAI) and compared between the two images. ROC results indicated no significant differences in detection performance (Averaged areas under ROC curves of 1 h vs. 2 h were 0.92 vs. 0.90 for primary tumor, and 0.81 vs. 0.85 for liver metastases). There were no significant differences in CAIs between 1 h and 2 h PI images in interpreting primary tumor and positive liver metastases, but a significant difference was observed for cases without liver metastases (p<0.05). The certainty of excluding liver metastases was increased when the 2 h image was used, although ROC analysis did not establish a difference between 1 h and 2 h imaging for differentiating malignant and benign lesions in primary pancreatic cancer or its liver metastases. (author)

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

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

    2014-01-01

    Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous group of lymphoid proliferations caused by immunosuppression after solid organ or bone marrow transplantation. PTLD is categorized by early lesion, polymorphic PTLD and monomorphic PTLD. Fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) scans have clinical significance in the evaluation of PTLD following renal transplantation. We report imaging findings of a monomorphic non-H...

  14. Rare case of isolated splenic metastases from gastric cancer detected with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography

    We report a rare case of isolated splenic metastasis from gastric cancer detected with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT). A 55-year-old man with gastric cancer 1 year post surgery, evaluated with PET/CT showed focal, intense uptake in the spleen, with no other abnormal findings. On splenectomy, the lesion was confirmed as metastasis from gastric cancer pathologically. (author)

  15. Feasibility of a short acquisition protocol for whole-body positron emission tomography with fluorine-18 fluorodeoxyglucose

    The conventional protocol for whole-body positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) requires a total acquisition time of 40-60 min, which is inconvenient for many oncological patients owing to fatigue and discomfort. This study examined the feasibility of a short protocol for whole-body PET. A phantom containing six ''hot'' spheres of gradually increasing diameter (10-38 mm) was imaged using a dedicated PET scanner for 20, 40, 60, 80, 120 and 600 s at various count rates. Thirty-four patients with various neoplasms underwent whole-body emission scans for 1 min per bed position 1 h after intravenous injection of 370 MBq of FDG (short protocol). A standard simultaneous transmission-emission acquisition for 10 min per bed position was performed thereafter. The images were reconstructed using an iterative algorithm. At a count rate of 40 kcps, which is close to the average count rate obtained in a whole-body FDG PET study, the 60-s image visualised five spheres, of which the smallest was 13 mm in size. Despite the better image quality, lesion detection was not improved in images acquired for more than 60 s (80-600 s). Only three of the six spheres could be detected in images acquired for less than 60 s. In the patient study, the standard protocol visualised 120 tumour lesions, of which 93 (78%) could be detected using the short protocol. Among the non-visualised lesions, 22 (82%) were ≤1.5 cm in size and 17 (63%) were lymph nodes. It is concluded that the proposed short protocol for whole-body FDG PET has a reasonably high detection rate and may be suitable for patients who are unable to undergo scanning for a prolonged period. It may also be useful as a pre-scan guide before a standard whole-body acquisition. (orig.)

  16. F-18 fluorodeoxyglucose positron emission tomography in the mediastinal nodal staging of non-small cell lung carcinoma

    Berlangieri, S.U.; Scott, A.M.; Knight, S.; Fitt, G.J.; Hess, E.M.; Pathmaraj, K.; Hennessy, O.F.; Tochon-Danguy, H.J.; Chan, J.G.; Egan, G.F.; Sinclair, R.A.; Clarke, C.P.; McKay, W.J. [Austin and Repatriation Medical Centre, Heidelberg, VIC (Australia). Departments of Nuclear Medicine and Centre for PET, Thoracic Surgery, Radiology and Pathology]|[St Vincents Hospital, Fitzroy, VIC (Australia). Department of Radiology

    1998-06-01

    Full text: Positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG), as a metabolic tumour marker, has been proposed for staging of oncological disease. To determine its role in the mediastinal staging of lung cancer, a prospective comparison of FDG PET with surgery was performed in patients with suspected non-small cell lung carcinoma. The analysis group consists of 70 patients, 49 men and 21 women, mean age 64 yrs (range 41-83 yrs). The PET study was acquired on a Siemens 951/31R scanner over 3 bed positions, 45 minutes following 400MBq FDG. The emission scan was attenuation corrected using measured transmission data. The FDG PET were interpreted by a nuclear physician blinded to the clinical data and the results of the patients` CT scan. On PET, nodes were graded qualitatively on a 5 point scale with scores 4 or greater, positive for tumour involvement. Surgical specimens were obtained in all patients by thoracotomy or mediastinoscopy. The PET metabolic studies and pathology were mapped according to the American Thoracic Society nodal classification resulting in a total of 277 nodal stations evaluated. The PET studies analysed N2 or N3 tumour involvement by nodal station in comparison to histology of pathological specimens or direct visual assessment of the nodal stations at surgery. All patients had proven non-small cell lung carcinoma, except two, in whom, a tissue confirmation of the suspected diagnosis was not attained. PET excluded tumour in 237 of 246 nodal stations (specificity 96%). PET correctly identified 23 of 31 nodal stations with disease (sensitivity 74%). PET correctly staged 260 of 277 nodal stations (accuracy 94%) for disease. FDG PET is an accurate non-invasive functional imaging modality for the mediastinal staging of non-small cell lung cancer and has an important clinical role in the preoperative staging of lung cancer patients.

  17. F-18 fluorodeoxyglucose positron emission tomography in the mediastinal nodal staging of non-small cell lung carcinoma

    Full text: Positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG), as a metabolic tumour marker, has been proposed for staging of oncological disease. To determine its role in the mediastinal staging of lung cancer, a prospective comparison of FDG PET with surgery was performed in patients with suspected non-small cell lung carcinoma. The analysis group consists of 70 patients, 49 men and 21 women, mean age 64 yrs (range 41-83 yrs). The PET study was acquired on a Siemens 951/31R scanner over 3 bed positions, 45 minutes following 400MBq FDG. The emission scan was attenuation corrected using measured transmission data. The FDG PET were interpreted by a nuclear physician blinded to the clinical data and the results of the patients' CT scan. On PET, nodes were graded qualitatively on a 5 point scale with scores 4 or greater, positive for tumour involvement. Surgical specimens were obtained in all patients by thoracotomy or mediastinoscopy. The PET metabolic studies and pathology were mapped according to the American Thoracic Society nodal classification resulting in a total of 277 nodal stations evaluated. The PET studies analysed N2 or N3 tumour involvement by nodal station in comparison to histology of pathological specimens or direct visual assessment of the nodal stations at surgery. All patients had proven non-small cell lung carcinoma, except two, in whom, a tissue confirmation of the suspected diagnosis was not attained. PET excluded tumour in 237 of 246 nodal stations (specificity 96%). PET correctly identified 23 of 31 nodal stations with disease (sensitivity 74%). PET correctly staged 260 of 277 nodal stations (accuracy 94%) for disease. FDG PET is an accurate non-invasive functional imaging modality for the mediastinal staging of non-small cell lung cancer and has an important clinical role in the preoperative staging of lung cancer patients

  18. Fluorine-18 fluorodeoxyglucose positron emission tomography in the differential diagnosis of pancreatic carcinoma: a report of 106 cases

    The aim of this study was to evaluate fluorine-18 fluorodeoxyglucose positron emission tomography ([18F[FDG PET) as a tool for the differential diagnosis of pancreatic carcinoma while taking into account serum glucose level. A group of 106 patients with unclear pancreatic masses were recruited for the study. PET was performed following intravenous administration of an average of 190 MBq [18F[FDG. Focally increased glucose utilisation was used as the criterion of malignancy. In addition, the ''standardised uptake value'' (SUV) was determined 45 min after injection. Carcinoma of the pancreas was demonstrated histologically in 74 cases, and chronic pancreatitis in 32 cases. Employing visual evaluation, 63 of the 74 (85%) pancreatic carcinomas were identified by PET. In 27 of the 32 cases (84%) of chronic pancreatitis it was possible to exclude malignancy. False-negative results (n=11) were obtained mostly in patients with raised serum glucose levels (10 out of 11), and false-positives (n=5) in patients with inflammatory processes of the pancreas. Thus PET showed an overall sensitivity of 85%, a specificity of 84%, a negative predictive value of 71%, and a positive predictive value of 93%. In a subgroup of patients with normal serum glucose levels (n=72), the results were 98%, 84%, 96% and 93%, respectively. Quantitative assessment yielded a mean SUV of 6.4±3.6 for pancreatic carcinoma as against a value of 3.6±1.7 for chronic pancreatitis (P<0.001), without increasing the diagnostic accuracy. This shows PET to be of value in assessing unclear pancreatic masses. The diagnostic accuracy of PET examinations is very dependent on serum glucose levels. (orig.). With 2 figs., 3 tabs

  19. Cerebral interregional correlations of associative language processing: a positron emission tomography activation study using fluorine-18 fluorodeoxyglucose

    Even though there have been numerous positron emission tomography (PET) activation studies on the perfusional and metabolic bases of language processing, little is known about the intracerebral functional network of language and cognitive processes. It was the aim of this study to investigate the cerebral interregional correlations during voluntary word association versus word repetition in healthy subjects to gain insight into the functional connectivity of associative speech processing. Due to individual variability in functional anatomy, the study protocol was designed as an averaged single-subject study. Eight healthy volunteers performed a verbal association task during fluorine-18 fluorodeoxyglucose (18F-FDG) PET scanning. Two different tasks were performed in randomized order: (a) word repetition (after auditory presentation of nouns) as a control condition, and (b) word association (after auditory presentation of nouns) as a specific semantic activation. The regional metabolic rate of glucose (rMRGlu) was calculated after brain regionalization [112 regions of interest on individual 3D flash magnetic resonance imaging (MRI)] and PET/MRI realignment. Statistical analysis was performed for comparison of association and repetition and for calculation of interregional correlation coefficients during both tasks. Compared with word repetition, word association was associated with significant increases in rMRGlu in the left prefrontal cortex, the left frontal operculum (Broca's area) and the left insula, indicating involvement of these areas in associative language processing. Decreased rMRGlu was found in the left posterior cingulum during word association. During word repetition, highly significant negative correlations were found between the left prefrontal cortex, the contralateral cortex areas and the ipsilateral posterior cingulum. These negative correlations were almost completely eliminated during the association task, suggesting a functional decoupling of

  20. Cerebral interregional correlations of associative language processing: a positron emission tomography activation study using fluorine-18 fluorodeoxyglucose

    Schreckenberger, M.; Sabri, O.; Arning, C.; Schulz, G.; Tuttass, T.; Wagenknecht, G.; Kaiser, H.J.; Buell, U. [Department of Nuclear Medicine, Aachen University of Technology, Aachen (Germany); Gouzoulis-Mayfrank, E.; Sass, H. [Department of Psychiatry, Aachen University of Technology, Aachen (Germany)

    1998-11-01

    Even though there have been numerous positron emission tomography (PET) activation studies on the perfusional and metabolic bases of language processing, little is known about the intracerebral functional network of language and cognitive processes. It was the aim of this study to investigate the cerebral interregional correlations during voluntary word association versus word repetition in healthy subjects to gain insight into the functional connectivity of associative speech processing. Due to individual variability in functional anatomy, the study protocol was designed as an averaged single-subject study. Eight healthy volunteers performed a verbal association task during fluorine-18 fluorodeoxyglucose ({sup 18}F-FDG) PET scanning. Two different tasks were performed in randomized order: (a) word repetition (after auditory presentation of nouns) as a control condition, and (b) word association (after auditory presentation of nouns) as a specific semantic activation. The regional metabolic rate of glucose (rMRGlu) was calculated after brain regionalization [112 regions of interest on individual 3D flash magnetic resonance imaging (MRI)] and PET/MRI realignment. Statistical analysis was performed for comparison of association and repetition and for calculation of interregional correlation coefficients during both tasks. Compared with word repetition, word association was associated with significant increases in rMRGlu in the left prefrontal cortex, the left frontal operculum (Broca`s area) and the left insula, indicating involvement of these areas in associative language processing. Decreased rMRGlu was found in the left posterior cingulum during word association. During word repetition, highly significant negative correlations were found between the left prefrontal cortex, the contralateral cortex areas and the ipsilateral posterior cingulum. These negative correlations were almost completely eliminated during the association task, suggesting a functional

  1. Fluorine-18 fluorodeoxyglucose positron emission tomography in the differential diagnosis of pancreatic carcinoma: a report of 106 cases

    Zimny, M. [Department of Nuclear Medicine, Aachen University of Technology (Germany); Bares, R. [Department of Nuclear Medicine, Aachen University of Technology (Germany); Fass, J. [Department of Surgery, Aachen University of Technology (Germany); Adam, G. [Department of Diagnostic Radiology, Aachen University of Technology (Germany); Cremerius, U. [Department of Nuclear Medicine, Aachen University of Technology (Germany); Dohmen, B. [Department of Nuclear Medicine, Aachen University of Technology (Germany); Klever, P. [Department of Surgery, Aachen University of Technology (Germany); Sabri, O. [Department of Nuclear Medicine, Aachen University of Technology (Germany); Schumpelick, V. [Department of Surgery, Aachen University of Technology (Germany); Buell, U. [Department of Nuclear Medicine, Aachen University of Technology (Germany)

    1997-06-10

    The aim of this study was to evaluate fluorine-18 fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG PET) as a tool for the differential diagnosis of pancreatic carcinoma while taking into account serum glucose level. A group of 106 patients with unclear pancreatic masses were recruited for the study. PET was performed following intravenous administration of an average of 190 MBq [{sup 18}F]FDG. Focally increased glucose utilisation was used as the criterion of malignancy. In addition, the ``standardised uptake value`` (SUV) was determined 45 min after injection. Carcinoma of the pancreas was demonstrated histologically in 74 cases, and chronic pancreatitis in 32 cases. Employing visual evaluation, 63 of the 74 (85%) pancreatic carcinomas were identified by PET. In 27 of the 32 cases (84%) of chronic pancreatitis it was possible to exclude malignancy. False-negative results (n=11) were obtained mostly in patients with raised serum glucose levels (10 out of 11), and false-positives (n=5) in patients with inflammatory processes of the pancreas. Thus PET showed an overall sensitivity of 85%, a specificity of 84%, a negative predictive value of 71%, and a positive predictive value of 93%. In a subgroup of patients with normal serum glucose levels (n=72), the results were 98%, 84%, 96% and 93%, respectively. Quantitative assessment yielded a mean SUV of 6.4{+-}3.6 for pancreatic carcinoma as against a value of 3.6{+-}1.7 for chronic pancreatitis (P<0.001), without increasing the diagnostic accuracy. This shows PET to be of value in assessing unclear pancreatic masses. The diagnostic accuracy of PET examinations is very dependent on serum glucose levels. (orig.). With 2 figs., 3 tabs.

  2. F-18 fluorodeoxyglucose positron emission tomography in patients with nonsmall cell lung carcinoma and indeterminate adrenal masses

    Full text: Accurate characterisation of adrenal masses in patients presenting with nonsmall cell lung carcinoma (NSCLC) is imperative in identifying patients for curative resection. Computed tomography (CT) is inaccurate in distinguishing benign from malignant adrenal masses and patients frequently requite percutaneous biopsy . F- 18 fluorodeoxyglucose positron emission tomography (FDG PET) differentiates benign from malignant tissue on the basis of the tumour's metabolic activity. The aim of this study was to evaluate the potential role of FDG PET in patients with NSCLC with indeterminate adrenal masses. We retrospectively reviewed patients undergoing FDG PET for preoperative mediastinal staging who also had adrenal masses on CT. Ten patients, 7 men and 3 women, (age: 48-74 yrs) were identified with a total of 13 adrenal masses from 1.5 to 6 cm in diameter. A definitive diagnosis was available in 10 of 13 adrenal masses; percutaneous biopsy and histology in 8 and serial CT follow up in 2 patients. Following the intravenous administration of 370 MBq FDG and a 45 minute uptake period, emission tomographic images of the thorax and upper abdomen were acquired on a Siemens 951/31R body scanner (FWHM 6.5cm) in all patients. PET and CT clinical reports were correlated with histology from percutaneous biopsy of the adrenal masses or with adrenal gland appearances at serial CT. Of 10 adrenal masses, 5 were proven malignant, 4 on histology and on serial CT. Five adrenal masses were proven benign, 4 on histology and 1on serial CT. Of the 5 malignant lesions, FDG PET was true positive in 4/5 cases with one false negative in a patient with mild adrenal enlargement. The presence of pelvicalyceal urinary activity may have masked adrenal uptake in this case. Of five benign lesions, FDG PET was true negative in 5/5 cases. FDG PET correctly characterised 9 of 10 adrenal masses into benign or malignant, resulting in an overall accuracy of 90%. It is concluded that small adrenal

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

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

  4. F-18 fluorodeoxyglucose positron emission tomography “super scan” in a patient of metastatic primitive neuroectodermal tumor of the kidney

    Malhotra, Gaurav; Swami, Archana; Shah, Pinky; Mittal, Neha; Gandhi, Sunny J; Tiwari, BP; Jatale, Praful V; Asopa, Ramesh V

    2012-01-01

    We report F-18 fluorodeoxyglucose (FDG) “positron emission tomography (PET) super scan” akin to “super scan” of conventional skeletal scintigraphy, in a rare case of primitive neuroectodermal tumor (PNET) of the kidney. A twelve year old male patient of metastatic PNET of the kidney was subjected to a “true” whole body F-18 FDG PET scan including lower limbs and skull region as per the institution protocol. The images revealed extensive hypermetabolic areas corresponding to the computed tomog...

  5. Post transplant urinary tract infection in Autosomal dominant polycystic kidney disease a perpetual diagnostic dilema - 18-fluorodeoxyglucose - Positron emission computerized tomography - A valuable tool

    Urinary tract infection (UTI) is the most common infection contracted by renal allograft recipients. In patients of autosomal dominant polycystic kidney disease (ADPKD), cyst infection presents a complex diagnostic and therapeutic challenge especially in the post transplant period. Accurate diagnosis forms the cornerstone in salvaging the graft from potentially catastrophic outcome. We describe a case of xanthogranulomatous pyelonephritis (XPN) in the native kidney in a patient of post transplant ADPKD which presented as frequently relapsing UTI with graft dysfunction where in accurate diagnosis was made possible with the aid of 18-fluorodeoxyglucose (FDG) - Positron emission computerized tomography (PET/CT)

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

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

    2014-07-01

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

  7. Spindle cell sarcoma of pulmonary artery mimicking thromboembolism with lung metastasis detected in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    Pulmonary artery sarcoma (PAS), although rare, must be considered in the differential diagnosis of pulmonary thromboembolism (PTE). This tumor is highly malignant and the prognosis is very poor. As much as the standardized uptake values (SUVs) at fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) have helped in differentiating between benign and malignant tumors, visualization of a low-attenuation filling defect within a pulmonary artery on contrast-enhanced chest computed tomography (CT) can be suggestive of a malignancy, such as PAS, if the lesion shows high FDG uptake at PET. We present a case of PAS that showed high FDG uptake on integrated FDG PET/CT and with lung metastasis. Patient underwent endoscopic bronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA), which confirmed spindle cell sarcoma

  8. Preserved Glucose Metabolism of Deep Cerebellar Nuclei in a Case of Multiple System Atrophy with Predominant Cerebellar Ataxia: F-18 Fluorodeoxyglucose Positron Emission Tomography Study

    Oh Dae Kwon

    2010-10-01

    Full Text Available The cerebellar glucose metabolism of multiple system atrophy with predominant cerebellar ataxia (MSA-C is known to be decreased but is not defined among areas of cerebellum. We encountered a 54-year-old man who developed dizziness and progressive ataxia followed by urinary incontinence and orthostatic hypotension, all of those symptoms progressed relentlessly and the symptoms responded poorly to levodopa therapy. Visual analysis and statistical parametric mapping analysis of F-18 fluorodeoxyglucose positron emission tomography showed hypometabolism of both cerebellar hemisphere, severe at cortical area, and pons. There was clear sparing of deep cerebellar nuclei. Our report, as we know, shows the first case of preserved glucose metabolism of deep cerebellar nuclei relative to cerebellar cortex in an MSA-C patient.

  9. Subcutaneous fatty tissue metastasis from renal cell carcinoma detected with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging

    A patient who had undergone left radical nephrectomy 11 years ago for renal cell carcinoma (RCC) was referred to our clinic for restaging. Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (18F-FDG PET/CT) showed hypometabolic area in left frontal region of the brain and increased FDG uptake in the subcutaneous fatty tissues of the right thigh. Histopathological examination of the biopsy material from the left frontal region and right gluteal region revealed metastasis of clear cell type RCC. Seven months later, a magnetic resonance imaging (MRI) of right cruris showed a contrast-enhancing lesion with a diameter of 3.5 cm, located at the subcutaneous area of posterior part of right cruris. A concomitant 18F-FDG PET/CT detected an increased FDG uptake focus in the proximal third of right cruris adjacent to the muscle planes and this finding was consistent with metastasis of RCC. (author)

  10. Incidental detection of clinically occult follicle stimulating hormone secreting pituitary adenoma on whole body 18-fluorodeoxyglucose positron emission tomography-computed tomography

    A 73-year-old man, known case of Hodgkin's lymphoma, underwent 18-Fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET-CT) for post-chemotherapy evaluation of the disease status. The scan revealed focal increased FDG uptake in pituitary fossa. The CT images showed homogeneously enhancing pituitary lesion causing expansion of the sella. A possibility for the presence of pituitary adenoma was raised in the report. Hormonal assay of the patient showed raised follicle stimulating hormone (FSH) level of 18 IU/ml (normal range for males up to 5 IU/ml). All the other pituitary hormones were within the normal range. Nuclear magnetic resonance (NMR) imaging of brain showed a pituitary lesion with expanded sella pushing the optic chiasma superiorly. NMR findings confirmed the presence of pituitary macroadenoma. A final diagnosis of FSH secreting pituitary macroadenoma was made. (author)

  11. Isolated thymic Langerhans cell histiocytosis discovered on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT)

    Turpin, Sophie [CHU Sainte-Justine, Nuclear Medicine, Montreal (Canada); Carret, Anne-Sophie [CHU Sainte-Justine, Hemato-Oncology, Montreal (Canada); Dubois, Josee [CHU Sainte-Justine, Radiology, Montreal (Canada); Buteau, Chantal [CHU Sainte-Justine, Infectious Diseases, Montreal (Canada); Patey, Natalie [CHU Sainte-Justine, Pathology, Montreal (Canada)

    2015-11-15

    The thymic infiltration in young patients with multisystemic Langerhans cell histiocytosis and its radiologic features are well known. However, isolated thymic disease has seldom been reported in the literature. We report the case of a 10-month-old child admitted for fever of unknown origin. Whole-body F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) was performed to identify a focus of infection. It demonstrated an unusual aspect of the thymus, which led to further investigation and revealed isolated infiltration of the thymus by Langerhans cell histiocytosis. The patient was treated accordingly and is now disease free. As evaluation of Langerhans cell histiocytosis patients with F-18 FDG PET/CT is becoming more frequent, it is important to be aware of the scintigraphical characteristics of thymic Langerhans cell histiocytosis. (orig.)

  12. Isolated thymic Langerhans cell histiocytosis discovered on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT)

    The thymic infiltration in young patients with multisystemic Langerhans cell histiocytosis and its radiologic features are well known. However, isolated thymic disease has seldom been reported in the literature. We report the case of a 10-month-old child admitted for fever of unknown origin. Whole-body F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) was performed to identify a focus of infection. It demonstrated an unusual aspect of the thymus, which led to further investigation and revealed isolated infiltration of the thymus by Langerhans cell histiocytosis. The patient was treated accordingly and is now disease free. As evaluation of Langerhans cell histiocytosis patients with F-18 FDG PET/CT is becoming more frequent, it is important to be aware of the scintigraphical characteristics of thymic Langerhans cell histiocytosis. (orig.)

  13. Role of fluorine-18 fluorodeoxyglucose positron emission tomography in a case of renal cell carcinoma to differentiate tumor thrombus from bland thrombus

    Tumor thrombus is a rare complication of many solid tumors. We present a case of renal cell carcinoma whose baseline contrast-enhanced computerized tomography (CT) revealed an heterogeneously enhancing mass in the upper half of right kidney with tumor thrombus in the right renal vein extending to suprarenal inferior vena cava (IVC), crossing the cavoatrial junction and reaching up to the right atrium (Grade IV). Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT imaging revealed large irregular right renal mass, hypermetabolic tumor thrombus extending from the right renal vein to suprarenal IVC reaching up to the right atrium. There was no FDG uptake noted in the infrarenal IVC and bilateral iliofemoral venous thrombi. Thus, 18F-FDG PET/CT was not only helpful in the staging, but was also helpful in differentiating tumor thrombus from bland thrombus in our patient

  14. Impact of 18-fluorodeoxyglucose positron emission tomography on computed tomography defined target volumes in radiation treatment planning of esophageal cancer : reduction in geographic misses with equal inter-observer variability

    Schreurs, Liesbeth; Busz, D. M.; Paardekooper, G. M. R. M.; Beukema, J. C.; Jager, P. L.; Van der Jagt, E. J.; van Dam, G. M.; Groen, H.; Plukker, J. Th. M.; Langendijk, J. A.

    2010-01-01

    P>Target volume definition in modern radiotherapy is based on planning computed tomography (CT). So far, 18-fluorodeoxyglucose positron emission tomography (FDG-PET) has not been included in planning modality in volume definition of esophageal cancer. This study evaluates fusion of FDG-PET and CT in

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

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

    2016-01-01

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

  16. Multiple pulmonary sclerosing hemangiomas (pneumocytoma) mimicking lung metastasis detected in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    Pulmonary sclerosing hemangioma (PSH), or the alternative name of “sclerosing pneumocytoma,” is a rare benign neoplasm. PSH is often asymptomatic and presents as a solitary or multiple pulmonary nodules on radiologic imaging studies. Few articles have been reported to describe the fluorodeoxyglucose positron emission tomography (FDG PET) findings about PSH. The authors describe an interesting but uncommonly encountered cause of false positive FDG PET scan in the thorax in a 25-year-old woman, a known case of arteriovenous malformation of oral cavity who underwent embolization and presented with incidental detection of bilateral lung nodules. She is asymptomatic and is on follow-up

  17. Fluorine-18 fluorodeoxyglucose positron emission tomography in the staging and follow-up of lymphoma: is it time to shift gears?

    Positron emission tomography (PET) imaging has become a very useful technique for staging and monitoring therapy response in lymphoma, providing unique information about the biological behavior of disease. Increased fluorine-18 fluorodeoxyglucose (FDG) uptake in lymphoma is based on elevated glycolysis and longer residence time of FDG in malignant cells compared with most normal tissues. The metabolic information provided by this technique suggests that FDG-PET may be more sensitive than the anatomical imaging modalities. Computed tomography (CT) is the principal imaging modality for the staging and restaging of lymphoma. Nonetheless, this technique has significant shortcomings, particularly in the post-therapy setting. Gallium-67 scintigraphy has played an important role in monitoring response to therapy and follow-up of patients; however, the sensitivity of 67Ga depends on the subtype of lymphoma and the size and location of disease. Published results strongly indicate that FDG-PET is superior to 67Ga imaging and may be equal or superior to CT for the detection of nodal as well as extranodal involvement in lymphoma. (orig.)

  18. Role of fluorine-18-fluorodeoxyglucose positron emission tomography-computed tomography in management of pulmonary mucoepidermoid carcinomas and review of literature.

    Krishnamurthy, Arvind; Ramshankar, Vijayalakshmi; Majhi, Urmila

    2016-01-01

    Pulmonary mucoepidermoid carcinoma (PMEC) is a rare tumor of bronchial gland origin with a striking resemblance to MEC of the salivary glands. The World Health Organization classifies PMECs as "salivary gland type" tumors along with pulmonary adenoid cystic carcinomas and epimyoepithelial lung carcinomas. Their description in literature is largely limited to a few case series/case reports. Further, the experience of imaging in these tumors with fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography ( (18)F-FDG PET-CT) is also limited and evolving largely due to rarity of PMEC. We recently managed an interesting case of a PMEC and reviewed the literature surrounding this rare tumor with an emphasis on the role of (18)F-FDG PET-CT in its management. An (18)F-FDG PET-CT appears to be a useful imaging modality for predicting the tumor grade of patients with PMECs; further, there is emerging data to suggest the role of (18)F-FDG PET-CT for predicting the long-term prognosis of patients with PMEC. PMID:27095092

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

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

    2016-02-01

    The purpose of this study was to estimate average radiation exposure from (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) examinations and to analyze possible factors affecting the radiation dose. A nation-wide questionnaire survey was conducted involving all institutions that operate PET/CT scanners in Korea. From the response, radiation doses from injected FDG and CT examination were calculated. A total of 105 PET/CT scanners in 73 institutions were included in the analysis (response rate of 62.4%). The average FDG injected activity was 310 ± 77 MBq and 5.11 ± 1.19 MBq/kg. The average effective dose from FDG was estimated to be 5.89 ± 1.46 mSv. The average CT dose index and dose-length product were 4.60 ± 2.47 mGy and 429.2 ± 227.6 mGy∙cm, which corresponded to 6.26 ± 3.06 mSv. The radiation doses from FDG and CT were significantly lower in case of newer scanners than older ones (P related to low radiation dose (P < 0.001). In conclusion, the average radiation dose from FDG PET/CT is estimated to be 12.2 mSv. The radiation dose from FDG PET/CT is reduced with more recent scanners equipped with image-enhancing algorithms. PMID:26908992

  20. Feasibility of optimizing the dose distribution in lung tumors using fluorine-18-fluorodeoxyglucose positron emission tomography and single photon emission computed tomography guided dose prescriptions

    The information provided by functional images may be used to guide radiotherapy planning by identifying regions that require higher radiation dose. In this work we investigate the dosimetric feasibility of delivering dose to lung tumors in proportion to the fluorine-18-fluorodeoxyglucose activity distribution from positron emission tomography (FDG-PET). The rationale for delivering dose in proportion to the tumor FDG-PET activity distribution is based on studies showing that FDG uptake is correlated to tumor cell proliferation rate, which is shown to imply that this dose delivery strategy is theoretically capable of providing the same duration of local control at all voxels in tumor. Target dose delivery was constrained by single photon emission computed tomography (SPECT) maps of normal lung perfusion, which restricted irradiation of highly perfused lung and imposed dose-function constraints. Dose-volume constraints were imposed on all other critical structures. All dose-volume/function constraints were considered to be soft, i.e., critical structure doses corresponding to volume/function constraint levels were minimized while satisfying the target prescription, thus permitting critical structure doses to minimally exceed dose constraint levels. An intensity modulation optimization methodology was developed to deliver this radiation, and applied to two lung cancer patients. Dosimetric feasibility was assessed by comparing spatially normalized dose-volume histograms from the nonuniform dose prescription (FDG-PET proportional) to those from a uniform dose prescription with equivalent tumor integral dose. In both patients, the optimization was capable of delivering the nonuniform target prescription with the same ease as the uniform target prescription, despite SPECT restrictions that effectively diverted dose from high to low perfused normal lung. In one patient, both prescriptions incurred similar critical structure dosages, below dose-volume/function limits

  1. Age- and Sex-Associated Changes in Cerebral Glucose Metabolism in Normal Healthy Subjects: Statistical Parametric Mapping Analysis of F-18 Fluorodeoxyglucose Brain Positron Emission Tomography

    Background: The age- and sex-associated changes of brain development are unclear and controversial. Several previous studies showed conflicting results of a specific pattern of cerebral glucose metabolism or no differences of cerebral glucose metabolism in association with normal aging process and sex. Purpose: To investigate the effects of age and sex on changes in cerebral glucose metabolism in healthy subjects using fluorine-18 fluorodeoxyglucose (F-18 FDG) brain positron emission tomography (PET) and statistical parametric mapping (SPM) analysis. Material and Methods: Seventy-eight healthy subjects (32 males, mean age 46.6±18.2 years; 46 females, mean age 40.6±19.8 years) underwent F-18 FDG brain PET. Using SPM, age- and sex-associated changes in cerebral glucose metabolism were investigated. Results: In males, a negative correlation existed in several gray matter areas, including the right temporopolar (Brodmann area [BA] 38), right orbitofrontal (BA 47), left orbitofrontal gyrus (BA 10), left dorsolateral frontal gyrus (BA 8), and left insula (BA 13) areas. A positive relationship existed in the left claustrum and left thalamus. In females, negative changes existed in the left caudate body, left temporopolar area (BA 38), right orbitofrontal gyri (BA 47 and BA 10), and right dorsolateral prefrontal cortex (BA 46). A positive association was demonstrated in the left subthalamic nucleus and the left superior frontal gyrus. In white matter, an age-associated decrease in FDG uptake in males was shown in the left insula, and increased FDG uptake was found in the left corpus callosum. The female group had an age-associated negative correlation of FDG uptake only in the right corpus callosum. Conclusion: Using SPM, we found not only similar areas of brain, but also sex-specific cerebral areas of age-associated changes of FDG uptake

  2. Fluorine-18 fluorodeoxyglucose positron emission tomography and iodine-131 whole-body scintigraphy in the follow-up of differentiated thyroid cancer

    Metastases of differentiated thyroid cancer may show different uptake patterns for fluorine-18 fluorodeoxyglucose and [131I]NaI. FDG positron emission tomography (PET), iodine-131 whole-body scintigraphy (131I WBS) and magnetic resonance imaging were performed in 58 unselected patients, and spiral computed tomography (CT) of the lung in 25 patients. Thirty-eight patients presented with papillary carcinomas, 15 patients with follicular carcinomas and five patients with variants of follicular carcinoma. Primary tumour stage (pT) was pT1 in 3, pT2 in 19, pT3 in 11 and pT4 in 25 cases. For the detection of metastases, FDG PET was found to have a sensitivity of 50%, 131I WBS a sensitivity of 61%, and the two methods combined a sensitivity of 86%. When FDG PET was limited to patients with elevated thyroglobulin (Tg) levels and negative 131I WBS, the sensitivity of this algorithm was 82%. Of the 21 patients with lymph node metastases, seven presented with FDG uptake but no iodine uptake. In four of them, a second FDG hot spot appeared in a lymph node metastasis of normal size. Five of the seven patients underwent surgery. None of the eight patients with pulmonary metastases smaller than 1 cm exhibited FDG uptake, while five of them had iodine uptake. All had positive results on spiral CT. In conclusion, FDG PET cannot be substituted for 131I WBS. If the Tg level is elevated and 131I WBS is negative, FDG PET can be used to detect lymph node metastases and complements anatomical imaging. A spiral CT of the lung is useful to exclude pulmonary metastases before planning a dissection of iodine-negative lymph node metastases. (orig.)

  3. Age- and Sex-Associated Changes in Cerebral Glucose Metabolism in Normal Healthy Subjects: Statistical Parametric Mapping Analysis of F-18 Fluorodeoxyglucose Brain Positron Emission Tomography

    Kim, In-Ju; Kim, Seong-Jang; Kim, Yong-Ki (Dept. of Nuclear Medicine, Pusan National Univ. Hospital, Busan (Korea); Medical Research Institute, Pusan National Univ., Busan (Korea)). e-mail: growthkim@daum.net/growthkim@pusan.ac.kr)

    2009-12-15

    Background: The age- and sex-associated changes of brain development are unclear and controversial. Several previous studies showed conflicting results of a specific pattern of cerebral glucose metabolism or no differences of cerebral glucose metabolism in association with normal aging process and sex. Purpose: To investigate the effects of age and sex on changes in cerebral glucose metabolism in healthy subjects using fluorine-18 fluorodeoxyglucose (F-18 FDG) brain positron emission tomography (PET) and statistical parametric mapping (SPM) analysis. Material and Methods: Seventy-eight healthy subjects (32 males, mean age 46.6+-18.2 years; 46 females, mean age 40.6+-19.8 years) underwent F-18 FDG brain PET. Using SPM, age- and sex-associated changes in cerebral glucose metabolism were investigated. Results: In males, a negative correlation existed in several gray matter areas, including the right temporopolar (Brodmann area [BA] 38), right orbitofrontal (BA 47), left orbitofrontal gyrus (BA 10), left dorsolateral frontal gyrus (BA 8), and left insula (BA 13) areas. A positive relationship existed in the left claustrum and left thalamus. In females, negative changes existed in the left caudate body, left temporopolar area (BA 38), right orbitofrontal gyri (BA 47 and BA 10), and right dorsolateral prefrontal cortex (BA 46). A positive association was demonstrated in the left subthalamic nucleus and the left superior frontal gyrus. In white matter, an age-associated decrease in FDG uptake in males was shown in the left insula, and increased FDG uptake was found in the left corpus callosum. The female group had an age-associated negative correlation of FDG uptake only in the right corpus callosum. Conclusion: Using SPM, we found not only similar areas of brain, but also sex-specific cerebral areas of age-associated changes of FDG uptake

  4. Clinical value of whole-body F-18 fluorodeoxyglucose positron emission tomography / computed tomography in patients with carcinoma of unknown primary

    The purpose of the study is to investigate the clinical value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in detecting the primary sites in patients with carcinoma of unknown primary (CUP). The reports of FDG PET/CT scans of 164 patients with CUP syndrome in consecutive 2589 patients referred to our department from January 2006 to June 2010 were retrospectively reviewed. The final results were obtained from the pathologic reports, other imaging modalities diagnoses and clinical follow-up data. There were 142 cases in the results analysis, as 19 patients were lost to follow-up and three patients were excluded. FDG PET/CT successfully detected primary tumours in 67 (47.2%) out of 142 patients. Among this group, 53 were pathologically proved and 17 patients were confirmed by clinical follow-up. The primary sites of 38 (56.7%) were in lung, eight (11.9%) in nasopharynx and 13 (19.4%) in digestive system. Six patients were misdiagnosed by FDG PET/CT scan. FDG PET/CT could not detect the primary lesion in 66 patients, and three primary tumours were identified by conventional work-up after negative FDG PET/CT scan. The accuracy, sensitivity and specificity of FDG PET/CT scan in detecting the primary site in this study were 93.7%, 95.7% and 91.7%, respectively. FDG PET/CT scan changed the medical management of about 33.8% of 142 CUP patients. FDG PET/CT whole-body imaging is a valuable tool in detecting the primary tumour of patients with CUP site.

  5. Usefulness of Positron Emission Tomography With Fluorine-18-Fluorodeoxyglucose in Predicting Treatment Response in Unresectable Hepatocellular Carcinoma Patients Treated With External Beam Radiotherapy

    Purpose: To assess the significance of the ratio between standardized uptake values (SUV) of tumor and normal liver tissue obtained from positron emission tomography with fluorine-18-fluorodeoxyglucose (FDG-PET) in predicting the response of hepatocellular carcinoma (HCC) patients treated with external beam radiotherapy (EBRT). Methods and Materials: We retrospectively analyzed 35 HCC patients who were treated with EBRT between January 2004 and June 2007. All patients underwent FDG-PET in which SUV values were obtained from tumor and normal liver tissues and were used to calculate the ratios (SUVTumor/SUVLiver). After FDG-PET, patients received liver treatment including concurrent chemoradiation, transarterial chemoembolization plus RT, or intraarterial chemotherapy plus RT. Using three-dimensional conformal RT, median dose of 45 Gy was delivered in conventional fractions. Patients underwent abdominal/pelvic CT 1 month after RT, and treatment responses were evaluated according to the Response Evaluation Criteria in Solid Tumors criteria. Results: Patients were divided into high-SUV ratio group (n = 20) and low-SUV ratio group (n = 15) according to SUV ratio at a cutoff value of 2.5. Objective responses consisting of either complete response (CR) or partial response (PR) were observed in 16 and 6 patients (46% vs. 17%, p = 0.015), respectively; median survivals after RT were 8 months and 5 months (p = 0.41) for the high-SUV ratio group and the low-SUV ratio group, respectively. Rates of intrahepatic metastases (9% vs. 11%, p = 0.39) and distant metastases (32% vs. 32%, p = 0.27) showed no significant difference between two groups. Conclusions: External beam RT for HCC patients with higher SUV ratios resulted in higher response rates than for patients with lower SUV ratios. Treatment of HCC with higher SUV ratios did not result in increased survival; high rates of intrahepatic and distant metastases in both SUV groups may have affected patient survival. SUV ratios

  6. Brain metabolism in patients with vegetative state after post-resuscitated hypoxic-ischemic brain injury: statistical parametric mapping analysis of F-18 fluorodeoxyglucose positron emission tomography

    Yong Wook Kim; Hyoung Seop Kim; Young-Sil An

    2013-01-01

    Background Hypoxic-ischemic brain injury (HIBI) after cardiopulmonary resuscitation is one of the most devastating neurological conditions that causing the impaired consciousness.However,there were few studies investigated the changes of brain metabolism in patients with vegetative state (VS) after post-resuscitated HIBI.This study aimed to analyze the change of overall brain metabolism and elucidated the brain area correlated with the level of consciousness (LOC) in patients with VS after post-resuscitated HIBI.Methods We consecutively enrolled 17 patients with VS after HIBI,who experienced cardiopulmonary resuscitation.Overall brain metabolism was measured by F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) and we compared regional brain metabolic patterns from t7 patients with those from 15 normal controls using voxel-by-voxel based statistical parametric mapping analysis.Additionally,we correlated the LOC measured by the JFK-coma recovery scale-revised of each patient with brain metabolism by covariance analysis.Results Compared with normal controls,the patients with VS after post-resuscitated HIBI revealed significantly decreased brain metabolism in bilateral precuneus,bilateral posterior cingulate gyrus,bilateral middle frontal gyri,bilateral superior parietal gyri,bilateral middle occipital gyri,bilateral precentral gyri (PFEw correctecd <0.0001),and increased brain metabolism in bilateral insula,bilateral cerebella,and the brainstem (PFEw correctecd <0.0001).In covariance analysis,the LOC was significantly correlated with brain metabolism in bilateral fusiform and superior temporal gyri (P uncorrected <0.005).Conclusions Our study demonstrated that the precuneus,the posterior cingulate area and the frontoparietal cortex,which is a component of neural correlate for consciousness,may be relevant structure for impaired consciousness in patient with VS after post-resuscitated HIBI.In post-resuscitated HIBI,measurement of brain

  7. Qualitative visual trichotomous assessment improves the value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in predicting the prognosis of diffuse large B-cell lymphoma

    Xu Zhang; Wei Fan; Ying-Ying Hu; Zhi-Ming Li; Zhong-Jun Xia; Xiao-Ping Lin; Ya-Rui Zhang; Pei-Yan Liang; Yuan-Hua Li

    2015-01-01

    Introduction:Fluorine-18 fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) is a powerful tool for monitoring the response of diffuse large B-cell lymphoma (DLBCL) to therapy, but the criteria to interpret PET/CT results remain under debate. We investigated the value of post-treatment PET/CT in predicting the prognosis of DLBCL patients when interpreted according to qualitative visual trichotomous assessment (QVTA) criteria compared with the Deauvil e criteria. Methods:In this retrospective study, final PET/CT scans of DLBCL patients treated with rituximab-based regimens between October 2005 and November 2010 were interpreted using the Deauvil e and QVTA criteria. Survival curves were estimated using Kaplan-Meier analysis and compared using the log-rank test. Results:A total of 253 patients were enrol ed. The interpretation according to the Deauvil e criteria revealed that 181 patients had negative PET/CT scan results and 72 had positive results. The 3 year overal survival (OS) rate was significantly higher in patients with negative scan results than in those with positive results (91.6%vs. 57.5%, P<0.001). The 72 patients with positive scan results according to the Deauville criteria were divided into two groups by the interpretation according to the QVTA criteria:29 had indeterminate results, and 43 had positive results. The 3 year OS rate was significantly higher in patients with indeterminate scan results than in those with positive results (91.2%vs. 33.5%, P<0.001) but was similar between patients with negative and indeterminate scan results (91.6%vs. 91.2%, P=0.921). Conclusions:Compared with the Deauvil e criteria, using the QVTA criteria for interpreting post-treatment PET/CT scans of DLBCL patients is likely to reduce the number of false positive results. The QVTA criteria are feasible for therapeutic outcome evaluation and can be used to guide risk-adapted therapy.

  8. Imaging of atherosclerotic aorta of rabbit model by detection of plaque inflammation with fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

    ZHAO Quan-ming; FENG Ting-ting; ZHAO Xin; XU Zhan-min; LIU Yu; LI De-peng; LI Li-qin; SU Gong; ZHANG Xiao-xia

    2011-01-01

    Background Atherosclerotic plaque rupture is the primary mechanism of thrombosis which plays a key role in the onset of acute coronary syndromes. Detection of these plaques prone to rupture (vulnerable plaque) could be clinically significant for prevention of cardiac events. It has been shown that high metabolism cells have a high uptake of fluorine-18 fluorodeoxyglucose (18F-FDG). The objective of this study was to investigate the correlation of FDG uptake and the immuno-histochemistry parameters of plaques, and the effect of atorvastatin on vulnerable atherosclerotic plaque in a rabbit model.Methods Ten male New Zealand White rabbits were divided into three groups as follows: (1) normal control group (n=2,C group): the animals were fed a standard diet at 120 g/d and were given water ad labium; (2) atherosclerosis group (n=4,As group): animals were fed with high fat diet for 5 months after aortic endothelia damage; (3) treatment group (atherosclerosis + atorvastatin, n=4, Statin group): animals were fed with high fat diet for 5 months and then changed into normal chow plus atorvastatin (2.5 mg·d-1·kg-1) treatment for another 4 months. Then these four rabbits were imaged with fluorine-18 fluorodexyglucose positron emission tomography/computed tomography (PET/CT) and sacrificed for pathohistologic studies. FDG uptake by the aorta was expressed as target-to-background ratio (TBR). Maximal standardized uptake value (SUV) was measured over the thoracic and abdominal aortas. The aortic smooth muscle cell (SMC) number, CD-14 antibody positive cell (macrophage) number and the ratio of the thickness of fibrous cap to the thickness of lipid core (cap-to-core ratio) in atherosclerotic plaques were analyzed.Results As group showed significantly higher uptake of FDG than C group (SUVs: 0.746±0.172 vs. 0.286±0.073, P <0.001). After 4 months of atorvastatin treatment and the modification of diet, SUVs decreased significantly (Statin group:0.550±0.134, compared to As group

  9. Paget's disease of pelvis mimicking metastasis in a patient with lung cancer evaluated using staging and follow-up imaging with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography

    Paget's disease of bone is a benign disease, of uncertain etiology, characterized by an accelerated turnover, that is, bone resorption and formation. Paget's disease may be present in up to 5% of the population, and the majority of cases are asymptomatic. We report the imaging findings of Paget's disease of pelvis discovered incidentally in patient with lung cancer evaluated by fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for staging. FDG PET-CT scan showed intense uptake in the right lung lower lobe primary and mediastinal lymph nodes. Furthermore, increased uptake noted in left hemipelvis suggestive of Paget's disease. He underwent follow-up FDG PET-CT after chemotherapy showed decrease in lung mass and mediastinal nodes. However, the uptake in left hemipelvis remains same confirming Paget's disease

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

    Purpose: To assess the value of 18F-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

  11. Primary neuroendocrine carcinoma of breast with liver and bone metastasis detected with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography

    Cases of primary neuroendocrine carcinoma (NEC) of the breast have been reported, though rare. We report the case of a 45-year-old woman presented with jaundice and evaluated to have liver metastasis from neuroendocrine origin. She underwent whole body positron emission tomography/computed tomography, which showed left breast lesion and bone metastasis. Fine-needle aspiration (FNA) of breast revealed a NEC. A diagnosis of a primary NEC of the breast was rendered with hepatic and bone metastasis. She was treated with peptide receptor radionuclide therapy and is on follow-up

  12. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging of an isolated subcutaneous loin metastasis from primary papillary carcinoma of the thyroid

    Differentiated thyroid cancer frequently metastasizes but generally spreads to regional cervical lymph nodes and, in advanced cases, to the lungs and/or skeleton. Metastases to the skin/subcutaneous tissue are rare. We report 45-year-old male patient presented with a loin swelling which on biopsy showed a papillary carcinoma and referred for fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) to find out the primary disease. PET/CT showed abnormal FDG uptake within a loin metastasis and right lobe thyroid nodule. Fine-needle aspiration from nodule showed papillary carcinoma. Because thyroid cancer can rarely metastasize to the skin, attention should be given to that region during interpretation of the images. He was advised total thyroidectomy and metastasis excision

  13. Rare case of primary inferior vena cava leiomyosarcoma on F-18 fluorodeoxyglucose positron emission tomography-computed tomography scan: Differentiation from nontumor thrombus in a background of procoagulant state

    We report a rare case of leiomyosarcoma of the inferior vena cava (IVC) in which F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography-computed tomography (PET-CT) scan provided vital evidence, which led to its diagnosis, in a background of procoagulant state of the patient, where previous ultrasound-Doppler and echocardiography studies were nonspecific and revealed bilateral lower limb deep vein thrombosis with thrombus in IVC. The whole body F-18 FDG PET-CT scan was done in view of no significant improvement in clinical status of the patient over few months in spite of appropriate medical management. FDG PET-CT scan revealed high grade uptake in a large mass lesion occupying the right atrium, extending superiorly into terminal superior vena cava, inferiorly into dilated IVC and probably into hepatic veins. CT guided biopsy of this F-18 FDG avid mass was consistent with the diagnosis of leiomyosarcoma, which however was not amenable to surgery at this stage. F-18 FDG PET-CT accurately differentiated tumor mass from bland thrombus and further had a significant impact on the management, since aggressive surgery combined with adjuvant therapy offers the best outcome for patients with leiomyosarcoma of the IVC

  14. Potential time benefit in the assessment of recurrent rat rhabdomyosarcoma using positron emission tomography (PET) with 18fluorodeoxyglucose depends on therapy-specific growth delay

    Purpose: to correlate the potential time benefit of 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) in terms of early detection of recurrences of subcutaneously growing R1H tumors with therapy-specific parameters of recurrent tumor. Material and methods: twelve, eleven, and seven recurrences were followed after fractionated radiotherapy, surgery, and chemotherapy for 6 months, respectively, and 18FDG-PET was performed weekly using a conventional full-ring whole-body PET scanner. By comparing PET results and actual tumor volume, the time benefit of 18FDG-PET in detection of recurrent tumors of 0.1, 0.2, and 0.5 cm3 was determined for the different treatment strategies. Results: a significant time benefit of 18FDG-PET of 26.9 days and 67 days was solely determined for recurrences after radiotherapy of 0.2 cm3 and 0.5 cm3, respectively. The potential time benefit showed a strong correlation with growth delay, which was increased after radiotherapy due to a pronounced tumor-bed effect. Conclusion: the potential time benefit of 18FDG-PET is strongly determined by the growth kinetics of the recurrence. A tumor-bed effect, which is a phenomenon solely seen after radiotherapy, favors early detection by 18FDG-PET. The experimental data, clinical experience and theoretical consideration all indicate a noticeable benefit of 18FDG-PET especially after radiotherapeutic treatment. (orig.)

  15. The role of fluorine-18-fluorodeoxyglucose positron emission tomography in evaluating the response to tyrosine-kinase inhibitors in patients with metastatic primary renal cell carcinoma

    Positron emission tomography-computed tomography (PET-CT) using fluorodeoxyglucose (FDG) is increasingly used in the evaluation of patients with advanced renal cell carcinoma (RCC), primarily for staging purposes. The aim of this paper is to perform a systematic review about the usefulness of PET-CT using FDG in response assessment after treatment with tyrosine-kinase inhibitors (TKIs) in patients with advanced RCC. The scientific literature about the role of PET-CT using FDG in the assessment of response to treatment with TKIs in patients affected by advanced RCC was systematically reviewed. Seven studies about the role of PET-CT using FDG in the response assessment after treatment with TKIs (essentially sunitinib and sorafenib) in advanced RCC were retrieved in full-text and analysed, to determine the predictive role of this morpho-functional imaging method on patient outcome. To date, the role of PET-CT using FDG in evaluating the response to TKIs in metastatic RCC patients is still not well defined, partly due to heterogeneity of available studies; however, PET-CT reveals potential role for the selection of patients undergoing therapy with TKIs. The use of contrast-enhanced PET-CT appears to be promising for a “multi-dimensional” evaluation of treatment response in these patients

  16. Fluorine-18-fluorodeoxyglucose positron emission tomography to evaluate recurrent gastric cancer after surgical resection: a systematic review and meta-analysis.

    Li, Panli; Liu, Qiufang; Wang, Chen; Wang, Tongbo; Liu, Jianjun; Huang, Gang; Song, Shaoli

    2016-04-01

    We aimed to explore the diagnostic accuracy of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) for detection of gastric cancer recurrence after surgical resection through a systematic review and meta-analysis. "PubMed", EMBASE, Web of Knowledge and Springer, from the beginning of 2002 to Feb 2015, were searched for studies evaluating the diagnostic performance of 18F-FDG PET in detecting recurrent gastric cancer. We calculated sensitivities, specificities, diagnostic odds ratios and likelihood ratios, and constructed summary receiver operating characteristic curves. Fourteen studies (828 patients) were included. On a per-patient basis, the forest plots showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of (18)F-FDG PET or PET/CT were 0.85 [95 % confidence interval (CI) 0.75-0.92], 0.78 (95 % CI 0.72-0.84), 3.9 (95 % CI 2.9-5.4), 0.19 (95 % CI 0.11-0.34), and 21 (95 % CI 9-47), respectively. On a per-lesion basis, the pooled sensitivity was 0.75 (95 % CI 0.61-0.86). The area under the SROC curve of PET/CT on the basis of per-patient was 0.86. (18)F-FDG PET had great value in the detection of gastric cancer recurrence after surgical resection. The sensitivities of (18)F-FDG PET were 85 and 75 %, respectively, on per-patient basis and on per-lesion basis. PMID:26830546

  17. Single-Institution Experience in the Treatment of Primary Mediastinal B Cell Lymphoma Treated With Immunochemotherapy in the Setting of Response Assessment by 18Fluorodeoxyglucose Positron Emission Tomography

    Purpose: Excellent outcomes obtained after infusional dose-adjusted etoposide, doxorubicin, cyclophosphamide, vincristine, prednisone, and rituximab (R-EPOCH) alone have led some to question the role of consolidative radiation therapy (RT) in the treatment of primary mediastinal B cell lymphoma (PMBL). We reviewed the outcomes in patients treated with 1 of 3 rituximab-containing regimens (cyclophosphamide, doxorubicin, vincristine, prednisone [R-CHOP]; hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone [R-HCVAD], or R-EPOCH) with or without RT. We also evaluated the ability of positron emission tomography–computed tomography (PET-CT) to identify patients at risk of relapse. Methods and Materials: We retrospectively identified 97 patients with diagnoses of stage I/II PMBCL treated at our institution between 2001 and 2013. The clinical characteristics, treatment outcomes, and toxicity were assessed. We analyzed whether postchemotherapy PET-CT could identify patients at risk for progressive disease according to a 5 point scale (5PS) Deauville score assigned. Results: Among 97 patients (median follow-up time, 57 months), the 5-year overall survival rate was 99%. Of patients treated with R-CHOP, 99% received RT; R-HCVAD, 82%; and R-EPOCH, 36%. Of 68 patients with evaluable end-of-chemotherapy PET-CT scans, 62% had a positive scan (avidity above that of the mediastinal blood pool [Deauville 5PS = 3]), but only 9 patients experienced relapse (n=1) or progressive disease (n=8), all with a 5PS of 4 to 5. Of the 25 patients who received R-EPOCH, 4 experienced progression, all with 5PS of 4 to 5; salvage therapy (RT and autologous stem cell transplantation) was successful in all cases. Conclusion: Combined modality immunochemotherapy and RT is well tolerated and effective for treatment of PMBCL. A postchemotherapy 5PS of 4 to 5, rather than 3 to 5, can identify patients at high risk of progression who should be considered for therapy beyond

  18. [F-18]Fluorodeoxyglucose positron emission tomography can predict pathological tumor stage and proliferative activity determined by Ki-67 in clinical stage IA lung adenocarcinomas

    The objective of this study was to predict a malignant grade of lung cancer by fluorodeoxyglucose positron emission tomography (FDG-PET) scanning, we investigated the correlation between FDG uptake and pathological tumor stage, proliferative activities determined by Ki-67 and cyclin D1, and an alteration of p53, in clinical stage (c-stage) IA lung adenocarcinomas. FDG-PET was performed for 71 patients with c-stage IA lung adenocarcinomas. FDG uptake was measured by a contrast ratio (CR) between the tumor and contralateral lung. Ki-67, cyclin D1 and p53 staining scores were examined by immunohistochemistry. The lesions with ground-glass opacity were found in 26 patients, and solid lesions in 45 by computed tomography. The pathological tumor stages (p-stage) were stage IA in 59 and more advanced stages in 12. The latter had significantly higher CR value than the former (P<0.001). Patients with CR≥0.55 could be predicted to be at advanced tumor stages, with a sensitivity of 0.83 and a specificity of 0.82. The CR and staining scores of Ki-67 were significantly correlated with each other (P<0.0001), and both the values were significantly higher in advanced tumor stages than in p-stage IA, and were also significantly higher in tumors with intratumoral lymphatic, vascular and pleural involvements than in those without such features (P<0.05-0.0001). In c-stage IA lung adenocarcinomas, the FDG uptake can predict p-stage and tumor proliferative activity determined by Ki-67. For c-stage IA lung adenocarcinomas showing CR≥0.55, mediastinoscopy or neoadjuvant chemotherapy is indicated. (author)

  19. The value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in asymptomatic examinees with unexplained elevated blood carcinoembryonic antigen levels

    Li, Wenfeng [The First Affiliated Hospital of Wenzhou Medical University, Laboratory for Advanced Interdisciplinary Research, Institutes of Translational Medicine, Wenzhou (China); The First Affiliated Hospital of Wenzhou Medical University, Department of Radiation Oncology, Wenzhou (China); Yin, Weiwei [The First Affiliated Hospital of Wenzhou Medical University, Division of PET/CT, Department of Radiology, Wenzhou (China); Ou, Rongying [The First Affiliated Hospital of Wenzhou Medical University, Laboratory for Advanced Interdisciplinary Research, Institutes of Translational Medicine, Wenzhou (China); The First Affiliated Hospital of Wenzhou Medical University, Department of Gynaecology and Obstetrics, Wenzhou (China); Chen, Ting; Xiong, Lingling; Xu, Yunsheng [The First Affiliated Hospital of Wenzhou Medical University, Laboratory for Advanced Interdisciplinary Research, Institutes of Translational Medicine, Wenzhou (China); The First Affiliated Hospital of Wenzhou Medical University, Department of Dermatovenereology, Wenzhou (China); Cheng, Dezhi; Xie, Deyao [The First Affiliated Hospital of Wenzhou Medical University, Laboratory for Advanced Interdisciplinary Research, Institutes of Translational Medicine, Wenzhou (China); The First Affiliated Hospital of Wenzhou Medical University, Department of Cardiothoracic Surgery, Wenzhou (China); Zheng, Xiangwu; Zhao, Liang [The First Affiliated Hospital of Wenzhou Medical University, Laboratory for Advanced Interdisciplinary Research, Institutes of Translational Medicine, Wenzhou (China); The First Affiliated Hospital of Wenzhou Medical University, Division of PET/CT, Department of Radiology, Wenzhou (China); The First Affiliated Hospital of Wenzhou Medical University, Institutes of Intelligent and Molecular Imaging, Wenzhou (China)

    2016-04-15

    Cancer is still a clinical challenge, with many efforts invested in order to achieve timely detection. Unexplained elevated blood carcinoembryonic antigen levels are occasionally observed in an asymptomatic population and considered as a risk factor of cancers. The purpose of this study was to determine the validity of 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) for detecting cancer in an asymptomatic population with an unexplained elevation in blood carcinoembryonic antigen (CEA) levels. This retrospective study included a total of 1920 asymptomatic examinees conducted from August 2011 through September 2013. The participants underwent CEA assay and conventional medical imaging (CEA-conventional), or CEA assay and F-18 FDG-PET/CT (CEA-PET/CT). The validity of conventional medical imaging and CEA-PET/CT scanning for detecting cancer and early-stage cancer in an asymptomatic population with an unexplained elevation in blood CEA levels were evaluated. Sensitivity, specificity, cancer detection rate, missed cancer detection rate, early-stage cancer detection rate, and early-stage cancer ratio using the CEA-PET/CT scanning were 96.6 %, 100 %, 10.4 %, 0.4 %, 3.7 %, and 34.5 %, respectively. In contrast, the corresponding values obtained using the conventional medical imaging were 50.6 % (P < 0.0001), 100 % (P > 0.9999), 50.6 % (P < 0.0001), 99.9 % (P = 0.055), 2.6 % (P < 0.0001), 2.5 % (P = 0.04), 0.7 % (P = 0.0004), and 14.5 % (P = 0.002), respectively. The F-18 FDG-PET/CT scanning significantly improved the validity of the cancer detection program in the asymptomatic population with an unexplained elevation in CEA levels. (orig.)

  20. F-18 Fluorodeoxyglucose Gamma Camera Positron Emission Tomography identifies those patients with non-small cell lung cancer who are suitable for surgery?

    This study assessed the accuracy of positron emission tomography using a modified gamma camera (GC-PET) versus that of CT for staging mediastinal involvement in non-small cell lung cancer. The potential impact of GCPET imaging on patient management was also estimated. 98 patients underwent CT imaging as part of routine management followed by GC-PET imaging as part of the study. GC-PET images were reported without knowledge of CT findings. For each patient, nodal resectability status derived from GC-PET and that from CT were compared with the histological stage established by mediastinoscopy or surgery. Potential impact on management was assessed by comparing actual management with that which would have resulted had the guidelines of the National Institute for Health and Clinical Excellence (NICE) for the use of dedicated PET been applied to GC-PET results. GC-PET differentiated resectable from unresectable lymph node involvement with an accuracy of 90%. Sensitivity and specificity were 79% and 93% respectively (ppv 73%, npv 95%). CT differentiated resectable from unresectable lymph node involvement with an accuracy of 72%, and a sensitivity and specificity of 64% and 74% respectively (ppv 39%, npv 89%). Management based on GC-PET results and NICE recommendations would have avoided 14 unnecessary mediastinoscopies and prevented three or possibly four abandoned resections. Two additional unnecessary mediastinoscopies would have resulted. This study suggests that GC-PET is more accurate than CT for nodal staging in NSCLC, and likely to impact favourably on management where dedicated PET is unavailable. (author)

  1. The value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography in asymptomatic examinees with unexplained elevated blood carcinoembryonic antigen levels

    Cancer is still a clinical challenge, with many efforts invested in order to achieve timely detection. Unexplained elevated blood carcinoembryonic antigen levels are occasionally observed in an asymptomatic population and considered as a risk factor of cancers. The purpose of this study was to determine the validity of 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) for detecting cancer in an asymptomatic population with an unexplained elevation in blood carcinoembryonic antigen (CEA) levels. This retrospective study included a total of 1920 asymptomatic examinees conducted from August 2011 through September 2013. The participants underwent CEA assay and conventional medical imaging (CEA-conventional), or CEA assay and F-18 FDG-PET/CT (CEA-PET/CT). The validity of conventional medical imaging and CEA-PET/CT scanning for detecting cancer and early-stage cancer in an asymptomatic population with an unexplained elevation in blood CEA levels were evaluated. Sensitivity, specificity, cancer detection rate, missed cancer detection rate, early-stage cancer detection rate, and early-stage cancer ratio using the CEA-PET/CT scanning were 96.6 %, 100 %, 10.4 %, 0.4 %, 3.7 %, and 34.5 %, respectively. In contrast, the corresponding values obtained using the conventional medical imaging were 50.6 % (P < 0.0001), 100 % (P > 0.9999), 50.6 % (P < 0.0001), 99.9 % (P = 0.055), 2.6 % (P < 0.0001), 2.5 % (P = 0.04), 0.7 % (P = 0.0004), and 14.5 % (P = 0.002), respectively. The F-18 FDG-PET/CT scanning significantly improved the validity of the cancer detection program in the asymptomatic population with an unexplained elevation in CEA levels. (orig.)

  2. Does the intensity of diffuse thyroid gland uptake on F-18 fluorodeoxyglucose positron emission tomography/computed tomography scan predict the severity of hypothyroidism? Correlation between maximal standardized uptake value and serum thyroid stimulating hormone levels

    F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) scan and hypothyroidism. The aim was to determine whether the intensity of diffuse thyroid gland uptake on F-18 FDG PET/CT scans predicts the severity of hypothyroidism. A retrospective analysis of 3868 patients who underwent F-18 FDG PET/CT scans, between October 2012 and June 2013 in our institution for various oncological indications was done. Out of them, 106 (2.7%) patients (79 females, 27 males) presented with bilateral diffuse thyroid gland uptake as an incidental finding. These patients were investigated retrospectively and various parameters such as age, sex, primary cancer site, maximal standardized uptake value (SUVmax), results of thyroid function tests (TFTs) and fine-needle aspiration cytology results were noted. The SUVmax values were correlated with serum thyroid stimulating hormone (S. TSH) levels using Pearson's correlation analysis. Pearson's correlation analysis. Clinical information and TFT (serum FT3, FT4 and TSH levels) results were available for 31 of the 106 patients (27 females, 4 males; mean age 51.5 years). Twenty-six out of 31 patients (84%) were having abnormal TFTs with abnormal TSH levels in 24/31 patients (mean S. TSH: 22.35 μIU/ml, median: 7.37 μIU/ml, range: 0.074-211 μIU/ml). Among 7 patients with normal TSH levels, 2 patients demonstrated low FT3 and FT4 levels. No significant correlation was found between maximum standardized uptake value and TSH levels (r = 0.115, P > 0.05). Incidentally detected diffuse thyroid gland uptake on F-18 FDG PET/CT scan was usually associated with hypothyroidism probably caused by autoimmune thyroiditis. Patients should be investigated promptly irrespective of the intensity of FDG uptake with TFTs to initiate replacement therapy and a USG examination to look for any suspicious nodules

  3. Prognostic significance of positron emission tomography using fluorine-18-fluorodeoxyglucose in patients treated for malignant lymphoma; Prognostische Bedeutung der Therapiekontrolle durch die Positronen-Emissions-Tomographie mit Fluor-18-Deoxyglukose bei Patienten mit malignen Lymphomen

    Cremerius, U.; Zimny, M.; Bares, R.; Buell, U. [Dept. of Nuclear Medicine, Univ. of Technology, Aachen (Germany); Fabry, U.; Osieka, R. [Dept. of Internal Medicine IV, Univ. of Technology, Aachen (Germany); Neuerburg, J. [Dept. of Diagnostic Radiology, Univ. of Technology, Aachen (Germany)

    2001-02-01

    Aim: To evaluate the prognostic significance of positron emission tomography (PET) using fluorine-18-[2]-fluoro-2-deoxyglucose (FDG) in patients treated for Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL) compared to conventional restaging (CRS). Methods: Fifty-six patients with either HD (n = 22), high-grade NHL (n = 26) or centrocytic-centroblastic NHL (n = 8) were included. PET was performed in 41 patients for treatment reevaluation up to three months after therapy and in patients with persisting residual masses (n = 10) or suspected relapse (n = 5) four to twelve months after treatment. The scans were evaluated qualitatively and quantitatively using standardised uptake values (SUV). Progression-free survival (PFS) was estimated to assess the prognostic value of FDG PET and clinical follow-up was taken as gold standard. Results: PET was positive in nineteen of 41 patients studied for treatment reevaluation. Progression was observed after a median interval of two months (range 0-15) in sixteen of 19 patients after a positive PET scan and in three of 22 patients after a negative scan (p <.001). Median duration of follow-up in progression-free patients was 21 months (range 6-72). In patients with a partial remission in CRS progression was more common in PET-positive than in PET-negative patients (5 of 7 vs. 1 of 14; p <.01) and positivity with PET was associated with poorer PFS (p <.0025). PET studies performed four to twelve months after treatment were true negative in seven, true positive in five and false-positive in three patients. SUV > 11.35 of lymphoma lesions was associated with poorer PFS than SUV <11.35 (p <0.025). Conclusion: We conclude that FDG PET after treatment of malignant lymphoma has a high prognostic value and should be recommended in patients with persistence of residual masses. (orig.) [German] Ziel: Untersuchung der prognostischen Bedeutung der Positronen-Emissions-Tomographie (PET) mit F-18-Fluordeoxyglukose im Vergleich zu

  4. Primary central nervous system lymphoma in an human immunodeficiency virus-infected patient mimicking bilateral eye sign in brain seen in fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography

    Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) has proven useful in the diagnosis, staging, and detection of metastasis and posttreatment monitoring of several malignancies in human immunodeficiency virus (HIV)-infected patients. It also has the ability to make the important distinction between malignancy and infection in the evaluation of central nervous system (CNS) lesions, leading to the initiation of the appropriate treatment and precluding the need for invasive biopsy. We report an interesting case of HIV positive 35-year-old woman presented with headache, disorientation, and decreased level of consciousness. She underwent whole body PET/CT which showed multiple lesions in the cerebrum which mimics bilateral eye in brain. A diagnosis of a primary CNS lymphoma was made and patient was started on chemotherapy

  5. Can Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography Be Used As a Useful Method to Evaluate the Treatment Response to Neoadjuvant Therapy Combined With Sorafenib and Anti-VEGF in Children Diagnosed With Metastatical Bone Sarcoma?

    Tacyildiz, Nurdan; Tanyildiz, Hikmet Gulsah; Dincaslan, Handan Ugur; Yavuz, Gulsan; Unal, Emel; Ozkan, Elgin; Soydal, Cigdem; Kucuk, Ozlem; Yildiz, Yusuf

    2016-01-01

    Background The prognosis is still poor for patients with a metastatic bone tumor and new treatment approaches (anti-VEGF and tyrosine kinase inhibitors vs) are therefore needed. Objectives The aim of our study was to evaluate how the primary and metastatic lesions of our patients with a bone tumor were affected by these treatments and to determine the importance of the 18F-FDG PET method. Patients and Methods Twenty metastatic bone tumor cases were included. Sorafenib and anti-VEGF were added to the standard treatment in cases with widespread metastatic disease at diagnosis or after neoadjuvant chemotherapy showing less than 90% tumor necrosis in the surgical sample. Positron emission tomography (PET) imaging was performed at diagnosis, the preoperative period following neoadjuvant chemotherapy, during postoperative follow-up, and when treatment was discontinued. Results The primary treatment region median SUVmax level decreased from 7.35 to 2.5 in the living patients (n = 16) while there was no significant decrease in the patients who succumbed to the disease (P < 0.001). Comparison of the pre- and post-treatment metastasis region median SUVmax levels in patients with metastatic involvement showed a decrease from 2.1 to 0 in the surviving patients but only from 4.8 to 3.2 in the deceased patients (P < 0.01). Survival results indicated that 28.6% of the patients receiving classical treatment only died while all the patients receiving additional sorafenib and anti-VEGF survived. Conclusions 18F-PET may be a useful technique before and during the follow-up of neoadjuvant treatment in pediatric metastatic bone tumor patients. The addition of sorafenib and anti-VEGF to classical treatment has a favorable contribution to the response and therefore the survival duration. PMID:27307968

  6. Single-Institution Experience in the Treatment of Primary Mediastinal B Cell Lymphoma Treated With Immunochemotherapy in the Setting of Response Assessment by {sup 18}Fluorodeoxyglucose Positron Emission Tomography

    Pinnix, Chelsea C. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Dabaja, Bouthaina, E-mail: bdabaja@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ahmed, Mohamed Amin [Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chuang, Hubert H. [Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Costelloe, Colleen [Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wogan, Christine F.; Reed, Valerie [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Romaguera, Jorge E.; Neelapu, Sattva; Oki, Yasuhiro [Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rodriguez, M. Alma [Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Office of Medical Affairs, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Fayad, Luis; Hagemeister, Frederick B.; Nastoupil, Loretta; Turturro, Francesco; Fowler, Nathan; Fanale, Michelle A. [Department of Lymphoma/Myeloma, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Nieto, Yago; Khouri, Issa F.; Ahmed, Sairah [Department of Stem Cell Transplantation, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); and others

    2015-05-01

    Purpose: Excellent outcomes obtained after infusional dose-adjusted etoposide, doxorubicin, cyclophosphamide, vincristine, prednisone, and rituximab (R-EPOCH) alone have led some to question the role of consolidative radiation therapy (RT) in the treatment of primary mediastinal B cell lymphoma (PMBL). We reviewed the outcomes in patients treated with 1 of 3 rituximab-containing regimens (cyclophosphamide, doxorubicin, vincristine, prednisone [R-CHOP]; hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone [R-HCVAD], or R-EPOCH) with or without RT. We also evaluated the ability of positron emission tomography–computed tomography (PET-CT) to identify patients at risk of relapse. Methods and Materials: We retrospectively identified 97 patients with diagnoses of stage I/II PMBCL treated at our institution between 2001 and 2013. The clinical characteristics, treatment outcomes, and toxicity were assessed. We analyzed whether postchemotherapy PET-CT could identify patients at risk for progressive disease according to a 5 point scale (5PS) Deauville score assigned. Results: Among 97 patients (median follow-up time, 57 months), the 5-year overall survival rate was 99%. Of patients treated with R-CHOP, 99% received RT; R-HCVAD, 82%; and R-EPOCH, 36%. Of 68 patients with evaluable end-of-chemotherapy PET-CT scans, 62% had a positive scan (avidity above that of the mediastinal blood pool [Deauville 5PS = 3]), but only 9 patients experienced relapse (n=1) or progressive disease (n=8), all with a 5PS of 4 to 5. Of the 25 patients who received R-EPOCH, 4 experienced progression, all with 5PS of 4 to 5; salvage therapy (RT and autologous stem cell transplantation) was successful in all cases. Conclusion: Combined modality immunochemotherapy and RT is well tolerated and effective for treatment of PMBCL. A postchemotherapy 5PS of 4 to 5, rather than 3 to 5, can identify patients at high risk of progression who should be considered for therapy beyond

  7. Preoperative assessment of asymptomatic adnexal masses by positron emission tomography and F-18-fluorodeoxyglucose

    Aim: To evaluate use of F-18-FDG-PET in assessment of dignity of asymptomatic adnexal masses. Methods: 85 asymptomatic patients with suspicious, asymptomatic adnexal masses were evaluated. Static FDG-PET (Exact HR+ or ECAT 931) imaging of the abdomen was performed following application of 222-555 MBq F-18-FDG. Iterative reconstruction was applied. PET data were analysed visually, at first without and second together with MRT images. Final diagnosis was made by histopathology. Results: FDG-PET allowed correct identification of 4 of 8 malignant adnexal tumors. False negative results were obtained in 2 adenocarcinomas stage pT1a and 2 borderline-tumors. In 60 out of 77 benign adnexal masses malignancy could be excluded. False positive FDG-uptake, partly because of misinterpretation of gastrointestinal activity, was found in 3 inflammatory processes, 1 teratoma, 1 benign schwannoma, 1 dermoid cyst, 1 benign thecoma, 1 serous cyst, 1 serous cystadenoma, 2 mucinous cystadenomas, 2 corpus luteum cysts, 3 endometriosic cysts and 1 sactosalpinx. The overall sensitivity and specifity of FDG-PET alone were 50% and 78%. Evaluation together with MRT images showed a sensitivity of 50% and a specifity of 86%. (orig.)

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

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

    2016-01-01

    Infantile fibrosarcoma (IFS) is a rare soft-tissue sarcoma originating from extremities and occasionally from axial soft tissue. The prognosis is good with favorable long-term survival. It is rarely metastasizing tumor, the chances being lesser with IFS originating from extremities. Use of neoadjuvant chemotherapy (NACT) as a treatment regime further reduces the chances of local relapse and distant metastasis. The organs commonly affected in metastatic IFS are lungs and lymph nodes. We report...

  9. PET STUDIES WITH L-[1-C-11]TYROSINE, L-[METHYL-C-11]METHIONINE AND F-18 FLUORODEOXYGLUCOSE IN PROLACTINOMAS IN RELATION TO BROMOCRYPTINE TREATMENT

    DAEMEN, BJG; ZWERTBROEK, R; ELSINGA, PH; PAANS, AMJ; DOORENBOS, H; VAALBURG, W

    1991-01-01

    Aspects of metabolism in prolactinomas were investigated by positron emission tomography using L-[1-C-11]tyrosine, L-[methyl-C-11]methionine and F-18-fluorodeoxyglucose (18FDG). Using L-[1-C-11]tyrosine, four patients were monitored prior to and 18 h after an injection of 50 mg bromocryptine. At 18

  10. Clinical utility of 18 Fluorodeoxyglucose (FDG)-PET/CT scans in patients with suspect ocular tuberculosis

    Salil Mehta

    2013-01-01

    Systemic imaging of patients with suspect ocular tuberculosis include chest X-rays and computed tomography (CT) scans. Reports have suggested a role for 18 fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT) scans. We report on the clinical utility of 18 FDG PET/CT in two patients. Case 1: A 38-year-old female patient presented with recurrent anterior uveitis. A 18 FDG-PET scan revealed metabolically active supraclavicular and chest lymph nodes. An aspiration cytology of the cervi...

  11. Fluorodeoxyglucose positron emission tomography-computed tomography findings in a case of xanthogranulomatous pyelonephritis

    Joshi, Prathamesh; Lele, Vikram; Shah, Hardik

    2013-01-01

    Xanthogranulomatous pyelonephritis (XGNP) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction. This condition can clinically present as recurrent urinary tract infections, flank pain, hematuria, and occasionally sepsis, and weight loss. This condition is usually associated with obstructing renal calculus. We present 18-fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET/CT) findings in a...

  12. Metabolism of human gliomas: Assessment with H-1 MR spectroscopy and F-18 fluorodeoxyglucose PET

    Localized hydrogen-1 magnetic resonance (MR) spectroscopy and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) were employed to obtain metabolic information from intracranial gliomas. Advantages and difficulties associated with comparison of results from the two modalities were realized. Forty patients were studied with H-1 MR spectroscopy. MR signal intensities from lactate, N-acetylaspartate (NAA), choline, and creatine from a volume of interest containing the tumor and a contralateral volume were obtained and evaluated. NAA signal intensities were generally decreased in the tumor spectra, and choline signal intensities were elevated. H-1 MR spectroscopy was unsuccessful in eight patients, and FDG PET scans were not obtained in four of the patients with successful MR spectroscopic examinations. Lactate signal intensity was detected in 10 of the 28 patients who had successful H-1 MR spectroscopic and FDG PET studies. Lactate signal intensities were observed in lesions shown at FDG PET to be hypermetabolic, as well as in lesions found to be hypometabolic

  13. Prognostic value of SUVmax measured by fluorine 18 fluorodeoxyglucose positron emission tomography with computed tomography in patients with pancreatic cancer

    Recent studies have been conducted on the relationship between fluorodeoxyglucose (FDG)uptake in F 18 FDG PET/CT and prognosis in patients with pancreatic cancer, but these studies have been carried out in small numbers of patients. The aim of this retrospective study was to determine in a large number of patients whether glucose metabolism as assessed by F 18 FDG PET/CT provides prognostic information independent of established prognostic factors in patients with pancreatic cancer. We reviewed retrospectively the medical records of 165 patients (men 105, women 60, mean age 67±10 years)with a diagnosis of pancreatic cancer that had undergone F 18 FDG PET/CT as part of a pretreatment workup from January 2004 to December 2009. Subsequently, all patients underwent surgery, cyberknife, radiotherapy, and/or chemotherapy. For the analysis, patients were classified by age, demographic data, maximum standardized uptake value (SUVmax), size, location, serum level of CA199, type of treatment, and AJCC stage. The relationship between FDG uptake and survival was analyzed using the Kaplan Meier with log Rank test and Cox's proportional hazard regression methods. Median survival for all 165 study subjects was 290 days and median SUV by PET/CT was 5.8 (range:0-25.1). Patients were allocated to high (>4.1)and low (≤4.1)SUV groups, and median survivals of these patients were 229 days and 610 days, respectively, which were significantly different (p<0.0001). Furthermore, SUVmax was found to be significantly related to survival in each stage, i.e., there were 1267 days in stage I, 440 days in stage II, 299 days in stage III, and 143 days in stage IV (p<0.0001). The median survival was also found to be significantly related to tumor size (p=0.0001), site (p=0.0298), serum level of CA199 (p=0.0017), distant metastasis (p<0.0001), and type of treatment (p<0.0001). Multivariate analysis study revealed that the patients with a low SUV (p=0.0298), a lower serum level of CA199 (p=0.0071), a lower stage (p=0.0017), and no distant metastasis (p<0.0001)had longer survivals. In addition, SUVmax values were found to have a similar hazard ratio of distant metastasis; it was well known predictor. Furthermore, SUVmax values showed a higher hazard ratio than that of other clinico pathologic predictors. The present study shows that SUVmax on F 18 FDG PET/CT can provide a prognostic information in patients with pancreatic cancer

  14. differentiation of benign from malignant lesions of heart and pericardium: the feasibility of Fluorine-18 fluorodeoxyglucose positron emission tomography CT

    Objective: To assess the feasibility of integrated 18F-FDG PET-CT for the differentiation of malignancy from benign lesions of heart and pericardium. Methods: A total of 23 cases (malignancy: benign = 13:10) with cardiac and pericardial lesions confirmed by pathology or clinic were analyzed in the present study. All lesions were evaluated semi-quantitatively using maximum standard uptake values (SUVmax) and SUVmax lesion/blood, and the density of the heart and pericardium lesions and the relationship with surrounding tissues were evaluated. The differences of SUVmax and SUVmax lesion/blood between benign and malignant lesions were analyzed using Man-Whitney test. Subsequently, the diagnostic sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for CT and PET-CT respectively. Results: The maximum SUV showed significant difference between malignancy (6.5) and benign (1.5) (Z=-3.601, P18F-FDG PET-CT can correctly differentiate benignity and malignancy of cardiac and pericardial lesions. (authors)

  15. DOBUTAMINE MAGNETIC RESONANCE IMAGING PREDICTS CONTRACTILE RESERVE OF CHRONICALLY DYSFUNCTIONAL MYOCARDIUM: COMPARISON WITH FLUORINE-18 FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY

    2000-01-01

    Objective. This study sought to investigate whether low-dose dobutamine-MRI can detect residual myocardial viability in patients with chronic myocardial infarction and left ventricular dysfunction.Methods. Eleven patients with chronic myocardial infarction and left ventricular dysfunction were employed for identification of viable myocardium by cine-MRI during dobutamine infusion. All patients underwent coronary angiography and left ventriculography,18FDG-PET, MRI at rest and stress.The systolic wall thickening measured at rest and during stress was compared with the results of 18FDG- PET, respectively.Results. A significant difference of either dobutamine-induced systolic wall thickening (SWthstress) or dobutamine-induced contractile reserve (ΔSWth= SWthstress- SWthrest) was present between viable and scar regions (1.0±0.3 versus -0.3 ±0.1, P<0.01; 1.0±0.3 versus -0.2±0.2, P<0.01).

  16. Metabolic hyperfrontality and psychopathology in the ketamine model of psychosis using positron emission tomography (PET) and [F-18]fluorodeoxyglucose (FDG)

    Vollenweider, FX; Leenders, KL; Scharfetter, C; Antonini, A; Maguire, P; Missimer, J; Angst, J

    1997-01-01

    To date, the ketamine/PCP model of psychosis has been proposed to be one of the best pharmacological models to mimic schizophrenic psychosis in healthy volunteers, since ketamine can induce both positive and negative symptoms of schizophrenia. At subanesthetic doses, ketamine has been reported to pr

  17. Diagnosis of pancreatic cancer using fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET). Usefulness and limitations in clinical reality''

    The present review will provide an overview of the literature concerning the FDG PET diagnosis of pancreatic cancer and a summary from our experience of 231 cases of pancreatic lesions. FDG PET can effectively differentiate pancreatic cancer from benign lesion with high accuracy. Newly-developed PET scanners can detect small pancreatic cancers, up to 7 mm in diameter, by their high resolution, which could make a great contribution to the early detection of resectable and potentially curable pancreatic cancers. FDG PET is useful and cost-beneficial in the pre-operative staging of pancreatic cancer because an unexpected distant metastasis can be detected by whole-body PET in about 40% of the cases, which results in avoidance of unnecessary surgical procedures. FDG PET is also useful in evaluation of the treatment effect, monitoring after the operation and detection of recurrent pancreatic cancers. However, there are some drawbacks in PET diagnosis. A relatively wide overlap has been reported between semiquantitative uptake values obtained in cancers and those in inflammatory lesions. As for false-positive cases, active and chronic pancreatitis and autoimmune pancreatitis sometimes show high FDG accumulation and mimic pancreatic cancer with a shape of focal uptake. There were 8 false negative cases in the detection of pancreatic cancer by FDG PET, up to 33 mm in diameter, mainly because of their poor cellularity in cancer tissues. In addition, there are 19% of cancer cases with a decline in FDG uptake from 1 hr to 2 hr scan. FDG PET was recently applied to and was shown to be feasible in the differential diagnosis of cystic pancreatic lesions, such as intraductal papillary mucinous tumor of the pancreas. Further investigations are required to clarify the clinical value of FDG PET in predicting prognosis of the pancreatic patients. (author) 124 refs

  18. Positron emission tomography.

    Hoffman, E J; Phelps, M E

    1979-01-01

    Conventional nuclear imaging techniques utilizing lead collimation rely on radioactive tracers with little role in human physiology. The principles of imaging based on coincidence detection of the annihilation radiation produced in positron decay indicate that this mode of detection is uniquely suited for use in emission computed tomography. The only gamma-ray-emitting isotopes of carbon, nitrogen, and oxygen are positron emitters, which yield energies too high for conventional imaging techniques. Thus development of positron emitters in nuclear medicine imaging would make possible the use of a new class of physiologically active, positron-emitting radiopharmaceuticals. The application of these principles is described in the use of a physiologically active compound labeled with a positron emitter and positron-emission computed tomography to measure the local cerebral metabolic rate in humans. PMID:440173

  19. 18F-FDG Positron Emission Tomography – An Innovative Technique for the Diagnosis of a Canine Lameness

    Mann, Kelly; Hart, Juliette; Duerr, Felix

    2016-01-01

    Introduction Positron emission tomography (PET) imaging with fluorine-18-fluorodeoxyglucose (18F-FDG) is widely known for its use in the diagnosis and tracking of primary and metastatic tumors via uptake and retention of the radiopharmaceutical by hypermetabolic cells. 18F-FDG is also used to study the normal physiology of glucose uptake, metabolism, and muscle activity during and after exercise. Background A pilot study adding PET imaging to the diagnostic evaluation of canine patients under...

  20. Multifocal Head and Neck Paraganglioma Evaluated with Different PET Tracers: Comparison Between Fluorine-18-Fluorodeoxyglucose Between Fluorine-18-Fluorodeoxyglucose and Gallium-68-Somatostatin Receptor PET/CT

    Castaldi, Paola; Rufini, Vittoria [Catholic Univ. of the Sacred Heart, Rome (Italy); Treglia, G. [Oncology Institute of Southern Switzerland, Bellinzona (Switzerland)

    2013-09-15

    We report the case of a 46-year-old woman with a succinate dehydrogenase subtype D (SDHD) gene mutation and multifocal head and neck paraganglioma evaluated with fluorine-18-fluorodeoxyglucose and gallium-68-somatostatin receptor positron emission tomography/computed tomography (PET/CT). Gallium-68-somatostatin receptor PET/CT correctly assessed the extent of the disease in this patient, detecting additional lesions compared with fluorine-18-fluorodeoxyglucose PET/CT and influencing the patient management. A 46-year-old woman was referred to our centre for surveillance of a gastrointestinal stromal tumour (GIST). The patient underwent fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG-PET/CT), which demonstrated a focal area of increased radiopharmaceutical uptake corresponding to a lesion located between the right carotid vessels (yellow arrow; Fig. 1a). This F-18-FDG-PET/CT finding was suspicious for a paraganglioma of the neck. The patient underwent further examinations, including biochemical and genetic tests and a somatostatin receptor PET/CT using somatostatin analogues labelled with gallium-68 (Ga-68-DOTANOC-PET/CT). Laboratory data were suspicious for a non-functioning neuroendocrine tumour. Increased serum chromogranin A value and normal values of plasmatic and urinary catecholamines and their metabolites were found. The patient had no symptoms of a functioning tumour. Genetic tests demonstrated the presence of a succinate dehydrogenase subtype D (SDHD) gene mutation, which is associated with head and neck paragangliomas. Surprisingly, Ga-68-DOTANOC-PET/CT (Fig. 1b) showed multiple bilateral areas of increased radiopharmaceutical uptake in the head and neck region, corresponding to bilateral neuroendocrine lesions and suggesting the presence of bilateral paragangliomas (yellow arrows) with small cervical lymph nodal metastases with short axis less than 1 cm of diameter (red arrows). Physiological radiopharmaceutical

  1. Myocardial energy metabolism by positron emission tomography

    Positron emission tomography (PET) permits quantitative measurement of myocardial blood flow and metabolism in vivo in the cardiovascular areas. F-18 fluorodeoxyglucose (FDG) and C-11 palmitate have been used for energy metabolism in the cardiac PET. In fasting condition, beta-oxydation of fatty acids is the major energy source in the normal myocardium, whereas glucose metabolism is enhanced in the ischemic myocardium. No metabolic substrate is used in the necrotic myocardium. Thus, quantitative measurement of substrate utilization enables differentiation of ischemic from normal or infarcted myocardium and precise assessment of tissue abnormalities in vivo. FDG is administrated in fasting condition in our institute in order to delineate ischemic myocardium as a hot spot with suppression of the FDG uptake in the normal myocardium. However, when compared to the postprandial condition, FDG uptake may be enhanced even in the infarcted tissue, and thus, may possibly overestimate the tissue viability. A certain quantification of FDG uptake may be warranted for an accurate evaluation of FDG uptake. We have been measured FDG uptake index as a fraction of injected dose (% dose/100g tissue). This index correlated well with myocardial metabolic rate of glucose by Phelps method in the fasting condition. Dynamic PET study after C-11 palmitate injection has been used for estimate of fatty acid utilization. The first component of the washout from the myocardium is considered as rate of beta-oxydation. However, the washout of this tracer seems to be strikingly different between the fasting and postprandial conditions. (J.P.N.)

  2. Positron-emission tomography

    Positron-emission tomography (PET) combines early biochemical assessment of pathology achieved by nuclear medicine with the precise localization achieved by computerized image reconstruction. In this technique a chemical compound with the desired biological activity is labeled with a radioactive isotope that decays by emitting a positron, or positive electron. With suitable interpretation PET images can provide a noninvasive, regional assessment of many biochemical processes that are essential to the functioning of the organ that is being visualized

  3. Positron emission tomography: a new paradigm in cancer management

    The National Cancer Institute (NCI) is currently building a positron emission tomography facility that will house a cyclotron and a PET fusion scanner. lt should be operational as of december 2007, being a cancer dedicated national referral center, the NCI should provide both positron-emitting radiopharmaceuticals and medical services to institutions and patients nationwide. PET technology provides metabolic information that has been documented to be useful in patient care. The properties of positron decay allow accurate imaging of the in vivo distribution of positron-emitting radiopharmaceuticals. a wide array of positron-emitting radiopharmaceuticals has been used to characterize multiple physiologic and pathologic states. The major clinical PET applications are in cancer patients using fluorine-18 fluorodeoxyglucose (FDG). FDG, an analogue of glucose, accumulates in most tumors in a greater amount than it does in normal tissue. PET is being used in diagnosis and follow-up of several malignancies, and the list of articles supporting its use continues to grow. in this article, the instrumentation aspects of PET are described and most of the clinical applications in oncology are described

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

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

  5. Fluorodeoxyglucose positron emission tomography-computed tomography findings in a case of xanthogranulomatous pyelonephritis

    Xanthogranulomatous pyelonephritis (XGNP) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction. This condition can clinically present as recurrent urinary tract infections, flank pain, hematuria, and occasionally sepsis, and weight loss. This condition is usually associated with obstructing renal calculus. We present 18-fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET/CT) findings in an elderly male suffering from pyrexia and weight loss and suspected urinary tract infection. PET/CT findings in this case lead to diagnosis of XGNP. This diagnosis should be kept in mind while evaluating similar symptoms and PET/CT scan findings. (author)

  6. Positron emission tomography

    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)

  7. Positron emission tomography

    Paans, A M J

    2006-01-01

    Positron Emission Tomography (PET) is a method for measuring biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labelled with positron emitting radionuclides such as 11C, 13N, 15O and 18F and by measuring the annihilation radiation using a coincidence technique. This includes also the measurement of the pharmacokinetics of labelled drugs and the measurement of the effects of drugs on metabolism. Also deviations of normal metabolism can be measured and insight into biological processes responsible for diseases can be obtained. At present the combined PET/CT scanner is the most frequently used scanner for whole-body scanning in the field of oncology.

  8. Clinical utility of 18 Fluorodeoxyglucose (FDG-PET/CT scans in patients with suspect ocular tuberculosis

    Salil Mehta

    2013-01-01

    Full Text Available Systemic imaging of patients with suspect ocular tuberculosis include chest X-rays and computed tomography (CT scans. Reports have suggested a role for 18 fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT scans. We report on the clinical utility of 18 FDG PET/CT in two patients. Case 1: A 38-year-old female patient presented with recurrent anterior uveitis. A 18 FDG-PET scan revealed metabolically active supraclavicular and chest lymph nodes. An aspiration cytology of the cervical lymph node revealed caseating granulomas suggestive of tuberculosis. Case 2: A 58-year-old female patient presented with recurrent anterior uveitis. A 18 FDG-PET scan revealed metabolically active lymph nodes in the neck. A biopsy of the cervical lymph node revealed epithelioid granulomas suggestive of tuberculosis. Both patients were started on standard antitubercular therapy with a subsequent marked reduction of activity. PET/CT scans may suggest the sites of safe high-yield biopsies.

  9. Tomography by positrons emission

    The tomography by positrons emission is a technology that allows to measure the concentration of positrons emission in a tri dimensional body through external measurements. Among the isotope emissions have carbon isotopes are (11C), of the oxygen (15O), of the nitrogen (13N) that are three the element that constitute the base of the organic chemistry. Theses have on of the PET's most important advantages, since many biological interesting organic molecules can be tracer with these isotopes for the metabolism studies 'in vivo' through PET, without using organic tracers that modify the metabolism. The mentioned isotopes, also possess the characteristic of having short lifetime, that constitute on of PET's advantages from the dosimetric point of view. Among 11C, 15O, and 13N, other isotopes that can be obtained of a generator as the 68Ga and 82Rb

  10. Gene Expression Study in Positron Emission Tomography–Positive Abdominal Aortic Aneurysms Identifies CCL18 as a Potential Biomarker for Rupture Risk

    Courtois, Audrey; Nusgens-Richelle, Betty; Hustinx, Roland; Namur, Gauthier; Gomez, Pierre; Kuivaniemi, Helena; Defraigne, Jean-Olivier; Colige, Alain; Sakalihasan, Natzi

    2015-01-01

    Rupture of abdominal aortic aneurysm (AAA) is a cause of significant mortality and morbidity in ageing populations. Uptake of 18-fluorodeoxyglucose (FDG) detected by positron emission tomography (PET) is observed in the wall of 12% of AAA (A+), most of them being symptomatic. We previously showed that the metabolically active areas displayed adventitial inflammation, medial degeneration and molecular alterations prefacing wall rupture. The aim of this study was to identify new factors predict...

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

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

    2015-01-01

    Background: To evaluate the advantages of contrast enhanced F-18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-contrast enhanced CT [CECT]) when used as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin (MUO). Materials and Methods: A total of 243 patients with fine needle aspiration cytology/biopsy proven MUO were included in this prospective study. Patients who were thoroughly evaluated for primary or p...

  12. Positron emission tomography

    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 (11C), oxygen (15O), and nitrogen (13N) 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.)

  13. Positron Emission Mammography with Multiple Angle Acquisition

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

  14. Diagnostic utility of fluorodeoxyglucose positron emission tomography/computed tomography in pyrexia of unknown origin

    The present study was undertaken to evaluate the diagnostic utility of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in patients presenting as pyrexia of unknown origin (PUO). Forty-seven patients (31 males and 16 females; mean age of 42.7 ± 19.96 years) presenting as PUO to the Department of Medicine at the All India Institute of Medical Sciences, New Delhi over a period of 2 years underwent F-18 FDG PET/CT. PET ⁄ CT was considered supportive when its results correlated with the final definitive diagnosis. Final diagnosis was made on the basis of combined evaluation of history, clinical findings, investigations, and response to treatment. Thirty-five PET/CT studies (74.5%) were positive. However, only 18 (38.3%) were supportive of the final diagnosis. In three patients (6.4%), PET/CT was considered diagnostic as none of the other investigations including contrast-enhanced computed tomography of chest and abdomen, and directed tissue sampling could lead to the final diagnosis. All these three patients were diagnosed as aortoarteritis. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography is an important emerging modality in the workup of PUO. It supported the final diagnosis in 38% of our patients and was diagnostic in 6.4% of patients. Thus, PET/CT should only be considered as second-line investigation for the diagnostic evaluation of PUO; especially in suspected noninfectious inflammatory disorders

  15. Positron Emission Tomography (PET)

    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

  16. Multifocal Head and Neck Paraganglioma Evaluated with Different PET Tracers: Comparison Between Fluorine-18-Fluorodeoxyglucose Between Fluorine-18-Fluorodeoxyglucose and Gallium-68-Somatostatin Receptor PET/CT

    We report the case of a 46-year-old woman with a succinate dehydrogenase subtype D (SDHD) gene mutation and multifocal head and neck paraganglioma evaluated with fluorine-18-fluorodeoxyglucose and gallium-68-somatostatin receptor positron emission tomography/computed tomography (PET/CT). Gallium-68-somatostatin receptor PET/CT correctly assessed the extent of the disease in this patient, detecting additional lesions compared with fluorine-18-fluorodeoxyglucose PET/CT and influencing the patient management. A 46-year-old woman was referred to our centre for surveillance of a gastrointestinal stromal tumour (GIST). The patient underwent fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG-PET/CT), which demonstrated a focal area of increased radiopharmaceutical uptake corresponding to a lesion located between the right carotid vessels (yellow arrow; Fig. 1a). This F-18-FDG-PET/CT finding was suspicious for a paraganglioma of the neck. The patient underwent further examinations, including biochemical and genetic tests and a somatostatin receptor PET/CT using somatostatin analogues labelled with gallium-68 (Ga-68-DOTANOC-PET/CT). Laboratory data were suspicious for a non-functioning neuroendocrine tumour. Increased serum chromogranin A value and normal values of plasmatic and urinary catecholamines and their metabolites were found. The patient had no symptoms of a functioning tumour. Genetic tests demonstrated the presence of a succinate dehydrogenase subtype D (SDHD) gene mutation, which is associated with head and neck paragangliomas. Surprisingly, Ga-68-DOTANOC-PET/CT (Fig. 1b) showed multiple bilateral areas of increased radiopharmaceutical uptake in the head and neck region, corresponding to bilateral neuroendocrine lesions and suggesting the presence of bilateral paragangliomas (yellow arrows) with small cervical lymph nodal metastases with short axis less than 1 cm of diameter (red arrows). Physiological radiopharmaceutical

  17. Optimal metabolic conditions during fluorine-18 fluorodeoxyglucose imaging; a comparative study using different protocols

    Bax, J.J. [Department of Cardiology, Free University Hospital Amsterdam (Netherlands); Veening, M.A. [Department of Cardiology, Free University Hospital Amsterdam (Netherlands); Visser, F.C. [Department of Cardiology, Free University Hospital Amsterdam (Netherlands); Lingen, A. van [Department of Nuclear Medicine, Free University Hospital Amsterdam (Netherlands); Heine, R.J. [Department of Internal Medicine, Free University Hospital Amsterdam (Netherlands); Cornel, J.H. [Department of Cardiology, Free University Hospital Amsterdam (Netherlands); Visser, C.A. [Department of Cardiology, Free University Hospital Amsterdam (Netherlands)

    1997-01-01

    Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) can identify viable myocardium in patients with coronary artery disease. Recently, FDG imaging with single-photon emission tomography (SPET) and 511-keV collimators has been described. To obtain optimal image quality in all patients, cardiac FDG studies should be performed during hyperinsulinaemic glucose clamping. It has been suggested that FDG imaging after the administration of a nicotinic acid derivative may yield comparable image quality to clamping. We studied eight patients and compared the image quality of cardiac FDG SPET studies after oral glucose loading, after administration of a nicotinic acid derivative (acipimox, 250 mg orally) and during hyperinsulinaemic glucose clamping. The image quality was expressed as the myocardial to blood pool (M/B) activity ratio, which is used as a measure of the target-to-background ratio The M/B ratios were comparable after clamping and acipimox (2.8{+-}0.8 vs 2.9{+-}0.7), whereas the M/B ratio was lower after oral glucose loading (2.2{+-}0.3, P<0.05 vs clamp and acipimox). To determine the clearance of FDG from the plasma, blood samples were drawn at fixed time intervals and the FDG activity was measured in a gamma well counter. The FDG clearance was significantly lower after oral glucose loading (T{sub 1/2}oral load=16.2 {+-}5.7 min) as compared with clamping (T {sub 1/2}clamp=8.1 {+-}3.1 min) and acipimox (T {sub 1/2}acipimox=10.7 {+-}4.0 min, NS vs clamp, P <0.05 vs oral load). It may be concluded that FDG SPET imaging after acipimox administration yields image quality and clearance rates comparable to those obtained during clamping. FDG SPET in combination with acipimox may useful in clinical routine for the assessment of myocardial viability. (orig.). With 6 figs., 3 tabs.

  18. Optimal metabolic conditions during fluorine-18 fluorodeoxyglucose imaging; a comparative study using different protocols

    Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) can identify viable myocardium in patients with coronary artery disease. Recently, FDG imaging with single-photon emission tomography (SPET) and 511-keV collimators has been described. To obtain optimal image quality in all patients, cardiac FDG studies should be performed during hyperinsulinaemic glucose clamping. It has been suggested that FDG imaging after the administration of a nicotinic acid derivative may yield comparable image quality to clamping. We studied eight patients and compared the image quality of cardiac FDG SPET studies after oral glucose loading, after administration of a nicotinic acid derivative (acipimox, 250 mg orally) and during hyperinsulinaemic glucose clamping. The image quality was expressed as the myocardial to blood pool (M/B) activity ratio, which is used as a measure of the target-to-background ratio The M/B ratios were comparable after clamping and acipimox (2.8±0.8 vs 2.9±0.7), whereas the M/B ratio was lower after oral glucose loading (2.2±0.3, P1/2oral load=16.2 ±5.7 min) as compared with clamping (T 1/2clamp=8.1 ±3.1 min) and acipimox (T 1/2acipimox=10.7 ±4.0 min, NS vs clamp, P <0.05 vs oral load). It may be concluded that FDG SPET imaging after acipimox administration yields image quality and clearance rates comparable to those obtained during clamping. FDG SPET in combination with acipimox may useful in clinical routine for the assessment of myocardial viability. (orig.). With 6 figs., 3 tabs

  19. Positron emission mammography imaging

    Moses, William W.

    2003-10-02

    This paper examines current trends in Positron Emission Mammography (PEM) instrumentation and the performance tradeoffs inherent in them. The most common geometry is a pair of parallel planes of detector modules. They subtend a larger solid angle around the breast than conventional PET cameras, and so have both higher efficiency and lower cost. Extensions to this geometry include encircling the breast, measuring the depth of interaction (DOI), and dual-modality imaging (PEM and x-ray mammography, as well as PEM and x-ray guided biopsy). The ultimate utility of PEM may not be decided by instrument performance, but by biological and medical factors, such as the patient to patient variation in radiotracer uptake or the as yet undetermined role of PEM in breast cancer diagnosis and treatment.

  20. Positron emission tomography. Basic principles

    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

  1. Quantitative evaluation of regional substrate metabolism in the human heart by positron emission tomography

    Meaning interpretation of metabolic images obtained by positron emission tomography for evaluation of cardiac disease requires a knowledge of the normal variation in regional myocardial substrate metabolism. Recent studies with fluorine-18 (F-18) fluorodeoxyglucose suggest inhomogeneity of myocardial glucose metabolism in the normal human heart, which may relate to substrate availability. Therefore, quantitative evaluation of myocardial oxidative metabolism and glucose metabolism, as derived by dynamic positron emission tomography with carbon-11 (C-11) acetate and F-18 fluorodeoxyglucose, was performed in nine healthy male volunteers. All were studied under tightly controlled metabolic conditions of hyperinsulinemic-euglycemic clamping with and without a concurrent lipid emulsion infusion. Significant inhomogeneity of regional glucose metabolism was noted although it was less than that described under fasting conditions. Glucose utilization was 13% lower in the septum compared with the lateral wall both without and with lipid infusion (0.34 vs. 0.39 mumol/g per min, respectively, p less than 0.05; and 0.33 vs. 0.38 mumol/g per min, respectively, (p less than 0.05)). Relatively decreased septal glucose utilization could not be explained by decreased metabolic demand because C-11 clearance constants were marginally higher in the septum than in the lateral wall in both studies (0.055 vs. 0.054 per min, respectively, p = NS; and 0.061 vs. 0.056 per min, respectively,(p less than 0.05)). Relatively decreased septal glucose utilization could reflect regional variation in substrate use and possible preferential free fatty acid utilization by the septum. These data provide a useful framework for assessing altered cardiac metabolism in disease and support standardization of metabolic conditions during metabolic imaging with positron emission tomography

  2. Quantitative evaluation of regional substrate metabolism in the human heart by positron emission tomography

    Hicks, R.J.; Herman, W.H.; Kalff, V.; Molina, E.; Wolfe, E.R.; Hutchins, G.; Schwaiger, M. (Department of Internal Medicine, University of Michigan Hospitals, Ann Arbor (USA))

    1991-07-01

    Meaning interpretation of metabolic images obtained by positron emission tomography for evaluation of cardiac disease requires a knowledge of the normal variation in regional myocardial substrate metabolism. Recent studies with fluorine-18 (F-18) fluorodeoxyglucose suggest inhomogeneity of myocardial glucose metabolism in the normal human heart, which may relate to substrate availability. Therefore, quantitative evaluation of myocardial oxidative metabolism and glucose metabolism, as derived by dynamic positron emission tomography with carbon-11 (C-11) acetate and F-18 fluorodeoxyglucose, was performed in nine healthy male volunteers. All were studied under tightly controlled metabolic conditions of hyperinsulinemic-euglycemic clamping with and without a concurrent lipid emulsion infusion. Significant inhomogeneity of regional glucose metabolism was noted although it was less than that described under fasting conditions. Glucose utilization was 13% lower in the septum compared with the lateral wall both without and with lipid infusion (0.34 vs. 0.39 mumol/g per min, respectively, p less than 0.05; and 0.33 vs. 0.38 mumol/g per min, respectively, (p less than 0.05)). Relatively decreased septal glucose utilization could not be explained by decreased metabolic demand because C-11 clearance constants were marginally higher in the septum than in the lateral wall in both studies (0.055 vs. 0.054 per min, respectively, p = NS; and 0.061 vs. 0.056 per min, respectively,(p less than 0.05)). Relatively decreased septal glucose utilization could reflect regional variation in substrate use and possible preferential free fatty acid utilization by the septum. These data provide a useful framework for assessing altered cardiac metabolism in disease and support standardization of metabolic conditions during metabolic imaging with positron emission tomography.

  3. Modest utility of quantitative measures in F-18-fluorodeoxyglucose positron emission tomography scanning for the diagnosis of aortic prosthetic graft infection

    Saleem, Ben R.; Berger, Paul; Vaartjes, Ilonca; de Keizer, B; Vonken, EPA; Slart, Riemer H. J. A.; de Borst, Gert Jan; Zeebregts, Clark J.

    2015-01-01

    Background: The clinical dilemma in suspected aortic graft infection (AGI) is how to noninvasively obtain a reliable proof of infection. In addition to confirming the presence of infection, obtaining information regarding the extent of infection to select a proper strategy for reoperation is also ne

  4. Differentiation of medial or lateral temporal lobe epilepsy by F-18-fluorodeoxyglucose positron emission tomography: comparative study with magnetic resonance imaging in 113 surgically and pathologically proven patients

    As mesial temporal lobe epilepsy (TLE) shows hypometabolism of medial and lateral temporal lobe, we investigated whether symmetric uptake of F-18-FDG in medial temporal lobes can differentiate mesial from lateral TLE. In 113 patients (83 mesial TLE, 30 lateral TLE) who underwent anterior temporal lobectomy and/or corticectomy with good surgical outcome, we performed F-18-FDG PET and compared F-18-FDG uptake of medial and lateral temporal lobes. All the patients with mesial TLE had hippocampal sclerosis except one congenital abnormal hippocampus. Patients with lateral TLE revealed cerebromalacia, microdysgenesis, arteriovenous malformation, old contusion, and cortical dysplasia. Sensitivity of F-18-FDG PET and MR for mesial TLE was 84% (70/83) and 73% (62/83), respectively. Sensitivity of F-18-FDG PET and MR for lateral TLE was 90% (27/30) and 66% (20/30), respectively. Twelve patients were normal on F-18-FDG PET. 101 patients had hypometabolism of lateral temporal lobe. Among 88 patients who showed hypometabolism of medial temporal lobe as well as lateral temporal lobe, 70 were mesial TLE patients and 18 were lateral TLE on pathologic examination. Positive predictive value of medial temporal hypometabolism for mesial TLE was 80%. Among 13 patients who showed hypometabolism of only lateral temporal lobe, 4 were mesial TLE and 9 were lateral TLE. Positive predictive value of hypometabolism of lateral temporal lobe for the diagnosis of lateral TLE was 69% (9/ 13). Normal MR findings stood against medial TLE, whose negative predictive value was 66%. Lateral temporal lobe epilepsy should be suspected when there is decreased F-18-FDG uptake in lateral temporal lobe with normal uptake in medial temporal lobe

  5. Fluorine-18-fluorodeoxyglucose positron emission tomography (PET) brain imaging patterns in patients with suspected X-linked dystonia parkinsonism (study in progress)

    Objective: X-linked dystonia-parkinsonism (XDP or Lubag) is an adult-onset dystonia syndrome that afflicts mostly Filipino men from the island of Panay, Philippines.It starts focally and becomes generalized or multifocal after the first five years. Parkinsonism is commonly encountered as the initial symptom before the onset of dystonia. Patients may manifest a wide spectrum of movement disorders, including myoclonus, chorea, akathisia, ballism and myorhythmia. Diagnosis is based on the clinical presentation, and the establishment of an x-linked recessive pattern of inheritance and maternal roots from the Panay Islands. Neuroimaging in advanced cases have demonstrated caudate and putaminal atrophy. Previous studies using PET have shown selective reduction in normalized striatal glucose metabolism. The purpose of this study is to describe the FDG distribution using PET imaging in Filipino patients with suspected or confirmed Lubag in various stages of their disease in order to determine if FDG-PET can be used in the initial diagnosis and staging of the disease. Methods and results: All patients presenting to the Movement Disorders Center of St. Lukes Medical Center with dystonia and Parkinsonism symptoms with X-linked recessive inheritance pattern and maternal roots traceable to the Panay Islands were sent for a Brain FDG PET Scan. Seven male patients with various movement disorders (dysarthria, face dystonia, Parkinsonism, hemibalismus, involuntary movements and rest tremors) with duration of symptoms from 1 to 5 years underwent a PET scan. All patients had non visualized bilateral putamen, four had hypometabolic caudate nuclei, one had intense (hypermetabolic) caudate nuclei. CT scan and MRI did not show any findings which may explain the movement disorder symptoms. More patients are being collected and gene typing is planned for some patients. Conclusions: This small series of patients demonstrate that patients with the phenotypic characteristics of X-linked Dystonia Parkinsonism have poor glucose metabolism in the putamen and various degrees of decreased glucose metabolism in the caudate nuclei. FDG-PET may help in the diagnosis of movement disorders especially in those whose CT and MRI do not show any significant abnormality. (authors)

  6. Fluorine F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for restaging of non small cell lung cancer (NSCLC): analysis of management change and survival in 63 consecutive patients

    Full text: Following treatment with curative intent for non small cell lung cancer (NSCLC), assessment of disease status using conventional techniques is often difficult. We evaluated management impact and prognostic value of FDG PET in 63 consecutive patients undergoing restaging of NSCLC between 11/96 and 12/98. All patients were >6 months from primary treatment with curative intent. Salvage therapy with curative intent was being contemplated in 18 patients. Conventional imaging was abnormal 61/63 patients, two others had recurrent symptoms only. Compared to conventional restaging, 33% of patients were down-staged, and 35% were upstaged by PET. PET led to more aggressive treatment than planned in 7 patients (11%), a change from planned curative to palliative treatment in 8 patients (13%) and 17 patients (27%) thought to have recurrent disease had no further investigation or treatment after negative PET studies. Cox proportional hazards analysis indicated that a positive PET scan had a hazard ratio of 2.95 (95% CI 1.038.50, p = 0.012) compared to negative PET. Extent of active disease on PET was also prognostically significant with each incremental extent category (no disease, local recurrence, limited locoregional, extensive locoregional and systemic) having an estimated 60% increase in the rate of death (95% Cl 24% to 107%, p<0.0001). Stage of disease at initial diagnosis, primary treatment used and disease extent on conventional restaging were not predictive of survival. Thus, PET provided a high impact on management for NSCLC patients with suspected recurrence and more accurate prognostic stratification than conventional staging. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  7. Estimation of absorbed doses in humans due to intravenous administration of fluorine-18-fluorodeoxyglucose in PET studies

    Radiation absorbed doses due to intravenous administration of fluorine-18-fluorodeoxyglucose in positron emission tomography (PET) studies were estimated in normal volunteers. The time-activity curves were obtained for seven human organs (brain, heart, kidney, liver, lung, pancreas, and spleen) by using dynamic PET scans and for bladder content by using a single detector. These time-activity curves were used for the calculation of the cumulative activity in these organs. Absorbed doses were calculated by the MIRD method using the absorbed dose per unit of cumulated activity, 'S' value, transformed for the Japanese physique and the organ masses of the Japanese reference man. The bladder wall and the heart were the organs receiving higher doses of 1.2 x 10(-1) and 4.5 x 10(-2) mGy/MBq, respectively. The brain received a dose of 2.9 x 10(-2) mGy/MBq, and other organs received doses between 1.0 x 10(-2) and 3.0 x 10(-2) mGy/MBq. The effective dose equivalent was estimated to be 2.4 x 10(-2) mSv/MBq. These results were comparable to values of absorbed doses reported by other authors on the radiation dosimetry of this radiopharmaceutical

  8. Fundamentals of positron emission tomography

    Positron emission tomography is a modern radionuclide method of measuring physiological quantities or metabolic parameters in vivo. The methods is based on: (1) Radioactive labelling with positron emitters; (2) the coincidence technique for the measurement of the annihilation radiation following positron decay; (3) analysis of the data measured using biological models. The basic aspects and problems of the method are discussed. The main fields of future research are the synthesis of new labelled compounds and the development of mathematical models of the biological processes to be investigated. (orig.)

  9. [Fundamentals of positron emission tomography].

    Ostertag, H

    1989-07-01

    Positron emission tomography is a modern radionuclide method of measuring physiological quantities or metabolic parameters in vivo. The method is based on: (1) radioactive labelling with positron emitters; (2) the coincidence technique for the measurement of the annihilation radiation following positron decay; (3) analysis of the data measured using biological models. The basic aspects and problems of the method are discussed. The main fields of future research are the synthesis of new labelled compounds and the development of mathematical models of the biological processes to be investigated. PMID:2667029

  10. Post-traumatic diaphragmatic herniation of the liver, examined by positron emission tomography: case report

    Chatani Naru

    2011-08-01

    Full Text Available Abstract We present a case of post-traumatic diaphragmatic herniation of the liver, which mimicked an intrathoracic tumor. After an automobile accident, the patient underwent thoracotomies for hemothorax and lung cancer in the right chest. Seven months later, computed tomography (CT demonstrated a round tumor in the thorax adjacent to the right diaphragm with a higher density than the liver parenchyma. An intrathoracic tumor including a primary or metastatic lung cancer was suspected. However, positron emission tomography (PET showed that the uptake of fluorine-18-fluorodeoxyglucose (FDG was identical to that in the liver, and the tumor appeared to be contiguous with the liver. Thus, we suspected liver herniation. Core needle biopsy revealed liver cells without neoplastic tissue. Upon surgical exploration, herniation of the liver was found and repaired. PET was helpful in providing morphological and functional information leading to accurate diagnosis of liver herniation in this unusual case.

  11. Design And Development Of A Mammary And Axillary Region Positron Emission Tomography System (maxpet)

    Doshi, N K

    2000-01-01

    Breast cancer is the second leading cause of cancer death in women. Currently, mammography and physical breast examination, both non-invasive techniques, provide the two most effective methods available for screening potential breast cancer patients. During the management of patients, however, several invasive techniques such as axillary lymph node dissection, core biopsies and lumpectomies, are utilized to determine the stage or malignancy of the disease with significant cost and morbidity associated with them. Positron Emission Tomography (PET), using [F-18] fluorodeoxyglucose (FDG) tracer is a sensitive and non-invasive imaging modality that may be a cost-effective alternative to certain invasive procedures. In this project we have developed a low cost, high performance, dedicated PET camera (maxPET) for mammary and axillary region imaging. The system consists of two 15x15 cm2 planar scintillation detector arrays composed of modular detectors operating in coincidence. The modular detectors are comprised of...

  12. Positron emission tomography with [{sup 18}F]FDG for therapy response monitoring in lymphoma patients

    Spaepen, Karoline; Stroobants, Sigrid; Mortelmans, Luc [Department of Nuclear Medicine, UZ Gasthuisberg, Herestraat 49, 3000, Leuven (Belgium); Verhoef, Gregor [Department of Hematology, UZ Gasthuisberg, Herestraat 49, 3000, Leuven (Belgium)

    2003-06-01

    Lymphomas are a heterogeneous group of diseases with differing histopathology, clinical behaviour, response to therapy and outcome. Lymphomas are highly sensitive to chemotherapy and radiotherapy, and the recent developments in treatment have considerably improved clinical outcome. However, there is increasing recognition that this has been at the cost of long-term treatment-related effects in a relatively young patient population. Thus, one of the most challenging aspects in the imaging of lymphoma patients is tailoring the intensity of the treatment to the individual patient. This paper reviews recently published data concerning the use of fluorine-18 fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG-PET) for therapy monitoring in lymphoma patients and highlights the shortcomings and future directions. A temporary strategy for the implementation of [{sup 18}F]FDG-PET in the management of lymphoma patients is proposed. (orig.)

  13. NMF on positron emission tomography

    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 is...

  14. Fluorine-18-fluorodeoxyglucose PET/CT for the evaluation of suspected recurrent uterine leiomyosarcomas

    Background Uterine leiomyosarcomas are rare and aggressive malignancies of the uterine corpus with high recurrence rates and poor prognoses. The current recommendation for detection of recurrent uterine leiomyosarcoma involves periodic physical examination and conventional imaging such as CT or MRI. The role of fluorine-18-fluorodeoxyglucose positron emission tomography with integrated computed tomography (FDG-PET/CT) in the detection of recurrent uterine leiomyosarcomas is not yet established. Purpose To evaluate the use of FDG-PET/CT as a single integrated modality for the evaluation of suspected recurrent uterine leiomyosarcomas. Material and Methods A retrospective study was performed on patients who underwent FDG-PET/CT scans for suspected recurrent uterine leiomyosarcoma. Only patients with follow-up data were included in the study. FDG-PET/CT was evaluated as a single integrated imaging modality. A positive lesion on FDG-PET/CT was defined as a focal abnormality detected on either the PET or CT components, or both. Results Sixteen consecutive patients over 5 years underwent FDG-PET/CT for suspected recurrent uterine leiomyosarcoma. Five patients were excluded due to incomplete follow-up data. The remaining 11 patients were aged 36-58 years (mean age 48). FDG-PET/CT had a sensitivity of 100% (95% CI 63-100) and specificity of 100% (95% CI 20-100) for the detection of recurrent uterine leiomyosarcomas. Sites of metastases include lungs, peritoneum, liver, pancreas and breast, of which lungs and peritoneum were the most common. Two (18%) patients had discordant findings: FDG-PET negative metastatic nodules in the breast and lung detected on the CT component. The maximum standardized uptake value (SUVmax) of metastatic lesions ranged from 2.0 to 16.0 (mean 7.6). Conclusion FDG-PET/CT as a single integrated modality may be a useful for the evaluation of suspected recurrent uterine leiomyosarcomas. FDG-PET negative discordant nodules detected on the CT component

  15. Fluorine-18-fluorodeoxyglucose PET/CT for the evaluation of suspected recurrent uterine leiomyosarcomas

    Kao, Yung Hsiang; Saad, U.; Tan, Andrew E.H.; Magsombol, Butch M.; Padhy, Ajit Kumar (Dept. of Nuclear Medicine and PET, Singapore General Hospital (Singapore)), email: kao.yung.hsiang@singhealth.com.sg

    2011-05-15

    Background Uterine leiomyosarcomas are rare and aggressive malignancies of the uterine corpus with high recurrence rates and poor prognoses. The current recommendation for detection of recurrent uterine leiomyosarcoma involves periodic physical examination and conventional imaging such as CT or MRI. The role of fluorine-18-fluorodeoxyglucose positron emission tomography with integrated computed tomography (FDG-PET/CT) in the detection of recurrent uterine leiomyosarcomas is not yet established. Purpose To evaluate the use of FDG-PET/CT as a single integrated modality for the evaluation of suspected recurrent uterine leiomyosarcomas. Material and Methods A retrospective study was performed on patients who underwent FDG-PET/CT scans for suspected recurrent uterine leiomyosarcoma. Only patients with follow-up data were included in the study. FDG-PET/CT was evaluated as a single integrated imaging modality. A positive lesion on FDG-PET/CT was defined as a focal abnormality detected on either the PET or CT components, or both. Results Sixteen consecutive patients over 5 years underwent FDG-PET/CT for suspected recurrent uterine leiomyosarcoma. Five patients were excluded due to incomplete follow-up data. The remaining 11 patients were aged 36-58 years (mean age 48). FDG-PET/CT had a sensitivity of 100% (95% CI 63-100) and specificity of 100% (95% CI 20-100) for the detection of recurrent uterine leiomyosarcomas. Sites of metastases include lungs, peritoneum, liver, pancreas and breast, of which lungs and peritoneum were the most common. Two (18%) patients had discordant findings: FDG-PET negative metastatic nodules in the breast and lung detected on the CT component. The maximum standardized uptake value (SUVmax) of metastatic lesions ranged from 2.0 to 16.0 (mean 7.6). Conclusion FDG-PET/CT as a single integrated modality may be a useful for the evaluation of suspected recurrent uterine leiomyosarcomas. FDG-PET negative discordant nodules detected on the CT component

  16. Brazilian experience in characterization of solitary pulmonary nodules using 18-fluorodeoxyglucose on camera-based PET

    Introduction: Positron emission tomography (PET) using 18-fluorodeoxyglucose (18F-FDG), showing increased 18F-FDG uptake and retention in malignant cells, has proved useful to differentiate malignant from benign pulmonary nodules. An accurate diagnosis of pulmonary cancer represents a clinical challenge. This could be even more significant in Latin America, where the incidence of infectious granulomas is high. However, the high cost of dedicated- PET studies has prevented widespread application of this technique. Hybrid PET is a new approach to tumor imaging using 18F-FDG. In our country, such a system was introduced in 1998. These systems offer the possibility to produce diagnostic quality images of 18F-FDG body distribution, making metabolic scans potentially available. Objective : The aim of this study was to determine the diagnostic value of F-18-FDG scan using a hybrid PET in characterizing pulmonary nodules as benign or malignant. Methods: We evaluated 62 patients (50 male, 38-79y) with indeterminate solitary pulmonary nodules after computed tomography (CT) screening. 18F-FDG scans were performed on a camera-based PET (MCD Vertex-plus Adac) after injection of 18-F-fluorodeoxyglucose intravenously. Image acquisition began after 1 hour. Qualitative analysis of the images was performed by visual identification of areas of increase (positive) or absence (negative)of FDG uptake. All results were assessed on basis of histology or clinical/radiological follow-up. Results : Twenty-one patients (33.9%) showed a marked increase in FDG uptake and underwent invasive intervention (biopsy or thoracotomy). Histopathological evaluation revealed malignant disease in eighteen of these patients and benign disease in three of them (positive predictive value = 85.7%). Forty-one patients (66.1%) showed absence of FDG uptake. Fourteen of them underwent surgical procedure. Malignancy was found in only one. Twenty-seven patients with negative FDG studies are being followed up with a

  17. Instrumentation in positron emission tomography

    Positron emission tomography (PET) is a three-dimensional medical imaging technique that noninvasively measures the concentration of radiopharmaceuticals in the body that are labeled with positron emitters. With the proper compounds, PET can be used to measure metabolism, blood flow, or other physiological values in vivo. The technique is based on the physics of positron annihilation and detection and the mathematical formulations developed for x-ray computed tomography. Modern PET systems can provide three-dimensional images of the brain, the heart, and other internal organs with resolutions on the order of 4 to 6 mm. With the selectivity provided by a choice of injected compounds, PET has the power to provide unique diagnostic information that is not available with any other imaging modality. This is the first five reports on the nature and uses of PET that have been prepared for the American Medical Association's Council on Scientific Affairs by an authoritative panel

  18. Evaluation of the limits of visual detection of image misregistration in a brain fluorine-18 fluorodeoxyglucose PET-MRI study

    In routine clinical work, registration accuracy is assessed by visual inspection. However, the accuracy of visual assessment of registration has not been evaluated. This study establishes the limits of visual detection of misregistration in a registered brain fluorine-18 fluorodeoxyglucose positron emission tomography to magnetic resonance image volume. The ''best'' registered image volume was obtained by automatic registration using mutual information optimization. Translational movements by 1 mm, 2 mm, 3 mm and 4 mm, and rotational movements by 1 , 2 , 3 and 4 in the positive and negative directions in the x- (lateral), y- (anterior-posterior) and z- (axial) axes were introduced to this standard. These 48 images plus six ''best'' registered images were presented in random sequence to five observers for visual categorization of registration accuracy. No observer detected a definite misregistration in the ''best'' registered image. Evaluation for inter-observer variation using observer pairings showed a high percentage of agreement in assigned categories for both translational and rotational misregistrations. Assessment of the limits of detection of misregistration showed that a 2-mm translational misregistration was detectable by all observers in the x- and y-axes and 3-mm translational misregistration in the z-axis. With rotational misregistrations, rotation around the z-axis was detectable by all at 2 rotation whereas rotation around the y-axis was detected at 3-4 . Rotation around the x-axis was not symmetric with a positive rotation being identified at 2 whereas negative rotation was detected by all only at 4 . Therefore, visual analysis appears to be a sensitive and practical means to assess image misregistration accuracy. The awareness of the limits of visual detection of misregistration will lead to increase care when evaluating registration quality in both research and clinical settings. (orig.). With 6 figs., 3 tabs

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

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

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

    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. PMID:27095862

  1. Are We Ready for Positron Emission Tomography/Computed Tomography-based Target Volume Definition in Lymphoma Radiation Therapy?

    Fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) has become indispensable for the clinical management of lymphomas. With consistent evidence that it is more accurate than anatomic imaging in the staging and response assessment of many lymphoma subtypes, its utility continues to increase. There have therefore been efforts to incorporate PET/CT data into radiation therapy decision making and in the planning process. Further, there have also been studies investigating target volume definition for radiation therapy using PET/CT data. This article will critically review the literature and ongoing studies on the above topics, examining the value and methods of adding PET/CT data to the radiation therapy treatment algorithm. We will also discuss the various challenges and the areas where more evidence is required.

  2. Preoperative assessment of cervical lymph nodes in head and neck cancer with fluorine-18 fluorodeoxyglucose using a dual-head coincidence camera: a pilot study

    The aim of this study was to investigate whether in patients with head and neck cancer, staging is possible with fluorine-18 fluorodeoxyglucose (18F-FDG) using a dual-head positron emission tomography (PET) camera. Twenty patients (ten men, ten women; mean age: 60 years) were studied using 185 MBq (5 mCi) 18F-FDG. Two of these patients who were suspected of having recurrence in the neck were restaged 19 and 12 months, respectively, after the resection of the primary tumour. The images were visually analyzed and the results were correlated with computed tomography (CT) (n = 18), ultrasonography (n = 17) and pathological findings. With respect to the primary tumour, FDG dual-head PET and CT revealed a sensitivity of 100% and 59%, respectively (P18F-FDG with a dual-head PET camera is very sensitive in the detection of primary head and neck cancers and accurate in the preoperative assessment of lymph node metastases. The results justify a prospective study on the identification of metastases in patients with head and neck cancer. In addition, it is justified to start a study on the detection of unknown primary tumours in patients with cervical metastases. (orig.)

  3. Positron emission tomography and migraine

    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 HT2 serotonin receptors can be studied in migraine patients with PET

  4. Positron emission tomography wrist detector

    Schlyer, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois

    2006-08-15

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal representing a time-of-occurrence of an annihilation event, generating an address signal representing a channel detecting the annihilation event, and generating a channel signal including the time and address signals. The method also includes generating a composite signal including the channel signal and another similarly generated channel signal concerning another annihilation event. An apparatus that serially transfers annihilation information includes a time signal generator, address signal generator, channel signal generator, and composite signal generator. The time signal is asynchronous and the address signal is synchronous to a clock signal. A PET scanner includes a scintillation array, detection array, front-end array, and a serial encoder. The serial encoders include the time signal generator, address signal generator, channel signal generator, and composite signal generator.

  5. Positron emission tomography basic sciences

    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...

  6. Scintillators for positron emission tomography

    Like most applications that utilize scintillators for gamma detection, Positron Emission Tomography (PET) desires materials with high light output, short decay time, and excellent stopping power that are also inexpensive, mechanically rugged, and chemically inert. Realizing that this ''ultimate'' scintillator may not exist, this paper evaluates the relative importance of these qualities and describes their impact on the imaging performance of PET. The most important PET scintillator quality is the ability to absorb 511 keV photons in a small volume, which affects the spatial resolution of the camera. The dominant factor is a short attenuation length (≤ 1.5 cm is required), although a high photoelectric fraction is also important (> 30% is desired). The next most important quality is a short decay time, which affects both the dead time and the coincidence timing resolution. Detection rates for single 511 keV photons can be extremely high, so decay times ≤ 500 ns are essential to avoid dead time losses. In addition, positron annihilations are identified by time coincidence so ≤5 ns fwhm coincidence pair timing resolution is required to identify events with narrow coincidence windows, reducing contamination due to accidental coincidences. Current trends in PET cameras are toward septaless, ''fully-3D'' cameras, which have significantly higher count rates than conventional 2-D cameras and so place higher demands on scintillator decay time. Light output affects energy resolution, and thus the ability of the camera to identify and reject events where the initial 511 keV photon has undergone Compton scatter in the patient. The scatter to true event fraction is much higher in fully-3D cameras than in 2-D cameras, so future PET cameras would benefit from scintillators with a 511 keV energy resolution < 10--12% fwhm

  7. Positron emission tomography in epilepsy

    Positron emission tomography (PET) was performed with the 18F-fluoro-deoxy-glucose method on 29 patients with epilepsy (generalized epilepsy, 4; partial epilepsy, 24; undetermined type, 1). The subjects were restricted to patients with epilepsy without focal abnormality on X-CT. All the patients with generalized epilepsy showed a normal pattern on PET. Fourteen out of the 24 patients with partial epilepsy and the 1 with epilepsy of undermined type showed focal hypometabolism on PET. The hypometabolic zone was localized in areas including the temporal cortex in 11 patients, frontal in 2 and thalamus in 1. The location of hypometabolic zone and that of interictal paroxysmal activity on EEG were well correlated in most patients. The patients with poorly-controlled seizure showed a higher incidence of PET abnormality (12 out of 13) than those with well-controlled seizures (2 out of 11). The incidence of abnormality on PET and MRI and the location of both abnormality were not necessarily coincident. These results indicated that the PET examination in epilepsy provides valuable information about the location of epileptic focus, and that the findings on PET in patients with partial epilepsy may be one of the good indicators about the intractability of partial epilepsy, and that PET and MRI provide complementary information in the diagnosis of epilepsy. (author)

  8. Diagnosis of tumor and inflammation in the chest by positron emission tomography

    Hara, Toshihiko; Kosaka, Noboru; Kudo, Koichiro; Arai, Takashi; Fujii, Kyoichi; Kabe, Junzaburo [International Medical Center, Tokyo (Japan)

    1996-12-01

    Positron emission tomography (PET) utilizing =fluorine-18=-fluorodeoxyglucose (FDG) has been shown to be highly accurate in differentiating benign from malignant pulmonary tumors. Our hospital started the PET clinics very recently. The FDG-PET for lung tumor diagnosis has been included in the menu of services from the beginning of this clinics. Our objective in this paper is to determine how effectively the FDG-PET reveals the nature of the tumor in the chest in relation to CT, tansthoracic fine-needle biopsy, and thoracotomy. Sixteen patients with lung lesions who had undergone PET were selected retrospectively as eligible for pathological justification. All the 14 cases of lung cancer showed highly positive uptake of FDG relative to the normal lung tissue. One case of benign tumor, one case of scarred aterectasis showed negative uptake. One case of active form of tuberculosis showed high uptake. Five lymph node stations in 3 cases were revealed to be the metastasized lymph nodes pathologically. FDG-PET visualized all of them. Absence of lymph node metastasis was confirmed in 7 cases. FDG-PET gave them negative results. (author)

  9. Lymph node metastasis of squamous cell carcinoma from an unknown primary: impact of positron emission tomography

    This study was performed to assess the potential benefit of positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (FDG) in patients with cervical metastasis of squamous cell carcinoma from an unknown primary tumour. Eighteen patients with cervical metastasis of squamous cell carcinoma from an unknown primary who were assessed by physical examination including transnasal fibre-endoscopy and radiological work-up with computed tomography were included in this prospective tertiary referral centre cohort study. The results of the search for the primary with rigid panendoscopy of the upper aerodigestive tract were compared to the evaluation with FDG PET. Panendoscopy revealed a primary tumour in 8/18 (44%) patients. PET accurately diagnosed five of these eight primary tumours, and gave one false positive and three false negative scans, resulting in a sensitivity of 63%, a specificity of 90%, an accuracy of 78%, a positive predictive value of 83% and a negative predictive value of 75%. Small primaries or primaries in areas with physiologically increased FDG uptake can be missed with PET owing to the limited resolution of the camera (approximately 5 mm). Our study in a small number of patients suggests that PET does not provide benefit in terms of detecting additional primary tumours if applied in addition to extensive clinical work-up. Considering its high specificity, PET could be of value as an initial evaluation instrument, reserving the need for extensive work-up to patients with negative scans. (orig.)

  10. Diagnosis of tumor and inflammation in the chest by positron emission tomography

    Positron emission tomography (PET) utilizing =fluorine-18=-fluorodeoxyglucose (FDG) has been shown to be highly accurate in differentiating benign from malignant pulmonary tumors. Our hospital started the PET clinics very recently. The FDG-PET for lung tumor diagnosis has been included in the menu of services from the beginning of this clinics. Our objective in this paper is to determine how effectively the FDG-PET reveals the nature of the tumor in the chest in relation to CT, tansthoracic fine-needle biopsy, and thoracotomy. Sixteen patients with lung lesions who had undergone PET were selected retrospectively as eligible for pathological justification. All the 14 cases of lung cancer showed highly positive uptake of FDG relative to the normal lung tissue. One case of benign tumor, one case of scarred aterectasis showed negative uptake. One case of active form of tuberculosis showed high uptake. Five lymph node stations in 3 cases were revealed to be the metastasized lymph nodes pathologically. FDG-PET visualized all of them. Absence of lymph node metastasis was confirmed in 7 cases. FDG-PET gave them negative results. (author)

  11. Use of Positron Emission Tomography/Computed Tomography in Radiation Treatment Planning for Lung Cancer

    Kezban Berberoğlu

    2016-06-01

    Full Text Available Radiotherapy (RT plays an important role in the treatment of lung cancer. Accurate diagnosis and staging are crucial in the delivery of RT with curative intent. Target miss can be prevented by accurate determination of tumor contours during RT planning. Currently, tumor contours are determined manually by computed tomography (CT during RT planning. This method leads to differences in delineation of tumor volume between users. Given the change in RT tools and methods due to rapidly developing technology, it is now more significant to accurately delineate the tumor tissue. F18 fluorodeoxyglucose positron emission tomography/CT (F18 FDG PET/CT has been established as an accurate method in correctly staging and detecting tumor dissemination in lung cancer. Since it provides both anatomic and biologic information, F18 FDG PET decreases interuser variability in tumor delineation. For instance, tumor volumes may be decreased as atelectasis and malignant tissue can be more accurately differentiated, as well as better evaluation of benign and malignant lymph nodes given the difference in FDG uptake. Using F18 FDG PET/CT, the radiation dose can be escalated without serious adverse effects in lung cancer. In this study, we evaluated the contribution of F18 FDG PET/CT for RT planning in lung cancer.

  12. Positron emission tomography, physical bases and comparaison with other techniques

    Positron emission tomography (PET) is a medical imaging technique that measures the three-dimensional distribution of molecules marked by a positron-emitting particle. PET has grown significantly in clinical fields, particularly in oncology for diagnosis and therapeutic follow purposes. The technical evolutions of this technique are fast. Among the technical improvements, is the coupling of the PET scan with computed tomography (CT). PET is obtained by intravenous injection of a radioactive tracer. The marker is usually fluorine (18F) embedded in a glucose molecule forming the 18-fluorodeoxyglucose (FDG-18). This tracer, similar to glucose, binds to tissues that consume large quantities of the sugar such cancerous tissue, cardiac muscle or brain. Detection using scintillation crystals (BGO, LSO, LYSO) suitable for high energy (511keV) recognizes the lines of the gamma photons originating from the annihilation of a positron with an electron. The electronics of detection or coincidence circuit is based on two criteria: a time window, of about 6 to 15 ns, and an energy window. This system measures the true coincidences that correspond to the detection of two photons of 511 kV from the same annihilation. Most PET devices are constituted by a series of elementary detectors distributed annularly around the patient. Each detector comprises a scintillation crystal matrix coupled to a finite number (4 or 6) of photomultipliers. The electronic circuit, or the coincidence circuit, determines the projection point of annihilation by means of two elementary detectors. The processing of such information must be extremely fast, considering the count rates encountered in practice. The information measured by the coincidence circuit is then positioned in a matrix or sinogram, which contains a set of elements of a projection section of the object. Images are obtained by tomographic reconstruction by powerful computer stations equipped with a software tools allowing the analysis and

  13. Cyclotron, positrons and PET [positron emission tomography]. An overview

    PET (positron emission tomography) is a powerful new scientific tool which is capable of revealing biochemical transformations while they are occurring in the brain and other organs in the living human body. The application of PET to problems in biology and medicine is dominated by the short half-life of the isotopes used to prepare the radiotracers. The most commonly used positron emitting isotopes are carbon-11, fluorine-18, nitrogen-13, and oxygen-15 which have half-lives of 20.4, 110, 10 and 2 minutes, respectively. Their incorporation into radiotracers having diverse chemical structures and biochemical specificities has allowed the study of blood flow, sugar metabolism, oxygen metabolism, neurotransmission, enzyme activity and binding sites for therapeutic drugs and substances of abuse. PET research is most commonly carried out at a Cyclotron-PET Center (cyclotron, positron emission tomography, chemistry laboratory) where the short-lived isotopes can be produced and used efficiently. The number of Cyclotron-PET Centers has grown from 4 in 1976 to several dozen in 1988 and the number is expected to double in the next five years attesting to the vitality of the field and the current and anticipated contributions to research in biology and medicine

  14. Ionization and positron emission in giant quasiatoms

    Electron excitation processes in superheavy quasiatoms are treated within a relativistic framework. Theoretical results on K-hole production rates as well as delta-electron and positron spectra are compared with experimental data. It is demonstrated that the study of heavy ion collisions with nuclear time delay promises a signature for the spontaneous positron formation in overcritical systems. Corresponding experimental results are confronted with our theoretical hypothesis. Recent speculations on the origin of the observed peak structures in positron spectra are critically reviewed. Atomic excitations are also employed to obtain information on the course of a nuclear reaction. Using a semiclassical picture we calculate the emission of delta-electrons and positrons in deep-inelastic nuclear reactions. Furthermore some consequences of conversion processes in giant systems are investigated. (orig.)

  15. Positron emission tomography imaging of gene expression

    The merging of molecular biology and nuclear medicine is developed into molecular nuclear medicine. Positron emission tomography (PET) of gene expression in molecular nuclear medicine has become an attractive area. Positron emission tomography imaging gene expression includes the antisense PET imaging and the reporter gene PET imaging. It is likely that the antisense PET imaging will lag behind the reporter gene PET imaging because of the numerous issues that have not yet to be resolved with this approach. The reporter gene PET imaging has wide application into animal experimental research and human applications of this approach will likely be reported soon

  16. Advanced instrumentation for Positron Emission Tomography

    This paper summarizes the physical processes and medical science goals that underly modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost. 71 refs., 3 figs., 3 tabs

  17. Advanced Instrumentation for Positron Emission Tomography [PET

    Derenzo, S. E.; Budinger, T. F.

    1985-04-01

    This paper summarizes the physical processes and medical science goals that underlay modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost.

  18. The review of myocardial positron emission computed tomography and positron imaging by gamma camera

    To measure myocardial blood flow, Nitrogen-13 ammonia, Oxygen-15 water, Rubidium-82 and et al. are used. Each has merit and demerit. By measuring myocardial coronary flow reserve, the decrease of flow reserve during dipyridamole in patients with hypercholesterolemia or diabetes mellitus without significant coronary stenosis was observed. The possibility of early detection of atherosclerosis was showed. As to myocardial metabolism, glucose metabolism is measured by Fluorine-18 fluorodeoxyglucose (FDG), and it is considered as useful for the evaluation of myocardial viability. We are using FDG to evaluate insulin resistance during insulin clamp in patients with diabetes mellitus by measuring glucose utilization rate of myocardium and skeletal muscle. FFA metabolism has been measured by 11C-palmitate, but absolute quantification has not been performed. Recently the method for absolute quantification was reported, and new radiopharmaceutical 18F-FTHA was reported. Oxygen metabolism has been estimated by 11C-acetate. Myocardial viability, cardiac efficiency was evaluated by oxygen metabolism. As to receptor or sympathetic nerve end, cardiac insufficiency or cardiac transplantation was evaluated. Imaging of positron emitting radiopharmaceutical by gamma camera has been performed. Collimator method is clinically useful for cardiac imaging of viability study. (author). 54 refs

  19. The review of myocardial positron emission computed tomography and positron imaging by gamma camera

    Ohtake, Tohru [Tokyo Univ. (Japan). Faculty of Medicine

    1998-04-01

    To measure myocardial blood flow, Nitrogen-13 ammonia, Oxygen-15 water, Rubidium-82 and et al. are used. Each has merit and demerit. By measuring myocardial coronary flow reserve, the decrease of flow reserve during dipyridamole in patients with hypercholesterolemia or diabetes mellitus without significant coronary stenosis was observed. The possibility of early detection of atherosclerosis was showed. As to myocardial metabolism, glucose metabolism is measured by Fluorine-18 fluorodeoxyglucose (FDG), and it is considered as useful for the evaluation of myocardial viability. We are using FDG to evaluate insulin resistance during insulin clamp in patients with diabetes mellitus by measuring glucose utilization rate of myocardium and skeletal muscle. FFA metabolism has been measured by {sup 11}C-palmitate, but absolute quantification has not been performed. Recently the method for absolute quantification was reported, and new radiopharmaceutical {sup 18}F-FTHA was reported. Oxygen metabolism has been estimated by {sup 11}C-acetate. Myocardial viability, cardiac efficiency was evaluated by oxygen metabolism. As to receptor or sympathetic nerve end, cardiac insufficiency or cardiac transplantation was evaluated. Imaging of positron emitting radiopharmaceutical by gamma camera has been performed. Collimator method is clinically useful for cardiac imaging of viability study. (author). 54 refs.

  20. Positron emission tomography of the lung

    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)

  1. When to perform positron emission tomography/computed tomography or radionuclide bone scan in patients with recently diagnosed prostate cancer

    Caldarella C

    2013-06-01

    Full Text Available Carmelo Caldarella,1 Giorgio Treglia,2 Alessandro Giordano,1 Luca Giovanella2 1Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Rome, Italy; 2Department of Nuclear Medicine and PET/CT Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland Abstract: Skeletal metastases are very common in prostate cancer and represent the main metastatic site in about 80% of prostate cancer patients, with a significant impact in patients' prognosis. Early detection of bone metastases is critical in the management of patients with recently diagnosed high-risk prostate cancer: radical treatment is recommended in case of localized disease; systemic therapy should be preferred in patients with distant secondary disease. Bone scintigraphy using radiolabeled bisphosphonates is of great importance in the management of these patients; however, its main drawback is its low overall accuracy, due to the nonspecific uptake in sites of increased bone turnover. Positron-emitting radiopharmaceuticals, such as fluorine-18-fluorodeoxyglucose, choline-derived drugs (fluorine-18-fluorocholine and carbon-11-choline and sodium fluorine-18-fluoride, are increasingly used in clinical practice to detect metastatic spread, and particularly bone involvement, in patients with prostate cancer, to reinforce or substitute information provided by bone scan. Each radiopharmaceutical has a specific mechanism of uptake; therefore, diagnostic performances may differ from one radiopharmaceutical to another on the same lesions, as demonstrated in the literature, with variable sensitivity, specificity, and overall accuracy values in the same patients. Whether bone scintigraphy can be substituted by these new methods is a matter of debate. However, greater radiobiological burden, higher costs, and the necessity of an in-site cyclotron limit the use of these positron emission tomography methods as first-line investigations in patients with prostate cancer

  2. Incidental colorectal polyps in positron emission tomography

    Fluorodeoxy glucose positron emission tomography/computed tomography (FDG PET/CT) is increasingly being used for diagnosing various malignancies and surveillance of cancer recurrence, staging and screening in high-risk individuals. Due to its high sensitivity in picking up small dysplastic lesions, incidental lesions are detected frequently. We present two patients who underwent PET CT as part of cancer screening and were incidentally detected with adenomatous colonic polyps. Colonoscopy and biopsy confirmed the diagnosis

  3. Positron emission tomography (PET) for cholangiocarcinoma

    Breitenstein, S; Apestegui, C.; Clavien, P.-A.

    2008-01-01

    The combination of positron emission tomography (PET) with computed tomography (PET-CT) provides simultaneous metabolic and anatomic information on tumors in the same imaging session. Sensitivity of PET/PET-CT is higher for intrahepatic (>90%) than for extrahepatic cholangiocarcinoma (CCA) (about 60%). The detection rate of distant metastasis is 100%. PET, and particularly PET-CT, improves the results and impacts on the oncological management in CCA compared with other imaging modalities. The...

  4. Positron Emission Tomography (PET) Evaluation After Initial Chemotherapy and Radiation Therapy Predicts Local Control in Rhabdomyosarcoma

    Purpose: 18-fluorodeoxyglucose positron emission tomography (PET) is already an integral part of staging in rhabdomyosarcoma. We investigated whether primary-site treatment response characterized by serial PET imaging at specific time points can be correlated with local control. Patients and Methods: We retrospectively examined 94 patients with rhabdomyosarcoma who received initial chemotherapy 15 weeks (median) before radiotherapy and underwent baseline, preradiation, and postradiation PET. Baseline PET standardized uptake values (SUVmax) and the presence or absence of abnormal uptake (termed PET-positive or PET-negative) both before and after radiation were examined for the primary site. Local relapse-free survival (LRFS) was calculated according to baseline SUVmax, PET-positive status, and PET-negative status by the Kaplan-Meier method, and comparisons were tested with the log-rank test. Results: The median patient age was 11 years. With 3-year median follow-up, LRFS was improved among postradiation PET-negative vs PET-positive patients: 94% vs 75%, P=.02. By contrast, on baseline PET, LRFS was not significantly different for primary-site SUVmax ≤7 vs >7 (median), although the findings suggested a trend toward improved LRFS: 96% for SUVmax ≤7 vs 79% for SUVmax >7, P=.08. Preradiation PET also suggested a statistically insignificant trend toward improved LRFS for PET-negative (97%) vs PET-positive (81%) patients (P=.06). Conclusion: Negative postradiation PET predicted improved LRFS. Notably, 77% of patients with persistent postradiation uptake did not experience local failure, suggesting that these patients could be closely followed up rather than immediately referred for intervention. Negative baseline and preradiation PET findings suggested statistically insignificant trends toward improved LRFS. Additional study may further understanding of relationships between PET findings at these time points and outcome in rhabdomyosarcoma.

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

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

    2016-01-01

    Purpose: The role of 18fluorodeoxyglucose 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. Materials and Methods: 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 2nd 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. Results: 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. Conclusion: 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. PMID:26917889

  6. Relationship of computed tomography perfusion and positron emission tomography to tumour progression in malignant glioma

    Yeung, Timothy P C [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Robarts Research Institute, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Yartsev, Slav [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Lee, Ting-Yim [Robarts Research Institute, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Imaging, The University of Western Ontario, London Health Sciences Centre, Victoria Hospital, Ontario, Canada, N6A 5W9 (Australia); Lawson Health Research Institute, St. Joseph' s Health Care London, Ontario, Canada, N6A 4V2 (Canada); Wong, Eugene [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Physics and Astronomy, The University of Western Ontario, Ontario, Canada, N6A 3K7 (Canada); He, Wenqing [Department of Statistical and Actuarial Sciences, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Fisher, Barbara; VanderSpek, Lauren L [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Macdonald, David [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Clinical Neurological Sciences, The University of Western Ontario, London Health Sciences Centre, University Hospital, Ontario, Canada, N6A 5A5 (Canada); Bauman, Glenn, E-mail: glenn.bauman@lhsc.on.ca [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada)

    2014-02-15

    Introduction: This study aimed to explore the potential for computed tomography (CT) perfusion and 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) in predicting sites of future progressive tumour on a voxel-by-voxel basis after radiotherapy and chemotherapy. Methods: Ten patients underwent pre-radiotherapy magnetic resonance (MR), FDG-PET and CT perfusion near the end of radiotherapy and repeated post-radiotherapy follow-up MR scans. The relationships between these images and tumour progression were assessed using logistic regression. Cross-validation with receiver operating characteristic (ROC) analysis was used to assess the value of these images in predicting sites of tumour progression. Results: Pre-radiotherapy MR-defined gross tumour; near-end-of-radiotherapy CT-defined enhancing lesion; CT perfusion blood flow (BF), blood volume (BV) and permeability-surface area (PS) product; FDG-PET standard uptake value (SUV); and SUV:BF showed significant associations with tumour progression on follow-up MR imaging (P < 0.0001). The mean sensitivity (±standard deviation), specificity and area under the ROC curve (AUC) of PS were 0.64 ± 0.15, 0.74 ± 0.07 and 0.72 ± 0.12 respectively. This mean AUC was higher than that of the pre-radiotherapy MR-defined gross tumour and near-end-of-radiotherapy CT-defined enhancing lesion (both AUCs = 0.6 ± 0.1, P ≤ 0.03). The multivariate model using BF, BV, PS and SUV had a mean AUC of 0.8 ± 0.1, but this was not significantly higher than the PS only model. Conclusion: PS is the single best predictor of tumour progression when compared to other parameters, but voxel-based prediction based on logistic regression had modest sensitivity and specificity.

  7. Positron Emission Tomography (PET) Evaluation After Initial Chemotherapy and Radiation Therapy Predicts Local Control in Rhabdomyosarcoma

    Dharmarajan, Kavita V., E-mail: dharmark@mskcc.org [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States); Wexler, Leonard H.; Gavane, Somali; Fox, Josef J.; Schoder, Heiko; Tom, Ashlyn K.; Price, Alison N.; Meyers, Paul A.; Wolden, Suzanne L. [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States)

    2012-11-15

    Purpose: 18-fluorodeoxyglucose positron emission tomography (PET) is already an integral part of staging in rhabdomyosarcoma. We investigated whether primary-site treatment response characterized by serial PET imaging at specific time points can be correlated with local control. Patients and Methods: We retrospectively examined 94 patients with rhabdomyosarcoma who received initial chemotherapy 15 weeks (median) before radiotherapy and underwent baseline, preradiation, and postradiation PET. Baseline PET standardized uptake values (SUVmax) and the presence or absence of abnormal uptake (termed PET-positive or PET-negative) both before and after radiation were examined for the primary site. Local relapse-free survival (LRFS) was calculated according to baseline SUVmax, PET-positive status, and PET-negative status by the Kaplan-Meier method, and comparisons were tested with the log-rank test. Results: The median patient age was 11 years. With 3-year median follow-up, LRFS was improved among postradiation PET-negative vs PET-positive patients: 94% vs 75%, P=.02. By contrast, on baseline PET, LRFS was not significantly different for primary-site SUVmax {<=}7 vs >7 (median), although the findings suggested a trend toward improved LRFS: 96% for SUVmax {<=}7 vs 79% for SUVmax >7, P=.08. Preradiation PET also suggested a statistically insignificant trend toward improved LRFS for PET-negative (97%) vs PET-positive (81%) patients (P=.06). Conclusion: Negative postradiation PET predicted improved LRFS. Notably, 77% of patients with persistent postradiation uptake did not experience local failure, suggesting that these patients could be closely followed up rather than immediately referred for intervention. Negative baseline and preradiation PET findings suggested statistically insignificant trends toward improved LRFS. Additional study may further understanding of relationships between PET findings at these time points and outcome in rhabdomyosarcoma.

  8. Fluorodeoxyglucose positron emission tomography in the initial staging of germ cell tumours

    Hain, S.F.; O' Doherty, M.J. [Clinical PET Centre, Guy' s and St Thomas' Hospitals, London (United Kingdom); Timothy, A.R.; Leslie, M.D.; Partridge, S.E. [Dept. of Clinical Oncology, Guy' s and St Thomas' Hospitals, London (United Kingdom); Huddart, R.A. [Dept. of Radiotherapy and Oncology, Royal Marsden, Surrey (United Kingdom)

    2000-05-01

    Testicular cancer is a rare tumour with the potential for cure at diagnosis. It is important, however, to identify those patients with metastases at presentation so as to ensure that the optimum treatment strategy is employed. Many criteria have been used to try to place patients into high- or low-risk groups, with variable success. Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has the potential to identify active disease and thereby influence further management. Here we report on a retrospective study of the use of FDG-PET in the detection of metastatic testicular carcinoma at diagnosis. Thirty-one patients [13 with seminoma and 18 with non-seminomatous germ cell tumours (13 teratomas, 5 mixed)] were staged by FDG-PET scanning. The imaging was performed using a Siemens ECAT 951 scanner. All results were assessed on the basis of histology or clinical follow-up. FDG-PET scan identified metastatic disease in ten and was negative in 16; there were no false-positives and five false-negatives. There were six patients in whom FDG-PET was negative and computed tomography was regarded as suspicious but follow-up was inconclusive. The positive predictive value was 100%. The negative predictive value was 76% or 91%, depending on whether the aforementioned six cases were regarded as true-negatives or false-negatives. It may be concluded that FDG-PET is capable of detecting metastatic disease at diagnosis that is not identified by other imaging techniques. These preliminary results are sufficient to suggest that a large prospective study should be performed to evaluate the role of FDG-PET in primary staging of disease. (orig.)

  9. {sup 18}F-FDG positron emission tomography in the early diagnosis of enterocolitis: preliminary results

    Kresnik, E.; Gallowitsch, H.J.; Igerc, I.; Kumnig, G.; Gomez, I.; Lind, P. [Nuclear Medicine and Special Endocrinology, PET Centre, General Hospital, St. Veiterstrasse 47, 9020 Klagenfurt (Austria); Mikosch, P.; Alberer, D.; Hebenstreit, A. [Department of Internal Medicine and Gastroenterology, General Hospital, Klagenfurt (Austria); Wuertz, F. [Department of Pathology, General Hospital, Klagenfurt (Austria); Kogler, D.; Gasser, J. [Department of Radiology, General Hospital, Klagenfurt (Austria)

    2002-10-01

    Collagenous and eosinophilic colitis are rare diseases characterised by chronic watery diarrhoea. Radiographic evaluation of the gastrointestinal tract and colonoscopy are usually non-diagnostic since as many as one-third of patients will have minor abnormalities. To date a few investigators have reported increased fluorine-18 fluorodeoxyglucose ({sup 18}F-FDG) uptake on positron emission tomography (PET) in patients with acute enterocolitis, but there have been no reports on the use of {sup 18}F-FDG PET for the diagnosis of collagenous or eosinophilic colitis in an early clinical stage. The aim of this preliminary study was to evaluate the usefulness of {sup 18}F-FDG PET in the early diagnosis of patients with colitis. We investigated five women (mean age 61.2{+-}12.1 years) who had been diagnosed as having colitis in an early clinical stage. In all but one of the patients, the diagnosis of colitis was based on biopsy. Magnetic resonance colonography, ultrasonography and colonoscopy were performed in all but one of the patients. Two women were identified as having collagenous colitis in an early clinical stage. Another two patients had eosinophilic colitis. The morphological imaging methods, magnetic resonance colonography and ultrasonography, yielded no suspicious findings, and the results of colonoscopy similarly showed no abnormalities. One patient had colitis due to bacterial infection. In all patients {sup 18}F-FDG PET showed a pathological increase in tracer uptake in the large bowel, suggestive of colitis. In four of the five patients, colitis was confirmed by histology, and in one, by bacterial analysis. {sup 18}F-FDG PET was able to detect colitis in an early clinical stage, when morphological imaging methods and colonoscopy were non-diagnostic. The early performance of {sup 18}F-FDG PET imaging in patients with possible colitis is encouraging. (orig.)

  10. Relationship of computed tomography perfusion and positron emission tomography to tumour progression in malignant glioma

    Introduction: This study aimed to explore the potential for computed tomography (CT) perfusion and 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) in predicting sites of future progressive tumour on a voxel-by-voxel basis after radiotherapy and chemotherapy. Methods: Ten patients underwent pre-radiotherapy magnetic resonance (MR), FDG-PET and CT perfusion near the end of radiotherapy and repeated post-radiotherapy follow-up MR scans. The relationships between these images and tumour progression were assessed using logistic regression. Cross-validation with receiver operating characteristic (ROC) analysis was used to assess the value of these images in predicting sites of tumour progression. Results: Pre-radiotherapy MR-defined gross tumour; near-end-of-radiotherapy CT-defined enhancing lesion; CT perfusion blood flow (BF), blood volume (BV) and permeability-surface area (PS) product; FDG-PET standard uptake value (SUV); and SUV:BF showed significant associations with tumour progression on follow-up MR imaging (P < 0.0001). The mean sensitivity (±standard deviation), specificity and area under the ROC curve (AUC) of PS were 0.64 ± 0.15, 0.74 ± 0.07 and 0.72 ± 0.12 respectively. This mean AUC was higher than that of the pre-radiotherapy MR-defined gross tumour and near-end-of-radiotherapy CT-defined enhancing lesion (both AUCs = 0.6 ± 0.1, P ≤ 0.03). The multivariate model using BF, BV, PS and SUV had a mean AUC of 0.8 ± 0.1, but this was not significantly higher than the PS only model. Conclusion: PS is the single best predictor of tumour progression when compared to other parameters, but voxel-based prediction based on logistic regression had modest sensitivity and specificity

  11. 18-F fluorodeoxyglucose uptake in positron emission tomography as a pathological grade predictor for renal clear cell carcinomas

    Noda, Yoshifumi; Goshima, Satoshi; Kondo, Hiroshi; Watanabe, Haruo; Kawada, Hiroshi; Kawai, Nobuyuki; Tanahashi, Yukichi [Gifu University Hospital, Department of Radiology, Gifu (Japan); Kanematsu, Masayuki [Gifu University Hospital, Department of Radiology, Gifu (Japan); Gifu University Hospital, Department of Radiology Services, Gifu (Japan); Suzui, Natsuko [Gifu University Hospital, Department of Pathology, Gifu (Japan); Hirose, Yoshinobu [Osaka Medical College, Department of Pathology, Osaka (Japan); Matsunaga, Kengo [Kizawa Memorial Hospital, Department of Pathology, Minokamo (Japan); Nishibori, Hironori [Kizawa Memorial Hospital, Department of Radiology, Minokamo (Japan); Bae, Kyongtae T. [University of Pittsburgh Medical Center, Department of Radiology, Pittsburgh, PA (United States)

    2015-10-15

    To evaluate the usefulness of Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18-F FDG-PET/CT) in the prediction of Fuhrman pathological grades of renal clear cell carcinoma (cRCC). This retrospective study was approved by our institutional review board, and written informed consent was waived. Thirty-one patients with pathologically proven cRCC underwent 18-F FDG-PET/CT for tumour staging. Maximum standardized uptake value of cRCC (tumour SUV{sub max}) and mean SUV of the liver and spleen (liver and spleen SUV{sub mean}) were measured by two independent observers. Tumour SUV{sub max}, tumour-to-liver SUV ratio, and tumour-to-spleen SUV ratio were correlated with the pathological grades. Logistic analysis demonstrated that only the tumour-to-liver SUV ratio was a significant parameter for differentiating high-grade (Fuhrman grades 3 and 4) tumours from low-grade (Fuhrman grades 1 and 2) tumours (P = 0.007 and 0.010 for observers 1 and 2, respectively). Sensitivity, specificity, and positive and negative predictive values for detecting tumours of Fuhrman grades 3 and 4 were 64, 100, 100, and 77 %, respectively, for observer 1, and 79, 88, 85, and 83 %, respectively, for observer 2. The tumour-to-liver SUV ratio with 18-F FDG-PET/CT appeared to be a valuable imaging biomarker in the prediction of high-grade cRCC. (orig.)

  12. 18-F fluorodeoxyglucose uptake in positron emission tomography as a pathological grade predictor for renal clear cell carcinomas

    To evaluate the usefulness of Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18-F FDG-PET/CT) in the prediction of Fuhrman pathological grades of renal clear cell carcinoma (cRCC). This retrospective study was approved by our institutional review board, and written informed consent was waived. Thirty-one patients with pathologically proven cRCC underwent 18-F FDG-PET/CT for tumour staging. Maximum standardized uptake value of cRCC (tumour SUVmax) and mean SUV of the liver and spleen (liver and spleen SUVmean) were measured by two independent observers. Tumour SUVmax, tumour-to-liver SUV ratio, and tumour-to-spleen SUV ratio were correlated with the pathological grades. Logistic analysis demonstrated that only the tumour-to-liver SUV ratio was a significant parameter for differentiating high-grade (Fuhrman grades 3 and 4) tumours from low-grade (Fuhrman grades 1 and 2) tumours (P = 0.007 and 0.010 for observers 1 and 2, respectively). Sensitivity, specificity, and positive and negative predictive values for detecting tumours of Fuhrman grades 3 and 4 were 64, 100, 100, and 77 %, respectively, for observer 1, and 79, 88, 85, and 83 %, respectively, for observer 2. The tumour-to-liver SUV ratio with 18-F FDG-PET/CT appeared to be a valuable imaging biomarker in the prediction of high-grade cRCC. (orig.)

  13. Positron Emission Tomography: Its 65 years

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

    2016-04-01

    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, pre-clinical and hybrid scanners (, PET/CT and PET/MR) is reported. Finally the actual trend and the recent and future technological developments are fully illustrated.

  14. Positron emission tomography of FDG in schizophrenia

    The use of the Donner dynamic positron emission tomograph to study fluorodeoxyglucose labelled 18F uptake in the brain of six patients with schizophrenia is reported. The glucose metabolic rate and the local cerebral metabolic rate were calculated. The dynamic brain uptake data and the blood input function were used to calculate rate constants by an iterative least squares fitting program for all regions of interest chosen in the brain. Although the number of patients was small, differences in k3 were statistically significant in several brain regions compared with normal controls

  15. Perspectives for positron emission tomography with RPCs

    In this study, we address the feasibility and main properties of a positron emission tomograph (PET) based on RPCs. The concept, making use of the converter-plate principle, takes advantage of the intrinsic layered structure of RPCs and its simple and economic construction. The extremely good time and position resolutions of RPCs also allow the TOF-PET imaging technique to be considered. Monte-Carlo simulations, supported by experimental data, are presented and the main advantages and drawbacks for applications of potential interest are discussed

  16. Positron Emission Tomography Imaging of Pancreatic Cancer

    Saravanan Kokila Krishnamoorthy

    2014-03-01

    Full Text Available Positron emission tomography (PET using 18F-fluorodeoxyglucose (FDG is increasingly used for the staging of solidmalignancies, including lung and esophagus. However, controversy still exists in relation to the application of PET inpancreatic cancer. The authors review seven studies (Abstracts #183, #189, #190, #254, #357, #375, #378 presented at the2014 ASCO Gastrointestinal Cancers Symposium and discuss on the role of PET in this disease. As the limitations of theResponse Evaluation Criteria In Solid Tumors (RECIST continue to become evident, FDG-PET may identify changes in themetabolic activity within pancreatic adenocarcinoma, and can provide both diagnostic and prognostic information.

  17. Positron emission tomography tracers for imaging angiogenesis

    Position emission tomography imaging of angiogenesis may provide non-invasive insights into the corresponding molecular processes and may be applied for individualized treatment planning of antiangiogenic therapies. At the moment, most strategies are focusing on the development of radiolabelled proteins and antibody formats targeting VEGF and its receptor or the ED-B domain of a fibronectin isoform as well as radiolabelled matrix metalloproteinase inhibitors or αvβ3 integrin antagonists. Great efforts are being made to develop suitable tracers for different target structures. All of the major strategies focusing on the development of radiolabelled compounds for use with positron emission tomography are summarized in this review. However, because the most intensive work is concentrated on the development of radiolabelled RGD peptides for imaging αvβ3 expression, which has successfully made its way from bench to bedside, these developments are especially emphasized. (orig.)

  18. [Basic principles of 18F-fluorodeoxyglucose positron emission tomography].

    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. PMID:12506765

  19. 77 FR 8262 - Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    2012-02-14

    ... Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice... entitled ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs.'' The draft... Applications for Positron Emission Tomography (PET) drugs.'' The draft guidance summarizes the IND process...

  20. When to perform positron emission tomography/computed tomography or radionuclide bone scan in patients with recently diagnosed prostate cancer

    Skeletal metastases are very common in prostate cancer and represent the main metastatic site in about 80% of prostate cancer patients, with a significant impact in patients’ prognosis. Early detection of bone metastases is critical in the management of patients with recently diagnosed high-risk prostate cancer: radical treatment is recommended in case of localized disease; systemic therapy should be preferred in patients with distant secondary disease. Bone scintigraphy using radiolabeled bisphosphonates is of great importance in the management of these patients; however, its main drawback is its low overall accuracy, due to the nonspecific uptake in sites of increased bone turnover. Positron-emitting radiopharmaceuticals, such as fluorine-18-fluorodeoxyglucose, choline-derived drugs (fluorine-18-fluorocholine and carbon-11-choline) and sodium fluorine-18-fluoride, are increasingly used in clinical practice to detect metastatic spread, and particularly bone involvement, in patients with prostate cancer, to reinforce or substitute information provided by bone scan. Each radiopharmaceutical has a specific mechanism of uptake; therefore, diagnostic performances may differ from one radiopharmaceutical to another on the same lesions, as demonstrated in the literature, with variable sensitivity, specificity, and overall accuracy values in the same patients. Whether bone scintigraphy can be substituted by these new methods is a matter of debate. However, greater radiobiological burden, higher costs, and the necessity of an in-site cyclotron limit the use of these positron emission tomography methods as first-line investigations in patients with prostate cancer: bone scintigraphy remains the mainstay for the detection of bone metastases in current clinical practice

  1. When to perform positron emission tomography/computed tomography or radionuclide bone scan in patients with recently diagnosed prostate cancer.

    Caldarella, Carmelo; Treglia, Giorgio; Giordano, Alessandro; Giovanella, Luca

    2013-01-01

    Skeletal metastases are very common in prostate cancer and represent the main metastatic site in about 80% of prostate cancer patients, with a significant impact in patients' prognosis. Early detection of bone metastases is critical in the management of patients with recently diagnosed high-risk prostate cancer: radical treatment is recommended in case of localized disease; systemic therapy should be preferred in patients with distant secondary disease. Bone scintigraphy using radiolabeled bisphosphonates is of great importance in the management of these patients; however, its main drawback is its low overall accuracy, due to the nonspecific uptake in sites of increased bone turnover. Positron-emitting radiopharmaceuticals, such as fluorine-18-fluorodeoxyglucose, choline-derived drugs (fluorine-18-fluorocholine and carbon-11-choline) and sodium fluorine-18-fluoride, are increasingly used in clinical practice to detect metastatic spread, and particularly bone involvement, in patients with prostate cancer, to reinforce or substitute information provided by bone scan. Each radiopharmaceutical has a specific mechanism of uptake; therefore, diagnostic performances may differ from one radiopharmaceutical to another on the same lesions, as demonstrated in the literature, with variable sensitivity, specificity, and overall accuracy values in the same patients. Whether bone scintigraphy can be substituted by these new methods is a matter of debate. However, greater radiobiological burden, higher costs, and the necessity of an in-site cyclotron limit the use of these positron emission tomography methods as first-line investigations in patients with prostate cancer: bone scintigraphy remains the mainstay for the detection of bone metastases in current clinical practice. PMID:23861598

  2. Pulmonary studies using positron emission tomography

    The detailed investigation of regional differences in lung function at a local level began when suitable γ-ray emitting isotopes and focused external radiation detectors (especially the Anger γ-camera) became available. A major recent advance has been the development of positron emission tomography (PET), which provides a powerful combination of highly accurate tomographic reconstruction of radioisotope concentration with a potentially unlimited list of biological compounds to be labelled with the positron emitting isotopes of oxygen, carbon and fluorine. Early studies using PET focused on the inhalation of 11CO (or C15O) and 19Ne gases and the intravenous injection of 13N in saline and H215O for the measurement of relatively simple aspects of regional lung function, such as tissue, blood and gas volumes, blood flow, ventilation and ventilation/perfusion (V'A/Q'). More recent work has been directed towards the more challenging areas of regional endothelial permeability, carbohydrate utilization, enzyme and receptor binding assays, and in vivo pharmacokinetics. The short physical half-lives of the isotopes (17 s to 2 h) and the noninvasive nature of PET allows serial measurements to be made on patients (within the constraints of permitted radiation doses) to assess the effect of physiological and therapeutic interventions. (au) 80 refs

  3. Positron emission tomography: radioisotope and radiopharmaceutical production

    A Centre for Positron Emission Tomography (PET) has been operational within the Department of Nuclear Medicine at the Austin and Repatriation Medical Centre (A and RMC) in Melbourne for seven years. PET is a non-invasive imaging technique based on the use of biologically relevant compounds labelled with short-lived positron-emitting radionuclides such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18. The basic facility consists of a medical cyclotron (10 MeV proton and 5 MeV deuteron), six lead-shielded hot cells with associated radiochemistry facilities, radiopharmacy and a whole body PET scanner. A strong radiolabelling development program, including the production of 15O-oxygen, 15O-carbon monoxide, 15O-carbon dioxide, 15O-water, 13N-ammonia, 18F-FDG, 18F-FMISO, 11C-SCH23390 and 11C-flumazenil has been pursued to support an ambitious clinical and research program in neurology, oncology, cardiology and psychiatry. Copyright (1999) Australasian Physical and Engineering Sciences in Medicine and the College of Biomedical Engineers

  4. Positron emission tomography of the heart

    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

  5. Positron emission tomography in urological cancer

    In staging cancer of the urinary bladder, the kidneys and the prostate and of testicular cancer there is a need for detecting tumor involvement of the lymph nodes to avoid surgical exploration. Positron emission tomography (PET) using fluorodeoxyglucose (FDG) can detect tumorous lymph nodes (sensitivity: 70%, specificity: 85%) which is helpful for several patients. In carcinoma of the prostate, other radiotracers than FDG (e.g. C-11-choline) might be more sensitive to detect tumorous lymph nodes. Up to now no diagnostical benefit of PET in germ cell tumors could be demonstrated in the published small series. In principle FDG-PET is useful in diagnosis of recurrence. In germ cell cancer FDG-PET seems to identify effectively persistent vital tumor tissue after chemotherapy. A multicenter study was initiated to demonstrate the potential of FDG-PET in a sufficient number of patients with germ cell tumor. (orig.)

  6. Compact conscious animal positron emission tomography scanner

    Schyler, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois; Volkow, Nora

    2006-10-24

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

  7. Positron emission tomography and basal ganglia functions

    With the advent of positron emission tomography (PET), studies on the human brain function and pathophysiology of brain damage have been extremely progressed. It is well-known that the basal ganglia plays an important role as one of the central nervous system involved in exercise regulation. More recently, the potential involvement of the basal ganglia in psychological processes, such as cognitive function, has been pointed out, receiving much attention. In spite of such a lot of studies, however, basal ganglia function remains unclear. This paper describes the relationships between PET findings and basal ganglia function. PET findings are discussed in relation to brain energy metabolism and striatal dopamine function. Pathophysiology of the basal ganglia are described in terms of the following diseases: Parkinson's disease, Parkinson's syndrome, progressive supranuclear palsy, Huntington's disease, and dystonia. Physiological backgrounds of the basal ganglia for PET images are also referred to. (N.K.) 75 refs

  8. Positron emission tomography of the heart

    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.

  9. Motion correction in thoracic positron emission tomography

    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...

  10. Recent developments in positron emission tomography (PET) instrumentation

    This paper presents recent detector developments and perspectives for positron emission tomography (PET) instrumentation used for medical research, as well as the physical processes in positron annihilation, photon scattering and detection, tomograph design considerations, and the potentials for new advances in detectors. 117 refs., 4 figs., 4 tabs

  11. Simultaneous emission and transmission scanning in positron emission tomography

    Examination by PET (positron emission tomography) scanning, following the dosage of 2-deoxy-18F fluoro-D-glucose (FDG), is positively utilized for the diagnosis of cancers, rather than for the purpose of studies. This is because the examination by FDG-PET (PET scanning following the dosage of FDG) ensures higher efficiency in discrimination of cancers, than conventional CT and PET. The method of whole body scanning by PET scanning following the dosage of FDG is effectively utilized not only for discrimination cancers, but also for determining the degree of malignancy of tumors and evaluating the methods of treatment of cancers. In conventional methods for examining the degree of malignancy of tumors and evaluating the methods of cancer treatment, it is necessary to correct for the gamma-ray attenuation, which requires a longer time for examination, increasing the physical and psychological pains of the patients. We have installed the simultaneous emission and transmission scanning capability into the HEADTOME-V of the Shimadzu SET-2000W Series positron emission tomographic scanning instruments, to establish an instrument that permits FDG-PET whole body scanning in actual clinical fields, with minimized physical and psychological pains of patients concerned, yet ensuring an outstandingly high examination efficiency. This report also presents some data obtained by this newly developed instrument and those obtained in practical applications. (author)

  12. Simplifications in analyzing positron emission tomography data: effects on outcome measures

    Initial validation studies of new radiotracers generally involve kinetic models that require a measured arterial input function. This allows for the separation of tissue binding from delivery and blood flow effects. However, when using a tracer in a clinical setting, it is necessary to eliminate arterial blood sampling due to its invasiveness and the extra burden of counting and analyzing the blood samples for metabolites. In some cases, it may also be necessary to replace dynamic scanning with a shortened scanning period some time after tracer injection, as is done with FDG (F-18 fluorodeoxyglucose). These approximations represent loss of information. In this work, we considered several questions related to this: (1) Do differences in experimental conditions (drug treatments) or populations affect the input function, and what effect, if any, does this have on the final outcome measure? (2) How do errors in metabolite measurements enter into results? (3) What errors are incurred if the uptake ratio is used in place of the distribution volume ratio? (4) Is one- or two-point blood sampling any better for FDG data than the standardized uptake value? and (5) If blood sampling is necessary, what alternatives are there to arterial blood sampling? The first three questions were considered in terms of data from human dynamic positron emission tomography (PET) studies under conditions of baseline and drug pretreatment. Data from [11C]raclopride studies and those from the norepinephrine transporter tracer (S,S)-[11C]O-methyl reboxetine were used. Calculation of a metabolic rate for FDG using the operational equation requires a measured input function. We tested a procedure based on two blood samples to estimate the plasma integral and convolution that occur in the operational equation. There are some tracers for which blood sampling is necessary. Strategies for brain studies involve using the internal carotids in estimating the radioactivity after correcting for partial

  13. Simulation of the annihilation emission of galactic positrons

    Positrons annihilate in the central region of our Galaxy. This has been known since the detection of a strong emission line centered on an energy of 511 keV in the direction of the Galactic center. This gamma-ray line is emitted during the annihilation of positrons with electrons from the interstellar medium. The spectrometer SPI, onboard the INTEGRAL observatory, performed spatial and spectral analyses of the positron annihilation emission. This thesis presents a study of the Galactic positron annihilation emission based on models of the different interactions undergone by positrons in the interstellar medium. The models are relied on our present knowledge of the properties of the interstellar medium in the Galactic bulge, where most of the positrons annihilate, and of the physics of positrons (production, propagation and annihilation processes). In order to obtain constraints on the positrons sources and physical characteristics of the annihilation medium, we compared the results of the models to measurements provided by the SPI spectrometer. (author)

  14. Resistive plate chambers in positron emission tomography

    Crespo, Paulo; Blanco, Alberto; Couceiro, Miguel; Ferreira, Nuno C.; Lopes, Luís; Martins, Paulo; Ferreira Marques, Rui; Fonte, Paulo

    2013-07-01

    Resistive plate chambers (RPC) were originally deployed for high energy physics. Realizing how their properties match the needs of nuclear medicine, a LIP team proposed applying RPCs to both preclinical and clinical positron emission tomography (RPC-PET). We show a large-area RPC-PET simulated scanner covering an axial length of 2.4m —slightly superior to the height of the human body— allowing for whole-body, single-bed RPC-PET acquisitions. Simulations following NEMA (National Electrical Manufacturers Association, USA) protocols yield a system sensitivity at least one order of magnitude larger than present-day, commercial PET systems. Reconstruction of whole-body simulated data is feasible by using a dedicated, direct time-of-flight-based algorithm implemented onto an ordered subsets estimation maximization parallelized strategy. Whole-body RPC-PET patient images following the injection of only 2mCi of 18-fluorodesoxyglucose (FDG) are expected to be ready 7 minutes after the 6 minutes necessary for data acquisition. This compares to the 10-20mCi FDG presently injected for a PET scan, and to the uncomfortable 20-30minutes necessary for its data acquisition. In the preclinical field, two fully instrumented detector heads have been assembled aiming at a four-head-based, small-animal RPC-PET system. Images of a disk-shaped and a needle-like 22Na source show unprecedented sub-millimeter spatial resolution.

  15. Utility of positron emission tomography in schwannomatosis.

    Lieber, Bryan; Han, ByoungJun; Allen, Jeffrey; Fatterpekar, Girish; Agarwal, Nitin; Kazemi, Noojan; Zagzag, David

    2016-08-01

    Schwannomatosis is characterized by multiple non-intradermal schwannomas with patients often presenting with a painful mass in their extremities. In this syndrome malignant transformation of schwannomas is rare in spite of their large size at presentation. Non-invasive measures of assessing the biological behavior of plexiform neurofibromas in neurofibromatosis type 1 such as positron emission tomography (PET), CT scanning and MRI are well characterized but little information has been published on the use of PET imaging in schwannomatosis. We report a unique clinical presentation portraying the use of PET imaging in schwannomatosis. A 27-year-old woman presented with multiple, rapidly growing, large and painful schwannomas confirmed to be related to a constitutional mutation in the SMARCB1 complex. Whole body PET/MRI revealed numerous PET-avid tumors suggestive of malignant peripheral nerve sheath tumors. Surgery was performed on multiple tumors and none of them had histologic evidence of malignant transformation. Overall, PET imaging may not be a reliable predictor of malignant transformation in schwannomatosis, tempering enthusiasm for surgical interventions for tumors not producing significant clinical signs or symptoms. PMID:26960263

  16. Physiologic signal detection in positron emission tomography

    Positron emission tomography enables the noninvasive quantification in vivo of three-dimensional radionuclide distributions throughout the human body. Estimation of neurotransmitter and receptor function is performed through the application of tracer kinetic models and non-linear multiple regression parameter estimation methods. These quantitative estimates are often limited by the interaction between imaging characteristics of the PET scanner and the three-dimensional radionuclide distribution within the organ of interest. In order to assess the potential of PET to detect subtle changes in the function of the central nervous system, a three-dimensional PET simulation procedure based upon a digital brain phantom and tomograph detector response functions has been performed. Radiopharmaceutical kinetics for individual structures of the brain phantom (cortex, white matter, basal ganglia, etc.) have been assigned based upon in vitro autoradiography of human postmortem tissue and animal biodistribution studies. The recovery of the PET signals which originate from anatomic structures of interest has been evaluated for studies of the benzodiazepine, muscarinic, opiate, and GABA systems of the human brain. Typical results and the limitations of signal detection in PET neurotransmitter and receptor studies are discussed

  17. Amorphous silicon detectors in positron emission tomography

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters ε2τ's are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs

  18. Beyond FDG positron emission tomography imaging

    At present, positron emission tomography/computed tomography (PET/CT) is one of the most rapidly growing areas of medical imaging, with many applications in the clinical management of patients with cancer. Although ((18)F) fluorodeoxyglucose (FDG)-PET/CT imaging provides high specificity and sensitivity in several kinds of cancer and has many applications, it is important to recognize that FDG is not a 'specific' radiotracer for imaging malignant disease. Highly 'tumor-specific' PET radiopharmaceuticals are essential to meet the growing demand of radioisotope-based molecular imaging technology. C-11 Methionine PET has been used to better define the radiotherapy field both for CNS tumors and head and neck (H and N) tumors to localize the most metabolic area inside a brain mass to guide the biopsy or in early evaluation of radiotherapy effect on H and N cancer. Flurodihydroxyphenylalanine (FDOPA) is an aromatic amino acid labelled with 18F. Besides it has also been introduced into oncological practice, in particular for malignant tumors of neural crest origin

  19. Amorphous silicon detectors in positron emission tomography

    Conti, M. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy) Lawrence Berkeley Lab., CA (USA)); Perez-Mendez, V. (Lawrence Berkeley Lab., CA (USA))

    1989-12-01

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

  20. Patient radiation protection in positron emission tomography

    Patient radiation protection in Positron Emission Tomography (PET) is closely related to the correct execution of studies: proper scanner performance, and optimization of both image quality and patient dose. We describe the quality control tests considered as essential: scanner stability, spatial resolution, sensitivity and tomographic uniformity. Knowledge of the dose received by the critical organ and the effective dose for each radiopharmaceutical allows the establishment of strategies for dose optimization. Although a great variety of PET tracers exist, we review the dose produced by F-FDG, the most widely used tracer, and those used in our PET Center O-Water, N-Ammonia, C-Methionine, C-Choline, F-Choline, F-Dopa, and F-FHBG. Reduction of administered activity to the patient is the direct way to reduce the dose. Thus, PET acquisition in the 3D mode, with higher sensitivity, is a determining factor. In order to reduce the dose to different organs, efforts should be directed to the critical organs, mainly the urinary bladder wall. Finally, correct patient preparation improves, PET image quality, due to an optimum tracer uptake, which optimizes the dose to different organs. (Author) 25 refs

  1. Radiation Therapy in Primary Mediastinal B-Cell Lymphoma With Positron Emission Tomography Positivity After Rituximab Chemotherapy

    Purpose: To investigate the role of radiation therapy (RT) in patients affected with primary mediastinal B-cell lymphoma (PMBCL) with residual 18fluorodeoxyglucose positron emission tomography (18FDG-PET)-positive disease after rituximab chemotherapy (R-CT). Methods and Materials: Thirty-seven patients treated with R-CT and RT, all with 18FDG-PET scan at diagnosis and before RT, were included. All 18FDG-PET scans were reviewed, and responses were classified according to the Deauville 5-point scoring system. Outcomes measures were overall survival (OS) and progression-free survival (PFS), estimated for the whole cohort and for subgroups according to 18FDG-PET score after R-CT. Results: The median follow-up time was 40.9 months. Three patients were assigned to Deauville score 1 (8.1%), 9 to score 2 (24.3%), 7 to score 3 (19%), 14 to score 4 (37.8%), and 4 to score 5 (10.8%). After RT, all patients with score 3-4 experienced a complete response (CR). Among patients with score 5, 1 was in CR (25%), 2 had persistent positivity (50%), and 1 showed progressive disease (25%). A total of 4 patients experienced progression or relapse: 1 of 33 (3%) with scores 1-4, and 3 of 4 (75%) with score 5. The 3-year OS and PFS of the whole cohort were 89.8% and 88.7%, respectively. OS was significantly different between scores 1-3 and scores 4-5 (100% vs 77% at 3 years, P18FDG-PET scan after R-CT. RT is able to convert to CR approximately 85% of these patients, but those with a Deauville score of 5 (10%) appear at high risk of progression and death, and they might be candidates for intensified programs

  2. Shielding design for positron emission tomography facility

    With the recent advent of readily available tracer isotopes, there has been marked increase in the number of hospital-based and free-standing positron emission tomography (PET) clinics. PET facilities employ relatively large activities of high-energy photon emitting isotopes, which can be dangerous to the health of humans and animals. This coupled with the current dose limits for radiation worker and members of the public can result in shielding requirements. This research contributes to the calculation of the appropriate shielding to keep the level of radiation within an acceptable recommended limit. Two different methods were used including measurements made at selected points of an operating PET facility and computer simulations by using Monte Carlo Transport Code. The measurements mainly concerned the radiation exposure at different points around facility using the survey meter detectors and Thermoluminescent Dosimeters (TLD). Then the set of manual calculation procedures were used to estimate the shielding requirements for a newly built PEF facility. The results from the measurement and the computer simulation were compared to the results obtained from the set manual calculation procedure. In general, the estimated weekly dose at the points of interest is lower than the regulatory limits for the little company of Mary Hospital. Furthermore, the density and the HVL for normal strength concrete and clay bricks are almost similar. In conclusion, PET facilities present somewhat different design requirements and are more likely to require additional radiation shielding. Therefore, existing shields at the little Company of Mary Hospital are in general found to be adequate and satisfactory and additional shielding was found necessary at the new PET facility in the department of Nuclear Medicine of the Dr. George Mukhari Hospital. By use of appropriate design, by implying specific shielding requirements and by maintaining good operating practices, radiation doses to

  3. Electroacupuncture at Tianshu(ST 25)for diarrhea-predominant irritable bowel syndrome using positron emission tomography Changes in visceral sensation center

    Huirong Liu; Enhua Zhou; Huangan Wu; Li Qi; Xiaolong Wang; Yihui Guan; Chuantao Zuo; Linying Tan; Lingsong Yuan; Xiaopeng Ma; Xiaomei Wang

    2010-01-01

    Previous studies have demonstrated that electroacupuncture therapy is effective in the treatment of irritable bowel syndrome.However,the precise mechanism of this therapy is unknown.The present study served to investigate the effects of electroacupuncture therapy on treatment of patients with diarrhea-predominant irritable bowel syndrome(IBS).We compared brain activation maps based on the changes of cerebral glucose metabolism obtained by 18-fluorodeoxyglucose positron emission tomography scanning under three conditions: resting,rectal balloon distension and rectal balloon distension plus electroacupuncture.Under the resting condition,compared with healthy controls,IBS patients displayed an increasing regional cerebral metabolic rate of glucose over a wide range:bilateral superior temporal gyrus,right middle occipital gyrus,superior frontal gyrus and bilateral middle frontal gyrus.However,there was no significant activity in the visceral pain center.Compared with the resting condition,under the rectal balloon distension condition,patients with IBS had a greater regional cerebral metabolic rate of glucose in the prefrontal cortex,left anterior cingulate cortex,postcentral gyrus,precentral gyrus and temporal gyrus.Under the rectal balloon distension plus electroacupuncture condition,stimulation by electroacupuncture at Tianshu(ST 25)manifested a decreased regional cerebral metabolic rate of glucose in the left cingulate gyrus,right insula,right caudate nucleus,fusiform gyrus and hippocampal gyrus.Electroacupuncture therapy relieved abdominal pain,distension or discomfort by decreasing glucose metabolism in the brain.

  4. IgG4-associated multifocal systemic fibrosis detected by cancer screening with 18F-FDG positron emission tomography/computed tomography

    Serial fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) studies were performed with an interval of one year in a 62-year-old man with IgG4-associated multifocal systemic fibrosis (IMSF). He first underwent 18F-FDG PET/CT cancer screening, which revealed multiple 18F-FDG-avid uptakes in the pancreas, prostate, and lymph nodes in the upper mediastinum, pulmonary hila, porta hepatis, and the left iliac and inguinal regions. He was not symptomatic at this initial examination. The follow-up 18F-FDG PET/CT study showed disappearance of 18F-FDG-avid uptake foci in the pancreas despite no treatment having been administered, but demonstrated new lesions in the abdominal para-aortic region and more intense FDG uptake in the porta hepatis lesion. Serial 18F-FDG PET/CT studies might be useful in monitoring patients with IMSF, as well as evaluating the state of systemic involvement. Findings of 18F-FDG PET/CT may provide information useful for determining the optimal initiation of IMSF treatment. (author)

  5. Positron emission tomography/computed tomography.

    Townsend, David W

    2008-05-01

    Accurate anatomical localization of functional abnormalities obtained with the use of positron emission tomography (PET) is known to be problematic. Although tracers such as (18)F-fluorodeoxyglucose ((18)F-FDG) visualize certain normal anatomical structures, the spatial resolution is generally inadequate for accurate anatomic localization of pathology. Combining PET with a high-resolution anatomical imaging modality such as computed tomography (CT) can resolve the localization issue as long as the images from the two modalities are accurately coregistered. However, software-based registration techniques have difficulty accounting for differences in patient positioning and involuntary movement of internal organs, often necessitating labor-intensive nonlinear mapping that may not converge to a satisfactory result. Acquiring both CT and PET images in the same scanner obviates the need for software registration and routinely provides accurately aligned images of anatomy and function in a single scan. A CT scanner positioned in line with a PET scanner and with a common patient couch and operating console has provided a practical solution to anatomical and functional image registration. Axial translation of the couch between the 2 modalities enables both CT and PET data to be acquired during a single imaging session. In addition, the CT images can be used to generate essentially noiseless attenuation correction factors for the PET emission data. By minimizing patient movement between the CT and PET scans and accounting for the axial separation of the two modalities, accurately registered anatomical and functional images can be obtained. Since the introduction of the first PET/CT prototype more than 6 years ago, numerous patients with cancer have been scanned on commercial PET/CT devices worldwide. The commercial designs feature multidetector spiral CT and high-performance PET components. Experience has demonstrated an increased level of accuracy and confidence in the

  6. The introduction of positron emission tomography in Australia

    Positron Emission Tomography (PET) is a relatively new medical imaging modality based on images of the distribution of positron emitting radioisotopes in the human body. A PET scan can non-invasively provide quantitative information on the in vivo function performance of an organ, part thereof, or a bodily process. Two PET centres currently being established in Melbourne and in Sydney are introduced. 18 refs., 1 tab., 5 figs

  7. Human cerebral circulation. Positron emission tomography studies

    We reviewed the literature on human cerebral circulation and oxygen metabolism, as measured by positron emission tomography (PET), with respect to normal values and of regulation of cerebral circulation. A multicenter study in Japan showed that between-center variations in cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) values were not considerably larger than the corresponding within-center variations. Overall mean±SD values in cerebral cortical regions of normal human subjects were as follows: CBF=44.4±6.5 ml/100 ml/min; CBV=3.8±0.7 ml/100 ml; OEF=0.44±0.06; CMRO2=3.3±0.5 ml/100 ml/min (11 PET centers, 70 subjects). Intrinsic regulation of cerebral circulation involves several factors. Autoregulation maintains CBF in response to changes in cerebral perfusion pressure; chemical factors such as PaCO2 affect cerebral vascular tone and alter CBF; changes in neural activity cause changes in cerebral energy metabolism and CBF; neurogenic control of CBF occurs by sympathetic innervation. Regional differences in vascular response to changes in PaCO2 have been reported, indicating regional differences in cerebral vascular tone. Relations between CBF and CBV during changes in PaCO2 and during changes in neural activity were in good agreement with Poiseuille's law. The mechanisms of vascular response to neural activation and deactivation were independent on those of responses to PaCO2 changes. CBV in a brain region is the sum of three components: arterial, capillary and venous blood volumes. It has been reported that the arterial blood volume fraction is approximately 30% in humans and that changes in human CBV during changes in PaCO2 are caused by changes in arterial blood volume without changes in venous blood volume. These findings should be considered in future studies of the pathophysiology of cerebrovascular diseases. (author) 136 refs

  8. Application of positron emission tomography in neurophysiology

    PET measures the distribution of positron-emitting radiotracers in the organs of living subjects, by means of the angular correlation of the gamma-rays originating from positron annihilation. The UBC/TRIUMF Program focusses the technique on measurements of brain physiology, and radio-labelled tracers have been developed for measurements of regional cerebral glucose metabolism, regional cerebral blood flow, regional synthesis of dopamine neurotransmitter, and regional density and kinetics of dopamine receptor sites. Data have been obtained on normal physiology, and deranged physiology in Alzheimer's disease, Huntington's disease, Parkinson's disease, and astrocytoma brain tumors undergoing pion radiation treatment

  9. Perspectives for positron emission tomography with RPCs

    Full text: The basis of PET (Positron Emission Tomography) consists on the administration of a radioactive isotope attached to a tracer that permits to reveal its molecular pathways in a human body. A 3-D Complete-Body-Scan is desired in order to minimize the radiation dose to the patient and to increase the sensitivity of the axial field of view (FOV). A major candidate for gamma pair detection in 3-D Complete- Body-Scan are the RPCs (Resistive Plate Counters). They consist in a longitudinal microstrip grid 1.5 mm thick, spaced at 1 mm. The grid is placed between a large electric resistive glass anode and an aluminum cathode. The gap, around 300 m, is filled with a special gas and is polarized at around 6 kV. Every microstrip is equipped with high-speed preamplifier at both ends, allowing time of flight measurements. The RPC are solely tracking devices enjoying a large density of detection units. By construction they are able to provide an extremely large transverse resolution, the collecting leads being some 2.5 mm spaced. The longitudinal resolution is less sensitive, depending on the speed of the time of flight electronics. At this moment we estimate a 20 mm resolution. The RPCs present two main features: large longitudinal dimension and large transversal resolution which made them ideal for complete-body-scan devices. These peculiar features are the keys of a RPCs tomographic device. The evaluation of RPCs for 3-D Complete-Body-Scan followed two steps, the simulation of data acquisition and the image reconstruction. We choose the detecting base unit like a RPC, 2 meters long and 0.5 meters wide. According to previous assumptions this plate has a transverse resolution of 256 detection units and a longitudinal resolution of 100. (The transversal step is around 2 mm and the longitudinal step about 20 mm). Several base units are assembled to form different detecting structures. Two plates form an open detection structure like a sandwich. Four and six plates are

  10. Positron emission tomography in colorectal cancer;Tomografia por emissao de positron no cancer colorretal

    Gabure, Jose Luiz de Carvalho; Bacega, Marcelle Francine [Universidade Cidade de Sao Paulo (UNICID), Sao Paulo, SP (Brazil); Racy, Douglas Jorge; Lima, Rodrigo Vaz de; Rigo, Leticia, E-mail: letirigo3@hotmail.co [Med Imagem Diagnosticos por Imagem, Sao Paulo, SP (Brazil)

    2009-12-15

    After an introduction on the physical and biological basics of positron emission tomography, this paper reviews the current status of PET imaging using the glucose analogue FDG in colorectal cancer. The use of PET-FDG is reviewed for detection, initial staging, therapy monitoring and staging of disease relapse. (author)

  11. Physical and technical basis of positron emission tomography (PET)

    Positron emission tomography utilizes the annihilation of positrons, generating pairs of gamma quanta which are emitted in opposing directions. 'Electronic collimation' is performed by coincident detection of both quanta. Thus, there is no need for mechanical collimators and no limiting connection between sensitivity and spatial resolution. Transversal tomograms are reconstructed from the projection data by means of highly sophisticated data processing. The half life of the most positron emitters used in medical applications is short and of the order of some minutes. Therefore, many positron emitters have to be produced on-side by means of a cyclotron. PET is superior to SPECT with respect to physical and technical aspects, but the high costs of PET limit its wide-spread use up to now. (orig.)

  12. Improved sampling in positron emission tomography

    The biomedical research performed with the Donner 280-Crystal Positron Tomograph requires data acquisition times of five seconds or less and the ability to gate the data acquisition for periods during the cardiac cycle when the heart is nearly at rest. These requirements pose severe restrictions on the amount of detector movement and have motivated the search for a scheme that improves lateral sampling with a minimum number of detector positions. A new approach, developed by our group, involves only two positions of the detector assembly and increases lateral sampling uniformly by a factor of two. This new approach is referred as clamshell sampling. To test clamshell sampling we performed Monte Carlo computer simulations of data acquisition with the new geometry. Hot spots of varying sizes and separation comprise the model used in a geometry scaled to test imaging the human head with the Donner 280-Crystal Positron Tomograph

  13. Liquid Xenon Detectors for Positron Emission Tomography

    Miceli, A.; Amaudruz, P.; Benard, F.; Bryman, D. A.; Kurchaninov, L.; Martin, J. P.; Muennich, A.; Retiere, F.; Ruth, T J.; Sossi, V.; A.J. Stoessl

    2011-01-01

    PET is a functional imaging technique based on detection of annihilation photons following beta decay producing positrons. In this paper, we present the concept of a new PET system for preclinical applications consisting of a ring of twelve time projection chambers filled with liquid xenon viewed by avalanche photodiodes. Simultaneous measurement of ionization charge and scintillation light leads to a significant improvement to spatial resolution, image quality, and sensitivity. Simulated per...

  14. A simplified intravenous glucose loading protocol for fluorine-18 fluorodeoxyglucose cardiac single-photon emission tomography

    In a population of 209 patients undergoing dual-isotope single acquisition (DISA) FDG/sestamibi (MIBI) SPET, we describe the improvements in both image quality and time efficiency using a new short, simple glucose/insulin/potassium (GIK) infusion protocol prior to FDG injection as compared to a conventional oral glucose loading protocol. DISA FDG/MIBI SPET scans were performed in 111 nondiabetic patients after oral loading with 50 g of glucose (group 1). Ninety-eight consecutive nondiabetic patients were subsequently scanned following preparation with a fixed-concentration GIK infusion administered at a standardized rate (group 2). A three-point grading scale was used to assess image quality. The time to FDG injection following glucose administration was significantly shorter for the group 2 patients (39.9±15.6 min; range 20-105 min) than for the group 1 patients (99.5±30.3 min; range 56-270 min) (P<0.0001), representing a 1-h decrease in patient preparation time. More of the group 1 patients (n=30; 27%) required supplemental intravenous boluses of regular insulin than did the group 2 patients (n=13; 13%) (P<0.02). There were more excellent and good quality graded images using the GIK method (group 2) than the more traditional oral loading protocol (group 1) (P<0.02). Nine of 111 scans (8%) in group 1 were uninterpretable, whereas only one of 98 scans (1%) in group 2 was uninterpretable. Standardized infusion of a fixed concentration of GIK prior to FDG administration and continued during myocardial FDG uptake is an effective yet simple method of obtaining consistently good to excellent quality FDG SPET cardiac scans. It is preferable to conventional oral glucose loading due to decreased patient preparation time and improved image quality. The technique is safe and should improve both the clinical use and the cost-effectiveness of FDG SPET imaging for the identification of injured but viable myocardium. (orig.)

  15. Liquid Xenon Detectors for Positron Emission Tomography

    PET is a functional imaging technique based on detection of annihilation photons following beta decay producing positrons. In this paper, we present the concept of a new PET system for preclinical applications consisting of a ring of twelve time projection chambers filled with liquid xenon viewed by avalanche photodiodes. Simultaneous measurement of ionization charge and scintillation light leads to a significant improvement to spatial resolution, image quality, and sensitivity. Simulated performance shows that an energy resolution of < 10% (FWHM) and a sensitivity of 15% are achievable. First tests with a prototype TPC indicate position resolution < 1 mm (FWHM).

  16. Positron-emission tomography and cerebral metabolism

    In addition to the fact that radio-isotopes allow iso-atom labelling, they are short-lived and consequently may be injected into humans without serious problems of radiation damage. They disintegrate by emitting positrons which can be detected by external counting by virtue of the two 511 keV gamma rays emitted at the same time in opposite directions. These properties are used for tomographic detection and permit quantitative measurements of the radio-activity method will be described. The first concerns the transport of amino-acids into the brain, the second, the metabolism of psychoactive drugs. (orig./VJ)

  17. Liquid Xenon Detectors for Positron Emission Tomography

    Miceli, A; Benard, F; Bryman, D A; Kurchaninov, L; Martin, J P; Muennich, A; Retiere, F; Ruth, T J; Sossi, V; Stoessl, A J

    2011-01-01

    PET is a functional imaging technique based on detection of annihilation photons following beta decay producing positrons. In this paper, we present the concept of a new PET system for preclinical applications consisting of a ring of twelve time projection chambers filled with liquid xenon viewed by avalanche photodiodes. Simultaneous measurement of ionization charge and scintillation light leads to a significant improvement to spatial resolution, image quality, and sensitivity. Simulated performance shows that an energy resolution of <10% (FWHM) and a sensitivity of 15% are achievable. First tests with a prototype TPC indicate position resolution <1 mm (FWHM).

  18. Physiopathology of ischemic strokes: the input of positron emission tomography

    The tomography by positrons emissions has brought essential physiological and pathological knowledge relative to cerebral vascular accidents in the acute phase, because it is possible to measure the cerebral blood flow, the oxygen extraction rate and the local oxygen consumption. (N.C.)

  19. Advance of molecular imaging with positron emission tomography

    Molecular imaging with positron emission tomography (PET) is an important field of molecular imaging. This article summarizes the fundamental of PET molecular imaging technique and its application in protein function, gene expression and gene therapy, receptor imaging, and blood-flow infusion and metabolism imaging. (authors)

  20. Amyloid-β positron emission tomography imaging probes

    Kepe, Vladimir; Moghbel, Mateen C; Långström, Bengt;

    2013-01-01

    number of factors appear to preclude these probes from clinical utilization. As the available "amyloid specific" positron emission tomography imaging probes have failed to demonstrate diagnostic value and have shown limited utility for monitoring therapeutic interventions in humans, a debate on their...

  1. Skeletal muscle perfusion measured by positron emission tomography during exercise

    Ament, W; Lubbers, J; Rakhorst, G; Vaalburg, W; Verkerke, GJ; Paans, AMJ; Willemsen, ATM

    1998-01-01

    The applicability of (H2O)-O-15-positron emission tomographic (PET) imaging for the assessment of skeletal muscle perfusion during exercise was investigated in five healthy subjects performing intermittent isometric contractions on a calf ergometer. The workload of the left calf muscles was kept con

  2. MR imaging and positron emission tomography of cortical heterotopia

    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 18F-2-deoxyglucose

  3. Positron emission tomography/computerized tomography in lung cancer

    Sahiner, Ilgin; Vural, Gulin Ucmak

    2014-01-01

    Positron emission tomography (PET) using 2-(18F)-flouro-2-deoxy-D-glucose (FDG) has emerged as a useful tool in the clinical work-up of lung cancer. This review article provides an overview of applications of PET in diagnosis, staging, treatment response evaluation, radiotherapy planning, recurrence assessment and prognostication of lung cancer.

  4. 3D fast reconstruction in positron emission tomography

    The issue of long reconstruction times in positron emission tomography (PET) has been addressed from several points of view, resulting in an affordable dedicated system capable of handling routine 3D reconstructions in a few minutes per frame : on the hardware side using fast processors and a parallel architecture, and on the software side, using efficient implementation of computationally less intensive algorithms

  5. Standardized uptake values of fluorine-18 fluorodeoxyglucose: the value of different normalization procedures

    Schomburg, A. [Dept. of Nuclear Medicine, PET Center Bonn, Univ. Bonn (Germany); Bender, H. [Dept. of Nuclear Medicine, PET Center Bonn, Univ. Bonn (Germany); Reichel, C. [Dept. of Internal Medicine, PET Center Bonn, Univ. Bonn (Germany); Sommer, T. [Dept. of Radiology, PET Center Bonn, Univ. Bonn (Germany); Ruhlmann, J. [Dept. of Nuclear Medicine, PET Center Bonn, Univ. Bonn (Germany); Kozak, B. [Dept. of Nuclear Medicine, PET Center Bonn, Univ. Bonn (Germany); Biersack, H.J. [Dept. of Nuclear Medicine, PET Center Bonn, Univ. Bonn (Germany)

    1996-05-01

    While the evident advantages of absolute metabolic rate determinations cannot be equalled by static image analysis of fluorine-18 fluorodexyglucose positron emission tomographic (FDG PET) studies, various algorithms for the normalization of static FDG uptake values have been proposed. This study was performed to compare different normalization procedures in terms of dependency on individual patient characteristics. Standardized FDG uptake values (SUVs) were calculated for liver and lung tissue in 126 patients studied with whole-body FDG PET. Uptake values were normalized for total body weight, lean body mass and body surface area. Ranges, means, medians, standard deviations and variation coefficients of these SUV parameters were calculated and their interdependency with total body weight, lean body mass, body surface area, patient height and blood sugar levels was calculated by means of regression analysis. Standardized FDG uptake values normalized for body surface area were clearly superior to SUV parameters normalized for total body weight or lean body mass. Variation and correlation coefficients of body surface area-normalized uptake values were minimal when compared with SUV parameters derived from the other normalization procedures. Normalization for total body weight resulted in uptake values still dependent on body weight and blood sugar levels, while normalization for lean body mass did not eliminate the positive correlation with lean body mass and patient height. It is concluded that normalization of FDG uptake values for body surface area is less dependent on the individual patient characteristics than are FDG uptake values normalized for other parameters, and therefore appears to be preferable for FDG PET studies in oncology. (orig.)

  6. Standardized uptake values of fluorine-18 fluorodeoxyglucose: the value of different normalization procedures

    While the evident advantages of absolute metabolic rate determinations cannot be equalled by static image analysis of fluorine-18 fluorodexyglucose positron emission tomographic (FDG PET) studies, various algorithms for the normalization of static FDG uptake values have been proposed. This study was performed to compare different normalization procedures in terms of dependency on individual patient characteristics. Standardized FDG uptake values (SUVs) were calculated for liver and lung tissue in 126 patients studied with whole-body FDG PET. Uptake values were normalized for total body weight, lean body mass and body surface area. Ranges, means, medians, standard deviations and variation coefficients of these SUV parameters were calculated and their interdependency with total body weight, lean body mass, body surface area, patient height and blood sugar levels was calculated by means of regression analysis. Standardized FDG uptake values normalized for body surface area were clearly superior to SUV parameters normalized for total body weight or lean body mass. Variation and correlation coefficients of body surface area-normalized uptake values were minimal when compared with SUV parameters derived from the other normalization procedures. Normalization for total body weight resulted in uptake values still dependent on body weight and blood sugar levels, while normalization for lean body mass did not eliminate the positive correlation with lean body mass and patient height. It is concluded that normalization of FDG uptake values for body surface area is less dependent on the individual patient characteristics than are FDG uptake values normalized for other parameters, and therefore appears to be preferable for FDG PET studies in oncology. (orig.)

  7. Positron emission particle tracking-Application and labelling techniques

    David J.Parker; Xianfeng Fan

    2008-01-01

    The positron emission particle tracking (PEPT) technique has been widely used in science and engineering to obtain detailed information on the motion and flow fields of fluids or granular materials in multiphase systems, for example, fluids in rock cracks, chemical reactors and food processors; dynamic behaviour of granular materials in chemical reactors, granulators, mixers, dryers, rotating kilns and ball mills. The information obtained by the PEPT technique can be used to optimise the design, operational conditions for a wide range of industrial process systems, and to evaluate modelling work. The technique is based on tracking radioactively labelled particles (up to three particles) by detecting the pairs of back-to-back 511 ke V -γ-rays arising from annihilation of emitted positrons. It therefore involves a positron camera, location algorithms for calculating the tracer location and speed, and tracer labelling techniques. This paper will review the particle tracking technique from tracking algorithm, tracer labelling to their application.

  8. Introducing Positron Emission Tomography (PET) in Clinical Practice

    Janevik-Ivanovska, Emilija; Avmedovski, Fatmir; Yamamoto, Mayumi; Bhonsle, Uday

    2009-01-01

    Positron emission tomography (PET) is a major diagnostic imaging technique predominantly used in determining the presence and severity of cancers, neurological conditions, and cardiovascular diseases. It is currently the most effective way to check for cancer recurrences and it offers significant advantages over other forms of imaging such as computed tomography (CT) or magnetic resonance imaging (MRI) scans in detecting disease in many patients. In the USA, an estimated 1 129 900 clinical PE...

  9. A novel clustering approach to positron emission particle tracking

    Wiggins, Cody; Santos, Roque; Ruggles, Arthur

    2016-03-01

    A novel approach to positron emission particle tracking is presented based on determining regions of space with high density of line of response crossing via clustering. The method is shown to be able to accurately track multiple particles in systems where the number of particles is unknown and in which particles can enter and leave the field of view of the scanning system. This method is explored in various environments and its parametric dependence is studied.

  10. Microfluidics for Positron Emission Tomography (PET) Imaging Probe Development

    Wang, Ming-Wei; Lin, Wei-Yu; Liu, Kan; Masterman-Smith, Michael; Shen, Clifton Kwang-Fu

    2010-01-01

    Due to increased needs for Positron Emission Tomography (PET) scanning, high demands for a wide variety of radiolabeled compounds will have to be met by exploiting novel radiochemistry and engineering technologies to improve the production and development of PET probes. The application of microfluidic reactors to perform radiosyntheses is currently attracting a great deal of interest because of their potential to deliver many advantages over conventional labeling systems. Microfluidic-based r...

  11. Positron emission tomography (PET) evaluation of abdominal aortic aneurysm (AAA)

    SakalihasanN, Natzi; Van Damme, Hendrik; Gomez, P.; RIGO, PIERRE; Lapiere, C. M.; Nusgens, Betty; Limet, Raymond

    2002-01-01

    Background: aneurysmal disease is associated with all inflammatory Cell infiltrate and enzymatic degradation of the vessel wall. Aim of the study: to detect increased metabolic activity in abdominal aortic aneurysms (AAA) by means of positron emission tomography (PET-imaging). Study design: twenty-six patients with AAA underwent PET-imaging Results: in tell patients, PET-imaging revealed increased, fluoro-deoxy-glucose (18-FDG) uptake at the level of the aneurysm. Patients with positive PET-i...

  12. A Case of Corticobasal Degeneration Studied with Positron Emission Tomography

    Nagasawa, H; T. Imamura; Nomura, H; Itoh, M; Ido, T.

    1993-01-01

    We measured cerebral blood flow, oxygen metabolism, glucose utilization, and dopamine metabolism in the brain of a patient with corticobasal degeneration using positron emission tomography (PET). The clinical picture is distinctive, comprising features referable to both cortical and basal ganglionic dysfunction. Brain imagings of glucose and dopamine metabolism can demonstrate greater abnormalities in the cerebral cortex and in the striatum contralateral to the more affected side than those o...

  13. Nonhuman Primate Positron Emission Tomography Neuroimaging in Drug Abuse Research

    Howell, Leonard Lee; Murnane, Kevin Sean

    2011-01-01

    Positron emission tomography (PET) neuroimaging in nonhuman primates has led to significant advances in our current understanding of the neurobiology and treatment of stimulant addiction in humans. PET neuroimaging has defined the in vivo biodistribution and pharmacokinetics of abused drugs and related these findings to the time course of behavioral effects associated with their addictive properties. With novel radiotracers and enhanced resolution, PET neuroimaging techniques have also charac...

  14. ENVISION, developing Positron Emission Tomography for particle therapy

    2013-01-01

    Particle therapy is an advanced technique of cancer radiation therapy, using protons or other ions to target the cancerous mass. ENVISION aims at developing medical imaging tools to improve the dose delivery to the patient, to ensure a safer and more effective treatment. The animation illustrates the use of Positron Emission Tomography (PET) for monitoring the dose during treatment. Produced by: CERN KT/Life Sciences and ENVISION Project Management: Manuela Cirilli 3D animation: Jeroen Huijben, Nymus3d

  15. Positron emission holography: A new method of creating positron camera images

    By simulating the presence of a Fresnel zone plate in a camera designed for positron emission tomography (PET), a hologram can be synthesized which permits full three-dimensional images of the positron distribution in the original object to be rapidly constructed. The method requires no additional apparatus to a standard PET system, which is also operated in the usual way. The trajectory of each photon pair, detected in coincidence, is weighted as if it had passed through a zone plate optimised to suit the problem, before recording its intercept with a (single) plane to produce the hologram. The final image is created by calculating the diffraction pattern of monochromatic light passed through this hologram; it may also be created optically. The method is described in detail and its attractions discussed. Results are presented of some simple objects obtained from holograms produced from PET camera data, in comparison with images created by conventional back-projection processing of the same data. (orig.)

  16. Positron emission tomography with [18F]FDOPA and [18F]FDG in the imaging of small cell lung carcinoma: preliminary results

    Small cell lung carcinomas (SCLC) express neuroendocrine markers, and dihydroxyphenylalanine (DOPA) is known to accumulate in neuroendocrine tumours. This study was performed with the aim of evaluating the uptake of 3,4-dihydroxy-6-18F-fluoro-phenylalanine ([18F]FDOPA) by SCLC, based on comparison with the results of fluorine-18 fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) and standard imaging procedures. [18F]FDG PET and [18F]FDOPA PET were performed on four patients with newly diagnosed SCLC. There was agreement between the results of [18F]FDOPA PET and [18F]FDG PET in four tumoural sites out of 11, whereas [18F]FDG PET and standard imaging procedures were in full agreement. A semi-quantitative analysis based on standardised uptake values (SUVs) was performed in order to compare [18F]FDG and [18F]FDOPA tumour uptake. The median [18F]FDG SUVmax was 5.9 (with a 95% confidence interval from 4.4 to 9.2), while the median [18F]FDOPA SUVmax was 1.9 (with a 95% confidence interval from 1.6 to 3.8). The difference between [18F]FDG SUVmax and [18F]FDOPA SUVmax was significant (P18F]FDOPA PET appeared less sensitive than [18F]FDG PET and standard imaging procedures in the staging of SCLC. No clear relation between [18F]FDOPA uptake and positivity of neuroendocrine markers on immunohistochemistry emerged from these preliminary results; however, since [18F]FDOPA uptake may reflect better differentiation of the tumour, and possibly a better prognosis, this point warrants clarification in a larger study. (orig.)

  17. Use of positron emission tomography scan response to guide treatment change for locally advanced gastric cancer: the Memorial Sloan Kettering Cancer Center experience

    Won, Elizabeth; Shah, Manish A.; Schöder, Heiko; Strong, Vivian E.; Coit, Daniel G.; Brennan, Murray F.; Kelsen, David P.; Janjigian, Yelena Y.; Tang, Laura H.; Capanu, Marinela; Rizk, Nabil P.; Allen, Peter J.; Bains, Manjit S.

    2016-01-01

    Background Early metabolic response on 18-fluorodeoxyglucose-positron emission tomography (FDG-PET) during neoadjuvant chemotherapy is PET non-responders have poor outcomes whether continuing chemotherapy or proceeding directly to surgery. Use of PET may identify early treatment failure, sparing patients from inactive therapy and allowing for crossover to alternative therapies. We examined the effectiveness of PET directed switching to salvage chemotherapy in the PET non-responders. Methods Patients with locally advanced resectable FDG-avid gastric or gastroesophageal junction (GEJ) adenocarcinoma received bevacizumab 15 mg/kg, epirubicin 50 mg/m2, cisplatin 60 mg/m2 day 1, and capecitabine 625 mg/m2 bid (ECX) every 21 days. PET scan was obtained at baseline and after cycle 1. PET responders, (i.e., ≥35% reduction in FDG uptake at the primary tumor) continued ECX + bev. Non-responders switched to docetaxel 30 mg/m2, irinotecan 50 mg/mg2 day 1 and 8 plus bevacizumab every 21 days for 2 cycles. Patients then underwent surgery. The primary objective was to improve the 2-year disease free survival (DFS) from 30% (historical control) to 53% in the non-responders. Results Twenty evaluable patients enrolled before the study closed for poor accrual. Eleven were PET responders and the 9 non-responders switched to the salvage regimen. With a median follow-up of 38.2 months, the 2-year DFS was 55% [95% confidence interval (CI), 30–85%] in responders compared with 56% in the non-responder group (95% CI, 20–80%, P=0.93). Conclusions The results suggest that changing chemotherapy regimens in PET non-responding patients may improve outcomes. Results from this pilot trial are hypothesis generating and suggest that PET directed neoadjuvant therapy merits evaluation in a larger trial.

  18. Role of 18F fluorodeoxyglucose positron emission tomography/computed tomography in the detection of recurrence in patients with cervical cancer

    Treatment of cervical cancer is usually surgery in the early stages and radiotherapy or chemoradiotherapy in more advanced stages of the disease. Recurrence may occur in multiple sites following primary treatment. Although recurrent metastatic disease is not curable, surgical treatment may be of great help if locoregional recurrence is detected early. Fluorine-18 Fluorodeoxyglucose positron emission tomography - computed tomography (18F FDG PET/CT) forms an important part of investigations in the diagnosis of clinically suspicious recurrent cervical cancer. To assess the role of 18F FDG PET/CT in diagnosing recurrence in patients with clinical suspicion of recurrent cervical cancer. We retrospectively evaluated 53 histopathologically proved patients of cervical cancer. All the patients had been treated with either surgery/radiation therapy with or without chemotherapy. The standard PET/CT acquisition protocol, with delayed post void static pelvic images, wherever required, was followed in all patients. Significant uptake of FDG in the lymph nodes was considered to be a recurrence suggestive of metastasis. Para-aortic lymph nodal involvement was considered to be distant metastasis. Any significant uptake in the lung nodule on FDG PET was evaluated either by histological confirmation, by taking fine needle aspiration cytology (FNAC), or by a follow-up chest CT done after three months. Of the 53 patients with clinically equivocal recurrence, FDG PET/CT suggested recurrence in 41 patients (local recurrence in 14 patients and distant recurrence/metastasis with or without local recurrence in 27 patients). It had a sensitivity of 97.5%, a specificity of 63.6%, positive predictive value of 90.9%, and negative predictive value of 87.5%. PET/CT appears to have an important role in detecting recurrence following primary treatment of cervical cancer. The high positive and negative predictive values of PET/CT may be helpful in planning management of recurrent cervical cancer

  19. Is Positron Emission Tomography Reliable to PredictPost-Chemotherapy Retroperitoneal Lymph NodeInvolvement in Advanced Germ Cell Tumors of theTestis?

    Ziya Akbulut

    2011-06-01

    Full Text Available PURPOSE: To evaluate if 18 fluorodeoxyglucose positron emission tomography(18FDG-PET scan could identify post-chemotherapy retroperitoneal lymphnode (RPLN involvement in advanced germ cell tumors of the testis.MATERIALS AND METHODS: Between January 2005 and January 2009, 16patients with advanced germ cell tumors of the testis underwent RPLNdissection (RPLND following chemotherapy. Before RPLND, abdominalcomputed tomography (CT, magnetic resonance imaging (MRI, and18FDG-PET were performed in all the patients. Findings on 18FDG-PETwere compared with pathological evaluation of the removed lymphatic tissue.RESULTS: Both abdominal CT and MRI demonstrated retroperitonealmasses in all the patients following chemotherapy. Although PET did not demonstrate any activity in 8 patients, tumor was detected histopathologically.In 1 patient, 18FDG-PET demonstrated activity; however, no tumor wasdetected on pathology. Of the remaining 7 patients, 18FDG-PET findingswere concordant with the histopathological findings. No activity wasdetected in 2 patients with no tumors whereas all 5 patients harboring viabletumor cells showed positive 18FDG-PET activity. In our study, sensitivityand specificity of 18FDG-PET in detecting RPLN involvement were detectedto be 39% and 67%, respectively.CONCLUSION: 18FDG-PET imaging does not seem to be a reliable methodin detecting RPLN involvement in advanced germ cell tumors of the testisfollowing chemotherapy. Therefore, we neither recommend routine use of18FDG-PET scanning nor decide the treatment work-up by solely relying onthe 18FDG-PET findings in this patient group.

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

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

  1. Positron emission tomography and cerebral metabolism

    The association of new methods of labelling with short lived radioisotopes and of visualisation 'in vivo' of these labelled molecules by emission tomography, provide the possibility of studying brain metabolism at different levels. Two examples will illustrate the possibilities of this methodology. Cerebral metabolism of methionine-11C in phenylketonutic patients: The cerebral uptake of methionine was measured in 24 PKU children aged 1 to 40 months on a low protein diet. Ten of them were examined twice at intervals of several months. Stopping the diet for one week leads to an increase in blood phenylalanine and to a significant important decrease in brain uptake of labelled methionine. Futhermore, for children under treatment having a low phenylalanine blood concentration, brain uptake of methionine decreases with age between 1 and 40 months. These results suggest that the treatment of this disease should be started as soon as possible after birth. Cerebral metabolism of psychoactive drugs: The study of the brain distribution and kinetics of psychoactive drugs may help in understanding their mode of action. Chlorpromazine- 11C was administered i.v. to schyzophrenic patients not previously treated with neuroleptics. In all patients the brain uptake of the drug was high and rapid, and was localized mainly in the grey matter, probably in proportion to the blood flow. Non-specific binding of this drug to brain proteins prevented visualization of specific binding to dopaminergic or αnor-adrenergic receptors. Specific receptor binding of benzodiazepines was however visualized in the brain of baboons after injection of 11C-flunitrazepam (specific activity = 600 Ci/μmole) and subsequent displacement of this radioactive ligand by a pharmacological dose of Lorazepam

  2. Clinical cardiac positron emission tomography: State of the art

    Cardiac positron emission tomography (PET) has evolved rapidly from a relatively esoteric research tool into clinical applications providing unique, quantitative information on myocardial perfusion, metabolism, and cell membrane function and having a potentially significant impact on cardiovascular medicine. Although there are many different positron radionuclides for imaging diverse myocardial behavior, three radionuclides have reached accepted clinical utility. Cardiac PET using nitrogen-13-ammonia, rubidium-82, and fluoro-18-deoxyglucose has proved accurate and definitive in multiple university and private-practice sites for diagnosing and assessing severity and location of coronary artery disease in symptomatic or asymptomatic patients, for identifying injured but viable myocardium potentially salvageable by revascularization, and for ruling out clinically significant coronary artery stenosis with a high specificity in patients who might otherwise undergo coronary arteriography to document the absence of significant disease. 89 references

  3. Investigation of granular impact using positron emission particle tracking

    Marston, Jeremy O.

    2015-04-01

    We present results from an experimental study of granular impact using a combination of high-speed video and positron emission particle tracking (PEPT). The PEPT technique exploits the annihilation of photons from positron decay to determine the position of tracer particles either inside a small granular bed or attached to the object which impacts the bed. We use dense spheres as impactors and the granular beds are comprised of glass beads which are fluidised to achieve a range of different initial packing states. For the first time, we have simultaneously investigated both the trajectory of the sphere, the motion of particles in a 3-D granular bed and particles which jump into the resultant jet, which arises from the collapse of the cavity formed by the impacting sphere.

  4. Significance of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) for detection of renal cell carcinoma and immunohistochemical glucose transporter 1 (GLUT-1) expression in the cancer

    Positron emission tomography (PET) is now primarily used in oncological indication owing to the successful application of fluorine-18 fluorodeoxyglucose (FDG) in an increasing number of clinical indications. Glucose transporter 1 (GLUT-1) is recognized as a major early marker of cellular malignant transformation. The aims of this study were to assess whether FDG-PET is a useful diagnostic tool for renal cell carcinoma and to compare the pathologic characteristics. Nineteen consecutive patients who had renal cell carcinoma were examined using FDG-PET preoperatively. The results of PET were then compared to the histology obtained after radical surgery and the immunoreactivity of GLUT-1 was also studied. Pathologic examination confirmed that all 19 patients suffered from renal cell carcinoma. Increased FDG uptake was found in six of the 19 patients (31.5%). The immmunohistochemical examination of GLUT-1 in renal cell carcinoma produced different results in each patient. There was no correlation with GLUT-1 immunoreactivity and FDG-PET positivity. These results suggest that FDG-PET may not be a useful diagnostic tool for renal cell carcinoma. (author)

  5. The Role of Dual-Time Combined 18-Fluorideoxyglucose Positron Emission Tomography and Computed Tomography in the Staging and Restaging Workup of Locally Advanced Rectal Cancer, Treated With Preoperative Chemoradiation Therapy and Radical Surgery

    Purpose: In patients with locally advanced rectal cancer (LARC) staging and, after preoperative chemo-radiation therapy (CRT), restaging workup could be useful to tailor therapeutic approaches. Fluorine-18-fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) is a promising tool for monitoring the effect of antitumor therapy. This study was aimed to evaluate the possible role of dual time sequential FDG-PET scans in the staging and restaging workup of LARC. Methods and Materials: Eighty-seven consecutive patients with LARC were enrolled. CRT consisted of external-beam intensified radiotherapy (concurrent boost), with concomitant chemotherapy PVI 5-FU (300mg/m2/day) followed 8-10 weeks later by surgery. All patients underwent [18F]FDG-PET/CT before and 5-6 weeks later after the completion of CRT. Measurements of FDG uptake (SUVmax), and percentage of SUVmax difference (Response Index = RI) between pre- and post-CRT [18F]FDG-PET scans were evaluated. Results: Six of 87 patients were excluded due to protocol deviation. Following CRT, 40/81 patients (49%) were classified as responders according to Mandard's criteria (TRG1-2). The mean pre-CRT SUVmax was significantly higher than post-CRT (15.8, vs 5.9; p 18F]FDG-PET in the restaging workup after preoperative CRT in LARC. RI seems the best predictor to identify CRT response.

  6. Methods and clinical applications of positron emission tomography in endocrinology

    Positron emission tomography (PET) allows to detect in coincidence photons issued from annihilation between positrons and electrons nearby situated. Tomographic detection (plane by plane) and tomographic reconstruction will lead to the quantitation of radioactive distribution per voxel, in the organ of interest. Recent tomographs can acquire simultaneously several transaxial slices, with a high sensitivity and a spatial resolution of 3-5 mm. Commonly used positron emitters have a short half-life: 2, 10, 20 and 110 min for 150, 13N, 11C and 18F, respectively. The use of these isotopes requires on line production of radionuclides and synthesis of selected molecules. In endocrinology, PET allows among others to study noninvasively the receptor density of hormonodependent neoplasms such as breast, uterus, prostate tumors and prolactinomas. These last tumors represent a particular entity because of several combined characteristics: high turnover rate of amino acids, high density of dopaminergic receptors and response to bromocriptine (analogue of dopamine inhibiting the secretion of prolactine) in relation to the level of receptors. Because PET permits to evaluate the density of dopaminergic receptors and the metabolism of amino acids, theoretical response of the prolactinoma to bromocriptin can be predicted, the achieved therapeutic efficacy can be estimated and the long-term follow up of tumor growth can be assessed. This example illustrates the clinical value of PET in endocrinology

  7. Design of a volume-imaging positron emission tomograph

    Progress is reported in several areas of design of a positron volume imaging tomograph. As a means of increasing the volume imaged and the detector packing fraction, a lens system of detector light coupling is considered. A prototype layered scintillator detector demonstrates improved spatial resolution due to a unique Compton rejection capability.The conceptual design of a new mechanism for measuring scattered radiation during emission scans has been tested by Monte Carlo simulation. The problem of how to use effectively the resulting sampled scattered radiation projections is presented and discussed

  8. Positron Emission Tomography Imaging of Regional Pulmonary Perfusion and Ventilation

    Musch, Guido; Venegas, Jose G.

    2005-01-01

    Positron emission tomography (PET) imaging is a noninvasive, quantitative method to assess pulmonary perfusion and ventilation in vivo. The core of this article focuses on the use of [13N]nitrogen (13N2) and PET to assess regional gas exchange. Regional perfusion and shunt can be measured with the 13N2–saline bolus infusion technique. A bolus of 13N2, dissolved in saline solution, is injected intravenously at the start of a brief apnea, while the tracer kinetics in the lung is measured by a s...

  9. The investigation of cerebrovascular disorders with positron emission tomography

    Positron emission tomography (PET) provides a non-invasive, regional, in vivo method to measure physiological parameters including cerebral blood flow, glucose and oxygen metabolism, blood volume, and pH. Measurement of these parameters not only enables a more complete understanding of the pathophysiology of acute cerebral ischemia and infarction, but provides objective criteria with which to better manage patients. This chapter will first discuss PET methodology and tracer techniques used in the investigation of patients with cerebrovascular disease and then describe the progress that has already resulted from applying these methods. 73 refs.; 7 figs

  10. Positron emission tomography: diagnostic imaging on a molecular level

    In human medicine positron emission tomography (PET) is a modern diagnostic imaging method. In the present paper we outline the physical principles of PET and give an overview over the main clinic fields where PET is being used, such as neurology, cardiology and oncology. Moreover, we present a current project in veterinary medicine (in collaboration with the Paul Scherrer Institute and the University Hospital Zurich), where a hypoxia tracer is applied to dogs and cats suffering from spontaneous tumors. Finally new developments in the field of PET were discussed