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Sample records for 18f-fluorodeoxyglucose positron emission

  1. Predicting Outcome in Patients with Rhabdomyosarcoma: Role of [{sup 18}F]Fluorodeoxyglucose Positron Emission Tomography

    SciTech Connect

    Casey, Dana L.; Wexler, Leonard H.; Fox, Josef J.; Dharmarajan, Kavita V.; Schoder, Heiko; Price, Alison N.; Wolden, Suzanne L.

    2014-12-01

    Purpose: To evaluate whether [{sup 18}F]fluorodeoxyglucose positron emission tomography (FDG-PET) response of the primary tumor after induction chemotherapy predicts outcomes in rhabdomyosarcoma (RMS). Methods and Materials: After excluding those with initial tumor resection, 107 patients who underwent FDG-PET after induction chemotherapy at Memorial Sloan Kettering Cancer Center from 2002 to 2013 were reviewed. Local control (LC), progression-free survival (PFS), and overall survival (OS) were calculated according to FDG-PET response and maximum standardized uptake value (SUV) at baseline (PET1/SUV1), after induction chemotherapy (PET2/SUV2), and after local therapy (PET3/SUV3). Receiver operator characteristic curves were used to determine the optimal cutoff for dichotomization of SUV1 and SUV2 values. Results: The SUV1 (<9.5 vs ≥9.5) was predictive of PFS (P=.02) and OS (P=.02), but not LC. After 12 weeks (median) of induction chemotherapy, 45 patients had negative PET2 scans and 62 had positive scans: 3-year PFS was 72% versus 44%, respectively (P=.01). The SUV2 (<1.5 vs ≥1.5) was similarly predictive of PFS (P=.005) and was associated with LC (P=.02) and OS (P=.03). A positive PET3 scan was predictive of worse PFS (P=.0009), LC (P=.05), and OS (P=.03). Conclusions: [{sup 18}F]fluorodeoxyglucose positron emission tomography is an early indicator of outcomes in patients with RMS. Future prospective trials may incorporate FDG-PET response data for risk-adapted therapy and early assessment of new treatment regimens.

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

    PubMed Central

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

    2015-01-01

    Endometriosis is a frequent and clinically relevant problem in young women. Laparoscopy is still the gold standard for the diagnosis of endometriosis, but frequently both morphologic and functional imaging techniques are involved in the diagnostic course before achieving a conclusive diagnosis. We present a case of a patient affected by infiltrating retroperitoneal endometriosis falsely interpreted as a malignant mass by contrast-enhanced magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography/computed tomography. PMID:26097425

  3. 18F-fluorodeoxyglucose positron-emission tomography-computed tomography to diagnose recurrent cancer

    PubMed Central

    You, J J; Cline, K J; Gu, C-S; Pritchard, K I; Dayes, I S; Gulenchyn, K Y; Inculet, R I; Dhesy-Thind, S K; Freeman, M A; Chan, A M; Julian, J A; Levine, M N

    2015-01-01

    Background: Sometimes the diagnosis of recurrent cancer in patients with a previous malignancy can be challenging. This prospective cohort study assessed the clinical utility of 18F-fluorodeoxyglucose positron-emission tomography-computed tomography (18F-FDG PET-CT) in the diagnosis of clinically suspected recurrence of cancer. Methods: Patients were eligible if cancer recurrence (non-small-cell lung (NSCL), breast, head and neck, ovarian, oesophageal, Hodgkin's or non-Hodgkin's lymphoma) was suspected clinically, and if conventional imaging was non-diagnostic. Clinicians were asked to indicate their management plan before and after 18F-FDG PET-CT scanning. The primary outcome was change in planned management after 18F-FDG PET-CT. Results: Between April 2009 and June 2011, 101 patients (age, median 65 years; 55% female) were enroled from four cancer centres in Ontario, Canada. Distribution by primary tumour type was: NSCL (55%), breast (19%), ovarian (10%), oesophageal (6%), lymphoma (6%), and head and neck (4%). Of the 99 subjects who underwent 18F-FDG PET-CT, planned management changed after 18F-FDG PET-CT in 52 subjects (53%, 95% confidence interval (CI), 42–63%); a major change in plan from no treatment to treatment was observed in 38 subjects (38%, 95% CI, 29–49%), and was typically associated with 18F-FDG PET-CT findings that were positive for recurrent cancer (37 subjects). After 3 months, the stated post-18F-FDG PET-CT management plan was actually completed in 88 subjects (89%, 95% CI, 81–94%). Conclusion: In patients with suspected cancer recurrence and conventional imaging that is non-diagnostic, 18F-FDG PET-CT often provides new information that leads to important changes in patient management. PMID:25942398

  4. Role of 18F-fluorodeoxyglucose positron emission tomography imaging in surgery for pancreatic cancer

    PubMed Central

    Wakabayashi, Hisao; Nishiyama, Yoshihiro; Otani, Tsuyoshi; Sano, Takanori; Yachida, Shinichi; Okano, Keiichi; Izuishi, Kunihiko; Suzuki, Yasuyuki

    2008-01-01

    AIM: To evaluate the role of positron emission tomo-graphy using 18F-fluorodeoxyglucose (FDG-PET) in the surgical management of patients with pancreatic cancer, including the diagnosis, staging, and selection of patients for the subsequent surgical treatment. METHODS: This study involved 53 patients with proven primary pancreatic cancer. The sensitivity of diagnosing the primary cancer was examined for FDG-PET, CT, cytological examination of the bile or pancreatic juice, and the serum levels of carcinoembrionic antigens (CEA) and carbohydrate antigen 19-9 (CA19-9). Next, the accuracy of staging was compared between FDG-PET and CT. Finally, FDG-PET was analyzed semiquantitatively using the standard uptake value (SUV). The impact of the SUV on patient management was evaluated by examining the correlations between the SUV and the histological findings of cancer. RESULTS: The sensitivity of FDG-PET, CT, cytological examination of the bile or pancreatic juice, and the serum levels of CEA and CA19-9 were 92.5%, 88.7%, 46.4%, 37.7% and 69.8%, respectively. In staging, FDG-PET was superior to CT only in diagnosing distant disease (bone metastasis). For local staging, the sensitivity of CT was better than that of FDG-PET. The SUV did not correlate with the pTNM stage, grades, invasions to the vessels and nerve, or with the size of the tumor. However, there was a statistically significant difference (4.6 ± 2.9 vs 7.8 ± 4.5, P = 0.024) in the SUV between patients with respectable and unresectable disease. CONCLUSION: FDG-PET is thus considered to be useful in the diagnosis of pancreatic cancer. However, regarding the staging of the disease, FDG-PET is not considered to be a sufficiently accurate diagnostic modality. Although the SUV does not correlate with the patho-histological prognostic factors, it may be useful in selecting patients who should undergo subsequent surgical treatment. PMID:18176963

  5. 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Other Thyroid Cancers: Medullary, Anaplastic, Lymphoma and So Forth

    PubMed Central

    Araz, Mine; Çayır, Derya

    2017-01-01

    Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (FDG) is used in staging, restaging, and evaluation of therapy response in many cancers as well as differentiated thyroid carcinomas especially in non-iodine avid variants. Its potential in less frequent thyroid tumors like medullary, anaplastic thyroid cancers, thyroid lymphoma and metastatic tumors of the thyroid however, is not well established yet. The aim of this review is to provide an overview on the recent applications and indications of 18F-FDG PET/CT in these tumors and to focus on the controversies in the clinical setting. PMID:28291004

  6. 18F-fluorodeoxyglucose positron emission tomography as a noninvasive method for the diagnosis of primary pulmonary artery sarcoma.

    PubMed

    Dias, Olívia Meira; Lombardi, Elisa Maria Siqueira; Canzian, Mauro; Soares Júnior, José; Vieira, Lucas de Oliveira; Terra Filho, Mário

    2011-01-01

    Pulmonary artery sarcomas are rare, difficult-to-diagnose tumors that frequently mimic chronic pulmonary thromboembolism. We report the cases of two female patients with clinical signs of dyspnea and lung masses associated with pulmonary artery filling defects on chest CT angiography. We performed 18F-fluorodeoxyglucose positron emission tomography, which revealed increased radiotracer uptake in those lesions. Pulmonary artery sarcoma was subsequently confirmed by anatomopathological examination. We emphasize the importance of this type of tomography as a noninvasive method for the diagnosis of these tumors.

  7. 18F-Fluorodeoxyglucose Positron Emission Tomography/Magnetic Resonance in Lymphoma

    PubMed Central

    Giraudo, Chiara; Raderer, Markus; Karanikas, Georgios; Weber, Michael; Kiesewetter, Barbara; Dolak, Werner; Simonitsch-Klupp, Ingrid; Mayerhoefer, Marius E.

    2016-01-01

    Objectives The aim of this study was to compare 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) (with and without diffusion-weighted imaging [DWI]) to 18F-FDG PET/computed tomography (CT), with regard to the assessment of nodal and extranodal involvement, in patients with Hodgkin lymphoma and non-Hodgkin lymphoma, without restriction to FDG-avid subytpes. Materials and Methods Patients with histologically proven lymphoma were enrolled in this prospective, institutional review board–approved study. After a single 18F-FDG injection, patients consecutively underwent 18F-FDG PET⁄CT and 18F-FDG PET/MR on the same day for staging or restaging. Three sets of images were analyzed separately: 18F-FDG PET/CT, 18F-FDG PET/MR without DWI, and 18F-FDG PET/MR with DWI. Region-based agreement and examination-based sensitivity and specificity were calculated for 18F-FDG PET/CT, 18F-FDG PET/MR without DWI, and 18F-FDG PET/MR DWI. Maximum and mean standardized uptake values (SUVmax, SUVmean) on 18F-FDG PET/CT and 18F-FDG PET/MR were compared and correlated with minimum and mean apparent diffusion coefficients (ADCmin, ADCmean). Results Thirty-four patients with a total of 40 examinations were included. Examination-based sensitivities for 18F-FDG PET/CT, 18F-FDG PET/MR, and 18F-FDG PET/MR DWI were 82.1%, 85.7%, and 100%, respectively; specificities were 100% for all 3 techniques; and accuracies were 87.5%, 90%, and 100%, respectively. 18F-FDG PET/CT was false negative in 5 of 40 examinations (all with mucosa-associated lymphoid tissue lymphoma), and 18F-FDG PET/MR (without DWI) was false negative in 4 of 40 examinations. Region-based percentages of agreement were 99% (κ, 0.95) between 18F-FDG PET/MR DWI and 18F-FDG PET/CT, 99.2% (κ, 0.96) between 18F-FDG PET/MR and 18F-FDG PET/CT, and 99.4% (κ, 0.97) between 18F-FDG PET/MR DWI and 18F-FDG PET/MR. There was a strong correlation between 18F-FDG PET/CT and 18F-FDG PET/MR for SUVmax (r = 0

  8. 18F-Fluoride and 18F-Fluorodeoxyglucose Positron Emission Tomography After Transient Ischemic Attack or Minor Ischemic Stroke

    PubMed Central

    Jenkins, William S. A.; Irkle, Agnese; Moss, Alastair; Sng, Greg; Forsythe, Rachael O.; Clark, Tim; Roberts, Gemma; Fletcher, Alison; Lucatelli, Christophe; Rudd, James H. F.; Davenport, Anthony P.; Mills, Nicholas L.; Al-Shahi Salman, Rustam; Dennis, Martin; Whiteley, William N.; van Beek, Edwin J. R.; Dweck, Marc R.; Newby, David E.

    2017-01-01

    Background— Combined positron emission tomography (PET) and computed tomography (CT) can assess both anatomy and biology of carotid atherosclerosis. We sought to assess whether 18F-fluoride or 18F-fluorodeoxyglucose can identify culprit and high-risk carotid plaque. Methods and Results— We performed 18F-fluoride and 18F-fluorodeoxyglucose PET/CT in 26 patients after recent transient ischemic attack or minor ischemic stroke: 18 patients with culprit carotid stenosis awaiting carotid endarterectomy and 8 controls without culprit carotid atheroma. We compared standardized uptake values in the clinically adjudicated culprit to the contralateral asymptomatic artery, and assessed the relationship between radiotracer uptake and plaque phenotype or predicted cardiovascular risk (ASSIGN score [Assessing Cardiovascular Risk Using SIGN Guidelines to Assign Preventive Treatment]). We also performed micro PET/CT and histological analysis of excised plaque. On histological and micro PET/CT analysis, 18F-fluoride selectively highlighted microcalcification. Carotid 18F-fluoride uptake was increased in clinically adjudicated culprit plaques compared with asymptomatic contralateral plaques (log10standardized uptake valuemean 0.29±0.10 versus 0.23±0.11, P=0.001) and compared with control patients (log10standardized uptake valuemean 0.29±0.10 versus 0.12±0.11, P=0.001). 18F-Fluoride uptake correlated with high-risk plaque features (remodeling index [r=0.53, P=0.003], plaque burden [r=0.51, P=0.004]), and predicted cardiovascular risk [r=0.65, P=0.002]). Carotid 18F-fluorodeoxyglucose uptake appeared to be increased in 7 of 16 culprit plaques, but no overall differences in uptake were observed in culprit versus contralateral plaques or control patients. However, 18F-fluorodeoxyglucose did correlate with predicted cardiovascular risk (r=0.53, P=0.019), but not with plaque phenotype. Conclusions— 18F-Fluoride PET/CT highlights culprit and phenotypically high-risk carotid plaque

  9. [(18)F]Fluorodeoxyglucose Positron Emission Tomography Reveals a Complete Remission of Refractory Metastatic Melanoma after Therapy with Ipilimumab.

    PubMed

    Yordanova, Anna; Schlenkhoff, Carl; Palmedo, Holger; Essler, Markus; Ahmadzadehfar, Hojjat

    2017-01-01

    Ipilimumab (YERVOY) is a monoclonal CTLA-4-antibody with anti-tumor-immunogenic effect and is used to treat malignant melanoma. In this case study, we present [(18)F]Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) images of a 37-year-old woman with metastatic melanoma, who was previously treated with interferon-alpha therapy and dacarbazine and still progressed. After four cycles of ipilimumab, there was a complete remission of the disease with no evidence of vital, FDG-positive tumor tissue. The follow-up for a total of 1 year confirmed the therapeutic success. This report demonstrates that FDG-PET/CT is a reliable imaging method for response monitoring in metastatic melanoma treated with ipilimumab.

  10. [18F]Fluorodeoxyglucose Positron Emission Tomography Reveals a Complete Remission of Refractory Metastatic Melanoma after Therapy with Ipilimumab

    PubMed Central

    Yordanova, Anna; Schlenkhoff, Carl; Palmedo, Holger; Essler, Markus; Ahmadzadehfar, Hojjat

    2017-01-01

    Ipilimumab (YERVOY) is a monoclonal CTLA-4-antibody with anti-tumor-immunogenic effect and is used to treat malignant melanoma. In this case study, we present [18F]Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) images of a 37-year-old woman with metastatic melanoma, who was previously treated with interferon-alpha therapy and dacarbazine and still progressed. After four cycles of ipilimumab, there was a complete remission of the disease with no evidence of vital, FDG-positive tumor tissue. The follow-up for a total of 1 year confirmed the therapeutic success. This report demonstrates that FDG-PET/CT is a reliable imaging method for response monitoring in metastatic melanoma treated with ipilimumab. PMID:28242993

  11. [18F] fluorodeoxyglucose-positron-emission tomography and MR imaging coregistration for presurgical evaluation of medically refractory epilepsy.

    PubMed

    Lee, K K; Salamon, N

    2009-11-01

    Epilepsy is a chronic disorder affecting approximately 1% of the population of the world. Approximately one third of patients with epilepsy remain refractory to medical therapy. For these patients, surgery is a curative option. In order for surgery to be considered, precise localization of the structural abnormality is needed. When MR imaging findings are normal, more sensitive techniques such as positron-emission tomography (PET) can help find the abnormality. Combining MR imaging and PET information increases the sensitivity of the presurgical evaluation. In this review, we discuss the clinical applications of coregistration of [(18)F] fluorodeoxyglucose (FDG)-PET with MR imaging for medically refractory epilepsy. Because FDG-PET/MR imaging coregistration has been a routine component of the presurgical evaluation for patients with epilepsy at our institution since 2004, we also included cases from our data base that exemplify the utility of this technology to obtain better postsurgical outcomes.

  12. Regional cerebral metabolic alterations in dementia of the Alzheimer type: positron emission tomography with (/sup 18/F)fluorodeoxyglucose

    SciTech Connect

    Friedland, R.P.; Budinger, T.F.; Ganz, E.; Yano, Y.; Mathis, C.A.; Koss, B.; Ober, B.A.; Huesman, R.H.; Derenzo, S.E.

    1983-08-01

    Alzheimer disease is the most common cause of dementia in adults. Despite recent advances in our understanding of its anatomy and chemistry, we remain largely ignorant of its pathogenesis, physiology, diagnosis, and treatment. Dynamic positron emission tomography using (/sup 18/F)fluorodeoxyglucose (FDG) was performed on the Donner 280-crystal ring in 10 subjects with dementia of the Alzheimer type and six healthy age-matched controls. Ratios comparing mean counts per resolution element in frontal, temporoparietal, and entire cortex regions in brain sections 10 mm thick obtained 40-70 min following FDG injection showed relatively less FDG uptake in the temporoparietal cortex bilaterally in all the Alzheimer subjects (p less than 0.01). Left-right alterations were less prominent than the anteroposterior changes. This diminished uptake was due to lowered rates of FDG use and suggests that the metabolic effects of Alzheimer disease are most concentrated in the temporoparietal cortex. Positron emission tomography is a most powerful tool for the noninvasive in vivo assessment of cerebral pathophysiology in dementia.

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

    PubMed Central

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

    2016-01-01

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

  14. Accuracy of 18F fluorodeoxyglucose positron emission tomography/computed tomography in staging of pediatric sarcomas.

    PubMed

    Tateishi, Ukihide; Hosono, Ako; Makimoto, Atsushi; Sakurada, Aine; Terauchi, Takashi; Arai, Yasuaki; Imai, Yutaka; Kim, Euishin Edmund

    2007-09-01

    The present study was conducted to clarify the diagnostic accuracy of 18F-fluoro-2-deoxy-D-glucose (18FDG) positron emission tomography (PET)/computed tomography (CT) in the staging in pediatric sarcomas. Fifty pediatric patients with histologically proven sarcomas who underwent 18FDG PET/CT before treatment were evaluated retrospectively for the detection of nodal and distant metastases. Diagnostic accuracy of 18FDG PET/CT in detecting nodal and distant metastases was compared with that of 18FDG PET and conventional imaging (CI). The images were reviewed and a diagnostic consensus was reached by 3 observers. REFERENCE standard was histologic examination in 15 patients and confirmation of an obvious progression in size of the lesions on follow-up examinations. Nodal metastasis was correctly assessed in 48 patients (96%) with PET/CT, in contrast to 43 patients (86%) with PET, and 46 patients (92%) with CI. Diagnostic accuracies of nodal metastasis in 3 modalities were similar. Using PET/CT, distant metastasis was correctly assigned in 43 patients (86%), whereas interpretation based on PET alone or CI revealed distant metastasis in 33 patients (66%) and 35 patients (70%), respectively. Diagnostic accuracy of distant metastasis with PET/CT was significantly higher than that of PET (P=0.002) or CI (P=0.008). False negative results regarding distant metastasis by PET/CT in 7 patients (14%) were caused by subcentimetric lesions (n=4), bone marrow lesion (n=2), and soft tissue lesions (n=1). PET/CT is more accurate and probably more cost-effective than PET alone or CI regarding distant metastasis in pediatric sarcomas.

  15. The utility of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography for detecting lung and esophagus multiple primary cancers involved in the larynx: Two case reports.

    PubMed

    Wang, Qinying; Chai, Liang; Zhou, Shuihong

    2015-01-01

    Multiple primary cancers involved in the larynx of differentiating synchronous multiple primary cancers from metastasis can often be very difficult, especially when they have the same histology. However, it is very important because the therapeutic approach is completely different. Clinical situations like this appear to be increasing as a result of the recent popular use of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography. Herein, we report two cases of multiple primary cancers involved in the larynx.

  16. Comparison between 18F-Fluorodeoxyglucose Positron Emission Tomography and Sentinel Lymph Node Biopsy for Regional Lymph Nodal Staging in Patients with Melanoma: A Review of the Literature

    PubMed Central

    Mirk, Paoletta; Treglia, Giorgio; Salsano, Marco; Basile, Pietro; Giordano, Alessandro; Bonomo, Lorenzo

    2011-01-01

    Aim. to compare 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) to sentinel lymph node biopsy (SLNB) for regional lymph nodal staging in patients with melanoma. Methods. We performed a literature review discussing original articles which compared FDG-PET to SLNB for regional lymph nodal staging in patients with melanoma. Results and Conclusions. There is consensus in the literature that FDG-PET cannot replace SLNB for regional lymph nodal staging in patients with melanoma. PMID:22242204

  17. 18F-fluorodeoxyglucose positron emission tomography and the risk of subsequent aortic complications in giant-cell arteritis

    PubMed Central

    de Boysson, Hubert; Liozon, Eric; Lambert, Marc; Parienti, Jean-Jacques; Artigues, Nicolas; Geffray, Loïk; Boutemy, Jonathan; Ollivier, Yann; Maigné, Gwénola; Ly, Kim; Huglo, Damien; Hachulla, Eric; Hatron, Pierre-Yves; Aouba, Achille; Manrique, Alain; Bienvenu, Boris

    2016-01-01

    Abstract Previous studies reported a 2- to 17-fold higher risk of aortic complications (dilation or dissection) in patients with giant-cell arteritis (GCA). We aimed to determine whether or not GCA patients with large-vessel involvement demonstrated by positron emission tomography with 18F-fluorodeoxyglucose combined with computed tomography (FDG-PET/CT) have a higher risk of aortic complications. We conducted a retrospective multicenter study between 1995 and 2014. Patients were included if they fulfilled at least 3 American College of Rheumatology criteria for GCA, or 2 criteria associated with extratemporal biopsy-proven giant-cell vasculitis; they underwent at least 1 FDG-PET/CT scan at diagnosis or during follow-up; and the morphology of the aorta was assessed by medical imaging at diagnosis. Patients with an aortic complication at the time of diagnosis were excluded. Of the 130 patients included [85 women (65%), median age 70 (50–86)], GCA was biopsy proven in 77 (59%). FDG-PET/CT was performed at diagnosis in 63 (48%) patients and during the follow-up period in the 67 (52%) remaining patients. FDG-PET/CT was positive in 38/63 (60%) patients at diagnosis and in 31/67 (46%) patients when performed during follow-up (P = NS). One hundred four patients (80%) underwent at least 1 morphological assessment of the aorta during follow-up. Nine (9%) patients developed aortic complications (dilation in all and dissection in 1) at a median time of 33 (6–129) months after diagnosis. All of them displayed large-vessel inflammation on previous FDG-PET/CT. A positive FDG-PET/CT was significantly associated with a higher risk of aortic complications (P = 0.004). In our study, a positive FDG-PET/CT was associated with an increased risk of aortic complications at 5 years. PMID:27367985

  18. [18F]Fluorodeoxyglucose uptake by positron emission tomography predicts outcomes for oropharyngeal and hypopharyngeal cancer treated with definitive radiotherapy

    PubMed Central

    Ishihara, Takeaki; Kitajima, Kazuhiro; Suenaga, Yuko; Ejima, Yasuo; Komatsu, Hirokazu; Otsuki,, Naoki; Nibu, Ken-ichi; kiyota, Naomi; Takahashi, Satoru; Sasaki, Ryohei

    2017-01-01

    ABSTRACT This study evaluated the prognostic significance of the maximum standardized uptake value of the primary site (pSUVmax) in 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans of patients with oropharyngeal or hypopharyngeal cancer who were treated using definitive radiotherapy. The study included 86 patients who were primarily treated with radiotherapy for oropharyngeal or hypopharyngeal cancer. Sixty-nine patients underwent concurrent chemotherapy. The associations between pre-treatment pSUVmax and treatment outcomes were evaluated. The most appropriate pSUVmax cut-off value for predicting disease-free survival (DFS) and local control (LC) was selected using receiver operating characteristic (ROC) curves. The median follow-up time for surviving patients was 60 months, while the median survival time in the entire patient cohort was 55 months. A pSUVmax cut-off value of 9.0 showed the best discriminative performance. Five-year OS and DFS rates were 65.9% and 60.0%, respectively. In univariate analyses, pSUVmax (p = 0.009), T-stage (p = 0.001), N-stage (p = 0.039), and clinical stage (p = 0.017) were identified as significant prognostic predictors for DFS. The multivariate analysis did not identify any statistically significant factors, but the association between pSUVmax and DFS was borderline significant (p = 0.055). Interestingly, pSUVmax was predictive of local controllability in T1–T2 disease (p = 0.024), but there was no significant association for T3–T4 disease (p = 0.735). In this study, pSUVmax was predictive of DFS and LC in patients with oropharyngeal or hypopharyngeal cancer that was treated with definitive radiotherapy. pSUVmax was strongly associated with LC in T1–T2 disease. PMID:28303058

  19. Occupational per-patient radiation dose from a conservative protocol for veterinary (18) F-fluorodeoxyglucose positron emission tomography.

    PubMed

    Martinez, Nicole E; Kraft, Susan L; Gibbons, Debra S; Arceneaux, Billie K; Stewart, Jeffrey A; Mama, Khursheed R; Johnson, Thomas E

    2012-01-01

    The occupational external radiation dose to human medical personnel from positron emission tomography (PET) radiopharmaceuticals has been documented, but to date no corresponding veterinary staff dose data are available. Electronic personal dosimeters (EPDs) were used in this study to measure the per-patient external radiation doses to veterinary staff using a PET/CT (PET combined with computed tomography) protocol in which the patient radiopharmaceutical dose was injected after anesthetic induction. Radiation doses were recorded for the nuclear medicine technologists, the on-duty anesthesiology technologist, and an occasional observer from 19 veterinary (18) F-fluorodeoxyglucose PET/CT studies. Patient mass range was 2.8 to 61.0 kg (22.3 kg mean) and injected activity averaged 6 MBq kg(-1) . The dose range received by nuclear medicine technologists per procedure was 0-30 μSv (9.1 μSv mean), by anesthetists 1-22 μSv (8.2 μSv mean), and by the observer 0-2 μSv (0.5 μSv mean). In both feline and canine studies, placement of the EPD on staff was a significant predictor of radiation dose. Additional significant predictors of staff radiation dose from canine studies included job position and injected activity. The per-patient occupational radiation doses to veterinary PET/CT technologists were slightly greater than those reported for human nuclear medicine PET/CT technologists, but were comparable to estimated radiation doses for nurses caring for nonambulatory human PET/CT patients. Efforts toward maintaining staff radiation doses as low as reasonably achievable (ALARA) will be important as veterinary PET/CT caseload increases.

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

    PubMed Central

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

    2017-01-01

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

  1. Different subregional metabolism patterns in patients with cerebellar ataxia by 18F-fluorodeoxyglucose positron emission tomography.

    PubMed

    Oh, Minyoung; Kim, Jae Seung; Oh, Jungsu S; Lee, Chong Sik; Chung, Sun Ju

    2017-01-01

    We evaluated cerebellar subregional metabolic alterations in patients with cerebellar ataxia, a representative disease involving the spinocerebellum. We retrospectively analyzed 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) images in 44 patients with multiple system atrophy of the cerebellar type (MSA-C), 9 patients with spinocerebellar ataxia (SCA) type 2, and 14 patients with SCA type 6 and compared with 15 patients with crossed cerebellar diaschisis (CCD) and 89 normal controls. Cerebellar subregional metabolism was assessed using 13 cerebellar subregions (bilateral anterior lobes [ANT], superior/mid/inferior posterior lobes [SUPP/MIDP/INFP], dentate nucleus [DN], anterior vermis [ANTV], and superior/inferior posterior vermis [SUPV/INFV]) to determine FDG uptake ratios. MSA-C and SCA type 2 showed severely decreased metabolic ratios in all cerebellar subregions compared to normal controls (ANT, 0.58 ± 0.08 and 0.50 ± 0.06 vs. 0.82 ± 0.07, respectively, p < 0.001). SCA type 6 showed lower metabolic ratios in almost all cerebellar subregions (ANT, 0.57 ± 0.06, p < 0.001) except INFV. Anterior-posterior lobe ratio measurements revealed that SCA type 2 (Right, 0.81 ± 0.05 vs. 0.88 ± 0.04, p < 0.001; Left, 0.83 ± 0.05 vs. 0.88 ± 0.04, p = 0.003) and SCA type 6 (Right, 0.72 ± 0.05 vs. 0.88 ± 0.04, p < 0.001; Left, 0.72 ± 0.05 vs. 0.88 ± 0.04, p < 0.001) showed preferential hypometabolism in the anterior lobe compared to normal controls, which was not observed in CCD and MSA-C. Asymmetric indices were higher in CCD and MSA-C than in normal controls (p < 0.001), whereas such differences were not found in SCA types 2 and 6. In summary, quantitative analysis of cerebellar subregional metabolism ratios revealed preferential involvement of the anterior lobe, corresponding to the spinocerebellum, in patients with cerebellar ataxia, whereas patients with CCD and MSA-C exhibited more asymmetric hypometabolism in the posterior lobe.

  2. Different subregional metabolism patterns in patients with cerebellar ataxia by 18F-fluorodeoxyglucose positron emission tomography

    PubMed Central

    Kim, Jae Seung; Oh, Jungsu S.; Lee, Chong Sik; Chung, Sun Ju

    2017-01-01

    We evaluated cerebellar subregional metabolic alterations in patients with cerebellar ataxia, a representative disease involving the spinocerebellum. We retrospectively analyzed 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) images in 44 patients with multiple system atrophy of the cerebellar type (MSA-C), 9 patients with spinocerebellar ataxia (SCA) type 2, and 14 patients with SCA type 6 and compared with 15 patients with crossed cerebellar diaschisis (CCD) and 89 normal controls. Cerebellar subregional metabolism was assessed using 13 cerebellar subregions (bilateral anterior lobes [ANT], superior/mid/inferior posterior lobes [SUPP/MIDP/INFP], dentate nucleus [DN], anterior vermis [ANTV], and superior/inferior posterior vermis [SUPV/INFV]) to determine FDG uptake ratios. MSA-C and SCA type 2 showed severely decreased metabolic ratios in all cerebellar subregions compared to normal controls (ANT, 0.58 ± 0.08 and 0.50 ± 0.06 vs. 0.82 ± 0.07, respectively, p < 0.001). SCA type 6 showed lower metabolic ratios in almost all cerebellar subregions (ANT, 0.57 ± 0.06, p < 0.001) except INFV. Anterior-posterior lobe ratio measurements revealed that SCA type 2 (Right, 0.81 ± 0.05 vs. 0.88 ± 0.04, p < 0.001; Left, 0.83 ± 0.05 vs. 0.88 ± 0.04, p = 0.003) and SCA type 6 (Right, 0.72 ± 0.05 vs. 0.88 ± 0.04, p < 0.001; Left, 0.72 ± 0.05 vs. 0.88 ± 0.04, p < 0.001) showed preferential hypometabolism in the anterior lobe compared to normal controls, which was not observed in CCD and MSA-C. Asymmetric indices were higher in CCD and MSA-C than in normal controls (p < 0.001), whereas such differences were not found in SCA types 2 and 6. In summary, quantitative analysis of cerebellar subregional metabolism ratios revealed preferential involvement of the anterior lobe, corresponding to the spinocerebellum, in patients with cerebellar ataxia, whereas patients with CCD and MSA-C exhibited more asymmetric hypometabolism in the posterior lobe. PMID:28319124

  3. Thoracic [18F]fluorodeoxyglucose uptake measured by positron emission tomography/computed tomography in pulmonary hypertension

    PubMed Central

    Frille, Armin; Steinhoff, Karen Geva; Hesse, Swen; Grachtrup, Sabine; Wald, Alexandra; Wirtz, Hubert; Sabri, Osama; Seyfarth, Hans-Juergen

    2016-01-01

    Abstract Positron emission tomography (PET) visualizes increased cellular [18F]fluorodeoxyglucose ([18F]FDG) uptake. Pulmonary hypertension (PH) is conceived of a proliferative disease of the lung vessels. Increased glucose uptake can be quantified as pulmonary [18F]FDG uptake via PET imaging. Because the angioproliferative mechanisms in PH are still in need of further description, the aim of the present study was to investigate whether [18F]FDG PET/CT imaging can elucidate these pathophysiologic mechanisms in different etiologies of PH. Patients (n = 109) with end-stage pulmonary disease being evaluated for lung transplant were included in this observational study. Mean standardized uptake value (SUVmean) of predefined regions of interest in lung parenchyma (LP), left (LV), and right ventricle (RV) of the heart, and SUVmax in pulmonary artery (PA) were determined and normalized to liver uptake. These SUV ratios (SUVRs) were compared with results from right heart catheterization (mean pulmonary artery pressure [mPAP], pulmonary vascular resistance [PVR]), and serum N-terminal pro-brain natriuretic peptide. Group comparisons were performed and Pearson correlation coefficients (r) were calculated. The [18F]FDG uptake ratios in LP, RV, RV/LV, and PA, but not in LV, were found to be significantly higher in both patients with mPAP ≥25 mm Hg (P = 0.013, P = 0.006, P = 0.049, P = 0.002, P = 0.68, respectively) and with PVR ≥480 dyn·s/cm5 (P < 0.001, P = 0.045, P < 0.001, P < 0.001, P = 0.26, respectively). The [18F]FDG uptake in these regions positively correlated also with mPAP, PVR, and N-terminal pro-brain natriuretic peptide. The SUVR of PA positively correlated with the SUVR of LP and RV (r = 0.55, r = 0.42, respectively). Pulmonary and cardiac [18F]FDG uptake in PET imaging positively correlated with the presence and severity of PH in patients with end-stage pulmonary disease. Increased glucose metabolism

  4. Endobronchial ultrasound-guided transbronchial needle aspiration of hilar and mediastinal lymph nodes detected on 18F-fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Minami, Daisuke; Takigawa, Nagio; Oda, Naohiro; Ninomiya, Takashi; Kubo, Toshio; Ohashi, Kadoaki; Sato, Akiko; Hotta, Katsuyuki; Tabata, Masahiro; Kaji, Mitsumasa; Tanimoto, Mitsune; Kiura, Katsuyuki

    2016-01-01

    Objective Endobronchial ultrasound-guided transbronchial needle aspiration is of diagnostic value in hilar/mediastinal (N1/N2) lymph node staging. We assessed the utility of endobronchial ultrasound-guided transbronchial needle aspiration in lung cancer patients with N1/N2 lymph nodes detected on 18F-fluorodeoxyglucose positron emission tomography/computed tomography. Methods Fifty lung cancer patients with N1/N2 disease on 18F-fluorodeoxyglucose positron emission tomography/computed tomography underwent endobronchial ultrasound-guided transbronchial needle aspiration for pathological lymph nodes between November 2012 and April 2015. The diagnostic performance of endobronchial ultrasound-guided transbronchial needle aspiration, lymph node site and size, number of needle passes and complications were evaluated retrospectively from patients' medical records. Malignancy was defined as a maximum standardized uptake value (SUVmax) >2.5. Results The median longest diameter of the 61 lymph nodes (29 subcarinal, 21 right lower paratracheal, 6 left lower paratracheal, 4 right hilar and 1 upper paratracheal) was 23.4 mm (range: 10.4–45.7); the median number of needle passes was 2 (range: 1–5). There were no severe complications. A definitive diagnosis was made by endobronchial ultrasound-guided transbronchial needle aspiration in 39 patients (31 adenocarcinomas, 3 small-cell carcinomas, 2 squamous-cell carcinomas, 3 large-cell neuroendocrine carcinomas). In the remaining 11 patients, the diagnosis was indefinite: insufficient endobronchial ultrasound-guided transbronchial needle aspiration material was collected in two patients and non-specific lymphadenopathy was confirmed by endobronchial ultrasound-guided transbronchial needle aspiration or thoracotomy in the other nine patients. The mean lymph node SUVmax was 7.09 (range: 2.90–26.9) and was significantly higher in true-positive than in false-positive nodes (P < 0.05, t-test). Non-specific lymphadenopathy was

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

    PubMed

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

    2015-01-01

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

  6. Potassium Chloride Infusion as the Cause of Altered Bio Distribution of 18F-Fluorodeoxyglucose on Whole-Body Positron Emission Tomography-Computed Tomography Scan

    PubMed Central

    Mahajan, Shimpi Madhuri; Natasha, Singh; Sudeshna, Maitra; Pereira, Melvika

    2017-01-01

    18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography is a standard diagnostic imaging tool in many types of cancer. Its physiological in vivo distribution includes the brain, liver, heart, kidneys, and urinary tract at 1 h after tracer injection. Skeletal muscle is known to show variable amounts of 18F-FDG uptake because it has a relatively high-glucose metabolism. We report a case of a 20-year-old patient with gross 18F-FDG uptake involving multiple muscle groups and its likely correlation to potassium chloride infusion before 18F-FDG injection. PMID:28217028

  7. Late metastatic recurrence of penile carcinoma after 10 years: Demonstration with 18F-fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Sharma, Punit

    2016-01-01

    Penile cancer is rare cancer. While inguinal and pelvic nodal metastasis is common, distant metastasis is rare. We here present the interesting case of a 59-year-old male patient with penile carcinoma, previously treated with penectomy and inguinal lymphadenectomy 10 years earlier. He presented with bone pains and given history of malignancy he was referred for an 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT). PET/CT demonstrated multiple 18F-FDG avid bone and lung metastases. No locoregional disease was seen. Biopsy from a lung nodule confirmed the diagnosis, and the patient was started on palliative chemotherapy. PMID:27385892

  8. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Scan in an Unusual Case of Lymphoma with Secondary Involvement of Uterine Cervix Presenting as a Pathological Fracture

    PubMed Central

    Sasikumar, Arun; Joy, Ajith; Pillai, M. R. A.; Thomas, Boben

    2017-01-01

    A 48-year-old female presented with a pathological fracture of the right femur. 99mTc methylene diphosphonate bone scan revealed multiple areas of increased osteoblastic activity consistent with metastatic disease. Serum electrophoresis revealed monoclonal gammopathy. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan revealed metabolically active lesions in bulky uterine cervix and osteolytic skeletal lesions. Unusual pattern of FDG uptake in uterine cervix and osteolytic skeletal lesions warranted a biopsy of the uterine cervix which revealed diffuse large B-cell lymphoma. 18F-FDG PET/CT scan helped in guiding the site of biopsy to reach a final diagnosis in this unusual case of lymphoma with a secondary involvement of uterine cervix presenting as a pathological fracture. PMID:28242988

  9. Paraneoplastic syndrome turned out to be non-Hodgkin's lymphoma on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Sahoo, Manas Kumar; Arunraj, S T; Srivastava, Achal Kumar; Sahoo, Ranjit Kumar; Kumar, Rakesh; Bal, Chandrasekhar

    2016-01-01

    Paraneoplastic neurological syndromes (PNSs) are commonly encountered with underlying malignant pathology. Though anti--neuronal antibodies play a major role in the diagnosis of the underlying malignant pathology but at many times it becomes inconclusive. As early detection of the primary cause and its treatment gives the best result in such situations, there arises an early and accurate diagnostic need. We present a 65--year--old patient presenting with rapidly progressive quadriparesis with both distal and proximal involvement. With all routine work--up tests within normal limits, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) was done which revealed multiple findings that suggested a diagnosis of lymphoma. In our case, PET/CT proved to be an important modality for finding the underlying malignant pathology in a suspected case of PNS.

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

    PubMed

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

    2012-12-01

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

  11. Paraneoplastic syndrome turned out to be non-Hodgkin's lymphoma on 18F-fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Sahoo, Manas Kumar; Arunraj, S. T.; Srivastava, Achal Kumar; Sahoo, Ranjit Kumar; Kumar, Rakesh; Bal, Chandrasekhar

    2016-01-01

    Paraneoplastic neurological syndromes (PNSs) are commonly encountered with underlying malignant pathology. Though anti--neuronal antibodies play a major role in the diagnosis of the underlying malignant pathology but at many times it becomes inconclusive. As early detection of the primary cause and its treatment gives the best result in such situations, there arises an early and accurate diagnostic need. We present a 65--year--old patient presenting with rapidly progressive quadriparesis with both distal and proximal involvement. With all routine work--up tests within normal limits, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) was done which revealed multiple findings that suggested a diagnosis of lymphoma. In our case, PET/CT proved to be an important modality for finding the underlying malignant pathology in a suspected case of PNS. PMID:27833317

  12. 18F-fluorodeoxyglucose Positron Emission Tomography in Kaposi Sarcoma Herpesvirus–Associated Multicentric Castleman Disease: Correlation With Activity, Severity, Inflammatory and Virologic Parameters

    PubMed Central

    Polizzotto, Mark N.; Millo, Corina; Uldrick, Thomas S.; Aleman, Karen; Whatley, Millie; Wyvill, Kathleen M.; O'Mahony, Deirdre; Marshall, Vickie; Whitby, Denise; Maass-Moreno, Roberto; Steinberg, Seth M.; Little, Richard F.; Yarchoan, Robert

    2015-01-01

    Background. Kaposi sarcoma herpesvirus (KSHV)-associated multicentric Castleman disease (MCD) is a lymphoproliferative inflammatory disorder commonly associated with human immunodeficiency virus (HIV). Its presentation may be difficult to distinguish from HIV and its complications, including lymphoma. Novel imaging strategies could address these problems. Methods. We prospectively characterized 18F-fluorodeoxyglucose positron emission tomography (PET) findings in 27 patients with KSHV-MCD. Patients were imaged with disease activity and at remission with scans evaluated blind to clinical status. Symptoms, C-reactive protein level, and HIV and KSHV loads were assessed in relation to imaging findings. Results. KSHV-MCD activity was associated with hypermetabolic symmetric lymphadenopathy (median maximal standardized uptake value [SUVmax], 6.0; range, 2.0–8.0) and splenomegaly (3.4; 1.2–11.0), with increased metabolism also noted in the marrow (2.1; range, 1.0–3.5) and salivary glands (3.0; range, 2.0–6.0). The 18F-fluorodeoxyglucose PET abnormalities improved at remission, with significant SUVmax decreases in the lymph nodes (P = .004), spleen (P = .008), marrow (P = .004), and salivary glands (P = .004). Nodal SUVmax correlated with symptom severity (P = .005), C-reactive protein level (R = 0.62; P = .004), and KSHV load (R = 0.54; P = .02) but not HIV load (P = .52). Conclusions. KSHV-MCD activity is associated with 18F-FDG PET abnormalities of the lymph nodes, spleen, marrow, and salivary glands. These findings have clinical implications for the diagnosis and monitoring of KSHV-MCD and shed light on its pathobiologic mechanism. PMID:25828248

  13. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging in a Patient with HIV (-) Kaposi Sarcoma

    PubMed Central

    Cengiz, Arzu; Şavk, Ekin; Tataroğlu, Canten; Yürekli, Yakup

    2016-01-01

    Kaposi sarcoma (KS) is a vascular neoplasm that often manifests with multiple vascular nodules on the skin and other organs. Various imaging modalities can be used to display disease extent. Herein we present a 65-year-old female patient with human immunodeficiency virus negative KS along with her whole-body positron emission tomography/computed tomography imaging findings. PMID:27751977

  14. Diffuse skeletal muscles uptake of [18F] fluorodeoxyglucose on positron emission tomography in primary muscle peripheral T-cell lymphoma.

    PubMed

    Tanaka, Yuji; Hayashi, Yuichi; Kato, Jun'ichi; Yamada, Megumi; Koumura, Akihiro; Sakurai, Takeo; Kimura, Akio; Hozumi, Isao; Hatano, Yuichiro; Hirose, Yoshinobu; Takami, Tsuyoshi; Nakamura, Hiroshi; Kasahara, Senji; Tsurumi, Hisashi; Moriwaki, Hisataka; Inuzuka, Takashi

    2011-01-01

    A 40-year-old man presented with weakness of neck extensor muscles. Cervical magnetic resonance imaging showed high-intensity areas in muscles of the left lateral cervical region on T2-weighted images. Fluorodeoxyglucose-positron emission tomography scan demonstrated striking fluorodeoxyglucose uptake by multiple skeletal muscles of the neck, chest, and abdominal region. Muscle biopsy demonstrated peripheral T-cell lymphoma, unspecified. The diagnosis was primary skeletal muscle peripheral T-cell lymphoma. Primary skeletal muscle non-Hodgkin's lymphoma of T-cell immunophenotype is extremely rare and fluorodeoxyglucose-positron emission tomography demonstrated striking fluorodeoxyglucose uptake in multiple skeletal muscles and served as a quite useful modality for the diagnosis of this patient.

  15. Response to intra-arterial oncolytic virotherapy with the herpes virus NV1020 evaluated by [18F]fluorodeoxyglucose positron emission tomography and computed tomography.

    PubMed

    Sze, Daniel Y; Iagaru, Andrei H; Gambhir, Sanjiv S; De Haan, Hans A; Reid, Tony R

    2012-01-01

    Oncolytic virotherapy poses unique challenges to the evaluation of tumor response. We hypothesized that the addition of [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) to standard computed tomography (CT) evaluation would improve diagnostic and prognostic power of the measurement of tumor response to oncolytic virotherapy. A phase I/II trial was conducted to investigate treatment of hepatic metastases from colorectal carcinoma using intra-arterial administration of the oncolytic herpes virus NV1020. Both contrast-enhanced CT and FDG PET were obtained on each patient at each time point. Quantitative FDG PET and CT responses were correlated with each other and with clinical outcome metrics. A majority of patients showed initial post-viral infusion increases in tumor size (69%) or in standardized uptake value (SUV) (80%) large enough to qualify as progressive disease. Most showed subsequent decreases in tumor size (64%) or SUV (83%) enough to be reclassified as partial response or stable disease. Late PET and CT imaging results correlated well with each other and with clinical outcomes, but results from early in the treatment scheme did not correlate with each other, with later results, or with clinical outcomes. The addition of FDG PET to the evaluation of tumor response to the oncolytic virus NV1020 did not provide useful diagnostic or prognostic data. More sophisticated molecular imaging will need to be developed to monitor the effects of this novel class of antineoplastic agents.

  16. Impact of {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography Before and After Definitive Radiation Therapy in Patients With Apparently Solitary Plasmacytoma

    SciTech Connect

    Kim, Paul J.; Hicks, Rodney J.; Wirth, Andrew; Ryan, Gail; Seymour, John F.; Prince, H. Miles

    2009-07-01

    Purpose: To evaluate the impact of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) on management of patients with apparently isolated plasmacytoma. Methods and Materials: Twenty-one patients with apparently solitary plasmacytoma who underwent FDG-PET for staging or restaging were identified from a central PET database. They were either candidates for or had received definitive radiation therapy (RT). Results: Seventeen patients had initial staging scans for bone (n = 11) or soft tissue (n = 6) plasmacytomas, and 11 had PET scans after RT. Only 1 of 14 known untreated sites of plasmacytoma was not identified on staging PET (lesion sensitivity = 93%). Three plasmacytomas were excised before PET. Staging PET influenced management in 6 of 17 patients (35%) by showing multiple myeloma (n = 1), discouraging RT after complete resection (n = 1), excluding plasmacytoma at a second site (n = 1), by increasing RT fields (n = 2), or by suggesting sarcoidosis (n = 1). Fifteen of 17 patients with initial staging PET scans received definitive RT. Restaging PET scans after RT showed complete metabolic response in 8 of 11 cases and progressive disease in 2. Two patients with either no response or partial metabolic response had late responses. Staging sestamibi and PET scans were concordant in five of six occasions (one sestamibi scan was false negative). Conclusions: FDG-PET has value for staging and RT planning in plasmacytoma and potentially could have a role in response-assessment after RT. Slow resolution of FDG uptake posttreatment does not necessarily imply an adverse prognosis.

  17. 18F-fluorodeoxyglucose positron emission tomography/computed tomography for primary thyroid langerhans histiocytosis: A case report and literature review

    PubMed Central

    Long, Qi; Shaoyan, Wang; Hui, Wang

    2015-01-01

    Langerhans cell histiocytosis (LCH) is a rare clonal proliferative disease, with an incidence rate of 4.0–5.4/1 million individuals. LCH encompasses a spectrum of disorders with diverse clinical presentations ranging from a single organ to multiple organ involvement. LCH rarely involves the thyroid gland. We presented a case with LCH of thyroid gland. The patient had painless progressive neck enlargement and then diabetes insipidus. Ultrasonic scan and magnetic resonance imaging scan revealed nodular goiter and pituitary stalk enlargement, respectively. Histopathological analysis revealed features of histiocytoid cells. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) was performed in order to rule out the presence of whole body infiltration. 18F-FDG PET/CT also demonstrated increased uptake in the thickening pituitary stalk and maxillofacial skin lesion, in addition to the bilateral thyroid nodules, CT showed the left lung nodule and the skull destruction without 18F-FDG uptake. This report emphasizes the role of 18F-FDG PET/CT in multiple organs involvement of patients with LCH. PMID:26430317

  18. Prognostic value of metabolic parameters on preoperative 18F-Fluorodeoxyglucose positron emission tomography/computed tomography in patients with stage III gastric cancer

    PubMed Central

    Na, Sae Jung; O, Joo Hyun; Park, Jae Myung; Lee, Han Hee; Lee, Sung Hak; Song, Kyo Young; Choi, Myung-Gyu; Park, Cho Hyun

    2016-01-01

    This study investigated the prognostic value of metabolic parameters determined by 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with stage III gastric cancer. Patients with pre-operative PET/CT and confirmed stage III after curative surgical resection were retrospectively enrolled. Parameters evaluated from pre-operative PET/CTwere maximum standardized uptake value (SUVmax) and peak SUV (SUVpeak) of primary tumor, SUVmax or SUVpeak of tumor to liver ratio (TLRmax and TLRpeak). Volumetric parameters, metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were also evaluated. These PET/CT parameters were compared with the overall survival (OS) and recurrence-free survival (RFS). From total of 133 consecutive patients, tumor recurrence was found in 54 patients (40.6%) and 53 died during the follow-up period (median, 43 mo; range 5-62). In univariate analysis, SUVmax, SUVpeak, TLRmax and TLRpeak were significantly associated with the OS and RFS. In multivariate analysis, high TLRmax and TLRpeak were significantly unfavorable prognostic factors for RFS (both P<0.05) even after adjusting for age, depth of tumor invasion, lymph node metastasis, and chemotherapy. MTV and TLG showed no statistically significant correlation with outcome. In conclusion, glucose metabolism of primary tumor measured by pre-operative PET/CT provides prognostic information, especially for recurrence, in stage III gastric cancer. PMID:27564108

  19. Detection of bone marrow involvement in newly diagnosed post-transplant lymphoproliferative disorder: (18)F-fluorodeoxyglucose positron emission tomography/computed tomography versus bone marrow biopsy.

    PubMed

    Gheysens, Olivier; Thielemans, Sanne; Morscio, Julie; Boeckx, Nancy; Goffin, Karolien E; Deroose, Christophe M; Sagaert, Xavier; Wlodarska, Iwona; Verhoef, Gregor; Dierickx, Daan; Tousseyn, Thomas

    2016-10-01

    Detecting bone marrow involvement (BMI) in lymphoma is important as it adversely affects stage. Bone marrow biopsy (BMB) remains the standard to detect BMI but is prone to sampling error. We retrospectively investigated whether (18)F-fluorodeoxyglucose positron emission tomography with computed tomography ((18)F-FDG-PET/CT) could identify BMI in patients with post-transplant lymphoproliferative disorder (PTLD) with sufficient accuracy in comparison with staging BMB. Twenty-five patients diagnosed with PTLD who underwent (18)F-FDG-PET/CT and BMB within one month were evaluated. Based on our criteria, six patients (24%) were considered positive for BMI on (18)F-FDG-PET/CT compared to one by BMB. Although we cannot completely exclude false positive results on (18)F-FDG-PET/CT, our data indicate a significantly higher sensitivity of (18)F-FDG-PET/CT compared to BMB (100% vs 17%) but similar specificity. These data confirm the high diagnostic performance of (18)F-FDG-PET/CT for detecting BMI, but prospective studies are needed to determine whether (18)F-FDG-PET/CT could indeed replace staging BMB in PTLD.

  20. Whole-body 18F-fluorodeoxyglucose positron emission tomography/computed tomography images before and after chemotherapy for Kaposi sarcoma and highly active antiretrovirus therapy.

    PubMed

    Morooka, Miyako; Ito, Kimiteru; Kubota, Kazuo; Minamimoto, Ryogo; Shida, Yoshitaka; Hasuo, Kanehiro; Ito, Tateki; Tasato, Daisuke; Honda, Haruhito; Teruya, Katsuji; Kikuchi, Yoshimi; Ohtomo, Kuni

    2010-12-01

    Kaposi sarcoma is an acquired immunodeficiency syndrome-related disease that mainly involves the skin, gastrointestinal gut, and lungs. Whole-body 18F-fluorodeoxyglucose-positron emission tomography and computed tomography (FDG-PET/CT) scanning is useful for simultaneous detection of multiple lesions of Kaposi sarcoma. We present a 67-year-old man with a history of infection with human immunodeficiency virus who presented with numerous cutaneous lesions. FDG-PET/CT images showed lesions in the skin, lung, and lymph nodes. The gastrointestinal lesions were detected using gastric fiberscopy (GF) and colon fiberscopy (CF). After Kaposi sarcoma therapy, the uptake in the lesions of the skin, lung, and lymph nodes decreased, but new lesions were detected in the pancreas and lumbar spine. He had pancreatitis and Candida spondilitis. Whole-body FDG-PET/CT is useful for detecting lesions and determining the extension to which the disease has spread, adding the gastrointestinal lesions by GF and CF. After therapy, FDG-PET/CT can be used to demonstrate which lesions remain active and to determine the overall response to treatment. In this case, we show how useful FDG-PET/CT is and how difficult it is to treat Kaposi sarcoma.

  1. Quantification of the activity of tritium produced during the routine synthesis of (18)F fluorodeoxyglucose for positron emission tomography.

    PubMed

    Marshall, C; Talboys, M A; Bukhari, S; Evans, W D

    2014-06-01

    Gamma emitting radioactive by-products generated during the cyclotron irradiation of (18)O labelled water by protons to produce (18)FDG (fluorodeoxyglucose) for positron emission tomography are well characterised. However, the production of tritium ((3)H) through the (18)O(p,t)(16)O nuclear reaction has not been investigated in detail. The aim of this study was to measure tritium activity produced during a large number of (18)FDG production runs in order to obtain a better perspective on its impact on radioactive waste management, particularly as regards storage and disposal. Tritium was assayed by liquid scintillation counting in recovered (18)O water from 24 separate production runs. The mean (SD) values of activity and activity concentration were 170 (20) kBq and 81 (8) kBq ml(-1) respectively. Both quantities were positively correlated with the activity of (18)F. Tritium was detected in much lower concentration in water used to rinse the target vessel. The activity of tritium is such that it is exempt from regulatory control and may be combined with bulk non-active waste for disposal as Very Low Level Waste. However, variations in the irradiation conditions or the procedures for the collection of recovered water might result in its classification as Low Level Waste, necessitating a more complex disposal regime.

  2. {sup 18}-F-Fluorodeoxyglucose-Positron Emission Tomography Evaluation of Early Metabolic Response During Radiation Therapy for Cervical Cancer

    SciTech Connect

    Schwarz, Julie K.; Lin, Lillie L.; Siegel, Barry A.; Miller, Tom R.; Grigsby, Perry W.

    2008-12-01

    Purpose: To document changes in cervical tumor {sup 18}-F-fluorodeoxyglocose (FDG) uptake during radiation therapy and to correlate those changes with post-treatment tumor response and survival outcome. Methods and Materials: A total of 36 patients with Stage Ib1 to IIIb cervical cancer were enrolled in an institutional protocol examining the use of fluorodeoxyglucose-positron emission tomography (FDG-PET) for brachytherapy treatment planning. As part of this study, FDG-PET or PET/computed tomograpy (CT) images were obtained before, during, and after the completion of radiation therapy. Tumor metabolic responses were assessed qualitatively and semi-quantitatively by measurement of the maximal standardized uptake value (SUV{sub max}). Results: Post-treatment FDG-PET images were obtained for 36 patients in this study. Of the patients, 29 patients had a complete metabolic response on the post-treatment PET, 4 had a partial metabolic response, and 3 had new sites of FDG uptake. Six patients had a complete metabolic response observed during radiation therapy, 26 had a partial metabolic response and 4 had stable or increased tumor metabolic activity. For patients with complete metabolic response during radiation therapy, median time to complete response was 29.5 days (range, 18-43 days). The mean cervical tumor SUV{sub max} decreased from 11.2 (SD, 6.3; range, 2.1-38.0) pretreatment to 2.4 (SD, 2.7; range, 0-8.8) mid treatment, and 0.5 (SD, 1.7; range, 0-8.3) post-treatment. Conclusions: During radiation therapy for cervical cancer, FDG-PET can be used to monitor treatment response. Complete metabolic response during radiation therapy was observed for a subset of patients. Recommendations regarding the optimal timing of FDG-PET during treatment for cervical cancer will require further systematic study.

  3. 18F-fluorodeoxyglucose and 18F-flumazenil positron emission tomography in patients with refractory epilepsy

    PubMed Central

    Topakian, Raffi; Pichler, Robert

    2016-01-01

    Abstract Background Epilepsy is a neurological disorder characterized by epileptic seizures as a result of excessive neuronal activity in the brain. Approximately 65 million people worldwide suffer from epilepsy; 20–40% of them are refractory to medication therapy. Early detection of disease is crucial in the management of patients with epilepsy. Correct localization of the ictal onset zone is associated with a better surgical outcome. The modern non-invasive techniques used for structural-functional localization of the seizure focus includes electroencephalography (EEG) monitoring, magnetic resonance imaging (MRI), single photon emission tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT). PET/CT can predict surgical outcome in patients with refractory epilepsy. The aim of the article is to review the current role of routinely used tracer 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) as well as non routinely used 18F-Flumazenil (18F-FMZ) tracers PET/CT in patients with refractory epilepsy. Conclusions Functional information delivered by PET and the morphologic information delivered by CT or MRI are essential in presurgical evaluation of epilepsy. Nowadays 18F-FDG PET/CT is a routinely performed imaging modality in localization of the ictal onset zone in patients with refractory epilepsy who are unresponsive to medication therapy. Unfortunately, 18F-FDG is not an ideal PET tracer regarding the management of patients with epilepsy: areas of glucose hypometabolism do not correlate precisely with the proven degree of change within hippocampal sclerosis, as observed by histopathology or MRI. Benzodiazepine-receptor imaging is a promising alternative in nuclear medicine imaging of epileptogenic focus. The use of 11C-FMZ in clinical practice has been limited by its short half-life and necessitating an on-site cyclotron for production. Therefore, 18F-FMZ might be established as one of the tracers of choice for patients

  4. Thoracic [18F]fluorodeoxyglucose uptake measured by positron emission tomography/computed tomography in pulmonary hypertension.

    PubMed

    Frille, Armin; Steinhoff, Karen Geva; Hesse, Swen; Grachtrup, Sabine; Wald, Alexandra; Wirtz, Hubert; Sabri, Osama; Seyfarth, Hans-Juergen

    2016-06-01

    Positron emission tomography (PET) visualizes increased cellular [F]fluorodeoxyglucose ([F]FDG) uptake. Pulmonary hypertension (PH) is conceived of a proliferative disease of the lung vessels. Increased glucose uptake can be quantified as pulmonary [F]FDG uptake via PET imaging. Because the angioproliferative mechanisms in PH are still in need of further description, the aim of the present study was to investigate whether [F]FDG PET/CT imaging can elucidate these pathophysiologic mechanisms in different etiologies of PH.Patients (n = 109) with end-stage pulmonary disease being evaluated for lung transplant were included in this observational study. Mean standardized uptake value (SUVmean) of predefined regions of interest in lung parenchyma (LP), left (LV), and right ventricle (RV) of the heart, and SUVmax in pulmonary artery (PA) were determined and normalized to liver uptake. These SUV ratios (SUVRs) were compared with results from right heart catheterization (mean pulmonary artery pressure [mPAP], pulmonary vascular resistance [PVR]), and serum N-terminal pro-brain natriuretic peptide. Group comparisons were performed and Pearson correlation coefficients (r) were calculated.The [F]FDG uptake ratios in LP, RV, RV/LV, and PA, but not in LV, were found to be significantly higher in both patients with mPAP ≥25 mm Hg (P = 0.013, P = 0.006, P = 0.049, P = 0.002, P = 0.68, respectively) and with PVR ≥480 dyn·s/cm (P < 0.001, P = 0.045, P < 0.001, P < 0.001, P = 0.26, respectively). The [F]FDG uptake in these regions positively correlated also with mPAP, PVR, and N-terminal pro-brain natriuretic peptide. The SUVR of PA positively correlated with the SUVR of LP and RV (r = 0.55, r = 0.42, respectively).Pulmonary and cardiac [F]FDG uptake in PET imaging positively correlated with the presence and severity of PH in patients with end-stage pulmonary disease. Increased glucose metabolism in the central PAs seems to

  5. 18F-fluorodeoxyglucose positron emission tomography in elderly patients with an elevated erythrocyte sedimentation rate of unknown origin.

    PubMed

    Lensen, Karel-Jan D F; Voskuyl, Alexandre E; van der Laken, Conny J; Comans, Emile F I; van Schaardenburg, Dirkjan; Arntzenius, Alex B; Zwijnenburg, Ton; Stam, Frank; Gompelman, Michelle; Zant, Friso M V D; van Paassen, Anneke Q A; Voerman, Bert J; Smit, Frits; Anten, Sander; Siegert, Carl E; Binnerts, Arjen; Smulders, Yvo M

    2013-01-01

    Patients with an elevated erythrocyte sedimentation rate (ESR) and non-specific symptoms often pose a diagnostic dilemma. PET/CT visualises infection, inflammation and malignancy, all of which may cause elevated ESR. The objective of this study was to determine the contribution of 18F-fluorodeoxglucose positron emission tomography (PET/CT) in the diagnostic work-up of referred patients with an elevated ESR, in whom initial routine evaluation did not reveal a diagnosis. We conducted a combined retrospective (A) and prospective (B) study in elderly (>50 years) patients with a significantly elevated ESR of ≥ 50 mm/h and non-specific complaints. In study A, 30 patients were included. Malignancy (8 patients), auto-inflammatory disease (8 patients, including 5 with large-vessel vasculitis) and infection (3 patients) were suggested by PET/CT. Two scans showed non-specific abnormalities and 9 scans were normal. Of the 21 abnormal PET/CT results, 12 diagnoses were independently confirmed and two alternative diagnosis were made. Two diagnoses were established in patients with a normal scan. In study B, 58 patients in whom a prior protocolised work-up was non-diagnostic, were included. Of these, 25 PET/CT-scans showed suspected auto-inflammatory disease, particularly large-vessel vasculitis (14 cases). Infection and malignancy was suspected in 5 and 3 cases, respectively. Seven scans demonstrated non-specific abnormalities, 20 were normal. Of the 40 abnormal PET/CT results, 22 diagnoses were confirmed, 3 alternative diagnoses were established. Only one diagnosis was established in the 20 patients with a normal scan. In both studies, the final diagnosis was based on histology, clinical follow-up, response to therapy or additional imaging. In conclusion, PET/CT may be of potential value in the diagnostic work-up of patients with elevated ESR if routine evaluation reveals no diagnosis. In particular, large-vessel vasculitis appears to be a common finding. A normal PET/CT scan

  6. Clinical Usefulness of {sup 18}F-Fluorodeoxyglucose-Positron Emission Tomography in Patients With Locally Advanced Pancreatic Cancer Planned to Undergo Concurrent Chemoradiation Therapy

    SciTech Connect

    Chang, Jee Suk; Choi, Seo Hee; Lee, Youngin; Kim, Kyung Hwan; Park, Jeong Youp; Song, Si Young; Cho, Arthur; Yun, Mijin; Lee, Jong Doo; Seong, Jinsil

    2014-09-01

    Purpose: To assess the role of coregistered {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting radiographically occult distant metastasis (DM) at staging in patients with locally advanced pancreatic cancer (LAPC) and to study whether FDG-PET parameters can predict relatively long-term survival in patients who are more likely to benefit from chemoradiation therapy (CRT). Methods and Materials: From our institutional database, we identified 388 LAPC patients with M0 on conventional computed tomography (CT) who were planned to undergo CRT. Coregistered FDG-PET staging was offered to all patients, and follow-up FDG-PET was used at the clinical discretion of the physician. Results: FDG-PET detected unsuspected CT-occult DM in 33% of all 388 patients and allowed them to receive systemic therapy immediately. The remaining 260 patients (PET-M0) underwent CRT selectively as an initial treatment. Early DM arose in 13.1% of 260 patients, and the 1-year estimated locoregional recurrence rate was 5.4%. Median overall survival (OS) and progression-free survival (PFS) were 14.6 and 9.3 months, respectively, at a median follow-up time of 32.3 months (range, 10-99.1 months). Patients with a baseline standardized uptake value (SUV) <3.5 and/or SUV decline ≥60% had significantly better OS and PFS than those having none, even after adjustment for all potential confounding variables (all P<.001). Conclusions: FDG-PET can detect radiographically occult DM at staging in one-third of patients and spare them from the potentially toxic therapy. Additionally, FDG-PET parameters including baseline SUV and SUV changes may serve as useful clinical markers for predicting the prognosis in LAPC patients.

  7. [{sup 18}F]Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (PET/CT) Physiologic Imaging of Choroidal Melanoma: Before and After Ophthalmic Plaque Radiation Therapy

    SciTech Connect

    Finger, Paul T.; Chin, Kimberly J.

    2011-01-01

    Purpose: To evaluate changes in [{sup 18}F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) standardized uptake values (SUV) in uveal melanoma before and after plaque brachytherapy. Methods and Materials: A cohort of 217 patients diagnosed with uveal melanoma and eligible for ophthalmic plaque brachytherapy underwent preoperative PET/CT to evaluate their intraocular tumor and screen for metastasis. Subsequent to undergoing plaque brachytherapy, patients' PET/CT SUV were periodically reevaluated over 42 months. Results: In this series, 37 (17%) choroidal melanoma patients were found to have an SUV of >2.0. Of these, 18 patients were able to undergo interval follow-up PET/CT scanning. There were 3 patients with T2, 11 patients with T3, and 4 patients with T4 melanomas according to 7th edition AJCC-UICC criteria. Mean apical thickness was 8.8 mm (range, 3-12.3 mm), and the largest mean tumor diameter was 15.1 mm (range, 12-19.9 mm). The mean initial SUV was 3.7 (range, 2.1-7.3). Patients were followed for a median 16 months (range, 6-42 months). The median time to a tumor SUV of 0 was 8.0 months (range, 6-18 months). There was one case of one interval increase in SUV that diminished after circumferential laser treatment. Conclusions: Intraocular PET/CT imaging provides a physiological assessment of tumor metabolism that can be used to evaluate changes after treatment. In this study, ophthalmic plaque radiation therapy was associated with extinguished tumor PET/CT SUV over time. PET/CT imaging can be used to assess choroidal melanomas for their response to treatment.

  8. Prognostic value of volumetric metabolic parameters measured by [18F]Fluorodeoxyglucose-positron emission tomography/computed tomography in patients with small cell lung cancer

    PubMed Central

    2014-01-01

    Background We evaluated the prognostic value of volume-based metabolic positron emission tomography (PET) parameters in patients with small cell lung cancer (SCLC) compared with other factors. Methods The subjects were 202 patients with pathologically proven SCLC who underwent pretreatment 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT). Volumetric metabolic parameters of intrathoracic malignant hypermetabolic lesions, including maximum and average standardized uptake value, sum of metabolic tumor volume (MTV), and sum of total lesion glycolysis (TLG) were measured. Results 164 patients had died during follow-up (median 17.4 months) and median overall survival was 14 months. On univariate survival analysis, age, stage, treatment modality, sum of MTV (cutoff = 100 cm3), and sum of TLG (cutoff = 555) were significant predictors of survival. There was a very high correlation between the sum of MTV and the sum of TLG (r = 0.963, P < 0.001). On multivariate survival analysis, age (HR = 1.04, P < 0.001), stage (HR = 2.442, P < 0.001), and sum of MTV (HR = 1.662, P = 0.002) were independent prognostic factors. On subgroup analysis based on limited disease (LD) and extensive disease (ED), sum of MTV and sum of TLG were significant prognostic factors only in LD. Conclusion Both sum of MTV and sum of TLG of intrathoracic malignant hypermetabolic lesions are important independent prognostic factors for survival in patients with SCLC, in addition to age and clinical stage. However, it may be more useful in limited disease rather than in extensive disease. PMID:25609313

  9. Impact of 18F-fluorodeoxyglucose positron emission tomography in the staging and treatment response assessment of extra-pulmonary small-cell cancer.

    PubMed

    Gregory, D L; Brennan, S M; Stillie, A; Herschtal, A; Hicks, R J; MacManus, M P; Ball, D L

    2010-04-01

    The aim of this study was to retrospectively evaluate the value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in extrapulmonary small-cell cancer (EPSCC). Patients with EPSCC who underwent PET for staging or response assessment between 1996 and 2007 were identified from a database. Patient records were reviewed. PET-based, and conventional staging and restaging results were compared. The binary staging classification of limited disease (LD) versus extensive disease (ED) was used. Patients with LD had tumours that could be encompassed within a tolerable radiation therapy (RT) volume. Of 33 eligible patients, 12 had staging PET scans, 11 had restaging scans and 10 had both. All known gross disease sites were FDG-avid. PET and conventional stage groupings were concordant in 21 of 22 cases. One patient was appropriately upstaged from LD to ED by PET. PET detected additional disease sites, without causing upstaging in three further patients. Restaging PET scans identified previously unrecognised persistent or progressive disease in 4 of 21 cases. In four further cases, persistent FDG uptake after treatment was either false positive (n = 2) or of uncertain (n = 2) aetiology. PPV was 100% for staging and 82% for restaging. In 8 of 43 imaging episodes (19%), PET appropriately influenced management in five cases by changing treatment intent from radical to palliative, and in three cases by altering the RT volume. PET has incremental value compared to conventional imaging for staging EPSCC, and may also be useful for restaging after therapy. PET influenced patient management in 19% of 43 imaging episodes.

  10. Impact of Pretreatment Combined {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Staging on Radiation Therapy Treatment Decisions in Locally Advanced Breast Cancer

    SciTech Connect

    Ng, Sweet Ping; David, Steven; Alamgeer, Muhammad; Ganju, Vinod

    2015-09-01

    Purpose: To assess the diagnostic performance of pretreatment {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) and its impact on radiation therapy treatment decisions in patients with locally advanced breast cancer (LABC). Methods and Materials: Patients with LABC with Eastern Cooperative Oncology Group performance status <2 and no contraindication to neoadjuvant chemotherapy, surgery, and adjuvant radiation therapy were enrolled on a prospective trial. All patients had pretreatment conventional imaging (CI) performed, including bilateral breast mammography and ultrasound, bone scan, and CT chest, abdomen, and pelvis scans performed. Informed consent was obtained before enrolment. Pretreatment whole-body {sup 18}F-FDG PET/CT scans were performed on all patients, and results were compared with CI findings. Results: A total of 154 patients with LABC with no clinical or radiologic evidence of distant metastases on CI were enrolled. Median age was 49 years (range, 26-70 years). Imaging with PET/CT detected distant metastatic disease and/or locoregional disease not visualized on CI in 32 patients (20.8%). Distant metastatic disease was detected in 17 patients (11.0%): 6 had bony metastases, 5 had intrathoracic metastases (pulmonary/mediastinal), 2 had distant nodal metastases, 2 had liver metastases, 1 had pulmonary and bony metastases, and 1 had mediastinal and distant nodal metastases. Of the remaining 139 patients, nodal disease outside conventional radiation therapy fields was detected on PET/CT in 15 patients (10.8%), with involvement of ipsilateral internal mammary nodes in 13 and ipsilateral level 5 cervical nodes in 2. Conclusions: Imaging with PET/CT provides superior diagnostic and staging information in patients with LABC compared with CI, which has significant therapeutic implications with respect to radiation therapy management. Imaging with PET/CT should be considered in all patients undergoing primary

  11. Clinical Significance of Postradiotherapy [{sup 18}F]-Fluorodeoxyglucose Positron Emission Tomography Imaging in Management of Head-and-Neck Cancer-A Long-Term Outcome Report

    SciTech Connect

    Yao Min Smith, Russell B.; Hoffman, Henry T.; Funk, Gerry F.; Lu Minggen; Menda, Yusuf; Graham, Michael M.; Buatti, John M.

    2009-05-01

    Purpose: To determine the accuracy and prognostic significance of post-treatment [{sup 18}F]-fluorodeoxyglucose positron emission tomography (FDG-PET) in head-and-neck squamous cell carcinoma after radiotherapy (RT). Methods and Materials: This was a retrospective study of 188 patients with head-and-neck squamous cell carcinoma who had undergone FDG-PET within 12 months after completing RT. All living patients had {>=}1 year of follow-up after FDG-PET. All patients had undergone intensity-modulated RT, 128 with definitive and 60 with postoperative intensity-modulated RT. Results: For all patients, the median follow-up after RT completion was 32.6 months and after FDG-PET was 29.2 months. For the neck, 171 patients had negative FDG-PET findings. Of these results, two were falsely negative. Seventeen patients had positive FDG-PET findings, of which 12 were true-positive findings. The sensitivity, specificity, positive predictive value, and negative predictive value for FDG-PET in the assessment of the treatment response in the neck was 86%, 97%, 71%, and 99%, respectively. For the primary site, 151 patients had negative FDG-PET findings, of which two were falsely negative. Thirty-seven patients had positive FDG-PET findings, of which 12 were true-positive findings. The sensitivity, specificity, positive predictive value, and negative predictive value for FDG-PET in the assessment of the treatment response in the primary site was 86%, 86%, 32.4%, and 98.7%, respectively. Patients with positive post-RT PET findings had significantly worse 3-year overall survival and disease-free survival. Conclusion: The results of our study have shown that the findings of post-RT FDG-PET have a high negative predictive value and are a significant prognostic factor. It can provide guidance for the management of head-and-neck cancer after definitive treatment.

  12. Clinical importance of [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography in the management of patients with bronchoalveolar carcinoma: Role in the detection of recurrence.

    PubMed

    Skoura, Evangelia; Datseris, Ioannis E; Exarhos, Dimitrios; Chatziioannou, Sophia; Oikonomopoulos, Georgios; Samartzis, Alexandros; Giannopoulou, Chariklia; Syrigos, Konstantinos N

    2013-05-01

    [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been reported to have a low sensitivity in the initial diagnosis of bronchoalveolar carcinoma (BAC) due to BAC's low metabolic activity. The aim of this study was to assess the value of [(18)F]FDG-PET/CT in the detection of BAC recurrence. Between February 2007 and September 2011, the [(18)F]FDG-PET/CT scans that were performed on patients with known, histologically proven BAC were studied. A total of 24 [(18)F]FDG-PET/CT scans were performed in 22 patients, including 16 males and 6 females, with a mean age of 65±9 years. Among the scans, 15 were performed to assess for possible recurrence with equivocal findings in conventional imaging methods and 9 for restaging post-therapy. In all cases conventional imaging studies (CT and MRI) were performed 5-30 days prior to PET/CT. Among the 24 [(18)F]FDG-PET/CT scans, 18 were positive and 6 negative. Among the 15 [(18)F]FDG-PET/CT scans performed for suspected recurrence, 34 lesions were detected and the mean maximum standardized uptake value (SUVmax) was 6.8±3.26. In nine scans, upstaging was observed, while two were in agreement with the findings of the conventional modalities. A greater number of lesions were detected in two scans and fewer lesions were detected in one, with no change in staging. Only one scan was negative. By contrast, in patients examined for restaging, there were only five lesions with a mean SUVmax of 4.86±3.18. Agreement between the findings of [(18)F]FDG-PET/CT and the conventional modalities was observed in 8 out of 9 cases. Although [(18)F]FDG-PET/CT has been reported to have a low sensitivity in the initial diagnosis of BAC, the present results indicate that when there is recurrence, the lesions become [(18)F]FDG avid. [(18)F]FDG-PET/CT may provide further information in patients evaluated for recurrence and thus improve patient management.

  13. Volume-Based Parameters of {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Improve Disease Recurrence Prediction in Postmastectomy Breast Cancer Patients With 1 to 3 Positive Axillary Lymph Nodes

    SciTech Connect

    Nakajima, Naomi; Kataoka, Masaaki; Sugawara, Yoshifumi; Ochi, Takashi; Kiyoto, Sachiko; Ohsumi, Shozo; Mochizuki, Teruhito

    2013-11-15

    Purpose: To determine whether volume-based parameters on pretreatment {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography in breast cancer patients treated with mastectomy without adjuvant radiation therapy are predictive of recurrence. Methods and Materials: We retrospectively analyzed 93 patients with 1 to 3 positive axillary nodes after surgery, who were studied with {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography for initial staging. We evaluated the relationship between positron emission tomography parameters, including the maximum standardized uptake value, metabolic tumor volume (MTV), and total lesion glycolysis (TLG), and clinical outcomes. Results: The median follow-up duration was 45 months. Recurrence was observed in 11 patients. Metabolic tumor volume and TLG were significantly related to tumor size, number of involved nodes, nodal ratio, nuclear grade, estrogen receptor (ER) status, and triple negativity (TN) (all P values were <.05). In receiver operating characteristic curve analysis, MTV and TLG showed better predictive performance than tumor size, ER status, or TN (area under the curve: 0.85, 0.86, 0.79, 0.74, and 0.74, respectively). On multivariate analysis, MTV was an independent prognostic factor of locoregional recurrence-free survival (hazard ratio 34.42, 95% confidence interval 3.94-882.71, P=.0008) and disease-free survival (DFS) (hazard ratio 13.92, 95% confidence interval 2.65-103.78, P=.0018). The 3-year DFS rate was 93.8% for the lower MTV group (<53.1; n=85) and 25.0% for the higher MTV group (≥53.1; n=8; P<.0001, log–rank test). The 3-year DFS rate for patients with both ER-positive status and MTV <53.1 was 98.2%; and for those with ER-negative status and MTV ≥53.1 it was 25.0% (P<.0001). Conclusions: Volume-based parameters improve recurrence prediction in postmastectomy breast cancer patients with 1 to 3 positive nodes. The addition of MTV to ER status or TN has

  14. FDG-PET response-adapted therapy: is 18F-fluorodeoxyglucose positron emission tomography a safe predictor for a change of therapy?

    PubMed

    Hutchings, Martin

    2014-02-01

    Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is the most accurate tool for staging, treatment monitoring, and response evaluation in Hodgkin lymphoma (HL). Early determination of treatment sensitivity by FDG-PET is the best tool to guide individualized, response-adapted treatment. Several ongoing or recently completed trials have investigated the use of FDG-PET/CT for early response-adapted HL therapy. The results are encouraging, but the data are immature, and PET response-adapted HL therapy is discouraged outside the setting of clinical trials. PET/CT looks promising for selection of therapy in relapsed and refractory disease, but the role in this setting is still unclear.

  15. Early evaluation of tumour metabolic response using [18F]fluorodeoxyglucose and positron emission tomography:a pilot study following the phase II chemotherapy schedule for temozolomide in recurrent high-grade gliomas

    PubMed Central

    Brock, C S; Young, H; O'Reilly, S M; Matthews, J; Osman, S; Evans, H; Newlands, E S; Price, P M

    2000-01-01

    Quantitation of metabolic changes in tumours may provide an objective measure of clinical and subclinical response to anticancer therapy. This pilot study assesses the value of quantitation of metabolic rate of glucose (MRGlu) measured in mmol min−1ml−1to assess early subclinical response to therapy in a relatively non-responsive tumour. Nine patients receiving the CRC Phase II study schedule of temozolomide were assessed with [18F]fluorodeoxyglucose ([18F]FDG) dynamic positron emission tomography (PET) scans prior to and 14 days after treatment with temozolomide given as 750–1000 mg m−2over 5 days every 28 days. Tumour MRGlu was calculated and compared with objective response at 8 weeks. Pretreatment MRGlu was higher in responders than non-responders. The responding patient group had a greater than 25% reduction in MRGlu in regions of high focal tumour uptake (HFU). Whole tumour changes in MRGlu did not correlate with response. Percentage change in HFU standardized uptake value (SUV) did discriminate the responding from the non-responding patients, but not as well as with MRGlu. Large differences also occurred in the normal brain SUV following treatment. Thus, MRGlu appeared to be a more sensitive discriminator of response than the simplified static SUV analysis. Changes in MRGlu may reflect the degree of cell kill following chemotherapy and so may provide an objective, quantitative subclinical measure of response to therapy. © 2000 Cancer Research Campaign PMID:10682673

  16. Impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography staging in newly diagnosed classical Hodgkin lymphoma: fewer cases with stage I disease and more with skeletal involvement.

    PubMed

    El-Galaly, Tarec Christoffer; Hutchings, Martin; Mylam, Karen Juul; Brown, Peter de Nully; Bukh, Anne; Johnsen, Hans Erik; Kamper, Peter; Loft, Annika; Iyer, Victor; Gormsen, Lars Christian; Nielsen, Anne Lerberg; Bøgsted, Martin; d'Amore, Francesco

    2014-10-01

    (18)F-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 outcome in PET/CT staged patients. In conclusion, PET/CT led to higher disease stages, and the more frequently diagnosed skeletal lesions may be an adverse prognostic factor.

  17. Use of 18F-Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography to Aid in Diagnosing Intestinal Adenocarcinoma in 2 Rhesus Macaques (Macaca mulatta)

    PubMed Central

    Caporizzo, Debra J; Kwiatkowski, Anna E; Chen, Ming-Kai; Beck, Amanda P; Booth, Carmen J; Zeiss, Caroline; Smith, Peter C; Scholz, Jodi A Carlson; Wilson, Steven R

    2014-01-01

    Two aged female rhesus macaques (Macaca mulatta) presented with weight loss and intermittent inappetence. The signalment and constellation of clinical signs led clinicians to suspect the presence of intestinal adenocarcinoma. Because of each animal's advanced age and inconclusive radiographic findings, a noninvasive diagnostic tool was preferred over exploratory laparotomy to assist in determining a diagnosis. Consequently, 2-[18F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography–CT (FDG-PET–CT) was chosen to aid in confirming a suspicion of gastrointestinal adenocarcinoma in both animals. FDG is a glucose analogue labeled with fluorine-18 and is taken up by highly metabolically active cells, as observed in many cancers. Tomography revealed an annular constriction of the small intestine with focal FDG uptake in one animal, and an FDG avid transmural mass in the ascending colon of the second animal. Necropsy later confirmed both sites to be adenocarcinomas. This report supports the use of FDG-PET–CT as an adjunct to conventional radiography in the diagnosis of intestinal adenocarcinoma in nonhuman primates. PMID:24956213

  18. Use of (18)F-fluorodeoxyglucose positron emission tomography-computed tomography to aid in diagnosing intestinal adenocarcinoma in 2 rhesus macaques (Macaca mulatta).

    PubMed

    Caporizzo, Debra J; Kwiatkowski, Anna E; Chen, Ming-Kai; Beck, Amanda P; Booth, Carmen J; Zeiss, Caroline; Smith, Peter C; Carlson Scholz, Jodi A; Wilson, Steven R

    2014-06-01

    Two aged female rhesus macaques (Macaca mulatta) presented with weight loss and intermittent inappetence. The signalment and constellation of clinical signs led clinicians to suspect the presence of intestinal adenocarcinoma. Because of each animal's advanced age and inconclusive radiographic findings, a noninvasive diagnostic tool was preferred over exploratory laparotomy to assist in determining a diagnosis. Consequently, 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography-CT (FDG-PET-CT) was chosen to aid in confirming a suspicion of gastrointestinal adenocarcinoma in both animals. FDG is a glucose analogue labeled with fluorine-18 and is taken up by highly metabolically active cells, as observed in many cancers. Tomography revealed an annular constriction of the small intestine with focal FDG uptake in one animal, and an FDG avid transmural mass in the ascending colon of the second animal. Necropsy later confirmed both sites to be adenocarcinomas. This report supports the use of FDG-PET-CT as an adjunct to conventional radiography in the diagnosis of intestinal adenocarcinoma in nonhuman primates.

  19. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Accuracy in the Staging of Non-Small Cell Lung Cancer: Review and Cost-Effectiveness

    PubMed Central

    Gómez León, Nieves; Escalona, Sofía; Bandrés, Beatriz; Belda, Cristobal; Callejo, Daniel; Blasco, Juan Antonio

    2014-01-01

    Aim of the performed clinical study was to compare the accuracy and cost-effectiveness of PET/CT in the staging of non-small cell lung cancer (NSCLC). Material and Methods. Cross-sectional and prospective study including 103 patients with histologically confirmed NSCLC. All patients were examined using PET/CT with intravenous contrast medium. Those with disease stage ≤IIB underwent surgery (n = 40). Disease stage was confirmed based on histology results, which were compared with those of PET/CT and positron emission tomography (PET) and computed tomography (CT) separately. 63 patients classified with ≥IIIA disease stage by PET/CT did not undergo surgery. The cost-effectiveness of PET/CT for disease classification was examined using a decision tree analysis. Results. Compared with histology, the accuracy of PET/CT for disease staging has a positive predictive value of 80%, a negative predictive value of 95%, a sensitivity of 94%, and a specificity of 82%. For PET alone, these values are 53%, 66%, 60%, and 50%, whereas for CT alone they are 68%, 86%, 76%, and 72%, respectively. Incremental cost-effectiveness of PET/CT over CT alone was €17,412 quality-adjusted life-year (QALY). Conclusion. In our clinical study, PET/CT using intravenous contrast medium was an accurate and cost-effective method for staging of patients with NSCLC. PMID:25431665

  20. Contrast-Enhanced [{sup 18}F]fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Staging and Radiotherapy Planning in Patients With Anal Cancer

    SciTech Connect

    Bannas, Peter; Weber, Christoph; Adam, Gerhard; Frenzel, Thorsten; Derlin, Thorsten; Mester, Janos; Klutmann, Susanne

    2011-10-01

    Purpose: The practice of surgical staging and treatment of anal cancer has been replaced by noninvasive staging and combined modality therapy. For appropriate patient management, accurate lymph node staging is crucial. The present study evaluated the feasibility and diagnostic accuracy of contrast-enhanced [{sup 18}F]fluoro-2-deoxy-D-glucose ([{sup 18}F]FDG)-positron emission tomography/computed tomography (PET/CT) for staging and radiotherapy planning of anal cancer. Methods and Materials: A total of 22 consecutive patients (median age, 61 years old) with anal cancer underwent complete staging evaluation including physical examination, biopsy of the primary tumor, and contrast-enhanced (ce)-PET/CT. Patients were positioned as they would be for their subsequent radiotherapy. PET and CT images were evaluated independently for detectability and localization of the primary tumor, pelvic and inguinal lymph nodes, and distant metastasis. The stage, determined by CT or PET alone, and the proposed therapy planning were compared with the stage and management determined by ce-PET/CT. Data from ce-PET/CT were used for radiotherapy planning. Results: ce-PET/CT revealed locoregional lymph node metastasis in 11 of 22 patients (50%). After simultaneous reading of PET and CT data sets by experienced observers, 3 patients (14%) were found to have sites of disease not seen on CT that were identified on PET. Two patients had sites of disease not seen on PET that were identified on CT. In summary, 2 patients were upstaged, and 4 patients were downstaged due to ce-PET/CT. However, radiotherapy fields were changed due to the results from ce-PET/CT in 23% of cases compared to CT or PET results alone. Conclusions: ce-PET/CT is superior to PET or CT alone for staging of anal cancer, with significant impact on therapy planning.

  1. A comparison study of 11C-methionine and 18F-fluorodeoxyglucose positron emission tomography-computed tomography scans in evaluation of patients with recurrent brain tumors

    PubMed Central

    Sharma, Rajnish; D’Souza, Maria; Jaimini, Abhinav; Hazari, Puja Panwar; Saw, Sanjeev; Pandey, Santosh; Singh, Dinesh; Solanki, Yachna; Kumar, Nitin; Mishra, Anil K.; Mondal, Anupam

    2016-01-01

    Introduction: 11C-methonine ([11C]-MET) positron emission tomography-computed tomography (PET-CT) is a well-established technique for evaluation of tumor for diagnosis and treatment planning in neurooncology. [11C]-MET reflects amino acid transport and has been shown to be more sensitive than magnetic resonance imaging (MRI) in stereotactic biopsy planning. This study compared fluorodeoxyglucose (FDG) PET-CT and MET PET-CT in the detection of various brain tumors. Materials and Methods: Sixty-four subjects of brain tumor treated by surgery, chemotherapy, and/or radiotherapy were subjected to [18F]-FDG, [11C]-MET, and MRI scan. The lesion was analyzed semiquantitatively using tumor to normal contralateral ratio. The diagnosis was confirmed by surgery, stereotactic biopsy, clinical follow-up, MRI, or CT scans. Results: Tumor recurrence was found in 5 out of 22 patients on [F-18] FDG scan while [11C]-MET was able to detect recurrence in 18 out of 22 patients in low-grade gliomas. Two of these patients were false positive for the presence of recurrence of tumor and later found to be harboring necrosis. Among oligodendroglioma, medulloblastoma and high-grade glioma out of 42 patients 39 were found to be concordant MET and FDG scans. On semiquantitative analysis, mean T/NT ratio was found to be 2.96 ± 0.94 for lesions positive for recurrence of tumors and 1.18 ± 0.74 for lesions negative for recurrence of tumor on [11C]-MET scan. While the ratio for FDG scan on semiquantitative analysis was found to be 2.05 ± 1.04 for lesions positive for recurrence of tumors and 0.52 ± 0.15 for lesions negative for recurrence of tumors. Conclusion: The study highlight that [11C]-MET is superior to [18F]-FDG PET scans to detect recurrence in low-grade glioma. A cut-off value of target to nontarget value of 1.47 is a useful parameter to distinguish benign from malignant lesion on an [11C]-MET Scan. Both [18F]-FDG and [11C]-MET scans were found to be useful in high-grade astrocytoma

  2. Prognostic Significance of Tumor Response as Assessed by Sequential {sup 18}F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography During Concurrent Chemoradiation Therapy for Cervical Cancer

    SciTech Connect

    Oh, Dongryul; Lee, Jeong Eun; Huh, Seung Jae; Park, Won; Nam, Heerim; Choi, Joon Young; Kim, Byung-Tae

    2013-11-01

    Purpose: To investigate the prognostic role of metabolic response by the use of serial sets of positron emission tomography/computed tomography (PET/CT) in patients with cervical cancer who were treated with concurrent chemoradiation therapy (CCRT). Methods and Materials: A total of 60 patients who were treated with CCRT between February 2009 and December 2010 were analyzed. Three sequential PET/CT images were acquired for each patient: pre-CCRT, during-CCRT at 4 weeks of CCRT, and 1 month post-CCRT PET/CT. Metabolic responses were assessed qualitatively. The percentage changes in the maximum values of standardized uptake value (ΔSUV{sub max}%) from the PET/CT images acquired pre-CCRT and during-CCRT were calculated. Receiver operating characteristic (ROC) curve analysis was performed to evaluate whether ΔSUV{sub max}% could predict complete response (CR) on the post-CCRT PET/CT and to identify the best cutoff value. Prognostic factors of progression-free survival (PFS) were analyzed. Results: During-CCRT PET/CT showed that 8 patients (13%) had CR, and the other 52 patients (87%) had partial response (PR). On the post-CCRT PET/CT, 43 patients (73%) had CR, 12 patients (20%) had PR, and 4 patients (7%) had progressive disease. The average SUV{sub max} in primary tumors was 16.3 (range, 6.4-53.0) on the pre-CCRT PET/CT images and 5.3 (range, 0-19.4) on the during-CCRT PET/CT images. According to ROC curve analysis, ΔSUV{sub max}% could predict CR response on post-CCRT PET/CT (P<.001, cutoff value of 59.7%). In all patients, the PFS rate was 71.9% at 2 years. Multivariate analysis showed that ΔSUV{sub max}% ≥60% (P=.045) and CR response on the post-CCRT PET/CT (P=.012) were statistically significant predictors of PFS. Conclusion: Metabolic responses on the during-CCRT images at 4 weeks of treatment and 1-month post-CCRT PET/CT images may predict treatment outcomes in patients with cervical cancer. ΔSUV{sub max}% ≥60% at 4 weeks of CCRT may predict CR response

  3. Preoperative [18F]Fluorodeoxyglucose Positron Emission Tomography Standardized Uptake Value of Neck Lymph Nodes Predicts Neck Cancer Control and Survival Rates in Patients With Oral Cavity Squamous Cell Carcinoma and Pathologically Positive Lymph Nodes

    SciTech Connect

    Liao, C.-T.; Chang, J.T.-C.; Wang, H.-M.; Ng, S.-H.; Hsueh, C.; Lee, L.-Y.; Lin, C.-H.; Chen, I-H.; Huang, S.-F.

    2009-07-15

    Purpose: Survival in oral cavity squamous cell carcinoma (OSCC) depends heavily on locoregional control. In this prospective study, we sought to investigate whether preoperative maximum standardized uptake value of the neck lymph nodes (SUVnodal-max) may predict prognosis in OSCC patients. Methods and Materials: A total of 120 OSCC patients with pathologically positive lymph nodes were investigated. All subjects underwent a [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) scan within 2 weeks before radical surgery and neck dissection. All patients were followed up for at least 24 months after surgery or until death. Postoperative adjuvant therapy was performed in the presence of pathologic risk factors. Optimal cutoff values of SUVnodal-max were chosen based on 5-year disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). Independent prognosticators were identified by Cox regression analysis. Results: The median follow-up for surviving patients was 41 months. The optimal cutoff value for SUVnodal-max was 5.7. Multivariate analyses identified the following independent predictors of poor outcome: SUVnodal-max {>=}5.7 for the 5-year neck cancer control rate, distant metastatic rate, DFS, DSS, and extracapsular spread (ECS) for the 5-year DSS and OS. Among ECS patients, the presence of a SUVnodal-max {>=}5.7 identified patients with the worst prognosis. Conclusion: A SUVnodal-max of 5.7, either alone or in combination with ECS, is an independent prognosticator for 5-year neck cancer control and survival rates in OSCC patients with pathologically positive lymph nodes.

  4. 18F-fluorodeoxyglucose Positron Emisson Tomography/Computed Tomography Guided Conformal Brachytherapy for Cervical Cancer

    SciTech Connect

    Nam, Heerim; Huh, Seung Jae; Ju, Sang Gyu; Park, Won; Lee, Jeong Eun; Choi, Joon Young; Kim, Byung-Tae; Kim, Chan Kyo; Park, Byung Kwan

    2012-09-01

    Purpose: To evaluate the feasibility of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT)-guided conformal brachytherapy treatment planning in patients with cervical cancer. Methods and Materials: Pretreatment FDG-PET/CT was performed for 12 patients with cervical cancer. Brachytherapy simulation was performed after an external-beam radiation therapy median dose of 4140 cGy. Patients underwent FDG-PET/CT scans with placement of tandem and ovoid applicators. The gross tumor volume (GTV) was determined by adjusting the window and level to a reasonable value and outlining the edge of the enhancing area, which was done in consultation with a nuclear medicine physician. A standardized uptake value profile of the tumor margin was taken for each patient relative to the maximum uptake value of each tumor and analyzed. The plan was designed to deliver 400 cGy to point A (point A plan) or to cover the clinical target volume (CTV) (PET/CT plan). Results: The median dose that encompassed 95% of the target volume (D95) of the CTV was 323.0 cGy for the point A plan vs 399.0 cGy for the PET/CT plan (P=.001). The maximum standardized uptake values (SUV{sub max}) of the tumors were reduced by a median of 57% (range, 13%-80%). All but 1 patient presented with discernable residual uptake within the tumors. The median value of the thresholds of the tumors contoured by simple visual analysis was 41% (range, 23%-71%). Conclusions: In this study, the PET/CT plan was better than the conventional point A plan in terms of target coverage without increasing the dose to the normal tissue, making optimized 3-dimensional brachytherapy treatment planning possible. In comparison with the previously reported study with PET or CT alone, we found that visual target localization was facilitated by PET fusion on indeterminate CT masses. Further studies are needed to characterize the metabolic activity detected during radiation therapy for more reliable targeting.

  5. Increased (18)F-fluorodeoxyglucose uptake in benign, nonphysiologic lesions found on whole-body positron emission tomography/computed tomography (PET/CT): accumulated data from four years of experience with PET/CT.

    PubMed

    Metser, Ur; Even-Sapir, Einat

    2007-05-01

    The use of (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) in the field of oncology is rapidly evolving; however, (18)F-FDG is not tumor specific. Aside from physiological uptake (18)F-FDG also may accumulate in benign processes. Knowledge of these (18)F-FDG-avid nonmalignant lesions is essential for accurate PET interpretation in oncologic patients to avoid a false-positive interpretation. Through the systematic review of the reports of PET/computed tomography (CT) studies performed in oncologic patients during a 6-month period, we found benign nonphysiological uptake of (18)F-FDG in more than 25% of studies. In half of these, (18)F-FDG uptake was moderate or marked in intensity, similar to that of malignant sites. A total of 73% of benign lesions were inflammatory in nature, with post-traumatic bone and soft-tissue abnormalities (including iatrogenic injury) and benign tumors accounting for the remainder. The differentiation of benign from malignant uptake of (18)F-FDG on PET alone may be particularly challenging as a result of the low anatomical resolution of PET and paucity of anatomical landmarks. Fusion imaging, namely PET/CT, has been shown to improve not only the sensitivity of PET interpretation but also its specificity. Aside from better anatomical localization of lesions on PET/CT, morphological characterization of lesions on CT often may improve the diagnostic accuracy of nonspecific (18)F-FDG uptake. Correlation with CT on fused PET/CT data may obviate the need for further evaluation or biopsy in more than one-third of scintigraphic equivocal lesions. Familiarity with (18)F-FDG-avid nonmalignant lesions also may extend the use of (18)F-FDG-PET imaging beyond the field of oncology. We have tabulated our experience with benign entities associated with increased (18)F-FDG uptake on whole-body PET/CT from 12,000 whole-body (18)F-FDG-PET/CT studies performed during a 4-year period.

  6. Impact of pretreatment whole-tumor perfusion computed tomography and 18F-fluorodeoxyglucose positron emission tomography/computed tomography measurements on local control of non–small cell lung cancer treated with stereotactic body radiotherapy

    PubMed Central

    Aoki, Masahiko; Akimoto, Hiroyoshi; Sato, Mariko; Hirose, Katsumi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Seino, Hiroko; Kakehata, Shinya; Tsushima, Fumiyasu; Fujita, Hiromasa; Fujita, Tamaki; Fujioka, Ichitaro; Tanaka, Mitsuki; Miura, Hiroyuki; Ono, Shuichi; Takai, Yoshihiro

    2016-01-01

    This study aimed to investigate the correlation between the average iodine density (AID) detected by dual-energy computed tomography (DE-CT) and the maximum standardized uptake value (SUVmax) yielded by [18F] fluorodeoxyglucose positron emission tomography (18F-FDG PET) for non–small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). Seventy-four patients with medically inoperable NSCLC who underwent both DE-CT and 18F-FDG PET/CT before SBRT (50‒60 Gy in 5‒6 fractions) were followed up after a median interval of 24.5 months. Kaplan–Meier analysis was used to determine associations between local control (LC) and variables, including AID, SUVmax, tumor size, histology, and prescribed dose. The median AID and SUVmax were 18.64 (range, 1.18–45.31) (100 µg/cm3) and 3.2 (range, 0.7–17.6), respectively. No correlation was observed between AID and SUVmax. Two-year LC rates were 96.2% vs 75.0% (P = 0.039) and 72.0% vs 96.2% (P = 0.002) for patients classified according to high vs low AID or SUVmax, respectively. Two-year LC rates for patients with adenocarcinoma vs squamous cell carcinoma vs unknown cancer were 96.4% vs 67.1% vs 92.9% (P = 0.008), respectively. Multivariate analysis identified SUVmax as a significant predictor of LC. The 2-year LC rate was only 48.5% in the subgroup of lower AID and higher SUVmax vs >90% (range, 94.4–100%) in other subgroups (P = 0.000). Despite the short follow-up period, a reduction in AID and subsequent increase in SUVmax correlated significantly with local failure in SBRT-treated NSCLC patients. Further studies involving larger populations and longer follow-up periods are needed to confirm these results. PMID:27296251

  7. Metabolic Response of Lymph Nodes Immediately After RT Is Related With Survival Outcome of Patients With Pelvic Node-Positive Cervical Cancer Using Consecutive [{sup 18}F]fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography

    SciTech Connect

    Yoon, Mee Sun; Ahn, Sung-Ja; Nah, Byung-Sik; Chung, Woong-Ki; Song, Ho-Chun; Yoo, Su Woong; Song, Ju-Young; Jeong, Jae-Uk; Nam, Taek-Keun

    2012-11-15

    Purpose: To evaluate the metabolic response of uterine cervix and pelvic lymph nodes (LNs) using consecutive {sup 18}F-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) immediately after RT and to correlate survival outcome with the metabolic response. Methods and Materials: We retrospectively reviewed 48 patients with cervical cancer who had positive pelvic LNs by preradiation therapy (pre-RT) PET/CT. All patients underwent PET/CT scans immediately after RT (inter-RT PET/CT) after median 63 Gy to the gross LNs. The metabolic response of the LNs was assessed quantitatively and semiquantitatively by measurement of the maximal standardized uptake value (SUV{sub max}). Results: Classifying the metabolic response of all nodal lesions, 37 patients (77%) had LNs with complete metabolic response on the inter-RT PET/CT (LNCMRi), and 11 patients had a non-LNCMRi, including 4 patients with progressive metabolic disease. The overall 3-year survival rates were 83% for the patients with LNCMRi and 73% for the non-LNCMRi group (P=.038). The disease-free survival for patients with LNCMRi were significantly better than that for the non-LNCMRi group (71% vs 18%, respectively, P<.001). The 3-year distant metastasis-free survival rates were 79% for the patients with LNCMRi and 27% for the non-LNCMRi group (P<.001). There were no statistically significant differences in overall survival (76% vs 86%, respectively, P=.954) and disease-free survival rates (58% vs 61%, respectively, P=.818) between the CMR of primary cervical tumor and the non-CMR groups. Conclusions: The results showed a significant correlation between survival outcome and the interim metabolic response of pelvic LNs. CMR of nodal lesion on inter-RT PET/CT had excellent overall survival, disease-free survival and distant metastasis-free survival rates. This suggested that PET/CT immediately after RT can be a useful tool for the evaluation of the interim response of the LNs and identify a subset

  8. Impact of (18)f-fluorodeoxyglucose positron emission tomography/computed tomography scan on initial evaluation of head and neck squamous cell carcinoma: our experience at a tertiary care center in India.

    PubMed

    Nair, Satish; Mohan, Sharad; Nilakantan, Ajith; Gupta, Atul; Malik, Akshat; Gupta, Abhishek

    2015-01-01

    The efficacy of the whole body (WB) (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) as a part of conventional initial staging in all cases of head and neck squamous cell carcinoma (HNSCC) is still controversial with various studies in literature giving contradictory reports. We conducted this study at a government tertiary care oncology center in India to identify the impact of WB (18)F-FDG PET-CT scan on HNSCC staging and treatment. A prospective clinical study of patients of HNSCC who were evaluated and treated at our center was performed. The patients included in the study were HNSCC of the oral cavity, oropharynx, hypopharynx, larynx, nasopharynx, and carcinoma of unknown primary site (CUPS) with cervical metastasis. The study design was to evaluate the cases of HNSCC initially by staging with conventional investigations followed by staging with the information derived from WB (18)F-FDG PET-CT scan. At the end of the conventional investigations, a tumor, node, metastasis (TNM) staging as per AJCC 7(th) edition, and a detailed treatment plan as per NCCN 2012 guidelines was decided in consultation with the multidisciplinary oncology team of the hospital. WB (18)F-FDG PET-CT scan was carried out in all these patients. The findings of WB (18)F-FDG PET-CT were then interpreted with the staging with conventional investigations to identify the cases with change in staging and also those in whom the treatment protocol would be affected. Descriptive analysis of demographic data and analytical analysis of the sensitivity and specificity of WB (18)F-FDG PET-CT scan and also the change in staging and treatment plan after WB (18)F-FDG PET-CT scan was analyzed using SPSS version 18. A total of 131 patients met the inclusion criteria, which included 123 males and 8 females. The various sites involved among the study group are oral cavity 11 (8.3%), oropharyn × 39 (29.7%), hypopharyn × 31 (23.6%), laryn × 34 (25.9%), nasopharyn

  9. Pelvic Lymph Node Status Assessed by 18F-Fluorodeoxyglucose Positron Emission Tomography Predicts Low-Risk Group for Distant Recurrence in Locally Advanced Cervical Cancer: A Prospective Study

    SciTech Connect

    Kang, Sokbom; Park, Jung-Yeol; Lim, Myung-Chul; Song, Yong-Joong; Park, Se-Hyun; Kim, Seok-Ki; Chung, Dae-Chul; Seo, Sang-Soo; Kim, Joo-Young; Park, Sang-Yoon

    2011-03-01

    Purpose: To develop a prediction model to identify a low-risk group for distant recurrence in patients with locally advanced cervical cancer treated by concurrent chemoradiation. Methods and Materials: Prospectively, 62 patients with locally advanced cervical cancer were recruited as a training cohort. Clinical variables and parameters obtained from positron emission tomography (PET) and magnetic resonance imaging were analyzed by logistic regression. For the test set, 54 patients were recruited independently. To identify the low-risk group, negative likelihood ratio (LR) less than 0.2 was set to be a cutoff. Results: Among the training cohort, multivariate logistic analysis revealed that advanced International Federation of Gynecology and Obstetrics (FIGO) stage and a high serum squamous cancer cell (SCC) antigen level were significant risk factors (p = 0.015 and 0.025, respectively). Using the two parameters, criteria to determine a low-risk subset for distant recurrence were postulated: (1) FIGO Stage IIB or less and (2) pretreatment SCC < 2.4 (Model A). Positive pelvic node on PET completely predicted all cases with distant recurrence and thus was considered as another prediction model (Model B). In the test cohort, although Model A did not showed diagnostic performance, Model B completely predicted all cases with distant recurrence and showed a sensitivity of 100% with negative LR of 0. Across the training and test cohort (n = 116), the false negative rate was 0 (95% confidence interval 0%-7.6%). Conclusions: Positive pelvic node on PET is a useful marker in prediction of distant recurrence in patients with locally advanced cervical cancer who are treated with concurrent chemoradiation.

  10. Emission computed tomography of /sup 18/F-fluorodeoxyglucose and /sup 13/N-ammonia in stroke and epilepsy

    SciTech Connect

    Kuhl, D.E.; Phelps, M.E.; Engel, J. Jr.

    1980-01-01

    The ECAT Positron Tomograph was used to scan normal control subjects, stroke patients at various times during recovery, and patients with partial epilepsy during EEG monitoring. /sup 18/F-fluorodeoxyglucose (/sup 18/FDG) and /sup 13/N-Ammonia (/sup 13/NH/sub 3/) were used as indicators of abnormalities in local cerebral glucose utilization (LCMR/sub glc/) and relative perfusion, respectively. Hypometabolism, due to deactivation or minimal damage, was demonstrated with the /sup 18/FDG scan in deep structures and broad zones of cerebral cortex which appeared normal on x-ray CT (XCT) and /sup 99m/Tc pertechnetate scans. In patients with partial epilepsy, who had unilateral or focal electrical abnormalities, interictal /sup 18/FDG scan patterns clearly showed localized regions of decreased (20 to 50%) LCMR/sub glc/, which correlated anatomically with the eventual EEG localization.

  11. Change of Maximum Standardized Uptake Value Slope in Dynamic Triphasic [{sup 18}F]-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Distinguishes Malignancy From Postradiation Inflammation in Head-and-Neck Squamous Cell Carcinoma: A Prospective Trial

    SciTech Connect

    Anderson, Carryn M.; Chang, Tangel; Graham, Michael M.; Marquardt, Michael D.; Button, Anna; Smith, Brian J.; Menda, Yusuf; Sun, Wenqing; Pagedar, Nitin A.; Buatti, John M.

    2015-03-01

    Purpose: To evaluate dynamic [{sup 18}F]-fluorodeoxyglucose (FDG) uptake methodology as a post–radiation therapy (RT) response assessment tool, potentially enabling accurate tumor and therapy-related inflammation differentiation, improving the posttherapy value of FDG–positron emission tomography/computed tomography (FDG-PET/CT). Methods and Materials: We prospectively enrolled head-and-neck squamous cell carcinoma patients who completed RT, with scheduled 3-month post-RT FDG-PET/CT. Patients underwent our standard whole-body PET/CT scan at 90 minutes, with the addition of head-and-neck PET/CT scans at 60 and 120 minutes. Maximum standardized uptake values (SUV{sub max}) of regions of interest were measured at 60, 90, and 120 minutes. The SUV{sub max} slope between 60 and 120 minutes and change of SUV{sub max} slope before and after 90 minutes were calculated. Data were analyzed by primary site and nodal site disease status using the Cox regression model and Wilcoxon rank sum test. Outcomes were based on pathologic and clinical follow-up. Results: A total of 84 patients were enrolled, with 79 primary and 43 nodal evaluable sites. Twenty-eight sites were interpreted as positive or equivocal (18 primary, 8 nodal, 2 distant) on 3-month 90-minute FDG-PET/CT. Median follow-up was 13.3 months. All measured SUV endpoints predicted recurrence. Change of SUV{sub max} slope after 90 minutes more accurately identified nonrecurrence in positive or equivocal sites than our current standard of SUV{sub max} ≥2.5 (P=.02). Conclusions: The positive predictive value of post-RT FDG-PET/CT may significantly improve using novel second derivative analysis of dynamic triphasic FDG-PET/CT SUV{sub max} slope, accurately distinguishing tumor from inflammation on positive and equivocal scans.

  12. Pulmonary artery intimal sarcoma: poor 18F-fluorodeoxyglucose uptake in positron emission computed tomography.

    PubMed

    Lee, Dong-Hyup; Jung, Tae-Eun; Lee, Jang-Hoon; Shin, Dong-Gu; Park, Won-Jong; Choi, Jun-Hyuk

    2013-03-07

    Intimal sarcoma of the pulmonary artery is a rare malignant tumor that may be misdiagnosed as chronic pulmonary thromboembolism, even if various imaging techniques are used. We report a case of a 58-year-old man with pulmonary artery intimal sarcoma.18F-fleuorodeoxyglucose (FDG) uptake was poor in the mass of the pulmonary artery, and no other hypermetabolic lesions were noted elsewhere. Our presumptive diagnosis was a massive mural thrombus and a concomitant chronic thromboembolism. Intravenous heparin and recombinant human tissue-type plasminogen activator was subsequently administered. However, the patient needed an emergency operation for sudden aggravation of the vital signs, and the tissue diagnosis was intimal sarcoma with poor clinical outcomes.

  13. Mechanisms underlying 18F-fluorodeoxyglucose accumulation in colorectal cancer

    PubMed Central

    Kawada, Kenji; Iwamoto, Masayoshi; Sakai, Yoshiharu

    2016-01-01

    Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) is a diagnostic tool to evaluate metabolic activity by measuring accumulation of FDG, an analogue of glucose, and has been widely used for detecting small tumors, monitoring treatment response and predicting patients’ prognosis in a variety of cancers. However, the molecular mechanism of FDG accumulation into tumors remains to be investigated. It is well-known that most cancers are metabolically active with elevated glucose metabolism, a phenomenon known as the Warburg effect. The underlying mechanisms for elevated glucose metabolism in cancer tissues are complex. Recent reports have indicated the potential of FDG-PET/CT scans in predicting mutational status (e.g., KRAS gene mutation) of colorectal cancer (CRC), which suggests that FDG-PET/CT scans may play a key role in determining therapeutic strategies by non-invasively predicting treatment response to anti-epidermal growth factor receptor (EGFR) therapy. In this review, we summarize the current findings investigating the molecular mechanism of 18F-FDG accumulation in CRC. PMID:27928469

  14. Lung [18F]fluorodeoxyglucose uptake and ventilation-perfusion mismatch in the early stage of experimental acute smoke inhalation

    PubMed Central

    Musch, Guido; Winkler, Tilo; Harris, R. Scott; Vidal Melo, Marcos F.; Wellman, Tyler J.; de Prost, Nicolas; Kradin, Richard L.; Venegas, Jose G.

    2014-01-01

    Background Acute lung injury (ALI) occurs in a third of patients with smoke inhalation injury. Its clinical manifestations usually do not appear until 48 to 72 h after inhalation. Identifying inflammatory changes that occur in pulmonary parenchyma earlier than that could provide insight into the pathogenesis of smoke-induced ALI. Furthermore, noninvasive measurement of such changes might lead to earlier diagnosis and treatment. Because glucose is the main source of energy for pulmonary inflammatory cells, we hypothesized that its pulmonary metabolism is increased shortly after smoke inhalation, when classic manifestations of ALI are not yet expected. Methods In five sheep we induced unilateral injury with 48 breaths of cotton smoke while the contralateral lung served as control. We used positron emission tomography with: 1) [18F]fluorodeoxyglucose to measure pulmonary inflammatory cell metabolic activity; and 2) [13N]nitrogen in saline to measure shunt and ventilation-perfusion distributions separately in the smoke-exposed and control lungs. Results The pulmonary [18F]fluorodeoxyglucose uptake rate was increased at 4 h after smoke inhalation (mean ± SD: 0.0031 ± 0.0013 vs. 0.0026 ± 0.0010 min−1, P < 0.05) mainly as a result of increased glucose phosphorylation. At this stage there was no worsening in lung aeration or shunt. However, there was a shift of perfusion toward units with lower ventilation-to-perfusion ratio (mean ratio ± SD: 0.82 ± 0.10 vs. 1.12 ± 0.02, P < 0.05) and increased heterogeneity of the ventilation-perfusion distribution (mean ± SD: 0.21 ± 0.07 vs. 0.13 ± 0.01, P < 0.05). Conclusion Using noninvasive imaging we demonstrated that increased pulmonary [18F]fluorodeoxyglucose uptake and ventilation-perfusion mismatch occur early after smoke inhalation. PMID:24051392

  15. Glucose Metabolism Gene Expression Patterns and Tumor Uptake of {sup 18}F-Fluorodeoxyglucose After Radiation Treatment

    SciTech Connect

    Wilson, George D.; Thibodeau, Bryan J.; Fortier, Laura E.; Pruetz, Barbara L.; Galoforo, Sandra; Baschnagel, Andrew M.; Chunta, John; Oliver Wong, Ching Yee; Yan, Di; Marples, Brian; Huang, Jiayi

    2014-11-01

    Purpose: To investigate whether radiation treatment influences the expression of glucose metabolism genes and compromises the potential use of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG-PET) as a tool to monitor the early response of head and neck cancer xenografts to radiation therapy (RT). Methods and Materials: Low passage head and neck squamous cancer cells (UT14) were injected to the flanks of female nu/nu mice to generate xenografts. After tumors reached a size of 500 mm{sup 3} they were treated with either sham RT or 15 Gy in 1 fraction. At different time points, days 3, 9, and 16 for controls and days 4, 7, 12, 21, 30, and 40 after irradiation, 2 to 3 mice were assessed with dynamic FDG-PET acquisition over 2 hours. Immediately after the FDG-PET the tumors were harvested for global gene expression analysis and immunohistochemical evaluation of GLUT1 and HK2. Different analytic parameters were used to process the dynamic PET data. Results: Radiation had no effect on key genes involved in FDG uptake and metabolism but did alter other genes in the HIF1α and glucose transport–related pathways. In contrast to the lack of effect on gene expression, changes in the protein expression patterns of the key genes GLUT1/SLC2A1 and HK2 were observed after radiation treatment. The changes in GLUT1 protein expression showed some correlation with dynamic FDG-PET parameters, such as the kinetic index. Conclusion: {sup 18}F-fluorodeoxyglucose positron emission tomography changes after RT would seem to represent an altered metabolic state and not a direct effect on the key genes regulating FDG uptake and metabolism.

  16. Single-Cell Analysis of [18F]Fluorodeoxyglucose Uptake by Droplet Radiofluidics

    PubMed Central

    Türkcan, Silvan; Nguyen, Julia; Vilalta, Marta; Shen, Bin; Chin, Frederick T.; Pratx, Guillem; Abbyad, Paul

    2015-01-01

    Radiolabels can be used to detect small biomolecules with high sensitivity and specificity, and without interfering with the biochemical activity of the labeled molecule. For instance, the radiolabeled glucose analogue, [18F]fluorodeoxyglucose (FDG), is routinely used in positron emission tomography (PET) scans for cancer diagnosis, staging and monitoring. However, despite their widespread usage, conventional radionuclide techniques are unable to measure the variability and modulation of FDG uptake in single cells. We present here a novel microfluidic technique, dubbed droplet radiofluidics, that can measure radiotracer uptake for single cells encapsulated into an array of microdroplets. The advantages of this approach are multiple. First, droplets can be quickly and easily positioned in a predetermined pattern for optimal imaging throughput. Second, droplet encapsulation reduces cell efflux as a confounding factor, because any effluxed radionuclide is trapped in the droplet. Last, multiplexed measurements can be performed using fluorescent labels. In this new approach, intracellular radiotracers are imaged on a conventional fluorescence microscope by capturing individual flashes of visible light that are produced as individual positrons, emitted during radioactive decay, traverse a scintillator plate placed below the cells. This method is used to measure the cell-to-cell heterogeneity in the uptake of tracers such as FDG in cell lines and cultured primary cells. The capacity of the platform to perform multiplexed measurements was demonstrated by measuring differential FDG uptake in single cells subjected to different incubation conditions and expressing different types of glucose transporters. This method opens many new avenues of research in basic cell biology and human disease by capturing the full range of stochastic variations in highly heterogeneous cell populations in a repeatable and high-throughput manner. PMID:26035453

  17. Asymptomatic Emphysematous Pyelonephritis - Positron Emission Tomography Computerized Tomography Aided Diagnostic and Therapeutic Elucidation

    PubMed Central

    Pathapati, Deepti; Shinkar, Pawan Gulabrao; kumar, Satya Awadhesh; Jha; Dattatreya, Palanki Satya; Chigurupati, Namrata; Chigurupati, Mohana Vamsy; Rao, Vatturi Venkata Satya Prabhakar

    2017-01-01

    The authors report an interesting coincidental unearthing by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) of a potentially serious medical condition of emphysematous pyelonephritis in a case of nasopharyngeal carcinoma. The management by conservative ureteric stenting and antibiotics was done with gratifying clinical outcome. PMID:28242985

  18. The accuracy of positron emission tomography in the detection of posttransplant lymphoproliferative disorder.

    PubMed

    Dierickx, Daan; Tousseyn, Thomas; Requilé, Annelies; Verscuren, Raf; Sagaert, Xavier; Morscio, Julie; Wlodarska, Iwona; Herreman, An; Kuypers, Dirk; Van Cleemput, Johan; Nevens, Frederik; Dupont, Lieven; Uyttebroeck, Anne; Pirenne, Jacques; De Wolf-Peeters, Christiane; Verhoef, Gregor; Brepoels, Lieselot; Gheysens, Olivier

    2013-05-01

    We investigated sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-fluorodeoxyglucose-positron emission tomography in 170 cases with suspected or biopsy-proven posttransplant lymphoproliferative disorder. All solid organ and hematopoietic stem cell transplant recipients who underwent an 18F-fluorodeoxyglucose-positron emission tomography scan between 2003 and 2010 in our center for the indication posttransplant lymphoproliferative disorder, were retrospectively reviewed and results were compared with tissue biopsy whenever possible. One hundred and seventy positron emission tomography scans in 150 patients were eligible for evaluation. In 45 cases, the patient had a biopsy-confirmed posttransplant lymphoproliferative disorder before positron emission tomography scanning and positron emission tomography was performed for staging purposes. In the remaining 125 cases, positron emission tomography was performed to differentiate between posttransplant lymphoproliferative disorder and other diseases. 18F-fluorodeoxyglucose-uptake was quantitatively expressed by calculation of maximum and mean standardized uptake value in the most intense lesion or, in the absence of attenuation corrected positron emission tomography scans, by comparing uptake in target lesion to liver and mediastinal uptake. We found an overall sensitivity of 89%, specificity of 89%, positive predictive value of 91% and negative predictive value of 87% for posttransplant lymphoproliferative disorder detection by 18F-fluorodeoxyglucose-positron emission tomography. In a subanalysis of the 125 scans performed for differentiating posttransplant lymphoproliferative disorder from other diseases, sensitivity, specificity, positive predictive value and negative predictive value were 90%, 89%, 85% and 93%, respectively. 18F-fluorodeoxyglucose-uptake in posttransplant lymphoproliferative disorder was generally high with a median mean and maximum standardized uptake

  19. The accuracy of positron emission tomography in the detection of posttransplant lymphoproliferative disorder

    PubMed Central

    Dierickx, Daan; Tousseyn, Thomas; Requilé, Annelies; Verscuren, Raf; Sagaert, Xavier; Morscio, Julie; Wlodarska, Iwona; Herreman, An; Kuypers, Dirk; Van Cleemput, Johan; Nevens, Frederik; Dupont, Lieven; Uyttebroeck, Anne; Pirenne, Jacques; De Wolf-Peeters, Christiane; Verhoef, Gregor; Brepoels, Lieselot; Gheysens, Olivier

    2013-01-01

    We investigated sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-fluorodeoxyglucose-positron emission tomography in 170 cases with suspected or biopsy-proven posttransplant lymphoproliferative disorder. All solid organ and hematopoietic stem cell transplant recipients who underwent an 18F-fluorodeoxyglucose-positron emission tomography scan between 2003 and 2010 in our center for the indication posttransplant lymphoproliferative disorder, were retrospectively reviewed and results were compared with tissue biopsy whenever possible. One hundred and seventy positron emission tomography scans in 150 patients were eligible for evaluation. In 45 cases, the patient had a biopsy-confirmed posttransplant lymphoproliferative disorder before positron emission tomography scanning and positron emission tomography was performed for staging purposes. In the remaining 125 cases, positron emission tomography was performed to differentiate between posttransplant lymphoproliferative disorder and other diseases. 18F-fluorodeoxyglucose-uptake was quantitatively expressed by calculation of maximum and mean standardized uptake value in the most intense lesion or, in the absence of attenuation corrected positron emission tomography scans, by comparing uptake in target lesion to liver and mediastinal uptake. We found an overall sensitivity of 89%, specificity of 89%, positive predictive value of 91% and negative predictive value of 87% for posttransplant lymphoproliferative disorder detection by 18F-fluorodeoxyglucose-positron emission tomography. In a subanalysis of the 125 scans performed for differentiating posttransplant lymphoproliferative disorder from other diseases, sensitivity, specificity, positive predictive value and negative predictive value were 90%, 89%, 85% and 93%, respectively. 18F-fluorodeoxyglucose-uptake in posttransplant lymphoproliferative disorder was generally high with a median mean and maximum standardized uptake

  20. Magnetic resonance imaging and positron emission tomography of band heterotopia.

    PubMed

    Miura, K; Watanabe, K; Maeda, N; Matsumoto, A; Kumagai, T; Ito, K; Kato, T

    1993-01-01

    A case of band heterotopia was reported with findings of positron emission tomography (PET). The patient was an 8-year-old girl who had mild mental retardation and intractable partial epilepsy. Her MRI showed another diffuse layer of gray matter underlying the normal-looking cortex and separated from it by an apparently normal layer of white matter. PET scan with [18F]fluorodeoxyglucose revealed that band heterotopia had the same degree of glucose metabolism as that of the overlying cortex.

  1. Localized 18F-fluorodeoxyglucose uptake at the pancreatic head during remission phase of autoimmune pancreatitis: A case report

    PubMed Central

    Yonenaga, Yoshikuni; Kushihata, Fumiki; Watanabe, Jota; Tohyama, Taiji; Inoue, Hitoshi; Sugita, Atsuro; Takada, Yasutsugu

    2016-01-01

    Autoimmune pancreatitis (AIP) is a unique form of pancreatitis, histopathologically characterized by dense lymphoplasmacytic infiltration and fibrosis of the pancreas with obliterative phlebitis. AIP is associated with a good response to steroid therapy. Differentiation between AIP and pancreatic cancer to determine a preoperative diagnosis is often challenging, despite the use of various diagnostic modalities, including computed tomography (CT), magnetic resonance imaging and endoscopic retrograde cholangiopancreatography. It has been reported that 18F-fluorodeoxyglucose (18F-FDG)-positron emission tomography (PET)/CT may be a useful tool for distinguishing between the two diseases. In the present case report, a 71-year-old male patient presented with a well-circumscribed, solitary, nodular and homogenous 18F-FDG uptake at the pancreatic head, while receiving maintenance steroid therapy in the remission phase of AIP; preoperatively, the patient had been strongly suspected of having pancreatic cancer. Pathological examination revealed post-treatment relapse of AIP. The present case highlights the diagnostic and management difficulties with AIP in the remission phase. In certain cases, it remains challenging to differentiate the two diseases, even using the latest modalities. PMID:27602112

  2. Adding Maximum Standard Uptake Value of Primary Lesion and Lymph Nodes in 18F-Fluorodeoxyglucose PET Helps Predict Distant Metastasis in Patients with Nasopharyngeal Carcinoma

    PubMed Central

    Zhang, Yingjian; Hu, Chaosu

    2014-01-01

    Objective To find out the most valuable parameter of 18F-Fluorodeoxyglucose positron emission tomography for predicting distant metastasis in nasopharyngeal carcinoma. Methods From June 2007 through December 2010, 43 non-metastatic NPC patients who underwent 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) before radical Intensity-Modulated Radiation Therapy were enrolled and reviewed retrospectively. PET parameters including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glucose (TLG) of both primary tumor and cervical lymph nodes were calculated. Total SUVmax were recorded as the sum of SUVmax of primary tumor and cervical lymph nodes. Total SUVmean, Total MTV and Total TLG were calculated in the same way as Total SUVmax. Results The median follow-up was 32 months (range, 23–68 months). Distant metastasis was the main pattern of treatment failure. Univariate analysis showed higher SUVmax, SUVmean, MTV, and TLG of primary tumor, Total SUVmax, Total MTV, Total TLG, and stage T3-4 were factors predicting for significantly poorer distant metastasis-free survival (p = 0.042, p = 0.008, p = 0.023, p = 0.023, p = 0.024, p = 0.033, p = 0.016, p = 0.015). In multivariate analysis, Total SUVmax was the independent predictive factor for distant metastasis (p = 0.046). Spearman Rank correlation analysis showed mediate to strong correlationship between Total SUVmax and SUVmax-T, and between Total SUVmax and SUVmax-N(Spearman coefficient:0.568 and 0.834;p = 0.000 and p = 0.000). Conclusions Preliminary results indicated that Total SUVmax was an independently predictive factor for distant metastasis in patients of nasopharyngeal carcinoma treated with Intensity-Modulated Radiation Therapy. PMID:25068373

  3. Low-carbohydrate diet versus euglycemic hyperinsulinemic clamp for the assessment of myocardial viability with 18F-fluorodeoxyglucose-PET: a pilot study.

    PubMed

    Soares, José; Rodrigues Filho, Filadelfo; Izaki, Marisa; Giorgi, Maria Clementina P; Catapirra, Rosa M A; Abe, Rubens; Vinagre, Carmen G C M; Cerri, Giovanni G; Meneghetti, José Cláudio

    2014-02-01

    Positron emission tomography with (18)F-fluorodeoxyglucose (FDG-PET) is considered the gold standard for myocardial viability. A pilot study was undertaken to compare FDG-PET using euglycemic hyperinsulinemic clamp before (18)F-fluorodeoxyglucose ((18)F-FDG) administration (PET-CLAMP) with a new proposed technique consisting of a 24-h low-carbohydrate diet before (18)F-FDG injection (PET-DIET), for the assessment of hypoperfused but viable myocardium (hibernating myocardium). Thirty patients with previous myocardial infarction were subjected to rest (99m)Tc-sestamibi-SPECT and two (18)F-FDG studies (PET-CLAMP and PET-DIET). Myocardial tracer uptake was visually scored using a 5-point scale in a 17-segment model. Hibernating myocardium was defined as normal or mildly reduced metabolism ((18)F-FDG uptake) in areas with reduced perfusion ((99m)Tc-sestamibi uptake) since (18)F-FDG uptake was higher than the degree of hypoperfusion-perfusion/metabolism mismatch indicating a larger flow defect. PET-DIET identified 79 segments and PET-CLAMP 71 as hibernating myocardium. Both methods agreed in 61 segments (agreement = 94.5 %, κ = 0.78). PET-DIET identified 230 segments and PET-CLAMP 238 as nonviable. None of the patients had hypoglycemia after DIET, while 20 % had it during CLAMP. PET-DIET compared with PET-CLAMP had a good correlation for the assessment of hibernating myocardium. To our knowledge, these data provide the first evidence of the possibility of myocardial viability assessment with this technique.

  4. Impact of [{sup 18}F] Fluorodeoxyglucose Positron Emission Tomography on Staging and Management of Early-Stage Follicular Non-Hodgkin Lymphoma

    SciTech Connect

    Wirth, Andrew Foo, Marcus; Seymour, John F.; MacManus, Michael P.; Hicks, Rodney J.

    2008-05-01

    Purpose: Accurate staging is critical to select patients with early-stage (I-II) follicular lymphoma (ESFL) suitable for involved-field radiotherapy (IFRT) and to define the radiotherapy portal. We evaluated the impact of fluorodeoxyglucose (FDG) PET on staging, treatment, and outcome for patients with ESFL on conventional staging. Methods and Materials: Forty-two patients with untreated ESFL (World Health Organization Grade I-IIIa, or 'low grade') following a minimum of physical examination, computerized tomography, and bone marrow examination (conventional assessment) and who had staging PET from June 1997 to June 2006 were studied retrospectively. Stage allocation was based on routine imaging reports. Disease sites, stage, and management plan were recorded based on conventional assessment or conventional assessment plus PET. Results: FDG avidity was demonstrated in 97% of patients in whom disease was evident on conventional assessment after biopsy. PET findings suggested a change of stage or management in 19 patients: 13 (31%) who were upstaged to Stage III-IV, altering ideal management from IFRT to systemic therapy, and 6 (14%) who had the involved field enlarged, including 4 upstaged from Stage I to II. Of these 19 cases, PET findings were considered true positive in 8 patients, indeterminate in 10, and false positive in only 1 patient. Conclusions: Our data confirm that ESFL is usually FDG-avid. In routine practice, PET has the potential to upstage and thereby alter management in a high proportion of patients with apparent ESFL.

  5. Bimedial rectus hypermetabolism in convergence spasm as observed on positron emission tomography.

    PubMed

    Jeong, Seong-Hae; Oh, Young-Mi; Kim, Chae-Yong; Kim, Ji Soo

    2008-09-01

    A 52-year-old man developed vertical gaze palsy, convergence spasm, and convergence-retraction nystagmus due to glioblastoma of the right thalamus. 18F-fluorodeoxyglucose positron emission tomography (PET) inadvertently demonstrated markedly increased metabolism in the medial rectus muscles. The hypermetabolism indicates active contraction of these extraocular muscles due to excessive convergence drive attributed to inappropriate activation or disrupted inhibition of convergence neurons by the diencephalic lesion.

  6. Correlation of biomechanics to tissue reaction in aortic aneurysms assessed by finite elements and [18F]-fluorodeoxyglucose-PET/CT.

    PubMed

    Maier, Andreas; Essler, Markus; Gee, Michael W; Eckstein, Hans-Henning; Wall, Wolfgang A; Reeps, Christian

    2012-04-01

    Mechanobiological interactions are essential for the adaption of the cardiovascular system to altered environmental and internal conditions, but are poorly understood with regard to abdominal aortic aneurysm (AAA) pathogenesis, growth and rupture. In the present study, we therefore calculated mechanical AAA quantities using nonlinear finite element methods and correlated these to [18F]-fluorodeoxyglucose (FDG)-metabolic activity in the AAA wall detected by positron emission tomography/computed tomography (PET/CT). The interplay between mechanics and FDG-metabolic activity was analyzed in terms of maximum values and the three-dimensional spatial relationship, respectively. Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) data sets of n = 18 AAA patients were studied. Maximum FDG-uptake (SUV max ) in the AAA wall varied from 1.32 to 4.60 (average SUV max 3.31 ± 0.87). Maximum wall stresses and strains ranged from 10.0 to 64.0 N∕cm(2) (38.2 ± 13.8  N∕cm(2)) and from 0.190 to 0.260 (0.222 ± 0.023), respectively. SUV max was significantly correlated to maximum wall stress and strain (SUV max to stress: r = 0.71, p = 0.0005; SUV max to strain: r = 0.66, p = 0.0013). To evaluate the three-dimensional spatial interaction between FDG-uptake and acting wall stress, element-wise correlations were performed. In all but 2 AAAs, positive element-wise correlation of FDG-uptake to wall stress was obtained, with the Pearson's correlation coefficient ranging from -0.168 to 0.738 ( 0.372 ± 0.263). The results indicate that mechanical stresses are correlated quantitatively and spatially to FDG-uptake in the AAA wall. It is hypothesized that unphysiologically increased loading in the AAA wall triggers biological tissue reaction, such as inflammation or regenerative processes, causing elevated FDG-metabolic activity. These findings strongly support experimental hypotheses of mechanotransduction mechanisms in vivo.

  7. Functional Recovery after Scutellarin Treatment in Transient Cerebral Ischemic Rats: A Pilot Study with 18F-Fluorodeoxyglucose MicroPET

    PubMed Central

    Li, Jin-hui; Lu, Jing; Zhang, Hong

    2013-01-01

    Objective. To investigate neuroprotective effects of scutellarin (Scu) in a rat model of cerebral ischemia with use of 18F-fluorodeoxyglucose (18F-FDG) micro positron emission tomography (microPET). Method. Middle cerebral artery occlusion was used to establish cerebral ischemia. Rats were divided into 5 groups: sham operation, cerebral ischemia-reperfusion untreated (CIRU) group, Scu-25 group (Scu 25 mg/kg/d), Scu-50 group (Scu 50 mg/kg/d), and nimodipine (10 mg/Kg/d). The treatment groups were given for 2 weeks. The therapeutic effects in terms of cerebral infarct volume, neurological deficit scores, and cerebral glucose metabolism were evaluated. Levels of vascular density factor (vWF), glial marker (GFAP), and mature neuronal marker (NeuN) were assessed by immunohistochemistry. Results. The neurological deficit scores were significantly decreased in the Scu-50 group compared to the CIRU group (P < 0.001). 18F-FDG accumulation in the ipsilateral cerebral infarction increased steadily over time in Scu-50 group compared with CIRU group (P < 0.01) and Scu-25 group (P < 0.01). Immunohistochemical analysis demonstrated Scu-50 enhanced neuronal maturation. Conclusion. 18F-FDG microPET imaging demonstrated metabolic recovery after Scu-50 treatment in the rat model of cerebral ischemia. The neuroprotective effects of Scu on cerebral ischemic injury might be associated with increased regional glucose activity and neuronal maturation. PMID:23737833

  8. Clusters of Low (18)F-Fluorodeoxyglucose Uptake Voxels in Combat Veterans with Traumatic Brain Injury and Post-Traumatic Stress Disorder.

    PubMed

    Buchsbaum, Monte S; Simmons, Alan N; DeCastro, Alex; Farid, Nikdokht; Matthews, Scott C

    2015-11-15

    Individuals with mild traumatic brain injury (TBI) show diminished metabolic activity when studied with positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG). Since blast injury may not be localized in the same specific anatomical areas in every patient or may be diffuse, significance probability mapping may be vulnerable to false-negative detection of abnormalities. To address this problem, we used an anatomically independent measure to assess PET scans: increased numbers of contiguous voxels that are 2 standard deviations below values found in an uninjured control group. We examined this in three age-matched groups of male patients: 16 veterans with a history of mild TBI, 17 veterans with both mild TBI and post-traumatic stress disorder (PTSD), and 15 veterans without either condition. After FDG administration, subjects performed a modified version of the California Verbal Learning Task. Clusters of low uptake voxels were identified by computing the mean and standard deviation for each voxel in the healthy combat veteran group and then determining the voxel-based z-score for the patient groups. Abnormal clusters were defined as those that contained contiguous voxels with a z-score <-2. Patients with mild TBI alone and patients with TBI+PTSD had larger clusters of low uptake voxels, and cluster size significantly differentiated the mild TBI groups from combat controls. Clusters were more irregular in shape in patients, and patients also had a larger number of low-activity voxels throughout the brain. In mild TBI and TBI+PTSD patients, but not healthy subjects, cluster volume was significantly correlated with verbal learning during FDG uptake.

  9. Renal Metastasis and Dual (18F-Fluorodeoxyglucose and 131I) Avid Skeletal Metastasis in a Patient with Papillary Thyroid Cancer

    PubMed Central

    Kulkarni, Prashanth; Rekha, Pobbi Setty Radhakrishna Gupta; Prabhu, Meghana; Venkataramarao, Sunil Hejjaji; Raju, Nalini; Chandrasekhar, Naveen Hedne; Kannan, Subramanian

    2017-01-01

    Differentiated thyroid carcinoma (DTC) though usually behaves in an indolent manner, can have unusual metastatic presentation. Initial presentation of metastatic disease has been reported in 1–12% of DTC being less frequent in papillary (~2%) than in follicular (~10%) thyroid carcinoma. Renal metastasis from DTC is very rare. To our knowledge, only about 30 cases have been reported in the English literature to date. To make clinicians aware that management of such high-risk thyroid cancer frequently requires novel multimodality imaging and therapeutic techniques. A 72-year-old female is described who presented with abdominal pain and bilateral lower limbs swelling. Initial contrast enhanced computed tomography (CT) scan of abdomen showed a well-encapsulated mass in the upper pole of right kidney favoring a renal cell carcinoma. Postright sided radical nephrectomy, histopathology, and immunohistochemistry reports suggested metastatic deposits from thyroid malignancy. 18F-fluorodeoxyglucose (FDG) positron emission tomography-CT demonstrated hypermetabolic nodule in the left lobe of thyroid and a lytic lesion involving left acetabulum suggestive of skeletal metastasis. Subsequently, ultrasound-guided fine needle aspiration cytology of the thyroid nodules in bilateral lobes confirmed thyroid malignancy (Bethesda 6/6). Total thyroidectomy revealed papillary thyroid cancer (PTC) (follicular variant-PTC [FV-PTC]). After surgery, 131I-whole body scan showed iodine avid lytic lesion in the left acetabulum. The present case is a rare scenario of a renal metastasis as the presenting feature of an FV-PTC. Dual avidity in metastatic thyroid cancers (iodine and FDG) is rare and based on the degree of dedifferentiation of the DTC. PMID:28242987

  10. Mild experimental ketosis increases brain uptake of 11C-acetoacetate and 18F-fluorodeoxyglucose: a dual-tracer PET imaging study in rats.

    PubMed

    Pifferi, Fabien; Tremblay, Sébastien; Croteau, Etienne; Fortier, Mélanie; Tremblay-Mercier, Jennifer; Lecomte, Roger; Cunnane, Stephen C

    2011-03-01

    Brain glucose and ketone uptake was investigated in Fisher rats subjected to mild experimental ketonemia induced by a ketogenic diet (KD) or by 48 hours fasting (F). Two tracers were used, (11)C-acetoacetate ((11)C-AcAc) for ketones and (18)F-fluorodeoxyglucose for glucose, in a dual-tracer format for each animal. Thus, each animal was its own control, starting first on the normal diet, then undergoing 48 hours F, followed by 2 weeks on the KD. In separate rats on the same diet conditions, expression of the transporters of glucose and ketones (glucose transporter 1 (GLUT1) and monocarboxylic acid transporter (MCT1)) was measured in brain microvessel preparations. Compared to controls, uptake of (11)C-AcAc increased more than 2-fold while on the KD or after 48 hours F (P < 0.05). Similar trends were observed for (18)FDG uptake with a 1.9-2.6 times increase on the KD and F, respectively (P < 0.05). Compared to controls, MCT1 expression increased 2-fold on the KD (P < 0.05) but did not change during F. No significant difference was observed across groups for GLUT1 expression. Significant differences across the three groups were observed for plasma beta-hydroxybutyrate (beta-HB), AcAc, glucose, triglycerides, glycerol, and cholesterol (P < 0.05), but no significant differences were observed for free fatty acids, insulin, or lactate. Although the mechanism by which mild ketonemia increases brain glucose uptake remains unclear, the KD clearly increased both the blood-brain barrier expression of MCT1 and stimulated brain (11)C-AcAc uptake. The present dual-tracer positron emission tomography approach may be particularly interesting in neurodegenerative pathologies such as Alzheimer's disease where brain energy supply appears to decline critically.

  11. Reversal of cerebral glucose hypometabolism on positron emission tomography with electroconvulsive therapy in an elderly patient with a psychotic episode.

    PubMed

    Hassamal, Sameer; Jolles, Paul; Pandurangi, Ananda

    2016-11-01

    AB, a 74-year-old Caucasian woman, was admitted for acute onset of psychosis, anxiety, and cognitive impairment. Pharmacotherapy was unsuccessful and the patient was referred for electroconvulsive therapy (ECT). Pre-ECT, (18) F-fluorodeoxyglucose-positron emission tomography (PET)/computed tomography showed extensive frontal, parietal, and temporal cortical hypometabolism suggestive of a neurodegenerative disease. After eight ECT sessions, the psychotic and anxiety symptoms as well as the cognitive impairment resolved. The rapid improvement in symptoms was more suggestive of a psychotic episode rather than dementia. Two days after the ECT course, (18) F-fluorodeoxyglucose-PET/computed tomography showed improvements in cerebral cortical hypometabolism, especially in the left parietal cortex, left temporal/occipital cortex. and bifrontal regions. At a follow-up visit 2 months after the ECT course, the psychotic episode was still in remission, and (18) F-fluorodeoxyglucose-PET/computed tomography continued to show improved cerebral cortical hypometabolism in these areas. This case illustrated the effect of ECT in reversing cerebral glucose hypometabolism on PET. The improvement in cerebral glucose hypometabolism may represent the neurophysiological mechanism of ECT in the treatment of a psychotic episode. Improved cerebral glucose hypometabolism was present 2 months post-ECT, which suggests that ECT caused sustained functional neural changes.

  12. [Study of regional cerebral glucose metabolism, in man, while awake or asleep, by positron emission tomography].

    PubMed

    Franck, G; Salmon, E; Poirrier, R; Sadzot, B; Franco, G

    1987-03-01

    Measurements of regional cerebral glucose uptake by the 18F-fluorodeoxyglucose technique (18FDG) and positron emission tomography (PET) along with polygraph recordings were made serially during relaxed wakefulness and different stages of nocturnal sleep in two right-handed normal volunteers. During stage III-IV sleep, values declined diffusely in both hemispheric regions (-31%), thalamus (-33%), cerebellum (-33%) and brain stem (-25%). During paradoxical sleep regional values increased diffusely compared with slow wave sleep. Compared to wakefulness, regional metabolic values seemed to increase but the results were more variable from one volunteer to the other. These preliminary data indicate important regional alterations in cerebral metabolism between sleep states.

  13. Molecular imaging of prostate cancer with 18F-fluorodeoxyglucose PET

    PubMed Central

    Jadvar, Hossein

    2009-01-01

    Prostate cancer poses a major public health problem, particularly in the US and Europe, where it constitutes the most common type of malignancy among men, excluding nonmelanoma skin cancers. The disease is characterized by a wide spectrum of biological and clinical phenotypes, and its evaluation by imaging remains a challenge in view of this heterogeneity. Imaging in prostate cancer can be used in the initial diagnosis of the primary tumor, to determine the occurrence and extent of any extracapsular spread, for guidance in delivery and evaluation of local therapy in organ-confined disease, in locoregional lymph node staging, to detect locally recurrent and metastatic disease in biochemical relapse, to predict and assess tumor response to systemic therapy or salvage therapy, and in disease prognostication (in terms of the length of time taken for castrate-sensitive disease to become refractory to hormones and overall patient survival). Evidence from animal-based translational and human-based clinical studies points to a potential and emerging role for PET, using 18F-fluorodeoxyglucose as a radiotracer, in the imaging evaluation of prostate cancer. PMID:19434102

  14. Tumor Delineation and Quantitative Assessment of Glucose Metabolic Rate within Histologic Subtypes of Non-Small Cell Lung Cancer by Using Dynamic (18)F Fluorodeoxyglucose PET.

    PubMed

    Meijer, Tineke W H; de Geus-Oei, Lioe-Fee; Visser, Eric P; Oyen, Wim J G; Looijen-Salamon, Monika G; Visvikis, Dimitris; Verhagen, Ad F T M; Bussink, Johan; Vriens, Dennis

    2016-11-15

    Purpose To assess whether dynamic fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET) has added value over static (18)F-FDG PET for tumor delineation in non-small cell lung cancer (NSCLC) radiation therapy planning by using pathology volumes as the reference standard and to compare pharmacokinetic rate constants of (18)F-FDG metabolism, including regional variation, between NSCLC histologic subtypes. Materials and Methods The study was approved by the institutional review board. Patients gave written informed consent. In this prospective observational study, 1-hour dynamic (18)F-FDG PET/computed tomographic examinations were performed in 35 patients (36 resectable NSCLCs) between 2009 and 2014. Static and parametric images of glucose metabolic rate were obtained to determine lesion volumes by using three delineation strategies. Pathology volume was calculated from three orthogonal dimensions (n = 32). Whole tumor and regional rate constants and blood volume fraction (VB) were computed by using compartment modeling. Results Pathology volumes were larger than PET volumes (median difference, 8.7-25.2 cm(3); Wilcoxon signed rank test, P < .001). Static fuzzy locally adaptive Bayesian (FLAB) volumes corresponded best with pathology volumes (intraclass correlation coefficient, 0.72; P < .001). Bland-Altman analyses showed the highest precision and accuracy for static FLAB volumes. Glucose metabolic rate and (18)F-FDG phosphorylation rate were higher in squamous cell carcinoma (SCC) than in adenocarcinoma (AC), whereas VB was lower (Mann-Whitney U test or t test, P = .003, P = .036, and P = .019, respectively). Glucose metabolic rate, (18)F-FDG phosphorylation rate, and VB were less heterogeneous in AC than in SCC (Friedman analysis of variance). Conclusion Parametric images are not superior to static images for NSCLC delineation. FLAB-based segmentation on static (18)F-FDG PET images is in best agreement with pathology volume and could be

  15. Newer positron emission tomography radiopharmaceuticals for radiotherapy planning: an overview

    PubMed Central

    Mukherjee, Anirban

    2016-01-01

    Positron emission tomography-computed tomography (PET-CT) has changed cancer imaging in the last decade, for better. It can be employed for radiation treatment planning of different cancers with improved accuracy and outcomes as compared to conventional imaging methods. 18F-fluorodeoxyglucose remains the most widely used though relatively non-specific cancer imaging PET tracer. A wide array of newer PET radiopharmaceuticals has been developed for targeted imaging of different cancers. PET-CT with such new PET radiopharmaceuticals has also been used for radiotherapy planning with encouraging results. In the present review we have briefly outlined the role of PET-CT with newer radiopharmaceuticals for radiotherapy planning and briefly reviewed the available literature in this regard. PMID:26904575

  16. Long-term quality assurance of [18F]-fluorodeoxyglucose (FDG) manufacturing

    PubMed Central

    Gaspar, Ludovit; Reich, Michal; Kassai, Zoltan; Macasek, Fedor; Rodrigo, Luis; Kruzliak, Peter; Kovac, Peter

    2016-01-01

    Nine years of experience with 2286 commercial synthesis allowed us to deliver comprehensive information on the quality of 18F-FDG production. Semi-automated FDG production line using Cyclone 18/9 machine (IBA Belgium), TRACERLab MXFDG synthesiser (GE Health, USA) using alkalic hydrolysis, grade “A” isolator with dispensing robotic unit (Tema Sinergie, Italy), and automatic control system under GAMP5 (minus2, Slovakia) was assessed by TQM tools as highly reliable aseptic production line, fully compliant with Good Manufacturing Practice and just-in-time delivery of FDG radiopharmaceutical. Fluoride-18 is received in steady yield and of very high radioactive purity. Synthesis yields exhibited high variance connected probably with quality of disposable cassettes and chemicals sets. Most performance non-conformities within the manufacturing cycle occur at mechanical nodes of dispensing unit. The long-term monitoring of 2286 commercial synthesis indicated high reliability of automatic synthesizers. Shewhart chart and ANOVA analysis showed that minor non-compliances occurred were mostly caused by the declinations of less experienced staff from standard operation procedures, and also by quality of automatic cassettes. Only 15 syntheses were found unfinished and in 4 cases the product was out-of-specification of European Pharmacopoeia. Most vulnerable step of manufacturing was dispensing and filling in grade “A” isolator. Its cleanliness and sterility was fully controlled under the investigated period by applying hydrogen peroxide vapours (VHP). Our experience with quality assurance in the production of [18F]-fluorodeoxyglucose (FDG) at production facility of BIONT based on TRACERlab MXFDG production module can be used for bench-marking of the emerging manufacturing and automated manufacturing systems. PMID:27508102

  17. Long-term quality assurance of [(18)F]-fluorodeoxyglucose (FDG) manufacturing.

    PubMed

    Gaspar, Ludovit; Reich, Michal; Kassai, Zoltan; Macasek, Fedor; Rodrigo, Luis; Kruzliak, Peter; Kovac, Peter

    2016-01-01

    Nine years of experience with 2286 commercial synthesis allowed us to deliver comprehensive information on the quality of (18)F-FDG production. Semi-automated FDG production line using Cyclone 18/9 machine (IBA Belgium), TRACERLab MXFDG synthesiser (GE Health, USA) using alkalic hydrolysis, grade "A" isolator with dispensing robotic unit (Tema Sinergie, Italy), and automatic control system under GAMP5 (minus2, Slovakia) was assessed by TQM tools as highly reliable aseptic production line, fully compliant with Good Manufacturing Practice and just-in-time delivery of FDG radiopharmaceutical. Fluoride-18 is received in steady yield and of very high radioactive purity. Synthesis yields exhibited high variance connected probably with quality of disposable cassettes and chemicals sets. Most performance non-conformities within the manufacturing cycle occur at mechanical nodes of dispensing unit. The long-term monitoring of 2286 commercial synthesis indicated high reliability of automatic synthesizers. Shewhart chart and ANOVA analysis showed that minor non-compliances occurred were mostly caused by the declinations of less experienced staff from standard operation procedures, and also by quality of automatic cassettes. Only 15 syntheses were found unfinished and in 4 cases the product was out-of-specification of European Pharmacopoeia. Most vulnerable step of manufacturing was dispensing and filling in grade "A" isolator. Its cleanliness and sterility was fully controlled under the investigated period by applying hydrogen peroxide vapours (VHP). Our experience with quality assurance in the production of [(18)F]-fluorodeoxyglucose (FDG) at production facility of BIONT based on TRACERlab MXFDG production module can be used for bench-marking of the emerging manufacturing and automated manufacturing systems.

  18. 18F-Fluorodeoxyglycosylamines: Maillard reaction of 18F-fluorodeoxyglucose with biological amines.

    PubMed

    Baranwal, Aparna; Patel, Himika H; Mukherjee, Jogeshwar

    2014-02-01

    The Maillard reaction of sugars and amines resulting in the formation of glycosylamines and Amadori products is of biological significance, for drug delivery, role in central nervous system, and other potential applications. We have examined the interaction of (18) F-fluorodeoxyglucose ((18) F-FDG) with biological amines to study the formation of (18) F-fluorodeoxyglycosylamines ((18) F-FDGly). Respective amines N-allyl-2-aminomethylpyrrolidine (NAP) and 2-(4'-aminophenyl)-6-hydroxybenzothiazole (PIB precursor) were mixed with FDG to provide glycosylamines, FDGNAP and FDGBTA. Radiosynthesis using (18) F-FDG (2-5 mCi) was carried out to provide (18) F-FDGNAP and (18) F-FDGBTA. Binding of FDGBTA and (18) F-FDGBTA was evaluated in human brain sections of Alzheimer's disease (AD) patients and control subjects using autoradiography. Both FDGNAP and FDGBTA were isolated as stable products. Kinetics of (18) F-FDGNAP reaction indicated a significant product at 4 h (63% radiochemical yield). (18) F-FDGBTA was prepared in 57% yield. Preliminary studies of FDGBTA showed displacement of (3) H-PIB (reduced by 80%), and (18) F-FDGBTA indicated selective binding to Aβ-amyloid plaques present in postmortem AD human brain, with a gray matter ratio of 3 between the AD patients and control subjects. We have demonstrated that (18) F-FDG couples with amines under mild conditions to form (18) F-FDGly in a manner similar to click chemistry. Although these amine derivatives are stable in vitro, stability in vivo and selective binding is under investigation.

  19. The effect of nifedipine on myocardial perfusion and metabolism in systemic sclerosis. A positron emission tomographic study

    SciTech Connect

    Duboc, D.; Kahan, A.; Maziere, B.; Loc'h, C.; Crouzel, C.; Menkes, C.J.; Amor, B.; Strauch, G.; Guerin, F.; Syrota, A. )

    1991-02-01

    We assessed the effect of nifedipine on myocardial perfusion and metabolism in 9 patients with systemic sclerosis, using positron emission tomography with a perfusion tracer (potassium-38) and a metabolic tracer (18F-fluorodeoxyglucose (18FDG)). Nifedipine, 20 mg 3 times daily for 1 week, induced a significant increase in 38K myocardial uptake, a significant decrease in 18FDG myocardial uptake, and a significant increase in the myocardial 38K: 18FDG ratio. These results indicate that the increase in myocardial perfusion is associated with modifications in myocardial energy metabolism, which probably result from a beneficial anti-ischemic effect of nifedipine in patients with systemic sclerosis.

  20. Pulmonary artery intimal sarcoma: the role of ¹⁸F-fluorodeoxyglucose positron emission tomography in monitoring response to treatment.

    PubMed

    Ote, Enrique Leonardo P; Oriuchi, Noboru; Miyashita, Go; Paudyal, Bishnuhari; Ishikita, Tomohiro; Arisaka, Yukiko; Higuchi, Tetsuya; Hirato, Junko; Endo, Keigo

    2011-05-01

    We report the case of 58-year-old man with pulmonary artery intimal sarcoma. He initially presented with cough, right-sided chest pain, and shortness of breath. Although the diagnosis of pulmonary embolism had been considered, chest radiograph and pulmonary perfusion scintigraphy showed a mass in the right hilum and no perfusion in the right lung. (18)F-fluorodeoxyglucose positron emission computed tomography (FDGPET) showed increased FDG uptake in the mass obstructing the right pulmonary artery. Fine-needle biopsy revealed a pathological diagnosis of pulmonary artery intimal sarcoma. The patient was successfully treated with radiotherapy and adjuvant chemotherapy. FDG-PET was used for monitoring the response to therapy.

  1. pO polarography, contrast enhanced color duplex sonography (CDS), [18F] fluoromisonidazole and [18F] fluorodeoxyglucose positron emission tomography: validated methods for the evaluation of therapy-relevant tumor oxygenation or only bricks in the puzzle of tumor hypoxia?

    PubMed Central

    Gagel, Bernd; Piroth, Marc; Pinkawa, Michael; Reinartz, Patrick; Zimny, Michael; Kaiser, Hans J; Stanzel, Sven; Asadpour, Branka; Demirel, Cengiz; Hamacher, Kurt; Coenen, Heinz H; Scholbach, Thomas; Maneschi, Payam; DiMartino, Ercole; Eble, Michael J

    2007-01-01

    Background The present study was conducted to analyze the value of ([18F] fluoromisonidazole (FMISO) and [18F]-2-fluoro-2'-deoxyglucose (FDG) PET as well as color pixel density (CPD) and tumor perfusion (TP) assessed by color duplex sonography (CDS) for determination of therapeutic relevant hypoxia. As a standard for measuring tissue oxygenation in human tumors, the invasive, computerized polarographic needle electrode system (pO2 histography) was used for comparing the different non invasive measurements. Methods Until now a total of 38 Patients with malignancies of the head and neck were examined. Tumor tissue pO2 was measured using a pO2-histograph. The needle electrode was placed CT-controlled in the tumor without general or local anesthesia. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO2 readings, with values ≤ 2.5, ≤ 5.0 and ≤ 10.0 mmHg, as well as mean and median pO2 were stated. FMISO PET consisted of one static scan of the relevant region, performed 120 min after intravenous administration. FMISO tumor to muscle ratios (FMISOT/M) and tumor to blood ratios (FMISOT/B) were calculated. FDG PET of the lymph node metastases was performed 71 ± 17 min after intravenous administration. To visualize as many vessels as possible by CDS, a contrast enhancer (Levovist®, Schering Corp., Germany) was administered. Color pixel density (CPD) was defined as the ratio of colored to grey pixels in a region of interest. From CDS signals two parameters were extracted: color hue – defining velocity (v) and color area – defining perfused area (A). Signal intensity as a measure of tissue perfusion (TP) was quantified as follows: TP = vmean × Amean. Results In order to investigate the degree of linear association, we calculated the Pearson correlation coefficient. Slight (|r| > 0.4) to moderate (|r| > 0.6) correlation was found between the parameters of pO2 polarography (pO2 readings with values ≤ 2.5, ≤ 5.0 and ≤ 10.0 mmHg, as well as median pO2), CPD and FMISOT/M. Only a slight correlation between TP and the fraction of pO2 values ≤ 10.0 mmHg, median and mean pO2 could be detected. After exclusion of four outliers the absolute values of the Pearson correlation coefficients increased clearly. There was no relevant association between mean or maximum FDG uptake and the different polarographic- as well as the CDS parameters. Conclusion CDS and FMISO PET represent different approaches for estimation of therapy relevant tumor hypoxia. Each of these approaches is methodologically limited, making evaluation of clinical potential in prospective studies necessary. PMID:17598907

  2. Autoimmune lymphoproliferative syndrome and non-Hodgkin lymphoma: what 18F-fluorodeoxyglucose positron emission tomography/computed tomography can do in the management of these patients? Suggestions from a case report.

    PubMed

    Cistaro, A; Pazè, F; Durando, S; Cogoni, M; Faletti, R; Vesco, S; Vallero, S; Quartuccio, N; Treglia, G; Ramenghi, U

    2014-01-01

    A young patient with undefined autoimmune lymphoproliferative syndrome (ALPS-U) and low back pain underwent a CT and MRI study that showed enhancing vertebral lesions, some pulmonary nodules and diffuse latero-cervical lymphadenopathy. A (18)F-FDG-PET/CT scan showed many areas of intense (18)F-FDG uptake in multiple vertebrae, in some ribs, in the sacrum, in the liver, in both lungs, in multiple lymph nodes spread in the cervical, thoracic and abdominal chains. A bone marrow biopsy showed a "lymphomatoid granulomatosis", a rare variant of B-cell non-Hodgkin lymphoma (NHL). After the treatment, the (18)F-FDG-PET/CT scan showed a complete metabolic response.

  3. Utility of [18F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG PET/CT) in the Initial Staging and Response Assessment of Locally Advanced Breast Cancer Patients Receiving Neoadjuvant Chemotherapy.

    PubMed

    Hulikal, Narendra; Gajjala, Sivanath Reddy; Kalawat, Teck Chand; Kottu, Radhika; Amancharla Yadagiri, Lakshmi

    2015-12-01

    In India up to 50 % of breast cancer patients still present as locally advanced breast cancer (LABC). The conventional methods of metastatic work up include physical examination, bone scan, chest & abdominal imaging, and biochemical tests. It is likely that the conventional staging underestimates the extent of initial spread and there is a need for more sophisticated staging procedure. The PET/CT can detect extra-axillary and occult distant metastases and also aid in predicting response to chemotherapy at an early point in time. To evaluate the utility of FDG PET/CT in initial staging and response assessment of patients with LABC receiving NACT. A prospective study of all biopsy confirmed female patients diagnosed with LABC receiving NACT from April 2013 to May 2014. The conventional work up included serum chemistry, CECT chest and abdomen and bone scan. A baseline whole body PET/CT was done in all patients. A repeat staging evaluation and a whole body PET/CT was done after 2/3rd cycle of NACT in non-responders and after 3/4 cycles in clinical responders. The histopathology report of the operative specimen was used to document the pathological response. The FDG PET/CT reported distant metastases in 11 of 38 patients, where as conventional imaging revealed metastases in only 6. Almost all the distant lesions detected by conventional imaging were detected with PET/CT, which showed additional sites of metastasis in 3 patients. In 2 patients, PET/CT detected osteolytic bone metastasis which were not detected by bone scan. In 5 patients PET CT detected N3 disease which were missed on conventional imaging. A total of 14 patients had second PET/CT done to assess the response to NACT and 11 patients underwent surgery. Two patients had complete pathological response. Of these 1 patient had complete metabolic and morphologic response and other had complete metabolic and partial morphologic response on second PET/CT scan. The 18 FDG PET/CT can detect more number of metastasis as well as additional sites of metastasis compared to conventional methods. The response assessment resulted in change of treatment regimen in 14 % of patients.

  4. Value of sequential 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in prediction of the overall survival of esophageal cancer patients treated with chemoradiotherapy.

    PubMed

    Li, Yimin; Lin, Qin; Luo, Zuoming; Zhao, Long; Zhu, Luchao; Sun, Long; Wu, Hua

    2015-01-01

    This study is to investigate the value of the metabolic parameters measured by sequential FDG PET/CT in predicting the overall survival of patients with esophageal squamous cell carcinoma (ESCC). A total of 160 patients who were newly diagnosed as ESCC patients and treated with chemoradiotherapy were included in this study. The FDG PET/CT was carried out prior to radiotherapy (PET1), when the cumulative dose of radiotherapy reached 50 Gy (PET2), at the end of radiotherapy (PET3) and 1 month after radiotherapy (PET4). The max of the standard uptake value (SUVmax) of the primary tumor, the metabolic tumor volume (MTV) and the total lesion glycolisis (TLG) prior to treatment were measured. The correlation of the measured parameters and the derived parameters of SUVmax with the overall survival was analyzed. The relatively reduced percentage of the SUVmax of PET3 and PET4 to the SUVmax of PET1 and PET2, had predictive value for the overall survival. The area under researcher operation curve (ROC) was between 0.62 and 0.73 (P < 0.01). The MTV and TLG prior to treatment might be used to predict the overall survival, and the area under ROC were both 0.69 (P < 0.001). Sequential FDG PET/CT scanning is useful to predict the overall survival of chemoradiotherapy for ESCC. The metabolic parameters and the derived parameters of FDG PET/CT have predictive values for overall survival.

  5. Value of sequential 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in prediction of the overall survival of esophageal cancer patients treated with chemoradiotherapy

    PubMed Central

    Li, Yimin; Lin, Qin; Luo, Zuoming; Zhao, Long; Zhu, Luchao; Sun, Long; Wu, Hua

    2015-01-01

    This study is to investigate the value of the metabolic parameters measured by sequential FDG PET/CT in predicting the overall survival of patients with esophageal squamous cell carcinoma (ESCC). A total of 160 patients who were newly diagnosed as ESCC patients and treated with chemoradiotherapy were included in this study. The FDG PET/CT was carried out prior to radiotherapy (PET1), when the cumulative dose of radiotherapy reached 50 Gy (PET2), at the end of radiotherapy (PET3) and 1 month after radiotherapy (PET4). The max of the standard uptake value (SUVmax) of the primary tumor, the metabolic tumor volume (MTV) and the total lesion glycolisis (TLG) prior to treatment were measured. The correlation of the measured parameters and the derived parameters of SUVmax with the overall survival was analyzed. The relatively reduced percentage of the SUVmax of PET3 and PET4 to the SUVmax of PET1 and PET2, had predictive value for the overall survival. The area under researcher operation curve (ROC) was between 0.62 and 0.73 (P < 0.01). The MTV and TLG prior to treatment might be used to predict the overall survival, and the area under ROC were both 0.69 (P < 0.001). Sequential FDG PET/CT scanning is useful to predict the overall survival of chemoradiotherapy for ESCC. The metabolic parameters and the derived parameters of FDG PET/CT have predictive values for overall survival. PMID:26379889

  6. Differentiation between Polymyalgia Rheumatica (PMR) and Elderly-Onset Rheumatoid Arthritis Using 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: Is Enthesitis a New Pathological Lesion in PMR?

    PubMed Central

    Wakura, Daisuke; Kotani, Takuya; Takeuchi, Tohru; Komori, Tsuyoshi; Yoshida, Shuzo; Makino, Shigeki; Hanafusa, Toshiaki

    2016-01-01

    Background It is difficult to differentiate polymyalgia rheumatica (PMR) from elderly-onset rheumatoid arthritis (EORA) in clinical practice. We compared FDG-PET/CT findings between patients with PMR and those with EORA and extracted factors useful for differentiating the two disorders. Methods We compared abnormal FDG accumulation sites and maximum standardized uptake value (SUVmax) between 15 patients with PMR and 7 with EORA in whom FDG-PET/CT was performed. Results The proportion of patients in the PMR group with abnormal FDG accumulation at the following 9 sites on FDG-PET/CT was significantly higher than that in the EORA group: periarticular region of the scapulohumeral joint, enthesis of the pectineus muscle, vicinity of the enthesis of the rectus femoris muscle, lateral side of the greater trochanter, ischial tuberosity, hip joint, spinous process of the lower cervical vertebra, intervertebral joint of the lumbar vertebra, and spinous process of the lumbar vertebra. The PET/CT score was evaluated at 9 sites consisting of the abovementioned sites. The median score in the PMR group was 8, which was significantly higher than that of 0 in the EORA group (P = 0.0003). ROC curve analysis was performed with the PET/CT scores, and a score of 5 was shown to maximize the area under the ROC curve (sensitivity: 86.7%, specificity: 86.7%). Conclusions FDG-PET/CT is useful for differentiating PMR from EORA. In patients with PMR, abnormal FDG accumulation was observed at the entheses, suggesting the presence of enthesitis in addition to bursitis and synovitis. PMID:27384410

  7. Positron emission tomography in generalized seizures

    SciTech Connect

    Theodore, W.H.; Brooks, R.; Margolin, R.; Patronas, N.; Sato, S.; Porter, R.J.; Mansi, L.; Bairamian, D.; DiChiro, G.

    1985-05-01

    The authors used /sup 18/F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to study nine patients with clinical absence or generalized seizures. One patient had only absence seizures, two had only generalized tonic-clonic seizures, and six had both seizure types. Interictal scans in eight failed to reveal focal or lateralized hypometabolism. No apparent abnormalities were noted. Two patients had PET scans after isotope injection during hyperventilation-induced generalized spike-wave discharges. Diffusely increased metabolic rates were found in one compared with an interictal scan, and in another compared with control values. Another patient had FDG injected during absence status: EEG showed generalized spike-wave discharges (during which she was unresponsive) intermixed with slow activity accompanied by confusion. Metabolic rates were decreased, compared with the interictal scan, throughout both cortical and subcortical structures. Interictal PET did not detect specific anatomic regions responsible for absence seizure onset in any patient, but the results of the ictal scans did suggest that pathophysiologic differences exist between absence status and single absence attacks.

  8. Regional Lymph Node Uptake of [18F]Fluorodeoxyglucose After Definitive Chemoradiation Therapy Predicts Local-Regional Failure of Locally Advanced Non-Small Cell Lung Cancer: Results of ACRIN 6668/RTOG 0235

    PubMed Central

    Markovina, Stephanie; Duan, Fenghai; Snyder, Bradley S.; Siegel, Barry A.; Machtay, Mitchell; Bradley, Jeffrey

    2015-01-01

    Purpose/Objective(s) ACRIN 6668/RTOG 0235 demonstrated that standardized uptake value (SUV) on post-treatment [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) correlates with survival in locally advanced non-small cell lung cancer (NSCLC). This secondary analysis determines if SUV of regional lymph nodes (RLNs) on post-treatment FDG-PET correlates with patient outcomes. Methods and Materials Included for analysis were patients treated with concurrent chemoradiation therapy using radiation doses ≥60 Gy, with identifiable FDG-avid RLNs (distinct from primary tumor) on pre-treatment FDG-PET, and post-treatment FDG-PET data. ACRIN Core Laboratory SUV measurements were used. Event time was calculated from the date of post-treatment FDG-PET. Local-regional failure was defined as failure within the treated RT volume and reported by the treating institution. Statistical analyses included Wilcoxon signed-rank test, Kaplan-Meier curves (log rank test), and Cox proportional hazards regression modeling. Results Of 234 trial-eligible patients, 139 (59%) had uptake in both primary tumor and RLNs on pre-treatment FDG-PET, and had SUV data from post-treatment FDG-PET. Maximum SUV was greater for primary tumor than for RLNs before treatment (p<0.001), but not different post-treatment (p=0.320). Post-treatment SUV of RLNs was not associated with overall survival. However, elevated post-treatment SUV of RLNs, both the absolute value and the percent residual activity compared to the pre-treatment SUV, were associated with inferior local-regional control (p<0.001). Conclusions High residual metabolic activity in RLNs on post-treatment FDG-PET is associated with worse local-regional control. Based on these data, future trials evaluating a radiotherapy boost should consider inclusion of both primary tumor and FDG-avid RLNs in the boost volume to maximize local-regional control. PMID:26461002

  9. 18F-fluorodeoxyglucose (FDG) PET/CT after two cycles of neoadjuvant therapy may predict response in HER2-negative, but not in HER2-positive breast cancer.

    PubMed

    Cheng, Jingyi; Wang, Yujie; Mo, Miao; Bao, Xiao; Zhang, Yingjian; Liu, Guangyu; Zhang, Jun; Geng, Daoying

    2015-10-06

    The aim of this prospective study was to assess the ability of 18F-fluorodeoxyglucose ((18)FDG) positron emission tomography/computed tomography (PET/CT) scanning to predict pathological complete response (pCR) in breast cancer, and to investigate whether timing of the scan and trastuzumab treatment influence the accuracy of pCR prediction in human epidermal growth factor receptor 2 (HER2) positive breast cancer patients. We treated 81 locally advanced breast cancer patients with four cycles of neoadjuvant chemotherapy (NAC). HER2-negative breast cancer patients received NAC alone, while HER2-positive breast cancer patients received NAC plus trastuzumab. (18)FDG PET/CT scans were scheduled at baseline and after the second cycle of NAC. Axillary lymph node (ALN) dissection was performed after the last cycle of neoadjuvant therapy. Relative changes in standardized uptake values (SUV) between the two PET/CT scans (ΔSUV) in primary tumors and ALN metastases were calculated. There were 75 patients with 150 PET/CT scans in the final analysis, including 41 HER2-negative and 34 HER2-positive cases. In the HER2-negative group, the ΔSUV predicted overall and ALN pCR; the receiver operating characteristics-areas under curve (ROC-AUC) were 0.87 and 0.80 (P = 0.0014 and 0.031, respectively) and the negative predictive values were 94% and 89% respectively. However, in the HER2-positive group, ΔSUV could predict neither overall nor ALN pCR; the ROC-AUCs were only 0.56 and 0.53, with P = 0.53 and 0.84, respectively. Hence, the ΔSUV after two cycles of neoadjuvant therapy could predict pCR in HER2-negative patients treated with NAC alone, but not in HER2-positive patients treated with NAC plus trastuzumab.

  10. Imaging in breast cancer: Single-photon computed tomography and positron-emission tomography

    PubMed Central

    Bénard, François; Turcotte, Éric

    2005-01-01

    Although mammography remains a key imaging method for the early detection and screening of breast cancer, the overall accuracy of this test remains low. Several radiopharmaceuticals have been proposed as adjunct imaging methods to characterize breast masses by single-photon-emission computed tomography (SPECT) and positron-emission tomography (PET). Useful in characterizing indeterminate palpable masses and in the detection of axillary metastases, these techniques are insufficiently sensitive to detect subcentimetric tumor deposits. Their role in staging nodal involvement of the axillary areas therefore currently remains limited. Several enzymes and receptors have been targeted for imaging breast cancers with PET. [18F]Fluorodeoxyglucose is particularly useful in the detection and staging of recurrent breast cancer and in assessing the response to chemotherapy. Several other ligands targeting proliferative activity, protein synthesis, and hormone and cell-membrane receptors may complement this approach by providing unique information about biological characteristics of breast cancer across primary and metastatic tumor sites. PMID:15987467

  11. Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

    SciTech Connect

    Wu, J.C.; Hagman, J.; Buchsbaum, M.S.; Blinder, B.; Derrfler, M.; Tai, W.Y.; Hazlett, E.; Sicotte, N. )

    1990-03-01

    Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion that bulimia is a diagnostic grouping distinct from these disorders.

  12. Methods and applications of positron-based medical imaging

    NASA Astrophysics Data System (ADS)

    Herzog, H.

    2007-02-01

    Positron emission tomography (PET) is a diagnostic imaging method to examine metabolic functions and their disorders. Dedicated ring systems of scintillation detectors measure the 511 keV γ-radiation produced in the course of the positron emission from radiolabelled metabolically active molecules. A great number of radiopharmaceuticals labelled with 11C, 13N, 15O, or 18F positron emitters have been applied both for research and clinical purposes in neurology, cardiology and oncology. The recent success of PET with rapidly increasing installations is mainly based on the use of [ 18F]fluorodeoxyglucose (FDG) in oncology where it is most useful to localize primary tumours and their metastases.

  13. SU-E-I-85: Exploring the 18F-Fluorodeoxyglucose PET Characteristics in Staging of Esophageal Squamous Cell Carcinoma

    SciTech Connect

    Ma, C; Yin, Y

    2014-06-01

    Purpose: The aim of this study was to explore the characteristics derived from 18F-fluorodeoxyglucose (18F-FDG) PET image and assess its capacity in staging of esophageal squamous cell carcinoma (ESCC). Methods: 26 patients with newly diagnosed ESCC who underwent 18F-FDG PET scan were included in this study. Different image-derived indices including the standardized uptake value (SUV), gross tumor length, texture features and shape feature were considered. Taken the histopathologic examination as the gold standard, the extracted capacities of indices in staging of ESCC were assessed by Kruskal-Wallis test and Mann-Whitney test. Specificity and sensitivity for each of the studied parameters were derived using receiver-operating characteristic curves. Results: 18F-FDG SUVmax and SUVmean showed statistically significant capability in AJCC and TNM stages. Texture features such as ENT and CORR were significant factors for N stages(p=0.040, p=0.029). Both FDG PET Longitudinal length and shape feature Eccentricity (EC) (p≤0.010) provided powerful stratification in the primary ESCC AJCC and TNM stages than SUV and texture features. Receiver-operating-characteristic curve analysis showed that tumor textural analysis can capability M stages with higher sensitivity than SUV measurement but lower in T and N stages. Conclusion: The 18F-FDG image-derived characteristics of SUV, textural features and shape feature allow for good stratification AJCC and TNM stage in ESCC patients.

  14. Comparison of {sup 18}F-Fluorothymidine and {sup 18}F-Fluorodeoxyglucose PET/CT in Delineating Gross Tumor Volume by Optimal Threshold in Patients With Squamous Cell Carcinoma of Thoracic Esophagus

    SciTech Connect

    Han Dali; Yu Jinming; Yu Yonghua; Zhang Guifang; Zhong Xiaojun; Lu Jie; Yin Yong; Fu Zheng; Mu Dianbin; Zhang Baijiang; He Wei; Huo Zhijun; Liu Xijun; Kong Lei; Zhao Shuqiang; Sun Xiangyu

    2010-03-15

    Purpose: To determine the optimal method of using {sup 18}F-fluorothymidine (FLT) positron emission tomography (PET)/computed tomography (CT) simulation to delineate the gross tumor volume (GTV) in esophageal squamous cell carcinoma verified by pathologic examination and compare the results with those using {sup 18}F-fluorodeoxyglucose (FDG) PET/CT. Methods and Materials: A total of 22 patients were enrolled and underwent both FLT and FDG PET/CT. The GTVs with biologic information were delineated using seven different methods in FLT PET/CT and three different methods in FDG PET/CT. The results were compared with the pathologic gross tumor length, and the optimal threshold was obtained. Next, we compared the simulation plans using the optimal threshold of FLT and FDG PET/CT. The radiation dose was prescribed as 60 Gy in 30 fractions with a precise radiotherapy technique. Results: The mean +- standard deviation pathologic gross tumor length was 4.94 +- 2.21 cm. On FLT PET/CT, the length of the standardized uptake value 1.4 was 4.91 +- 2.43 cm. On FDG PET/CT, the length of the standardized uptake value 2.5 was 5.10 +- 2.18 cm, both of which seemed more approximate to the pathologic gross tumor length. The differences in the bilateral lung volume receiving >=20 Gy, heart volume receiving >=40 Gy, and the maximal dose received by spinal cord between FLT and FDG were not significant. However, the values for mean lung dose, bilateral lung volume receiving >=5, >=10, >=30, >=40, and >=50 Gy, mean heart dose, and heart volume receiving >=30 Gy using FLT PET/CT-based planning were significant lower than those using FDG PET/CT. Conclusion: A standardized uptake value cutoff of 1.4 on FLT PET/CT and one of 2.5 on FDG PET/CT provided the closest estimation of GTV length. Finally, FLT PET/CT-based treatment planning provided potential benefits to the lungs and heart.

  15. [{sup 18}F]fluorodeoxyglucose Uptake Patterns in Lung Before Radiotherapy Identify Areas More Susceptible to Radiation-Induced Lung Toxicity in Non-Small-Cell Lung Cancer Patients

    SciTech Connect

    Petit, Steven F.; Elmpt, Wouter J.C. van; Oberije, Cary J.G.; Vegt, Erik; Dingemans, Anne-Marie C.; Lambin, Philippe; Dekker, Andre L.A.J.; De Ruysscher, Dirk

    2011-11-01

    Purpose: Our hypothesis was that pretreatment inflammation in the lung makes pulmonary tissue more susceptible to radiation damage. The relationship between pretreatment [{sup 18}F]fluorodeoxyglucose ([{sup 18}F]FDG) uptake in the lungs (as a surrogate for inflammation) and the delivered radiation dose and radiation-induced lung toxicity (RILT) was investigated. Methods and Materials: We retrospectively studied a prospectively obtained cohort of 101 non-small-cell lung cancer patients treated with (chemo)radiation therapy (RT). [{sup 18}F]FDG-positron emission tomography-computed tomography (PET-CT) scans used for treatment planning were studied. Different parameters were used to describe [{sup 18}F]FDG uptake patterns in the lungs, excluding clinical target volumes, and the interaction with radiation dose. An increase in the dyspnea grade of 1 (Common Terminology Criteria for Adverse Events version 3.0) or more points compared to the pre-RT score was used as an endpoint for analysis of RILT. The effect of [{sup 18}F]FDG and CT-based variables, dose, and other patient or treatment characteristics that effected RILT was studied using logistic regression. Results: Increased lung density and pretreatment [{sup 18}F]FDG uptake were related to RILT after RT with univariable logistic regression. The 95th percentile of the [{sup 18}F]FDG uptake in the lungs remained significant in multivariable logistic regression (p = 0.016; odds ratio [OR] = 4.3), together with age (p = 0.029; OR = 1.06), and a pre-RT dyspnea score of {>=}1 (p = 0.005; OR = 0.20). Significant interaction effects were demonstrated among the 80th, 90th, and 95th percentiles and the relative lung volume receiving more than 2 and 5 Gy. Conclusions: The risk of RILT increased with the 95th percentile of the [{sup 18}F]FDG uptake in the lungs, excluding clinical tumor volume (OR = 4.3). The effect became more pronounced as the fraction of the 5%, 10%, and 20% highest standardized uptake value voxels that

  16. Kinetic Modeling and Graphical Analysis of 18F-Fluoromethylcholine (FCho), 18F-Fluoroethyltyrosine (FET) and 18F-Fluorodeoxyglucose (FDG) PET for the Fiscrimination between High-Grade Glioma and Radiation Necrosis in Rats

    PubMed Central

    Lybaert, Kelly; Moerman, Lieselotte; Descamps, Benedicte; Deblaere, Karel; Boterberg, Tom; Kalala, Jean-Pierre; Van den Broecke, Caroline; De Vos, Filip; Vanhove, Christian; Goethals, Ingeborg

    2016-01-01

    Background Discrimination between glioblastoma (GB) and radiation necrosis (RN) post-irradiation remains challenging but has a large impact on further treatment and prognosis. In this study, the uptake mechanisms of 18F-fluorodeoxyglucose (18F-FDG), 18F-fluoroethyltyrosine (18F-FET) and 18F-fluoromethylcholine (18F-FCho) positron emission tomography (PET) tracers were investigated in a F98 GB and RN rat model applying kinetic modeling (KM) and graphical analysis (GA) to clarify our previous results. Methods Dynamic 18F-FDG (GB n = 6 and RN n = 5), 18F-FET (GB n = 5 and RN n = 5) and 18F-FCho PET (GB n = 5 and RN n = 5) were acquired with continuous arterial blood sampling. Arterial input function (AIF) corrections, KM and GA were performed. Results The influx rate (Ki) of 18F-FDG uptake described by a 2-compartmental model (CM) or using Patlak GA, showed more trapping (k3) in GB (0.07 min-1) compared to RN (0.04 min-1) (p = 0.017). K1 of 18F-FET was significantly higher in GB (0.06 ml/ccm/min) compared to RN (0.02 ml/ccm/min), quantified using a 1-CM and Logan GA (p = 0.036). 18F-FCho was rapidly oxidized complicating data interpretation. Using a 1-CM and Logan GA no clear differences were found to discriminate GB from RN. Conclusions Based on our results we concluded that using KM and GA both 18F-FDG and 18F-FET were able to discriminate GB from RN. Using a 2-CM model more trapping of 18F-FDG was found in GB compared to RN. Secondly, the influx of 18F-FET was higher in GB compared to RN using a 1-CM model. Important correlations were found between SUV and kinetic or graphical measures for 18F-FDG and 18F-FET. 18F-FCho PET did not allow discrimination between GB and RN. PMID:27559736

  17. Functional imaging of the brain with/sup 18/F-fluorodeoxyglucose

    SciTech Connect

    Reivich, M; Greenberg, J; Alavi, A; Hand, P; Rintelmann, W; Rosenquist, A; Christman, D; Fowler, J; MacGregor, R; Wolf, A

    1980-01-01

    A techniques is reported by which it is possible to determine which regions of the human brain become functionally active in response to a specific stimulus. The method utilizes /sup 18/F-2-fluoro-2-deoxyglucose ((/sup 18/F)-FDG) administered as a bolus. (/sup 18/F)-FDG is used as a tracer for the exchange of glucose between plasma and brain and its phosphorylation. The subject is then scanned during administration of a physiologic stimulus by position emission tomography and the three-dimensional distribution of /sup 18/F activity in the brain determined. (ACR)

  18. Role of positron emission tomography in urological oncology.

    PubMed

    Rioja, Jorge; Rodríguez-Fraile, Macarena; Lima-Favaretto, Ricardo; Rincón-Mayans, Anibal; Peñuelas-Sánchez, Iván; Zudaire-Bergera, Juan Javier; Parra, Raul O

    2010-12-01

    • Positron emission tomography (PET) is a diagnostic tool using radiotracers to show changes in metabolic activities in tissues. We analysed the role of PET and PET/computed tomography (CT) in the diagnosis, staging, and follow-up of urological tumours. • A critical, non-structured review of the literature of the role of PET and PET/CT in urological oncology was conducted. • PET and PET/CT can play a role in the management of urological malignancies. For prostate cancer, the advances in radiotracers seems promising, with novel radiotracers yielding better diagnostic and staging results than 18F-fluorodeoxyglucose (18F-FDG). In kidney cancer, PET and PET/CT allow a proper diagnosis before the pathological examination of the surgical specimen. For testis cancer, PET and PET/CT have been shown to be useful in the management of seminoma tumours. In bladder cancer, these scans allow a better initial diagnosis for invasive cancer, while detecting occult metastases. • PET and its combined modality PET/CT have shown their potential in the diagnosis of urological malignancies. However, further studies are needed to establish the role of PET in the management of these diseases. Future applications of PET may involve fusion techniques such as magnetic resonance imaging with PET.

  19. High 18F-fluorodeoxyglucose (18F-FDG) uptake in microscopic peritoneal tumors requires physiological hypoxia

    PubMed Central

    Li, Xiao-Feng; Ma, Yuanyuan; Sun, Xiaorong; Humm, John L.; Ling, C. Clifton; O’Donoghue, Joseph A.

    2010-01-01

    The objective of this study was to examine 18F-fluorodeoxyglucose (18F-FDG) uptake in microscopic tumors grown intraperitoneally in nude mice and to relate this to physiological hypoxia and glucose transporter-1 (GLUT-1) expression. Methods Human colon cancer HT29 and HCT-8 cells were injected intraperitoneally into nude mice to generate disseminated tumors of varying sizes. Following overnight fasting, animals, either breathing air or carbogen (95% O2+ 5% CO2), were intravenously administered 18F-FDG together with the hypoxia marker pimonidazole (PIMO) and the cellular proliferation marker bromodeoxyuridine (BrdUrd) one hour before sacrifice. Hoechst 33342, a perfusion marker, was administered one minute before sacrifice. Following sacrifice, the intratumoral distribution of 18F-FDG was assessed by digital autoradiography of frozen tissue sections. This was compared with the distributions of PIMO, GLUT-1 expression, BrdUrd and Hoechst 33342 as visualized by immunofluorescent microscopy. Results Small tumors (< 1 mm diameter) had high 18F-FDG accumulation and were severely hypoxic with high GLUT-1 expression. Larger tumors (1–4 mm diameter) generally had low 18F-FDG accumulation and were not significantly hypoxic with low GLUT1 expression. Carbogen breathing significantly decreased 18F-FDG accumulation and tumor hypoxia in microscopic tumors but had little effect on GLUT1 expression. Conclusion There was high 18F-FDG uptake in microscopic tumors which was spatially associated with physiological hypoxia and high GLUT-1 expression. This enhanced uptake was abrogated by carbogen breathing, indicating that in the absence of physiological hypoxia, high GLUT1 expression, by itself, was insufficient to ensure high 18F-FDG uptake. PMID:20351353

  20. A rare cardiac haemangioma in the right ventricle diagnosed accurately using ¹⁸F-fluorodeoxyglucose-positron emission tomography.

    PubMed

    Matsuba, Tomoyuki; Hisashi, Yosuke; Yotsumoto, Goichi; Imoto, Yutaka

    2015-05-01

    A right ventricular cardiac tumour was incidentally detected in a 61-year-old man during a preoperative examination for coronary artery bypass grafting (CABG). Findings on computed tomography and magnetic resonance imaging suggested the differential diagnoses of myxoma, haemangioma and haemangiosarcoma, and it was difficult to identify whether the tumour was benign or malignant. (18)F-fluorodeoxyglucose-positron emission tomography strongly suggested a benign tumour. We enucleated the tumour, because an intraoperative frozen section also strongly suggested a benign origin. After resection, CABG under cardiopulmonary bypass was performed. Histopathological and immunohistochemical analysis indicated a cavernous haemangioma without evidence of malignant tissue. The patient has survived 20 months after surgery with no evidence of tumour recurrence.

  1. Suivi in situ de cultures tridimensionnelles en bioreacteur a perfusion grace a la tomographie d'emission par positrons

    NASA Astrophysics Data System (ADS)

    Chouinard, Julie

    The continuous assessment of developing tissue substitutes is crucial to understand their evolution over time. However, this represents quite a challenge when thick samples must be evaluated with standard microscopy techniques. Common characterization methods are time consuming and usually result in the destruction of the culture. Real-time, in situ, non-invasive and non-destructives methods are needed to monitor the growth of large non-transparent constructs in tissue engineering. Medical imaging modalities, which can provide information on the structure and function of internal organs and tissues in living organisms, have the potential of allowing repetitive monitoring of these 3D cultures in vitro. The working hypothesis of this thesis was to establish standard noninvasive and nondestructive real-time bioreactor imaging protocols for in situ monitoring of the viability and metabolism of endothelial cells when grown in perfused 3D fibrin gel scaffolds. To achieve this goal, a culture chamber with hollow fibers was designed and a pulsatile perfusion bioreactor system, able to promote cell survival and proliferation, was constructed and validated. Standard imaging protocols in Positron Emission Tomography (PET) are not adapted to image bioreactor systems. A suitable method had to be devised using the well-known radiotracer 18F-fluorodeoxyglucose ( 18FDG), a marker of glucose metabolism. Optimal uptake conditions were determined using cell monolayers and the best parameters were then applied on perfused 3D cultures to evaluate perfusion, cell viability and emerging cell structures. After only 12 hours of culture, the cell density could be estimated and cell structures were localized within the fibrin gels after 1-2 weeks of culture. PET is a promising tool for tissue engineering with many specific tracers available that might eventually be able to reveal new information on tissue development. Key words: Endothelial cells, Perfusion bioreactor, Positron Emission

  2. Increased uptake of 18F-fluorodeoxyglucose in postischemic myocardium of patients with exercise-induced angina

    SciTech Connect

    Camici, P.; Araujo, L.I.; Spinks, T.; Lammertsma, A.A.; Kaski, J.C.; Shea, M.J.; Selwyn, A.P.; Jones, T.; Maseri, A.

    1986-07-01

    Regional myocardial perfusion and exogenous glucose uptake were assessed with rubidium-82 (82Rb) and 18F-2-fluoro-2-deoxyglucose (FDG) in 10 normal volunteers and 12 patients with coronary artery disease and stable angina pectoris by means of positron emission tomography. In patients at rest, the myocardial uptake of /sup 82/Rb and FDG did not differ significantly from that measured in normal subjects. The exercise test performed within the positron camera in eight patients produced typical chest pain and ischemic electrocardiographic changes in all. In each of the eight patients a region of reduced cation uptake was demonstrated in the /sup 82/Rb scan recorded at peak exercise, after which uptake of /sup 82/Rb returned to the control value 5 to 14 min after the end of the exercise. In these patients, FDG was injected in the recovery phase when all the variables that were altered during exercise, including regional myocardial /sup 82/Rb uptake, had returned to control values. In all but one patient, FDG accumulation in the regions of reduced /sup 82/Rb uptake during exercise was significantly higher than that in the nonischemic regions, i.e., the ones with a normal increment of /sup 82/Rb uptake on exercise. In the nonischemic areas, FDG uptake was not significantly different from that found in normal subjects after exercise. In conclusion, myocardial glucose transport and phosphorylation seem to be enhanced in the postischemic myocardium of patients with exercise-induced ischemia.

  3. 18F-Fluorodeoxyglucose Uptake in Anti-N-Methyl-D-Aspartate-Receptor Encephalitis Associated With an Immature Teratoma.

    PubMed

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

    2017-02-01

    We report a case of anti-N-methyl-D-aspartate-receptor (anti-NMDAR) encephalitis associated with an immature teratoma developed in a 38-year-old woman. Positron emission tomography (PET) revealed focal intense uptake of F-fluorodeoxyglucose in an area of the brain corresponding to the right medial temporal lobe as well as an intrapelvic tumor. After the PET examination, the patient complained of disorientation and short-term memory loss. The ovarian tumor was resected and diagnosed as an immature teratoma. The cerebrospinal fluid analysis was positive for anti-NMDAR antibody. After surgery, the patient's neurologic symptoms improved. The PET finding of encephalitis associated with an immature teratoma was unexpected.

  4. Overview of positron emission tomography chemistry: clinical and technical considerations and combination with computed tomography.

    PubMed

    Koukourakis, G; Maravelis, G; Koukouraki, S; Padelakos, P; Kouloulias, V

    2009-01-01

    The concept of emission and transmission tomography was introduced by David Kuhl and Roy Edwards in the late 1950s. Their work later led to the design and construction of several tomographic instruments at the University of Pennsylvania. Tomographic imaging techniques were further developed by Michel Ter-Pogossian, Michael E. Phelps and others at the Washington University School of Medicine. Positron emission tomography (PET) is a nuclear medicine imaging technique which produces a 3-dimensional image or map of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule. Images of tracer concentration in 3-dimensional space within the body are then reconstructed by computer analysis. In modern scanners, this reconstruction is often accomplished with the aid of a CT X-ray scan performed on the patient during the same session, in the same machine. If the biologically active molecule chosen for PET is 18F-fluorodeoxyglucose (FDG), an analogue of glucose, the concentrations of tracer imaged give tissue metabolic activity in terms of regional glucose uptake. Although use of this tracer results in the most common type of PET scan, other tracer molecules are used in PET to image the tissue concentration of many other types of molecules of interest. The main role of this article was to analyse the available types of radiopharmaceuticals used in PET-CT along with the principles of its clinical and technical considerations.

  5. A Novel Method to Evaluate Local Control of Lung Cancer in Stereotactic Body Radiation Therapy (SBRT) Treatment Using 18F-FDG Positron Emission Tomography (PET)

    NASA Astrophysics Data System (ADS)

    Kathriarachchi, Vindu Wathsala

    An improved method is introduced for prediction of local tumor control following lung stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) patients using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET). A normalized background-corrected tumor maximum Standard Uptake Value (SUVcmax) is introduced using the mean uptake of adjacent aorta (SUVref), instead of the maximum uptake of lung tumor (SUVmax). This method minimizes the variations associated with SUVmax and objectively demonstrates a strong correlation between the low SUVcmax (< 2.5-3.0) and local control of post lung SBRT. The false positive rates of both SUVmax and SUVcmax increase with inclusion of early (<6 months) PET scans, therefore such inclusion is not recommended for assessing local tumor control of post lung SBRT.

  6. Evaluation of Simultaneous Dual-radioisotope SPECT Imaging Using 18F-fluorodeoxyglucose and 99mTc-tetrofosmin

    PubMed Central

    Takahashi, Yasuyuki; Mochiki, Mizuki; Koyama, Keiko; Ino, Toshihiko; Yamaji, Hiroyuki; Kawakami, Atsuko

    2016-01-01

    Objective(s): Use of a positron emission tomography (PET)/single-photon emission computed tomography (SPECT) system facilitates the simultaneous acquisition of images with fluorine-18 fluorodeoxyglucose (18F-FDG) and technetium (99mTc)-tetrofosmin. However, 18F has a short half-life, and 511 keV Compton-scattered photons are detected in the 99mTc energy window. Therefore, in this study, we aimed to investigate the consequences of these facts. Methods: The crosstalk correction for images in the 99mTc energy window involved the dual energy window (DEW) subtraction method. In phantom studies, changes in the count of uniform parts in a phantom (due to attenuation from decay), signal detectability in the hot-rod part of the phantom, and the defect contrast ratio in a cardiac phantom were examined. Results: For 18F-FDG in the step-and-shoot mode, nearly a 9% difference was observed in the count of projection data between the start and end positions of acquisition in the uniform part of the phantom. Based on the findings, the detectability of 12 mm hot rods was relatively poor. In the continuous acquisition mode, the count difference was corrected, and detectability of the hot rods was improved. The crosstalk from 18F to the 99mTc energy window was approximately 13%. In the cardiac phantom, the defect contrast in 99mTc images from simultaneous dual-radionuclide acquisition was improved by approximately 9% after DEW correction; the contrast after correction was similar to acquisition with 99mTc alone. Conclusion: Based on the findings, the continuous mode is useful for 18F-FDG acquisition, and DEW crosstalk correction is necessary for 99mTc-tetrofosmin imaging. PMID:27408894

  7. The metabolic landscape of cortico-basal ganglionic degeneration: regional asymmetries studied with positron emission tomography.

    PubMed Central

    Eidelberg, D; Dhawan, V; Moeller, J R; Sidtis, J J; Ginos, J Z; Strother, S C; Cederbaum, J; Greene, P; Fahn, S; Powers, J M

    1991-01-01

    Regional metabolic rate for glucose (rCMRGlc) was estimated using [18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) in five patients (four men, one woman; mean age 68; mean disease duration 2.4 years) with clinical findings consistent with the syndrome of cortico-basal ganglionic degeneration (CBGD). Left-right rCMRGlc asymmetry, (L-R)/(L + R) x 100, was calculated for 13 grey matter regions and compared with regional metabolic data from 18 normal volunteers and nine patients with asymmetrical Parkinson's disease (PD). In the CBGD group mean metabolic asymmetry values in the thalamus, inferior parietal lobule and hippocampus were greater than those measured in normal control subjects and patients with asymmetrical PD (p less than 0.02). Parietal lobe asymmetry of 5% or more was evident in all CBGD patients, whereas in PD patients and normal controls, all regional asymmetry measures were less than 5% in absolute value. Measures of frontal, parietal and hemispheric metabolic asymmetry were found to be positively correlated with asymmetries in thalamic rCMRGlc (p less than 0.05). The presence of cortico-thalamic metabolic asymmetry is consistent with the focal neuropathological changes reported in CBGD brains. Our findings suggest that metabolic asymmetries detected with FDG/PET may support a diagnosis of CBGD in life. Images PMID:1744638

  8. Regional Cerebral Glucose Metabolism in Novelty Seeking and Antisocial Personality: A Positron Emission Tomography Study

    PubMed Central

    Park, So Hyeon; Park, Hyun Soo

    2016-01-01

    Novelty seeking (NS) and antisocial personality (ASP) are commonly exhibited by those who suffer from addictions, such as substance abuse. NS has been suggested to be a fundamental aspect of ASP. To investigate the neurobiological substrate of NS and ASP, we tested the relationship between regional cerebral glucose metabolism and the level of NS, determining the differences between individuals with and without ASP. Seventy-two healthy adults (43 males, mean age±SD=38.8±16.6 years, range=20~70 years; 29 females, 44.2±20.1 years, range=19~72 years) underwent resting-state brain positron emission tomography (PET) 40 minutes after 18F-fluorodeoxyglucose (FDG) injection. Within 10 days of the FDG PET study, participants completed Cloninger's 240-item Temperament and Character Inventory (TCI) to determine NS scores. Participants with and without ASP were grouped according to their TCI profiles. Statistical parametric mapping analysis was performed using the FDG PET and TCI profile data. NS scores positively correlated with metabolism in the left anterior cingulate gyrus and the insula on both sides of the brain and negatively correlated with metabolism in the right pallidum and putamen. Participants with ASP showed differences in cerebral glucose metabolism across various cortical and subcortical regions, mainly in the frontal and prefrontal areas. These data demonstrate altered regional cerebral glucose metabolism in individuals with NS and ASP and inform our understanding of the neurobiological substrates of problematic behaviors and personality disorders. PMID:27574485

  9. Tumour response evaluation with fluorodeoxyglucose positron emission tomography: research technique or clinical tool?

    PubMed

    Anderson, H; Singh, N; Miles, K

    2010-10-04

    The evaluation of treatment response is an established role for imaging in oncologic research and clinical practice. In early phase trials, imaging response criteria are used to determine the presence and magnitude of the drug effect on tumour to aid decisions concerning progress to late phase trials, and to inform dose selection and scheduling. In late phase trials and clinical practice, the imaging response is used as a surrogate for clinical outcome. Due to the limitations of current anatomic response criteria, there is growing interest in the use of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) to assess treatment response. The technique is beginning to be adopted within mainstream approaches for evaluation of response in solid tumours and lymphoma. Difficulties with standardisation across PET centres and tumour types combined with uncertainty concerning the timing of assessment relative to treatment, have limited the use of quantitative measurements of FDG uptake to research applications. However, with a growing body of evidence that qualitative criteria such as the development of new PET lesions or complete metabolic response following treatment can provide surrogates marker for clinical outcome, [(18)F]FDG-PET is becoming established as a clinical technique for assessing tumour response, especially for FDG-avid lymphoma subtypes. Multimodality imaging using perfusion computed tomography/PET is an exciting novel technique with the potential to define treatment response in a new way.

  10. Positron emission tomography in aging and dementia: effect of cerebral atrophy

    SciTech Connect

    Chawluk, J.B.; Alavi, A.; Dann, R.; Hurtig, H.I.; Bais, S.; Kushner, M.J.; Zimmerman, R.A.; Reivich, M.

    1987-04-01

    The spatial resolution of current positron emission tomography (PET) scanners does not allow a distinction between cerebrospinal fluid (CSF) containing spaces and contiguous brain tissue. Data analysis strategies which therefore purport to quantify cerebral metabolism per unit mass brain tissue are in fact measuring a value which may be artifactually reduced due to contamination by CSF. We studied cerebral glucose metabolism (CMRglc) in 17 healthy elderly individuals and 24 patients with Alzheimer's dementia using (/sup 18/F)fluorodeoxyglucose and PET. All subjects underwent x-ray computed tomography (XCT) scanning at the time of their PET study. The XCT scans were analyzed volumetrically, in order to determine relative areas for ventricles, sulci, and brain tissue. Global CMRglc was calculated before and after correction for contamination by CSF (cerebral atrophy). A greater increase in global CMRglc after atrophy correction was seen in demented individuals compared with elderly controls (16.9% versus 9.0%, p less than 0.0005). Additional preliminary data suggest that volumetric analysis of proton-NMR images may prove superior to analysis of XCT data in quantifying the degree of atrophy. Appropriate corrections for atrophy should be employed if current PET scanners are to accurately measure actual brain tissue metabolism in various pathologic states.

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

    SciTech Connect

    Gordin, Arie . E-mail: ariegor@hotmail.com; Golz, Avishay; Daitzchman, Marcello; Keidar, Zohar; Bar-Shalom, Rachel; Kuten, Abraham; Israel, Ora

    2007-06-01

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

  12. Positron Emission Tomography (PET)

    DOE R&D Accomplishments Database

    Welch, M. J.

    1990-01-01

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

  13. Positron Emission Tomography (PET)

    SciTech Connect

    Welch, M.J.

    1990-01-01

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

  14. [18F]-FDG positron emission tomography--an established clinical tool opening a new window into exercise physiology.

    PubMed

    Rudroff, Thorsten; Kindred, John H; Kalliokoski, Kari K

    2015-05-15

    Positron emission tomography (PET) with [(18)F]-fluorodeoxyglucose (FDG) is an established clinical tool primarily used to diagnose and evaluate disease status in patients with cancer. PET imaging using FDG can be a highly valuable tool to investigate normal human physiology by providing a noninvasive, quantitative measure of glucose uptake into various cell types. Over the past years it has also been increasingly used in exercise physiology studies to identify changes in glucose uptake, metabolism, and muscle activity during different exercise modalities. Metabolically active cells transport FDG, an (18)fluorine-labeled glucose analog tracer, from the blood into the cells where it is then phosphorylated but not further metabolized. This metabolic trapping process forms the basis of this method's use during exercise. The tracer is given to a participant during an exercise task, and the actual PET imaging is performed immediately after the exercise. Provided the uptake period is of sufficient duration, and the imaging is performed shortly after the exercise; the captured image strongly reflects the metabolic activity of the cells used during the task. When combined with repeated blood sampling to determine tracer blood concentration over time, also known as the input function, glucose uptake rate of the tissues can be quantitatively calculated. This synthesis provides an accounting of studies using FDG-PET to measure acute exercise-induced skeletal muscle activity, describes the advantages and limitations of this imaging technique, and discusses its applications to the field of exercise physiology.

  15. Effect of real-time weighted integration system for rapid calculation of functional images in clinical positron emission tomography

    SciTech Connect

    Iida, Hidehiro; Bloomfield, P.M.; Miura, Shuichi

    1995-03-01

    A system has been developed to rapidly calculate images of parametric rate constants, without acquiring dynamic frame data for clinical positron emission tomography (PET). This method is based on the weighted-integration algorithms for the two- and three-compartment models, and hardware developments (real-time operation and a large cache memory system) in a PET scanner, Headtome-IV, which enables the acquisition of multiple sinograms with independent weight integration functions. Following the administration of the radio-tracer, the scan is initiated to collect multiple time-weighted, integrated sinograms with three different weight functions. These sinograms are reconstructed and the images, with the arterial blood data, are inserted into the operational equations to provide parametric rate constant images. The implementation of this method has been checked in H{sub 2} {sup 15}O and {sup 18}F-fluorophenylalanine ({sup 18}FPhe) studies based on a two-compartment model, and in a {sup 18}F-fluorodeoxyglucose ({sup 18}FDG) study based on the three-compartment model. A volunteer study, completed for each compound, yielded results consistent with those produced by existing nonlinear fitting methods. Thus, this system has been developed capable of generating rapidly quantitative, physiological images, without dynamic data acquisition, which will be of great advantage to PET in the clinical environment. This system would also be of great advantage in the new generation high-resolution PET tomography, which acquire data in a 3-D, septaless mode.

  16. A Novel Positron Emission Tomography (PET) Approach to Monitor Cardiac Metabolic Pathway Remodeling in Response to Sunitinib Malate

    PubMed Central

    Silvola, Johanna M. U.; Miller, Ian S.; Conroy, Emer; Hector, Suzanne; Cary, Maurice; Murray, David W.; Jarzabek, Monika A.; Maratha, Ashwini; Alamanou, Marina; Udupi, Girish Mallya; Shiels, Liam; Pallaud, Celine; Saraste, Antti; Liljenbäck, Heidi; Jauhiainen, Matti; Oikonen, Vesa; Ducret, Axel; Cutler, Paul; McAuliffe, Fionnuala M.; Rousseau, Jacques A.; Lecomte, Roger; Gascon, Suzanne; Arany, Zoltan; Ky, Bonnie; Force, Thomas; Knuuti, Juhani; Gallagher, William M.; Roivainen, Anne; Byrne, Annette T.

    2017-01-01

    Sunitinib is a tyrosine kinase inhibitor approved for the treatment of multiple solid tumors. However, cardiotoxicity is of increasing concern, with a need to develop rational mechanism driven approaches for the early detection of cardiac dysfunction. We sought to interrogate changes in cardiac energy substrate usage during sunitinib treatment, hypothesising that these changes could represent a strategy for the early detection of cardiotoxicity. Balb/CJ mice or Sprague-Dawley rats were treated orally for 4 weeks with 40 or 20 mg/kg/day sunitinib. Cardiac positron emission tomography (PET) was implemented to investigate alterations in myocardial glucose and oxidative metabolism. Following treatment, blood pressure increased, and left ventricular ejection fraction decreased. Cardiac [18F]-fluorodeoxyglucose (FDG)-PET revealed increased glucose uptake after 48 hours. [11C]Acetate-PET showed decreased myocardial perfusion following treatment. Electron microscopy revealed significant lipid accumulation in the myocardium. Proteomic analyses indicated that oxidative metabolism, fatty acid β-oxidation and mitochondrial dysfunction were among the top myocardial signalling pathways perturbed. Sunitinib treatment results in an increased reliance on glycolysis, increased myocardial lipid deposition and perturbed mitochondrial function, indicative of a fundamental energy crisis resulting in compromised myocardial energy metabolism and function. Our findings suggest that a cardiac PET strategy may represent a rational approach to non-invasively monitor metabolic pathway remodeling following sunitinib treatment. PMID:28129334

  17. Interrogating Tumor Metabolism and Tumor Microenvironments Using Molecular Positron Emission Tomography Imaging. Theranostic Approaches to Improve Therapeutics

    PubMed Central

    Jacobson, Orit

    2013-01-01

    Positron emission tomography (PET) is a noninvasive molecular imaging technology that is becoming increasingly important for the measurement of physiologic, biochemical, and pharmacological functions at cellular and molecular levels in patients with cancer. Formation, development, and aggressiveness of tumor involve a number of molecular pathways, including intrinsic tumor cell mutations and extrinsic interaction between tumor cells and the microenvironment. Currently, evaluation of these processes is mainly through biopsy, which is invasive and limited to the site of biopsy. Ongoing research on specific target molecules of the tumor and its microenvironment for PET imaging is showing great potential. To date, the use of PET for diagnosing local recurrence and metastatic sites of various cancers and evaluation of treatment response is mainly based on [18F]fluorodeoxyglucose ([18F]FDG), which measures glucose metabolism. However, [18F]FDG is not a target-specific PET tracer and does not give enough insight into tumor biology and/or its vulnerability to potential treatments. Hence, there is an increasing need for the development of selective biologic radiotracers that will yield specific biochemical information and allow for noninvasive molecular imaging. The possibility of cancer-associated targets for imaging will provide the opportunity to use PET for diagnosis and therapy response monitoring (theranostics) and thus personalized medicine. This article will focus on the review of non-[18F]FDG PET tracers for specific tumor biology processes and their preclinical and clinical applications. PMID:24064460

  18. Positron emission tomography with (18F)methylspiperone demonstrates D2 dopamine receptor binding differences of clozapine and haloperidol.

    PubMed

    Karbe, H; Wienhard, K; Hamacher, K; Huber, M; Herholz, K; Coenen, H H; Stöcklin, G; Lövenich, A; Heiss, W D

    1991-01-01

    Four schizophrenic patients were investigated with dynamic positron emission tomography (PET) using (18F)fluorodeoxyglucose (FDG) and (18F)methylspiperone (MSP) as tracers. Two schizophrenics were on haloperidol therapy at the time of MSP PET. The other two schizophrenics were treated with clozapine, in one of them MSP PET was carried out twice with different daily doses (100 mg and 450 mg respectively). Neuroleptic serum levels were measured in all patients. Results were compared with MSP PET of two drug-free male control subjects and with a previous fluoroethylspiperone (FESP) study of normals. Three hours after tracer injection specific binding of MSP was observed in the striatum in all cases. The striatum to cerebellum ratio was used to estimate the degree of neuroleptic-caused striatal D2 dopamine receptor occupancy. In the haloperidol treated patients MSP binding was significantly decreased, whereas in the clozapine treated patients striatum to cerebellum ratio was normal. Even the increase of clozapine dose in the same patient had no influence on this ratio. Despite the smaller number of patients the study shows for the first time in humans that striatal MSP binding reflects the different D2 dopamine receptor affinities of clozapine and haloperidol.

  19. Positron emission mammography imaging

    SciTech Connect

    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. In vitro positron emission tomography (PET): use of positron emission tracers in functional imaging in living brain slices.

    PubMed

    Matsumura, K; Bergström, M; Onoe, H; Takechi, H; Westerberg, G; Antoni, G; Bjurling, P; Jacobson, G B; Långström, B; Watanabe, Y

    1995-05-01

    Positron-emitting radionuclides have short half-lives and high radiation energies compared with radioisotopes generally used in biomedical research. We examined the possibility of applying positron emitter-labeled compounds to functional imaging in brain slices kept viable in an oxygenated buffer solution. Brain slices (300 microns thick) containing the striatum were incubated with positron emitter-labeled tracers for 30-45 min. The slices were then rinsed and placed on the bottom of a Plexiglas chamber filled with oxygenated Krebs-Ringer solution. The bottom of the chamber consisted of a thin polypropylene film to allow good penetration of beta+ particles from the brain slices. The chamber was placed on a storage phosphor screen, which has a higher sensitivity and a wider dynamic range than X-ray films. After an exposure period of 15-60 min, the screen was scanned by the analyzer and radioactivity images of brain slices were obtained within 20 min. We succeeded in obtaining quantitative images of (1) [18F]fluorodeoxyglucose uptake, (2) dopamine D2 receptor binding, (3) dopa-decarboxylase activity, and (4) release of [11C]dopamine preloaded as L-[11C]DOPA in the brain slice preparation. These results demonstrate that positron emitter-labeled tracers in combination with storage phosphor screens are useful for functional imaging of living brain slices as a novel neuroscience technique.

  1. Influence of the partial volume correction method on 18F-fluorodeoxyglucose brain kinetic modelling from dynamic PET images reconstructed with resolution model based OSEM

    NASA Astrophysics Data System (ADS)

    Bowen, Spencer L.; Byars, Larry G.; Michel, Christian J.; Chonde, Daniel B.; Catana, Ciprian

    2013-10-01

    Kinetic parameters estimated from dynamic 18F-fluorodeoxyglucose (18F-FDG) PET acquisitions have been used frequently to assess brain function in humans. Neglecting partial volume correction (PVC) for a dynamic series has been shown to produce significant bias in model estimates. Accurate PVC requires a space-variant model describing the reconstructed image spatial point spread function (PSF) that accounts for resolution limitations, including non-uniformities across the field of view due to the parallax effect. For ordered subsets expectation maximization (OSEM), image resolution convergence is local and influenced significantly by the number of iterations, the count density, and background-to-target ratio. As both count density and background-to-target values for a brain structure can change during a dynamic scan, the local image resolution may also concurrently vary. When PVC is applied post-reconstruction the kinetic parameter estimates may be biased when neglecting the frame-dependent resolution. We explored the influence of the PVC method and implementation on kinetic parameters estimated by fitting 18F-FDG dynamic data acquired on a dedicated brain PET scanner and reconstructed with and without PSF modelling in the OSEM algorithm. The performance of several PVC algorithms was quantified with a phantom experiment, an anthropomorphic Monte Carlo simulation, and a patient scan. Using the last frame reconstructed image only for regional spread function (RSF) generation, as opposed to computing RSFs for each frame independently, and applying perturbation geometric transfer matrix PVC with PSF based OSEM produced the lowest magnitude bias kinetic parameter estimates in most instances, although at the cost of increased noise compared to the PVC methods utilizing conventional OSEM. Use of the last frame RSFs for PVC with no PSF modelling in the OSEM algorithm produced the lowest bias in cerebral metabolic rate of glucose estimates, although by less than 5% in most

  2. The Usefulness of Positron-Emission Tomography Findings in the Management of Anterior Mediastinal Tumors

    PubMed Central

    Sano, Fumitoshi; Ohashi, Shinichi; Suzuki, Kosuke; Uematsu, Shugo; Suzuki, Takashi; Kadokura, Mitsutaka

    2017-01-01

    Purpose: We performed a retrospective analysis to evaluate the usefulness of positron-emission tomography/computed tomography (PET/CT) findings in the classification and management of anterior mediastinal tumors. Methods: Between 2006 and 2015, 105 patients with anterior mediastinal tumor received PET/CT. 18F-fluorodeoxyglucose (18F-FDG)-PET images were obtained 60 minutes after the injection of 18F-FDG. Results: The histological classifications were as follows: thymoma (n = 49), thymic carcinoma (TC) (n = 19), malignant lymphoma (ML) (n = 8), teratoma (n = 7), thymic cyst (n = 14), and others (n = 8). Upon visual inspection (SUV max: >2.0), all of the malignant tumors showed 18F-FDG accumulation (with the exception of one type A thymoma). Two of the 14 thymic cysts and three of the seven teratomas showed slight 18F-FDG accumulation. The SUV max values of the low-grade thymomas, high-grade thymomas, TCs and MLs were 3.14 ± 0.73, 4.34 ± 1.49, 8.59 ± 3.05, and 10.08 ± 2.53, respectively, with significant differences between the low- and high-grade thymomas, and between TCs and MLs. The sensitivity, specificity and accuracy of 18F-FDG in the detection of low-grade thymomas and thymomas with a maximum diameter of ≤50 mm and an SUV max of ≤3.4 were 85%, 48%, and 60%, respectively. Conclusion: FDG-PET/CT is an objective and useful modality in the differential diagnosis and management of anterior mediastinal tumors. PMID:28123154

  3. Four-Dimensional Positron Emission Tomography: Implications for Dose Painting of High-Uptake Regions

    SciTech Connect

    Aristophanous, Michalis; Killoran, Joseph H.; Chen, Aileen B.; Berbeco, Ross I.

    2011-07-01

    Purpose: To investigate the behavior of tumor subvolumes of high [18F]-fluorodeoxyglucose (FDG) uptake as seen on clinical four-dimensional (4D) FDG-positron emission tomography (PET) scans. Methods and Materials: Four-dimensional FDG-PET/computed tomography scans from 13 patients taken before radiotherapy were available. The analysis was focused on regions of high uptake that are potential dose-painting targets. A total of 17 lesions (primary tumors and lymph nodes) were analyzed. On each one of the five phases of the 4D scan a classification algorithm was applied to obtain the region of highest uptake and segment the tumor volume. We looked at the behavior of both the high-uptake subvolume, called 'Boost,' and the segmented tumor volume, called 'Target.' We measured several quantities that characterize the Target and Boost volumes and quantified correlations between them. Results: The behavior of the Target could not always predict the behavior of the Boost. The shape deformation of the Boost regions was on average 133% higher than that of the Target. The gross to internal target volume expansion was on average 27.4% for the Target and 64% for the Boost, a statistically significant difference (p < 0.05). Finally, the inhale-to-exhale phase (20%) had the highest shape deformation for the Boost regions. Conclusions: A complex relationship between the measured quantities for the Boost and Target volumes is revealed. The results suggest that in cases in which advanced therapy techniques such as dose painting are being used, a close examination of the 4D PET scan should be performed.

  4. Detection of occult disease in breast cancer using fluorodeoxyglucose camera-based positron emission tomography.

    PubMed

    Pecking, A P; Mechelany-Corone, C; Bertrand-Kermorgant, F; Alberini, J L; Floiras, J L; Goupil, A; Pichon, M F

    2001-10-01

    An isolated increase of blood tumor marker CA 15.3 in breast cancer is considered a sensitive indicator for occult metastatic disease but by itself is not sufficient for initiating therapeutic intervention. We investigated the potential of camera-based positron emission tomography (PET) imaging using [18F]-fluorodeoxyglucose (FDG) to detect clinically occult recurrences in 132 female patients (age, 35-69 years) treated for breast cancer, all presenting with an isolated increase in blood tumor marker CA 15.3 without any other evidence of metastatic disease. FDG results were correlated to pathology results or to a sequentially guided conventional imaging method. One hundred nineteen patients were eligible for correlations. Positive FDG scans were obtained for 106 patients, including 89 with a single lesion and 17 with 2 or more lesion. There were 92 true-positive and 14 false-positive cases, 10 of which became true positive within 1 year. Among the 13 negative cases, 7 were false negative and 6 were true negative. Camera-based PET using FDG has successfully identified clinically occult disease with an overall sensitivity of 93.6% and a positive predictive value of 96.2%. The smallest detected size was 6 mm for a lymph node metastasis (tumor to nontumor ratio, 4:2). FDG camera-based PET localized tumors in 85.7% of cases suspected for clinically occult metastatic disease on the basis of a significant increase in blood tumor marker. A positive FDG scan associated with an elevated CA 15.3 level is most consistent with metastatic relapse of breast cancer.

  5. Imaging Enterobacteriaceae infection in vivo with 18F-fluorodeoxysorbitol positron emission tomography

    PubMed Central

    Weinstein, Edward A.; Ordonez, Alvaro A.; DeMarco, Vincent P.; Murawski, Allison M.; Pokkali, Supriya; MacDonald, Elizabeth M.; Klunk, Mariah; Mease, Ronnie C.; Pomper, Martin G.; Jain, Sanjay K.

    2015-01-01

    The Enterobacteriaceae are a family of rod-shaped Gram-negative bacteria that normally inhabit the gastrointestinal tract and are the most common cause of Gram-negative bacterial infections in humans. In addition to causing serious multidrug-resistant, hospital-acquired infections, a number of Enterobacteriaceae species are also recognized as biothreat pathogens. As a consequence, new tools are urgently needed to specifically identify and localize infections due to Enterobacteriaceae and to monitor antimicrobial efficacy. In this report, we used commercially available 2-[18F]-fluorodeoxyglucose (18F-FDG) to produce 2-[18F]-fluorodeoxysorbitol (18F-FDS), a radioactive probe for Enterobacteriaceae, in 30 min. 18F-FDS selectively accumulated in Enterobacteriaceae, but not in Gram-positive bacteria or healthy mammalian or cancer cells in vitro. In a murine myositis model, 18F-FDS positron emission tomography (PET) rapidly differentiated true infection from sterile inflammation with a limit of detection of 6.2 ± 0.2 log10 colony-forming units (CFU) for Escherichia coli. Our findings were extended to models of mixed Gram-positive and Gram-negative thigh co-infections, brain infection, Klebsiella pneumonia, and mice undergoing immunosuppressive chemotherapy. This technique rapidly and specifically localized infections due to Enterobacteriaceae, providing a three-dimensional holistic view within the animal. Last, 18F-FDS PET monitored the efficacy of antimicrobial treatment, demonstrating a PET signal proportionate to the bacterial burden. Therapeutic failures associated with multidrug-resistant, extended-spectrum β-lactamase (ESBL)–producing E. coli infections were detected in real time. Together, these data show that 18F-FDS is a candidate imaging probe for translation to human clinical cases of known or suspected infections owing to Enterobacteriaceae. PMID:25338757

  6. [Accidental discovery of 18F-fluorodeoxyglucose PET/CT-positive papilloma in sinus sphenoidalis in a patient with recurrence of breast cancer].

    PubMed

    Hansen, Lasse Berg

    2015-02-02

    A patient suspected for metastatic breast cancer went through an 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT). Along with metastatic lymph nodes in the neck it showed high 18F-FDG uptake in a polypoidal structure in the sinus sphenoidalis. When asked she had no related symptoms due to the sphenoid polyp and the CT-scan showed no bone destruction. To rule out malignancy a biopsy was made showing benign sinonasal papilloma of oncocytic origin. High 18F-FDG PET uptake can be seen in benign structures and should therefore not be the only predictor for malignancy.

  7. Cerebral glucose utilization during sleep-wake cycle in man determined by positron emission tomography and [18F]2-fluoro-2-deoxy-D-glucose method.

    PubMed

    Maquet, P; Dive, D; Salmon, E; Sadzot, B; Franco, G; Poirrier, R; von Frenckell, R; Franck, G

    1990-04-09

    Using the [18F]fluorodeoxyglucose method and positron emission tomography, we studied cerebral glucose utilization during sleep and wakefulness in 11 young normal subjects. Each of them was studied at least thrice: during wakefulness, slow wave sleep (SWS) and rapid eye movement sleep (REMS), at 1 week intervals. Four stage 3-4 SWS and 4 REMS fulfilled the steady state conditions of the model. The control population consisted of 9 normal age-matched subjects studied twice during wakefulness at, at least, 1 week intervals. Under these conditions, the average difference between the first and the second cerebral glucose metabolic rates (CMRGlu was: -7.91 +/- 15.46%, which does not differ significantly from zero (P = 0.13). During SWS, a significant decrease in CMRGlu was observed as compared to wakefulness (mean difference: -43.80 +/- 14.10%, P less than 0.01). All brain regions were equally affected but thalamic nuclei had significantly lower glucose utilization than the average cortex. During REMS, the CMRGlu were as high as during wakefulness (mean difference: 4.30 +/- 7.40%, P = 0.35). The metabolic pattern during REMS appeared more heterogeneous than at wake. An activation of left temporal and occipital areas is suggested. It is hypothetized that energy requirements for maintaining membrane polarity are reduced during SWS because of a decreased rate of synaptic events. During REMS, cerebral glucose utilization is similar to that of wakefulness, presumably because of reactivated neurotransmission and increased need for ion gradients maintenance.

  8. Comparison of Positron Emission Tomography Scanning and Sentinel Node Biopsy in the Detection of Inguinal Node Metastases in Patients With Anal Cancer

    SciTech Connect

    Mistrangelo, Massimiliano; Pelosi, Ettore; Bello, Marilena; Castellano, Isabella; Cassoni, Paola; Ricardi, Umberto; Munoz, Fernando; Racca, Patrizia; Contu, Viviana; Beltramo, Giancarlo; Morino, Mario; Mussa, Antonio

    2010-05-01

    Background: Inguinal lymph node metastases in patients with anal cancer are an independent prognostic factor for local failure and overall mortality. Inguinal lymph node status can be adequately assessed with sentinel node biopsy, and the radiotherapy strategy can subsequently be changed. We compared this technique vs. dedicated 18F-fluorodeoxyglucose positron emission tomography (PET) to determine which was the better tool for staging inguinal lymph nodes. Methods and Materials: In our department, 27 patients (9 men and 18 women) underwent both inguinal sentinel node biopsy and PET-CT. PET-CT was performed before treatment and then at 1 and 3 months after treatment. Results: PET-CT scans detected no inguinal metastases in 20 of 27 patients and metastases in the remaining 7. Histologic analysis of the sentinel lymph node detected metastases in only three patients (four PET-CT false positives). HIV status was not found to influence the results. None of the patients negative at sentinel node biopsy developed metastases during the follow-up period. PET-CT had a sensitivity of 100%, with a negative predictive value of 100%. Owing to the high number of false positives, PET-CT specificity was 83%, and positive predictive value was 43%. Conclusions: In this series of patients with anal cancer, inguinal sentinel node biopsy was superior to PET-CT for staging inguinal lymph nodes.

  9. The Synthesis and Evaluations of the 68Ga-Lissamine Rhodamine B (LRB) as a New Radiotracer for Imaging Tumors by Positron Emission Tomography

    PubMed Central

    Li, Xuena; Yin, Yafu; Du, Bulin; Li, Na; Li, Yaming

    2016-01-01

    Purpose. The aim of this study is to synthesize and evaluate 68Ga-labeled Lissamine Rhodamine B (LRB) as a new radiotracer for imaging MDA-MB-231 and MCF-7 cells induced tumor mice by positron emission tomography (PET). Methods. Firstly, we performed the radio synthesis and microPET imaging of 68Ga(DOTA-LRB) in athymic nude mice bearing MDA-MB-231 and MCF-7 human breast cancer xenografts. Additionally, the evaluations of 18F-fluorodeoxyglucose (FDG), as a glucose metabolism radiotracer for imaging tumors in the same xenografts, have been conducted as a comparison. Results. The radiochemical purity of 68Ga(DOTA-LRB) was >95%. MicroPET dynamic imaging revealed that the uptake of 68Ga(DOTA-LRB) was mainly in normal organs, such as kidney, heart, liver, and brain and mainly excreted from kidney. The MDA-MB-231 and MCF-7 tumors were not clearly visible in PET images at 5, 15, 30, 40, 50, and 60 min after injection of 68Ga(DOTA-LRB). The tumor uptake values of 18F-FDG were 3.79 ± 0.57 and 1.93 ± 0.48%ID/g in MDA-MB-231 and MCF-7 tumor xenografts, respectively. Conclusions. 68Ga(DOTA-LRB) can be easily synthesized with high radiochemical purity and stability; however, it may be not an ideal PET radiotracer for imaging of MDR-positive tumors. PMID:26949707

  10. Characterization of pulmonary lesions in patients with suspected lung cancer: computed tomography versus [¹⁸F] fluorodeoxyglucose-positron emission tomography/computed tomography.

    PubMed

    Harders, Stefan Walbom; Madsen, Hans Henrik; Hjorthaug, Karin; Arveschoug, Anne Kirstine; Rasmussen, Torben Riis; Meldgaard, Peter; Andersen, Johanne Bach; Pilegaard, Hans Kristian; Hager, Henrik; Rehling, Michael; Rasmussen, Finn

    2012-10-16

    Pulmonary nodules are of high clinical importance, given they may prove to be an early manifestation of lung cancer. Pulmonary nodules are small, focal, radiographic opacities that may be solitary or multiple. A solitary pulmonary nodule is a single, small (<-30 mm in diameter) opacity. Larger opacities are called masses and are often malignant. As imaging techniques improve and more nodules are detected, the optimal management of pulmonary nodules remains unclear. However, the question of malignancy of any given nodule remains the same. A standard contrast-enhanced computed tomography (CT) scan is often the first examination, followed by a number of other examinations. The purpose of this study was to examine the clinical feasibility of CT versus integrated [18F]fluorodeoxyglucose-positron emission tomography (PET)/low-dose CT scan in patients with suspected lung cancer and pulmonary lesions on CT. All results were controlled for reproducibility. We found that when used early in the work-up of the lesions, CT raised the prevalence of lung cancer in the population to the point where further diagnostic imaging examination could be considered futile. We also found that the overall diagnostic accuracy, as well as the classification probabilities and predictive values of the two modalities were not significantly different; the reproducibility of these results was substantial.

  11. NOTE: The use of molecular sieves to simulate hot lesions in 18F-fluorodeoxyglucose—positron emission tomography imaging

    NASA Astrophysics Data System (ADS)

    Matheoud, R.; Secco, C.; Ridone, S.; Inglese, E.; Brambilla, M.

    2008-04-01

    We investigated the use of a kind of zeolite, the Bowie chabazite, to produce radioactive sources of different shapes, dimensions and activity concentrations that can be used for lesion simulation in positron emission tomography (PET) imaging. The 18F-fluorodeoxyglucose (18F-FDG) uptake of a group of 12 zeolites was studied as a function of their weight (120-1520 mg) and of the activity concentration of the 18F-FDG solution (1-37 MBq ml-1), using a multiple linear regression model. The reproducibility, homogeneity and stability over time of the 18F-FDG uptake were assessed. The fit of the regression model is good (r2 = 0.83). This relation allows the production of zeolites of a desired 18F-FDG activity using knowledge of the concentration of the soaking solution and the weight of the zeolite. The reproducibility of the 18F-FDG uptake after heating the zeolites is elevated (CV% = 3.68). The almost complete regeneration of the zeolites allows us to reuse them in successive experiments. The stability of the 18F-FDG uptake on zeolites is far from ideal. When placed in a saline solution the 'activated' zeolites release the 18F-FDG with an effective half-time of 53 min. The sealing of the zeolites in plastic film bags has been demonstrated to be effective in preventing any release of 18F-FDG. These features, together with their variable dimensions and shapes, make them ideal 18F-FDG sources with a fixed target-to-background ratio that can be placed anywhere in a phantom to study lesion detectability in PET imaging.

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

    PubMed Central

    2016-01-01

    The purpose of this study was to estimate average radiation exposure from 18F-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 < 0.001). Advanced PET technologies such as time-of-flight acquisition and point-spread function recovery were also 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

  13. (18)F-labeled positron emission tomographic radiopharmaceuticals in oncology: an overview of radiochemistry and mechanisms of tumor localization.

    PubMed

    Vallabhajosula, Shankar

    2007-11-01

    Molecular imaging is the visualization, characterization, and measurement of biological processes at the molecular and cellular levels in a living system. At present, positron emission tomography/computed tomography (PET/CT) is one 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" and "tumor cell signal-specific" PET radiopharmaceuticals are essential to meet the growing demand of radioisotope-based molecular imaging technology. In the last 15 years, many alternative PET tracers have been proposed and evaluated in preclinical and clinical studies to characterize the tumor biology more appropriately. The potential clinical utility of several (18)F-labeled radiotracers (eg, fluoride, FDOPA, FLT, FMISO, FES, and FCH) is being reviewed by several investigators in this issue. An overview of design and development of (18)F-labeled PET radiopharmaceuticals, radiochemistry, and mechanism(s) of tumor cell uptake and localization of radiotracers are presented here. The approval of clinical indications for FDG-PET in the year 2000 by the Food and Drug Administration, based on a review of literature, was a major breakthrough to the rapid incorporation of PET into nuclear medicine practice, particularly in oncology. Approval of a radiopharmaceutical typically involves submission of a "New Drug Application" by a manufacturer or a company clearly documenting 2 major aspects of the drug: (1) manufacturing of PET drug using current good manufacturing practices and (2) the safety and effectiveness of a drug with specific indications. The potential routine clinical utility of (18)F-labeled PET radiopharmaceuticals depends also on

  14. A Gaussian mixture model for definition of lung tumor volumes in positron emission tomography.

    PubMed

    Aristophanous, Michalis; Penney, Bill C; Martel, Mary K; Pelizzari, Charles A

    2007-11-01

    The increased interest in 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in radiation treatment planning in the past five years necessitated the independent and accurate segmentation of gross tumor volume (GTV) from FDG-PET scans. In some studies the radiation oncologist contours the GTV based on a computed tomography scan, while incorporating pertinent data from the PET images. Alternatively, a simple threshold, typically 40% of the maximum intensity, has been employed to differentiate tumor from normal tissue, while other researchers have developed algorithms to aid the PET based GTV definition. None of these methods, however, results in reliable PET tumor segmentation that can be used for more sophisticated treatment plans. For this reason, we developed a Gaussian mixture model (GMM) based segmentation technique on selected PET tumor regions from non-small cell lung cancer patients. The purpose of this study was to investigate the feasibility of using a GMM-based tumor volume definition in a robust, reliable and reproducible way. A GMM relies on the idea that any distribution, in our case a distribution of image intensities, can be expressed as a mixture of Gaussian densities representing different classes. According to our implementation, each class belongs to one of three regions in the image; the background (B), the uncertain (U) and the target (T), and from these regions we can obtain the tumor volume. User interaction in the implementation is required, but is limited to the initialization of the model parameters and the selection of an "analysis region" to which the modeling is restricted. The segmentation was developed on three and tested on another four clinical cases to ensure robustness against differences observed in the clinic. It also compared favorably with thresholding at 40% of the maximum intensity and a threshold determination function based on tumor to background image intensities proposed in a recent paper. The parts of the

  15. A Gaussian mixture model for definition of lung tumor volumes in positron emission tomography

    SciTech Connect

    Aristophanous, Michalis; Penney, Bill C.; Martel, Mary K.; Pelizzari, Charles A.

    2007-11-15

    The increased interest in {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in radiation treatment planning in the past five years necessitated the independent and accurate segmentation of gross tumor volume (GTV) from FDG-PET scans. In some studies the radiation oncologist contours the GTV based on a computed tomography scan, while incorporating pertinent data from the PET images. Alternatively, a simple threshold, typically 40% of the maximum intensity, has been employed to differentiate tumor from normal tissue, while other researchers have developed algorithms to aid the PET based GTV definition. None of these methods, however, results in reliable PET tumor segmentation that can be used for more sophisticated treatment plans. For this reason, we developed a Gaussian mixture model (GMM) based segmentation technique on selected PET tumor regions from non-small cell lung cancer patients. The purpose of this study was to investigate the feasibility of using a GMM-based tumor volume definition in a robust, reliable and reproducible way. A GMM relies on the idea that any distribution, in our case a distribution of image intensities, can be expressed as a mixture of Gaussian densities representing different classes. According to our implementation, each class belongs to one of three regions in the image; the background (B), the uncertain (U) and the target (T), and from these regions we can obtain the tumor volume. User interaction in the implementation is required, but is limited to the initialization of the model parameters and the selection of an 'analysis region' to which the modeling is restricted. The segmentation was developed on three and tested on another four clinical cases to ensure robustness against differences observed in the clinic. It also compared favorably with thresholding at 40% of the maximum intensity and a threshold determination function based on tumor to background image intensities proposed in a recent paper. The parts of

  16. Positron emission tomography has a high negative predictive value for progression or early relapse for patients with residual disease after first-line chemotherapy in advanced-stage Hodgkin lymphoma

    PubMed Central

    Kobe, Carsten; Dietlein, Markus; Franklin, Jeremy; Markova, Jana; Lohri, Andreas; Amthauer, Holger; Klutmann, Susanne; Knapp, Wolfram H.; Zijlstra, Josee M.; Bockisch, Andreas; Weckesser, Matthias; Lorenz, Reinhard; Schreckenberger, Mathias; Bares, Roland; Eich, Hans T.; Mueller, Rolf-Peter; Fuchs, Michael; Borchmann, Peter; Schicha, Harald; Diehl, Volker

    2008-01-01

    In the HD15 trial of the German Hodgkin Study Group, the negative predictive value (NPV) of positron emission tomography (PET) using [18F]-fluorodeoxyglucose in advanced-stage Hodgkin lymphoma (HL) was evaluated. A total of 817 patients were enrolled and randomly assigned to receive BEACOPP-based chemotherapy. After completion of chemotherapy, residual disease measuring more than or equal to 2.5 cm in diameter was assessed by PET in 311 patients. The NPV of PET was defined as the proportion of PET− patients without progression, relapse, or irradiation within 12 months after PET review panel. The progression-free survival was 96% for PET− patients (95% confidence interval [CI], 94%-99%) and 86% for PET+ patients (95% CI, 78%-95%, P = .011). The NPV for PET in this analysis was 94% (95% CI, 91%-97%). Thus, consolidation radiotherapy can be omitted in PET− patients with residual disease without increasing the risk for progression or early relapse compared with patients in complete remission. The impact of this finding on the overall survival at 5 years must be awaited. Until then, response adapted therapy guided by PET for HL patients seems to be a promising approach that should be further evaluated in clinical trials. This trial is registered at http://isrctn.org study as #ISRCTN32443041. PMID:18757777

  17. Positron emission tomography wrist detector

    DOEpatents

    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.

  18. Correlation of Positron Emission Tomography/Computed Tomography Scan with Smoking, Tumor Size, Stage and Differentiation in Head and Neck Cancer Patients

    PubMed Central

    Pleitz, Jordan L.; Sinha, Partha; Dressler, Emily V.; Aouad, Rony K.

    2017-01-01

    The goal of this study was to identify associations between positron emission tomography/computed tomography (PET/CT) maximum standardized uptake value (SUVmax) in patients presenting with head and neck squamous cell carcinoma (SCC) with tumor site, size, histologic differentiation, smoking, and diabetes. Charts of patients with oropharyngeal and laryngeal SCC who underwent 18F-fluorodeoxyglucose PET/CT scans were reviewed between May 2007 and August 2013. Statistical analyses included modeling log-transformed SUVmax values by tumor site, size, histologic differentiation, smoking status, and diabetes using unadjusted linear regressions. Differences were considered statistically significant for P< 0.05. A total of 111 patients (54 with oropharynx and 57 with larynx cancers) were included, 83 men and 28 women with an average age of 57.5 years old. There was a significantly higher pack-year smoking history (P = 0.005) in the larynx cancer group. While tumor T-stage was found to be significantly different (P < 0.0001), there was no difference in tumor size between the two groups: 3.16 cm and 3.58 cm in the oropharynx and larynx, respectively (P = 0.55). In the oropharynx cohort, SUVmax was associated with both tumor size (P = 0.0001) and stage (P < 0.0002). Interestingly, SUVmax differed by tumor differentiation in the larynx (P = 0.04) but not the oropharynx (P = 0.71). Finally, there was no significant difference in SUVmax relative to diabetes and smoking status. PET/CT SUVmax correlated with both tumor size and stage in oropharyngeal cancer patients, and it correlated only with tumor differentiation but not the size or stage in the larynx. There were no significant differences in SUVmax by diabetes or smoking status. PMID:28217020

  19. Can Positron Emission Tomography/Computed Tomography with the Dual Tracers Fluorine-18 Fluoroestradiol and Fluorodeoxyglucose Predict Neoadjuvant Chemotherapy Response of Breast Cancer? ----A Pilot Study

    PubMed Central

    Yang, Zhongyi; Sun, Yifei; Xue, Jing; Yao, Zhifeng; Xu, Junyan; Cheng, Jingyi; Shi, Wei; Zhu, Beiling; Zhang, Yongping; Zhang, Yingjian

    2013-01-01

    Objective To assess the clinical value of dual tracers Positron emission tomography/computed tomography (PET/CT) 18F-fluoroestradiol (18F-FES) and 18F-fluorodeoxyglucose (18F-FDG) in predicting neoadjuvant chemotherapy response (NAC) of breast cancer. Methods Eighteen consecutive patients with newly diagnosed, non-inflammatory, stage II and III breast cancer undergoing NAC were included. Before chemotherapy, they underwent both 18F-FES and 18F-FDG PET/CT scans. Surgery was performed after three to six cycles of chemotherapy. Tumor response was graded and divided into two groups: the responders and non-responders. We used the maximum standardized uptake value (SUVmax) to qualify each primary lesion. Results Pathologic analysis revealed 10 patients were responders while the other 8 patients were non-responders. There was no statistical difference of SUVmax-FDG and tumor size between these two groups (P>0.05). On the contrary, SUVmax-FES was lower in responders (1.75±0.66 versus 4.42±1.14; U=5, P=0.002); and SUVmax-FES/FDG also showed great value in predicting outcome (0.16±0.06 versus 0.54±0.22; U=5, P=0.002). Conclusions Our study showed 18F-FES PET/CT might be feasible to predict response of NAC. However, whether the use of dual tracers 18F-FES and 18F-FDG has complementary value should be further studied. PMID:24205151

  20. The Correlation Between Pre-treatment Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters and Clinical Prognostic Factors in Pediatric Hodgkin Lymphoma

    PubMed Central

    Tatcı, Ebru; Uslu Biner, İnci; Emir, Suna; Tanyıldız, Hikmet Gülşah; Özmen, Özlem; Alagöz, Engin; Gökçek, Atila; Şahin, Gürses

    2017-01-01

    Objective: To compare standardized uptake values (SUV) derived from pre-treatment 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging and clinical prognostic factors in pediatric patients with Hodgkin lymphoma (HL). Methods: Pre-treatment FDG PET/CT findings of 28 children with HL were evaluated in this retrospective study. Metabolic tumor volume (MTV), SUVmax normalized by weight (SUVweight), lean body mass (SUVlbm), body surface area (SUVbsa) and plasma glucose levels of tumors (SUVglucose) were calculated using pre-treatment FDG PET/CT scan images. These metabolic parameters were correlated with clinical factors [age, sex, number of lymph node groups, presence of splenic involvement, bulky mediastinal disease, Ann Arbor stage, serum white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), serum albumin and hemoglobin levels]. Results: SUVbsa, SUVlbm, SUVweight, SUVglucose and MTV were higher in patients with stage III-IV disease, bulky tumor and ≥3 lymph node groups (p<0.05). SUVbsa and SUVglucose were higher in patients with splenic involvement (p<0.05). There was no significant correlation between these metabolic parameters and sex, ESR, levels of albumin and WBC (p>0.05). SUVbsa and SUVlbm were higher in patients with anemia (p<0.05). Additionally, significant increases were detected in SUVweight, MTV, and SUVglucose with increasing age (p=0.005, p=0.027, and p=0.009, respectively). SUVbsa and SUVlbm had no significant correlation with age (p>0.05). Conclusion: Metabolic parameters derived from pre-treatment FDG PET/CT may have an important role in predicting high-risk disease in patients with HL. Also, SUVbsa and SUVlbm may be better markers than SUVweight in the quantitative evaluation of FDG PET/CT scans in pediatric patients. PMID:28291005

  1. Addiction Studies with Positron Emission Tomography

    ScienceCinema

    Joanna Fowler

    2016-07-12

    Brookhaven scientist Joanna Fowler describes Positron Emission Technology (PET) research at BNL which for the past 30 years has focused in the integration of basic research in radiotracer chemistry with the tools of neuroscience to develop new scientific

  2. Addiction Studies with Positron Emission Tomography

    SciTech Connect

    Joanna Fowler

    2008-10-13

    Brookhaven scientist Joanna Fowler describes Positron Emission Technology (PET) research at BNL which for the past 30 years has focused in the integration of basic research in radiotracer chemistry with the tools of neuroscience to develop new scientific

  3. Imaging local brain function with emission computed tomography

    SciTech Connect

    Kuhl, D.E.

    1984-03-01

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

  4. Positron annihilation induced Auger electron emission

    SciTech Connect

    Weiss, A.; Jibaly, M.; Lei, Chun; Mehl, D.; Mayer, R.; Lynn, K.G.

    1988-01-01

    We report on measurements of Auger electron emission from Cu and Fe due to core hole excitations produced by the removal of core electrons by matter-antimatter annihilation. Estimates are developed of the probability of positrons annihilating with a 3p electron in these materials. Several important advantages of Positron annihilation induced Auger Electron Spectroscopy (PAES) for surface analysis are suggested. 10 refs., 2 figs.

  5. Advanced Instrumentation for Positron Emission Tomography [PET

    DOE R&D Accomplishments Database

    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.

  6. Advanced instrumentation for Positron Emission Tomography

    SciTech Connect

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

    1985-04-01

    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.

  7. Positron emission tomography - a new approach to brain chemistry

    SciTech Connect

    Jacobson, H.G.

    1988-11-11

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

  8. Positron emission tomography: An overview

    PubMed Central

    Shukla, A. K.; Kumar, Utham

    2006-01-01

    The rate of glucose utilization in tumor cells is significantly enhanced as compared to normal cells and this biochemical characteristic is utilized in PET imaging using FDG as a major workhorse. The PET systems as well as cyclotrons producing positron emitting radiopharmaceuticals have undergone continuous technological refinements. While PET (CT) systems enable fusion images as well as precise attenuation correction, the self-shielded cyclotrons developed provide dedicated systems for in-house production of a large number of PET radiopharmaceuticals. The application of PET images in oncology includes those of pulmonary, colorectal, breast, lymphoma, head & neck, bone, ovarian and GI cancers. The PET has been recognized as promising diagnostic tool to predict biological and physiological changes at the molecular level and hence offer a potential area for future applications including Stem Cell research. PMID:21206635

  9. Positron Emission Tomography Imaging of Hypoxia

    PubMed Central

    Lapi, Suzanne E.; Voller, Thomas F.; Welch, Michael J.

    2009-01-01

    Synopsis Hypoxia imaging has applications in functional recovery in ischemic events such as stroke and myocardial ischemia, but especially in tumors in which hypoxia can be predictive of treatment response and overall prognosis. Recently there has been development of imaging agents utilizing positron emission tomography for non-invasive imaging of hypoxia. Many of these PET agents have come to the forefront of hypoxia imaging. Halogenated PET nitroimidazole imaging agents labeled with 18F (t1/2 = 110 m) and 124I (t1/2 = 110 m) have been under investigation for the last 25 years, with radiometal agents (64Cu-ATSM) being developed more recently. This review focuses on these positron emission tomography imaging agents for hypoxia. PMID:20046923

  10. Imaging Prostate Cancer with Positron Emission Tomography

    DTIC Science & Technology

    2014-07-01

    AD_________________ Award Number: W81XWH-13-1-0125 TITLE: Imaging Prostate Cancer with Positron Emission Tomography...ABOVE ADDRESS. 1. REPORT DATE 2014 2. REPORT TYPE Annual 3. DATES COVERED 01 Sept 2013-31 Aug 2014 4. TITLE AND SUBTITLE Imaging Prostate Cancer ...proposal is to develop peptide based radiopharmaceuticals and evaluate them as PET imaging agents in preclinical animal models of prostate cancer

  11. Feasibility study for positron emission mammography.

    PubMed

    Thompson, C J; Murthy, K; Weinberg, I N; Mako, F

    1994-04-01

    A feasibility study is presented for a small, low-cost, dedicated device for positron emission mammography. Two detector arrays above and below the breast would be placed in a conventional mammography unit. These detectors are sensitive to positron annihilation radiation, and are connected to a coincidence circuit and a multiplane image memory. Images of the distribution of positron-emitting isotope are obtained in real time by incrementing the memory location at the intersection of each line of response. Monte Carlo simulations of a breast phantom are compared with actual scans of this phantom in a conventional PET scanner. The simulations and experimental data are used to predict the performance of the proposed system. Spatial resolution experiments using very narrow bismuth germanate BGO crystals suggest that spatial resolutions of about 2 mm should be possible. The efficiency of the proposed device is about ten times that of a conventional brain scanner. The scatter fraction is greater, but the scattered radiation has a very flat distribution. By designing the device to fit in an existing mammography unit, conventional mammograms can be taken after the injection of the radio-pharmaceutical allowing exact registration of the emission and conventional mammographic images.

  12. A New Brain Positron Emission Tomography Scanner With Semiconductor Detectors for Target Volume Delineation and Radiotherapy Treatment Planning in Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Katoh, Norio; Yasuda, Koichi; Shiga, Tohru; Hasegawa, Masakazu; Onimaru, Rikiya; Shimizu, Shinichi; Bengua, Gerard; Ishikawa, Masayori; Tamaki, Nagara; Shirato, Hiroki

    2012-03-15

    Purpose: We compared two treatment planning methods for stereotactic boost for treating nasopharyngeal carcinoma (NPC): the use of conventional whole-body bismuth germanate (BGO) scintillator positron emission tomography (PET{sub CONV}WB) versus the new brain (BR) PET system using semiconductor detectors (PET{sub NEW}BR). Methods and Materials: Twelve patients with NPC were enrolled in this study. [{sup 18}F]Fluorodeoxyglucose-PET images were acquired using both the PET{sub NEW}BR and the PET{sub CONV}WB system on the same day. Computed tomography (CT) and two PET data sets were transferred to a treatment planning system, and the PET{sub CONV}WB and PET{sub NEW}BR images were coregistered with the same set of CT images. Window width and level values for all PET images were fixed at 3000 and 300, respectively. The gross tumor volume (GTV) was visually delineated on PET images by using either PET{sub CONV}WB (GTV{sub CONV}) images or PET{sub NEW}BR (GTV{sub NEW}) images. Assuming a stereotactic radiotherapy boost of 7 ports, the prescribed dose delivered to 95% of the planning target volume (PTV) was set to 2000 cGy in 4 fractions. Results: The average absolute volume ({+-}standard deviation [SD]) of GTV{sub NEW} was 15.7 ml ({+-}9.9) ml, and that of GTV{sub CONV} was 34.0 ({+-}20.5) ml. The average GTV{sub NEW} was significantly smaller than that of GTV{sub CONV} (p = 0.0006). There was no statistically significant difference between the maximum dose (p = 0.0585) and the mean dose (p = 0.2748) of PTV. The radiotherapy treatment plan based on the new gross tumor volume (PLAN{sub NEW}) significantly reduced maximum doses to the cerebrum and cerebellum (p = 0.0418) and to brain stem (p = 0.0041). Conclusion: Results of the present study suggest that the new brain PET system using semiconductor detectors can provide more accurate tumor delineation than the conventional whole-body BGO PET system and may be an important tool for functional and molecular radiotherapy

  13. Positron emission tomography (PET) for cholangiocarcinoma

    PubMed Central

    Breitenstein, S.; Apestegui, C.

    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. Therefore, PET-CT is recommended in the preoperative staging of intrahepatic (strength of recommendation: moderate) and extrahepatic (strength of recommendation: low) CCA. PMID:18773069

  14. Positron Emission Tomography: Its 65 years

    NASA Astrophysics Data System (ADS)

    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.

  15. Positron Emission Tomography: A Basic Analysis

    NASA Astrophysics Data System (ADS)

    Kerbacher, M. E.; Deaton, J. W.; Phinney, L. C.; Mitchell, L. J.; Duggan, J. L.

    2007-10-01

    Positron Emission Tomography is useful in detecting biological abnormalities. The technique involves attaching radiotracers to a material used inside the body, in many cases glucose. Glucose is absorbed most readily in areas of unusual cell growth or uptake of nutrients so through natural processes the treated glucose highlights regions of tumors and other degenerative disorders such as Alzheimer's disease. The higher the concentration of isotopes, the more dynamic the area. Isotopes commonly used as tracers are 11C, 18F, 13N, and 15O due to their easy production and short half-lives. Once the tracers have saturated an area of tissue they are detected using coincidence detectors collinear with individual isotopes. As the isotope decays it emits a positron which, upon annihilating an electron, produces two oppositely directioned gamma rays. The PET machine consists of several pairs of detectors, each 180 degrees from their partner detector. When the oppositely positioned detectors are collinear with the area of the isotope, a computer registers the location of the isotope and can compile an image of the activity of the highlighted area based on the position and strength of the isotopes.

  16. Positron Emission Tomography of the Heart

    DOE R&D Accomplishments Database

    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.

  17. Compact conscious animal positron emission tomography scanner

    DOEpatents

    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.

  18. Tumor Quantification in Clinical Positron Emission Tomography

    PubMed Central

    Bai, Bing; Bading, James; Conti, Peter S

    2013-01-01

    Positron emission tomography (PET) is used extensively in clinical oncology for tumor detection, staging and therapy response assessment. Quantitative measurements of tumor uptake, usually in the form of standardized uptake values (SUVs), have enhanced or replaced qualitative interpretation. In this paper we review the current status of tumor quantification methods and their applications to clinical oncology. Factors that impede quantitative assessment and limit its accuracy and reproducibility are summarized, with special emphasis on SUV analysis. We describe current efforts to improve the accuracy of tumor uptake measurements, characterize overall metabolic tumor burden and heterogeneity of tumor uptake, and account for the effects of image noise. We also summarize recent developments in PET instrumentation and image reconstruction and their impact on tumor quantification. Finally, we offer our assessment of the current development needs in PET tumor quantification, including practical techniques for fully quantitative, pharmacokinetic measurements. PMID:24312151

  19. Positron Emission Tomography with improved spatial resolution

    SciTech Connect

    Drukier, A.K.

    1990-04-01

    Applied Research Corporation (ARC) proposed the development of a new class of solid state detectors called Superconducting Granular Detectors (SGD). These new detectors permit considerable improvements in medical imaging, e.g. Positron Emission Tomography (PET). The biggest impact of this technique will be in imaging of the brain. It should permit better clinical diagnosis of such important diseases as Altzheimer's or schizophrenia. More specifically, we will develop an improved PET-imager; a spatial resolution 2 mm may be achievable with SGD. A time-of-flight capability(t {approx} 100 psec) will permit better contrast and facilitate 3D imaging. In the following, we describe the results of the first 9 months of the development.

  20. Instrumentation optimization for positron emission mammography

    SciTech Connect

    Moses, William W.; Qi, Jinyi

    2003-06-05

    The past several years have seen designs for PET cameras optimized to image the breast, commonly known as Positron Emission Mammography or PEM cameras. The guiding principal behind PEM instrumentation is that a camera whose field of view is restricted to a single breast has higher performance and lower cost than a conventional PET camera. The most common geometry is a pair of parallel planes of detector modules, although geometries that encircle the breast have also been proposed. The ability of the detector modules to measure the depth of interaction (DOI) is also a relevant feature. This paper finds that while both the additional solid angle coverage afforded by encircling the breast and the decreased blurring afforded by the DOI measurement improve performance, the ability to measure DOI is more important than the ability to encircle the breast.

  1. Recent Developments in Positron Emission Tomography (PET) Instrumentation

    DOE R&D Accomplishments Database

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

    1986-04-01

    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.

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

    SciTech Connect

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

    1986-04-01

    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.

  3. Use of micro-positron emission tomography with 18F-fallypride to measure the levels of dopamine receptor-D2 and 18F-FDG as molecular imaging tracer in the pituitary glands and prolactinomas of Fischer-344 rats

    PubMed Central

    Li, Ping; Gui, Songbai; Cao, Lei; Gao, Hua; Bai, Jiwei; Li, Chuzhong; Zhang, Yazhuo

    2016-01-01

    Dopamine receptor-D2 (DRD2) is the most important drug target in prolactinoma. The aim of this current study was to investigate the role of using micro-positron emission tomography (micro-PET) with 18F-fallypride and 18F-fluorodeoxyglucose (18F-FDG) as molecular imaging tracer in the pituitary glands and prolactinomas of Fischer-344 (F344) rats and detect the difference of the levels of DRD2 in the pituitary glands and prolactinomas of F344 rat prolactinoma models. Female F344 rat prolactinoma models were established by subcutaneous administration of 15 mg 17β-estradiol for 8 weeks. The growth of tumors was monitored by the small-animal magnetic resonance imaging and micro-PET. A series of molecular biological experiments were also performed 4 and 6 weeks after pump implantation. The micro-PET molecular imaging with 18F-fallypride revealed a decreased expression of DRD2 in F344 rat prolactinoma models, but the micro-PET molecular imaging with 18F-FDG presented an increased uptake in the prolactinoma compared with the pituitary gland. A decreasing trend of levels of DRD2 in F344 rat prolactinoma models was also detected by molecular biological experiments. From this, we can conclude that micro-PET with 18F-fallypride and 18F-FDG can be used to assess tumorigenesis of the prolactinomas in vivo and molecular imaging detection of DRD2 level in prolactinoma may be an indication of treatment effect in the animal experiment. PMID:27103832

  4. Data acquisition with a positron emission tomograph

    SciTech Connect

    Freifelder, R.; Karp, J.S.

    1997-12-31

    Positron Emission Tomography (PET) is a clinical imaging modality used in Nuclear Medicine. PET measures functionality rather than anatomical features and is therefore invaluable in the treatment of diseases which are characterized by functional changes in organs rather than anatomical changes. Typical diseases for which PET is used are cancer, epilepsy, and heart disease. While the scanners are not very complex, the performance demands on the devices are high. Excellent spatial resolution, 4-5 mm, and high sensitivity are key to maintaining high image quality. Compensation or suppression of scattered radiation is also necessary for good image quality. The ability to acquire data under high counting rates is also necessary in order to minimize the injected dose to the patient, minimize the patient`s time in the scanner, and finally to minimize blurring due to patient motion. We have adapted various techniques in our data acquisition system which will be reported on in this talk. These include pulse clipping using lumped delay lines, flash ADCs with short sampling time, the use of a local positioning algorithm to limit the number of data words being used in subsequent second level software triggers and calculations, and finally the use of high speed dedicated calculator boards for on-line rebinning and reduction of the data. Modifications to the system to allow for transmission scanning will also be discussed.

  5. Amorphous silicon detectors in positron emission tomography

    SciTech Connect

    Conti, M. Lawrence Berkeley Lab., CA ); Perez-Mendez, V. )

    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.

  6. The Role of Chemistry in Positron Emission Tomography.

    ERIC Educational Resources Information Center

    Feliu, Anthony L.

    1988-01-01

    Investigates use of positron emission tomography (PET) to study in-vivo metabolic processes. Discusses methodology of PET and medical uses. Outlines the production of different radioisotopes used in PET radiotracers. Includes selected bibliography. (ML)

  7. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    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.

  8. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FbG) 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.

  9. Primary Tumor Standardized Uptake Value Measured on F18-Fluorodeoxyglucose Positron Emission Tomography Is of Prediction Value for Survival and Local Control in Non–Small-Cell Lung Cancer Receiving Radiotherapy

    PubMed Central

    Na, Feifei; Wang, Jingwen; Li, Cong; Deng, Lei; Xue, Jianxin

    2014-01-01

    Introduction: The 2-[18F]-Fluorodeoxyglucose (FDG) positron emission tomography (PET/CT) has become an imaging tool for clinical assessment of tumor, node, metastasis in non–small-cell lung cancer (NSCLC). Primary tumor maximum standardized uptake value (SUVmax) on 18F-FDG PET/CT before and after radiation therapy (RT) has been studied as a potential prognostic factor for NSCLC patients receiving radiotherapy. However, the sample sizes of most studies were small, and the results of the prediction value of SUVmax remained undetermined, which lead us to perform a meta-analysis to improve the precision in estimating its effect. Methods: We performed a meta-analysis of published literature for primary tumor SUVmax-based biomarkers of the outcome of NSCLC receiving radiotherapy. The required data for estimation of individual hazard ratios (HRs) to compare patients with a low and a high SUVmax were extracted from each publication. A combined HR was calculated by Stata statistical software (Version 11). All of the results were verified by two persons to ensure its accuracy. Results: Thirteen studies were finally included into this meta-analysis; data are available in 13 studies for pre-RT primary tumor SUVmax and in five studies for post-RT. For overall survival, the combined HR estimate was 1.05 (95% confidence interval [CI], 1.02–1.08) and 1.32 (95% CI, 1.15–1.51) for pre-RT SUVmax and post-RT SUVmax, respectively; 1.26 (95% CI, 1.05–1.52) and 2.01 (95% CI, 1.16–3.46) for local control (LC). In stereotactic body radiotherapy (SBRT) group, HR for LC was 1.11 (95% CI, 1.06–1.18) and 2.19 (95% CI, 1.34–3.60) for pre-SBRT SUVmax and post-SBRT SUVmax, respectively. Conclusion: Both pre-RT and post-RT primary tumor SUVmax can predict the outcome of patients with NSCLC treated with radiotherapy. Patients with high levels of pre-RT SUVmax seemed to have poorer overall survival and LC. PMID:24787963

  10. Cervical Gross Tumor Volume Dose Predicts Local Control Using Magnetic Resonance Imaging/Diffusion-Weighted Imaging—Guided High-Dose-Rate and Positron Emission Tomography/Computed Tomography—Guided Intensity Modulated Radiation Therapy

    SciTech Connect

    Dyk, Pawel; Jiang, Naomi; Sun, Baozhou; DeWees, Todd A.; Fowler, Kathryn J.; Narra, Vamsi; Garcia-Ramirez, Jose L.; Schwarz, Julie K.; Grigsby, Perry W.

    2014-11-15

    Purpose: Magnetic resonance imaging/diffusion weighted-imaging (MRI/DWI)-guided high-dose-rate (HDR) brachytherapy and {sup 18}F-fluorodeoxyglucose (FDG) — positron emission tomography/computed tomography (PET/CT)-guided intensity modulated radiation therapy (IMRT) for the definitive treatment of cervical cancer is a novel treatment technique. The purpose of this study was to report our analysis of dose-volume parameters predicting gross tumor volume (GTV) control. Methods and Materials: We analyzed the records of 134 patients with International Federation of Gynecology and Obstetrics stages IB1-IVB cervical cancer treated with combined MRI-guided HDR and IMRT from July 2009 to July 2011. IMRT was targeted to the metabolic tumor volume and lymph nodes by use of FDG-PET/CT simulation. The GTV for each HDR fraction was delineated by use of T2-weighted or apparent diffusion coefficient maps from diffusion-weighted sequences. The D100, D90, and Dmean delivered to the GTV from HDR and IMRT were summed to EQD2. Results: One hundred twenty-five patients received all irradiation treatment as planned, and 9 did not complete treatment. All 134 patients are included in this analysis. Treatment failure in the cervix occurred in 24 patients (18.0%). Patients with cervix failures had a lower D100, D90, and Dmean than those who did not experience failure in the cervix. The respective doses to the GTV were 41, 58, and 136 Gy for failures compared with 67, 99, and 236 Gy for those who did not experience failure (P<.001). Probit analysis estimated the minimum D100, D90, and Dmean doses required for ≥90% local control to be 69, 98, and 260 Gy (P<.001). Conclusions: Total dose delivered to the GTV from combined MRI-guided HDR and PET/CT-guided IMRT is highly correlated with local tumor control. The findings can be directly applied in the clinic for dose adaptation to maximize local control.

  11. Positron emission tomographic imaging of tumors using monoclonal antibodies

    SciTech Connect

    Zalutsky, M.R.

    1992-08-01

    This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.

  12. 77 FR 71802 - Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ... ``Investigational New Drug Applications for Positron Emission Tomography (PET) Drugs.'' The guidance is intended to assist manufacturers of PET drugs in submitting investigational new drug applications (INDs). DATES... guidance entitled ``Investigational New Drug Applications for Positron Emission Tomography (PET)...

  13. Positron Emission Tomography: Human Brain Function and Biochemistry.

    ERIC Educational Resources Information Center

    Phelps, Michael E.; Mazziotta, John C.

    1985-01-01

    Describes the method, present status, and application of positron emission tomography (PET), an analytical imaging technique for "in vivo" measurements of the anatomical distribution and rates of specific biochemical reactions. Measurements and image dynamic biochemistry link basic and clinical neurosciences with clinical findings…

  14. Positron emission tomography: the conceptual idea using a multidisciplinary approach.

    PubMed

    Paans, Anne M J; van Waarde, Aren; Elsinga, Philip H; Willemsen, Antoon T M; Vaalburg, Willem

    2002-07-01

    Positron emission tomography (PET) is a method for quantitatively measuring biochemical and physiological processes in vivo by using radiopharmaceuticals labeled with positron-emitting radionuclides such as 11C, 13N, 15O, and 18F and by measuring the annihilation radiation using a coincidence technique. This technique is also used for measurement of the pharmacokinetics of labeled drugs and measurement of the effects of drugs on metabolism. Deviations from normal metabolism can be measured and insight into biological processes responsible for diseases can be obtained.

  15. Pure hemidystonia with basal ganglion abnormalities on positron emission tomography

    SciTech Connect

    Perlmutter, J.S.; Raichle, M.E.

    1984-03-01

    We present a patient with hemidystonia and an abnormality of the contralateral basal ganglion seen only with positron emission tomography. A 50-year-old sinistral man suffered minor trauma to the right side of his head and neck. Within 20 minutes he developed paroxysmal intermittent dystonic posturing of his right face, forearm, hand, and foot, with weaker contractions of the left foot, lasting several seconds and recurring every few minutes. Neurological findings between spells were normal. The following were also normal: electrolyte, calcium, magnesium, and arterial blood gas levels, and findings of drug screen, cerebrospinal fluid examination, electroencephalography with nasopharyngeal leads, computed tomographic scanning (initially and four weeks later), and cerebral angiography. Positron emission tomographic scanning revealed abnormalities in the left basal ganglion region, including decreased oxygen metabolism, decreased oxygen extraction, increased blood volume, and increased blood flow.

  16. Technology related parameters affecting quantification in positron emission tomography imaging.

    PubMed

    Visvikis, D; Turzo, A; Bizais, Y; Cheze-Le Rest, C

    2004-07-01

    Some of the issues associated with positron emission tomography (PET) technology which still pose challenges for the recovery of quantitative images are discussed. Through these issues reference to what is today considered as the 'gold standard' in quantitative PET imaging is also presented. A brief comparison of 2-D and 3-D PET is given, together with a short discussion of combined PET/CT imaging devices.

  17. Current and future technological trends in positron emission tomography.

    PubMed

    Karp, J S; Freifelder, R

    1992-04-01

    Current trends in positron emission tomography (PET) instrumentation are examined, with an emphasis on providing information suitable to the prospective PET user. Basic principles underlying PET are explained and information on performance measurements, techniques, and quantitation are given in order to allow the user to compare and contrast different types of PET scanners. These scanner designs are described. Specific examples are given and the combination of PET with other modalities is discussed.

  18. Positron emission tomography in the evaluation of subdural hematomas

    SciTech Connect

    Ericson, K.; Bergstroem, M.; Eriksson, L.

    1980-12-01

    Fifteen patients with 21 subdural effusions were investigated both with transmission computer assisted tomography (CAT) and positron emission tomography (PET). The tracer in the emission studies was /sup 68/Ga-EDTA. Twelve lesions were visualized both with CAT and PET. Five lesions that were negative or doubtful on CAT were visualized with PET, whereas four lesions negative or doubtful on PET were demonstrated by CAT. The two methods complement each other due to the fact that they are based on different mechanisms: CAT mainly on attenuation of the fluid collection. PET on isotope accumulation, particularly in the hematoma membranes.

  19. Positron emission tomographic imaging of tumors using monoclonal antibodies

    SciTech Connect

    Zalutsky, M.R.

    1990-12-01

    The overall objective for this research project is to develop methods for utilizing Positron Emission Tomography (PET) to increase the clinical potential of radiolabelled monoclonal antibodies (MAbs). By labeling MAbs with positron-emitting nuclides, it should be possible to quantitate the dynamics of their three-dimensional distribution in vivo. Our long term goals are to apply this approach to investigate the following: normal tissue toxicity; radiation dose to the tumor; and early tumor imaging. The research plans of this proposal include the following specific aims: optimize labeling of MAbs with fluorine 18, bromine 76 and bromine 75; label MAb Mel-14 (reactive against human gliomas and melanomas) and its Fab and F(ab{prime}){sub 2} fragments while retaining immunoreactivity; determine the distribution of Mel-14 in athymic mice bearing human gliomas; determine pharmacokinetics of Mel-14 in nonhuman primates. Experiments with another MAb, TP-1, and iodine 124 and 131 are also planned. 8 figs.

  20. Principles and clinical applications of positron emission tomography.

    PubMed

    Gardner, S F; Green, J A; Bednarczyk, E M; Farnett, L; Miraldi, F

    1992-06-01

    The basics of positron emission tomography (PET) are presented, including the physics, instrumentation, and radiopharmaceuticals involved; the clinical and research applications; and the cost. In PET, organic molecules labeled with positron-emitting radionuclides are injected or inhaled, and the high-energy photons produced by annihilation events are detected by paired, integrated crystal detectors. A computer uses the lines of origin of these photons to reconstruct a three-dimensional map of a functioning organ system. The positron-emitting radionuclides most often used are carbon 11, oxygen 15, nitrogen 13, fluorine 18, and rubidium 82. PET imaging centers usually consist of a cyclotron facility, a radiochemistry facility, a PET scanner, and computers for image reconstruction. Radiopharmaceuticals used in PET may be divided into blood flow-imaging agents, metabolic imaging agents, and drug receptor-imaging agents. Although PET is still primarily a research tool, it has shown diagnostic potential in neurology, cardiology, and oncology. It has also shown promise as a tool for pharmacologic assessment, as in studies of the effects of the fluorinated quinolones on cerebral blood flow and glucose metabolism. PET may become important in drug development because it yields specific information relatively noninvasively. A single study carries an average break-even price tag of $1500-$2000; rigorous cost-benefit analyses should be conducted before society is asked to subsidize such costs. Positron emission tomography is a frontier technology for which valuable clinical applications are being discovered. Pharmacists can contribute enormously to PET applications and at the same time establish a unique subspecialty for the profession.

  1. [Methods and clinical applications of positron emission tomography in endocrinology].

    PubMed

    De Landsheere, C; Lamotte, D

    1990-01-01

    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 hormone-dependent 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 prolactin) 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 bromocriptine 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.

  2. Positron emission tomography for use in microdosing studies.

    PubMed

    Wagner, Claudia Christina; Müller, Markus; Lappin, Graham; Langer, Oliver

    2008-01-01

    Positron emission tomography (PET) imaging using microdoses of radiolabeled drug tracers is gaining increasing acceptance in modern clinical drug development. This approach is unique in that it allows for direct quantitative assessment of drug concentrations in the tissues targeted for treatment, thereby bridging the gap between pharmacokinetics and pharmacodynamics. Current applications of PET in anticancer, anti-infective and central nervous system drug research are reviewed herein. Situated at the interface of preclinical and clinical drug testing, PET microdosing is a powerful and highly innovative tool for pharmaceutical development.

  3. Direct conversion semiconductor detectors in positron emission tomography

    NASA Astrophysics Data System (ADS)

    Cates, Joshua W.; Gu, Yi; Levin, Craig S.

    2015-05-01

    Semiconductor detectors are playing an increasing role in ongoing research to improve image resolution, contrast, and quantitative accuracy in preclinical applications of positron emission tomography (PET). These detectors serve as a medium for direct detection of annihilation photons. Early clinical translation of this technology has shown improvements in image quality and tumor delineation for head and neck cancers, relative to conventional scintillator-based systems. After a brief outline of the basics of PET imaging and the physical detection mechanisms for semiconductor detectors, an overview of ongoing detector development work is presented. The capabilities of semiconductor-based PET systems and the current state of these devices are discussed.

  4. [Positron emission tomography: diagnostic imaging on a molecular level].

    PubMed

    Allemann, K; Wyss, M; Wergin, M; Bley, C Rohrer; Ametamay, S; Bruehlmeier, M; Kaser-Hotz, B

    2004-08-01

    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.

  5. Positron Emission Tomography (PET) for benign and malignant disease

    PubMed Central

    Visioni, Anthony; Kim, Julian

    2011-01-01

    Synopsis Functional imaging using radiolabeled probes which specifically bind and accumulate in target tissues has improved the sensitivity and specificity of conventional imaging. Positron Emission Tomography using modified glucose probes (FDG-PET) has demonstrated improved diagnostic accuracy in differentiating benign from malignant lesions in the setting of solitary pulmonary nodules. In addition, FDG-PET has become a useful modality in pre-operative staging of patients with lung cancer and is being tested with many other malignancies for its ability to change patient management. This article provides an overview of the current status of FDG-PET and presents the challenges of moving towards routine use. PMID:21184913

  6. Role of positron emission tomography/computed tomography in dementia.

    PubMed

    Hinds, Sidney R; Stocker, Derek J; Bradley, Yong C

    2013-09-01

    This article provides a clinically based review of positron emission tomography (PET) imaging for dementia. Significant advances in nuclear medicine and molecular imaging techniques have improved the understanding of the genetic and molecular processes that define neurodegenerative dementia diseases. Metabolic imaging remains constant in its ability to document neuronal loss and lost function. Amyloid-β radiotracers are useful in documenting amyloid deposition, differentiating origins of dementia and possibly predicting disease progression. These radiotracers may be useful in diagnosis-specific treatment. PET radiotracers have increased sensitivity and specificity to complement clinical presentation and other adjunct testing in the evaluation of dementia.

  7. The McMaster positron emission tomograph: Design and evaluation

    NASA Astrophysics Data System (ADS)

    Nahmias, Claude

    1984-03-01

    The McMaster positron emission tomograph is an instrument designed for the high resolution, cross sectional study of the human brain. The detector head comprises 160 bismuth germanate crystals, each coupled to a 12.7 mm photomultiplier tube, closely packed on a ring, 53.5 cm in diameter. The tomographic slices examined are either 10 or 20 mm thick. The spatial resolution is 8 mm (fwhm) in the stationary mode. The sensitivity is 16 000 cps/μCi/cc for a 10 mm slice. The instrument has been in clinical use for the past 18 months.

  8. Positron emission tomography: physics, instrumentation, and image analysis.

    PubMed

    Porenta, G

    1994-01-01

    Positron emission tomography (PET) is a noninvasive diagnostic technique that permits reconstruction of cross-sectional images of the human body which depict the biodistribution of PET tracer substances. A large variety of physiological PET tracers, mostly based on isotopes of carbon, nitrogen, oxygen, and fluorine is available and allows the in vivo investigation of organ perfusion, metabolic pathways and biomolecular processes in normal and diseased states. PET cameras utilize the physical characteristics of positron decay to derive quantitative measurements of tracer concentrations, a capability that has so far been elusive for conventional SPECT (single photon emission computed tomography) imaging techniques. Due to the short half lives of most PET isotopes, an on-site cyclotron and a radiochemistry unit are necessary to provide an adequate supply of PET tracers. While operating a PET center in the past was a complex procedure restricted to few academic centers with ample resources, PET technology has rapidly advanced in recent years and has entered the commercial nuclear medicine market. To date, the availability of compact cyclotrons with remote computer control, automated synthesis units for PET radiochemistry, high-performance PET cameras, and user-friendly analysis workstations permits installation of a clinical PET center within most nuclear medicine facilities. This review provides simple descriptions of important aspects concerning physics, instrumentation, and image analysis in PET imaging which should be understood by medical personnel involved in the clinical operation of a PET imaging center.

  9. Neutrino emissivity from electron-positron annihilation in hot matter in a strong magnetic field

    SciTech Connect

    Amsterdamski, P.; Haensel, P. )

    1990-10-15

    The neutrino emissivity due to electron-positron annihilation in a strong magnetic field is computed. A strong magnetic field can significantly increase the neutrino emissivity at {ital T}{similar to}10{sup 9} K.

  10. Photon shielding for a positron emission tomography suite.

    PubMed

    Courtney, J C; Mendez, P; Hidalgo-Salvatierra, O; Bujenovic, S

    2001-08-01

    This paper provides information on the effects of distance and attenuation in lead sheet and gypsum board of the 0.511 MeV photon produced by positron annihilation. Exposure rates are projected external to an adult injected with 185 MBq (5 mCi) of 18F in a fluorodeoxyglucose solution and for the same activity in a small unshielded container. These data have been applied to estimate the shielding requirements for the Positron Emission Tomography (PET) suite operated by the Nuclear Medicine Department of Our Lady of the Lake Regional Medical Center. To assure that exposures are as low as reasonably achievable, lead was added to the walls of the room where the 18F is stored, handled, and injected into the patients. The PET scanner is installed in a room that formerly contained a Computerized Axial Tomography scanner; the existing 1.6 mm of lead sheet was left in place even though it is not required for personnel protection. During the initial phase of operation, a shield test program was conducted to estimate annual exposures to personnel inside and outside the suite. Projection of measured rates over a year of operation demonstrate that whole body doses are well below regulatory limits.

  11. Positron Emission Tomography Application to Drug Development and Research

    NASA Astrophysics Data System (ADS)

    Salvadori, Piero A.

    The research for the identification and development of new drugs represents a very complex process implying long times and massive investments. This process was not able to parallel the rate of discoveries made in the field of genomic and molecular biology and a gap created between demand of new drugs and the ability of pharmaceutical companies to select good candidates. Positron Emission Tomography, among the different Molecular Imaging modalities, could represent a new tool for the early assessment and screening of new drug candidates and, due to its physical performances and the characteristics of positron-labeled tracers, gain the role of "Biomarker" accepted by the Companies and the Regulatory Bodies of Drug Agencies. To fulfil this task PET has to exploit all of its special features such as data absolute quantification and modelling, high spatial resolution and dynamic imaging. Relevant efforts need to be directed to the careful design and validation of experimental protocols with the main goal of achieving consistency in multi- centric trials.

  12. Microdosing studies in humans: the role of positron emission tomography.

    PubMed

    Bauer, Martin; Wagner, Claudia Christina; Langer, Oliver

    2008-01-01

    Positron emission tomography (PET)-microdosing comprises the administration of a carbon-11- or fluorine-18-labelled drug candidate to human subjects in order to describe the drug's concentration-time profile in body tissues targeted for treatment. As PET microdosing involves the administration of only microgram amounts of unlabelled drug, the potential toxicological risk to human subjects is very limited. Consequently, regulatory authorities require reduced preclinical safety testing as compared with conventional phase 1 studies. Microdose studies are gaining increasing importance in clinical drug research as they have the potential to shorten time-lines and cut costs along the critical path of drug development. Current applications of PET in anticancer, anti-infective and CNS system drug research are reviewed.

  13. Studies of the brain cannabinoid system using positron emission tomography

    SciTech Connect

    Gatley, S.J.; Volkow, N.D.

    1995-10-01

    Studies using radiolabeled psychoactive drugs in conjunction with positron emission tomography (PET) have permitted the imaging of binding sites in the human brain. Similar studies of marijuana have been hampered by the unsuitability of radiolabeled THC for PET studies, and the current unavailability of other in vivo imaging agents for cannabinoid receptors. Recent developments in medicinal chemistry suggest that a PET radiotracer for cannabinoid receptors will soon become available. This chapter briefly reviews these developments, together with the results of PET studies of the effects of marijuana and other abused drugs on brain metabolism. It also reviews PET studies of cocaine binding sites, to demonstrate the kind of investigations that will be possible when a cannabinoid receptor PET radioligand becomes available.

  14. Positron Emission Tomography: state of the art and future developments

    NASA Astrophysics Data System (ADS)

    Pizzichemi, M.

    2016-08-01

    Positron emission tomography (PET) plays a fundamental role in medical imaging, with a wide range of applications covering, among the others, oncology, neurology and cardiology. PET has undergone a steady technological evolution since its introduction in mid 20th century, from the development of 3D PET in the late 1980s, to the invention of PET/CT in the 1990s and more recently with the introduction of PET/MR scanners. The current research topics aiming to develop the next generation of PET scanners are summarized in this paper, focusing on the efforts to increase the sensitivity of the detectors, as long as improving their timing, spatial and energy resolutions, with the final goal of reducing the amount of radioactive dose received by the patients and the duration of the exams while improving at the same time the detectability of lesions.

  15. A Review on Segmentation of Positron Emission Tomography Images

    PubMed Central

    Foster, Brent; Bagci, Ulas; Mansoor, Awais; Xu, Ziyue; Mollura, Daniel J.

    2014-01-01

    Positron Emission Tomography (PET), a non-invasive functional imaging method at the molecular level, images the distribution of biologically targeted radiotracers with high sensitivity. PET imaging provides detailed quantitative information about many diseases and is often used to evaluate inflammation, infection, and cancer by detecting emitted photons from a radiotracer localized to abnormal cells. In order to differentiate abnormal tissue from surrounding areas in PET images, image segmentation methods play a vital role; therefore, accurate image segmentation is often necessary for proper disease detection, diagnosis, treatment planning, and follow-ups. In this review paper, we present state-of-the-art PET image segmentation methods, as well as the recent advances in image segmentation techniques. In order to make this manuscript self-contained, we also briefly explain the fundamentals of PET imaging, the challenges of diagnostic PET image analysis, and the effects of these challenges on the segmentation results. PMID:24845019

  16. Wilson's disease studied with FDG and positron emission tomography

    SciTech Connect

    Hawkins, R.A.; Mazziotta, J.C.; Phelps, M.E.

    1987-11-01

    Four patients with Wilson's disease and eight normal controls were studied with 2-deoxy-2-(/sup 18/F)fluoro-D-glucose (FDG) and positron emission tomography (PET). The patients had diffusely reduced glucose metabolism in all brain regions evaluated compared with controls, with the exception of the thalamus. The ratio of the cerebral metabolic rate for glucose in the lenticular nuclei to hemispheres declined from 1.23 (+/- 0.14 SD) in controls to 1.03 (+/- 0.06) (p less than 0.025) in Wilson's disease patients. Compared with Huntington's disease, the PET FDG results in Wilson's disease indicate relatively less focal involvement of the caudate nucleus, more severe focal changes in the lenticular nuclei, and more significant global changes in glucose metabolism.

  17. History and future technical innovation in positron emission tomography.

    PubMed

    Jones, Terry; Townsend, David

    2017-01-01

    Instrumentation for positron emission tomography (PET) imaging has experienced tremendous improvements in performance over the past 60 years since it was first conceived as a medical imaging modality. Spatial resolution has improved by a factor of 10 and sensitivity by a factor of 40 from the early designs in the 1970s to the high-performance scanners of today. Multimodality configurations have emerged that combine PET with computed tomography (CT) and, more recently, with MR. Whole-body scans for clinical purposes can now be acquired in under 10 min on a state-of-the-art PET/CT. This paper will review the history of these technical developments over 40 years and summarize the important clinical research and healthcare applications that have been made possible by these technical advances. Some perspectives for the future of this technology will also be presented that promise to bring about new applications of this imaging modality in clinical research and healthcare.

  18. Positron emission tomography in CNS drug discovery and drug monitoring.

    PubMed

    Piel, Markus; Vernaleken, Ingo; Rösch, Frank

    2014-11-26

    Molecular imaging methods such as positron emission tomography (PET) are increasingly involved in the development of new drugs. Using radioactive tracers as imaging probes, PET allows the determination of the pharmacokinetic and pharmacodynamic properties of a drug candidate, via recording target engagement, the pattern of distribution, and metabolism. Because of the noninvasive nature and quantitative end point obtainable by molecular imaging, it seems inherently suited for the examination of a pharmaceutical's behavior in the brain. Molecular imaging, most especially PET, can therefore be a valuable tool in CNS drug research. In this Perspective, we present the basic principles of PET, the importance of appropriate tracer selection, the impact of improved radiopharmaceutical chemistry in radiotracer development, and the different roles that PET can fulfill in CNS drug research.

  19. Translational neuroimaging: positron emission tomography studies of monoamine oxidase.

    PubMed

    Fowler, Joanna S; Logan, Jean; Volkow, Nora D; Wang, Gene-Jack

    2005-01-01

    Positron emission tomography (PET) using radiotracers with high molecular specificity is an important scientific tool in studies of monoamine oxidase (MAO), an important enzyme in the regulation of the neurotransmitters dopamine, norepinephrine, and serotonin as well as the dietary amine, tyramine. MAO occurs in two different subtypes, MAO A and MAO B, which have different substrate and inhibitor specificity and which are different gene products. The highly variable subtype distribution with different species makes human studies of special value. MAO A and B can be imaged in the human brain and certain peripheral organs using PET and carbon-11 (half-life 20.4 minutes) labeled mechanism-based irreversible inhibitors, clorgyline and L -deprenyl, respectively. In this article we introduce MAO and describe the development of these radiotracers and their translation from preclinical studies to the investigation of variables affecting MAO in the human brain and peripheral organs.

  20. Tau Positron Emission Tomography (PET) Imaging: Past, Present, and Future.

    PubMed

    Ariza, Manuela; Kolb, Hartmuth C; Moechars, Dieder; Rombouts, Frederik; Andrés, José Ignacio

    2015-06-11

    Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the most common cause of dementia among the elderly population. The good correlation of the density and neocortical spread of neurofibrillary tangles (NFTs) with clinical AD disease progression offers an opportunity for the early diagnosis and staging using a noninvasive imaging technique such as positron emission tomography (PET). Thus, PET imaging of NFTs not only holds promise as a diagnostic tool but also may enable the development of disease modifying therapeutics for AD. In this review, we focus on the structural diversity of tau PET tracers, the challenges related to the identification of high affinity and highly selective NFT ligands, and recent progress in the clinical development of tau PET radioligands.

  1. Differential diagnosis of depression: relevance of positron emission tomography

    SciTech Connect

    Schwartz, J.M.; Baxter, L.R. Jr.; Mazziotta, J.C.; Gerner, R.H.; Phelps, M.E.

    1987-09-11

    The proper differential diagnosis of depression is important. A large body of research supports the division of depressive illness into bipolar and unipolar subtypes with respect to demographics, genetics, treatment response, and neurochemical mechanisms. Optimal treatment is different for unipolar and bipolar depressions. Treating a patient with bipolar depression as one would a unipolar patient may precipitate a serious manic episode or possibly even permanent rapid cycling disorder. The clinical distinction between these disorders, while sometimes difficult, can often be achieved through an increased diagnostic suspicion concerning a personal or family history of mania. Positron emission tomography and the FDG method, which allow in vivo study of the glucose metabolic rates for discrete cerebral structures, provide new evidence that bipolar and unipolar depression are two different disorders.

  2. FDG positron emission computed tomography in a study of aphasia

    SciTech Connect

    Metter, E.J.; Wasterlain, C.G.; Kuhl, D.E.; Hanson, W.R.; Phelps, M.E.

    1981-08-01

    Positron emission computed tomography (PECT) using 18F-2-fluoro-2-deoxy-D-glucose (FDG) was used to investigate the correlations between clinical status, anatomy (as described by CT), and metabolism in five patients with stable aphasia resulting from ischemic cerebral infarction. Local cerebral metabolic activity was diminished in an area larger than the area of infarction demonstrated by CT. In one patient, FDG PECT revealed a metabolic lesion that probably caused the aphasic syndrome and was not apparent by CT. The data suggest that reliance on CT in delineating the extent of the brain lesion in aphasia or other neuropsychological defects can be misleading; FDG PECT may provide important additional information. Two patients with similar metabolic lesions had very different clinical syndromes, showing that even when currently available methods are combined, major gaps remain in clinicoanatomical correlations in aphasia.

  3. Temporoparietal cortex in aphasia. Evidence from positron emission tomography

    SciTech Connect

    Metter, E.J.; Hanson, W.R.; Jackson, C.A.; Kempler, D.; van Lancker, D.; Mazziotta, J.C.; Phelps, M.E. )

    1990-11-01

    Forty-four aphasic patients were examined with (F18)-fluorodeoxyglucose positron emission tomography in a resting state to determine whether consistent glucose metabolic abnormalities were present. Ninety-seven percent of subjects showed metabolic abnormalities in the angular gyrus, 89% in the supramarginal gyrus, and 87% in the lateral and transverse superior temporal gyrus. Pearson product moment correlations were calculated between regional metabolic measures and performance on the Western Aphasia Battery. No significant correlations were found between the Western Aphasia Battery scores and right hemisphere metabolic measures. Most left hemisphere regions correlated with more than one score from the Western Aphasia Battery. Temporal but not frontal regions had significant correlations to the comprehension score. The left temporoparietal region was consistently affected in these subjects, suggesting that common features in the aphasias were caused by left temporoparietal dysfunction, while behavioral differences resulted from (1) the extent of temporoparietal changes, and (2) dysfunction elsewhere in the brain, particularly the left frontal and subcortical areas.

  4. Antiretroviral Tissue Kinetics: In Vivo Imaging Using Positron Emission Tomography▿

    PubMed Central

    Di Mascio, Michele; Srinivasula, Sharat; Bhattacharjee, Abesh; Cheng, Lily; Martiniova, Lucia; Herscovitch, Peter; Lertora, Juan; Kiesewetter, Dale

    2009-01-01

    Our current knowledge on the antiviral efficacy, dosing, and toxicity of available highly active antiretroviral therapy regimens is mostly derived from plasma or blood kinetics of anti-human immunodeficiency virus (anti-HIV) drugs. However, the blood comprises only 2% of the total target cells in the body. Tissue drug levels may differ substantially from corresponding plasma levels, and drug distribution processes may be characterized by high intertissue variability, leading to suboptimal target site concentrations and the potential risk for therapeutic failures. Positron emission tomography has greatly expanded the scope of the pharmacokinetic measurements that can be performed noninvasively in animal models or humans. We have prepared [18F]FPMPA, a fluorine-18-radiolabeled analogue of tenofovir, to study antiretroviral tissue kinetics in vivo noninvasively and tested the imaging probe in rats. The biodistribution of the fluorine-18 analogue closely follows that of nonfluorinated tenofovir. Compared to that in the blood, the levels of penetration of the antiretroviral drug were found to be significantly reduced in the spleen and submandibular lymph nodes (∼2-fold), in the mesenteric lymph nodes and the testes (∼4-fold), and in the brain compartment (∼25-fold). Intersubject variability of the trough drug concentration (measured at 120 min) in certain tissues, like the colon (coefficient of variation, >100%), is not reflected by the intersubject variability in the blood compartment (coefficient of variation, 24%). Positron emission tomography imaging of the fluorine-18 analogue revealed the accumulation of the antiretroviral drug in the cortex of the kidneys, a potential correlate of tenofovir-induced nephrotoxicity observed in HIV-1-infected treated patients. Thus, [18F]FPMPA is a promising radiotracer for evaluation of tenofovir biodistribution under carefully controlled drug administration protocols. PMID:19667288

  5. Design Study of Linear Accelerator-Based Positron Re-Emission Microscopy

    NASA Astrophysics Data System (ADS)

    Ogawa, Hiroshi; Kinomura, Atsushi; Oshima, Nagayasu; Suzuki, Ryoichi; O'Rourke, Brian E.

    In order to shorten the acquisition time of positron re-emission microscopy (PRM), a linear accelerator (LINAC)-based PRM system has been studied. The beam focusing system was designed to obtain a high brightness positron beam on the PRM sample. The beam size at the sample was calculated to be 0.8mm (FWHM), and the positron intensity within the field of view of the PRM was more than one order of magnitude higher in comparison with the previous studies.

  6. Magnetosensory function in rats: localization using positron emission tomography.

    PubMed

    Frilot, Clifton; Carrubba, Simona; Marino, Andrew A

    2009-05-01

    The aim of this study was to show that low-strength electromagnetic fields (EMFs) produced evoked potentials in rats and to localize the activated region in the brain. In response to a 2.5-G, 60-Hz stimulus, onset- and offset-evoked potentials were detected (P < 0.05 in each of the 10 animals studied); the evoked potentials had the same magnitude, latency, and nonlinear relationship to the field seen in previous studies on rabbits and human subjects. The neuroanatomical region of activation associated with the electrophysiological effect was identified by positron emission tomography using fluorodeoxyglucose. Paired emission scans (the same animal with and without field treatment) from 10 additional rats were differenced and averaged to produce a t-statistic image using the pooled variance; the t value of each voxel was compared with a calculated critical t value to identify the activated voxels (P < 0.05). A brain volume of 13 mm(3) (15 voxels) located in the posterior, central cerebellum was found to have been activated by exposure to the field. Taken together, the results indicated that magnetosensory evoked potentials in the rats were associated with increased glucose utilization in the cerebellum, thereby supporting earlier evidence that EMF transduction occurred in the brain.

  7. Cerebrospinal fluid analysis detects cerebral amyloid-β accumulation earlier than positron emission tomography.

    PubMed

    Palmqvist, Sebastian; Mattsson, Niklas; Hansson, Oskar

    2016-04-01

    Cerebral accumulation of amyloid-β is thought to be the starting mechanism in Alzheimer's disease. Amyloid-β can be detected by analysis of cerebrospinal fluid amyloid-β42 or amyloid positron emission tomography, but it is unknown if any of the methods can identify an abnormal amyloid accumulation prior to the other. Our aim was to determine whether cerebrospinal fluid amyloid-β42 change before amyloid PET during preclinical stages of Alzheimer's disease. We included 437 non-demented subjects from the prospective, longitudinal Alzheimer's Disease Neuroimaging Initiative (ADNI) study. All underwent (18)F-florbetapir positron emission tomography and cerebrospinal fluid amyloid-β42 analysis at baseline and at least one additional positron emission tomography after a mean follow-up of 2.1 years (range 1.1-4.4 years). Group classifications were based on normal and abnormal cerebrospinal fluid and positron emission tomography results at baseline. We found that cases with isolated abnormal cerebrospinal fluid amyloid-β and normal positron emission tomography at baseline accumulated amyloid with a mean rate of 1.2%/year, which was similar to the rate in cases with both abnormal cerebrospinal fluid and positron emission tomography (1.2%/year, P = 0.86). The mean accumulation rate of those with isolated abnormal cerebrospinal fluid was more than three times that of those with both normal cerebrospinal fluid and positron emission tomography (0.35%/year, P = 0.018). The group differences were similar when analysing yearly change in standardized uptake value ratio of florbetapir instead of percentage change. Those with both abnormal cerebrospinal fluid and positron emission tomography deteriorated more in memory and hippocampal volume compared with the other groups (P < 0.001), indicating that they were closer to Alzheimer's disease dementia. The results were replicated after adjustments of different factors and when using different cut-offs for amyloid-β abnormality

  8. Positron emission tomography: a first-hand experience.

    PubMed

    Traylor, J

    2000-01-01

    In July 1999, the University of Kansas Hospital installed a positron emission tomography (PET) scanner and added PET to the imaging technologies it offers patients and physicians. The new service is managed by the nuclear medicine section in the department of radiology. Plans are being implemented now to install a cyclotron in March 2000. Prior to installation of the scanner, a radiation area survey was performed in the space being considered for the PET unit. We also needed to address other critical considerations, including the manufacturer's requirements for construction of the scanner room, special electrical needs, and how the system would connect to our existing information network. It is important to work closely with your chief financial officer and chief operations officer from the beginning of the purchasing process so that these administrators have up-to-date, supportive information about PET and the progress of the installation. We made use of a variety of promotional techniques to market the new service, including broadcast e-mail, an open house for potential referring physicians, postings on the nuclear medicine Web site and communication through the local media. We also worked with the major insurance providers that utilize our hospital to educate them about PET and its benefits. In addition, we trained our own billing staff about procedures that optimize reimbursement for PET. In March 2000, University of Kansas Hospital will install the first cyclotron in the state, enabling us to generate the drugs used for PET scanning and potentially to add targets for research PET radiopharmaceuticals.

  9. Comparison of scintillators for positron emission mammography (PEM) systems

    SciTech Connect

    Raymond Raylman; Stanislaw Majewski; Mark Smith; Randolph Wojcik; Andrew Weisenberger; Brian Kross; Vladimir Popov; Jamal J. Derakhshan

    2003-02-01

    Positron emission mammography (PEM) has promise as an effective method for the detection of breast lesions. Perhaps the most significant design feature of a PEM system is the choice of scintillator material. In this investigation we compared three scintillators for use in PEM: NaI(Tl), gadolinium oxyorthosilicate (GSO), and lutetium-gadolinium oxyorthosilicate (LGSO). The PEM systems consisted of two 30/spl times/30 arrays of pixelated scintillators (3/spl times/3/spl times/10 mm/sup 3/ for GSO and LGSO and 3/spl times/3/spl times/19 mm/sup 3/ for NaI(Tl)) coupled to arrays of square position-sensitive photomultiplier tubes. The Compton scatter fraction, system energy resolution, spatial resolution, spatial resolution uniformity, and detection sensitivity were compared. Compton scatter fractions for the systems were comparable, between 8% and 9%. The NaI(Tl) system produced the best system energy resolution (18.2%), the GSO system had the worst system energy resolution (28.7%).

  10. Imaging pancreatic islet cells by positron emission tomography

    PubMed Central

    Li, Junfeng; Karunananthan, Johann; Pelham, Bradley; Kandeel, Fouad

    2016-01-01

    It was estimated that every year more than 30000 persons in the United States - approximately 80 people per day - are diagnosed with type 1 diabetes (T1D). T1D is caused by autoimmune destruction of the pancreatic islet (β cells) cells. Islet transplantation has become a promising therapy option for T1D patients, while the lack of suitable tools is difficult to directly evaluate of the viability of the grafted islet over time. Positron emission tomography (PET) as an important non-invasive methodology providing high sensitivity and good resolution, is able to accurate detection of the disturbed biochemical processes and physiological abnormality in living organism. The successful PET imaging of islets would be able to localize the specific site where transplanted islets engraft in the liver, and to quantify the level of islets remain alive and functional over time. This information would be vital to establishing and evaluating the efficiency of pancreatic islet transplantation. Many novel imaging agents have been developed to improve the sensitivity and specificity of PET islet imaging. In this article, we summarize the latest developments in carbon-11, fluorine-18, copper-64, and gallium-68 labeled radioligands for the PET imaging of pancreatic islet cells. PMID:27721939

  11. Geoscientific process monitoring with positron emission tomography (GeoPET)

    NASA Astrophysics Data System (ADS)

    Kulenkampff, Johannes; Gründig, Marion; Zakhnini, Abdelhamid; Lippmann-Pipke, Johanna

    2016-08-01

    Transport processes in geomaterials can be observed with input-output experiments, which yield no direct information on the impact of heterogeneities, or they can be assessed by model simulations based on structural imaging using µ-CT. Positron emission tomography (PET) provides an alternative experimental observation method which directly and quantitatively yields the spatio-temporal distribution of tracer concentration. Process observation with PET benefits from its extremely high sensitivity together with a resolution that is acceptable in relation to standard drill core sizes. We strongly recommend applying high-resolution PET scanners in order to achieve a resolution on the order of 1 mm. We discuss the particularities of PET applications in geoscientific experiments (GeoPET), which essentially are due to high material density. Although PET is rather insensitive to matrix effects, mass attenuation and Compton scattering have to be corrected thoroughly in order to derive quantitative values. Examples of process monitoring of advection and diffusion processes with GeoPET illustrate the procedure and the experimental conditions, as well as the benefits and limits of the method.

  12. The economics of creating a positron emission tomography center.

    PubMed

    Lissak, R J

    2000-10-01

    Positron emission tomography (PET) scanning has been a powerful research tool since its inception. Changes in the marketplace that have allowed PET to move into the clinical environment include the commercial availability of appropriate radiopharmaceuticals, reimbursement of procedures by insurance companies, and increasing awareness of physicians of the benefits of PET. Facilities that are interested in clinical PET need to develop a process to purchase equipment with an appropriate business plan. This is necessary to assure financial viability and to convince hospital administrators of the viability. The creation of a successful PET program requires an understanding of all aspects relating to a center. The process begins with reviewing the mission statement of the facility. The next step is to prepare the feasibility study, which includes reviewing the existing marketplace and determining the volume, level of referring physicians' interest, and availability of radiopharmaceuticals. Finally, an appropriate pro forma needs to be constructed to facilitate the final decision concerning the potential financial viability of such an endeavor.

  13. Usefulness of Positron Emission Tomographic Studies for Gliomas

    PubMed Central

    MIYAKE, Keisuke; OGAWA, Daisuke; OKADA, Masaki; HATAKEYAMA, Tetsuhiro; TAMIYA, Takashi

    2016-01-01

    Non-invasive positron emission tomography (PET) enables the measurement of metabolic and molecular processes with high sensitivity. PET plays a significant role in the diagnosis, prognosis, and treatment of brain tumors and predominantly detects brain tumors by detecting their metabolic alterations, including energy metabolism, amino acids, nucleic acids, and hypoxia. Glucose metabolic tracers are related to tumor cell energy and exhibit good sensitivity but poor specificity for malignant tumors. Amino acid metabolic tracers provide a better delineation of tumors and cellular proliferation. Nucleic acid metabolic tracers have a high sensitivity for malignant tumors and cellular proliferation. Hypoxic metabolism tracers are useful for detecting resistance to radiotherapy and chemotherapy. Therefore, PET imaging techniques are useful for detecting biopsy-targeting points, deciding on tumor resection, radiotherapy planning, monitoring therapy, and distinguishing brain tumor recurrence or progression from post-radiotherapy effects. However, it is not possible to use only one PET tracer to make all clinical decisions because each tracer has both advantages and disadvantages. This study focuses on the different kinds of PET tracers and summarizes their recent applications in patients with gliomas. Combinational uses of PET tracers are expected to contribute to differential diagnosis, prognosis, treatment targeting, and monitoring therapy. PMID:27250577

  14. Modularized compact positron emission tomography detector for rapid system development.

    PubMed

    Xi, Daoming; Liu, Xiang; Zeng, Chen; Liu, Wei; Li, Yanzhao; Hua, Yuexuan; Mei, Xiongze; Kim, Heejong; Xiao, Peng; Kao, Chien-Min; Xie, Qingguo

    2017-01-01

    We report the development of a modularized compact positron emission tomography (PET) detector that outputs serial streams of digital samples of PET event pulses via an Ethernet interface using the UDP/IP protocol to enable rapid configuration of a PET system by connecting multiple such detectors via a network switch to a computer. Presently, the detector is [Formula: see text] in extent (excluding I/O connectors) and contains an [Formula: see text] array of [Formula: see text] one-to-one coupled lutetium-yttrium oxyorthosilicate/silicon photomultiplier pixels. It employs cross-wire and stripline readouts to merge the outputs of the 216 detector pixels to 24 channels. Signals at these channels are sampled using a built-in 24-ch, 4-level field programmable gate arrays-only multivoltage threshold digitizer. In the computer, software programs are implemented to analyze the digital samples to extract event information and to perform energy qualification and coincidence filtering. We have developed two such detectors. We show that all their pixels can be accurately discriminated and measure a crystal-level energy resolution of 14.4% to 19.4% and a detector-level coincidence time resolution of 1.67 ns FWHM. Preliminary imaging results suggests that a PET system based on the detectors can achieve an image resolution of [Formula: see text].

  15. FPGA-Based Pulse Parameter Discovery for Positron Emission Tomography.

    PubMed

    Haselman, Michael; Hauck, Scott; Lewellen, Thomas K; Miyaoka, Robert S

    2009-10-24

    Modern Field Programmable Gate Arrays (FPGAs) are capable of performing complex digital signal processing algorithms with clock rates well above 100MHz. This, combined with FPGA's low expense and ease of use make them an ideal technology for a data acquisition system for a positron emission tomography (PET) scanner. The University of Washington is producing a series of high-resolution, small-animal PET scanners that utilize FPGAs as the core of the front-end electronics. For these next generation scanners, functions that are typically performed in dedicated circuits, or offline, are being migrated to the FPGA. This will not only simplify the electronics, but the features of modern FPGAs can be utilizes to add significant signal processing power to produce higher resolution images. In this paper we report how we utilize the reconfigurable property of an FPGA to self-calibrate itself to determine pulse parameters necessary for some of the pulse processing steps. Specifically, we show how the FPGA can generate a reference pulse based on actual pulse data instead of a model. We also report how other properties of the photodetector pulse (baseline, pulse length, average pulse energy and event triggers) can be determined automatically by the FPGA.

  16. Quantitative Cardiac Positron Emission Tomography: The Time Is Coming!

    PubMed Central

    Sciagrà, Roberto

    2012-01-01

    In the last 20 years, the use of positron emission tomography (PET) has grown dramatically because of its oncological applications, and PET facilities are now easily accessible. At the same time, various groups have explored the specific advantages of PET in heart disease and demonstrated the major diagnostic and prognostic role of quantitation in cardiac PET. Nowadays, different approaches for the measurement of myocardial blood flow (MBF) have been developed and implemented in user-friendly programs. There is large evidence that MBF at rest and under stress together with the calculation of coronary flow reserve are able to improve the detection and prognostication of coronary artery disease. Moreover, quantitative PET makes possible to assess the presence of microvascular dysfunction, which is involved in various cardiac diseases, including the early stages of coronary atherosclerosis, hypertrophic and dilated cardiomyopathy, and hypertensive heart disease. Therefore, it is probably time to consider the routine use of quantitative cardiac PET and to work for defining its place in the clinical scenario of modern cardiology. PMID:24278760

  17. Markerless motion tracking of awake animals in positron emission tomography.

    PubMed

    Kyme, Andre; Se, Stephen; Meikle, Steven; Angelis, Georgios; Ryder, Will; Popovic, Kata; Yatigammana, Dylan; Fulton, Roger

    2014-11-01

    Noninvasive functional imaging of awake, unrestrained small animals using motion-compensation removes the need for anesthetics and enables an animal's behavioral response to stimuli or administered drugs to be studied concurrently with imaging. While the feasibility of motion-compensated radiotracer imaging of awake rodents using marker-based optical motion tracking has been shown, markerless motion tracking would avoid the risk of marker detachment, streamline the experimental workflow, and potentially provide more accurate pose estimates over a greater range of motion. We have developed a stereoscopic tracking system which relies on native features on the head to estimate motion. Features are detected and matched across multiple camera views to accumulate a database of head landmarks and pose is estimated based on 3D-2D registration of the landmarks to features in each image. Pose estimates of a taxidermal rat head phantom undergoing realistic rat head motion via robot control had a root mean square error of 0.15 and 1.8 mm using markerless and marker-based motion tracking, respectively. Markerless motion tracking also led to an appreciable reduction in motion artifacts in motion-compensated positron emission tomography imaging of a live, unanesthetized rat. The results suggest that further improvements in live subjects are likely if nonrigid features are discriminated robustly and excluded from the pose estimation process.

  18. Variation in Positron Emission Tomography Use After Colon Cancer Resection

    PubMed Central

    Bailey, Christina E.; Hu, Chung-Yuan; You, Y. Nancy; Kaur, Harmeet; Ernst, Randy D.; Chang, George J.

    2015-01-01

    Purpose: Colon cancer surveillance guidelines do not routinely include positron emission tomography (PET) imaging; however, its use after surgical resection has been increasing. We evaluated the secular patterns of PET use after surgical resection of colon cancer among elderly patients and identified factors associated with its increasing use. Patients and Methods: We used the SEER-linked Medicare database (July 2001 through December 2009) to establish a retrospective cohort of patients age ≥ 66 years who had undergone surgical resection for colon cancer. Postoperative PET use was assessed with the test for trends. Patient, tumor, and treatment characteristics were analyzed using univariable and multivariable logistic regression analyses. Results: Of the 39,221 patients with colon cancer, 6,326 (16.1%) had undergone a PET scan within 2 years after surgery. The use rate steadily increased over time. The majority of PET scans had been performed within 2 months after surgery. Among patients who had undergone a PET scan, 3,644 (57.6%) had also undergone preoperative imaging, and 1,977 (54.3%) of these patients had undergone reimaging with PET within 2 months after surgery. Marriage, year of diagnosis, tumor stage, preoperative imaging, postoperative visit to a medical oncologist, and adjuvant chemotherapy were significantly associated with increased PET use. Conclusion: PET use after colon cancer resection is steadily increasing, and further study is needed to understand the clinical value and effectiveness of PET scans and the reasons for this departure from guideline-concordant care. PMID:25852143

  19. Positron emission tomography in patients with clinically diagnosed Alzheimer's disease.

    PubMed Central

    McGeer, P L; Kamo, H; Harrop, R; Li, D K; Tuokko, H; McGeer, E G; Adam, M J; Ammann, W; Beattie, B L; Calne, D B

    1986-01-01

    Fourteen patients who had clinically diagnosed Alzheimer's disease with mild to severe dementia (mean age 69.1 years) were evaluated by calculation of local cerebral metabolic rate for glucose (LCMR-gl) based on uptake of 18F-2-fluoro-2-deoxyglucose (FDG) detected with positron emission tomography (PET). PET scanning showed that the patients had significantly lower LCMR-gl values than 11 age-matched neurologically normal volunteers (mean age 66.3 years). The differences were most marked in the temporal cortex, followed by the frontal, parietal and occipital cortex. In each case the LCMR-gl value was below the lowest control value in at least one cortical area and usually in several; the reduction in LCMR-gl and the number of regions involved in the patients increased with the severity of the dementia. Deficits noted in neuropsychologic testing generally correlated with those predicted from loss of regional cortical metabolism. The patients with Alzheimer's disease were also examined with magnetic resonance imaging, computed tomography or both; the degree of atrophy found showed only a poor correlation with the neuropsychologic deficit. Significant atrophy was also noted in some of the controls. A detailed analysis of LCMR-gl values in selected cerebral regions of various sizes refuted the hypothesis that the reduction in cortical glucose metabolism in Alzheimer's disease is due to the filling by metabolically inert cerebrospinal fluid of space created by tissue atrophy. Images Fig. 2 Fig. 3 Fig. 4 Fig. 7 Fig. 8 Fig. 9 PMID:3512063

  20. Therapy response evaluation with positron emission tomography-computed tomography.

    PubMed

    Segall, George M

    2010-12-01

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

  1. Characterization of nontransmural myocardial infarction by positron-emission tomography

    SciTech Connect

    Geltman, E.M.; Biello, D.; Welch, M.J.; Ter-Pogossian, M.M.; Roberts, R.; Sobel, B.E.

    1982-04-01

    The present study was performed to determine whether positron emission tomography (PET) performed after i.v. 11C-palmitate permits detection and characterization of nontransmural myocardial infarction. PET was performed after the i.v. injection of 11C-palmitate in 10 normal subjects, 24 patients with initial nontransmural myocardial infarction (defined electrocardiographically), and 22 patients with transmural infarction. Depressed accumulation of 11C-palmitate was detected with sagittal, coronal and transverse reconstructions, and quantified based on 14 contiguous transaxial reconstructions. Defects with homogeneously intense depression of accumulation of tracer were detected in all 22 patients with transmural infarction (100%). Abnormalities of the distribution of 11C-palmitate in the myocardium were detected in 23 patients with nontransmural infarction (96%). Thallium scintigrams were abnormal in only 11 of 18 patients with nontransmural infarction (61%). Tomographically estimated infarct size was greater among patients with transmural infarction (50.4 +/- 7.8 PET-g-Eq/m2 (+/- SEM SEM)) compared with those with nontransmural infarction (19 +/- 4 PET-g-Eq, p less than 0.01). Residual accumulation of 11C-palmitate within regions of infarction was more intensely depressed among patients with transmural compared to nontransmural infarction (33 +/- 1 vs 39 +/- 1% maximal myocardial radioactivity, p less than 0.01). Thus, PET and metabolic imaging with 11C-palmitate is a sensitive means of detecting, quantifying and characterizing nontransmural and transmural myocardial infarction.

  2. Application of silicon photomultipliers to positron emission tomography.

    PubMed

    Roncali, Emilie; Cherry, Simon R

    2011-04-01

    Historically, positron emission tomography (PET) systems have been based on scintillation crystals coupled to photomultipliers tubes (PMTs). However, the limited quantum efficiency, bulkiness, and relatively high cost per unit surface area of PMTs, along with the growth of new applications for PET, offers opportunities for other photodetectors. Among these, small-animal scanners, hybrid PET/MRI systems, and incorporation of time-of-flight information are of particular interest and require low-cost, compact, fast, and magnetic field compatible photodetectors. With high quantum efficiency and compact structure, avalanche photodiodes (APDs) overcome several of the drawbacks of PMTs, but this is offset by degraded signal-to-noise and timing properties. Silicon photomultipliers (SiPMs) offer an alternative solution, combining many of the advantages of PMTs and APDs. They have high gain, excellent timing properties and are insensitive to magnetic fields. At the present time, SiPM technology is rapidly developing and therefore an investigation into optimal design and operating conditions is underway together with detailed characterization of SiPM-based PET detectors. Published data are extremely promising and show good energy and timing resolution, as well as the ability to decode small scintillator arrays. SiPMs clearly have the potential to be the photodetector of choice for some, or even perhaps most, PET systems.

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

    PubMed Central

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

    2012-01-01

    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 radiochemistry can lead to the use of smaller quantities of precursors, accelerated reaction rates and easier purification processes with greater yield and higher specific activity of desired probes. Several ‘proof-of-principle’ examples, along with basics of device architecture and operation, and potential limitations of each design are discussed here. Along with the concept of radioisotope distribution from centralized cyclotron facilities to individual imaging centers and laboratories (“decentralized model”), an easy-to-use, standalone, flexible, fully-automated radiochemical microfluidic platform can open up to simpler and more cost-effective procedures for molecular imaging using PET. PMID:20643021

  4. Automated identification of the lung contours in positron emission tomography

    NASA Astrophysics Data System (ADS)

    Nery, F.; Silvestre Silva, J.; Ferreira, N. C.; Caramelo, F. J.; Faustino, R.

    2013-03-01

    Positron Emission Tomography (PET) is a nuclear medicine imaging technique that permits to analyze, in three dimensions, the physiological processes in vivo. One of the areas where PET has demonstrated its advantages is in the staging of lung cancer, where it offers better sensitivity and specificity than other techniques such as CT. On the other hand, accurate segmentation, an important procedure for Computer Aided Diagnostics (CAD) and automated image analysis, is a challenging task given the low spatial resolution and the high noise that are intrinsic characteristics of PET images. This work presents an algorithm for the segmentation of lungs in PET images, to be used in CAD and group analysis in a large patient database. The lung boundaries are automatically extracted from a PET volume through the application of a marker-driven watershed segmentation procedure which is robust to the noise. In order to test the effectiveness of the proposed method, we compared the segmentation results in several slices using our approach with the results obtained from manual delineation. The manual delineation was performed by nuclear medicine physicians that used a software routine that we developed specifically for this task. To quantify the similarity between the contours obtained from the two methods, we used figures of merit based on region and also on contour definitions. Results show that the performance of the algorithm was similar to the performance of human physicians. Additionally, we found that the algorithm-physician agreement is similar (statistically significant) to the inter-physician agreement.

  5. Positron Emission Tomography Detector Development for Plant Biology

    SciTech Connect

    Weisenberger, A G; McKisson, J; Stolin, A; Zorn, C; Howell, C R; Crowell, A S; Reid, C D; Majewski, S; Smith, M F

    2010-01-01

    There are opportunities for the development of new tools to advance plant biology research through the use of radionuclides. Thomas Jefferson National Accelerator Facility, Duke University, West Virginia University and the University of Maryland are collaborating on the development of radionuclide imaging technologies to facilitate plant biology research. Biological research into optimizing plant productivity under various environmental constraints, biofuel and carbon sequestration research are areas that could potentially benefit from new imaging technologies. Using 11CO2 tracers, the investigators at Triangle University Nuclear Laboratory / Duke University Phytotron are currently researching the dynamical responses of plants to environmental changes forecasted from increasing greenhouse trace gases involved in global change. The biological research primary focus is to investigate the impact of elevated atmospheric CO2 and nutrients limitation on carbon and nitrogen dynamics in plants. We report here on preliminary results of 11CO2 plant imaging experiments involving barley plants using Jefferson Lab dual planar positron emission tomography detectors to image 11CO2 in live barley plants. New detector designs will be developed based on the preliminary studies reported here and further planned.

  6. Florbetapir positron emission tomography and cerebrospinal fluid biomarkers

    PubMed Central

    Hake, Ann; Trzepacz, Paula T.; Wang, Shufang; Yu, Peng; Case, Michael; Hochstetler, Helen; Witte, Michael M.; Degenhardt, Elisabeth K.; Dean, Robert A.

    2015-01-01

    Background We evaluated the relationship between florbetapir-F18 positron emission tomography (FBP PET) and cerebrospinal fluid (CSF) biomarkers. Methods Alzheimer’s Disease Neuroimaging Initiative (ADNI)-GO/2 healthy control (HC), mild cognitive impairment (MCI), and Alzheimer’s disease (AD) dementia subjects with clinical measures and CSF collected ±90 days of FBP PET data were analyzed using correlation and logistic regression. Results In HC and MCI subjects, FBP PET anterior and posterior cingulate and composite standard uptake value ratios correlated with CSF amyloid beta (Aβ1-42) and tau/Aβ1-42 ratios. Using logistic regression, Aβ1-42, total tau (t-tau), phosphorylated tau181P (p-tau), and FBP PET composite each differentiated HC versus AD. Aβ1-42 and t-tau distinguished MCI versus AD, without additional contribution by FBP PET. Total tau and p-tau added discriminative power to FBP PET when classifying HC versus AD. Conclusion Based on cross-sectional diagnostic groups, both amyloid and tau measures distinguish healthy from demented subjects. Longitudinal analyses are needed. PMID:25916563

  7. Simultaneous laser speckle imaging and positron emission tomography

    NASA Astrophysics Data System (ADS)

    Gramer, M.; Feuerstein, D.; Backes, H.; Takagaki, M.; Kumagai, T.; Graf, R.

    2013-06-01

    Complex biological systems often require measurements of multiple parameters with high temporal and spatial resolution. Multimodal approaches and the combination of methods are therefore a powerful tool to address such scientific questions. Laser speckle imaging (LSI) is an optical method that monitors dynamic changes in cortical blood flow (CBF) with high temporal resolution. Positron emission tomography (PET) allows for quantitative imaging of physiological processes and is a gold standard method to determine absolute cerebral blood flow. We developed a setup that allows simultaneous measurement with both modalities. Here, we simultaneously measured CBF with PET and LSI in rats and analyzed how the correlation of PET and LSI is modified when (1) different methods are used for the calculation of speckle inverse correlation time (ICT), (2) speckle data is acquired through thinned or craniectomized skull, (3) influence of surface vessels is removed from the speckle data. For the latter, a method for automated vessel segmentation from LSI data was developed. We obtained the best correlation (R² = 0.890, p<0.001) when correcting for surface vessel structures taking into account the contribution of static scatterers while keeping the coherence factor constant. However, using the originally published relation, which allows a 900 times faster computation of blood flow maps, still provided a good correlation (R2 = 0.879, p<0.001). Given the good correlation between LSI and PET we used our data to calibrate the speckle ICT. Thus, LSI provides CBF in absolute units at high temporal resolution.

  8. Fuzzy-rule-based image reconstruction for positron emission tomography

    NASA Astrophysics Data System (ADS)

    Mondal, Partha P.; Rajan, K.

    2005-09-01

    Positron emission tomography (PET) and single-photon emission computed tomography have revolutionized the field of medicine and biology. Penalized iterative algorithms based on maximum a posteriori (MAP) estimation eliminate noisy artifacts by utilizing available prior information in the reconstruction process but often result in a blurring effect. MAP-based algorithms fail to determine the density class in the reconstructed image and hence penalize the pixels irrespective of the density class. Reconstruction with better edge information is often difficult because prior knowledge is not taken into account. The recently introduced median-root-prior (MRP)-based algorithm preserves the edges, but a steplike streaking effect is observed in the reconstructed image, which is undesirable. A fuzzy approach is proposed for modeling the nature of interpixel interaction in order to build an artifact-free edge-preserving reconstruction. The proposed algorithm consists of two elementary steps: (1) edge detection, in which fuzzy-rule-based derivatives are used for the detection of edges in the nearest neighborhood window (which is equivalent to recognizing nearby density classes), and (2) fuzzy smoothing, in which penalization is performed only for those pixels for which no edge is detected in the nearest neighborhood. Both of these operations are carried out iteratively until the image converges. Analysis shows that the proposed fuzzy-rule-based reconstruction algorithm is capable of producing qualitatively better reconstructed images than those reconstructed by MAP and MRP algorithms. The reconstructed images are sharper, with small features being better resolved owing to the nature of the fuzzy potential function.

  9. Positron emission tomography as a diagnostic tool in oncology.

    PubMed

    Schiepers, C; Hoh, C K

    1998-01-01

    Early diagnosis in oncology is important for treatment by surgical intervention, which generally has the highest curative potential. For higher stages of disease involvement, initiation of rapid treatment is indicated to provide the patient with the optimal therapy regimen. Although this may not improve the prognosis, it will maintain the quality of life. Anatomic imaging modalities, such as CT, MR imaging, and US, are clinically important high-resolution imaging techniques that are well suited to reveal structural abnormalities. However, the differentiation of lesions as being benign or malignant is still problematic. Metabolic imaging modalities in nuclear medicine (NM), i.e., single photon emission computed tomography (SPECT) and positron emission tomography (PET), can reveal biochemical parameters of the lesions such as glucose, oxygen, or amino acid metabolism, or measure the receptor density status. These parameters may allow a completely new clinical perspective in the management and understanding of diseases such as cancer. Although PET has been around since the early 1960s, it has only recently emerged as a powerful diagnostic tool in oncology. Society has great difficulty accepting this clinical imaging modality because of its high cost and complexity. Current applications of PET in oncology have been in characterizing lesions, differentiating recurrent disease from treatment effects, staging tumors, evaluating the extent of disease, and therapy monitoring. Here, the role of PET in diagnosis, staging, and restaging of cancer is reviewed and compared with the other tumor imaging modalities. We cover articles published in the past 3 years. We utilize the typical radiology format, in which the contribution in each body area is reviewed (topographic orientation), instead of the more organ-based approach used in internal medicine.

  10. Positron bunching and electrostatic transport system for the production and emission of dense positronium clouds into vacuum

    NASA Astrophysics Data System (ADS)

    Aghion, S.; Amsler, C.; Ariga, A.; Ariga, T.; Belov, A. S.; Bonomi, G.; Bräunig, P.; Bremer, J.; Brusa, R. S.; Cabaret, L.; Caccia, M.; Caravita, R.; Castelli, F.; Cerchiari, G.; Chlouba, K.; Cialdi, S.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Dudarev, A.; Ereditato, A.; Evans, C.; Fesel, J.; Fontana, A.; Forslund, O. K.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Gninenko, S.; Guatieri, F.; Haider, S.; Holmestad, H.; Huse, T.; Jernelv, I. L.; Jordan, E.; Kaltenbacher, T.; Kellerbauer, A.; Kimura, M.; Koetting, T.; Krasnicky, D.; Lagomarsino, V.; Lebrun, P.; Lansonneur, P.; Lehner, S.; Liberadzka, J.; Malbrunot, C.; Mariazzi, S.; Marx, L.; Matveev, V.; Mazzotta, Z.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pacifico, N.; Pagano, D.; Penasa, L.; Petracek, V.; Pistillo, C.; Prelz, F.; Prevedelli, M.; Ravelli, L.; Rienäcker, B.; Røhne, O. M.; Rosenberger, S.; Rotondi, A.; Sacerdoti, M.; Sandaker, H.; Santoro, R.; Scampoli, P.; Sorrentino, F.; Spacek, M.; Storey, J.; Strojek, I. M.; Testera, G.; Tietje, I.; Vamosi, S.; Widmann, E.; Yzombard, P.; Zavatarelli, S.; Zmeskal, J.

    2015-11-01

    We describe a system designed to re-bunch positron pulses delivered by an accumulator supplied by a positron source and a Surko-trap. Positron pulses from the accumulator are magnetically guided in a 0.085 T field and are injected into a region free of magnetic fields through a μ -metal field terminator. Here positrons are temporally compressed, electrostatically guided and accelerated towards a porous silicon target for the production and emission of positronium into vacuum. Positrons are focused in a spot of less than 4 mm FWTM in bunches of ∼8 ns FWHM. Emission of positronium into the vacuum is shown by single shot positron annihilation lifetime spectroscopy.

  11. Positron Emission Tomography for the Assessment of Myocardial Viability

    PubMed Central

    2005-01-01

    Executive Summary Objective The objective was to update the 2001 systematic review conducted by the Institute For Clinical Evaluative Sciences (ICES) on the use of positron emission tomography (PET) in assessing myocardial viability. The update consisted of a review and analysis of the research evidence published since the 2001 ICES review to determine the effectiveness and cost-effectiveness of PET in detecting left ventricular (LV) viability and predicting patient outcomes after revascularization in comparison with other noninvasive techniques. Background Left Ventricular Viability Heart failure is a complex syndrome that impairs the contractile ability of the heart to maintain adequate blood circulation, resulting in poor functional capacity and increased risk of morbidity and mortality. It is the leading cause of hospitalization in elderly Canadians. In more than two-thirds of cases, heart failure is secondary to coronary heart disease. It has been shown that dysfunctional myocardium resulting from coronary heart disease (CAD) may recover contractile function (i.e. considered viable). Dysfunctional but viable myocardium may have been stunned by a brief episode of ischemia, followed by restoration of perfusion, and may regain function spontaneously. It is believed that repetitive stunning results in hibernating myocardium that will only regain contractile function upon revascularization. For people with CAD and severe LV dysfunction (left ventricular ejection fraction [LVEF] <35%) refractory to medical therapy, coronary artery bypass and heart transplantation are the only treatment options. The opportunity for a heart transplant is limited by scarcityof donor hearts. Coronary artery bypass in these patients is associated with high perioperative complications; however, there is evidence that revascularization in the presence of dysfunctional but viable myocardium is associated with survival benefits and lower rates of cardiac events. The assessment of left

  12. Positron emission tomography: a financial and operational analysis.

    PubMed

    Conti, P S; Keppler, J S; Halls, J M

    1994-06-01

    Positron emission tomography (PET) is an emerging clinical imaging technique that is facing the challenges of expansion in a period of imminent health care contraction and reform. Although PET began showing utility in clinical medicine in the mid-1980s [1], its proliferation into mainstream medical practice has not matched that of other new imaging technologies such as MR imaging. Many factors have contributed to this, including the changing health care economy, the high cost of PET, the length of time it takes to develop a PET facility, and its inherent complexity. In part because of the proliferation of the use of other technologies and the general explosion of costs, insurance carriers are now holding diagnostic techniques, including PET, to stricter standards of efficacy. New techniques must show improvement in long-term outcome of patients, a difficult task for diagnostic tools. In addition to these issues, PET is an expensive technology that requires highly trained multidisciplinary personnel. Questions have also been raised about the most appropriate mechanism for regulation of PET isotope preparation, leading to speculation about future regulatory requirements. The current pioneers of PET must meet these challenges in order for it to become a routine imaging technique. Because of its clinical value, PET will probably survive despite the challenges. For many reasons, though, not every hospital should necessarily develop PET services. Conversely, many hospitals without this technology should consider acquiring PET. The purpose of this article is to identify the financial, operational, and clinical challenges facing PET centers today, describe potential organizational configurations that may enable PET to survive in an antitechnology environment, and delineate which institutions should consider this new technology.

  13. Nonhuman primate positron emission tomography neuroimaging in drug abuse research.

    PubMed

    Howell, Leonard Lee; Murnane, Kevin Sean

    2011-05-01

    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 characterized in vivo drug interactions with specific protein targets in the brain, including neurotransmitter receptors and transporters. In vivo determinations of cerebral blood flow and metabolism have localized brain circuits implicated in the effects of abused drugs and drug-associated stimuli. Moreover, determinations of the predisposing factors to chronic drug use and long-term neurobiological consequences of chronic drug use, such as potential neurotoxicity, have led to novel insights regarding the pathology and treatment of drug addiction. However, similar approaches clearly need to be extended to drug classes other than stimulants. Although dopaminergic systems have been extensively studied, other neurotransmitter systems known to play a critical role in the pharmacological effects of abused drugs have been largely ignored in nonhuman primate PET neuroimaging. Finally, the study of brain activation with PET neuroimaging has been replaced in humans mostly by functional magnetic resonance imaging (fMRI). There has been some success in implementing pharmacological fMRI in awake nonhuman primates. Nevertheless, the unique versatility of PET imaging will continue to complement the systems-level strengths of fMRI, especially in the context of nonhuman primate drug abuse research.

  14. Super-resolution in respiratory synchronized positron emission tomography.

    PubMed

    Wallach, Daphné; Lamare, Frédéric; Kontaxakis, Giorgos; Visvikis, Dimitris

    2012-02-01

    Respiratory motion is a major source of reduced quality in positron emission tomography (PET). In order to minimize its effects, the use of respiratory synchronized acquisitions, leading to gated frames, has been suggested. Such frames, however, are of low signal-to-noise ratio (SNR) as they contain reduced statistics. Super-resolution (SR) techniques make use of the motion in a sequence of images in order to improve their quality. They aim at enhancing a low-resolution image belonging to a sequence of images representing different views of the same scene. In this work, a maximum a posteriori (MAP) super-resolution algorithm has been implemented and applied to respiratory gated PET images for motion compensation. An edge preserving Huber regularization term was used to ensure convergence. Motion fields were recovered using a B-spline based elastic registration algorithm. The performance of the SR algorithm was evaluated through the use of both simulated and clinical datasets by assessing image SNR, as well as the contrast, position and extent of the different lesions. Results were compared to summing the registered synchronized frames on both simulated and clinical datasets. The super-resolution image had higher SNR (by a factor of over 4 on average) and lesion contrast (by a factor of 2) than the single respiratory synchronized frame using the same reconstruction matrix size. In comparison to the motion corrected or the motion free images a similar SNR was obtained, while improvements of up to 20% in the recovered lesion size and contrast were measured. Finally, the recovered lesion locations on the SR images were systematically closer to the true simulated lesion positions. These observations concerning the SNR, lesion contrast and size were confirmed on two clinical datasets included in the study. In conclusion, the use of SR techniques applied to respiratory motion synchronized images lead to motion compensation combined with improved image SNR and contrast

  15. Noninvasive imaging of islet grafts using positron-emission tomography

    NASA Astrophysics Data System (ADS)

    Lu, Yuxin; Dang, Hoa; Middleton, Blake; Zhang, Zesong; Washburn, Lorraine; Stout, David B.; Campbell-Thompson, Martha; Atkinson, Mark A.; Phelps, Michael; Gambhir, Sanjiv Sam; Tian, Jide; Kaufman, Daniel L.

    2006-07-01

    Islet transplantation offers a potential therapy to restore glucose homeostasis in type 1 diabetes patients. However, islet transplantation is not routinely successful because most islet recipients gradually lose graft function. Furthermore, serological markers of islet function are insensitive to islet loss until the latter stages of islet graft rejection. A noninvasive method of monitoring islet grafts would aid in the assessment of islet graft survival and the evaluation of interventions designed to prolong graft survival. Here, we show that recombinant adenovirus can engineer isolated islets to express a positron-emission tomography (PET) reporter gene and that these islets can be repeatedly imaged by using microPET after transplantation into mice. The magnitude of signal from engineered islets implanted into the axillary cavity was directly related to the implanted islet mass. PET signals attenuated over the following weeks because of the transient nature of adenovirus-mediated gene expression. Because the liver is the preferred site for islet implantation in humans, we also tested whether islets could be imaged after transfusion into the mouse liver. Control studies revealed that both intrahepatic islet transplantation and hyperglycemia altered the biodistribution kinetics of the PET probe systemically. Although transplanted islets were dispersed throughout the liver, clear signals from the liver region of mice receiving PET reporter-expressing islets were detectable for several weeks. Viral transduction, PET reporter expression, and repeated microPET imaging had no apparent deleterious effects on islet function after implantation. These studies lay a foundation for noninvasive quantitative assessments of islet graft survival using PET. diabetes | transplantation

  16. [Understanding positon emission tomography (PET) with [18F]-FDG in clinical oncology. Informations dedicated to patients and relatives].

    PubMed

    Bourguet, Patrick; Brusco, Sylvie; Corone, Corinne; Devillers, Anne; Foehrenbach, Hervé; Lumbroso, Jean-Daniel; Maszelin, Philippe; Montravers, Françoise; Moretti, Jean-Luc; Rain, Jean-Didier; Talbot, Jean-Noël; Carretier, Julien; Leichtnam-Dugarin, Line; Delavigne, Valérie; Philip, Thierry; Fervers, Béatrice

    2005-07-01

    In response to the evolution of the information-seeking behaviour of patients and concerns from health professionals regarding cancer patient information, the French National Federation of Comprehensive Cancer Centres (FNCLCC) introduced, in 1998, an information and education program dedicated to patients and relatives, the SOR SAVOIR PATIENT program (SSP). The methodology of this program adheres to established quality criteria regarding the elaboration of patient information. Cancer patient information, developed in this program, is based on clinical practice guidelines produced by the FNCLCC and the twenty French regional cancer centres, the National League against Cancer, the French Hospital Federation, the National Oncology Federation of Regional and University Hospitals, the French Oncology Federation of General Hospitals, many learned societies, as well as an active participation of patients, former patients and caregivers. The guidelines, "Standards, Options: Recommendations" (SOR) are used as primary information sources. The handbook SOR SAVOIR PATIENT Understanding positron emission tomography (PET) with [18F]-FDG in clinical oncology, integrally published in this issue of the Bulletin du Cancer, is an adapted version of the clinical practice guidelines (CPG) Standards, Options and Recommendations for positron emission tomography (PET) with [18F]-FDG in clinical oncology. The main objectives of this article are to allow persons affected by cancer and their close relatives to better understand this medical imaging technique and its implementation. This document also offers health professionals a synthetic evidence-based patient information source that should help them communicate that information during the physician-patient encounter. Positron emission tomography (PET) is a scintigraphy technique using a radiotracer, [18F]-fluorodeoxyglucose (abbreviated [18F]-FDG), administered intravenously into the patient's arm. This tracer, similar to glucose (sugar

  17. Positron Emission Tomography Imaging Using Radiolabeled Inorganic Nanomaterials

    PubMed Central

    Sun, Xiaolian; Cai, Weibo; Chen, Xiaoyuan

    2015-01-01

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

  18. Evaluating Positron Emission Tomography Use in Differentiated Thyroid Cancer

    PubMed Central

    Esfandiari, Nazanene H.; Papaleontiou, Maria; Worden, Francis P.; Haymart, Megan R.

    2015-01-01

    Background: Using the Surveillance, Epidemiology, and End Results—Medicare database, a substantial increase was found in the use of positron emission tomography (PET) scans after 2004 in differentiated thyroid cancer (DTC) patients. The reason for the increased utilization of the PET scan was not clear based on available the data. Therefore, the indications for and outcomes of PET scans performed at an academic institution were evaluated. Methods: A retrospective cohort study was performed of DTC patients who underwent surgery at the University of Michigan Health System from 2006 to 2011. After identifying patients who underwent a PET scan, indications, rate of positive PET scans, and impact on management were evaluated. For positive scans, the location of disease was characterized, and presence of disease on other imaging was determined. Results: Of the 585 patients in the cohort, 111 (19%) patients had 200 PET scans performed for evaluation of DTC. Indications for PET scan included: elevated thyroglobulin and negative radioiodine scan in 52 scans (26.0%), thyroglobulin antibodies in 13 scans (6.5%), rising thyroglobulin in 18 scans (9.0%), evaluation of abnormality on other imaging in 22 scans (11.0%), evaluation of extent of disease in 33 scans (16.5%), follow-up of previous scan in 57 scans (28.5%), other indications in two scans (1.0%), and unclear indications in three scans (1.5%). The PET scan was positive in 124 studies (62.0%); positivity was identified in the thyroid bed on 25 scans, cervical or mediastinal lymph nodes on 105 scans, lung on 28 scans, bone on four scans, and other areas on 14 scans. Therapy following PET scan was surgery in 66 cases (33.0%), chemotherapy or radiation in 23 cases (11.5%), observation in 110 cases (55.0%), and palliative care in one case (0.5%). Disease was identifiable on other imaging in 66% of cases. PET scan results changed management in 59 cases (29.5%). Conclusions: In this academic medical center, the PET scan was

  19. Positron emission tomography imaging using radiolabeled inorganic nanomaterials.

    PubMed

    Sun, Xiaolian; Cai, Weibo; Chen, Xiaoyuan

    2015-02-17

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

  20. Positron emission tomography and single-photon emission computed tomography in substance abuse research.

    PubMed

    Volkow, Nora D; Fowler, Joanna S; Wang, Gene-Jack

    2003-04-01

    Many advances in the conceptualization of addiction as a disease of the brain have come from the application of imaging technologies directly in the human drug abuser. New knowledge has been driven by advances in radiotracer design and chemistry and positron emission tomography (PET) and single-photon emission computed tomography (SPECT) instrumentation and the integration of these scientific tools with the tools of biochemistry, pharmacology, and medicine. This topic cuts across the medical specialties of neurology, psychiatry, oncology, and cardiology because of the high medical, social, and economic toll that drugs of abuse, including the legal drugs, cigarettes and alcohol, take on society. This article highlights recent advances in the use of PET and SPECT imaging to measure the pharmacokinetic and pharmacodynamic effects of drugs of abuse on the human brain.

  1. Positron emission tomography within a magnetic field using photomultiplier tubes and lightguides.

    PubMed

    Christensen, N L; Hammer, B E; Heil, B G; Fetterly, K

    1995-04-01

    The spatial resolution of positron emission tomography (PET) improves when positron annihilation takes place in a strong magnetic field. In a magnetic field, the Lorentz force restricts positron range perpendicular to the field. Since positron annihilation occurs closer to its point of origin, the positron annihilation point spread function decreases. This was verified experimentally by measuring the spread function of positron annihilation from a 500 mm 68Ge bead imbedded in tissue-equivalent wax. At 5 T the spread function full width at half maximum (FWHM) and the full width at tenth maximum (FWTM) decrease by a factor of 1.42 and 2.09, respectively. Two NaI(Tl) scintillation crystals that interface to a pair of photomultiplier tubes (PMTS) through long lightguides detect positron annihilation at zero field and 5.0 T. Photomultiplier tubes, inoperable in strong magnetic fields, are functional if lightguides bring the photons produced by scintillators within the field to a minimal magnetic field. These tests also demonstrate techniques necessary for combining magnetic resonance imaging (MRI) and PET into one scanner.

  2. Novel pulsed particle accelerator for energy dependent positron re-emission experiments.

    PubMed

    Grill, Niklas; Piochacz, Christian; Zimnik, Samantha; Hugenschmidt, Christoph

    2016-05-01

    We report on a novel device for particle acceleration based on elevation of the potential energy of beam pulses. This so-called energy elevator is particularly beneficial if both the particle source and the sample have to be near ground potential due to experimental constraints. We applied this new technique to enable depth dependent measurements of re-emitted positrons using the surface spectrometer at the NEPOMUC positron beam facility. First, a two-stage bunching system is used to generate positron pulses with a repetition rate of 5 MHz and a duration of 1.663(5) ns before their energy is raised to several keV. The whole system was shown to work with an exceptional efficiency of 88%. We demonstrated the usability of our setup by investigating the positron re-emission spectra of Ni and Pd as function of positron implantation energy. For Ni the positron work function could be determined to be ΦNi (+)=-1.4(2)eV. In addition, as predicted by theory, our experimental findings imply a positive positron work function for Pd.

  3. Cerebrospinal fluid analysis detects cerebral amyloid-β accumulation earlier than positron emission tomography

    PubMed Central

    Mattsson, Niklas

    2016-01-01

    See Rabinovici (doi:10.1093/brain/aww025) for a scientific commentary on this article. Cerebral accumulation of amyloid-β is thought to be the starting mechanism in Alzheimer’s disease. Amyloid-β can be detected by analysis of cerebrospinal fluid amyloid-β42 or amyloid positron emission tomography, but it is unknown if any of the methods can identify an abnormal amyloid accumulation prior to the other. Our aim was to determine whether cerebrospinal fluid amyloid-β42 change before amyloid PET during preclinical stages of Alzheimer’s disease. We included 437 non-demented subjects from the prospective, longitudinal Alzheimer’s Disease Neuroimaging Initiative (ADNI) study. All underwent 18F-florbetapir positron emission tomography and cerebrospinal fluid amyloid-β42 analysis at baseline and at least one additional positron emission tomography after a mean follow-up of 2.1 years (range 1.1–4.4 years). Group classifications were based on normal and abnormal cerebrospinal fluid and positron emission tomography results at baseline. We found that cases with isolated abnormal cerebrospinal fluid amyloid-β and normal positron emission tomography at baseline accumulated amyloid with a mean rate of 1.2%/year, which was similar to the rate in cases with both abnormal cerebrospinal fluid and positron emission tomography (1.2%/year, P = 0.86). The mean accumulation rate of those with isolated abnormal cerebrospinal fluid was more than three times that of those with both normal cerebrospinal fluid and positron emission tomography (0.35%/year, P = 0.018). The group differences were similar when analysing yearly change in standardized uptake value ratio of florbetapir instead of percentage change. Those with both abnormal cerebrospinal fluid and positron emission tomography deteriorated more in memory and hippocampal volume compared with the other groups (P < 0.001), indicating that they were closer to Alzheimer’s disease dementia. The results were replicated after

  4. The diagnostic possibilities of positron emission tomography (PET): applications in oral and maxillofacial buccal oncology.

    PubMed

    Carranza-Pelegrina, Daniela; Lomeña-Caballero, Francisco; Soler-Peter, Marina; Berini-Aytés, Leonardo; Gay-Escoda, Cosme

    2005-01-01

    The principles of positron emission tomography (PET), recently introduced as a diagnostic procedure into the health sciences, are described. The principle clinical applications apply to a particular group of specialties: cardiology, neurology, psychiatry, and above all oncology. Positron emission tomography is a non-invasive diagnostic imaging technique with clinical applications. It is an excellent tool for the study of the stage and possible malignancy of tumors of head and neck, the detection of otherwise clinically indeterminate metastases and lymphadenopathies, and likewise for the diagnosis of relapses. The only tracer with any practical clinical application is fluor-desoxyglucosa-F18 (FDG). PET detects the intense accumulation of FDG produced in malignant tumors due to the increased glycolytic rate of the neoplastic cells. With the introduction of hybrid systems that combine computerized tomography or magnetic resonance with positron emission tomography, important advances are being made in the diagnosis and follow-up of oncologic pathology of head and neck.

  5. Distinguishing tumor recurrence from irradiation sequelae with positron emission tomography in patients treated for larynx cancer

    SciTech Connect

    Greven, K.M.; Williams, D.W. III; Keyes, J.W. Jr.; McGuirt, W.F.; Harkness, B.A.; Watson, N.E. Jr.; Raben, M.; Frazier, L.C.; Geisinger, K.R.; Capellari, J.O.

    1994-07-01

    Distinguishing persistent or recurrent tumor from postradiation edema, or soft tissue/cartilage necrosis in patients treated for carcinoma of the larynx can be difficult. Because recurrent tumor is often submucosal, multiple deep biopsies may be necessary before a diagnosis can be established. Positron emission tomography with 18F-2-fluro-2-deoxglucose (FDG) was studied for its ability to aid in this problem. Positron emission tomography (18FDG) scans were performed on 11 patients who were suspected of having persistent or recurrent tumor after radiation treatment for carcinoma of the larynx. Patients underwent thorough history and physical examinations, scans with computerized tomography, and pathologic evaluation when indicated. Standard uptake values were used to quantitate the FDG uptake in the larynx. The time between completion of radiation treatment and positron emission tomography examination ranged from 2 to 26 months with a median of 6 months. Ten patients underwent computed tomography (CT) of the larynx, which revealed edema of the larynx (six patients), glottic mass (four patients), and cervical nodes (one patient). Positron emission tomography scans revealed increased FDG uptake in the larynx in five patients and laryngectomy confirmed the presence of carcinoma in these patients. Five patients had positron emission tomography results consistent with normal tissue changes in the larynx, and one patient had increased FDG uptake in neck nodes. This patient underwent laryngectomy, and no cancer was found in the primary site, but nodes were pathologically positive. One patient had slightly elevated FDG uptake and negative biopsy results. The remaining patients have been followed for 11 to 14 months since their positron emission studies and their examinations have remained stable. In patients without tumor, average standard uptake values of the larynx ranged from 2.4 to 4.7, and in patients with tumor, the range was 4.9 to 10.7. 18 refs., 3 figs., 1 tab.

  6. The 511 keV emission from positron annihilation in the Galaxy

    SciTech Connect

    Prantzos, N.; Boehm, C.; Bykov, A. M.; Diehl, R.; Ferriere, K.; Guessoum, N.; Jean, P.; Knoedlseder, J.; Marcowith, A.; Moskalenko, I. V.; Strong, A.; Weidenspointner, G.

    2011-07-01

    The first {gamma}-ray line originating from outside the Solar System that was ever detected is the 511 keV emission from positron annihilation in the Galaxy. Despite 30 years of intense theoretical and observational investigation, the main sources of positrons have not been identified up to now. Observations in the 1990s with OSSE/CGRO (Oriented Scintillation Spectrometer Experiment on GRO satellite/Compton Gamma Ray Observatory) showed that the emission is strongly concentrated toward the Galactic bulge. In the 2000s, the spectrometer SPI aboard the European Space Agency's (ESA) International Gamma Ray Astrophysics Laboratory (INTEGRAL) allowed scientists to measure that emission across the entire Galaxy, revealing that the bulge-to-disk luminosity ratio is larger than observed at any other wavelength. This mapping prompted a number of novel explanations, including rather ''exotic'' ones (e.g., dark matter annihilation). However, conventional astrophysical sources, such as type Ia supernovae, microquasars, or x-ray binaries, are still plausible candidates for a large fraction of the observed total 511 keV emission of the bulge. A closer study of the subject reveals new layers of complexity, since positrons may propagate far away from their production sites, making it difficult to infer the underlying source distribution from the observed map of 511 keV emission. However, in contrast to the rather well-understood propagation of high-energy (>GeV) particles of Galactic cosmic rays, understanding the propagation of low-energy ({approx}MeV) positrons in the turbulent, magnetized interstellar medium still remains a formidable challenge. The spectral and imaging properties of the observed 511 keV emission are reviewed and candidate positron sources and models of positron propagation in the Galaxy are critically discussed.

  7. Early postischemic hyperperfusion: pathophysiologic insights from positron emission tomography.

    PubMed

    Marchal, G; Young, A R; Baron, J C

    1999-05-01

    Early postischemic hyperperfusion (EPIH) has long been documented in animal stroke models and is the hallmark of efficient recanalization of the occluded artery with subsequent reperfusion of the tissue (although occasionally it may be seen in areas bordering the hypoperfused area during arterial occlusion). In experimental stroke, early reperfusion has been reported to both prevent infarct growth and aggravate edema formation and hemorrhage, depending on the severity and duration of prior ischemia and the efficiency of reperfusion, whereas neuronal damage with or without enlarged infarction also may result from reperfusion (so-called "reperfusion injury"). In humans, focal hyperperfusion in the subacute stage (i.e., more than 48 hours after onset) has been associated with tissue necrosis in most instances, but regarding the acute stage, its occurrence, its relations with tissue metabolism and viability, and its clinical prognostic value were poorly understood before the advent of positron emission tomography (PET), in part because of methodologic issues. By measuring both CBF and metabolism, PET is an ideal imaging modality to study the pathophysiologic mechanism of EPIH. Although only a few PET studies have been performed in the acute stage that have systematically assessed tissue and clinical outcome in relation to EPIH, they have provided important insights. In one study, about one third of the patients with first-ever middle cerebral artery (MCA) territory stroke studied within 5 to 18 hours after symptom onset exhibited EPIH. In most cases, EPIH affected large parts of the cortical MCA territory in a patchy fashion, together with abnormal vasodilation (increased cerebral blood volume), "luxury perfusion" (decreased oxygen extraction fraction), and mildly increased CMRO2, which was interpreted as postischemic rebound of cellular metabolism in structurally preserved tissue. In that study, the spontaneous outcome of the tissue exhibiting EPIH was good, with late

  8. Molecular Imaging of Transporters with Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Antoni, Gunnar; Sörensen, Jens; Hall, Håkan

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

  9. A Unique Case of Increased 18F-FDG Metabolic Activity in the Soft Tissues of the Bilateral Upper Thighs Due to Immunizations in a Pediatric Patient

    PubMed Central

    Galloway, Terrel L.; Johnston, Mickaila J.; Starsiak, Michael D.; Silverman, Eugene D.

    2017-01-01

    A case of a 7-month-old white female who was referred for 18F-fluorodeoxyglucose (FDG) Positron emission tomography/computed tomography (PET/CT) initial evaluation of a lytic skull lesion with presumed diagnosis of Langerhans cell histiocytosis is described. Incidentally, she was found to have hypermetabolic nodules in the soft tissues of her anterior thighs. PMID:28217022

  10. Differences in lateral hemispheric asymmetries of glucose utilization between early- and late-onset Alzheimer-type dementia

    SciTech Connect

    Koss, E.; Friedland, R.P.; Ober, B.A.; Jagust, W.J.

    1985-05-01

    Positron emission tomography with (/sup 18/F)fluorodeoxyglucose revealed greater right than left hemispheric impairment of cortical glucose metabolism in patients with probable Alzheimer's disease who were younger than 65 but not in those over 65. This asymmetry was related to poor visuospatial performance.

  11. 77 FR 71803 - Guidance on Food and Drug Administration Oversight of Positron Emission Tomography Drug Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ... HUMAN SERVICES Food and Drug Administration Guidance on Food and Drug Administration Oversight of Positron Emission Tomography Drug Products--Questions and Answers; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing...

  12. 76 FR 60847 - Draft Guidance on Media Fills for Validation of Aseptic Preparations for Positron Emission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... for the Agency's current good manufacturing practice regulations for PET drugs. DATES: Although you... HUMAN SERVICES Food and Drug Administration Draft Guidance on Media Fills for Validation of Aseptic Preparations for Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug Administration,...

  13. 77 FR 11553 - Draft Guidance on Food and Drug Administration Oversight of Positron Emission Tomography Drug...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-27

    ... good manufacturing practices (CGMP) for PET drugs. The procedures were finalized and an implementation... HUMAN SERVICES Food and Drug Administration Draft Guidance on Food and Drug Administration Oversight of Positron Emission Tomography Drug Products--Questions and Answers; Availability AGENCY: Food and...

  14. A case of eosinophilic esophagitis discovered with positron emission tomography imaging: a case report

    PubMed Central

    2013-01-01

    Introduction Eosinophilic esophagitis was first reported in 1978, and since then it has been increasingly recognized as one of the major etiologies for dysphagia, food impaction, and food regurgitation. To the best of our knowledge, no case of eosinophilic esophagitis (excluding esophageal eosinophilia not responsive to proton pump inhibitor treatment) has previously been demonstrated on the basis of positron emission tomography imaging. Case presentation A 68-year-old Caucasian man presented with dysphagia to solids with recurrent regurgitation and weight loss of 7lb within the preceding 2 months. The patient attributed these symptoms to radiation therapy he had received 1 year earlier for squamous cell cancer of the lung. The patient underwent routine follow-up positron emission tomography imaging, which showed a hypermetabolic lesion in the posterior mediastinum and was increased at the level of the midesophagus. Conclusion To the best of our knowledge, this is the first reported case of eosinophilic esophagitis demonstrated by positron emission tomography imaging and confirmed with endoscopic evaluation and biopsies both after positron emission tomography imaging and a trial of proton pump inhibitor therapy. This could have an impact on the diagnostic evaluation of esophageal eosinophilic inflammation as well as eosinophilic infiltration of other gastrointestinal organs. PMID:23855975

  15. Functional-Lesion Investigation of Developmental Stuttering with Positron Emission Tomography.

    ERIC Educational Resources Information Center

    Ingham, Roger J.; And Others

    1996-01-01

    Analysis of use of positron emission tomographic measurements of resting-state regional cerebral blood flow in 29 men, 10 of whom stuttered, did not support the idea that developmental stuttering is associated with abnormalities of blood flow at rest. Findings did suggest an essentially normal functional brain terrain with a small number of minor…

  16. 76 FR 6144 - Positron Emission Tomography; Notice of Public Meeting; Request for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-03

    ... injection, ammonia N 13 injection, and sodium fluoride F 18 injection used in positron emission tomography... be submitted for FDG F 18 injection, ammonia N 13 injection, and sodium fluoride F 18 injection used..., ammonia N 13 injection, and sodium fluoride F 18 injection. FDA will present information designed...

  17. Attention Performance in Autism and Regional Brain Metabolic Rate Assessed by Positron Emission Tomography. Brief Report.

    ERIC Educational Resources Information Center

    Buchsbaum, M. S.; And Others

    1992-01-01

    This evaluation of seven high functioning adults with autism utilized positron emission tomography on a visual vigilance task. Although the subjects, as a group, did as well as normal controls on the task, there was a lack of normal hemispheric asymmetry in glucose metabolic rate. A heterogeneous etiology for autism is suggested to explain…

  18. Brain tumor imaging with synthesized /sup 18/F-fluorophenylalanine and positron emission tomography

    SciTech Connect

    Mineura, K.; Kowada, M.; Shishido, F.

    1989-06-01

    Two patients with cerebral gliomas were studied with 18F-fluorophenylalanine, newly synthesized by the electrophilic substitution reaction, using positron emission tomography. The tracer accumulated markedly in the tumor lesion and delineated the extent of the lesion. This new tracer will be promising in the diagnosis of gliomas.

  19. The Neural Correlates of Driving Performance Identified Using Positron Emission Tomography

    ERIC Educational Resources Information Center

    Horikawa, E.; Okamura, N.; Tashiro, M.; Sakurada, Y.; Maruyama, M.; Arai, H.; Yamaguchi, K.; Sasaki, H.; Yanai, K.; Itoh, M.

    2005-01-01

    Driving is a complex behavior involving multiple cognitive domains. To identify neural correlates of driving performance, [^1^5O]H"2O positron emission tomography was performed using a simulated driving task. Compared with the resting condition, simulated driving increased regional cerebral blood flow (rCBF) in the cerebellum, occipital, and…

  20. 77 FR 8262 - Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance on Investigational New Drug Applications for Positron Emission Tomography Drugs; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing the availability of a draft...

  1. Positron Emission Tomography Methods with Potential for Increased Understanding of Mental Retardation and Developmental Disabilities

    ERIC Educational Resources Information Center

    Sundaram, Senthil K.; Chugani, Harry T.; Chugani, Diane C.

    2005-01-01

    Positron emission tomography (PET) is a technique that enables imaging of the distribution of radiolabeled tracers designed to track biochemical and molecular processes in the body after intravenous injection or inhalation. New strategies for the use of radiolabeled tracers hold potential for imaging gene expression in the brain during development…

  2. Positron emission imaging device and method of using the same

    DOEpatents

    Bingham, Philip R.; Mullens, James Allen

    2013-01-15

    An imaging system and method of imaging are disclosed. The imaging system can include an external radiation source producing pairs of substantially simultaneous radiation emissions of a picturization emission and a verification emissions at an emission angle. The imaging system can also include a plurality of picturization sensors and at least one verification sensor for detecting the picturization and verification emissions, respectively. The imaging system also includes an object stage is arranged such that a picturization emission can pass through an object supported on said object stage before being detected by one of said plurality of picturization sensors. A coincidence system and a reconstruction system can also be included. The coincidence can receive information from the picturization and verification sensors and determine whether a detected picturization emission is direct radiation or scattered radiation. The reconstruction system can produce a multi-dimensional representation of an object imaged with the imaging system.

  3. Non-invasive studies of multiphase flow in process equipment. Positron emission particle tracking technique

    NASA Astrophysics Data System (ADS)

    Balakin, B. V.; Adamsen, T. C. H.; Chang, Y.-F.; Kosinski, P.; Hoffmann, A. C.

    2017-01-01

    Positron emission particle tracking (PEPT) is a novel experimental technique for non-invasive inspection of industrial fluid/particle flows. The method is based on the dynamic positioning of a positron-emitting, flowing object (particle) performed through the sensing of annihilation events and subsequent numerical treatment to determine the particle position. The present paper shows an integrated overview of PEPT studies which were carried out using a new PET scanner in the Bergen University Hospital to study multiphase flows in different geometric configurations.

  4. Current status and future needs for standards of radionuclides used in positron emission tomography.

    PubMed

    Zimmerman, B E

    2013-06-01

    Positron Emission Tomography (PET) is being increasingly used as a quantitative technique for detecting disease and monitoring patient progress during treatment. To ensure the validity of the quantitative information derived from the imaging data, it is imperative that all radioactivity measurements that are part of the imaging procedure be traceable to national or international standards. This paper reviews the current status of standards for positron emitting radionuclides (e.g., (18)F, (68)Ge/(68)Ga, and (124)I) and suggests needs for future work.

  5. Three-dimensional imaging of hidden objects using positron emission backscatter

    SciTech Connect

    Lee, Dongwon; Cowee, Misa; Fenimore, Ed; Galassi, Mark; Looker, Quinn; Mcneil, Wendy V; Stonehill, Laura; Wallace, Mark

    2009-01-01

    Positron emission backscatter imaging is a technique for interrogation and three-dimensional (3-D) reconstruction of hidden objects when we only have access to the objects from one side. Using time-of-flight differences in detected direct and backscattered positron-emitted photons, we construct 3-D images of target objects. Recently at Los Alamos National Laboratory, a fully three-dimensional imaging system has been built and the experimental results are discussed in this paper. Quantitative analysis of images reconstructed in both two- and three-dimensions are also presented.

  6. Asymmetric 511 keV Positron Annihilation Line Emission from the Inner Galactic Disk

    NASA Technical Reports Server (NTRS)

    Skinner, Gerry; Weidenspointner, Georg; Jean, Pierre; Knodlseder, Jurgen; Ballmoos, Perer von; Bignami, Giovanni; Diehl, Roland; Strong, Andrew; Cordier, Bertrand; Schanne, Stephane; Winkler, Christoph

    2008-01-01

    A recently reported asymmetry in the 511 keV gamma-ray line emission from the inner galactic disk is unexpected and mimics an equally unexpected one in the distribution of LMXBs seen at hard X-ray energies. A possible conclusion is that LMXBs are an important source of the positrons whose annihilation gives rise to the line. We will discuss these results, their statistical significance and that of any link between the two. The implication of any association between LMXBs and positrons for the strong annihilation radiation from the galactic bulge will be reviewed.

  7. Stability of regional cerebral glucose metabolism in the normal brain measured by positron emission tomography

    SciTech Connect

    Tyler, J.L.; Strother, S.C.; Zatorre, R.J.; Alivisatos, B.; Worsley, K.J.; Diksic, M.; Yamamoto, Y.L.

    1988-05-01

    Cerebral glucose utilization (LCMRGI) was measured using the (/sup 18/F)fluorodeoxyglucose method with PET in two groups of ten healthy young volunteers, each scanned in a resting state under different methodological conditions. In addition, five subjects had a second scan within 48 hr. Mean hemispheric values averaged 45.8 +/- 3.3 mumol/100 g/min in the right cerebral hemisphere and 47.0 +/- 3.7 mumol/100 g/min in the left hemisphere. A four-way analysis of variance (group, sex, region, hemisphere) was carried out on the results using three different methods of data manipulation: (a) the raw values of glucose utilization, (b) LCMRGI values normalized by the mean hemispheric gray matter LCMRGI value, and (c) log transformed LCMRGI values. For all analysis techniques, significantly higher LCMRGI values were consistently seen in the left mid and posterior temporal area and caudate nucleus relative to the right, and in the right occipital region relative to the left. The coefficient of variation of intrasubject regional differences (9.9%) was significantly smaller than the coefficient of variation for regions between subjects (16.5%). No differences were noted between the sexes and no effect of repeat procedures was seen in subjects having multiple scans. In addition, inter-regional LCMRGI correlations were examined both in values from the 20 normal subjects, as well as in a set of hypothetical abnormal values. Results were compared with those reported from other PET centers; despite certain methodological differences, the intersubject and inter-regional variation of LCMRGI is fairly constant.

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

    PubMed

    Vaquero, Juan José; Kinahan, Paul

    2015-01-01

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

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

    PubMed Central

    Vaquero, Juan José; Kinahan, Paul

    2017-01-01

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

  10. Radiopharmaceutical chemistry with iodine-124: a non-standard radiohalogen for positron emission tomography.

    PubMed

    Chacko, Ann-Marie; Divgi, Chaitanya R

    2011-09-01

    Positron emission tomography (PET) is a powerful molecular imaging technology with the ability to image and monitor molecular events in vivo and in real time. With the increased application of PET radiopharmaceuticals for imaging physiological and pathological processes in vivo, there is a demand for versatile positron emitters with longer physical and biological half-lives. Traditional PET radionuclides, such as carbon-11 ((11)C) and fluorine-18 ((18)F), have relatively short half-lives (20 min and 110 min, respectively). Among the currently available positron emitters, the non-standard radiohalogen iodine-124 ((124)I) has the longest physical half-life at 4.2 d. This, combined with the well characterized radiochemistry of radioiodine, is contributing to the increasing utility of (124)I in investigating slow and complex pharmacokinetic processes in clinical nuclear medicine and small animal PET imaging studies. This review will summarize the progress to date on the potential of (124)I as a positron emitting nuclide for molecular imaging purposes, beginning with the production of (124)I. Particular emphasis will be placed on the basic radiochemistry as it applies to the production of various (124)I-labeled compounds, from small molecules, to biomolecules such as peptides and proteins, and finally to macromolecules like nanoparticles. The review will conclude by highlighting promising future directions in using (124)I as a positron emitter in PET radiochemistry and molecular imaging.

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

    PubMed

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

    2017-03-28

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

  12. [Positron-emission tomography (PET)--basic considerations].

    PubMed

    von Schulthess, G K; Westera, G; Schubiger, P A

    1993-08-24

    A PET installation is a technically complex system composed essentially of two parts. The first consists in isotope production and synthesis of labeled biochemical compounds, the second in measuring the distribution of radioactivity in the body with the PET camera and the generation of image data. The specific advantage of PET lies on one hand in the use of positron emitters that are isotopes of ubiquitous elements in biologic matter, i.e. exact analogs of biomolecules can be produced and utilized and on the other hand quantification is possible. (= enable quantitative...?) Theoretically there are no limits for the synthesis of radioactive compounds and the method therefore provides unlimited test designs. The short half-life of the employed isotopes is advantageous for radioprotection reasons but the production of labeled compounds necessitates a cyclotron accelerator and a special laboratory for the handling of radioactive compounds rendering the production of the test substances relatively expensive. Measurements take place in a PET camera with a large number of coincidence detectors. The best available cameras have a spatial resolution of 5 mm in all three axes with an axial window of about 15 cm diameter. Evaluation of PET images is done in a qualitative way by superposition on anatomic images (CT, MRI) by image fusion. Quantitative determinations require elaborate computer modeling.

  13. Positron emission tomography detects tissue metabolic activity in myocardial segments with persistent thallium perfusion defects

    SciTech Connect

    Brunken, R.; Schwaiger, M.; Grover-McKay, M.; Phelps, M.E.; Tillisch, J.; Schelbert, H.R.

    1987-09-01

    Positron emission tomography with /sup 13/N-ammonia and /sup 18/F-2-deoxyglucose was used to assess myocardial perfusion and glucose utilization in 51 myocardial segments with a stress thallium defect in 12 patients. Myocardial infarction was defined by a concordant reduction in segmental perfusion and glucose utilization, and myocardial ischemia was identified by preservation of glucose utilization in segments with rest hypoperfusion. Of the 51 segments studied, 36 had a fixed thallium defect, 11 had a partially reversible defect and 4 had a completely reversible defect. Only 15 (42%) of the 36 segments with a fixed defect and 4 (36%) of the 11 segments with a partially reversible defect exhibited myocardial infarction on study with positron tomography. In contrast, residual myocardial glucose utilization was identified in the majority of segments with a fixed (58%) or a partially reversible (64%) thallium defect. All of the segments with a completely reversible defect appeared normal on positron tomography. Apparent improvement in the thallium defect on delayed images did not distinguish segments with ischemia from infarction. Thus, positron emission tomography reveals evidence of persistent tissue metabolism in the majority of segments with a fixed or partially resolving stress thallium defect, implying that markers of perfusion alone may underestimate the extent of viable tissue in hypoperfused myocardial segments.

  14. Positron emission tomography scanning is coming to a hospital near you soon!

    PubMed

    Bashir, Humayun; Shabo, Gregory; Nunan, T O

    2008-04-01

    Positron emission tomography (PET) is still generally not available in the UK; however, there are plans to introduce a national service in England from April 2008. Plans are also at an advanced stage in Scotland and Wales. The main uses of PET are in preoperative staging of lung cancer, detection of recurrent colorectal cancer, and management of patients with lymphoma. Although these provide the bulk of the referral base, PET is also of use in specific situations in patients with less common cancers, such as head and neck cancer, gynaecological cancer, and melanoma. In its more common uses, PET has been shown to be cost effective. Positron emission tomography will play an increasing role in the evaluation of response to treatment to enable early separation of patients who are responding well to chemotherapy from those who are not responding and need to be transferred to another therapy.

  15. Persistence of cerebral metabolic abnormalities in chronic schizophrenia as determined by positron emission tomography

    SciTech Connect

    Wolkin, A.; Jaeger, J.; Brodie, J.D.; Wolf, A.P.; Fowler, J.; Rotrosen, J.; Gomez-Mont, F.; Cancro, R.

    1985-05-01

    Local cerebral metabolic rates were determined by positron emission tomography and the deoxyglucose method in a group of 10 chronic schizophrenic subjects before and after somatic treatment and in eight normal subjects. Before treatment, schizophrenic subjects had markedly lower absolute metabolic activity than did normal controls in both frontal and temporal regions and a trend toward relative hyperactivity in the basal ganglia area. After treatment, their metabolic rates approached those seen in normal subjects in nearly all regions except frontal. Persistence of diminished frontal metabolism was manifested as significant relative hypofrontality. These findings suggest specific loci of aberrant cerebral functioning in chronic schizophrenia and the utility of positron emission tomography in characterizing these abnormalities.

  16. Pain and Opiate Receptors: Considerations for the Design of Positron Emission Tomography Studies

    PubMed Central

    Sadzot, B.; Frost, J. J.

    1990-01-01

    Opiate receptors in the brain are the target of endogenous opioids and of exogenous synthetic opiates. These receptors play a major role in the modulation of pain perception. Using the appropriate ligands, positron emission tomography now allows investigators to monitor neuroreceptors in vivo. We have used 11C-diprenorphine and the extremely potent mu opiate receptor agonist, 11C-carfentanil, to image the distribution of opiate receptors in the brain and to quantify their density, their affinity, and their occupancy. Several important aspects of the in vivo opiate receptor labeling with positron emission tomography in relation to the study of pain are considered in this paper. Monitoring receptor occupancy by opiate drugs as a function of pain relief has the potential to reveal better ways to treat pain. PMID:1964768

  17. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    SciTech Connect

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.

  18. Existing Pittsburgh Compound-B positron emission tomography thresholds are too high: statistical and pathological evaluation.

    PubMed

    Villeneuve, Sylvia; Rabinovici, Gil D; Cohn-Sheehy, Brendan I; Madison, Cindee; Ayakta, Nagehan; Ghosh, Pia M; La Joie, Renaud; Arthur-Bentil, Samia Kate; Vogel, Jacob W; Marks, Shawn M; Lehmann, Manja; Rosen, Howard J; Reed, Bruce; Olichney, John; Boxer, Adam L; Miller, Bruce L; Borys, Ewa; Jin, Lee-Way; Huang, Eric J; Grinberg, Lea T; DeCarli, Charles; Seeley, William W; Jagust, William

    2015-07-01

    Amyloid-β, a hallmark of Alzheimer's disease, begins accumulating up to two decades before the onset of dementia, and can be detected in vivo applying amyloid-β positron emission tomography tracers such as carbon-11-labelled Pittsburgh compound-B. A variety of thresholds have been applied in the literature to define Pittsburgh compound-B positron emission tomography positivity, but the ability of these thresholds to detect early amyloid-β deposition is unknown, and validation studies comparing Pittsburgh compound-B thresholds to post-mortem amyloid burden are lacking. In this study we first derived thresholds for amyloid positron emission tomography positivity using Pittsburgh compound-B positron emission tomography in 154 cognitively normal older adults with four complementary approaches: (i) reference values from a young control group aged between 20 and 30 years; (ii) a Gaussian mixture model that assigned each subject a probability of being amyloid-β-positive or amyloid-β-negative based on Pittsburgh compound-B index uptake; (iii) a k-means cluster approach that clustered subjects into amyloid-β-positive or amyloid-β-negative based on Pittsburgh compound-B uptake in different brain regions (features); and (iv) an iterative voxel-based analysis that further explored the spatial pattern of early amyloid-β positron emission tomography signal. Next, we tested the sensitivity and specificity of the derived thresholds in 50 individuals who underwent Pittsburgh compound-B positron emission tomography during life and brain autopsy (mean time positron emission tomography to autopsy 3.1 ± 1.8 years). Amyloid at autopsy was classified using Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria, unadjusted for age. The analytic approaches yielded low thresholds (standard uptake value ratiolow = 1.21, distribution volume ratiolow = 1.08) that represent the earliest detectable Pittsburgh compound-B signal, as well as high thresholds (standard

  19. Progressive degeneration of the right temporal lobe studied with positron emission tomography.

    PubMed Central

    Tyrrell, P J; Warrington, E K; Frackowiak, R S; Rossor, M N

    1990-01-01

    A 79 year old man with a twelve year progressive history of prosopagnosia and recent naming difficulty, in whom other intellectual skills were preserved, is described. Positron emission tomography (PET) revealed an area of right temporal lobe hypometabolism, with an additional area of less severe hypometabolism at the left temporal pole. This may represent an example of progressive focal cortical degeneration similar to that associated with primary progressive dysphasia, but affecting the right temporal lobe. Images PMID:2292695

  20. Investigation of the performance of the General Electric ADVANCE positron emission tomograph in 3D mode

    SciTech Connect

    Lewellen, T.K.; Kohlmyer, S.G.; Miyaoka, R.S.; Kaplan, M.S.; Stearns, C.W.; Schubert, S.F.

    1996-08-01

    Performance measurements of the General Electric ADVANCE Positron Emission Tomograph operating with the septa retracted (3D mode) were made. All reconstructions were performed with the GE ADVANCE 3D package. Performance tests were carried out with: the NEMA phantoms; a 3D Hoffman phantom; a Data Spectrum torso phantom with lung and cardiac inserts; and the Utah 3D evaluation phantom. Data collected included: transaxial and axial resolution, uniformity, recovery coefficients, count rate performance, dead time accuracy, and effect of scatter correction.

  1. Noninvasive measurement of regional myocardial glucose metabolism by positron emission computed tomography. [Dogs

    SciTech Connect

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

    1980-06-01

    While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography (/sup 13/N-ammonia) are promising, their utility and value remains to be determined in man. If this technique can be applied to patients with acute myocardial ischemia or infarction it may permit delineation of regional myocardial segments with altered, yet still active metabolism. Further, it may become possible to evaluate the effects of interventions designed to salvage reversibly injured myocardium by this technique.

  2. Positron emission tomography-computed tomography coregistration for diagnosis and intraoperative localization in recurrent nelson syndrome.

    PubMed

    Hintz, Eric B; Tomlin, Jeffery M; Chengazi, Vaseem; Vates, G Edward

    2013-06-01

    Recurrent pituitary disease presents unique challenges, including in some cases difficulty localizing a tumor radiographically. Here, we present the case of a patient with recurrent Nelson syndrome whose radiographic work-up was complicated by a significant parasellar metallic artifact. Positron emission tomography ultimately localized the lesion, and coregistration with computed tomography allowed for accurate intraoperative navigation. Additionally, we review a range of imaging techniques available in the evaluation of pituitary disease.

  3. Dynamic Positron Emission Tomography [PET] in Man Using Small Bismuth Germanate Crystals

    DOE R&D Accomplishments Database

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

    1982-04-01

    Primary considerations for the design of positron emission tomographs for medical studies in humans are the need for high imaging sensitivity, whole organ coverage, good spatial resolution, high maximum data rates, adequate spatial sampling with minimum mechanical motion, shielding against out of plane activity, pulse height discrimination against scattered photons, and timing discrimination against accidental coincidences. We discuss the choice of detectors, sampling motion, shielding, and electronics to meet these objectives.

  4. [Positron emission tomography in neuroscience. An integrative part of clinical diagnostic methods and experimental research].

    PubMed

    Schaller, B

    2005-02-01

    The role of molecular neuroimaging techniques is increasing in the understanding of pathophysiological mechanism of diseases. To date, positron emission tomography is the most powerful tool for the non-invasive study of biochemical and molecular processes in humans and animals in vivo. With the development in radiochemistry and tracer technology, a variety of endogenously expressed and exogenously introduced genes can be analyzed by PET. This opens up the exciting and rapidly field of molecular imaging, aiming at the non-invasive localisation of a biological process of interest in normal and diseased cells in animal models and humans in vivo. Besides its usefulness for basic research positron emission tomography has been proven to be superior to conventional diagnostic methods in several clinical indications. This is illustrated by detection of biological or anatomic changes that cannot be demonstrated by computed tomography or magnetic resonance imaging, as well as even before symptoms are expressed. The present review summarizes the clinical use of positron emission tomography in neuroscience that has helped elucidate the pathophysiology of a number of diseases and has suggested strategies in the treatment of these patients. Special reference is given to the neurovascular, neurodegenerative and neurooncological disease.

  5. Targeted positron emission tomography imaging of CXCR4 expression in patients with acute myeloid leukemia.

    PubMed

    Herhaus, Peter; Habringer, Stefan; Philipp-Abbrederis, Kathrin; Vag, Tibor; Gerngross, Carlos; Schottelius, Margret; Slotta-Huspenina, Julia; Steiger, Katja; Altmann, Torben; Weißer, Tanja; Steidle, Sabine; Schick, Markus; Jacobs, Laura; Slawska, Jolanta; Müller-Thomas, Catharina; Verbeek, Mareike; Subklewe, Marion; Peschel, Christian; Wester, Hans-Jürgen; Schwaiger, Markus; Götze, Katharina; Keller, Ulrich

    2016-08-01

    Acute myeloid leukemia originates from leukemia-initiating cells that reside in the protective bone marrow niche. CXCR4/CXCL12 interaction is crucially involved in recruitment and retention of leukemia-initiating cells within this niche. Various drugs targeting this pathway have entered clinical trials. To evaluate CXCR4 imaging in acute myeloid leukemia, we first tested CXCR4 expression in patient-derived primary blasts. Flow cytometry revealed that high blast counts in patients with acute myeloid leukemia correlate with high CXCR4 expression. The wide range of CXCR4 surface expression in patients was reflected in cell lines of acute myeloid leukemia. Next, we evaluated the CXCR4-specific peptide Pentixafor by positron emission tomography imaging in mice harboring CXCR4 positive and CXCR4 negative leukemia xenografts, and in 10 patients with active disease. [(68)Ga]Pentixafor-positron emission tomography showed specific measurable disease in murine CXCR4 positive xenografts, but not when CXCR4 was knocked out with CRISPR/Cas9 gene editing. Five of 10 patients showed tracer uptake correlating well with leukemia infiltration assessed by magnetic resonance imaging. The mean maximal standard uptake value was significantly higher in visually CXCR4 positive patients compared to CXCR4 negative patients. In summary, in vivo molecular CXCR4 imaging by means of positron emission tomography is feasible in acute myeloid leukemia. These data provide a framework for future diagnostic and theranostic approaches targeting the CXCR4/CXCL12-defined leukemia-initiating cell niche.

  6. Targeted positron emission tomography imaging of CXCR4 expression in patients with acute myeloid leukemia

    PubMed Central

    Herhaus, Peter; Habringer, Stefan; Philipp-Abbrederis, Kathrin; Vag, Tibor; Gerngross, Carlos; Schottelius, Margret; Slotta-Huspenina, Julia; Steiger, Katja; Altmann, Torben; Weißer, Tanja; Steidle, Sabine; Schick, Markus; Jacobs, Laura; Slawska, Jolanta; Müller-Thomas, Catharina; Verbeek, Mareike; Subklewe, Marion; Peschel, Christian; Wester, Hans-Jürgen; Schwaiger, Markus; Götze, Katharina; Keller, Ulrich

    2016-01-01

    Acute myeloid leukemia originates from leukemia-initiating cells that reside in the protective bone marrow niche. CXCR4/CXCL12 interaction is crucially involved in recruitment and retention of leukemia-initiating cells within this niche. Various drugs targeting this pathway have entered clinical trials. To evaluate CXCR4 imaging in acute myeloid leukemia, we first tested CXCR4 expression in patient-derived primary blasts. Flow cytometry revealed that high blast counts in patients with acute myeloid leukemia correlate with high CXCR4 expression. The wide range of CXCR4 surface expression in patients was reflected in cell lines of acute myeloid leukemia. Next, we evaluated the CXCR4-specific peptide Pentixafor by positron emission tomography imaging in mice harboring CXCR4 positive and CXCR4 negative leukemia xenografts, and in 10 patients with active disease. [68Ga]Pentixafor-positron emission tomography showed specific measurable disease in murine CXCR4 positive xenografts, but not when CXCR4 was knocked out with CRISPR/Cas9 gene editing. Five of 10 patients showed tracer uptake correlating well with leukemia infiltration assessed by magnetic resonance imaging. The mean maximal standard uptake value was significantly higher in visually CXCR4 positive patients compared to CXCR4 negative patients. In summary, in vivo molecular CXCR4 imaging by means of positron emission tomography is feasible in acute myeloid leukemia. These data provide a framework for future diagnostic and theranostic approaches targeting the CXCR4/CXCL12-defined leukemia-initiating cell niche. PMID:27175029

  7. Aspects of positron emission tomography radiochemistry as relevant for food chemistry.

    PubMed

    Wuest, F

    2005-12-01

    Positron emission tomography (PET) is a medical imaging technique using compounds labelled with short-lived positron emitting radioisotopes to obtain functional information of physiological, biochemical and pharmacological processes in vivo. The need to understand the potential link between the ingestion of individual dietary agents and the effect of health promotion or health risk requires the exact metabolic characterization of food ingredients in vivo. This exciting but rather new research field of PET would provide new insights and perspectives on food chemistry by assessing quantitative information on pharmocokinetics and pharmacodynamics of food ingredients and dietary agents. To fully exploit PET technology in food chemistry appropriately radiolabelled compounds as relevant for food sciences are needed. The most widely used short-lived positron emitters are (11)C (t(1/2) = 20.4 min) and (18)F (t(1/2) = 109.8 min). Longer-lived radioisotopes are available by using (76)Br (t(1/2) = 16.2 h) and (124)I (t(1/2) = 4.12 d). The present review article tries to discuss some aspects for the radiolabelling of food ingredients and dietary agents either by means of isotopic labelling with (11)C or via prosthetic group labelling approaches using the positron emitting halogens (18)F, (76)Br and (124)I.

  8. A Pilot Study Treatment of Malignant Tumors Using [18F] Fluorodeoxyglucose (FDG)

    ClinicalTrials.gov

    2016-08-18

    Radiosensitive Stage IV Solid and Hematological Tumors With High FDG Uptake Not Responding to Standard of Care; Lung Cancer, Head and Neck Cancer, Breast Cancer, Gastric Cancer, Pancreatic Cancer, Colon Cancer, Lymphomas, Sarcomas, Etc

  9. Age and sex differences in cerebral glucose consumption measured by pet using (18-F) fluorodeoxyglucose (FDG)

    SciTech Connect

    Duara, R.; Barker, W.; Chang, J.; Apicella, A.; Finn, R.; Gilson, A.

    1985-05-01

    Resting cerebral glucose metabolic rates (CMRglc) were measured in 23 subjects by PET using FDG. Subjects were divided into several groups (mean age +- S.D.) 5 young males (YM) (27 +- 6); 6 young females (YF)(33 +9); 5 elderly males (EM)(73 +- 5); 7 elderly females (EF)(69 +- 7). Additionally, from these groups 4 YM, 3YF, 5EM and 4EF were studied again within 6 weeks under identical conditions. CMRglc in the YF group again was significantly hider than YM (p 0.05). No obvious relationships of CMRglc to the phase of the menstrual cycle was found in this small group. There was a trend (p=0.06) toward a higher CMRglc in YF than EF. These results support the findings of higher CBF in YF versus YM. The differences between the results of Kuhl et al (J. Cereb. and a reduction of CMRglc with age was found in a mixed group of males and females (58and female), and where no age effect was found the males, are also resolved by these findings. The authors suggest that the apparent age effect, in females in this study, is principally a hormonal one.

  10. High-resolution PET (positron emission tomography) for medical science studies

    SciTech Connect

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

    1989-09-01

    One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging. 6 refs., 21 figs.

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

    DOE R&D Accomplishments Database

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

    1989-09-01

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

  12. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons

    NASA Astrophysics Data System (ADS)

    Sato, K.; Kobayashi, Y.

    2015-05-01

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

  13. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons.

    PubMed

    Sato, K; Kobayashi, Y

    2015-05-01

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

  14. Synthesis and characterisation of zirconium complexes for cell tracking with Zr-89 by positron emission tomography.

    PubMed

    Ferris, Trevor J; Charoenphun, Putthiporn; Meszaros, Levente K; Mullen, Gregory E D; Blower, Philip J; Went, Michael J

    2014-10-21

    The increasing availability of the long half-life positron emitter Zr-89 (half life 78.4 h) suggests that it is a strong candidate for cell labelling and hence cell tracking using positron emission tomography. The aim was to produce a range of neutral ZrL4 lipophilic complexes for cell labelling which could be prepared under radiopharmaceutical conditions. This was achieved when the ligand was oxine, tropolone or ethyl maltol. The complexes can be prepared in high yield from zirconium(iv) precursors in hydrochloric or oxalic acid solution. The oxinate and tropolonate complexes were the most amenable to chromatographic characterisation, and HPLC and ITLC protocols have been established to monitor their radiochemical purity. The radiochemical synthesis and quality control of (89)Zr(oxinate)4 is reported as well as preliminary cell labelling data for the oxinate, tropolonate and ethyl maltolate complexes which indicates that (89)Zr(oxinate)4 is the most promising candidate for further evaluation.

  15. Enhancement of molecular sensitivity in positron emission tomography with quantum correlation of γ-ray photons

    SciTech Connect

    Sato, K.; Kobayashi, Y.

    2015-05-15

    Enhancement of molecular sensitivity in positron emission tomography (PET) has long been discussed with respect to imaging instrumentation and algorithms for data treatment. Here, the molecular sensitivity in PET is discussed on the basis of 2-dimensional coincident measurements of 511 keV γ ray photons resultant from two-photon annihilation. Introduction of an additional selection window based on the energy sum and difference of the coincidently measured γ ray photons, without any significant instrumental and algorithmic changes, showed an improvement in the signal-to-noise ratio (SNR) by an order of magnitude. Improvement of performance characteristics in the PET imaging system was demonstrated by an increase in the noise equivalent count rate (NECR) which takes both the SNR and the detection efficiency into consideration. A further improvement of both the SNR and the NECR is expected for the present system in real clinical and in-vivo environments, where much stronger positron sources are employed.

  16. Brain energy metabolism and dopaminergic function in Huntington's disease measured in vivo using positron emission tomography.

    PubMed

    Leenders, K L; Frackowiak, R S; Quinn, N; Marsden, C D

    1986-01-01

    A 48-year-old man with typical Huntington's disease was investigated with computed tomography (CT) and positron emission tomography. Regional cerebral blood flow, oxygen extraction, oxygen and glucose utilisation, L-Dopa uptake, and dopamine (D2) receptor binding were measured using several positron-labelled tracers. CT showed slight atrophy of the head of caudate but no cortical atrophy, although distinct frontal lobe dysfunction was present on psychometric testing. Oxygen and glucose metabolism and cerebral blood flow were decreased in the striata and to a lesser extent in frontal cortex. Cerebral blood flow was in the low normal range throughout the remainder of the brain. A normal metabolic ratio was found in all regions, since the changes in glucose utilisation paralleled those in oxygen consumption. The capacity of the striatum to store dopamine as assessed by L-[18F]-fluorodopa uptake was normal, but dopamine (D2) receptor binding was decreased when compared to normal subjects.

  17. Brain energy metabolism and dopaminergic function in Huntington's disease measured in vivo using positron emission tomography

    SciTech Connect

    Leenders, K.L.; Frackowiak, R.S.; Quinn, N.; Marsden, C.D.

    1986-01-01

    A 48-year-old man with typical Huntington's disease was investigated with computed tomography (CT) and positron emission tomography. Regional cerebral blood flow, oxygen extraction, oxygen and glucose utilization, L-Dopa uptake, and dopamine (D2) receptor binding were measured using several positron-labelled tracers. CT showed slight atrophy of the head of caudate but no cortical atrophy, although distinct frontal lobe dysfunction was present on psychometric testing. Oxygen and glucose metabolism and cerebral blood flow were decreased in the striata and to a lesser extent in frontal cortex. Cerebral blood flow was in the low normal range throughout the remainder of the brain. A normal metabolic ratio was found in all regions, since the changes in glucose utilization paralleled those in oxygen consumption. The capacity of the striatum to store dopamine as assessed by L-( YF)-fluorodopa uptake was normal, but dopamine (D2) receptor binding was decreased when compared to normal subjects.

  18. FEASIBILITY OF POSITRON EMISSION TOMOGRAPHY OF DOSE DISTRIBUTION IN PROTON BEAM CANCER THERAPY.

    SciTech Connect

    BEEBE - WANG,J.J.; DILMANIAN,F.A.; PEGGS,S.G.; SCHLYEER,D.J.; VASKA,P.

    2002-06-03

    Proton therapy is a treatment modality of increasing utility in clinical radiation oncology mostly because its dose distribution conforms more tightly to the target volume than x-ray radiation therapy. One important feature of proton therapy is that it produces a small amount of positron-emitting isotopes along the beam-path through the non-elastic nuclear interaction of protons with target nuclei such as {sup 12}C, {sup 14}N, and {sup 16}O. These radioisotopes, mainly {sup 11}C, {sup 13}N and {sup 15}O, allow imaging the therapy dose distribution using positron emission tomography (PET). The resulting PET images provide a powerful tool for quality assurance of the treatment, especially when treating inhomogeneous organs such as the lungs or the head-and-neck, where the calculation of the dose distribution for treatment planning is more difficult. This paper uses Monte Carlo simulations to predict the yield of positron emitters produced by a 250 MeV proton beam, and to simulate the productions of the image in a clinical PET scanner.

  19. Positron emission tomography (PET) imaging with 18F-based radiotracers

    PubMed Central

    Alauddin, Mian M

    2012-01-01

    Positron Emission Tomography (PET) is a nuclear medicine imaging technique that is widely used in early detection and treatment follow up of many diseases, including cancer. This modality requires positron-emitting isotope labeled biomolecules, which are synthesized prior to perform imaging studies. Fluorine-18 is one of the several isotopes of fluorine that is routinely used in radiolabeling of biomolecules for PET; because of its positron emitting property and favorable half-life of 109.8 min. The biologically active molecule most commonly used for PET is 2-deoxy-2-18F-fluoro-β-D-glucose (18F-FDG), an analogue of glucose, for early detection of tumors. The concentrations of tracer accumulation (PET image) demonstrate the metabolic activity of tissues in terms of regional glucose metabolism and accumulation. Other tracers are also used in PET to image the tissue concentration. In this review, information on fluorination and radiofluorination reactions, radiofluorinating agents, and radiolabeling of various compounds and their application in PET imaging is presented. PMID:23133802

  20. Positron emission tomographic imaging of tumors using monoclonal antibodies. Progress report, April 15, 1992--October 31, 1992

    SciTech Connect

    Zalutsky, M.R.

    1992-08-01

    This research project is developing methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). This report describes the development of methods for labeling MAbs and their fragments with positron-emitting halogen nuclides, fluorine-18 and iodine-124. These nulides were selected because of the widespread availability of F-18 and because of our extensive experience in the development of new protein radiohalogenation methods.

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

    PubMed

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

    2006-02-01

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

  2. Positron emission tomography and computed tomography assessments of the aging human brain

    SciTech Connect

    de Leon, M.J.; George, A.E.; Ferris, S.H.; Christman, D.R.; Fowler, J.S.; Gentes, C.I.; Brodie, J.; Reisberg, B.; Wolf, A.P.

    1984-02-01

    The relationship between alterations in brain structure and brain function was studied in vivo in both young and elderly human subjects. Computed tomography revealed significant age-related ventricular and cortical sulcal dilatation. The cortical changes were most closely related to age. Positron emission tomography failed to show regional changes in brain glucose metabolic rate. The results suggest that the normal aging brain undergoes structural atrophic changes without incurring regional metabolic changes. Examination of the correlations between the structural and the metabolic measures revealed no significant relationships. These data are discussed with respect to the significant structure-function relationships that have been reported in Alzheimer disease. 27 references, 3 figures, 2 tables.

  3. Evidence for a dopaminergic deficit in sporadic amyotrophic lateral sclerosis on positron emission scanning

    SciTech Connect

    Takahashi, Hirohide; Snow, B.J.; Bhatt, M.H.; Peppard, R.; Eisen, A.; Calne, D.B. )

    1993-10-23

    Although rare, the chronic neurodegenerative disorders amyotrophic lateral sclerosis (ALS) and idiopathic parkinsonism coexist to a greater degree than expected by chance. This suggests that patients with ALS may have subclinical lesions of the nigrostriatal dopaminergic pathway. To study this hypothesis, the authors did positron emission tomography with 6-fluorodopa on 16 patients with sporadic ALS and without extrapyramidal disease, and compared the results with age-matched controls. They found a significant progressive fall in 6-fluorodopa uptake with time since diagnosis, and reduced dopaminergic function in 3 patients with ALS of long duration. This supports the hypothesis that ALS and IP may share pathogenesis, and, perhaps, etiology.

  4. [Principles and applications of positron emission tomography (PET) in cardiology. PET in Mexico: a reality].

    PubMed

    Alexanderson Rosas, Erick; Kerik, Nora E; Unzek Freiman, Samuel; Fermon Schwaycer, Salomón

    2002-01-01

    Positron emission tomography (PET) offers the unique capability of measuring non-invasive by the regional myocardial substrate flow and the biochemical reaction index in millimol per minute per gram of myocardial tissue. PET also allows for the assessment or quantification of regional myocardial blood flow, cardiac metabolism, ventricular function, myocardial viability, as well as autonomous nervous system, research and evaluating of dilated myocardiopathy and of ventricular hypertrophy. PET's success is based on the radioisotopes properties, their very short half-life allows for the administration of large doses.

  5. Revocation of regulation on positron emission tomography drug products--FDA. Final rule; revocation.

    PubMed

    1997-12-19

    The Food and Drug Administration (FDA) is revoking a regulation on positron emission tomography (PET) radiopharmaceutical drug products. The regulation permits FDA to approve requests from manufacturers of PET drugs for exceptions or alternatives to provisions of the current good manufacturing practice (CGMP) regulations. FDA is taking this action in accordance with provisions of the Food and Drug Administration Modernization Act of 1997 (Modernization Act). Elsewhere in this issue of the Federal Register, FDA is publishing a notice revoking two notices concerning certain guidance documents on PET drugs and the guidance documents to which the notices relate.

  6. Florbetapir (18F) for brain amyloid positron emission tomography: highlights on the European marketing approval.

    PubMed

    Cortes-Blanco, Anabel; Prieto-Yerro, Concha; Martinez-Lazaro, Raul; Zamora, Javier; Jiménez-Huete, Adolfo; Haberkamp, Marion; Pohly, Johannes; Enzmann, Harald; Zinserling, Jörg; Strassmann, Valerie; Broich, Karl

    2014-10-01

    Florbetapir (18F) for brain amyloid positron emission tomography (PET) imaging has been recently approved in Europe to estimate β-amyloid neuritic plaque density in the brain when the subject is still alive. Such density is one of the key issues for the definitive diagnosis of Alzheimer's disease (AD) at autopsy. This capability of florbetapir (18F) is regarded as a significant improvement in the diagnostic procedures for adult patients with cognitive impairment who are being evaluated for AD and other causes of cognitive impairment. The current paper highlights the specific characteristics of the European marketing authorization of florbetapir (18F).

  7. Clinical correlates of decreased anteroposterior metabolic gradients in positron emission tomography (PET) of schizophrenic patients

    SciTech Connect

    DeLisi, L.E.; Buchsbaum, M.S.; Holcomb, H.H.; Dowling-Zimmerman, S.; Pickar, D.; Boronow, J.; Morihisa, J.M.; van Kammen, D.P.; Carpenter, W.; Kessler, R.

    1985-01-01

    The finding in schizophrenic patients of a reversal of the normal frontal to posterior pattern of brain metabolic activity with positron emission tomography (PET) is of interest, but its relevance to psychopathology is unknown. Using PET, the authors studied 21 patients with chronic schizophrenia and 21 age- and sex-matched control subjects. Although eight of the 21 patients and only one of the control subjects showed a relatively lower anteroposterior metabolic gradient, no clinical correlates of this finding were noted. In addition, cerebral atrophy, as determined by CAT scan, was not associated with this aberrant metabolic pattern.

  8. Positron emission tracking of individual particles in particle-laden rimming flow

    SciTech Connect

    Denissenko, P. Thomas, P. J.; Guyez, E.; Parker, D. J.; Seville, J. P. K.

    2014-05-15

    The motion of a single tracer particle in particle-laden rimming flows is investigated experimentally by means of Positron Emission Particle Tracking (PEPT). Semi-dilute suspensions, with a volume fraction of 8% of heavy particles are considered. The trajectory of the tracer particle is monitored for several thousand cylinder revolutions and related to the optically recorded drift of the large-scale granular segregation bands developing in the cylinder. Results of the data analysis provide first insights into the relation between behaviour of individual particles and the spatiotemporal dynamics displayed by the macroscopic particle-segregation patterns.

  9. Neuro-imaging and positron emission tomography of congenital homonymous hemianopsia.

    PubMed

    Bosley, T M; Kiyosawa, M; Moster, M; Harbour, R; Zimmerman, R; Savino, P J; Sergott, R C; Alavi, A; Reivich, M

    1991-04-15

    Congenital homonymous hemianopsia is an uncommon asymptomatic visual field defect discovered typically in young adult life that is caused by a diverse group of insults to the retrochiasmal afferent visual system occurring prenatally, at birth, or during early childhood. We treated eight patients with congenital homonymous hemianopsia; seven with damage involving the optic radiations and one with an abnormality of the optic tract. We performed positron emission tomography using 18F-fluoro-2-deoxyglucose on two patients with dense homonymous hemianopsias, lesions of the contralateral optic radiations, and largely intact occipital cortex. These studies showed minimal abnormalities in resting visual cortex glucose metabolism of the affected visual cortex.

  10. Distributed Microprocessor Automation Network for Synthesizing Radiotracers Used in Positron Emission Tomography [PET

    DOE R&D Accomplishments Database

    Russell, J. A. G.; Alexoff, D. L.; Wolf, A. P.

    1984-09-01

    This presentation describes an evolving distributed microprocessor network for automating the routine production synthesis of radiotracers used in Positron Emission Tomography. We first present a brief overview of the PET method for measuring biological function, and then outline the general procedure for producing a radiotracer. The paper identifies several reasons for our automating the syntheses of these compounds. There is a description of the distributed microprocessor network architecture chosen and the rationale for that choice. Finally, we speculate about how this network may be exploited to extend the power of the PET method from the large university or National Laboratory to the biomedical research and clinical community at large. (DT)

  11. Treatment modification of yttrium-90 radioembolization based on quantitative positron emission tomography/CT imaging.

    PubMed

    Chang, Ted T; Bourgeois, Austin C; Balius, Anastasia M; Pasciak, Alexander S

    2013-03-01

    Treatment activity for yttrium-90 ((90)Y) radioembolization when calculated by using the manufacturer-recommended technique is only partially patient-specific and may result in a subtumoricidal dose in some patients. The authors describe the use of quantitative (90)Y positron emission tomography/computed tomography as a tool to provide patient-specific optimization of treatment activity and evaluate this new method in a patient who previously received traditional (90)Y radioembolization. The modified treatment resulted in a 40-Gy increase in absorbed dose to tumor and complete resolution of disease in the treated area within 3 months.

  12. Reliability of eye lens dosimetry in workers of a positron emission tomography radiopharmaceutical production facility.

    PubMed

    da Silva, Teógenes A; Guimarães, Margarete C; Meireles, Leonardo S; Teles, Luciana L D; Lacerda, Marco Aurélio S

    2016-11-01

    A new regulatory statement was issued concerning the eye lens radiation protection of persons in planned exposures. A debate was raised on the adequacy of the dosimetric quantity and on its method of measurement. The aim of this work was to establish the individual monitoring procedure with the EYE-D™ holder and a MCP-N LiF:Mg,Cu,P thermoluminescent chip detector for measuring the personal dose equivalent Hp(3) in workers of a Positron Emission Tomography Radiopharmaceutical Production Facility.

  13. Positron Emission Tomography-Scanner at Children`s Hospital of Michigan at Detroit, Michigan

    SciTech Connect

    Not Available

    1992-12-31

    The Department of Energy has prepared an environmental assessment (EA), DOE/EA-0795, to support the DOE decision to provide a grant of $7,953,600 to be used in support of a proposed Positron Emission Tomography Scanner at Children`s Hospital of Michigan at Detroit, Michigan. Based upon the analysis in the EA, DOE has determined that the proposed action is not a major Federal action significantly affected the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI).

  14. Intraprocedural yttrium-90 positron emission tomography/CT for treatment optimization of yttrium-90 radioembolization.

    PubMed

    Bourgeois, Austin C; Chang, Ted T; Bradley, Yong C; Acuff, Shelley N; Pasciak, Alexander S

    2014-02-01

    Radioembolization with yttrium-90 ((90)Y) microspheres relies on delivery of appropriate treatment activity to ensure patient safety and optimize treatment efficacy. We report a case in which (90)Y positron emission tomography (PET)/computed tomography (CT) was performed to optimize treatment planning during a same-day, three-part treatment session. This treatment consisted of (i) an initial (90)Y infusion with a dosage determined using an empiric treatment planning model, (ii) quantitative (90)Y PET/CT imaging, and (iii) a secondary infusion with treatment planning based on quantitative imaging data with the goal of delivering a specific total tumor absorbed dose.

  15. ROC (Receiver Operating Characteristics) study of maximum likelihood estimator human brain image reconstructions in PET (Positron Emission Tomography) clinical practice

    SciTech Connect

    Llacer, J.; Veklerov, E.; Nolan, D. ); Grafton, S.T.; Mazziotta, J.C.; Hawkins, R.A.; Hoh, C.K.; Hoffman, E.J. )

    1990-10-01

    This paper will report on the progress to date in carrying out Receiver Operating Characteristics (ROC) studies comparing Maximum Likelihood Estimator (MLE) and Filtered Backprojection (FBP) reconstructions of normal and abnormal human brain PET data in a clinical setting. A previous statistical study of reconstructions of the Hoffman brain phantom with real data indicated that the pixel-to-pixel standard deviation in feasible MLE images is approximately proportional to the square root of the number of counts in a region, as opposed to a standard deviation which is high and largely independent of the number of counts in FBP. A preliminary ROC study carried out with 10 non-medical observers performing a relatively simple detectability task indicates that, for the majority of observers, lower standard deviation translates itself into a statistically significant detectability advantage in MLE reconstructions. The initial results of ongoing tests with four experienced neurologists/nuclear medicine physicians are presented. Normal cases of {sup 18}F -- fluorodeoxyglucose (FDG) cerebral metabolism studies and abnormal cases in which a variety of lesions have been introduced into normal data sets have been evaluated. We report on the results of reading the reconstructions of 90 data sets, each corresponding to a single brain slice. It has become apparent that the design of the study based on reading single brain slices is too insensitive and we propose a variation based on reading three consecutive slices at a time, rating only the center slice. 9 refs., 2 figs., 1 tab.

  16. Sensitivity estimation in time-of-flight list-mode positron emission tomography

    SciTech Connect

    Herraiz, J. L.; Sitek, A.

    2015-11-15

    Purpose: An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only. Methods: The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated. Results: The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data. Conclusions: A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data.

  17. Sensitivity estimation in time-of-flight list-mode positron emission tomography

    PubMed Central

    Herraiz, J. L.; Sitek, A.

    2015-01-01

    Purpose: An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only. Methods: The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated. Results: The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data. Conclusions: A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data. PMID:26520759

  18. Pixelated CdTe detectors to overcome intrinsic limitations of crystal based positron emission mammographs

    NASA Astrophysics Data System (ADS)

    De Lorenzo, G.; Chmeissani, M.; Uzun, D.; Kolstein, M.; Ozsahin, I.; Mikhaylova, E.; Arce, P.; Cañadas, M.; Ariño, G.; Calderón, Y.

    2013-01-01

    A positron emission mammograph (PEM) is an organ dedicated positron emission tomography (PET) scanner for breast cancer detection. State-of-the-art PEMs employing scintillating crystals as detection medium can provide metabolic images of the breast with significantly higher sensitivity and specificity with respect to standard whole body PET scanners. Over the past few years, crystal PEMs have dramatically increased their importance in the diagnosis and treatment of early stage breast cancer. Nevertheless, designs based on scintillators are characterized by an intrinsic deficiency of the depth of interaction (DOI) information from relatively thick crystals constraining the size of the smallest detectable tumor. This work shows how to overcome such intrinsic limitation by substituting scintillating crystals with pixelated CdTe detectors. The proposed novel design is developed within the Voxel Imaging PET (VIP) Pathfinder project and evaluated via Monte Carlo simulation. The volumetric spatial resolution of the VIP-PEM is expected to be up to 6 times better than standard commercial devices with a point spread function of 1 mm full width at half maximum (FWHM) in all directions. Pixelated CdTe detectors can also provide an energy resolution as low as 1.5% FWHM at 511 keV for a virtually pure signal with negligible contribution from scattered events.

  19. Pixelated CdTe detectors to overcome intrinsic limitations of crystal based positron emission mammographs.

    PubMed

    De Lorenzo, G; Chmeissani, M; Uzun, D; Kolstein, M; Ozsahin, I; Mikhaylova, E; Arce, P; Cañadas, M; Ariño, G; Calderón, Y

    2013-01-01

    A positron emission mammograph (PEM) is an organ dedicated positron emission tomography (PET) scanner for breast cancer detection. State-of-the-art PEMs employing scintillating crystals as detection medium can provide metabolic images of the breast with significantly higher sensitivity and specificity with respect to standard whole body PET scanners. Over the past few years, crystal PEMs have dramatically increased their importance in the diagnosis and treatment of early stage breast cancer. Nevertheless, designs based on scintillators are characterized by an intrinsic deficiency of the depth of interaction (DOI) information from relatively thick crystals constraining the size of the smallest detectable tumor. This work shows how to overcome such intrinsic limitation by substituting scintillating crystals with pixelated CdTe detectors. The proposed novel design is developed within the Voxel Imaging PET (VIP) Pathfinder project and evaluated via Monte Carlo simulation. The volumetric spatial resolution of the VIP-PEM is expected to be up to 6 times better than standard commercial devices with a point spread function of 1 mm full width at half maximum (FWHM) in all directions. Pixelated CdTe detectors can also provide an energy resolution as low as 1.5% FWHM at 511 keV for a virtually pure signal with negligible contribution from scattered events.

  20. Pixelated CdTe detectors to overcome intrinsic limitations of crystal based positron emission mammographs

    PubMed Central

    De Lorenzo, G.; Chmeissani, M.; Uzun, D.; Kolstein, M.; Ozsahin, I.; Mikhaylova, E.; Arce, P.; Cañadas, M.; Ariño, G.; Calderón, Y.

    2013-01-01

    A positron emission mammograph (PEM) is an organ dedicated positron emission tomography (PET) scanner for breast cancer detection. State-of-the-art PEMs employing scintillating crystals as detection medium can provide metabolic images of the breast with significantly higher sensitivity and specificity with respect to standard whole body PET scanners. Over the past few years, crystal PEMs have dramatically increased their importance in the diagnosis and treatment of early stage breast cancer. Nevertheless, designs based on scintillators are characterized by an intrinsic deficiency of the depth of interaction (DOI) information from relatively thick crystals constraining the size of the smallest detectable tumor. This work shows how to overcome such intrinsic limitation by substituting scintillating crystals with pixelated CdTe detectors. The proposed novel design is developed within the Voxel Imaging PET (VIP) Pathfinder project and evaluated via Monte Carlo simulation. The volumetric spatial resolution of the VIP-PEM is expected to be up to 6 times better than standard commercial devices with a point spread function of 1 mm full width at half maximum (FWHM) in all directions. Pixelated CdTe detectors can also provide an energy resolution as low as 1.5% FWHM at 511 keV for a virtually pure signal with negligible contribution from scattered events. PMID:23750176

  1. Clinical evaluation of a high-resolution (2. 6-mm) positron emission tomography

    SciTech Connect

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

    1990-09-01

    The intrinsic resolution of the Donner 600-crystal positron emission tomograph (PET 600) is 2.6 mm full width at half maximum (FWHM) in-plane and 6 mm FWHM axially. More than 100 patients with glioma, radiation necrosis, Alzheimer disease, or epilepsy have been studied with this system. Approximately 1 million events are acquired in 15 minutes, starting 1 hour after injection of 10 mCi (370 MBq) of fluorine-18-fluorodeoxyglucose. Normal structures as small as the superior colliculi and the external capsule have been resolved. Improved separation of the cortical ribbon from adjacent white matter has allowed more accurate determination of cortical metabolic rate. In two of 15 patients undergoing evaluation for recurrent glioma, the PET 600 images showed tumor uptake that was not apparent on a lower-resolution study. A high-activity orbiting transmission source with electronic collimation allows accurate, short-duration transmission measurements to be made after radiopharmaceutical administration. The anatomic detail seen on the transmission images can be used for reproducible patient positioning with an accuracy of 1-2 mm perpendicular to the image plane. These findings demonstrate the practicality and clinical effectiveness of high-resolution positron emission tomography.

  2. 18F-AV-1451 positron emission tomography in Alzheimer's disease and progressive supranuclear palsy.

    PubMed

    Passamonti, Luca; Vázquez Rodríguez, Patricia; Hong, Young T; Allinson, Kieren S J; Williamson, David; Borchert, Robin J; Sami, Saber; Cope, Thomas E; Bevan-Jones, W Richard; Jones, P Simon; Arnold, Robert; Surendranathan, Ajenthan; Mak, Elijah; Su, Li; Fryer, Tim D; Aigbirhio, Franklin I; O'Brien, John T; Rowe, James B

    2017-03-01

    The ability to assess the distribution and extent of tau pathology in Alzheimer's disease and progressive supranuclear palsy in vivo would help to develop biomarkers for these tauopathies and clinical trials of disease-modifying therapies. New radioligands for positron emission tomography have generated considerable interest, and controversy, in their potential as tau biomarkers. We assessed the radiotracer 18F-AV-1451 with positron emission tomography imaging to compare the distribution and intensity of tau pathology in 15 patients with Alzheimer's pathology (including amyloid-positive mild cognitive impairment), 19 patients with progressive supranuclear palsy, and 13 age- and sex-matched controls. Regional analysis of variance and a support vector machine were used to compare and discriminate the clinical groups, respectively. We also examined the 18F-AV-1451 autoradiographic binding in post-mortem tissue from patients with Alzheimer's disease, progressive supranuclear palsy, and a control case to assess the 18F-AV-1451 binding specificity to Alzheimer's and non-Alzheimer's tau pathology. There was increased 18F-AV-1451 binding in multiple regions in living patients with Alzheimer's disease and progressive supranuclear palsy relative to controls [main effect of group, F(2,41) = 17.5, P < 0.0001; region of interest × group interaction, F(2,68) = 7.5, P < 0.00001]. More specifically, 18F-AV-1451 binding was significantly increased in patients with Alzheimer's disease, relative to patients with progressive supranuclear palsy and with control subjects, in the hippocampus and in occipital, parietal, temporal, and frontal cortices (t's > 2.2, P's < 0.04). Conversely, in patients with progressive supranuclear palsy, relative to patients with Alzheimer's disease, 18F-AV-1451 binding was elevated in the midbrain (t = 2.1, P < 0.04); while patients with progressive supranuclear palsy showed, relative to controls, increased 18F-AV-1451 uptake in the putamen, pallidum

  3. Routine positron emission tomography and positron emission tomography/computed tomography in melanoma staging with positive sentinel node biopsy is of limited benefit.

    PubMed

    Constantinidou, Anastasia; Hofman, Michael; O'Doherty, Michael; Acland, Katharine M; Healy, Ciaran; Harries, Mark

    2008-02-01

    Positron emission tomography (PET) is increasingly used for the staging and management of melanoma. The aim of this study was to evaluate the role of PET or PET/ computed tomography (CT) as a routine procedure in patients with positive sentinel node biopsy (SNB). Thirty patients with melanoma of Breslow thickness greater than 1 mm who had PET or PET/CT scans performed within 100 days after a positive SNB were reviewed retrospectively. Two patients (6%) had a positive PET scan, none of which were melanoma related. The first patient had a synchronous neuroendocrine thyroid tumour and the second patient had increased uptake in the chest wall, which proved to be old trauma. Lymph node dissection was positive in five cases (16%). With a median follow-up of 24 months, 21 patients remained disease free. In none of the 30 cases did the early PET scan after a positive SNB alter subsequent melanoma management. The role of PET scanning soon after a positive sentinel node biopsy seems to be of limited benefit. It is questionable whether any imaging is beneficial at this stage. The results of this review suggest that PET scanning might not be indicated for this group of patients.

  4. Positron emission tomography microdosing: a new concept with application in tracer and early clinical drug development.

    PubMed

    Bergström, Mats; Grahnén, Anders; Långström, Bengt

    2003-09-01

    The realisation that new chemical entities under development as drug candidates fail in three of four cases in clinical trials, together with increased costs and increased demands of reducing preclinical animal experiments, have promoted concepts for improvement of early screening procedures in humans. Positron emission tomography (PET) is a non-invasive imaging technology, which makes it possible to determine drug distribution and concentration in vivo in man with the drug labelled with a positron-emitting radionuclide that does not change the biochemical properties. Recently, developments in the field of rapid synthesis of organic compounds labelled with positron-emitting radionuclides have allowed a substantial number of new drug candidates to be labelled and potentially used as probes in PET studies. Together, these factors led to the logical conclusion that early PET studies, performed with very low drug doses-PET-microdosing-could be included in the drug development process as one means for selection or rejection of compounds based on performance in vivo in man. Another important option of PET, to evaluate drug interaction with a target, utilising a PET tracer specific for this target, necessitates a more rapid development of such PET methodology and validations in humans. Since only very low amounts of drugs are used in PET-microdosing studies, the safety requirements should be reduced relative to the safety requirements needed for therapeutic doses. In the following, a methodological scrutinising of the concept is presented. A complete pre-clinical package including limited toxicity assessment is proposed as a base for the regulatory framework of the PET-microdosing concept.

  5. Quantitative imaging of I-124 using positron emission tomography with applications to radioimmunodiagnosis and radioimmunotherapy

    SciTech Connect

    Pentlow, K.S.; Graham, M.C.; Lambrecht, R.M.; Cheung, N.K.; Larson, S.M. )

    1991-05-01

    Positron emission tomography (PET) is potentially useful for the quantitative imaging of radiolabeled antibodies, leading in turn to improved dosimetry in radioimmunotherapy. Iodine-124 is a positron-emitting nuclide with appropriate chemical properties and half-life (4.2 days) for such studies since the radiolabeling of antibodies with iodine is well understood and the half-life permits measurements over several days. Unfortunately, I-124 has a complex decay scheme with many high-energy gamma rays and a positron abundance of only 25%. It has therefore been largely ignored as a PET-imaging nuclide. However, measurements made with phantoms and animals under realistic conditions using a BGO-based PET scanner have shown that satisfactory imaging and quantitation can be achieved. Investigations of spatial resolution, the linearity of regional observed count rate versus activity in the presence of other activity, and the visualization and quantitation of activity in spheres with different surrounding background activities were carried out with phantoms up to 22 cm in diameter. Compared with F-18, spatial resolution was only slightly degraded (13.5 mm FWHM vs 12 mm FWHM) while linearity was the same over a 10:1 activity range (0.015 to 0.15 MBq/ml for I-124). The visualization and quantitation of spheres was also slightly degraded when using similar imaging times. Increasing the imaging time for I-124 reduced the difference. To verify that the technique would work in vivo, measurements were made of human neuroblastoma tumors in rats which had been injected with I-124 labeled 3F8 antibody. Although the number of samples was small, good agreement was achieved between image-based measurements and direct measurements of excised 4-g tumors. Thus quantitative imaging of I-124 labeled antibodies appears to be possible under realistic conditions.

  6. Positron emission tomography in the quantification of cellular and biochemical responses to intrapulmonary particulates

    SciTech Connect

    Jones, Hazel A. . E-mail: hazel.jones@imperial.ac.uk; Hamacher, Kurt; Clark, John C.; Schofield, John B.; Krausz, Thomas; Haslett, Christopher; Boobis, Alan R.

    2005-09-01

    Inhaled mineral dusts and fibres can cause chronic pulmonary inflammation, often leading to permanent scarring with loss of function, but the mechanisms involved remain obscure. There are currently no good methods for monitoring inflammatory processes in situ. Positron emission tomography (PET) of suitable intravenously injected radiolabelled markers provides non-invasive and repeatable methods of quantifying biochemical and cellular responses. We have developed animal models of fibrotic and non-fibrotic pulmonary response to particulate instillation and characterised these by histology. Different components of the inflammatory response have been investigated by PET: (1) [{sup 18}F]-labelled fluoro-deoxyglucose, a positron emitting glucose analogue, accumulates in cells in proportion to their glucose uptake; ex vivo microautoradiography indicates that neutrophils are the cells responsible for an increased signal during pulmonary inflammation; a persistently high uptake is associated with lung scarring. (2) The radioligand [{sup 11}C]-R-PK11195 binds to benzodiazepine-like receptors abundant in macrophages; following particulate instillation, the [{sup 11}C]-R-PK11195 PET signal tracks with lung macrophage accumulation and also localises to regions consistent with macrophage clearance; poor macrophage clearance is associated with fibrosis. (3) [{sup 18}F]-fluoroproline is likely a substrate for extracellular matrix production, especially proline-rich collagen; during active scarring, the rate of lung uptake of fluoroproline is elevated. Localisation of radioactivity in the lung has been validated ex vivo by microautoradiography of tritium analogues of each of the positron emitting tracers. The use of PET to monitor different inflammatory processes by repeated scanning of the same animal or individual is helping to identify key events in the fibrotic process.

  7. Studies of discrete symmetries in a purely leptonic system using the Jagiellonian Positron Emission Tomograph

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

    Discrete symmetries such as parity (P), charge-conjugation (C) and time reversal (T) are of fundamental importance in physics and cosmology. Breaking of charge conjugation symmetry (C) and its combination with parity (CP) constitute necessary conditions for the existence of the asymmetry between matter and antimatter in the observed Universe. The presently known sources of discrete symmetries violations can account for only a tiny fraction of the excess of matter over antimatter. So far CP and T symmetries violations were observed only for systems involving quarks and they were never reported for the purely leptonic objects. In this article we describe briefly an experimental proposal for the test of discrete symmetries in the decays of positronium atom which is made exclusively of leptons. The experiments are conducted by means of the Jagiellonian Positron Emission Tomograph (J-PET) which is constructed from strips of plastic scintillators enabling registration of photons from the positronium annihilation. J-PET tomograph together with the positronium target system enable to measure expectation values for the discrete symmetries odd operators constructed from (i) spin vector of the ortho-positronium atom, (ii) momentum vectors of photons originating from the decay of positronium, and (iii) linear polarization direction of annihilation photons. Linearly polarized positronium will be produced in the highly porous aerogel or polymer targets, exploiting longitudinally polarized positrons emitted by the sodium 22Na isotope. Information about the polarization vector of orthopositronium will be available on the event by event basis and will be reconstructed from the known position of the positron source and the reconstructed position of the orthopositronium annihilation. In 2016 the first tests and calibration runs are planned, and the data collection with high statistics will commence in the year 2017.

  8. Randomized Trial of Neuroprotective Effects of Erythropoietin in Patients Receiving Adjuvant Chemotherapy for Breast Cancer: Positron Emission Tomography and Neuropsychological Study

    DTIC Science & Technology

    2008-09-01

    Effects of Erythropoietin in Patients Receiving Adjuvant Chemotherapy for Breast Cancer : Positron Emission Tomography and Neuropsychological Study...Neuroprotective Effects of Erythropoietin in Patients 5a. CONTRACT NUMBER Receiving Adjuvant Chemotherapy for Breast Cancer : Positron Emission Tomography...11 Introduction In the United States approximately 60-80% of patients diagnosed with breast cancer will receive

  9. Positron emission mammography (PEM): A promising technique for detecting breast cancer

    SciTech Connect

    Thompson, C.J.; Murthy, K.; Picard, Y.; Mako, R.; Weinberg, I.N.

    1995-08-01

    The authors are developing a high specificity technique for detecting the increased metabolic rate of breast tumors. The glucose analog FDG is known to concentrate in breast tumors rendering them easily detectable in conventional PET scans. Since PET is a relatively expensive imaging technique it has not been used routinely in the detection of breast cancer. Positron emission mammography (PEM) will provide a highly efficient, high spatial resolution, and low cost positron imaging system whose metabolic images are co-registered with conventional mammography. Coincidences between two BGO blocks cut into 2 x 2 mm squares coupled to two 7.5 cm square imaging PMTs are detected and back-projected to form real-time multiple plane images. The design is about 20 times more sensitive than a conventional multi-slice PET body scanner, so much less radio-pharmaceutical can be used, reducing the patient dose and cost per scan. Prototype detectors have been made and extensive measurements done. The device is expected to have an in-plane spatial resolution about 2 mm FWHM. Besides the application as a secondary screening tool the device may be beneficial in measuring a tumor`s response to radio-therapy or chemo-therapy, as well as aiding the surgeon in optimizing the removal of malignant tissue.

  10. Positron emission tomography (PET): expanding the horizons of oncology drug development.

    PubMed

    Hammond, Lisa A; Denis, Louis; Salman, Umber; Jerabek, Paul; Thomas, Charles R; Kuhn, John G

    2003-08-01

    Positron emission tomography (PET) allows three-dimensional quantitative determination of the distribution of radioactivity permitting measurement of physiological, biochemical, and pharmacological functions at the molecular level. Until recently, no method existed to directly and noninvasively assess transport and metabolism of neoplastic agents as a function of time in various organs as well as in the tumor. Standard preclinical evaluation of potential anticancer agents entails radiolabeling the agent, usually with tritium or 14C, sacrifice experiments, and high-performance liquid chromatography (HPLC) analysis to determine the biodistribution and metabolism in animals. Radiolabeling agents with positron-emitting radionuclides allows the same information to be obtained as well as in vivo pharmacokinetic (PK) data by animal tissue and plasma sampling in combination with PET scanning. In phase I/II human studies, classic PK measurements can be coupled with imaging measurements to define an optimal dosing schedule and help formulate the design of phase III studies that are essential for drug licensure [1]. Many of the novel agents currently in development are cytostatic rather than cytotoxic and therefore, the traditional standard endpoints in phase I and II studies may no longer be relevant. The use of a specialized imaging modality that allows PK and pharmacodynamic (PD) evaluation of a drug of interest has been proposed to permit rapid and sensitive assessment of the biological effects of novel anticancer agents. The progress to date and the challenges of incorporating PET technology into oncology drug development from the preclinical to clinical setting are reviewed in this article.

  11. Cosmic ray electrons, positrons and the synchrotron emission of the Galaxy: consistent analysis and implications

    SciTech Connect

    Bernardo, Giuseppe Di; Evoli, Carmelo; Gaggero, Daniele; Grasso, Dario; Maccione, Luca E-mail: carmelo.evoli@desy.de E-mail: dario.grasso@pi.infn.it

    2013-03-01

    A multichannel analysis of cosmic ray electron and positron spectra and of the diffuse synchrotron emission of the Galaxy is performed by using the DRAGON code. This study is aimed at probing the interstellar electron source spectrum down to E ∼< 1GeV and at constraining several propagation parameters. We find that above 4GeV the e{sup −} source spectrum is compatible with a power-law of index ∼ 2.5. Below 4GeV instead it must be significantly suppressed and the total lepton spectrum is dominated by secondary particles. The positron spectrum and fraction measured below a few GeV are consistently reproduced only within low reacceleration models. We also constrain the scale-height z{sub t} of the cosmic-ray distribution using three independent (and, in two cases, original) arguments, showing that values of z{sub t} ∼< 2kpc are excluded. This result may have strong implications for particle dark matter searches.

  12. Measurement of human cerebral blood flow with (15O)butanol and positron emission tomography

    SciTech Connect

    Berridge, M.S.; Adler, L.P.; Nelson, A.D.; Cassidy, E.H.; Muzic, R.F.; Bednarczyk, E.M.; Miraldi, F. )

    1991-09-01

    Although H2(15)O is widely used for CBF measurement by positron tomography, it underestimates CBF, especially at elevated flow rates. Several tracers, including butanol, overcome this problem, but the short half-life of 15O provides advantages that cause water to remain the tracer of choice. The authors report the first use and evaluation of 15O-labeled butanol for CBF measurement. Flow measurements made in a similar fashion with water and butanol at 10-min intervals were compared in normal volunteers under resting and hypercapnic conditions. Regional analysis showed good agreement between the tracers at low flows, and significant underestimation of flow by water relative to butanol in regions of elevated flow. The observed relationship between the tracers and the curve-fitted permeability-surface area product for water (133 ml.100 g-1.min-1) follow the known relationship between water and true flow. These observations indicate that (15O)-butanol provided accurate measurements of human regional CBF under conditions of elevated perfusion. They conclude that butanol is a convenient and accurate method for routine CBF determination by positron emission tomography.

  13. Pretargeted Positron Emission Tomography Imaging That Employs Supramolecular Nanoparticles with in Vivo Bioorthogonal Chemistry.

    PubMed

    Hou, Shuang; Choi, Jin-Sil; Garcia, Mitch Andre; Xing, Yan; Chen, Kuan-Ju; Chen, Yi-Ming; Jiang, Ziyue K; Ro, Tracy; Wu, Lily; Stout, David B; Tomlinson, James S; Wang, Hao; Chen, Kai; Tseng, Hsian-Rong; Lin, Wei-Yu

    2016-01-26

    A pretargeted oncologic positron emission tomography (PET) imaging that leverages the power of supramolecular nanoparticles with in vivo bioorthogonal chemistry was demonstrated for the clinically relevant problem of tumor imaging. The advantages of this approach are that (i) the pharmacokinetics (PKs) of tumor-targeting and imaging agents can be independently altered via chemical alteration to achieve the desired in vivo performance and (ii) the interplay between the two PKs and other controllable variables confers a second layer of control toward improved PET imaging. In brief, we utilized supramolecular chemistry to synthesize tumor-targeting nanoparticles containing transcyclooctene (TCO, a bioorthogonal reactive motif), called TCO⊂SNPs. After the intravenous injection and subsequent concentration of the TCO⊂SNPs in the tumors of living mice, a small molecule containing both the complementary bioorthogonal motif (tetrazine, Tz) and a positron-emitting radioisotope ((64)Cu) was injected to react selectively and irreversibly to TCO. High-contrast PET imaging of the tumor mass was accomplished after the rapid clearance of the unreacted (64)Cu-Tz probe. Our nanoparticle approach encompasses a wider gamut of tumor types due to the use of EPR effects, which is a universal phenomenon for most solid tumors.

  14. 11C=O Bonds Made Easily for Positron Emission Tomography Radiopharmaceuticals

    PubMed Central

    Rotstein, Benjamin H.; Liang, Steven H.; Placzek, Michael S.; Hooker, Jacob M.; Gee, Antony D.; Dollé, Frédéric; Wilson, Alan A.; Vasdev, Neil

    2016-01-01

    The positron-emitting radionuclide carbon-11 (11C, t1/2 = 20.3 minutes) possesses the unique potential for radiolabeling of any biological, naturally occurring, or synthetic organic molecule for in vivo positron emission tomography (PET) imaging. Carbon-11 is most often incorporated into small molecules by methylation of alcohol, thiol, amine or carboxylic acid precursors using [11C]methyl iodide or [11C]methyl triflate (generated from [11C]CO2). Consequently, small molecules that lack an easily substituted 11C-methyl group are often considered to have non-obvious strategies for radiolabeling and require a more customized approach. [11C]Carbon dioxide, [11C]carbon monoxide, [11C]cyanide, and [11C]phosgene represent alternative carbon-11 reactants to enable 11C-carbonylation. Methodologies developed for preparation of 11C-carbonyl groups have had a tremendous impact on the development of novel PET radiopharmaceuticals and provided key tools for clinical research. 11C-Carbonyl radiopharmaceuticals based on labeled carboxylic acids, amides, carbamates, and ureas now account for a substantial number of important imaging agents that have seen translation to higher species and clinical research of previously inaccessible targets, which is a testament to the creativity, utility, and practicality of the underlying radiochemistry. PMID:27276357

  15. Evaluation of positron emission tomography as a method to visualize subsurface microbial processes

    SciTech Connect

    Kinsella K.; Schlyer D.; Kinsella, K.; Schlyer, D.J.; Fowler, J.S.; Martinez, R.J.; Sobecky, P.A.

    2012-01-18

    Positron emission tomography (PET) provides spatiotemporal monitoring in a nondestructive manner and has higher sensitivity and resolution relative to other tomographic methods. Therefore, this technology was evaluated for its application to monitor in situ subsurface bacterial activity. To date, however, it has not been used to monitor or image soil microbial processes. In this study, PET imaging was applied as a 'proof-of-principle' method to assess the feasibility of visualizing a radiotracer labeled subsurface bacterial strain (Rahnella sp. Y9602), previously isolated from uranium contaminated soils and shown to promote uranium phosphate precipitation. Soil columns packed with acid-purified simulated mineral soils were seeded with 2-deoxy-2-[{sup 18}F]fluoro-d-glucose ({sup 18}FDG) labeled Rahnella sp. Y9602. The applicability of [{sup 18}F]fluoride ion as a tracer for measuring hydraulic conductivity and {sup 18}FDG as a tracer to identify subsurface metabolically active bacteria was successful in our soil column studies. Our findings indicate that positron-emitting isotopes can be utilized for studies aimed at elucidating subsurface microbiology and geochemical processes important in contaminant remediation.

  16. Development of a treatment planning system for BNCT based on positron emission tomography data: preliminary results

    NASA Astrophysics Data System (ADS)

    Cerullo, N.; Daquino, G. G.; Muzi, L.; Esposito, J.

    2004-01-01

    Present standard treatment planning (TP) for glioblastoma multiforme (GBM - a kind of brain tumor), used in all boron neutron capture therapy (BNCT) trials, requires the construction (based on CT and/or MRI images) of a 3D model of the patient head, in which several regions, corresponding to different anatomical structures, are identified. The model is then employed by a computer code to simulate radiation transport in human tissues. The assumption is always made that considering a single value of boron concentration for each specific region will not lead to significant errors in dose computation. The concentration values are estimated "indirectly", on the basis of previous experience and blood sample analysis. This paper describes an original approach, with the introduction of data on the in vivo boron distribution, acquired by a positron emission tomography (PET) scan after labeling the BPA (borono-phenylalanine) with the positron emitter 18F. The feasibility of this approach was first tested with good results using the code CARONTE. Now a complete TPS is under development. The main features of the first version of this code are described and the results of a preliminary study are presented. Significant differences in dose computation arise when the two different approaches ("standard" and "PET-based") are applied to the TP of the same GBM case.

  17. A positron emission particle tracking investigation of the flow regimes in tumbling mills

    NASA Astrophysics Data System (ADS)

    Govender, I.; Pathmathas, T.

    2017-01-01

    Using positron emission particle tracking (PEPT) data we recover key granular rheology ingredients (velocity, shear rate, volume concentration, bed depth) for developing, testing and calibrating granular flow models. In this regard, 5 mm glass beads were rotated within a 476 mm diameter mill fitted with angled lifter bars along the inner azimuthal walls and operated in batch mode across a range of drum rotation speeds that span cascading and cataracting Froude regimes. After averaging the PEPT outputs into representative volume elements, subsequent continuum analysis of the flowing layer revealed a rich coexistence of flow regimes: a quasi-static layer dominated by frictional interactions, a dense, liquid-like layer that is stressed by frictional and collisional interactions, and an inertial layer that interacts mainly through collisions. Combining the inertial number with an empirically formulated dilatancy law and the measured granular rheological ingredients then facilitated the recovery of the total depth-dependent pressure of the free surface layer.

  18. An 8×8 Row-Column Summing Readout Electronics for Preclinical Positron Emission Tomography Scanners

    PubMed Central

    Shih, Y. C.; Sun, F. W.; MacDonald, L. R.; Otis, B. P.; Miyaoka, R. S.; McDougald, W.; Lewellen, T. K.

    2010-01-01

    This work presents a row/column summing readout electronics for an 8×8 silicon photomultiplier array. The summation circuit greatly reduces the number of electronic channels, which is desirable for pursuing higher resolution positron emission tomography scanners. By using a degenerated common source topology in the summation circuit, more fan-in is possible and therefore a greater reduction in the number of electronic channels can be achieved. The timing signal is retrieved from a common anode, which allows the use of a single fast-sampling analog to digital converter (ADC) for the timing channel and slower, lower power ADCs for the 64 spatial channels. Preliminary results of one row summation of the 8×8 readout electronics exhibited FWHM energy resolution of 17.8% and 18.3% with and without multiplexing, respectively. The measured timing resolution is 2.9ns FWHM. PMID:20729983

  19. Regional cerebral glucose metabolic rate in human sleep assessed by positron emission tomography

    SciTech Connect

    Buchsbaum, M.S.; Wu, J.; Hazlett, E.; Sicotte, N.; Bunney, W.E. Jr. ); Gillin, J.C. )

    1989-01-01

    The cerebral metabolic rate of glucose was measured during nighttime sleep in 36 normal volunteers using positron emission tomography and fluorine-18-labeled 2-deoxyglucose (FDG). In comparison to waking controls, subjects given FDG during non-rapid eye movement (NREM) sleep showed about a 23% reduction in metabolic rate across the entire brain. This decrease was greater for the frontal than temporal or occipital lobes, and greater for basal ganglia and thalamus than cortex. Subjects in rapid eye movement (REM) sleep tended to have higher cortical metabolic rates than walking subjects. The cingulate gyrus was the only cortical structure to show a significant increase in glucose metabolic rate in REM sleep in comparison to waking. The basal ganglia were relatively more active on the right in REM sleep and symmetrical in NREM sleep.

  20. Myelin imaging with C-11 labeled diphenylmethanol and positron emission tomography

    SciTech Connect

    Herscovitch, P.; Dischino, D.D.; Kilbourn, M.R.; Welch, M.J.; Raichle, M.E.

    1985-05-01

    The authors have recently studied several C-11-labeled radiopharmaceuticals for their suitability as myelin imaging agents with positron emission tomography (PET). C-11 diphenylmethanol (DPM) was selected on the basis of its in vivo metabolic stability and high extraction and lipophilicity. PET studies were performed in three normal subjects and in one patient with multiple sclerosis (MS). Myelin distribution was imaged following the bolus intravenous administration of 25-30 mCi of C-11 DPM. Sequential scans were obtained after radiotracer administration to measure the DPM distribution as a function of time. In addition, regional cerebral blood flow was measured after the bolus intravenous injection of 0-15 water. A tomographic slice through the centrum semiovale was used to obtain regional data for gray matter (GM) and white matter (WM).

  1. The Use and Misuse of Positron Emission Tomography in Lung Cancer Evaluation

    PubMed Central

    Chang, Ching-Fei; Rashtian, Afshin; Gould, Michael K.

    2011-01-01

    Synopsis Positron emission tomography (PET) has been studied for a variety of indications in patients with known or suspected non-small cell lung cancer (NSCLC). In this review, we discuss the potential benefits and limitations of PET for characterizing lung nodules, staging the mediastinum, identifying occult distant metastasis, determining prognosis and treatment response, guiding plans for radiation therapy, restaging during and after treatment, and selecting targets for tissue sampling. (Table 1) Evidence from randomized, controlled trials supports the use of PET for initial staging in NSCLC, while lower quality evidence from studies of diagnostic accuracy and modeling studies supports the use of PET for characterizing lung nodules. For most other indications in NSCLC, additional studies are required to clarify the role of PET and determine who is most likely to benefit. PMID:22054883

  2. Extramedullary Plasmacytoma of the Gallbladder Detected on Fluorine 18-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

    PubMed Central

    Fakhri, Asif Ali; Rodrigue, Paul David; Fakhri, Amena Fatima

    2016-01-01

    Extramedullary plasmacytoma is rare in patients with diagnosed multiple myeloma. Soft tissue plasmacytoma of the gallbladder is particularly uncommon and has been described in only a handful of cases. Diagnosis of gallbladder plasmacytoma with fluorine 18-fluorodeoxyglucose (F18-FDG) positron emission tomography/computed tomography (PET/CT) has not previously been reported. We present a 65-year-old female with a history of multiple myeloma who underwent a restaging F18-FDG-PET/CT which showed a focal area of hypermetabolic activity, corresponding to a nodular lesion within the posterior gallbladder wall. The patient underwent successful cholecystectomy, with surgical pathology revealing gallbladder plasmacytoma. A follow-up scan was negative for active malignancy. This is a novel case of gallbladder plasmacytoma diagnosed on whole-body F18-FDG PET/CT – thus demonstrating the clinical value of this imaging modality in staging, restaging, and surveillance for patients with multiple myeloma. PMID:27761300

  3. Positron emission tomography demonstrated localized luxury perfusion in subacute sclerosing panencephalitis.

    PubMed

    Yoshikawa, H; Fueki, N; Yoneyama, H; Ogawa, M; Sakuragawa, N

    1990-10-01

    Positron emission tomography (PET) was performed on two patients in different stages of subacute sclerosing panencephalitis (SSPE) and compared with the concurrent computed tomography (CT) findings and clinical status. Case 1, which was in stage II, showed luxury perfusion in the anterior half of the cerebrum and decreases of cerebral blood flow and oxygen metabolism in the right frontal watershed zone, where CT showed low density. Case 2, which was in stage III, showed marked decreases of cerebral blood flow and cerebral metabolic rate of oxygen in all regions except the occipital region. The present PET study demonstrated that SSPE showed inflammatory-destructive progression and rostral-caudal progression. Further, it was suspected that low density on CT scan, especially in the watershed zone, resulted partly from disturbances in cerebral circulation.

  4. Magnetic field calculation for a 10 MeV positron emission tomography cyclotron.

    PubMed

    Chen, Dezhi; Chen, Zihao; Liu, Kaifeng; Yang, Jun; Li, Dong; Qin, Bin; Xiong, Yongqian

    2013-05-01

    The magnetic field calculation and correction for a 10 MeV positron emission tomography cyclotron is presented. 3D TOSCA analysis results are compared with the measured data, and the calculation error is used to calibrate the B-H curve to obtain a very precise finite element method estimator, which is used to predict the correction of the magnet pole for achieving the isochronous field. The isochronous field error is approximated with the effects of a set of standard patches. On the assumption that the effect of each small patch is proportional to its surface, the correction of the magnet pole is found by solving a system of equations using the least square scheme. The magnet shimming is performed and the measured magnetic field is found in good agreement with the prediction, with an error less than 2 G.

  5. Regional brain glucose metabolism in chronic schizophrenia. A positron emission transaxial tomographic study

    SciTech Connect

    Farkas, T.; Wolf, A.P.; Jaeger, J.; Brodie, J.D.; Christman, D.R.; Fowler, J.S.

    1984-03-01

    Thirteen diagnosed schizophrenics and 11 normal controls were studied with a method using the PETT III positron emission tomograph (PET) and fluorodeoxyglucose labeled with fluorine 18. Each subject also had a computed tomographic (CT) scan. For each subject, two brain levels, one through the basal ganglia and one through the semioval center, were analyzed for the mean regional metabolic glucose rate. Specifically, relationships between frontal and posterior regions were evaluated. The CT scans of matching levels were superimposed on the functional PET images to provide anatomic criteria for region of interest selection. While no whole-slice metabolic differences were apparent between groups, schizophrenics had significantly lower activity in the frontal lobes, relative to posterior regions. The medicated and drug-free groups did not differ from one another in these regards. Trait v state dependency of the phenomenon was analyzed, and several technological limitations were considered.

  6. Positron emission tomography in minor ischemic stroke using oxygen-15 steady-state technique

    SciTech Connect

    Pozzilli, C.; Itoh, M.; Matsuzawa, T.; Fukuda, H.; Abe, Y.; Sato, T.; Takeda, S.; Ido, T.

    1987-04-01

    A study with positron emission tomography (PET) was performed on 10 patients with ischemic stroke and mild disability. The patients underwent cerebral angiography, x-ray computed tomography (CT) scan and regional cerebral measurements of CBF, CMRO2, oxygen extraction ratio (OER), and cerebral blood volume (CBV). Only minor arterial involvement was detected by angiography. In all patients, PET images of functional defects were more extensive than the corresponding CT hypodensity, and there were statistically significant reductions in CBF, CMRO2, and CBF/CBV ratio as compared with control subjects. Half of the regions analyzed in the affected hemisphere demonstrated a disruption of the normal coupling between CBF and CMRO2 as reflected by OER values significantly higher or lower than those of the corresponding region of the contralateral hemisphere. The pathophysiological pattern of high OER combined with a reduction in CBF proportionally greater than the reduction in CMRO2 was particularly indicative of regional chronic hemodynamic compromise in these patients.

  7. 18F-FDG positron emission tomography in oncology: main indications.

    PubMed

    Vercher-Conejero, J L; Gámez Cenzano, C

    2016-01-01

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

  8. Refraction-compensated motion tracking of unrestrained small animals in positron emission tomography.

    PubMed

    Kyme, Andre; Meikle, Steven; Baldock, Clive; Fulton, Roger

    2012-08-01

    Motion-compensated radiotracer imaging of fully conscious rodents represents an important paradigm shift for preclinical investigations. In such studies, if motion tracking is performed through a transparent enclosure containing the awake animal, light refraction at the interface will introduce errors in stereo pose estimation. We have performed a thorough investigation of how this impacts the accuracy of pose estimates and the resulting motion correction, and developed an efficient method to predict and correct for refraction-based error. The refraction model underlying this study was validated using a state-of-the-art motion tracking system. Refraction-based error was shown to be dependent on tracking marker size, working distance, and interface thickness and tilt. Correcting for refraction error improved the spatial resolution and quantitative accuracy of motion-corrected positron emission tomography images. Since the methods are general, they may also be useful in other contexts where data are corrupted by refraction effects.

  9. Positron emission tomography suggests that the rate of progression of idiopathic parkinsonism is slow

    SciTech Connect

    Bhatt, M.H.; Snow, B.J.; Martin, W.R.; Pate, B.D.; Ruth, T.J.; Calne, D.B. )

    1991-06-01

    The authors performed sequential positron emission tomography scans with 6-(18F)fluoro-L-dopa in 9 patients with idiopathic parkinsonism and 7 age-matched normal control subjects to compare changes in the nigrostriatal dopaminergic pathway over time. The mean interval between the scans was 3.3 years for the group with idiopathic parkinsonism and 3.9 years for the control subjects. The scans were analyzed by calculating the ratio of striatal to background radioactivity. Both groups showed statistically significant reductions of striatal uptake over the interval. The rate of decrease was almost identical in each group (p = 0.6). They infer that the usual rate of loss of integrity of the dopaminergic nigrostriatal pathway in patients with idiopathic parkinsonism is slow and the rate of change between the two groups was comparable.

  10. Imaging amyloid in Parkinson's disease dementia and dementia with Lewy bodies with positron emission tomography.

    PubMed

    Brooks, David J

    2009-01-01

    Although Parkinson's disease with later dementia (PDD) and dementia with Lewy bodies (DLB) are pathologically characterized by the presence of intraneuronal Lewy inclusion bodies, amyloid deposition is also associated to varying degrees with both these disorders. Fibrillar amyloid load can now be quantitated in vivo with positron emission tomography (PET) using imaging biomarkers. Here the reported findings of 11C-PIB PET studies concerning the amyloid load associated with PD and its influence on dementia are reviewed. It is concluded that the presence of amyloid acts to accelerate the dementia process in Lewy body disorders, though has little influence on its nature. Anti-amyloid strategies could be a relevant approach for slowing dementia in a number of DLB and PDD cases.

  11. The impact of positron emission tomography imaging on the clinical management of patients with epilepsy.

    PubMed

    Juhász, Csaba

    2012-06-01

    Clinical positron emission tomography (PET) imaging of human epilepsy has a 30-year history, but it is still searching for its exact role among rapidly advancing neuroimaging techniques. The vast majority of epilepsy PET studies used this technique to improve detection of epileptic foci for surgical resection. Here, we review the main trends emerging from three decades of PET research in epilepsy, with a particular emphasis on how PET imaging has impacted on the clinical management of patients with intractable epilepsy. While reviewing the latest studies, we also present an argument for a changing role of PET and molecular imaging in the future, with an increasing focus on epileptogenesis and newly discovered molecular mechanisms of epilepsy. These new applications will be facilitated by technological advances, such as the use of integrated PET/MRI systems and utilization of novel radiotracers, which may also enhance phenotype-genotype correlations and assist rational, individualized treatment strategies.

  12. Receptor-specific positron emission tomography radiopharmaceuticals: /sup 75/Br-labeled butyrophenone neuroleptics

    SciTech Connect

    Moerlein, S.M.; Stoecklin, G.; Weinhard, K.; Pawlik, G.; Heiss, W.D.

    1985-11-01

    Cerebral dopaminergic D/sub 2/ receptors are involved in several common disease states, such as schizophrenia, Parkinson's disease, and Huntington's chorea. The use of radiolabeled D/sub 2/ receptor-binding ligands with positron emission tomography (PET) to noninvasively quantitate D/sub 2/ receptor densities thus has potential application in medicine. Butyrophenone neuroleptics have a high in vitro and in vivo binding affinity for cerebral D/sub 2/ receptors, and due to the useful chemical and nuclear decay properties of /sup 74/Br (76% ..beta../sup +/, half-life = 1.6 h), the authors have evaluated radiobrominated bromospiperone (BSP), brombenperidol (BBP), and bromperidol (BP) as radiopharmaceuticals for use with PET.

  13. Caffeine and human cerebral blood flow: A positron emission tomography study

    SciTech Connect

    Cameron, O.G.; Modell, J.G.; Hariharan, M. )

    1990-01-01

    Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased p{sub a}CO{sub 2} and increased systolic blood pressure significantly; the change in p{sub a}CO{sub 2} did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety were also observed.

  14. Nicotine Blocks Brain Estrogen Synthase (Aromatase): In Vivo Positron Emission Tomography Studies in Female Baboons

    SciTech Connect

    Biegon, A.; Biegon, A.; Kim, S.-W.; Logan, J.; Hooker, J.M.; Muench, L.; Fowler, J.S.

    2010-01-12

    Cigarette smoking and nicotine have complex effects on human physiology and behavior, including some effects similar to those elicited by inhibition of aromatase, the last enzyme in estrogen biosynthesis. We report the first in vivo primate study to determine whether there is a direct effect of nicotine administration on brain aromatase. Brain aromatase availability was examined with positron emission tomography and the selective aromatase inhibitor [{sup 11}C]vorozole in six baboons before and after exposure to IV nicotine at .015 and .03 mg/kg. Nicotine administration produced significant, dose-dependent reductions in [{sup 11}C]vorozole binding. The amygdala and preoptic area showed the largest reductions. Plasma levels of nicotine and its major metabolite cotinine were similar to those found in cigarette smokers. Nicotine interacts in vivo with primate brain aromatase in regions involved in mood, aggression, and sexual behavior.

  15. Clinical Utility of Positron Emission Tomography Magnetic Resonance Imaging (PET-MRI) in Gastrointestinal Cancers.

    PubMed

    Matthews, Robert; Choi, Minsig

    2016-09-09

    Anatomic imaging utilizing both CT (computed tomography) and MRI (magnetic resonance imaging) limits the assessment of cancer metastases in lymph nodes and distant organs while functional imaging like PET (positron emission tomography) scan has its limitation in spatial resolution capacity. Hybrid imaging utilizing PET-CT and PET-MRI are novel imaging modalities that are changing the current landscape in cancer diagnosis, staging, and treatment response. MRI has shown to have higher sensitivity in soft tissue, head and neck pathology, and pelvic disease, as well as, detecting small metastases in the liver and bone compared to CT. Combining MRI with PET allows for detection of metastases that may have been missed with current imaging modalities. In this review, we will examine the clinical utility of FDG PET-MRI in the diagnosis and staging of gastrointestinal cancers with focus on esophageal, stomach, colorectal, and pancreatic cancers. We will also explore its role in treatment response and future directions associated with it.

  16. Parametric imaging via kinetics-induced filter for dynamic positron emission tomography.

    PubMed

    Bian, Zhaoying; Huang, Jing; Lu, Lijun; Ma, Jianhua; Zeng, Dong; Feng, Qianjin; Chen, Wufan

    2013-01-01

    Due to the noisy measurement of the voxel-wise time activity curve (TAC), parametric imaging for dynamic positron emission tomography (PET) is a challenging task. To address this problem, some spatial filters, such as Gaussian filter, bilateral filter, wavelet-based filter, and so on, are often performed to reduce the noise of each frame. However, these filters usually just consider local properties of each frame without exploring the kinetic information. In this paper, aiming to improve the quantitative accuracy of parametric imaging, we present a kinetics-induced filter to lower the noise of dynamic PET images by incorporating the kinetic information. The present kinetics-induced filter is designed via the similarity between voxel-wise TACs under the framework of bilateral filter. Experimental results with a simulation study demonstrate that the present kinetics-induced filter can achieve noticeable gains than other existing methods for parametric images in terms of quantitative accuracy measures.

  17. [Fluorodeoxyglucose and bronchopulmonary cancer. Initial French results with positron emission tomography].

    PubMed

    Vaylet, F; Foehrenbach, H; De Dreuille, O; Maszelin, P; Merlet, P; Bendriem, B; L'Her, P; Syrota, A; Gaillard, J F

    1998-09-01

    Despite recent advances, the contribution of medical imaging techniques is limited, particularly in terms of tissue characterization, in the diagnosis of pulmonary nodules and search for extension of bronchogenic cancer. The metabolic properties of the glucose analog deoxyglucose labeled with 18F1 would allow metabolic imaging. Positron emission tomography (PET) provides clinicians with quality images with an interesting sensitivity. We report the results of a feasibility study conducted in our first 17 patients. We observed 14 true positives, 1 true negative and 1 false positive and 1 false negative in patients with a malignant primary lesion. We analyzed the causes of error. Ten disseminated localizations were identified. Possible developments in terms of therapeutic strategy are discussed. The agreement between our findings and data reported in the literature prompted us to develop a study protocol using 18-fluorodeoxyglucose PET in patients with bronchogenic cancer.

  18. Combined positron emission tomography and computed tomography to visualize and quantify fluid flow in sedimentary rocks

    NASA Astrophysics Data System (ADS)

    Fernø, M. A.; Gauteplass, J.; Hauge, L. P.; Abell, G. E.; Adamsen, T. C. H.; Graue, A.

    2015-09-01

    Here we show for the first time the combined positron emission tomography (PET) and computed tomography (CT) imaging of flow processes within porous rocks to quantify the development in local fluid saturations. The coupling between local rock structure and displacement fronts is demonstrated in exploratory experiments using this novel approach. We also compare quantification of 3-D temporal and spatial water saturations in two similar CO2 storage tests in sandstone imaged separately with PET and CT. The applicability of each visualization technique is evaluated for a range of displacement processes, and the favorable implementation of combining PET/CT for laboratory core analysis is discussed. We learn that the signal-to-noise ratio (SNR) is over an order of magnitude higher for PET compared with CT for the studied processes.

  19. Hemiballismus: Study of a case using positron emission tomography with 18fluoro-2-deoxyglucose

    SciTech Connect

    Dubinsky, R.M.; Greenberg, M.; Di Chiro, G.; Baker, M.; Hallett, M. )

    1989-01-01

    A 64-year-old man had right-sided persistent hemiballismus. Cerebral computed tomography (CT) and 0.5-T magnetic resonance imaging (MRI) showed no abnormalities, but 1.5-T MRI showed decreased signal intensity of the putamina, greater on the left than on the right. The subthalamic area was normal on CT and MRI. Positron emission tomography with 18fluoro2-deoxyglucose showed marked hypometabolism of the left putamen (60% of the right) and hypermetabolism of the left parietal lobe (138% of the right). The decreased metabolism of the left putamen may indicate a reduction in neuronal firing. The pathophysiology of the hemiballismus in this case may be loss of tonic inhibition of the lateral globus pallidus from the putamen, leading in turn to greater inhibition of the subthalamic nucleus, less excitation of the medial globus pallidus, and less inhibition of the thalamus and motor cortex, and thus allowing expression of the ballistic movements.

  20. Current status of positron emission tomography radiotracers for serotonin receptors in humans.

    PubMed

    Zimmer, Luc; Le Bars, Didier

    2013-01-01

    Serotonin (5-HT) neurotransmission plays a key modulatory role in the brain. This system is critical for pathophysiological processes and many drug treatments for brain disorders interact with its 14 subtypes of receptors. Positron emission tomography (PET) is a unique tool for the study of the living brain in translational studies from animal models to patients in neurology or psychiatry. This short review is intended to cover the current status of PET radioligands used for imaging human brain 5-HT receptors. Here, we describe the available PET radioligands for the 5-HT1A , 5-HT1B , 5-HT2A , 5-HT4 and 5-HT6 receptors. Finally, we highlight the future challenges for a functional PET imaging of serotonin receptors, including the research towards specific PET radiotracers for yet unexplored serotonin receptors, the need of radiotracers for endogenous serotonin level measurement and the contribution of agonist radiotracers for functional imaging of 5-HT neurotransmission.

  1. Hypoxia imaging using Positron Emission Tomography in non-small cell lung cancer: implications for radiotherapy.

    PubMed

    Bollineni, Vikram Rao; Wiegman, Erwin M; Pruim, Jan; Groen, Harry J M; Langendijk, Johannes A

    2012-12-01

    Tumour hypoxia is an important contributor to radioresistance. Thus, increasing the radiation dose to hypoxic areas may result in improved locoregional tumour control. However, this strategy requires accurate detection of the hypoxic sub-volume using PET imaging. Secondly, hypoxia imaging may also provide prognostic information and may be of help to monitor treatment response. Therefore, a systematic review of the scientific literature was carried out on the use of Positron Emission Tomography (PET) to image Tumour hypoxia in non-small cell lung cancer (NSCLC). More specifically, the purpose of this review was (1) to summarize the different hypoxia tracers used, (2) to investigate whether Tumour hypoxia can be detected in NSCLC and finally (3) whether the presence of hypoxia can be used to predict outcome.

  2. Optical imaging of reporter gene expression using a positron-emission-tomography probe

    NASA Astrophysics Data System (ADS)

    Liu, Hongguang; Ren, Gang; Liu, Shuanglong; Zhang, Xiaofen; Chen, Luxi; Han, Peizhen; Cheng, Zhen

    2010-11-01

    Reporter gene/reporter probe technology is one of the most important techniques in molecular imaging. Lately, many reporter gene/reporter probe systems have been coupled to different imaging modalities such as positron emission tomography (PET) and optical imaging (OI). It has been recently found that OI techniques could be used to monitor radioactive tracers in vitro and in living subjects. In this study, we further demonstrate that a reporter gene/nuclear reporter probe system [herpes simplex virus type-1 thymidine kinase (HSV1-tk) and 9-(4-18F-fluoro-3-[hydroxymethyl] butyl) guanine ([18F]FHBG)] could be successfully imaged by OI in vitro and in vivo. OI with radioactive reporter probes will facilitate and broaden the applications of reporter gene/reporter probe techniques in medical research.

  3. Investigation of Abnormal Left Temporal Functioning in Dyslexia through rCBF, Auditory Evoked Potentials, and Positron Emission Tomography.

    ERIC Educational Resources Information Center

    Wood, Frank; And Others

    1991-01-01

    Investigates the proposed left hemisphere dysfunction in dyslexia by reviewing four studies using regional cerebral blood flow (RCBF) and combined auditory evoked responses with positron emission tomography. Emphasizes methodological issues. Finds that dyslexics showed a positive correlation between Heschl's gyrus activation and phonemic…

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

    PubMed

    Gewirtz, Henry; Dilsizian, Vasken

    2016-05-31

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

  5. Rare case of an ovarian vein tumor thrombosis identified on fluorodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Chandra, Piyush; Agrawal, Archi; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2016-01-01

    Fludeoxyglucose positron emission tomography/computed tomography is valuable in the identification of tumor thrombus and differentiating it from bland thrombus which has implications in initiating anticoagulation. We present a rare case of tumor thrombosis in ovarian vein, in a recurrent case of uterine carcinosarcoma. PMID:27833321

  6. Serotonin transporter in attention-deficit hyperactivity disorder--preliminary results from a positron emission tomography study.

    PubMed

    Karlsson, Linnea; Tuominen, Lauri; Huotarinen, Antti; Leppämäki, Sami; Sihvola, Elina; Helin, Semi; Sipilä, Maria; Tani, Pekka; Hirvonen, Jussi; Hietala, Jarmo; Karlsson, Hasse

    2013-05-30

    The serotonin transporter (SERT) in attention-deficit hyperactivity disorder (ADHD) patients has not been explored by earlier positron emission tomography (PET) studies. We measured SERT availability in female ADHD patients (n=8) and healthy controls (n=14) with PET and [11C]MADAM as a tracer. No significant group differences in [11C]MADAM binding potential were noted.

  7. Effective dose to staff members in a positron emission tomography/CT facility using zirconium-89

    PubMed Central

    2013-01-01

    Objective: Positron emission tomography (PET) using zirconium-89 (89Zr) is complicated by its complex decay scheme. In this study, we quantified the effective dose from 89Zr and compared it with fluorine-18 fludeoxyglucose (18F-FDG). Methods: Effective dose distribution in a PET/CT facility in Riyadh was calculated by Monte Carlo simulations using MCNPX. The positron bremsstrahlung, the annihilation photons, the delayed gammas from 89Zr and those emissions from 18F-FDG were modelled in the simulations but low-energy characteristic X-rays were ignored. Results: On the basis of injected activity, the dose from 89Zr was higher than that of 18F-FDG. However, the dose per scan from 89Zr became less than that from 18F-FDG near the patient, owing to the difference in injected activities. In the corridor and control rooms, the 89Zr dose was much higher than 18F-FDG, owing to the difference in attenuation by the shielding materials. Conclusion: The presence of the high-energy photons from 89Zr-labelled immuno-PET radiopharmaceuticals causes a significantly higher effective dose than 18F-FDG to the staff outside the patient room. Conversely, despite the low administered activity of 89Zr, it gives rise to a comparable or even lower dose than 18F-FDG to the staff near the patient. This interesting result raises apparently contradictory implications in the radiation protection considerations of a PET/CT facility. Advances in knowledge: To the best of our knowledge, radiation exposure to staff and public in the PET/CT unit using 89Zr has not been investigated. The ultimate output of this study will lead to the optimal design of the facility for routine use of 89Zr. PMID:23934963

  8. A Conway-Maxwell-Poisson (CMP) model to address data dispersion on positron emission tomography.

    PubMed

    Santarelli, Maria Filomena; Della Latta, Daniele; Scipioni, Michele; Positano, Vincenzo; Landini, Luigi

    2016-10-01

    Positron emission tomography (PET) in medicine exploits the properties of positron-emitting unstable nuclei. The pairs of γ- rays emitted after annihilation are revealed by coincidence detectors and stored as projections in a sinogram. It is well known that radioactive decay follows a Poisson distribution; however, deviation from Poisson statistics occurs on PET projection data prior to reconstruction due to physical effects, measurement errors, correction of deadtime, scatter, and random coincidences. A model that describes the statistical behavior of measured and corrected PET data can aid in understanding the statistical nature of the data: it is a prerequisite to develop efficient reconstruction and processing methods and to reduce noise. The deviation from Poisson statistics in PET data could be described by the Conway-Maxwell-Poisson (CMP) distribution model, which is characterized by the centring parameter λ and the dispersion parameter ν, the latter quantifying the deviation from a Poisson distribution model. In particular, the parameter ν allows quantifying over-dispersion (ν<1) or under-dispersion (ν>1) of data. A simple and efficient method for λ and ν parameters estimation is introduced and assessed using Monte Carlo simulation for a wide range of activity values. The application of the method to simulated and experimental PET phantom data demonstrated that the CMP distribution parameters could detect deviation from the Poisson distribution both in raw and corrected PET data. It may be usefully implemented in image reconstruction algorithms and quantitative PET data analysis, especially in low counting emission data, as in dynamic PET data, where the method demonstrated the best accuracy.

  9. Quantitative evaluation of benzodiazepine receptors in live Papio papio baboons using positron emission tomography

    SciTech Connect

    Brouillet, E.; Chavoix, C.; Khalili-Varasteh, M.; Bottlaender, M.; Hantraye, P.; Yorke, J.C.; Maziere, M. )

    1990-10-01

    The binding of the 11C-labeled benzodiazepine antagonist Ro 15-1788 (flumazenil) was measured in the neocortex of live Papio papio baboons by positron emission tomography. This allowed us to calculate in vivo (i.e., at physiological temperature, neurotransmitters concentrations, and ionic environment) the apparent density of available benzodiazepine receptors (B'max) and the dissociation constant of Ro 15-1788 (Kd). By coadministering increasing doses of unlabeled Ro 15-1788 with (11C)Ro 15-1788 and assuming that nonsaturable radioactivity indicated the free ligand concentration, we were able to obtain saturation isotherms. We showed that a state of quasiequilibrium was reached 50 min after the administration of the radioligand. Linear Scatchard plots allowed us to calculate B'max at 78 and 50 pmol/ml of cerebral tissue in the occipital and frontal cortices, respectively. In both these areas, Kd is on the order of 6 nM, with a Hill number very close to unity. This indicates that Ro 15-1788 binds in vivo with high affinity to an homogeneous population of saturable sites. A similar measurement was carried out on a naturally photosensitive P. papio baboon. Absolute values of B'max, Kd, and Hill number were similar to those of the control baboons. Although results concerning this baboon can only be considered as a case report, this similarity may suggest that its epileptic syndrome is not related to a large change in B'max or Kd, at least in occipital and frontal cortices. Our results showed that quantitative estimation by positron emission tomography of some characteristics of benzodiazepine receptors is possible in live baboons and may represent a supplementary tool for investigating further the molecular mechanisms of benzodiazepine receptor function in physiological and physiopathological conditions.

  10. Microwave accelerated labeling methods in the synthesis of radioligands for positron emission tomography imaging.

    PubMed

    Kallmerten, Amy E; Alexander, Abigail; Wager, Krista M; Jones, Graham B

    2011-10-01

    Nuclear imaging using positron emission tomography [PET] is a powerful technique with clinical applications which include oncology, cardiovascular disease and CNS disorders. Conventional chemical syntheses of the short half-life radionuclides used in the process however imposes numerous limitations on scope of available ligands. By utilizing microwave assisted synthesis methods many of these limitations can be overcome, paving the way for the design of diverse families of agents with defined cellular targets. This review will survey recent developments in the field with emphasis on the period 2006-2011. Positron emission tomography [PET] has become one of the most powerful in vivo imaging modalities, capable of delivering mm3 resolution of radiotracer distribution and metabolism [1]. When combined with anatomic imaging methods (MRI, CT) co-registered multimode images offer the potential to track metabolic and physiologic events in diseased states and guide and accelerate clinical trials of investigational new drugs. Also, this same methodology can be used to evaluate first pass pharmacokinetics/pharmacodynamics in early stage drug discovery. Though powerful as a technique only a limited number of drugs have seen clinical use and to date only one drug 2-fluoro-deoxy-D-glucose (FDG) has received FDA approval [2]. One of the drawbacks of PET imaging is the need for tracers labeled with an appropriate nuclide and the half-lives of these agents places special constraints on the chemical synthesis. Among the most popular are 11C (t½ =20.4 min) and 18F (t ½ =109.8 min) labeled compounds and this has resulted in a resurgence of interest in practical application of their chemistries [3,4]. This review will focus on microwave mediated methods of acceleration of organic reactions used for the production of labeled PET image contrast agents, with emphasis on the five year period 2006 to 2011.

  11. A Lower-Cost High-Resolution LYSO Detector Development for Positron Emission Mammography (PEM)

    PubMed Central

    Ramirez, Rocio A.; Zhang, Yuxuan; Liu, Shitao; Li, Hongdi; Baghaei, Hossain; An, Shaohui; Wang, Chao; Jan, Meei-Ling; Wong, Wai-Hoi

    2010-01-01

    In photomultiplier-quadrant-sharing (PQS) geometry for positron emission tomography applications, each PMT is shared by four blocks and each detector block is optically coupled to four round PMTs. Although this design reduces the cost of high-resolution PET systems, when the camera consists of detector panels that are made up of square blocks, half of the PMT’s sensitive window remains unused at the detector panel edge. Our goal was to develop a LYSO detector panel which minimizes the unused portion of the PMTs for a low-cost, high-resolution, and high-sensitivity positron emission mammography (PEM) camera. We modified the PQS design by using elongated blocks at panel edges and square blocks in the inner area. For elongated blocks, symmetric and asymmetrical reflector patterns were developed and PQS and PMT-half-sharing (PHS) arrangements were implemented in order to obtain a suitable decoding. The packing fraction was 96.3% for asymmetric block and 95.5% for symmetric block. Both of the blocks have excellent decoding capability with all crystals clearly identified, 156 for asymmetric and 144 for symmetric and peak-to-valley ratio of 3.0 and 2.3 respectively. The average energy resolution was 14.2% for the asymmetric block and 13.1% for the symmetric block. Using a modified PQS geometry and asymmetric block design, we reduced the unused PMT region at detector panel edges, thereby increased the field-of-view and the overall detection sensitivity and minimized the undetected breast region near the chest wall. This detector design and using regular round PMT allowed building a lower-cost, high-resolution and high-sensitivity PEM camera. PMID:20485510

  12. Ictal onset zone and seizure propagation delineated on ictal F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

    PubMed

    Tripathi, Madhavi; Tripathi, Manjari; Garg, Ajay; Damle, Nishikant; Bal, Chandrasekhar

    2016-01-01

    The present case highlights the utility of ictal F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in delineating the seizure onset zone in a child with complex partial seizures. Although F-18 FDG PET has been successfully used to delineate interictal hypometabolism, planned ictal FDG PET, in cases with prolonged seizure activity, can provide better spatial resolution than single-photon emission CT by delineating the seizure onset zone and propagation pathway.

  13. Preliminary results for positron emission mammography: real-time functional breast imaging in a conventional mammography gantry.

    PubMed

    Weinberg, I; Majewski, S; Weisenberger, A; Markowitz, A; Aloj, L; Majewski, L; Danforth, D; Mulshine, J; Cowan, K; Zujewski, J; Chow, C; Jones, E; Chang, V; Berg, W; Frank, J

    1996-07-01

    In order to optimally integrate radiotracer breast imaging within the breast clinic, anatomy and pathology should be easily correlated with functional nuclear medicine breast images. As a first step in the development of a hybrid functional/anatomic breast imaging platform with biopsy capability, a conventional X-ray mammography gantry was modified to image the compressed breast with positron emitters. Phantom studies with the positron emission mammography (PEM) device showed that a 1-cc hot spot could be detected within 5 min. A preliminary clinical trial demonstrated in vivo visualization of primary breast cancer within 4 min. For sites where positron-emitting radionuclides are available, PEM promises to achieve low-cost directed functional examination of breast abnormalities, with the potential for achieving X-ray correlation and image-guided biopsy.

  14. Real-time tumor tracking using implanted positron emission markers: concept and simulation study.

    PubMed

    Xu, Tong; Wong, Jerry T; Shikhaliev, Polad M; Ducote, Justin L; Al-Ghazi, Muthana S; Molloi, Sabee

    2006-07-01

    The delivery accuracy of radiation therapy for pulmonary and abdominal tumors suffers from tumor motion due to respiration. Respiratory gating should be applied to avoid the use of a large target volume margin that results in a substantial dose to the surrounding normal tissue. Precise respiratory gating requires the exact spatial position of the tumor to be determined in real time during treatment. Usually, fiducial markers are implanted inside or next to the tumor to provide both accurate patient setup and real-time tumor tracking. However, current tumor tracking systems require either substantial x-ray exposure to the patient or large fiducial markers that limit the value of their application for pulmonary tumors. We propose a real-time tumor tracking system using implanted positron emission markers (PeTrack). Each marker will be labeled with low activity positron emitting isotopes, such as 124I, 74As, or 84Rb. These isotopes have half-lives comparable to the duration of radiation therapy (from a few days to a few weeks). The size of the proposed PeTrack marker will be 0.5-0.8 mm, which is approximately one-half the size of markers currently employed in other techniques. By detecting annihilation gammas using position-sensitive detectors, multiple positron emission markers can be tracked in real time. A multimarker localization algorithm was developed using an Expectation-Maximization clustering technique. A Monte Carlo simulation model was developed for the PeTrack system. Patient dose, detector sensitivity, and scatter fraction were evaluated. Depending on the isotope, the lifetime dose from a 3.7 MBq PeTrack marker was determined to be 0.7-5.0 Gy at 10 mm from the marker. At the center of the field of view (FOV), the sensitivity of the PeTrack system was 240-320 counts/s per 1 MBq marker activity within a 30 cm thick patient. The sensitivity was reduced by 45% when the marker was near the edge of the FOV. The scatter fraction ranged from 12% (124I, 74As) to

  15. Real-time tumor tracking using implanted positron emission markers: Concept and simulation study

    SciTech Connect

    Xu Tong; Wong, Jerry T.; Shikhaliev, Polad M.; Ducote, Justin L.; Al-Ghazi, Muthana S.; Molloi, Sabee

    2006-07-15

    The delivery accuracy of radiation therapy for pulmonary and abdominal tumors suffers from tumor motion due to respiration. Respiratory gating should be applied to avoid the use of a large target volume margin that results in a substantial dose to the surrounding normal tissue. Precise respiratory gating requires the exact spatial position of the tumor to be determined in real time during treatment. Usually, fiducial markers are implanted inside or next to the tumor to provide both accurate patient setup and real-time tumor tracking. However, current tumor tracking systems require either substantial x-ray exposure to the patient or large fiducial markers that limit the value of their application for pulmonary tumors. We propose a real-time tumor tracking system using implanted positron emission markers (PeTrack). Each marker will be labeled with low activity positron emitting isotopes, such as {sup 124}I, {sup 74}As, or {sup 84}Rb. These isotopes have half-lives comparable to the duration of radiation therapy (from a few days to a few weeks). The size of the proposed PeTrack marker will be 0.5-0.8 mm, which is approximately one-half the size of markers currently employed in other techniques. By detecting annihilation gammas using position-sensitive detectors, multiple positron emission markers can be tracked in real time. A multimarker localization algorithm was developed using an Expectation-Maximization clustering technique. A Monte Carlo simulation model was developed for the PeTrack system. Patient dose, detector sensitivity, and scatter fraction were evaluated. Depending on the isotope, the lifetime dose from a 3.7 MBq PeTrack marker was determined to be 0.7-5.0 Gy at 10 mm from the marker. At the center of the field of view (FOV), the sensitivity of the PeTrack system was 240-320 counts/s per 1 MBq marker activity within a 30 cm thick patient. The sensitivity was reduced by 45% when the marker was near the edge of the FOV. The scatter fraction ranged from 12

  16. Vision 20/20: Positron emission tomography in radiation therapy planning, delivery, and monitoring

    SciTech Connect

    Parodi, Katia

    2015-12-15

    Positron emission tomography (PET) is increasingly considered as an effective imaging method to support several stages of radiation therapy. The combined usage of functional and morphological imaging in state-of-the-art PET/CT scanners is rapidly emerging to support the treatment planning process in terms of improved tumor delineation, and to assess the tumor response in follow-up investigations after or even during the course of fractionated therapy. Moreover, active research is being pursued on new tracers capable of providing different insights into tumor function, in order to identify areas of the planning volume which may require additional dosage for improved probability of tumor control. In this respect, major progresses in the next years will likely concern the development and clinical investigation of novel tracers and image processing techniques for reliable thresholding and segmentation, of treatment planning and beam delivery approaches integrating the PET imaging information, as well as improved multimodal clinical instrumentation such as PET/MR. But especially in the rapidly emerging case of ion beam therapy, the usage of PET is not only limited to the imaging of external tracers injected to the patient. In fact, a minor amount of positron emitters is formed in nuclear fragmentation reactions between the impinging ions and the tissue, bearing useful information for confirmation of the delivered treatment during or after therapeutic irradiation. Different implementations of unconventional PET imaging for therapy monitoring are currently being investigated clinically, and major ongoing research aims at new dedicated detector technologies and at challenging applications such as real-time imaging and time-resolved in vivo verification of motion compensated beam delivery. This paper provides an overview of the different areas of application of PET in radiation oncology and discusses the most promising perspectives in the years to come for radiation therapy

  17. Optimised motion tracking for positron emission tomography studies of brain function in awake rats.

    PubMed

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

    2011-01-01

    Positron emission tomography (PET) is a non-invasive molecular imaging technique using positron-emitting radioisotopes to study functional processes within the body. High resolution PET scanners designed for imaging rodents and non-human primates are now commonplace in preclinical research. Brain imaging in this context, with motion compensation, can potentially enhance the usefulness of PET by avoiding confounds due to anaesthetic drugs and enabling freely moving animals to be imaged during normal and evoked behaviours. Due to the frequent and rapid motion exhibited by alert, awake animals, optimal motion correction requires frequently sampled pose information and precise synchronisation of these data with events in the PET coincidence data stream. Motion measurements should also be as accurate as possible to avoid degrading the excellent spatial resolution provided by state-of-the-art scanners. Here we describe and validate methods for optimised motion tracking suited to the correction of motion in awake rats. A hardware based synchronisation approach is used to achieve temporal alignment of tracker and scanner data to within 10 ms. We explored the impact of motion tracker synchronisation error, pose sampling rate, rate of motion, and marker size on motion correction accuracy. With accurate synchronisation (<100 ms error), a sampling rate of >20 Hz, and a small head marker suitable for awake animal studies, excellent motion correction results were obtained in phantom studies with a variety of continuous motion patterns, including realistic rat motion (<5% bias in mean concentration). Feasibility of the approach was also demonstrated in an awake rat study. We conclude that motion tracking parameters needed for effective motion correction in preclinical brain imaging of awake rats are achievable in the laboratory setting. This could broaden the scope of animal experiments currently possible with PET.

  18. [Neurotransmitter systems in the human brain studied by positron emission tomography].

    PubMed

    Shinotoh, H

    1996-12-01

    Positron emission tomography with appropriate tracers provides unique opportunity to study neurotransmitter systems in the living human brain. PET with [18F] 6-fluoro-L-dopa (FD) provides an index of the integrity of nigrostriatal pathway, and striatal FD uptake correlates linearly with the density of nigral neurons. PET allows us to assess the progression of the nigral lesions in Parkinson's disease (PD). A 68-year-old normal female volunteer was scanned by FD-PET. Subsequently, she developed parkinsonism 3.7 years after the scan. A repeated FD-PET scan revealed a significant reduction of FD uptake by 20% over the 5.2 year interval. The results suggest a relatively short presymptomatic period with fast initial losses of nigral neurons in PD. FD-PET has been used to determine the viability of fetal graft implanted in the striatum for the treatment of PD. PET imaging of dopamine D1 and D2 receptors may be useful for the differential diagnosis of PD and striatonigral degeneration. PET reveals significant reduction of dopamine D1 and D2 receptor binding in the putamen of patients with SND, while D1 and D2 receptor binding is normal or slightly upregulated in PD. We found hypersensitivity of muscarinic cholinergic receptors in the frontal cortex of patients with PD by using PET. The result suggests a loss of ascending cholinergic system in the frontal cortex in PD, which may cause the frontal lobe dysfunction in PD. Recently, acetylcholine analogs labelled with positron emitter have been developed for measurement of brain acetylcholinesterase activity in vivo. These tracers may be useful for the assessment of ascending cholinergic system in Alzheimer's disease and PD.

  19. Analysis of optimum diameter of orbit of transmission line source in positron emission tomograph

    SciTech Connect

    Yamamoto, S.; Amano, M.; Hirose, Y.; Muira, S.; Kanno, I.

    1989-02-01

    Accurate attenuation correction is one of the most important factors to achieve quantitative measurements in positron emission tomography (PET). A transmission scan is most commonly used technique for the attenuation correction in PET. A difficulty in transmission scan is relatively long period to obtain a data with good signal-to-noise ratio. Insufficient signal-to-noise ratio of the transmission data limits that of emission data. Several approaches were reported to improve the transmission data. Those were (1) optimizing of detector threshold, (2) processing delayed coincidence sinogram before subtraction, filtering of transmission sinogram before performing attenuation correction, and (3) rejection of random and scatter coincidence by using rotating line source and information of its position. In some of these methods, additional calculation time or processing hardware is needed. The authors have estimated a relationship between ring diameter of a transmission line source and signal to noise ratio of the transmission dat. This paper aimes to analyze optimum diameter of the orbit of transmission line source in concerning to signal to noise ratio in transmission data.

  20. Graphics processing unit (GPU)-accelerated particle filter framework for positron emission tomography image reconstruction.

    PubMed

    Yu, Fengchao; Liu, Huafeng; Hu, Zhenghui; Shi, Pengcheng

    2012-04-01

    As a consequence of the random nature of photon emissions and detections, the data collected by a positron emission tomography (PET) imaging system can be shown to be Poisson distributed. Meanwhile, there have been considerable efforts within the tracer kinetic modeling communities aimed at establishing the relationship between the PET data and physiological parameters that affect the uptake and metabolism of the tracer. Both statistical and physiological models are important to PET reconstruction. The majority of previous efforts are based on simplified, nonphysical mathematical expression, such as Poisson modeling of the measured data, which is, on the whole, completed without consideration of the underlying physiology. In this paper, we proposed a graphics processing unit (GPU)-accelerated reconstruction strategy that can take both statistical model and physiological model into consideration with the aid of state-space evolution equations. The proposed strategy formulates the organ activity distribution through tracer kinetics models and the photon-counting measurements through observation equations, thus making it possible to unify these two constraints into a general framework. In order to accelerate reconstruction, GPU-based parallel computing is introduced. Experiments of Zubal-thorax-phantom data, Monte Carlo simulated phantom data, and real phantom data show the power of the method. Furthermore, thanks to the computing power of the GPU, the reconstruction time is practical for clinical application.

  1. Clustering-initiated factor analysis application for tissue classification in dynamic brain positron emission tomography.

    PubMed

    Boutchko, Rostyslav; Mitra, Debasis; Baker, Suzanne L; Jagust, William J; Gullberg, Grant T

    2015-07-01

    The goal is to quantify the fraction of tissues that exhibit specific tracer binding in dynamic brain positron emission tomography (PET). It is achieved using a new method of dynamic image processing: clustering-initiated factor analysis (CIFA). Standard processing of such data relies on region of interest analysis and approximate models of the tracer kinetics and of tissue properties, which can degrade accuracy and reproducibility of the analysis. Clustering-initiated factor analysis allows accurate determination of the time-activity curves and spatial distributions for tissues that exhibit significant radiotracer concentration at any stage of the emission scan, including the arterial input function. We used this approach in the analysis of PET images obtained using (11)C-Pittsburgh Compound B in which specific binding reflects the presence of β-amyloid. The fraction of the specific binding tissues determined using our approach correlated with that computed using the Logan graphical analysis. We believe that CIFA can be an accurate and convenient tool for measuring specific binding tissue concentration and for analyzing tracer kinetics from dynamic images for a variety of PET tracers. As an illustration, we show that four-factor CIFA allows extraction of two blood curves and the corresponding distributions of arterial and venous blood from PET images even with a coarse temporal resolution.

  2. Simulation study of respiratory-induced errors in cardiac positron emission tomography/computed tomography

    SciTech Connect

    Fitzpatrick, Gianna M.; Wells, R. Glenn

    2006-08-15

    Heart disease is a leading killer in Canada and positron emission tomography (PET) provides clinicians with in vivo metabolic information for diagnosing heart disease. Transmission data are usually acquired with {sup 68}Ge, although the advent of PET/CT scanners has made computed tomography (CT) an alternative option. The fast data acquisition of CT compared to PET may cause potential misregistration problems, leading to inaccurate attenuation correction (AC). Using Monte Carlo simulations and an anthropomorphic dynamic computer phantom, this study determines the magnitude and location of respiratory-induced errors in radioactivity uptake measured in cardiac PET/CT. A homogeneous tracer distribution in the heart was considered. The AC was based on (1) a time-averaged attenuation map (2) CT maps from a single phase of the respiratory cycle, and (3) CT maps phase matched to the emission data. Circumferential profiles of the heart uptake were compared and differences of up to 24% were found between the single-phase CT-AC method and the true phantom values. Simulation results were supported by a PET/CT canine study which showed differences of up to 10% in the heart uptake in the lung-heart boundary region when comparing {sup 68}Ge- to CT-based AC with the CT map acquired at end inhalation.

  3. Fluorodeoxyglucose-positron emission tomography in carcinoma nasopharynx: Can we predict outcomes and tailor therapy based on postradiotherapy fluorodeoxyglucose-positron emission tomography?

    PubMed Central

    Laskar, Sarbani Ghosh; Baijal, Gunjan; Rangarajan, Venkatesh; Purandare, Nilendu; Sengar, Manju; Shah, Sneha; Gupta, Tejpal; Budrukkar, Ashwini; Murthy, Vedang; Pai, Prathamesh S.; D’Cruz, A. K.; Agarwal, J. P.

    2016-01-01

    Background: Positron emission tomography-computed tomography (PET-CT) is an emerging modality for staging and response evaluation in carcinoma nasopharynx. This study was conducted to evaluate the impact of PET-CT in assessing response and outcomes in carcinoma nasopharynx. Materials and Methods: Forty-five patients of nonmetastatic carcinoma nasopharynx who underwent PET-CT for response evaluation at 10-12 weeks posttherapy between 2004 and 2009 were evaluated. Patients were classified as responders (Group A) if there was a complete response on PET-CT or as nonresponders (Group B) if there was any uptake above the background activity. Data regarding demographics, treatment, and outcomes were collected from their records and compared across the Groups A and B. Results: The median age was 41 years. 42 out of 45 (93.3%) patients had WHO Grade 2B disease (undifferentiated squamous carcinoma). 24.4%, 31.1%, 15.6, and 28.8% patients were in American Joint Committee on Cancer Stage IIb, III, Iva, and IVb. All patients were treated with neoadjuvant chemotherapy followed by concomitant chemoradiotherapy. Forty-five patients, 28 (62.2%) were classified as responders, whereas 17 (37.8%) were classified as nonresponders. There was no significant difference in the age, sex, WHO grade, and stage distribution between the groups. Compliance to treatment was comparable across both groups. The median follow-up was 25.3 months (759 days). The disease-free survival (DFS) of the group was 57.3% at 3 years. The DFS at 3 years was 87.3% and 19.7% for Group A and B, respectively (log-rank test, P < 0.001). Univariate and multivariate analysis revealed Groups to be the only significant factor predicting DFS (P value 0.002 and < 0.001, respectively). In Group B, the most common site of disease failure was distant (9, 53%). Conclusion: PET-CT can be used to evaluate response and as a tool to identify patients at higher risk of distant failure. Further, this could be exploited to identify

  4. CO2BOLD assessment of moyamoya syndrome: Validation with single photon emission computed tomography and positron emission tomography imaging

    PubMed Central

    Pellaton, Alain; Bijlenga, Philippe; Bouchez, Laurie; Cuvinciuc, Victor; Barnaure, Isabelle; Garibotto, Valentina; Lövblad, Karl-Olof; Haller, Sven

    2016-01-01

    AIM To compare the assessment of cerebrovascular reserve (CVR) using CO2BOLD magnetic resonance imaging (MRI) vs positron emission tomography (PET) and single photon emission computed tomography (SPECT) as reference standard. METHODS Ten consecutive patients (8 women, mean age of 41 ± 26 years) with moyamoya syndrome underwent 14 pre-surgical evaluations for external-internal carotid artery bypass surgery. CVR was assessed using CO2BOLD and PET (4)/SPECT (11) with a maximum interval of 36 d, and evaluated by two experienced neuroradiologists. RESULTS The inter-rater agreement was 0.81 for SPECT (excellent), 0.43 for PET (fair) and 0.7 for CO2BOLD (good). In 9/14 cases, there was a correspondence between CO2BOLD and PET/SPECT. In 4/14 cases, CVR was over-estimated in CO2BOLD, while in 1/14 case, CVR was underestimated in CO2BOLD. The sensitivity of CO2BOLD was 86% and a specificity of 43%. CONCLUSION CO2BOLD can be used for pre-surgical assessment of CVR in patients with moyamoya syndrome and combines the advantages of absent irradiation, high availability of MRI and assessment of brain parenchyma, cerebral vessels and surrogate CVR in one stop. PMID:27928470

  5. Technical aspects of real time positron emission tracking for gated radiotherapy

    SciTech Connect

    Chamberland, Marc; Xu, Tong; McEwen, Malcolm R.

    2016-02-15

    Purpose: Respiratory motion can lead to treatment errors in the delivery of radiotherapy treatments. Respiratory gating can assist in better conforming the beam delivery to the target volume. We present a study of the technical aspects of a real time positron emission tracking system for potential use in gated radiotherapy. Methods: The tracking system, called PeTrack, uses implanted positron emission markers and position sensitive gamma ray detectors to track breathing motion in real time. PeTrack uses an expectation–maximization algorithm to track the motion of fiducial markers. A normalized least mean squares adaptive filter predicts the location of the markers a short time ahead to account for system response latency. The precision and data collection efficiency of a prototype PeTrack system were measured under conditions simulating gated radiotherapy. The lung insert of a thorax phantom was translated in the inferior–superior direction with regular sinusoidal motion and simulated patient breathing motion (maximum amplitude of motion ±10 mm, period 4 s). The system tracked the motion of a {sup 22}Na fiducial marker (0.34 MBq) embedded in the lung insert every 0.2 s. The position of the was marker was predicted 0.2 s ahead. For sinusoidal motion, the equation used to model the motion was fitted to the data. The precision of the tracking was estimated as the standard deviation of the residuals. Software was also developed to communicate with a Linac and toggle beam delivery. In a separate experiment involving a Linac, 500 monitor units of radiation were delivered to the phantom with a 3 × 3 cm photon beam and with 6 and 10 MV accelerating potential. Radiochromic films were inserted in the phantom to measure spatial dose distribution. In this experiment, the period of motion was set to 60 s to account for beam turn-on latency. The beam was turned off when the marker moved outside of a 5-mm gating window. Results: The precision of the tracking in the IS

  6. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  7. Noninvasive quantification of muscarinic receptors in vivo with positron emission tomography in the dog heart

    SciTech Connect

    Delforge, J.; Janier, M.; Syrota, A.; Crouzel, C.; Vallois, J.M.; Cayla, J.; Lancon, J.P.; Mazoyer, B.M. )

    1990-10-01

    The in vivo quantification of myocardial muscarinic receptors has been obtained in six closed-chest dogs by using positron emission tomography. The dogs were injected with a trace amount of 11C-labeled methylquinuclidinyl benzilate (MQNB), a nonmetabolized antagonist of the muscarinic receptor. This was followed 30 minutes later by an injection of an excess of unlabeled MQNB (displacement experiment). Two additional injections of unlabeled MQNB with (11C)MQNB and without (11C)MQNB (second displacement experiment) were administered after 70 and 120 minutes, respectively. This protocol allowed a separate evaluation of the quantity of available receptors (B'max) as well as the association and dissociation rate constants (k+1 and k-1) in each dog. The parameters were calculated by using a nonlinear mathematical model in regions of interest over the left ventricle and the interventricular septum. The average value of B'max was 42 +/- 11 pmol/ml tissue, the rate constants k+1, k-1, and Kd were 0.6 +/- 0.1 ml.pmol-1.min-1, 0.27 +/- 0.03 ml.pmol-1.min-1, and 0.49 +/- 0.14 pmol.ml-1, respectively, taking into account the MQNB reaction volume estimated to 0.15 ml/ml tissue. Although (11C)MQNB binding would appear irreversible, our findings indicate that the association of the antagonist is very rapid and that the dissociation is far from negligible. The dissociated ligand, however, has a high probability of rebinding to a free receptor site instead of escaping into the microcirculation. We deduce that the positron emission tomographic images obtained after injecting a trace amount of (11C)MQNB are more representative of blood flow than of receptor density or affinity. We also suggest a simplified protocol consisting of a tracer injection of (11C)MQNB and a second injection of an excess of cold MQNB, which is sufficient to measure B'max and Kd in humans.

  8. High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography

    SciTech Connect

    Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; Kim, H.; Chen, C.; Kao, C.; Niessen, K.; Zatserklyaniy, A.; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

    2011-02-01

    We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high voltage

  9. A novel image reconstruction methodology based on inverse Monte Carlo analysis for positron emission tomography

    NASA Astrophysics Data System (ADS)

    Kudrolli, Haris A.

    2001-04-01

    A three dimensional (3D) reconstruction procedure for Positron Emission Tomography (PET) based on inverse Monte Carlo analysis is presented. PET is a medical imaging modality which employs a positron emitting radio-tracer to give functional images of an organ's metabolic activity. This makes PET an invaluable tool in the detection of cancer and for in-vivo biochemical measurements. There are a number of analytical and iterative algorithms for image reconstruction of PET data. Analytical algorithms are computationally fast, but the assumptions intrinsic in the line integral model limit their accuracy. Iterative algorithms can apply accurate models for reconstruction and give improvements in image quality, but at an increased computational cost. These algorithms require the explicit calculation of the system response matrix, which may not be easy to calculate. This matrix gives the probability that a photon emitted from a certain source element will be detected in a particular detector line of response. The ``Three Dimensional Stochastic Sampling'' (SS3D) procedure implements iterative algorithms in a manner that does not require the explicit calculation of the system response matrix. It uses Monte Carlo techniques to simulate the process of photon emission from a source distribution and interaction with the detector. This technique has the advantage of being able to model complex detector systems and also take into account the physics of gamma ray interaction within the source and detector systems, which leads to an accurate image estimate. A series of simulation studies was conducted to validate the method using the Maximum Likelihood - Expectation Maximization (ML-EM) algorithm. The accuracy of the reconstructed images was improved by using an algorithm that required a priori knowledge of the source distribution. Means to reduce the computational time for reconstruction were explored by using parallel processors and algorithms that had faster convergence rates

  10. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

    NASA Astrophysics Data System (ADS)

    Christensen, A. N.; Rydhög, J. S.; Søndergaard, R. V.; Andresen, T. L.; Holm, S.; Munck Af Rosenschöld, P.; Conradsen, K.; Jølck, R. I.

    2016-05-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively.Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The

  11. Primary Pulmonary Epithelioid Hemangioendothelioma: A Rare Cause of PET-Negative Pulmonary Nodules

    PubMed Central

    Cazzuffi, Riccardo; Calia, Nunzio; Ravenna, Franco; Pasquini, Claudio; Saturni, Sara; Cavallesco, Giorgio Narciso; Quarantotto, Francesco; Rinaldi, Rosa; Cogo, Annaluisa; Caramori, Gaetano; Papi, Alberto

    2011-01-01

    We report here a case of primary pulmonary epithelioid hemangioendothelioma diagnosed in a 67-year-old Caucasian man, presenting with exertion dyspnoea, dry cough, and multiple bilateral pulmonary nodules revealed by computed tomography. At the 18F-fluorodeoxyglucose positron emission tomography, these nodules were negative. The histopathological diagnosis was made on a pulmonary wedge resection (performed during video-thoracoscopic surgery). PMID:21869893

  12. Primary central nervous system lymphoma with lymphomatosis cerebri in an immunocompetent child: MRI and 18F-FDG PET-CT findings.

    PubMed

    Jain, Tarun K; Sharma, Punit; Suman, Sudhir K C; Faizi, Nauroze A; Bal, Chandrasekhar; Kumar, Rakesh

    2013-01-01

    Primary central nervous system lymphoma (PCNSL) is extremely rare in immunocompetent children. We present the magnetic resonance imaging (MRI) and (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) findings of such a case in a 14-year old immunocompetent boy. In this patient, PCNSL was associated with lymphomatosis cerebri. Familiarity with the findings of this rare condition will improve the diagnostic confidence of the nuclear radiologist and avoid misdiagnosis.

  13. Differential diagnosis of solitary pulmonary nodules with positron emission tomography using (/sup 11/C)L-methionine

    SciTech Connect

    Kubota, K.; Matsuzawa, T.; Fujiwara, T.; Abe, Y.; Ito, M.; Hatazawa, J.; Ido, T.; Ishiwata, K.; Watanuki, S.

    1988-09-01

    Two patients with solitary pulmonary nodules, 1.5-2.0 cm in diameter, were studied by positron emission tomography using (/sup 11/C-Methyl)L-methionine (/sup 11/C-Met). Case 1 showed high accumulation of /sup 11/C-Met in the tumor, and a tumor/muscle ratio of 6.0 suggesting malignancy. Tissue obtained by biopsy revealed a squamous cell carcinoma. Case 2 showed nonspecific isotope accumulation in the tumor, and a tumor/muscle ratio of 1.2 suggesting a benign lesion. Lung biopsy demonstrated granuloma. Positron emission tomography with /sup 11/C-Met seems to be useful for the differential diagnosis of solitary lung nodules.

  14. Development of EndoTOFPET-US, a multi-modal endoscope for ultrasound and time of flight positron emission tomography

    NASA Astrophysics Data System (ADS)

    Pizzichemi, M.

    2014-02-01

    The EndoTOFPET-US project aims at delevoping a multi-modal imaging device that combines Ultrasound with Time-Of-Flight Positron Emission Tomography into an endoscopic imaging device. The goal is to obtain a coincidence time resolution of about 200 ps FWHM and sub-millimetric spatial resolution for the PET head, integrating the components in a very compact detector suitable for endoscopic use. The scanner will be exploited for the clinical test of new bio-markers especially targeted for prostate and pancreatic cancer as well as for diagnostic and surgical oncology. This paper focuses on the status of the Time-Of-Flight Positron Emission Tomograph under development for the EndoTOFPET-US project.

  15. Amyloid deposition after cerebral hypoperfusion: evidenced on [(18)F]AV-45 positron emission tomography.

    PubMed

    Huang, Kuo-Lun; Lin, Kun-Ju; Ho, Meng-Yang; Chang, Yeu-Jhy; Chang, Chien-Hung; Wey, Shiaw-Pyng; Hsieh, Chia-Ju; Yen, Tzu-Chen; Hsiao, Ing-Tsung; Lee, Tsong-Hai

    2012-08-15

    Animal studies have shown that cerebral hypoperfusion may be associated with amyloid plaque accumulation. Amyloid plaque is known to be associated with dementia and [(18)F]AV-45 is a positron emission tomography (PET) ligand that binds to extracelluar plaques. We hypothesized that demented patients with cerebral hypoperfusion may have increased [(18)F]AV-45 uptake. Five demented patients with cerebral hypoperfusion due to unilateral carotid artery stenosis (CAS) were examined with [(18)F]AV-45 PET, and the results were compared with six elderly controls. The standard uptake value ratio (SUVR) of each region of interest (ROI) was created using whole cerebellum as the reference region. All subjects underwent magnetic resonance imaging (MRI) for obtaining structural information. Patients with dementia and unilateral CAS had a higher global [(18)F]AV-45 SUVR (1.34 ± 0.06) as compared with controls (1.10 ± 0.04, p=0.0043), especially over the frontal, temporal, precuneus, anterior cingulate and occipital regions. The statistical distribution maps revealed a significantly increased [(18)F]AV-45 SUVR in the medial frontal, caudate, thalamus, posterior cingulate, occipital and middle and superior temporal regions ipsilateral to the side of CAS (p<0.01). The present study found that cerebral [(18)F]AV-45 binding is increased in demented patients with CAS, and its distribution is lateralized to the CAS side, suggesting that amyloid-related dementia may occur under cerebral hypoperfusion.

  16. Positron emission mammography with tomographic acquisition using dual planar detectors: initial evaluations

    SciTech Connect

    Mark F Smith; Raymond R Raylman; Stan Majewski; Andrew G Weisenberger

    2004-05-01

    Positron emission mammography (PEM) with tomographic acquisition using dual planar detectors rotating about the breast can obtain complete angular sampling and has the potential to improve activity estimation compared with PEM using stationary detectors. PEM tomography (PEMT) was compared with stationary PEM for point source and compressed breast phantom studies performed with a compact dual detector system. The acquisition geometries were appropriate for the target application of PEM guidance of stereotactic core biopsy. Images were reconstructed with a three-dimensional iterative maximum likelihood expectation maximization algorithm. PEMT eliminated blurring normal to the detectors seen with stationary PEM. Depth of interaction effects distorted the shape of the point spread functions for PEMT as the angular range from normal incidence of lines of response used in image reconstruction increased. Streak artifacts in PEMT for large detector rotation increments led to the development of an expression for the maximum rotation increment that maintains complete angular sampling. Studies with a compressed breast phantom were used to investigate contrast and signal-to-noise ratio (SNR) trade-offs for different sized spherical tumor models. PEMT and PEM both had advantages depending on lesion size and detector separation. The most appropriate acquisition method for specific detection or quantitation tasks requires additional investigation.

  17. Positron Emission Tomography to Elucidate Pharmacokinetic Differences of Regioisomeric Retinoid X Receptor Agonists

    PubMed Central

    2015-01-01

    RXR partial agonist NEt-4IB (2a, 6-[ethyl-(4-isobutoxy-3-isopropylphenyl)amino]pyridine-3-carboxylic acid: EC50 = 169 nM, Emax = 55%) showed a blood concentration higher than its Emax after single oral administration at 30 mg/kg to mice, and repeated oral administration at 10 mg/kg/day to KK-Ay mice afforded antitype 2 diabetes activity without the side effects caused by RXR full agonists. However, RXR full agonist NEt-3IB (1a), in which the isobutoxy and isopropyl groups of 2a are interchanged, gave a much lower blood concentration than 2a. Here we used positron emission tomography (PET) with tracers [11C]1a, [11C]2a and fluorinated derivatives [18F]1b, [18F]2b, which have longer half-lives, to examine the reason why 1a and 2a exhibited significantly different blood concentrations. As a result, the reason for the high blood concentration of 2a after oral administration was found to be linked to higher intestinal absorbability together with lower biliary excretion, compared with 1a. PMID:25815156

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

    PubMed

    Hou, Haifeng; Tian, Mei; Zhang, Hong

    2012-05-01

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

  19. Regional changes in extravascular lung water detected by positron emission tomography

    SciTech Connect

    Schuster, D.P.; Marklin, G.F.; Mintun, M.A.

    1986-04-01

    Regional measurements of extravascular lung water (rEVLW) were made with positron emission tomography (PET) and 15O-labeled radionuclides. The label used to measure the total lung water (TLW) content fully equilibrated with TLW prior to scanning in both dogs with normal and low cardiac outputs, and nearly so in areas of lung made edematous by oleic acid injury (the TLW values used were 97% of maximum values). Regional EVLW measurements made by PET (EVLW-PET) and gravimetric techniques in both normal and edematous lung were closely correlated (r = 0.93), and EVLW-PET increased from an average of 0.20 to 0.37 mlH/sub 2/O/ml lung (P less than 0.05) after regional lung injury. PET measurements of regional blood volume always decreased (from an average of 0.12 to 0.09 ml blood/ml lung (P less than 0.05)) after cardiac output was lowered by hemorrhage in a separate set of animals. Total EVLW (by thermodye indicator dilution) did not change. Likewise, regional EVLW remained constant in areas below the left atrium but decreased in areas above the left atrium. We conclude that PET measurements are accurate, noninvasive, and reproducible and that regional changes may be detected even when measurements of total EVLW by other methods may fail to change significantly.

  20. Modelling Random Coincidences in Positron Emission Tomography by Using Singles and Prompts: A Comparison Study

    PubMed Central

    2016-01-01

    Random coincidences degrade the image in Positron Emission Tomography, PET. To compensate for their degradation effects, the rate of random coincidences should be estimated. Under certain circumstances, current estimation methods fail to provide accurate results. We propose a novel method, “Singles–Prompts” (SP), that includes the information conveyed by prompt coincidences and models the pile–up. The SP method has the same structure than the well-known “Singles Rate” (SR) approach. Hence, SP can straightforwardly replace SR. In this work, the SP method has been extensively assessed and compared to two conventional methods, SR and the delayed window (DW) method, in a preclinical PET scenario using Monte–Carlo simulations. SP offers accurate estimates for the randoms rates, while SR and DW tend to overestimate the rates (∼10%, and 5%, respectively). With pile-up, the SP method is more robust than SR (but less than DW). At the image level, the contrast is overestimated in SR-corrected images, +16%, while SP produces the correct value. Spill–over is slightly reduced using SP instead of SR. The DW images values are similar to those of SP except for low-statistic scenarios, where DW behaves as if randoms were not compensated for. In particular, the contrast is reduced, −16%. In general, the better estimations of SP translate into better image quality. PMID:27603143

  1. Comparison of three image segmentation techniques for target volume delineation in positron emission tomography.

    PubMed

    Drever, Laura A; Roa, Wilson; McEwan, Alexander; Robinson, Don

    2007-03-09

    Incorporation of positron emission tomography (PET) data into radiotherapy planning is currently under investigation for numerous sites including lung, brain, head and neck, breast, and prostate. Accurate tumor-volume quantification is essential to the proper utilization of the unique information provided by PET. Unfortunately,target delineation within PET currently remains a largely unaddressed problem. We therefore examined the ability of three segmentation methods-thresholding, Sobel edge detection, and the watershed approach-to yield accurate delineation of PET target cross-sections. A phantom study employing well-defined cylindrical and spherical volumes and activity distributions provided an opportunity to assess the relative efficacy with which the three approaches could yield accurate target delineation in PET. Results revealed that threshold segmentation can accurately delineate target cross-sections, but that the Sobel and watershed techniques both consistently fail to correctly identify the size of experimental volumes. The usefulness of threshold-based segmentation is limited, however, by the dependence of the correct threshold (that which returns the correct area at each image slice) on target size.

  2. Positron Emission Tomography Reveals Abnormal Topological Organization in Functional Brain Network in Diabetic Patients

    PubMed Central

    Qiu, Xiangzhe; Zhang, Yanjun; Feng, Hongbo; Jiang, Donglang

    2016-01-01

    Recent studies have demonstrated alterations in the topological organization of structural brain networks in diabetes mellitus (DM). However, the DM-related changes in the topological properties in functional brain networks are unexplored so far. We therefore used fluoro-D-glucose positron emission tomography (FDG-PET) data to construct functional brain networks of 73 DM patients and 91 sex- and age-matched normal controls (NCs), followed by a graph theoretical analysis. We found that both DM patients and NCs had a small-world topology in functional brain network. In comparison to the NC group, the DM group was found to have significantly lower small-world index, lower normalized clustering coefficients and higher normalized characteristic path length. Moreover, for diabetic patients, the nodal centrality was significantly reduced in the right rectus, the right cuneus, the left middle occipital gyrus, and the left postcentral gyrus, and it was significantly increased in the orbitofrontal region of the left middle frontal gyrus, the left olfactory region, and the right paracentral lobule. Our results demonstrated that the diabetic brain was associated with disrupted topological organization in the functional PET network, thus providing functional evidence for the abnormalities of brain networks in DM. PMID:27303259

  3. Quantitative experimental monitoring of molecular diffusion in clay with positron emission tomography

    NASA Astrophysics Data System (ADS)

    Kulenkampff, Johannes; Zakhnini, Abdelhamid; Gründig, Marion; Lippmann-Pipke, Johanna

    2016-08-01

    Clay plays a prominent role as barrier material in the geosphere. The small particle sizes cause extremely small pore sizes and induce low permeability and high sorption capacity. Transport of dissolved species by molecular diffusion, driven only by a concentration gradient, is less sensitive to the pore size. Heterogeneous structures on the centimetre scale could cause heterogeneous effects, like preferential transport zones, which are difficult to assess. Laboratory measurements with diffusion cells yield limited information on heterogeneity, and pore space imaging methods have to consider scale effects. We established positron emission tomography (PET), applying a high-resolution PET scanner as a spatially resolved quantitative method for direct laboratory observation of the molecular diffusion process of a PET tracer on the prominent scale of 1-100 mm. Although PET is rather insensitive to bulk effects, quantification required significant improvements of the image reconstruction procedure with respect to Compton scatter and attenuation. The experiments were conducted with 22Na and 124I over periods of 100 and 25 days, respectively. From the images we derived trustable anisotropic diffusion coefficients and, in addition, we identified indications of preferential transport zones. We thus demonstrated the unique potential of the PET imaging modality for geoscientific process monitoring under conditions where other methods fail, taking advantage of the extremely high detection sensitivity that is typical of radiotracer applications.

  4. A new mechanism of ionizing radiation detection for positron emission tomography: modulation of optical properties

    NASA Astrophysics Data System (ADS)

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-10-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) annihilation photon pair coincidence time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit of around 100 ps. On the other hand, modulation mechanisms of a material's optical properties as exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to study whether ionizing radiation can also produce fast modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5x10-6 is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the radiation source flux rate and average photon energy.

  5. Identifying active vascular microcalcification by 18F-sodium fluoride positron emission tomography

    PubMed Central

    Irkle, Agnese; Vesey, Alex T.; Lewis, David Y.; Skepper, Jeremy N.; Bird, Joseph L. E.; Dweck, Marc R.; Joshi, Francis R.; Gallagher, Ferdia A.; Warburton, Elizabeth A.; Bennett, Martin R.; Brindle, Kevin M.; Newby, David E.; Rudd, James H.; Davenport, Anthony P.

    2015-01-01

    Vascular calcification is a complex biological process that is a hallmark of atherosclerosis. While macrocalcification confers plaque stability, microcalcification is a key feature of high-risk atheroma and is associated with increased morbidity and mortality. Positron emission tomography and X-ray computed tomography (PET/CT) imaging of atherosclerosis using 18F-sodium fluoride (18F-NaF) has the potential to identify pathologically high-risk nascent microcalcification. However, the precise molecular mechanism of 18F-NaF vascular uptake is still unknown. Here we use electron microscopy, autoradiography, histology and preclinical and clinical PET/CT to analyse 18F-NaF binding. We show that 18F-NaF adsorbs to calcified deposits within plaque with high affinity and is selective and specific. 18F-NaF PET/CT imaging can distinguish between areas of macro- and microcalcification. This is the only currently available clinical imaging platform that can non-invasively detect microcalcification in active unstable atherosclerosis. The use of 18F-NaF may foster new approaches to developing treatments for vascular calcification. PMID:26151378

  6. Quantitation in positron emission computed tomography: 4. Effect of accidental coincidences.

    PubMed

    Hoffman, E J; Huang, S C; Phelps, M E; Kuhl, D E

    1981-06-01

    Accidental coincidences (ACs) and methods of compensation for ACs were investigated in terms of their effect on quantitation in positron emission computed tomography (ECT). Formulations of basic expressions describing the physical factors, which cause true coincidences or ACs, are presented to provide a framework of contrasting the two phenomena. Correction of image data for attenuation of the annihilation radiation or nonuniformities in detector efficiency is shown to amplify errors caused by the presence of ACs in the data. It was shown that failure to compensate for ACs caused overestimates in measurements of isotope concentrations from image data and that in many cases the overestimate was significant for relatively modest percentages of ACs in the data. Three methods of compensation for ACs were evaluated as to their accuracy and effect on statistical noise in images. It was found that nonuniform detector efficiencies could cause prominent image artifacts if an inadequate method was employed in the determination and subtraction of ACs from image data. The additional statistical noise produced in images by subtraction of ACs from total coincidence data demonstrates the advisability of minimizing AC rates in spite of an ability to adequately measure and compensate for their presence in the data.

  7. Design of a super fast three-dimensional projection system for positron emission tomography

    SciTech Connect

    Jones, W.F.; Byars, L.G.; Casey, M.E. )

    1990-04-01

    A hardware architecture for rapid three-dimensional (3D) reconstruction is considered for positron emission tomography (PET). For possibly improved PET performance, obliquely oriented lines of response (LOR) are to be collected and properly utilized by one of several experimental 3D reconstruction algorithms. Image signal-to-noise may improve. Septa removal increases the signal by allowing extra LOR collection but also increases the noise due to reduced shielding against out-of-plane events. Primary utility for all LOR collection and 3D reconstruction algorithms may lie with count starved applications. A major obstacle is the time required to compute the 3D reconstruction. Several hours are required even for general purpose computers capable of several million instructions power second. The bulk of the computations for the various reconstruction algorithms are typically in support of forward and back projection. This paper describes a VLSI based architecture which will support forward and back projection for a 3D image and 4096 2D views totaling over 25 million lines of response projected into 0.5 million voxels.

  8. Iterative reconstruction using a Monte Carlo based system transfer matrix for dedicated breast positron emission tomography

    SciTech Connect

    Saha, Krishnendu; Straus, Kenneth J.; Glick, Stephen J.; Chen, Yu.

    2014-08-28

    To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction.

  9. Positron emission tomography (PET) studies of dopaminergic/cholinergic interactions in the baboon brain

    SciTech Connect

    Dewey, S.L.; Brodie, J.D.; Fowler, J.S.; MacGregor, R.R.; Schlyer, D.J.; King, P.T.; Alexoff, D.L.; Volkow, N.D.; Shiue, C.Y.; Wolf, A.P. )

    1990-01-01

    Interactions between the dopaminergic D2 receptor system and the muscarinic cholinergic system in the corpus striatum of adult female baboons (Papio anubis) were examined using positron emission tomography (PET) combined with (18F)N-methylspiroperidol (( 18F)NMSP) (to probe D2 receptor availability) and (N-11C-methyl)benztropine (to probe muscarinic cholinergic receptor availability). Pretreatment with benztropine, a long-lasting anticholinergic drug, bilaterally reduced the incorporation of radioactivity in the corpus striatum but did not alter that observed in the cerebellum or the rate of metabolism of (18F)NMSP in plasma. Pretreatment with unlabelled NMSP, a potent dopaminergic antagonist, reduced the incorporation of (N-11C-methyl)benztropine in all brain regions, with the greatest effect being in the corpus striatum greater than cortex greater than thalamus greater than cerebellum, but did not alter the rate of metabolism of the labelled benztropine in the plasma. These reductions in the incorporation of either (18F)NMSP or (N-11C-methyl)benztropine exceeded the normal variation in tracer incorporation in repeated studies in the same animal. This study demonstrates that PET can be used as a tool for investigating interactions between neurochemically different yet functionally linked neurotransmitters systems in vivo and provides insight into the consequences of multiple pharmacologic administration.

  10. Test-Retest Repeatability of Myocardial Blood Flow Measurements using Rubidium-82 Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Efseaff, Matthew

    Rubidium-82 positron emission tomography (PET) imaging has been proposed for routine myocardial blood flow (MBF) quantification. Few studies have investigated the test-retest repeatability of this method. Same-day repeatability of rest MBF imaging was optimized with a highly automated analysis program using image-derived input functions and a dual spillover correction (SOC). The effects of heterogeneous tracer infusion profiles and subject hemodynamics on test-retest repeatability were investigated at rest and during hyperemic stress. Factors affecting rest MBF repeatability included gender, suspected coronary artery disease, and dual SOC (p < 0.001). The best repeatability coefficient for same-day rest MBF was 0.20 mL/min/g using a six-minute scan-time, iterative reconstruction, dual SOC, resting rate-pressure-product (RPP) adjustment, and a left atrium image-derived input function. The serial study repeatabilities of the optimized protocol in subjects with homogeneous RPPs and tracer infusion profiles was 0.19 and 0.53 mL/min/g at rest and stress, and 0.95 for stress / rest myocardial flow reserve (MFR). Subjects with heterogeneous tracer infusion profiles and hemodynamic conditions had significantly less repeatable MBF measurements at rest, stress, and stress/rest flow reserve (p < 0.05).

  11. A behavioral and micro positron emission tomography imaging study in a rat model of hypothyroidism.

    PubMed

    Yu, Jing; Tang, Yi-Yuang; Feng, Hong-Bo; Cheng, Xiao-Xin

    2014-09-01

    Hypothyroidism leads to somatic, neuropsychological, and psychiatric changes that are similar to depression. The mechanisms underlying the behavioral abnormalities in adult onset hypothyroidism remain ambiguous. Hypothyroidism was induced in adult male Wistar rats by the maintenance of 0.05% propylthiouracil (PTU) in drinking water for 5 weeks (hypothyroid group; HP group); control rats (CON group) received an equivalent amount of water. The open field and sucrose preference tests were employed, and the link between behavioral changes and brain glucose metabolism was evaluated using micro positron emission tomography imaging. The open field test revealed slightly decreased locomotor activity and significantly reduced rearing and defecation in the hypothyroid group. Hypothyroid rats were also characterized by decreased body weight, sucrose preference, and relative sucrose intake compared to control rats. Hypothyroidism induced reduced brain glucose metabolism in the bilateral motor cortex, the caudate putamen, the cortex cingulate, the nucleus accumbens, and the frontal association cortex. A decreased sucrose preference was positively correlated with metabolic glucose changes in the caudate putamen and the nucleus accumbens. The results indicate that the activity pattern in adult onset hypothyroidism is different from the activity pattern when hypothyroidism is induced in the developmental period of the central nervous system. Decreased sucrose preference in hypothyroid rats may be attributed to anhedonia. Furthermore, these findings suggest there may be a common mechanism underlying adult onset hypothyroidism and depression.

  12. Positron emission tomography in the diagnostic work-up of screening-detected lung nodules.

    PubMed

    Veronesi, Giulia; Travaini, Laura L; Maisonneuve, Patrick; Rampinelli, Cristiano; Bertolotti, Raffaella; Spaggiari, Lorenzo; Bellomi, Massimo; Paganelli, Giovanni

    2015-02-01

    Low-dose computed tomography (CT) screening for lung cancer can reduce lung cancer mortality, but overdiagnosis, false positives and invasive procedures for benign nodules are worrying. We evaluated the utility of positron emission tomography (PET)-CT in characterising indeterminate screening-detected lung nodules. 383 nodules, examined by PET-CT over the first 6 years of the COSMOS (Continuous Observation of Smoking Subjects) study to diagnose primary lung cancer, were reviewed and compared with pathological findings (surgically-treated patients) or follow-up (negative CT for ⩾2 years, considered negative); 196 nodules were malignant. The sensitivity, specificity and accuracy of PET-CT for differentially diagnosing malignant nodules were, respectively, 64%, 89% and 76% overall, and 82%, 92% and 88% for baseline-detected nodules. Performance was lower for nodules found at repeat annual scans, with sensitivity ranging from 22% for nonsolid to 79% for solid nodules (p=0.0001). Sensitivity (87%) and specificity (73%) were high for nodules ⩾15 mm, better (sensitivity 98%) for solid nodules ⩾15 mm. PET-CT was highly sensitive for the differential diagnosis of indeterminate nodules detected at baseline, nodules ⩾15 mm and solid nodules. Sensitivity was low for sub-solid nodules and nodules discovered after baseline for which other methods, e.g. volume doubling time, should be used.

  13. A promising new mechanism of ionizing radiation detection for positron emission tomography: modulation of optical properties

    NASA Astrophysics Data System (ADS)

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2016-11-01

    Using conventional scintillation detection, the fundamental limit in positron emission tomography (PET) time resolution is strongly dependent on the inherent temporal variances generated during the scintillation process, yielding an intrinsic physical limit for the coincidence time resolution of around 100 ps. On the other hand, modulation mechanisms of the optical properties of a material exploited in the optical telecommunications industry can be orders of magnitude faster. In this paper we borrow from the concept of optics pump-probe measurement to for the first time study whether ionizing radiation can produce modulations of optical properties, which can be utilized as a novel method for radiation detection. We show that a refractive index modulation of approximately 5× {{10}-6} is induced by interactions in a cadmium telluride (CdTe) crystal from a 511 keV photon source. Furthermore, using additional radionuclide sources, we show that the amplitude of the optical modulation signal varies linearly with both the detected event rate and average photon energy of the radiation source.

  14. Positron emission tomography imaging of tau pathology in progressive supranuclear palsy.

    PubMed

    Coakeley, Sarah; Cho, Sang Soo; Koshimori, Yuko; Rusjan, Pablo; Harris, Madeleine; Ghadery, Christine; Kim, Jinhee; Lang, Anthony E; Wilson, Alan; Houle, Sylvain; Strafella, Antonio P

    2016-01-01

    Progressive supranuclear palsy is a rare form of atypical Parkinsonism that differs neuropathologically from other parkinsonian disorders. While many parkinsonian disorders such as Parkinson's disease, Lewy body dementia, and multiple system atrophy are classified as synucleinopathies, progressive supranuclear palsy is coined a tauopathy due to the aggregation of pathological tau in the brain. [(18)F]AV-1451 (also known as [(18)F]-T807) is a positron emission tomography radiotracer that binds to paired helical filaments of tau in Alzheimer's disease. We investigated whether [(18)F]AV-1451 could be used as biomarker for the diagnosis and disease progression monitoring in progressive supranuclear palsy. Six progressive supranuclear palsy, six Parkinson's disease, and 10 age-matched healthy controls were recruited. An anatomical MRI and a 90-min PET scan, using [(18)F]AV-1451, were acquired from all participants. The standardized uptake value ratio from 60 to 90 min post-injection was calculated in each region of interest, using the cerebellar cortex as a reference region. No significant differences in standardized uptake value ratios were detected in our progressive supranuclear palsy group compared to the two control groups. [(18)F]AV-1451 may bind selectivity to the paired helical filaments in Alzheimer's disease, which differ from the straight conformation of tau filaments in progressive supranuclear palsy.

  15. Positron Emission Tomography Imaging of Tumor Cell Metabolism and Application to Therapy Response Monitoring

    PubMed Central

    Challapalli, Amarnath; Aboagye, Eric O.

    2016-01-01

    Cancer cells do reprogram their energy metabolism to enable several functions, such as generation of biomass including membrane biosynthesis, and overcoming bioenergetic and redox stress. In this article, we review both established and evolving radioprobes developed in association with positron emission tomography (PET) to detect tumor cell metabolism and effect of treatment. Measurement of enhanced tumor cell glycolysis using 2-deoxy-2-[18F]fluoro-D-glucose is well established in the clinic. Analogs of choline, including [11C]choline and various fluorinated derivatives are being tested in several cancer types clinically with PET. In addition to these, there is an evolving array of metabolic tracers for measuring intracellular transport of glutamine and other amino acids or for measuring glycogenesis, as well as probes used as surrogates for fatty acid synthesis or precursors for fatty acid oxidation. In addition to providing us with opportunities for examining the complex regulation of reprogramed energy metabolism in living subjects, the PET methods open up opportunities for monitoring pharmacological activity of new therapies that directly or indirectly inhibit tumor cell metabolism. PMID:26973812

  16. Cognitive processes and cerebral cortical fundi: findings from positron-emission tomography studies.

    PubMed

    Markowitsch, H J; Tulving, E

    1994-10-25

    Positron-emission tomography (PET) studies of regional cerebral blood flow have provided evidence relevant to localization of cognitive functions. The critical loci identified in these studies are typically described in terms of macroanatomically labeled cortical and subcortical regions. We report the results of a meta-analysis of localization of changes in blood flow, based on nearly 1000 cerebral cortical peaks of activity obtained from groups of subjects in 30 PET studies. The results showed that, on average, 47% of these peaks were localized within the fundus regions of cortical sulci. This is an unexpectedly high proportion because fundal regions compose < 8% of the cortical mantle. Further analysis suggested a coarse correlation between the extent of fundal activation observed in different studies and the estimated cognitive complexity of the tasks used in the studies. These findings are potentially interesting because (i) the preponderance of fundal activation has implications for the interpretation of the PET data, (ii) they suggest that cortical sulcal and fundal regions may play a distinctive role in higher cognitive processing, or (iii) both of the above.

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

    NASA Astrophysics Data System (ADS)

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

    2009-01-01

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

  18. FPGA-Based Front-End Electronics for Positron Emission Tomography.

    PubMed

    Haselman, Michael; Dewitt, Don; McDougald, Wendy; Lewellen, Thomas K; Miyaoka, Robert; Hauck, Scott

    2009-02-22

    Modern Field Programmable Gate Arrays (FPGAs) are capable of performing complex discrete signal processing algorithms with clock rates above 100MHz. This combined with FPGA's low expense, ease of use, and selected dedicated hardware make them an ideal technology for a data acquisition system for positron emission tomography (PET) scanners. Our laboratory is producing a high-resolution, small-animal PET scanner that utilizes FPGAs as the core of the front-end electronics. For this next generation scanner, functions that are typically performed in dedicated circuits, or offline, are being migrated to the FPGA. This will not only simplify the electronics, but the features of modern FPGAs can be utilizes to add significant signal processing power to produce higher resolution images. In this paper two such processes, sub-clock rate pulse timing and event localization, will be discussed in detail. We show that timing performed in the FPGA can achieve a resolution that is suitable for small-animal scanners, and will outperform the analog version given a low enough sampling period for the ADC. We will also show that the position of events in the scanner can be determined in real time using a statistical positioning based algorithm.

  19. Development of analog solid-state photo-detectors for Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Bisogni, Maria Giuseppina; Morrocchi, Matteo

    2016-02-01

    Solid-state photo-detectors are one of the main innovations of past century in the field of sensors. First produced in the early forties with the invention of the p-n junction in silicon and the study of its optical properties, photo-detectors received a major boost in the sixties when the p-i-n (PIN) photodiode was developed and successfully used in several applications. The development of devices with internal gain, avalanche photodiodes (APD) first and then Geiger-mode avalanche photodiodes, named single photon avalanche diode (SPAD), leads to a substantial improvement in sensitivity and allowed single photon detection. Later on, thousands of SPADs have been assembled in arrays of few millimeters squared (named SiPM, silicon photo-multiplier) with single photon resolution. The high internal gain of SiPMs, together with other features peculiar of the silicon technology like compactness, speed and compatibility with magnetic fields, promoted SiPMs as the principal photo-detector competitor of photomultipliers in many applications from radiation detection to medical imaging. This paper provides a review of the properties of analog solid-state photo-detectors. Particular emphasis is given to latest advances on Positron Emission Tomography instrumentation boosted by the adoption of the silicon photo-detectors as an alternative to photomultiplier tubes (PMTs). Special attention is dedicated to the SiPMs, which are playing a key role in the development of innovative scanners.

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

    PubMed

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

    2009-01-01

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

  1. Positron Emission Tomography (PET) Quantification of GABAA Receptors in the Brain of Fragile X Patients.

    PubMed

    D'Hulst, Charlotte; Heulens, Inge; Van der Aa, Nathalie; Goffin, Karolien; Koole, Michel; Porke, Kathleen; Van De Velde, Marc; Rooms, Liesbeth; Van Paesschen, Wim; Van Esch, Hilde; Van Laere, Koen; Kooy, R Frank

    2015-01-01

    Over the last several years, evidence has accumulated that the GABAA receptor is compromised in animal models for fragile X syndrome (FXS), a common hereditary form of intellectual disability. In mouse and fly models, agonists of the GABAA receptor were able to rescue specific consequences of the fragile X mutation. Here, we imaged and quantified GABAA receptors in vivo in brain of fragile X patients using Positron Emission Topography (PET) and [11C]flumazenil, a known high-affinity and specific ligand for the benzodiazepine site of GABAA receptors. We measured regional GABAA receptor availability in 10 fragile X patients and 10 control subjects. We found a significant reduction of on average 10% in GABAA receptor binding potential throughout the brain in fragile X patients. In the thalamus, the brain region showing the largest difference, the GABAA receptor availability was even reduced with 17%. This is one of the first reports of a PET study of human fragile X brain and directly demonstrates that the GABAA receptor availability is reduced in fragile X patients. The study reinforces previous hypotheses that the GABAA receptor is a potential target for rational pharmacological treatment of fragile X syndrome.

  2. Clinical applications of positron emission tomography/computed tomography treatment planning.

    PubMed

    Macapinlac, Homer A

    2008-03-01

    Positron emission tomography/computed tomography (PET/CT) has provided an incremental dimension to the management of cancer patients by allowing the incorporation of important molecular images in radiotherapy treatment planning, ie, direct evaluation of tumor metabolism, cell proliferation, apoptosis, hypoxia, and angiogenesis. The CT component allows 4D imaging techniques, allowing improvements in the accuracy of treatment delivery by compensating for tumor/normal organ motion, improving PET quantification, and correcting PET and CT image misregistration. The combination of PET and CT in a single imaging system to obtain a fused anatomical and functional image data is now emerging as a promising tool in radiotherapy departments for improved delineation of tumor volumes and optimization of treatment plans. PET has the potential to improve radiotherapy planning by minimizing unnecessary irradiation of normal tissues and by reducing the risk of geographic miss. PET influences treatment planning in a high proportion of cases and therefore radiotherapy dose escalation without PET may be futile. This article examines the increasing role of hybrid PET/CT imaging techniques in process of improving treatment planning in oncology with emphasis on non small cell lung cancer.

  3. A fast rebinning algorithm for 3D positron emission tomography using John's equation

    NASA Astrophysics Data System (ADS)

    Defrise, Michel; Liu, Xuan

    1999-08-01

    Volume imaging in positron emission tomography (PET) requires the inversion of the three-dimensional (3D) x-ray transform. The usual solution to this problem is based on 3D filtered-backprojection (FBP), but is slow. Alternative methods have been proposed which factor the 3D data into independent 2D data sets corresponding to the 2D Radon transforms of a stack of parallel slices. Each slice is then reconstructed using 2D FBP. These so-called rebinning methods are numerically efficient but are approximate. In this paper a new exact rebinning method is derived by exploiting the fact that the 3D x-ray transform of a function is the solution to the second-order partial differential equation first studied by John. The method is proposed for two sampling schemes, one corresponding to a pair of infinite plane detectors and another one corresponding to a cylindrical multi-ring PET scanner. The new FORE-J algorithm has been implemented for this latter geometry and was compared with the approximate Fourier rebinning algorithm FORE and with another exact rebinning algorithm, FOREX. Results with simulated data demonstrate a significant improvement in accuracy compared to FORE, while the reconstruction time is doubled. Compared to FOREX, the FORE-J algorithm is slightly less accurate but more than three times faster.

  4. The value of positron emission tomography scanning in the detection of subclinical metastatic melanoma.

    PubMed

    Acland, K M; O'Doherty, M J; Russell-Jones, R

    2000-04-01

    We have undertaken a retrospective analysis of all positron emission tomography (PET) scans carried out at St Thomas' Hospital, London, since 1994 to establish the sensitivity and specificity of this radiologic technique in cutaneous malignant melanoma. In particular, we have identified those patients with primary cutaneous malignant melanoma in whom PET scanning revealed in-transit or regional spread to nodes and those patients with known regional spread in whom PET scanning revealed distant metastases. We defined our false-negative results as a negative scan result with positive histology or subsequent clinical progression of disease. False-positive results were defined as a suspect scan with negative histology or no subsequent progression of disease. PET scanning had an overall sensitivity of 78% and specificity of 87%; however, subset analysis (M. D. Anderson staging system) showed a sensitivity of 50% for stage I disease (34 patients and 35 scans) and 33% for stage II disease (9 patients and 9 scans) with specificities of 87% and 100%, respectively. For stage III disease (16 patients and 17 scans), PET showed a sensitivity of 93% and specificity of 50%. Overall, 35% of patients with true-positive scans had their disease restaged. We can conclude therefore that PET is valuable as a staging procedure in patients with known regional spread but is suboptimal in the prediction of outcome in stage I or stage II disease.

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

    PubMed

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

    2017-01-01

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

  6. Binocular disparity discrimination in human cerebral cortex: functional anatomy by positron emission tomography.

    PubMed Central

    Gulyás, B; Roland, P E

    1994-01-01

    Neurobiological studies in higher primates indicate that the processing of stereoscopic information takes place at early levels in the visual cortex. To map the anatomical structures in the human brain participating in pure stereopsis based upon binocular disparity, we measured with positron emission tomography the changes in regional cerebral blood flow as an indicator of metabolic activity in 10 healthy young men during visual discrimination of binocular disparity. The data demonstrate that the discrimination of pure stereo-optic disparity information takes place in the polar striate cortex and the neighboring peri-striate cortices, as well as in the parietal lobe, the prefrontal cortex, and the cerebellum. The discrimination of stereoscopic depth is dependent on a network composed of multiple functional fields localized in occipital- and parietal-lobe visual areas as well as in the dorsolateral and mesial prefrontal cortex. The findings support the importance of coactivated occipitoparietal visual areas in the processing and analysis of binocular depth information in humans. Images PMID:8108394

  7. Modelling human drug abuse and addiction with dedicated small animal positron emission tomography.

    PubMed

    Dalley, Jeffrey W; Fryer, Tim D; Aigbirhio, Franklin I; Brichard, Laurent; Richards, Hugh K; Hong, Young T; Baron, Jean-Claude; Everitt, Barry J; Robbins, Trevor W

    2009-01-01

    Drug addiction is a chronically relapsing brain disorder, which causes substantial harm to the addicted individual and society as a whole. Despite considerable research we still do not understand why some people appear particularly disposed to drug abuse and addiction, nor do we understand how frequently co-morbid brain disorders such as depression and attention-deficit hyperactivity disorder (ADHD) contribute causally to the emergence of addiction-like behaviour. In recent years positron emission tomography (PET) has come of age as a translational neuroimaging technique in the study of drug addiction, ADHD and other psychopathological states in humans. PET provides unparalleled quantitative assessment of the spatial distribution of radiolabelled molecules in the brain and because it is non-invasive permits longitudinal assessment of physiological parameters such as binding potential in the same subject over extended periods of time. However, whilst there are a burgeoning number of human PET experiments in ADHD and drug addiction there is presently a paucity of PET imaging studies in animals despite enormous advances in our understanding of the neurobiology of these disorders based on sophisticated animal models. This article highlights recent examples of successful cross-species convergence of findings from PET studies in the context of drug addiction and ADHD and identifies how small animal PET can more effectively be used to model complex psychiatric disorders involving at their core impaired behavioural self-control.

  8. Positron emission tomography to assess hypoxia and perfusion in lung cancer

    PubMed Central

    Verwer, Eline E; Boellaard, Ronald; van der Veldt, Astrid AM

    2014-01-01

    In lung cancer, tumor hypoxia is a characteristic feature, which is associated with a poor prognosis and resistance to both radiation therapy and chemotherapy. As the development of tumor hypoxia is associated with decreased perfusion, perfusion measurements provide more insight into the relation between hypoxia and perfusion in malignant tumors. Positron emission tomography (PET) is a highly sensitive nuclear imaging technique that is suited for non-invasive in vivo monitoring of dynamic processes including hypoxia and its associated parameter perfusion. The PET technique enables quantitative assessment of hypoxia and perfusion in tumors. To this end, consecutive PET scans can be performed in one scan session. Using different hypoxia tracers, PET imaging may provide insight into the prognostic significance of hypoxia and perfusion in lung cancer. In addition, PET studies may play an important role in various stages of personalized medicine, as these may help to select patients for specific treatments including radiation therapy, hypoxia modifying therapies, and antiangiogenic strategies. In addition, specific PET tracers can be applied for monitoring therapy. The present review provides an overview of the clinical applications of PET to measure hypoxia and perfusion in lung cancer. Available PET tracers and their characteristics as well as the applications of combined hypoxia and perfusion PET imaging are discussed. PMID:25493221

  9. Magnetic resonance imaging and positron emission tomography in the diagnosis of neurodegenerative dementias

    PubMed Central

    Del Sole, Angelo; Malaspina, Simona; Biasina, Alberto Magenta

    2016-01-01

    Summary Neuroimaging, both with magnetic resonance imaging (MRI) and positron emission tomography (PET), has gained a pivotal role in the diagnosis of primary neurodegenerative diseases. These two techniques are used as biomarkers of both pathology and progression of Alzheimer’s disease (AD) and to differentiate AD from other neurodegenerative diseases. MRI is able to identify structural changes including patterns of atrophy characterizing neurodegenerative diseases, and to distinguish these from other causes of cognitive impairment, e.g. infarcts, space-occupying lesions and hydrocephalus. PET is widely used to identify regional patterns of glucose utilization, since distinct patterns of distribution of cerebral glucose metabolism are related to different subtypes of neurodegenerative dementia. The use of PET in mild cognitive impairment, though controversial, is deemed helpful for predicting conversion to dementia and the dementia clinical subtype. Recently, new radiopharmaceuticals for the in vivo imaging of amyloid burden have been licensed and more tracers are being developed for the assessment of tauopathies and inflammatory processes, which may underlie the onset of the amyloid cascade. At present, the cerebral amyloid burden, imaged with PET, may help to exclude the presence of AD as well as forecast its possible onset. Finally PET imaging may be particularly useful in ongoing clinical trials for the development of dementia treatments. In the near future, the use of the above methods, in accordance with specific guidelines, along with the use of effective treatments will likely lead to more timely and successful treatment of neurodegenerative dementias. PMID:28072381

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

    PubMed

    Bian, Zhaoying; Huang, Jing; Ma, Jianhua; Lu, Lijun; Niu, Shanzhou; Zeng, Dong; Feng, Qianjin; Chen, Wufan

    2014-01-01

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

  11. Positron emission tomographic scan investigations of Huntington's disease: cerebral metabolic correlates of cognitive function

    SciTech Connect

    Berent, S.; Giordani, B.; Lehtinen, S.; Markel, D.; Penney, J.B.; Buchtel, H.A.; Starosta-Rubinstein, S.; Hichwa, R.; Young, A.B.

    1988-06-01

    Fifteen drug-free patients with early to mid-stage Huntington's disease (HD) were evaluated with positron emission tomographic (PET) scans of /sup 18/F-2-fluoro-2-deoxy-D-glucose uptake and quantitative measures of neurological function, learning, memory, and general intelligence. In comparison with a group of normal volunteers, the HD patients showed lower metabolism in both caudate (p less than 0.001) and putamen (p less than 0.001) on PET scans. A significant and positive relationship was found between neuropsychological measures of verbal learning and memory and caudate metabolism in the patient group but not in the normal group. Visual-spatial learning did not reflect a similar pattern, but performance intelligence quotient was positively related to both caudate and putamen metabolism in the HD group. Vocabulary level was unrelated to either brain structure. Discussion focuses on these and other observed brain-behavior relationships and on the implications of these findings for general behaviors such as those involved in coping and adaptation.

  12. Evoked Potentials and Neuropsychological Tests Validate Positron Emission Topography (PET) Brain Metabolism in Cognitively Impaired Patients

    PubMed Central

    Braverman, Eric R.; Blum, Kenneth; Damle, Uma J.; Kerner, Mallory; Dushaj, Kristina; Oscar-Berman, Marlene

    2013-01-01

    Fluorodeoxyglucose (FDG) Positron Emission Topography (PET) brain hypometabolism (HM) correlates with diminished cognitive capacity and risk of developing dementia. However, because clinical utility of PET is limited by cost, we sought to determine whether a less costly electrophysiological measure, the P300 evoked potential, in combination with neuropsychological test performance, would validate PET HM in neuropsychiatric patients. We found that patients with amnestic and non-amnestic cognitive impairment and HM (n = 43) evidenced significantly reduced P300 amplitudes, delayed latencies, and neuropsychological deficits, compared to patients with normal brain metabolism (NM; n = 187). Data from patients with missing cognitive test scores (n = 57) were removed from the final sample, and logistic regression modeling was performed on the modified sample (n = 173, p = .000004). The logistic regression modeling, based on P300 and neuropsychological measures, was used to validate membership in the HM vs. NM groups. It showed classification validation in 13/25 HM subjects (52.0%) and in 125/148 NM subjects (84.5%), correlating with total classification accuracy of 79.8%. In this paper, abnormal P300 evoked potentials coupled with cognitive test impairment validates brain metabolism and mild/moderate cognitive impairment (MCI). To this end, we cautiously propose incorporating electrophysiological and neuropsychological assessments as cost-effective brain metabolism and MCI indicators in primary care. Final interpretation of these results must await required additional studies confirming these interesting results. PMID:23526928

  13. Metabolizer in vivo of fullerenes and metallofullerenes by positron emission tomography

    NASA Astrophysics Data System (ADS)

    Li, Juan; Yang, Wenjiang; Cui, Rongli; Wang, Dongliang; Chang, Yanan; Gu, Weihong; Yin, Wenyan; Bai, Xue; Chen, Kui; Xia, Lin; Geng, Huan; Xing, Gengmei

    2016-04-01

    Fullerenes (C60) and metallofullerenes (Gd@C82) have similar chemical structure, but the bio-effects of both fullerene-based materials are distinct in vivo. Tracking organic carbon-based materials such as C60 and Gd@C82 is difficult in vivo due to the high content of carbon element in the living tissues themselves. In this study, the biodistribution and metabolism of fullerenes (C60 and Gd@C82) radiolabeled with 64Cu were observed by positron emission tomography (PET). 64Cu-C60 and 64Cu-Gd@C82 were prepared using 1, 4, 7, 10-tetrakis (carbamoylmethyl)-1, 4, 7, 10-tetra-azacyclodo-decanes grafted on carbon cages as a chelator for 64Cu, and were obtained rapidly with high radiochemical yield (≥90%). The new radio-conjugates were evaluated in vivo in the normal mouse model and tissue distribution by small animal PET/CT imaging and histology was carried out. The PET imaging, the biodistribution and the excretion of C60 and Gd@C82 indicated that C60 samples have higher blood retention and lower renal clearance than the Gd@C82 samples in vivo and suggested that the differences in metabolism and distribution in vivo were caused by the structural differences of the groups on the fullerene cages though there is chemical similarity between C60 and Gd@C82.

  14. Assessment of Cancer-Associated Biomarkers by Positron Emission Tomography: Advances and Challenges

    PubMed Central

    Collier, T. Lee; Lecomte, Roger; McCarthy, Timothy J.; Meikle, Steve; Ruth, Thomas J.; Scopinaro, Francesco; Signore, Alberto; Van Brocklin, Henry; Van de Wiele, Christophe; Waterhouse, Rikki N.

    2002-01-01

    Positron emission tomography (PET) provides a powerful means to non-invasively image and quantify protein expression and biochemical changes in living subjects at nano- and picomolar levels. As the field of molecular imaging develops, and as advances in the biochemistry, pharmacology, therapeutics, and molecular biology of disease are made, there is a corresponding increase in the number of clinically relevant, novel disease-associated biomarkers that are brought to the attention of those developing imaging probes for PET. In addition, due to the high specificity of the PET radiotracers being developed, there is a demand for PET cameras with higher sensitivity and resolution. This manuscript reviews advances over the past five years in clinical and pre-clinical PET instrumentation and in new PET probes and imaging methods associated with the latest trends in the molecular imaging of cancer. Included in the PET tracer review is a description of new radioligands for steroid receptors, growth factor receptors, receptor tyrosine kinases, sigma receptors, tumor-associated enzymes, gene reporter probes, markers for tumor hypoxia and metabolism, and sites associated with angiogenesis and cellular proliferation. The use of PET imaging in drug development, including the monitoring of cancer chemotherapy, also is discussed. PMID:14646039

  15. Future imaging of atherosclerosis: molecular imaging of coronary atherosclerosis with 18F positron emission tomography

    PubMed Central

    Psaltis, Peter J.

    2016-01-01

    Atherosclerosis is characterized by the formation of complex atheroma lesions (plaques) in arteries that pose risk by their flow-limiting nature and propensity for rupture and thrombotic occlusion. It develops in the context of disturbances to lipid metabolism and immune response, with inflammation underpinning all stages of plaque formation, progression and rupture. As the primary disease process responsible for myocardial infarction, stroke and peripheral vascular disease, atherosclerosis is a leading cause of morbidity and mortality on a global scale. A precise understanding of its pathogenic mechanisms is therefore critically important. Integral to this is the role of vascular wall imaging. Over recent years, the rapidly evolving field of molecular imaging has begun to revolutionize our ability to image beyond just the anatomical substrate of vascular disease, and more dynamically assess its pathobiology. Nuclear imaging by positron emission tomography (PET) can target specific molecular and biological pathways involved in atherosclerosis, with the application of 18Fluoride PET imaging being widely studied for its potential to identify plaques that are vulnerable or high risk. In this review, we discuss the emergence of 18Fluoride PET as a promising modality for the assessment of coronary atherosclerosis, focusing on the strengths and limitations of the two main radionuclide tracers that have been investigated to date: 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) and sodium 18F-fluoride (18F-NaF). PMID:27500093

  16. INSIDE in-beam positron emission tomography system for particle range monitoring in hadrontherapy.

    PubMed

    Bisogni, Maria Giuseppina; Attili, Andrea; Battistoni, Giuseppe; Belcari, Nicola; Camarlinghi, Niccolo'; Cerello, Piergiorgio; Coli, Silvia; Del Guerra, Alberto; Ferrari, Alfredo; Ferrero, Veronica; Fiorina, Elisa; Giraudo, Giuseppe; Kostara, Eleftheria; Morrocchi, Matteo; Pennazio, Francesco; Peroni, Cristiana; Piliero, Maria Antonietta; Pirrone, Giovanni; Rivetti, Angelo; Rolo, Manuel D; Rosso, Valeria; Sala, Paola; Sportelli, Giancarlo; Wheadon, Richard

    2017-01-01

    The quality assurance of particle therapy treatment is a fundamental issue that can be addressed by developing reliable monitoring techniques and indicators of the treatment plan correctness. Among the available imaging techniques, positron emission tomography (PET) has long been investigated and then clinically applied to proton and carbon beams. In 2013, the Innovative Solutions for Dosimetry in Hadrontherapy (INSIDE) collaboration proposed an innovative bimodal imaging concept that combines an in-beam PET scanner with a tracking system for charged particle imaging. This paper presents the general architecture of the INSIDE project but focuses on the in-beam PET scanner that has been designed to reconstruct the particles range with millimetric resolution within a fraction of the dose delivered in a treatment of head and neck tumors. The in-beam PET scanner has been recently installed at the Italian National Center of Oncologic Hadrontherapy (CNAO) in Pavia, Italy, and the commissioning phase has just started. The results of the first beam test with clinical proton beams on phantoms clearly show the capability of the in-beam PET to operate during the irradiation delivery and to reconstruct on-line the beam-induced activity map. The accuracy in the activity distal fall-off determination is millimetric for therapeutic doses.

  17. The role of positron emission tomography in the detection of pancreatic disease

    SciTech Connect

    Syrota, A.; Duquesnoy, N.; Paraf, A.; Kellershohn, C.

    1982-04-01

    Positron emission tomography (PET) was used to assess possible pancreatic disease in 100 patients. Following injection of 10-15 mCi (370-740 MBq) of /sup 11/C-L-methionine, 4-12 transverse sections 2 cm thick were obtained. In 85 patients with a definite diagnosis (45 normal, 9 acute pancreatitis, 18 chronic pancreatitis, and 13 cancer), PET showed a sensitivity of 85.0%, a specificity of 97.8%, and an accuracy of 91.8%, higher than with transmission computed tomography (CT) or ultrasonography, despite relatively low spatial resolution; this can be explained by the fact that exocrine pancreatic function was altered prior to morphological change. In 22 normal subjects, 0.011 +/- 0.003% (mean +/- S.D.) of injected /sup 11/C was found in 1 ml of liver tissue and 0.015 +/- 0.005% in 1 ml of pancreatic tissue; the pancreas-to-liver concentration ratio was 1.3 +/- 0.4. Hepatic /sup 11/C concentration was identical in the four groups of patients. Pancreatic uptake of /sup 11/C-L-methionine was significantly lower in patients with chronic pancreatitis (n = 13) and pancreatic carcinoma (n = 10) (p <0.001); however, it was not possible to distinguish cancer from chronic pancreatitis because the same functional alteration occurred in both.

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

    SciTech Connect

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

    1985-05-01

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

  19. The role of positron emission tomography in the detection of pancreatic disease

    SciTech Connect

    Syrota, A.; Duquesnoy, N.; Paraf, A.; Kellershohn, C.

    1982-04-01

    Positron emission tomography (PET) was used to assess possible pancreatic disease in 100 patients. Following injection of 10-15 mCi (370-740 MBq) of 11C-L-methionine, 4-12 transverse sections 2 cm thick were obtained. In 85 patients with a definite diagnosis (45 normal, 9 acute pancreatitis, 18 chronic pancreatitis, and 13 cancer), PET showed a sensitivity of 85.0%, a specificity of 97.8%, and an accuracy of 91.8%, higher than with transmission computed tomography (CT) or ultrasonography, despite relatively low spatial resolution; this can be explained by the fact that exocrine pancreatic function was altered prior to morphological change. In 22 normal subjects, 0.011 +/- 0.003% (mean +/- S.D). of injected 11C was found in 1 ml of liver tissue and 0.015 +/- 0.005% in 1 ml of pancreatic tissue; the pancreas-to-liver concentration ratio was 1.3 +/- 0.4. Hepatic 11C concentration was identical in the four groups of patients. Pancreatic uptake of 11C-L-methionine was significantly lower in patients with chronic pancreatitis (n . 13) and pancreatic carcinoma (n . 10) (p less than 0.001); however, it was not possible to distinguish cancer from chronic pancreatitis because the same functional alteration occurred in both.

  20. Speech disorders in olivopontocerebellar atrophy correlate with positron emission tomography findings

    SciTech Connect

    Kluin, K.J.; Gilman, S.; Markel, D.S.; Koeppe, R.A.; Rosenthal, G.; Junck, L.

    1988-06-01

    We compared the severity of ataxic and spastic dysarthria with local cerebral metabolic rates for glucose (lCMRGlc) in 30 patients with olivopontocerebellar atrophy (OPCA). Perceptual analysis was used to examine the speech disorders, and rating scales were devised to quantitate the degree of ataxia and spasticity in the speech of each patient. lCMRGlc was measured with /sup 18/F-2-fluoro-2-deoxy-D-glucose and positron emission tomography (PET). PET studies revealed marked hypometabolism in the cerebellar hemispheres, cerebellar vermis, and brainstem of OPCA patients compared with 30 control subjects. With data normalized to the cerebral cortex, a significant inverse correlation was found between the severity of ataxia in speech and the lCMRGlc within the cerebellar vermis, cerebellar hemispheres, and brainstem, but not within the thalamus. No significant correlation was found between the severity of spasticity in speech and lCMRGlc in any of these structures. The findings support the view that the severity of ataxia in speech in OPCA is related to the functional activity of the cerebellum and its connections in the brainstem.

  1. Molecular imaging of neuroinflammation in preclinical rodent models using positron emission tomography.

    PubMed

    Gargiulo, Sara; Coda, Anna R; Panico, Mariarosaria; Gramanzini, Matteo; Moresco, Rosa M; Chalon, Sylvie; Pappatà, Sabina

    2017-03-01

    Neuroinflammation (NI) is an adaptive response to different noxious stimuli, involving microglia, astrocytes and peripheral immune cells. NI is a hallmark of several acute and chronic diseases of central nervous system (CNS) and contributes to both damage and repair of CNS tissue. Interventional or genetically modified rodent models mimicking human neuropathologies may provide valuable insights on basic mechanisms of NI, but also for improving the development of new diagnostic and therapeutic strategies. Preclinical positron emission tomography (PET) allows to investigate noninvasively the inflammatory response in CNS of rodent models at a molecular level, validating innovative probes for early diagnosis, and characterizing the time course of neuroinflammatory changes and their relationship with disease progression, as well as the effects of experimental treatments with high translational potential. In particular, recent efforts of preclinical PET field are intended to develop specific and selective radiotracers that target the activation of innate immune system in CNS. Here, we have reviewed the state of art for PET in relevant rodent models of acute and chronic neuropathologies associated with NI, with particular regard on imaging of activated microglia and astrocytes.

  2. Imaging Multimodalities for Dissecting Alzheimer's Disease: Advanced Technologies of Positron Emission Tomography and Fluorescence Imaging

    PubMed Central

    Shimojo, Masafumi; Higuchi, Makoto; Suhara, Tetsuya; Sahara, Naruhiko

    2015-01-01

    The rapid progress in advanced imaging technologies has expanded our toolbox for monitoring a variety of biological aspects in living subjects including human. In vivo radiological imaging using small chemical tracers, such as with positron emission tomography, represents an especially vital breakthrough in the efforts to improve our understanding of the complicated cascade of neurodegenerative disorders including Alzheimer's disease (AD), and it has provided the most reliable visible biomarkers for enabling clinical diagnosis. At the same time, in combination with genetically modified animal model systems, the most recent innovation of fluorescence imaging is helping establish diverse applications in basic neuroscience research, from single-molecule analysis to animal behavior manipulation, suggesting the potential utility of fluorescence technology for dissecting the detailed molecular-based consequence of AD pathophysiology. In this review, our primary focus is on a current update of PET radiotracers and fluorescence indicators beneficial for understanding the AD cascade, and discussion of the utility and pitfalls of those imaging modalities for future translational research applications. We will also highlight current cutting-edge genetic approaches and discuss how to integrate individual technologies for further potential innovations. PMID:26733795

  3. Positron emission tomography / computerized tomography evaluation of primary Hodgkin's disease of liver.

    PubMed

    Gota, V S; Purandare, N C; Gujral, S; Shah, S; Nair, R; Rangarajan, V

    2009-01-01

    Occurrence of primary Hodgkin's lymphoma (PHL) of the liver is extremely rare. We report on a case of a 60-year-old male who presented with liver mass and B-symptomatology. Hepatoma or hepatic metastasis from a gastrointestinal primary was initially suspected. Tumor markers like AFP, CEA, Total PSA, and CA-19.9 were within normal limits. Positron Emission Tomography / Computerized Tomography (PET/CT) revealed a large hepatic lesion and a nodal mass in the porta hepatis. A liver biopsy was consistent with Hodgkin's lymphoma. There was complete regression of the hepatic lesion and evidence of shrinkage of the nodal mass following four cycles of chemotherapy. 18F Fluro -de-oxy Glucose (FDG) PET / CT in this case helped in establishing a primary hepatic lymphoma by demonstrating the absence of pathologically hypermetabolic foci in any other nodes or organs. PET / CT scan is a useful adjunct to conventional imaging and histopathology, not only to establish the initial diagnosis, but also to monitor treatment response in PHL.

  4. The role of pallidal serotonergic function in Parkinson's disease dyskinesias: a positron emission tomography study.

    PubMed

    Smith, Ruben; Wu, Kit; Hart, Thomas; Loane, Clare; Brooks, David J; Björklund, Anders; Odin, Per; Piccini, Paola; Politis, Marios

    2015-04-01

    We have investigated the role of globus pallidus (GP) serotonergic terminals in the development of levodopa-induced dyskinesias (LIDs) in Parkinson's disease (PD). We studied 12 PD patients without LIDs, 12 PD patients with LIDs, and 12 healthy control subjects. We used (11)C-DASB positron emission tomography (PET), a marker of serotonin transporter availability, and (11)C-raclopride PET to measure changes in synaptic dopamine levels following levodopa administration. PD patients without LIDs showed a significant reduction of GP serotonin transporter binding compared with healthy controls although this was within the normal range in PD patients with LIDs. Levels of GP serotonin transporter binding correlated positively with severity of dyskinesias. (11)C-raclopride PET detected a significant rise in GP synaptic dopamine levels of patients with LIDs after a levodopa challenge but not in patients with a stable response. Our findings indicate that LIDs in PD are associated with higher GP serotonergic function. This increased serotonin function may result in further dysregulation of thalamocortical signals and so promote the expression of dyskinesias.

  5. Mycosis fungoides staged by 18F-flurodeoxyglucose positron emission tomography/computed tomography

    PubMed Central

    Xu, Lu; Pang, Hua; Zhu, Jin; Chen, Xi; Guan, Lili; Wang, Jie; Chen, Jing; Liu, Ying

    2016-01-01

    Abstract Introduction: Mycosis fungoides is a kind of malignant lymphoma arising from T cells, but primarily occurs in skin, and it is the most common type of cutaneous lymphoma. Mycosis fungoides (MF) is a rare non-Hodgkin lymphoma but the most common type of primary cutaneous T-cell lymphomas. Because of unknown etiology and mechanism, and lack of typical clinical and histophysiological manifestations, the final diagnosis of MF is currently dependent on pathology and immunohistochemistry. Subsequently, tumor staging is very important. Different approaches would be taken according to varying degrees of cutaneous and extracutaneous lesions. Computed tomography (CT) scan has been chosen to stage tumors customarily. However, CT could only provide morphological information and analyze lymphadenopathy by the size criteria. 18F-flurodeoxyglucose positron emission tomography/computed tomography (PET/CT) could provide morphological information and metabolic conditions simultaneously, which is helpful to locate and stage lesion. Conclusion: 18F-flurodeoxyglucose PET/CT could identify cutaneous and extracutaneous lesions in patients with MF. It could provide the range of lesions and biopsy target. PMID:27828842

  6. Low background high efficiency radiocesium detection system based on positron emission tomography technology

    SciTech Connect

    Yamamoto, Seiichi; Ogata, Yoshimune

    2013-09-15

    After the 2011 nuclear power plant accident at Fukushima, radiocesium contamination in food became a serious concern in Japan. However, low background and high efficiency radiocesium detectors are expensive and huge, including semiconductor germanium detectors. To solve this problem, we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because {sup 134}Cs emits two gamma photons (795 and 605 keV) within 5 ps, they can selectively be measured with coincidence. Such major environmental gamma photons as {sup 40}K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi{sub 4}Ge{sub 3}O{sub 12} (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence, we eliminated most single gamma photons from the energy distribution and only detected those from {sup 134}Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

  7. Preclinical positron emission tomography scanner based on a monolithic annulus of scintillator: initial design study.

    PubMed

    Stolin, Alexander V; Martone, Peter F; Jaliparthi, Gangadhar; Raylman, Raymond R

    2017-01-01

    Positron emission tomography (PET) scanners designed for imaging of small animals have transformed translational research by reducing the necessity to invasively monitor physiology and disease progression. Virtually all of these scanners are based on the use of pixelated detector modules arranged in rings. This design, while generally successful, has some limitations. Specifically, use of discrete detector modules to construct PET scanners reduces detection sensitivity and can introduce artifacts in reconstructed images, requiring the use of correction methods. To address these challenges, and facilitate measurement of photon depth-of-interaction in the detector, we investigated a small animal PET scanner (called AnnPET) based on a monolithic annulus of scintillator. The scanner was created by placing 12 flat facets around the outer surface of the scintillator to accommodate placement of silicon photomultiplier arrays. Its performance characteristics were explored using Monte Carlo simulations and sections of the NEMA NU4-2008 protocol. Results from this study revealed that AnnPET's reconstructed spatial resolution is predicted to be [Formula: see text] full width at half maximum in the radial, tangential, and axial directions. Peak detection sensitivity is predicted to be 10.1%. Images of simulated phantoms (mini-hot rod and mouse whole body) yielded promising results, indicating the potential of this system for enhancing PET imaging of small animals.

  8. Cerebral hypometabolism in progressive supranuclear palsy studied with positron emission tomography

    SciTech Connect

    Foster, N.L.; Gilman, S.; Berent, S.; Morin, E.M.; Brown, M.B.; Koeppe, R.A.

    1988-09-01

    Progressive supranuclear palsy (PSP) is characterized by supranuclear palsy of gaze, axial dystonia, bradykinesia, rigidity, and a progressive dementia. Pathological changes in this disorder are generally restricted to subcortical structures, yet the type and range of cognitive deficits suggest the involvement of many cerebral regions. We examined the extent of functional impairment to cerebral cortical and subcortical structures as measured by the level of glucose metabolic activity at rest. Fourteen patients with PSP were compared to 21 normal volunteers of similar age using 18F-2-fluoro-2-deoxy-D-glucose and positron emission tomography. Glucose metabolism was reduced in the caudate nucleus, putamen, thalamus, pons, and cerebral cortex, but not in the cerebellum in the patients with PSP as compared to the normal subjects. Analysis of individual brain regions revealed significant declines in cerebral glucose utilization in most regions throughout the cerebral cortex, particularly those in the superior half of the frontal lobe. Declines in the most affected regions of cerebral cortex were greater than those in any single subcortical structure. Although using conventional neuropathological techniques the cerebral cortex appears to be unaffected in PSP, significant and pervasive functional impairments in both cortical and subcortical structures are present. These observations help to account for the constellation of cognitive symptoms in individual patients with PSP and the difficulty encountered in identifying a characteristic psychometric profile for this group of patients.

  9. Positron emission tomography--examination of chemical transmission in the living human brain. Development of radioligands.

    PubMed

    Farde, L; Hall, H

    1992-02-01

    The imaging technique Positron Emission Tomography (PET) allows examination of chemical neurotransmission in brain. Of key importance for PET-research on neuroreceptors is the development of suitable radiolabelled tracers (ligands). This paper illustrates the multidisciplinary research activities necessary for ligand development. The selective D1- and D2-dopamine receptor antagonists SCH 23390 and raclopride (CAS 84225-95-6), respectively, were labelled with [3H] and characterized in biochemical studies in vitro on human brain homogenates and in autoradiographic studies on cryosections from human hemispheres. The experimental information was used to interpret and support the PET-findings with [11C]-labelled SCH 23390 and raclopride in vivo in humans. In conclusion, these ligands can be used to quantitatively examine dopamine receptors in the human basal ganglia in vivo. An applied study for PET-determination of D1- and D2-dopamine receptor occupancy during antipsychotic drug treatment indicates that the D2-dopamine receptor and possibly also the D1-dopamine receptor are targets for neuroleptic drug action.

  10. In vivo measurement of dopamine receptors in pituitary adenomas using positron emission tomography.

    PubMed

    Muhr, C; Bergström, M; Lundberg, P O; Bergström, K; Långström, B

    1986-01-01

    Patients with pituitary adenomas were examined with positron emission tomography (PET) with the administration of the 11C-labelled dopamine-D2 antagonists N-methylspiperone and raclopride. The studies were repeated after protection of the D2-receptors with Haloperidol to enable a separation of specific and unspecific receptor binding. The receptor binding was evaluated by visual inspection and with the application of a kinetic model. The results showed marked specific dopamine-D2 receptor binding in the prolactinomas and minimal or no such binding in the hormonally inactive adenomas. The two tracers 11C-raclopride and 11C-N-methylspiperone showed qualitatively the same result although raclopride resulted in a higher tumor to normal brain ratio. In conclusion, PET is a valuable complement to other radiologic techniques like computed tomography and magnetic resonance imaging in the evaluation of pituitary adenomas. An assessment of the dopamine-D2 receptors in the adenomas has a direct influence on the choice of treatment because adenomas with high amounts of receptors are in most cases effectively treated with dopamine agonists like bromocriptine.

  11. A New Positron Emission Tomography (PET) Radioligand for Imaging Sigma-1 Receptors in Living Subjects

    PubMed Central

    Zavaleta, Cristina L.; Nielsen, Carsten H.; Mesangeau, Christophe; Vuppala, Pradeep K.; Chan, Carmel; Avery, Bonnie A.; Fishback, James A.; Matsumoto, Rae R.; Gambhir, Sanjiv S.; McCurdy, Christopher R.; Chin, Frederick T.

    2014-01-01

    Sigma-1 receptor (S1R) radioligands have the potential to detect and monitor various neurological diseases. Herein we report the synthesis, radiofluorination and evaluation of a new S1R ligand 6-(3-fluoropropyl)-3-(2-(azepan-1-yl)ethyl)benzo[d]thiazol-2(3H)-one ([18F]FTC-146, [18F]13). [18F]13 was synthesized by nucleophilic fluorination, affording a product with >99% radiochemical purity (RCP) and specific activity (SA) of 2.6 ± 1.2 Ci/Amol (n = 13) at end of synthesis (EOS). Positron emission tomography (PET) and ex vivo autoradiography studies of [18F]13 in mice showed high uptake of the radioligand in S1R rich regions of the brain. Pre treatment with 1 mg/kg haloperidol (2), non radioactive 13, or BD1047 (18) reduced the binding of [18F]13 in the brain at 60 min by 80%, 82% and 81% respectively, suggesting that [18F]13 accumulation in mouse brain represents specific binding to S1Rs. These results indicate that [18F]13 is a promising candidate radiotracer for further evaluation as a tool for studying S1Rs in living subjects. PMID:22853801

  12. Caged [(18)F]FDG Glycosylamines for Imaging Acidic Tumor Microenvironments Using Positron Emission Tomography.

    PubMed

    Flavell, Robert R; Truillet, Charles; Regan, Melanie K; Ganguly, Tanushree; Blecha, Joseph E; Kurhanewicz, John; VanBrocklin, Henry F; Keshari, Kayvan R; Chang, Christopher J; Evans, Michael J; Wilson, David M

    2016-01-20

    Solid tumors are hypoxic with altered metabolism, resulting in secretion of acids into the extracellular matrix and lower relative pH, a feature associated with local invasion and metastasis. Therapeutic and diagnostic agents responsive to this microenvironment may improve tumor-specific delivery. Therefore, we pursued a general strategy whereby caged small-molecule drugs or imaging agents liberate their parent compounds in regions of low interstitial pH. In this manuscript, we present a new acid-labile prodrug method based on the glycosylamine linkage, and its application to a class of positron emission tomography (PET) imaging tracers, termed [(18)F]FDG amines. [(18)F]FDG amines operate via a proposed two-step mechanism, in which an acid-labile precursor decomposes to form the common radiotracer 2-deoxy-2-[(18)F]fluoro-d-glucose, which is subsequently accumulated by glucose avid cells. The rate of decomposition of [(18)F]FDG amines is tunable in a systematic fashion, tracking the pKa of the parent amine. In vivo, a 4-phenylbenzylamine [(18)F]FDG amine congener showed greater relative accumulation in tumors over benign tissue, which could be attenuated upon tumor alkalinization using previously validated models, including sodium bicarbonate treatment, or overexpression of carbonic anhydrase. This new class of PET tracer represents a viable approach for imaging acidic interstitial pH with potential for clinical translation.

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

    PubMed Central

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

    2016-01-01

    Differentiation between neoplastic and nonneoplastic conditions magnetic resonance imaging (MRI) has established itself as one of the key clinical tools in evaluation of musculoskeletal pathology. However, MRI still has several key limitations which require supplemental information from additional modalities to complete evaluation of various disorders. This has led to the development hybrid positron emission tomography (PET)-MRI which is rapidly evolving to address key clinical questions by using the morphological strengths of MRI and functional information of PET imaging. In this article, we aim to review physical principles and techniques of PET-MRI and discuss clinical utility of functional information obtained from PET imaging and structural information obtained from MRI imaging for the evaluation of musculoskeletal pathology. More specifically, this review highlights the role of PET-MRI in musculoskeletal oncology including initial diagnosis and staging, treatment planning and post-treatment follow-up. Also we will review utility of PET-MRI in evaluating musculoskeletal infections (especially in the immunocompromised and diabetics) and inflammatory condition. Additionally, common pitfalls of PET-MRI will be addressed. PMID:27027320

  14. F-18 Fluorodeoxyglucose Positron Emission Tomography study of Impaired Emotion Processing in First Episode Schizophrenia

    PubMed Central

    Choudhary, Mona; Kumar, Arvind; Tripathi, Madhavi; Bhatia, Triptish; Shivakumar, Venkataram; Beniwal, Ram Pratap; Gur, Ruben C.; Gur, Raquel E.; Nimgaonkar, Vishwajit L.

    2015-01-01

    Background Schizophrenia cases have consistently shown to have behavioural and neurofunctional abnormalities but studies during early course are scarce. The present work assesses the performance of acute first episode schizophrenia cases on correlation of a facial emotion perception task with brain function using Fluorine-18 Fluorodeoxyglucose (FDG) positron emission tomography (PET). Methods Twenty First episode schizophrenia cases and 20 matched healthy controls living in the community were enrolled. For cases, longest duration of illness was one year and treatment with neuroleptic did not exceed two weeks on the day of scan. To measure facial emotion perception (FEP) both groups were administered the Emotion battery from the Penn Computerized Battery followed by PET acquisition. SPM 8 analysis for group differences at p<0.001 was performed. Results Schizophrenia subjects showed hypoactivation of bilateral prefrontal cortices and fusiform gyrii, with significant hyperactivation of bilateral basal ganglia and left precuneus. Positive correlation of metabolism in prefrontal cortex and performance indices on emotions domain was seen. No correlation of CPZ equivalent days with metabolism in basal ganglia was observed. Conclusions The performance of schizophrenia cases on FEP task was significantly impaired in comparison to the control group. Brain regions implicated in emotion processing showed hypometabolism in cases as compared to controls. Failure of schizophrenia cases to optimally recruit brain circuitry may be contributing to deficits on FEP task. These findings suggest inherent deficits in neural circuitry of emotion processing in schizophrenia; devoid of confounding effects of neuroleptics and duration of illness. PMID:25655909

  15. [Multi-center study of inter-scanner difference in brain positron emission tomography].

    PubMed

    Oda, Keiichi; Sakata, Muneyuki; Nishio, Tomoyuki; Tsushima, Hiroyuki; Tanizaki, Yasuo; Kato, Seiji; Ochi, Shinji

    2012-01-01

    We showed scanner dependence of brain (18)F-FDG and (11)C-PiB images by using phantom examination with nine kinds of positron emission tomography (PET) scanners. We used two types of phantoms, cylindrical phantom with 15 cm inside diameter and three-dimensional (3D) brain phantom, and we set the body phantom on the bed to examine the effect of scatter and random coefficients from outside of the axial field of view (AFOV). Radioactivity and distance of the two phantoms were determined by a pilot study to obtain a condition similar to the clinical study. Axial uniformity was evaluated by circular region of interest (ROI) of 12 cm diameter, set in the center of the reconstruction image of the cylindrical phantom. As a result, the standardized uptake value (SUV) was lower than the true value in some scanners, and there was a scanner in which the axial uniformity was deteriorated by high radioactivity outside the AFOV. In the cylindrical phantom, the axial uniformity of the scanner was improved using the new dead-time correction method; however, it was not improved in the 3D brain phantom. Quality-controlled PET scanners are important to maintain constant levels for multicenter studies.

  16. Clinical Utility of Positron Emission Tomography Magnetic Resonance Imaging (PET-MRI) in Gastrointestinal Cancers

    PubMed Central

    Matthews, Robert; Choi, Minsig

    2016-01-01

    Anatomic imaging utilizing both CT (computed tomography) and MRI (magnetic resonance imaging) limits the assessment of cancer metastases in lymph nodes and distant organs while functional imaging like PET (positron emission tomography) scan has its limitation in spatial resolution capacity. Hybrid imaging utilizing PET-CT and PET-MRI are novel imaging modalities that are changing the current landscape in cancer diagnosis, staging, and treatment response. MRI has shown to have higher sensitivity in soft tissue, head and neck pathology, and pelvic disease, as well as, detecting small metastases in the liver and bone compared to CT. Combining MRI with PET allows for detection of metastases that may have been missed with current imaging modalities. In this review, we will examine the clinical utility of FDG PET-MRI in the diagnosis and staging of gastrointestinal cancers with focus on esophageal, stomach, colorectal, and pancreatic cancers. We will also explore its role in treatment response and future directions associated with it. PMID:27618106

  17. Study of direct and indirect parametric estimation methods of linear models in dynamic positron emission tomography.

    PubMed

    Tsoumpas, Charalampos; Turkheimer, Federico E; Thielemans, Kris

    2008-04-01

    In dynamic positron emission tomography (PET) studies, the time changing activity of the radiotracer is measured through multiple consecutive frames. Subsequent pixel-by-pixel application of the appropriate kinetic model provides quantitative information in terms of images of the distribution of the physiological parameter of interest. In this context, iterative reconstruction methods may be used to reconstruct for each time frame a static image of appreciable higher quality than the analytical algorithms, especially in low-count cases. Furthermore, if the reconstruction algorithm also models the kinetics of the measured counts, the parametric image is expected to be of even higher quality. In this work, we investigate the methodology to directly reconstruct parametric images in three-dimensional PET when the kinetic model is linear in its parameters (Patlak plot) and compare with indirectly estimated parametric maps, where the radioactivity distribution was estimated by the filtered back projection and ordered subsets expectation maximization algorithms. Both real and simulated data for tracers with irreversible kinetics in brain studies are included. The results demonstrate appreciable smaller standard deviation and mean squared error characteristics for the direct reconstruction. However, some regions may converge slowly. The FBP and ordered subsets expectation maximization (OSEM) indirect estimations have a similar level of bias after matching their resolutions, but OSEM has smaller standard deviation.

  18. An investigation into positron emission tomography contouring methods across two treatment planning systems

    SciTech Connect

    Young, Tony; Som, Seu; Sathiakumar, Chithradevi; Holloway, Lois

    2013-04-01

    Positron emission tomography (PET) imaging has been used to provide additional information regarding patient tumor location, size, and staging for radiotherapy treatment planning purposes. This additional information reduces interobserver variability and produces more consistent contouring. It is well recognized that different contouring methodology for PET data results in different contoured volumes. The goal of this study was to compare the difference in PET contouring methods for 2 different treatment planning systems using a phantom dataset and a series of patient datasets. Contouring methodology was compared on the ADAC Pinnacle Treatment Planning System and the CMS XiO Treatment Planning System. Contours were completed on the phantom and patient datasets using a number of PET contouring methods—the standardized uptake value 2.5 method, 30%, 40%, and 50% of the maximum uptake method and the signal to background ratio method. Differences of >15% were observed for PET-contoured volumes between the different treatment planning systems for the same data and the same PET contouring methodology. Contoured volume differences between treatment planning systems were caused by differences in data formatting and display and the different contouring tools available. Differences in treatment planning system as well as contouring methodology should be considered carefully in dose-volume contouring and reporting, especially between centers that may use different treatment planning systems or those that have several different treatment planning systems.

  19. Positron emission tomography findings in children with infantile spasms and autism.

    PubMed

    Dilber, Cengiz; Calışkan, Mine; Sönmezoğlu, Kerim; Nişli, Serap; Mukaddes, Nahit Motavalli; Tatlı, Burak; Aydınlı, Nur; Ekici, Barış; Özmen, Meral

    2013-03-01

    The purpose of this study was to evaluate positron emission tomography (PET) findings in patients diagnosed with infantile spasms and autism. This study includes 90 patients who were diagnosed with infantile spasms at the Department of Pediatric Neurology in the Istanbul University Medical Faculty between 1995 and 2007. Of the 90 patients, 15 patients who were diagnosed with autism using the Autism Behaviour Checklist and Childhood Autism Rating Scale and a control group of nine patients without autism but with infantile spasms underwent PET examination. Mean patient age (± standard error, SE) varied between 3 years and 16 years (7.8 ± 4 years), while the mean follow-up time (±SE) varied between 2 years and 16 years (average: 7.1 ± 4 years). Autism was present in 11 patients with symptomatic spasms and in four patients with cryptogenic spasms (p=0.009). On the PET scans of the 15 patients with autism, 13 (86.7%) had significantly decreased metabolic activity in the temporal lobe (p<0.001), nine (60%) had significantly decreased activity in the frontal lobe (p=0.004), and seven (46.7%) had significantly decreased activity in the parietal lobe (p=0.022). In our opinion, hypometabolism in the frontal and parietal lobes, in addition to that previously reported in the temporal lobe, plays a role in the development of autism in patients with infantile spasms.

  20. Initial characterization of a BGO-photodiode detector for high resolution positron emission tomography

    SciTech Connect

    Derenzo, S.E.

    1983-11-01

    Spatial resolution in positron emission tomography is currently limited by the resolution of the detectors. This work presents the initial characterization of a detector design using small bismuth germanate (BGO) crystals individually coupled to silicon photodiodes (SPDs) for crystal identification, and coupled in groups to phototubes (PMTs) for coincidence timing. A 3 mm x 3 mm x 3 mm BGO crystal coupled only to an SPD can achieve a 511 keV photopeak resolution of 8.7% FWHM at -150/sup 0/C, using a pulse peaking time of 10 ..mu..s. When two 3 mm x 3 mm x 15 mm BGO crystals are coupled individually to SPDs and also coupled to a common 14 mm diam PMT, the SPDs detect the 511 keV photopeak with a resolution of 30% FWHM at -76/sup 0/C. In coincidence with an opposing 3 mm wide BGO crystal, the SPDs are able to identify the crystal of interaction with good signal-to-noise ratio, and the detector pair resolution is 2 mm FWHM. 32 references, 7 figures, 3 tables.

  1. Effect of Harderian adenectomy on the statistical analyses of mouse brain imaging using positron emission tomography

    PubMed Central

    Kim, Minsoo; Woo, Sang-Keun; Yu, Jung Woo; Lee, Yong Jin; Kim, Kyeong Min; Kang, Joo Hyun; Eom, Kidong

    2014-01-01

    Positron emission tomography (PET) using 2-deoxy-2-[18F] fluoro-D-glucose (FDG) as a radioactive tracer is a useful technique for in vivo brain imaging. However, the anatomical and physiological features of the Harderian gland limit the use of FDG-PET imaging in the mouse brain. The gland shows strong FDG uptake, which in turn results in distorted PET images of the frontal brain region. The purpose of this study was to determine if a simple surgical procedure to remove the Harderian gland prior to PET imaging of mouse brains could reduce or eliminate FDG uptake. Measurement of FDG uptake in unilaterally adenectomized mice showed that the radioactive signal emitted from the intact Harderian gland distorts frontal brain region images. Spatial parametric measurement analysis demonstrated that the presence of the Harderian gland could prevent accurate assessment of brain PET imaging. Bilateral Harderian adenectomy efficiently eliminated unwanted radioactive signal spillover into the frontal brain region beginning on postoperative Day 10. Harderian adenectomy did not cause any post-operative complications during the experimental period. These findings demonstrate the benefits of performing a Harderian adenectomy prior to PET imaging of mouse brains. PMID:23820224

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

    PubMed

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

    2014-10-01

    Positron emission tomography (PET) can be used to monitor the uptake of the labeled glucose analog fluorodeoxyglucose (¹⁸F-FDG), a process that is generally believed to reflect viable tumor cell mass. The use of ¹⁸F-FDG PET can be helpful in documenting over time the reduction in tumor mass volume in response to anticancer drug therapy in vivo. In this protocol, we describe how to monitor the response of murine B-cell lymphomas to an inducer of apoptosis, the anticancer drug vorinostat (a histone deacetylase inhibitor). B-cell lymphoma cells are injected into recipient mice and, on tumor formation, the mice are treated with vorinostat. The tracer ¹⁸F-FDG is