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55 result(s) for "Thomassen, Anders"
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Definitions of Incidental 18FFDG PET/CT Findings in the Literature: A Systematic Review and Definition Proposal
Objectives: The objectives of this study were (1) to systematically review the currently used definitions of incidental 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography findings (IPFs) in the literature and (2) to propose an IPF definition. Methods: A systematic search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search was guided by the question “How is IPF defined?” and was performed in MEDLINE, Embase, and the Cochrane Library. The retrieved studies were reviewed and analyzed. The definitions of IPFs in the included studies were compiled into two sets of categories based on the description of FDG uptake and the specification of clinical factors in defining IPFs. Results: The systematic literature search identified 4852 publications accessible for title–abstract screening, which yielded 395 studies for full-text assessment. Sixty-five studies met the eligibility criteria and were included. Sixty-two percent mentioned “FDG uptake” in their definition. In 40% of the definitions, “Focal FDG uptake” was specified, while “FDG uptake in the surrounding tissue” was included in 15%. Fifty-seven percent stated that IPFs were “Unrelated to PET/CT indication”. Thirty-four percent specified IPFs as “Present in other organ than PET/CT indication”, whereas 20% included “No known disease related to IPF”. Seventeen percent of the definitions comprised a “New finding”, while 15% and 11% encompassed a “Clinical asymptomatic patient” and “Not a metastasis”, respectively. Finally, 5% of the definitions included “Potential clinical significance”. Conclusions: No generally accepted definition of IPFs currently exists. We propose an IPF definition based on explicit FDG uptake and clinical patient-related factors.
Seeing the Unseen—Bioturbation in 4D: Tracing Bioirrigation in Marine Sediment Using Positron Emission Tomography and Computed Tomography
Understanding spatial and temporal patterns of bioirrigation induced by benthic fauna ventilation is critical given its significance on benthic nutrient exchange and biogeochemistry in coastal ecosystems. The quantification of this process challenges marine scientists because faunal activities and behaviors are concealed in an opaque sediment matrix. Here, we use a hybrid medical imaging technique, positron emission tomography and computed tomography (PET/CT) to provide a qualitative visual and fully quantitative description of bioirrigation in 4D (space and time). As a study case, we present images of porewater advection induced by the well-studied lugworm (Arenicola marina). Our results show that PET/CT allows more comprehensive studies on ventilation and bioirrigation than possible using techniques traditionally applied in marine ecology. We provide a dynamic three-dimensional description of bioirrigation by the lugworm at very high temporal and spatial resolution. Results obtained with the PET/CT are in agreement with literature data on lugworm ventilation and bioirrigation. Major advantages of PET/CT over methods commonly used are its non-invasive and non-destructive approach and its capacity to provide information that otherwise would require multiple methods. Furthermore, PET/CT scan is versatile as it can be used for a variety of benthic macrofauna species and sediment types and it provides information on burrow morphology or animal behavior. The lack of accessibility to the expensive equipment is its major drawback which can only be overcome through collaboration among several institutions.
Patients With Suspected Coronary Artery Disease Referred for Examinations in the Era of Coronary Computed Tomography Angiography
Invasive coronary angiography (ICA) is the gold standard in the diagnosis of coronary artery disease (CAD), however, associated with rare but severe complications. Patients with a high pretest risk should be referred directly for ICA, whereas a noninvasive strategy is recommended in the remaining patients. In the setting of a university hospital, we investigated the pattern of diagnostic tests used in daily clinical practice. During a 1-year period, consecutive patients with new symptoms suggestive of CAD and referred for exercise stress test, coronary computed tomography angiography (CCTA), single-photon emission computed tomography (SPECT), or ICA qualified for inclusion. The patients were followed for 1 year, and additional downstream diagnostic tests and need of coronary revascularization were registered. A total of 1,069 patients were included. A noninvasive test was the first examination in 797 patients (75%; exercise stress test in 37, CCTA in 450, and SPECT in 310), whereas 272 (25%) were referred directly to ICA. The ICA group had a significant higher pretest probability for CAD, and the percentage of patients with evidence of significant CAD was 31% (84 of 272 patients), whereas 18% (144 of 797 patients) in the noninvasive group (p <0.0001). In the comparison between CCTA and SPECT, there were no significant differences in downstream testing (16% [72 of 444 patients] vs 17% [53 of 310], p = 0.55), and revascularization rate (20% [14 of 69 patients with positive findings] vs 9% [6 of 67], p = 0.09). In conclusion, a noninvasive diagnostic test was chosen as the first test in 3 of 4 patients. Of the patients referred directly for noninvasive examination, 1/5 had significant CAD, whereas 1/3 of those for invasive examination.
18F-FDG PET/CT to differentiate malignant necrotic lymph node from benign cystic lesions in the neck
Objective Patients presenting with cystic lesions in the neck without obvious signs of malignancy constitute a diagnostic challenge since fine needle aspiration is often insufficient and a diagnosis may not be reached until surgical resection/biopsy is performed. The differential diagnosis of a cystic cervical mass comprises a variety of benign conditions, but malignancy must be ruled out. We examined the diagnostic performance of fluorine-18 fluorodeoxyglucose ( 18 F-FDG) PET/CT to identify malignancy. Methods We retrospectively included consecutive patients referred from the Department of ENT Head and Neck Surgery for 18 F-FDG PET/CT-scans because of a solitary neck cyst. Scan results were compared to histopathology and follow-up. Results The study comprised 58 patients. Twenty patients (34%) were diagnosed with cancer during follow-up. PET/CT suggested malignancy in 34 patients (19 true positive, 15 false positive) and showed no malignancy in 24 (23 true negative, 1 false negative). The sensitivity, specificity, accuracy, positive and negative predictive values were 95% (76–99%), 61% (45–74%), 72% (60–82%), 56% (39–71%), and 96% (80–99%), respectively (95% confidence intervals in brackets). The primary tumor was identified in 14 out of the 20 patients with confirmed cancer. Increased metabolism, as evaluated by PET, was the only imaging characteristic among several others, which associated independently with malignancy in the cystic neck lesions, odds ratio 1.27 (1.07–1.50), p  = 0.006. Conclusion 18 F-FDG PET/CT could reliably rule out malignancy (NPV 96%), albeit with a high frequency of false positive scans, requiring further diagnostic work-up. Increased metabolism was the best imaging parameter to differentiate between malignant and benign lesions.
Duration of 18F-FDG avidity in lymph nodes after pandemic H1N1v and seasonal influenza vaccination
Purpose The aim of our study was to investigate the occurrence of fluorodeoxyglucose (FDG) avidity in draining axillary lymph nodes after vaccination against influenza (H1N1v pandemic and seasonal) and to determine the period of increased FDG uptake. Methods During December 2009, patients referred for 18 F-FDG positron emission tomography (PET)/CT scans ( n  = 293) filled in a questionnaire concerning vaccination type (seasonal and/or H1N1v), time and anatomical localization of vaccination. Only injections in deltoid regions were evaluated, thus ensuring that draining lymph nodes were axillary. If more vaccinations had been given, only the latest vaccination was evaluated in each deltoid region. Results Of all patients who underwent PET/CT scans during December 2009, 26% had been vaccinated with at least one influenza vaccination in the deltoid region. A total of 92 ‘draining’ and 60 ‘reference’ (i.e. contralateral, non-vaccinated) axillary lymph nodes were evaluated in 61 patients (19 of 61 patients were scanned twice). The maximal intensity in FDG uptake (SUV max ) in draining lymph nodes was 5 g/ml body weight (BW), whereas the maximal intensity in reference lymph nodes was 1.9 g/ml BW. The SUV max was normalized approximately 40 days after vaccination. No significant enlargement of metabolically active draining lymph nodes could be demonstrated on CT scan. Chemotherapy or immunosuppressive drugs given within 2 weeks from vaccination did not affect SUV max in the axillary lymph nodes. Conclusion Influenza vaccination may lead to FDG-avid draining lymph nodes beyond 1 month.
Thoracic aorta calcification but not inflammation is associated with increased cardiovascular disease risk: results of the CAMONA study
Purpose Arterial inflammation and vascular calcification are regarded as early prognostic markers of cardiovascular disease (CVD). In this study we investigated the relationship between CVD risk and arterial inflammation ( 18 F-FDG PET/CT imaging), vascular calcification metabolism (Na 18 F PET/CT imaging), and vascular calcium burden (CT imaging) of the thoracic aorta in a population at low CVD risk. Methods Study participants underwent blood pressure measurements, blood analyses, and 18 F-FDG and Na 18 F PET/CT imaging. In addition, the 10-year risk for development of CVD, based on the Framingham risk score (FRS), was estimated. CVD risk was compared across quartiles of thoracic aorta 18 F-FDG uptake, Na 18 F uptake, and calcium burden on CT. Results A total of 139 subjects (52 % men, mean age 49 years, age range 21 – 75 years, median FRS 6 %) were evaluated. CVD risk was, on average, 3.7 times higher among subjects with thoracic aorta Na 18 F uptake in the highest quartile compared with those in the lowest quartile of the distribution (15.5 % vs. 4.2 %; P  < 0.001). CVD risk was on average, 3.7 times higher among subjects with a thoracic aorta calcium burden on CT in the highest quartile compared with those in the lowest two quartiles of the distribution (18.0 % vs. 4.9 %; P  < 0.001). CVD risk was similar in subjects in all quartiles of thoracic aorta 18 F-FDG uptake. Conclusion Our findings indicate that an unfavourable CVD risk profile is associated with marked increases in vascular calcification metabolism and vascular calcium burden of the thoracic aorta, but not with arterial inflammation.
Carotid artery molecular calcification assessed by 18Ffluoride PET/CT: correlation with cardiovascular and thromboembolic risk factors
There is growing evidence that sodium fluoride ([18F]fluoride) PET/CT can detect active arterial calcifications at the molecular stage. We investigated the relationship between arterial mineralization in the left common carotid artery (LCC) assessed by [18F]fluoride PET/CT and cardiovascular/thromboembolic risk.OBJECTIVESThere is growing evidence that sodium fluoride ([18F]fluoride) PET/CT can detect active arterial calcifications at the molecular stage. We investigated the relationship between arterial mineralization in the left common carotid artery (LCC) assessed by [18F]fluoride PET/CT and cardiovascular/thromboembolic risk.In total, 128 subjects (mean age 48 ± 14 years, 51% males) were included. [18F]fluoride uptake in the LCC was quantitatively assessed by measuring the blood-pool-corrected maximum standardized uptake value (SUVmax) on each axial slice. Average SUVmax (aSUVmax) was calculated over all slices and correlated with 10-year risk of cardiovascular events estimated by the Framingham model, CHA2DS2-VASc score, and level of physical activity (LPA).METHODSIn total, 128 subjects (mean age 48 ± 14 years, 51% males) were included. [18F]fluoride uptake in the LCC was quantitatively assessed by measuring the blood-pool-corrected maximum standardized uptake value (SUVmax) on each axial slice. Average SUVmax (aSUVmax) was calculated over all slices and correlated with 10-year risk of cardiovascular events estimated by the Framingham model, CHA2DS2-VASc score, and level of physical activity (LPA).The aSUVmax was significantly higher in patients with increased risk of cardiovascular (one-way ANOVA, p < 0.01) and thromboembolic (one-way ANOVA, p < 0.01) events, and it was significantly lower in patients with greater LPA (one-way ANOVA, p = 0.02). On multivariable linear regression analysis, age ( = 0.07, 95% CI 0.05 - 0.10, p < 0.01), body mass index ( = 0.02, 95% CI 0.01 - 0.03, p < 0.01), arterial hypertension ( = 0.15, 95% CI 0.08 - 0.23, p < 0.01), and LPA ( = -0.10, 95% CI -0.19 to -0.02, p=0.02) were independent associations of aSUVmax.RESULTSThe aSUVmax was significantly higher in patients with increased risk of cardiovascular (one-way ANOVA, p < 0.01) and thromboembolic (one-way ANOVA, p < 0.01) events, and it was significantly lower in patients with greater LPA (one-way ANOVA, p = 0.02). On multivariable linear regression analysis, age ( = 0.07, 95% CI 0.05 - 0.10, p < 0.01), body mass index ( = 0.02, 95% CI 0.01 - 0.03, p < 0.01), arterial hypertension ( = 0.15, 95% CI 0.08 - 0.23, p < 0.01), and LPA ( = -0.10, 95% CI -0.19 to -0.02, p=0.02) were independent associations of aSUVmax.Carotid [18F]fluoride uptake is significantly increased in patients with unfavorable cardiovascular and thromboembolic risk profiles. [18F]fluoride PET/CT could become a valuable tool to estimate subjects' risk of future cardiovascular events although still major trials are needed to further evaluate the associations found in this study and their potential clinical usefulness.CONCLUSIONSCarotid [18F]fluoride uptake is significantly increased in patients with unfavorable cardiovascular and thromboembolic risk profiles. [18F]fluoride PET/CT could become a valuable tool to estimate subjects' risk of future cardiovascular events although still major trials are needed to further evaluate the associations found in this study and their potential clinical usefulness.• Sodium fluoride ([18F]fluoride) PET/CT imaging identifies patients with early-stage atherosclerosis. • Carotid [18F]fluoride uptake is significantly higher in patients with increased risk of cardiovascular and thromboembolic events and inversely correlated with the level of physical activity. • Early detection of arterial mineralization at a molecular level could help guide clinical decisions in the context of cardiovascular risk assessment.KEY POINTS• Sodium fluoride ([18F]fluoride) PET/CT imaging identifies patients with early-stage atherosclerosis. • Carotid [18F]fluoride uptake is significantly higher in patients with increased risk of cardiovascular and thromboembolic events and inversely correlated with the level of physical activity. • Early detection of arterial mineralization at a molecular level could help guide clinical decisions in the context of cardiovascular risk assessment.
Risk of Malignancy in FDG-Avid Thyroid Incidentalomas on PET/CT: A Prospective Study
Background Due to a substantial risk of malignancy, patients with focal FDG-avid thyroid incidentalomas (FFTIs) on PET/CT are in most of Denmark referred to Head and Neck Cancer (HNC) fast track programs. The aim of this study was to determine the risk of malignancy in FFTI managed in a HNC fast track program. Methods A prospective cohort study including all patients with FFTI referred to the HNC fast track program, Odense University Hospital between September 1, 2016 and August 31, 2017. Ultrasonography (US) and fine-needle aspiration biopsy (FNAB) were intended to be done in all patients. Nodules with cytology of Bethesda 1, 3, 4, 5, or 6 were planned for surgical removal . Results A total of 104 patients were included. All patients had US and 101 patients (97%) had FNAB. Forty-two patients had benign cytology classified as Bethesda 2. The remaining 62 patients underwent surgery except from 11 patients, mainly due to comorbidity. The overall risk of malignancy for patients with FFTI referred to our HNC fast track program was calculated to be 24% (23/95) based on patients with unequivocal cytology and/or histology. The only statistically significant US characteristic to predict malignancy was the appearance of irregular margins with a sensitivity of 47% and specificity of 96%. Conclusion The risk of malignancy of FFTIs handled in our HNC fast track program is 24%.
Definitions of Incidental 18FFDG PET/CT Findings in the Literature: A Systematic Review and Definition Proposal
Objectives: The objectives of this study were (1) to systematically review the currently used definitions of incidental 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography findings (IPFs) in the literature and (2) to propose an IPF definition. Methods: A systematic search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search was guided by the question \"How is IPF defined?\" and was performed in MEDLINE, Embase, and the Cochrane Library. The retrieved studies were reviewed and analyzed. The definitions of IPFs in the included studies were compiled into two sets of categories based on the description of FDG uptake and the specification of clinical factors in defining IPFs. Results: The systematic literature search identified 4852 publications accessible for title-abstract screening, which yielded 395 studies for full-text assessment. Sixty-five studies met the eligibility criteria and were included. Sixty-two percent mentioned \"FDG uptake\" in their definition. In 40% of the definitions, \"Focal FDG uptake\" was specified, while \"FDG uptake in the surrounding tissue\" was included in 15%. Fifty-seven percent stated that IPFs were \"Unrelated to PET/CT indication\". Thirty-four percent specified IPFs as \"Present in other organ than PET/CT indication\", whereas 20% included \"No known disease related to IPF\". Seventeen percent of the definitions comprised a \"New finding\", while 15% and 11% encompassed a \"Clinical asymptomatic patient\" and \"Not a metastasis\", respectively. Finally, 5% of the definitions included \"Potential clinical significance\". Conclusions: No generally accepted definition of IPFs currently exists. We propose an IPF definition based on explicit FDG uptake and clinical patient-related factors.Objectives: The objectives of this study were (1) to systematically review the currently used definitions of incidental 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography findings (IPFs) in the literature and (2) to propose an IPF definition. Methods: A systematic search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search was guided by the question \"How is IPF defined?\" and was performed in MEDLINE, Embase, and the Cochrane Library. The retrieved studies were reviewed and analyzed. The definitions of IPFs in the included studies were compiled into two sets of categories based on the description of FDG uptake and the specification of clinical factors in defining IPFs. Results: The systematic literature search identified 4852 publications accessible for title-abstract screening, which yielded 395 studies for full-text assessment. Sixty-five studies met the eligibility criteria and were included. Sixty-two percent mentioned \"FDG uptake\" in their definition. In 40% of the definitions, \"Focal FDG uptake\" was specified, while \"FDG uptake in the surrounding tissue\" was included in 15%. Fifty-seven percent stated that IPFs were \"Unrelated to PET/CT indication\". Thirty-four percent specified IPFs as \"Present in other organ than PET/CT indication\", whereas 20% included \"No known disease related to IPF\". Seventeen percent of the definitions comprised a \"New finding\", while 15% and 11% encompassed a \"Clinical asymptomatic patient\" and \"Not a metastasis\", respectively. Finally, 5% of the definitions included \"Potential clinical significance\". Conclusions: No generally accepted definition of IPFs currently exists. We propose an IPF definition based on explicit FDG uptake and clinical patient-related factors.
Definitions of Incidental sup.18FFDG PET/CT Findings in the Literature: A Systematic Review and Definition Proposal
Objectives : The objectives of this study were (1) to systematically review the currently used definitions of incidental 2-deoxy-2-[[sup.18] F]fluoro-D-glucose positron emission tomography/computed tomography findings (IPFs) in the literature and (2) to propose an IPF definition. Methods : A systematic search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search was guided by the question “How is IPF defined?” and was performed in MEDLINE, Embase, and the Cochrane Library. The retrieved studies were reviewed and analyzed. The definitions of IPFs in the included studies were compiled into two sets of categories based on the description of FDG uptake and the specification of clinical factors in defining IPFs. Results : The systematic literature search identified 4852 publications accessible for title–abstract screening, which yielded 395 studies for full-text assessment. Sixty-five studies met the eligibility criteria and were included. Sixty-two percent mentioned “FDG uptake” in their definition. In 40% of the definitions, “Focal FDG uptake” was specified, while “FDG uptake in the surrounding tissue” was included in 15%. Fifty-seven percent stated that IPFs were “Unrelated to PET/CT indication”. Thirty-four percent specified IPFs as “Present in other organ than PET/CT indication”, whereas 20% included “No known disease related to IPF”. Seventeen percent of the definitions comprised a “New finding”, while 15% and 11% encompassed a “Clinical asymptomatic patient” and “Not a metastasis”, respectively. Finally, 5% of the definitions included “Potential clinical significance”. Conclusions : No generally accepted definition of IPFs currently exists. We propose an IPF definition based on explicit FDG uptake and clinical patient-related factors.