scholarly journals Positron emission computed tomography for the evaluation of abdominal aortic aneurysms and risk of rupture

2013 ◽  
Author(s):  
Νικόλαος Ρούσας
Keyword(s):  
Computed Tomography ◽  
Cell Density ◽  
Fdg Pet ◽  
Ct Imaging ◽  
Fdg Uptake ◽  
Positron Emission ◽  
Abdominal Aortic ◽  
Pet Ct ◽  
Acute Complications ◽  
The Mean

Rupture is an acute and life-threatening complication of abdominal aortic aneurysm (AAA) and its incidence increases in parallel with aortic diameter. Nowadays, surgery is currently indicated for aneurysms with diameter≥5.5 cm. However, even in AAAs of subthreshold diameter (4.0–5.5 cm) the incidence of acute complications remains significant, ranging from 1 to 5% per year. Thus, risk stratification in these patients remains a major issue in vascular medicine and calls for a better capability to explore mechanisms underlying AAA acute complications. This task has been facilitated by studies documenting a relevant role for inflammatory infiltrates able to accelerate the proteolysis of elastin and collagen of aortic wall via the release of matrix metalloproteinases and proinflammatory cytokines. These biological mechanisms recently gained renewed interest due to the capability of positron emission tomography (PET)/CT imaging with fluorodeoxyglucose (FDG) to highlight the insulin-independent glucose uptake of activated lymphocytes and macrophages infiltrating the diseased aortic segment. However, more recent reports, including our own experience, were barely able to spot any visible FDG uptake in AAAs whose diameter size was just below the surgical threshold of 5.5 cm [15, 16In the present studies, we planned to verify the prevalence of visible FDG uptake in aneurysmal walls, adopting a case control approach. Moreover, we tested the hypothesis that with increasing AAA diameter cell density is too low to permit any visible FDG uptake. The first study included 40 males (mean age: 74 years, range: 59-93 years), with asymptomatic infrarenal AAA. The mean diameter of AAA was 4.9 cm (range: 4.8e5.4 cm), detected by computed tomography (CT) scan. Control Subjects: 44 age-matched controls subjects (mean age: 71 years, range: 59-85 years, 24 males, 20 females) who were selected from a population of patients without any clinical evidence of atherosclerotic disease. Patients and controls underwent simultaneous FDG-PET/ CT imaging from the skull base to the femoral neck. For the quantitative analysis, circular CT-based regions of interest (ROIs) were drawn on the AAA, on all the aortic segments, and on the large vessel included in the study (carotid, subclavian, and iliac arteries). FDG uptake was quantified by calculating the mean and maximum standardized uptake values (SUVs) within each ROI and normalizing for the blood-pool SUV to obtain the final target-to-background ratio.The metabolic activity in the aneurysmal aortic segment was even lower with respect to both the adjacent non aneurysmal samples of patient group and the corresponding arterial segments of control subjects (P < 0.001 and P < 0.01, respectively). In the second study (PET)/CT imaging was performed in 12 consecutive candidates for AAA surgical repair and in 12 age- and sex-matched controls. At intervention, aneurysmal walls were cut into three sequential blocks. Block A was frozen to cut three 5-μm slices for incubation with 2–3 MBq of FDG for 5 min. Block C was first incubated with the same tracer solution for the same time and subsequently frozen to cut three 5-μm slices. Autoradiographic images were co-registered with immunohistochemical pictures of cell density, type and DNA synthesis as assessed on block B. No visible uptake in abdominal aorta occurred in any patient or control subject. Immunohistochemistry documented a severe loss of wall structure, with low numbers of cells. Tracer retention directly correlated with overall cell density and with prevalence of cells synthesizing DNA. The metabolic nature of FDG uptake was confirmed by the selective effect of preliminary freezing that decreased tracer content by 90% in regions with high cell density and only by 34% in cold acellular areas.So the loss of tissue structure and the marked decrease in cell density account for the low prevalence of positive findings at FDG PET imaging, at least in asymptomatic patients bearing AAAs whose diameter is close to surgical indication

Positron Emission Tomography/Computed Tomography Predicts and Detects Complications After Endovascular Repair of Abdominal Aortic Aneurysms

2019 ◽  
Vol 26 (4) ◽  
pp. 520-528 ◽  
Author(s):  
Audrey Courtois ◽  
Georgios Makrygiannis ◽  
Mounia El Hachemi ◽  
Rebecka Hultgren ◽  
Eric Allaire ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Endovascular Aneurysm Repair ◽  
Aortic Aneurysms ◽  
Emission Tomography ◽  
Fdg Uptake ◽  
Positron Emission ◽  
Abdominal Aortic ◽  
Pet Ct ◽  
D Dimer

Purpose: To assess if aortic 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT) could play a role in predicting complications after endovascular aneurysm repair (EVAR). Materials and Methods: This study involved 2 cohorts of men with abdominal aortic aneurysm treated by EVAR: those who underwent a PET/CT scan before EVAR (n=17) and those who had a PET/CT during follow-up (n=34). Uptake of FDG was measured as the standardized uptake value (SUV). D-dimer, a marker of fibrinolysis, was measured in blood drawn concomitantly with the PET/CT. Results: A significant uptake of FDG in the aneurysm wall was detected by PET/CT before EVAR in 6 of 17 patients. During the first year after EVAR, type II endoleaks developed in 5 of these FDG+ patients vs 3 of 11 FDG– patients (p=0.04). Two of the FDG+ patients had continued sac growth and required conversion to open repair. A significant association between sac growth rate, SUV, and the presence of endoleak was found in the 34 patients who underwent PET/CT after EVAR. Finally, D-dimer was significantly increased in patients with both endoleak and positive PET/CT in the post-EVAR group. Conclusion: This study suggests that the presence of FDG uptake in the aortic wall might be a useful tool to predict patients at high risk of developing post-EVAR complications.

scholarly journals Physiological Appearance of Hybrid FDG–Positron Emission Tomography/Computed Tomography Imaging Following Uncomplicated Endovascular Aneurysm Sealing Using the Nellix Endoprosthesis

2020 ◽  
Vol 27 (3) ◽  
pp. 509-515
Author(s):  
Erik Groot Jebbink ◽  
Leo H. van Den Ham ◽  
Beau B. J. van Woudenberg ◽  
Riemer H. J. A. Slart ◽  
Clark J. Zeebregts ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Fdg Pet ◽  
Graft Infection ◽  
Emission Tomography ◽  
Visual Examination ◽  
Fdg Uptake ◽  
Positron Emission ◽  
Pet Ct ◽  
Fdg Pet Ct

Purpose: To investigate the physiological uptake of hybrid fluorine-18-fluorodeoxyglucose (FDG)–positron emission tomography/computed tomography (PET/CT) before and after an uncomplicated endovascular aneurysm sealing (EVAS) procedure as a possible tool to diagnose EVAS graft infection and differentiate from postimplantation syndrome. Materials and Methods: Eight consecutive male patients (median age 78 years) scheduled for elective EVAS were included in the prospective study ( ClinicalTrials.gov identifier NCT02349100). FDG-PET/CT scans were performed in all patients before the procedure and 6 weeks after EVAS. The abdominal aorta was analyzed in 4 regions: suprarenal, infrarenal neck, aneurysm sac, and iliac. The following parameters were obtained for each region: standard uptake value (SUV), tissue to background ratio (TBR), and visual examination of FDG uptake to ascertain its distribution. Demographic data were obtained from medical files and scored based on reporting standards. Results: Visual examination showed no difference between pre- and postprocedure FDG uptake, which was homogenous. In the suprarenal region no significant pre- and postprocedure differences were observed for the SUV and TBR parameters. The infrarenal neck region showed a significant decrease in the SUV and no significant decrease in the TBR. The aneurysm sac and iliac regions both showed a significant decrease in SUV and TBR between the pre- and postprocedure scans. Conclusion: Physiological FDG uptake after EVAS was stable or decreased with regard to the preprocedure measurements. Future research is needed to assess the applicability and cutoff values of FDG-PET/CT scanning to detect endograft infection after EVAS.

scholarly journals 18F-Fluorodeoxyglucose positron emission tomography-computed tomography imaging in HIV-infected patients with lymphadenopathy, with or without fever and/or splenomegaly

2017 ◽  
Vol 29 (7) ◽  
pp. 691-694
Author(s):  
L Jain ◽  
S Mackenzie ◽  
JB Bomanji ◽  
R Shortman ◽  
M Noursadeghi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Fdg Pet ◽  
Ct Imaging ◽  
Emission Tomography ◽  
Fluorodeoxyglucose Positron Emission Tomography ◽  
Positron Emission ◽  
Pet Ct ◽  
Fdg Pet Ct ◽  
Fluorodeoxyglucose Positron Emission

We audited whether 18F-Fluorodeoxyglucose positron emission tomography-computed tomography (18FDG PET-CT) imaging could discriminate between different diagnoses in HIV-infected patients presenting with lymphadenopathy, with or without fever and/or splenomegaly. Maximum standardised uptake (SUVmax) values were similar in lymphoma and mycobacterial and fungal infections and were lower but similar in those with human herpesvirus (HHV) 8-associated disease and HIV-associated reactive lymphadenopathy. Nodal 18FDG avidity, with SUVmax ≥10, excluded diagnoses of HHV 8-associated disease and miscellaneous conditions, and HIV-associated reactive lymphadenopathy was additionally excluded in those who had undetectable plasma HIV viral loads. This audit suggests 18FDG PET-CT imaging did not permit discrimination between specific diagnoses but has utility in identifying lymph nodes with increased avidity that could be targeted for biopsy and in ruling out significant pathology.

Time-Related Aortic Inflammatory Response, As Assessed With 18F-FDG PET/CT, in Patients Hospitalized With Severe or Critical COVID-19 The COVAIR Study

2021 ◽  
Author(s):  
Charalambos Vlachopoulos ◽  
Dimitrios Terentes - Printzios ◽  
Paraskevi Katsaounou ◽  
Eirini Solomou ◽  
Vassiliki Gardikioti ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Ct Imaging ◽  
Control Group ◽  
Prior History ◽  
Fdg Uptake ◽  
Positron Emission ◽  
Pet Ct ◽  
Arterial Inflammation ◽  
18F Fdg ◽  
Fdg Pet Ct

Abstract AimArterial involvement has been implicated in the coronavirus disease of 2019 (COVID-19). 18F-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging is a valuable tool for the assessment of disease severity in different types of vasculitis and is a predictor of outcome. We sought to prospectively assess the presence of aortic inflammation and its time-dependent trend by measuring the 18-FDG uptake in PET/CT in patients with severe or critical COVID-19.Methods In this pilot case control study, we recruited 20 patients, who were admitted with severe or critical COVID-19 illness. Patients underwent imaging between 20 to 120 days after hospital admission. Ten age- and sex-matched individuals with prior history of malignancy but free of active disease served as the control group. Arterial inflammation was assessed by measuring 18-FDG uptake in PET/CT and calculating aortic target to blood ratio (TBR).ResultsThere was a significant correlation between aortic TBR values and time distance from diagnosis to 18F-FDG PET/CT scan (-rho- =0.547, p=0.015) even after adjustment for confounders (p=0.002). Patients who were scanned less than 60 days (median) from diagnosis had significantly higher TBR values compared to patients examined more than 60 days post-diagnosis (1.55 [1.47-1.61] vs 1.40 [1.33-1.45], respectively, p=0.013).ConclusionThis is the first study suggesting that 18 FDG PET/CT imaging could be used for assessment of arterial inflammation in patients with severe/critical COVID-19. These findings may have important implications for the understanding of the pathophysiology and the course of the disease and for improving our preventive and therapeutic strategies.

FDG-PET/CT Assessment of Pulmonary Sarcoidosis: A Guide for Internists

2018 ◽  
Vol 15 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Marco Tana ◽  
Silvio di Carlo ◽  
Marcello Romano ◽  
Massimo Alessandri ◽  
Cosima Schiavone ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Fdg Pet ◽  
Correct Diagnosis ◽  
Pulmonary Sarcoidosis ◽  
High Resolution Computed Tomography ◽  
Inflammatory Conditions ◽  
Positron Emission ◽  
Pet Ct ◽  
Noncaseating Granulomas ◽  
Fdg Pet Ct

Background:18F-fluorodeoxyglucose positron emission tomography integrated with computed tomography (18-F-FDG-PET/CT) is getting wide consensus in the diagnosis and staging of neoplastic disorders and represents a useful tool in the assessment of various inflammatory conditions. </P><P> Discussion: Sarcoidosis is an uncommon disease characterized by the systemic formation of noncaseating granulomas. Lungs are the sites most often affected, and investigation with high resolution computed tomography and biopsy is essential to achieve a correct diagnosis. 18-F-FDGPET/ CT is effective in the assessment of pulmonary sarcoidosis by demonstrating pulmonary and extrathoracic involvement and findings correlate well with pulmonary function in patients affected.Conclusion:This review would illustrate the usefulness and limits of 18-F-FDG-PET/CT in the assessment of pulmonary sarcoidosis.

scholarly journals Quantitative analysis of myocardial metabolic heterogeneity is superior to visual assessment for the detection of active cardiac sarcoidosis by F-18 FDG PET-CT imaging

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
M Malik ◽  
M Yazdani ◽  
SM Gould ◽  
E Reyes
Keyword(s):  
Fdg Pet ◽  
Cardiac Sarcoidosis ◽  
Visual Assessment ◽  
Ct Imaging ◽  
Myocardial Inflammation ◽  
Fdg Uptake ◽  
Pet Ct ◽  
Metabolic Heterogeneity ◽  
Fdg Pet Ct

Abstract Funding Acknowledgements Type of funding sources: None. Background Myocardial inflammation may occur in the context of a multisystem disease such as sarcoidosis, adversely affecting prognosis. A definitive diagnosis of cardiac sarcoidosis (CS) is essential to implementing life-saving treatment but this is complicated by the invasive nature of endomyocardial biopsy (EMB) and its low accuracy. Positron emission tomography (PET) assists in diagnosis, which relies on visual interpretation of myocardial F-18 FDG uptake. The value of quantitative analysis and its application to clinical practice remain uncertain. Purpose To investigate the power of quantitative F-18 FDG PET-CT imaging analysis for detecting CS in patients with suspected disease. Methods All patients underwent F-18 FDG PET-CT after a 24-hour low-carbohydrate diet and 15-hour fasting as part of their diagnostic work-up for suspected cardiac inflammation. Cardiovascular magnetic resonance acted as gatekeeper to PET-CT in 8 of every 10 scans. Myocardial F-18 FDG uptake was assessed qualitatively and quantitatively using both manually drawn regions of interest and automatic polar maps to measure global and segmental standardised F-18 FDG uptake values (SUV).  The coefficient of variation (CoV) was calculated to determine uptake heterogeneity. To confirm diagnosis, follow-up data regarding disease progression, further testing and treatment were collected. To allow for sufficient follow-up time, the first 40 consecutive patients from a prospective registry (n= 214; Sep 2017-Jun 2020) were included. Results A comprehensive clinical picture was obtained successfully in 37 patients (median [IQR], 17 [13.5] months) and a final diagnosis of CS reached in 7 (disease prevalence, 19%). EMB was performed in 2 patients only while 3 underwent PPM/ICD implantation. Significant predictors of CS were fulfilment of Japanese Ministry of Health and Welfare criteria (Wald, 6.44; p = 0.01) and left ventricular dysfunction (Wald 6.72; p = 0.01). Qualitative F-18 FDG PET-CT had a high negative (95%) but low positive (45%) predictive value for CS (sensitivity, 83%; specificity, 77%). F-18 FDG SUV CoV was the strongest imaging predictor (Wald, 6.77; p = 0.009) and was significantly higher in CS than non-CS (CoV median [quartiles], 0.26 [0.21, 0.36] and 0.12 [0.11, 0.14] respectively; p = 0.004). As per ROC curve analysis (AUC, 0.84), a CoV threshold of 0.20 was highly specific (93%) and sensitive (86%) for CS. Conclusion In a referring population with a low prevalence of cardiac sarcoidosis, F-18 FDG PET-CT imaging is sensitive for the detection of myocardial inflammation with active disease unlikely in patients with a negative scan. Quantitative evaluation of metabolic heterogeneity within the myocardium provides a strong, independent marker of active disease and should be considered alongside visual assessment.

scholarly journals Pulmonary Findings of [18F]FDG PET/CT Images on Asymptomatic COVID-19 Patients

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 839
Author(s):  
Tzu-Chuan Ho ◽  
Chin-Chuan Chang ◽  
Hung-Pin Chan ◽  
Ying-Fong Huang ◽  
Yi-Ming Arthur Chen ◽  
...  
Keyword(s):  
Systematic Review ◽  
Fdg Pet ◽  
Standardized Uptake Value ◽  
Fdg Uptake ◽  
Asymptomatic Patients ◽  
Positron Emission ◽  
Pet Ct ◽  
18F Fdg ◽  
Maximal Standardized Uptake Value ◽  
Fdg Pet Ct

During the coronavirus disease 2019 (COVID-19) pandemic, several case studies demonstrated that many asymptomatic patients with COVID-19 underwent fluorine-18 fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) examination for various indications. However, there is a lack of literature to characterize the pattern of [18F]FDG PET/CT imaging on asymptomatic COVID-19 patients. Therefore, a systematic review to analyze the pulmonary findings of [18F]FDG PET/CT on asymptomatic COVID-19 patients was conducted. This systematic review was performed under the guidelines of PRISMA. PubMed, Medline, and Web of Science were used to search for articles for this review. Articles with the key words: “asymptomatic”, “COVID-19”, “[18F]FDG PET/CT”, and “nuclear medicine” were searched for from 1 January 2020 to 20 May 2021. Thirty asymptomatic patients with COVID-19 were included in the eighteen articles. These patients had a mean age of 62.25 ± 14.85 years (male: 67.71 ± 12.00; female: 56.79 ± 15.81). [18F]FDG-avid lung lesions were found in 93.33% (28/30) of total patients. The major lesion was [18F]FDG-avid multiple ground-glass opacities (GGOs) in the peripheral or subpleural region in bilateral lungs, followed by the consolidation. The intensity of [18F]FDG uptake in multiple GGOs was 5.605 ± 2.914 (range from 2 to 12) for maximal standardized uptake value (SUVmax). [18F]FDG-avid thoracic lymph nodes (LN) were observed in 40% (12/40) of the patients. They mostly appeared in both mediastinal and hilar regions with an SUVmax of 5.8 ± 2.93 (range from 2.5 to 9.6). The [18F]FDG uptake was observed in multiple GGOs, as well as in the mediastinal and hilar LNs. These are common patterns in PET/CT of asymptomatic patients with COVID-19.

POSITRON EMISSION TOMOGRAPHY WITH 18F -FDG IN THE DIAGNOSIS OF PROSTHETIC HEART VALVE ENDOCARDITIS

2021 ◽  
Vol 5 (1) ◽  
pp. 1151-1160
Author(s):  
A.S. Lukashevich ◽  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Fdg Pet ◽  
Prosthetic Heart Valve ◽  
Emission Tomography ◽  
Whole Body ◽  
Positron Emission ◽  
Pet Ct ◽  
18F Fdg ◽  
Fdg Pet Ct

Purpose. The purpose of the article is to evaluate the diagnostic significance of positron emission tomography / computed tomography with 18F -fluorodeoxyglucose (18F -FDG PET/CT) for the diagnosis of prosthetic endocarditis. Methods of research. The study included 82 patients with suspected prosthetic endocarditis in accordance with the criteria proposed by Duke University [1-5]. The patients received hospital treatment at the State Institution RSPC "Cardiology" from January 2016 to March 2021. The study was of a prospective, non-randomized, single-center cohort design. The duration of the monitor period was 12 months from the moment of patients’ inclusion in the study. Whole-body positron emission tomography / computed tomography (PET/CT) examinations were performed in 82 patients. 27 patients were selected for surgical treatment. Conservative treatment group included 16 patients. 27 patients were selected into the observation group, they were suspected to have prosthetic heart valve infection in the primary referral and underwent PET/CT scanning, according to which the diagnosis of prosthetic endocarditis was excluded. The event under the study did not develop in this group during the year of observation. Results and conclusion. The history of infective endocarditis was not statistically significant and did not increase the risk of developing prosthetic endocarditis in the sample presented. The Duke criteria are less reliable in establishing the diagnosis of prosthetic endocarditis. The median number of days from the date of the first prosthesis implantation to the onset of prosthetic endocarditis was about 4 years. This study revealed that the development of the infectious process in the area of the prosthesis was noted in a more distant postoperative period compared to literature data. Histological confirmation of infection was noted in 100% (27 patients) of cases in reoperated patients. The presence of a more formidable complication such as valve ring abscess located mainly in the projection of the aortic valve ring was quite common in both groups. Presepsin and Interleukin-6 have a statistically significant (U = 394,50 p = 0,01 and U = 94,50 p = 0.004) value in the prognosis of prosthetic endocarditis. Considering the data obtained from ROC analysis, it can be said that the cut-off point at which it is possible to diagnose prosthetic endocarditis based on PETCT is 2.85. The presented methods for the interpretation of whole-body FDG-PET/CT images of patients with suspected infectious complications after cardiac surgery, as well as with the presence of prosthetic endocarditis, show high sensitivity and specificity.

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