scholarly journals The utility of 18F-fluorodeoxyglucose positron emission tomography with computed tomography in Mycobacterium chimaera endocarditis: a case series

2019 ◽  
Vol 3 (4) ◽  
pp. 1-6 ◽  
Author(s):  
Mohamed Dafaalla ◽  
Nicholas Weight ◽  
Verran Cajic ◽  
Uday Dandekar ◽  
Kishore Gopalakrishnan ◽  
...  

Abstract Background Infective endocarditis secondary to Mycobacterium chimaera can present with classical constitutional symptoms of infective endocarditis but can be blood culture negative and without vegetations on transthoracic or transoesophageal echocardiogram. Patients with prosthetic valves are at particularly high risk. Case summary We present two patients who were diagnosed with infective endocarditis secondary to M. chimaera infection. They presented similarly with pyrexia of unknown origin and night sweats. Both patients had previously undergone aortic valve replacement; one with a tissue valve and the other with a metallic valve. New cardiac murmurs were evident on auscultation, but clinical examination showed no peripheral stigmata of endocarditis. Transoesophageal echo and transthoracic echo were both unremarkable, as were serial blood cultures. FDG PET CT scan was the key investigation, which showed increased uptake in the spleen beside other areas. Histopathology and mycobacterial cultures confirmed the diagnosis of M. chimaera infection in both cases. The first patient completed medical therapy and is now fit and well. However, the second patient unfortunately developed disseminated infection causing death. Discussion The management of M. chimaera infective endocarditis is challenging, often with delayed diagnosis and poor outcomes. In the context of negative blood cultures and inconclusive echocardiograms where there remains a high index of suspicion for endocarditis, FDG PET CT scanning can be a crucial diagnostic importance and should be considered early in patients with prosthetic valves.

2021 ◽  
Vol 23 (9) ◽  
Author(s):  
D. ten Hove ◽  
R.H.J.A. Slart ◽  
B. Sinha ◽  
A.W.J.M. Glaudemans ◽  
R.P.J. Budde

Abstract Purpose of Review Additional imaging modalities, such as FDG-PET/CT, have been included into the workup for patients with suspected infective endocarditis, according to major international guidelines published in 2015. The purpose of this review is to give an overview of FDG-PET/CT indications and standardized approaches in the setting of suspected infective endocarditis. Recent Findings There are two main indications for performing FDG-PET/CT in patients with suspected infective endocarditis: (i) detecting intracardiac infections and (ii) detection of (clinically silent) disseminated infectious disease. The diagnostic performance of FDG-PET/CT for intracardiac lesions depends on the presence of native valves, prosthetic valves, or implanted cardiac devices, with a sensitivity that is poor for native valve endocarditis and cardiac device-related lead infections, but much better for prosthetic valve endocarditis and cardiac device-related pocket infections. Specificity is high for all these indications. The detection of disseminated disease may also help establish the diagnosis and/or impact patient management. Summary Based on current evidence, FDG-PET/CT should be considered for detection of disseminated disease in suspected endocarditis. Absence of intracardiac lesions on FDG-PET/CT cannot rule out native valve endocarditis, but positive findings strongly support the diagnosis. For prosthetic valve endocarditis, standard use of FDG-PET/CT is recommended because of its high sensitivity and specificity. For implanted cardiac devices, FDG-PET/CT is also recommended, but should be evaluated with careful attention to clinical context, because its sensitivity is high for pocket infections, but low for lead infections. In patients with prosthetic valves with or without additional aortic prosthesis, combination with CTA should be considered. Optimal timing of FDG-PET/CT is important, both during clinical workup and technically (i.e., post tracer injection). In addition, procedural standardization is key and encompasses patient preparation, scan acquisition, reconstruction, subsequent analysis, and clinical interpretation. The recommendations discussed here will hopefully contribute to improved standardization and enhanced performance of FDG-PET/CT in the clinical management of patients with suspected infective endocarditis.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Fabio Chirillo ◽  
Franco Boccaletto ◽  
Paola Pantano ◽  
Alessandro De Leo ◽  
Marta Possamai ◽  
...  

The diagnosis of infective endocarditis (IE) is sometimes difficult when there are discrepancies between blood cultures, transesophageal echocardiography (TEE) and clinical judgment. The aim of this study was to assess the incremental diagnostic value of 18 F-FDG-PET/CT in 45 consecutive patients (73% male, mean age 61 ± 26 years) with suspected IE and inconclusive tests at admission. In 28 patients (19 with a cardiac valvular (15) or nonvalvular (4) device) with blood cultures positive for germs typically involved in IE the initial TEE was negative or inconclusive. In 10 patients presenting with fever TEE identified cardiac lesion possibly related to IE (ruptured mitral chordae, thickened valve leaflet, thickened prosthetic annulus), but blood cultures were persistently negative. Finally, 7 patients had metastatic or embolic lesions and a predisposing cardiac condition, but TEE was negative. When previous unknown lesions detected by PET/CT were confirmed by succeeding examinations, they were considered true positives. When PET/CT was negative, it was compared with the final diagnosis that was defined according to the modified Duke criteria determined during a 6-month follow-up. Thirty patients had definite IE at the end of the follow-up, 3 had possible IE, and in 12 patients the diagnosis was rejected. Twenty-seven patients (60%) exhibited abnormal FDG uptake around the cardiac valves, and 12 (27%) had extracardiac accumulation. In 5 patients the initial negative TEE became positive a mean 5 ±7 days after PET/CT had been performed The sensitivity, specificity, positive predictive value, and negative predictive value of PET/CT were as follows (95% confidence interval): 87% (68% to 95%), 67% (38% to 87%), 84% (65% to 94%), and 71% (42% to 92%), respectively. Adding abnormal FDG uptake as a new major criterion significantly increased the sensitivity of the modified Duke criteria at admission (68% [53% to 82%] vs. 96% [88% to 99%], p = 0.01). This result was due to a significant reduction (p < 0.001) in the number of possible IE cases. In conclusion PET/CT increases the diagnostic accuracy for IE in the subset of patients with possible IE and may help to manage a challenging situation.


2017 ◽  
Vol 77 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Verena Schönau ◽  
Kristin Vogel ◽  
Matthias Englbrecht ◽  
Jochen Wacker ◽  
Daniela Schmidt ◽  
...  

BackgroundFever of unknown origin (FUO) and inflammation of unknown origin (IUO) are diagnostically challenging conditions. Diagnosis of underlying disease may be improved by 18F-fluorodesoxyglucose positron emission tomography (18F-FDG-PET).MethodsProspective study to test diagnostic utility of 18F-FDG-PET/CT in a large cohort of patients with FUO or IUO and to define parameters that increase the likelihood of diagnostic 18F-FDG-PET/CT. Patients with FUO or IUO received 18F-FDG-PET/CT scanning in addition to standard diagnostic work-up. 18F-FDG-PET/CT results were classified as helpful or non-helpful in establishing final diagnosis. Binary logistic regression was used to identify clinical parameters associated with a diagnostic 18F-FDG-PET/CT.Results240 patients were enrolled, 72 with FUO, 142 with IUO and 26 had FUO or IUO previously (exFUO/IUO). Diagnosis was established in 190 patients (79.2%). The leading diagnoses were adult-onset Still’s disease (15.3%) in the FUO group, large vessel vasculitis (21.1%) and polymyalgia rheumatica (18.3%) in the IUO group and IgG4-related disease (15.4%) in the exFUO/IUO group. In 136 patients (56.7% of all patients and 71.6% of patients with a diagnosis), 18F-FDG-PET/CT was positive and helpful in finding the diagnosis. Predictive markers for a diagnostic 18F-FDG-PET/CT were age over 50 years (p=0.019), C-reactive protein (CRP) level over 30 mg/L (p=0.002) and absence of fever (p=0.001).Conclusion18F-FDG-PET/CT scanning is helpful in ascertaining the correct diagnosis in more than 50% of the cases presenting with FUO and IUO. Absence of intermittent fever, higher age and elevated CRP level increase the likelihood for a diagnostic 18F-FDG-PET/CT.


Author(s):  
A. Jiménez-Ballvé ◽  
M.J. Pérez-Castejón ◽  
C. Sánchez-Enrique ◽  
I. Vilacosta ◽  
L. Lapeña-Gutiérrez ◽  
...  

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Donghe Chen ◽  
Chengdong Chang ◽  
Ming Chen ◽  
Yafei Zhang ◽  
Xin Zhao ◽  
...  

Abstract Background Talaromyces marneffei infection is an important opportunistic infection associated with acquired immune deficiency syndrome (AIDS). However, it is unusual in patients with non-AIDS and other non-immunosuppressed conditions. We report a case of delayed diagnosis of disseminated T. marneffei infection in non-AIDS, non-immunosuppressive and non-endemic conditions. Case presentation We describe a previously healthy 24-year-old man who complained of a 3-month history of intermittent diarrhea and a recent week of uncontrollable high fever. The HIV antibody test was negative. Enhanced abdominal computed tomography (CT) and integrated 18F-2-deoxy-2-fluoro-D-glucose position emission tomography/computed tomography (FDG PET/CT) both suspected malignant lymphoma. However, a large number of yeast-like cells were found in macrophages in cervical lymph node samples by hematoxylin and eosin stain and silver hexamine stain. Subsequent blood culture suggested T. marneffei infection. Metagenomic Next Generation Sequencing (mNGS) results suggested T. marneffei as the dominant pathogen. Unfortunately, the patient continued to develop acute liver failure and died due to adverse events associated with amphotericin B. Conclusions Early diagnosis in HIV-negative patients who are otherwise not immunosuppressed and endemic poses a serious challenge. T. marneffei infection is an FDG-avid nonmalignant condition that may lead to false-positive FDG PET/CT scans. Nevertheless, integrated FDG PET/CT is necessary in patients with fever of unknown origin in the early period to perform earlier biopsy for histopathology and culture in highly avid sites and to avoid delays in diagnosis and treatment.


Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Jordy P. Pijl ◽  
Mark Londema ◽  
Thomas C. Kwee ◽  
Maarten W. N. Nijsten ◽  
Riemer H. J. A. Slart ◽  
...  

Abstract Background 2-Deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) is an advanced imaging technique that can be used to examine the whole body for an infection focus in a single examination in patients with bloodstream infection (BSI) of unknown origin. However, literature on the use of this technique in intensive care patients is scarce. The purpose of this study was to evaluate the diagnostic yield of FDG-PET/CT in intensive care patients with BSI. Methods In this retrospective cohort study, all intensive care patients from our Dutch university medical center who had culture-proven BSI between 2010 and 2020 and underwent FDG-PET/CT to find the focus of infection were included. Diagnostic performance was calculated and logistic regression analysis was performed to evaluate the association between FDG-PET/CT outcome and C-reactive protein level (CRP), leukocyte count, duration of antibiotic treatment, duration of ICU stay, quality of FDG-PET/CT, and dependency on mechanical ventilation. In addition, the impact of FDG-PET/CT on clinical treatment was evaluated. Results 30 intensive care patients with BSI were included. In 21 patients, an infection focus was found on FDG-PET/CT which led to changes in clinical management in 14 patients. FDG-PET/CT achieved a sensitivity of 90.9% and specificity of 87.5% for identifying the focus of infection. Poor quality of the FDG-PET images significantly decreased the likelihood of finding an infection focus as compared to reasonable or good image quality (OR 0.16, P = 0.034). No other variables were significantly associated with FDG-PET/CT outcome. No adverse events during the FDG-PET/CT procedure were reported. Conclusion FDG-PET/CT has a high diagnostic yield for detecting the infection focus in patients with BSI admitted to intensive care. Poor PET image quality was significantly associated with a decreased likelihood of finding the infection focus in patients with BSI. This could be improved by adequate dietary preparation and cessation of intravenous glucose and glucose-regulating drugs. Recent advances in PET/CT technology enable higher image quality with shorter imaging time and may contribute to routinely performing FDG-PET/CT in intensive care patients with BSI of unknown origin.


Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 720
Author(s):  
Valentin Pretet ◽  
Cyrille Blondet ◽  
Yvon Ruch ◽  
Matias Martinez ◽  
Soraya El Ghannudi ◽  
...  

According to European Society of Cardiology guidelines (ESC2015) for infective endocarditis (IE) management, modified Duke criteria (mDC) are implemented with a degree of clinical suspicion degree, leading to grades such as “possible” or “rejected” IE despite a persisting high level of clinical suspicion. Herein, we evaluate the 18F-FDG PET/CT diagnostic and therapeutic impact in IE suspicion, with emphasis on possible/rejected IE with a high clinical suspicion. Excluding cases of definite IE diagnosis, 53 patients who underwent 18F-FDG PET/CT for IE suspicion were selected and afterwards classified according to both mDC (possible IE/Duke 1, rejected IE/Duke 0) and clinical suspicion degree (high and low IE suspicion). The final status regarding IE diagnosis (gold standard) was based on the multidisciplinary decision of the Endocarditis Team, including the ‘imaging specialist’. PET/CT images of the cardiac area were qualitatively interpreted and the intensity of each focus of extra-physiologic 18F-FDG uptake was evaluated by a maximum standardized uptake value (SUVmax) measurement. Extra-cardiac 18F-FDG PET/CT pathological findings were considered to be a possible embolic event, a possible source of IE, or even a concomitant infection. Based on the Endocarditis Team consensus, final diagnosis of IE was retained in 19 (36%) patients and excluded in 34 (64%). With a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and global accuracy of 79%, 100%, 100%, 89%, and 92%, respectively, PET/CT performed significantly better than mDC (p = 0.003), clinical suspicion degree (p = 0.001), and a combination of both (p = 0.001) for IE diagnosis. In 41 patients with possible/rejected IE but high clinical suspicion, sensitivity, specificity, PPV, NPV, and global accuracies were 78%, 100%, 100%, 85%, and 90%, respectively. Moreover, PET/CT contributed to patient management in 24 out of 53 (45%) cases. 18F-FDG PET/CT represents a valuable diagnostic tool that could be proposed for challenging IE cases with significant differences between mDC and clinical suspicion degree. 18F-FDG PET/CT allows a binary diagnosis (definite or rejected IE) by removing uncertain diagnostic situations, thus improving patient therapeutic management.


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