Bivalent mRNA COVID-19 Vaccine-Related Pericarditis on 18 F-FDG PET/CT.

ABSTRACT: A 13-year-old boy was suspected with pericarditis after a second booster dose of bivalent mRNA COVID-19 vaccine. After specific preparation for cardiac inflammation with carbohydrate-free, high-fat diet, the 18 F-FDG PET/CT successfully demonstrated simultaneous presentation of vaccination-related axillary lymphadenopathy and pericarditis without the interference of physiological myocardial uptake.

COVID-19 vaccine related hypermetabolic lymph nodes on PET/CT: Implications of inflammatory findings in cancer imaging.

We observed several patients presenting 2-[18F]FDG uptake in the reactive axillary lymph node at PET/CT imaging, ipsilateral to the site of the COVID-19 vaccine injection. Analog finding was documented at [18F]Choline PET/CT. The aim of our study was to describe this source of false positive cases. All patients examined by PET/CT were included in the study. Data concerning patient anamnesis, laterality, and time interval from recent COVID-19 vaccination were recorded. SUVmax was measured in all lymph nodes expressing tracer uptake after vaccination. Among 712 PET/CT scans with 2-[18F]FDG, 104 were submitted to vaccination; 89/104 patients (85%) presented axillary and/or deltoid tracer uptake, related to recent COVID-19 vaccine administration (median from injection: 11 days). The mean SUVmax of these findings was 2.1 (range 1.6-3.3). Among 89 patients with false positive axillary uptake, 36 subjects had received chemotherapy due to lymph node metastases from somatic cancer or lymphomas, prior to the scan: 6/36 patients with lymph node metastases showed no response to therapy or progression disease. The mean SUVmax value of lymph nodal localizations of somatic cancers/lymphomas after chemotherapy was 7.8. Only 1/31 prostate cancer patients examined by [18F]Choline PET/CT showed post-vaccine axillary lymph node uptake. These findings were not recorded at PET/CT scans with [18F]-6-FDOPA, [68Ga]Ga-DOTATOC, and [18F]-fluoride. Following COVID-19 mass vaccination, a significant percentage of patients examined by 2-[18F]FDG PET/CT presents axillary, reactive lymph node uptake. Anamnesis, low-dose CT, and ultrasonography facilitated correct diagnosis. Semi-quantitative assessment supported the visual analysis of PET/CT data; SUVmax values of metastatic lymph nodes were considerably higher than post-vaccine lymph nodes. [18F]Choline uptake in reactive lymph node after vaccination was confirmed. After the COVID-19 pandemic, nuclear physicians need to take these potential false positive cases into account in daily clinical practice.

A Spectrum of Disease: Breast Implant-Associated Anaplastic Large Cell Lymphoma, Atypicals, and Other Implant Associations.

Breast implant associated anaplastic large cell lymphoma (BIA-ALCL) is an uncommon and emerging malignancy caused by textured breast implants. The most common patient presentation is delayed seromas, other presentations include breast asymmetry, overlying skin rashes, palpable masses, lymphadenopathy, and capsular contracture. Confirmed diagnoses should receive lymphoma oncology consultation, multidisciplinary evaluation, and PET-CT or CT scan evaluation prior to surgical treatment. Disease confined to the capsule is curable in the majority of patients with complete surgical resection. BIA-ALCL is now recognized as one disease among a spectrum of inflammatory mediated malignancies which include implant-associated squamous cell carcinoma and B cell lymphoma.

The role of PET/CT in thyroid autoimmune diseases.

Autoimmune thyroid diseases (AITD) are a heterogeneous group of disorders. They include, in particular, Graves' disease and Hashimoto's thyroiditis with a wide range of different functional status ranging from subclinical biochemical abnormalities to severe hyperthyroidism or severe hypothyroidism respectively. Furthermore, other conditions more frequently infectious or drug related can cause an immune reaction in the thyroid tissue. In AITDs, positron emission tomography/computed tomography (PET/CT) does not play a primary role for disease diagnosis or management, but accidental findings can occur in both symptomatic and asymptomatic patients, and they should be recognized and well interpreted. A comprehensive literature search of the PubMed databases was conducted to identify papers (systematic review, prospective and retrospective study, case report) evaluating the role of PET/CT in thyroid autoimmune diseases. Thyroid diffuse uptake of 18F-fluoro-2-deoxy-2-d-glucose ([18F]FDG) has been shown to be frequently associated with AITDs, but also with immune-induced thyroid disorders related to SARS-CoV-2 or immunotherapy, while malignant lesions more often have a focal aspect. Other radiopharmaceuticals as [68Ga]-DOTA-peptides, [68Ga]-fibroblast activation protein inhibitors (FAPIs) and [68Ga]-prostate specific membrane antigen ([68Ga]-PSMA) showed similar findings. In conclusion, PET/CT scan in AITDs does not play a primary role in the diagnosis, but the occasional finding of a thyroid uptake must always be described in the report and possibly investigated for a better patient's management.

A case report of hepatic angiomyolipoma, inflammatory subtype. Clinico-pathological characterization: a diagnostic challenge.

BACKGROUND: Angiomyolipoma is a benign mesenchymal neoplasm of a wide histological heterogeneity belonging to the PEComa "family." The liver, after the kidney, is their second most frequent location. However, inflammatory hepatic AMLs constitute a rare entity, with only fourteen documented cases until 2020. These neoplasms can overlap morphological features of IgG4-related diseases, being of great diagnostic relevance to demonstrating myomelanocytic-lineage differentiation of the neoplastic cells. CASE PRESENTATION: we present a new case of an inflammatory hepatic AML resembling an IgG4-related disease in a 35-year-old woman with a subcapsular 5 cm mass confined to segment VII of the right hepatic lobe. Although having reduced its size along the tumor's natural evolution, complete tumor resection was decided due to its hypermetabolic behavior (max. SUV = 12,6) assessed by PET-CT scan. Finally, the patient underwent a right hepatectomy due to spontaneous rupture and bleeding of the lesion during the intervention. All the diagnostic and therapeutic procedures occurred in the last months of the COVID-19 pandemic. CONCLUSIONS: This review aims to describe inflammatory hepatic AML histological and immunohistochemical features. We further sought to establish a clinicopathological contextualization of this tumoral subtype.

COVID-19: Findings in nuclear medicine from head to toe.

COVID-19 is a multisystemic disease, and hence its potential manifestations on nuclear medicine imaging can extend beyond the lung. Therefore, it is important for the nuclear medicine physician to recognize these manifestations in the clinic. While FDG-PET/CT is not indicated routinely in COVID-19 evaluation, its unique capability to provide a functional and anatomical assessment of the entire body means that it can be a powerful tool to monitor acute, subacute, and long-term effects of COVID-19. Single-photon scintigraphy is routinely used to assess conditions such as pulmonary embolism, cardiac ischemia, and thyroiditis, and COVID-19 may present in these studies. The most common nuclear imaging finding of COVID-19 vaccination to date is hypermetabolic axillary lymphadenopathy. This may pose important diagnostic and management dilemmas in oncologic patients, particularly those with malignancies where the axilla constitutes a lymphatic drainage area. This article aims to summarize the relevant literature published since the beginning of the pandemic on the intersection between COVID-19 and nuclear medicine.

Post-COVID-19 Brain [18F] FDG-PET Findings: A Retrospective Single-Center Study in the United States.

BACKGROUND AND PURPOSE: The pathophysiology of neurologic manifestations of postacute sequelae of Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection is not clearly understood. Our aim was to investigate brain metabolic activity on [18F] FDG-PET/CT scans in patients with a history of coronavirus disease 2019 (COVID-19) infection before imaging. MATERIALS AND METHODS: This retrospective study included 45 patients who underwent [18F] FDG-PET/CT imaging for any reason and had, at least once, tested positive for COVID-19 at any time before imaging. Fifteen patients had available [18F] FDG-PET scans obtained under identical conditions before the infection. A group of 52 patients with melanoma or multiple myeloma who underwent [18F] FDG-PET/CT were used as controls. Whole-brain 2-sample t test analysis was performed using SPM software to identify clusters of hypo- and hypermetabolism and compare brain metabolic activity between patients with COVID-19 and controls. Paired sample t test comparison was also performed for 15 patients, and correlations between metabolic values of clusters and clinical data were measured. RESULTS: Compared with the control group, patients with a history of COVID-19 infection exhibited focal areas of hypometabolism in the bilateral frontal, parietal, occipital, and posterior temporal lobes and cerebellum (P = .05 uncorrected at the voxel level, family-wise error-corrected at the cluster level) that peaked during the first 2 months, improved to near-complete recovery around 6 months, and disappeared at 12 months. Hypermetabolism involving the brainstem, cerebellum, limbic structures, frontal cortex, and periventricular white matter was observed only at 2-6 months after infection. Older age, neurologic symptoms, and worse disease severity scores positively correlated with the metabolic changes. CONCLUSIONS: This study demonstrates a profile of time-dependent brain PET hypo- and hypermetabolism in patients with confirmed SARS-CoV-2 infection.

Longitudinal analyses using 18F-Fluorodeoxyglucose positron emission tomography with computed tomography as a measure of COVID-19 severity in the aged, young, and humanized ACE2 SARS-CoV-2 hamster models.

This study compared disease progression of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in three different models of golden hamsters: aged (≈60 weeks old) wild-type (WT), young (6 weeks old) WT, and adult (14-22 weeks old) hamsters expressing the human-angiotensin-converting enzyme 2 (hACE2) receptor. After intranasal (IN) exposure to the SARS-CoV-2 Washington isolate (WA01/2020), 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography with computed tomography (18F-FDG PET/CT) was used to monitor disease progression in near real time and animals were euthanized at pre-determined time points to directly compare imaging findings with other disease parameters associated with coronavirus disease 2019 (COVID-19). Consistent with histopathology, 18F-FDG-PET/CT demonstrated that aged WT hamsters exposed to 105 plaque forming units (PFU) developed more severe and protracted pneumonia than young WT hamsters exposed to the same (or lower) dose or hACE2 hamsters exposed to a uniformly lethal dose of virus. Specifically, aged WT hamsters presented with a severe interstitial pneumonia through 8 d post-exposure (PE), while pulmonary regeneration was observed in young WT hamsters at that time. hACE2 hamsters exposed to 100 or 10 PFU virus presented with a minimal to mild hemorrhagic pneumonia but succumbed to SARS-CoV-2-related meningoencephalitis by 6 d PE, suggesting that this model might allow assessment of SARS-CoV-2 infection on the central nervous system (CNS). Our group is the first to use (18F-FDG) PET/CT to differentiate respiratory disease severity ranging from mild to severe in three COVID-19 hamster models. The non-invasive, serial measure of disease progression provided by PET/CT makes it a valuable tool for animal model characterization.

[11C]metomidate PET-CT versus adrenal vein sampling for diagnosing surgically curable primary aldosteronism: a prospective, within-patient trial.

Primary aldosteronism (PA) due to a unilateral aldosterone-producing adenoma is a common cause of hypertension. This can be cured, or greatly improved, by adrenal surgery. However, the invasive nature of the standard pre-surgical investigation contributes to fewer than 1% of patients with PA being offered the chance of a cure. The primary objective of our prospective study of 143 patients with PA ( NCT02945904 ) was to compare the accuracy of a non-invasive test, [11C]metomidate positron emission tomography computed tomography (MTO) scanning, with adrenal vein sampling (AVS) in predicting the biochemical remission of PA and the resolution of hypertension after surgery. A total of 128 patients reached 6- to 9-month follow-up, with 78 (61%) treated surgically and 50 (39%) managed medically. Of the 78 patients receiving surgery, 77 achieved one or more PA surgical outcome criterion for success. The accuracies of MTO at predicting biochemical and clinical success following adrenalectomy were, respectively, 72.7 and 65.4%. For AVS, the accuracies were 63.6 and 61.5%. MTO was not significantly superior, but the differences of 9.1% (95% confidence interval = -6.5 to 24.1%) and 3.8% (95% confidence interval = -11.9 to 9.4) lay within the pre-specified -17% margin for non-inferiority (P = 0.00055 and P = 0.0077, respectively). Of 24 serious adverse events, none was considered related to either investigation and 22 were fully resolved. MTO enables non-invasive diagnosis of unilateral PA.

[Global and national trends in the evolution of infective endocarditis].

For the recent 20 years, substantial changes have occurred in all aspects of infectious endocarditis (IE), the evolution of risk factors, modernization of diagnostic methods, therapeutic and preventive approaches. The global trends are characterized by increased IE morbidity among people older than 65 who use intravenous psychoactive drugs. The epidemiological trend is represented by reduced roles of chronic rheumatic heart disease and congenital heart defects, increased proportion of IE associated with medical care, valve replacement, installation of intracardiac devices, and increased contribution of Staphylococcus spp. and Enterococcus spp. to the IE etiology. Additional visualization methods (fluorodeoxyglucose positron emission tomography with 18F-fludesoxyglucose (18F-FDG PET-CT), labeled white blood cell single-photon emission computed tomography (SPECT), and modernization of the etiological diagnostic algorithm for determining the true pathogen (immunochemistry, polymerase chain reaction, sequencing) also become increasingly important. The COVID-19 pandemic has also adversely contributed to the IE epidemiology. New prospects of treatment have emerged, such as bacteriophages, lysins, oral antibacterial therapy, minimally invasive surgical strategies (percutaneous mechanical aspiration), endovascular mechanical embolectomy. The physicians' compliance with clinical guidelines (CG) is low, which contributes to the high rate of adverse outcomes of IE, while simple adherence to the CG together with more frequent use of surgical treatment doubles survival. Systematic adherence to CG, timely prevention and implementation of the Endocarditis Team into practice play the decisive role in a favorable prognosis of dynamically changing IE. This article presents the authors' own data that confirm the evolutionary trends of current IE.

Investigating the potential added value of [ 18 F]FDG-PET/CT in long COVID patients with persistent symptoms: a proof of concept study.

OBJECTIVE: Since the end of 2019, the coronavirus disease 2019 (COVID-19) virus has infected millions of people, of whom a significant group suffers from sequelae from COVID-19, termed long COVID. As more and more patients emerge with long COVID who have symptoms of fatigue, myalgia and joint pain, we must examine potential biomarkers to find quantifiable parameters to define the underlying mechanisms and enable response monitoring. The aim of this study is to investigate the potential added value of [ 18 F]FDG-PET/computed tomography (CT) for this group of long COVID patients. METHODS: For this proof of concept study, we evaluated [ 18 F]FDG-PET/CT scans of long COVID patients and controls. Two analyses were performed: semi-quantitative analysis using target-to-background ratios (TBRs) in 24 targets and total vascular score (TVS) assessed by two independent nuclear medicine physicians. Mann-Whitney U -test was performed to find significant differences between the two groups. RESULTS: Thirteen patients were included in the long COVID group and 25 patients were included in the control group. No significant differences ( P  < 0.05) were found between the long COVID group and the control group in the TBR or TVS assessment. CONCLUSION: As we found no quantitative difference in the TBR or TVS between long COVID patients and controls, we are unable to prove that [ 18 F]FDG is of added value for long COVID patients with symptoms of myalgia or joint pain. Prospective cohort studies are necessary to understand the underlying mechanisms of long COVID.

Imaging Fibrosis.

Tissue injury in nonmalignant human disease can develop from either disproportionate inflammation or exaggerated fibrotic responses. The molecular and cellular fundamental of these 2 processes, their impact on disease prognosis and the treatment concept deviates fundamentally. Consequently, the synchronous assessment and quantification of these 2 processes in vivo is extremely desirable. Although noninvasive molecular techniques such as 18F-fluorodeoxyglucose PET offer insights into the degree of inflammatory activity, the assessment of the molecular dynamics of fibrosis remains challenging. The 68Ga-fibroblast activation protein inhibitor-46 may improve noninvasive clinical diagnostic performance in patients with both fibroinflammatory pathology and long-term CT-abnormalities after severe COVID-19.

Incidence of incidental positron emission tomography and computed tomography signs of COVID-19 in asymptomatic cancer patients in Egypt.

Background: COVID-19 was first reported in Egypt on 14 February 2020 and continues to be a major threat to public health. Aims: We studied the incidence of incidental positron emission tomography/computed tomography (PET/CT) signs of COVID-19 in asymptomatic cancer patients and compared this with the number of reported COVID-19 cases during the same period. Methods: We included all cancer patients who underwent PET/CT at Misr Radiology Center, Cairo, between 2 May and 7 August 2020. Results: There were 479 patients who underwent PET/CT primarily for follow-up, and 66 (13.78%) of them showed radiological signs of COVID-19, with the peak incidence in weeks 7-8 of the study. This coincided and strongly correlated with the peak incidence of COVID-19 in Egypt (Pearson's correlation coefficient test = 0.943). Conclusion: The incidence of incidental PET/CT signs of COVID-19 was in accordance with the officially reported incidence of COVID-19 in Egypt between 2 May and 7 August 2020. These results could be helpful for implementing and adjusting public health and social measures during the COVID-19 pandemic.

18F-Fluciclovine-Avid Axillary Lymph Nodes After COVID-19 Vaccination on PET/CT for Suspected Recurrence of Prostate Cancer.

Abnormally increased 18F-FDG avidity of axillary lymph nodes has become a frequent diagnostic dilemma on PET/CT in the current climate of global vaccinations directed against severe acute respiratory syndrome coronavirus 2. This avidity is due to the inflammatory response evoked by vaccines and the nonspecific nature of 18F-FDG uptake, which is increased in both malignant and inflammatory processes. Similarly, 18F-fluciclovine, an amino acid analog indicated for the assessment of biochemical recurrence of prostate cancer, may also demonstrate nonspecific inflammatory uptake. We report a case of 18F-fluciclovine PET/CT obtained for concern about prostate cancer. In this case, isolated avid lymph nodes were seen in the left axilla. A screening questionnaire revealed that the patient had recently received the second dose of the Pfizer-BioNTech coronavirus disease 2019 vaccine in his left shoulder, and hence, the uptake was determined to be reactive.

Systemic lupus erythematosus myocarditis after COVID-19 vaccination.

INTRODUCTION: Cases of acute myocarditis have been after administration of the BNT162b2 and Ad26.COV2.S vaccine. OBJECTIVE: Describe another possible mechanism of myocarditis after COVID-19 vaccination. CASE PRESENTATION: We describe the clinical case of a 72-year-old female with pleuritic chest pain one week after the third of the BNT162b2 mRNA vaccine. Serological tests for cardiotropic pathogens were negative, and autoimmunity screening was positive with anti-nuclear antibody (ANA) in 1:160 dilution, Anti-double-stranded DNA (anti-dsDNA), and anti-histone antibodies. 18F-fluoro-deoxy-glucose (FDG) positron emission tomography/computed tomography (PET/CT) showed a focal myocardial and pericardial inflammatory process in the cardiac apex. RESULTS AND DISCUSSION: Systemic lupus erythematosus (SLE) diagnosis was made with myocardial affection. As far as we know, this is the first report of a case of lupus myocarditis after the COVID-19 vaccine. CONCLUSION: Given the pathogenic rationales, the association between SLE and myocarditis should be considered.

Bilateral Lymphadenopathy After COVID Vaccine in 18F-Choline PET/MRI Performed for Hyperparathyroidism.

ABSTRACT: We describe a case of a 56-year-old woman with primary hyperparathyroidism. 18F-Choline PET/MRI revealed incidental bilateral axillary lymphadenopathy with mild-moderate increased 18F-choline uptake. The patient had her first and third doses of COVID-19 vaccines from the left arm and second dose of vaccine from the right arm before PET examination.