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1.
Eur J Nucl Med Mol Imaging ; 50(1): 90-102, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1999921

ABSTRACT

PURPOSE: We evaluated brain metabolic dysfunctions and associations with neurological and biological parameters in acute, subacute and chronic COVID-19 phases to provide deeper insights into the pathophysiology of the disease. METHODS: Twenty-six patients with neurological symptoms (neuro-COVID-19) and [18F]FDG-PET were included. Seven patients were acute (< 1 month (m) after onset), 12 subacute (4 ≥ 1-m, 4 ≥ 2-m and 4 ≥ 3-m) and 7 with neuro-post-COVID-19 (3 ≥ 5-m and 4 ≥ 7-9-m). One patient was evaluated longitudinally (acute and 5-m). Brain hypo- and hypermetabolism were analysed at single-subject and group levels. Correlations between severity/extent of brain hypo- and hypermetabolism and biological (oxygen saturation and C-reactive protein) and clinical variables (global cognition and Body Mass Index) were assessed. RESULTS: The "fronto-insular cortex" emerged as the hypometabolic hallmark of neuro-COVID-19. Acute patients showed the most severe hypometabolism affecting several cortical regions. Three-m and 5-m patients showed a progressive reduction of hypometabolism, with limited frontal clusters. After 7-9 months, no brain hypometabolism was detected. The patient evaluated longitudinally showed a diffuse brain hypometabolism in the acute phase, almost recovered after 5 months. Brain hypometabolism correlated with cognitive dysfunction, low blood saturation and high inflammatory status. Hypermetabolism in the brainstem, cerebellum, hippocampus and amygdala persisted over time and correlated with inflammation status. CONCLUSION: Synergistic effects of systemic virus-mediated inflammation and transient hypoxia yield a dysfunction of the fronto-insular cortex, a signature of CNS involvement in neuro-COVID-19. This brain dysfunction is likely to be transient and almost reversible. The long-lasting brain hypermetabolism seems to reflect persistent inflammation processes.


Subject(s)
COVID-19 , Positron-Emission Tomography , Humans , COVID-19/diagnostic imaging , Fluorodeoxyglucose F18/metabolism , Brain/diagnostic imaging , Brain/metabolism , Inflammation/metabolism
3.
J Nucl Med ; 63(7): 1058-1063, 2022 07.
Article in English | MEDLINE | ID: covidwho-1923992

ABSTRACT

During the coronavirus disease 2019 (COVID-19) pandemic, Long COVID syndrome, which impairs patients through cognitive deficits, fatigue, and exhaustion, has become increasingly relevant. Its underlying pathophysiology, however, is unknown. In this study, we assessed cognitive profiles and regional cerebral glucose metabolism as a biomarker of neuronal function in outpatients with long-term neurocognitive symptoms after COVID-19. Methods: Outpatients seeking neurologic counseling with neurocognitive symptoms persisting for more than 3 mo after polymerase chain reaction (PCR)-confirmed COVID-19 were included prospectively between June 16, 2020, and January 29, 2021. Patients (n = 31; age, 53.6 ± 2.0 y) in the long-term phase after COVID-19 (202 ± 58 d after positive PCR) were assessed with a neuropsychologic test battery. Cerebral 18F-FDG PET imaging was performed in 14 of 31 patients. Results: Patients self-reported impaired attention, memory, and multitasking abilities (31/31), word-finding difficulties (27/31), and fatigue (24/31). Twelve of 31 patients could not return to the previous level of independence/employment. For all cognitive domains, average group results of the neuropsychologic test battery showed no impairment, but deficits (z score < -1.5) were present on a single-patient level mainly in the domain of visual memory (in 7/31; other domains ≤ 2/31). Mean Montreal Cognitive Assessment performance (27/30 points) was above the cutoff value for detection of cognitive impairment (<26 points), although 9 of 31 patients performed slightly below this level (23-25 points). In the subgroup of patients who underwent 18F-FDG PET, we found no significant changes of regional cerebral glucose metabolism. Conclusion: Long COVID patients self-report uniform symptoms hampering their ability to work in a relevant fraction. However, cognitive testing showed minor impairments only on a single-patient level approximately 6 mo after the infection, whereas functional imaging revealed no distinct pathologic changes. This clearly deviates from previous findings in subacute COVID-19 patients, suggesting that underlying neuronal causes are different and possibly related to the high prevalence of fatigue.


Subject(s)
COVID-19 , Cerebrum , Glucose , COVID-19/complications , COVID-19/psychology , Cerebrum/metabolism , Fatigue , Fluorodeoxyglucose F18/metabolism , Glucose/metabolism , Humans , Middle Aged , Neuropsychological Tests , Positron-Emission Tomography
4.
Int J Mol Sci ; 23(9)2022 Apr 28.
Article in English | MEDLINE | ID: covidwho-1847341

ABSTRACT

Obesity is a leading cause of preventable death and morbidity. To elucidate the mechanisms connecting metabolically active brown adipose tissue (BAT) and metabolic health may provide insights into methods of treatment for obesity-related conditions. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FDG-PET/CT) is traditionally used to image human BAT activity. However, the primary energy source of BAT is derived from intracellular fatty acids and not glucose. Beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) is a fatty acid analogue amenable to in vivo imaging by single photon emission computed tomography/CT (SPECT/CT) when radiolabeled with iodine isotopes. In this study, we compare the use of 18FDG-PET/CT and 125I-BMIPP-SPECT/CT for fat imaging to ascertain whether BMIPP is a more robust candidate for the non-invasive evaluation of metabolically active adipose depots. Interscapular BAT, inguinal white adipose tissue (iWAT), and gonadal white adipose tissue (gWAT) uptake of 18FDG and 125I-BMIPP was quantified in mice following treatment with the BAT-stimulating drug CL-316,243 or saline vehicle control. After CL-316,243 treatment, uptake of both radiotracers increased in BAT and iWAT. The standard uptake value (SUVmean) for 18FDG and 125I-BMIPP significantly correlated in these depots, although uptake of 125I-BMIPP in BAT and iWAT more closely mimicked the fold-change in metabolic rate as measured by an extracellular flux analyzer. Herein, we find that imaging BAT with the radioiodinated fatty acid analogue BMIPP yields more physiologically relevant data than 18FDG-PET/CT, and its conventional use may be a pivotal tool for evaluating BAT in both mice and humans.


Subject(s)
Adipose Tissue, Brown , Fluorodeoxyglucose F18 , Adipose Tissue, Brown/diagnostic imaging , Adipose Tissue, Brown/metabolism , Animals , Fatty Acids/metabolism , Fluorodeoxyglucose F18/metabolism , Iodobenzenes , Mice , Obesity/metabolism , Positron Emission Tomography Computed Tomography , Positron-Emission Tomography , Radiopharmaceuticals/metabolism , Tomography, Emission-Computed, Single-Photon/methods
5.
Clin Nucl Med ; 47(8): 712-713, 2022 Aug 01.
Article in English | MEDLINE | ID: covidwho-1779008

ABSTRACT

ABSTRACT: In an attempt to protect the high-risk demographic and reduce burden on health care systems, concomitant administration of COVID-19 and influenza vaccines has been recommended by health bodies. The ComFluCOV trial indicates this is well tolerated with no reduction in immune response to either vaccine. A 48-year-old woman with right oropharyngeal squamous cell carcinoma underwent postradiotherapy FDG PET/CT, which demonstrated complete metabolic response. Incidental avid bilateral axillary lymphadenopathy of benign configuration was noted and concluded to be reactive in response to recent Pfizer-BioNTech booster and influenza vaccination. This is expected to be seen more frequently over the coming months.


Subject(s)
COVID-19 , Influenza, Human , COVID-19/prevention & control , Female , Fluorodeoxyglucose F18/metabolism , Humans , Influenza, Human/metabolism , Influenza, Human/pathology , Influenza, Human/prevention & control , Lymph Nodes/pathology , Middle Aged , Positron Emission Tomography Computed Tomography , Seasons , Vaccination
6.
Eur J Nucl Med Mol Imaging ; 49(9): 3197-3202, 2022 07.
Article in English | MEDLINE | ID: covidwho-1756789

ABSTRACT

BACKGROUND: This multicentre study aimed to provide a qualitative and consensual description of brain hypometabolism observed through the visual analysis of 18F-FDG PET images of patients with suspected neurological long COVID, regarding the previously reported long-COVID hypometabolic pattern involving hypometabolism in the olfactory bulbs and other limbic/paralimbic regions, as well as in the brainstem and cerebellum. METHODS: From the beginning of August 2021 to the end of October 2021, the brain 18F-FDG PET scans of patients referred for suspected neurological long COVID with positive reverse transcription polymerase chain reaction (RT-PCR) and/or serology tests for SARS-CoV-2 infection were retrospectively reviewed in three French nuclear medicine departments (143 patients; 47.4 years old ± 13.6; 98 women). Experienced nuclear physicians from each department classified brain 18F-FDG PET scans according to the same visual interpretation analysis as being normal, mildly to moderately (or incompletely) affected, or otherwise severely affected within the previously reported long-COVID hypometabolic pattern. RESULTS: On the 143 brain 18F-FDG PET scans performed during this 3-month period, 53% of the scans were visually interpreted as normal, 21% as mildly to moderately or incompletely affected, and 26% as severely affected according to the COVID hypometabolic pattern. On average, PET scans were performed at 10.9 months from symptom onset (± 4.8). Importantly, this specific hypometabolic pattern was similarly identified in the three nuclear medicine departments. Typical illustrative examples are provided to help nuclear physicians interpret long-COVID profiles. CONCLUSION: The proposed PET metabolic pattern is easily identified upon visual interpretation in clinical routine for approximately one half of patients with suspected neurological long COVID, requiring special consideration for frontobasal paramedian regions, the brainstem and the cerebellum, and certainly further adapted follow-up and medical care, while the second half of patients have normal brain PET metabolism on average 10.9 months from symptom onset.


Subject(s)
COVID-19 , Fluorodeoxyglucose F18 , Brain/diagnostic imaging , Brain/metabolism , COVID-19/complications , COVID-19/diagnostic imaging , Female , Fluorodeoxyglucose F18/metabolism , Humans , Middle Aged , Positron-Emission Tomography/methods , Radiopharmaceuticals/metabolism , Retrospective Studies , SARS-CoV-2
7.
Ann Nucl Med ; 35(11): 1264-1269, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1378991

ABSTRACT

BACKGROUND: mRNA COVID-19 vaccines are known to provide an immune response seen on FDG PET studies. However, the time course of this metabolic response is unknown. We here present a temporal metabolic response to mRNA COVID-19 vaccination in oncology patients undergoing standard of care FDG PET. METHODS: 262 oncology patients undergoing standard of care FDG PET were included in the analysis. 231 patients had at least one dose of mRNA COVID-19 vaccine while 31 patients had not been vaccinated. The SUVmax of the lymph nodes ipsilateral to the vaccination was compared to the contralateral to obtain an absolute change in SUVmax (ΔSUVmax). RESULTS: ΔSUVmax was more significant at shorter times between FDG PET imaging and COVID-19 mRNA vaccination, with a median ΔSUVmax of 2.6 (0-7 days), 0.8 (8-14 days), and 0.3 (> 14 days), respectively. CONCLUSION: Consideration should be given to performing FDG PET at least 2 weeks after the COVID-19 vaccine.


Subject(s)
COVID-19 Vaccines/immunology , Neoplasms/immunology , Neoplasms/metabolism , Vaccines, Synthetic/immunology , Adult , Aged , Aged, 80 and over , Axilla , COVID-19/prevention & control , COVID-19 Vaccines/administration & dosage , Female , Fluorodeoxyglucose F18/metabolism , Humans , Lymph Nodes/diagnostic imaging , Lymph Nodes/immunology , Lymph Nodes/metabolism , Male , Middle Aged , Pectoralis Muscles , Positron Emission Tomography Computed Tomography , Time Factors , Vaccines, Synthetic/administration & dosage
8.
Cancer Treat Rev ; 98: 102220, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1275253

ABSTRACT

As the world embarks on mass vaccination for COVID-19, we are beginning to encounter unintended dilemmas in imaging oncology patients; particularly with regards to FDG PET/CT. In some cases, vaccine-related lymphadenopathy and FDG uptake on PET/CT can mimic cancer and lead to confounding imaging results. These cases where findings overlap with cancer pose a significant dilemma for diagnostic purposes, follow-up, and management leading to possible treatment delays, unnecessary repeat imaging and sampling, and patient anxiety. These cases can largely be avoided by optimal coordination between vaccination and planned imaging as well as preemptive selection of vaccine administration site. This coordination hinges on patient, oncologist, and radiologists' awareness of this issue and collaboration. Through close communication and patient education, we believe this will eliminate significant challenges for our oncology patients as we strive to end this pandemic.


Subject(s)
COVID-19 Vaccines/adverse effects , COVID-19/prevention & control , Lymphadenopathy/diagnosis , Neoplasms/diagnosis , Positron Emission Tomography Computed Tomography/standards , Vaccination/adverse effects , COVID-19/virology , Diagnosis, Differential , Disease Progression , Fluorodeoxyglucose F18/metabolism , Humans , Lymphadenopathy/chemically induced , Lymphadenopathy/diagnostic imaging , Neoplasms/chemically induced , Neoplasms/diagnostic imaging , Radiopharmaceuticals/metabolism , SARS-CoV-2/isolation & purification
9.
Clin Nucl Med ; 46(5): 439-441, 2021 May 01.
Article in English | MEDLINE | ID: covidwho-1116483

ABSTRACT

ABSTRACT: We present a case of increased FDG uptake in the lymph nodes after COVID-19 vaccine administration. Restaging PET/CT scan of a 70-year-old woman with a history of multiple relapsed Hodgkin lymphoma showed muscle activity in the left upper arm laterally, which is in the deep musculature of the left deltoid muscle. There was also increased activity in several normal-sized left axillary nodes as well. On further review of the patient's history, she had received her second shot of the Pfizer-BioNTech COVID-19 vaccine approximately 2 days before the restaging PET/CT scan.


Subject(s)
COVID-19 Vaccines/adverse effects , Fluorodeoxyglucose F18/metabolism , Aged , Axilla , Female , Humans , Lymph Nodes/diagnostic imaging , Lymph Nodes/immunology , Lymph Nodes/metabolism , Positron Emission Tomography Computed Tomography
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