A 75-year-old diabetic man with a cardiac history of pacemaker implantation and mechanical prosthetic valve (PV) replacement, also known for chronic osteitis of the first left metatarsophalangeal joint (MTP I), was treated with oral antibiotic on an outpatient basis with poor compliance when he developed intermittent fever (39.8°C) and left foot pain. Laboratory testing revealed a slight elevation of the white blood cell count (10.7 G/L) and a significant elevation of the C-reactive protein (235 mg/L). Hemocultures turned positive for multi-sensitive Staphylococcus aureus and Proteus mirabilis. A left foot CT showed MTP I osteoarthritis without collection. Transoesophageal echocardiography (TOE) showed no evidence of endocarditis. A double antibiotic regimen was started, but the patient developed persistent fever. Repeated TOE raised endocarditis suspicion. Because of a newly developed cough, a search for respiratory pathogens was performed and turned positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. An 18 F-FDG PET/CT was requested for investigating the suspicion of PV infection with a 72-h low-carbohydrate diet preparation.The 18 F-FDG PET maximum-intensity projection image shows (a) bilateral metabolic lung lesions, the foot infection (*), and one metabolically active draining sentinel lymph node (arrowhead). (b) Free-breathing lung CT and 18 F-FDG with hypermetabolic (SUV max 7.6 g/mL) focal ground-glass opacities with partial consolidation and mild bronchial dilatation with a peripheral distribution in the subpleural and periscissural regions of the apical and posterior segments of both upper lobes and right middle lobe, as previously described on CT [1]. (c) Hypermetabolic lymphadenopathies in the right lower paratracheal, subcarinal, and bilateral hilar stations (SUV max 6.

Respiratory motion negatively affects PET/CT image quality and quantitation. A novel Pulsatile-Flow Ventilation (PFV) system reducing respiratory motion was applied in spontaneously breathing patients to induce sustained apnea during PET/CT. Methods: Four patients (aged 65 ± 14 y) underwent PET/CT for pulmonary nodule staging (mean, 11 ± 7 mm; range, 5-18 mm) at 63 ± 3 min after 18 F-FDG injection and then at 47 ± 7 min afterward, during PFV-induced apnea (with imaging lasting $8.5 min). Anterior-posterior thoracic amplitude, SUV max , and SUV peak (SUV mean in a 1-cm-diameter sphere) were compared. Results: PFV PET/CT reduced thoracic amplitude (80%), increased mean lesion SUV max (29%) and SUV peak (11%), decreased lung background SUV peak (25%), improved lesion detectability, and increased SUV peak lesion-to-background ratio (54%). On linear regressions, SUV max and SUV peak significantly improved (by 35% and 23%, respectively; P # 0.02). Conclusion: PFV-induced apnea reduces thoracic organ motion and increases lesion SUV, detectability, and delineation, thus potentially affecting patient management by improving diagnosis, prognostication, monitoring, and external-radiation therapy planning.

ImportanceAmyloid positron emission tomography (PET) allows the direct assessment of amyloid deposition, one of the main hallmarks of Alzheimer disease. However, this technique is currently not widely reimbursed because of the lack of appropriately designed studies demonstrating its clinical effect.ObjectiveTo assess the clinical effect of amyloid PET in memory clinic patients.Design, Setting, and ParticipantsThe AMYPAD-DPMS is a prospective randomized clinical trial in 8 European memory clinics. Participants were allocated (using a minimization method) to 3 study groups based on the performance of amyloid PET: arm 1, early in the diagnostic workup (within 1 month); arm 2, late in the diagnostic workup (after a mean [SD] 8 [2] months); or arm 3, if and when the managing physician chose. Participants were patients with subjective cognitive decline plus (SCD+; SCD plus clinical features increasing the likelihood of preclinical Alzheimer disease), mild cognitive impairment (MCI), or dementia; they were assessed at baseline and after 3 months. Recruitment took place between April 16, 2018, and October 30, 2020. Data analysis was performed from July 2022 to January 2023.InterventionAmyloid PET.Main Outcome and MeasureThe main outcome was the difference between arm 1 and arm 2 in the proportion of participants receiving an etiological diagnosis with a very high confidence (ie, ≥90% on a 50%-100% visual numeric scale) after 3 months.ResultsA total of 844 participants were screened, and 840 were enrolled (291 in arm 1, 271 in arm 2, 278 in arm 3). Baseline and 3-month visit data were available for 272 participants in arm 1 and 260 in arm 2 (median [IQR] age: 71 [65-77] and 71 [65-77] years; 150/272 male [55%] and 135/260 male [52%]; 122/272 female [45%] and 125/260 female [48%]; median [IQR] education: 12 [10-15] and 13 [10-16] years, respectively). After 3 months, 109 of 272 participants (40%) in arm 1 had a diagnosis with very high confidence vs 30 of 260 (11%) in arm 2 (P < .001). This was consistent across cognitive stages (SCD+: 25/84 [30%] vs 5/78 [6%]; P < .001; MCI: 45/108 [42%] vs 9/102 [9%]; P < .001; dementia: 39/80 [49%] vs 16/80 [20%]; P < .001).Conclusion and RelevanceIn this study, early amyloid PET allowed memory clinic patients to receive an etiological diagnosis with very high confidence after only 3 months compared with patients who had not undergone amyloid PET. These findings support the implementation of amyloid PET early in the diagnostic workup of memory clinic patients.Trial RegistrationEudraCT Number: 2017-002527-21