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Background: Vascular calcification is an established feature of atherosclerosis process. The sodium/phosphate transporter PiT-1 acts as a biosensor in vascular calcification of VSMCs. [ 99m Tc]-Pentavalent dimercaptosuccinic acid ( 99m Tc-(V)-DMSA) was mediated by PiT-1 transporter in tumoral cells and we propose its evaluation in a vascular calcification in vitro model. The aim of this study was to determine if 99m Tc-(V)-DMSA can follow the vascular calcification process in vascular smooth muscle cells (VSMCs) based on PiT-1 expression., Methods: From a rat aortic VSMC cell line (A7r5), we set up a model of calcification within 7 days using a calcifying medium containing a high inorganic phosphate concentration. Phosphocalcic deposits were monitored with Alizarin red and Von Kossa staining and with phase contrast microscopy. PiT-1 expression was evaluated with an immunofluorescence assay and osteopontin expression, with whole cell ELISA assay. 99m Tc-(V)-DMSA uptake was measured in control and calcifying conditions and compared with optical microscopy evaluation., Results: Under hyperphosphatemia conditions, the VSMC cells progressively overexpressed osteopontin protein, PiT-1 transporter, and synthetized mineralized matrix with phosphocalcic deposition. 99m Tc-(V)-DMSA uptake was to 2.8±2.08%DA/mg-protein in control cells and 42±24%DA/mg-protein in calcified cells (P<0.001). PiT-1 inhibition with phosphonoformic acid completely reverse the calcium deposition as well as the 99m Tc-(V)-DMSA uptake. These results demonstrated that 99m Tc-(V)-DMSA in-vitro uptake is mediated by PiT-1 transporter and follow the VSMC calcification process., Conclusions: These preliminary in-vitro results showed 99m Tc-(V)-DMSA uptake follow the phospho-calcic deposition mediated by PiT-1 transporter. This radiotracer may have some potential to detect changes of VSMC metabolism occurring in the atherosclerosis process.

Abstract: Increased muscle uptake is commonly seen with 18 F-FDG PET/CT because of an important physiological muscle glucose metabolism. Muscle uptake can express a recent significant muscle activity. However, the absence of muscle uptake is almost never described or interpreted. We describe the case of an 8-year-old boy with extrarenal rhabdoid tumor in the right carotid space. An MRI and an 18 F-FDG PET/CT were performed for the diagnostic workup. There was no uptake in the lateral rectus oculomotor muscle unlike all other oculomotor muscles. The ophthalmological examination found a diplopia confirmed by the Lancaster test., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: [ 18 F]Fluorocholine positron emission tomography/computed tomography (PET/CT) is used frequently in addition to [ 99m Tc]Tc-Sestamibi scintigraphy and ultrasonography for the location of hyperfunctioning parathyroid glands. The aim of this study is to evaluate the performance of quantitative criteria in [ 18 F]fluorocholine PET/CT for localization of hyperfunctioning parathyroid glands. The secondary objective is to highlight a correlation between the detection rate of [ 18 F]fluorocholine PET/CT and serum parathyroid hormone (PTH) level., Materials and Methods: In two academic centers, we retrospectively included patients with biological hyperparathyroidism (HPT) and who had [ 18 F]fluorocholine PET/CT. After a visual analysis, to measure the overall performance of [ 18 F]fluorocholine PET/CT, a blind reading was carried out with standardized measurements of maximum standardized uptake value (SUV max ), liver ratio, thyroid ratio, and size ratio. We analyzed the quantitative criteria of [ 18 F]fluorocholine PET/CT compared to the histological results, in particular to identify differences between adenomas and hyperplasias. We compared the performance of each quantitative criterion to the overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of [ 18 F]fluorocholine PET/CT. The detection rate of hyperfunctioning parathyroid glands was calculated in subgroups of serum PTH level., Results: The quantitative criteria in [ 18 F]fluorocholine PET/CT were measured for 120 patients (135 lesions). The areas under the receiver operating characteristic (ROC) curve representing SUV max and liver ratio were significantly increased. The optimal cut-off values represented by the maximum Youden index was >4.12 for SUV max and >27.4 for liver ratio. Beyond certain threshold values of SUV max (>4.12) or liver ratio (>38.1), all the lesions were histologically proven adenomas. SUV max and liver ratio were significantly higher for adenomas than for hyperplasias and differential diagnosis ( p = 0.0085 and p = 0.0002). The positivity of [ 18 F]fluorocholine PET/CT was correlated with PTH level. Detection rates were 55.56, 75.56, and 87.5%, respectively, for serum PTH < 70, 70 to 120, and >120 ng/ml., Conclusion: Semi-quantitative measurements (SUV max and liver ratio) should be considered as additional tools in interpretation of [ 18 F]fluorocholine PET/CT. These quantitative parameters have lower overall performance but higher specificity than overall visual analysis in identifying an adenoma. Above certain threshold values, all lesions are adenomas. [ 18 F]fluorocholine PET/CT confirms excellent performance for the detection of hyperfunctional parathyroids. For serum PTH levels < 70 ng/ml, the detection rate of [ 18 F]fluorocholine PET/CT is strongly decreased., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Jacquet-Francillon, Morelec, Germain, Prades, Habouzit, Mariat, Bonnefoy and Prevot.)

Background: Cadmium-zinc-telluride (CZT) SPECT/CT cameras with large field of view offer a higher sensitivity than conventional Anger cameras. This prospective study aimed to determine the equivalence between a conventional protocol and a reduced acquisition time protocol for 201-Thallium myocardial perfusion imaging (MPI) using a whole-body CZT SPECT camera., Methods and Results: Stress MPI was obtained for 103 consecutive patients on a DISCOVERY-CZT camera. Images were anonymized and post-processed to simulate a 25% (D75 dataset) and 50% (D50 dataset) decrease in total recorded counts. Concerning the number of segments displaying a tracer uptake < 70% of maximum intensity per patient, equivalence was demonstrated for both count-reduced datasets with a good inter-observer agreement (between 0.90 and 0.88). When comparing the full-vs-D75 datasets and full-vs-D50 datasets, mean difference was 0.06 segment (CI95: [- 0.15;0.27], P < 0.001) and 0.518 segment (CI95: [0.28;0.76], P < 0.001) respectively. Inter-observer agreement was also moderate to good concerning the number of pathological segments (between 0.6 and 0.7) and excellent for functional parameters., Conclusion: Whole-body CZT SPECT/CT cameras allow to reduce 201-Thallium MPI injected activity or acquisition time by 50% with an equivalence in the number of segments displaying a tracer uptake < 70% of maximum intensity and with a good inter-observer agreement., (© 2021. American Society of Nuclear Cardiology.)

Purpose: In coronavirus disease 2019 (COVID-19) patients, clinical manifestations as well as chest CT lesions are variable. Lung scintigraphy allows to assess and compare the regional distribution of ventilation and perfusion throughout the lungs. Our main objective was to describe ventilation and perfusion injury by type of chest CT lesions of COVID-19 infection using V/Q SPECT/CT imaging., Patients and Methods: We explored a national registry including V/Q SPECT/CT performed during a proven acute SARS-CoV-2 infection. Chest CT findings of COVID-19 disease were classified in 3 elementary lesions: ground-glass opacities, crazy-paving (CP), and consolidation. For each type of chest CT lesions, a semiquantitative evaluation of ventilation and perfusion was visually performed using a 5-point scale score (0 = normal to 4 = absent function)., Results: V/Q SPECT/CT was performed in 145 patients recruited in 9 nuclear medicine departments. Parenchymal lesions were visible in 126 patients (86.9%). Ground-glass opacities were visible in 33 patients (22.8%) and were responsible for minimal perfusion impairment (perfusion score [mean ± SD], 0.9 ± 0.6) and moderate ventilation impairment (ventilation score, 1.7 ± 1); CP was visible in 43 patients (29.7%) and caused moderate perfusion impairment (2.1 ± 1.1) and moderate-to-severe ventilation impairment (2.5 ± 1.1); consolidation was visible in 89 patients (61.4%) and was associated with moderate perfusion impairment (2.1 ± 1) and severe ventilation impairment (3.0 ± 0.9)., Conclusions: In COVID-19 patients assessed with V/Q SPECT/CT, a large proportion demonstrated parenchymal lung lesions on CT, responsible for ventilation and perfusion injury. COVID-19-related pulmonary lesions were, in order of frequency and functional impairment, consolidations, CP, and ground-glass opacity, with typically a reverse mismatched or matched pattern., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

In patients with novel coronavirus disease 2019 (COVID-19) referred for lung scintigraphy because of suspected pulmonary embolism (PE), there has been an ongoing debate within the nuclear medicine community as to whether and when the ventilation imaging should be performed. Indeed, whereas PE diagnosis typically relies on the recognition of ventilation-perfusion (V/P) mismatched defects, the ventilation procedure potentially increases the risk of contamination to health-care workers. The primary aim of this study was to assess the role of ventilation imaging when lung scintigraphy is performed because of suspected PE in COVID-19 patients. The secondary aim was to describe practices and imaging findings in this specific population. Methods: A national registry was created in collaboration with the French Society of Nuclear Medicine to collect lung scans performed on COVID-19 patients for suspected PE. The practices of departments were assessed regarding imaging protocols and aerosol precautions. A retrospective review of V/P SPECT/CT scans was then conducted. Two physicians masked to clinical information reviewed each case by sequentially viewing perfusion SPECT, perfusion SPECT/CT, and V/P SPECT/CT images. The scans were classified into 1 of the 4 following categories: patients for whom PE could reasonably be excluded on the basis of perfusion SPECT only, perfusion SPECT/CT, or V/P SPECT/CT and patients with mismatched defects suggestive of PE according to the European Association of Nuclear Medicine criteria. Results: Data from 12 French nuclear medicine departments were collected. Lung scans were performed between March 2020 and April 2021. Personal protective equipment and dedicated cleaning procedures were used in all departments. Of the 145 V/Q SPECT/CT scans included in the central review, PE could be excluded using only perfusion SPECT, perfusion SPECT/CT, or V/P SPECT/CT in 27 (19%), 55 (38%), and 45 (31%) patients, respectively. V/P SPECT/CT was positive for PE in 18 (12%) patients, including 12 (67%) with a low burden of PE (≤10%). Conclusion: In this population of COVID-19 patients assessed with lung scintigraphy, PE could confidently be excluded without the ventilation imaging in only 57% of patients. Ventilation imaging was required to confidently rule out PE in 31% of patients. Overall, the prevalence of PE was low (12%)., (© 2022 by the Society of Nuclear Medicine and Molecular Imaging.)

Ventilation/perfusion (V/Q) imaging and computed tomography pulmonary angiography (CTPA) are common tools for acute pulmonary embolism (PE) diagnosis. Limited contemporary data exist about the utilization of each modality, including the predictors of using V/Q versus CTPA. We used the data from patients diagnosed with PE using V/Q or CTPA from 2007 to 2019 in Registro Informatizado Enfermedad ThromboEmbolica, an international prospective registry of patients with venous thromboembolism. Outcomes was to determine the trends in utilization of V/Q vs. CTPA and, in a contemporary subgroup fitting with current practices, to evaluate predictors of V/Q use with multivariable logistic regression. Among 26,540 patients with PE, 89.2% were diagnosed with CTPA, 7.1% with V/Q and 3.7% with > 1 thoracic imaging modality. Over time, the proportional use of V/Q scanning declined (13.9 to 3.3%, P < 0.001). In multivariable analysis, heart failure history (odds ratio [OR]:1.5; 95% confidence interval [CI] 1.14-1.98), diabetes ([OR 1.71; 95% CI 1.39-2.10]), moderate and severe renal failure (respectively [OR 1.87; 95% CI 1.47-2.38] and [OR 9.36; 95% CI 6.98-12.55]) were the patient-level predictors of V/Q utilization. We also observed an influence of geographical and institutional factors, partly explained by time-limited V/Q availability (less use over weekends) and regional practices. Use of V/Q for the diagnosis of PE decreased over time, but it still has an important role in specific situations with an influence of patient-related, institution-related and logistical factors. Local and regional resources should be evaluated to improve V/Q accessibility than could benefit for this population., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Promyelocytic sarcoma is an uncommon solid tumor made up of myeloblasts. It is characterized, like acute promyelocytic leukemia (APL), by a chromosomal translocation t(15;17) involving the retinoic acid receptor alpha (RARalpha) and the promyelocytic gene (PML). The diagnosis and monitoring of promyelocytic sarcoma is a challenge due to the rarity and severity of the disease. We describe a case with several initial sites and without APL. The patient was monitored with regular 18F-FDG PET/CT from diagnosis to complete response. The evolution of PET/CT imageries was compared to the quantification of PML-RARα fusion gene by RQ-PCR. In promyelocytic sarcoma medical care, 18F-FDG PET/CT appears to be an attractive tool for finding targets for biopsy, for the primary staging, for assessing therapeutic response and for detecting early relapse., (Copyright © 2020. Published by Elsevier Masson SAS.)

Abstract: Giant cell arteritis is not an uncommon disease, and its extension is furthermore finely assessed with new-generation PET/CT system. 18F-FDG PET/CT is increasingly used in case of large-vessel vasculitis for optimal diagnosis, activity monitoring (even when treated with interleukin 6 receptor inhibitor), and evaluation damage progression. We reported the case of a 61-year-old woman with common giant cell arteritis pattern on 18F-FDG PET/CT (aorta and large arteries) and uptakes in all aorta branches, mainly impressive and uncommon in the abdomen. After 2 years of therapeutic optimization including IV tocilizumab and monitoring with 18F-FDG PET/CT, a complete metabolical response was assessed., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The phenotype of patients seen for a suspicion of pulmonary hypertension has changed, with an increasing age and frequency of comorbidities. Selection of elderly patients, in whom a classical work-up is mandatory, is challenging. Comprehensive geriatric assessment (CGA) has modified the management of elderly patients with cancer. Pulmonary hypertension (PH) shares with cancer a functional impact and may evolve rapidly, depending on the group of PH. We assessed the impact of a systematic CGA in patients over 70 years old referred for a suspicion of PH., Methods: A standardised CGA was performed on every patient older than 70 years old, referred for a PH suspicion, before considering invasive tests for diagnosis and treatment, between July 2014 and May 2019. Our primary aim was to describe the impact of CGA on the decision to stop or pursue the recommended diagnostic work-up for PH., Results: Among the thirty-one patients evaluated [mean age 81,5 (72-91) years], a negative CGA leads to stop the diagnostic work-up in eleven patients. Among the nineteen remaining patients, sixteen had confirmed PH, with half being chronic thromboembolic pulmonary hypertension., Conclusions: Our study indicates that comprehensive geriatric assessment could be an excellent first screen for elderly patients referred for a PH suspicion. Involving a geriatric physician stopped the investigations in one third of patients. In patients with a favourable CGA, PH was confirmed in most of the cases, with chronic thromboembolic pulmonary hypertension being the first cause of PH., (Copyright © 2020 SPLF and Elsevier Masson SAS. All rights reserved.)

We report the case of an asymptomatic (no fever, no cough, no dyspnea) 80-year-old woman who had an F-FDG PET/CT scan for initial staging of Lieberkühnian adenocarcinoma located on anal canal. Chest analysis incidentally revealed bilateral diffuse patchy ground-glass opacity with mild increasing F-FDG uptake, consistent with incidental COVID-19 infection finding during the March 2020 pandemic. The infection was confirmed by reverse transcription-polymerase chain reaction. It led us to improve patient flow and to undertake broader measures to avoid patient clinical issues and potential disease spreading.

Surviving an embolism exposes patients to potential long-term complications, such as altered quality of life, persistent dyspnea, impaired exercise capacity or pulmonary hypertension. The common objective factor in most of these situations is the presence of residual pulmonary vascular obstruction (RPVO). Planar ventilation/perfusion scintigraphy (V/Q lung scan) is the gold standard for assessing RPVO, which occurs in 46 to 66% of patients at 3 months and persists in 25 to 29% of patients a year after acute PE. Assessed early (i.e. before discharge), RPVO could predict acute PE development with a high negative predictive value. Evaluated after anticoagulation therapy, RPVO could help to manage anticoagulation treatment and predict the risk of PE recurrence and patients identified at risk of developing chronic thromboembolic pulmonary hypertension. In this comprehensive review, we provide an overview of the current knowledge of RPVO after PE from imaging diagnosis to clinical consequences. In the first part, we mainly focus on the imaging modalities capable of detecting and quantifying RPVO. We then focus on the symptoms and syndromes linked with this residual obstruction after PE. Although the occurrence of RPVO and long-term complications varies greatly from one patient to another, we finally aim to identify the patients and diseases at risk of developing residual obstruction., (Copyright © 2019 Elsevier Ltd. All rights reserved.)