Phantom studies have shown improved lesion detection performance with time-of-flight (TOF) PET. In this study, we evaluate the benefit of fully 3-dimensional, TOF PET in clinical whole-body oncology ...using human observers to localize and detect lesions in realistic patient anatomic backgrounds. Our hypothesis is that with TOF imaging we achieve improved lesion detection and localization for clinically challenging tasks, with a bigger impact in large patients.
One hundred patient studies with normal (18)F-FDG uptake were chosen. Spheres (diameter, 10 mm) were imaged in air at variable locations in the scanner field of view corresponding to lung and liver locations within each patient. Sphere data were corrected for attenuation and merged with patient data to produce fused list-mode data files with lesions added to normal-uptake scans. All list files were reconstructed with full corrections and with or without the TOF kernel using a list-mode iterative algorithm. The images were presented to readers to localize and report the presence or absence of a lesion and their confidence level. The interpretation results were then analyzed to calculate the probability of correct localization and detection, and the area under the localized receiver operating characteristic (LROC) curve. The results were analyzed as a function of scan time per bed position, patient body mass index (BMI < 26 and BMI ≥ 26), and type of imaging (TOF and non-TOF).
Our results showed that longer scan times led to an improved area under the LROC curve for all patient sizes. With TOF imaging, there was a bigger increase in the area under the LROC curve for larger patients (BMI ≥ 26). Finally, we saw smaller differences in the area under the LROC curve for large and small patients when longer scan times were combined with TOF imaging.
A combination of longer scan time (3 min in this study) and TOF imaging provides the best performance for imaging large patients or a low-uptake lesion in small or large patients. This imaging protocol also provides similar performance for all patient sizes for lesions in the same organ type with similar relative uptake, indicating an ability to provide a uniform clinical diagnosis in most oncologic lesion detection tasks.
Venous thromboembolism (VTE), which encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE), is a significant cause of morbidity and mortality worldwide. There are many factors, both ...acquired and inherited, known to increase the risk of VTE. Most of these result in increased risk via several common mechanisms including circulatory stasis, endothelial damage, or increased hypercoagulability. Overall, a risk factor can be identified in the majority of patients with VTE; however, not all risk factors carry the same predictive value. It is important for clinicians to understand the potency of each individual risk factor when managing patients who have a VTE or are at risk of developing VTE. With this, many providers consider performing a thrombophilia evaluation to further define a patient's risk. However, guidance on who to test and when to test is controversial and not always clear. This comprehensive review attempts to address these aspects/concerns by providing an overview of the multifaceted risk factors associated with VTE as well as examining the role of performing a thrombophilia evaluation, including the indications and timing of performing such an evaluation.
ATPase family AAA-domain containing protein 3A (ATAD3A) is a nuclear-encoded mitochondrial membrane protein implicated in mitochondrial dynamics, nucleoid organization, protein translation, cell ...growth, and cholesterol metabolism. We identified a recurrent de novo ATAD3A c.1582C>T (p.Arg528Trp) variant by whole-exome sequencing (WES) in five unrelated individuals with a core phenotype of global developmental delay, hypotonia, optic atrophy, axonal neuropathy, and hypertrophic cardiomyopathy. We also describe two families with biallelic variants in ATAD3A, including a homozygous variant in two siblings, and biallelic ATAD3A deletions mediated by nonallelic homologous recombination (NAHR) between ATAD3A and gene family members ATAD3B and ATAD3C. Tissue-specific overexpression of borR534W, the Drosophila mutation homologous to the human c.1582C>T (p.Arg528Trp) variant, resulted in a dramatic decrease in mitochondrial content, aberrant mitochondrial morphology, and increased autophagy. Homozygous null bor larvae showed a significant decrease of mitochondria, while overexpression of borWT resulted in larger, elongated mitochondria. Finally, fibroblasts of an affected individual exhibited increased mitophagy. We conclude that the p.Arg528Trp variant functions through a dominant-negative mechanism that results in small mitochondria that trigger mitophagy, resulting in a reduction in mitochondrial content. ATAD3A variation represents an additional link between mitochondrial dynamics and recognizable neurological syndromes, as seen with MFN2, OPA1, DNM1L, and STAT2 mutations.
Phantom studies have shown improved lesion detection performance with time-of-flight (TOF) PET. In this study we evaluate the benefit of fully-3D, TOF PET in clinical whole-body oncology using human ...observers to localize and detect lesions in realistic patient anatomic backgrounds. Our hypothesis is that with TOF imaging we achieve improved lesion detection and localization for clinically challenging tasks with a bigger impact in large patients.
Introduction
Since 2019, Lebanon is experiencing an unprecedented exodus of doctors, seriously threatening the national health system, which is expected to continue without quick and effective ...solutions. Therefore, this study aimed to understand the factors that push Lebanese doctors to migrate and the factors that retain others in the country. Additionally, this study aims to propose solutions to preserve an adequate supply of medical care amidst the crisis.
Methods
Qualitative semi-structured interviews and focus group discussions were conducted using pre-developed guides. Purposive and snowball sampling was adopted to recruit physicians who emigrated and physicians staying in Lebanon. Transcripts of interviews and focus groups were coded using Dedoose software and analyzed through a combination of inductive and deductive approaches.
Results
Emigration was found to be the result of numerous interconnected factors. The main drivers for emigration were declining income, career problems, reduced quality of care, unhealthy work environment, and the deteriorated political and socio-economic contexts leading to instability and insecurity. As for the retention factors, they included affective attachment and sense of belonging to the professional environment and the country, followed by recognition and valorization at work. Several recommendations were developed to maintain quality of care delivery, including reforms of the health system, development of focused human resource retention strategies based on resource mapping evidence, negotiations with recruiting institutions to endorse the code ethics ending unethical practices draining countries' human resources, provision of financial incentives to doctors, and the recognition and valorization of physicians. Other rapid interventions were suggested, such as short-term medical missions to mitigate shortages in certain specialties, telemedicine, adaptation of recruitment processes to compensate for resources shortages in certain specialties, and adoption of task-shifting approaches to alleviate the workload on overburdened specialists.
Discussion
The findings of this study shed the light on the different factors influencing migration while framing them in the Lebanese context. These findings and recommendations should inform stakeholders and policy makers about the interventions needed to restore the quality of care. The feasibility and sustainability of most formulated recommendations depend on several factors, with political and socio-economic security and stability being the most crucial ones.
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