FDG PET Findings Post-COVID Vaccinations: Signs of the Times?

ABSTRACT: Vaccinations can cause hypermetabolic axillary lymphadenopathy on FDG PET. We present the case of a 71-year-old man who underwent FDG PET/CT for melanoma staging 6 days following a COVID (coronavirus disease) vaccination. Imaging showed a prominent intramuscular mass at the vaccination site, in addition to extensive axillary lymphadenopathy. The mass was compatible with a hematoma at the vaccination site, and the lymphadenopathy was most likely reactive. This case demonstrates unconventional findings in response to a routine vaccination event-findings that, in light of current world events, are likely to be routinely encountered on PET imaging and that should be recognized reactive rather malignant.

An Update in Imaging of Blunt Vascular Neck Injury.

Traumatic injuries of the cervical carotid and vertebral arteries, collectively referred to as blunt cerebrovascular injury (BCVI), can result in significant patient morbidity and mortality, with one of the most feared outcomes being cerebrovascular ischemia. Systematic imaging-guided screening for BCVI aims for early detection to guide timely management. In particular, accurate detection of the severity and grade of BCVI is paramount in guiding initial management. Furthermore, follow-up imaging is required to decide the duration of antithrombotic therapy. In this article, classification of the grades of BCVI and associated imaging findings will be outlined and diagnostic pitfalls and mimickers that can confound diagnosis will be described. In addition, updates to existing screening guidelines and recent efforts of criteria modification to improve detection of BCVI cases will be reviewed. The advent of postprocessing tools applied to conventional computed tomography (CT) angiograms and new diagnostic tools in dual energy CT for improved detection will also be discussed.

Gender Differences in Leadership Positions Among Academic Nuclear Medicine Specialists in Canada and the United States.

OBJECTIVE: Despite equal representation of genders among medical students, women continue to be underrepresented in the field of academic diagnostic radiology. These differences are manifest across subspecialties in academic medicine and even in diagnostic radiology. There are limited data available addressing diversity among nuclear medicine specialists. Thus, our primary objective was to compare gender representation in academic and leadership positions among faculty members in nuclear medicine in Canada and the United States. Our secondary objective was to study the influences to account for the existing disparity in academic nuclear medicine. MATERIALS AND METHODS: Using the Fellowship and Residency Electronic Interactive Database (FREIDA) and Canadian Resident Matching Service (CaRMS), we created a database of faculty members in nuclear medicine. For assessment of academic performance, the h-index, number of publications, number of citations, and years of active research were extracted using Scopus. RESULTS: The academic ranks of 237 faculty members were used for analysis; of this group, 16.95% of associate professors were female. Women were less frequently represented in higher academic ranks, and women were also less frequently represented in leadership ranks (13.6% female vs 86.4% male). The h-index was comparable across genders. CONCLUSION: Female nuclear medicine specialists are underrepresented in academic and leadership positions compared with their male counterparts. This difference in numbers is unlikely to be because of academic performance given that both genders had comparable academic performance metrics in our study. The results show the need for devising strategies to promote diversity in academic and leadership positions across nuclear medicine specialists.

Variability in prefrontal hemodynamic response during exposure to repeated self-selected music excerpts, a near-infrared spectroscopy study.

Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes. Clinical applications of music may involve prolonged or repeated exposures to music. However, the variability of the observed brain activity patterns in repeated exposures to music is not well understood. We hypothesized that multiple exposures to the same music would elicit more consistent activity patterns than exposure to different music. In this study, the temporal and spatial variability of cerebral prefrontal hemodynamic response was investigated across multiple exposures to self-selected musical excerpts in 10 healthy adults. The hemodynamic changes were measured using prefrontal cortex near infrared spectroscopy and represented by instantaneous phase values. Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains. The consistency index across repeated exposures to the same piece of music was compared to the consistency index corresponding to prefrontal activity from randomly matched non-identical musical excerpts. Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions. When all four exposures were compared, no significant difference was observed between the consistency indexes of randomly matched non-identical musical excerpts and the consistency index corresponding to repetitions of the same musical excerpts. This observation suggests the existence of only partial consistency between repeated exposures to the same musical excerpt, which may stem from the role of the prefrontal cortex in regulating other cognitive and emotional processes.

A review of EEG-based brain-computer interfaces as access pathways for individuals with severe disabilities.

Electroencephalography (EEG) is a non-invasive method for measuring brain activity and is a strong candidate for brain-computer interface (BCI) development. While BCIs can be used as a means of communication for individuals with severe disabilities, the majority of existing studies have reported BCI evaluations by able-bodied individuals. Considering the many differences in body functions and usage scenarios between individuals with disabilities and able-bodied individuals, involvement of the target population in BCI evaluation is necessary. In this review, 39 studies reporting EEG-oriented BCI assessment by individuals with disabilities were identified in the past decade. With respect to participant populations, a need for assessing BCI performance for the pediatric population with severe disabilities was identified as an important future direction. Acquiring a reliable communication pathway during early stages of development is crucial in avoiding learned helplessness in pediatric-onset disabilities. With respect to evaluation, augmenting traditional measures of system performance with those relating to contextual factors was recommended for realizing user-centered designs appropriate for integration in real-life. Considering indicators of user state and developing more effective training paradigms are recommended for future studies of BCI involving individuals with disabilities.

Knowledge translation in rehabilitation engineering research and development: a knowledge ecosystem framework.

Rehabilitation engineering is concerned with technology innovations and technology-mediated treatments for the improvement of quality of care and quality of life of individuals with disability. Unlike many other fields of health research, the knowledge translation (KT) cycle of rehabilitation engineering research and development (R&D) is often considered incomplete until a technology product or technology-facilitated therapy is available to target clientele. As such, the KT journey of rehabilitation engineering R&D is extremely challenging, necessarily involving knowledge exchange among numerous players across multiple sectors. In this article, we draw on recent literature about the knowledge trichotomy in technology-based rehabilitation R&D and propose a knowledge ecosystem to frame the rehabilitation engineering KT process from need to product. Identifying the principal process of the ecosystem as one of knowledge flow, we elucidate the roles of repository and networked knowledge, identify key consumers and producers in a trinity of communities of practice, and draw on knowledge management literature to describe different knowledge flows. The article concludes with instantiations of this knowledge ecosystem for 2 local rehabilitation engineering research-development-commercialization endeavors.

Characterizing emotional response to music in the prefrontal cortex using near infrared spectroscopy.

Known to be involved in emotional processing the human prefrontal cortex (PFC), can be non-invasively monitored using near-infrared spectroscopy (NIRS). As such, PFC NIRS can serve as a means for studying emotional processing by the PFC. Identifying patterns associated with emotions in PFC using NIRS may provide a means of bedside emotion identification for nonverbal children and youth with severe physical disabilities. In this study, NIRS was used to characterize the PFC hemodynamic response to emotional arousal and valence in a music-based emotion induction paradigm in 9 individuals without disabilities or known health conditions. In particular, a novel technique based on wavelet-based peak detection was used to characterize chromophore concentration patterns. The maximum wavelet coefficients extracted from oxygenated hemoglobin concentration waveforms from all nine recording locations on the PFC were significantly associated with emotional valence and arousal. Specifically, high arousal and negative emotions were associated with larger maximum wavelet coefficients.

Automatic detection of a prefrontal cortical response to emotionally rated music using multi-channel near-infrared spectroscopy.

Emotional responses can be induced by external sensory stimuli. For severely disabled nonverbal individuals who have no means of communication, the decoding of emotion may offer insight into an individual's state of mind and his/her response to events taking place in the surrounding environment. Near-infrared spectroscopy (NIRS) provides an opportunity for bed-side monitoring of emotions via measurement of hemodynamic activity in the prefrontal cortex, a brain region known to be involved in emotion processing. In this paper, prefrontal cortex activity of ten able-bodied participants was monitored using NIRS as they listened to 78 music excerpts with different emotional content and a control acoustic stimuli consisting of the Brown noise. The participants rated their emotional state after listening to each excerpt along the dimensions of valence (positive versus negative) and arousal (intense versus neutral). These ratings were used to label the NIRS trial data. Using a linear discriminant analysis-based classifier and a two-dimensional time-domain feature set, trials with positive and negative emotions were discriminated with an average accuracy of 71.94% ± 8.19%. Trials with audible Brown noise representing a neutral response were differentiated from high arousal trials with an average accuracy of 71.93% ± 9.09% using a two-dimensional feature set. In nine out of the ten participants, response to the neutral Brown noise was differentiated from high arousal trials with accuracies exceeding chance level, and positive versus negative emotional differentiation accuracies exceeded the chance level in seven out of the ten participants. These results illustrate that NIRS recordings of the prefrontal cortex during presentation of music with emotional content can be automatically decoded in terms of both valence and arousal encouraging future investigation of NIRS-based emotion detection in individuals with severe disabilities.