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Competing Interests: The authors report no conflicts of interest.

Background: Abdominopelvic magnetic resonance imaging (MRI) is increasingly being used to evaluate children with abdominal pain suspected of having acute appendicitis. At our institution, these examinations are preliminarily interpreted by radiology residents, especially when performed after hours., Objective: To determine the accuracy of preliminary reports rendered by radiology residents in this setting., Materials and Methods: Three hundred seventy-seven pediatric abdominopelvic MRI examinations were included. The preliminary (resident) and final (attending) radiology reports were coded as diagnosing acute appendicitis or no acute appendicitis. The concordance between resident and attending radiologist interpretations was calculated. Additionally, both resident and attending reports were compared to available surgical pathology or clinical follow-up data., Results: Overall concordance rate for the diagnosis of acute appendicitis was 97.1%. Concordance for verified cases of acute appendicitis was 93.4%. Concordance rates did not differ by residents' postgraduate year levels. When compared against surgical pathology or clinical follow-up data, residents demonstrated 91.2% sensitivity and 97.6% specificity. There was no statistically significant difference in the sensitivity or specificity of resident or attending radiologist interpretations., Conclusion: Radiology residents demonstrate high concordance with attending pediatric radiologists in their interpretations of pediatric abdominopelvic MRI for acute appendicitis. The diagnostic performances of residents and attendings were comparable.

Prophylactic cranial irradiation (PCI) is used to decrease the probability of developing brain metastases in patients with small cell lung cancer and has been linked to deleterious cognitive effects. Although no well-established imaging markers for these effects exist, previous studies have shown that structural and metabolic changes in the brain can be detected with MRI and PET. This study used an image processing technique called texture analysis to explore whether global changes in brain glucose metabolism could be characterized in PET images. Methods: 18 F-FDG PET images of the brain from patients with small cell lung cancer, obtained before and after the administration of PCI, were processed using texture analysis. Texture features were compared between the pre- and post-PCI images. Results: Multiple texture features demonstrated statistically significant differences before and after PCI when texture analysis was applied to the brain parenchyma as a whole. Regional differences were also seen but were not statistically significant. Conclusion: Global changes in brain glucose metabolism occur after PCI and are detectable using advanced image processing techniques. These changes may reflect radiation-induced damage and thus may provide a novel method for studying radiation-induced cognitive impairment., (© 2021 by the Society of Nuclear Medicine and Molecular Imaging.)

Oxidative stress and chronic inflammation in arterial walls have been implicated in intracranial aneurysm (IA) formation and rupture. Dimethyl fumarate (DMF) exhibits immunomodulatory properties, partly via activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway which reduces oxidative stress by inducing the antioxidant response element (ARE). This study evaluated the effects of DMF both in vitro, using tumor necrosis factor (TNF)-α-treated vascular smooth muscle cells (VSMC), and in vivo, using a murine elastase model to induce aneurysm formation. The mice were treated with either DMF at 100 mg/kg/day P.O. or vehicle for two weeks. DMF treatment protected VSMCs from TNF-α-induced inflammation as demonstrated by its downregulation of cytokines and upregulation of Nrf2 and smooth muscle cell markers. At higher doses, DMF also inhibited the pro-proliferative action of TNF-α by increasing apoptosis which protected the cells from aponecrosis. In mice, DMF treatment significantly decreased the incidence of aneurysm formation and rupture, at the same time increasing Nrf2 levels. DMF demonstrated a neuroprotective effect in mice with a resultant inhibition of oxidative stress, inflammation, and fibrosis in the cerebrovasculature. This suggests a potential role for DMF as a rescue therapy for patients at risk for formation and rupture of IAs.

Ovarian cancer has the lowest survival rate among all gynecologic cancers predominantly due to late diagnosis. Early detection of ovarian cancer can increase 5-year survival rates from 40% up to 92%, yet no reliable early detection techniques exist. Optical coherence tomography (OCT) is an emerging technique that provides depth-resolved, high-resolution images of biological tissue in real-time and demonstrates great potential for imaging of ovarian tissue. Mouse models are crucial to quantitatively assess the diagnostic potential of OCT for ovarian cancer imaging; however, due to small organ size, the ovaries must first be separated from the image background using the process of segmentation. Manual segmentation is time-intensive, as OCT yields three-dimensional data. Furthermore, speckle noise complicates OCT images, frustrating many processing techniques. While much work has investigated noise-reduction and automated segmentation for retinal OCT imaging, little has considered the application to the ovaries, which exhibit higher variance and inhomogeneity than the retina. To address these challenges, we evaluate a set of algorithms to segment OCT images of mouse ovaries. We examine five preprocessing techniques and seven segmentation algorithms. While all preprocessing methods improve segmentation, Gaussian filtering is most effective, showing an improvement of 32 % ± 1.2 % . Of the segmentation algorithms, active contours performs best, segmenting with an accuracy of 94.8 % ± 1.2 % compared with manual segmentation. Even so, further optimization could lead to maximizing the performance for segmenting OCT images of the ovaries.

Dementia is an important cause of morbidity and mortality worldwide and encompasses a very heterogenous group of disease processes. Positron emission tomography (PET) of the brain using fluorodeoxyglucose (FDG) is a useful modality for differentiating types of dementia. Because FDG does not bind to pathologic proteins, FDG-PET requires that the reader recognize characteristic patterns of glucose hypometabolism to identify pathology. These patterns have been documented in the literature for both primary neurodegenerative disorders and secondary causes of dementia. This article presents an algorithm for organizing these findings and systematically applying them to interpret FDG-PET brain imaging for dementia.

PET using FDG is a critical tool for evaluation of dementias, with characteristic patterns of hypometabolism suggesting specific diagnoses. Hypometabolism in the occipital region is recognized as an important finding associated with dementia with Lewy bodies and posterior cortical atrophy. We describe here the novel "occipital tunnel" sign, which results from relative sparing of FDG uptake in the medial occipital (primary visual) cortex compared with more severe loss in the surrounding lateral occipital (visual association) cortex. This sign is useful for recognizing the occipital findings of dementia with Lewy bodies and posterior cortical atrophy, especially when viewing sagittal projections.

Each year over one million patients with acute heart failure (AHF) present to a United States emergency department (ED). The vast majority are hospitalized for further management. The length of stay and high postdischarge event rate in this cohort have changed little over the past decade. Therapeutic trials have failed to yield substantive improvement in postdischarge outcomes; subsequently, AHF care has changed little in the past 40 years. Prior research studies have been fragmented as either "inpatient" or "ED-based." Recognizing the challenges in identification and enrollment of ED patients with AHF, and the lack of robust evidence to guide management, an AHF clinical trials network was developed. This network has demonstrated, through organized collaboration between cardiology and emergency medicine, that many of the hurdles in AHF research can be overcome. The development of a network that supports the collaboration of acute care and HF researchers, combined with the availability of federally funded infrastructure, will facilitate more efficient conduct of both explanatory and pragmatic trials in AHF. Yet many important questions remain, and in this document our group of emergency medicine and cardiology investigators have identified four high-priority research areas., (© 2017 by the Society for Academic Emergency Medicine.)

Background: Intracranial aneurysms (IA) are increasingly recognized as a disease driven by chronic inflammation. Recent research has identified key mediators and processes underlying IA pathogenesis, but mechanistic understanding remains incomplete. Lymphocytic infiltrates have been demonstrated in patient IA tissue specimens and have also been shown to play an important role in abdominal aortic aneurysms (AAA) and related diseases such as atherosclerosis. However, no study has systematically examined the contribution of lymphocytes in a model of IA., Methods: Lymphocyte-deficient (Rag1) and wild-type (WT; C57BL/6 strain) mice were subjected to a robust IA induction protocol. Rates of IA formation and rupture were measured, and cerebral artery tissue was collected and utilized for histology and gene expression analysis., Results: At 2 weeks, the Rag1 group had significantly fewer IA formations and ruptures than the WT group. Histological analysis of unruptured IA tissue showed robust B and T lymphocyte infiltration in the WT group, while there were no differences in macrophage infiltration, IA diameter, and wall thickness. Significant differences in interleukin-6 (IL-6), matrix metalloproteinases 2 (MMP2) and 9 (MMP9), and smooth muscle myosin heavy chain (MHC) were observed between the groups., Conclusions: Lymphocytes are key contributors to IA pathogenesis and provide a novel target for the prevention of IA progression and rupture in patients.

Case: We describe the clinical and histopathological findings associated with a case of pyoderma gangrenosum (PG) after revision total hip arthroplasty. The patient developed an expanding purple-red, necrotic, ulcerative lesion at the surgical site, which was initially suspected to be either a surgical-site infection or warfarin-induced skin necrosis. After treatment with empiric intravenous antibiotics, surgical debridement, and vacuum-assisted closure of the wound, the patient had a painless hip with a remodeled scar and was asymptomatic at the seven-year follow-up., Conclusion: Confirmation of the diagnosis of surgical-site PG requires clinical-pathological correlation and familiarity with the PG skin lesion. Treatment of PG differs from treatment of infection; therefore, misdiagnosis and surgical treatment may exacerbate the clinical findings in PG.

Inflammatory processes are implicated in many diseases of the vasculature and have been shown to play a key role in the formation of intracranial aneurysms (IAs). Although the specific mechanisms underlying these processes have been thoroughly investigated in related pathologies, such as atherosclerosis, there remains a paucity of information regarding the immunopathology of IA. Cells such as macrophages and lymphocytes and their effector molecules have been suggested to be players in IA, but their specific interactions and the role of other components of the inflammatory response have yet to be determined. Drawing parallels between the pathogenesis of IA and other vascular disorders could provide a roadmap for developing a mechanistic understanding of the immunopathology of IA and uncovering useful targets for therapeutic intervention. Future research should address the presence and function of leukocyte subsets, mechanisms of leukocyte recruitment and activation, and the role of damage-associated molecular patterns in IA.

Cutaneous Merkel cell carcinoma (MCC) typically involves the dermis. Less than 10% of MCC have epidermal involvement. Only one MCC confined exclusively to the epidermis has been previously reported but was not recognized until the lesion recurred with typical MCC in the dermis. We present a case of a wholly intraepidermal pagetoid MCC without dermal involvement in a 74-year-old man with a 2.0-cm solitary verrucous papule on the left index finger. The initial biopsy and complete excision specimens showed marked epidermal hyperplasia, focal prominent squamous cell atypia, and MCC with florid pagetoid spread through the epidermis. There was no evidence of tumor within the dermis. The pagetoid MCC tumor cells showed diffuse cytoplasmic staining with antibodies to cytokeratin 20, and negative staining for chromogranin, neurofilament, S-100, vimentin, HMB45, leukocyte common antigen, and CD3. The cell of origin of MCC is still debated. The existence of an entirely intraepidermal variant of MCC would lend support to the view that MCC is a neoplastic expression of Merkel cells in at least some cases. Dermal-based MCC is a high-grade primary cutaneous neoplasm, but MCC confined exclusively to the epidermis may have a better prognosis.

The CMA's Committee on Ethics will present a revised Code of Ethics for consideration by General Council during the annual meeting in Sydney, NS, later this month. This article outlines the reasons for updating the current (1990) version of the code and explains some of the significant changes and omissions. If approved by General Council, the revised code will take effect immediately.

As health care systems undergo funding cutbacks, we cannot expect to receive all needed and wanted health care services at public expense. Instead, choices must be made about which services will be provided from public funds (and to whom), which will be available to individuals who wish to purchase them, and which will not be available at all. These are ethical questions, if only because the proposed answers will reflect different concepts of social justice. This article identifies and describes some of the major ethical considerations in redefining the principle of "comprehensiveness" in the Canada Health Act. The authors argue that the criterion of "medical necessity" may no longer be, if indeed it ever was, adequate for determining which health services should be publicly funded. They do not believe that any single criterion can fulfill this role. Instead, they propose that policy makers focus on developing a better process for making choices among health care priorities. Clearly defined roles in this process must be established for payers, the public and providers.

The CMA's Working Group on Core and Comprehensive Health Care Services recognizes ethics to be one of the three key factors in determining which services should be publicly funded. The role of ethics is to identify and make explicit the principles and values, at individual and societal levels, that lie behind judgements and positions. Two types of ethical issues are addressed: one deals with the criteria for these services and the other with the process to be followed. The five ethical criteria discussed are fairness, age, lifestyle, the identifiable versus the statistical patient, and futility. An ethical process incorporates appropriate roles for the public physicians and payers (government) and accountability of all participants. A provided checklist for determining a fair process asks such questions as Do potential users of a service, its providers and the public have an adequate say in the decision about whether the service should be publicly funded? Are the reasons for the decision communicated to those affected by it? and is the service being denied to potential users on the basis of unfair discrimination or lifestyle?

This study examines the utility of objective histopathological studies in the evaluation of adult patients with erythroderma. A series of 56 skin biopsies, from 40 erythrodermic patients, was reviewed sequentially by 4 Canadian dermatopathologists who were unaware of clinical details of the cases. The final diagnosis (gold standard), in each instance, had already been determined by others, based on clinicopathologic data and response to therapy. Direct comparison revealed that the mean accuracy of the histopathological diagnoses was 53% (range: 48-66%), a favorable result in view of the difficulty of the task at hand. Additional points of information which evolved from the study are as follows: (i) identification, by microscopy alone, of spongiotic dermatitis, cutaneous T-cell lymphoma and psoriasis, as underlying causes of erythroderma was more successful than that of drug eruptions and pityriasis rubra pilaris; (ii) the epidermotropism which characterizes cutaneous T-cell lymphoma may be mistaken for inflammatory interface changes seen in drug eruptions and vice versa, thus constituting a pitfall in diagnosis; (iii) finally, it appears that submission of multiple simultaneous biopsies, rather than a single specimen, from patients with erythroderma would be likely to enhance the accuracy of histopathological diagnosis.