Publications by authors named "Schaefer P"

Article Synopsis
  • Portable low-field magnetic resonance imaging (LF-MRI) offers a promising way to assess Alzheimer's disease (AD) patients in places where traditional MRI isn't available, despite some limitations in image quality.
  • * Researchers optimized LF-MRI techniques and created a free machine learning tool for analyzing brain structure and white matter changes in patients with cognitive impairments.
  • * The study found that LF-MRI accurately measures hippocampal volumes and white matter hyperintensities, suggesting that this technology can improve access to neuroimaging for dementia patients at a lower cost.
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  • Cognitive motor dissociation (CMD) involves patients who can follow commands in brain scans like fMRI, despite showing no behavioral signs of language function, highlighting the importance of accurate diagnosis in severe brain injuries.
  • Recent findings outline a structured approach for assessing CMD at clinical institutions, underlining the need for ethical considerations, standardized protocols, and effective communication of results.
  • The proposed method for CMD assessment aims to be adaptable, allowing for updates and improvements as more evidence becomes available in the field.
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Background: Colorectal carcinoma (CRC) is one of the most frequently diagnosed forms of cancer worldwide. The (, ) and genes encode proteins that are important therapeutic targets for the treatment of CRC and, together with the mismatch repair (MMR) system, are closely related to patient prognosis and survival in advanced CRC. Here we evaluate the mutational profile and the frequency of mutations in the , and genes, along with the expression of MMR in advanced CRC, at a tertiary hospital in southern Brazil.

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In this episode of the Podcast Series on Training and Education, Pamela Schaefer, MD, joins host Monica Cheng, MD, to discuss incorporating education into radiology careers. Dr. Schaefer shares her journey, the role of leadership, and advice for aspiring educators.

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Urticaria and angioedema are caused by immunoglobulin E- and non-immunoglobulin E-mediated release of histamine and other inflammatory mediators from mast cells and basophils. Diagnosis is made clinically, and anaphylaxis must be ruled out if urticaria or angioedema is present. A limited nonspecific laboratory workup should be considered unless elements of the history or physical examination suggest specific underlying conditions.

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Objective: For stroke patients with unknown time of onset, mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) can guide thrombolytic intervention. However, access to MRI for hyperacute stroke is limited. Here, we sought to evaluate whether a portable, low-field (LF)-MRI scanner can identify DWI-FLAIR mismatch in acute ischemic stroke.

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Acute stroke imaging plays a vital and time-sensitive role in therapeutic decision-making. Current clinical workflows widely use computed tomography (CT) and magnetic resonance (MR) techniques including CT and MR perfusion to estimate the volume of ischemic penumbra at risk for infarction without acute intervention. The use of imaging techniques aimed toward evaluating the metabolic derangements underlying a developing infarct may provide additional information for differentiating the penumbra from benign oligemia and infarct core.

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NADH autofluorescence imaging is a promising approach for visualizing energy metabolism at the single-cell level. However, it is sensitive to the redox ratio and the total NAD(H) amount, which can change independently from each other, for example with aging. Here, we evaluate the potential of fluorescence lifetime imaging microscopy (FLIM) of NADH to differentiate between these modalities.

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Adaptive immunity requires the expansion of high-affinity lymphocytes from a heterogeneous pool. Whereas current models explain this through signal transduction, we hypothesized that antigen affinity tunes discrete metabolic pathways to license clonal lymphocyte dynamics. Here, we identify nicotinamide adenine dinucleotide (NAD) biosynthesis as a biochemical hub for the T cell receptor affinity-dependent metabolome.

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Background And Purpose: The use of MR imaging in emergency settings has been limited by availability, long scan times, and sensitivity to motion. This study assessed the diagnostic performance of an ultrafast brain MR imaging protocol for evaluation of acute intracranial pathology in the emergency department and inpatient settings.

Materials And Methods: Sixty-six adult patients who underwent brain MR imaging in the emergency department and inpatient settings were included in the study.

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Article Synopsis
  • Deep learning (DL) techniques have been tested for speeding up lumbar MRI exams, but their overall impact on scan time and image quality for routine use is still unclear.
  • A study evaluated 36 patients using both DL-accelerated and conventional MRI protocols, focusing on various diagnostic factors like stenosis and nerve compression.
  • Results showed that the DL method did not significantly differ in diagnostic quality but had lower signal-to-noise ratio and more artifacts, suggesting it can reduce scan times while providing comparable results.
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Early prediction of the recovery of consciousness in comatose cardiac arrest patients remains challenging. We prospectively studied task-relevant fMRI responses in 19 comatose cardiac arrest patients and five healthy controls to assess the fMRI's utility for neuroprognostication. Tasks involved instrumental music listening, forward and backward language listening, and motor imagery.

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The advent of portable, low-field MRI (LF-MRI) heralds new opportunities in neuroimaging. Low power requirements and transportability have enabled scanning outside the controlled environment of a conventional MRI suite, enhancing access to neuroimaging for indications that are not well suited to existing technologies. Maximizing the information extracted from the reduced signal-to-noise ratio of LF-MRI is crucial to developing clinically useful diagnostic images.

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Flow-related artifacts have been observed in highly accelerated T1-weighted contrast-enhanced wave-controlled aliasing in parallel imaging (CAIPI) magnetization-prepared rapid gradient-echo (MPRAGE) imaging and can lead to diagnostic uncertainty. We developed an optimized flow-mitigated Wave-CAIPI MPRAGE acquisition protocol to reduce these artifacts through testing in a custom-built flow phantom. In the phantom experiment, maximal flow artifact reduction was achieved with the combination of flow compensation gradients and radial reordered k-space acquisition and was included in the optimized sequence.

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Objectives: This systematic review aimed to evaluate the efficacy of supportive care provision, frequency and protocol in patients treated for peri-implantitis, as reported in prospective and retrospective studies of at least 3-years duration.

Materials And Methods: A systematic search of three electronic databases was undertaken up to 21 July 2022 and supplemented by hand-search to identify studies that included participants treated for peri-implantitis and followed for at least 3 years. Owing to high heterogeneity, a meta-analysis was not appropriate, and therefore, data and risk of bias were explored qualitatively.

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Urticaria and angioedema are caused by immunoglobulin E- and non-immunoglobulin E-mediated release of histamine and other inflammatory mediators from mast cells and basophils. Diagnosis is made clinically, and anaphylaxis must be ruled out if urticaria or angioedema is present. A limited nonspecific laboratory workup should be considered unless elements of the history or physical examination suggest specific underlying conditions.

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Ischemic strokes in young adults are increasing in incidence and have emerged as a public health issue. The radiological features are not only diagnostic in identifying ischemic infarctions but also provide important clues in the investigation of the underlying causes or in the identification of risk factors. According to the different imaging patterns associated with ischemic stroke in young adults, the causes can be classified into 5 categories: cardioembolism, large vessel vasculopathy, small vessel vasculopathy, toxic-metabolic, and hypercoagulable disorders.

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Machine learning (ML) algorithms to detect critical findings on head CTs may expedite patient management. Most ML algorithms for diagnostic imaging analysis utilize dichotomous classifications to determine whether a specific abnormality is present. However, imaging findings may be indeterminate, and algorithmic inferences may have substantial uncertainty.

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Background: Compared to healthy controls, severe COVID19 patients display increased levels of activated NLRP3-inflammasome (NLRP3-I) and interleukin (IL)-1β. SARS-CoV-2 encodes viroporin proteins E and Orf3a(2-E+2-3a) with homologs to SARS-CoV-1, 1-E+1-3a, which elevate NLRP3-I activation; by an unknown mechanism. Thus, we investigated how 2-E+2-3a activates the NLRP3-I to better understand the pathophysiology of severe COVID-19.

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Background And Purpose: A scout accelerated motion estimation and reduction (SAMER) framework has been developed for efficient retrospective motion correction. The goal of this study was to perform an initial evaluation of SAMER in a series of clinical brain MR imaging examinations.

Materials And Methods: Ninety-seven patients who underwent MR imaging in the inpatient and emergency department settings were included in the study.

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Article Synopsis
  • The study evaluated a new high-speed imaging technique called Wave-T1-MPRAGE, which aims to improve brain MRI scans by reducing the time needed for imaging while maintaining diagnostic quality.
  • Researchers compared this technique to the standard T1-MPRAGE sequence in 80 patients, focusing on how well each method visualizes enhancing lesions and the impact of motion artifacts and noise.
  • The results showed that Wave-T1-MPRAGE performed equally well in detecting brain lesions and had significant advantages, including halving the scan time while minimizing noise and motion issues.
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