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Background: Social constructs like race can affect how patients are perceived and impact care. This study investigated whether mentions of race in notes for critically ill patients differed according to patients' race. Methods: This retrospective cohort study included intensive care unit notes for adults (≥18 years old) admitted to any of 6 intensive care units at University of California, San Francisco, from 2012 through 2020. Notes were linked to National Provider Identifier records to obtain note writer characteristics. Logistic regression analysis with robust SEs clustered on note writers was adjusted for patient-, note- and clinician-level characteristics. Any race or ethnicity mention was the outcome of interest. Results: Among 5573 patients with 292 457 notes by 9742 unique note writers, 3225 patients (57.9%) self-reported their race as White, 997 (17.9%) as Asian, 860 (15.4%) as Latinx, and 491 (8.8%) as Black. Note writers documented race/ethnicity for 20.8% of Black, 10.9% of Latinx, 9.1% of White, and 4.4% of Asian patients. Black patients were more likely than White patients to have race mentioned in notes (adjusted odds ratio, 2.05 [95% CI, 1.49-2.82]). Conclusions: Black patients were more than twice as likely as White patients to have race mentioned in notes. Note language containing information on social constructs has consequences for clinicians and patients reading notes and for algorithms trained on clinical notes. [ABSTRACT FROM AUTHOR]

ObjectivesTo report prevalence, correlates, and medication management of pain in community-dwelling older adults with dementia.DesignCross-sectional.SettingIn-person interviews with self- or proxy respondents living in private residences or non-nursing home residential care settings.ParticipantsNationally representative sample of community-dwelling Medicare beneficiaries aged 65 and older enrolled in the National Health and Aging Trends Study 2011 wave.MeasurementsDementia status was determined using a modified previously validated algorithm. Participants were asked whether they had had bothersome and activity-limiting pain over the past month. A multivariable Poisson regression model was used to determine the relationship between bothersome pain and sociodemographic and clinical characteristics.ResultsOf the 7,609 participants with complete data on cognitive function, 802 had dementia (67.2% aged ≥80, 65.0% female, 67.9% white, 49.7% proxy response, 32.0% lived alone, 18.8% lived in residential care); 670 (63.5%) participants with dementia experienced bothersome pain, and 347 (43.3%) had pain that limited activities. These rates were significantly higher than in a propensity score-matched cohort without dementia (54.5% bothersome pain, P < .001, 27.2% pain that limited activity, P < .001). Proxies reported slightly higher rates of pain than self-respondents, but differences were statistically significant only for activity-limiting pain (46.6% proxy vs 40.1% self, P = .03). Correlates of bothersome pain included arthritis, heart and lung disease, less than high school education, activity of daily living disability, depressive and anxiety symptoms, and low energy. Of those reporting pain, 30.3% stated that they rarely or never took any medications for pain.ConclusionCommunity-living older adults with dementia are at high risk of having pain. Creative interventions and programs are needed to manage pain adequately in this vulnerable population.

Background: The role of neuroinflammation in psychiatric disorders is not well‐elucidated. A noninvasive technique sensitive to low‐level neuroinflammation may improve understanding of the pathophysiology of these conditions. Purpose: To test the ability of quantitative magnetization transfer (QMT) MR at 3 T for detection of low‐level neuroinflammation induced by typhoid vaccine within a clinically reasonable scan time. Study Type: Randomized, crossover, placebo‐controlled. Subjects: Twenty healthy volunteers (10 males; median age 34 years). Field Strength/Sequence: Magnetization prepared rapid gradient‐echo and MT‐weighted 3D fast low‐angle shot sequences at 3 T. Assessment: Participants were randomized to either vaccine or placebo first with imaging, then after a washout period received the converse with a second set of imaging. MT imaging, scan time, and blood‐based inflammatory marker concentrations were assessed pre‐ and post‐vaccine and placebo. Mood was assessed hourly using the Profile of Mood States questionnaire. QMT parameter maps, including the exchange rate from bound to free pool (kba) were generated using a two‐pool model and then segmented into tissue type. Statistical Tests: Voxel‐wise permutation‐based analysis examined inflammatory‐related alterations of QMT parameters. The threshold‐free cluster enhancement method with family‐wise error was used to correct voxel‐wise results for multiple comparisons. Region of interest averages were fed into mixed models and Bonferroni corrected. Spearman correlations assessed the relationship between mood scores and QMT parameters. Results were considered significant if corrected P < 0.05. Results: Scan time for the MT‐weighted acquisition was approximately 11 minutes. Blood‐based analysis showed higher IL‐6 concentrations post‐vaccine compared to post‐placebo. Voxel‐wise analysis found three clusters indicating an inflammatory‐mediated increase in kba in cerebellar white matter. Cerebellar kba for white matter was negatively associated with vigor post‐vaccine but not post‐placebo. Data Conclusion: This study suggested that QMT at 3 T may show some sensitivity to low‐level neuroinflammation. Further studies are needed to assess the viability of QMT for use in inflammatory‐based disorders. Evidence Level: 1 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]

Map comparisons in three‐dimensional space (3D) and 3D time series (4D) are becoming a necessity with increased availability of multidimensional data and model simulation outputs. Therefore, this research study extends the two‐dimensional (2D) map comparison methods with the aim to propose a suite of 3D approaches such as 3D Kappa, 3D Fuzzy, and 4D Fuzzy Kappa coefficients specifically designed to perform with voxel data. These proposed approaches can account for fuzziness where small categorical differences in 3D space or space‐time are given a degree of similarity instead of a binary similarity value. The developed approaches are tested using different voxel data sets: (a) hypothetical with two and four classes to confirm the methods produce expected results, (b) voxelized LiDAR data to demonstrate the comparison of real 3D data sets, (c) soil horizon voxel data sets to conduct a sensitivity analysis of 3D voxel window sizes, (d) 4D outputs from an agent‐based forest‐fire smoke model to demonstrate the 4D Fuzzy Kappa coefficient and a sensitivity analysis of 4D voxel window size. The obtained results indicate that 3D and 4D voxel data comparisons are feasible allowing for further work on comparison of 3D data and evaluation of multidimensional models. [ABSTRACT FROM AUTHOR]

Purpose: Quantitative magnetization transfer (qMT) imaging can be used to quantify the proportion of protons in a voxel attached to macromolecules. Here, we show that the original qMT balanced steady‐state free precession (bSSFP) model is biased due to over‐simplistic assumptions made in its derivation. Theory and Methods: We present an improved model for qMT bSSFP, which incorporates finite radiofrequency (RF) pulse effects as well as simultaneous exchange and relaxation. Furthermore, a correction relating to finite RF pulse effects for sinc‐shaped excitations is derived. The new model is compared to the original one in numerical simulations of the Bloch‐McConnell equations and in previously acquired in vivo data. Results: Our numerical simulations show that the original signal equation is significantly biased in typical brain tissue structures (by 7%‐20%), whereas the new signal equation outperforms the original one with minimal bias (<1%). It is further shown that the bias of the original model strongly affects the acquired qMT parameters in human brain structures, with differences in the clinically relevant parameter of pool‐size‐ratio of up to 31%. Particularly high biases of the original signal equation are expected in an MS lesion within diseased brain tissue (due to a low T2/T1‐ratio), demanding a more accurate model for clinical applications. Conclusion: The improved model for qMT bSSFP is recommended for accurate qMT parameter mapping in healthy and diseased brain tissue structures. [ABSTRACT FROM AUTHOR]

Purpose The ability to evaluate pathological changes in the spinal cord in multiple sclerosis (MS) is limited because T1- and T2-w MRI imaging are not sensitive to biochemical changes in vivo. Amide proton transfer (APT) chemical exchange saturation transfer (CEST) can indirectly detect amide protons associated with proteins and peptides, potentially providing more pathological specificity. Here, we implement APT CEST in the cervical spinal cord of healthy and MS cohorts at 3T. Methods APT CEST of the cervical spinal cord was obtained in a cohort of 10 controls and 10 MS patients using a novel respiratory correction methodology. APT was quantified using two methods: 1) APTw, based off the conventional magnetization transfer ratio asymmetry, and 2) ΔAPT, a spatial characterization of APT changes in MS patients relative to the controls. Results Respiratory correction yielded highly reproducible z-spectra in white matter (intraclass correlation coefficient = 0.82). APTw signals in normal-appearing white matter (NAWM) of MS patients were significantly different from healthy controls ( P = 0.04), whereas ΔAPT of MS patients highlighted large APT differences in NAWM. Conclusion Respiration correction in the spinal cord is necessary to accurately quantify APT CEST, which can provide unique biochemical information regarding disease processes within the spinal cord. Magn Reson Med 79:806-814, 2018. © 2017 International Society for Magnetic Resonance in Medicine. [ABSTRACT FROM AUTHOR]

Purpose To develop a chemical exchange saturation transfer (CEST) scheme sensitive to hydroxyl protons at 3 T. Clinical imaging of hydroxyl moieties can have an impact on osteoarthritis, neuropsychiatric disorders, and cancer. Theory: By varying saturation amplitude linearly with frequency offset, the direct water saturation component of the Z-spectrum is flattened and can be subtracted to produce a magnetization transfer ratio difference spectrum (MTRdiff) that isolates solute resonances. Variable saturation power allows for near optimization of hydroxyl and amine/amide moieties in one Z-spectrum. Methods Phantom studies were used to test vCEST performance in two environments: (1) aqueous single-solute (glycogen, glucose); (2) aqueous multiple solute (glycogen with bovine serum albumin). In vivo vCEST imaging of glycosaminoglycan content in patellar-femoral cartilage was performed in a subject with history of cartilage transplant. Results In solutions with overlapping resonances, vCEST resolves separate hydroxyl and amine/amide peaks. CEST hydroxyl signal in cartilage is negligible, but with vCEST, hydroxyl signal ranged from 2 to 5% ppm and showed distinct contrast between lesions and normal appearing cartilage. Conclusion Introduced a variable saturation amplitude CEST (vCEST) scheme to improve sensitivity to exchangeable hydroxyl moieties at 3 T resulting in detection of hydroxyl in the presence of multiple solutes with overlapping resonances. Magn Reson Med 76:826-837, 2016. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The optic nerve (ON) is a vital structure in the human visual system and transports all visual information from the retina to the cortex for higher order processing. Due to the lack of redundancy in the visual pathway, measures of ON damage have been shown to correlate well with visual deficits. These measures are typically taken at an arbitrary anatomically defined point along the nerve and do not characterize changes along the length of the ON. We propose a fully automated, three-dimensionally consistent technique building upon a previous independent slice-wise technique to estimate the radius of the ON and surrounding cerebrospinal fluid (CSF) on high-resolution heavily T2-weighted isotropic MRI. We show that by constraining results to be three-dimensionally consistent this technique produces more anatomically viable results. We compare this technique with the previously published slice-wise technique using a short-term reproducibility data set, 10 subjects, follow-up <1 month, and show that the new method is more reproducible in the center of the ON. The center of the ON contains the most accurate imaging because it lacks confounders such as motion and frontal lobe interference. Long-term reproducibility, 5 subjects, follow-up of approximately 11 months, is also investigated with this new technique and shown to be similar to short-term reproducibility, indicating that the ON does not change substantially within 11 months. The increased accuracy of this new technique provides increased power when searching for anatomical changes in ON size amongst patient populations.

The optic nerve (ON) plays a crucial role in human vision transporting all visual information from the retina to the brain for higher order processing. There are many diseases that affect the ON structure such as optic neuritis, anterior ischemic optic neuropathy and multiple sclerosis. Because the ON is the sole pathway for visual information from the retina to areas of higher level processing, measures of ON damage have been shown to correlate well with visual deficits. Increased intracranial pressure has been shown to correlate with the size of the cerebrospinal fluid (CSF) surrounding the ON. These measures are generally taken at an arbitrary point along the nerve and do not account for changes along the length of the ON. We propose a high contrast and high-resolution 3-D acquired isotropic imaging sequence optimized for ON imaging. We have acquired scan-rescan data using the optimized sequence and a current standard of care protocol for 10 subjects. We show that this sequence has superior contrast-to-noise ratio to the current standard of care while achieving a factor of 11 higher resolution. We apply a previously published automatic pipeline to segment the ON and CSF sheath and measure the size of each individually. We show that these measures of ON size have lower short-term reproducibility than the population variance and the variability along the length of the nerve. We find that the proposed imaging protocol is (1) useful in detecting population differences and local changes and (2) a promising tool for investigating biomarkers related to structural changes of the ON.

There is a growing interest in identifying neuroimaging-based biomarkers for Parkinson's disease (PD), a progressive neurodegenerative disorder in which the major pathologic substrate is the loss of pigmented dopaminergic neurons in the substantia nigra (SN). Recently, an MRI technique dubbed "neuromelanin-sensitive MRI" (NM-MRI), has been found to provide notable contrast between the SN and surrounding brain tissues with potential applications as biomarker of PD. The contrast in NM-MRI has been associated with magnetization transfer (MT) effects, and thus the goal of this study was to characterize the impact of MT on NM-MRI, and to demonstrate the feasibility of performing quantitative MT (qMT) imaging in human SN. The results of this study demonstrate that high-resolution rapid qMT imaging of the SN can be reliably obtained within reasonable scan times, thereby can be translatable into clinical practice.