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Purpose: Arterial spin labeling (ASL) is a widely used contrast-free MRI method for assessing cerebral blood flow (CBF). Despite the generally adopted ASL acquisition guidelines, there is still wide variability in ASL analysis. We explored this variability through the ISMRM-OSIPI ASL-MRI Challenge, aiming to establish best practices for more reproducible ASL analysis. Methods: Eight teams analyzed the challenge data, which included a high-resolution T1-weighted anatomical image and 10 pseudo-continuous ASL datasets simulated using a digital reference object to generate ground-truth CBF values in normal and pathological states. We compared the accuracy of CBF quantification from each team's analysis to the ground truth across all voxels and within predefined brain regions. Reproducibility of CBF across analysis pipelines was assessed using the intra-class correlation coefficient (ICC), limits of agreement (LOA), and replicability of generating similar CBF estimates from different processing approaches. Results: Absolute errors in CBF estimates compared to ground-truth synthetic data ranged from 18.36 to 48.12 mL/100 g/min. Realistic motion incorporated into three datasets produced the largest absolute error and variability between teams, with the least agreement (ICC and LOA) with ground-truth results. Fifty percent of the submissions were replicated, and one produced three times larger CBF errors (46.59 mL/100 g/min) compared to submitted results. Conclusions: Variability in CBF measurements, influenced by differences in image processing, especially to compensate for motion, highlights the significance of standardizing ASL analysis workflows. We provide a recommendation for ASL processing based on top-performing approaches as a step toward ASL standardization.

Purpose: Arterial Spin Labeling (ASL) is widely used in clinical research as a contrast-free MRI method for assessment of cerebral blood flow (CBF). While the recommended guideline for ASL acquisition is generally adopted to standardize quantification of CBF, ASL analysis still produces wide variability in CBF estimates, limiting research and clinical interpretation of ASL results. This study explored the extent of variability in ASL CBF quantification through the ISMRM OSIPI ASL MRI Challenge. The goal of the challenge was to minimize sources of variability in ASL analysis by establishing best practice in ASL data processing to make ASL analysis more reproducible and clinically meaningful. Methods: Eight international teams analyzed the challenge data consisting of a high-resolution T1- weighted anatomical image and ten pseudo-continuous ASL (PCASL) datasets. The datasets were simulated using an ASL digital reference object to produce ground-truth CBF values in normal and pathological states. The accuracy of CBF quantification from each team’s analysis was compared to ground-truth values across all voxels and within pre-defined brain regions. Reproducibility of CBF estimates across analysis pipelines was assessed using intra-class correlation coefficient (ICC), the limits of agreement (LOA) and the replicability of generating similar CBF estimates from the image processing approaches as documented. Results: The absolute errors in CBF estimates compared to the ground-truth synthetic data ranged from 18.36 to 48.12 ml/100g/min. Realistic motion incorporated in three of the ten synthetic data produced the largest absolute CBF error, largest variability between teams, and the least agreement (ICC and LOA) with ground truth results. Fifty percent (4/8) of the teams’ methods were replicated, and one method produced three times larger CBF errors (46.59 ml/100g/min) compared to submitted results. Conclusions: The apparent variability in CBF measurements, influenced by diff

Bakgrund. Äldre personer utgör för närvarande den största patientgruppen som besöker akutmottagningar världen över och har ofta med sig vårdare eller anhöriga. Den åldrande andelen av befolkningen ökar vilket leder till en större belastning på hälso- och sjukvården. Akutmottagningar erbjuder akutvårdstjänster till allmänheten men de är inte särskilt anpassade för de unika behov äldre har. Att vara medveten om de problem som äldre och medföljande anhöriga stöter på under besöket på akutmottagningen kan leda till bättre anpassad vård för denna växande del av befolkningen. Syfte. Syftet med den här litteraturöversikten är att undersöka äldre personers och anhörigas upplevelser av besök på akutmottagningar. Metod. Metoden för denna studie är en litteraturöversikt av 14 artiklar från Australien, Europa, Nordamerika och Sydamerika. De databaser som användes för att hitta artiklarna var CINAHL och PubMed. Resultat. Resultatet delades in i positiva och negativa teman. De sex negativa teman som framkom var: Brist på kommunikation; Brist på delaktighet; Långa väntetider; Brist på uppmärksamhet; Bristfällig fysisk miljö och bristfällig hantering av behov och symtom. Det positiva temat som framkom var att akutmottagningar var lättillgängliga och tillförlitliga vårdinrättningar. Slutsats. Äldre personer och anhöriga upplever deras besök på akutmottagningar som mestadels negativa och visar att det finns ett behov av bättre kommunikationspraxis, positiva personcentrerade interaktioner mellan vårdpersonal, patienter och anhöriga samt förändringar i den fysiska miljön och organisationen på akutmottagningar., Background. Older people currently constitute the largest patient group visiting emergency departments worldwide and are often accompanied by carers and/or relatives. The aging part of the population is increasing which leads to a greater strain on the health care system. While emergency departments offer acute care services to the general population, they are not well suited for the particular needs of older people and their relatives. Being aware of the issues older people and their relatives face during visits to the emergency department can help to deliver better suited care for this growing part of the population. Aim. The aim of this literature review is to investigate older peoples’ and relatives’ experiences of visiting emergency departments. Methods. The method of this study is a literature review of 14 articles from Australia, Europe, North America and South America. The databases used to find the articles were CINAHL and PubMed. Results. Results were divided into positive and negative themes. The six negative themes that emerged were: Lack of communication; Lack of patient involvement; Long waiting times; Lack of attentiveness; Inadequate physical environment and inadequate management of needs and symptoms. The positive theme that emerged was that emergency departments as reliable and easily accessible health care facilities. Conclusions. Older people and their relatives see their emergency department experience as mostly negative, exposing a need for better communication practices, positive person-centred interactions between health care staff and patients as well as their relatives and changes to the physical environment and health care system of the emergency department.