Publications by authors named "John Magnussen"

Disorders affecting the neurological and musculoskeletal systems represent international health priorities. A significant impediment to progress in trials of new therapies is the absence of responsive, objective, and valid outcome measures sensitive to early disease changes. A key finding in individuals with neuromuscular and musculoskeletal disorders is the compositional changes to muscles, evinced by the expression of fatty infiltrates.

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Computational neurosurgery is a novel and disruptive field where artificial intelligence and computational modeling are used to improve the diagnosis, treatment, and prognosis of patients affected by diseases of neurosurgical relevance. The field aims to bring new knowledge to clinical neurosciences and inform on the profound questions related to the human brain by applying augmented intelligence, where the power of artificial intelligence and computational inference can enhance human expertise. This transformative field requires the articulation of ethical considerations that will enable scientists, engineers, and clinical neuroscientists, including neurosurgeons, to ensure that the use of such a powerful application is conducted based on the highest moral and ethical standards with a patient-centric approach to predict and prevent mistakes.

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Background: Limited studies of multiple sclerosis (MS) exist whereby magnetic resonance imaging (MRI) of the brain with consistent imaging protocols occurs at the same time points as collection of healthy lifestyle measures. The aim of this study was to test the feasibility, acceptability and preliminary efficacy of acquiring MRI data as an objective, diagnostic and prognostic marker of MS, at the same time point as brain-healthy lifestyle measures including diet.

Methods: Participants living with relapsing remitting MS partook in one structural MRI scanning session of the brain, completed two online 24-hour dietary recalls and demographic and self-reported lifestyle questionnaires (e.

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Background: Lumbar disc degeneration (DD) is widely regarded as a likely contributor to low back pain (LBP), but the association between DD and LBP is relatively weak. No known studies have normalized quantitative measures of DD severity relative to multiple variables such as age, height, and disc level. This study developed normalized quantitative measures (z-scores) of disc signal intensity (DSI) and disc height (DH) to rate relative severity of DD.

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Article Synopsis
  • Chiari I malformation is characterized by the cerebellar tonsils descending more than 5 mm below the foramen magnum, and suboccipital decompression is the primary treatment for patients experiencing symptoms.
  • Some conditions can appear similar to Chiari I malformation on imaging, which can lead to misdiagnosis and inappropriate treatments, including unnecessary surgeries.
  • The study aims to analyze these mimicking conditions, such as post-traumatic arachnoiditis and spontaneous intracranial hypotension, to identify their distinct imaging features and improve diagnosis and management strategies, reducing the risk of mismanagement.*
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Background: The accuracy of diagnostic tests available in primary care to identify the disc, sacroiliac joint, and facet joint as the source of low back pain is uncertain.

Methods: Systematic review of diagnostic tests available in primary care. MEDLINE, CINAHL, and EMBASE were searched between March 2006 and 25th January 2023.

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Questions: Do magnetic resonance imaging (MRI) findings predict future low back pain (LBP), associated disability and global recovery in people with current LBP? Do MRI findings predict these outcomes in people with no current LBP? Do MRI findings predict these outcomes in a mixed sample of people with and without current LBP?

Design: This review is an update of a previous systematic review investigating the relationship between lumbar spine MRI findings and future LBP.

Participants: People with or without LBP with lumbar MRI scans.

Outcome Measures: MRI findings, pain and disability.

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Background: General medical practitioner (GP) recruitment and subsequent data collection in clinical practice are challenging and may limit successful completion of a large-scale trial. The aim of this study was to assess the feasibility of undertaking a cluster randomised controlled trial to test an intervention to reduce non-indicated imaging for low back pain in general medical practice.

Methods: A pilot cluster randomised controlled trial was performed, with recruitment of GPs and randomisation of GP clinics.

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Background: Imaging is overused in the management of low back pain, resulting in overdiagnosis, increased healthcare utilisation, and increased costs. Few effective interventions to decrease inappropriate use have been developed and have typically not been developed using behaviour change theory. An intervention to reduce non-indicated imaging for low back pain was developed using behavioural change theory, incorporating a novel low back pain management booklet to facilitate patient education and reassurance.

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Incisional hernia represents a common and potentially serious complication of open abdominal surgery, with up to 20% of all patients undergoing laparotomy subsequently developing an incisional hernia. This incidence increases to as much as 35% for laparotomies performed in high-risk patients and emergency procedures. A rarely used technique for enabling closure of large ventral hernias with loss of domain is (PPP), which uses intermittent insufflation to gradually stretch the contracted abdominal wall muscles, increasing the capacity of the abdominal cavity and allowing viscera to re-establish right of domain.

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Background: The importance of lumbar findings on magnetic resonance imaging (MRI) remains controversial. Changes in lumbar MRI findings over time may provide important insights into the causes of low back pain. However, the reliability and validity of temporal changes are unknown.

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Asthma is characterized by heterogeneous ventilation as measured by three-dimensional ventilation imaging. Combination inhaled corticosteroid/long-acting β-agonist (ICS/LABA) treatment response is variable in asthma, and effects on regional ventilation are unknown. Our aims were to determine whether regional ventilation defects decrease after ICS/LABA treatment and whether small airways dysfunction predicts response in uncontrolled asthma.

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Background: Molecular characterization of glioma has implications for prognosis, treatment planning, and prediction of treatment response. Current histopathology is limited by intratumoral heterogeneity and variability in detection methods. Advances in computational techniques have led to interest in mining quantitative imaging features to noninvasively detect genetic mutations.

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CT scans of an unnamed mummified adult from Egypt, now in the Chau Chak Wing Museum, University of Sydney (NMR.27.3), reveal it to be fully sheathed in a mud shell or carapace, exposing a mortuary treatment not previously documented in the Egyptian archaeological record.

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Purpose: Accurate brain tumor segmentation on magnetic resonance imaging (MRI) has wide-ranging applications such as radiosurgery planning. Advances in artificial intelligence, especially deep learning (DL), allow development of automatic segmentation that overcome the labor-intensive and operator-dependent manual segmentation. We aimed to evaluate the accuracy of the top-performing DL model from the 2018 Brain Tumor Segmentation (BraTS) challenge, the impact of missing MRI sequences, and whether a model trained on gliomas can accurately segment other brain tumor types.

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Background: Cranial and spinal epidermoid cysts (ECs) are rare and surgical resection can be complicated by chemical meningitis. Here, we treated a patient undergoing surgical resection of an intramedullary spinal EC with prophylactic steroids to help prevent postoperative chemical meningitis. Notably, we found a paucity of evidence regarding the efficacy of steroids used for this purpose.

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A sensitive test for Superior Semicircular Canal Dehiscence (SCD) is the air-conducted, ocular vestibular evoked myogenic potential (AC oVEMP). However, not all patients with large AC oVEMPs have SCD. This retrospective study sought to identify alternate diagnoses also producing enlarged AC oVEMPs and investigated bone-conducted (BC) oVEMP outcome measures that would help differentiate between these, and cases of SCD.

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A 60-year-old man presented to hospital with bilateral lower limb weakness, urinary retention and constipation. He had been diagnosed with COVID-19 10 days prior. Clinical examination revealed global weakness, increased tone, hyperreflexia and patchy paresthesia in his lower limbs bilaterally.

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A 63-year-old man presented with imbalance when coughing due to a respiratory tract infection. He had a history of multiple myeloma with a plasmacytoma of the left temporal bone. Examination revealed a positive leftward head impulse test, no spontaneous nystagmus, left-beating positional nystagmus, and left-beating Valsalva-induced nystagmus.

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Gonadotropinoma in Klinefelter syndrome (KS) is uncommon and may be a result of protracted stimulation of gonadotrophs from lack of androgen feedback. Associations of white matter changes and increased venous thromboembolic risk have been reported and need to be considered in patients with KS.

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Objective: This research was designed to examine the contribution of self-reported experience and cue utilization to diagnostic accuracy in the context of radiology.

Background: Within radiology, it is unclear how task-related experience contributes to the acquisition of associations between features with events in memory, or cues, and how they contribute to diagnostic performance.

Method: Data were collected from 18 trainees and 41 radiologists.

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Background: In the era of integrated genomic-histologic analysis of brain tumors, new biomarkers have been introduced as diagnostic, prognostic, and therapeutic indicators. The analysis of the mutation in the isocitrate dehydrogenase (IDH) genes IDH1 and IDH2 has provided important diagnostic and prognostic information for patients affected by diffuse glioma (i.e.

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Objective: The pathogenesis of Chiari malformation type 1 (CM-1)-associated Valsalva headache is unknown, but it may be caused by abnormal cerebellar tonsil tissue strain. Advances in cardiac-gated magnetic resonance imaging (MRI) techniques such as balanced fast-field echo (bFFE) allow quantification of the motion of anatomic structures and can be used to measure tissue strain. The current study investigated the relationship between Valsalva heachache and tonsillar motion in patients with CM-1.

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Background: Imaging is overused in the management of low back pain (LBP). Interventions designed to decrease non-indicated imaging have predominantly targeted practitioner education alone; however, these are typically ineffective. Barriers to reducing imaging have been identified for both patients and practitioners.

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