Effects of Blood Pressure on Brain Tissue Pulsation Amplitude in a Phantom Model.

Objective: The precise mechanism and determinants of brain tissue pulsations (BTPs) are poorly understood, and the impact of blood pressure (BP) on BTPs is relatively unexplored. This study aimed to explore the relationship between BP parameters (mean arterial pressure [MAP] and pulse pressure [PP]) and BTP amplitude, using a transcranial tissue Doppler prototype.

Methods: A phantom brain model generating arterial-induced BTPs was developed to observe BP changes in the absence of confounding variables and cerebral autoregulation feedback processes.

Improving communications in PPE: a solution for 'landline' telephone communication.

Background: Emergency care staff wearing elastomeric respiratory personal protective equipment (PPE) report difficulties in communicating by telephone. We developed and tested an affordable technological solution aimed at improving telephone call intelligibility for staff wearing PPE.

Methods: A novel headset was created to enable a throat microphone and bone conduction headset to be used in combination with a standard hospital 'emergency alert' telephone system.

Are portable ankle brachial pressure index measurement devices suitable for hypertension screening?

Objective: In a large-scale population cardiovascular screening programme, peripheral artery disease (PAD) and hypertension would ideally be rapidly assessed using a single device. The ankle-brachial pressure index (ABPI) is calculated by comparing the ankle and brachial blood pressure (BP). However, it is currently unclear whether brachial BP measurements provided by automated PAD screening systems are sufficiently accurate for simultaneous hypertension screening.

Magnetic resonance imaging of the pulsing brain: a systematic review.

Objective: To perform a systematic review of the literature exploring magnetic resonance imaging (MRI) methods for measuring natural brain tissue pulsations (BTPs) in humans.

Methods: A prospective systematic search of MEDLINE, SCOPUS and OpenGrey databases was conducted by two independent reviewers using a pre-determined strategy. The search focused on identifying reported measurements of naturally occurring BTP motion in humans.

Development of a Flow Phantom for Transcranial Doppler Ultrasound Quality Assurance.

Anecdotal evidence was recently brought to our attention suggesting a potential difference in velocity estimates between transcranial Doppler (TCD) systems when measuring high velocities (∼200 cm/s) close to the threshold for sickle cell disease stroke prevention. As we were unable to identify a suitable commercial TCD phantom, a middle cerebral artery (MCA) flow phantom was developed to evaluate velocity estimates from different devices under controlled conditions. Time-averaged velocity estimates were obtained using two TCD devices: a Spencer Technologies ST Doppler system (ST PMD150, Spencer Technologies, Seattle, WA, USA) and a DWL Dopplerbox (DWL Compumedics, SN-300947, Singen, Germany).

Selecting Portable Ankle/Toe Brachial Pressure Index Systems for a Peripheral Arterial Disease Population Screening Programme: a Systematic Review, Clinical Evaluation Exercise, and Consensus Process.

Objective: To provide an overview of systems available for peripheral arterial disease (PAD) screening, together with respective accuracies and a clinical evaluation to identify a system suitable for use in a community screening programme.

Methods: A systematic review of the diagnostic accuracy of six ankle brachial pressure index (ABPI) and toe brachial pressure index (TBPI) devices deemed to be portable, which were Conformité Européenne (CE) marked, and were automated or semi-automated was carried out compared with gold standard handheld Doppler and duplex ultrasound. The devices were MESI-ABPI-MD, Huntleigh Dopplex Ability, Huntleigh ABPI and TBPI systems, Systoe TBPI system, and BlueDop.

Paediatric brain MRI findings following congenital heart surgery: a systematic review.

Objective: This systematic review aimed to establish the relative incidence of new postoperative brain MRI findings following paediatric congenital cardiac surgery.

Design: To distinguish perioperative changes from pre-existing MR findings, our systematic search strategy focused on identifying original research studies reporting both presurgery and postsurgery brain MRI scans. Patient demographics, study methods and brain MR findings were extracted.

Emerging Detection Techniques for Large Vessel Occlusion Stroke: A Scoping Review.

Large vessel occlusion (LVO) is the obstruction of large, proximal cerebral arteries and can account for up to 46% of acute ischaemic stroke (AIS) when both the A2 and P2 segments are included (from the anterior and posterior cerebral arteries). It is of paramount importance that LVO is promptly recognised to provide timely and effective acute stroke management. This review aims to scope recent literature to identify new emerging detection techniques for LVO.

Survey of the publics' preferences for communication of medical radiation risk.

To comply with the Ionising Radiations (Medical Exposures) Regulations 2017, patients need to be adequately informed of medical radiation risks prior to exposure. This study used a survey developed in partnership with patients and members of the public to explore patient preferences for radiation risk communication. It was distributed through social media between 28/4/2020 and 18/7/2020.

Ultrasound shear wave elastography imaging of common carotid arteries in patients with Spontaneous Coronary Artery Dissection (SCAD).

Background: Shear wave elastography (SWE) is emerging as a valuable clinical tool for a variety of conditions. The aim of this pilot study was to assess the potential of SWE imaging of the common carotid arteries (CCA) in patients with spontaneous coronary artery dissection (SCAD), a rare but potentially life-threatening condition, hypothesized to be linked to changes in vessel wall elasticity.

Methods: Ultrasound shear wave elastography (SWE) estimates of artery wall elasticity were obtained from the left and right CCAs of 89 confirmed SCAD patients and 38 non-dissection controls.

Brain tissue motion in acute hemorrhagic stroke using amplified MRI (aMRI).

Brain tissue pulsates with each cardiac cycle, however the effect of disease on this natural motion is still unclear. Current literature mainly focuses on healthy brain tissue, with only limited studies looking at disease states such as Chiari malformation and acute ischemic stroke. This case report advances on recent literature by describing the case of a patient with an acute intracerebral hemorrhage and demonstrating an amplified MRI cine of the brain's motion.

Does radiology require informed consent for radiation risk?

Recent trends in medical decision-making have moved from paternalistic doctor-patient relations to shared decision-making. Informed consent is fundamental to this process and to ensuring patients' ongoing trust in the health-care profession. It cannot be assumed that patients consent to the risk associated with medical exposures, unless they have been provided with the information to make that decision.

A Novel Elastography Phantom Prototype for Assessment of Ultrasound Elastography Imaging Performance.

The aims of this study were firstly to manufacture and evaluate a novel elastography test phantom and secondly to assess the performance of an elastography system using this phantom. A novel Leicester-St. Thomas' Elastography Pipe (L-STEP) test phantom consisting of five soft polyvinyl acrylic-cryogel pipes of varying diameters (2-12 mm), embedded at 45° within an agar-based tissue-mimicking material was developed.

Neurological impact of emboli during adult cardiac surgery.

Objectives: This study draws on advances in Doppler ultrasound bubble sizing to investigate whether high volumes of macro-bubbles entering the brain during cardiac surgery increase the risk of new cerebral microbleeds (CMBs), ischemic MR lesions, or post-operative cognitive decline (POCD).

Methods: Transcranial Doppler (TCD) ultrasound recordings were analysed to estimate numbers of emboli and macrobubbles (>100 μm) entering the brain during cardiac surgery. Logistic regression was used to explore the hypothesis that emboli characteristics affect the incidence of new brain injuries identified through pre- and post-operative MRI and neuropsychological testing.

Ultrasound measurement of brain tissue movement in humans: A systematic review.

Introduction: It has long been suggested that ultrasound could be used to measure brain tissue pulsations in humans, but potential clinical applications are relatively unexplored. The aim of this systematic review was to explore and synthesise available literature on ultrasound measurement of brain tissue motion in humans.

Methods: Our systematic review was designed to include predefined study selection criteria, quality evaluation, and a data extraction , registered prospectively on PROSPERO (CRD42018114117).

Part II. Comparison of Neurodevelopmental Outcomes Between Normothermic and Hypothermic Pediatric Cardiopulmonary Bypass.

In the previous study we demonstrated that normothermic cardiopulmonary bypass (N-CPB, ≥35°C) provided better early clinical outcomes compared to mild/moderate hypothermic cardiopulmonary bypass (H-CPB, 28-34°C) for congenital heart surgery. In this follow-up study we compare early neurodevelopmental outcomes 2-3 years post-surgery. In this retrospective, non-randomized observational study, the medical notes of children from our previous cohort were reviewed after 2-3 years.

Development of a globally optimised model of the cerebral arteries.

The cerebral arteries are difficult to reproduce from first principles, featuring interwoven territories, and intricate layers of grey and white matter with differing metabolic demand. The aim of this study was to identify the ideal configuration of arteries required to sustain an entire brain hemisphere based on minimisation of the energy required to supply the tissue. The 3D distribution of grey and white matter within a healthy human brain was first segmented from magnetic resonance images.

Perioperative Cerebral Microbleeds After Adult Cardiac Surgery.

Background and Purpose- Cerebral microbleeds (CMBs) have been observed using magnetic resonance imaging in patients with cardiovascular risk factors, cognitive deterioration, small vessel disease, and dementia. They are a well-known consequence of cerebral amyloid angiopathy, chronic hypertension, and diffuse axonal injury, among other causes. However, the frequency and location of new CMBs postadult cardiac surgery, in association with cognition and perioperative risk factors, have yet to be studied.