Dose quantities for measurement and comparison of doses to individual patients in computed tomography (CT).

The dose quantities displayed routinely on CT scanners, the volume averaged CT dose index (CTDI) and dose length product, provide measures of doses calculated for standard phantoms. The American Association of Medical Physics has published conversion factors for the adjustment of CTDIto take account of variations in patient size, the results being termed size-specific dose estimate (SSDE). However, CTDIand SSDE, while useful in comparing and optimising doses from a set procedure, do not provide risk-related information that takes account of the organs and tissues irradiated and associated cancer risks.

Image-based computational fluid dynamics for estimating pressure drop and fractional flow reserve across iliac artery stenosis: A comparison with in-vivo measurements.

Computational Fluid Dynamics (CFD) and time-resolved phase-contrast magnetic resonance imaging (PC-MRI) are potential non-invasive methods for the assessment of the severity of arterial stenoses. Fractional flow reserve (FFR) is the current "gold standard" for determining stenosis severity in the coronary arteries but is an invasive method requiring insertion of a pressure wire. CFD derived FFR (vFFR) is an alternative to traditional catheter derived FFR now available commercially for coronary artery assessment, however, it can potentially be applied to a wider range of vulnerable vessels such as the iliac arteries.

Effective dose in medicine.

The International Commission on Radiological Protection (ICRP) developed effective dose as a quantity related to risk for occupational and public exposure. There was a need for a similar dose quantity linked to risk for making everyday decisions relating to medical procedures. Coefficients were developed to enable the calculation of doses to organs and tissues, and effective doses for procedures in nuclear medicine and radiology during the 1980s and 1990s.

Consensus-Based Technical Recommendations for Clinical Translation of Renal Phase Contrast MRI.

Background: Phase-contrast (PC) MRI is a feasible and valid noninvasive technique to measure renal artery blood flow, showing potential to support diagnosis and monitoring of renal diseases. However, the variability in measured renal blood flow values across studies is large, most likely due to differences in PC-MRI acquisition and processing. Standardized acquisition and processing protocols are therefore needed to minimize this variability and maximize the potential of renal PC-MRI as a clinically useful tool.

Brain imaging factors associated with progression of subcortical hyperintensities in CADASIL over 2-year follow-up.

Background And Purpose: Mutations in the NOTCH3 gene cause cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a cerebral small vessel disease manifesting with stroke, migraine and dementia in adults. The disease displays significant phenotypic variability that is incompletely explained. Early abnormalities in vascular function have been shown in animal models.

ISCEV extended protocol for VEP methods of estimation of visual acuity.

The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for visual evoked potentials (VEPs) describes a minimum procedure for clinical VEP testing and encourages more extensive testing. This ISCEV extended protocol is an extension to the VEP standard. It describes procedures for recording multiple VEPs to a range of sizes of pattern stimuli to establish the VEP spatial frequency limit (threshold) and for relating this limit to visual acuity.

VEP estimation of visual acuity: a systematic review.

Purpose: Visual evoked potentials (VEPs) can be used to measure visual resolution via a spatial frequency (SF) limit as an objective estimate of visual acuity. The aim of this systematic review is to collate descriptions of the VEP SF limit in humans, healthy and disordered, and to assess how accurately and precisely VEP SF limits reflect visual acuity.

Methods: The protocol methodology followed the PRISMA statement.

An Innovative Assessment of the Dynamics of Facial Movements in Surgically Managed Unilateral Cleft Lip and Palate Using 4D Imaging.

Objective: Assess facial asymmetry during maximum smile in patients with surgically managed unilateral cleft lip and palate (UCLP), using a dynamic 3-dimensional (3D) imaging (4-dimensional) system.

Design: Prospective 2 cohort comparative study.

Methods: Twenty-five surgically managed UCLP cases and 75 controls at 8 to 10 years of age were recruited.

Estimation of size-specific dose estimates (SSDE) for paediatric and adults patients based on a single slice.

Volume averaged CT dose index (CTDI) is an important dose index utilized for CT dosimetry. Measurements of CTDI are performed in reference cylindrical phantoms of specified diameters. A size-specific dose estimate (SSDE) has been recommended for assessment of doses delivered to individual patients.

Dosimetric impact of organ at risk daily variation during prostate stereotactic ablative radiotherapy.

Objective: Prostate stereotactic ablative radiotherapy (SABR) delivers large doses using a fast dose rate. This amplifies the effect geometric uncertainties have on normal tissue dose. The aim of this study was to determine whether the treatment dose-volume histogram (DVH) agrees with the planned dose to organs at risk (OAR).

Comparing the interobserver reproducibility of different regions of interest on multi-parametric renal magnetic resonance imaging in healthy volunteers, patients with heart failure and renal transplant recipients.

Objective: To assess interobserver reproducibility of different regions of interest (ROIs) on multi-parametric renal MRI using commercially available software.

Materials And Methods: Healthy volunteers (HV), patients with heart failure (HF) and renal transplant recipients (Tx) were recruited. Localiser scans, T1 mapping and pseudo-continuous arterial spin labelling (pCASL) were performed.

An investigation into the effect of body mass index on the agreement between whole-body fat mass determined by MRI and air-displacement plethysmography.

Objective: To validate MRI fat measurement protocols using purpose built test objects and by comparison with air-displacement plethysmography (ADP) whole-body fat measurements in non-obese subjects.

Methods: Test objects of known fat concentration were used to quantify the accuracy of the MRI measurements. 10 participants with a body mass index in the range 1830 underwent whole-body MRI using two different Dixon-based sequences (LAVA Flex and IDEAL IQ) to obtain an estimate of their whole-body fat mass.

Use of a hand-held spectroradiometer for the measurement of neonatal phototherapy lamp outputs.

The measurement capability of a hand-held spectroradiometer for validation of phototherapy light treatment for neonates is described. This function is compared with that of a double grating monochromator system with photomultiplier detector, where parameters evaluated included wavelength accuracy and accuracy of irradiance within set wavelength intervals - 460 nm to 490 nm and 400 nm to 550 nm. Measurements carried out in a clinical setting revealed that the hand-held spectroradiometer provided an acceptable level of accuracy for determining output characteristics of the phototherapy devices investigated.

Stacked in-plane histology for quantitative validation of non-invasive imaging biomarkers: Application to an infiltrative brain tumour model.

Background: While it is generally agreed that histopathology is the gold standard for assessing non-invasive imaging biomarkers, most validation has been by qualitative visual comparison. To date, the difficulties involved in accurately co-registering histology sections with imaging slices have prevented a voxel-by-voxel assessment of imaging modalities. By contrast with previous studies, which focus on improving the registration algorithms, we have taken the approach of improving the quality of the histological processing and analysis.

Guidance on prevention of unintended and accidental radiation exposures in nuclear medicine.

Nuclear medicine (NM) procedures for diagnosis and treatment of disease are performed routinely in hospitals throughout the world. These involve preparation and administration to patients of pharmaceuticals labelled with radioactive material. The International Atomic Energy Agency (IAEA) and the World Health Organisation highlighted the need for improvement in prevention of medical radiation incidents and accidents in the Bonn Call-for-Action in 2012.

The effect of facial expression on facial symmetry in surgically managed unilateral cleft lip and palate patients (UCLP).

Aim: To evaluate the symmetry of facial expression in surgically managed UCLP patients.

Materials And Methods: The study was conducted on 13 four-year-old children. Facial images were captured at rest and at maximum smile using stereophotogrammetry.

Childhood neurodevelopment after prescription of maintenance methadone for opioid dependency in pregnancy: a systematic review and meta-analysis.

Aim: To systematically review and meta-analyse studies of neurodevelopmental outcome of children born to mothers prescribed methadone in pregnancy.

Method: MEDLINE, Embase, and PsycINFO were searched for studies published from 1975 to 2017 reporting neurodevelopmental outcomes in children with prenatal methadone exposure.

Results: Forty-one studies were identified (2283 participants).

Longitudinal 3D Assessment of Facial Asymmetry in Unilateral Cleft Lip and Palate.

Objective: Longitudinal evaluation of asymmetry of the surgically managed unilateral cleft lip and palate (UCLP) to assess the impact of facial growth on facial appearance.

Design: Prospective study.

Setting: Glasgow Dental Hospital and School, University of Glasgow, United Kingdom.

Assessment of regional asymmetry of the face before and after surgical correction of unilateral cleft lip.

This study was carried out on 26 unilateral cleft lip and palate (UCLP) cases with mean age 3.6 ± 0.7 months.

Visualizing Cerebrovascular Autoregulation Insults and Their Association with Outcome in Adult and Paediatric Traumatic Brain Injury.

Objective: The aim of this study is to assess visually the impact of duration and intensity of cerebrovascular autoregulation insults on 6-month neurological outcome in severe traumatic brain injury.

Material And Methods: Retrospective analysis of prospectively collected minute-by-minute intracranial pressure (ICP) and mean arterial blood pressure data of 259 adult and 99 paediatric traumatic brain injury (TBI) patients from multiple European centres. The relationship of the 6-month Glasgow Outcome Scale with cerebrovascular autoregulation insults (defined as the low-frequency autoregulation index above a certain threshold during a certain time) was visualized in a colour-coded plot.

Investigation of the Relationship Between the Burden of Raised ICP and the Length of Stay in a Neuro-Intensive Care Unit.

Objectives: Raised intracranial pressure (ICP) is well known to be indicative of a poor outcome in traumatic brain injury (TBI). This phenomenon was quantified using a pressure time index (PTI) model of raised ICP burden in a paediatric population. Using the PTI methodology, this pilot study is aimed at investigating the relationship between raised ICP and length of stay (LOS) in adults admitted to a neurological intensive care unit (neuro-ICU).

Medical Waveform Format Encoding Rules Representation of Neurointensive Care Waveform Data.

Objective: Technology in neurointensive care units can collect and store vast amounts of complex patient data. The CHART-ADAPT project is aimed at developing technology that will allow for the collection, analysis and use of these big data at the patient's bedside in neurointensive care units. A requirement of this project is to automatically extract and transfer high-frequency waveform data (e.

Safety and feasibility of prostate stereotactic ablative radiotherapy using multimodality imaging and flattening filter free.

Objective: To investigate feasibility and safety of stereotactic ablative radiotherapy in the management of prostate cancer while employing MR/CT fusion for delineation, fiducial marker seeds for positioning and Varian RapidArc with flattening filter free (FFF) delivery.

Methods: 41 patients were treated for low-intermediate risk prostate cancer with initial prostate-specific antigen of ≤20 ng ml, Gleason score 6-7. Patients had MR/CT fusion for delineation of prostate ±seminal vesicles.