Persistent postsurgical pain (PPP) is common following thoracotomy. Thoracic epidural (TEB) and paravertebral blockade (PVB) are both established forms of perioperative analgesia for thoracotomy. ...There is currently a lack of data on their influence on PPP; this study aims to evaluate both techniques on PPP.
Observational study, prospectively collected data.
Adults who underwent thoracotomy had either TEB or PVB for analgesia and were prospectively interviewed at six months. A numerical rating scale, the short form of the Leeds Assessment of Neuropathic Symptoms and Signs, and the EuroQol-5 dimension (EQ-5D) index were used to assess pain, neuropathic pain, and quality of life.
Eighty-two patients who underwent a thoracotomy were recruited (TEB N = 36, PVB N = 46). Pain scores had a median (interquartile range IQR) of 1 (0 to 4.5) and 1.5 (0 to 4, P = 0.89), presence of PPP was 58.3% (95% confidence interval CI = 40.0-74.5%) and 60.9% (95% CI = 45.4-74.9%, P = 0.81), and presence of neuropathic pain was 30.6% (95% CI = 16.3-48.1%) and 28.2% (95% CI = 16.0-43.5%, P = 0.85). Reported quality of life was 0.71 (0.14-0.85) and 0.80 (0.19-0.91, P = 0.21). Patients who had PPP reported worse quality of life measures compared with those who were pain free, with a median (IQR) EQ-5D index of 0.69 (-0.15 to 0.85) and 0.85 (0.72 to 1, P = 0.0007); quality of life was worst when there was a neuropathic component (median = 0.39, IQR = -0.24 to 0.75).
There was no statistical difference in the development of persistent postsurgical pain between patients who received a TEB or a PVB; however, patients who developed PPP had a significantly lower quality of life, which was worse with a neuropathic component.
London Trauma Conference 2015 : London, UK, 8-11 December 2015 Avery, Pascale; Salm, Leopold; Bird, Flora ...
Scandinavian journal of trauma, resuscitation and emergency medicine,
2016-Jun-17, 2016-6-17, 20160617, Volume:
24 Suppl 1, Issue:
S1
Journal Article
Peer reviewed
Open access
I1: Trauma, Pre-hospital and Cardiac Arrest Care 2015
Pascale Avery, Leopold Salm, Flora Bird
A1: Retrospective evaluation of HEMS ‘Direct to CT’ protocol
Anja Hutchinson, Ashley Matthies, Anthony ...Hudson, Heather Jarman
A2 Rush hour – Crush hour: temporal relationship of cyclist vs. HGV trauma admissions. A single site observational study
Maria Bergman Nilsson, Tom Konig, Nigel Tai
A3 Semiprone position endotracheal intubation during continuous cardiopulmonary resuscitation in drowned children with regurgitation: a case report and experimental manikin study
Espen Fevang, Børge Hognestad, Håkon B. Abrahamsen
A4 An audit of CO2 A-a gradient in non-trauma patients receiving pre-hospital anaesthesia
Olivia V Cheetham, Matthew JC Thomas, Kieron D Rooney
A5 Can the use of c-spine immobilisation collars be avoided in non-trauma patients presenting to the Emergency Department?
Josephine Murray, Malcolm Tunnicliff
A6 Curriculum mapping in ED point of care simulation
Joseph W Collinson, Thomas Brown, Christopher Pritchett
A7 Point of care multidisciplinary trauma team simulation & participant satisfaction in a geographically remote trauma unit in Cornwall
Christopher SA Pritchett, Mark Jadav, Gareth Meredith, Jamie Plumb, Steve Harris, Roger Langford
A8 Conservative management of head injury inpatients - the challenge of simplifying injury management in a non-neurosurgical hospital
JG Hunter, A Sage, R Madden, O Flamank, B Broadbent, S Marsh, H Lewis, E Daniels, N Roberts
A9 Improving the care of traumatic brain injury at non-neurosurgical hospitals: Introducing a head injury pathway and single place of care is associated with significant improvements in neurological observation
JG Hunter, A Sage, R Madden, O Flamank, B Broadbent, S Marsh, H Lewis, E Daniels, N Lin, N Roberts
A10 The experience of inter-disciplinary students undertaking cardiac arrest moulage training
Samuel Bulford, Silas Houghton-Budd, Sam Pearson, Megan Clear-Hill
A11 Impact brain apnoea – nine cases
David J Menzies, James P Leonard, Conor Keogh, Ray Quinn, John D Hinds
A12 Time well spent? Improving the performance improvement programme in a busy Trauma Unit
N Roberts, D Ashton-Cleary, M Jadav
A14 Clinical significant and outcome of pulmonary contusions in patients with blunt chest trauma
Ismail Mahmood, Ayman El-Menyar, Basil Younis, Ahmed Khalid, Syed Nabir, Mohamed Nadeem Ahmed, Omer Al-Yahri, Hassan Al-Thani
A15 Plastics operative workload in major trauma centres: a national prospective survey
Katie Young, Susan A. Hendrickson, Georgina Phillips, Matthew D. Gardiner, Shehan Hettiaratchy
A16 A survey to assess the accuracy of estimating height by pre-hospital clinicians: can we reliably predict those most at risk of serious injury?
Alexandra Alice Crossland, Anthony Hudson
A17 An audit of the cause, outcome and adherence to treatment Standard Operating Procedure (SOP) for all traumatic cardiac arrests at a Helicopter Emergency Medical Service over a 12-month period
Nicholas C Brassington, Anthony Hudson, Emily McWhirter
A18 Should we “stay-and-play? A study of patient physiology in Norwegian Helicopter Emergency Services
Bjørn O Reid, Marius Rehn, Oddvar Uleberg, Andreas J Krüger
A19 Training in resuscitative thoracotomy: have we cracked it? A survey of higher Emergency Medicine trainees in London
Cara Jennings, Yasmin Kapadia, Duncan Bew
A20 London’s Air Ambulance (LAA): 25-years of drownings in an urban environment
Jenny Townsend, Tom P Hurst, Elizabeth A Foster
A21 Live patients in trauma simulation – more than just simulation on a shoestring?
Thomas B Brown, Joseph Collinson, Christopher Pritchett, Toby Slade
A22 Collecting core data in pre-hospital critical care using a consensus based template
Kristin Tønsager, Marius Rehn, Kjetil G.Ringdal, Andreas J.Krüger
A23 Prehospital interventions before and after implementation of a physician staffed helicopter
Rasmus Hesselfeldt, Sandra Wulffeld, Asger Sonne, Lars S. Rasmussen, Jacob Steinmetz
A24 Duration of ventilation following prehospital drug assisted intubation; a retrospective review
Thomas J Renninson, Nadine Thomson, Harvey Pynn, Timothy J Hooper
A25 Non-haemorrhagic shock in trauma: a novel guideline for management in ED
Anthony Hudson, Jacinta Dawson, Ashley Matthies
A26 Patient-tailored triage decisions by anaesthetist-staffed pre-hospital critical care teams
Morten Langfeldt Friberg, Leif Rognås
A27 Anatomical accuracy and appropriate sizing of pre-hospital thoracostomies
Jessica FG Wills, Anthony Hudson
A28 Pre-hospital management of mass casualty civilian shootings
Conor DA Turner, Marius Rehn
A30 The prevalence of alcohol-related trauma recidivism: a systematic review
James Nunn, Mete Erdogan, Robert S. Green
A31 Development of a hospital-wide program for simulation-based training in trauma care and management
Samuel Minor, Mete Erdogan, Kathy Hartlen, Robert S. Green
A32 Out of Hospital Cardiac Arrests (OOHCA); lessons from Hollywood
Ruth Bird, Rachael L. Grupping
A33 Mechanism of injury as a predictor of severity of injury in road traffic collisions: a literature review
Amelia M. Stacey, Marius Rehn, David J. Lockey
A34 Lessons to be learned from prehospital airway intervention documentation? Are airway intervention documentation templates as successful in-hospital as prehospitally?
S. Abiks, L. Cutler, K. Monaghan, A. Al-Rais, C. Hymers, R. Bloomer, Y. Kapadia
A35 Novel biomarkers in
pre
hospital management of
t
raumatic
b
rain
i
njury (the PreTBI study protocol)
Sophie-Charlott Seidenfaden, Ingunn S. Riddervold, Hans Kirkegaard, Niels Juul, Morten T. Bøtker
A36 Hospital outcomes of traumatic railway incidents: a seven-year observational retrospective study of a major trauma centre
Alice Gao, Zane Perkins; Gareth Grier, Alex Tzannes
A37 Does taking a third crew member affect the on-scene time of HEMS jobs?
Nathan Hudson-Peacock, Quentin Otto, Laurie Phillipson, Rik Thomas, Ainsley Heyworth
A38 Does pre-hospital rapid sequence induction affect on-scene time of HEMS jobs?
Quentin Otto, Nathan Hudson-Peacock, Laurie Phillipson, Ainsley Heyworth, Erica Ley
A39 Code red: shock index as a prehospital indicator of massive haemorrhage
Daniel Banner, Ainsley Heyworth, Erica Ley
A40 Air ambulance tasking: how accurate are our current methods?
Madeleine Benson, Nathan Hudson-Peacock, Tony Stone, Erica Ley, Louise Rousson, Ainsley Heyworth
A41 Modern trauma burden in a district general hospital
Beth A Lineham, Matthew J Lee, Martin Gough
A42 Establishing a legal service for major trauma patients in two UK major trauma centres
William H Seligman, Hannah E Thould, Andrew Dinsmore, Charlotte Tan, Julian Thompson, C Andy Eynon, David J Lockey
A43 Prehospital assessment and care of patients – a study of the use of guidelines when assessing head trauma
Rebecka M Rubenson Wahlin, Veronica Lindström, Sari Ponzer, Veronica Vicente
A44 An audit of pre-hospital blood pressure management resulting from head injury
Pamela Eligio, Anthony Hudson
A45 The surgical contribution of surface shading volumetric rendering techniques in rib fracture management
Robert Young, Dimitri Amiras, Ian Sinha
London Trauma Conference 2015 Rognås, Leif; Younis, Basil; Madden, R ...
Scandinavian journal of trauma, resuscitation and emergency medicine,
06/2016, Volume:
24, Issue:
Suppl 1
Journal Article
Peer reviewed
Open access
Table of contents I1: Trauma, Pre-hospital and Cardiac Arrest Care 2015 Pascale Avery, Leopold Salm, Flora Bird A1: Retrospective evaluation of HEMS 'Direct to CT' protocol Anja Hutchinson, Ashley ...Matthies, Anthony Hudson, Heather Jarman A2 Rush hour - Crush hour: temporal relationship of cyclist vs. HGV trauma admissions. A single site observational study Maria Bergman Nilsson, Tom Konig, Nigel Tai A3 Semiprone position endotracheal intubation during continuous cardiopulmonary resuscitation in drowned children with regurgitation: a case report and experimental manikin study Espen Fevang, Barge Hognestad, HÃ¥kon B. Abrahamsen A4 An audit of CO2 A-a gradient in non-trauma patients receiving pre-hospital anaesthesia Olivia V Cheetham, Matthew JC Thomas, Kieron D Rooney A5 Can the use of c-spine immobilisation collars be avoided in non-trauma patients presenting to the Emergency Department? Josephine Murray, Malcolm Tunnicliff A6 Curriculum mapping in ED point of care simulation Joseph W Collinson, Thomas Brown, Christopher Pritchett A7 Point of care multidisciplinary trauma team simulation & participant satisfaction in a geographically remote trauma unit in Cornwall Christopher SA Pritchett, Mark Jadav, Gareth Meredith, Jamie Plumb, Steve Harris, Roger Langford A8 Conservative management of head injury inpatients - the challenge of simplifying injury management in a non-neurosurgical hospital JG Hunter, A Sage, R Madden, O Flamank, B Broadbent, S Marsh, H Lewis, E Daniels, N Roberts A9 Improving the care of traumatic brain injury at non-neurosurgical hospitals: Introducing a head injury pathway and single place of care is associated with significant improvements in neurological observation JG Hunter, A Sage, R Madden, O Flamank, B Broadbent, S Marsh, H Lewis, E Daniels, N Lin, N Roberts A10 The experience of inter-disciplinary students undertaking cardiac arrest moulage training Samuel Bulford, Silas Houghton-Budd, Sam Pearson, Megan Clear-Hill A11 Impact brain apnoea - nine cases David J Menzies, James P Leonard, Conor Keogh, Ray Quinn, John D Hinds A12 Time well spent? Improving the performance improvement programme in a busy Trauma Unit N Roberts, D Ashton-Cleary, M Jadav A14 Clinical significant and outcome of pulmonary contusions in patients with blunt chest trauma Ismail Mahmood, Ayman El-Menyar, Basil Younis, Ahmed Khalid, Syed Nabir, Mohamed Nadeem Ahmed, Omer Al-Yahri, Hassan Al-Thani A15 Plastics operative workload in major trauma centres: a national prospective survey Katie Young, Susan A. Hendrickson, Georgina Phillips, Matthew D. Gardiner, Shehan Hettiaratchy A16 A survey to assess the accuracy of estimating height by pre-hospital clinicians: can we reliably predict those most at risk of serious injury? Alexandra Alice Crossland, Anthony Hudson A17 An audit of the cause, outcome and adherence to treatment Standard Operating Procedure (SOP) for all traumatic cardiac arrests at a Helicopter Emergency Medical Service over a 12-month period Nicholas C Brassington, Anthony Hudson, Emily McWhirter A18 Should we "stay-and-play? A study of patient physiology in Norwegian Helicopter Emergency Services Bjarn O Reid, Marius Rehn, Oddvar Uleberg, Andreas J Krüger A19 Training in resuscitative thoracotomy: have we cracked it? A survey of higher Emergency Medicine trainees in London Cara Jennings, Yasmin Kapadia, Duncan Bew A20 London's Air Ambulance (LAA): 25-years of drownings in an urban environment Jenny Townsend, Tom P Hurst, Elizabeth A Foster A21 Live patients in trauma simulation - more than just simulation on a shoestring? Thomas B Brown, Joseph Collinson, Christopher Pritchett, Toby Slade A22 Collecting core data in pre-hospital critical care using a consensus based template Kristin Tansager, Marius Rehn, Kjetil G.Ringdal, Andreas J.Krüger A23 Prehospital interventions before and after implementation of a physician staffed helicopter Rasmus Hesselfeldt, Sandra Wulffeld, Asger Sonne, Lars S. Rasmussen, Jacob Steinmetz A24 Duration of ventilation following prehospital drug assisted intubation; a retrospective review Thomas J Renninson, Nadine Thomson, Harvey Pynn, Timothy J Hooper A25 Non-haemorrhagic shock in trauma: a novel guideline for management in ED Anthony Hudson, Jacinta Dawson, Ashley Matthies A26 Patient-tailored triage decisions by anaesthetist-staffed pre-hospital critical care teams Morten Langfeldt Friberg, Leif RognÃ¥s A27 Anatomical accuracy and appropriate sizing of pre-hospital thoracostomies Jessica FG Wills, Anthony Hudson A28 Pre-hospital management of mass casualty civilian shootings Conor DA Turner, Marius Rehn A30 The prevalence of alcohol-related trauma recidivism: a systematic review James Nunn, Mete Erdogan, Robert S. Green A31 Development of a hospital-wide program for simulation-based training in trauma care and management Samuel Minor, Mete Erdogan, Kathy Hartlen, Robert S. Green A32 Out of Hospital Cardiac Arrests (OOHCA); lessons from Hollywood Ruth Bird, Rachael L. Grupping A33 Mechanism of injury as a predictor of severity of injury in road traffic collisions: a literature review Amelia M. Stacey, Marius Rehn, David J. Lockey A34 Lessons to be learned from prehospital airway intervention documentation? Are airway intervention documentation templates as successful in-hospital as prehospitally? S. Abiks, L. Cutler, K. Monaghan, A. Al-Rais, C. Hymers, R. Bloomer, Y. Kapadia A35 Novel biomarkers in prehospital management of traumatic brain injury (the PreTBI study protocol) Sophie-Charlott Seidenfaden, Ingunn S. Riddervold, Hans Kirkegaard, Niels Juul, Morten T. Batker A36 Hospital outcomes of traumatic railway incidents: a seven-year observational retrospective study of a major trauma centre Alice Gao, Zane Perkins; Gareth Grier, Alex Tzannes A37 Does taking a third crew member affect the on-scene time of HEMS jobs? Nathan Hudson-Peacock, Quentin Otto, Laurie Phillipson, Rik Thomas, Ainsley Heyworth A38 Does pre-hospital rapid sequence induction affect on-scene time of HEMS jobs? Quentin Otto, Nathan Hudson-Peacock, Laurie Phillipson, Ainsley Heyworth, Erica Ley A39 Code red: shock index as a prehospital indicator of massive haemorrhage Daniel Banner, Ainsley Heyworth, Erica Ley A40 Air ambulance tasking: how accurate are our current methods? Madeleine Benson, Nathan Hudson-Peacock, Tony Stone, Erica Ley, Louise Rousson, Ainsley Heyworth A41 Modern trauma burden in a district general hospital Beth A Lineham, Matthew J Lee, Martin Gough A42 Establishing a legal service for major trauma patients in two UK major trauma centres William H Seligman, Hannah E Thould, Andrew Dinsmore, Charlotte Tan, Julian Thompson, C Andy Eynon, David J Lockey A43 Prehospital assessment and care of patients - a study of the use of guidelines when assessing head trauma Rebecka M Rubenson Wahlin, Veronica Lindström, Sari Ponzer, Veronica Vicente A44 An audit of pre-hospital blood pressure management resulting from head injury Pamela Eligio, Anthony Hudson A45 The surgical contribution of surface shading volumetric rendering techniques in rib fracture management Robert Young, Dimitri Amiras, Ian Sinha
Strigolactones have recently been implicated in both above- and below-ground developmental pathways in higher plants. To facilitate the molecular and chemical properties of strigolactones in vitro ...and in vivo, we have devel- oped a fluorescent strigolactone molecule, CISA-1, synthesized via a novel method which was robust, high-yielding, and used simple starting materials. We demonstrate that CISA-1 has a broad range of known strigolactone activities and further report on an adventitious rooting assay in Arabidopsis which is a highly sensitive and rapid method for testing biological activity of strigolactone analogs. In this rooting assay and the widely used Orobanche germination assay, CISA-1 showed stronger biological activity than the commonly tested GR24. CISA-1 and GR24 were equally effective at inhibiting branching in Arabidopsis inflorescence stems. In both the branching and adventitious rooting assay, we also demonstrated that CISA-1 activity is dependent on the max strigolactone signaling pathway. In water methanol solu- tions, CISA-1 was about threefold more stable than GR24, which may contribute to the increased activity observed in the various biological tests.
The aim of this study was to evaluate whether soluble frizzled-related protein 4 (sFRP4) concentration in the first trimester of pregnancy is individually, or in combination with Leptin, Chemerin ...and/or Adiponectin, associated with the development of gestational diabetes (GDM).
In a nested case-control study, 50 women with GDM who spontaneously conceived and delivered a live-born infant were matched with a total of 100 uncomplicated singleton control pregnancies based on body mass index (± 2 kg/m2), gestational age at sampling (exact day) and maternal age (± 2 years). In serum samples, obtained between 70-90 days gestational age, sFRP4, Chemerin, Leptin and Adiponectin concentrations were determined by ELISA. Statistical comparisons were performed using univariate and multi-variate logistic regression analysis after logarithmic transformation of the concentrations. Discrimination of the models was assessed by the area under the curve (AUC).
First trimester sFRP4 concentrations were significantly increased in GDM cases (2.04 vs 1.93 ng/ml; p<0.05), just as Chemerin (3.19 vs 3.15 ng/ml; p<0.05) and Leptin (1.44 vs 1.32 ng/ml; p<0.01). Adiponectin concentrations were significantly decreased (2.83 vs 2.94 ng/ml; p<0.01) in GDM cases. Further analysis only showed a weak, though significant, correlation of sFRP4 with Chemerin (R2 = 0.124; p<0.001) and Leptin (R2 = 0.145; p<0.001), and Chemerin with Leptin (R2 = 0.282; p<0.001) in the control group. In a multivariate logistic regression model of these four markers, only Adiponectin showed to be significantly associated with GDM (odds ratio 0.12, 95%CI 0.02-0.68). The AUC of this model was 0.699 (95%CI 0.605-0.793).
In the first trimester of pregnancy, a multi-marker model with sFRP4, Leptin, Chemerin and Adiponectin is associated with the development of GDM. Therefore, this panel seems to be an interesting candidate to further evaluate for prediction of GDM in a prospective study.
A decrease in sodium intake has been shown to lower blood pressure, but data from cohort studies on the association with cardiovascular and renal outcomes are inconsistent. In these studies, sodium ...intake was often estimated with a single baseline measurement, which may be inaccurate considering day-to-day changes in sodium intake and sodium excretion. We compared the effects of single versus repetitive follow-up 24-hour urine samples on the relation between sodium intake and long-term cardiorenal outcomes.
We selected adult subjects with an estimated glomerular filtration rate >60 mL/min/1.73m
, an outpatient 24-hour urine sample between 1998 and 1999, and at least 1 collection during a 17-year follow-up. Sodium intake was estimated with a single baseline collection and the average of samples collected during a 1-, 5-, and 15-year follow-up. We used Cox regression analysis and the landmark approach to investigate the relation between sodium intake and cardiovascular (cardiovascular events or mortality) and renal (end-stage renal disease: dialysis, transplantation, and/or >60% estimated glomerular filtration rate decline, or mortality) outcomes.
We included 574 subjects with 9776 twenty-four-hour urine samples. Average age was 47 years, and 46% were male. Median follow-up was 16.2 years. Average 24-hour sodium excretion, ranging from 3.8 to 3.9 g (165-170 mmol), was equal among all methods (
=0.88). However, relative to a single baseline measurement, 50% of the subjects had a >0.8-g (>34-mmol) difference in sodium intake with long-term estimations. As a result, 45%, 49%, and 50% of all subjects switched between tertiles of sodium intake when the 1-, 5-, or 15-year average was used, respectively. Consequently, hazard ratios for cardiorenal outcome changed up to 85% with the use of sodium intake estimations from short-term (1-year) and long-term (5-year) follow-up instead of baseline estimations.
Relative to a single baseline 24-hour sodium measurement, the use of subsequent 24-hour urine samples resulted in different estimations of an individual's sodium intake, whereas population averages remained similar. This finding had significant consequences for the association between sodium intake and long-term cardiovascular and renal outcomes.
TGF-β1 signaling is a critical driver of collagen accumulation and fibrotic disease but also a vital suppressor of inflammation and epithelial cell proliferation. The nature of this multifunctional ...cytokine has limited the development of global TGF-β1 signaling inhibitors as therapeutic agents. We conducted phenotypic screens for small molecules that inhibit TGF-β1-induced epithelial-mesenchymal transition without immediate TGF-β1 receptor (TβR) kinase inhibition. We identified trihydroxyphenolic compounds as potent blockers of TGF-β1 responses (IC50 ~50 nM), Snail1 expression, and collagen deposition in vivo in models of pulmonary fibrosis and collagen-dependent lung cancer metastasis. Remarkably, the functional effects of trihydroxyphenolics required the presence of active lysyl oxidase-like 2 (LOXL2), thereby limiting effects to fibroblasts or cancer cells, the major LOXL2 producers. Mechanistic studies revealed that trihydroxyphenolics induce auto-oxidation of a LOXL2/3-specific lysine (K731) in a time-dependent reaction that irreversibly inhibits LOXL2 and converts the trihydrophenolic to a previously undescribed metabolite that directly inhibits TβRI kinase. Combined inhibition of LOXL2 and TβRI activities by trihydrophenolics resulted in potent blockade of pathological collagen accumulation in vivo without the toxicities associated with global inhibitors. These findings elucidate a therapeutic approach to attenuate fibrosis and the disease-promoting effects of tissue stiffness by specifically targeting TβRI kinase in LOXL2-expressing cells.
This document outlines recommendations for physiotherapy management for COVID-19 in the acute hospital setting. It includes: recommendations for physiotherapy workforce planning and preparation; a ...screening tool for determining requirement for physiotherapy; and recommendations for the selection of physiotherapy treatments and personal protective equipment. It is intended for use by physiotherapists and other relevant stakeholders in the acute care setting caring for adult patients with confirmed or suspected COVID-19.
Purpose
Alzheimer’s disease (AD) is the most common form of dementia. Clinically, it is characterized by progressive cognitive and functional impairment with structural hallmarks of cortical atrophy ...and ventricular expansion. Amyloid plaque aggregation is also known to occur in AD subjects. In-vivo imaging of amyloid plaques is now possible with positron emission tomography (PET) radioligands. PET imaging suffers from a degrading phenomenon known as the partial volume effect (PVE). The quantitative accuracy of PET images is reduced by PVEs primarily due to the limited spatial resolution of the scanner. The degree of PVE is influenced by structure size, with smaller structures tending to suffer from more severe PVEs such as atrophied grey matter regions. The aims of this paper were to investigate the effect of partial volume correction (PVC) on the quantification of amyloid PET and to highlight the importance of selecting an appropriate PVC technique.
Methods
An improved PVC technique, region-based voxel-wise (RBV) correction, was compared against existing Van-Cittert (VC) and Müller-Gärtner (MG) methods using amyloid PET imaging data. Digital phantom data were produced using segmented MRI scans from a control subject and an AD subject. Typical tracer distributions were generated for each of the phantom anatomies. Also examined were 70 clinical PET scans acquired using
18
Fflutemetamol. Volume of interest (VOI) analysis was performed for corrected and uncorrected images.
Results
PVC was shown to improve the quantitative accuracy of regional analysis performed on amyloid PET images. Of the corrections applied, VC deconvolution demonstrated the worst recovery of grey matter values. MG PVC was shown to induce biases in some grey matter regions due to grey matter variability. In addition, white matter variability was shown to influence the accuracy of MG PVC in cortical grey matter and also cerebellar grey matter, a typical reference region for amyloid PET normalization in sporadic AD. RBV was shown to be more accurate than MG in terms of grey matter and white matter uptake. An increase in within-group variability after PVC was observed and is believed to be a genuine, more accurate representation of the data rather than a correction-induced error. The standardized uptake value ratio (SUVR) threshold for classifying subjects as either amyloid-positive or amyloid-negative was found to be 1.64 in the uncorrected dataset, rising to 2.25 after PVC.
Conclusion
Care should be taken when applying PVC to amyloid PET images. Assumptions made in existing PVC strategies can induce biases that could lead to erroneous inferences about uptake in certain regions. The proposed RBV PVC technique accounts for within-compartment variability, with the potential to reduce errors of this kind.
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