COVID-19: using chest CT of major trauma patients to monitor and evaluate the second wave in London and the development of routine monitoring in practice.

AIM: To follow-up previous work evaluating incidental findings of COVID-19 signs on computed tomography (CT) images of major trauma patients to include the second wave prior to any major effects from vaccines. MATERIALS AND METHODS: The study population included all patients admitted following major trauma between 1 January 2020 and 28 February 2021 with CT including the lungs (n=1776). Major trauma patients admitted pre-COVID-19 from alternate months from January 2019 to November 2019 comprised a control group (n=837). The assessing radiologists were blinded to the time period and used double reading in consensus to determine if the patient had signs of COVID-19. Lung appearances were classified as no evidence of COVID-19, minor signs, or major signs. RESULTS: The method successfully tracked the second wave of the COVID-19 pandemic in London. The estimated population affected by the disease based on those with major signs was similar to estimates of the proportion of the population in London with antibodies (around 30% by end February 2021) and the total of major and minor signs produced a much higher figure of 68%, which may include all those with both antibody and just T-cell responses. CONCLUSIONS: Incidental findings on CT from major trauma patients may provide a novel and sensitive way of tracking the virus. It is recommended that all major trauma units include a simple question on signs of COVID-19 to provide an early warning system for further waves.

COVID-19: using chest CT of major trauma patients to monitor and evaluate the effect of lockdown and the importance of household size.

AIM: To use theory and practice to show how disease progression and regression can be described pre- and post-lockdown using an attack-sustain-decline-respite (ASDR) model and investigate how pre-lockdown disease prevalence and household size impacts on the effectiveness of lockdown. MATERIALS AND METHODS: Computed tomography (CT) scans from major trauma patients (considered as a random population sample) from the radiology department of St George's University Hospitals NHS Trust, London, have been used to explore COVID-19 disease at the population level. RESULTS: At lockdown on 23 March 2020 in the catchment area of St George's University Hospitals NHS Trust, an earlier paper showed that there was a high prevalence of disease of >20%. With further follow-up and at the end of lockdown, it have been now estimated that around 57% of the population had been affected, which was similar to that predicted from a simple model based on average household size and prevalence at lockdown. With an average household size of around three persons, there was a 2-week sustain period and a 5-week decline period before the prevalence of the disease returned to background levels. CONCLUSIONS: The present results suggest that the effect of lockdown is dependent on the disease prevalence at the start of lockdown and the average household size. It may therefore be important to lockdown early in an area with a high average household size. This paper is the second in a series of papers to show how radiology measurements of major trauma patients can be used to help monitor the spread of the COVID-19 pandemic.

COVID-19: could CT provide the best population level biomarker? Incidental COVID-19 in major trauma patients suggests higher than predicted rates of infection in London.

AIM: To evaluate incidental findings in major trauma patients, and to explore whether computed tomography (CT) could be used to assess prevalence and estimate disease spread in the general population. MATERIALS AND METHODS: The study population included all patients admitted following major trauma between 1 January 2020 and 30 April 2020 with CT including the lungs (n=523). Major trauma patients admitted pre-COVID-19 from 1-31 January and 1-31 March 2019 comprised a control group (n=252). The assessing radiologists, blinded to the time period, used double reading with consensus to determine if the patient had CT signs of COVID-19. Lung appearances were classified as no evidence of COVID-19; minor signs; or major signs. The proportion of patients with incidental COVID-19 changes was recorded over the study period, and the percentage of the population who had been affected by COVID-19 by the end of April 2020 estimated. RESULTS: CT appearances consistent with COVID-19 began to exceed a background pre-COVID rate in the second week of February and did not decline until 2 weeks after lockdown. By the end of April 2020, approximately 45% of the population had been infected. CONCLUSIONS: CT of major trauma patients can be used to monitor the spread of COVID-19. This novel technique could be used retrospectively or prospectively anywhere where trauma scans are available, to monitor the disease in the local population.

Comparative efficacy of and sequence choice for two oral contrast agents used during MR imaging.

OBJECTIVE: Our objective was to compare the efficacy of a positive and a negative oral contrast agent and to determine the optimal sequence choice for use in pelvic MR imaging. SUBJECTS AND METHODS: We undertook a prospective randomized trial of 57 patients with pelvic cancer who were examined with MR imaging after oral administration of a positive contrast agent (27 patients) or a negative contrast agent (30 patients). T1- and T2-weighted breath-hold and non-breath-hold gradient-recalled echo and turbo spin-echo sequences were obtained. Using the hard-copy images, we graded filling and distention of the small bowel, bowel wall conspicuity, delineation of normal and pathologic structures, and artifacts. RESULTS: Good or excellent small-bowel filling and distention was obtained in 17 patients (63%) receiving the positive agent and in 26 patients (87%) receiving the negative agent, and bowel wall conspicuity was graded good or excellent in 19 patients (70%) and 20 patients (67%), respectively. Normal and pathologic structures were better delineated with the negative agent (20 patients [74%] and 27 patients [90%], respectively; p = .02). Breath-hold gradient-recalled echo T1-weighted images were preferred for the positive agent (78%), and breath-hold T2-weighted images were preferred for the negative agent (93%). Contrast artifacts were more frequently seen with the negative agent (11% and 93%, respectively; p = .0001), and such artifacts were eliminated using T2-weighted sequences. CONCLUSION: Both contrast agents were effective in pelvic MR imaging, but delineation of normal and pathologic structures was better with the negative agent. Gradient-recalled echo T1-weighted sequences are recommended for positive contrast agents, and breath-hold T2-weighted sequences are recommended for negative contrast agents.

Transbrachial arteriography: indications and complications.

PURPOSE: to retrospectively evaluate brachial artery puncture at the antecubital fossa with regard to the indications for and complications arising from the procedure. PATIENTS AND METHODS: Sixty-two cumulative brachial artery punctures in fifty-three patients over a 5-year-period were retrospectively studies. RESULTS: In the majority of cases the brachial approach was utilised in order to avoid groin puncture in patients with absent femoral pulses or recent graft surgery. Occasionally it was performed as a more direct method of assessing upper limb arterial anatomy. Catheter sizes ranged from 3F to 8F. Fifty-one (82%) of the procedures were diagnostic and 11 (18%) were interventional. Glyceryl trinitrate was routinely administered. The overall incidence of complications was low (8%) and included haematoma and arterial spasm. None required surgical intervention and all resolved without permanent sequelae. CONCLUSION: Brachial artery puncture at the antecubital fossa is a suitable site of access for both diagnostic and interventional procedures. Potential limitations are the long distance from puncture site to that of intervention and damage to the brachial artery can result in upper limb ischaemia. Percutaneous brachial artery puncture at the antecubital fossa is, however, a low-risk alternative to either intravenous digital subtraction angiography or axillary artery puncture in patients in whom the femoral approach is contraindicated.

Evaluation of the pullback atherectomy catheter in the treatment of lower limb vascular disease.

PURPOSE: To evaluate prospectively the Pullback Atherectomy Catheter (PAC) in terms of its technical success and 1-year patency in the treatment of lower limb vascular disease.M ETHODS: Thirty-nine PAC procedures were performed in 34 patients to treat atherosclerotic disease (occlusive in 51%) of the femoropopliteal arteries, including four cases of graft neointimal hyperplasia and three dissection flaps. Follow-up was by ankle-brachial indices at 24 hr and 1 month, and arteriography at 6 and 12 months. RESULTS: Technical success was achieved in 38 of 39 procedures (97.4%). There was a reduction in mean stenosis from 89.4% to 12.1%, but 69.2% of procedures required additional balloon dilatation to achieve an adequate arterial lumen. Complications followed 15.4% of procedures, a third of which required surgery. CONCLUSION: The PAC is an easy and relatively safe catheter to use, but does not provide a satisfactory arterial lumen without additional percutaneous transluminal angioplasty (PTA). It proved to be effective, however, in the treatment of graft neointimal hyperplasia and in the resection of obstructive intimal flaps following PTA.

A comprehensive analysis of craniofacial trauma.

A review of the literature identified a need for a prospective study of the complete range of craniofacial trauma. The aims of this study were to determine the incidence, etiology, and mechanisms of craniofacial and associated injuries, enabling a greater understanding of their range and magnitude. Nine hundred fifty consecutive patients seen at an urban university hospital with any degree of craniofacial trauma were prospectively investigated. Craniofacial trauma was found to be very common at all ages. The causes were directly related to age, sex, and alcohol consumption, and determine the type and severity of injury. The commonest cause of soft-tissue injury was falls, whereas that of fractures was interpersonal violence. Falls accounted for most of the injuries in children and the elderly, whereas interpersonal violence was mainly responsible for those occurring in patients aged 15 to 50 years. Interpersonal violence mostly involved young male adults: fights occurring mainly between strangers who had consumed excessive amounts of alcohol. Women were usually assaulted by assailants known to them, their partners. Pedestrians showed a propensity to sustain cranial fractures, whereas motor vehicle occupants tended to sustain midfacial fractures and bicyclists mandibular fractures. Pedestrians incurred the severest injuries of all road users, and a significant proportion of road user collisions involved bicyclists. Sports were responsible for a significant proportion of craniofacial injuries in youths and young adults. Craniofacial soft-tissue injuries overall occurred most frequently on the forehead, nose, lips, and chin, and a method for their classification is proposed. The commonest craniofacial fracture was that of the nasal bones (45%), followed by cranial bones (24%), mandible (13%), zygoma (13%), orbital blow-out (3%), and maxilla (2%). The incidence of craniofacial trauma can be greatly reduced by improvements in interior home design, school education in alcohol abuse and handling potentially hostile situations (especially for men), improvement in automotive safety devices and compliance by motor vehicle occupants, and utilization of full-face helmets by bicyclists and motorcyclists.

HRCT diagnosis of diffuse parenchymal lung disease: inter-observer variation.

BACKGROUND: This study was designed to measure inter-observer variation between thoracic radiologists in the diagnosis of diffuse parenchymal lung disease (DPLD) using high resolution computed tomography (HRCT) and to identify areas of difficulty where expertise, in the form of national panels, would be of particular value. METHODS: HRCT images of 131 patients with DPLD (from a tertiary referral hospital (n = 66) and regional teaching centres (n = 65)) were reviewed by 11 thoracic radiologists. Inter-observer variation for the first choice diagnosis was quantified using the unadjusted kappa coefficient of agreement. Observers stated differential diagnoses and assigned a percentage likelihood to each. A weighted kappa was calculated for the likelihood of each of the six most frequently diagnosed disease entities. RESULTS: Observer agreement on the first choice diagnosis was moderate for the entire cohort (kappa = 0.48) and was higher for cases from regional centres (kappa = 0.60) than for cases from the tertiary referral centre (kappa = 0.34). 62% of cases from regional teaching centres were diagnosed with high confidence and good observer agreement (kappa = 0.77). Non-specific interstitial pneumonia (NSIP) was in the differential diagnosis in most disagreements (55%). Weighted kappa values quantifying the likelihood of specific diseases were moderate to good (mean 0.57, range 0.49-0.70). CONCLUSION: There is good agreement between thoracic radiologists for the HRCT diagnosis of DPLD encountered in regional teaching centres. However, cases diagnosed with low confidence, particularly where NSIP is considered as a differential diagnosis, may benefit from the expertise of a reference panel.