John Murchison | University of Edinburgh (original) (raw)

Papers by John Murchison

British Journal of Radiology, 2010

The aim of this study was to determine whether there is superior diagnostic accuracy for the dete... more The aim of this study was to determine whether there is superior diagnostic accuracy for the detection and exclusion of bronchiectasis using 16-slice CT of the chest (1 mm) compared with conventional high-resolution CT (HRCT) of the chest (10 mm). A prospective study was carried out in patients who were referred for chest CT by a chest physician for the investigation of bronchiectasis over a 1-year period. All scans were performed using a 16-slice CT scanner. In addition to contiguous 1 mm slices, conventional HRCT images (1 mm slice every 10 mm) were prepared. Both datasets were dual read. There were 53 patients with a median age of 62 years (range, 51.5-71.5 years), comprising 14 males and 39 females. 10 of 53 scans had no bronchiectasis in either dataset. 36 patients had bronchiectasis diagnosed on both HRCT and 1 mm scans. Two patients had tubular bronchiectasis on the HRCT scans, which was not confirmed on the 1 mm scans. Five patients had confirmed tubular bronchiectasis on the 1 mm scans, which was not identified on HRCT scans. 40 extra lobes demonstrated bronchiectasis on the 1 mm vs the HRCT scans; of these, half were labelled as definite bronchiectasis on the 1 mm scan. There was a 32% increased confidence with the 1 mm scans compared with conventional HRCT of the chest in the diagnosis of bronchiectasis (p , 0.001). In conclusion, there is improved diagnostic accuracy and confidence for diagnosis and exclusion of bronchiectasis using 16-slice chest CT (1 mm cuts) compared with conventional HRCT of the chest.

QJM: An International Journal of Medicine, Sep 11, 2016

Scientific Reports, Sep 6, 2018

Poster: "ECR 2011 / C-0614 / The importance of scrutinising extraneous lines on chest radiog... more Poster: "ECR 2011 / C-0614 / The importance of scrutinising extraneous lines on chest radiographs." by: "E. J. R. Van Beek1, A. T. Laroia2, J. Reid3, J. T. Murchison1, B. T. Thompson2; 1Edinburgh/UK, 2Iowa City, IA/US, 3Melrose, Roxburghshire/UK"

The Journal of Pathology, Sep 1, 2013

Programmed Learning and Educational Technology, 1978

ABSTRACT This paper begins with a description of recent work concerned with the development of in... more ABSTRACT This paper begins with a description of recent work concerned with the development of intelligent teaching programs. For ease of discussion, those projects with firm roots in artificial intelligence are dealt with first. We will see that the AI research worker has tended to take a rather global approach to constructing intelligent systems since he is very much concerned with the difficulties (or advantages) that occur when different kinds of knowledge interact in a program. Next, we consider a growing number of programs which have their roots in CAI, but embrace AI techniques to handle particular problems. In this area developments are largely taking place in a step‐by‐step fashion in response to practical needs. In contrast to the work on building teaching programs, recent research into constructing learning environments is dealt with in the following section. Here there is a close meshing between the AI‐inspired work and cognitive learning theory. The paper closes with speculative remarks about developments likely to take place in the next decade or so.

PLOS ONE, May 5, 2022

In this study, we evaluated a commercially available computer assisted diagnosis system (CAD). Th... more In this study, we evaluated a commercially available computer assisted diagnosis system (CAD). The deep learning algorithm of the CAD was trained with a lung cancer screening cohort and developed for detection, classification, quantification, and growth of actionable pulmonary nodules on chest CT scans. Here, we evaluated the CAD in a retrospective cohort of a routine clinical population. Materials and methods In total, a number of 337 scans of 314 different subjects with reported nodules of 3-30 mm in size were included into the evaluation. Two independent thoracic radiologists alternately reviewed scans with or without CAD assistance to detect, classify, segment, and register pulmonary nodules. A third, more experienced, radiologist served as an adjudicator. In addition, the cohort was analyzed by the CAD alone. The study cohort was divided into five different groups: 1) 178 CT studies without reported pulmonary nodules, 2) 95 studies with 1-10 pulmonary nodules, 23 studies from the same patients with 3) baseline and 4) followup studies, and 5) 18 CT studies with subsolid nodules. A reference standard for nodules was based on majority consensus with the third thoracic radiologist as required. Sensitivity, false positive (FP) rate and Dice inter-reader coefficient were calculated. Results After analysis of 470 pulmonary nodules, the sensitivity readings for radiologists without CAD and radiologist with CAD, were 71.9% (95% CI: 66.0%, 77.0%) and 80.3% (95% CI: 75.2%, 85.0%) (p < 0.01), with average FP rate of 0.11 and 0.16 per CT scan, respectively. Accuracy and kappa of CAD for classifying solid vs sub-solid nodules was 94.2% and 0.77, respectively. Average inter-reader Dice coefficient for nodule segmentation was 0.83 (95% CI: 0.39, 0.96) and 0.86 (95% CI: 0.51, 0.95) for CAD versus readers. Mean growth

BMJ, Jan 6, 2016

A 27 year old woman presented with acute abdominal pain after a brief syncope while on a fairgrou... more A 27 year old woman presented with acute abdominal pain after a brief syncope while on a fairground ride. She reported no history of …

Scottish Medical Journal, Feb 1, 2009

Journal of Thoracic Imaging, Sep 2, 2020

PURPOSE Coronary artery calcification (CAC) on thoracic computed tomography (CT) can identify pat... more PURPOSE Coronary artery calcification (CAC) on thoracic computed tomography (CT) can identify patients at risk of coronary artery disease (CAD) mortality. However, the overlap between bronchiectasis and CAC severity for predicting subsequent outcomes is unknown. MATERIALS AND METHODS CT images from 362 patients (mean age 66±14 y, 38% male) with known bronchiectasis were assessed. Bronchiectasis severity was assessed using the Bronchiectasis Severity Index (0 to 4, mild; 5 to 8, moderate; and ≥9, severe). CAC was assessed with a visual ordinal score (0, none; 1, mild; 2, moderate; 3, severe) in each of the left main stem, left anterior descending, left circumflex, and right coronary arteries. Vessel CAC scores were summed and categorized as none (0), mild (1 to 3), moderate (4 to 8), and severe (9 to 12). RESULTS Patients with severe bronchiectasis were older (P<0.001), but were not more likely to have a history of CAD, hypertension, or smoking. CAC was present in 196 (54%). Over a mean of 6±2 years, 59 (16%) patients died. Patients with moderate or severe CAC were 5 times more likely to die than patients without CAC (hazard ratio: 5.49, 95% confidence interval: 2.82-10.70, P<0.001). Patients with severe bronchiectasis were 10 times more likely to die than patients with mild bronchiectasis (hazard ratio: 10.11, 95% confidence interval: 4.22-24.27, P<0.001). CAC and bronchiectasis severity were independent predictors of mortality, but age, sex, smoking, and history of CAD or cerebrovascular disease were not. CONCLUSIONS CAC is common in patients with bronchiectasis, and both CAC and bronchiectasis severity are independent predictors of mortality.

The European respiratory journal, Mar 1, 2005

Accurate staging of the mediastinum in lung cancer is essential for optimising treatment strategi... more Accurate staging of the mediastinum in lung cancer is essential for optimising treatment strategies. Conventional transbronchial needle aspiration (TBNA) is a blind procedure, reliant upon prior computed tomography (CT) or ultrasound imaging, but has low sensitivity. The current study reports the initial experience of using a prototype endobronchial ultrasound (EBUS) probe that allows TBNA under real-time imaging. In 20 patients

Journal of the Royal College of Physicians of Edinburgh, 2020

Background Outcome data are limited for upper extremity deep venous thrombosis (UEDVT). The outco... more Background Outcome data are limited for upper extremity deep venous thrombosis (UEDVT). The outcomes of patients investigated for, but without UEDVT remain uncertain. Methods Retrospective analysis of clinical records of adult patients undergoing Doppler ultrasound for potential UEDVT between 1 January 2007 and 31 December 2014 was undertaken. Primary outcome was all-cause mortality. Secondary outcomes were new cancer diagnosis and thromboembolic recurrence. Results The final cohort (n = 528) comprised 25 primary UEDVT, 100 secondary UEDVT, 40 superficial-venous thrombosis and 363 without thrombus patients. There were 207 deaths. Survival was higher in primary than in secondary UEDVT (log-rank p < 0.0001) or those without thrombus (log-rank p = 0.001). Pre-existing cancer [hazard ratio 3.6 (95% confidence interval 1.5-8.9)] was the biggest independent predictor of mortality and leading cause of death. Developing UEDVT was a poor prognostic marker in cancer patients. Conclusion Th...

Poster: "ECR 2019 / C-3685 / Evaluation of deep learning software tool for CT based lung nod... more Poster: "ECR 2019 / C-3685 / Evaluation of deep learning software tool for CT based lung nodule growth assessment " by: "J. Murchison, G. Ritchie, D. Senyszak, E. J. R. Van Beek ; Edinburgh/UK"

Purpose: To assess the change in practice and resulting diagnostic outcome in the radiological in... more Purpose: To assess the change in practice and resulting diagnostic outcome in the radiological investigation of pulmonary embolism since the introduction of helical CTPA in a large teaching hospital. Methods and Materials: A retrospective review was undertaken of all radiological investigations performed over a 6-year period before and after the introduction of CTPA (protocols 1 and 2, respectively) as an integral part of the imaging protocol in the investigation of clinically suspected PE. The total numbers and results of all investigations are assessed for each protocol. Results: A substantive increase in both the total number of patients and the number of investigations performed for the investigation of PE since the introduction of CTPA occurred. Five hundred and twenty-six patients underwent 617 investigations performed in 1995/1996 with 760 patients undergoing 805 in 2001/2002. There was a significant decrease in the number of investigations per patient, 1.17 in 1995/1996 versus 1.06 in 2001/2002. Primary investigation showed a significant decrease in indeterminate examinations from 25.7% to 8.5% and an increase in positive results for pulmonary embolism from 18% to 24%. Conclusion: In the study population there was a significant increase in the number of patients being investigated for PE, with a decrease in both the number of non-diagnostic investigations and the total investigations per patient since the introduction of helical CTPA. This is probably due to the ready availability of a new imaging technique and Insights into VTE John T Murchison 15 physicians awareness, that CTPA has significantly improved specificity, which encourages the referral of patients for investigation.

Clinical Radiology, 2017

It is crucial to identify idiopathic pulmonary fibrosis (IPF) patients at risk of progressive dis... more It is crucial to identify idiopathic pulmonary fibrosis (IPF) patients at risk of progressive disease, early in their disease course. We evaluated IPF patients, using functional, visual and computer-derived (CALIPER) computed tomography (CT) scores to identify predictors of a 10% forced vital capacity (FVC) decline at one year. Methods and materials: 159 IPF patients had baseline FVC, DLco and composite physiologic index (CPI), gender/age/ pulmonary physiological parameters (GAP) index and the following visual and CALIPER CT indices evaluated: Visual and CALIPER interstitial lung disease (ILD) and fibrosis extent, honeycombing, reticulation, ground glass and emphysema scores. Traction bronchiectasis extent and severity were examined visually. CALIPER pulmonary vessel volume (PVV) was examined as a percentage of the whole lung, and as percentages of the upper, middle and lower zones. PVV vessel sizes: <5 mm 2 , 5e10 mm 2 , 10e15 mm 2 , 15e20 mm 2 , >20 mm 2 were also examined on a zonal basis. The slope of annual FVC change (in ml) per subject was estimated using linear regression. Variables were tested using logistic regression to predict estimated 10% FVC decline at year one. All models were adjusted for patient age, gender, smoking history and pack year status. Results: Across all patients, CALIPER vessel scores and fibrosis extent were the strongest predictors of a 10% FVC decline. Following division into three equal-sized disease severity groups (n¼53) based on DLco values, variables predicting a 10% FVC decline were examined in patients with mild+moderate disease (DLco >35.8%; n¼106), and separately in patients with mild disease (DLco>46.5%; n¼53). CALIPER vessel scores and fibrosis extent remained the strongest predictors of a 10% FVC decline in both groups. Conclusion: Quantitative CT imaging, particularly PVV outperforms functional indices and the GAP index at predicting 10% FVC decline at one year and may represent a powerful new index for cohort enrichment in IPF drug trials.

European Journal of Radiology, 2013

We read with interest the article by Szekely et al. [1] highlighting he range and benefits of rad... more We read with interest the article by Szekely et al. [1] highlighting he range and benefits of radiology related smartphone and tablet pplications. However several issues warrant further attention. First, only a small number of relevant applications were idenified by the authors. Their search revealed 81 radiology related pplications, however, during a recent review of radiology applicaions available on smartphones in June 2012, we identified several undred relevant English language applications [7]. The date of the uthors’ search is not included in the paper and their exclusion riteria may have differed from our own, precluding direct comarison of the data sets. However we are concerned the authors’ earch was incomplete. For example notable applications such as ujifilm Synapse Mobility image viewing application and the Royal ollege of Radiologists of the UK’s iRefer application are not listed n the paper. Given the limitations of smartphone and tablet displays, image iewing applications are more suitable for secondary image review n clinical environments rather than primary diagnosis in the radilogy department. The use of such devices in clinical areas also arriers the risk of bacterial cross contamination. The potential f mobile communication devices to act as reservoirs for bacteia able to cause nosocomial infections is well established [2,3]. he potential use of smartphones and tablets in the patient’s nvironment makes the infection control concerns more pressng. Sterile sleeves for tablet devices are available and used in perating theatres to eliminate the risk of bacterial contaminaion [4]. However their routine use in the ward environment is less ractical. The potential benefits of education and decision support appliations are well highlighted within the paper. However studies n other medical specialities have identified low levels of adverised medical input in medical application design, with subsequent oncerns over the reliability of application output [5,6]. The ack of regulation of medical applications, including radiologyelated applications, means the accuracy of application content is nknown. We believe radiology related applications have many benefits, ith the potential to improve medical training and patient care.

Critical Care Medicine, 1999

CRC Press eBooks, Mar 2, 2022