229 research outputs found
False negative results in lung cancer screening - Evidence and Controversies
No full textIdentifying false negative cases is an important quality metric in lung cancer screening but these have been infrequently and variably reported in previous studies. Although as a proportion of all screening participants, false negative cases are uncommon, such cases may constitute a significant proportion of all lung cancers diagnosed (up to 15%) within a screening programme. This article reviews the impact and causes of false negative lung cancer screening tests, including those related to radiological evaluation, nodule management protocols, and management decisions made by multidisciplinary teams. Following a review of data from international screening studies, this article discusses controversies within the screening literature surrounding the definition and classification of a false negative lung cancer screening test, and how data on false negative rates should be captured and recorded. Challenges, such as avoiding overly cautious surveillance of lung nodules whilst also minimizing over-diagnosis and investigation of indolent or benign lesions, are considered. Finally, the advantages and disadvantages of different approaches to dealing with false negative results in lung cancer screening are discussed
Information Technology Impacts on Firm Performance: An Extension of Kohli and Devaraj (2003)
No full textDespite the importance of investing in information technology, research on business value of information technology (BVIT) shows contradictory results, raising questions about the reasons for divergence. Kohli and Devaraj (2003) provided valuable insights into this issue based on a meta-analysis of 66 BVIT studies. This paper extends Kohli and Devaraj by examining the influences on BVIT through a meta-analysis of 303 studies published between 1990 and 2013. We found that BVIT increases when the study does not consider IT investment, does not use profitability measure of value, and employs primary data sources, fewer IT-related antecedents, and larger sample size. Considerations of IT alignment, IT adoption and use, and interorganizational IT strengthen the relationship between IT investment on BVIT, whereas the focus on environmental theories dampens the same relationship. However, the use of productivity measures of value, the number of dependent variables, the economic region, the consideration of IT assets and IT infrastructure or capability, and the consideration of IT sophistication do not affect BVIT. Finally, BVIT increases over time with IT progress. Implications for future research and practice are discussed
Method for minimizing observer variation for the quantitation of high-resolution computed tomographic signs of lung disease.
No full textOBJECTIVES: This study aimed to describe a method of reducing interobserver variation associated with the visual quantitation of high-resolution computed tomographic (HRCT) signs of airways and interstitial lung disease (ILD).
METHODS: The HRCT scans of 2 cohorts of patients with airways disease (n = 144) and ILD (n = 109) were evaluated by 2 observers. Selected signs of airways disease were evaluated: (1) bronchial wall thickness and (2) the extent of the decreased attenuation. In the ILD group, the total extent of disease was scored. These 3 HRCT signs were scored by 2 observers independently using a standard method. The observers rescored the CT scans with a new scoring system (continuous learning method, CLM).
RESULTS: Observer agreement for CT signs was superior for CLM: bronchial wall thickness κw increased from 0.51 to 0.76; for decreased attenuation, κw increased from 0.34 to 0.81; and for ILD extent, κw increased from 0.53 to 0.87.
CONCLUSIONS: The CLM reduces noise from observer variation in studies that require visual quantitation of HRCT signs of lung disease
Chronic hypersensitivity pneumonitis: high resolution computed tomography patterns and pulmonary function indices as prognostic determinants.
No full textOBJECTIVES: To investigate high resolution computed tomography (HRCT) and pulmonary function indices (PFTs) for determining prognosis in patients with chronic fibrotic hypersensitivity pneumonitis (CHP).
METHODS: Case records, PFTs (FEV(1), FVC and DLco) and HRCTs of ninety-two patients with chronic hypersensitivity pneumonitis were evaluated. HRCT studies were scored by two observers for total disease extent, ground-glass opacification, fine and coarse reticulation, microcystic and macrocystic honeycombing, centrilobular emphysema and consolidation. Traction bronchiectasis within each pattern was graded. Using Cox proportional hazards regression models the prognostic strength of individual HRCT patterns and pulmonary function test variables were determined.
RESULTS: There were forty two deaths during the study period. Increasing severity of traction bronchiectasis was the strongest predictor of mortality (HR 1.10, P < 0.001, 95%CI 1.04-1.16). Increasing global interstitial disease extent (HR 1.02, P = 0.02, 95%CI 1.00-1.03), microcystic honeycombing (HR 1.09, P = 0.019, 95%CI 1.01-1.17) and macrocystic honeycombing (HR 1.06, P < 0.01, 95%CI 1.01-1.10) were also independent predictors of mortality. In contrast, no individual PFT variable was predictive of mortality once HRCT patterns were accounted for.
CONCLUSION: HRCT patterns, in particular, severity of traction bronchiectasis and extent of honeycombing are superior to pulmonary function tests for predicting mortality in patients with CHP.
KEY POINTS: • HRCT is increasingly used to assess chronic fibrotic hypersensitivity pneumonitis. • HRCT patterns are superior to pulmonary function tests for predicting mortality. • Extensive traction bronchiectasis strongly predicts poor survival in chronic hypersensitivity pneumonitis
Connective tissue disease related fibrotic lung disease: high resolution computed tomographic and pulmonary function indices as prognostic determinants.
No full textTo determine high resolution computed tomography (HRCT) patterns and pulmonary function indices which are associated with increased mortality in patients with connective tissue disease related fibrotic lung disease (CTD-FLD).HRCTs from 168 patients with CTD-FLD were scored by 2 observers for a variety of HRCT patterns and traction bronchiectasis. A radiological diagnosis of usual interstitial pneumonia (UIP), fibrotic non-specific interstitial pneumonia (NSIP) or indeterminate was also assigned. Using Cox regression analysis, associations with mortality were identified. Honeycombing and traction bronchiectasis scores were converted to binary absence/presence scores and also tested. A subgroup analysis of patients with biopsy material (n=51) was performed by classifying patients according to radiological and histopathological diagnoses, as concordant UIP, discordant UIP and fibrotic NSIP. The prognostic separation of this classification was also evaluated.Severity of traction bronchiectasis (HR 1.10, p=0.001, 95\% CIs 1.04 to 1.17), increasing extent of honeycombing (HR 1.08, p=0.021, 95\% CI 1.03 to 1.13) and reduction in DLco (HR 0.97, p=0.013, 95\% CI 0.95 to 0.99) were independently associated with increased mortality. Interobserver agreement and prognostic strength were higher for binary traction bronchiectasis scores (weighted κ (κw)=0.69, HR 4.00, p=0.001, 95\%CI 1.19 to 13.38), than binary honeycombing scores (κw=0.50, HR 2.87, p=0.022, 95\% CI 1.53 to 5.43). The radiological-histopathological classification was strongly associated with increased mortality (HR 2.74, p<0.001, 95\% CI 1.57 to 4.77) and patients with discordant UIP had a better prognosis than concordant UIP but worse prognosis than fibrotic NSIP.Severity of traction bronchiectasis, extent of honeycombing and DLco are strongly associated with mortality in CTD-FLD. Interobserver agreement for traction bronchiectasis is higher than for honeycombing. In CTD-FLD, radiological diagnosis has survival implications in biopsy proven UIP
Evaluation of computed tomography (CT) features of lung volume alteration in diffuse lung disease
No full textBackground
Lung volume change in idiopathic pulmonary fibrosis (IPF) or chronic obstructive pulmonary disease (COPD) may impact upon fissures and diaphragm. CT measures designed to capture displacement of these structures may play a role in prognostication.
Methods
The cohorts studied were: baseline IPF with 273 patients (205 males, median age 67), serial IPF with 81 patients (66 males, median age 67) and baseline COPD with 150 patients (76 males, median age 64). Selected HRCT signs included oblique fissure retraction distance (OFRD), anterior junctional distance (AJD), sagittal lung height (SLH) and superior mediastinal level (SML). The disease extent on HRCT in IPF was scored by two observers. In COPD cohort, an automated application (Syngovia) was used for disease quantification. The CT measurements were validated against PFTs and mortality using linear regression and proportional hazards analyses.
Results
There were 203 baseline and 58 serial deaths in IPF cohorts with median survival 26 and 17 months respectively. In baseline IPF and COPD, SLH was the strongest determinant of TLC% and RV/TLC% respectively (R2 =0.28, P<0.005 and R2 =0.1 respectively, P<0.0005). In baseline IPF data, a combination of SLH, AJD and OFRD improved correlation with TLC% (R2=0.42, P<0.0005), predicting mortality independent of visual scores (HR=97, CI 0.96,0.99, P<0.0005). In serial IPF, annual AJD change predicted mortality (HR 0.97, 95% CI 0.95, 0.98; P<0.0005) better than annual FVC change (HR 0.98, 95% CI 0.96, 0.99; p<0.0005). In COPD, there was significant difference in patients with or without upper-zone predominant disease for OFRD and SML (P=0.04 and P<0.0005 respectively).
Conclusion
The CT signs of lung volume change correlate moderately with PFTs in COPD and IPF; being independent predictors of mortality when adjusted for visual scores in IPF and providing signal on zonal distribution of disease in COPD. In IPF, AJD proved to be a better predictor of outcome compared to FVC sequentially.Open Acces
CT findings in fibrotic lung disease: reassessment of the reliability and utility of the status quo in diagnosis and outcome
No full textHypersensitivity pneumonitis is a pulmonary disease thought to result from an inappropriate immune response to inhaled organic antigens. Whilst historically classified by the duration of symptoms, a categorisation based on the presence of pulmonary fibrosis is now favoured, as this is related to disease course and response to treatment. Furthermore, the presence of fibrosis invokes a different radiological differential diagnosis.
In addition to this paradigm shift, several short comings of the literature in fibrotic lung disease require scrutiny. CT guidelines use the presence of ‘mosaic attenuation’ to distinguish fibrotic hypersensitivity pneumonitis (FHP) from its closest radiological differential, idiopathic pulmonary fibrosis (IPF), but these are unvalidated and indeed untested. The presence of increased proportion of lymphocytes on bronchoalveolar lavage (BAL) is used to support a diagnosis of FHP, but this technique has never been validated with regards to diagnostic utility or prognosis. Finally, the majority of publications examining CT signs of fibrotic lung disease are subject to incorporation bias, whereby the CT data under study is also used to define cases.
A re-examination of the CT signs in three separate cohorts of patients with fibrotic lung diseases is presented. Firstly, undertaking a detailed examination of the various forms of mosaic attenuation, against high confidence diagnoses FHP and IPF agnostic to CT data, in a test and validation cohort. A large prospective cohort of patients undergoing BAL who have a ‘reasonable differential’ for FHP, defined without CT data, is also examined.
An overlooked CT sign of mosaic attenuation, the ‘headcheese’ sign, is found to be highly specific for a diagnosis of FHP, as opposed to IPF, and is validated in an external cohort. BAL lymphocyte proportion is shown to relate to disease extent, and BAL lymphocytosis is found to be prognostic in fibrotic lung disease.Open Acces
Imaging: how to recognise idiopathic pulmonary fibrosis
No full textIt is well known that high-resolution computed tomography (HRCT) is an essential component of the diagnostic pathway in idiopathic pulmonary fibrosis (IPF). Honeycombing, a common feature of IPF seen on HRCT, is crucial for an accurate diagnosis. Unfortunately, identification of honeycombing is not always straightforward, and there is some disagreement regarding its imaging features. It can be difficult to distinguish honeycombing from traction bronchiectasis and emphysema, although several imaging characteristics can be helpful. Recently, there has been an interest in expanding the use of HRCT beyond diagnosis for disease monitoring and prognostication, and several studies have provided valuable contributions in this regard. Traction bronchiectasis and the extent of fibrosis, for example, have been reported to be powerful prognostic predictors for mortality. Finally, considering the difficulties in diagnosis of “possible usual interstitial pneumonia”, clinicians should always be aware that clinical factors must be considered together with HRCT in order to reach an accurate diagnosis and provide appropriate treatment
Implementation of lung cancer screening: lessons from a local lung cancer screening pilot
No full textGrowing evidence from screening trials suggests that computed tomography (CT) screening for lung cancer reduces lung cancer mortality, but lung cancer screening has not yet been approved by the UK national screening committee.
This thesis sought to answer questions about how lung screening might be implemented outside a trial setting. Clinical questions included how to maximise participant uptake and attendance for screening, how risk models used in UK pilots to select participants for screening compare in identifying individuals at high risk of cancer, and the downstream consequences of the detection of incidental findings during screening for primary and secondary care. From a radiological angle, workforce requirements for population-based screening are unknown and questions surround the optimisation of nodule management protocols for screening, and how consistent, high-quality reporting can be achieved.
The West London pilot confirmed that with use of risk-based prediction models, lung cancer can be detected with a prevalence of >2.0%. Whilst screening has been advocated as a means to detect undiagnosed cardiovascular and respiratory disease, data from the West London pilot have demonstrated that despite a potential benefit of the identification of such disease, future work will be required to maximise actual benefits, with few participants referred to primary or secondary care having a subsequent change in management.
A study of radiologist reading times demonstrated that lung screening scans can ordinarily be reported in <5 minutes. Radiologist adherence to nodule management guidelines is, however, crucial. The development of a tabulated algorithm and subsequently a mobile phone application to assist radiologists demonstrated that greater adherence to protocols can be achieved than when following flow chart algorithms. A small interobserver agreement study involving clinicians involved in screening from other UK screening centres indicated the need for amendments to the current nodule management guidelines for several challenging nodule management scenarios.Open Acces
Assessment of pulmonary artery pressure using computed tomography signs in various diseases
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
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