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J Cullingworth

Publications and source records attributed to J Cullingworth.

7 recordsLinked to original sources
PubMed2001

A systematic review of the staging performance of endoscopic ultrasound in gastro-oesophageal carcinoma.

BACKGROUND: Endoscopic ultrasound (EUS) may be used for preoperative staging of gastro-oesophageal carcinoma but performance values given in the literature differ. AIMS: To identify and synthesise findings from all articles on the performance of EUS in tumour, node, metastasis (TNM) staging of gastro-oesophageal carcinoma. SOURCE: Published and unpublished English language literature, 1981-1996. METHODS: Data on the staging performance of EUS were retrieved and evaluated. Summary receiver operator characteristic methodology was used for synthesis, and a summary estimate of performance, Q*, obtained. Multiple regression analysis was used to assess study validity and investigate reasons for differences in performance. RESULTS: Twenty seven primary articles were assessed in detail. Thirteen supplied results for staging oesophageal cancer, 13 for gastric cancer, and four for cancers at the gastro-oesophageal junction. For gastric T staging, Q*=0.93 (95% confidence interval (CI) 0.91-0.95) and for oesophageal T staging, Q*=0.89 (95% CI 0.88-0.92). For gastro-oesophageal T staging, including cancers at the gastro-oesophageal junction, Q*=0.91 (95% CI 0.89-0.93). Inclusion of cases with non-traversable stenosis was found to slightly reduce staging performance. For N staging, Q*=0.79 (95% CI 0.75-0.83). In articles that compared EUS directly with incremental computed tomography, EUS performed better. None of the variables assessed in the regression analysis was significant using a Bonferroni correction. Three variables (anatomical location, traversability, and blinding) showed strong relationships for future research and validation. CONCLUSIONS: EUS is highly effective for discrimination of stages T1 and T2 from stages T3 and T4 for primary gastro-oesophageal carcinomas. The failure rate of EUS from non-traversability of a stenotic cancer may be a limitation in some patient groups.

Confidence Intervals↗
PubMed1997

The identification of bias in studies of the diagnostic performance of imaging modalities.

The demand for evidence-based healthcare is increasing nationally and internationally and it is equally necessary in both diagnostic and therapeutic practice. Evidence may be collected and combined by means of a systematic literature review of published and unpublished data on a well-defined topic. The output of such reviews is then available to guide health policy, influence good practice or direct research. Published guidelines are available on the performance of systematic reviews, especially those of randomized controlled trials. Although there is an extensive literature base of research data in diagnostic imaging there are few such trials, but it is still possible to perform systematic reviews. With the alternative study designs encountered it is important to be aware of the main threats to study validity. In this paper the biases likely to be encountered in studies of diagnostic performance are reviewed, with particular reference to diagnostic imaging tests. The biases are sub-divided into three categories. The first category is patient selection and covers the validity of generalizing results beyond the study population. The other two, concerning study design and execution and the interpretation of results, affect the likely validity of the results of a study. An understanding of these factors is an essential prerequisite for those undertaking or using a systematic literature review in the field of diagnostic imaging. The definitions form the foundations of a defensible review protocol.

Bias↗
PubMed1993

Fast magnetic resonance angiography using turbo-FLASH sequences in advanced aortoiliac disease.

A prospective study using contrast enhanced turbo-FLASH (Fast Low-Angle Shot) magnetic resonance (MR) angiography was performed to assess the arterial anatomy in patients who had advanced atherosclerotic aortoiliac disease. This new imaging sequence was employed in 17 patients and the results were compared with conventional abdominal aortography. MR angiography accurately detected all aortic occlusions (3/3), their sites and their extent. All nine iliac occlusions were correctly identified (sensitivity 100%, specificity of 90%). The sensitivity was 100% for stenosis of 50% or greater in the abdominal aorta, and the iliac and common femoral arteries. The degree of stenosis was overgraded in 20 of 51 lesions (39.2%). Mild stenosis was overgraded as moderate stenosis in 10 and as severe stenosis in three. Moderate stenosis was overgraded as severe stenosis in four. None of the mild or moderate stenoses resulted in areas of signal voids suggestive of occlusions. Three severe stenoses were seen as areas of signal voids (two iliac, one femoral). In the eight patients who had in total 10 aneurysmal dilatations of the aorta or the iliac arteries, MR angiography was superior in demonstrating the true extent of the aneurysms. We conclude that turbo-FLASH MR angiography has the potential to be a useful non-invasive imaging technique for patients with advanced aortoiliac disease.

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