Authors' objectives:

The aim of this report was to summarize the evidence from systematic reviews (SRs) reporting on the clinical effectiveness of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) in the investigation of specific clinical conditions of the chest and the cardiovascular, neurological, and urological systems.

Authors' results and conclusions: From the electronic database search, 31 of 947 articles were selected for inclusion, with 17 (of 145) added after review of the grey literature. The 48 articles reported on 49 SRs covering 11 clinical conditions, ranging from one SR for headaches to 12 SRs for pulmonary embolism. Based on studies of diagnostic accuracy, the evidence was promising for five conditions: carotid artery disease, peripheral vascular disease, pulmonary embolism, renal artery stenosis and stroke. Authors were more cautious about three conditions: cerebral aneurysms, coronary artery disease and lung cancer screening. Evidence was sparse for three conditions: headaches, head injuries and seizures. No SR evidence was identified for the remaining two conditions: cerebral AVMs and screening for urolithiasis. Quality scores for the SRs were generally low. Using the Oxman and Guyatt scale, 72% (40/49) of SRs were deemed to have substantial flaws, the remainder having minor to minimal flaws. Using the Fryback and Thornbury efficacy grading scale, 86% of SRs were deemed to be Level 2 studies (of six levels), assessing diagnostic accuracy, sensitivity and specificity, rather than impact on patient management or outcomes.

Authors' recommendations: In this project we aimed to summarize the SR evidence reporting on CT and MRI for the investigation of 13 specific medical conditions where controversy around the use of the technologies exists. Analysis of the information obtained led to a spectrum of support for CT and MRI, from promising, to cautious, to non-existent. Most studies suggested more research would be welcome to explore the benefits of the technologies as compared with the investigations that have traditionally been used. For CT and MRI, technology has advanced rapidly and the devices that were used to conduct the primary studies in the SRs analyzed for this report have often been upgraded or replaced. For this reason, practitioners in the field could argue that the findings of this report may not be contemporary enough to be useful for clinicians and decision makers ; the ability of the report's findings to guide decisions may be seen as limited. The case can be made that diagnostic imaging technologies may improve or expedite the identification of a disease process but cannot, a priori, change its outcome. Because an imaging investigation occurs early in the clinical timeline of the work-up of a patient's clinical disorder, it may be difficult for imaging findings to affect patient management and outcomes. However, to ensure the most effective use of the technologies, measurement of their influence on patient management and outcomes must be a goal.

Authors' methods: Systematic review

Project Status: Completed

URL for project: https://www.ccohta.ca/

Year Published: 2005

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Canada

Organisation Name: Canadian Coordinating Office for Health Technology Assessment

Contact Address: 600-865 Carling Avenue, Ottawa, ON K1S 5S8 Canada. Tel: +1 613 226 2553, Fax: +1 613 226 5392;

Contact Name: requests@cadth.ca

Contact Email: requests@cadth.ca

Copyright: Canadian Coordinating Office for Health Technology Assessment (CCOHTA)