Recent public opinion polls, the 2003 First Ministers' Accord on Health Renewal, regional and hospital plans and election campaign platforms confirm that timely access to diagnostic services is a major priority across the country. Underlying the access challenge is a tangle of questions about the right number and mix of imaging machines; the types of services provided; how imaging influences patients' care and outcomes; how long patients wait for tests, results and follow-up care; and who provides imaging services. Until now, we have had little systematic knowledge of the imaging landscape in Canada. An overview of recent trends and emerging issues is essential to sound decision-making at all levels.