Image processing and analysis in drug discovery and clinical trials

DEVELOPMENT of new and more effective drugs is an imperative of modern healthcare. The growing elderly population and an increasing number of chronic diseases represent a major challenge to our healthcare systems. In addition to providing new hope for terminally ill patients, bringing new drugs to market has important economic consequences. Drug discovery helped to cut deaths from heart disease and stroke by 50% over the past 30 years. There are over 400 new medicines in different stages of development just for cancer alone. Spending $1 for prescription drugs avoids spending almost $4 on hospital costs. Medical imaging and image analysis are employed in many stages of the complex processes leading to clinical availability of a new drug. This special issue is contributing to the drug-development endeavors by offering a multifaceted view of current efforts in this rapidly developing field. Drug discovery and development are challenging disciplines attempting to understand the fundamental properties of life itself through studies of disease. This understanding is brought to practical use through identification of new targets and generation of new compounds. Recently, however, it has become apparent that the pharmaceutical and biotechnology industries are facing fundamental structural problems. According to statistics published by the Pharmaceutical Research and Manufacturers of America Foundation (PhRMA), spending in research and development (R&D) has increased exponentially and in 1999 reached a level of $30 billion in the United States alone. This steep increase in R&D spending has not resulted in a similar increase of successful drugs addressing those debilitating and costly chronic diseases affecting the world’s ageing population. While the genomic revolution has generated an enormous potential, whereby the sequencing of the human genome has expanded the number of potential targets, the promise yet needs to materialize. New technologies such as combinatorial chemistry have enhanced the ability to create large numbers of potentially active compounds with little being known about the validity of the new targets. Confronted with hundreds of thousands of potentially active compounds that must be screened and tested, possible failures are pushed further into the development pipeline with enormous derived losses as one consequence. At the same time the number of costly clinical trials required for each new drug application is on a rising trend, in an ever more regulated environment. One answer to such problems is the introduction of novel technologies into the pharmaceutical research that increase knowledge about how potential new drugs modify the disease in living organizms. In response to this demand, new and powerful anatomical and functional imaging devices are emerging to offer new possibilities to scientists in preclinical and clinical