Choices in medicine: illustrations from imaging

Progress in medicine is almost always led by advances in science and technology. During the last quarter of a century, startling developments have taken place in medical imaging. X-ray techniques have been extended by improvements in film-screen technology and image intensifiers; digital radiography and computed tomography have been introduced. The gamma camera has been combined with computer processing and new radiopharmaceuticals have been devised. The resolution of real-time two-dimensional ultrasonic scanning has been improved almost to the diffraction limit and Doppler techniques provide detailed information about blood flow. Magnetic resonance imaging yields exquisite anatomical detail, tissue characterization and flow data and biochemistry can be studied through spectroscopy. Research aimed at improving all these methods is actively being pursued and there is interest in the potential of microwave, electrical impedance and light transmission techniques as medical imaging tools. In parallel with these diagnostic advances, techniques for minimally invasive surgery are being developed. Guided by appropriate imaging methods, suitable forms of radiation can be directed through the intact skin, or small instruments can be introduced through natural orifices or tiny incisions. Thus it is possible to undertake many interventional procedures that previously required open surgery. Because resources are limited, choices have to be made taking benefits, risks and costs into account. No diagnostic method is perfect; medical imaging is expensive in terms of equipment and trained personnel and its use has to be justified in competition with demands from other areas of health care. Unproductive work is having to be identified and abandoned.(ABSTRACT TRUNCATED AT 250 WORDS)