Appropriate technology for diagnostic imaging in small hospitals.

How do you choose equipment for imaging from the bewildering and tempting array of alternatives, particularly when your budget is limited ? The rules for shopping for images are the same as those for shopping in a supermarket: have a clear idea of what you need, and remember that cheapness may be a false economy. Imaging for the non-radiologist in a small hospital means diagnostic x ray equipment or ultrasound or both. Ultrasound is extremely useful for looking at structures within the abdomen, for obstetrics, and for visualising the liver and abdominal and pelvic masses. It may also provide information about the kidney, pancreas, and gall bladder. There are no radiation hazards (so far as is known) and imaging is easy, although recording the image is more difficult and expensive. The main disadvantage is that ultrasound is time consuming for the physician as the work cannot be delegated. X ray equipment has much wider application: in all cases of trauma, in many infections, especially those in the chest, in intestinal obstruction, in the investigation of genitourinary and gall bladder disease, and in obstetric practice. Apart from its wider usefulness, the work may be delegated to paramedical staff and there is a permanent record. The disadvantages are costs (US $25 000 upwards compared with $10 000 upwards for ultrasound) and the hazard of radiation, which may be controlled easily with proper precautions. If you have the alternative, buy x ray equipment only. The use for ultrasound in a small hospital is so limited that money should be saved to purchase an x ray set. X ray equipment Any x ray installation requires an x ray set (generator, control, tube, and support for the patient); a darkroom with processing tanks, chemicals, cassettes, and films; and essential extras such as lead aprons, lead gloves, x ray viewing boxes, and film envelopes. Provided properly designed equipment, such as the World Health Organisation Basic Radiological System (fig 1) is chosen, there is no need to have elaborate rooms with thick walls and lead doors. Local materials may be used; a firm and fairly flat floor is essential, and the ceiling height must be not less than 2-5 m. The room must be weatherproof, well ventilated, and at least 18 M2n. There must be easy access for beds and trolleys. The darkroom must be nearby, about 5 m2, preferably with running water. A small storeroom or …