A DEXA scan, or dual-energy X-ray absorptiometry scan, measures bone density. It helps physicians diagnose the demineralising bone disease osteoporosis and estimate patients' fracture risk. There are various types of DEXA scan equipment, or densitometers, some of which have patient weight limits.
According to Radiology Info, there are two types of DEXA equipment. Central devices measure bone density of the hip or spine and require that the patient lie on a padded platform while a mechanical arm, or imager, passes over the body. Peripheral devices are small, portable machines that measure bone density in the extremities, such as the finger, heel or wrist. The boxlike structures contain a space in which the hand or foot is placed for imaging.
The University of Washington lists Hologic, Norland and Lunar as manufacturers of DEXA densitometers. Equipment specifications reported by each manufacturer indicate that machine weight limits vary by make and model. Older models tend to have lower weight limits that range from 113 to 159kg., while newer-model densitometers accommodate patients weighing up to 204kg.
Since densitometer models vary by facility, discuss concerns regarding DEXA-scan-equipment weight limits with an imaging centre professional before scheduling an appointment. According to Hologic, some facilities will scan the forearm using their central device when densitometer weight limits prohibit hip or spine scanning.