Full Body Scintigraphy
Methods
Nuclear scintigraphy is the recording of radioactive impulses given off by tissues that have been marked by intravenously introduced radioactive substances. The most common are bone scintigraphy, scintigraphy in soft tissue and leukocyte scintigraphy.
In bone scintigraphy there is increased absorption of the radiopharmaceutical (technetium-labelled diphosphonate) by bones that are subject to a higher metabolic rate. Depending on the problem being addressed, recording with the gamma camera is limited either to specific areas or extended to the whole body.
The interesting issue with full body scintigraphy is the distribution of ‘hot spots’ throughout the skeletal system. This method is particularly suited to the search for skeletal metastases. Due to the high degree of sensitivity (small percentage of false-negative findings) it has become the most important method in this field. With the aid of scintigraphy it is possible to discover relevant pathological changes at a stage when an X-ray is still negative. Full body scintigraphy is therefore also part of the comprehensive examination when diagnosing a tumour.
The inflammation scintigraphy registers local radiation activity during absorption of the injected radiopharmaceutical, thereby revealing blood flow distribution.
Medical indication: indication for bone scintigraphy is given for suspected bone metastases, primary bone tumours, osteonecrosis, fatigue fractures (and prosthetic loosening) and to eliminate possible fractures. In compiling a scintigraphy it must be remembered that physiological skeletal changes are accompanied by increased storage. This is particularly true for degenerative diseases and for bones that are still growing (where storage is increased close to epiphyseal fusions).
In particular soft tissue tumours can be defined with scintigraphy in soft tissue. This examination calls for special medical indications.
With leukocyte scintigraphy, leukocytes are removed from the patient, labelled with a radionuclide and then injected back into the patient. The leukocytes accumulate where there is acute inflammation thereby indicating areas of acute and sub-acute infection. This method is particularly helpful in providing information for development of the differential diagnosis of loose or infected artificial joints.