Implementation | Scintigraphy

Implementation

Before the beginning of the scintigraphy no major preparations are usually necessary. However, depending on which organ/tissue is to be examined, certain guidelines can be made, so that the intake of medication may not always be continued or a fasting condition (especially in the case of examinations of the gastrointestinal tract) must be maintained. At the beginning of the scintigraphic examination, the patient is injected with the radioactive agent into the bloodstream via the arm vein (usually via the vein in the crook of the arm).

Afterwards, depending on the radiopharmaceutical used, the patient must wait for varying lengths of time until the radioactive substance has spread throughout the body and accumulated in the desired tissues/organs (usually waiting times range from a few minutes to 1-3 hours). Since the injected radiopharmaceutical is usually excreted via the kidneys, care should be taken to ensure that the patient drinks a lot of fluids during the waiting period and visits the toilet several times to prevent the radioactive substance from accumulating in the bladder. This reduces the radiation exposure due to the faster excretion on the one hand, and on the other hand it enables better resolution and quality of the images.

During the creation of the scintigram, the patient sits or lies in a prone or supine position under the detecting gamma camera, whereby the latter is usually a predominantly open camera system (no tube system as with an MRI/CT).The duration of the imaging also varies and depends on the organ to be imaged and the respective question: imaging of the thyroid gland as a relatively small organ takes about 5 minutes on average, whereas imaging of the bones or the entire skeleton takes about 20-40 minutes up to 1 hour. The patient should lie/sit as still as possible during the entire examination in order to prevent “blurring” of the image and to enable a scintigram that is as accurate and sharp as possible. How long a scintigraphy takes depends on the organ examined and the radioactive substance used.

On the one hand, the time period from injection to recording and distribution in the target organ varies. On the other hand, the radioactive particles decay at different rates. In addition, the time required for the recording with the camera is different for each type of scintigraphy.

It follows that a thyroid scintigraphy is usually completed after 30 minutes. For lung and kidney, 30 to 60 minutes must be planned. Bone and heart scintigraphy in particular, on the other hand, can take considerably more time, since these examinations often require several and sometimes very late scans. Therefore, the scintigraphy can take up to 5 hours in total. Most of the time, however, must be waited for and the actual examination only takes a few minutes per image.