In one continuous scan, PET captures
images of miniscule changes in the body's metabolism cased by the
changes in cells, while CT images simultaneously allow physicians to
pinpoint the exact location, size, and shape of the diseased tissue.
Essentially, small cellular changes are detected with PET and then
precisely located with CT. Combining these two scanner technologies
makes PET/CT superior to either technology alone.
Anatomical:
CT scanners send x-rays through the body, which are then measured by
detectors in the CT scanner. A computer algorithm then processes those
measurements to produce pictures of the body's internal structures.
Metabolic:
PET images begin with an injection of a solution of glucose (sugar)
that has been "tagged" with a radioactive chemical isotope (generally
fluorine 18, or FDG). Metabolically active organs or tumors consume
sugar at high rates, and as the tagged sugar starts to decay, it emits
positrons.
The positrons then collide with electrons, giving off
gamma rays, and a computer converts the gamma rays into images. These
images indicate metabolic "hot spots," often indicating rapidly growing
tumors (because cancerous cells generally consume more sugar/energy
than other organs or tumors).
Procedure
The actual scan usually takes less than 30 minutes, providing comprehensive
diagnostic information to your health care team very quickly. However, the complete exam process can take up to 3 hours (do to contrast administration). The
PET/CT system provides exceptional image quality and accuracy of
diagnostic information.
Preparation for the Exam
The preparation for a PET/CT exam will be given to your patient at the time an appointment is scheduled.
Please
allow up to three hours for a visit, including preparation
for the exam and time in the scanner. Upon arrival, a technologist
will escort your patient to the imaging area and administer a very small amount
of radioactive glucose.
Following the injection, the patient will rest in a
private room for 60 to 90 minutes while the glucose distributes throughout the body. The scanning procedure is performed while lying
comfortably on the scanner bed.
After the Procedure
The
PET exam itself causes no side effects and your patient will be permitted to
drive home. However, if your patient requested a mild sedative be given
to you to relieve anxiety, someone else must drive them home.
Post Exam
The radiologist
will review and interpret the images and send a dictated report.
PET/CT Location
Sacred Heart Center