Our PET-CT technologists are dedicated to securing the best images while attending to patients’ comfort and concerns. They explain the process before the exam begins and continue communicating with patients throughout the scanning process. Because the PET and CT scans are acquired during the same exam, while the patient is in the same position on the table, Providence Imaging Center PET-CT images provide the most accurate correlation between the metabolism of the body’s tissues and its structures.
PET, positron emission tomography, is an imaging procedure used to measure metabolic activity of cells in the human body. A PET scan produces images of the body’s cellular metabolism, allowing physicians to see how cells in the brain, heart or other body organs are working.
CT, computed tomography, scans produce images of the body’s anatomy or structure. Combining the two allows for a very sophisticated piece of equipment that provides physicians with a powerful tool for the detection and diagnosis of diseases, such as cancer, earlier and more accurately, improving a patient’s chances for a good outcome.
During a PET-CT scan, the patient receives a small IV injection of radioactive material, which travels through the bloodstream toward organs in the body showing increased cellular activity. The radioactive material is detected by the scanner and processed by a sophisticated computer to form a 3-dimensional image of the body.
PET-CT offers many benefits:
- Because PET and CT scans are performed simultaneously, it provides precise correlation of cellular function with anatomical information.
- Definitive diagnosis is achieved sooner, allowing for quicker treatment. It provides precise staging of disease and better monitoring of recurrences. Invasive surgery to determine whether a tumor exists may be avoided.
- PET-CT can be used for treatment planning for Radiation Therapy
Patients should check in 15 minutes prior to their appointment at Providence Imaging Center’s front desk, and will be given a short questionnaire to complete. If the patient will be premedicated with a sedative to relax during the scan, the name and contact number of the patient’s driver will be confirmed at this time.
The patient will then be escorted to the PET-CT area, when any films or image CDs (i.e. MRI, CT, or nuclear medicine images from other facilities) should be handed over to the technologist.
The Injection room is the next stop, where the patient may receive some medication to help relax and a bottle of oral CT contrast to drink. The technologist will start an IV in the patient’s hand or arm to administer the radioactive isotope and the patient will relax in a recliner for an hour. It is important that the patient limit the amount of sensory stimulation and muscle activity during this time so that the isotope only localizes in the abnormal areas of the body.
The patient is then moved to the PET-CT scan room. The PET-CT scanner is a large ring-shaped device with an attached table. The patient will lie very still on the scanning table, which will slide slowly through the opening in the scanner ring. The technologist will give the patient specific instructions on how to breathe during the test. The scan takes about 30 minutes.
The patient will be escorted to the waiting area to meet the person who will be taking him/her home (if an oral sedative was administered). The patient can eat and drink normally after the exam and resume normal activities, but should maintain distance from pregnant women and small children for six hours following the appointment.
There are four kinds of PET-CT scans performed at Providence Imaging Center, including whole body scans, brain scans, heart scans and bone scans.
Whole Body Scan
This scan is used to:
Assist physicians in diagnosing many common cancers, including breast, colorectal, esophageal, head and neck, lung, lymphoma, melanoma, ovarian, pancreatic, thyroid and muskuloskeletal tumors
Identify where the cancer is in the body
Determine if the cancer has spread
This scan is used to:
- Differentiate recurring brain tumors from healthy tissue for targeted radiation therapy
- Before surgery for some seizure disorders
- Differentiate Alzheimer’s disease from dementia that is caused by multiple mini-strokes
This scan is used to:
- Distinguish healthy heart muscle from non-functioning tissue after a heart attack
- Identify whether or not there is adequate blood supply to the heart. Evaluate the extent of heart disease in patients being considered for heart bypass or transplant operations
PET-CT Bone Scan
This scan (18F-Fluoride PET-CT bone imaging) is much more sensitive than traditional nuclear medicine bone scans (99mTc). Per Bryan Winn, PIC Radiologist, it has a higher specificity for bony metastases, due to higher spatial resolution and the ability to directly compare with anatomic CT images (fewer false positives). It is primarily used to:
- Evaluate bones for abnormalities like bony lesions and tumors
- Evaluate post operative fusion patients
Whenever possible, patients or their physicians should have at least two days between time of scheduling and the PET-CT appointment, as there are specific diet and exercise restrictions prior to the exam. Proper preparation is the key to obtaining an optimal PET-CT scan.
Let the scheduler know if s/he is diabetic or is allergic.
The PET-CT coordinator will obtain a short medical history over the telephone, including surgeries and any treatments the patient has undergone, such as chemotherapy, radiation therapy or surgery. The coordinator will also ask about recent diagnostic imaging exams such as MRI, CT or nuclear medicine studies in order to secure copies of the films.
If the patient elects to take medication to relax her/him at the time of the exam, s/he may not drive. A driver is needed following the scan to take the patient home.
The patient will be on a low carbohydrate, high protein diet prior to the exam and asked to refrain from strenuous activity or exercise 24 hours prior to the scan.
A PIC radiologist will review the PET-CT images, compare them to previous pertinent films the patient may have had, and interpret what s/he sees.
The radiologist will then dictate a report, which will be transcribed and sent to the healthcare provider who ordered the exam several days after the exam. Patients should contact their healthcare provider for the results of their PET-CT exam.
Medicare will reimburse for most cancer diagnoses as of June 11, 2013: the first PET is generally covered for initial diagnosis and staging, and up to three follow-up or restaging PET scans for the same cancer diagnosis.
Download a PDF guide that explains Medicare coverage criteria for FDG-PET for Alzheimer’s Disease.
Private payer coverage for PET often reflects that of Medicare but may vary. Providers should obtain coverage and pre-authorization guidelines for PET from their private payers. In general, private payers use CPT codes for PET scans; however, providers should engage with their local private payers for information about their coding requirements.