CT Scan

St. Mary's Medical Center, 1st Central
(865) 545-7982
Fax: 545-8977
Hours: 6 a.m.-8 p.m., Monday-Friday; 8 a.m.-12 p.m., Saturday; and 1 p.m.-4 p.m., Sunday

St. Mary's North
(865) 859-7000
Fax: (865) 859-7300
Hours: 8 a.m.-4:30 p.m., Monday-Friday

Services offered:

• Orthopedic-spines, joints extremities
• Vascular-CT arteriograms
• 3-D reconstructions/reformations
• Radiation Therapy CT localization
• Steriotactic and stealth procedures in conjunction with Neurosurgeon
• Biopsies and abcess drainages
• Routine body and head scanning

All registered ASRT technologists with advanced registries

Computed Tomography (CT)

The department is equipped with two helical Computed Tomography (CT) scanners (a Lightspeed and a CTi) and has a dedicated staff of nine to offer 24-hour care, 7 days a week. Approximately 12,000 exams are performed annually.

Overview:
Computed Tomography (CT) imaging, also known as CAT Scan (Computed Axial Tomography) was developed in the 1970's. X-rays passing through the body and registering on a detector produce CT images. Next a dedicated computer converts the information into a two dimensional image of the "slice" that was scanned.

Exams:
Patients are encouraged to wear loose comfortable clothing with minimal amount of metal. Initial registration occurs at Outpatient admitting on LL2. Depending on the test scheduled a patient's next stop will be the outpatient lab for blood work or 1st Central where he will check in at the Radiology Desk (right where the elevator lets out). Any patient 65 years or older who will be receiving IV contrast will be required to have lab work to assess renal function before the CT can be performed. At the Radiology desk a brief medical history will be obtained and that information will be sent back to the technologist, who will have one of the Radiologists (x-ray doctors) tailor the exam to meet the individual's needs.

Computed Tomography uses two types of contrast:
1. Oral contrast — to enhance the stomach, small bowel, and colon.
2. IV contrast (also referred to as x-ray dye) — to enhance the blood vessels and organs. This will require a needle stick to start the IV line.
Each exam is tailored to the individual so a patient may receive no contrast, oral contrast alone, IV contrast alone, or a combination of both oral and IV contrasts.
The actual scan only takes a few minutes but the preparation for each test varies.

CT HEAD
Without Contrast — Please remove bobby pins, earrings, partials, and dentures containing metal before exam. The scan will take approximately 10 minutes after entering the room.
With Contrast — Same as without but an INT will be inserted into a vein to administer the IV contrast. The scan will take approximately 15 minutes after entering the room.

CT STEREOTACTIC and STEALTH
These are CT scans of the head that are set up in conjunction with the Neurosurgeon to be used for localization during surgery.

CT SINUSES
Without Contrast — Please remove bobby pins, earrings, necklaces, partials, and dentures containing metal before the exam. The scan will take approximately 10 minutes after entering the room. If your physician requires copies of your films there will be a brief wait after the test to make copies of the films.

CT CHEST
Without Contrast — Please remove necklaces before the exam and it is recommended to were a shirt/blouse without snaps or metal buttons. This way you will not have to change into a hospital gown for the exam. The scan will take approximately 10 minutes after entering the room.
With Contrast - Same as without but an INT will be inserted into a vein to administer the IV contrast. The scan will take approximately 15 minutes after entering the room.

CT ANGIO CHEST
This exam always requires IV contrast. The scan from a patient-standpoint is identical to a CT Chest with contrast. The difference occurs in how the technologist obtains the raw data with the scanner and how the information is processed on the computer.

CT ARTERIOGRAMS
This exam always requires IV contrast. Once the Radiologist determines the start and endpoints of the exam, the technologist will do the scan. The scan usually takes a matter of minutes. After the patient is dismissed the technologist will do some special processing of the information. For this reason it will take at least one hour before any final results will be available.

CT ABDOMEN
Without Contrast — Please minimize the amount of metals located on your shirt and slacks to avoid having to be changed into a hospital gown. The scan will take approximately 10 minutes after entering the room.
With Oral Contrast — Same as without contrast but, it is required that the patient does not eat or drink anything 4 hours prior to starting the oral prep. This is so the contrast will coat evenly. When drinking the contrast it is important to sip it (so all the contrast will not be in one area) over the course of the required hour (it takes this long to get far enough in the system). It is not necessary to stay in the radiology waiting area to drink the oral contrast. It can be picked up in advance and drank at home if desired. The scan will take approximately 15 minutes after entering the room.
With IV and Oral Contrast — Same as the Oral only study but an INT will be started into a vein to administer the IV contrast. The scan will take approximately 15 minutes after entering the room.

CT PELVIS
Without Contrast — Please minimize the amount of metals located on the slacks to avoid having to be changed into a hospital gown. The scan will take approximately 10 minutes after entering the room.
With Oral Contrast — Same as without contrast but, it is required that one does not eat or drink anything 4 hours prior to starting the oral prep. This is so the contrast will coat evenly. When drinking the contrast it is important to sip it (so all the contrast will not be in one area) over the course of the required two hours (it takes this long to get far enough in the system). It is not necessary to stay in the radiology waiting area to drink the oral contrast. It can be picked up in advance and drank at home if desired. The scan will take approximately 15 minutes after entering the room.
With IV and Oral Contrast — Same as the Oral only study but an INT will be started into a vein to administer the IV contrast. The scan will take approximately 15 minutes after entering the room.

CT RADIATION THERAPY LOCALIZATION
These exams are done in conjunction with the radiation oncology department. A technologist from Radiation Therapy will come to the CT department and with the CT technologist set up a body part scan determined by the Radiation Oncologist. This is used to set up treatment plans for Radiation Therapy.

CT BIOPSIES AND DRAIN PLACEMENTS
These exams are considered surgical procedures. A Radiologist, Technologist and Nurse will be working together to perform the procedure. Patient will be required to show up well before the procedure will take place in order to obtain required lab work and have an INT placed so the patient can receive intravenous pain medicine. Patients are not put to sleep for these exams. The scanner is used to locate the area of interest. A mark is placed on the skin surface. This marked area is numbed with zylocaine. A needle is inserted to the area of interest and the technologist uses the scanner to verify that the positioning is correct. For a biopsy a sample is taken through a needle. For a drain a guidewire is inserted into the fluid collection and used to place the drainage catheter in the correct position. The time the procedure takes will vary by individual, but seldom exceeds one hour after entering the scan room.

CT 3D
3D is not a scan but a way in which the technologist processes the computer information. At St. Mary's any helical exam can be converted into a 3D exam.

The scans listed above are the most common but any body part may be scanned.

Thank you for choosing St. Mary's for your health care needs.

For more information about CT Scans please contact Janie Williams at jwilliam@stmaryshealth.com.