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Radionuclide Cisternogram Leak Detection

Your doctor has requested a Radionuclide Cisternogram Leak detection study or a CSF leak scan. This booklet will answer some of the questions you may have. 

What is a CSF Leak scan? 

A radionuclide cisternogram or CSF leak scan is an imaging test that follows the pathway of spinal fluid in the spinal column and throughout the brain. This test is useful in determining if any obstructions are present in this pathway. Your physician is particularly interested in knowing if any spinal fluid is leaking from its normal pathway. 

What is involved? 

This procedure will take at least two separate visits to the hospital to complete. The first visit will take most of the day to complete. The remaining visit will take one hour or less to complete. 

If you are taking blood thinning medication, you will be required to stop taking this medication for five days preceding your appointment. If you are taking Diamox (Acetazolamide), you will also need to stop this medication for one week prior to the procedure. Always check with your family doctor before stopping any medications. It is advisable that you travel with someone else on the first day, since the radioactive injection may give you a slight headache and you may not feel up to driving or taking the bus alone. 

Your visit will start in the x-ray department. When you arrive for this appointment, a specially trained doctor will explain the entire procedure to you and ask you to sign a consent form before proceeding. You will then be asked to lie down on an x-ray table and the doctor will give you a small injection of freezing solution in your lower back area. This freezing injection will numb the area where you are to receive the second injection. X-rays will then be taken of your lower back to determine the exact location for the second injection. The doctor will then inject a small amount of radioactive tracer into your spine. There are no known side effects from this injection. Once this injection has been given, you will be asked to get down from the imaging table and lie on a stretcher. You will then be transferred to the Nuclear Medicine department. Here, you will wait, lying down, for an hour after which a nuclear medicine technologist will take a picture of your back to ensure appropriate delivery of the radioactive tracer. We will also take a sample of your blood at this time.  

Now, you will be transferred to the Ear, Nose and Throat (ENT) clinic and a specially trained doctor will insert several cotton gauzes deep into your nasal cavity (nose). The purpose of these gauzes will be to absorb any leaking spinal fluid if present. These gauzes will remain in your nose until all of the imaging is completed at the end of the day.  

You will be brought back to the Nuclear medicine department and wait for about 2 hours before imaging can take place. During this waiting period, you can have your meals. After the appropriate waiting interval has passed, a technologist will bring you into an imaging room and ask you to lie down on another imaging table. The technologist will place a special detector, called a gamma camera close to your head. Several images will then be taken of your head to see how the tracer has moved. We will also take some three-dimensional images of your head. These images take approximately an hour to complete.  

Once all the imaging is done, we will take another sample of your blood. At this point, the cotton gauzes in your nose will be removed. These gauzes will be processed to detect any leaking spinal fluid. 

In order to properly see the spinal fluid travelling through your brain and to note any leaks, it will be necessary for you to have these images repeated on the following day as well. Occasionally, we will need to acquire images at 48 hours as well, based on the discretion of the Nuclear Medicine Physician. You will be instructed when to return for each of these additional appointments before leaving the department.  

Do I need to prepare for the scan? 

  • Bring your Health card. 
  • You will be required to stop anticoagulant therapy for at least 5 days prior to your appointment, after consultation with your physician. 
  • You will be required to stop taking Diamox (Acetazolamide) for one week prior to your appointment, after consultation with your physician.  
  • It is better to have a support person accompany you on your first visit as it takes most of the day to complete and you may not feel up to driving yourself. 
  • Please leave all valuables at home. 
  • Please notify our booking office at the time of scheduling your appointment if you have any concerns regarding claustrophobia, lying still, require a mechanical lift for transfer to the imaging bed, have a language barrier or any other special needs, so that appropriate arrangements can be made ahead to provide you with the best possible care. 

Will it hurt? 

The freezing solution injected into your lower back area should help with any pain that you may experience. However, you may experience a small amount of pressure as the radioactive tracer is injected. Normally this sensation passes in a few minutes. 

The cotton gauze placed into your nose may feel uncomfortable for the short period that they are in place. 

Is the radiation dangerous? 

The amount of radiation used for this procedure is very small and considered safe. The radioactivity will disappear by itself soon after the scan is finished (nearly all of it disappears within one week). The results of your scan will give your doctor useful information about your condition and will help them plan your treatment. The benefits of having the scan far outweigh any potential risk from the small radiation dose.  

Do I need to do anything after the scan? 

Some individuals may get headaches with this type of exam. The best way to avoid this is to remain flat for the first few hours following the injection. If you begin to experience a headache, try lying flat and taking an over-the-counter pain medication. You are encouraged to drink extra fluids for the first 24 hours following your injection. Some patients may experience headaches, back pain, and leg or hip pain. Please go to the emergency department of your nearest hospital if any of these symptoms become severe. 

If you are travelling abroad in the two weeks after your scan, please ask us for further advice. Ports, airports and border crossings have very sensitive radiation detectors which may pick up tiny amounts of radioactivity remaining after your scan. We will give you a letter that you can show to customs officials. 

Is there anything I should tell the staff before the injection? 

Please tell us if you are pregnant or breastfeeding.  

How will I get the results of my scan? 

A specially trained doctor will examine the pictures. This is normally done soon after the end of the scan. A report is then sent to the doctor who asked us to do the scan. Your doctor will normally receive the report within one week. You will also have access to the report on MyChart as soon as it is released. 

If you have questions about the scan results or report, please contact your doctor directly. They are best able to interpret the report for you. 

Will this test cost me money? 

No. This test is paid for by the healthcare system. The test costs several hundred dollars, so please notify the department at 613-761-4831 if you cannot make your appointment. 

What should I do if I cannot make my appointment? 

If you cannot make you appointment, it is important that you notify the department at 613-761-4831 as soon as possible. Failure to make your appointment results in wasting of expensive materials that are ordered especially for your appointment and also reduces availability to other patients. Missed appointments may also result in delays of your treatments. 

Directions and Parking 

Civic Campus  1053 Carling Avenue – 1st Floor Tel.: 613-761-4831, option 8 Hours: Mon. – Fri., 8:00 a.m. – 4:00 p.m. Directions: From within the Civic Campus, take the “C” elevators to the 1st Floor and follow the signs to Nuclear Medicine. Patients may also ask for directions at the patient information desk. General Campus  501 Smyth Road – Main level Tel.: 613-761-4831, option 8 Hours: Mon. – Fri., 7:00 a.m. – 4:00 p.m. Directions: From the main entrance, follow the signs on the main level (located at the public elevators). Patients may also ask for directions at the patient Information desk. 
Park in either parking lot off Carling Avenue (P7) or in the multistory parking garage (P1).  Park in the parking garage which is located beside the main entrance just off Smyth Road.  

Parking instructions 

  • All parking lots are automated  
  • Take the parking ticket with you inside.  
  • When you have completed your appointment, you can pay by cash or credit card at one of our pay stations, or you can pay by credit card with express exit at the parking lot exit gates (the grace period after payment to leave facility is 20 minutes). 
  • Payment methods: 
    • Pay stations: Cash or credit card (Visa, MasterCard or American Express). 
  • Maximum parking fee is $13.00 

Visit The Ottawa Hospital’s website for additional directions and parking instructions and maps.

Please note that your first appointment will be in the x-ray department. Please refer to the hospital website for directions to the x-ray department.

Last updated on: May 25th, 2022