Brain - Diamox Protocol

Last Updated: 1/27/2020

Purpose: To assess cerebral vascular reserve in patients with transient ischemic attack, completed stroke, or vascular abnormalities. 
 
Contraindications: Known sulfa allergy, acute stroke within three days, and pregnant females. If the patient is pregnant or is unsure of her pregnancy status, consult with a nuclear medicine physician immediately.
 
Radiopharmaceutical and route of administration: 25mCi Tc-99m Neurolite injected intravenously; 1000mg (1g) Diamox solution in 10mL sterile water. The pediatric calculation for Diamox is 14mg/kg.
 
*** Contact main pharmacy 24 hours in advance so they can stock Diamox in our PIXYS***
 
Procedure Day 1 (Diamox Challenge): Scans must be done on a Siemens Symbia

  1. Place the patient in the injection room recliner and start an indwelling IV line (any gauge will suffice).  Have the patient recline and cover him/her with warm blankets.  Turn off the lights and instruct the patient to try to remain calm (no talking, use of electronic devices) for 20 minutes. 
    1. Reconstitute and prepare Diamox solution.  *** DO NOT RECONSTITUE DIAMOX WITH SALINE; USE STERILE WATER ONLY***
    2. The pharmacy will stock Diamox in 500mg vials.  Remove two (2) 500mg Diamox vials from the PYXIS along with a 10ml vial of sterile water.  Inject 5ml of sterile water into each vial and swirl to mix.  When the solution is totally dissolved, use a 10ml syringe to withdraw the contents of each vial.  You should end with 10ml of Diamox solution in the syringe.
  2. After the patient has rested for 20 minutes, quietly enter the injection room and inject the Diamox slowly over 2-3 minutes.  Do not turn on the light (propping the door open will provide enough light).
  3. Wait 20 minutes after the administration of Diamox, then quietly re-enter the room and inject 25 mCi Neurolite.
  4. Acquire a SPECT scan of the brain 30 minutes after the administration of Neurolite.  Instruct the patient to void before starting the scan. Ensure the entire brain is within the field of view.
    1. Use the “5 Diamox” workflow acquisition.
      1. LEHR collimators, 128x128 matrix, zoom set to 1.45, 64 stops, 25 seconds/stop.
      2. The study must be set for “circular,” and the detector radii must be 14cm or lower (extremely close to the patient but not touching).
  5. Process the images and show them to the nuclear medicine physician on duty before allowing the patient to leave.  He will determine if a baseline scan is needed.
 
Day 2 (baseline scan).
  1. Place the patient in the injection room recliner and start an indwelling IV line (any gauge will suffice).  Have the patient recline and cover him/her with warm blankets.  Turn off the lights and instruct the patient to try to remain calm (no talking, use of electronic devices) for 30 minutes. 
  2. After the patient has rested for 30 minutes, quietly re-enter the room and inject 25 mCi Neurolite.
  3. Acquire a SPECT scan of the brain 30 minutes after the administration of Neurolite.  Instruct the patient to void before starting the scan. Ensure the entire brain is within the field of view.
    1. Use the “6 Brain Tomo” workflow acquisition.
      1. LEHR collimators, 128x128 matrix, zoom set to 1.45, 64 stops, 25 seconds/stop.
The study must be set for “circular,” and the detector radii must be 14cm or lower (extremely close to the patient but not touching).