Last Updated: 1/27/2020

Indications: Differentiation of essential tremor due to idiopathic Parkinson's Disease, multiple system atrophy and progressive supranuclear palsy.
 
Contraindications: No recent nuclear medicine or iodine-based contrast studies.
 
Radiopharmaceutical: 4-7 mCi I-123 DatScan intravenous (only available from GE Healthcare Tuesdays - Fridays). DatScan arrives in a 2.5mL volume.  Draw and inject the entire volume.
 
Dose Administration:

1. Administer three (3) drops of SSKI (lugol’s) mixed in one cup of water or one (1) 130mg potassium iodide tablet to the patient, and instruct the patient to drink a further two cups of water.
2. Wait one hour after the administration of SSKI, and inject 5 mCi DatScan intravenously. Use of an IV (any gauge) is recommended to avoid infiltration.
   1. DatScan arrives in a 2.5ml volume within a vial; draw the entire contents of the vial. When charting the dose in CareConnect, note that all 2.5ml was given.
3. Instruct the patient to return in three hours. During the interval, there is no NPO requirement.

1. Insert the head holder into the gantry, and position the patient supine. Stabilize the head as much as possible with tape, Velcro straps, and the foam pads.
2. Position the patient so his/her ear canals line up with the bottom of the FOV.
3. Adjust the radius for each detector to 13.3cm. Rotate the detectors around the patient’s head to ensure it does not touch (it should be very close). Adjust the radii if needed to avoid touching the patient. If adjustment is needed, the radii must be the same for both detectors.
4. Instruct the patient of the need to hold absolutely as still as possible.
5. Select the “DatScan SPECT_CT” workflow, and scan according to the following parameters
   1. Circular acquisition, 128x128 matrix, 1.23 zoom, 30 seconds per stop for 60 stops, 15% window around 159 keV.
   2. The count rate should be around 0.7 kcts/second and 1.5 million kcts for the entire SPECT.
6.  When the scan is completed, process and check for motion. If there is any motion at all, the scan must be repeated.