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Parathyroid Images

Parathyroid Sestamibi Study


  • You have been referred for a Parathyroid Sestamibi Study in which imaging is done in two parts: Initial and Delayed.

  • This involves a small amount of sterile liquid “tracer” to be injected intravenously -  similar to having a blood test.

  • The tracer we use is called 99mTc-MIBI (99m-Technetium Sestamibi (1)).

  • There are rarely any side effects with this injection.

  • Initially, we image your neck using a Gamma Camera(2) which has a cone-like lens attached to it (called Pinhole Collimator). This takes 15-20 minutes.

  • We then move you to another room to obtain some 3D imaging (called SPECT/CT (3)) of your neck and chest. This takes 15-20 minutes.

  • With SPECT/CT imaging, a Gamma Camera simply rotates around your body, taking images all the time.

  • Once the Initial Images are completed, we need to wait 2-3 hours before re-imaging your neck.

  • You are allowed to leave the department and eat and drink during this period.

  • When you return, we repeat the Pinhole images and the SPECT/CT images. These images are called Delayed Images. Again, this will take 30 to 40 minutes.

  • Depending on the outcome of your results, you may require another injection but with another type of radiopharmaceutical (99m-Technetium). Only Pinhole images are necessary (no SPECT/CT) at this point.

  • Occassionally at the end of the study, we perform an Ultrasound of your neck to confirm our findings.

  • You receive a slight radiation dose by having a Parathyroid Sestamibi Study ~ up to 3.3 times your yearly background radiation (4).


Patient Preparation:

  • If you are pregnant, trying to fall pregnant or breast feeding, you must inform our staff.

  • If you have had prior imaging e.g. PET, Nuclear Scan, CT, MRI, X-Ray, Ultrasound, etc... please bring these with you.

  • Please also bring your referral and any blood results that you may have had done.

  • There is no preparation for a Parathyroid Sestamibi Study i.e. eat and drink as normal.

  • If you are on any medications, please take these as normal.

  • Wear comfortable clothing and minimise the amount of metal jewellery you have on.

  • All metal objects need to be removed prior to imaging.

  • Important Note: You cannot have this test if you have had a PET or Nuclear Scan within 24 hours prior to this test.

  • If you have had Iodine-131 therapy, allow 4-weeks before having this test. Please ring to discuss booking options.​


Breast-Feeding Mothers: Once you have been given the tracer, you need to stop breast-feeding for two feeds. During this time, you need to express and discard your breast milk. You will need to bottle-feed your child during this period.


(1) 99mTc-MIBI is the radioisotope technetium-99m bound to six (sesta=6) methoxyisobutylisonitrile (MIBI) ligands.

(2) A Gamma Camera is a device that detects gamma-rays (gamma-rays are very similar to x-rays) and does not emit any radiation..

(3) SPECT/CT imaging (Single Photon Emission Computer Tomography / Computer Tomography). CT does emit radiation.

(4) We all receive a yearly background radiation dose ~ 2.4mSv. Parathyroid Sestamibi Study with SPECT/CT ~ 8mSv = 3.3 times yearly background dose.

value. quality care. convenience.

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