Parathyroid Scintigraphy - European Association of Nuclear Medicine

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within the last 6 weeks (CT with contrast,
IVU etc). Allow a period of 6 weeks between
these procedures and thyroid imaging.
Iodine-containing medications may have to
be withdrawn, and the referring clinician’s
advice should be sought. These medications
include: propylthiouracil, meprobamate,
phenylbutazone, sulphonamides,
corticosteroids, ACTH, perchlorate, antihistamines,
enterovioform, iodides, Lugol’s
solution, vitamin preparations, iodine ointments
and amiodarone.
Before any pharmaceuticals are ordered,
check whether the patient has had a total
thyroidectomy. If this is the case, then the
subtraction technique should not be carried
out and consideration should be given
to undertaking a dual-phase 99m Tc-sestamibi
study.
Ask the patient whether he or she has any
thyroid disorders such as thyrotoxicosis,
hypothyroidism, thyroid nodules or thyroid
goitre. These conditions can increase
instances of false-positive 99m Tc-sestamibi
uptake and also affect 123 I sodium iodide
uptake. In the case of hypothyroidism, do
not carry out the subtraction technique and
consider undertaking a dual-phase 99m Tcsestamibi
study.
Ask the patient whether he or she is able to
lie supine for the duration of the study and
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also whether he or she is claustrophobic.
Consider another imaging modality if the
patient cannot lie still for the duration of the
study owing to discomfort or anxiety.
Although 123 I sodium iodide contains little
carrier-free iodide, it is important to ask
the patient about any adverse reactions
to iodide in the form of contrast media or
medication. If positive, seek the advice of
the lead clinician.