radioisotopic investigations in endocrinology
DESCRIPTION
Radioisotopic investigations in endocrinology. Indications: thyroid scintigraphy. hyperthyroidia thyroid nodes toxic adenoma thyroid neoplasia hipothyroidia thyroiditis pregnancy. Radiotracers:. 99m Tc , 123 I, 131 I uptake mechanism: - PowerPoint PPT PresentationTRANSCRIPT
Radioisotopic investigations in
endocrinology
Indications: thyroid scintigraphy
hyperthyroidia thyroid nodes toxic adenoma thyroid neoplasia hipothyroidia thyroiditis
- pregnancy
Radiotracers:
99mTc , 123I, 131I uptake mechanism: active uptake; iodine =
organification, hormones synthesis
Image types:
planars (A, P, profil, oblics…)
tomographic Colimator:
- paralel
- pin-hole
Interpretation: Limits, shape dimensions intensity(hiperfixation/hipofixation) uniformity(nodes?) Quantification: rate
node/normaltissue; LD/LS…; thyroid radiotracer uptake (%).
99mTcO4-scintigram:
normal thyroid
scintigraphic images semeiology:
omogen difuse hyperfixation = Basedow d.
difuse hypofixation = hypothyroidia? Node with no uptake = liquid kyst?/
neoplasia? Node with hyperfixation = toxic
adenom? Multiple nodes, hiperfixation… =TMNG
99mTcO4-
Conclusion: Basedow disease
Node with no uptake
(LTD)
Node with no uptake (LTD)
Neoplasia:A - node with hypofixation LTS (99mTc);B - node with no fixation LTS (123I).
99mTc / 123I (131I)
99mTc / 201Tl
99mTcO4-:
multinodular goiter
TcO4- uptake: 2,8% (n: 2 - 6%)
T4(RIA): 9,4 (n: 6,5-13,5)
Important
Iodine alergy do not c.i. the iodine scintigram
complementar investigations: TSH dosage, T3, T4; radioiodine uptake
131I whole body scintigram:
Thyroid neoplasia with multiple metastases (cervical, lung)
131I:
Basedow disease
Precautions:
Different drugs which contain iodine may determine false images (ex. Amiodarone, contrast iodine substances), ATS, thyroid hormones...
3- 6 weeks.
- scintigrafia glandelor suprarenale:
dg.+ al feocromocitomului (MIBG)d.d. adenom Conn / hiperplazie suprarenal\(analog de colesterol marcat cu 131I)
- scintigrafia glandelor paratiroide: dg. de adenom paratiroidian, dg. neoplasm paratiroidian (99mTc MIBI…)
Alte indica]ii