Items tagged “nuclear medicine”

42 results found
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Superscan

A superscan is an imaging appearance on a Tc-99m diphosphonate bone scan which occurs as a result of a high ratio of bone to soft tissue tracer accumulation. Intense osteoblastic activity in the bones causes diminished renal and background soft tissue uptake. Pathology Etiology This appearanc...
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Pelviureteric junction obstruction

Pelviureteric junction (PUJ) obstruction/stenosis, also known as ureteropelvic junction (UPJ) obstruction/stenosis, can be one of the causes of obstructive uropathy. It can be congenital or acquired with a congenital pelviureteric junction obstruction being one of the commonest causes of antenat...
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Graves disease

Graves disease, also known as Basedow disease in mainland Europe 9, is an autoimmune thyroid disease and is the most common cause of hyperthyroidism. Epidemiology There is a strong female predilection (F:M of 5:1), and is most common between 30 and 60 years 14. The incidence is 20 cases per 10...
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Technetium-99m agents

Technetium agents based on the technetium-99m (Tc-99m) radioisotope are frequently used agents in medical imaging. A radiopharmaceutical labeled with Tc-99m constitutes a co-ordination complex in which ligands bond to a central atom of Tc-99m by co-ordinate covalent bonds 4 . The radioactive te...
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Radiopharmaceuticals

Radiopharmaceuticals are drugs that are bound to radioactive substances.  The pharmaceutically active portion determines the activity that will be measured and the radioactive portion emits radiation that can be measured by the scanner. A number of radiopharmaceuticals are used in human imaging...
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Tc-99m sulfur colloid

Technetium-99m sulfur colloid is one of the technetium radiopharmaceuticals. Characteristics photon energy: 140 keV physical half-life: 6 hours biological half-life: 2 to 3 minutes normal distribution: liver: 85% spleen: 10% bone marrow: 5% excretion: hepatic target organ: liver, splee...
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Xenon-133

Xenon-133 is a radiopharmaceutical principally used when a performing VQ scan. Inhalation of this gas can also be used to assess cerebral blood flow. Mode of decay: Beta decay photon energy: 81 KeV physical half-life: 5.27 days biological half-life: 30 seconds normal distribution: lungs <1...
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Iodine-123

Iodine-123 (I123 or I-123) is a radioisotope of the element iodine (atomic number 53) used in nuclear medicine imaging including to scan the thyroid gland.  Uses, dosages, and time of Imaging standard scan: 3.7-14.8 MBq (100-400 μCi) PO, image at 4-6 or 24 hours thyroid cancer scan: 55.5 MBq ...
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Thyroid scintigraphy (I-123)

Thyroid scintigraphy (thyroid scan) is a nuclear medicine examination used to evaluate thyroid tissue.  Clinical indications functional status of a thyroid nodule thyrotoxicosis: differential diagnosis thyroid cancer whole body scan for distant metastases estimation of local residual thyro...
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Tc-99m DMSA

Tc-99m DMSA (2,3 dimercaptosuccinic acid) is a technetium radiopharmaceutical used in renal imaging to evaluate renal structure and morphology, particularly in pediatric imaging for detection of scarring and pyelonephritis. DMSA is an ideal agent for assessment of the renal cortex as it binds to...
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Tc-99m DTPA

Tc-99m DTPA (diethylene-triamine-pentaacetate) is one of the technetium radiopharmaceuticals used in renal imaging and primarily used to measure the glomerular filtration rate (GFR). Characteristics photon energy: 140 KeV physical half-life: 6 hours oxidation state of technetium: +4 biologi...
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PET-CT indications

PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET). PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). Fluorine-18 (F-18) is an unstable radioisotope and has a half-...
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Tc-99m MAG3

Tc-99m MAG3 (mercaptoacetyltriglycine) is one of the technetium radiopharmaceuticals used in renal imaging. Due to favorable energy and dosimetric characteristics, MAG3 radiolabeled with technetium has replaced the iodide-131 Hippuran for the study of renal function (tubular secretion physiology...
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Tc-99m pertechnetate

Tc-99m pertechnetate (Na+ 99mTc O4-) is one of the technetium radiopharmaceuticals used in imaging of thyroid, colon, bladder and stomach. Technetium (99mTc) has eight oxidation states 6, from -1 to +7; specifically, the oxidation state of technetium in the pertechnetate anion (99mTcO4-) is +7....
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Thyroid scintigraphy (Tc-99m)

Tc-99m pertechnetate thyroid scintigraphy (thyroid scan) is a functional nuclear medicine study used to assess the thyroid gland. The uptake of the pertechnetate anion - similar in chemical-physical characteristics to the iodide ion (i. e. ionic size and negative charge) - in the thyroid parench...
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Tc-99m HMPAO labeled WBC

Tc-99m HMPAO (hexamethylpropyleneamine oxime) labeled WBC is one of the technetium radiopharmaceuticals used in WBC imaging. There are three potential radiochemical impurities in the 99mTc-HMPAO: a hydrophilic secondary complex, the free pertechnetate and the reduced 99mTc-hydrolyzate. 1The min...
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Tc-99m MAA

Tc-99m MAA (macroaggregated albumin) is one of the technetium radiopharmaceuticals used in lung perfusion imaging. Characteristics photon energy: 140 KeV physical half life: 6 hours biological half life: 2-3 hours normal distribution: lungs, liver, spleen, kidneys pharmacokinetics: >90% p...
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Scintigraphy performed with Tc-99m labeled RBCs

Tc-99m labeled RBCs - with radiolabelling technique in vivo or in vitro of red cells 3 - is one of the technetium radiopharmaceuticals used in the non-invasive assessment of gastrointestinal (GI) bleeding 2, characterized by high sensitivity (93%) and specificity (95%) 4. It is capable, in fact,...
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Tc-99m sestamibi

Tc-99m sestamibi (sestamibi is a shortening of sesta-methoxyisobutylisonitrile) is one of the technetium radiopharmaceuticals. Characteristics photon energy: 140 KeV physical half-life: 6 hours lipophilic cation normal distribution: thyroid, parathyroid, heart (myocardium) excretion: hepat...
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Tc-99m DTPA (aerosol)

Tc-99m DTPA (diethylenetriamine-pentaacetic acid) (aerosol) is one of the technetium agents and is used in VQ imaging. Characteristics photon energy: 140 KeV physical half life: 6 hours biological half life: 1 hour normal distribution: lungs pharmacokinetics: aerosol deposited in bronhoal...