Tc99m Flashcards
What is the half-life of Tc99m?
6 hours
What is the energy of Tc99m
140 keV
Cardiolite/Sestamibi
Myocardial perfusion agent for detecting CAD by localizing myocardial ischemia (reversible defects) & infarction (non-reversible defects). Also used in evaluating myocardial function and the evaluation of breast lesions.
Cardiolite/Sestamibi Clinical Pharmacology
Technetium Tc 99m Sestamibi is a cationic complex which has been found to accumulate in viable myocardial tissue in a manner analogous to that of thallous chloride TI-201.
Cardiolite/Sestamibi Dose & Administration
Myocardial Imaging suggested dose is 10-30 mCi. Breast Imaging recommended dose range for I.V. administration is a single dose of 20-30 mCi
Ceretec (EXAMETAZIME)
Tc99m exametazime scintigraphy may be useful as an adjunct in the detection of altered regional cerebral perfusion in stroke. It is also indicated for leukocyte labeled scintigraphy as an adjunct in the localization of intra-abdominal infection and inflammatory bowel disease.
Ceretec (EXAMETAZIME) Clinical Pharmacology
When technetium Tc99m pertechnetate is added to exametazime in the presence of stannous reductant, a lipophilic technetium Tc99m complex is formed. This lipophilic complex is the active moiety. It converts at approximately 12%/hour to less lipophilic species. When the secondary complex is separated from the lipophilic species, it is unable to cross the blood-brain barrier. The useful life of the reconstituted agent is limited to 30 minutes.
Ceretec (EXAMETAZIME)
Tc99m labeled leukocytes for a normal adult (70 kg) dose is 7-25 mCi by IV. Cerebral Scintigraphy recommend dose range for IV, of reconstituted sodium pertechnetate, in the average adult (70 kg) is 10-20 mCi
Disofenin
Technetium Tc99m Disofenin is indicated as a hepatobiliary imaging agent. Hepatolite is indicated in the diagnosis of acute cholecystitis as well as to rule out the occurrence of acute cholecystitis in suspected patients with right upper quadrant pain, fever, jaundice, right upper quadrant tenderness and mass or rebound tenderness, but not limited to these signs and symptoms
Disofenin Clinical Pharmacology
an iminodiacetic acid derivative with no known pharmacologic actions at the doses recommended. Disofenin is rapidly cleared from the circulation of normal individuals following intravenous administration; about 8% of the injected activity remains in the circulation 30 minutes post-injection
Disofenin Dose & Administration
5 mCi
DSMA
DMSA is an aid in the evaluation of renal parenchymal disorders
DSMA Clinical Pharmacology
After intravenous administration, Tc99m succimer injection is distributed in the plasma, apparently bound to plasma proteins. There is negligible activity in the red blood cells. The activity is cleared from the plasma with a halftime
of about 60 minutes and concentrates in the renal cortex. Approximately 16% of the activity is excreted in the urine within two hours. At six hours about 20% of the dose is concentrated in each kidney.
DSMA Dose & Administration
The suggested dose range for slow I.V. administration is 74-222 MBq or 2-6 mCi.
DTPA
: Brain imaging in adults. Renal visualization, assessment of renal perfusion, and estimation of glomerular filtration rate in adult and pediatric patients. Lung ventilation imaging and evaluation of pulmonary embolism when paired with perfusion imaging
DTPA Clinical Pharmacology
Intravenous Administration - Following intravenous administration for brain and renal imaging, pentetate is distributed in the vascular compartment. It is cleared by the kidneys, which results in the ability to image the kidney.
Aerosolized Inhalation Administration - Following inhalation of the aerosol, pentetate deposits on the epithelium of ventilated alveoli.
Brain Imaging - Pentetate with intravenous administration tends to accumulate in intra-cranial lesions with excessive neovascularity or an altered blood brain barrier. Pentetate accumulation in the brain is prevented by an intact blood brain barrier. It does not accumulate in the choroid plexus.
Renal Scintigraphy - The first few minutes after intravenous administration, pentetate is present in the vascular compartment within the renal system.
Lung Ventilation Imaging - In patients with normal lungs, the deposition of pentetate is homogeneous throughout the lungs. In patients with airway disease, the deposition patterns become inhomogeneous with irregular deposition of pentetate in the airways and alveolar regions of the lung.
DTPA Dose & Administration
Brain imaging is 10-20 mCi. Renal visualization and perfusion assessment is 10-20 mCi. Renal visualization with estimated GFR is 3-5 mCi. GFR alone is 0.2-0.5 mCi. Lung ventilation is 25-50 mCi in a nebulizer.
Lymphoseek/Tilmanocept
Lymphatic mapping using a handheld gamma counter to locate lymph nodes draining a primary tumor site in patients with solid tumors for which this procedure is a component of intraoperative management. Guiding sentinel lymph node biopsy using a handheld gamma counter in patients with clinically node negative squamous cell carcinoma of the oral cavity, breast cancer or melanoma.
Lymphoseek/Tilmanocept
Lymphoseek accumulates in lymphatic tissue and selectively binds to mannose binding receptors (CD206) located on the surface of macrophages and dendritic cells.
Lymphoseek/Tilmanocept
0.5 mCi subdermal injection
MAA
MAA is a lung imaging agent which may be used as an adjunct in the evaluation of pulmonary perfusion. MAA may be used in adults as an imaging agent to aid in the evaluation of peritoneovenous (LeVeen) shunt patency
MAA Clinical Pharmacology
Immediately following intravenous injection, more than 80% of the albumin aggregated is trapped in the pulmonary alveolar capillary bed. The imaging procedure can thus be started as soon as the injection is complete. Assuming that a sufficient number of radioactive particles has been used, the distribution of radioactive aggregated particles in the normally perfused lung is uniform throughout the vascular bed, and will produce a uniform image. Areas of reduced perfusion will be revealed by a corresponding decreased accumulation of the radioactive particles, and are imaged as areas of reduced photon density.
MAA Dose & Administration
1-4 mCi for lung imaging. 1-3 mCi for shunt studies.
It should not be administered to patients with severe pulmonary hypertension.
MAG3
MAG3 is a renal imaging agent for use in the diagnosis of congenital and
acquired abnormalities, renal failure, urinary tract obstruction, and calculi. It is a diagnostic aid
in providing renal function, split function, renal angiograms, and renogram curves for whole kidney and renal cortex.
MAG3 Clinical Pharmacology
Following intravenous injection of MAG3, the appearance, concentration, and excretion of the tracer in the kidney can be monitored to assess renal function. Although MAG3 is highly plasma protein bound following intravenous injection, the protein binding is reversible and the tracer is rapidly excreted by the kidneys via active tubular secretion and glomerular filtration. Following intravenous injection of MAG3 in normal volunteers, 89% of the tracer was plasma protein bound. In healthy subjects with normal renal function was rapidly cleared from the blood. The plasma clearance was approximately 0.3 liters/minute and the amount of MAG3 excreted in the urine in
three hours was nearly 90% of the dose.
MAG3 Dose & Administration
The suggested dose for renal function and imaging studies is 185 MBq (5 mCi) to 370 MBq (10 mCi). In pediatric patients the recommended dose range is 2.6 MBq/kg (70 μCi/kg) to 5.2 MBq/kg (140 μCi/kg) with a minimum dose of 37 MBq (1 mCi).
MDP
MDP may be used as a bone imaging agent to delineate areas of altered osteogenesis.
MDP Clinical Pharmacology
When injected intravenously, MDP is rapidly cleared from the blood; about 50 % of the dose is accumulated and retained by the skeleton, while the remaining 50 % is excreted in the urine within 24 hours. About 10 % of the injected dose remains in the blood at 1 hour post-injection, 5% at 2 hours, and less than 1% remains at 24 hours. The resultant blood clearance curve is tri-exponential with the two fastest components accounting for all but a few percent of the injected dose.
After injection of Medronate, skeletal uptake occurs as a function of blood flow to bone and bone efficiency in extracting the complex. Bone mineral crystals are generally considered to be hydroxyapatite, and the complex appears to have an affinity for the hydroxyapatite crystals in the bone. The rapid blood clearance provides bone to soft-tissue ratios which favor early imaging. The skeletal uptake is bilaterally symmetrical and is greater in the axial skeleton than in the long bones. Areas of abnormal osteogenesis show altered uptake making it possible to visualize a variety of osseous lesions.
MDP Dose & Administration
The recommended adult dose is 370 to 740 megabecquerels (10 to 20 millicuries [200 μCi/kg]) by slow intravenous injection over a period of 30 seconds. Optimum scanning time is 1 to 4 hours post-injection
Mebrofenin
Hepatobiliary imaging agent
Mebrofenin Clinical Pharmacology
Following administration of Mebrofenin was rapidly cleared from the circulation. The mean percent injected dose remaining in the blood at 10 minutes was 17%. The injected activity was cleared through the hepatobiliary system with visualization of the liver by 5 minutes and maximum liver uptake occurring at 11 minutes post-injection. Hepatic duct and gallbladder visualization occurred by 10 to 15 minutes and intestinal activity was visualized by 30 to 60 minutes in subjects with normal hepatobiliary function
Mebrofenin Dose & Administration
5 mCi
Myoview
MYOVIEW is indicated for scintigraphic imaging of the myocardium following separate administrations under exercise and/or resting conditions. It is useful in the delineation of regions of reversible myocardial ischemia in the presence or absence of infarcted myocardium.
Myoview Clinical Pharmacology
When technetium Tc99m pertechnetate is added to tetrofosmin in the presence of stannous reductant, a lipophilic, cationic technetium Tc99m complex is formed
Myoview Dose & Administration
5-33 mCi
Neurolite
Neurolite SPECT is indicated as an adjunct to conventional CT or MRI imaging in the localization of stroke in patients in whom stroke has already been diagnosed.
Neurolite is not indicated for assessment of functional viability of brain tissue
Neurolite Clinical Pharmacology
Bicisate for Injection forms a stable, lipophilic complex which can cross the blood brain barrier. Technetium Tc99m Bicisate crosses intact cell membranes and the intact blood brain barrier by passive diffusion. Five percent of the injected dose remains in the blood at one hour. The amount of Technetium Tc99m Bicisate in the brain is stable until about 6 hours.
Neurolite Dose & Administration
10-30mCi
PYP
PYP is a bone imaging agent used to demonstrate areas of altered osteogenesis, and a cardiac imaging agent used as an adjunct in the diagnosis of acute myocardial infarction.
PYP Clinical Pharmacology
When injected intravenously, Pyrophosphate has a specific affinity for areas of osteogenesis. It is also concentrated in the injured myocardium, primarily in areas of irreversibly damaged myocardial cells.
PYP Dose & Administration
Bone Imaging - 185-555 megabecquerels (5-15 mCi)
Cardiac Imaging - 370-555 megabecquerels (10-15 mCi)
Blood Imaging - 555-740 megabecquerels (15-20mCi)
Sulfur Colloid
Sulfur Colloid is used in adults and children as an agent for imaging areas of functioning retriculoendothelial cells in the liver, spleen and bone marrow.
It is used orally in adults and children for esophageal transit studies, gastroesophageal reflux scintigraphy, and for the detection of pulmonary aspiration of gastric contents.
Sulfur Colloid may be used in adults as an imaging agent to aid in the evaluation of peritoneo-venous (LeVeen) shunt patency.
Sulfur Colloid Clinical Pharmacology
Following intravenous administration, Sulfur Colloid is rapidly cleared by the reticuloendothelial system from the blood with a nominal clearance half-life of approximately 2 1/2 minutes. Uptake of the radioactive colloid by organs of the reticuloendothelial system is dependent upon both their relative blood flow rates and the functional capacity of the phagocytic cells. In the average patient 80 to 90% of the injected collodial particles are phagocytized by the Kupffer cells of the liver, 5 to 10% by the spleen and the balance by the bone marrow.
Following administration of Sulfur Colloid by intraperitoneal injection, the radiopharmaceutical mixes with the peritoneal fluid. Clearance from the peritoneal cavity varies from insignificant, which may occur with complete shunt blockage, to very rapid clearance with subsequent transfer into the systemic circulation when the shunt is patent.
Serial images should be obtained of both the shunt and liver (target organ). However, an adequate evaluation of the difference between total blockage of the shunt and partial blockage may not be feasible in all cases.
Sulfur Colloid Dose & Administration
Liver-Spleen imaging is 37 to 296 megabecquerels (1 to 8 millicuries) and for bone marrow images is 111 to 444 megabecquerels (3 to 12 millicuries)
Gastroesophageal and Pulmonary Aspiration suggested oral dose range is 5.55-11.1 megabecquerels (150-300 microcuries) for gastroesophageal studies. The suggested oral dose range for pulmonary aspiration studies is 11.1-18.5 megabecquerels (300-500 microcuries).
Peritoneo-venous (LeVeen) Shunt Patency Evaluation is 37 to 111 megabecquerels (1 to 3 millicuries).
Technelite/TechneKow
Brain imaging, thyroid Imaging, salivary gland Imaging, urinary bladder imaging (direct isotopic cystography) for detection of vesico-ureteral reflux
Technelite/TechneKow Clinical Pharmacology
The pertechnetate ion distributes in the body similarly to the iodide ion but is not organified when trapped in the thyroid gland. Pertechnetate concentrates in the thyroid gland, salivary glands, stomach and choroid plexus. After intravenous administration it gradually equilibrates with the extracellular space. A fraction is promptly excreted via the kidneys.
Technelite/TechneKow Dose & Administration
100 uCi – 10mCi
HDP
HDP is a diagnostic skeletal imaging agent used to demonstrate areas of altered osteogenesis.
HDP Clinical Pharmacology
During the 24 hours following injection, HDP is rapidly cleared from blood and other non-osseous tissues and accumulates in the skeleton and urine in humans. Blood levels are about 10% of the injected dose at one-hour post-injection and continue to fall to about 6%, 4% and 3% at 2, 3 and 4 hours, respectively. When measured at 24 hours following its administration, skeletal retention is approximately 50% of the injected dose. HDP exhibits its greatest affinity for areas of altered osteogenesis and actively metabolizing bone.
HDP Dose & Administration
20 mCi
Ultratag
Technetium Tc99m-labeled red blood cells are used for blood pool imaging, including cardiac first pass and gated equilibrium imaging and for detection of
sites of gastrointestinal bleeding.
Ultratag Clinical Pharmacology
Following intravenous injection, the Tc 99m-labeled red blood cells distribute within the blood pool with an estimated volume of distribution of approximately 5.6% of bodyweight. The Tc 99m is well retained in the blood pool with an estimated biological half-life of approximately 29 hours. Of the total technetium Tc 99m retained in the whole blood pool 24 hours after administration, 95% remains bound to the red blood cells. Approximately 25% of the injected dose is excreted in the urine in the first 24 hours.
Ultratag Dose & Administration
10-20 mCi
