Tracer Notes


Table Of Contents

q    Cardiovascular Imaging. 3

q    Pulmonary System.. 3

q    Skeletal System.. 3

q    Gallium 67 Citrate. 3

q    Indium -111 Labeled Leukocytes. 4

q    Technetium -99m HMPAO - Labeled Leukocytes. 4

q    Liver Spleen study. 4

q    I-123 metaiodobenzylguanidine (MIBG) 4

q    Octreotide. 4

q    Hepatobilary System.. 4

q    Gastointestinal System.. 5

q    GU.. 5

q    Thyroid imaging. 6

q    Parathyroid. 6

q    CNS. 6

q    LYMPHOSCINTIGRAPHY.. 6

q    Dose 5 mCi 8

q    Dose 10 mCi 8

q    Dose 20+ mCi 8

q    Other 8

 


q  Cardiovascular Imaging

o       Thallium 201- chloride

·       2-3.5 mCi

·       Window 69-83 KeV, can use 2nd window of 167 KeV to increase counts.

·       Critical organ = Kidneys

o       Technetium-99m sestamibi

·       Same day rest and stress: initially done with 10mCi, 2nd is done 3-4 hrs later using 20-30 mCi (account for residual activity)

·       Critical Organ = GB, if no GB then Colon

q  Pulmonary System

o       Tc-99m macroaggregated albumin (Tc-99m MAA) - typical 5 mCi dose 500,000 particles

·       Critical organ = Lungs

o       Tc-99m DTPA give 20-30 Mci Aerosol -  1 MCi (reaches lungs)

o       Xenon

o       Single Breath

·       Deep inspiration, patient hold breath while 100,000 count image is acquired

o       Equilibrium

·       Patient breaths air and Xenon and image acquired every 60 sec for 3 min

o       Washout

·       Patient breaths room air and serial images are obtained

·       Good for air trapping in COPD, will show inreased tracer on delayed images

q  Skeletal System

o       Techneium 99m MDP

·       ½ - 6 hrs

·       Kev =140

·       Dosage 15-25 mCi

·       Critical organ = bladder

q  Gallium 67 Citrate

o       ½ life 78 hours

o       circulates bound to transferrin

o       Uptake highest in liver but also spleen ,salivary glands, bone marrow and Lacrimal gland, kidneys only faintly seen at 48-72 hrs

o       Photo peaks are 93, 185 and 300

o       Infection 5 mCi  

o       Tumors 10  mCi

o       Critical organ = Colon

o       Typically image at 48 (BEST) and 72 hrs

q  Indium -111 Labeled Leukocytes

o       ½ life = 67 hrs

o       Typically image at 24 hr

o       Photopeak = 173 and 247 Kev

o       Critical organ = Lungs

o       Dose = 500 uCi in adults

q  Technetium -99m HMPAO - Labeled Leukocytes

o       Dose - 10 mCi

o       Critical organ = Colon

o       Image at 1-2 hrs for IBD 4-6 for other (osteo, etc..)

o       Better for peds due to lower radiation dose and extremities

q  Liver Spleen study

o       T99m-sulfur or albumin

o       Dose = 4-6mCi; inj-to-imaging 20min

q  I-123 metaiodobenzylguanidine (MIBG)

o       pheochromocytoma and neuorblastoma

o       precursor of norepinephrine

o       Normal MIBG activity should be confined to the heart, salivary glands, liver, spleen, and bladder, with some excretion into the GI tract.

o       Image at 24, 48 and 72 hours

o       Dose - 10 mCi

q  Octreotide

o       Imaging is useful for detecting a variety of neuro-endocrine tumors which contain somatostatin receptors, including VIPomas, insulinomas, gastrinomas and pheochromocytomas

o       Pentetreotide is a somatostatin analog (In-111 Pentetreotide (Octreotide)

o       Dose = 6 mCi

o       Accumulates in the thyroid and salivary glands, spleen, liver, and kidneys, with excretion into urinary bladder and bowel (mainly on 24 hour images)

q  Hepatobilary System

o       Tc-99m mebrofenin (Choletec)

o       Dose – 5 mCi

o       Critical organ = Colon

o       Sincalide (Kinevac) is synthetic CCK dose is - .02 µg/kg

o       Morphine - .04mg/kg about 2 mg

q  Gastointestinal System

o       Diabetic Gastroparesis

·       Most common cause (vagal nerve damage?)

·       1 mCi of technetium-99m sulfur colloid microwaved with 30 grams of liver pate.

o       Sulfer Colloid (GI bleed)

·       Dose - 10 mCi

·       Critical organ = Liver

o       Meckel scan

·       Tc99m-pertechnetate  Dose - 10mCi for child 20 for adult 

·       Critical organ = Stomach

o       GI Bleeding Study

·       Tc-99m Tagged Red Blood cells

·       Critical organ = Heart

·       Dose = 20 mCi

·       Use in vitro Ultratag KIT

o       Denver shuntogram

·       Peritoneal-venous shunting (Denver shunt) is used in cases of intractable ascites

·       5.5 mCi Tc-99m maa intraperitoneally

o       ESOPHAGEAL TRANSIT (done for reflux)

·       Tc99m-sulfur or albumin colloid

·       Oral, 0.15-0.30mCi;

·       Igestion-to-imaging:immediate

·       NPO=4-6hrs

·       Normal, 90% activity should have transferred esophagus in 15sec.

o       GERD (kids)

·       Tc99m sulfur or albumin colloid; 140keV, T1/2=6hrs.

·       Oral in 150cc of orange juice mixed with 150cc of 0.1N HCl; 0.3mCi, Imm

·       More than 4% of gastric activity back in esophagus is abnormal.

q  GU

o       Tc-99m DTPA – Dose - 20 mCi

·       Critical organ = bladder

o       Tc-99m MAG3 (mercaptylacetyltriglycine) Dose - 8 mCi

·       Critical organ = bladder

o       Tc-99m DMSA (dimercaptosuccinic acid) Tubular agent

·       Critical organ = kidney

o       Lasix (routine is 40mg IV)

o       enalaprilat (40 ug/kg, maximum of 2.5 mg)

o       RADIONUCLIDE CYSTOGRAM

·       Tc99m pertechnetate(prefer)

·       Tc99m-sulfur colloid/DTPA

·       Can also be used.

·       Sterile urethral catheterization.0.5-1.0mCi mixed with 250-300cc of saline

·       Used in pediatric as VCUG, less radiation.

o       TESTICULAR SCAN

·       Tc99m pertechnitate/DTPA

·       IV, 30mCi; Inj-to-imaging: immediate

·       Delay in 15min.

q  Thyroid imaging

o       Iodine-123

·       decays by electron capture,

·       Gamma energy of 159 keV.

·       Dose -200-400 uCi

·       Critical organ = thyroid

o        Iodine -131 .

·       Critical organ = thyroid

·       Dose 

o   Diagnostic: 2-5 mCi po for whole body for following a patient with thyroid carcinoma.
Therapeutic: 80-150 uCi per gram of thyroid tissue for Graves' disease

o   100-200 mCi for thyroid carcinoma ablation in thyroid neoplasm

o       Technetium-99m Pertechnetate

·       Dose - 3 mCi intravenously

o       % Uptake = (normal = 10 - 30 %).

q  Parathyroid

o       Tc99m Sestamibi

·       Dose 20 mCi

·       Image at 15 min and 2 hrs

q  CNS

o       Tc99m-HMPAO (Hexamethylpropylenamine oxime): Ceretec

·       Dose – 20 mCi - Flow study

o       CISTERNOGRAM

·       In111-DTPA - Spinal injection, 0.5mCi

q  LYMPHOSCINTIGRAPHY

·       Filtered Tc99m sulfur colloid

·       Intradermal or peritumoral 4-8 injections within 1cm of biopsy/tum.

·       0.1mCi, immediate


Dose 5 mCi

o       Technetium-99m Pertechnetate  (thyroid) - 3 mCi

o       Iodine -131 - 2-5mCi

o       Choletec – 5 mCi

o       MAA – 5 mCi for VQ and Denver shunt

o       Gallium 67 – 5 mCi for infection

q  Dose 10 mCi

o       Octreotide – 6 mCi

o       Tc-99m MAG3 (mercaptylacetyltriglycine) - 8 mCi

o       Sulfer Colloid (GI bleed) - 10 mCi

o       Technetium -99m HMPAO - Labeled Leukocytes - 10 mCi

o       MIBG - 10 mCi

o       Gallium 67 – 10 mCi for Tumor

q  Dose 20+ mCi

o       Techneium 99m MDP - 15-25 mCi

o       Tc99m Sestamibi - 20 mCi

o       Tc99m-HMPAO CNS - 20 mCi

o       Tc-99m DTPA GU –   20m

o       Tc-99m Tagged Red Blood cells - 20 mCi

o       Tc-99m DTPA - 20-30 mCi Aerosol -  1 MCi (reaches lungs)

o       Tc99m pertechnitate/DTPA (Testicle) -  30mCi

q  Other

o       Iodine-123  - 200-400 uCi

o       Indium -111 Labeled Leukocytes - 500 uCi in adults

o       In111-DTPA - Spinal injection, 0.5mCi