Topic 4 Flashcards
The acquisition of a single image or snapshot of a particular structure. the simplest type of nuclear medicine image that looks like a single snapshot of a target anatomy.
•Records and demonstrates all radioactivity from the patient above and below the region of interest
Uses low radiopharmaceutical activity levels.
• Rationale: to minimize radiation exposure to the patients
• Disadvantage: images must be acquired for a preset time or minimum number of counts or radioactive emissions.
• 30 seconds and 5 minutes – time it takes to obtain a sufficient number of counts to produce a satisfactory image.
planar/Static imaging
Examples of planar/static imaging
Lung scan, spot bone scan images, and thyroid images.
This imaging uses a specially designed moving detector or system to produced an image of the entire body or a large body section.
•Gamma Camera collects data as it passes through the body
Whole body imaging
Whole-body Imagine systems:
a.For whole-body bone scans
b.For whole-body tumor imaging.
c.For whole-body abscess imaging
d.For other clinical and research applications.
A flow of a particular structure.
•This provides a series of images that demonstrates blood flow in the body within specific organs.
•This generally used to evaluate blood perfusion to the tissue.
Dynamic Images:
•These can be thought as it sequential or time-lapse image.
•These display the distribution of a particular radiopharmaceutical over the specific period
Dynamic imaging
Common applications of dynamic imaging
1st-pass cardiac studies
Hepatobiliary studies
Gastric emptying studies
Rationale: because all examinations is based on the distribution of radiopharmaceutical within the body.
●In vivo: within the living body
In vivo examinations
Patient preparation:
●Most tests requiring no special preparations
●All metal objects must be removed – because they may mimic or attenuate pathologic conditions.
●Patient may resume all normal activities after completion of a routine procedure
●A survey procedure to evaluate patients with malignancies, diffuse musculoskeletal symptoms, abnormal laboratory results and hereditary or metabolic disorders
●Radiopharmaceutical: Localize in bone and soft tissue structures.
●Skeletal Areas of increase Uptake: result of tumor, infection or fracture.
Bone scintigraphy
Performed to look at the skeletal system and to detect abnormalities such as metastases, stress fracture or a loose prosthesis.
•Can detect a fracture 2 years after an injury
Bone scan
Bone scan Major factors that Influence Uptake:
•Regional blood flow
•Osteoblastic activity
•Extraction efficiency
Radiopharmaceutical used in bone scan
•Tc-99
•Tc-99m
•Tc-99m
Adult dose:
labelled diphosphates
hydroxemethylene diphosphate (HDP)
Methylene diphosphate (MDP)
20 mCi (740 MBq)
Routine Scanning in bone scan
begins 2 – 3 hours after the injection and it takes 30-40 minutes.
A noninvasive study
Purpose:
•Assess cardiac performance
•Evaluate myocardial perfusion
•Measure viability and metabolism
Nuclear cardiology
Procedures in nuclear cardiology
•Exercise radionuclide angiography
•Thallium
•Technitium
201 myocardial perfusion study
99m sestamibi myocardial
perfusion study.
•Performed with a patient using a treadmill or stationary bicycle.
•Used to alter the blood flow to the heart.
Stress test
During stress test what is monitored during procedure?
Heart rate
Ecg
Blood pressure
Symptoms
Alternative to stress test
•Used in place of the exercise test
•Used to alter the blood flow to the heart
•For patient who cannot exercise
•For patient with peripheral vascular disease, neurological problems or musculoskeletal problems
Pharmacological intervention
▪ Used to measure left ventricular ejection fraction.
▪Used to evaluate left ventricular regional wall motion.
▪ requires that the blood be labelled with Tc-99m
▪Cardiac cycle: Divided into 16-20 frames during a gated acquisition.
▪Radiopharmaceutical: Tc-99m labelled red blood cells
▪Adult dose: 25-40 mCi (based on patient’s body surface – height and weight)
Gated exercise radionuclide angiography
Gated exercise radionuclide angiography scanning
▪Begin immediately after the injection
▪Takes about 1 hour
▪ Anterior position
▪Left lateral position
▪Left anterior Oblique position
●A SPECT study that is used to identify perfusion defects in the left ventricular wall.
●Useful for assessing myocardial viability in patients with known Coronary Artery Disease.
●Useful for evaluating patients with revascularization.
Spect myocardial perfusion study
Stress thallium-201 myocardial perfusion study
Radiopharmaceutical:
●
●
●For obese patients
●Used so that higher dose can be administered
●Mode of Administration(MOA) –
●Th-201 thallous chloride
●Tc-99m Sestamibi
Intravenously while the patient is physically stressed on a threadmill
Adult dose:
a. Stress study:
●Administered intravenously before rest study
b. Delayed Study:
●Administered intravenously before delayed
c. Rest Study –
●Administered intravenously before rest study
3 mCi of Th201 thallous chloride
1 mCi of Th201 thallous chloride
4 mCi of Th201 thallous chloride
Scanning in stress thallium-201 myocardial perfusion study
● Anterior planar image of the chest and heart.
●A 180 degree SPECT study. (45 degree RAO to 45 degrees LPO)
Stress Thallium-201 Myocardial Perfusion Study
Images: 2 sets
A.
B.
NOTE: During Th-201 myocardial perfusion study,
a.After the stress test
b.Several hours after the patient is rested.
the symptoms may be apparent at rest.