Clinical Protocols (Non-Therapy) Flashcards
What is the mechanism of physiological uptake in a Lung Ventilation scan?
The micro-aerosol particles are small enough to reach the DISTAL TRACHEOBRONCHIAL TREE and reflect REGIONAL VENTILATION
NB: Aerosols are suspensions of very fine particles that are deposited in the ALVEOLI
With regards to LUNG VENTILATION; can you tell me:
1. What radionuclide is used?
2. What pharmaceutical is used?
3. What is the LDRL in NHST for the examination?
- Technetium-99m
- DTPA (Pentate aerosol)
- 40 MBq (800 is dispensed, but 40 makes it to the lungs)
What is the clinical need for a LUNG VENTILATION scan?
How is this affected if the patient is pregnant?
Lung ventilation shows the SHAPE of the lungs, and establishes if PERFUSION DEFECTS match.
For pregnant patients: Only acquire if the perfusion image is abnormal
With regards to LUNG VENTILATION; can you tell me what camera acquisition settings are typically used in NHST?
1. Collimator
2. Matrix Size
3. Energy Window
- LEGP
- 128x128
- γ-emission: 140.5 keV photopeak;
Window settings at 141 keV with 20 keV width
What does MUGA stand for?
MUlti Gated Acquisition.
Used in blood pool imaging
What is the clinical need for a MUGA scan?
It is a common study for patients receiving CARDIOTOXIC CHEMOTHERAPY
Would also accept any of:
1. Acute Myocardial Infarction (AMI)
2. Coronary Artery Disease (CAD)
3. Assessment of drug therapy
4. Pulmonary disease
With regards to a MUGA scan; can you tell me:
1. What radionuclide is used?
2. What pharmaceutical is used?
3. What is the LDRL in NHST for the examination?
- Technetium-99m
- Tc-99m labelled PERECHNATE
Also pre-administration of stannous ions 30
mins before radiopharmaceutical - 800 MBq
What is the mechanism of physiological uptake in a MUGA scan?
Tc-99m must be in an OXIDATED state to cross the ERYTHROCYTE MEMBRANE
BUT only tc-99m that has been REDUCED into a lower state will bind firmly to HAEMOGLOBIN
Stannis is used as the REDUCING AGENT for Tc-99m
Combination of both with delayed phase allows for diffusion of stannous into the blood pool so that Tc-99m tracer binds to blood cells
How would you process a MUGA scan?
The ECG time gated images are analysed by applying ROIs around the LEFT VENTRICLE of the heart.
The measured counts during DYASTOLE (EDV) & SYSTOLE (ESV) are used to calculated the LEFT VENTRICULAR EJECTION FRACTION (LVEF)
Normal LVEF @ Baseline is > 50%
Therapy is stopped if LVEF decreases by > 10 from baseline or if LVEF falls < 50%
If < 30% Therapy would not begin
With regards to a MUGA scan; can you tell me what camera acquisition settings are typically used in NHST?
1. Collimator
2. Matrix Size
3. Energy Window
- LEGP
- 64x64, 24 bins (dynamic ECG gated) with the heart filling at least 50 % of the FOV
- γ-emission: 140.5 keV photopeak;
Window settings at 141 keV with 20 keV width
What is the clinical need for an MPS scan?
An MPS study looks at how well blood flows THROUGH your HEART MUSCLE
May be referred for indication of:
1. Chest pain
2. Coronary artery disease (CAD)
3. To look for HEART MUSCLE DAMAGE after a HEART ATTACK
With regards to an MPS scan; can you tell me:
1. What radionuclide is used?
2. What pharmaceutical is used?
3. What is the LDRL in NHST for the examination?
- Tc-99m
- TETROFOSMIN (for binding to RN); if stress phase + RAGADENSON as a pharmaceutical stressing agent
- 800 MBq per Stress/Rest
- If BMI > 40, ARSAC approval for 1200 MBq
per stress/rest in NHST (Seeking to change)
- If BMI > 40, ARSAC approval for 1200 MBq
What is the mechanism of physiological uptake in an MPS scan?
Tc-99m TETROFOSMIN is LIPID SOLUBLE and so diffuses from the blood into the MYOCARDIAL CELL.
It is RETAINED INTRACELLULARLY in the region of the MITOCHONDRIA because of its NEGATIVE TRANSMEMBRANE POTENTIAL
The radiopharmaceutical remains FIXED WITHIN the MYOCARDIUM
With regards to an MPS scan; can you tell me what camera acquisition settings are typically used in NHST?
1. Collimator
2. Matrix Size
3. Energy Window
- LEHR
- 64x64 (512x512 CT(60)) - SPECT acquisition imaging
- Since it is SPECT imaging, requires 2 acquisition windows, for photopeak and for scatter window:
Emission Window:
γ-emission: 140.5 keV photopeak;
Window settings at 141 keV with 20 keV width
Scatter Window:
Window settings at 120 keV with 10 keV width
How would you process an MPS scan?
Visual inspection of the three main views of the heart. Images are registered to CT to provide attenuation correction.
The three analysis views:
1. Short Axis - O
2. Vertical Long Axis - U
3. Horizontal Long Axis - ⸧
What is the clinical need of Lymphoscintigraphy?
Assesses the DRAINAGE of the LYMPHATIC SYSTEM - Sentinel Lymph node drainage
- Referred for indications of OEDEMA (Protein-rich fluid build up/swelling)
With regards to a Lymphoscintigraphy; can you tell me:
1. What radionuclide is used?
2. What pharmaceutical is used?
3. What is the LDRL in NHST for the examination?
- Tc-99m
- Nanocolloidal Human Serum Albumin (NHSA)
- 20 MBq/Limb
What is the mechanism of physiological uptake in Lymphoscintigraphy?
COLLOIDAL AGENTS are used as these particles enter LYMPHATIC CHANNELS and MIGRATE to LYMPH NODES where they are RETAINED by MACROPHAGES
The radiotracer is inkected INTRADERMALLY, usually between the fingers or toes of each limb.
With regards to Lymphoscintigraphy; can you tell me what camera acquisition settings are typically used in NHST?
1. Collimator
2. Matrix Size
3. Energy Window
- LEGP
- 526x1024
- γ-emission: 140.5 keV photopeak;
Window settings at 141 keV with 20 keV width
Can you tell me what DaTscan means?
DaT stands for dopamine active transporter.
Dopamine is a chemical which is important in areas of the brain that help control movement
What is the clinical need of a DaTSCAN?
It is used to detect the loss of nerve cells in an area of the brain called the STRIATUM, specifically the cells that release dopamine, a chemical messenger.
Referred for indications of:
1. Parkinson’s Disease
2. Lewly body dementia
With regards to a DaTSCAN; can you tell me:
1. What radionuclide is used?
2. What pharmaceutical is used?
3. What is the LDRL in NHST for the examination?
- I-123
- IOFLUPANE
- 185 MBq