Nuclear med Flashcards
The Nuclear Medicine Technologist
Certificate
Associate Degree Program- moved to bachelor
Bachelor’s Degree Program
Last year is Nuclear Med school
Didactic and Clinical
Post-baccalaureate may participate as certificate in that year’s training program if proper pre-requisites
National Boards
Earn CNMT by NMTCB
Earn RT(N) by ARRT- Registered Technologist, N for Nuclear med
Nuclear Medicine
Advanced Associate
Midlevel provider for the Nuclear Medicine Department: Nuclear Medicine Advanced Associate (NMAA)
Masters Degree
Department of Nuclear Medicine
May see subdivisions or different organization:
Nuclear Cardiology
Nuclear Oncology
therapy
imaging with tumor markers
Therananostics
PET imaging
Principles of Nuclear Medicine
Radiopharmaceuticals
contraindications
Basically none known except for allergy
Extremely rare except iodine agents
Adverse Drug Reactions (ADR)-rare
Erythema, edema, fever
Radiation Exposure
Likened to a pair of CXR films
One dose for unlimited films
Gamma rays emitted in all directions
Do not order test without reason
Safety Measures (3)
Time
Distance
Shielding
Image Acquisition
Gamma camera
Planar imaging
Single or multi headed
SPECT 3D imaging
Single or multi headed
Pb (lead) collimator
Parallel apertures allow gamma rays
Gamma rays hit scintillation crystal (NaI)
Crystal converts gamma energy to electronic signal (or light)
Cumulative “photo”
Newer technology bypasses traditional “scintillation” steps
Resolution
Ability to distinguish 2 different points as such
High resolution scans require
high resolution collimator
longer acquisition time
Sensitivity
Ability to pick up the gamma signal
High sensitivity scans
low resolution /high sensitive collimator
shorter acquisition time
Artifact
affecting apparent distribution (uptake)
Attenuation
decrease in intensity gamma ray energy
Scatter
gamma ray changes its path
Image Processing
Regions of interest (ROIs)
Often placed by technologist
Reconstruction
SPECT always requires
Need time to reconstruct/process
Above manipulations can introduce artifacts if done incorrectly
QC/A
Laborious quality assurance/control
Cameras
Including daily flood fields
Isotope generator
Radiopharmaceuticals
If problem here, artifact
Image Interpretation
Read by Nuclear Medicine Physician
May or may not be general radiologist
Language of Nuclear Medicine
Hot or cold spots
Increased or decreased uptake
Ordering Studies
If more than one nuc med study, chronological order very important!!!!
Isotopes need time to decay/be eliminated
Other radiological tests requiring contrast agents will also affect Nuc Med test
Eg barium, IV contrast
Artifacts introduced
Stat or On Call Scans*
Scans marked with * show those that may be ordered emergently
Common Studies
Bone scans
Nuclear cardiology
MUGA (multi-gated acquisition)- ECG gate
Exercise MUGA
Stress Thallium or Cardiolite
Liver/spleen scans
Largely replaced by ultrasound
Hepatobiliary scan *
Thyroid Scan/Update
SPECT Brain
V/P or V/Q scan *
VCUG
Renal
Studies requiring blood flow images *
Testicular scan (replaced by US/doppler)
GI Bleed
Bone Scan
Planar or SPECT bone
R/o mets, Paget’s (hot spots)
Avascular necrosis (e.g. femoral neck; cold)
99mTc MDP IV
Image 4 hours later
Look for symmetry!
Bladder and Kidneys seen
Radiopharmaceutial cleared by kidneys
Darker is increased uptake
Thickness of bone
Closeness to camera
Or hypermetabolic
bone scan orientation
Right Anterior Left
Left Posterior Right
Cephalad is top of film
Caudal is bottom
**BONE METS **
Note radioactive marker for “R”
Mets
Urinary bladder
L wrist area injection site
Knees most likely arthritic (not usual place for mets)
peds bone scan
Growth plates!
Childern are given med to “block” thyroid
Increased uptake L fibula
Probably tumor
3 Phase Bone Scan
Phase 1: Blood Flow
Phase 2: Blood Pool
Phase 3: Bone Imaging
R/o stress fx
R/o osteomyelitis
FUO/Infection
Nuclear Cardiology
Echos used now but…
MUGA- Left Ventricle study
Multi gated acquisition
EKG gated
Images Blood Pool; typically 3 view
Cardiac wall motion
Hypokinesia
Akinesia
Dyskinesia
Ejection fraction
Normal 45-65% (different values/ dif books)
Calculated
MUGA
99mTc PYP labeled RBCs
20 mCi
IV injection of PYP (pyrophosphate) tags to RBCs
IV injection 20 min later of 99mTcO4- tags to PYP
Or ultratag kit - 1 bottle with all reagents
Septum appears “cold”
Anterior
“Best septal” or LAO (left anterior oblique)-Used to calculate EF
L lateral images
Series of 3 different orientation “cine” pictures
Additive collection of radioactive particles over and over again to make pictures for movi
Abnormal MUGA
“Flatter” graph
Decreased EF
End Diastole and End Systole pictures
Not much change in size
This is LAO or best septal view
When MUGA vs Echo?
Echos for structural abnomality
chemo ?- functional?
First Pass MUGA
One chance only for Right Ventricle study
Left heart will “cover” right heart after “first pass” in circulation
RV
Normal RVEF=45-55%
Should be less than LFEF (10% ish)
Utilizes butterfly or other IV access
pertechnetate bolus w pt under camera
Blood flow imaged
Exercise MUGA
Modified bicycle table or other device-Increase work load (can be done w Echo)
Normally see LVEF increase with exercise
Wall motion changes
(Similar to stress echo)
Can be done with pharmaceuticals to mimic “stress”- EG persantine
Nuclear Cardiology Stress Test
r/o CAD w SPECT
Stress Component
Image after exercise protocol completed
LV seen
Rest Component
Either several hours after exercise (using Thallium- a K+ analog) or first with Cardiolite (pertechnetate derivative)
May see RV faintly (Tl)
Tl 201 (or TCO4- agents)
Same views as MUGA
Anterior
LAO (see donut w/o “bite”)
L Lateral
Liver Spleen Scan
Less common due to US
99mTc Sulfur Colloid 4 mCi
Taken up by macrophage Kuppfer Cells of RES thus, does NOT image hepatocytes!
Homogenous uptake normal
Hepatobiliary Scanning
r/o biliary obstruction
Aka HIDA or PIPIDA, DISIDA
(depends on institution’s pharmaceutical choice)
Choletch/mebrofenin
Excreted through biliary system
99mTc HIDA 4-8 mCi dose
Can be adjusted for abnormal LFTs
Should visualize GB by 45 min to hour
Should visualize small intestine (by 2 hr)
EF of Gallbladder could be calculated after dose of med
GI bleed * /Meckel’s diverticulum
RBC labelling like MUGA scan
Labeled RBCs
Figure of bleed distal descending colon
Gastric emptying
Sulfur colloid scrambled eggs for solid
Sulfur colloid in liquid
Can follow GI transit time
Gastroparesis
E.g. Diabetic
Thyroid Scan
Pertechnetate
Iodine isotopes
Thyroid uptake
HOT vs COLD nodules
Cold may be malignant
“could also be a cyst”
Ultrasound can help
SPECT Brain
Cerebrovascular Disease
Ischemia CVA identified earlier than CT
Brain death
Dementia evaluation
PET brain scans “higher tech”
Views:
Transverse (superior to inferior)
Coronal (ant to post)
Sagittal (L to R)
Again, symmetry is key
SPECT Brain investigations
DAT (Dementia of Alzheimer’s Type)
Epilepsy
Schizophrenia
Ventilation Perfusion Scan
(V/P) or V/Q
3 phases
R/o PE (pulmonary embolism)
Ventilation phase
Xe 133 gas, Tc99m DTPA aerosol
Inspiratory phase
Equilibrium phase
Washout phase
VP Scan
Perfusion phase
Tc 99m MAA (microaggregated albumin)
Blocks small capillaries
Ventilation Perfusion “mismatch” for PE
Ventilation normal
Perfusion absent area(s)
If perfusion normal, vent not performed w perfusion first technique
VP Other Diagnostic Findings
COPD
longer ventilation “washout” phase
air trapping
Area could be infarcted
No vent
No perf
Renal
Different agents
Renal parenchyma
Renal tubules
Voiding Cystourethrogram
TcO4 saline via bladder
Filling phase
Voiding phase
Measures bladder volume
Looks for reflux
Testicular Scan
US w doppler has largely replaced
Acute scrotal pain
Chronic scrotal pain
Injury
Mass
Torsion
Note: US usually used
IV Tc blood flow, pool studies
Nuclear Medicine Therapies
Thyroid ablation
High dose oral radioactive iodine
Nuclear Oncology
Theranostics- molecular imaging/treatment
(aka theragnostic) alpha or beta emitters
Palliative or curative therapy goals
E.g. mets, but not cure primary site
Nuclear Oncology
Bone mets radiotherapy
Palliative
IV strontium 89
Scintomammography
R breast nodule
Nuclear Medicine take homes
“Functional” imaging- images not “clear”
Hot vs. Cold (increased vs. decreased uptake)
Order of imaging done very important!
Usually no Allergies/ADRs
Radioisotope administration
usually IV
as many films as necessary from the dose
“safe” doses
