NM cardiology Combined

literally....everything....

What are the two methods of dynamic cardiac imaging we can perform in nuclear medicine?

first pass study

gated blood pool imaging (AKA MUGA, RVG, ERNA or RNA)

What are the indications for a First pass study?

eval of pts with:

LV dysfunction

Interventricular shunts

myocardial ischemia

MI

What are the advantages of first pass studies?

tracer activity is limited to 1 chamber at at time

background is decreased

rapidly completed

What are the disadvantages of first pass studies?

gamma cameras must be able to acquire data at 200,000 counts/sec or greater

speical multi-crystal cameras with high count rate capabilities are optimal but not widely available

• increased count rate = increased sensitivity

What is the minimum dosage for a first pass study?

10 mCi

What types of imaging would we perform for a first pass study?

Gated images

What types of Tc tracers would we use for a first pass study?

sestamibi, tetrofosmin, pentetate, pertechnetate

What tracers should we NOT use for a first pass study? (hint: think about all Tc tracers, and cardio tracers)

MAA

SC (sulfur colloid)

Tl-201

When performing a first pass exam, the volume should be greater than ____ for a good bolus

1ml

How fast should a bolus be pushed when performing a LVEF first pass study? What should follow it?

over 2-3 sec

10ml flush

How fast should a bolus be pushed when performing a RVEF first pass study? What should follow it?

over 2-3 sec

10ml flush

When performing a first-pass study, what baseline test should be performed before the injection of the tracer? Why?

baseline ECG to assess rhythm

Through which veins are we injecting for a first pass study?

in Right AC (median Basilic vein) or jugular for direct path to superior vena cava

How can we tell if its a good bolus during a first pass study?

time activity curve over superior vena cava, calculate FWHM

What is the rate of data acquisition for a first pass study?

16-30 frames/sec or 1,200 frames in 60 sec

What matrix size would we use for a first pass study?

64×64

What type of collimator would we use when performing a first pass study?

high sensitivity

When imaging a patient during a first pass study, what can be done to ensure we positioned the patient properly?

1mCI dose can be injected to check positioning or perform a transmission scan

When positioning the patient under the camera for a first pass study, _____ should be positioned at the top of the FOV, and the ____ should be within the FOV

sternal notch (at top of FOV)

xifoid (within the FOV)

How would the camera be oriented when assessing the LVEF during a first pass study?

supine or upright

LAO view

How would the camera be oriented when assessing the RVEF during a first-pass study?

RAO

How would the camera be oriented when assessing both ventricles during a first pass study?

anterior

During a first pass study, describe the sequential visualization a good bolus would give

uSuperior vena cava

uRight atrium

uRight ventricle

uPulmonary artery to lungs

uPulmonary veins

uLeft atrium

uLeft ventricle

uAorta

When interpreting a first pass study, what are we looking for?

EF

left to right shunt

right to left shunt

When interpreting a first-pass study, if a patient has a left-to-right shunt, some of the oxygenated blood returning from the lungs will _____

will go through the shunt and circulate back to the lungs instead of the body

When interpreting a first-pass study, if a patient has a right-to-left shunt, some of the deoxygenated blood returning from the body will _____ instead of

go through the shunt and be sent out to the body

On a time activity curve, do the high points represent diastole or systole?

diastole

On a time activity curve, do the low points represent diastole or systole?

systole

How would a left to right shunt be interpreted on a first pass study?

Rapid recirculation of tracer to lungs once it enters the left side of the heart.

How would a right-to-left shunt be interpreted on a first pass study?

Appearance of bolus in left side of the heart and aorta before the appearance of lung activity

When interpreting a time activity curve for a Left to right shunt, A represents _______ and B represents _______

normal flow (1 peak)

left to right shunt (2 peeks)

In Gated blood pool imaging, how is data collected?

over many cardiac cycles using ECG gating

Gated equilibrium is another name for _______

Gated blood pool imaging

gated cardiac blood pool study is another name for a _______ procedure

Gated blood pool imaging

equilibrium radionuclide angiography (ERNA) is another name for a _______ procedure

Gated blood pool imaging

radionuclide ventriculography (RVG) is another name for a _______ procedure

Gated blood pool imaging

multiple gated acquisition study (MUGA) is another name for a _______ procedure

Gated blood pool imaging

What are the indications for Gated blood pool imaging?

• Assessment of cardiac function in chemotherapy patients

• Quantification of ejection fraction (LVEF, RVEF)

• Detection or assessment of CAD

• MI

• Estimation of wall motion abnormalities

• Eval of function of pts with valvular disease

• follow-up of medical/surgical therapy

Why would we perform a Gated blood pool imaging instead of a full stress test?

Its own exam bc pts don’t need stress test, just ejection fraction

What is the patient prep for a gated blood pool imaging?

none

What is the most commonly used radiopharmaceutical for a.gated blood pool imaging?

Tc-99m labeled RBC’s

What are the 3 ways we can label RBC’s?

in vitro

modified

in vivo

When using the In Vivo labeling method, blood is labeled ________

inside the body

When using the In Vitro labeling method, blood is labeled ________

outside the body, using an Ultratag kit

The advantage(s) of using an In Vivo/In Vitro method of blood labeling is:

high efficiency (~95%)

absence of blood manipulation

The in Vivo method of blood labeling has a ____% labeling efficiency

60-90%

Describe the steps taken when labeling blood using the In Vivo method

—Inject stannous ion

—Wait 20-30 min

—Inject ^99mTc-Pertechnetate

—Free ^99mTc is secreted through gastric mucosa and kidneys

—Not able to see bleed in stomach, small bowel, and/or the colon

What are the disadvantages of using the In Vivo method?

Labeling constancies variable (60-90%)

Free ^99mTc is secreted through gastric mucosa and kidneys

Not able to see bleed in stomach, small bowel, and/or the colon

What is the advantage of using the in Vivo method?

Convenient and easy

What blood labeling methods use Stannous Pyrophosphate?

in Vivo

modified in vivo/in vitro

What is cold Stannous Pyrophosphate used for in blood labeling?

to pretreat RBC’s for labeling

What is the optimal dose of Stannous Pyrophosphate when labeling RBC’s?

0.5-1.0mg

What if too little of Stannous Pyrophosphate is used when labeling RBC’s?

dose of Tc will not properly label RBCs

What will happen if too much of Stannous Pyrophosphate is used when labeling RBC’s?

some of tin will circulate freely and tag to Tc outside of RBC’s

What wil happen to image quality if too much or too little of the Stannous Pyrophosphate is administered when labeling RBC’s?

results in increased background as a result of free Tc

Describe the steps taken when labeling blood using the In Vivo/In Vitro method

IV injection of stanous ion

Blood sample is collected into a syringe containing ^99mTc-Pertechnetate and anticoagulant

Re-injected

Describe the steps taken when labeling blood using the In Vitro method:

1-3ml of blood withdrawn into syringe containing anticoagulant

let sit for 5 min

Add sodium hypochlorite and acid-citrate-dextrose (ACD)

• To oxidize the extracellular stannous ion

Add ^99mTc-Pertechnetate (diffuses into the RBC where it is reduced and trapped)

Wait 20 minutes (no longer than 60min) and inject

T/F: when using the In vitro method to label blood, once the tracer has been added, we can use a sample that has been sitting for more than 60min

false

T/F: When using the In vitro method to label blood, we can inject imedietly after adding the Tc-99m Pertechnetate

false

T/F: When using the In vitro method to label blood, we have to wait at least 60 minutes after the Tc-99m Pertechnetate has been added before injecting.

false

T/F: When using the In vitro method to label blood, once the Tc-99m Pertechnetate has been added, we have to wait at least 20 minutes, but no more than 60 min before injecting

true

What is the advantage of using an In Vitro method for labeling blood?

high labeling efficiency, superior image quality

Describe the procedure for a gated equilibrium study.

In Vivo, In Vitro, or modified In Vivo/In Vitro labeling of RBC’s w/ Tc-99m

3 gated planar images obtained

• Anterior

• LAO

• Lft Lateraral

What views are obtained when performing a gated equilibrium study?

planars:

• Anterior

• LAO

• Lft Lateraral

T/F: When performing a MUGA (multiple gated acquisition study), an ECG rhythm strip should be obtained and reviewed before injection

True

Why should a ECG rhythm strip be obtained and reviewed before injection during a MUGA procedure?

Rapid atrial fibrillation or frequent PVCs (premature ventricular contractions) are contraindications to study

One cardiac cycle can be divided into intervals of ___

8 (16, 24. or 32) frames

What triggers gating in cardiac images?

R wave

During a gated study, 24 frames per cardiac cycle are obtained.  If a patient’s heart rate is 65 bpm, the length of time per  frame is:

a. 38 msec

b. 3.8 msec

c. 41 msec

d.4.1 msec

b. 38 msec

In a gated study, if the patient’s heart rate is 65 bpm, and 24 frames per cardiac cycle was obtained, How do you calculate the length of time per frame in msec?

60 sec/min divided by 65 beats/min = 0.92 sec/beat

divide by 24 frames = 0.038 sec X 1,000 = 38 msec

Which view provides the best separation between the L. and R. ventricles during a gated study?

LAO

How should a technologist reposition the camera if trying to separate the atria from the ventricles in a gated study?

apply a 5-10 degree caudal tilt

From the best LAO view, the anterior and lateral views are obtained ± ____ degrees.

45 degrees

how would the camera be positioned during a gated study if trying to visualize the Right ventricle?

20 degrees anterior (5 degrees of caudal tilt)

Based on this image, which is systole and which is diastole?

1st row diastole, 2^nd row systole

During a gated study, in what views would we potentially apply a caudal tilt?

only for LAO or RAO

When performing a gated study, can we use a caudal tilt for anterior or lateral views?

no

If we apply a caudal tilt to the camera, we are tilting the camera towards the _______

Pelvis (caudus)

How does a caudal tilt affect images?

used to elongate ventricles

When performing a gated blood pool imaging, are we acquiring rest or stress images?

rest

During a gated equilibrium study, what energy window are we using?

20% window centered at 140keV

What type of collimator are we using during a gated equilibrium study?

LEHR

What is the R-R acceptance window in a gated equilibrium study?

10-15%

What matrix size are we using for a gated equilibrium study?

64×64×16

When taking images for a gated equilibrium study, we have to acquire a minimum of ________ counts per frame, or about ___ to ___ minutes per view

250,000 counts

~5-10 min

T/F: If the heart rate is irregular, imaging during a gated equilibrium study will take longer

True

How is a gated equilibrium study data reconstruted?

added together to form a representative cardiac cycle

simulates the heart beating

Qualitative anaysis of a gated equilibrium study can be used to assess:

cardiac chamber size

overall biventricuar function

regional wall motion

extra cardiac abnormalities such as aneurysms

What does Akinesis mean?

absence of wall motion

What does Hypokinesis mean?

decreased wall motion

What is Dyskinesis?

outward bulge during systole

What is stroke volume?

volume of blood ejected by either ventricle during systole

What is the cardiac output?

volume of blood that heart pumps per minute

CO = SV at heart rate

What is the ejection fraction?

% of blood ejected from ventricles during each contraction

What does qualitative analysis of a gated equilibrium study used to analyze?

LVEF

How are images processed for quantitative analysis during a gated equilibrium study?

ROI’s drawn on LV at diastole and systole

Background ROI selected about 3-6 o’clock from LV

• ROI can be manually drawn or generated by computer

In images taken at end diastole, the ventricle is _____, and the counts obtained would be _______.

relaxing

highest

In images taken at end systole, the ventricle is _____, and the counts obtained would be _______.

contracted

lowest

How do you calculate Ejection fraction?

[(net diastolic counts - net systolic counts) / net diastolic counts] X 100

Calculate the Ejection fraction if ED (end diastolic counts) are 90,400 and ES (end systolic counts) are 40,000

(90,000 - 40,000) / 90,400 = 0.557

0.557 X 100 = 55.7%