CPR imaging Flashcards
what is the most sensitive test for a pt presenting with sudden onset tachycardia, chest pain and dyspnea?
CT- although the “gold standard” for a pulmonary emboli is angiography
what is a good imaging technique to check for horse shoe kidney, associated with trisomies?
post natal ultrasound (usually done soon after birth), do not use contrast because it could exacerbate a renal issue.
what are the indications for echocardiogram (dx cardio US)?
evaluate congenital heart defects changes in heart size pumping strength (ejection fraction and CO) damage to heart muscle valvular dysfunction presence of pericardial effusion guidance of pericardiocentesis
what are the pros of transthoracic echocardiograms (TTEs)?
usually first-line cardiac imaging modality because its widely available, non invasive, no radiation risk
what are the risks of echocardiograms?
during stress echo, exercise may cause temporary dysrhythmia and rarely heart attacks
echocardiograms create pictures of what?
hearts chambers, valves , walls, and blood vessels
doppler echo creates what?
colorized image to assess speed and direction of blood flow
what are the pros of using doppler echo?
find blood flow abnormalities in cardiac arteries missed by traditional ultrasound
what are the indications for continuous doppler echo?
measures high velocities: pulm. HTN and aortic stenosis
what are the indications for pulsed doppler?
assess low velocities: mitral/tricuspid inflow, atrial appendage flow, ventricular outflows
what are the indications for color flow doppler?
assess regurgitant flows
intracardiac shunts (ASD, VSD)
assess pulmonary vein flow
what are the risks for doppler echo?
none
what is the most commonly used transducer position and why?
left lateral decubitus - left-handed scanning is more ergonomic and lower risk of sonographer orthopedic injuries.
what is the most common congenital cardiac anomaly?
ventricular septal defect (VSD)
In VSDs what are the effects of small and large lesions?
small lesions may be asymptomatic with harsh pansystolic (plateau) murmurs
large lesions may cause signs of heart failure
what is the best method for visualizing VSDs?
echo- allows direct visualization of the septal defect with no radiation exposure
CTA with ECG- gating allows direct visualization but with risk of radiation exposure
coarctation of the aorta
aortic narrowing near insertion of ductus arteriosus
what are the signs of coarctation of the aorta?
HTN in UE, weak pulses in LE (brachial-femoral delay)
what is the imaging of choice for coarctation of the aorta?
echo ESTABLISHES the dx and severity in most cases
CTA can be complimentary imaging tool important prior to intervention
what is the MUGA Scan?
multiple gated acquisition scan; assesses cardiac pumping function and measures ejection fraction via radiotracer that causes gamma ray emissions that are detected to create an image
what are the indications for MUGA?
detect for causes of reduced ejection fraction:
heart failure, damaged myocardium from MI or cardiomyopathy
can help answer why a patient has angina, dizziness, dyspnea or fatigue
pros of MUGA
accurate, reproducible, non invasive
- measured EF is more precise vs other cardiac tests
- can localize abnormally functioning myocardium to find blocked coronary arteries
what are the risks of MUGA?
low level of radioactivity unknown to cause any short/long-term damage, allergic reaction to tracer
what are the contraindications of MUGA?
renal disease, pregnant or breast-feeding women
what is the gold standard for Coronary artery disease (CAD)?
coronary angiography
what are the indications for coronary angiography?
CAD, acute MI, valvular disease, CHF
used prior to percutaneous coronary intervention or non-cardiac surgery
what are the contraindications for coronary angiography?
renal failure, contrast medium allergy (shellfish?), coagulopathy, uncontrolled HTN, decompensated HF, GI hemorrhage, pregnancy, active infection
what are the cons of coronary angiography?
expensive, procedural risks
what are the cons of coronary angiography?
expensive, procedural risks
what is a CTA?
computed tomography angiography: CT scan with injection of contrast to produce pictures of blood vessels and organs such as the heart, brain, kidneys, liver, etc.
what are the indications for a CTA?
locate aneurysms, blockages, clots, vascular malformation, stenosis, injury, vessel rupture/dissection, pulmonary embolism.
what are the risks for CTA?
minimal radiation exposure, allergic reaction to contrast, tissue damage via contrast leakage
Pros of CTA
quick, noninvasive, may eliminate need for surgery, allows surgeries to be performed more accurately, cheaper than catheter angiography
what is the most posterior part of the heart?
the left atrium
what can happen with Left Atrium enlargement?
(e.g. mitral stenosis) can lead to compression of the esophagus causing dysphagia and or left recurrent laryngeal nerve causing hoarseness.
what is the most anterior part of the heart and what is it most susceptible to ?
right ventricle- most commonly injured in trauma
aortic dissection
longitudinal intimal tear forming a false lumen; associated with MARFANS and pts with chronic HTN
what are the signs of aortic dissection?
sudden onset tearing chest pain radiating to the back, unequal BP in arms, diminished or unequal BP peripheral pulses, new diastolic murmur from aortic regurgitation
what is the imaging of choice for aortic dissection and what is a special finding?
CXR shows mediastinal widening. CTA is CHOICE of imaging, because it can diagnose/classify the dissection and evaluate for distal complications.
There flap and false lumen separates ascending and descending aorta in a
CT is the imaging of choice for what?
aortic dissection, aneurysms (thoracic aortic aneurysms), blockages, blood clots, vascular malformations, stenosis, injury, vessel rupture/dissection, pulmonary embolism (use chest CT w/ contrast although pulmonary angiography is the gold standard)
complimentary for coarctation of the aorta
thoracic aortic aneurysm
associated with cystic medial degeneration seen in Marfans
Aortic root dilation can lead to aortic regurgitation and associated symptoms
what are the signs for thoracic aortic aneurysm?
mass effect on airway and esophagus
what is the imaging of choice for thoracic aortic aneurysm?
CTA
what is something to note about the difference on CT of aortic aneurysm vs aortic dissection?
there is no “flap” and false lumen separating ascending and descending aorta in aortic aneurysms.
describe chest x-rays (CXRs)?
the most commonly used modality is PA- posterior anterior film: patient faces film plate with x-ray tube behind them. Pt is standing.
another modality is anterior posterior (AP): pts back against the film plate with x-ray machine in front, pt lies supine
what is a note of importance for AP modality in CXR?
In AP view, the mediastinum appears widened due to AP magnification. As a rule of thumb, you should never consider the heart size to be enlarged (cardiomegaly) if the projection used is AP.
How to tell if its PA or AP modality in CXR?
usually will be labeled
if unlabeled assume - PA
if unsure look at medial edges of each scapula
in PA view the patient’s arms are around the detector plate or on their hips, this pushes the scapulae laterally and results in NO overlapping of the lungs and imaging.
what is the cardiothoracic ratio for AP/PA projections in CXR?
AP: (cloudier) Cardio thoracic ratio ~50%
PA: (more defined and contrasted), cardio thoracic ratio under 50%
what are the differential diagnoses for cardiolmegaly?
CHF, HTN with left ventricular hypertrophy, valvular disease, cardiomyopathies, pulmonary disease with right ventricular hypertrophy, myocarditis, normal athletic heart.
what is the imaging of choice for cardiomegaly?
CXR is sufficient to Dx cardiomegaly but use PA VIEW!!!
other imaging can be done to narrow down differential.
what are the differential diagnoses for widened mediastinum?
anthrax, aortic dissection, thoracic aortic aneurysm, pneumomediastinum, mediastinal mass.
what is the imaging of choice for widened mediastinum?
CXR is enough; others can just narrow Ddx
what is CXR best used for?
PA- cardiomegaly (ventricular hypertrophies, myocarditis, normal athletic heart)
PA/AP/ lateral for widened mediastinum due to aneurysms, aortic dissections, pneumomediastinum, mediastinal masses.
pulmonary/respiratory complaints - SOB, dyspnea, angina, injury, chronic cough, lung abscess with air-fluid level
which imaging modalities can you not use while pregnant?
MUGA scan, CXR, and coronary/pulmonary angiography
can have CT in emergency only!
what is the mechanism for CXR?
beams of ionizing radiation sent through the chest to produce images of the heart, lungs, airways, blood vessels, and bones of the spine and chest.
what are the indications of CXR?
initial imaging test to assess dyspnea, chronic cough, chest pain, and injury
evaluate for pneumonia, COPD, rib/collarbone fx, TB, pneumothorax, pleural effusion, interstitial lung dz.
explain “ABCDEF” for CXR
Airways, bones, circulation/cardiac silhouette, diaphragm, expanded lungs, foreign objects (mnemonic for evaluating structures on CXR)
what are the benefits for CXR?
fast widely available, cheap, usually no side effects
what are the risks of CXR?
low risk of cancer from excess radiation exposure, avoid in pregnant women due to risk of radiation injury to fetus
what is the most sensitive sign on CXR for hyperinflation of the lungs?
flattened diaphragm usually due to emphysema (COPD)
how much should the dome of each hemidiaphragm rise?
at least 1.5 cm above a line connecting the costophrenic angle posteriorly and sternophrenic angle anteriorly
barrel chest
increased AP diameter of chest wall 1:1 ratio
COPD
what imaging modality should you use for barrel chest?
CXR
what does air-fluid level on CXR indicate?
Air-fluid level level on CXR indicates presence of cavitation due to lung abscess (collection of pus within parenchyma)
what are the causes of lung ascess with air fluid level
infection or by aspiration of oropharyngeal contents
most common risk factor: alcoholism
what are the signs of Lung abscesses with air fluid level
fatigue, night sweats, fever, weight loss, productive cough, chest pain, possibly bad breath
what is the imaging of choice for lung abscesses with air fluid level?
CXR
define pleural effusion
abnormal accumulation of fluid in pleural space
what are the signs of pleural effusion?
dyspnea, pleural chest pain, possibly cough
what are the physical exam findings of pleural effusion?
dullness to percussion, decreased breath sounds
what are the findings of pleural effusion on CXR?
blunting of the posterior costo-phrenic angle on lateral CXR
what is the pulmonary meniscus sign?
meniscus-shaped upper border of pleural effusion/ found on surface of fluid.
moderate sized pleural effusion obscures the diaphragm
meniscus is due to surface tension between 2 different fluids in pleural cavity (normal serous fluid and pleural effusion)
where can a pulmonary meniscus be seen on CXR?
PA: accumulates in costophrenic angles
Lateral: substernal region
Ventilation perfusion (VQ) scan mechanism
nuclear medicine scan that uses inhaled and injected radioactive material to evaluate ventilation and perfusion
detects regional differences in lung blood flow and air distribution
what are the indications for VQ scan?
primarily used to diagnose or rule out pulmonary embolism
what are the pros of using a VQ scan?
readily available, minimal risk, accurate in detecting blood clots
what are the risks of using a VQ scan?
injection pain, injection site bruise, radioisotope allergy, small amount of radiation exposure, not recommended if pregnant or breast feeding.
what are the different types of emboli
fat, air, amniotic fluid, thrombus, bacterial, tumor
define Virchow’s triad
hypercoagulability, stasis of blood flow, endothelial injury
risk factors for pulmonary embolisms- thrombosis
what are the signs of pulmonary embolisms
sudden onset dyspnea, pleuritic chest pain, tachypnea, tachycardia, low grade fever, cough
what is the assessment plan for pulmonary embolisms?
initially assess with D-dimer, if high continue to imaging
Chest CT w/ contrast is modality of choice in stable patients with suspected PE because its noninvasive and more available than V/Q scan
may use V/Q if pt has normal CXR
pulmonary angiography is “gold standard” to Dx PE but very expensive
what is the mechanism for CT?
computerized x-ray imaging that sends narrow x-ray beams toward patient as it rotates around the body producing signals processed via the computer to create cross-sectional images of soft-tissue, organs, bones and blood vessels
what are the indications for contrast enhanced CT:
oral contrast used for bowel opacification in abdominal and pelvic CTs
IV contrast used for opacification of vascular structures and solid abdominal pelvic organs
intrathecal contrast used for spinal diseases and CSF leaks
what are the pulmonary indications for CT?
pulmonary nodule screening, lung cancer, bronchiectasis, interstitial lung disease (if CXR raises suspition)
what are the pros of using CT - pulmonary indications?
low-dose radiation CT is superior in lung cancer screenings because it is more sensitive then CXR with less radiation exposure vs. standard chest CT
what imaging technique is best used for lung cancer screenings?
low-dose radiation CT» more sensitive than CXR
which ribs are fractured most often and what are findings on imaging?
ribs 4-10 are most often fractured and hematomas can be seen at site of Fx.
what is the most sensitive imaging used for fractured ribs?
may not see fracture on CXR, CT is most sensitive
CXR taken after to assess for possible pneumothorax
what is the most common imaging modality for PTs with renal disease or Urinary tract obstruction?
renal US
what are the indications for renal US?
renal disease/failure (up-to-date), urinary tract obstruction,, congenital anomalies, differentiating renal cyst vs. tumor, polycystic kidney disease, renal artery stenosis, hydronephrosis, monitoring irreversible kidney disease
renal ct- better for detecting stones and masses
what is Doppler US used for?
evaluate renal vascular flow
what are the pros of using renal US?
no risk of radiation or contrast, easy to use, and widely available
what are the cons of using renal US?
less sensitive for urinary obstructions in lower pelvis; cannot exclude small, non-obstructing stones
describe a horseshoe kidney?
congenital anomaly caused by abnormal migration of the kidneys from the pelvis to their dorso-lumbar position.
inferior poles of both kidney’s fuse and get trapped under the IMA
what are the signs of a horseshoe kidney?
kidney functions normally but it is highly associated with hydronephrosis and increased risk of renal cancer.
post-natal US used to confirm diagnosis
what can be seen on the renal US, on a pt presenting with hydronephrosis?
the major and minor calyces, renal pelvis, and proximal ureters are dilated.
what is the modality of choice to dx acute urinary retention?
bladder US
what are the signs of acute urinary retention?
inability to pass urine, lower abdominal pain, possibly restlessness, acute change of mental status in the elderly.
what are the pros of using bladder US?
low risk of infection, more comfortable, and cheaper vs urethral catheterization.
what are the indications for a renal CT scan?
often provides complementary info to renal US
evaluate complex renal cysts/masses detected by US
confirm/localize suspected ureteral obstruction not seen on US
stage renal tumors
dx renal vein thrombosis
evaluate pathologies of renal A. (fibromuscular displasia)
what is the gold standard to dx kidney stones?
non-contrast low radiation CT of urinary tract is gold standard for dx kidney stones, because it can detect small stones not seen on US or X-ray
more sensitive in detecting renal masses vs. US
what are the risks of renal CT?
contrast can be nephrotoxic therefore caution when using in Pts with renal disease, radiation exposure
what are the signs of nephrolithiasis?
flank pain and hematuria are most common symptoms
what is the imaging of choice for nephrolithiasis?
non-contrast low radiation CT
what are the signs associated with renal tumors?
hematuria, flank pain, non-specific Sx (fever, weight loss, loss of appetite)
what imaging should you use for renal tumors?
renal US for primary evaluation
renal CT for detection of masses.
“KUB” X-ray
abdominal x-ray used for kidneys, ureters, and bladder
not commonly performed in patients with suspected renal disease
can be used for nephrolithiasis but low-dose CT is modality of choice
what are the cons of KUB x-ray?
cannot visualize radiolucent uric acid stones, small radiopaque stones, stones overlying bony structures
define diaphoretic
inducing perspiration
