ULS Flashcards
ocular ddx
retinal detachment
floating membrane
cobble stoning is seen with cellulitis of abscess
cellulitis
how can ULS help with pain mngmt
nerve block
helps to isolate nerve plexus under fascia layer
takes away all the pain for a femur fracture
ACUTE DYSPNEIC PATIENT ddx
MI PE COPD asthma CHF
A lines
seen in a normal aerated lung
vertical b line artifacts
interstitial edema
air water are creating vertical artifact
B lines with fat IVC and dyspnea
decompensating heart failure
hip arthrocentesis
helps visual landmarks in bigger pts
the more tissue you have to get through the harder it is to see below it
when injecting local anesthetic and steroids
goes deep
seen as kind of grainy
good for seeing the aorta
low frequency probe
allows for the visualization of superficial structures that are tender
high frequency probe
bright or white described as
hyperechoic
things which are fluid are seen as
dark or anachoic
most solid organs
appear more grey
few or no echoes (appears black)
Anechoic (echolucent)
Reflects many echoes (appears bright or white)
Hyperechoic (echogenic
Poor Propagation
Air
Very Echogenic (Very Bright)
■ Bone
Echogenic (bright)
Muscle
Echogenic (less bright)
Liver/Kidney
Hypoechoic (Dark) usually indicative of
Blood/Fluid
the dot of the probe marker
usually facing pts head or right
structures on the right side of the screen correlate to the right side of the body if the probe marker is on the right
Define how ultrasound images are created.
Ultrasonic waves are emitted by the probe (aka “transducer”) and are either transmitted through OR bounce back from the objects they touch
increasing the gain on the US
will make it go from dark to really bright
How much sound is transmitted vs reflected is called
acoustical impedance
As the density of the object increases, impedance will
also increase
From greatest to least acoustic impedance:
fluid
gas
bone
bone > gas > fluid
fluid mainly transmits the sound waves and does not reflect
Gas, bone, & stones will
Gas, bone, & stones reflect sound waves so well that they cast a shadow (which is why it’s hard to see
stuff deep to a bone or deep to bowel gas)
5 adv of ULS
No ionizing radiation
- No known side effects
- “real-time” images
- Produces little or no pt discomfort
- Small, portable, inexpensive, ubiquitous
disadv of ULS
Difficulty penetrating through bone Can’t do the head! (except eyeballs)
- Gas-filled structures reduce its utility
- Difficulty penetrating through fat tissue - Depends heavily on operator skill
what are the clinical indications of ULS the biliary tract
Cholelithiasis Cholecystitis
M mode
stands for motion
allows you to see the movement of what’s going through this line
waves on the beach
RUQ pain would use ULS for what structure
biliary tract
Cholelithiasis Cholecystitis
- First-choice study for RUQ pain or suspected problems of biliary system; Better than CT!
mitral stenosis and M mode
loose “kick”
get flat E and A wave
indication for cardiac ULS
Pneumothorax
Pleural effusion
Pulmonary edema
Heart – valves (sorta), contractility, size, effusion
- Study of choice in ED for acute dyspnea is known as
what can it help with
- Study of choice in ED for acute dyspnea (i.e. the “Triple Scan”)
● Great for determining hypo- vs hyper-volemia
● Can also suggest causes of dyspnea (cardiac? Lung?
lets you see colors of moving fluid
Power Doppler
torsion
non traumatic pain and swelling
low flow state in testicals difficult to pick up on ULS
spectral dopplar
allows you to differentiate between arteries and veins
shadows
can help you differentiate artifacts that are thick and hard
like gallstones from sludge
WES
wall echo shadow sign from a ton of stoned
GOAL of fast exam
detect those pts that need an urgent laparotomy
identify shock in the early phases in order to increase perfusion.
Unstable + positive FAST
go to
OR
Stable + positive FAST
CT
Stable + negative FAST
Stable + negative FAST → CT vs. re-examine
Indications for FAST
■ Blunt Abdominal Trauma
■ Penetrating Abdominal Trauma
■ Unexplained Hypotension after Trauma
■ Evaluation of Pregnant Patient after Trauma
○ FAST Exam – 4 views
4 views of a FAST exam
what are we looking for in a FAST exam
FAST exam looks for abdominal fluid collection, as well as pericardial effusion
what did we do before the FAST exam
diagnostic peritoneal lavage
DPL
FAST stands for
Focused Assessment with Sonography in Trauma
how much fluid must be around to be detected in ULS
■ How much fluid for a positive FAST? → 350 cc
FAST sensitivity for bleeds
87%
neg ULS and CT
can still have issues
could need observation for 24 if they are still tender or can’t eat without vomiting
RUQ FAST what’s it called
what plane
probe in what orientation
Hepatorenal – Mid axillary line or slightly posterior; 11th ICS, at level w/ lower sternum to start.
Probe in cranial-caudal orientation
Coronal plane.
Morrison’s pouch
what is it and what are we worried about
between liver & R kidney (liver
normally abuts kidney)
looking for dark stripe of fluid worried about blood in this area
what should we be checking for in a RUQ ULS
Check the pleural space ( shouldn’t be able to see detail
in the lung! If yes → fluid!)
● Check Subphrenic space (pleura is white curved line
that normally abuts liver)
● Check Morrison’s pouch between liver & R kidney (liver
normally abuts kidney)
● Check inferior pole of R kidney
what can give us a false positive Morisson’s pouch
perinephric fat pad
what will a hem -thorax look like on a FAST exam
can see in RUQ as black above the liver
Mid-epigastrium, with probe dot toward 9 o’clock, imaging through to heart.
Subxiphoid
doesn’t work great is pregnant or heavy pain
can do substernal
LUQ what is it called and what is the placement
Splenorenal –
Like RUQ but a bit more inferior and posterior (brace hand on the bed). Post axillary line, 10th ICS, coronal plane.
what are we looking for in the LUQ
Check subphrenic space & pleural space (OFTEN fluid is
here 1st between dome of spleen and diaphragm!)
● Check spleen
● Check interface between L kidney and spleen
● Check inferior pole of kidney
where do we usually see bleeding first in the LUQ
usually between spleen and diaphragm before
diaphragm and kidney
dark circular fluid near the spleen
gastric fluid sign
two views used to look at the pelvis
transverse and sagittal
how do you know if the probe is angles correctly in pelvic exam
Angle probe down into pelvis until you see base of
bladder w/ vaginal stripe (or prostate).
sharp angles in a pelvic exam
are indicative of abnormal fluid collection
usually where to we start with a focus echo
start out adjacent to the sternum and point to the pts right shoulder
apical 4
down at the apex shooting up with the probe marker towards right leg
good for assessing chamber size
helps if you roll the pat on their left
breath out and hold
aim upwards toward right shoulder
sub-xiphoid probe marker should be pointed
just below the right nipple
best view for pts with COPD
subxiphoid
usually displaced inferiorly
if there is a pericardial effusion what are we worries about
tamponade with quick accumulation of fluid
beck’s triad
for tamponad
JVD
hypotension
muffled heart tones
pulses paradoxes
seen with tamponade and creating negative pressure
tight space leads to r ventricular diastolic collapse
bp goes down
what will tell us if we have tamponade in ULS
right ventricle collapse with effusion
will look like the wave
comet tail artifacts
are normal in ULS of lunges
With regards to the aorta when would you get an ULS and what would you be looking for?
First-choice study for asymptomatic pulsatile abdominal mass
CT + contrast is the gold std for characterizing the aneurysm
Abdominal Aortic Aneurysm
Aortic dissection
with regard to the kidneys why would you get a ULS
- First-choice study for renal colic
- Primarily looks for hydronephrosis
- Cannot visualize ureters or stones.
with regards to the female reproductive system why would you get a ULS
- First-choice study for pelvic mass or pelvic pain in female
- First-choice study for evaluating ovaries
Leiomyomas (MC uterine tumor)
Ovarian cysts
PID
Intrauterine pregnancy (vs. ectopic) trans-vaginal US best
when would you use a cT in the pelvic area for a woman
CT used for staging/evaluating masses found on ULS
why would us use ULS for the male reproductive system
Testicular or scrotal mass
Testicular torsion
*First-choice study for acute scrotal pain
why would you use ULS for SST
First-choice for quick distinction between abscess vs. joint-capsule effusion
*First choice for joint dislocations
Abscess
Joint capsule effusion
Subluxation/Dislocation
why would you get a ULS of the venous/arterial system
- Useful pre- and post-op screening for
vascular procedures
*Study of choice for DVT (especially sensitive in a symptomatic pt with DVT above the knee) - Refer for more thorough US exam if neg.
Carotid artery stenosis
DVT
why would you get a ULS of the cardiac/lung region
Study of choice in ED for acute dyspnea (i.e. the “Triple Scan”)
- As above, refer for more thorough exam (CT, echocardiogram) if questionable data
Pneumothorax
Pleural effusion
Pulmonary edema
Heart - valves (sorta), contractility, size, effusion
what are we looking for with a FAST other than abd fluid
Pleural effusion
Certain cardiac abnormalities (tamponade
what types of procedural guidance would ULS be useful for
Tapping joint capsules for fluid
US-guided venous catheter
US-guided nerve block
- Much better than “landmark” method for tapping joints
- Much better than “putting a central line in everyone we can’t get an IV into”
- Great for pain relief
what can cast an acoustic shadow
Bone, metal, glass, stones cast an acoustic shadow
E.g. ribs cast a shadow over all structures visualized through the ribcage
Edge artifact
can also cast a shadow (occurs at edge of hollow organ like gallbladder)
what is on the ddx for a triple scan
CHF COPD Asthma PNA PE Effusion ARDS Metabolic pneumothorax
what are the three views we are looking at in a triple scan
lung
echo
IVC
Questions we want to answer when utilizing echocardipgraphy in a triple scan
LV function normal poor or hyper-dynamic? (look at EF)
(visual)
pericardial effusion? tamponade?
signs of heart strain?
what will an IVC look like in an echo that will clue you to the dx
▪ IVC that expands/contracts normally during respiration = euvolemia
▪IVC that remains expanded and full = hypervolemia, PE, tamponade, tricuspid-reg, CHF
what are you looking for in a lung with the triple scan
A-lines: look like horizontal lines parallel to the pleura, surrounded by a “cloud” of artifact
B line: interstitial edema
liquid or air is creating an artifact
(non-cardiogenic pulm edema)
. Parasternal long axis in a triple scan helps visualize
Look at mitral valve, LV, aortic outflow, RV
Examine for pericardial effusion &/or tamponade physiology (i.e. RV collapse)
how do you hold the Parasternal long axis in a triple scan helps visualize
- probe over 2nd - 4th IC space, dot toward 9:00
how do you hold the probe for IVC view (sub-xyphoid
- probe dot cranial, probe facing midline but slightly toward R shoulder
. Parasternal short axis
probe probe over 2nd - 4th IC space, just turn so dot faces pts R hip
indications for ocular ULS
retinal detachment vitreous hemorrhage vitreous detachment foreign body lens dislocation retrobulbar hematoma pupillary light reflex optic nerve sheath diameter
virtuous hemorrhage will appear as
echogenic / hyperechoic
new hemorrhage : small dots or lines
viterous attachment
thick hyper-echoic linear density
usually thinner and smoother than retinal detachment and will not be anchored
will occur in front of the optic nerve
retrobulbar hematoma is seen as what on ULS
displaced optic nerve
which side to gallstones typically fall to?
- Fall to the dependent side
describe the appearance of gallbladder sludge on ULS
Sludge looks gravel-y but does NOT cast a shadow
what is the usual measurement of the aorta
Aorta normally measures <3cm across
describe the appearance of hydropnephrosis on ULS
- Normal kidney is 9-12cm x 4-5cm x 3-4cm (bar of soap)
- Normal renal sinus is echogenic; surrounding pyramids & cortex are hypoechoic.
- Hydronephrosis:
- Dilated and fluid-filled (hypoechoic) renal pelvis
- Severe hydronephrosis may distort the dimentions of the kidney, too
LV contractility variable, RV dilation variable, A-lines, IVC variable (often collapsing)
Not ADHF
Asthma/COPD, Acidosis, Small PE
LV contractility normal, focal B-lines/consolidation, IVC non-plethoric (flat)
non-plethoric (flat)
Pneumonia
LV contractility good, diffuse B-lines, IVC collapsing
Non-Cardiogenic Pulmonary Edema (ARDS)
LV contractility good, diffuse B-lines, IVC plethoric/variable, BP high
Diastolic Failure, Flash Pulmonary Edema
Elbowing mitral valve and LA enlargement, diffuse B-lines, IVC plethoric
Critical Mitral Stenosis Pulmonary Edema
Cholecystitis dx on ULS
Thickening of gallbladder wall (>3mm)
- Pericholecystic fluid (fluid just outside gallbladder)
- Positive “Sonographic Murphy’s sign” (NOTE: only + if the
common site for AAA
Commonly occur distal to the renal arteries, often near the bifurcation
