ultrasound
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Hepatobiliary UltrasoundHepatobiliary Ultrasound
Introduction to Emergency Ultrasound
GoalsGoals
Why ultrasound?Why ultrasound? AnatomyAnatomy TechniqueTechnique CholelithiasisCholelithiasis CholecysitisCholecysitis Pearls and PitfallsPearls and Pitfalls
Why ultrasound?Why ultrasound?
Hepatobiliary imaging modalities:Hepatobiliary imaging modalities:– UltrasoundUltrasound– CTCT– HIDAHIDA– MRIMRI– ERCPERCP
Benefits of UltrasoundBenefits of Ultrasound– Performed at bedsidePerformed at bedside– Fast information within 5-10 minutesFast information within 5-10 minutes– No radiation, No contrast, Low costNo radiation, No contrast, Low cost– Sensitivity 94% with specificity 78%Sensitivity 94% with specificity 78%
-Shea Arch Int Med 1994-Shea Arch Int Med 1994
Why ultrasound?Why ultrasound?
Evaluation for:Evaluation for:– CholelithiasisCholelithiasis– CholecystitisCholecystitis– CholedocholithiasisCholedocholithiasis– JaundiceJaundice
1242 patients over 3 years receiving RUQ 1242 patients over 3 years receiving RUQ USUS– 753 from EPs753 from EPs– 489 from radiology489 from radiology
Average decrease in LOS 22 minutes if Average decrease in LOS 22 minutes if received EP USreceived EP US
After hours LOS decreased by 1:13 in EP US After hours LOS decreased by 1:13 in EP US groupgroup
Academic Emergency Medicine 1999
RUQ AnatomyRUQ Anatomy
Gallbladder:Gallbladder:
Posterior to LiverPosterior to Liver
(acoustic (acoustic window)window)
Right of the Portal VeinRight of the Portal Vein
Anterior to DuodenumAnterior to Duodenum(Beware of Fake-(Beware of Fake-
outs)outs)
GB Variable LocationGB Variable Location
Scan entire RUQScan entire RUQ– Midline to Mid-Midline to Mid-
axillary lineaxillary line
Always Right of Always Right of Falciform Falciform LigamentLigament
Usually Right of Usually Right of Portal VeinPortal Vein
GB US AnatomyGB US Anatomy GallbladderGallbladder
– 7-8 cm long7-8 cm long– 2-3 cm diameter2-3 cm diameter
Max normal <4 cmMax normal <4 cm
GB wallGB wall– <2mm (97% cases)<2mm (97% cases)– Three layersThree layers
Outer – reflectiveOuter – reflective Muscular – anechoicMuscular – anechoic Inner – reflectiveInner – reflective
– Measure -transverse viewMeasure -transverse view
GB US anatomy - vascularGB US anatomy - vascular
Distinguishing Hepatic Veins from Portal Distinguishing Hepatic Veins from Portal VeinsVeins•Hepatic VeinsHepatic Veins
-Thin Walled-Thin Walled-Converge into IVC-Converge into IVC
•Portal VeinsPortal Veins -Echogenic Walls-Echogenic Walls -Branch from Portal Vein-Branch from Portal Vein
TechniqueTechnique
Liver is sonographic Liver is sonographic windowwindow
NPO (yeah, right)NPO (yeah, right) Probe - curvilinear 2-5 MHzProbe - curvilinear 2-5 MHz Patient positioningPatient positioning
– SupineSupine SubcostalSubcostal Deep inspiration and holdDeep inspiration and hold
– Diaphragm pushes liver and Diaphragm pushes liver and gallbladder down gallbladder down
– Left lateral decubitusLeft lateral decubitus Allows GB drop downAllows GB drop down
– Intercostal obliqueIntercostal oblique Liver window thru ribsLiver window thru ribs
TechniqueTechnique
ScanScan– Orientation marker toward head in Orientation marker toward head in
midlinemidline– Scan laterally under R costal marginScan laterally under R costal margin– Expect to see gallbladder around Expect to see gallbladder around
midclavicular linemidclavicular line– Rotate probe to transform image of GB Rotate probe to transform image of GB
into long axis viewinto long axis view– Confirm that it is GB by it's "pointing" to R Confirm that it is GB by it's "pointing" to R
portal vein along main lobar fissureportal vein along main lobar fissure
TechniqueTechnique
Main Lobar Fissure between gallbladder and right portal vein
TechniqueTechnique
Two perpendicular Two perpendicular views, fanning views, fanning through gallbladderthrough gallbladder– LongitudinalLongitudinal– TransverseTransverse
9090oo counterclock to counterclock to
longitudinal, fundus longitudinal, fundus to neckto neck
Real time scanningReal time scanning– Through the entire Through the entire
organorgan
TechniqueTechnique
MeasurementsMeasurements– GB wall thicknessGB wall thickness
anteriorlyanteriorly
– GB diameterGB diameter– Common bile ductCommon bile duct 4
Anatomy ConsiderationAnatomy Consideration Note gallbladder’s proximity to duodenumNote gallbladder’s proximity to duodenum
– Frequent error of noviceFrequent error of novice
Anatomy ConsiderationAnatomy Consideration Normal FoldsNormal Folds
– Crisp folds are Crisp folds are normalnormal
– Hartman's pouchHartman's pouch folded neck folded neck
– Apical fold 3%Apical fold 3% ““Phrygian cap”Phrygian cap”
– Septations in neckSeptations in neck ““valves of Heister”valves of Heister”
GB – Imaging PitfallsGB – Imaging Pitfalls
Misidentifying duodenum for GBMisidentifying duodenum for GB Unusual anatomic locationUnusual anatomic location Contracted after eatingContracted after eating
– Smaller thereby harder to findSmaller thereby harder to find– Contracted GB has thicker wallsContracted GB has thicker walls
Walls still <4mmWalls still <4mm
Missing the gallbladder neckMissing the gallbladder neck Bowel gas interfering with imagingBowel gas interfering with imaging
Porta HepatisPorta Hepatis
Portal TriadPortal Triad
Hepatic ArteryHepatic Artery
Common Bile Common Bile DuctDuct
Portal VeinPortal Vein
CBD US AnatomyCBD US Anatomy
<4mm (98% <4mm (98% cases)cases)– Inner wall to inner Inner wall to inner
wallwall– Bachar JUM 2005Bachar JUM 2005
Can increase by Can increase by 1mm/10 yrs age.1mm/10 yrs age.
>10 mm = >10 mm = – Likely obstructionLikely obstruction
Landmark methods for Landmark methods for finding CBDfinding CBD
Portal Vein - Portal Vein - ExtrahepaticExtrahepatic– Runs longitudinallyRuns longitudinally– Towards pt’s right Towards pt’s right
shoulder shoulder – 11 O’clock11 O’clock– Rotate to 8 O’clockRotate to 8 O’clock
Porta HepatisPorta Hepatis
Mickey Mouse SignMickey Mouse SignRight Ear – Common Bile Duct
Left Ear – Hepatic ArteryFace – Portal Vein
Landmark methods for Landmark methods for finding CBDfinding CBD Find “Confluence”Find “Confluence”
– Splenic vein joins the SMV to become Portal VeinSplenic vein joins the SMV to become Portal Vein– Probe located in Epigastric - TRVProbe located in Epigastric - TRV
Porta Hepatis - PitfallsPorta Hepatis - Pitfalls
Misidentification of right portal Misidentification of right portal vein as the Common Portal Veinvein as the Common Portal Vein
Porta Hepatis off axisPorta Hepatis off axis Inability to use liver windowInability to use liver window
Left lateral decubitusLeft lateral decubitus Have patient take deep breath and holdHave patient take deep breath and hold
– Brings down liver to use as windowBrings down liver to use as window Intercostal viewIntercostal view
– Intercostal views take practice and patienceIntercostal views take practice and patience
CholelithiasisCholelithiasis
U/S Gallstone FindingsU/S Gallstone Findings Strongly EchogenicStrongly Echogenic Posterior Acoustic Posterior Acoustic
ShadowingShadowing– ““Clean” shadowingClean” shadowing
MobileMobile– MoveMove with with change change
in patient positionin patient position
Convenience sample of 109 ED patients Convenience sample of 109 ED patients undergoing RUQ ultrasound by radiology undergoing RUQ ultrasound by radiology had EP RUQ US performedhad EP RUQ US performed
49/51 patients had their gallstones 49/51 patients had their gallstones detected on EP RUQ US (96% [87-99])detected on EP RUQ US (96% [87-99])
51/58 pts without gallstones correctly 51/58 pts without gallstones correctly identified by EP RUQ US (88% [77-95])identified by EP RUQ US (88% [77-95])
Journal of Emergency Medicine 2001
CholelithiasisCholelithiasis
CholelithiasisCholelithiasis
CholelithiasisCholelithiasis
CholelithiasisCholelithiasis
CholelithiasisCholelithiasis
Cholelithiasis - WES signCholelithiasis - WES sign
SludgeSludge Sludge is precursor of stonesSludge is precursor of stones
– significance depends clinicallysignificance depends clinically– including other US findingsincluding other US findings
– Ohara 1990, Lee 1988Ohara 1990, Lee 1988 Bizarre echogenic “lava-lamp” Bizarre echogenic “lava-lamp”
shapesshapes– Change with movement => Change with movement =>
flows flows Can resemble tumorCan resemble tumor ““pseudosludge” artifactpseudosludge” artifact
– beam width /side lobe beam width /side lobe artifacts artifacts
do not layer out with gravitydo not layer out with gravity extend beyond walls of GBextend beyond walls of GB inconsistent between viewsinconsistent between views
Various Stages of SludgeVarious Stages of Sludge
Normal layering Clumpped
29559978 RUQ sludge filled GB29559978_2.2.2005.18.37.5_5.avi
Sludge versus StonesSludge versus Stones
SludgeSludge ContinuumContinuum Crystallized Bile SaltsCrystallized Bile Salts Allow passage of ultrasound Allow passage of ultrasound
waveswaves No shadowing seenNo shadowing seen
StonesStones End of the continuumEnd of the continuum Density prevents passage of Density prevents passage of
ultrasoundultrasound ““Clean” shadowingClean” shadowing
CholecystitisCholecystitis
CholecystitisCholecystitis
Signs and symptomsSigns and symptoms– RUQ abdominal painRUQ abdominal pain– Murphy’s signMurphy’s sign– Fever/ ChillsFever/ Chills– LeukocytosisLeukocytosis– Jaundice (choledocolithiasis)Jaundice (choledocolithiasis)
Later findingLater finding
PathophysiologyPathophysiology ObstructionObstruction
Aseptic Aseptic InflammationInflammation
Wall EdemaWall Edema
InfectionInfection
Cholecystitis: US FindingsCholecystitis: US Findings GallstonesGallstones Sonographic Sonographic
Murphy’sMurphy’s GB wall edemaGB wall edema
– Especially FocalEspecially Focal GB wall thickeningGB wall thickening Increased Increased
TransverseTransverseGB diameterGB diameter
Pericholecystic fluidPericholecystic fluid
Sonographic Murphy’s signSonographic Murphy’s sign Find gallbladder Find gallbladder
and press on it.and press on it.
Sensitivity 60 – 95%Sensitivity 60 – 95% Specificity 90 – 95%.Specificity 90 – 95%.
– Ralls 1985, Ralls 1982, Simeone 1988Ralls 1985, Ralls 1982, Simeone 1988
92% PPV 92% PPV SonoMurphy+stonesSonoMurphy+stones
Morphine does not Morphine does not interfere with examinterfere with exam
-Nelson JEM v28, 2005-Nelson JEM v28, 2005
Sonographic Murphy's by EPSonographic Murphy's by EP– Sensitivity = 75%Sensitivity = 75%– Specificity = 55%Specificity = 55%– Positive predictive value = 17%Positive predictive value = 17%– Negative predictive value = 95%Negative predictive value = 95%
Journal of Emergency Medicine 2001
Wall ThicknessWall Thickness
NormalNormal AbnormalAbnormal
Usual thickness – 2mm (4mm upper limit normal)Usual thickness – 2mm (4mm upper limit normal) In the clinical setting of acute cholecystitis about 90 - In the clinical setting of acute cholecystitis about 90 -
100% specific, 50 - 70% sensitive100% specific, 50 - 70% sensitive Finberg 1979, Birnholz 1981Finberg 1979, Birnholz 1981
Thickened walls can be due to medical disease ie anasarcaThickened walls can be due to medical disease ie anasarca
Wall thicknessWall thickness
Note the edema separating the wallsNote the edema separating the walls
Other causes of thickened Other causes of thickened wallswalls
55 consecutive patients w/ thick walls55 consecutive patients w/ thick walls– one third due to biliary diseaseone third due to biliary disease– out of 28 with medical etiologies:out of 28 with medical etiologies:
19 due to hypoproteinemic states19 due to hypoproteinemic states 9 due to CHF, 6 due to liver disease, 4 due to 9 due to CHF, 6 due to liver disease, 4 due to
CRFCRF 3 due to pancreatitis3 due to pancreatitis
– CohCohan 1987an 1987
Also associated w/ AIDS and ascitesAlso associated w/ AIDS and ascites
Increased Transverse Increased Transverse DiameterDiameter
> 4-5 cm > 4-5 cm diameterdiameter– Sens 84.4%Sens 84.4%
– Weedle 1986Weedle 1986
Dependent on Dependent on degree of degree of inflammatory inflammatory processprocess
Pericholecystic FluidPericholecystic Fluid Seeping Seeping
inflammatory fluidinflammatory fluid– GallbladderGallbladder– LiverLiver
Consider Consider PerforationPerforation
CholedocolithiasisCholedocolithiasis
View Portal TriadView Portal Triad– Common bile ductCommon bile duct
Avg size 4 mmAvg size 4 mm Incr 1mm/ 10 yrsIncr 1mm/ 10 yrs Up to 10 mm post Up to 10 mm post
cholecystectomycholecystectomy >10 mm >10 mm → →
ObstructionObstruction
CholedocolithiasisCholedocolithiasis
Allow 1 mm for each decade to max Allow 1 mm for each decade to max 8.5mm8.5mm
-Bachar JUM 22, 2003 -Bachar JUM 22, 2003
CBD increased after cholecystectomy, CBD increased after cholecystectomy, with age and weightwith age and weight
Wu 1984Wu 1984
In acute obstructionIn acute obstruction– extrahepatic ducts dilate in > 24 hoursextrahepatic ducts dilate in > 24 hours– intrahepatic ducts 1 to 2 days laterintrahepatic ducts 1 to 2 days later
Intrahepatic CholestasisIntrahepatic Cholestasis
-Too manytubes
-best seen in transverse L liver
Liver MassesLiver Masses Check echodensity for homogeneityCheck echodensity for homogeneity– Heterogeneous - consider masses vs edemaHeterogeneous - consider masses vs edema
Liver MassesLiver Masses
Pitfalls – Bowel GasPitfalls – Bowel Gas
Proximity to Proximity to colon colon – Hepatic Hepatic
flexureflexure– Gas artifactGas artifact
Impossible to Impossible to state stones.state stones.
And so rememberAnd so remember
Real time dynamic scanning Real time dynamic scanning GallbladderGallbladder
– 4mm (GB wall)4mm (GB wall)– 4cm (GB diameter)4cm (GB diameter)
CBDCBD– Usually <4mmUsually <4mm– <10 mm max in elderly patient<10 mm max in elderly patient
Gallstones always make clean shadowsGallstones always make clean shadows Sludge resembles “lava lamp” layeringSludge resembles “lava lamp” layering Check the neck for hidden stonesCheck the neck for hidden stones
Tips for improving viewTips for improving view
Supine view with patient holding Supine view with patient holding deep breath to move liver downdeep breath to move liver down
Intercostal oblique at anterior Intercostal oblique at anterior axillary lineaxillary line
Still can't find the gallbladder?Still can't find the gallbladder? Transverse view of upper pole R kidney, Transverse view of upper pole R kidney,
then look medial for GBthen look medial for GB Coronal view of Morison's pouch, then fan Coronal view of Morison's pouch, then fan
20 degrees anteriorly for GB20 degrees anteriorly for GB
PitfallsPitfalls
Bowel gas obscuring the Bowel gas obscuring the gallbladdergallbladder
Failure to thoroughly scan the neck Failure to thoroughly scan the neck of the gallbladderof the gallbladder
Mistaking the duodenum for the Mistaking the duodenum for the GBGB
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