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