Ultrasound Clinics Pediatric Ultrasound Intraoperative Ultrasound, An Issue of Ultrasound Clinics

122 Pages·2006·12.41 MB·English

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U LT R A S O U N D
C L I N I C S
UltrasoundClin1(2006)xi
Preface
BrianD. Coley,MD
Department of Radiology
ColumbusChildren’sHospital
700Children’sDrive
Columbus,OH 43205,USA
E-mailaddress:
[email protected]
BrianD.Coley,MD
GuestEditor
ThisissueoftheUltrasoundClinicsreviewssomeof you only recognize the conditions that you know.
the uses of ultrasound in the pediatric patient. Ultrasound, unfortunately, is often given little
Giventheirgenerallysmallersize,childrenareideal weightincurrentradiologytraining,isoftenpoorly
candidatesforultrasoundevaluation.Inthecurrent understood by practicing radiologists, and often
imagingenvironment,MRimagingandCTreceive relegatedtoascreeningroleuntilthepatientcanbe
themostinterestofallofthemodalities,andthey scheduledforCTorMRI.Thisisunfortunate.Itonly
are powerful indeed. However, radiologists in takesalittlebitofefforttounderstandultrasound
North America are finally gaining the awareness (even scanning a patient yourself on occasion) to
of our European colleagues about the potential appreciate what real-time gray-scale and Doppler
detrimental effects of diagnostic radiation in the evaluationcanshow.
very young, and MR imaging often requires The contributing authors bring a wealth of
sedation and is not always expediently available. internationalexperienceandperspectivetopediat-
Ultrasoundisoftenunderappreciatedinthefaceof ric ultrasound. I am grateful to them for their
these other modalities. Pediatric ultrasound pro- efforts.ThanksarealsoduetoBartonDudlickand
vides detailed anatomic information and is the the staff of Elsevier for their expertise and care in
originalmultiplanarmodality.Dopplerstudiescan production.Ihopethatthearticlespresentedhere
add important functional and physiological in- interest you, helpyouto care for the children you
formation.Anyimagingmodalitycanonlyprovide encounter, and encourage you to explore and
theinformationthatyouknowhowtolookfor,and expandtheuseofultrasoundinyourpractice.
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U LT R A S O U N D
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UltrasoundClin1(2006)431–441
Jaundice in Infants and Children
Marilyn J. Siegel, MD
- Sonographicexamination Spontaneousperforationofthe
- Overviewofcholestaticdiseases extrahepaticbileducts
- Neonataljaundice Inspissatedbilesyndrome
Biliaryatresia - Jaundiceinolderinfantsandchildren
Neonatalhepatitissyndrome Carolidisease
Additionalimagingstudiesto Bylerdisease
differentiateatresiaandhepatitis Hepatocellulardiseases
Alagillesyndrome Inflammatorydiseasesofthebiliaryducts
Choledochalcyst Biliarytractobstruction
- References
Real-time sonography remains the screening echogenicityofthenormalliverislowtomedium
study of choice for the evaluation of jaundice in and homogeneous, and the central portal venous
infantsandchildrenanditisanimportanttoolin vasculature is easily seen (Fig. 1). In the neonate
differentiating between obstructive and nonob- andyounginfant,thehepaticparenchymaandre-
structive causes of jaundice [1,2]. The causes of nal cortex are equally echogenic. In individuals 6
cholestasisaremultiple,butthethreemajorcauses monthsof age and older,the liver usuallyis more
are hepatitis, biliary atresia, and choledochal cyst. echogenic than the kidney. The patency and flow
Othercausesincludeneoplasticprocesses,cirrhosis, direction of the hepatic vessels should be do-
andstrictures. cumentedwithpulsedandcolorDopplerinterroga-
Thisarticlereviewsthecommoncongenitaland tion. The liver and adjacent area should also be
acquiredcausesofjaundiceinthepediatricpatient evaluatedforevidenceofend-stageliverdisease,in-
and describes the sonographic findings associated cluding collateral channels (varices), hepatofugal
withtheseconditions.Theroleofcorrelativeimag- flow,andascites.
ingstudiesisalsoreviewed. The diameter of the common duct should be
measuredonthesagittal scanto confirmthepres-
ence or absence of ductal dilatation. The upper
Sonographic examination
limits of the common duct should not exceed 1
The sonographic examination of infants and chil- mm in neonates, 2 mm in infants up to 1 year of
drenwhohavejaundiceincludesadetailedexami- age, 4 mm in children 1 to 10 years of age, and 6
nation of the liver, bile ducts, gallbladder, and mminadolescentsandyoungadults[3].Thedistal
pancreas. Hepatic size and echotexture should be portionofthecommonductistypicallylargerthan
thoroughlyassessed.Therighthepaticlobeshould the proximal portion. Ductal size may increase by
extend to or just below the right costal margin 1 mm or more during deep inspiration and the
in a patient without hyperinflated lungs. The Valsalva maneuver [4]. The cystic duct in children
Radiology and Pediatrics, Mallinckrodt Institute of Radiology, Washington University School of Medicine,
510SouthKingshighwayBoulevard,St.Louis,MO,63110,USA
E-mailaddress:[email protected]
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ultrasound.theclinics.com
432 Siegel
(1)neonataland(2)olderchildandadolescent.In
the neonate, biliary atresia, the neonatal hepatitis
syndrome,andcholedochalcystarethemostcom-
moncausesofjaundice[7–9].Othercausesinclude
syndromicandnonsyndromicbileductpaucity,in-
spissatedbilesyndrome,andspontaneousperfora-
tionoftheextrahepaticbileduct.Inolderchildren,
jaundiceismostoftencausedbyhepatocellulardis-
ease,includinghepatitisandcirrhosis.Biliarytract
obstruction is a less common cause of childhood
jaundice. The possible causes of obstructive jaun-
diceincludecholedochalcyst,cholangitis,stricture,
stones,andneoplasms.
The results of various laboratory tests of liver
function,inconjunctionwiththepertinenthistori-
calandphysicalfindings,generallysufficetodiffer-
Fig. 1. Normal liver. Transverse sonogram shows ho-
entiate between obstructive and nonobstructive
mogeneoushepaticparenchyma.Theechogenicpor-
tal venous vasculature (arrows) is easily seen. The causesofjaundice.Imagingexaminationsareused
gallbladder (GB) is distended and the wall is thin to confirm the clinical impression. In patients
andhyperechoic.PV,portalvein. who have obstructive jaundice, these studies may
alsooftenshowthelevelandcauseofobstruction.
Sonography is the preliminary imaging proce-
is not routinely seen unless it is dilated, and then
dure. If the extrahepatic ducts are well visualized
usuallyonlythedistalpartoftheductnearitsinser-
bysonographyandarenormalincaliberandthere
tionintothecommonbileductisseen.
isnoevidenceofintraductaldilatation,furtherra-
Gallbladder size usually can be assessed subjec-
diologic evaluation is rarely needed. Sonography
tively,butmeasurementsmaybehelpfulinequivo-
issupplementedbyradionuclidestudiesusinghep-
cal cases. The normal gallbladder length is 1.5 to
atobiliary agents (99mTc-IDA analogs) when func-
3.0cminneonatesandyounginfants(youngerthan
tional information is needed. Hepatobiliary
1yearold)andthewidthisapproximately1cm.In
scintigraphycurrentlyisusedprimarilytoconfirm
olderchildrenandadolescents,gallbladderlengthis
suspected diagnoses of choledochal cysts, biliary
3to8cmandwidthislessthan3.5cm.Thewallof
atresia, and neonatal hepatitis. CTor MR imaging
the gallbladder should be thin, hyperechoic, and
arereservedforcasesinwhichmore anatomicde-
well defined. The upper limits of wall thickness in
tail is needed for surgical planning or the level
thefastingstateare3mm[5].
or cause of obstruction cannot be determined by
Feedingofafattymealmaybehelpfulinpatients
sonography[10–15].
whohaveenlargedgallbladderstoassesscysticduct
patency. In healthy individuals, maximum empty-
Neonatal jaundice
ing of the gallbladder occurs between 45 and 60
minutesafterthefattymeal,andthemeanvolume Biliary atresia
decreases approximately 60%. Contraction of the
Biliaryatresiaisararediseasewithanincidenceof1
gallbladderafterafattymealsupportsthediagnosis
in8,000to10,000livebirths.Itis,however,thesin-
ofapatentcysticduct.
glemostcommoncauseofneonatalcholestasis,ac-
Pancreaticsize,echotexture,andductalsizeshould
countingfornearly90%ofthesurgicalcausesand
beevaluated.Pancreaticsizeincreaseswithincreas-
for approximately 40% of all causes of cholestasis
ingageofthechild[6].Themeancross-sectionaldi-
[16]. The cause is unclear, but it is believed to be
ameterofthepancreaticheadrangesbetween1and
causedbyinuteroinflammationthatresultsinfail-
2cm,thebodybetween0.6and1.1cm,andthetail
ureoftheremodelingprocessatthehepatichilum
between 1 and 2 cm. The normal pancreas is iso-
[7].Histologically,itischaracterizedbyabsenceof
echoic or minimally hyperechoic compared with
the extrahepatic bile ducts, proliferation of the
theliver.Thecross-sectionaldiameterofthepancre-
small intrahepatic bile ducts, periportal fibrosis,
aticductshouldnotexceed1to2mm.
and occasionally multinucleated giant cells. There
isaspectrumofchanges,dependingontheextent
oftheobliterativeprocess.Completeatresiaispres-
Overview of cholestatic diseases
entin75%to85%ofcases.Intheremainingcases,
Causesofcholestasisvarywithpatientage.Forthis theremaybepatencyofthegallbladderandcystic
review,diseasesareclassifiedintotwomainclasses: ductorpatencyofonlythegallbladder.Associated
JaundiceinInfants&Children 433
anomalies are common (10%–20% of patients)
andincludecholedochalcyst,polysplenia,pre-duo-
denalportalvein,azygouscontinuationoftheinfe-
riorvenacava,diaphragmatichernia,situsinversus,
andhydronephrosis[16–18].
Patients who have biliary atresia and neonatal
hepatitis usually present at 1 to 4 weeks of age
with jaundice. Distinguishing between neonatal
hepatitis and biliary atresia is important, because
biliary atresia requires early surgical intervention
to preventbiliary cirrhosis, whereas neonatal hep-
atitis is managed medically. Surgical treatment
varies with the level of obstruction [7,8]. When
there is extrahepatic biliary obstruction (15%–
25% of cases), a direct anastomosis between the
patentportionoftheextrahepaticbileductandin-
testine is performed. When there is intrahepatic Fig.2.Biliaryatresia,cordsign.Transversesonogram
biliary atresia, a Kasai hepatoportoenterostomy throughthe portahepatis shows an echogenic cord
(anastomosis of a segment of small bowel to the (arrowheads)anteriortotheportalvein(arrow),indi-
portal region) is performed [7,8,19]. The success cating fibrosis along the course of the common he-
rate of the Kasai procedure is inversely propor- paticduct.
tional to patient age. Bile flow can be re-estab-
lished in up to 90% of infants who are younger
Neonatal hepatitis syndrome
than 2 months of age at the time of hepatopor-
toenterostomyandinapproximately50%inthose Theneonatalhepatitissyndromeisthetermgiven
whoare2to 3months.The success ratedecreases tononspecifichepaticinflammation thatdevelops
to less than 20% when surgery is performed after secondarytoseveraldifferentcauses,including in-
90daysofagebecauseofthepresenceofcirrhosis fection(cytomegalovirus,herpessimplex,toxoplas-
[7–9]. Liver transplantation is often required in mosis,protozoa,syphilis),metabolicdefects(alpha
older infants and children who have intrahepatic 1-antitrypsin deficiency, galactosemia, glycogen
biliary atresia. storagedisease,tyrosinosis),andAlagillesyndrome.
A spectrum of findings maybe seen sonograph-
ically,reflectingtheunderlyinghistology.Theliver
sizeandparenchymalechogenicitymaybenormal
or increased [1]. The intrahepatic ducts are typi-
callynot dilated. The extrahepaticduct is typically
notvisualized.Aremnantoftheextrahepaticduct,
however, may be noted in the porta hepatis [20–
23].Thisremnant appears as atriangular or tubu-
lar echogenic structure just superior to the portal
vein bifurcation. This finding has been termed
thetriangularcordsignandcorrelateswithfibrous
tissue in the porta hepatis at histologic examina-
tion (Fig. 2). The sign is reliable for the diagnosis
of extrahepatic biliary atresia and has a specificity
approaching 100% and a sensitivity of approxi-
mately 85%.
Inbiliaryatresia,thegallbladderisusuallysmall
or absent (Fig. 3), although a normal-sized gall-
bladder may be seen when the atresia is distal to
the insertion of the cystic duct (approximately
10% of cases). The finding of a small gallbladder
(<1.5 cm in diameter) is nonspecific and may be
seenwithbiliaryatresiaorneonatalhepatitis.Con-
tractilityandchangesingallbladdersizeafteramilk Fig. 3. Biliary atresia. Transverse scan shows normal
feedingarerareinpatientswhohavebiliaryatresia parenchymal echogenicity. The gallbladder (arrow)
(<10%ofcases)[24,25]. issmall.Thecommonbileductwasnotvisualized.
434 Siegel
Additional imaging studies to differentiate
atresia and hepatitis
Hepatobiliaryscintigraphy
Because the sonographic findings of biliary atresia
andhepatitisoverlap,hepatobiliaryscintigraphyis
usuallyperformedtoassessthepresenceorabsence
ofbile excretioninto thebowel. Infantswhohave
biliary atresia less than 3 months of age usually
shownormalhepaticextractionoftracerbutnoex-
cretionoftheradionuclideintothesmallintestine
(Fig.5A),whereas infants older than3months of
age show decreased extraction of tracer and no
excretion into the bowel. In neonates who have
neonatal hepatitis, parenchymal extraction is
diminished but there is some excretion into the
Fig. 4. Neonatal hepatitis. Longitudinal sonogram
bowel(Fig.5B).
showsdiffuselyincreasedandcoarsenedechogenicity.
Thegallbladderissmallandfilledwithsludge(arrow). Thesensitivityandspecificityofscintigraphyfor
the diagnosis of biliary atresia in infants less than
3monthsofageisapproximately95%and80%,re-
Histologicexaminationshowsmultinucleatedgiant spectively.Thepresenceofsmallbowelactivityex-
cellswithhepaticparenchymaldisruptionandlittle cludes biliary atresia as the cause of jaundice.
bilewithinthebileductcanaliculi.Similartobili- Differentiationbetweenbiliaryatresiaandneonatal
aryatresia,thecauseisbelievedtobeaninuteroin- hepatisismoredifficultwhenthereispoorhepato-
flammatoryprocessandthediseaseprocessusually cellularfunction.
manifestswithjaundiceat3to4weeksoflife.
At sonography, the liver size and echogenicity
maybe normal or increased, and the biliary ducts
Magneticresonance imaging
arenot dilated[1,2](Fig.4).The gallbladdermay
MR cholangiopancreatography may also be useful
be small, normal, or increased in size. Changes in
in assessing the patency of intra- and extrahepatic
gallbladdersizeafteramilkfeedingcanoccurinpa-
biliary ducts [10,12]. Complete visualization of
tients who have neonatal hepatitis, reflecting pa-
theextrahepaticbiliarysystemexcludesbiliaryatre-
tency of the common hepatic and common bile
siaasthecauseofcholestasis[10].
duct[24].
Fig.5.Hepatobiliaryimaginginneonataljaundice.(A)Biliaryatresia.Hepatobiliaryscanobtained6hoursafter
injectionofTc-99mdisofenindemonstrateshepaticuptakebutabsenceofexcretionintothecentralbileducts
andintestine.(B)Neonatalhepatitis.Hepatobiliaryscanobtained3hoursafterinjectionshowsradioactivityin
thegallbladder(*)andwithinbowel(arrows).Onmoredelayedimages,therewaspoorclearanceofradioac-
tivityfromtheliver.
JaundiceinInfants&Children 435
Cholangiography multipleintrahepaticbiliarycystsandisconsidered
Cholangiographyisperformedwhenotherclinical to be a separate disorder (see later discussion).
orimagingfindingssuggestthediagnosisofbiliary Choledochal cysts in neonates and young infants
atresia.Itmaybeperformedpercutaneously,endo- maycoexistwithbiliaryatresia[17,18].
scopically,orintraoperatively.Contrast mediumis At sonography, the choledochal cyst appears as
injectedintothegallbladder. a fluid-filled cysticmass in the region of the porta
hepatis that is separate from the gallbladder
(Fig.6).Intrahepaticbiliaryductdilatationispres-
Alagille syndrome
ent in approximately half of affected patients and
Alagille syndrome (also known as arteriohepatic typicallyislimitedtothecentralportionsoftheleft
dysplasia)isahereditarydisorder,usuallyanauto- andrightmainhepaticducts.Generalizedductaldi-
somal dominant trait with variable penetrance latation,typicalofacquiredobstruction, isabsent.
[8,26].Adeletionintheshortarmofchromosome The cysts tend to be smaller and ductal dilatation
20hasbeenseeninsomepatients[26].Itisassoci- isabsentwhenthere isconcomitant biliaryatresia
ated with abnormalities of the liver (cholestatic [17,18]. Complications associated with choledo-
jaundice), heart (most commonly peripheral pul- chal cysts include cholelithiasis, choledocholithia-
monic stenosis), skeleton (butterfly vertebrae and sis, ascending cholangitis, intrahepatic abscesses,
hemivertebrae), eye, kidneys, and abnormal facies biliary cirrhosis, portal hypertension, and hepato-
(frontal bossing, deep-set eyes, bulbous tip of the biliary malignancy, usually adenocarcinomas. The
nose, and pointed chin). The associated findings riskformalignancyincreaseswithage[27].
help to distinguish Alagille syndrome from biliary When acholedochal cystis demonstrated sono-
atresia. Patients typically present with jaundice in graphically, scintigraphy with hepatobiliary agents
theneonatalperiod.Histologicexaminationshows is performed to confirm that the cystic mass com-
paucity and hypoplasia of the interlobular bile municateswiththebiliarysystem.PreoperativeCT
ducts. Imaging findings are similar to those de- isacquiredtofurtherdefinetheanatomyofthein-
scribedforneonatalhepatitis. trahepatic biliary tree and the distal common bile
duct[13].MRcholangiographymayalsobeuseful
in the preoperative anatomic assessment of these
Choledochal cyst
lesions[10–12].
Choledochal cyst is a congenital dilatation of the
commonbileduct,with30%ofcasesfoundtooc-
Spontaneous perforation
cur in the first year of life, 50%between 1 and 10
of the extrahepatic bile ducts
yearsofage,and20%intheseconddecadeorlater
[27]. The classic clinical presentation is jaundice, Spontaneous perforation of the extrahepatic bile
abdominal pain, and mass, although this triad is ducts is a cause of neonatal jaundice and ascites,
present in only 20% to 50% of patients [27]. This usually affecting infants between 1 week and 4
abnormalityisbelievedtobetheresultofanabnor- monthsofage.Theclinicalfindingsincludeascites,
mal insertion of the common bile duct into the mildjaundice,failuretothrive,andabdominaldis-
pancreatic duct, which allows reflux of pancreatic tension. The serum bilirubin level is elevated,
enzymes into the biliary system. This reflux re- whereas other liver function tests are normal. The
sultsinachemicalcholangitis,whichweakensthe latterfeatureishelpfulindifferentiatingperforation
walls of the bile duct, eventually leading to ductal from neonatal hepatitis and biliary atresia, which
dilatation[28]. have similar clinical findings but abnormal liver
Four types of choledochal cysts have been de- functiontests.Themostfrequentsiteofperforation
scribed [29]. The type 1 cyst, accounting for 80% isthejunctionofthecysticandcommonbileducts.
to 90%of cases,is subdivided into type 1A, cystic Rarely the perforation involves the common he-
dilatationofthecommonduct;type1B,focalseg- paticduct,gallbladder,orjunctionofthecysticduct
mentalcommonductdilatation;andtype1C,fusi- andgallbladder[30].
formdilatationofthecommonbileduct.Thetype Sonographyshowsgeneralizedascitesoralocu-
2cyst,accountingforapproximately2%ofcases,is lated fluid collection in the porta hepatis [30]
atruediverticulumarisingfromthecommonduct. (Fig. 7). Echogenic debris or fine septations may
Thetype3cyst,accountingfor1%to5%ofcases,is be present within the ascitic fluid. The biliary tree
acholedochoceleinvolvingonlytheintraduodenal isnotdilatedbecauseitisnotobstructed.Gallblad-
portion of the duct. The type 4 cyst is subdivided der or distal common duct calculi may be associ-
intotype4A,multipleintrahepaticcystsandanex- ated findings. Hepatobiliary scintigraphy is useful
trahepatic cyst, and type 4B, multiple extrahepatic toconfirmthediagnosisbyshowingleakingofra-
cysts.Thetype5cyst,orCarolidisease,consistsof dioactive tracer into the peritoneal cavity. Surgical
436 Siegel
Fig.6.Choledochalcystinayoungboywithjaundice.(A)Longitudinaland(B)transversesonogramsthrough
theliverdemonstrateacysticmass(C),representingthecholedochalcyst,intheportahepatisseparatefrom
thegallbladder(GB).P,pancreas.(C)Contrast-enhancedCTscanconfirmsthecysticmass(C),whichisthedilated
commonbileduct.
placementofadrainagetubeintheareaofperfora- cyst(seeearlierdiscussion)andCarolidisease,dis-
tionusuallyresultsinspontaneousclosure. easesofthehepatocytes,andinflammatoryandob-
structivelesionsofthebiliaryducts.
Inspissated bile syndrome
Theinspissatedbileorbile-plugsyndromerefersto Caroli disease
anextrahepaticobstructionofthebileductsbybil-
Carolidisease,alsoknownascongenitalcysticdila-
iarysludge[2].Thisconditiontypicallyaffectsfull-
tionoftheintrahepaticbiliarytract,hastwoforms.
term infants. Inspissated bile syndrome has been
Oneformischaracterizedbysegmental,sacculardi-
associatedwithmassivehemolysis,hemorrhage,to-
lation of the intrahepatic bile ducts, an increased
talparenteralnutrition,cysticfibrosis,andvarious
frequency of calculus formation and cholangitis,
intestinaldiseases(Hirschsprungdisease,intestinal
and the absence of cirrhosis and portal hyperten-
atresias, and stenoses). Sonographyshows moder-
sion.Theotherformischaracterizedbyhepaticfi-
ately or highly echogenic bile within the gallblad-
brosis, cirrhosis, and portal hypertension. Both
der and often within dilated intra- or extrahepatic
forms of Caroli disease are associated with renal
bile ducts. Although the bile is echogenic, it does
cysticdisease,includingrenaltubularectasia(med-
notcauseacousticshadowing.Theductaldilatation
ullaryspongekidney),corticalcysts,andautosomal
maybedifficulttorecognizeiftheechogenicityof
recessivepolycysticdisease.PatientswhohaveCar-
theinspissatedbileandliveraresimilar[1,2].
olidisease,likethose whohavecholedochalcysts,
haveanincreasedriskfordevelopingcholangiocar-
cinoma. Patients may present in the neonatal pe-
Jaundice in older infants and children
riod [31], but the vast majority present as young
Thecausesofjaundiceinolderchildrenandadoles- adults who have abdominal pain, fever, and jaun-
centsincludecysticdiseases,includingcholedochal diceorwithportalhypertension.
JaundiceinInfants&Children 437
Fig.7.Spontaneousperforationofthecommonbileduct.(A)Transversesonogramthroughtheupperabdomen
demonstratesascites(A)intheperihepaticspace.(B)Onamorecaudadimage,aloculatedfluid(F)collection
andacalculus(arrow)arenotedintheportahepatis.
Sonography shows multiple dilated tubular Byler disease
structures,typicalofbiliaryradicals(Fig.8).These
Bylersyndrome(alsoknownasprogressivefamilial
can converge, creating larger saccular areas [31].
intrahepaticfibrosis)isafamilialintrahepaticcho-
The portal radicals may be partially or completely
lestatic syndrome that is associated with cystiche-
surroundedbythedilatedducts(termedthecentral
patic lesions and jaundice. Histologically, there is
dotsign)[32](Fig.9).Theextrahepaticbileducts
periportal fibrosis, micronodular cirrhosis, and
canbenormal,narrowed,orassociatedwithachol-
periductal cysts. Symptoms, including jaundice,
edochal cyst. Findings of portal hypertension may
pruritus, and hepatomegaly, usuallyappear bythe
beobservedinpatientswhohavehepaticfibrosis.
endofthefirstyearoflife.Thesonographicfindings
Fig.8.Carolidisease.(A)TransverseDopplersonogramshowsdilatationoftheintrahepaticbileducts(arrows),
whichconvergetowardtheportahepatis.ThecolorDopplerimagehelpsconfirmtheabsenceofflowinthe
dilatedducts.Flowis seenin theportalvein(PV).(B)CTconfirmssacculardilatationofthebileducts.(From
SiegelMJ. Gallbladder andbiliary tract.In: SiegelMJ,editor.Pediatricsonography. 3rdedition.Philadelphia:
LippincottWilliams&Wilkins;2002.p.276–304;withpermission).
438 Siegel
Fig.9.Carolidisease.Transversesonogramshowsdi-
lated ducts (arrows) that completely envelope the Fig.10.Acutehepatitis.Starryskyliver.Sagittalsono-
portalradicals.Thisappearanceistermedthecentral gramofthelivershowsbrightlyechogenicportalve-
dotsign. noustriads.Theliverwasalsomoderatelyenlarged.
aremultiplesaccularcysticlesions,someofwhich Inflammatory diseases of the biliary ducts
may contain echogenic portal veins (the central
Sclerosingcholangitis
dotsign)[33].UnlikeCarolidisease,thecystsinBy-
Sclerosingcholangitisisachroniccholestaticdisor-
lerdiseasedonotcommunicatewiththebileducts.
der characterized by inflammatory obliterative fi-
brosis of the extrahepatic and intrahepatic bile
ducts leading to biliary cirrhosis and ultimately
Hepatocellular diseases liver failure [34]. This entity has been associated
with chronic inflammatory bowel disease, Langer-
Hepatocellular disease can be classified into two
hanshistiocytosisX,andimmunodeficiencydisor-
majorclasses:infectious(acuteandchronichepati-
ders [34]. Histologic examination shows multiple
tis)andnoninfectious(metabolicdisorders,drugs,
segmentalstrictures,diverticulaformationbetween
toxins, and autoimmune diseases). The sono-
areasofstricture,andmuralthickeningofthebile
graphicappearanceoftheliverdependsonthese-
ducts. Clinical manifestations include jaundice
verity of the insult, rather than on the causative
and right upper quadrant pain. Most affected pa-
agent [1]. Sonography is usually normal in cases
tientsareadolescentsoradults.
of mild acute infectious hepatitis. Sonographic
findings in severe acute hepatitis include hepato-
megaly, decreased parenchymal echogenicity, and
increased echogenicity of the portal venule walls
(starry sky liver) (Fig. 10). The gallbladder wall
maybesmall,thick-walled,andfilledwithintralu-
minal sludge. In chronic active hepatitis, the liver
oftenappearsheterogeneousandhyperechoicwith
irregularmarginsanddecreasedvisualizationofthe
portal venous radicles (Fig. 11). The gallbladder
may be small and contain thick bile, sludge, or
stones, and collateral vessel formation may be
noted.
Metabolic causes of jaundice include Wilson
disease, cystic fibrosis, glycogen storage disease,
tyrosinemia, and a -antitrypsin deficiency. The
1
sonographic appearanceof these disorders is non-
specific and can be similar to that of acute or
chronic hepatitis. A definitive diagnosis requires
correlation with clinical information and labora- Fig.11.Chronichepatitis.Longitudinalsonogramof
tory results, and in many cases biopsy is needed thelivershowsanenlargedliverwithirregularmar-
toconfirmthediagnosis. ginsanddiffuselycoarseechotexture.