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Reference: GorNV,LevyRM,AhnJ,et al. Biliarycastsyndrome following liver transplantation: predictive factors andclinical outcomes.
LiverTranspl2008;14(10):1466–1472.
15.AnswerB.Astrongreflectorlocatedoutsidethemainultrasoundbeammaygenerateechoesthatare
detectable by the transducer.These echoes are falsely displayed as having originated from within the
mainbeam.Thisartifactis knownas the side lobe artifact.It is morelikelytoberecognizedwhen the
misplaced echoes overlap a structure that is normally anechoic, such as the gallbladder.Therefore, in
imaging of the gallbladder, which is normally anechoic, the side lobes can produce an artifactual
appearanceofsludge.
References: BushbergJT,SeibertJA,Leidholdt EM. Theessentialphysicsofmedicalimaging,3rded.Philadelphia,PA: Wolters Kluwer
Health/LippincottWilliams&Wilkins,2011:566–567.
FeldmanMK,KatyalS,BlackwoodMS.USartifacts.RadioGraphics2009;29(4):1179–1189.doi:10.1148/rg.294085199.
16.AnswerB.Theultrasoundimageisoftherightupperquadrantshowingmirrorimageartifact.Liver
parenchymaisshown bothbelowandabovethe diaphragm.Mirrorimageartifacts aregeneratedby the
false assumption that an echo returns to the transducer after a single reflection. In this scenario, the
primary beam encounters a highly reflective interface. The reflected echoes then encounter the “back
side” ofastructureand arereflectedbacktowardthereflective interface beforebeing reflected tothe
transducer for detection. The display shows a duplicated structure equidistant from but deep to the
stronglyreflectiveinterface.
Gasisthebestacousticmirrorinthebodybecauseitreflectsalmost100%oftheultrasoundbeam.In
rightupperquadrantUS,thebaseoftherightlungactsasanacousticmirror.Itformsamirrorimageof
the liveranddiaphragm. The tracheais anotherstructurewith alargesmoothgas interface.It therefore
actsasamirroronscansoftheneck.
References:FeldmanMK,KatyalS,BlackwoodMS.USartifacts.RadioGraphics2009;29(4):1179–1189.
HertzbergBS,MiddletonWD.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:20–22.
17a.AnswerC.Theultrasoundimageshowsmultiplecoarseshadowingcalcifications.Atleasttwoof
thesecalcificationsareshowntobewithinatubularanechoicstructure(bileduct).TheCTimageshows
severalcysticliverlesions,manywithcentralintraluminalfibrovascularbundlescorrespondingtoportal
vein radicals. Many cystic spaces also contain coarse calcifications. These imaging findings are
characteristicofCarolidisease.
Carolidiseaseisalsoknownascommunicatingcavernousectasiaoftheintrahepaticbileductsandis
anautosomalrecessivedisorder.Itresultsfromthearrestoforaderangementinthenormalembryologic
remodelingofductsandcausesvarying degreesofdestructiveinflammationandsegmentaldilatation.If
thelargeintrahepaticbileductsareaffected,theresultisCarolidisease,whereasabnormaldevelopment
ofthesmallinterlobularbileductsresultsincongenitalhepaticfibrosis.Ifalllevelsofthebiliarytreeare
involved,featuresofbothcongenitalhepaticfibrosisand Caroli diseasearepresent.Thisconditionhas
beentermedCarolisyndrome.Carolidiseasetypicallymanifestsassaccularorfusiformcysticdilatations
oftheintrahepaticbileductsupto5cmindiameter,oftencontainingcalculiorsludge.
Autosomal dominant andautosomal recessive polycystic kidney, as well as medullary sponge and
medullary cystic kidney, can be seen in association with Caroli disease. Renal cysts are seen with
disordersofthe ductalplate,andrenaldevelopmentalabnormalitiescanbecausedbythesamegenetic
determinants.
References:HertzbergBS,MiddletonWD.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:99–100.
LevyAD, Rohrmann CA, Murakata LA, et al. Caroli’s disease: radiologic spectrum with pathologic correlation. AJR Am J Roentgenol
2002;179(4):1053–1057.
SantiagoI,LoureiroR,Curvo-SemedoL,etal.CongenitalcysticlesionsoftheBiliarytree.AJRAmJRoentgenol2012;198(4):825–835.
17b.AnswerD.Thepresenceofportalradiclespartiallyorcompletelysurroundedbydilatedbileducts
(knownasthecentral-dotsign)isconsideredcharacteristicofCarolidisease.Ultrasoundmayalsoshow
dilatedintrahepaticbileductswithintraductalcalculi.Echogenicseptamaytraversethelumensofdilated
bileducts,anappearancetermedintraductalbridging.
Reverse target sign (answer choice A) is described in hepatic cavernous hemangiomas due to a
hypoechoiccenterandahyperechoicperiphery.
Clusterofgrapessign(answer choiceB) is described inpyogenicliverabscesses.Small pyogenic
abscessesoftheliver,mergingintoalargecavity,formanimagesimilartoabunchofgrapes.
Water-lily sign (answer choice C) is characteristic of echinococcal infections when there is
detachmentoftheendocystmembrane,whichresultsinfloatingmembraneswithinthepericystthatmimic
theappearanceofawaterlily.
Reference:VachhaB,SunMRM,SiewertB,etal.Cysticlesionsoftheliver.AJRAmJRoentgenol2011;196(4):W355–W366.
17c.AnswerB.
Reference:HertzbergBS,MiddletonWD.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:99–100.
18.AnswerA.Theultrasoundimagesshowalargeirregularhypoechoiclesionintherighthepaticlobe
with irregular wall and septations. There is increased through-transmission indicating cystic/liquefied
internalcontents.Thereissomebloodflowin theperipheryofthe lesion, butnobloodflowwithin the
lesion. These imaging findings along with the provided clinical history are strongly suggestive of a
pyogenicliverabscess.
Pyogenic liver abscess secondary to appendicitis, diverticulitis, or other intra-abdominal infective
processeshasdecreaseddramaticallybecauseofimprovementsinthetreatmentoftheprimarycondition,
whichtypicallyincludessourcecontrol andearly initiation ofantibiotics. Nonetheless,thesediagnoses
stillaccountforapproximately20% ofcases ofpyogenic liverabscess. Biliary obstruction (benignor
malignant), stenting, orinstrumentation is nowa more commoncause.Hematogenousspread fromother
sources,suchasbacterialendocarditisandintravenousdrugabuse,canalsoresultinformationofliver
abscess.
Antibiotics and ultrasound or CT-guided drainage are the mainstays of therapy for pyogenic liver
abscess. Ultrasound or CT-guided percutaneous drainage of abscesses is usually safe and effective.
Drainagecathetersareleftinplaceuntilthecollectioniscompletelyevacuated,asdeterminedbyserial
imagingstudiesandthepatient’sclinicalcourse.
Imaging-guided biopsy (answer choiceB)wouldbeindicatedifthiswasa solidlesion,butpatient
historyandimagingcharacteristicsofthelesionpointtowardabscess.Ifindoubt,anaspirationfollowed
bydrainagecanbeperformed.LiverprotocolMRI(answerchoiceC)wouldbeusefultocharacterizean
indeterminatesolid liver lesion. Surgery (answer choice D) is reserved for cases where percutaneous
abscessdrainageisunsuccessfulorinpatientswhohavecoexistentintra-abdominaldiseasethatrequires
operativemanagement.
References:HertzbergBS,MiddletonWD.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:66–68.
RallsPW.Focalinflammatorydiseaseoftheliver.RadiolClinNorthAm1998;36(2):377–389.
Reid-LombardoKM,KhanS,SclabasG.Hepaticcystsandliverabscess.SurgClinNorthAm2010;90(4):679–697.
19.AnswerD.Accordingtothereportpublishedin1999fromtheInstituteofMedicineentitled“ToErr
Is Human: Building a Safer Health System,” medical errors were defined as the failure of a planned
actionto be completedas intended or the use of a wrong plan toachieve anaim. Medical errors are
multifactorial, and most were felt to be system errors rather than individual problems. Errors can be
classifiedinto oneoffour maincategories: (1)diagnosticerrors, (2)treatmenterrors,(3)preventative
errors,and(4)othererrors.Thescenariodescribedinthevignettebestfitsintotwomaincategoriesof
medicalerror.Equipmentfailurefallsinto the “other error”category becauseoftheretractorbreakage.
There is no reasonto believe that the surgeon was straying from standard surgical procedure (answer
choiceAisincorrect).Theothermainsourceoferroriscausedbyamissedsurgicalforeignbodyonthe
closingfilms.Althoughtheimagesweresuboptimalandthefindingwasattheedgeofthefilm,theforeign
body could be seen when the viewing parameters of the film were optimized. Repeat films can be
requestedif necessary, but that is at the discretionof the radiologistand clinicians.The surgical team
would not have known where the foreign bodies were. Answer choices B and C are not the best
selections.
Reference: Diagnostic Radiology: Core Quality and Safety Study Guide manual on patient safety. Tucson,AZ: American Board of
Radiology,2015:5.
20a. Answer C. Ultrasound images show a round lesion in the right hepatic lobe with a “target”
appearance.Thelesionhasanechogeniccenterwithathickhypoechoichalo.Thisultrasoundappearance
isstronglysuggestiveofmalignancy.Inacirrhoticpatient,thelesionshouldbeconsideredhepatocellular
carcinoma (HCC) until proven otherwise. Further characterization was performed with MRI using a
liver-specificprotocol, whichreveals arterial phase hyperenhancement andwashout onthe delayed5minutepostcontrastimage.Theseimagingfeaturesarediagnosticofhepatocellularcarcinoma.
Preferential arterial blood supply is one of the hallmarks of HCC. Therefore, arterial phase
hyperenhancement isthe single most important imaging feature of HCC. Thewashoutfeature onportal
venous phase has been attributed to the diminished portal venous supply of HCC compared with the
surroundingliver.
Reference:BashirMR,HussainHK.Imaginginpatientswithcirrhosis.RadiolClinNorthAm2015;53(5):919–931.
20b.AnswerE.Theliverlesionshownhereis>20mminsizeandshowsarterialhyperenhancementas
wellas delayedwashout.AccordingtotheACRLI-RADSv2017 forCTandMRI, thiswouldbeaLIRADS5lesion.
Reference:AmericanCollegeofRadiology.LiverImagingReportingandDataSystemversion2017.
20c. Answer D.According to the ACR LI-RADS v2017 lexicon, threshold growth is defined as a
minimum increase in nodule diameter of 0.5 cm in addition to either at least 50% diameter increase
within6monthsoratleast100%diameterincrease peryear.Newlesionsmeasuringatleast1 cmthat
werepreviouslynotseenonCTorMRIwithinthepast2yearsarealsoconsideredthresholdgrowth.
Reference:AmericanCollegeofRadiology.LiverImagingReportingandDataSystemversion2017.
21.AnswerC.USandCTimagesshowmacronodularappearanceoftheliverwithareasofcapsular
retraction,heterogeneousparenchyma,traceascites,andmildsplenomegaly. Ina patient withhistoryof
metastaticbreastcancer,this imagingappearancecanbeseenfollowingchemotherapyandisdescribed
as “pseudocirrhosis.” The pathogenesis has been proposed to be related to nodular regenerative
hyperplasiacausedbychemotherapy-inducedhepaticinjuryresultingincapsularretraction, decreasein
hepatic volume, and caudate lobe enlargement. Findings of portal hypertension such as ascites and
splenomegalymaybealsoseen.
Reference: Viswanathan C, Truong MT, Sagebiel TL, et al. Abdominal and pelvic complications of nonoperative oncologic therapy.
RadioGraphics2014;34(4):941–961.
22. AnswerD. Ultrasoundimageshowsalargelobulatedhypoechoic andheterogeneousmassin the
medial segment of the left lobe. CT image confirms the finding and also raises suspicion for central
necrosis.A focusof calcificationisalso seen in themass. Thereis overlying capsular distortion, and
smallamountofascitesispresentanteriortotheliver.Additionally,bulkyenlargedportahepatislymph
nodesareshown,stronglysuggestingamalignantprocess.Inayoungpatientwithnopriorliverdisease,
themostlikelydiagnosiswouldbefibrolamellarcarcinoma.
Fibrolamellar carcinoma is a variant of hepatocellular carcinoma seen in young patients usually
without previousliverdisease. Patientsmay present with abdominal pain,hepatomegaly, andpalpable
mass. Gynecomastia and venous thrombosis may be seen in some cases. Gynecomastia results from
conversionof circulating androgens toestrogens bythe enzyme aromatase, whichis elaboratedby the
malignanthepatocytesoffibrolamellarcarcinoma.Incontrasttohepatocellularcarcinoma,serumalphafetoproteinisgenerallynotelevated.
Giant cavernous hemangioma (answer choice A) can have a central scar or necrosis and may
occasionallyhave central calcifications. The enhancement pattern of hemangiomas tends to follow the
blood vessels during all phases of enhancement and is peripheral, nodular, and discontinuous, with
eventualfilling-inondelayedphaseimages.Bulkylymphadenopathyandascites,asinthiscase,willnot
beseen.
Focalnodularhyperplasia(FNH)(answerchoiceB)hasafemalepredominance,isusuallyisodense
totheliveronportalvenousphase,andrarelyhascalcifications.Moreover,bulkylymphadenopathywill
notbeassociatedwithFNH.
HCC (answer choice C) is primarily seen in the adult population and in those with chronic liver
disease. Serum alpha-fetoprotein is generally elevated. Venous invasion can be seen in large or
infiltrativeHCC.
References:LewisRB,LattinGE,MakhloufHR,etal.Tumorsoftheliverandintrahepaticbileducts:radiologic–pathologiccorrelation.Magn
ResonImagingClinNAm2010;18(3):587–609.
McLarney JK, Rucker PT, Bender GN, et al. Fibrolamellar carcinoma of the liver: radiologic–pathologic correlation. RadioGraphics
1999;19(2):453–471.
23. Answer D. Ultrasound images show a nondependent, nonshadowing polypoid lesion in the
gallbladder with internal vascular flow. A large right adrenal mass is also shown in keeping with
providedclinicalhistoryofmultiorganmetastases.Inapatientwithmetastaticdisease,asofttissuemass
inthe gallbladder isstronglyconcerningfor melanoma metastasis. Usuallyotherabdominal metastases
willalsobepresentsuchasintheliver,adrenalglands,lymphnodes,etc.
Malignantmelanomaisthemostcommoncauseofmetastatictumorsofthegallbladder,accountingfor
more than 50% cases of all gallbladder metastases. The exact mechanism is not clear, but it may be
because of the rapid hematogenous spread of melanoma. Other primary tumors, such as renal cell
carcinoma,mayalsometastasizetothegallbladderhematogenously.Advancedhepatocellularcarcinoma
canlocallyextendandinvadethegallbladder.Cholesterolpolypsandadenomasalsopresentaspolypoid
lesionswithinthegallbladder,buttheyareusuallymuchsmallercomparedtomalignantlesions.
References:HertzbergBS,MiddletonWD.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:45.
MartelJ-P,McLeanCA,RankinRN.Melanomaofthegallbladder.RadioGraphics2009;29(1):291–296.
24.AnswerC.TheACRAppropriatenessCriteriaareagroupofdocumentsdevelopedbytheAmerican
College of Radiology (ACR), whose primary purpose is to “assist referring physicians in making
appropriateimagingdecisionsforgivenpatientclinicalconditions.”Currently,thesecriteriaarethemost
comprehensiveevidence-based guidelinesfordiagnosticimaging selection, radiotherapy protocols, and
image-guidedinterventionalprocedures.Theyembodythebestcurrentevidenceforselectingappropriate
diagnosticimagingandinterventionalproceduresfornumerousclinicalconditions.
Reference:AmericanCollegeofRadiology.2017ACRAppropriatenesscriteria.
25.AnswerA.ColorandspectralDopplerimagesshowabsenceofflowintherightandmiddlehepatic
veins. There is abnormal faint monophasic flow in the inferior vena cava (IVC). The caudate lobe is
markedlyenlarged.Thereissmallascites.Allthesefindingstogetherwiththeclinicalpresentationin a
youngfemalepatientaremostsuggestiveofBudd-Chiarisyndrome(BCS).
Budd-Chiari syndrome is caused by obstructed hepatic venous outflow, resulting in progressive
hepaticfailure,ascites,andportalhypertension.Theobstructioncanbeanywherefromthesmallhepatic
veins to the junction of the IVC and the right atrium. Hepatic venous outflow obstruction results in
increaseofsinusoidal pressureanddiminishedportalvenousflow,resultingincentrilobularcongestion
andultimatelynecrosisandatrophy.
Causes of BCS include hypercoagulable states in young women on oral contraceptives, trauma,
pregnancy, extension of tumor into hepatic veins, etc. US findings include presence of ascites and
enlarged caudate lobe. The emissary veins from the caudate lobe drain directly into the IVC. This
increasedbloodflowthroughthecaudatelobeleadstoenlargement.BloodflowinhepaticveinsandIVC
canbemonophasic,reversed, or absent. Theportal veinmayalso beaffectedandshoweither slowor
reverseflow.
RightheartfailurewilltypicallyshowdilatedIVCandhepaticveins.Therefore,answerchoiceBis
incorrect. Acute hepatitis may show decreased echogenicity of the liver parenchyma, accentuated
brightnessoftheportaltriads,hepatomegaly,andgallbladderwallthickening.Itwouldnotbeexpectedto
show hepatic vein thrombosis as in this case. Therefore, answer choice C is incorrect. In primary
sclerosingcholangitis(PSC),thereareirregularlydistributedmultifocalbileductstricturesofintra-and
extrahepatic bile ducts. However, because of the sclerotic nature of PSC, marked dilatation of the
intrahepatic ducts may be absent. The intrahepatic ducts are frequently not visualized on US. Diffuse
thickeningofthecommonhepaticandcommonbileductmaybeseenonUS.Therefore,answerchoiceD
isincorrect.
Reference: Rumack CM, Wilson SR, Charboneau WJ. Diagnostic ultrasound, 4th ed. Philadelphia, PA: Elsevier Health Sciences,
2011:104–107.
26.AnswerB.Theultrasoundimagesshowadistendedgallbladderfilledwithmultiplegallstones.The
gallbladderwallisthickenedandstriated.Therearefocalareasofmucosalulcerationwithsmallamount
ofadjacent pericholecysticfluid/abscess. The thirdimageshows sloughingofthemucosal membranes.
Thesefindingsaresuggestiveofgangrenouscholecystitis.
Gangrenouscholecystitisisasevereadvancedformofacutecholecystitis.Itisbelievedtoresultfrom
cysticductobstruction,leadingtomarkeddistensionofthegallbladderandultimatelyischemicnecrosis
ofthe wall.Gangrenouscholecystitisisassociatedwithsignificantly increased morbidity andmortality
andusuallyrequiresemergentsurgery.
On ultrasound, there is heterogeneous or striated thickening of the gallbladder wall likely from
ulceration,hemorrhage,necrosis,ormicroabscessesinthegallbladderwall.Thepresenceofintraluminal
membranes, whichrepresentdesquamated gallbladder mucosa, may be seen. Murphy sign is absent in
two-thirdsofpatientsbecauseofnecrosisofthenervesupplytothegallbladder.Intramuralabscessesor
pericholecysticfluidcollectionorabscesscausedbyassociatedgallbladderperforationmaybeseen.
Uncomplicatedacutecholecystitis(answerchoiceA)wouldnotbeexpectedtocausethesonographic
findings of desquamated and ulcerated gallbladder mucosa as in this case. Moreover, sonographic
Murphy sign would also be expected to be positive in acute cholecystitis. In acute hepatitis (answer
choiceC), there canbe diffuse gallbladderwallthickening but without gallbladderdistension.Nosoft
tissuemassisshowninthiscasetosuggestgallbladdercancer(answerchoiceD).
References: Bennett GL, Balthazar EJ. Ultrasound and CT evaluation of emergent gallbladder pathology. Radiol Clin North Am
2003;41(6):1203–1216.
RumackCM,WilsonSR,CharboneauWJ.Diagnosticultrasound,4thed.Philadelphia,PA:ElsevierHealthSciences,2011:205.
27.AnswerA.Ultrasoundimagesshowmarkedintrahepaticbiliaryductaldilatation.Intraluminalmass
is present in the proximal common bile duct up to the level of the biliary confluence. The imaging
appearanceismostconsistentwithandconcerningforcholangiocarcinoma.
Cholangiocarcinomas are malignant tumors arising from the biliary tract. Primary sclerosing
cholangitisisthemostcommonriskfactorforcholangiocarcinomaintheUnitedStates.Liverflukesand
hepatolithiasis are common risk factors in eastern Asia. Based on location, they are divided into
intrahepatic(about 10%), hilar(about 60%), anddistal(about30%)types.Hilar cholangiocarcinomas
are also called Klatskin tumors. Based on morphologic classification, they are classified into massforming,periductalinfiltrating,andintraductalgrowthtypes.
Cholangiocarcinomamorecommonlycausesbiliaryobstruction than does hepatocellular carcinoma
(answerchoiceB).Metastasestobileductscan(answerchoiceC)mimiccholangiocarcinoma,affecting
both the intrahepatic and extrahepatic ducts. History of malignancy and presence of multiple lesions
wouldhelp inmaking thatdiagnosis. Patientswith choledocholithiasis (answerchoice D)presentwith
rightupper quadrant or epigastric pain,nausea,andvomiting.Ultrasound may revealshadowingductal
calculi,whicharenotafindinginthiscase.
References: Chung YE, Kim M-J, Park YN, et al. Varying appearances of cholangiocarcinoma: radiologic–pathologic correlation.
RadioGraphics2009;29(3):683–700.
RumackCM,WilsonSR,CharboneauWJ.Diagnosticultrasound,4thed.Philadelphia,PA:ElsevierHealthSciences,2011:190–197.
28.AnswerD.Ultrasoundimageshowsacousticshadowingposteriortoacalcifiedgallstone.Acoustic
shadowingismainlycausedbysoundabsorption.Absorptionreferstothelossofsoundenergysecondary
toitsconversiontothermalenergy.Absorptionisgreatestinbone/calcification,followedbysofttissue,
followedbyfluid.
Reference:HertzbergBS,MiddletonWD.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:4.
29.AnswerB. Shadowingattheedges offluid-filledstructuresiscaused byrefraction. Refraction is
causedbythechangeindirectionofthetransmittedultrasoundbeamatatissueboundarywhenthebeam
isnotperpendiculartotheboundary.Itiscommonlyseenatfat–muscleandtissue–fluidinterfaces.
Reference:HertzbergBS,MiddletonWD.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:22.
30.AnswerB.Sagittalandtransverseimagesoftherighthepaticlobeshowahypoechoicliverlesion
withanechogenicrim.Thisisthe“reversetarget”appearanceandisknowntobequitecharacteristicof
cavernous hemangiomas. Although not very specific, posterior acoustic enhancement can be seen in
hemangiomas. Posterior acoustic shadowing (answer choice A) is not seen except in rare giant
hemangiomas, which may have central calcifications. Histologically, hemangiomas contain multiple,
small,blood-filledspacesseparatedbyfibrousseptationsandlinedbyendothelialcells.However,blood
flowinthesespacesistooslowtobedetectedwithDopplertechniques.Hemorrhage(answerchoiceC)
is not typical of hemangiomas. It can be seen in hepatic adenomas and hepatocellular carcinomas.
Because hemangioma are benign lesions, they would not be associated with a primary malignancy
(answerchoiceD).
Reference:HertzbergBS,MiddletonWD.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:54–57.
31.AnswerB.Theultrasoundimagesshowadilatedcommonbileductwithanechogenicfocuswith
posterior shadowing consistent with choledocholithiasis and intrahepatic biliary ductal dilatation. The
nextmostappropriateimagingtestinthisscenariowouldbeMRCP,whichcanconfirmthepresenceof
intraductalstones.MRCPisparticularlyhelpfulifthedistalcommonbileductisnotreliablyvisualized
onultrasound.
A HIDAscan(answerchoice A)couldbeuseful in anequivocal caseofacute cholecystitis. If the
pancreaticductis dilated,incombinationwith intrahepaticandextrahepaticbiliaryductaldilatation, it
would be concerning for a pancreatic head or periampullary mass. In that case, a pancreatic mass
protocol CT (answer choice C) would be indicated. Endoscopic ultrasound (answer choice D) with
tissuesamplingisindicatedifapancreaticmassisshownonimaging.
Reference:WilliamD,MiddletonBSH.Ultrasound:therequisites,3rded.Philadelphia,PA:Elsevier,2016:94–96.
2 Pancreas,Spleen,andBowel
Questions
1.Whichofthefollowingultrasoundartifactsisshown?
A.Reverberationartifact
B.Ring-downartifact
C.Comet-tailartifact
D.Twinkleartifact
2.Whichofthefollowinghasthehighestacousticimpedance?
A.Air
B.Fat
C.Muscle
D.Bone
3.Fresnelzoneis:
A.Thefarfieldoftheultrasoundbeam
B.Thenearfieldoftheultrasoundbeam
C.Anothernameforsidelobes
D.Anothernameforgratinglobes
4.Whichmaneuvershouldyouattemptfirsttoimprovevisualizationofthepancreasintheimageshown?
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