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13 Upper Abdominal US inNeonates, Infants andChildren: (Excluding the Kidneys)
Fig. 13.16 Liver calcication: (a) Supercial liver calcication with shadowing. (b) CDS shows
some twinkling artefact of subcapsular calcication
289
• May (must not!) twinkle on CDS.
• Single or multiple.
Intrahepatic Gas
Either in vasculature or bile ducts:
• In biliary system: usually ascends from duodenum (e.g. due to distal obstruction,
associated with bile duct pathology), may be associated with infection+secondary calcications, may also be transient without any sequelae.
• In vessels: gas bubbles commonly within PV system, derive from some condition in GI tract (e.g. necrotising enterocolitis, severe gaseous distention); may
also be idiopathic.
US and CDS Findings
Most commonly air/gas gathers in dependent areas (highest parts of liver—upper
ventral areas in supine position). Seen as echogenic foci (with comet-tail-like reverberation echoes), sometimes oating echogenic foci visualised in central PV
(Fig.13.17).
CDS (Fig.13.17b, c): multidirectional colour signals, similar to twinkling arte-
fact. Typical bidirectional spikes on spectral trace, helpful for DDx biliary versus
vascular air—intravascular if found within portal vein.
Note US—most sensitive method for detecting air, long before visualised on
plain lm. If found, should prompt thorough US investigation of GI tract. Finding
nonspecic (i.e. is not indicative, for example, for NEC in itself, may also be in
infantile colitis or gut obstruction with bowel distention)—diagnosis in clinical
context.
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M. Riccabona
ab
Fig. 13.17 Liver/portal venous gas: (a) Intrahepatic bright spots—in this case due to air in bile
ducts. (b) Severe portal venous gas in a neonate with NEC—note the bight echogenic spots
throughout the liver demonstrating gas in the peripheral portal vessels. (c) Air spikes in portal liver
ow spectra (due to NEC). (d) Bidirectional “Doppler noise” on spectral analysis—obviously not
in portal vein branches—thus aerobilia has to be suggested (note arterial hyperaemia)
c
d
Haemangioma
Not a single entity, different ages of manifestation, different tendencies for spontaneous regression:
• The classical small haemangioma (adult type, “cavernous” haemangioma—
remember new classication=venous vascular malformation)—benign condition.
Rarer in childhood, often starting from puberty. Really a venous malformation.
• The neonatal or infantile haemangioendothelioma/“infantile/congenital haemangioma (CH)” (GLUT1 positive or negative). May be small or large, may disappear (RICH—rapidly involuting CH) or stay/grow (NICH—non-involuting CH).
In large CH α-fetoprotein may be elevated, but usually normal. Rarely malignant
transformation into angiosarcoma may occur. New classication: infantile/congenital hepatic arteriovenous vascular malformation.
US Findings
Adult cavernous haemangioma—usually homogenous hyperechoic mass with welldened margins (Fig.13.18a, see also Fig. 4.8). Larger lesions may be more complex, contain calcications or central brosis, thrombosis, necrosis and degeneration.
Sometimes peripheral hypoechoic halo and acoustic enhancement.
• Infantile type haemangioma—usually small hypoechoic nodules, single or multiple, of varying size arise and grow after birth. CH=congenital haemangioma
are present at birth. May change size and echotexture, may even vanish (RICH).
The GLUT1 negative form is more consistent with a vascular malformation (not
a true congenital haemangioma), usually larger and more complex in appearance
(often called haemangioendothelioma—Fig. 13.18b–d).
CDS
Cavernous adult haemangioma: slow blood ow, some peripheral vascularisation
may be depictable, particularly using aCDS and CEUS.
Neonatal CH/haemangioendothelioma/haemangioendotheliomatosis (multiple/
numerous lesions throughout liver): high-blood ow with signicant shunt and
hypervascularity in periphery of lesions—large HA, tapering of abdominal aorta
13 Upper Abdominal US inNeonates, Infants andChildren: (Excluding the Kidneys)
291
distal to coeliac trunk. Large shunt may cause cardiac failure. Spectral analysis—
high-ow velocities with high-diastolic ow+low RI, potentially arterialisation or
signicantly increased ow in affected draining HV.Depending on size and vascularity, may demonstrate central vascularity, particularly using aCDS and CEUS (see
Fig. 4.7).
CEUS: typical IRIS-phenomena of slow centripetal enhancement, with sustained
enhancement in portal phase, as in CT or MRI (see Figs. 4.7 and 4.8).
Mesenchymal Hamartoma
Benign tumour, commonly in younger children. May have arteriovenous shunts,
may be pedunculated and secondarily undergo torsion. May be cystic, sometimes
similarities to/mimicking complex vascular/veno-lymphatic malformations.
Rare malignant transformation, may spontaneously regress.
US and CDS Findings
Typically well-circumscribed multilocular, sometimes nearly completely cystic
mass with smooth well-dened borders, anechoic and cystic spaces and echogenic
septae—very mixed US appearance (Fig. 13.15e). US is useful for depicting
tumours and follow-up; specic diagnosis difcult. Diagnosis sometimes made by
dynamic MRI (potentially also CEUS), eventually by biopsy/resection.
CDS shows vascularisation and reveals arteriovenous shunting if large feeding/
draining vessels (always conrm by spectral analysis).
DDx: Lymphangioma, broadenoma, complicated posttraumatic cysts, etc.
Focal Nodular Hyperplasia (FNH)
Rare in childhood, more commonly during puberty. Associated with oral contraceptive use, myelo- and lymphoproliferative syndromes, immune disorders, long-term
medication (particularly steroids and antineoplastic agents), rarely sporadic,
abc
de
Fig. 13.18 Liver haemangioma: (a) Adult-type echogenic liver haemangioma, with respective
CDS image (b). (c, d) Haemangioendothelioma/giant infantile haemangioma (RICH)—see also
chapter on CEUS.Central calcication (arrow) (e)
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M. Riccabona
additionally in Abernethy malformations, in children with hereditary haemorrhagic
telangiectasia, or after chemotherapy, etc.
Regenerative lesions in noncirrhotic liver.
US Findings
• Commonly multiple, well-dened, iso-, hypo- or even hyperechoic nodules
within normal parenchyma. Spherical to polygonal nodular structure of varying
size without capsule. Behaves like tumour/space-occupying lesion, may compress surrounding liver tissue causing pseudocapsule. May not be distinguishable from other masses.
• Central large vascular pedicle leading to central brous “scar”.
• Echogenicity: iso- or hypoechoic to liver, more easily seen by mass effect than
by its echogenicity (often subscapular—focal bump in liver surface) or in altered
liver parenchymal echotexture (e.g. fatty liver).
CDS
May reveal central scar, more readily appreciated by aCDS.
CEUS
Typical central spoke wheel pattern in early arterial phase by radial vessels, no portal/late phase enhancement (no/little enhancement of parenchyma in late phase), see
Table 4.2 in chapter on CEUS.
Hepatic Adenoma
Associated with glycogen-storage disease, Fanconi anaemia, galactosaemia, steroids, after chemotherapy.
US Findings
Usually solitary mass, well-circumscribed, encapsulated, iso- to hypoechoic, rarely
hyperechoic—with heterogeneous features in haemorrhage, glycogen or fat- storage.
Never contains central “vascular” scar.
CDS
May show peripheral, central or combined ow—with random stippled pattern.
Ce-US: better differentiation (by excluding FNH-typical central scar appear-
ance), demonstration of homogenous arterial phase enhancement with absence of
portal phase enhancement.
Fatty Tumours
Angiomyolipoma (in tuberous sclerosis), lipoma.
US Findings
Hyperechoic mass, varying degree of acoustic shadowing (Fig.13.19). Without
clinical history or other imaging (e.g. chemical shift MRI) not to be differentiated
from adult-type haemangioma.
cd
13 Upper Abdominal US inNeonates, Infants andChildren: (Excluding the Kidneys)
293
Hepatoblastoma
Most common malignant liver tumour in childhood—different microscopic entities.
Variable US appearance.
Associated with Beckwith–Wiedemann syndrome, hemihypertrophy syn-
dromes, etc.
Commonly metastasises to lung, brain and skeleton. Often large and asymptom-
atic at presentation, elevated α-fetoprotein levels. Vascular invasion common.
US and CDS Findings
Commonly large space-occupying lesion with inhomogenous echogenicity without
specic criteria (Fig.13.20a). Secondary regressive changes, haemorrhage, necrosis
and potentially calcications. Tend to compress surrounding structures. PV thrombosis and/or invasion of HV.
CDS nonspecic, commonly some large vessels with high-velocity ow.
CEUS
Marked early arterial enhancement (similarly to carcinoma) with quick washout and
no PV enhancement. Vascular invasion, disruption and irregular vascular architecture readily appreciated.
Fig. 13.19 Liver angiomyolipoma. Echoic liver
tumour in child with tuberous sclerosis,
consistent with a liver angiomyolipoma
ba
Fig. 13.20 Liver tumours: (a) Liver tumour (++) in a 3-year-old that was proven to be a hepato-
blastoma. Bicolour mode used to improve visualisation of subtle echogenicity differences even in
difcult scanning conditions. (b) Complex, partially cystic liver tumour in 9-year-old girl that
proved to be a liver sarcoma. Liver metastasis—typical appearance on grey scale US with numerous hypoechoic round lesions (c) and on CEUS (d), much more conspicuous; note the rapid washout in this image of the portal-venous phase
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M. Riccabona
Hepatocellular Carcinoma
Second most common liver malignancy, usually in older children, associated with
pre-existing liver disease (hepatitis B, glycogen-storage disease, tyrosinaemia, haemochromatosis, Wilson, α1-antitripsin-deciency, other forms of liver cirrhosis).
Elevated α-fetoprotein levels; rarely multifocal.
US and CDS Findings
Similar to hepatoblastoma. Typically a large mass, hyperechoic to normal liver—
with heterogeneous appearance, calcications or necrosis, even with hypoechoic
areas. Fibrous capsule causing hypoechoic rim may be present.
CDS similar to hepatoblastoma. Hypervascularity with high ow may be depicted.
CEUS
Marked early arterial enhancement (similarly to hepatoblastoma) with quick washout and no PV-phase enhancement. Vascular invasion, disruption and irregular vascular architecture readily appreciated.
• Fibrolamillar carcinoma (subtype): normal α-fetoprotein levels, usually solitary.
Otherwise nonspecic US ndings, not differentiable from classic hepatocellular
carcinoma or hepatoblastoma by US.US-guided biopsy may aid diagnosis.
Hepatic Sarcomas
Embryonal Cell Sarcoma
Undifferentiated, usually large tumour, also called malignant mesenchymoma or
hepatic mesenchymal sarcoma. Commonly in school age children.
α-fetoprotein normal.
US and CDS show unspecic, large, with cystic spaces+solid areas (Fig.13.20b).
Note Particularly large tumours with complex cystic spaces and septations must
raise suspicion.
Rhabdomyosarcoma
Rare tumour arising from muscle cells (bile ducts, etc.), commonly situated centrally.
US and CDS ndings unspecic. Large, usually hypoechoic, causing early sec-
ondary cholestasis due to its position. No other specic signs.
CDS is helpful to differentiate vessels from dilated bile ducts with potential
intraductal tumour growth and invasion. No particular value of CEUS.
Angiosarcoma
Rare vascular tumour arising from endothelial cells.
US shows multiple small nodules are more common than large mass, with satel-
lite nodules. Otherwise nonspecic US ndings with heterogeneous mass containing cystic and solid components.
Hepatic Leiomyosarcoma
Malignant mesenchymal tumour. Poor prognosis and early metastases.
US shows predominantly solid mass with potential secondary haemorrhage, oth-
erwise nonspecic. CDS does not aid diagnosis.
13 Upper Abdominal US inNeonates, Infants andChildren: (Excluding the Kidneys)
295
Metastasis
Various malignancies may cause liver metastases, particularly neuroblastoma (stage
IV or IV), Wilms tumour and lymphoma. Rare metastases from other primaries (e.g.
carcinoid/gonadal tumours).
US and CDS Findings
Either solitary or multiple, large or small nodules. May be hyper-, iso- and
hypoechoic (Fig13.20c, d). Potentially show target-like appearance. Cysts/degenerative changes may be present. CDS of little value, except for demonstrating
patency of adjacent compressed vessels.
CEUS
Aids differentiation from other liver lesions by showing typical UCA enhancement
dynamics—as known from CT and MR.
Proliferative Disorders
Particularly after transplantation—hepatic involvement in posttransplantation
lymphoproliferative disease and lymphoma/leukaemia common.
US Findings
Single or multiple hyperechoic masses with commonly homogenous echotexture,
well-dened margins. In very small and diffuse involvement—widespread nodular
parenchymal heterogenicity. In periportal inltration periportal areas become
hypoechoic—may result in biliary obstruction. Hepatosplenomegaly is often
present, but nonspecic.
Involvement in leukaemia commonly manifests as diffuse inltration = hepato-
splenomegaly, nonspecic changes of echotexture, potentially some inhomogeneity.
Note Look for secondary changes such as enlarged lymph nodes, ascites and
splenomegaly.
Role ofUS
Often detects/conrms presence of tumour, allows rst assessment of position and
relation to surrounding structures, may suggest specic entity, particularly when
using CEUS. On follow-up, helpful for assessing tumour behaviour under
chemotherapy, long-term recurrences and potential complications.
Histologic diagnosis unavoidable, biomarkers helpful and essential.
Additional sectional imaging mandatory for initial assessment, preoperative
planning and (re)staging according to various tumour study/treatment protocols
(SIOP, COG, etc.).
Additional Imaging
• Ce-MDCT, preferably dynamic ce-MRI.
• For some queries scintigraphy and angiography.
• Rarely (M)ERCP or PET—depending on tumour study protocol and underlying entity.
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13.4 Biliary Tract andGall Bladder
13.4.1 General Findings
Normal intrahepatic bile ducts not visible in (early) childhood, only major central
portion (cystic duct, main hepatic duct, choledochal duct)—using high-resolution
transducers preferably in fasted infants.
In biliary tract diseases almost always similar ndings noted, particularly in
chronic conditions.
Possible US signs—vary with underlying condition, usually consistent with
periportal brosis:
• Prominent echogenic linear periportal area.
• Dilatation or cysts of bile ducts.
• Bile duct dilated and visible—then often irregularly shaped or narrow and not
depictable in echogenic periportal structures.
• Wall thickening of large bile ducts (hepatic and common duct) with increased
echogenicity; also gall bladder can vary in size with thickened wall.
• Secondary intrahepatic gallstone/sludge formation.
• Signs of biliary cirrhosis.
13.4.2 Congenital Conditions andNormal Variants ofBiliary Tract
13.4.2.1 Intrahepatic Gall Bladder
Rare normal variant. No sequelae.
13.4.2.2 Hypo-/Aplasia ofGall Bladder/Biliary Atresia/Neonatal
Hepatitis Syndrome
Rarely isolated, usually associated with other conditions (e.g. intra-/extrahepatic
biliary atresia, a-/hypoplasia).
Definition
Biliary atresia caused by foetal damage/insult to developing liver biliary tract.
Typical biliary atresia develops if main bile duct+hilus affected.
Neonatal hepatitis—nonspecic inammation secondary to different causes,
such as infection or metabolic defects.
Prompt differentiation important, as treatment differs and in biliary atresia early
treatment is of utmost prognostic importance—but denitive diagnosis only achievable by cholangiography, even biopsy may be undecisive.
US Findings
• Nonspecic change of liver texture, US morphology depends on severity of manifestation/already manifest biliary cirrhosis.
• Bile ducts usually invisible.
13 Upper Abdominal US inNeonates, Infants andChildren: (Excluding the Kidneys)
297
• Potentially central triangular cord sign (triangular echogenic spot in liver hilus as
brotic remnant of hilar biliary tract—rather specic sign but can also be seen in
relatively normal central bile duct or hypoplastic biliary system, not diagnostic).
• Central cyst—remnant of central bile system, not to be confused with choledochal cyst (bile duct patent!).
• Small or missing gall bladder (“ghost gall bladder”, <1cm length, normal wall
layers absent).
Note Importance of US is to exclude other conditions that may cause similar clini-
cal appearance and cannot replace histology. But even a relatively normal gall bladder does not “rule out” biliary atresia!
Sometimes US used for percutaneous gall bladder puncture for diagnostic percu-
taneous cholangiography.
Subgroups
Intrahepatic biliary hypoplasia (rarely isolated, often combined with syndromatous
extrahepatic pathology) and neonatal hepatitis syndrome have similar appearance,
but usually lack triangular cord sign.
Often no bile ducts visible—not only because of developmental decit, but also
because of decreased bile production and thus collapse of main bile ducts.
DDx
Intrahepatic cholestatic syndromes—e.g. Alagille syndrome, Byler disease (progressive familiar intrahepatic brosis).
Typical for Byler disease—central dot sign in saccular cystic periportal lesions
(periductal cyst noncommunicating with biliary tract, thus to be differentiated from
Caroli disease). See also Table13.5.
Table 13.5 DDx criteria in neonatal jaundice
Disease US criteria
Neonatal
hepatitis
Biliary atresia Small gall bladder, triangular cord sign, central cyst, potentially biliary
Choledochal cyst Circumscribed cystic dilatation of some segment of the enlarged bile ducts
Liver brosis/
ciliopathies
Caroli syndrome Multiple peripheral intrahepatic saccular dilatations of peripheral bile
Bile obstruction/
inspissated bile
Often gall bladder >1.5cm with still persisting size changes in size after
feeding
cirrhosis
Echogenic periportal area with narrow or potentially irregularly shaped bile
ducts+signs of arterial hyperperfusion (DDx cholangitis)
ducts, signs of liver brosis, biliary cirrhosis
Dilated bile ducts and gall bladder, stone formation, either due to
obstruction or functional impairment (e.g. intensive care treatment/
parenteral nutrition, cystic brosis, Hirschsprung disease, posttraumatic
with haemobilia)
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CDS
Enlarged hepatic artery (secondary to cirrhotic transformation), subcapsular arteries
with inverted ow, signs of portal hypertension, potentially with secondary persistent ductus venosus—secondary to increased liver vascular resistance and cirrhotic
changes.
13.4.2.3 Choledochal Cyst
Definition
Congenital malformation of bile ducts, may gradually develop and increase—diagnosis may be delayed.
Several types with different classications—most commonly Todani classica-
tion used:
• Type I=dilatation of common hepatic duct.
• Type II=true diverticulum of common bile duct.
• Type III= choledochocele (cystic dilatation of common duct at intraduodenal
portion, pancreatic duct drains into it).
• Type IV=Type I and multiple cysts (A=intrahepatic and extrahepatic, B=only
extrahepatic).
• Type V = Caroli disease: segmental non-obstructive dilatation of hepatocholedochal duct and multiple purely intrahepatic peripheral cysts arising from
and connected to peripheral bile ducts (Fig.13.21).
Note Choledochal cysts may coexist with biliary atresia or hypoplasia.
US Findings
• Depends on type.
• More or less biliary ductal dilatation.
• Sometimes only fusiform shape of affected portion.
• Wall can be thickened and echogenic.
Fig. 13.21 Choledochal cysts: (a) Fusiform ectasia of hepato-choledochal duct (+ +)—chole-
dochal cyst Type I. (b) Severe dilatation of common choledochal duct—choledochal cyst. (c)
Ruptured choledochal cyst—septation below liver due to bilious peritonitis, cyst still seen covered
by inamed echogenic mesentery. (d) Multiple cyst-like ectatic intrahepatic bile ducts (++) with
small bile lakes in Caroli syndrome (choledochal cyst Type V)