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Brain Ultrasound in neonates and infants:
still an important first line imaging
Riccabona MichaelUniversity Hospital Graz, Austria
LKH - Universitätsklinikum LKH - Universitätsklinikum
Lviv
2011
Established applications, value of Doppler-US + new aspects
• Basic neurosonography– well established
• New applications & modern techniques − broadened US potential
• Doppler & (amplitude coded) color Doppler US• high resolution US (HR)• harmonic imaging (HI)
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New aspects & new US methods• increasingly integrated into standard imaging
− transcranial approach (TCI)− spinal canal
+ extended view − US of the infants orbit & skull− contrast-enhanced US− 3DUS
Established applications, value of Doppler-US + new aspects
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IntroductionPediatric neurosonography predominately relies on
• transfontanellar US– for viewing the neonatal brain, including DS= modality of choice for bedside assessment
Many clinically important indications established
• small part US of the spinal canal– for evaluating the neonatal spinal canal
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Basic US requisites
• Sector array: transfontanellar & transtemporal
• Linear array: brain surface, skull, orbit, spine …
• Knowledge & experience & prudent skill– mind: low output (Watt) = low MI/TI– aim at short investigation time in preterm babies!
• Frequency: 15 / 10 - 2 MHz– for (N)ICU: (a)CDS / PW-DDS capabilities
+ transfontanellar & axial / transtemporal views
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Normal brain US images
• (para-) sagittalStandardized & comprehensive assessment
• coronal
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Normal brain US imagesStandardized & comprehensive documentation
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Additinal sections• Brain surface => HR-US, linear transducer
– compulsory in special conditions
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Additinal sections
• infarction• „battered child“• thrombosis• gyration disorders
• Brain surface => HR-US, linear transducer– compulsory in special conditions
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Additinal sections
• infarction• „battered child“• thrombosis• gyration disorders
• Axial acquisition => sector Tdx– helpful, lower frequencye.g., extra-axial collections
brain stem & posterior fossa, …
• Brain surface => HR-US, linear transducer– compulsory in special conditions
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How to measure• Standardized sections
– all pathology• in 2 planes
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How to measure• Standardized sections
– all pathology• in 2 planes
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How to measure• Standardized sections
– all pathology• in 2 planes
- essentialfollow-up
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How to measure• Standardized sections
– all pathology• in 2 planes
- essentialfor follow upmedico-legal aspects, …
- use „landmarks“as a reference
e.g. midline structures, …
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Typical US findings
• PVE / PVLin preterm babies – apnoea, hypoxia, low RR, …
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Typical US findings
• US findings:– periventricular echogenicity– particularly suspicious if
– patchy, – inhomogeneous, – asymmetrical …
• PVE / PVLin preterm babies – apnoea, hypoxia, low RR, …
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Typical US findings
• Initially often difficult to differentate– may be normal in immaturity
clue to diagnosis => follow-up (cysts, …)
• US findings:– periventricular echogenicity– patchy, inhomogeneous, …
• PVE / PVLin preterm babies – apnoea, hypoxia, low RR, …
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Most frequent query: IVH• Typical in preterm babies
– vary with gestational age
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Most frequent query: IVH
DD: plexus bleedcongested plexus
• Typical in preterm babies– vary with gestational age
• SEB = IVH I°
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Most frequent query: IVH
• IVH II° + III°
DD: plexus bleedcongested plexus
IVH III + PVH
• Typical in preterm babies– vary with gestational age
• SEB = IVH I°
• III + secondary PVH= IVH IV° in old terminology
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Most frequent query: IVH
• IVH II° + III°
• IVH III + secondary PVHhydrocephalus & cysts
DD: plexus bleedcongested plexus
• Typical in preterm babies– vary with gestational age
• SEB = IVH I°
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Most frequent query: IVH
DD: hemorrhagic infraction for other reasons
DD: plexus bleedcongested plexus
• Typical in preterm babies– vary with gestational age
• SEB = IVH I°
• IVH II° + III°
• IVH III + secondary PVH
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Other cranial hemorrhages
• In a term neonate– brain stem bleed
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Other cranial hemorrhages
• After traumae.g., cesarean section– tentorial hemorrhage
• In a term neonate– brain stem bleed
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Other cranial hemorrhages
• After traumae.g., cesarean section– tentorial hemorrhage
• Secondary hemorrhage– hemorrhagic infarction– (vascular) malformation– tumor (lipoma), sinus thrombus ...
• In a term neonate– brain stem bleed
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Hydrocephalus & atrophy• Posthemorrhagic findings: cysts• Hydrocephalus
– echogenic wall after bleed
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Hydrocephalus & atrophy
– congenital brain malformation?• axial approach• occipital scan• AVM? - CDS
• Posthemorrhagic findings: cysts• Hydrocephalus
– echogenic wall after bleed
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Hydrocephalus & atrophy
– congenital brain malformation?• axial & occipital approach, AVM?
– brain pressure & drainage need?• eye-US & DDS
• Posthemorrhagic findings: cysts• Hydrocephalus
– echogenic wall after bleed
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Hydrocephalus & atrophy
– congenital brain malformation?• axial & accipital approach, AVM?
– brain pressure & drainage need?• eye-US & DDS
– DD: atrophy, subdural collection
• Posthemorrhagic findings: cysts• Hydrocephalus
– echogenic wall after bleed
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Hydrocephalus & atrophy
= follow- up essential– for clinical course & DD (other cysts …)
– congenital brain malformation?• axial & occipital approach, AVM?
– brain pressure & drainage need?• eye-US & DDS
– DD: atrophy, subdural collection
• Posthemorrhagic findings: cysts• Hydrocephalus
– echogenic wall after bleed
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US criteria in brain malformations
• Usually diagnosed prenatally– postnatal confirmation + follow-up + exact diagnosis
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US criteria in brain malformations
• US-aspects:– corpus callosum
+ septum pellucidum?
– CSF spaces– posterior fossa!
• Usually diagnosed prenatally– postnatal confirmation + follow-up + exact diagnosis
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US criteria in brain malformations
• US-aspects:– corpus callosum
+ septum pellucidum?
– CSF spaces– posterior fossa!– brain parenchyma => HR-US
• gyration? heterotopia? …
• Usually diagnosed prenatally– postnatal confirmation + follow-up + exact diagnosis
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Other & unusual views / access• Occipital & nuchal
– posterior horn & posterior fossa
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Other & unusual views / access
• Transtemporal + axial– great vessels + DDS / CDS
• comparison, …– brain stemm– extra-axial
collections
• Occipital & nuchal– posterior horn & posterior fossa
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Other & unusual views / access
• Transtemporal + axial– great vessels + DDS / CDS
• comparison, …– brain stemm– extra-axial collections
• Occipital & nuchal– posterior horn & posterior fossa
• Older children– fontanella closed => allways TCI
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Transfontanellar US• improved border definition
Modern US - HI in the brainLviv 2011
Transfontanellar US• improved border definition• depiction of focal lesions
– tumors, edema, abscess, …– hemorrhage, ...
Modern US - HI in the brainLviv 2011
Transfontanellar US• improved border definition• depiction of focal lesions
– tumors, edema, – hemorrhage, abscess, ...
Modern US - HI in the brain
• delineation of liquid structures– hydrocephalus, cysts, …– shunt, …
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What about Doppler sonography= established + helpful tool
• Fontanellar approach- always use also duplex Doppler- perform spectral analysis
- allows for functional evaluation- not achievable by an other method
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What about Doppler sonography= established + helpful tool
+ transtemporal CDS• Fontanellar approach
- allows for functional evaluation- not achievable by an other method
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What about Doppler sonography
• Many indications– vessel anatomy– brain perfusion– DD liquid - vascular
= established + helpful tool
+ transtemporal• Fontanellar approach
- allows for functional evaluation- not achievable by an other method
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e.g., AsphyxiaTypical development:
– initially normal
=> RI normal or– then hyperemia
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e.g., AsphyxiaTypical development:
– initially normal
– increase in resistance=> Vdiast reduced => RI = • then Vsyst
• tent shaped diastoly
– then hyperemia=> RI normal or
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e.g., AsphyxiaTypical development:
– initially normal
– undulating blood => no sufficient perfusion, brain death
– then hyperemia
• diastolic flow reversal
– increase in resistance=> Vdiast reduced => RI = • then Vsyst
• tent shaped diastoly
=> RI normal or
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Older children => query brain death?• After every cerbral hypoxia, using TCI
– drowning, ...– bed side evaluation
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DS in brain pressure• Flow pattern change with intracranial pressure
– basic-DDS => normal? – extracranial flow pattern?
• V syst, V diast, RI …
– standardized ACI-DDS• flow velocities increase with pressure• difference extra- & intracranial portion
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DS in brain pressure• Flow pattern change with intracranial pressure
– basic-DDS => normal? – extracranial flow pattern?
• V syst, V diast, RI
– standardized ACI-DDS• flow velocities increase with pressure• difference extra- & intracranial• for velocity measurements:
ALWAYS apply angel correction
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DS in brain pressure
– changes with fontanellar compressionV syst , RI
• Flow pattern change with intracranial pressure– basic-DDS => normal? – extracranial flow pattern?
• V syst, V diast, RI
– standardized ACI-DDS • flow velocities increase with pressure• difference extra- & intracranial portion• angle correction
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Functional DDS• Note: flow pattern change with circulation
– with head position• SIDS • DD subclavian steel phenomenon
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Functional DDS
– pCO2• respirator settings …
• Note: flow pattern change with circulation– with head position
• SIDS, DD subclavian steel
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Functional DDS
– pCO2• respirator settings
– tachycardia• bradycardia …
• Note: flow pattern change with circulation– with head position
• SIDS, DD subclavian steel
– medication• cathecholamine, RR- drugs & inotrop medication., ...
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Specific applications
• Peripheral vasculature– arteries & veins
• aCDS: less angle dependency
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Specific applications
• Liquor flow– if CSF particles present
• Peripheral vasculature– arteries & veins
• aCDS: less angle dependency
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Specific applications
• DD of structures– tumor– SDH versus atrophy
• Liquor flow– if CSF particles present
• Peripheral vasculature– arteries & veins
• aCDS: less angle dependency
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Other findingsBrain US may give the clue to diagnosis• Look for these findings• Use all options
– infection & abscess– syndromatic disease
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Other findingsBrain US may give the clue to diagnosis• Look for these findings• Use all options
– infection, abscess, syndromes– necrosis, …
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Don‘t forget• Documentation
– measurements: Vsyst, Vend.diast, RI, TAV – angle correction (> 20°)– peripheral + central vessels
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Don‘t forget
– including axial assessment– aCDS may be helpful (TCI)
• Arteries ACA, ACI, ACM, ACP, AB
• Documentation– measurements: Vsyst, Vend.diast, RI, TAV – angle correction (> 20°)– peripheral + central vessels
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Don‘t forget
• And veins!!– V. Galeni, sup. sag. sinus, deep sinus, …
– including axial assessment– aCDS may be helpful (TCI)
• Arteries ACA, ACI, ACM, ACP, AB
• Documentation– measurements: Vsyst, Vend.diast, RI, TAV – angle correction (> 20°)– peripheral + central vessels
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Echo-enhanced US of the brain• Rare indications in neonates
– DD: Tu versus blood clot (i.v. ce-US)=> increased conspicuity
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Echo-enhanced US of the brain• Rare indications in neonates
– DD: Tu versus blood clot (i.v. ce-US)=> increased conspicuity
– intraluminal application• complicated hydrocephalus
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Brain ee-US in older children
• Improve visualization=> see vessels
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Brain ee-US in older children
• Improve visualization=> see vessels= capability to analyze
angle correction …
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Brain ee-US in older children
• Improve visualization=> see vessels= capability to analyze
• Indications– brain perfusion
• after hypoxia• in tumors
– vascular malformation• follow-up
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Finally: spinal US• Established in the neonatal & infant spine• Prerequisites:
– high resolution linear Tx
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Finally: spinal US• Established in the neonatal & infant spine• Prerequisites:
– high resolution linear Tx– experience
– knowledge, training– helpful accessories:
• image compounding • split (double) image, m-mode
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Finally: spinal US• Established in the neonatal & infant spine• Prerequisites:
– high resolution linear Tx
• extended field of view = panorama US
– experience– knowledge, training
– helpful accessories: • image compounding • split (double) image, m-mode
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US technique
• neck slightly bent (occipital view)
• Dorsal approach– prone or decubitus position– blanket? pillow?
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US technique
• neck slightly bent (occipital view)
• Dorsal approach– prone or decubitus position– blanket? pillow?
– continue upwards• Start sacral
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US technique
• Start sacral– continue upwards
• neck slightly bent (occipital view)
• Dorsal approach– prone or decubitus position– blanket? pillow?
• Use unusual approch– ventral / transabdominal– fill bladder / colon
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Extended US examination• Use modern techniques
– m-mode, extended field of view, 3DUS
• Know anatomy– normal variants
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Extended US examination• Know anatomy & use modern techniques
– normal variant? m-mode, extended view, 3DUS
• Visualization of cranio-cervical junction– herniation of tonsils?– curved / sector array
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Extended US examination• Know anatomy & use modern techniques
– normal variant? m-mode, extended view, 3DUS
• Visualization of cranio-cervical junction– herniation of tonsils?– curved / sector array
• If spinal pathology present + brain US– associated malformation? Hydro?– transfontanellar, transtemporal, …
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Normal US findingsLviv 2011
Other important US indications
– linear array, hematoma?• Skull fracture
– look for tear drop leasions!
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Other important US indications
• Extra-axial hemorrhage? – you may try US (axial!)
If unclear, SAH (tentorial) …=> CT!
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Other important US indications
• Extra-axial hemorrhage? – you may try US (axial!!)– tentorial, unclear, SAH => CT?
– linear array, hematoma?– look for tear drop leasions!
• Skull fracture
• DD of uncertain (spine & brain) lesions– aCDS, axial view, move, ce-US, …
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Other important US indications
• Extra-axial hemorrhage? – you may try US (axial!!)– tentorial, unclear, SAH => CT?
– linear array, hematoma?– look for tear drop leasions!
• Skull fracture
=> MRI …• DD of uncertain (spine & brain) lesions
– aCDS, axial view, move, ce-US, …
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• Indications for skull film:– fracture & trauma – premature synostosis– skull defects …
When to use which modality?Lviv 2011
• Indications for skull film: – Fracture, trauma, premature synostosis, defects, …
When to use which modality?
• CT: – unclear US findings– acute severe (multiple) trauma – calcifications – bone pathology – CT-angiography– if no MRI available
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• Indications for skull film: – fracture & trauma, premature synostosis, defects, …
When to use which modality?
• MRI:– malformations (heterotopia, gyration …) – metabolic disorders, …
• CT: – acute trauma, calcifications, ..– bone pathology, CT-angiography– if no MRI available
– asphyxia, trauma (late phase) / battered child, tumor …
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Imaging algorithms
• Impact on therapy or prognosis = „evidence based“
• Patient oriented– adapted to local circumstances
• As little invasive / ionising as possible– ALARA - principle
• No examnination without valid indicatione.g., if US cannot answer query => CT / MR, NO US
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e.g., birth trauma• What do we expect, what can we treat?
– asphyxia– hemorrhage
• tentorial, dural
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e.g., birth trauma• What do we expect, what can we treat?
– asphyxia– hemorrhage– fractures / epiphysiolysis
• plain film • chest, clavicle, …
• US => epiphysis
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e.g., birth trauma• What do we expect, what can we treat?
– asphyxia– hemorrhage
=> MRT! (delayed)
– spinal traumaUS = initial imaging • bed side
– fractures / epiphysiolysis• plain film (chest, clavicle, …)• US => epiphysis
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Take away
• holds great diagnostic potential– though not yet all approaches & methods established
Modern US of the neonatal brain and spine
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Take away
Modern US = valuable adjunct to conventional 2DUS
• holds great diagnostic potential– though not yet all approaches established
• improves already established value– & documentation
• provides valuable information
Modern US of the neonatal brain and spine
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• Questions?• Comments?
Better ask me - otherwise I shall ask you …!
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