1. 1. Dr. Vinayak Kodur 2nd year resident DM Neonatology L.T.M.General Hospital,Sion
2. 2. Introduction Was introduced in late 1970s Has become an essential diagnostic tool in NICU The non-invasive nature of ultrasonography makes it an ideal imaging technique in the neonate. In the neonate and young infant, the fontanels and many sutures of the skull are still open, and these can be used as acoustic windows to look into the brain. Reliable tool for detecting congenital and acquired anomalies of the peri-natal brain and the most frequently occurring patterns of brain injury in both preterm and full-term neonates.
3. 3. When to scan All babies born at less than 32+6 weeks or with birth weight of 1.5kg or below should be scanned. Scans may need to be repeated more frequently, especially if the baby is particularly unwell or if scans are abnormal. Babies of all gestations requiring ventilation should have routine screening scans on a weekly basis until extubation. The scan should also be repeated during the discharge planning process.
4. 4. Scan in Non-Ventilated and Ventilated Babies
5. 5. Advantage of cranial US (CUS) Safe Bedside- compatible Reliable Early imaging Serial imaging: Brain maturation Evolution of lesions Inexpensive Suitable for screening
6. 6. Aims of Neonatal CUS Exclude/demonstrate cerebral pathology Assess timing of injury Assess neurological prognosis Help make decisions on continuation of neonatal intensive care Optimise treatment and support
7. 7. Cranial Ultrasonography: Technical Aspects Transucers : 57.510 MHz Appropriately sized Standard examination: use 7.58 MHz Tiny infant and/or superficial structures: use additional higher frequency (10 MHz) Large infant, thick hair, and/or deep structures: use additional lower frequency (5 MHz)
8. 8. The acoustic windows : Anterior Fontanel The Standard view window Posterior Fontanel Supplementary view window Mastoid Fontanel Supplementary view window Temporal Supplementary view window
9. 9. Images are usually taken through the anterior fontanelle. In the coronal plane, a series of images are taken through the frontal lobes, more posteriorly through the ventricles and thalami, then along the plane of the choroid plexus, then superior to that. The sagittal images are initially taken in the midline, with images then taken on both sides at the level of the lateral ventricles then periventricular areas.
10. 10. Standard Views(Anterior Fontanel) Coronal Views (at least 6 standard planes)
11. 11. The standard coronal planes:
12. 12. Coronal Section
13. 13. First coronal plane (C1) at the level of the frontal lobes
14. 14. Second coronal plane (C2) at the level of the frontal horns of the lateral ventricles
15. 15. Second coronal plane (C2) at the level of the frontal horns of the lateral ventricles The transducer is angled back. The CSF in the lateral ventricles appears as a dark image. The lateral ventricles are larger in preterm infants than in term infants. Asymmetry between the lateral ventricles is common and is not necessarily abnormal. The cavum septum pallucidum sits between the lateral ventricles and is often large in preterm infants. The corpus callosum appears above the cavum.
16. 16. Third coronal plane (C3) at the level of the foramen of Monro and the thirdventricle
17. 17. Third coronal plane (C3) at the level of the foramen of Monro and the thirdventricle With the transducer shifted slightly further back, the third ventricle appears below both lateral ventricles and the septum pallucidum. It is often small and difficult to see, but can vary considerably in size. The foramen of Monro (connecting lateral and 3rd ventricles) may be clearly seen. The brainstem may be seen as a tree-like shape.
18. 18. Fourth coronal plane (C4) at the level of the bodies of the lateral ventricles.
19. 19. Body of lateral ventricle Choroid plexus Thalamus Hippocampal fissure Aqueduct of Sylvius Brain stem Parietal lobe
20. 20. Fifth coronal plane (C5) at the level of the trigone of the lateral ventricles
21. 21. Fifth coronal plane (C5) at the level of the trigone of the lateral ventricles Angling further back cuts through the trigones of the lateral ventricles. The choroid plexus fills the lateral ventricles in this view and is prominent in preterm infants. Choroid plexus haemorrhage may be difficult to differentiate from bulky choroid. The white matter around the lateral ventricles may appear quite echodense (bright) in this plane and is sometimes called a "blush" or "flare".
22. 22. Sixth coronal plane (C6) through the parieto-occipital lobes
23. 23. Sixth coronal plane (C6) through the parieto-occipital lobes Angling the transducer even more results in an image that slices above the lateral ventricles. In this plane, the occipital cortex may be visualised.
24. 24. Coronal View
25. 25. Standard Views(Anterior Fontanel) Sagittal Views (at least 5 standard planes)
26. 26. Parasagittal View
27. 27. Midsagittal plane (S3) through the third and fourth ventricles
28. 28. Midline Sagittal This identifies useful landmarks. The cerebellar vermis shows up as an echogenic image in the posterior fossa. The 4th ventricle sits in front of this. The cisterna magna sits below the cerebellar vermis and is not very echogenic. The corpus callosum is seen sweeping from anterior to posterior with the cingulate gyrus above and parallel to it. The parieto-occipital sulcus is seen well above the posterior fossa.
29. 29. Forth Ventricle Vermis of Cerebellum
30. 30. Second and fourth parasagittal planes (S2, S4) through the right and left lateral ventricles
31. 31. Angled Parasagittal View: The shape of the lateral ventricle is the key landmark for this view. The caudate nucleus lies below the floor of the frontal horn of the lateral ventricle; the thalamus lies behind and below it. The occipital horn of the lateral ventricle is filled with choroid plexus. The choroid tucks up in the caudothalamic groove in the floor of the lateral ventricle and may be echogenic.
32. 32. Para-saggital View
33. 33. First and fifth parasagittal planes (S1, S5) through the insulae (right and left)
34. 34. Tangential Parasagittal View: Further angulation of the transducer laterally results in a section lateral to the lateral ventricles. The Sylvian fissure is the key landmark in this view.
35. 35. Saggital View
36. 36. Preterm Vs Term Brain
37. 37. Coronal View
38. 38. Saggital View
39. 39. ABNORMALITIES: PVL IVH Hydrocephalus
40. 40. Peri Ventricular Leukomalacia (PVL) PVL is also known as HIE of the preterm. A white matter disease that affects the periventricular zones. In prematures this white matter zone is a watershed zone between deep and superficial vessels. PVL presents as areas of increased periventricular echogenicity PVL occurs most commonly in premature infants born at less than 33 weeks gestation (38% PVL) and less than 1500 g birth weight (45% PVL).
41. 41. PVL Detection of PVL is important because a significant percentage of surviving premature infants with PVL develop cerebral palsy, intellectual impairment or visual disturbances.
42. 42. Pathogenesis The pathogenesis of PVL has been found to relate to three major factors: (1)the immature vasculature in the periventricular watershed; (2)the absence of vascular autoregulation in premature infants, particularly in the cerebral white matter; and (3)the maturation-dependent vulnerability of the oligodendroglial precursor cell damaged in PVL. These cells are extremely vulnerable to attack by free radicals generated in the ischemia-reperfusion sequence.
43. 43. DeVries classification of PVL grading on ultrasound Grade I PVL: Prolonged periventricular flare present for 7 days or more. Grade II PVL: Presence of small-localized fronto-parietal cysts. Grade III PVL: Extensive periventricular cystic lesion involving occipital and fronto-parietal white matter. Grade IV PVL: Areas of extensive sub cortical cystic lesions.
44. 44. Flaring
45. 45. Flaring The term flaring is used to describe the slightly echogenic periventricular zones, that are seen in many premature infants in the first week of life. During this first week it is not sure if this is a normal variant or a sign of PVL grade 1. Flaring persisting beyond the first week of life is by definition PVL grade 1. Follow up is needed to differentiate flaring from PVL grade I.
46. 46. Parasagittal image of a child with PVL grade 1
47. 47. Grade 1 PVL PVL is diagnosed as grade 1 if there are areas of increased periventricular echogenicity without any cyst formation persisting for more than 7 days. Increased periventricular echogenicity is however a nonspecific finding that must be differentiated from the normal periventricular halo or normal hyperechoic 'blush' posterosuperior to the ventricular trigones. Suspect PVL if the echogenicity is asymmetric, coarse, globular or more hyperechoic than the choroid plexus. The abnormal periventricular echotexture of PVL usually disappears at 2-3 weeks.
48. 48. Coronal and sagittal image of a child with PVL grade 2.
49. 49. Grade 2 PVL The echogenicity resolves at the time of cyst formation. 2% of the preterm neonates born before 32 weeks develop cystic PVL. If cystic PVL is identified on cranial ultrasounds on the first day of life, indicating that the adverse event was at least 2 weeks prenatal rather than perinatal or postnatal.
50. 50. Saggital image demonstarting extensive PVL grade 3 Swiss-cheese like appearance
51. 51. Grade 3 PVL PVL is diagnosed as grade 3 if there are areas of increased periventricular echogenicity, that develop into extensive periventricular cysts in the occipital and fronto-parietal region. For occipital lobe involvement sometimes need a posterior fossa view.
52. 52. Coronal and transverse images demonstrating PVL grade 4
53. 53. Grade 4 PVL PVL is diagnosed as grade 4 if there are areas of increased periventricular echogenicity in the deep white matter developing into extensive subcortical cysts. PVL grade 4 is seen mostly in fullterm neonates as opposed to PVL grade 1-3, which is a disease of the preterm neonate.
54. 54. Frontal and parieto-occipital Flare: Grade I PVL (sagittal view)
55. 55. B/L extensive parieto-occipital cystic PVL: Grade III PVL (sagittal view).
56. 56. PVL
57. 57. IVH
58. 58. IVH/GMH GRADING VOLPE By CUS (Cranial US)
59. 59. IVH/GMH GRADING PAPILE By CT SCAN GRADE 1 - Isolated GMH (no IVH) GRADE 2 - IVH without ventricular dilatation GRADE 3 - IVH with ventricular dilatation GRADE 4 - IVH with parenchymal hemorrhage
60. 60. Germinal matrix hemorrhage (a/k/a periventricular hemorrhage or preterm caudothalamic hemorrhage) These germinal matrix hemorrhages occur in the highly vascular but also stress sensitive germinal matrix, which is located in the caudothalamic groove. This is the subependymal region between the caudate nucleus and thalamus. The germinal matrix is matured by 34 weeks gestation, such that hemorrhage becomes very unlikely after this age.
61. 61. GMH... Most GMHs occur in the first week of life These hemorrhages start in the caudothalamic groove and may extend into the lateral ventricle and periventricular brain parenchyma. Grade 1 and 2 bleeds generally have a good prognosis. Grade 3 and 4 bleeds have variable long-term deficits
62. 62. Grade 1 IVH
63. 63. Grade 2 IVH
64. 64. Note the echogenic blood (arrowheads) filling 10 mm across the atria of the posterior or anterior horn of lateral ventricles at any point in the gestation alternatively, a separation of more than 3 mm of the choroid plexus from the medial wall of the lateral ventricle may be used
65. 73. Fetal Hydrocephalus Asymmetric hydrocephalus when >2mm discepancy between two sides. When ventriculomegaly is pronounced, the choroid plexus will no longer lie in an almost parallel fashion against the lateral ventricular wall. Tethered at the foramen of Monro the free hanging choroid will "hang down" and appear to "dangle" within the dilated ventricle. This appearance is often termed the dangling choroid sign.
66. 74. Severity The severity of ventriculomegaly can be further classified as mild fetal ventriculomegaly: lateral ventricular diameter between 10-12 mm moderate fetal ventriculomegaly: 12.1-15 mm severe fetal ventriculomegaly (also sometimes classified as fetal hydrocephalus): lateral ventricular diameter >15 mm
67. 75. Levene index
68. 76. Levene index Up to 40 weeks of gestational age the Levene-index should be used and after 40 weeks the ventricular index. The Levene index is the absolute distance between the falx and the lateral wall of the anterior horn in the coronal plane at the level of the third ventricle. These measurements can be compared to the reference curve and if it is >4mm than the 97th percentile then said to be hydrocephalus.
69. 77. Ventricular index
70. 78. Ventricular index After 40 weeks the ventricular index or frontal horn ratio should be used, i.e. the ratio of the distance between the lateral sides of the ventricles and the biparietal diameter.
71. 79. Doppler Doppler Vascular Measurements: The vessels that are the easiest to access are the anterior cerebral artery (ACA), best seen through the anterior fontanelle in the sagittal plane and the middle cerebral artery (MCA) best seen through the temporal window in the axial plane. The Resistivity index (RI) : PS ED SV - DV PS SV Where PS= peak systolic velocity and ED = end diastolic velocity. The normal range is about 0.65 - 0.90. Values below 0.5 or above 0.9 are abnormal.
72. 80. Choroid Plexus Cyst In postnatal US these cysts of the chorioid plexus are often incidental findings without clinical consequences. Chorioid plexus cysts (CPC) are however of importance for obstetricians. At prenatal US these cysts can be predictive of trisomy 18. About half of babies with Trisomy 18 show a CPC on ultrasound, but nearly all of these babies will also have other abnormalities on the ultrasound, especially in the heart, hand, and feet. An exeption must be made for cysts that arise close to the foramen of Monro.
73. 81. CPC Although these cysts often disappear spontaneously, follow up US is necessary to ensure disappearance. Some may produce symptoms of raised intracranial pressure due to obstruction to the cerebrospinal fluid (CSF) flow.
74. 82. CPC
75. 83. Grade 4 IVH with Porencephalic Cyst
76. 84. Supplemental Acoustic Windows
77. 85. Coronal view, using the posterior fontanel as an acoustic window 8. Temporal Lobe 22. Cerebellum 23. Tentorium 25. Occipital lobe 27. Calcarine fissure 29. Medulla Oblongata 36. Occipital horn of lateral ventricle 38. Falx 39. Straight sinus (sinus rectus)
78. 86. Parasagittal view, using the posterior fontanel as an acoustic window 8. Temporal Lobe 15. Choroid plexus 16. Thalamus 20. Parietal Lobe 21. Trigone of Lat. Ventri 22. Cerebellum 25. Occipital lobe 27. Calcarine fissure
79. 87. Upper Transverse view using the left temporal window
80. 88. Lower transverse view using the left temporal window
81. 89. Coronal view using the mastoid fontanel as an acoustic window
82. 90. Transverse view using the mastoid fontanel as an acoustic window
83. 91. Legends of Corresponding Numbers in Ultrasound Scans 23. Tentorium 24. Mesencephalon 25. Occipital lobe 26. Parieto-occipital fissure 27. Calcarine fissure 28. Pons 29. Medulla oblongata 30. Fourth ventricle 31. Cisterna magna 32. Cisterna quadrigemina 33. Interpeduncular fossa 34. Fornix 35. Internal capsule 36. Occipital horn of lateral ventricle 37. Insula 38. Falx 39. Straight sinus (sinus rectus) 40. Temporal horn of lateral ventricle 41. Circle of Willis 42. Prepontine cistern 1. Interhemispheric fissure 2. Frontal lobe 3. Skull 4. Orbit 5. Frontal horn of lateral ventricle 6. Caudate nucleus 7. Basal ganglia 8. Temporal lobe 9. Sylvian fissure 10. Corpus callosum 11. Cavum septum pellucidum 12. Third ventricle 13. Cingulate sulcus 14. Body of lateral ventricle 15. Choroid plexus (*: plexus in third ventricle) 16. Thalamus 17. Hippocampal fissure 18. Aqueduct of Sylvius 19. Brain stem 20. Parietal lobe 21. Trigone of lateral ventricle 22. Cerebellum (a: hemispheres; b: vermis)
84. 92. Thank You