Imaging Examination

NEURORADIOLOGY Dr. Ramirez

Imaging Examination:

Head: 1. Plain Radiographs a. PA view b. Lateral view c. Towne’s view d. Caldwell’s view e. Water’s view

2. Contrast Examination a. Arteriography b. Pneumoencephalography- introducing an air

3. Ultrasound – fontanel, suture are fused; absence of window 4. CT Scan 5. MRI 6. Radioisotope studies

PA- frontal bones, frontal and ethmoid sinuses, nasal cavity cavity, superior orbital rims and mandible.

Lateral- frontal bone and paranasal sinuses

Towne’s- occipital bone, mastoid and inner ear region, foramen magnum and zygomatic arches

Submentovertical – basal structure of the skull including the major foramen.

PA View:  Patient is in normal supine position  Note outer and inner table (smooth)  Vertex, temporal and partial area are of thinning density

Densities:  Black- air (usually dark or loosen)  White- bones, calcification  Gray- soft tissue density

Lateral View:  Ethmoid sinus beneath frontal or greater wing of sphenoid  Frontal sinus  Sphenoid sinus- beneath sella  Maxillary sinus Lobes (fossa)

Frontal lobe- anterior Parietal lobe- middle Cerebrum and pons- posterior Petrous bone- ridge and anterior margin of posterior fossa

Lesser wing of sphenoid- anterior margin of the anterior fossa

Towne’s View:  Foramen magnum  Lambdoid (triangular)

Submentovertical View:  Foramen magnum- lacerated  Foramen ovale- round

Caldwells View:  PA with little angulation  Margin of orbit  Temporal bone

AP View:  Middle cerebral artery

Circle of Willis:

Anteriogram study: Three phases of arteiography: 1. arterial 2. parenchymal 3. venous

Artery on left side Anterior cerebral artery- midline; space occupying lesion Displaced to the right- Focal hydrocephalus Communicating- no obstruction; increase production of CSF

SKULL ABNORMALITIES: 1. Size a. small (microcephaly)  incomplete development  craniostenosis  pituitary abnormality b. large (macrocephaly)  hydrocephalus  endocrine disorders (acromegaly)  congenital or development (osteogenesis imperfecta)  2/4 skull- 1/3 face 2. Contour  Craniostenosis  Meningoencephalocoele  Depressed fracture Osteomas- benign, inc. density of bone Platysbia- osteogenesis imperfecta (paget’s disease, Arnold Chiari malformation)

3. Lucencies  Fracture  Infection (asteomyelitis)  Neoplastic  Metabolic/endocrine (hyperparathyroidism) Fracture- dense Margin is stenotic ordenser

4. Opacities or Densities  Calcification- physiologic  Congenital/development (osteoporosis, engelan’s dx)  Teratoma- calcification, fat, air in soft tissue

HYDROCEPHALUS  Posterior and anterior fontanel  Wormians- vascular branching

Radiographic evidence of intracranial space occupying lesions: 1. increase convolutional impression 2. separation of sutures (up to about 14 to 15 years) 3. sella turcica changes 4. erosions of the bones of the skull 5. displacement of the physiologically calcified suture  abnormal vascular grooves  abnormal calcification within the lesion

Structures that are already calcified: 1. pineal gland- midline 2. choroids plexus- lateral 3. cerebral falx- midline 4. havinular commisure- midline 5. glenoid ligaments- area of sella

1-6 months old  lukenchalden/lacunar skull  hydrocephalus caputsuccedaneum- cross behind suture lines cephalhematoma- above calvareum; soft tissue lytic- lucent lesion blastic- sclerotic lesion multiple densities: -infant- osteocytosis encephalocoele- brain and CSF meningocoele- only brain parenchyma havinular calcification- C calcification pineal gland- round or ovoid calcification Choroid plexus Calcification- “popcorn-like calcification” Toxoplasmosis lesion in the parenchyma- parasitic

Frontal View of Sella:  external auditory canal  sphenoid  dorsal sella  14 by 17- posterior sphenoid  1:17 cm

Radiographic evidence of sellar/ parasellar lesion:

Intrasellar lesion:  thinning and deepening of sellar fossa  thinning of backward bending of the dorsum sellae  destruction of the bony walls of the sella (late stage)

Extracellular Lesion:  sellar floor is thinned but not depressed  dorsum sellae thinned out

CT Scan:

Dark: White: 1. fat- dark in CT scan 1. bone 2. fluid 2. calcification 3. air-dark 3. contrast 4.acute bleed

Magnetic Resonance Imaging (MRI) Hydrogen Ion- align in the magnetic range

Two studies of CT Scan:

T1- on magnet- hydrogen ion synchronized

T2- off the magnet- measure how hydrogen ion is disoriented Edema- lot of hydrogen ion Trauma- plain study Inflammatory- contrast study TB meningitis- increase creatitine

Trauma patient: Subdural hemorrhage- less dense than skull but denser than parenchyma Epidural bleed- bulge toward parenchyma, do not follow the contour of brain Subdural- follow the contour of the brain Infarct- involving the basal ganglia Internal capsule- divides external ganglia from thalamus Abscess- ring enhancing lesion Parenchyma and midline- middle blastoma

Spines: 1. AP 2. oblique 3. CT scan 4. MRI 5. arteriogram 6. Isotope studies

Intramedullary- spinal cord involved Extramedullary and extradural- one side of the spinal cord

Contours:

Kyphosis- thoracic Lordosis- lumbar Spondylostasis- anterior displacement Spondylosis- protruding in laminal parenchyma Hemivertebra- one bone is undeveloped Fused vertebra- intervertebral space absent

Scatty dog appearance: Neck transverse process Ear is pedicle and facet Body is post vertebra Legs inferior articulating artery