Neuro - rad-call.com

Intracranial Hemorrhage
General Anatomy Relevant to Stroke
- Lobar anatomy
- Vascular anatomy
Stroke
Maxillofacial Trauma
- Overview
- NOE Classification
- Mandibular Anatomy
Odontogenic Infection
Visceral Neck Trauma
Spinal Trauma
Programmable Shunt Settings
Deep Spaces of the Head and Neck
CT Sinus Anatomy
Temporal Bone Anatomy

For carotid ultrasound please refer to the ultrasound section.

INTRACRANIAL HEMORRHAGE

Evolution of Blood Products

GENERAL STROKE ANATOMY

Scrollable Lobar Anatomy

Vascular Anatomy

Dimmick SJ, Faulder KC. Normal variants of the cerebral circulation at multidetector CT angiography. Radiographics. 2009 Jul-Aug;29(4):1027-43. doi: 10.1148/rg.294085730. PMID: 19605654.

Vascular Territories

Scrollable Vascular Territories

STROKE

Stroke Quick Reference

ASPECTS (MCA stroke)

1 point for each area involved

CT Perfusion

Thrombectomy (simplified)

Core infarct < 70mL
Tissue at risk >15mL

Blunt Cerebrovascular Injury

Denver Criteria

When to screen for BCVI:

Biffle/Denver Grade of BCVI

Grade I	luminal irregularity or dissection with <25% luminal narrowing
Grade II	dissection or intramural hematoma with ≥25% luminal narrowing, intramural thrombus, or raised intimal flap
Grade III	pseudoanuerysm
Grade IV	occlusion
Grade V	transection with free extravasation

MAXILLOFACIAL TRAUMA

Overview of Facial Trauma

Source: Hopper RA, Salemy S, Sze RW. Diagnosis of midface fractures with CT: what the surgeon needs to know. Radiographics. 2006 May-Jun;26(3):783-93. doi: 10.1148/rg.263045710. PMID: 16702454.

NOE Types

Type	Description
Type I	Large bone fragment
Type II	Comminution with fracture lines central to tendon
Type III	Central comminution with fracture lines beneath insertion of the tendon

Mandibular Anatomy

ODONTOGENIC INFECTION

VISCERAL NECK TRAUMA

SPINAL TRAUMA

AO Spinal Injury Classification

Three column concept of the spine (Denis)

Simplified. If ≥2 contiguous spinal columns are disrupted the fracture will be considered unstable. For the lumbar spine but can be extrapolated to the other segments

ALL – anterior longitudinal ligament; PLL – posterior longitudinal ligament; LF – ligamentum flavum; IL – interspinous ligament; SL – supraspinous ligament.

Cervical Spine

Basic search pattern for traumatic cervical spine CT

Normal Craniocervical Measurements in Adults

Basion-dens interval	< 9.5mm
Powers ratio	< 0.9mm
Atlanto-dental interval	<3.0mm
Atlanto-occipital interval	<1.4mm

Ligamentous Anatomy of the Cervical Spine

Atlanto-Occipital Dissociation

Basion-Dens interval >9.5mm
- Alar ligament injury, tectorial membrane disruption
Associated injuries
- SAH at foramen magnum
- Avulsion of the basion, tip of the dens, or occipital condyles

Occipital Condyle Fractures

Type	Characteristics
Type 1	Comminuted, impacted
Type 2	Extension of skull fracture
Type 3	Disruption of Alar ligament (unstable)

C1-C2 Injury

Atlantoaxial Rotary Fixation

Type	Characteristics
Type I	Intact transverse and alar ligaments
Type II	Transverse ligament disruption; 2-3mm anterior translation with rotation
Type III	Alar and transverse ligaments disrupted; >5mm anterior translation with rotation
Type IV	Alar and transverse ligaments disrupted; anterior displacement of C1 over C2 with deficient odontoid

Atlas Fractures

Riascos R, Bonfante E, Cotes C, Guirguis M, Hakimelahi R, West C. Imaging of Atlanto-Occipital and Atlantoaxial Traumatic Injuries: What the Radiologist Needs to Know. Radiographics. 2015 Nov-Dec;35(7):2121-34. doi: 10.1148/rg.2015150035. PMID: 26562241.

Look for the bilateral displacement of the lateral masses on coronal views.
Burst and lateral mass fractures can be associated with tears of the transverse ligament, which are unstable.
- Rule of Spence – separation of fracture fragments >5.4mm on CT = transverse ligament disruption and instability
Ruptures of the ligament can compromise the atlantodental relationship, causing dorsal displacement of the dens, and possibly resulting in compression of the thecal sac.
Jefferson Fracture = C1 burst fracture

Odontoid Fractures

Type	Characteristics
Type I	Apical avulsion fracture (stable in isolation)
Type II	Transverse fracture – most common and unstable. If >4mm displacement or comminuted risk nonunion
Type III	Extends into the C2 body; unstable

Hanged Man Fracture

Hyperextension injury with fracture of both pars interarticularis or pedicles of C2
Atypical fracture – propegation into the vertebral body – get CTA

Type	Characteristics	Management
Type I	Bilateral pars fractures without translation or angulation	Stable; rigid collar
Type II	>3mm anterior displacement or significant angulation C2/3 disc disruption and PLL disruption Most common	Unstable, reduction or surgery depending on the degree of displacement
Type IIa	Significant angulation without anterior displacement Fracture line is more horizontal
Type III	Anterior translation and angulation with facet subluxation or dislocation	Unstable, surgery

Subaxial Spine

Injury is most common around C4/C5

Hyperflexion Injury

Progressive ligamentous injury from posterior to anterior
- Interspinous process widening
- Uncovering of facet joints
- Widening of the posterior disc space – unstable
- Focal kyphosis
- Anterior subluxation

Hyperflexion sparain – isolated PLC disruption – stable
Anterior subluxation – disruption of the PLV and posterior annulus – unstable (2 column injury)
Interfacetal dislocation – unstable
- Perched or jumped facets
- Bilateral or unilateral
- All should undergo MRI
Flexion teardrop – most severe hyperflexion injury
- Anterior cord syndrome – qudriplegia with pain and temperature insensitvity, preserved vibratory and position sense

Hyperextension Injuries

Can be easy to miss
Hyperextension dislocation – disruption of all three columns and unstable
- Anterior disc space widening
- Facet widening
- Extension teardrop fracture

Fused Spine Injury

Chalk stick type fractures – hairline fracture through a fused spine, can be easy to miss
- Seen in hyperflexion and hyperextention injury
If seen – image the entire spine as noncontiguous fractures are common

Thoracolumbar Spine

Injury pattern is based on AO Classification which uses the tension band concept

Anterior Tension Band – limits extension
Posterior Tension Band – limited flexion

AO Spine Classification for Thoracolumbar Injuries

Compression Fracture (A1)

Failure of the anterior column
Isolated anterior compression fracture is considered stable

Pincer Fracture (A2)

Complete coronal split fracture with central collapse and herniation of disc material into the fracture
Unstable

Burst Fracture (A3 or A4)

Disruption of the posterior vertebral body cortex differentiates from compression fracture
- If unclear, look for widening of the interpedicular distance on coronal
Evalute for retropulsed fragment that can cause cord compression
Incomplete burst – one endplate involved (A3)
Complete burst – both endplates invovled (A4)

Flexion Distraction Injuries (B1 or B2)

Transosseous Tension Band Disruption (B1) – Chance Fracture – extends through all through osseous spinal columns
- High association with intraabdominal injuries
- Can also have a pure ligamentous injury – look for distraction and widening of the interspinous space

Ligamentous disruption of the posterior tension band with an class A fracture (B2)

Hyperextension Injury (B3)

Anterior disc space widening
Can be seen within rigid spine (see Carrot stick fracture above)
Can be ligamentous or osseoligamentous

Fracture Dislocation (Type C)

Disruption of all three spinal columns with distraction, dislocation, or translation
If you see two vertebral bodies on the same axial image = fracture dislocation

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