13 yo male with ATV accident (no helmet). Initially asymptomatic and shortly later had altered mental status and respiratory failure (intubated).

Bone window CT; Noncontrast head CT; Noncontrast MR T1-w sequence; MR flair or T2w spin echo; MR susceptibility (SWI); MR diffusion (DWI & ADC maps)

Bone window CT head and upper C-spine
1. Extensive fracture of the left facial bones, left orbital apex, left otomastoid, left greater & lesser sphenoid wings. There are inner bone table fractures of both frontal bones, both ethmoid bones and the roof of the left otomastoid bones. 

Noncontrast head CT
1. Extensive fractures mainly involving the left face (i.e. LeFort-3 complex). There are bilateral frontal bone fractures and ethmoid fractures with inner table fracture, likely the source of the intracranial air. There is a transverse fracture of the left temporal bone. There are fractures involving the left orbital apex including a posterior ethmoid bone spicule in close proximity to the optic nerve.
2. There are left intraorbital injuries with retroconal hemorrhages, probable Tenon's space hematoma, and ocular proptosis without obvious tenting.
3. There is a  4-5 mm subdural hematoma within the left anterior temporal fossa extending laterally along the basilar and low convexity of the temporal lobe. The does not produce uncal herniation.

Noncontrast MR T1-w post contrast
1. The T1-w MR adds no additional information not supplied by the head CT.

MR flair & MR  T2-w
1. There are multiple sites of brain contusion not evident on prior sequences, see above
2. There is focal edema in the left mesial globus pallidus, consistent with a vascular perforator shear injury.
3. There is optic hydrops consistent with raised intracranial pressure

MR susceptibility (SWI)
1. MR susceptibility confirms the presence of hemorrhage within the multiple sites of brain parenchyma on prior sequences, see above
2. MR susceptibility confirms the presence of micorhemorrhage within the left mesial globus pallidus in the site of apparent perforator shear injury.
3. MR susceptibility confirms the presence of linear micorhemorrhage within the left cerebellum consistent with a site of venous avulsion shear injury and parenchymal laceration. 

MR diffusion dwi/adc maps "f"
1. Abnormal MR diffusion for cytogenic brain injury in the left basifrontal parenchyma and in the left mesial globus pallidus.

1. There is a left LeFort-3 fracture complex extending into the left orbital apex. There is a transverse left otomastoid fracture complex, a left greater & a lesser sphenoid wing fracture. There are inner bone table fractures of both frontal bones, both ethmoid bones and the roof of the left otomastoid bones. There is intracranial free air in the left frontal area.

2. There is a displaced caudal mesial orbital fracture producing retroglobal hemorrhage with ocular proptosis, but no tenting; the ethmoid fracture likely misses the left optic nerve. There is a small right Tenon's space hematoma.

3. There is retroglobal hemorrhage with ocular proptosis, but no tenting. There is a small right Tenon's suture hematoma.

4. There is a  4-5 mm subdural hematoma within the left anterior temporal fossa extending laterally along the basilar and low convexity of the temporal lobe. The hematoma does overlap the left sphenoparietal sinus possibly causing venous egress block; it does not produce uncal herniation.

5. The follow-up MR flair demonstrates a much wider area of brain contusion than was evident on CT. Edema is now evident along the left basifrontal cortex, the left anterior temporal pole and left basal ganglia. SWI demonstrated punctate microhemorrhage in the same areas of tissue contusion. It demonstrates a linear site of hemorrhage in the left cerebellum consistent with a venous tether avulsion injury. The MR diffusion is positive in the left frontopolar parenchyma consistent with post traumatic tissue necrosis.  

1. LeFort types 2 & 3 fractures and temporal bone fractures have significant intracranial implications, because fractures of their inner table add an infections risk.

2. LeFort types 2 & 3 fractures have significant intracranial implications, because fractures of the inner table can produce epidural hemorrhages by transecting the anterior meningeal artery origin which arises off the posterior ethmoid artery, which arises off the ophthalmic artery.

3. LeFort types 2 & 3 fractures can involve the optic strut portion of the optic canal potentially causing optic nerve compression at the time of injury or later when the facial deformity is repaired; therefore it must be detected initially.

4. LeFort types 1- 3 fractures can involve the mesial ethmoid portion of the optic canal potentially causing optic nerve compression at the time of injury or later when the facial deformity is repaired; therefore it must be detected initially.

5. Both trauma and vascular shear injuries can cause cytogenic (positive MR diffusion) injury. When MR diffusion is positive, these areas will undergo tissue necrosis and end up as encephalomalacia defects.