1. Head Trauma
In this unit we are going to discuss head trauma and its presentations.

2. Neurologic Evaluation
X-ray CT
MRI
Angiography
Imaging techniques suitable for use in neurologic evaluation including x-ray, CT, MRI, and angiography.

3. Right occipital fracture
Plain film evaluation is useful, in cases of significant head trauma, although the yield for identifying fractures is relatively low. In this individual, in the occipital region there is lucency, as indicated by the arrows, extending to the occipital bone, representing a linear non-displaced skull fracture.
Linear lucency representing linear skull fracture

4. Depressed Skull Fracture
Depressed skull fractures may present another fashion. They can present on the standard radiograph as a zone sclerosis as we see on the film on our left, in the region of the right frontal parietal region. Overlapping bone fragments lead to an area of sclerosis rather than to a lucency. The accompanying axial CT scan demonstrates the depression of at least 2 bony fragments in the frontal-parietal region on the right side, as demonstrated at the arrows.

5. Epidural Hematoma
Lenticular vascular void adjacent to the parietal bone on angiography
Prior to the advent of CT scanning, contrast angiography may have been used in case of head trauma in an attempt to identify the presence of epidural or subdural hematomas. In this instance we see a lenticular vascular void adjacent to the parietal bone on this angiogram obtained during the capillary phase. This void is a result of fluid collection in the epidural location.

6. Epidural Hematoma High density area Lens shaped Right parietal
Confined to sutures
On CT scanning, an epidural hematoma will appear as a high density area between the skull and brain parenchyma, blood typically being of a higher attenuation than adjoining brain matter. The epidural hematoma will be lens-shaped because of the fact that this collection is confined to the suture lines. in this particular instance, in the right parietal region. This confinement to suture is a hallmark finding in epidural hematomas.

7. Subdural Hematoma Balanced (upper image) and T2 image
Band like high signal along right lateral brain surface
Crescentic shape
Represents methemoglobin resulting from subdural bleed
Compare to epidural
On this MRI examination consisting of balance and T2 images, in the upper and lower images, we see a band-like area of high signal along the right lateral brain surface. Note that in this instance, this is not confined to the sutures. It does not take on a lenticular shape as we had noted in the epidural hematoma. This crescentic shape is quite typical of subdural hematomas. The high signal, as a result of met hemoglobin resulting from the subdural hematoma, or subdural bleed. Please compare this to the prior image of epidural hematoma.

8. Acute Subdural Hematoma
In this acute subdural hematoma, we see extensive extravasated blood along the left cerebral periphery. We also note significant mass effect with compression of the ventricles to the right side, and displacement to the right side across the midline. We also note that is relatively low attenuation of the left hemisphere as a result of edema.
High attenuation collection crossing sutures
Mass effect with midline shift

9. Chronic Subdural
In another individual we look at an MRI examination, and in this case we note the presence of crescentic high signal areas bilaterally outside of the brain’s parenchyma between, the brain parenchyma and the adjoining bone. This collection appears larger on the right side than the left side. This is a result of the chronic bilateral subdural hematoma.
Crescentic high signal bilaterally larger on the right
Represents chronic subdural bleeding

10. Subdural – Epidural Compared
Here, compare the subdural to your left and the epidural to your right as far as their extent in their configurations.

11. Parenchymal Bleed Intraparenchymal hematoma No enhancement
Deep left parietal white matter
Oval high attenuation (blood)
Surrounding low attenuation (edema)
Mild mass effect
Another result of head injury can be the development of an intracranial hemorrhage. In this individual, note the oval area of increased attenuation identified in the deep parietal region. This representing intraparenchymal hematoma. There is no enhancement on the contrast-enhanced portion examination. All the density we see here is as a result of the blood, this located in the deep white matter on the left side. Surrounding low attenuation represents the presence of some edema as a result of the chemical effect of blood within the brain parenchyma. There is slight mass effect, with slight deviation of the midline structures to the right side in this individual.

12. Subdural – Epidural – Parenchymal Compared
On this slide I’ve tried to show all three, subdural, epidural, and parenchymal hemorrhage on this single slide so you can have an opportunity to compare and contrast.