PMC3463834_01
A 25-year-old woman with a gunshot wound to the right cerebral hemisphere. (a) computed tomography (CT)-scout image anterior view and (b) lateral view. Arrows demonstrate the right parietal blowout fracture representing the exit wound. (c) Admission CT, axial views in bone windows, clearly showing the right side shattered calvaria, which was likely acting as a hinge-craniotomy thus accommodating some swelling and at the same level (d) soft tissue windows, demonstrating the extensive multilobar hemorrhagic contusions caused by the pressure wave. (e) Immediate postoperative scan after a wide hemicraniectomy with expansile onlay duroplasty. (f) Postoperative scan after the patient had undergone delayed reconstruction with an allograft cranioplasty as indicated by the arrows
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F1
Imaging highlights:Head CT demonstrated a bullet trajectory through the right cheek exiting the right parietal skull with no retained bullet fragments with a blow-out fracture of the right parietal skull [Figure 1a and b]. There was intraparenchymal hemorrhage of the right temporal lobe with some midline shift and blood in the temporal horn of the right lateral ventricle [Figure 1c and d]. Despite a low GCS with a unilateral blown pupil, several factors were in this patient's favor, namely: a low and lateral trajectory of the bullet; an intact right orbit; no injury to the proximal middle cerebral artery (MCA) and its branches; no scatter of displaced bone fragments to cause further parenchymal injury; and the function of the blow out fracture acting as a "hinge hemicraniectomy," thus effectively decompressing the swollen brain [Figure 1c]. A right temporal lobectomy was performed and an intracranial pressure (ICP) monitor was inserted on the left side [Figure 1e].
PMC3463834_02
A 30-year-old woman with a gunshot wound to the back of the head. (a) computed tomography (CT)-scout image anterior view and (b) lateral view. Arrows demonstrate the left suboccipital target site with an intact bullet (c) Admission CT, axial views in bone windows, showing the bullet which was lodged behind the petrous bone (d) Soft tissue windows, demonstrating the focal posterior fossa hemorrhage near the cerebellopontine angle, but leaving an intact brain stem. A second significant hemorrhage/collection under the occipital bone is visible possibly originating from the sinus. Note the dilated temporal horns bilaterally indicative of obstructive hydrocephalus prior to external ventricular drain insertion. (e) Immediate postoperative scan after a wide bilateral suboccipital midline craniectomy with expansile onlay duroplasty. (f) This scan shows a postoperative scan of the same slice location in soft tissue windows after decompression as indicated by the arrows
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F2
History:This 30-year-old woman sustained a solitary close range GSW to the left side of the back of her head [Figure 2a and b]. An intraoperative right-sided external ventricular drain (EVD) was inserted prior to performing a bilateral suboccipital craniectomy with evacuation of the blood clot without disturbing the lodged bullet fragment [Figure 2e and f].
PMC3463834_03
A 26-year-old man with a gunshot wound to the right ear and orbit. (a) Computed tomography (CT)-scout image anterior view and (b) lateral view. Double arrows demonstrate the entry site at the right zygoma with a completely disintegrated bullet. (c) Admission CT, axial views, bone windows, showing the metal artifacts from the bullet case, which was scattered along the sphenoid bone. (d) Preoperative coronal reconstructions of the bone windows, demonstrating the midline crossing bullet trajectory as indicated by the arrows (star represents ricochet point). Note that the path does not cross a sinus or the ventricles. (e) Immediate postoperative result also in coronal reconstructions after a wide right hemicraniectomy with duroplasty. (f) Postoperative CT scan on the same day in soft tissue windows after decompression as indicated by the arrows. Note the new left frontal hemorrhagic contusion from the bullet fragment that was bounced off the inner table at the ricochet point
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F3
Imaging highlights:CT scan showed multiple retained bullet fragments primarily on the right extracranial aspect of the skull but penetrated bilaterally into the intracranial compartment [Figure 3a-c]. The bullet entry point through the right middle temporal fossa was low and generated ricochet fragments in the left frontal area [Figure 3c]. There was also a right temporal intraparenchymal hematoma with associated subarachnoid hemorrhage [Figure 3d and e]. A wide and low right-sided hemicraniectomy was emergently performed with splitting of the right sylvian fissure, identification, and clipping of 2 avulsed branches of the proximal MCA [Figure 3e-h].
PMC3463834_04
A 26-year-old woman with a penetrating gunshot wound to the head. (a) Computed tomography (CT)-scout image anterior view and (b) lateral view. Several arrows demonstrate the right frontoparietal entry site and a completely disintegrated bullet. (c) Admission CT, axial views, bone windows, showing the metal artifacts from the bullet case, which was scattered along the path. (d) Admission CT, axial views, corresponding soft tissue windows, also showing metal artifacts from the bullet case as well as bone fragments, scattered along the path and some perifocal hypodensity likely indicating edema. (e) Preoperative CT, coronal reconstructions in bone windows, demonstrating the midline crossing bullet trajectory from left to right as indicated by the arrows. Note that the matching CT venogram in (f) shows that the path did not cross the superior sinus or the ventricle
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F4
Imaging highlights:CT showed a right frontoparietal fracture with several displaced bone fragments and a large parietal intraparenchymal contusion [Figure 4a-c]. The bullet passed through the falx, causing a subdural hematoma and crossed into the left parietal lobe before exiting the left side of the skull [Figure 4d-f].