Comparison of CT and MRI in diagnosis of cerebrospinal leak induced by multiple fractures of skull base

Abstract

Background: Multiple basilar skull fracture and cerebrospinal leak are common complications of traumatic brain injury, which required a surgical repair. But due to the complexity of basilar skull fracture after severe trauma, preoperatively an exact radiological location is always difficult. Multi-row spiral CT and MRI are currently widely applied in the clinical diagnosis. The present study was performed to compare the accuracy of cisternography by multi-row spiral CT and MRI in the diagnosis of cerebrospinal leak.

Methods: A total of 23 patients with multiple basilar skull fracture after traumatic brain injury were included. The radiological and surgical data were retrospectively analyzed. 64-row CT (mm/row) scan and three-dimensional reconstruction were performed in 12 patients, while MR plain scan and cisternography were performed in another 11 patients. The location of cerebrospinal leak was diagnosed by 2 experienced physicians majoring neurological radiology. Surgery was performed in all patients. The cerebrospinal leak location was confirmed and repaired during surgery. The result was considered as accurate when cerebrospinal leak was absent after surgery.

Results: According to the surgical exploration, the preoperative diagnosis of the active cerebrospinal leak location was accurate in 9 out of 12 patients with CT scan. The location could not be confirmed by CT because of multiple fractures in 2 patients and the missed diagnosis occurred in 1 patient. The preoperative diagnosis was accurate in 10 out of 11 patients with MRI examination.

Conclusions: MRI cisternography is more advanced than multi-row CT scan in multiple basilar skull fracture. The combination of the two examinations may increase the diagnostic ratio of active cerebrospinal leak.

Keywords: CT; MRI; cerebrospinal leak; diagnosis; multiple basilar skull fracture.

FIGURE 1.

A 43-year-old patient diagnosed with multiple basilar skull fracture induced by severe craniocerebral injury. Partial frontal bone and superficial arch were resected and cerebrospinal rhinorrhea was present 10 days after surgery (Right). CT showed multiple basilar skull fracture. The cerebrospinal leak location could not be determined because of the several defects in ethmoid and sphenoidal sinus. It was demonstrated by surgery that meninges defect was present at the site of ethmoid sinus (A, sagittal view; B, coronal view). Rhinorrhea disappeared after the surgery repair.

FIGURE 2.

Cerebrospinal fluid rhinorrhea was present after brain trauma in a male patient of 37 year old. CT scan showed multiple basilar skull fracture. Thin layer scan of high-resolution CT showed that frontal sinus communicated with nasal cavity and cerebrospinal leak in frontal sinus was the diagnosis (A, coronal view; B, sagittal view). The surgical exploration confirmed that frontal sinus was impaired and communicated with intracalvarium and rhinorrhea disappeared after the surgical repair.

FIGURE 3.

A male patient aged 21 years with severe craniocerebral injury. Surgery was performed to remove part of the frontal bone and contused brain tissue of frontal lobe. One week after surgery, cerebrospinal fluid rhinorrhea was present in left nose. CT scan showed multiple basilar skull fracture and failure in ethmoid sinus repair. MR cisternography showed that high-signal liquid was present in frontal sinus in the prone position (3A) but not in the supine position (3B) in T2-weighted image, thus cerebrospinal leak in frontal sinus was diagnosed. It was observed during surgery that the crack fracture was present in the posterior side of frontal sinus with damaged dura mater, which communicated with nasal cavity, and rhinorrhea disappeared after the surgery.