Fong Y. Tsai

Computed tomography of posterior fossa trauma.

Abstract A group of 1,700 cases of head trauma were reviewed to determine the incidence of posterior fossa injuries and to assess the value of computed tomography (CT) in their diagnosis and management. In 57 cases (3.3%), the most significant and primary injuries were within the posterior fossa. These included epidural hematoma (EDH), acute and chronic subdural hematoma (SDH), and parenchymal hemorrhage and contusion of the cerebellum and brainstem. The prognosis varies with the location and severity of the injury. Brainstem injuries are associated with a high mortality rate. Computed tomography proves particularly useful in the early recognition of brainstem injury. The demonstration by CT of obliteration of the cisterns surrounding the brainstem is a reliable sign of a grave prognosis in brainstem injury. Contrast enhancement is useful in demonstrating whether the dural sinuses are displaced, thus differentiating EDH from SDH. Except in the rare case of vascular injury unassociated with EDH, CT correlated with the neurological examination is an accurate method of determining the nature, location, and extent of significant posterior fossa injury. Scans of high quality are mandatory, and frequent supplementary contrast studies are recommended.

Diagnostic and prognostic implications of computed tomography of head trauma.

A total of 210 cases of head trauma were examined using noncontrast enhanced and contrast enhanced computed tomography scans. Evidence of contrast enhancement was seen in 97 cases (46%). Subdural hematoma and focal contusion were the most frequent entities demonstrating contrast enhancement. This finding was also frequently seen in patients with intraventricular hemorrhage (IVH) (5 of 17). Every one of the five patients in this series with IVH whose scans showed enhancement died, whereas out of the 12 whose scans showed no enhancement, five survived. Illustrative cases are presented. The authors feel that contrast enhanced scans are valuable in the evaluation of the full extent of head trauma.

Lipomas of the Corpus Callosum Associated with Frontal Dysraphism

Using computed tomography (CT), we have been able to identify the combined occurrence of lipoma of the corpus callosum and dysraphic lesions associated with frontal bone defects in two cases. In one case, there was a true encephalocele, and in the other case a lipoma with cartilaginous tissue was present. Such combinations are very rare; thus, the impetus to report these cases. The disorganization of the central nervous system was extensive in the first infant and was associated with profound developmental delay, while the second infant had much less anatomical abnormality, and development to date is normal. Bony defects (on skull films), typical appearances of lipoma of the corpus callosum, and characteristics of the dysraphic lesions (on CT) were seen. Angiography was obtained in the infant with a true encephalocele.

Solitary osteochondroma with spinal cord compression

Osteochondromas are unusual in the spine, and they are very rarely present with compression of the spinal cord. Two cases are reported with delineation of the tumor by metrizamide myelography and computed tomography.

CT myelography in spinal cysticercosis.

Four cases of spinal cysticercosis were found in a series of 356 cases of CNS cysticercosis studied neuroradiologically. Cysticercal cysts were seen to migrate within the spinal subarachnoid space on myelographic studies. All four patients presented initially with hydrocephalus, which supports the notion that spinal leptomeningeal cysts have migrated from an intracranial site of origin. Computed tomographic myelography (metrizamide) allowed better localization and definition of the spinal cysticercal lesions.

Localization of intracranial lesions utilizing the coronal suture as a landmark on axial computed tomography

Abstract The superior portion of the coronal suture is often easily identified by appropriately setting the window width and level of the CT scanners display system. It provides a valuable and practical reference point for the localization of intracranial lesions, particularly those above the level of the lateral ventricles, where fewer anatomical landmarks are available when using computed tomography.

Neuroradiology in Head Trauma

Radiological studies available for assessment of children with head trauma include plain skull X-rays, arteriography, computerized tomography (CT), air studies, echoencephalography, and radionuclide brain scanning. The radiological approach will vary, depending on whether the investigation is being carried out under the emergent circumstance of acute head trauma or whether the delayed consequences of trauma are being evaluated. Obviously, it is best to admit a child with an acute head injury to a hospital where CT, as well as facilities for emergency surgery are available.

Arterial digital subtraction angiography with particulate intravascular embolization and angioplasty

The authors are reporting their experience with arterial digital subtraction angiography to monitor particular intravascular embolization in hypervascular tumors and malformations and angioplasty. Arterial digital subtraction angiography may reduce the time of waiting for regular film developing and subtraction. The smaller amount of contrast material being used in arterial digital subtraction angiography minimizes the discomfort to the patients. It also prevents further renal damage in those patients with poor renal function. The arterial digital subtraction angiography may detect the early warning signs of embolotherapy. From the past experience, the authors have found that arterial digital subtraction angiography should be considered as a better alternative way to performing the particulate embolization and angioplasty than being monitored by conventional angiography.