Search

The authors describe the use of intraoperative US for directing placement of depth electrodes for the localization of seizure foci prior to temporal lobectomy. They used this technique in seven patients (six undergoing temporal and one frontal resection), and encountered no complications.

Spinal dysraphism includes anomalies of midline fusion involving bony, mesenchymal, and neural elements. MR imaging of the spine was performed as the initial imaging technique to determine its role in the evaluation of 31 children when spinal dysraphism was clinically suspected or when radiographs revealed errors of ossification of the posterior elements (spina bifida). Correlation of surgical findings in 17 of 18 abnormal examinations and metrizamide myelography with CT in six of these cases indicated that accurate diagnosis was provided by MR in all instances. Examples of spina bifida aperta (spina bifida cystica)--including myelomeningocele, myelocystocele, and lipomyelomeningocele--and those of occult spinal dysraphism--such as dorsal dermal sinus, spinal lipoma, and tight filum terminale (thickened filum)--are presented. These cases show MR to be a reliable technique in the initial evaluation of these disorders.

Direct sagittal computed tomography (CT) and metrizamide myelography, in addition to standard axial CT, have proven most useful in evaluation of complex anomalies of the infant spine. Direct sagittal CT was performed by placing the entire infant sideways and supine within the gantry after metrizamide was injected. This technique was performed in six infants with diagnoses of lipoma with dysraphism, lipomyelomeningocele, lipomyelocystocele, lumbosacral agenesis with cord regression, capillary hemangioma, and vertebral osteomyelitis. The technique showed the relation and/or extension of lesions in the dorsal ventral plane, particularly the presence or absence of subarachnoid, enteric, or genitourinary communication. Spinal and paraspinal anatomic detail was also demonstrated beautifully.

Three children were examined who had surgery to remove gangliocytomas in order to control seizures that were refractory to medical therapy. The CT characteristics of gangliocytomas are those of a hyperdense lesion that does not demonstrate contrast enhancement. The MR findings show a region of mixed signal intensity on T1-weighted and proton-density images, and decreased signal intensity on T2-weighted images. Little mass effect, if any, is seen with these lesions.

Five cases are presented to demonstrate the computed tomographic (CT) spectrum of holoprosencephaly. The classifications of alobar, semilobar, and lobar types A and B holoprosencephaly are each represented, with an additional case of semilobar holoprosencephaly complicated by a subdural effusion.

Radiographic findings are reviewed in 31 children with primitive neural ectodermal tumors seen at the Hospital for Sick Children from 1962 through 1983. Seventeen children were initially evaluated with computed tomography (CT). Ten of these had both CT studies and angiography. The tumors were large, irregular, typically iso- to hyperdense, and showed dense, heterogeneous contrast enhancement. Cysts were present in 65% and calcifications in 71% of cases. The angiographic findings were nonspecific, ranging from avascular to markedly vascular. Although these tumors were usually found in the cerebral hemisphere, particularly the frontal lobes, two cases are included of tumors arising elsewhere: one in the pineal and one in the suprasellar region. Epidemiologic data are reviewed.