Assessment of diagnostic technologies.

A general protocol for rigorous evaluation of diagnostic systems in medicine was applied successfully in a comparative study of two radiologic techniques. Accuracies of computed tomography and radionuclide scanning in detecting, localizing, and diagnosing brain lesions were assessed with a sample of patients in whom tumor had been suspected. The principal means of analysis was the "relative operating characteristic," which is unique in providing a measure of accuracy that is largely independent of decision biases. Computed tomography was found to be substantially more accurate than radionuclide scanning.

Pseudotumor cerebri due to partial obstruction of the sigmoid sinus by a cholesteatoma.

A 62-year-old man with pseudotumor cerebri (PTC) syndrome was discovered to have a cholesteatoma of the left mastoid. The mass indented the sigmoid sinus without occluding it. The PTC resolved postoperatively. To our knowledge, PTC has not been previously reported in association with a cholesteatoma. Additionally, this case demonstrated that a partial obstruction of the venous drainage of the brain may be sufficient to increase intracranial pressure.

Familial amentia, unusual ventricular calcifications, and increased cerebrospinal fluid protein.

A sibship originally reported by Friedman and Roy as showing severe mental retardation, strabismus, hyperactive tendon reflexes, lalling speech, and foot deformities was restudied. Three major additional findings were noted. The cerebrospinal fluid protein concentration was increased two to three times above normal in four siblings who were available for study. Radiographs of cranial structures in three siblings showed identical pathologic intracranial calcifications which correspond in distribution to the choroid plexus. The choroid plexus was not demonstrable in one patient when radiolabeled 99m-Tc-pertechnetate was injected without perchlorate. Neuropathologic findings in one sibling included small subcortical heterotopias and atrophy of the choroid plexus with encasement by glial fibrils. These findings denote a new heredofamilial neurologic syndrome associated with mental retardation and a disorder of choroid plexus.

Functional brain mapping using positron emission tomography scanning in preoperative neurosurgical planning for pediatric brain tumors.

OBJECT: The purpose of this report is to demonstrate the value of functional brain mapping using the positron emission tomography (PET) method for preoperative neurosurgical planning in children with brain tumors. Brain maps were used to characterize the relationship between potentially resectable tumors and functionally eloquent brain areas. METHODS: Five children, ranging in age from 3 to 13 years, with hemispheric brain tumors adjacent to eloquent cortex were studied. Magnetic resonance (MR) imaging was used to identify the brain tumors; PET imaging after injection of [18F] fluorodeoxyglucose (FDG), [11C]L-methionine (CMET), or a combination of the two was performed to grade the tumors; and a [15O] H2O uptake study was used to characterize the anatomical relationships of the tumors to functional cortex. The cortical activation maps were obtained during control periods and during behavioral tasks and were used to document motor, visual, and speech and language organizational areas. Wada tests were performed in two patients. Language and speech activation was concordant with the results of Wada testing. CONCLUSIONS: Functional brain mapping using PET scans and coregistered MR images provided the neurosurgeon with precise definitions of structural and functional cortical areas; this altered surgical management in some cases and/or was used to predict outcome. The combination of PET imaging with FDG and/or CMET and measurements of [15O] water uptake was useful in characterizing and grading tumors and instrumental in achieving effective neurosurgical planning. Postoperative results in the five cases suggest that preoperative functional brain mapping has the potential to improve outcome by defining a surgical plan to maximize resection and minimize the risk of neurological sequelae.

Value of computerized tomography scanning in syndromes associated with mental retardation: preliminary report.

The application of CT scanning in the evaluation of mental retardation syndromes is reviewed. In a representative sample of 35 institutionalized patients, the CT scan showed gross anatomic abnormality in most. However, these findings were diagnostic in only a small minority. Implications of this are discussed. In addition, the potential role of CT in the diagnosis of intercurrent diseases in the mentally retarded is considered.

Neuropathologic basis of computed tomographic scan abnormalities: a correlative method.

The accuracy of CT scan diagnosis can best be studied by comparing the postmortem scan to the corresponding pathologic specimen. To be valid, this comparison must be made in a precise manner: the CT image plane and the pathologic slice plane must correspond anatomically and must be juxtaposed in a specific point-to-point manner. A new method is described which correlates postmortem CT scans and postmortem pathologic specimens. Also considered are the utility and the limitations of matching CT absorption values to homogeneous pathologic lesions such as neoplasms, infarcts, hemorrhage and edema.

Clear plastic cerebral manifolds. A replacement for opaque three-way stopcocks.

A Morse coronary manifold was modified for cerebral angiography. The modified unit permits easier identification of foreign particles which could form emboli. It also expedites the procedure by simplifying continuous irrigation and facilitating reloading of the injector.

Computed tomography: immobilization of the head by dental holder.

Movement of the patient's head during computed tomographic studies with the EMI scanner causes some degradation of the quality of the examination. With sufficient movement, major artifacts appear which may obscure intracranial pathology. A simple method of head fixation, utilizing a dental mold, greatly reduces the incidence of unsatisfactory scans.

Cerebral infarction diagnosis by computerized tomography. Analysis and evaluation of findings.

CT has been found to be of value in cerbrovascular disease. In acute infarcts, the CT (before anticoagulation) excludes intracerebral hemorrhage. The CT may not exclude small petechial hemorrhagic infarctions (with negative cerebrospinal fluid). Angiography, otherwise, is more informative, disclosing ulcerative, irregular plaques, senosis, emboli, etc. In old infarcts, the CT may differentiate an old infarct from a tumor in a patient with focal seizures. Angiography and radionuclide scans are less informative. CT is a valuable investigative agent for clinico-anatomic correlation in cerebrovascular disease.

Computed tomography with the EMI scanner in the diagnosis of primary and metastatic intracranial neoplasms.

The findings and diagnostic results in 600 examinations of primary and metastatic intracranial neoplasms performed at one hospital with the EMI scanner are presented and the effectiveness of this method is compared with that of radionuclide imaging, cerebral angiography, and pneumoencephalography. The computed scan proved to be highly reliable in the diagnosis of glioma, cerebral metastases, meningioma, and acoustic neuroma.