0000000000048496
AUTHOR
Wolfang Meese
Computed Tomography in Processes at the Base of the Skull and in the Skull Vault
Many CT systems allow detailed examination of the bony structures of the base of the skull and the vault. Elimination of the waterbox and enlargement of the opening of the gantry allows free positioning of the head, use of coronary projections, and studies of the base of the skull. A high-resolution matrix (320 × 320 for the EMI 5005 used in most of the studies in our series) provides a high degree of accuracy. A number of authors has reported on the use of computed tomography in studying the base of the skull, especially for planning surgical proce duresor radiation therapy (Liliequist and Forsell 1976; Bradac et al. 1977 b; Bradac et al. 1977c; Bradac et al. 1978; Hammerschlag et al. 1977…
Technique of CT Examination
The three study groups used the same CT systems during the investigation period : the EMI Mark I head scanner from 1975 until June 1977 and the EMI CT 1010 head scanner from the middle of 1977, with the Diagnostic Enhancement Package since March 1980. Special studies of the base of the skull were performed with an EMI CT 5005 body scanner (Department of Radiology, Klinikum Steglitz, Free Universityof Berlin).
Computed Tomography in Nonneoplastic Space-Occupying Intracranial Lesions
A number of nonneoplastic intracranial space-occupying lesions may resemble neoplasms in the CT scan, and definitive diagnosis is not possible with CT studies alone in many cases. Misinterpretations are possible, even when all clinical data are considered in the interpretation of the CT scan. However, the most accurate possiblepreoperative diagnosis is a prerequisite for decisions on therapeutic strategy and surgical approach. Therefore some cases may require the full range of conventional neuroradiological techniques and careful consideration of clinical findings for correct interpretation of the CT scan with its consequences for therapy. Table 6 summarizes the most common alternatives in …
Effect of Computed Tomography on Diagnosis of Neurological Disease
Computed tomography is generally considered to be the most reliable and, indeed, the definitive diagnostic technique for demonstration of brain tumors. Approximately 98% of intracra-nial lesions are detected with CT. However, extremely high sensitivity is not the only advantage of CT in diagnosis of intracranial tumors. Accuracy in determining histological type, visualization of anatomical relations to important brain structures, knowledge of the growth pattern, and evidence of space-occupying effects of the tumor are at least as important for the neurosurgeon. In effect, CT studies allow definition of the entire complex “intracranial space-occupying process” by means of a single procedure …
Computed Tomography in Orbital Lesions
Lesions in the orbits are characterized by unilateral or bilateral proptosis and/or disorders of ocular motion. Before the advent of computed tomography diagnosis was made on the basis of conventional radiological studies of the skull and the orbits as well as with ultrasonog-raphy, fluorescence angiography, phlebography of the ophthalmic vein, and arteriograms of the internal and external carotid arteries. The introduction of CT has brought about a correspondingdecline in the use of invasive procedures (Wende et al. 1977).
Computed Tomography in Brain Tumors
Craniocerebral injury and brain tumor are the two most important indications for CT studies. There is unanimous agreement that computed tomography is unequalled in its diagnostic accuracy in demonstration of intracranial tumors. Our own experience is based on observations in 3,750 patients with brain tumors or cerebral metastases who were studied in the period from December 1974 to March 1980 (Table 1). Initial CT studies demonstrated the intracranial tumor or tumors in 3,589 cases (95.7%). Several CT examinations were necessary for diagnosis of a brain tumor in 112 patients (3.0%). Other diagnostic procedures or postmortem studies revealed a brain tumor which had not been demonstrated with…
Classification of Intracranial Tumors
L. Bruns (1914) stated in Krause’s “General Neurosurgery” that brain tumors included all neoplasms growing within the cranial cavity and that these might be divided into three groups: (1) genuine tumors, (2) granulomatous lesions, and (3) parasites. Current use of the term “brain tumor” is more precise and limited to the first of L. Bruns’ categories. Even so, brain tumors represent a large and inhomoge-neous group. The comparison and evaluation of such a diverse set of observations is only possible after making a systematic classification of pertinent data.