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In emergency cases and traumatic head cases, CT scanning has completely changed the diagnostic method and angiography can in most cases be avoided. Not only can a proper diagnosis be set concerning intracranial bleedings or hematomas of different kinds but also additional information which earlier with help of angiography were not available can now be diagnosed. The article discusses the principles for using CT scanning as a diagnostic method in traumatic and emergency patients and discusses also the limitations and benefits with this method compared with angiography.

Metrizamide (Amipaque) is a new water-soluble contrast agent for use in the intrathecal space. Extensive animal and clinical studies have demonstrated its low toxicity. The advantages to the use of metrizamide include the fact that it is miscible with cerebrospinal fluid and can fill narrow spaces, is sufficiently radiopaque to outline delicate structures within the central nervous system, is completely resorbed from the subarachnoid space, and, to date, has not been implicated in the formation of adhesive arachnoiditis. Application of metrizamide to the evaluation of neurologically diseased patients has included myelography, intracranial cisternography, and ventriculography, as well as various techniques in conjunction with computerized tomography. These various uses of metrizamide are discussed together with some indications and advantages. Metrizamide has now replaced Pantopaque and gas as the most commonly used intrathecal contrast agent at the University of Texas Health Science Center at Dallas.

The communication between the subarachnoid space and the surgically created tumor cavity in glioma patients was evaluated by metrizamide cisternography. It was necessary to know the presence or absence of such a communication to determine the route of administration of autologous lymphocytes as a form of immunotherapy. The contrast injections were made either into the spinal subarachnoid space or directly into the tumor cavity. The presence of communication was demonstrated and followed by computerized tomographic (CT) scanning. The results were also corroborated by comparing the white cell counts in the fluid from the tumor cavity and the spinal subarachnoid space 24 hours after autologous lymphoid cell infusion. In only two of seven patients was a communication present. In the five patients without a communication, the blocks were at the tentorial hiatus (one patient), due to a nonpatent subarachnoid space over the cerebral convexity (two patients), and the result of adhesions at the pial margin of the tumor cavity (three patients). In addition, certain limitations in the use of computerized tomography in the evaluation of glioma patients are demonstrated. These problems include the effects of steroids on tumor size, the poor correlation between “enhancement” on CT scan and tumor recurrence, and the difficulty of differentiating metrizamide and hemorrhage by CT scan in the immediate postoperative period.

The blood-brain barrier seems to be an important factor in drug access to malignant brain tumors. Successful experimental reversible disruption of the blood-brain barrier in animals provided the basis for a clinical evaluation of osmotic disruption in five patients with primary and metastatic malignant brain tumors. Good to excellent blood-brain barrier disruption was achieved in four patients with a single nontransient complication, a superficial wound infection at the burr hole site in the first patient. Reversible, transient osmotic barrier disruption was achieved 15 times in five patients without additional toxicity. Computed tomography and radionuclide brain imaging were shown to be useful noninvasive monitors of the adequacy and extent of barrier disruption. These studies also provide further evidence that the barrier is at least partially intact in human tumors because in one patient a metastsis was seen only after barrier disruption.

Interpretation of the angiographic findings in posterior fossa angiography can be improved by a simple angiotomographic device which gives a midline tomography of the posterior fossa. Especially the vessels around the brain stem and close to the midline can be well seen and this is especially helpful with lesions in the brain stem and the anterior part of the posterior fossa. A few examples are given of midline angiotomography which demonstrates the advantages of this technique.

Reversible transient osmotic blood-brain barrier disruption was used to increase drug delivery to the brain. Methotrexate was administered 33 times to six patients with brain tumors after barrier disruption. No permanent complications were seen. Serial enhanced computed tomographic (CT) scans and quantification by CT tomographic number indicated that disruption increased drug delivery to the tumor and immediate surrounding brain. Neuroradiologic evaluation showed that drug in the tumor persisted longer after barrier disruption than when delivered without disruption. The concentration of methotrexate in spinal fluid did not correlate with the degree of barrier disruption measured by CT and radionuclide scans. In one patient an anatomic variation in the circle of Willis resulted in barrier disruption extending into the posterior fossa without ill effect. Osmotic blood-brain barrier disruption appears to be a safe procedure in man, able to increase drug delivery to both malignant brain tumors and surrounding brain parenchyma.

A case of cerebrospinal fluid rhinorrhea is presented in which routine diagnostic evaluation failed to disclose the site of leakage. Computerized tomography (CT) scanning with metrizamide, a nonionic contrast medium, provided not only documentation of the leak but also demonstrated the actual sinus involved. Metrizamide cisternography with CT scanning is a valuable technique in the evaluation of CSF rhinorrhea. It may only be used when an active leak is present. The patient described in this report lost several drops of CSF from the nose per minute in the face-down position. Neurotoxicity may be avoided by routine pre-examination medication with valium or phenobarbital. Mixing of the contrast agent with CSF. is diminished by injecting in the subarachnoid space at C1-C2. The methods used in this examination and their indications are described, and the literature concerning metrizamide toxicity and pharmacologic properties reviewed.

• Computed tomographic (CT) scans were prospectively obtained on 68 patients with previously untreated stages III and IV squamous cell carcinoma of the oral and pharyngeal cavity. We report herein the results of CT evaluation of primary disease arising in these sites, improvements in contrast-enhancement techniques, and CT assessment of the patient's condition after radiation or chemotherapy treatment. (Arch Otolaryngol1982;108:688-692)