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Recognition of the anatomic variations of the ophthalmic and middle meningeal arteries may be pertinent in tailoring the angiographic study to resolve a given clinical problem. An understanding of these anomalies is based on knowledge of the normal embryology. Unfortunately some early aspects of vascular development remain obscure. Fragmentary observations gleaned from the embryologic literature were correlated with selective and/or subselective angiography performed in 42 patients with such anomalies. This analysis has provided the basis for a tenable scheme for development of the ophthalmic and middle meningeal arteries as they relate to the embryonic stapedial artery. A classification for anomalies of these arteries is proposed based on deviation from this normal embryologic mechanism.

The accessory meningeal artery, originating from either the internal maxillary or middle meningeal artery, is predominantly an extracranial vessel. A minor branch of the artery enters the skull through the foramen ovale to supply the dura of the temporal fossa as well as the Gasserian ganglion. This intracranial branch may be demonstrated on angiography and may serve as a collateral between the external and the internal carotid arteries, with or without a complex intervening vascular network. The accessory meningeal artery may be identified as the arterial pedicle responsible for blood supply to meningiomas of the temporal fossa and possibly even to tumors of the Gasserian ganglion.

This could be the first case of bilateral agenesis of the internal carotid artery reported "in vivo." Angiogrpahic study has allowed us to recognize the anatomic details of this malformation. The absence of the two carotids is being compensated for by a trigeminal artery on the (left) side and by a hypertrophied accessory meningeal artery on the (right) side. Standard x-rays of the base of the skull (including tomography) revealed a dilation of the foramen ovale, related to the hypertrophied right accessory meningeal artery, and a complete atresia of the two carotid canals. This latter finding permits us definitely to postulate the nature of the congenital anomaly. Finally, the carotid agenesis was associated with the presence of three arterial aneurysms, situated respectively in each carotid territory and in the territory of the basilar artery.

In two cases with meningioma in the posterior fossa, the angiographic study, completed with the super-selective catheterization of the main pedicles, was followed by the technic of embolization. In the first case, a large meningioma, extending from the clivus to the left cerebello pontine angle, was supplied mainly by the ascending pharyngeal artery. In the second case, a huge meningioma, originating from the left inferior tentorial surface, was irrigated predominantly through the posterior branch of the middle meningeal artery and through the left occipital artery. Super-selective catheterization allowed us to better know in both cases the tumoral vasculature and to identify precisely the territory nourished by each supplying artery, from the external carotid artery.

Intrapetrous ceruminomas are rate tumors; only four cases have been reported in the literature. These had characteristics of cerebellopontine angle tumors. Our case had the characteristics of a tumor of the jugular foramen.

In chondrosarcomas, angiography may be helpful in confirming malignancy, delineating the anatomic extent and detecting recurrence. The angiographic findings in three chondrosarcomas are demonstrated including a vertebral one, abrupt narrowing of tumor vessels, neovascularlity and accumulation of contrast medium during the capillary phase. Changing calibre of arteries and neovascularity are better seen on selective angiograms and after subtraction technique.

Sixty-four measurements of CBF were performed in 8 monkeys in supine and in sitting position under various conditions of ventilation. The position of the body does not normally influence the response of brain circulation to CO2. The response is not different from normal with high insufflation pressure in supine position and the capacities to autoregulation seem to be maintained. In vertical position however there are no longer any significant relations between CBF and PaCO2, and the loss of autoregulation seems to occur earlier and to be more marked. Correlation of these findings to neuroradiologic data indicates that the cerebral venous drainage through the meningospinal plexus is enhanced in vertical position and that during intrathoracic hyperpressure the cerebral venous blood is retained in the jugular vein and meningospinal plexus, thus decreasing the cerebral venous pressure increase and maintaining a perfusion of brain tissue compatible with the survival of the animal.

Opacification of the cervical vertebral venous plexus was achieved by injecting contrast material into the upper part of the internal jugular vein while the lower portion of this vein was compressed externally with a tourniquet. The injection was easily performed via a percutaneous catheter which was advanced upwards into the jugular vein. Demonstration of the cervical plexus is made easier with the patients sitting up. Both sides of the plexus may be shown with a single injection if both jugular veins are injected simultaneously through bilateral catheters joined with a Y connector.

The angiographic and anatomical features of an anomalous communication between the intradural internal carotid artery and the anterior cerebral artery are described. Essential features of the anastomosis include an origin at, or close to, the origin of the ophthalmic artery, a course ventral to the ipsilateral optic nerve and anterior to the optic chiasm, and a termination near the anterior communicating artery. Although rare, the condition should be considered as an entity. The incidence of associated berry aneurysm and other congenital vascular anomalies is high.

The authors report three cases of epidermoid cyst of the spleen. A squamous cell lining was found in all three. One patient had a history of antecedent trauma, and in the surgical specimen the gross and histologic features were compatiible with splenic damage. No hematologic alteration was recognized on presentation. Angiography and spleen scanning were valuable aids in the diagnosis. All three patients were well 1 year after operation.

A characteristic "notch" in the petrous bone is described in relation to the superior outline of the jugular foramen. This notch seems to be a congenital anomaly and has a close relationship with ectasia of the dome of the internal jugular vein, as was demonstrated in two patients.