Comparative anatomy of the middle cerebral artery, rhinal and endorhinal sulci, piriform lobe, entorhinal cortex, olfactory tubercule, anterior perforate substance, and hippocampus: A dissection study.

The literature describing the complex anatomy of the middle cerebral artery (MCA), lenticulostriate arteries, and recurrent artery of Heubner, does not discuss the comparative anatomy of the cerebrum, MCA, the recurrent artery of Heubner, and the relationship of the MCA with the rhinal sulci. The entorhinal literature does not detail the comparative anatomic modification of the rhinal and endorhinal sulci, piriform lobe and the hippocampus's compressed positional change in the temporal lobe. This investigation's objectives were to analyze the comparative anatomic modifications of the cerebrum, the MCA, lenticulostriate arteries, recurrent artery of Heubner, olfactory tubercule, anterior perforate substance, rhinal sulcus, endorhinal sulcus, piriform lobe, entorhinal cortex, and hippocampus.

Cerebral arterial and ventricular morphology of the dogfish (Squalus acanthias), American bullfrog (Rana catesbeiana), and green iguana (Iguana iguana): Arterial high-resolution micro-CT, dissection, and radiography study.

This study's objective was to investigate obtaining high-resolution micro-computed tomography (CT) imaging of the injected arterial circulation of the brains of the dogfish (Squalus acanthias), American bullfrog (Rana catesbeiana), and green iguana (Iguana iguana). No micro-CT images of the arterial morphology of the brains of these vertebrates were previously published. Micro-CT imaging was performed on brains that had the cerebral arterial and ventricular systems injected with a radiopaque barium-gelatin compound in the early 1970s.

Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans.

Purpose: An extensive literature has postulated multiple etiologies for aqueductal stenosis. No publications were found, discussing that evolutionary modifications might explain aqueductal anomalies. This study's objectives were to review the evolutionary modifications of vertebrates' tectum structures that might explain human aqueduct anomalies.

The cavernous carotid inferolateral trunk and persistent primitive maxillary arteries: analysis of dissected arterially injected fetal specimens and high-resolution micro-CT of the dog's anastomotic arteries.

Purpose: The presence of a persistent primitive maxillary artery is described in the literature dealing with the development of the cavernous carotid inferolateral trunk, and the relevant similarities of the cranial circulation of the human and dog. The literature includes no dissection photographs of the above-mentioned two human fetal arteries, only diagrammatic representations. This study's objectives were to analyze photographs of fetal dissections for the presence of these two arteries, and also investigate the possibility of obtaining, in preserved dog specimens, high-resolution micro-CT imaging of arteries homologous with the above-mentioned two human arteries.

Sphenoidal artery: review of the literature and analysis of a dissected arterially injected fetal orbit.

Purpose: The sphenoidal artery is considered a component of the complex and dangerous arterial anastomoses of the human orbitocranial region, particularly with the advent of interventional neuroimaging. The objective of this publication was to analyze the various descriptions of the sphenoidal artery in the literature as related to relevant photographs of a dissected arterially injected fetal middle cranial fossa and orbit.

Methods: Publications dealing with middle meningeal-ophthalmic arterial anastomoses, focusing on the sphenoidal artery, were reviewed.

High-Resolution Computed Tomography Imaging of the Cranial Arterial System and Rete Mirabile of the Cat (Felis catus).

The objective of this study was to investigate the possibility of obtaining high-resolution multiplanar computed tomography (CT) imaging of the cranial arterial circulation of the cat (Felis catus), the rete mirabile, and components of the skull, utilizing preserved cat specimens with an arterial system that was injected with a radiopaque contrast compound in the early 1970s. Review of the literature shows no high-resolution CT studies of the cat's cranial circulation, with only few plain radiographic studies, all with limited cranial vascular visualization. In view of the inability of the radiographic techniques available from 1970s to mid-2000s to provide high-resolution imaging of the arterial circulation within the intact skull and brain of the cat, without dissection and histologic sectioning and disruption of tissues, no further imaging was performed for many years.

MR imaging of the temporal stem: anatomic dissection tractography of the uncinate fasciculus, inferior occipitofrontal fasciculus, and Meyer's loop of the optic radiation.

Background And Purpose: The MR anatomy of the uncinate fasciculus, inferior occipitofrontal fasciculus, and Meyer's loop of the optic radiation, which traverse the temporal stem, is not well known. The purpose of this investigation was to study these structures in the anterior temporal lobe and the external and extreme capsules and to correlate the dissected anatomy with the cross-sectional MR anatomy.

Methods: Progressive dissection was guided by three-dimensional MR renderings and cross-sectional images.

Anatomic dissection tractography: a new method for precise MR localization of white matter tracts.

Background And Purpose: Several white matter tracts in the brain cannot be identified on MR studies because they are indistinguishable from the surrounding white matter. We sought to develop a method to precisely localize white matter tracts by correlating anatomic dissections with corresponding MR images.

Methods: MR imaging was used to guide anatomic dissection of the uncinate fasciculus.

MR imaging and histologic features of subinsular bright spots on T2-weighted MR images: Virchow-Robin spaces of the extreme capsule and insular cortex.

Purpose: To determine the cause and frequency of high-signal-intensity foci detected in the insular cortex and extreme capsule on thin-section, high-spatial-resolution, coronal, T2-weighted magnetic resonance (MR) images.

Materials And Methods: The authors assessed high-signal-intensity areas in the insular cortex and extreme capsule on coronal MR images obtained in 56 patients with seizure and five control subjects. Images were obtained with thin-section, high-spatial-resolution, T2-weighted, fast spin-echo; three-dimensional, spoiled gradient-recalled-echo; and fluid-attenuated inversion-recovery sequences.

The lamina rostralis: modification of concepts concerning the anatomy, embryology, and MR appearance of the rostrum of the corpus callosum.

Purpose: To study the anatomy and embryology of the lamina rostralis, and to determine whether the rostrum is, as frequently stated, the last section of the corpus callosum to develop.

Methods: The rostrum was analyzed in dissected adult brains and on MR studies in 300 patients with a normal corpus callosum and in 84 patients with a hypogenetic corpus callosum. MR images of intact fetuses and photographs of dissected fetal and adult vertebrate brains were also analyzed.

Embryology of the human fetal hippocampus: MR imaging, anatomy, and histology.

Purpose: To identify changes in the embryology of the hippocampus responsible for its adult anatomy.

Methods: Ten human fetal specimens ranging from 13 to 24 weeks' gestational age were examined with MR imaging. Dissections and histologic sections of 10 different specimens of similar ages were compared with MR imaging findings.

Detection of nerve rootlet avulsion on CT myelography in patients with birth palsy and brachial plexus injury after trauma.

Objective: Recent advances in neurosurgical treatment of traumatic and birth-related brachial plexus injuries require differentiation of preganglionic nerve rootlet avulsion from postganglionic lesions. The purpose of this study was to evaluate the efficacy of thin-section high-resolution CT myelography for revealing cervicothoracic nerve rootlet avulsion in patients with brachial plexus injuries before surgery.

Materials And Methods: We evaluated eight patients with posttraumatic or birth-related brachial plexus injury on cervical plain film myelography and high-resolution CT myelography before surgical exploration and repair.

The normal and abnormal genu of the corpus callosum: an evolutionary, embryologic, anatomic, and MR analysis.

Purpose: To define the normal and abnormal genu of the corpus callosum by examining its evolution and embryology and by analyzing its normal and abnormal appearance on MR images.

Methods: A reference line was drawn from the mamillary body through the anterior commissure and corpus callosum-the MAC line. This line was used to evaluate the genu in adult mammal brains, in human fetal brains, on MR images of 1800 patients with normal corpora callosi, and on MR images of 113 patients with callosal anomalies.

Limbic lobe embryology and anatomy: dissection and MR of the medial surface of the fetal cerebral hemisphere.

Purpose: To facilitate understanding of limbic lobe anatomy by showing embryologic transformations of the medial surface of the cerebral hemisphere.

Methods: Brains from fetal specimens ranging from 13 to 24 weeks of gestational age were dissected. Photographs were made of the medial surface of the cerebral hemisphere.

Hemifacial spasm caused by a tortuous vertebral artery: MR demonstration.

Hemifacial spasm is a symptom complex comprising involuntary, painless spasms of the orbicularis muscle that may progress to involve all facial muscles. It is frequently the result of compression of the facial nerve at its root exit zone from the brain stem by vascular loops or aneurysms of the posterior inferior cerebellar artery, anterior inferior cerebellar artery, vertebral artery, or cochlear artery. Coronal and axial T1-weighted images clearly depict the course of the facial nerve from the brain stem to the internal auditory canal and its relation to the vertebrobasilar system.

Intraventricular hemorrhage in a term neonate secondary to a third ventricular AVM. Case report.

An initially healthy infant born of an uncomplicated full-term gestation was brought for evaluation of the acute onset of vomiting, irritability, lethargy, and opisthotonus at 14 days of age. Computerized tomography demonstrated an intraventricular hemorrhage. Arteriography defined an angioma on the roof of the third ventricle which was successfully removed via the transcallosal interfornicial approach on the 34th day of life.

Pulsatile tinnitus arising from jugular megabulb deformity: a treatment rationale.

Pulsatile tinnitus is a rare presenting symptom in patients with enlarged jugular bulbs. We will describe three young women presenting with right pulsatile tinnitus associated with a megabulb deformity of the temporal bone. After extensive radiologic and audiologic evaluation, no vascular or bony abnormalities could be identified.

CT findings in a nasopharyngeal extramedullary plasmacytoma.

We report a case of an extramedullary plasmacytoma arising from the nasopharynx. The computed tomographic appearance of this rare tumor is discussed.

Temporal bone disease: a comparison between high resolution computed tomography and pluridirectional tomography.

Sixty-five patients with suspected ear disease were examined with CT, and abnormalities were detected in 42 of them; 58 of these patients also had pluridirectional tomographic examinations. Eighteen of the patients in whom abnormalities were detected underwent exploratory surgery. CT was useful in the diagnosis of tympanic membrane swelling, fluid in the middle ear, cholesteatoma, granulation tissue, and adhesions.

High resolution computed tomography of the osseous external auditory canal: 1. Normal anatomy.

This study of 34 normal ears was conducted in order to define more precisely the normal computed tomographic (CT) anatomy of the osseous external auditory canal. Great variability was found in canal configuration and its relationship to the temporal squama. The understanding of normal CT appearance of the various fissures along the anterior wall of the external canal is important to avoid mistaking fissures for fractures.

The choice of contrast agent for myelography in patients with nonpenetrating cervical spine trauma.

Forty patients with neurological deficits from cervical spine trauma had cervical myelography with metrizamide, gas, iophendylate, or a combination thereof. At a low dosage (less than or equal to 1.25 g I), metrizamide was found to be not only the most effective in demonstrating the spinal cord but also safe if used with a C-arm biplane fluoroscopic unit which has tomographic capability.