William P. Sanders

Absence of the supraclinoid internal carotid artery in association with intracranial aneurysms

Abstract We report a case of absence of the supraclinoid segment of the left internal carotid artery associated with hypoplasia of the ipsilateral internal carotid artery and anterior communicating artery aneurysm formation. We discuss the embryology probably responsible for this anatomical variant and show the imaging findings.

Intraventricular primary neuronal neoplasms : CT, MR, and angiographic findings

Intraventricular primary cerebral neuroblastoma and the more differentiated intraventricular neurocytoma are primary neuronal tumors that share common radiological characteristics. This article describes the imaging characteristics of these rare tumors using CT, MR, and angiography. We present one case of each neoplasm.

Venous restrictive disease in cerebral arteriovenous malformations

In a review of 151 patients with cerebral anterovenous malformations we found venous stenosis or occlusion in 69 cases (46%); involving the deep or superficial systems with approximately equal frequency. Although patients with uniquely deep venous drainage tended to have bled, there was no clear evidence that venous restrictive changes promoted hemorrhage.

Cervical Spine Injury: MR Imaging

The accurate diagnosis of cervical spine injuries is important because of the possible short-term mortality and longterm morbidity associated with them. Plain radiography is the initial imaging modality in most patients with suspected traumatic injury to the cervical spine. Unlike MR, CT does not allow adequate evaluation of the spinal cord and soft tissues, so it is used primarily for the evaluation of bony integrity. MR often is used when the initial plain radiographic and CT workups are negative but the clinical evaluation is persistently abnormal. MR also is the modality of choice for the diagnosis of spinal cord, intervertebral disc, and ligamentous and other soft tissue injuries of the cervical spine. However, despite faster acquisition time and improved imaging techniques in MR evaluation, plain radiography and CT continue to be the initial standard imaging modalities in the diagnosis of cervical spine injury. Cervical spine injuries are not common in blunt trauma patients, but the clinical outcomes associated with these injuries make them significant. Cervical spine injury is seen in 2.4% of blunt trauma patients who undergo cervical spine radiography. Of these cervical spine injuries, more than two thirds are clinically significant and almost two thirds involve vertebra C2, C6, or C7.1 The incidence of cervical spine dislocation is about 20% that of cervical spine fractures, and is most likely to occur at the C5-C6 or C6-C7 level. Atlantooccipital and C1-C2 dislocations account for only about 2.2% and 10% of total dislocations, respectively.1 This article focuses on the current clinical status of MR imaging for traumatic spine injuries, as well as MR features and the usefulness of various pulse sequences in different types of cervical spine injuries.

Proton MR Spectroscopy of Brain Lesions

In vivo MR spectroscopy (MRS) is based on the principle of chemical shift, in which the frequency of precession of the nucleus is proportional to the strength of magnetic field. Over the last decade, MRS has progressed from an experimental modality to a clinically useful imaging tool. Although MRS f