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Biomedical subjects

W R Smoker

Publications and source records attributed to W R Smoker.

At least 19 recordsLinked to original sources
PubMed1997

Cortical and subcortical T2 shortening in multiple sclerosis.

Low signal intensity on long-repetition-time MR sequences has been observed in deep gray matter structures in patients with multiple sclerosis. This T2 shortening most likely represents a nonspecific degenerative process. We recently observed T2 shortening in the pericentral cortical gray matter and subcortical white matter in a patient with severe multiple sclerosis and we postulate that this represents an additional manifestation of neural degeneration.

Adult↗
PubMed1997

Atypical skull base paragangliomas.

We present two cases of unusually large skull base paragangliomas. The first tumor was accompanied by marked bony destruction of the central skull base and multiple associated cysts. The second tumor arose along the petrous ridge, with a large intracranial component. The CT, MR imaging, angiographic, histologic, and electron microscopic findings of these unusual lesions are described.

Adolescent↗
PubMed1996

Nonatheromatous carotid artery disease.

Common and uncommon nonatheromatous diseases affecting the cervical carotid artery are discussed. Specifically, the radiographic and pertinent clinical features of cervical carotid artery congenital variants, dissection, fibromuscular dysplasia, Takayasu's arteritis, and infection are described. Catheter angiography continues to have an important role in the diagnosis of many of these conditions. Magnetic resonance imaging techniques are emerging as a useful adjunct to catheter angiography and occasionally may be the primary imaging modality for diagnosis.

Aortic Dissection↗
PubMed1996

The forgotten condyle: the appearance, morphology, and classification of occipital condyle fractures.

PURPOSE: To evaluate the appearance, morphology, and treatment of occipital condyle fractures (OCF). METHODS: Cases were collected by a retrospective and prospective analysis of teaching files and case logs. Patients' charts, when available, were reviewed for age, sex, mode of injury, physical examination, Glascow Coma Scale score, and associated injuries. Plain films and CT images were reviewed to determine OCF type and to assess for the presence of associated cervical spine and/or intracranial trauma. RESULTS: Fifteen patients with OCF, 13 occurring in a 43-month period, were identified. Ten patients were involved in motor vehicle accidents. Severity of closed head injury and associated clinical findings were variable. Three patients had associated cervical spine fracture. According to the Anderson and Montesano classification, two patients (13%) had type I OCF, eight patients (54%) had type II OCF, and five (33%) had type III OCF. Fourteen of the fractures were identified on screening trauma head CT scans. Treatment varied according to the presence of associated injuries and stability of the cervical spine. CONCLUSIONS: Although OCFs are rare, they will be encountered by most radiologists who see a significant amount of trauma. Type II OCFs were the most common fracture type in our series. Type III fractures were the second most common and potentially unstable. CT should be initiated at the level of the C-1 ring to screen for the presence of OCF in all patients who have suffered trauma.

Adolescent↗
PubMed1995

Hemorrhagic intracranial parenchymal metastases from primary retroperitoneal neuroblastoma.

An unusual case of parenchymal hemorrhagic metastases to the cerebrum and cerebellum in a child with retroperitoneal neuroblastoma is presented. While isolated parenchymal central nervous system (CNS) metastases have not typically been considered in association with neuroblastoma, review of the literature suggests an increased frequency of this manifestation, especially since 1980. Metastatic neuroblastoma should be included in the differential diagnosis of multiple hemorrhagic parenchymal brain lesions in the pediatric population.

Brain Neoplasms↗
PubMed1995

Oral cavity: anatomy and pathology.

The oral cavity and oropharynx comprise the upper portion of the aerodigestive tract. These two regions are distinguished from each other because pathologic processes differ in their presentations, prognoses, and histologic grades. The normal anatomy of the oral cavity, vestibule, and oral cavity proper is discussed and is followed by a discussion of the sublingual and submandibular spaces. The diversity of pathologic processes that occur in these regions is then presented as well as the more common pitfalls.

Humans↗
PubMed1995

Congenital anomalies of the cervical spine.

A wide variety of congenital pathology affects the cervical spine and underlying spinal cord. This article discusses commonly encountered conditions under the categories of osseous anomalies, Chiari malformations, dysraphic conditions, and skeletal dysplasias. Osseous anomalies tend to involve the upper cervical spine to a greater degree than the lower cervical spine. Chiari malformations warrant inclusion on the basis that they have many manifestations within the cervical spine. Dysraphic conditions resulting from failure of either primary or secondary neurulation are distinctly uncommon in the cervical spine compared with the lumbar spine and are, therefore, only briefly discussed. Skeletal dysplasias encompass a diverse group of uncommon entities but may produce significant radiographic abnormalities and may be associated with clinical symptomatology.

Cervical Vertebrae↗
PubMed1994

Craniovertebral junction: normal anatomy, craniometry, and congenital anomalies.

The craniovertebral junction (CVJ) comprises the occiput, atlas, and axis and is visible in most magnetic resonance (MR) imaging studies of the brain. Craniometric measurements used in radiologic assessment of CVJ anomalies include the Chamberlain line, Wackenheim clivus baseline, Welcher basal angle, and atlantooccipital joint axis angle. Most anomalies of the occiput are associated with decreased skull base height and basilar invagination, the latter being a primary developmental anomaly in which the vertebral column is abnormally high and prolapsed into the skull base. Occiput anomalies include condylus tertius, condylar hypoplasia, basiocciput hypoplasia, and atlanto-occipital assimilation. Most atlas anomalies produce no abnormal CVJ relationships and are not associated with basilar invagination. These anomalies include aplasias, hypoplasias, and clefts of the atlas arches and "split atlas" (ie, posterior arch rachischisis associated with anterior arch rachischisis). Except for fusion anomalies, abnormalities of the axis are primarily confined to the odontoid process and are not associated with basilar invagination. These anomalies include persistent ossiculum terminale, odontoid aplasia, and os odontoideum. With the widespread availability of MR imaging, which is well suited for evaluating the CVJ because of its direct sagittal imaging capabilities, renewed understanding of CVJ anatomy and anomalies is important for all radiologists.

Adolescent↗
PubMed1994

Hypoglossal nerve palsy: a segmental approach.

Hypoglossal nerve (cranial nerve XII) palsy is uncommon. Damage to this nerve produces characteristic clinical manifestations, of which unilateral atrophy of the tongue musculature is the most important. When these features are recognized, the radiologist, armed with knowledge of the normal anatomy of the area, can focus on each segment of the nerve in search of a cause. The hypoglossal nerve is divided into five segments: the medullary, cisternal, skull base, nasopharyngeal/oropharyngeal carotid space, and sublingual segments. Because each segment is usually affected by different disorders, localizing a lesion to a particular segment allows the radiologist to narrow the differential diagnosis. In this way, the most efficient imaging strategy for evaluation of the symptoms can be developed. Both computed tomography and magnetic resonance imaging are useful in assessing dysfunction of the hypoglossal nerve; the choice depends on the status of the patient and the preference of the radiologist.

Adolescent↗
PubMed1994

Musculoskeletal causes of spinal axis compromise: beyond the usual suspects.

The majority of cases of spinal canal compromise are caused by common pathologic conditions, including degenerative spondylosis, infection, trauma, and metastatic disease. However, there are other causes of spinal canal compromise that, though unusual, may be seen in everyday practice. Congenital abnormalities of the spine that may produce spinal canal compromise include the os odontoideum, hemivertebra, diastematomyelia, and achondroplasia. Arthritides and enthesopathies such as rheumatoid arthritis, ankylosing spondylitis, synovial cysts of the facet joint, calcium pyrophosphate dihydrate deposition or hydroxyapatite deposition, and ossification of the posterior longitudinal ligament or ligamentum flavum may lead to narrowing of the spinal canal. Primary spinal tumors and tumorlike lesions such as hemangioma, aneurysmal bone cysts, osteochondroma, and osteoblastoma may also cause spinal canal stenosis. Finally, Paget disease of bone may compromise the spinal cord. Radiologists should be aware of these unusual musculoskeletal causes of spinal canal compromise and their radiologic and clinical features.

Humans↗
PubMed1994

Atlantooccipital subluxation in a neonate with Down's syndrome. Case report and review of the literature.

Atlantooccipital subluxation (AOS) occurs in up to 63% of patients with Down's syndrome. However, presenting symptoms and the age at which preoperative screening becomes necessary have not been clearly delineated. Recently, a 16-day-old female with Down's syndrome and AOS presented to our institution. Following patent ductus arteriosus ligation, her neurological examination revealed trace movement, few spontaneous respirations, and left lower extremity clonus. Cervical spine radiographs revealed significant AOS. She was reduced and underwent a fusion from the occiput to C2. She gradually regained full strength and sensation. This case is the youngest example of AOS related to Down's syndrome described. It emphasizes the need for preoperative screening of all patients with Down's syndrome.

Atlanto-Occipital Joint↗
PubMed1994

Pulsatile tinnitus: recent advances in diagnosis.

Pulsatile tinnitus can often be a diagnostic problem. This communication reports the authors' experience on 100 patients with pulsatile tinnitus and describes a practical and effective diagnostic approach. Better understanding of the various etiologies of pulsatile tinnitus, coupled with the introduction of magnetic resonance angiography, in conjunction with magnetic resonance imaging, have made a major impact on the evaluation of this symptom in recent years. Cerebral angiography, previously performed on the majority of patients, is presently indicated in selected cases only. Intracranial hypertension, glomus tumors, and carotid atherosclerosis were the most common diagnoses made in our patients.

Adult↗
PubMed1994

Lesions of the craniovertebral junction.

There has been a renewed interest in the normal and pathologic lesions of the CVJ with the growth of MR imaging. A host of pathologies, both congenital and acquired, may manifest at the CVJ. Basilar invagination and basilar impression and their impact on the CMJ are readily diagnosed using a variety of noninvasive imaging modalities. Evaluation of the CVJ on cranial and cervical MR examinations should be a routine part of image interpretation.

Atlanto-Axial Joint↗
PubMed1992

The ostiomeatal unit and endoscopic surgery: anatomy, variations, and imaging findings in inflammatory diseases.

Recent and ongoing advances made in endoscopic surgical techniques require the radiologist to understand the anatomy and pathophysiology of the paranasal sinuses and nasal passage. Endoscopy and CT are complementary procedures, and, as such, the normal anatomic relationships and their CT appearances need to be well understood in order for radiologists to offer continued support as consultants to their clinical colleagues. In this article, we review the pertinent anatomy of the lateral nasal wall and paranasal sinuses, discuss the most frequently encountered normal variations that may predispose a patient to inflammatory sinus disease, outline imaging protocols for evaluation of this region, and introduce the reader to current endoscopic surgical techniques. Last, the imaging findings in various inflammatory processes involving the sinuses, as well as the local and regional complications associated with paranasal sinus inflammatory diseases, are presented.

Endoscopy↗