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Biomedical subjects

W F Conway

Publications and source records attributed to W F Conway.

49 records · Page 3Linked to original sources
PubMed1989

Non-neoplastic lesions of vertebral bodies: findings in magnetic resonance imaging.

This paper presents examples of non-neoplastic lesions of the spine that produce focal or diffuse signal alterations on MR images, and that may, therefore, be confused with metastases or primary neoplasms. Examples include endplate changes associated with degenerative disk disease, hemispherical spondylosclerosis, osteoporotic compression fractures, Paget's disease, focal and diffuse fatty infiltration, osteomyelitis, and changes associated with various arthritides. Distinguishing signal intensity characteristics on T1 and T2 weighted images and distinctive morphology are emphasized.

Fractures, Bone↗
PubMed1989

Temporomandibular joint motion: efficacy of fast low-angle shot MR imaging.

One hundred temporomandibular joints (TMJs) in 62 symptomatic patients and two healthy volunteers were prospectively examined with T1-weighted spin-echo and fast low-angle shot (FLASH) gradient-echo sequences. FLASH sequences were performed during opening of the mouth and provided a pseudodynamic depiction of TMJ motion. In 49 joints, FLASH sequences provided information that potentially influenced the therapeutic approach to the patient. This information was not available from standard T1-weighted images. The additional information fell into four general categories: (a) determination of the exact time of disk recapture, (b) distinction of normal variants from pathologically displaced disks, (c) clarification of discrepancies found between clinical examination results and T1-weighted images, and (d) elimination of motion degradation of images.

Adult↗
PubMed1989

Three-compartment wrist arthrography: use of a low-iodine-concentration contrast agent to decrease study time.

To decrease examination time, the authors used a contrast agent with a low iodine concentration for three-compartment (radiocarpal joint, distal radioulnar joint, midcarpal compartment) wrist arthrography. The material was used in 24 patients. Many patients demonstrated dissipation of contrast material in the radiocarpal joint by 30 minutes after injection. By 45 minutes, all patients demonstrated sufficient dissipation to permit the second injection. The technique produces diagnostic images and reduces the time required for the study.

Diatrizoate Meglumine↗
PubMed1989

X-linked hypophosphatemia.

X-linked hypophosphatemia is a common cause of metabolic rickets in children in this country. The gene defect is localized to the Xp22 region in man. Research into this disorder has been enhanced by the discovery of a mutant gene named Hyp on the X chromosome of mice that produces a syndrome similar to the human disease. These mutant genes in humans and mice alike result in low renal tubular reabsorption of phosphate, rickets, and osteomalacia. The renal synthesis of 1,25-dihydroxyvitamin D is unresponsive to low phosphate stimuli in both. A second mutant gene on the X chromosome of mice, Gy, also causes low renal tubular reabsorption of phosphate. The underlying defects in both the human disease and the mouse models are unknown. The availability of these murine models should advance our understanding of this clinical disorder and provide an environment for the testing of novel therapies.

Animals↗
PubMed1988

Dynamic magnetic resonance imaging of the temporomandibular joint using FLASH sequences.

Magnetic resonance imaging (MRI) is a suitable modality for the visualization of the temporomandibular joint (TMJ) in both normal and pathologic conditions. Until recently, MRI had been unable to provide diagnostic dynamic images of the TMJ during opening. A series of 30 TMJ MRI examinations of 17 symptomatic patients and two normal volunteers (15 to 43 years old; 14 men and five women) was performed. Fast low angle shot (FLASH) sequences were used to provide a series of dynamic images of the TMJ in various phases of opening. In 30% of the joint examined, FLASH sequences contributed clinically significant information not available with standard T1-weighted sequences. These results suggest that FLASH images are particularly useful in distinguishing normal disc variants from pathologic conditions in which the disc is displaced anteriorly to a mild extent. The short imaging time of FLASH sequences decreases motion artifact in patients who have difficulty remaining still during the examination.

Adolescent↗
PubMed1986

Carpal avascular necrosis: MR imaging.

The authors evaluated the use of magnetic resonance (MR) imaging in diagnosis of avascular necrosis (AVN) of carpal bones by examining 21 patients with wrist pain and two healthy volunteers. MR images were compared with conventional radiographs in every case and with bone scintigrams in 18 cases. MR imaging was slightly less sensitive than bone scintigraphy in depicting AVN, but in patients who were imaged with long repetition time (TR)/long echo time (TE) sequences in addition to short TR/short TE sequences, MR imaging was found to be more specific. While the authors believe that bone scintigraphy remains the screening test of choice for patients with wrist pain and normal plain radiographs, MR imaging promises to add significant diagnostic information in cases in which bone scans are abnormal.

Adult↗
PubMed1986

Breakage of the patellar component of a kinematic total knee arthroplasty. A case report.

Most complications of total knee arthroplasty have been of a general nature (ie, infection, pulmonary embolus, nerve palsy), or have involved either the tibial or femoral components. Occasionally, problems involving the patellar implant have been described including subluxation/dislocation, soft tissue impingement and patellar fractures. This article provides the first description of a new complication, fracture of the patellar implant at the stem-button interface.

Humans↗
PubMed1985

The carpal boss: an overview of radiographic evaluation.

The carpal boss, an unmovable bony protuberance, is located on the dorsum of the wrist at the base of the second and third metacarpals adjacent to the capitate and trapezoid bones. This bony prominence may represent degenerative osteophyte formation and/or the presence of an os styloideum, an accessory ossification center that occurs during embryonic development. When this condition is symptomatic, patients present with complaints of pain and limitation of motion of the affected hand. The symptoms of carpal boss may result from an overlying ganglion or bursitis, an exterior tendon slipping over this bony prominence, or from osteoarthritic changes at this site. Radiographically, the view that best profiles the separate os styloideum is a lateral view utilizing 30 degrees of supination and ulnar deviation of the wrist. Once a diagnosis has been made, treatment can range from the use of nonsteroidal antiinflammatory medication and limited use of the wrist to surgical excision of the anatomic abnormality.

Bone Diseases↗
PubMedDate not supplied

Radiology of maxillofacial trauma.

There has been a rising incidence of maxillofacial injuries during the past decade as a result of an increasing number of assaults and motor vehicle accidents. The maxillofacial region is one of the most complex areas of the human body, and the radiographic imaging of this region becomes even more difficult in traumatized patients because of their clinical condition and their inability to cooperate. Imaging modalities used in the evaluation of the traumatized maxillofacial region include conventional (plain) films, tomography, panoramic radiography, computed tomography, three-dimensional computed tomography, DentaScan, and magnetic resonance imaging. Each modality is discussed with regard to technique, advantages, and disadvantages. Plain films and computed tomography, the modalities that are used most in evaluating maxillofacial structures, are discussed in more detail. The normal anatomy and radiologic features are presented for both of these modalities. Radiographic evaluation of maxillofacial injury begins with a knowledge of the direct and indirect radiographic signs of injury seen on most imaging modalities. Computed tomography also has allowed a method of classifying facial fractures that is based on the involvement of the facial buttresses or struts. Three horizontal, two coronal, and five sagittal oriented struts are described. Limited fractures are differentiated from transfacial fractures by the lack of involvement of the pterygoid plates in the limited fractures. Limited fractures also can be subclassified as solitary (fracture of a single strut) or complex (fractures of multiple struts). A portion of the orbit is involved in almost every form of facial fracture; therefore, evaluation of facial injuries should always include the orbital structures. Although both can occur simultaneously, orbital injuries can be divided into soft tissue and bony vault injuries. Similar to midface fractures, orbital fractures also can be classified as solitary (fracture involves a single wall) or complex (fracture involves more than one wall or a part of a midface fracture). Computed tomography is of great value in evaluating both forms of injury. Magnetic resonance imaging is becoming increasingly important in the evaluation of orbital soft tissue injuries. Classification of midface injuries includes the solitary strut fractures and the complex strut fractures. Solitary strut fractures include fractures of the nasal arch, zygomatic arch, and isolated sinus wall fractures. Complex strut fractures include the nasal complex fractures, zygomatic (tripod) and zygomaticomaxillary fractures, transfacial fractures (LeFort fractures), and facial smash fractures. Each fracture type and its radiographic appearance are discussed.(ABSTRACT TRUNCATED AT 400 WORDS)

Female↗