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Biomedical subjects

W F Conway

Publications and source records attributed to W F Conway.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of articular cartilage: radiographic and cross-sectional imaging techniques.

Many diagnostic modalities may be used to evaluate articular cartilage. Plain radiography remains the preferred initial study for cartilage evaluation, although even specialized views such as weight-bearing, tunnel, and flexion lateral projections are insensitive in the detection of early cartilage loss. Compared with newer modalities, conventional arthrography has limited capacity for the assessment of cartilage. Computed tomography performed after intraarticular injection of contrast material (ie, CT arthrography) has improved accuracy but is essentially limited to the axial plane. Magnetic resonance (MR) imaging, with its superb soft-tissue contrast and multiplanar capabilities, has shown promise in depicting articular cartilage. Cartilage is best depicted when an "arthrogram effect" is present, achieved with T2-weighted spin-echo imaging, with some gradient-echo pulse sequences, and when intraarticular contrast material is used. If performed with such techniques, MR imaging is the method of choice for evaluating specific cartilage loss, osteochondritis dissecans, and other osteochondral abnormalities.

Arthrography↗
PubMed1992

Misleading aggressive MR imaging appearance of some benign musculoskeletal lesions.

After plain radiography has been performed, magnetic resonance (MR) imaging is considered the modality of choice for the evaluation of suspected musculoskeletal lesions because of its exquisite sensitivity to changes in the signal intensity of marrow and soft tissue. That sensitivity, however, may lead to an overestimation of the aggressiveness and extent of some benign bone lesions, particularly in children. Such lesions include chondroblastoma, osteoid osteoma, eosinophilic granuloma, and stress fractures. Potentially misleading MR features commonly seen include prominent marrow edema, soft-tissue edema, and apparent mass effect adjacent to the bone lesion. Features that these lesions have in common that may explain the MR findings include associated inflammatory reactions caused by the lesions and their occurrence in childhood, when the periosteum is more loosely attached. Knowledge of the potential pitfalls encountered with MR imaging may help explain the discrepancy between the radiographic and MR appearances of these benign lesions and avoid misplaced reliance on MR imaging for a diagnosis. Radiography remains the single most valuable modality in determining a differential diagnosis for bone lesions.

Adolescent↗
PubMed1991

Seat belt injuries: radiologic findings and clinical correlation.

The seat belt syndrome consists of skeletal, soft-tissue, and visceral injuries associated with use of two- and three-point restraints in patients involved in motor vehicle accidents. Skin abrasions of the neck, chest, and abdomen--the classic seat belt sign--indicate internal injury in 30% of cases. Neck abrasions are associated with injuries to the carotid artery, larynx, and cervical spine; chest abrasions, with fractures of the sternum, ribs, and clavicles and injuries to the heart and thoracic aorta; and abdominal abrasions, with mesenteric tears, bowel perforation and hematoma, Chance fractures, and injuries to the abdominal aorta. The seat belt sign should prompt a diligent search for related injuries.

Abdominal Injuries↗
PubMed1991

Cross-sectional imaging of the patellofemoral joint and surrounding structures.

Computed tomography (CT) and magnetic resonance (MR) imaging are extremely useful in the accurate diagnosis of anterior knee pain, a common complaint arising from numerous causes (including fracture, chondromalacia patellae, and alignment and tracking abnormalities). Plain CT is effective for evaluating intraosseous lesions of the knee. Although CT arthrography provides excellent visualization of the patellar articular cartilage, the technique is expensive and invasive. Cine CT is an excellent method for assessing patellofemoral tracking and alignment. Kinematic MR imaging can also perform this function. In addition, MR imaging can provide valuable information concerning the status of patellar cartilage. Although MR imaging can accurately show high-grade chondromalacia patellae, it is less accurate in the detection of low-grade disease. The authors believe that MR imaging and plain radiography offer radiologists the greatest latitude in making a specific diagnosis of the cause of anterior knee pain; however, CT is a useful alternative.

Arthrography↗
PubMed1991

Mammographic follow-up of nonpalpable low-suspicion breast abnormalities: one versus two views.

A retrospective study involving 498 women with a total of 666 breast lesions was undertaken to determine the relative efficacy of one- and two-view mammography in the follow-up evaluation of "low-suspicion" abnormal mammographic findings. These abnormalities consisted of well-defined masses (47.1%), well-defined punctate microcalcifications (20.9%), and parenchymal asymmetry (32.0%). Confidence in the adequacy of the single-view follow-up was high in 91% of cases. The addition of the second mammographic view changed the one-view interpretation in approximately 1% of all cases. Two cancers were detected during the initial follow-up period. Both cancers were detected with single-view and standard two-view follow-up examinations, with high confidence. In this controlled retrospective study, the single-view follow-up examination was adequate for follow-up of most low-suspicion mammographic abnormalities. Monitoring by physicians, however, would be necessary to prevent an unacceptable number of patient recalls, which could make the one-view follow-up study impractical to use in some practices.

Adult↗
PubMed1991

Temporomandibular joint after meniscoplasty: appearance at MR imaging.

Twenty-five temporomandibular joints (TMJs) were studied in 20 patients who had undergone meniscoplasty. In all patients, preoperative magnetic resonance (MR) images showed anteriorly dislocated disks; all patients underwent a similar postoperative MR examination an average of 6 months after surgery. The results of these studies were correlated with clinical results of surgery, which were classified as poor, fair, good, or excellent at follow-up MR imaging. In 10 TMJs (eight patients [40%]) the clinical results were excellent or good; in 15 TMJs (12 patients [60%]), fair or poor. The position of the disk relative to its preoperative position was a good discriminator in determination of the clinical success of meniscoplasty. After surgery, in all patients with good or excellent results, the disks appeared to be in a normal or an improved position compared with that prior to surgery; in those with poor or fair results, the TMJs had anteriorly dislocated disks that showed no improvement.

Adolescent↗
PubMed1991

Occult breast masses: use of a mammographic localizing grid for US evaluation.

To determine if there was a problem of misidentification of mammographically detected masses with freehand ultrasound (US), the authors examined 50 mammographically distinct masses in 47 patients who were scheduled to undergo needle localization. In only six cases were the masses to be localized in an area of the breast that contained other mammographic opacities that could have led to problems of identification. The patients were first studied with freehand US. Results were then compared with those subsequently obtained with a fenestrated mammographic compression grid to guide the US evaluation. Needle localization was then performed. In five of 50 cases, masses detected with freehand US and initially believed to correspond to the mammographically detected mass were subsequently found to represent different areas of the breast when US was used with the compression grid. These results suggest that the potential for misidentification of masses with freehand US is real and that a mammographic grid localization device can be used to overcome this problem.

Breast Neoplasms↗
PubMed1991

Indications for radiography in patients with acute ankle injuries: role of the physical examination.

A prospective study was performed to test the hypothesis that a thorough physical examination can eliminate the need for a large number of radiographs obtained in patients with acute ankle trauma. Two hundred one patients were seen in the emergency department for acute ankle trauma and referred to the department of radiology for ankle radiographs. Radiology residents performed a brief but thorough physical examination of the ankle in all 201 patients. Solely on the basis of a strict set of physical examination criteria (examination for gross deformity, instability, crepitation, focal bony tenderness, severe soft-tissue tenderness, moderate or severe soft-tissue swelling, and ecchymosis), the radiologists determined whether or not the radiographs were indicated. All patients, irrespective of the physical examination, underwent ankle radiography, and the results were correlated with those of the physical examination. On the basis of the results of the physical examinations, 101 (50%) of the radiologic studies were not indicated. In only one of these patients was a fracture seen on radiographs. The radiograph in this case showed a small avulsion fracture of the dorsal aspect of the talus that was clinically insignificant (no cast or surgery was required). Our results suggest that a brief but thorough physical examination can eliminate the need for a large percentage of radiographs ordered in patients with acute ankle trauma.

Adolescent↗
PubMed1991

Hyperparathyroidism.

Since the introduction of routine automated measurements of serum calcium levels in the 1970s, the detection of primary hyperparathyroidism has risen considerably. Nevertheless, the severe bone changes described by von Recklinghausen are still quite rare. The apparent rise in incidence is accounted for by the discovery of a large group of predominantly asymptomatic elderly patients who have mild primary hyperparathyroidism. Because the diagnosis is most often confirmed through laboratory tests, radiologic studies are now most useful in assessing the severity of the disease. The presence of bone changes is an accepted indication for parathyroid surgery in primary hyperparathyroidism. For patients with asymptomatic disease in whom nonsurgical treatment may be considered, radiographic evaluation is one of several techniques that may be used to assess progression. High resolution radiographs of the hands are most valuable in this regard. Accelerated bone mineral loss, as measured by quantitative techniques, will probably play a significant role in the future. Radiographic follow-up of patients with renal disease and secondary hyperparathyroidism is equally important, as increased bone or soft tissue changes may indicate a need for therapeutic change. Radiographically identifiable changes of hyperparathyroidism consist mainly of various types of accelerated bone resorption. Multifocal subperiosteal resorption is generally considered to be pathognomonic of hyperparathyroidism. Subligamentous, subchondral, endosteal, and intracortical resorption are also important manifestations of accelerated bone turnover. The earliest bone changes are visible in the hands and should be searched for especially carefully in the phalanges and terminal tufts. Only occasionally will changes be found elsewhere in the skeleton when hand changes are not present.

Aged↗
PubMed1990

Calcium hydroxyapatite deposition disease.

Calcium hydroxyapatite crystal deposition disease is characterized by the presence of basic calcium phosphate crystals--predominantly hydroxyapatite--in the periarticular soft tissues, especially the tendons. The entity is best recognized as "calcific tendinitis" at its most frequent site about the shoulder, but the disease involves numerous other sites and may be more appropriately termed calcific periarthritis. This article illustrates typical and atypical radiographic features of hydroxyapatite deposition, as well as some unusual manifestations of the disease. A brief review of various theories on the pathogenesis of the disease and a section on differential diagnosis is included.

Arthrography↗
PubMed1990

Patellar cartilage lesions: in vitro detection and staging with MR imaging and pathologic correlation.

Fourteen freshly disarticulated knee specimens were studied to assess the usefulness of magnetic resonance (MR) imaging in the detection and correct staging of patellar chondral lesions. Axial and sagittal images were obtained; T1-weighted spin-echo sequences were found satisfactory for defining cartilage morphology. Specimens were sectioned and examined grossly for cartilage changes such as softening, blistering, fibrillation, fissuring, and frank subchondral bone exposure. In a side-by-side comparison, all lesions classified grossly in the Shahriaree system as stage II or higher showed MR changes. Stage I changes could not be identified in disarticulated specimens. Stage III lesions showed cartilage irregularity (ulceration) or a loss of the normal, sharply defined margin between coapted cartilage, which represented "crabmeat" fibrillation. Stage IV lesions showed ulceration to bone, sometimes with subchondral bone changes. In this in vitro, preliminary study, MR imaging was found to be an accurate means for detecting and staging moderate and advanced patellar cartilage lesions.

Adult↗
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↗