Biomedical subjects

D L Renfrew

Publications and source records attributed to D L Renfrew.

14 recordsLinked to original sources

PubMed1992

The use of intravenous gadopentetate dimeglumine in magnetic resonance imaging of synovial lesions.

Spin echo T1- and T2-weighted images and intravenously administered gadopentetate dimeglumine-enhanced T1-weighted images were obtained in 4 normal volunteers and 11 patients (11 joints) with painful, intermittent, or persistent joint swelling of unknown etiology. These studies were retrospectively reviewed to assess the benefits of contrast-enhanced magnetic resonance imaging (MRI) in evaluating the synovium. Normal synovium and joint fluid showed no visually apparent enhancement on images obtained immediately after intravenous injection of gadopentetate dimeglumine. Abnormal synovium enhanced significantly, allowing the precise identification of equivocal or unsuspected synovial disease processes. These results suggest that, in selected cases, enhanced MRI can be a useful adjunct in the evaluation of suspected synovial disease processes.

Adult↗

PubMed1992

Error in radiology: classification and lessons in 182 cases presented at a problem case conference.

The authors review and classify errors in 182 cases that were presented at problem case conferences between August 1986 and October 1990. Errors were classified by means of a system developed 20 years ago and by means of a system developed within the past several years. The authors found that sources of error have changed very little. Errors usually involved failure to consult old radiologic studies or reports, limitations in imaging technique, acquisition of inaccurate or incomplete clinical history, location of a lesion outside the area of interest on an image, lack of knowledge, failure to continue to search for abnormalities after the first abnormality was found, and failure to recognize a normal biologic variant. Errors included 126 perceptual errors (64 false-negative, 15 false-positive, and 47 misclassification errors) and 56 mishaps, including 38 complications and 18 communication errors. In seven cases nonperception errors occurred because established departmental routines were not followed, and in nine cases a new departmental routine was established after a complication occurred. Departmental policy exerts less effect on perception and interpretation errors.

Diagnostic Errors↗

PubMed1992

Hypercard coding system for the ACR Index for Radiological Diagnoses.

We describe a computer version of the Index for Radiological Diagnoses of the American College of Radiology (ACR). This system combines a graphics interface with a search mechanism while preserving the hierarchical structure of the Index. The graphics interface allows easy selection of an anatomic part, while the search mechanism provides the code numbers associated with an entered term. The computer system and the paperback version of the ACR Index were compared by having 52 volunteers (21 radiology faculty members, 21 radiology residents, and 10 medical students) each code 30 cases with the book and a matched set of 30 cases with the computer. The average time to code cases was shorter when the computer was used (52.2 vs 64.5 sec; p less than .0001). Accuracy was higher when the computer was used (96.4% vs 90.4%; p less than .0001). The average confidence in the computer diagnosis was also higher (9.73 vs 9.51, on a scale of 1-10; p = .0016). This system demonstrates the ability of a computer program to outperform an analogous noncomputerized system.

Disease↗

PubMed1992

Percutaneous needle biopsy of musculoskeletal lesions. 1. Effective accuracy and diagnostic utility.

The utility of a diagnostic test depends not only on its accuracy but also on how its results affect clinical management. We reviewed the results of 102 percutaneous needle biopsies to determine the accuracy, effective accuracy, and diagnostic utility of the procedure. We found percutaneous needle biopsy was similarly accurate in identifying suspected metastatic lesions (82%, n = 44), suspected musculoskeletal infections (90%, n = 29), and suspected primary musculoskeletal tumors (83%, n = 29). Effective accuracy, or accuracy discounted for results with limited clinical utility, was highest in identifying suspected metastatic deposits (77%), slightly lower in suspected infections (72%), and lowest in suspected primary tumors (59%). Diagnostic utility (the probability-weighted sum of the utility values of all possible outcomes of a diagnostic test) for identifying metastatic deposits and infections exceeded that for suspected primary tumors. Percutaneous needle biopsy in patients with suspected primary tumors must be performed with the knowledge that, even though technically accurate, such biopsies may be of limited clinical value. Percutaneous needle biopsy of suspected metastatic lesions and suspected infections, on the other hand, offers high accuracy and high diagnostic utility.

Adolescent↗

PubMed1992

Percutaneous needle biopsy of musculoskeletal lesions. 2. Cost-effectiveness.

We compared the cost-effectiveness of fluoroscopically directed percutaneous needle biopsy (PNB) of musculoskeletal lesions, CT-guided PNB, and open biopsy. We independently assessed the following characteristics: suspected lesion type (metastatic deposit, infection, or primary neoplasm, as determined by clinical findings and radiologic appearance before biopsy); lesion location (axial or appendicular); and appearance on plain films (radiolucent or lytic, sclerotic, vertebral compression fracture, and soft-tissue lesions). In suspected primary tumors, cost-effectiveness of PNB was similar to that of open biopsy: fluoroscopically directed PNB was slightly more cost-effective than open biopsy whereas CT-directed PNB was slightly less cost-effective. Either type of PNB was cost-effective for suspected metastatic deposits and infections, axial and appendicular lesions, radiolucent or lytic lesions, and soft-tissue lesions. We conclude that PNB is cost-effective for most musculoskeletal lesions.

Biopsy↗

PubMed1991

Pisiform fractures.

Fractures of the pisiform are often missed due to improper radiographic evaluation and a tendency to focus on other, more obvious injuries. Delayed diagnosis may result in disabling sequelae. A high index of clinical suspicion and appropriate radiographic examination will establish the correct diagnosis. Ten patients with pisiform fracture are presented. The anatomy, mechanism of injury, clinical presentation, radiographic features, and evaluation of this injury are discussed.

Adult↗

PubMed1991

Magnetic resonance imaging of myxoid containing tumors.

Myxoid tissue forms part of many benign and malignant soft-tissue tumors. The advent of percutaneous needle biopsy has made it important to be aware of the diagnostic implications of biopsy samples containing myxoid tissue. To determine whether the magnetic resonance imaging (MRI) characteristics could help establish the diagnosis, we compared the MR images of 11 tumors containing myxoid tissue with the resected tumor tissue. In our small series of these rare tumors, the MRI characteristics allowed differentiation of intramuscular myxomas from malignant neoplasms containing myxoid tissue. Intramuscular myxomas meet the following conditions: (a) they are well circumscribed; (b) they arise within muscle; (c) T1-weighted images demonstrate uniform, decreased signal intensity; (d) T2-weighted images demonstrate uniform increased signal intensity; (e) contrast-enhanced images exhibit an inhomogeneous increase in signal intensity. If any of these conditions is not met, then a malignancy containing myxoid tissue should be suspected.

Adult↗

PubMed1991

Curriculum for musculoskeletal radiology.

Although general suggestions have been made regarding a radiology residency curriculum, no specific list of entities has been offered. Over the past ten years, we have developed a resident-run morning conference in musculoskeletal radiology that is supervised by faculty and covers a specific curriculum. We offer our curriculum as an example that may assist other departments in developing their own curricula.

Curriculum↗

PubMed1991

Glenoid labrum: evaluation with MR imaging.

Fifteen patients with shoulder instability and nine asymptomatic volunteers were studied with magnetic resonance (MR) imaging. The shoulder joint was visualized by means of arthroscopy or surgery in all patients. Ten patients had abnormalities of the glenoid labrum. Two musculoskeletal radiologists interpreted the MR images of the patients and volunteers without knowledge of the clinical history or surgical results. The surgical and arthroscopic results were used as the standard of reference in symptomatic patients. Observer A achieved a sensitivity of 44.4% and a specificity of 66.7%; observer B had a sensitivity of 77.8% and a specificity of 66.7%. In addition to the poor sensitivities and specificities, there was substantial intra- and interobserver variability. Assuming that the shoulders of the asymptomatic volunteers were normal, the specificities were 100.0% and 88.9% for observers A and B respectively. In this small study, axial MR imaging was relatively insensitive and nonspecific in the evaluation of labral lesions. Further study will be necessary to determine the utility and limits of MR imaging in this regard.

Adolescent↗

PubMed1991

CT-guided percutaneous transpedicular biopsy of the spine.

Occasionally, vertebral body lesions are encountered that are ill suited to the standard posterolateral approach to biopsy. The authors used a transpedicular approach to spine biopsy in six such cases. The authors suggest that this approach be used when the location of the lesion does not allow easy access by means of the posterolateral approach.

Aged↗

PubMed1991

Percutaneous procedures for the diagnosis and treatment of lower back pain: diskography, facet-joint injection, and epidural injection.

This review discusses the indications, techniques, complications, and results of three percutaneous procedures used to evaluate and treat lower back pain: diskography, facet-joint injection, and epidural injection. Diskography, performed by injection of contrast medium into the nucleus pulposus, is a technique used to determine the cause of lower back pain in patients in whom findings on other imaging studies are normal or conflicting. Injection of steroids and anesthetic into the facet joints of the lumbar spine is useful to diagnose or treat patients with facet syndrome (back pain caused by abnormalities of the facet joints). Injection of steroids and anesthetic agents into the epidural space provides short-term relief, and can sometimes provide permanent relief, of lower back pain.

Anesthesia, Spinal↗

PubMed1990

HyperCard-assisted journal article filing system.

The author describes his own system of filling and accessing articles by means of a computerized representation of the articles. This system, using HyperCard stacks, provides an easy and quick method to store and retrieve useful articles.

Databases, Factual↗

PubMed1986

Per anal balloon dilatation of a post-necrotizing enterocolitis stricture of the sigmoid colon.

Per anal balloon dilatation of a sigmoid colon stricture caused by necrotizing enterocolitis allowed identification of a more proximal lesion which would otherwise have gone radiographically undetected. Repeated dilatations at two weeks and four weeks following the initial dilatation of the stricture resulted in relief of the stricture and obviated the need for surgical treatment of this lesion.

Angioplasty, Balloon↗

PubMedDate not supplied

Correct placement of epidural steroid injections: fluoroscopic guidance and contrast administration.

We prospectively evaluated 316 caudal-approach epidural steroid injections given by staff radiologists and residents in our department over a 1-year period. Needle placement was checked with fluoroscopy and corrected if necessary. When the needle tip was within the sacral canal, nonionic contrast material was injected. If epidural contrast was not observed, the needle tip was repositioned. Of 111 procedures performed by physicians who had given fewer than 10 epidural steroid injections, 53 (47.7%) resulted in correct nonfluoroscopically directed placement of the needle. For physicians who had performed between 10 and 50 such procedures, 62 (53.4%) of 116 had correct nonfluoroscopically directed placement. For staff physicians, 55 (61.7%) of 89 placements were correct. Even when the sacral hiatus was easily palpated and a staff physician was confident that he or she was within the epidural space, fluoroscopy revealed incorrect placement 14.2% of the time (seven of 49 procedures). In addition, when the needle was positioned within the sacral canal and no blood was evident on Valsalva maneuver or aspiration, the injection was venous in 29 of 316 procedures (9.2%). The presence of blood on the needle stylus was not a reliable indicator of venous placement of the needle. Our findings indicate that fluoroscopy is essential for correct placement of epidural steroid injection. Contrast administration is necessary to avoid venous injection of steroids.

Adult↗