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Biomedical subjects

E A Brandser

Publications and source records attributed to E A Brandser.

At least 19 recordsLinked to original sources
PubMed2001

Gaze dwell times on acute trauma injuries missed because of satisfaction of search.

RATIONALE AND OBJECTIVES: The authors performed this study to determine whether satisfaction of search (SOS) errors in patients with multiple traumas are caused by faulty visual scanning, faulty recognition, or faulty decision making. MATERIALS AND METHODS: A series of radiographs were obtained in patients with multiple traumas. Radiologists interpreted each series under two experimental conditions: when the first radiograph in the series included a fracture, and when it did not. In the first experiment, the initial radiographs showed nondisplaced fractures of the extremities (minor fractures); in the second experiment, the initial radiographs showed abnormalities of greater clinical importance (major fractures). Each series also included a radiograph with a subtle (test) fracture and a normal radiograph on which detection accuracy was measured. In each experiment, gaze dwell time was recorded as 10 radiologists reviewed images from 10 simulated cases of multiple trauma. RESULTS: An SOS effect could be demonstrated only in the second experiment. Analysis of dwell times showed that search on subsequent radiographs was shortened when the initial radiograph contained a fracture; however, the errors were not based on faulty scanning. CONCLUSION: The SOS effect in musculoskeletal trauma is not caused by faulty scanning. Demonstration of an SOS effect on test fractures with major but not minor additional fractures suggests that detection of other fractures is inversely related to the severity of the detected fracture.

Fractures, Bone↗
PubMed2001

Effect of knowledge of chronologic age on the variability of pediatric bone age determined using the Greulich and Pyle standards.

OBJECTIVE: The purpose of this study was to investigate the impact of knowing chronologic age on the variability of pediatric bone age determination using the method of Greulich and Pyle. MATERIALS AND METHODS: Radiographs of the left hand of 107 patients were interpreted by four radiologists on two separate occasions, once with and once without knowledge of the patient's chronologic age at time of interpretation. Twenty-five radiographs were randomly selected and reevaluated twice by each radiologist. Interobserver and intraobserver variability were calculated and compared for the two conditions. The distribution of studies with normal and abnormal findings was then compared across knowledge conditions for all observers and by individual observer, using two standard deviations above and below chronologic age as the range of "normal". RESULTS: When the chronologic age was known, the interobserver reliability coefficient for knowledge of chronologic age was 0.954 and when not known, 0.952. The intraobserver reliability coefficients when chronologic age was known ranged from 0.944 to 0.967, and when not known from 0.938 to 0.980. Observers interpreted 58% (248/428) of the radiographs as having normal findings when chronologic age was known and 48% (205/428) when chronologic age was not known. CONCLUSION: Knowing chronologic age before assessing bone age radiographs does not affect the reproducibility of assessment. However, observers are more likely to interpret the radiograph as showing normal findings when chronologic age is known than if the interpretation is performed with the observer unaware of chronologic age.

Adolescent↗
PubMed2000

A contaminated binormal model for ROC data: Part I. Some interesting examples of binormal degeneracy.

RATIONALE AND OBJECTIVES: Receiver operating characteristic (ROC) data with false-positive fractions of 0 are often difficult to fit with standard ROC methods and are sometimes discarded. Some extreme examples of such data were analyzed to evaluate the nature of these difficulties. MATERIALS AND METHODS: Rating reports of fracture for single-view ankle radiographs were analyzed with the binormal ROC model and with two ROC models that keep the ROC curve from crossing the chance line. Because fractures were almost never reported that were not present, some views and locations yielded only ROC points with false-positive fractions of 0, while others yielded at least one ROC point with a non-0 false-positive fraction. RESULTS: The models tended to yield ROC areas close to or equal to 1. ROC areas of 1 imply a true-positive fraction close to 1; yet the data contained no such fractions. When all false-positive fractions were 0, the true-positive fraction could be much higher for one view than another for all observers. ROC areas gave little or no hint of these unmistakable differences in performance. CONCLUSION: These data challenge the validity and robustness of current ROC models. A key aspect of ankle fractures is that some may be visible on one view but not at all visible on another.

Ankle Injuries↗
PubMed2000

Clinical failure after posterior wall acetabular fractures: the influence of initial fracture patterns.

OBJECTIVE: To determine radiographic and clinical features that predict rapid failure after open reduction and internal fixation of posterior wall acetabular fractures. DESIGN: Retrospective radiographic review and patient follow-up study. SETTING: University hospital. PATIENTS: Forty-two patients with posterior wall acetabular fractures. INTERVENTION: Open reduction and internal fixation. MAIN OUTCOME MEASURES: Radiographs, Merle D'Aubigné scores, Musculoskeletal Functional Assessment. RESULTS: Eleven patients had complete loss of joint space by one year postinjury; eight of these individuals required reconstructive surgery. These patients more commonly had fractures with comminution of three fragments or more (p = 0.001) or fracture into the subchondral arc at the level of the acetabular roof (p = 0.045). CONCLUSION: Poor outcomes after open reduction and internal fixation are associated with certain types of posterior wall fracture patterns.

Acetabulum↗
PubMed2000

Contribution of individual projections alone and in combination for radiographic detection of ankle fractures.

OBJECTIVE: We wanted to determine whether the standard three-view ankle radiographic series could be replaced by a two-view combination, and if so, which two-view combination (anteroposterior with lateral or mortise with lateral) would be superior. MATERIALS AND METHODS: During a 12-month period, we retrospectively reviewed 556 consecutive ankle radiographic studies consisting of anteroposterior, mortise, and lateral views. One hundred twenty patients with at least one ankle fracture were paired with 140 healthy control subjects. Each image in the three-view examination was separated and sorted by view and studied independently; all images were reviewed by two skeletal radiologists and two orthopedic surgeons. Each radiograph was evaluated for fracture of the medial, lateral, and posterior malleoli and the foot using a five-point confidence rating. Performance of each view and modeled two- and three-view combinations of views was evaluated with modified receiver operating characteristic analysis. RESULTS: The data provide little support for preferring either two-view combination (anteroposterior-lateral or mortise-lateral) for any type of fracture. The three-view combination does detect significantly more fractures than some two-view combinations in some locations, and there is a statistically significant cost in diagnostic accuracy for eliminating the anteroposterior or mortise view. CONCLUSION: Reducing the ankle radiographic series from three to two views would result in a small but significant decrease in the detection of fractures of the ankle and foot. Both two-view combinations are equivalent for fracture detection.

Adolescent↗
PubMed2000

High density polyetherurethane foam as a fragmentation and radiographic surrogate for cortical bone.

BACKGROUND: Although one of the most important factors in predicting outcome of articular fracture, the comminution of the fracture is only subjectively assessed. To facilitate development of objective, quantitative measures of comminution phenomena, there is need for a bone fragmentation surrogate. METHODS: Laboratory investigation was undertaken to develop and characterize a novel synthetic material capable of emulating the fragmentation and radiographic behavior of human cortical bone. RESULT: Screening tests performed with a drop tower apparatus identified high-density polyetherurethane foam as having suitable fragmentation properties. The material's impact behavior and its quasi-static mechanical properties are here described. Dispersal of barium sulfate (BaSO4) in the resin achieved radio-density closely resembling that of bone, without detectably altering mechanical behavior. The surrogate material's ultimate strength, elastic modulus, and quasi-static toughness are within an order of magnitude of those of mammalian cortical bone. The spectrum of comminution patterns produced by this material when impacted with varying amounts of energy is very comparable to the spectrum of bone fragment comminution seen clinically. CONCLUSIONS: A novel high-density polyetherurethane foam, when subjected to impact loading, sustains comminuted fracture in a manner strikingly similar to cortical bone. Moreover, since the material also can be doped with radio-opacifier so as to closely emulate bone's radiographic signature, it opens many new possibilities for CT-based systematic study of comminution phenomena.

Barium Sulfate↗
PubMed1998

Elastofibroma dorsi: prevalence in an elderly patient population as revealed by CT.

OBJECTIVE: We wanted to determine the prevalence and appearance of elastofibroma dorsi in an elderly patient population (n = 258) who underwent CT of the chest for reasons other than to evaluate posterolateral chest wall pain, stiffness, or a mass. CONCLUSION: Five elastofibromas were detected in four patients; none of these elastofibromas were noted at initial examination. Our study suggests that the prevalence of elastofibroma dorsi revealed by CT is 2%, which is lower than the 11-24% found in autopsy series but higher than expected for such a rare tumor. Elastofibroma dorsi typically has a layered appearance on CT; however, in our study, homogeneous soft-tissue attenuation was noted. The diagnosis is often missed prospectively. Familiarity with the location and imaging appearance of elastofibroma dorsi may enhance detection and characterization of posterolateral chest wall masses in elderly patients.

Aged↗
PubMed1998

Non-traumatic lesser trochanter avulsion: a report of three cases.

Avulsion fractures of the lesser trochanter in adults are almost always due to metastatic bone disease. Familiarity with this characteristic association can lead to early diagnosis and assist the orthopaedist in implementing effective management. We report three patients with avulsion of the lesser trochanter due to neoplasm. In one patient, this was the first sign of metastatic disease; in another patient, there was no history of a primary neoplasm and the avulsion was the first evidence of disease.

Adenocarcinoma↗
PubMed1997

Assessment of the AO/ASIF fracture classification for the distal tibia.

OBJECTIVES: The purpose of this study was to assess the interobserver reliability and intraobserver reproducibility of the AO/ASIF and Rüedi and Allgöwer classifications for fractures of the distal tibia, and to determine the benefit of a computed tomography (CT) scan and experience on observer agreement for several fracture characteristics, including classification. METHODS: The radiographs of forty-three fractures of the distal tibia, fourteen of which had CT scans, were assessed by groups of experienced and less-experienced observers. Each case was classified according to the AO/ASIF and Rüedi and Allgöwer systems. Several other fracture characteristics also were assessed. The kappa coefficient of agreement was calculated and used to compare the interobserver reliability and intraobserver reproducibility of the classification systems and to determine the benefit of experience and CT scans. The intraclass correlation coefficient was used to assess noncategoric data. RESULTS: Interobserver and intraobserver agreements were good when classifying fractures into AO/ASIF types and significantly better than that for the Rüedi and Allgöwer system. However, agreement was poor when classifying the fractures into AO/ASIF groups. For most assessments, the experienced group tended to have higher levels of interobserver agreement, but not intraobserver agreement. Viewing the CT scans improved agreement on the percentage of articular surface involved, but it did not improve interobserver reliability or intraobserver reproducibility for either of the classification systems. CONCLUSION: The AO/ASIF classification for fractures of the distal tibia has good observer agreement at the type level, but poor agreement at the group level. Experience tends to improve interobserver agreement, but not intraobserver agreement. Viewing CT scans does not improve agreement on classification, but it tends to improve agreement on articular surface involvement.

Ankle Injuries↗
PubMed1997

Modified technique for fluid aspiration from the hip in patients with prosthetic hips.

A modified technique was used for diagnostic aspiration of fluid from the hip in 185 patients who had previously undergone total hip arthroplasty. The aspiration needle was advanced past the lateral aspect of the shaft of the prosthesis and into the dependent portion of the joint. Fluid was successfully aspirated in 181 of 185 patients; thus the dry-tap rate was 2.2% (four of 185 patients). The modified technique was simple, could be performed quickly, and was effective for sampling joint fluid in patients with hip prostheses.

Biopsy, Needle↗
PubMed1997

Pediatric radiology at a rural hospital: value of teleradiology and subspecialty consultation.

OBJECTIVE: We performed a field study and subsequent laboratory investigation of pediatric radiology at a small rural hospital. Our investigation had three components: to describe the characteristics of pediatric radiology in a rural primary care facility, to test the diagnostic accuracy of interpretation of pediatric images transmitted by teleradiology, and to compare relative diagnostic accuracy of general and pediatric radiologists who interpreted pediatric images at a rural institution. MATERIALS AND METHODS: All 196 pediatric radiographs obtained during a 4-month period comprised the database from which we determined practice characteristics. Reports of 153 unselected cases interpreted by general radiologists using teleradiology were compared with interpretation of the same cases by a pediatric radiologist who interpreted the original radiographs. Discrepant cases were further investigated by a receiver-operating-characteristic curve experiment in which general and pediatric radiologists interpreted each case twice: once viewing teleradiologic images and once viewing the original radiographs at another setting. We then compared interpretive accuracy of observers and techniques. RESULTS: The pediatric radiographs were predominantly simple examinations for common acute disease, particularly pneumonia and fractures. Discrepancies of interpretation between teleradiology and original radiographs, which occurred in 13% of images, showed no significant difference in accuracy of interpretation for either teleradiologic images or original radiographs. Likewise, we found no significant advantage for accuracy of interpretation by general or pediatric radiologists. Receiver-operating-characteristic analysis of 18 discrepant cases showed slightly increased accuracy for interpretation of original radiographs by pediatric subspecialists. CONCLUSION: Simple pediatric radiographs obtained at a rural primary care institution and transmitted by teleradiology can be adequately interpreted by general radiologists.

Adolescent↗
PubMed1997

Metastatic disease of the skeleton.

Metastatic cancer is among the most frequent causes of skeletal pain associated with a destructive bone lesion or pathologic fracture in adults. Patients with a known primary carcinoma should undergo systematic evaluation and monitoring to determine the extent of skeletal disease and risk of pathologic fracture. Patients without a known primary carcinoma who have symptoms consistent with metastatic disease of the skeleton present a diagnostic dilemma. Plain radiographs may not reveal a metastatic lesion until extensive marrow replacement has occurred. Bone scans are more sensitive than radiographs and provide a survey of the entire skeleton. However, increased uptake on a bone scan is not specific and some neoplasms are poorly detected by scintigraphy. Computed tomography can identify bone destruction or neoplastic bone formation that is not easily demonstrated by plain radiographs and can help the clinician assess the risk of pathologic fracture. Magnetic resonance imaging may be helpful in detecting and defining the extent and precise location of marrow lesions and soft tissue extension of neoplasms.

Bone Neoplasms↗
PubMed1997

Thoracic and lumbar spine trauma.

The thoracic and lumbar regions of the spine have unique anatomic and biomechanical features that result in different characteristic patterns of injury. This article reviews common injuries to the thoracic and lumbar spine and emphasizes the relationship between anatomic features and characteristic patterns of injury. An approach to imaging of the trauma patient is presented, focusing on detection and classification of spinal injuries.

Biomechanical Phenomena↗
PubMed1997

Pelvic and acetabular trauma.

Blunt pelvic trauma may lead to disruption of the pelvic ring, acetabular fracture, and significant soft tissue injury. The radiologist must be familiar with not only the imaging approach to these lesions but also the anatomy, biomechanics of injury, and fracture classification to communicate effectively with trauma surgeons and to participate as a member of the trauma team.

Acetabulum↗
PubMed1997

Role of MR imaging in acute injuries to the appendicular skeleton.

Clinical applications of MR imaging in the setting of acute extremity injuries are discussed in general and by anatomic regions. General indications include physeal injuries, occult fractures, stress fractures, musculotendinous injuries, and ligamentous injuries. Indications of MR imaging in the acute injury setting have been expanding. MR imaging is often used to triage patients definitively to surgical versus conservative treatment for such conditions as suspected hip fracture. High-performance athletes are also often imaged acutely. Radiologists need to be familiar with the possible applications of MR imaging to acute extremity injuries, and discuss with referring physicians what indications are appropriate locally. In this way, the role of MR imaging in this area will be further defined in the future.

Acute Disease↗
PubMed1997

Stress and insufficiency fractures.

Stress fractures of the axial and appendicular skeleton typically present as localized pain that develops without a history of specific acute injury. The differential diagnosis includes primary or metastatic neoplasms, infections, musculoskeletal soft tissue injuries, nerve compression syndromes and joint diseases. Plain radiographs may demonstrate changes consistent with fracture, including a fracture line or fracture callus. In many cases, however, initial radiographs are normal or nondiagnostic. This occurs most frequently in three situations: (1) when radiographs are obtained soon after the onset of symptoms, before the appearance of a fracture line or new bone formation; (2) in patients with osteopenia, in whom detection of a fracture line and new bone formation is difficult, and (3) when the fracture involves areas of the skeleton that are difficult to study with plain films (including the spine and pelvis). When the plain films are normal, other tests such as bone scans, computed tomography or magnetic resonance imaging usually demonstrate the fracture.

Diagnosis, Differential↗
PubMed1996

Imaging of muscle injuries.

Although skeletal muscle is the single largest tissue in the body, there is little written about it in the radiologic literature. Indirect muscle injuries, also called strains or tears, are common in athletics, and knowing the morphology and physiology of the muscle-tendon unit is the key to the understanding of these injuries. Eccentric muscle activation produces more tension within the muscle than when it is activated concentrically, making it more susceptible to tearing. Injuries involving the muscle belly tend to occur near the myotendinous junction. In adolescents, the weakest link in the muscle-tendon-bone complex is the apophysis. Traditionally, plain radiography has been the main diagnostic modality for evaluation of these injuries; however, with the advent of MRI it has become much easier to diagnose injuries primarily affecting the soft tissues. This article reviews the anatomy and physiology of the muscle-tendon unit as they relate to indirect muscle injuries. Examples of common muscle injuries are illustrated.

Adolescent↗