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PubMed1998

Towards a partnership in care: nurses' and doctors' interpretation of extremity trauma radiology.

Receiver operating characteristic (ROC) is a method of assessing the sensitivity and specificity of a classification at a variety of thresholds. It allows a quantitative comparison of several classifiers. It was used in this study to compare doctors and nurses with respect to their ability to diagnose X-rays. X-ray interpretations were measured using a confidence rating scale, on 50 radiographs from a generated library of extremity X-rays following trauma. The catalogue of radiographs were selected from real cases of extremity trauma which were considered representative of typical accident and emergency case scenarios. The interpretations of doctors and nurse practitioners were compared with the gold standard of the consultant radiologist. No significant differences were seen between the two groups. This study is based on work done for a master's thesis by one of the authors (Overton) supervised by the other author.

Arm Injuries↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMed2003

Electron density characterization by use of a broadband x-ray-compatible wave-front sensor.

The use of a Hartmann wave-front sensor to accurately measure the line-integrated electron density gradients formed in laser-produced and z-pinch plasma experiments is examined. This wave-front sensor may be used with a soft-x-ray laser as well as with incoherent line emission at multikilovolt x-ray energies. This diagnostic is significantly easier to use than interferometery and moiré deflectometry, both of which have been demonstrated with soft-x-ray lasers. This scheme is experimentally demonstrated in the visible region by use of a Shack-Hartmann wave-front sensor and a liquid-crystal spatial light modulator to simulate a phase profile that could occur when an x-ray probe passes through a plasma. The merits of using a Hartmann sensor include a wide dynamic range, broadband or low-coherence-length light capability, high x-ray efficiency, two-dimensional gradient determination, multiplexing capability, and experimental simplicity. Hartmann sensors could also be utilized for wavelength testing of extreme-ultraviolet lithography components and x-ray phase imaging of biological specimens.

Journal Article↗
PubMed1984

Ray resection in the dysvascular foot. A retrospective review.

Twenty-nine ray resection amputations of the lower extremity were performed in 25 dysvascular patients during a four-year period. The indications for amputation were localized gangrene, resistant localized osteomyelitis of a metatarsal, or both. Specific criteria included: (1) foot Doppler pressure of 70 mm Hg, (2) ankle-arm Doppler arterial pressure ratio of at least 0.5, (3) lateral ray resection only when healthy tissue margins could easily be produced, and (4) central ray resection only for persistent deep infection resistant to local treatment. Only 31% healed without further amputation or ulceration. Analyzed retrospectively, the results demonstrate that ray resection has a poor potential for success in the presence of "localized" gangrene and is only moderately successful in the treatment of chronic resistant localized infection.

Amputation, Surgical↗
PubMed1987

Simultaneous multifrequency observations of Markarian 421.

The highly variable BL Lacertae object Mrk 421 has been observed simultaneously in the radio, optical ultraviolet, and X-ray bands over a period of 4 days in early 1984 December and once again in early 1985 January. Using the EXOSAT observatory, we found that dramatic changes occurred in the X-ray flux on a time scale of less than a mouth. During this time the 2-10 keV flux dropped by a factor of 8, whereas the 0.1-1 keV flux decreased by a factor of only 2. These changes were not reproduced at longer wavelengths during the period of simultaneous observations. However, a drop in the ultraviolet flux occurred some months later, which is consistent with the longer characteristic loss times for the lower energy electrons. Since the ultraviolet through radio flux is stable when the X-ray flux is changing, it is extremely unlikely that a simple synchrotron model can account for the full spectrum; in this model the whole spectrum is expected to rise uniformly and in phase as a result of the injection of energetic particles. A simple synchroton self-Compton model that is self-absorbed in the radio also requires an X-ray flux which is many orders of magnitude greater than is observed. However, this discrepancy may be explained by relativistic beaming of electrons with delta > approximately 40 or by a model in which the self-absorption turnover occurs in the optical, and the synchrotron break occurs in the X-rays. Shorter time scale (approximately 10,000 s) variability was also apparent in the 2-10 keV X-ray light curves, and we suggest that it may be a direct measure of the injection time scale. Although reasonable fits resulted when the X-ray data were compared with a simple power-law model with some absorption, a substantial improvement in chi 2 was obtained by adding a high-energy exponential cutoff. Use of this model produced a spectral index close to that typically found in the optical for BL Lacertae objects, in contrast to the high values usually inferred from X-ray spectra.

Astronomical Phenomena↗
PubMed2006

Diagnosis of aseptic deep venous thrombosis of the upper extremity in a cancer patient using fluorine-18 fluorodeoxyglucose positron emission tomography/computerized tomography (FDG PET/CT).

We describe a patient with a history of recurrent squamous cell carcinoma of the tongue and abnormal FDG uptake in the left arm during a re-staging FDG PET/CT. After revision of the patient's clinical history, tests and physical exam, the abnormal FDG uptake was found to correspond to an extensive aseptic deep venous thrombosis of the upper extremity.

Carcinoma, Squamous Cell↗
PubMed2006

Refraction-angle resolution of diffraction enhanced imaging.

As a new method, x-ray diffraction enhanced imaging (DEI) has extremely high sensitivity for weakly absorbing low-Z samples in medical and biological fields. Conventional performance parameters, such as spatial resolution and low-contrast resolution, are not enough to describe the characteristics of a DEI system. This paper focuses on refraction-angle resolution which describes the ability of a DEI system to differentiate the x-rays refracted by the sample. The analysis of refraction-angle resolution is composed of two parts: the analysis of the single DEI image measured in a certain position of the rocking curve and the analysis of the refraction-angle image calculated by extraction methods. A 2D computer simulation experiment is performed to prove the results of the analyses. The limitations and conclusions of refraction-angle resolution are described in the end.

Algorithms↗
PubMed1989

Radiographic quality and radiation protection in general medical practice and small hospitals.

Radiation protection and image quality were assessed in a survey of 22 general medical practices and the 24 smallest hospitals with x-ray facilities. Limited radiography, usually of extremities for trauma, was being performed in these facilities since access to regular radiology services was restricted, mainly for geographic reasons. An anthropomorphic ankle phantom with simulated fractures was presented at each facility for radiography, and the resulting films assessed for radiographic technique and basic diagnostic usefulness. While the standard of radiographic techniques was lower than in regular x-ray departments, most films of the phantom ankle were still diagnostically useful and only 4 were rejected entirely. The principal deficiency in general practice x-ray was in darkrooms and x-ray film processing. Generally, the x-ray equipment was adequate for the range of procedures performed and complied with the National Radiation Laboratory Code of Safe Practice for the Use of X-rays in Diagnosis (Medical). Radiation doses to the ankle phantom ranged widely for effectively the same procedure although none was excessive. Improved x-ray film processing, and tighter x-ray beam collimation, would result in a narrower range of doses to patients. Personnel exposures to radiation were satisfactorily low and special shieldings are not required in general practice.

Adult↗
PubMed2000

Charging phenomena in PEEM imaging and spectroscopy.

Spectromicroscopy with the imaging technique of X-ray photoelectron emission microscopy (X-PEEM) is a microchemical analytical tool installed in many synchrotron radiation laboratories, and which is finding application in diverse fields of research. The method of sample analysis, X-ray absorption spectroscopy, does not encounter the same problems as X-ray photoemission spectroscopy when sample charging occurs, hence even good insulators may often be analyzed without any apparent artifacts in images or spectra. We show, however, that charging effects cannot be neglected. We model the effect of surface charge formation on the secondary electron yield from uniform samples to demonstrate that surface charge primarily reduces the yield of electrons which may contribute to the detected signal. We illustrate that on non-uniform insulating samples, localized centers of charge may substantially affect microscope imaging and resolution as the electrostatic field close to the surface is distorted. Finally, in certain circumstances non-uniform surface charge may lead to unexpected lineshapes in X-ray absorption spectra causing, in some extreme cases, negative spectra. These negative spectra are explained, and several strategies are reviewed to minimize the impact of sample charging when analyzing poorly conducting samples of any nature.

Artifacts↗
PubMed2006

Imaging of sports injuries of the upper extremity in children.

Competitive athletics in school-aged children has become the norm rather than the exception. The increased repetitive stresses placed on the upper extremity in a wide variety of sports result in a host of injuries unique to the skeletally immature athlete. This article focuses on a discussion of the more common upper extremity injuries encountered in the child athlete and the role of radiography and MRI in diagnosis and management.

Acute Disease↗
PubMed1987

Bone and joint disorders in the upper extremities of chipping and grinding operators.

X-ray examinations of the wrists, the elbows and the shoulders were carried out on 67 vibration-exposed foundry workers and on 46 comparable referents performing heavy manual work. Both groups had a mean age of 39.6 years. Musculoskeletal symptoms, such as arthralgias of the wrist and elbow joints, muscle pain and decreased muscular force, were found to be significantly increased in the chipping and grinding workers compared with the referents. After adjustment for age, the prevalence of cysts in the metacarpal and carpal bones was almost the same in the two groups, whereas radiological signs of osteoarthritis in the wrist joint were more frequent among the vibration-exposed workers (P less than 0.025). The overall prevalence of radiographic abnormalities in the elbow joint was higher in the vibration group than in the reference group (P less than 0.025). Olecranon spurs were observed in 50.7% of the exposed operators and in 28.2% of the referents (P less than 0.025). No difference in the prevalence of radiological changes in the should could be demonstrated between the populations studied. In both groups injuries of bones and joints were not associated with age. Among the chipping and grinding operators, a slight but not significant trend in the prevalence of skeletal abnormalities with increasing vibration exposure was observed. The results of this study indicate that the foundry workers using vibrating tools were affected with bone and joint disorders in the elbow and, to a lesser extent, in the wrist, which occurred more frequently than was observed in unexposed referents, who performed solely heavy manual activity. Among the vibration-exposed workers, no relationship between radiological changes in the upper limbs and symptoms of vibration white finger was found, pointing out that different pathogenic mechanisms are involved.

Adult↗
PubMedDate not supplied

Effective follow-up strategies in soft tissue sarcoma.

The value of surveillance for detection of recurrences in patients with soft tissue sarcoma (STS) after definitive surgical resection of the primary tumor is based on the premise that early recognition and treatment of local or distant recurrence can prolong survival. Surveillance strategies should meet the criteria of easy implementation, accuracy, and cost-effectiveness. Although guidelines have been proposed for follow-up of patients with STS, there are few data in the medical literature on the effectiveness of these recommendations. We reviewed the effectiveness of a surveillance program for primary extremity STS in an effort to provide an evidence-based rationale for follow-up of STS. We concluded that clinical assessment of patient symptoms, chest X-ray imaging, and physical examination are effective strategies for follow-up of extremity STS. Chest X-ray imaging also appears to be cost-effective, at least for high-grade extremity STS. Imaging of the primary extremity site by computed tomography (CT) scan or magnetic resonance imaging (MRI) on an annual basis and routine laboratory blood tests were ineffective strategies for recurrence detection. However, certain patient characteristics such as body habitus, previous radiation therapy, and location of the primary tumor site may require the use of CT scans and MRI for adequate clinical assessment. The role of specific surveillance strategies for recurrence detection for sarcomas of the trunk, head and neck, retroperitoneum, and viscera has yet to be defined.

Continuity of Patient Care↗
PubMed1999

Quadriceps strength in women with radiographically progressive osteoarthritis of the knee and those with stable radiographic changes.

OBJECTIVE: To explore the relationship between lower extremity weakness and the progression of established radiographic changes of knee osteoarthritis (OA). METHODS: The study cohort of 342 elderly subjects was recruited from central Indiana by random digit dialing. We analyzed 79 subjects who had definite radiographic changes of unilateral or bilateral knee OA at baseline and for whom baseline data for lower extremity muscle strength and lean tissue mass and baseline and followup assessments of knee pain were available. Radiographs were graded for severity of OA at baseline and again about 2.5 years later (mean 31.5 months). Knee pain was evaluated at the same examination. Strength of the knee flexors and extensors was assessed bilaterally at baseline by isokinetic dynamometry and lower extremity muscle mass by dual energy x-ray absorptiometry. RESULTS: Mean peak knee extensor strength of women with progressive OA, before and after adjustment for lower extremity muscle mass, was about 9% lower than that in those with stable radiographic changes, but this difference was not statistically significant. No difference was apparent between the 2 groups with respect to knee flexor (hamstring) strength. The decrease in quadriceps strength among women with progressive OA, relative to those with stable OA, did not appear to be attributable to knee pain, and knee extensor strength at baseline bore no apparent relationship to the development or progression of knee pain among those with OA. CONCLUSION: We have shown previously that quadriceps weakness may be of etiologic importance in development of knee OA. The absence of a significant difference in quadriceps strength between subjects with radiographically stable OA and those whose joint damage progressed suggests that factors other than quadriceps weakness are more important determinants of OA progression.

Aged↗
PubMedDate not supplied

[Results of treatment of lower leg fractures with functional lower leg casts].

INTRODUCTION: Problems, consequences and influence of immobilization on tissue and fracture healing, as well as patient's psyche and entire condition of the organism, are well known. With immobilisation patient looses a part of extremity movement. Healing of fractures and remaining tissues is a natural process, so it is usually said that fractures and tissues heal not because of immobilization, but in spite of it. The theory of treating by functional cast (PTB-patellar tendon bearing), firstly described by Sarmiento, is based on tissues natural capability to heal and on its functional guiding to the final cause. The aim of this study is to analyze our previous expirience in regard to this method. MATERIAL AND METHODS: We have studied patients from 7 to 70 years of age with fracture of one or both lower leg bones. After injury, patients were mobilized using upper leg plaster impregned bandages applied to two thirds of extremity's circumference. After X-ray control and locating the position of broken parts, patients were released with thromboprophylaxis using Acetilsalycil acid (Midol) 3 x 1 tablet per day. In some cases, where reduction of broken fragment was hard, total anesthesia was performed. In cases of oblique and spiral fractures, because of possible redislocation we have waited with application of lower leg functional cast up to 3 weeks. RESULTS: We have studied 59 patients, most of them between the age of 11 and 20. In most cases functional cast was applied after 21 to 30 days, fractures healed after 90 to 99 days and the shortening of extremities was clinically non measureable. Usually it was 24 mm. DISCUSSION: Treatment of lower leg fractures is not simple. We especially point to problems with circulation and skin which have to be controlled over and over. There are reports of rejecting operational method as a method for lower leg fracture treating. Our results are the same as those achieved by other authors. Reposition of bone fragments must be performed with special attention. It is best if it is performed during total anesthesia, because muscles are relaxed and therefore circulation gets better, intensity of pain decreases and there are no skin necroses. In few cases, at the beginning of treatment there were skin blisters which only lengthened the treatment. These problems were prevented by early reposition, retention of bone parts and elevation of extremities. CONCLUSION: Lower leg functional cast gives excellent results in treating diaphyseal lower leg fractures. Early mobilization positively influences the patient's psyche and enables quick resocialization. Physical treatment is usually not necessary.

Adolescent↗
PubMedDate not supplied

Hyperthermic treatment of sporotrichosis: experimental use of infrared and far infrared rays.

We used pocket warmers and infrared and far infrared rays to treat 14 cases of sporotrichosis, 7 in children and 7 in adults. There were 9 cases of the fixed cutaneous type and 5 of the lymphocutaneous type; 6 were located on the face and 8 on the limbs. Four cases were treated with pocket warmers, 5 with infrared rays, and 5 with far infrared rays. All lesions treated with pocket warmers were facial lesions in children; infrared and far infrared ray treatments were used in 3 children and 7 adults, 2 on facial lesions and 8 on lesions on the extremities. In treatments with infrared and far infrared rays, the amount of heat was greater than with the pocket warmers, and one 15-min treatment daily was sufficient to yield satisfactory results, but this method is difficult to use on children and on the face, and 40-min treatments two or three times a week proved unsatisfactory. Infrared and far infrared ray treatments allow the length of a single treatment to be reduced by three-quarters, in comparison with one pocket warmer treatment.

Adult↗
PubMed2002

Cervical myelopathy due to a "tight dural canal in flexion" with a posterior epidural cavity.

A 41-year-old man noticed weakness and atrophy in his right hand and forearm resembling the non-progressive juvenile muscular atrophy of unilateral upper extremity (Hirayama's disease). MRI showed an abnormal cavity in the posterior epidural space which appeared on neck flexion communicating with the subarachnoid space in addition to the flattening of the lower cervical spinal cord on neck flexion. When evaluating atypical cases of Hirayama's disease, the pathomechanism demonstrated in the present case should be taken into consideration.

Adult↗