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At least 307 records · Page 17Linked to original sources
PubMed1978

[Roentgen diagnosis of injuries of the ankle joint (author's transl)].

Lesions of the ankle joint affect the bone and/or ligaments. It will often be necessary to conduct additional radiological examinations besides the standard x-ray films. These additional examinations should include: 1. roentgenograms taken at an oblique angle; 2. x-ray films taken in forced extreme joint position in two planes; 3. roentgenograms comparing right and left; 4. arthrography. The article discusses the value and significance of the additional roentgenograms, with particular reference to the importance of the films of the forced extreme joint position.

Ankle Injuries↗
PubMed1982

[Arthrography as a diagnostic measure in injuries of ligament and capsule of the ankle joint (author's transl)].

The application of monocontrast arthrography in examining the ankle joint is demonstrated by means of an extensive series of examinations. It is evident that this method of examination is more reliable than x-ray films of the forced extreme joint position, especially in combined injuries of the ligamentous apparatus, so that it enables better planning of the necessary therapeutic procedure.

Adolescent↗
PubMed1993

[A case of superior vena cava syndrome caused by adenocarcinoma of the mediastinum--the significance of pulsed Doppler echocardiography in the SVC reconstruction].

We report a case of SVC syndrome caused by adenocarcinoma of the mediastinum, in which brachiocephalic vein flow was recorded by pulsed Doppler echocardiography before and after the SVC reconstruction. A 46-year-old man was admitted to the hospital with the chief complaints of edema of the face and the upper extremities. Although chest X-ray film showed no abnormalities, chest CT and SVC-graph demonstrated the obstruction of SVC and bilateral brachiocephalic veins. It was found that bilateral brachiocephalic vein flow displayed characteristic one-peak shaped pattern and the peak flow velocity was decreased. We removed SVC and bilateral brachiocephalic veins with the surrounding tissue, and SVC and tributaries were reconstructed with 10 mm ringed ePTFE grafts. Histological examination revealed carcinoma cell infiltration in the wall of SVC. Postoperative phlebography showed well patent grafts, and bilateral brachiocephalic vein flow pattern normalized and the peak flow velocity remarkably increased.

Adenocarcinoma↗
PubMed1993

[The omitted x-ray examination--benefit and risk--a comparison].

Today the risk of omission of an x-ray examination is often underestimated compared with the assumed stochastic - i.e. random - risk of radiation exposure associated with the x-ray examination. The benefit of the x-ray examination can be estimated by considering how it influences the diagnostic decision and the therapy. Three degrees of justification (indication) supply proof of different degrees of the proportion of benefit gained. It is evident that some of the x-ray examinations that are being performed, are unnecessary, whereas on the other hand even so-called routine x-ray examinations can yield a therapeutically relevant finding in some patients. A comparison of benefit and risk shows that the estimated benefit exceeds the assumed irradiation risk by several orders of magnitude. This is exemplified by examinations of the thorax and lumbar vertebral column. The guidelines issued by the German Federal Chamber of Physicians on quality assurance in x-ray diagnostics and CT result in a considerable reduction of patient doses. Advantage must be taken of the benefit of x-ray examinations performed with an extremely critical eye on the relevant indication and with minimised irradiation exposure. Omitting an indicated examination may endanger the patient to such an extent that major neglect of the irradiation risk is warranted.

Humans↗
PubMed2004

Dose reduction in skeletal and chest radiography using a large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide: technical background, basic image quality parameters, and review of the literature.

The two most frequently performed diagnostic X-ray examinations are those of the extremities and of the chest. Thus, dose reduction in the field of conventional skeletal and chest radiography is an important issue and there is a need to reduce man-made ionizing radiation. The large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide provides a significant reduction of radiation dose in skeletal and chest radiography compared with traditional imaging systems. This article describes the technical background and basic image quality parameters of this 43 x 43-cm digital system, and summarizes the available literature (years 2000-2003) concerning dose reduction in experimental and clinical studies. Due to its high detective quantum efficiency and dynamic range compared with traditional screen-film systems, a dose reduction of up to 50% is possible without loss of image quality.

Cesium↗
PubMed1991

[Computer-assisted data analysis of injuries of the skeletal system in polytrauma patients].

The data of 366 patients with multiple injuries were evaluated by application of data processing over a period of seven years. Age and sex distribution, location and combination of injuries, mortality, mechanism of accident, diagnostics as well as therapy were analysed. 91.3% of our patients had injuries of the skeleton. The male to female ratio was 2:1. In 55.4% the age of the patients ranged from 10 to 39 years. The mortality rate of all patients was 27.2%. In the third decade only 16.9% of the patients died. Whereas the mortality of the patients in the 1. decade as well as between the 7. and 9. decades of life was very high (33% and 50%). Most of the skeletal injuries were located in the shank (24% open fractures). The mortality rate increases with the number of injuries (Table III). Patients with concomitant injuries, such as head injuries and fractures of the extremities were the most common combination of multiple injuries. 20% of the patients in this group died. Patients with combined injuries of the head, chest, abdomen and skeleton had highest mortality (57%). X-ray examination of the skull, chest, extremities and mainly of the spine and pelvis should be subjects of routine diagnostics. In patients who were suspected of having a blunt abdominal trauma, the first diagnostic technique will be ultrasound. On account of the various number of concomitant injuries as well as the patients individuality, the estimation of prognosis by systems for the classification of the severity of injury is fraught with difficulties. The analysis of the evaluated data showed that previously small number of variables may predict the prognosis of the course of disease.

Adolescent↗
PubMed1997

Toe amputations and ray resections.

Loss of a part of the lower extremity is an unfortunate complication of diabetes. Indications and general principles of amputation have been established. Distal limb salvage procedures include forefoot amputation alternatives, digital amputations, and ray resections. A variety of risks and complications are associated with these procedures. Postoperative management including prosthetic and accommodative therapy may enhance the successful outcomes of these procedures.

Amputation, Surgical↗
PubMed2002

Comparison of two methods used to assess first-ray mobility.

Mobility of the first-ray is associated with several common lower extremity disorders. However, the reliability and validity of clinical measurement remains unclear. In this study we examined first-ray mobility by using one hand to stabilize the lesser metatarsals while the clinician's other hand applied a displacement force to the head of the first metatarsal. The amount of mobility was graded as stiff, normal or hypermobile. We then used a well-validated mechanical device to perform similar tests and assessed validity, intrarater reliability and interrater reliability. Three clinicians having varied levels of experience graded first-ray mobility on 15 subjects. A separate investigator measured dorsal mobility with a mechanical device. Both methods of testing were repeated to assess measurement reliability. Reliability was estimated by kappa (K) statistics. Spearman correlation assessed the relationship between mobility graded manually and dorsal mobility measured by device. Manual examination intrarater K values ranged from 0.50 to 0.85, and interrater agreement from 0.09 to 0.16. Manual grading was not related (r = -0.21) to the absolute measure of total dorsal mobility made by device. This brings into question the validity and reliability of manual estimates of first-ray mobility.

Adult↗
PubMed1995

Bone mineralization changes in saw operators.

In vibration disease the impact on bone and joint systems is considered to be the least frequent one. It includes a degenerative component, rare necrotic alteration and osteoporosis, together with cystic alterations, in the carpal bones. The authors concentrated only on osteoporosis in the proximal parts of upper extremities. They evaluated by X-rays of the thorax the extent of mineralization and, consequently, the osteoporosis of the clavicles. For that purpose they used the corticodiaphyseal Barnett-Nordin index (BNI). In a group of 107 chain saw operators whose both upper extremities had been exposed to the impact of vibration exceeding the threshold limit while operating a chain saw, a statistically significant difference was established in the mineralization of clavicles. These findings contrasted with a control group of 107 healthy males who had never worked with vibrating equipment. The authors did not establish a statistically significant dependence of these changes on simultaneously diagnosed traumatic vasoneurosis and neuropathy. After the risk elimination of vibration the value of the BNI indicates the dynamics and the reversibility of the parameter under observation. These findings suggest that osteoporosis due to the impact of vibrations is by no means a rare phenomenon. It does not affect only the distal parts of the upper extremities. Similarly as angiological and neurological changes, osteoporosis tends towards spontaneous adjustment, once the risk of vibrations has been eliminated.

Adult↗
PubMed2005

Resonant soft X-ray diffraction - in extremis.

The use of softer-energy X-rays produced by synchrotron radiation for diffraction is an area of current interest. In this paper, experiments exploiting resonant scattering at the L absorption edges of 3d transition metal elements are reported. Such energies, typically 500-1000 eV, are at the extreme limit of soft X-ray diffraction where absorption effects are so severe that the sample and diffractometer must be placed in a windowless high-vacuum vessel. In addition, the Ewald sphere is so small as to likely contain, at most, only a single Bragg reflection. Advantages of using such radiation for the study of weak diffraction effects such as anomalous scattering, charge ordering, magnetic diffraction and orbital ordering are reported.

Computer Simulation↗
PubMed2006

Long gamma-ray bursts and core-collapse supernovae have different environments.

When massive stars exhaust their fuel, they collapse and often produce the extraordinarily bright explosions known as core-collapse supernovae. On occasion, this stellar collapse also powers an even more brilliant relativistic explosion known as a long-duration gamma-ray burst. One would then expect that these long gamma-ray bursts and core-collapse supernovae should be found in similar galactic environments. Here we show that this expectation is wrong. We find that the gamma-ray bursts are far more concentrated in the very brightest regions of their host galaxies than are the core-collapse supernovae. Furthermore, the host galaxies of the long gamma-ray bursts are significantly fainter and more irregular than the hosts of the core-collapse supernovae. Together these results suggest that long-duration gamma-ray bursts are associated with the most extremely massive stars and may be restricted to galaxies of limited chemical evolution. Our results directly imply that long gamma-ray bursts are relatively rare in galaxies such as our own Milky Way.

Journal Article↗
PubMed2000

Heliospheric X-ray Emission Associated with Charge Transfer of the Solar Wind with Interstellar Neutrals.

X-rays should be generated throughout the heliosphere as a consequence of charge transfer collisions between heavy (Z>2) solar wind ions and interstellar neutrals. The high charge state solar wind ions resulting from these collisions are left in highly excited states and emit extreme ultraviolet or soft X-ray photons. This solar wind charge exchange mechanism applied to cometary neutrals has been used to explain the soft X-ray emission observed from comets. A simple model demonstrates that heliospheric X-ray emission can account for about 25%-50% of the observed soft X-ray background intensities. The spatial and temporal variations of heliospheric X-ray emission should reflect variations in the solar wind flux and composition as well as variations in the distribution of interstellar neutrals within the heliosphere. The heliospheric X-ray "background" can perhaps be identified with the "long-term enhancements" in the soft X-ray background measured by ROSAT.

Journal Article↗
PubMed1996

Ultrasound for diagnosis of apophyseal injuries.

Avulsion injuries of the apophysis is a problem in young athletes. A correct diagnosis is necessary for establishing the appropriate treatment and the rehabilitation program. However, it is often difficult to distinguish between a simple muscle strain and an avulsion fracture. The X-ray examination is helpful only when an ossification center of the apophysis exists. Ultrasonography is considered the suitable diagnostic tool for these cases. From June 1988 to June 1993, 243 young athletes were seen with an anamnestic and clinically suspected apophyseal injury of the lower extremity. In all cases X-ray examination and ultrasound examination were performed. In 80 cases the diagnosis was confirmed by X-ray examination and in 97 by ultrasonography. Four criteria were defined for the sonographic examination: (a) a hypoechogenic zone, (b) increased distance to the apophysis, (c) dislocation of the apophysis, and (d) mobility of the apophysis on dynamic examination. These criteria are correlated to (a) edema, (b) lysis, (c) avulsion, and (d) unstable avulsion of the apophysis. Ultrasonography is a proven technique for the detection of apophyseal injuries. In comparison to X-ray examination, it has the advantages of no radiation exposure, early detection even without ossification center, and dynamic examination.

Adolescent↗