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At least 109 records · Page 6Linked to original sources
PubMed1989

[Radiographic examination of the thorax, fluoroscopy and echocardiography in cardiac calcification].

The value of radiographic examination of the thorax, fluoroscopy and echocardiography in demonstration and localization of intracardiac calcifications were compared in an investigation of 40 patients with valvular heart disease prior to planned cardiac catheterization or operation. Radiographic examination of the thorax revealed only the most severe calcifications. By means of echocardiography it proved possible to undertake a simple semi-quantitative characterisation of the calcified tissue with acceptable intra- and inter-observer variation. Echocardiography and fluoroscopy were found to be of equal value in demonstration of the degree of calcification of the heart. Echocardiography was, however, superior to fluoroscopy in fine localization of the calcifications. The relative and additive values of the methods could be illustrated employing Bayes' theorem and could be represented graphically provided that the observations carried out with the three methods could be considered independent of one another. It is concluded that radiographic examinations of the thorax is unsuitable for screening for cardiac calcifications. Fluoroscopy can no longer be considered to be the method of choice in assessing lesions of this type but should be employed in cases where echocardiography does not provide sufficient information or is not available. The greatest certainty in demonstration of calcifications is obtained with combined employment of fluoroscopy and echocardiography.

Adult↗
PubMed1987

[Value of computerized tomography of the thorax in germinal testicular tumors].

Sporadic informations in the literature that by means of CT of the thorax by far smaller intrapulmonary foci can be recognized in comparison to the conventional x-ray examination are just to be confirmed. With the help of instances the indication for thorax CT in germinal testicular tumours is presented. The evidence and exclusion, respectively, of pulmonary metastases are of decisive importance actually for the therapy and prognosis in patients with germinal testicular tumours. In this respect our observations confirm the indications for a CT-examination of the thorax in these groups of patients.

Adult↗
PubMed1980

[Studies of X-ray morphology of the heart contour in ischemic heart disease as seen in dorsoventral X-ray photography of the thorax in the basis of coronarographic findings (author's transl)].

Cardiovascular diseases hold a place of considerable importance in national health schemes and various screening methods have been devised to determine and to control such diseases. One of the methods is based on the use of thorax photofluorographs obtained from regular nation-wide X-ray examinations. The ischemic heart disease is a significant group among cardiovascular diseases and it appears that dorsoventral photofluorography is an insufficient means for its recognition. For 250 subjects examined by intracardial methods for suspected ischemic heart disease, a retrospective study of dorsoventral thorax photofluorographs was performed along the lines of the classification by Richter and Böck. The results show that in about 75 percent of the cases of ischemic heart disease associated with serious lesions of the coronary vessels, no signs of changes in the heart contour were seen in photofluorographs of the thorax. It is concluded that the evaluation of chestfilm is an inadequate approach as far as the ischemic heart disease group is concerned within photofluorographic screening programmes for cardiovascular diseases.

Cardiac Catheterization↗
PubMed1995

[Spiral CT of the thorax with double table feed in relation to slice thickness].

PURPOSE: The aim of the study was to reduce investigation time, radiation dose, and contrast material when performing spiral-CT of the thorax. METHODS: 50 patients with different clinical diagnoses underwent spiral-CT of the thorax with double table feed and 45 ml contrast material (lopentol) were injected. Density measurements were performed as follows: main pulmonary artery without contrast injection, carotid artery, subclavian artery, ascending and descending aorta, aortic arch, main pulmonary artery and thoracic aorta after contrast injection. RESULTS: In comparison to the density of the main pulmonary artery without contrast injection there was an increase of density of 134 HU. 45 ml of the contrast agent were sufficient in all cases for delineation of the mediastinal vessels. Investigation time was 16-18 s and all patients were able to hold their breath during this time, so no artifacts were seen. Radiation dose was cut in half. CONCLUSION: Spiral-CT with double table feed enables investigations of the thorax in less than 20s. 45 ml of a contrast agent are sufficient for performing this examination. There are no essential diagnostic deficits with this technique.

Absorptiometry, Photon↗
PubMed1996

[Early treatment of the unstable thorax in polytrauma].

Thoracic trauma represents 12.8% of all trauma patients treated in author's evaluated the contribution of new diagnostic methods, in particular CT and sonography, to determinate the indication of conservative therapy or early surgical treatment. From 1992 in the framework of the grant project the early surgical treatment of instable thorax was performed in 29 patients with polytrauma or severe associated thoracoabdominal trauma. Authors determined indications for thorax stabilisation after serious consideration, and stated contemporary contraindications of this treatment. They evaluated the therapeutic contribution of these methods and prepared in cooperation with the company Medin Nové Mĕsto the set of osteosynthetic material with accessories for treatment of instable thorax.

Flail Chest↗
PubMed1998

A non-fatal impalement injury of the thorax.

Impalement is an uncommon injury with only occasional reports in the literature. There are even fewer reports of impalement injuries limited to the thorax. We report herein the case of a 24-year-old man who survived impalement injury of the left side of the thorax with a steel rod while working at a construction site. The great vessels of the thorax were spared but the second thoracic vertebra was fractured resulting in complete paralysis of the left lower limb. The precise nature and extent of the injury were determined pre-operatively by computed tomography and aortography. The important principles of surgical management contributing to the successful outcome are described, these being minimal manipulation of the impalement object before and during transport, careful pre-operative planning and a multidisciplinary approach.

Accidents, Occupational↗
PubMed1992

Anatomically derived attenuation coefficients for use in quantitative single photon emission tomography studies of the thorax.

Elimination of errors due to poor attenuation correction is an essential part of any quantitative single photon emission tomography (SPET) technique. Attenuation coefficients (mu Tc) for use in attenuation correction of SPET data were determined using technetium 99m and cobalt 57 flood sources and using topographical information obtained from computed tomography (CT) scans and magnetic resonance (MR) images. In patients with carcinoma of the bronchus, the mean attenuation coefficient for 99mTc was 0.096 cm-1 when determined across a transverse section of the thorax at the level of the tumour by means of a 57Co flood source (13 patients) and 0.093 and 0.074 cm-1 as determined from CT scans for points in the centre of the tumour and contralateral normal lung, respectively (21 patients). In 18 patients with breast tumours, the mean attenuation coefficient for 99mTc was 0.110 and 0.076 cm-1 when determined from MRI cross-sections for points in the centre of the tumour and normal contralateral lung, respectively. This indicates significant overcorrection for attenuation when the conventional value of 0.12 cm-1 is used. A value in the range 0.08-0.09 cm-1 would be more appropriate for SPET studies of the thorax. An alternative approach to quantitative region of interest (ROI) analysis is to perform attenuation correction appropriate to the centre of each ROI (using topographical information derived from CT or MRI) on non-attenuation-corrected reconstructions.

Breast Neoplasms↗
PubMedDate not supplied

Impedance tomography: computational analysis based on finite element models of a cylinder and a human thorax.

A direct image reconstruction method of electrical impedance tomography (EIT) is evaluated using three-dimensional (3-D) finite element models of cylindrical and torso-shaped volume conductors. The cylindrical model is used to examine the effect of electrode configurations and the sensitivity to off-plane objects and to noise in the measured data. It is also used to validate the modeling procedures by comparison with experimental data acquired from a similar cylindrical tank filled with saline. Simulation results show only minor differences in performance between the various electrode configurations. In the second part, a realistic human thorax model constructed from CT images is used to evaluate monitoring of pulmonary edema by EIT. The conductivity, volume, and vertical position of an abnormal region in the lungs are varied to simulate the progress of edema. Dynamic EIT images are reconstructed from data computed for the inhomogeneous thorax (heart and lungs) as the reference set and a realistic amount of noise is added to reproduce the conditions in which the technique would be used in practice. Simulation results show that a 10 ml edema region with a conductivity equal to that of blood can be detected at a 40 dB signal-to-noise ratio (SNR). Detection of a smaller volume, in the order of 2 ml, should be possible by improving either the instrumentation to achieve 60 dB SNR or the performance of reconstruction algorithms.

Cardiography, Impedance↗
PubMed1992

A computer model for the study of electrical current flow in the human thorax.

Electrocardiography has played an important role in the detection and characterization of heart function, both in normal and abnormal states. In this paper we present an inhomogeneous, anisotropic computer model of the human thorax for use in electrocardiography with emphasis on the calculation of transthoracic potential and current distributions. Knowledge of the current pathways in the thorax has many applications in electrocardiography and has direct utility in studies pertaining to cardiac defibrillation, forward and inverse problems, impedance tomography, and electrode placement in electrocardiography.

Computer Simulation↗
PubMed1989

Rotational and translational movement features of the pelvis and thorax during adult human locomotion.

The kinematics of the pelvis and thorax are important in gait studies since their movement patterns are closely related to gait efficiency and 'smoothness' of locomotion. The purpose of this study was to identify features of normal gait patterns for later comparisons with pathological and developmental gait patterns. A two camera SELSPOT system interfaced with an HP1000 minicomputer was used to obtain three-dimensional kinematic/temporal data for the pelvis and thorax. Data from treadmill walking of eight adults were used for within subject (at different speeds) analyses. The analyses revealed a very complex pattern with a set of breakpoints which was consistent over all subjects. Some features were invariant over a range of walking speeds although the total range of motion changed considerably.

Adult↗
PubMed2005

Magnetic material in head, thorax, and abdomen of Solenopsis substituta ants: a ferromagnetic resonance study.

Ferromagnetic resonance temperature dependence is used to study the magnetic material in smashed head, thorax, and abdomen of Solenopsis substituta ants. These three body parts present the five lines previously observed in other social insects. The magnetic material content is slightly higher in heads with antennae than in abdomen with petiole. Isolated nanoparticle diameters were estimated as 12.5 +/- 0.1 and 11.0 +/- 0.2 nm in abdomen with petiole and head with antennae, respectively. The presence of linear chains of these particles or large ellipsoidal particles are suggested. A bulk-like magnetite particle was observed in the thorax. The Curie-Weiss, the structural-electronic and ordering transition temperatures were obtained in good agreement with those proposed for magnetite nanoparticles.

Abdomen↗
PubMed2005

Neck and shoulder muscle activity and thorax movement in singing and speaking tasks with variation in vocal loudness and pitch.

The aim of this study was to examine respiratory phasing and loading levels of sternocleidomastoideus (STM), scalenus (SC), and upper trapezius (TR) muscles in vocalization tasks with variation in vocal loudness and pitch. Eight advanced singing students, aged 22 to 28 years, participated. Surface electromyographic (EMG) activity was recorded from STM, SC, and TR. Thorax movement was detected by two strain gauge sensors placed around the upper (upper TX) and lower (lower TX) thorax. A glissando and simplified singing and speaking tasks were performed. Sustained vowels /a:-i-ae-o:/ were sung in a glissando from lowest to highest pitch (mixed voice/falsetto) back to lowest pitch and in short singing sequences at comfortable, low, and high pitches. The same vowels were spoken softly and loudly for about the same length. The subjects inhaled between the vowels. It was concluded that the inspiratory phased STM and SC muscles produced a counterforce to compression of upper TX at high pitches in glissando. STM and SC were activated to higher levels during phonation than in inhalation. As breathing demands were reduced, STM and SC activity was lowered and the respiratory phasing of peak amplitude changed to inhalation. TR contributed to exhalation in demanding singing with long breathing cycles, but it was less active in singing tasks with short breathing cycles and was essentially inactive in simplified speaking tasks.

Adult↗
PubMed2001

Imaging of beta-adrenoceptors in the human thorax using (S)-[(11)C]CGP12388 and positron emission tomography.

We report positron emission tomography studies of beta-adrenoceptors in the human thorax with (S)-[(11)C]CGP12388 (4-(3-(2'-[(11)C]-isopropylamino)-2-hydroxypropoxy)-2H-benzimidazol-2-one). Beta-adrenoceptors have previously been quantified using (S)-[(11)C]CGP12177 (4-(3-tert-butylamino-2-hydroxypropoxy)-2H-benzimidazol-2[(11)C]-one), but (S)-[(11)C]CGP12388 is more easily prepared and therefore more suitable in a clinical setting. (S)-[(11)C]CGP12388 was administered to five healthy volunteers on two separate days (control and pindolol block study). Arterial plasma samples were used to determine clearance, metabolites, and protein binding of the radioligand. Heart, lung and spleen showed high uptake of radioactivity, which was strongly suppressed (68-77%) by pindolol. Plasma clearance of (S)-[(11)C]CGP12388 was rapid, binding to plasma proteins was low (53+/-4%), and the radioligand was slowly metabolized. (S)-[(11)C]CGP12388 produces high-quality images of the human thorax. Uptake of (S)-[(11)C]CGP12388 in heart, lung and spleen represents binding to beta-adrenoceptors. (S)-[(11)C]-CGP12388 seems useful for imaging of beta-adrenoceptors in a clinical setting.

Adult↗
PubMed1998

Ultrasonography of the thorax (excluding the heart).

Until recently, ultrasonography has had a subordinate role in the evaluation of the thorax in both small animals and humans, most likely due to the inability of sound to penetrate air-filled lung. When pathologic processes such as pleural effusion and lung consolidation provide an acoustic window to the thorax, however, thoracic ultrasonography becomes feasible. As this article illustrates, ultrasonography may be effectively employed in the diagnosis and management of various thoracic wall, pleural, mediastinal, pulmonary, and diaphragmatic diseases by providing valuable information not obtainable with routine radiography and enabling percutaneous aspiration or tissue core biopsy of lesions.

Animals↗
PubMed2004

Combination of finite element modeling and optimization for the study of lumbar spine biomechanics considering the 3D thorax-pelvis orientation.

A model of the lumbar spine capable of taking into account realistic loads derived from human activity would be of great benefit in studying its normal biomechanical functioning as well as its in vivo behavior in injured and surgically altered states. This paper proposes a method to analyze the mechanical response of the lumbar spine subjected to loads derived from human activity, combining a non-linear finite element model (FEM) and an optimization-based force predicting algorithm. Loads borne by the lumbar spine at the T12-L1 level (joint loads) are first predicted with the optimization algorithm and then applied to the FEM, while a boundary condition prescribing the relative L1-sacrum rotation is imposed onto the FEM to account for three-dimensional physiological thorax-pelvis orientation. The prescribed rotation is achieved through the application of moments on L1. To account for the effect of these moments on lumbar joint loads, an iteration between the optimization technique and the FEM computation has been carried out. This method provides two main benefits over previous studies: first, it allows for the application of any 3D loading condition while considering the real 3D rotation measured between the thorax and the pelvis, and second, it makes it possible to estimate the moments that must be applied on L1 in order to maintain this rotation, taking them into account when predicting joint loads. As an example application of the method, results are presented for the lumbar spine mechanical response at the time of peak T12-L1 joint force during walking.

Algorithms↗
PubMed2006

Preliminary study on the effects of bar placement on the thorax after the nuss procedure for pectus excavatum using bone scintigraphy.

AIM: Bone scintigraphy was performed to elucidate the effects of the Nuss procedure for pectus excavatum on the bony thorax. METHODS: Eight boys and 6 girls (5 - 24 years of age) underwent bone scintigraphy, using (99m)Tc-HMDP. Eleven patients were studied 5 to 21 days after the Nuss procedure; 6 were studied 20 to 24 months after the operation before bar removal. Three of 14 were studied twice after the Nuss procedure and before bar removal. RESULTS: In the early postoperative phase, RI accumulation was found at the sternum and ribs in only 1 of 6 patients under 9 years of age, whereas in all 5 older patients, RI had accumulated at the sternum. Scintigrams before bar removal revealed, regardless of age, hot spots at the lateral ribs in contact with the bar and at the costochondral junctions where the bar passed through the intercostal spaces. Furthermore, chest roentgenograms showed the deformed lateral ribs in contact with the bar. CONCLUSIONS: The Nuss procedure creates minute fractures at the sternum and the ribs, especially in older patients. The bar deforms the ribs and restrains the growth of the thorax. Furthermore, it constantly rubs against the ribs and can therefore cause late complications. Bone scintigraphy may determine the appropriate timing for bar removal.

Adolescent↗
PubMed1982

Genes controlling segmental specification in the Drosophila thorax.

The roles of three homeotic genes, Ubx+, Scr+, and Antp+, in the Drosophila thorax have been studied by determining the cellular phenotypes of mutations resulting in loss of gene function. The principal results are: (i) The Scr+ and Ubx+ genes are required in the prothorax and metathorax, respectively; in the absence of these genes, both segments develop like the mesothorax. (ii) The Antp+ gene is required in all three thoracic segments: in its absence, parts of the mesothorax are transformed into corresponding parts of the antenna, and similar transformations to antenna are found in the prothorax and metathorax if the Scr+ and Ubx+ genes also are absent. (iii) Loss of the Ubx+ gene early in embryogenesis, but not later, leads to the inappropriate activity of the Scr+ gene in the meso- and metathorax. Results i and ii argue strongly that segmental determination is specified in a combinatorial fashion in the head and thorax by the selective activities of the Scr+, Ubx+, Antp+, and putative head-determining genes. Result iii suggests that a product of the Ubx+ gene also plays an early, regulatory role in ensuring the correct spatial expression of the Scr+ gene during subsequent development.

Animals↗
PubMedDate not supplied

Morphological growth and thorax dimensions among Tibetan compared to Han children, adolescents and young adults born and raised at high altitude.

BACKGROUND: Studies comparing the growth of indigenous high-altitude Aymara children and children of low-altitude European descent who have been born and raised at high altitude in the Andes have provided evidence for genetically-determined differences in thorax growth, as well as for population differences in height, weight and other measures of overall size. Comparable studies now can be undertaken in Asia because of the growing number of Han Chinese who have been born and raised at high altitude on the Qinghai-Tibetan Plateau. AIM: The study compares the growth of indigenous Tibetan children and children of Han descent who have been born and raised at the same high altitudes, and under similar socio-economic conditions. SUBJECTS AND METHODS: Measurements of stature, sitting height, weight, triceps and subscapular skinfolds, upper arm muscle area, transverse chest diameter, anterio-posterior chest diameter, and chest circumference were taken on 1439 Tibetan and Han males and females between the ages of 6 and 29 years who were born and raised 3200 m, 3800 m or at 4300 m in the high altitude province of Qinghai in western China. RESULTS: Han-Tibetan differences in body size do not occur systematically for any measurement, for any age group, or for either gender; nor is there a systematic pattern of body size differences between 3200 m and 4300 m. This indicates that there are no differences in general growth between the two groups at high altitude in Qinghai, although both groups grow more slowly than urban children at low altitude in China. On the other hand, Tibetan males possess significantly deeper chests than Han males, and Tibetan females possess significantly wider chests than Han females. Tibetans of both sexes possess significantly larger chest circumferences than Han males and females. CONCLUSIONS: Although genetic similarities cannot be ruled out, comparable dietary stress is a likely explanation for the similar and slow morphological growth of Han and Tibetans at high altitude. However, Han-Tibetan differences in thorax dimensions are likely a consequence of population (genetic) differences in the response to hypoxia during growth.

Adolescent↗