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At least 163 records · Page 9Linked to original sources
PubMed2005

Vascular diseases of the thorax: evaluation with multidetector CT.

The list of vascular diseases in the thorax has been narrowed to three, which are considered essential information for radiologists interpreting CT scans of the thorax: (1) aortic dissection and its variants, intramural hematoma and penetrating atherosclerotic ulcer; (2) acute pulmonary embolism; and (3) coronary artery disease. The spatial resolution of multidetector CT is such that CT has become the imaging modality of choice for aortic dissection and pulmonary embolism. This move away from angiography has transpired over the last decade; perhaps the next decade will see the same occur for evaluation of coronary artery disease.

Aortic Dissection↗
PubMed2001

Subcutaneous emphysema of the thorax heralding colonic perforation.

Subcutaneous emphysema of the thorax may follow thoracic operations for a number of essentially benign reasons and does not usually cause much concern to the thoracic surgeon. We report subcutaneous emphysema of the thorax heralding a retroperitoneal colonic perforation in a patient who had undergone coronary artery bypass grafting 3 days previously.

Aged↗
PubMed2001

Contralateral lung transplantation: a left lung implanted in the right thorax.

Since the inception of lung transplantation in 1982, it has been standard practice to implant donor lungs on the ipsilateral side in the recipient. The development of the techniques of lobar and bilateral lobar transplantation has shown that lung morphology may adapt to the shape of the thorax. Thus, variations in implantation have become possible. We describe a case of a 30-year-old man with severe bronchiectasis due to ciliary dyskinesis which required a left lower lobectomy at the age of 11 years and a left completion pneumonectomy 10 years later. His disease progressed and he was listed for a right lung transplantation. At the time of transplantation, the donor right lung was noted to be edematous and unfit for transplantation. This required grafting the donor left lung in the right thorax of the recipient. Follow-up at 7 years shows good exercise capacity and excellent functional tests without evidence of rejection.

Adult↗
PubMed1999

Thorax high resolution computerized tomography findings in asthmatic children with unusual clinical manifestations.

BACKGROUND: It has been consistently observed in high resolution computerized tomography (HRCT) scans that asthmatic patients manifest more abnormalities related to airways remodeling than do normal subjects. OBJECTIVE: To find the underlying abnormalities in the lungs of asthmatic children with unusual manifestations. METHOD: Asthmatic children not responding as expected to inhaled steroid therapy with or without localized permanent or temporary recurrent auscultation findings (rales) were evaluated with chest radiographs and HRCT scans. Bronchoscopy was performed on the ones with localized rales. RESULTS: The sample consisted of 16 asthmatic children (6 girls and 10 boys, mean age = 7.75+/-4.43 years). Chest radiograph abnormality rate was 44% and the thorax HRCT scan abnormality rate was 75% (56% fibrotic retractions, 38% atelectasis, 19% bronchiectasis, and 19% bronchial wall thickening). Two patients with localized permanent rales and with right middle lobe (RML) atelectasis in HRCT scan underwent bronchoscopy which revealed RML syndrome due to mucus plugging in one and lymph node pressure in the other. In one patient with localized temporary recurrent rales and major bronchiectasis in HRCT scan, bronchoscopy revealed bronchitis. The patient with RML syndrome due to mucus plugging required lobectomy. CONCLUSION: We conclude with this experience that thorax HRCT scanning may be a helpful adjunct in the evaluation of an asthmatic children with atypical clinical findings.

Anti-Asthmatic Agents↗
PubMed1975

[Radiographs of the thorax in acute myocardial infarction].

Radiographs of the thorax were evaluated in 240 patients during the acute phase following a myocardial infarct. Following the acute infarct, 53% of the patients showed some cardiac enlargement, in a quarter this was marked. Congestive lung changes were found in 53% of patient following the infarct, interstitial pulmonary oedema in 22% and intra alveolar oedema in 9%. Patients with marked cardiac enlargement and those with congestive lung changes showed a bad prognosis, particularly if the congestion did not regress rapidly. Even advanced pulmonary congestion and interstitial oedema may be missed by clinical examination. Radiography of the thorax following acute myocardial infarction is of value in treatment and prognosis.

Acute Disease↗
PubMed2005

Comparison of technical and anatomical noise in digital thorax X-ray images.

Former studies by Hoeschen and Buhr indicated a higher total noise in a thorax image than expected from technical noise, i.e. quantum and detector noise. This difference results from the overlay of many small anatomical structures along the X-ray beam, which leads to a noise-like appearance without distinguishable structures in the projected image. A method is proposed to quantitatively determine this 'anatomical noise' component, which is not to be confused with the anatomical background (e.g. ribs). This specific anatomical noise pattern in a radiograph changes completely when the imaging geometry changes because different small anatomical structures contribute to the projected image. Therefore, two images are taken using slightly different exposure geometry, and a correlation analysis based on wavelet transforms allows to determining the uncorrelated noise components. Since the technical noise also differs from image to image, which makes it difficult to separate the anatomical noise, images of a lung phantom were produced on a low-sensitive industrial X-ray film using high-exposure levels. From these results, the anatomical noise level in real clinical thorax radiographs using realistic exposure levels is predicted using the general dose dependence described in the paper text and compared with the quantum and detector noise level of an indirect flat-panel detector system. For consistency testing, the same lung phantom was imaged with the same digital flat-panel detector and the total image noise including anatomical noise is determined. The results show that the relative portion of anatomical noise may exceed the technical noise level. Anatomical noise is an important contributor to the total image noise and, therefore, impedes the recognition of anatomical structures.

Artifacts↗
PubMed1992

Noncardiac manifestations of rheumatoid arthritis in the thorax.

The noncardiac manifestations of rheumatoid arthritis (RA) in the thorax are complex and varied. The bony thorax, pleura, lung parenchyma, tracheobronchial tree, larynx, an upper airway can all be sites of disease. Drug therapy for RA can result in thoracic disease that is difficult to distinguish from the manifestations of RA itself. This article reviews the available literature pertinent to noncardiac thoracic manifestations of RA and focuses on clinical and radiographic presentations in order to provide an organized approach to patient care.

Arthritis, Rheumatoid↗
PubMed2001

Multidimensional imaging of the thorax: practical applications.

Over the past decade, faster CT scan times, thinner collimation, and the development of multirow detectors, coupled with the increasing capability of computers to process large amounts of data in short periods of time, have lead to an expansion in the ability to create diagnostically useful two-dimensional (2D) and three-dimensional (3D) images within the thorax. Applications within the thorax include, but are not limited to, evaluation of pulmonary and systemic vasculature, evaluation of the tracheobronchial tree, and delineation of diffuse lung disease. Pulmonary nodule volume and growth can be more accurately predicted, and represents an improvement in the evaluation of the solitary pulmonary nodule. Multiplanar images increase our understanding of thoracic anatomy and can help to guide bronchoscopic procedures. Because there are strengths and weaknesses to all the reconstruction algorithms, the utility of any given technique is dependent on the clinical question to be answered. For instance, although maximum intensity projection imaging (MIP) is helpful in the evaluation of micronodular lung disease, it is of little value in the diagnosis of aortic dissection. As the ability to generate faster and more precise multidimensional images grow, the demand for such imaging is likely to increase. In this review, the authors discuss the various reconstruction techniques available, followed by a discussion of the clinical applications.

Humans↗
PubMedDate not supplied

Osteophytes of the spine compressing the sympathetic trunk and splanchnic nerves in the thorax.

The presence of osteophytes compressing the sympathetic structures in the thorax was found in 655 (65.5%) of 1,000 cadavers. In 60.4% of the affected cases, the compression was on the right side, and in 36.9% it was bilateral, although the right side was more severely affected. In 2%, the compression was on the left only. The highest frequency of compression was at the T8-10 level, the right greater splanchnic nerve being the structure most frequently involved. The sympathetic trunk itself (ganglia and cord) was affected only by osteophytes of vertebrae at the lowest thoracic levels; however, bony excrescences due to costovertebral joint arthritis were frequently found impinging on the sympathetic trunk and its rami communicantes at similar frequencies on both sides. The factors governing the characteristic compression of the sympathetic structures in the thorax are the typical development of the osteophytes and the special relations of the sympathetic structures to the vertebral column at the various levels. It is proposed that these observations are useful in understanding certain observed clinical conditions and act an anatomic baseline for research in the future.

Aged↗
PubMed1995

Multiple sources of the impedance cardiogram based on 3-D finite difference human thorax models.

Two 3-D electrical models of the human thorax, each consisting of 216,000 control volumes, were constructed based upon MR images taken at end diastole and end systole. Using the finite difference method, the contributions of various sources to the impedance cardiogram were studied for the traditional band electrode configuration. The contributions were categorized into three areas: 1) the structural changes between end diastole and end systole, 2) the flow-induced blood resistivity changes in major arteries and veins, and 3) the lung resistivity variation due to the lung blood volume change. Based on the models, Zo and delta Z between end diastole and end systole were 24.4 omega and -0.132 omega, as compared with the measurements of 21.8 omega and -0.123 omega made on the same subject from whom the images were taken. Arterial and venous blood resistivity changes caused approximately 57% of the total impedance change. The lung resistivity change and the structural changes contributed 39% and 4%, respectively. The structural changes inside the thorax included the dimensional changes of blood vessels, the blood volume changes of the heart chambers, and heart movement. Although the net impedance change due to the structural changes was relatively small, the individual variation of various factors was large, with significant cancellation occurring. The results suggest that the thoracic impedance cardiographic signal is a mixed representation of many inseparable factors and may not be reliable for the stroke volume calculation. Also, the O-wave, which is clinically observed in various cardiac conditions, may be linked to the diastolic blood flow in the central veins.

Adult↗
PubMed1995

Computational studies of transthoracic and transvenous defibrillation in a detailed 3-D human thorax model.

A method for constructing and solving detailed patient-specific 3-D finite element models of the human thorax is presented for use in defibrillation studies. The method utilizes the patient's own X-ray CT scan and a simplified meshing scheme to quickly and efficiently generate a model typically composed of approximately 400,000 elements. A parameter sensitivity study on one human thorax model to examine the effects of variation in assigned tissue resistivity values, level of anatomical detail included in the model, and number of CT slices used to produce the model is presented. Of the seven tissue types examined, the average left ventricular (LV) myocardial voltage gradient was most sensitive to the values of myocardial and blood resistivity. Incorrectly simplifying the model, for example modeling the heart as a homogeneous structure by ignoring the blood in the chambers, caused the average LV myocardial voltage gradient to increase by 12%. The sensitivity of the model to variations in electrode size and position was also examined. Small changes (< 2.0 cm) in electrode position caused average LV myocardial voltage gradient values to increase by up to 12%. We conclude that patient-specific 3-D finite element modeling of human thoracic electric fields is feasible and may reduce the empiric approach to insertion of implantable defibrillators and improve transthoracic defibrillation techniques.

Computer Simulation↗
PubMed1989

The influence of opening the thorax on defibrillation threshold in canines.

To determine if intraoperative testing is predictive of implantable defibrillator performance postoperatively, we measured sequential pulse defibrillation thresholds (DFTs) in 16 adult canines (28.0 +/- 3.5 kg, mean +/- SD body weight) at the time of epicardial defibrillation electrode implantation. Three epicardial defibrillation electrodes were sutured directly to the anterior, posterior, and left lateral epicardial surfaces of the heart through a left fifth intercostal thoracotomy. The pericardium was sutured closed over the electrodes and DFT was measured first with the thorax open and again after closing all surgical wounds, evacuating the thorax, and reinflating the lungs. Mean +/- SD DFT voltage, current, and impedance (pulse 1), and total delivered energy (both pulses) for the open chest measurements were 321 +/- 87 volts, 4.2 +/- 1.9 amps, 80 +/- 14 ohms and 5.3 +/- 3.7 joules, respectively. The corresponding DFT values for the closed chest measurements were 321 +/- 92 volts, 5.1 +/- 1.9 amps, 64 +/- 10 ohms and 6.1 +/- 3.9 joules, respectively. Paired Student's t-test comparison of open versus closed chest DFT values indicated that there were no significant differences in voltage (P greater than 0.80) or energy (P greater than 0.20), but there were significant differences in both current (P less than 0.01) and impedance (P less than 0.001). It is concluded that despite alterations in impedance and current flow, voltage and energy DFT are not significantly different between open and closed chest animals. This suggests that intraoperative testing of implantable defibrillators is predictive of postoperative performance.

Animals↗
PubMed1966

Observations on temperature distribution in the cardiovascular system, thorax and abdomen of monkeys in relation to environment.

1. Thermo-electric observations of temperature distribution in the ;core' area of monkeys and baboons are reported.2. Temperature gradients were shown to exist in the inferior vena cava, temperatures rising by a mean value of 0.2 degrees C at the entry of the renal veins and again by a further 0.2 degrees C at the level of the hepatic veins.3. Temperatures in the right atrium were on average 0.1 degrees C lower than in the inferior vena cava due to the return of relatively cooler blood from the superior vena cava.4. Net heat exchanges in the thorax were small. Right atrial and aortic blood temperatures were not significantly different and it was concluded that heat losses in the thorax were balanced by heat production in lungs and heart.5. The mean liver temperature was 0.1 degrees C higher than that of the aortic blood irrespective of the environment.6. The mean temperature recorded from the lumen of the jejunum was 0.2 degrees C warmer than the aorta in the ;warm' environment and 0.4 degrees C hotter than the aorta in the ;cool' environment. In both environments intrajejunal temperature was higher than the liver but the differential was increased by exposure to a ;cool' environment.7. Evidence is adduced to suggest that the gastro-intestinal tract in the body at rest is a major heat producer contributing about double the amount of heat generated by the liver.8. It is suggested that blood flow redistribution in the splanchnic area on exposure of the body to cold is the main cause of the change in aortic-jejunal and jejunal-liver differentials. Metabolic factors have, however, not been excluded.

Animals↗
PubMed1986

Alternative RNA splicing generates transcripts encoding a thorax-specific isoform of Drosophila melanogaster myosin heavy chain.

Genomic and cDNA sequencing studies show that transcripts from the muscle myosin heavy-chain (MHC) gene of Drosophila melanogaster are alternatively spliced, producing RNAs that encode at least two MHC isoforms with different C termini. Transcripts encoding an MHC isoform with 27 unique C-terminal amino acids accumulate during both larval and adult muscle differentiation. Transcripts for the second isoform encode one unique C-terminal amino acid and accumulate almost exclusively in pupal and adult thoracic segments, the location of the indirect flight muscles. The 3' splice acceptor site preceding the thorax-specific exon is unusually purine rich and thus may serve as a thorax-specific splicing signal. We suggest that the alternative C termini of these two MHC isoforms control myofilament assembly and may play a role in generating the distinctive myofilament organizations of flight muscle and other muscle types.

Amino Acid Sequence↗
PubMed1991

Developmental lymphatic disorders of the thorax.

Developmental disorders that involve the lymphatic channels of the thorax, although rare, are important and must be distinguished from the more common causes of chest masses or diffuse lung disease. There are four major types of developmental lymphatic disorders that affect the thorax: lymphangiectasis, characterized by congenital anomalous dilatation of pulmonary lymph vessels; localized lymphangioma, a rare and benign, usually cystic, lesion characterized by masslike proliferation of lymph vessels; diffuse lymphangioma, a proliferation of vascular, mainly lymphatic, spaces in which visceral and skeletal involvement are common; and lymphangioleiomyoma, which involves a haphazard proliferation of smooth muscle in the lungs and dilatation of lymphatic spaces. These characteristic findings can be seen with radiographic studies as well as with histologic evaluation. The discovery of one of these lymphatic disorders may prompt an investigation for associated congenital anomalies, including Noonan syndrome, asplenia, Gorham syndrome, and tuberous sclerosis.

Child↗
PubMed1993

Embolization in the treatment of acquired and congenital abnormalities of the heart and thorax.

Embolization is well suited to the treatment of a range of vascular abnormalities found only in the thorax. This includes congenital arteriovenous fistulas or malformations affecting the chest wall and the pulmonary and coronary arteries. Acquired bronchial artery anomalies and some types of congenital heart disease are also suitable for embolization. Embolization in the thorax presents problems related to the need to work through or in the heart or to the risk to important branches of the intrathoracic aorta, such as the carotid arteries. The choice and use of different catheters and embolic materials for thoracic embolization depend on the nature and configuration of the lesion and the experience of the operator. Selection must also be based on consideration of the risk of inadvertent embolization of adjacent structures such as the spinal arteries. With embolization experience elsewhere in the body and an understanding of the particular problems presented by thoracic embolization, various important, even if uncommon, conditions can be effectively treated.

Arteriovenous Malformations↗
PubMedDate not supplied

Vascular emergencies of the thorax after blunt and iatrogenic trauma: multi-detector row CT and three-dimensional imaging.

Multi-detector row computed tomographic (CT) angiography is an effective modality for vascular imaging in the thorax. It allows acquisition of high-resolution data sets during a single breath hold, making it the preferred method for evaluation of patients with acute vascular disease. In contrast to conventional angiography, multirow CT angiography not only depicts the vessels but also allows assessment of adjacent structures. Multirow CT angiography with two- and three-dimensional reformation can be used to diagnose vascular emergencies of the thorax after blunt and iatrogenic trauma. These include incomplete and complete aortic rupture; traumatic aortic dissection; arterial dissection and rupture after minor trauma in patients with Ehlers-Danlos syndrome; traumatic intramural hematoma; pseudoaneurysm after endovascular repair; injuries due to Swan-Ganz catheters; complications of central venous cannulation, pacemaker implantation, and percutaneous pericardial drainage; and foreign-body embolism. The diagnoses can be established with multirow CT angiography in the emergency department. Thus, the time to diagnosis can be considerably decreased by obviating conventional angiography. Knowledge of the CT findings in various vascular conditions is essential to make use of multirow CT angiography in combination with two- and three-dimensional reformation as an efficient and accurate diagnostic tool in emergency radiology.

Adult↗
PubMed2001

Virtual tools for imaging of the thorax.

Helical computed tomography (HCT) allows for volume acquisition of the entire thorax during a single apnoea. Combination of HCT acquisition with synchronous vascular enhancement gives rise to HCT angiography (HCTA). In the last decade, HCT and HCTA have revolutionized the diagnosis of thoracic diseases, modifying many diagnostic algorithms. Because HCT provides for a true volume acquisition free of respiratory misregistration, three-dimensional (3D) rendering techniques can be applied to HCT acquisitions. As these 3D rendering techniques present the HCT information in a different format to the conventional transaxial CT slices, they can be summarized as virtual tools. The purpose of this review is to give the readers the most important technical aspects of virtual tools, to report their application to the thorax, to answer clinical and scientific questions, and to stress their importance for patient management, clinical decision making, and research.

Humans↗