Chest radiograph - Wikipedia. A chest radiograph, colloquially called a chest X- ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in medicine. Like all methods of radiography, chest radiography employs ionizing radiation in the form of X- rays to generate images of the chest. The mean radiation dose to an adult from a chest radiograph is around 0. Sv (2 mrem) for a front view (PA or posterior- anterior) and 0. Sv (8 mrem) for a side view (LL or latero- lateral).[1] Together, this corresponds to a background radiation equivalent time of about 1. Medical uses[edit]. A chest X- ray showing a very prominent wedge- shape area of airspace consolidation in the right lung characteristic of acute bacterial lobar pneumonia. Conditions commonly identified by chest radiography. Chest radiographs are used to diagnose many conditions involving the chest wall, including its bones, and also structures contained within the thoracic cavity including the lungs, heart, and great vessels. ![]() Pneumonia and congestive heart failure are very commonly diagnosed by chest radiograph.Chest radiographs are used to screen for job- related lung disease in industries such as mining where workers are exposed to dust.[3]For some conditions of the chest, radiography is good for screening but poor for diagnosis.When a condition is suspected based on chest radiography, additional imaging of the chest can be obtained to definitively diagnose the condition or to provide evidence in favor of the diagnosis suggested by initial chest radiography.Unless a fractured rib is suspected of being displaced, and therefore likely to cause damage to the lungs and other tissue structures, x- ray of the chest is not necessary as it will not alter patient management. Stone Roses Discography Torrent Mp3 Search . The main regions where a chest X- ray may identify problems may be summarized as ABCDEF by their first letters: [4]Airways, including hilar adenopathy or enlargement. Breast shadows. Bones, e. Cardiac silhouette, detecting cardiac enlargement. Costophrenic angles, including pleural effusions. Diaphragm, e. g. evidence of free air, indicative of perforation of an abdominal viscus. Edges, e. g. apices for fibrosis, pneumothorax, pleural thickening or plaques. Extrathoracic tissues. Fields (lung parenchyma), being evidence of alveolar flooding. Failure, e. g. alveolar air space disease with prominent vascularity with or without pleural effusions. Positioning for a PA chest x- ray. Normal lateral chest radiograph. Different views (also known as projections) of the chest can be obtained by changing the relative orientation of the body and the direction of the x- ray beam. The most common views are posteroanterior, anteroposterior, and lateral. In an posteroanterior (PA) view, the x- ray source is positioned so that the x- ray beam enters through the posterior (back) aspect of the chest, and exits out of the anterior (front) aspect where the beam is detected. To obtain this view, the patient stands facing a flat surface behind which is an x- ray detector. A radiation source is positioned behind the patient at a standard distance (most often 6 feet, 1,8m), and the x- ray beam is fired toward the patient. In anteroposterior (AP) views, the positions of the x- ray source and detector are reversed: the x- ray beam enters through the anterior aspect and exits through the posterior aspect of the chest. Looking for books on radiology?Check our section of free e-books and guides on radiology now!This page contains list of freely available E-books, Online Textbooks.Most patients begin with a chest x-ray for this purpose; however, in severe cases, or in patients where initial treatment methods are not producing positive results.X-ray photons carry enough energy to ionize atoms and disrupt molecular bonds.This makes it a type of ionizing radiation, and therefore harmful to living tissue. Best Consignment Shop Software Help . Musculoskeletal chest wall pain | RACGP.In one general practice sample, costochondritis, also known as costosternal syndrome and anterior chest wall syndrome, was. AP chest x- rays are harder to read than PA x- rays and are therefore generally reserved for situations where it is difficult for the patient to get an ordinary chest x- ray, such as when the patient is bedridden. In this situation, mobile X- ray equipment is used to obtain a lying down chest x- ray (known as a "supine film"). As a result, most supine films are also AP. Lateral views of the chest are obtained in a similar fashion as the posteroanterior views, except in the lateral view, the patient stands with both arms raised and the left side of the chest pressed against a flat surface. Typical views[edit]Required projections can vary by country and hospital, typically an erect postero- anterior (PA) projection is first preference, if this is not possible then an antero- posterior view will be taken. Further imaging depends on local protocols which is dependent on the hospital protocols, the availability of other imaging modalities and the preference of the image interpreter. In the UK, the standard chest radiography protocol is to take an erect posteroanterior view only, and a lateral one only on request by a radiologist [5] In the US, chest radiography includes a PA and Lateral with the patient standing or sitting up. Special projections include an AP in cases where the image needs to be obtained stat and with a portable device, particularly when a patient cannot be safely positioned upright. Lateral decubitus may be used for visualization of air- fluid levels if an upright image cannot be obtained. Anteroposterior (AP) Axial Lordotic projects the clavicles above the lung fields, allowing better visualization of the apices (which is extremely useful when looking for evidence of primary tuberculosis)Additional views[edit]Decubitus – taken while the patient is lying down, typically on his side. In effusions, the fluid layers out (by comparison to an up- right view, when it often accumulates in the costophrenic angles). Lordotic view – used to visualize the apex of the lung, to pick up abnormalities such as a Pancoast tumour. Expiratory view – helpful for the diagnosis of pneumothorax. Oblique view – useful for the visualization of the ribs and sternum. Although it's necessary to do the appropriate adaptations to the x- ray dosage to be used. Torrent Noah And The Whale Discography Prince more. Landmarks[edit]. A chest radiograph with the angle parts of the ribs and some other landmarks labeled. In the average person, the diaphragm should be intersected by the 5th to 7th anterior ribs at the mid- clavicular line, and 9 to 1. PA inspiratory film. An increase in the number of viewable ribs implies hyperinflation, as can occur, for example, with obstructive lung disease or foreign body aspiration. A decrease implies hypoventilation, as can occur with restrictive lung disease, pleural effusions or atelectasis. Underexpansion can also cause interstitial markings due to parenchymal crowding, which can mimic the appearance of interstitial lung disease. Enlargement of the right descending pulmonary artery can indirectly reflect changes of pulmonary hypertension, with a size greater than 1. Appropriate penetration of the film can be assessed by faint visualization of the thoracic spines and lung markings behind the heart. The right diaphragm is usually higher than the left, with the liver being situated beneath it in the abdomen. The minor fissure can sometimes be seen on the right as a thin horizontal line at the level of the fifth or sixth rib. Splaying of the carina can also suggest a tumor or process in the middle mediastinum or enlargement of the left atrium, with a normal angle of approximately 6. The right paratracheal stripe is also important to assess, as it can reflect a process in the posterior mediastinum, in particular the spine or paraspinal soft tissues; normally it should measure 3 mm or less. The left paratracheal stripe is more variable, and only seen in 2. Localization of lesions or inflammatory and infectious processes can be difficult to discern on chest radiograph, but can be inferenced by silhouetting and the hilum overlay sign with adjacent structures. If either hemidiaphragm is blurred, for example, it suggests the lesion to be from the corresponding lower lobe. If the right heart border is blurred, than the pathology is likely in the right middle lobe, though a cavum deformity can also blur the right heard border due to indentation of the adjacent sternum. If the left heart border is blurred, it implies a process at the lingula.[8]Abnormalities[edit]A pulmonary nodule is a discrete opacity in the lung which may be caused by: There are a number of features that are helpful in suggesting the diagnosis: rate of growth. Doubling time of less than one month: sarcoma/infection/infarction/vascular. Doubling time of six to 1. Doubling time of more than 2. If the nodules are multiple, the differential is then smaller: Cavities[edit]A cavity is a walled hollow structure within the lungs. Diagnosis is aided by noting: wall thicknesswall outlinechanges in the surrounding lung. X- ray - Wikipedia. This article is about the nature, production, and uses of the radiation. For the method of imaging, see Radiography. For imaging in a medical context, see Radiology. For other meanings, see X- ray (disambiguation). X- radiation (composed of X- rays) is a form of electromagnetic radiation. Most X- rays have a wavelength ranging from 0. Hz to 3×1. 01. 9 Hz) and energies in the range 1. V to 1. 00 ke. V. X- ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X- radiation is referred to with terms meaning Röntgen radiation, after the German scientist Wilhelm Röntgen,[1] who usually is credited as its discoverer, and who had named it X- radiation to signify an unknown type of radiation.[2] Spelling of X- ray(s) in the English language includes the variants x- ray(s), xray(s), and X ray(s).[3]Energy ranges[edit]Soft and hard X- rays[edit]X- rays with high photon energies (above 5–1. V, below 0. 2–0. 1 nm wavelength) are called hard X- rays, while those with lower energy are called soft X- rays.[4] Due to their penetrating ability, hard X- rays are widely used to image the inside of objects, e. The term X- ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. Since the wavelengths of hard X- rays are similar to the size of atoms they are also useful for determining crystal structures by X- ray crystallography. By contrast, soft X- rays are easily absorbed in air; the attenuation length of 6. V (~2 nm) X- rays in water is less than 1 micrometer.[5]Gamma rays[edit]There is no consensus for a definition distinguishing between X- rays and gamma rays. One common practice is to distinguish between the two types of radiation based on their source: X- rays are emitted by electrons, while gamma rays are emitted by the atomic nucleus.[6][7][8][9] This definition has several problems: other processes also can generate these high- energy photons, or sometimes the method of generation is not known. One common alternative is to distinguish X- and gamma radiation on the basis of wavelength (or, equivalently, frequency or photon energy), with radiation shorter than some arbitrary wavelength, such as 1. This criterion assigns a photon to an unambiguous category, but is only possible if wavelength is known. Some measurement techniques do not distinguish between detected wavelengths.) However, these two definitions often coincide since the electromagnetic radiation emitted by X- ray tubes generally has a longer wavelength and lower photon energy than the radiation emitted by radioactivenuclei.[6] Occasionally, one term or the other is used in specific contexts due to historical precedent, based on measurement (detection) technique, or based on their intended use rather than their wavelength or source. Thus, gamma- rays generated for medical and industrial uses, for example radiotherapy, in the ranges of 6–2. Me. V, can in this context also be referred to as X- rays.[citation needed]Properties[edit]. Ionizing radiation hazard symbol. X- ray photons carry enough energy to ionize atoms and disrupt molecular bonds. This makes it a type of ionizing radiation, and therefore harmful to living tissue. A very high radiation dose over a short period of time causes radiation sickness, while lower doses can give an increased risk of radiation- induced cancer. In medical imaging this increased cancer risk is generally greatly outweighed by the benefits of the examination. The ionizing capability of X- rays can be utilized in cancer treatment to kill malignantcells using radiation therapy. It is also used for material characterization using X- ray spectroscopy. Attenuation length of X- rays in water showing the oxygen absorption edge at 5. V, the energy−3 dependence of photoabsorption, as well as a leveling off at higher photon energies due to Compton scattering. The attenuation length is about four orders of magnitude longer for hard X- rays (right half) compared to soft X- rays (left half). Hard X- rays can traverse relatively thick objects without being much absorbed or scattered. For this reason, X- rays are widely used to image the inside of visually opaque objects. The most often seen applications are in medical radiography and airport security scanners, but similar techniques are also important in industry (e. CT scanning) and research (e. CT). The penetration depth varies with several orders of magnitude over the X- ray spectrum. This allows the photon energy to be adjusted for the application so as to give sufficient transmission through the object and at the same time good contrast in the image. X- rays have much shorter wavelengths than visible light, which makes it possible to probe structures much smaller than can be seen using a normal microscope. This property is used in X- ray microscopy to acquire high resolution images, and also in X- ray crystallography to determine the positions of atoms in crystals. Interaction with matter[edit]X- rays interact with matter in three main ways, through photoabsorption, Compton scattering, and Rayleigh scattering. The strength of these interactions depends on the energy of the X- rays and the elemental composition of the material, but not much on chemical properties, since the X- ray photon energy is much higher than chemical binding energies. Photoabsorption or photoelectric absorption is the dominant interaction mechanism in the soft X- ray regime and for the lower hard X- ray energies. At higher energies, Compton scattering dominates. Photoelectric absorption[edit]The probability of a photoelectric absorption per unit mass is approximately proportional to Z3/E3, where Z is the atomic number and E is the energy of the incident photon.[1. This rule is not valid close to inner shell electron binding energies where there are abrupt changes in interaction probability, so called absorption edges. However, the general trend of high absorption coefficients and thus short penetration depths for low photon energies and high atomic numbers is very strong. For soft tissue, photoabsorption dominates up to about 2. V photon energy where Compton scattering takes over. For higher atomic number substances this limit is higher. The high amount of calcium (Z=2. A photoabsorbed photon transfers all its energy to the electron with which it interacts, thus ionizing the atom to which the electron was bound and producing a photoelectron that is likely to ionize more atoms in its path. An outer electron will fill the vacant electron position and produce either a characteristic photon[clarification needed] or an Auger electron. These effects can be used for elemental detection through X- ray spectroscopy or Auger electron spectroscopy. Compton scattering[edit]Compton scattering is the predominant interaction between X- rays and soft tissue in medical imaging.[1. Compton scattering is an inelastic scattering of the X- ray photon by an outer shell electron. Part of the energy of the photon is transferred to the scattering electron, thereby ionizing the atom and increasing the wavelength of the X- ray. The scattered photon can go in any direction, but a direction similar to the original direction is more likely, especially for high- energy X- rays. The probability for different scattering angles are described by the Klein–Nishina formula. The transferred energy can be directly obtained from the scattering angle from the conservation of energy and momentum. Rayleigh scattering[edit]Rayleigh scattering is the dominant elastic scattering mechanism in the X- ray regime.[1. Inelastic forward scattering gives rise to the refractive index, which for X- rays is only slightly below 1.[1. Production[edit]Whenever charged particles (electrons or ions) of sufficient energy hit a material, X- rays are produced. Production by electrons[edit]Characteristic X- ray emission lines for some common anode materials.[1. Anodematerial. Atomicnumber. Photon energy [ke. V]Wavelength [nm]Kα1. Kβ1. Kα1. Kβ1. W7. Mo. 42. 17. 5. 19. Cu. 29. 8. 0. 58. Ag. 47. 22. 2. 24. Ga. 31. 9. 2. 51. In. 49. 24. 2. 27. X- rays can be generated by an X- ray tube, a vacuum tube that uses a high voltage to accelerate the electrons released by a hot cathode to a high velocity. The high velocity electrons collide with a metal target, the anode, creating the X- rays.[1. In medical X- ray tubes the target is usually tungsten or a more crack- resistant alloy of rhenium (5%) and tungsten (9. X- rays are needed as in mammography.
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