Search results
Results from the WOW.Com Content Network
The roentgen or röntgen (/ ˈ r ɛ n t ɡ ə n,-dʒ ə n, ˈ r ʌ n t-/; [2] symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays, and is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air (statcoulomb per kilogram).
A ventilation/perfusion lung scan, also called a V/Q lung scan, or ventilation/perfusion scintigraphy, is a type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient's lungs, [1] [2] in order to determine the ventilation/perfusion ratio.
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").
The alveolar oxygen partial pressure is lower than the atmospheric O 2 partial pressure for two reasons. Firstly, as the air enters the lungs, it is humidified by the upper airway and thus the partial pressure of water vapour (47 mmHg) reduces the oxygen partial pressure to about 150 mmHg.
is the partial pressure of oxygen in the systemic veins (where it can actually be measured). Thus, the higher the diffusing capacity , the more gas will be transferred into the lung per unit time for a given gradient in partial pressure (or concentration) of the gas. Since it can be possible to know the alveolar oxygen concentration and the ...
A chest X-ray showing right sided (seen on the left of the picture) pulmonary contusion associated with rib fractures and subcutaneous emphysema. Chest X-ray is the most common method used for diagnosis, [37] and may be used to confirm a diagnosis already made using clinical signs. [20] Consolidated areas appear white on an X-ray film. [42]
Chest x-ray is the first test done to confirm an excess of pleural fluid. The lateral upright chest x-ray should be examined when a pleural effusion is suspected. In an upright x-ray, 75 mL of fluid blunts the posterior costophrenic angle. Blunting of the lateral costophrenic angle usually requires about 175 mL but may take as much as 500 mL.
An X-ray generator generally contains an X-ray tube to produce the X-rays. Possibly, radioisotopes can also be used to generate X-rays. [1]An X-ray tube is a simple vacuum tube that contains a cathode, which directs a stream of electrons into a vacuum, and an anode, which collects the electrons and is made of tungsten to evacuate the heat generated by the collision.