Diagnostic Imaging Flashcards
Diagnostic imaging types?
Diagnostic imaging types?
.Radiography
.Ultrasound
.Nuclear scintigraphy (gamma scan)
.Endoscopy
.Computed tomography (CT/ CAT scan)
.Magnetic resonance imaging (MRI)
X-rays?
X-rays?
.Are a type of radiation called electromagnetic waves. The x-ray will show different shades of B&W because different tissues absorb different amounts of radiation.
.Have a short wave-length and high frequency. They are part of the electromagnetic spectrum; this is composed of energy waves.
.Used to detect dislocations & fractures of bones , cancers, pneumonia, foreign bodies, organs diseased ect.
Ultrasound?
Ultrasound?
.Uses high-frequency sound waves that are sent into the body by a transducer and when reflected from interfaces between the tissues are collected by the transducer and an image forms on a computer screen.
.Used to demonstrate soft tissues, not always visible on radiographs e.g. abdomen, tendons, ligaments and soft tissue masses.
Magnetic resonance imaging?
Magnetic resonance imaging?
.Produces images of bodily organs by measuring the response of the atomic nuclei of body tissues to high-frequency radiowaves when placed in a strong magnetic field.
.Does not use ionising radiation. Is used to produce an image by mapping the locations of the protons of the body tissues.
.Ideal for CNS & spinal column & soft tissues within joints.
.Patient is exposed to a large magnetic field. The magnet has a strength of between 0.2 - 2 telsa(T)
Nuclear scrintigraphy (gamma scan)?
Nuclear scrintigraphy?
.Radioisotopes attached to drugs that travel to a specific organ or tissue are taken internally.
.Will demonstrate the function of a tissue or organ and will show where a problem is but no exact diagnosis.
.Mainly used for cats and horses
Computed tomography?
Computed tomography?
.Computerised x-ray imaging procedure in which a narrow of x-rays is aimed at a patient and quickly rotated around the body (creates slides of the body).
.Uses a x-ray tube mounted opposite a detector, the tube emits x-rays in a fan shape that passes through the patient to reach the detector. The x-ray tube and the detector move around the patient (3D scan).
.Ideal for skeletal & CNS and diagnoses internal organ injuries in 3D. They are an advanced x-ray device.
Every element is?
Every element is?
.Made up of atoms. These atoms contain nucleus, composed of neutrons and protons, surrounded by orbiting electrons
.Protons - always positively charged
.Neutrons - neutral & have no charge
.Orbiting electrons - negative and orbit the necleus in shells.
Hertz (Hz)?
Hertz (Hz)?
.Frequency measurement
.1 Hz is equal to 1 cycle per second
Inverse square law?
Inverse square law?
.The further away from the x-ray tube you can get, the lower the intensity of x-rays reaching the body and causing damage.
Electric current?
Electric current?
.Formed when electrons flow through a conductor.
.If the electrons flow in one direction, then a direct current (DC) is generated and if in alternating directions will be an alternating current (AC).
Cathode?
Cathode?
.The negative part of the x-ray tube and is made up of filament and focusing cup.
Anode?
Anode?
.Is the positive part of the x-ray tube.
X-ray tube?
X-ray tube?
.Produces the x-ray and is composed of a pyrex tube surrounding the anode and cathode.
X-ray beam?
X-ray beam?
.May be absorbed by the tissues of the patient.
.Has minimal absorption but if scattered will be absorbed more.
Milliamperage?
Milliamperage?
.Higher the milliamperage, the higher the heat and the more electrons produced.
.Heating releases electrons from the surface of the filament wire. The electrons collect in the focusing cup.