X-ray Attenuation Mechanisms

They lose some or all of their energy to the atoms or molecules in their way.

Attenuation

Different materials attenuate X-rays to a different extent.

<p>They are more likely to be absorbed.</p> Signup and view all the answers

<p>The images are easier to process, store, and transfer.</p> Signup and view all the answers

<p>It decreases exponentially.</p> Signup and view all the answers

<p>It will quarter.</p> Signup and view all the answers

<p>It allows for the creation of contrasted images of the body, such as bones and soft tissues.</p> Signup and view all the answers

<p>To generate a cascade of electrons, amplifying the signal.</p> Signup and view all the answers

<p>By placing a ring of gamma cameras around the patient and detecting the emission sites of the gamma photons.</p> Signup and view all the answers

<p>A pair of gamma photons are produced, emitted in opposite directions.</p> Signup and view all the answers

<p>By recording the arrival times of the gamma photons and using the known speed of the photons.</p> Signup and view all the answers

<p>To detect the emission site of the gamma photons.</p> Signup and view all the answers

<p>Because it is a ring of gamma cameras, allowing for the detection of gamma photons from multiple angles.</p> Signup and view all the answers

<p>The annihilation event occurs soon after the beta emission.</p> Signup and view all the answers

<p>A 3D model of the tracer locations.</p> Signup and view all the answers

<p>They take a significantly longer time and expose the patient to a far greater dose of ionising radiation.</p> Signup and view all the answers

<p>To detect the X-ray beam intensity.</p> Signup and view all the answers

<p>The X-ray tube and detectors rotate about the patient and move up and down their length, and images of each slice are stitched together.</p> Signup and view all the answers

<p>To collect in particular locations in the body and aid in diagnosis and therapy.</p> Signup and view all the answers

<p>Because they are least ionising and most penetrative.</p> Signup and view all the answers

<p>They are more ionising and would cause significant damage.</p> Signup and view all the answers

<p>The information is processed to reconstruct the tissues that the beam has passed through.</p> Signup and view all the answers

<p>Inside the patient's body.</p> Signup and view all the answers

<p>To locate areas in the body with high rates of respiration, such as cancerous tumors or active parts of the brain.</p> Signup and view all the answers

<p>It is non-ionising and non-invasive.</p> Signup and view all the answers

<p>20 kHz</p> Signup and view all the answers

<p>From measurements of the waves after they have been in contact with the medium.</p> Signup and view all the answers

<p>To produce an electrical signal from the sound waves.</p> Signup and view all the answers

<p>It requires tracers to be synthesised on-site.</p> Signup and view all the answers

<p>It can accurately demonstrate organ function and observe the effects of various medications.</p> Signup and view all the answers

<p>5 MHz</p> Signup and view all the answers

<p>Most of the wave energy is reflected.</p> Signup and view all the answers

<p>To maximize the transmission of the ultrasound into the patient and minimize reflection.</p> Signup and view all the answers

<p>The change in frequency of a wave when it is reflected or produced by a moving source.</p> Signup and view all the answers

<p>By using ultrasound waves to detect the reflected waves from moving blood cells.</p> Signup and view all the answers

<p>Due to the differences in the impedances of the two media.</p> Signup and view all the answers

<p>It reflects the ultrasound wave back to the transducer.</p> Signup and view all the answers

<p>It provides a non-invasive technique to measure the speed of blood flow.</p> Signup and view all the answers

<p>Most of the wave energy is transmitted.</p> Signup and view all the answers