Introduction to Radiology - imaging modalities Study Guide Questions Fully Solved.

What are the imaging modalities that use ionizing radiation? - correct answer 1. Radiographs (x-rays, conventional films, plain films) 2. Computed tomography (CT) 3. Nuclear medicine (NM) What are the imaging modalities that do not use ionizing radiation? - correct answer 1. Magnetic resonance imaging (uses magnet and radio waves) 2. ultrasound (uses sound waves) The birth of radiology started with which imaging modality? - correct answer The x-ray On November 8th 1895, WilhelmConrad Roentgen discover the _____________. Why did he call it this? - correct answer x-ray He termed this new invisible ray, X-ray (X = unknown) Receive 1st Nobel prize in physics in 1901 The X-ray hit widespread use for medical imaging by the year _________ - correct answer 1913 T or F: conventions radiographs/ plain films use an added contract material - correct answer False: images produced through the use of ionizing radiation but without added contrast material i.e. Barium or iodine Conventional radiographs The X-rays pass through the patient and are detected on the other side by ___________ or __________ - correct answer Films or digital detector The images from conventional radiographs are named with consideration of what? - correct answer The direction of x-ray beams What are some common radiographic projections? - correct answer The radiographs are named with consideration of the direction of X-ray beams, common radiographic projections are 1. Anterior-posterior (AP) - the x-rays go in the front and come out the back 2. Posterior-anterior (PA) - Come through back first, then anterior, then hit the detector (often the orientation in the thorax) 3. Lateral X-rays are absorbed based on what as they pass through the body? - correct answer Based upon density of the tissue. (This difference in absorption produces an image) A totally _________ or _________ material will absorb all the X-rays, how does this show up on the image on the detector and what is it termed on that image? - correct answer Opaque (= not able to be seen through) or dense material will absorb all the X-rays, allowing none to pass through, thus creating a WHITE image. This is referred to as radiopaque or radiodense *there will be a question on the exam concerning radiopaque or radiodense along with all the other similar terminologies from all the different modialities, she hinted hard core on this one When a less dense tissue is between the source and the film in a conventional radiograph, what happens to the x-rays and how does this correspond to the image detected? - correct answer When a less dense tissue is between the source and the film, more X-rays strike the film, leading to a BLACK image. This is referred to as radiolucent Intermediate degrees of density give rise to shade of ________ in a conventional radiograph image - correct answer Gray Radiopaque (or radiodense) = ____________ tissue; _________ image Radiolucent = ___________ tissue; __________ image - correct answer Radiopaque = opaque or dense tissue; white image Radiolucent = less dense tissue; black image An X-ray through air would generate a completely ___________ image - correct answer Radiolucent - black (because the X-rays are not absorbed most of the x-rays get through and can hit the detector causing it to be black or dark image known as radiolucent) What would happen if we tried to pass x-rays through lead, what wold be the resulting image? - correct answer The lead would absorb the x-rays so that only a little bit gets through to the film, it generates a white image where the lead is on the film and in the shape of the piece of the lead, this white image is referred to as Radiopaque/ Radiodense 5 basic densities on radiographs Bone, air, metal, fat, fluid, and soft tissue. Give these tissue in order from radiolucent to radiopaque - correct answer Radiolucent -- radiopaque 1. Air -black 2. Fat - dark gray 3. Soft tissue and fluid - gray 4. Bone light gray 5. Metal - white Air is most radiolucent and metal is most radiopaque She emphasized that it is both soft tissue AND fluid that is medium and is a gray color ________-absorbs the least x-ray and appears "blackest" on conventional radiographs - correct answer Air _______-gray somewhat darker (blacker) than soft tissue - correct answer Fat T or F: both fluid (ex: blood) and soft tissue (ex: muscle) have the same densities on conventional radiographs - correct answer True: they have a medium gray level _________-the most dense naturally occurring material (ex: bones) absorbs most x-rays - correct answer Calcium (because absorbs most x-rays, it generates a more radiopaque image of the bone on a conventional radiograph) ___________-usually absorbs all X-rays and appears the "whitest" (most radiopaque) - correct answer Metal (ex: bullets, barium) T or F: you can get a complete view with just one view (one plane) of image taken with conventional radiograph. - correct answer FALSE!! She emphasized this several times that one view = NO view Why does one view = no view in radiography? - correct answer Radiographs are 2D projections of a 3D patient Radiographs flatten everything (everything is superimposed on one another) Multiple views are needed What are the advantages and disadvantages to plain films? - correct answer Advantages 1. Fast 2. These images are relatively inexpensive to produce 3. Can be obtained almost anywhere using portable or mobile machines 4. Are still the most widely obtained imaging studies Disadvantages 1. Utilizes ionizing radiation 2. Soft tissue is hard to visualize or can't be visualized at all 3. Not usually recommended for pregnant women except in an emergency What is fluoroscopy? - correct answer Continuous beam of x-rays passes through the patient to