1.
Tungsten is used as the target material on the tube's anode because it has a _____ atomic number and a _____ melting point.
Correct Answer
D. High, high
Explanation
Tungsten's high atomic number means it has a high melting point of approximately 3400 degrees Celsius.
2.
Using _____ reconstruction filter would decrease the appearance of noise in a CT image.1. no2. a smooth3. a sharp
Correct Answer
B. 2 only
Explanation
A smooth filter is used for visualizing subtle differences in contrast by minimizing the appearance of noise in an image.
3.
Which of the following are possible results of partial voluming?1. improvement in resolution2. misleading CT numbers3. decreased sharpness of edges
Correct Answer
D. 2 & 3
Explanation
Partial voluming occurs when more than one tissue is contained within a voxel and the attenuation values of the tissues are averaged together to determine the final CT number. It can blur edges between tissues if the edges fall within a voxel.
4.
Following the HIPAA guidelines, you may give a patient's medical information to another employee:
Correct Answer
B. Only if it is needed to do their job
Explanation
According to HIPAA guidelines, a patient's medical information can be shared with another employee only if it is necessary for them to perform their job duties. This ensures that patient confidentiality is maintained and information is only disclosed on a need-to-know basis. Sharing medical information for any other reasons, such as joking about the patient, would be a violation of HIPAA regulations.
5.
Which of the following is a result of injecting a hypertonic solution into the vascular space?
Correct Answer
D. There is a net movement of water into the vascular space.
Explanation
The net movement of water into the vascular space occurs by the process of osmosis.
6.
Which of the following is NOT a location where one would expect to find cerebral spinal fluid?1. fourth ventricle of the brain2. subarachnoid space3. subdural space
Correct Answer
C. 3 only
Explanation
Cerebrospinal fluid is produced in the choroid plexus which originates in the ventricles of the brain. The CSF circulates outward through the fourth ventricle of the brain into the subarachnoid space around the brain and spinal cord. CSF is not found in the subdural space which is situated between the dura mater and the arachnoid.
7.
Which of the following is a technique used to minimize artifacts from patient motion in exams of the chest?1. patient immobilization devices2. suspended respiration3. shortened scan time
Correct Answer
D. 1,2 & 3
Explanation
Patient motion during exams of the chest can cause artifacts in the resulting images, making it difficult to interpret the findings accurately. To minimize these artifacts, several techniques can be used. Patient immobilization devices, such as straps or foam pads, can help restrict movement and keep the patient still during the exam. Suspended respiration involves instructing the patient to hold their breath at a specific point during the scan, reducing motion caused by breathing. Shortened scan time is another technique that can be employed, as a shorter scan duration reduces the likelihood of motion artifacts. Therefore, all three options - patient immobilization devices, suspended respiration, and shortened scan time - are valid techniques to minimize artifacts from patient motion in chest exams.
8.
Which of the following may reduce the out-of-field artifact?
Correct Answer
B. Increasing the scan field-of-view
Explanation
The out-of-field artifact is caused by anatomy extending beyond the scan field-of-view. Increasing the scan field-of-view will reduce this by decreasing the likelihood of anatomy extending beyond its boundaries.
9.
A cone beam artifact may look like stars:
Correct Answer
C. Coming from structures around the edge of the image
Explanation
Cone beam artifacts occur in cone beam computed tomography (CBCT) scans and can appear as streaks or star-shaped patterns. These artifacts are caused by the cone-shaped beam used in CBCT, which can lead to inaccuracies in the image reconstruction process. In this case, the artifact is specifically mentioned to be coming from structures around the edge of the image. This suggests that the artifact is originating from the outer boundaries of the scanned object, resulting in streaks or star-like patterns that extend towards the center of the image.
10.
Which the following is NOT contained within the mediastinum?
Correct Answer
A. Lungs
Explanation
The mediastinum includes the heart, the origins of the great vessels, the trachea, the bronchi, the esophagus, the thymus, lymph nodes, the thoracic duct, and the phrenic and vagus nerves.
11.
Which scanning plane is best for evaluating the anatomical relationship between the pituitary and the sella turcica?
Correct Answer
A. Coronal
Explanation
Coronal images should be either directly acquired or reconstructed from the helical images using thin slices of about 1-2mm and should extend from the anterior clinoid through the dorsum sella.
12.
Which of the following is a common patient reaction to IV contrast media?1. warmth at the injection site2. headache3. nausea
Correct Answer
D. 1,2 & 3
Explanation
A common patient reaction to IV contrast media includes warmth at the injection site, headache, and nausea. These symptoms are often experienced by patients after receiving IV contrast media.
13.
If the mA of a 2 second brain scan is doubled and all other parameters are not changed, the dose is:
Correct Answer
A. Doubled
Explanation
If the mA (milliamperage) of a 2-second brain scan is doubled and all other parameters remain unchanged, the dose of radiation is doubled. This is because the mA is directly proportional to the dose of radiation. When the mA is doubled, the amount of radiation delivered to the brain is also doubled, resulting in an increased dose.
14.
Which of the following has the highest patient dose assuming all other parameters are the same?
Correct Answer
B. MA = 150, rotation time = 3 seconds
Explanation
The patient dose in computed tomography (CT) is determined by the product of the tube current (mA) and the exposure time (rotation time). In this case, all other parameters are the same except for the mA and rotation time. The highest patient dose will occur when the product of mA and rotation time is the highest. In this case, the product of mA = 150 and rotation time = 3 seconds is the highest among the given options, resulting in the highest patient dose.
15.
A _____ scan uses only a single projection.1. conventional, or serial2. helical3. localizer
Correct Answer
C. 3 only
Explanation
A localizer scan uses only a single projection. This type of scan is typically used to locate a specific area or region of interest within the body. It provides a localized image rather than a full scan of the entire body. Conventional or serial scans involve multiple projections, while helical scans involve continuous rotation of the scanner during the scan. Therefore, the correct answer is 3 only, as only the localizer scan uses a single projection.
16.
______ scanner design was the first to acquire four slices in a single rotation.
Correct Answer
D. Multi-row detector
Explanation
Multi-row detector scanner design was the first to acquire four slices in a single rotation. This design incorporates multiple rows of detectors in the scanner, allowing for the simultaneous acquisition of multiple slices of data during each rotation. This advancement in technology increased the efficiency and speed of scanning, enabling the acquisition of four slices in a single rotation. This development marked a significant improvement in CT scanning capabilities and paved the way for further advancements in the field.
17.
The enormous heat that builds up in the CT tube is caused by the:
Correct Answer
C. Collision of the electron beam with the tungsten target on the tube anode
Explanation
The correct answer is the collision of the electron beam with the tungsten target on the tube anode. When the electron beam strikes the tungsten target, it transfers its kinetic energy to the target, causing it to heat up. This heat is then dissipated through the CT tube, resulting in the enormous heat buildup.
18.
Which of the following statements is FALSE regarding 3D SSD?
Correct Answer
A. The volume data, from which the 3D SSD is generated, is created by combining transverse, sagittal, and coronal reconstructions
Explanation
The volume data, from which the 3D SSD is generated, is not created by combining transverse, sagittal, and coronal reconstructions. This statement is false because 3D SSD (Shaded Surface Display) is a technique used in medical imaging to create a 3D representation of the surface of an object or tissue. It does not involve combining different reconstructions. Instead, it uses the original image data to create a 3D surface representation.
19.
CT numbers _____ would appear black if a window width of 400 and a window level of -100 are used.
Correct Answer
B. Below -300
Explanation
If CT numbers are below -300 and a window width of 400 and a window level of -100 are used, they would appear black. This is because the window width determines the range of CT numbers that will be displayed, and the window level determines the midpoint of that range. In this case, the window width of 400 is wider than the range of CT numbers below -300, so all CT numbers below -300 would fall outside the range and appear black.
20.
Which of the following is the complete name of the laboratory test known as PTT?
Correct Answer
B. Partial thromboplastin time
Explanation
The correct answer is "partial thromboplastin time." Thromboplastin time is a laboratory test that measures the time it takes for blood to clot. However, the term "partial" is necessary to specify that only a partial version of thromboplastin is used in the test. Prothrombin time, on the other hand, measures the time it takes for blood to clot and is not the complete name for the PTT test. Partial prothrombin time is not a recognized laboratory test.
21.
Lower osmolar contrast media:
Correct Answer
C. Typically has a higher concentration of particles compared to blood
Explanation
Lower osmolar contrast media typically has a higher concentration of particles compared to blood. This means that it contains a higher number of solute particles per unit of volume compared to the blood. This higher concentration of particles can enhance the contrast in imaging studies, making it easier to visualize structures and abnormalities. However, the higher concentration of particles can also increase the risk of adverse reactions, although it is not mentioned in the question.
22.
What is the range of anatomy that should be covered for examination of one intervertebral disk space?
Correct Answer
A. From the pedicle of the vertebra above the disk to the pedicle of the vertebra below the disk
Explanation
The range of anatomy that should be covered for examination of one intervertebral disk space is from the pedicle of the vertebra above the disk to the pedicle of the vertebra below the disk. This means that the examination should include the structures surrounding and connecting the vertebrae, specifically the pedicles, which are bony projections that connect the vertebral body to the rest of the vertebra. By examining this range, a comprehensive evaluation of the intervertebral disk space can be achieved.
23.
For CT exams of the chest, the patient is usually positioned:
Correct Answer
D. Head first and supine
Explanation
For CT exams of the chest, the patient is usually positioned head first and supine. This means that the patient's head is placed first into the CT machine, followed by the rest of the body. The supine position refers to lying face up on the examination table. This positioning allows for a clear visualization of the chest area and ensures that the patient's head is properly aligned with the imaging equipment.
24.
Which of the following affects beam hardening?1. the energies of the photons in the beam2. the thickness of the tissues traversed by the beam3. the types of tissues the beam passes through
Correct Answer
D. 1,2 & 3
Explanation
Beam hardening is a phenomenon that occurs in computed tomography (CT) imaging, where the X-ray beam passing through the patient's body becomes harder (higher energy) as it passes through different tissues. This is caused by the preferential absorption of lower-energy photons by the tissues, resulting in an increase in the average energy of the beam. Therefore, all three factors mentioned in the question - the energies of the photons in the beam, the thickness of the tissues traversed by the beam, and the types of tissues the beam passes through - can affect beam hardening.
25.
A CT artifact is:
Correct Answer
C. An anomaly in the CT image
Explanation
An anomaly in the CT image refers to any abnormality or irregularity that is observed in the CT scan. This could include artifacts such as streaks, blurring, or distortions in the image that are not representative of the actual anatomy or pathology being imaged. These artifacts can be caused by a variety of factors including patient motion, equipment malfunctions, or technical errors during image acquisition or processing. Identifying and understanding these anomalies is important for accurate diagnosis and interpretation of CT scans.
26.
Which of the following would display the greatest amount of partial volume artifact?
Correct Answer
A. A 10 mm slice from a 20 slice study
Explanation
A 10 mm slice from a 20 slice study would display the greatest amount of partial volume artifact. This is because a thicker slice (10 mm) has a higher chance of including multiple tissues with different densities within it, leading to partial volume averaging. Additionally, a 20 slice study may not have enough slices to adequately capture the details of the anatomy, resulting in more pronounced partial volume artifacts.
27.
Which of the following is a result of reducing the slice thickness to reduce partial volume effects?1. decreased anatomical coverage with the same number of slices2. increased spatial resolution3. increased appearance of noise
Correct Answer
D. All the above
Explanation
Reducing the slice thickness can result in decreased anatomical coverage with the same number of slices because thinner slices cover a smaller area. It can also lead to increased spatial resolution because thinner slices provide more detailed images. Additionally, reducing slice thickness can increase the appearance of noise because thinner slices may have a lower signal-to-noise ratio. Therefore, all of the given options (1, 2, and 3) are correct.
28.
Typically, what mAs is used in routine CT exams of the abdomen?
Correct Answer
B. 200 to 300
Explanation
In routine CT exams of the abdomen, a range of 200 to 300 mAs is typically used. This refers to the amount of milliampere-seconds, which is a measure of the radiation dose delivered during the scan. This range is considered appropriate for obtaining clear and detailed images of the abdominal structures while minimizing the radiation exposure to the patient.
29.
Which of the following is the typical scan delay after the initiation of injection of contrast media for studies of the liver?
Correct Answer
B. 65 to 75 seconds
Explanation
The typical scan delay after the initiation of injection of contrast media for studies of the liver is 65 to 75 seconds. This delay allows the contrast media to circulate through the liver and enhance the visualization of the blood vessels and liver parenchyma. It gives enough time for the contrast to reach the desired concentration in the liver, ensuring optimal image quality for diagnostic purposes.
30.
Which of the following window settings provides the best tissue differentiation within the liver?
Correct Answer
C. Window width = 140, window level = 60
Explanation
A window width of 140 and a window level of 60 provide the best tissue differentiation within the liver. A narrower window width allows for better contrast between different densities of tissues, while a higher window level helps to highlight the specific range of densities within the liver. This combination allows for optimal visualization and differentiation of liver tissue.
31.
For a CT scan of the spleen, which of the following is typically used?
Correct Answer
D. Both oral and IV contrast media
Explanation
For a CT scan of the spleen, both oral and IV contrast media are typically used. This is because the spleen is a highly vascular organ, and the use of both types of contrast media helps to enhance the visibility of the spleen and surrounding structures. IV contrast media is administered intravenously, allowing it to circulate throughout the bloodstream and highlight the blood vessels within the spleen. Oral contrast media is ingested orally, and it helps to outline the gastrointestinal tract, making it easier to differentiate the spleen from other abdominal organs.
32.
Which of the following structures is NOT part of the GI tract?
Correct Answer
B. Spleen
Explanation
The spleen is not part of the GI tract. The GI tract consists of a series of organs that are involved in the digestion and absorption of food, including the stomach, esophagus, and duodenum. The spleen, on the other hand, is part of the lymphatic system and is involved in filtering and removing old or damaged red blood cells from the bloodstream.
33.
For a routine CT exam of the pelvis, what gantry tilt is used?
Correct Answer
D. No tilt is used
Explanation
In a routine CT exam of the pelvis, no tilt is used. This means that the gantry remains in a horizontal position, perpendicular to the patient's body. Tilting the gantry is not necessary for imaging the pelvis as it can be adequately visualized without any tilt.
34.
Which of the following would not enhance during the first several minutes of a post-contrast CT study of the neck?
Correct Answer
A. LympH nodes
Explanation
During a post-contrast CT study of the neck, the administration of contrast agent enhances the visibility of blood vessels and lesions due to increased blood flow and vascularity. However, lymph nodes do not enhance significantly during this study because they lack a high vascularity compared to blood vessels and lesions. Therefore, lymph nodes would not enhance during the first several minutes of a post-contrast CT study of the neck.
35.
When positioning for a CT exam of the wrist, the patient should be positioned:
Correct Answer
B. Prone with the arm raised above the head
Explanation
The correct answer is "prone with the arm raised above the head." This position allows for better visualization of the wrist joint and surrounding structures. By raising the arm above the head, the wrist is extended, which helps to separate the bones and reduce overlap. Additionally, being in the prone position allows the forearm to be parallel to the detector, minimizing distortion and improving image quality.
36.
Which of the following types of contrast media has NO application for a CT study of the thoracic spine?1. intrathecal2. intravenous3. oral
Correct Answer
C. 3 only
Explanation
Intrathecal contrast media is injected into the spinal canal to enhance visualization of the spinal cord and nerve roots. Intravenous contrast media is injected into a vein to enhance visualization of blood vessels and tissues. Oral contrast media is ingested to enhance visualization of the gastrointestinal tract. In a CT study of the thoracic spine, there is no need to visualize the gastrointestinal tract, so oral contrast media has no application. Therefore, the correct answer is 3 only.
37.
In which of the following studies might cranial nerve XI be visualized?
Correct Answer
C. Soft tissue neck
Explanation
Cranial nerve XI, also known as the accessory nerve, is responsible for controlling the muscles of the neck and shoulder. Therefore, it would be visualized in a study of the soft tissue neck. The other options, such as the internal auditory canal, lumbosacral spine, and supratentorium, do not involve the visualization of the cranial nerve XI.
38.
In order to generate a 3D shaded surface rendering of the hips, the _____ data is used directly by the 3D reconstruction software.
Correct Answer
A. Image
Explanation
The correct answer is "image". In order to generate a 3D shaded surface rendering of the hips, the image data is used directly by the 3D reconstruction software. This means that the software takes the information from the image and uses it to create a three-dimensional representation of the hips, with shading and depth. The image data contains the necessary information for the software to accurately reconstruct the 3D model.
39.
Which of the following is TRUE regarding barium sulfate solutions used in CT?
Correct Answer
B. They are less concentrated than those used in conventional radiograpHy
Explanation
Barium sulfate solutions used in CT are less concentrated than those used in conventional radiography. This is because in CT, the goal is to enhance the contrast between different tissues and structures in the body, while minimizing the radiation dose to the patient. Therefore, a lower concentration of barium sulfate is used in CT to achieve the desired contrast without overexposing the patient to radiation. In conventional radiography, higher concentrations of barium sulfate may be used to obtain clearer images.
40.
Barium sulfate oral contrast media would be selected instead of iodinated oral contrast media because:1. it passes through the GI tract quicker2. the contrast media stays more dense in the distal GI tract3. the trauma patient may have a perforated bowel
Correct Answer
B. 2 only
Explanation
Barium sulfate oral contrast media would be selected instead of iodinated oral contrast media because it stays more dense in the distal GI tract. This means that it provides better visualization of the lower gastrointestinal tract, allowing for more accurate diagnosis of any abnormalities or conditions in that area. Additionally, the use of barium sulfate may be preferred in trauma patients who may have a perforated bowel, as it is less likely to leak into the abdominal cavity compared to iodinated contrast media.
41.
Which of the following may help to reduce adverse reactions resulting from the administration of IV contrast media?1. administer an antihistamine prior to the IV contrast injection2. increase the rate of injection3. use high osmolar contrast media
Correct Answer
A. 1 only
Explanation
Administering an antihistamine prior to the IV contrast injection may help to reduce adverse reactions resulting from the administration of IV contrast media. Antihistamines can help to prevent or reduce allergic reactions by blocking the release of histamine, which is responsible for many allergic symptoms. By administering an antihistamine before the injection, it can help to prevent or minimize any adverse reactions that may occur. Increasing the rate of injection or using high osmolar contrast media are not effective methods for reducing adverse reactions.
42.
Which of the following oral contrast agents is better for opacifying the distal small intestine?1. a non-ionic iodinated contrast agent2. an ionic iodinated contrast agent3. barium sulfate
Correct Answer
C. 3 only
Explanation
Barium sulfate is the better oral contrast agent for opacifying the distal small intestine. This is because it is not absorbed by the body and provides excellent visualization of the gastrointestinal tract. Ionic and non-ionic iodinated contrast agents are typically used for opacifying other parts of the gastrointestinal tract, but they are not as effective in opacifying the distal small intestine.
43.
Iodinated IV contrast agents perfuse normal:
Correct Answer
B. Liver tissues
Explanation
Iodinated IV contrast agents perfuse liver tissues because these agents are commonly used in medical imaging to enhance the visibility of blood vessels and organs. The liver is a highly vascular organ, meaning it has a rich blood supply, so when the contrast agent is injected into the bloodstream, it quickly reaches and perfuses the liver tissues. This allows for better visualization and evaluation of the liver during imaging procedures such as CT scans or angiograms.
44.
Which of the following is NOT a typical adverse reaction to oral contrast media used in CT?
Correct Answer
D. Hives
Explanation
Hives are not a typical adverse reaction to oral contrast media used in CT. Oral contrast media can cause adverse reactions such as abdominal cramping, diarrhea, and flatulence. However, hives, which are itchy, raised welts on the skin, are not commonly associated with the use of oral contrast media.
45.
A delay of about _____ seconds after the start of the IV contrast injection should be used for a helical scan of the neck.
Correct Answer
B. 35
Explanation
For a helical scan of the neck, a delay of about 35 seconds after the start of the IV contrast injection should be used. This delay allows the contrast to circulate through the blood vessels and enhance the visibility of the neck structures during the scan. A shorter delay may result in insufficient contrast enhancement, while a longer delay may lead to excessive contrast dispersion and reduced image quality. Therefore, 35 seconds is the optimal delay for a helical scan of the neck.
46.
If there is doubt regarding the sterility of the contrast media, the contrast media must be:
Correct Answer
B. Discarded
Explanation
If there is doubt regarding the sterility of the contrast media, it must be discarded. This is because using a potentially contaminated contrast media can lead to infections or other complications in patients. It is important to prioritize patient safety and avoid any risks associated with using a contaminated substance. Therefore, the correct course of action is to discard the contrast media in order to prevent any potential harm to the patient.
47.
The most common catheter size used in CT _____ gauge.
Correct Answer
C. 18 to 22
Explanation
The most common catheter size used in CT is 18 to 22 gauge. This size range is commonly used because it allows for adequate flow rates while still being small enough to minimize patient discomfort. Catheters of this size are also compatible with most CT injection systems, making them a practical choice for CT procedures.
48.
Renal function refers to which of the following organs?
Correct Answer
B. Kidney
Explanation
Renal function refers to the functioning of the kidneys. The kidneys play a vital role in filtering waste products, excess water, and toxins from the blood to form urine. They also help regulate blood pressure, electrolyte balance, and acid-base balance in the body. Therefore, the correct answer is kidney.
49.
In all states, patients are required by law to sign consent forms for the following reason:
Correct Answer
D. Signed consent forms are not required by law in every state
Explanation
The correct answer is that signed consent forms are not required by law in every state. This means that there are some states where it is not legally mandatory for patients to sign consent forms. The other options listed (permission to administer contrast, permission to perform surgical procedure, permission to administer sedation) are not the correct answer because they do not address the requirement of signed consent forms in every state.
50.
Which of the following values for prothrombin time are considered outside the normal range?1. 12 seconds2. 20 seconds3. 30 seconds
Correct Answer
D. 2 & 3
Explanation
The normal range for prothrombin time (PT) is 10 to 14 seconds.