1.
The adjacent pixels are measured to have difference of 1 HU unit. This amount to a tissue density difference of approximately
Correct Answer
A. 0.1%
Explanation
The adjacent pixels having a difference of 1 HU unit indicates a very small difference in tissue density. This suggests that the tissue densities are almost identical, with a difference of only 0.1%.
2.
The intensity of the CT x ray beam can be increased by
Correct Answer
B. Decreasing collimation
Explanation
Decreasing collimation refers to narrowing the X-ray beam, which results in a higher intensity of the beam. This is because when the collimation is decreased, the X-ray beam is focused on a smaller area, concentrating the energy and increasing the intensity. Therefore, decreasing collimation is a way to increase the intensity of the CT X-ray beam.
3.
When choosing a window to display a CT image, the width defines the
Correct Answer
B. Range of CT numbers to be displayed
Explanation
The width of a window in displaying a CT image refers to the range of CT numbers that will be displayed. The CT numbers represent the density or attenuation of the tissues in the image. By adjusting the width, the user can control the range of CT numbers that are visible, allowing for better visualization of specific tissues or structures.
4.
Which of the following technologic advances has led to the development of spiral and helical CT scanning1 slip ring technology2 electron beam technology3 high efficiency x ray tubes
Correct Answer
C. 1 and 3
Explanation
Spiral and helical CT scanning require continuous rotation of the CT scanner and a constant power supply. Slip ring technology allows for the continuous rotation of the scanner without the need to stop and reverse direction. High efficiency x-ray tubes are necessary to produce the high-quality images required for spiral and helical CT scanning. Electron beam technology is not directly related to the development of spiral and helical CT scanning. Therefore, the correct answer is 1 and 3.
5.
Simple cysts of the kidney have average attenuation values in the range of
Correct Answer
B. 0 to 20 HU
Explanation
Simple cysts of the kidney typically have average attenuation values in the range of 0 to 20 HU. Attenuation values are measurements of how much the X-ray beam is weakened as it passes through different tissues. Simple cysts are fluid-filled sacs that are usually benign and do not cause any symptoms. They appear as low-density areas on CT scans, meaning they allow more X-ray beams to pass through them and have lower attenuation values. Therefore, the correct answer is 0 to 20 HU.
6.
After initiation of rapid bolus administration of an iodinated contrast agent, the arterial phase of hepatic contrast enhancement occurs at aproximately:
Correct Answer
B. 25-35 sec
Explanation
After the rapid bolus administration of an iodinated contrast agent, the arterial phase of hepatic contrast enhancement occurs at approximately 25-35 seconds. This is because the contrast agent quickly enters the bloodstream and is rapidly distributed to the liver via the hepatic artery. The arterial phase is characterized by intense enhancement of the hepatic vasculature, allowing for better visualization of the arterial supply to the liver.
7.
The accumulation of gas within a degenerating intervertebral dis is called
Correct Answer
B. Vacuum pHenomenon
Explanation
The correct answer is "vacuum phenomenon." The accumulation of gas within a degenerating intervertebral disc is known as the vacuum phenomenon. This occurs when the disc degenerates and gas, primarily nitrogen, enters the disc space. The gas accumulates and forms a vacuum, which can be seen on imaging studies such as X-rays or MRI scans. The vacuum phenomenon is often associated with disc degeneration and can be a sign of disc herniation or other spinal conditions.
8.
During a spiral or helical CT examination, the scanner acquires data:
Correct Answer
E. A & C
Explanation
During a spiral or helical CT examination, the scanner acquires data continuously as the patient travels through the gantry and in the form of a complete volumetric data set. This means that the scanner captures data in a continuous manner as the patient moves through the scanner, allowing for a more efficient and faster scanning process. Additionally, the scanner collects data in the form of a complete volumetric data set, which means that it captures images of the entire area being scanned, providing a comprehensive view of the anatomy.
9.
Which of the following CT studies of the head is typically performed without a contrast agent?
Correct Answer
C. CT of brain to r/o subdural hematoma
Explanation
A CT scan of the brain to rule out a subdural hematoma is typically performed without a contrast agent because the presence of blood in the subdural space can be easily detected without the need for contrast enhancement. Contrast agents are typically used in CT angiograms to visualize blood vessels, in coronal scans to evaluate pituitary tumors, and in CT scans to rule out metastatic disease. However, in the case of a subdural hematoma, the blood is already present and can be easily identified on a non-contrast CT scan.
10.
Which of the following phases of renal contrast enhancement best demonstrates transitional cell carcinoma (TCC) of the bladder?
Correct Answer
D. Excretory
Explanation
Excretory phase of renal contrast enhancement best demonstrates transitional cell carcinoma (TCC) of the bladder. During this phase, the contrast agent has been filtered by the kidneys and is excreted into the bladder. TCC is a type of bladder cancer that arises from the transitional epithelium lining the bladder. By the excretory phase, the contrast agent has reached the bladder, allowing for better visualization and detection of any abnormalities, such as TCC.
11.
Which of the follwoing sets of section width and spacing would be most suitable for a general survey CT oe neck?
Correct Answer
C. 3 mm thick every 3 mm
Explanation
A general survey CT of the neck requires high-resolution imaging to capture detailed structures. The set of section width and spacing that would be most suitable for this purpose is 3 mm thick every 3 mm. This means that each section will have a thickness of 3 mm and there will be no gaps larger than 3 mm between each section. This allows for a comprehensive and detailed examination of the neck area, ensuring that no important structures or abnormalities are missed.
12.
The still viable ischemic cerebral tissue that surrounds the infarct core in a patient with an acute stroke is termed the :
Correct Answer
C. Ischemic penumbra
Explanation
The term "ischemic penumbra" refers to the still viable ischemic cerebral tissue that surrounds the infarct core in a patient with an acute stroke. This area is at risk of becoming infarcted if blood flow is not restored promptly. It is important to identify and treat the ischemic penumbra in order to prevent further damage and improve patient outcomes.
13.
Diffuse fatty inflitration of the hepatic parenchyma may be referred to as:
Correct Answer
B. Steatosis
Explanation
Steatosis refers to the diffuse fatty infiltration of the liver parenchyma. It is a condition characterized by the accumulation of fat within the liver cells. This can occur due to various factors such as obesity, alcohol abuse, diabetes, and certain medications. Steatosis is considered an early stage of liver disease and if left untreated, it can progress to more severe conditions such as cirrhosis. Lipomatosis refers to the abnormal accumulation of fat in non-adipose tissues, while chromatosis and cirrhosis are not specifically related to fatty infiltration of the liver.
14.
Which of the following pathologic processes may be considered an interstitial disease of the lung?
Correct Answer
A. Bronchiectasis
Explanation
example interstitial diseases are bronchiectasis, emphysema, asbestosis, and sarcoidosis
15.
An enterovesical fistula is an abnormal communication btw the bowel and the
Correct Answer
B. Bladder
Explanation
An enterovesical fistula is an abnormal communication between the bowel and the bladder. This means that there is a passage or connection that has formed between these two organs, allowing the contents of the bowel to enter the bladder. This can lead to various symptoms such as urinary tract infections, urinary incontinence, and passage of gas or feces in the urine. Therefore, the correct answer is bladder.
16.
Prior to a CT colongraphy, the patient may undrgo a process of bowel cleansing termed:
Correct Answer
C. Catharsis
Explanation
Catharsis is the correct answer because prior to a CT colongraphy, the patient needs to undergo a process of bowel cleansing. Catharsis refers to the process of emptying the bowels through the use of laxatives or other methods to ensure that the colon is clean and free of any fecal matter or debris. This is necessary for accurate imaging and diagnosis during the CT colongraphy procedure.
17.
The imaging plane that is parallel to the foot's plantar surface is called
Correct Answer
C. Axial plane
Explanation
The axial plane is the correct answer because it refers to an imaging plane that is parallel to the foot's plantar surface. This plane divides the body into superior and inferior portions, making it ideal for visualizing structures in the foot from a side view. The coronal plane divides the body into anterior and posterior portions, the sagittal plane divides it into left and right portions, and the oblique axial plane is not a recognized term in anatomy.
18.
The condition of intermittent cramping pain in the legs due to poor circulation is called
Correct Answer
B. Claudication
Explanation
Claudication is the correct answer because it refers to the condition of intermittent cramping pain in the legs caused by poor circulation. This pain typically occurs during physical activity and is relieved with rest. Varices, stenosis, and thrombosis are not specifically related to poor circulation and do not describe the symptoms mentioned in the question.
19.
Which of the following terms is used to describe a fibroid tumor of the uterus?
Correct Answer
A. Leiomyoma
Explanation
identified on CT examination as a bulky
20.
The section thickness that would demonstrate the greatest detail of the paranasal sinuses is
Correct Answer
A. 3 mm
Explanation
A section thickness of 3 mm would demonstrate the greatest detail of the paranasal sinuses because it is a thinner section compared to 5 mm and 7 mm. Thinner sections provide higher resolution and allow for better visualization of small structures and details. Therefore, a 3 mm section thickness would provide the best opportunity to capture the intricate details of the paranasal sinuses.
21.
Which of the following anatomic organs is located within the peritoneal cavity?
Correct Answer
D. Liver
Explanation
contains stomach, liver, gallbladder, spleen, ovaries, transverse colon, and most of small bowel
22.
Which of the following may be included as part of a routin preparation for a general contrast-enhanced CT examination of the abdomen and pelvis?
Correct Answer
E. A and B
Explanation
The correct answer is A and B. Instructing the patient to take nothing by mouth for 4 hours prior to the exam helps ensure that the stomach and intestines are empty, allowing for better visualization of the abdominal and pelvic structures. Administering 1200 mL of oral contrast agent 90 minutes before the exam helps to enhance the visibility of the gastrointestinal tract and any abnormalities within it. Therefore, both of these measures are commonly included as part of the routine preparation for a general contrast-enhanced CT examination of the abdomen and pelvis.
23.
The recommended scan field of view (SFOV) for a CT examination of the cervical spine is:
Correct Answer
D. 50.0 cm
Explanation
DFOV between 10 and 15 cm
24.
Air trapping within the trachea and bronchial tree may be optimally demonstrated with multiplanar volume reconstruction (MPVRs) of the thorax known as:
Correct Answer
D. Minimum intensity projections (min-IPs)
25.
The Lisfranc joint is the articulation between the:
Correct Answer
A. Tarsals and metatarsals
Explanation
site complex fractures and dislocations of the foot
26.
The volume and density of calcium measured in the coronary arteries on MDCT examination are quantified with use of a value called the:
Correct Answer
C. Agatston score
Explanation
The Agatston score is used to quantify the volume and density of calcium measured in the coronary arteries on MDCT examination. It is a value that helps assess the amount of calcified plaque in the arteries, which is an indicator of coronary artery disease. The score is calculated by multiplying the area of calcified plaque by a density factor derived from the peak Hounsfield units. Higher Agatston scores indicate a higher risk of cardiovascular events.
27.
Which of the following contrast media may be utilized during the CT evaluation of the gastrointestinal tract?
Correct Answer
E. A,b,and c
Explanation
Diatrizoate meglumine (Gastrografin), effervescent agents, and iopamidol (Isovue) may all be utilized as contrast media during the CT evaluation of the gastrointestinal tract.
28.
Which of the pelvic bones cobine(s) to form the acetabulum?
Correct Answer
E. A, B, and C
Explanation
The acetabulum is formed by the combination of the ilium, ischium, and pubis bones. These three pelvic bones come together to create a socket-like structure that connects with the head of the femur, forming the hip joint.
29.
At what percentage of overlap should CT sections be reconstructed to improve the quality of multiplannar reformation (MPR) images?
Correct Answer
C. 50%
Explanation
CT sections should be reconstructed with a 50% overlap to improve the quality of multiplanar reformation (MPR) images. This percentage of overlap ensures that there is enough information from adjacent sections to accurately reconstruct the images in different planes. With a 50% overlap, the MPR images will have better resolution, reduced artifacts, and improved visualization of anatomical structures compared to lower percentages of overlap.
30.
The degenerative pathologic process involving the forward slipping of an upper vertebral body over a lower vertebral body is called:
Correct Answer
A. Spondylolisthesis
Explanation
a result of degenerative changes of the facet joints.
31.
Accurate demonstration of --------------------would most likely required the intravenous injection of an iodinated contrast agent during a CT study of the chest
Correct Answer
C. Mediastinal lympHadenopathy
Explanation
In order to accurately demonstrate mediastinal lymphadenopathy during a CT study of the chest, it is most likely necessary to administer an intravenous injection of an iodinated contrast agent. This contrast agent helps to enhance the visibility of the lymph nodes and surrounding structures, allowing for a clearer and more detailed image. This is particularly important in the case of mediastinal lymphadenopathy, as it involves the enlargement of lymph nodes in the mediastinum, which is the central area of the chest. By using the contrast agent, it becomes easier for radiologists to identify and evaluate any abnormalities or changes in the lymph nodes.
32.
A focused, thin section axial CT acquisition through just the regionof the vocal cords should extend:
Correct Answer
B. From above the hyoid bone inferiorly through the cricoid cartilage
Explanation
The correct answer is from above the hyoid bone inferiorly through the cricoid cartilage. This is because the vocal cords are located in the larynx, which is situated between the hyoid bone and the cricoid cartilage. Therefore, a focused, thin section axial CT acquisition through just the region of the vocal cords should capture this specific area.
33.
During CT perfusion studies, the quantity of blood (in mL) that moves through 100 g of tissue each minute is termed the:
Correct Answer
B. Cerebral blood flow (CBF)
Explanation
During CT perfusion studies, the quantity of blood that moves through 100 g of tissue each minute is termed cerebral blood flow (CBF). This measurement is important in assessing the perfusion of blood to the brain and can provide valuable information about the health and function of brain tissue. By measuring the CBF, doctors can identify areas of reduced blood flow, which may indicate ischemia or other vascular abnormalities. This information can help guide treatment decisions and monitor the effectiveness of interventions aimed at improving blood flow to the brain.
34.
The enhancement washout technique for CT characterization of adrenal masses includes:
Correct Answer
D. A and C
Explanation
The enhancement washout technique for CT characterization of adrenal masses includes thin section pre-contrast acquisition through the adrenals and 10 to 15 minute delayed post-contrast acquisition through the adrenals. This technique allows for the evaluation of the washout characteristics of the adrenal mass, which can help differentiate between benign and malignant lesions. The pre-contrast acquisition provides baseline information about the mass, while the delayed post-contrast acquisition allows for assessment of the washout of contrast material from the mass. By combining these two acquisitions, radiologists can make a more accurate characterization of the adrenal mass.
35.
Bowel obstruction due to loss of normal contractile motion in an area of intestine is termed:
Correct Answer
C. Ileus
Explanation
Ileus refers to a condition where there is a loss of normal contractile motion in a section of the intestine, leading to a bowel obstruction. This can occur due to various reasons such as inflammation, surgery, or medication side effects. Dyspepsia refers to indigestion or discomfort in the upper abdomen. Intussusception is a condition where one part of the intestine slides into another part, causing a blockage. Adhesion refers to the formation of scar tissue that can cause organs or tissues to stick together. Therefore, the correct answer is ileus.
36.
The tird ventricle of the brain communicates with the fourth ventricle through the:
Correct Answer
C. Cerebral aqueduct
Explanation
The cerebral aqueduct is a narrow canal that connects the third ventricle of the brain to the fourth ventricle. It is located within the midbrain, specifically in the region called the mesencephalon. This canal allows for the passage of cerebrospinal fluid (CSF) between the two ventricles. CSF is a clear fluid that surrounds and protects the brain and spinal cord, and it plays a crucial role in maintaining the brain's homeostasis. Therefore, the cerebral aqueduct serves as a vital pathway for the circulation of CSF within the brain.
37.
Complete CT examinations of the chest for investigation of bronchogenic carcinoma should include sections from the:
Correct Answer
C. Top of the apices through the liver
Explanation
A complete CT examination of the chest for investigation of bronchogenic carcinoma should include sections from the top of the apices through the liver. This is because bronchogenic carcinoma primarily affects the lungs, and therefore it is important to include the entire lung field in the imaging. The apices are the uppermost part of the lungs, and including them in the scan ensures that any abnormalities in that area can be detected. The liver is included in the scan because it is a common site for metastasis of bronchogenic carcinoma.
38.
The prone position may be used for a postmyelogram CT examination of the lumbar spine in an effort to :
Correct Answer
C. Reduce metrizamide pooling
Explanation
The prone position is used for a postmyelogram CT examination of the lumbar spine to reduce metrizamide pooling. Metrizamide is a contrast agent that is injected into the spinal canal during a myelogram to help visualize the spinal cord and nerves. When the patient is in the prone position, gravity helps to distribute the metrizamide more evenly throughout the spinal canal, reducing the pooling of the contrast agent in certain areas. This allows for better visualization of the entire lumbar spine during the CT examination.
39.
After initiation of rapid bolus administration of iodinated contrast material, the pancreatic phase of contrast enhancement occurs at approximatly
Correct Answer
B. 35-45 sec
Explanation
The pancreatic phase of contrast enhancement occurs approximately 35-45 seconds after the initiation of rapid bolus administration of iodinated contrast material. This means that during this time frame, the contrast material reaches and enhances the pancreatic tissue, allowing for better visualization and assessment of the pancreas during imaging studies such as computed tomography (CT) scans.
40.
The average density of a mass within the kidney measure -75 Hounsfield units (HU). the mass is most likely a:
Correct Answer
B. Lipoma
Explanation
fat is -50 to -100
41.
An enema is indicated prior to a CT examination of the pelvis to administer postitive contrast material into the large bowel. Which of the following dosages would be sufficient to opacify the rectosigmoid region?
Correct Answer
A. 150-250 ml
Explanation
An enema is a procedure used to introduce contrast material into the large bowel for imaging purposes. In this case, the enema is being done prior to a CT examination of the pelvis to opacify the rectosigmoid region. The correct dosage range for opacifying the rectosigmoid region is 150-250 ml. This amount of contrast material is sufficient to provide clear imaging of the area without causing excessive distention or discomfort to the patient.
42.
The stanford type A desecting aneurysm affects which portion of the aorta?
Correct Answer
A. Ascending thoracic(arota)
Explanation
Stanford type B dissecting aneurysms affect the descending aorta
43.
During HRCT of the lungs, edematous changes in the posterior lungs may be differentiated by positioning of the patient in th e---------postion
Correct Answer
D. Prone
Explanation
edematous changes often seen in the lung bases
44.
The firm, outer portion of each intervertebral disc is called the:
Correct Answer
C. Anulus fibrosus
Explanation
The correct answer is anulus fibrosus. The anulus fibrosus refers to the firm, outer portion of each intervertebral disc. It is made up of tough, fibrous cartilage that surrounds the nucleus pulposus, the inner gel-like substance of the disc. The anulus fibrosus provides support and stability to the disc, preventing the nucleus pulposus from bulging out or herniating.
45.
Surgical resection of the pancreas and duodenum for treatment of pancreatic carcinoma
Correct Answer
D. Whipple procedure
Explanation
The Whipple procedure is a surgical resection of the pancreas and duodenum commonly used to treat pancreatic carcinoma. It involves removing the head of the pancreas, the duodenum, a portion of the bile duct, and sometimes a portion of the stomach. The remaining organs are then reconnected to allow for normal digestion and bile flow. This procedure is considered the standard treatment for pancreatic carcinoma that is confined to the head of the pancreas and is performed to remove the tumor and prevent its spread.
46.
Which of the following IV contrast phases does the bladder wall enhance
Correct Answer
C. NepHrograpHic
Explanation
Nephrographic (70-90 sec)
47.
Coronary artery calcium (CAC) quantitation by MDCT exam is used primarily to assess:
Correct Answer
B. Atherosclerotic disease
Explanation
MDCT exam is a diagnostic tool used to measure the amount of calcium in the coronary arteries. The presence of calcium in the coronary arteries indicates the presence of atherosclerosis, which is the buildup of plaque in the arteries. Therefore, the primary purpose of CAC quantitation by MDCT exam is to assess atherosclerotic disease. This test helps in identifying individuals at risk for coronary artery disease and allows for early intervention and treatment.
48.
A specialized CT examination involving the administration of an enteral contrast agent directly into the small bowel via nasogastric tube is called
Correct Answer
A. CT enteroclysis
Explanation
CT enteroclysis is a specialized CT examination that involves the administration of an enteral contrast agent directly into the small bowel via a nasogastric tube. This procedure allows for detailed imaging of the small intestine and helps to diagnose conditions such as Crohn's disease, tumors, and obstructions. CT colonography, on the other hand, is a technique used to visualize the colon and rectum, while CT enterography is a similar procedure that focuses on imaging the small intestine. CT colonoscopy involves the use of a flexible tube to examine the colon.
49.
The epithelial lining of the urinary tract called the:
Correct Answer
C. Urothelium
Explanation
site of transitional cell carcinoma (TCC), common malignacy of the bladder, ureters, and kidneys
50.
Delayed post-contrast acquistion of the lower extremities following a CTA of the pulmonary arteries is termed:
Correct Answer
A. CT venograpHy
Explanation
After the CTPA acquisition, a delay of 2 to 3 minutes is employed, and an acquisition is made from iliac crest to ankles CT venography (CTV)