CT Registry Preparation Quiz

The talus is not a bony structure of the pelvis. The pelvis consists of the ilium, ischium, and pubic ramis, which are all part of the pelvic bones. The talus, on the other hand, is a bone located in the foot, specifically in the ankle joint. It articulates with the tibia and fibula to form the ankle joint, but it is not part of the pelvis.

The thoracic region of the spinal column contains 12 vertebrae. This is because the thoracic region is located in the middle of the spine and is responsible for supporting the rib cage. There are 12 pairs of ribs, and each rib is attached to a vertebra in the thoracic region. Therefore, there must be 12 vertebrae in this region to accommodate the ribs and provide stability and protection to the chest area.

The most common patient position for an abdominal CT scan is feet first, supine. This means that the patient's feet are positioned first into the CT scanner, and they are lying on their back. This position allows for a clear view of the abdominal area and is commonly used for abdominal imaging. The other options, such as head first or decubitis, are not typically used for abdominal CT scans.

The correct answer is axial. Axial plane refers to a horizontal plane that divides the body into upper and lower parts. In CT imaging, most images are displayed in the axial plane as it provides a clear view of the internal structures and allows for accurate diagnosis and evaluation of various conditions. Sagittal, coronal, and oblique planes are also used in CT imaging, but they are less commonly utilized compared to the axial plane.

CT scans can be performed even if the patient is wearing a plaster cast. CT scans use X-ray technology to create detailed images of the inside of the body, and the plaster cast does not interfere with this process. However, it is important to ensure that the cast does not contain any metal components, as these can cause artifacts in the CT images. Additionally, the cast may need to be cut or removed if the area being scanned is directly underneath it. Therefore, the statement that CT should not be used if the patient is wearing a plaster cast is false.

The fallopian tubes are NOT normally visible on CT scanning. CT scanning is a diagnostic imaging technique that uses X-rays to create detailed cross-sectional images of the body. While the uterus, ovaries, and symphysis pubis can be visualized on CT scans, the fallopian tubes are typically not visible due to their small size and location deep within the pelvis. Therefore, the correct answer is fallopian tubes.

All chest CT scans must display the lung apices on the initial image because the lung apices are the highest points of the lungs and can provide important information about lung pathology, such as the presence of lung nodules or tumors. Additionally, the lung apices are also important in assessing conditions like pneumothorax (collapsed lung) or pleural effusion (fluid accumulation in the lungs). Therefore, including the lung apices in the initial image is crucial for a comprehensive evaluation of the chest.

CT of the scapula is not used as a replacement for arthrography to assess the integrity of the rotator cuff. Arthrography is a specific imaging technique that involves injecting a contrast agent into the joint to evaluate the structures within it, such as the rotator cuff. CT scans of the scapula are typically used for detecting fractures that cannot be seen on plain film x-ray, mapping out the relationship among bone fragments in cases of complex fracture, and determining the degree of fracture displacement from trauma.

The acetabulum is the socket of the hip joint, formed by the fusion of three bones: the ilium, ischium, and pubis. The sacrum is not part of the acetabulum. It is a triangular bone located at the base of the spine, formed by the fusion of five vertebrae.

Mesothelioma is the correct answer because it is a form of lung cancer that is specifically linked to asbestos exposure. Asbestos is a known carcinogen and individuals who have been exposed to it, typically in occupational settings such as construction or mining, are at an increased risk of developing mesothelioma. This cancer affects the lining of the lungs and other organs, and its association with asbestos exposure is well-established. Adenocarcinoma, bronchoalveolar cell carcinoma, and squamous cell carcinoma are other forms of lung cancer that may have different causes and risk factors.

Slip ring technology allows for continuous rotation of the tube and detectors in a spiral CT scanner. This continuous rotation enables the scanner to capture images of the body in a helical or spiral pattern, resulting in faster scan times and improved image quality. Without slip ring technology, the tube and detectors would have to stop and reverse direction, which would disrupt the scanning process and potentially lead to inaccurate beam direction. Therefore, slip ring technology is essential for the continuous rotation of the tube and detectors in a spiral CT scanner.

Contrast media is not used in CT scans of the ankle to detect small fractures. Contrast media is typically used to enhance the visibility of blood vessels and soft tissues, allowing for a more accurate diagnosis of lesions and mapping of the vascular anatomy. However, small fractures can usually be detected without the use of contrast media, as they are visible on the CT scan images.

CT may be preferable to MRI in the knee for all of the given indications except for the evaluation of anterior cruciate ligament tears. CT scans are useful for presurgical mapping of the area, detection of patellofemoral disorders, and detection of bony lesions. However, MRI is generally the preferred imaging modality for the evaluation of anterior cruciate ligament tears due to its ability to provide detailed images of soft tissues, such as ligaments.

The question is asking about the information that should not be asked to patients who have had a prior allergic reaction to a contrast agent. The correct answer is "are you allergic to shellfish?" This is because the question is specifically about allergic reactions to contrast agents, not shellfish allergies. The other options are relevant as they inquire about the symptoms, hospitalization, and treatment related to the prior allergic reaction.

The structures of the colon that give it a "pillow-like" appearance are called haustra. These are small pouches or sacs that form along the length of the colon. They are formed by the contraction of the circular muscles in the colon, which create a series of bulges or indentations. The haustra allow for the expansion and contraction of the colon as it moves waste material through the digestive system.

A history of severe hypersensitivity to insect stings is not a potential risk factor for an adverse reaction to iodinated contrast. Adverse reactions to iodinated contrast are typically related to renal function, so renal disease is a potential risk factor. Diabetes and congestive heart failure can also increase the risk of adverse reactions. However, a history of severe hypersensitivity to insect stings is unrelated to the administration of iodinated contrast and would not contribute to an adverse reaction.

The xiphoid process of the sternum is used as a landmark in localizer scans. The xiphoid process is a small, cartilaginous extension at the lower end of the sternum. It can be easily palpated and serves as a reference point for locating other structures in the body. In localizer scans, which are used to determine the position and orientation of the body for imaging purposes, the xiphoid process helps ensure accurate and consistent positioning of the patient.

It appears as TWO distinct columns

High resolution chest CT is commonly used for evaluating various lung conditions. It is particularly useful for assessing the extent of emphysema, evaluating suspected bronchiectasis, and assessing asbestosis. However, pulmonary embolism is typically diagnosed using other imaging modalities such as CT angiography or ventilation-perfusion scans. Therefore, evaluation of pulmonary embolism is not an indication for high resolution chest CT.

The ulnar collateral ligament is the correct answer because it is responsible for reinforcing the medial side of the elbow joint. This ligament connects the ulna bone to the humerus bone and provides stability to the inner side of the elbow, preventing excessive side-to-side movement.

In an upper abdominal localizer scan, the scanning range should extend from two inches above the xiphoid notch to the superior margin of the sacroiliac joint. This is because the upper abdominal region includes the liver, gallbladder, stomach, and other organs that are located above the xiphoid notch. The sacroiliac joint is the joint between the sacrum and the ilium bones in the pelvis, and it marks the lower boundary of the upper abdominal region. Therefore, the scanning range should extend up to the superior margin of the sacroiliac joint to ensure that all relevant structures within the upper abdomen are captured in the scan.

Contrast-enhanced CT is a diagnostic imaging technique that uses a contrast agent to help visualize and highlight certain structures or abnormalities in the body. It is commonly used to diagnose primary tumors, metastases, and infections by enhancing the visibility of these conditions. However, it is not typically used to assess spinal cord integrity as it primarily focuses on identifying and evaluating abnormalities within the body. Therefore, the correct answer is spinal cord integrity.

The most common patient position for spine and musculoskeletal scanning is feet first, supine. This position allows for optimal visualization of the spine and musculoskeletal structures. Placing the feet first helps to minimize motion artifacts and allows for better alignment of the body during the scan. The supine position, with the patient lying flat on their back, is preferred as it provides a stable and comfortable position for the patient.

Multidetector-row CT scanning offers several benefits, such as allowing evaluation of small bowel disease using routine protocols, enabling identification of bowel obstruction with or without ischemia, and allowing the acquisition of images of the mesenteric circulation during the same scan. However, the large number of images to manage is not a benefit of this type of scanning. This implies that managing a large number of images may be challenging or time-consuming, which is not advantageous.

A typical contrast dose is not 350 mL of a nonionic iodinated contrast.

A Hounsfield value of +10 likely represents an ovarian cyst. The Hounsfield value is a measure of the density of a structure in a CT scan. A value of +10 suggests that the structure has a density similar to water. Ovarian cysts are fluid-filled sacs that can be seen on CT scans and often have a density similar to water. Fibroid uterus, diverticular abscess, and endometrial tumor would typically have different Hounsfield values.

The correct answer is splenic. Large vessels of the mediastinum that can be visualized on CT scans include the common carotid artery, subclavian artery, and brachiocephalic artery. However, the splenic artery is not located in the mediastinum, but rather in the abdomen. Therefore, it cannot be visualized on CT scans of the mediastinum.

A typical concentration of iodinated contrast used in musculoskeletal CT studies is 150 mgI/mL. This concentration is commonly used as it provides sufficient contrast enhancement for imaging the musculoskeletal system. Higher concentrations may not be necessary and could increase the risk of adverse reactions, while lower concentrations may not provide adequate visualization of the structures of interest. Therefore, 150 mgI/mL is the preferred concentration for musculoskeletal CT studies.

The preferred rate of delivery of intravenous contrast for routine abdominal and pelvic scans is 2-3 cc/sec. This rate ensures that the contrast is delivered at a steady pace, allowing for better visualization of the organs and structures in the abdomen and pelvis. A rate that is too slow may result in inadequate contrast enhancement, while a rate that is too fast may lead to excessive contrast pooling or washout, compromising the quality of the scan. Therefore, a rate of 2-3 cc/sec is considered optimal for these types of scans.

The peritoneum is a thin membrane that lines the abdominal cavity from the diaphragm to the pelvis. It is responsible for providing support and protection to the abdominal organs, as well as allowing for movement and flexibility within the abdominal cavity. The peritoneum also plays a role in the absorption and transport of nutrients and waste products.

The correct answer states that although scan times are shorter, a breath hold of up to 30 seconds may be needed, as scans are now covering wider body areas. This is because wider body areas require more time to capture all the necessary images, even with shorter scan times. Therefore, the patient may still need to hold their breath for a period of time to ensure clear and accurate images are obtained.

The tibia articulates with the femur at the medial and lateral condyles. This means that the tibia forms joints with both the inner (medial) and outer (lateral) parts of the femur. These articulations allow for movement and stability between the two bones, contributing to the overall function of the knee joint.

The rich arterial network of the pancreas is responsible for supplying oxygen and nutrients to the pancreatic tissue. During the arterial phase, the blood flow to the pancreas is at its peak, resulting in a marked enhancement of the pancreatic parenchyma. This enhancement is seen on imaging studies such as CT scans or MRIs, where the pancreas appears brighter and more distinct due to the increased blood flow.

The popliteal vein is the correct answer because it is a major blood vessel in the lower extremity that is prone to forming blood clots (thrombi). These blood clots can break off and travel to the lungs, causing a pulmonary embolism. The popliteal vein is located behind the knee in the popliteal fossa, making it more susceptible to blood clot formation. The other options, such as the popliteal fossa, posterior tibial artery, and femoral artery, are not major sources of thrombi leading to pulmonary embolism.

The given answer, 0.375, suggests that the minimum CT scan times per slice in 2004 were 0.375 seconds. This means that there has been a significant reduction in the time required for CT scans over the years, from 5 minutes per slice in 1976 to 0.375 seconds per slice in 2004. This advancement in technology has allowed for faster and more efficient CT scans, improving patient experience and reducing waiting times.

Routine CT of the cervical spine is typically performed to evaluate for fractures, radiculopathy, and stenosis. Osteogenesis imperfecta is a genetic disorder characterized by brittle bones and would not be an indication for routine CT of the cervical spine. Therefore, osteogenesis imperfecta is the correct answer for this question.

Studies of CT colonoscopy results have shown a high sensitivity of approximately 90% for detecting colon polyps >10 mm. This means that out of all the colon polyps that are larger than 10 mm, the CT colonoscopy is able to correctly identify 90% of them. This high sensitivity indicates that CT colonoscopy is a reliable method for detecting larger colon polyps, which is important for early detection and prevention of colorectal cancer.

The intervertebral foramina are small openings between adjacent vertebrae. These foramina allow for the ingress (entry) and egress (exit) of nerve roots from the spinal cord. This means that the nerves can pass through these openings to connect with other parts of the body. The other options provided in the question, such as attachment sites for muscles or being present only in the lumbar vertebrae, are incorrect and do not accurately describe the function or location of the intervertebral foramina.

The supraspinatus tendon is the most frequently injured tendon of the rotator cuff. This is because it is located in a vulnerable position within the shoulder joint and is responsible for initiating the abduction of the arm. The supraspinatus tendon can become damaged or torn due to repetitive overhead movements, trauma, or degeneration over time. Its frequent involvement in rotator cuff injuries makes it a common source of shoulder pain and dysfunction.

The iliofemoral ligament is primarily responsible for stabilizing the anterior portion of the hip joint. It is the strongest ligament in the body and helps to prevent excessive extension of the hip joint. This ligament attaches from the ilium (part of the pelvis) to the femur (thigh bone), and its main function is to limit hyperextension and maintain stability during weight-bearing activities.

CT colonography is especially valuable in cases where obstructing lesions prevent complete evaluation with conventional colonoscopy. This means that when there are obstructions in the colon that hinder a thorough examination with traditional colonoscopy, CT colonography can be used as an alternative. It allows for evaluation of the colon even in the presence of obstructing lesions, providing valuable information that may not be possible with conventional colonoscopy.

The correct answer is 1-2. When performing a CT scan of the lumbar spine requiring contrast, the contrast should be injected at a rate of 1-2 cc/sec. This rate allows for a sufficient amount of contrast to be delivered to the area of interest while minimizing the risk of adverse reactions or complications. Injecting the contrast too quickly or too slowly may result in suboptimal imaging or potential harm to the patient.

The glenoid fossa is not a section of the scapula that serves as an attachment site for muscles. The glenoid fossa is actually a shallow depression on the scapula that forms the socket for the shoulder joint. It is where the head of the humerus (upper arm bone) articulates with the scapula to allow for shoulder movement. While the other options mentioned (scapular spine, acromion, and glenoid process) all serve as attachment sites for various muscles, the glenoid fossa does not have any muscle attachments.

The correct answer is teres lateralus. The teres lateralus is not one of the four muscles that form the rotator cuff in the shoulder. The four muscles that make up the rotator cuff are the supraspinatus, infraspinatus, teres minor, and subscapularis. The teres lateralus is not part of this group.

The proper scan delay time following the beginning of contrast delivery for a routine lumbar spine scan is to begin the scan following administration of the total contrast dose. This means that the scan should start after the entire amount of contrast has been injected into the patient. This allows sufficient time for the contrast to circulate throughout the body and reach the area of interest in the lumbar spine, ensuring optimal visualization of the structures during the scan. Delaying the scan for a specific amount of time (15 sec, 20 sec, or 30 sec) may not be necessary or appropriate in this case.

A CT colonoscopy bowel preparation consisting of oral hydration with a cathartic for colon contraction produces a drier colon. This means that the colon will have less fluid content compared to a polythlene glycol regimen.

The superior mesenteric artery is responsible for supplying blood to various organs in the abdominal region. It provides blood to the pancreatic head, jejunum, and ileum. However, it does not supply blood to the sigmoid colon. The sigmoid colon receives its blood supply from the inferior mesenteric artery.

The iliopsoas muscle provides the strongest flexing action for the hip. This muscle is a combination of the iliacus and the psoas major muscles, which originate from the lower spine and pelvis and insert onto the femur. When contracted, the iliopsoas muscle flexes the hip joint, bringing the thigh towards the abdomen. It is one of the primary muscles responsible for lifting the leg during activities such as walking, running, and climbing stairs.

IV contrast is effective for delineating mediastinal masses from surrounding mediastinal vessels. This means that when IV contrast is used, it helps to clearly distinguish mediastinal masses from the blood vessels in the mediastinum. This can be useful in the assessment of lung and mediastinal masses, as it allows for better visualization and characterization of these masses. The other statements are not true, as IV contrast is generally ineffective for identifying hilar masses, pneumonia enhances brightly on scanning without the need for contrast, and lung infiltrates and intraparenchymal lung cancers do not enhance with the use of iodinated contrast.

The pleurae are not an anatomic structure contained in the mediastinum. The mediastinum is the central compartment of the thoracic cavity, located between the lungs. It contains various structures such as the heart, aorta, trachea, thymus, esophagus, and lymph nodes. The pleurae, on the other hand, are the membranes that line the lungs and the inner surface of the chest wall. They are not located within the mediastinum itself.