CT Registry Review Test: Hardest Trivia Quiz!

The Dose Length Product (DLP) is expressed in units of milligrays per centimeter (mGy-cm).

The high-frequency generator in a modern CT scanner is often located inside the gantry. The gantry is the large ring-shaped structure that houses the X-ray tube and detector array. Placing the generator inside the gantry allows for a more compact design and reduces the length of the high-voltage cables that connect the generator to the X-ray tube. This helps to minimize electrical interference and improve the overall performance of the CT scanner. Additionally, having the generator inside the gantry allows for faster and more precise control of the X-ray output during the scanning process.

The angiocatheter would be best suited for intravenous injection of contrast material with a power injector because it is specifically designed for this purpose. It is a catheter that can be easily inserted into a vein and has a larger gauge size, allowing for the rapid injection of contrast material. The other options, such as the butterfly needle, central venous line, and 23-gauge spinal needle, are not designed for this specific purpose and may not be suitable for the high-pressure injection required for contrast material administration.

Voxels with equal dimensions along the x, y, and z axes are referred to as isotropic. Isotropic means that the voxel has uniform dimensions in all directions, resulting in equal resolution along each axis. This is important in medical imaging, as it allows for accurate and consistent measurements and comparisons of structures in three-dimensional space. Anisotropic voxels, on the other hand, have unequal dimensions along the axes, which can lead to variations in resolution and distortions in the image.

To reduce the radiation dose to a pediatric patient undergoing CT, three methods can be employed. First, reducing mA (milliamperage) helps to lower the radiation dose. Second, limiting phases of acquisition means reducing the number of scans or images taken, which also decreases the overall radiation exposure. Third, increasing pitch refers to the speed at which the patient table moves through the CT scanner. A higher pitch means the patient spends less time in the scanner, resulting in a lower radiation dose. Therefore, options 1, 2, and 3 are all valid methods to reduce the radiation dose in pediatric CT scans.

A comprehensive CT stroke management protocol typically includes a pre-contrast sequence of the brain, CTA of the brain and carotids, and CT perfusion (CTP) of the brain. These components are important for a thorough evaluation of the stroke, as they provide information about the location and extent of the stroke, as well as the blood flow in the brain. By combining these different imaging techniques, healthcare professionals can make more accurate diagnoses and determine the most appropriate treatment options for the patient.

The still viable ischemic cerebral tissue that surrounds the infarct core in a patient with an acute stroke is termed the ischemic penumbra. This refers to the area of the brain that is at risk of further damage due to inadequate blood supply but is still potentially salvageable if blood flow is restored in a timely manner. The term "ischemic penumbra" is used to describe this region of reversible ischemic injury in stroke patients.

Parenteral administration involves the injection of medication into the body. Common routes of parental medication administration include intramuscular, intravenous, intradermal, and subcutaneous.

The pituitary gland is best demonstrated during CT in the coronal imaging plane. This is because the coronal plane allows for a clear visualization of the pituitary gland, which is located at the base of the brain. The coronal plane provides a view from the front to the back of the body, making it ideal for assessing the pituitary gland's position and any abnormalities. The axial plane would provide a view from top to bottom, the sagittal plane would provide a view from side to side, and transaxial is not a recognized imaging plane.

The "triple rule-out" MDCT protocol is used to evaluate patients complaining of chest pain for three potential conditions: pulmonary embolism, aortic dissection, and coronary artery disease. This protocol involves performing a CTA of the pulmonary arteries to assess for pulmonary embolism, a CTA of the aorta to evaluate for aortic dissection, and a coronary CTA to assess for coronary artery disease. The only component that is NOT a part of this protocol is prone HRCT of the lungs, which is not typically included in the evaluation for these specific conditions.

Cine CT refers to the acquisition of a series of CT images at a single anatomic location over a set period. This technique allows for the visualization of dynamic processes, such as the movement of organs or blood flow, by capturing multiple images in rapid succession. Unlike conventional CT, which captures a single image at a specific moment, cine CT provides a temporal sequence of images, similar to a movie or "cine" loop. Ultrafast CT, on the other hand, refers to a specific type of CT scanner that can capture images very quickly, but it does not necessarily involve the acquisition of a series of images over time. Temporal CT is not a recognized term in the context of CT imaging.

During a complete CT scan of the pelvis, sections should be obtained from the iliac crests to the pubic symphysis. This is because the iliac crests are the highest point of the hip bones and the pubic symphysis is the joint between the two pubic bones. By including these landmarks in the scan, it ensures that the entire pelvis is captured in the imaging, providing a comprehensive view of the pelvic region.

CT cystography is the correct answer because it involves the administration of an iodinated contrast agent directly into the bladder via a Foley catheter. This procedure is used to visualize the bladder and detect any abnormalities or injuries. CT IVP (Intravenous Pyelogram) involves the injection of contrast dye into a vein to visualize the urinary system, CT urogram is a CT scan of the urinary tract, and CT enteroclysis is a CT scan of the small intestine.

SOLU-CORTEF is classified as a corticosteroid. Corticosteroids are a class of drugs that mimic the effects of hormones produced by the adrenal glands. They have anti-inflammatory and immunosuppressive properties, making them useful in treating a variety of conditions such as allergies, asthma, and autoimmune disorders. SOLU-CORTEF, specifically, is a brand name for hydrocortisone sodium succinate, which is commonly used as an injectable corticosteroid for emergency situations such as anaphylaxis or adrenal crisis.

usually gown and gloves which is enteric precautions.

Retrospective ECG gating is a technical maneuver that can be used to remove unwanted pulsation artifacts from cardiac motion during a CTA of the chest for pulmonary embolism. This technique involves acquiring images of the heart at different phases of the cardiac cycle and then reconstructing a motion-free image by selecting the best data from each phase. By synchronizing the image acquisition with the ECG signal, retrospective ECG gating ensures that the images are acquired at the same point in the cardiac cycle, minimizing motion artifacts caused by pulsation. This technique improves the diagnostic accuracy of the CTA by providing clearer images of the pulmonary arteries.

Sublingual nitroglycerine may be administered to dilate the coronary vasculature prior to a cardiac CT examination. Nitroglycerine is a vasodilator that works by relaxing and widening the blood vessels, including the coronary arteries. This helps to improve blood flow to the heart and can be beneficial before a cardiac CT examination to enhance the visualization of the coronary arteries.

A uniform matrix array is a type of MSCT detector array that consists of multiple rows of detector elements, all of which have the same length. This means that each row of detectors is identical in size and shape. This uniformity allows for consistent and accurate detection of X-ray signals across the entire array. It also enables the array to capture a larger volume of data in a single scan, improving the efficiency and speed of the imaging process.

The acetabulum is a cup-shaped socket in the hip bone where the head of the femur (thigh bone) articulates. It is formed by the fusion of three pelvic bones: the ilium, ischium, and pubis. Therefore, the correct answer is 1, 2, and 3, as all three bones combine to form the acetabulum.

The correct answer is hyperdense. The thyroid gland appears hyperdense on CT images due to its inherent iodine concentration. This means that it appears brighter or denser compared to the surrounding tissues.

The correct answer is L4. The abdominal aorta is the largest artery in the abdominal cavity and it bifurcates, or splits into two branches, at the level of the fourth lumbar vertebra (L4). This split forms the two common iliac arteries, which further divide into the internal and external iliac arteries. The bifurcation at L4 is an important landmark in the abdominal anatomy and is commonly used as a reference point for various medical procedures and assessments.

The average range for activated PTT is 25-35 seconds. This means that when the PTT (Partial Thromboplastin Time) test is performed, the normal range for the time it takes for blood to clot is between 25 and 35 seconds. If the result falls within this range, it indicates that the clotting process is functioning properly.

Gerota's fascia is the correct answer because it is a band of fibrous connective tissue that surrounds and supports the kidneys. It helps to hold the kidneys in place within the retroperitoneum, which is the area behind the abdominal cavity. Cooper's ligament is not related to the kidneys, Camper's fascia is a layer of fatty tissue in the abdominal wall, and linea alba is a fibrous structure in the midline of the abdomen.

The cerebral aqueduct is a narrow channel that connects the third ventricle to the fourth ventricle in the brain. It allows for the flow of cerebrospinal fluid, which helps to protect and nourish the brain and spinal cord. The other options listed, such as the anterior commissure, septum pellucidum, and fornix, are not directly involved in the communication between the third and fourth ventricles. Therefore, the correct answer is the cerebral aqueduct.

The HRCT image of the chest was most likely acquired with a section width of 1mm because a thinner section width allows for higher resolution and better visualization of small structures in the chest. This is particularly important in HRCT imaging, which is used to evaluate lung diseases such as interstitial lung disease, lung nodules, and pulmonary embolism. A section width of 1mm provides more detailed and accurate images, helping in the detection and characterization of these conditions.

The correct answer is 1.25 mm or less. When performing a computed tomography angiography (CTA) of the renal arteries, a section width of 1.25 mm or less is recommended. This narrow section width allows for better visualization and detailed imaging of the renal arteries, which are small blood vessels supplying the kidneys. A narrower section width helps to capture more precise images, enabling the detection of any abnormalities or blockages in the renal arteries.

Lead shielding and the use of a needle holder can both be used to reduce occupational radiation exposure during the use of CT fluoroscopy for guided interventional procedures. Lead shielding can be used to block or attenuate radiation, reducing the amount of radiation that reaches the operator. Using a needle holder can help to minimize the operator's exposure by allowing for more precise and controlled needle placement, reducing the need for repeated exposures. Increased kVp, on the other hand, is not a technical consideration that can reduce occupational radiation exposure in this context.

High spatial frequencies in a CT image represent areas that contain abrupt changes in tissue density. Spatial frequency refers to the rate at which the intensity of the image changes as a function of position. In CT imaging, high spatial frequencies indicate rapid changes in tissue density, such as the boundaries between different tissues or structures. These abrupt changes in density are electronically represented in the CT image using high spatial frequencies.

The full width at half maximum (FWHM) of a CT scanner refers to the width of the peak of a spatial resolution curve where the intensity is at half of its maximum value. It is a measure of how well the scanner can distinguish between two closely spaced objects or details in an image. Therefore, the FWHM is used to describe the spatial resolution of a CT scanner, which is its ability to accurately represent the spatial details of an object or structure in the image.

The liver has a dual blood supply, meaning it receives blood from two different sources. The portal vein is responsible for supplying 75% of the liver's blood. The portal vein carries nutrient-rich blood from the digestive system, including the stomach, intestines, and spleen, to the liver. This blood contains absorbed nutrients and substances that need to be processed by the liver. The remaining 25% of the liver's blood supply comes from the hepatic artery, which carries oxygen-rich blood from the heart.

Overbeaming refers to the process of expanding the primary beam beyond the physical extent of the detector array in order to uniformly expose the entire array in an MDCT system. This technique ensures that all parts of the detector receive an equal amount of radiation, resulting in accurate and consistent image reconstruction.

Ionic contrast media are salts consisting of sodium and/or meglumine.

Interpolation is the mathematical technique used to reconstruct motion-free images from helically acquired CT data. It involves estimating the values of data points within a given range based on the values of known data points. In the context of CT imaging, interpolation helps in filling in the missing data points caused by the helical acquisition process, resulting in a complete and accurate image reconstruction. Convolution, radon transformation, and Fourier reconstruction are not specifically related to the reconstruction of motion-free images from helically acquired CT data.

A saline flush immediately following IV administration of iodinated contrast material has several advantages. Firstly, it can help reduce the required contrast agent dose, which can be beneficial in patients who may be at risk for adverse reactions or have limited renal function. Secondly, it can reduce the incidence of contrast-induced nephrotoxicity (CIN), a potential complication of contrast administration that can cause kidney damage. Lastly, it can help reduce streaking artifact from dense contrast agent in the vasculature, which can improve the quality of imaging studies. Therefore, all three options (1, 2, and 3) are correct.

The cone beam artifact is unique to multislice CT (MSCT) systems. This artifact occurs when the x-ray beam used in CT scanning is not collimated properly, resulting in a cone-shaped beam that diverges as it passes through the patient. This can lead to streaking or blurring of the image, particularly in areas where the patient's body is thicker or denser. Other image artifacts mentioned in the options, such as step artifact, aliasing artifact, and out-of-field artifact, can occur in both single-slice and multislice CT systems.

To improve the quality of multiplanar reformation (MPR) images, CT sections should be reconstructed with a 50% overlap. This means that each section will have 50% of its content repeated in the adjacent sections. By having this overlap, it allows for a smoother and more accurate reconstruction of the images in multiple planes, enhancing the overall quality of the MPR images.

Retrospective image reconstruction refers to the process of reconstructing images from previously acquired scan data. In single-slice CT systems, it is possible to change the algorithm, matrix size, and DFOV during retrospective image reconstruction. This allows for adjustments in image quality, resolution, and field of view. However, the slice thickness and SFOV cannot be changed retrospectively. These parameters are determined during the initial scan and cannot be altered during image reconstruction. Therefore, the statement that the slice thickness and SFOV may be changed is false.

The maximum number of sections the system can acquire with each rotation of the gantry is 16. This is because the MSCT system has a 16-slice configuration, meaning it has 16 detectors that can simultaneously acquire images. Each detector ranges in size from 0.625 to 1.25mm. Therefore, with each rotation of the gantry, the system can acquire images for all 16 detectors, resulting in a maximum of 16 sections.

Kerma stands for Kinetic Energy Released in Matter. It is the amount of x-ray energy that is transferred to a material, in this case, air. Kerma is used to measure the amount of energy absorbed by a substance when exposed to x-rays. It is an important parameter in radiation protection and is used to assess the potential biological effects of radiation exposure.

Spondylolisthesis is a degenerative condition where an upper vertebral body slips forward over a lower vertebral body. This can occur due to various factors such as aging, trauma, or genetic predisposition. Spondylolysis refers to a stress fracture in the vertebrae, herniated nucleus pulposus is a condition where the soft center of a spinal disc pushes through a crack in the outer layer, and spinal stenosis is the narrowing of the spinal canal. However, only spondylolisthesis involves the forward slipping of a vertebral body, making it the correct answer.

During the cardiac cycle, the heart goes through systole (contraction) and diastole (relaxation) phases. The R-R interval represents the time between two consecutive ventricular contractions. In this case, the heart muscle is in diastole (relaxation) during the 55-75% portion of the R-R interval. This means that the heart is not actively contracting during this time and is instead filling with blood in preparation for the next contraction.

To accurately demonstrate mediastinal lymphadenopathy during a CT study of the chest, an iodinated contrast agent needs to be injected intravenously. This is because the contrast agent helps highlight the lymph nodes in the mediastinum, which is the area between the lungs. By injecting the contrast agent, it becomes easier to identify and evaluate any abnormalities or enlargement of the lymph nodes in this region. This technique is commonly used to diagnose and monitor conditions such as lymphoma, tuberculosis, or metastatic cancer that may affect the lymph nodes in the chest.

The contrast resolution of a CT scanner refers to its ability to distinguish between different shades of gray in an image. It is influenced by factors such as section width, reconstruction algorithm, and signal-to-noise ratio. However, the focal spot size of a CT scanner does not directly affect the contrast resolution. The focal spot size primarily affects the spatial resolution, which refers to the ability to distinguish between small details in an image. Therefore, the correct answer is focal spot size.

Changing to a small focal spot size and acquiring 2.5mm sections would both serve to increase the spatial resolution of a CT exam. A smaller focal spot size allows for more precise imaging, resulting in higher resolution. Acquiring thinner sections (2.5mm instead of 5mm) also improves resolution by capturing more detailed information. Reconstructing images in a 320(2) matrix would not directly increase spatial resolution, as the matrix size refers to the number of pixels in the image and not the actual resolution.

Diatrizoate meglumine (Gastrografin), effervescent agents, and iopamidol (Isovue) can all be used as contrast media during CT evaluation of the gastrointestinal tract. Diatrizoate meglumine is commonly used to visualize the gastrointestinal tract and detect abnormalities. Effervescent agents, such as carbon dioxide tablets, can be used to distend the gastrointestinal tract and improve visualization. Iopamidol is another contrast agent that can be used to enhance the visibility of the gastrointestinal tract during CT scans. Therefore, options 1, 2, and 3 are all correct.

Axial CT images of the knee may be acquired in four separate series with gantry angulations of 0, 30, 45, and 60 degrees in order to demonstrate the patellofemoral joint. These different angles allow for a comprehensive evaluation of the patellofemoral joint, which is the joint between the patella (kneecap) and the femur (thigh bone). By acquiring images from different angles, the radiologist can assess the alignment, position, and any abnormalities or pathology in the patellofemoral joint. This helps in diagnosing conditions such as patellar instability, patellofemoral arthritis, and patellar maltracking.

The prone position may be used for a post myelogram CT examination of the lumbar spine in an effort to reduce metrizamide pooling. When the patient is in the prone position, gravity helps to prevent the contrast agent (metrizamide) from pooling in the lower lumbar region. This allows for a more even distribution of the contrast agent throughout the spinal canal, resulting in better visualization of the spinal structures during the CT examination.

An analytic form of image reconstruction refers to a method that directly calculates the reconstructed image from the acquired data without the need for iterative calculations. Fourier reconstruction and filtered back-projection are both examples of analytic techniques. Fourier reconstruction involves transforming the acquired data into the frequency domain using Fourier transform and then applying an inverse Fourier transform to obtain the reconstructed image. Filtered back-projection, on the other hand, involves filtering the acquired data and then back-projecting it to obtain the reconstructed image. Therefore, the correct answer is 2 and 3 only.

A fibroid tumor of the uterus is commonly referred to as a leiomyoma. Leiomyoma is a benign tumor that arises from the smooth muscle cells of the uterus. It is the most common type of tumor found in the female reproductive system. Fibroids can vary in size and may cause symptoms such as heavy menstrual bleeding, pelvic pain, and pressure on nearby organs. Treatment options for leiomyoma include medication, minimally invasive procedures, and surgery, depending on the severity of symptoms and desire for fertility preservation.

During contrast-enhanced CT examinations of the chest, streaking artifact may obscure portions of the superior mediastinum because of dense concentrations of iodine in the superior vena cava. This is because the superior vena cava is the major vein that carries deoxygenated blood from the upper body to the heart. When iodine, which is used as a contrast agent, is injected into the bloodstream, it can accumulate in the superior vena cava and cause streaking artifacts on the CT images. These artifacts can make it difficult to visualize certain structures in the superior mediastinum.