Question 1

The success rate for CT percutaneous abscess drainage is reported to be:

Accepted Answer

The success rate for CT percutaneous abscess drainage is reported to be around 85%.

Question 2

A predetermined procedure is the definition for:

Accepted Answer

A predetermined procedure is specifically referred to as a protocol in the medical field. This term is used to describe a set of instructions or guidelines that medical professionals must follow when performing a particular test, procedure, or treatment.

Question 3

Submillimeter slice thicknesses are possible with multislice CT scanners.

Accepted Answer

Multislice CT scanners have the capability to produce submillimeter slice thicknesses.

Question 4

Which window widths are CT head scans viewed?

Accepted Answer

CT head scans are typically viewed using both the soft-tissue window and bony window settings. The soft-tissue window allows for visualization of the brain tissue, while the bony window is used to evaluate the skull and surrounding bone structures. The gray and white matter windows are usually not used for standard CT head scans.

Question 5

A lower pitch ratio such as a 2.0:1 ratio with slice overlap leads to a reduced patient dose.

Accepted Answer

A lower pitch ratio with slice overlap (i.e. slower table movement and greater overlap between adjacent slices) reduces the amount of radiation required to cover the same area, leading to a reduced patient dose.

Question 6

What is the chief disadvantage of CT colonography over conventional endoscopy?

Accepted Answer

The chief disadvantage of CT colonography is the inability to biopsy or remove polyps, which can be done during conventional endoscopy.

Question 7

How long is the catheter left in place following a percutaneous abscess drainage (PAD)procedure?

Accepted Answer

Typically, the catheter is left in place for 24 to 48 hours following a percutaneous abscess drainage (PAD) procedure. This allows for continued drainage of the abscess and also helps to prevent it from reforming.

Question 8

Volume acquisition CT slices cannot be reformatted as 3-D images.

Accepted Answer

Volume acquisition CT slices can be reformatted into 3-D images using specialized software and techniques.

Question 9

CT angiography (CTA)does not require the use of intravenous contrast media to demonstrate vascular structures.

Accepted Answer

CT angiography (CTA) does require the use of intravenous contrast media to demonstrate vascular structures.

Question 10

CT colonography has eliminated the need for the patient undergoing a bowel prep.

Accepted Answer

CT colonography still requires the patient to undergo a bowel prep, which includes a special diet and laxatives, to effectively visualize the colon.

Question 11

Which one of the following pathologic indications for a head CT is directly related to trauma?

Accepted Answer

A subdural hematoma is a type of bleeding that occurs outside the brain but within the skull, often resulting from trauma or injury to the head. Hydrocephalus, brain atrophy, and brain abscesses can have various causes and may not necessarily be related to trauma.

Question 12

CT fluoroscopy can obtain and display partially reconstructed images at a rate of _____ images per second.

Accepted Answer

CT fluoroscopy can obtain and display partially reconstructed images at a rate of 8 to 12 images per second.

Question 13

Hydrocephalus is caused by:

Accepted Answer

Hydrocephalus is caused by the blockage of the drainage of cerebrospinal fluid (CSF), which leads to an excess accumulation of CSF in the brain. This can be due to a range of factors such as congenital abnormality, infection, or tumor. Other options such as A, C, and D do not accurately describe the cause of hydrocephalus.

Question 14

Special filters can be used during CT fluoroscopy to reduce patient skin dose during biopsies.

Accepted Answer

Special filters, such as bowtie filters or flat filters, can be used during CT fluoroscopy to reduce patient skin dose during biopsies by selectively absorbing low energy photons that would otherwise contribute to skin dose.

Question 15

Typical slice thickness for a spine CT range is usually no greater than _____ mm.

Accepted Answer

The typical slice thickness for a spine CT range is usually no greater than 3 mm to ensure detailed visualization of the bony structures and soft tissues of the spine. Options B, C, and D are too thick for optimal imaging of the spine.

Question 16

Prospective electrocardiogram (ECG)gating used during cardiac CT permits the heart to be scanned:

Accepted Answer

Prospective ECG gating is performed during the diastole cycle, which is the period of time when the heart is in a relaxed state and the chambers are filling with blood. This allows for better image quality and reduces motion artifacts.

Question 17

Biopsies can be performed during a CT colonography.

Accepted Answer

Biopsies are not usually performed during a CT colonography. If any abnormalities are detected, a follow-up colonoscopy may be recommended for further investigation and potential biopsy.

Question 18

Which one of the following pitch ratios represents undersampling?

Accepted Answer

The answer of Which one of the following pitch ratios...

Question 19

A CT colonography requires the use of ________ as a contrast medium.

Accepted Answer

A CT colonography does not require the use of contrast medium. Instead, air is used to distend the colon for imaging purposes. Barium sulfate or iodinated rectal contrast may be used in a traditional barium enema or CT enterography, but not in a CT colonography.

Question 20

A collection of blood accumulating under the dura mater caused by trauma is termed:

Accepted Answer

A collection of blood accumulating under the dura mater caused by trauma is termed a subdural hematoma. A subarachnoid hemorrhage involves bleeding into the subarachnoid space. A glioma is a type of brain tumor that arises from the glial cells. A subdural abscess is a collection of pus that forms beneath the dura mater, usually due to infection.

Quiz 18: Computed Tomography