Exam 13: Special Considerations on Safety in Computed Tomography and Mammography

For routine head and body computed tomography examinations,effective doses fall into which of the following effective dose ranges?

DLP represents the product of the CTDIVOL and the irradiated scan length.In what unit of measure is it usually expressed?

The movement or advancement of the patient couch is known as

In spiral image acquisition,the patient table moves during the acquisition so that a

In the early 2000s various publications calculated individual and population risks of cancer from CT based upon risk estimates from studies of which of the following groups of people?

Tube current modulation in CT scanning can

Lower tube current is used in anatomic regions where there is ____________ attenuation because the anatomy is ____________ or _________ dense.

During mammography,axillary projections should be done only on request of the

______________ is the relationship between the movement or advancement of the patient couch and the x-ray beam collimator dimension.

Which of the following groups advocate annual mammography screening or mammography screening at least every other year? 1)American College of Radiology 2)American Cancer Society 3)American Medical Association

With higher radiation exposure to the patient during a computed tomography examination,there is

In CT when a series of adjacent slices is obtained,some radiation will also scatter from the slice being made into the adjacent slices.What is this radiation called?

A miscentering of ________ can produce as much as __________% increase in patient dose.

Filtering refers to changing the projection data before doing the back projections to remove the

In CT because of higher effective energy of the x-ray beam,both ____________ and _______________ interactions contribute substantially to the image.

Verifying that the center of the patient coincides with the center of the CT gantry is a significant part of dose reduction strategies that is under the control of the

In computed tomography the dose at the edge of a beam does not decrease to _________ immediately.

Which of the following are relevant dose parameters in CT? 1)CT dose index (CTDI) 2)CTDIw 3)CTDIVOL 4)Dose length product (DLP)

The entrance exposure from a CT examination may be compared with the entrance exposure received during which of the following procedures?

Which of the following is not typically used during a CT scan? 1)A tightly collimated x-ray beam 2)Direct patient shielding 3)Filtered back projection