Exam 1: Guidelines for Image Analysis

Which guideline should be used to position the identification (ID) plate?

For an open joint space to be obtained, the central ray must be aligned _____ to the joint.

The following statements with regard to the spatial resolution in a DR system are true except 1)DR systems have spatial resolution capabilities of approximately 3.7 lp/mm. 2)spatial resolution is affected by the size of the DELs and the spacing between them. 3)changing the size of the exposure field (collimation) does not affect spatial resolution. 4)as the DELs become larger, the spatial resolution capability increases.

Good collimation practices will do all of the following except

The patient demographic requirements for radiographic images include all of the following except

The medial and lateral femoral condyles are not superimposed on a lateral knee projection. The larger, lateral condyle is 1 inch (2.5 cm) anterior to the medial condyle. The best way to correct this error is to

When displaying images acquired on a direct-indirect capture digital radiography system (DR), which of the following statements are true? 1)Patient orientation must be considered. 2)Diagonally obtained projections will be displayed vertically. 3)IR orientation must be considered. 4)The correct examination must be selected before exposing the IR.

The greatest detail sharpness is obtained by using 1)a small focal spot. 2)the longest SID. 3)the smallest OID. 4)longer exposure times.

The most common shape distortion is

All of the following statements with regard to an angled CR or divergent beams used to record an object are true except

Good collimation practices result in which of the following? 1)Reduces histogram analysis errors 2)Clearly delineates the VOI 3)Improves the visibility of recorded details by reducing the amount of scatter radiation that reaches the IR 4)Decreases the radiation dosage by limiting the amount of scatter from the patient

When imaging long bones, which of the following is (are) correct statements? 1)Choose a large enough IR so that one or both joints are included on the projection. 2)Extend the collimation field so it extends 1 to 2 inches (2.5 cm to 5 cm) beyond the joints spaces as required. 3)Histogram errors may occur if the system algorithm does not recognize a diagonal exposure field. 4)Align the long bone parallel to the IR to prevent a histogram analysis error.

Three images were obtained on the same structure with a computed radiography system. Image 1 was obtained using a 48-inch source-image receptor distance (SID) and a 5-inch object-image receptor distance (OID); image 2 was obtained using a 48-inch SID and a 3-inch OID; and image 3 was obtained with a 48-inch SID, a 3-inch OID, and a larger IR. Which image will demonstrate the greatest size distortion?

Three images were obtained on the same structure with a computed radiography system. Image 1 was obtained using a 48-inch source-image receptor distance (SID) and a 5-inch object-image receptor distance (OID); image 2 was obtained using a 48-inch SID and a 3-inch OID; and image 3 was obtained with a 48-inch SID, a 3-inch OID, and a larger IR. Which image will demonstrate the sharpest recorded detail?

Effective radiation protection practices include all of the following except 1)effective communication and immobilization devices. 2)maintaining minimum source to skin distances (SSD). 3)oscillating grids and contact shields. 4)collimation and minimizing technical factors.

The off-centered diverged beams of a perpendicular CR will affect structures in the same manner as an angled CR. Which of the following statements best describes this relationship? 1)At a 40-inch SID, the divergence of x-rays is 1 degree for every inch off-centered in any direction from the CR. 2)At a 48-inch SID, beam divergence is off-centered about 2 degrees for every inch in any direction from the CR. 3)At a 40-inch SID, the divergence of x-rays is 2 degrees for every inch off-centered in any direction from the CR. 4)At a 72-inch SID, beam divergence is off-centered about 1 degree for every inch.

What is the marker placement for the projection of PA cranium?

Two structures are 2.5 inches apart and out of superimposition 1.5 inches. To bring them into superimposition, the CR should be angled _____ degrees.

A rotating collimator head 1)can be rotated without rotating the entire tube column on DR systems. 2)does not affect the alignment of the beam with the grid. 3)allows the technologist to increase collimation on projections when the longitudinal axis of the anatomical structure is not aligned with the longitudinal or transverse axis of the IR. 4)should be avoided when using computed radiography because it may affect the exposure field recognition process.

When the central ray is angled, the structure situated _____ is projected the most.