RTBC - Lumbar Spine, Sacrum, and Coccyx
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Routine frontal lumbar spine images are typically performed with the patient in which of the
following positions?
1) supine on table with knees flexed
2) supine on table with knees extended
3) prone on table with knees extended
4) erect at upright image receptor (IR) - CORRECT ANSWER -1
Flexing the knees when performing an AP lumbosacral spine x-ray has which two of the
following benefits? (select two)
1) results in more consistent brightness levels across the length of the spine
2) ensures patient comfort reducing the chance of motion
3) straightens the curve of the spine and places it closer to the IR
4) enhances the natural curve of the spine - CORRECT ANSWER - 2 and 3
Why is the lateral lumbar spine radiograph taken with the patient holding the breath in
expiration?
1) it reduces the superimposition of the costophrenic angles and the first lumbar vertebra
2) it is easier for the patient when in the lateral position
3) it allows more accurate superimposition of the iliac crests
4) it results in a more even brightness level of the lower lumbar spine - CORRECT
ANSWER -1
When performing a right posterior oblique (RPO) lumbar spine radiograph, the body should be
rotated so that the midsagittal plane (MSP) forms what degree of angulation with the image
receptor (IR)?
1) 25 degrees
, 2) 30 degrees
3) 45 degrees
4) 70 degrees - CORRECT ANSWER -3
Where should the central ray enter for a right posterior oblique (RPO) of the lumbar spine?
1) 2 inches medial to the left anterior superior iliac spine (ASIS) and 1 inch inferior to the iliac
crest
2) 2 inches medial to the right anterior superior iliac spine (ASIS) at the level of the iliac crest
3) 2 inches medial to the left anterior superior iliac spine (ASIS) and 1.5 inches superior to the
iliac crest
4) 2 inches superior to the right anterior iliac spine (ASIS) - CORRECT ANSWER -3
When performing a lateral lumbar spine on a patient with a wide pelvis and a narrow waist,
which of the following should be done?
1) a sponge should be placed under the patient's hip to prevent rotation
2) the central ray should be angled 5-8 degrees cephalad
3) a sponge should be placed under the waist to ensure the entire spine is parallel to the image
receptor
4) the patient should straighten the knees and slightly arch the back - CORRECT
ANSWER -3
Which of the following statements is TRUE regarding positioning for a lateral lumbar spine?
1) the central ray enters at the level of the anterior iliac spine (ASIS)
2) the central ray is angled 5-8 degrees caudad
3) the central ray is angled 5-8 degrees caudad
4) a pillow should be placed under the patient's dependent shoulder - CORRECT
ANSWER -2
What is the correct central ray orientation for a localized lateral of the L5-S1 vertebrae, if the
spine cannot be positioned horizontally?
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Routine frontal lumbar spine images are typically performed with the patient in which of the
following positions?
1) supine on table with knees flexed
2) supine on table with knees extended
3) prone on table with knees extended
4) erect at upright image receptor (IR) - CORRECT ANSWER -1
Flexing the knees when performing an AP lumbosacral spine x-ray has which two of the
following benefits? (select two)
1) results in more consistent brightness levels across the length of the spine
2) ensures patient comfort reducing the chance of motion
3) straightens the curve of the spine and places it closer to the IR
4) enhances the natural curve of the spine - CORRECT ANSWER - 2 and 3
Why is the lateral lumbar spine radiograph taken with the patient holding the breath in
expiration?
1) it reduces the superimposition of the costophrenic angles and the first lumbar vertebra
2) it is easier for the patient when in the lateral position
3) it allows more accurate superimposition of the iliac crests
4) it results in a more even brightness level of the lower lumbar spine - CORRECT
ANSWER -1
When performing a right posterior oblique (RPO) lumbar spine radiograph, the body should be
rotated so that the midsagittal plane (MSP) forms what degree of angulation with the image
receptor (IR)?
1) 25 degrees
, 2) 30 degrees
3) 45 degrees
4) 70 degrees - CORRECT ANSWER -3
Where should the central ray enter for a right posterior oblique (RPO) of the lumbar spine?
1) 2 inches medial to the left anterior superior iliac spine (ASIS) and 1 inch inferior to the iliac
crest
2) 2 inches medial to the right anterior superior iliac spine (ASIS) at the level of the iliac crest
3) 2 inches medial to the left anterior superior iliac spine (ASIS) and 1.5 inches superior to the
iliac crest
4) 2 inches superior to the right anterior iliac spine (ASIS) - CORRECT ANSWER -3
When performing a lateral lumbar spine on a patient with a wide pelvis and a narrow waist,
which of the following should be done?
1) a sponge should be placed under the patient's hip to prevent rotation
2) the central ray should be angled 5-8 degrees cephalad
3) a sponge should be placed under the waist to ensure the entire spine is parallel to the image
receptor
4) the patient should straighten the knees and slightly arch the back - CORRECT
ANSWER -3
Which of the following statements is TRUE regarding positioning for a lateral lumbar spine?
1) the central ray enters at the level of the anterior iliac spine (ASIS)
2) the central ray is angled 5-8 degrees caudad
3) the central ray is angled 5-8 degrees caudad
4) a pillow should be placed under the patient's dependent shoulder - CORRECT
ANSWER -2
What is the correct central ray orientation for a localized lateral of the L5-S1 vertebrae, if the
spine cannot be positioned horizontally?
