ARRT Bone Density Exam UPDATED
QUESTIONS AND CORRECT ANSWERS
According to the WHO criteria, what is the diagnosis of osteoporosis based on the measurement of
bone density? - CORRECT ANSWER 2.5 SD or more below the young adult peak bone
density
What is the gold standard technique for measuring bone density? - CORRECT ANSWER DXA
Cancellous bone is also know as? - CORRECT ANSWER Trabecular Bone
What is the anatomical landmark on the proximal femur that gives the best visual indication of the
degree of rotation of the proximal femur? - CORRECT ANSWER Lesser Trochanter
Which lumbar vertebra is described as having a characteristic shape of an X or and H on a DXA PA
spine scan? - CORRECT ANSWER L4
Is Forteo a bisphosphonate? - CORRECT ANSWER NO
Quantitative Computated Tomography (QCT) - CORRECT ANSWER -measurements are
volumetric
-trabecular bone can be isolated from cortical bone
-accuracy may be affected by marrow fat
Peripheral BMD measurements are advocated for _____________? - CORRECT ANSWER
Screening
What is the most important clinical consequence of osteoporosis? - CORRECT ANSWER
Fracture
,What is the name of the tool that integrates clinical information in a quantitative manner to predict a
10-year probability of major osteoporotic fracture for both men and women? - CORRECT ANSWER
FRAX
What is the major source of precision error in clinical practice? - CORRECT ANSWER
Technologist
What is the percentage of trabecular bone in the skeleton? - CORRECT ANSWER 20 %
The forearm is not used to monitor the effects of therapy for osteoporosis because....... - CORRECT
ANSWER rate of change in BMD is too slow
What site is mostly composed of cortical bone? - CORRECT ANSWER Proximal forearm
What are the advantages of QUS over x-ray methodologies for BMD measurement? - CORRECT
ANSWER -ultrasound is comparatively inexpensive
-patients are not subjected to ionizing radiation
-ultrasound exams are quick to perform
What is the name of the isotope that was used in SPA? - CORRECT ANSWER Iodine-125
What is the texture index that evaluates the pixel gray-level variations in lumber spine DXA images? -
CORRECT ANSWER TBS (Trabecular Bone Score)
When does type 2 primary osteoporosis generally occur? - CORRECT ANSWER after age 70
What technique used images of the hand and an aluminum wedge? - CORRECT ANSWER RA
(Radiograhic Absorptiometry)
New bone is formed by the ___________? - CORRECT ANSWER osteoblasts
,Cancellous bone is also known as _______________? - CORRECT ANSWER Trabecular bone
How would you start labeling the vertebral bodies on a PA lumbar scan? - CORRECT ANSWER
Start at L4 and count/label up
With changes in rotation of the femoral neck, what happens? - CORRECT ANSWER Increases
the BMD
If daily QC fails, what should be your first step of action? - CORRECT ANSWER -repeat the
scan
-if scan fails again, then call for help
Although the technology is similar with all of the DXA units, the BMD results are different
because.......... - CORRECT ANSWER -different calibration standards
-algorithms to calculate BMD
-differences in the ROI
-different databases
The primary mechanism of action of antiresorptive therapies is the direct interaction with the
__________________ - CORRECT ANSWER osteoclasts
Which site is preferred for determination of fracture prediction? - CORRECT ANSWER
proximal femur
What is one disease not associated with low BMD? - CORRECT ANSWER osteopetrosis
DXA results may be influenced by......... - CORRECT ANSWER -body thickness
, -degenerative changes
-fractures
-scan mode
A great forearm scan should include....... - CORRECT ANSWER -forearm centered
-forearm straight
-free of artifacts
Phantoms that mimic the shape and size of a skeletal region are called
______________________________. - CORRECT ANSWER anthromomorphic phantoms
What is the formula used to calculate BMD? - CORRECT ANSWER BMD = BMC/Area
How often should you perform the QA on the DXA unit? - CORRECT ANSWER everyday
you scan
Radiogammetry is the measurement of bones using skeletal x-rays/radiographs. Which site was often
used? - CORRECT ANSWER metacarpals
With voltage switching units, what type of calibration is used? - CORRECT ANSWER
continuous internal calibration--wheel or drum
For low energies, the most common process of absorption is the ________________________ effect.
- CORRECT ANSWER photoelectric
What are some comparisons to the amount of effective dose given during a central DXA scan? -
CORRECT ANSWER -less than a day of background radiation
QUESTIONS AND CORRECT ANSWERS
According to the WHO criteria, what is the diagnosis of osteoporosis based on the measurement of
bone density? - CORRECT ANSWER 2.5 SD or more below the young adult peak bone
density
What is the gold standard technique for measuring bone density? - CORRECT ANSWER DXA
Cancellous bone is also know as? - CORRECT ANSWER Trabecular Bone
What is the anatomical landmark on the proximal femur that gives the best visual indication of the
degree of rotation of the proximal femur? - CORRECT ANSWER Lesser Trochanter
Which lumbar vertebra is described as having a characteristic shape of an X or and H on a DXA PA
spine scan? - CORRECT ANSWER L4
Is Forteo a bisphosphonate? - CORRECT ANSWER NO
Quantitative Computated Tomography (QCT) - CORRECT ANSWER -measurements are
volumetric
-trabecular bone can be isolated from cortical bone
-accuracy may be affected by marrow fat
Peripheral BMD measurements are advocated for _____________? - CORRECT ANSWER
Screening
What is the most important clinical consequence of osteoporosis? - CORRECT ANSWER
Fracture
,What is the name of the tool that integrates clinical information in a quantitative manner to predict a
10-year probability of major osteoporotic fracture for both men and women? - CORRECT ANSWER
FRAX
What is the major source of precision error in clinical practice? - CORRECT ANSWER
Technologist
What is the percentage of trabecular bone in the skeleton? - CORRECT ANSWER 20 %
The forearm is not used to monitor the effects of therapy for osteoporosis because....... - CORRECT
ANSWER rate of change in BMD is too slow
What site is mostly composed of cortical bone? - CORRECT ANSWER Proximal forearm
What are the advantages of QUS over x-ray methodologies for BMD measurement? - CORRECT
ANSWER -ultrasound is comparatively inexpensive
-patients are not subjected to ionizing radiation
-ultrasound exams are quick to perform
What is the name of the isotope that was used in SPA? - CORRECT ANSWER Iodine-125
What is the texture index that evaluates the pixel gray-level variations in lumber spine DXA images? -
CORRECT ANSWER TBS (Trabecular Bone Score)
When does type 2 primary osteoporosis generally occur? - CORRECT ANSWER after age 70
What technique used images of the hand and an aluminum wedge? - CORRECT ANSWER RA
(Radiograhic Absorptiometry)
New bone is formed by the ___________? - CORRECT ANSWER osteoblasts
,Cancellous bone is also known as _______________? - CORRECT ANSWER Trabecular bone
How would you start labeling the vertebral bodies on a PA lumbar scan? - CORRECT ANSWER
Start at L4 and count/label up
With changes in rotation of the femoral neck, what happens? - CORRECT ANSWER Increases
the BMD
If daily QC fails, what should be your first step of action? - CORRECT ANSWER -repeat the
scan
-if scan fails again, then call for help
Although the technology is similar with all of the DXA units, the BMD results are different
because.......... - CORRECT ANSWER -different calibration standards
-algorithms to calculate BMD
-differences in the ROI
-different databases
The primary mechanism of action of antiresorptive therapies is the direct interaction with the
__________________ - CORRECT ANSWER osteoclasts
Which site is preferred for determination of fracture prediction? - CORRECT ANSWER
proximal femur
What is one disease not associated with low BMD? - CORRECT ANSWER osteopetrosis
DXA results may be influenced by......... - CORRECT ANSWER -body thickness
, -degenerative changes
-fractures
-scan mode
A great forearm scan should include....... - CORRECT ANSWER -forearm centered
-forearm straight
-free of artifacts
Phantoms that mimic the shape and size of a skeletal region are called
______________________________. - CORRECT ANSWER anthromomorphic phantoms
What is the formula used to calculate BMD? - CORRECT ANSWER BMD = BMC/Area
How often should you perform the QA on the DXA unit? - CORRECT ANSWER everyday
you scan
Radiogammetry is the measurement of bones using skeletal x-rays/radiographs. Which site was often
used? - CORRECT ANSWER metacarpals
With voltage switching units, what type of calibration is used? - CORRECT ANSWER
continuous internal calibration--wheel or drum
For low energies, the most common process of absorption is the ________________________ effect.
- CORRECT ANSWER photoelectric
What are some comparisons to the amount of effective dose given during a central DXA scan? -
CORRECT ANSWER -less than a day of background radiation
