BD exam guide
About the Bone Densitometry (BD) exam
The ARRT Bone Densitometry examination assesses safe patient care, DXA image production, and the acquisition and analysis of skeletal and body-composition studies. Strong preparation connects osteoporosis risk, anatomy, physics, quality control, positioning, analysis, and reporting rather than treating scan acquisition as an isolated skill.
MedPorium is an independent education platform and is not affiliated with or endorsed by The American Registry of Radiologic Technologists (ARRT). Exam details can change; confirm them with the official source before applying.
BD exam format at a glance
- Questions
- 105
- 75 scored; 30 unscored
- Time
- 105 minutes of test time within a 125-minute appointment
- Delivery
- Computer-based testing at Pearson VUE test centers
Knowledge to review for the BD exam
These foundations support the practical tasks in the official examination matrix.
Patient and bone-health foundations
- Osteoporosis risk factors, indications, contraindications, medical history, medicines, pregnancy screening, infection control, and communication
- Skeletal anatomy, bone biology, fracture risk, reference populations, T-scores, Z-scores, and clinical correlation
DXA systems and quality
- X-ray attenuation, detector and fan-beam principles, calibration, equipment operation, radiation protection, artifacts, and troubleshooting
- Quality control, phantom scanning, precision assessment, least significant change, cross-calibration, and reproducibility
Acquisition and analysis
- Lumbar spine, proximal femur, forearm, whole-body, vertebral fracture assessment, body composition, and pediatric or special-population studies
- Positioning, scan modes, regions of interest, vertebral and hip labeling, exclusions, serial comparison, and technical reporting
BD examination matrix
The percentages below are the approximate exam-score weights published by The American Registry of Radiologic Technologists (ARRT). Use them to allocate study time, then adjust for your own weak areas.
22.7%
Patient Care
Assess the patient, verify the examination, communicate effectively, and apply safety and professional-care principles.
- Review indication, history, fracture and osteoporosis risk, medicines, prior studies, and contraindications
- Identify and position the patient safely while applying infection control and radiation protection
- Explain the examination, respond to limitations, and document relevant clinical information
26.7%
Image Production
Apply DXA physics, instrumentation, radiation safety, quality control, and performance evaluation.
- Relate attenuation, beam geometry, detectors, calibration, and system operation to image and data quality
- Perform and interpret quality-control and phantom procedures
- Apply precision, reproducibility, least significant change, cross-calibration, artifact, and troubleshooting principles
50.6%
Procedures
The largest area covers DXA positioning, acquisition, analysis, special studies, and technical evaluation.
- Acquire and analyze lumbar spine, hip, forearm, and whole-body studies
- Perform vertebral fracture assessment and body-composition or special-population examinations
- Recognize positioning and analysis errors, artifacts, exclusions, and valid serial comparisons
How to use this BD diagnostic
The diagnostic samples all three current content areas. For each miss, identify whether the gap involved history and safety, DXA physics or quality control, positioning and acquisition, region-of-interest analysis, artifact recognition, precision, or interpretation support.
High-yield BD study priorities
Priority 1
Make procedures half of practice
Rehearse positioning, centering, acquisition, ROI placement, labeling, exclusions, and error correction for every common site.
Priority 2
Pair scores with clinical meaning
Distinguish T-score, Z-score, reference database, fracture risk, change over time, and when a result may be technically invalid.
Priority 3
Know precision, not just accuracy
Practise precision calculations, least significant change, reproducibility, calibration, and the effect of different systems or technologists.
Priority 4
Build an artifact checklist
Review hardware, degeneration, fracture, motion, contrast, positioning, anatomy, and analysis choices that can falsely alter density.
BD exam FAQ
How many questions are on the ARRT Bone Densitometry examination?
The current examination format contains 105 questions: 75 scored questions and 30 unscored pilot questions. Pilot questions are mixed into the examination and are not identified.
How long is the Bone Densitometry examination?
105 minutes of test time within a 125-minute appointment. ARRT's appointment time also includes the tutorial, nondisclosure agreement, and survey where applicable.
How is the content outline weighted?
The currently effective specification is approximately Patient Care 22.7%, Image Production 26.7%, Procedures 50.6%. These percentages are calculated from ARRT's scored-item counts, so rounding may prevent the displayed values from totaling exactly 100%.
What should I prioritize for Bone Densitometry?
Procedures is the largest scored content area at approximately 50.6%. Give it the largest share of practice, but continue sampling every area because the examination blueprint is broad.
What score is required to pass an ARRT examination?
ARRT reports examination results on a scaled score from 1 to 99, and a scaled score of 75 is required to pass. A 75 scaled score is not the same as answering 75% of questions correctly.
Does this diagnostic predict whether I will pass?
No. A 15-question diagnostic is a low-confidence baseline, not a validated pass prediction. Review every rationale and use larger mixed and content-specific sets to build a more stable readiness estimate.
Is MedPorium affiliated with ARRT?
No. MedPorium is an independent education platform and is not affiliated with or endorsed by The American Registry of Radiologic Technologists.
Review and official source
Clinical reviewer: K. R. Little
Exam format and matrix information were checked against the ARRT Bone Densitometry credential page and examination content specifications. Source reviewed October 15, 2026.
Ready to check your BD knowledge?
Take the free 15-question practice test to identify strengths and topics that need more review.