ISCD CBDT study plan

Map the full CBDT exam blueprint into a one-page outline that lists every physics, anatomy, and quality-control topic you must cover

Define and correctly use core densitometry vocabulary: BMD, BMC, T-score, Z-score, areal vs volumetric density, precision, accuracy, and least significant change

Explain how DXA produces an image and a measurement, tracing the path from X-ray source through K-edge filters, patient attenuation, and detector to calculated bone mineral content

Describe the two X-ray energy spectra used in DXA and state why dual-energy subtraction isolates bone from soft tissue

Compare pencil-beam, fan-beam, and narrow fan-beam scanner designs on scan speed, dose, and magnification error

Calculate areal BMD from BMC and projected area, and explain why areal BMD depends on bone size and thickness

Identify the standard measurement sites (lumbar spine L1-L4, total hip, femoral neck, distal one-third radius) and justify when each is preferred

Interpret the manufacturer reference database concept and explain why T-score and Z-score use different reference populations

Explain how the WHO diagnostic categories are applied with T-scores and when a Z-score instead of a T-score is the appropriate reporting metric

List the artifacts that inflate or deflate spine BMD, including degenerative changes, aortic calcification, scoliosis, vertebral fracture, and prior surgery, and state the corrective action for each

List hip and forearm positioning errors and their effect on measured BMD

Describe how to verify scan analysis: check bone edges, exclude non-evaluable vertebrae, and confirm comparability with prior scans

Explain the components of precision assessment: short-term precision error, root-mean-square standard deviation, and least significant change

Compute the least significant change from a given precision error at the 95% confidence level and state what change counts as real

Design a phantom-based reproducibility protocol, including repeat scans, repositioning, and operator rotation

Describe daily quality-control procedures: phantom scanning, control charts, and action limits for drift

Describe radiation dose in DXA and compare it with other imaging modalities using effective dose figures

Explain the ALARA principle and the practical shielding, collimation, and scatter-reduction measures used in a DXA room

Outline the regulatory and accreditation expectations for equipment surveys, operator training, and quality-control documentation

Identify common equipment faults, such as detector drift, calibration failure, and table or arm movement, and the escalation path for each

Interpret serial BMD results correctly by applying least significant change and distinguishing real change from measurement noise

Explain the role of vertebral fracture assessment and trabecular bone score as adjuncts to BMD, including their limitations

Describe how body composition and pediatric or small-animal modes differ from standard adult scanning

Explain how medications and clinical conditions, such as glucocorticoid use, hyperparathyroidism, and renal disease, alter BMD interpretation

Complete a full timed practice exam under exam conditions and record your score by topic

Review every missed item and classify the error as knowledge gap, misread question, or calculation slip

Re-derive the formulas you are least confident with, including BMD, T-score, Z-score, and least significant change, from memory

Rehearse the artifacts and quality-control material you scored lowest on until you can explain it aloud without notes

Consolidate the highest-yield facts into a single condensed review sheet you can read in 30 minutes

Re-test only the topics flagged in your week-7 error log and confirm improvement

Practice explaining five dense concepts aloud as if teaching a new technologist

Simulate exam-day timing and confirm your logistics, including identification and appointment details