title: Computed digital absorptiometry for measurement of phalangeal bone mineral mass on a slot-scanning digital radiography system.
abstract: Computed digital absorptiometry is a low-cost and low-radiation technique for rapid measurement of phalangeal bone mineral mass. We implement and evaluate this technique on a slot-scanning radiography system. Results, based on measurements of excised phalangeal bones, indicate that the technique has potential for use in clinical assessment of osteoporosis.
  
  
  BACKGROUND
  The current gold standard method for bone assessment in the diagnosis of osteoporosis requires specialised and expensive machines, highly trained personnel to conduct the examination and is available only at specialist centres. The technique, termed dual-energy X-ray absorptiometry (DXA), involves taking a bone mineral density measurement at the femur or lumbar spine. Measurements of bone at peripheral sites such as the phalanges using DXA and other techniques have been shown to have potential use in the diagnosis of osteoporosis. Computed digital absorptiometry (CDA) is a low-cost, low-radiation radiographic technique for assessing phalangeal bone mineral mass. It uses an aluminium step wedge as a calibration device to compute bone mineral mass in units of equivalent aluminium thickness. In this study, we assess the feasibility of using CDA on a slot-scanning radiography system for measuring phalangeal bone mineral mass.
  
  
  METHODS
  We implement and evaluate fully automated computed digital absorptiometry (CDA) of the middle phalanx of the middle finger on a slot-scanning radiography system.
  
  
  RESULTS
  The ash weight of incinerated bones was measured and shown to have a correlation of 0.92 with CDA-derived bone mineral mass. CDA measurements had a coefficient of variation of 0.26%, indicating high precision.
  
  
  CONCLUSIONS
  We conclude, based on these results, that CDA on a slot-scanning radiography machine may be useful for clinical assessment of osteoporosis.
authors.affiliation: MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Dendere
authors.forename: S P
authors.initials: SP
authors.lastname: Whiley
authors.forename: T S
authors.initials: TS
authors.lastname: Douglas
mesh_terms: D015502:Absorptiometry, Photon / Q000295:instrumentation / Q000379:methods*; D015519:Bone Density / Q000502:physiology*; D002138:Calibration; D005240:Feasibility Studies; D050278:Finger Phalanges / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000503:physiopathology