Evaluation of patient tissue selection methods for deriving equivalent density calibration for femoral bone quantitative CT analyses.

Osteoporosis affects an increasing number of people every year and patient specific finite element analysis of the femur has been proposed to identify patients that could benefit from preventative treatment. The aim of this study was to demonstrate, verify, and validate an objective process for selecting tissues for use as the basis of phantomless calibration to enable patient specific finite element analysis derived hip fracture risk prediction. Retrospective reanalysis of patient computed tomography (CT) scans has the potential to yield insights into more accurate prediction of osteoporotic fracture. Bone mineral density (BMD) specific calibration scans are not typically captured during routine clinical practice. Tissue-based BMD calibration can therefore empower the retrospective study of patient CT scans captured during routine clinical practice. Together the method for selecting tissues as the basis for phantomless calibration coupled with the post-processing steps for deriving a calibration equation using the selected tissues provide an estimation of quantitative equivalent density results derived using calibration phantoms. Patient tissues from a retrospective cohort of 211 patients were evaluated. The best phantomless calibration resulted in a femoral strength (FS) [N] bias of 0.069 ± 0.07% over FS derived from inline calibration and a BMD [kg/cm3] bias of 0.038 ± 0.037% over BMD derived from inline calibration. The phantomless calibration slope for the best method presented was within the range of patient specific calibration curves available for comparison and demonstrated a small bias of 0.028 ± 0.054 HU/(mg/cm3), assuming the Mindways Model 3 BMD inline calibration phantom as the gold standard. The presented method of estimating a calibration equation from tissues showed promise for CT-based femoral fracture analyses of retrospective cohorts without readily available calibration data.

The relationship between guardian certification requirements and guardian sanctioning: a research issue in elder law and policy.

This study investigated the relationship between guardian certification requirements and guardian sanctioning in the state of Washington. A total of 377 files were examined. Findings show that 52.4% of guardians with an undergraduate degree or higher education are likely to be sanctioned compared with 42.2% with an Associate of Arts (AA) or Technical (Tech) degree, and 36.9% with a high school diploma (HS) or equivalency (GED). Guardians with an undergraduate or higher education are 1.88 times more likely to be sanctioned compared with GED or HS graduates (p < 0.05). However, 83.3% of GED or HS graduates are likely to have more severe sanctions compared with 76.4% undergraduate or higher education, and 47.7% with an AA or Tech degree, respectively. Guardians with an AA or Tech degree are 0.28 times less likely to have more severe sanctions than guardians with an undergraduate degree or higher education (p < 0.01). The results are discussed with respect to guardian registration, licensing, certification and quality; licensing and regulation of other professions; the limitations of the study; and the need for further research.