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Introduction: We developed a new shockroom resuscitation setting that includes a moveable, multislice computed tomography (CT) scanner capable of scanning patients during the initial trauma resuscitation phase without (multiple) patient transfers that previously were necessary. This enables us to perform a complete diagnostic trauma workup, without leaving the shockroom. In this study, we assess the effect of the new Trauma Workflow Concept on the initial diagnostic workup times in the trauma room., Materials: Data of 100 consecutive trauma patients were collected prospectively (2005 cohort) and compared with 100 consecutive trauma patients seen in our previous trauma resuscitation setting (2003 cohort). For all patients, time management was evaluated using video registration and complemented with electronic imaging times. Patients with and without CT scanning were compared with the effect of CT scanning on complete workup time, defined as time from admission to the trauma room to time of completion of diagnostic workup., Results: Patient demographics, including appliance of CT imaging were similar. Complete diagnostic workup for patients who underwent CT imaging took an average of 79 minutes (standard deviation +/- 29 minutes) in the 2005 cohort and 105 minutes (standard deviation +/- 48 minutes) in the 2003 cohort. Complete diagnostic workup without CT imaging took 56 minutes and 53 minutes for the 2005 and 2003 cohorts, respectively. There was no difference found for nonscanned patients, whereas there was a significant difference between 2005 and 2003 for scanned patients (p < 0.01)., Conclusion: Our new trauma workflow concept with a sliding CT scanner was significantly faster for completing the initial diagnostic workup, especially when CT imaging was required.

Rationale and Objectives: To understand normal bone development, studies in healthy children and adolescents are important. To assess the applicability of tibial quantitative ultrasound measurements (QUS) in children, we performed a study that compared dual-energy x-ray absorptiometry (DXA) of the lumbar spine and whole body with tibial QUS., Methods: For this study we recruited 146 Dutch children and adolescents, 58 boys (median age, 14.1 years; range, 7.6-23.4 years) and 88 girls (median age, 18.0 years; range, 7.6-23.5 years). Tanner stage, weight, and height were assessed for all participants. Bone mineral density (BMD; g x cm(-2)) of the whole body and lumbar spine (L2-L4) and bone mineral apparent density (BMAD) of the lumbar spine (g x cm(-3)) were assessed by using the Lunar DPXL. For tibial QUS, the Soundscan compact system was used., Results: Both lumbar as well as whole-body BMD showed a strong, significant correlation with tibial QUS in boys and girls: rtotal body boys = 0.81, rtotal body girls = 0.77, rlumbar spine boys = 0.79, and rlumbar spine girls = 0.72. Lumbar spine BMAD also showed significant correlations with tibial QUS: rboys= 0.63 and rgirls = 0.63 (for all correlations, P < 0.001)., Conclusions: Our study showing strong, significant correlations between DXA and tibial QUS measurements suggests that tibial QUS is a technique that may be applicable in children and adolescents.

Methods: The relation between geometry and the distribution of trabecular and cortical bone mass and density in the human femoral neck was evaluated with quantitative computed tomography (QCT). Quantitative computed tomography data were obtained from 2-mm thick computed tomography slices of 20 human femur necks in vitro. A standardized scan position in each femur was used with the smallest cross-section as reference point., Results: When trabecular bone mass (TrBM) and cortical bone mass were presented as percentage of total bone mass (ToBM), it was found that, starting at the cranial (head) side, ToBM consists of 78% TrBM. About 21% of ToBM can be found as TrBM at the caudal (trochanter) side. At the smallest cross-sectional volume TrBM is 33% of ToBM. For every 2-mm slice, an average decrease of 5% TrBM can be seen., Conclusions: These data show that geometry and bone mass distribution are related. Whereas total bone mass remains relatively stable, the cortical and trabecular bone mass changes extensively. This implies that QCT measurements in the femoral neck depend highly on midneck positioning.

Five postprocessing methods for dual-energy quantitative computed tomography of the vertebral body were evaluated theoretically. The methods were compared by transforming the original sets of equations to a standard set. Only two of these methods produced optimal results, namely the basic approach of Goodsitt et al and the method of Nickoloff et al. The calibration approach of Goodsitt et al will produce optimal results only if calibration materials are available that mimic the anatomic constituents of the vertebral body better than those available currently. Theoretically, the methods of Cann et al and of Laval-Jeantet et al will not produce optimal results.

Three facets of dual-energy quantitative computed tomography are studied: (1) the algorithm for postprocessing data (the methods of Cann, Laval-Jeantet et al, Goodsitt et al [two methods], and Nickoloff et al); (2) the influence of choice of tissue-equivalent materials for calibration; and (3) the difference between central and peripheral calibration. The different tissue-equivalent materials include bone mineral-equivalent (K2HPO4 solutions and calcium hydroxyapatite), fat-equivalent (liquid paraffin, polyethylene, and 70% ethanol solution), and red marrow-equivalent (plastic). Deviation from the manufacturer's quoted content is least with central positioning of the calibration materials. The accuracy of estimates is best when the same tissue-equivalent materials are used for calibration that are being measured. The deviations produced by the use of different tissue-equivalent materials indicate the importance of using materials that mimic the components of bone most closely. The two methods of Goodsitt et al and the method of Nickoloff et al produced the best results.