CT Attenuation of Acute Subdural Hematomas in Patients with Anemia.

Background And Purpose: Isodense and hypodense acute subdural hematomas have been reported in the literature in anemic patients. The purpose of this study is to see if there is a statistically significant difference between the Hounsfield unit measurements of acute subdural hematomas in anemic and nonanemic patients.

Methods: A total of 109 patients were analyzed.

Correlation of the Strength of Recommendations for Additional Imaging to Adherence Rate and Diagnostic Yield.

Purpose: The aim of this study was to evaluate the association between the wording of radiologist recommendations for chest CT with the likelihood of recommendation adherence and the diagnostic yield of the recommended follow-up CT imaging.

Methods: This HIPAA-compliant retrospective study had institutional review board approval, including waiver of the requirement for patient consent. All outpatient chest radiographic (CXR) studies performed at a tertiary care academic medical center in 2008 (n = 29,138) were searched to identify examinations with recommendations for chest CT.

Does CT-based Rigidity Analysis Influence Clinical Decision-making in Simulations of Metastatic Bone Disease?

Background: There is a need to improve the prediction of fracture risk for patients with metastatic bone disease. CT-based rigidity analysis (CTRA) is a sensitive and specific method, yet its influence on clinical decision-making has never been quantified.

Questions/purposes: What is the influence of CTRA on providers' perceived risk of fracture? (2) What is the influence of CTRA on providers' treatment recommendations in simulated clinical scenarios of metastatic bone disease of the femur? (3) Does CTRA improve interobserver agreement regarding treatment recommendations?

Methods: We conducted a survey among 80 academic physicians (orthopaedic oncologists, musculoskeletal radiologists, and radiation oncologists) using simulated vignettes of femoral lesions presented as three separate scenarios: (1) no CTRA input (baseline); (2) CTRA input suggesting increased risk of fracture (CTRA+); and (3) CTRA input suggesting decreased risk of fracture (CTRA-).

Improving education for the management of contrast reactions: an online didactic model.

Purpose: Radiologists could improve their knowledge of contrast reaction management. The aim of this study was to evaluate to what degree the implementation of a didactic module resulted in improved technologist, nurse, and physician knowledge and comfort levels regarding the appropriate management of adverse reactions to contrast media.

Methods: After institutional review board approval was obtained, nurses, technologists, and physicians involved in contrast administration were required to complete the educational module.

Further improvements on the factors affecting bone mineral density measured by quantitative micro-computed tomography.

The effects of imaging parameters and special configuration of objects within the reconstruction space on the micro computed tomography (μCT) based mineral density have been explored, and a series of density correction curves have been presented. A manufacturer-provided calibration phantom (0, 100, 200, 400, 800 mg HA/cm(3)) was imaged at all possible imaging conditions (n=216) based on energy, resolution, vial diameter, beam hardening correction factor and averaging. For each imaging condition, a linear regression model was fitted to the observed versus expected densities, and the intercepts (β(0)) and slopes (β(1)) of the regression lines and each density level were modeled using multiple regression modeling.

Non-invasive assessment of failure torque in rat bones with simulated lytic lesions using computed tomography based structural rigidity analysis.

This study applies CT-based structural rigidity analysis (CTRA) to assess failure torque of rat femurs with simulated lytic defects at different locations (proximal and distal femur) and diameters (25% and 50% of the cross-section at the site), and compared the results to those obtained from mechanical testing. Moreover, it aims to compare the correlation coefficients between CTRA-based failure torque and DXA-based aBMD versus actual failure torque. Twenty rats were randomly assigned to four equal groups of different simulated lesions based on size and location.

Increasing the appropriateness of outpatient imaging: effects of a barrier to ordering low-yield examinations.

Purpose: To determine the effect of a computerized radiology order entry system rule that prevented nonclinician support staff from completing orders for outpatient computed tomographic, magnetic resonance imaging, and nuclear medicine examinations that received initial low-yield decision support scores in the order entry system.

Materials And Methods: This retrospective HIPAA-compliant study was approved by the institutional review board; the requirement for informed consent was waived. The control group consisted of 42737 consecutive orders for examinations in which decision support was provided that were placed from April to December 2006.

Compressive axial mechanical properties of rat bone as functions of bone volume fraction, apparent density and micro-ct based mineral density.

Mechanical testing has been regarded as the gold standard to investigate the effects of pathologies on the structure-function properties of the skeleton. With recent advances in computing power of personal computers, virtual alternatives to mechanical testing are gaining acceptance and use. We have previously introduced such a technique called structural rigidity analysis to assess mechanical strength of skeletal tissue with defects.

An improved method to assess torsional properties of rodent long bones.

Torsion is an important testing modality commonly used to calculate structural properties of long bones. However, the effects of size and geometry must be excluded from the overall structural response in order to compare material properties of bones of different size, age and species. We have developed a new method to analyze torsional properties of bones using actual cross-sectional information and length-wise geometrical variations obtained by micro-computed topographic (microCT) imaging.