The influence of contrast media on calcium-based imaging of the spine in dual-layer CT.

This study aimed to evaluate the impact of contrast media application on CT attenuation of the bone using a novel calcium-only imaging technique (VCa) from dual-layer spectral detector CT (DLCT), which enables CT-based bone mineral density measurement unimpeded by soft tissue components. For this, true non-contrast (TNC) and venous phase images (VP) of n = 97 patients were acquired. CT attenuation of the first lumbar vertebra (L1) was measured in TNC-VCa, VP-VCa, and in virtual non-contrast images (VNC). CT attenuation was significantly higher in VP-VCa than in TNC-VCa (p < 0.001), although regression analyses revealed a strong linear association between these measures (R2 = 0.84). A statistical model for the prediction of TNC-VCa CT attenuation was established (TNC-VCa[HU] = - 6.81 + 0.87 × VP-VCa[HU]-0.55 × body weight[kg]) and yielded good agreement between observed and predicted values. Furthermore, a L1 CT attenuation threshold of 293 HU in VP-VCa showed a sensitivity of 90% and a specificity of 96% for detecting osteoporosis. The application of contrast media leads to an overestimation of L1 CT attenuation in VCa. However, CT attenuation values from VP-VCa can be used within CT-based opportunistic osteoporosis screening eighter by applying a separate threshold of 293 HU or by converting measured data to TNC-VCa CT attenuation with the given regression equation.

Quantitative calcium-based assessment of osteoporosis in dual-layer spectral CT.

OBJECTIVES: To evaluate a novel calcium-only imaging technique (VCa) with subtracted bone marrow in osteoporosis in dual-layer CT (DLCT) compared to conventional CT images (CI) and dual-energy X-ray absorptiometry (DXA). MATERIAL AND METHODS: Images of a multi-energy CT phantom with calcium inserts, quantitative CT calibration phantom, and of 55 patients (mean age: 64.6 ± 11.5 years) were acquired on a DLCT to evaluate bone mineral density (BMD). CI, calcium-suppressed images, and VCa were calculated. For investigating the association of VCa and CI with DXA a subsample of 30 patients (<90 days between DXA and CT) was used. Multiple regression analysis was performed to identify further factors improving the prediction of DXA BMD. RESULTS: The calcium concentrations of the CT phantom inserts were significantly associated with CT numbers from VCa (R2 = 0.94) and from CI (R2 = 0.89-0.92). VCa showed significantly higher CT numbers than CI in the phantom (p ≤ 0.001) and clinical setting (p < 0.001). CT numbers from VCa were significantly associated with CI (R2 = 0.95, p < 0.001) and with DXA (R2 = 0.31, p = 0.007), whereas no significant association between DXA and CI was found. Prediction of DXA BMD based on CT numbers derived from VCa yielded R2 = 0.76 in multiple regression analysis. ROC for the differentiation of normal from pathologic BMD in VCa yielded an AUC of 0.7, and a cut-off value of 126HU (sensitivity: 0.90; specificity: 0.47). CONCLUSION: VCa images showed better agreement with DXA and known calcium concentrations than CI, and could be used to estimate BMD. A VCa cut-off of 126HU could be used to identify abnormal bone mineral density.

Single-center 10-year experience in the management of anterior abdominal wall defects.

BACKGROUND: Anterior abdominal wall defects can be managed with various techniques, since no one technique can be applied to all types of defects. The aim of this study is to present a single-center experience using biomaterials and evaluate the outcomes. METHODS: The clinical data obtained from 33 neonates (24 gastroschisis and 9 omphaloceles) managed for anterior abdominal wall defects at a single center from 1995 until 2005 were evaluated. RESULTS: Primary skin closure of the defect was possible in 22 (67%) cases; however, 4 of 22 (12%) required an inner patch. In seven (21%), two patches were employed. The grafts used were: seven (22%) Goretex, four (12%) dura and one (3%) bovine pericard. CONCLUSION: In our single-center experience, both synthetic (Goretex patches) and natural biomaterials (dura and bovine patches) were found to be alternatives to manage these defects. The advantages and disadvantages of the alternatives are presented.

Liver biopsy interpretation in chronic hepatitis.

Liver biopsy reports are very variable in their terminology. In this article, frequently used terms and 2 common scoring systems are described.

Third generation information systems: integrating costs and outcomes. Tools for professional development and program evaluation.

The authors present specific procedures for obtaining cost per closed case and a case outcome rating for each closed case, computer generated, yielding a cost-outcome report for single cases and aggregated cases. The procedures are illustrated with field data from an alcohol and drug addiction service. Cost per closed case is seen as the new unit cost datum. Combined with case outcome information, the cost-outcome report is seen as a promising new measure of efficiency. The potential of the cost-outcome report as a new basis for professional self-development, increased treatment effectiveness, and program evaluation is discussed.

Funding human services: fixed utility versus fixed budget.

It is argued in this paper that government allocations for human services based on inputs rather than outcomes, reduce efficiency in social and health service provision. An alternative system of budgeting or contracting on the basis of cost-per-closed case and case outcome is discussed. An interdependency between fixed budget and fixed utility models of allocation is affirmed. The locus of decision-making for operationalizing this interdependency is seen as the program and budget review panel to which operating agencies and government departments must submit financial and program accounting information from year to year. In isolation, the fixed budget approach degenerates into routine allocation or contract renewal with a focus on such input and output variables as volume of service and unit cost, and the fixed utility approach, into political stalemate. Simulated examples are given to demonstrate how allocation on the basis of inputs and outputs alone provides an incentive to inefficiency, and a fixed utility orientation to efficiency.

Characterization of plasmids in a sucrose-fermenting strain of Escherichia coli.

A multiply drug-resistant strain of Escherichia coli isolated from a patient in Bangladesh was shown to carry four types of plasmids based on size differences. One type carries a gene or genes for sucrose fermentation.