Twenty-eight patients with prostatic carcinoma who underwent magnetic resonance (MR) imaging and subsequent radical prostatectomy were studied. The resected prostates were sectioned axially, and the ...whole-mount prostatic specimen was compared with the corresponding MR images. The carcinoma could be identified in 20 cases (71%), but the tumor volume was underestimated in 12 patients (43%). In 19 of 20 visualized cases (95%), the carcinoma was seen as an area of low signal intensity within the peripheral zone on T2-weighted images. However, in one case the signal intensity of the carcinoma was higher than that of the remainder of the peripheral zone. All carcinomas were located within the peripheral zone. The accuracy of MR imaging in the prediction of extraglandular tumor spread was 82%, with a sensitivity of 37.5% and a specificity of 100%. Nineteen patients (67%) exhibited histologically benign hyperplasia, which could be identified on MR images in 10 cases (53%). The signal intensities of the nodules varied. All areas of benign hyperplasia were located within the central zone. The location of the pathologic changes must therefore be considered in differential diagnosis.
Excellence By Design Furst, Peter G.
Professional safety,
04/2013, Letnik:
58, Številka:
4
Journal Article
Recenzirano
Safety by design (SBD) is a comprehensive approach to the entire project delivery process and addresses the safety of all people who work in, use and build buildings. Generally, four groups of people ...may be exposed to harm when working in/on, or using a facility: 1) the public who accesses structures; 2) employees who work in them; 3) employees who maintain these facilities; and 4) those who construct them. Various codes and standards are designed to address the risks of potential harm to these groups. For example, building and life safety codes ensure that people can exit structures safely during emergencies. Design professionals are required through licensing mandates and codes of ethics to ensure that these standards are utilized in the design of structures. To ensure this outcome, various jurisdictions have code checking and enforcement control of projects slated to be built. City fire marshals routinely inspect buildings to ensure that various safety requirements are maintained during operations.The safety of those working in these facilities is governed by OSHA 1910 standards. These general industry standards govern safety in relation-ship to work hazards, and they create the duty for employers to ensure that the work environment and work practices are in line with these standards. The expectation is that compliance will keep workers from harm while they perform their work. Construction worker safety is covered by OSHA 1926 standards. These standards aim to protect workers as they build a facility. Although these standards have been around for more than 40 years, construction workers continue to be injured and killed on work sites. These outcomes have initiated a search for a more effective way to address construction worker safety. Prevention through design (PTD), initiated by the International Labor Office (ILO, 1985), proposes that hazards should be "designed out" such that they are eliminated or reduced before workers are exposed to them. This will affect construction and maintenance workers. In the U.S., PTD was first initiated via a study sponsored by the Construction Industry Institute in the 1990s (Hinze & Gambatese, 1996). In 1995, the U.K. mandated PTD, which required designers to perform risk assessment of their design as it affected construction workers. Several other European nations and Australia have since mandated or strongly encouraged PTD.
Excellence By Design Furst, Peter G
Professional safety,
04/2013, Letnik:
58, Številka:
4
Journal Article
Recenzirano
Safety by design is a comprehensive approach to the entire project delivery process and addresses the safety of all people who work in, use and build buildings. Generally, four groups of people may ...be exposed to harm when working in/on, or using a facility: 1. the public who accesses structures, 2. employees who work in them, 3. employees who maintain these facilities, and 4. those who construct them. This article addresses the building process, which is complex. The process involves a large number of participating organizations that have unique goals, objectives, personnel, policies, practices and procedures that may or may not be in sync with those of the overall project. Initial assumptions on productivity and other factors that may or may not occur during a project's life cycle add a level of uncertainty. Collectively, these factors create a potential for variability and will influence the risk that will manifest itself during the project delivery process.
The degree of internal carotid stenosis has emerged as the most important predictor of ischemic stroke in extracranial carotid artery disease. The purpose of this study was to assess the validity of ...the noninvasive techniques for quantifying internal carotid stenosis with respect to the accepted standard of intra-arterial angiography.
We measured the maximum percentage reduction in luminal diameter on the intra-arterial digital subtraction angiograms of 56 symptomatic patients with extracranial internal carotid stenosis (n = 77) or occlusion (n = 20). These data were compared with independent measurements based on continuous-wave Doppler ultrasonography, pulsed-wave Doppler spectrum analysis, color Doppler-assisted duplex imaging, and magnetic resonance angiography.
Correlations with intra-arterial angiography were equally strong (r > .90) for magnetic resonance angiography, continuous-wave Doppler, and color duplex analysis. Positive and negative predictive values for (therapeutically relevant) 70% to 99% stenosis were higher for continuous-wave Doppler (.82, .97) and color duplex (.84, .98) than for magnetic resonance angiography (.79, .81). Also, accuracy in quantifying high-grade stenosis was better for both of these ultrasonographic techniques, mainly due to the frequent occurrence of a "flow gap" on the magnetic resonance angiograms. Continuous-wave Doppler and magnetic resonance angiography, but not color duplex, failed to detect slow residual arterial flow in one and two cases of symptomatic "pseudo-occlusion" of the internal carotid, respectively.
(1) Several noninvasive methods compare well with intra-arterial angiography in identifying and quantifying high-grade internal carotid stenosis; (2) the use of these noninvasive methods may suffice for treatment decisions; and (3) because residual between-method disagreement is partly explained by principles of physics, the validity of continuous-wave Doppler and color duplex in quantifying 60% to 99% stenosis is likely to be underestimated by correlation with intra-arterial angiography.
The aim of our study was to evaluate the usefulness of color duplex sonography to distinguish Graves' disease from diffuse toxic goiter. 24 patients with Graves' disease and 13 patients with diffuse ...toxic goiter underwent B-mode- and color duplex sonography of the thyroid gland. All patients had hyperthyroidism and elevated (99m)Tc-uptake. Spectral Doppler recordings were obtained at all thyroid arteries. Representative color flow maps of the thyroid gland were analyzed, calculating the percentage area of the thyroid gland, occupied by color pixels (color pixel density). The B-mode ultrasound pattern was subjectively assessed on a 4-point rating scale. In patients with Graves' disease the mean peak systolic velocity (PSV) (SD) was 110 (+/- 49) cm/s, the mean volume flow rate (VFR) was 123 ( +/- 67) ml/min and the mean color pixel density (CPD) was 33 (+/- 12) %. For patients with diffuse toxic goiter mean PSV (SD) was 43 ( +/- 9) cm/s (p < 0.001), mean VFR was 23 (+/- 10) ml/min (p < 0.001) and mean CPD was 9 (+/- 6) % (p = 0.007). CPD and spectral duplex recordings were positively correlated (CPD/PSV: rs = 0.77, CPD/VFR: rs = 0.75; p < 0.0001). No significant differences were observed concerning RI values. Sensitivity was 87% and specificity 92% for CPD and VFR and 87% and 100% for PSV. We conclude, that color duplex sonography can reliably distinguish diffuse toxic goiter from Graves' disease and therefore contributes significantly to the differential diagnosis of hyperthyroidism in diffuse thyroid disease.
We hypothesized that in patients with negative fluid-attenuated inversion recovery (FLAIR) images T(2) weighted fast spin-echo (FSE) images and T(1) weighted spin-echo (SE) images before and after ...intravenous administration of gadolinium-based contrast medium display no pathology either. Thus, we assessed the negative predictive value of FLAIR images to rule out MR-detectable brain lesions. 1026 consecutive cranial MR examinations were reviewed. Routine MRI of the brain included T(1) weighted coronal imaging before and after administration of gadopentetate dimeglumine, axial T(2) weighted FSE and fast-FLAIR imaging. The FLAIR images were rated by two radiologists into categories of 0 (without pathologic changes) and 1 (with pathologic changes). Two other radiologists analysed the complete examination. In 284 MR examinations of the brain no abnormalities were found (28%). FLAIR-ratings were false-negative in four cases and false-positive in 30 cases. Sensitivity and specificity of the FLAIR sequence for MR-detectable brain lesions were 99.5% and 89.4%. The unselective application of gadolinium avoided one false-negative MR-reading and improved the sensitivity of the MR-examination from 99.5% to 99.6%. Positive and negative predictive values were 96.1% and 98.4%, respectively. The interobserver reliability was kappa=0.93 for the FLAIR-readers and 0.89 for the readers who rated the complete examination. In conclusion, negative FLAIR images provide a high negative predictive value for MR-detectable brain lesions. Thus, in patients with negative FLAIR images the unselective application of gadolinium seems to be unnecessary.
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