Assessment of the added value of the Twente Photoacoustic Mammoscope in breast cancer diagnosis\ud

Purpose: Photoacoustic (PA) imaging is a recently developed breast cancer imaging technique. In order to enhance successful clinical implementation, we quantified the potential clinical value of different scenarios incorporating PA imaging by means of multi-criteria analysis. From this analysis, the most promising area of application for PA imaging in breast cancer diagnosis is determined, and recommendations are provided to optimize the design of PA imaging. - \ud Methods: The added value of PA imaging was assessed in two areas of application in the diagnostic track. These areas include PA imaging as an alternative to x-ray mammography and ultrasonography in early stage diagnosis, and PA imaging as an alternative to Magnetic Resonance Imaging (MRI) in later stage diagnosis. The added value of PA imaging was assessed with respect to four main criteria (costs, diagnostic performance, patient comfort and risks). An expert panel composed of medical, technical and management experts was asked to assess the relative importance of the criteria in comparing the alternative diagnostic devices. The judgments of the experts were quantified based on the validated pairwise comparison technique of the Analytic Hierarchy Process, a technique for multi-criteria analysis. Sensitivity analysis was applied to account for the uncertainty of the outcomes. - \ud Results: Among the considered alternatives, PA imaging is the preferred technique due to its non-invasiveness, low cost and low risks. However, the experts do not expect large differences in diagnostic performance. The outcomes suggest that design changes to improve the diagnostic performance of PA imaging should focus on the quality of the reconstruction algorithm, detector sensitivity, detector bandwidth and the number of wavelengths used. - \ud Conclusion: The AHP method was useful in recommending the most promising area of application in the diagnostic track for which PA imaging can be implemented, this being early diagnosis, as a substitute for the combined use of x-ray mammography and ultrasonography

Rupture of the arterial wall causes deflection in pressure time course during ex vivo balloon angioplasty

A relation between restenosis and arterial lesions resulting from balloon angioplasty has been suggested in literature. Nevertheless, it is unclear to what extent angioplasty-induced arterial wall lesions contribute to the occurrence of restenosis. One problem is that arterial ruptures cannot be detected during balloon inflation. This study describes a method to detect ruptures in the arterial wall, based on deflections observable in the development of the balloonpressure. We performed ex vivo angioplasty with constant strain rate on 28 human femoral artery segments, showing deflections in 21 cases. In 20 cases wall rupture was confirmed histologically. From seven cases not showing deflections, four showed intact wall at microscopy. These figures result in a selectivity of the proposed method of 87 ± 7% and a predictive value of the positive test of 95 ± 5%. We conclude that this method can enhance detection of arterial rupture during ex vivo angioplasty and may become important clinically

Gender and Age Interact to Affect Early Outcome after Intracerebral Hemorrhage

BackgroundIntracerebral hemorrhage (ICH) is a common and devastating form of cerebrovascular disease. In ICH, gender differences in outcomes remain relatively understudied but have been examined in other neurological emergencies. Further, a potential effect of age and gender on outcomes after ICH has not been explored. This study was designed to test the hypothesis that age and gender interact to modify neurological outcomes after ICH.MethodsAdult patients admitted with spontaneous primary supratentorial ICH from July 2007 through April 2010 were assessed via retrospective analysis of an existing stroke database at Duke University. Univariate analysis of collected variables was used to compare gender and outcome. Unfavorable outcome was defined as discharge to hospice or death. Using multivariate regression, the combined effect of age and gender on outcome after ICH was analyzed. ResultsIn this study population, women were younger (61.1+14.5 versus 65.8+17.3 years, p=0.03) and more likely to have a history of substance abuse (35% versus 8.9%, p<0.0001) compared to men. Multivariable models demonstrated that advancing age had a greater effect on predicting discharge outcome in women compared to men (p=0.02). For younger patients, female sex was protective; however, at ages greater than 60 years, female sex was a risk factor for discharge to hospice or death.ConclusionWhile independently associated with discharge to hospice or death after ICH, the interaction effect between gender and age demonstrated significantly stronger correlation with early outcome after ICH in a single center cohort. Prospective study is required to verify these findings

In vitro measurement of the mechanical properties of atherosclerotic arleries before and after angioplasty

Long term success rate of percutaneous transluminal (coronary) angioplasty is limited by restenosis. Arterial lesions have been related to restenosis, although the nature of this relation is still unclear. Because the arterial wall structure has both elastic and viscous properties, we expect the mechanical behaviour of the arterial wall during angioplasty to be strain rate dependent. We here describe the results of our experiments to test the influence of strain rate on the strain at the moment of dissection during angioplast

A method to detect rupture of the arterial wall during balloon angioplasty

Restenosis limits the long-term success rate of Percutaneous Transluminal (Coronary) Angioplasty (PT(C)A) significantly. A relation between ruptures resulting from PT(C)A and restenosis has been suggested in literature. The authors developed a method to detect arterial lesions during the balloon inflation by measuring the pressure in the balloon. They state that a sudden drop in balloon pressure indicates an arterial rupture. Their preliminary results support this hypothesis in 92% of all cases. This method can be useful when investigating the relationship between modified PT(C)A procedures and occurrence of lesion