Intracranial aneurysm growth: consistency of morphological changes.

OBJECTIVE: Previous studies have shown a relation between growth and rupture of intracranial aneurysms. Additionally, several morphological characteristics are frequently measured to estimate rupture risk. Little is known about how the rupture risk is associated with morphological characteristic changes during growth. The aim of this study was to provide insights into how morphological characteristics, associated with rupture, change during an aneurysm's growth. METHODS: The authors retrospectively identified patients with longitudinal MRA images of unruptured growing aneurysms. The MRA images had an in-plane resolution of 0.2-0.5 mm and a slice thickness of 0.2-0.75 mm. Therefore, growth was defined as an increase of at least 0.5 mm in two directions or 1 mm in one direction. Using the MRA images, the authors semiautomatically segmented the aneurysm and the perianeurysmal vasculature. Twelve morphological characteristics were automatically measured. These characteristics were related to size (diameter, height, width, neck diameter, volume, surface area, aspect ratio, height-width ratio, and bottleneck factor) and shape (ellipticity index, nonsphericity index, and undulation index) of the aneurysm. Morphological characteristics before and after growth were compared using the Wilcoxon signed-rank test. RESULTS: The authors included 31 patients with 38 growing aneurysms. The aneurysms' growth was detected after a mean of 218 weeks (range 23-567 weeks). A significant increase was seen in all size-related characteristics, and the bottleneck factor also significantly increased (from a median of 1.00 [IQR 0.85-1.04] to 1.03 [IQR 0.93-1.18]), while the ellipticity index decreased (from a median of 0.26 [IQR 0.25-0.28] to 0.25 [IQR 0.24-0.26]). The changes in size ratios and shape indices varied largely among patients. Larger aneurysms more often showed an increase in shape ratios. CONCLUSIONS: Although aneurysm growth, size-related characteristics, bottleneck factor, and ellipticity index changed significantly during growth, most size ratios and shape indices showed inconsistent changes among aneurysms. This suggests that, for an accurate rupture prediction, morphological parameters need to be reassessed after growth.

Role modelling in the training of hospital-based medical specialists: a validation study of the Role Model Apperception Tool (RoMAT).

INTRODUCTION: Role modelling is a key component in the training of doctors that influences professional behaviour, identity and career choices. Clinical teachers and residents are often unaware of this, thereby risking transmission of negative behaviour. On the other hand, awareness positively affects role model behaviour. To assess role model behaviour, the Role Model Apperception Tool (RoMAT) was developed and validated in general practice training. The aim of the current study was to validate the RoMAT in the hospital-based training setting. METHODS: The authors asked first to last year residents, regardless of their specialty, to participate after written approval from their clinical teachers. The tool was completed online in 2017. The authors performed a principal component analysis and investigated internal consistency, construct validity, inter-rater reliability, known-groups comparisons and floor and ceiling effects. RESULTS: Of the 473 residents contacted, 187 (40%) completed the questionnaire. As in the primary validation study, the authors extracted two components: 'Caring Attitude' and 'Effectiveness', explaining 67% of the variation with a Cronbach's alpha of 0.94 and 0.93 respectively. Evidence for construct validity was found and there were no floor or ceiling effects, but inter-rater reliability was low. DISCUSSION: The RoMAT was internally consistent and valid to assess role model behaviour of the clinical teacher towards the resident in the hospital-based training of medical specialists. The poor inter-rater reliability, most likely due to homogeneous RoMAT responses, should be borne in mind when evaluating RoMAT scores on individual clinical teachers.