Computed Tomography-based evaluation of porcine cardiac dimensions to assist in pre-study planning and optimized model selection for pre-clinical research.

The pig (Sus Scrofa Domestica) is an accepted model for preclinical evaluation of prosthetic heart valves and trans-catheter implantation techniques. Understanding porcine cardiac dimensions through three-dimensional computed tomography (CT), increases preclinical study success, leading to higher cost efficiency and to the observance of the obligation to the 3 R principles. Cardiac CT images of twenty-four Swiss large white pigs were segmented; aortic root, mitral valve, pulmonary trunk, tricuspid valve, as well as the aorto-mitral angle and left atrial height were analyzed. Correlation coefficient (r) was calculated in relation to body weight. In Swiss large white pigs, valvular dimensions, length of the pulmonary artery and ascending aorta as well as left atrial height correlate with body weight. Coronary ostia heights and aorto-mitral angle size can be neglected in animal size selection; no changes were found for either of the two parameters with increasing body weight.

Quality of life of children with achondroplasia and their parents - a German cross-sectional study.

BACKGROUND: Achondroplasia is the most common form of disproportionate short stature and might affect not only the quality of life of the affected child but also that of the parents. OBJECTIVES: We aimed to investigate the quality of life of children with achondroplasia from child- and parent perspective as well as the parental quality of life. METHODS: Forty-seven children with achondroplasia and 73 parents from a German patient organization participated. We assessed children's quality of life using the generic Peds QL 4.0™ as self-reports for children aged 8-14 and parent-reports for children aged 4-14 years. Parental quality of life we assessed using the short-form 8-questionnaire. RESULTS: Children with achondroplasia showed significantly lower quality of life scores compared to a healthy reference population from both the child- and parent-report (p = ≤.01), except the child-report of the emotional domain (t (46) = - 1.73, p = .09). Parents reported significantly lower mental health in comparison with a German reference population (t (72) = 5.64, p ≤ .01) but no lower physical health (t (72) = .20, p = .85). While the parental quality of life was a significant predictor of parent-reported children's quality of life (F (6,66) = 2.80, p = .02), it was not for child-reported children's quality of life (F (6,66) = .92, p = .49). CONCLUSIONS: Achondroplasia is chronically debilitating. Thus special efforts are needed to address patients' and parent's quality of life needs. This special health condition may influence the daily life of the entire family because they have to adapt to the child's particular needs. Therefore, clinicians should not only focus on the child's quality of life but also those of the parents.

CT Angiography of the Aorta: Contrast Timing by Using a Fixed versus a Patient-specific Trigger Delay.

Background Optimal timing of the CT scan relative to the contrast media bolus remains a challenging task given the shorter scan durations of modern CT scanners, as well as interpatient variability. Purpose To compare contrast opacification in CT angiography of the aorta between a cohort with fixed trigger delay and a cohort with patient-specific individualized trigger delay for contrast media timing with bolus tracking. Materials and Methods In this prospective study (January-August 2018), CT angiography of the thoracoabdominal aorta with bolus tracking was performed in two different study cohorts: one with a fixed trigger delay of 4 seconds (fixed cohort) and one with a patient-specific trigger delay (individualized cohort). All CT and contrast media protocol parameters were kept identical among cohorts. Objective image quality was evaluated by one reader; two readers assessed subjective image quality. Student t test was used to test for differences in mean attenuation; the Wilcoxon-Mann-Whitney test was used to test for differences in noise, contrast-to-noise ratio, and subjective image quality. Results The fixed cohort had 108 study participants (16 women; mean age ± standard deviation, 72 years ± 10); the individualized cohort had 108 participants (16 women; mean age, 72 years ± 12). The trigger delay in the individualized cohort ranged from 6.4-11.3 seconds (mean, 9.2 seconds). There was higher overall attenuation in the individualized cohort than in the fixed cohort (486 HU ± 92 for individualized vs 438 HU ± 99 for fixed; P < .001), with increasing differences from the aortic arch (8 HU) to the iliac arteries (95 HU). The regression model indicated uniform attenuation in the individualized cohort and decreasing attenuation in the fixed cohort (decrease of 87 HU by the iliac arteries; P < .001). There was no difference between cohorts for image noise (20 vs 19; P = .41), but contrast-to-noise ratio (21 vs 19; P = .04) and subjective image quality were higher in the individualized cohort than in the fixed cohort (excellent or good image quality, 100% vs 67%; P < .001). Conclusion Compared with a fixed delay time after bolus tracking, a patient-specific individualized trigger delay improves image quality and provides uniform contrast attenuation for CT angiography of the aorta. ©RSNA, 2019.