Dynamic Computed Tomography Angiography for capturing vessel wall motion:A phantom study for optimal image reconstruction

Background Reliably capturing sub-millimeter vessel wall motion over time, using dynamic Computed Tomography Angiography (4D CTA), might provide insight in biomechanical properties of these vessels. This may improve diagnosis, prognosis, and treatment decision making in vascular pathologies. Purpose The aim of this study is to determine the most suitable image reconstruction method for 4D CTA to accurately assess harmonic diameter changes of vessels. Methods An elastic tube (inner diameter 6 mm, wall thickness 2 mm) was exposed to sinusoidal pressure waves with a frequency of 70 beats-per-minute. Five flow amplitudes were set, resulting in increasing sinusoidal diameter changes of the elastic tube, measured during three simulated pulsation cycles, using ECG-gated 4D CTA on a 320-detector row CT system. Tomographic images were reconstructed using one of the following three reconstruction methods: hybrid iterative (Hybrid-IR), model-based iterative (MBIR) and deep-learning based (DLR) reconstruction. The three reconstruction methods where based on 180 degrees (half reconstruction mode) and 360 degrees (full reconstruction mode) raw data. The diameter change, captured by 4D CTA, was computed based on image registration. As a reference metric for diameter change measurement, a 9 MHz linear ultrasound transducer was used. The sum of relative absolute differences (SRAD) between the ultrasound and 4D CTA measurements was calculated for each reconstruction method. The standard deviation was computed across the three pulsation cycles. Results MBIR and DLR resulted in a decreased SRAD and standard deviation compared to Hybrid-IR. Full reconstruction mode resulted in a decreased SRAD and standard deviations, compared to half reconstruction mode. Conclusions 4D CTA can capture a diameter change pattern comparable to the pattern captured by US. DLR and MBIR algorithms show more accurate results than Hybrid-IR. Reconstruction with DLR is &gt;3 times faster, compared to reconstruction with MBIR. Full reconstruction mode is more accurate than half reconstruction mode.</p

Paediatric patients report lower health-related quality of life in daily clinical practice compared to new normative PedsQLTM data

Aim: To compare Health-Related Quality of Life (HRQOL) of paediatric patients with newly collected HRQOL data of the general Dutch population, explore responses to individual items and investigate variables associated with HRQOL. Methods: Children (8–12y) and adolescents (13–17y) from the general population (N = 966) and from a paediatric population (N = 1209) completed the Pediatric Quality of Life Inventory (PedsQLTM) online via the KLIK Patient-Reported Outcome Measures portal. PedsQLTM scale scores were compared between groups with independent t tests, by age group and gender. Responses to PedsQLTM items were explored using descriptive analyses. Linear regression analyses were performed to determine which variables were associated with HRQOL. Results: Paediatric patients reported worse HRQOL than the general population on all PedsQLTM scales (p ≤.001, d = 0.20–1.03), except social functioning, and a high proportion reported problems on PedsQLTM items, for example, ‘I have trouble sleeping’. Younger age, female gender and school absence were negatively associated with HRQOL (β = −0.37–0.10, p ≤.008). Conclusion: Paediatric patients reported lower HRQOL than the general population, and school absence, female gender and younger age were associated with lower HRQOL. The results underline the importance to structurally monitor paediatric patients’ HRQOL in clinical practice to detect problems and offer the right help on time