Long-term pulmonary outcome of children with congenital diaphragmatic hernia: functional lung MRI using matrix-pencil decomposition enables side-specific assessment of lung function.

OBJECTIVES: In patients with congenital diaphragmatic hernia (CDH) the exact functional outcome of the affected lung side is still unknown, mainly due to the lack of spatially resolved diagnostic tools. Functional matrix-pencil decomposition (MP-) lung MRI fills this gap as it measures side-specific ventilation and perfusion. We aimed to assess the overall and side-specific pulmonary long-term outcomes of patients with CDH using lung function tests and MP-MRI. METHODS: Thirteen school-aged children with CDH (seven with small and six with large defect-sized CDH, defined as > 50% of the chest wall circumference being devoid of diaphragm tissue) and thirteen healthy matched controls underwent spirometry, multiple-breath washout, and MP-MRI. The main outcomes were forced expiratory volume in 1 second (FEV1), lung clearance index (LCI2.5), ventilation defect percentage (VDP), and perfusion defect percentage (QDP). RESULTS: Patients with a large CDH showed significantly reduced overall lung function compared to healthy controls (mean difference [95%-CIadjusted]: FEV1 (z-score) -4.26 [-5.61, -2.92], FVC (z-score) -3.97 [-5.68, -2.26], LCI2.5 (TO) 1.12 [0.47, 1.76], VDP (%) 8.59 [3.58, 13.60], QDP (%) 17.22 [13.16, 21.27]) and to patients with a small CDH. Side-specific examination by MP-MRI revealed particularly reduced ipsilateral ventilation and perfusion in patients with a large CDH (mean difference to contralateral side [95%-CIadjusted]: VDP (%) 14.80 [10.50, 19.00], QDP (%) 23.50 [1.75, 45.20]). CONCLUSIONS: Data indicate impaired overall lung function with particular limitation of the ipsilateral side in patients with a large CDH. MP-MRI is a promising tool to provide valuable side-specific functional information in the follow-up of patients with CDH. CLINICAL RELEVANCE STATEMENT: In patients with congenital diaphragmatic hernia, easily applicable MP-MRI allows specific examination of the lung side affected by the hernia and provides valuable information on ventilation and perfusion with implications for clinical practice, making it a promising tool for routine follow-up. KEY POINTS: • Functional matrix pencil decomposition (MP) MRI data from a small sample indicate reduced ipsilateral pulmonary ventilation and perfusion in children with large congenital diaphragmatic hernia (CDH). • Easily applicable pencil decomposition MRI provides valuable side-specific diagnostic information on lung ventilation and perfusion. This is a clear advantage over conventional lung function tests, helping to comprehensively follow up patients with congenital diaphragmatic hernia and monitor therapy effects.

Simultaneous multiple breath washout and oxygen-enhanced magnetic resonance imaging in healthy adults.

Lung function testing and lung imaging are commonly used techniques to monitor respiratory diseases, such as cystic fibrosis (CF). The nitrogen (N2) multiple-breath washout technique (MBW) has been shown to detect ventilation inhomogeneity in CF, but the underlying pathophysiological processes that are altered are often unclear. Dynamic oxygen-enhanced magnetic resonance imaging (OE-MRI) could potentially be performed simultaneously with MBW because both techniques require breathing of 100% oxygen (O2) and may allow for visualisation of alterations underlying impaired MBW outcomes. However, simultaneous MBW and OE-MRI has never been assessed, potentially as it requires a magnetic resonance (MR) compatible MBW equipment. In this pilot study, we assessed whether MBW and OE-MRI can be performed simultaneously using a commercial MBW device that has been modified to be MR-compatible. We performed simultaneous measurements in five healthy volunteers aged 25-35 years. We obtained O2 and N2 concentrations from both techniques, and generated O2 wash-in time constant and N2 washout maps from OE-MRI data. We obtained good quality simultaneous measurements in two healthy volunteers due to technical challenges related to the MBW equipment and poor tolerance. Oxygen and N2 concentrations from both techniques, as well as O2 wash-in time constant maps and N2 washout maps could be obtained, suggesting that simultaneous measurements may have the potential to allow for comparison and visualization of regional differences in ventilation underlying impaired MBW outcomes. Simultaneous MBW and OE-MRI measurements can be performed with a modified MBW device and may help to understand MBW outcomes, but the measurements are challenging and have poor feasibility.

Effects of elexacaftor/tezacaftor/ivacaftor therapy in children with cystic fibrosis - a comprehensive assessment using lung clearance index, spirometry, and functional and structural lung MRI.

BACKGROUND: With improvement in supportive therapies and the introduction of cystic fibrosis transmembrane conductance regulator (CFTR)-modulator treatment in patients with cystic fibrosis (CF), milder disease courses are expected. Therefore, sensitive parameters are needed to monitor disease course and effects of CFTR-modulators. Functional lung MRI using matrix-pencil decomposition (MP-MRI) is a promising tool for assessing ventilation and perfusion quantitatively. This study aimed to assess the treatment effect of elexacaftor/tezacaftor/ivacaftor combination regimen (ELX/TEZ/IVA) on measures of structural and functional lung abnormalities. METHODS: 24 children with CF underwent lung function tests (multiple breath washout, spirometry), functional and structural MRI twice (one year apart) before and once after at least two weeks (mean 4.7 ± 2.6 months) on ELX/TEZ/IVA. Main outcomes were changes (Δ) upon ELX/TEZ/IVA in lung function, defect percentage of ventilation (VDP) and perfusion (QDP), defect distribution index of ventilation and perfusion (DDIV, DDIQ), and Eichinger score. Statistical analyses were performed using paired t-tests and multilevel regression models with bootstrapping. RESULTS: We observed a significant improvement in lung function, structural and functional MRI parameters upon ELX/TEZ/IVA treatment (mean; 95%-CI): ΔLCI2.5 (TO) -0.84 (-1.62 to -0.06); ΔFEV1 (z-score) 1.05 (0.56 to 1.55); ΔVDP (% of impairment) -6.00 (-8.44 to -3.55); ΔQDP (% of impairment) -3.90 (-5.90 to -1.90); ΔDDIV -1.38 (-2.22 to -0.53); ΔDDIQ -0.31 (-0.73 to 0.12); ΔEichinger score -3.89 (-5.05 to -2.72). CONCLUSIONS: Besides lung function tests, functional and structural MRI is a suitable tool to monitor treatment response of ELX/TEZ/IVA therapy, and seems promising as outcome marker in the future.

Doppelganger-based training: Imitating our virtual self to accelerate interpersonal skills learning.

Interpersonal skills require mastering a wide range of competencies such as communication and adaptation to different situations. Effective training includes the use of videos in which role models perform the desired behaviours such that trainees can learn through behavioural mimicry. However, new technologies allow new ways of designing training. In the present study, given that virtual reality is emerging as a valuable training setting, we compare two different demonstration conditions within virtual reality by investigating the extent to which the use of doppelgangers as role models can boost trainees' interpersonal skills development as compared to a role model that does not resemble the trainees. We also assess trainees' level of self-efficacy and gender as potential moderators in this relationship. Participants delivered a speech in front of a virtual audience twice. Before delivering their second speech, they watched a role model giving a speech in front of the same audience. The role model was either their doppelganger or an avatar of the same gender depending on the condition they were randomly assigned to. Results showed that the doppelganger-based training was the most beneficial for male trainees low in self-efficacy. These findings have important implications for training design, suggesting that doppelganger-based training might be effective only for a specific subset of trainees.