Quantitative Lung Function Assessment in 2-year old children after Congenital Diaphragmatic Hernia using Fourier Decomposition Magnetic Resonance Imaging

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Congenital diaphragmatic hernia (CDH) leads to herniation of abdominal organs into the thoracic cavity and consequently to impaired lung development, followed by lung hypoplasia. Lung hypoplasia and pulmonary hypertension are known to be the main determinants of survival outcome in cases of CDH if no severe additional malformations or syndromes are present. Lung hypoplasia is not only attributed to malformed airway structures but also to a dysfunctional micro vascular system. In healthy children the amount of alveoli increases until the age of about three and afterwards lung growth is based on the enlargement of preexistent alveoli. Therefore, postnatal development of lung tissue during childhood may be possible for children after CDH repair. Up to now, little is known to which extent the affected lung catches up.Current methods for perfusion weighted lung magnetic resonance imaging (MRI) are either based on dynamic contrast enhanced (DCE) MRI or arterial spin labeling (ASL) techniques. Although DCE-MRI offers much higher signal to noise ratio (SNR) than ASL techniques, the additional efforts in administering the contrast agent and its potential side-effects are disadvantages, especially in subjects with kidney disease (i.e. NSF). Recently, also a major debate has arisen which long-term side-effects may be associated to accumulation of gadolinium based contrast-agents in the brain. Therefore, especially in children the repetitive usage of contrast agent (e.g. for children with CDH enrolled into a follow-up program) should be evaluated critically and individually.With MRI lung perfusion and lung ventilation can be measured via the FD technique without the need for ionizing radiation. Our study group has demonstrated previously that DCE-measurements in 2-year old children after CDH are possible and detect side differences in lung perfusion values. Besides, in adult patients radiation free and contrast agent free quantification of perfusion and ventilation and thereby, V/Q imaging has been proven to be feasible by FD-techniques. Therefore, MRI is a suitable tool for follow-up of children after CDH, as being capable to visualize both lung morphology and lung function. The objectives of this research proposal is to implement the Fourier Decomposition technique for lung imaging in 2-year old children and to investigate the clinical value of the ventilation and perfusion maps for children with congenital diaphragmatic hernia. This comprises implementing 2D and 3D imaging techniques and post processing at 1.5T and its translation to 3T as well as correlation of the perfusion maps to DCE-MRI. Clinically, diagnostic value of the developed techniques, its power to detect changes in perfusion/ ventilation between contra- and ipsilateral lung and eventually describe implication of combined quantitative perfusion and ventilation imaging in CDH children on patient treatment and respectively follow-up procedure.