Quantitative analysis of regional airways obstruction using dynamic hyperpolarized ³He MRI—Preliminary results in children with cystic fibrosis

Abstract

Purpose: To investigate regional airways obstruction in patients with cystic fibrosis (CF) with quantitative analysis of dynamic hyperpolarized (HP) 3 He MRI. Materials and Methods:Dynamic radial projection MRI of HP 3 He gas was used to study respiratory dynamics in a group of eight children with CF. Signal kinetics in a total of seven regions of interest (ROIs; three in each lung, and one in the trachea) were compared with the results of spirometric pulmonary function tests (PFTs). The tracheal signal intensity was used as a form of "input function" to normalize for input flow effects.Results: A pattern of low flow rate in the upper lobes was observed. When the flow measurements from the peripheral ROIs were averaged to obtain an index of flow in the peripheral lung, a good correlation was found (P ϭ 3.74 ϫ 10 -5 ) with the forced expired volume in one second (FEV1). Conclusion:These results suggest that a quantitative measurement of localized airways obstruction in the early stages of CF may be obtained from dynamic 3 He MRI by using the slope of the signal rise as a measure of air flow into the peripheral lung. This study also demonstrates that children can cooperate well with the 3 He MRI technique.

Relationship between structural changes and hyperpolarized gas magnetic resonance imaging in chronic obstructive pulmonary disease using computational simulations with realistic alveolar geometry

“…In a small group of eight children with cystic fibrosis, comparison of He-3 imaging with functional measures of airway obstruction showed good correlation and also that children are able to tolerate helium imaging (Koumellis et al 2005). He-3 MRI has also been used to assess regional patterns of airway closure in asthma (Altes et al 2001;de Lange et al 2006).…”

Functional lung imaging using hyperpolarized gas MRI

“…3) (68) and CF (80). Semiquantitative approaches using the regional slope of gas uptake normalized to the uptake in the trachea have also been applied to CF (81). At present, dynamic techniques are 2D and are performed with a second inhalation of HP gas in which the first inhalation is used for static ventilation imaging as described above.…”

“…These preliminary studies showed regional patterns of obstruction that correlated with FEV 1 . The goal of this regional approach is early detection and evaluation of small airway disease for more sensitive and specific detection of disease progression and response to therapy (81).…”

Assessment of hyperpolarized 3He lung MRI for regional evaluation of interventional therapy: A pilot study in pediatric cystic fibrosis

“…3-Helium ( 3 He) MRI of the lungs is a powerful tool for assessing gas distribution and lung function, and ventilation defects in adults and children with CF have been previously reported (14)(15)(16)(17)(18).…”