Fig. 4From: The role of heterogeneity in asthma: a structure-to-function perspective(reproduced with permission from [28])Hyperpolarized helium-3 MRI axial slice of a mild asthmatic (left panel), a moderate asthmatic (middle panel), and a severe asthmatic (right panel). As depicted by the arrows, increasing severity of disease is associated with increasing ventilation defects and ventilation heterogeneityBack to article page