The XV Lung Ventilation Analysis Software is a software-based image processing technology that analyzes cinefluorograph images in combination with a CT image to quantify ventilation of pulmonary tissue, thereby providing support to physicians in their assessment of patients with lung diseases.The XV Lung Ventilation Analysis Software measures the tissue motion of the lung, at all locations throughout the lung, and at all phases of the breath. It uses these motion measurements to calculate the 4-dimensional (4D) ventilation of lung tissues. Quantification and statistics are provided in the form of a Report.The key outputs are:• The tidal volume (i.e. total lung ventilation), presented as a single value;• Visualization of lung ventilation with color-defined specific ventilation ranges;• The heterogeneity of lung ventilation, presented as three values; and• Ventilation graph/ histogram of the classified lung voxel’s relative frequencies including ventilation defect percentage.