Tidal changes on CT and progression of ARDS

Cereda, Maurizio; Xin, Yi; Hamedani, Hooman; Bellani, Giacomo; Kadlecek, Stephen; Clapp, Justin; Guerra, Luca; Meeder, Natalie; Rajaei, Jennia; Tustison, Nicholas J; Gee, James C; Kavanagh, Brian P; Rizi, Rahim R

These data suggest that a novel analysis of CT images may identify lung tissue at risk of further damage in experimental injury and might potentially predict outcome in patients with ARDS. Superimposing EI and EE images across the whole lung 11 identified areas of unstable inflation that appear to represent lung at increased risk of local strain (possibly atelectrauma) when ventilator settings are injurious; such areas are foci for the propagation of lung injury. This three-dimensional approach covers the whole lung, and because it involves voxel-wise assessment, it provides very high resolution (eg, 1 mm 3 in humans). These features are in contrast to conventional plain radiography (two-dimensional) 3 and standard CT (three-dimensional), which Figure 5 PRM maps on nine patients with ARDS imaged within 7 days from injury. The three patients who died in ICU or within 28 days from onset are shown on top. Voxels in the high-risk (yellow), severely injured (red) and normal density (green) domains are plotted in the corresponding images. Individual amounts of severely injured (I) and high-risk (R) tissue are shown for each patient as percent of total parenchyma. ARDS, acute respiratory distress syndrome; ICU, intensive care unit; PRM, parametric response map. critical care are used to generate single inflation images and with focus restricted to large lung regions.