Fig. 2

Typical profiles of diaphragm longitudinal strain quantification by sparkle tracking in eupnea and deep breathing. A: In eupnea, the maximum diaphragm longitudinal strain value of each segment of the region of interest. Furthermore, the curves represent the strain over time of each segment during diaphragmatic contraction (one respiration cycle). The white squares represent the maximum longitudinal strain values (white arrow). The strain values vary during the time due to diaphragmatic contraction induced by breathing. B: Maximal diaphragm longitudinal strain value of each segment of the region of interest in deep breathing. And, the curves are representing strain over time of each segment for diaphragmatic contraction. The white squares represent the maximum longitudinal strain values (white arrow). The strain values change over time as a result of diaphragmatic contraction caused by breathing. In this example, the maximal diaphragm longitudinal strain value in eupnea (A) and deep breathing(B) was -40% and -21%, respectively. The more negative value means the higher degree of deformation (contraction)