Figure 2. Demonstration of contrast development in X-ray micro-radiography of ethanol-preserved mouse lungs as a function of resting time.

Three different samples scanned after 10, 20 and 40 minutes of relaxation, respectively, are shown. Short resting time makes the trachea and bronchial tree being visible (A), while longer resting time leads to discernment of the alveolar structures of lungs. In (B) a superposition of bronchial and alveolar structures are visible, in (C) the alveolar structures hinder the visibility of the trachea and bronchial tree. Acquisition parameters: Tube voltage 60 kV, current 120 μA, acquisition time 40 s.