Figure 1.

Experimental setup. (a) Schematic setup of the human chest phantom. The fresh pig lung is placed in the inner cavity above the artificial diaphragm and attached with the trachea to a tube for external access. One pump ($P_1$) is used to maintain a negative pressure between inner cavity and lung resulting in the inflation of the lung. A second pump ($P_2$) can be used to move the diaphragm, for which different breathing pattern can be programmed. Different outer covers exist that for instance allow to fill the outer cavity with water to mimic the x-ray absorption of the chest. Here we used a single cover with sealed injection ports that allowed injection of artificial tumor nodules in the lung. (b) Shows the phantom mounted up-right on top of the rotary unit in front of the beam outlet and the ionization chamber. The photon counting detector was mounted 10.7 m upstream to provide sufficient sample-to-detector distance to successfully exploit PBI.