CT image construction of the lung in a totally deflated mode

A novel technique is proposed to construct CT images of the lung in a totally deflated mode using non-rigid registration and extrapolation. This CT image would be very useful in performing tumor ablative procedures (such as brachytherapy) for the treatment of lung cancer. This is because during such procedures the target lung is almost completely deflated whereas pre-operative images are acquired while the lung is partially inflated. This makes pre-operative images very inaccurate. Given that Ultrasound (US) imaging is very sensitive to residual air in a deflated lung, it is not an effective intra-operative imaging modality by itself. One possible approach for image guided lung brachytherapy is registering low quality intra-operative ultrasound images to high quality lung CT image of the deflated lung constructed using the proposed technique. The technique was applied to an ex-vivo porcine lung and the preliminary results were found to be very encouraging.