Regional assessment of lung function using thin-plate splines to align structural and functional imaging

Ventilation / perfusion (VQ) Single Photon Emission Computed Tomography (SPECT) imaging provides 3D data of the regional distribution of ventilation and perfusion throughout the lung, but interpretation of the results is difficult without reference to the underlying lung anatomy. Multi-Slice Computed Tomography (MSCT) imaging is able to provide significant anatomical detail in the lung, allowing delineation of regional features such as the lobes. The purpose of this work was to develop software tools to allow the alignment of regions delineated from the MSCT scans, with the corresponding SPECT data, to allow measurements of VQ to be made for anatomically meaningful regions. The technique developed was based on the use of thin-plate splines and the results showed that it was able to provide good alignment between the MSCT and SPECT data.