A new emphysema treatment uses endobronchial valves to perform lobar volume reduction. The degree of
fissure completeness may predict treatment efficacy. This study investigated the behavior of a semiautomated
algorithm for quantifying lung fissure integrity in CT with respect to reconstruction kernel and
dose. Raw CT data was obtained for six asymptomatic patients from a high-risk population for lung cancer.
The patients were scanned on either a Siemens Sensation 16 or 64, using a low-dose protocol of 120 kVp,
25 mAs. Images were reconstructed using kernels ranging from smooth to sharp (B10f, B30f, B50f, B70f).
Research software was used to simulate an even lower-dose acquisition of 15 mAs, and images were
generated at the same kernels resulting in 8 series per patient. The left major fissure was manually
contoured axially at regular intervals, yielding 37 contours across all patients. These contours were read
into an image analysis and pattern classification system which computed a Fissure Integrity Score (FIS) for
each kernel and dose. FIS values were analyzed using a mixed-effects model with kernel and dose as fixed
effects and patient as random effect to test for difference due to kernel and dose. Analysis revealed no
difference in FIS between the smooth kernels (B10f, B30f) nor between sharp kernels (B50f, B70f), but
there was a significant difference between the sharp and smooth groups (p = 0.020). There was no
significant difference in FIS between the two low-dose reconstructions (p = 0.882). Using a cutoff of 90%,
the number of incomplete fissures increased from 5 to 10 when the imaging protocol changed from B50f to
B30f. Reconstruction kernel has a significant effect on quantification of fissure integrity in CT. This has
potential implications when selecting patients for endobronchial valve therapy.