- José H. Leal
CT Scans of Shells and Mollusks
A recent activity we have been pursuing at the Museum is the acquisition and processing of computerized tomography scans (CT scans) of shells from our collection. CT scans combine a series of X-ray images, using dedicated computer software, to create three-dimensional and cross-sectional images (slices) of objects. CT scans have been used in medicine and industry for decades, but were only recently adopted in the study of invertebrates. The impromptu project has been developed in association with engineer John Korbin from the Sandia National Laboratories in Albuquerque, New Mexico. John creates the original scans, which are then processed by yours truly at the Museum using Dragonfly, a dedicated CT scan-processing software. (The learning curve is a bit steep, but progress has been made!)
CT scans are powerful tools in the study of molluscan anatomy and morphology in general, but can also be instrumental in studies of shell growth and modification during the life of a mollusk, such as reabsorption and thinning of the shell. The screen shot shows four views of the shell of a Dusky Cone, Conasprella stearnsii, the top-left image is a 3-D, “transparent” view, the others are cross-sections orthogonal (“perpendicular”) to each other. The CT scan of that not-quite--an-inch-long shell includes exactly 2,000 X-ray images! More on this topic soon! (Shell collected by Ken Piech).