To celebrate this year’s Halloween, Dr. Andrew Mathers (Global Product Manager in X-ray & CT) scanned a Tawny owl (Strix aluco) prepared and mounted by the process of taxidermy (c. 1999). X-ray CT enabled us to non-destructively visualise the internal structure of the stuffed owl in 3D, with exceptionally high detail.
From the 2D cross section, 3D rendered image and video, we can clearly see that this specimen was prepared according to traditional skin-mount taxidermy methods. The skin and feathers were retained, as were the original skull, leg bones and scapulae. The skeletal components were combined with wood wool and galvanised wire to form a mannequin that sits atop a wooden perch. Modelling clay was used to mount the glass hollow-hemispherical eyes, tail feathers and scapulae, and to reform many anatomical features, including cheekbones, coccyx and breast.
This X-ray CT scan was acquired at 80µm voxel resolution and 240 Watts, using a Nikon C2 Large Envelope System (LES). The system houses three X-ray sources (a Nikon 450kV microfocus with rotating target, a Varian 450kV minifocus, and a Nikon 225kV microfocus with interchangeable rotating and reflection targets), and two detectors (a flat panel and a Nikon curved linear diode array). For this scan, the Nikon 225kV microfocus source with Rotating.Target 2.0 and Varex 4343N flat panel detector configuration was used. Due to the high aspect ratio of the owl’s body (360mm tall and 130mm diameter) the scan was acquired using X.Tend (Nikon’s advanced approach to Helical CT). This scanning modality not only enabled the entire owl to be captured in a single acquisition, but also at substantially greater voxel resolution than achievable with conventional circular CT (80 vs. 120µm). For this scan, the detector acquired 7,471 projections (individual radiographs) at an exposure time of 1000ms and a gain of 6dB.
Using Nikon’s advanced Helical CT reconstruction algorithm, X-ray CT data was reconstructed in Nikon CT Pro 3D, which provides industry-leading speed without compromising quality. The resulting 3D data was rendered using the isosurface renderer in VGSTUDIO MAX 2022.1.