To celebrate World Ice Cream Day 2021, Dr. Andrew Mathers (X-ray CT Project Manager) scanned a large tub (465 ml) of ice cream to get the scoop on its structure and some of the hidden treats found within.
World Ice Cream Day is celebrated annually on the third Sunday of July, but it’s origins date back to the USA in 1984, when President Ronald Regan signed into public law a resolution (No. 5219) proclaiming July as ‘National Ice Cream Month’ as well as introducing ‘National Ice Cream Day’ within it. This highly popular food holiday in the United States quickly gained traction across the world and is the perfect excuse to indulge in what Regan describes as “the perfect dessert!”
X-ray CT enables us to non-destructively visualise the fine structure of the ice cream as well as the porosity within it. We can also resolve other structural features including the distribution of the marshmallow and caramel swirls, and the school of chocolatey fish (rendered in 3D in individual colours).
This X-ray CT scan was acquired at 39 µm voxel resolution and 158 Watts power, using a Nikon XT H 225 ST 2x. For these scans Andrew took advantage of Nikon’s 225kV microfocus Rotating.Target 2.0 and the Varex XRD 4343CT flat panel detector, which combine to provide greater X-ray photon flux without compromising resolution, compared to a standard system. Due to need to keep the tub upright and avoid cone beam artefacts the scan was performed using X.Tend (Nikon’s advanced approach to helical CT). For this scan the detector acquired 3370 projections at an exposure of 89 ms and a gain of 12 dB, resulting in a total scan time of just 5 minutes, which was critical to ensuring the ice cream did not melt during acquisition.
X-ray CT data was reconstructed in Nikon CT Pro 3D, using Nikon’s advanced helical CT reconstruction algorithm, which provides industry leading speed without compromising quality. The resultant 3D data was segmented and rendered in Volume Graphics Studio Max 3.5.