The inside story

When visible light scanning is not successful we can turn to another part of the electromagnetic spectrum to produce our 3D models – we use an X-ray beam. Unlike light, X-rays can penetrate even thick opaque material. Some of the X-rays in the beam will be absorbed by the object and the amount of absorption varies with the thickness, density and materials of the object. By detecting the variations in the X-rays that have passed through an object we can build a picture of the internal features. This only gives us a 2D image but by taking lots of digital X-ray images from different directions it is possible to reconstruct a 3D X-ray image of an object. This is computed tomography, also known as CT scanning.

Radiologists Ruth and Emily check the alignment of the sperm whale jaw bone ready for CT scanning

Radiologists Ruth and Emily check the alignment of the sperm whale jaw bone ready for CT scanning

At the weekend we made an out-of-hours visit to Radiology at Pinderfields Hospital, West Yorkshire, with a range of weird and wonderful packages that certainly raised a few curious eyebrows as we traversed the hospital foyer. The largest of these was half of the lower jaw of a sperm whale. When the CT scan it made, the x-ray source and detector spin round the object as it slowly passes through the circular gantry.

From the CT data we can explore the internal structures of the jaw, recreating slices through the bone at any angle and reconstruct the  surface of the object in 3D.  This will only be a black and white 3D model until the texture photographs are applied to the surface.

Sonia and Andy of the Visualising Animal Hard Tissues team arrange baleen objects for CT scanning

Sonia and Andy of the Visualising Animal Hard Tissues team arrange baleen objects for CT scanning

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s