There's a method to the madness...

We've all seen photographs of exotic peppers... the ones you've always wanted to taste or grow for yourself, but chances are you've never seen an x-ray or CT or MRI scan of one. What I strive to do is to bring out the the previously unsuspected beauty found in the seemingly ordinary pepper pod.

It may be an extreme closeup photograph of a seed attached to the wall of a pod, or a CT scan demonstrating the delicate vascular bundles within the walls of the pepper which once brought it water and nutrients.

Sometimes the technology that goes into creating the image is as interesting as the images themselves. For those of you who are unfamiliar with the methods I choose to use I include a brief explanation of each of the techniques I've used thus far. While I do not currently have images to show from every method (I've still got some surprises in the works) I describe four of them here.

 

Method Explanation

Photography I'm sure you are familiar with how a camera works... A lens focuses the light reflected from an object onto the film or digital sensor and am image is created. The more light that is reflected from the object's surface, the brighter it appears in the final image.

Radiography
(X-ray)
In radiography, a bean of radiation is passed through the object being examined and the rays that are not stopped by the object create the image on the film or digital detector. The more dense parts of the object stop more x-rays from passing through and so create a shadow.

A major difference between photography and radiography is that rather than seeing things as they appear to the eye (like a photograph) an x-ray shows the structure inside the object. If an object contains items that are more dense than the majority of the subject (like metal, or in our case, seeds) they show up more brightly on the final image.


Computed Tomography
(CT Scan)
A CT scan is based upon x-ray technology so it too shows the densities within the pod, revealing the inner, hidden structures.

The scan itself consists of taking a number of x-rays from many different angles and then, using a computer, plotting the various densities to determine the 3-dimensional placement of the internal structures. After the scan is completed, the accumulated data can be reformatted to create images of thin slices of the object being examined.

It's as if you took a pepper pod and sliced it into thin (1 millimeter or less) slices, starting at one end and going all the way to the other, and then taking an x-ray of each individual slice, often just a millimeter in thickness. By doing a computer reconstruction it's possible to slice that pepper at any angle you want, put it back together again, and start slicing all over again in a different direction.


 

Magnetic Resonance Imaging
(MRI Scan)

An MRI scan does not use radiation like the radiograph or CT scan. It uses an extremely high powered magnet. The magnetic field aligns all  the protons within the hydrogen atoms in the object (it works best with subjects that contain lots of water) and then sends a radio-wave pulse through the object. This scrambles the proton alignment.

The scanner then computes the time it takes for the magnet to realign the atoms again. Using this measurement it is possible to determine the chemical makeup of the subject.

Then, like in the CT scanner, all the information obtained can be used to recreate slices of the pepper in any direction . The difference between the results of the MRI and that of the CT scan is that the MRI can be used to look at the function of the subject, not just the structure. Using an entire plant, the MRI scan can look at plant metabolism and actually measure the amounts of nutrients being metabolized during growth and fruit maturation.

POSTERS
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