The typical exam of an object will require 8, 16, or 32 images from different perspectives. In terms of memory storage, this is only on the order of hundreds of megabytes at most. No large image database will be formed, as all planes viewed in the volumetric display are created in near-real time. Any plane image or scan set of images may be saved at the user’s discretion. Therefore a conventional laptop or desktop computer with the Windows OS is capable of handling the load of the software.
There are three main components that are necessary to use Digitome: an appropriate x-ray source, a digital image plate (detector), and the software. The source and plate are separate pieces of equipment that you may be able to purchase separately or already have. Because of the light load, Digitome is portable and efficient.
Images may be acquired in one of two ways: 1) images of a variety of formats may be imported and examined, but the user will need to provide the metadata for the context of each image in the set; 2) images are acquired with the Digitome software with the correct driver. There needs to be some means of taking multiple images of an object from different perspectives, be it a turntable for the object or a moveable source.
There are several types of exams that the Digitome software uses to accommodate for the situations of the apparatus or the complications of the imaged object. The source, detector, and object of interest are not collinear.
The most important part of any taking an accurate Digitome exam is to calibrate the software properly to whatever setup is available or desired.
Digitome uses radiography (as opposed to fluoroscopy) to take images of an object. It records a user-specified number of frames of exposure for a user-specified time unit per frame and sums each frame to create a final, compiled 2-Dimensional image from the detector. Together, these two parameters (frame count and frame rate/exposure time) adjust the flux of photons that the image plate receives and records. If the flux is too high, the plate will become saturated and lose information about the object of interest, but if the flux is too low the plate may not gather enough detail about the object because of lack of a statistically significant amount of recorded data.
An x-ray source will have adjustable energy and current. The current is directly proportional to the flux and the energy determines what materials in the object are penetrated. While the current is generally constant for an exposure time, the energy is actually a peak value that is representative of a range of x-ray energies that will pass through the object or be attenuated by it. Generally, high-energy photons are more likely to pass through materials of higher atomic number (such as silver or indium) and/or greater thickness.
Viewing parameters that may be adjusted when looking at a 2D radiograph or the volumetric display for an object include the Image Absorption Coefficient, Image Gamma, and histogram values that depend on the detector being used. Because every new configuration requires a re-calibration of the system, the software also allows users to make physical length measurements in the volumetric display that may be accurate to the order of a tenth of a millimeter!
The software has been applied by the U.S. Government for over 30 years, and recently in the corporation’s collaboration with Davidson College, it has been used to study welding flaws, the digestive rates of snakes, paintings with different metal-based paints or multiple layers of images, archaeological artifacts from the Queen Anne’s Revenge
(the ship of infamous Blackbeard the Pirate), and everyday objects of interest such as a Blackberry phone, a Pythagorus cup
, Alaska quarter
, and a weighted die. It has other foreseeable applications as well.