Parallax Innovations is pleased to preview another cutting-edge product – the CT Sabre.  The CT Sabre is a robotic arm that fits inside the bore of a micro-CT scanner and is controlled remotely through software, allowing you to perform procedures, such as the delivery of therapeutic agents, biopsies, blood sampling, etc.

You can operate the arm during fluoroscopy:
✔ Full control of needle position
✔ Live view of needle under robotic control
✔ Highly accurate needle positioning
✔ Control of animal position
✔ Full control of x-ray angle

Alternatively, you can plan an intervention from a reconstructed 3D volume:
✔ Plan trajectory of needle with full anatomical information
✔ Easy-to-use, interactive planner – point and click to define trajectory
✔ No need to re-position the animal between acquisition and intervention

Safe and effective interventions for:
  ✔ Cardiac perfusion
  ✔ Biopsy
  ✔ Tissue injection
  ✔ Cannulation
  ✔ Blood sampling

If you have any questions or comments about the CT Sabre, we would love to hear from you.  Also, continue to watch this blog for future CT Sabre updates.

Our efforts to integrate our GPU reconstruction engine into different CT scanner platforms continue:  see below a video showing the installation process for the Parallax Innovations GPU engine on an eXplore CT-120 console computer.  The total install time is about 2 minutes, not including the download of the software.  We recommend upgrading to NVidia driver version 295.49, since this driver provides the aforementioned Fermi architecture support such as on the GTX 680 and 690 GPU adapters.

And here's a video comparing CPU vs. GPU CT engines on the same machine:

As before, if you're interested in helping to test this release, don't hesitate to contact us.

A couple weeks ago, I introduced the Rapid Fluoroscopy application and hinted that it could be used for more than the typical fluoroscopy applications.  In this post, I'm going to elaborate on that.

Parallax Innovations has been working with Dr. Eugene Wong and Ph.D. candidate Michael Jensen at the University of Western Ontario, who have customized their eXplore CT120 to allow it to be used for image-guided radiation delivery.  In particular, they have added a motorized, computer controlled collimator (shown below) to the system that allows them to narrow the x-ray beam for targeting a specific region of the specimen.  The image to the right is of a 4x4 cm radiochromic film showing how they can achieve an elliptical radiation pattern.

The problem that we helped them solve was how to define a series of exposures at prescribed angles as part of a micro CT protocol.  They needed the ability to fire any number of exposures with any allowable x-ray settings from any gantry position.  And in addition, they needed to be able to control the size of the collimator aperture at any given gantry position.  Except for the control of custom collimator, the requirements seemed to me to be close to the functionality already provided by the Rapid Fluoroscopy application.  Parallax Innovations  assisted by implementing a new custom protocol to the application – the treatment protocol.

Treatment protocols allow the operator to specify any number of gantry angles and for each angle, specify a number of other properties.  As you can see in the property editor pictured below, one can prescribe the x-ray settings (voltage/current/duration), a table offset from the landmark position, the focal spot size, and how many exposures to fire.  There are also settings for the maximum allowable anode heat before the exposures at this particular position can begin (anode heat threshold), the amount of time between exposures (decay time), and an option to wait for a given amount of time before beginning the exposures at this particular position (pause).

Note: the 140 kV voltage setting is not available with standard x-ray generators.  120 kV is normally the maximum.

For the custom collimator, Michael had already written an application to control it.  I asked him to add a remote procedure call (RPC) interface that would allow the fluoroscopy software to make RPC calls passing the collimator motor positions defined in the treatment protocol.

A custom protocol using Rapid Fluoroscopy was implemented and integrated with collimator control in a timely and efficient manner.  It provided a flexible and simple solution which accelerated the readiness of such a platform for targetted radiation delivery.  Now, when the Rapid Fluoroscopy software is switched on, it is possible to build and run radiation treatment protocols.  Such a combination can also be used for cardiac imaging, with the collimator shielding the rest of the animal from unnecessary radiation exposures, which could potentially improve image quality by reducing scattered radiation.  For more information about Dr. Wong's research, visit the University of Western Ontario website.

Special thanks to Michael Jensen for all the testing he has done with the treatment protocols.

Historically, researchers using pre-clinical CT have focused on two types of resolution – spatial and contrast. However, with cardiac CT, one should also be concerned about temporal resolution. In the clinical world, many vendors have focused on rotation speed. This is fine for human heart rates, but is not practical for pre-clinical research. Instead, it is necessary to capture information from multiple cardiac cycles. With this approach, the exposure time largely influences the temporal resolution. Recently, we tested some custom software for theCT-120 that lowers the exposure time to 6.3 ms. To the best of our knowledge, this is the fastest temporal resolution of any pre-clinical CT (a system at Duke shows results with 10 ms temporal resolution). A single projection demonstrating acceptable spatial resolution and contrast is shown in the associated graphic.

For years now, the importance of preclinical imaging for drug discovery has been stressed. Pharmaceuticals and CROs are under pressure to streamline the discovery and development phases of drug development, and imaging is invaluable in this regard. In addition, imaging has become an important part of clinical trials; so, focusing on imaging during preclinical development allows for the best imaging biomarkers to be discovered and validated earlier, leading to cost savings when the clinical stage is reached.

There are other important roles for preclinical imaging, however. One of these is the development of new clinical techniques. Yesterday, I read an interesting article describing a potentially new technique for treating cardiac arrhythmia. Micro CT images acquired byMark Riccio and company at Cornell, using an eXplore CT-120 played an important role in this research (check out the supplementary information and a summary article at Science/AAAS for some images). This is just one exciting example of the usefulness of preclinical imaging in the development of clinical treatments.

Gizmodo has picked up on our friends at Cornell University, with Cornell's $500,000 Micro-CT Scanner Lets You See Small Things in Color 3D, which really demonstrates both the breadth of  capabilities of their eXplore CT-120 scanner, as well as how organized and tech-savy their group is.  It`s worth a perusal.