Spinoff is NASA's annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.
NASA works hard to search out surprising discoveries but it works equally hard to avoid unpleasant ones related to the safety of its astronauts. NASA has identified approximately 30 risks to humans in space, from increased radiation, to decompression sickness, to interpersonal conflict between crewmembers. All of these risks are being studied carefully, explained Craig Kundrot, division director for Space Life and Physical Sciences Research and Applications.
But even with this detailed roadmap of risks, there are still unknowns. “When we went from two-week shuttle missions to six-month space station missions, that was a twelvefold increase in duration. All of a sudden we started seeing these vision problems,” he recalled. “That caught us by surprise.” Although NASA is still working to fully understand the details of those vision changes, researchers believe they are related to changes in blood flow in microgravity, which is something that has been studied for many years.
Ron Midura of the Cleveland Clinic's Lerner Research Institute received funding through Ames Research Center to study the hypothesis that vascular remodeling precedes and impacts muscle and bone loss. Midura's project started with a ground-based model — studying the hind legs of rats kept elevated to mimic the decreased blood flow seen in microgravity. He was presented with an opportunity to incorporate tissue samples from mice that had flown on the final mission of the Space Shuttle Program that he could then compare with his ground-based samples. A crucial part of getting useful data was being able to count the number of blood vessels in the tissue sample and make careful measurements of the thickness and shapes of the vessels.
Interpreting the images can be difficult, as is measuring the vessels. “Any manual accounting, even by highly trained technicians, would have been subjective and led to unnecessary variability,” Midura noted.
Instead, Midura turned to computer analysis to find the stained blood vessels and, knowing the spatial size of the pixels in the images, calculate their number, size, thickness, and other attributes. To get the analysis Midura needed, he turned to a software program created by ImageIQ that was originally spun out from the Cleveland Clinic but has since been acquired by Philadelphia-based ERT.
ImageIQ's software library was developed to analyze 2D and 3D images for research but the specific type of analysis Midura was looking for required some innovation. According to Amit Vasanji, cofounder of ImageIQ and now chief technology officer of imaging at ERT, the company custom-developed an algorithm that segmented each image into five different regions and then used further analysis to detect two different stains within each region. It also created a filter that helped the computer better differentiate between the stained blood vessel and the surrounding tissue. The program is able to identify structures and edges in a way that might not even be visible to a human eye and it can make extremely accurate measurements across the whole image.
Midura's study showed that there are genetic changes in the lower-leg vasculature system during spaceflight and these precede the bone and muscle loss that have been observed, though the work is very much ongoing.
At ERT, Vasanji noted that the imaging software has also powered clinical studies of pulmonary embolisms. Likewise, the tool is being used in clinical trials for stents and aneurysms, as well as for identifying lesions in the bladder. Another potentially lifesaving application is to help study cancer and one day potentially help treat it. Using the filters and algorithms created for Midura, researchers can identify the three-dimensional shape of the tumor within an image series.
Currently, the standard is to do a 2D view in a CT scan. But if the tumor is an irregular shape, that 2D slice will miss a great deal of information — details that would be extremely useful, for example, to a surgeon looking to excise it. Even more importantly, the tumor volume may be growing or shrinking in a way that a 2D image slice does not capture. And knowing the full shape can also help with diagnosis. Tumors that are benign usually are round with smooth edges, while tumors that are metastatic have spindles and are irregularly shaped.
NASA is still working to understand the vision changes that occur in space and tools and studies like Midura's will help it find answers.