Q. How does ClearRead CT | Vessel Suppress work?
A. Vessel suppression is a product of modern machine learning. Vessel suppression was built using hundreds of normal scans that spanned many different acquisition protocols, and many thousands of simulated nodules that captured the large variety of different morphologies, texture and attenuation characteristics of real nodules. Vessel suppression works by predicting the local lung air value except where there is nodule tissue. It can be thought of as the ultimate minimum intensity projection, only nodules are left unaltered. Riverain opted for the name “vessel suppression” as the predominant structure in normal lungs is vascular structure. However, vessel suppression also suppresses the bronchial tree and pulmonary fissures: essentially, all normal structures are suppressed.
Q. How does ClearRead CT | Detect work?
A. Detect is built on top of ClearRead CT | Vessel Suppress. Using the vessel suppressed CT series, candidate nodules are detected using nothing more than simple thresholding and morphological post-processing. Through vessel suppression, nodules can be robustly and consistently detected, segmented, and characterized. Not all regions detected through this process are, of course, nodules. False positives, such as residual vascular structure or bronchial wall, or other abnormalities such as scarring, can lead to false marks. Detect attempts to limit the number of false positives to as few as possible. In doing so, some nodules may be inadvertently removed and so the radiologist must remain diligent.
Q. Does ClearRead CT | Vessel Suppress remove nodules?
A. Vessel suppression is designed to operate for nodules that are roughly spherical (not linear or overly flat) and not too small (generally no smaller than 3mm). The vessel suppression algorithm was built using thousands of simulated nodules with a large variety of properties. The algorithm was tested against thousands of actual nodules and was found to perform exceptionally well – not a single nodule was removed. This includes our clinical study, which used data from the NLST study. Vessel suppression has been found, however, to contain false positives. So the clinician must reference the original scan to ensure that what is being revealed by vessel suppression is in fact a true nodule.
Q. Does ClearRead CT | Vessel Suppress work for non-solid nodules?
A. Yes. Vessel suppression is designed to work on solid and non-solid nodules, including those that are pure ground glass. What’s more, vessel suppression can remove superimposed vascular structure from ground glass nodules without removing solid components. This enables reliable characterization of mixed non-solid nodules.
Q. Does ClearRead CT work on low-dose scans?
A. Yes. ClearRead CT contains several modules meant to preprocess the data prior to analysis; this includes a model for removing acquisition noise.
Q. Does ClearRead CT work on contrast scans?
A. Yes. ClearRead CT was designed to work on scans with or without intravenous contrast.
Q. Will ClearRead CT Suite work with my CT manufacturer?
A. Just like our ClearRead chest xray technologies, ClearRead CT is manufacturer neutral and will work across all manufacturers.