25 Nov, 2013 By rudi 0 Comments
Medical CT scanners are optimized for clinical diagnosis of patients and short acquisition times. µCT scanners, in contrast, are optimized to achieve very high resolutions using varying tube parameters, regardless of the scanning time. This high resolution is the precondition for the extraordinary quality of our documentations. We are using one of a few machines available in Europe that offers spiral scanning mode to capture the whole body of a violin in one pass which can take up to 12 hours. As a result we can offer an abundance of detail and a depth of information unobtainable by any other scanning technology.
Here is an example of a usual data set generated by a medical CT scanner: structures are visible but the picture is coarse and appears blurred.
The same structures are scanned here with our µCT technology. The sharp image allows visualizing the glue joints and even their thickness and the structure of the wood is easy to capture.
Any minimal movement of the instrument during the scan would result in a “motion artefact” (blurring). Therefore it has to be meticulously mounted on a stable fixture. We developed several stands that guarantee absolute protection of the precious instruments. Optionally, one or two violins can be scanned at once.
Viscom X8060 II at the Vienna MicroCT Lab
The scanning technology is entirely non-invasive. During the procedure, instruments are not exposed to any mechanical stress. The climate in the scan chamber is kept within conditions that instruments would also face under normal conditions (temperature max. 28-30° C, relative humidity 38-50%).
The raw data consists of a stack of more than 6,000 single X-ray images, generated by the tomographical spiral scan. A specialized reconstruction software allows us to compute different two- or three-dimensional visualizations.
To enhance the contrast of the different materials, the grayscale of the X-ray images can be converted to false-color images. Regions of high density (particularly organic glue) appear in bright colors, low density regions appear dark (e.g. the soft cells of the annual rings).