Computed tomography texture analysis (or CTTA) is a method to obtain new useful biomarkers that provide objective and quantitative assessment of tumour heterogeneity by analysing the differences and patterns within the pixel values of an image. CTs can be worked with as a matrix of numbers, corresponding to Hounsfield units. Algorithms that perform mathematical operations on these matrices can reveal patterns and characteristics. There are over twenty texture analysis parameters which are standardised in radiomics.
Parameters assessed may include
- grey-level frequency distribution: pixel intensity histograms
- mean intensity, threshold (percentage of pixels within a specified range)
- entropy (irregularity)
- standard deviation
- skewness (asymmetry)
- kurtosis (peakedness/flatness of pixel histogram)
Applications
Oncological applications
- lesion characterisation
- pretreatment tumour assessment
- response evaluation for tumours
Non-oncological applications
- assessment of hepatic fibrosis and pulmonary fibrosis