Standardisation in Ultrasonography: Principle and Diagnostic Significance

Abstract

Disadvantage of ultrasonography is its dependence on subjective assessment of displayed images. The way how to minimize both intraobserver and interobserver differences is creation of standard conditions for examination including a quantitative approach to evaluation of tissue reflectivity. The oldest mode of standardisation is standardised A- scan, used in ophthalmology. It enables differentiation of echoes, reflected from different ocular structures and is helpful in assessment of extraocular muscle thickness. Standardisation of B- scan depends on the type of diagnostic device and is based on quantification of image echogenicity. In our study reference values of grey-level histogram were established for some thyroid diseases using standard setting of imaging parameters. Results indicate that both standardised A- and B- scan should be helpful in differential diagnostics.

Keywords

• Standardised echography
• Ultrasonography
• A- scan
• B- scan
• Echogenicity