What does the term 'slice sensitivity profile (SSP)' refer to in CT imaging?

The term 'slice sensitivity profile (SSP)' in CT imaging specifically refers to the broadening of the section width in helical CT. This concept is crucial because it describes how the sensitivity of the imaging system varies across the slice thickness being acquired.

In helical (or spiral) CT, the x-ray tube rotates continuously while the patient moves through the gantry, resulting in overlapping data acquisition. This method allows for thinner slices to be reconstructed, but the actual slice sensitivity profile indicates how the acquired data represents the tissues within the broadening slice. A broader slice can encompass and contribute to more statistical noise but can also improve the signal-to-noise ratio.

Understanding the SSP is vital for optimizing image quality and ensuring accurate representation of anatomical structures in the resulting images. It aids radiologists and technologists in making informed decisions regarding slice thickness and settings based on the clinical requirements of different examinations.