In SCDT, what causes slice thickness blooming to increase?

Slice thickness blooming refers to the phenomenon where the displayed images of a structure appear larger than they truly are, often due to the way data is collected and reconstructed in CT imaging. The correct answer indicates that increased pitch contributes to a decrease in slice thickness blooming.

When pitch is increased in CT imaging, the scanner moves the x-ray tube and detectors further apart relative to the table movement per rotation. This adjustment leads to less overlap in the volume of tissues scanned, resulting in thinner reconstructed slices. As the slices become thinner, the likelihood of blooming—where areas of higher attenuation or density expand beyond their actual anatomic boundaries—decreases. Essentially, the system captures more precise data about smaller volumes of the object being imaged, minimizing the distortion typically associated with blooming.

In contrast, decreased pitch results in tighter spacing between the slices, which can lead to more pronounced blooming effects due to the increased amount of overlap. Similarly, while increased tube current allows for better image quality through improved signal, it does not directly address the mechanics of slice thickness or blooming. Decreased collimation, which narrows the x-ray beam, might also contribute to increased blooming by capturing more tissue in each slice, further reinforcing why increased pitch is the correct factor for reducing the blooming