How is slice thickness controlled in 3rd generation scanners?

In 3rd generation CT scanners, slice thickness is controlled through a combination of pre-patient collimation and the configuration of the detectors. This dual control is essential for achieving the desired image quality and resolution.

Pre-patient collimation involves the use of metal or lead plates that are placed before the x-ray beam reaches the patient. This collimation allows the technologist to define the width of the x-ray beam that will interact with the patient's body, effectively limiting the thickness of the slice that is acquired. By adjusting these collimators, the operator can narrow or widen the x-ray beam to produce thinner or thicker slices based on the imaging requirements.

In addition to pre-patient collimation, the configuration of the detectors plays a key role in slice thickness control. The arrangement, number, and size of the detectors directly affect how much of the x-ray beam is captured and subsequently processed. A system with multiple detectors can allow for more flexibility in selecting slice thickness, as it can either combine signals from multiple adjacent detectors for thicker slices or use individual detectors for thinner slices.

Combining these two methods enables more precise control over image acquisition parameters, allowing for optimization based on clinical needs, patient size, and the specific area of interest