Hepatic CT perfusion measurements: a feasibility study for radiation dose reduction using new image reconstruction...

Area of Science:

• Radiology
• Medical Imaging
• Hepatic Perfusion Imaging

Background:

• Hepatic CT perfusion (CTP) imaging is crucial for assessing liver function.
• Optimizing radiation dose while maintaining diagnostic image quality is a significant challenge.
• Image reconstruction techniques play a vital role in noise reduction and image quality enhancement.

Purpose of the Study:

• To evaluate the impact of different image reconstruction methods on hepatic CT perfusion (CTP) values.
• To assess the effect of varying radiation doses on CTP measurements.
• To determine if adaptive iterative dose reduction (AIDR) can reduce noise without compromising perfusion accuracy.

Main Methods:

• Sixty patients underwent hepatic CTP using standard or low radiation dose protocols.
• CT images were reconstructed using filtered back projection (FBP), quantum de-noising (QDS), and adaptive iterative dose reduction (AIDR).
• Hepatic arterial perfusion (HAP), portal perfusion (HPP), and arterial perfusion fraction (APF) were calculated using the dual-input maximum slope method.

Main Results:

• No significant differences were observed in demographic features, mean perfusion values (HAP, HPP, APF), or Hounsfield unit (HU) values between groups or reconstruction methods.
• Mean image noise (standard deviation of HU) was significantly lower in the standard dose group compared to the low dose group.
• AIDR significantly reduced image noise compared to FBP in both standard and low dose groups, with approximately 45% radiation dose reduction achieved.

Conclusions:

• Image reconstruction methods, including AIDR, do not influence hepatic perfusion values calculated by the dual-input maximum slope method.
• Adaptive iterative dose reduction (AIDR) effectively reduces image noise in hepatic CTP, enabling potential radiation dose reduction.
• The findings support the use of AIDR for improving image quality in low-dose hepatic CTP.