9:15-9:30. A Clinical Evaluation of Segmented Attenuation Correction

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiochemistry

Background:

• Transmission scans are crucial for attenuation correction in PET imaging.
• Longer transmission scan times can be inconvenient for patients and increase scan duration.
• Segmented attenuation correction (SAC) offers a potential solution to reduce scan times without sacrificing image quality.

Purpose of the Study:

• To clinically evaluate a Segmented Attenuation Correction (SAC) algorithm on the GE Advance PET system.
• To assess the impact of reduced transmission scan durations on PET image quality using SAC.
• To compare the performance of SAC against traditional Measured Attenuation Correction (MAC).

Main Methods:

• FDG whole-body emission scans were acquired.
• Dynamic transmission (Tx) scans were acquired and re-binned to durations of 2, 3, 4, 5, and 6 minutes.
• Images were reconstructed using iterative reconstruction with either MAC or SAC, with I(Tx6MAC) serving as the reference standard.
• Quantitative analysis included Normalized Mean Square Error (NMSE), liver activity variance, and bias.
• A blinded observer evaluated subjective image quality.

Main Results:

• NMSE increased with decreased Tx duration for SAC images, but less rapidly than for MAC images.
• SAC images with 3-minute Tx scans showed comparable quality to 6-minute SAC scans, with no significant compromise in noise or artifacts.
• Observer preference favored SAC images, noting improved boundary delineation and reduced noise.
• Liver activity bias for SAC images was approximately -8% in large patients.

Conclusions:

• The clinical evaluation validated the use of SAC with significantly shortened transmission scan times.
• SAC enables high-quality PET imaging even with transmission scans as short as 3 minutes.
• SAC represents an effective method for reducing PET scan duration while maintaining diagnostic image quality.