PET/CT-guided biopsy with respiratory motion correction.

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Interventional Radiology

Background:

• Positron emission tomography (PET)/CT imaging aids in localizing malignancies, but respiratory motion causes imprecise tumor localization and shape distortion.
• Combined PET/CT-guided biopsy can improve diagnostic yield, yet motion artifacts hinder accuracy.

Purpose of the Study:

• To develop and assess a workflow for PET/CT-guided needle biopsy that integrates PET image guidance into the CT suite.
• To account for respiratory motion during PET/CT-guided biopsies to improve accuracy.

Main Methods:

• Evaluated PET/CT respiratory motion correction using the registered and summed phases (RASP) method via computer simulations and physical phantom studies.
• Assessed biopsy localization accuracy by measuring the distance between target centers and simulated biopsy locations in an anthropomorphic phantom.

Main Results:

• The RASP method significantly reduced PET image noise (0.10 SUV vs. 0.34 SUV) and lesion size distortion caused by respiratory motion.
• RASP reduced lesion localization error to 3.08 mm compared to 3.64 mm for ungated PET images, a reduction of approximately 0.6 mm.
• Lesion activity estimation (SUV) remained accurate and constant with RASP, unlike ungated images with ±50% variations.

Conclusions:

• The RASP method effectively reduces noise, attenuation artifacts, and respiratory motion in PET images, leading to more accurate lesion localization.
• The PET/CT-guided biopsy workflow using RASP demonstrates improved PET image quality and maintained lesion localization accuracy.
• RASP offers a feasible solution for enhancing the accuracy of PET/CT-guided biopsies in the presence of respiratory motion.