# Effect of data-driven motion correction for respiratory movement on lesion detectability in PET-CT: a phantom study

## TL;DR

This study examines how data-driven motion correction affects lesion detection in PET-CT scans using a phantom model.

## Contribution

The study evaluates the impact of data-driven motion correction on lesion detectability under varying motion conditions.

## Key findings

- DDMC increases maximal and mean recovery coefficients in target spheres.
- Contrast-to-noise ratio improves for small, high-motion targets but decreases for larger spheres with smaller motion.
- DDMC increases background noise, which may reduce detectability for motion-unaffected targets.

## Abstract

While data-driven motion correction (DDMC) techniques have proven to enhance the visibility of lesions affected by motion, their impact on overall detectability remains unclear. This study investigates whether DDMC improves lesion detectability in PET-CT using FDG-18F.

A moving platform simulated respiratory motion in a NEMA-IEC body phantom with varying amplitudes (0, 7, 10, 20, 30 mm) and target-to-background ratios (2, 5, 10.5). Scans were reconstructed with and without DDMC, and the spherical targets’ maximal and mean recovery coefficient (RC) and contrast-to-noise ratio (CNR) were measured.

DDMC results in higher RC values in the target spheres. CNR values increase for small, high-motion affected targets but decrease for larger spheres with smaller amplitudes. A sub-analysis shows that DDMC increases the contrast of the sphere along with a 36% increase in background noise.

While DDMC significantly enhances contrast (RC), its impact on detectability (CNR) is less profound due to increased background noise. CNR improves for small targets with high motion amplitude, potentially enhancing the detectability of low-uptake lesions. Given that the increased background noise may reduce detectability for targets unaffected by motion, we suggest that DDMC reconstructions are used best in addition to non-DDMC reconstructions.

The online version contains supplementary material available at 10.1186/s40658-025-00784-x.