# Artifacts Mimicking Hardware Loosening After Iterative Metal Artifact Reduction (iMAR) Processing in Spinal Surgery

## TL;DR

This case report shows how a metal artifact reduction technique in CT scans can create misleading images that look like hardware loosening in spinal surgery patients.

## Contribution

The paper highlights a novel observation that iMAR processing can generate artifacts mimicking hardware loosening.

## Key findings

- iMAR-processed CT images showed hypodense lucencies around spinal hardware not seen in non-processed images.
- These artifacts were initially mistaken for hardware loosening or infection but were later identified as processing artifacts.
- The case underscores the need for careful interpretation of iMAR-processed images alongside clinical context.

## Abstract

Metallic implants often produce artifacts in computed tomography (CT) imaging, complicating the interpretation of postoperative findings. This case report describes a 63-year-old male with a history of cervical and lumbar spine surgeries who presented with worsening radicular pain. The patient underwent cervical decompression laminectomy and posterior instrumented fusion. Postoperative CT, processed with an iterative metal artifact reduction (iMAR) algorithm, revealed unexpected hypodense lucencies surrounding pedicle screws and fixation hardware, initially suggestive of hardware loosening or infection. However, these lucencies were not seen in non-processed images, indicating their artifactual nature. This case highlights the potential for iMAR to generate misleading findings that may mimic clinical conditions, emphasizing the need for a careful approach when interpreting iMAR-processed images in conjunction with clinical context and pre-processed datasets to prevent unnecessary interventions.