# Photon-counting CT-guided bone biopsy with real-time bone marrow edema mapping

## TL;DR

Photon-counting CT with real-time bone marrow edema mapping helps improve the accuracy and safety of bone biopsies for diagnosing bone lesions.

## Contribution

This study demonstrates the feasibility of using PCCT with real-time BME mapping for bone biopsy guidance.

## Key findings

- The diagnostic yield was 70% with 87.5% accuracy for cases with a definitive reference standard.
- Monoenergetic 70-keV imaging showed significant differences in HU values between lytic and sclerotic lesions.
- PCCT-guided biopsy improved lesion visualization, procedural efficiency, and operator confidence.

## Abstract

Computed tomography-guided biopsies are needed to diagnose bone lesions, but can sometimes be challenging. We evaluated the feasibility and usefulness of photon-counting computed tomography (PCCT)-guided bone biopsies, focusing on real-time bone marrow oedema (BME) mapping to optimise diagnostic yield.

This retrospective single-centre study included procedures performed from September 2024 to May 2025 using a first-generation dual-source PCCT scanner with Quantum HD mode. Ten consecutive patients underwent PCCT-guided bone biopsy with real-time BME reconstructions. The reference standard was established using histopathology or microbiological confirmation when available; clinical and ≥ 3-month radiologic follow-up for nondiagnostic or discordant results. Statistical analysis included descriptive statistics, independent unpaired t-tests, and correlation analysis (SPSS v22.0, RStudio).

Ten patients, five women and five men, aged 60.5 ± 13.5 years (mean ± standard deviation), were included in the final analysis. The overall diagnostic yield was 70% (7/10), with a diagnostic accuracy of 87.5% (7/8) for cases with a definitive reference standard. Final diagnoses comprised tumour bone metastases (n = 7, 70%), bone osteomyelitis (n = 1, 10%), and bone marrow deposition disease (n = 2, 20%). Mean radiation dose (dose-length product) was 644.5 ± 112.1 mGy·cm. Monoenergetic 70-keV imaging showed significant differences between mean HU values of lytic (42.6) and sclerotic lesions (476.2) (p = 0.009), with a strong negative correlation between lesion morphology (sclerotic versus lytic) and monoenergetic 70-keV attenuation values (r = -0.84; p = 0.002).

PCCT-guided bone biopsy with real-time BME mapping proved feasible and showed encouraging diagnostic performance in this small exploratory cohort. Larger validation studies are needed.

By combining monoenergetic images and BME mapping, PCCT-guided bone biopsy improves lesion visualisation, operator confidence, procedural efficiency, and overall safety for diagnostic tissue sampling and active disease targeting.

Accurate targeting of active disease within complex bone lesions during CT-guided biopsy remains challenging sometimes.PCCT-guided biopsy with real-time BME mapping can enhance lesion targeting and procedural efficiency.PCCT-guided biopsy may improve safety, diagnostic accuracy, and operator confidence.

Accurate targeting of active disease within complex bone lesions during CT-guided biopsy remains challenging sometimes.

PCCT-guided biopsy with real-time BME mapping can enhance lesion targeting and procedural efficiency.

PCCT-guided biopsy may improve safety, diagnostic accuracy, and operator confidence.