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

OBJECTIVE: 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. MATERIALS AND METHODS: 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). RESULTS: 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. CONCLUSION: 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. RELEVANCE STATEMENT: 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. KEY POINTS: 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.