Detection of Perifocal Bone Marrow Edema in Patients with Osteoid Osteoma Using Three-material Decomposition with Dual-layer Spectral CT

Presentation Format: Oral presentation.

Purpose or Learning Objective: To assess whether bone marrow edema in patients with osteoid osteoma (OO) can be accurately diagnosed based on three-material decomposition with spectral dual-layer computed tomography (DLCT).

Methods or Background: Overall, 18 patients with OO (25.33 ± 12.44 years; 7 women) and 18 patients without OO (26.72 ± 9.65; 9 women) were examined with DLCT and magnetic resonance imaging (MRI). DLCT data were decomposed into hydroxyapatite, water-equivalent, and fat-equivalent volume fraction maps using an in-house-developed algorithm. Two radiologists, blinded to clinical data, assessed DLCT-based volume fraction maps and MR images, including fluid-sensitive sequences, separately for the presence of perifocal bone marrow edema, using a Likert scale (1 = no edema; 2 = likely no edema; 3 = likely edema; 4 = edema). Agreement between DLCT and MRI, as well as interreader agreement, were assessed with Cohen's κ. Accuracy, sensitivity, and specificity for the identification of bone marrow edema on DLCT were analyzed using MRI findings as the standard of reference.

Results or Findings: For the identification of bone marrow edema in patients with OO, DLCT showed a sensitivity of 0.94, a specificity of 1.00, and an accuracy of 0.97 for both radiologists. Interreader agreement for the assessment of bone marrow edema was high for MRI: weighted κ, 0.90 (95% confidence interval [CI]), 0.76–1.00) and DLCT: 0.74 (95% CI, 0.54–0.93). Agreement between DLCT and MRI was substantial to almost perfect: weighted κ, 0.81 (95% CI, 0.69–0.92).

Conclusion: DLCT with material-specific volume fraction maps offered an accurate detection and evaluation of bone marrow edema in patients with OO. This technique may spare patients additional examinations and facilitate the diagnosis of OOs as well as posttherapeutic recurrence.

Publication History

Article published online:
03 June 2021