Diffusion-Weighted Imaging Distinguishes Between Osteomyelitis, Bone Marrow Edema, and Healthy Bone on Forefoot Magnetic Resonance Imaging
Journal Paper/Review - Feb 1, 2022
Kruk Konrad, Dietrich Tobias, Wildermuth Simon, Leschka Sebastian, Toepfer Andreas, Wälti Stephan, Kim Chan-Hi Olaf, Güsewell Sabine, Fischer Tim
Diagnosis of osteomyelitis by imaging can be challenging. The feasibility of diffusion-weighted imaging (DWI) as ancillary sequence was evaluated in this study.
To evaluate DWI for differentiation between osteomyelitis, bone marrow edema, and healthy bone on forefoot magnetic resonance imaging (MRI).
A total of 60 consecutive patients undergoing forefoot MRI divided into three study groups (20 subjects each): osteomyelitis, bone marrow edema, and healthy bone.
A 1.5T and 3T MRI scanners; readout-segmented multishot echo planar DWI.
Two independent radiologists measured apparent diffusion coefficient (ADC) values within abnormal or healthy bone.
ADC values were compared between groups (pairwise t-test with Bonferroni-Holm correction for multiple testing). Intraclass correlation coefficient (ICC) was calculated to assess inter-reader agreement. Threshold ADC values were determined as the cutoffs that maximized the sum of sensitivity and specificity. Receiver operating characteristic (ROC) analysis was performed with statistical threshold of P < 0.05.
Inter-reader agreement was 0.92 in the healthy bone group and 0.78 in both the edema and osteomyelitis groups. Average ADC values were significantly different between groups: 1432 ± 222 × 10 mm /sec (osteomyelitis), 1071 ± 196 × 10 mm /sec (bone marrow edema), and 277 ± 89 × 10 mm /sec (healthy bone). A threshold ADC value of 534 × 10 mm /sec distinguishes between healthy and abnormal bone with specificity and sensitivity of 100% each. For distinction between osteomyelitis and bone marrow edema, two cutoff values were determined: a 95%-specificity cutoff indicating osteomyelitis (>1320 × 10 mm /sec) and a 95%-sensitivity cutoff indicating bone marrow edema (<1155 × 10 mm /sec). Diagnostic accuracy of 95% was achieved for 73% (29/40) of the subjects.
DWI with ADC maps distinguishes between healthy and abnormal bone on forefoot MRI. Calculated cutoff values allow confirmation or exclusion of osteomyelitis in a high proportion of subjects.
2 TECHNICAL EFFICACY: Stage 2.