Background: BMLs are a common finding after acute bone trauma. BMLs are assessed with conventional MRI sequences. Unlike conventional MR imaging sequences, diffusion-weighted imaging depends on the random movement of water molecules. Intact bone marrow shows directional diffusion, whereas BML shows facilitated diffusion. ADC maps might add value to conventional MRI sequences in trauma imaging protocols.

Objective: To compare ADC map with conventional fat saturation imaging sequences in the detection of bone marrow lesions BMLs after knee trauma.

Methods: This study was carried out at Radio diagnosis Department, Zagazig University Hospitals; the present study was carried on 20 patients after suffering from knee trauma. Patients underwent Conventional and diffusion MRI, the lesions were calculated in ADC maps, STIR and FS PD weighted imaging.
Results: The BMLs have been calculated in terms of the number and volume in ADC map, PD FS weighted TSE imaging and STIR. The median volumes were calculated to test the level of significance. The total median value of all knee bones collectively in ADC map was (53.4 cm3) approximately twice the median lesion volume in STIR (20.7 cm3) and FS PD weighted images (24.7 cm3). The median values of the BML in ADC map of knee were statistically higher than the median value of BML in SITR and FS PD weighted TSE imaging sequences. All p-values were statistically significant.
Conclusion: Our results indicated that ADC maps are more sensitive than conventional MRI sequences as it improves the detection of small bone marrow lesions