Bone marrow lesions are common, and imaging findings are associated with various aetiologies, as compared to conventional radiography and computed tomography (CT), MRI is a better non-invasive imaging modality to evaluate vertebral bone marrow, due to better soft-tissue contrast, so the aim of our study is the use of MRI diffusion in differentiating various vertebral bone marrow pathological lesions.

Bone marrow lesions are common, and imaging findings are associated with various aetiologies, such as degenerative, infectious, traumatic, malignant, metabolic, and haematopoietic .

As compared to conventional radiography and computed tomography (CT), MRI is a better non-invasive imaging modality to evaluate vertebral bone marrow, due to better soft-tissue contrast as well as being non-ionising in nature .

Although conventional MRI is essential for anatomical visualization and lesion detection in bone marrow pathologies ,but it often insufficient in distinguishing different vertebral bone marrow lesions, due to overlapping imaging features and often due to coexistence of bone marrow oedema that can be caused by fractures, infection, and bone marrow hyperplasia, thus reducing the specificity of conventional sequences .

MRI diffusion provides complementary information about tissue microstructure and cellular .it exploits the translational mobility of water molecules to obtain information on the microscopic behaviour of the tissues.

On the other hand, apparent diffusion coefficient (ADC) values provide quantitative measure of Brownian movement with low ADC values implying restricted diffusion and high values being a measure of free diffusion.

Therefore, DWI provides both qualitative and quantitative functional information concerning the microscopic movements of water at the cellular level. The benefits of DWI comprise a small scanning period that allows it to be easily included in the routine imaging protocols .

For example, In healthy bone marrow, water diffusion is relatively unrestricted due to its cellularity and vascularity, while pathologies such as metastatic disease or myelofibrosis typically exhibit restricted diffusion.

Diffusion MRI can also distinguish bone marrow edema like acute injury or inflammation, from infiltrative diseases such as multiple myeloma. Edema typically shows higher ADC values due to the increased water content, whereas infiltrative diseases reduce diffusion, resulting in lower ADC values.

These examples illustrate how MRI diffusion can differentiate various vertebral bone marrow pathological lesions.

Inclusion Criteria:

• All adult patients with vertebral lesions Clinically suspected or diagnosed by other modalities as X-ray or CT were included in the study.

Exclusion Criteria:

• Patients with metallic prosthesis which are not MRI compatible .
• patients with previous Vertebral surgery.
• patients with Vertebral Congenital anomalies
• Patients refused the examination.
• Patients who suffer from claustrophobia

- All adult patients with various vertebral bone marrow lesions.