Whole-Body Diffusion-Weighted Imaging in Chronic Recurrent Multifocal Osteomyelitis in Children

Area of Science:

• Radiology
• Pediatric Imaging
• Inflammatory Diseases

Background:

• Chronic recurrent multifocal osteomyelitis (CRMO), also known as chronic non-bacterial osteomyelitis (CNO), is a rare auto-inflammatory condition.
• CRMO/CNO commonly presents with musculoskeletal pain, making differentiation from other pediatric musculoskeletal disorders and malignancies challenging.
• Evaluating the utility of whole-body diffusion-weighted imaging (WB-DWI) for characterizing CRMO lesions is crucial.

Purpose of the Study:

• To assess the visibility of CRMO lesions using WB-DWI.
• To determine the clinical value of WB-DWI in characterizing MR-visible lesions.
• To evaluate the apparent diffusion coefficient (ADC) values in CRMO lesions.

Main Methods:

• Whole-body MRI at 3T was performed on 16 pediatric patients with confirmed CRMO.
• Imaging protocols included 2D STIR and axial diffusion-weighted imaging (DWI).
• Lesion visibility in DWI and STIR was assessed, and ADC values were measured and compared to reference regions.

Main Results:

• 33 CRMO lesions were identified, predominantly in long bones, visible on both STIR and DWI.
• Mean ADC values in CRMO lesions (1283 mm²/s) were significantly higher than in reference regions (782 mm²/s).
• A relative signal increase (lesion to reference) of over 10% was observed in 82% of lesions, with a median increase of 69%.

Conclusions:

• WB-DWI is a reliable technique for imaging pediatric patients at 3T.
• Elevated ADC values are characteristic of CRMO lesions.
• WB-DWI, combined with clinical data, shows promise in distinguishing benign inflammatory processes like CRMO from certain malignancies.