Added Value of Qualitative and Quantitative Diffusion Weighted Magnetic Resonance Imaging (DWI-MRI) in Assessment of Non neoplastic Achilles tendon Related Pathologies.

Background: It has been demonstrated that magnetic resonance imaging (MRI) techniques of Diffusion Weighted Imaging (DWI) and Apparent Diffusion Coefficient (ADC) mapping can facilitate the identification of structural and biochemical alterations in tissue, offer early detection of pathological changes, and track tissue damage. Purpose of this study was to assess how useful DWI and ADC mapping are for identifying Achilles tendon (AT) disorders. Methods: This case-control study was done on 60 participants; 30 symptomatic patients with suspected AT pathology and 30 healthy volunteers as control group. Subjects underwent MRI of the ankle with multiple sequences (T1, T2, STIR, proton density), complemented by DWI and ADC images. Results: Final MRI diagnosis was tendinopathy, inflammation, partial tear, complete tear and Haglund syndrome. DWI demonstrated high sensitivity in detecting pathology of Achilles tendon with relatively lower specificity. ADC measurement had statistically significant higher value comparing the patients and healthy controls (p value <0.001.) with sensitivity (100%) and specificity (96.67%). Combining DWI& ADC with conventional MRI improved the diagnostic accuracy sensitivity (100%), a specificity (75%), accuracy (95%), PPV of (78 %) and NPV of (100%). Agreement between DWI/ADC and reference standard was good. Conclusion: Quantitative ADC mapping provides valuable complementary information to conventional MRI in diagnosing AT pathologies. While DWI offers good sensitivity and diagnostic accuracy, ADC analysis helps distinguish true diffusion restriction from T2 shine-through effects. In addition, diffusion MRI remains limited by lower spatial resolution and image quality compared with conventional MRI images. Keywords: DW MRI; ADC mapping; Conventional MRI; Achilles tendon.