AT pathology qualitative classification for DW and ADC images graded in accordance with physical performance and clinical examination scores applied, cell structure and MR signal appearance on routine images.

Table 4: AT pathology qualitative classification for DW and ADC images graded in accordance with physical performance and clinical examination scores applied, cell structure and MR signal appearance on routine images.

AT injury patient Performance Scoring	Pathology	Impact on cell structure and diffusivity	MR Image Appearance	Qualitative DW & ADC five-number summary scoring
Poor	Tears, Complete Rupture	Deformity with retraction, little/high swelling.	Hyper-intense signal subtotal and complete discontinuity of the Achilles tendon. Possible wavy tendon morphology and retraction.	High
Fair	Partial/Micro Tears	Up to 50% of the AT is damaged, swelling, positive for significant fibre disruption, probably including some retraction	Possible hyper-intense focal defect and partial retraction of tendon fibres	High-mid
Good	Thickening and Tendinopathy	A small number of ligament fibres are damaged. There is usually an area of increased oedematous swelling.	MRI negative (hypo-intense AT). MR signal intensity increase is seen only in association with cases of oedema	Medium
Great	Inflammation	No abnormalities or diffuse bleeding	MRI negative (hypo-intense AT), No structural damage	Mid-low
Excellent	Normal	Normal intact tendon	Normal hypo-intense signal	Low