The Yune Soft Tissue Index

The Yune soft tissue index is used to assess the amount of soft tissue at the tips of the distal phalanges. This can help in early detection of acral soft-tissue atrophy (for example, in patients with scleroderma).

You take the amount of soft tissue at the tip of the finger (A) and compare it to the width of the base of the distal phalanx (B). If A is larger than B/4, then the amount of soft tissue is normal. If A is less than B/5, then the amount of soft tissue is abnormal.

The case above in a patient with scleroderma seemed borderline by eye. Let's see if the Yune soft tissue can help.
A = 2.9 mm
B = 13.4 mm

2.9 [?] (13.4/4)
2.9 < 3.35
∴ Not normal

2.9 [?] (13.4/5)
2.9 > 2.68
∴ Not abnormal

∴ Borderline.

References

Freyschmidt J, Brossmann J, Wiens J, Sternberg A. The Hand - Distal Phalanges. In Freyschmidt's Köhler and Zimmer: Borderlands of normal and early pathologic findings in skeletal radiography. Fifth revised edition. Thieme (2003). P 81.