Fig. 3A–B.

A clinical example of the measurement method is shown. (A) Measurement of the smallest remaining intact posterior wall is 21.36 mm and (B) the contralateral equivalent uninjured wall measurement is 43.14 mm. This was confirmed by tracing an overlay. This calculation is performed for measures obtained at multiple levels to ensure the largest percentage of wall involvement is obtained. The calculation is completed as follows: percent wall involvement = {(43.14 − 21.36)/(43.14)} × 100 = 50.5%, indicating “unstable.” This CT example was used as part of the participant instructions and was not one of the 10 cases used in the study.