A simplified three-dimensional volume measurement technique in keloid scars: Validity and reliability

SummaryIntroductionEffective treatment of keloid scars is important because patients are often confronted with major cosmetic, psychological, and social consequences. Three-dimensional (3D) imaging has been reported for the evaluation of keloid treatment. These techniques were complex to use in clinical practice. In this study, the validity and reliability of a simplified 3D volume measurement technique are defined.MethodsThirty-three scars were simulated using deformable modeling compound. The volume of the compound is calculated using the weight and density of the modeling compound, and it is compared with the 3D volume measurement.ResultsThe mean simulated keloid volume was 2.884 cc. The correlation was very high (r = 0.999), but there was a significant mean difference of 0.252 cc (p < 0.001). This was corrected using a formula, actual volume = 1.072 × measured volume. This formula was validated using a new data set of 33 simulated scars. There was a nonsignificant mean difference of 0.010 cc (p = 0.731).ConclusionThis 3D measurement technique combined with the correcting formula is valid and reliable to be used in practice for the evaluation of keloid scar treatment.