Clinical Assessment of Breast Volume

Can 3D Imaging Be the Gold Standard?

Renee C. Killaars, MD; Myriam L. G. Preuβ, MD; Nathalie J. P. de Vos, MD; Camille C. J. L. Y. van Berlo, MD; Marc B. I. Lobbes, MD, PhD; René R. W. J. van der Hulst, MD, PhD; Andrzej A. Piatkowski, MD, PhD

Disclosures

Plast Reconstr Surg Glob Open. 2020;8(11):e3236 

In This Article

Results

The study was conducted at our outpatient clinic between December 2016 and June 2017. A total of 34 women fulfilled the inclusion criteria and were asked to participate in the study. In total, 29 women agreed to participate in the study. Fifty-three breast volumes were assessed. Mean age (SD) of participants was 50[11] years. Mean (SD) body mass index was 25.5 kg/m2 (4.46). Plastic surgeons who performed the clinical assessment were specialized in breast surgery, with a mean experience of 7.5 years (range, 3–16 years).

3D Breast Volume Compared With MRI (Gold Standard in Literature)

The ICC between the two 3D breast measurements was 0.991 (95% confidence interval (CI): 0.984–0.995). The Bland–Altman plot comparing one observer's 3D measurement with the other's demonstrated a mean difference between the two observers of 1.73 and limits of agreement ranging from –56.9 to 60.3. (Figure 3A). The ICC between the two MRI measurements was 0.990 (95% CI: 0.982–0.994). The Bland–Altman plot comparing one observer's MRI measurement with the other's demonstrated a mean difference between the two observers of 38.4 and limits of agreement ranging from –84.5 to 161.3. (Figure 3B)

Figure 3.

Comparison of reliability 3D and MRI breast measurements. A, The Bland–Altman plot comparing the 3D measurements demonstrates a mean difference of 1.73 (limits of agreement ranging from –56.9 to 60.3) between the 2 observers. B, The Bland–Altman analysis comparing 2 MRI measurements demonstrates a mean difference of 38.4 (limits of agreement ranging from –84.5 to 161.3) between the 2 observers.

Mean (SD) breast volume measured by 3D imaging was 454.0 cm3 (157.9), ranging from 192 to 764 cm3. Mean (SD) breast volume measured by MRI was 686.6 (312.5) ranging from 215 cm3 to 1483 cm3. There was a significant difference between 3D measurement and MRI (P < 0.001). ICC between the 3D and MRI measurements was 0.810 (95% CI: 0.670–0.891). The Bland–Altman analysis yielded a mean difference of 229.7, with limits of agreement ranging from –158.0 to 617.4 (Figure 4A). A proportional difference of 0.70 (95% CI: 0.56–0.85) was seen, indicating that the volume difference between the measurement methods increases with higher breast volumes. The systematic difference between the two methods was –173.2 cm3 (95% CI: –262.5 to –83.9), indicating that breast volumes obtained by MRI were overall larger than obtained by 3D.

Figure 4.

Comparison of measured volume in 3D, MRI and surgeon's estimation. A, The Bland–Altman analysis between 3D and MRI demonstrates a mean difference of 229.7 (limits of agreement ranging from –158.0 to 617.4). B, The Bland–Altman analysis between 3D and plastic surgeon's estimation demonstrates a mean difference of –17.7 (limits of agreement ranging from –270.7 to 235.3).

3D breast measurements were however significantly correlated (R = 0.84, P < 0.001). The relationship between 3D measurements and MRI was demonstrated in Figure 5. A linear regression was demonstrated between MRI and 3D, indicating y (MRI) = 1.58 × (3D) – 40.

Figure 5.

A scatter plot of MRI and 3D measurements. A simple linear regression could be performed to predict MRI from 3D measurements (F = 122.6; P < 0.001; R2 = 0.71). Y (predicted MRI) = 1.58 × (3D) – 40.

3D Breast Volume Compared With Clinical Standard (Plastic Surgeon's Estimation)

Mean (SD) volume estimated by plastic surgeons was 471.7 cm3 (168.9) for 1 breast. The discrepancy between the volume estimated by plastic surgeons and measured by 3D was only 17.7 cm3 (95% CI: –53.3 to 17.9). ICC between plastic surgeon's estimation and 3D volume was 0.815 (95% CI: 0.68–0.893).

Paired samples t-test showed no significant difference between 3D measurement and plastic surgeons' estimation (P = 0.323). The Bland–Altman plot yielded a mean difference of –17.7, with limits of agreement ranging from –270.7 to 235.3 (Figure 4B).

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