An analysis of pose in 3D stereophotogrammetry of the breast

Classification and assessment techniques of breast ptosis: A systematic review

BACKGROUND

Breast ptosis is characterized by the inferolateral descent of the glandular area and nipple-areola complex. A high degree of ptosis may negatively impact a woman's attractiveness and self-confidence. There are various classifications and measurement techniques for breast ptosis used as references in the medical and garment industry. A practical and comprehensive classification will provide accurate standardized definitions of the degrees of ptosis to facilitate the development of corrective surgeries and well-fitting undergarments for women in need.

METHODS

A systematic review on the classification and assessment techniques to measure breast ptosis was carried out based on the Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias was assessed using the modified Newcastle-Ottawa scale for observational studies, whereas the Revised Cochrane risk-of-bias tool for randomized trials (RoB2) was used to evaluate randomized studies.

RESULTS

Of 2550 articles identified in the literature search, 16 observational and 2 randomized studies describing the classification and assessment techniques of breast ptosis were included in the review. A total of 2033 subjects were involved. Half of the total observational studies had a Newcastle-Ottawa scale score of 5 and above. In addition, all randomized trials recorded a low overall bias.

CONCLUSION

A total of 7 classifications and 4 measurement techniques for breast ptosis were identified. However, most studies did not demonstrate a clear derivation of sample size beside lacking robust statistical analysis. Hence, further studies that apply the latest technology to combine the strength of previous assessment techniques are needed to develop better classification system that is applicable to all affected women.

Correction of breast asymmetry by autologous fat grafting with the aid of 3D laser-scanning technology

BACKGROUND

Currently, the lack of clinically accurate measurement and evaluation methods for breast asymmetry has considerably limited the use of autologous fat grafting in the correction of breast asymmetry.

OBJECTIVE

This study calculated the volume difference in the bilateral breasts by three-dimensional (3D) laser scanning technology, established a bridge between digitalization and surgery to guide the correction of breast asymmetry by autologous fat grafting, and evaluated the surgical effect.

METHODS

In the experimental group (3D group), the measurement range was defined by standardized methods, the algorithm to calculate the volume difference in the bilateral breasts was determined by the established software instructions, and the volume of intraoperative autologous fat grafting was guided by personalized data. In the control group, the volume of intraoperative autologous fat grafting was determined based on the surgeon's visual assessment and surgical experience.

RESULTS

The volume difference in the bilateral breasts was less at 12 months after surgery (P < 0.05), the satisfaction of patients was higher (P < 0.05), and the reoperation rate was lower (P < 0.05). The incidence of postoperative complications was low in both groups (P > 0.05).

CONCLUSIONS

3D laser scanning technology can be used as a bridge between digitalization and surgery to significantly improve the surgical effect of autologous fat grafting in the correction of breast asymmetry, with high patient satisfaction and high clinical application value.

Measuring Differential Volume Using the Subtraction Tool for Three-Dimensional Breast Volumetry: A Proof of Concept Study

Background. Three-dimensional (3D) photography provides a promising means of breast volumetry. Sources of error using a single-captured surface to calculate breast volume include inaccurate designation of breast boundaries and prediction of the invisible chest wall generated by computer software. An alternative approach is to measure differential volume using subtraction of 2 captured surfaces. Objectives. To explore 3D breast volumetry using the subtraction of superimposed images to calculate differential volume. To assess optimal patient positioning for accurate volumetric assessment. Methods. Known volumes of breast enhancers simulated volumetric changes to the breast (n = 12). 3D photographs were taken (3dMDtorso) with the subject positioned upright at 90° and posteriorly inclined at 30°. Patient position, breathing, distance and camera calibration were standardised. Volumetric analysis was performed using 3dMDvultus software. Results. A statistically significant difference was found between actual volume and measured volumes with subjects positioned at 90° (P < .05). No statistical difference was found at 30° (P = .078), but subsequent Bland–Altman analysis showed evidence of proportional bias (P < .05). There was good correlation between measured and actual volumes in both positions (r = .77 and r = .85, respectively). Univariate analyses showed breast enhancer volumes of 195 mL and 295 mL to incur bias. The coefficient of variation was 5.76% for single observer analysis. Conclusion. Positioning the subject at a 30° posterior incline provides more accurate results from better exposure of the inferior breast. The subtraction tool is a novel method of measuring differential volume. Future studies should explore methodology for application into the clinical setting.

A Simple Standardized Three-Dimensional Anthropometry for the Periocular Region in a European Population

BACKGROUND

The three-dimensional surface imaging system is becoming more common in plastic surgeries. However, few studies have assessed three-dimensional periocular structures and surgical outcomes. This study aimed to propose a standardized three-dimensional anthropometric protocol for the periocular region, investigate its precision and accuracy, and determine the three-dimensional periocular anthropometric norms for young Caucasians.

METHODS

Thirty-nine healthy young Caucasians (78 eyes) were enrolled. Three-dimensional facial images were obtained with a VECTRA M3 stereophotogrammetry device. Thirty-eight measurements in periocular regions were obtained from these images. Every subject underwent facial surface capture twice to evaluate its precision. A paper ruler was applied to assess its accuracy.

RESULTS

Sixty-three percent of measurements in linear distances, curvatures, angles, and indices were found to reach a statistically significant difference between sexes (p ≤ 0.05, respectively). Across all measurements, the average mean absolute difference was 0.29 mm in linear dimensions, 0.56 mm in curvatures, 1.67 degrees in angles, and 0.02 in indices. In relative error of magnitude, 18 percent of the measurements were determined excellent, 51 percent very good, 31 percent good, and none moderate. The mean value of the paper-ruler scale was 10.01 ± 0.05 mm, the mean absolute difference value 0.02 mm, and the relative error of magnitude 0.17 percent.

CONCLUSIONS

This is the first study to propose a detailed and standardized three-dimensional anthropometric protocol for the periocular region and confirm its high precision and accuracy. The results provided novel metric data concerning young Caucasian periocular anthropometry and determined the variability between sexes.

Unilateral Tissue Expander/Implant Two-Stage Breast Reconstruction with the Assistance of Three-Dimensional Surface Imaging

BACKGROUND

In China, traditional preoperative planning of unilateral breast reconstruction mainly depends on anthropometric measurement and visual assessment. Thus, the lack of objective assessment of breast volume and shape would likely result in suboptimal reconstruction outcomes. Three-dimensional surface imaging (3D-SI), which could provide objective measurement data of the breast, may be a promising solution to this problem.

METHODS

A retrospective review of patients undergoing tissue expander (TE)/implant breast reconstruction without any mammoplasty surgery on the contralateral sides in our hospital from August 2013 to May 2018 was performed. All the patients underwent unilateral mastectomy with immediate or delayed insertion of TE, followed by an exchange of a silicone gel implant without contralateral procedures. 3D images were obtained at the time of preoperation, the routine expansion visit, and post-exchange of implant. The breast volume measured by 3D-SI served as a guide to conduct the surgery management, such as in deciding the total volume of expansion and guiding the final implant size selection. 3D-SI also provided objective data to evaluate the final outcomes of the reconstruction.

RESULTS

Fifty-one patients were included in this study, in which eighteen patients underwent immediate TE insertion and thirty-three patients underwent delayed TE insertion. The ptosis degree of contralateral breasts was assessed as follows: forty-four were normal, and seven showed mild ptosis. The average expansion degree was controlled at 161.6% ± 14.1% compared to the contralateral breasts. The volume of implants exchanged had a strong linear correlation with the 3D volume of the contralateral breasts at the end of expansion (P < 0.01). The mean time of follow-up was 9.1 ± 6.6 months. There was only one patient who experienced TE leakage with secondary infection and received TE exchange. For the immediate reconstruction group, the overall breast symmetry improved at the completion of implant exchange (P < 0.01), with an average asymmetry of 5.3% ± 4.0% compared with 10.6% ± 6.1% initially. For the delayed reconstruction group, the reconstructed side achieved good volume symmetry to the contralateral side (P > 0.05). There was no significant difference in breast basal width between bilateral breasts post-reconstruction (P > 0.05).

CONCLUSION

3D-SI serves as a valuable adjunct by providing accurate 3D volume of breasts within TE/implant breast reconstruction in Chinese patients without obvious breast ptosis, which could facilitate surgeons to achieve good reconstructive outcomes.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Effect of skin tone on the accuracy of hybrid and passive stereophotogrammetry

BACKGROUND

Three-dimensional (3D) surface images acquired from stereophotogrammetry are increasingly being used to plan or evaluate treatment by plastic surgeons. Stereophotogrammetry exists in active, passive, and hybrid forms. Active and hybrid stereophotogrammetry are believed to capture darker surfaces more accurately than passive stereophotogrammetry. The purpose of this study was to investigate whether skin tone has a clinically relevant effect on the accuracy of hybrid and passive stereophotogrammetry.

MATERIALS AND METHODS

Seven subjects with different skin tones were recruited. 3D-printed face and breast were spray-painted in six different colors, ranging from white to black. The skin tones and paint colors were objectified by measuring their melanin index. 3D photos of the subjects and 3D prints were acquired with hybrid and passive stereophotogrammetry. These 3D photos were matched with specialized software, and their geometric differences were calculated.

RESULTS

None of the 3D photos showed a clinically relevant mean inaccuracy. On the 3D prints, hybrid stereophotogrammetry resulted in a smaller standard deviation of the inaccuracies than passive stereophotogrammetry (0.20 ± 0.06 mm vs. 0.35 ± 0.07 mm, p < 0.001). Passive stereophotogrammetry yielded a correlation between the melanin index of the spray paint colors and the standard deviation of the inaccuracy (Pearson's R = 0.60, p = 0.04). On human subjects, no correlation or difference in standard deviation of the accuracy was found.

CONCLUSION

Skin tone does not influence the accuracy of hybrid and passive 3D stereophotogrammetry in a clinically relevant way.

Three-Dimensional Imaging of the Face: A Comparison Between Three Different Imaging Modalities

BACKGROUND

Three-dimensional (3D) imaging of the face is being used extensively in medicine for clinical decision making, surgical planning, and research. Nowadays, several companies are offering a broad range of 3D imaging systems, varying in price, method, and mobility. However, most planning and evaluation methods are created and validated solely with one imaging system. Therefore, it is important to analyze possible differences in the 3D surface reconstruction between different systems.

OBJECTIVES

The objective of this study was to analyze differences in the 3D surface reconstruction between three systems: 3dMDface system, Vectra XT, and Artec Eva.

METHODS

Three-dimensional images of the face were acquired from 15 healthy patients with each imaging system. Reproducibility of each device was calculated and a comparison of the Vectra XT and Artec Eva with the 3dMDface was made.

RESULTS

All 3D imaging devices showed high reproducibility, with a mean difference of 0.18 ± 0.15 mm (3dMDface system), 0.15 ± 0.15 mm (Vectra XT), and 0.26 ± 0.24 mm (Artec Eva). No significant difference in reproducibility was found between the Vectra XT and 3dMDface, while a significant difference was found between 3dMDface and Artec Eva, and between Vectra XT and Artec Eva. The mean difference between 3dMDface and Vectra XT was 0.32 ± 0.26 mm. The mean difference between 3dMDface and Artec Eva was 0.44 ± 1.09 mm.

CONCLUSIONS

All three imaging devices showed high reproducibility and accuracy. Although the Artec Eva showed a significant lower reproducibility, the difference found was not clinically relevant. Therefore, using these different systems alongside each other in clinical and research settings is possible.

LEVEL OF EVIDENCE 3

A 3D Mammometric Comparison of Implant-Based Breast Reconstruction With and Without Acellular Dermal Matrix (ADM)

This retrospective study utilizes 3D imaging and mammometrics to compare implant-based breast reconstruction with and without the use of ADM. Previous studies have suggested improved aesthetic outcomes with the use of ADM, but none have been able to quantify this difference. Images were obtained at early and late time points following the expander-implant exchange procedure. Measurements included the point of maximum projection, the superior, inferior, medial and lateral volumetric distribution, and the distance from the point of maximum projection to the inframammary fold along the breast meridian. The patients' demographic information, implant size, and complication rate between the two cohorts were similar. In the early post-operative period, the patients with ADM demonstrated higher medial pole volume; however, this difference did not persist in the late post-operative period. Patients with ADM demonstrated a small but statistically significant greater point of maximum projection and length of lower pole curvature in comparison with the non-ADM cohort. In summary, the results of this study demonstrate improved mammometric measurements when ADM is used in implant-based breast reconstruction, supporting superior aesthetic outcomes in early and late post-operative time points.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The efficacy of lymphaticovenular anastomosis in breast cancer-related lymphedema

Introduction

Lymphedema can be a debilitating condition, causing a great decrease in a person’s quality of life (QoL). Treatment with lymphaticovenular anastomosis (LVA), in which an anastomosis is created between the lymphatic and venous system, may attenuate lymphedema symptoms and reduce swelling. In this study, we share the results using LVA to treat breast cancer-related lymphedema (BCRL) at our institution.

Materials and methods

Patients were eligible for inclusion if they suffered from unilateral BCRL, if functional lymphatics were available, if compression therapy was used for at least 6 months, and if the follow-up was 12 months at minimum. Lymph vessel functionality was assessed preoperatively using indocyanine green (ICG). During surgery, 1–3 anastomoses were created and shunt patency was confirmed using ICG. Arm volumes were measured before surgery and at 6- and 12-month follow-up. QoL was measured before surgery and at 6-month follow-up. Arm volume differences between the healthy arm and affected arm were compared between the time points.

Results

Twenty-nine consecutive female patients with unilateral BCRL were included. The preoperative mean difference in arm volumes was 701 ± 435 ml (36.9%). This was reduced to 496 ± 302 ml (24.7%) at 6-month follow-up (p = 0.00). At 12-month follow-up, the mean difference in arm volume was 467 ± 303 ml (23.5%) (p = 0.02). The overall perceived QoL was increased from 5.8 ± 1.1 to 7.4 ± 0.7 (p = 0.00). The functionality score decreased from 2.2 to 1.8 (p = 0.00), the appearance score decreased from 2.6 to 1.9 (p = 0.00), the symptoms score decreased from 2.8 to 1.8 (p = 0.00), and the mood score decreased from 2.7 to 1.5 (p = 0.00). Fifteen patients (53.6%) were able to discontinue the use of compression garment.

Conclusion

Treatment with LVAs is effective in reducing arm volume difference in patients suffering from BCRL. Although no complete reduction of the edema was achieved at 12-month follow-up, the procedure significantly increased the patients’ QoL.