[Breast volume assessment based on 3D surface geometry: verification of the method using MR imaging]

The triangular prism approximation method for volume estimation of deep inferior epigastric artery perforator flap in breast reconstruction

BACKGROUND

Many methods to predict the amount of tissue needed for breast reconstruction have been reported, but some require complicated software and special systems. The purpose of this report was to present a simpler method for predicting the volume required for deep inferior epigastric artery perforator (DIEP) flaps. The accuracy of this method was evaluated based on both actual flap design and computed tomography.

METHODS

The weight and horizontal (x cm) and vertical (y cm) lengths of the DIEP flap were recorded, and the maximum thickness of subcutaneous tissue (z cm) was measured from computed tomography in 36 cases of breast reconstruction using DIEP flap in our hospital performed between January 2019 and December 2020. Flap volume was calculated using three methods of approximation: triangular prisms using physical and CT measurements (1/2xyz cm³ ); quadrangular and triangular prisms using physical and CT measurements (3/4xyz cm³ ); and a previously reported method using measurements from CT angiography alone and calculation with a standard mathematical formula. These three groups were compared using Bland-Altman plots and intraclass correlation coefficients (ICCs) to assess consistency between predicted and measured values.

RESULTS

On Bland-Altman plots, values were distributed almost randomly around the average value of the difference, and no proportional error was evident in the methods. The ICC between predicted and actual values of triangular prisms using physical and CT measurements was largest: ICC (1, 2) = 0.978 (0.825-0.981; 95% confidence interval for ICC). A sufficient flap volume was able to be transplanted in all cases.

CONCLUSION

The methods presented appear useful to calculate flap volume closer to the measured value without complicated software systems. These results suggest that the method using two symmetric triangular prisms could predict volume more easily than previously reported methods and may facilitate good breast reconstruction.

Reliability and Measurement Error of Breast Volume Calculation Using Three-Dimensional Surface Imaging

Background: Breast lymphedema after breast cancer is challenging to quantify. Three-dimensional (3D) surface imaging is one available technique to measure breast volume, however, the measurement properties of available software programs have not been fully determined. The aim of this study was to determine equivalency of measurements with two software programs as well as reliability, standard error of measurement (SEM), and smallest detectable change (SDC). Methods and Results: Retrospective three-dimensional surface imaging (3D-SI) of 100 breasts taken before or after breast conserving surgery for breast cancer were retrieved for reliability analysis. Three assessors followed a standardized measurement technique using two software programs, Vectra^® 3D Analysis Module (VAM) and Breast Sculptor^®. Mean breast volume was 489.9 ± 206 cc using VAM and 480.1 ± 229.1 cc using Breast Sculptor. Lin's concordance showed poor agreement between programs (0.81-0.88). Measurements using VAM had excellent intra- and inter-rater reliability with SEM = 4.1% for one assessor and 8.7% for multiple assessors. Breast Sculptor also had excellent intra-rater and substantial inter-rater reliability but the SEM was much larger at 14.5% (intra-rater) and 19.1% (inter-rater). The SDC value was lowest for VAM and a single rater with 56 cc indicating a meaningful change beyond measurement error. Conclusion: Breast volume measurements captured with 3D-SI using VECTRA-XT are highly reliable, but the volumes, SEM, and SDC varied between the two software programs. Measurement error was lowest with VAM software. Although the usefulness of VECTRA-XT and VAM software to detect change in breast volume is promising, further solutions to reduce measurement error are required to improve clinical utility to measure breast lymphedema.

Nonsubjective Assessment of Shape, Volume and Symmetry during Breast Augmentation with Handheld 3D Device

Three-dimensional Surface Imaging (3DSI) has become a valuable tool for planning and documenting surgical procedures. Although surface scanners have allowed for a better understanding of breast shape, size, and asymmetry during patient consultation, its use has not been included in intraoperative assessment so far. Validation of the reliability of the intraoperative use of a portable handheld 3DSI equipment as a tool to evaluate morphological changes during breast augmentation surgery. The patients who underwent bilateral subpectoral breast augmentation through an inframammary incision were included in this study. Intraoperative 3DSI was performed with the Artec Eva device, allowing for visualization of the surgical area before incision, after use of breast sizers and implant, and after wound closure. Intraoperatively manual measurements of breast distances and volume changes due to known sizer and implant volumes were in comparison with digital measurements calculated from 3DSI of the surgical area. Bilateral breasts of 40 patients were 3D photographed before incision and after suture successfully. A further 108 implant sizer uses were digitally documented. There was no significant difference between manual tape measurement and digital breast distance measurement. Pre- to postoperative 3D volume change showed no significant difference to the known sizer and implant volume.

Volumetry in Breast Reconstruction: Always New, Always Better?

Although breast surgeries for aesthetic or reconstructive purposes are regularly performed, no focus has been laid on establishing an adequate and reliable volumetry method. While CT and MRI scan represent methods that are already in clinical use, the 3D scan  is a novel and promising tool, easy to use with the possibility to measure the anatomic breast volume in an upright position. Nevertheless, its reliability is broadly underinvestigated. LEVEL OF EVIDENCE V : 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 .

Intraoperative 3D Comparison of Round and Anatomical Breast Implants: Dispelling a Myth

Background: Thanks to 3D imaging, it is possible to measure the influence of different parameters on breast augmentation. In this study, we compare the effect of different shapes and sizes of breast implants on the topography of the resulting breast. Furthermore, the impact of different breast implants on inter-landmark distances and on changes of the nipple position was assessed. Methods: This interventional prospective study was carried out on 10 female patients after collecting informed consent. 3D scans of the native and augmented breasts were performed intraoperatively with small, medium, and large sizes of both anatomical and round implants, resulting in a total of n = 130 single breast scans. These scans were analyzed for topographic shift quantification, nipple migration, and inter-landmark distances of the breast. Results: Implant size, but not implant shape leads to significant topographic shifts of the breast (p < 0.001 and p = 0.900, respectively). Both round and anatomical implants lead to a significantly higher volumetric increase in the upper quadrants compared to the lower quadrants (p < 0.001). Nipple migration into the superomedial quadrant was seen in about 90% of augmentations. No evident differences in inter-landmark distances were observed when round and anatomical implants of different sizes were compared. Conclusions: Implant size rather than shape influences the postoperative aesthetic results. No significant difference in topographic shift was found comparing round and anatomical implants, suggesting that both implant shapes result in comparable aesthetic outcomes.

An Intraoperative Measurement Method of Breast Symmetry Using Three-Dimensional Scanning Technique in Reduction Mammaplasty

BACKGROUND

Intraoperative symmetrical assessment plays a decisive role in the aesthetic results of reduction mammaplasty, but it depends mostly on the surgeons' experience that may be biased by individual subjective factors. This study was intended to propose an objective method based on a hand-held three-dimensional (3D) scanner to assist intraoperative symmetrical assessment, aiming to achieve better aesthetic results in reduction mammaplasty.

METHODS

Sixty patients were enrolled in the study from April 2018 to January 2020. Intraoperative 3D scanning was routinely performed on 29 patients (study group) to assist symmetrical adjustments during breast shaping. 3D surface scanning data of both groups were obtained at 3 months postoperatively to objectively assess breast symmetry. Postoperative symmetry scores in five aspects, including nipple-areolar complex position, inframammary-fold height, breast size, shape, and footprint, were rated by six independent observers based on anonymized photographs to subjectively evaluate pre- and postoperative breast symmetry of the two groups.

RESULTS

The bilateral breast volume difference of the study group was significantly smaller than the control group (39.1 vs. 113.3 cm³, p = 0.001), as well as the difference in nipple to inframammary-fold distance (2.79 vs. 7.43 mm, p = 0.01). The observer-reported results showed that breast reduction significantly improved postoperative symmetry in all five aspects compared with preoperative symmetry in the study group (P<0.001). Furthermore, postoperative symmetrical ratings of all five aspects in the study group were statistically better than the control group (P<0.05).

CONCLUSIONS

Intraoperative 3D scanning provided a reliable method to assist symmetry adjustments and ensure better postoperative breast symmetry in reduction mammaplasty.

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 .

New strategies for targeting kinase networks in cancer

Targeted strategies against specific driver molecules of cancer have brought about many advances in cancer treatment since the early success of the first small-molecule inhibitor Gleevec. Today, there are a multitude of targeted therapies approved by the Food and Drug Administration for the treatment of cancer. However, the initial efficacy of virtually every targeted treatment is often reversed by tumor resistance to the inhibitor through acquisition of new mutations in the target molecule, or reprogramming of the epigenome, transcriptome, or kinome of the tumor cells. At the core of this clinical problem lies the assumption that targeted treatments will only be efficacious if the inhibitors are used at their maximum tolerated doses. Such aggressive regimens create strong selective pressure on the evolutionary progression of the tumor, resulting in resistant cells. High-dose single agent treatments activate alternative mechanisms that bypass the inhibitor, while high-dose combinatorial treatments suffer from increased toxicity resulting in treatment cessation. Although there is an arsenal of targeted agents being tested clinically and preclinically, identifying the most effective combination treatment plan remains a challenge. In this review, we discuss novel targeted strategies with an emphasis on the recent cross-disciplinary studies demonstrating that it is possible to achieve antitumor efficacy without increasing toxicity by adopting low-dose multitarget approaches to treatment of cancer and metastasis.

The current progress and critical analysis of three-dimensional scanning and three-dimensional printing applications in breast surgery

Background

Several attempts have been made to develop a tool capable of evaluating breast shape and volume to aid surgical planning and outcome assessment. More recently, newer technologies such as three-dimensional (3D) scanning and 3D printing have been applied in breast assessment. The aim of this study was to review the literature to assess the applicability of 3D scanning and 3D printing in breast surgery.

Methods

A literature search was carried on PubMed, Google Scholar and OVID from January 2000 to December 2019 using the keywords ‘3D’, ‘Three-dimensional’, ‘Three/four dimensions’ and ‘Breast’.

Results

A total of 6564 articles were identified initially; the abstracts of 1846 articles were scanned, and 81 articles met the inclusion criteria and were included in this review. Articles were reviewed and classified according to their aims, study subjects, the software and hardware used, main outcomes and major limitations.

Conclusions

These technologies are fast and easy to use, however, high costs, long processing times and the need for training might limit their application. To incorporate these technologies into standard healthcare, their efficacy and effectiveness must be demonstrated through multiple and rigorous clinical trials.

Improved accuracy of breast volume calculation from 3D surface imaging data using statistical shape models

Background

Three-dimensional (3D) scanning is an established method of breast volume estimation. However, this method can never be entirely precise, since the thoracic wall cannot be imaged by the surface scanner. Current methods rely on interpolation of the posterior breast border from the surrounding thoracic wall. Here, we present a novel method to calculate the posterior border and increase the accuracy of the measurement.

Methods

Using principal component analysis, computed tomography images were used to build a statistical shape model (SSM) of the thoracic wall. The model was fitted to 3D images and the missing thoracic wall curvature interpolated (indirect volumetry). The calculations were evaluated by ordinary least squares regression between the preoperative and postoperative volume differences and the resection weights in breast reduction surgery (N = 36). Also, an SSM of the breast was developed, allowing direct volumetry. Magnetic-resonance images (MRI) and 3D scans were acquired from 5 patients in order to validate the direct 3D volumetry.

Results

Volumetry based on a SSM exhibited a higher determination coefficient (R² = 0,737) than the interpolation method (R² = 0,404). The methods were not equivalent (p = 0.75), suggesting that the methods significantly differ. There was no influence of BMI on the correlation in either method. The MRI volumetry had a strong correlation with the 3D volumetry (R² = 0,978).

Conclusion

The SSM-based method of posterior breast border calculation is reliable and superior to the currently used method of interpolation. It should serve as a basis of software applications aiming at calculation of breast volume from 3D surface scanning data.

Chances and limitations of a low-cost mobile 3D scanner for breast imaging in comparison to an established 3D photogrammetric system

BACKGROUND

In search of new possibilities in 3D surface imaging, several nonmedical scanning systems have been assessed for their implementation in plastic surgery. The aim of this study was to compare a new affordable 3D imaging consumer product with an established medical 3D imaging system for objective 3D breast imaging.

METHOD

We compared a low-cost mobile, handheld scanner against an established medical 3D surface imaging system. Forty-two female patients who underwent different types of breast surgery were captured in a 3D view with both devices. Digital breast measurement, volume measurement, and breast surface-to-surface analysis were done using Mirror software. Repeatability was assessed by repeated 3D scans of the torso and surface-to-surface analysis.

RESULTS

Digital breast measurement showed low differences with good-to-excellent correlation between both devices. Mean breast volume difference was small (-5.11 ± 32.10 mL) within the 95% limits of agreement. Surface-to-surface analysis yielded a higher surface deviation in the lower breast quadrants (1.62 ± 0.80 mm root mean square [RMS] error and 1.81 ± 0.88 mm RMS error) than in the upper breast quadrants. Repeatability was satisfactory with a mean of 0.636 ± 0.279 mm RMS error.

CONCLUSION

Affordable mobile surface scanners may offer new perspectives in the future for 3D breast imaging. Although surface acquisition was sufficient for breast measurements in comparison to an established system, the lack of appropriate medical software for patient consultation next to moderate texture quality needs to be improved for wider acceptance in plastic surgery.

Gestation-Specific Changes in the Anatomy and Physiology of Healthy Pregnant Women: An Extended Repository of Model Parameters for Physiologically Based Pharmacokinetic Modeling in Pregnancy

BACKGROUND

In the past years, several repositories for anatomical and physiological parameters required for physiologically based pharmacokinetic modeling in pregnant women have been published. While providing a good basis, some important aspects can be further detailed. For example, they did not account for the variability associated with parameters or were lacking key parameters necessary for developing more detailed mechanistic pregnancy physiologically based pharmacokinetic models, such as the composition of pregnancy-specific tissues.

OBJECTIVES

The aim of this meta-analysis was to provide an updated and extended database of anatomical and physiological parameters in healthy pregnant women that also accounts for changes in the variability of a parameter throughout gestation and for the composition of pregnancy-specific tissues.

METHODS

A systematic literature search was carried out to collect study data on pregnancy-related changes of anatomical and physiological parameters. For each parameter, a set of mathematical functions was fitted to the data and to the standard deviation observed among the data. The best performing functions were selected based on numerical and visual diagnostics as well as based on physiological plausibility.

RESULTS

The literature search yielded 473 studies, 302 of which met the criteria to be further analyzed and compiled in a database. In total, the database encompassed 7729 data. Although the availability of quantitative data for some parameters remained limited, mathematical functions could be generated for many important parameters. Gaps were filled based on qualitative knowledge and based on physiologically plausible assumptions.

CONCLUSION

The presented results facilitate the integration of pregnancy-dependent changes in anatomy and physiology into mechanistic population physiologically based pharmacokinetic models. Such models can ultimately provide a valuable tool to investigate the pharmacokinetics during pregnancy in silico and support informed decision making regarding optimal dosing regimens in this vulnerable special population.

Assessment of Breast Asymmetry in Adolescent Idiopathic Scoliosis Using an Automated 3D Body Surface Measurement Technique

STUDY DESIGN

Cohort study.

OBJECTIVES

To assess breast asymmetry (BA) directly with 3D surface imaging and to validate it using MRI values from a cohort of 30 patients with significant adolescent idiopathic scoliosis (AIS). Also, to study the influence of posture (prone vs standing) on BA using the automated method on both modalities.

SUMMARY OF BACKGROUND DATA

BA is a common concern in young female patients with AIS. In a previous study using MRI, we found that the majority of patients with significant AIS experienced BA of up to 21% in addition to their chest wall deformity. MRI is costly and not always readily available. 3D surface topography, which offers fast and reliable breast acquisitions without radiation or distortion of the body surface, is an alternative method in the clinical setting.

METHODS

Thirty patients with AIS were enrolled in the study on the basis of their thoracic curvature, skeletal and breast maturity, without regard to their perception of their BA. Each patient underwent two imaging studies of their torso: a 3D trunk surface topography and a breast MRI. An automated breast volume measuring method was proposed using a program developed with Matlab programming.

RESULTS

Strong correlations were obtained when comparing the proposed method to the MRI on the left breast volumes (LBV) (r = 0.747), the right breast volumes (RBV) (r = 0.805) and the BA (r = 0.614). Using the same method on both imaging modalities also yielded strong correlation coefficients on the LBV (r = 0.896), the RBV (r = 0.939) and the BA (r = 0.709).

CONCLUSIONS

The proposed 3D body surface automated measurement technique is feasible clinically and correlates very well with breast volumes measured using MRI. Additionally, breast volumes remain comparable despite being measured in different body positions (standing and prone) in a young cohort of AIS patients.

LEVEL OF EVIDENCE

Level IV.

An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions

BACKGROUND

Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available nowadays, we can combine information to preoperatively plan the optimal flap volume to be harvested. In this proof-of-concept, we investigated whether projection of a virtual flap planning onto the patient's abdomen using a projection method could result in harvesting the correct flap volume.

METHODS

In six patients (n = 9 breasts), 3D stereophotogrammetry and CTA data were combined from which a virtual flap planning was created comprising perforator locations, blood vessel trajectory and flap size. All projected perforators were verified with Doppler ultrasound. Intraoperative flap measurements were collected to validate the determined flap delineation volume.

RESULTS

The measured breast volume using 3D stereophotogrammetry was 578 ± 127 cc; on CTA images, 527 ± 106 cc flap volumes were planned. The nine harvested flaps weighed 533 ± 109 g resulting in a planned versus harvested flap mean difference of 5 ± 27 g (flap density 1.0 g/ml). In 41 out of 42 projected perforator locations, a Doppler signal was audible.

CONCLUSION

This proof-of-concept shows in small numbers that flap volumes can be included into a virtual DIEP flap planning, and transferring the virtual planning to the patient through a projection method results in harvesting approximately the same volume during surgery. In our opinion, this innovative approach is the first step in consequently achieving symmetric breast volumes in DIEP flap breast reconstructions.

A novel fully automatic measurement of apparent breast volume from trunk surface mesh

This paper presents a novel method for assessing apparent breast volume from trunk surface mesh without any manual intervention. The proposed method requires a closed and smooth triangular mesh of the trunk. It comprises four main steps: automatic nipple localization, automatic breasts delineation, chest-wall interpolation and volume computation. The mean curvature is computed for each vertex using a quadratic fitting approach and used as an indicator to determine the convex fold of the breasts. The delineation is modeled as an ellipse in the frontal plane and all the vertices inside it are removed. The remaining ones are used to interpolate the chest wall with radial basis functions. The voxels inside the resulting mesh without breasts are then subtracted from the original voxelized volume to generate the breasts volume. The validation is conducted on 30 adolescent female for each of which an MRI and a trunk surface (TS) acquisitions were available. Three breast volumes are considered: the anatomical volumes (AV) manually segmented on the MRI, the external volumes computed with the proposed method first in prone position (EVP) using the trunk mesh extracted from the MRI, and second, in standing position (EVS) using the TS's mesh. Significant correlations (R> 0.77) are found between each two of the three volumes. AVs are much larger than both EVS and EPS. In fact, the manual segmentation using MRI slices allows for a direct visualization of the breast posterior delineation. Computed automatically, EVS and EPS are highly similar, indicating that the proposed method is robust to changes from prone to standing position. No significant difference between the regressions on the left and right breasts is noted. Fully-automatic 3D breast volumetry from trunk surface mesh is feasible and provides measurements that are highly correlated to manual MRI volumetry and robust to changes in posture.

Breast volumetric analysis for aesthetic planning in breast reconstruction: a literature review of techniques

BACKGROUND

Accurate volumetric analysis is an essential component of preoperative planning in both reconstructive and aesthetic breast procedures towards achieving symmetrization and patient-satisfactory outcome. Numerous comparative studies and reviews of individual techniques have been reported. However, a unifying review of all techniques comparing their accuracy, reliability, and practicality has been lacking.

METHODS

A review of the published English literature dating from 1950 to 2015 using databases, such as PubMed, Medline, Web of Science, and EMBASE, was undertaken.

RESULTS

Since Bouman's first description of water displacement method, a range of volumetric assessment techniques have been described: thermoplastic casting, direct anthropomorphic measurement, two-dimensional (2D) imaging, and computed tomography (CT)/magnetic resonance imaging (MRI) scans. However, most have been unreliable, difficult to execute and demonstrate limited practicability. Introduction of 3D surface imaging has revolutionized the field due to its ease of use, fast speed, accuracy, and reliability. However, its widespread use has been limited by its high cost and lack of high level of evidence. Recent developments have unveiled the first web-based 3D surface imaging program, 4D imaging, and 3D printing.

CONCLUSIONS

Despite its importance, an accurate, reliable, and simple breast volumetric analysis tool has been elusive until the introduction of 3D surface imaging technology. However, its high cost has limited its wide usage. Novel adjunct technologies, such as web-based 3D surface imaging program, 4D imaging, and 3D printing, appear promising.

Three-Dimensional Imaging for Breast Augmentation: Is This Technology Providing Accurate Simulations?

BACKGROUND

For patients considering breast augmentation, 3-dimensional (3D) imaging provides a preoperative simulation of the postoperative result. However, the clinical accuracy of these simulations has not been assessed.

OBJECTIVE

The authors compared preoperative simulations with postoperative results of breast augmentation to permit more informed decisions about breast augmentation.

METHODS

To determine differences between simulations and actual results, volumetric and contour analyses were performed for patients who underwent 3D imaging both preoperatively and 3 months after breast augmentation. All patients received round smooth silicone implants or anatomically shaped cohesive silicone gel implants; the mean volume was 295 cc.

RESULTS

Twenty patients (40 breasts) underwent 3D imaging both pre- and postoperatively. There were no procedural complications or revisions. The mean difference between preoperative simulation and postoperative breast volume was 27.2 cc (range, 1.4-99.5 cc), representing a 9.2% mean difference in volume and an accuracy of 90.8%. The mean absolute difference (root mean square) of all surface points along the breast in aggregate was 4.0 mm (range, 1.8-8.3 mm). No specific location along the surface contour of the breast could be identified as having the greatest differences.

CONCLUSIONS

The preoperative simulation provided by 3D imaging is >90% accurate in predicting postoperative breast volume. The mean absolute differential for surface contour in this study was 4 mm, representing 98.4% accuracy based on average surface area.

LEVEL OF EVIDENCE

3.

Three-dimensional prediction of free-flap volume in autologous breast reconstruction by CT angiography imaging

PURPOSE

The diagnostic use of computer tomography angiography (CTA) to identify perforating blood vessels for abdominal free-flap breast reconstruction was extended to estimate the three-dimensional (3D) preoperative flap volume and to compare it with the real intraoperative flap weights in order to (1) evaluate the accuracy of CTA-based 3D flap volume prediction, and (2) to analyze abdominal tissue estimation for required breast volume reconstruction.

METHODS

Preoperative CTA was performed in 54 patients undergoing unilateral breast reconstruction with a free, deep, inferior epigastric artery perforator flap. 3D flap volumes ([Formula: see text]) based on CTA data were calculated and compared with the actual intraoperative flap weight (g). In addition, a breast volume to flap volume ratio was calculated to analyze whether the estimated 3D abdominal flap volume would match that of the breast to be removed.

RESULTS

40 CTA data sets (74.1 %) fulfilled the technical requirements for a reliable determination of flap volume. 3D CTA flap volume prediction showed no relevant differences to the actual flap weight (p = 0.44) and high correlations (r = 0.998, [Formula: see text]), allowing a prediction accuracy within 0.29 [Formula: see text] 3.0 % (range: from [Formula: see text]8.77 to 5.67 %) of the real flap weight. Significantly larger flap volumes were harvested compared with the actually required breast volumes ([Formula: see text]), leading to an average of 21 % of the remnant flap tissue potentially being discarded.

CONCLUSIONS

CTA-based 3D flap volume prediction provides accurate preoperative guidelines concerning the needed amount of abdominal tissue that can be harvested to achieve acceptable symmetry.

Autologous fat transplantation: volumetric tools for estimation of volume survival. A systematic review

Autologous fat transplantation has gained great recognition in aesthetic and reconstructive surgery. Two main aspects are of predominant importance for progress control after autologous fat transplantation to the breast: quantitative information about the rate of fat survival in terms of effective volume persistence and qualitative information about the breast tissue to exclude potential complications of autologous fat transplantation. There are several tools available for use in evaluating the rate of volume survival. They are extensively compared in this review. The anthropometric method, thermoplastic casts, and Archimedes' principle of water displacement are not up to date anymore because of major drawbacks, first and foremost being reduced reproducibility and exactness. They have been replaced by more exact and reproducible tools such as MRI volumetry or 3D body surface scans. For qualitative and quantitative progress control, MRI volumetry offers all the necessary information: evaluation of fat survival and diagnostically valuable imaging to exclude possible complications of autologous fat transplantation. For frequent follow-up, e.g., monthly volume analysis, repeated MRI exams would not be good for the patient and are not cost effective. In these cases, 3D surface imaging is a good tool and especially helpful in a private practice setting where fast data acquisition is needed. This tool also offers the possibility of simulating the results of autologous fat transplantation.

LEVEL OF EVIDENCE V

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 .

Prediction of breast resection weight in reduction mammaplasty based on 3-dimensional surface imaging

Prediction of resection weight (RW) in reduction mammaplasty is helpful in achieving breast symmetry and in fulfilling the stringent reimbursement requirements of health insurance companies. Current breast volume estimations are largely based on surgeon's experience, which are partially unreliable and often cumbersome to obtain. Therefore, this study aims to develop a formula to predict RW based on 3D surface imaging. A total of 68 breasts were treated with bilateral T-scar, and 40 breasts were treated with bilateral or unilateral vertical-scar reduction mammaplasty. Linear distances and volume measurements were assessed 3-dimensionally preoperatively and 6 months postoperatively. Significant correlations between the RW and the calculated preoperative breast volume (ρ = 0.804) and the sternal notch to nipple distance (ρ = 0.839) were found in both techniques (P < .001). Regression equations with the RW were performed to derive prediction formulas. Surgeons may benefit from the formulas in terms of improvement in preoperative planning, dealing with insurance coverage questions, and optimizing patient consultation.

Three-dimensional evaluation of breast augmentation and the influence of anatomic and round implants on operative breast shape changes

BACKGROUND

Currently, postoperative outcome analysis in breast augmentation is essentially subjective, and objective evaluation of treatment efficacy is lacking. This study evaluates the influence of anatomic and round implant parameters on breast contour changes after subpectoral breast augmentation using three-dimensional (3D) surface imaging.

METHODS

3D surface breast scans of 17 patients (34 breasts) undergoing subpectoral breast augmentation with round implants and of ten patients (20 breasts) receiving anatomic implants via an axillary approach under endoscopic assistance or a submammary fold incision were obtained before and 6 months postoperatively. 3D linear distance, breast volume, and surface measurement were correlated with the implanted round and anatomic implant parameters, and the resulting breast shape changes were evaluated.

RESULTS

Total breast volume changed in correlation with the implant size (2.4% difference; r=0.894; p<0.001). Implant volume and type influence the nipple-to-inframammary fold distance (N-IMF). Every inserted 100 ml implant volume enlarges the N-IMF distance by 0.8 cm (anatomic>round; p=0.01). Postoperatively, the IMF dropped by an average of 1.3 cm for round implants and by 1.1 cm for anatomic implants, without relevant differences between the applied surgical incision and the selected implants (p>0.05). Breast projection increased significantly more with anatomic implants (2.4 cm) than with round implants (1.7 cm) (p=0.01). The breast projection increase was 22% less than expected for round implants and 25% less than expected for anatomic implants based on the manufacturer implant parameters (p<0.01), without essential differences regarding the surgical incision.

CONCLUSIONS

3D breast shape changes induced by round and anatomic implants after subpectoral augmentation mammaplasty are objectively documented including breast projection, volume, and N-IMF distance changes. 3D surface imaging may have a potential clinical contribution to objective surgical outcome research.

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 at www.springer.com/00266.

Breast volumetry using a three-dimensional surface assessment technique

BACKGROUND

Breast volume is a relevant measure for the prevention and prediction of diseases and for aesthetic surgery. This study evaluated a new technique to determine breast volume and compared measures using a three-dimensional (3D) body surface scanner and magnetic resonance imaging (MRI) scans, with the latter used as the standard method.

METHODS

Both MRI scans and body surface 3D scans were obtained from 22 women. For each method, breast volumes were assessed. The MRI calculations of the breast volumes were performed by a specially trained radiologist using analysis software. A textured 3D image was generated by a calibrated digital texture camera after breast surface data acquisition. The volume assessment of the 3D photography was calculated using a software package after manual outlining of the breast and automated projection of a dorsal limit. Linear regression was used to predict the MRI volume assessment with the 3D image volume assessment.

RESULTS

The mean breast volume according to MRI volumetry was 442.8 ml on the left side and 471.8 ml on the right side. The mean breast volume using a 3D body surface volume assessment method was 273.8 ml (observer A) and 226.2 ml (observer B) on the left side and 284.4 ml (observer A) and 234.9 ml (observer B) on the right side. The use of linear regression models showed R (2) values of 0.59-0.77. The mean time for MRI recording and volume assessment was 68.0 ± 14.1 min for both sides and 11.6 ± 1.5 min for 3D recording and volume assessment.

CONCLUSIONS

The 3D surface-based volume measurements are feasible in terms of time and can predict the MRI breast volume with sufficient accuracy. This might facilitate the broad use of such an assessment technique in a large-scale epidemiologic study using breast volume as a study aim. Additionally, further development of volume assessments could help to implement this technique in breast surgery procedures.

Objective breast symmetry evaluation using 3-D surface imaging

This study develops an objective breast symmetry evaluation using 3-D surface imaging (Konica-Minolta V910(®) scanner) by superimposing the mirrored left breast over the right and objectively determining the mean 3-D contour difference between the 2 breast surfaces. 3 observers analyzed the evaluation protocol precision using 2 dummy models (n = 60), 10 test subjects (n = 300), clinically tested it on 30 patients (n = 900) and compared it to established 2-D measurements on 23 breast reconstructive patients using the BCCT.core software (n = 690). Mean 3-D evaluation precision, expressed as the coefficient of variation (VC), was 3.54 ± 0.18 for all human subjects without significant intra- and inter-observer differences (p > 0.05). The 3-D breast symmetry evaluation is observer independent, significantly more precise (p < 0.001) than the BCCT.core software (VC = 6.92 ± 0.88) and may play a part in an objective surgical outcome analysis after incorporation into clinical practice.