Main Factors Influencing The Measurement Of Breast Volume Change And Its Standardization Using Three-Dimensional Breast Imaging

BackgroundCurrently,the only objective indicator for clinical evaluation of the efficacy of autologous fat grafting in breast augmentation is volume retention rate.Three-dimensional(3D)imaging is one of the most commonly used methods for establishing this index.Due to the inconsistent methods for measurement,however,the volume retention rates reported by different studies greatly vary.We have found that during the measuring process the respiratory state,arm position,and menstrual cycle(MC)are main factors affecting the measurement of breast volume change(BVC).This study aims to analyze and standardize the above factors in order to ultimately propose a relatively objective,accurate and stable method for measuring BVC.Objective1.Using the 3D imaging technique,we aimed to analyze the effect of respiratory state on breast volume difference(BVD)in breast augmentation using autologous fat grafting and compare the breast volume change error(BVCE)for different respiratory states.Following this,we aimed to propose a standard respiratory state for measuring volume retention rate with the 3D breast imaging technique.2.Using the 3D imaging technique,we aimed to analyze the effect of arm position on BVD in breast augmentation using autologous fat grafting and compare the BVCE for different arm positions.After that,a standardized arm position will be proposed for measuring volume retention rate with the 3D breast imaging technique.3.Using the 3D imaging technique,we aimed to investigate the trend of BVC during a MC and establish whether there is a significant difference in BVC between different stages of a MC.Comparing the BVC during the same period of two consecutive MC,a stable period was established for measuring volume retention rate using the 3D breast imaging technique.The correlation between basic breast volume and maximum BVC during a MC was analyzed.Methods1.Patients undergoing breast augmentation with autologous fat grafting in our department were selected for the first part of the study.Preoperative 3D breast imaging was performed at the end of inspiration(EI)and end of expiration(EE).Scans on each respiratory phase were repeated on the first day post surgery,taking four scans in total.BVD and breast projection variation(BPV)were compared before and after surgery.The patients planning to receive mammaplasty in our department were selected for the second part of this study.Two repeated 3D scans were performed at El and EE,and then the BVCE was compared.2.Patients undergoing breast augmentation with autologous fat grafting in our department were selected for the first part of this study.Preoperative 3D breast imaging was performed at three different arm positions:at the sides,akimbo and with hands on the head.Scans on each arm position were repeated on the first day post surgery,taking six scans in total.BVD was compared before and after surgery.The patients planning to receive mammaplasty in our department were selected for the second part of this study.Two repeated 3D scans were performed at the sides,akimbo and hands on the head,and then the BVCE was compared.3.Young female patients with regular MCs underwent 3D breast imaging on the first day of the MC.One group of subjects underwent 8 sessions of regular 3D breast imaging in one MC and another group of subjects underwent 16 sessions in two consecutive MC.The basic breast volume and BVC in different periods were measured for each subject.The trend of BVC in one MC was described.Preovulatory phase and postovulatory phase values in one MC were compared.After that,the BVC during the same period of two consecutive MC was compared.A Pearson's linear correlated analysis was performed to identify the correlation between basic breast volume and maximum range of BVC during a MC.Results1.A total of 25 patients(n=50 breasts)undergoing breast augmentation with autologous fat grafting was included.For the patients who received 100-200 ml fat injection,the average BVD at El was 120.9 ± 43.1 ml,and the average BVD at EE was 137.1 ± 39.8 ml.There was a statistically significant difference between the two groups(p=0.02);for the patients who received more than 200 ml fat injection,the average BVD at El was 191.0±62.4 ml,and the average BVD at EE was 187.7 ± 60.1 ml.There was no statistically significant difference between those groups(p=0.75).For the patients who received 100-200 ml fat injection,the average BPV at El was 1.3 ± 0.4 cm,and the average BPV at EE was 1.6 ± 0.4 cm.There was a statistically significant difference between the two groups(p<0.001);for the patients who received more than 200 ml fat injection,the average BPV at El was 1.7 ± 0.7 cm,and the average BPV at EE was 1.8 ± 0.8 cm.There was no statistically significant difference between the two groups(p=0.45).26 patients(n=52 breasts)planning to receive mammaplasty were included.The median of BVCE was 9.6 ml for two consecutive El and the median of BVCE was 10.6 ml for two consecutive EE,which did not show significant difference(p=0.08).2.25 patients(n=50 breasts)undergoing breast augmentation with autologous fat grafting were included.For the patients who received 100-200 ml fat injection,the median of BVD with hands at the sides was 135.6 ml,the median of BVD at the akimbo position was 125.8 ml and the median of BVD with the hands on the head was 119.2 ml.There was a statistically significant difference for the BVD between arm position at the sides and hands on the head(p=0.003);there was also a statistically significant difference for the average BVD between arm position at the akimbo position and hands on the head(p=0.01).For patients receiving more than 200 ml fat injection,the median of BVD with hands at the sides was 177.7 ml,the median of BVD at the akimbo position was 174.6 ml and the median of BVD with hands on the head was 152.6 ml.There was no statistically significant difference between the groups(p>0.05).26 patients(n=52 breasts)planning to receive mammaplasty were included.The median of BVCE was 11.2 ml for two consecutive 3D scans with the arm position at the sides,10.6 ml at the akimbo position,and 8.4 ml with hands on the head,which did not show significant difference(p=0.19).3.A total of 26 women who met the inclusion criteria participated in this part of study.Of these,13 subjects(26 breasts)underwent 3D breast imaging during one MC,and the remaining 13 subjects(26 breasts)underwent 3D breast imaging for two consecutive MC.The mean age of the subjects was 24.8 ± 4.8 years.During the MC,the breast volume first showed a falling trend followed by a rise.A significant difference in the BVC was noted between the preovulatory and postovulatory phase(-19.6 ± 2.1 ml pre-ovulation vs.-6.9±3.3 ml post-ovulation,p=0.002).The comparison of BVC during two consecutive MCs revealed a relatively stable breast volume in the late luteal phase and early follicle phase.There was a positive linear association between basic breast volume and maximum range of BVC when a Pearson correlation was used(r=0.45,p=0.02).Conclusions1.The respiratory state,to some extent,especially in patients receiving a lower volume of fat grafting,affects BVC after breast augmentation with autologous fat grafting.Therefore,we recommend maintenance of a preselected,consistent respiratory state during 3D breast imaging to measure BVC.EE could serve as this standard respiratory state in 3D breast imaging.2.The arm position,to some extent,again particularly for patients receiving less fat grafting,affects the BVC after breast augmentation using autologous fat grafting.Consequently,arm position must remain consistent when using 3D breast imaging to measure BVC.We recommend the akimbo position as a standard arm position in 3D breast imaging.3.Due to the fluctuation of hormone levels in the female MC,the breast volume also changes accordingly.There is a significant difference in breast volume between preovulatory phase and postovulatory phase in one MC,which can affect the measurement of BVC after breast augmentation using fat grafting.The BVC in the late luteal phase and early follicular phase is relatively stable.Hence,we recommended performing 3D breast imaging during the aforementioned two periods to increase comparability among different studies.