3D Surface Imaging Research Articles

Validating robotic couch isocentricity with 3D surface imaging.

BackgroundA proton therapy system with 190° gantries uses robotic couch rotations to change the treatment beam laterality. Couch rotations are typically validated clinically with post‐rotation radiographic imaging.AimsThis study assesses the specificity and sensitivity of a commercial 3D surface imaging system, AlignRT (Vision RT, London UK) for validating couch rotations.Materials & MethodsIn clinical operation, a reference surface image of the patient is acquired after radiographic setup with couch at 270°, perpendicular to the gantry axis of rotation. The couch is then rotated ±90° to a typical treatment angle, and AlignRT reports a 3D displacement vector. Patient motion, changes in patient surface, non‐coincidence between AlignRT and couch isocenter, and mechanical couch run‐out all contribute to the 3D vector magnitude. To assess AlignRT sensitivity in detecting couch run‐out, volunteers were positioned orthogonal to the proton gantry and reference surface images were captured without x‐ray localization. Subjects were repeatedly rotated ±90⁰ to typical treatment angles and displacement vectors were recorded. Additionally, measurements were performed in which intentional translations of 2, 4, 6, and 8 mm were combined with the intended isocentric rotations. Data sets were collected using a phantom; subjects with a thoracic isocenter and no immobilization; and subjects with a cranial isocenter and thermoplastic immobilization. A total of 300 rotations were measured.ResultsDuring isocentric rotations, the mean AlignRT displacement vectors for the phantom, immobilized, and non‐immobilized volunteers were 0.1 ± 0.1 mm, 0.8 ± 0.1 mm, and 1.1 ± 0.2 mm respectively. 95% of the AlignRT measurements for the immobilized and non‐immobilized subjects were within 1 mm and 2 mm of the actual displacement respectively.DiscussionAfter characterizing the accuracy using phantoms and volunteers, we have shown that a three‐pod surface imaging system can be used to identify gross non‐isocentric patient rotations. Significant positional deviations, either due to improper couch rotation or patient motion, should be followed by radiographic imaging and repositioning.ConculsionAlignRT can be used to verify patient positioning following couch rotations that are applied after the initial x‐ray guided patient setup. Using a three‐pod AlignRt system, positional deviations exceeding 4 mm were flagged with sensitivity and specificity of 90% and 100% respectively.

Validating 3D indexes in the non-surgical pectus excavatum patient

Background/purposeIn recent years there has been an increased interest in three-dimensional (3D) imaging for the assessment of chest wall deformities. Some studies have proven a correlation between 3D and traditional cross-sectional images but only for patients who already had an indication for a computed tomography (CT) scan prior to surgery; mainly due to their severity. Our aim is to determine the accuracy and reliability of the measures obtained by a portable 3D scanner in a cohort of pectus excavatum (PE) patients with different severity grades, as well as in controls. MethodsWe conducted a study comparing radiological and optical indexes on magnetic resonance imaging (MRI) and 3D surface images. We used a hand-held 3D scanner to obtain the optical Haller Index (3DHI) and Correction Index (3DCI) and a limited MRI scan to obtain the traditional indexes. A statistical analysis was carried out to determine the correlation between optical and radiological measures, plus a subjective severity evaluation. ResultsTwenty-eight patients and controls were enrolled in the study. In both the control and PE groups, there was a significant positive correlation between the indexes, especially for the CI. There were no differences in correlation regarding gender, age or severity. CI appears to better discriminate amongst the different severity groups and controls. Conclusion3D surface imaging is feasible and appropriate to use to assess PE, regardless of the severity or characteristics of the individual patient. Even with a small hand-held device, we can obtain accurate images and measures which are especially useful for the assessment of the nonsurgical pectus patient.

A scoring system for 3D surface images of breast reconstruction developed using the Delphi consensus process

IntroductionEvaluation of aesthetics after breast reconstruction is challenging. In the absence of an objective measurement, panel assessment is widely adopted. Heterogeneity of scales and poor internal consistency make comparison difficult. Development and validation of an expert panel scale using a Delphi consensus process is described. It was designed specifically for use as the gold standard for development of an objective evaluation tool using 3-Dimensional Surface Imaging (3D-SI). Materials and methods20 items relating to aesthetic assessment were identified for consideration in the Delphi consensus process. Items were selected for inclusion in the definitive panel scale by iterative rounds of voting according to importance, consensus discussion, and a final vote. The Delphi-derived scale was tested on a clinical research series for intra- and inter-panellist, and intra-panel reliability, and correlation with Patient Reported Outcome Measures (PROMs). Results61 surgeons participated in the Delphi process. Oncoplastic and plastic surgeons were represented. The Delphi-derived scale included symmetry, volume, shape, position of breast mound, nipple position, and a global score. Intra-panellist reliability ranged from poor to almost perfect (wκ<0to0.86), inter-rater reliability was fair (ICC range 0.4–0.5) for individual items and good (ICC0.6) for the global score, intra-panel reliability was moderate to substantial (wκ0.4–0.7), and correlation with PROMs was moderate (r = 0.5p < 0.01). ConclusionsThe Delphi-derived panel evaluation is at least as good as other scales in the literature and has been developed specifically to provide expert evaluation of aesthetics after breast reconstruction. The logistical constraints of panel assessment remain, reinforcing the need to develop an objective evaluation method.

Quantitative 3-Dimensional Photographic Assessment of Breast Cosmesis After Whole Breast Irradiation for Early Stage Breast Cancer: A Secondary Analysis of a Randomized Clinical Trial

PurposeOur purpose was to use 3-dimensional (3D) surface photography to quantitatively measure breast cosmesis within the framework of a randomized clinical trial of conventionally fractionated (CF) and hypofractionated (HF) whole breast irradiation (WBI); to identify how 3D measurements are associated with patient- and physician-reported cosmesis; and to determine whether objective measures of breast symmetry varied by WBI treatment arm or transforming growth factor β 1 (TGFβ1) status. Methods and MaterialsFrom 2011 to 2014, 287 women age ≥40 with ductal carcinoma in situ or early-stage invasive breast cancer were enrolled in a multicenter trial and randomized to HF-WBI or CF-WBI with a boost. Three-dimensional surface photography was performed at 3 years posttreatment. Patient-reported cosmetic outcomes were recorded with the Breast Cancer Treatment Outcome Scale. Physician-reported cosmetic outcomes were assessed by the Radiation Therapy Oncology Group scale. Volume ratios and 6 quantitative measures of breast symmetry, termed F1-6C, were calculated using the breast contour and fiducial points assessed on 3D surface images. Associations between all metrics, patient- and physician-reported cosmesis, treatment arm, and TGFβ1 genotype were performed using the Kruskal-Wallis test and multivariable logistic regression models. ResultsAmong 77 (39 CF-WBI and 38 HF-WBI) evaluable patients, both patient- and physician-reported cosmetic outcomes were significantly associated with the F1C vertical symmetry measure (both P < .05). Higher dichotomized F1C and volumetric symmetry measures were associated with improved patient- and physician-reported cosmesis on multivariable logistic regression (both P ≤ .05). There were no statistically significant differences in vertical symmetry or volume measures between treatment arms. Increased F6C horizontal symmetry was observed in the CF-WBI arm (P = .05). Patients with the TGFβ1 C-509T variant allele had lower F2C vertical symmetry measures (P = .02). ConclusionsQuantitative 3D image-derived measures revealed comparable cosmetic outcomes with HF-WBI compared with CF-WBI. Our findings suggest that 3D surface imaging may be a more sensitive method for measuring subtle cosmetic changes than global patient- or physician-reported assessments.

Application of Optical Laser 3D Surface imaging system (Sentinel) in breast cancer radiotherapy

It has been clearly confirmed that radiation therapy (RT) after breast conserving surgery (BCS) is an effective treatment modality comparable to mastectomy for early breast cancer. The purpose of this study was to further evaluate the accuracy of 3D surface imaging system (Sentinel) for breast cancer patients received BCS. The optical surface scans and CBCT scans were acquired before and immediately after couch movement correction. The deviation of the CBCT scans from the reference planning CT was considered an estimate for the residual errors for patient setup correction. The planning target volume (PTV) margins for treatment sessions was calculated according to the setup errors. We obtained a total of 245 sets of data collected from 49 breast cancer patients. Compared with Sentinel setup errors, the residual setup errors as determined by the CBCT scans after couch movement correction were reduced in the six directions. The PTV margins derived from the CBCT residual errors were all less than 5 mm in X, Y, and Z directions. Our results suggested that Optical surface imaging can be applied in positioning for breast cancer patient accurately without unnecessary imaging dose.

The Use of a 3D Simulator Software and 3D Printed Biomodels to Aid Autologous Breast Reconstruction.

Aesthetically pleasing and symmetrical breasts are the goal of reconstructive breast surgery. However, multiple procedures are sometimes needed to improve a reconstructed breast's symmetry and appearance. Since all breasts vary in terms of volume, height, width, projection, orientation, and shape, the lack of attention to these details at the moment of flap shaping in autologous reconstruction can lead to poor results. Recent advances in 3-dimensional (3D) surface imaging and printing technologies have allowed for improvement in autologous breast reconstruction symmetry. While 3D printing technology is becoming faster, more accurate, and less expensive, the technology required to obtain proper 3D breast images remains expensive, including laser scanners or 3D photogrammetric cameras. In this study, we present a novel use of an aesthetic surgery simulator software as an affordable alternative to obtaining 3D breast images and creating 3D printed biomodels to aid in the precise shaping of the flap. This approach aims to optimize aesthetic results in autologous breast reconstruction avoiding surgical revisions and reducing surgical times. 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 .

Tailoring the separation performance and antifouling property of polyethersulfone based NF membrane by incorporating hydrophilic CuO nanoparticles

CuO/PES composite membranes were fabricated through phase inversion method, focusing on fouling reduction and improving separation performance. Copper oxide nanoparticles were used as filler additive in the membrane structure. The effect of the embedded CuO nanoparticles on the morphology was studied by considering SEM, SOM and 3D surface images. Flux recovery ratio (FRR%), water contact angle, water content, mechanical tensile strength, porosity and mean pore size, salt rejection and water flux were investigated to evaluate the performance of fabricated membranes. The SOM images showed a uniform surface for the modified membranes. SEM images showed a finger-like structure for the modified membranes. Results also denoted an increment in porosity and mean pore size of membrane at low concentration of CuO NPs, whereas the opposite trend was found at higher concentration of nanoparticles. Utilizing CuO NPs enhanced the membrane tensile strength obviously PWF significantly was improved by applying CuO NPs in membrane matrix. Highest PWF (42.63 L/m2h) was observed for PES-0.05wt% CuO blended membrane, whereas it was 10.41 (L/ m2h) for pristine ones. Salt rejection also measured 82% for virgin membrane and 63-90% for modified membranes. Moreover, FRR% were measured (~77% to ~93%), while the pristine membrane showed ~63% FRR%.

Miniaturized 3D Depth Sensing-Based Smartphone Light Field Camera.

The miniaturization of 3D depth camera systems to reduce cost and power consumption is essential for their application in electrical devices that are trending toward smaller sizes (such as smartphones and unmanned aerial systems) and in other applications that cannot be realized via conventional approaches. Currently, equipment exists for a wide range of depth-sensing devices, including stereo vision, structured light, and time-of-flight. This paper reports on a miniaturized 3D depth camera based on a light field camera (LFC) configured with a single aperture and a micro-lens array (MLA). The single aperture and each micro-lens of the MLA serve as multi-camera systems for 3D surface imaging. To overcome the optical alignment challenge in the miniaturized LFC system, the MLA was designed to focus by attaching it to an image sensor. Theoretical analysis of the optical parameters was performed using optical simulation based on Monte Carlo ray tracing to find the valid optical parameters for miniaturized 3D camera systems. Moreover, we demonstrated multi-viewpoint image acquisition via a miniaturized 3D camera module integrated into a smartphone.

Influence Mechanism of Epoxy Resin and Curing Agent on High-Temperature Performance of Asphalt

To deeply show the internal reasons for the effects of epoxy resin and curing agent on the high-temperature performance of asphalt, nine kinds of asphalt with different content of epoxy resin and curing agent were prepared. On the premise of ensuring that the softening point, penetration and ductility of epoxy asphalt no attenuation, the dynamic shear rheology test and Saybolt viscosity test were used to examine the rutting factor (G*/sin δ), complex shear modulus (G*), phase angle (δ), and viscosity of asphalt with different epoxy resin and curing agent contents. With the help of fluorescence microscopy, microscopic morphology was analyzed, and the micro-image was further analyzed quantitatively by using 3Dsurface and particle statistics. The results show that adding epoxy resin and curing agent into asphalt can significantly improve the rutting factor and complex shear modulus of asphalt and reduce the phase angle and the viscosity growth rate of asphalt changed from fast to slow. Fluorescence and 3Dsurface imaging results indicate when the epoxy resin and the curing agent are uniformly distributed and forms microflocculent structures, the epoxy resin can fully swell in asphalt, and the fluorescence intensity is uniform. The statistical analysis of particles shows that the improvement in high-temperature performance of asphalt by epoxy resin and curing agent results from the distribution of particle area above 26.7346 μm2. The high-temperature performance of epoxy asphalt is optimal when the content of epoxy resin and curing agent is 6 %.

Three-dimensional surface imaging in breast cancer: a new tool for clinical studies?

BackgroundThree-dimensional Surface Imaging (3DSI) is a well-established method to objectively monitor morphological changes in the female breast in the field of plastic surgery. In contrast, in radiation oncology we are still missing effective tools, which can objectively and reproducibly assess and document adverse events in breast cancer radiotherapy within the framework of clinical studies. The aim of the present study was to apply structured-light technology as a non-invasive and objective approach for the documentation of cosmetic outcome and early effects of breast radiotherapy as a proof of principle.MethodsWeekly 3DSI images of patients receiving either conventionally fractionated radiation treatment (CF-RT) or hypofractionated radiation treatment (HF-RT) were acquired during the radiotherapy treatment and clinical follow-up. The portable Artec Eva scanner (Artec 3D Inc., Luxembourg) recorded 3D surface images for the analysis of breast volumes and changes in skin appearance. Statistical analysis compared the impact of the two different fractionation regimens and the differences between the treated and the contralateral healthy breast.ResultsOverall, 38 patients and a total of 214 breast imaging sessions were analysed. Patients receiving CF-RT showed a significantly higher frequency of breast erythema compared to HF-RT (93.3% versus 34.8%, p = 0.003) during all observed imaging sessions. Moreover, we found a statistically significant (p < 0.05) volumetric increase of the treated breast of the entire cohort between baseline (379 ± 196 mL) and follow-up imaging at 3 months (437 ± 224 mL), as well as from week 3 of radiotherapy (391 ± 198 mL) to follow-up imaging. In both subgroups of patients undergoing either CF-RT or HF-RT, there was a statistically significant increase (p < 0.05) in breast volumes between baseline and 3 months follow-up. There were no statistically significant skin or volumetric changes of the untreated healthy breasts.ConclusionsThis is the first study utilizing 3D structured-light technology as a non-invasive and objective approach for the documentation of patients receiving breast radiotherapy. 3DSI offers potential as a non-invasive tool to objectively and precisely monitor the female breast in a radiooncological setting, allowing clinicians to objectively distinguish outcomes of different therapy modalities.

Real-time high-speed three-dimensional surface imaging using band-limited illumination profilometry with a CoaXPress interface.

High-speed three-dimensional (3D) surface imaging by structured-light profilometry is currently driven by numerous applications. However, the limited speeds in fringe pattern projection, image acquisition, and data transmission have strained the existing methods from reaching kilohertz-level acquisition, processing, and display of 3D information during the occurrence of dynamic events (i.e., in real time). To overcome these limitations, we have developed band-limited illumination profilometry (BLIP) with a CoaXPress interface (CI), which enables real-time high-speed 3D surface imaging. We have demonstrated the system's performance by imaging various static and fast-moving 3D objects in real time. We have also applied this system in fluid mechanics by imaging dynamics of a flag, which allowed observation of the wave propagation, gravity-induced phase mismatch, and asymmetric flapping motion. We expect CI-BLIP to find diverse scientific and industrial applications.

Focal-plane three-dimensional imaging method based on temporal ghost imaging: a proof of concept simulation.

A new focal-plane three-dimensional (3D) imaging method based on temporal ghost imaging is proposed and demonstrated. By exploiting the advantages of temporal ghost imaging, this method enables the utilization of slow integrating cameras and facilitates 3D surface imaging within the framework of sequential flood-illumination and focal-plane detection. The depth information is achieved by a temporal correlation between received and reference signals with multiple-shot, and the reflectivity information is achieved by flash imaging with a single-shot. The feasibility and performance of this focal-plane 3D imaging method have been verified through theoretical analysis and numerical experiments.

条纹投影动态三维表面成像技术综述

The dynamic three-dimensional(3D) surface imaging technology based on fringe projection was summarized and the characteristics of typical strategies were analyzed. Firstly, the basic principle of the technique was introduced, including the basic structure of the system, the principle of 3D surface imaging, and the two typical phase extraction methods, phase shifting method and Fourier transform method. Secondly, the dynamic imaging scheme including high speed projection scheme and dynamic 3D surface imaging method using relatively low speed camera was introduced. Thirdly, the absolute phase acquisition methods in dynamic 3D image were introduced, mainly analog and digital coding and area statistical coding, were introduced. Finally, the methods of accurate dynamic phase measurement were introduced.

Automated Robot-based Large-Scale 3D Surface Imaging

Abstract This work develops a robot-based automated 3D imaging system for large-scale surface measurement at high resolution. The system has the advantages of allowing 1) high-resolution 3D surface imaging based on photometric stereo, and 2) automatic stitching of multiple images collected by a robot for large-scale surface measurement. We developed a dome-shaped image acquisition system with 16 individually controlled lights, mounted on a robot (Kuka iiwa lbr). A photometric stereo with a lighting selection mechanism is used for the reconstruction of local surface regions. To allow image stitching for large-scale surface measurement, one challenge arises from the robot arm’s limited encoder precision and accuracy, which is about ±150 µm for its repeatability and even lower for its nominal accuracy. This is unsuitable for the applications of surface metrology or inspection. To compensate the errors introduced by the chained robot arm’s encoders, for image stitching, we experimented with two feature descriptors extracted from the normal and the curvature space respectively, and performed comparative studies with standard feature descriptors from the standard grey-scale intensity space. The normal-based feature descriptor demonstrated advantages of illumination invariance while the curvature-based feature descriptor demonstrated clear advantages of rotation invariance, and feasibility of aligning multiple images with high accuracy.

Three dimensional (3D) imaging techniques in orthodontics-An update.

3D imaging is a technique which develops or creates the impression of depth within an image by deploying 2D data into 3-dimensional format. To aid in quality regulating processes for industrial purposes, 3D imaging has become an extremely valuable factor. Owing to their various drawbacks, a wide range of investigative methods formulated for demonstration of facial structures and the dentition were dilapidated. Currently in medicine, the most prevalent method is perhaps 3D imaging technique renders thorough and problem specific information regarding hard and the soft tissues, such as Computerized Tomography (CT), Cone Beam Computerized Tomography (CBCT), Micro Computerized Tomography (MCT), 3D laser scanning, structured light technique, stereophotogrammetry or 3D surface imaging systems (3dMD), 3D facial morphometry (3DFM), Tuned Aperture Computed Tomography (TACT), and Magnetic Resonance Imaging (MRI). 3D imaging techniques in orthodontics plays an important role by facilitating more elaborated diagnostic information on the precise cases like patients having craniofacial anomalies. Hence, the aim of this study was to review advances in 3D imaging with in the field of orthodontics.

Designing a New Endoscope for Panoramic-View with Focus-Area 3D-Vision in Minimally Invasive Surgery

PurposeThe minimally invasive surgery (MIS) has shown advantages when compared to traditional surgery. However, there are two major challenges in the MIS technique: the limited field of view (FOV) and the lack of depth perception provided by the standard monocular endoscope. Therefore, in this study, we proposed a New Endoscope for Panoramic-View with Focus-Area 3D-Vision (3DMISPE) in order to provide surgeons with a broad view field and 3D images in the surgical area for real-time display.MethodThe proposed system consisted of two endoscopic cameras fixed to each other. Compared to our previous study, the proposed algorithm for the stitching videos was novel. This proposed stitching algorithm was based on the stereo vision synthesis theory. Thus, this new method can support 3D reconstruction and image stitching at the same time. Moreover, our approach employed the same functions on reconstructing 3D surface images by calculating the overlap region’s disparity and performing image stitching with the two-view images from both the cameras.ResultsThe experimental results demonstrated that the proposed method can combine two endoscope’s FOV into one wider FOV. In addition, the part in the overlap region could also be synthesized for a 3D display to provide more information about depth and distance, with an error of about 1 mm. In the proposed system, the performance could achieve a frame rate of up to 11.3 fps on a single Intel i5-4590 CPU computer and 17.6 fps on a computer with an additional GTX1060 Nvidia GeForce GPU. Furthermore, the proposed stitching method in this study could be made 1.4 times after when compared to that in our previous report. Besides, our method also improved stitched image quality by significantly reducing the alignment errors or “ghosting” when compared to the SURF-based stitching method employed in our previous study.ConclusionThe proposed system can provide a more efficient way for the doctors with a broad area of view while still providing a 3D surface image in real-time applications. Our system give promises to improve existing limitations in laparoscopic surgery such as the limited FOV and the lack of depth perception.

Communicating 3D data-interactive 3D PDF documents for expert reports and scientific publications in the field of forensic medicine.

Modern forensic investigations increasingly revert to 3D imaging techniques, such as computed tomography, magnetic resonance imaging, and 3D surface imaging. Findings are therefore often based on 3D data sets; however, this information is commonly reported and communicated within 2D imagery. The use of interactive 3D PDFs is already established in the scientific community but has yet to be implemented in the field of forensic medicine. Three example cases were chosen to serve as exemplary data for the most commonly applied imaging techniques in postmortem imaging. 3D surface models were created from postmortem magnetic resonance imaging (PMMR), postmortem computed tomography (PMCT), and 3D surface imaging data sets. PMMR revealed a space-occupying subdural hemorrhage that led to ipsilateral compression of the brain tissue of the right hemisphere. PMCT displayed a defect in the skull on the left side of the temporal bone. 3D surface imaging data displayed a patterned discoloration on the inside of the left forearm. Interactive 3D PDFs offer the possibility to communicate 3D information to the reader while maintaining all the benefits of a regular 2D PDF. With Adobe Acrobat, the reader can interactively navigate through 3D data sets and create sufficient depth cues to generate a realistic 3D perception of the data. The interactive 3D PDF is a useful extension of standard 2D PDFs and has the potential to communicate 3D data to the reader in a more complete, more comprehensible, and less subjective manner than 2D PDFs.

Registration and fusion of 3D surface data from CT and ToF camera for position verification in radiotherapy

The purpose of this study is to introduce a low-cost method for verification of patient positioning before and during irradiation in radiotherapy. The experiments strategy is implemented by using a phantom like a human head in two modes: with and without thermoplastic masks. Radiotherapy is an effective clinical option for topical tumors treatment. Ability to the monitoring and control the patient’s position during treatment is among the important items in radiotherapy. We registered to modality of 3D surface image in point cloud format, dynamic 3D image of time-of-flight camera (includes outer shape of head) and static 3D image of CT slice sectional by coherent point drift algorithm. Accuracy of 3D surface registration was calculated by average symmetrical surface distances (ASD) that it is a new method based on surface distance. The mean ASD calculated for rotation around X and Y axes of phantom is 2.62 ± 0.97 mm with immobilized thermoplastic mask and accuracy be increased to 1.69 ± 0.88 mm in non-thermoplastic mode. By performing paired T tests for ASDs, it was found that the use of a thermoplastic mask does not make a significant difference in the data acquisition. By developing this research to image fusion of that’s 3D data sets, we will design to augmented reality in radiotherapy for verification of treatment planning and compare it with the electronic portal imaging device.

Preoperative breast volume evaluation of one-stage immediate breast reconstruction using three-dimensional surface imaging and a printed mold.

Accurate assessment of breast volume is an essential component of preoperative planning in one-stage immediate breast reconstruction (IBR) for achieving breast symmetry and a satisfactory cosmetic outcome. In this study, we compared breast volume estimation using three-dimensional (3D) surface imaging with magnetic resonance imaging (MRI) to determine the accuracy of breast volume measurements. Further, a 3D printing mold for facilitating autologous breast reconstruction intraoperatively is described. Patients scheduled to therapeutic or prophylactic mastectomy with one-stage IBR, either by autologous tissue transfer or direct implant, from 2016 to 2019, were enrolled in this study. 3D surface image and MRI were performed to evaluate breast volume and shape. The results were validated by the water displacement volume of the mastectomy specimen. Finally, a 3D printing mold was designed for breast reconstruction with autologous tissue. Nineteen women who were scheduled to have 20 mastectomies (18 unilateral and one bilateral) were included. There was a strong linear association between breast volume measured using the two different methods and water displacement of mastectomy specimens when a Pearson correlation was used (3D surface image: r = 0.925, p < 0.001; MRI: r = 0.915, p < 0.001). Bland-Altman plots demonstrated no proportional bias between the assessment methods. The coefficient of variation was 52.7% for 3D surface imaging and 59.9% for MRI. The volume of six breasts was evaluated by both measurements and the intraclass correlation coefficient was 0.689 for 3D surface image (p = 0.043) and 0.743 for MRI (p = 0.028). Using 3D surface image to evaluate breast shape and volume is a quick, effective, and convenient method. The accuracy, reproducibility, and reliability of 3D surface imaging were comparable with MRI in our study. In addition, 3D-printed molds can achieve better symmetry and aesthetic outcomes in immediate autologous breast reconstructions.

Molding Helmet Therapy for Deformational Brachycephaly

Molding helmet therapy is used for the treatment of infants with deformational brachycephaly (DB). There is a lack of rigorous outcome measures of helmet therapy in patients with DB using 3-dimensional (3D) imaging, with most reports rely on either subjective or 2-dimensional analyses. Furthermore, the longitudinal assessment of head shape improvement over the course of helmet therapy has not been documented. Our goal was to assess the outcome of molding helmet therapy using 3D surface imaging, and to document the pace of improvement during treatment. The head shape of 18 infants with DB who underwent orthotic molding helmet therapy was assessed. The 3D scans were obtained before treatment, during treatment, and at the end of treatment. First, we applied shape analysis techniques based on template deformation to obtain average (composite) heads of the 18 patients at the 3 time points of treatment (pretreatment, during, and posttreatment). In addition, we used 3D curvature analysis to quantify the degree of flatness at the same time points. Molding helmet therapy started at 6.7 ± 0.9 months of age and lasted for 4.3 ± 0.8 months. The overall difference in the occipital contour between pretreatment and end of treatment was 6.3 ± 1.7 mm. Curvature analysis revealed that 15% of the back of the head had prehelmet marked flatness (mean curvature <5/m), which decreased to 9% at 2.5 months into treatment and 7% at the end of treatment. Over 65% of the head shape improvement occurred during the 2.5 months of molding helmet therapy.