3D Surface Imaging Research Articles

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

Study designCohort study. ObjectivesTo 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 dataBA 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. MethodsThirty 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. ResultsStrong 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). ConclusionsThe 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 EvidenceLevel IV.

Genome-wide association study of facial morphology reveals novel associations with FREM1 and PARK2.

Several studies have now shown evidence of association between common genetic variants and quantitative facial traits in humans. The reported associations generally involve simple univariate measures and likely represent only a small fraction of the genetic loci influencing facial morphology. In this study, we applied factor analysis to a set of 276 facial linear distances derived from 3D facial surface images of 2187 unrelated individuals of European ancestry. We retained 23 facial factors, which we then tested for genetic associations using a genome-wide panel of 10,677,593 single nucleotide polymorphisms (SNPs). In total, we identified genome-wide significant (p < 5 × 10−8) associations in three regions, including two that are novel: one involving measures of midface height at 6q26 within an intron of PARK2 (lead SNP rs9456748; p = 4.99 × 10−8) and another involving measures of central upper lip height at 9p22 within FREM1 (lead SNP rs72713618; p = 2.02 × 10−8). In both cases, the genetic association was stronger with the composite facial factor phenotype than with any of the individual linear distances that comprise those factors. While the biological role of PARK2 in the craniofacial complex is currently unclear, there is evidence from both mouse models and Mendelian syndromes that FREM1 may influence facial variation. These results highlight the potential value of data-driven multivariate phenotyping for genetic studies of human facial morphology.

Three-dimensional surface scanners compared with standard anthropometric measurements for head shape

Three-dimensional (3D) surface imaging devices designed to capture and quantify craniofacial surface morphology are becoming more common in clinical environments. Such scanners overcome the limitations of two-dimensional photographs while avoiding the ionizing radiation of computed tomography. The purpose of this study was to compare standard anthropometric cranial measurements with measurements taken from images acquired with 3D surface scanners.Two 3D scanners of different cost were used to acquire head shape data from thirteen adult volunteers: M4D scan and Structure Sensor. Head circumference and cephalic index were measured directly on the patients as well as on 3D scans acquired with the two scanners. To compare head volume measurements with a gold standard, magnetic resonance imaging scans were used. Repeatability and accuracy of both devices were evaluated.Intra-rater repeatability for both scanners was excellent (intraclass correlation coefficients > 0.99, p < 0.001). Direct and digital measures of head circumference, cephalic index and head volume were strongly correlated (0.85 < r < 0.91, p < 0.001). Compared to direct measurements, accuracy was highest for M4D scan.Both 3D scanners provide reproducible data of head circumference, cephalic index and head volume and show a strong correlation with traditional measurements. However, care must be taken when using absolute values.

Three- and four-dimensional mapping of speech and language in patients with epilepsy.

We have provided 3-D and 4D mapping of speech and language function based upon the results of direct cortical stimulation and event-related modulation of electrocorticography signals. Patients estimated to have right-hemispheric language dominance were excluded. Thus, 100 patients who underwent two-stage epilepsy surgery with chronic electrocorticography recording were studied. An older group consisted of 84 patients at least 10 years of age (7367 artefact-free non-epileptic electrodes), whereas a younger group included 16 children younger than age 10 (1438 electrodes). The probability of symptoms transiently induced by electrical stimulation was delineated on a 3D average surface image. The electrocorticography amplitude changes of high-gamma (70-110 Hz) and beta (15-30 Hz) activities during an auditory-naming task were animated on the average surface image in a 4D manner. Thereby, high-gamma augmentation and beta attenuation were treated as summary measures of cortical activation. Stimulation data indicated the causal relationship between (i) superior-temporal gyrus of either hemisphere and auditory hallucination; (ii) left superior-/middle-temporal gyri and receptive aphasia; (iii) widespread temporal/frontal lobe regions of the left hemisphere and expressive aphasia; and (iv) bilateral precentral/left posterior superior-frontal regions and speech arrest. On electrocorticography analysis, high-gamma augmentation involved the bilateral superior-temporal and precentral gyri immediately following question onset; at the same time, high-gamma activity was attenuated in the left orbitofrontal gyrus. High-gamma activity was augmented in the left temporal/frontal lobe regions, as well as left inferior-parietal and cingulate regions, maximally around question offset, with high-gamma augmentation in the left pars orbitalis inferior-frontal, middle-frontal, and inferior-parietal regions preceded by high-gamma attenuation in the contralateral homotopic regions. Immediately before verbal response, high-gamma augmentation involved the posterior superior-frontal and pre/postcentral regions, bilaterally. Beta-attenuation was spatially and temporally correlated with high-gamma augmentation in general but with exceptions. The younger and older groups shared similar spatial-temporal profiles of high-gamma and beta modulation; except, the younger group failed to show left-dominant activation in the rostral middle-frontal and pars orbitalis inferior-frontal regions around stimulus offset. The human brain may rapidly and alternately activate and deactivate cortical areas advantageous or obtrusive to function directed toward speech and language at a given moment. Increased left-dominant activation in the anterior frontal structures in the older age group may reflect developmental consolidation of the language system. The results of our functional mapping may be useful in predicting, across not only space but also time and patient age, sites specific to language function for presurgical evaluation of focal epilepsy.

Comparison of morphology and topography of surfaces of WEDM machined structural materials

Abstract Wire Electric Discharge Machining (WEDM) is an unconventional machining technology using physical principles to cut materials. There are many factors affecting this process and having a fundamental influence on the final quality of the machined surface. Apart from the dielectric and wire electrode type used, these include, in particular, the machine setting parameters such as discharge current, gap voltage, pulse on and off time, and wire feed. Another very significant aspect of the machining process is mechanical and physical characteristics of the machined material including its heat treatment. This study deals with an analysis of morphology and topology of the surfaces of samples made of 4 structural materials and their 5 types of heat treatment. The analysis was carried out using electron microscopy (SEM) and a contact-less 3D profilometer which allowed evaluating the profile and surface parameters of surface quality including creating a 3D surface image.

Mechanical Trap Surface‐Enhanced Raman Spectroscopy for Three‐Dimensional Surface Molecular Imaging of Single Live Cells

AbstractReported is a new shell‐based spectroscopic platform, named mechanical trap surface‐enhanced Raman spectroscopy (MTSERS), for simultaneous capture, profiling, and 3D microscopic mapping of the intrinsic molecular signatures on the membrane of single live cells. By leveraging the functionalization of the inner surfaces of the MTs with plasmonic gold nanostars, and conformal contact of the cell membrane, MTSERS permits excellent signal enhancement, reliably detects molecular signatures, and allows non‐perturbative, multiplex 3D surface imaging of analytes, such as lipids and proteins on the surface of single cells. The demonstrated ability underscores the potential of MTSERS to perform 3D spectroscopic microimaging and to furnish biologically interpretable, quantitative, and dynamic molecular maps in live cell populations.

Mechanical Trap Surface-Enhanced Raman Spectroscopy for Three-Dimensional Surface Molecular Imaging of Single Live Cells.

Reported is a new shell-based spectroscopic platform, named mechanical trap surface-enhanced Raman spectroscopy (MTSERS), for simultaneous capture, profiling, and 3D microscopic mapping of the intrinsic molecular signatures on the membrane of single live cells. By leveraging the functionalization of the inner surfaces of the MTs with plasmonic gold nanostars, and conformal contact of the cell membrane, MTSERS permits excellent signal enhancement, reliably detects molecular signatures, and allows non-perturbative, multiplex 3D surface imaging of analytes, such as lipids and proteins on the surface of single cells. The demonstrated ability underscores the potential of MTSERS to perform 3D spectroscopic microimaging and to furnish biologically interpretable, quantitative, and dynamic molecular maps in live cell populations.

Early Changes in Facial Profile Following Structured Filler Rhinoplasty: An Anthropometric Analysis Using a 3-Dimensional Imaging System.

Quantitative measurements are important for objective evaluation of postprocedural outcomes. Three-dimensional (3D) imaging is known as an objective, accurate, and reliable system for quantifying the soft tissue dimensions of the face. To compare the preprocedural and acute postprocedural nasofrontal, nasofacial, nasolabial, and nasomental angles, early changes in the height and length of the nose, and nasal volume using a 3D surface imaging with a light-emitting diode. The 3D imaging analysis of 40 Korean women who underwent structured nonsurgical rhinoplasty was conducted. The 3D assessment was performed before, immediately after, 1 day, and 2 weeks after filler rhinoplasty with a Morpheus 3D scanner (Morpheus Co., Seoul, Korea). There were significant early changes in facial profile following nonsurgical rhinoplasty with a hyaluronic acid filler. An average increase of 6.03° in the nasofrontal angle, an increase of 3.79° in the nasolabial angle, increase of 0.88° in the nasomental angle, and a reduction of 0.83° in the nasofacial angle was observed at 2 weeks of follow-up. Increment in nasal volume and nose height was also found after 2 weeks. Side effects, such as hematoma, nodules, and skin necrosis, were not observed. The 3D surface imaging quantitatively demonstrated the early changes in facial profile after structured filler rhinoplasty. The study results describe significant acute spatial changes in nose shape following treatment.

VirtoScan - a mobile, low-cost photogrammetry setup for fast post-mortem 3D full-body documentations in x-ray computed tomography and autopsy suites.

Injuries such as bite marks or boot prints can leave distinct patterns on the body's surface and can be used for 3D reconstructions. Although various systems for 3D surface imaging have been introduced in the forensic field, most techniques are both cost-intensive and time-consuming. In this article, we present the VirtoScan, a mobile, multi-camera rig based on close-range photogrammetry. The system can be integrated into automated PMCT scanning procedures or used manually together with lifting carts, autopsy tables and examination couch. The VirtoScan is based on a moveable frame that carries 7 digital single-lens reflex cameras. A remote control is attached to each camera and allows the simultaneous triggering of the shutter release of all cameras. Data acquisition in combination with the PMCT scanning procedures took 3:34min for the 3D surface documentation of one side of the body compared to 20:20min of acquisition time when using our in-house standard. A surface model comparison between the high resolution output from our in-house standard and a high resolution model from the multi-camera rig showed a mean surface deviation of 0.36mm for the whole body scan and 0.13mm for a second comparison of a detailed section of the scan. The use of the multi-camera rig reduces the acquisition time for whole-body surface documentations in medico-legal examinations and provides a low-cost 3D surface scanning alternative for forensic investigations.

Palliative radiation therapy for superior vena cava syndrome in metastatic Wilms tumor using 10XFFF and 3D surface imaging to avoid anesthesia in a pediatric patient—a teaching case

Palliative radiation therapy for superior vena cava syndrome in metastatic Wilms tumor using 10XFFF and 3D surface imaging to avoid anesthesia in a pediatric patient—a teaching case

A Markerless 3D Computerized Motion Capture System Incorporating a Skeleton Model for Monkeys

In this study, we propose a novel markerless motion capture system (MCS) for monkeys, in which 3D surface images of monkeys were reconstructed by integrating data from four depth cameras, and a skeleton model of the monkey was fitted onto 3D images of monkeys in each frame of the video. To validate the MCS, first, estimated 3D positions of body parts were compared between the 3D MCS-assisted estimation and manual estimation based on visual inspection when a monkey performed a shuttling behavior in which it had to avoid obstacles in various positions. The mean estimation error of the positions of body parts (3–14 cm) and of head rotation (35–43°) between the 3D MCS-assisted and manual estimation were comparable to the errors between two different experimenters performing manual estimation. Furthermore, the MCS could identify specific monkey actions, and there was no false positive nor false negative detection of actions compared with those in manual estimation. Second, to check the reproducibility of MCS-assisted estimation, the same analyses of the above experiments were repeated by a different user. The estimation errors of positions of most body parts between the two experimenters were significantly smaller in the MCS-assisted estimation than in the manual estimation. Third, effects of methamphetamine (MAP) administration on the spontaneous behaviors of four monkeys were analyzed using the MCS. MAP significantly increased head movements, tended to decrease locomotion speed, and had no significant effect on total path length. The results were comparable to previous human clinical data. Furthermore, estimated data following MAP injection (total path length, walking speed, and speed of head rotation) correlated significantly between the two experimenters in the MCS-assisted estimation (r = 0.863 to 0.999). The results suggest that the presented MCS in monkeys is useful in investigating neural mechanisms underlying various psychiatric disorders and developing pharmacological interventions.

The 3D Facial Norms Database: Part 1. A Web-Based Craniofacial Anthropometric and Image Repository for the Clinical and Research Community.

With the current widespread use of three-dimensional (3D) facial surface imaging in clinical and research environments, there is a growing demand for high-quality craniofacial norms based on 3D imaging technology. The principal goal of the 3D Facial Norms (3DFN) project was to create an interactive, Web-based repository of 3D facial images and measurements. Unlike other repositories, users can gain access to both summary-level statistics and individual-level data, including 3D facial landmark coordinates, 3D-derived anthropometric measurements, 3D facial surface images, and genotypes from every individual in the dataset. The 3DFN database currently consists of 2454 male and female participants ranging in age from 3 to 40 years. The subjects were recruited at four US sites and screened for a history of craniofacial conditions. The goal of this article is to introduce readers to the 3DFN repository by providing a general overview of the project, explaining the rationale behind the creation of the database, and describing the methods used to collect the data. Sex- and age-specific summary statistics (means and standard deviations) and growth curves for every anthropometric measurement in the 3DFN dataset are provided as a supplement available online. These summary statistics and growth curves can aid clinicians in the assessment of craniofacial dysmorphology.

Development of a multi-wavelength diffuse optical tomography system for early diagnosis of rheumatoid arthritis: simulation, phantoms and healthy human studies.

A multi-wavelength diffuse optical tomography (DOT) system has been developed to directly extract physiological information, such as total haemoglobin concentration, from tissue in human hand joints. Novel methods for 3D surface imaging and spectrally constrained image reconstruction are introduced and their potential application to imaging of rheumatoid arthritis is discussed. Results are presented from simulation studies as well as experiments using phantoms and data from imaging of three healthy volunteers. The image features are recovered partially for phantom data using transmission measurements only. Images that reveal joint regions and surrounding features within the hand are shown to co-register with co–acquired ultrasound images which are shown to be related to total haemoglobin concentration.

The pressure sensitivity of wrinkled B-doped nanocrystalline diamond membranes.

Nanocrystalline diamond (NCD) membranes are promising candidates for use as sensitive pressure sensors. NCD membranes are able to withstand harsh conditions and are easily fabricated on glass. In this study the sensitivity of heavily boron doped NCD (B:NCD) pressure sensors is evaluated with respect to different types of supporting glass substrates, doping levels and membrane sizes. Higher pressure sensing sensitivities are obtained for membranes on Corning Eagle 2000 glass, which have a better match in thermal expansion coefficient with diamond compared to those on Schott AF45 glass. In addition, it is shown that larger and more heavily doped membranes are more sensitive. After fabrication of the membranes, the stress in the B:NCD films is released by the emergence of wrinkles. A better match between the thermal expansion coefficient of the NCD layer and the underlying substrate results in less stress and a smaller amount of wrinkles as confirmed by Raman spectroscopy and 3D surface imaging.

Dosimetric Comparison of Deep Inspiration Breath Hold and Free Breathing Treatment Techniques for Left-sided Breast Cancer Using 3-Dimensional Surface Tracking

While radiation therapy has been shown to increase local control and overall survival for breast cancer, cardiac toxicity remains a concern. Morbidity and mortality have been shown to increase proportionally to the mean heart dose. Deep inspiration breath hold (DIBH) can reduce heart dose compared to free-breathing (FB) delivery by increasing the distance from the heart to the chest wall, especially in left-sided breast cancer. DIBH requires monitoring of patients' respiratory motion. We report our experience with DIBH in left breast and chest-wall irradiation using 3D optical surface tracking. Thirty patients were treated using DIBH with a surface tracking system that provides a real time 3D surface image of the patient. This image is registered with the patient's body contour to facilitate setup and provide real time position offsets. Treatment plans were created on FB and DIBH images to compare doses to the heart and lungs. The distance between the heart and chest wall was measured at the 7th thoracic vertebra at 11 cm anterior to the spinal canal. Unpaired t-test was used to compare means and mean differences in heart and lung doses between plans. Correlation coefficients were derived for anatomic variances, such as heart and chest wall separation as well as heart and lung volumes. A comparison of DIBH and FB plans showed a decrease in mean and maximum heart doses in all patients. Individual patients’ mean heart doses decreased by an average of 1.12 Gy, and the average mean heart dose for DIBH plans was significantly lower than for FB plans (1.02 vs 2.12 Gy; P<0.0001). When lumpectomy and mastectomy patients were separated, this statistical significance was maintained in each group (P<0.0001 and P = 0.0233, respectively). Maximum heart dose decreased by an average of 11.88 Gy and was significantly lower in DIBH plans versus FB plans (28.33 vs 43.7 Gy; P = 0.0001). The average difference in heart to chest-wall separation between DIBH and FB images was 2.41 cm. This difference correlated positively with mean (R = 0.24) and maximum (R = 0.51) heart doses. While a trend towards improved left lung V20 was noted (14.04 vs 15.78%; P = 0.057), a significant difference was noted only for intact breast patients treated with opposed tangents alone (12.25 vs 15.06 Gy; P = 0.0257) versus plans with additional regional nodal radiation fields. Heart volume did not correlate with any measurements. However, DIBH left lung volume and the measured increase in volume on inspiration inversely correlated with maximum heart dose (R = 0.39) and left lung V20 (R = 0.32). DIBH with 3D surface tracking can significantly benefit patients with left sided disease by limiting the mean and maximum heart dose. In addition, DIBH showed a trend in improving lung V20 in intact breast patients treated with tangents alone. DIBH appears to be a viable option to reduce heart dose for left sided breast cancer patients and thus potentially reduce long-term complications without prolonging treatment delivery.

Computation of breast ptosis from 3D surface scans of the female torso

Stereophotography is now finding a niche in clinical breast surgery, and several methods for quantitatively measuring breast morphology from 3D surface images have been developed. Breast ptosis (sagging of the breast), which refers to the extent by which the nipple is lower than the inframammary fold (the contour along which the inferior part of the breast attaches to the chest wall), is an important morphological parameter that is frequently used for assessing the outcome of breast surgery. This study presents a novel algorithm that utilizes three-dimensional (3D) features such as surface curvature and orientation for the assessment of breast ptosis from 3D scans of the female torso. The performance of the computational approach proposed was compared against the consensus of manual ptosis ratings by nine plastic surgeons, and that of current 2D photogrammetric methods. Compared to the 2D methods, the average accuracy for 3D features was ~13% higher, with an increase in precision, recall, and F-score of 37%, 29%, and 33%, respectively. The computational approach proposed provides an improved and unbiased objective method for rating ptosis when compared to qualitative visualization by observers, and distance based 2D photogrammetry approaches.

Abstract: The “Boomerang Lift”: A 3-Step Compartment Based Approach to the Youthful Cheek

DISCLOSURE/FINANCIAL SUPPORT: None of the authors has a financial interest in any of the products, devices, or drugs mentioned in this manuscript. BACKGROUND: Autologous fat grafting (AFG) is an important tool for plastic surgeons when approaching the aging face. Malar augmentation restores the youthful facial contour and provides support to the lower lid. The existence of distinct facial fat compartments suggests a step-wise approach to facial augmentation is needed1. Our group recently described the unique surface response for targeted volumization of discrete fat compartments, termed “Augmentation Zone” (AZ), for the deep malar compartments using three-dimensional (3D) surface imaging in a cadaveric model.2 The Boomerang Lift is the three-step approach to malar augmentation using the ideal combination of deep malar fat compartments in clinical patients. METHODS: Clinical patients undergoing AFG for malar augmentation where injected in the Boomerang Lift technique and photographed intra-operatively using 3D surface imaging (Canfield® VECTRA H1) (n=13). Sequential injections were performed in the following order: to the lateral sub-orbicularis oculi fat (lateral SOOF), medial SOOF, and lastly to the deep medial cheek. Intra-operative 3D images were taken at baseline and following compartmental injections. Overlay between the augmented and baseline surfaces were performed using 3D analytic software, and the AZ was defined for individual and combined fat compartments. RESULTS: 3D analysis of the Boomerang Lift technique resulted in a unique AZ consistent across patients. The AZ resembled a boomerang, with the short tail supporting the medial lower lid, and the long tail extending laterally along the zygomatic arch. The upper border was restricted by the level of the tear trough/lid-cheek junction, and the lower border was defined medially by the nasolabial fold and laterally by the level of the zygomatico-cutaneous ligament. Injections to the lateral and medial SOOF defined the boundaries of the boomerang shape, while the injection to the deep medial cheek provided maximum projection. CONCLUSIONS: This is the first clinical application of the deep malar augmentation zones described in a cadaveric model. The Boomerang Lift resulted in a reproducible surface shape that respected the previously defined boundaries in a cadaveric model. 3D surface imaging was an ideal method for analyzing the surface change in response to targeted facial fat grafting. As we continue to understand the 3D architecture of the facial fat compartments, we will be able to describe a surgical algorithm for injection. 1. Rohrich RJ, Pessa JE: The Fat Compartments of the Face: Anatomy and Clinical Implications for Cosmetic Surgery. Plastic and Reconstructive Surgery 2007, 119:2219 - 2227. 2. Stern CS, Schreiber JE, Surek CL, Garfein ES, Jelks EB, Jelks GW, Tepper OM: 3D Topographical Surface Changes in Response to Compartmental Volumization of the Medial Cheek; Defining a Malar “ Augmentation Zone”. Plast Reconstr Surg 2016.

Genome-Wide Association Study Reveals Multiple Loci Influencing Normal Human Facial Morphology.

Numerous lines of evidence point to a genetic basis for facial morphology in humans, yet little is known about how specific genetic variants relate to the phenotypic expression of many common facial features. We conducted genome-wide association meta-analyses of 20 quantitative facial measurements derived from the 3D surface images of 3118 healthy individuals of European ancestry belonging to two US cohorts. Analyses were performed on just under one million genotyped SNPs (Illumina OmniExpress+Exome v1.2 array) imputed to the 1000 Genomes reference panel (Phase 3). We observed genome-wide significant associations (p < 5 x 10−8) for cranial base width at 14q21.1 and 20q12, intercanthal width at 1p13.3 and Xq13.2, nasal width at 20p11.22, nasal ala length at 14q11.2, and upper facial depth at 11q22.1. Several genes in the associated regions are known to play roles in craniofacial development or in syndromes affecting the face: MAFB, PAX9, MIPOL1, ALX3, HDAC8, and PAX1. We also tested genotype-phenotype associations reported in two previous genome-wide studies and found evidence of replication for nasal ala length and SNPs in CACNA2D3 and PRDM16. These results provide further evidence that common variants in regions harboring genes of known craniofacial function contribute to normal variation in human facial features. Improved understanding of the genes associated with facial morphology in healthy individuals can provide insights into the pathways and mechanisms controlling normal and abnormal facial morphogenesis.

The Application of Three-Dimensional Surface Imaging System in Plastic and Reconstructive Surgery.

Three-dimensional (3D) surface imaging system has gained popularity worldwide in clinical application. Unlike computed tomography and magnetic resonance imaging, it has the ability to capture 3D images with both shape and texture information. This feature has made it quite useful for plastic surgeons. This review article is mainly focusing on demonstrating the current status and analyzing the future of the application of 3D surface imaging systems in plastic and reconstructive surgery.Currently, 3D surface imaging system is mainly used in plastic and reconstructive surgery to help improve the reliability of surgical planning and assessing surgical outcome objectively. There have already been reports of its using on plastic and reconstructive surgery from head to toe. Studies on facial aging process, online applications development, and so on, have also been done through the use of 3D surface imaging system.Because different types of 3D surface imaging devices have their own advantages and disadvantages, a basic knowledge of their features is required and careful thought should be taken to choose the one that best fits a surgeon's demand.In the future, by integrating with other imaging tools and the 3D printing technology, 3D surface imaging system will play an important role in individualized surgical planning, implants production, meticulous surgical simulation, operative techniques training, and patient education.

Three-dimensional surface imaging by multi-frequency phase shift profilometry with angle and pattern modeling for system calibration

In this paper, we present a 3D surface imaging system based on the well-known phase shift profilometry. To yield the analytical solutions, four shifted phases and three high carrier frequencies are used to compute the phase map and reduce the noises that are caused by the inherent optical aberrations and external influences, e.g. different illumination light sources, uneven intensity distribution and automatic image processing algorithms. To reduce the system noise, we propose to model the pattern of the calibration grid in a virtual space. To obtain the modeled pattern, we use a plane to intercept the rays that are modeled by the proposed angle modeling method. In the world coordinate system, the angle and the pattern are computed based on the calibration data. A registration method is used to transform the modeled pattern in the virtual space to the ideal pattern in the world coordinate system by computing the least squared errors between the true points in the modeled pattern and the measured points in the practical pattern. The modeled (true) points are used for re-calibration of the 3D imaging system. Experimental results showed that the measurement accuracy increases considerably and the MSE is reduced from 0.95 mm to 0.65 mm (32% average error decrease) after replacing the measured points with the true points for calibration.