Inverse Scattering Problem and Microwave Mammography

Judgement of nasolabial aesthetics in cleft lip and palate (CLP) is a vital component of assessment of treatment outcome. It is usually performed based on two-dimensional (2D) facial photographs. An increasing use of three-dimensional (3D) imaging warrants an assessment if 3D images can substitute 2D photographs during aesthetic evaluation. The aim of this study was to compare reliability of rating nasolabial appearance on 3D images and standard 2D photographs in prepubertal children. Forty subjects (age: 8.8-12) with unilateral CLP treated according to a standardized protocol, who had 2D and 3D facial images were selected. Eight lay raters assessed nasal form, nasal deviation, vermilion border, and nasolabial profile on cropped 2D and 3D images using a 100-mm visual analogue scale (VAS). Additionally, raters answer two questions: 1. Do 2D or 3D images provide more information on nasolabial aesthetics? and 2. Is aesthetic evaluation easier on 2D or 3D images? Intrarater agreement demonstrated a better reliability of ratings performed on 3D images than 2D images (correlation coefficients for 3D images ranged from 0.733 to 0.857; for 2D images from 0.151 to 0.611). The mean scores showed, however, no difference between 2D and 3D formats (>0.05). 3D images were regarded more informative than 2D images (P = 0.001) but probably more difficult to evaluate (P = 0.06). Basal view of the nose was not assessed. 3D images seem better than 2D images for rating nasolabial aesthetics but raters should familiarize themselves with them prior to rating.

Although most research on human facial attractiveness has used front-facing two-dimensional (2D) images, our primary visual experience with faces is in three dimensions. Because face coding in the human visual system is viewpoint-specific, faces may be processed differently from different angles. Thus, results from perceptual studies using front-facing 2D facial images may not be generalizable to other viewpoints. We used rotating three-dimensional (3D) images of women's faces to test whether men's attractiveness ratings of women's faces from 2D and 3D images differed. We found a significant positive correlation between men's judgments of women's facial attractiveness from 2D and 3D images (r = 0.707), suggesting that attractiveness judgments from 2D images are valid and provide similar information about women's attractiveness as do 3D images. We also found that women's faces were rated significantly more attractive in 3D images than in 2D images. Our study verifies a novel method using 3D facial images, which may be important for future research on viewpoint-specific social perception. This method may also be valuable for the accurate measurement and assessment of facial characteristics such as averageness, identity, attractiveness, and emotional expression.

Three-dimensional imaging of acetabular dysplasia: diagnostic value and impact on surgical type classification

Three-dimensional (3D) imaging systems are being researched extensively for purposes of sensing and visualization in fields as diverse as defense, medical, art, and entertainment. When compared to traditional 2D imaging techniques, 3D imaging offers advantages in ranging, robustness to scene occlusion, and target recognition performance. Amongst the myriad 3D imaging techniques, 3D multiperspective imaging technologies have received recent attention due to the technologies’ relatively low cost, scalability, and passive sensing capabilities. Multiperspective 3D imagers collect 3D scene information by recording 2D intensity information from multiple perspectives, thus retaining both ray intensity and angle information. Three novel developments in 3D sensing, imaging, and visualization systems are presented: 3D imaging with axially distributed sensing, 3D optical profilometry, and occluded 3D object tracking.

To assess the perception of non-pregnant sonographers, sonologists and undergraduate students on the use of three-dimensional (3D) ultrasound technology in fetal medicine. This was a study of two groups of non-pregnant subjects. Group I included 520 (305 female, 215 male) medical professionals who completed a questionnaire after attending a lecture on 3D imaging. Factors such as gender, career and having children were analyzed with respect to the attendee's responses about use of 3D ultrasound for medical purposes and for reassurance. Group II included 137 (75 female, 60 male, two unknown) undergraduate students from bioengineering, psychology and physiology classes who completed a questionnaire after attending a brief presentation on two-dimensional and 3D fetal imaging. Factors such as gender and area of educational interest were analyzed with respect to the students' responses about the use of 3D ultrasound for medical purposes and for parental-fetal attachment. In Group I, 63% said that they would like to have a 3D ultrasound examination in the future, while 14% said that they would not. Common reasons given for wanting a 3D ultrasound exam in the future were for medical purposes (39%) or reassurance (18%). The main differences perceived between two-dimensional (2D) and 3D ultrasound were medical advantages (65%) and parental reassurance (28%). 62.4% of Group I thought 3D technology should be in wide use in obstetric ultrasound and 73.6% thought that 3D ultrasound would reassure parents carrying normal fetuses. Gender, age and career did not have a significant influence on perception of 3D ultrasound. In Group II, the majority (91%) said they could see a remarkable difference between 2D and 3D ultrasound. 83% responded that they would like to have a 3D ultrasound examination of their own baby in the future for the following reasons: 34% for the detailed picture, 31% for increased abnormality detection, 13% for reassurance or curiosity; 8% thought it would be unnecessary or a negative experience. Concerning parental-fetal attachment, 72% thought 3D ultrasound would have a positive effect. The majority of Group II (93%) thought 3D ultrasound would be valuable and 56% thought 3D ultrasound would assist in diagnosing fetal abnormalities. There was no significant relationship between gender, age or area of interest and the perception of 3D ultrasound. Responses by sonographers and physicians suggest that 3D ultrasound will have a role in the future for medical indications and in reassuring patients carrying normal fetuses. Our results also suggest that undergraduate students believe that 3D ultrasound will be a valuable technique in obstetrics and that it will have a positive effect on parental-fetal attachment.

Background: In the past, measurement of upper limb lymphedema was done by water displacement (WD), which is frequently cited as the gold standard. For various reasons, however, the use of WD is restricted in clinical settings. A more precise and easy-to-use method would be favorable. The high precision of three-dimensional (3D) imaging in comparison to WD has already been reported for healthy subjects. The aim of this study is to determine the validity and reliability of 3D imaging by comparing it to the WD method in women with unilateral upper limb lymphedema. Methods and Results: Thirty-nine women with unilateral breast cancer-related lymphedema (BCRL) were included, of which 37 completed two volume measurement techniques (3D and WD) on the BCRL and contralateral healthy arm. Slightly larger volumes were measured by the WD method in healthy arms (+9.8 mL; p = 0.058) and also in BCRL arms (+18.5 mL; p < 0.001). All measurements were performed twice by the same researcher to evaluate reliability. There was no significant difference between the two measurements for healthy arms (p = 0.323) or BCRL arms (p = 0.807) in 3D imaging. Bland-Altman plots showed a high limit of agreement between the single measurements. 3D imaging had a high intrarater reliability (Intraclass Correlation Coefficient = 0.999). Conclusion: Results show that 3D imaging is an innovative method for measuring upper limb volume in BCRL patients. Even though image processing is time consuming, 3D imaging combines high reproducibility with high precision. By software automation, this technique could easily be integrated into clinical routine. It is for this reason that we would recommend implementing the Vectra 3D imaging technique for measurement of BCRL.

Our objective was to investigate the long-term functional outcomes of robot-assisted partial nephrectomy (RAPN) combined with three-dimensional (3D) imaging. The 3D images, reconstructed using computed tomography, were introduced in RAPN procedures. The demographic, oncological, functional, and volumetric outcomes of 296 patients who underwent RAPN with and without 3D imaging between 2013 and 2021 were analyzed retrospectively. Propensity score matching (1:1) was performed to adjust for potential baseline confounders. After matching, 71 patients were allocated to each group. In the 3D RAPN (3DRPN) group, functional outcomes significantly improved: the number of patients with over 90% estimated glomerular filtration rate (eGFR) preservation rate (40 vs. 43, P = 0.044), eGFR preservation rate (88.0% vs. 91.6%, P = 0.006), the number of patients with chronic kidney disease (CKD) upstaging (26 vs. 13, P = 0.023), and split renal function preservation rate (operated kidney: 84.9% vs. 88.5%, P = 0.015). The 3DRPN group showed superiority in terms of >90% eGFR preservation (P = 0.010), CKD upstaging-free survival rates (P < 0.001), and volumetric outcomes (excess parenchymal volume: 27.9 vs. 17.7mL, P = 0.030; parenchyma volume preservation rate: 81.6% vs. 88.8%, P = 0.006). Three-dimensional imaging was positively associated with eGFR preservation (P = 0.023, odds ratio: 2.34) and prevention of CKD upstaging (P = 0.013, odds ratio: 2.90). In this study, RAPN combined with 3D imaging underscored the preservation of eGFR > 90% and the prevention of CKD upstaging by improving the preservation rate of renal parenchyma and split renal function.

Intricate resection and complex reconstructive procedures often required for primary and metastatic orbital tumors are facilitated by accurate imaging. A three-dimensional (3D) image can be reconstructed from source axial multidetector computed tomography (MDCT) images to visualize orbital tumors. To assess the utility of 3D images in this setting, the 3D images were reconstructed retrospectively for 20 patients with an orbital tumor and compared to two-dimensional (2D) orthogonal MDCT studies. Both types of images were assessed for their capacity to show the bony orbital walls and foramina, extraocular muscles, and optic nerve in the orbit contralateral to the tumor and, in the affected orbit, the extent of the tumor and its relationship to normal orbital contents and associated bone destruction. 3D imaging is most informative when axial images are acquired at 1.25 mm collimation. The optic nerve, extraocular muscles, and well-circumscribed orbital tumors were well visualized on 3D images. On 3D imaging, tumor-associated destruction of the lateral and superior orbital walls was fairly well demonstrated and that of the inferior and medial walls was not. The 3D images provide the surgeon with a comprehensive view of well-circumscribed orbital tumors and its relationship to extraocular muscles, exiting foramina, and the superior and lateral walls.

The term is often used to describe the performance of an imaging system. Recent research showed however that image quality may not be the most appropriate term to capture the evaluative processes associated with experiencing three-dimensional (3D) images. The added value of depth in 3D images is clearly recognized when viewers judge image quality of unimpaired 3D images against their two-dimensional (2D) counterparts. However, when viewers are asked to rate image quality of impaired 2D and 3D images, the image quality results for both 2D and 3D images are mainly determined by the introduced artifacts, and the addition of depth in the 3D images is hardly accounted for. In this article we describe an experiment where we applied and tested two alternative evaluative concepts: naturalness and viewing experience. It was hypothesized that these concepts would be more sensitive to the added value of depth in 3D images. Four scenes were used, varying in dimension (2D and 3D) and noise level (six levels of white Gaussian noise). Results showed that both viewing experience and naturalness were rated higher in 3D than in 2D when the same noise level was applied. Thus, the added value of depth is clearly demonstrated when the concepts of viewing experience and naturalness are being evaluated in contrast to earlier results found using image quality. The added value of 3D over 2D, expressed in noise level, was 2 dB for viewing experience and 4 dB for naturalness, indicating that naturalness appears the more sensitive evaluative concept for demonstrating the psychological impact of 3D displays.

Consider the scattering of a time-harmonic electromagnetic plane wave by an arbitrarily shaped and filled cavity embedded in a perfect electrically conducting infinite ground plane. A method of symmetric coupling of finite element and boundary integral equations is presented for the solutions of electromagnetic scattering in both transverse electric and magnetic polarization cases. Given the incident field, the direct problem is to determine the field distribution from the known shape of the cavity; while the inverse problem is to determine the shape of the cavity from the measurement of the field on an artificial boundary enclosing the cavity. In this paper, both the direct and inverse scattering problems are discussed based on a symmetric coupling method. Variational formulations for the direct scattering problem are presented, existence and uniqueness of weak solutions are studied, and the domain derivatives of the field with respect to the cavity shape are derived. Uniqueness and local stability results are established in terms of the inverse problem.

Blind 3D image quality assessment based on self-similarity of binocular features

To assess the value of three-dimensional (3D) image reconstructions of two-dimensional (2D) data from contiguous non-overlapping slices in the diagnosis of spinal trauma, 21 patients with a total of 36 injured vertebrae and 4 normal controls were examined. Forty plain films in two planes, 40 axial CT scans with multiplanar reformatted (MPR) 2D reconstructions and 40 sets of 3D images (surface rendering technique) were independently evaluated by four readers. The final diagnosis was defined after a panel review of clinical, surgical and imaging findings on all modalities. The 3D image reconstructions were not as accurate as axial CT with MPR 2D reconstructions in the diagnosis of vertebral body (n = 20) and posterior element fractures (n = 35). Dislocation (n = 3) was equally well detected by all imaging modalities. Narrowing of the spinal canal (n = 17) was best assessed by either MPR 2D CT or 3D images. A rotational component was diagnosed more accurately by 3D images, followed by 2D CT and plain films. Thus, 3D images combined with MPR 2D CT reconstructions are an important adjunct for an accurate diagnosis of spinal trauma, especially when a rotational component is suspected.

Optical three-dimensional (3D) molecular imaging is highly desirable for providing precise distribution of the target-of-interest in disease models. However, such 3D imaging is still far from wide applications in biomedical research; 3D brain optical molecular imaging, in particular, has rarely been reported. In this report, we designed chemiluminescence probes with high quantum yields, relatively long emission wavelengths, and high signal-to-noise ratios to fulfill the requirements for 3D brain imaging in vivo. With assistance from density-function theory (DFT) computation, we designed ADLumin-Xs by locking up the rotation of the double bond via fusing the furan ring to the phenyl ring. Our results showed that ADLumin-5 had a high quantum yield of chemiluminescence and could bind to amyloid beta (Aβ). Remarkably, ADLumin-5's radiance intensity in brain areas could reach 4 × 107 photon/s/cm2/sr, which is probably 100-fold higher than most chemiluminescence probes for in vivo imaging. Because of its strong emission, we demonstrated that ADLumin-5 could be used for in vivo 3D brain imaging in transgenic mouse models of Alzheimer's disease.

In this paper, a three-dimensional (3D) image security system combines the use of the smart pixel mapping (SPM)algorithm and the Fibonacci transformation technique is proposed. In order to reconstruct orthoscopic 3D images withimproved image quality, a smart pixel mapping process is adopted. Based on the SPM-based computational integralimaging (CII) system, the depth-converted elemental image array (EIA) is obtained for increasing the quality of thereconstructed image. In the encryption process, the depth-converted EIA is scrambled by the Fibonacci transformation(FT) algorithm. Meanwhile, the computational integral imaging reconstruction (CIIR) technique is used to reconstructthe 3D image in the image reconstruction process. Compared with conventional CII-based 3D image encryptionmethods, the proposed method enable us to reconstruct high-resolution orthoscopic 3D images at long distance. Todemonstrate the effectiveness of the proposed method, some numerical experiments are made to test the validity andthe capability of the proposed 3D image security system.

Simulators are being used to teach laparoscopic skills before residents get to the operating room. It is unknown whether the use of three-dimensional (3D) vision will facilitate laparoscopic training. Therefore, our objective was to compare the effectiveness of using 3D imaging over the traditional two-dimensional (2D) imaging to teach laparoscopic simulator skills to novice individuals and assess whether 3D imaging ameliorates laparoscopic performance for surgeons who have already adapted to working within a 2D surgical environment. This prospective study involved 36 surgical residents and students. Inexperienced participants included medical students and first- and second-year surgical residents (n = 25). Experienced participants included third- and fifth-year surgical residents (n = 11). Participants were tested on six laparoscopic skills using 2D or 3D imaging systems and then retested about 3 months later using the opposing imaging system. Evaluation of performance was based on the time elapsed to task completion and the errors committed during that time. The experienced participants performed better than the inexperienced participants regardless of the imaging system. Inexperienced participants initially tested using 2D imaging required significantly more time and/or made more errors to complete five of the six laparoscopic tasks compared to those initially tested using 3D imaging (p < 0.05). After initial testing on 3D imaging, inexperienced participants retested using 2D imaging performed significantly better on five of six tasks compared to the scores of inexperienced participants initially tested on 2D imaging (p < 0.05). In contrast, the inexperienced participants' retested on 3D after initial 2D imaging did not improve on any laparoscopic task compared to the scores of inexperienced participants initially tested on 3D imaging. Among the experienced participants, no significant difference in time or errors to task completion was observed under 2D imaging compared to 3D imaging during the first or second testing session. Our study indicates that 3D imaging offers significant advantages in the teaching of laparoscopic skills to inexperienced individuals.