Evaluation of the reproducibility of non-verbal facial expressions in normal persons using dynamic stereophotogrammetric system / 北京大学学报(医学版)

OBJECTIVE@#To assess the reproducibility of non-verbal facial expressions (smile lips closed, smile lips open, lip purse, cheek puff) in normal persons using dynamic three-dimensional (3D) imaging and provide reference data for future research.@*METHODS@#In this study, 15 adults (7 males and 8 females) without facial asymmetry and facial nerve dysfunction were recruited. Each participant was seated upright in front of the 3D imaging system in natural head position. The whole face could be captured in all six cameras. The dynamic 3D system captured 60 3D images per second. Four facial expressions were included: smile lips closed, smile lips open, lip purse, and cheek puff. Before starting, we instructed the subjects to make facial expressions to develop muscle memory. During recording, each facial expression took about 3 to 4 seconds. At least 1 week later, the procedure was repeated. The rest position (T0) was considered as the base frame. The first quartile of expressions (T1), just after reaching the maximum state of expressions (T2), just before the end of maximum state of expressions (T3), the third quartile of expressions (T4), and the end of motion (T5) were selected as key frames. Using the stable part of face such as forehead, each key frame (T1-T5) of the different expressions was aligned on the corresponding frame at rest (T0). The root mean square (RMS) between each key frame and its corresponding frame at rest were calculated. The Wilcoxon signed ranks test was applied to assess statistical differences between the corresponding frames of the different facial expressions.@*RESULTS@#Facial expressions like smile lips closed, smile lips open, and cheek puff were reproducible. Lip purse was not reproducible. The statistically significant differences were found on the T2 frame of the repeated lip purse movement.@*CONCLUSION@#The dynamic 3D imaging can be used to evaluate the reproducibility of facial expressions. Compared with the qualitative analysis and two-dimensions analysis, dynamic 3D images can be able to more truly represent the facial expressions which make the research more reliable.

Three Dimensional Measurement of Ideal Trajectory of Pedicle Screws of Subaxial Cervical Spine Using the Algorithm Could Be Applied for Robotic Screw Insertion

OBJECTIVE: To define optimal method that calculate the safe direction of cervical pedicle screw placement using computed tomography (CT) image based three dimensional (3D) cortical shell model of human cervical spine.METHODS: Cortical shell model of cervical spine from C3 to C6 was made after segmentation of in vivo CT image data of 44 volunteers. Three dimensional Cartesian coordinate of all points constituting surface of whole vertebra, bilateral pedicle and posterior wall were acquired. The ideal trajectory of pedicle screw insertion was defined as viewing direction at which the inner area of pedicle become largest when we see through the biconcave tubular pedicle. The ideal trajectory of 352 pedicles (eight pedicles for each of 44 subjects) were calculated using custom made program and were changed from global coordinate to local coordinate according to the three dimensional position of posterior wall of each vertebral body. The transverse and sagittal angle of trajectory were defined as the angle between ideal trajectory line and perpendicular line of posterior wall in the horizontal and sagittal plane. The averages and standard deviations of all measurements were calculated.RESULTS: The average transverse angles were 50.60º±6.22º at C3, 51.42º ±7.44º at C4, 47.79º ±7.61º at C5, and 41.24º ±7.76º at C6. The transverse angle becomes more steep from C3 to C6. The mean sagittal angles were 9.72º ±6.73º downward at C3, 5.09º±6.39º downward at C4, 0.08º ±6.06º downward at C5, and 1.67º ±6.06º upward at C6. The sagittal angle changes from caudad to cephalad from C3 to C6.CONCLUSION: The absolute values of transverse and sagittal angle in our study were not same but the trend of changes were similar to previous studies. Because we know 3D address of all points constituting cortical shell of cervical vertebrae. we can easily reconstruct 3D model and manage it freely using computer program. More creative measurement of morphological characteristics could be carried out than direct inspection of raw bone. Furthermore this concept of measurement could be used for the computing program of automated robotic screw insertion.

Three Dimensional Measurement of Ideal Trajectory of Pedicle Screws of Subaxial Cervical Spine Using the Algorithm Could Be Applied for Robotic Screw Insertion

OBJECTIVE: To define optimal method that calculate the safe direction of cervical pedicle screw placement using computed tomography (CT) image based three dimensional (3D) cortical shell model of human cervical spine. METHODS: Cortical shell model of cervical spine from C3 to C6 was made after segmentation of in vivo CT image data of 44 volunteers. Three dimensional Cartesian coordinate of all points constituting surface of whole vertebra, bilateral pedicle and posterior wall were acquired. The ideal trajectory of pedicle screw insertion was defined as viewing direction at which the inner area of pedicle become largest when we see through the biconcave tubular pedicle. The ideal trajectory of 352 pedicles (eight pedicles for each of 44 subjects) were calculated using custom made program and were changed from global coordinate to local coordinate according to the three dimensional position of posterior wall of each vertebral body. The transverse and sagittal angle of trajectory were defined as the angle between ideal trajectory line and perpendicular line of posterior wall in the horizontal and sagittal plane. The averages and standard deviations of all measurements were calculated. RESULTS: The average transverse angles were 50.60º±6.22º at C3, 51.42º ±7.44º at C4, 47.79º ±7.61º at C5, and 41.24º ±7.76º at C6. The transverse angle becomes more steep from C3 to C6. The mean sagittal angles were 9.72º ±6.73º downward at C3, 5.09º±6.39º downward at C4, 0.08º ±6.06º downward at C5, and 1.67º ±6.06º upward at C6. The sagittal angle changes from caudad to cephalad from C3 to C6. CONCLUSION: The absolute values of transverse and sagittal angle in our study were not same but the trend of changes were similar to previous studies. Because we know 3D address of all points constituting cortical shell of cervical vertebrae. we can easily reconstruct 3D model and manage it freely using computer program. More creative measurement of morphological characteristics could be carried out than direct inspection of raw bone. Furthermore this concept of measurement could be used for the computing program of automated robotic screw insertion.

Sex Determination Using Three-dimensional Image of Skull in Korean: Metric Study by Discriminant Function Analysis / 체질인류학회지

Sex determination is considered the first and most important process in the identification of unknown skeletal remains. The skull is one of bones with high accuracy to discriminate sexes, but there is no dimorphic studies of Korean skull by discriminant function analysis. The aim of this study was to build and provide an easy and accurate discriminant equation to sex determination by using three-dimensional skull images of Korean. Computed tomography images from 102 cadavers were reconstructed three-dimensional images by computer program. We measured 44 variables using the template in computer program and variables were sorted out items with high accuracy and reliability by intraclass correlation coefficient (ICC), Cohen's d value, and receiver operating characteristic (ROC) curve. The equation with the highest accuracy had 82.7% in males, 82.2% in females, it was constituted bizygomatic diameter, cranial base length, biauricular breadth, upper facial breadth, frontal chord, foramen magnum breadth, and right mastoid length. The cross-validated accuracy had 76.5%~86.7% using 3D skull images in Koreans. The value of variables that matches the other population group study, most of variables had a statistically significant difference among population groups. Male skulls in Koreans were smaller than those in European and female skulls were bigger than in Asian. This result should be helpful to determine sex in Koreans.

A primary research of intensity-modulated dose verification based on anatomic structure of three-dimensional images / 中华放射肿瘤学杂志

Objective To verify IMRT plans in point,planar and 3D dose,and to concretely analyze the dose differences of 3D anatomic structure based on Gamma passing rate.Methods Thimble ion-chamber,Matrixx and ArcCheck were separately used to measure six nasopharyngeal carcinoma treatment plans and six lung cancer treatment plans.The dose measurement deviation of the center point was compared as well as the Gamma passing rate of dose verification under the criteria of both 3％/3 mm and 2％/2 mm,the group t-test and one-way ANOVA were also proceeded.3DVH system was used to analyze the dose measurement deviation of target volume (TV) and organ at risk (OAR) through DVH.Results For IMRT and VMAT treatment plans,the mean deviation of point dose was (0.59 ± 1.31) ％ and (-1.00 ± 1.03)％ respectively,and the maximum deviation was less than 3％.Under the criterion of 3％/3 mm,the Gamma passing rate measured by Matrixx,ArcCheck and 3DVH for IMRT plans was 96.28％,97.55％ and 99.02％ respectively,and for VMAT plans,the corresponding results of three different detectors were 97.24％,99.67％ and 98.48％.The results analyzed and compared by 3DVH showed that even under the condition of high Gamma pass rate (more than 95％ for a Gamma criterion of 3％/3 mm),the DVH metrics of both TV and OAR in two cases (account for 16.7％ of the total plan) were significantly different on the clinical parameters,including GTV,spinal cord and brain stem etc.Conclusions The analysis of dose difference of the measurement results based on Gamma pass rate and on anatomic structure of 3D images can more effectively evaluate the influence of dose error to the implementing of clinical plan and the impact to the clinical treatment.

Anatomia microcirúrgica da artéria carótida externa: um estudo estereoscópico / Microsurgical anatomy of the external carotid artery: a stereoscopic study

CONTEXTO: O conhecimento das estruturas anatômicas da artéria carótida externa por meio do estudo estereoscópico pode determinar melhores resultados em microcirurgias da artéria carótida externa. OBJETIVO: Descrever as estruturas da artéria carótida externa sob a visão estereoscópica, identificando seus múltiplos aspectos. MÉTODOS: Doze regiões cervicais foram dissecadas, utilizando-se microscópico cirúrgico com 3 a 40x de aumento. As dissecções anatômicas foram documentadas utilizando-se a técnica para obtenção de imagens tridimensionais (3D), objetivando a produção de impressões estereoscópicas. RESULTADOS: O uso da técnica estereoscópica possibilitou a abordagem da circulação arterial extracraniana, sendo realizados estudos cirúrgicos do tipo combinado fossa posterior e fossa infratemporal, tornando as microcirurgias e os procedimentos neurocirúrgicos vasculares mais precisos. CONCLUSÃO: O uso das imagens obtidas pela técnica estereoscópica produziu um resultado mais assertivo em relação ao estudo da anatomia para a microcirurgia e procedimentos neurocirúrgicos, facilitando melhor aprendizado previamente à realização de procedimentos complexos em neurocirurgia.

BACKGROUND: The knowledge on the anatomical structures of the external carotid artery through the stereoscopic study may provide better results in microsurgical treatment of the external carotid artery. OBJECTIVE: To describe the structures of the external carotid artery under stereoscopic vision, identifying its multiple aspects. METHODS: Twelve cervical regions were dissected using a surgical microscope with 3 to 40x magnification. The anatomical dissections were documented using the technique to obtain three-dimensional images (3D), aiming at producing stereoscopic prints. RESULTS: The use of the stereoscopic technique enabled the stereoscopic approach to extracranial arterial circulation, and it was followed by a combined posterior fossa and infratemporal approach, making microvascular surgery and neurosurgical procedures more precise. CONCLUSION: The use of images obtained through the stereoscopic technique produced a more assertive result in relation to the anatomy study for microsurgical or neurosurgical procedures, facilitating a better learning before performing complex procedures in neurosurgery.

Three-dimensional scanning with dual-source computed tomography in patients with acute skeletal trauma

OBJECTIVE: The aim of this study was to compare the efficiency of multiplanar reformatted images and threedimensional images created after multidetector computed tomography examination in detecting acute posttraumatic osseous pathology of the skeletal system. METHOD: Between October 2006 and December 2008, 105 patients with a history of acute trauma were referred to our service. Patients were evaluated with multidetector computed tomography using multiplanary reconstructed images initially (R-I), and six months after this initial evaluation, three-dimensional images were assessed of each patient (R-II). Axial images were used for guiding as a reference Data obtained was recorded and graded according to importance levels of the pathologies. RESULTS: The R-II score was higher in the non-articular and highest in periartricular fractures of the extremities, and thoracic and pelvic cage injuries. For the spinal column, while R-I data was more significant In patients referred with polytrauma, R-II data, was more statistically significant, for short processing and adaptation time to acquiring immediate critical information. For all cases it was seen that three dimensional scans were more efficient in providing the orientation, within a short time. CONCLUSION: By dual source multidedector tomography systems trauma patients may be evaluated by multiplanary and three dimensionally reconstructed images. When used correctly, three dimensional imaging is advantageous and can help determine the exact nature and extension and also importance of osseous injuries.

Serially Sectioned Images of the Whole Body (Eighth Report: Segmentation of the Upper Limb's Structures) / 대한해부학회지

Whole body of a Korean male cadaver was serially milled to make sectioned images. Segmentation of various anatomical structures can expand the utilization of the sectioned images such as three-dimensional (3D) reconstruction of the structures of real human. Following previous outlining of lower limb's structures, we decided to make segmented images of upper limb's structures in detail. Ninety-one structures (a skin, 32 bones, 49 muscles, 6 arteries, and 3 nerves) in the left upper limb were segmented in 628 sectioned images. While doing this, we developed more efficient technique for segmentation. To draw the outlines of various structures more quickly, sectioned images were filtered first and then outlines were drawn by 'quick selection' tool and other tools on the Photoshop. Also, outlines were automatically generated by interpolation using Combustion software. We made coronal and sagittal segmented images, browsing software of the serially sectioned images, volume 3D images, and surface 3D images for verifying segmentation. These segmented and sectioned images of the upper limb are expected to help other researchers make 3D images and various software of upper limb and to have widespread applications in both medical learning and research.

Three Dimensional Automatic Surface Reconstruction Software / 대한의료정보학회지

OBJECTIVE: After drawing and stacking contour of structures, which are identifed in the serially sectioned images, three-dimensional (3D) images can be made by surface reconstruction. The 3D images can be selected and rotated in a real time. The purpose of this research is to compose software of automatic surface reconstruction for making 3D images. METHODS: Contours of 55 structures in the 613 magnetic resonance images of whole body were drawn to make segmented images. We composed automatic software for stacking contours of a structure, for converting the contours into polygons, and for connecting vertices of the neighboring polygons to fill gaps between polygons with triangular surfaces. The surface reconstruction software was excuted to make 3D images of 55 structures. RESULTS: Virtual dissection software, on which 3D images could be selected and rotated, was composed. CONCLUSION: For other research, this like program can be composed for automatic surface reconstruction; several kinds of commercial software can be used for manual or automatic surface reconstruction. Investigators might choose one of the methods in consideration of their only circumstances.

Serially Sectioned and Segmented Images of the Mouse for Learning Mouse Anatomy / 대한해부학회지

Mouse anatomy is fundamental knowledge for researchers who perform biomedical experiments with mice. The purpose of our research is to present the serially sectioned images and segmented images of the mouse to produce three-dimensional images of the mouse, which are helpful in learning mouse anatomy. Using a cryomacrotome, a couple of male and female mice were transversely serially sectioned at 0.5 mm intervals to make sectioned surfaces. The sectioned surfaces were digitalized to make serially sectioned images. In the serially sectioned images of the female mouse, 14 structures including skin and bones were semi-automatically segmented on Adobe Photoshop software to make segmented images. The serially sectioned images and segmented images were stacked to make sagittal and coronal images, which were used for verifying the serially sectioned images and segmented images. In this ongoing research, the segmented images of male mouse will be added. All serially sectioned images and segmented images of the mouse will be presented worldwide. These images are expected to be used by many researchers for making three-dimensional images and virtual dissection software of the mouse, which are helpful in comprehending the stereoscopic morphology of the mouse's structures.

Manufacture of the Serially Sectioned Images of the Whole Body (Fourth Report: Methods for Selection and Treatment of the Cadaver and for Scanning of the MRIs and CTs) / 대한해부학회지

Visible Human Project dataset made in the United States has some problems which were caused by the cadaver selection, cadaver treatment, MRI (magnetic resonance image) scanning, and CT (computerized tomograph) scanning. Therefore, in this study, we intended to make better serially sectioned images, namely Visible Korean Human, which overcome the problems of Visible Human Project dataset. The better serially sectioned images will be the basis of better three dimensional images of the whole body, which are helpful in medical education An appropriate Korean male cadaver was selected for this study. Without injecting fixative, the cadaver's posture and direction were adjusted and fixed in an immobilizing box. Horizontal MRIs and CTs of the cadaver's whole body were scanned at 1 mm intervals. In addition, coronal and sagittal MRIs and CTs as well as movies of the MRIs and CTs were made. Age of the selected cadaver was young (32 years old), body size was Korean average (height 1,640 mm, weight 55 kg), and pathological findings were few. 1,718 couples of corresponding MRIs and CTs, in which anatomical structures appear clearly (pixel size 1 mm), were acquired. 276 couples of coronal MRIs and CTs as well as 505 couples of sagittal MRIs and CTs were acquired. Movies of all MRIs and CTs were acquired as well. The serially sectioned images acquired in this study will be helpful either in studying MRIs and CTs by referring to corresponding anatomical images or in studying anatomy and medicine by reconstructing MRIs, CTs, and anatomical images into three dimensional images.

Manufacture of the Serially Sectioned Images of the Whole Body (Third Report: Methods for Manufacture of the Segmented Images, Coronal Segmented Images, and Sagittal Segmented Images) / 대한해부학회지

While three dimensional (3D) images of the whole body can be reconstructed by using the serially sectioned images, 3D image of each anatomical structure can be reconstructed by using the segmented images. In this research, outlines of skin, bones, liver, lungs, kidneys, urinary bladder, heart, and brain in the anatomical images were decided to segment, and luminal outlines of digestive tract, respiratory tract, and arteries were decided to segment too. On the Adobe Photoshop, selections were semiautomatically drawn along outlines of the anatomical structures and semiautomatically corrected using magnetic lasso tool. Successively, selections were manually corrected either using lasso tool or through work path. The selections were filled with colors to make segmented images. By stacking rows and columns of the segmented images, coronal and sagittal segmented images were made. The coronal and sagittal segmented images were observed to find incorrect segmented images, which were revised. 8,507 segmented images with 0.2 mm intervals, 3,040x2,008 resolution, 0.2 mm pixel size, and 8 bits color depth were achieved, so that file size of 1 segmented image and 8,507 segmented images was 5.8 Mbytes and 48.3 Gbytes, respectively. These segmented images will be the basis for the development of 3D images of the anatomical structures and software of virtual dissection and virtual endoscopy, which are helpful in studying anatomy and endoscopy.

Manufacture of the Serially Sectioned Images of the Whole Body (First Report: Methods for Embedding and Serial Sectioning) / 대한해부학회지

Serially sectioned images (MR, CT, and anatomical images) of the whole body are helpful in anatomy education because three dimensional images can be reconstructed with the serially sectioned images, and then the three dimensional images can be sectioned and rotated. To make the most important anatomical images of the serially sectioned images, the cadaver's whole body should be embedded, frozen, and serially sectioned to make sectioned surfaces. In this study, to make the sectioned surfaces better than the Visible Human Project dataset, the equipments and techniques have been developed as follows. First, the equipments (embedding box, freezer) and techniques for embedding and freezing of the cadaver's whole body have been developed. Second, the equipments (cryomacrotome) and techniques for serial sectioning of the embedding box at 0.2 mm intervals have been developed. By using these equipments and techniques, the sectioned surfaces with good quality could be made at 0.2 mm intervals. The anatomical images made of the sectioned surfaces will be the basis for making better three dimensional images which are more helpful in anatomy education.

Manufacture of the Serially Sectioned Images of the Whole Body (Second Report: Photographing and Processing of the Anatomical Images) / 대한해부학회지

Serially sectioned images (MR, CT, and anatomical images) of the whole body are helpful in anatomy education because three dimensional images can be reconstructed with the serially sectioned images, and then the three dimensional images can be sectioned and rotated. To make the most important anatomical images of serially sectioned images, sectioned surfaces should be inputted into the personal computer after serial sectioning of the cadaver's whole body. In this study, equipments (digital camera and strobes) and techniques for inputting the sectioned surfaces into the personal computer to make anatomical images and for processing the anatomical images have been developed. By using these equipments and techniques, the anatomical images with the actual feature of the sectioned surfaces, the right alignment, and the constant brightness could be made. These anatomical images will be the basis for making good three dimensional images which are helpful in anatomy education.