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1.
Petit Y Dansereau J Labelle H de Guise JA 《Medical & biological engineering & computing》1998,36(4):389-394
This study provides a biplanar radiographic reconstruction method of volumes of interest to evaluate the location, dimensions
and orientation of human facet joints. Visibility of facet anatomical landmarks and areas of interest was evaluated on digital
radiographs of 20 idiopathic scoliotic adolescents. Areas of interest have provided the most reliable evaluation of facet
joints on postero-anterior and lateral digital radiographs. Volumes of interest of a thoracic and lumbar spinal segment (T1
to L3) were computed using the proposed biplanar 3D reconstruction method and compared with serial tomographic reconstructed
models. Differences of 1.5±0.7 mm in 3D location and 1.8±1.2° in sagittal orientation of volumes of interest were observed
between both representations. This in vivo geometric information on human vertebral facet joints will help us to understand
their role in spinal disorders and will provide important data for personalised biomechanical simulations. 相似文献
2.
The radiographic photogrammetry is applied, for locating anatomical landmarks in space, from their two projected images. The
goal of this paper is to define a personalized geometric model of bones, based uniquely on photogrammetric reconstructions.
The personalized models of bones are obtained from two successive steps: their functional frameworks are first determined
experimentally, then, the 3D bone representation results from modeling techniques. Each bone functional framework is issued
from direct measurements upon two radiographic images. These images may be obtained using either perpendicular (spine and
sacrum) or oblique incidences (pelvis and lower limb). Frameworks link together their functional axes and punctual landmarks.
Each global bone volume is decomposed in several elementary components. Each volumic component is represented by simple geometric
shapes. Volumic shapes are articulated to the patient’s bone structure. The volumic personalization is obtained by best fitting
the geometric model projections to their real images, using adjustable articulations. Examples are presented to illustrating
the technique of personalization of bone volumes, directly issued from the treatment of only two radiographic images. The
chosen techniques for treating data are then discussed. The 3D representation of bones completes, for clinical users, the
information brought by radiographic images. 相似文献
3.
《Medical & biological engineering & computing》1999,37(1):445-450
During scoliosis instrumentation surgery, it is difficult for surgeons fully to track vertebral motion in 3D, because only
the posterior elements of the spine are exposed. Different intra-operative modelling approaches are evaluated using a registration
technique that matches intra-operative measurements with a 3D preoperative model of the spine. Two tracking systems (magnetic
digitiser and mechanical arm) and two pre-operative reconstruction techniques (multiplanar radiography and CT scan) are sequentially
combined to build four intra-operative models. Their accuracy is assessed by comparison with the pre-operative geometry. The
most minimally invasive approach (multiplanar radiographic reconstruction and magnetic digitiser) has an accuracy of 5.9 mm
in translation, and errors on vertebral rotations are 4.4o, 6.7o and 5.0o in the frontal, sagittal and transverse planes, respectively. With CT scan reconstruction, the accuracy is significantly
increased by about 2 mm in translation and as much as 4.5o for vertebral rotations in the sagittal plane. For the mechanical arm, the accuracy is increased by less than 1 mm in translation
and 1o for vertebral rotations. CT scan is the most accurate reconstruction technique, but its use for long spinal segments is generally
not allowed because of the high radiation exposure. Multiplanar radiographic reconstruction may be an alternative solution
for long spinal segments when great accuracy is not necessary. Considering the small increase in accuracy and its awkwardness,
the use of the mechanical arm may not be appropriate during surgical manoeuvres.
Department of Automated Production Engineering, école de Technologie Supérieure 1100 Notre-Dame West, Montréal, Québec, Canada,
H3C 1K3 相似文献
4.
Benjamin Groisser Ron Kimmel Guy Feldman Nimrod Rozen Alon Wolf 《Annals of biomedical engineering》2018,46(8):1206-1215
Spine shape can be reconstructed from stereoradiography, but often requires specialized infrastructure or fails to account for subject posture. In this paper a protocol is presented for stereo reconstructions that integrates surface recordings with radiography and naturally accounts for variations in patient posture. Low cost depth cameras are added to an existing radiographic system to capture patient pose. A statistical model of human body shape is learned from public datasets and registered to depth scans, providing 3D correspondence across images for stereo reconstruction of radiographic landmarks. A radiographic phantom was used to validate these methods in vitro with RMS 3D landmark reconstruction error of 2.0 mm. Surfaces were automatically and reliably registered, with SD 12 mm translation disparity and SD .5° rotation. The proposed method is suitable for 3D radiographic reconstructions and may be beneficial in compensating for involuntary patient motion. 相似文献
5.
Mitulescu A Semaan I De Guise JA Leborgne P Adamsbaum C Skalli W 《Medical & biological engineering & computing》2001,39(2):152-158
Several 3D reconstruction techniques deriving from stereoradiographic DLT have been presented during the last 15 years, but
these techniques have usually been limited in accuracy because of the small number of corresponding anatomical landmarks identified
on both radiographs. A new technique has recently been proposed to perform 3D reconstruction of the spine using not only the
stereo-corresponding anatomical landmarks (seen on both frontal and sagittal X-ray films) but also some non-stereo-corresponding
ones. This technique (called non-stereo-corresponding points or NSCP) has already been used for cervical dry vertebrae. In
the present study, we focus on the validation of this technique for lumbar vertebrae by comparing four techniques: direct
measurement, CT scan, 3D reconstruction by stereoradiography using a direct linear transformation (DLT) algorithm and the
NSCP technique. The accuracy of the NSCP technique was also evaluated on different vertebral regions. The global results show
mean errors of 1.1 mm and maximum of 7.8 mm with regard to direct measurements. These mean errors are close to those obtained
using 3D reconstructions from CT scan using 1 mm cuts. 相似文献
6.
7.
Anders Forsberg Joel Kullberg Ingrid Agartz Hkan Ahlstrm Lars Johansson Karin M. Henriksson 《Clinical anatomy (New York, N.Y.)》2009,22(4):456-462
The aim of this study was to develop a software program, called Landmarker, which would aid studies of complex anatomical morphometry by simplifying the manual identification of landmarks in 3D images. We also tested its precision on routine magnetic resonance imaging (MRI) scans. To understand human biological variation, there is a need to identify morphological characteristics from the exterior and the interior of human anatomy. MRI, as opposed to other radiographic methods (mainly based on X‐ray techniques), supplies good soft tissue contrast, which allows for more complex assessments than what bony landmarks can provide. Because automation of this assessment is highly demanding, one of the primary goals for the new software was to enable more rapid identification of landmark sets in 3D image data. Repeat acquisition of head MRIs having a resolution of 0.94 × 0.94 × 1.20 mm3 were performed on 10 volunteers. Intra‐ and interoperator, as well as interacquisition variations of manual identification of exterior, craniofacial interior, and brain landmarks were studied. The average distances between landmarks were <1.8 mm, <2.3 mm, and <2.0 mm in the intra‐ and interoperator, and interacquisition evaluations, respectively. This study presents new software for time efficient identification of complex craniofacial landmarks in 3D MRI. To the best of our knowledge, no evaluation of software for rapid landmark‐based analysis of complex anatomies from 3D MR data has yet been presented. This software may also be useful for studies in other anatomical regions and for other types of image data. Clin. Anat. 22:456–462, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
8.
Kadoury S Cheriet F Laporte C Labelle H 《Medical & biological engineering & computing》2007,45(6):591-602
This paper presents a three-dimensional (3D) reconstruction system of the human spine for the routine evaluation of musculoskeletal
pathologies like idiopathic scoliosis. The main objective of this 3D reconstruction system is to offer a versatile and robust
tool for the 3D analysis of spines in any healthcare centre with standard clinical setup using standard uncalibrated radiographic
images. The novel system uses a self-calibration algorithm and a weak-perspective method to reconstruct the 3D coordinates
of anatomical landmarks from bi-planar radiographic images of a patient’s trunk. Additionally, a small planar object of known
dimensions is proposed to warrant an accurately scaled model of the spine. In order to assess the validity of the 3D reconstructions
yielded by the proposed system, a clinical study using 60 pairs of digitized X-rays of adolescents was conducted. The subject
cohort in the study group was composed of 51 scoliotic and 9 non-scoliotic patients, with an average Cobb angle on the frontal
plane of 25°. For each case, a 3D reconstruction of the spine and pelvis was obtained with the previous system used at our
hospital (which requires a positioning apparatus and a calibration jacket), and with the proposed method. Results show that
3D reconstructions obtained with the new system using uncalibrated X-ray images yield geometrically accurate models with insignificant
differences for 2D and 3D clinical indexes commonly used in the evaluation of spinal deformities. This demonstrates the system
to be a viable and accurate tool for clinical studies and biomechanical analysis purposes, with the added advantage of versatility
to any clinical setup for routine follow-ups and surgical planning.
This paper was supported in part by the National Sciences and Engineering Research Council of Canada (NSERC) and the Fonds
Quebecois de la Recherche sur la Nature et les Technologies (FQRNT). 相似文献
9.
Dumas R Blanchard B Carlier R de Loubresse CG Le Huec JC Marty C Moinard M Vital JM 《Medical & biological engineering & computing》2008,46(1):85-92
The 3D reconstruction of the spine in upright posture can be obtained by bi-planar radiographic methods, developed since the
1970s. The principle is to identify 4–25 anatomical landmarks per vertebrae and per images. This identification time is hardly
manageable in clinical practice. A semi-automated method is used: 3D standard vertebral models are positioned along with a
3D curve (identified all the way through the vertebral bodies). The silhouettes of the models of C7 and L5 vertebrae are first
adjusted and the positions of the other vertebrae are interpolated and optimised. The inter- and intra-operator variabilities
and the errors between the semi-automated method and the manual identification of six anatomical landmarks per vertebra are
evaluated on 20 pairs of X-ray images of subjects with different spinal deformities. The identification time for the semi-automated
method is 5 min. For scolitic subjects, the precision is under 2.2° and the accuracy is under 3.2° for all lateral, sagittal
and axial rotations. 相似文献
10.
Xavier Ohl Claire Stanchina Fabien Billuart Wafa Skalli 《Surgical and radiologic anatomy : SRA》2010,32(2):153-158
Purpose
To investigate the reproducibility of shoulder bony landmarks location using the EOS® low-dose stereoradiography system, in order to validate this new tool for the study of gleno-humeral pseudo-kinematics.Methods
An inter and intraobserver reproducibility study of shoulder bony landmarks location concerning 22 healthy volunteers. This study concerned the neutral position, arm at rest. Humerus and scapula were modeled with simple geometric shapes using specific software. Those shapes were positioned on A-P and lateral x-rays views. Images analysis of the 22 subjects was carried out three times (n r = 3), by two observers (n o = 2), for a total of n tot = 132 analyses.Results
We obtained a very good reproducibility for the humeral head center and the diaphysis axis with 95% confidence interval (IC95%) inferior to 1.09 mm and 0.41°, respectively. The uncertainty was higher for the lateral and medial epicondyles. Regarding the scapular bony landmarks, we observed a good reproducibility for the tip of the coracoid process, the inferior glenoid rim, and the axillar border with a 95% confidence interval lower than 2.13, 2.91 mm, and 3.67°, respectively. The uncertainty was higher for the most postero-lateral point of the acromion and the superior glenoid rim.Conclusion
Our analysis of the x-rays obtained with the EOS® low-dose stereoradiography system assessed the location reliability and reproducibility of specific scapular and humeral bony landmarks. This work opens the way to gleno-humeral pseudo-kinematics analysis using EOS® imaging system. 相似文献11.
In three-dimensional reconstruction of the human spine obtained from stereoradiographic setpus (two radiographs or more),
it is extremely difficult to identify exactly the same landmarks on all radiographs. The effect of these identification errors
was investigated with simulations made on points of known three-dimensional co-ordinates and compared with three-dimensional
reconstructions of real spines obtained with the direct linear transformation algorithm. Results showed that radiographic
identification errors of up to 2 mm were common, causing reconstruction errors of up to 5mm. These reconstruction errors may
be noticed in the form of geometrical inaccuracies in the graphical representation of three-dimensional reconstructions of
the spine. Successive displacements were then imposed on image point co-ordinates to minimise the identification error and
increase the reconstruction accuracy. The improvement on the three-dimensional reconstruction results was negligible. Three-dimensional
reconstructions obtained from three radiographs were also investigated. They showed slightly more accurate reconstructions
than those obtained from two radiographs. However, the increase of X-ray exposure on the patient may not be worthwhile. 相似文献
12.
Anthony Viste Franck Trouillet Rodolphe Testa Laurence Chèze Romain Desmarchelier Michel-Henri Fessy 《Surgical and radiologic anatomy : SRA》2014,36(3):259-263
Purpose
The aim of this preliminary study was to determine the accuracy of CT-scan to locate the femoral head centre.Methods
Eleven dried femurs were included for study. Three techniques were compared to determine femoral head centre (FHC) location: CT-scan, Motion Analysis and Faro-Arm. Markers were stuck on each femur to create a system of coordinates. Femurs lied on their posterior parts (bicondylar plane). Several points around the femoral head were palpated (Motion Analysis and Faro-Arm) or determined (Amira software for CT-scans). By a least-square regression method, the FHC location in 3D was defined for each technique.Results
The results of the FHC location determined by the CT-scan technique were compared with those measured by the faro-arm and the Motion Analysis techniques. The coordinates (X, Y, Z) of the FHC were compared between the three methods, and no statistical difference was found (p = 0.99). In a 3D plot, this gave a mean difference of 1.3 mm. The mean radius of the femoral head was of 22.5 mm (p = 0.6).Conclusions
CT-scan is as accurate and reliable as gold-standard techniques (motion and faro-arm). Locating FHC before and after hip arthroplasty would allow hip surgeons to determine and compare 3D orientation of the upper-end of femur: offset, height and anteversion. 相似文献13.
This study aims to establish a normal database of carpal postero-anterior radiographic measurements that might be a useful alternative to lateral film measurements in clinical practice. Selected landmarks were digitised on 80 postero-anterior wrist radiographs of asymptomatic volunteers. Carpal bone dimensions, ulnar variance, carpal height ratios, radial slope and various carpal angles were computed. Moreover, we describe two new parameters, the scapho-lunate ratios, that may prove useful in the diagnosis of carpal instability. Average values for carpal height, length of metacarpal III, capitate length, ulnar variance, radial slope and classical and revised carpal height ratios agreed with previous findings. Scaphoid length averaged 22 ± 3 mm, lunate anterior and posterior horn lengths 11 ± 1 mm and 16 ± 2 mm respectively. Except for carpal height and length of metacarpal III, standard deviations did not exceed 3 mm. Some of the variation coefficients reached 30% of the average dimension, so that variations, compared to means were not negligible. The standard deviations of angular measurements ranged from 3° to 13°. Further investigations are needed to confirm the usefulness of scapho-lunate ratios. 相似文献
14.
Killeen MJ Thomas G Gurung IS Goddard CA Fraser JA Mahaut-Smith MP Colledge WH Grace AA Huang CL 《Acta physiologica (Oxford, England)》2007,189(1):33-46
Aim: Hypokalaemia is associated with a lethal form of ventricular tachycardia (VT), torsade de pointes, through pathophysiological mechanisms requiring clarification. Methods: Left ventricular endocardial and epicardial monophasic action potentials were compared in isolated mouse hearts paced from the right ventricular epicardium perfused with hypokalaemic (3 and 4 mm [K+]o) solutions. Corresponding K+ currents were compared in whole‐cell patch‐clamped epicardial and endocardial myocytes. Results: Hypokalaemia prolonged epicardial action potential durations (APD) from mean APD90s of 37.2 ± 1.7 ms (n = 7) to 58.4 ± 4.1 ms (n =7) and 66.7 ± 2.1 ms (n = 11) at 5.2, 4 and 3 mm [K+]o respectively. Endocardial APD90s correspondingly increased from 51.6 ± 1.9 ms (n = 7) to 62.8 ± 2.8 ms (n = 7) and 62.9 ± 5.9 ms (n = 11) giving reductions in endocardial–epicardial differences, ΔAPD90, from 14.4 ± 2.6 to 4.4 ± 5.0 and ?3.4 ± 6.0 ms respectively. Early afterdepolarizations (EADs) occurred in epicardia in three of seven spontaneously beating hearts at 4 mm [K+]o with triggered beats followed by episodes of non‐sustained VT in nine of 11 preparations at 3 mm . Programmed electrical stimulation never induced arrhythmic events in preparations perfused with normokalemic solutions yet induced VT in two of seven and nine of 11 preparations at 4 and 3 mm [K+]o respectively. Early outward K+ current correspondingly fell from 73.46 ± 8.45 to 61.16±6.14 pA/pF in isolated epicardial but not endocardial myocytes (n = 9) (3 mm [K+]o). Conclusions: Hypokalaemic mouse hearts recapitulate the clinical arrhythmogenic phenotype, demonstrating EADs and triggered beats that might initiate VT on the one hand and reduced transmural dispersion of repolarization reflected in ΔAPD90 suggesting arrhythmogenic substrate on the other. 相似文献
15.
Approach for the smoothing of three-dimensional reconstructions of the human spine using dual Kriging interpolation 总被引:1,自引:1,他引:0
In numerous situations, 3-D reconstructions of the spine are represented as curves in space, with the vertebral centroids
as control points. Interpolation functions such as splines, polynomials or Fourier series have been used to minimise measurement
errors and to perform specific calculations. A more general approach, dual Kriging, is presented which incorporates in a single
formulation several methods, such as piece-wise linear interpolation, splines and least square functions as a limit case.
To minimise user interaction and to control the different Kriging parameters, a computer program is developed allowing efficient
use of these interpolation techniques in a clinical environment. Given different drift and covariance functions, the program
determines the most suitable Kriging model for specific spine geometries and controls the amount of smoothing performed on
raw data. Validation of the technique is with analytical 3-D curves, where random noise is added to represent reconstruction
errors. A maximum absolute mean difference of 1·85±0·50 mm is found between the analytical and noisy curves smoothed with
the Kriging technique for 200 points. Results obtained on actual 3-D reconstructions of scoliotic patients are very promising. 相似文献
16.
Phillip A. Barksdale Scott P. Brody Alan D. Garely Thomas E. Elkins Thomas E. Nolan Raymond F. Gasser 《Clinical anatomy (New York, N.Y.)》1997,10(5):324-327
Our purpose was to delineate the course of the ureter in the female pelvis in relationship to several important surgical landmarks. Ten female cadavers with undissected pelves were used. The ureter was identified at the pelvic brim and traced inferiorly to the bladder. Sets of measurements (±0.1 cm) that help define the location of the ureter were obtained at the three landmarks; the ischial spine, the obturator canal and the insertion of the arcus tendineus on the pubic bone. The mean distances from the ureter to the pelvic floor were ischial spine, 3.2 ± 0.1 cm; obturator canal, 3.2 ± 0.1 cm; and the insertion of the arcus tendineus on the pubic bone, 1.6 ± 0.1 cm. The mean distances from the arcus tendineus to the pelvic floor were ischial spine, 1.9 ± 0.1 cm; obturator canal, 2.8 ± 0.1 cm; and the insertion of the arcus tendineus on the pubic bone, 3.2 ± 0.1 cm. This study defines the relationship of the ureter to the pelvic floor through measurements taken at three landmarks. The data should be useful to pelvic surgeons and are important for the development of future surgical techniques. Clin. Anat. 10:324–327, 1997. © 1997 Wiley-Liss, Inc. 相似文献
17.
《Medical engineering & physics》2016,38(2):187-191
Measurements between anatomical landmarks on radiographs are useful for diagnosis and treatment planning in the orthopedic field. Direct measurement on single radiographic images, however, does not truly reflect spatial relationships, as depth information is lost. We used stereo images from a slot scanning X-ray machine to estimate coordinates of three-dimensional (3D) bony landmarks for femoral neck anteversion (FNA) measurement. A set of 7 landmarks consisting of the centre of the femoral head; the centre of the base of the femoral neck; the medial and lateral condyles; the medial and lateral posterior condyles; and finally the centre of the knee; were found to be identifiable and suitable for radiographic measurement. The reconstructed 3D coordinates were then used to define the 3D geometry of the anatomical axes required to estimate FNA. Stereophotogrammetric measurements on a sample of 30 dry right adult femurs were compared to reference values obtained using the Kingsley Olmstead method applied to photographic images. A strong positive correlation (0.998) was found and the mean ± standard deviation of the stereophotogrammetric approach (13.08 ± 6.87)° was comparable to that of the Kingsley Olmstead method (13.14 ± 6.88)°. Intra- and inter-observer reliability were high, with the lower bound of the 95% confidence interval above 0.98 for the intra-class correlation coefficient. The results merit further validation against three dimensional imaging technology such as computed tomography, to confirm stereophotogrammetry as a suitable alternative for FNA measurement. 相似文献
18.
Scoliosis is a 3D deformity of the spine and rib cage. Extensive validation of 3D reconstruction methods of the spine from biplanar radiography has already been published. In this article, we propose a novel method to reconstruct the rib cage, using the same biplanar views as for the 3D reconstruction of the spine, to allow clinical assessment of whole trunk deformities. This technique uses a semi-automatic segmentation of the ribs in the postero-anterior X-ray view and an interactive segmentation of partial rib edges in the lateral view. The rib midlines are automatically extracted in 2D and reconstructed in 3D using the epipolar geometry. For the ribs not visible in the lateral view, the method predicts their 3D shape. The accuracy of the proposed method has been assessed using data obtained from a synthetic bone model as a gold standard and has also been evaluated using data of real patients with scoliotic deformities. Results show that the reconstructed ribs enable a reliable evaluation of the rib axial rotation, which will allow a 3D clinical assessment of the spine and rib cage deformities. 相似文献
19.
Se Hwan Hwang Sung Won Kim Chan Soon Park Soo Whan Kim Jin Hee Cho Jun Myung Kang 《Surgical and radiologic anatomy : SRA》2013,35(7):565-571
Purpose
This study aimed to investigate the anatomy of the infraorbital foramen (IOF), infraorbital canal (IOC), and infraorbital groove (IOG) with regard to surgical and invasive procedures using three-dimensional reconstruction of CT scans.Methods
The CT scans of 100 patients were evaluated retrospectively. The morphology of the IOF, IOC, and IOG as well as their relationships to different anatomic landmarks was assessed in a three-dimensional model.Results
The mean length of the IOC and IOG and the angle of the IOC relative to IOG were 11.7 ± 1.9, 16.7 ± 2.4 mm, and 145.5° ± 8.5°, respectively. The mean angles of the IOC relative to vertical and horizontal planes were 13.2° ± 6.4° and 46.7° ± 7.6°, respectively. In the relationships between the IOF and different anatomic landmarks, the mean distances from the IOF to supraorbital notch/foramen, facial midline, and infraorbital rim were 5.6 ± 3.1 mm laterally, 26.5 ± 1.9 mm laterally, and 9.6 ± 1.7 mm inferiorly, respectively. The mean distance from the IOF to anterior nasal spine (ANS) was 35.0 ± 2.6 mm, and the mean angle of the axis that passed the IOF and ANS relative to horizontal plane was 28.8° ± 4.1°. In addition, the mean soft tissue thickness overlying the IOF was 11.4 ± 1.9 mm.Conclusions
These results provide detailed knowledge of the anatomical characteristics and clinical importance of the IOF. Such knowledge is of paramount importance for surgeons when performing maxillofacial surgery and regional block anesthesia. 相似文献20.
Scolioses are pathologies changing the three-dimensional shape of spines. Numerous biomechanical studies reconstructed spines, from photogrammetric radiography. Each vertebra is represented by several landmarks, of which frontal and sagittal projections are recorded on the digitised film. These reconstructions, involving a great number of points, are accurate, but are time consuming. They describe evolving pathologies but the technique requires a specific radiographic protocol. A new approach has been studied in order to decrease time needed recording and treating data and delivering accurately parameters used clinically. It is applied to frontal deformations due to scoliosis. One numerical radiographic image is only needed. Three-dimensional spine is considered as a continuous beam of which frontal projection is bounded by two continuous curves. A small number of points, from 6 to 9, are recorded representing bounds. A continuous curve (B-spline) is constrained to pass through the recorded landmarks. Interactive software allows experimenter to adapt the global continuous bounding curve to the real projection by acting on local records. A mean curve representing the beam frontal projection is drawn. This mean curve is segmented in regions showing homogeneous concavities. Parameters describing the shape and angular tilting of each region are proposed for clinical applications. Vertebral bodies are located along the mean spinal curve. Analogous techniques are applied estimating axial rotation of vertebrae about the mean line of spine. The new approach is displayed using radiographic files of scoliotic patients. The new technique will be extended to the sagittal view with the goal of three-dimensional reconstructions. 相似文献