Systems analysis of X-ray films of the vertebral column

The systems analysis of spinal X-ray films (SASXF) developed by the author solves the problem of an integral and, concurrently, detailed study of the spine of a patient on the basis of routine X-ray study. The examination of the patient gave rise to a patient's systems spinal model that considers the individual features of the vertebral column, which are most significant for a manual therapist's work. The standards of a X-ray study, a protocol form, and examination tools are described. An example of systems spinal model is given. The experience accumulated during studies of more than 2000 patients has shown that this procedure is highly effective in implementing medical manipulations by the methods of manual therapy.     

Imaging of blocks in the spine with bone scintigraphy (SPECT)]

INTRODUCTION: One of the most important tasks of manual therapists is the treatment of hypomobile intervertebral joints. Such conditions of the spine are treated with various manipulations or mobilisation. The pathophysiological basis of hypomobility is still under discussion. Objective criteria for the diagnosis of impaired spinal mobility are not available. Nor is any substrate detectable by X-ray, computed tomography or NMR. AIM: To find evidence of a biomechanical alteration of hypomobile intervertebral joints with the aid of SPECT (Single Photon Emission Computed Tomography). STUDY DESIGN: 13 outpatients with back pain but otherwise healthy attending the Orthopaedic University Hospital in Marburg were examined by manual medical means, and were found to have hypomobility of an intervertebral joint. In addition, the spines of these patients were examined with SPECT (bone scanning). RESULTS: Comparison of the results of physical examination and bone scanning revealed that in 75% of all the cases the location (spinal segment) of the hypomobility identified by each of the two methods was identical. In 83%, they were in agreement on which of the sides (facet joint) was affected.     

Spinal Cord Segmentation by One Dimensional Normalized Template Matching: A Novel,Quantitative Technique to Analyze Advanced Magnetic Resonance Imaging Data

Spinal cord segmentation is a developing area of research intended to aid the processing and interpretation of advanced magnetic resonance imaging (MRI). For example, high resolution three-dimensional volumes can be segmented to provide a measurement of spinal cord atrophy. Spinal cord segmentation is difficult due to the variety of MRI contrasts and the variation in human anatomy. In this study we propose a new method of spinal cord segmentation based on one-dimensional template matching and provide several metrics that can be used to compare with other segmentation methods. A set of ground-truth data from 10 subjects was manually-segmented by two different raters. These ground truth data formed the basis of the segmentation algorithm. A user was required to manually initialize the spinal cord center-line on new images, taking less than one minute. Template matching was used to segment the new cord and a refined center line was calculated based on multiple centroids within the segmentation. Arc distances down the spinal cord and cross-sectional areas were calculated. Inter-rater validation was performed by comparing two manual raters (n = 10). Semi-automatic validation was performed by comparing the two manual raters to the semi-automatic method (n = 10). Comparing the semi-automatic method to one of the raters yielded a Dice coefficient of 0.91 +/- 0.02 for ten subjects, a mean distance between spinal cord center lines of 0.32 +/- 0.08 mm, and a Hausdorff distance of 1.82 +/- 0.33 mm. The absolute variation in cross-sectional area was comparable for the semi-automatic method versus manual segmentation when compared to inter-rater manual segmentation. The results demonstrate that this novel segmentation method performs as well as a manual rater for most segmentation metrics. It offers a new approach to study spinal cord disease and to quantitatively track changes within the spinal cord in an individual case and across cohorts of subjects.     

Effects of fluid structure interaction in a three dimensional model of the spinal subarachnoid space

It is unknown whether spinal cord motion has a significant effect on cerebrospinal fluid (CSF) pressure and therefore the importance of including fluid structure interaction (FSI) in computational fluid dynamics models (CFD) of the spinal subarachnoid space (SAS) is unclear. This study aims to determine the effects of FSI on CSF pressure and spinal cord motion in a normal and in a stenosis model of the SAS. A three-dimensional patient specific model of the SAS and spinal cord were constructed from MR anatomical images and CSF flow rate measurements obtained from a healthy human being. The area of SAS at spinal level T4 was constricted by 20% to represent the stenosis model. FSI simulations in both models were performed by running ANSYS CFX and ANSYS Mechanical in tandem. Results from this study show that the effect of FSI on CSF pressure is only about 1% in both the normal and stenosis models and therefore show that FSI has a negligible effect on CSF pressure.     

The Lipid Composition of Urodele Myelin Which Lacks Hydroxycerebroside and Hydroxysulfatide

The concentrations of cerebrosides and sulfatides were measured in the nervous systems of urodeles and related orders with a high performance liquid chromatographic technique. The peripheral and central nervous systems of all three urodele species, Necturus maculosis (mud puppy, a salamander), Notophthalmus viridescens (eastern red spot newt), and Desmognathus ochropheus (mountain salamander), were found to be completely devoid of alpha-hydroxy fatty acid-containing cerebrosides and sulfatides. All species of reptiles and fish classes close to urodeles contain these galactolipids. The levels of nonhydroxy fatty acid-containing cerebrosides and sulfatides are essentially similar in both urodeles and reptiles. Myelin isolated from Necturus spinal cord had a specific density of 1.07, lighter than mammalian myelin. Except for the absence of hydroxycerebrosides and hydroxysulfatides, the lipid composition of Necturus spinal cord myelin is essentially similar to that of frog and rat myelin. The fatty acids of nonhydroxycerebrosides are rich in monounsaturated homologs of C22-C25, and the sphingoid base consists of both sphinganine and sphingosine. Electron microscopic examination of the sciatic nerve showed that the general structure and interlamellar distances of salamander and newt myelin are identical to those of frog, chameleon, and rat. Necturus myelin, therefore, can be used as a model for the study of the functional and structural role of hydroxygalactolipids.     

Patient-specific finite element model of the spine and spinal cord to assess the neurological impact of scoliosis correction: preliminary application on two cases with and without intraoperative neurological complications

Scoliosis is a 3D deformation of the spine and rib cage. For severe cases, surgery with spine instrumentation is required to restore a balanced spine curvature. This surgical procedure may represent a neurological risk for the patient, especially during corrective maneuvers. This study aimed to computationally simulate the surgical instrumentation maneuvers on a patient-specific biomechanical model of the spine and spinal cord to assess and predict potential damage to the spinal cord and spinal nerves. A detailed finite element model (FEM) of the spine and spinal cord of a healthy subject was used as reference geometry. The FEM was personalized to the geometry of the patient using a 3D biplanar radiographic reconstruction technique and 3D dual kriging. Step by step surgical instrumentation maneuvers were simulated in order to assess the neurological risk associated to each maneuver. The surgical simulation methodology implemented was divided into two parts. First, a global multi-body simulation was used to extract the 3D displacement of six vertebral landmarks, which were then introduced as boundary conditions into the personalized FEM in order to reproduce the surgical procedure. The results of the FEM simulation for two cases were compared to published values on spinal cord neurological functional threshold. The efficiency of the reported method was checked considering one patient with neurological complications detected during surgery and one control patient. This comparison study showed that the patient-specific hybrid model reproduced successfully the biomechanics of neurological injury during scoliosis correction maneuvers.     

Monkey models of recovery of voluntary hand movement after spinal cord and dorsal root injury

The hand is unique to the primate and manual dexterity is at its finest in the human (Napier 1980), so it is not surprising that cervical spinal injuries that even partially block sensorimotor innervation of the hand are frequently debilitating (Anderson 2004). Despite the clinical need to understand the neuronal bases of hand function recovery after spinal and/or nerve injuries, relatively few groups have systematically related subtle changes in voluntary hand use following injury to neuronal mechanisms in the monkey. Human and macaque hand anatomy and function are strikingly similar, which makes the macaque the favored nonhuman primate model for the study of postinjury dexterity. In this review of monkey models of cervical spinal injury that have successfully related voluntary hand use to neuronal responses during the early postinjury months, the focus is on the dorsal rhizotomy (or dorsal rootlet lesion) model developed and used in our laboratory over the last several years. The review also describes macaque monkey models of injuries to the more central cervical spine (e.g., hemisection, dorsal column) that illustrate methods to assess postlesion hand function and that relate it to neurophysiological and neuroanatomical changes. Such models are particularly important for understanding what the sensorimotor pathways are capable of, and for assessing the outcome of therapeutic interventions as they are developed.     

The Phenix software for automated determination of macromolecular structures

X-ray crystallography is a critical tool in the study of biological systems. It is able to provide information that has been a prerequisite to understanding the fundamentals of life. It is also a method that is central to the development of new therapeutics for human disease. Significant time and effort are required to determine and optimize many macromolecular structures because of the need for manual interpretation of complex numerical data, often using many different software packages, and the repeated use of interactive three-dimensional graphics. The Phenix software package has been developed to provide a comprehensive system for macromolecular crystallographic structure solution with an emphasis on automation. This has required the development of new algorithms that minimize or eliminate subjective input in favor of built-in expert-systems knowledge, the automation of procedures that are traditionally performed by hand, and the development of a computational framework that allows a tight integration between the algorithms. The application of automated methods is particularly appropriate in the field of structural proteomics, where high throughput is desired. Features in Phenix for the automation of experimental phasing with subsequent model building, molecular replacement, structure refinement and validation are described and examples given of running Phenix from both the command line and graphical user interface.     

Use of pattern recognition technology for determination of the human differential leukocyte count

The imprecision, inaccuracy, and clinical sensitivity of an automated differential counter based on pattern recognition technology (HEMATRAK model 590) were evaluated using the NCCLS standard H20-T. The data show that the instrument is capable of performing assays in a manner comparable with the reference method proposed by NCCLS. In addition, data are presented from a multicenter study involving 174 HEMATRAK instruments which showed that the automated systems produce results equivalent to manual procedures (based on approximately 350 individual assays).     

Precision measurements of the RSA method using a phantom model of hip prosthesis

Radiostereometric analysis (RSA) has become one of the recommended techniques for pre-market evaluation of new joint implant designs. In this study we evaluated the effect of repositioning of X-ray tubes and phantom model on the precision of the RSA method. In precision measurements, we utilized mean error of rigid body fitting (ME) values as an internal control for examinations. ME value characterizes relative motion among the markers within each rigid body and is conventionally used to detect loosening of a bone marker. Three experiments, each consisting of 10 double examinations, were performed. In the first experiment, the X-ray tubes and the phantom model were not repositioned between one double examination. In experiments two and three, the X-ray tubes were repositioned between one double examination. In addition, the position of the phantom model was changed in experiment three. Results showed that significant differences could be found in 2 of 12 comparisons when evaluating the translation and rotation of the prosthetic components. Repositioning procedures increased ME values mimicking deformation of rigid body segments. Thus, ME value seemed to be a more sensitive parameter than migration values in this study design. These results confirmed the importance of standardized radiographic technique and accurate patient positioning for RSA measurements. Standardization and calibration procedures should be performed with phantom models in order to avoid unnecessary radiation dose of the patients. The present model gives the means to establish and to follow the intra-laboratory precision of the RSA method. The model is easily applicable in any research unit and allows the comparison of the precision values in different laboratories of multi-center trials.     

Patient dose levels for seven different radiographic examination types

This study was carried out as a part of a comprehensive project to establish a national diagnostic reference level (NDRL), for the first time, in Saudi Arabia. Seven of the most common X-ray examinations (10 projections) were included. This study consisted of 200 patients who were referred for X-ray examinations at King Khalid University Hospital (KKUH). The selected X-ray examinations were skull (PA), kub (AP and LAT), ankle (AP and LAT), foot (AP/OBL and LAT/OBL), hib (AP and LAT) and sinuses paranasal (AP). Mean patient information and exposure parameters for these seven radiographic examinations were recorded at KKUH. Some of these radiographic examinations were compared with their corresponding values at other national places [Security Forces Hospital (SFH); King Abdulaziz City for Science and Technology (KACST)] in Saudi Arabia. We found that the patient mean dose values recorded at KKUH were varied from those recorded at other national places. Wide variations in patient dose arising from a specific type of X-ray examination at different national places suggests that significant reductions in patient dose would be possible without affecting image quality. Furthermore, variations in patient dose may emerge from the examination technique, clinical condition, radiologist skill, tube current, tube potential and focus to film distance. The data of this study will be useful for the formulation of NDRLs, and it is also provides local diagnostic reference levels for some diagnostic X-ray examinations at KKUH and other national places in Saudi Arabia.     

Survival and Growth of Tree Species under Two Direct Seedling Planting Systems

Direct tree planting restoration systems are frequently used for recovering degraded tropical landscapes. Although manual planting tends to be more viable economically and logistically over small areas, in large restorations the use of agricultural equipment that optimizes effort is preferable. The aim of this study was to investigate the efficiency of the two native tree species planting systems—manual and mechanized—used in the restoration of Atlantic Forest landscapes that have been converted to pasture. In recently abandoned grazing areas with abundant cover of the exotic grass Brachiaria humidicola, 393 seedlings of 6 species were planted in two treatments: a mechanized planting system (soil prepared with a rotary tiller attached to a tractor; seedlings in polypropylene tubes) and a manual planting system (holes dug with a manual excavator; seedlings wrapped in polyethylene bags). After 12 months, survival (manual: 85%; mechanized: 71%) and growth rates (RGR_height: manual = 0.88 ± 0.06 and mechanized = 0.98 ± 0.06 cm/cm; RGR_diameter: manual = 0.77 ± 0.05 and mechanized = 0.86 ± 0.05 cm/cm) were high in both treatments, but no differences were found between them. Both planting systems proved efficient for planting native tree seedlings in pastures. The excellent results demonstrated in this study by the mechanized planting system are important because this cheap and readily available technique provides a good, but less frequently used, alternative to the manual planting system.     

Automated quality assurance and patient dosimetry in diagnostic radiology

It has been generally considered that improved methods of quality assurance would reduce the population dose from diagnostic radiology. This paper describes the development of a computerized method of automatically monitoring tube and generator parameters to perform on-line quality assurance, whilst undertaking various patient dosimetry measurements and calculations for each exposure. The method involves interfacing a microcomputer to a microprocessor controlled X-ray generator. Details of the various interfacing methods and modifications to the X-ray unit are given. The instrument enables quality assurance to be performed for every exposure by comparing tube and generator parameters against nominal settings. The software automatically warns the operator of any deviations from accepted limiting values. When a patient is examined, details of the examination and projection are entered into a database. The exposure area product and field size are monitored for each exposure. This data, together with information on tube potential and examination/projection is used to deduce patient entrance skin dose and energy imparted. Doses to individual organs are estimated using normalized organ dose data and a knowledge of tube potential and field size.     

Forensic age diagnostics of living individuals in criminal proceedings

Age estimations of living individuals are increasingly important in criminal matters. If doubts arise regarding the age of a person suspected of a criminal offense, forensic age estimation is prompted by the need to ascertain whether the person concerned has reached the age of criminal responsibility and whether general criminal law in force for older juveniles or adults is to be applied. According to the recommendations of the Arbeitsgemeinschaft für Forensische Altersdiagnostik (study group for forensic age diagnostics), age estimates in criminal proceedings should be based on the general physical examination, the X-ray examination of the hand and the odontological examination by a dentist, including dental status and orthopantomogram. In order to improve diagnostic reliability, these methods should always be used in combination, ensuring that each part is performed by forensically trained and experienced experts of the relevant disciplines. In order to demonstrate that the proband has reached the age of 21, an additional X-ray examination or CT scan of the clavicles is recommended. Future research projects should assess the variation for a combination of the above methods, quantify the impact of socio-economic status and ethnicity on the examined development systems and review the suitability of non-ionizing imaging methods of age estimation.     

An Automated System for Skeletal Maturity Assessment by Extreme Learning Machines

Assessing skeletal age is a subjective and tedious examination process. Hence, automated assessment methods have been developed to replace manual evaluation in medical applications. In this study, a new fully automated method based on content-based image retrieval and using extreme learning machines (ELM) is designed and adapted to assess skeletal maturity. The main novelty of this approach is it overcomes the segmentation problem as suffered by existing systems. The estimation results of ELM models are compared with those of genetic programming (GP) and artificial neural networks (ANNs) models. The experimental results signify improvement in assessment accuracy over GP and ANN, while generalization capability is possible with the ELM approach. Moreover, the results are indicated that the ELM model developed can be used confidently in further work on formulating novel models of skeletal age assessment strategies. According to the experimental results, the new presented method has the capacity to learn many hundreds of times faster than traditional learning methods and it has sufficient overall performance in many aspects. It has conclusively been found that applying ELM is particularly promising as an alternative method for evaluating skeletal age.     

Ceph-X: development and evaluation of 2D cephalometric system

Background

Cephalometric analysis and measurements of skull parameters using X-Ray images plays an important role in predicating and monitoring orthodontic treatment. Manual analysis and measurements of cephalometric is considered tedious, time consuming, and subjected to human errors. Several cephalometric systems have been developed to automate the cephalometric procedure; however, no clear insights have been reported about reliability, performance, and usability of those systems. This study utilizes some techniques to evaluate reliability, performance, and usability metric using SUS methods of the developed cephalometric system which has not been reported in previous studies.

Methods

In this study a novel system named Ceph-X is developed to computerize the manual tasks of orthodontics during cephalometric measurements. Ceph-X is developed by using image processing techniques with three main models: enhancements X-ray image model, locating landmark model, and computation model. Ceph-X was then evaluated by using X-ray images of 30 subjects (male and female) obtained from University of Malaya hospital. Three orthodontics specialists were involved in the evaluation of accuracy to avoid intra examiner error, and performance for Ceph-X, and 20 orthodontics specialists were involved in the evaluation of the usability, and user satisfaction for Ceph-X by using the SUS approach.

Results

Statistical analysis for the comparison between the manual and automatic cephalometric approaches showed that Ceph-X achieved a great accuracy approximately 96.6%, with an acceptable errors variation approximately less than 0.5 mm, and 1°. Results showed that Ceph-X increased the specialist performance, and minimized the processing time to obtain cephalometric measurements of human skull. Furthermore, SUS analysis approach showed that Ceph-X has an excellent usability user’s feedback.

Conclusions

The Ceph-X has proved its reliability, performance, and usability to be used by orthodontists for the analysis, diagnosis, and treatment of cephalometric.

     

Comparison of Cobb angles measured manually,calculated from 3-D spinal reconstruction,and estimated from torso asymmetry

While scoliotic spinal deformity is traditionally measured by the Cobb angle, we seek to estimate scoliosis severity from the torso surface without X-ray radiation. Here, we measured the Cobb angle in three ways: by protractor from postero-anterior X-ray, by computer from a 3-D digitized model of the vertebral body line, and by neural-network estimation from indices of torso surface asymmetry. The estimates of the Cobb angle by computer and by neural network were equally accurate in 153 records from 52 patients (standard deviation of 6 degrees from the Cobb angle, r=0.93), showing that torso asymmetry reliably predicted spinal deformity. Further improvements in predictive accuracy may require estimation of other 3-D indices of spinal deformity besides the Cobb angle with its wide measurement variability.     

Coexistence of intradural spinal arteriovenous malformation and associated developmental anomalies - report of two cases

Spinal arteriovenous malformations (AVM) have been devided into dural (Type I), intramedullary glomus (Type II), juvenile (Type III), and perimedullary direct arteriovenous fistulae (Type IV). AVMs are usually associated with subacute myelopathy in what has been known as Foix-Alajouanine syndrome. We presented two patients with two intradural spinal arteriovenous malformations associated in what we call Foix-Alajouanine syndrome. The both patient developed acute back pain and paresthesias, followed by paraplegia and incontinence. The clinical status of one patient has been improved after particle embolization for a 17 years when he deteriorated up to paraplegia after spinal angiography for follow up. Clinical status in another patient deteriorated, because particle emoblisation cannot be performed due to very descrete presentation of the feeding artery. Extensive neuroradiological examination in both patients revealed coexistence of numerous associated developmental anomalies in both patients. We conclude that arteriovenous malformations occasionally are associated with other vascular and nonvascular developmental anomalies elsewhere in the body. These findings rise attention about keep in mind the suspicion of mutual etiopathogenesis and congenital origin of these anomalies. Early timing of the diagnostic and therapeutic interventiosn are stressed to prevent or delay irreversible ishaemic myellopathy or haemorrhage. For the definitive diagnosis of spinal arteriovenous malformations and evaluation of its occlusion grade after the therapy spinal angiography is needed     

Segmentation of organs-at-risk in cervical cancer CT images with a convolutional neural network

PurposeWe introduced and evaluated an end-to-end organs-at-risk (OARs) segmentation model that can provide accurate and consistent OARs segmentation results in much less time.MethodsWe collected 105 patients’ Computed Tomography (CT) scans that diagnosed locally advanced cervical cancer and treated with radiotherapy in one hospital. Seven organs, including the bladder, bone marrow, left femoral head, right femoral head, rectum, small intestine and spinal cord were defined as OARs. The annotated contours of the OARs previously delineated manually by the patient’s radiotherapy oncologist and confirmed by the professional committee consisted of eight experienced oncologists before the radiotherapy were used as the ground truth masks. A multi-class segmentation model based on U-Net was designed to fulfil the OARs segmentation task. The Dice Similarity Coefficient (DSC) and 95th Hausdorff Distance (HD) are used as quantitative evaluation metrics to evaluate the proposed method.ResultsThe mean DSC values of the proposed method are 0.924, 0.854, 0.906, 0.900, 0.791, 0.833 and 0.827 for the bladder, bone marrow, femoral head left, femoral head right, rectum, small intestine, and spinal cord, respectively. The mean HD values are 5.098, 1.993, 1.390, 1.435, 5.949, 5.281 and 3.269 for the above OARs respectively.ConclusionsOur proposed method can help reduce the inter-observer and intra-observer variability of manual OARs delineation and lessen oncologists’ efforts. The experimental results demonstrate that our model outperforms the benchmark U-Net model and the oncologists’ evaluations show that the segmentation results are highly acceptable to be used in radiation therapy planning.     

Widening the lens: what the manual modality reveals about language,learning and cognition

The goal of this paper is to widen the lens on language to include the manual modality. We look first at hearing children who are acquiring language from a spoken language model and find that even before they use speech to communicate, they use gesture. Moreover, those gestures precede, and predict, the acquisition of structures in speech. We look next at deaf children whose hearing losses prevent them from using the oral modality, and whose hearing parents have not presented them with a language model in the manual modality. These children fall back on the manual modality to communicate and use gestures, which take on many of the forms and functions of natural language. These homemade gesture systems constitute the first step in the emergence of manual sign systems that are shared within deaf communities and are full-fledged languages. We end by widening the lens on sign language to include gesture and find that signers not only gesture, but they also use gesture in learning contexts just as speakers do. These findings suggest that what is key in gesture''s ability to predict learning is its ability to add a second representational format to communication, rather than a second modality. Gesture can thus be language, assuming linguistic forms and functions, when other vehicles are not available; but when speech or sign is possible, gesture works along with language, providing an additional representational format that can promote learning.