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1.
J Digit Imaging ; 34(1): 105-115, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33169211

RESUMEN

Artificial intelligence (AI) holds much promise for enabling highly desired imaging diagnostics improvements. One of the most limiting bottlenecks for the development of useful clinical-grade AI models is the lack of training data. One aspect is the large amount of cases needed and another is the necessity of high-quality ground truth annotation. The aim of the project was to establish and describe the construction of a database with substantial amounts of detail-annotated oncology imaging data from pathology and radiology. A specific objective was to be proactive, that is, to support undefined subsequent AI training across a wide range of tasks, such as detection, quantification, segmentation, and classification, which puts particular focus on the quality and generality of the annotations. The main outcome of this project was the database as such, with a collection of labeled image data from breast, ovary, skin, colon, skeleton, and liver. In addition, this effort also served as an exploration of best practices for further scalability of high-quality image collections, and a main contribution of the study was generic lessons learned regarding how to successfully organize efforts to construct medical imaging databases for AI training, summarized as eight guiding principles covering team, process, and execution aspects.


Asunto(s)
Inteligencia Artificial , Radiología , Algoritmos , Bases de Datos Factuales , Femenino , Humanos , Radiografía
2.
J Digit Imaging ; 32(2): 211-220, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30338476

RESUMEN

The use of digital imaging has substantially grown in recent decades, in traditional services, new specialties, and departments. The need to share these data among departments and caregivers necessitated central archiving systems that are able to communicate with various viewing applications and electronic medical records. This promoted the development of modern vendor neutral archive (VNA) systems. The need to aggregate and share imaging data from various departments promoted the development of enterprise-imaging (EI) solutions that replace departmental silos of data with central healthcare enterprise databases. To describe the implementation process of a VNA-EI solution in a large health system and its outcomes. We review the background of VNA and EI solutions development and describe the characteristics and advantages of such systems. We then describe our experience in implementation of these solutions in a large integrated healthcare delivery network in northeast Ohio. We then present the process, challenges, costs, advantages, and outcomes of such implementation. The VNA and EI solution was launched in December 2015 and is still ongoing. It currently includes 54 radiology and 26 cardiology sites affiliated with the University Hospitals health system. This process was associated with more than 10% cost savings, 30% reduction in storage costs, superior support for disaster recovery, and 80% decrease in unscheduled outages. All these were achieved despite a 120% increase in archive retrieval needs and a 40% growth in image production. Implementation of a VNA and EI solution was successful and resulted in numerous measurable and qualitative improvements in a large and growing health system.


Asunto(s)
Redes de Comunicación de Computadores , Diagnóstico por Imagen , Registros Electrónicos de Salud , Sistemas de Información Radiológica/organización & administración , Integración de Sistemas , Difusión de la Información , Almacenamiento y Recuperación de la Información , Ohio , Servicio de Radiología en Hospital
3.
Med Image Anal ; 49: 128-140, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30144652

RESUMEN

Four-dimensional (4D) flow magnetic resonance imaging (4D Flow MRI) enables acquisition of time-resolved three-directional velocity data in the entire heart and all major thoracic vessels. The segmentation of these tissues is typically performed using semi-automatic methods. Some of which primarily rely on the velocity data and result in a segmentation of the vessels only during the systolic phases. Other methods, mostly applied on the heart, rely on separately acquired balanced Steady State Free Precession (b-SSFP) MR images, after which the segmentations are superimposed on the 4D Flow MRI. While b-SSFP images typically cover the whole cardiac cycle and have good contrast, they suffer from a number of problems, such as large slice thickness, limited coverage of the cardiac anatomy, and being prone to displacement errors caused by respiratory motion. To address these limitations we propose a multi-atlas segmentation method, which relies only on 4D Flow MRI data, to automatically generate four-dimensional segmentations that include the entire thoracic cardiovascular system present in these datasets. The approach was evaluated on 4D Flow MR datasets from a cohort of 27 healthy volunteers and 83 patients with mildly impaired systolic left-ventricular function. Comparison of manual and automatic segmentations of the cardiac chambers at end-systolic and end-diastolic timeframes showed agreements comparable to those previously reported for automatic segmentation methods of b-SSFP MR images. Furthermore, automatic segmentation of the entire thoracic cardiovascular system improves visualization of 4D Flow MRI and facilitates computation of hemodynamic parameters.


Asunto(s)
Interpretación de Imagen Asistida por Computador/métodos , Angiografía por Resonancia Magnética/métodos , Disfunción Ventricular Izquierda/diagnóstico por imagen , Anciano , Algoritmos , Velocidad del Flujo Sanguíneo , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Disfunción Ventricular Izquierda/fisiopatología
4.
Spine Deform ; 6(2): 112-120.e1, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29413732

RESUMEN

STUDY DESIGN: Retrospective study. OBJECTIVES: To investigate parameters of axial vertebral deformation in patients with scoliosis compared to a control group, and to determine whether these parameters correlated with the severity of spine curvature, measured as the Cobb angle. SUMMARY OF BACKGROUND DATA: Adolescent idiopathic scoliosis (AIS) is the most common type of spinal deformity. Many studies have investigated vertebral deformation, in terms of wedging and pedicle deformations, but few studies have investigated actual structural changes within vertebrae. METHODS: This study included 20 patients with AIS (Lenke 1-3, mean age: 15.6 years, range: 11-20). We compared preoperative low-dose computed tomography (CT) examinations of patients with AIS to those of a control group matched for age and sex. The control individuals had no spinal deformity, but they were admitted to the emergency department for trauma CTs. We measured the Cobb angles and the axial vertebral rotation (AVR), axial vertebral body asymmetry (AVBA), and frontal vertebral body rotation (FVBR) for the superior end, inferior end, and apical vertebrae, with in-house-developed software. Correlations between entities were investigated with the Pearson correlation test. RESULTS: The average Cobb angles were 49.3° and 1.3° for the scoliotic and control groups, respectively. The patient and control groups showed significant differences in the AVRs of all three vertebra levels (p < .01), the AVBAs of the superior end and apical vertebrae (p < .008), and the FVBR of the apical vertebra (p = .011). Correlations were only found between the AVBA and FVBR in the superior end vertebra (r = 0.728, p < .001) and in the apical vertebra (r = 0.713, p < .001). CONCLUSIONS: Compared with controls, patients with scoliosis showed clear morphologic differences in the midaxial plane vertebrae. Differences in AVR, AVBA, and FVBR were most pronounced at the apical vertebra. The FVBR provided valuable additional information about the internal rotation and deformation of vertebrae. LEVEL OF EVIDENCE: Level III.


Asunto(s)
Escoliosis/diagnóstico por imagen , Curvaturas de la Columna Vertebral/diagnóstico por imagen , Columna Vertebral/diagnóstico por imagen , Adolescente , Niño , Femenino , Humanos , Cifosis/diagnóstico por imagen , Cifosis/cirugía , Masculino , Variaciones Dependientes del Observador , Rango del Movimiento Articular/fisiología , Estudios Retrospectivos , Escoliosis/fisiopatología , Escoliosis/cirugía , Curvaturas de la Columna Vertebral/fisiopatología , Columna Vertebral/anatomía & histología , Columna Vertebral/fisiopatología , Tomografía Computarizada por Rayos X/métodos , Adulto Joven
5.
J Digit Imaging ; 30(4): 406-412, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28083827

RESUMEN

The purpose of this study was to investigate the potential of using clinically provided spine label annotations stored in a single institution image archive as training data for deep learning-based vertebral detection and labeling pipelines. Lumbar and cervical magnetic resonance imaging cases with annotated spine labels were identified and exported from an image archive. Two separate pipelines were configured and trained for lumbar and cervical cases respectively, using the same setup with convolutional neural networks for detection and parts-based graphical models to label the vertebrae. The detection sensitivity, precision and accuracy rates ranged between 99.1-99.8, 99.6-100, and 98.8-99.8% respectively, the average localization error ranges were 1.18-1.24 and 2.38-2.60 mm for cervical and lumbar cases respectively, and with a labeling accuracy of 96.0-97.0%. Failed labeling results typically involved failed S1 detections or missed vertebrae that were not fully visible on the image. These results show that clinically annotated image data from one image archive is sufficient to train a deep learning-based pipeline for accurate detection and labeling of MR images depicting the spine. Further, these results support using deep learning to assist radiologists in their work by providing highly accurate labels that only require rapid confirmation.


Asunto(s)
Aprendizaje Automático , Imagen por Resonancia Magnética , Redes Neurales de la Computación , Sistemas de Información Radiológica , Columna Vertebral/diagnóstico por imagen , Vértebras Cervicales/diagnóstico por imagen , Humanos , Vértebras Lumbares/diagnóstico por imagen , Sensibilidad y Especificidad , Vértebras Torácicas/diagnóstico por imagen
6.
J Digit Imaging ; 30(1): 86-94, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27714473

RESUMEN

The workload of US radiologists has increased over the past two decades as measured through total annual relative value units (RVUs). This increase in RVUs generated suggests that radiologists' productivity has increased. However, true productivity (output unit per input unit; RVU per time) is at large unknown since actual time required to interpret and report a case is rarely recorded. In this study, we analyzed how the time to read a case varies between radiologists over a set of different procedure types by retrospectively extracting reading times from PACS usage logs. Specifically, we tested two hypotheses that; i) relative variation in time to read per procedure type increases as the median time to read a procedure type increases, and ii) relative rankings in terms of median reading speed for individual radiologists are consistent across different procedure types. The results that, i) a correlation of -0.25 between the coefficient of variation and median time to read and ii) that only 12 out of 46 radiologists had consistent rankings in terms of time to read across different procedure types, show both hypotheses to be without support. The results show that workload distribution will not follow any general rule for a radiologist across all procedures or a general rule for a specific procedure across many readers. Rather the findings suggest that improved overall practice efficiency can be achieved only by taking into account radiologists' individual productivity per procedure type when distributing unread cases.


Asunto(s)
Eficiencia , Radiólogos/estadística & datos numéricos , Carga de Trabajo , Humanos , Radiografía , Factores de Tiempo
7.
Med Image Anal ; 35: 327-344, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27567734

RESUMEN

The evaluation of changes in Intervertebral Discs (IVDs) with 3D Magnetic Resonance (MR) Imaging (MRI) can be of interest for many clinical applications. This paper presents the evaluation of both IVD localization and IVD segmentation methods submitted to the Automatic 3D MRI IVD Localization and Segmentation challenge, held at the 2015 International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI2015) with an on-site competition. With the construction of a manually annotated reference data set composed of 25 3D T2-weighted MR images acquired from two different studies and the establishment of a standard validation framework, quantitative evaluation was performed to compare the results of methods submitted to the challenge. Experimental results show that overall the best localization method achieves a mean localization distance of 0.8 mm and the best segmentation method achieves a mean Dice of 91.8%, a mean average absolute distance of 1.1 mm and a mean Hausdorff distance of 4.3 mm, respectively. The strengths and drawbacks of each method are discussed, which provides insights into the performance of different IVD localization and segmentation methods.


Asunto(s)
Imagenología Tridimensional/métodos , Disco Intervertebral/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Algoritmos , Humanos
8.
Int J Comput Assist Radiol Surg ; 12(3): 431-438, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27889861

RESUMEN

PURPOSE: The purpose of this study was to investigate how the use of multi-modal rigid image registration integrated within a standard picture archiving and communication system affects the efficiency of a radiologist while performing routine interpretations of cases including prior examinations. METHODS: Six radiologists were recruited to read a set of cases (either 16 neuroradiology or 14 musculoskeletal cases) during two crossover reading sessions. Each radiologist read each case twice, one time with synchronized navigation, which enables spatial synchronization across examinations from different study dates, and one time without. Efficiency was evaluated based upon time to read a case and amount of scrolling while browsing a case using Wilcoxon signed rank test. RESULTS: Significant improvements in efficiency were found considering either all radiologists simultaneously, the two sections separately and the majority of individual radiologists for time to read and for amount of scrolling. The relative improvement for each individual radiologist ranged from 4 to 32% for time to read and from 14 to 38% for amount of scrolling. CONCLUSION: Image registration providing synchronized navigation across examinations from different study dates provides a tool that enables radiologists to work more efficiently while reading cases with one or more prior examinations.


Asunto(s)
Eficiencia , Radiólogos , Sistemas de Información Radiológica , Humanos
9.
J Digit Imaging ; 30(2): 133-140, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27766443

RESUMEN

The aim of this study was to perform an operational improvement project targeted at the breast imaging reading workflow of mammography examinations at an academic medical center with its associated breast centers and satellite sites. Through careful analysis of the current workflow, two major issues were identified: stockpiling of paperwork and multiple worklists. Both issues were considered to cause significant delays to the start of interpreting screening mammograms. Four workflow changes were suggested (scanning of paperwork, worklist consolidation, use of chat functionality, and tracking of case distribution among trainees) and implemented in July 2015. Timestamp data was collected 2 months before (May-Jun) and after (Aug-Sep) the implemented changes. Generalized linear models were used to analyze the data. The results showed significant improvements for the interpretation of screening mammograms. The average time elapsed for time to open a case reduced from 70 to 28 min (60 % decrease, p < 0.001), report turn-around time with preliminary signature decreased from 151 to 107 min (29 % decrease, p < 0.001), and report turn-around time final signature from 153 to 139 min (9 % decrease, p = 0.002). These improvements were achieved while keeping the efficiency of the workflow for diagnostic mammograms at large unaltered even with increased volume of mammography examinations (31 % increase of 4344 examinations for May-Jun to 5678 examinations for Aug-Sep). In conclusion, targeted efforts to improve the breast imaging reading workflow for screening mammograms in a teaching environment provided significant performance improvements without affecting the workflow of diagnostic mammograms.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Mamografía/estadística & datos numéricos , Flujo de Trabajo , Detección Precoz del Cáncer , Femenino , Humanos
10.
J Digit Imaging ; 29(6): 670-676, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27099222

RESUMEN

The purpose of this study was to determine if any of the factors radiologist, examination category, time of week, and week effect PACS usage, with PACS usage defined as the sequential order of computer commands issued by a radiologist in a PACS during interpretation and dictation. We initially hypothesized that only radiologist and examination category would have significant effects on PACS usage. Command logs covering 8 weeks of PACS usage were analyzed. For each command trace (describing performed activities of an attending radiologist interpreting a single examination), the PACS usage variables number of commands, number of command classes, bigram repetitiveness, and time to read were extracted. Generalized linear models were used to determine the significance of the factors on the PACS usage variables. The statistical results confirmed the initial hypothesis that radiologist and examination category affect PACS usage and that the factors week and time of week to a large extent have no significant effect. As such, this work provides direction for continued efforts to analyze system data to better understand PACS utilization, which in turn can provide input to enable optimal utilization and configuration of corresponding systems. These continued efforts were, in this work, exemplified by a more detailed analysis using PACS usage profiles, which revealed insights directly applicable to improve PACS utilization through modified system configuration.


Asunto(s)
Radiólogos/estadística & datos numéricos , Sistemas de Información Radiológica/estadística & datos numéricos , Humanos , Auditoría Administrativa/métodos , Factores de Tiempo
11.
J Am Coll Radiol ; 13(7): 812-818.e2, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27026579

RESUMEN

PURPOSE: The aim of this study was to investigate the state of integration between PACS and other IT systems relevant to radiologists' routine work across US academic radiology departments (ARDs). The results were intended to assess readiness for the ongoing transition to value-based health care by providing insights into currently challenging areas of integration but also areas associated with high levels of anticipated workflow efficiency improvements. METHODS: A cross-sectional survey was conducted using an online survey approved by the Society of Chairs of Academic Radiology Departments and sent to its members. Collected responses were analyzed with descriptive statistics and Fisher's exact tests. RESULTS: The response rate was 26% (34 of 132 members), and the respondents covered a large spectrum of ARDs considering location, size aspects, year of PACS introduction, and filmless production. Most notable findings included widespread high-level integration of PACS with dictation systems (>90%), low penetration of integration between PACS and critical notification systems (15%), and an overall better integration of PACS and radiology information systems (82%) than of PACS and electronic medical records (47%). CONCLUSIONS: Integration supporting radiologists' personal productivity is well spread among US ARDs, but as we transition into a value-based health care delivery model, there is a need to focus further integration efforts on systems with the greatest potential to document value in a patient-centric setting. Examples of such focus areas include integration of PACS and electronic medical records, adoption of vendor-neutral archives, and the use of workflow management systems.


Asunto(s)
Centros Médicos Académicos/organización & administración , Registros Electrónicos de Salud/organización & administración , Encuestas de Atención de la Salud , Registro Médico Coordinado , Servicio de Radiología en Hospital/organización & administración , Sistemas de Información Radiológica/estadística & datos numéricos , Centros Médicos Académicos/estadística & datos numéricos , Registros Electrónicos de Salud/estadística & datos numéricos , Modelos Organizacionales , Servicio de Radiología en Hospital/estadística & datos numéricos , Integración de Sistemas , Estados Unidos
12.
Int J Comput Assist Radiol Surg ; 11(9): 1731-41, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26932337

RESUMEN

PURPOSE: To present a semi-automatic method with minimal user interaction for quantitative analysis of the patellofemoral motion pattern. METHODS: 4D CT data capturing the patellofemoral motion pattern of a continuous flexion and extension were collected for five patients prone to patellar luxation both pre- and post-surgically. For the proposed method, an observer would place landmarks in a single 3D volume, which then are automatically propagated to the other volumes in a time sequence. From the landmarks in each volume, the measures patellar displacement, patellar tilt and angle between femur and tibia were computed. RESULTS: Evaluation of the observer variability showed the proposed semi-automatic method to be favorable over a fully manual counterpart, with an observer variability of approximately 1.5[Formula: see text] for the angle between femur and tibia, 1.5 mm for the patellar displacement, and 4.0[Formula: see text]-5.0[Formula: see text] for the patellar tilt. The proposed method showed that surgery reduced the patellar displacement and tilt at maximum extension with approximately 10-15 mm and 15[Formula: see text]-20[Formula: see text] for three patients but with less evident differences for two of the patients. CONCLUSIONS: A semi-automatic method suitable for quantification of the patellofemoral motion pattern as captured by 4D CT data has been presented. Its observer variability is on par with that of other methods but with the distinct advantage to support continuous motions during the image acquisition.


Asunto(s)
Tomografía Computarizada Cuatridimensional/métodos , Articulación Patelofemoral/diagnóstico por imagen , Rango del Movimiento Articular , Adolescente , Adulto , Automatización , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Articulación Patelofemoral/fisiología , Adulto Joven
13.
Comput Med Imaging Graph ; 49: 16-28, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26878138

RESUMEN

A multiple center milestone study of clinical vertebra segmentation is presented in this paper. Vertebra segmentation is a fundamental step for spinal image analysis and intervention. The first half of the study was conducted in the spine segmentation challenge in 2014 International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI) Workshop on Computational Spine Imaging (CSI 2014). The objective was to evaluate the performance of several state-of-the-art vertebra segmentation algorithms on computed tomography (CT) scans using ten training and five testing dataset, all healthy cases; the second half of the study was conducted after the challenge, where additional 5 abnormal cases are used for testing to evaluate the performance under abnormal cases. Dice coefficients and absolute surface distances were used as evaluation metrics. Segmentation of each vertebra as a single geometric unit, as well as separate segmentation of vertebra substructures, was evaluated. Five teams participated in the comparative study. The top performers in the study achieved Dice coefficient of 0.93 in the upper thoracic, 0.95 in the lower thoracic and 0.96 in the lumbar spine for healthy cases, and 0.88 in the upper thoracic, 0.89 in the lower thoracic and 0.92 in the lumbar spine for osteoporotic and fractured cases. The strengths and weaknesses of each method as well as future suggestion for improvement are discussed. This is the first multi-center comparative study for vertebra segmentation methods, which will provide an up-to-date performance milestone for the fast growing spinal image analysis and intervention.


Asunto(s)
Algoritmos , Vértebras Lumbares/diagnóstico por imagen , Reconocimiento de Normas Patrones Automatizadas/métodos , Vértebras Torácicas/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Tomografía Computarizada por Rayos X/normas , Anciano , Anciano de 80 o más Años , California , Femenino , Humanos , Masculino , Persona de Mediana Edad , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Validación de Programas de Computación , Técnica de Sustracción , Tomografía Computarizada por Rayos X/estadística & datos numéricos
14.
J Digit Imaging ; 29(3): 301-8, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26510753

RESUMEN

Information technology systems within health care, such as picture archiving and communication system (PACS) in radiology, can have a positive impact on production but can also risk compromising quality. The widespread use of PACS has removed the previous feedback loop between radiologists and technologists. Instead of direct communication of quality discrepancies found for an examination, the radiologist submitted a paper-based quality-control report. A web-based issue-reporting tool can help restore some of the feedback loop and also provide possibilities for more detailed analysis of submitted errors. The purpose of this study was to evaluate the hypothesis that data from use of an online error reporting software for quality control can focus our efforts within our department. For the 372,258 radiologic examinations conducted during the 6-month period study, 930 errors (390 exam protocol, 390 exam validation, and 150 exam technique) were submitted, corresponding to an error rate of 0.25 %. Within the category exam protocol, technologist documentation had the highest number of submitted errors in ultrasonography (77 errors [44 %]), while imaging protocol errors were the highest subtype error for computed tomography modality (35 errors [18 %]). Positioning and incorrect accession had the highest errors in the exam technique and exam validation error category, respectively, for nearly all of the modalities. An error rate less than 1 % could signify a system with a very high quality; however, a more likely explanation is that not all errors were detected or reported. Furthermore, staff reception of the error reporting system could also affect the reporting rate.


Asunto(s)
Errores Diagnósticos , Garantía de la Calidad de Atención de Salud/métodos , Sistemas de Información Radiológica/normas , Radiología/normas , Gestión de Riesgos/organización & administración , Programas Informáticos , Errores Diagnósticos/estadística & datos numéricos , Diagnóstico por Imagen/normas , Humanos , Control de Calidad , Gestión de Riesgos/métodos
15.
J Digit Imaging ; 29(1): 47-58, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26353749

RESUMEN

In this paper, statistical analysis and techniques from process mining are employed to analyze interaction patterns originating from radiologists reading medical images in a picture archiving and communication system (PACS). Event logs from 1 week of data, corresponding to 567 cases of single-view chest radiographs read by 14 radiologists, were analyzed. Statistical analysis showed that the numbers of commands and command types used by the radiologists per case only have a slightly positive correlation with the time to read a case (0.31 and 0.55, respectively). Further, one way ANOVA showed that the factors time of day, radiologist and specialty were significant for the number of commands per case, whereas radiologist was also significant for the number of command types, but with no significance of any of the factors on time to read. Applying process mining to the event logs of all users showed that a seemingly "simple" examination (single-view chest radiographs) can be associated with a highly complex interaction process. However, repeating the process discovery on each individual radiologist revealed that the initially discovered complex interaction process consists of one group of radiologists with individually well-structured interaction processes and a second smaller group of users with progressively more complex usage patterns. Future research will focus on metrics to describe derived interaction processes in order to investigate if one set of interaction patterns can be considered as more efficient than another set when reading radiological images in a PACS.


Asunto(s)
Eficiencia Organizacional/estadística & datos numéricos , Radiografía Torácica/estadística & datos numéricos , Sistemas de Información Radiológica/estadística & datos numéricos , Radiología/estadística & datos numéricos , Flujo de Trabajo , Análisis de Varianza , Humanos
16.
Comput Med Imaging Graph ; 38(7): 549-57, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25066008

RESUMEN

This paper describes the concept of eigenspine, a concept applicable for determining the correlation between pair-wise combinations of measures useful for describing the three-dimensional spinal deformities associated with adolescent idiopathic scoliosis. The proposed data analysis scheme is based upon the use of principal component analysis (PCA) and canonical correlation analysis (CCA). PCA is employed to reduce the dimensionality of the data space, thereby providing a regularization of the measurements, and CCA is employed to determine the linear dependence between pair-wise combinations of different measures. The usefulness of the eigenspine concept is demonstrated by analyzing the position and the rotation of all lumbar and thoracic vertebrae as obtained from 46 patients suffering from adolescent idiopathic scoliosis. The analysis showed that the strongest linear relationship is found between the lateral displacement and the coronal rotation of the vertebrae, and that a somewhat weaker but still strong correlation is found between the coronal rotation and the axial rotation of the vertebrae. These results are well in-line with the general understanding of idiopathic scoliosis. Noteworthy though is that the correlation between the anterior-posterior displacement and the sagittal rotation was not as strong as expected and that the obtained results further indicate the need for including the axial vertebral rotation as a measure when characterizing different types of idiopathic scoliosis. Apart from analyzing pair-wise correlations between different measures, the method is believed to be suitable for finding a maximally descriptive low-dimensional combination of measures describing spinal deformities in idiopathic scoliosis.


Asunto(s)
Imagenología Tridimensional/métodos , Vértebras Lumbares/diagnóstico por imagen , Reconocimiento de Normas Patrones Automatizadas/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Escoliosis/diagnóstico por imagen , Vértebras Torácicas/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adolescente , Algoritmos , Interpretación Estadística de Datos , Femenino , Humanos , Masculino , Análisis Numérico Asistido por Computador , Posicionamiento del Paciente/métodos , Análisis de Componente Principal , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Rotación , Sensibilidad y Especificidad , Estadística como Asunto
17.
Genesis ; 52(10): 833-48, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25074687

RESUMEN

Matrix metalloproteinases (MMPs) are a large and complex family of zinc-dependent endoproteinases widely recognized for their roles in remodeling the extracellular matrix (ECM) during embryonic development, wound healing, and tissue homeostasis. Their misregulation is central to many pathologies, and they have therefore been the focus of biomedical research for decades. These proteases have also recently emerged as mediators of neural development and synaptic plasticity in vertebrates, however, understanding of the mechanistic basis of these roles and the molecular identities of the MMPs involved remains far from complete. We have identified a zebrafish orthologue of mmp25 (a.k.a. leukolysin; MT6-MMP), a membrane-type, furin-activated MMP associated with leukocytes and invasive carcinomas, but which we find is expressed by a subset of the sensory neurons during normal embryonic development. We detect high levels of Mmp25ß expression in the trigeminal, craniofacial, and posterior lateral line ganglia in the hindbrain, and in Rohon-Beard cells in the dorsal neural tube during the first 48 h of embryonic development. Knockdown of Mmp25ß expression with morpholino oligonucleotides results in larvae that are uncoordinated and insensitive to touch, and which exhibit defects in the development of sensory neural structures. Using in vivo zymography, we observe that Mmp25ß morphant embryos show reduced Type IV collagen degradation in regions of the head traversed by elongating axons emanating from the trigeminal ganglion, suggesting that Mmp25ß may play a pivotal role in mediating ECM remodeling in the vicinity of these elongating axons.


Asunto(s)
Ganglios Sensoriales/enzimología , Metaloproteinasas de la Matriz Asociadas a la Membrana/metabolismo , Células Receptoras Sensoriales/enzimología , Proteínas de Pez Cebra/metabolismo , Pez Cebra/embriología , Animales , Colágeno Tipo IV/metabolismo , Embrión no Mamífero/enzimología , Desarrollo Embrionario , Matriz Extracelular/enzimología , Femenino , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/metabolismo , Ganglios Sensoriales/embriología , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Masculino , Metaloproteinasas de la Matriz Asociadas a la Membrana/genética , Especificidad de Órganos , Homología de Secuencia de Aminoácido , Pez Cebra/genética , Pez Cebra/metabolismo , Proteínas de Pez Cebra/genética
18.
Phys Med Biol ; 59(2): 311-26, 2014 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-24351846

RESUMEN

Detailed analysis of spinal deformity is important within orthopaedic healthcare, in particular for assessment of idiopathic scoliosis. This paper addresses this challenge by proposing an image analysis method, capable of providing a full three-dimensional spine characterization. The proposed method is based on the registration of a highly detailed spine model to image data from computed tomography. The registration process provides an accurate segmentation of each individual vertebra and the ability to derive various measures describing the spinal deformity. The derived measures are estimated from landmarks attached to the spine model and transferred to the patient data according to the registration result. Evaluation of the method provides an average point-to-surface error of 0.9 mm ± 0.9 (comparing segmentations), and an average target registration error of 2.3 mm ± 1.7 (comparing landmarks). Comparing automatic and manual measurements of axial vertebral rotation provides a mean absolute difference of 2.5° ± 1.8, which is on a par with other computerized methods for assessing axial vertebral rotation. A significant advantage of our method, compared to other computerized methods for rotational measurements, is that it does not rely on vertebral symmetry for computing the rotational measures. The proposed method is fully automatic and computationally efficient, only requiring three to four minutes to process an entire image volume covering vertebrae L5 to T1. Given the use of landmarks, the method can be readily adapted to estimate other measures describing a spinal deformity by changing the set of employed landmarks. In addition, the method has the potential to be utilized for accurate segmentations of the vertebrae in routine computed tomography examinations, given the relatively low point-to-surface error.


Asunto(s)
Simulación por Computador , Procesamiento de Imagen Asistido por Computador/métodos , Escoliosis/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Femenino , Humanos , Masculino , Columna Vertebral/diagnóstico por imagen
19.
Med Image Anal ; 17(8): 1073-94, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23906631

RESUMEN

Graphics processing units (GPUs) are used today in a wide range of applications, mainly because they can dramatically accelerate parallel computing, are affordable and energy efficient. In the field of medical imaging, GPUs are in some cases crucial for enabling practical use of computationally demanding algorithms. This review presents the past and present work on GPU accelerated medical image processing, and is meant to serve as an overview and introduction to existing GPU implementations. The review covers GPU acceleration of basic image processing operations (filtering, interpolation, histogram estimation and distance transforms), the most commonly used algorithms in medical imaging (image registration, image segmentation and image denoising) and algorithms that are specific to individual modalities (CT, PET, SPECT, MRI, fMRI, DTI, ultrasound, optical imaging and microscopy). The review ends by highlighting some future possibilities and challenges.


Asunto(s)
Algoritmos , Gráficos por Computador/instrumentación , Gráficos por Computador/tendencias , Interpretación de Imagen Asistida por Computador/instrumentación , Interpretación de Imagen Asistida por Computador/métodos , Procesamiento de Señales Asistido por Computador/instrumentación , Diseño de Equipo , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
20.
Phys Med Biol ; 58(6): 1775-87, 2013 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-23442302

RESUMEN

Reliable measurements of spinal deformities in idiopathic scoliosis are vital, since they are used for assessing the degree of scoliosis, deciding upon treatment and monitoring the progression of the disease. However, commonly used two dimensional methods (e.g. the Cobb angle) do not fully capture the three dimensional deformity at hand in scoliosis, of which axial vertebral rotation (AVR) is considered to be of great importance. There are manual methods for measuring the AVR, but they are often time-consuming and related with a high intra- and inter-observer variability. In this paper, we present a fully automatic method for estimating the AVR in images from computed tomography. The proposed method is evaluated on four scoliotic patients with 17 vertebrae each and compared with manual measurements performed by three observers using the standard method by Aaro-Dahlborn. The comparison shows that the difference in measured AVR between automatic and manual measurements are on the same level as the inter-observer difference. This is further supported by a high intraclass correlation coefficient (0.971-0.979), obtained when comparing the automatic measurements with the manual measurements of each observer. Hence, the provided results and the computational performance, only requiring approximately 10 to 15 s for processing an entire volume, demonstrate the potential clinical value of the proposed method.


Asunto(s)
Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/patología , Rotación , Escoliosis/diagnóstico por imagen , Escoliosis/patología , Tomografía Computarizada por Rayos X/métodos , Adolescente , Automatización , Humanos , Imagenología Tridimensional , Variaciones Dependientes del Observador
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