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Machine Learning Algorithms Utilizing Quantitative CT Features May Predict Eventual Onset of Bronchiolitis Obliterans Syndrome After Lung Transplantation

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ACADEMIC RADIOLOGY 2018年第9期25卷 1201-1212页

作者： Barbosa, Eduardo J. Mortani, Jr. Lanclus, Maarten Vos, Wim Van Holsbeke, Cedric De Backer, William De Backer, Jan Lee, James Univ Penn Sch Med Dept Radiol Perelman Sch Med 3400 Spruce St Philadelphia PA 19104 USA Univ Penn Sch Med Dept Med Perelman Sch Med 3400 Spruce St Philadelphia PA 19104 USA FLUIDDA Nv Kontich Belgium Univ Hosp Antwerp Dept Resp Med Edegem Belgium

Rationale and Objectives: Long-term survival after lung transplantation (LTx) is limited by bronchiolitis obliterans syndrome (BOS), defined as a sustained decline in forced expiratory volume in the first second (FEV1) not explained by other causes. We assessed whether machine learning (ML) utilizing quantitative computed tomography (qCT) metrics can predict eventual development of BOS. Materials and Methods: Paired inspiratory-expiratory CT scans of 71 patients who underwent LTx were analyzed retrospectively (BOS [n = 41] versus non-BOS [n = 30]), using at least two different time points. The BOS cohort experienced a reduction in FEV1 of >10% compared to baseline FEV1 post LTx. Multifactor analysis correlated declining FEV1 with qCT features linked to acute inflammation or BOS onset. Student t test and ML were applied on baseline qCT features to identify lung transplant patients at baseline that eventually developed BOS. Results: The FEV1 decline in the BOS cohort correlated with an increase in the lung volume (P = .027) and in the central airway volume at functional residual capacity (P = .018), not observed in non-BOS patients, whereas the non-BOS cohort experienced a decrease in the central airway volume at total lung capacity with declining FEV1 (P = .039). Twenty-three baseline qCT parameters could significantly distinguish between non-BOS patients and eventual BOS developers (P < .05), whereas no pulmonary function testing parameters could. Using ML methods (support vector machine), we could identify BOS developers at baseline with an accuracy of 85%, using only three qCT parameters. Conclusions: ML utilizing qCT could discern distinct mechanisms driving FEV1 decline in BOS and non-BOS LTx patients and predict eventual onset of BOS. This approach may become useful to optimize management of LTx patients.

关键词： Lung transplantation quantitative CT metrics computer-assisted image processing lung transplant rejection bronchiolitis obliterans syndrome

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Craniopagus: The Suriname-Amsterdam conjunction

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CHILDS NERVOUS SYSTEM 2004年第8-9期20卷 625-634页

作者： van Ouwerkerk, WJR van den Berg, R Allison, CE Sibarani, R van Wijk, JAE Smit, LME ten Voorde, BJ de Munck, J Kurk, CA Velthuys, ME van Leeuwen, E Bemmel, L Vandertop, WP Vrije Univ Amsterdam Med Ctr Dept Neurosurg NL-1007 MB Amsterdam Netherlands Vrije Univ Amsterdam Med Ctr Dept Neuroradiol Amsterdam Netherlands Vrije Univ Amsterdam Med Ctr Dept Pediat Anesthesiol Amsterdam Netherlands Vrije Univ Amsterdam Med Ctr Dept Pediat & Pediat Nephrol Amsterdam Netherlands Vrije Univ Amsterdam Med Ctr Dept Pediat Neurol Amsterdam Netherlands Vrije Univ Amsterdam Med Ctr Dept Phys & Med Technol Amsterdam Netherlands Vrije Univ Amsterdam Med Ctr Dept Rehabil Amsterdam Netherlands Vrije Univ Amsterdam Med Ctr Dept Occupat Therapy Amsterdam Netherlands Vrije Univ Amsterdam Med Ctr Dept Med Eth & Philosophy Amsterdam Netherlands Diaconessen Hosp Dept Pediat Paramaribo Suriname

Objects. A case of a Suriname female occipito-parietal to occipito-parieto-temporal craniopagus twins is described. The girls were transferred to the VU University Medical Center (VUmc) in Amsterdam, the Netherlands, for further diagnostics and to analyze whether surgical separation was feasible and ethically justifiable. The multifactorial aspects of different treatment options are discussed. Methods. The twins underwent multiple investigations by a multidisciplinary team. Advanced imaging techniques with 3D-CT scan, MRI and MRA scans, image fusion techniques and, most importantly, cerebral angiography with balloon occlusion tests were performed. Conclusions. Because of a shared venous ring, with preferential drainage to the left child, and which endovascular balloon occlusion showed could not be separated, surgical separation of the twins with a fair chance of survival without additional neurological damage and with prospects of a good quality of life was regarded as impossible. In accordance with the parents' wishes, the twins were not separated and offered optimal integral conservative treatment.

关键词： computer-assisted image processing cerebral angiography balloon occlusion medical ethics rehabilitation conjoined twins

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Visualization and quality assessment of the contrast transfer function estimation

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JOURNAL OF STRUCTURAL BIOLOGY 2015年第2期192卷 222-234页

作者： Sheth, Lisa K. Piotrowski, Angela L. Voss, Neil R. Roosevelt Univ Dept Biol Chem & Phys Sci Schaumburg IL 60173 USA

The contrast transfer function (CTF) describes an undesirable distortion of image data from a transmission electron microscope. Many users of full-featured processing packages are often new to electron microscopy and are unfamiliar with the CTF concept. Here we present a common graphical output to clearly demonstrate the CTF fit quality independent of estimation software. Separately, many software programs exist to estimate the four CTF parameters, but their results are difficult to compare across multiple runs and it is all but impossible to select the best parameters to use for further processing. A new measurement is presented based on the correlation falloff of the calculated CTF oscillations against the normalized oscillating signal of the data, called the CTF resolution. It was devised to provide a robust numerical quality metric of every CTF estimation for high-throughput screening of micrographs and to select the best parameters for each micrograph. These new CTF visualizations and quantitative measures will help users better assess the quality of their CTF parameters and provide a mechanism to choose the best CTF tool for their data. (C) 2015 Elsevier Inc. All rights reserved.

关键词： Contrast transfer function Transmission electron microscopy Cryo-electron microscopy methods computer-assisted image processing

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Counting the platelets: a robust and sensitive quantification method for thrombus formation

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THROMBOSIS AND HAEMOSTASIS 2016年第6期115卷 1178-1190页

作者： Claesson, Kjersti Lindahl, Tomas L. Faxalv, Lars Linkoping Univ Dept Clin & Expt Med SE-58183 Linkoping Sweden

Flow chambers are common tools used for studying thrombus formation in vitro. However, the use of such devices is not standardised and there is a large diversity among the flow chamber systems currently used, and also in the methods used for quantifying the thrombus development. It was the study objective to evaluate a new method for analysis and quantification of platelet thrombus formation that can facilitate comparison of results between research groups. Whole blood was drawn over a collagen patch in commercial Ibid or in-house constructed PDMS flow chambers. Five percent of the platelets were fluorescently labelled and z-stack time-lapse images were captured during thrombus formation. images were processed in a Python script in which the number of platelets and their respective x-, y- and z-positions were obtained. For comparison with existing methods the platelets were also labelled and quantified using fluorescence intensity and thrombus volume estimations by confocal microscopy. The presented method was found less sensitive to microscope and image adjustments and provides more details on thrombus development dynamics than the methods for measuring fluorescence intensity and thrombus volume estimation. The platelet count method produced comparable results with commercial and PDMS flow chambers, and could also obtain information regarding the stability of each detected platelet in the thrombus. In conclusion, quantification of thrombus formation by platelet count is a sensitive and robust method that enables measurement of platelet accumulation and platelet stability in an absolute scale that could be used for comparisons between research groups.

关键词： Platelet aggregation microfluidics thrombosis fluorescence microscopy computer-assisted image processing

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A novel semi-automatic segmentation method for volumetric assessment of the colon based on magnetic resonance imaging

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ABDOMINAL IMAGING 2015年第7期40卷 2232-2241页

作者： Sandberg, Thomas Holm Nilsson, Matias Poulsen, Jakob Lykke Gram, Mikkel Frokjaer, Jens Brondum Ostergaard, Lasse Riis Drewes, Asbjorn Mohr Aalborg Univ Hosp Mech Sense Dept Gastroenterol & Hepatol DK-9000 Aalborg Denmark Aalborg Univ Hosp Mech Sense Dept Radiol DK-9000 Aalborg Denmark Aalborg Univ Dept Hlth Sci & Technol Aalborg Denmark Aalborg Univ Dept Clin Med Aalborg Denmark

To develop a novel semi-automatic segmentation method for quantification of the colon from magnetic resonance imaging (MRI). Fourteen abdominal T2-weighted and dual-echo Dixon-type water-only MRI scans were obtained from four healthy subjects. Regions of interest containing the colon were outlined manually on the T2-weighted images. Segmentation of the colon and feces was obtained using k-means clustering and image registration. Regional colonic and fecal volumes were obtained. Inter-observer agreement between two observers was assessed using the Dice similarity coefficient as measure of overlap. Colonic segmentations showed wide variation in volume and morphology between subjects. Colon volumes of the four healthy subjects for both observers were (median [interquartile range]) ascending colon 200 mL [169.5-260], transverse 200.5 mL [113.5-242.5], descending 148 mL [121.5-178.5], sigmoid-rectum 277 mL [192-345], and total 819 mL [687-898.5]. Overlap agreement for the total colon segmentation between the two observers was high with a Dice similarity coefficient of 0.91 [0.84-0.94]. The colon volume to feces volume ratio was on average 0.7. Regional colon volumes were comparable to previous findings using fully manual segmentation. The method showed good agreement between observers and may be used in future studies of gastrointestinal disorders to assess colon and fecal volume and colon morphology. Novel insight into morphology and quantitative assessment of the colon using this method may provide new biomarkers for constipation and abdominal pain compared to radiography which suffers from poor reliability.

关键词： Colon Magnetic resonance imaging Machine learning Artificial intelligence computer-assisted image processing Constipation

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computer-PROGRAMS FOR THE ANALYSIS OF IMMUNOHISTOCHEMICALLY LABELED SPINAL-CORD SECTIONS

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JOURNAL OF NEUROSCIENCE METHODS 1990年第2期31卷 119-132页

作者： JOHNSON, EM BULLITT, E UNIV N CAROLINA DEPT NEUROSURG CHAPEL HILL NC 27599 USA

A microcomputer based image processing system has been developed to analyze the density of immunohistochemical labeling within neural tissue. The system permits the tracing of anatomical regions seen on a digitized image and the determination of the area and the mean gray level of all pixels lying within each defined region. Corrections are made for uneven screen illumination and for nonlinearity of the video camera''s response to graduations in optical density. A standardization procedure ensures that the same level of incident illumination is used during each experiment. An example of an application of this system is described in which unilateral changes in immunohistochemical staining density were determined within the rodent spinal cord following partial spinal injury. This system provides a sensitive and objective means of analyzing such changes.

关键词： computer-assisted image processing Spinal cord Immunohistochemistry Dorsal horn Central canal Substance P Enkephalin Serotonin Somatostatin

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Volumetric difference evaluation of registered three-dimensional pre-operative and post-operative CT dental data

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DENTOMAXILLOFACIAL RADIOLOGY 2012年第4期41卷 328-339页

作者： Economopoulos, T. L. Asvestas, P. A. Matsopoulos, G. K. Molnar, B. Windisch, P. Natl Tech Univ Athens Sch Elect & Comp Engn GR-10682 Athens Greece Technol Educ Inst Athens Dept Med Instruments Technol Athens Greece Semmelweis Univ Dept Periodontol Budapest Hungary

Objective: The purpose of this study is to propose a complete methodology for automatically registering three-dimensional (3D) pre-operative and post-operative CT scan dental volumes as well as to provide a toolset for quantifying and evaluating their volumetric differences. Methods: The proposed methodology was applied to cone beam CT (CBCT) data from 20 patients in order to assess the volume of augmented bone in the alveolar region. In each case, the pre-operative and post-operative data were registered using a 3D affine-based scheme. The performance of the 3D registration algorithm was evaluated by measuring the average distance between the edges of the registered sets. The differences between the registered sets were assessed through 3D subtraction radiography. The volume of the differences was finally evaluated by defining regions of interest in each slice of the subtracted 3D data and by combining all respective slices to model the desired volume of interest. The effectiveness of the algorithm was verified by applying it to several reference standard-shaped objects with known volumes. Results: Satisfactory alignment was achieved as a low average offset of 1.483 +/- 1.558 mm was recorded between the edges of the registered sets. Moreover, the estimated volumes closely matched the volumes of the reference objects used for verification, as the recorded volume differences were less than 0.4 mm(3) in all cases. Conclusion: The proposed method allows for automatic registration of 3D CBCT data sets and the volumetric assessment of their differences in particular areas of interest. The proposed approach provides accurate volumetric measurements in three dimensions, requiring minimal user interaction. Dentomaxillofacial Radiology (2012) 41, 328-339. doi: 10.1259/dmfr/94040044

关键词： computer-assisted image processing digital subtraction radiography volumetric computed tomography alveolar ridge augmentation

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Surface models and gradually peeled volume model to explore hand structures

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ANNALS OF ANATOMY-ANATOMISCHER ANZEIGER 2017年 211卷 202-206页

作者： Chung, Beom Sun Kwon, Koojoo Shin, Byeong-Seok Chung, Min Suk Ajou Univ Sch Med Dept Anat 164 Worldcup Ro Suwon 16499 South Korea Inha Univ Dept Comp Engn 100 Inha Ro Incheon 22212 South Korea

This study was intended to confirm whether simultaneous examination of surface and volume models contributes to learning of hand structures. Outlines of the skin, muscles, and bones of the right hand were traced in sectioned images of a male cadaver to create surface models of the structures. After the outlines were filled with selected colors, the color-filled sectioned images were stacked to produce a volume model of the hand, from which the skin was gradually peeled. The surface models provided locational orientation of the hand structures such as extrinsic and intrinsic hand muscles, while the peeled volume model revealed the depth of the individual hand structures. In addition, the characteristic appearances of the radial artery and the wrist joint were confirmed. The exploration of the volume model accompanied by equivalent surface models is synergistically helpful for understanding the morphological properties of hand structures. (C) 2017 Elsevier GmbH. All rights reserved.

关键词： Visible Human Projects Hand Muscles Three-dimensional imaging computer-assisted image processing

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Advanced procedures in reconstructive and function-preserving orbital surgery by computer-assisted presurgical planning (CAPP) and computer-assisted surgery (CAS)

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HNO 2005年第5期53卷 428-+页

作者： Zizelmann, C Schramm, A Schön, R Ridder, GJ Maier, W Schipper, J Gellrich, NC Univ Klinikum Freiburg Univ Klin Hals Nasen & Ohrenheilkunde & Poliklin D-79106 Freiburg Germany Univ Freiburg Klinikum Arbeitsgruppe Interdisziplinare Rekonstrukt Funkt Freiburg Germany

Background. Orbital reconstruction after tumor or trauma makes high demands on the surgeon when restoring the optic axis and cosmetic features. computer-assisted preoperative planning surgery (CAPP) and computer-assisted surgery (CAS) allow calculation of the form of the orbital cavity to be reconstructed preoperatively as well as the process of its realization intraoperatively. Methods. We developed new planning software methods for this surgical procedure. For validation the deviation of accuracy was assessed between the virtual and the real model in eight patients with surgical reconstruction of the orbit. Results. The check of accuracy of the reconstructions compared to the planning of the surgery by fusion of preoperative and postoperative data resulted in a mean deviation of 1.74 mm. The volumetric measurements presented a mean deviation of 0.2 cm(3) with an accuracy of > 99%. The accuracy of linear measurements with the techniques of image fusion of the "feature-based" method was 0.38 mm and thus close to the technical threshold of effective. data accuracy of 0.35 mm. The enophthalmus could be assessed more objectively with this method compared to using the Hertel index. Conclusions. CAPP and CAS are helpful in reconstructive orbital surgery to verify the position of the optic axis and the cosmetic result intraoperatively.

关键词： computer-assisted image processing computer-assisted treatment volume measurement image fusion optic axis hertel index orbit pathology orbit surgery orbital neoplasms

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Intraoperative imaging and visualization

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ONKOLOGE 2020年第1期26卷 31-42页

作者： Maier-Hein, Lena Gockel, Ines Speidel, Stefanie Wendler, Thomas Teber, Dogu Maerz, Keno Tizabi, Minu Nickel, Felix Navab, Nassir Mueller-Stich, Beat Deutsch Krebsforschungszentrum Abt Comp Assistierte Med Intervent CAMI Neuenheimer Feld 223 D-69120 Heidelberg Germany Univ Klinikum Leipzig Dept Operat Med DOPM Klin & Poliklin Viszeral Transplantat Thorax & Ge Leipzig Germany Natl Ctr Tumorerkrankungen NCT Dresden Abt Translat Chirurg Onkol Dresden Germany Tech Univ Dresden Ctr Tactile Internet Human Loop CeTI Dresden Germany Tech Univ Munich Lehrstuhl Informat Anwendungen Med & Augmented Re Garching Germany SurgicEye GmbH Munich Germany Stadt Klinikum Karlsruhe Urol Klin Karlsruhe Germany Univ Klinikum Heidelberg Klin Allgemein Viszeral & Transplantat Chirurg Heidelberg Germany

Background. Surgical oncology is an important pillar of interdisciplinary cancer treatment. The intraoperative visualization of tumors and critical structures along with functional tissue parameters is an important basis for precise surgical treatment and thus for the optimization of patient outcome. Objective. The aim of this article was to compile the latest technological developments with particular relevance to intraoperative imaging and visualization. Methods. Medical and technical experts with experience in computer-assisted surgery identified four research areas with a high potential for sustainably improving surgical oncology: (1) functional imaging based on biophotonics, (2) multimodal data visualization through augmented reality, (3) reproducible imaging by means of robotics, and (4) context-aware visualization based on surgical data science. Results. Recent publications exemplify the high potential of the four subject areas presented. Conclusion. Future research should focus on optimizing robustness and integrability into the surgical workflow.

关键词： Diagnostic Imaging computer-assisted image processing Augmented reality Patient-specificmodeling Robotics

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