An automatic scanning method for high throughput microscopic system to facilitate medical genetic diagnosis: an initial study

Analytical Cellular Pathology

Chen

et al. 2013

Self Cite

Background: Auto-focusing is an important operation in high throughput imaging scanning. Although many auto-focusing methods have been developed and tested for a variety of imaging modalities, few investigations have been performed on the selection of an optimal auto-focusing method that is suitable for the pathological metaphase chromosome analysis under a high resolution scanning microscopic system.Objective: The purpose of this study is to investigate and identify an optimal auto-focusing method for the pathological metaphase chromosome analysis.Methods: In this study, five auto-focusing methods were applied and tested using metaphase chromosome images acquired from bone marrow and blood specimens. These methods were assessed by measuring a number of indices including execution time, accuracy, number of false maxima, and full width at half maximum (FWHM).Results: For the specific condition investigated in this study, the results showed that the Brenner gradient and threshold pixel counting methods were the optimal methods for acquiring high quality metaphase chromosome images from the bone marrow and blood specimens, respectively.Conclusions: Selecting an optimal auto-focusing method depends on the specific clinical tasks. This study also provides useful information for the design and implementation of the high throughput microscopic image scanning systems in the future digital pathology.

Section: Discussionmentioning

confidence: 99%

Evaluations of Auto-Focusing Methods under a Microscopic Imaging Modality for Metaphase Chromosome Image Analysis

Analytical Cellular Pathology

Chen

et al. 2013

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“…Recently, a new high throughput scanning method is reported in our laboratory [ 6 ]. Comparing to the currently commercialized scanners, our new method can accomplish a one-step scanning procedure, which directly provides the high resolution chromosome images for the following diagnosis (i.e., under 100x objective lens) [ 6 – 8 ]. In order to apply this technique to the future practice, on-line and off-line computer-aided detection (CAD) schemes are needed to be integrated into the image scanning procedure, for selecting the clinically analyzable metaphase chromosomes [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

Feature Selection for the Automated Detection of Metaphase Chromosomes: Performance Comparison Using a Receiver Operating Characteristic Method

Analytical Cellular Pathology

Song

et al. 2014

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Background. The purpose of this study is to identify a set of features for optimizing the performance of metaphase chromosome detection under high throughput scanning microscopy. In the development of computer-aided detection (CAD) scheme, feature selection is critically important, as it directly determines the accuracy of the scheme. Although many features have been examined previously, selecting optimal features is often application oriented. Methods. In this experiment, 200 bone marrow cells were first acquired by a high throughput scanning microscope. Then 9 different features were applied individually to group captured images into the clinically analyzable and unanalyzable classes. The performance of these different methods was assessed by a receiving operating characteristic (ROC) method. Results. The results show that using the number of labeled regions on each acquired image is suitable for the first on-line CAD scheme. For the second off-line CAD scheme, it would be suggested to combine four feature extraction methods including the number of labeled regions, average regions area, average region pixel value, and the standard deviation of either region distance or circularity. Conclusion. This study demonstrates an effective method of feature selection and comparison to facilitate the optimization of the CAD schemes for high throughput scanning microscope in the future.

“…[1][2][3][4][5][6][7][8][9][10] For this technique, however, one of the technical challenges is to maintain the pathologic specimen in focus during the image scanning, which may affect the reliability and efficiency of the image acquisition. The off-focused images can be attributed to several different factors, including the narrow depth of field (DOF) of an optical imaging system, and the impact of mechanical drifting and random vibrations of a scanning stage.…”

mentioning

confidence: 99%

Impact of the optical depth of field on cytogenetic image quality

Chen

et al. 2012

J. Biomed. Opt

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Abstract. In digital pathology, clinical specimen slides are converted into digital images by microscopic image scanners. Since random vibration and mechanical drifting are unavoidable on even high-precision moving stages, the optical depth of field (DOF) of microscopic systems may affect image quality, in particular when using an objective lens with high magnification power. The DOF of a microscopic system was theoretically analyzed and experimentally validated using standard resolution targets under 60× dry and 100× oil objective lenses, respectively. Then cytogenetic samples were imaged at in-focused and off-focused states to analyze the impact of DOF on the acquired image qualities. For the investigated system equipped with the 60× dry and 100× oil objective lenses, the theoretical estimation of the DOF are 0.855 μm and 0.703 μm, and the measured DOF are 3.0 μm and 1.8 μm, respectively. The observation reveals that the chromosomal bands of metaphase cells are distinguishable when images are acquired up to approximately 1.5 μm or 1 μm out of focus using the 60× dry and 100× oil objective lenses, respectively. The results of this investigation provide important designing trade-off parameters to optimize the digital microscopic image scanning systems in the future.