Biomedical subjects

Chungnan Lee

Publications and source records attributed to Chungnan Lee.

4 recordsLinked to original sources

PubMed2006

Projection profile analysis for identifying different views of chest radiographs.

RATIONALE AND OBJECTIVES: For computerized analysis of chest images in the clinical environment, identification of frontal (posteroanterior/anteroposterior) and lateral chest radiographs is an important preprocessing step. In this study, we developed a method to distinguish frontal from lateral views of the chest radiographs based on an analysis of the projection profile. MATERIALS AND METHODS: Projection profile is obtained by projecting a chest image on to the mediolateral axis. Two indices, body symmetry index and background percentage index, are computed from the projection profile. The combination of body symmetry index and background percentage index is used to determine the view of chest radiographs. The method is evaluated on a sample of 2000 frontal and 1000 lateral chest images. RESULTS: The values of body symmetry index are found to be 1.18 +/- 0.23 and 3.07 +/- 1.42 for frontal and lateral chest images, respectively. The values of background percentage index are found to be 0.03 +/- 0.05 and 0.33 +/- 0.09 for frontal and lateral chest images, respectively. The discrimination is evaluated by linear discriminant analysis and receiver operating characteristic analysis. Area Az under the receiver operating characteristic curve with the combination of the two indices is 0.993. CONCLUSION: The method can be used as a preprocessing step for further analysis in chest radiographs.

Algorithms↗

PubMed2006

Projection profile analysis for automated detection of abnormalities in chest radiographs.

Abnormalities in chest images often present as abnormal opacity or abnormal asymmetry. We have developed a novel method for automated detection of abnormalities in chest radiographs by use of these features. Our method is based on an analysis of the projection profile obtained by projecting the pixels data of a frontal chest image on to the mediolateral axis. Two indices, lung opacity index and lung symmetry index, are computed from the projection profile. Lung opacity index and lung symmetry index are then combined to detect gross abnormalities in chest radiographs. The values of lung opacity index are found to be 0.38 +/- 0.05 and 0.37 +/- 0.06 for normal right and left lung, respectively. The values of lung symmetry index are found to be 0.018 +/- 0.014 for normal chest images. The discrimination for the combination of the two indices is evaluated by linear discriminant analysis and receiver operating characteristic (ROC) analysis. Area Az under the ROC curve with the combination of the two indices in the classification of normal and abnormal chest images is 0.963.

Adolescent↗

PubMed2006

MultiPrimer: software for multiplex primer design.

This study presents a novel application, MultiPrimer, to assist users to design multiplex PCR primers. MultiPrimer adopts an algorithm based on a genetic algorithm and can efficiently solve the multi-objective optimisation problem. A match pattern model is proposed to speed up examination of the specificity constraint. MultiPrimer is able to find a set of primer pairs simultaneously for a set of gene family sequences and multiple targets for a single cDNA sequence. A public version of the MultiPrimer software is available from http://edith.cse.nsysu.edu.tw/new/software/MultiPrimer.htm.

Algorithms↗

PubMed2004

Primer design using genetic algorithm.

MOTIVATION: Before performing a polymerase chain reaction experiment, a pair of primers to clip the target DNA subsequence is required. However, this is a tedious task as too many constraints need to be satisfied. Various kinds of approaches for designing a primer have been proposed in the last few decades, but most of them do not have restriction sites on the designed primers and do not satisfy the specificity constraint. RESULTS: The proposed algorithm imitates nature's process of evolution and genetic operations on chromosomes in order to achieve optimal solutions, and is a best fit for DNA behavior. Experimental results indicate that the proposed algorithm can find a pair of primers that not only obeys the design properties but also has a specific restriction site and specificity. Gel electrophoresis verifies that the proposed method really can clip out the target sequence. AVAILABILITY: A public version of the software is available on request from the authors.

Algorithms↗