JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN BIOMEDICAL ENGINEERING SEGMENTATION AND ANALYSIS OF MICROSCOPIC AND MICROARRAY BONE IMAGES ANAND JATTI Assistant Professor, (Research Scholar, VTU, Belgaum), Instrumentation Technology Department, R.V.College of Engineering, Bangalore, Karnataka, India anandjatti@yahoo.com ABSTRACT : Analysis of human bone cross sections represents a major area of research in bone biology. The normal bone and bone cancer ‘Osteosarcoma’ case has been taken up for the current study, since it is the most frequent type of bone tumor and is most common between the ages of 15 to 25. One of the biggest challenges faced in image analysis is at the microscopic cellular level of bone and also at its gene level. In this paper analysis of microarray and microscopic images of normal human and osteosarcoma has been done. Using microarrays, expression levels of thousands of genes can be measured simultaneously. In Microarray experiment, the labeled nucleic acids are derived from the miRNA of a bone sample and so the microarray measures the gene expression. From this technique, the obtained microarray image consists of genes responsible for osteosarcoma case, by quantification of such genes of bone cell, able us to know the comparative study between the normal and abnormal case of human bone tissue. In biomedical research, the revolution of microscopy imaging of large amount of image data renders manual visual analysis impossible, requiring automated image analysis systems. The qualitative analysis of digital microscopic images provides better visualization to human, becomes the predominant. And the quantitative information of such images pertains to morphology of the object (tumor) under study or its function, therefore extraction of such information from images is the main issue to be tackled. KEY WORDS:- Bone Cancer Osteosarcoma, Image Processing, Microscopic Image Analysis, Micro Array Image Analysis. 1. INTRODUCTION The Human bone cancer case ‘Osteosarcoma’ also called as Osteogenic sarcoma is a malignant primitive bone tumor, usually developing in children and adolescents, with a high tendency to metastasize. Metastasis is the dissemination of cancer cells from the primary tumor to a distant organ and represents the most frequent cause of death for patients with cancer. This project work has two implications, First, at gene level analysis of human bone tissue of both normal and osteosarcoma case is through microarray technique, in which the microarray images were produced through a series of steps and procedure at genetic laboratory and it is analyzed for intensity extraction of each miRNA detected spot in the image which corresponds to single gene expression. The intensity of miRNA can be compared in both the normal and abnormal bone tissue. The microRNA are single stranded RNA molecules of about 21 to 23 nucleotides in length which regulates gene expression, and these are transcribed from DNA but not translated into proteins. miRNA microarray is a high throughput method for studying microRNA expressions in cultured cells or tissues which facilitates the study of biological roles of microRNA. A Microarray consists of a grid of tiny spots of DNA printed on a surface, with each spot usually corresponding to a different gene. miRNA, reflecting which genes are currently active, is extracted from cells and processed to form single stranded nucleic acids labeled with fluorescent molecules. The labeled nucleic acids bind to their corresponding microarray spot. The microarray is then scanned with a laser confocal microscope (Agilent Scanner). The Microscopic images are obtained through the snap shot of microscopic picture on slide by a digital camera. The importance of Image processing of microarray and microscopic are as follows: The analysis of digital microarray and microscopic images of human bone samples obtain qualitative and quantitative results. Microarray qualitative includes Gridding, spot finding and background correction. Microarray quantitative analysis was useful in providing the intensity levels of each miRNA detected spots which correspond to the single gene expression. Microscopic qualitative analysis gives detailed information about the processing of the foreground and background of the digital images which contained cancerous cells. The microscopic ISSN: 0975 – 6752 | NOV 09 TO OCT 10 | Volume 1, Issue 1 Page 1 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN BIOMEDICAL ENGINEERING quantitative analysis provides the information about the area of affected cells in a given digital image. 2. MATERIALS AND METHODOLOGY A. Materials used for Microscopic Images: The glass slides of the biopsy samples are placed below the digital camera focusing point and the digital microscopic pictures were taken for further analysis. B. Materials used for Microarray Images: The normal and osteosarcoma of human bone sample tissue shown in Fig.1 was obtained in the form of FFPE from the Institute of Oncology. The FFPE tissues have been widely used to archive samples obtained from biopsies of human bone cancers and diseased tissues like linked to genetic abnormalities. The FFPE samples are then given for the RNA extraction for further process. The following are the samples for the analysis: Normal Bone Osteosarcoma Fig.1 FFPE samples of Normal bone and Osteosarcoma tissue. Methodology Methodology for Microscopic Image Analysis: The procedure and techniques carried out for bone image analysis is shown in flow chart. Fig.2 Work flow chart. Image acquisition: Image acquisition is the first process involved. The microscopic bone cross section image acquired by using electronic microscope. Biological aspect of bone: Important features in the bone cross section such as harvesian canals, osteons, osteon fragments, lamellar bone, bony trabeculae, myxoid matrix and artifact for different age groups and also for age related developments are observed. Image format conversion: The digital image obtained using electronic microscope is in RGB (Red, Green and Blue) format and converted to grey level image for further processing. The MATLAB tool is used for image format conversion from RGB to gray level. Pre processing of an image: The preprocessing operation is carried out to extract details that are obscured in an image or to highlight and classify certain features of an interest in an image. The tumor cells in a digital microscopic image is analyzed and processed by using MATLAB Image processing toolbox. Microscopic bone images were analyzed through following steps: The morphological operations are applied to image, for the extraction of the image components. The Watershed segmentation technique used to enhance the tumor cells in the image. The average area of tumor is then calculated with respect to the total image area in terms of pixels and tabulated results. Methodology for Microarray Image Analysis: The importance of Image processing of DNA microarray is as follows: The analysis of digital DNA microarray images of human bone samples obtains qualitative and quantitative results. DNA Microarray qualitative image analysis includes gridding, spot finding and background correction [4]. DNA Microarray quantitative image analysis was useful in providing the intensity levels of each miRNA detected spots which correspond to the single gene expression. The steps of DNA Micro array Image formation from bone samples are as follows RNA extraction from FFPE bone samples. Labeling and Hybridization - Control and test miRNA samples are processed on the same array using Cyanine-3 fluorophore. Scanning and feature extraction. miRNA profile is obtained. The obtained DNA Microarray image for both normal and osteosarcoma human bone samples were analyzed through Gene Spring software. 3. RESULTS Results of Microscopic Image Processing: The tumor cells in a digital microscopic image is analyzed and processed by using MATLAB Image processing toolbox. Microscopic bone images were analyzed through following steps: ISSN: 0975 – 6752 | NOV 09 TO OCT 10 | Volume 1, Issue 1 Page 2 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN BIOMEDICAL ENGINEERING The morphological operations are applied to image, to extract the image components. The Watershed segmentation technique used to enhance the tumor cells in the image. The average area of tumor are then calculated with respect to the total image area in terms of pixels and tabulated for total of twelve images. The image processing algorithm was applied to digital images. Qualitative analysis includes morphological operations such as background suppression, enhancement of contrast and watershed segmentation. Quantitative analysis includes the measurement of area of tumors in the image by segmentation of each tumor pixel. The result of one tumor image is presented in this paper. The input image can be seen in Fig.3 (a). The results for these images are shown correspondingly. Morphological Operation: To perform morphological operations on an image, the image has to be in binary format, thus input image is converted to binary image as shown in Fig.3 (a), (b) and (c). (a) (b) (c) Fig.4 (a) Imposed minima (b) Watershed (c) Labeled regions Measurement of Area: The average area of the tumor or cancerous cells in an image is found and calculated with respect to the total area of the input image in terms of pixels. Following steps are performed to obtain the quantitative measurement of microscopic image. First the Histogram plot of gray scale image has been taken. Histogram is a construction of the counts of pixels with particular amplitude value as shown in Fig.5 (a). It enhances the contrast of the original image through equal intensity distribution. The enhanced image is converted to binary image by fixing a threshold either 0(black) or white (1) as shown in Fig.5 (b). (a) (b) (c) Fig.3 (a) Original Image. (b) Binary Image Dilation into any watershed region are given a pixel value of zero. View the label matrix as an image using “label2rgb’ as shown in Fig.4(c). RGB color image is for the purpose of visualizing labeled regions. c) Watershed Segmentation Technique: Fig.4 (a) detects all intensity valleys below a particular threshold with the ‘imextendedmin’ function. The output of the ‘imextendedmin’ is a binary image. The location rather than the size of the regions in the ‘imextendedmin’ image is important. The “watershed” function returns a label matrix containing non negative numbers that correspond to watershed regions in Fig.4 (b).Pixels that do not fall (a) (b) ISSN: 0975 – 6752 | NOV 09 TO OCT 10 | Volume 1, Issue 1 Page 3 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN BIOMEDICAL ENGINEERING (c) Fig.5 (a) Histogram plot. (b) Threshold (c) Labeled regions Individual’s grains are labeled with different colors as shown in Fig.5(c) and extracted area gray level values from detected objects can be seen in Fig.5 (a). Looking at the edges of the detected grain by finding the perimeter pixels of the image using ‘bwperim’. Different colors for different perimeter pixels are assigned as shown in Fig.5(b). Background is suppressed by using the subtraction method. (b) Fig.7 (a) Comparison of size distribution. (b) Final detected grains. The summation of area of detected grains or tumor is found out with respect to the total area of the image in terms of pixels. The table shows the total area (in pixel) of the image and affected area (average tumor area), and area unaffected (without tumor). Table 1: Sample case study of Bone Normal and Abnormal samples (Osteosarcoma). Image Osteo1 (a) Osteo2 Norma l1 Norma l2 b) (c) Fig.6 Segmentation without background. (b) New Size distribution. (c) Bordered objects removed. Total Area (in pixel) 30000 00 30000 00 56250 0 56250 0 Area affecte d (in pixel) 147513 32855 Area unaffec ted (in pixel) 285248 7 287660 0 529645 14276 548224 123400 Results from DNA Micro Array Technique: The images obtained after scanning are subjected to image analysis using the FE. Later these are analyzed by Gene Spring GX 10, for further analysis. The sample given was one normal and one osteosarcoma bone FFPE tissue, the replication of each sample was done for the comparison purpose. Thus generated total four images, two from control sample (Normal tissue), and two from non control sample (abnormal or osteosarcoma tissue).Microarray image of normal and osteosarcoma case can be seen in Fig.8. Segmentation is done once more after image subtraction to get clear distinction between detected objects. New areas then extracted after segmentation can be seen in Fig.6 (b). Comparison of original and background size distribution is done. Removal of partial grain cut off by edges to get clear distinction can be seen in Fig.6(c). Fig.8 DNA Microarray Image. (a) Normal or control. (b) osteosarcoma or Non control. (a) The data analysis is done by using the software GeneSpring, version GX 10. Provides powerful, accessible statistical tools for fast visualization and analysis of expression data. Designed specially for ISSN: 0975 – 6752 | NOV 09 TO OCT 10 | Volume 1, Issue 1 Page 4 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN BIOMEDICAL ENGINEERING the needs of biologists. GeneSpring GX offers an interactive desktop computing environment that promotes investigation and enables understanding of DNAmicro array data within a biological context. The obtained intensity values of miRNA detected in normal and abnormal were tabulated and generated cluster, scatter plots. The intensities and background subtracted were taken from the raw data file generated from feature extraction. The obtained values and image from the feature extraction is further subjected to data analysis by the use of GeneSpring GX 10.The sum of background subtracted signals for each repeated miRNA was calculated. To compare between the samples further normalization (50th percentile normalization) step was performed. (50th percentile normalization: values below 0.01 were set 0.01.Each measurement was divided by the 50th percentile of all measurements).After experiment, the total number of probes in array excluding controls is:11180.Number of miRNA’s repeated more than one time with different probe ids:534.The repeated miRNA were grouped in both normal and cancer bone, as shown in the Table.1. Table 2. miRNA detection in cancer and normal tissue. Group miRNA Detected Cancer tissue compared to normal bone 32 Normal bone compared to cancer tissue 75 The ‘Fold change’ cutoffs have been widely used in microarray assays to identify genes that are differentially expressed between query (cancerous) and references (normal) samples. More accurate measures of differential expression and data normalization strategies are required to identify high confidence sets of genes with biologically meaningful changes in transcription. The results are obtained and tabulated, then plotted for the same. The Heat map was generated for the arrays hybridized based on summed background-subtracted signals of each repeated miRNA’s. The overview of all the miRNA’s in the array is as shown in the form of cluster in the Fig.9. Fig.9 Overview of all the miRNA’s in an array. Yellow: Non detected miRNA’s. Green: miRNA with low detection level. Red: miRNA with low detection level. Scatter plot showing the miRNA’s distributed based on their expression values miRNA’s in Red blocks indicate the miRNA’s detected. These are shown in scatter plot can be seen in Fig.10. Fig.10 Scatter plot showing the miRNA’s distributed based on their expression values miRNA’s in Red Blocks indicates the miRNA’s detected in cancer bone (fold>1) compared to normal bone (fold<0.5). All the red blocks fall under positive values. Note: X axis: Cancer bone and Y axis: Normal bone. Line Plot: Line plot is created for the values of both normal and cancerous bone and also only for cancer bone can be seen in Fig.11.The plot provides the comparison between normal and abnormal tissues. Plot in blue color indicates the cancer and red plot indicates the normal fold values. 5 Fol d_Canc Ti s s ue hs a-mi R-24 Fol d_N Bone 4 hs a-mi R-33b hs a-mi R-15b 3 hs a-mi R-143 hs a-mi R-107 hs a-mi R-26a hs a-mi R-452* hs a-mi R-320 hs a-mi R-422b hs a-mi R-30c hs a-mi R-433 hs a-mi R-130a hs a-mi R-103 hs a-mi R-203 hs2a-mi R-101 hs a-mi R-152 hs a-mi R-106b hs a-mi R-138 hs a-mi R-16 hs a-mi R-200b hs a-mi R-330 hs a-mi R-30e-5p 1 hs a-mi R-629 hs a-mi R-496 hs a-mi R-495 hs a-mi R-564 hs a-mi R-568 hs a-mi R-616 hs a-mi R-641 hs a-mi R-615 hs a-mi R-487a hs a-mi R-520d* hs ahs miR a hs -m -10 a- iR 1 m hs iR 103 a hs -m 106 a- iR b m hs iR 107 a- -1 hs miR 30a a- hs miR 138 a hs -miR 143 a- m 1 h iR 52 hs sa- -15 a- miR b m hs iR -16 a- -2 m 0 hs iR 0b a hs -m 203 a- iR h m -2 hs sa iR- 4 a- -m 26 m iR a iR hs -3 30 a- 0e c hs miR -5 a- - p hs miR 320 a hs -m -33 a- iR 0 m hs iR 33b a hs -m 422 a- iR b hs miR -43 a- - 3 m 4 hs iR 52* a- -4 h m 87 hs sa- iR-4 a a- miR 9 m - 5 hs iR-5 496 a- 2 hs miR 0d* a- hs miR 564 a- hs miR 568 a- hs miR 615 a- hs miR 616 a- m 62 iR 9 -6 41 0 -1 -2 (a) ISSN: 0975 – 6752 | NOV 09 TO OCT 10 | Volume 1, Issue 1 Page 5 JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN BIOMEDICAL ENGINEERING (b) Fig.11 Line plot. (a) Expression level of detected miRNA’s in Normal bone. (b) Line graph of cancer bone. All the miRNA’s expression level are >1. The graph represents the fold values of the detected miRNA’s in cancer bone. X-axis-miRNA’s, Y-axis: Fold value. 4. DISCUSSION AND CONCLUSION The work presented in this project shows some very interesting results in a field where very little research has been done on bone image analysis. The Human Bone samples are obtained from the Institute of Oncology, of both normal and osteosarcoma case has been taken up and they are analyzed at genetic level (microarray) and microscopic cellular level. The Emerging Microarray Technology has been utilized to get the microarray image of human bone samples for both normal and osteosarcoma case, and intensity of each detected miRNA in both normal and osteosarcoma has been tabulated. The miRNA quantification is achieved from this powerful technique. The microarray image analysis of bone in MATLAB provides a way to extract the intensity of gene expression or which corresponds to each spot in the image. The microscopic images are analyzed and the area of tumor in the images are obtained and tabulated in the results. Dark spots indicate tumors in all the three cancerous images are segmented and the area of each spot is calculated. This is useful to know the area of tumor present and can be diagnosed accordingly. 5. FUTURE ENHANCEMENTS The detected miRNA expression for the human bone sample from the microarray technique, are associated with clinical variables of cancers, so the miRNA’s can be readily used for cancer diagnosis and prognosis. Each detected miRNA in cancer can be studied for further research and drug development. The major roles of miRNA’s in regulating genetic regulatory circuit and also in the response of immune system give us a clue of the impact miRNA would have on Vaccine research and development. 6. 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Maruf Monwar of Siamak De Zai, “A parallel processing approach for performation Extraction from Microarray images”, IEEE, May 2006 [7] Basim Alhaddi, Hussam Nawwaf Fakhouri & Omar S.AlMousa, “DNA Microarray Genome Image processing using fixed spot position”, American journal of applied Sciences 3(2): 1730-1734, 2006. [8] Robert S.H. Istepanian, “Microarray image processing: Current status & future Directions” IEEE Transactions on NanoBioScience, Vol.2, No.4, December 2003. [9] R.C.Y. Cheung, Christopher J.S.Desilva, “Analysis of Gene Microarray Image”, centre for intelligent information processing Systems, IEEE 1999. 7. ACKNOWLEDGEMENT I acknowledge for their support for the smooth completion of the project work to the Department of Science and Technology (DST), Government of India, New Delhi for giving financial support for carrying out this project work. ISSN: 0975 – 6752 | NOV 09 TO OCT 10 | Volume 1, Issue 1 Page 6