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An Efficient Brain Tumor Extraction from MRI Images using Entropy Measures 2014-15
Poornima University, Jaipur M. Tech. (CE) Page 1
Chapter1: Introduction
Image processing is an active research area in which medical image processing is a
highly challenging field techniques are used to process of creation of visual
representation of the inner portions of the human body for medical diagnosis.
Information is conveyed through images. Image processing is a process where input
image is processed to get output also as an image. Main aim of all image processing
techniques is to recognize the image or object under consideration easier visually. All
the images used in todays world are in the digital format. Medical images are images
that show the physical attributes distribution. Medical imaging modalities as in MRI,
CT scan mostly depend on computer technology to generate or display digital images of
the internal organs of the human body which helps the doctors to visualize the inner
portions of the body. CT scanner, Ultrasound and Magnetic Resonance Imaging took
over conventional x-ray imaging, by allowing the doctors see the body's third
dimension. Brain tumor is a serious life altering disease condition. Image segmentation
plays a significant role in image processing as it helps in the extraction of suspicious
regions from the medical images. For this the segmentation of brain MRI images are
done for detection of Tumor location. Magnetic Resonance Imaging is an important
diagnostic imaging technique utilized for early detection of abnormal changes in tissues
and organs. Tumor is an uncontrolled growth of tissues in any part of the body. Most
Research in developed countries show that the number of people who have brain tumors
were died due to the fact of inaccurate detection. However this method of detection
resists the accurate determination of stage &size of tumor. To avoid that a computer
aided method for segmentation (detection) of brain tumor based on the various entropy
measures has been used.
1.1 Brain anatomy overview
BRAIN, the central processing unit of human body, is a soft, delicate and spongy mass
of tissues. It is a steady place for signals to enter and being processed. The brain directs
the things we choose to do (like walking and talking) and the things our body does without
thinking (like breathing). The brain is also in charge of our senses (sight, hearing, touch, taste,
and smell), memory, emotions, and personality. The human brain which functions as the
center for the control of all the parts of human body is a highly specialized organ that
allows a human being to adapt and endure varying environmental conditions. The
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An Efficient Brain Tumor Extraction from MRI Images using Entropy Measures 2014-15
Poornima University, Jaipur M. Tech. (CE) Page 2
human brain enables a human to articulate words, execute actions, and share thoughts
and feelings. In this section the tissue structure and anatomical parts of the brain are
described to understand the purpose of this study.
So, before dealing with the brain tumors and MRI Images, the basic structure of human
brain must be well understood.
Fig. 1.1 The Major Subdivision Of Human Brain [19]
Following are the main parts of the human brain:
1.1.1 Brainstem: It is the lower extension of the brain where it connects to the spinal
cord. Neurological functions located in the brainstem include these necessary for
survival (breathing, digestion, heart rate, blood pressure) and for arousal (being awake
and alert). The brainstem is the pathway for all fiber tracts passing up and down from
peripheral, nerves and spinal cord to the highest parts of the brain.
1.1.2 Cerebellum: The portion of the brain (located at the back) which helps coordinate
movement (balance and music coordination).
1.1.3 Frontal Lobe: It is the front part of the brain and is involved in planning,
organizing, problem solving, selective attention, personality and a variety of higher
cognitive functions including behavior and emotions.
1.1.4 Occipital Lobe: It is the region in the back of the brain which processes visual
information. It also contains association areas that help in the visual recognition of
shapes and colors.
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1.1.5 Parietal Lobe: One of the two parietal lobes of the brain are located behind the
frontal lobe at the top of the brain.
1.1.6 Temporal Lobe: There are two temporal lobes, one on each side of the brain
located at above the level of ears. These lobes allow a person to tell one smell from
another. They also help in sorting new information and are believed to be responsible
for short term memory.
The human brain which functions as the center for the control of all the parts of human
body is a highly specialized organ that allows a human being to adapt and endure
varying environmental conditions. The human brain enables a human to articulate
words, execute actions, and share thoughts and feelings.
1.2 Brain Tumors
Under certain conditions, brain cells grow and multiply uncontrollably because for some
reasons the mechanism that control normal cells is unable to regulate the growth of the
brain cells. The abnormal mass of brain tissue is the brain tumor that occupies space in
the skull and interrupts the normal functions of brain and creates an increasing pressure
in the brain. Due to increased pressure on the brain, some brain tissues are shifted,
pushed against the skull or are responsible for the damage of the nerves of the other
healthy brain tissues.
Scientists have classified brain tumor according to the location of the tumor, type of
tissue involved whether they are noncancerous or cancerous. The site of the origin
(primary of secondary) and other factors involved. World Health Organization (WHO)
classified brain tumor into 120 types. This classification is done on the basis of the cell
origin and the behavior of the cell from less aggressive to more aggressive behavior.
Even, some tumor types are graded ranging from grade I (less malignant) to grade IV
(more malignant). This signifies the rate of the growth despite of variations in grading
systems which depends on the type of the tumor.
Grade I: The tissue is benign. The cells look nearly like normal brain cells, and they
grow slowly. This type of brain Tumors are rare in adults.
Grade II: The tissue is relatively slow growing and sometimes spread to nearby normal
tissues and become malignant. The cells look less like normal cells than do the cells in a
Grade I tumor.
Grade III: These are the malignant tissue and have cells that look very different from
normal cells. The abnormal cells are actively growing (anaplastic).
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Poornima University, Jaipur M. Tech. (CE) Page 4
Grade IV: These cover the most malignant tissue and have cells that look most
abnormal and tend to grow quickly. Tumor forms new blood vessels to maintain rapid
growth.
Primary brain tumors are the tumors that originated in the brain and are named for the
cell types from which they originated. They can be benign (non-cancerous) and
malignant (cancerous). Benign tumors grow slowly and do not spread elsewhere or
invade the surrounding tissues. However, occupying a short space, even the less
aggressive tumor can exercise much pressure on the brain and makes it dysfunctional.
Conversely, more aggressive tumors can grow more quickly and spread to other tissues.
Each of these tumors has unique clinical, radiographic and biological characteristics.
Secondary brain tumors originate from another part of the body. These tumors consist of
cancer cells somewhere else in the body that have metastasized or spread to the brain
The most common cause of secondary brain tumors are: lung cancer, breast cancer,
melanoma, kidney cancer, bladder cancer, certain sarcomas, and testicular and germ cell
tumors.
1.3 MRI Images
Raymond V. Damadian invented MRI in 1969 and was the first person to use MRI to
investigate the human body. Eventually, MRI became the most preferred imaging
technique in radiology because MRI enabled internal structures be visualized in some
detail. In MRI signal processing considers signal emissions. The imaging process does
not involve the use of ionizing radiation and hence does not have the associated
potential harmful effects. It is a tomographic imaging technique that produces images of
internal physical and chemical characteristics of an object from externally measured
Nuclear Magnetic Resonance (NMR) signals. MR imaging is based on the well-known
NMR phenomenon. MR signals used for image formation come directly from the object
itself. With MRI, good contrast between different soft tissues of the body can be
observed. This makes MRI suitable for providing better quality images for the brain, the
muscles, the heart and cancerous tissues compared with other medical imaging
techniques, such as Computed Tomography (CT) or X-rays. Magnetic Resonance
Imaging (MRI) used in radiology to investigate the anatomy and physiology of the body
in both health and disease. MRI scanners use magnetic fields and radio waves to form
images of the body. The technique is widely used in hospitals for medical diagnosis,
staging of disease or for accurate detection, shape and size of the tumor.
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Figure1.3 shows that a patients head is examined from three plans in a clinical
diagnosis which are axial plane, sagittal plane and coronal plane.
Fig. 1.3 Head Examined in a Clinical Diagnosis [21]
The above figure 1.3 shows that the patients head is examined from three planes in a
clinical diagnosis which are Axial plane, Sagittal Plane, Coronal Plane. Furthermore,
T1-weighted brain MRI Images from various planes are shown below.
Fig. 1.3.1 (a) Axial Plane (b) Sagittal Plane (c) Coronal Plane [21]
The above figure 1.3.1 shows that the patients head is examined from three planes in a
clinical diagnosis which are Axial plane, Sagittal Plane, Coronal Plane.
Generally, T scan or MRI that is directed into intracranial cavity produces a complete
image of brain. This image is visually examined by the physician for detection and
diagnosis of brain tumor. However this method of detection resists the accurate
determination of stage & size of tumor. To avoid that, this project uses computer aided
method for segmentation (detection) of brain tumor based on the combination of two
algorithms. This method allows the segmentation of tumor tissue with accuracy and
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reproducibility comparable to manual segmentation. In addition, it also reduces the time
for analysis. At the end of the process the tumor is extracted from the MRI Image and
its exact position and the shape also determined. The stage of the tumor is displayed
based on the amount of area calculated from the cluster.
1.4 The Image Segmentation
In computer vision, image segmentation is the process of partitioning a digital image
into multiple segments (sets of pixels, also known as super pixels). The goal
of segmentation is to simplify and/or change the representation of an image into
something that is more meaningful and easier to analyze. Segmentation is typically used
to locate objects and boundaries (lines, curves, etc.) in images. More precisely, image
segmentation is the process of assigning a label to every pixel in an image such that
pixels with the same label share certain characteristics. The result of image
segmentation is a set of segments that collectively cover the entire image, or a set of
contours extracted from the image (see edge detection). Each of the pixels in a region is
similar with respect to some characteristic or computed property, such as color,
intensity, or texture. Adjacent regions are significantly different with respect to the same
characteristic. When applied to a stack of images, typical in medical imaging, the
resulting contours after image segmentation can be used to create 3D reconstructions
with the help of interpolation algorithms. This is typically used to identify objects or
other relevant information in digital images.
The purpose of segmentation is to separate image information into clear meaningful
parts by placing boundaries separating the area of the healthy brain from the area of the
cancerous and tumorous brain. The objective of image segmentation is to cluster pixels
into prominent image region. Segmentation must not allow regions of the image to
overlap. Image segmentation can be classified into three categories: spatial clustering,
split and merge schemes, and region growing schemes.
1.5 Application of Image Segmentation
There are various applications of the image segmentation that are described below:
1.5.1 Content Based Image Retrieval: Content-Based Image Retrieval (CBIR), also
known as Query. By Image Content (QBIC) and Content-Based Visual Information
Retrieval (CBVIR) is the application of computer vision techniques to the image
retrieval problem, that is, the problem of searching for digital images in large databases.
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Content-based means that the search analyzes the contents of the image rather than
the metadata such as keywords, tags, or descriptions associated with the image. The
term content in this context might refer to colors, shapes, textures, or any other
information that can be derived from the image itself. CBIR is desirable because
searches that rely purely on metadata are dependent on annotation quality and
completeness.
1.5.2 Machine Vision: Machine Vision (MV) is the technology and methods used to
provide imaging-based automatic inspection and analysis for such applications as
automatic inspection, process control, and robot guidance in industry.
1.5.3 Medical Imaging: Medical imaging is the technique and process of creating
visual representations of the interior of a body for clinical analysis and medical
intervention. Medical imaging seeks to reveal internal structures hidden by the skin and
bones, as well as to diagnose and treat disease. Medical imaging also establishes a
database of normal anatomy and physiology to make it possible to identify
abnormalities. Although imaging of removed organs and tissues can be performed for
medical reasons, such procedures are usually considered part of pathology instead of
medical imaging. Locate tumors and other pathologies.
Measure tissue volumes
Diagnosis, study of anatomical structure
Surgery planning
Virtual surgery simulation
Intra-surgery navigation
1.5.4 Object Detection: Object detection is a computer technology related to computer
vision and image processing that deals with detecting instances of semantic objects of a
certain class (such as humans, buildings, or cars) in digital images and videos. Well-
researched domains of object detection include face detection and pedestrian detection.
Object detection has applications in many areas of computer vision, including image
retrieval and video surveillance.
Pedestrian detection
Face detection
Brake light detection
Locate objects in satellite images (roads, forest, crops, etc.)
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1.6 Introduction to Brain Tumor Segmentation
Brain Tumor Segmentation is the process of partitioning a digital image into multiple
segments (sets of pixels, also known as super pixels). The goal of segmentation is to
simplify and/or change the representation of an image into something that is more
meaningful and easier to analyze. Image segmentation is typically used to locate objects
and boundaries (lines, curves, etc.) in images. More precisely, image segmentation is
the process of assigning a label to every pixel in an image such that pixels with the same
label share certain characteristics. Segmentation may also depend on various features
that are contained in the image. It may be either color or texture. Before de-noising an
image, it is segmented to recover the original image. The main motto of segmentation is
to reduce the information for easy analysis. Segmentation is also useful in Image
Analysis and Image Compression. In order to investigate and present the image
segmentation, different entropy measures for threshold selection purpose is used.
1.7 Difficulties in Segmentation of Brain MRI
Cortical segmentation has not been made fully automated and operated at high speed
because of the reliability of the MRI with regards to the homogeneity of its magnetic
field. The problems of MRI include:
1. Noise: random noise connected with MR imaging system. This is known to have
a Rician distribution.
2. Intensity inhomogeneity also called bias field or shading artifact: the non-
uniformity in the radio frequency (RF) field during data collection results in
shading effect.
3. Partial volume effect: In this type of effect more than one type of class or tissue
occupies one pixel or voxel of an image. The pixels or voxels are called mixels.
Segmentation of MRI outputs are normally done by medical experts and requires
processes which consume time. As the images of tumor tissues from different patients
contain many diverse appearance and gray level intensities and frequently look similar
to normal tissues, the process of automation for segmentation of MRI outputs faces
many challenges. One of these challenges is overcome by utilizing prior information
about the appearance of normal brain when performing classification from a multi-
dimensional volumetric features set. This is tantamount to using a statistical model for
tumor and normal tissue of the same feature set.
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1.8 Thresholding
Thresholding is the simplest method of image segmentation. Thresholding is a process
of cinverting a grayscale input image to a bi-level image by using an optimal threshold.
The simplest thresholding methods replace the each pixel in an image with a black pixel
if the image intensity Ii,j is less than some fixed constant T that is, Ii,j
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1.11.3 Entropy Based Methods: It gives the result in algorithms that use the entropy of
the foreground and background regions and the cross-entropy between the original and
binarized image, etc.
1.11.4 Object Attribute -Based Methods: It searches a measure of similarity between
the gray-level and the binarized images, such as fuzzy shape similarity, edge
coincidence, etc.
1.11.5 Spatial Methods: It uses higher-order probability distribution and/or correlation
between pixels.
1.11.6 Local Methods: It adapts the threshold value on each pixel to the local image
characteristics. In these methods, a different T is selected for each pixel in the image.
Now-e-days, speed of computation is no longer an issue for researchers. Therefore, the
focus is directed toward improvement of information from images obtained through the
slice orientation and perfecting the process of segmentation to get an accurate picture of
the brain tumor.
Chapter 2 deals with details of information extracted from research paper related to brain
tumor detection, segmentation, enhancement and feature extraction and its analysis
leading to strengths, weaknesses and gaps in the published research.
Chapter 3 discusses the theoretical aspects of the targeted work and design details of the
technique used by the researchers and also the main approach used in this dissertation.
Chapter 4 elaborates on the proposed system design and its implementation. It includes
details of different tools and techniques and the simulation of the software used. The
architecture description is presented to support the process flow of the work in thesis.
Chapter 5 deals with the experimental results and analysis of the brain tumors through
MRI image segmentation. It also includes the comparison between Shannon and Non-
Shannon entropy measure along with the current comparison with status of the
researcher performance.
Finally, the conclusion is made in chapter 6, summarizing the challenges, proposed
technique and its effectiveness as compared to earlier work.
Next chapter shall discuss about the comprehensive review of the methods and
techniques used to detect brain tumor through MRI image segmentation leading to
problem statement and objective.
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Chapter2: Literature Review
A literature review is necessary to identify a problem and the stages of its solution. A
proper literature review provides a solid background for a noble research work.
Literature survey includes the study of various sources of literature in the area of
research. It includes finding the related material from magazines, books, research
articles, scientific research papers published in various conferences, journals &
transactions. Study and understanding the literature other than scientific research papers
is a bit easy as it elaborates the concepts in simple and explanatory ways. At the same
time these contents cannot be considered as base to arrive at the conclusion of framing
research objectives as it is not supported through proper review by various researchers
working in the area. Review of a scientific research paper is a tedious work. It needs the
prior knowledge of the area of research. The scientific research papers are highly
structured, compact and precise in explanation. The researchers need to adopt a certain
path for doing literature review of such literature. There has been many procedures and
processes defined by the researchers to undergo through and arrive at certain conclusions
of research objectives. The five stages of the review process adopted are discussed in
this chapter. In the literature survey, 31 papers of journals and conferences ranging from
the year 1998 to 2015 and have been reviewed. The categorical review related to the
image segmentation and brain tumor detection has been done. Further including the
gaps in the published research, issue wise solution approaches with common finding,
strengths, weaknesses problem statement and objectives are also presented.
2.1 Review Process Adopted
The process diagram is shown in Fig.2.1, which includes in all five stages. The review
process is divided into five stages in order to make the process simple and adaptable by
every researcher. As it reflects from the literature that while beginning the finding of
research objectives, it is necessary to start with a broader domain of any area and
subarea of interest and narrow down to the specific issue, the process described in the
diagram includes the narrowing down along with the research objectives as outcome
with justification of the problem.
2.1.1 Stages of Review Process
Stage 0: Get the Feel.
Stage 1: Get Big Picture.
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Poornima University, Jaipur M. Tech. (CE) Page 12
Stage 2: Get the Details.
Stage 3: Evaluate the Details.
Stage 3+:Synthesize the Details.
Fig. 2.1 Review Process Stage Analysis
The details of various stages followed are discussed below.
2.1.1 Stage 0: Get a
This stage is the beginning of the literature review process where in one has to broadly
select the area of interest and start searching the scientific research papers from valid
sources. More than 70 papers have been passed through this process. The whole
dissertation concept is related only on the image segmentation, image enhancement and
brain tumor detection and the algorithms that were developed on brain tumor
segmentation.
2.1.3 Stage 1:Get the
In order to understand the paper broadly and get an idea whether the paper exactly
belongs to the research area or subareas elected or it deviates, if deviates how much,
these concepts are made clear this stage, known as Get Big Picture. In this stage the
author knowing about the problem which was the author's attempt to solve. The solution
value and the knowing result are telling about the criteria of the technique was having. In
that step the various types of brain tumor detection techniques, image enhancement and
image segmentation are discussed. After finding the all solution approaches it was found
that the speed of computation is no longer an issue for researchers and the focus is
directed towards improvement of information from image obtained through the accurate
picture of brain tumor. Total 33 research papers could be selected through applying this
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An Efficient Brain Tumor Extraction from MRI Images using Entropy Measures 2014-15
Poornima University, Jaipur M. Tech. (CE) Page 13
process on more than 70 papers.
2.1.3Stage2: Get the
Stage2 deals with going in depth of each research paper and understand the details of the
methodology used, problem justification to significance & novelty of the
problem/solution approach exist, precise question addressed, key contribution, scope &
limitations of the work presented.
After reading all the paper related to the tumor detection, image segmentation it was
found that the many papers are totally focused on the noise reduction technique, some
papers are related to segmentation to get an accurate picture, automation of brain tumor,
computation process, decision making technique. By using accurate diagnosis of brain
tumor, proper brain segmentation is required to be used to carry out an improved
diagnosis and treatment.
2.1.4
This stage provides an insight how to deal with evaluation of the details presented by
the researchers. In the beginning, it is not possible to evaluate these details, as it needs
to check in relative and comparative aspects in the domain of topic. This stage
evaluates the details in relation to the significance of the problem, novelty of the
problem, significance of the solution, novelty in approach, validity of claims, etc.
Here the detail about the detecting brain tumor through Magnetic Resonance Images
has been explored and comparative study has been carried out.
2.1.5 Stage 3+: the
Stage3+ deals deals with synthesis of the data, concept & the results presented by the
authors. This stage does not only require the understanding of all research work related
to the topic, but also requires creative thinking and good knowledge in the subarea of
research. Here all possible situations in general needed to be considered while
generalizing.
The brain tumor detection required image segmentation through MRI, to produce
images of soft tissues of human body. For this purpose, the brain is partitioned into two
distinct regions. This is considered to be the most important but difficult part of the
process of detecting brain tumors. A variety of algorithms were developed for
segmentation of MRI images by using different tools and techniques. However here
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Poornima University, Jaipur M. Tech. (CE) Page 14
presents the detection through the entropy measures and then the analysis on the basis
that which will provide the best result.
2.2 An efficient Brain Tumor extraction from MRI Images using Entropy Measures
After an exhaustive literature review, there have been different types of approaches for
solving the power problems in the circuit. Total 53 papers were reviewed belonging to
conference, journal and transaction publications ranging from year 2001 to 2014. All the
papers were related to single issue of Brain Tumor Detection.
Table 2.2 Categorical Review of Research Papers
S.NO. Name of Issue Total Paper
Reviewed
Number of Paper Reviewed
Conf. Journal Transaction
1 Image restoration 8 8 - -
2 Enhancement of
image
13 13 - -
3 Brain Tumor
detection from MRI
image
32 26 1 5
An efficient Brain Tumor extraction from MRI
Images using Entropy Measures
Most of the papers were centered on a particular issue that was preserving the original
colors indifferent segments of the original image. The approach for color image
segmentation, which approximately preserves the colors in different segments, was
presented through various mechanisms for different entropy measures. The summaries
of the review are shown below.
[M. Stella Atkins, et-al, 1998] has developed a robust fully automatic method for
segmenting the brain from head magnetic resonance (MR) images, which works even in
the presence of radio frequency (RF) inhomogeneities. This method used an integrated
approach which employs image processing techniques based on anisotropic filters and
contouring techniques. The algorithm consists of three incremental steps. The first step
used histogram analysis to localize the head, providing a region which must completely
surround the brain. The second step used nonlinear anisotropic diffusion and automatic
thresholding to create a mask that isolates the brain within the detected head region.
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Using the mask as a seed, the final step employs an active contour model algorithm to
detect the intracranial boundary. It was the multistage process, involving first removal
of the background noise leaving a head mask, then finding a rough outline of the brain,
then refinement of the rough brain outline to a final mask [4].
[C.C. Leung, et-al, 2003] has proposed a new approach to detect the boundary of brain
tumor based on the generalized fuzzy operator (GFO). The GFO map all the pixels in
the original image and all the values were passed to the new fuzzy set. The non-
homogeneities density tissue of the brain with tumor could result in achieving the
inaccurate location in any boundary detection algorithms. In MRI images the Boundary
detection with brain tumor was an important image processing technique. It was a
simple but effective method using in boundary detection. The special properties of this
GFO searched the boundary in high accuracy and obtained the fine edge based on its
generalized fuzzy set. The fuzzy sets separate the edge, normal tissue and tumor
respectively [16].
[M. Sasikalal, et-al, 2005] has proposed a computer based system for the detection of
glioblastoma multiform in brain images and compared feature selection algorithms for
the detection of glioblastoma multiform in brain images. Texture features were
extracted from normal and tumor regions (ROI) using spatial gray level dependence
method and wavelet transform. A very difficult problem in classification techniques was
the choice of features to distinguish between classes. The feature optimization problem
was addressed using a Genetic Algorithm (GA) as a search method. Principal
component analysis, classical sequential methods and floating search algorithm were
compared against the genetic approach in terms of the best recognition rate achieved.
The normal and tumor images were classified with an accuracy of97.3% using the entire
feature set [22].
[Phooi Yee Lau, et-al, 2005] has proposed an analytical method to detect tumors in
digitized medical images for 3D visualization. The EGH parameters were used in a
supervised block of input images. These feature blocks were compared with
standardized parameters (derived from normal template block) to detect abnormal
occurrences, e.g. image block which contain lesions or tumor cells. The abnormal
blocks were transformed into three-dimension space for visualization and studies of
robustness. Experiments were performed on different brain disease based on single and
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multiple slices of the MRI dataset. The method was effectively capable of identifying
tumor areas in T2-weighted medical brain images taken under different clinical
circumstances and technical conditions, which were able to show a high deviation that
clearly indicated abnormalities in areas with brain disease [19].
[Satish Chandra, et-al, 2009] has proposed a modified version of PSO based algorithm
for the classification of MRI images. The algorithm finds the centroids of number of
clusters, where each cluster groups together brain tumor patterns, obtained from MRI
Images. The results obtained for three performance measures were compared with those
obtained from Support Vector Machine (SVM). The performance analysis shows that
qualitative results obtained from the proposed model were comparable with those
obtained by SVM. However, in order to obtain better results from the proposed
algorithm it was needed to carefully select the different values of PSO control
parameters [5].
[Tao Wang, et-al, 2009] has proposed a new approach called the fluid vector flow
(FVF) active contour model to address problems of insufficient capture range and poor
convergence for concavities. With the ability to capture a large range and extract
concave shapes, FVF demonstrates improvements over techniques like gradient vector
flow, boundary vector flow, and magnetostatic active contour on three sets of
experiments: synthetic images, pediatric head MRI Images, and brain tumor MRI
images from the internet brain segmentation repository. Experiment on synthetic images
and head MRI images shown that FVF approach had produced better results.
Quantitative experiments on brain tumor images presented that FVF has the largest
mean (0.61) and median (0.60) with smallest standard deviation (0.05) using TM.
Mixed effects model with random data and test effects was used to statistically compare
the differences between FVF and other methods [27].
[M. Murugesan, et-al, 2009] has proposed an automated system for efficient detection
of brain tumor in EEG signals using Artificial Neural Networks (ANNs). The proposed
system had taken an EEG signal with artifacts as input. Firstly, the inputted EEG signal
was subjected to artifacts removal by means of wiener filtering. Then, features of
interest for brain tumor detection were extracted from the EEG signal. EEG signal were
extracted using spectral estimation. Specifically, spectral analysis was achieved by
using Fast Fourier Transform that extracted the signal features buried in a wide band of
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noise. The clean EEG data thus obtained was used as training input to the feed forward
back propagation neural network. The trained feed forward back propagation neural
network when fed with a test EEG signal, effectively detected the presence of brain
tumor in the EEG signal. The experimental results demonstrated the effectiveness of the
proposed system in artifacts removal and brain tumor detection [17].
[Ahmed Kharrat, et-al, 2009] has proposed an efficient detection of brain tumor based
on mathematical morphology, wavelet transform and K-means technique. The method is
composed of three steps: enhancement, segmentation and classification. The algorithm
reduces the extraction steps through enhancing the contrast in tumor image by
processing the mathematical morphology. The segmentation and the localization of
suspicious regions were performed by applying the wavelet transforms. To improve the
quality of images and limit the risk of distinct regions fusion in the segmentation phase
an enhancement process was applied. A mathematical morphology was adopted to
increase the contrast in MRI images. Then Wavelet Transform in the segmentation
process was applied to decompose MRI images. At last, the k-means algorithm was
implemented to extract the suspicious regions or tumors [13].
[T.Logeswari, et-al, 2010] has proposed a segmentation method for detection of brain
tumor consisting of two phases. In the first phase, the MRI brain image was acquired
from patients database, In that film artifact and noise were removed. After that
Hierarchical Self Organizing Map (HSOM) was applied for image segmentation. The
HSOM was the extension of the conventional self-organizing map used to classify the
image row by row. In this lowest level of weight vector, a higher value of tumor pixels,
computation speed was achieved by the HSOM with vector quantization [15].
[Somojit Saha, et-al, 2010] has proposed an automated segmentation algorithm of the
head contour and the entire brain. The approach used a high resolution MR image
acquisition protocol for better visualization of normal gray structures of brain. Using
signal nulling effect the author has emphasized enhancing the intensity difference
between white and gray matters in the reconstructed MR image. This leads to the
generation of a histogram where pixel values of different anatomical structures were
distributed around separate dominant modes. The algorithm has been tested on 24
dataset of coronal view with great success and validated by a robust index with highly
encouraging outcome. For validation study, some slices were selected such that the
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entire range of the image volume from anterior to posterior was covered. A domain
expert traced the target manually on each slice and it was compared with the
automatically drawn head and brain contour using the similarity index [21].
[D.K. Somwanshi, et-al, 2011] has proposed a method that provides complete
diagnosis of the internal structure of the body and even detects the smallest
abnormalities through MRI scanned images. The method introduced was the image
processing based method that performed the texture feature of MRI image and
segmentation has been done. Texture analysis of the 5 different images of each case is
done by finding their contrast, correlation, energy, homogeneity and entropy, and then
their range is obtained. In order to detect the presence of the abnormality in the image,
its texture analysis of both the normal and abnormal images were done. On the basis of
the values of abnormal image, the range was calculated and further the texture feature of
normal image was compared and the feature lying outside the range finally detects the
abnormality in the biomedical image [26].
[V. Salai Selvam, et-al, 2011] has proposed a Scalp EEG with modified Wavelet-ICA
and Multi-Layer Feed Forward Neural Network for Brain Tumor Detection. Use of
scalp EEG for the diagnosis of various cerebral disorders is progressively increased.
The chosen EEG epoch belonged to a brain tumor case was considered as positive and
that it belonged to a normal case as negative. Then the four possibilities of the network
outcomes were True Positive (TP) if the network decided that a chosen EEG belonged
to a brain tumor case when it actually did, True Negative (TN) if the network decided
that a chosen EEG belonged to a normal case when it actually did, False Positive (FP) if
the network decided that a chosen EEG belonged to a brain tumor case when it actually
belonged to a normal case and False Negative (FN) if the network decided that a chosen
EEG belonged to a normal case when it actually belonged to a brain tumor case. From
the ROC it was clear that the performance of the proposed method in detecting the brain
tumor using the scalp EEG was very much encouraging [22].
[V.P. Gladis, et-al, 2011] has proposed method to segment a human brain of MRI
image in which tumor detection and characterization were considered using HSOM and
Wavelet packets feature spaces. In the first phase, the MRI brain image was acquired
from patients database, In that film artifact and noise were removed, and Hierarchical
Self Organizing Map (HSOM) was applied for image segmentation. The HSOM was the
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extension of the conventional self-organizing map used to classify the image row by
row. In the second phase, the feature of the MRI image was extracted first. Therefore,
the proposed method has the potential to non-invasively determine the type of the brain
tumor [9].
[M. Usman Akram, et-al, 2011] has proposed a method for automatic brain tumor
diagnostic system from MRI images. The system consists of three stages to detect and
segment a brain tumor. In the first stage, MRI image of brain was acquired and
preprocessing was done to remove the noise and to sharpen the image. In the second
stage, global threshold segmentation was done on the sharpened image to segment the
brain tumor. In the third stage, the segmented image was post processed by
morphological operations and tumor masking in order to remove the false segmented
pixels. The proposed method enhanced the MRI image and segments the tumor using
global thresholding. False segmented pixels were removed using morphological
operations. The proposed method was invariant in terms of size, shape and intensity of
brain tumor. Experimental results show that the method performed provided the 92%
accuracy in enhancing, segmenting and extracting the brain tumor from MRI images
[14].
[Wang Yang, et-al, 2011] has proposed a Contour-based and Region Based methods
for segmenting brain tumors in 3D magnetic resonance images. This method was
applicable to different types of tumor. It takes the advantage of Fuzzy Classification for
automating the algorithm and the good quality segmentation result of deformable
models to improve the segmentation. This was achieved by IKFCM classification
method, morphological operation and a parametric 3D deformable model First the brain
was segmented using a new approach, robust to the presence of Tumors. Then a Tumor
detection was performed, based on improved Fuzzy classification. Applications on
several data sets with different Tumor sizes and different locations show that the
method works automatically with high quality of segmentation and were robust to inter-
individual variability for all types of fully enhancing Tumors [29].
[K. S. Angel Viji, et-al, 2011] has developed a brain tumor segmentation method and
validated using MRI Data. In Preprocessing and Enhancement stage, medical image was
converted into standard formatted image. Segmentation subdivides an image into its
constituent regions or objects. This method can segment a tumor provided that the
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desired parameters are set properly. The author focuses on the computation of steepest
slope lines, and produces zero width watersheds. Also, this method has a high degree of
locality that it was suitable for parallel implementation. In this, after a manual
segmentation procedure the tumor identification, the investigations has been made for
the potential use of MRI data for improving brain tumor shape approximation and 2D &
3D visualization for surgical planning and assessing tumor [18].
[K.K. Sharma, et-al, 2012] has proposed a threshold selection technique for color
image segmentation problem, which approximately preserves the colors in different
segments. The threshold values obtained are dependent on the particular definition of
the entropy chosen, which in turn affects the segmentation results. In the proposed
approach, threshold selection in each of the three component (RGB) images is done on
the basis of different entropy measures. It was further observed that the segmentation
results obtained using Havrda-Charvat entropy measures were better than other entropy
measures in the sense of preservation of colors in different segments [12].
[Rupsa Bhattacharjee, et-al, 2012]has proposed a novel algorithm to feature out tumor
from diseased brain Magnetic Resonance (MR) images. In this work, based on a study
of quality parameter comparison of two filters, adaptive median filter was selected for
de-noising the images. Image slicing and identification of significant planes were done.
Logical operations were applied on selected slices to obtain the processed image
showing the tumor region. A novel image reconstruction algorithm was developed
based on the application of Principal Components Analysis (PCA). This reconstruction
algorithm was applied on original raw images as well as on the processed images.
Results of this work confirm the sole efficiency of the developed image processing
algorithm to detect brain tumor [9].
[Azian Azamimi Abdullah , et-al, 2012] has proposed a brain tumor detection method
based on cellular neural networks (CNNs). CNN was widely used for image processing,
pattern, target classification, motion detection and signal processing. To examine the
location of tumor in the brain, Magnetic Resonance Imaging (MRI) was used.
Radiologists evaluated the grey scale MRI images. This procedure was really time and
energy consuming. To overcome this problem, an automated detection method for brain
tumor using CNN was developed. The output of the images was the image segmentation
based on black and white. Black represented as normal area and the white area
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represented as tumor area. By using the template in the CNN simulator, output of the
desired image could be performed. Therefore, many templates were combined in order
to obtain an accurate result that will help radiologists detecting the tumor in brain
images easily [3].
[Sahar Ghanavati, et-al, 2012] has proposed an automatic tumor detection algorithm
using multi-modal MRI. A multi-modality framework for automatic tumor detection
was presented, fusing different Magnetic Resonance Imaging modalities including T1-
weighted, T2-weighted and T1 with gadolinium contrast agent. The intensity, shape
deformation, symmetry, and texture features were extracted from each image. The
AdaBoost classifier was used to select the most discriminative features and to segment
the tumor region. Multi-modal MRI Images with simulated tumor was used as the
ground truth for training and validation of the detection method. The results on
simulated and patient MRI show 100% successful Tumor detection with average
accuracy of 90.11% [10].
[Sarah Parisot, et-al, 2012] has proposed a novel approach for detection segmentation
and characterization of brain tumors. In this the author combines an image-based
detections schema with identification of the tumors corresponding preferential location,
which was associated to a specific spatial behavior. This method exploits prior
knowledge in the form of a sparse graph representing the expected spatial positions of
tumor classes. Such information was coupled with image-based classification
techniques along with spatial smoothness constraints towards producing a reliable
detection map within a unified graphical model formulation. Towards optimal use of
prior knowledge, a two-layer interconnected graph was considered with one layer
corresponding to the low-grade glioma type (characterization) and the second layer to
voxel-based decisions of tumor presence. Efficient linear programming both in terms of
performance as well as in terms of computational load was considered to recover the
lowest potential of the objective function. The outcome of the method refers to both
tumor segmentation as well as their characterization [16].
[Yao Tien Chen, et-al, 2012] has proposed an approach integrating 3D Bayesian level
set method with volume rendering for brain tumor and tissue segmentation and
rendering. A prior probability estimation of the tumor and tissue was incorporated into
3D Bayesian level set method for 3D segmentation. The 3D Bayesian level set method
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was then used to continuously segment the 3D targets from a series of brain images. To
facilitate 3D volume visualization of medical-image dataset, ray casting was conducted
to render the targets and construct the surface of the targets. Experiment results were
finally reported in terms of segmenting, rendering, and surface reconstructing of the
tumor, tissue, and whole brain [12].
[Natarajan P, et-al, 2012] has proposed a morphological processing technique that has
proved miraculously helpful in various image extraction and filtering techniques. The
morphological operators changed the structuring elements of the image according to
their use. Some operators like open, spur, dilate and close had proved helpful in
extracting the brain tumor from the MRI brain images. Pre-processing of the MRI was
done using gray scaling, histogram equalization and filtering techniques. Threshold
segmentation was used to work on the desired region of the image. Thus by applying the
image subtraction could get the final brain tumor image [13].
[Vijayshree Gautam, et-al, 2013] has proposed an approach for threshold selection
purpose in color image segmentation problems. The threshold values obtained were
dependent on the particular definition of the entropy chosen, which in turn affects the
segmentation results. It was further observed that the segmentation results obtained
using Havrda-Charvat entropy measures are better than other entropy measures in the
sense of preservation of colors in different segments. Simulation results performed in
MATLAB. The entropy function versus individual RGB component level plot is
obtained for Shannon and non-Shannon entropy measures. A typical plot for entropy
function using Havrda-Charvat entropy measure was done [18].
[Pavel Dvorak, et-al, 2013] has proposed a method for the detection of images
containing an abnormality caused by tumor. The goal was to determine whether the
MRI Image of a brain contains a tumor. The proposed method works with T2-weighted
magnetic resonance images, where the head was vertically aligned. The detection was
based on checking the left-right symmetry of the brain, which was the assumption for
healthy brain. The algorithm was tested by five-fold cross validation technique on 72
images of brain containing Tumors and 131 images of healthy brain. The proposed
method reached the true positive rate of 91.16% [7].
[T.Rajesh, et-al, 2013] has proposed an automated system for classification of MRI
brain images with different pathological condition. Many cancer forms can only be
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diagnosed after a sample of suspicious tissue has been removed and tested. Pathologists
view pathologic tissues, typical1y with microscopes, to determine the degree of
normalcy versus disease. This process was time consuming and fatiguing. The system
described here classified the abnormality into benign or malignant in an automated
fashion. The author used conceptual1y simple classification method using Feed Forward
Neural Network. Texture features were calculated using Rough set theory. The
proposed system effectively classified the abnormality of brain tumors [15].
[Atiq Islam, et-al, 2013] has proposed a novel multifractal (multi-FD) feature
extraction and supervised classification techniques for improved brain tumor detection
and segmentation. The multi-FD feature characterizes intricate tumor tissue texture in
brain MRI as a spatially varying multifractal process in brain MRI. On the other hand,
the proposed modified AdaBoost algorithm considers wide variability in texture features
across hundreds of multiple-patient MRI slices for improved tumor and non-tumor
tissue classification. Experimental results with 14 patients involving 309 MRI slices
confirm the efficacy of novel multi-FD feature and modified AdaBoost classifier for
automatic patient independent tumor segmentation. In addition, comparison with other
state-of-the-art brain tumor segmentation techniques with publicly available low-grade
glioma inBRATS2012 dataset presented that the method outperform other methods for
most of the patients. The computation complexity of multi-FD feature was linear and
increased with slice resolution (number of pixel), block size, and the number of wavelet
levels [11].
[J.Vijay, et-al, 2013] has proposed a combine method of segmentation and K-means
clustering that described an efficient method for automatic brain tumor segmentation for
the extraction of tumor tissues from MRI Images. The main argument of the proposed
modifications is on the reduction of intensive distance computation that takes place at
each run (iteration) of K-means algorithm between each data point and all cluster
centers. In this method segmentation was carried out using K-means clustering
algorithm for better performance. This enhances the tumor boundaries more and was
very fast when compared to many other clustering algorithms. The proposed work also
reduces the computational complexity and also provides an accurate method of
extracting the Region of Interest (ROI).The proposed technique produced appreciative
results [27].
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[Woo Kyung Moon, et-al, 2013] has proposed a computer-aided detection (CAD)
system based on multi-scale blob detection for analyzing ABUS images. After speckle
noise reduction, Hessian analysis with multi-scale blob detection was adopted to detect
the lesions by using blobness measurements of ABUS images. Tumor candidate
selection was then applied to remove the redundant non-tumors from the tumor
candidates. The tumor likelihoods of the remaining tumor candidates were estimated
using a logistic regression model with blobness, internal echo, and morphology features.
Finally, the tumor candidates with tumor likelihoods higher than a specific threshold
were considered to be tumors [7].
[Solmaz Abbasi, et-al, 2014] has proposed a method for 3D medical image
segmentation to detect brain tumor in MRI images by combining Clustering and
Classification methods to decrease the complexity of time and memory. The author
presented a hybrid method in which clustering(for obtaining region of interest) and
classification (for region of interest- segmentation) were used. In the first phase, non-
negative matrix factorization with sparseness constraint method was used to separate the
region of interest from the image. In the second phase, the classification of the region of
interest was performed. This method had achieved a fast speed for segmentation of MRI
3D images and evaluated with criteria of Dice's and Jacquard's coefficient on the brain
tumor from magnetic resonance image obtained from the Brats2013 database [2].
[Akram Rashid, et-al, 2014] has proposed a method from Electroencephalogram that
eliminate the noise of power line, noise of human body muscles, noise of human lungs
and noise of the base line. In this the basic important algorithms used were Kalman
filter. The Electroencephalogram signals were highly contaminated with various
artifacts both from subject and from equipment interferences. For efficient detection of
tumor artifacts exist in the electroencephalogram signal were removed using analogue
filtering. After than the Fast Independent Component Analysis algorithm was used to
separate the noise and get the features which were buried in the extended band of noise.
For problem solution a unique Fast Independent Component Analysis filter was being
proposed [12].
[Parveen, et-al, 2015] has proposed a new hybrid technique based on the support vector
machine (SVM) and fuzzy c-means for brain tumor classification. In this technique the
image was enhanced using enhancement technique such as contrast improvement, and
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mid-range stretch. The brain MRI images were classified using SVM techniques which
were widely used for data analyzing and pattern recognizing. It creates a hyper plane in
between data sets to indicate which class it belongs to. Double thresholding and
morphological operations were used for skull striping. Fuzzy c-means (FCM) clustering
was used for the segmentation of the image to detect the suspicious region in brain MRI
image. The main objective of this work was to develop a hybrid technique, which can
classify the brain MRI images successfully and efficiently via Fuzzy C- means and
support vector machine (SVM) [18].
[ Padmakant Dhage, et-al, 2015 ] has developed a technique to solve the problem for
tumor case of clinical MRI analysis. The proposed technique was based on Watershed
segmentation and it has been successfully tested on MRI image data. Developed
algorithm was used to know about the location and size of the tumor. The author
illustrates the ability of watershed segmentation to separate the abnormal tissue from the
normal surrounding tissue to get a real identification of involved and noninvolved area
that help the surgeon to distinguish the involved area precisely. At the end of the
process tumor was extracted from the MRI Image and its exact position and shape was
determined and various parameters like perimeter, eccentricity, entropy and centroid
was calculated. All parameters which were extracted using developed algorithm specify
the size and other dimensions of the tumor [8].
2.2.2 Common Findings obtained in the issue Brain Tumor Detection from MRI
Images
In the contour deformable model with regional base technique, the performance
was insufficient to obtain the fine edge in the tumor.
The efficient system was presented to perform early detection of brain Tumors
from EEG Signals with the aid of Artificial Neural Networks.
The feed forward back propagation neural networks provide computationally
more efficient Detection Accuracy with 98.7654% once trained.
Feature selection algorithms were categorized into Exponential, Randomized
and Sequential algorithms to attain high accuracies.
The Genetic Algorithm based Global Search was used for selecting the best set
of features.
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The classification of normal and tumor regions was done using texture features
from gray level dependence method (SGLDM) and wavelet features.
To improve the quality of images and limit the risk of distinct regions fusion in
the segmentation phase an enhancement process was applied on brain images to
increase the contrast in MRI images and to extract the suspicious regions or
tumors.
The segmentation and the localization of suspicious regions were performed by
applying the wavelet transforms.
The HSOM was the extension of the conventional self-organizing map used to
classify the image row by row.
A mathematical morphology was adopted to increase the contrast in MRI
images.
The Hybrid algorithm used Contour-based and Region based Methods to
segment Brain Tumors in 3D MRI Images.
The HSOM and Wavelet packets feature spaces method have the potential to
non-invasively determine the type of the brain tumor
Multi -modal MRI Images with simulated tumor were used as the ground truth
for training and validation of the detection method.
The performance of clustering algorithm for image segmentation was highly
sensitive to features that were used and the types of objects in the image and
hence generalization of this technique was difficult.
2.3 Various solution approaches in
from
The Conceptual explanation of various solution approach and algorithms used are
summarized in the table below. This section would include, the issue-wise solution
approaches, methodologies used by the researchers, with results obtained. Based on
Shannon Algorithm different authors have used different data that is presented below:
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Table 2.3: Categorical Review of Research Paper
Author Solution
Approach
Input
Parameters
Accuracy
(%) Performance Parameters Results
[C.C. Leung, et-al, 2003]
Generalised
Fuzzy Operator
(GFO)
MRI Images 98
Comparison with CDM and modified GFO(mGFO)
Accurately search the boundary of the Brain Tumor.
Real edge CDM mGFO
Total no. of
pixels within
tumor
1749 2443 1783
Number of
mismatch pixels
out of tumor
1749 (1689)
+694 (41.09%) +34 (2.01%)
Number of
mismatch pixels
inner of tumor
1749
(60) -60 (100%) -4 (6.67%)
[Ahmed Kharrat, et-
al, 2009]
Mathematic
Morphology MRI Images 87
MRI Image CLAHE Beghadi Mathematic
Morphology The extraction of the tumor was accomplished
manually from segmentation result and it was
observed that Mathematical Morphology was better. Abnormal Image 0.8172 0.9997 1.5073
[M. Stella Atkins,et-al,1998]
Automatic intracranial
boundary
detection algorithm
MRI data sets
96
Comparision of Manual and Automatic Brain Segmentation
The algorithm has proven effective on clinical and
research MRI data sets acquired from several
different scanners
Slice No. Manual Area Auto Area Similarity
Index
4 8912 10269 0.925
7 20264 22472 0.929
8 22035 23918 0.954
23 20109 20341 0.980
24 15909 17201 0.958
[PadmakantDhage,
et-al, 2015]
Watershed
Segmentation
MRI Images
97.3
S.No. Parameter Median Filter Bilateral Filter
Accurately remove the noise from MRI Images
without disturbing the edges.
1 MSE 2.98 4.05
2 PSNR 43.3 42.0
3 Contrast 0.10 0.01
4 Corelation 0.99 0.99
[SolmazAbbasi, et-al,
2014]
Combined Clustering and
classification
Mechanism
3D Medical
Image
N/A
Dice
Complte
Tumor
Dice
Tumor
Core
Dice
Enhancing
Tumor
Jaccard
Complete
tumor
Jaccard
Tumor
Core
Jaccard
Enhancing
Tumor This method decreases the computational complexity in
time and memory. 0.8497 0.7902 0.7941 0.7467 0.6678 0.6884
[AzianAzamimi
Abdullah, et-al,
2012]
Cellular Neural
Networks
(CNN)
MRI Images N/A N/A
The output of the image detected in shorter time and based
on black and white. Black portion represented as normal
area and white are represented as tumor area.
[SaharGhanavati, et-
al, 2012]
Multi -Modality
Framework
T1 and T2
weighted Magnetic
Resonance
Imaging
90.11
Cases Accuracy Specificity
The better segmentation at the edges of tumor was obtained. Case1 90.11% 92.26%
Case2 89.12% 91.19%
[Wang Yang, et-
al,2011]
Hybrid
Algorithm
3D
Magnetic
True Detection
Tp = NTP/NM*100%
The average computation time for detection of tumor was
reduced.
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(Contour based
and region based)
Resonance
Images
N/A False Detection
Fp=NFP/NA*100%
Tumor Type Method TP %
FP %
FE1 FPCM 82 1.92
FE1 IKFCM 93 7.63
FE2 FPCM 93 9.57
FE2 IKFCM 98 4.40
[Satish Chandra, et-
al,2009]
Clustering
Algorithm
based on
PSO
110
abnormal and 62
normal axial
MRI images
92.41
Results for various Algorithm
Performance is improved in terms of execution time and
tumor pixel detected.
Classifier Precision Recall Accuracy
Proposed PSO
Based algorithm 92.76 96.24 94.42
SVM (Polynomial
kernel) 93.33 95.28 92.71
AdaBoost 90.25 91.66 89.31
[T.Logeswari, et-al,
2010]
Hierarchical
Self
Organizing Map
MRI Data N/A
neighborhood
pixel
Winning
neuron
Number
of seg
pixel
Exe-time weight
The target area is
segmented and Brain Tumor detection done accurately 3x3 209 795 13.76 14
5x5 201 1073 14.96 8
7x7 194 1285 15.20 15
9x9 186 1594 11.05 23
11x11 177 1881 11.53 32
[M. Murugesan, et-
al, 2009]
Artificial Neural
Network
325 samples of EEG
data.
98.7654 325 Samples of EEG
Data
Detection Accuracy The trained Feed forward back propagation neural network
has detected the presence of brain tumor in the test signal. Normal 94.4785
Abnormal 98.7654
[V. SalaiSelvam, et-
al, 2011]
Scalp EEG
withModified Wavelet-ICA
MRI and
CT-SCAN Data
N/A
Sensitivity or TPR 0.930
Improved the detection rate of the Tumor.
FPR 0.106
Accuracy 0.918
Specificity or TNR 0.894
[RupsaBhattacharjee,
et-al, 2012]
PCA Based
Reconstruction MRI Images N/A
Noise Details Filters Comparision
Abnormal area of the brain is detected and pixel wise
intensity is calculated.
Parameter Bilaterl Filter Adaptive
Noise Density
MSE 8242.5 1590.2
PSNR 8.9702 16.1163
UIQI 0.0742 0.4306
Guassian
Noise
MSE 1271.4 424.1774
PSNR 17.0879 21.8553
UIQI 0.1894 0.2520
[M. Usman Akram, et-al, 2011]
Global thresholding
100 MRI
Images
97
Parameter Value
The proposed method performs well in enhancing,
segmenting and extracting the brain tumor from MR images.
Standard Deviation 0.0013
Accurately Segmented 97%
Poorly Segmented 3%
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[Woo Kyung Moon, et-al, 2013]
Multi -Scale
Blob Detection
Algorithm
ABUS image
97
Feature Set False Positive FOM
Successfully detected the abnormalities with tumor region.
Blobness 113.26 0.28
Internal Echo 42.04 0.23
Morphology 65.16 0.16
Blobness and
Internal Echo 39.81 0.33
Blobness and
Morphology 61.08 0.36
Internal Echo and
Morphology 37.81 0.43
All features with
IOF-CV 17.33 0.47
All features with
LOO-CV 17.45 0.47
[Natarajan P, et-al, 2012]
Threshold operation
MRI Brain Images
N/A
RGB 1. For black
R = G = B = 00000000
2. For white R = G =B = 11111111
Tumor is identified from the MRI Image accurately.
[T.Rajesh, et-al,
2013]
Feed Forward
Neural Network
MRI Brain
Images 90
Evaluation
Metrices Training Dataset
Proposed Testing
Dataset
Suspicious tissues are tested and many cancer forms are
diagnosed.
(TN)True Negative 9 10
(FP)False Positive 1 0
(TP)True Positive 10 8
(FN)False Negative 0 1
Specificity 0.9 1
Sensitivity 1 0.88
Accuracy 0.95 0.9
[M. Sasikala, et-al, 2005]
Artificial
Neural
Network
19 scans of
glioblastoma multiforme
and 18 scans
containing normal brain
images
97.3%
Feature Selection
Algorithm Feature Set
Classifier
Accuracy
The normal and tumor images are classified with an accuracy of 97.3%
SFS ASM, IDM, SVAR,
SENT 97.3%
SBS SVAR,ENT,
ENERGY, MEAN 97.3%
Plus 1- take away r
method
ASM, SVAR, IMC,
ENERGY, 97.3%
SFFS ASM, SVAR, SENT,
DENT 97.3%
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Table 2.4: Comparison Table of different Entropy
Author Solution
Approach
Data used Performance Measures
(Threshold Value) Results
[Shruti
Mathur, et-al,
2014]
Shannon and non-
Shannon Entropy
jpg image
Entropy Kaju.jpg Algae.jpg America.jpg Havrda-Charvat entropy based image
segmentation technique is better for gray
images than any other entropy measures.
Shannon 10 83 197
Kapur 26 140 211
Vajda 5 141 209
Renyi 122 140 211
Havrda 83 113 161
[Vijayshree
Gautam, et-al,
2013]
Shannon and Non-
shannon Entropy
Color Image
Entropy Component Various individual RGB component
level plot is obtained for Shannon and
non-Shannon entropy measures.
R G B
Havrda-Charvat
Entropy
124 42 55
Shannon Entropy 17 39 106
Renyi Entropy 234 15 39
[Ahmad Adel
Abu Shareha,
et-al, 2008]
Renyis entropy Synthetic
Images Image No. Threshold using the
original Entropy
Threshold using
Textured Renyi
The experimental results show that the
proposed method enhances the
thresholding result and reduce the error
rate. 1 T=187 T=177
2 T=155 T=86
3 T=55 T=55
4 T=154 T=74
5 T=153 T=149
6 T=133 T= 133
7 T=178 T= 172
8 T=157 T= 154
[Siddheswar
Roy, et-al,
2000]
Shannon Entropy Three images
( balls,
molecule, rose)
Entropy
Function
Entropy
type
Balls Molecule Rose The experimental results was quite
satisfactory.
Shannon Global 369.7350 194.3193 180.9309
Shannon Local 296.1081 316.2784 204.4700
Shannon Conditional 227.3324 324.0741 219.7089
[K.K. Sharma,
et-al, 2012]
Shannon and Non-
Shannon Entropy
Ball Image Entropy
Component The segmentation results obtained using
Havrda-Charvat entropy measures were
better than any other entropy measures R G B
Kapur 20 23 71
Havrda-
Charvat 117 138 141
Shannon 64 80 198
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An Efficient Brain Tumor Extraction from MRI Images using Entropy Measures 2014-15
Poornima University, Jaipur M. Tech. (CE) Page 31
Renyi 216 215 73
Vajda 10 21 72
[P.K. Saboo,
et-al, 2006]
Havrda-Charvat
Entropy
Tif images
Test Image T(0.3) The images were segmented perfectly
and a histogram was created using the
gray value.
Camaraman.tif 99
Kids.tif 32
Rice.tif 182
Tire.tif 111
Bonemarr.tif 122
Boats.tif 102
Bridge.tif 125
Lena.tif 122
[Amar Pratap
Singh, et-al,
2009]
Shannon and Non-
Shannon Entropy
Measures
Mammogram
Image Analysis
Society
Database
Images
Sample
S
R
HC
K
Results have demonstrated that Havrda
& Charvat entropy based feature for
classifying normal and abnormal
mammogram images. Mam1 4.76 6.92 8.79 7.99
Mam2 5.17 6.90 9.05 7.79
Mam3 5.24 7.01 9.34 7.88
Mam4 5.16 6.71 8.63 7.57
Mam5 4.84 6.78 8.51 7.81
Mam6 5.10 6.79 8.71 7.72
Baljit Singh
Khehra,et-
al,2011
Shannon and non-
shannon Entropy
mini-MIAS
database
(Mammogram
Image Analysis
Society
database
Test Image tS t
R t
HC t
k The result show that it is useful for
radiologists to find suspicious region
in mammogram.
mdb218 180 191 194 193
mdb236 186 200 201 201
mdb238 171 179 178 177
mdb219 185 194 198 198
mdb222 186 193 194 194
mdb227 184 193 194 194
mdb240 198 210 210 210
mdb245 177 198 200 199
mdb248 177 192 193 194
mdb253 191 203 205 205
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2.4 Strengths and weaknesses of research found in the issue Brain Tumor
Extraction from MRI Images using Entropy Measure
After, the review of 32 research papers under the area of Brain Tumor Extraction from
MRI Images, I have been able to find, the strengths and weaknesses of various solution
approaches used to solve the issues discussed in previous chapters. This section would
enlist the strengths and weaknesses of the various methods and algorithms used.
2.4.1Strengths in the area of Brain Tumor Detection from MRI Images:
After, the review of thirty one research papers under the area of Brain Tumor
Extraction from MRI Images strengths and weaknesses of various solution approaches
used could be determined. This section mainly enlists the strengths of the various
methods and algorithms used.
The watershed transformation algorithm extracts shape and form related
information from images precisely [8].
The Vajda entropy measures provide the advantage of faster calculations over
Kapurs entropy measure [17].
Havrda-Charvat entropy based image segmentation technique was better for
gray images than any other entropy measures [12].
The major advantage of split and merge technique that it guaranteed connected
regions [21].
The Mean Shift algorithm provides a robust feature space analysis approach
which can be applied to discontinuity preserving smoothing and image
segmentation problems [6].
The Ncut method was applied directly to the image pixels, which were typically
of very large size [4].
The Ncut method was applied to perform globally optimized clustering and get
the final segmentation result [13].
The Mean Shift algorithm can significantly reduce the number of basic image
entities, and due to the good discontinuity preserving filtering characteristics, the
salient features of the overall image were retained [1].
Edge detection algorithm was used for object detection which serves various
applications like medical image processing, biometrics etc [23].
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Poornima University, Jaipur M. Tech. (CE) Page 33
Thresholding was computationally inexpensive and fast, it was the oldest
segmentation method and was still widely used in simple applications [27].
Global thresholding method selects only one threshold value for the entire image
[3].
Edge preserving denoising was of great concern in medical images. Denoising
was performed to segmentize the image for better diagnosis [11].
2.4.2Weaknesses in the area of Brain Tumor Detection from MRI Images:
By applying the Ncut algorithm the performance and stability of the partitioning
highly depends on the choice of the parameters [19].
The drawbacks of the split and merge technique were, the results depend on the
position and orientation of the image, leads to blocky final segmentation and
regular division leads to over segmentation (more regions) by splitting [12].
If seeded region growing method was used then noise in the image can cause the
seeds to be poorly placed [8].
Local thresholding selects different threshold values for different regions [23].
The performance of clustering algorithm for image segmentation was highly
sensitive to features used and types of objects in the image and hence
generalization of this technique is difficult [15].
Clustering technique doesnt guarantee continuous areas in the image, even if it
does edges of these areas tend to be uneven, this was the major drawback [29].
2.5 Gaps in the published work
The Researcher had presented many techniques and methodologies to segment the MRI
images and to detect the Brain Tumor. All the Researchers had shown some
improvement with some gaps in their work. Those are:
A very few approaches had been made for Early Detection and classification of
Brain Tumors.
There are various approaches that have been proposed to deal with the task of
segmenting and detecting the brain tumors in MRI Images but the performance
of these approaches usually depends on the qualitative amount of information.
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Most of the research work was directed towards the speed of computation that
was no longer an issue nowadays. The improvement of information obtained
from images and perfecting the process of segmentation to get an accurate
picture of the brain tumor must be given importance.
During the acquisition of medical images, there were possibilities that the
medical image one gets might be degraded. Very few works has been done in
order to reduce this problem.
2.5 Problem Statement
Brain Tumor was one of the frequent and leading causes of mortality, especially in
developed countries. Though brain tumor leads to death, early detection can increase the
survival rate. In this dissertation work the main emphasis laid on to design an approach,
which was a detection technique so that the system effectively detects and diagnose the
tumor in their early stage.
Thus the final title of the work chosen to achieve the main aim of early detection of
tumors in MRI Images is An efficient Brain Tumor Extraction from MRI Images
using Entropy Measures.
2.6 Final Objectives
1. To finalize the MRI images for experimentation.
2. To perform the global thresholding image Segmentation on MRI Images
3. To calculate the entropy and to check the threshold of each image in order to find
out the tumor affected region.
4. To compare and analyze the performance of the Shannon and non-Shannon entropy
measures.
So this chapter presents, Performance Evaluation Criteria used by various researchers,
details of Software used by researchers, Methodologies used by Researchers. Next
Chapter will provide the theoretical aspect of targeted work, details of Input/output
parameters that will be used during experimentations and details of softwares which
have been selected to carry out experimentation.
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Chapter 3: Theoretical Aspects of Brain Tumor Extraction from MRI
Images
In previous chapter we have discussed literature review of different problems and
solutions in brain tumor detection. This dissertation focuses on accurate detection of
brain tumor, image segmentation, to minimize diagnostic errors, to improve the
accuracy by using Computer aided diagnostic. Different types of tumor detection
methods and some other techniques in order to get an accurate picture of brain tumor
from images obtained through the slice orientation and perfecting the process of
segmentation are discussed in this chapter.
In day-to-day life, new technologies are emerging in the field of Image processing,
especially in the domain of segmentation. Segmentation is the most important part in
image processing Fence off an entire image into several parts which is something more
meaningful and easier for further process. Segmentation may also depend on various
features that are contained in the image. It may be either color or texture. Before
denoising an image, it is segmented to recover the original image. The main motto of
segmentation is to reduce the information for easy analysis. Segmentation is also useful
in Image Analysis and Image Compression.
3.1 Classification of Image Segmentation
There are several existing techniques which are used for image segmentation. These all
techniques have their own importance.
Fig. 3.1 Image Segmentation Techniques
The popular techniques used for image segmentation are: thresholding method, edge
Image Segmentation
Methods
Threshold Methods
Edge Based Methods
Region Based Methods
Clustering Based Methods
Watershed Based Methods
PDE Based Methods
ANN Based Methods
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detection based techniques, region based techniques, clustering based techniques,
watershed based techniques, partial differential equation based and artificial neural
network based techniques. These all techniques are different from each other with
respect to the method used by these for segmentation.
3.1.1 Thresholding Method
Thresholding methods are the simplest methods for image segmentation. These methods
divide the image pixels with respect to their intensity level. These methods are used
over images having lighter objects than background. The selection of these methods can
be manual or automatic i.e. can be based on prior knowledge or information of image
features. There are basically three types of thresholding.
1. Global Thresholding: This is done by using any appropriate threshold value/T. This
value of T will be constant for whole image.
2. Variable Thresholding: In this type of thresholding, the value of T can vary over the
image. This can further be of two types
Local Threshold: In this the value of T depends upon the neighborhood of x and y.
Adaptive Threshold: The value of T is a function of x and y.
3. Multiple Thresholding: In this type of thresholding, there