Brain Tumor Detection Using Image Processing Techniques

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FIGURE 4.1

Anatomical planes. The MRI dataset that was made available as open source

on Kaggle was used to create this figure [5].

Figure 4.1. The brain is partitioned into anterior (front) and posterior (back)

sections in the coronal plane, and into right and left sections in the sagittal

plane. In the horizontal plane, also referred to as the axial plane, the brain is

divided into superior (upper) and inferior (lower) sections [4].

4.2.2

T1-weighted MRI and T2-weighted MRI

After figuring out the scan’s view, the following step is to determine the im-

age’s weight. Two different scan types—T1-weighted and T2-weighted—can

be created by adjusting the magnetic fields the scanner produces. Time to

echo (TE) and repetition time (TR) are two fundamental time parameters in

image acquisition. These serve as key parameters in creating image contrast.

TR is the time interval between consecutive radio frequency (RF) pulse se-

quences applied to the same slice [6]. TE interval occurs between sending out

the RF pulse and receiving the echo signal [6]. A short TE and TR are used

to construct a T1-weighted MRI and long TE and TR are used to construct

a T2-weighted MRI.

T1-weighted scan provides a high anatomical definition in images, whereas

T2-weighted scan is effective in detecting pathology [7]. Cerebro-spinal fluid

is usually examined to distinguish between T1- and T2-weighted scans. It

appears dark on T1-weighted scans and bright on T2-weighted scans [6, 8].

On T1-weighted and T2-weighted scans, tissues containing fat and water can

be easily differentiated [9]. Tissues carrying water and fluid appear darker

on T1-weighted scans whereas they appear brighter on T2-weighted scans

[10]. Conversely, tissues containing fat exhibit the opposite behavior, appear-

ing brighter on T1-weighted scans and darker on T2-weighted scans [10]. On

the T1-weighted scan, white and gray matter appear as they do in anatomy.

However, on the T2-weighted scan, the white matter appears darker gray

than the gray matter, which is contrary to the anatomy [6]. The detection of

brain tumors heavily relies on imaging. Tumors are observed to have a darker

appearance than brain tissue on T1-weighted scans and a brighter appear-

ance than brain tissue on T2-weighted scans [11]. Inflammations have similar