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Tumor Discovery                                                  An approach for classification of lung nodules



            6.1. Lung nodule segmentation                      7. Feature extraction

            In region growing, the procedure called labeling is done to   The diameter, area, irregularity index, and perimeters are
            put the negative number representing the label of the region   some of the geometrical features that will be evaluated from
            to which the pixel has a place. The labeling process keeps   the separated lung nodules. The number of pixels in the
            tracks of the record of pixels which are yet to be replaced   picture array with the value 1 will be used to determine the size
            by the labeling. With this reference list, the operation of   of the segmented tumor image. The area is estimated using
            insertion and removal will be carried out. Removal is done   the established technique using bit quads, or 2-by-2pixel
            by eliminating the pixels from the front list, and insertion   patterns. The quantity of boundary pixels provides an
            is by inserting the pixels at the end of the list.  estimate of the tumor image’s perimeter. In terms of its

            A               B              C                   morphology, the tumor has a circular form. The circulatory
                                                               index will be calculated to identify the irregularity in the
                                                               circular shape using the expression I = 4πA/p2, where A is
                                                               the area of the tumor and P is the perimeter of the tumor in
                                                               pixels. Table 2 shows the geometrical features for Figure 5.
                                                               The important features used in the lung cancer classification
                                                               are texture or contrast features.

                                                                      st
                                                                                         nd
            Figure 5. (A) Original image, (B) separated lung fields, and (C) separated   The 1   order statistic and 2   order statistic are the
            cancerous portion                                  categories under which the contrast features are classified.
                                                               The shorter processing time and lower minimum cost are
            Table 2. Calculated SMF of the filtered images for all types   the advantages in feature extraction using wavelet due to
            of filters                                         the solid depiction of the wavelet transform.
             Filter type                        Output SMF     8. Classification of lung nodule
            Average filter                        7.3133
            Weighted average filter               4.2478       Classification is the process of determining whether the
                                                               nodules belong to a specified class or not. In supervised
            Gaussian filter                       6.4443       classification, samples and anticipated classes are known
            Selective median filter               8.5816       before a classifier is trained on a set of data. It is evident
            Wavelet filter                        8.8732       that supervised classification-based methods consistently
                                                                                                           [43]
            Wiener filter                         13.3969      outperform other types of traditional classification methods .
            SMF: Selective median filter                       Classification of  nodule in  the  lung is  accomplished using

            Table 3. Performance metrics of solid feature for various inertia weights
             Classifi ers  Accuracy y  Sensiti vity  Specificit y  PPV  NPV     F‑measu re   G‑mean      MC
            DS             88          92          84        85.18      91.30     87.81       87.9       0.76
            RF             88          92          84        85.18      91.30     87.81       87.9       0.76
            Ada-DS         86          92          80        82.14      90.9      85.58       85.79      0.72
            Ada-RF         90          100         80        83.33      100       88.89       89.44      0.81
            BPNN           98          96          100        100       96.15     97.95       97.97      0.96
            PPV: Positive predictive value, NPV: Negative predictive value, DS: Decision Stump, RF: Random Forest, BPNN: Back Propagation Neural Network
            Table 4. Performance metrics of part‑solid feature for various inertia weights

             Classifie rs  Accura cy  Sensitiv ity  Specifi city  PPV    NPV       F‑measur e   G‑mean     C
            DS             77.6         60.19        95.14      92.53     70.5       73.54       76.17    0.59
            RF             86.2         85.4         86.4       86.27    85.57       85.49       85.49    0.72
            Ada-DS         87.9         83.5         92.2       91.48    84.82       86.81       87.74    0.61
            Ada-RF         86.4         85.4         87.4       91.48    84.82       87.89       86.39    0.76
            BPNN          93.68         91.26        96.1       95.91    96.11       93.43       93.46    0.87
            PPV: Positive predictive value, NPV: Negative predictive value, DS: Decision Stumpe, RF: Random Forest, BPNN: Back Propagation Neural Network


            Volume 2 Issue 1 (2023)                         6                           https://doi.org/10.36922/td.317
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