1.1. Related Works
OlfaHrizi, Karim Gasmi., et al. have investigated that Tuberculosis (TB) is a very contagious disease that directly effects on lungs. Then it is called pulmonary TB” while when it affects the other body organs, it is called extrapulmonary TB. Computer science plays a vital role in the medical field in detecting different diseases. The authors optimized a machine learning-based approach which extracts optimal texture features from Scanned images and selects the classifiers’ hyper-parameters, increasing the accuracy rate.
Zhiheng Xing, et al. discussed in their research that many diseases spread all around the world very rapidly. For this purpose, many computer-based techniques have been used to find accurate results that help cure different diseases. This study explains two main factors: cavitary and bronchiectasis regions in CT images, which elaborate a machine learning approach to lung diseases. This study provides insight into machine learning-based identification of NTM lung diseases from PTB, and more importantly, it makes early and quick diagnosis of NTM lung diseases possible that can facilitate lung disease management and treatment planning.
Díaz-Huerta, J.L., et al. proposed a segmentation-based method for detecting acid-fast bacilli to diagnose pulmonary Tuberculosis [
9]. 200 images from 30 oscilloscopes processed using staining were obtained as a dataset. A database was created by collecting RGB values of these selected images, extracted by MATLAB program NetLab3_3library was used to train Bayes classifier + Gaussian mixture for training pf background and bacillus class. A total of ten centers, 6 Gaussians for bacillus and 4 for the environment, were determined by using K mean algorithm. Later, 200 images were classified into the following classes “adequate, little blue and purple, excess of blue or purple, bacilli stained in both blue and purple colors.” This bacilli segmentation has an effectiveness of 92.0% for original images and 98% for normalized images. The presented method is considered reliable due to different images’ significance ranging from 85 to 97%. Pre-processing can help eliminate variability by producing standardized RGB image components, enhancing system robustness. To get adequate segmentation resolution of the image must be considered [
10]. Rohmah, R.N., et al. proposed a statistical approach for pulmonary tuberculosis detection especially addressing two problems, namely “long waiting time for patients” and “doctor subjectivity.” The dataset consists of 25 regular and 25 TB digital grayscale X-ray images obtained from Sardjito Hospital, Yogyakarta, which were used for training classifiers. Later on, 50 more images were also used for testing system performance. After image acquisition, ROI templates were created through pre-processing, including image cropping, resizing, image averaging, and grey level thresholding technique” five statistical characteristics of image histogram entropy, kurtosis, skewness, mean and standard deviation were calculated. Two feature reduction methods, PCA (principle components analysis and LDA (linear discriminant analysis), were compared. Minimum Euclidean distance and Mahalanobis distance classifier were used for classification by calculating statistical features. Primary and secondary image test results were 94.0 and 83.35% accurate [
11]. Andayani, U., et al. described a probabilistic neural network-based methodology for the early detection of pulmonary Tuberculosis. 105 standard X-ray and 105 X-ray images with pulmonary Tuberculosis were acquired as data sets for system training. These acquired images have been through resizing, morphological close, Gaussian, thresholding, contrast, and Canny edge detection during pre-processing. Invariant Moment shape characteristics were used for feature extraction, and seven values were taken as features. A probabilistic neural network (PNN) Classifier was imposed to classify features into two classes standard and Tuberculosis infected. PNN successfully identified tuberculosis disease with 96% accuracy [
12]. Balaji et al. proposed a segmentation algorithm for improving Computer-Aided Diagnosis systems that diagnose chest disorders using Computed Tomography. The improvement was based on development that will identify significant features of an image for differentiation of different lung diseases. Developing the proposed work will assist physicians in better diagnosis and treatment and reduce the mortality rate by improving the analysis of CT slices for diagnoses of lung disorders [
13].
Hooda, et al. presented a deep learning-based automatic system with significantly high accuracy for TB detection through chest radiographs. The proposed method is a result of successfully assembling three standardized architectures: AlexNet, ResNet, and GoogleNet. The data set of 1133 (499 normal and 634 with TB abnormalities) CXRs were acquired from four countries in the world, namely USA, China, Japan, and Belarus, for training testing and validation. Above mentioned three architectures were adapted for training from scratch. The performance of the trained system was evaluated with four different matrices, and it achieved an accuracy of 88.24%, sensitivity of 88.4%, and area under the curve (AUC) of 0.93 [
14].
Auwal, N., et al. described an image processing-based technique for determining the severity level of TB. This research is essential because all severity levels of TB, mild, moderate, severe, and very severe treated differently. CXR Images of TB patients acquired from google were enhanced into grayscale color map images (GI) from RGB color map. These images were observed one by one, histogram equalization displaying intensity level and several pixels were created, and expert’s opinions about severity level for comparison later. Image degradation, including decomposition, convolution, compression, and filtration, was performed on GIs. These degraded images were converted to binary and restored with a threshold value greater than 53. The severity level was calculated by indicating an area of infection in the region of interest. Less than 50% of the infected area means mild, 50–70% area moderate, 70–80% severe, and more than 80% of the infected area indicates very severe TB infection [
15].
Kim, W., et al. proposed that Computerized tomography (CT) is useful in diagnosing pulmonary diseases TB, lung cancer, Pneumonia, bronchiolitis, metastasis, as well as active and inactive states of TB. Initially, 226 patients were kept under observation, but 38 patients were excluded due to the unavailability of patients for follow-up. Out of the remaining 188 patients, 91% (133 of 146) with pulmonary TB and 76% (32 of 42) without TB were correctly identified. The remaining eight patients with lung cancer, three with Pneumonia, one with diffuse panbronchiolitis, and one with pulmonary metastasis were also diagnosed using CT. Out of 146 TB cases, 80% active and 89% inactive cases were correctly identified [
16].
BulutGökten, D., et al. concluded that in most cases, peritoneal TB mimics ovarian cancer and carcinomatosis. Doctors can save the life of a pulmonary TB patient with a timely and correct diagnosis. However, early diagnosis is challenging for clinicians, but careful follow-up and timely treatment is the only way to save a life. So far, advanced diagnostic tests and techniques are not reliable enough to trust with patient life. Still, other clinical information and diagnosing designs can help improve accuracy and conclusion about disease detection [
17].
Kant, et al. presented a Tuberculosis detection methodology based on a Deep Learning Neural Network with an accuracy of 83.87% and a precision of 67.55%.
The proposed methodology detects (rod-shaped) bacteria called bacilli in a microscopic image with a specific zoom level. This methodology and TB can also detect other diseases caused by a bacillus. Patch-wise detection strategy was used to classify an image into one of the two classification groups, one with bacillus and the other without bacillus. The architecture of the proposed system was based on five layered, entirely convoluted Neural networks [
18].
Eddabra et al. after comparing molecular TB diagnostics with traditional TB testing, the former is much better than the latter concerning time, as molecular diagnostics give reliable results within hours. On the other hand, in the case of sensitivity, molecular tests have lower sensitivity than traditional testing. Molecular tests are costly due to the requirement of laboratory infrastructure and expert technicians. Molecular diagnostics cannot wholly replace cultural testing; however, it may assist technically. Revolutionary technique whole genome sequencing (WGS) can be trusted best, but it demands high-cost resources like complicated bioinformatics procedures, sequencing facilities, and technical skills [
19].
Antony et al. proposed a machine learning classification-based methodology for the detection of pulmonary TB through chest X-rays with an accuracy of 80%. 326 normal and 336 abnormal (total = 662) X-rays images of lungs acquired from the National Library of Medicines were taken as input images. Gaussian and Median filters were applied in the pre-processing phase. These pre-processed images went through two types of segmentations: gray–level threshold and watershed segmentation. Regional properties (like area, eccentricity, major axis, and minor axis) were calculated. Statistical features (like mean, standard deviation, skewness, and kurtoses) were extracted and classified by K-Nearest Neighbor (KNN), simple linear regression, and sequential minimal optimization classification (SMO) with an accuracy of 79%, 80%, and 75% respectively [
20].
Nachiappan et al. tuberculosis is a universal problem, equally important for developed and developing countries, and awareness of its risk factors is essential to control or slow down its propagation. Imaging is vital in differentiating many patients’ latent infections from inactive and active diseases. Images findings in patients can identify non-tuberculosis mycobacterium pulmonary infections that mimic tuberculosis infections. This finding is significant because non-tuberculosis and tuberculosis infections cannot be treated similarly. Improper treatment of tuberculosis infection may lead this disease to an incurable stage resulting in a valuable life loss [
21].
Nour-Neamatollahi et al. proposed an advanced methodology named “Patho-TB” for the acid-fast bacilli (AFB) test. Traditionally acid-fast bacilli test was human skills based with low sensitivity, but the proposed new method was claimed to be more sensitive and less human skill-based. The research was conducted in two phases initially, 38 sputa from Zabol city (Iran) and later on, 476 sputa from Tehran (capital of Iran) were examined by four different methodologies (named Patho-TB, AFB microscopy, culture, and PCR), and results were compared. The patho-TB test’s reduction was almost 100 (with a Cohan kappa value between 0.85–1). The detection Patho-TB test was also 100% positive [
22].
Pai, M. et al. explained that its detection is always challenging due to the paucibacillary nature of extrapulmonary-TB, especially in developing countries. The modern world has created Nucleic Acid Amplification Test (NAAT) to meet the challenge of ensuring rapid and accurate diagnosis; however, it is more complex as compared to traditional diagnostic techniques. NAAT can perform better with conventional methods but cannot completely replace traditional procedures like culture, microscopy, biopsy, etc. [
23].
Parsons et al. concluded that rapid and accurate methods for detecting TB, and HIV must be made accessible in developing countries to control these fetal diseases. For TB detection, there is no stand-alone test for any patient. Some technique is cost-effective and straightforward but unreliable. At the same time, other complex methods are reliable but more expensive and need technical assistance at their best. Therefore, it is required to ensure that all techniques, especially those recommended by the World health organization (WHO), are available in every country for different kinds of cases. Without proper clinical correlation, only laboratory test results cannot be trusted. For appropriate treatment, laboratory diagnostics and clinical information must be correlated [
24].
Shuaib et al. proposed a methodology for calculating the positive predictive value of sputum spear for suspected lung tuberculosis patients in (eastern) Sudan. A total of 383 suspected patients were kept under examination, and two samples were collected from suspected patients in duration between June to October 2014 and January 2016 and July 2016. The sample went through repetitive microscopy and culture for results. A total of 196 was found culture positive, where 171 were infected by M. tuberculosis, and 14 by M. intracellular, and only 11 by mixed specie. 56 of 365 had no signs of m. tuberculosis, raising optimistic prediction to 84.4%. All samples were referred to National Research Laboratory, Germany, for better results [
25].
Singer-Leshinsky, et al. suggested treatments, diagnostics, and prevention for different situations of TB. Patients with latent TB living with a high prevalence of TB need nine-month isoniazid or more prolonged therapy to ensure latent TB does not progress to active TB. It is the priority for any clinician that patients with active TB must not become resistive to anti-TB drugs; active TB treatment consists of two phases and almost has a cure rate of 95%, four drugs (regimen: isoniazid, rifampin, pyrazinamide, and ethambutol) for the duration of two months can kill active bacteria, in almost 90% patients it takes 14–90 days for health recovery. Multidrug-resistant Tb is the most difficult to recover due to its treatment and detection inadequacy. This is when a TB patient shows resistive behavior to rifampicin and isoniazid anti-Tb drugs. First, it is necessary to know the resistance pattern by repeating sputum tests and then decide on the duration of treatment. Initially, 4 second-line drugs on daily bases along with therapy are recommended for eight months.
In some cases, this phase is extended up to 20 months or, in the case of recurrent TB, 28 months. Surgical resection is often recommended if patients do not respond to therapy. Third-line drugs are required in this case (called total drug-resistant TB) [
26].