Respiratory Medicine: Different Advances in Recent Times

Introduction

Medicine is an ever-changing field. Several modernizations have taken place in the field of medicine over the years. Respiratory medicine is also an integral branch of modem medicine. Several modifications, like modern diagnostic aids, the use of nuclear medicine, and the use of techniques in detecting lung cancer, are useful in eradicating lung diseases.

What Are the Modern Diagnostic Tests in Respiratory medicine?

Diagnostic tests are the most important tools of modern medical practice. Several modern diagnostic procedures are used nowadays for detecting pathological lung changes and for evaluating lung functions. These procedures are:

• Ventilation and Perfusion Scan: This is a set of two diagnostic tests which are used to access blow flow and the airflow parameters of the lung. Radioactive substances are injected or inhaled for the purpose of these diagnostic tests. Various pulmonary disorders like pulmonary embolism (presence of blood clots in the lung circulation), chronic obstructive pulmonary disease (obstruction of the airflow in the lung), asthma, pulmonary edema (accumulation of fluid in the lung), and acute respiratory distress syndrome.

• High-Resolution Computed Tomography (HRCT): This is the modification of traditional computed tomography imaging. High energy spectrum, increased speed of tube rotation, increased number of sensors, and high sensitivity of the sensors are used for better image acquisition. The average thickness of the slices is 0.625 to 1.25 millimeters. This procedure helps in the reduction of artifacts formation during breathing. Also, three-dimensional reconstruction of the lung structures is possible in this method.

Another variation of computed tomography imaging is the use of a dual-energy source. This is known as dual-energy CT (DECT). An iodine contrast medium is used in this procedure to study the change in the tissue response in the presence of high and low-energy spectra. These diagnostic procedures are used in the direction of conditions like sarcoidosis (collection of inflammatory cells in the lungs), fibrosis of the lungs, and pulmonary vascular diseases.

• MRI (Magnetic Resource Imaging) Using Noble Gases: The lung structure is filled with gaseous substances, and the concentration of hydrogen ions is less. Because of these complexities, the reconstruction of lung images through magnetic resonance imaging is difficult. Inert noble gasses are used to overcome these limitations. Hyperpolarized noble gasses such as Xenon are used in such cases. These gasses are helpful in assessing lung ventilation and are functional efficiency. But availability and cost factors are the main drawbacks of this technique. Oxygen-enhanced MRI (OE-MRI) is now being used to overcome these drawbacks. In this procedure, 100 percent oxygen concentration is used to determine lung function.

What Are the Uses of Radioactive Substances in Nuclear Medicine?

Radioactive substances are used to study cellular function and the identification of morphological changes in lung tissues. These are particularly helpful in diagnosing lung cancer at an early stage.

1. Gallium-67 Citrate: This is one of the most widely used molecules in pulmonary nuclear medicine. Accumulation of these tracers can be seen in various conditions like sarcoidosis and Pneumocystis carinii pneumonia (PCP) in HIV (human immunodeficiency virus) patients and in various granulomatous disorders.

2. Indium-Ill Oxine Labeling of White Blood Cells: White blood cells are labeled using these tracers. These are used to confirm intrapulmonary inflammations.

3. Thallium-201 Chloride: These radioactive tracer molecules can be useful in detecting malignancy. Non-Hodgkin's lymphomas, lymphomas can be detected using these tracers.

4. Technetium-99m Glucoheptonate: These tracers are used to detect the blood flow activity of the neoplasms.

5. Iodine-123-labeled Somatostatin Analogue: Small cell carcinoma of lung cancer can be detected using these tracers. These tracers can be used to label somatostatin receptors which can be useful for the detection of small-cell lung cancer.

6. Indium- 111 Labeled Carcinoembryonic Antigen-Specific Monoclonal Antibodies: Carcinoembryonic antigen is a specific type of glycoprotein that can be seen in lung cancers. Monoclonal antibodies present against such antigens can be identified using these tracers.

What Are the New Technologies For Early Detection of Lung Cancer?

Lung cancer is the second most prevalent cancer in the world. Every year 1.8 million people lose their life due to this disorder. Several modern diagnostic aids are used for the early detection of lung cancer.

1. Low-Dose Computed Tomography (LDCT): This is a single-slice spiral computed tomography technique. This method uses low radiation for good contrast imaging of air and lung tissues. Chest images can be taken in a single breath which reduces the chance of prolonged exposure. This is helpful for the detection of different nodules present in lung cancer. Also, cardiovascular diseases and other lung diseases like COPD can be detected. This can be useful in reducing lung cancer-related mortality due to the reduced amount of exposure.

2. Endosonography: In the past, lung biopsy was done using the fluoroscopy technique. This new method is based on an endobronchial ultrasonography procedure. In this method, an ultrasound probe is covered with a sheet and inserted with the help of a bronchoscope. This method is helpful for the localization of cancerous lesions, and the final needle aspiration of the lung tissues can also be done. Endoscopic procedures can be helpful in diagnosing.

3. Sputum Cytology: The cytological analysis of the sputum has been identified as one of the most advanced procedures for the detection of early stages of lung cancer. In this procedure, Immunostaining with heterogeneous nuclear ribonuclear protein (hnRNP) is done for the detection of malignant changes in the DNA.

4. Pleural Fluid Cytology: In this procedure, fluid within the lung is collected and accessed. This procedure is more accurate than sputum cytology.

5. Identification Of Biomarkers: Biomarkers are biological molecules that can be accessed for the detection of pathological conditions. BRAF, HER2, PTEN, EGFR, ALK, ROS, and KRAS are different biomarkers that are evaluated for detecting lung cancer. Biosensors are used to study biomarkers. These machines convert chemical signals into electronic responses.

6. Liquid Biopsy (LB): This is a new procedure in which the blood sample is collected, and proteomic assessment of a wide variety of tumor-derived molecules such as circulating tumor cells circulating tumor DNA (ctDNA), tumor-derived extracellular vesicles (EVs) is done. This procedure helps to eliminate potential complexities of biopsy and radiological techniques. Molecular assessment helps to pinpoint the exact cancer disorder and its progression.

Conclusions:

Diagnostic methods are useful for the proper diagnosis and staging of diseases. Modern diagnostic methods are useful for the proper visualization of lung structures without distortions. Early detection of lung cancer with the help of modern techniques can reduce the mortality rate. Also, the use of substances like radioactive materials can be fruitful in various diagnostic procedures.