The Visualization of Asthma Through Imaging

In this paper readers will be able to know some different aspects of asthma related with the imaging field. Some of the aspects that will be investigated on this pathology are the symptoms that it produces, the imaging modalities that are the most effective in diagnosing this condition, and the visualization of asthma in medical images. This topic will be developed using different educational web pages as a reference; with the purpose of providing more complete and specific information. Moreover, this document aims to promote and inform factors that are important to keep in mind about asthma when performing a radiological exam.

History

Asthma is a chronic inflammatory lung condition that affects the upper respiratory tract. This pathology has a long history of evolution, before it was categorically defined. According to Cannizzarro (2017), the first recorded case of respiratory distress was found in China in 2600 a. C. and, it was characterized by 'noisy breathing'. At that time, the conditions that affected and produced the negative effects on breathing were unknown, but people who had respiratory problems were treated with natural plants. The plants were heated on stones and the fumes generated by the plants were inhaled by people with respiratory problems. These techniques helped improve their conditions, but there was no scientific evidence of how plants produced a positive effect on them.

Then in ancient Egyptian times, Georg Ebers data was found containing more than 700 recipes written in hieroglyphics for breathing-related problems (Cannizzarro, 2017). The finding of this information based on natural remedies was very important for medical specialists to develop research on respiratory issues. One of the specialists who developed important research on respiratory distress was Hippocrates. Hippocrates was known as the grandfather of medicine and he was the first to use the term asthma as shortness of breath. This physician mainly focused on discovering the causes of asthma. After conducting several studies, Hippocrates realized that one of the causes was related to environmental factors. Moreover, after his observations and investigations, he classified asthma as a respiratory disease that developed most commonly among people who worked with metal, fishermen and tailors.

Time later, a Greek doctor Aretaeus of Cappadocia began to observe people who had asthma to discover the symptoms that caused this condition. After his observations and data collection, he wrote that shortness of breath, cough, tiredness, and heaviness in the chest were the most common symptoms of asthma. Aretaeus also showed that if the patient's condition gets worse the symptoms would become more prominent and the cough would be more frequent (Cannizzarro, 2017). On other hand, some of the treatments recommended for asthma patients by this Greek doctor included drinking owl blood in the wine. In those times thanks to his research, Aretaeus was credited with the first accurate description of asthma. Then in the Middle Ages, Europeans began using tobacco to treat asthma. In Central America, the Aztecs used a plant called ephedra, and in South America the Incas used the dried leaves of the cocaine plant (Patel, 2019). In other words, different civilizations began treating asthma with natural plants, without having a clear understanding of the effect that plants produced in the respiratory system.

Later, in the 40s and 50s, asthma studies and treatments were progressing thanks to medical advances. Some doctors discovered that asthma had a certain relationship with allergies and that these could be treated with the inhalation of anti-cholinergics. In the 60s and 70s, the creation of peak flow meters was a powerful tool that helped an effective treatment of asthma. Then, in the 1970s, a large clinical inspection led to the use of inhaled corticosteroids was an appropriate administration to treat asthma (Patel, 2019). So today, after centuries of research and observations more promising options are being developed to treat asthma patients.

Manifestations of the Pathology

Asthma is a respiratory disease that affects many people around the world. According to an article of the Mayo Clinic (2018), Asthma is a condition that develops in the respiratory system and causes swelling and narrowing of the airways. As well, asthma causes the airways to produce additional mucus which results in shortness of breath, wheezing, and lead to coughing. Asthma symptoms have different levels of intensity in each person. For some people, it can be an occasional condition that only manifests itself when they do some physical activity, for others it can be a condition that is present all the time. Furthermore, not all people suffer from all the symptoms caused by asthma; some suffer less symptoms than others.

On the other hand, asthma is a respiratory condition that can be caused by different factors. The first factor is polluted air. This generally affects people who work or are exposed to irritants such as gases, dust, and fumes that contain chemicals. Then, asthma can be caused by allergic factors that are transmitted by airborne substances such as pollen, animal hair, and mold (M Clinic, 2018). Moreover, there are people who only develop asthma while doing some sport or exercise. So although there are many ways to develop this condition, the most common symptoms are chest tightness, shortness of breath, and coughing or wheezing attacks.

Imaging Modalities Used to Diagnosis and Demonstrate the Pathology

The imaging modalities that are most frequently used to diagnose asthma are x-rays and high-resolution computed tomography. A chest radiograph is the initial imaging evaluation that is performed on people with asthma symptoms (Grimm, 2016). The reason is because this modality quickly allows doctors to visualize the area of the airways and lungs. In other words, thanks to the radiographs doctors can diagnose and treat patients with asthma faster. On other hand, high-resolution computed tomography is another important modality to diagnose asthma. This modality is useful in patients with chronic or recurrent symptoms and in those with possible complications such as allergic bronchopulmonary aspergillosis and bronchiectasis (Grimm, 2016). Therefore, both modalities have an important role in the differentiation of asthma and other similar conditions.

Discussion of Additive and/or Subtractive Properties of Pathology

In order to demonize asthma in one of these categories it is important to mention the difference between an additive and a subtractive pathology. An additive pathology, is all that condition or disease that increases tissue density. On the contrary, a subtractive pathology is that condition decreases or degenerates the tissue density. Moreover, diseases that increase the presence of air in different parts of the body are also considered subtractive pathologies. Asthma being a condition with different stages can be characterized as a subtractive or additive pathology depending on the stage in which the patient is treated. In some stages it is considered as a subtractive pathology, since asthma can generate pneumomediastinums. In advanced stages, asthma can become an additive pathology due to bronchial thickening and excess mucus in the airways.

Advancement of Pathology and Visualization on Images

On chest x-rays, asthma will be visualized in different ways. According to Grimm (2016), on a posteroanterior chest radiograph, a pneumomediastinum can be seen in bronchial asthma. In other words, a PA chest x-ray will show mediastinal air adjacent to the anteroposterior part and the trapped air is going to extend to the neck. In the lateral view of a chest x-ray, pneumomediastinum can be seen in the anterior area of the trachea. Then, in a patient with asthma CT images will show a mosaic pattern of pulmonary attenuation.