Tuberculosis, is a pathology that caused by bacterial infection that spread by air between people. When it comes to lung, the medical term for this pathology are pulmonary tuberculosis. It may cause chest pain, severe coughing, weight loss and many more.
Pulmonary tuberculosis is a worldwide problem which is can affected to all age, either young or old age. Tuberculosis can divide to two groups which are active and latent forms. For the active disease, it can occur as primary tuberculosis, post primary tuberculosis, developing of latent tuberculosis. Primary tuberculosis usually infect the children.
Normal chest radiography are used to diagnose for the risk and to assess the asymptomatic tuberculosis disease. It is needed because sometimes nontuberculosis mycobacterial disease can mimic of the findings of active tuberculosis which laboratory confirmation is required to make distinction. Conventional imaging is important for the diagnosis and management of the tuberculosis patient. There are three projection that usually used to evaluate pulmonary tuberculosis which are PA erect, AP erect and AP lordotic view.
PA ERECT CHEST
PA erect chest is a very common projection in evaluating thorax cavity. The posteroanterior (PA) chest view examines lungs, bony thorax cavity, mediastinum and vessels and usually used in diagnosing acute and chronic conditions including organs of the thorax cavity. In addition, pulmonary tuberculosis (PTB) is affecting lungs.
To get a good image, the patient is in erect position facing the image receptor with the border of the image receptor is about 5cm above the shoulder and chin is raised up. Rotate the shoulder anteriorly to allow the scapula move laterally off the lung field and shoulder also are depressed to make sure lung apices in profile.
In evaluating PTB in normal chest x-ray, PTB can be found in some condition such as air space nodules in the upper or midzone of the lungs. In addition, thick walled cavity, unilateral hilar and plural effusion or empyema can be indicators to detect PTB.
In the diagram above are images of active TB. In radiograph A, its right upper zone shows consolidation with prominent right hilum. In radiograph B, the images shows multiple coalescent air-space nodules in right lung upper zone. Meanwhile in radiograph C, reticulo-nodular lesions in both lungs with basal predominance can be seen. Scattered air space nodules are seen in both lungs with left hilar adenopathy can be seen on radiograph D. Lastly, the right sided pleural effusion with multiple air-space nodules scattered in both lungs can be found on E image.
AP ERECT CHEST
The erect anteroposterior chest view is performed with the x-ray tube is anteriorly through the patient to form image on the image receptor which is placed behind the patient. The image receptor can be positioned behind a immobile patient. This projection is an alternative to the PA view when the patient is too unwell to standing or leaving the bed. AP projection also examines lungs, bony thorax cavity, mediastinum and great vessel. AP view usually to aid of diagnosis of acute and chronic conditions in intensive care units and wards. This view has lesser quality than the PA view for some reasons but sometimes it is the only projection that available for the patient.
For the positioning, the patient is upright as possible with their back against the image receptor and the chin is raised to avoid included in the image. If possible, placed patient’s hand at side and shoulders are depressed to move the clavicles below the lung apices for better image.
In detecting PTB using this projection, the image evaluation is more like PA projection which are air space nodules and many more. AP erect chest usually done for PTB patient that was immobilized and very unwell to do PA chest.
AP LORDOTIC PROJECTION
Beside PA and AP normal chest projection, there is one special projection that can be used as examination to detect pulmonary tuberculosis. AP lordotic chest radiograph or AP axial chest radiograph demonstrates areas of the lung apices that may be not seen in AP and PA projection. It is used to evaluate suspicious areas within the lung apices that appeared obscured by overlying soft tissue, upper ribs or the clavicles on previous projection.
For the positioning, the patient is standing around 30cm away from the image receptor with back arched until upper back. Shoulders and head are against the IR. The shoulder and elbows are rolled anteriorly with the angle of the tube 45 degrees cephalic to the midcoronal body plane and image receptor. Breathing technique is applied.
In this article, I have mentioned the approaching technique that can be used to evaluate pulmonary tuberculosis. There are 3 projection that normally used to diagnose pulmonary tuberculosis. PTB can be found in any age either in children or adults. Thus, selecting the suitable projection are important to evaluate the disease because it is easier to diagnose and set disease management for the patient.
In my opinion, PA chest are the best projection to evaluate PTB. This is proven by using PA projection, all the lung field can be seen in the radiograph. All the requirement that need to fulfil in evaluating this disease can be achieved. Furthermore, PA projection also have better image quality than AP erect chest. Moreover, this projection also is a gold standard for pulmonary tuberculosis and other thorax cavity disease and abnormality. However, if the disease are hidden in the area of the lung apices, AP lordotic can be as a alternative projection to evaluate pulmonary tuberculosis. Besides, using other modalities such as CT scan can be helpful to confirm the disease or act as a supplement for the treatment for pulmonary tuberculosis.