Which of the following tests is commonly used for the diagnosis of tuberculosis?

A chest X-ray is commonly used for the diagnosis of tuberculosis as it helps identify abnormalities in the lungs that may indicate an active infection. Tuberculosis often presents with specific radiographic findings, such as cavities in the upper lobes of the lungs or infiltrates that are characteristic of the disease. While a chest X-ray cannot confirm tuberculosis on its own, it is an essential tool in the diagnostic process, often guiding the need for further testing, such as sputum analysis for acid-fast bacilli or a CT scan for more detailed imaging.

Other methods, like CT scans, are utilized when more detailed imaging is necessary, but they are not the first-line diagnostic test. IgM Western Blot tests are not applicable for tuberculosis diagnosis; they are more associated with viral infections. Blood smears are also not suitable for diagnosing tuberculosis, as they are used primarily for identifying specific blood components or infectious agents in other contexts. Thus, the chest X-ray stands out as the most commonly employed test in initiating the diagnosis of tuberculosis.