What tests should be done for tuberculosis?

My cousin was recently diagnosed with TB. He had severe coughing problem since past 2-3 months & no medicines were working. He also lost 5kgs. The doctor then advised to take an X-Ray (chest PA) which showed "Koch infection in upper part of the right lung". Then he did a blood test (CBC & ESR). Today the doctor prescribed this medicine AKT-4 for 2 months. I wanted to know whether just a chest Xray & blood test is enough to diagnose TB & start with the treatment or should there be any other tests done to confirm the disease before taking AKT-4?