The computerised tomography scan (CT scan) cannot properly detect mild coronavirus cases, AIIMS Director Randeep Guleria said at a press conference on May 3, as he warned against its misuse. The top doctor, who is also a member of the national pandemic task force, added that blood tests can't always prove Covid-19 infections as other underlying diseases can also trigger a spike in biomarkers. The CT scan machine takes cross-sectional images of the body using computers & rotating X-ray machines. They are being used to detect Covid-19 infections by detecting signs of pneumonia or white patches in lungs. “There is no use of the scan in early stages as it will not detect (Covid-19) properly in mild cases, " Dr Guleria said. He said asymptomatic patients with normal oxygen saturation should not go for CT scans. India's total Covid-19 cases crossed the 2-crore mark with over 3.57 lakh new infections. 3,449 more people died of the infection, pushing the total fatalities to 2,22,408. The massive caseload has caused shortages of medical oxygen, hospital beds & essential medicines.