What does CT value in RT-PCR report mean? Doctor explains
Amid the ongoing second wave of the pandemic, as states are conducting a higher number of Rt-PCR tests, people are now aware of a new term, called CT value, a score written on the RT-PCR report, if the outcome of the test is positive. According to ICMR documents, CT value is the cycle threshold value, which is "inversely proportional" to viral load, which means the lower the number higher the viral load and vice versa. But the value can differ from one kit to another and the viral load does not have much role in patient management, the ICMR has said.
Dr Hemant Deshmukh of Mumbai's King Edward Memorial Hospital has said if the value is over 35, then it is considered a negative result and when the value is below negative, the result is considered positive. The number suggests the number of cycle after which the virus has been detected. So in general, if the CT Score is, for example, 20, it means the virus is spotted in 20 cycles, thus implying that the load is higher than a score, for example, 30.
"But whatever the value is, be it 10 or 28, an infected person can spread the virus," Dr Deshmukh said.
What is CT Scan score?
Dr Deshmukh said doctors may advise CT Scan if a patient does not get cured of fever or cough after medicine. A CT scan score of 5 out of 25 is considered normal. "If the score is more than that, then the doctor may advise to get hospitalised. But sometimes, even if a patient has a higher CT Scan score, he or she may not have any inconvenience. "Nowadays people are googling a lot and becoming doctors themselves. But regarding CT scan, one should take the doctor's advice," Dr Deshmukh said.
AIIMS chief Randeep Guleria recently said Covid-19 patients should not rush for CT scan as it increases the risk of cancer. One CT scan is equivalent to 300 to 400 chest x-rays, Dr Guleria said adding that people with mild covid-19 and normal oxygen saturation should not do CT scan.