You and Me: To CT or not to CT?

If CT scans are repeated every other day, it not only exposes the patient to significant radiation, increases financial burden, but can add to the risk of spreading the infection. Patients treated in smaller hospitals that do not have an in-house CT scan unit are referred to facilities outside. They often travel, mostly without protection (like PPE kits or even proper masks), accompanied by relatives who are also likely to be infected. On the one hand, we advise prompt isolation as soon as symptoms occur and on the other, COVID patients freely move around for CT. At least the simple X-ray is usually available in many hospitals or a portable one can be arranged and decrease the movement of these spreaders.

Dr Varsha Rote,

Professor and Head, Radiodiagnosis, GMC, Aurangabad

·CT should be done only when indicated and not as a substitute for RTPCR. Not needed in asymptomatic/mild cases who are maintaining oxygen levels

·The radiation that the patient gets from one HRCT chest = 70-140 X-rays!

·Small patches may be seen in mild cases also. Correlate with clinical picture, blood tests and oxygen levels.

·May be used exceptionally for diagnosis, if RTPCR is repeatedly negative but symptoms are strongly suggestive. Do RTPCR first, isolate and watch oxygen levels.

·25% HRCTs are normal in first 5 to 6 days, which leads to spread of the disease and late admission in serious condition.

·One may repeat, in a serious patient not responding to treatment, but if you have already been giving all possible therapy, then oxygen levels and certain blood tests will be more helpful.

Dr Thomas George, Consultant Radiologist, Kamalnayan Bajaj Hospital

·RTPCR remains the gold standard for diagnosis, HRCT chest should not be used as a primary diagnostic tool.

It’s indiscriminate use should be strongly discouraged.

·HRCT should not be done in asymptomatic patients or patients with mild symptoms – 1) Normal HRCT may lead to complacency.

2)Unnecessary exposure to radiation. A single HRCT chest gives a radiation dose of 4-7 mSv (equivalent to 60-80 x rays).

· Should be done in patients with persistent or worsening symptoms with decreasing oxygen saturation, who require hospital admission.

·HRCT is useful for diagnosis in few symptomatic patients in whom repeated RTPCR is negative.

· It can be used to triage patients with comorbidities like heart failure, renal failure with respiratory distress.

·HRCT chest need not be repeated unless the patient does not respond in 4-5 days .

·HRCT is the more effective radiological tool but X-ray chest is useful in the initial evaluation of mild symptomatic or some bed-ridden patients and for follow up in admitted patients. X-ray chest is easily available, costs less and gives less radiation (0.05-0.1mSv).

·50-55% of mild/asymptomatic patients will show abnormalities like ground glass opacities (GGO) 4-5 days after the symptoms.

·There is no justification for repeating a CT every second or third day.

·A significant increase in CT severity score with progression of opacities to confluent organizing consolidation is a red flag.

·Injudicious repeated CT should be prohibited as it creates the risk of increased probability of malignancy, cataract, infertility etc.

Patients and their relatives should not demand a HRCT chest but leave it to the treating doctor.

Dr Shrinivas Gadappa

Professor and Head,

OBGY, GMC, Aurangabad

Precautions in pregnancy?

·Last year, about 80 percent of pregnant women with COVID used to be asymptomatic. We observe that the illness is more severe in pregnancy in the current wave.

·In the first trimester ( first 8 weeks of pregnancy), it is best to avoid any radiological procedure.

·If needed, X-ray, with protective abdominal shield, after 8 weeks, is safer than CT.

·Avoid CT scan, unless it is absolutely needed. MRI is a safe option.

Doctors treating young lady patients in the child-bearing age group should take proper menstrual history and ascertain that the patient is not pregnant, before advising a CT scan or X-ray.