Covid 19 Delta outbreak: CAT scan shows how Covid attacks the lungs

A confronting CAT scan of a Covid-positive patient reveals just how viciously the disease attacks the lungs.

As they say, an image says a thousand words, and in this case, it's yelling at us to get vaccinated, says Associate Professor Dinesh Varma, a member of the Royal Australian and New Zealand College of Radiologists (RANZCR).

You'll find two images below. One shows a pair of lungs that is normal, absent Covid. The other shows a patient with extensive white blemishes in their lungs, succumbing to the virus.

"On an X-ray and CAT scan the lungs appear dark because it essentially contains air surrounded by microscopic lung tissue and blood vessels where an exchange of gases takes place as we breathe in and out," Varma told news.com.au.

"So the reason this image is dark is because it is predominantly containing air."

This scan is of a lung that hasn't been infected by Covid. The black represents air. Photo / Royal Australian and New Zealand College of Radiologists

However, when looking at the other image of a person battling Covid, their lungs are mainly white.

"Those air sacks are being replaced with infectious material caused from the virus which appear as white blotches in the lungs, that we see on chest X-rays and CAT scans which tell us that part of the lung is not normal."

Scan is of a Covid patient's lungs where the white is full of inflammatory and abnormal cells. Photo / Royal Australian and New Zealand College of Radiologists

Varma said depending on the severity of the pneumonia caused by the virus, significant portions of the lungs start to show white areas, where the lung is unable to perform its normal function, which is to exchange gases.

The Melbourne-based clinical radiologist said when a positive case gets as bad as the one in the image, they can end up needing to have mechanical ventilation, where air is pumped through an endotracheal tube.

"Those decisions are made on individual patients, depending on their severity of illness," he said.

"The level of care varies from the basic support we provide these patients who are not too unwell, to some who end up in ICU who may need to be on a ventilator.

"And if that doesn't suffice, then the next stage of treatment is to bypass the lung using Extracorporeal Membrane Oxygenation (ECMO) where the machine performs the functions of the lung and we are able to maintain their oxygen levels."

The scans show the patient with Covid is relying on less than half their lung capacity, which is incompatible with survival, according to Associate Professor Stefan Heinz, also a member of RANZCR.

Varma, who works in an emergency and trauma centre, said given Melbourne's surge of Covid cases, the past few weeks has seen an increase in Covid patients presenting with lungs similar to the one in the image.

He said this time around they are seeing many younger patients testing positive and becoming unwell, requiring hospitalisation.

"They are healthy, living a normal life and suddenly, they end up in hospital," he said, adding "no one is invincible and particularly if you are not vaccinated".

"We have to use what protection measures we have got and the only one that is proven to work is the vaccine."

Varma said the visual perception of what can happen to a body when you get Covid, particularly looking at the lungs, will hopefully convince everyone to get vaccinated.

"The saying 'one image speaks a thousand words' is so correct in this situation. It is the image people carry in their mind and they will think, 'Hang on, do I want to be that person getting that level of infection, ending up in hospital and potentially in ICU with some long term side-effects if I don't get vaccinated?

"There's enough evidence globally that those who are vaccinated even if they get the infection, the chances of them coming to hospital and getting severely unwell is very, very low."