Chinese health authorities are starting to look closely at CT scans of patients with coronavirus in the Hubei province, where the deadly virus was first detected.
The lungs are an important place to start, because patients who present with symptoms of the virus are proving to share a common feature – white patches called “ground glass,” which signal fluid in the lungs.
CT scans are not as thorough as blood tests, but doctors in Wuhan are running short on blood test kits, The New York Times has reported.
So a new report on the JAMA Network medical journal site gives some fascinating insights into what some of the first detectable coronavirus symptoms are.
The report focuses on 138 hospitalised coronavirus patients in Wuhan and explores what physicians are looking for – and finding – in CT scans of these patients.
In a normal healthy person, lungs will appear black on a CT scan.
However, the CT scans of coronavirus patients are showing up white flecks, referred to by radiologists as “ground glass opacity.”
These flecks aren’t specific to coronavirus patients – they can show up in the scans of people with varying types of infections – but there is one significant difference.
The study has determined that the white flecks of coronavirus scans extend all the way out to the edges of the lungs, which is rarer.
The same phenomenon showed up in CT scans of patients with SARS and MERS, the Middle East respiratory syndrome.
Scans of a 52-year-old patient who was on the mend showed the white patches significantly reduced after several weeks.
Another common indicator is the “ground glass halo”, with white patches surrounding a small nodule.
A 27-year-old woman from Wuhan presented to hospital with a fever and cough, with CT scans revealing the halo effect.
As the woman’s condition worsened, the nodule became larger.
The other common effect is the “crazy paving pattern,” which one researcher described as looking like a “cobblestone road” – another feature that had emerged in SARS and MERS cases.
The fourth common pattern was a mesh-like pattern called a reticulation, which was found in the scan of a 75-year-old man from Wuhan.
The mesh pattern is a common sign of acute respiratory distress syndrome or ARDS.
A recent study in the medical journal The Lancet concluded that coronavirus can lead to ARDS, which is often fatal.
Studies of the 138 patients lead researchers to conclude that there were three essential components to a coronavirus diagnosis: a fever/cough, the ground glass patches in both lungs in a CT scan, and a history of exposure to people from Wuhan.
However, researchers added that they could not rely solely on CT scans for diagnosis.
Several other factors need to be taken into account, including symptoms, clinical history and laboratory tests.