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Experts stress on radiology preparedness for COVID 19

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Like any other health professionals, radiologists are doing their bit to safeguard their patients with limited resources.  It’s time they get ready to set protocol for preparedness during and post epidemic

In the wake of the global health crisis due to COVID-19, each and every medical practitioner has been urged to combat this deadly disease. The radiology community is currently doing its bit in contributing to this cause by extending their services for diagnosis as and when required. However, the fraternity is currently getting braced for a shift in their roles from the diagnostic capability to preparedness.

According to Radiological Society of North America (RSNA), radiology preparedness is a set of policies and procedures directly applicable to imaging departments

  1. to achieve sufficient capacity for continued operation during a healthcare emergency of unprecedented proportions,
  2. to support the care of patients with COVID-19,
  3. to maintain radiologic diagnostic and interventional support for the entirety of the hospital and health system. Because of varying infection control policies (both nationally and regionally), steps for radiology preparedness for COVID-19 will vary between institutions and clinics.

In this article, we explore how radiologists in India are braced for this emergency.

The relevance of radiology in COVID-19

IN early December and January when the COVID-19 outbreak happened in China, chest CT findings (eg, peripheral ground-glass infiltrates and/or organising pneumonia) temporarily became part of their official diagnostic criteria of COVID-19 as a surrogate for viral nucleic acid testing. With improved disease understanding and the developing of rapid testing kits, chest CT findings are no longer part of the diagnostic criteria for COVID-19.

By the time the pandemic hit India, we were well-prepared with testing kits. Therefore, radiology has no big role in confirming cases of COVID 19 positive cases. However,  Chest X-Ray and CT scans are still used as an adjunct in diagnosing some cases. Moreover, Chest CT can help at a time when there is a shortage of RT-PCR kits and the turnaround time is high.

According to Dr Sona Pungavkar, Senior Consultant Radiologist, Global Hospital, Mumbai a chest CT scan is useful in this crisis when an urgent diagnosis is required, though RT-PCR is the most effective. A chest CT scan can be read within 10 seconds, whereas a radiologist would take 15 min, at least. Also, a database could be collected from all over the world at a central point to analyse and create learnings for the future.

She mentions, “Basic chest radiograph is done for all patients as a primary modality and later for serial follow up. Worsening of serial radiographs in the form of subtle peripheral patchy opacities should be watched for further prognostication and management. Chest CT is used, when symptoms worsen in proven cases, to gauge the degree of lung involvement, which has an impact on the prognosis of these patients.”

Says Dr Amit Janu, Consultant Radiologist at Tata Memorial Hospital and Associate Professor at Homi Bhabha National Institute, Mumbai says, “CT as an investigation keeps coming in the picture where there is lack of RT-PCR test kits and turnaround time is high. Though it shows features of viral pneumonitis and some patterns common and consistently seen in patients, it can help in the assessment of severity, ruling out other alternative diagnoses, still, it’s not a confirmatory test. RT-PCR is the only test to confirm or rule out COVID-19 infection, is there or not.  Newer RT-PCR tests are easy, more accurate and less resource-intensive with a turnaround time of less than a day. The sensitivity of the test depends on various things starting from where and how the sample is collected.”

He further mentions, “In our current workflow, hospital recommendation and with the accuracy and rapidity of the RT-PCR testing, there is no need for immediate CT imaging as a screening tool for COVID-19 patients. In addition to the above, even if symptom worsening is thought to be secondary to COVID-19, imaging would not significantly alter the patient management, as current treatment consists of oxygen, symptomatic and supportive care and trails are on many antiviral and anti-inflammatory drugs to see the efficacy of any drug. With improved understanding of the disease, chest CT findings are no longer part of the diagnostic or screening criteria for COVID-19.”

Dr Deepak Patkar, President, Indian Radiological and Imaging Association, and Director, Medical Services, Head, Department of Imaging, Nanavati Superspeciality Hospital, Mumbai, points out, ”CT chest has the sensitivity and specificity ranging between 80 – 90 per cent and 60 to 70 per cent, respectively. All the present national and international guidelines defer to the use of CT for screening or diagnosis of COVID-19. Thus, imaging should be strictly reserved for cases where it will impact patient management. It provides aid where alternate causes for breathlessness or disease worsening are considered or to assess unrelated indications.”

Dr Patkar adds, “CT can also help in identifying patients with negative tests early in the disease. But these are rare cases. Also, inadvertent use of contrast injection should be avoided which will help in reducing equipment exposure. One more small addition in our protocols is to scan chest in all suspects /positive patients, even if they are coming for CT scan of some other body part so that if COVID corridor has been created and the patient is already being taken for scan, we address to the status of lung parenchymal involvement.”

According to  Dr Sona Pungavkar, Senior Consultant Radiologist, Global Hospital, Mumbai,  the positive predictive value of these typical CT findings is estimated to be 92 per cent in a population with high pretest probability for the disease (e.g., 85 per cent prevalence by RT-PCR). These findings include peripheral patchy or diffuse ground-glass densities with or without peripheral dense rim (reverse halo sign), perilobular consolidation, associated reticulations resulting in a crazy-paving pattern.

She adds, “Imaging is indicated in case of worsening of symptoms in proven cases, wherein, it will have a significant impact on patient management. It is also used to evaluate the patients to rule out an alternative diagnosis or with other related or unrelated emergent indications. Presence of lobar pneumonia, a tree in bud appearance, pleural effusions, cavitatory consolidation should raise the suspicion of a diagnosis other than COVID.”

How well is the radiology community prepared?

At a time when the frontline health workers are fighting all odds to save patients, radiologists have come up with ways to prevent the spread.

Says Dr  Patkar, “The main focus of most radiology departments in hospitals is  preparedness with intent to maintain continued operation of the imaging setup  during this  healthcare emergency along with maintaining diagnostic radiology capacity for the entire hospital.”

The radiology department of Nanavati Hospital is trying to avoid non-emergency diagnostic investigations and procedures, as far as possible. The department is encouraging clinicians to prescribe radiology investigations only when essentially needed like in emergency and semi-emergency indications like stroke, obstetrics, pulmonary thromboembolism etc., where it will affect patient management. According to Dr Patkar,  “This will serve the purpose to preserve available resources and also limit individual exposure.”

Mentions Dr Pungavkar, “Imaging will be only for those COVID 19 patients, where imaging will impact management. This will help to reduce the level of exposure to the staff occupying the department.”

She suggests that the performance of imaging is suggested at locations with less foot traffic.  The immediate waiting area outside the CT gantry room should be vacated prior to transferring the suspected or proven COVID positive patient and whenever possible, portable imaging with due protection is what she is looking out for.

Recent news on substandard PPEs from China has been doing the rounds. Around 63000 PPE kits from China would have helped the Indian government in a larger way, but faulty kits made the India government think otherwise which would have compromised the frontline caregivers.

Echoing the same, Dr Sameer Shah, said, “The radiology community is partially prepared. Supply of PPE kits and other protective measures are the key solution and it seems to be suboptimal in quantity and quality (certain reports there that imported kits from China are suboptimal in quality). This is an added cost.”

Protocols and preparedness

Various hospitals have taken a  host of measures to prevent the spread of the virus at a time when healthcare workers are more susceptible to get infected.

Nanavati Super Speciality Hospital has created proper protocols for each radiology investigation. These are in the form of flow charts and each and every step is strictly being followed. Screening and triage procedures followed at hospital entry level are reinforced by second screening history using self-declaration forms in the radiology department. Sops are followed for all positive patients which include making COVID corridors for patient transfers, minimum essential staff stationed in the department, following strict cleaning and disinfection guidelines using hypochlorite and alcohol-based solutions, fixed slots for positive patients along with personnel. All procedures are withheld for one hour after cleaning is done.

The hospital has further ensured that there are no chairs in the waiting area as an attempt to avoid unnecessary crowding. The staff has been reduced to almost one third to preserve resources. The radiology department in the hospital has provided remote access by providing home workstations to radiologists wherever feasible.

Says Dr Patkar, “Few key points to be kept in mid are assure minimum staff exposure, machine and machine room preparation, rapid scanning protocols, optimise the use of the most valuable resource at this point of time which is staff and PPE and also to assure proper terminal cleaning or machine as well as department after the scan is done.”

Dr Patkar also recommends the use of portable CT scanners for COVID patients, if possible. Assigning one dedicated portable radiography machine and USG machines, if possible is also a good alternative.

Says Dr Sona, “Performance of imaging is suggested at locations with less foot traffic. Vacating the immediate waiting area outside the CT gantry room, prior to transferring the suspected or proven COVID positive patient.  Whenever possible, portable imaging with due protection is suggested.”

Teleradiology, a medium

At this trying time, social distancing is being strictly followed globally and teleradiology is playing a big role. Patients in remote locations can get doctor’s advice with the help of telemedicine. Also, there is minimal physical contact between doctors and patients.

Says Dr Janu  “The most common imaging used in COVID-19 is chest X-ray and chest CT scan which doesn’t require on-site radiologist if standard protocols for imaging are followed up. In such a situation, teleradiology has come to the rescue with doctors being able to read their scans and give expert opinions even when they are self-quarantined due to exposure. In India, we have machines in tier iii cities and remote parts of the country, however, most radiologists are based in metros and tier two cities and teleradiology connect that bridge.

Dr Patkar says, “As the president of Indian Radiology and Imaging Association, I would encourage all my fellow radiologists to support teleradiology services. Teleradiology has proved to be a key enabler in this battle against the coronavirus. In the emergency setting, teleradiology ensures that when a scan is performed, it can be reported immediately and treatment decisions may be made right away. This novel technique is ideal for the present pandemic where the radiologist can provide their expert services without any possible risk of exposure.”

Dr Pungavkar mentions, “Teleradiology services can be set up to evaluate the imaging of patients in remote areas. This will help in identifying and shifting those patients who require tertiary care services. Another advantage of teleradiology services in the wake of this pandemic is that it reduces the exposure of the disease to medical and paramedical personnel, such as transcriptionists in the medical centres and hospitals.”

AI and deep learning

Many researchers these days are utilising AI and deep learning mechanisms to develop various solutions to combat COVID-19. Radiologists too are utilising AI to enhance diagnostic capabilities.

Says Dr Janu, “Basically in deep learning, volumetric CT scans are processed, the first lung is extracted and segmentation is done and then processed image passed through the AI tool the predictions. Once the deep learning model is trained, it is very fast to process a new testing exam to the unimaginable fast processing time for a CT exam is around 4.51 seconds!! On a high graphic workstation.  The accuracy of various models is between 80 to 90 per cent.”

Dr Janu further says, “A robust deep learning model is needed for the hour, so we use convolutional networks to distinguish COVID-19 from other community-acquired pneumonia.”

“AI can help address the issue of triaging the radiology investigation, as per the clinical priorities. It can actually help categorically identify features suspicious for COVID-19. Also, it will provide reliable support to the radiologists with this ever-increasing patient numbers and therefore an increasing number of radiology investigations”, sums up Dr Patkar.

Going forward, hospitals and radiology department need to establish protocols for handling patient load in case of advanced spread and even after hospitals resume services.

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