NOTICE TO HEALTHCARE PROVIDERS: COVID-19 RSNA IMAGING GUIDANCE
March 19, 2020
Dear Healthcare Providers, Hospital and Ancillary Partners,
These are unprecedented times for our country, our city, and certainly our healthcare system. Throughout rapidly evolving circumstances surrounding COVID-19 and the global response to the virus outbreak, our highest priority remains—to care for patients, serve our partners and take care of our teams.
In efforts to slow the spread of the virus and provide best practices as it pertains to COVID-19 and imaging guidelines, Desert Radiology is strongly endorsing adherence to the Radiological Society of North America’s recommended imaging guidelines for suspected or proven COVID-19 cases, by all hospital and ancillary partners.
In the early weeks of the COVID pandemic spread in the US, there has been some early reports of distinct CT patterns of findings in the Wuhan population. While there are some general trends in CT, there are no pathognomy findings that would supplant RT-PCR testing as the primary screening and diagnostic tool. Early authors have tried to stress this overall non-specific nature of CT, and emphasize that imaging plays little, if any, role in the diagnosis and management of COVID patients. For illustration, consider the two possible outcomes of CT:
- If the CT is negative, this has not been enough to exclude COVID in nascent infections. Therefore, a negative CT does NOT help.
- If the CT is positive, the pattern is reported 80-90% sensitivity, and only a 60-70% specificity from tertiary referral centers. These numbers are not enough for either a screening or exclusionary test. CT findings are non-specific, with marked overlap with other etiologies). Therefore, an abnormal CT does NOT help. Even in known COVID patients, CT is unlikely to alter medical management because care is primarily supportive.
Debatably, the only reason to perform CT in a patient with initially suspected COVID is to exclude other diagnoses in the setting of acutely worsening status over the next day or days. This would help to detect complicated pneumonia from other etiologies (i.e. fungal, TB, septic emboli, etc). These patients should have theoretically already been excluded clinically or by RT-PCR.
Following current best practices, the recommendation is to screen for risk factors (possible exposure and travel), pairing it with any clinical features of lower respiratory tract involvement. Clinical suspicion on these grounds alone should be enough to decide if RT-PCR testing is needed.
If required, portable CXR could be obtained to screen for alternative diagnoses. If the CXR is negative, CT is not indicated. If the CXR shows lower respiratory involvement, the CT is also not likely indicated as it will not alter management. CT should be reserved for cases that show acute near-term worsening, which may suggest an alternative diagnosis.
Additionally, this misappropriation of CT in diagnosis of COVID generates potential risk of over imaging. First, if we take into consideration that equipment and rooms may require downtimes of 30-60 minutes following a suspected and/or confirmed COVID-19 patient is scanned. This required downtime will greatly impact CT throughput for many patients, including those requiring CT for very critical diagnoses.
Secondly, there is an amplified risk of increased exposure involved with overutilization of CT, and other imaging in general, not only to other patients being scanned, but to all personnel along the imaging chain. This includes but would not be limited to transporters, technologists, and clerical staff.
At this moment, we will not be able to guarantee what additional counter measures collectively we may need to employ over the next few days, weeks, and months. We must bear in mind that as more support personnel convert to COVID-19 patients, the task of maintaining health care delivery as a system will become increasingly more challenging.
We are deeply grateful for your continued support. It is imperative, now more than ever, that we work together to safeguard not only our patients, but also our physician and clinical support teams. Collectively we must do whatever is necessary to help to minimize the impact of COVID-19 in our community.
Kevin C. Hyer, M.D.
Presdient / Medical Director
Executive Vice President / CEO