Cardiovascular Imaging in COVID-19
Q & A
The current COVID-19 pandemic is caused by an acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is a highly contagious virus that spreads predominantly through surface contact and aerosol. We need a set of policies and procedures devised that apply to healthcare facilities and radiology departments. The main aim of these standard operating procedures (SOP) is to, 1) achieve sufficient capacity of healthcare providers at a given time for continued operation during the pandemic, 2) support the care of patients with and without COVID-19, 3) Reduce the incidence of infection among healthcare providers by following set policies and 4) maintain the uninterrupted radiology services for the healthcare system. The FAQ’s on COVID-19 concerning the preparedness of the healthcare system and radiology departments, in particular, are as follows:
Implementation of a standard operating procedure for all radiologic imaging examinations, including cardiac scans is essential. Due to the high prevalence of asymptomatic carriers, strict adherence to standard protocols is vital to prevent exposure of radiology technicians and healthcare workers. The first step is to screen all patients entering the department for a cardiac scan with a detailed COVID-19 related history, like, fever, cough, breathing difficulty or close contact with an infected patient. Secondly, divide the radiology scanning area into two zones, with no interchange of personnel between the zones. The first zone handles patients in the preparation area and scanning room while the second zone consists of the scanning console and reporting area.
While scanning of patients with COVID-19 infection, technicians and healthcare workers use complete personal protective equipment (PPE) including N95 mask and face visor in zone 1. Personnel in zone 2 use N95 masks with face visor. Follow strict separation of zones to reduce the risk of cross-infection between healthcare workers and reducing the potential high-risk surface transmission due to contact.
That said, you may choose to perform only imperative scans, so critical results can be informed to help in the management of these patients. It would be prudent to reschedule elective examinations.
Patients presenting with either atypical symptoms or typical symptoms with equivocal ECG changes and low to intermediate risk for coronary artery disease (CAD) are routine referrals for coronary CTA. However, in the pandemic, even stable patients with high risk for CAD with symptoms are referred for coronary CTA because of prolonged contact necessary for a conventional angiography procedure compared to CT. Coronary CTA, especially with the newer faster dual source and wider detector array scanners significantly decrease the scan time with minimal need for heart rate control. It reduces the contact time between patients and healthcare workers, reducing the risk of virus transmission.
Myocarditis in COVID-19 patients can occur irrespective of the severity of COVID-19 infection. The pathophysiology for myocarditis may include inflammatory plaque rupture, prothrombotic state resulting in-stent, vessel thrombosis and systemic endothelitis. In this setting, Cardiac MRI with its superior tissue characterization helps differentiate ischemic from non-ischemic myocardial injury. CMR protocol for suspected cardiac involvement consist of cine images to look for function and wall motion, T2W images for myocardial oedema and late gadolinium-enhanced (LGE) images to assess myocardial damage. T1 and T2 parametric mapping techniques help in early detection of myocardial involvement.
Disinfection of the common touchpoints in the CT and MRI gantry rooms is vital in reducing the incidence of virus transmission to healthcare workers and other critically ill patients coming in for other imaging examinations. A UV based closed space air purifier can be used in gantry rooms. It is pertinent to do a thorough wipe down of all the parts of the machine that are being touched by the patient or the nursing staff including the tabletop, gantry and door handle with sodium hypochlorite solution. It may be prudent to follow these steps after every high-risk patient and at regular intervals of 1 hour during routine scanning.
Dr Rochita Venkataramanan,
Director & Consultant Radiologist,
Department of Clinical radiology,
Apollo Hospitals, Chennai.
Dr Pudhiavan A
Consultant Cardiothoracic Radiologist,
Department of radiology and imaging sciences,
Kovai Medical centre and hospital,