Though the vaccination process to eradicate COVID-19 has begun, encouraging a tangible sigh of relief from humanity, healthcare providers are uncovering more and more documented cases where recovered COVID-19 patients show long-term effects from the disease in the lungs, heart, immune system, brain and other organs[i]. Recently published medical literature indicates that patients hospitalized with COVID-19 commonly have lingering symptoms, sometimes for months and longer after negative COVID-19 tests[ii],[iii].
Very early on, medical imaging, particularly CT, was an important clinical diagnostic tool in highly suspected COVID-19 cases[iv].Other imaging modalities like magnetic resonance imaging (MRI) will play an important role as clinicians monitor patient recovery and search for the underlying causes of lasting COVID-19 symptoms.
As much as 30 percent of the 28 million COVID-19 cases recorded in the U.S. could lead to long-term symptoms[v]. The National Institutes of Health (NIH) is relying on MRI to help clinicians and researchers understand why and how symptoms evolve. A number of new projects are underway to help understand the underlying causes of these lasting symptoms, which can include fatigue, shortness of breath, as well as difficulty concentrating or memory problems[vi]. Concentrating heavily in the areas of neurology, cardiology and pulmonology these NIH initiatives are supported with more than a billion dollars in US Congressional funding from the Coronavirus Response and Relief Supplemental Appropriations Act of 2021[vii].
Despite the pandemic, innovation has been ongoing in the MR community with powerful new technologies, as well as artificial intelligence (AI)-based solutions so that radiology can lead the way in understanding these important clinical issues with respect to COVID-related diseases and lingering symptoms.
Evaluating the long-term cardiovascular impact of COVID-19 with cardiac MRI
Many studies have shown that COVID-19 patients with cardiovascular comorbidities were among the majority of patients with acute infections who required hospitalization[viii], but new information suggests that patients can have ongoing myocardial inflammation without having had prior cardiovascular comorbidities. Cardiac MRI is an important diagnostic tool for evaluating these patients.
In one study using cardiac MR, researchers evaluated a group of 100 post-COVID positive patients who did not have prior cardiac comorbidities. Results of the study revealed cardiac involvement in 78 patients and ongoing myocardial inflammation in 60 patients. These findings were independent of any patient pre-existing conditions, severity and overall course of the acute illness, and time from the original diagnosis[ix]. The research team echoed the actions of the NIH by suggesting these findings indicate the need for ongoing investigation of the long-term cardiovascular consequences of COVID-19.
Cardiac MR can be used to monitor a number of different heart-related conditions and changes in actively infected, as well as post-infection COVID-19 patients. Cardiac MR provides a radiation-free alternative to other modalities such as computed tomography (CT) and single photon emission computed tomography (SPECT), which are commonly used for cardiac evaluation, and it provides accurate anatomic information along with advanced soft tissue contrast[x].
Cardiac MR also offers greater contrast and image clarity than CT. Recent advances in cardiac MR have allowed for faster acquisition times and easier breath hold sequences for patients. It is recognized as a valuable clinical tool which in a single scan setting can not only perform myocardial perfusion imaging, but can also assess ventricular volumes and function, myocardial fibrosis, iron loading, flow quantification, and tissue characterization.
Cardiac MR for determining cardiac involvement in actively infected COVID-19 patients is crucial for their immediate and now longer-term prognosis. The continued use of cardiac MR can identify COVID-19 patients with possible cardiac injury and help predict progression of disease-related complications[xi].
Evaluating ongoing cognitive impairment from COVID-19 with MRI
The COVID pandemic has claimed millions of lives world-wide. Most of these deaths are due to the well-known pulmonary complications of the coronavirus, but it has become increasingly recognized that the virus also attacks the nervous system[xii]. Research is now suggesting that there may be long-term neurologic consequences in patients who survive COVID infections, including evidence of mild brain damage in many survivors[xiii].
Recent advances in neuro MR imaging using ultra-high field MR scanners enable neuroimaging with unprecedented detail, leading to better characterization of normal tissue and pathologic lesions and improved planning of treatment and monitoring of response[xiv]. The promise of ultra-high field MR imaging to evaluate post-COVID-19 patients for long-term neurological manifestations took a significant step forward with the availability of 7.0 Tesla MRI technology, such as the FDA-cleared SIGNA™ 7.0T* from GE Healthcare. The new 7.0T system provides ultra-high field imaging speed and resolution, as well as advanced diffusion, and functional brain imaging.
According to data gathered by clinicians from all parts of the world, brain abnormalities have emerged as a major feature of COVID‐19 and contributes to the growing concerns about central nervous system involvement in COVID-19[xv]. Some of the neurologic consequences of COVID-19 that have been observed can be broadly grouped into four categories: direct viral effects through neuro-invasion, meaning when the virus enters the brain directly by crossing the blood brain barrier; para-infectious immune response to the virus that manifests as coagulopathy (impaired clot formation) or as a cytokine storm, meaning when the body initiates a hyperactive immune response to the virus, to the extent it can be harmful to host cells; post-infectious delayed immune response; and complications of prolonged illness or hospitalization[xvi].
The ability for ultra-high field MRI to identify and track these and other neurologic manifestations related to COVID-19 infection is critically important as evidential data continues to be collected about the long-term cognitive effects of COVID-19 on infection survivors.
Effectively monitoring “Long COVID” patients
According to clinicians, post-acute COVID-19, or "Long COVID" is a multisystem disease that occurs after COVID-19 infection and requires follow-up clinical care with a “whole patient perspective”[xvii]. To adequately monitor the long-term health of these patients and to collect the outcomes data necessary to formulate scientific conclusions about the clinical impacts from COVID-19 infection, longitudinal MRI evaluations of critical organs such as heart, brain and lungs should be completed as required. The MRI community is supportive of these efforts and continues to advance imaging techniques for assessing organ function as well as AI-enabled solutions for image reconstruction to understand the long-term clinical impact of COVID-19.
Read more about how MRI is evaluating the lasting effects of Coronavirus:
- Assessing COVID-19 cardiac-related disease
- Imaging COVID-19 patients with neurological symptoms
- Cardiac MR in times of COVID-19
[iv] Li J, Long X, Wang X, et al. Radiology indispensable for tracking COVID-19. Diagn Interv Imaging. 2021;102(2):69-75. doi:10.1016/j.diii.2020.11.008
[viii] Teixeira R, Santos M, Gil V. COVID-19 and cardiovascular comorbidities: An update. Rev Port Cardiol. 2020;39(8):417-419. doi:10.1016/j.repc.2020.06.013
[ix] Puntmann VO, Carerj ML, Wieters I, Fahim M, Arendt C, Hoffmann J, Shchendrygina A, Escher F, Vasa-Nicotera M, Zeiher AM, Vehreschild M, Nagel E. Outcomes of Cardiovascular Magnetic Resonance Imaging in Patients Recently Recovered From Coronavirus Disease 2019 (COVID-19). JAMA Cardiol. 2020 Nov 1;5(11):1265-1273. doi: 10.1001/jamacardio.2020.3557. Erratum in: JAMA Cardiol. 2020 Nov 1;5(11):1308. PMID: 32730619; PMCID: PMC7385689.
[x] Lee SE, Nguyen C, Xie Y, et al. Recent Advances in Cardiac Magnetic Resonance Imaging. Korean Circ J. 2019;49(2):146-159. doi:10.4070/kcj.2018.0246
[xiv] Verma G, Balchandani P. Ultrahigh field MR Neuroimaging. Top Magn Reson Imaging. 2019;28(3):137-144. doi:10.1097/RMR.0000000000000210
[xv] Mankad K, Perry MD, Mirsky DM, Rossi A. COVID‐19: a primer for neuroradiologists. Neuroradiology. 2020;62(6):647‐648.