The coronavirus disease 2019 (COVID-19) pandemic poses a major challenge to health systems and hospitals worldwide [1] . Radiology departments prepare for the surge of COVID-19 patients by employing policies and procedures to ensure sufficient capacity for continued operation, to support the care of COVID-19 patients, and to maintain radiologic services for the entirety of the hospital and health system [2] . Although there is literature on how to prepare a radiology department for operation during the COVID-19 crisis, the postcrisis situation has not yet been addressed. The aim of this communication is to increase awareness about the projected aftermath and consequences of the COVID-19 crisis on a radiology department, and to present possible solutions.
In response to the ongoing COVID-19 crisis, healthcare providers outside the radiology department are suspending most non-urgent elective care. This policy aims to prevent highrisk patients from being infected with COVID-19, to minimize the risk of COVID-19 spreading in hospitals to other patients and healthcare workers, and to secure bed and intensive care capacity for both patients with respiratory distress due to COVID-19 and patients with other life-threatening medical conditions. Examples of elective care that have been postponed in our tertiary care center are the treatment of most patients with benign pathology and patients with malignant tumors in whom the health risk of delaying treatment 2 outweighs that of incurring a COVID-19 infection. The majority of solid organ and hematopoietic stem cell transplantation programs and most outpatient visits have also been cancelled. Because imaging plays a crucial role in many of these elective care processes, many radiologic procedures are also postponed. Another important issue is that most hospitals aim to strictly isolate patients with COVID-19 from patients and healthcare workers without COVID-19. In addition, many people with COVID-19 show no symptoms but are still able to infect others [3] . Therefore, there is reluctance to continue providing non-urgent elective radiologic services to asymptomatic individuals. In fact, doing so would contradict a hospital's strategy to minimize the risk of COVID-19 spreading in hospitals to other patients and healthcare workers. Consequently, it is inevitable that a large reservoir of radiologic procedures will accumulate.
After hospitals have overcome the peak load of COVID-19 patients and hospital capacities start to normalize, elective care processes will eventually be reinitiated. Elective care that has been postponed will most likely be caught up at a rapid pace after the ban has been lifted due to pent-up demand and clinical need. For example, further delaying some types of elective care may cause patient harm in cancer patients in whom chemotherapy and/or elective surgery have been postponed [4] , disease progression with prognostic and treatment consequences may occur. Therefore, the anticipated wave of radiologic procedures may overwhelm normal capacity of a radiology department. A radiology department will need to process this backlog of radiologic procedures in a timely manner, because further treatment delays may be detrimental.
The current state of the radiology department 3 Our tertiary care center is located in Western Europe and provides healthcare services to more than 2 million people. Because of the COVID-19 crisis, the number of radiologic procedures in our institution has decreased with a factor of at least three to four and this situation may continue for several weeks to months, which may lead to increased need for imaging capacity in post-crisis period. Due to pre-existing budget cuts and lost income during the COVID-19 crisis, it is not a viable option to hire more staff to process the backlog of radiologic procedures. Shortage of staff capacity relative to the workload may contribute to radiologist burnout [5] in the post COVID-19 period. Therefore, creative solutions with existing resources have to be realized. Advantages of the current COVID-19 crisis for a radiology department, at least ours, are the availability of time to implement solutions and a potentially increased willingness of the entire radiology team to comply with proposed measures compared to measures taken during a non-crisis setting [6] .
Based on the aforementioned underpinnings, several measures will be implemented in our department after the COVID-19 crisis. First, MRI represents a large proportion of the total volume of procedures in our department, and is relatively time-consuming both in terms of image acquisition and interpretation. Therefore, current MRI protocols will be replaced with abbreviated MRI protocols when possible. The diagnostic non-inferiority of abbreviated MRI protocols compared to more extensive MRI protocols has already been shown in several clinical settings and body regions [7, 8] . Second, at present the majority of radiologists in our department exclusively works in one area of subspecialization (e.g. neuroradiology, chest radiology, abdominal radiology, musculoskeletal radiology, etc.). However, this type of work distribution is rather inefficient when some sections will experience higher peak workloads than others in the aftermath of the COVID-19 crisis. Based on the registration of radiologic 4 procedures that have been cancelled since the COVID-19 outbreak and available staff, subspecialty sections have been identified that are vulnerable to work overloads.
Subsequently, radiologists with other subspecializations have been distributed among these vulnerable sections on a voluntary basis and given the task to refresh their knowledge to be able to independently perform basic or common procedures in these sections. Examples of basic or common procedures are conventional radiography and acute CT (e.g. pulmonary embolism) in chest radiology, and abdominal ultrasonography and oncologic CT in abdominal radiology. Given the decreased workload during the ongoing COVID-19 crisis, these cross-over radiologists will have time to refresh their knowledge by performing procedures under the supervision of subspecialty radiologists from each section. The duration of these in-house "mini-fellowship" constructions will depend on the duration of the COVID-19 crisis. If the COVID-19 crisis continues for a longer period, both the reservoir of radiologic procedures and the operational capability of the cross-over radiologists will increase. Therefore, we believe these in-house "mini-fellowships" to be beneficial regardless of the duration of the COVID-19 crisis. Third, our department provides a 1-week radiology internship that is compulsory to medical students in our university. Under normal circumstances, medical students are involved in radiologic procedures, such as supervised plain film reading and attending ultrasonographic examinations. This requires valuable time of radiologists and radiology residents that will become even scarcer after the COVID-19 crisis. Therefore, staff radiologists, fellows, and residents will prepare self-educational material that can be used by medical students until workload normalizes to a level comparable to that before the COVID-19 outbreak.
This communication addressed the projected aftermath and consequences of the COVID-19 crisis on a radiology department. It was demonstrated how our tertiary care radiology department prepares to process the large reservoir of radiologic procedures after the COVID-19 crisis in a timely manner. Although some of these solutions may not be applicable to other institutions, some of them may, and it is hoped that this communication will create awareness and stimulate discussions on how to prepare a radiology department for the crisis after the currently ongoing COVID-19 crisis.