The following reflections are intended to contribute to a reasoned and non-automatic approach to the radiological performance. Sincere thanks to Ilan Rosenberg and to our Ligurian colleagues who have participated in the elaboration.

In view of the constant increase in the number of infected healthcare providers, we believe it is useful to focus our attention on the issue of citizen-citizen and citizen-provider contagion taking into account the various healthcare settings, in an attempt to limit as much as possible the possibility of citizen- provider contagion.

1. PERSONAL PROTECTIVE EQUIPMENT (PPE): the lack of PPE is well known and it might therefore be useful to identify the priorities for its use in order to ensure the protection of healthcare providers who are in direct contact with the patients. The need for PPE in activities defined as “Low Risk COVID-19” is obviously secondary to that of the technicians of medical radiology (TSRMs) who carry out “High Risk COVID-19” radiographic examinations.

2. DIAGNOSTIC PROCEDURES: it is necessary to identify pathways and procedures in patients with suspected or confirmed Covid-19 infection. In some situations, intra-hospital patient transfer may be necessary. This would require identification of passage areas, safety parameters to be applied to the patient during the transfer and PPE to be used by the involved providers.

3. HEALTH CARE PROVIDERS
Healthcare providers, who do not have an operational role, in particular in view of the substantially reduced activity, should not be present in the hospital in order to reduce possible citizen- provider contagion and because they must constitute a reserve pool required to keep the healthcare system going. This staff must be on call 24 hours a day to be contacted if needed. Their absence should not be subject to the ordinary regulation of absence from the workplace but should be justified in the spirit of the Decree of the President of the Council of Ministers (DPCM) dated 8 March 2020.
In line with the intention of minimizing the use of services that can actually be avoided, the following is a reflection on the performance of diagnostic imaging.

Imaging and the current health care management policy linked to the COVID-19 outbreak

The aim of this document is to make the readers reflect on the real and useful role of imaging in the management of Covid-19 infections with regard to safeguarding the health of citizens and healthcare providers.

The benefit-to-cost ratiobetween minimizing interpersonal contacts and the clinical utility of diagnostic imaging is the basis for the reasoning. This ”cost” acquires a great importance because of the consequences it may have on the health sector response capacities (especially if it becomes necessary to isolate healthcare providers due to confirmed infection or if they are hospitalized). The system must be aware of the overall “costs” compared to the expected benefits in order to move the providers to more appropriate tasks and to avoid negative effects on the healthcare system. Circulars outlining the approach to the diagnosis and management of external and internal procedures in patients at risk or suspected of Covid-19 infection are not always the same. Initially, the process was based on laboratory tests in the presence of suspicion, then waiting for the results and, if the outcome was positive, centralizing the patient. Subsequently, the progressive worsening of the epidemiological scenario and the inability of the hospitals to admit more patients have changed the management of the patients, who now await laboratory outcome at home or at the hospital in question depending on his/her clinical condition.

If positive, the patient can remain at home or be hospitalized again according to the clinical condition. However, the patient may develop severe respiratory failure requiring intensive care.

The current healthcare management policy linked to the Covid-19 outbreak aims at reducing contagion as much as possible, both inside and outside the hospitals. Citizen-citizen contact strongly increases the spread of the disease and causes economic damage. Citizen-healthcare provider contact also increases the spread of the disease and impairs the response capacities of the entire healthcare system. Therefore, the principle that must guide the operational choices in the management of patients suspected of Covid-19 contagion is first of all to contain patient-healthcare provider contagion without compromising the clinical outcome.

Since several circulars have included the use of traditional radiology and/or CT in the clinical- diagnostic procedure, it may be useful to reflect on the “why” of each choice in view of the efforts to contain the spread of the infection.

A) Conventional radiology

1. Using mobile computed radiography (CR) equipment in the “isolation” room (where the principle of designated isolated spaces and adequate provider PPE is applied) while awaiting the outcome of laboratory tests.
2. Using mobile digital radiography (DR) WI-FI equipment in the ”isolation” room (where the principle of designated isolated spaces and adequate provider PPE is applied).

3. In a designated diagnostic room in the Radiology Department (involves transportation of the suspected patient).
4. Using mobile equipment in triage tents (where only radiation protection is required).

There is no undivided opinion on the use of traditional radiology due to its relatively low sensitivity to the presence of interstitial pneumonia.
The approach to symptomatic patients is first of all to differentiate between Covid-19 positive and Covid-19 negative patients. This distinction is made by laboratory tests. A traditional x-ray examination cannot add elements useful for this distinction, but it increases the probability of patient-healthcare provider contagion, which is essential.

Many healthcare structures use traditional radiology in the first approach without providing convincing clinical or other answers that justify this choice.

There are different problems linked to carrying out this type of examination in a healthcare facility: • A portable device dedicated to the “isolation” room is required to avoid continuous transfers.
• If no equipment using WI-FI technology is available, two technicians are required: one for carrying out the examination using adequate PPE and the other to ensure a correct and isolated transfer of the cassette.

• If no equipment using WI-FI technology is available, an adequate transfer to the processor of the cassette, which has been in contact with the patient, must be provided (located in the Radiology Department) (see example of the path below).
• Adequate patient protection.

• Greater consumption of PPE.
• Radiation protection: if the examination is carried out in room 0, nurses and medical staff present inside the room must wear lead aprons to limit infection and radiation or move out of the room after PPE disposal. If the radiological examination takes place in a triage tent, the rules concerning minimum requirements for radiation protection are not followed.

Example of a radiological diagnostic procedure:

TSRM 1 in charge of the practical performance of the x-ray examination must follow the same dressing procedure provided by the current directives for the physician and nurse assisting the patient in room 0 and TSRM 2 in charge of the management of the x-ray cassette after the execution phase. TSRM 2 must have material for disinfecting the cassette, at least two pairs of gloves and a sheet on which to place the disinfected cassette. Digital devices using WI-FI cassettes are preferable as they allow management of (DICOM) data using the (PACS) for reporting without transport of the x-ray cassette.

Portable non-WI-FI equipment: The x-ray cassette must be wrapped in radiolucent insulating material. If no dedicated material is available a resistant nylon bag can be used. When the x-ray has been taken, TSRM 1, who has taken the x-ray, uncovers the cassette by partially removing the nylon bag with the utmost care to avoid direct contact with the cassette. TSRM 1 hands the cassette to TSRM 2 who removes the cassette from the protective wrapping and disinfects it. TSRM 2 places the cassette on the clean sheet, removes the used gloves that must be thrown into an appropriate container, puts on a second pair of gloves, disinfects the cassette again and goes to the Department of Radiology to process the images. The equipment and the WI-FI box, if any, must be disinfected with “Farmecol (alcohol based) or” Bionil “(chlorine based).

B) CT

1. Facilities with only one CT scanner.
2. Facilities with two or more CT scanners.
3. Mobile CT to be added to the dedicated Covid-19 reception facility.

CT presents a sensitivity of 95% and can be useful for the diagnosis of viral pneumonia (also COVID-19) as it is based on indicative imaging patterns. However, specificity is reduced and Covid-19 is not distinguished from other viral pneumonias. To date, the gold standard for a certain diagnosis of Covid-19 is a laboratory test.

Digital Imaging and COmmunications in Medicine

Picture archiving and communication system

CT has been used in some centers and can be used in the event that there is a scarce availability of Covid-19 test kits or in the event of a discrepancy between the result of the swab and the clinical condition. CT may identify suspected patients with interstitial pneumonia and lead to containment of potential transmission through isolation.

In order to reduce as much as possible the contagion in the centers which have more than one CT scanner, one of these could be dedicated to suspected Covid-19 patients.
The concept of isolation is even more conspicuous if the healthcare structure opts for a mobile CT in the reception facility.