Significance of chest computed tomography (CT) in COVID-19 pneumonia in obstetrics: a case report.

A pregnant 34-year-old woman was taken to our hospital in the clinical condition of mechanical ventilation (dependence on oxygen was 60%). On admission: SpO2 was 83% with a single decline episode to 68%, laboratory tests showed high CRP 46,58 mg/L, ERS 91 mm/h, IL-6 36,58 pgr/mL, initial RT-PCR test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was negative, pregnancy 28-29 weeks.

CT examinations were performed using a multi-detector CT scanner with 64 channels. The detailed parameters were: 120 kVp tube voltage, 78 mAs tube current (at the first examination), lung reconstruction algorithm, 1 mm slice thickness, 1 mm reconstruction interval. CT was performed using a low-dose protocol and personal radiation protection equipment to optimize the protection and safety of the fetus in accordance with Radiation Safety Standards [28,19].

On chest CT at the first examination we can see multiple bilateral ground-glass opacities (GGO) in the front fields predominantly (Fig.1a), consolidative opacities and air bronchogram in the lower lobes mostly (Fig.1b).

About 50% of lung parenchyma was affected bilaterally.

Follow CT - surveys in 19 and 23 days showed appearance of clear interlobular septal thickening and visible intralobular lines (“crazy-paving” pattern) (Fig.2).

In the upper right lobe, a central ground-glass opacity surrounded by a denser consolidation of annular shape was also noticed which was interpreted as an emerging atoll sign (Fig.3a, Fig.3b).

Fibrous stripes and subpleural lines were also found in the lower lobes (Fig.4a, Fig.4b).

Background

At the end of December in 2019 a new virus started in Wuhan, China, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and had a wide spreading all over the world. This infectious disease is known internationally as COVID-19. In Russia we faced these challenges in March 2019, when a lot of new cases were registered and high level of the infection was achieved in April – May 2020.

Clinical Perspective

Most patients affected by COVID-19 have  fever, dry cough, myalgia or fatigue,
others may not have any clinical symptoms. Patients with severe ARDS require mechanical ventilation  for improvement respiratory function. In pregnant women  with severe ARDS  it is very important to evaluate condition of mother’s vital functions  and condition of fetus, considering gestational age  and solve the issue of urgent delivery. 

As in our case, on admission it was decided to refuse urgent delivery, perform complex intensive care, including antibacterial, antiviral therapy, control of the laboratory indicators and condition of mother and fetus. However considering extremely serious condition and negative dynamics on the 5th day of hospitalization, urgent childbirth was performed with the use of Cesarean section  at 29-30 gestational  weeks due to mother’s acute severe medical conditions: hypotension 90 and 50 mm Hg., tachycardia up to 120 bpm, sharp increase IL 6 -19820 pg/ml (normal value <5,9 pgr/ml), and leucocyte blood formulae shift to new forms.

The caesarean section was performed without complications.

Apgar Score for Newborn Health Assessment was 5-7. The child's condition was assessed as satisfactory according to the gestational age. The child had a negative RT-PCR test for SARS-CoV-2 after birth.

Imaging Perspective

CT- examination is necessary in definition of COVID-19 pneumonia, there are some significant specific signs that help diagnose, such as ground-glass opacity on the initial examinations preferably, consolidation, crazy paving and fibrous stripes, that become the dominant CT –keys on the following surveys (in 2 weeks approximately).

Outcome

Chest CT plays an important role in the diagnosis of new type of viral pneumonia, especially supporting early diagnosis in case when RT-PCR may not yet be positive. CT – specific signs for COVID-19 pneumonia help not only in early definition of diagnosis, as well correct interpretation of these imagings influence on therapeutic options, prognosis and therapy planning, as it helps to evaluate the severity extent of lung’s involvement and understand how to monitor specialized patients, for example as in our case, to continue observation of pregnant woman or perform emergency delivery.

As the result, the woman and the child checked out of  the hospital in a satisfactory condition.