Thoracic Computed Tomography to Assess ARDS and COVID-19 Lungs

Abstract

This review was designed to discuss the role of thoracic-computed tomography (CT) in the evaluation and treatment of patients with ARDS and COVID-19 lung disease. Non-aerated lungs characterize the ARDS lungs, compared to normal lungs in the lowermost lung regions, compressive atelectasis. Heterogenous ARDS lungs have a tomographic vertical gradient characterized by progressively more aerated lung tissues from the gravity-dependent to gravity-independent lungs levels. The application of positive pressure ventilation to these heterogeneous ARDS lungs provides some areas of high shear stress, others of tidal hyperdistension or tidal recruitment that increases the chances of appearance and perpetuation of ventilator-induced lung injury. Other than helping to the correct diagnosis of ARDS, thoracic-computed tomography can help to the adjustments of PEEP, ideal tidal volume, and a better choice of patient position during invasive mechanical ventilation. Thoracic tomography can also help detect possible intra-thoracic complications and in the follow-up of the ARDS patients’ evolution during their hospital stay. In COVID-19 patients, thoracic-computed tomography was the most sensitive imaging technique for diagnosing pulmonary involvement. The most common finding is diffuse pulmonary infiltrates, ranging from ground-glass opacities to parenchymal consolidations, especially in the lower portions of the lungs’ periphery. Tomographic lung volume loss was associated with an increased risk for oxygenation support and patient intubation and the use of invasive mechanical ventilation. Pulmonary dual-energy angio-tomography in COVID-19 patients showed a significant number of pulmonary ischemic areas even in the absence of visible pulmonary arterial thrombosis, which may reflect micro-thrombosis associated with COVID-19 pneumonia. A greater thoracic tomography severity score in ARDS was independently related to poor outcomes.

Prevalence and clinical implications of abnormal body composition phenotypes in patients with COVID-19: a systematic review

“…Given the availability of these scans in the medical records of patients with COVID-19, CT imaging has been opportunistically used for body composition assessment. Although the third lumbar vertebra (L3) is the reference site for this purpose ( 108 ); this landmark is not readily available in COVID-19 patients ( 109 ). In this review, only 13 of 45 studies evaluated body composition abnormalities using a single image at the L3 level.…”

State of the art: Monitoring of the respiratory system during veno-venous extracorporeal membrane oxygenation

“…102 Hounsfield unit filters can be used to identify voxels of complete collapse, partial aeration, normal aeration and hyperinflation in a quantitative manner. 103,104 However, this requires post-processing and filtering to achieve accurate results. Quantitative CT can be acquired at different airway pressure levels to assess the recruitability of lung and guide early ventilation strategies during ECMO.…”

Progress in Biosensors for the Point-of-Care Diagnosis of COVID-19

“…An increase in inflammatory cytokines and the appearance of symptoms after inflammation is also typical for COVID-19 [ 24 , 25 , 26 , 27 , 28 ]. The exact diagnosis can be based on various techniques and instruments, including the techniques locating damaged tissues such as tomography and sonography [ 29 , 30 , 31 ] and molecular biology methods such as polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) in their reverse transcriptase [ 32 , 33 , 34 , 35 , 36 , 37 , 38 ]. Immunochemical methods such as enzyme-linked immunosorbent assay (ELISA) for the detection of specific antibodies or the presence of the COVID antigen can also be used [ 39 , 40 , 41 , 42 ].…”