Functional Alterations Due to COVID-19 Lung Lesions-Lessons From a Multicenter V/Q Scan-Based Registry

Abstract

Purpose: In coronavirus disease 2019 (COVID-19) patients, clinical manifestations as well as chest CT lesions are variable. Lung scintigraphy allows to assess and compare the regional distribution of ventilation and perfusion throughout the lungs. Our main objective was to describe ventilation and perfusion injury by type of chest CT lesions of COVID-19 infection using V/Q SPECT/CT imaging.

Patients and methods: We explored a national registry including V/Q SPECT/CT performed during a proven acute SARS-CoV-2 infection. Chest CT findings of COVID-19 disease were classified in 3 elementary lesions: ground-glass opacities, crazy-paving (CP), and consolidation. For each type of chest CT lesions, a semiquantitative evaluation of ventilation and perfusion was visually performed using a 5-point scale score (0 = normal to 4 = absent function).

Results: V/Q SPECT/CT was performed in 145 patients recruited in 9 nuclear medicine departments. Parenchymal lesions were visible in 126 patients (86.9%). Ground-glass opacities were visible in 33 patients (22.8%) and were responsible for minimal perfusion impairment (perfusion score [mean ± SD], 0.9 ± 0.6) and moderate ventilation impairment (ventilation score, 1.7 ± 1); CP was visible in 43 patients (29.7%) and caused moderate perfusion impairment (2.1 ± 1.1) and moderate-to-severe ventilation impairment (2.5 ± 1.1); consolidation was visible in 89 patients (61.4%) and was associated with moderate perfusion impairment (2.1 ± 1) and severe ventilation impairment (3.0 ± 0.9).

Conclusions: In COVID-19 patients assessed with V/Q SPECT/CT, a large proportion demonstrated parenchymal lung lesions on CT, responsible for ventilation and perfusion injury. COVID-19-related pulmonary lesions were, in order of frequency and functional impairment, consolidations, CP, and ground-glass opacity, with typically a reverse mismatched or matched pattern.

FIGURE 1

Description of the 5-point scale used for ventilation and perfusion semiquantitative evaluation. When CT lesions were visible, perfusion and ventilation were independently evaluated using visual score. Score 0 corresponds to a normal function, 1 to a mild impairment, 2 to a moderate impairment, 3 to a severe impairment, 4 to an absent function. Images are related to pulmonary perfusion scoring related to CT lesions visible on lower lobe (green arrows).

FIGURE 2

Representation of ventilation and pulmonary perfusion alteration associated with (A) GGOs, (B) CP, and (C) consolidations visualized in patients during COVID-19 infection. Ventilation and perfusion were independently scored using 5-point scale (0 = normal function to 4 = complete amputation of the function) when pulmonary lesion was visible on CT. Green area reflect V/Q mismatch (ie, Q alteration superior to V alteration), blue area reflect reverse mismatch (ie, V alteration superior than Q alterations), and blue line correspond to match anomalies.

FIGURE 3

Illustration of GGOs visible during COVID-19 on V/Q SPECT/CT. Ground-glass opacities were visible on CT with bilateral and mixed topography (both subpleural and peribronchovascular distribution). Lesions were not responsible for a significant ventilation or perfusion impairment.

FIGURE 4

Illustration of CP visible during COVID-19 on V/Q SPECT/CT. Crazy-paving lesions predominate in posterior regions with bilateral and subpleural topography. These lesions caused mild impairment of perfusion and severe impairment of ventilation.

FIGURE 5

Illustration of consolidation visible during COVID-19 on V/Q SPECT/CT. Consolidations were visible in the anterior part of the 2 upper lobes and in the right lower lobe. We observed a severe alteration of lung perfusion with complete amputation of ventilation in these areas.