Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Radiol. Jul 28, 2021; 13(7): 233-242
Published online Jul 28, 2021. doi: 10.4329/wjr.v13.i7.233
“Pulmonary target sign” as a diagnostic feature in chest computed tomography of COVID-19
Ramezan Jafari, Nematollah Jonaidi-Jafari, Houshyar Maghsoudi, Fatemeh Dehghanpoor, U Joseph Schoepf, Kyle A Ulversoy, Amin Saburi
Ramezan Jafari, Houshyar Maghsoudi, Fatemeh Dehghanpoor, Department of Radiology, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran 11151877, Iran
Ramezan Jafari, Nematollah Jonaidi-Jafari, Amin Saburi, Health Research Center, Baqiyatallah University of Medical Sciences, Tehran 11151877, Iran
U Joseph Schoepf, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC 29425, United States
Kyle A Ulversoy, Faculty of Medicine, Augusta University/University of Georgia Medical Partnership, Athens, GA 30606, United States
Amin Saburi, Chemical Injuries Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran 11151877, Iran
Author contributions: Jafari R, Jonaidi-Jafari N and Saburi A deigned the study; Jafari R, Jonaidi-Jafari N, Maghsoudi H, Dehghanpoor F collected the data; Jafari R, Jonaidi-Jafari N, Schoepf UJ, Ulversoy KA, Saburi A interpreted the data; Schoepf UJ, Ulversoy KA and Saburi A prepared the initial draft; Saburi A, Ulversoy KA and Schoepf UJ edited the final draft; all authors proved the final manuscript.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Baqiyatallah University of Medical sciences, Tehran, Iran.
Conflict-of-interest statement: Schoepf UJ receives institutional research support and / or personal fees for consulting and speaking from Bayer, Bracco, ElucidBioImagingGuerbet, Heart Flow, Inc., Keya Medical, and Siemens Healthineers. Other authors declare no conflicts of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Amin Saburi, MD, Doctor, Senior Researcher, Health Research Center, Baqiyatallah University of Medical Sciences, Mollasadra St, Vanak Sq, Tehran 11151877, Iran.
Received: January 29, 2021
Peer-review started: January 29, 2021
First decision: March 17, 2021
Revised: March 30, 2021
Accepted: June 15, 2021
Article in press: June 15, 2021
Published online: July 28, 2021

In chest computed tomography (CT) scan, bilateral peripheral multifocal ground-glass opacities, linear opacities, reversed halo sign, and crazy-paving pattern are suggestive for coronavirus disease 2019 (COVID-19) in clinically suspicious cases, but they are not specific for the diagnosis, as other viral pneumonias, like influenza and some viral pneumonia may show similar imaging findings.


To find a specific imaging feature of the disease would be a welcome guide in diagnosis and management of challenging cases.


Chest CT imaging findings of 650 patients admitted to a university Hospital in Tehran, Iran between January 2020 and July 2020 with confirmed COVID-19 infection by RT-PCR were reviewed by two expert radiologists. In addition to common non-specific imaging findings of COVID-19 pneumonia, radiologic characteristics of “pulmonary target sign” (PTS) were assessed. PTS is defined as a circular appearance of non-involved pulmonary parenchyma, which encompass a central hyperdense dot surrounded by ground-glass or alveolar opacities.


PTS were presented in 32 cases (frequency 4.9%). The location of the lesions in 31 of the 32 cases (96.8%) was peripheral, while 4 of the 31 cases had lesions both peripherally and centrally. In 25 cases, the lesions were located near the pleural surface and considered pleural based and half of the lesions (at least one lesion) were in the lower segments and lobes of the lungs. 22 cases had multiple lesions with a > 68% frequency. More than 87% of cases had an adjacent bronchovascular bundle. Ground-glass opacities were detectable adjacent or close to the lesions in 30 cases (93%) and only in 7 cases (21%) was consolidation adjacent to the lesions.


Although it is not frequent in COVID-19, familiarity with this feature may help radiologists and physicians distinguish the disease from other viral and non-infectious pneumonias in challenging cases.

Keywords: Chest computed tomography, Diagnosis, Viral pneumonia, COVID-19, Pulmonary target sign, Case report

Core Tip: In this report, a new diagnostic imaging sign in chest computed tomography of coronavirus disease 2019 cases, the “pulmonary target sign”, is reported and its characteristics are described. Previous reports are limited to a small number of case reports and this appearance is not fully described.