HRCT Spectrum in Initially COVID-19 RT-PCR Negative Patients

  • Aniqua Saleem Rawalpindi Medical University
  • Lubna Meraj
  • Hira Saleem
  • Sharjeel Sarfraz Ahmed Sheikh
  • Sidra Hamid
  • Huzaifa Saleem
Keywords: COVID-19, computed tomography, RT-PCR, cross infection, CT-SS


Objective: To analyze radiological spectrum of HRCT in COVID-19 patients, clinically symptomatic but initially having negative RT-PCR.

Study Design: Prospective cross sectional descriptive study.

Place and Duration of Study: Radiology and Medicine Department, DHQ Hospital Rawalpindi, from June to November 2020

Methodology: The study included 90 patients presenting with clinical symptoms of COVID-19 but with negative RT-PCR. All patients underwent chest computed tomography (CT). Patients with positive COVID-19 RT-PCR test or serology on subsequent repeat test were included in the study. Patients having non COVID-19 HRCT features with negative RT-PCR were excluded from the study.

Results: Out of 90 symptomatic, RT-PCR negative patients, 7 had normal chest CT. According to BSTI classification, 50 patients showed classic, 11 had probable and 22 had indeterminate features. Despite supportive clinical and CT features, 17 (18.89%) patients had negative RT-PCR tests on subsequent testing. Unilateral changes were in 8 (8.9%) and bilateral in 75 (83.3%). Most common finding was mixed pattern of peripherally distributed GGN and bronchocentric nodules in 37 (41.1%) patients. Consolidations were in 19 (21.1%), pure ground glass haze in 13 (14.4%), crazy paving in 4 (4.4%), fuzzy bands and arcades in 7 (7.8%), and subtle gravitational GGH in 3 (3.3%) patients. CT-SS classified 69 (76.7%) patients as mild, 10 (11.1%) as moderate and 4 (4.4%) as severe disease.

Conclusions: HRCT with CTSS is an important tool for diagnosing and prognosticating COVID-19 infection despite negative RT-PCR, timely identifying and isolating COVID-19 cohorts preventing cross infection and also aiding in prompt symptomatic management.


1. British Society of Thoracic Imaging. Thoracic Imaging in COVID- 19 Infection; Guidance for the Reporting Radiologist British Society of Thoracic Imaging Version 2 [Internet]. Available from URL: [Cited 2020 May31].
2. Ai T, Yang Z, Hou H, Zhan C, Chen C, Lv W, et al. Correlation of chest CT and RT-PCR testing in coronavirus disease 2019 (COVID-19) in China: a report of 1014 cases. Radiology. 2020:200642.
3. Yang R, Li X, Liu H, Zhen Y, Zhang X, Xiong Q, et al. Chest CT severity score: an imaging tool for assessing severe COVID-19. Radiology: Cardiothoracic Imaging. 2020; 2(2):e200047.
4. Fang Y, Zhang H, Xie J, Lin M, Ying L, Pang P, et al. Sensitivity of chest CT for COVID-19: Comparison to RT-PCR. Radiology. 2020:200432.
5. Caruso D, Zerunian M, Polici M, Pucciarelli F, Polidori T, Rucci C, et al. Chest CT features of COVID-19 in Rome, Italy. Radiology. 2020:201237.
6. Dangis A, Gieraerts C, Bruecker YD, Janssen L, Valgaeren H, Obbels D, et al. Accuracy and reproducibility of low-dose submillisievert chest CT for the diagnosis of COVID-19. Radiol: Cardiothoracic Imaging. 2020; 2(2):e200196.
7. Brogna B, Bignardi E, Brogna C, Alberigo M, Grappone M, Megliola A, et al. Typical CT findings of COVID-19 pneumonia in patients presenting with repetitive negative RT-PCR. Radiography. 2020. doi: 10.1016/j.radi.2020.09.012.
8. Salehi S, Abedi A, Balakrishnan S, Gholamrezanezhad A. Coronavirus disease 2019 (COVID-19): A Systematic Review of Imaging Findings in 919 patients. AJR Am J Roentgenol. 2020:1-7. doi: 10.2214/AJR.20.23034.
9. BSTI. Covid-19: BSTI /BSGAR decision tool for chest imaging in patients undergoing CT for acute surgical abdomen [Internet]. Available from URL: [cited 2020 Apr 21].
10. Rubin GD, Ryerson CJ, Haramati LB, Sverzellati N, Kanne JP, Raoof S, et al. The role of chest imaging in patient management during the COVID-19 pandemic: a multinational consensus statement from the Fleischner Society. Chest. 2020: 158(1):106-116. doi:10.1016/j.chest.2020.04.003.
11. Khan AN, Umer US, Hilal K, Din NU. Stepwise Evolution in Development of Radiology Guidelines during COVID 19 Pandemic. PJMHS. 2020: 14(3); 488-91.
12. Parry AH, Wani AH, Yaseen M, Dar KA, Choh NA, Khan NA, et al. Spectrum of chest computed tomographic (CT) findings in coronavirus disease-19 (COVID-19) patients in India. Eur J Radiol. 2020; 129:109147. doi: 10.1016/j.ejrad.2020.109147.
13. Khaliq M, Raja R, Khan N, Hanif H. An Analysis of High-Resolution Computed Tomography Chest Manifestations of COVID-19 Patients in Pakistan. Cureus. 2020; 12(7): e9373. doi:10.7759/cureus.9373.
14. Zhou S, Wang Y, Zhu T, Xia L. CT features of coronavirus disease 2019 (COVID-19) pneumonia in 62 patients in Wuhan, China. AJR Am J Roentgenol. 2020;214(6):1287-94. doi: 10.2214/AJR.20.22975.
How to Cite
Saleem A, Meraj L, Saleem H, Sheikh S, Hamid S, Saleem H. HRCT Spectrum in Initially COVID-19 RT-PCR Negative Patients. JRMC [Internet]. 31Aug.2021 [cited 24Sep.2022];25(1):15-0. Available from: