CT provides best diagnosis for COVID-19

February 26, 2020

OAK BROOK, Ill. (February 26, 2020) - In a study of more than 1,000 patients published in the journal Radiology, chest CT outperformed lab testing in the diagnosis of 2019 novel coronavirus disease (COVID-19). The researchers concluded that CT should be used as the primary screening tool for COVID-19.

In the absence of specific therapeutic drugs or vaccines for COVID-19, it is essential to detect the disease at an early stage and immediately isolate an infected patient from the healthy population.

According to the latest guidelines published by the Chinese government, the diagnosis of COVID-19 must be confirmed by reverse-transcription polymerase chain reaction (RT-PCR) or gene sequencing for respiratory or blood specimens, as the key indicator for hospitalization. However, with limitations of sample collection and transportation, as well as kit performance, the total positive rate of RT-PCR for throat swab samples has been reported to be about 30% to 60% at initial presentation.

In the current public health emergency, the low sensitivity of RT-PCR implies that a large number of COVID-19 patients won't be identified quickly and may not receive appropriate treatment. In addition, given the highly contagious nature of the virus, they carry a risk of infecting a larger population.

"Early diagnosis of COVID-19 is crucial for disease treatment and control. Compared to RT-PCR, chest CT imaging may be a more reliable, practical and rapid method to diagnose and assess COVID-19, especially in the epidemic area," the authors wrote.

Chest CT, a routine imaging tool for pneumonia diagnosis, is fast and relatively easy to perform. Recent research found that the sensitivity of CT for COVID-19 infection was 98% compared to RT-PCR sensitivity of 71%.

For the current study, researchers at Tongji Hospital in Wuhan, China, set out to investigate the diagnostic value and consistency of chest CT imaging in comparison to RT-PCR assay in COVID-19.

Included in the study were 1,014 patients who underwent both chest CT and RT-PCR tests between January 6 and February 6, 2020. With RT-PCR as reference standard, the performance of chest CT in diagnosing COVID-19 was assessed. For patients with multiple RT-PCR assays, the dynamic conversion of RT-PCR test results (negative to positive, and positive to negative, respectively) was also analyzed as compared with serial chest CT scans.

The results showed that 601 patients (59%) had positive RT-PCR results, and 888 (88%) had positive chest CT scans. The sensitivity of chest CT in suggesting COVID-19 was 97%, based on positive RT-PCR results. In patients with negative RT-PCR results, 75% (308 of 413 patients) had positive chest CT findings. Of these, 48% were considered as highly likely cases, with 33% as probable cases. By analysis of serial RT-PCR assays and CT scans, the interval between the initial negative to positive RT-PCR results was 4 to 8 days.

"About 81% of the patients with negative RT-PCR results but positive chest CT scans were re-classified as highly likely or probable cases with COVID-19, by the comprehensive analysis of clinical symptoms, typical CT manifestations and dynamic CT follow-ups," the authors wrote.
-end-
Find all the latest Radiology and Radiology: Cardiothoracic Imaging COVID-19 research at Special Focus: COVID-19.

"Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Cases," Tao Ai, M.D., Ph.D., Zhenlu Yang, M.D., Ph.D., Hongyan Hou, M.D., Chenao Zhan, M.D., Chong Chen, M.D., Wenzhi Lv, Qian Tao, Ph.D., Ziyong Sun, M.D., Liming Xia, M.D., Ph.D.

Radiology is edited by David A. Bluemke, M.D., Ph.D., University of Wisconsin School of Medicine and Public Health, Madison, Wis., and owned and published by the Radiological Society of North America, Inc. (https://pubs.rsna.org/journal/radiology)

RSNA is an association of radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Ill. (RSNA.org)

For patient-friendly information on chest CT, visit RadiologyInfo.org.

Radiological Society of North America

Related Ct Scans Articles from Brightsurf:

Stroke scans could reveal COVID-19 infection
New research from King's College London has found that COVID-19 may be diagnosed on the same emergency scans intended to diagnose stroke.

Radiation from CT scans associated with increased risk for cancer
A new study in JNCI Cancer Spectrum finds that exposure to radiation from CT scans is associated with higher risks of developing thyroid cancer and leukemia.

Worrisome increase in some medical scans during pregnancy
Use of medical imaging during pregnancy increased significantly in the United States, a new study has found, with nearly a four-fold rise over the last two decades in the number of women undergoing computed tomography (CT) scans, which expose mothers and fetuses to radiation.

Alzheimer's diagnosis, management improved by brain scans
A first-of-its-kind national study has found that a form of brain imaging that detects Alzheimer's-related 'plaques' significantly influenced clinical management of patients with mild cognitive impairment and dementia.

Radiation doses from CT scans should be more consistent, say experts
Large differences in radiation doses used for CT scans are mainly due to how the scanners are used by medical staff rather than differences in the patients scanned or the machines used, finds a study in The BMJ today.

MRI scans shows promise in predicting dementia
Doctors may one day be able to gauge a patient's risk of dementia with an MRI scan, according to a new study from Washington University School of Medicine in St.

CT scans may increase the risk of brain cancer
A new study in the Journal of the National Cancer Institute suggests that CT scans, commonly used in medical imaging, may increase the risk of brain tumors.

Why we need erasable MRI scans
Gas-filled protein structures could one day be used as 'erasable' contrast agents for MRI scans.

Brain scans may help diagnose neurological, psychiatric disorders
A new study shows that individual brain networks are remarkably stable from day to day and while undertaking different tasks, suggesting that they could potentially form the basis of diagnostic tests for brain disorders or diseases.

CT scans reveal new muscles in horseshoe crab appendages
Digital dissection shows that two horseshoe crab appendages -- the pushing leg and the male pedipalp -- each have one more muscle than had been thought, according to a study published Feb.

Read More: Ct Scans News and Ct Scans Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.