Zhongnan Hospital Zhang Xiaochun: CT as a new crown pneumonia diagnosis basis is feasible?

“CT imaging is highly recommended as the main basis for the current 2019nCoV pneumonia (diagnosis). On February 3rd, Zhang Xiaochun, deputy director of the imaging department of Wuhan University Zhongnan Hospital, which is on the front line of the fight against the epidemic, published a call in friends’ circle, sparking widespread discussion. As of 24 february, more than 34,000 people had been confirmed with new coronary pneumonia and more than 27,000 suspected infections.

(Original title: Interview with Zhang Xiaochun of Zhongnan Hospital: Is CT feasible as the basis for diagnosis of new coronal pneumonia?) )

Journalist Bao Yuhazi Correspondent Gao Xiang

Zhongnan Hospital Zhang Xiaochun: CT as a new crown pneumonia diagnosis basis is feasible?

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Is CT imaging necessary in the current situation as an important basis for nucleic acid-negative suspected patient screening, clinical diagnosis and efficacy monitoring? What are the advantages of CT imaging compared to nucleic acid detection, and what challenges do they present?

On February 6th, with these questions, the journalist interviewed Dr. Zhang Xiaochun.

Previously, Zhang Xiaochun through WeChat friends circle said: in the key affected areas of Hubei Province or Wuhan, should be suspected patients or with a history of close contact with the confirmed patients for the removal of ct images of the lungs, as the current 2019nCoV pneumonia screening as the main basis; Calls are called for isolation treatment for people who are asymptomatic or nucleic acid-tested negative but have a positive CT image to prevent family aggregation infections and allow the outbreak to spread further.

In the interview, she told reporters that she had been misunderstood since the release of the circle of friends. “I mean don’t wait for the results of nucleic acid testing, perform nucleic acid testing at the same time, perform a lung CT imaging, the lung CT presents acute inflammation signs of patients, in accordance with the “suspected from there” principle of early treatment. The nucleic acid testing is still the gold standard of the final pathogen diagnosis, and the ethnography evidence is irreplaceable and unquestionable. “

“Nucleic acid testing currently has some limitations, such as the problem of false negatives. Zhang Xiaochun pointed out that this is mainly due to several reasons, first, the current nucleic acid kit research and development time is particularly short, product stability is not high; Many sample rhunos are recruited from various medical positions, not everyone is professional, each person samples the operation is different, but also lead to sampling error.

Zhang’s suggestion has been supported by many medical peers. Zhang Yuxuan, director of clinical radiotherapy for chest tumors at MD Anderson Cancer Center in the United States, also wrote, “The use of CT as a new standard for diagnosis of pneumonia is urgent.” “

According to the above article, nucleic acid testing has the following limitations: when the viral load is not high, its detection rate is relatively low, and thus false negative; Plus the quality of new products from major companies needs to be studied and improved;

Zhang Told reporters that she made such a call, based on the focus of the epidemic area clinical front-line actual needs, “the key epidemic areas in the extraordinary period to take extraordinary measures, as a last resort.” In this case, it is difficult to contain the outbreak if we do not concentrate on tightening your fists. “

On February 5th, Wang Chen, a respiratory and critically ill medical expert, vice president of the Chinese Academy of Engineering and president of the Chinese Academy of Medical Sciences, said in a guest appearance in the “News 1 and 1” section, “Not all people with the disease can test positive for nucleic acids, and the rate of nucleic acid stoiding on real cases is only 30% to 50%.” “

“Where have the remaining 50 per cent gone?” If left out, he returns to his family and community, leaving outside society to cause potential infections. Zhang said.

Zhang Xiaochun pointed out that the CT test results are intuitive, fast, the public’s access to high, “so I suggest edgto not waiting for nucleic acid test results, while checking the lung CT image to check this two-legged walking method.” But do not wait is not equal to do not do, this is CT can not replace nucleic acid pathogen testing, can only be used as an objective means of response to inflammation of the lungs. “

Since CT imaging does not tell whether it is another pneumonia or new coronary pneumonia, will it lead to the wrong treatment if patients who do not receive kit test results are treated together?

In this regard, Zhang Xiaochun believes that as long as it is the new pneumonia, whether it is new coronapneumonia, or other viruses, bacterial infections or other microorganisms caused by pneumonia, the current treatment method is generally the same. New coronary pneumonia has no special drugs, nothing but antiviral, anti-bacterial, antifungal, support ingestion, oxygen saturation is insufficient oxygen absorption and so on. Since the treatment is the same, CT has a lung-positive imaging performance should be treated first, so at least not to miss.

However, Zhang also stressed that after the treatment of such patients, to do single-room isolation treatment, in order to reduce the probability of cross-infection, “if there is no conditions, create conditions to go on.” “

For areas outside Hubei Province, Zhang said the move is not suitable for provinces that only distribute cases.

To Zhang’s relief, the value of video diagnosis has been recently updated in the fifth edition of the “new coronary virus infection pneumonia diagnosis and treatment program” has been reflected. The program mentioned that “suspected cases with pneumonia imaging characteristics” as the clinical diagnosis of the case standard in Hubei Province, which suggests that the clinical diagnosis of the new coronavirus in Hubei Province no longer waits for nucleic acid test results, this standard is conducive to early and timely treatment of pneumonia patients in Hubei Province.

At the same time, Wuhan overnight to build three “square cabin hospital”, a total of 3,400 beds will be provided for the treatment of new coronavirus infection of patients with pneumonia. In addition to Hubei, the means of prevention and control are also upgrading, the degree of severity is unprecedented.

Zhang pointed out that the current epidemic prevention pressure in Wuhan and Hubei is still huge. The CT imaging as the basis of clinical diagnosis will also face great challenges, not only to test the resource reserves in Hubei Province, but also to put forward higher requirements for the professional ism of medical personnel, but also to cross-infection control put forward new requirements.

“There are two major challenges in putting CT into practice as one of the new pneumonia screening standards, the first is that there will be a large number of suspected patients into the hospital, in many places the number of CT machines, technical staff is insufficient, the load is still greatly challenged. This requires the unified deployment and support of the country. Zhang said. The second challenge is to prevent and control cross-infection in the hospital. “Not only cross-infection between patients, but also the occupational exposure of doctors, we need to do a good job of one person, one machine, one disinfection, patient doctors at the same time disinfection, protection materials are already insufficient, in this case the implementation of the difficulty is also relatively large. Wuhan in Hubei Province is the focus of the key epidemic areas, and more efforts need to be concentrated to solve them. A few days ago, Zhang Xiaochun also put forward the proposal of moving CT or square cabin CT into Wuhan to meet the needs of the lung CT examination of the square cabin hospital and isolation point.