The Indian Radiological and Imaging Association is shocked and disappointed at the recent comments by Dr Randeep Guleria, Director AIIMS on the use of CT Scans in the evaluation of Covid 19 patients, which has been widely circulated by the press and social media. The statement given by Dr Randeep are misleading and creates confusion among the public and his warning that one CT scan is equal to 300-400 X Rays and CT scans cause cancer is outdated and wrong.

We would like to put out a few facts to clear the confusion.

1. RT PCR is the investigation of choice for diagnosing COVID 19 patients. However CT Scan is used in diagnosis in patients who have typical features of Covid 19 but are RTPCR negative due to mutant variant, technical errors or low viral load. CT Chest helps to diagnose these patients and early detection helps to start treatment and also stops them from being super spreaders. It is for this reason several state governments have asked the radiology departments to notify patients with CORADS score of 4 or 5.

2. While RTPCR helps in the diagnosis, CT Chest helps to stage the severity of disease, especially in symptomatic patients. CT Score given for COVID 19 patients helps the clinicians initiate treatment. This score helps the clinicians decide if the patient can be in home quarantine or needs hospital admission.

3. CT Chest is helpful to stage the disease mild, moderate or severe , there by contributing significantly in management. More over the progression of the disease can be monitored by CT especially in patients who are deteriorating.

In a disease like Covid 19 which has a very unpredictable course Identifying at risk individuals early and timely initiation of treatment is of utmost importance. As CT is far more sensitive than saturation monitoring by pulse oximetry in detecting lung damage, in the early phase of disease

Initiating steroids at the right time can halt the progression of lung involvement before saturation starts falling. Already hospitals are overburdened and with early administration of treatment, it might be possible to manage the patients at home . Earlier the treatment is started, easier it is to save a patient.

Now young people present with happy hypoxia (when patients have low oxygen saturation, but do not feel any symptoms) and they do not get alarmed till the disease has progressed with severe damage to lungs. This is common with young patients who can with stand upto Spo2 of 80 % , while older people can withstand upto 90% Spo2.

4. CT Chest can be performed quickly especially in emergencies when RTPCR reports take time, and initiation of early treatment is a requirement. CT Chest helps to alert the clinician of a suspicious patient, thus preventing the exposure of healthcare professionals and also preventing a super spreader scenario.

5. CT Chest also helps to diagnose several conditions that mimic Covid 19 like other bacterial and viral infections, cardiac failure etc…

6. CT Chest vs Chest X ray

The classical feature of Covid 19 is the ground glass opacities seen in the subpleural region especially in the lower lobes. Several studies have concluded that Chest X ray is useless in the diagnosis of early Covid and can be used only in the follow of patients with severe Covid 19 pneumonia to monitor progression. The study shows that CT scanning has demonstrated excellent sensitivity and should strongly be considered during the pandemic in the initial assessment of COVID-19. This needs to be balanced against the risk of excess radiation with CT, where capacity allows.

7. Radiation in CT Imaging

Dr Randeep in his statement had claimed that one CT Chest is equal to 300-400 X rays. This is a very retrograde and was the situation 30-40 years ago. The modern CT Scanners use ultra low dose CT which has radiation comparable to only 5 – 10 x-rays. Radiologists all over the world follow the ALARA principle (As Low As Reasonably Achievable) and give the minimal radiation possible during the scan. With the advent of low dose CT techniques and advancement in the software’, the dose is reduced to one third to one fourth and with ultra low dose CT scan, we can reduce to one tenth. The medical investigations and treatment are also analysed based on the Risk vs Benefit Ratio and is very clear in this case the Benefit far outweighs the Risk which is almost non-existent.

Also the statement that CT Chest can cause Lung Cancer is alarming. The radiation dose from a single CT Chest is almost equivalent to the back ground radiation received by any person over a year. At a time when the Covid 19 pandemic is creating havoc and we are trying to triage the patients and make use of the limited medical supplies to the best, such type of unscientific and irresponsible statements from such senior health authorities creates confusion among the public and hampers COVID 19 treatment.

During this ragging Covid 19 pandamic, Radiologists and radiographers are putting their life at risk and are contributing significantly in this battle. IRIA is promoting the vaccination drive of the nation and also all precautions suggestions by the Government of India. I also salute all the radiation workers who are working with the risk of COVID 19 and radiation.

Long Live IRIA !

Jai Hind !!

Prof. C. Amarnath Dr. Sandeep Kavthale

President, IRIA Secretary General, IRIA


1. European Respiratory Journal 2021; DOI: 10.1183/13993003.04188-2020

2. Borakati A, Perera A, Johnson J, et al

3. Diagnostic accuracy of X-ray versus CT in COVID-19: a propensity-matched database study

4. BMJ Open 2020;10:e042946. doi: 10.1136/bmjopen-2020-042946

5. Was non‐utilisation of computed tomography as a public health tool a costly lapse in closing the pandemic? – Editorial IJRI. Dr Anirudh Kholi Chief Radiologist Breach Candy Hospital Trust, 60 Bhulabhai Desai Road, Mumbai, Maharashtra, India. E‐mail:, IJRI

6. Incidental chest computed tomography findings in asymptomatic Covid‐19 patients. A multicentre Indian perspective Rochita V Ramanan, Anagha R Joshi1, Akash Venkataramanan2, Senthur P Nambi3, Rashmi Badhe, Departments of Radiology and 3Infectious Diseases, Apollo Hospitals Chennai, 2Intern, Madras Medical College, Chennai, Tamil Nadu, 1Department of Radiology, Lokmanya Tilak Municipal Medical College and General Hospital, Sion, 4Department of Radiology, Global Hospitals, Mumbai, Maharashtra, India , IJRI

7. Does CT help in reducing RT‐PCR false negative rate for COVID‐19? Anirudh Kohli, Anagha Joshi1, Ankur Shah2, Richa D Jain3, Abhishek Gorlawar4, Amol Dhapare5, Jigar Desai6, Aditya Shetty, Chirag Shah7, Prachi Ostwal8, Anisha Talraja1 Department of Radiodiagnosis, Breach Candy Hospital, Mumbai, 1Department of Radiodiagnosis, LTMMC Sion Hospital, Mumbai , 2Sadbhav Diagnostics, Ahmedabad, 3Department Of Radiodiagnosis, Aster CMI Hospital, Bengaluru, 4Ravi Imaging and Jupiter Hospital, Mumbai, 5Nivaran and Pulse Scan Centre, Mumbai, 6NM Medical Centre, Mumbai, 7Advance RadioImaging Centre, Ahmedabad, Pinnacle Imaging Centre, Mumbai, India

8. Coronavirus Disease 2019 (COVID-19): Role of Chest CT in Diagnosis and Management. Yan Li1 and Liming Xia1

Read More:

9. The accuracy of chest CT in the diagnosis of COVID-19: An umbrella review. Jae Young Park, Rosemary Freer, Richard Stevens, Neil Soneji, Nicholas Jone

10. Chest CT in COVID-19: What the Radiologist Needs to Know

11. Thomas C. Kwee , Robert M. Kwee, Oct 23 2020

12. Lung Cancer Screening CT Protocols Version 5.0, 24 July 2019



15. Effective dose equivalent ranges from 0.06 to 0.25 millisieverts (mSv) with chest radiography (conventional) in 2 views, 3-27 mSv with computed tomography (CT) using conventional examination parameters, and 0.3-0.55 mSv using low dose CT settings.





The average effective dose of the chest posteroanterior examination (digital) was found to be 0.04 mSv, which was 1.3% that of the chest CT examination.


This means that if 1 million persons are exposed to 0.1 mSv of radiation, five would develop a fatal cancer.

Indian Radiological & Imaging Association

IRIA House, C-5, Qutab Institutional Area

Behind Qutab Hotel

New Delhi-110 016


Tel. +91-11-26965598, +91-11-41688846. Fax: +91-11-26565391



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