Agreement between low-dose and ultra-low-dose chest CT for the diagnosis of viral pneumonia imaging patterns during the COVID-19 pandemic

Abstract Background Chest CT scan has an important role in the diagnosis and management of COVID-19 infection. A major concern in radiologic assessment of the patients is the radiation dose. Research has been done to evaluate low-dose chest CT in the diagnosis of pulmonary lesions with promising findings. We decided to determine diagnostic performance of ultra-low-dose chest CT in comparison to low-dose CT for viral pneumonia during the COVID-19 pandemic. Results 167 patients underwent both low-dose and ultra-low-dose chest CT scans. Two radiologists blinded to the diagnosis independently examined ultra-low-dose chest CT scans for findings consistent with COVID-19 pneumonia. In case of any disagreement, a third senior radiologist made the final diagnosis. Agreement between two CT protocols regarding ground-glass opacity, consolidation, reticulation, and nodular infiltration were recorded. On low-dose chest CT, 44 patients had findings consistent with COVID-19 infection. Ultra-low-dose chest CT had sensitivity and specificity values of 100% and 98.4%, respectively for diagnosis of viral pneumonia. Two patients were falsely categorized to have pneumonia on ultra-low-dose CT scan. Positive predictive value and negative predictive value of ultra-low-dose CT scan were respectively 95.7% and 100%. There was good agreement between low-dose and ultra-low-dose methods (kappa = 0.97; P < 0.001). Perfect agreement between low-dose and ultra-low-dose scans was found regarding diagnosis of ground-glass opacity (kappa = 0.83, P < 0.001), consolidation (kappa = 0.88, P < 0.001), reticulation (kappa = 0.82, P < 0.001), and nodular infiltration (kappa = 0.87, P < 0.001). Conclusion Ultra-low-dose chest CT scan is comparable to low-dose chest CT for detection of lung infiltration during the COVID-19 outbreak while maintaining less radiation dose. It can also be used instead of low-dose chest CT scan for patient triage in circumstances where rapid-abundant PCR tests are not available.

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Use of Low-dose Chest CT Scan in the Evaluation of Breast Composition According to the Recommendations of BI-RADS Atlas-Fifth Edition

Iranian Journal of Radiology ◽

10.5812/iranjradiol.96718 ◽

2020 ◽

Vol 17 (2) ◽

Author(s):

Feng Ao ◽

Xueguo Liu ◽

Mingzhu Liang ◽

Jiebing Gao

Keyword(s):

Lung Cancer ◽

Ct Scan ◽

Low Dose ◽

Chest Ct ◽

Dense Breast ◽

Ct Scans ◽

Low Dose Ct ◽

Dense Breasts ◽

Breast Tissues ◽

Chest Ct Scan

Background: Breast cancer and lung cancer are the leading causes of cancer-related mortality in women. Computed tomography (CT) plays an important role in lung cancer examination but an unidentified role in breast examination. Objectives: To investigate the feasibility of breast composition categorization according to the fifth edition of Breast Imaging-Reporting and Data System (BI-RADS) atlas in low-dose CT screening. Patients and Methods: This was a cross-sectional study completed in The 5th Affiliated Hospital of Sun Yat-sen University, Zhuhai, China. We collected the imaging data of 57 women, who underwent low-dose chest CT scan and mammography within one week from 1st October 2013 to 31st March 2015. Two radiologists independently interpreted the mammograms and chest CT scans and classified the breast composition into categories a, b, c, and d. We also summarized the distribution of breast composition categories by collecting, observing, and classifying the chest CT scans from 1916 female examinees from 1st October 2013 to 31st March 2016. Results: Excellent agreement was observed between the two radiologists, using both low-dose CT scan (κ = 0.91) and mammography (κ = 0.86). Agreement between low-dose chest CT scan and mammography was moderate for radiologist A (κ = 0.50) and radiologist B (κ = 0.43). More breasts were classified in categories a and b on the chest CT scan compared to mammography according to both radiologist A (P < 0.01) and radiologist B (P < 0.01). The proportion of non-dense breast tissues (categories a & b) increased with advancing age, while the proportion of dense breast tissues (categories c & d) decreased (P < 0.05). With advancing age, the probability of non-dense breasts increased, while the probability of dense breasts decreased. Conclusions: Based on the findings, it is feasible to categorize breast composition using low-dose chest CT. In the older age group, the probability of non-dense breasts increased.

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A review on chest CT scanning parameters implemented in COVID-19 patients: bringing low-dose CT protocols into play

Egyptian Journal of Radiology and Nuclear Medicine ◽

10.1186/s43055-020-00400-1 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

Javid Azadbakht ◽

Daryoush Khoramian ◽

Zahra Sadat Lajevardi ◽

Fateme Elikaii ◽

Amir Hossein Aflatoonian ◽

...

Keyword(s):

Radiation Dose ◽

Ct Scan ◽

Low Dose ◽

Standard Dose ◽

Ct Scanning ◽

Chest Ct ◽

Main Body ◽

Low Dose Ct ◽

Ct Protocol ◽

Chest Ct Scan

Abstract Background This study aims to review chest computed tomography (CT) scanning parameters which are utilized to evaluate patients for COVID-19-induced pneumonia. Also, some of radiation dose reduction techniques in CT would be mentioned, because using these techniques or low-dose protocol can decrease the radiation burden on the population. Main body Chest CT scan can play a key diagnostic role in COVID-19 patients. Additionally, it can be useful to monitor imaging changes during treatment. However, CT scan overuse during the COVID-19 pandemic raises concerns about radiation-induced adverse effects, both in patients and healthcare workers. Conclusion By evaluating the CT scanning parameters used in several studies, one can find the necessity for optimizing these parameters. It has been found that chest CT scan taken using low-dose CT protocol is a reliable diagnostic tool to detect COVID-19 pneumonia in daily practice. Moreover, the low-dose chest CT protocol results in a remarkable reduction (up to 89%) in the radiation dose compared to the standard-dose protocol, not lowering diagnostic accuracy of COVID-19-induced pneumonia in CT images. Therefore, its employment in the era of the COVID-19 pandemic is highly recommended.

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Benefits of Low-Dose CT Scan of Head for Patients With Intracranial Hemorrhage

Dose-Response ◽

10.1177/1559325820909778 ◽

2020 ◽

Vol 19 (1) ◽

pp. 155932582090977

Author(s):

Dan Wu ◽

Gang Wang ◽

Bingyang Bian ◽

Zhuohang Liu ◽

Dan Li

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Ct Scan ◽

Low Dose ◽

Ct Scans ◽

Current Time ◽

Low Dose Ct ◽

Tube Current ◽

Conventional Ct ◽

Tube Current Time Product

Objectives: For patients with intracranial hemorrhage (ICH), routine follow-up computed tomography (CT) scans are typically required to monitor the progression of intracranial pathology. Remarkable levels of radiation exposure are accumulated during repeated CT scan. However, the effects and associated risks have still remained elusive. This study presented an effective approach to quantify organ-specific radiation dose of repeated CT scans of head for patients with ICH. We also indicated whether a low-dose CT scan may reduce radiation exposure and keep the image quality highly acceptable for diagnosis. Methods: Herein, 72 patients with a history of ICH were recruited. The patients were divided into 4 groups and underwent CT scan of head with different tube current–time products (250, 200, 150, and 100 mAs). Two experienced radiologists visually rated scores of quality of images according to objective image noise, sharpness, diagnostic acceptability, and artifacts due to physiological noise on the same workstation. Organ-/tissue-specific radiation doses were analyzed using Radimetrics. Results: In conventional CT scan group, signal to noise ratio (SNR) and contrast to noise ratio (CNR) of ICH images were significantly higher than those in normal brain structures. Reducing the tube current–time product may decrease the image quality. However, the predilection sites for ICH could be clearly identified. The SNR and CNR in the predilection sites for ICH were notably higher than other areas. The brain, eye lenses, and salivary glands received the highest radiation dose. Reducing tube current–time product from 250 to 100 mA can significantly reduce the radiation dose. Discussion: We demonstrated that low-dose CT scan of head can still provide reasonable images for diagnosing ICH. The radiation dose can be reduced to ∼45% of the conventional CT scan group.

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A meta-analysis of accuracy and sensitivity of chest CT and RT-PCR in COVID-19 diagnosis

Scientific Reports ◽

10.1038/s41598-020-80061-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Fatemeh Khatami ◽

Mohammad Saatchi ◽

Seyed Saeed Tamehri Zadeh ◽

Zahra Sadat Aghamir ◽

Alireza Namazi Shabestari ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Reverse Transcriptase ◽

Ct Scan ◽

Predictive Value ◽

Meta Analysis ◽

Chest Ct ◽

Rt Pcr ◽

Chain Reaction ◽

Polymerase Chain ◽

Chest Ct Scan

AbstractNowadays there is an ongoing acute respiratory outbreak caused by the novel highly contagious coronavirus (COVID-19). The diagnostic protocol is based on quantitative reverse-transcription polymerase chain reaction (RT-PCR) and chests CT scan, with uncertain accuracy. This meta-analysis study determines the diagnostic value of an initial chest CT scan in patients with COVID-19 infection in comparison with RT-PCR. Three main databases; PubMed (MEDLINE), Scopus, and EMBASE were systematically searched for all published literature from January 1st, 2019, to the 21st May 2020 with the keywords "COVID19 virus", "2019 novel coronavirus", "Wuhan coronavirus", "2019-nCoV", "X-Ray Computed Tomography", "Polymerase Chain Reaction", "Reverse Transcriptase PCR", and "PCR Reverse Transcriptase". All relevant case-series, cross-sectional, and cohort studies were selected. Data extraction and analysis were performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5. Among 1022 articles, 60 studies were eligible for totalizing 5744 patients. The overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan compared to RT-PCR were 87% (95% CI 85–90%), 46% (95% CI 29–63%), 69% (95% CI 56–72%), and 89% (95% CI 82–96%), respectively. It is important to rely on the repeated RT-PCR three times to give 99% accuracy, especially in negative samples. Regarding the overall diagnostic sensitivity of 87% for chest CT, the RT-PCR testing is essential and should be repeated to escape misdiagnosis.

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The role of CT imaging for management of COVID-19 in epidemic area: early experience from a University Hospital

Insights into Imaging ◽

10.1186/s13244-020-00957-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Vikram rao Bollineni ◽

Koenraad Hans Nieboer ◽

Seema Döring ◽

Nico Buls ◽

Johan de Mey

Keyword(s):

Ct Scan ◽

Predictive Value ◽

Ct Imaging ◽

Chest Ct ◽

University Hospital ◽

Rt Pcr ◽

Ct Findings ◽

Epidemic Area ◽

Chest Ct Scan ◽

Pcr Test

Abstract Background To evaluate the clinical value of the chest CT scan compared to the reference standard real-time polymerase chain reaction (RT-PCR) in COVID-19 patients. Methods From March 29th to April 15th of 2020, a total of 240 patients with respiratory distress underwent both a low-dose chest CT scan and RT-PCR tests. The performance of chest CT in diagnosing COVID-19 was assessed with reference to the RT-PCR result. Two board-certified radiologists (mean 24 years of experience chest CT), blinded for the RT-PCR result, reviewed all scans and decided positive or negative chest CT findings by consensus. Results Out of 240 patients, 60% (144/240) had positive RT-PCR results and 89% (213/240) had a positive chest CT scans. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of chest CT in suggesting COVID-19 were 100% (95% CI: 97–100%, 144/240), 28% (95% CI: 19–38%, 27/240), 68% (95% CI: 65–70%) and 100%, respectively. The diagnostic accuracy of the chest CT suggesting COVID-19 was 71% (95% CI: 65–77%). Thirty-three patients with positive chest CT scan and negative RT-PCR test at baseline underwent repeat RT-PCR assay. In this subgroup, 21.2% (7/33) cases became RT-PCR positive. Conclusion Chest CT imaging has high sensitivity and high NPV for diagnosing COVID-19 and can be considered as an alternative primary screening tool for COVID-19 in epidemic areas. In addition, a negative RT-PCR test, but positive CT findings can still be suggestive of COVID-19 infection.

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PULMONARY BIRT-HOGG-DUBE SYNDROME: A GOOD REASON TO ROUTINELY PERFORM A LOW DOSE CHEST CT SCAN IN PATIENTS WITH PRIMARY SPONTANEOUS PNEUMOTHORAX?

CHEST Journal ◽

10.1016/j.chest.2018.08.520 ◽

2018 ◽

Vol 154 (4) ◽

pp. 576A

Author(s):

JINCEY SRIRAM ◽

IRMA VAN DE BEEK ◽

PAUL JOHANNESMA ◽

MICHIEL VAN WERKUM ◽

TIJMEN VAN DER WEL ◽

...

Keyword(s):

Ct Scan ◽

Spontaneous Pneumothorax ◽

Low Dose ◽

Good Reason ◽

Chest Ct ◽

Primary Spontaneous Pneumothorax ◽

Chest Ct Scan

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Lung Ultrasound Findings Compared to Chest CT Scan in Patients with COVID-19 Associated Pneumonia: A Pilot Study

Frontiers in Emergency Medicine ◽

10.18502/fem.v5i2.5612 ◽

2021 ◽

Author(s):

Hamidreza Hatamabadi ◽

Majid Shojaee ◽

Mohammad Bagheri ◽

Masoomeh Raoufi

Keyword(s):

Pilot Study ◽

Ct Scan ◽

Sensitivity And Specificity ◽

Lung Ultrasound ◽

Demographic Data ◽

Ground Glass Opacity ◽

Chest Ct ◽

Clinical Value ◽

Ultrasound Evaluation ◽

Chest Ct Scan

Introduction: Lung US has been reported to be as useful as a chest CT scan and much better than a chest x-ray for the evaluation of pneumonia. Objective: This study aimed to compare the findings of lung ultrasound (US) and chest CT scan of patients with COVID-19-associated pneumonia in the Emergency Department (ED). Methods: This retrospective observational pilot study was carried out on confirmed COVID-19 patients in the isolation corona ward of the Imam Hussein Hospital ED from March 15 to March 22, 2020. After obtaining demographic data, the patients underwent a pulmonary bedside US examination, with the patients in the sitting position, turning their back to the examiner. A 10-point lung US was performed. Each lung was divided into two areas: posterior (three zones) and lateral (two zones). The patients’ lung ultrasound and chest CT scan as the standard imaging were blindly reviewed and recorded. The clinical value of ultrasound was evaluated with different severity of lung involvement according to CT severity score. Results: Nineteen patients (38 zones), including 13 males, were evaluated with a mean age of 62.5±16.8 years. B2 lines and consolidation observed in the US examinations were significantly correlated with ground-glass opacity and consolidation observed in CT scan examinations, respectively (p <0.0001). US sensitivity and specificity of finding B2 lines were 90% and 100%, respectively. Also, the sensitivity and specificity of US in identifying consolidation were 82% and 100%, respectively. In the lungs with moderate and severe lobar involvement, US findings were significantly correlated (p <0.05) with CT scan findings. Conclusions: Ultrasound evaluation is a safe, fast, and rapid technique for the evaluation of patients with moderate to severe COVID-19-associated pneumonia. It is a reproducible procedure and can be implemented by the operator after a short course of training.

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Ultrasound Detection of Pneumothorax Compared with Chest X-Ray and Computed Tomography Scan

The American Surgeon ◽

10.1177/000313481107700427 ◽

2011 ◽

Vol 77 (4) ◽

pp. 480-483 ◽

Cited By ~ 29

Author(s):

Khanjan Nagarsheth ◽

Stanley Kurek

Keyword(s):

Ct Scan ◽

Negative Predictive Value ◽

Predictive Value ◽

Chest Ct ◽

Trauma Patients ◽

X Rays ◽

Thoracic Ultrasound ◽

X Ray ◽

Chest X Ray ◽

Chest Ct Scan

Pneumothorax after trauma can be a life threatening injury and its care requires expeditious and accurate diagnosis and possible intervention. We performed a prospective, single blinded study with convenience sampling at a Level I trauma center comparing thoracic ultrasound with chest X-ray and CT scan in the detection of traumatic pneumothorax. Trauma patients that received a thoracic ultrasound, chest X-ray, and chest CT scan were included in the study. The chest X-rays were read by a radiologist who was blinded to the thoracic ultrasound results. Then both were compared with CT scan results. One hundred and twenty-five patients had a thoracic ultrasound performed in the 24-month period. Forty-six patients were excluded from the study due to lack of either a chest X-ray or chest CT scan. Of the remaining 79 patients there were 22 positive pneumothorax found by CT and of those 18 (82%) were found on ultrasound and 7 (32%) were found on chest X-ray. The sensitivity of thoracic ultrasound was found to be 81.8 per cent and the specificity was found to be 100 per cent. The sensitivity of chest X-ray was found to be 31.8 per cent and again the specificity was found to be 100 per cent. The negative predictive value of thoracic ultrasound for pneumothorax was 0.934 and the negative predictive value for chest X-ray for pneumothorax was found to be 0.792. We advocate the use of chest ultrasound for detection of pneumothorax in trauma patients.

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Chest CT Imaging Characteristics of COVID-19 Pneumonia in Surviving and Non-Surviving Hospitalized Patients: A Retrospective Study in a Referral Center in Tehran, Iran

Iranian Journal of Radiology ◽

10.5812/iranjradiol.106339 ◽

2021 ◽

Vol 18 (2) ◽

Author(s):

Sara Besharat ◽

Fatemehsadat Rahimi ◽

Siamak Afaghi ◽

Farzad Esmaeili Tarki ◽

Fatemeh Pourmotahari ◽

...

Keyword(s):

Pleural Effusion ◽

Ct Scan ◽

Chest Ct ◽

Ct Scans ◽

Early Management ◽

Ct Findings ◽

Imaging Characteristics ◽

Significant Difference ◽

Chest Ct Scan ◽

Lung Lobes

Background: Coronavirus disease 2019 (COVID-19) has several chest computed tomography (CT) characteristics, which are important for the early management of this disease, because viral detection via RT-PCR can be time-consuming, resulting in a delayed pneumonia diagnosis. The Radiological Society of North America (RSNA) proposed a reporting language for CT findings related to COVID-19 and defined four CT categories: typical, indeterminate, atypical, and negative. Objectives: To retrospectively evaluate the chest CT characteristics of patients with COVID-19 pneumonia. Patients and Methods: A total of 115 hospitalized laboratory-verified COVID-19 cases, underdoing chest CT scan, were included in this study from April 30 to May 15, 2020. Of 115 cases, 53 were discharged from the hospital, and 62 expired. The initial clinical features and chest CT scans were assessed for the type, pattern, distribution, and frequency of lesions. Moreover, the findings were compared between ward-hospitalized, ICU-admitted, and non-surviving (expired) patients. Results: Of four CT categories, typical CT findings for COVID-19 were more frequent in the expired group (77.4%), compared to the ward-admitted (44.8%) and ICU-admitted (70.8%) groups (P = 0.017). However, no significant difference was observed in the prevalence of intermediate or atypical CT findings between the groups. Negative CT scans for the diagnosis of COVID-19 were significantly fewer in the expired group (0%) as compared to the ward-admitted (10.3%) and ICU-admitted (8.3%) groups (P = 0.0180). Also, the mean number of involved lung lobes and segments was significantly higher in the expired group compared to the other two groups (P = 0.032 and 0.010, respectively). The right upper lobe involvement, right middle lobe involvement, bilateral involvement, central lesion, air bronchogram, and pleural effusion were among CT scan findings with a significantly higher prevalence in non-surviving cases (P < 0.0001, 0.047, 0.01, 0.036, 0.038, and 0.047, respectively). Conclusion: The increased number of involved lung lobes and segments, bilateral and central distribution patterns, air bronchogram, and severe pleural effusion in the initial chest CT scan can be related to the increased severity and poor prognosis of COVID-19.

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The exact place of PCR and chest CT in screening, staging, and diagnosis of Covid-19: A meta-analysis

10.21203/rs.3.rs-32961/v1 ◽

2020 ◽

Author(s):

Fatemeh Khatami ◽

Mohammad Saatchi ◽

Seyed Saeed Tamehri Zadeh ◽

Zahra Sadat Aghamir ◽

Alireza Namazi Shabestari ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Reverse Transcriptase ◽

Ct Scan ◽

Predictive Value ◽

Meta Analysis ◽

Chest Ct ◽

Rt Pcr ◽

Chain Reaction ◽

Polymerase Chain ◽

Chest Ct Scan

Abstract Introduction: Nowadays there is an ongoing acute respiratory outbreak causing by the novel highly contagious coronavirus (nCoV). There are two diagnostic protocol based on chest CT scan and quantitative reverse-transcription polymerase chain reaction (RT-PCR) which their diagnostic accuracy is under the debate. We designed this meta-analysis study to determine the diagnostic value of initial chest CT scan in patients with nCoV infection in comparison with RT- PCR.Search strategy and statistical analysis: Three main databases the PubMed (MEDLINE), Scopus, and EMBASE was systematically searched for all published literatures from January 1st, 2019, to the 27th march 2020 with key grouping of “COVID19 virus”, “2019 novel coronavirus”, “Wuhan coronavirus”, “2019-nCoV”, “X-Ray Computed Tomography”, “Polymerase Chain Reaction”, “Reverse Transcriptase PCR”, and “PCR Reverse Transcriptase”. All relevant case- series, cross-sectional, and cohort studies were selected. Data extraction was done in Excel 2007 (Microsoft Corporation, Redmond, CA) and their analysis was performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5.Result: From first recruited 668 articles we end up to the final 47 studies, which comprised a total sample size of 4238 patients. In compare to RT-PCR, the overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan were 86% (95% CI: 83% -90%), 43 % (95% CI: 26% -60%), 67% (95% CI: 57% -78%), and 84% (95% CI: 74% -95%) respectively. However the RT-PCR should be repeated for three times in order to give the 99% accuracy especially in negative samples.Conclusion: According to the acceptable sensitivity of chest CT scan, it can be employed complement to RT-PCR to diagnosis patients who are clinically suspicious for nCoV.

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