Typical Computed Tomography Findings Research Articles

Treacher Collins Syndrome (mandibulofacial dysostosis) – A case report

Background. Treacher-Collins Syndrome (TCS) (or mandibulofacial dysostosis) is a rare autosomal dominant genetic disorder involving 1st and 2nd branchial arches present with craniofacial deformities with variable expressivity. TCS commonly manifests as facial dysmorphism with varied presentations. In this case report, we demonstrate the typical CT (Computed Tomography) findings of the characteristic features. Case report. Here, we report an 8-year-old boy who presented for evaluation of uneven facial features. Upon a multidisciplinary evaluation, he was diagnosed with TCS, and the characteristic radiological features are described in this report. Conclusions. TCS has a variable degree of phenotypic expression with no related developmental delay or neurologic disorder. Proper counselling, planning, and surgical procedures are necessary for more promising results.

Radiologic Manifestations of Mycobacterium chimaera Infection After Open Heart Surgery.

The objective of this study is to identify and detail the radiologic manifestations of surgical site and disseminated Mycobacterium chimaera ( MC) infection. The aim is to facilitate early identification and diagnosis of MC, considering its indolent nature and the challenges involved in clinically and pathologically establishing the diagnosis. This was a retrospective cohort study reviewing computed tomography (CT), positron emission tomography (PET)/CT, and magnetic resonance imaging examinations in patients over the age of 18 years with a history of open heart surgery and a clinical or pathologic diagnosis of MC. Two radiology residents, a fellowship-trained nuclear medicine radiologist, and a fellowship-trained cardiothoracic radiologist performed consensus reads to determine the imaging findings seen in MC infection. Twenty-five patients were included. Localized, surgical site infection was more common than disseminated disease. Typical CT findings included peristernal soft tissue thickening, sinus tracts often extending to the cutaneous surface, slowly enlarging fluid collections, and sternal osteolysis. PET/CT findings demonstrated hypermetabolic activity in nearly all patients localized to sites of infection. Imaging findings for disseminated infection included hepatosplenomegaly, lymphadenopathy, involvement of the central nervous system, discitis/osteomyelitis, and distant abscesses. Imaging plays a vital role in suggesting possible surgical sites and disseminated MC infection acquired from open heart surgery. Radiologists must keep a high index of suspicion given the indolent nature and subtle imaging change over time. PET/CT is most useful in diagnosis and helps in differentiating between a sterile postoperative fluid collection or scarring and active MC infection and helps provide a target for debridement.

A maintenance hemodialysis patient complicated with hypogammaglobulinemia presenting typical COVID-19 pneumonia CT findings: a case report

BackgroundWith the widespread use of the vaccine and the predominance of the Omicron strain, the number of patients presenting with typical coronavirus-infection disease 2019 (COVID-19) pneumonia on computed tomography (CT) has decreased dramatically. This has also been true for hemodialysis patients.Case reportA 72-year-old female maintenance hemodialysis patient with hypogammaglobulinemia was diagnosed with COVID-19 based on a nasopharyngeal swab severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) polymerase chain reaction (PCR) test. She had previously received five doses of COVID-19 BNT162b2 vaccine. Initially, the patient had only a slight fever, mild sore throat and sputum, and molnupiravir 1600 mg/day was administered for 5 days. No high fever was observed during that period. On day 11 after diagnosis, bloody sputum was observed, and by day 13 the cough had worsened and her CRP level had increased to 13.10 mg/dL. Chest CT performed on the same day showed multiple subpleural ground-glass-like shadows typical of COVID-19 pneumonia predominantly in the right lung. She was immediately admitted to the hospital, where her temperature rose to 38.4 °C. Intravenous remdesivir 100 mg/day was administered for 5 days. This resolved her fever and the bloody sputum disappeared. She was discharged from the hospital without sequelae on the 21st day after diagnosis.ConclusionWe experienced a case of typical COVID-19 pneumonia in a patient on maintenance hemodialysis who had received five doses of COVID-19 BNT162b2 vaccine. There was a flare-up of symptoms after administration of molnupiravir, suggesting that a hypogammaglobulinemia complication was involved. This highlights the need for attention to its potential transition to severe disease when patients with hypogammaglobulinemia or other highly immunocompromised conditions are affected by COVID-19.

Frequency of atypical pulmonary manifestations of COVID-19 patients on chest CT-scan: a cross-sectional study

BackgroundChest CT is a crucial diagnostic tool in COVID-19 due to its high sensitivity. Typical chest CT findings such as reversed halo sign, vascular enlargement, and air-bronchogram are commonly recognized in the pandemic, but finding atypical signs is essential to diagnose. We aimed to investigate the prevalence of the atypical manifestations during the two months of 2022 and compare the results to studies conducted before its outbreak.MethodsThose patients with positive, positive RT-PCR tests were reevaluated to see if they met the inclusion and exclusion. Demographic information of patients, including age and sex, was recorded. The computed tomography (CT) examination was carried out using a 100-slice scanner (Philips Brilliance 6 CT Scanner). Two radiology specialists evaluated SARS-CoV-2 RT-PCR-positive patients for atypical pulmonary CT findings separately. The obtained data were evaluated using R software version 4.1.1.Results606 confirmed COVID-19 cases were included in this study based on inclusion and exclusion criteria during January and February 2022. 55% of patients were female, and the median age was 56 (IQR: 42, 69). More than half of the patients (59%) had atypical findings on their pulmonary CT examination. These findings showed that pleural abnormalities were the most frequent atypical finding. Among pleural abnormalities, pleural thickening was the most common (17%). The double halo sign represented the least frequent atypical sign (0.2%).ConclusionsAtypical findings were more prevalent in this study than its predecessors, while we acknowledge that other factors, such as study design and patient population, could have impacted it. The presence of atypical signs generally was not correlated with specific demographic groups, while some of these signs were more frequent in particular groups.

Distribution of Chest Computed Tomography Findings in 202 Saudi Patients with COVID-19

Background: Computed tomography (CT) is one radiographic imaging modality that plays an essential role in detecting, characterizing, and assessing the complications of COVID-19. The aim of this study was to determine the distribution of chest CT findings (typical and associated) in 202 Saudi patients with COVID-19. Methods and Results: Medical records of 202 patients diagnosed in Ohod and Al-Madinah National Hospitals (Al-Madinah Al-Monwarahwith) with positive COVID-19 infection from February 1 to March 1, 2021, were analyzed in this retrospective study. A verbal ethical agreement was obtained from the radiology department in these hospitals. Patients' demographic data and chest CT findings were evaluated. The majority of the sample was male 128(63.4%), and the largest age group was 50–64 years (41.1%). The typical chest CT findings for COVID-19 pneumonia (ground-glass opacification) were bilateral in peripheral lung fields (91.58%), subpleural zones (1.98%), and central zones (0.59%). Among COVID-19-associated findings, septal thickening was found in 4(2.0%) cases, air bronchogram in 13(6.4%) cases, lung fibrosis in 3(1.5%) cases, the atelectatic in 5(2.5%) cases, pleural effusion in 15(7.4%) cases, and pulmonary embolism in 1(0.5%) case. There was no significant difference in the COVID-19-associated findings among different age groups and genders. Conclusion: Pleural effusion and air bronchogram were the most common findings associated with ground-glass opacification in unenhanced chest CT.

CT features and risk factors of pulmonary cement embolism after vertebroplasty or kyphoplasty in patients with vertebral compression fracture: a retrospective cohort study.

Pulmonary cement embolism (PCE) caused by cement leakage is one of the complications of percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). The aim of our study was to explore the imaging features on computed tomography (CT) and analyze the risk factors of PCE in patients with a vertebral compression fracture to compare the incidences of PCE caused by PVP and PKP. In this single-center, retrospective study, 373 patients (96 males and 277 females; mean age 76.2±9.4 years) from January 2017 to December 2020 who underwent PVP or PKP for treatment of vertebral compression fracture in the China-Japan Friendship Hospital were retrospectively included. Their clinical data were recorded, and their postprocedural chest CT scans were reviewed and evaluated for PCE. Of the 373 patients, 258 patients underwent PVP while the other 115 underwent PKP. PCE was found on the postprocedural chest CT scans in 64 patients (17.2%), including 47 patients with PVP and 17 patients with PKP. The incidence of PCE of PVP and PKP was similar (χ2=0.660; P=0.460). The typical CT findings of PCE were multiple linear or branching radiopaque densities in pulmonary arteries. The upper lobes of bilateral lungs were the most frequently involved. In addition, postprocedural chest CT demonstrated that 103 cases had cement emboli in the azygos vein, and 8 cases had cement emboli in the inferior vena cava. Binary logistic regression analysis demonstrated that PVP or PKP in the T9 vertebra [odds ratio (OR) =4.222; 95% CI: 1.490-11.966] and cement emboli in the azygos vein (OR =7.647; 95% CI: 3.937-14.856) or the inferior vena cava (OR =42.701; 95% CI: 7.525-242.302) were the risk factors of PCE. The incidence of PCE during PVP or PKP was 17.2%. Postprocedural chest CT clearly showed PCE as branching hyperdense or radiopaque lesions confined within the pulmonary artery courses. PVP or PKP in the T9 vertebra and cement emboli in the azygos vein or the inferior vena cava were risk factors for PCE.

Prognostic Performance of Shock Index, Diastolic Shock Index, Age Shock Index, and Modified Shock Index in COVID-19 Pneumonia.

We aimed to compare the prognostic accuracy of shock indexes in terms of mortality in patients hospitalized with coronavirus disease 2019 (COVID-19) pneumonia. Hospitalized patients whose COVID-19 reverse transcriptase-polymerase chain reaction (RT-PCR) test results were positive, had thoracic computed tomography (CT) scan performed, and had typical thoracic CT findings for COVID-19 were included in the study. Eight hundred one patients were included in the study. Chronic obstructive pulmonary disease, congestive heart failure, chronic neurological diseases, chronic renal failure, and a history of malignancy were found to be chronic diseases that were significantly associated with mortality in patients with COVID-19 pneumonia. White blood cell, neutrophil, lymphocyte, C reactive protein, creatinine, sodium, aspartate aminotransferase, alanine aminotransferase, total bilirubin, high sensitive troponin, d-dimer, hemoglobin, and platelet had a statistically significant relationship with in-hospital mortality in patients with COVID-19 pneumonia. The area under the curve (AUC) values of shock index (SI), age shock index (aSI), diastolic shock index (dSI), and modified shock index (mSI) calculated to predict mortality were 0.772, 0.745, 0.737, 0.755, and Youden Index J (YJI) values were 0.523, 0.396, 0.436, 0.452, respectively. The results of this study show that SI, dSI, mSI, and aSI are effective in predicting in-hospital mortality.

COVID-19 Pneumonia with Cavitation

The World Health Organization officially named the disease as Coronavirus Disease 2019 (COVID-19), which was caused by a new type of coronavirus that leads to viral pneumonia on 11 February 2020. Typical computed tomography findings of the disease are ground-glass infiltrations in both lungs. Atypical findings include lung cavitation and pleural effusion. A 43-year-old female patient was admitted to the emergency room with complaints of dry cough, fatigue, and joint pain for three days. Bilateral peripherally localized multisegmented ground-glass infiltrates were present in the first thorax tomography. A combined nasopharyngeal swab was taken from the patient and favipiravir and hydroxychloroquine treatment was initiated and she was sent home with the recommendation of isolation for 14 days. Real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) test performed on the same day and confirmed COVID-19 diagnosis. She was admitted to the hospital again with an increase in complaints five days after the first presentation and her oxygen saturation (SpO2) was found to be 90%. On the fifth day of her hospitalization, the patient was discharged because of clinical improvement. Two weeks later, she was brought to the emergency room with deterioration in her general condition. On thorax tomography of the patient, an area of necrotizing pneumonia with cavitation in the lower lobe of the right lung was observed. The patient was followed up in the intensive care unit for five days. After being followed up in the COVID service for five days, she was discharged because her respiratory distress, cough and C-reactive protein (CRP) was decreased. Lung cavitation due to COVID-19 pneumonia is rare, and most cases are self-limiting. Although the last rRT-PCR test of the patient is negative, the cavitary lesion in the lung can maintain contagiousness even if it is at a low level. Therefore, the extension of treatment and isolation time should be considered in such patients.

Features of primary pancreatic lymphoma: A bi-institutional review with an emphasis on typical and atypical imaging features.

BACKGROUNDPrimary pancreatic lymphoma (PPL) is a rare neoplasm. Being able to distinguish it from other pancreatic malignancies such as pancreatic ductal adenocarcinoma (PDAC) is important for appropriate management. Unlike PDAC, PPL is highly sensitive to chemotherapy and usually does not require surgery. Therefore, being able to identify PPL preoperatively will not only direct physicians towards the correct avenue of treatment, it will also avoid unnecessary surgical intervention.AIMTo evaluate the typical and atypical multi-phasic computed tomography (CT) imaging features of PPL.METHODSA retrospective review was conducted of the clinical, radiological, and pathological records of all subjects with pathologically proven PPL who presented to our institutions between January 2000 and December 2020. Institutional review board approval was obtained for this investigation. The collected data were analyzed for subject demographics, clinical presentation, laboratory values, CT imaging features, and the treatment received. Presence of all CT imaging findings including size, site, morphology and imaging characteristics of PPL such as the presence or absence of nodal, vascular and ductal involvement in these subjects were recorded. Only those subjects who had a pre-treatment multiphasic CT of the abdomen were included in the study.RESULTSTwenty-nine cases of PPL were diagnosed between January 2000 and December 2020 (mean age 66 years; 13 males/16 females). All twenty-nine subjects were symptomatic but only 4 of the 29 subjects (14%) had B symptoms. Obstructive jaundice occurred in 24% of subjects. Elevated lactate dehydrogenase was seen in 81% of cases, whereas elevated cancer antigen 19-9 levels were present in only 10% of cases for which levels were recorded. The vast majority (90%) of tumors involved the pancreatic head and uncinate process. Mean tumor size was 7.8 cm (range, 4.0-13.8 cm). PPL presented homogenous hypoenhancement on CT in 72% of cases. Small volume peripancreatic lymphadenopathy was seen in 28% of subjects. Tumors demonstrated encasement of superior mesenteric vessels in 69% of cases but vascular stenosis or occlusion only manifested in 5 out of the twenty-nine individuals (17%). Mild pancreatic duct dilatation was also infrequent and seen in only 17% of cases, whereas common bile duct (CBD) dilation was seen in 41% of subjects. Necrosis occurred in 10% of cases. Size did not impact the prevalence of pancreatic and CBD dilation, necrosis, or mesenteric root infiltration (P = 0.525, P = 0.294, P = 0.543, and P = 0.097, respectively). Pancreatic atrophy was not present in any of the subjects.CONCLUSIONPPL is an uncommon diagnosis best made preoperatively to avoid unnecessary surgery and ensure adequate treatment. In addition to the typical CT findings of PPL, such as homogeneous hypoenhancement, absence of vascular stenosis and occlusion despite encasement, and peripancreatic lymphadenopathy, this study highlighted many less typical findings, including small volume necrosis and pancreatic and bile duct dilation.

Acute kidney injury and mortality in coronavirus disease 2019: results from a cohort study of 1,280 patients.

BackgroundThe development of acute kidney injury (AKI) in patients with coronavirus disease 2019 (COVID-19) is associated with a high risk of death. Published data demonstrate the possibility of severe kidney injury in patients suffering from COVID-19. However, these data are still controversial.MethodsA total of 1,280 patients with a proven diagnosis of COVID-19 were included in our study. COVID-19 was confirmed in all patients using reverse transcriptase polymerase chain reaction test of a nasopharyngeal swab, and based on the typical computed tomography findings. Demographic data, underlying comorbidities, and laboratory blood tests were assessed. We assessed the incidence of AKI and its associated mortality defined by survival status at discharge.ResultsProteinuria was identified with 648 patients (50.6%) with COVID-19. AKI was identified in 371 patients (29.0%). Ten of these patients (2.7%) required dialysis. The risk factors for AKI included age of > 65 years, augmentation of C-reactive protein, ferritin and an increase in values of activated partial thromboplastin time. Overall, 162 of the 1,280 hospitalized patients (12.7%) and 111 of the 371 patients (29.9%) with AKI did not survive. The hazard ratio (HR) for mortality was 3.96 (95% confidence interval, 2.83–5.54) for patients with AKI vs. no AKI.ConclusionAKI was a relatively common finding among patients with COVID-19. The risk factors for AKI in COVID-19 included old age, the inflammatory response, the severity of lung involvement, and disseminated intravascular coagulation. These same factors, in addition to arterial hypertension, were found to increase the risk of mortality.

P31.01 A False Alarm of COVID-19 Pneumonia in Lung Cancer: A Case Report of Anti-PD-1 Related Pneumonitis

The inhibition of immune checkpoint therapy emerged as the novel treatment in advanced lung cancer, including anti-programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) antibodies. The fatal toxicity of anti-PD-1/PD-L1 agents is pneumonitis, which is defined as a noninfectious inflammation to the lung parenchyma. The diagnosis of pneumonitis consists of the history of immunotherapy, clinical symptoms and presentation of computed tomography (CT) imaging. The typical CT findings include ground-glass opacities.

Clinical, functional, and computed tomography findings in a cohort of patients with neuroendocrine cell hyperplasia of infancy.

Neuroendocrine cell hyperplasia of infancy (NEHI) is one of the most common interstitial lung diseases in children. Both the etiology and pathophysiological mechanisms of the disease are still unknown. Prognosis is usually favorable; however, there are significant morbidities during the early years of life. To describe the clinical course, infant pulmonary function tests and computed tomography (CT) findings in a cohort of patients with NEHI in Argentina. This is a observational multicenter cohort study of children diagnosed with NEHI between 2011 and 2020. Twenty patients participated in this study. The median age of onset of symptoms was 3 months and the median age at diagnosis was 6 months. The most common clinical presentation was tachypnea, retractions and hypoxemia. The chest CT findings showed central ground glass opacities and air trapping. Infant pulmonary function tests revealed an obstructive pattern in 75% of the cases (10/12). Most patients (75%) required home oxygen therapy for 17 months (interquartile range 12-25). In 85% of them, tachypnea and hypoxemia spontaneously resolved between the second and third years of life. In this cohort, the first symptoms appeared during the early months of life. The typical clinical, CT, and functional findings allowed the diagnosis without the need of a lung biopsy. Although most patients required home oxygen therapy, they showed a favorable evolution.

COVID-19 lungs in post-mortem computed tomography.

Post-mortem computed tomography (PMCT) is a rapid and noninvasive diagnostic tool for important contributions to the identification of pulmonary findings in the deceased with pneumonia, including cases of coronavirus disease 2019 (COVID-19). Although computed tomography (CT) shows a high sensitivity for pneumonia in living persons, it is relatively unspecific for COVID-19 pneumonia clinically. Typical CT findings for viral pneumonia therefore require confirmation by PCR tests (polymerase chain reaction tests), even if lung infections with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) show characteristic patterns, most frequently ground glass opacities (GGO) and a combination of GGO and air space consolidations.In the consecutive autopsy series of SARS-CoV‑2 deaths from Hamburg, Germany, the most frequent cause of death was and still is COVID-19 pneumonia. Typical findings were frequently found in the PMCT in SARS-CoV-2-associated deaths, which were taken into account when classifying the death as COVID-19.

Frequency of typical and atypical computed tomography findings of COVID-19 and their effect on hospitalization.

Objective:This study aimed to determine the frequency of typical and atypical computed tomography (CT) findings of COVID-19 and their effect on hospitalization.Methods:We retrospectively assessed 414 patients who were diagnosed with COVID-19 by real-time reverse transcription-polymerase chain reaction and who had lung involvement in their admission chest CT. We evaluated the frequency of typical and atypical chest CT findings and analyzed the relationship between typical and atypical findings of COVID-19 in patients treated in ambulatory versus inpatient settings.Results:Ground-glass opacities were the most common typical finding of COVID-19 chest CT scans. The frequencies of other typical findings, including consolidation, air bronchogram, pulmonary vascular enlargement (PVE), airway changes, crazy paving pattern, and reticular pattern, were similar to those reported in the literature. Atypical findings were less common and found at varying frequencies. Crazy paving pattern, air bronchogram, reticular pattern, and PVE were significantly more common in hospitalized patients (p<0.001). The frequencies of other typical and atypical findings were not significantly different between ambulatory and hospitalized patients.Conclusion:Increased recognition of typical and atypical findings of COVID-19 and their frequencies, as well as knowledge of admission chest CT findings that are associated with hospitalization, will facilitate medical care during the pandemic.

Differential diagnosis of coronavirus disease 2019 from community-acquired-pneumonia by computed tomography scan and follow-up

ObjectiveCoronavirus disease 2019 (COVID-19) is currently the most serious infectious disease in the world. An accurate diagnosis of this disease in the clinic is very important. This study aims to improve the differential ability of computed tomography (CT) to diagnose COVID-19 and other community-acquired pneumonias (CAPs) and evaluate the short-term prognosis of these patients.MethodsThe clinical and imaging data of 165 COVID-19 and 118 CAP patients diagnosed in seven hospitals in Anhui Province, China from January 21 to February 28, 2020 were retrospectively analysed. The CT manifestations of the two groups were recorded and compared. A correlation analysis was used to examine the relationship between COVID-19 and age, size of lung lesions, number of involved lobes, and CT findings of patients. The factors that were helpful in diagnosing the two groups of patients were identified based on specificity and sensitivity.ResultsThe typical CT findings of COVID-19 are simple ground-glass opacities (GGO), GGO with consolidation or grid-like changes. The sensitivity and specificity of the combination of age, white blood cell count, and ground-glass opacity in the diagnosis of COVID-19 were 92.7 and 66.1%, respectively. Pulmonary consolidation, fibrous cords, and bronchial wall thickening were used as indicators to exclude COVID-19. The sensitivity and specificity of the combination of these findings were 78.0 and 63.6%, respectively. The follow-up results showed that 67.8% (112/165) of COVID-19 patients had abnormal changes in their lung parameters, and the severity of the pulmonary sequelae of patients over 60 years of age worsened with age.ConclusionsAge, white blood cell count and ground-glass opacity have high accuracy in the early diagnosis of COVID-19 and the differential diagnosis from CAP. Patients aged over 60 years with COVID-19 have a poor prognosis. This result provides certain significant guidance for the diagnosis and treatment of new coronavirus pneumonia.

Chest CT Evaluation of 11 Persistent Asymptomatic Patients with SARS-CoV-2 Infection.

In total, 11 asymptomatic carriers who underwent nasal or oropharyngeal swab tests for SARS-CoV-2 after being in close contact with patients who developed symptomatic 2019 coronavirus disease (COVID-19) were enrolled in this study. The chest multidetector computed tomography (CT) images of the enrolled patients were qualitatively and quantitatively analyzed. The findings of the first chest CT were normal in 3 (27.3%) patients, 2 of whom were aged below 15 years. The lesions of 2 (18.2%) patients involved 1 lobe with unifocal presence. Subpleural lesions were observed in 7 (63.6%) patients. Ground glass opacity (GGO) was the most common sign observed in 7 (63.6%) patients. Crazy-paving pattern and consolidation were detected in 2 (18.2%) and 4 (36.4%) patients, respectively. Based on deep learning and quantitative analysis, the mean volume of intrapulmonary lesions in the first CT image was 85.73 ± 84.46 cm3. In patients with positive findings on CT images, the average interval between positive real-time reverse transcriptase polymerase chain reaction assay and peak volume on CT images was 5.1 ± 3.1 days. In conclusion, typical CT findings can be detected in over 70% of asymptomatic SARS-CoV-2 carriers. The initial presentation is typically GGO along the subpleural regions and bronchi, which absorbs in approximately 5 days.

Coronavirus disease 2019(COVID-19) imaging reporting and data system (COVID-RADS) and common lexicon: a proposal based on the imaging data of 37 studies.

BackgroundIn the vast majority of the laboratory-confirmed coronavirus disease 2019 (COVID-19) patients, computed tomography (CT) examinations yield a typical pattern and the sensitivity of this modality has been reported to be 97% in a large-scale study. Structured reporting systems simplify the interpretation and reporting of imaging examinations, serve as a framework for consistent generation of recommendations, and improve the quality of patient care.PurposeTo compose a comprehensive lexicon for description of the imaging findings and propose a grading system and structured reporting format for CT findings in COVID-19.Material and methodsWe updated our published systematic review on imaging findings in COVID-19 to include 37 published studies pertaining to diagnostic features of COVID-19 in chest CT. Using the reported imaging findings of 3647 patients, we summarized the typical chest CT findings, atypical features, and temporal changes of COVID-19 in chest CT. Subsequently, we extracted a list of descriptive terms and mapped it to the terminology that is commonly used in imaging literature.ResultsWe composed a comprehensive lexicon that can be used for documentation and reporting of typical and atypical CT imaging findings in COVID-19 patients. Using the same data, we propose a grading system with five COVID-RADS categories. Each COVID-RADS grade corresponds to a low, moderate, or high level of suspicion for pulmonary involvement of COVID-19.ConclusionThe proposed COVID-RADS and common lexicon would improve the communication of findings to other healthcare providers, thus facilitating the diagnosis and management of COVID-19 patients.Key Points• Chest CT has high sensitivity in diagnosing the coronavirus disease 2019 (COVID-19).• Structured reporting systems simplify the interpretation and reporting of imaging examinations, serve as a framework for consistent generation of recommendations, and improve the quality of patient care.• The proposed COVID-RADS and common lexicon would improve the communication of findings to other healthcare providers, thus facilitating the diagnosis and management of COVID-19 patients.

COVID-19 pneumonia: A review of typical CT findings and differential diagnosis

The standard of reference for confirming COVID-19 relies on microbiological tests such as real-time polymerase chain reaction (RT-PCR) or sequencing. However, these tests might not be available in an emergency setting. Computed tomography (CT) can be used as an important complement for the diagnosis of COVID-19 pneumonia in the current epidemic context. In this review, we present the typical CT features of COVID-19 pneumonia and discuss the main differential diagnosis.

Diagnosis of the Coronavirus disease (COVID-19): rRT-PCR or CT?

PurposeTo evaluate the diagnostic value of computed tomography (CT) and real-time reverse-transcriptase-polymerase chain reaction (rRT-PCR) for COVID-19 pneumonia. MethodsThis retrospective study included all patients with COVID-19 pneumonia suspicion, who were examined by both CT and rRT-PCR at initial presentation. The sensitivities of both tests were then compared. For patients with a final confirmed diagnosis, clinical and laboratory data, in addition to CT imaging findings were evaluated. ResultsA total of 36 patients were finally diagnosed with COVID-19 pneumonia. Thirty-five patients had abnormal CT findings at presentation, whereas one patient had a normal CT. Using rRT-PCR, 30 patients were tested positive, with 6 cases initially missed. Amongst these 6 patients, 3 became positive in the second rRT-PCR assay(after 2 days, 2 days and 3 days respectively), and the other 3 became positive only in the third round of rRT-PCR tests(after 5 days, 6 days and 8 days respectively). At presentation, CT sensitivity was therefore 97.2%, whereas the sensitivity of initial rRT-PCR was only 83.3%. ConclusionrRT-PCR may produce initial false negative results. We suggest that patients with typical CT findings but negative rRT-PCR results should be isolated, and rRT-PCR should be repeated to avoid misdiagnosis.

A case of gastric duplication presenting as a retroperitoneal cystic lesion

Gastric duplication is a rare congenital anomaly accounting to 4% of all gastrointestinal tract duplications. It is usually diagnosed pre-natally or during infancy. Retroperitoneal gastric duplication is very rare in adult patients. It is generally asymptomatic or presents with non-specific symptoms. The sensitivity of classical imaging modalities for retroperitoneal gastric duplication is weak. Retroperitoneal gastric duplication could be misdiagnosed as other retroperitoneal cystic lesions and it could be definitely diagnosed by typical findings of abdominal enhanced computed tomography (CT) and endoscopic ultrasonography (EUS) plus EUS:guided fine needle aspiration biopsy in gastric duplicated cyst. A female adult patient was diagnosed by an exceptional hospital CT as retroperitoneal cystic lesion and was admitted in our hospital in March 2019. The abdominal enhanced CT in our hospital preoperatively indicated a cystic lesion above the left kidney and the maximum cross section was 9.0 cm×5.2 cm. Lymphocysts and others should be identified and the lesion might be from the stomach. The retroperitoneal gastric duplication was not diagnosed before operation. In the operation laparoscopy revealed the cystic lesion in the retroperitoneum. The pancreas, left adrenal gland, and left kidney were compressed by the cystic lesion. The top of the lesion was connected with the small curvature of the stomach, but it was not communicated with the stomach. The retroperitoneal cystic lesion was completely excised and the surrounding organs were not damaged. The retroperitoneal gastric duplication was clearly diagnosed by the findings in the operation and the pathology of the lesion. The patient was discharged a week after surgery without gastrointestinal and pancreatic injuries. Therefore, the differential diagnosis of retroperitoneal cysts should consider the possibility of retroperitoneal gastric duplication. For patients with typical CT findings or unclear boundaries between the tumor and the stomach wall, gastric duplication could be diagnosed by EUS plus EUS:guided fine needle aspiration biopsy in the cyst. Retroperitoneal gastric duplication cyst could be completely excised by laparoscopy through abdominal cavity and the stomach wall could be completely repaired.