Heterotopic ossification and COVID 19: Imaging analysis of ten consecutive cases.

PURPOSE: Heterotopic ossification (HO) is defined by the formation of mature lamellar bone in periarticular soft tissue due to prolonged immobility. This study aimed to explore the imaging features of HOs in immobilized COVID-19 patients compared to other causes previously described in the literature. METHOD: This retrospective single centre study included patients with severe COVID-19 hospitalized in intensive care unit (ICU) with mechanical ventilation and affected by HOs between March 2020 and December 2021. Two radiologists reviewed imaging features of biphasic CT-scans using a standardized template including morphological findings and anatomical relationship of the HO with the joint, vessels and nerves. RESULTS: 10 COVID-19 patients with 19 analyzed HOs following ICU hospitalization were including. Biphasic CT imaging characteristics were analyzed. The hips were the most commonly affected joint (n = 14/19; 74%). The distribution was mainly posterior (n = 7/19; 38%). HOs were located away from main arteries. No case of severe demineralization was observed. Capsular disruption was observed for three HOs (n = 3/19; 16%). One patient presented concomitant venous thrombosis ipsilateral to the HO. CT-scan demonstrated neural involvement of the sciatic nerve in 3 patients with HO (n = 3/19; 16%). CONCLUSION: Severe COVID-19 patients with a biphasic CT imaging presented HO mainly located around the hips, with rare vessel and nerve invasion and no severe demineralization. Some features such as a lower level of local invasion differ from HOs related to other disorders as described in the literature whereas morphological aspects are similar.

Pre-test probability for SARS-Cov-2-related infection score: The PARIS score.

INTRODUCTION: In numerous countries, large population testing is impossible due to the limited availability of RT-PCR kits and CT-scans. This study aimed to determine a pre-test probability score for SARS-CoV-2 infection. METHODS: This multicenter retrospective study (4 University Hospitals) included patients with clinical suspicion of SARS-CoV-2 infection. Demographic characteristics, clinical symptoms, and results of blood tests (complete white blood cell count, serum electrolytes and CRP) were collected. A pre-test probability score was derived from univariate analyses of clinical and biological variables between patients and controls, followed by multivariate binary logistic analysis to determine the independent variables associated with SARS-CoV-2 infection. RESULTS: 605 patients were included between March 10th and April 30th, 2020 (200 patients for the training cohort, 405 consecutive patients for the validation cohort). In the multivariate analysis, lymphocyte (<1.3 G/L), eosinophil (<0.06 G/L), basophil (<0.04 G/L) and neutrophil counts (<5 G/L) were associated with high probability of SARS-CoV-2 infection but no clinical variable was statistically significant. The score had a good performance in the validation cohort (AUC = 0.918 (CI: [0.891-0.946]; STD = 0.014) with a Positive Predictive Value of high-probability score of 93% (95%CI: [0.89-0.96]). Furthermore, a low-probability score excluded SARS-CoV-2 infection with a Negative Predictive Value of 98% (95%CI: [0.93-0.99]). The performance of the score was stable even during the last period of the study (15-30th April) with more controls than infected patients. CONCLUSIONS: The PARIS score has a good performance to categorize the pre-test probability of SARS-CoV-2 infection based on complete white blood cell count. It could help clinicians adapt testing and for rapid triage of patients before test results.

Contribution of Interventional Radiologist in the Management of Pseudoaneurysm and Neck Hemorrhages in COVID-19 patients.

Patients with severe coronavirus disease 2019 (COVID-19) may have endothelial inflammation, pseudoaneurysm, and an increasing risk of bleeding, especially during surgical procedures. In this article, we reported 2 cases of COVID-19 patients with neck vascular lesions. The first patient had pseudoaneurysm of the cricothyroid artery, which was treated by percutaneous glue injection through ultrasonography guidance. The second patient presented lateral neck hematoma in front of the left superior thyroid artery, which was managed by coil endovascular embolization. In the context of pandemic, the management of vascular lesions may be performed through interventional radiological procedures that may reduce the risk of virus aerosolization and health care provider contamination.

Determining extent of COVID-19 pneumonia on CT based on biological variables.

INTRODUCTION: Covid-19 pneumonia CT extent correlates well with outcome including mortality. However, CT is not widely available in many countries. This study aimed to explore the relationship between Covid-19 pneumonia CT extent and blood tests variations. The objective was to determine for the biological variables correlating with disease severity the cut-off values showing the best performance to predict the parenchymal extent of the pneumonia. METHODS: Bivariate correlations were calculated between biological variables and grade of disease extent on CT. Receiving Operating Characteristic curve analysis determined the best cutoffs for the strongest correlated biological variables. The performance of these variables to predict mild (<10%) or severe pneumonia (>50% of parenchyma involved) was evaluated. RESULTS: Correlations between biological variables and disease extent was evaluated in 168 patients included in this study. LDH, lymphocyte count and CRP showed the strongest correlations (with 0.67, -0.41 and 0.52 correlation coefficient, respectively). Patients were split into a training and a validation cohort according to their centers. If one variable was above/below the following cut-offs, LDH>380, CRP>80 or lymphocyte count <0.8G/L, severe pneumonia extent on CT was detected with 100% sensitivity. Values above/below all three thresholds were denoted in 73% of patients with severe pneumonia extent. The combination of LDH<220 and CRP<22 was associated with mild pneumonia extent (<10%) with specificity of 100%. DISCUSSION: LDH showed the strongest correlation with the extent of Covid-19 pneumonia on CT. Combined with CRP±lymphocyte count, it helps predicting parenchymal extent of the pneumonia when CT scan is not available.

AI-driven quantification, staging and outcome prediction of COVID-19 pneumonia.

Coronavirus disease 2019 (COVID-19) emerged in 2019 and disseminated around the world rapidly. Computed tomography (CT) imaging has been proven to be an important tool for screening, disease quantification and staging. The latter is of extreme importance for organizational anticipation (availability of intensive care unit beds, patient management planning) as well as to accelerate drug development through rapid, reproducible and quantified assessment of treatment response. Even if currently there are no specific guidelines for the staging of the patients, CT together with some clinical and biological biomarkers are used. In this study, we collected a multi-center cohort and we investigated the use of medical imaging and artificial intelligence for disease quantification, staging and outcome prediction. Our approach relies on automatic deep learning-based disease quantification using an ensemble of architectures, and a data-driven consensus for the staging and outcome prediction of the patients fusing imaging biomarkers with clinical and biological attributes. Highly promising results on multiple external/independent evaluation cohorts as well as comparisons with expert human readers demonstrate the potentials of our approach.

Occurrence of pulmonary embolism related to COVID-19.

Recent reports have suggested an increased risk of pulmonary embolism (PE) related to COVID-19. The aim of this cohort study is to compare the incidence of PE during a 3-year period and to assess the characteristics of PE in COVID-19. We studied consecutive patients presenting with PE (January 2017-April 2020). Clinical presentation, computed tomography (CT) and biological markers were systematically assessed. We recorded the global number of hospitalizations during the COVID-19 pandemic and during the same period in 2018-2019. We included 347 patients: 326 without COVID-19 and 21 with COVID-19. Patients with COVID-19 experienced more likely dyspnea (p=0.04), had lower arterial oxygen saturation (p<0.001), higher C-reactive protein and white blood cell (WBC) count (p<0.0001 and p=0.001, respectively), and a significantly higher in-hospital mortality (14% versus 3.4%, p=0.04). Among COVID-19 patients, diagnosis of PE was performed at admission in 38% (n=8). COVID-19 patients with diagnosis of PE during hospitalization (n=13) had significantly more dyspnea (p=0.04), lower arterial oxygen saturation (p=0.01), less proximal PE (p=0.02), and higher heart rate (p=0.009), CT severity score (p=0.001), C-reactive protein (p=0.006) and WBC count (p=0.04). During the COVID-19 outbreak, a 97.4% increase of PE incidence was observed as compared to 2017-2019 and the proportion of hospitalizations related to PE was 3.7% versus 1.3% in 2018-2019 (p<0.0001). In conclusion, the COVID-19 pandemic leads to a dramatic increased incidence of PE. Physicians should be aware that PE may be diagnosed at admission, but also after several days of hospitalization, with a different clinical, CT and biological features of thrombotic disease.

18-FDG PSEUDOTUMORAL LESION WITH QUICK FLOWERING TO A TYPICAL LUNG CT COVID-19.

As coronavirus pandemic continues to spread over the world, physicians have to be aware of atypical features of COVID-19 pneumonia. We report the case of a 78-year-old man presenting with pseudo-tumoral focal lesion of the left lung which switched shortly to severe and diffuse COVID-19 induced pneumonia. Nuclear medicine physicians and radiologists should be careful of some misleading hypermetabolic aspects mostly in asymptomatic patients.

Arterial and venous abdominal thrombosis in a 79-year-old woman with COVID-19 pneumonia.

As coronavirus pandemic continue to spread over the world, we have to be aware of potential complications on hospitalized patients. We report a case of a 79-year-old woman with COVID-19 pneumonia complicated by combined arterial and venous thrombosis of upper mesenteric vessels. As unenhanced chest CT scan plays a key role in managing the COVID-19 pandemic, we should pay attention to indirect signs of thrombosis.