Mitral Annular Disease at Cardiac MRI: What to Know and Look For.

Accurate evaluation of the mitral valve (MV) apparatus is essential for understanding the mechanisms of MV disease across various clinical scenarios. The mitral annulus (MA) is a complex and crucial structure that supports MV function; however, conventional imaging techniques have limitations in fully capturing the entirety of the MA. Moreover, recognizing annular changes might aid in identifying patients who may benefit from advanced cardiac imaging and interventions. Multimodality cardiovascular imaging plays a major role in the diagnosis, prognosis, and management of MV disease. Transthoracic echocardiography is the first-line modality for evaluation of the MA, but it has limitations. Cardiac MRI (CMR) has emerged as a robust imaging modality for assessing annular changes, with distinct advantages over other imaging techniques, including accurate flow and volumetric quantification and assessment of variations in the measurements and shape of the MA during the cardiac cycle. Mitral annular disjunction (MAD) is defined as atrial displacement of the hinge point of the MV annulus away from the ventricular myocardium, a condition that is now more frequently diagnosed and studied owing to recent technical advances in cardiac imaging. However, several unresolved issues regarding MAD, such as the functional significance of pathologic disjunction and how this disjunction advances in the clinical course, require further investigation. The authors review the role of CMR in the assessment of MA disease, with a focus on MAD and its functional implications in MV prolapse and mitral regurgitation. ©RSNA, 2024 Supplemental material is available for this article. See the invited commentary by Stojanovska and Fujikura in this issue.

Hospital admission and mortality rates for non-COVID-19 respiratory diseases in Brazil's public health system during the covid-19 pandemic: a nationwide observational study.

OBJECTIVE: To assess the influence of the COVID-19 pandemic on hospital admissions (HA), intra-hospital deaths (HD), and intra-hospital lethality rates (HL) related to respiratory diseases (RD) other than COVID-19 in Brazil. METHODS: This observational time-series study was conducted through comparative analyses of the HA, HD, and HL related to non-COVID-19 RD registered between March and December 2020 by the Brazilian Unified Public Health System on the DataSUS Tabnet platform, using as reference the values recorded in the same period of 2019 and those projected by linear regression methods for 2020, considering the period from 2015 to 2019. The adopted statistical significance level was 5% (p < 0.05). RESULTS: Compared to 2019, in 2020, there was a 42% decrease in HA and a 7.4% decrease in total HD related to non-COVID-19 RD, followed by a 60% increase in HL associated with this group of diseases. The HA and HL registered in 2020 differed significantly from the projected trend for that year by linear regression (p < 0.05). Of note, a significant reduction in hospitalizations due to asthma (-46%), chronic obstructive pulmonary disease (-45%), bronchiectasis (-54%), pneumonia (-46%), and acute bronchitis (-73%) was observed. CONCLUSIONS: During the first 8 months of the pandemic, there was a decline in HA and an increase in HL related to non-COVID-19 RD in Brazil, which can hypothetically reflect logistical challenges and delays in the management of this group of diseases.

Current status and future perspectives of radiomics in hepatocellular carcinoma.

Given the frequent co-existence of an aggressive tumor and underlying chronic liver disease, the management of hepatocellular carcinoma (HCC) patients requires experienced multidisciplinary team discussion. Moreover, imaging plays a key role in the diagnosis, staging, restaging, and surveillance of HCC. Currently, imaging assessment of HCC entails the assessment of qualitative characteristics which are prone to inter-reader variability. Radiomics is an emerging field that extracts high-dimensional mineable quantitative features that cannot be assessed visually with the naked eye from medical imaging. The main potential applications of radiomic models in HCC are to predict histology, response to treatment, genetic signature, recurrence, and survival. Despite the encouraging results to date, there are challenges and limitations that need to be overcome before radiomics implementation in clinical practice. The purpose of this article is to review the main concepts and challenges pertaining to radiomics, and to review recent studies and potential applications of radiomics in HCC.

Hepatic involvement in hereditary hemorrhagic telangiectasia mimicking focal nodular hyperplasia.

Accurate diagnosis of hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber disease, is important for reducing the risk of complications. Hepatic involvement in HHT is usually asymptomatic, but when present can cause noted morbidity and mortality. A 62-year-old woman presented with moderate upper-abdominal pain and tachycardia. A diagnosis of HHT was made based on the findings of hepatic involvement in a contrast-enhanced abdominal computed tomography (CT) scan, the presence of arteriovenous malformations (AVMs; a.k.a. telangiectasias) on mucocutaneous surfaces, and a history of recurrent epistaxis. Imaging methods are important diagnostic tools in patients suspected of having HHT.

Hospital admission and mortality rates for non-COVID-19 respiratory diseases in Brazil's public health system during the covid-19 pandemic: a nationwide observational study / Internações hospitalares e taxas de mortalidade por doenças respiratórias não COVID-19 no sistema público de saúde do Brasil durante a pandemia de COVID-19: um estudo observacional nacional

ABSTRACT Objective: To assess the influence of the COVID-19 pandemic on hospital admissions (HA), intra-hospital deaths (HD), and intra-hospital lethality rates (HL) related to respiratory diseases (RD) other than COVID-19 in Brazil. Methods: This observational time-series study was conducted through comparative analyses of the HA, HD, and HL related to non-COVID-19 RD registered between March and December 2020 by the Brazilian Unified Public Health System on the DataSUS Tabnet platform, using as reference the values recorded in the same period of 2019 and those projected by linear regression methods for 2020, considering the period from 2015 to 2019. The adopted statistical significance level was 5% (p < 0.05). Results: Compared to 2019, in 2020, there was a 42% decrease in HA and a 7.4% decrease in total HD related to non-COVID-19 RD, followed by a 60% increase in HL associated with this group of diseases. The HA and HL registered in 2020 differed significantly from the projected trend for that year by linear regression (p < 0.05). Of note, a significant reduction in hospitalizations due to asthma (-46%), chronic obstructive pulmonary disease (-45%), bronchiectasis (-54%), pneumonia (-46%), and acute bronchitis (-73%) was observed. Conclusions: During the first 8 months of the pandemic, there was a decline in HA and an increase in HL related to non-COVID-19 RD in Brazil, which can hypothetically reflect logistical challenges and delays in the management of this group of diseases.

RESUMO Objetivo: Avaliar a influência da pandemia de COVID-19 nas taxas de internações hospitalares (IH), óbitos intra-hospitalares (OH) e letalidade intra-hospitalar (LH) relacionadas a outras doenças respiratórias (DR) que não a COVID-19 no Brasil. Métodos: Este estudo observacional de série temporal foi realizado por meio da análise comparativa das IH, OH e LH relacionadas a DR não COVID-19 registradas entre março e dezembro de 2020 pelo Sistema Único de Saúde na plataforma DataSUS Tabnet, tendo como referência o valores registrados no mesmo período de 2019 e aqueles projetados pelos métodos de regressão linear para 2020, considerando o período de 2015 a 2019. O nível de significância estatística adotado foi de 5% (p < 0,05). Resultados: Comparado a 2019, em 2020, houve uma redução de 42% nas IH e de 7,4% nos OH totais relacionados a DR não COVID-19, seguido de um aumento de 60% nas taxas de LH associadas a esse grupo de doenças. As IH e as taxas de LH registradas em 2020 diferiram significantemente da tendência projetada para aquele ano por regressão linear (p < 0,05). Vale ressaltar que foi observada uma redução significativa das internações por asma (-46%), doença pulmonar obstrutiva crônica (-45%), bronquiectasia (-54%), pneumonia (-46%) e bronquite aguda (-73%). Conclusão: Durante os primeiros 8 meses da pandemia, houve um declínio nas IH e um aumento das taxas de LH relacionadas a DR não COVID-19 no Brasil, o que pode, hipoteticamente, refletir desafios logísticos e atrasos no manejo desse grupo de doenças.

Hepatobiliary phases in magnetic resonance imaging using liver-specific contrast for focal lesions in clinical practice.

BACKGROUND: Challenging lesions, difficult to diagnose through non-invasive methods, constitute an important emotional burden for each patient regarding a still uncertain diagnosis (malignant x benign). In addition, from a therapeutic and prognostic point of view, delay in a definitive diagnosis can lead to worse outcomes. One of the main innovative trends currently is the use of molecular and functional methods to diagnosis. Numerous liver-specific contrast agents have been developed and studied in recent years to improve the performance of liver magnetic resonance imaging (MRI). More recently, one of the contrast agents introduced in clinical practice is gadoxetic acid (gadoxetate disodium). AIM: To demonstrate the value of the hepatobiliary phases using gadoxetic acid in MRI for the characterization of focal liver lesions (FLL) in clinical practice. METHODS: Overall, 302 Lesions were studied in 136 patients who underwent MRI exams using gadoxetic acid for the assessment of FLL. Two radiologists independently reviewed the MRI exams using four stages, and categorized them on a 6-point scale, from 0 (lesion not detected) to 5 (definitely malignant). The stages were: stage 1- images without contrast, stage 2- addition of dynamic phases after contrast (analogous to usual extracellular contrasts), stage 3- addition of hepatobiliary phase after 10 min (HBP 10'), stage 4- hepatobiliary phase after 20 min (HBP 20') in addition to stage 2. RESULTS: The interobserver agreement was high (weighted Kappa coefficient: 0.81- 1) at all stages in the characterization of benign and malignant FLL. The diagnostic weighted accuracy (Az) was 0.80 in stage 1 and was increased to 0.90 in stage 2. Addition of the hepatobiliary phase increased Az to 0.98 in stage 3, which was also 0.98 in stage 4. CONCLUSION: The hepatobiliary sequences improve diagnostic accuracy. With growing potential in the era of precision medicine, the improvement and dissemination of the method among medical specialties can bring benefits in the management of patients with FLL that are difficult to diagnose.

Multimodal integration of radiology, pathology and genomics for prediction of response to PD-(L)1 blockade in patients with non-small cell lung cancer.

Immunotherapy is used to treat almost all patients with advanced non-small cell lung cancer (NSCLC); however, identifying robust predictive biomarkers remains challenging. Here we show the predictive capacity of integrating medical imaging, histopathologic and genomic features to predict immunotherapy response using a cohort of 247 patients with advanced NSCLC with multimodal baseline data obtained during diagnostic clinical workup, including computed tomography scan images, digitized programmed death ligand-1 immunohistochemistry slides and known outcomes to immunotherapy. Using domain expert annotations, we developed a computational workflow to extract patient-level features and used a machine-learning approach to integrate multimodal features into a risk prediction model. Our multimodal model (area under the curve (AUC) = 0.80, 95% confidence interval (CI) 0.74-0.86) outperformed unimodal measures, including tumor mutational burden (AUC = 0.61, 95% CI 0.52-0.70) and programmed death ligand-1 immunohistochemistry score (AUC = 0.73, 95% CI 0.65-0.81). Our study therefore provides a quantitative rationale for using multimodal features to improve prediction of immunotherapy response in patients with NSCLC using expert-guided machine learning.

SARS-CoV-2 and splenic infarction: a rarely described thromboembolic presentation.

We report the case of a COVID-19 patient presenting with fever, headache and dyspnea, evolving with severe acute abdominal pain. A contrast-enhanced computed tomography (CT) scan diagnosed splenic infarction. We emphasize the importance of seeking the identification of complications of SARS-CoV-2 infection, notably thromboembolic events, with the potential to reduce the morbidity and mortality of the disease. Studies on radiological aspects involving the spleen and splenic infarctions associated with COVID-19 are rare.

Rectal MRI radiomics for predicting pathological complete response: Where we are.

Radiomics using rectal MRI radiomics has emerged as a promising approach in predicting pathological complete response. In this study, we present a typical pipeline of a radiomics analysis and review recent studies, exploring applications, development of radiomics methodologies and model construction in pCR prediction. Finally, we will offer our opinion about the future and discuss the next steps of rectal MRI radiomics for predicting pCR.

Lung Lesion Burden found on Chest CT as a Prognostic Marker in Hospitalized Patients with High Clinical Suspicion of COVID-19 Pneumonia: a Brazilian experience.

OBJECTIVE: To investigate the relationship between lung lesion burden (LLB) found on chest computed tomography (CT) and 30-day mortality in hospitalized patients with high clinical suspicion of coronavirus disease 2019 (COVID-19), accounting for tomographic dynamic changes. METHODS: Patients hospitalized with high clinical suspicion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a dedicated and reference hospital for COVID-19, having undergone at least one RT-PCR test, regardless of the result, and with one CT compatible with COVID-19, were retrospectively studied. Clinical and laboratory data upon admission were assessed, and LLB found on CT was semi-quantitatively evaluated through visual analysis. The primary outcome was 30-day mortality after admission. Secondary outcomes, including the intensive care unit (ICU) admission, mechanical ventilation used, and length of stay (LOS), were assessed. RESULTS: A total of 457 patients with a mean age of 57±15 years were included. Among these, 58% presented with positive RT-PCR result for COVID-19. The median time from symptom onset to RT-PCR was 8 days [interquartile range 6-11 days]. An initial LLB of ≥50% using CT was found in 201 patients (44%), which was associated with an increased crude at 30-day mortality (31% vs. 15% in patients with LLB of <50%, p<0.001). An LLB of ≥50% was also associated with an increase in the ICU admission, the need for mechanical ventilation, and a prolonged LOS after adjusting for baseline covariates and accounting for the CT findings as a time-varying covariate; hence, patients with an LLB of ≥50% remained at a higher risk at 30-day mortality (adjusted hazard ratio 2.17, 95% confidence interval 1.47-3.18, p<0.001). CONCLUSION: Even after accounting for dynamic CT changes in patients with both clinical and imaging findings consistent with COVID-19, an LLB of ≥50% might be associated with a higher risk of mortality.

A machine learning framework for the evaluation of myocardial rotation in patients with noncompaction cardiomyopathy.

AIMS: Noncompaction cardiomyopathy (NCC) is considered a genetic cardiomyopathy with unknown pathophysiological mechanisms. We propose to evaluate echocardiographic predictors for rigid body rotation (RBR) in NCC using a machine learning (ML) based model. METHODS AND RESULTS: Forty-nine outpatients with NCC diagnosis by echocardiography and magnetic resonance imaging (21 men, 42.8±14.8 years) were included. A comprehensive echocardiogram was performed. The layer-specific strain was analyzed from the apical two-, three, four-chamber views, short axis, and focused right ventricle views using 2D echocardiography (2DE) software. RBR was present in 44.9% of patients, and this group presented increased LV mass indexed (118±43.4 vs. 94.1±27.1g/m2, P = 0.034), LV end-diastolic and end-systolic volumes (P< 0.001), E/e' (12.2±8.68 vs. 7.69±3.13, P = 0.034), and decreased LV ejection fraction (40.7±8.71 vs. 58.9±8.76%, P < 0.001) when compared to patients without RBR. Also, patients with RBR presented a significant decrease of global longitudinal, radial, and circumferential strain. When ML model based on a random forest algorithm and a neural network model was applied, it found that twist, NC/C, torsion, LV ejection fraction, and diastolic dysfunction are the strongest predictors to RBR with accuracy, sensitivity, specificity, area under the curve of 0.93, 0.99, 0.80, and 0.88, respectively. CONCLUSION: In this study, a random forest algorithm was capable of selecting the best echocardiographic predictors to RBR pattern in NCC patients, which was consistent with worse systolic, diastolic, and myocardium deformation indices. Prospective studies are warranted to evaluate the role of this tool for NCC risk stratification.

Radiomic analysis of MRI to Predict Sustained Complete Response after Radiofrequency Ablation in Patients with Hepatocellular Carcinoma - A Pilot Study.

OBJECTIVES: To investigate whether quantitative textural features, extracted from pretreatment MRI, can predict sustained complete response to radiofrequency ablation (RFA) in patients with hepatocellular carcinoma (HCC). METHODS: In this IRB-approved study, patients were selected from a maintained six-year database of consecutive patients who underwent both pretreatment MRI imaging with a probable or definitive imaging diagnosis of HCC (LI-RADS 4 or 5) and loco-regional treatment with RFA. An experienced radiologist manually segmented the hepatic nodules in MRI arterial and equilibrium phases to obtain the volume of interest (VOI) for extraction of 107 quantitative textural features, including shape and first- and second-order features. Statistical analysis was performed to evaluate associations between textural features and complete response. RESULTS: The study consisted of 34 patients with 51 treated hepatic nodules. Sustained complete response was achieved by 6 patients (4 with single nodule and 2 with multiple nodules). Of the 107 features from the arterial and equilibrium phases, 20 (18%) and 25 (23%) achieved AUC >0.7, respectively. The three best performing features were found in the equilibrium phase: Dependence Non-Uniformity Normalized and Dependence Variance (both GLDM class, with AUC of 0.78 and 0.76, respectively) and Maximum Probability (GLCM class, AUC of 0.76). CONCLUSIONS: This pilot study demonstrates that a radiomic analysis of pre-treatment MRI might be useful in identifying patients with HCC who are most likely to have a sustained complete response to RFA. Second-order features (GLDM and GLCM) extracted from equilibrium phase obtained highest discriminatory performance.

Redução na Hospitalização e Aumento na Mortalidade por Doenças Cardiovasculares durante a Pandemia da COVID-19 no Brasil / Reduction in Hospitalization and Increase in Mortality Due to Cardiovascular Diseases during the COVID-19 Pandemic in Brazil

Resumo Fundamento Na pandemia pela COVID-19, o aumento da ocorrência e da mortalidade por doenças cardiovasculares (DCV) vem sendo reconhecido no mundo. No Brasil, é essencial que o impacto da COVID-19 na DCV seja analisado. Objetivos Avaliar o impacto desta pandemia nos números de internações hospitalares (IH), óbitos hospitalares (OH) e letalidade intra-hospitalar (LH) por DCV a partir de dados epidemiológicos do Sistema Único de Saúde (SUS). Métodos Estudo observacional de séries temporais por meio da análise comparativa das taxas de IH, OH e LH por DCV registrados entre janeiro e maio de 2020, usando como referência os valores obtidos no mesmo período entre 2016 e 2019 e os valores projetados por métodos de regressão linear para o ano de 2020. O nível significância estatística utilizado foi de 0,05. Resultados Em comparação com o mesmo período de 2019, houve um decréscimo de 15% na taxa de IH e de 9% no total de OH por DCV entre março e maio de 2020, acompanhado de um aumento de 9% na taxa de LH por esse grupo de doenças, sobretudo entre pacientes com idade de 20-59 anos. As taxas de IH e LH registradas em 2020 diferiram significativamente da tendência projetada para o corrente ano (p=0,0005 e 0,0318, respectivamente). Conclusões Durante os primeiros meses da pandemia, observou-se um declínio na IH associado a um aumento da LH por DCV no Brasil. Esses dados possivelmente são consequência do planejamento inadequado no manejo das DCV durante a pandemia, sendo necessária a implementação de ações imediatas para modificar esse cenário. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0)

Abstract Background In the COVID-19 pandemic, the increase in the incidence of cardiovascular diseases (CVD) and mortality from them has been recognized worldwide. In Brazil, the impact of COVID-19 on CVD must be evaluated. Objectives To assess the impact of the current pandemic on the numbers of hospital admissions (HA), in-hospital deaths (ID), and in-hospital fatality (IF) from CVD by use of national epidemiological data from the Brazilian Unified Public Health System. Methods Time-series observational study using comparative analysis of the HA, ID, and IF due to CVD recorded from January to May 2020, having as reference the values registered in the same period from 2016 to 2019 and the values projected by linear regression methods for 2020. The statistical significance level applied was 0.05. Results Compared to the same period in 2019, there was a 15% decrease in the HA rate and a 9% decrease in the total ID due to CVD between March and May 2020, followed by a 9% increase in the IF rate due to CVD, especially among patients aged 20-59 years. The HA and IF rates registered in 2020 differed significantly from the projected trend for 2020 (p = 0.0005 and 0.0318, respectively). Conclusions During the first months of the pandemic, there were a decline in HA and an increase in IF due to CVD in Brazil. These data might have resulted from the inadequate planning of the CVD management during the pandemic. Thus, immediate actions are required to change this scenario. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0)

Reduction in Hospitalization and Increase in Mortality Due to Cardiovascular Diseases during the COVID-19 Pandemic in Brazil. / Redução na Hospitalização e Aumento na Mortalidade por Doenças Cardiovasculares durante a Pandemia da COVID-19 no Brasil.

BACKGROUND: In the COVID-19 pandemic, the increase in the incidence of cardiovascular diseases (CVD) and mortality from them has been recognized worldwide. In Brazil, the impact of COVID-19 on CVD must be evaluated. OBJECTIVES: To assess the impact of the current pandemic on the numbers of hospital admissions (HA), in-hospital deaths (ID), and in-hospital fatality (IF) from CVD by use of national epidemiological data from the Brazilian Unified Public Health System. METHODS: Time-series observational study using comparative analysis of the HA, ID, and IF due to CVD recorded from January to May 2020, having as reference the values registered in the same period from 2016 to 2019 and the values projected by linear regression methods for 2020. The statistical significance level applied was 0.05. RESULTS: Compared to the same period in 2019, there was a 15% decrease in the HA rate and a 9% decrease in the total ID due to CVD between March and May 2020, followed by a 9% increase in the IF rate due to CVD, especially among patients aged 20-59 years. The HA and IF rates registered in 2020 differed significantly from the projected trend for 2020 (p = 0.0005 and 0.0318, respectively). CONCLUSIONS: During the first months of the pandemic, there were a decline in HA and an increase in IF due to CVD in Brazil. These data might have resulted from the inadequate planning of the CVD management during the pandemic. Thus, immediate actions are required to change this scenario. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0).

FUNDAMENTO: Na pandemia pela COVID-19, o aumento da ocorrência e da mortalidade por doenças cardiovasculares (DCV) vem sendo reconhecido no mundo. No Brasil, é essencial que o impacto da COVID-19 na DCV seja analisado. OBJETIVOS: Avaliar o impacto desta pandemia nos números de internações hospitalares (IH), óbitos hospitalares (OH) e letalidade intra-hospitalar (LH) por DCV a partir de dados epidemiológicos do Sistema Único de Saúde (SUS). MÉTODOS: Estudo observacional de séries temporais por meio da análise comparativa das taxas de IH, OH e LH por DCV registrados entre janeiro e maio de 2020, usando como referência os valores obtidos no mesmo período entre 2016 e 2019 e os valores projetados por métodos de regressão linear para o ano de 2020. O nível significância estatística utilizado foi de 0,05. RESULTADOS: Em comparação com o mesmo período de 2019, houve um decréscimo de 15% na taxa de IH e de 9% no total de OH por DCV entre março e maio de 2020, acompanhado de um aumento de 9% na taxa de LH por esse grupo de doenças, sobretudo entre pacientes com idade de 20-59 anos. As taxas de IH e LH registradas em 2020 diferiram significativamente da tendência projetada para o corrente ano (p=0,0005 e 0,0318, respectivamente). CONCLUSÕES: Durante os primeiros meses da pandemia, observou-se um declínio na IH associado a um aumento da LH por DCV no Brasil. Esses dados possivelmente são consequência do planejamento inadequado no manejo das DCV durante a pandemia, sendo necessária a implementação de ações imediatas para modificar esse cenário. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0).

Abdominal gastrointestinal imaging findings on computed tomography in patients with COVID-19 and correlation with clinical outcomes.

PURPOSE: Pulmonary imaging finding of Coronavirus disease 2019 (COVID-19) has been widely described, but until now few studies have been published about abdominal radiological presentation. The aim of this study was to provide an overview of abdominal imaging findings in patients with COVID-19 in a multicenter study and correlate them with worse clinical outcomes. MATERIALS AND METHODS: This retrospective study included adult COVID-positive patients with abdominal CT performed from 4/1/2020 to 5/1/2020 from two institutions. Demographic, laboratory and clinical data were recorded, including clinical outcomes. RESULTS: Of 81 COVID-positive patients, the average age was 61 years, 42 (52%) women and 45 (55%) had positive abdominopelvic findings. The most common abdominal imaging features were intestinal imaging findings (20/81, 24%), including colorectal (4/81, 5%) and small bowel thickening (10/81, 12%), intestinal distension (15/81, 18%), pneumatosis (1/81, 1%) and intestinal perforation (1/81, 1%). On multivariate analysis, intestinal imaging findings were associated with higher risk of worse outcome (death or invasive mechanical ventilation) (RR = 2.6, p = 0.04) and higher risk of invasive mechanical ventilation alone (RR = 6.2, p = 0.05). CONCLUSION: Intestinal abnormalities were common findings in COVID-19 patients who underwent abdominal CT and were significantly correlated to worse outcomes in the clinical follow-up.

Lung lesion burden found on chest ct as a prognostic marker in hospitalized patients with high clinical suspicion of COVID-19 pneumonia: a brazilian experience

OBJECTIVE: To investigate the relationship between lung lesion burden (LLB) found on chest computed tomography (CT) and 30-day mortality in hospitalized patients with high clinical suspicion of coronavirus disease 2019 (COVID-19), accounting for tomographic dynamic changes. METHODS: Patients hospitalized with high clinical suspicion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a dedicated and reference hospital for COVID-19, having undergone at least one RT-PCR test, regardless of the result, and with one CT compatible with COVID-19, were retrospectively studied. Clinical and laboratory data upon admission were assessed, and LLB found on CT was semi-quantitatively evaluated through visual analysis. The primary outcome was 30-day mortality after admission. Secondary outcomes, including the intensive care unit (ICU) admission, mechanical ventilation used, and length of stay (LOS), were assessed. RESULTS: A total of 457 patients with a mean age of 57±15 years were included. Among these, 58% presented with positive RT-PCR result for COVID-19. The median time from symptom onset to RT-PCR was 8 days [interquartile range 6-11 days]. An initial LLB of ≥50% using CT was found in 201 patients (44%), which was associated with an increased crude at 30-day mortality (31% vs. 15% in patients with LLB of <50%, p<0.001). An LLB of ≥50% was also associated with an increase in the ICU admission, the need for mechanical ventilation, and a prolonged LOS after adjusting for baseline covariates and accounting for the CT findings as a time-varying covariate; hence, patients with an LLB of ≥50% remained at a higher risk at 30-day mortality (adjusted hazard ratio 2.17, 95% confidence interval 1.47-3.18, p<0.001). CONCLUSION: Even after accounting for dynamic CT changes in patients with both clinical and imaging findings consistent with COVID-19, an LLB of ≥50% might be associated with a higher risk of mortality.

Radiomic analysis of mri to predict sustained complete response after radiofrequency ablation in patients with hepatocellular carcinoma - a pilot study

OBJECTIVES: To investigate whether quantitative textural features, extracted from pretreatment MRI, can predict sustained complete response to radiofrequency ablation (RFA) in patients with hepatocellular carcinoma (HCC). METHODS: In this IRB-approved study, patients were selected from a maintained six-year database of consecutive patients who underwent both pretreatment MRI imaging with a probable or definitive imaging diagnosis of HCC (LI-RADS 4 or 5) and loco-regional treatment with RFA. An experienced radiologist manually segmented the hepatic nodules in MRI arterial and equilibrium phases to obtain the volume of interest (VOI) for extraction of 107 quantitative textural features, including shape and first- and second-order features. Statistical analysis was performed to evaluate associations between textural features and complete response. RESULTS: The study consisted of 34 patients with 51 treated hepatic nodules. Sustained complete response was achieved by 6 patients (4 with single nodule and 2 with multiple nodules). Of the 107 features from the arterial and equilibrium phases, 20 (18%) and 25 (23%) achieved AUC >0.7, respectively. The three best performing features were found in the equilibrium phase: Dependence Non-Uniformity Normalized and Dependence Variance (both GLDM class, with AUC of 0.78 and 0.76, respectively) and Maximum Probability (GLCM class, AUC of 0.76). CONCLUSIONS: This pilot study demonstrates that a radiomic analysis of pre-treatment MRI might be useful in identifying patients with HCC who are most likely to have a sustained complete response to RFA. Second-order features (GLDM and GLCM) extracted from equilibrium phase obtained highest discriminatory performance.