Liver involvement in patients with COVID-19 infection: A comprehensive overview of diagnostic imaging features

During the first wave of the pandemic, coronavirus disease 2019 (COVID-19) infection has been considered mainly as a pulmonary infection. However, different clinical and radiological manifestations were observed over time, including involvement of abdominal organs. Nowadays, the liver is considered one of the main affected abdominal organs. Hepatic involvement may be caused by either a direct damage by the virus or an indirect damage related to COVID-19 induced thrombosis or to the use of different drugs. After clinical assessment, radiology plays a key role in the evaluation of liver involvement. Ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) may be used to evaluate liver involvement. US is widely available and it is considered the first-line technique to assess liver involvement in COVID-19 infection, in particular liver steatosis and portal-vein thrombosis. CT and MRI are used as second- and third-line techniques, respectively, considering their higher sensitivity and specificity compared to US for assessment of both parenchyma and vascularization. This review aims to the spectrum of COVID-19 liver involvement and the most common imaging features of COVID-19 liver damage

Embolization in Pediatric Patients: A Comprehensive Review of Indications, Procedures, and Clinical Outcomes

Embolization in pediatric patients encompasses a large spectrum of indications, ranging from the elective treatment of congenital diseases of the cardiovascular system to the urgent management of acute hemorrhagic conditions. In particular, the endovascular treatment of central and peripheral vascular malformations and hypervascular tumors represents a wide chapter for both congenital and acquired situations. Thanks to the progressive availability of low-profile endovascular devices and new embolic materials, the mini-invasive approach has gradually overtaken surgery. In this review, the main embolization procedures will be illustrated and discussed, with a focus on clinical indications and expected outcomes. The most recent mini-invasive techniques will be described, with hints on the cutting-edge devices and embolic materials

Diagnostic Accuracy of 256-Detector Row Computed Tomography in Detection and Characterization of Incidental Pancreatic Cystic Lesions

Purpose. To assess the diagnostic value of 256-detector row MDCT in the characterization of incidentally detected pancreatic cystic lesions (PCLs). Materials and Methods. We retrospectively reviewed 6389 studies performed on a 256-row detector scanner, wherein ≥1 PCLs were incidentally detected. Images from a total of 192 patients (99 females; age range 31–90 years) were analysed referring to morphologic predictive signs of malignancy, including multifocality, inner septa, wall thickening, and mural enhancing nodules. Results. We evaluated 292 PCLs in 192 patients (solitary in 145 and ≥2 in 47; incidence 2.05%). Size ranged from 3 to 145 mm (mean 15 mm); body was the most common location (87/292; 29.8%). Intralesional septa were detected in 52/292 lesions (17.8%), wall thickening >2 mm in 13 (4.5%), enhancing wall and mural nodules in 15 (5.1%) and 12 (4.1%), respectively. Communication with ductal system was evident in 45 cases. The most common diagnoses, established by histology or imaging analysis, were IPMNs (about 86%), while serous cystic neoplasia (3.7%) and metastases (0.5%) were the less common. Conclusion. MDCT provides detailed features for characterization of PCLs, which are incidentally discovered with increased frequency due to the widespread use of cross-sectional imaging

Embolisation of the parenchymal tract after percutaneous portal vein catheterization: a retrospective comparison of outcomes with different techniques in two centres

Background: Embolisation of the parenchymal tract is a key step after any other transhepatic or transplenic percutaneous portal vein catheterization since eventual venous bleeding is difficult to control and may require surgical management. Different techniques have been proposed to perform tract embolisation. The aim of this study is to compare the safety and efficacy of different techniques of haemostasis of the parenchymal tract. Materials and methods: All the interventional procedures with percutaneous transhepatic or transplenic access to the portal vein (excluding ipsilateral portal vein embolisation) from January 2010 to July 2020, in two tertiary hospitals, were retrospectively analyzed. The following data were evaluated: access site, the technique of embolisation, technical success in terms of immediate thrombosis of the tract, safety and clinical efficacy in terms of the absence of hemorrhagic and thrombotic complications. Results: One-hundred-sixty-one patients underwent 220 percutaneous transhepatic or transplenic portal vein catheterization procedures. The main indications were pancreatic islet transplantation, portal anastomotic stenosis after liver transplantation, and portal vein thrombosis recanalization. As embolic materials gelfoam was used in 105 cases, metallic micro-coils in 54 cases, and cyanoacrylic glue in 44 cases; in 17 cases the parenchymal tract was not embolized. Technical success was 98% without significant difference among groups (p-value = 0.22). Eighteen post-procedural abdominal bleedings occurred, all grade 3 and were managed conservatively; difference among groups was not significant (p-value = 0.25). We detected 12 intrahepatic portal branch thromboses not related to the embolisation technique; only one case of non-target embolisation was documented after liver tract embolisation with glue, without clinical consequences. Conclusion: Embolisation of the parenchymal tract after percutaneous portal vein catheterization is technically safe and effective. No significant differences were found between coils, glue, and gelfoam in effectiveness and complications rate. Level of evidence: Level 3, Cohort study

Convolutional neural networks for PET functional volume fully automatic segmentation : development and validation in a multi-center setting

Purpose: In this work, we addressed fully automatic determination of tumor functional uptake from positron emission tomography (PET) images without relying on other image modalities or additional prior constraints, in the context of multicenter images with heterogeneous characteristics. Methods: In cervical cancer, an additional challenge is the location of the tumor uptake near or even stuck to the bladder. PET datasets of 232 patients from five institutions were exploited. To avoid unreliable manual delineations, the ground truth was generated with a semi-automated approach: a volume containing the tumor and excluding the bladder was first manually determined, then a well-validated, semi-automated approach relying on the Fuzzy locally Adaptive Bayesian (FLAB) algorithm was applied to generate the ground truth. Our model built on the U-Net architecture incorporates residual blocks with concurrent spatial squeeze and excitation modules, as well as learnable non-linear downsampling and upsampling blocks. Experiments relied on cross-validation (four institutions for training and validation, and the fifth for testing). Results: The model achieved good Dice similarity coefficient (DSC) with little variability across institutions (0.80 ± 0.03), with higher recall (0.90 ± 0.05) than precision (0.75 ± 0.05) and improved results over the standard U-Net (DSC 0.77 ± 0.05, recall 0.87 ± 0.02, precision 0.74 ± 0.08). Both vastly outperformed a fixed threshold at 40% of SUVmax (DSC 0.33 ± 0.15, recall 0.52 ± 0.17, precision 0.30 ± 0.16). In all cases, the model could determine the tumor uptake without including the bladder. Neither shape priors nor anatomical information was required to achieve efficient training. Conclusion: The proposed method could facilitate the deployment of a fully automated radiomics pipeline in such a challenging multicenter context

Impact of clinical and subclinical coronary artery disease as assessed by coronary artery calcium in COVID-19

Background and aims: The potential impact of coronary atherosclerosis, as detected by coronary artery calcium, on clinical outcomes in COVID-19 patients remains unsettled. We aimed to evaluate the prognostic impact of clinical and subclinical coronary artery disease (CAD), as assessed by coronary artery calcium score (CAC), in a large, unselected population of hospitalized COVID-19 patients undergoing non-gated chest computed tomography (CT) for clinical practice. Methods: SARS-CoV 2 positive patients from the multicenter (16 Italian hospitals), retrospective observational SCORE COVID-19 (calcium score for COVID-19 Risk Evaluation) registry were stratified in three groups: (a) “clinical CAD” (prior revascularization history), (b) “subclinical CAD” (CAC >0), (c) “No CAD” (CAC = 0). Primary endpoint was in-hospital mortality and the secondary endpoint was a composite of myocardial infarction and cerebrovascular accident (MI/CVA). Results: Amongst 1625 patients (male 67.2%, median age 69 [interquartile range 58–77] years), 31%, 57.8% and 11.1% had no, subclinical and clinical CAD, respectively. Increasing rates of in-hospital mortality (11.3% vs. 27.3% vs. 39.8%, p < 0.001) and MI/CVA events (2.3% vs. 3.8% vs. 11.9%, p < 0.001) were observed for patients with no CAD vs. subclinical CAD vs clinical CAD, respectively. The association with in-hospital mortality was independent of in-study outcome predictors (age, peripheral artery disease, active cancer, hemoglobin, C-reactive protein, LDH, aerated lung volume): subclinical CAD vs. No CAD: adjusted hazard ratio (adj-HR) 2.86 (95% confidence interval [CI] 1.14–7.17, p=0.025); clinical CAD vs. No CAD: adj-HR 3.74 (95% CI 1.21–11.60, p=0.022). Among patients with subclinical CAD, increasing CAC burden was associated with higher rates of in-hospital mortality (20.5% vs. 27.9% vs. 38.7% for patients with CAC score thresholds≤100, 101–400 and > 400, respectively, p < 0.001). The adj-HR per 50 points increase in CAC score 1.007 (95%CI 1.001–1.013, p=0.016). Cardiovascular risk factors were not independent predictors of in-hospital mortality when CAD presence and extent were taken into account. Conclusions: The presence and extent of CAD are associated with in-hospital mortality and MI/CVA among hospitalized patients with COVID-19 disease and they appear to be a better prognostic gauge as compared to a clinical cardiovascular risk assessment

Coronary and total thoracic calcium scores predict mortality and provides pathophysiologic insights in COVID-19 patients

Background: Coronavirus disease 2019 (COVID-19) has spread worldwide determining dramatic impacts on healthcare systems. Early identification of high-risk parameters is required in order to provide the best therapeutic approach. Coronary, thoracic aorta and aortic valve calcium can be measured from a non-gated chest computer tomography (CT) and are validated predictors of cardiovascular events and all-cause mortality. However, their prognostic role in acute systemic inflammatory diseases, such as COVID-19, has not been investigated. Objectives: The aim was to evaluate the association of coronary artery calcium and total thoracic calcium on in-hospital mortality in COVID-19 patients. Methods: 1093 consecutive patients from 16 Italian hospitals with a positive swab for COVID-19 and an admission chest CT for pneumonia severity assessment were included. At CT, coronary, aortic valve and thoracic aorta calcium were qualitatively and quantitatively evaluated separately and combined together (total thoracic calcium) by a central Core-lab blinded to patients’ outcomes. Results: Non-survivors compared to survivors had higher coronary artery [Agatston (467.76 ​± ​570.92 vs 206.80 ​± ​424.13 ​mm2, p ​< ​0.001); Volume (487.79 ​± ​565.34 vs 207.77 ​± ​406.81, p ​< ​0.001)], aortic valve [Volume (322.45 ​± ​390.90 vs 98.27 ​± ​250.74 mm2, p ​< ​0.001; Agatston 337.38 ​± ​414.97 vs 111.70 ​± ​282.15, p ​< ​0.001)] and thoracic aorta [Volume (3786.71 ​± ​4225.57 vs 1487.63 ​± ​2973.19 mm2, p ​< ​0.001); Agatston (4688.82 ​± ​5363.72 vs 1834.90 ​± ​3761.25, p ​< ​0.001)] calcium values. Coronary artery calcium (HR 1.308; 95% CI, 1.046–1.637, p ​= ​0.019) and total thoracic calcium (HR 1.975; 95% CI, 1.200–3.251, p ​= ​0.007) resulted to be independent predictors of in-hospital mortality. Conclusion: Coronary, aortic valve and thoracic aortic calcium assessment on admission non-gated CT permits to stratify the COVID-19 patients in-hospital mortality risk