Reliability of extracellular contrast versus gadoxetic acid in assessing small liver lesions using liver imaging reporting and data system v.2018 and European association for the study of the liver criteria.

BACKGROUND & AIMS: The diagnostic accuracy of Liver Imaging Reporting and Data System (LI-RADS) v.2018 and European Association for the Study of the Liver (EASL) criteria for the diagnosis of HCC have been widely evaluated, but their reliability should be investigated. We aimed to assess and compare the reliability of LI-RADS v.2018 and EASL criteria for the diagnosis of HCC using MRI with extracellular contrast agents (ECAs) and gadoxetic acid (GA) and determine the effect of ancillary features on LI-RADS reliability. APPROACH & RESULTS: Ten readers reviewed MRI studies of 92 focal liver lesions measuring <3 cm acquired with ECAs and GA <1 month apart from two prospective trials, assessing EASL criteria, LI-RADS major and ancillary features, and LI-RADS categorization with and without including ancillary features. Inter-reader agreement for definite HCC diagnosis was substantial and similar for the two contrasts for both EASL and LI-RADS criteria. For ECA-MRI and GA-MRI, respectively, inter-reader agreement was k = 0.72 (95% CI, 0.63-0.81) and k = 0.72 (95% CI, 0.63-0.80); for nonrim hyperenhancement, k = 0.63 (95% CI, 0.54-0.72) and k = 0.57 (95% CI, 0.48-0.66); and for nonperipheral washout, k = 0.49 (95% CI, 0.40-0.59) and k = 0.48 (95% CI, 0.37-0.58) for enhancing capsule. The inter-reader agreement for LI-RADS after applying ancillary features remained in the same range of agreement. CONCLUSIONS: Agreement for definite HCC was substantial and similar for both scoring systems and the two contrast agents in small focal liver lesions. Agreement for LI-RADS categorization was lower for both contrast agents, and including LI-RADS ancillary features did not improve agreement.

Undefined/non-malignant hepatic nodules are associated with early occurrence of HCC in DAA-treated patients with HCV-related cirrhosis.

BACKGROUND & AIM: An unexpected early increase in incidence, recurrence and clinical aggressiveness of hepatocellular carcinoma (HCC) has been reported (and refuted) in patients with HCV-related cirrhosis following direct-acting antiviral (DAA) treatment. To address this controversy, we performed a prospective multicenter study on consecutively enrolled cirrhotic patients, with or without a history of HCC, undergoing DAA therapy. PATIENTS AND METHODS: A total of 1,161 HCC-free cirrhotics (group 1) and 124 cirrhotics who had received a curative treatment for an HCC (group 2) were enrolled. Clinical features, including presence of undefined/non-malignant liver nodules (UNMNs), were analyzed with respect to HCC incidence and recurrence. RESULTS: During a median study time of 17 months in group 1 and 16 months in group 2, de novo HCC developed in 48 patients (yearly incidence 3.1/100 patient-years, 75% BCLC 0-A) and recurred in 40 (mean yearly incidence 29.9/100 patient-years, 83% BCLC 0-A). A peak of HCC instant incidence was observed at 4.2 months in group 1 patients with UNMNs, and at 7.7 months in group 2. By multivariable Cox regression models, UNMNs (hazard ratio [HR] 3.11; 95% CI 1.47-6.57: p = 0.003), ascites detected any time before enrolment (HR 3.04; 95% CI 1.23-7.51; p = 0.02), and alpha-fetoprotein log-value (HR 1.90; 95% CI 1.05-3.44; p = 0.03) were the variables independently associated with the incidence of de novo HCC, while history of alcohol abuse (HR 2.10; 95% CI 1.08-4.09; p = 0.03) and history of recurrence of HCC (HR 2.87; 95% CI 1.35-6.09; p = 0.006) were associated with HCC recurrence. CONCLUSION: An early high incidence of both de novo HCC, in patients with UNMNs, and recurrent HCC was observed in DAA-treated patients; this was not accompanied by increased tumor aggressiveness. LAY SUMMARY: This prospective study focuses on the risk of developing de novo or recurrent hepatocellular carcinoma (HCC) after direct-acting antiviral (DAA) treatment in patients with hepatitis C-related cirrhosis. We found that DAA treatment was associated with an early high HCC incidence in patients with undefined or non-malignant nodules, as well as in those with a history of complete response to HCC treatment. Whether this is related to the presence of clinically undetectable nests of cancer cells or to precancerous lesions that may progress to overt HCC upon DAA treatment remains unanswered. No evidence of increased clinical aggressiveness was reported in de novo or recurrent HCC.

Characterization of liver nodules in patients with chronic liver disease by MRI: performance of the Liver Imaging Reporting and Data System (LI-RADS v.2018) scale and its comparison with the Likert scale.

OBJECTIVES: To evaluate the performance of the LI-RADS v.2018 scale by comparing it with the Likert scale, in the characterization of liver lesions. METHODS: A total of 39 patients with chronic liver disease underwent MR examination for characterization of 44 liver lesions. Images were independently analyzed by two radiologists using the LI-RADS scale and by another two radiologists using the Likert scale. The reference standard used was either histopathological evaluation or a 4-year MRI follow-up. Receiver operating characteristic analysis was performed. RESULTS: The LI-RADS scale obtained an accuracy of 80%, a sensitivity of 72%, a specificity of 93%, a positive predictive value (PPV) of 93% and a negative predictive value (NPV) of 70%, while the Likert scale achieved an accuracy of 79%, a sensitivity of 73%, a specificity of 87%, a PPV of 89% and a NPV of 70%. The area under the curve (AUC) was 85% for the LI-RADS scale and 83% for the Likert scale. The inter-observer agreement was strong (k = 0.89) between the LI-RADS evaluators and moderate (k = 0.69) between the Likert evaluators. CONCLUSIONS: There was no statistically significant difference between the performances of the two scales; nevertheless, we suggest that the LI-RADS scale be used, as it appeared more objective and consistent.

Preparation of a radiology department in an Italian hospital dedicated to COVID-19 patients.

Preparedness for the ongoing coronavirus disease 2019 (COVID-19) and its spread in Italy called for setting up of adequately equipped and dedicated health facilities to manage sick patients while protecting healthcare workers, uninfected patients, and the community. In our country, in a short time span, the demand for critical care beds exceeded supply. A new sequestered hospital completely dedicated to intensive care (IC) for isolated COVID-19 patients needed to be designed, constructed, and deployed. Along with this new initiative, the new concept of "Pandemic Radiology Unit" was implemented as a practical solution to the emerging crisis, born out of a critical and urgent acute need. The present article describes logistics, planning, and practical design issues for such a pandemic radiology and critical care unit (e.g., space, infection control, safety of healthcare workers, etc.) adopted in the IC Hospital Unit for the care and management of COVID-19 patients.

Contrast imaging techniques to diagnose hepatocellular carcinoma in cirrhotics outside regular surveillance.

INTRODUCTION AND AIM: The American Association for the Study of the Liver (AASLD) recommends contrast computerized tomography (CT-scan) and magnetic resonance (MRI) to diagnose hepatocellular carcinoma (HCC) arising in cirrhotic patients under semiannual surveillance with abdominal ultrasound (US). A US guided fine needle biopsy (FNB) serves the same purpose in radiologically undiagnosed tumors and incidentally detected nodules in cirrhotics outside surveillance. In this population, we evaluated the performance of radiological diagnosis of HCC according to 2010 AASLD recommendations. MATERIALS AND METHODS: All cirrhotic patients with a liver nodule incidentally detected by US were prospectively investigated with a sequential application of CT-scan/MRI examination and a FNB. RESULTS: Between 2011 and 2015, 94 patients (mean age 67 years) had a liver nodule (total 120) detected by US in the context of histologically confirmed cirrhosis. Mean nodules diameter was 40 (10-160) mm, 87 (73%) <5cm. At histology, 84 (70%) nodules were HCC, 8 (7%) intrahepatic cholangiocarcinoma, 6 (5%) metastases, 2 (2%) neuroendocrine tumors and 20 (16%) benign lesions. Hyperenhancement in arterial phase followed by wash-out in venous phases on at least one radiological technique was demonstrated in 62 nodules (61 HCC, 1 high grade dysplastic nodule), with a specificity of 97% (IC95%: 85-100%), sensitivity 73% (IC95%: 62-81%) and diagnostic accuracy 80%, being 64% for ≥5cm HCC. Sensitivity of AFP >200ng/mL was 12% (IC95%: 6-23%). CONCLUSION: A single contrast imaging technique showing a typical contrast pattern confidently identifies HCC also in cirrhotic patients with an incidental liver nodule, thereby reducing the need for FNB examinations.

Multimodality treatment of hepatocellular carcinoma: How field practice complies with international recommendations.

BACKGROUND: Management of hepatocellular carcinoma (HCC) is framed within standardized protocols released by Scientific Societies, whose applicability and efficacy in field practice need refining. AIM: We evaluated the applicability and effectiveness of guidelines for the treatment of HCC of the American Association for the Study of the Liver (AASLD). METHODS: 370 consecutive cirrhotic patients with de novo HCC in different stages, 253 BCLC A, 66 BCLC B, 51 BCLC C received treatment through a multidisciplinary team (MDT) decision and were followed until death or end of follow-up. RESULTS: Treatment was adherent to AASLD recommendations in 205 (81%) BCLC A patients, 36 (54%) BCLC B, and 27 (53%) BCLC C. Radiological complete response was achieved in 165 (45%) patients after the first-line treatment, in 22 (19%) after a second-line and in 9 (23%) after a third-line treatment. Adherence to AASLD recommendation allowed a lower yearly mean mortality rate in BCLC A patients compared with other treatment (5.0% vs 10.4% P = .004), whereas upward treatment stage migration compared with the standard of care was associated with reduced yearly mortality in BCLC B (8.6% vs 20.7%, P = .029) and BCLC C (42.6% vs 59.0%, P = .04) patients. CONCLUSIONS: HCC multimodality treatment including other than first-line therapy is common in clinical practice and impact on the achievement of complete response. Personalized treatment was able to provide survival benefits to patients whose profile is not accounted for by international recommendations, which need to be amended.

Computational Fluid-Dynamic Analysis after Carotid Endarterectomy: Patch Graft versus Direct Suture Closure.

BACKGROUND: Closure technique after carotid endarterectomy (CEA) still remains an issue of debate. Routine use of patch graft (PG) has been advocated to reduce restenosis, stroke, and death, but its protective effect, particularly from late restenosis, is less evident and recent studies call into question this thesis. This study aims to compare PG and direct suture (DS) by means of computational fluid dynamics (CFD). To identify carotid regions with flow recirculation more prone to restenosis development, we analyzed time-averaged oscillatory shear index (OSI) and relative residence time (RRT), that are well-known indices correlated with plaque formation. METHODS: CFD was performed in 12 patients (13 carotids) who underwent surgery for stenosis >70%, 9 with PG, and 4 with DS. Flow conditions were modeled using patient-specific boundary conditions derived from Doppler ultrasound and geometries from magnetic resonance angiography. RESULTS: Mean value of the spatial averaged OSI resulted 0.07 for PG group and 0.03 for DS group, the percentage of area with OSI above a threshold of 0.2 resulted 10.1% and 3.7%, respectively. The mean of averaged-in-space RRT values was 4.4 1/Pa for PG group and 1.6 1/Pa for DS group, the percentage of area with RRT values above a threshold of 4 1/Pa resulted 22.5% and 6.5%, respectively. CONCLUSIONS: Both OSI and RRT values resulted higher when PG was preferred to DS and also areas with disturbed flow resulted wider. The absolute higher values computed by means of CFD were observed when PG was used indiscriminately regardless of carotid diameters. DS does not seem to create negative hemodynamic conditions with potential adverse effects on long-term outcomes, in particular when CEA is performed at the common carotid artery and/or the bulb or when ICA diameter is greater than 5.0 mm.

Cholangiocarcinoma in Cirrhosis: Value of Hepatocyte Specific Magnetic Resonance Imaging.

BACKGROUND: The diagnosis of intrahepatic cholangiocellular carcinoma (ICC) remains elusive at imaging, which is a critical issue in cirrhotic patients in whom a diagnosis of hepatocellular carcinoma (HCC) can be established only by imaging. AIM: The aim of the study was to evaluate the potential of MRI in the diagnosis of ICC in cirrhosis using 'hepatocyte-specific' Gadolinium (Gd)-based contrast agents. METHODS: Sixteen histologically proven and retrospectively identified ICCs on cirrhosis were investigated with hepatocyte-specific magnetic resonance contrast agents (6 in Bologna with Gd-EOB-DTPA and 10 in Milan with Gd-BOPTA). The control group consisted of 41 consecutively and prospectively collected nodules (31 HCCs) imaged with Gd-EOB-DTPA. RESULTS: Fifteen ICC nodules (94%) displayed hypointensity in the hepatobiliary phase, suggesting malignancy. Thirteen cholangiocarcinomas (81%) showed hyperenhancement in the venous phase. Only 2 cholangiocarcinoma nodules showed hypoenhancement in the venous phase, corresponding to washout, in both cases preceded by rim enhancement in arterial phase. All the hepatocarcinomas showed hypointensity in hepatobiliary phase, but was always preceded by hypointensity in the venous phase; arterial rim enhancement was never observed in any hepatocarcinoma or regenerative nodule. CONCLUSIONS: MRI with hepatocyte-specific Gd-based contrast agents showed a pattern of malignancy in almost all the ICCs, concurrently avoiding misdiagnosis with hepatocarcinoma. These findings suggest a greater diagnostic capacity for this technique compared with the results of MRI with conventional contrast agents reported in the literature in this setting.

Radiologists' perceptions on AI integration: An in-depth survey study.

PURPOSE: To assess the perceptions and attitudes of radiologists toward the adoption of artificial intelligence (AI) in clinical practice. METHODS: A survey was conducted among members of the SIRM Lombardy. Radiologists' attitudes were assessed comprehensively, covering satisfaction with AI-based tools, propensity for innovation, and optimism for the future. The questionnaire consisted of two sections: the first gathered demographic and professional information using categorical responses, while the second evaluated radiologists' attitudes toward AI through Likert-type responses ranging from 1 to 5 (with 1 representing extremely negative attitudes, 3 indicating a neutral stance, and 5 reflecting extremely positive attitudes). Questionnaire refinement involved an iterative process with expert panels and a pilot phase to enhance consistency and eliminate redundancy. Exploratory data analysis employed descriptive statistics and visual assessment of Likert plots, supported by non-parametric tests for subgroup comparisons for a thorough analysis of specific emerging patterns. RESULTS: The survey yielded 232 valid responses. The findings reveal a generally optimistic outlook on AI adoption, especially among young radiologist (<30) and seasoned professionals (>60, p<0.01). However, while 36.2 % (84 out 232) of subjects reported daily use of AI-based tools, only a third considered their contribution decisive (30 %, 25 out of 84). AI literacy varied, with a notable proportion feeling inadequately informed (36 %, 84 out of 232), particularly among younger radiologists (46 %, p < 0.01). Positive attitudes towards the potential of AI to improve detection, characterization of anomalies and reduce workload (positive answers > 80 %) and were consistent across subgroups. Radiologists' opinions were more skeptical about the role of AI in enhancing decision-making processes, including the choice of further investigation, and in personalized medicine in general. Overall, respondents recognized AI's significant impact on the radiology profession, viewing it as an opportunity (61 %, 141 out of 232) rather than a threat (18 %, 42 out of 232), with a majority expressing belief in AI's relevance to future radiologists' career choices (60 %, 139 out of 232). However, there were some concerns, particularly among breast radiologists (20 of 232 responders), regarding the potential impact of AI on the profession. Eighty-four percent of the respondents consider the final assessment by the radiologist still to be essential. CONCLUSION: Our results indicate an overall positive attitude towards the adoption of AI in radiology, though this is moderated by concerns regarding training and practical efficacy. Addressing AI literacy gaps, especially among younger radiologists, is essential. Furthermore, proactively adapting to technological advancements is crucial to fully leverage AI's potential benefits. Despite the generally positive outlook among radiologists, there remains significant work to be done to enhance the integration and widespread use of AI tools in clinical practice.

Portal hypertension-like pattern in coronavirus disease 2019 acute respiratory distress syndrome.

OBJECTIVES: Although respiratory failure is the most common feature in coronavirus disease 2019 (COVID-19), abdominal organ involvement is likewise frequently observed. To investigate visceral and thoracic circulation and abdominal organ damage in COVID-19 patients. MATERIALS AND METHODS: A monocentric observational study was carried on. In COVID-19 patients affected by acute respiratory distress syndrome (ARDS) (n = 31) or mild pneumonia (n = 60) thoracoabdominal circulation was evaluated using Doppler-ultrasound and computed tomography. The study also included non-COVID-19 patients affected by ARDS (n = 10) or portal hypertension (n = 10) for comparison of the main circulatory changes. RESULTS: Patients affected by COVID-19 ARDS showed hyperdynamic visceral flow and increased portal velocity, hepatic artery resistance-index, and spleen diameter relative to those with mild-pneumonia (p = 0.001). Splanchnic circulatory parameters significantly correlated with the main respiratory indexes (p < 0.001) and pulmonary artery diameter (p = 0.02). The chest and abdominal vascular remodeling pattern of COVID-19 ARDS patients resembled the picture observed in the PH group, while differed from that of the non-COVID ARDS group. A more severe COVID-19 presentation was associated with worse liver dysfunction and enhanced inflammatory activation; these parameters both correlated with abdominal (p = 0.04) and chest imaging measures (p = 0.03). CONCLUSION: In COVID-19 ARDS patients there are abdominal and lung vascular modifications that depict a portal hypertension-like pattern. The correlation between visceral vascular remodeling, pulmonary artery enlargement, and organ damage in these critically ill patients is consistent with a portal hyperlfow-like syndrome that could contribute to the peculiar characteristics of respiratory failure in these patients. CLINICAL RELEVANCE STATEMENT: our data suggest that the severity of COVID-19 lung involvement is directly related to the development of a portal hyperflow-like syndrome. These observations should help in defining the need for a closer monitoring, but also to develop dedicated therapeutic strategies.

Contrast enhanced CT-scan to diagnose intrahepatic cholangiocarcinoma in patients with cirrhosis.

BACKGROUND & AIMS: Contrast enhanced computed tomography (CT-scan) is a standard of care for the radiological diagnosis of hepatocellular carcinoma (HCC) in patients with cirrhosis. This technique, however, is not validated to exclude intrahepatic cholangiocarcinoma (ICC) which may develop in patients with cirrhosis, as well. METHODS: To assess the features of contrast CT-scan in the diagnosis of ICC, we reviewed all CT-scan films obtained in cirrhotic patients with a histologically documented ICC, taking in consideration the pattern and dynamics of the arterial, portal venous and delayed phases of contrast uptake. RESULTS: Thirty-two patients had 40 nodules of ICC (22 male; median age 62years; 13 hepatitis C) that were identified either during surveillance with abdominal ultrasound (21 patients, 66%) or incidentally (11 patients, 34%). ICC was either multifocal or ≥ 30 mm in 11 of the former and 10 of the latter group (52% vs. 91%, p<0.05). Two nodules (5%) escaped detection by CT-scan, while the remaining 38 showed a heterogeneous contrast enhancement pattern, being the arterial peripheral-rim enhancement present in 19 (50%) cases and a progressive homogeneous contrast uptake in 16 (42%) cases during the three vascular phases, with no relation to tumor size. Importantly, all nodules lacked the radiological hallmark of HCC, the only ICC nodule showing a homogeneous wash-in during the arterial phase followed by a wash-out in the delayed venous phase, however showing a homogeneous wash-in during the portal phase too. CONCLUSIONS: ICC in cirrhotic patients displays distinct vascular patterns at CT-scan that allow for differentiation from HCC.

Agreement between real-time elastography and delayed enhancement magnetic resonance enterography on quantifying bowel wall fibrosis in Crohn's disease.

BACKGROUND: the assessment of fibrosis in Crohn's disease (CD) bowel lesions helps to guide therapeutic decisions. Real-time elastography (RTE) and delayed-enhancement magnetic resonance enterography (DE-MRE) have demonstrated good accuracy in quantifying CD-related ileal fibrosis as compared with histological examination. To date no study has compared DE-MRE and RTE. AIMS: we aimed to evaluate the agreement between RTE and DE-MRE on quantifying CD-related ileal fibrosis. METHODS: consecutive patients with ileal or ileocolonic CD underwent RTE and DE-MRE. Ileal fibrosis was quantified by calculating the strain ratio (SR) at RTE and the 70s-7 min percentage of enhancement gain (%EG) of both mucosa and submucosa at DE-MRE. A SR ≥2 was applied to define severe fibrosis. Clinically relevant outcomes occurring at follow-up were recorded. RESULTS: 40 CD patients were enrolled. A significant linear correlation was observed between SR and submucosal %EG (r = 0.594, p < 0.001). Patients with severe fibrosis (SR ≥2) had significantly higher submucosal %EG values than patients with low/moderate fibrosis (median values 26.4% vs. 9.5%, p < 0.001). During a median 43.8-month follow-up relevant disease outcomes occurred more frequently in the severe-fibrosis group (75% vs. 36%, HR 5.4, 95% CI 1.2-24.6, p = 0.029). CONCLUSIONS: the study demonstrates an excellent agreement between RTE and DE-MRE in assessing ileal fibrosis in CD.

Diagnosis of hepatocellular carcinoma in cirrhosis by dynamic contrast imaging: the importance of tumor cell differentiation.

UNLABELLED: Dynamic contrast imaging techniques are considered the standard of care for the radiological diagnosis of hepatocellular carcinoma (HCC) in cirrhosis. However, the accuracy of radiological diagnosis depends largely on the degree of arterial hypervascularization, which increases with tumor size. Owing to the interplay and prognostic relevance of tumor vascularization and cell differentation, we asked ourselves whether tumor grade also affects the outcome of radiological diagnosis. Sixty-two HCCs (47 of which measured 1-2 cm) were consecutively detected in 59 patients with compensated cirrhosis under surveillance with ultrasound and confirmed by way of echo-guided biopsy and concurrent investigations with contrast-enhanced ultrasound (CE-US), computed tomography (CT), and gadolinium magnetic resonance imaging (MRI). Tumor cell differentiation was evaluated using Edmondson-Steiner criteria in liver cores of 0.9-5.0 cm (median 1.6 cm). Eighteen (29%) HCCs were grade I (1.5 cm), 28 (45%) were grade II (1.5 cm), 16 (26%) were grade III (1.8 cm), and none were grade IV. Contrast wash-in and wash-out were concurrently demonstrated in 21 (34%) tumors by way of CE-US, including three (16%) grade I and 18 (41%) grade II-III (P = 0.08); in 32 (52%) tumors by way of CT, including three (16%) grade I and 29 (66%) grade II-III (P = 0.0006); and 28 (47%) tumors by way of MRI, including three grade I (16%) and 25 (57%) grade II-III (P = 0.01). Among 1- to 2-cm tumors, the radiological diagnosis was achieved in two of 16 grade I and 17 of 31 grade II-III tumors (P = 0.006). CONCLUSION: Tumor grade, a relevant predictor of disease severity, influences the accuracy of dynamic contrast techniques in the diagnosis of HCC.

The diagnostic and economic impact of contrast imaging techniques in the diagnosis of small hepatocellular carcinoma in cirrhosis.

BACKGROUND: Contrast-enhanced ultrasound (CE-US), contrast CT scan and gadolinium dynamic MRI are recommended for the characterisation of liver nodules detected during surveillance of patients with cirrhosis with US. AIM: To assess the sensitivity, specificity, diagnostic accuracy and economic impact of all possible sequential combinations of contrast imaging techniques in patients with cirrhosis with 1-2 cm liver nodules undergoing US surveillance. PATIENTS/METHODS: 64 patients with 67 de novo liver nodules (55 with a size of 1-2 cm) were consecutively examined by CE-US, CT, MRI, and a fine-needle biopsy (FNB) as diagnostic standard. Undiagnosed nodules were re-biopsied; non-malignant nodules underwent enhanced imaging follow-up. The typical radiological feature of hepatocellular carcinoma (HCC) was arterial phase hypervascularisation followed by portal/venous phase washout. RESULTS: HCC was diagnosed in 44 (66%) nodules (2, <1 cm; 34, 1-2 cm; 8, >2 cm). The sensitivity of CE-US, CT and MRI for 1-2 cm HCC was 26, 44 and 44%, with 100% specificity, the typical vascular pattern of HCC being identified in 22 (65%) by a single technique versus 12 (35%) by at least two techniques carried out at the same time point (p=0.028). Compared with the cheapest dual examination (CE-US+CT), the cheapest single technique of stepwise imaging diagnosis of HCC was equally expensive (euro 26 440 vs euro 28 667), but led to a 23% reduction of FNB procedures (p=0.031). CONCLUSIONS: In patients with cirrhosis with a 1-2 cm nodule detected during surveillance, a single imaging technique showing a typical contrast pattern confidently permits the diagnosis of HCC, thereby reducing the need for FNB examinations.

A surrogate model for plaque modeling in carotids based on Robin conditions calibrated by cine MRI data.

We propose a surrogate model for the fluid-structure interaction (FSI) problem for the study of blood dynamics in carotid arteries in presence of plaque. This is based on the integration of a numerical model with subject-specific data and clinical imaging. We propose to model the plaque as part of the tissues surrounding the vessel wall through the application of an elastic support boundary condition. In order to characterize the plaque and other surrounding tissues, such as the close-by jugular vein, the elastic parameters of the boundary condition were spatially differentiated and their values were estimated by minimizing the discrepancies between computed vessel displacements and reference values obtained from CINE Magnetic Resonance Imaging data. We applied the model to three subjects with a degree of stenosis greater than 70%. We found that accounting for both plaque and jugular vein in the estimation of the elastic parameters increases the accuracy. In particular, in all patients, mismatches between computed and in vivo measured wall displacements were one to two orders of magnitude lower than the spatial resolution of the original MRI data. These results confirmed the validity of the proposed surrogate plaque model. We also compared fluid-dynamics results with those obtained in a fixed wall setting and in a full FSI model, used as gold standard, highlighting the better accordance of our results in comparison to the rigid ones.

Intestinal ischemic manifestations of SARS-CoV-2: Results from the ABDOCOVID multicentre study.

BACKGROUND: Intestinal ischemia has been described in case reports of patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease (coronavirus disease 19, COVID-19). AIM: To define the clinical and histological, characteristics, as well as the outcome of ischemic gastrointestinal manifestations of SARS-CoV-2 infection. METHODS: A structured retrospective collection was promoted among three tertiary referral centres during the first wave of the pandemic in northern Italy. Clinical, radiological, endoscopic and histological data of patients hospitalized for COVID-19 between March 1st and May 30th were reviewed. The diagnosis was established by consecutive analysis of all abdominal computed tomography (CT) scans performed. RESULTS: Among 2929 patients, 21 (0.7%) showed gastrointestinal ischemic manifestations either as presenting symptom or during hospitalization. Abdominal CT showed bowel distention in 6 patients while signs of colitis/enteritis in 12. Three patients presented thrombosis of main abdominal veins. Endoscopy, when feasible, confirmed the diagnosis (6 patients). Surgical resection was necessary in 4/21 patients. Histological tissue examination showed distinctive features of endothelial inflammation in the small bowel and colon. Median hospital stay was 9 d with a mortality rate of 39%. CONCLUSION: Gastrointestinal ischemia represents a rare manifestation of COVID-19. A high index of suspicion should lead to investigate this complication by CT scan, in the attempt to reduce its high mortality rate. Histology shows atypical feature of ischemia with important endotheliitis, probably linked to thrombotic microangiopathies.

Acquired acral lipodystrophy in a 6-year-old girl.

We report a case of partial lipodystrophy in a 6-year-old girl with normal lipid and glucose metabolism and no family history for similar disorders. The clinical presentation, the laboratory investigations and the natural history in our patient do not match the diagnostic criteria for any of the established lipodystrophy subsets.

Prediction of Long Term Restenosis Risk After Surgery in the Carotid Bifurcation by Hemodynamic and Geometric Analysis.

This study explored the potential of hemodynamic disturbances and geometric features to predict long-term carotid restenosis after carotid endarterectomy (CEA). Thirteen CEA for carotid diameter stenosis > 70% were performed with patch graft (PG) angioplasty in nine cases, and primary closure (PC) in four cases. MRI acquisitions within one month after CEA were used for hemodynamic and geometric characterization. Personalized computational hemodynamic simulations quantified the exposure to low and oscillatory wall shear stress (WSS). Geometry was characterized in terms of flare (the expansion at the bulb) and tortuosity. At 60 months after CEA, Doppler ultrasound (DUS) was applied for restenosis detection and intima-media thickness determination. Larger flares were associated to larger exposure to low WSS (Pearson R2 values up to 0.38, P < 0.05). The two cases characterized by the highest flare and the largest low WSS exposure developed restenosis > 50% at 60 months. Linear regressions revealed associations of DUS observations of thickening with flare variables (up to R2 = 0.84, P < 0.001), and the exposure to low (but not oscillatory) WSS (R2 = 0.58, P < 0.05). Our findings suggest that arteriotomy repair should avoid a large widening of the carotid bulb, which is linked to restenosis via the generation of flow disturbances. Hemodynamics and geometry-based analyses hold potential for (1) preoperative planning, guiding the PG vs. PC clinical decision, and (2) stratifying long-term restenosis risk after CEA.

Low-dose CT scan in stone detection for stone treatment follow-up: is there a relation between stone composition and radiation delivery? Study on a porcine-kidney model.

BACKGROUND: Non-contrast CT scan (NCCT) is becoming the standard imaging modality in urinary stone disease. Radiation dose remains an issue, especially for those patients who may need to undergo several CT scans for this indication during their lifetime. Low-dose and ultra-low-dose protocols exist, but there is limited data on the relationship between the minimum radiation dose capable of detecting stone fragments and stone composition. METHODS: Seven different kinds of human kidney stone were selected. Fragments of 1, 2, 4 and 7 mm were obtained for each stone. Four fragments of the same material were placed in a porcine kidney. A CT scan was then used to scan the kidney at decreasing dosages of 140, 70, 30, 15 and 7mAs. The scans were repeated for each type of stone. Images were reviewed by two radiologists independently with the intent of identifying the stone composition and providing information on its position, dimensions and Hounsfield units (HU). RESULTS: All types of stone were visible at all settings. Only the 1-mm uric-acid fragment was not detected by both radiologists at 7 and 15 mAs. Dose Length product (DLP) decreased with the reduction in mAs. In terms of HU a statistically significant difference was observed between calcium-based and non-calcium-based stones. Stone dimensions and HU were not affected by the reductions in mAs. CONCLUSIONS: Ultra-low-dose CT has a good detection rate for all kinds of stone, even when the fragment size is small. Only small uric acid fragments need higher energy settings in order to be detected. When the stone composition is known after surgery for urolithiasis, the most appropriate CT scan setting could be suggested by the urologist during their follow-up.