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Additive manufacturing (AM) is one of the processes with the most potential for producing components used in internal combustion engines and features high efficiency due to the possibility of building very complex shapes. Several drawbacks of parts produced using AM are still unresolved, like poor surface quality, the presence of internal defects and anisotropic mechanical behaviour, which all contribute to decreasing the fatigue strength compared with the material produced using conventional processes. The effect of building direction on both the macroscopic mechanical behaviour and the crack propagation mechanism of Ni‐base superalloy Inconel718 produced using AM was investigated under the combined effect of low cycle fatigue (LCF) and high temperature. The different crack growth mechanisms investigated using compact tension (CT) specimens, tested at high temperature, showed a significant difference between the two building directions. The LCF fatigue experiments also showed a significant difference in the ε‐N curves from the two directions together with a high level of scatter due to the dispersion of the defect size at the fracture origin. The dimensions of the defects (as measured using the area parameter) were analysed by means of extreme value statistics and showed a significant difference between the two orientations investigated. The aim of this work is to propose a simplified approach (based on ΔJeff concepts) to estimate the fatigue life of a component produced using AM that takes into account the material variability due to the combined effect of mechanical anisotropic behaviour and the presence of defects at high‐temperature conditions. [ABSTRACT FROM AUTHOR]

Background: Several ablation confirmation software methods for minimum ablative margin assessment have recently been developed to improve local outcomes for patients undergoing thermal ablation of colorectal liver metastases. Previous assessments were limited to single institutions mostly at the place of development. The aim of this study was to validate the previously identified 5 mm minimum ablative margin (A0) using autosegmentation and biomechanical deformable image registration in a multi-institutional setting., Methods: This was a multicentre, retrospective study including patients with colorectal liver metastases undergoing CT- or ultrasound-guided microwave or radiofrequency ablation during 2009-2022, reporting 3-year local disease progression (residual unablated tumour or local tumour progression) rates by minimum ablative margin across all institutions and identifying an intraprocedural contrast-enhanced CT-based minimum ablative margin associated with a 3-year local disease progression rate of less than 1%., Results: A total of 400 ablated colorectal liver metastases (median diameter of 1.5 cm) in 243 patients (145 men; median age of 62 [interquartile range 54-70] years) were evaluated, with a median follow-up of 26 (interquartile range 17-40) months. A total of 119 (48.9%) patients with 186 (46.5%) colorectal liver metastases were from international institutions B, C, and D that were not involved in the software development. Three-year local disease progression rates for 0 mm, >0 and <5 mm, and 5 mm or larger minimum ablative margins were 79%, 15%, and 0% respectively for institution A (where the software was developed) and 34%, 19%, and 2% respectively for institutions B, C, and D combined. Local disease progression risk decreased to less than 1% with an intraprocedurally confirmed minimum ablative margin greater than 4.6 mm., Conclusion: A minimum ablative margin of 5 mm or larger demonstrates optimal local oncological outcomes. It is proposed that an intraprocedural minimum ablative margin of 5 mm or larger, confirmed using biomechanical deformable image registration, serves as the A0 for colorectal liver metastasis thermal ablation., (© The Author(s) 2024. Published by Oxford University Press on behalf of BJS Foundation Ltd. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

This ESR Essentials article intends to provide detailed, step-by-step, information on the role of imaging in the diagnosis, procedural management, and follow-up of patients with fluid collections. Evidence-based medicine recommendations for the positioning of percutaneous drainages and/or for diagnostic/therapeutic aspiration of fluid collections are provided. Although medical history, clinical symptoms, physical examination, and laboratory tests can raise suspicions regarding a collection, an imaging assessment is usually necessary for the diagnosis. Radiologists can easily identify fluid collections that are clinically suspected by using a wide range of imaging modalities, such as ultrasound, CT, MRI, and cone-beam CT. Consequently, these imaging methods (either alone or combined), can be used to aspirate the collection or for the placement of a drainage catheter. The choice of imaging technique to be used is influenced by the location of the collection, operator preference, size, and content of the collection. In addition, it is of utmost importance to underline the role of the interventional radiologist in the management and follow-up of patients with percutaneous drains, in collaboration with surgeons, clinicians, and diagnostic radiologists. KEY POINTS: Indications for percutaneous imaging-guided drainage are supported by clinical findings, laboratory tests, and pre-procedural imaging. Deciding between aspiration or drain insertion should follow patient assessment and fluid collection characterization. The interventional radiologist should be part of the entire patient care process including follow-up., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: Evaluating the pathological response and the survival outcomes of combined thermal ablation (TA) and transarterial chemoembolization (TACE) as a bridge or downstaging for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) > 3 cm., Materials and Methods: A retrospective review encompassed 36 consecutive patients who underwent combined TA-TACE as bridging or downstaging before LT. Primary objectives included necrosis of the target lesion at explant pathology, post-LT overall survival (OS) and post-LT recurrence-free survival (RFS). For OS and RFS, a comparison with 170 patients subjected to TA alone for nodules <3 cm in size was also made., Results: Out of the 36 patients, 63.9% underwent TA-TACE as bridging, while 36.1% required downstaging. The average node size was 4.25 cm. All cases were discussed in a multidisciplinary tumor board to assess the best treatment for each patient. Half received radiofrequency (RF), and the other half underwent microwave (MW). All nodes underwent drug-eluting beads (DEB) TACE with epirubicin. The mean necrosis percentage was 65.9% in the RF+TACE group and 83.3% in the MW+TACE group (p-value = 0.099). OS was 100% at 1 year, 100% at 3 years and 94.7% at 5 years. RFS was 97.2% at 1 year, 94.4% at 3 years and 90% at 5 years. Despite the different sizes of the lesions, OS and RFS did not show significant differences with the cohort of patients subjected to TA alone., Conclusions: The study highlights the effectiveness of combined TA-TACE for HCC>3 cm, particularly for bridging and downstaging to LT, achieving OS and RFS rates significantly exceeding 80% at 1, 3 and 5 years., (© 2024. The Author(s).)

Objectives: To evaluate the impact of the ultrasound-guided popliteal sciatic nerve block (PSNB) for pain management during endovascular treatment of chronic limb-threatening ischemia (CLTI)., Material and Methods: From November 2020 to January 2022, 111 CLTI patients that underwent endovascular procedures were prospectively enrolled in this prospective single-arm interventional study. Ultrasound-guided PSNB was used for procedural pain control. Pain intensity was evaluated throughout the procedure (baseline, 10 min after the block, pain peak, and at the end of the procedure) with the visual analog scale (VAS)., Results: Forty-six patients underwent above-the-knee revascularization (ATK), 20/111 below-the-knee (BTK) revascularization, 20/111 to both ATK and BTK revascularization. In 25 cases, no endovascular option was feasible at diagnostic angiography. The PSNB was effective in 96% of patients, with no need for further pain management with a statistically significant reduction (p < 0.0001) in the mean value of the VAS from 7.86 ± 1.81 (pre-procedural) to 2.04 ± 2.20 after 10 min from the block and up to 0.74 ± 1.43 at the end of the procedure (mean time 43 min). Only 1 complication related to the popliteal sciatic nerve block was registered (a temporary foot drop, completely resolved within 48 h). The time necessary to perform the block ranged between 4 and 10 min., Conclusion: Ultrasound-guided PSNB is a feasible and effective method to manage patients with rest pain and increase comfort and compliance during endovascular procedures., Clinical Relevance Statement: An ultrasound-guided popliteal sciatic nerve block is a safe, feasible, and effective technique to manage pain during endovascular treatment of chronic limb-threatening ischemia, especially in frail patients with multiple comorbidities who are poor candidates for deep sedoanalgesia or general anesthesia., Key Points: Endovascular treatment of CTLI may require long revascularization sessions in patients with high levels of pain at rest, which could be exacerbated during the revascularization procedure. The PSNB is routinely used for anesthesia and analgesia during foot and ankle surgery, but the experience with lower limb revascularization procedures is very limited and not included in any international guideline. Ultrasound-guided PSNB is a feasible and effective regional anesthesia technique to relieve procedural and resting pain. Because of its safety and availability, every interventional radiologist should know how to perform this type of loco-regional anesthesia., (© 2023. The Author(s), under exclusive licence to European Society of Radiology.)

Background: The minimally invasive management of sub-centimetric and often sub-solid lung lesions is quite challenging for thoracic surgeons. As a matter of fact, thoracoscopic wedge resection can often require conversion to thoracotomy when pulmonary lesions cannot be visually identified. Hybrid operating rooms (ORs) can serve as a helpful tool in a multidisciplinary setting, providing real-time lesion imaging and targeting, allowing preoperative or intraoperative percutaneous placement of different lesions targeting techniques to help locate non-palpable lung nodules during video-assisted thoracic surgery. The aim of the study is to assess whether the lung nodule marking using methylene blue, indocyanine green, and gold seeds - the "triple-marking technique" - in the hybrid OR is effective in helping locate non-visible or palpable nodules., Methods: We conducted a retrospective study on 19 patients with non-palpable lung lesions requiring VATS wedge resection and underwent lesional targeting in the hybrid operating room with different marking systems, including gold seeds placement, methylene blue, or indocyanine green. Lesions were considered non-palpable due to sizing, radiological subsolid aspect, or location and then identified using intraoperative CT scans, also allowing to elaborate needle trajectory. The intraoperative diagnosis was obtained in all of the patients guiding the type of surgery performed., Results: The radio-opaque gold seed marker was used in all of the patients except for two cases that developed intraprocedural pneumothoraces with no major consequences. In these patients, the nodule marking using dyes was still performed and successful in allowing to locate the lesion. Methylene blue and indocyanine green were always used in combination during the dye-targeting phase. Methylene blue appeared to be non-visible in two patients. The indocyanine green was correctly visualized in every patient. We observed the gold seed dislocation in two patients. We were able to identify the lung lesion in all the patients correctly. No conversion was needed. No allergic reactions were observed due to dye administration, and no prophylaxis was performed prior to lesional marking. The lung lesions were visually identified in 100% of the patients thanks to at least one marking technique., Conclusions: Our experience confirms that the hybrid operating room can represent a suitable tool in helping locate hard-to-find lung lesions in planned VATS resections. Using different techniques, a multiple marking approach seems advisable to maximize the lung lesions detecting rate by direct vision, therefore reducing the VATS conversion rate.

Indoor event locations are particularly affected by the SARS-CoV-2 pandemic. At large venues, only incomplete risk assessments exist, whereby no suitable measures can be derived. In this study, a physical and data-driven statistical model for a comprehensive infection risk assessment has been developed. At venues displacement ventilation concepts are often implemented. Here simplified theoretical assumptions fail for the prediction of relevant airflows for airborne transmission processes. Thus, with locally resolving trace gas measurements infection risks are computed more detailed. Coupled with epidemiological data such as incidences, vaccination rates, test sensitivities, and audience characteristics such as masks and age distribution, predictions of new infections (mean), situational R-values (mean), and individual risks on- and off-seat can be achieved for the first time. Using the Stuttgart State Opera as an example, the functioning of the model and its plausibility are tested and a sensitivity analysis is performed with regard to masks and tests. Besides a reference scenario on 2022-11-29, a maximum safety scenario with an obligation of FFP2 masks and rapid antigen tests as well as a minimum safety scenario without masks and tests are investigated. For these scenarios the new infections (mean) are 10.6, 0.25 and 13.0, respectively. The situational R-values (mean) - number of new infections caused by a single infectious person in a certain situation - are 2.75, 0.32 and 3.39, respectively. Besides these results a clustered consideration divided by age, masks and whether infections occur on-seat or off-seat are presented. In conclusion this provides an instrument that can enable policymakers and operators to take appropriate measures to control pandemics despite ongoing mass gathering events., (© 2023. The Author(s).)

Background: The case describes a successful endovascular thrombectomy using the ClotTriever System for an acute subclavian thrombosis in venous thoracic outlet syndrome. To the best of our knowledge, this is the first case report on use of Inari ClotTriever for acute upper extremity deep venous thrombosis due to venous thoracic outlet syndrome. The rapid technical and clinical success of our intervention may be an interesting cue for interventional radiologist colleagues., Case Presentation: Upper extremity deep vein thrombosis in the setting of venous thoracic outlet syndrome generally occurs in young adults after excessive arm activity and can sometimes be managed with anticoagulation. In this case, a 29-year-old male diagnosed with acute effort-induced thrombosis of the left subclavian vein and persistent symptoms following low-molecular-weight heparin therapy underwent mechanical thrombectomy. Successful thrombectomy was completed with > 90% thrombus burden reduction and no complication. The patient experienced immediate symptom relief and vein patency was confirmed via imaging 3 months post procedure., Conclusions: Mechanical thrombectomy is a promising treatment technique for thrombosis associated with venous thoracic outlet syndrome., (© 2023. The Author(s).)

Background: Percutaneous thermal ablation is a curative-intent locoregional therapy (LRT) for selected patients with unresectable colorectal liver metastasis (CLM). Several factors have been identified that contribute to local tumour control after ablation. However, factors contributing to disease progression outside the ablation zone after ablation are poorly understood., Methods: In this retrospective study, using next-generation sequencing, we identified genetic biomarkers associated with different patterns of progression following thermal ablation of CLM., Results: A total of 191 ablation naïve patients between January 2011 and March 2020 were included in the analysis, and 101 had genomic profiling available. Alterations in the TGFβ pathway were associated with increased risk of development of new intrahepatic tumours (hazard ratio [HR], 2.75, 95% confidence interval [95% CI] 1.39-5.45, P = 0.004); and alterations in the Wnt pathway were associated with increased probability of receiving salvage LRT for any intrahepatic progression (HR, 5.8, 95% CI 1.94-19.5, P = 0.003)., Conclusions: Our findings indicate that genomic alterations in cancer-related signalling pathways can predict different progression patterns and the likelihood of receiving salvage LRT following percutaneous thermal ablation of CLM., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

The purpose of this study was to evaluate the efficacy of unenhanced cone-beam computed tomography (CBCT) performed at the end of drug-eluting bead transarterial chemoembolization (DEB-TACE) in predicting HCC nodules’ early radiologic response to treatment, assessed using mRECIST criteria with a 30−60 day four-phase contrast-enhanced CT follow-up. Fifty-nine patients (81 lesions) subjected to DEB-TACE as exclusive treatment for HCC lesions (naive/relapse) between February 2020 and October 2021 were prospectively enrolled. In a post-interventional unenhanced CBCT procedure, two experienced radiologists evaluated for each lesion the overall intensity of the contrast media deposit, the homogeneity of the enhancement, and the presence of smooth and complete margins. The univariate analysis found that lesions with complete response (CR+) had a significantly higher incidence of clear and complete margins than CR− lesions (76.9% vs. 17.2%, p = 0.003) and a higher intensity score (67.3% vs. 27.6%, p = 0.0009). A Dmax <30 mm was significantly more common among CR+ than CR− lesions (92.3% vs. 69%, p = 0.01). These features were confirmed as significant predictors for CR+ by multivariate binary logistic regression. The homogeneity of the enhancement did not affect the DEB-TACE outcome. Post-interventional unenhanced CBCT is effective in predicting early radiological response to DEB-TACE, since the presence of an intense contrast media deposit with clear and complete margins in treated HCC lesions is associated with CR.

This study introduces a principle that unifies two experimental methods for evaluating airborne indoor virus-transmissions adapted to several ventilation measures. A first-time comparison of mechanical/natural ventilation and air purification with regard to infection risks is enabled. Effortful computational fluid dynamics demand detailed boundary conditions for accurate calculations of indoor airflows, which are often unknown. Hence, a suitable, simple and generalized experimental set up for identifying the spatial and temporal infection risk for different ventilation measures is more qualified even with unknown boundary conditions. A trace gas method is suitable for mechanical and natural ventilation with outdoor air exchange. For an accurate assessment of air purifiers based on filtration, a surrogate particle method is appropriate. The release of a controlled rate of either trace gas or particles simulates an infectious person releasing virus material. Surrounding substance concentration measurements identify the neighborhood exposure. One key aspect of the study is to prove that the requirement of concordant results of both methods is fulfilled. This is the only way to ensure that the comparison of different ventilation measures described above is reliable. Two examples (a two-person office and a classroom) show how practical both methods are and how the principle is applicable for different types and sizes of rooms.

Objectives: Oligometastatic colorectal cancer benefits of locoregional treatments but data concerning microwave ablation (MWA) are limited and interactions with systemic therapy are still debated. The aim of this study is to evaluate safety and effectiveness of Thermosphere™ MWA (T-MWA) of colorectal liver metastases (CLM) and factors affecting local tumor progression-free survival (LTPFS)., Methods: In this multi-institutional retrospective study (January 2015-September 2019), patients who underwent T-MWA for CLM were enrolled. Complications according to SIR classification were collected, primary efficacy and LTP were calculated. Analyzed variables included CLM size at diagnosis and at ablation, CLM number, ablation margins, intra-segment progression, chemotherapy before ablation (CBA), variations in size (ΔS DIA-ABL ), and velocity of size variation (V DIA-ABL ) between CLM diagnosis and ablation. Uni/multivariate analyses were performed using mixed effects Cox model to account for the hierarchical structure of data, patient/lesions., Results: One hundred thirty-two patients with 213 CLM were evaluated. Complications were reported in 6/150 procedures (4%); no biliary complications occurred. Primary efficacy was achieved in 204/213 CLM (95.7%). LTP occurred in 58/204 CLM (28.4%). Six-, twelve-, and eighteen-month LTPFS were 88.2%, 75.8%, and 69.9%, respectively. At multivariate analysis, CLM size at ablation (p = 0.00045), CLM number (p = 0.046), ablation margin < 5 mm (p = 0.0035), and intra-segment progression (p < 0.0001) were statistically significant for LTPFS. ΔS DIA-ABL (p = 0.63) and V DIA-ABL (p = 0.38) did not affect LTPFS. Ablation margins in the chemo-naïve group were larger than those in the CBA group (p < 0.0001)., Conclusion: T-MWA is a safe and effective technology with adequate LTPFS rates. Intra-segment progression is significantly linked to LTPFS. CBA does not affect LTPFS. Anticipating ablation before chemotherapy may take the advantages of adequate tumor size with correct ablation margin planning., Key Points: • Thermosphere™-Microwave ablation is a safe and effective treatment for colorectal liver metastases with no registered biliary complications in more than 200 ablations. • Metastases size at time of ablation, intra-segment progression, and minimal ablation margin < 5 mm were found statistically significant for local tumor progression-free survival. • Chemotherapy before ablation modifies kinetics growth of the lesions but deteriorates ablation margins and does not significantly impact local tumor progression-free survival., (© 2022. The Author(s).)

Purpose: To present our experience and provide a literature review dissertation about the use of a suture-mediated percutaneous closure device (Perclose Proglide -PP- Abbott Vascular Inc., Santa Clara, CA, USA) to achieve hemostasis for unintended subclavian arterial catheterization during central venous line placement., Materials & Methods: Since October 2020, we have successfully treated four consecutive patients with a central venous catheter (8 to 12 French) in the subclavian artery. In each patient, we released a PP, monitoring its efficacy by performing a subclavian angiogram and placing, as a rescue strategy, an 8 mm balloon catheter near the entry point of the misplaced catheter. Primary outcome is technical and clinical success. Technical success is defined as absence of bleeding signs at completion angiography, while clinical success is a composite endpoint defined as absence of hematoma, hemoglobin loss at 12 and 24 h, and absence of procedure-related reintervention (due to vessel stenosis, pseudoaneurysm or distal embolization)., Results: Technical success was obtained in 75% of cases. In one patient a mild extravasation was resolved after 3 min of balloon catheter inflation. No early complications were observed for all patients., Conclusions: PP showed a safe and effective therapeutic option in case of unintentional arterial cannulation. It can be considered as first-line strategy, as it does not preclude the possibility to use other endovascular approaches in case of vascular closure device failure., (© 2022. The Author(s).)

The aim of our study is the development of an automatic tool for the prioritization of COVID-19 diagnostic workflow in the emergency department by analyzing chest X-rays (CXRs). The Convolutional Neural Network (CNN)-based method we propose has been tested retrospectively on a single-center set of 542 CXRs evaluated by experienced radiologists. The SARS-CoV-2 positive dataset (n = 234) consists of CXRs collected between March and April 2020, with the COVID-19 infection being confirmed by an RT-PCR test within 24 h. The SARS-CoV-2 negative dataset (n = 308) includes CXRs from 2019, therefore prior to the pandemic. For each image, the CNN computes COVID-19 risk indicators, identifying COVID-19 cases and prioritizing the urgent ones. After installing the software into the hospital RIS, a preliminary comparison between local daily COVID-19 cases and predicted risk indicators for 2918 CXRs in the same period was performed. Significant improvements were obtained for both prioritization and identification using the proposed method. Mean Average Precision (MAP) increased (p < 1.21 × 10−21 from 43.79% with random sorting to 71.75% with our method. CNN sensitivity was 78.23%, higher than radiologists’ 61.1%; specificity was 64.20%. In the real-life setting, this method had a correlation of 0.873. The proposed CNN-based system effectively prioritizes CXRs according to COVID-19 risk in an experimental setting; preliminary real-life results revealed high concordance with local pandemic incidence.

Mortality risk in COVID-19 patients is determined by several factors. The aim of our study was to adopt an integrated approach based on clinical, laboratory and chest x-ray (CXR) findings collected at the patient's admission to Emergency Room (ER) to identify prognostic factors. Retrospective study on 346 consecutive patients admitted to the ER of two North-Western Italy hospitals between March 9 and April 10, 2020 with clinical suspicion of COVID-19 confirmed by reverse transcriptase-polymerase reaction chain test (RT-PCR), CXR performed within 24 h (analyzed with two different scores) and recorded prognosis. Clinical and laboratory data were collected. Statistical analysis on the features of 83 in-hospital dead vs 263 recovered patients was performed with univariate (uBLR), multivariate binary logistic regression (mBLR) and ROC curve analysis. uBLR identified significant differences for several variables, most of them intertwined by multiple correlations. mBLR recognized as significant independent predictors for in-hospital mortality age > 75 years, C-reactive protein (CRP) > 60 mg/L, PaO 2 /FiO 2 ratio (P/F) < 250 and CXR "Brixia score" > 7. Among the patients with at least two predictors, the in-hospital mortality rate was 58% against 6% for others [p < 0.0001; RR = 7.6 (4.4-13)]. Patients over 75 years had three other predictors in 35% cases against 10% for others [p < 0.0001, RR = 3.5 (1.9-6.4)]. The greatest risk of death from COVID-19 was age above 75 years, worsened by elevated CRP and CXR score and reduced P/F. Prompt determination of these data at admission to the emergency department could improve COVID-19 pretreatment risk stratification., (© 2021. The Author(s).)

Predicting response to treatment plays a key role to assist radiologists in hepato-cellular carcinoma (HCC) therapy planning. The most widely used treatment for unresectable HCC is the trans-arterial chemoembolization (TACE). A complete radiological response after the first TACE is a reliable predictor of treatment favourable outcome. However, visual inspection of contrast-enhanced CT scans is time-consuming, error prone and too operator-dependent. Thus, in this paper we propose TwinLiverNet: a deep neural network that is able to predict TACE treatment outcome through learning visual cue from CT scans. TwinLiverNet, specifically, integrates 3D convolutions and capsule networks and is designed to process simultaneously late arterial and delayed phases from contrast-enhanced CTs. Experimental results carried out on a dataset consisting of 126 HCC lesions show that TwinLiverNet reaches an average accuracy of 82% in predicting complete response to TACE treatment. Furthermore, combining multiple CT phases (specifically, late arterial and delayed ones) yields a performance increase of over 12 percent points. Finally, the introduction of capsule layers into the model avoids the model to overfit, while enhancing accuracy.Clinical relevance- TwinLiverNet supports radiologists in visual inspection of CT scans to assess TACE treatment outcome, while reducing inter-operator variability.

In the last years, the widespread use of the prostate-specific antigen (PSA) blood examination to triage patients who will enter the diagnostic/therapeutic path for prostate cancer (PCa) has almost halved PCa-specific mortality. As a counterpart, millions of men with clinically insignificant cancer not destined to cause death are treated, with no beneficial impact on overall survival. Therefore, there is a compelling need to develop tools that can help in stratifying patients according to their risk, to support physicians in the selection of the most appropriate treatment option for each individual patient. The aim of this study was to develop and validate on multivendor data a fully automated computer-aided diagnosis (CAD) system to detect and characterize PCas according to their aggressiveness. We propose a CAD system based on artificial intelligence algorithms that a) registers all images coming from different MRI sequences, b) provides candidates suspicious to be tumor, and c) provides an aggressiveness score of each candidate based on the results of a support vector machine classifier fed with radiomics features. The dataset was composed of 131 patients (149 tumors) from two different institutions that were divided in a training set, a narrow validation set, and an external validation set. The algorithm reached an area under the receiver operating characteristic (ROC) curve in distinguishing between low and high aggressive tumors of 0.96 and 0.81 on the training and validation sets, respectively. Moreover, when the output of the classifier was divided into three classes of risk, i.e., indolent, indeterminate, and aggressive, our method did not classify any aggressive tumor as indolent, meaning that, according to our score, all aggressive tumors would undergo treatment or further investigations. Our CAD performance is superior to that of previous studies and overcomes some of their limitations, such as the need to perform manual segmentation of the tumor or the fact that analysis is limited to single-center datasets. The results of this study are promising and could pave the way to a prediction tool for personalized decision making in patients harboring PCa., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Giannini, Mazzetti, Defeudis, Stranieri, Calandri, Bollito, Bosco, Porpiglia, Manfredi, De Pascale, Veltri, Russo and Regge.)

Background: Bile leak (BL) after hepato-pancreato-biliary (HPB) surgery is associated with significant morbidity and mortality. Aim of this study was to evaluate effectiveness and safety of percutaneous transhepatic approach (PTA) to drainage BL after HPB surgery., Methods: Between 2006 and 2018, consecutive patients who were referred to interventional radiology units of three tertiary referral hospitals were retrospectively identified. Technical success and clinical success were analyzed and evaluated according to surgery type, BL-site and grade, catheter size and biochemical variables. Complications of PTA were reported., Results: One-hundred-eighty-five patients underwent PTA for BL. Technical success was 100%. Clinical success was 78% with a median (range) resolution time of 21 (5-221) days. Increased clinical success was associated with patients who underwent hepaticresection (86%,p = 0,168) or cholecystectomy (86%,p = 0,112) while low success rate was associated to liver-transplantation (56%,p < 0,001). BL-site,grade, catheter size and AST/ALT levels were not associated with clinical success. ALT/AST high levels were correlated to short time resolution (17 vs 25 days, p = 0,037 and 16 vs 25 day, p = 0,011, respectively) Complications of PTA were documented in 21 (11%) patients., Conclusion: This study based on a large cohort of patients demonstrated that PTA is a valid and safe approach in BL treatment after HPB surgery., (Copyright © 2021 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.)

Objectives: To investigate the predictive value of four-phase contrast-enhanced CT (CECT) for early complete response (CR) to drug-eluting-bead transarterial chemoembolization (DEB-TACE), with a particular focus on the quantitatively assessed wash-in and wash-out., Methods: A retrospective analysis of preprocedural CECTs was performed for 129 HCC nodules consecutively subjected to DEB-TACE as first-line therapy. Lesion size, location, and margins were recorded. For the quantitative analysis, the following parameters were computed: contrast enhancement ratio (CER) and lesion-to-liver contrast ratio (LLC) as estimates of wash-in; absolute and relative wash-out (WO abs and WO rel ) and delayed percentage attenuation ratio (DPAR) as estimates of wash-out. The early radiological response of each lesion was assessed by the mRECIST criteria and dichotomized in CR versus others (partial response, stable disease, and progressive disease)., Results: All quantitatively assessed wash-out variables had significantly higher rates for CR lesions (WO abs p = 0.01, WO rel p = 0.01, and DPAR p = 0.00002). However, only DPAR demonstrated an acceptable discriminating ability, quantified by AUC = 0.80 (95% CI0.73-0.88). In particular, nodules with DPAR ≥ 120 showed an odds ratio of 3.3(1.5-7.2) for CR (p = 0.0026). When accompanied by smooth lesion margins, DPAR ≥ 120 lesions showed a 78% CR rate at first follow-up imaging. No significative association with CR was found for quantitative wash-in estimates (CER and LLC)., Conclusions: Based on preprocedural CECT, the quantitative assessment of HCC wash-out is useful in predicting early CR after DEB-TACE. Among the different formulas for wash-out quantification, DPAR has the best discriminating ability. When associated, DPAR ≥ 120 and smooth lesion margins are related to relatively high CR rates., Key Points: • A high wash-out rate, quantitatively assessed during preprocedural four-phase contrast-enhanced CT (CECT), is a favorable predictor for early radiological complete response of HCC to drug-eluting-bead chemoembolization (DEB-TACE). • The arterial phase of CECT shows great dispersion of attenuation values among different lesions, even when a standardized protocol is used, limiting its usefulness for quantitative analyses. • Among the different formulas used to quantify the wash-out rate (absolute wash-out, relative wash-out, and delayed percentage attenuation ratio), the latter (DPAR), based only on the delayed phase, is the most predictive (AUC = 0.80), showing a significant association with complete response for values above 120., (© 2021. The Author(s).)

Background: Liver metastases (LMs) from thyroid cancer (TC) are relatively uncommon in clinical practice and their management is challenging. Interventional radiology loco-regional treatments (LRTs), including radiofrequency ablation (RFA) and trans-arterial chemoembolization (TACE), have been successfully employed to treat LMs from various types of cancer., Methods: We analyzed the role of LRTs in the management of unresectable LMs from differentiated and medullary TCs performed at our institution from 2015 to 2020. A review of the available English literature regarding this topic was also performed., Results: Six hepatic LRTs were performed in 4 TC patients with LMs, in 2 cases after the start of treatment with a tyrosine kinase inhibitor (TKI). A partial response was obtained in 2 patients; the diameter of the largest targeted lesion was 18 mm in both of them. The remaining procedures were performed on larger lesions and a stable disease was achieved in all but one case. Acute LRT-related complications were transient and mild. In literature, the largest studies were focused on TACE in LMs from MTC, showing good tolerance and remarkable disease control, especially in case of limited liver tumour involvement., Conclusion: LRTs for LMs represent a valuable option for the treatment of metastatic TC in case of isolated hepatic progression or for symptoms relief, also after the start of TKI treatment as part of a multimodal approach. The best disease control is obtained when hepatic metastatic burden is limited. These procedures are generally well tolerated; however, a cautious multidisciplinary selection of the candidates is mandatory., (© 2021. The Author(s).)

Purpose: Aim of this study was to identify preprocedural parameters, which may predict the application of a complex IVC filter retrieval technique and estimate the procedural outcome by applying two dedicated score systems., Materials and Methods: In this retrospective multicenter analysis, data concerning patient, filter and procedure characteristics were retrieved from January 2018 to March 2020. Patients were evaluated according to the retrieval technique (standard vs. complex) and the procedural outcome (success vs. failure). Significant differences among these groups were evaluated, and two score systems were developed to predict the application of a complex retrieval technique and the procedural outcome., Results: One hundred and sixteen IVC filters were retrieved in 116 patients. In 98 subjects, the filter was retrieved with a standard procedure (Standard group, 84.5% vs. Complex group, 15.5%), while in 106 patients the procedure was successful (Success group, 91.4% vs. Failure group, 8.6%). Statistically significant differences were noted in terms of embedded filter hook, filter apex tilt, angle between filter axis and IVC, caval wall penetration, dwelling time and procedural time. Two score 0-5 points to predict the need for a complex retrieval technique and the procedural outcome were developed, with a prognostic accuracy of 88.8% and 91.4%, respectively., Conclusion: Significant differences were appreciable analyzing the sample data comparing both the retrieval technique applied and the procedural outcome. Two predictive scores were developed to assess the need for applying a complex retrieval technique and to estimate the procedural outcome.

Newer biologic drugs and immunomodulatory agents, as well as more tolerated and effective radiation therapy schemes, have reduced treatment toxicity in oncology patients. However, although imaging assessment of tumor response is adapting to atypical responses like tumor flare, expected changes and complications of chemo/radiotherapy are still routinely encountered in post-treatment imaging examinations. Radiologists must be aware of old and newer therapeutic options and related side effects or complications to avoid a misinterpretation of imaging findings. Further, advancements in oncology research have increased life expectancy of patients as well as the frequency of long-term therapy-related side effects that once could not be observed. This pictorial will help radiologists tasked to detect therapy-related complications and to differentiate expected changes of normal tissues from tumor relapse.