Background: The aim of the study was to evaluate the inter- and intrareader variability of the safety margin assessment after microwave ablation of liver tumors using post-procedure computed tomography (CT) images as well as to determine the sensitivity and specificity of identification remnant tumor tissue. Patients and methods: A retrospective analysis of 58 patients who underwent microwave ablation (MWA) of primary or secondary liver malignancies (46 hepatocellular carcinoma, 9 metastases of a colorectal cancer and 3 metastases of pancreatic cancer) between September 2017 and June 2019 was conducted. Three readers estimated the minimal safety margin in millimeters using side-by-side comparison of the 1-day pre-ablation CT and 1-day post-ablation CT and judged whether ablation was complete or incomplete. One reader estimated the safety margin again after 6 weeks. Magnetic resonance imaging (MRI) after 6 weeks was the gold standard. Results: The intraclass correlation coefficient (ICC) for estimation of the minimal safety margin of all three readers was 0.357 (95%-confidence interval 0.194–0.522). The ICC for repeated assessment (reader 1) was 0.774 (95%-confidence interval 0.645–0.860). Sensitivity and specificity of the detection of complete tumor ablation, defined as no remnant tumor tissue in 6 weeks follow-up MRI, were 93%/82%/82% and 33%/17%/83%, respectively. Conclusions: In clinical practice, the safety margin after liver tumor ablation is often assessed using side-by-side comparison of CT images. In the study, we were able to show, that this technique has a poor reliability (ICC 0.357). From our point of view, this proves the necessity of new technical procedures for the assessment of the safety distance.

Background: The aim of the study was to assess the primary efficacy of robot-assisted microwave ablation and compare it to manually guided microwave ablation for percutaneous ablation of liver malignancies. Patients and methods: We performed a retrospective single center evaluation of microwave ablations of 368 liver tumors in 192 patients (36 female, 156 male, mean age 63 years). One hundred and nineteen ablations were performed between 08/2011 and 03/2014 with manual guidance, whereas 249 ablations were performed between 04/2014 and 11/2018 using robotic guidance. A 6-week follow-up (ultrasound, computed tomography and magnetic resonance imaging) was performed on all patients. Results: The primary technique efficacy outcome of the group treated by robotic guidance was significantly higher than that of the manually guided group (88% vs . 76%; p = 0.013). Multiple logistic regression analysis indicated that a small tumor size (≤ 3 cm) and robotic guidance were significant favorable prognostic factors for complete ablation. Conclusions: In addition to a small tumor size, robotic navigation was a major positive prognostic factor for primary technique efficacy.

Early detection of local tumor progression (LTP) after irreversible electroporation (IRE) and microwave ablation (MWA) of hepatocellular carcinoma (HCC) remains challenging. The goal of this study was to identify cases with insufficient ablation and prevent HCC recurrencies by measuring iodine uptake using dual-energy computed tomography (DECT). In 54 HCC-patients, the volumetric iodine concentration (VIC) of the central and peripheral ablation area was evaluated by DECT within 24 h after IRE or MWA. Follow-up was performed with CT and/or MRI at 6 weeks, 3, 6, 9, and 12 months, respectively. In both groups, LTP was solely detected in the peripheral area (IRE: n = 4; MWA: n = 4) and LTP patients showed significantly higher VIC values in the peripheral zone than patients without LTP (IRE: * p = 0.0005; MWA: * p = 0.000). In IRE-LTP patients, no significant difference between the VIC values of non-ablated liver tissue and the peripheral zone was detected (p = 0.155). The peripheral zones of IRE patients without LTP (* p = 0.000) and MWA patients, irrespective of the presence of LTP (LTP: * p = 0.005; without LTP: * p = 0.000), showed significantly lower VIC values than non-ablated liver parenchyma. Higher BCLC tumor stages were indicative for LTP (* p = 0.008). The study suggests that elevated iodine uptake in the peripheral ablation zone could help identify LTP after IRE and MWA of HCC.

Background and Objectives: The standard diagnostic procedure for a patient with a suspected polytrauma injury is computed tomography (CT). In individual cases, however, extended acute imaging using magnetic resonance imaging (MRI) can provide valuable and therapy-relevant information. The aim of our cohort study was to find such cases and to describe their characteristics in order to be able to give possible recommendations for MRI application in acute trauma situations. Materials and Methods: In the study period from 2015–2019, an evaluation of the imaging performed on polytrauma patients was carried out. The specific diagnostic and therapeutic criteria of the MRI group were further defined. Results: In total, 580 patients with an ISS ≥16 (injury severity score) were included in the study. Of these 580 patients, 568 patients received a CT scan and 12 patients an MRI scan as part of the initial diagnostic. Altogether, 66.67% of the MRIs took place outside of regular service hours. The main findings for MRI indications were neurological abnormalities with a focus on myelon injuries. Further MRI examinations were performed to rule out vascular injuries. All in all, 58.3% of the MRIs performed resulted in modified therapeutic strategies afterward. Conclusions: MRI in the context of acute diagnostic of a severely injured patient will likely remain reserved for special indications in the future. However, maximum care hospitals with a high flow of severely injured patients should provide 24/7 MR imaging to ensure the best possible care, especially in neurological and blunt vascular injuries.

Introduction: Traumatic cervical artery dissections are associated with high mortality and morbidity in severely injured patients. After finding even higher incidences than reported before, we decided to incorporate a dedicated head-and-neck computed tomography angiogram (CT-A) in our imaging routine for patients who have been obviously severely injured or, according to trauma mechanism, are suspected to be severely injured. Materials and Methods: A total of 134 consecutive trauma patients with an ISS ≥ 16 admitted to our level I trauma center during an 18 month period were included. All underwent standardized whole-body CT in a 256-detector row scanner with a dedicated head-and-neck CT-A realized as single-bolus split-scan routine. Incidence, mortality, patient and trauma characteristics, and concomitant injuries were recorded and analyzed in patients with carotid artery dissection (CAD) and vertebral artery dissection (VAD). Results: Of the 134 patients included, 7 patients had at least one cervical artery dissection (CeAD; 5.2%; 95% CI 1.5–9.0%). Six patients (85.7%) had carotid artery dissections, with one patient having a CAD of both sides and one patient having a CAD and contralateral VAD combined. Two patients (28.6%) showed a VAD. Overall mortality was 14.3%, neurologic morbidity was 28.6%. None of the patients showed any attributable neurologic symptoms on admission. The new scanning protocol led to further 5 patients with suspected CeAD during the study period, all ruled out by additional magnetic resonance imaging with angiogram (MRI/MR-A). Conclusion: A lack of specific neurologic symptoms on admission urges the need for a dedicated imaging pathway for severely injured patients, reliable for the detection of cervical artery dissections. Although our modified CT protocol with mandatory dedicated CT-A led to false positives requiring additional magnetic resonance imaging, it likely helped reduce possible therapeutic delays.