BACKGROUND AND PURPOSE: The optimal treatment of unruptured middle cerebral aneurysms is still under debate. Although today almost any aneurysm can be treated endovascularly, there is a lack of data comparing endovascular and microsurgical repair of MCA aneurysms. The aim of our analysis is to provide data on the efficacy, clinical outcome, complications and re-treatment rates of endovascular treatment of this subtype of aneurysms. MATERIALS AND METHODS: Between May 2008 and July 2017, endovascular treatment of 1184 aneurysms in 827 patients was performed in our department. Twenty-four percent of these aneurysms were located at the MCA, and 150 unruptured MCA bifurcation aneurysms treated with coiling, stent-assisted-coiling, or endovascular flow diverter (WEB device) were identified for this retrospective data analysis. Ninety-six percent of all aneurysms, ruptured and unruptured, were treated by an endovascular approach, which yields a low selection bias for aneurysms suitable for endovascular treatment. Follow-up examinations were performed after 12 and 36 months and then every 1-3 years after embolization. Procedures were analyzed for periprocedural complications, outcome, and retreatment rate of the WEB (n ϭ 38) and coiling with (n ϭ 45) or without stent assistance (n ϭ 67). RESULTS: The procedure-associated good clinical outcome (mRS Ϲ 2) was 89.9%, and the mortality rate was 2.7%. Short-term follow-up good clinical outcome/mortality rates were 91.3%/0.7%. At discharge, 137 patients had an mRS of 0-2 (91.3%) and 13 had an mRS of 3-6 (8.7%). The retreatment rate was significantly higher in the WEB group (21.1%) compared with the coiling group with (5.9%) or without (2.2%) stent placement (P Ͻ .05). CONCLUSIONS: Regardless of the architecture of MCA bifurcation aneurysms, the endovascular treatment can be performed with low morbidity/mortality rates. The higher retreatment rate in the WEB group correlates with the learning curve in choosing the right device size.

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Purpose This study was conducted to evaluate the role of liver sonography in patients with coronavirus disease 2019 (COVID-19) and elevated liver enzymes. Materials and methods In this retrospective study, patients tested positive for SARS-CoV-2 in our emergency ward between January 01 and April 24, 2020 and elevated liver enzymes were included (Cohort 1). Additionally, the local radiology information system was screened for sonographies in COVID-19 patients at the intensive care unit in the same period (Cohort 2). Liver sonographies and histologic specimen were reviewed and suspicious findings recorded. Medical records were reviewed for clinical data. Ultrasound findings and clinical data were correlated with severity of liver enzyme elevation. Results Cohort 1: 126 patients were evaluated, of which 47 (37.3%) had elevated liver enzymes. Severity of liver enzyme elevation was associated with death (p<0.001). 8 patients (6.3%) had suspicious ultrasound findings, including signs of acute hepatitis (n = 5, e.g. thickening of gall bladder wall, hepatomegaly, decreased echogenicity of liver parenchyma) and vascular complications (n = 4). Cohort 2: 39 patients were evaluated, of which 14 are also included in Cohort 1. 19 patients (48.7%) had suspicious ultrasound findings, of which 13 patients had signs of acute hepatitis and 6 had vascular complications. Pathology was performed in 6 patients. Predominant findings were severe cholestasis and macrophage activation. Conclusion For most hospitalized COVID-19 patients, elevated liver enzymes cause little concern as they are only mild to moderate. However, in severely ill patients bedside sonography is a powerful tool to reveal different patterns of vascular, cholestatic or inflammatory complications in the liver, which are associated with high mortality. In addition, macrophage activation as histopathologic correlate for a hyperinflammatory syndrome seems to be a frequent complication in COVID-19.

Background Photon-counting computed tomography (PCCT) is a promising new technology with the potential to fundamentally change today’s workflows in the daily routine and to provide new quantitative imaging information to improve clinical decision-making and patient management. Method The content of this review is based on an unrestricted literature search on PubMed and Google Scholar using the search terms “Photon-Counting CT”, “Photon-Counting detector”, “spectral CT”, “Computed Tomography” as well as on the authors’ experience. Results The fundamental difference with respect to the currently established energy-integrating CT detectors is that PCCT allows counting of every single photon at the detector level. Based on the identified literature, PCCT phantom measurements and initial clinical studies have demonstrated that the new technology allows improved spatial resolution, reduced image noise, and new possibilities for advanced quantitative image postprocessing. Conclusion For clinical practice, the potential benefits include fewer beam hardening artifacts, radiation dose reduction, and the use of new contrast agents. In this review, we will discuss basic technical principles and potential clinical benefits and demonstrate first clinical use cases. Key Points:  Citation Format

To provide clinically relevant criteria for differentiation between the athlete’s heart and similar appearing hypertrophic (HCM), dilated (DCM), and arrhythmogenic right-ventricular cardiomyopathy (ARVC) in MRI. 40 top-level athletes were prospectively examined with cardiac MR (CMR) in two university centres and compared to retrospectively recruited patients diagnosed with HCM (n = 14), ARVC (n = 18), and DCM (n = 48). Analysed MR imaging parameters in the whole study cohort included morphology, functional parameters and late gadolinium enhancement (LGE). Mean left-ventricular enddiastolic volume index (LVEDVI) was high in athletes (105 ml/m2) but significantly lower compared to DCM (132 ml/m2; p = 0.001). Mean LV ejection fraction (EF) was 61% in athletes, below normal in 7 (18%) athletes vs. EF 29% in DCM, below normal in 46 (96%) patients (p < 0.0001). Mean RV-EF was 54% in athletes vs. 60% in HCM, 46% in ARVC, and 41% in DCM (p < 0.0001). Mean interventricular myocardial thickness was 10 mm in athletes vs. 12 mm in HCM (p = 0.0005), 9 mm in ARVC, and 9 mm in DCM. LGE was present in 1 (5%) athlete, 8 (57%) HCM, 10 (56%) ARVC, and 21 (44%) DCM patients (p < 0.0001). Healthy athletes’ hearts are characterized by both hypertrophy and dilation, low EF of both ventricles at rest, and increased interventricular septal thickness with a low prevalence of LGE. Differentiation of athlete’s heart from other non-ischemic cardiomyopathies in MRI can be challenging due to a significant overlap of characteristics also seen in HCM, ARVC, and DCM.

Objectives To evaluate computed tomography fractional flow reserve (FFRCT) values in distal parts of the coronaries in an asymptomatic cohort of marathon runners without any coronary stenosis for potentially false-positive values. Methods Ninety-eight asymptomatic male marathon runners (age 53 ± 7 years) were enrolled in a prospective monocentric study and underwent coronary computed tomography angiography (CCTA). CCTA data were analyzed for visual coronary artery stenosis. FFRCT was evaluated in 59 participants without coronary artery stenosis in proximal, mid, and distal coronary sections using an on-site software prototype. Results In participants without coronary artery stenosis, abnormal FFRCT values ≤ 0.8 in distal segments were found in 22 participants (37%); in 19 participants in the LAD; in 5 participants in the LCX; and in 4 participants in the RCA. Vessel diameters in participants with FFRCT values > 0.80 compared to ≤ 0.80 were 1.6 ± 0.3 mm versus 1.5 ± 0.3 mm for distal LAD (p = 0.025), 1.8 ± 0.3 mm versus 1.6 ± 0.5 mm for distal LCX (p = 0.183), and 2.0 ± 0.4 mm versus 1.5 ± 0.2 mm for distal RCA (p < 0.001). Conclusions Abnormal FFRCT values of ≤ 0.8 frequently occurred in distal coronary segments in subjects without any anatomical coronary artery stenosis. This effect is only to some degree explainable by small distal vessel diameters. Therefore, the validity of hemodynamic relevance evaluation using FFRCT in distal coronary artery segment stenosis is reduced. Key Points • Abnormal FFRCT values (≤ 0.8) occurred in over a third of the subjects in the distal LAD despite the absence of coronary artery stenosis.. • Therefore, the validity of hemodynamic relevance evaluation in distal coronary artery segment stenosis is reduced. • Decision-making based on abnormal FFRCT values in distal vessel sections should be performed with caution and only in combination with visual assessment of the grade of stenosis..

Our aim was to compare the image quality and patient dose of contrast-enhanced oncologic chest-CT of a first-generation photon-counting detector (PCD-CT) and a second-generation dual-source dual-energy CT (DSCT). For this reason, one hundred consecutive oncologic patients (63 male, 65 ± 11 years, BMI: 16–42 kg/m2) were prospectively enrolled and evaluated. Clinically indicated contrast-enhanced chest-CT were obtained with PCD-CT and compared to previously obtained chest-DSCT in the same individuals. The median time interval between the scans was three months. The same contrast media protocol was used for both scans. PCD-CT was performed in QuantumPlus mode (obtaining full spectral information) at 120 kVp. DSCT was performed using 100 kV for Tube A and 140 kV for Tube B. “T3D” PCD-CT images were evaluated, which emulate conventional 120 keV polychromatic images. For DSCT, the convolution algorithm was set at I31f with class 1 iterative reconstruction, whereas comparable Br40 kernel and iterative reconstruction strengths (Q1 and Q3) were applied for PCD-CT. Two radiologists assessed image quality using a five-point Likert scale and performed measurements of vessels and lung parenchyma for signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and in the case of pulmonary metastases tumor-to-lung parenchyma contrast ratio. PCD-CT CNRvessel was significantly higher than DSCT CNRvessel (all, p < 0.05). Readers rated image contrast of mediastinum, vessels, and lung parenchyma significantly higher in PCD-CT than DSCT images (p < 0.001). Q3 PCD-CT CNRlung_parenchyma was significantly higher than DSCT CNRlung_parenchyma and Q1 PCD-CT CNRlung_parenchyma (p < 0.01). The tumor-to-lung parenchyma contrast ratio was significantly higher on PCD-CT than DSCT images (0.08 ± 0.04 vs. 0.03 ± 0.02, p < 0.001). CTDI, DLP, SSDE mean values for PCD-CT and DSCT were 4.17 ± 1.29 mGy vs. 7.21 ± 0.49 mGy, 151.01 ± 48.56 mGy * cm vs. 288.64 ± 31.17 mGy * cm and 4.23 ± 0.97 vs. 7.48 ± 1.09, respectively. PCD-CT enables oncologic chest-CT with a significantly reduced dose while maintaining image quality similar to a second-generation DSCT for comparable protocol settings.

The aim of this paper is to evaluate the diagnostic image quality of spectral dual-source photon-counting detector coronary computed tomography angiography (PCD-CCTA) for coronary artery disease in a multicenter study. The image quality (IQ), assessability, contrast-to-noise ratio (CNR), Agatston score, and radiation exposure were measured. Stenoses were quantified and compared with invasive coronary angiography, if available. A total of 92 subjects (65% male, age 58 ± 14 years) were analyzed. The prevalence of significant coronary artery disease (CAD) (stenosis ≥ 50%) was 17% of all patients, the range of the Agatston score was 0–2965 (interquartile range (IQR) 0–135). The IQ was very good (one, IQR one–two), the CNR was very high (20 ± 10), and 5% of the segments were rated non-diagnostic. The IQ and assessability were higher in proximal coronary segments (p < 0.001). Agatston scores up to 600 did not significantly affect the assessability of the coronary segments (p = 0.3). Heart rate influenced assessability only at a high-pitch mode (p = 0.009). For the invasive coronary angiography (ICA) subgroup (n = nine), the diagnostic performance for CAD per segment was high (sensitivity 92%, specificity 96%), although the limited number of patients who underwent both diagnostic modalities limits the generalization of this finding at this stage. PCD-CCTA provides good image quality for low and moderate levels of coronary calcifications.