Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but potentially curable cause of pulmonary hypertension (PH). Currently PH is diagnosed by right heart catheterisation. Computed tomography (CT) is used for ruling out other causes and operative planning. This study aims to evaluate importance of different quantitative/qualitative imaging features and develop a supervised machine learning (ML) model to predict hemodynamic risk groups. 127 Patients with diagnosed CTEPH who received preoperative right heart catheterization and thoracic CTA examinations (39 ECG-gated; 88 non-ECG gated) were included. 19 qualitative/quantitative imaging features and 3 hemodynamic parameters [mean pulmonary artery pressure, right atrial pressure (RAP), pulmonary artery oxygen saturation (PA SaO2)] were gathered. Diameter-based CT features were measured in axial and adjusted multiplane reconstructions (MPR). Univariate analysis was performed for qualitative and quantitative features. A random forest algorithm was trained on imaging features to predict hemodynamic risk groups. Feature importance was calculated for all models. Qualitative and quantitative parameters showed no significant differences between ECG and non-ECG gated CTs. Depending on reconstruction plane, five quantitative features were significantly different, but mean absolute difference between parameters (MPR vs. axial) was 0.3 mm with no difference in correlation with hemodynamic parameters. Univariate analysis showed moderate to strong correlation for multiple imaging features with hemodynamic parameters. The model achieved an AUC score of 0.82 for the mPAP based risk stratification and 0.74 for the PA SaO2 risk stratification. Contrast agent retention in hepatic vein, mosaic attenuation pattern and the ratio right atrium/left ventricle were the most important features among other parameters. Quantitative and qualitative imaging features of reconstructions correlate with hemodynamic parameters in preoperative CTEPH patients—regardless of MPR adaption. Machine learning based analysis of preoperative imaging features can be used for non-invasive risk stratification. Qualitative features seem to be more important than previously anticipated.

Background:The incidence of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears in children and adolescents has increased over the past decade, with increasing numbers of ACL and PCL reconstructions in this patient population. Purpose:To evaluate the size and morphology of both the ACL and the PCL by magnetic resonance imaging (MRI) in different pediatric age groups. Study Design:Cross-sectional study; Level of evidence, 3. Methods:MRI examinations of 127 knees (67 female, 60 male; aged 0-18 years) were analyzed retrospectively. The cohort was split into 6 age subgroups, 1 subgroup for every 3 years (minimum 8 patients per subgroup). The following parameters were measured by 2 independent raters at 2 different time points: ACL length, anteroposterior and mediolateral ACL width, sagittal and coronal ACL inclination, inclination of the intercondylar notch, bicondylar width, notch width, coronal ACL and PCL width, PCL length, and sagittal width of the lateral femoral condyle. The following indices, areas, and volumes were calculated: sagittal width of the lateral femoral condyle/PCL length, ACL area and volume, notch width index, ACL width/notch width, PCL width/notch width, ACL width/bicondylar width, and PCL width/bicondylar width. A correlation analysis was performed for patient age, height, weight, and body mass index (BMI). Results:ACL length was between 18 and 37 mm, and ACL width was between 4 and 6 mm. PCL length ranged between 27 and 43 mm, while PCL width was between 7 and 9 mm. Growth of the cruciate ligaments was the most pronounced between the ages of 4 and 12 years. Correlations with size and weight were strong, while BMI correlated slightly with the measurements. Measurements in female patients were slightly larger than in their male counterparts between the ages of 0 and 6 years, while male patients tended to have larger values starting from ages 7 to 9 years. These values were significantly larger in male patients from the ages of 16 to 18 years (P < .05). Conclusion:This study provides normative data on the morphology of pediatric anatomic features in the knee as a basis for age-appropriate and individualized surgical care of ACL and PCL injuries in children and adolescents.

Zielsetzung Im Statement der Fleischner Gesellschaft zur pulmonalarteriellen Hypertonie (PAH) ergeben sich trotz bekannter Korrelationen von CT-Parametern zur pulmonalen Hämodynamik Hürden: 1. Unklarheit der Relevanz einzelner CT-Parameter, 2. Insuffizienz des oft prädiktiv verwendeten Tr. pulmonalis Durchmessers, 3. Unzulänglichkeit CT-abgeleiteter Prädiktionsmodelle. Ziel der Studie war es alle gängigen CT-Parameter an einer Kohorte von Patienten mit chronisch thrombembolischer PAH (CTEPH) in Zusammenschau mit dem Rechtsherzkatheter auf ihre Relevanz hin zu evaluieren. Zusätzlich wurden erstmalig KI-Algorithmen zur Prädiktion eingesetzt.

Introduction: Acute pulmonary embolism (PE) is a leading cardiovascular cause of death, resembling a common indication for emergency computed tomography (CT). Nonetheless, in clinical routine most CTs performed for suspicion of PE excluded the suspected diagnosis. As patients with low to intermediate risk for PE are triaged according to the d-dimer, its relatively low specifity and widespread elevation among elderly might be an underlying issue. Aim of this study was to find potential predictors based on initial emergency blood tests in patients with elevated d-dimers and suspected PE to further increase pre-test probability. Methods: In this retrospective study all patients at the local university hospital's emergency room from 2009 to 2019 with suspected PE, emergency blood testing and CT were included. Cluster analysis was performed to separate groups with distinct laboratory parameter profiles and PE frequencies were compared. Machine learning algorithms were trained on the groups to predict individual PE probability based on emergency laboratory parameters. Results: Overall, PE frequency among the 2045 analyzed patients was 41%. Three clusters with significant differences (p < 0.05) in PE frequency were identified: C1 showed a PE frequency of 43%, C2 40% and C3 33%. Laboratory parameter profiles (e.g. creatinine) differed significantly between clusters (p < 0.0001). Both logistic regression and support-vector machines were able to predict clusters with an accuracy of over 90%. Discussion: Initial blood parameters seem to enable further differentiation of patients with suspected PE and elevated d-dimers to raise pre-test probability of PE. Machine-learning-based prediction models might help to further narrow down CT indications in the future.

An amendment to this paper has been published and can be accessed via the original article.

Zielsetzung Der Ausschluss einer Lungenarterienembolie (LAE) mittels Computertomographie (CT) gehört zu den häufigsten Notfallindikationen der Radiologie. Das D-Dimer ist aufgrund seines lediglich hohen negativen prädiktiven Wertes sowie der geringen Spezifität im Falle einer Erhöhung nicht sinnvoll, um den Verdacht auf eine LAE zu erhärten. Aus diesem Grund fällt ein Großteil der Untersuchungen mit Fragestellung nach LAE negativ aus. Ziel dieser Arbeit war es, auf Basis des Eingangslabors mithilfe maschineller Lernalgorithmen ein Modell zur Vorhersage der LAE-Wahrscheinlichkeit bei Patienten mit positivem D-Dimer zu entwickeln.

The study described here systematically analyzed how specific artifacts in contrast-enhanced ultrasound (CEUS) can affect the detection of endoleaks during follow-up after endovascular aortic repair (EVAR). Patients undergoing EVAR of atherosclerotic or mycotic abdominal aortic aneurysms using various standard and branched stent-graft material for visceral and iliac preservation were enrolled over 5 y and followed up with computed tomography angiography (CTA) and CEUS simultaneously. CEUS artifacts were frequently identified after EVAR procedures (59% of examinations) and were caused mainly by contrast agent, different prosthesis or embolization material and postinterventional changes in the aneurysm sac. This article describes how to identify important artifacts and how to avoid false-negative or false-positive interpretations of endoleaks. Despite artifacts, CEUS had higher sensitivity for endoleak detection after EVAR than CTA. CEUS was superior to CTA in the identification of late endoleaks type II and in follow-up examinations after embolization procedures, where beam-hardening artifacts limited CTA.

Background: The best surgical treatment option for symptomatic moderate- to high-grade articular-sided partial-thickness rotator cuff tears (PTRCTs) is still controversial. Purpose/Hypothesis: The purpose of this study was to evaluate patient-reported and clinical outcomes and tendon integrity after arthroscopic debridement or repair for PTRCTs at a minimum of 2 years postoperatively. We hypothesized that the overall outcomes would be positive, showing pain relief, good shoulder function, and high tendon integrity. Study Design: Cohort study; Level of evidence, 3. Methods: We evaluated 30 patients (16 men, 14 women; mean age, 51 years) who underwent arthroscopic treatment for symptomatic PTRCTs (Ellman grades 2 and 3). Debridement was performed in 15 patients, and arthroscopic tendon repair was performed in the remaining 15 patients. Patients completed the Constant score; American Shoulder and Elbow Surgeons (ASES) shoulder score; Western Ontario Rotator Cuff Index; Simple Shoulder Test; and visual analog scale (VAS) for pain, function, and satisfaction. In addition, patients were examined clinically (range of motion, impingement tests, rotator cuff tests, and tests for the long head of the biceps tendon), and morphologic assessment of rotator cuff integrity was performed using direct magnetic resonance arthrography and was classified according to Sugaya. Results: The mean follow-up period was 55 months. The patient-reported outcome measures showed high patient satisfaction, reduction in persistent pain, and good shoulder function. Linear regression analysis showed that the debridement group had significantly better results on the Constant (bias-corrected and accelerated [BCa] 95% CI, 4.20-26.30), ASES (BCa 95% CI, 5.24-39.26), and VAS (pain: BCa 95% CI, 0.13-3.62; function: BCa 95% CI, 1.04-4.84; satisfaction: BCa 95% CI, 0.14-6.28) scores than did the repair group. At follow-up, there was no significant difference between the groups in clinical testing results. Good supraspinatus tendon integrity was seen in most patients: Sugaya classification grade 1 in 13 patients, grade 2 in 11 patients, and grade 3 in 6 patients. Conclusion: Midterm results after arthroscopic debridement and repair for PTRCTs showed high patient satisfaction, good shoulder function, and high tendon integrity for both procedures. Patients who underwent arthroscopic debridement had higher Constant, ASES, and VAS scores compared with patients who underwent tendon repair.

Objectives: We assessed left ventricular (LV) function and central hemodynamic effects in patients with a heart rate (HR) at rest of >70 beats per minute (bpm) and chronic coronary syndrome (CCS) after long-term treatment with ivabradine compared to placebo by cardiac magnetic resonance (CMR) imaging. Methods and results: In a randomized, double-blinded, prospective cross-over design, 23 patients (18 male, 5 female) were treated with ivabradine (7.5 mg bid) or placebo for 6 months. CMR imaging was performed at baseline and after 6 and 12 months to determine LV functional parameters. Mean resting HR on treatment with ivabradine was 58 +/- 8.2 bpm and 70.2 +/- 8.3 bpm during placebo (p < 0.0001).There was no difference in systolic LV ejection fraction (ivabradine 57.4 +/- 11.2% vs placebo 53.0 +/- 10.9%, p = 0.18), indexed end-diastolic (EDVi) or end-systolic volumes (ESVi). Indexed stroke volume (SVi) (ml/m(2)) remained unchanged after treatment with ivabradine. Volume time curve parameters reflecting systolic LV function (peak ejection rate and time) were unaffected by ivabradine, while both peak filling rate (PFR) and PFR/EDV were significantly increased. Mean aortic velocity (cm/s) was significantly reduced during treatment with ivabradine (ivabradine 6.7 +/- 2.7 vs placebo 9.0 +/- 3.4, p = 0.01). Aortic flow parameters were correlated to parameters of vascular stiffness. The strongest correlation was revealed for mean aortic velocity with aortic distensibility (AD) (r = -0.86 [-0.90 to -0.85], p < 0.0001). Conclusion: Long-term reduction of HR with ivabradine in patients with CCS improved diastolic function and reduced mean aortic flow velocity. (C) 2021 The Authors. Published by Elsevier B.V.

Background: This prospective study evaluated the learning curve of inexperienced medical students in successfully establishing an ultrasound guided vessel access. Methods: Medical students (n=11) with no experience in ultrasound imaging were asked to perform an ultrasound- guided vessel access simulated by a gelatin based phantom model. Success rates and time of procedures were measured. Afterwards, every student underwent peer-teaching with both theoretical information given and practical training skills applied. Then, every student had to perform the very same procedure again and results were compared in a prior- to post-teaching scenario with paired t-test. Results: After theoretical and practical teaching lessons all students were able to successfully establish an ultrasound-guided vascular access. Prior to teaching sessions, only 4 out of 11 students managed to successfully perform the procedure. Success rate rose from 36.4% to 100%. Mean number of attempts were 2.5 +- 1.3 before, and 1.2 +- 0.4 after teaching (p < 0.05). Overall time to successful guide wire placement improved from 291+-8 seconds to 151+-37 seconds (p<0.05). Conclusions: In a gelatin based phantom model for ultrasound-guided vascular access medical students demonstrate significantly improved practical puncture skills and thus a steep learning curve.

Abstract Objectives We sought to assess central hemodynamic effects in 23 patients (18 male, 5 female) with a resting heart rate (HR) of ≥70 beats per minute (bpm) and chronic coronary syndrome after long-term ivabradine therapy (6 months) by cardiac magnetic resonance (CMR). Methods and results In a cross-over design, all patients were treated with ivabradine (Iva, 7.5 mg bid) and placebo for 6 months each. CMR was performed three times (at baseline, after 6 and 12 months) to determine left ventricular (LV) function parameters, including end-diastolic and end-systolic volumes (EDVi, ESVi), stroke volume (SVi) and ejection fraction (EF) as well as volume-time curve (VTC) parameters, including peak ejection rate (PER), peak ejection time (PET), peak filling rate (PFR), peak filling time from ES (PFT), peak ejection rate normalized to EDV (PER/EDV) and peak filling rate normalized to EDV (PFR/EDV) for global LV function (systolic and diastolic) assessment. Flow measurements of the ascending aorta were performed with phase-contrast velocity imaging. Treatment with Iva led to a HR reduction of 11.4 bpm (Iva 58.8±8.2 bpm vs placebo 70.2±8.3 bpm, p<0.0001).There was no difference in LVEF (%) (Iva 57.4±11.2 vs placebo 53.0±10.9, p=0.18), EDVi or ESVi. SVi (ml/m2) remained comparatively unchanged after long-term treatment with Iva (Iva 40.6±9.6 vs placebo 35.7±8.8, p=0.08). VTC parameters reflecting systolic LV function (PER, PET) were unaffected by Iva, while both PFR and PFR/EDV were significantly increased (PFR/EDV (s-1) Iva 2.4±0.4 vs placebo 2.1±0.4, p=0.03). There was a trend to longer PFT during treatment with Iva, though not reaching statistical significance. Medium and maximum aortic flow were not affected by treatment with Iva, while mean velocity (cm/s) was significantly reduced (Iva 6.7±2.7 vs placebo 9.0±3.4, p=0.01). Aortic flow parameters were correlated to aortic distensibility (AD), as surrogate parameter for arterial stiffness. AD was significantly correlated to both aortic flow and flow velocity, whereby mean velocity showed the strongest correlation to AD (r=0.74 [0.61 to 0.83], p<0.0001). Conclusion Systolic LV function was unaffected by treatment with Iva, while the filling during diastole was significantly improved. While medium and maximum aortic flow were not affected by Iva, mean velocity was significantly reduced. Aortic distensibility as surrogate parameter for arterial stiffness was significantly correlated to aortic mean velocity. This study confirms the underlying physiological principle of the If-current inhibitor Ivabradine. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): This work was supported by the Deutsche Herzstiftung (German Heart Foundation) (F/14/11 to F.C.) and the Deutsche Forschungsgemeinschaft (DFG KFO 196 to U.L., S.H.S and M.B. and SFB TTR 219, S-01 to M.B.). The Saarland University Medical Center has received an unrestricted grant from Servier (France).

PURPOSE:Quantified computed tomography (qCT) is known for correlations with airflow obstruction and fibrotic changes of the lung. However, as qCT studies often focus on diseased and elderly subjects, current literature lacks physiological qCT values during body development. We evaluated chest CT examinations of a healthy cohort, reaching from infancy to adulthood, to determine physiological qCT values and changes during body development. METHOD:Dose-optimized chest CT examinations performed over the last 3 years using a dual-source CT were retrospectively analysed. Exclusion criteria were age >30 years and any known or newly diagnosed lung pathology. Lung volume, mean lung density, full-width-at-half-maximum and low attenuated volume (LAV) were semi-automated quantified in 151 patients. qCT values between different age groups as well as unenhanced (Group 1) and contrast-enhanced (Group 2) protocols were compared. Models for projection of age-dependant changes in qCT values were fitted. RESULTS:Significant differences in qCT parameters were found between the age groups from 0 to 15 years (p < 0.05). All parameters except LAV merge into a plateau level above this age as shown by polynomial models (r2 between 0.85 and 0.67). In group 2, this plateau phase is shifted back around five years. Except for the volume, significant differences in all qCT values were found between group 1 and 2 (p < 0.01). CONCLUSION:qCT parameters underly a specific age-dependant dynamic. Except for LAV, qCT parameters reach a plateau around adolescence. Contrast-enhanced protocols seem to shift this plateau backwards.

Background Internal herniation of small intestine in the lesser pelvis alongside iliac vasculature is a rare occurrence. Skeletonization of iliac vessels during pelvic lymph node dissection (LND), as part of surgical staging or treatment of patients with uterine, ovarian or urogenital cancer, is a strict prerequisite for orifice formation. Case presentation A 68-year-old woman presented at the emergency department with complaints of constipation for the last 3 days and acute-onset abdominal pain, nausea and vomiting since few hours. She had a history of laparoscopic hysterectomy, bilateral salpingo-oophorectomy and para-aortic and pelvic LND 7 years ago. A distended abdomen with diffuse tenderness on palpation was noted. A CT scan demonstrated bowel obstruction secondary to an incarcerated hernia underneath an elongated right external iliac artery. During an emergency exploratory laparotomy, the incarcerated bowel was reduced and the hernial orifice closed with a running suture. The patient had an uneventful postoperative period and was discharged on the fifth postoperative day. Discussion This rare internal hernia can manifest with non-specific symptoms of small bowel obstruction at any given point after index surgery, sometimes even after several years free of complaints. Contrast-enhanced computed tomography is the method of choice for fast and reliable diagnosis and helps in planning the necessary emergency laparotomy. Conclusion This life-threatening complication adds to the current controversy of pelvic and para-aortic lymphadenectomy in patients with endometrial cancer. Primary closure of peritoneal defects should be considered to potentially prevent internal hernias, especially when elongated iliac vessels are present.

AIM:To evaluate prospectively the safety of contrast medium injection through standard peripheral intravenous cannulas at standard injection sites during clinical routine using iomeprol 400, a contrast agent with high viscosity. MATERIALS AND METHODS:Three thousand, five hundred and fourteen clinical CT examinations undertaken at Saarland University Medical Center were included in this prospective observational trial. The size and site of the cannula as well as the contrast medium injection rate and volume were assessed for each patient. In addition, the ability to aspirate blood though the cannula and the occurrence of complications, such as extravasation or abortion of injection by the automated injector, were recorded. RESULTS:The overall complication rate was 30/3,514 (0.85%). With 22 G cannulas, the complication rate was 8/541 (1.48%) applying flow rates of 1-3.5 ml/s (mean 2.1 ml/s). With 20 G cannulas, complications occurred in 21/2,601 cases (0.81%) with flow rates of 1.5-5 ml/s (mean 3 ml/s). The complication rate using 18 G cannulas was 1/377 (0.26%) for flow rates of 2-6 ml/s (mean 3.5 ml/s). No relationship between the site and size of the cannula to the occurrence of complications was found. The inability to aspirate blood correlated with the development of extravasation. CONCLUSIONS:The injection of contrast agent using standard peripheral venous cannulas is a safe and reliable procedure yielding diagnostic image contrast, even when using highly viscous contrast agents such as iomeprol 400; an aspiration test should be performed before each injection.

Zielsetzung Korrelationen zwischen quantifizierter Computertomografie (qCT) und obstruktiven bzw. restriktiven Lungenerkrankungen sind wissenschaftlich belegt. Bisherige Arbeiten fokussierten sich jedoch auf erkrankte bzw. ältere Individuen. Der aktuellen Literatur mangelt es an Vergleichsparametern lungengesunder Personen sowie Informationen über die Veränderungen der Parameter im Laufe der körperlichen Entwicklung. Ziel war es somit, qCT-Parameter einer lungengesunden Kohorte vom Kleinkind- bis zum Erwachsenenalter zu bestimmen.

Die NOMI (nicht okklusive mesenteriale Ischämie) hat eine hohe Letalität. Diese geht auf die fehlende Berücksichtigung der Erkrankung in der Differenzialdiagnose und die Invasivität zurück, die erforderlich ist, um die Diagnose zu sichern und unverzüglich eine Therapie einzuleiten. Der Beitrag schildert die geeigneten diagnostischen und therapeutischen Maßnahmen und stellt den Homburg-NOMI-Score zur Bestimmung des Schweregrads der Erkrankung vor.

A correction to this paper has been published: https://doi.org/10.1007/s12262-021-02805-2

INTRODUCTION:Epidemiological and clinical studies have shown a relevant association between heart rate and cardiovascular mortality. Experimental studies identified vascular effects of heart rate reduction with the If channel inhibitor ivabradine. Therefore, the effects of heart rate reduction on endothelial function and indices of arterial stiffness were examined in patients with stable coronary artery disease in a prospective, placebo-controlled clinical crossover study. METHODS AND RESULTS:Twenty-three patients (18 men and 5 women) with a resting heart rate (HR) of at least 70 beats per minute (bpm) and stable coronary artery disease were enrolled in this study. In a cross-over design, all patients were treated with ivabradine (Iva, 7.5 mg b.i.d.) and placebo for 6 months each. Iva reduced heart rate by 11.4 bpm (Iva 58.8 ± 8.2 bpm vs. placebo 70.2 ± 8.3 bpm, P < 0.0001). Augmentation index (AIx75), carotid-femoral pulse wave velocity (cfPWV) and central aortic blood pressure were measured using applanation tonometry (SphygmoCor). HRR by Iva increased AIx75 by 12.4% (Iva 24.3 ± 10.5% vs. placebo 21.3 ± 10.1%, P < 0.05) and reduced cfPWV by 14.1% (Iva 6.3 ± 1.7 m/s vs. placebo 7.3 ± 1.4 m/s, P < 0.01). Iva increased mean central blood pressure by 7.8% (Iva 107.5 ± 15.4 mmHg vs. placebo 99.1 ± 12.2 mmHg, P < 0.001). Endothelial function was determined measuring the flow-mediated vasodilation (FMD) of the brachial artery. HRR by Iva increased FMD by 18.5% (Iva 7.3 ± 2.2% vs. placebo 6.0 ± 2.0%, P < 0.001). Aortic distensibility was characterized by MRI. HRR by Iva increased aortic distensibility by 33.3% (Iva 0.003 ± 0.001/mmHg vs. placebo 0.002 ± 0.010/mmHg, P < 0.01) and circumferential cyclic strain by 37.1% (Iva 0.062 ± 0.027 vs. placebo 0.039 ± 0.018, P < 0.0001). CONCLUSION:Heart rate reduction with Iva increased endothelium-dependent vasodilation and reduced arterial stiffness in patients with stable CAD. These findings corroborate and expand the results collected in experimental studies and indicate the importance of heart rate as a determinant of vascular function.

To assess the change of body mass index (BMI), muscle mass, visceral and subcutaneous fat in patients with metastatic breast cancer. In this retrospective chart analysis, patients with metastatic breast cancer as initial diagnosis between 2012 and 2016 were analyzed. Patients had received either chemotherapy (CTH) or endocrine therapy (ETH) according to the German S3 Guideline. BMI was calculated from the patients’ weight and height. Change of muscle mass, visceral and subcutaneous fat was determined by comparing the surface area of these tissues on transverse CT images at the level of the third lumbar vertebrae (L3) at baseline and during treatment. A total of 45 patients were included in the study, 29 on CTH and 16 on ETH. BMI, visceral and subcutaneous fat remained stable over time for both treatment groups. When taking both treatment groups together, muscle mass decreased significantly by 5.0 ± 2.5 cm2 per year (p < 0.05). In patients with metastatic breast cancer, a slight reduction of muscle mass was observed, independent of therapy regimes.