On-site CT-derived cFFR in patients with suspected coronary artery disease: Feasibility on a 128-row CT scanner in everyday clinical practice.

PURPOSE: Technical feasibility of CT-based calculation of fractional flow reserve (cFFR) using a 128-row computed tomography scanner in an everyday routine setting. Post-processing and everyday practicability should be analyzed on the scanner on-site in connection with clinical parameters. MATERIALS AND METHODS: This single-center retrospective analysis included 230 patients (74 female; mean age 63.8 years) with CCTA within 21 months between 01/2018 and 09/2019 without non-pathological examinations. cFFR values were obtained using a deep learning-based non-commercial research prototype (cFFR Version3.5.0; Siemens Healthineers GmbH, Erlangen). cFFR values were evaluated at two points: at the maximum point of the stenosis and 1.0 cm distal to the stenosis. Comparison with invasive coronary angiography in 57/230 patients (24.7 %) was performed. CT parameters and quality were evaluated. Further subgroup classification concerning criteria of technical postprocessing was performed: no changes necessary, minor corrections necessary, major corrections necessary, and no evaluation was possible. The required time from starting the software to the final result was evaluated. RESULTS: A total of 116/448 (25.9 %) mild, 223/448 (49.8 %) moderate, and 109/448 (24.3 %) obstructive stenoses was found. The mean cFFR at the maximum point of the stenosis was 0.92 ±â€Š0.09 and significantly higher than the cFRR value of 0.89 ±â€Š0.13 distal to the stenosis (p < 0.001*). The mean degree of stenosis was 44.02 ±â€Š26.99 % (range: 1-99 %) with an area of 5.39 ±â€Š3.30 mm2. In a total of 45 patients (19.1 %), a relevant reduction in cFFR below 0.80 was determined. Overall, in 57/230 patients (24.8 %), catheter angiography was performed. No significant difference in the degree of maximal stenosis (CAD-RADS 0-2/3/4) was detected between the classification of CCTA and ICA (p = 0.171). The mean post-processing time varied significantly with 8.34 ±â€Š4.66 min. in single-vessel CAD vs. 12.91 ±â€Š3.92 min. in two-vessel CAD vs. 21.80 ± 5.94 min. in three-vessel CAD (each p < 0.001). CONCLUSION: Noninvasive onsite quantification of cFFR is feasible with minimal observer interaction in a routine real-world setting on a 128-row scanner. Deep learning-based algorithms allow a robust and semi-automatic on-site determination of cFFR based on data from standard CT scanners. KEY POINTS: · Non-invasive on-site quantification of cFFR is feasible with minimal observer interaction.. · Deep-learning based algorithms allow robust and semi-automatic on-site determination of cFFR.. · The mean follow-up time varied significantly with the extent of vascular CAD..

Comparison of Relaxometry Between Ulnar Nerve and Posterior Tibial Nerve After Cisatracurium Administration Using Electromyography.

Background: Electromyography can be used for quantitative neuromuscular monitoring during general anesthesia, mostly using the stimulation train-of-four (TOF) pattern. Relaxometry measures the muscular response of the adductor pollicis muscle to electrical stimulation of the ulnar nerve, which is routinely used in clinical practices for monitoring the neuromuscular block. However, when it is not always possible to be used for all patients, the posterior tibial nerve is a suitable alternative. Objectives: Using electromyography, we compared the neuromuscular block between the ulnar and the posterior tibial nerves. Methods: In this study, the participants were 110 patients who met inclusion criteria and submitted their written consent. Following the administration of cisatracurium intravenously, the patients had relaxometry performed simultaneously on the ulnar and the posterior tibial nerves using electromyography. Results: Eighty-seven patients were included in the final analysis. The onset time was 296 ± 99 s at the ulnar nerve and 346 ± 146 s at the tibial nerve, with a mean difference of -50 s and a standard deviation of 164 s. The 95% limits of agreement ranged from -372 s to 272 s. The relaxation time was 105 ± 26 min at the ulnar nerve and 87 ± 25 min at the tibial nerve, with a mean difference of 18 min and a standard deviation of 20 min. Conclusions: Using electromyography, no statistically significant difference was noticed between the ulnar and the posterior tibial nerve during the neuromuscular block. The onset time and the relaxation time assessed with an electromyogram to compare the stimulation of the ulnar and posterior tibial nerves showed large limits of agreement.

Structured Reporting in Cross-Sectional Imaging of the Heart: Reporting Templates for CMR Imaging of Ischemia and Myocardial Viability and for Cardiac CT Imaging of Coronary Heart Disease and TAVI Planning. / Strukturierte Befundung in der Schnittbilddiagnostik des Herzens: Befundvorlagen für die Herz-MRT bezüglich Ischämie- und Vitalitätsdiagnostik sowie für die Herz-CT bezüglich Koronardiagnostik und Planung vor TAVI.

BACKGROUND: Structured reporting allows a high grade of standardization and thus a safe and unequivocal report communication. In the past years, the radiological societies have started several initiatives to base radiological reports on structured reporting rather than free text reporting. METHODS: Upon invitation of the working group for Cardiovascular Imaging of the German Society of Radiology, in 2018 an interdisciplinary group of Radiologists, Cardiologists, Pediatric Cardiologists and Cardiothoracic surgeons -all experts on the field of cardiovascular MR and CT imaging- met for interdisciplinary consensus meetings at the University Hospital Cologne. The aim of these meetings was to develop and consent templates for structured reporting in cardiac MR and CT of various cardiovascular diseases. RESULTS: Two templates for structured reporting of CMR in ischemia imaging and vitality imaging and two templates for structured reporting of CT imaging for planning Transcatheter Aortic Valve Implantation (TAVI; pre-TAVI-CT) and coronary CT were discussed, consented and transferred to a HTML 5/IHR MRRT compatible format. The templates were made available for free use on the website www.befundung.drg.de. CONCLUSION: This paper suggests consented templates in German language for the structured reporting of cross-sectional CMR imaging of ischemia and vitality as well as reporting of CT imaging pre-TAVI and coronary CT. The implementation of these templates is aimed at providing a constant level of high reporting quality and increasing the efficiency of report generation as well as a clinically based communication of imaging results. KEY POINTS: · Structured reporting offers a constant level of high reporting quality and increases the efficiency of report generation as well as a clinically based communication of imaging results.. · For the first time templates in German language for the structured reporting of CMR imaging of ischemia and vitality and CT imaging pre-TAVI and coronary CT are reported.. · These templates will be made available on the website www.befundung.drg.de and can be commented via strukturierte-befundung@drg.de.. ZITIERWEISE: · Soschynski M, Bunck AC, Beer M et al. Structured Reporting in Cross-Sectional Imaging of the Heart: Reporting Templates for CMR Imaging of Ischemia and Myocardial Viability and for Cardiac CT Imaging of Coronary Heart Disease and TAVI Planning. Fortschr Röntgenstr 2023; 195: 293 - 296.

The TransEurope FootRace Project: longitudinal data acquisition in a cluster randomized mobile MRI observational cohort study on 44 endurance runners at a 64-stage 4,486 km transcontinental ultramarathon.

BACKGROUND: The TransEurope FootRace 2009 (TEFR09) was one of the longest transcontinental ultramarathons with an extreme endurance physical load of running nearly 4,500 km in 64 days. The aim of this study was to assess the wide spectrum of adaptive responses in humans regarding the different tissues, organs and functional systems being exposed to such chronic physical endurance load with limited time for regeneration and resulting negative energy balance. A detailed description of the TEFR project and its implemented measuring methods in relation to the hypotheses are presented. METHODS: The most important research tool was a 1.5 Tesla magnetic resonance imaging (MRI) scanner mounted on a mobile unit following the ultra runners from stage to stage each day. Forty-four study volunteers (67% of the participants) were cluster randomized into two groups for MRI measurements (22 subjects each) according to the project protocol with its different research modules: musculoskeletal system, brain and pain perception, cardiovascular system, body composition, and oxidative stress and inflammation. Complementary to the diverse daily mobile MR-measurements on different topics (muscle and joint MRI, T2*-mapping of cartilage, MR-spectroscopy of muscles, functional MRI of the brain, cardiac and vascular cine MRI, whole body MRI) other methods were also used: ice-water pain test, psychometric questionnaires, bioelectrical impedance analysis (BIA), skinfold thickness and limb circumference measurements, daily urine samples, periodic blood samples and electrocardiograms (ECG). RESULTS: Thirty volunteers (68%) reached the finish line at North Cape. The mean total race speed was 8.35 km/hour. Finishers invested 552 hours in total. The completion rate for planned MRI investigations was more than 95%: 741 MR-examinations with 2,637 MRI sequences (more than 200,000 picture data), 5,720 urine samples, 244 blood samples, 205 ECG, 1,018 BIA, 539 anthropological measurements and 150 psychological questionnaires. CONCLUSIONS: This study demonstrates the feasibility of conducting a trial based centrally on mobile MR-measurements which were performed during ten weeks while crossing an entire continent. This article is the reference for contemporary result reports on the different scientific topics of the TEFR project, which may reveal additional new knowledge on the physiological and pathological processes of the functional systems on the organ, cellular and sub-cellular level at the limits of stress and strain of the human body. Please see related articles: http://www.biomedcentral.com/1741-7015/10/76 and http://www.biomedcentral.com/1741-7015/10/77.

Non-invasive pediatric cardiac imaging-current status and further perspectives.

BACKGROUND: Non-invasive cardiac imaging has a growing role in diagnosis, differential diagnosis, therapy planning, and follow-up in children and adolescents with congenital and acquired cardiac diseases. This review is based on a systematic analysis of international peer-reviewed articles and additionally presents own clinical experiences. It provides an overview of technical advances, emerging clinical applications, and the aspect of artificial intelligence. MAIN BODY: The main imaging modalities are echocardiography, CT, and MRI. For echocardiography, strain imaging allows a novel non-invasive assessment of tissue integrity, 3D imaging rapid holistic overviews of anatomy. Fast cardiac CT imaging new techniques-especially for coronary assessment as the main clinical indication-have significantly improved spatial and temporal resolution in adjunct with a major reduction in ionizing dose. For cardiac MRI, assessment of tissue integrity even without contrast agent application by mapping sequences is a major technical breakthrough. Fetal cardiac MRI is an emerging technology, which allows structural and functional assessment of fetal hearts including even 4D flow analyses. Last but not least, artificial intelligence will play an important role for improvements of data acquisition and interpretation in the near future. CONCLUSION: Non-invasive cardiac imaging plays an integral part in the workup of children with heart disease. In recent years, its main application congenital heart disease has been widened for acquired cardiac diseases.

Automatic detection of the carotid artery boundary on cross-sectional MR image sequences using a circle model guided dynamic programming.

BACKGROUND: Systematic aerobe training has positive effects on the compliance of dedicated arterial walls. The adaptations of the arterial structure and function are associated with the blood flow-induced changes of the wall shear stress which induced vascular remodelling via nitric oxide delivered from the endothelial cell. In order to assess functional changes of the common carotid artery over time in these processes, a precise measurement technique is necessary. Before this study, a reliable, precise, and quick method to perform this work is not present. METHODS: We propose a fully automated algorithm to analyze the cross-sectional area of the carotid artery in MR image sequences. It contains two phases: (1) position detection of the carotid artery, (2) accurate boundary identification of the carotid artery. In the first phase, we use intensity, area size and shape as features to discriminate the carotid artery from other tissues and vessels. In the second phase, the directional gradient, Hough transform, and circle model guided dynamic programming are used to identify the boundary accurately. RESULTS: We test the system stability using contrast degraded images (contrast resolutions range from 50% to 90%). The unsigned error ranges from 2.86% ± 2.24% to 3.03% ± 2.40%. The test of noise degraded images (SNRs range from 16 to 20 dB) shows the unsigned error ranging from 2.63% ± 2.06% to 3.12% ± 2.11%. The test of raw images has an unsigned error 2.56% ± 2.10% compared to the manual tracings. CONCLUSIONS: We have proposed an automated system which is able to detect carotid artery cross sectional boundary in MRI sequences during heart cycles. The accuracy reaches 2.56% ± 2.10% compared to the manual tracings. The system is stable, reliable and results are reproducible.

Cardiac structure and function in response to a multi-stage marathon over 4486 km.

AIMS: To investigate whether participation in the Trans Europe Foot Race 2009 (TEFR), an ultramarathon race held over 64 consecutive days and 4486 km, led to changes in cardiac structure and function. METHODS: Cardiac magnetic resonance imaging was performed in 20 of 67 participating runners (two women; mean ± SD age 47.8 ± 10.4 years) at three time points (baseline scan at 294 ± 135 km (B), scan two at 1735 ± 86 km (T1) and scan three at 3370 ± 90 km (T2)) during the TEFR. Imaging included an assessment of left ventricular structure (mass) and function (strain). In parallel, cardiac troponin I, NT-pro-BNP, myostatin and GDF11 were determined in venous blood samples. A subsample of ten runners returned for a follow-up scan eight months after the race. RESULTS: Left ventricular mass increased significantly (B, 158.5 ± 23.8 g; T1, 165.1 ± 23.2 g; T2, 167 ± 24.6 g; p < 0.001) over the course of the race, although no significant change was seen in the remaining structural and functional parameters. Serum concentrations of cardiac troponin I and NT-proBNP significantly increased 1.5 - and 3.5-fold, respectively, during the first measurement interval, with no further increase thereafter (cardiac troponin I, 6.8 ± 3.1 (B), 16.9 ± 10.4 (T1) and 17.1 ± 9.7 (T2); NT-proBNP, 30.3 ± 22.8 (B), 135.9 ± 177.5 (T1) and 111.2 ± 87.3 (T2)), whereas the growth markers myostatin and GDF11 did not change. No association was observed with functional parameters, including the ejection fraction and the volume of both ventricles. The follow-up scans showed a reduction to baseline values (left ventricular mass 157 ± 19.3 g). CONCLUSIONS: High exercise-induced cardiac volume load for >2 months in ultra-endurance runners results in a physiological structural adaptation with no sign of adverse cardiovascular remodelling.

Pathognomonic imaging signs in abdominal radiology.

The imaging evaluation of the abdomen is of crucial importance for every radiologist. In addition to ultrasound, conventional radiographs and contrast-enhanced computed tomography (CT) are the most common imaging procedures in the abdominal region. Numerous pathognomonic signs should be known in this context by every radiologist. Radiographs of the abdomen are an often used first step in radiologic imaging, while CT examinations are carried out for further differentiation, in oncological settings and in time-critical emergency situations. A fast and clear assignment of these signs to a specific disease is the basis for a correct diagnosis. This pictorial review describes the most common pathognomonic signs in abdominal imaging. The knowledge of these pictograms is therefore essential for radiologists interested in abdominal medicine and should also be addressed in training and further education.

Non-invasive determination of pressure recovery by cardiac MRI and echocardiography in patients with severe aortic stenosis: short and long-term outcome prediction.

OBJECTIVE: To assess the influence of pressure recovery (PR)-corrected haemodynamic parameters on outcome in patients with aortic stenosis. METHODS: Aortic stenosis severity parameters were corrected for PR (increase in static pressure due to decreasing dynamic pressure), assessed using transthoracic echocardiography (TTE) or cardiac magnetic resonance imaging (CMR), in patients with aortic stenosis. PR, indexed PR (iPR) and energy loss index (ELI) were determined. Factors that predicted all-cause mortality, and 9-month or 10-year New York Heart Association classification ≥2 were assessed using Cox proportional hazards regression. RESULTS: A total of 25 patients, aged 68 ± 10 years, were included. PR was 17 ± 6 mmHg using CMR, and CMR correlated with TTE measurements. PR correction using CMR data reduced the AS-severity classification in 12-20% of patients, and correction using TTE data reduced the AS-severity classification in 16% of patients. Age (Wald 4.774) was a statistically significant predictor of all-cause mortality; effective orifice area (Wald 3.753) and ELI (Wald 3.772) almost reached significance. CONCLUSIONS: PR determination may result in significant reclassification of aortic stenosis severity and may hold value in predicting all-cause mortality.

Prospectively gated axial CT coronary angiography: preliminary experiences with a novel low-dose technique.

To assess image quality and radiation exposure with prospectively gated axial CT coronary angiography (PGA) compared to retrospectively gated helical techniques (RGH). Forty patients with suspected coronary artery disease (CAD) and a stable heart rate below 65 bpm underwent CT coronary angiography (CTCA) using a 64-channel CT system. The patient cohort consisted of 20 consecutive patients examined using a PGA technique and 20 patients examined using a standard RGH technique. Both groups were matched demographically according to age, gender, body mass index, and heart rate. For both groups, two independent observers assessed image quality for all coronary segments on an ordinal scale from 1 (nonassessable) to 5 (excellent quality). Image quality and radiation exposure were compared between patient groups. There were no significant differences in vessel-based image quality between the two groups (P > 0.05). Mean (+/- SD) effective radiation exposure in the PGA group was 3.7 +/- 0.8 mSv compared to 18.9 +/- 3.8 mSv in the RGH group without ECG-based tube current modulation (P < 0.001). Preliminary experience shows PGA technique to be a promising approach for CTCA resulting in a substantial reduction in radiation exposure with image quality comparable to that of standard RGH technique.

Individualized Biventricular Epicardial Augmentation Technology in a Drug-Induced Porcine Failing Heart Model.

For treatment of advanced heart failure, current strategies include cardiac transplantation or blood-contacting pump technology associated with complications, including stroke and bleeding. This study investigated an individualized biventricular epicardial augmentation technology in a drug-induced porcine failing heart model. A total of 11 pigs were used, for the assessment of hemodynamics and cardiac function under various conditions of support pressures and support durations (n = 4), to assess device positioning and function by in vivo computer tomographic imaging (n = 3) and to investigate a minimally invasive implantation on the beating heart (n = 4). Support pressures of 20-80 mm Hg gradually augmented cardiac function parameters in this animal model as indicated by increased left ventricular stroke volume, end-systolic pressures, and decreased end-diastolic pressures. Strong evidence was found regarding the necessity of mechanical synchronization of support end with the isovolumetric relaxation phase of the heart. In addition, the customized, self-expandable implant enabled a marker-guided minimally invasive implantation through a 4 cm skin incision using fluoroscopy. Correct positioning was confirmed in computer tomographic images. Continued long-term survival investigations will deliver preclinical evidence for further development of this concept.