Philips Medical Systems Research Articles

Elucidating the mechanism of rapid functional recovery following atrial fibrillation ablation in patients with left ventricular systolic dysfunction

Abstract Introduction Successful sinus rhythm restoration by catheter ablation (CA) of atrial fibrillation (AF) rapidly improves cardiac function in patients with left ventricular (LV) systolic dysfunction. However, the underlying mechanism of this recovery remains unknown. Purpose To elucidate the mechanism of the functional recovery after CA of AF and systolic dysfunction. Methods We retrospectively examined 4001 consecutive patients who underwent first-time CA of AF between 2012 and 2021 at our institution. Of them, 505 patients had baseline LV ejection fraction (LVEF) of <50%. Among them, we enrolled 454 patients who received electrocardiogram-gated contrast-enhanced 256-slice multi-detector computed tomography (MDCT) (Brilliance iCT, Philips Medical Systems, Cleveland, Ohio) both at baseline and 3 months after CA. Changes in LV measures, wall thickness, and LV mass were examined based on MDCT data. Results A reduction of LV end-systolic volume (LVESV) (from 71 ± 37 ml to 46 ± 34 ml, p <0.001) and improvement of LVEF (from 39 ± 9% to 62 ± 14%, p <0.001) were observed after CA. However, there was no significant change in LV end-diastolic volume (LVEDV) (from 118 ± 49 ml to 116 ± 46 ml, p = 0.13). Mean wall thickness during diastole did not change (from 7.1 ± 1.4 mm to 7.1 ± 1.4 mm, p = 0.94), either. However, wall thickness during systole significantly changed after CA (from 10.0 ± 1.7 mm to 12.7 ± 2.8 mm, p <0.001). As a result, there was no significant change in LV mass after CA (from 84.3 ± 28.7 g to 84.4 ± 28.1 g, p = 0.88). A regression analysis revealed a significant inverse correlation between the delta LVEF and delta LVESV (r = -0.59, p <0.001). However, the delta LVEF was not correlated with the delta LVEDV and delta LV mass. Conclusions The rapid improvement of LVEF after CA of AF was attributed to a decrease in the LVESV. Unchanged LV mass indicated that this functional recovery was solely a mechanical issue, without evidence of myocyte regression.

Magnetic resonance lymphangiography: Establishing normal

BackgroundDespite an increased interest in visualizing the lymphatic vessels with magnetic resonance lymphangiography (MRL), little literature is available describing their appearance in nonlymphedematous individuals. To determine lymphatic abnormalities, an understanding of how healthy lymphatic vessels appear and behave needs to be established. Therefore, in this study, MRL of individuals without a history of lymphatic disease was performed. MethodsA total of 25 individuals (15 women) underwent MRL of their lower limbs using a 3.0 T Philips magnetic resonance imaging scanner (Philips Medical Systems). The first nine participants were recruited to establish the concentration of gadolinium-based contrast agent (GBCA) to administer, with the remainder imaged before and after interdigital forefoot GBCA injections at the optimized dose. Outcomes, including lymphatic vessel diameter, tortuosity, and frequency of drainage via particular drainage routes, were recorded. ResultsHealthy lymphatic vessels following the anteromedial pathway were routinely observed in post-contrast T1-weighted images (average tortuosity, 1.09 ± 0.03), with an average of 2.16 ± 0.93 lymphatic vessels with a diameter of 2.47 ± 0.50 mm crossing the anterior ankle. In six limbs, vessels following the anterolateral pathways were observed. No vessels traversing the posterior of the legs were seen. In a subset of 10 vessels, the lymphatic signal, measured at the ankle, peaked 29 minutes, 50 seconds ± 9 minutes, 29 seconds after GBCA administration. No lymphatic vessels were observed in T2-weighted images. ConclusionsContrast-enhanced MRL reliably depicts the lymphatic vessels in the legs of healthy controls. Following interdigital contrast injection, anteromedial drainage appears dominant. Quantitative measures related to lymphatic vessel size, tortuosity, and drainage rate are readily obtainable and could be beneficial for detecting even subtle lymphatic impairment.

Comparison of image quality and standardized uptake values (SUV) of two PET/CT imaging system using F-18 and Ga-68

Both the Gemini TOF PET/CT and Biograph mCT flow PET/CT scanners are advanced imaging systems used in clinical settings for a range of applications, including oncology, neurology, and cardiology. Both the Gemini TOF PET/CT and Biograph mCT flow PET/CT scanners are advanced imaging systems used in clinical settings for a range of applications, including oncology, neurology, and cardiology. Both systems are capable of producing high quality images with good spatial resolution and contrast. However, there are some differences between the two systems that may impact image quality. The recovery coefficient (RC) is an important parameter that is used to evaluate the image quality and the accuracy and precision of PET/CT imaging systems. In the other hand, Standardized uptake value (SUV) is A frequently utilized quantitative measure in PET/CT imaging is the estimation of radiotracer uptake within a specified region of interest (ROI). SUV measurements are possible to be used to assess tumor metabolism and monitor treatment response. Several studies have evaluated the SUV and RC measurements using different radiotracers and scanner has been found to exhibit good accuracy and precision for both radiotracers. In this work we investigated the SUV and RC values of the Gemini TOF PET/CT and Biograph mCT flow PET/CT scanners by using F18 and Ga-68 and compared their values. Methods in this work, we analyzed images acquired using two distinct PET-CT scanners from two different manufacturers; Gemini TOF PET/CT (Philips Medical Systems) system and biograph mCT flow PET/CT system (Siemens Healthineers). we assessed the SUV values by using the PET-CT cylindrical image quality NEMA phantom that was filled with F-18 and Ga-68 while the image quality measured by employing the NEMA/International Electrotechnical Commission (IEC) Torso Phantom. Results We revealed that the RC values of F-18 using Gemini TOF PET/CT ranged from 0.02 to 0.03 for different sphere sizes, where they ranged from 0.005 to 0.015 for Ga-68 and when used Biograph mCT flow PET/CT scanner RC values of F-18 ranged from 0.025 to 0.05 and for Ga-68 ranged from 0.02 to 0.042. The first section in your paper

Real-time three-dimensional transthoracic echocardiography in quantification of left ventricular dyssynchrony

Aim. To compare endocardial and epicardial left ventricular (LV) pacing using real-time electrocardiography (ECG)-synchronized three-dimensional echocardiography (3DE).Methods. Experimental intraoperative study included 88 points obtained from 12 patients with compensated heart failure of II-IV functional class NYHA (LV ejection fraction < 35%) and cardiac resynchronization therapy indications - ECG pattern of complete left bundle branch block (LBBB) and QRS complex duration > 150 ms. During isolated LV pacing as part of cardiac resynchronization therapy implantation procedure endocardial and epicardial stimulation points matched under fluoroscopic control using quadripolar coronary sinus leads and endocardial electrodes for temporary pacing were obtained. The overall number of corresponding pacing sites included 44 endocardial and 44 epicardial stimulation positions. The mean age of patients was 68.5 [63; 73.5] years, 83% males (n=10). Before study enrollment, 12-channel ECG, echocardiography, and a six-minute walk test were performed for all participants along with cardiac magnetic resonance imaging and control coronary angiography if indicated. The prevalence of coronary heart disease was 50% (n=6) while dilated cardiomyopathy was the most common etiology of chronic heart failure in other cases. Intraoperative ECG with estimation of paced QRS complex morphology at each point was registered via LabSystem Pro Electrophysiological Recording System (Bard Electrophysiology, USA). 3DE was performed using TomTec and Philips Qlab 3DQ Advanced software (Philips Medical Systems, USA).Results. Three-dimensional parametric imaging of LV regional segmental excursion and myocardial contractility using 3DE revealed statistically significant difference in semi-quantative parameters such as ExcAvg (p<0.001), ExcMax (p=0.001), ExcMin (p<0.001) and LV ejection fraction based on 3D modelling (p=0.003) while endocardial pacing was more beneficial. During the course of endocardial stimulation, the 3DE dyssynchrony index estimated at the 2nd stimulation site was also significantly lower (p=0.03). Identical dyssynchrony parameters valid for the 16 and 12-segment 3D models (SDI-16, Tmsv-12SD) (at p=0.06) demonstrated only a tendency for significant difference. The duration of QRS complex at the time of endocardial pacing was significantly shorter (<190 [179;215] ms) (p=0.0008). Semi-quantitative and quantitative 3DE parameters showed the benefit of endocardial pacing resulting in cardiac contractility improvement with less dyssynchrony and LV volume reducing during intraoperative period.Conclusion. Endocardial pacing has potential benefit over the epicardial pacing represented by intraoperative dynamics of LV global and local contractility, intraventricular dyssynchrony estimated by 3DE and also ECG criteria. 3DE is helpful in more precise and reproducibile determing of late activation zone for target LV lead placement that is more manoeuvrable in case of endocardial stimulation.

3D-modeling Capabilities in Assessing Resectability of Pancreatic Head Tumors

Background. Pancreatic head cancer ranks 6–7th among oncologic diseases and 4–5th among causes of mortality, with only 5% of patients achieving 5-year survival rate to date. Despite the successes of modern diagnostics and surgical treatment, the problem of early detection, staging of oncologic process and, as a consequence, combined treatment of pancreatic head cancer remains actual.Objective: increasing the accuracy of diagnostics and estimation of resectability of the pancreatic head cancer on the basis of the complex use of the radiation methods of investigation with pancreaticoduodenal zone 3D-reconstructions.Material and methods. The study included 93 patients (44 (47.31%) males and 49 (52.69%) females) with complicated pancreatoduodenal masses treated from 2019 to 2022 at the Surgical Department of the City Mariinsky Hospital. The patients’ age varied from 44 to 90 years, the mean age was 67±0.74 years. All patients underwent magnetic resonance imaging (MRI) on an Ingenia MR tomograph (Philips Medical Systems, Netherlands) with a magnetic field induction of 3 Tesla. The native examination of the abdomen and retroperitoneum, supplemented with MR-cholangiopancreatography protocol, and dynamic contrast enhancement with data collection in arterial, portal, and delayed phases were carried out. T2-weighted images were then performed using turbospin-echo technology, including fat-suppressed images, to evaluate structural changes and the presence of fluid in fascial spaces. Patients also underwent endoscopic ultrasound of the pancreaticoduodenal zone using the push and pull method, and abdominal multislice computed tomography (MSCT). To build 3D models, we used free 3D-slicer and Mimics programs, which allowed to build semi-automatic model for further evaluation of anatomo-topographic relations.Results. MSCT 3D modeling revealed tumor invasion into the superior mesenteric vein in 6 (23.06%) patients, whereas MRI models showed tumor invasion in 4 (15.38%) patients, intraoperatively the results were confirmed in 5 patients (19.23%). According to both MSCT and MRI modeling data, the invasion of the ventral trunk occurred in 1 (5.2%) case, which was confirmed intraoperatively. Inferior vena cava invasion on MSCT and MRI models was detected in 3 (11.54%) patients, whereas intraoperatively – in 4 (15.38%) patients. The MSCT and MRI 3D models coincided with the data on invasion of the ventral trunk in 1 (3.85%) patient and the superior mesenteric artery in 2 (7.69%) patients, which was fully confirmed intraoperatively.Conclusion. 3D modeling on the basis of MRI and MSCT studies is an informative method in preoperative staging of pancreatic head cancer and its resectability. This method allows to objectively determine the localization and prevalence of the tumor process on adjacent anatomical structures, as well as visually demonstrate the metastatic lesion of regional lymph nodes. By the parameters of diagnostic efficiency, 3D models are maximally close to the intraoperative picture, which allows planning both the volume and the course of surgical intervention.

A new predictive parameter for dose-volume metrics in intensity-modulated radiation therapy planning for prostate cancer: Initial phantom study.

Organ-at-risk (OAR) sparing is often assessed using an overlap volume-based parameter, defined as the ratio of the volume of OAR that overlaps the planning target volume (PTV) to the whole OAR volume. However, this conventional overlap-based predictive parameter (COPP) does not consider the volume relationship between the PTV and OAR. We propose a new overlap-based predictive parameter that consider the PTV volume. The effectiveness of proposed overlap-based predictive parameter (POPP) is evaluated compared with COPP. We defined as POPP=(overlap volume between OAR and PTV/OAR volume) × (PTV volume/OAR volume). We generated intensity modulated radiation therapy (IMRT) based on step and shoot technique, and volumetric modulated arc therapy (VMAT) plans with the Auto-Planning module of Pinnacle3 treatment planning system (v14.0, Philips Medical Systems, Fitchburg, WI) using the American Association of Physicists in Medicine Task Group (TG119) prostate phantom. The relationship between the position and size of the prostate phantom was systematically modified to simulate various geometric arrangements. The correlation between overlap-based predictive parameters (COPP and POPP) and dose-volume metrics (mean dose, V70Gy, V60Gy, and V37.5Gy for rectum and bladder) was investigated using linear regression analysis. Our results indicated POPP was better than COPP in predicting intermediate-dose metrics. The bladder results showed a trend similar to that of the rectum. The correlation coefficient of POPP was significantly greater than that of COPP in<62Gy (82% of the prescribed dose) region for IMRT and in<55Gy (73% of the prescribed dose) region for VMAT regarding the rectum (p<0.05). POPP is superior to COPP for creating predictive models at an intermediate-dose level. Because rectal bleeding and bladder toxicity can be associated with intermediate-doses as well as high-doses, it is important to predict dose-volume metrics for various dose levels. POPP is a useful parameter for predicting dose-volume metrics and assisting the generation of treatment plans.

Clinical utility and prognostic value of right atrial function in severe tricuspid regurgitation. One more piece of the puzzle

Abstract Background Optimal management of severe tricuspid regurgitation (TR) remains controversial. While right ventricular systolic function is an established prognostic marker of outcomes, the potential role of right atrial (RA) function is unknown. Purpose This study aimed to describe RA function by 2D speckle tracking echocardiography (STE) in at least severe TR and to evaluate its potential association with cardiovascular outcomes. Methods Consecutive patients with at least (≥) severe TR (severe, massive or torrential TR) evaluated in the Heart Valve Clinic following a comprehensive clinical protocol were included. Consecutive control subjects and patients with permanent isolated AF were included for comparison (control and AF group respectively). RA function was measured with 2D-STE and RA reservoir strain (RASr) was calculated in all subjects (figure 1, AutoStrain, Philips Medical Systems the EPIQ system). The interobserver variability of RA strain was assessed in 30 randomly selected subjects (20 TR+5 AF+5 controls). A combined endpoint of hospital admission due to heart failure (HF) or all cause mortality was defined. Results A total of 227 patients with severe TR, 20 AF patients and 20 controls subjects were included in this study. Patients with at least severe TR showed lower RASr compared to controls and to AF patients (p&amp;lt;0,05). After a median follow-up of 26 months (IQR: 15-48 months), n=83 patients with severe TR (37%) reached the combined endpoint. Patients with events showed lower values of RASr (p&amp;lt;0,01 for both). RASr was an independent predictor of heart failure and all cause mortality adjusted by additional imaging prognostic parameters in a multivariable analysis (biplane vena contracta, RV end-diastolic area, and RV- free wall longitudinal strain [LR Chi2 : 49,7, p&amp;lt;0,001]). RA area or volume was not associated with outcomes. A cut-off value of RASr of &amp;lt;10% held the best accuracy to predict outcomes (adjusted HR 3,8 (2,4-6,1), p&amp;lt;0,001, figure 2). Inter-observer agreements for RA strain values across the whole cohort were high (intraclass correlation coefficient for RASr, RAScd and RASct, r= 0,95, r=0,86, r=0,92 respectively). Conclusions Evaluation of RA function by 2D-STE is feasible, reproducible and is an independent predictor of heart failure and all-cause mortality in patients with at least severe TR.LA STRAINKaplan Meier Curves

Abstract 14203: Speckle Tracking Analysis During Dobutamine Stress Echocardiography in Patients Undergoing Percutaneous Coronary Intervention for Chronic Total Occlusion

Background: Dobutamine stress echocardiography (DSE) is often used as a non-invasive diagnostic modality for detection of myocardial ischemia and viability. A “biphasic response” in DSE can occur, in which contractility improves in dysfunctional segments with low dose stage and then becomes dysfunctional again at higher doses due to ischemia. We investigated if speckle tracking analysis during DSE can evaluate patients undergoing percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). Methods: DSE was performed one day before CTO-PCI in consecutive 30 patients (18 female, age=71±11 years). Since 27 patients had 1 vessel, and 3 patients had 2 vessel CTO lesions, total of 33 regions were analyzed. Global (GLS) and regional longitudinal strain (RLS) were calculated as an averaged value of peak longitudinal strain in the apical 4-, 2-chamber, and long axis views at baseline echo, at low-dose, at high-dose DSE, and 6 months after CTO-PCI using available software (QLAB, Philips Medical Systems). Results: CTO-PCI was successfully done in all patients. GLS and RLS were feasible in all regions. Overall, GLS (-15.5±2.8 at baseline v.s. -17.3±3.8, p&lt;0.001) and left ventricular ejection fraction (LVEF) (56±6% v.s. 58±7%, p&lt;0.01) significantly improved 6 months after CTO-PCI. There was also significant improvement of RLS for the obstructed CTO regions (-13.8±3.6 v.s. -16.5±4.2, p&lt;0.005). Although in 24 patients (26 regions) with biphasic response during DSE (Figure), GLS (-15.7±2.5 v.s. -17.9±3.6, p&lt;0.01), LVEF (54±6% v.s. 56±7%, p&lt;0.05), and RLS (-13.8±3.5 v.s. -16.8±4.0, p&lt;0.01) improved significantly, GLS (-14.9±4.2 v.s. -15.8±5.0, p=n.s.), LVEF (59±3% v.s. 60±3%, p=n.s.), and RLS (-13.9±4.5 v.s. -15.5±5.7, p=n.s.) didn’t change in 6 patients (7 regions) without biphasic response. Conclusion: Speckle tracking analysis is feasible during DSE. CTO-PCI may improve both global and regional cardiac functions in patients with myocardial viability.

John Maynard Keynes Narrates the Great Depression: His Reports to the Philips Electronics Firm

In October 1929, the Dutch electronics firm Philips approached John Maynatd Keynes to write confidential reports on the state of the British and world economies, which he did from January 1930 to November 1934, at first monthly and then quarterly. These substantial reports (Keynes’s November 1931 report was twelve typed pages) show Keynes narrating the Great Depression in real time, as the world went through the US slowdown after the Wall Street crash, the Credit-Anstalt collapse in Austria, the German banking crisis (summer 1931), Britain’s departure from the gold exchange standard in August and September 1931, the US banking crisis leading to the Bank Holiday of March 1933, the London Economic Conference of 1933, and the coming of the New Deal. This series of reports has not been discussed in the literature, though the reports and surrounding correspondence are in the Chadwyck-Healey microfilm edition of the Keynes Papers. We examine Keynes’s account of the unfolding events of the early 1930s, his insistence that the crisis would be more severe and long-lasting than most observers predicted, and his changing position on whether monetary policy would be sufficient to promote recovery and relate his reading of contemporary events to his theoretical development.

Usability of Automated External Defibrillators: A Randomized, Comparative Simulator Study

The aim of this study was to investigate whether one particular automated external defibrillator (AED) is superior to another in use by a layperson such that there is a clinically relevant difference from first contact with the device to the time of shock delivery (TimeToShock (TTS)). Causes for interaction problems and delays were analyzed. The study was conducted as a randomized, two-arm manikin study using the AED training devices “Lifepak CR-T AED Trainer” (Medtronic Physio-Control) and “AED Trainer 3” (Philips Medical Systems). In each study arm, the participants used one of the AEDs in a simulated resuscitation. The interaction was recorded by a mobile eye tracker. The TTS was compared with the Wilcoxon rank-sum test. The study was conducted with 28 participants inexperienced in AED use. A significant difference (p < 0.05) in TTS was measured at 32.5 s median between the two devices (61 s (IQR: 58 s–76 s, range: 51 s–115 s) for the AED Trainer 3 and 93.5 s (IQR: 91 s–103 s, Range: 80 s–129 s) for the Lifepak CR-T AED Trainer). Causes of delays and interaction problems included differences in the use of voice instruction (length, pauses, and terminology), iconography on the device and electrodes, and device opening mechanisms. The measured clinically relevant difference can be attributed to the usability of the interaction elements, which differ significantly between the devices. Besides specific design elements, the extent of user guidance provided by the AEDs is crucial for efficient and error-free interaction.

Otonom kortizol sekresyonu olan hastalarda ve fonksiyonel olmayan adrenal kitleleri olan hastalarda viseral yağ dokusunun karşılaştırılması

Purpose: This study aimed to explore the impact of continuous autonomous cortisol secretion on visceral (VAT), abdominal subcutaneous (SAT) adipose tissue, and total body fat.&#x0D; Materials and Methods: A total of 57 patients (36 female, 21 male) with adrenal masses, referred to our single center, were included in this study. Among them, 31 patients had adrenal cortical carcinoma (ACS) and 26 had nonfunctional adrenal mass (NFAM). Hormonal evaluation was conducted for all patients. Measurements of total, visceral, and subcutaneous adipose tissue were performed using 3.0 T magnetic resonance imaging (Ingenia, Philips Medical Systems, Best, The Netherlands).&#x0D; Results: Mean age, gender distribution, and body mass index (BMI) were comparable between patients with ACS and NFAM. Patients with ACS exhibited higher volumes of both total (422.1±131.3 vs. 346.2±86.0 cm3) and visceral adipose tissue (199.9±77.3 vs. 160.6±60.8 cm3) compared to those with NFAM. Incidence rates of diabetes mellitus and hepatosteatosis were similar in both groups. Subcutaneous adipose tissue volumes, visceral-to-subcutaneous ratio, and visceral-to-total fat ratio showed no significant differences between the two groups.&#x0D; Conclusion: Patients with ACS demonstrated increased total and visceral fat tissue volumes compared to NFAM patients matched for gender, age, and BMI. This observation may elucidate the potential influence of continuous mild autonomous cortisol secretion in ACS patients. Such findings could serve as indicators of heightened cardiovascular risk among ACS patients.

Malignant and Benign Peripheral Nerve Sheath Tumors in a Single Center: Value of Clinical and Ultrasound Features for the Diagnosis of Malignant Peripheral Nerve Sheath Tumor Compared With Magnetic Resonance Imaging.

This study aimed to investigate the combined use of ultrasonography and clinical features for the differentiation of malignant peripheral nerve sheath tumors (MPNST) from benign peripheral nerve sheath tumors (BPNST) and to compare the efficacy of ultrasonography with that of magnetic resonance imaging (MRI). This retrospective study included 28 MPNSTs and a control group of 57 BPNSTs. All patients underwent an ultrasound scan using the Logiq E9 (GE Health Care, Milwaukee, WI) or EPIQ7 equipment (Philips Medical System, Bothell, WA). A 3.0-T MRI machine (Ingenia; Philips Healthcare, Best, the Netherlands) was used for scanning, and conventional MRI was performed on different regions based on the patient's clinical situation. The following variables were evaluated: palpable mass, pain, nerve symptoms, maximum diameter, location, shape, boundary, encapsulation, echogenicity, echo homogeneity, presence of a cystic component, calcification, target sign, posterior echo, and intertumoral vascularity of the tumors. The diagnostic efficacy of ultrasonography and clinical factors was compared with that of MRI. Independent factors for predicting MPNST versus BPNST were also assessed. The parameters of location, shape, boundary, encapsulation, and vascularity were significantly different between MPNSTs and BPNSTs. Multiple logistic regression analysis showed that shape, boundary, and vascularity were independent predictors of MPNSTs. The sensitivity, specificity, and Youden index of the three clinical and ultrasound factors (shape, boundary, and vascularity) were 0.89, 0.81, and 0.69, respectively, whereas those of MRI were 0.71, 0.89, and 0.61, respectively. No significant differences in the area under the curve (AUC) of the three combined clinical and ultrasound factors and those of MRI were found (P > .05). MRI was useful in the differential diagnosis between MPNSTs and BPNSTs. However, the combination of clinical and ultrasound diagnoses can achieve the same effect as MRI, including shape, boundary, and vasculature.

Clinical utility and prognostic value of right atrial function in severe tricuspid regurgitation: one more piece of the puzzle.

The optimal management of severe tricuspid regurgitation (TR) remains controversial. While right ventricular systolic function is an established prognostic marker of outcomes, the potential role of right atrial (RA) function is unknown. This study aimed to describe RA function by 2D speckle-tracking echocardiography (STE) in at least severe TR and to evaluate its potential association with cardiovascular outcomes. Consecutive patients with at least (≥) severe TR (severe, massive, or torrential TR) evaluated in the Heart Valve Clinic following a comprehensive clinical protocol were included. Consecutive control subjects and patients with permanent isolated atrial fibrillation (AF) were included for comparison (control and AF group, respectively). RA function was measured with 2D-STE and two components of RA function were calculated: reservoir (RASr) and contractile (RASct) strain (AutoStrain, Philips Medical Systems the EPIQ system). A combined endpoint of hospital admission due to heart failure (HF) or all-cause mortality was defined. Patients with ≥ severe TR (n = 140) showed lower RASr compared with controls (n = 20) and with the AF group (n = 20) (P < 0.001). Atrial TR showed lower RASr compared with other aetiologies of TR (P < 0.001). After a median follow-up of 2.2 years (IQR: 12-41 months), RASr remained an independent predictor of mortality and HF. A cut-off value of RASr of <9.4% held the best accuracy to predict outcomes. RA function by 2D-STE independently predicts mortality and HF hospitalizations in patients with ≥ severe TR.

Dynamic monitoring of morphological and hemodynamic evolution of small cerebral aneurysms

Highlights. Small cerebral aneurysms (&lt;3 mm), which make up the majority of aneurysms, rupture more frequently, although medium (&gt;3 mm) and giant (&gt;15 mm) aneurysms and have a higher risk of rupture. This article proves for the first time that the rupture risk criteria developed for giant cerebral aneurysms do not work for small aneurysms. The development of small aneurysms in patients was analyzed and measured morphological features of aneurysms were compared with their calculated hydrodynamic characteristics.Aim. To study the dynamics of development of small cerebral aneurysms, to assess the applicability of existing methods for calculating the risk of rupture, to formulate new clarifying hypotheses for calculating the risk of rupture of small cerebral aneurysms.Methods. Patient data were provided by the Federal Center for Neurosurgery, Novosibirsk. CT angiography was performed using a Philips Ingenuite CT scanner (Philips Medical Systems, USA, 128 slices). Aneurysm size dynamics was assessed by measuring three main sizes with an accuracy of 0.1 mm using the IntelliSpace Portal Philips software environment. Numerical calculations were carried out using ANSYS CFX 2020R2.Results. Hemodynamic characteristics change according to the changes of the aneurysm dome. In the case when morphological characteristics of the aneurysm have not changed, a change in the geometry of the patient's circle of Willis (coW) is observed: the curvature of the arteries, the angles of bifurcations (the structure of coW remained unchanged). The PHASES score (absolute risks of rupture for aneurysms) was found to be unusable for the considered aneurysms.Conclusion. This work formulates and morphologically and hydrodynamically confirms for the first time in the volunteers that the change in risk estimates for such aneurysms is fundamentally affected, even insignificantly, by the change in the circle of Willis: a change in the curvature of individual segments of the cerebral arteries, as well as the angles of their bifurcations. The results obtained are aimed at modifying the existing risk criteria for rupture of cerebral aneurysms.

Proposed Institutional Diagnostic Reference Levels in Computed and Direct Digital Radiography Examinations in Two Teaching Hospitals

Background: The detectors of both computed radiography (CR) and direct digital radiography (DR) have a wide dynamic range that could tolerate high values of exposure factors without an adverse effect on image quality. Therefore, this study aims to assess patient radiation dose and proposes institutional diagnostic reference levels (DRLs) for two teaching hospitals in Ghana.Materials and Methods: CR and DR systems were utilized in this study from two teaching hospitals. The CR system was manufactured by Philips Medical Systems DMC GmbH, while the DR system was manufactured by General Electric. The entrance skin doses (ESDs) were calculated using the standard equation and the tube output measurements. Free-in-air kerma (μGy) was measured using a calibrated radiation dosimeter. The proposed institutional DRLs were estimated using 75&lt;sup&gt;th&lt;/sup&gt; percentiles values of the estimated ESDs for nine radiographic projections.Results and Discussion: The calculated DRLs were 0.4, 1.6, 3.4, 0.5, 0.4, 1.1, 1.0, 1.2, and 1.7 mGy for chest posteroanterior (PA), lumbar spine anteroposterior (AP), lumbar spine lateral (LAT), cervical spine AP, cervical spine LAT, skull PA, pelvis AP, and abdomen AP, respectively in CR system. In the DR system, the values were 0.3, 1.6, 3.1, 0.4, 0.3, 0.7, 0.6, 0.9, and 1.3 for chest PA, lumbar spine AP, lumbar spine LAT, cervical spine AP, cervical spine LAT, skull PA, pelvis AP, and abdomen AP, respectively.Conclusion: Institutional DRLs in nine radiographic projections have been proposed for two teaching hospitals in Ghana for the first time. The proposed DRLs will serve as baseline data for establishing local DRLs in the hospitals and will be a valuable tool in optimizing patient doses.

Magnetic Resonance Imaging in Traumatic Brachial Plexus Injuries: A 6-Year Experience.

Background and Purpose: There is limited information in the literature on epidemiology of high-energy brachial plexus injuries evaluated with MR neurography (MRN). The aim of the present study is to describe the demographic characteristics of brachial plexus injuries secondary to motorcycle accident patients in the city of Fortaleza-Ceara, Brazil, and analyze the association of those data with the features of the brachial plexus lesions observed on MRN findings. Materials and Methods: A review of sixty medical charts and MRN findings of victims of motor vehicle accidents (MVA) in northeast, from November 2011 to November 2017. Demographic and imaging data collected included age, sex, laterality and level of the lesion and time interval between trauma and MRN examination. The MRN examinations were carried out on a GE 1.5T MR unit (Signa HDxT- General Electric, Milwaukee, USA) or on a Phillips 3T MR unit (Philips Achieva X-series - Philips Medical Systems, Best, The Netherlands). Dedicated multichannel phased-array coils. Results: The longest time interval from trauma to imaging was 330 days and between trauma and surgery was 692 days. Preganglionic lesions (avulsion) predominated, consisting of 52 patients (86.6%) reflecting the high energy trauma with upper limb traction from the neck. The lesions were most prevalent at the C6-C8 levels. Pseudomeningocele was identified in 62.9% of the preganglionic lesions and in only 1.6% of the postganglionic lesions. Regional muscle denervation changes were seen in all pre-ganglionic injuries and most of post-ganglionic injuries. Conclusions: MRN of the brachial plexus provides important insights into the distribution of neuromuscular lesions in high energy MVA trauma and these findings enrich the literature for researchers and clinicians focused on managing such patients and/or defining prognostic strategies.

Marked PR interval variability in a patient with Brugada syndrome.

To the Editor The authors present a clinical case of a 54-year-old woman without relevant medical history other than Brugada type 1 pattern in the electrocardiogram, without chronic medication, who was referred for the cardiology outpatient clinic with palpitations. She had a strong family history of Brugada syndrome, but no history of sudden death, and she never had syncope. A transthoracic echocardiogram was performed, ruling out structural heart disease. Blood samples were analyzed, without thyroid function or electrolyte abnormalities. A 24-hour Holter examination was performed (digital Philips Zymed Holter, Model 1810 Plus Software, Philips Medical Systems) that revealed nocturnal periods of first-degree atrioventricular block (AVB) with a markedly variable PR interval and without nonconducted P waves; no other abnormalities were seen; the patient was asymptomatic. The P wave and QRS morphology were the same throughout the examination. The PR interval either increased or decreased, but it was always followed by a QRS complex. The number of P waves was the same as the QRS complexes. There was no relation between the PR interval variability and heart rate or circadian predominance. The patient is kept under follow-up in the outpatient clinic, uneventful. No genetic test was performed. First-degree AVB is typically a benign situation1; however, it is associated with increased incidence of atrial fibrillation, heart failure, and mortality during follow-up.2 In some clinical settings, it can even be associated with markedly decreased survival.3 Some data point out that first-degree AVB on a basal ECG is an independent predictor of malignant arrhythmic events in Brugada syndrome (although this association was only demonstrated with first-degree AVB on basal ECG and not on Holter examination).4,5 The PR interval is highly affected by the autonomic nervous system.6-9 Sympathetic activation results in a decrease of the PR interval, whereas parasympathetic activation originates an increase of the PR interval.6,7 Previous studies showed that the increase in PR interval in response to vagal stimulation is well correlated with vagal stimulation frequency and can be regarded as linear.7 The Brugada syndrome is diagnosed in the presence of a spontaneous type 1 pattern in patients without other heart disease, regardless of symptoms.10 It is a genetic sodium-related (INa) channelopathy.10 The most common gene involved is the SCN5A, which is also associated with conduction diseases.11 Sodium currents are responsible for propagation of action potential through the myocardial cells. As patients with Brugada syndrome have reduced INa current, conduction disease is not unexpected to occur, if the SCN5A gene is involved.12 First-degree AVB could represent a marker of increased risk because of a stronger phenotype of INa reduction, leading to increased myocardial electrical instability.5 Other identified risk markers are the localization of type 1 Brugada pattern (Figs. 1 and 2), atrial fibrillation, fragmented QRS, QRS duration >120 ms, R wave in lead aVR, S wave in lead I (≥40 ms, amplitude ≥0.1 mV, area ≥1 mm2), early repolarization pattern in inferolateral leads, ST segment depression, T‐wave alternans, dispersion of repolarization, and Tzou criteria.11 In another recent study, the S wave in lead I was the only independent predictor of persistent risk of life-threatening arrhythmic events.13Figure 1.: ECG revealing sinus rhythm with type 1 Brugada pattern.Figure 2.: (A) Holter revealing sinus rhythm with type 2 Brugada pattern and first-degree AVB with a progressive PR interval prolongation; (B) continuation of previous Holter stripe; and (C) variable PR interval, always followed by a QRS complex. A type 1 Brugada pattern was not present in this examination.The significance of this PR interval variability, with a “harmonic” appearance, is not yet known, as well as its clinical implications.

Abstract No. 138 Safety and Efficacy of Portal Vein Embolization after Hepatic Arterial Infusion Pump Placement

Hepatic arterial infusion (HAI) combined with systemic chemotherapy is used to treat patients with advanced liver cancers in a staged operative approach. At the time of HAI pump placement, upwards of 60% of patients require ligation of aberrant hepatic arteries. We sought to characterize the safety and efficacy of portal vein embolization (PVE) for inducing liver hypertrophy in patients who underwent HAI with and without hepatic arterial ligation. An IRB-approved retrospective review was conducted on all patients who underwent PVE between the years of 2015 and 2022, with and without preceding or subsequent HAI. Segmental liver volumes, the standardized future liver remnants (sFLR), percent volumetric changes, and the kinetic growth rates (KGR) were calculated using semi-automatic liver segmentation (IntelliSpace, Version 11.1, Philips Medical Systems, Netherlands) performed on multiphasic liver computed tomography scans prior to and 4-12 weeks after PVE. The impact of hepatic artery ligation was assessed by analyzing hepatic resection outcomes following PVE. Between January 2015 and August 2022, 48 patients underwent technically successful PVE with 12 (25%) having a HAI pump as part of their operative clearance strategy. There were 9 HAI pumps (19%) placed before PVE and 3 (6%) after PVE. Among the 9 patients who underwent PVE after HAI, sFLR increased from 21.1 ± 6.8% (mean ± std) to 34.8 ± 6.0%, with KGR of 2.2 ± 1.8% (3 patients had KGRs below 2% but sFLR >30% prior to hepatectomy). Seven (78%) of these patients had hepatic artery ligation during HAI pump placement including 5 replaced right hepatic arteries and 5 accessory left hepatic arteries (4 patients required ligation of both). All patients with ligated right hepatic arteries developed robust intrahepatic left-to-right collateralization prior to PVE. Of these 9 patients, 5 (56%) proceeded to an extended right hepatectomy, 1 (11%) to a right hepatectomy. Three patients did not undergo hepatic resection due to interval development of extrahepatic disease. The median time from PVE to hepatic resection was 59 days. There were no biliary complications in the patients treated with PVE after HAI. PVE to induce liver hypertrophy in sequence with HAI for patients with advanced liver cancer was not associated with increased biliary complication or compromised hepatic function. HAI with or without prior hepatic arterial ligation should not be used to exclude patients from PVE.

Exploring Brain Connectivity of Single-Digit and Double-Digit in Familiar and Unfamiliar Numerals: A Functional MRI Study

Learning and memory are closely related in a way that the ability to learn new information is done through working memory and the retrieval of the learned information is done through long-term memory [1]. Over the years, a keen interest in investigating the functional network and interaction in the brain regions during processing number magnitudes has increased among cognitive neuroscientists [2]. The majority of studies related to brain connectivity, especially on numeral cognition focus on children as these investigations could provide insight into neurodevelopmental performance [3].&#x0D; &#x0D; In the current study, we aim to explore brain connectivity associated with familiar and unfamiliar numerals of single-digit and double-digit among young adults. Figure 1 demonstrates the conceptual framework of the current study. This is a quantitative experimental design study that uses a combination of cognitive performance assessment and task-based fMRI block design to measure brain connectivity during learning and retrieval of the acquired information. Fifteen healthy young Malaysian adults in the age range of 18-30 years old who meet the inclusion criteria will be recruited via convenience sampling. Participants will be in one group performing two categories of tasks namely familiar (Chinese) and unfamiliar (Arabic) with two conditions each (single-digit and double-digit). A 3-Tesla MRI Philips Achieva (Philips Medical Systems, Best, Netherlands) scanner with a 32-channel SENSE head coil will be used for data acquisition.&#x0D; Descriptive statistics will be used to summarise the socio-demographic characteristics of subjects. The mean difference in reaction time and accuracy of answers for single and double-digit in familiar and unfamiliar numerals will be analysed using two-way repeated-measures ANOVA and reported. The pre-processing of the fMRI images will be carried out using MATLAB software, Statistical Parametric Mapping 12, and CONN toolbox. The identification and comparison of the brain's functional connectivity will be done using the GIFT toolbox and Statistical Parametric Mapping 12. Results will be reported in the form of figures and tables.&#x0D; &#x0D; Both familiar and unfamiliar numerals are expected to activate the fronto-parietal-occipital networks by extracting the network from the cognitive-control domain, sub-cortical domain, and visual domain but with different connectivity values. Unfamiliar numerals are anticipated to have higher connectivity values than familiar numerals. Similar findings are expected to double and single digits, whereby higher connectivity values in double digits than in the single digits. The limited studies on functional connectivity show the main regions involved in mathematic processing are the inferior frontal gyrus (IPG), intraparietal sulcus (IPS), and inferior temporal gyrus (ITG) [4]. The outcome of this study would be beneficial as it could provide baseline data to investigate abnormalities of brain connectivity in learning and memory-related to numerical cognition among the young adult population.&#x0D;

Prognostic impact of right ventricular strain in isolated severe tricuspid regurgitation

Abstract Background Right ventricular (RV) systolic function is determinant in the evaluation of patients with severe tricuspid regurgitation (TR). Timely detection of RV dysfunction with conventional 2D echocardiography is challenging. RV strain has emerged as an accurate and sensitive tool for evaluation of RV function with the capability of detecting subclinical RV dysfunction. Purpose This study was aimed to evaluate the prognostic value of RV strain parameters in consecutive stable patients with severe TR. Methods Consecutive patients in stable clinical status with at least severe TR (severe, massive or torrential TR) evaluated in the Heart Valve Clinic following a comprehensive clinical protocol were included. Patients with previous episodes of heart failure or scheduled for TV intervention were excluded. RV systolic function was measured with conventional echocardiographic indices (RV fractional area change [FAC], tricuspid annular plane systolic excursion [TAPSE], DTI S wave [`S]) and with Speckle-tracking echocardiography (STE) derived automatic peak global and free wall longitudinal strain (RV-GLS and RV-FWLS respectively) using the EPIQ system (Philips Medical Systems, Andover, Massachusetts). A combined endpoint of hospital admission due to heart failure (HF) or all-cause mortality was defined. The interobserver variability of RV strain was assessed in 20 randomly selected patients. Results A total of 176 patients were included in this study. Strain parameters detected higher percentage of RV dysfunction compared to conventional indices (figure 1). After a median follow-up of 28 months (IQR: 15–48 months), n=65 patients (37%) reached the combined endpoint. 65 (37%) were admitted for right heart failure and 8% of the population (n=14) died. Cumulative event-free survival was significantly worse in patients with impaired RV-GLS and RV-FWLS. Conventional indices of RV systolic function were not associated with outcomes (p&amp;gt;0.05 for all). In a multivariable analysis (in a model including NYHA class, BNP values, biplane VC, RV end-diastolic area, and RV-FWLS), RV-FWLS was an independent predictors of heart failure and CV mortality (figure 1 and 2; LR χ2: 40.2, p&amp;lt;0.001). Inter-observer agreements for RV strain values were high (intraclass correlation coefficient for RV-GLS and RV-FWLS, r=0.96 and r=0.98 respectively) Conclusion Clinical outcomes demonstrate that RV strain parameters are superior to conventional indices of RV function in patients with isolated ≥ severe TR and absence of previous episodes of heart failure. Among all parameters of RV function, RV-FWLS is the strongest independent predictor of mortality and HF. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto Carlos III