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Background: Split kidney function (SKF) is critical for treatment decision in pediatric patients with hydronephrosis and is commonly measured using renal scintigraphy (RS). Non-contrast-enhanced magnetic resonance urography (NCE-MRU) is increasingly used in clinical practice. This study aimed to investigate the feasibility of using NCE-MRU as an alternative to estimate SKF in pediatric patients with hydronephrosis, compared to RS. Methods: Seventy-five pediatric patients with hydronephrosis were included in this retrospective study. All patients underwent NCE-MRU and RS within 2 weeks. Kidney parenchyma volume (KPV) and texture analysis parameters were obtained from T2-weighted (T2WI) in NCE-MRU. The calculated split KPV (SKPV) percent and texture analysis parameters percent of left kidney were compared with the RS-determined SKF. Results: SKPV showed a significant positive correlation with SKF (r = 0.88, p < 0.001), while inhomogeneity was negatively correlated with SKF (r = − 0.68, p < 0.001). The uncorrected and corrected prediction models of SKF were established using simple and multiple linear regression. Bland–Altman plots demonstrated good agreement of both predictive models. The residual sum of squares of the corrected prediction model was lower than that of the uncorrected model (0.283 vs. 0.314) but not statistically significant (p = 0.662). Subgroup analysis based on different MR machines showed correlation coefficients of 0.85, 0.95, and 0.94 between SKF and SKPV for three different scanners, respectively (p < 0.05 for all). Conclusions: NCE-MRU can be used as an alternative method for estimating SKF in pediatric patients with hydronephrosis when comparing with RS. Specifically, SKPV proves to be a simple and universally applicable indicator for predicting SKF. [ABSTRACT FROM AUTHOR]

Background: Conventionally, diuretic isotope renogram is used to establish and quantify severity of the obstruction in pelvi-ureteric junction obstruction. Doppler ultrasonography too assesses obstruction by evaluating the resistive index (RI) and resistive index ratio (RIR) in the intrarenal vasculature of the kidneys. This study aimed to note correlation between RI, RIR on Doppler ultrasonography and perfusion index (PI) on diuretic isotope renogram in suspect unilateral pelvi-ureteric junction obstruction in infants. A prospective study (2016–2019) in infants with suspect unilateral hydronephrosis, i.e. anteroposterior pelvic diameter (APPD) > 15 mm, divided into Group A (0–6 months) and Group B (6–12 months) based on the age at diagnosis. The RI, RIR and PI were noted at diagnosis, at 3 and 6 months, post-interventions and the correlation assessed. Results: 37/94 with hydronephrosis were included in the study. 30 among these underwent surgical intervention. A decrease in RI and RIR and increase in PI following surgery were documented at follow-up. Also, the improvement was statistically more significant in the first 3 months following intervention. Conclusions: An increased RI and RIR and a decreased PI are good indicators of obstruction in unilateral hydronephrosis in infants. The decline in RI with increase in PI following relief of obstruction shows a positive correlation between the two. Doppler sonography may be effective in monitoring unilateral hydronephrosis with unobstructed or equivocal renogram curves and consequently negate the need for repeated nuclear scans. [ABSTRACT FROM AUTHOR]

Background and Aim: Kidney dysfunction is reported in significant number of beta thalassemia major children. The aim of this study was to determine the prevalence of glomerular dysfunction in beta-thalassemia major children on regular blood transfusion (BT) and chelation therapy, and to find the correlation between glomerular filtration rate (GFR) estimated by Schwartz formula and Technetium 99m diethylenetriaminepentaacetic acid (99mTc-DTPA) renogram with ferritin level and cumulative transfusion load. Materials and Methods: An observational cross-sectional study conducted was done on 110 children diagnosed with beta-thalassemia major receiving regular BT and chelation therapy. Clinical examination, biochemical investigations (serum creatinine, ferritin) and DTPA renal scan were done. Estimated GFR calculation was done by Schwartz method and 99mTc-DTPA scan. The normal values of GFR were taken from the standard value as per KDIGO guidelines. P < 0.05 was considered statistically significant. Results: The prevalence of glomerular dysfunction by Schwartz formula and DTPA renogram was 44% and 24%, respectively. The GFR calculation (Schwartz formula and DTPA renogram) were weakly positively correlated (r = 0.126, P = 0.547). There was significant association between GFR Schwartz and duration of iron chelation, as children with abnormal GFR had significantly more duration of iron chelation >5 years (28% vs. 4%, P = 0.003). GFR (Schwartz formula and DTPA renogram) showed no association with cumulative transfusion load and disease duration (P > 0.05). GFR Schwartz formula and GFR-DTPA showed no correlation with serum ferritin with r = 0.179, (P = 0.392) and r = 0.278 (P = 0.178). Conclusion: There is a significant derangement in the renal function of children of beta-thalassemia major on chronic BT and iron chelation therapy. GFR holds a direct correlation with the increasing duration of iron chelation. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate diagnostic accuracy for active Takayasu arteritis (TAK) for two novel 18F-fluorodeoxyglucose PET-CT parameters, the inflammatory volume (MIV) and total inflammatory glycolysis (TIG), to quantitate volume of metabolically-active arterial tissue. Methods: From a cohort of TAK (n = 36, 35 immunosuppressive-naïve), images of PET-CTs were reviewed for mean and maximum standardized uptake value (SUVmean and SUVmax), target-to-blood pool ratio (TBR), target-to-liver ratio (TLR), and PET Vasculitis Activity Score (PETVAS). Regions of interest were drawn to semiautomatically calculate MIV in areas of 18F-fluorodeoxyglucose uptake ≥ 1.5 SUVmean after excluding physiological tracer uptake. TIG was calculated by multiplying MIV with SUVmean. PET-CT parameters, ESR, CRP, and clinical disease activity scores were compared against the gold standard of physician global assessment of disease activity (PGA, active/inactive). Results: Using dichotomized cut-offs for active TAK at SUVmax (≥ 2.21), SUVmean (≥ 1.58), TBR (≥ 2.31), TLR (≥ 1.22), PETVAS (various cut-offs), ESR (≥ 40 mm/hour), and CRP (≥ 6 mg/L), the novel indices MIV (≥ 1.8) and TIG (≥ 2.7) performed similar [area under the receiver operating characteristics curve (AUC) 0.873 for both] to SUVmax (AUC 0.841) and SUVmean (AUC 0.851), and better than TBR (AUC 0.773), TLR (AUC 0.773), PETVAS [≥ 5.5 (AUC 0.750), ≥ 10 (AUC 0.636), ≥ 15 (AUC 0.546)], ESR (AUC 0.748), or CRP (AUC 0.731). MIV and TIG had similar agreement with PGA or CRP as with SUVmax or SUVmean, and better agreement than TBR, TLR, or PETVAS cut-offs. Conclusions: MIV and TIG performed similarly, therefore, are viable alternatives to existing PET-CT parameters to assess TAK disease activity in this preliminary report. Key Points • MIV and TIG performed similar to SUVmax and SUVmax for disease activity assessment in TAK. • MIV and TIG distinguished active TAK better than TBR, TLR, PETVAS cut-offs, ESR, or CRP. • MIV and TIG had better agreement with PGA or CRP than TBR, TLR, or PETVAS cut-offs. [ABSTRACT FROM AUTHOR]

The main objective of the current study is to determine the distributions of the specific radioactivity concentrations (226Ra, 232Th and 40K) from terrestrial sources using gamma spectroscopy system (HPGe-detector). Forty (40) agricultural soil samples were collected from Wadi Al-Hussini and Tuban in Yemen. The study locations are famous for exporting coffee all over the world. The average of radio-concentrations of 226Ra, 232Th and 40K were 61.95±11.57, 32.33±8.03 and 1045.17±153.47 Bq/kg for Wadi Al-Hussini and 65.20±11.59, 50.95±9.80 and 1078.13±157.57 Bq/kg for Tuban, respectively. The obtained results are higher than the average worldwide values reported by UNSCEAR. So, it is not acceptable with global safe criteria. Also, the radiation hazard parameters such as radium equivalent activity, absorbed gamma dose rate, outdoor and indoor annual effective dose equivalent, external and internal radiation hazard index, gamma index level, annual gonadal dose equivalent and excess lifetime cancer risk. All of these parameters are acceptable and within the worldwide values. The obtained results could be considered as reference data to follow up any changes in the future for natural radionuclides pollutants and their risks in the study area. [ABSTRACT FROM AUTHOR]

Background: A growing body of evidence has demonstrated the utility and reliability of 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) diuretic renography in a wide range of renal disorders. Methods: In this retrospective study, we retrieved the medical records of patients who were referred to the Radiology Department of King Abdulaziz Specialist Hospital, Taif, Saudi Arabia due to suspected renal disease and were scheduled to undergo 99mTc-MAG3 diuretic renography during the period from January 2020 to November 2021. Results: The medical records of 280 patients were retrieved. Most of the patients had either suspected obstructive (n = 80; 30.7 %) or non-obstructive hydronephrosis (n = 60; 23.1 %). The left kidney was affected in more than half of the patients (n = 155; 59.6 %). In terms of split kidney functions, the right kidney had a median function of 50.9 (38.5-75.5); overall, 39 (69.6%) had good right kidney function. The left kidney had a median function of 49.4 (24.5-61.5); overall, 33 (58.9%) had good left kidney function. Conclusion: Radioisotope renography is a useful tool for assessing renal functions in real-life settings. The technique provides a safe and easy-to-use tool that can guide the management approaches of patients presenting with renal diseases. It can reduce the interval from presentation to definitive diagnosis and ensure the prompt initiation of therapy after diagnosis. The present study's results indicated that radioisotope renography was useful in providing reference values and visual interpretation of impaired renal function, obstructive uropathy, renal stenosis, and acute tubular necrosis. Nonetheless, as the current literature reveals a significant impact of operator experience on the reliability of radioisotope renography, regular reader training is encouraged. [ABSTRACT FROM AUTHOR]

Background. The first-pass (FP) effect, defined by successful cerebral reperfusion from a single pass of an endovascular stentriever, was associated with shorter procedural times and possible improved outcomes in patients with ischemic stroke secondary to large vessel occlusion. The adjunctive use of balloon guide catheter (BGC) may increase the rates of the first-pass effect. In this retrospective study we examined the impact of BGC on the first-pass effect in acute stroke patients. Methods. We included patients with acute ischemic stroke with large vessel occlusion treated by endovascular thrombectomy from 2018 to 2019. We categorized the cases into BGC and non-BGC groups. Differences in time metrics and outcomes were compared. Result. One hundred and thirty-two patients were included, and sixty-two were in BGC group (47.0%). The median procedural time was shorter (83.0 minutes vs 120.0 minutes, P = 0.000), and FP rate was higher in BGC group (58.1% vs 32.9%, P = 0.004) compared with non-BGC group. Proportion of modified Thrombolysis in Cerebral Infarction (mMTICI) 3 was higher (66.1% vs 37.1%, P = 0.001), and modified Rankin Scale (mRS) 0 to 2 was higher (59.7% vs 41.4%, P = 0.036) in BGC group compared with non-BGC group. In addition, BGC was associated with successful reperfusion odds ratio, 0.383; 95% confidence interval: 0.174-0.847; P = 0.018). The FP rate of BGC in the distal ICA was higher than that in the proximal ICA (87.5% vs 39.5%, P = 0.000), and the good clinical outcome rate at 90 days in the distal ICA was also higher than that in the proximal ICA (91.7% vs 39.5%, P = 0.000). Conclusion. We showed that BGC shortened the procedural time and increased the rate of the successful FP. We recommend that BGC could be considered the preferred technique for endovascular intervention in stroke. [ABSTRACT FROM AUTHOR]

Background: Both the development of kidney function in healthy children and autoregulation ability of kidney function in patients with asymmetric kidneys are important in clinical diagnosis and treatment of kidney-related diseases, but there are however only limited studies. This study aimed to investigate development of kidney function in normal children with healthy symmetric kidneys and autoregulation of the healthy kidney compensating the functional loss of a diseased one in children with asymmetric kidneys. Methods: Two hundred thirty-seven children (156 male, 81 female) from 0 to 20y (average 4.6y ± 5.1) undergoing 99mTc-MAG3 renography were included, comprising 134 with healthy symmetrically functioning kidneys and 103 with asymmetric kidneys. Clearance was calculated from kidney uptakes at 1–2 min. A developmental model between MAG3 clearance (CL) and patient age in normal group was identified (CL = 84.39Age0.395 ml/min, r = 0.957, p < 0.001). The clearance autoregulation rate in abnormal group with asymmetric kidneys was defined as the ratio of the measured MAG3 clearance and the normal value predicted from the renal developmental model of normal group. Results: No significant difference of MAG3 clearance (p = 0.723) was found between independent abnormal group and normal group. The autoregulation rate of kidney clearance in abnormal group was 94.2% on average, and no significant differences were found between two age groups (p = 0.49), male and female (p = 0.39), and left kidney and right kidney (p = 0.92) but two different grades of asymmetric kidneys (p = 0.02). Conclusions: The healthy kidney of two asymmetric kidneys can automatically regulate total kidney function up to 94% of two symmetric kidneys in normal children. [ABSTRACT FROM AUTHOR]

Anthracycline induced cardiotoxicity is well recognized but only few data exist in sarcoma patients. This study retrospectively aimed to analyze sequential Cadmium Zinc Telluride (CZT)-multigated equilibrium radionuclide angiography (ERNA) for monitoring left ventricular ejection fraction (LVEF) and to assess the real-life incidence of cardiotoxicity in sarcoma patients receiving doxorubicin based chemotherapy. A retrospective analysis was performed on all sarcoma patients referred to Herlev University Hospital between 2012 and 2015. Cardiotoxicity was defined as a decline in LVEF of > 10% percentage point to a LVEF < 50% as compared to baseline. Early cardiotoxicity was defined as < 1 year and late cardiotoxicity as ≥ 1 year. Recovery of cardiotoxicity was defined as a LVEF ≥ 50%. A total of 149 patients were referred, 75 (50%) sarcoma patients were included. The main reason for exclusion was that only one CZT-ERNA had been performed in 50 (68%) of the patients. Twenty-three (31%) of the patients experienced cardiotoxicity, 11 (48%) were female, mean age was 56.9 years. Early cardiotoxicity was observed in 16 (70%) of the patients and 11 (48%) experienced clinical symptoms of cardiotoxicity at diagnosis. Recovery of LVEF was seen in 12 (55%) of the patients and persistent recovery in 10 (45%). The diastolic blood pressure at baseline was positively and significantly associated with a higher risk of developing cardiotoxicity (Relative Risk (RR): 1.039 (95% CI= 1.001 − 1.079; p = 0.042)). The median survival was 1.4 years (range 0.5 − 2.2 years) for patients with metastatic disease versus 3.9 years (range 1.5 − 6.4 years) (p = 0.009) for localized disease at baseline. Cardiotoxicity is a relative frequent complication in sarcoma patients treated with doxorubicin based chemotherapy and the diastolic blood pressure at baseline was significantly associated with a higher risk of developing cardiotoxicity. [ABSTRACT FROM AUTHOR]

Introduction: In infants with suspected pelviureteric junction (PUJ) like obstruction, we compared the drainage patterns suggested by t 1/2 and normalized residual activity (NORA) to determine which parameter can differentiate obstructive from nonobstructive dilatation and thus predict the need for surgery. Materials and Methods: Infants presenting with prenatally detected PUJ-like obstruction from January 2014 to March 2020 were evaluated with ultrasonography. Diuretic renogram was performed using Tc99m ethylene dicysteine using the F0 protocol. Subjects with a differential renal function >40% were included in the study. The t ½ values were noted. NORA was calculated by dividing the tracer values at 60 min with the values at 2 min. The infants were followed using ultrasonography. Renogram was repeated if there was increase in hydronephrosis or after 6 months if hydronephrosis did not regress. The follow-up was continued till a decision for pyeloplasty was made or the hydronephrosis regressed. Pyeloplasty was advised if differential function dropped to below 40%. Results: 34 patients met the inclusion criteria. NORA and t ½ had very poor concordance in defining the drainage pattern. t ½ values did not correlate with the need for surgery or conservative management (P ≥ 0.05). Good drainage pattern by NORA was associated with regression of hydronephrosis (P ≤ 0.001). NORA predicted obstruction more accurately. Conclusion: NORA can define good drainage in a much larger subset of patients with PUJ-like obstruction who eventually do not need surgery. However, further multicenter studies are needed to confirm this. [ABSTRACT FROM AUTHOR]

Aim: To determine the efficacy and outcome of pyeloplasty in poorly functioning kidneys in the pediatric population and whether pyeloplasty could be offered as an upfront procedure in such patient population, instead of nephrectomy. Materials and Methods: A retrospective data analysis of 83 patients who underwent pyeloplasty in poorly functioning kidneys from 2010 to 2015 was performed. Success was defined based on improvement in symptoms, stable or improved function, and better drainage on post-operative Tc-99m Diethylene Triamine Pentaacetic acid scan instead of DTPA scan renography done after 3 months and yearly thereafter. Results: Eighty-three patients with a mean age of 6.8 ± 2.88 years with poor function on isotope renogram (<30%) were included in the study. Three patients were excluded in view of postoperative outflow obstruction. Out of the remaining 80 patients, 56 were male and 24 were female. They were divided into two groups based on preoperative differential renal function (DRF), Group I (n = 26) having preoperative DRF of <10% and Group II (n = 54) having preoperative DRF of 10%–30%. All patients underwent laparoscopic dismembered pyeloplasty with ureteral stenting. The mean DRF improved from 7.58 ± 2.39 to 29.71 ± 5.16 postoperatively in Group I. However, in Group II, DRF improved from 20.81 ± 5.68 to 37.25 ± 7.11 postoperatively. At a follow-up of 24 months, the overall success rate was 98%. Conclusion: Pyeloplasty gives good intermediate-term results even in extremely poorly functioning kidneys and an upfront pyeloplasty instead of nephrectomy should be offered to all pediatric patients irrespective of preoperative function. [ABSTRACT FROM AUTHOR]

BackgroundArrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable arrhythmia syndrome entailing a high risk of sudden cardiac death. Discernment from benign arrhythmia disorders, particularly right ventricular outflow tract ventricular tachycardia (RVOT VT), may be challenging, providing an impetus to explore alternative modalities that may facilitate evaluation of patients with suspected ARVC.ObjectiveWe evaluated the role of equilibrium radionuclide angiography (ERNA) as a diagnostic tool for ARVC.MethodsERNA measures of ventricular synchrony-synchrony (S) and entropy (E)-were examined in patients with ARVC (n = 16), those with RVOT VT (n = 13), and healthy controls (n = 49). The sensitivity and specificity of ERNA parameters for ARVC diagnosis were compared with those of echocardiography (ECHO) and cardiovascular magnetic resonance (CMR).ResultsERNA right ventricular synchrony parameters in patients with ARVC (S = 0.91 ± 0.07; E = 0.61 ± 0.1) differed significantly from those in patients with RVOT VT (S = 0.99 ± 0.01 [P = .0015]; E = 0.46 ± 0.05 [P < .001]) and healthy controls (S = 0.97 ± 0.02 [P = .003]; E = 0.48 ± 0.07 [P = .001]). The sensitivity of ERNA synchrony parameters for ARVC diagnosis (81%) was higher than that for ECHO (38%; P = .033) and similar to that for CMR (69%; P = .162), while specificity was lower for ERNA (89%) than that for ECHO and CMR (both 100%; P = .008).ConclusionERNA right ventricular synchrony parameters can distinguish patients with ARVC from controls with structurally normal hearts, and its performance is comparable to that of ECHO and CMR for ARVC diagnosis. These findings suggest that ERNA may serve as a valuable imaging tool in the diagnostic evaluation of patients with suspected ARVC.

Introduction: Differentiating nonobstructive from obstructive dilatation of the kidney is a clinical dilemma in prenatally detected hydronephrosis. Many radionuclide renogram parameters have been used to differentiate obstructed from non-obstructed units, including cortical transit time (CTT). We evaluate the role of CTT in identifying obstruction through a systematic review. Methods: A literature search of the MEDLINE, MEDLINE In-Process, and MEDLINE Epub Ahead of Print, EMBASE, Google scholar, Pub Med, and Cochrane Library was done using key words -- radionuclide renogram, CTT, parenchymal transit time, cortical transit, renography to identify articles on the subject. The identified articles were assessed for appropriateness and reviewed. Results: The initial search yielded a total of 1583 articles, after adding the articles from references and applying the inclusion and exclusion criteria a total of 28 articles were selected. CTT showed good inter observer agreement in identifying obstruction. The use of CTT as a single parameter for determining the need for surgery and to identify those kidneys which will have functional improvement after surgery has been evaluated and has been found to be useful. CTT is best used in conjunction with ultrasonography to make clinical decisions. Conclusion: The commonly used visual method of estimating the CTT, is a promising parameter for the evaluation of prenatally detected pelviureteric junction obstruction. Further well-designed multicenter prospective studies are needed to establish it as the most specific parameter to differentiate obstructive from nonobstructive dilatation of the pelvicalyceal system. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary artery hypertension and its consequences still constitutes an underestimated clinical problem in asthma patients and its non-invasive early detection may influence proper treatment. Aim: To non-invasively examine the pulmonary artery flow parameters and right ventricular function in patients with asthma of various severity. Material and methods: The analysis of parameters of echocardiography and first-pass and gated radionuclide angiography, and baseline examination in 31 patients with bronchial asthma and 16 healthy controls. Results: Patients with severe asthma had higher mean pulmonary artery pressure (MPAP) compared to the healthy controls. The subgroup analysis of patients who suffered from asthma in their childhood showed that individuals with severe asthma were characterized by significantly higher MPAP than those with the mild/moderate condition (19.16 ±7.51 mm Hg vs. 5.0 ±1.15 mm Hg, p = 0.025). Gated, but not first-pass, radionuclide angiography revealed that individuals with severe asthma were characterized by a lower right ventricular ejection fraction (RVEF). Further analysis of the subgroup of patients in whom the initial manifestation of dyspnoea occurred no earlier than 6 years prior to the study showed that the RVEF of individuals with severe asthma was significantly lower compared to those with mild/moderate asthma (39.8 ±4.79% vs. 51.4 ±8.65%, p = 0.019). Conclusions: The pulmonary artery pressure in patients with severe asthma is significantly higher than in healthy individuals; in contrast, these two groups did not differ significantly in terms of the right ventricular echocardiographic characteristics. Gated radionuclide angiography, but not the first-pass technique, allowed for the detection of subtle right ventricular ejection fraction changes in asthma patients. [ABSTRACT FROM AUTHOR]

Background: Simpson biplane method and 3D by transthoracic echocardiography (TTE), radionuclide angiography (RNA) and cardiac magnetic resonance imaging (CMR) are the most accepted techniques for left ventricular ejection fraction (LVEF) assessment. Wall motion score index (WMSI) by TTE is an accepted complement. However, the conversion from WMSI to LVEF is obtained through a regression equation, which may limit its use. In this retrospective study, we aimed to validate a new method to derive LVEF from the wall motion score in 95 patients. Methods: The new score consisted of attributing a segmental EF to each LV segment based on the wall motion score and averaging all 16 segmental EF into a global LVEF. This segmental EF score was calculated on TTE in 95 patients, and RNA was used as the reference LVEF method. LVEF using the new segmental EF 15-40-65 score on TTE was compared to the reference methods using linear regression and Bland–Altman analyses. Results: The median LVEF was 45% (interquartile range 32–53%; range from 15 to 65%). Our new segmental EF 15-40-65 score derived on TTE correlated strongly with RNA-LVEF (r = 0.97). Overall, the new score resulted in good agreement of LVEF compared to RNA (mean bias 0.61%). The standard deviations (s.d.s) of the distributions of inter-method difference for the comparison of the new score with RNA were 6.2%, indicating good precision. Conclusion: LVEF assessment using segmental EF derived from the wall motion score applied to each of the 16 LV segments has excellent correlation and agreement with a reference method.

Given their ephemeral nature, eddies have proven difficult to study, with contrary results from field observations that typically sample at the center during a specific stage of an eddy lifespan. Using the natural occurring radionuclide 234Th, we examined particle fluxes within two cyclonic eddies (CEs) at different evolutionary stages (mature stage eddy, C2, and a decay stage eddy, C1) in the oligotrophic western South China Sea (SCS). Using a 1‐D steady state model, 234Th derived particulate organic carbon (POC) and opal fluxes at 100 m were determined. Both POC and opal fluxes were significantly higher at the eddy edges relative to the eddy cores, with integrated eddy POC and opal fluxes of 6.2 (2.1) mmol C m−2 day−1 and 1.5 (0.28) mmol Si m−2 day−1 in C2 (C1). When compared to non‐eddy regimes, both POC (by 2.6‐fold) and opal fluxes (by 7.5‐fold) in C2 were enhanced; they were reduced and decoupled (0.9‐fold and 1.4‐fold) in C1. The difference in enhancement of particle fluxes and the coupling/decoupling between POC and opal flux likely reflects changes in phytoplankton community structures resulting from eddy evolution. Scaling these results to the entire SCS basin suggests that CEs contribute <4% of the net POC flux but >15% of the opal flux. Therefore, CEs may regulate the biogeochemical cycling of silica to a much greater extent than carbon in the ocean. Key Points: Carbon and opal export are concentrated at the edges of eddies and during their "mature" stageCarbon and opal export wane and become decoupled as the eddies decayMesoscale features disproportionately impact opal export relative to carbon export [ABSTRACT FROM AUTHOR]

Copyright of Der Onkologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: We analyzed the influence of anesthesia methods on surgical outcomes and renal function in retrograde intrarenal surgery (RIRS) in a prospective, randomized controlled study. Methods: Seventy patients who underwent RIRS from September 2015 to February 2017 were randomly allocated to general anesthesia (GA) or spinal anesthesia (SA) groups. Renal function was assessed using estimated glomerular filtration rate, and separate renal function was evaluated using nuclear medicine tests. Maneuverability and accessibility were evaluated after every surgery. All procedures were performed by a single experienced surgeon (SY Cho). Results: Stone-free rate was higher in the GA (92.3%, 36 of 39) than the SA (71.0%, 22 of 31) (P = 0.019) group. Pain score was higher in the GA than in the SA group on the first postoperative morning (P = 0.025), but pain scores of the two groups were similar before discharge (P = 0.560). There were no differences in the changes of serum creatinine level (P = 0.792) and changes of estimated glomerular filtration rate (P = 0.807). Differences of separate renal function between operative and contralateral site increased significantly in patients under GA than under SA at postoperative 3 months (P = 0.014). Maneuverability and accessibility were better in SA with sedation than GA (P < 0.001). Conclusions: RIRS under SA showed advantages in renal function change using renogram at postoperative 3 months and in lower pain score on the first postoperative morning. Performance of operator under SA was worse than that under GA and significantly improved with sedation. RIRS under SA showed advantages in lower pain score at postoperative first day. Trial registration: Clinicaltrials.gov ID is NCT03957109, and registration date is 17th May 2019. This study was retrospectively registered. [ABSTRACT FROM AUTHOR]

Background: IQ-SPECT has been shown to significantly reduce acquisition time and administered dose while preserving image quality in myocardial perfusion imaging. Whether IQ-SPECT provides accurate left ventricular ejection fractions (LVEF) with gated blood pool SPECT (GBPS) remains unknown.Methods: Sixty patients underwent IQ-SPECT GBPS and planar imaging. Among those patients, 11 underwent both cMRI and GBPS. GBPS LVEF, LVEDV, and LVESV were calculated using 2 validated software; QBS (Cedars-Sinai Medical Center, Los Angeles, USA) and MHI (Montreal Heart Institute, Montreal, Canada). LVEF, LVEDV, and LVESV obtained with the different modalities were compared.Results: Average planar LVEF was 48 ± 11% (mean ± SD), average LVEDV was 177 ± 59 mL (range 63 to 342 mL), and average LVESV was 96 ± 46 mL (range 16 to 234 mL). GBPS LVEF and their correlation coefficient with planar LVEF were 40 ± 12% (r = 0.70) and 44 ± 12% (r = 0.83) with QBS and MHI, respectively. Correlation coefficient between cMRI and planar LVEF was 0.65 and were 0.69 and 0.52 between cMRI and GBPS using QBS and MHI, respectively.Conclusions: LVEF calculated with GBPS using IQ-SPECT correlates with planar measurements. Correlation is best using the MHI method and variation is independent of LVEDV. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Nuclear Cardiology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To assess the effect of the duration of fever after the initiation of treatment (FAT) of febrile urinary tract infections (UTI) on the development of permanent renal lesions based on dimercaptosuccinic acid (DMSA) scintigraphy findings. To evaluate the FAT contribution to permanent renal lesion formation in relation to fever before treatment initiation (FBT), the presence of vesicourinary reflux (VUR), age and severity of infection.Methods: The inpatient records of 148 children (median age: 2.4 months (11 days to 24 months)) with a first episode of UTI during a 3-year period were analysed. DMSA findings, and clinical and laboratory parameters were evaluated.Results: Among the study population, 34/148 (22.97%) children had permanent renal lesions on the DMSA scan 6 months after a single episode of UTI. Twenty-three children (15.5%) had mild, 10 (6.7%) had moderate and 1 (0.6%) child had severe lesions on the DMSA. FAT prolongation >/48 hours was associated with older age (p=0.01) and increased absolute neutrophil count (p=0.042). The likelihood of lesions was significantly increased when FAT was ≥48 hours (R2=0.043, p=0.021). On multiple regression analysis, with the addition of FBT>/72 hours (0.022), the presence of VUR (p<0.001), C-reactive protein (p=0.027) and age (p=0.031), the effect of FAT on lesion development disappeared (p=0.15).Conclusions: Prolongation of FAT≥48 hours of febrile UTI in children <2 years significantly contributes to the development of permanent renal lesions. However, delay in treatment initiation >/72 hours, the presence of VUR, older age and infection severity seem to be more significant predictors of the development of renal lesions. [ABSTRACT FROM AUTHOR]

Abstract More than 10,000 whole organism concentration ratio (CR wo-water) values for freshwater wildlife were derived from radionuclide and stable element data representing an Australian tropical U mining environment. The CR wo-water values were summarised into five wildlife groups (bird, fish, mollusc, reptile and vascular plant). The summarised CR wo-water values represented 77 organism-element combinations. The CR wo-water values for U decay series elements were used in a tier 3 ERICA assessment. The assessment results were used to derive a water radiological quality guideline value (GV) for radiation protection of freshwater ecosystems in the context of the planned remediation of the Ranger U mine. The GV was an above-background water 226Ra activity concentration of 14 mBq L−1 (filtered fraction) or approximately 22 mBq L−1 (total fraction). The GV was based on the results of mollusc-bivalve as the limiting organism for the freshwater ecosystem. Highlights • More than 10,000 CR wo-water values for freshwater organisms were derived. • Summarised CR wo-water values represented 77 organism-element combinations. • A water quality guideline value was derived for a U mine remediation scenario. • A water 226Ra concentration of 14 mBq L−1 protects tropical freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Aim: We carried out this study to investigate mid-term effects of cardiac resynchronization therapy (CRT) on right ventricular (RV) function and neurohormonal response, expressed by N-terminal pro-brain natriuretic peptide (NT-proBNP), in heart failure patients stratified by baseline RV ejection fraction (RVEF).Methods and Results: Thirty-six patients with nonischemic dilated cardiomyopathy underwent technetium-99m radionuclide angiography with bicycle exercise immediately after CRT implantation (during spontaneous rhythm and after CRT activation) and 3 months later. Plasma NT proBNP was assessed before implantation and after 3 months. At baseline, RVEF was impaired (≤35%) in 14 patients, preserved (>35%) in 22. At 3 months, RVEF improved during rest and exercise (P = .02) in patients with impaired RV function, while remaining unchanged in patients with preserved RV function. Rest and exercise RV dyssynchrony decreased in both groups at follow-up (P < .05). A similar mid-term improvement in left ventricular (LV) function and NT-proBNP was observed in patients with impaired and preserved RVEF. In the former, the decrease in NT-proBNP correlated with the improvements both in LV and RV dyssynchrony and functions.Conclusion: CRT may improve RV performance, during rest and exercise, and neurohormonal response in heart failure patients with nonischemic dilated cardiomyopathy and baseline RV dysfunction. RV dysfunction should not be considered per se a primary criterion for excluding candidacy to CRT. [ABSTRACT FROM AUTHOR]

Cancer therapy-induced cardiotoxicity is an emerging clinical and healthcare issue. Myocardial dysfunction and heart failure are mostly responsible for increased cardiovascular mortality in cancer disease survivors. Several imaging surveillance techniques have been proposed for early diagnosis of cancer therapy-induced cardiac dysfunction. Our aim was to provide an update of radionuclide angiography applications in this field. Radionuclide angiography is widely used to assess left ventricular ejection fraction (LVEF) throughout cancer treatment, especially in patients with limited acoustic window. Additional prognostic data may be provided by phase analysis and diastolic function evaluation. Low LVEF and high approximate entropy at baseline seem to be predictors for cancer therapy-induced cardiac dysfunction. A decrease in peak filling rate and/or an increase in time to peak filling rate may be observed in patients undergoing anthracycline and/or trastuzumab administration. Diastolic function impairment may precede or not LVEF decrease. In conclusion, recent studies have provided novel insights into the possible role of radionuclide angiography in the early detection of cancer therapy cardiotoxicity. While interpreting the results of a radionuclide angiography examination, an integrated approach combining the evaluation of LVEF, LV diastolic function, and phase analysis may be useful to improve risk stratification of cancer patients treated with cardiotoxic agents., (© 2023. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.)

Background: We assess the potency of different Doppler indices in the differentiation of obstructive and nonobstructive hydronephrosis. Materials and Methods: In this study, infants and children who were referred for the evaluation of unilateral hydronephrosis were enrolled. Ultrasonography for the assessment of the degree of hydronephrosis and a voiding cystourethrogram for the exclusion of vesicoureteral reflux was performed. Then, Doppler ultrasonography was done for both kidneys of each patient using four classic Doppler indices as well as the difference (delta) of each index between to kidneys. Diuretic renography with 99 mTc-ethylene dicysteine (99 mTc-EC) was performed for each patient. Results: Thirty-nine patients met the inclusion criteria. After diuretic renography, 29 (74.35%) patients had shown a nonobstructive pattern, and ten (25.65%) patients had a partial (intermediate) or complete obstruction. Using receiver operating characteristic (ROC) curve, none of the classic indices of Doppler duplex (i.e., resistive index [RI], resistance index, end diastolic velocity, and peak systolic velocity) had the ability to make a difference between obstructive and nonobstructive hydronephrosis. However, by calculating the difference (delta) of these indices between two kidneys of each patient, delta RI could differentiate the nonobstructive condition, significantly (P = 0.006). A cutoff value of 0.055 has 60% sensitivity and 82.8% specificity. The area under the ROC curve for delta RI is 0.795 (standard error: 0.086, 95% confidence interval [CI]: 0.626, 0.964). Furthermore, RI ratio between two kidneys of each patient could differentiate the nonobstructive condition, significantly (P = 0.012). A cutoff point of 1.075 has 70% sensitivity and 82.8% specificity. The area under the ROC curve for RI ratio was 0.769 (standard error: 0.104, 95% CI: 0.565, 0.973). Conclusion: This study shows that RI ratio and delta RI with a high specificity could differentiate nonobstructive hydronephrosis and therefore it is a promising way to use especially in the follow-up of children with hydronephrosis. [ABSTRACT FROM AUTHOR]

Ureterocolic fistulae are a rare phenomenon and are most commonly seen secondary to obstructive ureteric calculi. These are usually diagnosed on barium enema or intravenous urography. Most of the times, more than one investigation is needed to confirm the findings. We present a case of iatrogenically-induced ureterocolic fistula, diagnosed on renogram and direct radionuclide cystography. This case showcases the possibility of using a renogram study as a diagnostic tool for a suspected ureterocolic fistula. A renogram study also enables to asess the renal function, which is essential in deciding the management. [ABSTRACT FROM AUTHOR]

BACKGROUND: Dynamic renal scintigraphy provides effective diagnosis of obstructive uropathy and nephropathy. However, in case of a bilateral outflow impairment, relative differential renal function (DRF), which is a primary quantitative criterion for diagnosis of unilateral obstructive nephropathy (when its value is below 45%, according to EANM guidelines from 2011), becomes unreliable. In case of bilateral nephropathy with similar severity, this parameter may even be within the normal range (45-55%) for both kidneys. The aim of this study was therefore to assess diagnostic usefulness of the original, normalized, absolute parameter proportional to the value of renal clearance function (K) in the evaluation of obstructive nephropathy in a group of patients with bilateral uropathy. MATERIAL AND METHODS: 16 healthy volunteers (32 kidneys) without history of kidney diseases were examined to determine normative value of K index. Then, 8 patients (16 kidneys) with bilateral obstructive uropathy found in standard dynamic renal scintigraphy performed using 111 MBq of 99mTc-EC (cumulative renographic curve that continued rising or dropped by less than 50% after i.v. administration of Furosemide) were examined. For each of the subjects 60 sequential 20s images were obtained, which were then assessed using an original method of post-processing scintigraphic data. It included normalization of renographic curves to the area under the heart curve. Subsequently, these normalized values from the uptake phase (between 2nd and 3rd minute) were inserted into the linear regression equation, from which K index was obtained. RESULTS: In healthy volunteers the average value of K index was 0.23 ± 0.05. The value of 0.13 (mean-2 SD) was taken as the lower limit of the norm. Values below that limit suggest obstructive nephropathy. In patients with bilateral obstructive uropathy, 5 kidneys met the conventional criteria of nephropathy (DRF < 45%), while 11 kidneys had DRF within normal range. K index was below the norm in 9 kidneys (including 4 kidneys with low and 5 with normal DRF), while its value was normal in 7, including one kidney with reduced DRF (37%). K index changed the diagnosis in 6 kidneys out of 16 (38%). CONCLUSIONS: Preliminary results indicate usefulness of K index in diagnosis of obstructive nephropathy in patients with bilateral obstructive uropathy. For further evaluation of clinical value of this method, it is planned to examine a larger group of patients with varying degrees of renal parenchymal function impairments. [ABSTRACT FROM AUTHOR]

Background A satisfactory bolus injection is essential for a successful first-pass radionuclide angiography (FPRNA). Rescheduling the FPRNA study is usually needed due to high background interference caused by an unsatisfactory bolus injection. We developed a protocol to correct the pre-existing background activity subsequent to immediately repeating the study. Methods Seventy-four consecutive patients who had their bone scan and FPRNA scheduled on the same day were included for analysis. The initial 51 cases constituted the “validation-only” group. In the other 23 cases, the “validation plus clearance constants” group, a 5-min dynamic acquisition was performed during the 5-min equilibrium to obtain the background clearance curve and the clearance constants. For all included 74 cases ejection fraction (EF) analysis was proceeded using the images from the first injection, second injection, and second injection with the corrected background to yield EF1, EF2, and EF2′, respectively. EF2 and EF2′ were then compared to the ejection fraction without background interference, the EF1. Results For the LV, the mean difference between the EF1 and the uncorrected EF2 (|LVEF1-LVEF2| in mean ± SD) was 3.1 ± 2.0% and the difference between the EF1 and the corrected EF2′ (|LVEF1-LVEF2′|) was 1.6 ± 2.1%, while the mean differences for RV are 2.2 ± 1.9% and 1.8 ± 1.8%, respectively. A significant difference ( p < 0.05) was observed between the uncorrected and the corrected data for both the LV and RV. Conclusion In FPRNA, when a bolus injection is immediately readministered, both LVEF and RVEF can be underestimated. With our correction method, the results are superior to those without correction. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate and compare the diagnostic accuracy of dynamic contrast-enhanced magnetic resonance imaging (dMRI) and isotope renogram in the functional evaluation of pelviureteric junction obstruction (PUJO). Material and methods: Forty-two patients included in the study were investigated with isotope renogram and subsequently, subjected to dMRI. Time-activity curves were generated for both isotope renogram and dMRI. Out of the 42 cases, 9 cases were conservatively managed. Thirty-three cases were taken up for surgical intervention. Results: Of 33 patients taken up for surgical intervention, 12 underwent laparoscopic nephrectomy and 21 of them pyeloplasty. The mean glomerular filtration rates (GFRs) as measured by isotope renogram and dMRI were 22.5+4.2 mL/min and 23.8+3.1 mL/min respectively. The calculation of GFR by isotope renogram, showed good correlation with that of dMRI with correlation coefficient of 0.93. The dMRI was able to reveal the functional status of the renal unit accurately. dMRI did not yield false positive results with 20 of 21 patients scheduled for pyeloplasty and 11 of 12 patients scheduled for nephrectomy. Isotope renogram had a false positive result in 3 cases compared with surgical diagnosis. Conclusion: Analysis of renal function using dMRI yielded results comparable to those of renal scintigraphy, with superior spatial and contrast resolution. It was also better in prompting management decisions with respect to the obstructed systems. dMRI can be used as a "one stop imaging examination" that can replace different imaging methods used for morphological, etiological and functional evaluation of PUJO. [ABSTRACT FROM AUTHOR]

Radionuclides in the Arctic echinoderms have seldom been studied despite their considerable environmental importance. This manuscript covers the results of 90 Sr and 137 Cs measurements in common echinoderm taxa collected from the Svalbard Bank in the Barents Sea and from two High-Arctic fjords (Isfjorden and Magdalenefjorden). We focused on the echinoid, Strongylocentrotus droebachiensis , the asteroid, Henricia sanguinolenta , and the ophiuroid, Ophiopolis aculeata . For all echinoderms, the analysis revealed a negative correlation between 90 Sr activity and the mass. Thus, we concluded that metals are accumulated faster at a young age when the growth is most rapid. The highest average activities of 137 Cs followed the order O . aculeata > H . sanguinolenta > S . droebachiensis . This suggests that bioaccumulation was highly taxon-dependent and could reflect differences in the isotope exposures associated with the diet of echinoderms. The study provides a baseline for understanding radionuclide processes in the High-Arctic benthic echinoderm communities. [ABSTRACT FROM AUTHOR]

Purpose As growing numbers of long-term cancer survivors faced with the cardiac side effects by anthracycline treatment, it is necessary to explore the optimal monitoring method for the early detection of cardiac toxicity. Methods We conducted a retrospective analysis of 82 consecutive patients with diffuse large B-cell lymphoma treated with chemotherapy. Echocardiographic Doppler imaging-derived Tei index and mitral annular peak systolic velocity (Sm) measured by tissue Doppler imaging TDI, serum high-sensitivity cardiac troponin T (hs- cTnT) levels, and left ventricular ejection fraction ( LVEF) by multigated radionuclide angiography ( MUGA) were obtained before, after 2-4, and after 6-8 chemotherapy cycles. Cardiotoxicity was defined as a relative reduction of LVEF ≥10% from the baseline or LVEF <50% as measured by MUGA. Results Following chemotherapy, 24 (29.3%) patients developed detectable cardiac abnormality during the treatment. Five (6.1%) patients' cardiac function changed from normal baseline LVEF to <50% after the chemotherapy. Echocardiographic pulse wave Doppler Tei index ( PW Tei index) (baseline 0.347 ± 0.115 vs 2-4 cycles 0.459 ± 0.161 vs 6-8 cycles 0.424 ± 0.139, P = .000) inversely correlated with systolic ( P < .001) and diastolic dysfunction ( P < .001). Serum hs- cTnT levels increased significantly following chemotherapy after 2-4 cycles of chemotherapy with anthracycline. The increase in PW Tei index of 0.095 [sensitivity, 69.2%; specificity, 64.5%; area under the curve ( AUC) = 0.697; P = .005] and the Sm < 13.65 cm/s (sensitivity, 66.7%; specificity, 71%; AUC = 0.682; P = .009) combined with elevation of serum hs- cTnT level of 0.0075 ng/mL (sensitivity, 69.2%; specificity, 83.9%; AUC = 0.790; P < .001) after 2-4 chemotherapy cycles from the baseline values can reliably predict cardiotoxicity. Conclusions We demonstrated that echocardiographic PW Doppler-derived Tei index, and TDI-derived Sm, combined with serum hs- cTnT level can be obtained in outpatient settings to monitor early cardiac toxicity induced by anthracycline therapy. [ABSTRACT FROM AUTHOR]

Background Right ventricular (RV) systolic function is a powerful prognostic factor in patients with systolic heart failure. The accurate estimation of RV function remains difficult. The aim of the study was to determine the diagnostic accuracy of 2D-speckle tracking RV strain in patients with systolic heart failure, analyzing both free and posterolateral walls. Methods Seventy-six patients with dilated cardiopathy (left ventricular end-diastolic volume ≥ 75 ml/m 2 ) and left ventricular ejection fraction ≤ 45% had an analysis of the RV strain. Feasibility, reproducibility and diagnostic accuracy of RV strain were analyzed and compared to other echocardiographic parameters of RV function. RV dysfunction was defined as a RV ejection fraction ≤ 40% measured by radionuclide angiography. Results RV strain feasibility was 93.9% for the free-wall and 79.8% for the posterolateral wall. RV strain reproducibility was good (intra-observer and inter-observer bias and limits of agreement of 0.16 ± 1.2% [− 2.2–2.5] and 0.84 ± 2.4 [− 5.5–3.8], respectively). Patients with left heart failure have a RV systolic dysfunction that can be unmasked by advanced echocardiographic imaging: mean RV strain was − 21 ± 5.7% in patients without RV dysfunction and − 15.8 ± 5.1% in patients with RV dysfunction (p = 0.0001). Mean RV strain showed the highest diagnostic accuracy to predict depressed RVEF (area under the curve (AUC) 0.75) with moderate sensitivity (60.5%) but high specificity (87.5%) using a cutoff value of − 16%. Conclusions RV strain seems to be a promising and more efficient measure than previous RV echocardiographic parameters for the diagnosis of RV systolic dysfunction. [ABSTRACT FROM AUTHOR]

Background: Advanced heart failure treated with a left ventricular assist device is associated with a higher risk of right heart failure. Many advanced heart failures patients are treated with an ICD, a relative contraindication to MRI, prior to assist device placement. Given this limitation, left and right ventricular function for patients with an ICD is calculated using radionuclide angiography utilizing planar multigated acquisition (MUGA) and first pass radionuclide angiography (FPRNA), respectively. Given the availability of MRI protocols that can accommodate patients with ICDs, we have correlated the findings of ventricular functional analysis using radionuclide angiography to cardiac MRI, the reference standard for ventricle function calculation, to directly correlate calculated ejection fractions between these modalities, and to also assess agreement between available echocardiographic and hemodynamic parameters of right ventricular function.Methods: A retrospective review from January 2012 through May 2014 was performed to identify advanced heart failure patients who underwent both cardiac MRI and radionuclide angiography for ventricular functional analysis. Nine heart failure patients (8 men, 1 woman; mean age of 57.0 years) were identified. The average time between the cardiac MRI and radionuclide angiography exams was 38.9 days (range: 1 - 119 days). All patients undergoing cardiac MRI were scanned using an institutionally approved protocol for ICD with no device-related complications identified. A retrospective chart review of each patient for cardiomyopathy diagnosis, clinical follow-up, and echocardiogram and right heart catheterization performed during evaluation was also performed.Results: The 9 patients demonstrated a mean left ventricular ejection fraction (LVEF) using cardiac MRI of 20.7% (12 - 40%). Mean LVEF using MUGA was 22.6% (12 - 49%). The mean right ventricular ejection fraction (RVEF) utilizing cardiac MRI was 28.3% (16 - 43%), and the mean RVEF calculated by FPRNA was 32.6% (9 - 56%). The mean discrepancy for LVEF between cardiac MRI and MUGA was 4.1% (0 - 9%), and correlation of calculated LVEF using cardiac MRI and MUGA demonstrated an R of 0.9. The mean discrepancy for RVEF between cardiac MRI and FPRNA was 12.0% (range: 2 - 24%) with a moderate correlation (R = 0.5). The increased discrepancies for RV analysis were statistically significant using an unpaired t-test (t = 3.19, p = 0.0061). Echocardiogram parameters of RV function, including TAPSE and FAC, were for available for all 9 patients and agreement with cardiac MRI demonstrated a kappa statistic for TAPSE of 0.39 (95% CI of 0.06 - 0.72) and for FAC of 0.64 (95% of 0.21 - 1.00).Conclusion: Heart failure patients are increasingly requiring left ventricular assist device placement; however, definitive evaluation of biventricular function is required due to the increased mortality rate associated with right heart failure after assist device placement. Our results suggest that FPRNA only has a moderate correlation with reference standard RVEFs calculated using cardiac MRI, which was similar to calculated agreements between cardiac MRI and echocardiographic parameters of right ventricular function. Given the need for identification of patients at risk for right heart failure, further studies are warranted to determine a more accurate estimate of RVEF for heart failure patients during pre-operative ventricular assist device planning. [ABSTRACT FROM AUTHOR]

Although measurement of right ventricular ejection fraction (RVEF) may be relevant for evaluation of therapeutic efficacy and/or prognosis in patients with pulmonary hypertension, RVEF obtained by echocardiography has limited accuracy. In contrast, radionuclide and/or magnetic resonance imaging can measure RVEF more reliably. In this study, we investigated the relationship between RVEF measured by radionuclide angiography and the echocardiographic parameters that are recommended by the American Society of Echocardiography as representative of right heart function. There were 23 study participants with pulmonary hypertension who underwent radionuclide angiography and 2-dimensional and Doppler echocardiography ( n = 30 measurements). RVEF measured by radionuclide angiography correlated with right ventricular Tei index (RV Tei index) measured by Doppler echocardiography ( r = −0.601, P < 0.0005). Receiver operating characteristic curve analysis showed that an RV Tei index cut-off value of 0.371 was the best of predictor of RVEF ≤35% (area under the curve = 0.768, sensitivity = 0.857, selectivity = 0.667). Multiple regression analysis showed that RVEF was correlated with the RV Tei index, and this association was independent of other echocardiographic right ventricular function parameters ( r = −0.644, P < 0.005). The RV Tei index measured by Doppler echocardiography may be an acceptable surrogate marker of RVEF in patients with pulmonary hypertension. [ABSTRACT FROM AUTHOR]

Alpha-emitting radionuclides like actinium-225 ( 225 Ac) are ideal candidates for the treatment of small metastasised tumours, where the long half-life of 225 Ac enables it to also reach less accessible tumours. The main challenge lies in retaining the recoiled alpha-emitting daughter nuclides, which are decoupled from targeting agents upon emission of an alpha particle and can subsequently cause unwanted toxicity to healthy tissue. Polymersomes, vesicles composed of amphiphilic block copolymers, are capable of transporting (radio)pharmaceuticals to tumours, and are ideal candidates for the retention of these daughter nuclides. In this study, the Geant4 Monte Carlo simulation package was used to simulate ideal vesicle designs. Vesicles containing an InPO 4 nanoparticle in the core were found to have the highest recoil retention, and were subsequently synthesized in the lab. The recoil retention of two of the daughter nuclides, namely francium-221 ( 221 Fr) and bismuth-213 ( 213 Bi) was determined at different vesicle sizes. Recoil retention was found to have improved significantly, from 37 ± 4% and 22 ± 1% to 57 ± 5% and 40 ± 2% for 221 Fr and 213 Bi respectively for 100 nm polymersomes, as compared to earlier published results by Wang et al. where 225 Ac was encapsulated using a hydrophilic chelate (Wang et al. 2014). To better understand the different parameters influencing daughter retention, simulation data was expanded to include vesicle polydispersity and nanoparticle position within the polymersome. The high retention of the recoiling daughters and the 225 Ac itself makes this vesicle design very suitable for future in vivo verification. [ABSTRACT FROM AUTHOR]

Background. Despite the dose-dependent response rate of sarcomas to doxorubicin, clinicians limit its cumulative dose due to cardiotoxicity. This study evaluates early evidence of cardiotoxicity in patients treated with high-dose doxorubicin given as a continuous infusion. Methods. Data was collected on patients who received 90 mg/m2 doxorubicin as a continuous infusion and 10 gm/m2 ifosfamide for up to 6 cycles as part of a phase II study. Cardiotoxicity was assessed with serial echocardiograms or multigated acquisition scans and serum brain natriuretic peptide and troponin levels. Tumor responses were determined by serial radiographic imaging per RECIST. Result. Out of the 48 patients enrolled, no patient developed heart failure symptoms; however, 4 out of the 38 (10%) patients with serial left ventricular ejection fraction assessments developed subclinical cardiotoxicity (asymptomatic drop in LVEF ≥ 10%). Twenty-three patients received all six 72-hour cycles of doxorubicin with a mean cumulative dose of 540 mg/m2. Among these patients, 4% (n=1) developed subclinical cardiotoxicity. In the advanced disease group (n=39), patients with a complete or partial response received a higher mean cumulative dose than those with stable disease (p<0.033). Conclusions. Doxorubicin cardiotoxicity can be limited by administering doxorubicin as a continuous infusion, allowing higher cumulative dosing to maximize efficacy. [ABSTRACT FROM AUTHOR]

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Cardiac resynchronization therapy (CRT) improves functional classification among patients with left ventricle malfunction and ventricular electric conduction disorders. However, a high percentage of subjects under CRT (20%–30%) do not show any improvement. Nonetheless the presence of mechanical contraction dyssynchrony in ventricles has been proposed as an indicator of CRT response. This work proposes an automated classification model of severity in ventricular contraction dyssynchrony. The model includes clinical data such as left ventricular ejection fraction (LVEF), QRS and P-R intervals, and the 3 most significant factors extracted from the factor analysis of dynamic structures applied to a set of equilibrium radionuclide angiography images representing the mechanical behavior of cardiac contraction. A control group of 33 normal volunteers (28±5 years, LVEF of 59.7%±5.8%) and a HF group of 42 subjects (53.12±15.05 years, LVEF < 35%) were studied. The proposed classifiers had hit rates of 90%, 50%, and 80% to distinguish between absent, mild, and moderate-severe interventricular dyssynchrony, respectively. For intraventricular dyssynchrony, hit rates of 100%, 50%, and 90% were observed distinguishing between absent, mild, and moderate-severe, respectively. These results seem promising in using this automated method for clinical follow-up of patients undergoing CRT. [ABSTRACT FROM AUTHOR]

Background: The relationship between the signal from retrograde venous flow on magnetic resonance angiography (MRA) and retrograde upward flow from the left brachiocephalic vein has not been explored.Purpose: To reveal the frequency of jugular venous reflux using MRA and nuclear venography in patients being evaluated for cerebral volume and blood flow.Material and Methods: A total of 229 patients with cognitive disturbance who had undergone brain magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) on the same day to evaluate cerebral blood flow were evaluated. Jugular venous reflux was measured on MRA and nuclear venography, which was conducted just after injection of N-isopropyl-123I-p-iodoamphetamine for the SPECT study.Results: MRA showed jugular reflux in seven patients on the right side, and in 22 on the left. Nuclear venography showed jugular reflux in six patients on the right side, and in 20 on the left.Conclusion: Jugular venous reflux was observed mostly on the left side. Retrograde flow was observed on both MRA and nuclear venography in half of the cases, with the rest only on one of the modalities. [ABSTRACT FROM AUTHOR]

Purpose This study was performed to compare the diagnostic quality of Gadofosveset-enhanced magnetic resonance venography with Gadobutrol-enhanced magnetic resonance venography and computed tomography venography for the deep veins of the lower extremities in patients with iliocaval venous pathology. Materials and methods Diagnostic capability and image quality were assessed by two independent readers. Inter-reader variability was analyzed by unweighted and quadratic weighted Cohen’s kappa values. Results The diagnostic capability was equal to or higher in the Gadofosveset group for all examined vessel segments compared with both control groups. The image quality score was significantly higher for the Gadofosveset group compared to both control groups. Inter-reader variability expressed by quadratic weighted Cohen’s kappa value (k) showed less variability in the Gadofosveset group compared to the control groups. Conclusion Our results show that Gadofosveset-enhanced magnetic resonance venography is a reliable technique in clinical routine practice, with image quality superior to both Gadobutrol-enhanced magnetic resonance venography and computed tomography venography. [ABSTRACT FROM AUTHOR]