Split Function Research Articles

Determination of the splitting function by signal spectrum

In modern telecommunication, spread spectrum techniques often used. Special case of spread spectrum – spectrum splitting. This technique is characterized by signals whose energy is concentrated in two or more spaced portions of the spectrum. If there is a modulating subcarrier in modulation function, and this subcarrier is shorter then duration of transmitted information symbols by a multiplicity factor, then this function provide spectrum splitting. The frequency of this subcarrier called subcarrier frequency, and function of this subcarrier called subcarrier frequency function or splitting function. The main problem of this article is the ability to determine by which split function the original spectrum of the unknown signal has obtained, because during the analysis it is necessary to understand general patterns of the signal formation. The article discusses various signals with spectrum splitting. There is an overview of the methods of spectrum splitting obtained for different types of modulation (phase, amplitude, frequency) and some splitting functions (harmonic, meander and functions of periodic triangular pulses). The spectrums of the signals obtained by different splitting functions are studied and conclusions has drawn on how to determine the splitting function and the type of modulation for the spectrum splitting of an unknown signal.

Retroperitoneal lymphadenopathy: An underappreciated contributor to acute kidney failure in patients with cancer

Introduction: Retroperitoneal lymphadenopathy represents a unique and infrequent complication within various malignancies. This case report exemplifies the intricate diagnostic challenges that arise when identifying nondilated obstructive nephropathy in the context of retroperitoneal lymphadenopathy due to diffuse large B-cell lymphoma (DLBCL), particularly when conventional imaging fails to reveal the hallmark feature of hydronephrosis. Case description: We present a 66-year-old male with relapsed chronic lymphocytic leukemia post-allogeneic stem cell transplantation. His direct admission to the hematology/oncology service was due to failure to thrive. Despite the absence of hydronephrosis on imaging, the patient developed volume overload and increased serum creatinine levels. An ultrasound unveiled mild bilateral collecting system dilation, while laboratory findings did not provide valuable insight into the underlying etiology. A Lasix renal scan confirmed split renal function with minimal bilateral excretion. High clinical suspicion resulted in an MRI scan showing interval enlargement of retroperitoneal lymph nodes and pelvicaliectasis, which prompted urological and interventional radiology involvement. Conclusions: This case underscores the complexity of diagnosing retroperitoneal lymphadenopathy and pelvicaliectasis, in DLBCL, particularly when hydronephrosis is absent on imaging. It emphasizes the significance of clinical acumen, collaboration among specialties, and the use of advanced imaging techniques. Timely recognition of nondilated obstructive nephropathy in the setting of retroperitoneal lymphadenopathy is pivotal for guiding appropriate management strategies and optimizing patient outcomes in the intricate clinical setting.

Predicting new-baseline glomerular filtration rate (NBGFR) after donor nephrectomy: validation of a split renal function (SRF)-based formula.

Accurate prediction of post-donor nephrectomy (DN) glomerular filtration rate is potentially useful for evaluating and counselling living kidney donors. Currently, there are limited tools to evaluate post-operative new-baseline glomerular filtration rate (NBGFR) in kidney donors. We aim to validate a conceptually simple formula based on split renal function (SRF)previously developed for radical nephrectomypatients. Eighty-three consecutive patients who underwent DN from 2010 to 2016 were included. Pre-operative CT imaging and functional data including pre-DNbaselineGlobal GFR (108.2 ± 13.2mL/min/1.73m2) were included.ObservedNBGFR was defined as the latest eGFR 3-12months post-DN. SRF, defined as volume of the contralateral non-resected kidney normalised by total volume of kidneys, was determined frompre-operative cross-sectional imaging (49.2 ± 2.36%). The equation derived from Rathi et al. is as detailed: Predicted NBGFR = 1.24 × (Global GFR Pre-DN) x (SRF). The relationship between predicted NBGFR (66.0 ± 8.29mL/min/1.73m2) and observed NBGFR (74.9 ± 16.4mL/min/1.73m2) was assessed by evaluating correlation coefficients, bias, precision, accuracy, and concordance. The new SRF-based formula for NBGFR prediction correlated strongly with observed post-operative NBGFR (Pearson's r = 0.729) demonstrating minimal bias (median difference = 7.190mL/min/1.73m2) with good accuracy (96.4% within ± 30%, 62.7% within ± 15%) and precision (IQR of bias = - 0.094 to 16.227). The SRF-based formula was also able to accurately discriminate all but one patient to an NBGFR of > 45mL/min/1.73m2. We utilised the newly developed SRF-based formula for predicting NBGFR in a living kidney donor population. Counselling of donor post-operative renal outcomes may then be optimised pre-operatively.

Analysis of risk factors for stenosis after laparoscopic pyeloplasty in the treatment of ureteropelvic junction obstruction.

Laparoscopic ureteroplasty is an effective method for managing ureteropelvic junction obstruction. Despite its high success rate, there remains a subset of patients who do not experience improvement in the hydrops. The study retrospectively analyzed the data of 143 patients with ureteropelvic junction obstruction (UPJO) who underwent laparoscopic pyeloplasty (LP) in our hospital from January 2015 to May 2022. Logistic regression was used to analyze the risk factors of recurrence stenosis after UPJO. Out of these patients, 119 had complete clinical data and follow-up records. Among these patients, restenosis occurred in nine cases after the operation. There was a significant statistical difference in blood loss (P < 0.05). Univariate and multivariate logistic regression analysis revealed that the preoperative separation degree of the renal pelvis, cystatin C, and intraoperative blood loss were potential risk factors for recurrent stenosis after primary LP. When divided by split renal function (SRF), the odds ratio (OR) was 7.850 (P = 0.044), indicating that it was an independent risk factor for postoperative restenosis. Similarly, the OR for stenotic segment length was 0.025 (P = 0.011), also indicating it as an independent risk factor for restenosis. The areas under the receiver operating characteristic curve for stenotic segment length and SRF were 0.9056 and 0.7697, respectively. In our study, we identified that preoperative renal pelvis separation, cystatin C, and intraoperative blood loss were potential risk factors for postoperative restenosis. SRF and stenosis segment length were independent risk factors for postoperative restenosis.

Additional moments and x-space approximations of four-loop splitting functions in QCD

We have extended our previous computations of the even-N moments of the flavour-singlet four-loop splitting functions to N=12 for the pure-singlet quark case and N=10 for all other cases. These results, obtained using physical quantities in inclusive deep-inelastic scattering, have been and will be used to validate conceptionally much more challenging determinations of these splitting functions from off-shell operator matrix elements (OMEs). For the quark-gluon and gluon-gluon splitting functions, which have yet to be computed to higher N using OMEs, we construct approximations based on our moments and endpoint constraints, where we present new large-x results for the gluon-gluon case. These approximations facilitate an approximate N3LO evolution of parton distributions which are sufficiently accurate outside the region of small momentum fractions x.

Performance study on a novel greenhouse cover structure with beam split and heat control function

Based on the principle of spacing prism, a novel greenhouse cover plate with beam split and heat control function is proposed. The visible light needed for plant growth transmits into the greenhouse and near-infrared radiation is absorbed to reduce the internal temperature. The target is to design a greenhouse cover plate that can not only reduces the temperature of greenhouse, but also reduces the energy consumption of greenhouses cooling system in summer. The relative position and size of the heat-absorbing plate are obtained through theoretical calculations. Based on the Monte Carlo light tracking principle, optical software is used to optimize the operating mode of the heat-absorbing plate. The relationship between air flow, efficiency and outlet temperature are analyzed by CFD numerical simulations. The integrating box is designed on principle of integrating ball, which is used to test this device's transmission and thermal characteristics. The test results are compared with double-layer vacuum glass under actual weather conditions. The results show that the transmission rate of spectral temperature control cover structure (STCCS) is about 60 % in the morning and afternoon, but it is lower at noon, approximately 47.32 %. Based on the thermal characteristic experiment results, it can be known that the average inside temperature of the STCCS box is decreased by 3.16 °C compared with the double-layer vacuum glass, and the thermal load is reduced by 21 %.

The Impact of Consanguinity on Severity of Posterior Urethral Valve

Background: Posterior urethral valve (PUV) is one of the frequent causes of obstructive uropathies at birth. When inadequately managed, it leads to vesicoureteric reflux disease, recurrence of UTIs, voiding disorder and chronic renal insufficiency. These valves have been observed among the siblings, twin children and also in the subsequent generation. However, their occurrence rate and association with consanguineous have never been investigated. Objective: To assess the frequency and impact of kinship on the severity of the posterior urethral valve at our centre. Study Design: A Retrospective Study Place and duration of study: Diagnosed cases of posterior urethral valves who underwent valve fulguration from Jan 2012 to April 2020 were assessed in this study, conducted at Shifa International Hospital, Islamabad. Material and method: Patients were diagnosed via voiding symptoms, ultrasound, and confirmation by VCUG and cystoscopy. In all patients, the history of consanguineous marriage and any history of PUV in the family was inquired. All cases were evaluated for renal function with BUN and creatinine, including eGFR, as per Schwartz's formula. A nuclear scan was performed in all patients to rule out renal scaring and split renal function. Results: The mean age of children who underwent valve fulguration was 4.34 + 2.7 years. Family history of first-degree cousin marriage was found in 56 (33.0%) patients. Statistical analysis of clinical parameters of the posterior urethral valve, including the degree of hydronephrosis, vesicoureteric reflux and chronic kidney disease, showed that the product of cousin marriage had more severe disease. Conclusion: One-third of PUV patients had a history of consanguineous marriages in this study. These cases develop early renal insufficiency as well as a more severe disease. Keywords: Posterior urethral valve, Consanguinity, Severity, Renal insufficiency, Retrospective Study

Possible layered lithospheric anisotropy around Longmenshan Faults by teleseismic S wave splitting and receiver functions

This study conducts an in-depth analysis of seismic anisotropy around the Longmenshan Faults. Utilizing a dataset of about 7710 earthquake catalogs from July 2007 to March 2023, we applied S wave splitting and receiver function methods to examine Pms and XKS waveforms collected from 12 fixed broadband stations across Gansu and Sichuan provinces. Our analysis revealed significant variations in seismic anisotropy between the crust and lithosphere, marked by distinct fast wave directions and delay times. These characteristics point to the possibility for layered anisotropy within the region. A two-layer anisotropy inversion analysis at key stations further delineated the differential anisotropic behaviors between the crust and the upper mantle, underscoring the impact of local geological structures and mantle dynamics. Crucially, our study posits the existence of layered anisotropy around the Longmenshan Fault Zone, a finding that significantly advances our comprehension of the region’s seismic anisotropy and adds a vital dimension to our understanding of its subsurface structural intricacies and tectonic evolution.

Role of Diuretic Renography and Ultrasonography in Pelvic Ureteric Junction Obstruction among Infants: A Prospective Interventional Study

Introduction: Renography is a non invasive technique routinely used by clinicians to provide information about kidney structure and function. However, its role in the diagnosis of renovascular disease (especially in patients with renal insufficiency), the exclusion of obstruction, and during the follow-up of patients undergoing pyeloplasty is still controversial. Aim: To study the changes in Anteroposterior Pelvic Diameter (APD), cortical thickness, split renal function and T½ post pyeloplasty at three months and to determine the usefulness of these parameters in assessing successful pyeloplasty for Pelvic Ureteric Junction Obstruction (PUJO). Materials and Methods: This prospective non randomised interventional study was conducted in the Department of Nuclear Medicine, PGIMER, Chandigarh, India and Department of Paediatrics, JIPMER, Karaikal, Puducherry, India, from July 2020 to July 2021. A total of 31 infants with persistent postnatal Hydronephrosis (HDN) on Ultrasonography (USG) with no vesicoureteral reflux were included in the study and underwent 99mTc EC renography. The diagnosis of obstruction was determined by visual interpretation, renogram curves, Time to peak (Tmax), and Time from Tmax to T½max parameters. Patients with obstructed patterns in 99mTc EC renography underwent Anderson Hyne’s dismembered pyeloplasty. After three months of surgery, 99mTc EC renography and USG were performed on all enrolled patients. The Chi-square test was used for the comparison of the difference in proportion, and the Student’s t-test was used for the comparison of the mean difference, between two groups. Results: The mean age of enrolled infants was 5.79±3.36 months with a male preponderance (27 males and 4 females). Out of 31 infants, 23 (74%) showed an obstructive pattern of drainage on diuretic renogram and underwent Anderson-Hynes dismembered pyeloplasty. The observed difference in the preoperative renal USG anteroposterior diameter (27.85±14.3 mm) and parenchymal thickness (9.6±3.3 mm) vs postoperative anteroposterior diameter (8±3.19 mm) and parenchymal thickness (15.5±4.19 mm) was statistically significant (p-value=0.001). The follow-up renogram scan conducted at three months showed a significant reduction in clearance half-time (T½). However, there was no statistically significant variation in split renal function at three months after pyeloplasty. Conclusion: Both 99mTc EC renography and USG indicate the likelihood of successful pyeloplasty, and in settings with limited resources, USG may be a viable substitute for early follow-up after pyeloplasty.

A versatile optimization framework for porous electrode design.

Porous electrodes are performance-defining components in electrochemical devices, such as redox flow batteries, as they govern the electrochemical performance and pumping demands of the reactor. Yet, conventional porous electrodes used in redox flow batteries are not tailored to sustain convection-enhanced electrochemical reactions. Thus, there is a need for electrode optimization to enhance the system performance. In this work, we present an optimization framework to carry out the bottom-up design of porous electrodes by coupling a genetic algorithm with a pore network modeling framework. We introduce geometrical versatility by adding a pore merging and splitting function, study the impact of various optimization parameters, geometrical definitions, and objective functions, and incorporate conventional electrode and flow field designs. Moreover, we show the need for optimizing geometries for specific reactor architectures and operating conditions to design next-generation electrodes, by analyzing the genetic algorithm optimization for initial starting geometries with diverse morphologies (cubic and a tomography-extracted commercial electrode), flow field designs (flow-through and interdigitated), and redox chemistries (VO2+/VO2 + and TEMPO/TEMPO+). We found that for kinetically sluggish electrolytes with high ionic conductivity, electrodes with numerous small pores and high internal surface area provide enhanced performance, whereas for kinetically facile electrolytes with low ionic conductivity, low through-plane tortuosity and high hydraulic conductance are desired. The computational tool developed in this work can further expanded to the design of high-performance electrode materials for a broad range of operating conditions, electrolyte chemistries, reactor designs, and electrochemical technologies.

Unique presentation of Congenital ureteropelvic junction obstruction in adult

Summary: A 34-year-old female, without comorbidities, presented to the emergency department with sudden right flank pain. Initial workup showed elevated WBC (14.5) and normal creatinine (0.81), but later developed fever spikes and rising CRP (59.50). Gentamicin treatment was initiated. Transferred for a Diuretic Renogram, confirming suboptimal function of the right kidney with obstruction at the renal pelvis/PUJ. Split functions indicated 32% for the right kidney and 68% for the left. Radiological workup included ultrasound, CT KUB with contrast, and CT Urography, revealing right renal acute hydronephrosis without evidence of stones. Management involved symptomatic treatment, but with persistent symptoms, Gentamicin prophylaxis was initiated. The patient was transferred for Renogram, detecting suboptimal right kidney function. A planned stent insertion followed by Robotic-assisted and laparoscopic pyeloplasty was scheduled. Discussion: Uretero Pelvic Junction Obstruction (UPJO) is a partial blockage where the ureter enters the kidney. Congenital UPJO can result from intrinsic narrowing, high ureter insertion, ureteral polyps, or accessory renal artery crossing vessels causing extrinsic compression. Most cases are detected on prenatal ultrasound, while postnatal presentations include UTI, abdominal mass, hematuria, and intermittent flank pain. Diagnosis involves CT urography and diuretic renogram, confirming suboptimal function (

Evaluation of preoperative cardiopulmonary reserve and surgical risk of patients undergoing lung cancer resection.

Lung cancer represents the second most frequent neoplasm and the leading cause of neoplastic death among both women and men, causing almost 25% of all cancer deaths. Patients undergoing lung resection-both for primary and secondary tumors-require careful preoperative cardiopulmonary functional evaluation to confirm the safety of the planned resection, to assess the maximum tolerable volume of resection or to exclude surgery, thus shifting the therapeutic approach toward less invasive options. Cardiopulmonary reserve, pulmonary lung function and mechanical respiratory function represent the cornerstones of preoperative assessment of patients undergoing major lung resection. Spirometry with carbon monoxide diffusing capacity, split function tests, exercise tests and cardiologic evaluation are the gold standard instruments to safely assess the entire cardiorespiratory function before pulmonary resection. Although pulmonary mechanical and parenchymal function, together with cardiorespiratory compliance represent the mainstay of preoperative evaluation in thoracic surgery, the variables that are responsible for fitness in patients who have undergone lung resection have expanded and are being continually investigated. Nevertheless, because of the shift to older patients who undergo lung resection, a global approach is required, taking into consideration variables like frailty status and likelihood of postoperative functional deterioration. Finally, the decision to go ahead with surgery in fragile patients being consideredfor lung resection should be evaluated in a multispecialty preoperative discussion to provide a personalized risk stratification. The aim of this review is to focus on preoperative evaluation of cardiopulmonary reserve and surgical risk stratification of patients candidate for lung cancer resection. It does so by a literature search of clinical guidelines, expert consensus statements, meta-analyses, clinical recommendations, book chapters and randomized trials (1980-2022).

Estimation of the stress intensity factor of an interface crack by the scattered SH-far field

The diffraction of the plane elastic SH-wave from a semi-infinite interface crack on junction of two elastic semi-infinite media is studied. The crack is modelled by the mathematical cut with no stress on its faces. The displacement and the stress fields are continuous outside of the crack. The wave diffraction problem is reduced to the solution of the mixed boundary value problem for Helmholtz equation. We search the solution which satisfies the Neumann boundary condition on the crack faces and the continuity condition for the stress and displacement fields outside of the crack. The radiation condition at the infinity and the Meixners condition at the crack tip must be also satisfied. Using the Fourier integral transform, the mixed boundary value problem is reduced to the Wiener-Hopf functional equation which is valid in the given strip of regularity in the complex plane. The method of factorization and decomposition, as well as the Liouvilles theorem, are used to solve this equation. Its kernel function is factorized and represented as a product of two split functions that are regular in the overlapping half-planes. These ones allow for the simple poles outside of the regularity regions. The solution of the Wiener-Hopf equation is presented in analytical form. The scattered displacement field is found for an arbitrary frequency and sounding angle by applying an inverse Fourier integral transform to the solution. The asympŹtotic formula for the stress intensity factor (SIF) at the crack tip is obtained. The correlation between complex amplitude of the SH-wave far scattered displacement field and the SIF caused by this field is obtained for an arbitrary radiation angle, frequency and medium parameters. This allows us to express the SIF through the amplitude of the far field if the radiation frequency, sounding angle as well as the physical characteristics of materials are known. It is shown that in the plane that is normal to the tip of the crack the ratio of SIF for the given junction and two fixed values of the sounding angle or two sounding frequencies is proportional to the ratio of the scattered fields. It is found that under above mentioned condition the proportionality rate does not depend on material properties. The obtained relations can be applied for estimation of the SIF with changing frequency and sounding angle.

Computed Tomography Renal Volumetry Better Predicts Postoperative Donor Renal Function in Live Kidney Donor Transplantation than Renal Scintigraphy: A Comparative Study

Introduction and Objectives: Both computed tomography (CT) and renal scintigraphy (RS) have been used to assess vascular anatomy, renal status, and split renal function (SRF). In this study, we used a recently developed software that facilitates renal volumetric evaluations to compare RS and automated CT volumetry for assessing residual renal function and, thus, estimating postoperative renal function after donor nephrectomy. Methods: Fifty-one cases of donor nephrectomy were analyzed. Residual renal function was estimated based on RS and CT volumetry. The correlation between the postoperative estimated glomerular filtration rate (eGFR) and expected SRF, measured using RS and three types of CT volumetry data (ellipsoid, thin-slice, and 5-mm slice data), was determined. Results: The correlation coefficient between actual eGFR and expected SRF was significantly associated at each time point and modality (p < 0.0001). At any time point, the difference in correlation coefficient between RS and 5-mm volumetry was significant (p value: 0.003–0.018), whereas the differences in correlation coefficients between RS and the triaxial volume calculation, and the triaxial volume calculation and 5-mm volumetry, were generally statistically insignificant. Conclusions: Expected SRF was estimated more accurately by CT volumetric calculations (especially 5-mm slice-based volumetry) than RS.

What to Expect on the Long-term Follow-up of Pediatric Pyeloplasty: Critical Time Intervals and Risk Factors

BackgroundStandard protocol for post-pyeloplasty monitoring in children and natural course of hydronephrosis resolution have not been well defined. We aimed to analyze critical time intervals and risk factors in the long-term clinical outcomes of children who were operated for ureteropelvic junction obstruction. MethodsFiles of patients who underwent open dismembered pyeloplasty between January 2000 and December 2012 and had a ≥10 years follow-up were retrospectively reviewed. Changes in SFU hydronephrosis grade, pelvis anteroposterior diameter (APD), renal parenchymal thickness, split renal functions (SRF) on MAG-3 scan as well as development of hypertension and proteinuria were noted. Complete resolution was defined as SFU grade 0–1 or APD≤10 mm or ≥50 % APD decrease. ResultsOverall, 223 patients (161 boys, 72.1 %) with a median age of 9 (range 1–185) months underwent unilateral pyeloplasty, whereas 14 patients (13 boys, 92.8 %) with a median age of 4 (range 2–39) months underwent bilateral pyeloplasty. Median follow-up was 13 (range 10–22) years. Complete resolution was observed in 190 patients (85.2 %). None of the cases required re-do pyeloplasty. Regarding unilateral cases, postoperative changes in hydronephrosis reached a plateau at the 60th month. Also, there was no significant difference regarding SRF between the 12th month and the 60th month (p > 0.05). Hypertension developed after a median period of 12 years in 13 (5.4 %) of the patients, while proteinuria developed in four (1.6 %) patients. Bilateral disease (HR: 2.518, p = 0.034) was found to be a significant determinant for development of hypertension and/or proteinuria. ConclusionsOur results indicated that ultrasonographic findings stabilized after the 60th month postoperatively, and SRF remained stable between the postoperative 12th and the 60th months. The risk of developing hypertension and/or proteinuria was 2.5 times greater in bilateral cases. Level of EvidenceLevel II.

Analysis of the Efficacy of Elastography in Comparison with Dynamic Renal Nuclear Scintigraphy in the Evaluation of Unilateral Pelvi–Ureteric Junction Obstruction

IntroductionIn hydronephrosis due to pelviureteric junction obstruction (PUJO), an obstruction to urine flow may lead to increased pelvic pressure, which may cause interstitial fibrosis and renal impairment. Recently, there have been reports on renal pelvic assessment using ultrasound elastography (USE). This study was conducted to see if USE can evaluate PUJO and if it can be correlated to the findings of the dynamic renal nuclear scan. Material and methodsIn this observational study, only patients with unilateral PUJO underwent acoustic radiation force impulse (ARFI) elastography. A rectangular region of interest (ROI) measuring 5 × 10 mm was positioned on the cortex region of the upper, mid, and lower poles of the affected kidney. Three valid measurements were obtained, from which a mean value was calculated. A dynamic renal nuclear scan using Technetium-99m ethylene dicysteine (EC or TC99 m EC) was obtained and split renal function (SRF) was used for comparison. ResultsIn the group of 20 patients, the mean age was 3.37 years. The mean SRF of the affected kidney was 26.65 %, and the corresponding USE value was 0.45 kpa. The Spearman's rho correlation coefficient for SRF and USE was 1 and 0.672, respectively (p = 0.001). Elastography was not feasible if SRF was less than 20 %. ConclusionUSE may be able to comment on the renal functional status of hydronephrosis. If USE is reported as non-feasible, it may suggest that renal function is grossly compromised. It may serve as an alternative diagnostic modality for renal functional evaluation. Level of evidenceLevel II, Prospective Cohort Study.

Non-contrast-enhanced magnetic resonance urography for measuring split kidney function in pediatric patients with hydronephrosis: comparison with renal scintigraphy.

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. Seventy-five pediatric patients with hydronephrosis were included in this retrospective study. All patients underwent NCE-MRU and RS within 2weeks. 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. 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). 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.

Nuclear medicine split renal functions correlation with CT-based renal volumes

Nuclear medicine split renal functions correlation with CT-based renal volumes

18F]PSMA-1007 PET is comparable to [99mTc]Tc-DMSA SPECT for renal cortical imaging

BackgroundScintigraphy using technetium-99m labelled dimercaptosuccinic acid ([99mTc]Tc-DMSA), taken up in the proximal tubules, is the standard in functional imaging of the renal cortex. Recent guidelines recommend performing [99mTc]Tc-DMSA scintigraphy with single photon emission computed tomography (SPECT). Prostate-specific membrane antigen (PSMA) targeted positron emission tomography (PET) is used for staging and localization of recurrence in prostate cancer. A high renal uptake is often seen on PSMA PET, concordant with known PSMA expression in proximal tubules. This suggests PSMA PET could be used analogous to [99mTc]Tc-DMSA scintigraphy for renal cortical imaging. [18F]PSMA-1007 is a promising radiopharmaceutical for this purpose due to low urinary clearance. In this study, we aimed to compare [18F]PSMA-1007 PET to [99mTc]Tc-DMSA SPECT regarding split renal uptake and presence of renal uptake defects, in patients with prostate cancer. Three readers interpreted PET and SPECT images regarding presence of renal uptake defects, with each kidney split into cranial, mid and caudal segments. Kidneys were segmented in PET and SPECT images, and left renal uptake as a percentage of total renal uptake was measured.ResultsTwenty patients with prostate cancer were included. 2 participants had single kidneys; thus 38 kidneys were evaluated. A total of 29 defects were found on both [99mTc]Tc-DMSA SPECT and [18F]PSMA-1007 PET. Cohen’s kappa for concordance regarding presence of any defect was 0.76 on a per-segment basis and 0.67 on a per-kidney basis. Spearman’s r for left renal uptake percentage between [99mTc]Tc-DMSA SPECT and [18F]PSMA-1007 PET was 0.95.Conclusions[18F]PSMA-1007 PET is comparable to [99mTc]Tc-DMSA SPECT for detection of uptake defects in this setting. Measurements of split renal function made using [18F]PSMA-1007 PET are valid and strongly correlated to measurements made with [99mTc]Tc-DMSA SPECT.

The double fermionic contribution to the four-loop quark-to-gluon splitting function

We have computed the first 30 even-N moments for the double fermionic (nf2) part of the quark-to-gluon splitting function Pgq at the fourth order of perturbative QCD via the renormalization of off-shell operator matrix elements. From these results we have determined the all-N form, and hence the exact x-space expression, using systems of Diophantine equations for its coefficients. The dominant and subdominant leading small-xnf2 contributions to Pgq(3)(x) are of the form x−1ln⁡x and ln4⁡x, respectively; the leading large-x term is ln4⁡(1−x). The coefficient of the first of these is new, the other two agree with results obtained before and thus provide checks of our results.