DMSA Research Articles

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.

Evidence-based clinical practice guideline for management of urinary tract infection and primary vesicoureteric reflux.

We present updated, evidence-based clinical practice guidelines from the Indian Society of Pediatric Nephrology (ISPN) for the management of urinary tract infection (UTI) and primary vesicoureteric reflux (VUR) in children. These guidelines conform to international standards; Institute of Medicine and AGREE checklists were used to ensure transparency, rigor, and thoroughness in the guideline development. In view of the robust methodology, these guidelines are applicable globally for the management of UTI and VUR. Seventeen recommendations and 18 clinical practice points have been formulated. Some of the key recommendations and practice points are as follows. Urine culture with > 104 colony forming units/mL is considered significant for the diagnosis of UTI in an infant if the clinical suspicion is strong. Urine leukocyte esterase and nitrite can be used as an alternative screening test to urine microscopy in a child with suspected UTI. Acute pyelonephritis can be treated with oral antibiotics in a non-toxic infant for 7-10days. An acute-phase DMSA scan is not recommended in the evaluation of UTI. Micturating cystourethrography (MCU) is indicated in children with recurrent UTI, abnormal kidney ultrasound, and in patients below 2years of age with non-E. coli UTI. Dimercaptosuccinic acid scan (DMSA scan) is indicated only in children with recurrent UTI and high-grade (3-5) VUR. Antibiotic prophylaxis is not indicated in children with a normal urinary tract after UTI. Prophylaxis is recommended to prevent UTI in children with bladder bowel dysfunction (BBD) and those with high-grade VUR. In children with VUR, prophylaxis should be stopped if the child is toilet trained, free of BBD, and has not had a UTI in the last 1year. Surgical intervention in high-grade VUR can be considered for parental preference over antibiotic prophylaxis or in children developing recurrent breakthrough febrile UTIs on antibiotic prophylaxis.

Complete Remission of Renal Scarring in Follow-Up DMSA Renal Scintigraphy After Urinary Tract Infection.

Our study aimed to investigate the association between the characteristics of patients/images and complete remission of renal scarring shown in the first chronic phase Technetium-99m dimercaptosuccinic acid (DMSA) renal scintigraphy images in children with urinary tract infection (UTI). Fifty children, who underwent the chronic phase of DMSA scintigraphy more than twice following UTI diagnosis and had renal scarring in the first chronic phase DMSA renal scintigraphy, were enrolled. They were classified into 2 groups: with and without complete remission of renal scarring on the second chronic phase DMSA renal scintigraphy. Renal scarring was classified into 3 grades based on severity per the image findings. Seven cases had complete remission from renal scarring. There were significant differences in age and severity. Renal scarring might be completely reversed in young children without severe findings on DMSA renal scintigraphy. Additional chronic phase examination may aid in follow-up completion and patients' peace of mind.

Thrombocytopenia Associated with Elemental Mercury Poisoning in Two Siblings - Connecticut, July 2022.

Two siblings aged 5 and 15 years from Connecticut were hospitalized with petechial rash, oral mucositis, and severe thrombocytopenia approximately 10 days after they played with a jar of elemental mercury they found in their home. Before the mercury exposure was disclosed, the siblings were treated with platelet transfusions, intravenous immune globulin (IVIG) for possible immune thrombocytopenic purpura, and antibiotics for possible infectious causes. When their conditions did not improve after 6 days, poison control facilitated further questioning about toxic exposures including mercury, testing for mercury, and chelation with dimercaptosuccinic acid. The older sibling soon recovered, but the younger child required a prolonged hospitalization for severe thrombocytopenia, ultimately receiving repeated doses of IVIG, steroids, and romiplostim, a thrombopoietin receptor agonist. Close collaboration among multiple agencies was required to identify the extent of mercury contamination, evaluate and treat the other family members, and decontaminate the home. These cases demonstrate the importance of ongoing public health outreach to promote early detection of elemental mercury toxicity, and the need to evaluate for environmental exposures when multiple close contacts experience similar signs and symptoms.

Magnetoliposomes with Calcium-Doped Magnesium Ferrites Anchored in the Lipid Surface for Enhanced DOX Release.

Nanotechnology has provided a new insight into cancer treatment by enabling the development of nanocarriers for the encapsulation, transport, and controlled release of antitumor drugs at the target site. Among these nanocarriers, magnetic nanosystems have gained prominence. This work presents the design, development, and characterization of magnetoliposomes (MLs), wherein superparamagnetic nanoparticles are coupled to the lipid surface. For this purpose, dimercaptosuccinic acid (DMSA)-functionalized Ca0.25Mg0.75Fe2O4 superparamagnetic nanoparticles were prepared for the first time. The magnetic nanoparticles demonstrated a cubic shape with an average size of 13.36 nm. Furthermore, their potential for photothermal hyperthermia was evaluated using 4 mg/mL, 2 mg/mL, and 1 mg/mL concentrations of NPs@DMSA, which demonstrated a maximum temperature variation of 20.4 °C, 11.4 °C, and 7.3 °C, respectively, during a 30 min NIR-laser irradiation. Subsequently, these nanoparticles were coupled to the lipid surface of DPPC/DSPC/CHEMS and DPPC/DSPC/CHEMS/DSPE-PEG-based MLs using a new synthesis methodology, exhibiting average sizes of 153 ± 8 nm and 136 ± 2 nm, respectively. Doxorubicin (DOX) was encapsulated with high efficiency, achieving 96% ± 2% encapsulation in non-PEGylated MLs and 98.0% ± 0.6% in stealth MLs. Finally, drug release assays of the DOX-loaded DPPC/DSPC/CHEMS MLs were performed under different conditions of temperature (37 °C and 42 °C) and pH (5.5 and 7.4), simulating physiological and therapeutic conditions. The results revealed a higher release rate at 42 °C and acidic pH. Release rates significantly increased when introducing the stimulus of laser-induced photothermal hyperthermia at 808 nm (1 W/cm2) for 5 min. After 48 h of testing, at pH 5.5, 67.5% ± 0.5% of DOX was released, while at pH 7.4, only a modest release of 27.0% ± 0.1% was achieved. The results demonstrate the potential of the MLs developed in this work to the controlled release of DOX under NIR-laser stimulation and acidic environments and to maintain a sustained and reduced release profile in physiological environments with pH 7.4.

Evaluation of Dimercaptosuccinic Acid-Coated Iron Nanoparticles Immunotargeted to Amyloid Beta as MRI Contrast Agents for the Diagnosis of Alzheimer's Disease.

Nanoparticle-based magnetic contrast agents have opened the potential for magnetic resonance imaging (MRI) to be used for early non-invasive diagnosis of Alzheimer's disease (AD). Accumulation of amyloid pathology in the brain has shown association with cognitive decline and tauopathy; hence, it is an effective biomarker for the early detection of AD. The aim of this study was to develop a biocompatible magnetic nanoparticle targeted to amyloid beta (Aβ) plaques to increase the sensitivity of T2-weighted MRI for imaging of amyloid pathology in AD. We presented novel iron core-iron oxide nanoparticles stabilized with a dimercaptosuccinic acid coating and functionalized with an anti-Aβ antibody. Nanoparticle biocompatibility and cellular internalization were evaluated in vitro in U-251 glioblastoma cells using cellular assays, proteomics, and transmission electron microscopy. Iron nanoparticles demonstrated no significant in vitro cytotoxicity, and electron microscopy results showed their movement through the endocytic cycle within the cell over a 24 h period. In addition, immunostaining and bio-layer interferometry confirmed the targeted nanoparticle's binding affinity to amyloid species. The iron nanoparticles demonstrated favourable MRI contrast enhancement; however, the addition of the antibody resulted in a reduction in the relaxivity of the particles. The present work shows promising preliminary results in the development of a targeted non-invasive method of early AD diagnosis using contrast-enhanced MRI.

Posterior urethral valve in thai boys

BackgroundPosterior urethral valve (PUV) is the most common congenital bladder outlet obstruction in boys, causing renal damage beginning in utero. There are scarce data from Thailand regarding the long-term outcomes of PUV in boys, thus the aim of this study was to examine the presentation, clinical course, complications, outcomes and renal survival in PUV boys.MethodsWe reviewed the medical records of PUV boys treated at the Pediatric Nephrology Clinic, Prince of Songkla University, Thailand, over a 30-year-period.ResultsSeventy-seven PUV boys were identified, with a median age at diagnosis of 4.8 months. The most common presentations were urinary tract infection (UTI), poor urine stream and urinary dribbling in 26 (33.8%), 19 (24.7%) and 11 (14.3%) boys, respectively. Renal ultrasound results in 70 boys showed 8 (11.4%) unilateral and 56 (80%) bilateral hydronephroses. Of 72 voiding cystourethrograms, 18 (25.0%) showed unilateral and 22 (30.6%) bilateral vesicoureteral refluxes. 99mTc dimercaptosuccinic acid renal scans in 30 boys showed 12 (40%) unilateral and 8 (26.7%) bilateral renal damage. Fifty-nine (76.6%) boys had 149 UTIs; 42 (54.4%) had recurrent UTI. Forty-eight boys had valve ablation at the median age of 30.3 months. 22 boys (28.6%) developed chronic kidney disease (CKD) at a median age of 15.0 years.ConclusionOf 77 PUV Thai boys, UTI was the most common presentation. Recurrence of UTI and CKD was the most common consequence. Lifelong follow-up for renal and bladder functions is essential for all PUV patients.

Successful rescue pneumovesicoscopic surgery for post-Deflux® vesicoureteral junction obstruction.

Vesicoureteral junction (VUJ) obstruction after Deflux® subureteral injection for vesicoureteral reflux (VUR) is rare and minimally invasive management has not been reported. This work investigated the patients who underwent Deflux® injection for VUR and identified those with subsequent VUJ obstruction. Medical records of matched patients from October 2003 to March 2022 were reviewed, and parameters were retrospectively studied. All patients underwent Deflux® injection. The injection was performed under general anesthesia using the same manner. For patients complicated with VUJ obstruction, the symptoms, signs, management, images, renal ultrasounds, Tc-99m dimercaptosuccinic acid renal scintigraphy, histology of VUJ region, and outcomes were documented and reported. VUJ stenosis was diagnosed by performing renal ultrasound and magnetic resonance imaging. Totally 407 patients (554 ureterorenal units) received Dx/HA injections for VUR. VUJ obstruction was found in three patients (four ureterorenal units). Originally, three were grade V VUR, and one was grade IV. The repeated injection was not a risk factor for VUJ obstruction. The overall incidence of VUJ obstruction post-Dx/HA injection was 0.7% by ureter. The incidences were 0%, 0.75%, and 2.25% for grade I-III, IV, and V VUR, respectively. After the initial conversion case of pneumovesicoscopic ureteral reimplantation, the procedure was performed smoothly and successfully in the two following cases. Pneumovesicoscopic ureteral reimplantation offers an alternative for VUJ obstruction following Dx/HA injection for VUR. Fibrosis and foreign-body reaction may influence the feasibility. High-grade VUR and young age of injection were related to VUJ obstruction.

Bifunctional linker-assisted assembly of core-shell TiO2 @In2S3 with enhanced photocatalytic activity for reduction of Cr(VI)

Monodispersed anatase TiO2 microspheres were prepared by a modified sol-gel method. In2S3 nanoparticles (NPs) were loaded on the as-prepared TiO2 to form non-core-shell TiO2/In2S3 and core-shell TiO2 @In2S3 composites through a direct deposition method and a linker-assisted assembly strategy, respectively. The catalytic activity of TiO2/In2S3 and TiO2 @In2S3 for HCOONH4-mediated photoreduction of Cr(VI) was comparatively studied. Based on soft and hard acid-base theory and experimental results, the mechanisms for forming the core-shell TiO2 @In2S3 and enhancing photocatalytic activity were elucidated. Results indicate: i) When TiO2 surface is functionalized by dimercaptosuccinic acid (DMSA), a bifunctional linker, In2S3 NPs can be uniformly and tightly attached onto the TiO2 to form core-shell TiO2 @In2S3 composite via the strong binding force between In3+ ions and thiol groups (–SH), whereas In2S3 NPs can't be evenly and firmly anchored to bare TiO2 due to the weaker affinity of In2S3 NPs for TiO2 and thereby non-core-shell TiO2/In2S3 composite is obtained. ii) TiO2 @In2S3 exhibits superior photocatalytic activity to TiO2/In2S3, which can be attributed to more efficient interfacial electron transfer between In2S3 and TiO2 in TiO2 @In2S3 than that in TiO2/In2S3.

Interaction of Iron Oxide Nanoparticles with Macrophages Is Influenced Distinctly by "Self" and "Non-Self" Biological Identities.

Upon contact with biological fluids like serum, a protein corona (PC) complex forms on iron oxide nanoparticles (IONPs) in physiological environments and the proteins it contains influence how IONPs act in biological systems. Although the biological identity of PC-IONP complexes has often been studied in vitro and in vivo, there have been inconsistent results due to the differences in the animal of origin, the type of biological fluid, and the physicochemical properties of the IONPs. Here, we identified differences in the PC composition when it was derived from the sera of three species (bovine, murine, or human) and deposited on IONPs with similar core diameters but with different coatings [dimercaptosuccinic acid (DMSA), dextran (DEX), or 3-aminopropyl triethoxysilane (APS)], and we assessed how these differences influenced their effects on macrophages. We performed a comparative proteomic analysis to identify common proteins from the three sera that adsorb to each IONP coating and the 10 most strongly represented proteins in PCs. We demonstrated that the PC composition is dependent on the origin of the serum rather than the nature of the coating. The PC composition critically affects the interaction of IONPs with macrophages in self- or non-self identity models, influencing the activation and polarization of macrophages. However, such effects were more consistent for DMSA-IONPs. As such, a self biological identity of IONPs promotes the activation and M2 polarization of murine macrophages, while a non-self biological identity favors M1 polarization, producing larger quantities of ROS. In a human context, we observed the opposite effect, whereby a self biological identity of DMSA-IONPs promotes a mixed M1/M2 polarization with an increase in ROS production. Conversely, a non-self biological identity of IONPs provides nanoparticles with a stealthy character as no clear effects on human macrophages were evident. Thus, the biological identity of IONPs profoundly affects their interaction with macrophages, ultimately defining their biological impact on the immune system.

Antimicrobial resistance of breakthrough urinary tract infections in young children receiving continual antibiotic prophylaxis.

Continual antibiotic prophylaxis (CAP) can reduce the risk of recurrent UTI (rUTI). However, antimicrobial resistance in subsequent UTIs is a concern. This study aimed to explore antimicrobial resistance in young children prescribed CAP for rUTIs. A retrospective review of patient records/microbiology results was undertaken for children < 2years of age, on CAP, with 2-3 clean catch/mid-stream/supra-pubic aspirate urine cultures with a pure growth of bacteria, between January 2017 and December 2019. One hundred twenty-four urine specimens from 54 patients (26 (48%) males, median age 6months) were analysed. CAP prescribed was trimethoprim in 37 (69%), cefalexin in 11 (29%), and nitrofurantoin in 6 (11%). Based on antimicrobial susceptibility of the index UTI within the study period, 41 patients (76%) grew organisms on urine culture classified as sensitive and 13 (24%) resistant. Thirty-five (65%) children had congenital anomaly of the kidneys and urinary tract (CAKUT); they were more likely to be in the resistant group (P = 0.032). Escherichia coli (37/54, 69%) was the commonest index uropathogen. The resistant group had a higher proportion of non-E. coli index UTI pathogens (P = 0.098). Breakthrough UTI with a CAP-resistant organism was more likely in the resistant group (P = 0.010). Age, sex, and kidney scarring on DMSA (dimercaptosuccinic acid) scan were not significantly different between groups. Conclusion: Over a 3-year period, the proportion of children on CAP with resistant organism UTI doubled and resistant infections were more likely in children with CAKUT. Development of non-antimicrobial prophylaxis options is required. What is Known: • Recurrent urinary tract infections are common in children, particularly in those with underlying anatomical abnormalities of the kidneys and urinary tract. •Continuous antibiotic prophylaxis is used frequently in these children, however there is a lack of consensus on whether the potential benefits of CAP outweigh the harms. What is New: • This study adds further evidence towards the consequences of using continuous antibiotic prophylaxis in recurrent UTI; specifically, a 2-fold increase in antimicrobial resistance was seen in subsequent UTIs following long-term use of CAP, providing further vigour for the need for non-antibiotic alternatives.

Large-scale production of superparamagnetic iron oxide nanoparticles by flame spray pyrolysis: In vitro biological evaluation for biomedical applications

Despite the large number of synthesis methodologies described for superparamagnetic iron oxide nanoparticles (SPIONs), the search for their large-scale production for their widespread use in biomedical applications remains a mayor challenge. Flame Spray Pyrolysis (FSP) could be the solution to solve this limitation, since it allows the fabrication of metal oxide nanoparticles with high production yield and low manufacture costs. However, to our knowledge, to date such fabrication method has not been upgraded for biomedical purposes. Herein, SPIONs have been fabricated by FSP and their surface has been treated to be subsequently coated with dimercaptosuccinic acid (DMSA) to enhance their colloidal stability in aqueous media. The final material presents high quality in terms of nanoparticle size, homogeneous size distribution, long-term colloidal stability and magnetic properties. A thorough in vitro validation has been performed with peripheral blood cells and mesenchymal stem cells (hBM-MSCs). Specifically, hemocompatibility studies show that these functionalized FSP-SPIONs-DMSA nanoparticles do not cause platelet aggregation or impair basal monocyte function. Moreover, in vitro biocompatibility assays show a dose-dependent cellular uptake while maintaining high cell viability values and cell cycle progression without causing cellular oxidative stress. Taken together, the results suggest that the FSP-SPIONs-DMSA optimized in this work could be a worthy alternative with the benefit of a large-scale production aimed at industrialization for biomedical applications.

Near-lossless Compression of Tc-99 m DMSA Scan Images Using Discrete Cosine Transformation.

The objective of this study was to optimize the threshold for discrete cosine transform (DCT) coefficients for near-lossless compression of Tc-99 m Dimercaptosuccinic acid (DMSA) scan images using discrete cosine transformation. Two nuclear medicine (NM) Physicians after reviewing several Tc-99 m DMSA scan images provided 242 Tc-99 m DMSA scan images that had scar. These Digital imaging and communication in medicine (DICOM) images were converted in the Portable Network Graphics (PNG) format. DCT was applied on these PNG images, which resulted in DCT coefficients corresponding to each pixel of the image. Four different thresholds equal to 5, 10, 15, and 20 were applied and then inverse discrete cosine transformation was applied to get the compressed Tc-99 m DMSA scan images. Compression factor was calculated as the ratio of the number of nonzero elements after thresholding DCT coefficients to the number of nonzero elements before thresholding DCT coefficients. Two NM physicians who had provided the input images visually compared the compressed images with its input image, and categorized the compressed images as either acceptable or unacceptable. The quality of compressed images was also assessed objectively using the following eight image quality metrics: perception-based image quality evaluator, structural similarity index measure (SSIM), multiSSIM, feature similarity indexing method, blur, global contrast factor, contrast per pixel, and brightness. Pairwise Wilcoxon signed-rank sum tests were applied to find the statistically significant difference between the value of image quality metrics of the compressed images obtained at different thresholds and the value of the image quality metrics of its input images at the level of significance = 0.05. At threshold 5, (1) all compressed images (242 out of 242 Tc-99 m DMSA scan images) were acceptable to both the NM Physicians, (2) Compressed image looks identical to its original image and no loss of clinical details was noticed in compressed images, (3) Up to 96.65% compression (average compression: 82.92%) was observed, and (4) Result of objective assessment supported the visual assessment. The quality of compressed images at thresholds 10, 15, and 20 was significantly better than that of input images at P < 0.0001. However, the number of unacceptable compressed images at thresholds 10, 15, and 20 was 6, 38, and 70, respectively. Up to 96.65%, near-losses compression of Tc-99 m DMSA images was found using DCT by thresholding DCT coefficients at a threshold value equal to 5.

Diagnostic accuracy of shear wave elastography in evaluating renal fibrosis in children with chronic kidney disease: a comparative study with nuclear scan

BackgroundChronic kidney disease (CKD) is a significant health issue in pediatric patients due to fibrosis progression. Shear wave elastography (SWE) is a noninvasive technique used to assess fibrosis in CKD, but its efficacy needs to be better established. This study aimed to compare SWE with nuclear scan in assessing fibrosis in pediatric CKD patients.AimTo determine the area of scarring/fibrosis of each kidney using shear wave elastography in chronic kidney disease and compare it with technetium-99m dimercaptosuccinic acid (DMSA) results.MethodsA prospective study included 39 chronic kidney disease patients who underwent shear wave elastography and grayscale ultrasound. DMSA scans were performed to identify scar areas of the kidneys. Young modulus was recorded for each pole of both kidneys and compared with scar areas on DMSA. Thirty-nine age-matched controls underwent shear wave elastography to estimate the average elasticity value in the normal population.ResultsThirty-nine CKD patients underwent this study, with 10 females and 29 males. The median age was 6.5 years. The cutoff value of cortical thickness ≤ 10.2 predicted scar on DMSA with a sensitivity of 79% and a specificity of 77%. The cutoff value of elasticity value ≥ 5.57 kPa predicted scar on DMSA with a sensitivity of 87% and a specificity of 96%. Median SWE values were significantly higher with the scar on DMSA (12.6 kPa) compared to no scar on DMSA (4.1 kPa). The controls mean values and standard deviation were 2.42 kPa and 0.45 kPa, respectively.ConclusionsShear wave elastography has revealed that patients with chronic kidney disease exhibit higher values in the areas where scarring has occurred, compared to non-scarred areas. Fortunately, integrating shear wave elastography into routine ultrasonography assessments is a straightforward and painless process that requires no additional preparation from the patient. Not only is this method time efficient, but it also eliminates the need for potentially risky radiation exposure from radionuclide tests in the future.

Unilateral Multicystic Dysplastic Kidney Management: A National Survey.

Risks of contralateral kidney abnormalities and chronic kidney disease necessitate follow-up for unilateral multicystic dysplastic kidneys (MCDK). A nationwide survey of senior UK pediatricians was conducted. Of the 60 responses obtained, 62% routinely perform a dimercaptosuccinic acid scan to confirm diagnosis. Eight percent routinely perform a cystogram to investigate contralateral vesicoureteric reflux. Sixty-two percent would routinely measure renal function (frequency ranging from once only to "every 2 years"). Twenty-five percent recalled MCDK nephrectomy being performed within the previous 5 years. Respondents voiced concerns that national guidance may result in an overcautious approach but could balance consensus and safe variation, and offer families choice and reassurance. The mean estimated cost of follow-up from birth to 18 years ranged from £258 to £3854. Results demonstrate significant variation in management, highlighting the need for a clear pathway to decrease unwanted variability and to ensure those at high risk of renal sequelae are recognized early, without undue investigatory burden.

Comparison of shear wave elastography and dimercaptosuccinic acid renal cortical scintigraphy in pediatric patients.

Although it causes low-dose radiation exposure, dimercaptosuccinic acid (DMSA) renal cortical scintigraphy is the gold standard examination method in the noninvasive diagnosis of renal scar tissue (RST). Shear wave elastography (SWE) has recently come to the fore as a technique for measuring kidney stiffness in the examination of RST. The present study aims to compare DMSA and SWE tests to evaluate whether SWE can be used instead of DMSA as a test that does not cause radiation exposure in pediatric patients. In this prospective study, sonographic elastography was performed on pediatric patients with DMSA images. In the SWE examination, measurements were made from each kidney's upper, middle and lower parts. DMSA and elastography data were compared for the diagnosis of RST. A total of 64 patients were included in the present study. There were 68.8% female ( n = 44) and 31.2% ( n = 20) male patients. There were 45 pediatric patients [Female 30 (66.7%), male 15 (33.3%)] in group 1 (pathological group) and 19 pediatric patients [Female 14 (73.7%), male 5 (26.3%)] in the control group. When DMSA data and SWE values were compared, it was found that elastography did not show a statistically significant performance in predicting renal scarring. In the existing literature, various studies reported different values for the diagnosis of renal stiffness using SWE. Similar to some previous studies, the present study observed no significant correlations between DMSA and SWE. Thus, DMSA preserves its major role and effectiveness as an important predictor of RST in pediatric patients.

The diagnostic value of DMSA scan in differentiating functional pseudo-tumors from malignancies in scarred kidneys: case series and literature review

BackgroundThe terms “renal regenerating nodule” and “nodular compensatory hypertrophy” are used in the literature to describe functioning pseudo-tumors (FPT) in the setting of an extensively scarred kidney. FPTs are usually discovered incidentally during routine renal imaging. Differentiating these FPTs from renal neoplasms is critical but can be challenging in the setting of chronic kidney disease (CKD) given the limitations related to using contrast-based imaging.Case summariesWe report a pediatric case series of 5 CKD patients, with history of urinary tract infections, in which tumor-like lesions evolved in scarred kidneys and were incidentally discovered on routine renal imaging. These were diagnosed as FPT by utilizing dimercaptosuccinic acid (DMSA) imaging and showed stable size and appearance upon follow-up with ultrasound and MRI.ConclusionFPTs can be picked up on routine imaging of pediatric patients with CKD. Although larger cohort studies are needed to confirm these conclusions, our case series supports the evidence that DMSA scan showing uptake at the site of the mass can be a useful tool to suggest the diagnosis of FPTs in children with kidney scarring, and that SPECT DMSA scan adds more precision in picking up and accurately localizing FPTs compared to planar DMSA.

Membranous nephropathy caused by dimercaptosuccinic acid in a patient with Wilson’s disease: a case report and literature review

BackgroundDimercaptosuccinic acid (DMSA) therapy is a kind of chelation therapy for patients with Wilson ‘s disease (WD). While there have been reports of side effects associated with DMSA, the development of membranous nephropathy as a result of this therapy is uncommon.Case presentationWe present a case of a 19-year-old male patient with Wilson’s disease who experienced proteinuria while receiving long-term DMSA treatment. Further evaluation revealed abnormally low levels of serum ceruloplasmin and serum albumin, as well as a 24-hour urinary protein excretion of 4599.98 mg/24 h. A renal biopsy confirmed the presence of membranous nephropathy. After ruling out other potential causes, we determined that the patient’s membranous nephropathy was likely caused by DMSA. Following treatment with glucocorticoids, there was a significant reduction in proteinuria.ConclusionThis case highlights the possibility of DMSA-induced membranous nephropathy and the importance of considering this diagnosis in patients receiving DMSA treatment. Given the widespread use of DMSA in the treatment of Wilson’s disease, further research is needed to fully understand the potential role of this drug in the development of membranous nephropathy.

Differentiation between normal and abnormal kidneys using 99mTc-DMSA SPECT with deep learning in paediatric patients

To investigate the feasibility of using deep learning (DL) to differentiate normal from abnormal (or scarred) kidneys using technetium-99m dimercaptosuccinic acid (99mTc-DMSA) single-photon-emission computed tomography (SPECT) in paediatric patients. Three hundred and one 99mTc-DMSA renal SPECT examinations were reviewed retrospectively. The 301 patients were split randomly into 261, 20, and 20 for training, validation, and testing data, respectively. The DL model was trained using three-dimensional (3D) SPECT images, two-dimensional (2D) maximum intensity projections (MIPs), and 2.5-dimensional (2.5D) MIPs (i.e., transverse, sagittal, and coronal views). Each DL model was trained to determine renal SPECT images into either normal or abnormal. Consensus reading results by two nuclear medicine physicians served as the reference standard. The DL model trained by 2.5D MIPs outperformed that trained by either 3D SPECT images or 2D MIPs. The accuracy, sensitivity, and specificity of the 2.5D model for the differentiation between normal and abnormal kidneys were 92.5%, 90% and 95%, respectively. The experimental results suggest that DL has the potential to differentiate normal from abnormal kidneys in children using 99mTc-DMSA SPECT imaging.

Contrast-enhanced ultrasound for the diagnosis of acute pyelonephritis in pediatric patients with urinary tract infection: A feasibility study.

This study aimed to assess the feasibility of contrast-enhanced ultrasound (CEUS) for the diagnosis of acute pyelonephritis (APN) in pediatric patients with febrile urinary tract infection (UTI). Between March 2019 and January 2021, study participants with suspected UTI were assessed for APN using ultrasound. Parenchymal echogenicity changes, renal pelvis dilatation, and the presence of a focal suspected lesion were assessed using conventional grayscale ultrasound. The presence and location of a decreased perfusion area were evaluated using color Doppler ultrasound (CDUS) and CEUS. Agreement between each ultrasound examination and a 99mTc‒dimercaptosuccinic acid (DMSA) scan was assessed using the κ value, and the most visible period of the lesion was evaluated using CEUS. This study enrolled 21 participants (median age, 8.0 months; range, 2.0-61.0 months) with isolated urinary tract pathogens. Five increased parenchymal echotextures (11.9%) and 14 renal pelvic dilatations (33.3%) were confirmed, but no focal lesions were detected on the grayscale images. CDUS and CEUS showed decreased local perfusion suggestive of APN in two and five kidneys, respectively. DMSA scan showed substantial agreement with CEUS findings (κ = 0.80, P = 0.010), but other grayscale and CDUS findings did not agree with DMSA scan results (P > 0.05). All lesions were best observed in the late parenchymal phase on CEUS. CEUS can reveal renal perfusion defects in pediatric patients with suspected APN without radiation exposure or sedation; therefore, CEUS may be a feasible and valuable diagnostic technique.