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INTRODUCTION: Zinner Syndrome (ZS), a rare congenital malformation of the mesonephric duct, combines seminal vesicle cyst (SVC) with ipsilateral upper urinary tract abnormalities. Typically asymptomatic in childhood, ZS manifests between 2nd to 4th decades with bladder symptoms, perineal pain and infertility. Diagnostic confirmation with additional imaging is needed when either renal or seminal abnormalities are identified. MATERIALS AND METHODS: A retrospective study spanning 22 years identified 20 pediatric ZS cases through clinical analytics. Demographic, clinical, and radiological data were analyzed, including presenting complaints, imaging modalities (ultrasound, CT, MRI), and surgical findings. The study was HIPAA-compliant and IRB-approved. RESULTS: Among 20 cases (mean age: 7.3 years), clinical presentations included asymptomatic cases, urinary symptoms, and abdominal pain. Imaging revealed renal anomalies (agenesis, multicystic dysplastic kidney) and seminal vesicle abnormalities. Surgical interventions (n = 12) addressed symptomatic cases, often involving robotic or laparoscopic procedures. DISCUSSION: ZS, though rare, presents with varied clinical features, necessitating a multidisciplinary approach. Early diagnosis is facilitated by prenatal identification of renal abnormalities. Surgical intervention is reserved for symptomatic cases, with techniques such as vesiculectomy and resection of remnant structures employed. CONCLUSION: This study highlights ZS's diverse clinical and radiological spectrum, emphasizing the need for vigilance in detecting overlapping entities. Timely identification, utilizing advanced imaging techniques, is crucial for accurate diagnosis and appropriate management of Zinner Syndrome in the pediatric population.
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Vesículas Seminales , Humanos , Estudios Retrospectivos , Masculino , Niño , Vesículas Seminales/anomalías , Vesículas Seminales/diagnóstico por imagen , Preescolar , Síndrome , Femenino , Adolescente , Anomalías Múltiples/diagnóstico , Conductos Mesonéfricos/anomalías , Quistes/diagnóstico , Quistes/cirugía , LactanteRESUMEN
This publication provides an overview of current imaging indications and practices for patients undergoing gender-affirming surgery, with an emphasis on the importance of tailored, patient-specific care. Gender-affirming surgeries are performed with personalized approaches at various stages of life for those with intersex traits or differences in sex development (I/DSD) and transgender and gender diverse (TGD) individuals. For I/DSD patients, ultrasound, genitography, or MRI occurs during infancy and puberty to evaluate genital and gonadal anatomy. Facial harmonization involves bony and soft tissue modifications, guided by maxillofacial computerized tomography (CT) with three-dimensional reconstruction. Ultrasound is the main modality in assessing hormone-related and post-surgical changes in the chest. Imaging for genital reconstruction uses cross-sectional images and fluoroscopy to assess neoanatomy and complications.
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Trastornos del Desarrollo Sexual , Cirugía de Reasignación de Sexo , Humanos , Masculino , Trastornos del Desarrollo Sexual/diagnóstico por imagen , Femenino , Adolescente , Cirugía de Reasignación de Sexo/métodos , Niño , Personas TransgéneroRESUMEN
Background Fluoroscopy is an imaging modality associated with a wide range of dose levels, characterized using a variety of dose metrics, including effective dose. However, for clinical procedures, effective dose is a seldom-used and unregulated metric in the United States, and thus, it is not extensively studied in radiology despite potentially large clinical implications for patients, especially children and infants. Purpose To formulate and report a dose catalog across all diagnostic and interventional radiology (IR) fluoroscopy examination or procedure types at a specialized tertiary care pediatric hospital. Materials and Methods In this retrospective study, dose metrics taken from radiation dose structured reports of fluoroscopy between October 2014 and March 2023 were analyzed. The reports included fluoroscopy across 18 diagnostic examination types and 24 IR procedure types. The National Cancer Institute dosimetry system for Radiography and Fluoroscopy Monte Carlo software was used to estimate age-specific effective dose from dose-area product (DAP). The DAP-to-effective dose conversion factors were estimated per IR procedure type and diagnostic fluoroscopy examination type based on age. Results A total of 11 536 individual diagnostic fluoroscopy examinations (18 types) and 8017 individual IR procedures (24 types) were analyzed. Median effective dose values per diagnostic fluoroscopy examination type ranged from 0.0010 to 0.44 mSv (mean, 0.0808 mSv ± 0.0998 [SD]). Calculated DAP-to-effective dose conversion factors ranged from 0.04 to 2.48 mSv/Gy · cm2 (mean, 0.758 mSv/Gy · cm2 ± 0.614) across all diagnostic fluoroscopy examination types. Median effective dose values per IR procedure type ranged from 0.0007 to 3.90 mSv (mean, 0.6757 mSv ± 0.8989). Calculated DAP-to-effective dose conversion factors ranged from 0.001 to 0.87 mSv/Gy · cm2 (mean, 0.210 mSv/Gy · cm2 ± 0.235) across all IR procedure types. Conclusion A pediatric fluoroscopy dose catalog was created, including age-specific effective dose, using a repeatable robust method based on accurate clinical data. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Borrego and Balter in this issue.
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Hospitales Pediátricos , Radiología Intervencionista , Lactante , Humanos , Niño , Estudios Retrospectivos , Fluoroscopía , Factores de EdadRESUMEN
Vesicoureteral reflux (VUR) is a common congenital anomaly of the urinary tract that can present with collecting system dilation or as a febrile infection. VUR can lead to permanent renal sequela requiring surgery but can also spontaneously resolve without complication. Therefore, it is important to recognize those patient populations who warrant imaging for screening, confirmation, or ongoing surveillance for VUR, while avoiding overdiagnosis. In the appropriate patient populations, an accurate diagnosis of VUR allows early treatment and prevention of pyelonephritis and scarring. Various imaging modalities are available to diagnose and grade VUR, including voiding cystourethrogram (VCUG), radionucleotide cystography (RNC), and contrast-enhanced voiding urosonography (ceVUS). The objective of this article is to summarize the current understanding of VUR diagnosis and management and to discuss these imaging modalities' strengths and pitfalls. Considerations include indications for VUR imaging, patient preparation, conduct of the examination, issues related to radiologic reporting, and cost-effectiveness. An emphasis is placed on ceVUS, which is the most recently introduced of the three imaging modalities and is receiving growing support among pediatric radiologists.
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BACKGROUND: There is limited quality of evidence regarding the accuracy of contrast-enhanced voiding urosonography (ceVUS) for diagnosis of vesicoureteral reflux (VUR) compared to fluoroscopic voiding cystourethrography (VCUG), and minimal data on the use of the ultrasound contrast agent Optison™ for this purpose. OBJECTIVE: To compare the accuracy of ceVUS using Optison™ to VCUG, and to assess inter-rater agreement regarding presence and grading of VUR. STUDY DESIGN: In this retrospective investigation, all sequential ceVUS with Optison™ and VCUG studies performed in children between 2014 and 2017 were reviewed. Two raters independently graded all ceVUS studies using a 5-point scale. CeVUS sensitivity and specificity were estimated separately for each rater using the VCUG report as the ground truth for presence and degree of VUR. Logistic and ordinary linear regression models assessed rater-report agreement and inter-rater agreement for each kidney, Optison™ dose, and referral diagnosis. RESULTS: 97 children (51 females) with 101 paired studies were included. Sensitivity and specificity of ceVUS for VUR detection were identical for both raters: right kidney 75%/90.9%; left kidney 85.7%/78.9% (Figure). There was no statistically significant difference in disagreement between raters and the VCUG report for the right or left kidney. Inter-rater agreement on ceVUS grading was 90% and 88% for right and left kidneys, respectively. There was a significant negative association between fetal hydronephrosis vs urinary tract infection and disagreement between Rater 2 and the VCUG report for the left kidney. There were no other significant associations with respect to either kidney, Optison™ dose, or referral diagnosis. DISCUSSION: Our study showed that detection of VUR with ceVUS and Optison™ is comparable to fluoroscopic VCUG. Based on the VCUG reports, the incidence of VUR in our patient population was substantially lower than in the meta-analysis of Chua et al. and in the study of Kim et al. The explanation for the large discrepancy in VUR incidence may reflect differences in the patient populations, and in our reporting of VUR with respect to kidney number rather than to pelviureteral units. Study limitations include its retrospective nature and potential bias in terms of patient selection. Since VUR is an intermittent phenomenon, sequential rather than simultaneous performance of the ceVUS and fluoroscopic studies might have influenced VUR detection. CONCLUSION: A blinded comparison of ceVUS performed with Optison™ to fluoroscopic VCUG showed moderate-good sensitivity and specificity for diagnosis of VUR.
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Reflujo Vesicoureteral , Niño , Femenino , Humanos , Medios de Contraste , Cistografía/métodos , Riñón/diagnóstico por imagen , Estudios Retrospectivos , Ultrasonografía/métodos , Micción , Reflujo Vesicoureteral/diagnóstico por imagen , MasculinoRESUMEN
BACKGROUND: Assessment of the ureter is a fundamental part of the radiologic evaluation of the urinary tract. Abnormal ureteral dilation warrants further investigation to assess the etiology, which includes obstruction and/or reflux. Despite this fundamental need, there are no established normative values in children based on imaging. OBJECTIVE: To provide normative values for ureteral diameter in pediatric patients with age-related ranges. MATERIALS AND METHODS: We retrospectively reviewed all magnetic resonance (MR) urography studies and chose only normal ureters for assessment. The images were analyzed on commercially available software to assess maximum internal diameter. Manual measurements were done in cases where the images were below the resolution for automated assessment. Maximum intraluminal ureteral diameters were measured in upper, mid and lower thirds and the average of the three maximum ureteral diameters was used to obtain the average widest internal ureteral diameter. Multivariable linear regression was performed to test the association between the calculated diameter and gender. Differences in sizes between the left and right ureter were assessed using paired Wilcoxon signed rank test. RESULTS: One hundred twenty-one MR urography studies were selected, which included 160 ureter units. The diameter increases progressively with age, ranging from 3.2 mm during infancy to 5.0 mm in patients older than 16 years of age. After 9 years of age, the average widest internal ureteral diameter is slightly larger in males compared to females (odds ratio [OR]=1.91, 95% confidence interval [CI] [1.63, 2.25], P<0.0001). The right ureter was slightly larger than the left (3.9 mm vs. 3.7 mm, P=0.004) among 39 patients in whom both right and left ureter units were included. The average mid ureteral diameter is widest, followed by the distal third then proximal third. CONCLUSION: We present the normative values for the average widest internal ureteral diameter based on laterality and different segments. In the pediatric population, 3.8 mm should be considered the average widest internal ureteral diameter.
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Uréter , Adolescente , Niño , Dilatación Patológica , Femenino , Humanos , Masculino , Estudios Retrospectivos , Uréter/diagnóstico por imagen , Uréter/patologíaRESUMEN
In 2014, a multidisciplinary consensus on the classification of pre- and postnatal urinary tract dilation (UTD classification) was developed. Its goal was to provide a standardized system for evaluating and reporting urinary tract dilation both in the prenatal and postnatal periods. In this review, we summarize insights learned from the implementation of the UTD classification system since its inception, providing clarifications on common points of confusion. In addition, we review current literature in the clinical validation of the UTD classification system to provide credence for its use in managing fetuses and children with urinary tract dilation.
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Hidronefrosis , Sistema Urinario , Niño , Consenso , Dilatación , Dilatación Patológica/diagnóstico por imagen , Femenino , Feto , Humanos , Masculino , Embarazo , Ultrasonografía Prenatal , Sistema Urinario/diagnóstico por imagenRESUMEN
When infants are identified with a difference of sex development (DSD), a thoughtful approach to imaging is essential to appropriate clinical management. This review provides a comprehensive guide for radiologists who are tasked with performing this critical assignment. We review the embryologic basis of DSDs, with attention to the imaging findings that can indicate specific diagnoses. We also discuss techniques for optimal imaging, including strategies for identifying the gonads by US, tactics for performing genitograms with fluoroscopy and contrast-enhanced US, and the appropriate utilization of MRI. Finally, we review the clinical data and imaging findings that characterize some of the most common DSDs, including congenital adrenal hyperplasia, complete androgen insensitivity syndrome and gonadal dysgenesis.
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Hiperplasia Suprarrenal Congénita , Trastornos del Desarrollo Sexual , Síndrome de Turner , Hiperplasia Suprarrenal Congénita/diagnóstico , Trastornos del Desarrollo Sexual/diagnóstico por imagen , Femenino , Humanos , Lactante , Masculino , Radiólogos , Desarrollo SexualRESUMEN
There is a growing demand for fast, accurate computation of clinical markers to improve renal function and anatomy assessment with a single study. However, conventional techniques have limitations leading to overestimations of kidney function or failure to provide sufficient spatial resolution to target the disease location. In contrast, the computer-aided analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) could generate significant markers, including the glomerular filtration rate (GFR) and time-intensity curves of the cortex and medulla for determining obstruction in the urinary tract. This paper presents a dual-stage fully modular framework for automatic renal compartment segmentation in 4D DCE-MRI volumes. (1) Memory-efficient 3D deep learning is integrated to localise each kidney by harnessing residual convolutional neural networks for improved convergence; segmentation is performed by efficiently learning spatial-temporal information coupled with boundary-preserving fully convolutional dense nets. (2) Renal contextual information is enhanced via non-linear transformation to segment the cortex and medulla. The proposed framework is evaluated on a paediatric dataset containing 60 4D DCE-MRI volumes exhibiting varying conditions affecting kidney function. Our technique outperforms a state-of-the-art approach based on a GrabCut and support vector machine classifier in mean dice similarity (DSC) by 3.8% and demonstrates higher statistical stability with lower standard deviation by 12.4% and 15.7% for cortex and medulla segmentation, respectively.
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Medios de Contraste , Imagen por Resonancia Magnética , Biomarcadores , Niño , Humanos , Procesamiento de Imagen Asistido por Computador , Riñón/diagnóstico por imagen , Riñón/fisiología , Redes Neurales de la ComputaciónRESUMEN
Ultrasound (US) has been increasingly used as an important imaging tool to assess the urethra in children. The earliest reports of pediatric urethral sonography involved imaging the urethra in a non-voiding state, during physiological voiding of urine, and after instillation of saline. The introduction of US contrast agents has continued to improve visualization of urethral anatomy. Contrast-enhanced US of the urethra can be performed during the voiding phase of a standard contrast-enhanced voiding urosonography (ceVUS) exam or with retrograde instillation of a contrast agent, depending on the exam indication. Both techniques are well tolerated by children and provide accurate information about urethral pathology and periurethral soft tissues. This article reviews the technical aspects and imaging findings of urethral pathologies in children using contrast-enhanced US, both by the voiding and retrograde instillation techniques.
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Uretra , Micción , Niño , Medios de Contraste , Diagnóstico por Imagen , Humanos , Masculino , Ultrasonografía , Uretra/diagnóstico por imagenRESUMEN
Imaging plays a crucial role in evaluating newborns and infants with cloacal and urogenital malformations. Contrast-enhanced genitosonography (ceGS) and contrast-enhanced colosonography (ceCS) are sensitive and radiation-free alternatives to fluoroscopic genitography and colography for diagnosis and surgical planning. These imaging techniques are performed by instilling a US contrast agent into specific body cavities to define the genitourinary and colorectal anatomy. This review article presents the experience with ceGS and ceCS applications in children, focusing on the background, examination technique, and interpretation of imaging findings, as well as strengths and weaknesses compared to conventional techniques.
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Cloaca , Anomalías Urogenitales , Animales , Niño , Medios de Contraste , Fluoroscopía , Humanos , Lactante , Recién NacidoRESUMEN
Contrast-enhanced voiding urosonography (ceVUS) is a well-established, sensitive and safe ultrasound (US) modality for detecting and grading vesicoureteral reflux (VUR) and urethral imaging in children. Nearly three decades of remarkable advances in US technology and US contrast agents have refined ceVUS's diagnostic potential. The recent approval of Lumason/SonoVue in the United States, Europe and China for pediatric intravesical applications marked the beginning of a new era for this type of contrast US imaging. Consequently, the use of ceVUS in children has expanded to multiple places around the globe. In the first part of this review article, we describe the current experience in the use of ceVUS for VUR evaluation, with an emphasis on historical background, examination technique, image interpretation and diagnostic accuracy. In the second part, we will present the role of ceVUS for urethral imaging in children.
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Reflujo Vesicoureteral , Niño , Medios de Contraste , Humanos , Lactante , Masculino , Ultrasonografía , Uretra , Micción , Reflujo Vesicoureteral/diagnóstico por imagenRESUMEN
INTRODUCTION: Understanding details of anatomic relationships between the colon and surrounding structures is a critical piece of preoperative planning prior to surgical repair of anorectal malformations (ARMs). Traditional imaging techniques involve ionizing radiation, distention of the rectum with supraphysiologic intraluminal pressures, and sometimes require sedation. Recent developments in the field of contrast agents have allowed the emergence of an ultrasound-based technique that can avoid these requirements while continuing to provide high resolution structural information in three dimensions. METHODS: Fourteen children (13 male, 1 female, age 1-11â¯months) with ARMs underwent contrast enhanced colostography (ceCS) in addition to traditional preoperative imaging techniques to delineate anatomic relationships of pelvic structures. RESULTS: ceCS and traditional imaging yielded concordant anatomic information, including structural relationships and fistulous connections, in 10/14 patients (71%). ceCS detected fistulous connection in 2/13 patients (15%) that were not seen by traditional imaging. Ultrasonography failed to detect the fistulous connection in one patient. CONCLUSIONS: ceCS is a safe, effective and flexible method for defining important structural information in ARM patients. When compared with traditional methods, it provided equivalent or superior results 93% of the time and bears consideration as a standard tool in preoperative planning for this population. TYPE OF STUDY: Retrospective Comparative Study. LEVEL OF EVIDENCE: Level III.
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Malformaciones Anorrectales , Fístula Rectal/diagnóstico por imagen , Canal Anal/diagnóstico por imagen , Malformaciones Anorrectales/diagnóstico por imagen , Medios de Contraste , Femenino , Fluoroscopía , Humanos , Lactante , Masculino , Recto/diagnóstico por imagen , Recto/cirugía , Estudios Retrospectivos , Ultrasonografía/métodosRESUMEN
Early identification of kidney function deterioration is essential to determine which newborn patients with congenital kidney disease should be considered for surgical intervention as opposed to observation. Kidney function can be measured by fitting a tracer kinetic (TK) model onto a series of Dynamic Contrast Enhanced (DCE) MR images and estimating the filtration rate parameter from the model. Unfortunately, breathing and large bulk motion events due to patient movement in the scanner create outliers and misalignments that introduce large errors in the TK model parameter estimates even when using a motion-robust dynamic radial VIBE sequence for DCE-MR imaging. The misalignments between the series of volumes are difficult to correct using standard registration due to 1) the large differences in geometry and contrast between volumes of the dynamic sequence and 2) the requirement of fast dynamic imaging to achieve high temporal resolution and motion deteriorates image quality. These difficulties reduce the accuracy and stability of registration over the dynamic sequence. An alternative registration approach is to generate noise and motion free templates of the original data from the TK model and use them to register each volume to its contrast-matched template. However, the TK models used to characterize DCE-MRI are tissue specific, non-linear and sensitive to the same motion and sampling artifacts that hinder registration in the first place. Hence, these can only be applied to register accurately pre-segmented regions of interest, such as kidneys, and might converge to local minima under the presence of large artifacts. Here we introduce a novel linear time invariant (LTI) model to characterize DCE-MR data for different tissue types within a volume. We approximate the LTI model as a sparse sum of first order LTI functions to introduce robustness to motion and sampling artifacts. Hence, this model is well suited for registration of the entire field of view of DCE-MR data with artifacts and outliers. We incorporate this LTI model into a registration framework and evaluate it on both synthetic data and data from 20 children. For each subject, we reconstructed the sequence of DCE-MR images, detected corrupted volumes acquired during motion, aligned the sequence of volumes and recovered the corrupted volumes using the LTI model. The results show that our approach correctly aligned the volumes, provided the most stable registration in time and improved the tracer kinetic model fit.
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Medios de Contraste , Imagen por Resonancia Magnética , Artefactos , Niño , Humanos , Recién Nacido , Riñón/diagnóstico por imagen , Movimiento (Física)RESUMEN
INTRODUCTION: The Urinary Tract Dilation (UTD) system was created to address variability in hydronephrosis grading. It is unknown if or how pediatric urologists are integrating this newer system into practice. OBJECTIVE: We sought to evaluate the current use of hydronephrosis grading systems, inter-rater reliability (IRR) for individual systems, and management preferences based on degree of hydronephrosis. STUDY DESIGN: A survey was emailed to the Societies for Pediatric Urology listserv. Questions addressed familiarity/preference for various grading systems and respondent confidence in interpretation of hydronephrosis. Three clinical vignettes asked respondents to grade hydronephrosis using their system of choice and report further imaging they would obtain. Descriptive statistics were calculated, and IRR was calculated using a linear-weighted modified Fleiss' kappa test. RESULTS: Response rate was 43% (n = 138). The majority of respondents used Society for Fetal Urology (SFU) (70%) or UTD (19%) systems. Most favored SFU (58%) or UTD (34%) systems for a unified system. Confidence in own interpretation was higher than confidence in radiologists' reads (median 4.4 vs 3.6, p < 0.001). IRR was substantial for UTD (κ0.68 [0.64-0.71]) and moderate for SFU (κ0.60 [0.52-0.76]). There was notable heterogeneity regarding follow-up imaging for cases. There was no difference in requested follow-up studies between SFU and UTD systems, except for fewer voiding cystourethrogram (VCUG) requests for Case 3 with UTD (28% vs 4%, p = 0.02). CONCLUSION: Most pediatric urologists still use SFU rather than the UTD system. There was slightly higher IRR with the UTD system. There was substantial variability in follow-up imaging not related to grading system, except with low grade hydronephrosis.
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Hidronefrosis , Sistema Urinario , Niño , Dilatación , Humanos , Hidronefrosis/diagnóstico por imagen , Reproducibilidad de los Resultados , UrólogosRESUMEN
The originally published version of this article contained a typographical error. In the text under the subheading "Dynamic contrast-enhanced MRI method, post-processing, and MR-GFR calculation" and in Table 1 the intravenous injection rate of gadobutrol was incorrectly listed as 0.2 mL/s.
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OBJECTIVE: To describe a technique for performing magnetic resonance urogram (MRU) in infants without sedation or anesthesia. METHODS: Eighteen infants underwent MRU in the absence of sedating medications using a 'feed and wrap' technique (FW-MRU). Dynamic contrast enhanced images were obtained. Dynamic radial VIBE and compressed sensing image reconstruction were used to correct for motion artifact. RESULTS: Seventeen of the 18 patients had successful FW-MRU. Feed and wrap' magnetic resonance urogram provided high-quality anatomic and functional renal data. CONCLUSION: Initial experience with FW-MRU demonstrates it to be a promising anesthesia-free modality for obtaining anatomic and functional imaging of the urinary tract in infants.
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Imagen por Resonancia Magnética , Sistema Urinario/anomalías , Sistema Urinario/diagnóstico por imagen , Urografía/métodos , Enfermedades Urológicas/diagnóstico por imagen , Ingestión de Alimentos , Humanos , Lactante , Cuidado del Lactante/métodos , Recién Nacido , Sistema Urinario/fisiopatología , Enfermedades Urológicas/fisiopatologíaRESUMEN
In this case series, contrast enhanced genitosonography is compared to genitography performed using fluoroscopy and cone-beam computed tomography in patients with urogenital sinus and the cloacal malformation. The method of contrast enhanced genitosonography is described, including contrast preparation, contrast administration, ultrasound imaging approaches, as well as the benefits and potential pitfalls of this technique compared to fluoroscopy and computed tomography.