Ultrasound findings in dual kidney transplantation.

PURPOSE: This study was done to analyse colour Doppler ultrasound (CDUS) findings in patients with dual kidney transplantation (DKT) and to compare renal volume and resistive index (RI) values between DKT and single kidney transplantation (SKT). MATERIALS AND METHODS: We reviewed the clinical and imaging findings [30 CDUS, five magnetic resonance (MR) and one computed tomography (CT) examination] in 30 patients with DKT (23 men and seven women; median age 65 years; range 55-82). Three patients had clinical signs of graft malfunction. Renal volumes and RI were compared with those of 14 SKT patients and comparable levels of renal function. RESULTS: Three patients had graft dysfunction: one had chronic rejection and two had pathologies involving one kidney only (one encrusted pyeloureteritis of a left graft and one occluded main artery of a left graft). Asymptomatic unilateral pathologies were seen in six cases. In asymptomatic DKT patients, no significant differences in length, volume, cortical echogenicity and RI between the two kidneys were observed; DKTs were smaller (median volume 116.7 vs. 171.6 cc) and had higher RIs (0.76 vs. 0.68) (p<0.01) than SKTs. CONCLUSIONS: CDUS provides useful information in patients with DKT, allowing detection of clinically unsuspected unilateral diseases. At comparable levels of renal function, DKT patients had higher RI and lower volumes than SKT patients.

Cholelithiasis management in a third-level pediatric center: case series and literature review.

Pediatric cholelithiasis is being increasingly diagnosed owing to the widespread use of ultrasonography, raised pediatric obesity and use of long-time parenteral nutrition. Clinical presentation is variable and complicated onset could lead to severe consequences. The aim of this study is to present a 15-years-experience of a pediatric third-level-center in treating cholelithiasis. A retrospective study collecting children with gallstone operated on between 2006 and 2020 is presented. Demographic data, clinical presentation, sonographic findings, risk factors, surgery, complications, follow-up were evaluated. 199 patients were included. Twenty-nine patients (14.5%) with cholelithiasis had a complicated onset. Patients with cholelithiasis older than 10 years had a higher rate of symptomatic/complicated onset. Hemolytic disease was the most frequent co-morbidity (16.1%). Laparoscopic cholecystectomy was performed in 192 cases (96.5%) with a conversion rate of 1.6%. Nearly 1% showed a major post-operative complication after cholecystectomy. Cholelithiasis in patients older than 10 years can be safely treated with laparoscopic cholecystectomy, especially if one or more co-morbidities are present. Laparoscopic splenectomy can be easily associated in the same procedure depending on medical indication. Definition of pediatric surgical timing guidelines would be of quite interest in the field.

Surgical validation of functional magnetic resonance urography in the study of ureteropelvic junction obstruction in a pediatric cohort.

INTRODUCTION: Ureteropelvic junction obstruction (UPJO) is one of the most common urological diseases in children. The etiology can be intrinsic, extrinsic (crossing vessel [CV] or adhesions), or mixed. To date, ultrasonography and scintigraphy are considered gold-standard imaging techniques for the study of UPJO. Functional magnetic resonance urography (fMRU) combines anatomical and functional information and has been recently evaluated for the detection of CVs in UPJO. OBJECTIVE: The objective of the study was to evaluate the concordance between fMRU and surgery in determining the etiology of UPJO and the presence of obstructing/non-obstructing CVs. STUDY DESIGN: Patients with unilateral hydronephrosis who underwent surgery after an fMRU were included in the sample. Surgical data regarding the etiology of UPJO were compared with radiological results. The etiology was divided into intrinsic, extrinsic due to CV, extrinsic due to adhesions, and mixed or cicatricial (postoperative). The concordance was calculated by means of the Cohen's kappa coefficient. RESULTS: The observed agreement between fMRU and surgical findings regarding the etiology and the presence of CV were 83.2% and 89.4%, respectively (with substantial Cohen's kappa coefficient). The sensitivity and specificity of fMRU were 0.84 and 0.93, respectively; the positive predictive value (PPV) and negative predictive value (NPV) were 0.889 and 0.897, respectively. The observed agreement regarding the type of vessel was 88.3% with a Cohen's kappa coefficient of 0.787 (substantial). DISCUSSION: In children with hydronephrosis, it is very important for the surgeon to quantify the extent of dilation, define the etiology of the obstruction, and the presence or absence of CVs. fMRU is a 'one-stop-shop' technique which provides both anatomical and functional information showing a high concordance with surgical findings, avoiding radiation exposure. CONCLUSIONS: fMRU should be considered a valid imaging technique in the study of pediatric UPJO, as it provides the surgeon with important information regarding the etiology of the obstruction for the preoperative planning.

Hydronephrosis and crossing vessels in children: Optimization of diagnostic-therapeutic pathway and analysis of color Doppler ultrasound and magnetic resonance urography diagnostic accuracy.

INTRODUCTION: Ureteropelvic junction obstruction (UPJO) is one of the most frequent urological diseases affecting the pediatric population. It can be due to both intrinsic stenosis of the junction and extrinsic causes such as the presence of crossing vessels (CVs), which can be detected by color Doppler ultrasound (CD-US). Magnetic resonance urography (MRU) is a good alternative, but sedation and infusion of a contrast agent are required. OBJECTIVE: The aim of this study was to analyze the diagnostic accuracy of CD-US and MRU in visualizing CVs in pediatric hydronephrosis, in order to decide the correct diagnostic pathway in the pre-operative phase. MATERIAL AND METHODS: A retrospective review was performed of medical records for all patients who underwent surgical treatment for hydronephrosis from August 2006 to February 2016. Ultrasound and scintigraphy had been performed on all patients. Data about CD-US and MRU were collected. A high-level technology ultrasound scanner and a 1.5 T MR scanner were used. The presence of CVs at surgery was considered the gold standard. Sensitivity, specificity, positive and negative predictive values (NPV) were calculated and reported for both of the imaging techniques. RESULTS: A total of 220 clinical charts were reviewed. Seventy-three CVs were identified at surgery (33.2% of UPJO). The median age was statistically higher in the group with CVs compared to the group without CVs (P < 0.001). The sensitivity and NPV of CD-US in detecting CVs were higher than MRU (sensitivity 93.3% vs. 71.7%, NPV 95.7% vs. 77.6%, respectively). DISCUSSION: According to the data, CD-US had higher sensitivity and NPV than MRU, resulting in superior detection of CVs. It is important for a surgeon to know that a child has a CV, especially in older children in which the incidence of extrinsic UPJO is higher. The main limitation of this study was the presence of incomplete data, due to the retrospectivity. CONCLUSIONS: In the pre-operative phase, the CD-US should be considered as the investigation of choice to detect CVs in children with hydronephrosis (Summary Fig). Moreover, CD-US has lower costs than MRU, and sedation with infusion of contrast agent is unnecessary. For the future, it could be useful to lead a prospective comparison between the two imaging techniques.

Multi-detector CT in the paediatric urinary tract.

The use of paediatric multi-slice CT (MSCT) is rapidly increasing worldwide. As technology advances its application in paediatric care is constantly expanding with an increasing need for radiation dose control and appropriate utilization. Recommendations on how and when to use CT for assessment of the paediatric urinary tract appear to be an important issue. Therefore the European Society of Paediatric Radiology (ESPR) uroradiology task force and European Society of Urogenital Radiology (ESUR) paediatric working groups created a proposal for performing renal CT in children that has recently been published. The objective of this paper is to discuss paediatric urinary tract CT (uro-CT) in more detail and depth. The specific aim is not only to offer general recommendations on clinical indications and optimization processes of paediatric CT examination, but also to address various childhood characteristics and phenomena that facilitate understanding the different approach and use of uro-CT in children compared to adults. According to ALARA principles, paediatric uro-CT should only be considered for selected indications provided high-level comprehensive US is not conclusive and alternative non-ionizing techniques such as MR are not available or appropriate. Optimization of paediatric uro-CT protocols (considering lower age-adapted kV and mAs) is mandatory, and the number of phases and acquisition series should be kept as few as possible.

Novel automated system for magnetic resonance imaging quantification of the inflamed synovial membrane volume in patients with juvenile idiopathic arthritis.

OBJECTIVE: To introduce a novel automated method for the quantification of the inflamed synovial membrane volume (SV) using magnetic resonance imaging (MRI), and to investigate its feasibility and validity in patients with juvenile idiopathic arthritis (JIA). METHODS: The tool was tested on 58 patients with JIA and wrist involvement. Thirty-six patients had a 1-year MRI followup. MRI of the clinically more affected wrist was performed using a 1.5T scanner and a Flex small coil. An algorithmic approach, based on supervised voxel classification for automatic estimation of SV in a 3-dimensional MRI, was developed. The SV was estimated as the number of positively classified voxels and then normalized by the patient's body surface (NSV). Validation procedures included the analysis of reliability, construct validity, responsiveness to change, discriminant validity, and the predictive value. RESULTS: The agreement between the automated estimation of NSV and the manual measurements was excellent (intraclass correlation coefficient 0.93, 95% confidence interval 0.79-0.98). The automatic NSV demonstrated good construct validity by yielding strong correlations with local signs of disease activity and a moderate correlation with global physician assessment of disease activity and with the Rheumatoid Arthritis Magnetic Resonance Imaging Scoring system synovitis score. NSV showed a strong responsiveness to clinical change (standardized response mean values >1) and satisfactory discriminant validity. High baseline NSV (>4.6) had high predictive value (100%) with respect to erosive progression. CONCLUSION: The proposed automated method allowed reliable quantification of NSV, which represents a promising imaging biomarker of disease activity in JIA. The automated system has the potential to improve the longitudinal assessment of JIA and to predict progressive joint destruction.

Diffusion-weighted MRI sequences (DW-MRI) of the kidney: normal findings, influence of hydration state and repeatability of results.

PURPOSE: This study was performed to determine the apparent diffusion coefficient (ADC) of the normal kidney using diffusion-weighted magnetic resonance imaging (DW-MRI) sequences and to analyse both the changes due to hydration state and results repeatability. MATERIALS AND METHODS: Ten volunteers underwent DW-MRI imaging of the kidneys with a breath-hold single-shot spin-echo planar imaging (SE-EPI) sequence in the axial and coronal planes with b values of 300, 500, 800 s/mm(2), in different states of hydration. Urine osmolarity (OsmU) and sodium excretion (NaU) were measured at the time of each examination. ADC maps were created for all b values, and ADC values were calculated and compared between different states of hydration. In five subjects, the protocol was conducted twice to test data repeatability. RESULTS: ADC values were lower with higher b values (3.00 vs. 2.47 vs. 1.99 x 10(-3) mm(2)/s with b values of 300, 500, 800 s/mm(2), respectively). ADC values in different hydration states were not statistically different. Measurements were reproducible. OsmU and NaU were statistically different in the different states of hydration (p<0.01). CONCLUSIONS: ADC values significantly decrease with higher b values. Average ADC values in the normal kidney are reproducible. Hydration state does not significantly influence mean ADC values.