Morphologic and functional evaluation of duplicated renal collecting systems with MR urography: A descriptive analysis.

PURPOSE: To describe the morphology and function of duplicated collecting systems in pediatric patients undergoing functional MR urography (fMRU). METHODS: This is a HIPAA compliant IRB approved retrospective study of all patients with duplicated renal collecting systems undergoing fMRU at our institution between 2010 and 2017. Two pediatric radiologists evaluated the studies to determine the presence, morphology and function of duplicated collecting systems using both T2-weighted and dynamic post-contrast fat saturated T1-weighted images. Assessed morphologic features included pelvic and calyceal dilation, partial or complete ureteral duplication, ureteral dilation, ectopic ureteral insertion and ureteroceles. Functional analysis was carried out per moiety. RESULTS: A total of 86 examinations (63 girls; 23 boys), median age 2.6 years (Standard Deviation 6.4 years, interquartile range: 0.4-10.3 years) and 107 kidneys (39 right; 30 left and 19 bilateral), which yielded 214 evaluable moieties, were included in the final sample. One hundred and sixty-three (76.1%) of the moieties had normal morphological features and normal functional results (average calyceal transit time and renal transit time of 2 min 28 s and 3 min 16 s, respectively). The remaining 51 moieties (23.8%) were hypoplastic or dysplastic. Seventy-seven (35.9%) had pelvic and calyceal dilation. Slightly more than half of the kidneys had complete ureteral duplication (60/107; 56%); 50 (50/107, 46.7%) had ectopic ureters (23 intra- and 27 extravesical) and 9 (9/107, 8.4%) had ureteroceles. CONCLUSION: fMRU provides comprehensive information regarding the morphology and function of duplicated renal collecting systems in children. In particular, fMRU is useful for assessing barely or non-functioning renal poles and ectopic ureters.

Abdominal aortic aneurysm: pictorial review of common appearances and complications.

Abdominal aortic aneurysms (AAAs) are defined as focal dilatations of the abdominal aorta that are 50% greater than the proximal normal segment or when it is more than 3 cm in maximum diameter. The early diagnosis and treatment is very important to prevent catastrophic complications. Due to its ability to assess the peri-aortic soft tissue and the exact extension of aneurysm, as well as its excellent vascular opacification and multiplanar reconstruction capabilities, computed tomography angiography (CTA) has become an integral part of the evaluation of AAA and has virtually replaced conventional angiography for the evaluation of AAA. Knowledge of the characteristic imaging features of AAA is essential for the prompt diagnosis of life-threatening complications. In this pictorial essay, we will discuss the CTA findings in AAA and its complications including rupture, infection, aorto-enteric fistula and aorto-caval fistula.

Kirner's deformity of the fifth finger: a case report.

BACKGROUND: Kirner's deformity is a rare bony deformity that is characterized by radial and volar curvature of the distal phalanx of the fifth finger. Affected patients usually present after the age of 5 years, with girls more affected than boys and bilateral involvement more common than unilateral. CASE PRESENTATION: We report a case of an eight-year-old girl who presented with progressive deformity of the right little finger. Radiographic evaluation revealed volar and radial curvature of the distal phalanx of the right fifth digit. Magnetic resonance imaging (MRI) further revealed the deformity along with widening of the physeal plate, lack of soft tissue enhancement and normal insertion of the flexor digitorum profundus tendon. The patient was followed conservatively for two years and is now being considered for corrective osteotomy. CONCLUSION: Kirner's deformity is a rare abnormality of unknown etiology. Diagnosis is made with clinical examination and imaging evaluation. Clinicians should be aware of this uncommon deformity and differentiate it from other mimickers such as infection, physeal fracture, camptodactyly, and clinodactyly.

Intra- and inter-observer variability of functional MR urography (fMRU) assessment in children.

BACKGROUND: Functional MR urography (fMRU) provides comprehensive functional data that can be subject to variability. To interpret the results of fMRU, it is essential to know the intra- and inter-observer variability of the measured parameters. OBJECTIVE: To define the range of variability in fMRU, particularly that of the differential renal function based on volume (volumetric differential renal function) and Patlak differential renal function measurements in children. MATERIALS AND METHODS: We included 15 fMRU studies, 10 of non-duplicated and 5 of unilateral duplex kidneys. We recruited six observers with a range of fMRU experience, including two MRI technologists, one resident, one fellow, one pediatric radiologist and one pediatric urologist. The observers underwent intensive training in using the Children's Hospital of Philadelphia (CHOP)-fMRU freeware for analysis. They conducted the fMRU analysis on each case twice, at least 1 week apart. Mean and standard deviation were calculated for each set of absolute volume, absolute Patlak, volumetric differential renal function and Patlak differential renal function. We calculated the statistical significance of these deviations using the student's t-test. We also calculated interclass correlations for intra-observer and inter-observer agreement of both volume and Patlak measurements using SPSS software. RESULTS: Intra- and inter-observer variability did not differ significantly, measuring 6% and 4% for relative volume (volumetric differential renal function: P > 0.05) and 5% and 3% for relative function (Patlak differential renal function: P > 0.05). Absolute values of parameters showed more variability than the relative values. Intra- and inter-observer agreement was well above 0.90 (P < 0.001) for all volume measures except for duplex upper pole intra-observer measurements (0.80, P < 0.01). Intra- and inter-observer agreement for Patlak values were also above 0.90 (P < 0.001) except for duplex upper pole measurements, which were 0.54 (P = 0.13) and 0.81 (P < 0.01), respectively. CONCLUSION: Functional MRU analysis using CHOP-fMRU software is reproducible, with overall intra- and inter-observer variability rates of 5% for volumetric differential renal function and 4% for Patlak differential renal function. There was higher variability in volume and function measurements between upper and lower pole moieties of duplicated kidneys and for absolute volume and function values overall. A range of 45-55% for relative values of volumetric differential renal function and Patlak differential renal function could serve as the normal range.

Lower Extremity Vascular Access in Neonates and Infants: A Single Institutional Experience.

PURPOSE: To demonstrate feasibility and evaluate outcomes of direct-stick saphenous and single-incision tunneled femoral noncuffed central venous catheters (CVCs) placed in a large series of neonates and infants at a single institution. MATERIALS AND METHODS: A retrospective review was performed for all neonates and infants receiving a lower extremity CVC by interventional radiology between 2007 and 2012. Technical success, mechanical and infectious complications, and catheter outcomes were recorded. RESULTS: There were 271 primary insertions performed in 243 children by interventional radiologists in the interventional radiology suite or at the bedside. CVCs were placed via the femoral vein with single-incision technique (84.9%) or the saphenous vein via a direct-stick technique (15.1%), with a technical success rate of 100%. The total number of catheter-days was 7,917 days (median, 19 d; range, 0-220 d). The number of primary catheter-days was 5,333 days (median, 15 d; range, 0-123.0 d), and salvage procedures prolonged catheter life by 2,584 days (median, 15 d; range, 1.0-101.0 d). The mechanical and adjusted infectious complication rates were 1.67 and 0.44 per 100 catheter-days. CONCLUSIONS: Image-guided placement of saphenous or tunneled femoral catheters using a single incision is a safe and feasible method for vascular access in neonates and infants.

Optimizing functional MR urography: prime time for a 30-minutes-or-less fMRU.

BACKGROUND: Current protocols for functional MR urography (fMRU) require long scan times, limiting its widespread use. OBJECTIVE: Our goal was to use pre-defined criteria to reduce the number of sequences and thus the examination time without compromising the morphological and functional results. MATERIALS AND METHODS: The standard fMRU protocol in our department consists of eight sequences, including a 17-min dynamic post-contrast scan. Ninety-nine children and young adults (43 male, 56 female, mean age 7 years) were evaluated with this protocol. Each sequence was retrospectively analyzed for its utility and factors that affect its duration. RESULTS: Mean scan time to perform the eight sequences, without including the variable time between sequences, was 40.5 min. Five sequences were categorized as essential: (1) sagittal T2 for planning the oblique coronal plane, (2) axial T2 with fat saturation for the assessment of corticomedullary differentiation and parenchymal thickness, (3) coronal 3-D T2 with fat saturation for multiplanar and 3-D reconstructions, (4) pre-contrast coronal T1 with fat saturation to ensure an appropriate scan prior to injecting the contrast material and (5) the coronal post-contrast dynamic series. Functional information was obtained after 8 min of dynamic imaging in the majority of children. The coronal fat-saturated T2, coronal T1, and post-contrast sagittal fat-saturated T1 sequences did not provide additional information. Because of the effects of pelvicalyceal dilation and ureteropelvic angle on the renal transit time, prone position is recommended, at least in children with high-grade pelvicalyceal dilation. CONCLUSION: Comprehensive fMRU requires approximately 19 min for sequence acquisition. Allowing for time between sequences and motion correction, the total study time can be reduced to about 30 min. Four pre-contrast sequences and a shortened post-contrast dynamic scan, optimally with the child in prone position, are sufficient.

Magnetic resonance urography in evaluation of duplicated renal collecting systems.

Duplex renal collecting systems are common congenital anomalies of the upper urinary tract. In most cases they are incidental findings and not associated with additional pathologies. They demonstrate, however, higher incidences of hydroureteronephrosis, ureteroceles, and ectopic ureters. The most comprehensive morphologic and functional evaluation of duplex systems can be achieved using magnetic resonance urography. Functional magnetic resonance urography allows better separation of the renal poles, thus more accurate calculation of the differential renal functions compared with renal scintigraphy. Magnetic resonance urography is the study of choice when upper urinary tract anatomy is complex or when functional evaluation is needed.

Radiologically placed tunneled hemodialysis catheters: a single pediatric institutional experience of 120 patients.

PURPOSE: To report the outcome of tunneled dialysis catheter insertion in 120 patients. MATERIALS AND METHODS: A retrospective review of the interventional radiology database and electronic medical records of 120 patients who had tunneled dialysis catheters inserted from April 1997 to July 2010 was performed with institutional review board approval. There were 61 female patients and 59 male patients, with a mean age of 13.3 years (range, 0.2-28.5 y). A total of 193 primary insertions and 330 salvage procedures were performed. RESULTS: The technical success rate for primary catheter insertions was 100%. Immediate complications included self-limiting tract bleeding and air embolism in two of 193 insertions each (1.03%). Mean indwell duration for primary insertions was 66 catheter-days (range, 1-765 d), compared with a total mean of 159.4 catheter-days (range, 1-1,034 d). Rates of infection and mechanical complications were 0.21 and 0.9 per 100 total catheter-days, respectively. Mechanical and infections complications were increased in children younger than 9 years of age and weighing less than 20 kg. The catheter removal rates for infection and mechanical complications were 0.084 and 0.081 per 100 catheter-days, respectively. Medical salvage procedures, ie, intracatheter thrombolytic agent use or antibiotic therapy (52.1%) and interventional radiologic catheter salvage procedures (47.1%), increased catheter survival by an average of 54.8 days (range, 0-959 d). CONCLUSIONS: Radiologic placement of tunneled hemodialysis catheters is a safe and technically successful procedure in pediatric patients. However, there is a high rate of infectious and mechanical complications, particularly in younger and smaller patients.

An unusual urinary tract presentation in a case of megacystis microcolon intestinal hypoperistalsis syndrome.

Megacystis microcolon intestinal hypoperistalsis syndrome is a rare congenital anomaly. Several pathogeneses have been described so far, but there is no single mechanism that can explain all the findings of the syndrome. Affected newborns usually present clinically in the first few days of life. The mainstay of diagnosis is a pre or a postnatal imaging evaluation using ultrasound or magnetic resonance imaging. We report an unusual urinary tract finding in a patient with the classic triads of the syndrome that was diagnosed with both pre and postnatal imaging evaluation.

Idiopathic macro-orchidism with testicular lobulation in an adolescent.

Marked testicular enlargement in the pediatric age group can be caused by many different conditions and is rarely idiopathic. Ultrasound is the primary imaging modality for evaluation of such cases. Bilateral asymmetric idiopathic macro-orchidism with diffuse testicular lobulations is a condition which has not been described before in the literature. We report the clinical, sonographic and histological features of this unusual combination in an adolescent boy.