<p><strong>INTRODUCTION: </strong>Functional renal imaging, most commonly with MAG3 nuclear medicine renal scan, is recommended in the evaluation of children with urinary tract dilation (UTD) suspected of obstructive uropathy. Alternatively, renal function can be evaluated with functional Magnetic Resonance Urography (fMRU), which has superior anatomic detail. However, there are not enough data comparing both methods' equivalency. In this study, we compare the functional and obstruction parameters of fMRU and MAG3 in a pediatric cohort presenting with obstructive uropathy.</p>

<p><strong>STUDY DESIGN: </strong>This is an IRB-approved retrospective review of all children undergoing fMRU at a single, free-standing children's hospital between May 2008 and September 2017. Patients who also underwent a MAG3 renal scan within 6 months and who had no interval surgical intervention were included in the study. Bladder catheterization was performed prior to both imaging studies.</p>

<p><strong>RESULTS: </strong>735 children had 988 fMRU studies performed during the study period. 37 unique patients (13 girls and 24 boys) with median age of 6 months (range: 2 mo-19&nbsp;y) were included in the final sample. Median time interval between studies was 70 days (range 6-179 days). The majority of participants (26/37, 70.3%) presented with UTD P3 and had diagnosis of uretero-pelvic junction obstruction (UPJO) in 21/37. Differential renal function (DRF) was used to group 10 fMRU and 9 MAG3 patients as normal; 9 fMRU and 11 MAG3 as mild; 11 fMRU and 6 MAG3 as moderate; and 7 fMRU and 6 MAG3 as severe; Wilcoxon signed-rank test (p&nbsp;=&nbsp;0.5106). Results were similar for DRF among patients with and without duplex kidneys. In the analysis of obstruction, using reference standard T½ MAG3&nbsp;≥&nbsp;20&nbsp;min, a greater or equal than 6&nbsp;min renal transit time (RTT) from fMRU showed a specificity of 94%, a sensitivity of 62%, and an AUC of 0.827.</p>

<p><strong>DISCUSSION AND CONCLUSIONS: </strong>The differential renal function determined by MAG3 and fMRU in children was not statistically different, therefore we concluded that it was similar and potentially equivalent. Better correlation was shown in patients who had normal split kidney function. While the tests are clinically equivalent, the variability of DRF within each clinical category (i.e., normal, mild, moderate, severe) is not surprising, because MAG3 does not clearly differentiate the dilated collecting system from the functional parenchymal tissue, while fMRU does. Using MAG3 as the gold standard, fMRU was 94.74% specific and 5% more sensitive in detecting UPJO with a RTT of 6min vs. 8min.</p>

<p>We surveyed three well-established store-and-forward telemedicine networks to identify any changes during the first half of 2020, which might have been due to the effect of the COVID-19 coronavirus pandemic on their telemedicine operations. The three networks all used the Collegium Telemedicus system. Various quantitative performance indicators, which included the numbers of referrals and the case-mix, were compared with their values in previous years. Two of the three networks surveyed (A and B) provided telemedicine services for any type of medical or surgical case, while the third (network C) handled only pediatric radiology cases. All networks operated in Africa, but networks A and C also provided services in other resource-constrained regions. Two of the networks (networks B and C) used local staff to submit referrals, while network A relied mainly on its expatriate staff. During the first half of 2020, the numbers of referrals received on network B increased substantially, while in contrast, the numbers of referrals on network A declined. All three networks had relatively stable referral rates during 2018 and 2019. All three networks delivered a service that was rated highly by the referrers. One network operated at relatively high efficiency compared to the other two, although it is not known if this is sustainable. The networks which were more reliant on local referrers saw little reduction-or even an increase-in submitted cases, while the network that had the most dependence on international staff saw a big fall in submitted cases. This was probably due to the effect of international travel restrictions on the deployment of its staff. We conclude that organizations wanting to build or expand their telemedicine services should consider deliberately empowering local providers as their referrers.</p>

<p>Imaging modalities for diagnosing kidney and urinary tract disorders in children have developed rapidly over the last decade largely because of advancement of modern technology. General pediatricians and neonatologists are often the front line in detecting renal anomalies. There is a lack of knowledge of the applicability, indications, and nephrotoxic risks of novel renal imaging modalities. Here we describe the clinical impact of congenital anomalies of the kidneys and urinary tract and describe pediatric-specific renal imaging techniques by providing a practical guideline for the diagnosis of kidney and urinary tract disorders.</p>