The landscape of systematic reviews in urology (1998 to 2015): an assessment of methodological quality.

OBJECTIVES: To assess the quality of published systematic reviews in the urology literature (an extension of our previously reported work), as high-quality systematic reviews play a paramount role in informing evidence-based clinical practice. MATERIALS AND METHODS: Our focus was on systematic reviews in the urology literature that incorporated questions of prevention and therapy. To identify such reviews published during a 36-month period (2013-2015), we systematically searched PubMed and hand-searched the table of contents of four major urology journals. Two reviewers independently assessed the methodological quality of those reviews, using the 11-point 'Assessment of Multiple Systematic Reviews' (AMSTAR) instrument. We performed protocol-driven analyses of the data from our present study's 36-month period alone, as well as in aggregate with the data from our previously reported work's study periods (2009-2012 and 1998-2008). RESULTS: In our literature search of the 36-month period (2013-2015), we initially identified 490 possibly relevant reviews, of which 125 met our inclusion criteria. The most common topic of reviews for the 2013-2015 period was oncology (51.2%; n = 64), followed by voiding dysfunction (21.6%; n = 27). The mean [standard deviation (SD)] AMSTAR score in the 2013-2015 period (n = 125) was 4.8 (2.4); 2009-2012 (n = 113), 5.4 (2.3); and 1998-2008 (n = 57), 4.8 (2.0) (P = 0.127). In the 2013-2015 period, the mean (SD) AMSTAR score for the BJU International (n = 25) was 5.6 (2.9); for The Journal of Urology (n = 20), 5.1 (2.6); for European Urology (n = 60), 4.5 (2.2); and for Urology (n = 20), 4.4 (2.2) (P = 0.106). CONCLUSIONS: The number of systematic reviews published in the urology literature has exponentially increased, year by year, but their methodological quality has stagnated. To enhance the validity and impact of systematic reviews, all authors and editors must apply established methodological standards.

Ferumoxytol-enhanced magnetic resonance imaging with volume rendering: A new approach for the depiction of internal placental structure in vivo.

INTRODUCTION: Placental function is vitally important, but placental assessment is limited by current imaging methods in vivo. The goal of this study is to determine if ferumoxytol-enhanced MR studies might be used to depict placental structure during pregnancy. METHODS: Ten pregnant women were referred for MRI evaluation of abnormal placentation. The study group was composed five of these patients whose placentas were normal at pathology. MR studies consisted of pre-contrast SSFSE (single-shot fast spin-echo), SSFP (steady-state free procession), diffusion, and ferumoxytol-enhanced acquisitions. The post-contrast sequences were compared to pre-contrast SSFSE, SSFP, and diffusion acquisitions for features of correspondence. MR images were also compared to histopathology for anatomic landmarks including the three-ring pattern of the functional vascular exchange unit (the placentone) created by this central cavity surrounded by a ring of clustered villi, and an outer ring of dispersed villi corresponding to the maternal venous outflow channel. The measured sizes of these features on MR were compared to reported sizes. RESULTS: Post-ferumoxytol images showed enhancement of the maternal blood within the placenta, notably the intervillous space and the myometrial vessels. The unenhanced fetal vessels were most visible on the MinIP (minimum intensity projection) images; the enhanced maternal vessels were most visible on the MIP (maximum intensity projection) images. Composite MIP/MinIP images show the relation of maternal and fetal circulations. The signal intensities replicate the relative contributions from enhanced maternal blood and unenhanced chorionic villi. DISCUSSION: Ferumoxytol-enhanced MR imaging can depict the internal anatomy of the placenta in vivo of clarity and detail. This could represent a new diagnostic approach to placental disorders.

Normal placental structural anatomy: ultrasound and doppler features elucidated with US-MR image fusion and ferumoxytol-enhanced MRI.

PURPOSE: To elucidate ultrasound features of normal placental anatomy through correlation of gray-scale and ultrasound Doppler with ferumoxytol-enhanced MRI features using US-MR image fusion. METHODS: All patients referred to MR for ultrasound findings worrisome for PAS (placenta accreta spectrum) were included in this retrospective study. MR studies included a ferumoxytol-enhanced T1-weighted MRI. Ultrasound imaging included gray-scale, color Doppler, power Doppler, and spectral Doppler techniques. After the MR, US-MRI fusion was performed by co-registering a MR acquisition to real-time US, which allowed precise, point-to-point correlation of placental features. RESULTS: Fourteen patients at risk for PAS were studied using the US-MR image fusion. At delivery, there were six cases without PAS (gestational age range: 24 weeks 3 days to 34 weeks 0 days), and these composed the study cohort. Placental features that were on high signal intensity on post-ferumoxytol acquisitions represent spaces with maternal blood flow and corresponded to hypoechoic areas on ultrasound created by a paucity of reflective interfaces (villi). Color and spectral Doppler allowed the separation of maternal and fetal circulations in individual perfusional domains and demonstrated spiral artery inflow, circulation around the villous tree, and return of blood flow to the basal plate. Recognizable histopathologic features by ultrasound included the central cavity, villous tree, and venous return channels. CONCLUSION: Internal placental architecture can be discerned on ultrasound. This anatomy can be correlated and confirmed with ferumoxytol-MR through US-MR fusion. Understanding this structural anatomy on ultrasound could serve as a basis to identify normal and abnormal placental features.

Ferumoxytol-enhanced MR demonstration of changes to internal placental structure in placenta accreta spectrum: Preliminary findings.

INTRODUCTION: The goal of this pilot study is to determine if ferumoxytol-enhanced MR might provide a new approach to the diagnosis of placenta accreta spectrum (PAS), and if so, to identify signs of PAS. METHODS: Ten pregnant women were referred for MRI evaluation for PAS. MR studies consisted of pre-contrast SSFSE, SSFP, DWI, and ferumoxytol-enhanced sequences. Post-contrast images were rendered as MIP and MinIP images to separately display the maternal and fetal circulations respectively. Two readers examined the images for architectural changes to placentone (fetal cotyledon) that might distinguish PAS cases from normal. Attention was given to the size and morphology of the placentone, villous tree, and vascularity. In addition, the images were examined for evidence of fibrin/fibrinoid, intervillous thrombus, basal and chorionic plate bulges. Interobserver agreement was characterized with kappa coefficients and levels of confidence for feature identification was recorded on a 10-point scale. RESULTS: At delivery, there were five normal placentas and five with PAS (one accreta, two increta, two percreta). The ten changes of placental architecture in PAS included: focal/regional expansion of placentone(s); lateral displacement and compression of the villous tree; disruption of a regular pattern of normal placentones; bulging of the basal plate; bulging of the chorionic plate; transplacental stem villi; linear/nodular bands at basal plate; non-tapering villous branches; intervillous hemorrhage; and dilated subplacental vessels. All these changes were more common in PAS; the first five achieved statistical significance in this small sample. The interobserver agreement and confidence for the identification of these features was good to excellent except for dilated subplacental vessels. DISCUSSION: Ferumoxytol-enhanced MR imaging appears to depict derangements of the internal architecture of placentas with PAS, thereby suggesting a promising new strategy to diagnose PAS.