Intravenous contrast‐enhanced dynamic MR urography: Diagnosis of vesicoureteral reflux during bladder filling with time‐signal intensity curves

Abstract

After a prompt and concave decrease of the initial third phase of the time-SI curve, intermittent spikes or a constant rise in SI above the baseline suggest the existence of VUR.

Interactive magnetic resonance voiding cystourethrography (iMRVC) for vesicoureteric reflux (VUR) in unsedated infants: a feasibility study

“…Some previous MRVC studies only examined children with known VUR, from which no sensitivity data can be obtained, unlike our study [13]. The time taken to perform the MR examination is significantly longer than an MCUG, which could make iMRVC less practical in a busy department with a heavy demand for each MR unit, but even during this pilot study we reduced the imaging time from 60 to 20 min (now comparable to standard MR examinations, e.g.…”

“…Our sample size of 12 patients is small, but adequate to demonstrate feasibility, and comparable to previous MRIbased studies of VUR (6 to 20 subjects [12][13][14][15]). Some previous MRVC studies only examined children with known VUR, from which no sensitivity data can be obtained, unlike our study [13].…”

“…For MR imaging, this group is likely to be the hardest group to image in terms of signal-to-noise ratio and identifying small moving structures, but may yield fewer motion artefacts when compared with slightly older children. No previous study using MR to identify VUR has concentrated solely on the neonatal population (average ages 3 -10 years; [11][12][13][14]). Our study avoided the use of sedation [13,14], and demonstrates feasibility on a conventional closed bore MR system [15].…”

“…No previous study using MR to identify VUR has concentrated solely on the neonatal population (average ages 3 -10 years; [11][12][13][14]). Our study avoided the use of sedation [13,14], and demonstrates feasibility on a conventional closed bore MR system [15]. Some of the earlier studies did not demonstrate VUR directly, using either ureteral dilatation with increasing bladder filling [14], or a retrograde increase in time-intensity anterograde contrast curves, as surrogate markers of reflux [13].…”

“…Magnetic resonance imaging presents an obvious alternative to the use of X-rays in small children, and early attempts to demonstrate VUR with conventional MRI have been described in adults [11] as well as children [12][13][14][15]. However, these were relatively invasive as they required intravenous (IV) or oral sedation, IV fluids, IV diuretics or gadolinium, and complicated by delays in switching between imaging sequences and locations.…”