Evaluation of a 3‐dimensional ultrasound device for noninvasive measurement of urinary bladder volume in dogs

Abstract

Background The BladderScan Prime Plus (BPP; Verathon, Bothell, Washington) is an application‐specific, three‐dimensional ultrasound device used for human, point‐of‐care volumetry of the urinary bladder. Objective To estimate the BPP's accuracy, repeatability, and optimized settings for assessing urinary bladder volumes in dogs, a variable utilized in assessing micturition disorders. Animals Twenty‐four, client‐owned, healthy, male dogs presenting for routine examination. Methods Prospective examinations were conducted by an experienced ultrasonographer and a novice, selecting the BPP's “man” or “child” setting, and were compared to urine volume obtained by catheterization. Results Mean urine volume significantly varied by operator ( P = .05), device setting ( P < .001), and weight ( P = .01); the “man” setting produced mean volumes nearer to catheterized volumes. The mean difference between BPP's “man” setting and catheterized volume was 0.88 mL, with maximal positive and negative disagreement of +23.2 mL to −55.3 mL (SD 19.0). Percent disagreement between BPP and catheterized volumes demonstrated a mean of −4.5%, with maximal positive and negative disagreement of +58.1% to −74.1% (SD 34.9). The experienced operator recorded volumes significantly ( P = .05) higher than the novice, with difference in means of 3.2 mL. In dogs weighing >5.5 kg (n = 18/24), mean difference between BPP's “man” setting and catheterized measurements, regardless of operator, was not significant. Conclusions Although small magnitude interuser variability is present in BPP examinations, the device provides accurate, though imprecise quantification of bladder volume in canids weighing >5.5 kg.

Three‐dimensional bladder ultrasound for estimation of urine volume in dogs compared with traditional 2‐dimensional ultrasound methods

“…A previous study in dogs found that the accuracy of 3D ultrasound varied between the size of dogs and device setting utilized. 23 However, in our study we used a newer model of the Verathon BladderScan Prime Plus which automatically adapts to patient size and no longer has separate adult and child settings. Additional studies are warranted to investigate the accuracy of the 3D ultrasound device in different sizes of dogs and to determine if it is clinically useful in cats.…”

“…The previous study in dogs reported that an experienced operator determined a significantly higher mean volume than did novice. 23 Therefore, we believe more extensive formal training of clinical staff might result in more accurate bladder measurements.…”

“…22 The use of 3D ultrasound previously has been shown to be more accurate than 2D ultrasonographic methods for quantifying bladder volume in people, 17 and has been validated recently in dogs. 23 Our purposes were to (a) assess the validity of 3D ultrasound at variable bladder volumes in dogs and (b) evaluate estimates of 3D bladder volume obtained by a novice and traditional 2D measurements obtained by a board-certified veterinary radiologist.…”

Three‐dimensional bladder ultrasound to measure daily urinary bladder volume in hospitalized dogs

“…Inclusion criteria included hospitalization in any of the above areas for a minimum of 24 hours, ability to walk and urinate without assistance, no behavioral aggression, and no reported lower urinary tract disorders that might affect their ability to naturally void. Enrolled dogs had to weigh ≥5 kg based on increased accuracy of the device to capture bladder tracings in dogs above this weight 19,20 . Dogs were excluded if they had suspected oliguric or anuric renal failure, any history of a neurologic disorder, because of the known impact of these disorders on urine production or bladder function, or if they received an epidural during their hospitalization.…”

“…The 3D ultrasound device is intended to be used by operators with varying levels of expertise, allows for quick “bedside” measurements, and limits examination time because it reports an estimated volume in real time. Clinical application of 3D ultrasound in veterinary medicine is validated in dogs, and accurate in determining UBV and comparable to the gold standard 2D ultrasound method 19,20 . Detection of an increased URV and frequent monitoring in hospitalized dogs could be useful in identifying early signs of urinary retention.…”