Advertisement

Supine versus prone positioning for ultrasound evaluation of postnatal urinary tract dilation in children

  • Juan S. Calle-ToroEmail author
  • Carolina L. Maya
  • Yocabel Gorfu
  • Emily Dunn
  • Kassa Darge
  • Susan J. Back
Original Article
  • 56 Downloads

Abstract

Background

Ultrasound (US) is used in the initial evaluation and surveillance of urinary tract dilation in children. Urinary tract dilation is diagnosed in 1–2% of all pregnancies during routine prenatal sonography with technological advances in US imaging. Urinary tract dilation classification systems, including the 2014 multidisciplinary consensus, assess anterior–posterior renal pelvic diameter and calyceal dilation. There is no consensus regarding optimal patient positioning — supine versus prone — during US assessment of urinary tract dilation.

Objective

We performed this study to determine whether there is a significant difference in the measurement of the anterior–posterior renal pelvic diameter, presence of calyceal dilation, or resulting urinary tract dilation consensus score obtained between supine and prone positions.

Materials and methods

Two raters retrospectively reviewed renal bladder US exams of children with urinary tract dilation of one or both kidneys. We included technically adequate US examinations of orthotopic kidneys that were imaged in both supine and prone positions; we excluded children with renal anomalies or prior surgery. Anterior–posterior renal pelvic diameter measurements as well as central and peripheral calyceal dilation were documented in both supine and prone positions. A postnatal urinary tract dilation consensus score was assigned to each kidney based only on these features.

Results

Urinary tract dilation in either the supine or prone position was performed in 146 kidneys (69 right, 77 left) in 89 children. Median age was 0.26 years (interquartile ratio [IQR] 0.08–0.61 years). Female-to-male ratio was 1:3 (21/89). The interclass correlations of the anterior–posterior renal pelvic diameter were 0.88 and 0.87 in the supine and prone positions, respectively, without significant differences (P=0.1). When comparing all kidneys together, the mean anterior–posterior renal pelvic diameter was 7.1 mm (95% confidence interval [CI] 6.4–7.8) in supine and 7.9 (95% CI 7.1–8.7) in prone, with a mean difference between the measurements of 0.83 mm (95% CI 0.3–1.4; P=0.16). Central calyceal and peripheral calyceal dilation were more commonly found in the prone position versus the supine position in both kidneys. Central calyceal dilation was observed in 15 cases in the prone but not in the supine position. In one kidney, it was seen only in the supine but not in the prone position. Overall the urinary tract dilation score differed between positions in 10.3% (15/146) of cases, most of them (14/15) with a higher score in prone compared to the supine position.

Conclusion

Scanning in prone position tends to more frequently show calyceal dilation and a greater size of the anterior–posterior renal pelvic diameter, resulting in higher urinary tract dilation classification scores, with almost perfect interobserver agreement.

Keywords

Children Dilation Infants Position Ultrasound Urinary tract 

Notes

Compliance with ethical standards

Conflicts of interest

None

References

  1. 1.
    Scoutt LM, Burns P, Brown JL et al (2000) Ultrasound evaluation of the urinary tract. In: Pollack HM (ed) Clinical urography, 2nd edn. W.B. Saunders, Philadelphia, pp 388–523Google Scholar
  2. 2.
    Nguyen HT, Benson CB, Bromley B et al (2014) Multidisciplinary consensus on the classification of prenatal and postnatal urinary tract dilation (UTD classification system). J Pediatr Urol 10:982–998CrossRefGoogle Scholar
  3. 3.
    Langer B, Simeoni U, Montoya Y et al (1996) Antenatal diagnosis of upper urinary tract dilation by ultrasonography. Fetal Diagn Ther 11:191–198CrossRefGoogle Scholar
  4. 4.
    Ellenbogen PH, Scheible FW, Talner LB, Leopold GR (1978) Sensitivity of gray scale ultrasound in detecting urinary tract obstruction. AJR Am J Roentgenol 130:731–733CrossRefGoogle Scholar
  5. 5.
    Grignon A, Filion R, Filiatrault D et al (1986) Urinary tract dilatation in utero: classification and clinical applications. Radiology 160:645–647CrossRefGoogle Scholar
  6. 6.
    Fernbach SK, Maizels M, Conway JJ (1993) Ultrasound grading of hydronephrosis: introduction to the system used by the Society for Fetal Urology. Pediatr Radiol 23:478–480CrossRefGoogle Scholar
  7. 7.
    Onen A (2007) An alternative grading system to refine the criteria for severity of hydronephrosis and optimal treatment guidelines in neonates with primary UPJ-type hydronephrosis. J Pediatr Urol 3:200–205CrossRefGoogle Scholar
  8. 8.
    Riccabona M, Avni FE, Blickman JG et al (2008) Imaging recommendations in paediatric uroradiology: minutes of the ESPR workgroup session on urinary tract infection, fetal hydronephrosis, urinary tract ultrasonography and voiding cystourethrography, Barcelona, Spain, June 2007. Pediatr Radiol 38:138–145CrossRefGoogle Scholar
  9. 9.
    Berdon WE, Baker DH, Leonidas J (1968) Advantages of prone positioning in gastrointestinal and genitourinary roentgenologic studies in infants and children. Am J Roentgenol Radium Therapy Nucl Med 103:444–455CrossRefGoogle Scholar
  10. 10.
    Riggs W Jr, Hagood JH, Andrews AE (1970) Anatomic changes in the normal urinary tract betwen supine and prone urograms. Radiology 94:107–113CrossRefGoogle Scholar
  11. 11.
    Fernbach SK, Bernfield JB (1990) Positional variation in the ultrasound appearance of the renal pelvis. Pediatr Radiol 21:45–47CrossRefGoogle Scholar
  12. 12.
    Carrico CW, Zerin JM (1996) Sonographic measurement of renal length in children: does the position of the patient matter? Pediatr Radiol 26:553–555CrossRefGoogle Scholar
  13. 13.
    De Sanctis JT, Connolly SA, Bramson RT (1998) Effect of patient position on sonographically measured renal length in neonates, infants, and children. AJR Am J Roentgenol 170:1381–1383CrossRefGoogle Scholar
  14. 14.
    Nakamura M, Taniguchi N, Kawai F et al (2003) Sonographic measurement of renal length in children: variation associated with body position. J Med Ultrason 30:187–192CrossRefGoogle Scholar
  15. 15.
    Sharma G, Sharma A, Maheshwari P (2012) Predictive value of decreased renal pelvis anteroposterior diameter in prone position for prenatally detected hydronephrosis. J Urol 187:1839–1843CrossRefGoogle Scholar
  16. 16.
    McHugh ML (2012) Interrater reliability: the kappa statistic. Biochem Med 22:276–282CrossRefGoogle Scholar
  17. 17.
    Schaeffer AJ, Kurtz MP, Logvinenko T et al (2016) MRI-based reference range for the renal pelvis anterior-posterior diameter in children ages 0-19 years. Br J Radiol 89:20160211CrossRefGoogle Scholar
  18. 18.
    Rickard M, Easterbrook B, Kim S et al (2017) Six of one, half a dozen of the other: a measure of multidisciplinary inter/intra-rater reliability of the Society for Fetal Urology and urinary tract dilation grading systems for hydronephrosis. J Pediatr Urol 13:80.e1–80.e5CrossRefGoogle Scholar
  19. 19.
    Back SJ, Christopher Edgar J et al (2018) Rater reliability of postnatal urinary tract dilation consensus classification. Pediatr Radiol 48:1606–1611CrossRefGoogle Scholar
  20. 20.
    Nelson CP, Lee RS, Trout AT et al (2019) Interobserver and intra-observer reliability of the urinary tract dilation classification system in neonates: a multicenter study. J Urol 201:1186–1192CrossRefGoogle Scholar
  21. 21.
    Chung EM, Soderlund KA, Fagen KE (2017) Imaging of the pediatric urinary system. Radiol Clin N Am 55:337–357CrossRefGoogle Scholar
  22. 22.
    Nelson CP, Lee RS, Trout AT et al (2019) The association of postnatal urinary tract dilation risk score with clinical outcomes. J Pediatr Urol 19:30123–30128Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Radiology,Children’s Hospital of PhiladelphiaPhiladelphiaUSA
  2. 2.Department of RadiologyBeth Israel Deaconess Medical CenterBostonUSA
  3. 3.Department of Radiology,College of Health SciencesAddis AbabaEthiopia
  4. 4.Department of Radiology and Radiological Sciences,Johns Hopkins School of Medicine,BaltimoreUSA
  5. 5.Perelman School of Medicine,University of Pennsylvania,PhiladelphiaUSA

Personalised recommendations