Advertisement

Use of Contrasted Computerized Tomography as a Surrogate for Nuclear Medicine Renogram to Categorize Renal Function in the Setting of Ureteropelvic Junction Obstruction

      Objective

      To use basic measurements on contrasted computerized tomography (CT) to reliably determine whether a kidney with ureteropelvic junction obstruction (UPJO) is definitively functional (≥30% differential renal function [DRF]) or nonfunctional (≤10% DRF), obviating the need for nuclear medicine renogram (RG) to determine DRF.

      Methods

      This is a single institution, retrospective cohort of patients diagnosed with UPJO who underwent either pyeloplasty or nephrectomy between December 2004 and December 2014. Included patients had both preoperative mercaptoacetyltriglycine RG and contrasted CT within 180 days of each other. Patients with stents or nephrostomy tubes were excluded.

      Results

      A total of 49 patients were included. The strongest correlation between differential CT measurements and DRF on RG existed by multiplying the cortical area by the average cortical Hounsfield units (Pearson's r = 0.90, P < .001). Using an equation derived from linear regression and cutoff values generated by receiver operator curve (ROC) analysis, CT equation-estimated DRF values of ≥40% and ≤10% correlated with “definitively functional” RG values of ≥30% (100% specificity) and with “definitively nonfunctional” RG values of ≤10% (100% specificity), respectively. In 30 out of 49 cases, CT could have replaced RG.

      Conclusion

      RG is the gold standard in determining quantitative DRF. However, the treatment algorithm for a kidney with symptomatic UPJO hinges on categorized function: “functional” (repair) or “nonfunctional” (remove). Appropriate measurements on contrasted CT can categorize definitively functional or nonfunctional kidneys with UPJO, negating the need for RG to obtain DRF in a majority of cases. This study design favors real-world application with potential to reduce medical expenditure and delay in definitive treatment.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Urology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Koff S.A.
        Pathophysiology of ureteropelvic junction obstruction. Clinical and experimental observations.
        Urol Clin North Am. 1990; 17: 263-272
        • Shafik A.
        • Al-Sherif A.
        Ureteropelvic junction: a study of its anatomical structure and function. Ureteropelvic junction sphincter?.
        Eur Urol. 1999; 36 (Discussion156–7): 150-156
        • Carr M.C.
        • Casale P.
        Anomalies and surgery of the ureter in children.
        in: Campbell-Walsh Urology 10th Edition Review. Elsevier Inc, Philadelphia, PA2012
        • Desai M.M.
        • Hogarty N.
        Contemporary surgical management of adult ureteropelvic junction obstruction.
        AUA Update Series. 2007; 26 (Available at): 1-12
        • Tasca A.
        • Barulli M.
        • Artibani W.
        • et al.
        Role of the diuresis renogram in the study of the pelviureteric junction.
        Eur Urol. 1985; 11: 374-377
        • Harris P.A.
        • Taylor R.
        • Thielke R.
        • Payne J.
        • Gonzalez N.
        • Conde J.G.
        Research electronic data capture (REDCap)—a metadata-driven methodology and workflow process for providing translational research informatics support.
        J Biomed Inform. 2009; 42: 377-381https://doi.org/10.1016/j.jbi.2008.08.010
        • Feder M.T.
        • Blitstein J.
        • Mason B.
        • Hoenig D.M.
        Predicting differential renal function using computerized tomography measurements of renal parenchymal area.
        J Urol. 2008; 180: 2110-2115https://doi.org/10.1016/j.juro.2008.07.057
        • Morrisroe S.N.
        • Su R.R.
        • Bae K.T.
        • et al.
        Physiology/medical disease differential renal function estimation using computerized tomography based renal parenchymal volume measurement.
        Juro. 2010; 183: 2289-2293https://doi.org/10.1016/j.juro.2010.02.024
        • Ramaswamy K.
        • Marien T.
        • Mass A.
        • Stifelman M.
        • Shah O.
        Simplified approach to estimating renal function based on computerized tomography.
        Can J Urol. 2013; 20: 6833-6839
        • Martinez-Suarez H.J.
        • Durso T.
        • Kadlec A.O.
        • Gupta G.N.
        • Farooq A.V.
        • Turk T.
        Three-dimensional renal parenchymal volume as a surrogate for renal function estimation in obstructed kidneys undergoing surgical repair.
        J Endourol. 2015; 29: 630-633https://doi.org/10.1089/end.2014.0232
        • Maynes L.J.
        • Levin B.M.
        • Webster T.M.
        • Baldwin D.
        • Herrell S.D.
        Measuring the true success of laparoscopic pyeloplasty.
        J Endourol. 2008; 22: 1193-1198https://doi.org/10.1089/end.2008.0163
        • Hsi R.S.
        • Holt S.K.
        • Gore J.L.
        • Harper J.D.
        Trends in followup imaging after adult pyeloplasty.
        J Urol. 2014; 191: 1357-1362https://doi.org/10.1016/j.juro.2013.12.052
        • Ng C.F.
        • Chan L.W.
        • Wong K.T.
        • Cheng C.W.
        • Yu S.C.H.
        • Wong W.S.
        Prediction of differential creatinine clearance in chronically obstructed kidneys by non-contrast helical computerized tomography.
        Int Braz J Urol. 2004; 30 (Discussion 108): 102-107
        • Breau R.H.
        • Clark E.
        • Bruner B.
        • et al.
        A simple method to estimate renal volume from computed tomography.
        Can Urol Assoc J. 2013; 7: 189-192https://doi.org/10.5489/cuaj.1338
        • Othman S.
        • Al-Hawas A.
        • Al-Maqtari R.
        Renal cortical imaging in children: 99mTc MAG3 versus 99mTc DMSA.
        Clin Nucl Med. 2012; 37: 351-355https://doi.org/10.1097/RLU.0b013e3182443f68
        • Smokvina A.
        • Grbac-Ivanković S.
        • Girotto N.
        • Dezulović M.S.
        • Saina G.
        • Barković M.M.
        The renal parenchyma evaluation: MAG3 vs. DMSA.
        Coll Antropol. 2005; 29: 649-654