-  Normal salt diet in previous 2 days. Same day of test, patient should drink about 10 ml/kg liquids to keep normal hydration and diuresis.

-  In cases suspected of renovascular hypertension, perform a baseline and captopril renogram in same or separate days. If possible, withdraw angiotensin-converting enzyme (ACE) inhibitors for 24 h to 96 h depending on the half life of each one and diuretics for 24 h.. If the patient presents on ACE inhibitors, the procedure may be performed right away and later according to the result complete with the baseline scan. Probably this variation in the standard protocol could have lower sensitivity. Calcium channel blockers may cause a bilateral false positive response, so if possible should be withdrawn. Captopril 50 mg orally is given 1 h. before the renogram and compared to baseline. Patient should avoid eating solid food in previous 4 h to have better captopril absorption. Record blood pressure before captopril administration and every 15 min for 1 h, to be included in the report.

-  If indicated the renogram can be performed with an open bladder catheter to diminish back-pressure flow.

- In the patient with kidney transplant, similar directions to the described above are to be used. In addition, it is important to make sure diuretics may be injected if the patient is in first days after surgery. Likewise, if there is a bladder catheter to ask if it needs to be occluded during the acquisition.

References:

1  Estorch M. Detección de las Cicatrices Renales y Valoracion de la Nefropatia Obstructiva, p: 411-418; Orellana P et al. Reflujo Vesicoureteral, p: 419-424 in: Medicina Nuclear Aplicaciones Clínicas. Eds: I. Carrio - P. González. Editorial Masson, Barcelona España, 2003.

2  Mandell G. A. et al., Procedure Guideline for Renal Cortical Scintigraphy in Children 2.0 Society Of Nuclear Medicine Procedure Guidelines Manual 2001-2002; 157-160.

3 Taylor A. et. al.. Consensus Report on ACE Inhibitor Renography Detecting Renovascular Hypertension. J Nucl Med 1996; 37:1876-1882.