1054 Pediatr Nephrol (2010) 25:1049–1056 wall. DSA is usually performed under general anaesthesia in children, especially when endovascular interventions such as angioplasty are planned [43]. Questions (Answers appear following the reference list) Patient selection The results of CTA and MRA are improving with time. This is partly due to improved interpretation, but it is due mainly to technical advances. Despite the high-quality images produced, significant RVD (and, especially, intra- renal arterial disease) is still often missed when these modalities are used. Therefore, we would suggest that the best possible images be obtained, using DSA for patients in whom there is a strong suggestion of RVD, such as those with poorly controlled blood pressure on at least two anti- hypertensive agents and/or those patients with syndromes associated with RVD (such as neurofibromatosis type 1, tuberous sclerosis, Williams’ syndrome and Marfan’s syndrome) (Table 2) [3]. Summary Neither US nor post-captopril isotope renography have high enough sensitivity to exclude treatable RAS as a cause of hypertension in children. Although CTA and MRA produce aesthetically pleasing images of the renal arteries, both will also miss a significant proportion of children with poten- tially treatable RVD as well as their intra-renal arterial disease (Table 1). Imaging requirements in hypertension are different for children than for adults, because children’s arteries are smaller and the distribution of arterial disease is different. Therefore, our current opinion is that every child with a reasonably strong suggestion of RVD should undergo DSA. Table 2 Clinical and laboratory signs that indicate an increased chance of renovascular disease [3] (BP blood pressure) Clinical or laboratory sign 1. Very high BP 2. Secondary symptoms of high BP - including cerebral symptoms, cardiac failure and facial palsy 3. Hypertension not controlled on >2 antihypertensive drugs 4. Diagnosis of a syndrome with a higher risk of vascular disease, such as neurofibromatosis, tuberous sclerosis and Williams’ syndrome 5. Signs of vasculitis, in particular Takayasu disease 6. Known or suspected previous vascular insult, such as renal artery thrombosis or umbilical artery catheterisation 7. Bruit heard over the renal artery or arteries 8. Elevated peripheral plasma renin or moderate hypokalaemia 1. What proportion of childhood hypertension is cause by RVD? 2. 3. 4. 5. a. 1% b. 2% c. 10% d. 25% e. 50% What is the commonest cause of renovascular hyper- tension in childhood? a. Atherosclerosis b. Fibromuscular dysplasia c. Mid-aortic syndrome d. Takayasu’s arteritis e. Trauma Which of the following is not a syndrome associated with RVD? a. Edward’s syndrome b. Marfan’s syndrome c. Neurofibromatosis type 1 d. Tuberous sclerosis e. Williams’ syndrome What is currently the gold standard investigation in the diagnosis of RVD? a. CT angiography b. Digital subtraction angiography c. Duplex ultrasonography d. MR angiography e. Pre- and post-captopril 99mTc DMSA and 99mTc MAG-3 What are the concerns in the use of gadolinium for MRA in children with RVD and chronic renal impairment? a. Contrast medium remains in the heart and does not delineate renal vasculature b. The cost of contrast material c. Images are of poorer quality due to renal dysfunction d. The risk of nephrogenic systemic fibrosis e. Timing of scan has to be prolonged to hours after administration of contrast agent References 1. Gill DG, de Mendes CB, Cameron JS, Joseph MC, Ogg CS, Chantler C (1976) Analysis of 100 children with severe and persistent hypertension. Arch Dis Child 51:951–956