Non-Invasive Contrast Enhanced Electron Beam Tomography: A Three Dimension Imaging Adjunctive Test To Detect Renal Vascular and A-V Fistula Graft Abnormalities.

Abstract

Electron beam tomography (EBCT) is a relatively new technology with several potential advantages over traditional CT such as fast acquisition time, less exposure to radiation, less sedation and volume of dye, and better 3D visualization. A retrospective study was done to assess the use of 3D EBCT to detect renal vascular abnormalities and patency of arteriovenous-fistula (A-VF) and arteriovenous-graft (A-VG). EBCT was done in 7 children (age 3–18 year, mean age 10.8 years). All had hypertension (> 95%) and high rennin levels. Four of the patients (group I) had normal renal function. One patient (group II) was 20 days post enblock renal transplantation with ascites, hypertension and renal dysfunction. Two patients (group III) had end-stage renal disease, hypertension, and AV-F and AV-G. One of these patients had SLE and difficult IV access. In group I, 2/4 had left ventricular hypertrophy, eye and CNS changes. MAG-3 renal scan (RSC) and renal ultrasound (RUS) were normal in 2/4 group I patients. In group I, 2/4 EBCT showed unilateral renal artery stenosis: one of these children had decreased velocity in one kidney by RUS and the other child had possible renal artery stenosis by RSC. One child in group I with abnormal RUS suggestive of RAS did not have RAS by EBCT and traditional angiography. In group II, patient with transplant, EBCT showed normal renal vasculature and ureterovesicle anastomoses without RAS or leak respectively. In group III, the SLE patient had thrombosis of the inferior vena cava and renal veins and the other patient had patent A-VF with dilated vessels contrary to US finding of thrombosis. In conclusion, EBCT with its non invasive, maximum intensity projection and 3D images, less radiation and acquisition time is a useful adjunct test to detect RAS and AV-F, AV-G and transplant vascular thrombosis/stenosis in children.