We reviewed our experience with shuntograms to establish technical cri
teria that would optimize the reliability of this test in managing pat
ients with shunt malfunction, Methods: Fifty-six shuntograms were perf
ormed in 47 children presenting with symptoms of shunt malfunction not
elucidated by conventional radiological examination. Shuntograms were
performed by injecting 0.5 mi (99m)-DTPA in the reservoir of the shun
t. Results: There were 22 shuntograms in which ventricular reflux occu
rred and the entire shunt system was visualized, At surgery, three pat
ients in this group presented partial obstruction of the ventricular a
nd/or peritoneal catheter. A second group of patients had 15 shuntogra
ms that showed normal proximal reflux but abnormal distal drainage. Te
n patients in this group presented distal obstruction or fracture, val
ve dysfunction or peritoneal adhesions at surgery. A third group of pa
tients with 19 shuntograms exhibited no proximal reflux. At surgery, t
welve had an obstructed ventricular catheter and the last case showed
overdrainage. Symptoms of nonsurgical patients abated spontaneously, C
onclusion: The shuntogram is a useful procedure in the management of p
atients presenting with shunt-related problems, For consideration as a
normal result, a shuntogram must exhibit ventricular reflux, the shun
t system must be entirely visualized and the isotope must diffuse unif
ormly in the peritoneal cavity, Whereas rapid radionuclide clearance i
s a useful parameter in eliminating a distal obstruction, it is a misl
eading sign for proximal blockage, Absence of ventricular reflux is hi
ghly suggestive of proximal reflux. Implicit to this conclusion is the
fact that the presence of a reservoir proximal to the valve greatly f
acilitates the performance and interpretation of a shuntogram.