Clinical value of radionuclide shuntography by qualitative methods in hydrocephalic adult patients with suspected ventriculoperitoneal shunt malfunction

To determine the clinical value of radionuclide shuntography in the evaluation of adult hydrocephalic patients with suspected ventriculoperitoneal (V-P) shunt malfunction. All adult patients who underwent Tc-99m diethylenetriamine pentaacetic acid shuntographic scans at Far Eastern Memorial Hospital between August 2005 and December 2015 were included. Shuntographic results were visually evaluated in a simple qualitative manner: prompt flow that reached the peritoneum on 30-minute early images and diffuse peritoneal tracer distribution on 2-hour delayed images were interpreted as nonobstructive shunt flow. Partial dysfunction was diagnosed as scintigraphic findings between no obstruction and complete obstruction (where complete malfunction indicated no peritoneal distribution on delayed images). The results were correlated with the clinical outcomes and surgical results within 30 days. Diagnostic sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were also calculated. A total of 93 scans in 69 patients with suspected V-P shunt malfunction were analyzed. Sixty-two scans were interpreted as abnormal, including complete (n = 26, 41.9) distal obstruction, partial (n = 35, 56.5) distal dysfunction, and miscellaneous (n = 1, 1.6, cerebrospinal fluid leak). The Se and Sp were 83.0% and 55.0%, respectively, and PPV, NPV, and accuracy were all 71.0%. Twenty-five patients (28 scans) underwent surgical revision, and the results were highly concordant with the imaging findings (Se, 92.0%; Sp, 100.0%; PPV, 100.0%; NPV, 60.0%; and accuracy, 92.9%). Radionuclide shuntography provides useful information in adult patients with V-P shunt malfunction and could be used to guide further surgical intervention.