title: Detection of ventricular shunt malfunction in the ED: relative utility of radiography, CT, and nuclear imaging.
abstract: The study objective was to determine the relative diagnostic utility of the radiographic shunt series (SS), head computed tomography (CT), and nuclear imaging performed in our Emergency Department (ED) for evaluating ventricular shunt malfunction. We retrospectively reviewed medical records, head CT (if performed), and nuclear imaging (if performed) for all ED patients with suspected shunt malfunction from 2002 to 2007 who underwent plain film shunt evaluation (296 cases/186 individuals) to determine if surgical shunt revision was performed. Logistic regression analysis was applied. Four percent (12/296) of radiographic SS were abnormal. Only 0.3% (1/296) underwent surgical revision in the absence of an abnormal head CT or nuclear imaging. Eighteen percent (51/282) of head CT exams were positive and 19% (24/128) of nuclear imaging exams were positive for shunt malfunction. Twenty-three percent (67/296) underwent surgical shunt revisions. Statistical analysis demonstrated that SS evaluation was not significantly associated with surgical shunt revision (OR 0.92; 95% CI, 0.7-1.2; p=0.47). Head CT demonstrated a significant association with surgical revision (OR 1.4; 95% CI, 1.2-1.5; p<0.001), as did nuclear imaging (OR 1.4; 95% CI, 1.2-1.6; p<0.001). Patients with suspected ventricular shunt malfunction frequently require surgical revision. Abnormal radiographic SS was not associated with progression to surgical shunt revision, whereas abnormal head CT and abnormal nuclear imaging were significantly associated with surgical revision. We conclude that radiographic SS in the ED is of low diagnostic utility and that patients with suspected shunt malfunction should instead initially undergo CT and/or nuclear imaging.
authors.affiliation: Department of Radiology, University of Washington, 1959 Pacific Street, Seattle, WA 98195-7117, USA. blehnert@u.washington.edu
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Lehnert
authors.forename: Habib
authors.initials: H
authors.lastname: Rahbar
authors.forename: Annemarie
authors.initials: A
authors.lastname: Relyea-Chew
authors.forename: David H
authors.initials: DH
authors.lastname: Lewis
authors.forename: Michael L
authors.initials: ML
authors.lastname: Richardson
authors.forename: James R
authors.initials: JR
authors.lastname: Fink
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004636:Emergency Service, Hospital; D004868:Equipment Failure; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*