Noncontrast CT Head for Shunt Evaluation

Primary Imaging Approach

The American College of Radiology recommends noncontrast CT head as the first-line test for evaluating suspected shunt malfunction, as it rapidly assesses ventricular size, mass effect, and hydrocephalus 1, 2
Noncontrast CT head evaluates key findings including progressive mass effect or increasing edema, hydrocephalus or ventricular enlargement, and new or enlarging intracranial hemorrhage 1, 2

Contrast-enhanced CT does not add significant value over noncontrast CT for shunt evaluation in the acute setting 2
The American College of Radiology Appropriateness Criteria rate CT head with contrast as "usually not appropriate" (rating 3/9) for evaluating acute intracranial pathology including hydrocephalus 3, 4
Contrast is only considered when there is specific clinical concern for intracranial infection, tumor progression, or inflammatory conditions 1

Obtain noncontrast CT head first to assess ventricular size and acute intracranial pathology, as recommended by the American College of Radiology 1, 2
Reserve contrast-enhanced imaging for cases where infection, tumor, or inflammatory process is specifically suspected as the cause of symptoms, as suggested by the American College of Radiology 1, 2