Purpose or Case Report: Ventricular shunt failures are common with as many as 40% failing by 1 year and 70% by 10 years. Approximately 15% of these shunt failures are related to shunt disconnections. The typical presenting symptoms of shunt malfunction are nonspecific and include nausea, vomiting, and altered consciousness; therefore, imaging is critical for diagnosis. Conventional radiographs can be used to identify shunt disruption although they can have limited sensitivity. Most children with suspected shunt dysfunction will also undergo CT or MR imaging to evaluate ventricular sizes. In addition, the integrity of the shunt system within the field of view on head CT can be assessed in detail; however, subtle shunt disconnections or fractures can still be difficult to detect on multiplanar CT images. Volume rendered CT images of the shunt apparatus can be used to improve the detection of subtle shunt disruptions
Methods & Materials: In this educational exhibit, we describe the technique for generating volume rendered images of ventricular shunt systems within the field of view on head CT scans. To optimally assess shunt integrity on volume rendered images, careful attention to window and level settings is necessary. We demonstrate the benefit of volume rendered CT images for improving detection of shunt disruption by reviewing several cases with subtle disconnections or malpositions, and compare the volume rendered images to the corresponding multiplanar CT or radiograph images. In addition, we highlight possible interpretive pitfalls when using volume rendered CT images in the evaluation of ventricular shunt malfunction.
Results:
Conclusions: Volume rendered CT images of ventricular shunt systems should be considered to improve the detection of shunt catheter disruption.