Case Author(s): Thomas H. Vreeland, MD / J. Wallis , 07/17/94 . Rating: #D2, #Q3

Diagnosis: Normal CSF shunt scintigraphy

Brief history:

The patient is being evaluated for possible shunt malfuntion.

Images:

View main image(cs) in a separate image viewer

Full history/Diagnosis is available below


Diagnosis: Normal CSF shunt scintigraphy

Full history:

This patient is a four year old boy with a history of resection of a posterior fossa tumor and place- ment of a ventriculo-peritoneal shunt catheter system two years ago. The patient now presents with nausea, vomiting, headache and lethargy. The patient is being evaluated for possible shunt malfunction.

Radiopharmaceutical:

0.5 mCi Tc-99m DTPA in less than 0.2 ml.

Note: Tc-99m DTPA is not specifically approved for intrathecal administration, and accordingly meets the phamacopoeial bacterial endotoxin standard for an intravenously administered drug. Because the CNS is more sensitive to endotoxins, only < 10% of the volume of a Tc- 99m DTPA vial should be injected for this study whenever the radiopharmaceutical is to be refluxed into the ventricular system. In this case, there was no intention to reflux tracer into the ventricles.

Findings:

There is normal progression of tracer down the distal shunt catheter system, with free spillage of tracer activity into the peritoneal cavity by 15 minutes. There is no reflux into the ventricles.

Discussion:

(1) At our institution, the Neurosurgeon will inject the radiopharmaceutical directly into the shunt catheter reservoir system. The total volume of tracer is 0.2 to 0.4 ml., injected with a tuberculin syringe. A small volume is used to avoid disturbing flow in the system. The patient is usually imaged in the supine position. Dynamic one minute images are acquired, and additional analog images are acquired.

(2) The normal transit time is approximately 10-20 minutes. A transit time of more than 30 minutes is abnormal. Althought the proximal limb is not evaluated directly, if there is normal flow through the system then the proximal limb must be patent.

(3) Removal of fluid (e.g. for culture) is avoided, as it may decrease the pressure below that needed to open the shunt valve and may artifactually produce an abnormal test result.

(4) If no flow is seen, placing the patient in an erect position will slightly increase the forward pressure and encourage CSF flow.

ACR Codes and Keywords:

References and General Discussion of CSF Shunt Scintigraphy (Anatomic field:Skull and Contents, Category:Organ specific)

Search for similar cases.

Edit this case

Add comments about this case

Read comments about this case

Return to the Teaching File home page.


Case number: cs001

Copyright by Wash U MO