Introduction: The fast imaging employing steady state acquisition (FIESTA) sequence provides images of fluid filled structures with very short acquisition times. It uses the T2 steady state mechanism to provide a high signal-to-noise ratio for anatomic detail that is ideal for the identification of small structures in the ventricular system. Presented are two cases in which the FIESTA sequence revealed intraventricular cysts which were not apparent on traditional MRI/CT imaging studies demonstrating its application in the routine work up of newly diagnosed triventricular hydrocephalus of unknown origin.
Methods: Two patients, ages 4 and 6, presented to the emergency room with lethargy and emesis. Initial CT head revealed triventricular hydrocephalus without obvious additional pathology. Subsequent contrasted MRI studies (including T1, T2, FLAIR, and DWI sequences) failed to show any obstructive lesions in the ventricular system (Figures 1A, 1B). The FIESTA sequence, however, demonstrated a distinct cystic lesion originating in the third ventricle with resultant obstruction of the aqueduct of Sylvius. In both cases, neuroendoscopic tools were utilized to directly visualize (Figure 2) and resect the ventricular cysts (Video).
Results: Following surgical intervention the patient’s symptoms completely resolved. Serial imaging studies immediately after surgery and in outpatient follow-up showed resolution of hydrocephalus.
Conclusions: We conclude that the FIESTA sequence provides vital data in the initial workup and ultimate treatment of newly diagnosed triventricular hydrocephalus of unknown etiology.
Patient Care: Highlight imaging modalities that are appropriate for the diagnosis and treatment of triventricular hydrocephalus
Learning Objectives: By the conclusion of this session, participants should be able to understand the importance of the FIESTA sequence in identifying intraventricular pathology.