Evaluation of the Communication Between Arachnoid Cysts and Neighboring Cerebrospinal Fluid Spaces by T2W 3D-SPACE With Variant Flip-Angle Technique at 3 T

Arachnoid cyst in the pediatric patient: What the radiologist needs to know

Arachnoid cysts are the most common incidentally discovered intracranial lesions on imaging and the most common cystic intracranial lesions. They may be developmental or secondary. A relative lack of recent literature and any comprehensive radiological review on arachnoid cysts has led to a general lack of awareness among radiologists of symptomatic or complicated arachnoid cysts. This is particularly concerning in pediatric patients. While arachnoid cysts are asymptomatic in most cases, they can cause clinical symptoms in a minority of cases, especially when they occur in unusual sites. These include intraventricular locations where they may cause hydrocephalus, the basal cisterns where they may compress cranial nerves, the cerebellopontine angle where they have to be differentiated from a number of cystic lesions, the cavum septum pellucidum or cavum velum interpositum, the choroid fissure where they can entrap the temporal horn and compress the hippocampus, the posterior fossa where they need to be differentiated from other posterior fossa cystic lesions, and within the spinal canal where there is a concern for cord or nerve root compression. Larger cysts are more prone to complications such as mass effect, hemorrhage, and rupture. Hemorrhage and rupture often present with acute symptoms. Ruptured cysts lose their characteristic imaging appearance and can mimic several ominous pathologies. It therefore becomes vital to accurately diagnose these cases as complications of pre-existing arachnoid cysts for appropriate management. A detailed review of all diagnostic imaging aspects of arachnoid cysts will help fill in the existing information void on this important entity.

Postoperative patency assessment of Cystocisternostomy and Cystoventriculostomy stomas in cases with Arachnoidal cyst

PURPOSE

The goal of this study was to determine stoma and flow patency with 3D SPACE T2 and 3D CISS sequences in cases with cystocisternostomy or cystoventriculostomy.

METHODS

A total of sixty three patients (total 106 MRI examinations) with endoscopic cystocisternostomy or cystoventriculostomy of arachnoid cyst underwent 1.5-3 T MRI to determine flow patency between June 2007 and April 2018. Postoperative results, the patients' clinic and arachnoid cyst volume were used to confirm stoma and flow patency in MRI.

RESULTS

The stoma was open and functional in forty three patients. Minimal flow was detected in five patients. Fifteen patients with closed stoma (total 17 MR images) were evaluated with the clinician. Patients' clinic, physical examination, and growth (for pediatric patients) were evaluated. Three of fifteen patients were re-operated. Operative findings and postoperative follow-up MR imaging findings were correlated with our preoperative MRI results. The findings were in compliance in both groups (operated-non-operated groups).

CONCLUSION

3D SPACE T2 and 3D CISS are effective sequences in addition to other routine conventional sequences to evaluate stoma and flow patency.