Evaluation of the Communication Between Arachnoid Cysts and Neighboring Cerebrospinal Fluid Spaces by T2W 3D-SPACE With Variant Flip-Angle Technique at 3 T Oktay Algin, MD Purpose: Phase-contrast cine magnetic resonance imaging (PC-MRI) is a widely used technique for determination of possible communication of arachnoid cysts (ACs). Three-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolutions (3D- SPACE) technique is a relatively new method for 3D isotropic scanning of the entire cranium within a short time. In this research, the usage of the 3D-SPACE technique in differentiation of communicating or noncom- municating type ACs was evaluated. Materials and Methods: Thirty-five ACs in 34 patients were retro- spectively examined. The 3D-SPACE, PC-MRI, and contrast material– enhanced cisternography (if present) images of the patients were analyzed. Each cyst was described according to cyst size/location, third ventricle di- ameter, Evans index, and presence of hydrocephalus. Communication was defined as absent (score 0), suspected (score 1), or present (score 2) on each sequence. Results of PC-MRI or cisternography (if available) exami- nations were used as criterion standard techniques to categorize all cysts as communicating or noncommunicating type. The results of 3D-SPACE were compared with criterion standard techniques. The comparisons be- tween groups were performed using Mann-Whitney and Fisher exact tests. Results: For demonstration of communication status of the cysts, crite- rion standard test results and 3D-SPACE findings were almost in perfect harmony (κ[95% confidence interval: 0.94]; P < 0.001). When evaluating the communicative properties, 3D-SPACE findings correlated with other final results at a rate of 97%. There is a positive correlation with third ven- tricular diameters and Evans index for all patients (r = 0.77, P < 0.001). For other analyzed variables, there is no significant difference or correlation be- tween the groups. Conclusions: The 3D-SPACE technique is an easy, useful, and noninva- sive alternative for the evaluation of morphology, topographical relation- ships, and communication status of ACs. Key Words: magnetic resonance imaging, intracranial arachnoid cyst, cisternography, phase-contrast cine magnetic resonance imaging, cerebro-spinal fluid, three-dimensional sampling perfection with application-optimized contrasts using different flip-angle evolutions (J Comput Assist Tomogr 2018;00: 00–00) T he incidences of arachnoid cysts (ACs) have increased par- allel to the increase in the application of cross-sectional im- aging. 1,2 However, clinical management of ACs and types of the surgical procedures are very controversial issues. 2,3 In general, symptomatic noncommunicating-type ACs were recommended for surgical treatment. 2–4 In addition, focal brain damage, hydrocephalus, and/or raised intracranial pressure are other indi- cations for surgical intervention. 3 Accurate assessment of cyst communication with surround- ing cerebro-spinal fluid (CSF) spaces would help clinicians make surgical decisions in patients with AC. 4 In some cases, hydrody- namic characteristics of the CSF flow within the cysts may be more meaningful than clinical symptoms for surgical decision. 4 Routine magnetic resonance imaging (MRI) techniques are insufficient in determining the communicative properties of the AC with surrounding CSF; thus, contrast material–enhanced cis- ternography or phase-contrast cine magnetic resonance imaging (PC-MRI) are used to understand the hydrodynamics of the cyst and determine the possible communication with surrounding CSF. Contrast material–enhanced cisternography is an invasive method and carries the risk of meningitis, intracranial hypotension, encephalopathy, or seizures. 5 On the other hand, PC-MRI requires ex- perience during acquisition and reporting the sequences. In addition, PC-MRI can lead to many false-positive or negative conclusions in inexperienced hands. 1,4,5 For these reasons, both tests have limited uses in daily clinical practice. As a result, there is no easy, reliable, and noninvasive test for accurate diagnosis of ACs. Therefore, ACs do not make any problem just in clinical or surgical man- agement, but ACs can create a problem during diagnosis of communication status because of the reasons mentioned above. Our previous studies showed that T2-weighted (T2W) three- dimensional sampling perfection with application-optimized con- trasts using different flip-angle evolutions (3D-SPACE) with variant flip-angle (VFAM) technique can be used alone for accu- rate evaluation of CSF-containing spaces of the head without the need for an additional sequence, invasive intervention, and/or ex- amination within a short time. 6–9 To the best of our knowledge, its effectiveness in the evaluation of ACs and communication status with CSF spaces has not been established yet. The purpose of this retrospective preliminary research study is to evaluate the role of T2W 3D-SPACE with VFAM method at 3 T MR devices for de- tection of communication between intracranial ACs and adjacent CSF-containing spaces. MATERIALS AND METHODS Study Population Between February 2009 and August 2016, 34 patients (16 males, 18 females; age range: 3–69, median age: 26 years) with AC were included in this retrospective study, which was approved by our institutional review board. Pregnant women and patients with cardiac pacemakers, metallic implants, or claustrophobia were excluded from the study. In addition, 1 patient had 2 intracra- nial ACs. As a result, 35 intracranial ACs of 34 patients were in- cluded in the study. Written informed consent was obtained from all participants. The 3D-SPACE and PC-MRI examinations were performed for all patients. In addition, cisternography tests From the Department of Radiology, Medical Faculty, Yildırım Beyazit University; and National MR Research Center (UMRAM), Bilkent University, Ankara, Turkey. Received for publication September 24, 2017; accepted March 7, 2018. Correspondence to: Oktay Algin, MD, Department of Radiology, Ataturk Training and Research Hospital, 06050 Ankara, Turkey (e‐mail: droktayalgin@gmail.com). The author declares no conflict of interest. This work was primarily carried out in the Department of Radiology, Ataturk Training and Research Hospital, Ankara, Turkey. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/RCT.0000000000000751 ORIGINAL ARTICLE J Comput Assist Tomogr • Volume 00, Number 00, Month 2018 www.jcat.org 1 Copyright © 2018 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. This paper can be cited using the date of access and the unique DOI number which can be found in the footnotes.