Phase-contrast MRI and 3D-CISS versus contrast-enhanced MR cisternography for the detection of spontaneous third ventriculostomy

Spontaneous third ventriculostomy in patients undergoing fetal surgery for myelomeningocele correction

INTRODUCTION

Spontaneous third ventriculostomy (STV) is characterized by the spontaneous rupture of one of the ventricle walls due to increased pressure in the third ventricle caused by obstructive hydrocephalus. Clinically, STV results in resolution of signs and symptoms of intracranial hypertension and head circumference stabilization. No spontaneous STV cases in patients with myelomeningocele have been reported in the literature. The objective of this study was to report three cases of STV in patients with type 2 Chiari malformation who underwent intrauterine treatment.

CASE PRESENTATION

All patients presented clinically with increased head circumference during outpatient follow-up. Only one patient required a ventriculoperitoneal shunt implantation. The other patients did not require further intervention.

CONCLUSION

STV is a rare entity that is difficult to diagnose and should always be suspected in spontaneous hydrocephalus resolution, especially in early childhood. STV is not synonymous with hydrocephalus resolution.

Case report: Flattening of the tectal plate in obstructive hydrocephalus with auto-ventriculostomy

BACKGROUND

Obstructive hydrocephalus in adulthood can be caused by stenosis in the aqueductal area. Chronic changes lead to a dilatation of the lateral ventricles and ballooning of infratentorial recesses. In rare cases a rupture of the floor of the third ventricle (so-called spontaneous ventriculostomy) has been described in the literature.Case presentation: We present two cases of chronic obstructive hydrocephalus due to aqueductal stenosis in adult patients. Magnetic resonance imaging included phase-contrast-imaging and revealed significant flow through the floor of the third ventricle in keeping with spontaneous ventriculostomy. In addition to other typical changes associated with chronic hydrocephalus, a distinct flattening of the tectal plate could be identified in one case.

CONCLUSION

We present two cases of spontaneous ventriculostomy in patients with chronic hydrocephalus. To our knowledge, flattening of the tectal plate has not yet been described in the literature and may be caused by continuous cerebrospinal fluid-pulsation.

Usefulness of postoperative ventriculography and intracranial pressure monitoring following endoscopic third ventriculostomy

PURPOSE

The authors sought to determine whether the insertion of an external ventricular drain (EVD) at the time of surgery to monitor intracranial pressure (ICP) and ventriculography done within the first day following an endoscopic third ventriculostomy (ETV) is of benefit in postoperative patient management.

METHODS

Following IRB approval, ETV procedures done by the senior author between January 1, 2007, and December 31, 2016, were reviewed. Included in a consecutive fashion were all patients who underwent an ETV with placement of an external ventricular drain (EVD) that was preceded preoperatively by an MRI or CT study and followed by a contrast CT ventriculogram within the first postoperative day.

RESULTS

Identified were 72 patients who met the above criteria; however, technical ventriculography failure occurred in 4 (6%) and were eliminated from the analysis. Of the remaining 68 patients, contrasted CSF was seen in the basal cisterns/subarachnoid spaces (SAS) in 66 (97%) indicating a patent ETV and absent in 2 (3%) indicating a non-patent ETV. Of the 66 patients with a patent ETV, 34 (52%) patients were discharged on postoperative days 1 (8), 2 (13), and 3 (13) as their ICPs were not elevated and their clinical symptoms normal. EVDs placed at the time of the ETV recorded raised ICP > 20 cm H₂O in 17/68 (25%) patients for 1 or more days, all of whom had a patent ETV. Because of persistently elevated ICP requiring CSF drainage for control, 4 of these patients were shunted on postoperative days 5, 6, 6, and 10 and 3 with prolonged elevated ICP for 5, 6, and 11 days postoperatively were not shunted as their ICP and symptoms progressively normalized. The remaining 17/68 (25%) patients did not have a postoperative ICP > 20 cm H₂O; 14 were discharged after resolution of symptoms and other clinical factors, 1 was shunted on postoperative day 3 due to persistent symptoms and a consistently large volume of CSF drainage, and 2 had a non-patent ETV with 1 undergoing shunt placement and the other discharged because of the absence of symptoms. The sensitivity of ventriculography was only 13%; however, the specificity was 98% and the accuracy 88%.

CONCLUSION

After reviewing this series, the continued use of a postoperative EVD appears appropriate as the risk is low and it provides ventricular access to control ICP, thereby, improving patients' safety and reducing the need for CSF shunting on an urgent/emergent basis should the ETV prove to be unsuccessful. From our limited series, the usefulness of a 1-day postoperative ETV ventriculogram is less clear and would need confirmation with additional studies.

Optimization of the refocusing flip angle in the characterization of cerebrospinal fluid dynamics using multi-spin echo acquisition cine imaging (MUSACI)

PURPOSE

Multi-spin echo acquisition cine imaging (MUSACI) is a method used for cerebrospinal fluid (CSF) dynamics imaging based on the proton phase dispersion and flow void using 3D multi-spin echo imaging. In a previous study, the refocusing flip angle of MUSACI was set at a constant 80°. We conducted the present study to investigate the preservation the CSF signal intensity even in a long echo train and improve the ability to visualize CSF movement by modifying the refocusing flip angle in MUSACI.

METHODS

The MUSACI images were acquired in 10 healthy volunteers (7 men and 3 women; age range 24-44 years; mean age 29.4 ± 6.2 years) with a 3.0 Tesla MR scanner. Five refocusing flip angle sets were applied: constant 30°, constant 50°, constant 80°, pseudo-steady state (PSS) 50°-70°-100° (PSS50°), and PSS80°-100°-130° (PSS80°). In all sequences, the in-plane spatial resolution was 0.58 × 0.58 mm², and the CSF movement for one heartbeat was drawn at 80-msec intervals. The signal intensity (SI) of CSF in the lateral ventricle, the foramen of Monro, the third ventricle, the fourth ventricle, and the pons was measured on MUSACI. Pearson's correlation coefficient was calculated between the CSF SI and effective echo time (TE; TE_eff) in the lateral ventricle.

RESULTS

Both antegrade and retrograde CSF movements on the midsagittal MUSACI images and the retrograde CSF movement in the foramen of Monro was observed in all sequences with the constant flip angles. A strong reverse correlation between the CSF SI in the lateral ventricle and TE_eff values was observed with constant 30° (r = -0.96, p < 0.01), constant 50° (r = -0.97, p < 0.01) and constant 80° (r = -0.88, p < 0.01). A weak positive correlation was observed with PSS50° (r = 0.28, p = 0.43), and a moderate reverse correlation was observed at PSS80° (r = -0.60, p = 0.07). The SI values of the foramen of Monro, the third ventricle, and the fourth ventricle were significantly lower than that of the lateral ventricle, and those values were higher than that of the pons in both the constant 80° sequence and the PSS 50° sequence.

CONCLUSION

PSS50° could be the optimal flip angle scheme for MUSACI, because the SI changes due to CSF movement and the SI preservation due to a long echo train were large due to the use of the refocusing flip angle method.

Safety of Intrathecal Administration of Gadolinium-based Contrast Agents: A Systematic Review and Meta-Analysis

Background The use of MR cisternography with intrathecal administration of gadolinium-based contrast agents (GBCAs) is limited by a lack of understanding of the relationship between intrathecal GBCA exposure and dose-related adverse events. Purpose To perform a systematic review to establish an understanding of the dose-response relationship of intrathecal GBCAs and to characterize related adverse events, particularly at higher doses. Materials and Methods Medline, Embase, CINAHL, and Central databases were searched for studies reporting intrathecal GBCA use. Data extraction included studies focused on rates and types of adverse events after intrathecal GBCA exposure. A two-tailed independent sample t test statistic was used to evaluate the relationship between GBCA dose and the presence of serious versus nonserious adverse events. Meta-analysis was used to determine the overall incidence of adverse events. Study quality and publication bias were assessed using the modified Newcastle-Ottawa scale and a funnel plot (effect size measured using Hedges' g followed by the Egger test), respectively. Results Fifty-three studies with a total of 1036 patients were included for analysis. The overall rate of adverse events after intrathecal administration of GBCA was 13% (95% confidence interval [CI]: 9.3%, 18%). Meta-analysis revealed moderate heterogeneity (I² = 62%). Serious adverse event rates could not be determined with meta-analysis. They were reported in 10 studies and were primarily neurologic in nature, with two cases of coma-one resulting in death. Serious adverse events were associated with significantly higher GBCA doses when compared with nonserious adverse events (mean difference, 4.5 mmol; 95% CI: 2.3 mmol, 6.6 mmol; P = .008). For serious adverse events, there was no clear dose-dependent increase in severity above 2.0 mmol. Conclusion Overall, intrathecal administration of GBCAs at doses greater than 1.0 mmol are associated with serious neurotoxic complications with relative clinical safety at lower doses. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Kanal in this issue.

Intrathecal use of gadobutrol for gadolinium-enhanced MR cisternography in the evaluation of patients with otorhinorrhea

PURPOSE

Intrathecal gadolinium-enhanced MR cisternography (IGE-MRC) has a high sensitivity to detect accurate localization of cerebrospinal fluid (CSF) leakage in otorhinorrhea patients. Our purpose in this study was to describe our experience in analyzing clinically suspected CSF leakage by IGE-MRC by using gadobutrol with emphasis on its safety and diagnostic performance.

METHODS

We retrospectively reviewed our imaging and clinical database for the evaluation of patients admitted to our clinic with complaints of otorhinorrhea between 2017 and 2019. Two radiologists evaluated the imaging studies independently. Consensus data was used in the analysis. Medical record review and phone call were used for the follow-up.

RESULTS

Of the 85 patients included in the retrospective analysis, 82 (96.5%) had rhinorrhea and 3 (3.5%) had otorrhea. Overall, 29 patients (34.1% of all patients) underwent operation for repair of the CSF leakage site. Beta-transferrin test was available and positive in 33 patients (38.8%). Five (5.9%) patients complained headaches after the procedure and complaints were resolved with increased water intake. Postprocedurally, 3 patients (3.5%) had vertigo and 1 patient (1.2%) complained nausea but spontaneous regression were observed in a few hours. None of the patients experienced a significant complication or adverse reaction during follow-up period. Sixty-seven patients (78.8%) had medical record and telephone follow-up. Mean follow-up duration with call was 14.2 months.

CONCLUSION

IGE-MRC is a minimally invasive and highly sensitive imaging technique. The current results during our follow-up demonstrate the relative safety and feasibility of IGE-MRC by using gadobutrol to evaluate CSF leakage.

High-Resolution MRI for Evaluation of Ventriculostomy Tubes: Assessment of Positioning and Proximal Patency

BACKGROUND AND PURPOSE

Imaging evaluation of ventriculostomy tubes, despite the frequency of malfunction, has remained inadequate due to the absence of a systematic way of assessing the catheter itself. In this retrospective review, we assessed the utility of high-resolution 3D MR imaging techniques, including CISS and volumetric interpolated breath-hold examination sequences, in the evaluation of ventriculostomy catheters.

MATERIALS AND METHODS

We performed a retrospective review of 23 clinical MR imaging cases of shunted hydrocephalus spanning a 3-year period, all depicting ventriculostomy catheters. The MR imaging examinations included isotropic CISS and volumetric interpolated breath-hold examination sequences performed with and without contrast. These were independently evaluated by 2 neuroradiologists with respect to the catheter course, side hole position, relationship of the side holes to the ventricles, patency, and the presence or absence of intraluminal debris.

RESULTS

The catheter tip was best seen on isotropic CISS sequences reformatted in an oblique plane, and side holes were visualized as CSF signal defects along the catheter wall in 10/23 (43%) cases. The relationship of the catheter side holes to the ventricles was seen in 47% of cases and was best visualized on the coronal CISS sequences. Catheter patency was confirmed in 12/23 (52%) cases, while the other 48% were notable for T2 hypointense filling defects compatible with luminal obstruction. Enhancement of some of these filling defects on imaging is suggestive of choroid plexus ingrowth rather than debris.

CONCLUSIONS

High-resolution 3D MR imaging using isotropic CISS sequences allows systematic evaluation of catheter positioning, patency, and potential etiologic differentiation of filling defects when shunt dysfunction is suspected.

[Magnetic resonance cisternography]

CLINICAL/METHODICAL ISSUE

Conventional MRI can be insufficient to depict certain pathologies of the cerebrospinal fluid (CSF)-filled spaces.

STANDARD RADIOLOGICAL METHODS

3-D T2-weighted sequences and phase-contrast imaging have a high sensitivity for pathologies of the CSF-filled spaces, but are susceptible to artifacts in some cases.

METHODICAL INNOVATIONS/PERFORMANCE

Magnetic resonance (MR) cisternography directly depicts the connection between CSF-filled spaces.

Can We Predict Early Endoscopic Third Ventriculostomy Failure? The Role of Ultra-Early Postoperative Magnetic Resonance Imaging in Predicting Early Endoscopic Third Ventriculostomy Failure

Background

The success of endoscopic third ventriculostomy (ETV) depends on multiple preoperative and intraoperative factors. The multifactorial influence adds an element of unpredictability to the outcome of the most well-planned procedure. Clinical symptoms and signs may not reflect the status of the ETV stoma postprocedure and the morbidity associated with ETV failure could be catastrophic. In this study, the authors look at the role of early magnetic resonance imaging (MRI) to predict failure to avoid morbidity secondary to malfunction and propose a modified success criterion to guide treatment plan post-ETV failure. Our aim is to prospectively and retrospectively study the use of early postoperative MRI in predicting potential early ETV failure.

Methods

Patients who underwent ETV at Amrita Institute of Medical Sciences from March 2011 to August 2017. The study was a retrospective and prospective observational blinded study. Inclusion criteria included patients with any form of obstructive hydrocephalus who underwent ETV and had undergone an early postoperative MRI in the first 48 hours—or latest by discharge—with a follow-up of at least 3 months. The patient details and the presence of the flow void in the immediate postoperative MRI were documented. Follow-up was for at least 3 months to identify early failures.

Results

A total of 67 ETVs were performed in 65 patients. At 3 months follow-up, of the 59 ETVs with flow void on MRI, 53 were successful, whereas 6 failed. Of the 8 without flow void, 4 were successful. The overall sensitivity was 93.0, whereas specificity was 40.0. With increasing age, the negative predictive value improved from 25% in age <1 year to 100% in age >5 years, with an accuracy reaching 96% to predict failure of ETV.

Conclusions

An early postoperative MRI is very sensitive to failure of ETV, but not highly specific. The negative predictive value and accuracy of MRI improve significantly with increasing age and in non-hemorrhagic non-infective obstructive etiology.

The Added Value of Magnetic Resonance Imaging Cisternography and Ventriculography as a Diagnostic Aid in Pediatric Hydrocephalus

BACKGROUND

Magnetic resonance imaging (MRI) is the "gold standard" method for the evaluation of hydrocephalus. However, diagnosing an obstruction in the ventricular or subarachnoid spaces may pose a challenge for standard diagnostic sequences. In this study, we describe our experience with MRI cisternography (MRIC) or ventriculography (MRIV) for diagnosing or excluding intra- and extraventricular obstructions. Such a differentiation may have a significant impact on choosing the optimal surgical solution.

METHODS

We retrospectively collected data on patients undergoing MRIC/MRIV for diagnosing or excluding obstructions in patients with ventriculomegaly. All patients had MRI suggesting an obstruction, but without a clear cause.

RESULTS

Five children aged 1-17 years were included (3 females). Four underwent an MRIV, and 1 underwent an MRIC. Three children presented with headaches and had a suspected prior endoscopic third ventriculostomy (ETV) failure, and 2 presented with macrocephalus and increasing head circumferences. MRIV showed a patent ETV stoma in 2 cases, one of which had a T2 SPACE MRI showing no flow void through the stoma, and a closed stoma in 1 case with a flow void above and below the stoma on T2 SPACE MRI. MRIV and MRIC differentiated between two cases with panventriculomegaly, one of which had an obstruction at the level of the Liliequist membrane, and another with no identifiable obstruction.

CONCLUSIONS

MRIC and MRIV have a complementary role to MRI in assessing selected patients with hydrocephalus suspected of being secondary to an obstruction, but with no clear obstruction location.

Evaluation of hydrocephalus patients with 3D-SPACE technique using variant FA mode at 3T

The major advantages of three-dimensional sampling perfection with application optimized contrasts using different flip-angle evolution (3D-SPACE) technique are its high resistance to artifacts that occurs as a result of radiofrequency or static field, the ability of providing images with sub-millimeter voxel size which allows obtaining reformatted images in any plane due to isotropic three-dimensional data with lower specific absorption rate values. That is crucial during examination of cerebrospinal-fluid containing complex structures, and the acquisition time, which is approximately 5 min for scanning of entire cranium. Recent data revealed that T2-weighted (T2W) 3D-SPACE with variant flip-angle mode (VFAM) imaging allows fast and accurate evaluation of the hydrocephalus patients during both pre- and post-operative period for monitoring the treatment. For a better assessment of these patients; radiologists and neurosurgeons should be aware of the details and implications regarding to the 3D-SPACE technique, and they should follow the updates in this field. There could be a misconception about the difference between T2W-VFAM and routine heavily T2W 3D-SPACE images. T2W 3D-SPACE with VFAM imaging is only a subtype of 3D-SPACE technique. In this review, we described the details of T2W 3D-SPACE with VFAM imaging and comprehensively reviewed its recent applications.

Utility of magnetic resonance cisternography with intrathecal gadolinium in detection of cerebrospinal fluid fistula associated with Mondini dysplasia in a patient with recurrent meningitis: Case report and literature review

Background

The intrathecal contrast-enhanced magnetic resonance cisternography (MRC) is a diagnostic method that has been proven effective in selected patients with various disorders of the cerebrospinal system, including the detection of cerebrospinal fluid (CSF) leaks. The Mondini dysplasia is a malformation of the inner ear characterized by an incomplete cochlear development. The cerebrospinal fistula associated with Mondini dysplasia usually occurs in the first 5-10 years.

Case Description

The case of a 34-year-old woman with CSF rhinorrhea and recurrent meningitis associated with CSF fistula into the right inner ear, which was detected by MRC with intrathecal gadolinium, is presented. The computed tomography (CT) cisternography failed to detect the exact location of the leak. The right Mondini dysplasia was identified on CT of the temporal bone. A subtotal right-sided petrosectomy and fistula closure into the bony labyrinth were performed. After the procedure the patient no longer presented meningitis or CSF leak.

Conclusions

The radiological identification of the site of CSF leak through sensitive imaging studies such as MRC with intrathecal gadolinium is crucial for surgical approach.

Intrathecal gadolinium-enhanced MR cisternography in patients with otorhinorrhea: 10-year experience of a tertiary referral center

PURPOSE

Despite a considerable amount of literature that has been published about the use of intrathecal gadolinium-enhanced MR cisternography (IGE-MRC), there is still relatively lack of evidence as to its long-term effects. Our purpose in this study was twofold: firstly, to assess the long-term safety of the IGE-MRC; secondly, to evaluate the diagnostic performance of IGE-MRC for detecting cerebrospinal fluid (CSF) leak in otorhinorrhea patients.

METHODS

We retrospectively reviewed our imaging and clinical database for the patients admitted to our department for the evaluation of their otorhinorrhea between 2008 and 2017. Two radiologists evaluated the imaging studies independently. Consensus data was used in the analysis. Medical record review and phone call were used for the long-term follow-up.

RESULTS

The retrospective review yielded 166 patients. Rhinorrhea was present in 150 (90.4%) patients and otorrhea in 16 (9.6%) patients. Overall, 67 patients (40.5% of all patients) underwent operation for repair of the CSF leak site. Beta-transferrin test was available and positive in 57 (34.3%) patients. Overall sensitivity of IGE-MRC and paranasal high-resolution CT (HRCT) was 89.3 and 72%, respectively. Within the first 24 h after the procedure, none of the patients experienced a significant complication or adverse reaction. Ninety-nine patients (59.6%) had medical record and telephone follow-up. The mean follow-up duration with call was 37.1 months. Three (3%) patients complained about severe headache 3-4 weeks after the procedure.

CONCLUSIONS

IGE-MRC is a minimally invasive and highly sensitive imaging technique. No adverse side effect during our long-term follow-up might strengthen and support the safety of IGE-MRC.

Spontaneous third ventriculostomy 8 years after diagnosis of obstructive hydrocephalus

BACKGROUND

Spontaneous ventriculostomy is spontaneous rupture of membranes separating the ventricular system from the subarachnoid space in patients with chronic obstructive hydrocephalus that ends with resolution of symptoms. We present a case of spontaneous third ventriculostomy occurred in a 19-year-old girl 8 years after the initial diagnosis of hydrocephalus.

CASE DESCRIPTION

An 11-year-old girl applied to the clinic with intermittent headaches. She was neurologically stable with no visual problems. On her brain MRI, obstructive hydrocephalus was observed. Cerebrospinal fluid diversion procedures were recommended, yet the family denied any interventional procedure. She had routine follow-ups with occasional clinical admissions because of ongoing intermittent headaches. On her last clinical visit, 8 years after the first one, she was in well condition with improvement in her headache in the last 4 months. Her new brain MRI showed an active CSF flow between the basal cistern and the third ventricle.

DISCUSSION AND CONCLUSION

In patients with aqueductal stenosis and without any other mass lesion, wait and see protocol might be conveyed in case of mild symptoms of hydrocephalus. However, there is need for large-scaled studies to make a more comprehensive statement for benign obstructive hydrocephalus cases.

Assessment of third ventriculostomy patency with the 3D-SPACE technique: a preliminary multicenter research study

OBJECT

The goal of this study was to determine the value of the 3D sampling perfection with application-optimized contrasts using different flip-angle evolutions (3D-SPACE) technique in the evaluation of endoscopic third ventriculostomy (ETV) patency.

METHODS

Twenty-six patients with ETV were examined using 3-T MRI units. Sagittal-plane 3D-SPACE with variant flip-angle mode, 3D T1-weighted (T1W), and 3D heavily T2-weighted (T2W) images were obtained with isotropic voxel sizes. Also, sagittal-axial plane phase-contrast cine (PC)-MR images were obtained. The following findings were evaluated: diameters of stoma and third ventricle, flow-void sign on 3D-SPACE and PC-MR images, integrity of the third ventricle on heavily T2W images, and quantitative PC-MRI parameters of the stoma. Obtained sequences were evaluated singly, in combination with one another, and all together.

RESULTS

The mean area, flow, and velocity values measured at the level of stoma in patients with patent stoma were significantly higher than those measured in patients with closed stoma (p < 0.05). There was significant correlation among PC-MRI, 3D-SPACE, and 3D heavily T2W techniques regarding assessment of ETV patency (p < 0.001). The 3D-SPACE technique provided the lowest rate of ambiguous results.

CONCLUSIONS

The 3D-SPACE technique seems to be the most efficient one for determination of ETV patency. The authors suggest the use of 3D-SPACE as a stand-alone first-line sequence in addition to routine brain MRI protocols in assessing patients with ETV, thereby decreasing scan time and reserving the use of a combination of additional sequences such as PC-MRI and 3D heavily T2W images in suspicious or complex cases.

Evaluation of hydrocephalus and other cerebrospinal fluid disorders with MRI: An update

MRI is not only beneficial in the diagnosis of cerebrospinal fluid (CSF)-related diseases, but also aids in planning the management and post-surgery follow-up of the patients. With recent advances in MRI systems, there are many newly developed sequences and techniques that rapidly enable evaluation of CSF-related disorders with greater accuracy. For a better assessment of this group of disorders, radiologists should follow the developments closely and should be able to apply them when necessary. In this pictorial review, the role of MRI in the evaluation of hydrocephalus, CSF diversion techniques, and other CSF disorders is illustrated.

Teaching Points

• The 3D-SPACE seems to be most efficient technique for evaluation of hydrocephalus and ventriculostomy.

• In complex cases, PC-MRI, 3D-heavily T2W, and/or CE-MRC images may prevent false results of 3D-SPACE.

• MRI is beneficial in the diagnosis and management of hydrocephalus and other CSF-related diseases.

Intrathecal gadolinium-enhanced MR cisternography: a comprehensive review

CE-MRC has been in use for the past 15 years and was reported to be a useful method in the evaluation of CSF disorders and hydrocephalus. The use of CE-MRC in conjunction with other MR imaging techniques has been shown to be effective in selected cases for the evaluation of several disorders of cerebrospinal system. CE-MRC has certain advantages over other cisternographic studies with fewer side effects if performed properly. Although intrathecal Gd administration is not widely accepted yet, several recent studies have reported the safety of small-dose intrathecal gadolinium injection. In this review, we describe CE-MRC and review recent applications in several clinical conditions.

Evaluation of aqueductal stenosis by 3D sampling perfection with application-optimized contrasts using different flip angle evolutions sequence: preliminary results with 3T MR imaging

BACKGROUND AND PURPOSE

Diagnosis of AS and periaqueductal abnormalities by routine MR imaging sequences is challenging for neuroradiologists. The aim of our study was to evaluate the utility of the 3D-SPACE sequence with VFAM in patients with suspected AS.

MATERIALS AND METHODS

PC-MRI and 3D-SPACE images were obtained in 21 patients who had hydrocephalus on routine MR imaging scans and had clinical suspicion of AS, as well as in 12 control subjects. Aqueductal patency was visually scored (grade 0, normal; grade 1, partial obstruction; grade 2, complete stenosis) by 2 experienced radiologists on PC-MRI (plus routine T1-weighted and T2-weighted images) and 3D-SPACE images. Two separate scores were statistically compared with each other as well as with the consensus scores obtained from general agreement of both radiologists.

RESULTS

There was an excellent correlation between 3D-SPACE and PC-MRI scores (κ = 0.828). The correlation between 3D-SPACE scorings and consensus-based scorings was higher compared with the correlation between PC-MRI and consensus-based scorings (r = 1, P < .001 and r = 0.966, P < .001, respectively).

CONCLUSIONS

3D-SPACE sequence with VFAM alone can be used for adequate and successful evaluation of the aqueductal patency without the need for additional sequences and examinations. Noninvasive evaluation of the whole cranium is possible in a short time with high resolution by using 3D-SPACE.