Imaging of the Spontaneous Low Cerebrospinal Fluid Pressure Headache: A Review.

Spontaneous intracranial hypotension (SIH) is a significant cause of chronic, postural headaches. Spontaneous intracranial hypotension is generally believed to be associated with cerebrospinal fluid (CSF) leaks, and these leaks can be posttraumatic, iatrogenic, or idiopathic in origin. An integral part of the management of patients with this condition consists of localizing and stopping the leaks. Radiologists play a central role in the workup of this condition detecting leaks using computed tomography, magnetic resonance imaging, or nuclear imaging. In this article, we briefly review SIH and the various imaging modalities, which can be used to identify and localize a spontaneous CSF leak.

A case of anterior cerebral artery dissection caused by scuba diving.

A 51-year-old man was admitted with right hemiparesis during scuba diving, without headache. Brain magnetic resonance (MR) imaging depicted high-intensity areas in the left superior frontal and cingulate gyri on diffusion-weighted imaging. Dissection of the anterior cerebral artery (ACA) was detected using axial MR angiography and 3-dimensional MR cisternography. Dissection of the ACA during and after scuba diving has not been reported before. Dissection of the arteries should be included in the differential diagnosis when neurologic symptoms occur both during and after scuba diving, even if the patient does not experience headache. Furthermore, the combination of MR cisternography and MR angiography is useful to detect ACA dissection.

Diagnostic efficacy of contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging in idiopathic cerebrospinal fluid rhinorrhea.

We report a case of a 50-year-old woman in which contrast-enhanced fluid-attenuated inversion recovery (FLAIR) was used for the diagnosis of idiopathic cerebrospinal fluid rhinorrhea. The pre- and postcontrast FLAIR subtraction images showed a contrasted protrusion of the right olfactory cleft canal, highlighting the potential practicality and effectiveness of using pre- and postcontrast FLAIR subtraction images in diagnosing idiopathic cerebrospinal fluid rhinorrhea, in conjunction with conventional high-resolution computed tomography and magnetic resonance cisternography. The successful diagnosis of cerebrospinal fluid rhinorrhea allowed for treatment through endoscopic nasal surgery to close the fistula with a positive clinical outcome.

Imaging Update of Congenital Hearing Loss: A Recent Insight Imaging Including 3D MRI Cisternography Prior to Cochlear Implant.

SNHL in children is an important issue. Cochlear implant is a highly technological device that is surgically inserted in the cochlea to solve this issue. To evaluate types of anomalies of the inner ear in children with sensorineural hearing loss in a tertiary care hospital and confirm that the routine MRI, MR cisternography and HRCT provides the surgeon with the imaging finding and criteria of patients candidates for CI. Patients and method: 600 patients with SNHL underwent HRCT and MRI. CT examinations were normal in 457 patients (76.2%) and 143 patients (23.8%) with inner ear anomalies. MRI examinations were normal in 440 patients (73.3%) and had inner ear anomalies in 160 patients (26.7%). 3D bFFE and 3D DRIVE was summarized. The 3D bFFE sequence was statistically significantly better than the 3D DRIVE for the demonstration of the cochlear vestibule. Superior, inferior vestibular nerves and facial nerves while 3D DRIVE is superior to 3D bFFE in the visualization of the semicircular canals. HRCT and MRI provide accurate anatomical delineation of complex inner ear structures and 3D improves pre-implant evaluation.

Magnetic Resonance Angiography and Cisternography fused images in acute ischemic stroke may save time during endovascular procedure revealing vessel anatomy.

Background and purpose: Endovascular treatment (EVT) is a time-dependent procedure that aims to remove the arterial blood flow obstruction in brain vessels in acute ischemic stroke. In our center, the MRI patient selection protocol in acute ischemic stroke is performed with DWI, FLAIR, MR angiography (MRA) and MR cisternography (MRC) sequences. MRA and MRC are promptly and automatically fused in order to have a clear detection of vessel anatomy, before and during EVT.Our study aim is to evaluate if the fusion process between MRA and MRC could be considered time-safe and could influence EVT duration or outcome. Materials and methods: 45 patients were retrospectively selected for the study and divided into 2 groups according to the presence of MRC sequence fused with MRA (Group 1) or not (Group 2 - controls). Results: MRA and MRC fusion was able to depict vessel anatomy in all subjects of Group 1 (22 patients, 12 females; age 75.59 years ± 10.87). Group 1 presented EVT time reduction (p < 0.05; p = 0.040) (51.59 min ± 30.94) when compared to Group 2 (23 patients, 13 females; age 75.04 years ± 12.12) (71.96 min ± 34.55) of 20.37 min average. No differences between groups were detected evaluating: NIHSS at admission (p = 0.49) and discharge (p = 0.67), pre-stroke mRS (p = 0.89), mRS at 90 days (p = 0.62), ASPECT (p = 0.98) and ASPECT-DWI scores (p = 0.93), time from symptom onset to groin puncture (p = 0.80), thromboaspiration vs combined technique (p = 0.67), EVT success (p = 0.63). Conclusion: Fusion of MRA and MRC is a safe and promising technique in promptly revealing vascular anatomy beyond vessel obstruction, and can play a role in EVT duration reduction.

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

PURPOSE: To compare the diagnostic efficacies of phase-contrast MRI (PC-MRI) and three-dimensional constructive interference in steady-state (3D-CISS) sequence for the detection of spontaneous third ventriculostomy (STV) on the basis of contrast-enhanced MR cisternography (MRC). PATIENTS AND METHODS: Eleven obstructive hydrocephalus patients with clinically-radiologically suspected STV and ten controls were examined by PC-MRI, 3D-CISS and MRC. PC-MRI and 3D-CISS sequence were applied to view the third ventricle and basal cisterns. Following injection of 0.5-1ml intrathecal Gd-DTPA injection, postcontrast MRC images were obtained in three planes. Presence of STV was scored as follows: grade 0, no existence of STV; grade 1, STV present. Results of PC-MRI and 3D-CISS were compared with the MRC findings. RESULTS: In PC-MRI, five patients were assessed as grade 0 and six cases grade 1. As a result of 3D-CISS sequence, eight cases were evaluated as grade 0 and three cases grade 1. Based on MRC, nine cases were assessed as grade 0 and two cases grade 1. False positivity was found in four cases by PC-MRI and in one case by 3D-CISS. The sensitivity, specificity and accuracy of PC-MRI and 3D-CISS sequence regarding demonstration of STV, were 100, 100, 56, 89, 64, and 91% respectively. DISCUSSION: PC-MRI and 3D-CISS are helpful in confirming the STV. PC-MRI and 3D-CISS should be the first preference. If PC-MRI and 3D-CISS give negative results, then MRC is not required. MRC should be performed on patients who demonstrate suspected STV findings on PC-MRI and 3D-CISS sequences. MRC may prevent false positive results.

Intrathecal gadolinium-enhanced MR-cisternography for the detection of a petrous bone defect in a patient with spontaneous intraventricular pneumocephalus.

Spontaneous otogenic pneumocephalus is a rare entity. We describe the case of a 55-year-old patient with intraventricular pneumocephalus associated with a bony defect at the level of the right petrous bone caused by otomastoiditis. She presented herself at the emergency department with a 1-month history of progressive balance problems, tinnitus and fullness in the right ear. Head-CT showed pneumocephalus secondary to chronic otomastoiditis with focal erosion of the petrous bone. Nasal fluid analysis tested positive on the presence of beta-transferrin. MRI before and after intrathecal gadolinium administration showed leakage of gadolinium into the right mastoid air cells. The dural defect was closed by an artificial graft. Post-operatively, gait problems, rhinorrhea and tinnitus resolved, but of mild-to-moderate headache persisted at a 3-month outpatient evaluation. This article shows that CT is the imperative for the diagnosis of pneumocephalus and to detect the underlying cause. When there is doubt about the fistula location, MR-cisternography with gadolinium can be a valuable tool to detect or confirm the fistulous site.

Predicting the therapeutic effect of carbamazepine in trigeminal neuralgia by analysis of neurovascular compression utilizing magnetic resonance cisternography.

The aim of this study was to determine whether the evaluation of neurovascular compression (NVC) using new criteria on magnetic resonance (MR) cisternography improves the prediction of the curative effects of carbamazepine (CBZ) in trigeminal neuralgia (TN). In this study, a new analysis of NVC using MR cisternography was performed retrospectively for 280 patients with clinical signs and symptoms suggesting TN. The new analysis examined whether the site of the NVC was less than 3mm from the edge of the exit point and within the first third of the root entry zone on MR cisternography. Prediction of the curative effects of CBZ using the new evaluation of distance to the NVC improved on the predictive ability of the previous method of calculating the NVC volume (Mantel-Haenszel coefficient, P<0.01). In particular, initial treatment with CBZ 100mg/day for 2 weeks appeared more effective for patients with NVC volumes of ≤5mm3 plus a distance to the NVC of ≤3mm, than for those with NVC volumes >5mm3. The evaluation of NVC on MR cisternography using this new approach appears to be more useful than the previous method for predicting the initial treatment response in patients with TN.

Intrasphenoidal Encephalocele with Spontaneous Cerebrospinal Fluid Rhinorrhea in Idiopathic Intracranial Hypertension: Need for Clarity in Terminology and Imaging Delineation.

BACKGROUND: Magnetic resonance imaging plays an important role in identification of any underlying structural cause in spontaneous cerebrospinal fluid (CSF) leaks-either rhinorrhea or otorrhea. Sphenoid bone defects have been reported in those presenting as idiopathic intracranial hypertension with or without CSF rhinorrhea. Sphenoid lateral recess defect with intrasphenoidal encephalocele is one of the uncommon causes of spontaneous CSF leakage. Many classifications of basal encephaloceles have been used along with associated predisposing anatomic factors for the CSF leak. CASE DESCRIPTION: We report 2 cases of spontaneous CSF rhinorrhea in 2 middle-aged females and had intrasphenoidal encephalocele on imaging using 3-dimensional magnetic resonance cisternography and computed tomography. CONCLUSIONS: We discuss the various classification systems of sphenoidal encephaloceles and review the terminology and comprehensive imaging details to be included in reporting such cases for appropriate treatment planning.

[A case of chordoma presenting as recurrent bacterial meningitis with cerebrospinal fluid leakage].

A 52-year-old man was admitted to our hospital because of two episodes of bacterial meningitis within a 6-month period. CSF examination showed neutrophilic pleocytosis with marked elevation of protein and hypoglycorrhachia, but the inflammatory reaction was mild and blood and CSF cultures were negative. At the time of the second admission, intermittent watery nasal discharge caused by CSF rhinorrhea was evident. CT and MR imaging revealed a tiny clival bone defect, and transnasal endoscopic repair was performed successfully. The pathological diagnosis was chordoma based on immunohistochemical staining for brachyury. Although chordoma presenting as recurrent bacterial meningitis occurs extremely rare, asking patients detailed questions about the CSF rhinorrhea must be essential for disclosing unclear infection sources.

Analysis of Various Factors and Techniques to Improve Outcome of Surgical Management of 243 Cases of CSF Rhinorrhea.

Cerebrospinal fluid (CSF) rhinorrhea occurs when there is a communication between subarachnoid space and sinonasal mucosa due to meningeal, osseous and mucosal defects in the cranial base leading to discharge of CSF from the nose. The risk of developing meningitis after CSF rhinorrhea may vary from 5.6 (Leech and Paterson in Lancet 1:1013-1016, 1973) to 60% (Eljarnel and Foy in Br J Neurosurg 5:275-279, 1991). Hence surgical management of CSF rhinorrhea is highly recommended. Transnasal endoscopic approach first described by Wigand in 1981, has been proven to be the approach of choice in comparison to intracranial and external nasal approach (Jones and Becker in Br Med J 322:122-123, 2001) in most cases. The next defining milestone was the pedicled naso septal vascularized flap described by Hadad et al. (Laryngoscope 116(10):1882-1886, 2006), which could be used to manage large defects. In the present study we assessed 243 cases of CSF rhinorrhea managed by transnasal endoscopic approach. We compared the various factors associated with CSF rhinorrhea and the correlation with the outcome of the surgical treatment. We also analyzed the different sites and techniques of surgical repair and have certain recommendations to improve the surgical outcome. The commonest cause of CSF leak was spontaneous (54.32%) and the commonest site was cribriform plate (43.24%). Patients presented most commonly with watery nasal discharge (82.3%). CT scan with cisternography or MR cisternography is the gold standard to identify the suspected site of leak. Out of 243 patients, 77.77% were operated using free grafts and 22.22% by flap repair. Results are comparable. Hence we would advise simple conservative technique with free grafts to reduce morbidity and shorten the postoperative recovery.

Detectability and anatomical correlation of middle ear cholesteatoma using fused thin slice non-echo planar imaging diffusion-weighted image and magnetic resonance cisternography (FTS-nEPID).

Cholesteatomas show high intensity in diffusion-weighted imaging (DWI). We performed fused thin slice non-echo planar imaging (EPI) DWI and magnetic resonance cisternography (FTS-nEPID) for cholesteatoma patients to increase the detectability of FTS-nEPID for cholesteatoma. The subjects are 77 consecutive patients who underwent FTS-nEPID as a preoperative study (mean age: 53.3±21.8, 47 men and 30 women). Otorhinolaryngologists performed the operations. We anatomically classified the middle ear into four portions. A radiologist evaluated the images for cholesteatoma and assessed the anatomical invasive range in four portions using only FTS-nEPID. We classified large cholesteatomas that invaded more than three portions and small ones that invaded less than two portions based on the results obtained from surgery, and calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). For all cholesteatomas with an existing diagnosis, the sensitivity, specificity, PPV, and NPV were 71%, 70%, 94%, and 27%, respectively. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 49%, 85%, 77%, and 64%, respectively. For large cholesteatomas with an existing diagnosis, the sensitivity was 86%. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 51%, 57%, 88%, and 18%, respectively. For small cholesteatomas with an existing diagnosis, the sensitivity, specificity, PPV, and NPV were 59%, 78%, 92%, and 30%, respectively. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 40%, 85%, 60%, and 71%, respectively. FTS-nEPID may be useful for diagnosing cholesteatomas. Further research is needed for anatomical evaluation because there were many false-negative results.

Usefulness of Intrathecal Gadolinium Enhanced Magnetic Resonance Cisternography in Cerebrospinal Fluid Fistula: Case Report

Accurate localization of cerebrospinal fluid(CSF) fistulae makes the planning of surgery easier, increases the chances of successful dural repair and eliminates negative exploration. The authors report our early experience with intrathecal use of gadolinium DTPA(Gd-DTPA) magnetic resonance(MR) cisternography for evaluation of CSF leakage and localization. By means of lumbar puncture, a single dose of 1ml of gadolinium DTPA mixed with 4ml NaCl 5% was injected. The images were interpreted by comparing those before and after injection. Three patients showed leakage of contrast material through the cribriform plate into the ethmoid or sphenoid air cells. No leakage was observed in one patient. The study results show the relatively safety and feasibility of low-dose Gd-DTPA MR cisternography in confirming the presence and determining the focus of active CSF leaks.