Interference In Steady-state Imaging Research Articles

Tortuous is Torturing: An Unusual Case of Basilar Dolichoectasia Causing Trigeminal Neuralgia, as Demonstrated on 3D Constructive Interference in Steady State Images on MRI.

Tortuous is Torturing: An Unusual Case of Basilar Dolichoectasia Causing Trigeminal Neuralgia, as Demonstrated on 3D Constructive Interference in Steady State Images on MRI.

Newer magnetic resonance imaging techniques in neurocysticercosis.

The definitive diagnosis of neurocysticercosis continues to be challenging. We evaluate the role of newer magnetic resonance imaging techniques including constructive interference in steady state, susceptibility-weighted imaging, arterial spin labelling and magnetic resonance spectroscopy in the diagnosis of neurocysticercosis. To study the utility of newer magnetic resonance imaging sequences in the diagnosis of neurocysticercosis. Eighty-five consecutive patients with neurocysticercosis attending a tertiary care hospital and teaching centre in northern India were included in the study. The diagnosis of neurocysticercosis was made by the Del Brutto criteria. All patients received treatment according to standard guidelines and were followed at 3-month intervals. The following magnetic resonance sequences were performed at baseline: T1 and T2-weighted axial sequences; T2 fluid-attenuated inversion recovery axial sequences; diffusion-weighted imaging; susceptibility-weighted imaging; pre and post-contrast T1-weighted imaging; heavily T2-weighted thin sections (constructive interference in steady state); arterial spin labelling (n = 19); and magnetic resonance spectroscopy (n = 24). The mean (±SD) age was 29.4 ± 12.9 years and 76.5% were men. Seizures were the commonest symptom (89.4%) followed by headache (24.3%), encephalitis (9.4%) and raised intracranial pressure (9.4%). Scolex could be visualised in 43.7%, 55.5% and 61.2% of neurocysticercosis patients using conventional, susceptibility-weighted angiography and constructive interference in steady state imaging sequences, respectively. Susceptibility-weighted angiography and constructive interference in steady state images resulted in significantly higher (P < 0.01) visualisation of scolex compared to conventional sequences. Newer magnetic resonance imaging modalities have a lot of promise for improving the radiological diagnosis of neurocysticercosis.

&lt;p&gt;Vertebrobasilar Dolichoectasia as a Rare Cause of Simultaneous Abducens and Vestibulocochlear Nerve Symptoms: A Case Report and Literature Review&lt;/p&gt;

Vertebrobasilar dolichoectasia (VBD) can lead to cranial nerve symptoms. However, multiple cranial nerve symptoms associated with VBD in one case remain extremely rare. We here present the case of a 33-year-old male with VBD diagnosed by multimodality imaging, who developed simultaneous abducens and vestibulocochlear nerve symptoms and subsequently improved after blood pressure control treatment. To our knowledge, this is the first report of such a vascular disorder resulting in simultaneous symptoms of the abducens and vestibulocochlear nerves. This study highlights that such a vascular anomaly should be considered when cranial nerve symptom is encountered, especially when multiple cranial nerves involved. Meanwhile, radiological evalurrrrrrrrrrrrrrrrrrration of such neurovascular conflict using three-dimensional constructive interference in steady-state imaging is recommended.

Contrast-Enhanced CISS Imaging for Evaluation of Neurovascular Compression in Trigeminal Neuralgia: Improved Correlation with Symptoms and Prediction of Surgical Outcomes.

Thin-section MR imaging through the posterior fossa is frequently used for trigeminal neuralgia. Typical heavily T2-weighted imaging methods yield high anatomic detail and contrast between CSF and neurovascular structures, but poor contrast between vessels and nerves. We hypothesized that the addition of gadolinium-based contrast material to 3D-constructive interference in steady-state imaging would improve the characterization of trigeminal compression. Retrospective review of high-resolution MRIs was performed in patients without prior microvascular decompression. 3D-CISS imaging without contrast and with contrast for 81 patients with trigeminal neuralgia and 15 controls was intermixed and independently reviewed in a blinded fashion. Cisternal segments of both trigeminal nerves were assessed for the grade of neurovascular conflict, cross-sectional area, and degree of flattening. Data were correlated with symptom side and pain relief after microvascular decompression using the Fisher exact test, receiver operating curve analysis, and a paired t test. Contrast-enhanced CISS more than doubled the prevalence of the highest grade of neurovascular conflict (14.8% versus 33.3%, P = .001) and yielded significantly lower cross-sectional area (P = 8.6 × 10-6) and greater degree of flattening (P = .02) for advanced-grade neurovascular conflict on the symptoms side compared with non-contrast-enhanced CISS. Patients with complete pain relief after microvascular decompression had significantly lower cross-sectional area on contrast-enhanced CISS compared with non-contrast-enhanced CISS on preoperative imaging (P = 2.0 × 10-7). Performance based on receiver operating curve analysis was significantly improved for contrast-enhanced CISS compared with non-contrast-enhanced CISS. The addition of contrast material to 3D-CISS imaging improves the performance of identifying unilateral neurovascular compression for symptomatic trigeminal neuralgia and predicting outcomes after microvascular decompression.

High-Resolution MRI Findings following Trigeminal Rhizotomy.

Patients with trigeminal neuralgia often undergo trigeminal rhizotomy via radiofrequency thermocoagulation or glycerol injection for treatment of symptoms. To date, radiologic changes in patients with trigeminal neuralgia post-rhizotomy have not been described, to our knowledge. The aim of this study was to evaluate patients after trigeminal rhizotomy to characterize post-rhizotomy changes on 3D high-resolution MR imaging. A retrospective review of trigeminal neuralgia protocol studies was performed in 26 patients after rhizotomy compared with 54 treatment-naïve subjects with trigeminal neuralgia. Examinations were reviewed independently by 2 neuroradiologists blinded to the side of symptoms and treatment history. The symmetry of Meckel's cave on constructive interference in steady-state and the presence of contrast enhancement within the trigeminal nerves on volumetric interpolated breath-hold examination images were assessed subjectively. The signal intensity of Meckel's cave was measured on coronal noncontrast constructive interference in steady-state imaging on each side. Post-rhizotomy changes included subjective clumping of nerve roots and/or decreased constructive interference in steady-state signal intensity within Meckel's cave, which was identified in 17/26 (65%) patients after rhizotomy and 3/54 (6%) treatment-naïve patients (P < .001). Constructive interference in steady-state signal intensity within Meckel's cave was, on average, 13% lower on the side of the rhizotomy in patients posttreatment compared with a 1% difference in controls (P < .001). Small regions of temporal encephalomalacia were noted in 8/26 (31%) patients after rhizotomy and 0/54 (0%) treatment-naïve patients (P < .001). Post-trigeminal rhizotomy findings frequently include nerve clumping and decreased constructive interference in steady-state signal intensity in Meckel's cave. Small areas of temporal lobe encephalomalacia are encountered less frequently.

未破裂脳動脈瘤手術におけるCISS画像による術前評価の意義

未破裂脳動脈瘤手術におけるCISS画像による術前評価の意義

Constructive Interference in Steady State Imaging in the Central Nervous System

Constructive interference in steady state (CISS) is a fully refocused fast-gradient echo sequence that is mainly used in the assessment of the central nervous system. The most important advantages of steady-state imaging are short acquisition times, high signal-to-noise ratio, and better contrast-to-noise ratio. Owing to its cisternographic effect, CISS is useful in the assessment of the cranial nerves, and can also be used when studying cysts, cystic masses, and neurocysticercosis and in hydrocephalus cases. CISS has been shown to be useful in spinal imaging, epecially in cases of arteriovenous malformation and when it is helpful to better characterise intra- and extramedullary cystic abnormalities.

Constructive Interference in Steady State Imaging in the Central Nervous System

Constructive interference in steady state (CISS) is a fully refocused fast-gradient echo sequence that is mainly used in the assessment of the central nervous system. The most important advantages of steady-state imaging are short acquisition times, high signal-to-noise ratio, and better contrast-to-noise ratio. Owing to its cisternographic effect, CISS is useful in the assessment of the cranial nerves, and can also be used when studying cysts, cystic masses, and neurocysticercosis and in hydrocephalus cases. CISS has been shown to be useful in spinal imaging, especially in cases of arteriovenous malformation and when it is helpful to better characterize intra- and extramedullary cystic abnormalities.

THREE-DIMENSIONAL VISUALIZATION OF NEUROVASCULAR COMPRESSION

Abstract Objective: To assess the usefulness of presurgical simulation of microvascular decompression (MVD) by virtual endoscopy (VE), a new tool to analyze three-dimensionally reconstructed magnetic resonance data sets in patients with trigeminal neuralgia or hemifacial spasm (HFS). Methods: In 17 patients (10 with trigeminal neuralgia and seven with HFS) determined to be candidates for MVD, we performed presurgical simulation of MVD using VE. We used constructive interference in steady-state imaging and magnetic resonance angiography to obtain the original images. VE findings were compared with surgical findings. Results: The three-dimensional relations between visible structures seen on VE were consistent with intraoperative findings in all patients. In total, 20 (91%) of 22 neurovascular compression sites in all 17 patients were correctly delineated on VE, with the exception of two small branches identified as offending vessel in two patients with HFS. Perforators that were not apparent on VE limited our ability to accomplish transpositioning of the offending vessels as simulated. The positions of structures that can affect individual surgical approaches, such as the petrosal vein, cerebellar flocculus, and vertebral artery, were also adequately predicted on VE. All patients had excellent surgical outcomes. Conclusion: Presurgical VE in patients with trigeminal neuralgia or HFS is a novel technique that provides excellent visualization of the three-dimensional relations between neurovascular structures and allows simulation of MVD.

Three-dimensional constructive interference in steady-state magnetic resonance imaging in syringomyelia: advantages over conventional imaging

Neuroradiology has become indispensable in detecting the pathophysiology in syringomyelia. Constructive interference in steady-state (CISS) magnetic resonance (MR) imaging can provide superior contrast at the sub-arachnoid tissue borders. As this region is critical in preoperative evaluation, the authors hypothesized that CISS imaging would provide superior assessment of syrinx pathology and surgical planning. Based on records collected from a database of 130 patients with syringomyelia treated at the authors' institution, 59 patients were prospectively evaluated with complete neuroradiological examinations. In addition to routine acquisitions with FLAIR, T1- and T2-weighted, and contrast-enhanced MR imaging series, the authors obtained sagittal cardiac-gated sequences to visualize cerebrospinal fluid (CSF) pulsations and axial 3D CISS MR sequences to detect focal arachnoid webs. Statistical qualitative and quantitative evaluations of spinal cord/CSF contrast, spinal cord/CSF delineation, motion artifacts, and artifacts induced by pulsatile CSF flow were performed. The 3D CISS MR sequences demonstrated a contrast-to-noise ratio significantly better than any other routine imaging sequence (p < 0.001). Moreover, 3D CISS imaging can detect more subarachnoid webs and cavitations in the syrinx than T2-weighted MR imaging with less flow-void artifact. The limitation of 3D CISS imaging is a susceptibility to motion artifacts that can cause reduced spatial resolution. Lengthy acquisition times for axial segments can be reduced with multiplanar reconstruction of 3D CISS-generated sagittal images. Constructive interference in steady-state imaging is the MR sequence of choice in the preoperative evaluation of syringomyelia, allowing significantly higher detection rates of focal subarachnoid webs, whereas standard T2-weighted MR imaging shows turbulent CSF flow voids. Constructive interference in steady-state MR imaging enables the neurosurgeon to accurately identify cases requiring decompression for obstructed CSF. Motion artifacts can be eliminated with technical variations.

Image-guided microradiosurgery for skull base tumors: advantages of using gadolinium-enhanced constructive interference in steady-state imaging

Gamma Knife surgery (GKS) is image-guided surgery for brain tumors. Precise tumor visualization is needed in dose planning to control tumor progression. The surrounding vital structures must also be clearly defined to allow the preservation of their function. A special magnetic resonance (MR) imaging sequence was chosen for use with GKS to treat skull base and suprasellar tumors. Gadolinium-enhanced 0.5-mm constructive interference in steady-state (CISS) slices were obtained in skull base and suprasellar tumors. Each structure that was adjacent to the tumor could be visualized more clearly by using this imaging technique because the tumor became transparent even though there was no change in the appearance of the surrounding structures after injection of Gd. Use of this technique in acoustic tumors allowed the seventh and eighth cranial nerves to be visualized in the cisternal and intrameatal portions; both of which were distinguishable from the tumor. Suprasellar tumor could be distinguished from the adjacent optic pathway. The use of Gd-enhanced CISS imaging allowed for optimal dose planning with very high conformity in every tumor. Achieving this high conformity allowed the preservation of adjacent structures and their functions. Establishing optimal dose planning in brain tumors is very important to overcome the problem of producing new neurological deficits in patients who may already be suffering disease-related deficits. The use of this special CISS MR imaging sequence may help accomplish this goal.

High-resolution constructive interference in steady-state imaging in tethered cord syndrome: technical note

Background Differentiation between nerve roots and the tethered filum terminale in magnetic resonance images remains challenging. It is, however, crucial to select patients for surgical intervention. Method In 1 patient with progressive and 2 patients with stable clinical signs of tethered cord syndrome (TCS), images reconstructed from a 3D constructive interference in steady-state (CISS) sequence were compared with those obtained from a regular T2-weighted fast spin echo sequence. Results Nerve roots of the cauda equina were suppressed, whereas visualization of the filum terminale was much improved in high-resolution CISS sequences. In addition, the level of adhesion of the filum could be localized in relation to elements of the spinal cord. The imaging results were confirmed during surgery and the patient improved considerably after the intervention. The advantages of CISS were also apparent in 2 other patients who are still being observed. Conclusion Constructive interference in steady-state imaging should be considered in the presurgical routine for patients with TCS.

Temporal bone anomalies in the branchio-oto-renal syndrome: detailed computed tomographic and magnetic resonance imaging findings.

To inventory computed tomographic and magnetic resonance imaging findings in the branchio-oto-renal (BOR) syndrome. A prospective computed tomographic and magnetic resonance imaging study on a family with the BOR syndrome. Department of medical imaging and magnetic resonance imaging at St. Jan Brugge, Brugge, Belgium. Eight affected members of a Belgian family. Younger affected family members were excluded because of their age. Computed tomography showed inner ear malformations in all eight affected patients. Magnetic resonance imaging was performed on five patients and showed inner ear malformations. To define hypoplasia or congenital enlargement of the inner ear structures, measurements obtained from a control group of normal subjects were used for comparison. Almost symmetrical cochlear abnormalities were observed on the three-dimensional Fourier transformation-constructive interference in steady state images of the five patients who underwent magnetic resonance imaging; four had dysplasia of the cochlea, and one had hypoplasia. The vestibule was slightly enlarged in one patient; computed tomography and magnetic resonance imaging showed semicircular canal malformations. Magnetic resonance imaging clearly showed bilateral enlarged endolymphatic sacs and ducts, whereas computed tomography showed only unilateral widening of the vestibular aqueduct and borderline widening of the vestibular aqueduct. Magnetic resonance imaging showed bilateral hypoplasia of the cochlear branch of the eighth nerve in one patient. Hypoplasia and dysplasia of the cochlea were consistent findings, and only magnetic resonance imaging was able to evaluate the intracochlear changes in detail and corrected computed tomography in most patients. Moreover, magnetic resonance imaging also detected bilateral hypoplasia of the cochlear branch of the eighth nerve in one patient. A widened vestibular aqueduct and a widened vestibular sac were frequent but not obligatory features of the BOR syndrome. Other malformations of the middle ear included a reduced middle ear cavity and malformations of the ossicular chain.