CT Myelography Research Articles

A Case Report: Malignant Cerebral Edema as an Anaphylactic Reaction to Intrathecal Contrast from CT Myelography (P9-4.010)

A Case Report: Malignant Cerebral Edema as an Anaphylactic Reaction to Intrathecal Contrast from CT Myelography (P9-4.010)

Optic Nerve Sheath MR Imaging Measurements in Patients with Orthostatic Headaches and Normal Findings on Conventional Imaging Predict the Presence of an Underlying CSF-Venous Fistula.

Spontaneous spinal CSF leaks typically cause orthostatic headache, but their detection may require specialized and invasive spinal imaging. We undertook a study to determine the value of simple optic nerve sheath MR imaging measurements in predicting the likelihood of finding a CSF-venous fistula, a type of leak that cannot be detected with routine spine MR imaging or CT myelography, among patients with orthostatic headache and normal conventional brain and spine imaging findings. This cohort study included a consecutive group of patients with orthostatic headache and normal conventional brain and spine imaging findings who underwent digital subtraction myelography under general anesthesia to look for spinal CSF-venous fistulas. The study group consisted of 93 patients (71 women and 22 men; mean age, 47.5 years; range, 17-84 years). Digital subtraction myelography demonstrated a CSF-venous fistula in 15 patients. The mean age of these 8 women and 7 men was 56 years (range, 23-83 years). The mean optic nerve sheath diameter was 4.0 mm, and the mean perioptic subarachnoid space was 0.5 mm in patients with a CSF-venous fistula compared with 4.9 and 1.2 mm, respectively, in patients without a fistula (P < .001). Optimal cutoff values were found at 4.4 mm for optic nerve sheath diameter and 1.0 mm for the perioptic subarachnoid space. Fistulas were detected in about 50% of patients with optic nerve sheath diameter or perioptic subarachnoid space measurements below these cutoff values compared with <2% of patients with optic nerve sheath diameter or perioptic subarachnoid space measurements above these cutoff values. Following surgical ligation of the fistula, optic nerve sheath diameter increased from 4.0 to 5.3 mm and the perioptic subarachnoid space increased from 0.5 to 1.2 mm (P < .001). Concerns about a spinal CSF leak should not be dismissed in patients with orthostatic headache when conventional imaging findings are normal, and simple optic nerve sheath MR imaging measurements can help decide if more imaging needs to be performed in this patient population.

Benefits of Photon-Counting CT Myelography for Localization of Dural Tears in Spontaneous Intracranial Hypotension.

Photon-counting CT is an increasingly used technology with numerous advantages over conventional energy-integrating detector CT. These include superior spatial resolution, high temporal resolution, and inherent spectral imaging capabilities. Recently, photon-counting CT myelography was described as an effective technique for the detection of CSF-venous fistulas, a common cause of spontaneous intracranial hypotension. It is likely that photon-counting CT myelography will also have advantages for the localization of dural tears, a separate type of spontaneous spinal CSF leak that requires different myelographic techniques for accurate localization. To our knowledge, prior studies on photon-counting CT myelography have been limited to techniques for detecting CSF-venous fistulas. In this technical report, we describe our technique and early experience with photon-counting CT myelography for the localization of dural tears.

High yield clinical applications for photon counting CT in neurovascular imaging.

Photon-counting CT (PCCT) uses a novel X-ray detection mechanism that confers many advantages over that used in traditional energy integrating CT. As PCCT becomes more available, it is important to thoroughly understand its benefits and highest yield areas for improvements in diagnosis of various diseases. Based on our early experience, we have identified several areas of neurovascular imaging in which PCCT shows promise. Here, we describe the benefits in diagnosing arterial and venous diseases in the head, neck, and spine. Specifically, we focus on applications in head and neck CT angiography (CTA), spinal CT angiography, and CT myelography for detection of CSF-venous fistulas. Each of these applications highlights the technological advantages of PCCT in neurovascular imaging. Further understanding of these applications will not only benefit institutions incorporating PCCT into their practices but will also help guide future directions for implementation of PCCT for diagnosing other pathologies in neuroimaging.

Management of Spontaneous Spinal CSF Leaks Using Noninvasive Dynamic MR Neurography: A Case Series

AbstractSpontaneous spinal cerebrospinal fluid (CSF) leak presents with orthostatic headache and may lead to formation of subdural collection. Invasive magnetic resonance imaging or computed tomography myelography is routinely used to detect these leaks. Noninvasive dynamic magnetic resonance neurography can also detect these leaks and confirm its resolution post treatment. It includes three-dimensional NerveView, a high-resolution short-tau inversion recovery sequence for better visualization of spinal nerves and leak sites. This article showcases the diagnostic and therapeutic journey of three patients with spontaneous spinal CSF leak all of whom were diagnosed with dynamic magnetic resonance neurography and treated successfully with autologous targeted epidural blood patch. In one case, epidural blood patch was repeated after 2 months for recurrence of the leak.

Symptomatic Long-segment Extradural Arachnoid Cyst: An Interesting Case Report with Literature Review

Abstract Extradural spinal arachnoid cysts are rare lesions which when become symptomatic lead to progressive neurological signs and symptoms. The spectrum of presentation is myriad and surgical intervention is reserved for symptomatic patients. A 17-year-old boy presented with features of progressive spastic paraparesis for the last 5 months. Initial radiological work-up was suggestive of thoracolumbar extradural cystic lesion. Computed tomography myelography was not able to detect the dural defect. He underwent surgical excision of the cyst under intraoperative neuromonitoring. The lesion was excised in single piece and the intradural communication was noticed along an exiting nerve root. The dural defect at the mid-length of the lesion was identified and closed watertight. Significant improvement in the sensory-motor complaints was noted in the postoperative period. The identification of the dural defect and ensuring its closure along with the complete removal of the cyst is the key to avoid recurrence and is the standard procedure of choice.

CT Myelography: How to Do It.

CT Myelography: How to Do It.

The effect of myelography dye on bone density measurements utilizing Hounsfield units on CT.

Hounsfield unit (HU) measurements of bone density on CT are increasingly used for preoperative planning in spine surgery. Postmyelogram CT is another common preoperative diagnostic study. However, there is no current literature evaluating whether HU measurements on CT are affected by the presence of myelography dye. The purpose of the current study was to determine if the presence of myelography dye affects HU measurements of bone density in CT studies. Twenty-nine preoperative spine surgery patients who underwent both standard and postmyelography CT performed within 6 months of each other were identified. HU measurements were obtained from an elliptical region of interest using the available software on a standard PACS. Measurements were obtained on the axial cut at the midvertebral body on all lumbar vertebrae on three separate occasions and an average value was calculated for comparative analysis. A 6-week gap was used between measurements of the CT scans and the CT myelograms to diminish bias. The mean age of the cohort was 69 years and the average BMI was 32 kg/m2. Five patients were male and 24 were female. Six of the patients had instrumentation placed prior to the initial CT scan. The average HU measurements for CT levels L1-5 were 165, 171, 145, 154, and 225, respectively, whereas HU measurements for CT myelography of levels L1-5 were 168, 177, 148, 170, and 239, respectively. Strong correlations were noted between the HU measured on CT and CT myelography for L1 (r2 = 0.951), L2 (r2 = 0.966), L4 (r2 = 0.820), and L5 (r2 = 0.900), and moderate for L3 (r2 = 0.668). The presence of myelography dye had no clear effect on CT HU measurements of bone density. The results of this study support the use of CT myelograms for bone density assessment in the absence of standard CT images.

Intercepting Intracept: A Case Report of Idiopathic Arachnoiditis

Introduction: Determining the exact diagnoses for low back is challenging due to the myriad of causative factors. Consequently, rare diagnoses like arachnoiditis are often overlooked, causing patients with this condition to be ineffectively treated. Arachnoiditis involves inflammation of the arachnoid membrane enveloping the spinal cord, can is caused by diverse etiological factors, including infections, trauma, spinal cord contamination, tumors, and genetic predispositions. Case: In this case report, the author describe a 43-year-old female with a past medical history of anxiety and depression who presented with chronic back pain. The patient had previously undergone trials of various neuropathic and nociceptive modulating medications as well as transforaminal and caudal epidural corticosteroid injections, yielding minimal relief. On the evaluation, the patient’s lumbar spine MRI revealed findings suggestive arachnoiditis, a diagnosis that had also been missed on a previous MRI a year prior. Given this, the patient was advised to not undergo the Intercept procedure which had been previously recommended by another provider. Discussion: Given its resemblance to other neurologic conditions, the diagnosis of arachnoiditis involves a comprehensive approach with history, physical examination, and imaging modalities such as MRI or CT myelography serving as critical components. In this case, the patient did not have any history of infection or trauma, making the diagnosis more elusive, and requiring the team to pay more heed to the imaging finding. Although her imaging served supportive evidence or arachnoiditis, it is important to recognize its correlation with clinical findings and the severity of symptoms is not always consistent. Management of arachnoiditis requires a multi-faceted approach with steroids, neuropathic modulating medications, muscle relaxants, cognitive behavioral therapy, and physical therapy. Conclusion: This case report underscores the diagnostic challenges and clinical intricacies associated with spinal arachnoiditis. The presented patient's atypical symptoms and protracted diagnostic journey highlight the importance of ongoing vigilance and comprehensive evaluation in chronic pain management. Further research should investigate effective treatment modalities for this chronic and debilitating condition that is overlooked, given its similarity to other diagnoses and rare prevalence.

Lateral Decubitus Dynamic CT Myelography with Real-Time Bolus Tracking (dCTM-BT) for Evaluation of CSF-Venous Fistulas: Diagnostic Yield Stratified by Brain Imaging Findings.

CSF-venous fistulas (CVFs) associated with spontaneous intracranial hypotension (SIH) may have a transient appearance, relative to contrast arrival, which may influence the diagnostic performance of lateral decubitus CT myelography (CTM). We developed a dynamic CTM protocol using real-time bolus-tracking (dCTM-BT) to improve the temporal resolution and standardize the timing of CTM acquisitions post-intrathecal contrast administration. The purpose of our study was to evaluate the feasibility of the dCTM-BT technique and evaluate its diagnostic yield for CVF detection, stratified by brain MRI SIH findings. Patients with suspected SIH without extradural fluid collection on spine MRI who underwent dCTM-BT were retrospectively reviewed. CT bolus monitoring was performed at the upper thoracic level. Following the visualization of dense intrathecal contrast, at least 3 CTM acquisitions of the spine were obtained and reviewed by 2 neuroradiologists. The Bern SIH score was calculated on the brain MRI. The diagnostic yield for CVF detection was evaluated, stratified by Bern score categories and a receiver operating characteristic (ROC) analysis. Out of 48 patients, 23 (48%) had a CVF on dCTM-BT, located at T1-5 (n = 4), T6-12 (n = 18), L1 (n = 1), with 70% on the right. CVF was identified in 22/22 (100%) of patients who had a high Bern score, 1/7 (14%) of those who had an intermediate score, and 0/19 (0%) of those who had a low score. The area under the ROC curve was 0.99 (95% CI, 0.98-1.00). The optimal cutoff was a Bern score of ≥5 (96% sensitivity, 100% specificity). dCTM-BT is feasible and has excellent diagnostic performance for CVF identification/localization. The Bern score is strongly associated with CVF detection and may help inform who will benefit from dCTM-BT.

Application of a Denoising High-Resolution Deep Convolutional Neural Network to Improve Conspicuity of CSF-Venous Fistulas on Photon-Counting CT Myelography.

Photon-counting detector CT myelography is a recently described technique that has several advantages for the detection of CSF-venous fistulas, one of which is improved spatial resolution. To maximally leverage the high spatial resolution of photon-counting detector CT, a sharp kernel and a thin section reconstruction are needed. Sharp kernels and thin slices often result in increased noise, degrading image quality. Here, we describe a novel deep-learning-based algorithm used to denoise photon-counting detector CT myelographic images, allowing the sharpest and thinnest quantitative reconstruction available on the scanner to be used to enhance diagnostic image quality. Currently, the algorithm requires 4-6 hours to create diagnostic, denoised images. This algorithm has the potential to increase the sensitivity of photon-counting detector CT myelography for detecting CSF-venous fistulas, and the technique may be valuable for institutions attempting to optimize photon-counting detector CT myelography imaging protocols.

A technique to localize posteriorly located spinal dural leaks associated with spontaneous intracranial hypotension: Dorsal-decubitus dynamic CT myelography.

Precise localization and understanding of the origin of cerebrospinal fluid (CSF) leak is crucial to allow targeted treatment. We report the technical feasibility and utility of dorsal-decubitus dynamic computed tomography (DDDCT) myelography to localize posteriorly located dural defects in patients with suspicion of posterolateral dural tears. This study reports a series of four consecutive patients with posteriorly located SLEC and suspicion of posterolateral CSF leak who received DDDCT to localize the site of the leak. Patients were collected between October 2022 and October 2023. The technique of DDDCT and its efficacy to detect the site of CSF leak are reported. In all four patients (three females, one male, mean age 39 years), DDDCT myelography was technically successful and precisely demonstrated the site of the CSF leak. In one patient with both anterior and posterior SLEC, DDDCT allowed to exclude the presence of a posteriorly located leak, while a subsequent ventral decubitus dynamic CT myelography localized the leak. Leak sites were all thoracic, except for one that was cervical. Information obtained from the DDDCT myelography was considered useful to target the treatment of the leak. Based on our experience, DDDCT provided sufficient spatial and temporal resolution to pinpoint fast CSF leaks and it may be considered to localize posterolateral dural defects.

Machine Learning Predicts Decompression Levels for Lumbar Spinal Stenosis Using Canal Radiomic Features from Computed Tomography Myelography.

The accurate preoperative identification of decompression levels is crucial for the success of surgery in patients with multi-level lumbar spinal stenosis (LSS). The objective of this study was to develop machine learning (ML) classifiers that can predict decompression levels using computed tomography myelography (CTM) data from LSS patients. A total of 1095 lumbar levels from 219 patients were included in this study. The bony spinal canal in CTM images was manually delineated, and radiomic features were extracted. The extracted data were randomly divided into training and testing datasets (8:2). Six feature selection methods combined with 12 ML algorithms were employed, resulting in a total of 72 ML classifiers. The main evaluation indicator for all classifiers was the area under the curve of the receiver operating characteristic (ROC-AUC), with the precision-recall AUC (PR-AUC) serving as the secondary indicator. The prediction outcome of ML classifiers was decompression level or not. The embedding linear support vector (embeddingLSVC) was the optimal feature selection method. The feature importance analysis revealed the top 5 important features of the 15 radiomic predictors, which included 2 texture features, 2 first-order intensity features, and 1 shape feature. Except for shape features, these features might be eye-discernible but hardly quantified. The top two ML classifiers were embeddingLSVC combined with support vector machine (EmbeddingLSVC_SVM) and embeddingLSVC combined with gradient boosting (EmbeddingLSVC_GradientBoost). These classifiers achieved ROC-AUCs over 0.90 and PR-AUCs over 0.80 in independent testing among the 72 classifiers. Further comparisons indicated that EmbeddingLSVC_SVM appeared to be the optimal classifier, demonstrating superior discrimination ability, slight advantages in the Brier scores on the calibration curve, and Net benefits on the Decision Curve Analysis. ML successfully extracted valuable and interpretable radiomic features from the spinal canal using CTM images, and accurately predicted decompression levels for LSS patients. The EmbeddingLSVC_SVM classifier has the potential to assist surgical decision making in clinical practice, as it showed high discrimination, advantageous calibration, and competitive utility in selecting decompression levels in LSS patients using canal radiomic features from CTM.

Direct pseudomeningocele contrast injection for spinal CSF leak localization.

CT myelography has been traditionally used to evaluate post-operative paraspinal fluid collections to discern CSF leaking into a pseudomeningocele versus a contained seroma. Rather than performing a lumbar puncture and injecting intrathecal contrast for myelography, we present the first report of direct contrast injection into a post-operative paraspinal pseudomeningocele for CSF leak confirmation and localization. This is a simple procedure that has several advantages over a conventional CT myelogram for the evaluation of post-operative paraspinal fluid collections.

Temporal Characteristics of CSF-Venous Fistulas on Dynamic Decubitus CT Myelography: A Retrospective Multi-Institution Cohort Study.

CSF-venous fistula can be diagnosed with dynamic decubitus CT myelography. This study aimed to analyze the temporal characteristics of CSF-venous fistula visualization on multiphase decubitus CT myelography. A retrospective, multisite study was conducted on patients diagnosed with CSF-venous fistula at 2 institutions between June 2017 and February 2023. Both institutions perform decubitus CT myelography with imaging immediately following injection and usually with at least 1 delayed scan. The conspicuity of CSF-venous fistula was assessed on each phase of imaging. Forty-eight patients with CSF-venous fistula were analyzed. CSF-venous fistulas were better visualized on the early pass in 25/48 cases (52.1%), the delayed pass in 6/48 cases (12.5%) and were seen equally on both passes in 15/48 cases (31.3%). Of 25 cases in which the CSF-venous fistula was better visualized on the early pass, 21/25 (84%) fistulas were still at least partially visible on a delayed pass. Of 6 cases in which the CSF-venous fistula was better visualized on a delayed pass, 4/6 (67%) were partially visible on the earlier pass. Six of 48 (12.5%) CSF-venous fistulas were visible only on a single pass. Of these, 4/6 (66.7%) were seen only on the first pass, and 2/6 (33.3%) were seen only on a delayed pass. One fistula was found with one pass only, and one fistula was discovered upon contralateral decubitus imaging without a dedicated second injection. A dynamic decubitus CT myelography imaging protocol that includes an early and delayed phase, likely increases the sensitivity for CSF-venous fistula detection. Further studies are needed to ascertain the optimal timing and technique for CSF-venous fistula visualization on dynamic decubitus CT myelography and its impact on patient outcomes.

Preoperative examination and intraoperative cerebrospinal fluid leakage test for minimally invasive surgery of spinal extradural arachnoid cysts: illustrative case.

Spinal extradural arachnoid cysts (SEACs) are rare and can cause spinal dysfunction. Total cyst removal and duraplasty via multiple laminectomies are commonly performed. However, to avoid postoperative spinal deformity and axial pain, a minimally invasive surgery via selective laminectomy may be optimal. Therefore, preoperative detection of the dural fistula site is required. A 25-year-old male presented with a 2-month history of progressive gait disturbance and back pain. Conventional magnetic resonance imaging (MRI) revealed SEACs at the T9 to L2 level but did not reveal the dural fistula. Further examinations were performed using sagittal time-spatial labeling inversion pulse MRI and cone-beam computed tomography myelography with a spinal intrathecal catheter, which indicated a dural fistula on the left side at the T12 level. On the basis of these results, dural repair was performed via selective laminectomy. Furthermore, an intraoperative cerebrospinal fluid leakage test by intrathecally injecting saline via a spinal catheter confirmed complete closure of the dural fistula, with no other fistulas. These comprehensive pre and intraoperative examinations may be useful for minimally invasive and selective surgeries in patients with SEACs.

Diagnostic Performance of Decubitus Photon-Counting Detector CT Myelography for the Detection of CSF-Venous Fistulas.

CSF-venous fistulas are a common cause of spontaneous intracranial hypotension. Lateral decubitus digital subtraction myelography and CT myelography are the diagnostic imaging standards to identify these fistulas. Photon-counting CT myelography has technological advantages that might improve CSF-venous fistula detection, though no large studies have yet assessed its diagnostic performance. We sought to determine the diagnostic yield of photon-counting detector CT myelography for detection of CSF-venous fistulas in patients with spontaneous intracranial hypotension. We retrospectively searched our database for all decubitus photon-counting detector CT myelograms performed at our institution since the introduction of the technique in our practice. Per our institutional workflow, all patients had prior contrast-enhanced brain MR imaging and spine MR imaging showing no extradural CSF. Two neuroradiologists reviewed preprocedural brain MRIs, assessing previously described findings of intracranial hypotension (Bern score). Additionally, 2 different neuroradiologists assessed each myelogram for a definitive or equivocal CSF-venous fistula. The yield of photon-counting detector CT myelography was calculated and stratified by the Bern score using low-, intermediate-, and high-probability tiers. Fifty-seven consecutive photon-counting detector CT myelograms in 57 patients were included. A single CSF-venous fistula was definitively present in 38/57 patients. After we stratified by the Bern score, a definitive fistula was seen in 56.0%, 73.3%, and 76.5% of patients with low-, intermediate-, and high-probability brain MR imaging, respectively. Decubitus photon-counting detector CT myelography has an excellent diagnostic performance for the detection of CSF-venous fistulas. The yield for patients with intermediate- and high-probability Bern scores is at least as high as previously reported yields of decubitus digital subtraction myelography and CT myelography using energy-integrating detector scanners. The yield for patients with low-probability Bern scores appears to be greater compared with other modalities. Due to the retrospective nature of this study, future prospective work will be needed to compare the sensitivity of photon-counting detector CT myelography with other modalities.

Abstract 284: Renal Contrast Excretion After Myelography: A Valuable Tool in The Diagnosis of Cerebrospinal‐Venous Fistulae

Introduction Cerebrospinal‐venous fistulae (CSF‐VFs) represent a pathologic, low‐flow direct connection between the intrathecal space, usually at the level of a diverticular dilation of a nerve root sleeve, and the thoracolumbar venous system. They can cause CSF hypovolemia resulting in an often‐debilitating intracranial hypotension syndrome. Lateral decubitus CT or DSA myelography (CTM, DSM) are the gold‐standard modalities for diagnosing these entities. Their high spatial and temporal resolution allows visualization of the abnormal connection between the two spaces. Yet, the small size and low flow make CSF‐VFs radiographically subtle, and may not be consistently visualized even after a correctly‐performed CTM/DSM, requiring repeated invasive procedures to definitively establish or exclude their presence. Opacification of the renal excretory system 30‐60 minutes after lateral decubitus myelograms is thought to be a highly sensitive and specific indirect sign of the presence of a CSF‐VF 1,2, as this amount of time is considered insufficient to allow arachnoid reabsorption of contrast. Renal pelvises hyperdensity or its absence after a negative decubitus CTM/DSM can prompt further myelographic investigation or definitively rule out the presence of a CSF‐VF on the side of the examination, respectively. Methods We present three patients with severely symptomatic CSF‐VFs treated at our hospital between 2021 and 2023. All patients were females (range: 50‐60 years old). All three patients underwent bilateral diagnostic lateral decubitus DSM/CTM. Exams were performed at least 72 hours apart in order to allow complete clearance of intrathecal contrast. After each myelographic acquisition, patients remained in the lateral decubitus position until abdominal CT imaging was performed at 30 and 45 minutes to detect the presence of contrast in the renal collecting system. Results Patients 1 and 2, had a CSF‐VF between nerve root dural diverticula and the azygos system that was directly visualized on lateral decubitus CTM (patient 1: right T10‐T11, patient 2: left T8‐T9). Contrast was detectable in the renal pelvises after myelography was performed on the affected side, and not detectable after the contralateral investigation. One fistula was treated via CT‐guided targeted blood patch and fibrin glue injection and the other via endovascular Onyx embolization of the tributary Intercostal veins. Patient 3 had an extremely slow flow CSF‐VF at the right T11‐12 level that was identified only after 5 right‐sided decubitus myelograms with both modalities. The repeated exams were based on the presence of contrast in the renal pelvises after each right‐sided procedure and on the absence of renal opacification after the left‐sided myelograms. Eventually, a CSF‐VF was identified. Successful Onyx embolization of the foraminal veins of the R T11‐12 levels was performed. All three patients had complete resolution of symptoms. Conclusion Contrast presence in the renal excretory system after a lateral decubitus CTM/DSM is a potentially highly sensitive and specific indirect diagnostic sign that can establish or exclude the presence of a CSF‐VF on the examined side. It could be particularly helpful when the fistula is not initially detected, as it can prompt aggressive continuation of the myelographic work‐up. Similarly, it can exclude its presence on one side, sparing the patient invasive and low yield diagnostic procedures.

Likelihood of Discovering a CSF Leak Based on Intracranial MRI Findings in Patients without a Spinal Longitudinal Extradural Collection: A New Probabilistic Scoring System.

The likelihood of discovering a CSF leak can be determined by assessing intracranial abnormalities. However, the Dobrocky scoring system, which is used to determine this likelihood, did not incorporate patients with CSF-venous fistulas. This study sought to create a new probabilistic scoring system applicable to patients without a spinal longitudinal extradural collection. A retrospective review was completed of patients with suspected spontaneous intracranial hypotension who underwent brain MR imaging followed by digital subtraction myelography with same-day CT myelography. Patients with and without leaks found on digital subtraction myelography were included. MRIs were assessed for numerous reported stigmata of spontaneous intracranial hypotension and were compared between cohorts. One hundred seventy-four patients were included; 113 (64.9%) were women (average age, 52.0 [SD, 14.3] years). A CSF leak was found in 98 (56.3%) patients, nearly all of which (93.9%) were CSF-venous fistulas. Diffuse dural enhancement, internal auditory canals dural enhancement, non-Chiari cerebellar descent, pituitary engorgement, brain sag, dural venous sinus engorgement, and decreased suprasellar cistern size were associated with a CSF leak. A probabilistic scoring system was made in which a single point value was assigned to each of those findings: 0-2 considered low probability and ≥3 considered intermediate-to-high probability of a CSF leak. This study offers a new probabilistic scoring system for evaluating the likelihood of discovering a CSF leak on the basis of intracranial MR imaging findings, though the new system is not superior to that of the Dobrocky method for predicting the presence of CSF leaks.

A Novel Patient-Positioning Device for Dynamic CT Myelography.

We describe a novel patient-positioning device for dynamic CT myelography. Dynamic CT myelography requires angling the patient's spine to distribute dense contrast along the dependent thecal sac. The proposed device is constructed of a low-density reinforced polymer frame and can be raised or lowered to various heights with a hand-operated mechanism, allowing precise adjustment of the spinal angle and control of the contrast bolus, increasing the safety, reproducibility, and sensitivity of dynamic CT myelography.