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CSF-venous fistulas (CVFs) are a common cause of spontaneous intracranial hypotension. Despite their relatively frequent occurrence, they can be exceedingly difficult to detect on imaging. Since the initial description of CVFs in 2014, the recognition and diagnosis of this type of CSF leak has continually increased. As a result of multi-institutional efforts, a wide spectrum of imaging modalities and specialized techniques for CVF detection is now available. It is important for radiologists to be familiar with the multitude of available techniques, because each has unique advantages and drawbacks. In this article, we review the spectrum of imaging modalities available for the detection of CVFs, explain the advantages and disadvantages of each, provide typical imaging examples, and discuss provocative maneuvers that may improve the conspicuity of CVFs. Discussed modalities include conventional CT myelography, dynamic myelography, digital subtraction myelography, conebeam CT myelography, decubitus CT myelography by using conventional energy-integrating detector scanners, decubitus photon counting CT myelography, and intrathecal gadolinium MR myelography. Additional topics to be discussed include optimal patient positioning, respiratory techniques, and intrathecal pressure augmentation.
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Post-dural puncture headache (PDPH) is an increasingly recognized cause of chronic headache. Outside of clinical history and myelography that requires an additional dural puncture, there is no reliable diagnostic test to evaluate for persistent dural defects. We describe the injection of iodinated contrast into the dorsal epidural space under CT guidance in five patients as a potential tool to visualize persistent dural defects.ABBREVIATIONS: PDPH = post-dural puncture headache; SIH = spontaneous intracranial hypotension; DSM = digital subtraction myelography; CTM = CT myelography.
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Divertículo , Duramadre , Hipotensión Intracraneal , Meninges , Humanos , Hipotensión Intracraneal/diagnóstico por imagen , Divertículo/diagnóstico por imagen , Divertículo/complicaciones , Duramadre/diagnóstico por imagen , Duramadre/patología , Meninges/diagnóstico por imagen , Meninges/patología , Imagen por Resonancia Magnética , Diagnóstico Diferencial , Pérdida de Líquido Cefalorraquídeo/diagnóstico por imagen , Pérdida de Líquido Cefalorraquídeo/etiologíaRESUMEN
BACKGROUND AND PURPOSE: Cerebrospinal fluid (CSF) leaks of the skull base and spine share a common process of CSF volume loss, and yet only the latter has been associated with spontaneous intracranial hypotension (SIH). Despite published claims that only spinal leaks cause SIH, no prior studies have evaluated brain MR imaging in patients with skull base leaks for findings associated with SIH such as dural enhancement. The purpose of our study was to use a validated brain MR imaging scoring system to evaluate skull base CSF leak patients for findings associated with SIH. MATERIALS AND METHODS: We included patients with confirmed skull base CSF leaks and contrast enhanced pre-operative brain MRI. The pre-operative MR images were reviewed for findings associated with SIH using the Bern score. Patient age, presenting symptoms and their duration, and leak site were also recorded. RESULTS: 31 patients with skull base CSF leaks were included. Mean Bern score was 0.9 (range 0-4, SD 1.1), and only 1 patient (3%) had dural enhancement. Mean age was 53 years (range 18-76). Mean symptom duration was 1.3 years, with 22 patients presenting within one year of symptom onset. 23 patients (74.2%) had intraoperative confirmation of leak from the middle cranial fossa, involving the temporal bone, while 7 (22.6%) had leaks from the anterior skull base. One patient, who had dural enhancement, had an infratentorial CSF leak along the petrous segment of the internal carotid artery. CONCLUSIONS: Our study provides further evidence that skull base and spinal CSF leaks represent distinct pathophysiologies and present with different brain MRI findings.ABBREVIATIONS: SIH = Spontaneous Intracranial Hypotension; IIH = Idiopathic Intracranial Hypertension.
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Dilated perivascular spaces (PVSs) are common and easily recognized on imaging. However, rarer giant tumefactive PVSs (GTPVSs) can have unusual multilocular cystic configurations, and are often confused for other pathologic entities, including neoplasms, cystic infarctions, and neuroepithelial cysts. Because GTPVSs are scarcely encountered and even more infrequently operated upon, many radiologists are unaware of the imaging and pathologic features of these lesions. Here, a case of a resected GTPVS is presented, highlighting both its radiologic and histologic characteristics, and discussing how such lesions can be differentiated from their closest mimickers on imaging.
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BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension is a condition resulting from a leak of CSF from the spinal canal arising independent of a medical procedure. Spontaneous intracranial hypotension can present with normal brain MR imaging findings and nonspecific symptoms, leading to the underdiagnosis in some patients and unnecessary invasive myelography in others who are found not to have the condition. Given the likelihood that spontaneous intracranial hypotension alters intracranial biomechanics, the goal of this study was to evaluate MR elastography as a potential noninvasive test to diagnose the condition. MATERIALS AND METHODS: We performed MR elastography in 15 patients with confirmed spontaneous intracranial hypotension from September 2022 to April 2023. Age, sex, symptom duration, and brain MR imaging Bern score were collected. MR elastography data were used to compute stiffness and damping ratio maps, and voxelwise modeling was performed to detect clusters of significant differences in mechanical properties between patients with spontaneous intracranial hypotension and healthy control participants. To evaluate diagnostic accuracy, we summarized each examination by 2 spatial pattern scores (one each for stiffness and damping ratio) and evaluated group-wise discrimination by receiver operating characteristic curve analysis. RESULTS: Patients with spontaneous intracranial hypotension exhibited significant differences in both stiffness and damping ratio (false discovery rate-corrected, Q < 0.05). Pattern analysis discriminated patients with spontaneous intracranial hypotension from healthy controls with an area under the curve of 0.97 overall, and the area under the curve was 0.97 in those without MR imaging findings of spontaneous intracranial hypotension. CONCLUSIONS: Results from this pilot study demonstrate MR elastography as a potential imaging biomarker and a noninvasive method for diagnosing spontaneous intracranial hypotension, including patients with normal brain MR imaging findings.
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Diagnóstico por Imagen de Elasticidad , Hipotensión Intracraneal , Imagen por Resonancia Magnética , Humanos , Hipotensión Intracraneal/diagnóstico por imagen , Diagnóstico por Imagen de Elasticidad/métodos , Femenino , Masculino , Adulto , Persona de Mediana Edad , Imagen por Resonancia Magnética/métodos , Anciano , Adulto JovenRESUMEN
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.
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Duramadre , Hipotensión Intracraneal , Mielografía , Tomografía Computarizada por Rayos X , Hipotensión Intracraneal/diagnóstico por imagen , Humanos , Mielografía/métodos , Duramadre/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Masculino , Femenino , Persona de Mediana Edad , FotonesRESUMEN
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.
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Angiografía por Tomografía Computarizada , Fotones , Tomografía Computarizada por Rayos X , Humanos , Angiografía por Tomografía Computarizada/métodos , Tomografía Computarizada por Rayos X/métodos , Mielografía/métodos , Trastornos Cerebrovasculares/diagnóstico por imagenRESUMEN
BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension (SIH) is caused by spinal cerebrospinal fluid (CSF) leaks. This study assessed whether the certainty and/or multifocality of CSF leaks is associated with the severity of intracranial sequelae of SIH. MATERIALS AND METHODS: A retrospective review was completed of patients with suspected SIH that underwent digital subtraction myelogram (DSM) preceded by brain MRI. DSMs were evaluated for the presence or absence of a CSF leak, categorized both as positive/negative/indeterminate and single versus multifocal. Brain MRIs were assessed for intracranial sequelae of SIH based on two probabilistic scoring systems (Dobrocky and Mayo methods). For each system, both an absolute "numerical" score (based on tabulation of findings) and "categorized" score (classification of probability) were tabulated. RESULTS: 174 patients were included; 113 (64.9%) were female, average age 52.0 ± 14.3 years. One or more definite leaks were noted in 76 (43.7%) patients; an indeterminate leak was noted in 22 (12.6%) patients. 16 (16.3%) had multiple leaks. There was no significant difference in the severity of intracranial findings between patients with a single versus multiple leaks (p values ranged from .36 to .70 using categorized scores and 0.22-0.99 for numerical scores). Definite leaks were more likely to have both higher categorized intracranial scores (Mayo p = .0008, Dobrocky p = .006) and numerical scores (p = .0002 for Mayo and p = .006 for Dobrocky). CONCLUSIONS: Certainty of a CSF leak on diagnostic imaging is associated with severity of intracranial sequelae of SIH, with definite leaks having significantly more intracranial findings than indeterminate leaks. Multifocal leaks do not cause greater intracranial abnormalities.
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BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension is an increasingly recognized condition. Spontaneous intracranial hypotension is caused by a CSF leak, which is commonly related to a CSF-venous fistula. In patients with spontaneous intracranial hypotension, multiple intracranial abnormalities can be observed on brain MR imaging, including dural enhancement, "brain sag," and pituitary engorgement. This study seeks to create a deep learning model for the accurate diagnosis of CSF-venous fistulas via brain MR imaging. MATERIALS AND METHODS: A review of patients with clinically suspected spontaneous intracranial hypotension who underwent digital subtraction myelogram imaging preceded by brain MR imaging was performed. The patients were categorized as having a definite CSF-venous fistula, no fistula, or indeterminate findings on a digital subtraction myelogram. The data set was split into 5 folds at the patient level and stratified by label. A 5-fold cross-validation was then used to evaluate the reliability of the model. The predictive value of the model to identify patients with a CSF leak was assessed by using the area under the receiver operating characteristic curve for each validation fold. RESULTS: There were 129 patients were included in this study. The median age was 54 years, and 66 (51.2%) had a CSF-venous fistula. In discriminating between positive and negative cases for CSF-venous fistulas, the classifier demonstrated an average area under the receiver operating characteristic curve of 0.8668 with a standard deviation of 0.0254 across the folds. CONCLUSIONS: This study developed a deep learning model that can predict the presence of a spinal CSF-venous fistula based on brain MR imaging in patients with suspected spontaneous intracranial hypotension. However, further model refinement and external validation are necessary before clinical adoption. This research highlights the substantial potential of deep learning in diagnosing CSF-venous fistulas by using brain MR imaging.
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Anomalías Múltiples , Aprendizaje Profundo , Fístula , Hipotensión Intracraneal , Humanos , Persona de Mediana Edad , Encéfalo/diagnóstico por imagen , Pérdida de Líquido Cefalorraquídeo/diagnóstico por imagen , Pérdida de Líquido Cefalorraquídeo/complicaciones , Fístula/complicaciones , Hipotensión Intracraneal/complicaciones , Hipotensión Intracraneal/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Mielografía/métodos , Reproducibilidad de los ResultadosRESUMEN
Historically, MR imaging has been unable to detect a pituitary adenoma in up to one-half of patients with Cushing disease. This issue is problematic because the standard-of-care treatment is surgical resection, and its success is correlated with finding the tumor on imaging. Photon-counting detector CT is a recent advancement that has multiple benefits over conventional energy-integrating detector CT. We present the use of dynamic contrast-enhanced imaging using photon-counting detector CT for the detection of pituitary adenomas in patients with Cushing disease.
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Adenoma , Medios de Contraste , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT) , Neoplasias Hipofisarias , Tomografía Computarizada por Rayos X , Femenino , Humanos , Masculino , Adenoma/diagnóstico por imagen , Fotones , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/diagnóstico por imagen , Neoplasias Hipofisarias/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodosRESUMEN
Epidural steroid injections are commonly performed using fluoroscopic or CT guidance. With both modalities, the injection of contrast material is necessary before steroid administration to ensure adequate epidural flow and exclude non-epidural flow. While fluoroscopic guidance is conventional, CT is utilized at some centers and can be particularly helpful in the setting of challenging or postoperative anatomy. It is important for proceduralists to be adept at evaluating contrast media flow patterns under both modalities. The goal of this review article is to describe and provide examples of epidural and non-epidural flow patterns on both conventional fluoroscopy and CT. Specific non-epidural patterns discussed include intrathecal flow, intradural/subdural flow, vascular uptake, flow into the retrodural space of Okada, inadvertent facet joint flow, and intradiscal flow.
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Cauda Equina Neuroendocrine Tumors (CE-NET), previously referred to as paragangliomas are a rare subset of spinal tumors, with limited data on imaging. Herein, we present a retrospective review of clinical and imaging findings of CE-NETs in ten patients who were evaluated at our institution over the past two decades. All patients had well-defined intradural lesions in the lumbar spine which demonstrated slow growth. A review of imaging findings revealed the presence of an eccentric vascular pedicle along the dorsal aspect of the tumor in 8 of the 10 patients (eccentric vessel sign), a distinctive finding that has not previously been reported with this tumor and may help improve the accuracy of imaging-based diagnosis. In all cases, a gross-total resection was performed, with resolution of symptoms in most of the cases.
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Cauda Equina , Neoplasias del Sistema Nervioso Central , Tumores Neuroendocrinos , Paraganglioma , Neoplasias de la Columna Vertebral , Humanos , Neoplasias de la Columna Vertebral/patología , Tumores Neuroendocrinos/diagnóstico por imagen , Tumores Neuroendocrinos/cirugía , Tumores Neuroendocrinos/patología , Cauda Equina/diagnóstico por imagen , Cauda Equina/cirugía , Paraganglioma/diagnóstico por imagen , Paraganglioma/cirugía , Neoplasias del Sistema Nervioso Central/patología , Imagen por Resonancia MagnéticaRESUMEN
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.
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BACKGROUND AND PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
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Fístula , Hipotensión Intracraneal , Humanos , Hipotensión Intracraneal/etiología , Pérdida de Líquido Cefalorraquídeo/complicaciones , Estudios Retrospectivos , Mielografía/métodos , Tomografía Computarizada por Rayos X/métodos , Fístula/complicacionesRESUMEN
BACKGROUND AND PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
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Fístula , Hipotensión Intracraneal , Humanos , Femenino , Persona de Mediana Edad , Masculino , Hipotensión Intracraneal/diagnóstico por imagen , Pérdida de Líquido Cefalorraquídeo/diagnóstico por imagen , Pérdida de Líquido Cefalorraquídeo/complicaciones , Imagen por Resonancia Magnética/métodos , Mielografía/métodos , Fístula/complicacionesRESUMEN
We present an updated ultrafast dynamic computed tomography myelography technique that can be used for the localization of spontaneous spinal cerebrospinal fluid leaks in the setting of spontaneous intracranial hypotension. This has over twice the temporal resolution of previously described techniques at the same radiation dose output.
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Pituitary development arises from ectodermal tissue creating Rathke's pouch and ultimately the adenohypophysis anteriorly whereas neuroectodermal tissue arising from the diencephalon creates the neurohypophysis posteriorly. Alterations in pituitary development can lead to hormonal dysregulation and dysfunction. Following clinical suspicion of pituitary endocrinopathy, MRI plays a vital role in identifying and characterizing underlying structural abnormalities of the pituitary gland, as well as any associated extrapituitary findings. Here we report a case of an 18-month-old female presenting with short stature and growth hormone deficiency. MRI was notable for a shallow sella turcica, a hypoplastic adenohypophysis, thin pituitary stalk, and ectopic neurohypophysis. Interestingly, the pituitary stalk was noted to split dorsoventrally with a split pituitary bright spot and T1 hypointense lobe hypothesized to represent separation of the posterior pituitary lobes.