CSF-venous fistulas associated with traumatic spinal pseudomeningoceles.

CSF-venous fistulas (CVFs) are a common cause of spontaneous intracranial hypotension. These fistulas usually occur without any preceding major trauma, surgery, or other iatrogenic cause. Occasionally, patients have a history of minor trauma, though such cases are usually still considered spontaneous. Little is known about predisposing factors that cause patients to develop spontaneous CVFs. Most patients with CVFs have multiple meningeal diverticula on spine imaging, and fistulas usually arise in association with a diverticulum. In the vast majority of cases, the culprit diverticulum from which the CVF arises is atraumatic in origin, presumably on the spectrum of normal variation in spinal anatomy. Here, we present two cases of CVFs that arose in association with posttraumatic pseudomeningoceles. To our knowledge, this phenomenon has not yet been reported, and it potentially represents a novel etiology for CVFs that furthers understanding of their pathogenesis.

Radiology-pathology correlation: Giant tumefactive perivascular spaces.

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.

Back to the Future: Dynamic Contrast-Enhanced Photon-Counting Detector CT for the Detection of Pituitary Adenoma in Cushing Disease.

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.

Safety and histopathologic yield of percutaneous CT-guided biopsies of the skull base, orbit, and calvarium.

PURPOSE: Although CT-guided biopsies of the calvarium, skull base, and orbit are commonly performed, the best approaches, efficacy, and safety of such procedures remain scantly described in the literature. This retrospective review of percutaneous biopsies illustrates several approaches to challenging biopsy targets and provides a review of procedural planning considerations and histopathologic yield. METHODS: A retrospective review of CT-guided biopsies of the skull base, calvarium, and orbit between 1/1/2010 and 10/30/2020 was conducted. Patient demographics and procedural factors were recorded, including lesion size and location, biopsy approach, and needle gauge. Outcomes were also noted, including CT dose length product, complications, and histopathologic yield. RESULTS: Sixty-one CT-guided biopsies were included in the final analysis: 34 skull base, 23 calvarial, and 4 orbital lesions. The initial diagnostic yield was 32/34 (94%) for skull base lesions, with one false-negative and one non-diagnostic sample. Twenty-one of twenty-three (91%) biopsies in the calvarium were initially diagnostic, with one false-negative and one non-diagnostic sample. In the orbit, 4/4 biopsies were diagnostic. The total complication rate for the cohort was 4/61 (6.6%). Three complications were reported in skull base procedures (2 immediate and 1 delayed). A single complication was reported in a calvarial biopsy, and no complications were reported in orbital biopsies. CONCLUSION: Percutaneous CT-guided core needle biopsies can be performed safely and with a high diagnostic yield for lesions in the skull base, calvarium, and orbit.

Pituitary volume changes in pregnancy and the post-partum period.

PURPOSE: Imaging changes in the pituitary volume during pregnancy remains scantly researched. This study set out to assess the differences in total, anterior, and posterior pituitary volume in pregnant women compared to nulliparous and post-partum women. MATERIALS AND METHODS: A retrospective review was completed of women that had undergone MRI imaging of the brain. Patients were divided into three cohorts: pregnant, nulliparous, and post-partum (defined as being within 12 months of delivery). Anterior and posterior pituitary volumes were manually measured. RESULTS: 171 patients were included, of which 68 were pregnant, 52 were post-partum, and 51 were nulliparous. The average anterior (621.0 ± 171.6 mm3) and total (705.4 ± 172.2 mm3) pituitary volumes were significantly larger in pregnant patients than nulliparous women (522.6 ± 159.8 mm3 and 624.5 ± 163.7 mm3, respectively) (p = .002 and p = .01, respectively). The posterior pituitary volume was significantly smaller in pregnant women (84.4 ± 32.9 mm3) compared to both post-partum (101.2 ± 42.0 mm3) and nulliparous (102.0 ± 46.1 mm3) women (p = .02 for both). CONCLUSIONS: The anterior and total pituitary volumes are significantly larger during pregnancy persisting into the post-partum period. The posterior pituitary volume, conversely, decreases during pregnancy, and returns to its normal size in the post-partum period.

Cauda equina neuroendocrine tumors: A single institutional imaging review of cases over two decades.

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.

Clinical and imaging outcomes of 100 patients with cerebrospinal fluid-venous fistulas treated by transvenous embolization.

BACKGROUND: Cerebrospinal fluid-venous fistulas (CSFVF) are a common cause of spontaneous intracranial hypotension (SIH). Transvenous embolization has emerged as a reliable treatment option. We review the clinical presentation, imaging, and clinical outcomes of 100 consecutive CSFVF patients who underwent embolization over 2 years. METHODS: Baseline clinical characteristics, imaging findings (including Bern SIH score), technical outcomes, and long-term imaging and clinical outcomes were collected. All patients had at least 3 months of clinical follow-up and had baseline MRI. 99/100 patients underwent follow-up imaging at ≥3 months post-treatment. RESULTS: 100 patients were included. Mean imaging and clinical follow-up duration was 8.3±7.7 months and 15.0±6.8 months, respectively. The mean duration of symptoms before embolization was 40.9±52 months. Mean baseline Bern SIH score was 5.9±3.3. The most common baseline symptoms were headache (96 patients), tinnitus (55 patients), and cognitive dysfunction (44 patients). Technical success rate was 100%. Mean post-treatment Bern SIH score was 0.9±1.6 (P<0.0001). Following treatment, 95% of patients reported significant improvement or resolution in symptoms (58 patients reporting resolution and 37 reporting improvement). 5 patients reported no improvement. There were no major procedural or periprocedural complications. 10 patients had minor procedural complications that did not result in any change in management (Onyx emboli, venous perforation). 19 patients had rebound intracranial hypertension requiring acetazolamide therapy. 7 patients had recurrent fistula at the initially treated level. CONCLUSIONS: Transvenous embolization of CSFVF in SIH patients is safe and effective with a 95% treatment response, significant improvement in imaging outcomes, and a very low rate of complications.

Dorsoventral splitting of the infundibulum in a child with pituitary hypoplasia.

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.

Incidental diagnosis of presacral ganglioneuroma in a patient with hematuria.

Ganglioneuromas are benign neuroblastic tumors seen most in pediatric population. The most common locations are mediastinal, retroperitoneal and adrenal regions. Ganglioneuromas rarely occur in presacral space. We present one such case of an incidentally diagnosed presacral ganglioneuroma in an asymptomatic 71-year-old male who initially presented with hematuria.

Spontaneous intracranial hypotension: updates from diagnosis to treatment.

Spontaneous intracranial hypotension (SIH) is caused by spinal cerebrospinal fluid (CSF) leaks, which result in continued loss of CSF volume and multiple debilitating clinical manifestations. The estimated annual incidence of SIH is 5/100,000. Diagnostic methods have evolved in recent years due to improved understanding of pathophysiology and implementation of advanced myelographic techniques. Here, we synthesize recent updates and contextualize them in an algorithm for diagnosis and treatment of SIH, highlighting basic principles and points of practice variability or continued debate. This discussion includes finer points of SIH diagnosis, CSF leak classification systems, less common types and variants of CSF leaks, brain MRI Bern scoring, potential SIH complications, key technical considerations, and positioning strategies for different types of dynamic myelography. The roles of conservative measures, non-targeted or targeted blood patches, surgery, and recently developed endovascular techniques are presented.

Features of Idiopathic Intracranial Hypertension on MRI With MR Elastography: Prospective Comparison With Control Individuals and Assessment of Postintervention Changes.

BACKGROUND. Understanding of dynamic changes of MRI findings in response to intracranial pressure (ICP) changes in idiopathic intracranial hypertension (IIH) is limited. Brain stiffness, as assessed by MR elastography (MRE), may reflect changes in ICP. OBJECTIVE. The purpose of this study was to compare pituitary height, ventricular size, and brain stiffness between patients with IIH and control individuals and to evaluate for changes in these findings in patients with IIH after interventions to reduce ICP. METHODS. This prospective study included 30 patients (28 women, two men; median age, 29.9 years) with IIH and papilledema and 21 control individuals (21 women, 0 men; median age, 29.1 years), recruited from January 2017 to July 2019. All participants underwent 3-T brain MRI with MRE; patients with IIH underwent additional MRI examinations with MRE after acute intervention (lumbar puncture with normal closing pressure; n = 11) and/or chronic intervention (medical management or venous sinus stenting with resolution or substantial reduction in papilledema; n = 12). Pituitary height was measured on sagittal MP-RAGE images. Ventricular volumes were estimated using unified segmentation, and postintervention changes were assessed by tensor-based morphometry. Stiffness pattern score and regional stiffness values were estimated from MRE. RESULTS. In patients with IIH, median pituitary height was smaller than in control individuals (3.1 vs 4.9 mm, p < .001) and was increased after chronic (4.0 mm, p = .05), but not acute (2.3 mm, p = .50), intervention. Ventricular volume was not different between patients with IIH and control individuals (p = .33) and did not change after acute (p = .83) or chronic (p = .97) intervention. In patients with IIH, median stiffness pattern score was greater than in control individuals (0.25 vs 0.15, p < .001) and decreased after chronic (0.23, p = .11) but not acute (0.25, p = .49) intervention. Median occipital lobe stiffness was 3.08 kPa in patients with IIH versus 2.94 kPa in control individuals (p = .07) and did not change after acute (3.24 kPa, p = .73) or chronic (3.10 kPa, p = .83) intervention. CONCLUSION. IIH is associated with a small pituitary and increased brain stiffness pattern score; both findings may respond to chronic interventions to lower ICP. CLINICAL IMPACT. The "partially empty sella" sign and brain stiffness pattern score may serve as dynamic markers of ICP in IIH.

Manifestations of radiation toxicity in the head, neck, and spine: An image-based review.

BACKGROUND AND PURPOSE: Radiation therapy is an important component of treatment in patients with malignancies of the head, neck, and spine. However, radiation to these regions has well-known potential side effects, many of which can be encountered on imaging. In this manuscript, we review selected radiographic manifestations of therapeutic radiation to the head, neck, and spine that may be encountered in the practice of radiology. METHODS: We conducted an extensive literature review of known complications of radiation therapy in the head, neck, and spine. We excluded intracranial and pulmonary radiation effects from our search. We selected complications that had salient, recognizable imaging findings. We searched our imaging database for illustrative examples of these complications. RESULTS: Based on our initial literature search and imaging database review, we selected cases of radiation-induced tumors, radiation tissue necrosis (osteoradionecrosis and soft tissue necrosis), carotid stenosis and blowout secondary to radiation, enlarging thyroglossal duct cysts, radiation myelopathy, and radiation-induced vertebral compression fractures. CONCLUSIONS: We describe the clinical and imaging features of selected sequelae of radiation therapy to the head, neck, and spine, with a focus on those with characteristic imaging findings that can be instrumental in helping to make the diagnosis. Knowledge of these entities and their imaging findings is crucial for accurate diagnosis. Not only do radiologists play a key role in early detection of these entities, but many of these entities can be misinterpreted if one is not familiar with them.

Clinical and imaging outcomes of cerebrospinal fluid-venous fistula embolization.

BACKGROUND: We report outcomes of spontaneous intracranial hypotension (SIH) patients who underwent transvenous embolization of cerebrospinal fluid-venous fistulas (CSFVFs) confirmed on digital subtraction myelography (DSM) performed at our institution. METHODS: This is a retrospective evaluation of a prospectively collected database of SIH patients who underwent transvenous embolization of CSFVFs. Only patients who had fistulas confirmed on DSM performed at our institution were included. All patients had a baseline MRI and an MRI performed at least 90 days post-embolization, as well as clinical evaluation using the six item Headache Impact Test (HIT-6) and the Patient Global Impression of Change (PGIC) scales. Paired t-test was used to report changes in Bern MRI scores and HIT-6 scores at follow-up. RESULTS: 40 patients were included (29 female, 11 male). Mean age was 57.4±10.3 years. Mean Bern score improved from 5.7±3.0 at baseline to 1.3±2.0 at follow-up (p<0.0001). Mean HIT-6 score at baseline was 67.2±11.1 and at follow-up was 41.5±10.1 (p<0.0001). Median PGIC was 1, with 36 patients (90.0%) reporting at least minimal improvement and 32 patients (82.5%) reporting much or very much improvement. Complications included persistent local site pain in 12 patients (30%), suspected rebound intracranial hypertension requiring medical intervention in 7 patients (17.5%), and asymptomatic tiny Onyx emboli to the lungs in 3 patients (7.5%). CONCLUSIONS: Transvenous embolization of CSFVFs using Onyx is safe and effective, resulting in significant improvement in headache and overall clinical outcomes in nearly 90% of patients, and substantial improvements in brain MRI abnormalities.

Superficial siderosis associated with an iatrogenic posterior fossa dural leak identified on CT cisternography.

Superficial siderosis refers to hemosiderin deposition along the pial surface of the brain and spinal cord. It results from chronic and repetitive low-grade bleeding into the subarachnoid space. Dural tears are a common cause of superficial siderosis. Although such tears typically occur in the spine, dural tears can also occur in the posterior fossa. In many cases, posterior fossa dural tears are iatrogenic, and patients may present with neuroimaging evidence of postoperative pseudomeningoceles. We present a case of superficial siderosis caused by a persistent posterior fossa dural leak. The patient presented with superficial siderosis 30 years after a Chiari I malformation repair. A pinhole-sized dural tear was identified preoperatively using computed tomography cisternography. The dural defect was successfully repaired. An additional small tear that was not seen on imaging was also identified at surgery and successfully repaired.

Hypervascular mucoepidermoid caricinoma of the palate.

Salivary mucoepidermoid carcinoma is the most common malignant salivary gland tumor. Low or intermediate grade tumors are slow-growing and can be mistaken for benign lesions on both physical exam and imaging studies. We present a case of hypervascular mucoepidermoid carcinoma of the hard palate that was initially thought to represent a benign vascular lesion. To our knowledge, only two prior cases of hypervascular mucoepidermoid carcinoma have been previously reported. This is the first case showing the MRI features of this tumor and its temporal evolution on CT over several years. Our patient ultimately underwent angiographic tumor embolization so that her lesion could be safely biopsied without significant bleeding risk. We present this as a potential diagnostic pitfall and explain how the treatment for hypervascular mucoepidermoid carcinoma varies compared to conventional tumors.

Paraneoplastic cochleovestibulopathy: clinical presentations, oncological and serological associations.

OBJECTIVE: Cochleovestibulopathy is a distinguishable paraneoplastic phenotype. In this study, we evaluate clinical presentation, serological/cancer associations and outcomes of paraneoplastic cochleovestibulopathy. METHODS: Retrospective chart review of patients with hearing impairment and/or vestibulopathy who underwent serological evaluations for paraneoplastic antibodies between January 2007 and February 2021 was performed. RESULTS: Twenty-six patients were identified (men, n=23; median age, 45 years, range: 28-70). Biomarkers detected included: KLHL11-IgG| |(n=20,| |77% (coexisting LUZP4-IgG, n=8)),| ||ANNA1-IgG| | |(n=3,| |12%),| |amphiphysin-IgG|| |(n=2,| |8%)| |and| |LUZP4-IgG|| |(n=1,| |4%). Most common neoplastic association was |testicular|/|extra-testicular| |seminoma| | (n=13,| |50%).|| Hearing| impairment (bilateral, 62%) was |present| |in| |all| |patients.| |Fifteen patients (58%) had cochleovestibular dysfunction as their initial presentation before rhombencephalitis/encephalomyelitis manifestations (hearing loss, four; acute vertigo, eight; both, three). |Brain| |MRI| |demonstrated| |internal| |auditory| |canal| |enhancement| |in| |four |patients.| Audiometry commonly revealed severe-profound bilateral sensorineural hearing loss. Most patients |had| a refractory course |despite| |immunotherapy| |and/or| |cancer| |treatment|. CONCLUSION: Cochleovestibulopathy commonly presents with rapidly progressive bilateral hearing loss and/or acute vertigo. However, in some patients, these symptoms present along with or following brainstem/cerebellar manifestations. KLHL11-IgG and seminoma are the most common serological and cancer associations, respectively. Recognition of this phenotype may aid in earlier diagnosis of paraneoplastic autoimmunity and associated cancer.

Subdural spinal metastases detected on CT myelography: A case report and brief review.

Spinal metastases are most commonly osseous and may extend to the epidural space. Less commonly, spinal metastases can be subdural, leptomeningeal, or intramedullary. Among these, subdural metastases are the most rare, with few reported cases. While these lesions are now almost exclusively detected on MRI, they can rarely be apparent on other modalities. It is important to recognize subdural metastases on any modality, because they have a significant impact on patient prognosis and treatment. We report a case of renal cell carcinoma in a 68-year-old male initially presenting with subdural metastases detected on CT myelography, with subsequent confirmation by MRI. The case illustrates, to our knowledge, the first example of subdural metastatic disease seen on CT myelography.

Intracranial long-term complications of radiation therapy: an image-based review.

BACKGROUND AND PURPOSE: Radiation therapy is commonly utilized in the majority of solid cancers and many hematologic malignancies and other disorders. While it has an undeniably major role in improving cancer survival, radiation therapy has long been recognized to have various negative effects, ranging from mild to severe. In this manuscript, we review several intracranial manifestations of therapeutic radiation, with particular attention to those that may be encountered by radiologists. METHODS: We conducted an extensive literature review of known complications of intracranial radiation therapy. Based on this review, we selected complications that had salient, recognizable imaging findings. We searched our imaging database for illustrative examples of these complications, focusing only on patients who had a history of intracranial radiation therapy. We then selected cases that best exemplified expected imaging findings in these entities. RESULTS: Based on our initial literature search and imaging database review, we selected cases of radiation-induced meningioma, radiation-induced glioma, cavernous malformation, enlarging perivascular spaces, leukoencephalopathy, stroke-like migraine after radiation therapy, Moyamoya syndrome, radiation necrosis, radiation-induced labyrinthitis, optic neuropathy, and retinopathy. Although retinopathy is not typically apparent on imaging, it has been included given its clinical overlap with optic neuropathy. CONCLUSIONS: We describe the clinical and imaging features of selected sequelae of intracranial radiation therapy, with a focus on those most relevant to practicing radiologists. Knowledge of these complications and their imaging findings is important, because radiologists play a key role in early detection of these entities.