Search

Torus palatinus is an osseus exostosis found in the midline of the hard palate. It is a relatively common condition and is benign in nearly all cases. However, complications such as airway obstruction, sleep apnea, and swallowing difficulties do exist. One of the more serious complications is osteonecrosis. Osteonecrosis of tori has scantly been reported in the literature. Reported risk factors include bisphosphonate use, trauma, and anticoagulation. Here, we present a case of torus palatinus osteonecrosis in the setting of Denosumab use, a monoclonal antibody for the treatment of osteoporosis. This case brings awareness to a rare, but important, potential complication of long-term use of that medication.

Abstract Background This study characterized vessel wall imaging (VWI) features of Moyamoya disease (MMD) in a predominantly adult population at a North American center. Methods Consecutive patients with VWI were included. Twelve arterial segments were analyzed for wall thickening, degree and pattern of contrast enhancement, and remodeling. Results Overall, 286 segments were evaluated in 24 patients (mean age = 36.0 years [range = 1–58]). Of 172 affected segments, 163 (95%) demonstrated negative remodeling. Complete vessel wall obliteration was most frequent in the proximal M1 (17/48, 35%). Affected segments enhanced in 72/172 (42%) (n = 15 for grade II; n = 54 for concentric and n = 18 for eccentric); 20 of 24 (83%) patients had at least one enhancing segment. Both enhancing and non-enhancing segments were present in 19/20 (95%) patients. Vessel wall enhancement was most common in the proximal segments and correlated to the degree of stenosis (p

Spontaneous intracranial hypotension can be caused by spinal dural tears or CSF-venous fistulas. It is rare for patients to have more than one type of leak at any given time. Here, we illustrate 3 examples of dural tears that co-existed with CSF-venous fistulas, with both being seen on dynamic CT myelography. To our knowledge, coexistent CSF-venous fistulas and dural tears have not been previously illustrated on dynamic CT myelography, even though this is one of the most commonly used modalities to work-up patients with CSF leaks. We discuss the clinical importance of the rare co-occurrence of these leaks with regard to diagnosis and treatment, as well as implications for understanding and classifying CSF leaks.

Loeyz-Dietz syndrome (LDS) is a genetic connective tissue disorder characterized by various clinical manifestations, most notably vasculopathies and skeletal abnormalities. The disease is rare, and has multiple overlapping features with other connective tissue disorders. As such, many radiologists remain unfamiliar with the imaging and clinical findings in LDS. Here, we describe the case of a 14-year-old male without previous diagnosis of LDS who presented with aortic root aneurysm and acute type A aortic dissection. Further workup revealed numerous abnormalities, including marked tortuosity of the cervical arterial system, a bifid uvula, hypertelorism, and a superior mesenteric artery aneurysm. Genetic testing ultimately revealed a mutation in Transforming Growth Factor Beta Receptor 1.

Ependymomas are rare glial tumors that comprise 10% of intracranial pediatric malignancies. Primary central nervous system malignancies can rarely metastasize extracranially. When metastases occur, it usually does so in the setting of surgical manipulation of the central nervous system and can spread through the blood, lymph, or artificial means, for example, a ventriculoperitoneal shunt. We describe the presentation and progression of an 18-month-old boy diagnosed with an ependymoma. Initially managed with surgery, radiation, and ventriculoperitoneal shunt placement for symptomatic hydrocephalus, the tumor later recurred with drop metastasis to the thoracic spinal cord. The patient subsequently developed extensive metastases within the abdominal cavity, which were seeded through a ventriculoperitoneal shunt. We present a case of a rare complication of intra-abdominal tumor seeding and carcinomatosis from an intracranial ependymoma through a ventriculoperitoneal shunt. This is a rare presentation of a possible complication, which requires awareness of both surgeons and radiologists.

In the evaluation of embolic strokes of undetermined source, great emphasis is often placed on cardiovascular disease, namely on atrial fibrillation. Other pathophysiologic mechanisms, however, may also be involved. Carotid artery intraplaque hemorrhage (IPH)—the presence of blood components within an atheromatous plaque—has become increasingly recognized as a possible etiologic mechanism in some cryptogenic strokes. IPH is a marker of plaque instability and is associated with ipsilateral neurologic ischemic events, even in nonstenotic carotid plaques. As recognition of carotid IPH as an etiology of embolic strokes has grown, so too has the complexity with which such patients are evaluated and treated, particularly because overlaps exist in the risk factors for atrial fibrillation and IPH. In this article, we review what is currently known about carotid IPH and how this clinical entity should be approached in the context of the evaluation of embolic strokes of undetermined source.

Although carotid artery intraplaque hemorrhage (IPH) is a known risk-factor for cerebral ischemic events in patients of advanced age, its prevalence in younger cohorts is less certain. The purpose of this study was to assess the prevalence of carotid artery IPH across the age spectrum. A retrospective review was completed of all adult patients from our institution who underwent neck MRA with high-resolution carotid plaque imaging between 2017 and 2020. The mean ages of patients with and without IPH were calculated. The prevalence of IPH was compared between patients that were categorized into age groups. Patients with and without a cerebral ischemic event (e.g., stroke, retinal ischemia) were included. Unilateral anterior circulation ischemic events in patients without atrial fibrillation were presumed to be likely related to ipsilateral carotid artery disease. Multiple regression analysis was performed to determine independent associations with IPH. 634 patients were included (1,268 carotid arteries). Increasing age (OR: 1.04; 95% CI: 1.02–1.06; P = 0.001) was independently associated with IPH. 211 patients had unilateral anterior circulation ischemic events. The mean age of patients with carotid IPH was 71.4 years (SD = 9.9), compared to 62.8 years (SD = 15.8) of those without (P ≤ 0.0001). The prevalence of IPH increased with age in all patients (P = 0.0002). Among patients with ipsilateral anterior circulation ischemic events, each age category above 50 years had a significantly higher prevalence of IPH when compared to patients 18–50 years (P ≤ 0.05 for all comparisons). The prevalence of carotid IPH increases with age and is rare in patients under 50 years. The approximate threshold age for IPH development is likely around 50 years.

Background: Neurotoxoplasmosis is a common opportunistic infection in HIV/AIDS patients. Imaging identification of neurotoxoplasmosis assists in timely treatment. Purpose: To delineate the frequency of imaging abnormalities in patients with neurotoxoplasmosis on different MR sequences with a particular focus on SWI, and NCCT. Material and methods: The PACS database was retroactively searched over a 5-year period for patients with neurotoxoplasmosis who underwent MRI with SWI. Included patients had imaging features of neurotoxoplasmosis based on consensus review by two neuroradiologists, a clinical diagnosis of neurotoxoplasmosis at the time of MRI, and diagnostic confirmation based on positive serum or CSF serology or histopathology; 15 patients were included. The number of abnormal foci with restricted diffusion, increased FLAIR signal, intrinsic T1 hyperintensity, abnormal enhancement (CE-T1WI), and intrinsic hyperdensity on CT were recorded. Results: Intralesional susceptibility signal (ISS) foci on SWI were observed in 93.3% of patients with neurotoxoplasmosis (mean size 5.2 ± 3.8 mm). The average number of ISS foci was 3.9 per patient; 3/15 (20.0%) had a single ISS. Amongst other MR sequences, hyperintense FLAIR foci were the most common abnormalities observed (12.4 lesions/patient), followed by enhancing foci (8.2 lesions/patient), foci of restricted diffusion (7.1 lesions/patient), and intrinsic T1 hyperintense foci (3.4 lesions/patient). Abnormalities were least frequently observed on NCCT: abnormalities were identified in 5/15 (33.3%) patients, at a rate of 0.4 lesions/patient. Conclusion: ISS foci are present in the vast majority of neurotoxoplasmosis patients, likely representing hemorrhage. The incidence and frequency of other abnormal foci are highest on FLAIR, and lowest on NCCT. Keywords: Toxoplasmosis, HIV, AIDS

Background and Purpose: Ultra-high-resolution (UHR) photon-counting-detector (PCD) CT improves image resolution but increases noise, necessitating use of smoother reconstruction kernels that reduce resolution below the system's 0.110 mm maximum spatial resolution. To address this, a denoising convolutional neural network (CNN) was developed to reduce noise in images reconstructed with the available sharpest reconstruction kernel while preserving resolution for enhanced temporal bone visualization., Materials and Methods: With IRB approval, CNN was trained on 6 clinical temporal bone patient cases (1,885 images) and tested on 20 independent cases using a dual-source PCD-CT (NAEOTOM Alpha, Siemens). Images were reconstructed using iterative reconstruction at strength 3 (QIR3) with both clinical routine (Hr84) and the sharpest available head kernel (Hr96). The CNN was applied to images reconstructed with Hr96 and QIR1. Three image series (Hr84-QIR3, Hr96-QIR3, and Hr96-CNN) for each case were randomized for review by two neuroradiologists, assessing overall quality and delineation of the modiolus, stapes footplate, and incudomallear joint., Results: CNN reduced noise by 80% compared to Hr96-QIR3 and 50% relative to Hr84-QIR3, while maintaining high resolution. When compared to the conventional method at the same kernel (Hr96-QIR3), Hr96-CNN significantly decreased image noise (from 204.63 HU to 47.35 HU) and improved SSIM (from 0.72 to 0.99). Hr96-CNN images ranked higher than Hr84-QIR3 and Hr96-QIR3 in overall quality (p<0.001). Readers preferred Hr96-CNN for all three structures., Conclusions: The proposed CNN significantly reduced image noise in UHR PCD-CT, enabling the use of sharpest kernel. This combination greatly enhanced diagnostic image quality and anatomical visualization. ABBREVIATIONS: PCD = Photon-counting-detector; UHR = Ultra-high-resolution; IR = Iterative reconstruction; CNN = Convolutional neural network; SSIM: Structural similarity index., Competing Interests: The authors declare no conflicts of interest related to the content of this article., (© 2024 by American Journal of Neuroradiology.)

Carotid plaque vulnerability features beyond the degree of stenosis may play a key role in the pathogenesis and recurrence of ischemic cerebrovascular events. This study sought to compare intraplaque hemorrhage (IPH) as a marker of plaque vulnerability in symptomatic patients with mild (<50%), moderate (50%-69%), and severe (≥70%) carotid artery stenosis. We included patients who experienced ischemic cerebrovascular events with no other identifiable sources and underwent carotid endarterectomy for mild (n=32), moderate (n=47), and severe (n=58) carotid artery stenosis. The degree of stenosis and imaging hallmarks were assessed by computed tomography angiography or magnetic resonance angiography. Plaque specimens were stained with hematoxylin and eosin and Movat pentachrome staining. Carotid plaques of patients with mild stenosis had a higher extent of IPH (%) on tissue analysis compared with patients with moderate (mild, 15.7% [interquartile range, 7.8%-26.7%]; moderate, 3.9% [0.0%-9.2%]; P <0.001) and severe carotid artery stenosis (mild, 15.7% [interquartile range, 7.8%-26.7%]; severe, 2.5% [interquartile range, 0.0%-11.2%]; P <0.001). When considering the degree of carotid artery stenosis as a continuous variable, a lower lumen narrowing was associated with higher extent of IPH ( P <0.001; R, -0.329). Our major finding is the association of IPH with mild carotid artery stenosis based on histological analysis. The current study may suggest that IPH potentially plays a role in the mechanism of stroke in patients with nonobstructive carotid stenosis.