Isolated Spinal Cord Neurocysticercosis.

The incidence of neurocysticercosis is increasing in the US. The diagnosis is primarily made based on imaging findings, with clinical presentation and epidemiological exposure also playing a role. The differential diagnosis for neurocysticercosis (NCC) is extensive, and being able to differentiate between these conditions on imaging is crucial to making a proper diagnosis. Herein we present a case of a 37-year-old female who presented with lower extremity weakness and was found to have isolated spinal NCC. In this article, we will discuss the symptoms and imaging findings of neurocysticercosis to help guide diagnosis and management.

The Natural History of Small Vestibular Schwannomas.

Objective The incidence of vestibular schwannomas is increasing, and the average tumor size at diagnosis is decreasing. Therefore, understanding the specific growth pattern of small vestibular schwannomas is becoming increasingly important to guide clinical management. The objectives of this study were to evaluate the growth patterns of very small intracanalicular vestibular schwannomas measuring ≤ 4 mm in linear diameter and to assess the likelihood of these lesions ever requiring treatment.  Methods A retrospective review was performed. A search of all MRI brain and internal auditory canal studies suggestive of a vestibular schwannoma from 1995 to 2019 was performed at our institution. This resulted in 372 cases, which were then evaluated for the presence of a vestibular schwannoma measuring ≤ 4 mm. All patients had to have at least one follow-up MRI to be included. Images were reviewed by a neuroradiologist. Results Eight ≤ 4 mm vestibular schwannomas were found that met all search criteria. The distribution of tumor sizes was as follows: three 2 mm, one 3 mm and four 4 mm. None of the ≤ 4 mm vestibular schwannomas identified demonstrated any significant growth in the linear dimension defined as greater than 2 mm of growth over observation times of 1-13 years (mean 6.3 years). None of the lesions ever required a treatment intervention per available medical records. Conclusion None of the ≤ 4 mm intracanalicular vestibular schwannomas identified in this study grew significantly or required treatment. Overall, the findings in this study suggest that vestibular schwannomas measuring ≤ 4 mm are unlikely to grow and ever require treatment.

Sigmoid Sinus Patency following Vestibular Schwannoma Resection via Retrosigmoid versus Translabyrinthine Approach.

Introduction The treatment options for acoustic neuromas are observation with serial imaging, stereotactic radiation, or surgical resection. The most common surgical approaches are the translabyrinthine (TL), the retrosigmoid (RS), and the middle cranial fossa. During the TL approach the sigmoid sinus is decompressed with bipolar cautery to allow greater medial exposure. It is unknown if this causes any long-term narrowing or thrombus of the sigmoid sinus. Methods We performed a retrospective review of patients who underwent acoustic neuroma resection to determine if patients undergoing a TL approach for acoustic neuroma resection develop radiographic evidence of sigmoid sinus stenosis or thrombosis compared with patients undergoing a RS approach. Results A total of 128 patients were included in this study, 56 patients underwent a TL approach and 72 patients underwent a RS approach. We compared the preoperative and postoperative diameter of the ipsilateral and contralateral sigmoid sinus at proximal, midpoint, and distal locations on magnetic resonance imaging examinations. There was no significant difference between the preoperative and postoperative diameter of the ipsilateral or contralateral sigmoid sinus based on surgical approach. Conclusion Decompression of the sigmoid sinus during the TL approach does not have a significant postoperative effect on the dural venous sinus patency.

Quantitative contrast ratio comparison between T1 (TSE at 1.5T, FLAIR at 3T), magnetization prepared rapid gradient echo and subtraction imaging at 1.5T and 3T.

INTRODUCTION: Creating contrast between normal anatomy and pathology is the main goal of imaging. Here we compare contrast ratios of enhancing brain lesions at 1.5T between T1 TSE, magnetization prepared rapid gradient echo (MPRAGE) and subtraction and at 3T between T1 FLAIR, MPRAGE and subtraction. METHODS: Contrast ratio between enhancing lesions and normal contralateral brain was measured for above mentioned sequences during the same imaging session. A total of 27 exams on 25 patients were evaluated. RESULTS: A total of 90 enhancing brain lesions were utilized. Of these 46 were <5 mm diameter. Taking all lesions into account there was a small but statistically significant improvement in contrast ratio at 1.5T with MPRAGE compared to T1 TSE and at 3T for T1 FLAIR compared to MPRAGE. However, there was no statistically significant difference between these sequences for lesions 5 mm or less in diameter. However, subtraction provided a marked and statistically significant improvement in contrast ratio for both all lesions and including only lesions 5 mm or less in diameter. CONCLUSIONS: Our data indicate that for small lesions at 1.5T there is no significant difference in contrast ratio (CR) between T1 TSE and MPRAGE or at 3T between T1 FLAIR and MPRAGE despite the MPRAGE having the advantage of much thinner slices and a higher matrix. However, subtraction provided a markedly improved CR for all lesions at 1.5T and 3T regardless of lesion size. Subtraction should be considered for clinical use to improve detection of small or subtle enhancing lesions.