- Variability of T2-Relaxation Times of Healthy Lumbar Intervertebral Discs is More Homogeneous within an Individual Than across Healthy Individuals
Using prospectively acquired T2-relaxometry data from 606 intervertebral discs in 101 volunteers without back pain in a narrow age range (25–35 years), the authors calculated intra- and intersubject variation in T2 times of IVDs graded by 2 neuroradiologists on the Pfirrmann scale. Intrasubject variation of IVDs was assessed relative to other healthy IVDs (Pfirrmann grade, #2) in the same individual. Multiple intersubject variability measures were calculated using healthy extraneous references ranging from a single randomly selected IVD to all healthy extraneous IVDs, without and with segmental stratification. They conclude that the study demonstrates a significantly higher variation in the T2 times of IVDs across subjects, and suggests that normative measures based on the T2 times of healthy lumbar IVDs from the same individual are likely to provide the most discriminating means of identifying degenerated IVDs on the basis of T2 relaxometry.
- Cauda Equina and Filum Terminale Arteriovenous Fistulas: Anatomic and Radiographic Features
Intradural AVF below the conus medullaris may develop either on the filum terminale or the cauda equina (lumbosacral and coccygeal radicular nerves). Only 3 detailed cauda equina AVFs have been reported in the literature. The authors present the angiographic and MR imaging findings of cauda equina and filum terminale AVF cases, supplemented with literature research to characterize the radiologic features of the 2 entities. On angiography, filum terminale AVFs were invariably supplied by the extension of the anterior spinal artery accompanied by a closely paralleling filum terminale vein. Cauda equina AVFs were fed by either a radicular or a spinal artery or both arteries, often with a characteristic wavy radicular-perimedullary draining vein.
- Percutaneous CT-Guided Core Needle Biopsies of Head and Neck Masses: Technique, Histopathologic Yield, and Safety at a Single Academic Institution
This is a retrospective review of head and neck biopsies performed from January 2013 through December 2019. Clinical diagnosis and indication, patient demographics, mass location and size, biopsy needle type, technical approach, dose-length product, sedation details, complications, diagnostic histopathologic yield, and the use of iodinated contrast were recorded for each case. Twenty-seven CT-guided head and neck core needle biopsies were performed in 26 patients. The diagnostic sample rate was 100% (27/27). A concordant histopathologic diagnosis was obtained in 93% (25/27) of cases. There was a single complication of core needle biopsy, a small asymptomatic superficial hematoma.