Kenneth L. Weiss

Rapid MRI Detection of Vertebral Numeric Variation

OBJECTIVE Vertebral column variation is a common, often overlooked finding on traditional spine MRI. Standard localizers do not image the entire neuroaxis, masking variation. The purpose of this study was to use a subminute automated spine survey iterative scan technique (ASSIST) to evaluate 207 patients undergoing thoracic spine MRI. CONCLUSION We found variation in 7.7%, with 69% of these cases going unreported. To enhance patient care and decrease medicolegal implications, we recommend ASSIST be performed on all thoracic and lumbar examinations, with variations documented.

Serotonin Mediated Cluster Headache, Trigeminal Neuralgia, Glossopharyngeal Neuralgia, and Superior Laryngeal Neuralgia with SAD Chronicity

Cluster headache is a rare and severe pain syndrome with elusive pathophysiology. Serotonin pathways within the brainstem may be implicated in cluster headache with seasonal affective disorder and a subset of cranial nerve neuralgias. We describe and chronicle a syndrome consisting of cluster headache, seasonal affective disorder, with associated trigeminal, glossopharyngeal, superior laryngeal neuralgias in an 11-year-old female. Pharmacologic interventions for this patient were examined in conjunction with current classification, location and function of serotonin receptors. Etiology is postulated as mixed cranial nerve excitation via endogenous 5-HT (agonist) activity of 5-HT3 receptors within the nucleus tractus solitarius and trigeminal tract nucleus.

Cranial Nerve Clock

Abstract Rationale and Objectives The authors performed this study to compare a declarative memory paradigm developed to help teach medical students about the cranial nerves with a traditional text-based approach. Materials and Methods The authors designed a clock-based paradigm to help medical students learn about the cranial nerves. To enhance memorization and related brain activation, the paradigm uses visual, spatial, and word associations in the context of an analog clock face. Twenty-one undergraduate students were randomly divided into two groups. Group T viewed traditional text slides, and group C viewed text slides followed by the corresponding cranial clock slides. Subjects were tested before and after these sessions. Results Group C performed significantly better than group T in learning the names of the cranial nerves and their correct order ( P P = .005), V ( P = .04), and X ( P = .03). Conclusion Alternative teaching strategies may help improve declarative memory.

Subminute Fat-Water-Separated Dual-Echo Automated Spine Survey Iterative Scan Technique

SUMMARY: We developed and tested an automated sub-minute 3D dual-echo MR imaging technique producing fat-water color-encoded labeled images of the entire spine. Twenty-one subjects were scanned with the 2-point Dixon technique utilizing 2 contiguous 21-22 second breath-hold sagittal acquisitions. Fourteen alternating subject scan sessions were achieved in 58 minutes. In all cases, fat-water separation was homogenous over the 70 cm FOV; in 2 lower stations fat/water assignments were reversed. Rapid automated fat-water decomposition spine screening is a promising technique.

Pediatric MR imaging with automated spine survey iterative scan technique (ASSIST).

SUMMARY: MR imaging automated spine survey iterative scan technique (ASSIST) provides an automated subminute, submillimeter, in-plane resolution survey of the entire spine in 2 contiguous sagittal fast gradient-echo breath-hold series with computer labeling of vertebrae and disks. The technique was prospectively tested in 13 school-aged children for a wide range of clinical indications. In all cases, imaging was successful without requiring repeated sequencing. In all but 1 patient manifesting prominent scoliosis, automated labeling was concordant with neuroradiologist assignments.

Iterative Decomposition of Water and Fat with Echo Asymmetric and Least—Squares Estimation (IDEAL) (Reeder et al. 2005) Automated Spine Survey Iterative Scan Technique (ASSIST) (Weiss et al. 2006)

Background and Purpose: Multi-parametric MRI of the entire spine is technologist-dependent, time consuming, and often limited by inhomogeneous fat suppression. We tested a technique to provide rapid automated total spine MRI screening with improved tissue contrast through optimized fat-water separation. Methods: The entire spine was auto-imaged in two contiguous 35 cm fi eld of view (FOV) sagittal stations, utilizing out-ofphase fast gradient echo (FGRE) and T1 and/or T2 weighted fast spin echo (FSE) IDEAL (Iterative Decomposition of Water and Fat with Echo Asymmetric and Least-squares Estimation) sequences. 18 subjects were studied, one twice at 3.0T (pre and post contrast) and one at both 1.5 T and 3.0T for a total of 20 spine examinations (8 at 1.5 T and 12 at 3.0T). Images were independently evaluated by two neuroradiologists and run through Automated Spine Survey Iterative Scan Technique (ASSIST) analysis software for automated vertebral numbering. Results: In all 20 total spine studies, neuroradiologist and computer ASSIST labeling were concordant. In all cases, IDEAL provided uniform fat and water separation throughout the entire 70 cm FOV imaged. Two subjects demonstrated breast metastases and one had a large presumptive schwannoma. 14 subjects demonstrated degenerative disc disease with associated Modic Type I or II changes at one or more levels. FGRE ASSIST afforded subminute submillimeter in-plane resolution of the entire spine with high contrast between discs and vertebrae at both 1.5 and 3.0T. Marrow signal abnormalities could be particularly well characterized with IDEAL derived images and parametric maps. Conclusion: IDEAL ASSIST is a promising MRI technique affording a rapid automated high resolution, high contrast survey of the entire spine with optimized tissue characterization.

Cranial nerve clock: Part II: Functional MR imaging of brain activation during a declarative memory task

RATIONALE AND OBJECTIVES The authors performed this study to assess brain activation during encoding and successful recall with a declarative memory paradigm that has previously been demonstrated to be effective for teaching students about the cranial nerves. MATERIALS AND METHODS Twenty-four students underwent functional magnetic resonance (MR) imaging during encoding and recall of the name, number, and function of the 12 cranial nerves. The students viewed mnemonic graphic and text slides related to individual nerves, as well as their respective control slides. For the recall paradigm, students were prompted with the numbers 1-12 (test condition) intermixed with the number 14 (control condition). Subjects were tested about their knowledge of cranial nerves outside the MR unit before and after functional MR imaging. RESULTS Students learned about the cranial nerves while undergoing functional MR imaging (mean post- vs preparadigm score, 8.1 +/- 3.4 [of a possible 12] vs 0.75 +/- 0.94, bilateral prefrontal cortex, left greater than right; P < 2.0 x 10(-12)) and maintained this knowledge at I week. The encoding and recall paradigms elicited distributed networks of brain activation. Encoding revealed statistically significant activation in the bilateral prefrontal cortex, left greater than right [corrected]; bilateral occipital and parietal associative cortices, parahippocampus region, fusiform gyri, and cerebellum. Successful recall activated the left much more than the right prefrontal, parietal associative, and anterior cingulate cortices; bilateral precuneus and cerebellum; and right more than the left posterior cingulate. CONCLUSION A predictable pattern of brain activation at functional MR imaging accompanies the encoding and successful recall of the cranial nerves with this declarative memory paradigm.