MR imaging at very high field (3.0 T) is a significant new clinical tool in the modern neuroradiological armamentarium. In this report, we summarize our 40-month experience in performing clinical neuroradiological examinations at 3.0 T and review the relevant technical issues. We report on these issues and, where appropriate, their solutions. Issues examined include: increased SNR, larger chemical shifts, additional problems associated with installation of these scanners, challenges in designing and obtaining appropriate clinical imaging coils, greater acoustic noise, increased power deposition, changes in relaxation rates and susceptibility effects, and issues surrounding the safety and compatibility of implanted devices. Some of the these technical factors are advantageous (eg, increased signal-to-noise ratio), some are detrimental (eg, installation, coil design and development, acoustic noise, power deposition, device compatibility, and safety), and a few have both benefits and disadvantages (eg, changes in relaxation, chemical shift, and susceptibility). Fortunately solutions have been developed or are currently under development, by us and by others, for nearly all of these challenges. A short series of 1.5 T and 3.0 T patient images are also presented to illustrate the potential diagnostic benefits of scanning at higher field strengths. In summary, by paying appropriate attention to the discussed technical issues, high-quality neuro-imaging of patients is possible at 3.0 T.

on behalf of the PREDICT/Sunnybrook ICH-CTA study group Background and Purpose-Reliable quantification of both intracerebral hemorrhage and intraventricular hemorrhage (IVH) volume is important for hemostatic trials. We evaluated the reliability of computer-assisted planimetric volume measurements of IVH. Methods-Computer-assisted planimetry was used to quantify IVH volume. Five raters measured IVH volumes, total (intracerebral hemorrhageϩIVH) volumes, and Graeb scores from 20 randomly selected computed tomography scans twice. Estimates of interrater and intrarater reliability were calculated and expressed as an intrarater correlation coefficient and an absolute minimum detectable difference. Results-Planimetric IVH volume analysis had excellent intra-and interrater agreement (intrarater correlation coefficient, 0.96 and 0.92, respectively), which was superior to the Graeb score (intrarater correlation coefficient, 0.88 and 0.83). Minimum detectable differences for intra-and interrater volumes were 12.1 mL and 17.3 mL, and were dependent on the total size of the hematoma; hematomas smaller than the median 43.8 mL had lower minimum detectable differences, whereas those larger than the median had higher minimum detectable differences. Planimetric total hemorrhage volume analysis had the best intra-and interrater agreement (intrarater correlation coefficient, 0.99 and 0.97, respectively). Key Words: intracerebral hemorrhage Ⅲ intraventricular hemorrhage Ⅲ planimetry H ematoma volume and intraventricular hemorrhage (IVH) are independent predictors of outcome following intracerebral hemorrhage (ICH). 1-2 Early ventricular rupture and subsequent autodecompression of parenchymal hematoma is common in ICH. 3 Ventricular decompression of ICH results in IVH expansion, which is also associated with poor outcome. 2 Given that hematoma expansion is a common surrogate outcome for ICH studies, 4 easy and accurate measurement of IVH and volume dynamics following ventricular rupture is relevant to hemostatic trials. In this study, we sought to evaluate the reliability of computer-assisted planimetric measurements for quantifying IVH volumes. Conclusions-Computer-assisted MethodsThe computer-assisted volume measurement software Quantomo (Cybertrial) 5 was used to quantify IVH volumes. Quantomo provides an interface that enables raters to guide segmentation algorithms with manual planimetric intervention to quantify volumes on computed tomography (CT) and magnetic resonance scans. Raters measured ICH and IVH volumes by selecting a hematoma and adjusting intensity thresholds, adding or removing regions to the computerselected region at their discretion, and manually drawing boundaries to separate IVH from ICH. CT scans of patients with both ICH and IVH were blindly and randomly selected from the ongoing PREDICT study. 6 Five raters (2 neurologists, 1 radiologist, 1 neuroradiologist, and 1 radiology trainee) measured IVH volumes, total (ICHϩIVH) volumes, and Graeb scores from 20 randomly selected CT scans twice, presented in a blind...

MR imaging at very high field (3.0 T) is a significant new clinical tool in the modern neuroradiological armamentarium. In this report, we summarize our 40-month experience in performing clinical neuroradiological examinations at 3.0 T and review the relevant technical issues. We report on these issues and, where appropriate, their solutions. Issues examined include: increased SNR, larger chemical shifts, additional problems associated with installation of these scanners, challenges in designing and obtaining appropriate clinical imaging coils, greater acoustic noise, increased power deposition, changes in relaxation rates and susceptibility effects, and issues surrounding the safety and compatibility of implanted devices. Some of the these technical factors are advantageous (eg, increased signal-to-noise ratio), some are detrimental (eg, installation, coil design and development, acoustic noise, power deposition, device compatibility, and safety), and a few have both benefits and disadvantages (eg, changes in relaxation, chemical shift, and susceptibility). Fortunately solutions have been developed or are currently under development, by us and by others, for nearly all of these challenges. A short series of 1.5 T and 3.0 T patient images are also presented to illustrate the potential diagnostic benefits of scanning at higher field strengths. In summary, by paying appropriate attention to the discussed technical issues, high-quality neuro-imaging of patients is possible at 3.0 T.

No abstract

FLIPD MR images obtained with a b value of 1500 sec/mm2 are less suitable for the detection of acute ischemic stroke owing to a decreased sensitivity and negative predictive value. The performance of the two conventional diffusion-weighted MR imaging techniques (b = 1000 and 1500 sec/mm2) was equivalent.

A 29-year-old female was found in her home in a seated position in a floor-level cupboard with a depressed level of consciousness after ingesting an overdose of amitriptyline and alcohol the night before. She was transferred to hospital and treated for tricyclic antidepressant overdose and was found to have rhabdomyolysis. Her creatine kinase peaked at 70 000 units/L.Within 24 hours after admission, the patient recovered her normal level of consciousness and complained of bilateral hip, groin and buttock pain exacerbated by movement. She also had weakness, paresthesias and numbness in both lower extremities, more pronounced on the right. Following initial consideration of other possible causes, Neurology was consulted.Her examination demonstrated normal cranial nerves and upper extremity function. The patient had pain with passive flexion of the hips. There was bilateral weakness of leg extension (2/5), hip abduction (3/5), knee flexion (3/5), ankle dorsiflexion (4-/5), plantar flexion (4-/5), foot inversion (4-/5), foot eversion (4-/5), toe dorsiflexion (4-/5), and toe plantar flexion (4-/5), with each slightly worse for the right leg. Deep tendon reflexes were absent at both ankles but present and symmetric elsewhere, including at the knees and adductor muscles. Plantar responses were flexor. Sensory exam revealed decreased pinprick sensation over the right foot and the lateral lower right leg, along with minimally decreased pin prick sensation over the left sole and medial aspect of the left foot.On day seven of admission, an enhanced Computed Tomography (CT) scan of the pelvis revealed moderately large areas of low attenuation in the gluteus muscles bilaterally, right greater than left (see Figure). The normal fat planes surrounding the sciatic nerve in the sciatic notch (figure, arrows) are obscured by low attenuation fluid or hematoma. The low attenuation is rounded and more prominent on the left than on the right. The low attenuation fluid or hematoma may reflect tracking from the gluteal muscle or direct nerve injury. The findings were consistent with areas of muscle injury, infarct or hematoma due to pressure necrosis and reflected the degree of pressure injury to the gluteal and buttock area. No compartment syndrome was felt to be present by either ICU specialists or surgical consultants. Surgical decompression was considered but not performed. An ultrasound of the lower extremities was negative for deep venous thrombosis. The patient was discharged 11 days after admission, using a wheelchair to mobilize.The patient returned for nerve conduction studies nine weeks after her initial presentation. At that time she was taking gabapentin and oxycodone for neuropathic pain over both distal legs. She required a cane to ambulate and wore a right ankle THE CANADIAN JOURNAL OF NEUROLOGICAL SCIENCES 365 A Patient with Bilateral Sciatic NeuropathiesErin K. O'Ferrall, Kevin Busche, Peter Dickhoff, Rana Zabad, Cory Toth Can. J. Neurol. Sci. 2007; 34: 365-367 PEER REVIEWED LETTER brace for foot drop. Her physic...

Introduction: Clinical context is critical for accurate radiologic interpretation of neuroimaging investigations. The aim of this study was to determine the impact of a change in the Emergency Department (ED) computerized provider order entry (CPOE) interface on the quality of clinical information conveyed in ED neuroimaging requisitions for suspected stroke patients. Methods: Four local EDs utilizing a common CPOE ED Stroke order set were studied before and after the introduction of a mandatory blank free text field requiring clinical information for the radiologist before a computed tomography angiography (CTA) request could be submitted. Prior to this modification, the indication (acute stroke) was pre-filled in the CTA request for convenience with the option of providing additional information at the discretion of the ordering physician. ED physicians were informed of the change as well as the rationale for its implementation. A retrospective pre (90 days) post (30 days) analysis was conducted across four local EDs to evaluate the impact of the CPOE user interface change on the quality of clinical information provided on neuroimaging orders. Patients aged 18 with CTA head and/or neck orders submitted from the order set were included. Patients were excluded if the CTA order was submitted outside of the ED Stroke order set, if order entry was by non-physician personnel, or if the order was modified by the diagnostic imaging department after ED submission. Clinical information from CTA orders were scored as complete, partial, or absent/uninformative based on a standardized rubric of critical elements, including: description of neurological deficit(s), lateralization, and timing of symptom onset or duration. Results were analyzed using chi square analysis. Results: Pre-implementation data from Oct 1, 2015 Jan 1, 2016 (N=652) was compared to post-implementation data from Nov 1 30, 2016 (N=227). The proportion of complete, partial, and absent/uninformative clinical histories were: 45.3%, 31.4%, and 23.3% in the pre-implementation period and 62.6%, 37.4%, and 0% in the post-implementation period respectively. There was a 38.2% relative increase in complete clinical histories, a 19.1% relative increase in partial clinical histories, and a 100% reduction in absent/uninformative clinical histories (p<0.001). Conclusion: The introduction of a mandatory free text field significantly increased the overall quality of clinical information provided on ED neuroimaging orders. This CPOE strategy has the potential to improve diagnostic accuracy and reduce unnecessary delays to imaging interpretation caused by lack of clinical information.