Highly efficient head-only magnetic field insert gradient coil for achieving simultaneous high gradient amplitude and slew rate at 3.0T (MAGNUS) for brain microstructure imaging.

PURPOSE: To develop a highly efficient magnetic field gradient coil for head imaging that achieves 200 mT/m and 500 T/m/s on each axis using a standard 1 MVA gradient driver in clinical whole-body 3.0T MR magnet. METHODS: A 42-cm inner diameter head-gradient used the available 89- to 91-cm warm bore space in a whole-body 3.0T magnet by increasing the radial separation between the primary and the shield coil windings to 18.6 cm. This required the removal of the standard whole-body gradient and radiofrequency coils. To achieve a coil efficiency ~4× that of whole-body gradients, a double-layer primary coil design with asymmetric x-y axes, and symmetric z-axis was used. The use of all-hollow conductor with direct fluid cooling of the gradient coil enabled ≥50 kW of total heat dissipation. RESULTS: This design achieved a coil efficiency of 0.32 mT/m/A, allowing 200 mT/m and 500 T/m/s for a 620 A/1500 V driver. The gradient coil yielded substantially reduced echo spacing, and minimum repetition time and echo time. In high b = 10,000 s/mm2 diffusion, echo time (TE) < 50 ms was achieved (>50% reduction compared with whole-body gradients). The gradient coil passed the American College of Radiology tests for gradient linearity and distortion, and met acoustic requirements for nonsignificant risk operation. CONCLUSIONS: Ultra-high gradient coil performance was achieved for head imaging without substantial increases in gradient driver power in a whole-body 3.0T magnet after removing the standard gradient coil. As such, any clinical whole-body 3.0T MR system could be upgraded with 3-4× improvement in gradient performance for brain imaging.

Unique Features of the US Department of Defense Multidisciplinary Concussion Clinics.

The US Department of Defense (DoD) and the Department of Veterans Affairs (VA) actively address care needs for a subset of service members (SMs) who experience prolonged symptoms and adverse sequelae interfering with their usual level of function after sustaining mild traumatic brain injury. The development of multidisciplinary concussion clinics and implementation of several reinforcing policies within the DoD and the VA address this unique patient population. A network known as the National Intrepid Center of Excellence and Intrepid Spirit Centers and the VA, primarily support these patients through intensive outpatient programs. The VA also has an inpatient program that utilizes specialized capabilities. The features unique to several of these centers are described in this article. While providing for similar patient care needs, each clinical setting implements unique evaluation and treatment modalities to target analogous goals of return to the highest functional level possible and develop life skills to enhance health, quality of life, and readiness to perform military duties. Currently, patient-reported outcomes are being collected.

A Randomized Exploratory Study to Evaluate Two Acupuncture Methods for the Treatment of Headaches Associated with Traumatic Brain Injury.

Background: Headaches are prevalent among Service members with traumatic brain injury (TBI); 80% report chronic or recurrent headache. Evidence for nonpharmacologic treatments, such as acupuncture, are needed. Objective: The aim of this research was to determine if two types of acupuncture (auricular acupuncture [AA] and traditional Chinese acupuncture [TCA]) were feasible and more effective than usual care (UC) alone for TBI-related headache. Materials and Methods:Design: This was a three-armed, parallel, randomized exploratory study. Setting: The research took place at three military treatment facilities in the Washington, DC, metropolitan area. Patients: The subjects were previously deployed Service members (18-69 years old) with mild-to-moderate TBI and headaches. Intervention: The interventions explored were UC alone or with the addition of AA or TCA. Outcome Measures: The primary outcome was the Headache Impact Test (HIT). Secondary outcomes were the Numerical Rating Scale (NRS), Pittsburgh Sleep Quality Index, Post-Traumatic Stress Checklist, Symptom Checklist-90-R, Medical Outcome Study Quality of Life (QoL), Beck Depression Inventory, State-Trait Anxiety Inventory, the Automated Neuropsychological Assessment Metrics, and expectancy of outcome and acupuncture efficacy. Results: Mean HIT scores decreased in the AA and TCA groups but increased slightly in the UC-only group from baseline to week 6 [AA, -10.2% (-6.4 points); TCA, -4.6% (-2.9 points); UC, +0.8% (+0.6 points)]. Both acupuncture groups had sizable decreases in NRS (Pain Best), compared to UC (TCA versus UC: P = 0.0008, d = 1.70; AA versus UC: P = 0.0127, d = 1.6). No statistically significant results were found for any other secondary outcome measures. Conclusions: Both AA and TCA improved headache-related QoL more than UC did in Service members with TBI.

Prophylaxis for venous thromboembolism during rehabilitation for traumatic brain injury: a multicenter observational study.

BACKGROUND: Deep venous thrombosis (DVT) is a major cause of mortality and morbidity after traumatic brain injury (TBI). There is no consensus regarding appropriate screening, prophylaxis, or treatment during acute rehabilitation. METHODS: This prospective observational study evaluated prophylactic anticoagulation during rehabilitation in patients with TBI aged 16 years or older admitted to 12 TBI Model Systems rehabilitation centers (July 2004-December 2007). After propensity score stratification within center, the odds ratio associated with incidence of symptomatic DVT or pulmonary embolism (PE) for patients who did and did not receive prophylactic anticoagulation was estimated using conditional logistic regression in patients who were not screened for DVT on rehabilitation admission or who screened negative; the analysis was repeated in these two subgroups. RESULTS: Patients with identified DVTs at rehabilitation admission (n = 266) were excluded, leaving 1,897 patients: 1,002 screened negative, 895 unscreened; 932 received prophylactic anticoagulation, and 965 did not. Symptomatic DVT/PE was detected in 32 patients (15 of 932 [1.6%] with prophylaxis, 17 of 965 [1.8%] without). After propensity score adjustment, the odds ratio (95% confidence interval) for symptomatic DVT/PE with prophylaxis versus no prophylaxis was 0.80 (0.33-1.94) in the full analytic population and 0.46 (0.12-1.84) in the screened-negative subgroup. The only probable venous thromboembolism-related death occurred in the prophylactic anticoagulation group. Fewer new/expanded intracranial hemorrhages occurred among patients who received prophylactic anticoagulation. CONCLUSIONS: Prophylactic anticoagulation during rehabilitation seemed safe for TBI patients whose physicians deemed it appropriate, but did not conclusively reduce venous thromboembolism. Given the number of DVTs present before rehabilitation, screening and prophylaxis during acute care may be more important.

The ineffectiveness of the Hospital Anxiety and Depression Scale for diagnosis in an Omani traumatic brain injured population.

BACKGROUND: The rehabilitation of the traumatic brain injury (TBI) patient is especially challenging in non-western populations as the phenotypic indicators as well as the neurobehavioral assessments for the survivors of brain injury are limited. OBJECTIVE: The study screened for the prevalence of anxiety and depressive states among patients with TBI and examined the validity of the Hospital Anxiety and Depression Scale (HADS) to identify TBI patients with comorbid affective dysfunctions, specifically anxiety and depressive disorders, in an Omani population. METHODS: Sixty-eight survivors of TBI were screened with the semi-structured, Composite International Diagnostic Interview (CIDI) and the HADS. A receiver operating characteristics (ROC) curve was calculated to discriminate the power of the HADS for every possible threshold score. RESULTS: The semi-structured interview revealed the prevalence rate of 57.4% for depressive disorder and 50% for anxiety disorder. The sensitivity (53.8%) and specificity 75.9%, gave the best compromise using the cut-off score of 4, suggesting HADS is not a useful screening tool for this particular population. CONCLUSIONS: Phenotypic indicators as detected by CIDI revealed that prevalence of affective dysfunctionality is common among this TBI population. Although the HADS is the most widely used screening instrument in other clinical populations, it does not appear to be a reliable resource in identifying depression and anxiety in people with traumatic brain injury in Oman.