A new design and rationale for 3D orthogonally oversampled k‐space trajectories

A novel center‐out 3D trajectory for sampling magnetic resonance data is presented. The trajectory set is based on a single Fermat spiral waveform, which is substantially undersampled in the center of k‐space. Multiple trajectories are combined in a “stacked cone” configuration to give very uniform sampling throughout a “hub,” which is very efficient in terms of gradient performance and uniform trajectory spacing. The fermat looped, orthogonally encoded trajectories (FLORET) design produces less gradient‐efficient trajectories near the poles, so multiple orthogonal hub designs are shown. These multihub designs oversample k‐space twice with orthogonal trajectories, which gives unique properties but also doubles the minimum scan time for critical sampling of k‐space. The trajectory is shown to be much more efficient than the conventional stack of cones trajectory, and has nearly the same signal‐to‐noise ratio efficiency (but twice the minimum scan time) as a stack of spirals trajectory. As a center‐out trajectory, it provides a shorter minimum echo time than stack of spirals, and its spherical k‐space coverage can dramatically reduce Gibbs ringing. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.     

Brain contusion with aphasia following an ice hockey injury

Head injuries are relatively common in ice hockey, with the majority represented by concussions, a form of mild traumatic brain injury. More severe head injuries are rare since the implementation of mandatory helmet use in the 1960s. We present a case of a 27 year-old male who sustained a traumatic intraparenchymal hemorrhage with an associated subdural hematoma resulting after being struck by a puck shot at high velocity. The patient presented with expressive aphasia, with no other apparent neurologic deficits. Acutely, he was successfully treated with observation and serial neuroimaging studies ensuring an absence of hematoma expansion. After a stable clinical picture following 24 hours of observation, the patient was discharged and managed with outpatient speech therapy with full resolution of symptoms and return to play 3 months later. We will outline the patient presentation and pertinent points in the management of acute head injuries in athletes.     

CT colonography and transient bacteraemia: implications for antibiotic prophylaxis

Objectives  

To determine the prevalence of transient bacteraemia after CT colonography (CTC).     

Outcome of isolated posterior cruciate ligament reconstruction at mean 6.3-year follow up: a consecutive case series

Objectives: There is a paucity of reporting on surgical outcomes of isolated posterior cruciate ligament reconstruction (PCLR). We hypothesize that isolated PCL injuries failing nonoperative treatment achieve good outcomes and are able to return to sport following PCLR.

Methods: A retrospective analysis was performed to identify patients with isolated PCL injuries that underwent reconstruction between 2001 and 2014. Patients with multi-ligamentous injury or another concomitant knee pathology were excluded. Medical records were reviewed for demographic, clinical and operative data. Patients were contacted for administration of a telephone-based questionnaire which included the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation form, Lysholm-Tegner scales, Marx activity scale (MAS), return to sport status, and patient satisfaction instruments.

Results: A total of 15 isolated PCL reconstructions in 14 patients with a mean age of 27.5 years (range 17–43) met the study inclusion criteria; mean follow up was 6.3 years (range 1.4–15.2). Pre-operatively, the primary complaint was knee instability in all patients; on physical examination, lack of a firm end point during posterior drawer testing was found in 93% (14/15) of the knees. In total, 12 of 15 knees underwent transtibial, single-bundle PCLR and three of 15 underwent tibial inlay, double bundle PCLR. Graft types included: quadriceps autograft (7/15), Achilles allograft (6/15), and hamstring autograft (2/15). There were no graft failures in our patient cohort. At most recent follow up the mean scores respectively on the IKDC form, Lysholm-Tegner scales and MAS were (standard deviation): 77.3 (16.5), 83.1 (17.9), 6.13 (2.6), and 7.1 (6.0). All fourteen patients were athletes prior to their injury and 79% (11/14) returned to sport and overall patient satisfaction was 9.2/10.

Conclusions: Isolated PCLR provides good outcomes at mean medium-term follow up with restoration of function, high rate of return to sport and overall patient satisfaction.     

Massively parallel sequencing for the forensic scientist – sequencing archived amplified products of AmpFlSTR Identifiler and PowerPlex Y multiplex kits to capture additional information

In the last few years the cost and ease of massively parallel sequencing (MPS) has reduced dramatically to the point that it can now be considered as a tool for use in forensic case work. An important consideration for the implementation of any new forensic technology is the ability to remain compatible with previous technology. During this study we sequenced the amplicons of two commercial forensic short tandem repeat (STR) multiplexes AmpFlSTR Identifiler and PowerPlex Y using the Illumina MiSeq and Ion PGM Sequencer (Life Technologies) and characterised the sequence data from a forensic perspective. Using the MPS data from both platforms we determined the STR genotypes of forensic samples and found previously undocumented sequence variation in seven STR alleles. By characterising features of the DNA sequence profiles, such as stutter and locus imbalance we identified areas for future development that will be needed prior to casework implementation. The rapid development of this technology has meant many in the forensic community have been ‘left behind’. We also provide an explanation, for forensic scientists, of what is happening at the different stages of the MPS workflow, from library preparation through to bioinformatics, and how this may affect the results.     

Comparison of baseline and post-concussion ImPACT test scores in young athletes with stimulant-treated and untreated ADHD

Objectives: Baseline and post-concussion neurocognitive testing is useful in managing concussed athletes. Attention deficit hyperactivity disorder (ADHD) and stimulant medications are recognized as potential modifiers of performance on neurocognitive testing by the Concussion in Sport Group. Our goal was to assess whether individuals with ADHD perform differently on post-concussion testing and if this difference is related to the use of stimulants.

Methods: Retrospective case-control study in which 4373 athletes underwent baseline and post-concussion testing using the ImPACT battery. 277 athletes self-reported a history of ADHD, of which, 206 reported no stimulant treatment and 69 reported stimulant treatment. Each group was matched with participants reporting no history of ADHD or stimulant use on several biopsychosocial characteristics. Non-parametric tests were used to assess ImPACT composite score differences between groups.

Results: Participants with ADHD had worse verbal memory, visual memory, visual motor speed, and reaction time scores than matched controls at baseline and post-concussion, all with p ≤ .001 and |r|≥ 0.100. Athletes without stimulant treatment had lower verbal memory, visual memory, visual motor speed, and reaction time scores than controls at baseline (p ≤ 0.01, |r|≥ 0.100 [except verbal memory, r = ?0.088]) and post-concussion (p = 0.000, |r|> 0.100). Athletes with stimulant treatment had lower verbal memory (Baseline: p = 0.047, r = ?0.108; Post-concussion: p = 0.023, r = ?0.124) and visual memory scores (Baseline: p = 0.013, r = ?0.134; Post-concussion: p = 0.003, r = ?0.162) but equivalent visual motor speed and reaction time scores versus controls at baseline and post-concussion.

Conclusions: ADHD-specific baseline and post-concussion neuropsychological profiles, as well as stimulant medication status, may need to be considered when interpreting ImPACT test results. Further investigation into the effects of ADHD and stimulant use on recovery from sport-related concussion (SRC) is warranted.     

Relative Initial Weight Is Associated with Improved Survival without Altering Tumor Latency in a Translational Rat Model of Diethylnitrosamine-Induced Hepatocellular Carcinoma and Transarterial Embolization

Purpose

To test the hypotheses that (i) heavier rats demonstrate improved survival with diminished fibrosis in a diethylnitrosamine (DEN)-induced model of hepatocellular carcinoma (HCC) and (ii) transarterial embolization via femoral artery access decreases procedure times versus carotid access.

Radiation Dose Reduction during Uterine Fibroid Embolization Using an Optimized Imaging Platform

Purpose

To assess radiation dose reduction during uterine fibroid embolization (UFE) using an optimized angiographic processing and acquisition platform.

Canine visceral leishmaniasis in Sicily

The Sicilian province of Catania is an active foci for human visceral leishmaniasis (VL) in the Mediterranean area. Approximately 10 to 15 cases of VL are diagnosed via hospital admissions each year in this community. Recently, an increase in VL case reporting by Sicilian physicians was noted, with 38 and 37 VL cases in 1996 and 1997, respectively. Before 1995, there were no reported VL cases among U.S. military personnel or their family members living in Sicily. However, since 1996, there have been four cases referred to Walter Reed Army Medical Center for diagnosis and treatment, all involving the children of personnel assigned to Naval Air Station Sigonella. Exposure histories for all infected individuals excluded exposure to Leishmania parasites outside of Sicily. All patients lived in areas where vectoring sandflies are present. All had dogs as family pets. To evaluate the level of infection among dogs owned by Navy personnel and their families, U.S. Navy Environmental and Preventive Medicine Unit 7, in a collaborative study with the U.S. Army Veterinary Clinic, Naval Air Station Sigonella, and the Walter Reed Army Institute of Research, performed clinical evaluation and serological testing of 50 dogs residing with U.S. personnel assigned to Naval Air Station Sigonella. The data indicate a high exposure rate to Leishmania (60% of the animals tested had elevated immunoglobulin M antibody levels) in the study population, suggesting that they were infected with Leishmania infantum. Distribution of seropositive dogs by sex was equal. Most of the dogs studied appeared to be in good health. However, inapparent infection of dogs, seen by Italian veterinarians, has been observed throughout all areas of Catania. Sandflies responsible for vectoring L. infantum were trapped in the same locations as the dogs sampled in this study. The level of subclinical infection was 75% among seropositive dogs. The overall level of canine infection observed was higher than expected. This study demonstrates an increased risk to military working dogs and companion dogs of U.S. personnel for infection with L. infantum during a 2- to 3-year tour in Sicily.     

A detailed evaluation of TomoDirect 3DCRT planning for whole-breast radiation therapy

The goal of this work was to develop planning strategies for whole-breast radiotherapy (WBRT) using TomoDirect three-dimensional conformal radiation therapy (TD-3DCRT) and to compare TD-3DCRT with conventional 3DCRT and TD intensity-modulated radiation therapy (TD-IMRT) to evaluate differences in WBRT plan quality. Computed tomography (CT) images of 10 women were used to generate 150 WBRT plans, varying in target structures, field width (FW), pitch, and number of beams. Effects on target and external maximum doses (EMD), organ-at-risk (OAR) doses, and treatment time were assessed for each parameter to establish an optimal planning technique. Using this technique, TD-3DCRT plans were generated and compared with TD-IMRT and standard 3DCRT plans. FW 5.0 cm with pitch = 0.250 cm significantly decreased EMD without increasing lung V20 Gy. Increasing number of beams from 2 to 6 and using an additional breast planning structure decreased EMD though increased lung V20 Gy. Changes in pitch had minimal effect on plan metrics. TD-3DCRT plans were subsequently generated using FW 5.0 cm, pitch = 0.250 cm, and 2 beams, with additional beams or planning structures added to decrease EMD when necessary. TD-3DCRT and TD-IMRT significantly decreased target maximum dose compared to standard 3DCRT. FW 5.0 cm with 2 to 6 beams or novel planning structures or both allow for TD-3DCRT WBRT plans with excellent target coverage and OAR doses. TD-3DCRT plans are comparable to plans generated using TD-IMRT and provide an alternative to conventional 3DCRT for WBRT.