Identification of a Single-Dose, Low-Flip-Angle-Based CBV Threshold for Fractional Tumor Burden Mapping in Recurrent Glioblastoma.

Background And Purpose: DSC-MR imaging can be used to generate fractional tumor burden (FTB) maps via application of relative CBV thresholds to spatially differentiate glioblastoma recurrence from posttreatment radiation effects (PTRE). Image-localized histopathology was previously used to validate FTB maps derived from a reference DSC-MR imaging protocol by using preload, a moderate flip angle (MFA, 60°), and postprocessing leakage correction. Recently, a DSC-MR imaging protocol with a low flip angle (LFA, 30°) with no preload was shown to provide leakage-corrected relative CBV (rCBV) equivalent to the reference protocol.

A 3D dual-echo spiral sequence for simultaneous dynamic susceptibility contrast and dynamic contrast-enhanced MRI with single bolus injection.

Purpose: Perfusion MRI reveals important tumor physiological and pathophysiologic information, making it a critical component in managing brain tumor patients. This study aimed to develop a dual-echo 3D spiral technique with a single-bolus scheme to simultaneously acquire both dynamic susceptibility contrast (DSC) and dynamic contrast-enhanced (DCE) data and overcome the limitations of current EPI-based techniques.

Methods: A 3D spiral-based technique with dual-echo acquisition was implemented and optimized on a 3T MRI scanner with a spiral staircase trajectory and through-plane SENSE acceleration for improved speed and image quality, in-plane variable-density undersampling combined with a sliding-window acquisition and reconstruction approach for increased speed, and an advanced iterative deblurring algorithm.

Rapid -weighted MRI using multishot EPI with retrospective motion and phase correction in the emergency department.

Purpose: Brain MRI is increasingly used in the emergency department (ED), where -weighted MRI is an essential tool for detecting hemorrhage and stroke. The goal of this study was to develop a rapid -weighted MRI technique capable of correcting motion-induced artifacts, thereby simultaneously improving scan time and motion robustness for ED applications.

Methods: A 2D gradient-echo (GRE)-based multishot EPI (msEPI) technique was implemented using a navigator echo for estimating motion-induced errors.

Evaluation of Motion-Corrected Multishot Echo-Planar Imaging as an Alternative to Gradient Recalled-Echo for Blood-Sensitive Imaging.

We evaluated motion-corrected multishot EPI compared with gradient recalled-echo imaging to determine whether it can be used as a faster technique for blood-sensitive imaging in the emergency department setting. Multishot EPI was found to be superior to gradient recalled-echo (< .05) in motion artifacts, overall image quality, and lesion detection.

Low-Dose Whole Brain Radiation Therapy for Alzheimer's Dementia: Results From a Pilot Trial in Humans.

Purpose: We report neurocognitive, imaging, ophthalmologic, and safety outcomes following low-dose whole brain radiation therapy (LD-WBRT) for patients with early Alzheimer dementia (eAD) treated in a pilot trial.

Methods And Materials: Trial-enrolled patients were at least 55 years of age, had eAD meeting NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association) Alzheimer's Criteria with confirmatory fluorodeoxyglucose and florbetapir positron emission tomography findings; had the capacity to complete neurocognitive function, psychological function, and quality-of-life assessments; had a Rosen modified Hachinski score ≤4; and had estimated survival >12 months.

Results: Five patients were treated with LD-WBRT (2 Gy × 5 over 1 week; 3 female; mean age, 73.

Identification of single-dose, dual-echo based CBV threshold for fractional tumor burden mapping in recurrent glioblastoma.

Background: Relative cerebral blood volume (rCBV) obtained from dynamic susceptibility contrast (DSC) MRI is widely used to distinguish high grade glioma recurrence from post treatment radiation effects (PTRE). Application of rCBV thresholds yield maps to distinguish between regional tumor burden and PTRE, a biomarker termed the fractional tumor burden (FTB). FTB is generally measured using conventional double-dose, single-echo DSC-MRI protocols; recently, a single-dose, dual-echo DSC-MRI protocol was clinically validated by direct comparison to the conventional double-dose, single-echo protocol.

Rapid whole-brain myelin imaging with selective inversion recovery and compressed SENSE.

Purpose: Quantitative magnetization transfer (QMT) using selective inversion recovery (SIR) can quantify the macromolecular-to-free proton pool size ratio (PSR), which has been shown to relate closely with myelin content. Currently clinical applications of SIR have been hampered by long scan times. In this work, the acceleration of SIR-QMT using CS-SENSE (compressed sensing SENSE) was systematically studied.

Technical note: A spiral fluid-attenuated inversion recovery magnetic resonance imaging technique for stereotactic radiosurgery treatment planning for trigeminal neuralgia.

Purpose: Magnetic resonance imaging (MRI) is commonly used in treatment planning for stereotactic radiosurgery (SRS) of trigeminal neuralgia (TN). With current MRI techniques, the delineation of the trigeminal nerve root entry zone (REZ) may be degraded due to poor contrast and artifacts. The purpose of this work is to develop an MRI technique with better delineation of the trigeminal nerve REZ to improve SRS treatment planning for TN.

Evaluation of single bolus, dual-echo dynamic susceptibility contrast MRI protocols in brain tumor patients.

Relative cerebral blood volume (rCBV) obtained from dynamic susceptibility contrast (DSC) MRI is adversely impacted by contrast agent leakage in brain tumors. Using simulations, we previously demonstrated that multi-echo DSC-MRI protocols provide improvements in contrast agent dosing, pulse sequence flexibility, and rCBV accuracy. The purpose of this study is to assess the performance of dual-echo acquisitions in patients with brain tumors (n = 59).

Development of a spiral spin- and gradient-echo (spiral-SAGE) approach for improved multi-parametric dynamic contrast neuroimaging.

Purpose: The purpose of this study was to develop a spiral-based combined spin- and gradient-echo (spiral-SAGE) method for simultaneous dynamic contrast-enhanced (DCE-MRI) and dynamic susceptibility contrast MRI (DSC-MRI).

Methods: Using this sequence, we obtained gradient-echo TEs of 1.69 and 26 ms, a SE TE of 87.

Imaging of Neurotrauma in Acute and Chronic Settings.

Traumatic injuries of the brain and spinal cord are a significant source of mortality and long-term disability. A recent systematic study in a rat model of spinal cord injury (SCI) indicates severe, destructive, and very protracted inflammation as the key mechanism initiated by the massive injury involving the white matter. Although the severe inflammation is localized and counteracted by astrogliosis, it has a damaging effect on the blood vessels in the surrounding spinal cord, leading to persistent vasogenic edema.

Incidental Finding of a Large Right Atrial Thrombus in a Patient With Cerebral Lymphoma.

Right atrial (RA) masses are rare, challenging to diagnose, and potentially life-threatening with high mortality if untreated. We present a patient presenting with diffuse large B-cell lymphoma in the brain that was incidentally found to have a large RA mass. For a better definition of the RA mass, extensive workup using multimodality imaging including chest computed tomography, transthoracic echocardiography, transesophageal echocardiography, cardiac magnetic resonance imaging, and left heart catheterization was warranted.

Prolonged inflammation leads to ongoing damage after spinal cord injury.

The pathogenesis of spinal cord injury (SCI) remains poorly understood and treatment remains limited. Emerging evidence indicates that post-SCI inflammation is severe but the role of reactive astrogliosis not well understood given its implication in ongoing inflammation as damaging or neuroprotective. We have completed an extensive systematic study with MRI, histopathology, proteomics and ELISA analyses designed to further define the severe protracted and damaging inflammation after SCI in a rat model.

Spiral T1 Spin-Echo for Routine Postcontrast Brain MRI Exams: A Multicenter Multireader Clinical Evaluation.

Background And Purpose: Spiral MR imaging has several advantages compared with Cartesian MR imaging that can be leveraged for added clinical value. A multicenter multireader study was designed to compare spiral with standard-of-care Cartesian postcontrast structural brain MR imaging on the basis of relative performance in 10 metrics of image quality, artifact prevalence, and diagnostic benefit.

Materials And Methods: Seven clinical sites acquired 88 total subjects.

Long-term outcome data from 121 patients treated with Gamma Knife stereotactic radiosurgery as salvage therapy for focally recurrent high-grade gliomas.

Introduction: We examined patient outcomes after Gamma Knife stereotactic radiosurgery (GKSRS) salvage therapy for recurrent high-grade gliomas (HGGs) to determine whether tumor grade or lesion size affected overall survival (OS) and progression-free survival (PFS).

Methods: This single-center retrospective study assessed radiographic response and clinical outcomes following GKSRS salvage treatment of recurrent malignant gliomas (January 2005-March 2014).

Results: A total of 121 patients (67 female) with 132 tumors were treated.

Improving the image quality of 3D FLAIR with a spiral MRI technique.

Purpose: Fluid-attenuated inversion recovery (FLAIR) nulls the CSF signal and is widely used in neuro MRI exams. A 3D scan can provide high SNR, contiguous coverage, and reduced sensitivity to through-plane CSF flow. In this work, a 3D spiral FLAIR technique is proposed to improve the image quality of conventional 3D Cartesian FLAIR.

Ten-year analysis of saccular aneurysms in the Barrow Ruptured Aneurysm Trial.

Objective: The authors present the 10-year results of the Barrow Ruptured Aneurysm Trial (BRAT) for saccular aneurysms. The 1-, 3-, and 6-year results of the trial have been previously reported, as have the 6-year results with respect to saccular aneurysms. This final report comparing the safety and efficacy of clipping versus coiling is limited to an analysis of those patients presenting with subarachnoid hemorrhage (SAH) from a ruptured saccular aneurysm.

Accurate Patient-Specific Machine Learning Models of Glioblastoma Invasion Using Transfer Learning.

Background And Purpose: MR imaging-based modeling of tumor cell density can substantially improve targeted treatment of glioblastoma. Unfortunately, interpatient variability limits the predictive ability of many modeling approaches. We present a transfer learning method that generates individualized patient models, grounded in the wealth of population data, while also detecting and adjusting for interpatient variabilities based on each patient's own histologic data.

Procedural Variables Influencing Stereotactic Accuracy and Efficiency in Deep Brain Stimulation Surgery.

Background: Deep brain stimulation (DBS) is well-established, evidence-based therapy for Parkinson disease, essential tremor, and primary dystonia. Clinical outcome studies have recently shown that "asleep" DBS lead placement, performed using intraoperative imaging with stereotactic accuracy as the surgical endpoint, has motor outcomes comparable to traditional "awake" DBS using microelectrode recording (MER), but with shorter case times and improved speech fluency.

Objective: To identify procedural variables in DBS surgery associated with improved surgical efficiency and stereotactic accuracy.

Spinal Coccidioidomycosis: MR Imaging Findings in 41 Patients.

Background And Purpose: is a dimorphic fungus endemic to the Southwest United States and Mexico, and at our institution, it is a relatively common pathogen presenting with a broad spectrum of associated spine diseases. We describe the various spinal manifestations resulting from coccidioidal infection and provide MR imaging examples from 41 pathologically proved cases.

Materials And Methods: Retrospective electronic medical record and PACS searches were performed.

A 2D spiral turbo-spin-echo technique.

Purpose: 2D turbo-spin-echo (TSE) is widely used in the clinic for neuroimaging. However, the long refocusing radiofrequency pulse train leads to high specific absorption rate (SAR) and alters the contrast compared to conventional spin-echo. The purpose of this work is to develop a robust 2D spiral TSE technique for fast T -weighted imaging with low SAR and improved contrast.

Improving the utility of H-MRS for the differentiation of glioma recurrence from radiation necrosis.

Proton magnetic resonance spectroscopy (H-MRS) has shown promise in distinguishing recurrent high-grade glioma from posttreatment radiation effect (PTRE). The purpose of this study was to establish objective H-MRS criteria based on metabolite peak height ratios to distinguish recurrent tumor (RT) from PTRE. A retrospective analysis of magnetic resonance imaging and H-MRS data was performed.

Introduction of a Dedicated Emergency Department MR Imaging Scanner at the Barrow Neurological Institute.

Use of advanced imaging in the emergency department has been increasing in the United States during the past 2 decades. This trend has been most notable in CT, which has increased concern over the effects of increasing levels of medical ionizing radiation. MR imaging offers a safe, nonionizing alternative to CT and is diagnostically superior in many neurologic conditions encountered in the emergency department.