Improved visualization of the inferior tympanic and mastoid canaliculi with photon counting detector CT.

Purpose: To compare the performance of the photon-counting detector (PCD)-CT versus a state-of-the-art energy-integrating detector (EID)-CT to identify segments of the inferior tympanic canaliculus (Jacobsons nerve) and the mastoid canaliculus (Arnolds nerve).

Materials & Methods: Patients were prospectively recruited to undergo temporal bone CT on both EID-CT (Siemens Somatom Force) and PCD-CT (Siemens NAEOTOM Alpha) scanners under an IRB-approved protocol. Three neuroradiologists reviewed cases by consensus comparing the ability to identify the proximal, mid, and distal segments of the inferior tympanic canaliculus/Jacobsons nerve and mastoid canaliculus/Arnolds nerve on each scanner using 5-point Likert scales (with 1 indicating EID is far superior to PCD, 3 indicating they are equivalent, and 5 indicating PCD is far superior to EID).

High-Resolution Head CTA: A Prospective Patient Study Comparing Image Quality of Photon-Counting Detector CT and Energy-Integrating Detector CT.

Background And Purpose: Photon-counting detector CT (PCD-CT) is now clinically available and offers ultra-high-resolution (UHR) imaging. Our purpose was to prospectively evaluate the relative image quality and impact on diagnostic confidence of head CTA images acquired by using a PCD-CT compared with an energy-integrating detector CT (EID-CT).

Materials And Methods: Adult patients undergoing head CTA on EID-CT also underwent a PCD-CT research examination.

Photon-Counting CT in the Head and Neck: Current Applications and Future Prospects.

Photon-counting detectors (PCDs) represent a major milestone in the evolution of CT imaging. CT scanners using PCD systems have already been shown to generate images with substantially greater spatial resolution, superior iodine contrast-to-noise ratio, and reduced artifact compared with conventional energy-integrating detector-based systems. These benefits can be achieved with considerably decreased radiation dose.

Imaging Findings in Giant Cell Arteritis: Don't Turn a Blind Eye to the Obvious!

Giant cell arteritis (GCA) is the most common primary large vessel systemic vasculitis in the Western World. Even though the involvement of scalp and intracranial vessels has received much attention in the neuroradiology literature, GCA, being a systemic vasculitis, can involve multiple other larger vessels including the aorta and its major head and neck branches. Herein, the authors present a pictorial review of the various cranial, extracranial, and orbital manifestations of GCA.

Model-based iterative reconstruction for direct imaging with point spread function encoded echo planar MRI.

Background: Echo planar imaging (EPI) is a fast measurement technique commonly used in magnetic resonance imaging (MRI), but is highly sensitive to measurement non-idealities in reconstruction. Point spread function (PSF)-encoded EPI is a multi-shot strategy which alleviates distortion, but acquisition of encodings suitable for direct distortion-free imaging prolongs scan time. In this work, a model-based iterative reconstruction (MBIR) framework is introduced for direct imaging with PSF-EPI to improve image quality and acceleration potential.

Dorsal arachnoid web adjacent to paraspinal retained bullet: Blunt post-traumatic etiology.

Dorsal arachnoid webs are uncommon, and of uncertain etiology. We present a case in which imaging findings of a dorsal arachnoid web were identified at the level of a known prior gunshot injury where a retained bullet was lodged adjacent to the spine, without associated penetrating injury to the spine, suggesting blunt post-traumatic etiology.

Impact of e-ASPECTS software on the performance of physicians compared to a consensus ground truth: a multi-reader, multi-case study.

Background: The Alberta Stroke Program Early CT Score ASPECTS) is used to quantify the extent of injury to the brain following acute ischemic stroke (AIS) and to inform treatment decisions. The e-ASPECTS software uses artificial intelligence methods to automatically process non-contrast CT (NCCT) brain scans from patients with AIS affecting the middle cerebral artery (MCA) territory and generate an ASPECTS. This study aimed to evaluate the impact of e-ASPECTS (Brainomix, Oxford, UK) on the performance of US physicians compared to a consensus ground truth.

Volumetric T -weighted spin echo imaging with improved SNR using localized quadratic encoding and a spiral readout trajectory.

Purpose: To demonstrate T -weighted (single-echo) spin-echo (SE) imaging with near-optimal acquisition efficiency by applying SNR-efficient RF slice encoding and spiral readout.

Methods: A quadratic-phase (frequency swept) excitation RF pulse replaced the conventional excitation in T -weighted SE sequence to excite a thick slab that is internally spatially encoded by a variable phase along the slice direction. Highly overlapping slabs centered at every desired slice location were acquired in multiple passes, such that the entire imaging volume was excited by contiguous slabs in any given pass.

High-resolution computed tomography angiography of the orbit using a photon-counting computed tomography scanner.

Background And Purpose: Recent introduction of photon counting detector (PCD) computed tomography (CT) scanners into clinical practice further improve CT angiography (CTA) depiction of orbital arterial vasculature compared to conventional energy integrating detector (EID) CT scanners. PCD-CTA of the orbit can provide a detailed arterial roadmap of the orbit which can de diagnostic on its own or serve as a helpful planning adjunct for both diagnostic and therapeutic catheter-based angiography of the orbit.

Methods: For this review, EID and PCD-CT imaging was obtained in 28 volunteers.

Dorsoventral splitting of the infundibulum in a child with pituitary hypoplasia.

Pituitary development arises from ectodermal tissue creating Rathke's pouch and ultimately the adenohypophysis anteriorly whereas neuroectodermal tissue arising from the diencephalon creates the neurohypophysis posteriorly. Alterations in pituitary development can lead to hormonal dysregulation and dysfunction. Following clinical suspicion of pituitary endocrinopathy, MRI plays a vital role in identifying and characterizing underlying structural abnormalities of the pituitary gland, as well as any associated extrapituitary findings.

Technical note: Improved differentiation of calcification from hemosiderin using paramagnetic- and diamagnetic-specific magnetic resonance susceptibility weighted imaging (p-SWI, d-SWI).

Introduction: Differentiation of calcification and calcium-containing tissue from blood products remains challenging using magnetic resonance imaging (MRI). We developed a novel post-processing algorithm which creates both paramagnetic- and diamagnetic-specific SWI images generated from T2* weighted images using distinct "positive" and "negative" phase masks.

Methods: 10 patients who had undergone clinical MRI scanning of the brain with a rapid echo planar based T2*-weighted EPI-GRE pulse sequence with evidence for either hemosiderin and/or calcifications were retrospectively identified.

Automated CT angiography collateral scoring in anterior large vessel occlusion stroke: A multireader study.

Background: Computed tomography (CT) angiography collateral score (CTA-CS) is an important clinical outcome predictor following mechanical thrombectomy for ischemic stroke with large vessel occlusion (LVO). The present multireader study aimed to evaluate the performance of e-CTA software for automated assistance in CTA-CS scoring.

Materials And Methods: Brain CTA images of 56 patients with anterior LVO were retrospectively processed.

Evaluation of a New, Highly Flexible Radiofrequency Coil for MR Simulation of Patients Undergoing External Beam Radiation Therapy.

Purpose: To evaluate the performance of a new, highly flexible radiofrequency (RF) coil system for imaging patients undergoing MR simulation.

Methods: Volumetric phantom and in vivo images were acquired with a commercially available and prototype RF coil set. Phantom evaluation was performed using a silicone-filled humanoid phantom of the head and shoulders.

Enhanced clinical task-based fMRI metrics through locally low-rank denoising of complex-valued data.

Objective: This study investigates a locally low-rank (LLR) denoising algorithm applied to source images from a clinical task-based functional MRI (fMRI) exam before post-processing for improving statistical confidence of task-based activation maps.

Methods: Task-based motor and language fMRI was obtained in eleven healthy volunteers under an IRB approved protocol. LLR denoising was then applied to raw complex-valued image data before fMRI processing.

Loeys-Dietz syndrome: Case report and review of the literature.

Loeyz-Dietz syndrome (LDS) is a genetic connective tissue disorder characterized by various clinical manifestations, most notably vasculopathies and skeletal abnormalities. The disease is rare, and has multiple overlapping features with other connective tissue disorders. As such, many radiologists remain unfamiliar with the imaging and clinical findings in LDS.

Improved Brain MR Imaging from a Compact, Lightweight 3T Scanner with High-Performance Gradients.

Background: A low-cryogen, compact  3T (C3T) MRI scanner with high-performance gradients capable of simultaneously achieving 80 mT/m gradient amplitude and 700 T/m/second slew rate has been in use to study research patients since March 2016 but has not been implemented in the clinical practice.

Purpose: To compare head MRI examinations obtained with the C3T system and a conventional whole-body  3T (WB3T) scanner in seven parameters across five commonly used brain imaging sequences.

Study Type: Prospective.

Implementation and Rationale for a Unified Clinical and Imaging Protocol for Evaluation and Treatment of Moyamoya Angiopathy: A Single Institutional Experience.

Moyamoya disease (MMD) is a complex and incompletely-understood cerebrovascular pathological entity that requires thorough clinical and imaging evaluation. Moyamoya is rare, thereby making the establishment of an effective, thorough and interdisciplinary patient evaluation protocol challenging, even within specialized referral centers. Nevertheless, implementation of such a protocol is crucial in order to provide the best possible evaluation and treatment for MMD patients.

Whole brain 3D MR fingerprinting in multiple sclerosis: a pilot study.

Background: MR fingerprinting (MRF) is a novel imaging method proposed for the diagnosis of Multiple Sclerosis (MS). This study aims to determine if MR Fingerprinting (MRF) relaxometry can differentiate frontal normal appearing white matter (F-NAWM) and splenium in patients diagnosed with MS as compared to controls and to characterize the relaxometry of demyelinating plaques relative to the time of diagnosis.

Methods: Three-dimensional (3D) MRF data were acquired on a 3.

Whole-brain 3D MR fingerprinting brain imaging: clinical validation and feasibility to patients with meningioma.

Purpose: MR fingerprinting (MRF) is a MR technique that allows assessment of tissue relaxation times. The purpose of this study is to evaluate the clinical application of this technique in patients with meningioma.

Materials And Methods: A whole-brain 3D isotropic 1mm acquisition under a 3.

e-ASPECTS software improves interobserver agreement and accuracy of interpretation of aspects score.

Introduction: There is increased interest in the use of artificial intelligence-based (AI) software packages in the evaluation of neuroimaging studies for acute ischemic stroke. We studied whether, compared to standard image interpretation without AI, Brainomix e-ASPECTS software improved interobserver agreement and accuracy in detecting ASPECTS regions affected in anterior circulation LVO.

Methods: We included 60 consecutive patients with anterior circulation LVO who had TICI 3 revascularization within 60 minutes of their baseline CT.

Arterial Spin Labeling Applications in Pediatric and Adult Neurologic Disorders.

Arterial spin labeling (ASL) is a powerful noncontrast magnetic resonance imaging (MRI) technique that enables quantitative evaluation of brain perfusion. To optimize the clinical and research utilization of ASL, radiologists and physicists must understand the technical considerations and age-related variations in normal and disease states. We discuss advanced applications of ASL across the lifespan, with example cases from children and adults covering a wide variety of pathologies.

Application of Adaptive Image Receive Coil Technology for Whole-Brain Imaging.

The Adaptive Image Receive (AIR) radiofrequency coil is an emergent technology that is lightweight and flexible and exhibits electrical characteristics that overcome many of the limitations of traditional rigid coil designs. The purpose of this study was to apply the AIR coil for whole-brain imaging and compare the performance of a prototype AIR coil array with the performance of conventional head coils. A phantom and 15 healthy adult participants were imaged.