Impaired pharyngeal reflex responses to negative pressure: a novel cause of sleep apnea in multiple sclerosis.

Obstructive sleep apnea (OSA) is common in people with multiple sclerosis (MS). However, people with MS often do not have "typical" anatomical risk factors (i.e.

Haemorrhage and Calcification on Susceptibility-Weighted Imaging : A Quick and Reliable Qualitative Technique for Differentiating Lesions with Ambiguous Phase.

Purpose: Haemorrhage and calcification can be qualitatively distinguished on susceptibility-weighted imaging (SWI) using phase information, but it is unclear how to make this distinction in a subset of lesions with ambiguous phase, containing a mixture of positive and negative values. This work investigates the validity of qualitative phase assessment at the cranial or caudal margins in classifying such lesions as haemorrhagic or calcific, when quantitative susceptibility mapping is not available to the neuroradiologist.

Methods: In a retrospective review of magnetic resonance imaging examinations acquired between July 2015 and November 2019, 87 lesions with ambiguous phase which could be confidently determined to be haemorrhagic or calcific were identified.

The effect of JPEG2000 compression on detection of skull fractures.

Rational And Objectives: To investigate the effect of the Joint Photographic Experts Group (JPEG2000) 30:1 and 60:1 lossy compression on the detection of cranial vault fractures when compared to JPEG2000 lossless compression.

Materials And Methods: Fifty cranial computed tomography (CT) images were processed with three different level of JPEG2000 compression (lossless, 30:1 lossy, and 60:1 lossy) creating three sets of images. These were presented to five musculoskeletal specialists and five neuroradiologists.

Assessing signal intensity change on well-registered images: comparing subtraction, color-encoded subtraction, and parallel display formats.

Purpose: To assess the sensitivity, specificity, accuracy, and interobserver reliability of subtraction, color-encoded subtraction, and parallel display formats in assessing signal intensity (SI) differences between well-registered images.

Materials And Methods: Institutional ethics approval for the study and a waiver of individual patient consent were obtained. Five radiologists graded the severity of fatty liver by using a seven-point scale for four imaging sets created from 179 pairs of dual-echo in- and opposed-phase magnetic resonance images from 179 patients.

MR imaging characteristics of protoplasmic astrocytomas.

Introduction: Protoplasmic astrocytomas are a poorly recognized and uncommon subtype of astrocytoma. While usually categorized with other low-grade gliomas, there is literature to suggest that protoplasmic astrocytomas have differences in biology compared to other gliomas in this group. This paper presents the MR imaging characteristics of a series of eight protoplasmic astrocytomas.