Development and validation of a practical solution for detecting motion artefacts in the EOS X-ray system.

The EOS™2D/3D system is a low-dose, 3D imaging system that utilizes two perpendicular X-ray beams to create simultaneous frontal and lateral images of the body. This is a useful modality to assess spinal pathologies. However, due to the slow imaging acquisition time up to 25 s, motion artifacts (MA) frequently occur. These artifacts may not be distinguishable from pathological findings, such as scoliosis, and may impair the diagnostic process. The aim of this study was to design a method to detect MA in EOS X-ray. We retrospectively analyzed EOS imaging from 40 patients wearing a radiopaque reference device during imaging. We drew a straight vertical line along the reference device. We measured deviations from it to quantify MA, presenting these findings through descriptive statistics. For a subset of patients with high MA, acquisitions were repeated after giving specific instructions to stand still. For these patients, we compared MA between the two acquisitions. In our study, a substantial proportion of patients exhibited MA ≥ 1 mm, with 80% in frontal projections and 87.9% in lateral projections. In the subjects who received a second acquisition, MA was significantly lower in the second images. Our method allows for a precise detection of MA on EOS images through a simple, yet reliable solution. Our method may improve the reliability of spine measurements, and reduce the risk of wrong diagnosis due to low imaging quality.

Glutathione in the Pons Is Associated With Clinical Status Improvements in Subacute Spinal Cord Injury.

OBJECTIVES: In spinal cord injury (SCI), the primary mechanical injury is followed by secondary sequelae that develop over the subsequent months and manifests in biochemical, functional, and microstructural alterations, at the site of direct injury but also in the spinal cord tissue above and below the actual lesion site. Noninvasive magnetic resonance spectroscopy (MRS) can be used to assess biochemical modulation occurring in the secondary injury phase, in addition to and supporting conventional MRI, and might help predict and improve patient outcome. In this article, we aimed to examine the metabolic levels in the pons of subacute SCI by means of in vivo proton MRS at 3 T and explore the association to clinical scores. MATERIALS AND METHODS: In this prospective study, between November 2015 and February 2018, single-voxel short-echo MRS data were acquired in healthy controls and in SCI subjects in the pons once during rehabilitation. Besides the single-point MRS examination, in addition, in participants with SCI, the clinical status (ie, motor, light touch, and pinprick scores) was assessed twice: (1) around the MRS session (approximately 10 weeks postinjury) and (2) before discharge (at approximately 9 months postinjury). The group differences were assessed with Kruskal-Wallis test, the post hoc comparison was assessed with Wilcoxon rank sum test, and the clinical correlations were conducted with Spearman rank correlation test. Bayes factor calculations completed the statistical part providing relevant evidence values. RESULTS: Twenty healthy controls (median age, 50 years; interquartile range, 41-55 years; 18 men) and 18 subjects with traumatic SCI (median age, 50 years; interquartile range, 32-58 years; 16 men) are included. Group comparison showed an increase of total N -acetylaspartate and combined glutamate and glutamine levels in complete SCI and a reduction of total creatine in incomplete paraplegic SCI. The proton MRS-based glutathione levels at baseline correlate to the motor score improvement during rehabilitation in incomplete subacute SCI. CONCLUSIONS: This exploratory study showed an association of the metabolite concentration of glutathione in the pons assessed at approximately 10 weeks after injury with the improvements of the motor score during the rehabilitation. Pontine glutathione levels in subjects with traumatic subacute incomplete SCI acquired remote from the injury site correlate to clinical score and might therefore be beneficial in the rehabilitation assessments.

Extended periprostatic nerve distributions on the prostate surface confirmed using diffusion tensor imaging.

OBJECTIVE: To perform a descriptive microscopic study of prostatectomy specimens from 19 patients which anatomically characterizes the distributions of periprostatic nerve qualities, and to visualize these using diffusion tensor imaging (DTI). MATERIALS AND METHODS: Serial whole-mounted sections were stained for cholinergic (neuronal nitric oxide synthase), adrenergic (tyrosine hydroxylase) and sensory (calcitonin gene-related peptide) nerves. Extracapsular stained nerves were counted by prostate surface sector, and classified by diameter. Stain-related relative density was calculated, and distribution patterns were evaluated. To better visualize the reported neuronal structures and independently confirm our findings, nerve concordance in five male volunteers was investigated using a 3-Tesla magnetic resonance imaging-DTI system. RESULTS: At the base, cholinergic nerves were distributed from the anterolateral to posterior sectors, continuing posterolaterally (mid-section) into the posterolateral-posterior sector toward the apex. Adrenergic nerves were distributed across the anterolateral-posterior sectors at the base, with the course narrowing to the posterolateral-posterior sectors at the mid- and apical levels. Sensory fibres were found posterolaterally posteriorly at the base, continuing posterolaterally over the mid- and apical levels. Although it was not possible to determine the different nerve qualities, DTI confirmed histological findings from the base to the apex. CONCLUSIONS: Different types of nerve fibres were found to vary in distribution. When linked to possible functional aspects of the different nerve types, this morphological evidence may be of importance to further protect function after radical prostatectomy (RP). To our knowledge, this is the first time that DTI has confirmed reported histological findings in nerve-sparing RPs. DTI could be an important tool with which to correlate nerves to tumour for better preoperative planning and to incorporate imaging into treatment.