Emergency CT head and neck imaging: effects of swimmer's position on dose and image quality.

Eur Radiol

Institut für Klinische Radiologie, LMU Klinikum der Universität München - Innenstadt, Department of Clinical Radiology, LMU Hospital of the University of Munich - Downtown Campus, Nußbaumstr. 20, 80336, Munich, Germany,

Published: May 2014

Objectives: To compare the effects of different arm positions on dose exposure and image quality (IQ) in cervical spine CT after trauma in different patient groups.

Methods: Patients in standard (STD = 126) and in swimmer's position (SWIM = 254) were included. Body mass index (BMI subgroup 1 = underweight to subgroup 4 = obese), anterior-posterior diameter (AP), left-right diameter (LR), area of an ellipse (AoE) and angle between the humeral heads (optimal STD < 3°, optimal SWIM > 10°) were used as grouping criteria. Computed tomography dose index (CTDI) was documented. Two radiologists rated the IQ at three levels (CV1/2, CV4/5, CV7/T1) using a semi-quantitative scale (0 = not diagnostic, 1 = diagnostic with limitations, 2 = diagnostic without limitations). The Mann-Whitney U test correlations of grouping criteria with dose effects and intra-class correlation (ICC) were calculated.

Results: ICC was 0.87. BMI grouping showed the strongest correlation with dose effects: CTDI of optimal STD versus optimal SWIM positioning was 3.17 mGy versus 2.46 mGy (subgroup 1), 5.47 mGy versus 3.97 mGy (subgroup 2), 7.35 mGy versus 5.96 mGy (subgroup 3) and 8.71 mGy versus 8.18 mGy (subgroup 4). Mean IQ at CV7/T1 was 1.65 versus 1.23 (subgroup 1), 1.27 versus 1.46 (subgroup 2), 1.06 versus 1.46 (subgroup 3), 0.79 versus 1.5 (subgroup 4).

Conclusion: Patients with a BMI > 20 kg/m(2) benefited from both potential dose reduction and improved image quality at the critical cervicothoracic junction when swimmer's position was used.

Key Points: • BMI is a useful metric for personalized optimization in CT for the c-spine. • Using swimmer's position, patients can benefit from dose reduction. • In some patients a superior image quality can be achieved with swimmer's position. • For swimmer's positioning an angle of more than 10° is optimal.

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00330-014-3105-1DOI Listing

Publication Analysis

Top Keywords

swimmer's position
20
image quality
16
mgy versus
16
mgy subgroup
16
subgroup
10
versus
9
grouping criteria
8
dose effects
8
mgy
8
versus 146
8

Similar Publications

We aimed to investigate whether a linear relationship exists between swimming velocity and vertical body position for each stroke phase in front crawl, and to determine whether there are differences in the velocity effect among the stroke phases. Eleven male swimmers performed a 15 m front crawl at various swimming velocities. The whole-body centre of mass (CoM) was estimated from individual digital human models using inverse kinematics.

View Article and Find Full Text PDF

Mapping spatial patterns to energetic benefits in groups of flow-coupled swimmers.

Elife

December 2024

Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, United States.

The coordinated motion of animal groups through fluids is thought to reduce the cost of locomotion to individuals in the group. However, the connection between the spatial patterns observed in collectively moving animals and the energetic benefits at each position within the group remains unclear. To address this knowledge gap, we study the spontaneous emergence of cohesive formations in groups of fish, modeled as flapping foils, all heading in the same direction.

View Article and Find Full Text PDF

Context: Advancements in portable load-cell technology have enabled high-quality assessment of shoulder internal (IR) and external rotation (ER) peak force (Fmax) and rate of force development (RFD). This study's purpose was to explore the reliability and differences between IR and ER Fmax and RFD in different testing positions using a novel load-cell device.

Design: A within-subjects repeated-measures design was employed to compare the intersession values and reliability of Fmax and RFD for both shoulder IR and ER across 3 positions: seated-0°, supine-0° and supine-90°.

View Article and Find Full Text PDF

Objective This study aimed to compare the lumbar spine, pelvic alignment, and trunk muscle activity in healthy participants with and without shoulder flexion restriction in a streamlined posture. Methods The lumbar lordosis angle, pelvic anteversion angle, and trunk muscle activity were measured in 31 young, healthy men in the resting standing position. The streamlined (SL) posture and correlation analysis were performed.

View Article and Find Full Text PDF

Background: Prone positioning improves oxygenation in adults with acute respiratory distress syndrome (ARDS) and has been extensively applied in intensive care units (ICU) during the COVID-19 pandemic. Although some complications due to the manoeuvre are well known, brachial plexus injury after prone positioning is reported as a rare complication and the phenomenon could be either very rare or underestimated.

Aim: This study aimed to evaluate the effect of swimmer position during prone ventilation on the onset of brachial plexus injury in patients admitted to ICU for ARDS.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!