Early Evaluation of an Ultra-Portable X-ray System for Tuberculosis Active Case Finding

X-ray screening is an important tool in tuberculosis (TB) prevention and care, but access has historically been restricted by its immobile nature. As recent advancements have improved the portability of modern X-ray systems, this study represents an early evaluation of the safety, image quality and yield of using an ultra-portable X-ray system for active case finding (ACF). We reported operational and radiological performance characteristics and compared image quality between the ultra-portable and two reference systems. Image quality was rated by three human readers and by an artificial intelligence (AI) software. We deployed the ultra-portable X-ray alongside the reference system for community-based ACF and described TB care cascades for each system. The ultra-portable system operated within advertised specifications and radiologic tolerances, except on X-ray capture capacity, which was 58% lower than the reported maximum of 100 exposures per charge. The mean image quality rating from radiologists for the ultra-portable system was significantly lower than the reference (3.71 vs. 3.99, p < 0.001). However, we detected no significant differences in TB abnormality scores using the AI software (p = 0.571), nor in any of the steps along the TB care cascade during our ACF campaign. Despite some shortcomings, ultra-portable X-ray systems have significant potential to improve case detection and equitable access to high-quality TB care.

COMPARATIVE STUDY OF THE DIFFERENT VERSIONS OF THE GENERAL IMAGE QUALITY EQUATION

<p><strong>Abstract.</strong> The General Image Quality Equation (GIQE) is an analytical tool derived by regression modelling that is routinely employed to gauge the interpretability of raw and processed images, computing the most popular quantitative metric to evaluate image quality; the National Image Interpretability Rating Scale (NIIRS). There are three known versions of this equation; GIQE&amp;nbsp;3, GIQE&amp;nbsp;4 and GIQE&amp;nbsp;5, but the last one is scarcely known. The variety of versions, their subtleties, discontinuities and incongruences, generate confusion and problems among users. The first objective of this paper is to identify typical sources of confusion in the use of the GIQE, suggesting novel solutions to the main problems found in its application and presenting the derivation of a continuous form of GIQE&amp;nbsp;4, denominated GIQE&amp;nbsp;4C, that provides better correlation with GIQE&amp;nbsp;3 and GIQE&amp;nbsp;5. The second objective of this paper is to compare the predictions of GIQE&amp;nbsp;4C and GIQE&amp;nbsp;5, regarding the maximum image quality rating that can be achieved by image processing techniques. It is concluded that the transition from GIQE&amp;nbsp;4 to GIQE&amp;nbsp;5 is a major paradigm shift in image quality metrics, because it reduces the benefit of image processing techniques and enhances the importance of the raw image and its signal to noise ratio.</p>

Technical note: Influence of feed on image quality of abdominal ultrasonography in New Zealand white kits

<p class="Body">The aim of this study was to evaluate the influence of feed change on image quality of ultrasound scanning of the gallbladder, kidney and jejunum in New Zealand White kits. Thirty-nine 35-day-old rabbits were used, distributed into 4 diet groups: C, only commercial feed; CH, commercial feed and hay; C24H, only commercial feed, replaced by hay 24 h before examination; and CH24H, commercial feed and hay, with the commercial feed withdrawn 24 h before the exam. The rabbits received the diet for 42 d (from 35 to 77 d of age) and the ultrasound evaluations were performed on days 56 and 77. Ultrasonographic assessment for image quality focused on the possibility of visualisation and an image quality rating (3 scores: unacceptable, acceptable or excellent) for the gallbladder, kidneys and jejunum. The kidneys were visualised in 100% of animals of all diets and ages. There was no difference in visualisation (P&gt;0.05) of the gallbladder among the animals fed different diets on days 56 and 77. The C24H diet had a higher visualisation possibility (P&lt;0.05) of the jejunum compared to the C and CH diets on day 77. For the image quality score, there was no difference in the studied organs on day 56. However, on day 77, there was a difference for the jejunum (P&lt;0.05), and only the C24H and CH24H diets presented images classified as excellent. In conclusion, the image quality of the kidneys and gallbladder was unaffected by feed, and the jejunum had an improved image quality with the inclusion of hay and without the commercial feed 24 h before the test in New Zealand White rabbits at 77 d of age.</p>

Double Bolus Application in TWIST-MR-Angiography of the Cervical Arteries

Purpose. The aim of the present work was to test the feasibility of the time-resolved MR-angiography (TWIST-MRA) of cervical arteries using double bolus injection.Material and Methods. TWIST-MRA with a temporal resolution of 8.4 seconds for each frame and a spatial resolution with a voxel size of was performed in 24 patients. A biphasic bolus injection protocol was used with the second injection being started 21 seconds after the first contrast dye bolus. Diagnostic image quality was rated according to a 4-point scale.Results. In 12 patients (50%) no clear separation between the cervical venous and arterial vessels was evident after the first bolus injection. Using TWIST-MRA data acquired after the second bolus a sufficient diagnostic image quality (rating , mean 3.5) could be obtained in 22 of 24 patients (92%).Discussion. The double bolus injection protocol using TWIST-MRA allows for very good separation of the cervical arteries.