Effect of Additional Aluminum Filtration on the Image Quality in Cone Beam Computed Tomographic Studies of Equine Distal Limbs Using Visual Grading Characteristics Analysis: A Pilot Study.
Abstract: (1) Background: Cone beam computed tomography (CBCT) is increasingly used in equine practice to diagnose musculoskeletal injuries, including fractures in the distal limb. However, limited detail in the thick cortical bone of the metacarpus/metatarsus hinders accurate diagnosis. In human medicine, the addition of aluminum filters (AF) enhanced image quality while reducing radiation exposure. This study aimed to evaluate the effect of AF on image quality in CBCT scans of equine distal limbs. (2) Methods: Adult equine cadaver limbs were scanned with a mobile CBCT unit using varying tube currents (10-100 mA) and AF (13-25 mm). Two independent experts assessed the image quality using a four-point visual grading scale, focusing on cortical bone detail and artifacts. (3) Results: Higher tube currents generally improved image quality, but no filter was beneficial for the metacarpal/metatarsal regions. For the proximal phalanx, thicker AF (19-25 mm) improved image quality without significantly increasing the required tube current. (4) Conclusions: The optimal balance between image quality and radiation exposure using the O-arm CBCT system for equine distal limbs was a tube current of 50 or 64 mA without filtration for the metacarpus/metatarsus, while a tube current of 50 mA with a 19-25 mm AF provided the best image quality for the proximal phalanx.
Publication Date: 2025-11-02 PubMed ID: 41295689PubMed Central: PMC12656789DOI: 10.3390/vetsci12111051Google Scholar: Lookup
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Summary
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Research Overview
- This study investigated how adding aluminum filters affects image quality in cone beam computed tomography (CBCT) scans of horse lower limbs, aiming to improve diagnostic detail while managing radiation levels.
Background
- CBCT is a growing diagnostic tool in equine medicine, especially for examining bone injuries in the distal limbs (lower leg areas).
- The thick cortical bone in horse metacarpus and metatarsus bones creates challenges for clear imaging, limiting accurate diagnosis of fractures or injuries.
- In human medical imaging, adding aluminum filters to the X-ray beam has been shown to improve image quality and reduce radiation dose.
- The study aimed to test if similar benefits from aluminum filtration occur in equine CBCT imaging, specifically for distal limbs.
Methods
- The study used adult horse cadaver limbs to ethically test imaging protocols without exposing live animals to radiation.
- A mobile CBCT unit was employed to scan the limbs with varying settings:
- Tube currents ranged from 10 to 100 mA (adjusting the X-ray intensity).
- Aluminum filter thicknesses tested ranged from 13 mm to 25 mm.
- Two independent expert reviewers assessed image quality focusing on:
- Detail visibility in cortical bone areas.
- Presence and severity of artifacts (image distortions).
- Image quality was scored using a standardized four-point visual grading scale.
Results
- Higher tube currents generally led to better image quality, reflecting improved image clarity with increased X-ray intensity.
- For the metacarpal and metatarsal bones, adding aluminum filters did not enhance image quality, suggesting filtration was not beneficial in these thick bone regions.
- For the proximal phalanx (a bone closer to the hoof), using thicker aluminum filters (19-25 mm) improved image quality significantly, without requiring a substantial increase in tube current.
Conclusions
- Optimal imaging settings differ by bone region within the equine distal limb:
- For metacarpus and metatarsus bones, the best balance was achieved at 50 or 64 mA tube current without any aluminum filter.
- For the proximal phalanx, using a 19-25 mm aluminum filter with 50 mA tube current provided the highest image quality.
- The findings suggest that tailored use of aluminum filters can improve diagnostic imaging specifically in certain bones of the horse’s distal limb while controlling radiation exposure.
- This pilot study lays groundwork for refining equine CBCT protocols and highlights the need to customize imaging parameters based on anatomical location.
Cite This Article
APA
Papini L, de Preux M, Pauwels F, Missotten J, Van der Vekens E.
(2025).
Effect of Additional Aluminum Filtration on the Image Quality in Cone Beam Computed Tomographic Studies of Equine Distal Limbs Using Visual Grading Characteristics Analysis: A Pilot Study.
Vet Sci, 12(11), 1051.
https://doi.org/10.3390/vetsci12111051 Publication
Researcher Affiliations
- Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Science, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland.
- Swiss Institute of Equine Medicine (ISME), Department of Clinical Veterinary Science, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland.
- Plexus Veterinary Imaging, 39A Lloyd George Road Wainui, Gisborne 4010, New Zealand.
- Institute of Virology and Immunology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland.
- Institute of Virology and Immunology, 3147 Mittelhäusern, Switzerland.
- Division of Clinical Radiology, Department of Clinical Veterinary Science, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland.
Conflict of Interest Statement
No external companies had any role in the writing of, or in the decision to publish, the research presented. All the research was performed by the authors independently. Authors Luca Papini, Mathieu de Preux, Joris Missotten, and Elke Van der Vekens were employed by the University of Bern. The remaining authors declare that this research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The sponsors had no role in the design, execution, interpretation, or writing of this study.
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