Multidetector CT and cone‐beam CT have substantial agreement in detecting dental and sinus abnormalities in equine cadaver heads

Abstract

The performance of cone‐beam CT (CBCT) systems compared to conventional helical multidetector CT (MDCT) imaging of the equine head is unknown. The aim of this prospective, method‐comparison study was to compare the ability of CBCT and MDCT to detect abnormalities in equine cadaver heads. Eleven equine cadaver heads were scanned using a CBCT scanner and a 64‐slice MDCT scanner. Consensus evaluations for CBCT and MDCT scans were performed by three observers. Identified abnormalities were grouped into subcategories with a focus on dental abnormalities. Kappa agreement values between detected abnormalities for CBCT and MDCT methods were calculated. Of 468 teeth evaluated, 122 (26.1%) were found to have abnormalities (including in 58 infundibula and 7 pulps) using MDCT and 105 (22.4%) were found to have abnormalities (including in 52 infundibula and 2 pulps) using CBCT. The agreement between CBCT and MDCT was almost perfect for overall detection of dental abnormalities (k = 0.90) with k = 1 for diastema k = 0.95 for clinical crown abnormalities, and k = 0.93 for infundibular abnormalities. However, the detection of pulp changes by CBCT was only moderate k = 0.44. Increased scatter radiation, non‐calibrated Hounsfield Unit and artefacts in CBCT images made accurate identification of the pulp density difficult. In conclusion, CBCT results were similar to conventional MDCT for the majority of dental abnormalities, however, pulp abnormalities were not reliably identified using CBCT, potentially limiting its clinical use for detecting endodontic disease in its current form. Further comparison with more cases with confirmed dental disease and studies in clinical cases are warranted.

Use of a novel helical fan beam imaging system for computed tomography of the head and neck in sedated standing horses: 120 cases (2019–2020)

“…This can be clinically important in animals with endodontic abnormalities such as apical infections, and helical CT imaging may be more reliable in these cases. 3,6 With the growing use of standing CT imaging of horses, thorough evaluation of occupational exposure is needed for the Equina system and other types of standing CT imaging systems.…”

“…Primary dental disease, with or without secondary sinusitis, was the second most common clinical diagnosis (n = 23; Figure 2). Other clinical diagnoses were fractures (n = 10), periorbital tumor or abscess (7), temporohyoid osteoarthropathy (6), temporomandibular joint disease (6), sequestrum (5), primary sinusitis (5), nuchal bursitis (4; Figure 3), myositis ossificans or hematoma (4), dentigerous cyst (3; Figure 4), dental tumor (3), guttural pouch empyema (2), C2-C3 subluxation (1), parotid sialocele (1), choanal atresia (1), tumor in the cranium (1), and osseous mandibular cyst (1; Table 1). In 11 cases, no clinical diagnosis was made after examination and diagnostic imaging.…”

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C T has revolutionized equine clinical practice over recent decades, with CT imaging of the equine head currently considered preferable to conventional radiography. [1][2][3][4][5][6] Radiographic images of the head can be difficult to interpret because of the anatomic complexity of the osseous, soft tissue, and dental structures, and superimposition of head structures is an inherent problem when planar radiographic views are interpreted. Use of CT can also be advantageous for presurgical planning.

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“…with CT imaging in sedated standing horses. 2,3,17 Various types of cone-beam volumetric imaging and helical CT systems have been used in equine practice, 6,[12][13][14]18,19 and CT systems developed for imaging human patients have commonly been adapted for use in horses.…”

The Role of Computed Tomography in Imaging Non-neurologic Disorders of the Head in Equine Patients

“…The image quality is inferior to MDCT, especially for soft tissue structures ( 5 ); however, in one study assessing the agreement to detect abnormalities in equine cadaver heads, there was perfect agreement in detecting dental abnormalities including diastema, clinical crown and infundibular abnormalities but an only moderate agreement in identifying pulpar changes. Identification of pulpar changes on CBCT was unreliable due to the degree of scatter radiation, artifacts and the lack of Hounsfield calibration ( 11 ). The high exposure settings inherent to all types of computed tomography can pose a safety risk for personnel restraining sedated horses ( 5 ), especially if the handler remains next to the horse during the scan.…”