Scintigraphic examination of the cartilages of the foot.
BACKGROUND
Radiographic examination of the cartilages of the foot is well documented; however, there is limited information about their scintigraphic assessment.


OBJECTIVE
To evaluate the scintigraphic appearance of the cartilages of the foot using subjective and quantitative image analysis and to correlate radiographic and scintigraphic findings.


OBJECTIVE
An ossified cartilage would have similar radiopharmaceutical uptake (RU) to the ipsilateral aspect of the distal phalanx; RU would extend throughout the length of the ossified cartilage; a separate centre of ossification (SCO) would be identified on a scintigraphic image; and fracture or trauma to an ossified cartilage would manifest as increased RU (IRU).


METHODS
Front feet (n = 223) of horses (n = 186) that had dorsopalmar radiographic views and dorsal scintigraphic images were included in the study. The cartilages of the foot were graded radiographically and scintigraphically. Quantitative evaluation of the scintigraphic images was carried out using region of interest (ROI) analysis. For statistical analysis RU ratios were used. Correlations between a radiographically detected SCO and focal RU and between IRU and radiographic abnormalities were assessed.


RESULTS
There was a good correlation and an excellent agreement between radiographic and scintigraphic grades. ROI analysis showed a proximal to distal increase in RU ratios within each cartilage of the foot. A radiographically identified SCO could be detected scintigraphically in 12/17 feet (70.6%). Thirty-eight feet had IRU in the region of a cartilage, 25 of which (65.8%) had corresponding radiographic abnormalities. Fracture of an ossified cartilage was associated with IRU in all horses.


CONCLUSIONS
Scintigraphy may give information about the potential clinical significance of ossification of the cartilages of the foot and associated lesions, therefore prompting further investigation by use of a uniaxial ipsilateral palmar nerve block and imaging, using either magnetic resonance imaging and/or computed tomography.
Nagy
A
A
Centre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK.
Dyson
S J
SJ
Murray
R M
RM
D000818:Animals; D002356:Cartilage / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D005534:Foot Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D005552:Forelimb; D006734:Horse Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D006736:Horses; D007794:Lameness, Animal / Q000000981:diagnostic imaging / Q000473:pathology; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D011379:Prognosis; D011859:Radiography; D011877:Radionuclide Imaging / Q000379:methods / Q000662:veterinary*; D012720:Severity of Illness Index