ABSTRACT
Tenosynovitis of the digital flexor tendon sheath (DFTS) is diagnosed using ultrasonography and contrast tenography. Nevertheless, making a precise preoperative diagnosis is challenging. This study aimed to determine and compare the sensitivity and specificity of low-field MRI and MRI tenography (MRIt) to detect artificially created soft-tissue lesions in the DFTS. In 21 DFTSs, 118 lesions were made tenoscopically in the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), manica flexoria (MF) and proximal scutum. MRI and MRI, following intrathecal gadolinium administration (MRIt), were performed. The sensitivity and specificity of MRI and MRIt were calculated and compared. Proximal scutum lesions were less frequently identified by MRI (Sensitivity 38%, specificity 96%) compared to MRIt (Sensitivity: 50%, p = 0.80; specificity: 96%, p = 1). This was similar for SDFT lesions (Sensitivity: 39% versus 54%, p = 0.72; specificity: 93% versus 96%, p = 1). MRI detected DDFT lesions (sensitivity 34%; specificity 100%) better than MRIt (sensitivity 32%, p = 0.77; specificity 98%, p = 1). This was similar for MF lesions (MRI sensitivity 61%; specificity 100% vs. MRIt sensitivity 50%, p = 0.68; specificity 96%, p = 1). Lesion size was significantly associated with MRI or MRIt diagnosis (p = 0.001). The intrathecal administration of gadolinium did not significantly improve the ability of low-field MRI to diagnose artificial DFTS tendon lesions. Small lesion length was a significant discriminating factor for lesion detection. MRI and MRIt specificity were high, thus being helpful in diagnosing an intact structure.
ABSTRACT
The objective of this study was to compare articular cartilage thickness observed in the different 2D and 3D sequences to the cartilage thickness of the equine stifle in cadavers to determine the accuracy of each sequence. The study was conducted as a blinded laboratory study using seven equine stifle specimens. The 2D (T2W TSE) and 3D (3D VIEW T2W HR, T2 3D mFFE, T1W VISTA SPAIR, 3D PDW SPAIR) 3-tesla MRI sequences of each stifle were obtained. Cartilage thickness was measured at 30 locations on MRI and on gross pathology. Thickness measurements were compared using a Bland-Altman plot and post hoc analysis tests. The 3D sequences were found to be generally more accurate than the 2D sequence (p < 0.001). The smallest difference to macroscopic measurements was observed in the 3D VIEW T2W HR and T1W VISTA SPAIR sequences with no statistical difference between each other. Knowing the accuracy of different sequences will improve the evaluation of equine cartilage and the early detection of cartilage pathologies. This would promote MRI as a noninvasive imaging modality for horses suffering from stifle lameness with no findings in conventional imaging methods. Furthermore, since 3D sequences seem to have better accuracy in depicting cartilage, they may replace 2D sequences, thereby shortening scanning times.
ABSTRACT
OBJECTIVE: To determine the diagnostic performance of computed tomographic arthrography (CTA) and 3 Tesla magnetic resonance imaging (MRI) for detecting artificial meniscal, meniscotibial ligament (MTL) lesions and cruciate ligament (CL) lesions in horses. STUDY DESIGN: Ex vivo controlled laboratory study. ANIMALS: Nineteen stifles from adult horses. METHODS: Stablike defects (n = 84) (16 mm long, 10 mm deep) were created in the menisci (n = 35), CLs (n = 24), and MTLs (n = 25) via arthroscopy prior to MRI and CTA (80 mL contrast at 85 mg/mL per joint). Two radiologists, unaware of the lesions, reached a consensus regarding the presence of lesions, based on 2 reviews of each study. Sensitivity and specificity of MRI and CTA were determined using arthroscopy as a reference and compared with McNemar's tests. RESULTS: The sensitivity and specificity of MRI (41% and 86% respectively) and CTA (32% and 90% respectively) did not differ (P = .65). The sensitivity (MRI: 24%-50%; CTA:19%-40%) and specificity (MRI: 75%-92%; CTA 75%-100%) of imaging modalities did not differ when detecting lesions of the menisci, MTLs, and CLs (P = .1-1.0). The highest sensitivities were achieved when MTLs were evaluated with MRI (50%) and CLs with both modalities (40%). CONCLUSIONS: The diagnostic performance of CTA was comparable with that of MRI, with a low to moderate sensitivity and high specificity. CLINICAL SIGNIFICANCE: Computed tomographic arthrography should be considered as an adjunct to diagnose CL injuries. This is important for equine clinicians, as the CL cannot be visualized adequately using basic imaging techniques preoperatively.
