Meniscal tears: comparison of the conventional spin-echo and fast spin-echo techniques through image processing

Ibevan A Nogueira,Alessandro P Silva,Heverton C De Oliveira,Annie F Frère

doi:10.1186/1475-925x-13-33

Abstract

BackgroundConventional spin-echo (PD-CSE) and fast spin-echo (PD-FSE) techniques are frequently used to detect meniscal tears. However, the time delay for imaging with PD-CSE has resulted in its replacement with faster techniques, such as proton density fast spin-echo (PD-FSE), which has become a frequent tool at most diagnostic centres.Qualitative analysis shows that the PD-CSE technique is more sensitive, but other authors have not found significant differences between the aforementioned techniques. Therefore, we performed a quantitative analysis in this study that aims to measure differences in the quality of the images obtained with both techniques.MethodsWe compared the PD-CSE and PD-FSE techniques by quantitatively analysing the obtained proton density images: the area shown, as well as the brightness and lesion contrast of the obtained image.A set of 100 images from 50 patients thought to contain meniscal tears of the knee were selected. These 100 images were obtained from all individuals using both the PD-CSE and PD-FSE techniques. The images were processed using software developed in Delphi. In addition to these quantifications, three physicians, who are specialists in radiology and capable of analysing magnetic resonance (MR) images of the musculoskeletal system, qualitatively analysed the diagnostic sensitivity of both techniques.ResultsOn average, samples obtained via the PD-CSE technique contained 22% more pixels in the lesion area. The contrast differed by 28%, and the brightness differed by 31%. The two techniques were correlated using Student’s t-test, which showed a statistically significant difference. The specialists detected meniscal tears in 30 of the images obtained via the PD-CSE technique, while only 72% of these cases were detected via the PD-FSE technique.ConclusionsThe PD-CSE technique was shown to be superior to PD-FSE for all of the evaluated properties, making its selection preferable.

Highlights

Conventional spin-echo (PD-CSE) and fast spin-echo (PD-FSE) techniques are frequently used to detect meniscal tears
The three evaluators found the same 30 images to certainly show meniscal tears for images obtained via the proton density conventional spin-echo (PD-CSE) technique
The evaluators detected lesions in only and of the 30 corresponding images obtained via proton density fast spin-echo (PD-FSE)

Summary

Introduction

Conventional spin-echo (PD-CSE) and fast spin-echo (PD-FSE) techniques are frequently used to detect meniscal tears. MR images are peculiar during both the initial and later phases of meniscal tears because they show high resolution and excellent contrast between soft tissue structures. These images allow for rapid and precise diagnoses and decrease the need for the arthroscopic procedures that were historically used as the gold standard. The best diagnostic images were obtained using the proton density conventional spin-echo (PD-CSE) technique with fat saturation This method was a pioneering technique for detecting meniscal tears and was considered to be a viable alternative to arthroscopy [3]. Other researchers [6] have not found significant differences between the two techniques and reported that PD-CSE provided only a small improvement in image quality These studies were based on qualitative analyses. Three physicians who have specialised in radiology with experience in magnetic resonance (MR) imaging of the musculoskeletal system qualitatively analysed the diagnostic sensitivity of both techniques

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