This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sakuma, K Articles by Okano, T Search for Related Content PubMed PubMed Citation Articles by Sakuma, K Articles by Okano, T

Does decreased T1 signal intensity in the retrodiscal tissue of the temporomandibular joint reflect increased density of collagen fibres?

¹ Department of Radiology, Showa University School of Dentistry, Tokyo, Japan; ² Department of Oral Pathology, Showa University School of Dentistry, Tokyo, Japan

*Correspondence to: Tsukasa Sano, Department of Radiology, Showa University School of Dentistry, 2-1-1, Kitasenzoku, Ohta-ku, 145-8515, Tokyo, Japan; E-mail: tssano{at}senzoku.showa-u.ac.jp

Received 24 November 2002; revised 13 June 2003; accepted 26 June 2003

Objective: To evaluate whether decreased signal intensity on T₁ weighted MR images of the retrodiscal tissue of the temporomandibular joint (TMJ) reflects increased density of collagen fibres.

Methods: Corrected sagittal T₁ weighted MR images of six TMJs from six fresh cadavers (three males and three females; age range 76–87 years, mean 80.8 years) were obtained. Following MRI, slices of tissue samples were taken from the cadavers that exactly matched the planes of the MR image. These samples were fixed, decalcified and stained (haematoxylin–eosin stain, Elastica van Gieson's stain) for light microscopy. The samples were evaluated for density of collagen fibres according to Hall et al (1984) and for vascularity, arterial wall thickness, fat content and elastin. In these sagittal samples, the retrodiscal tissue was divided anteroposteriorly and vertically into six areas and each area was classified by histological parameters. The MR images were similarly divided into six areas. Areas with reduced signal intensity were classified as the low signal group and those with no reduced signals were classified as the control group.

Results: Collagen density assessed histologically differed between the low signal intensity group and the control group, and loose collage density on the histological samples was observed significantly more often in the low signal group (Fisher's exact test, P=0.03). There were no statistically significant differences in the other categories between the two groups.

Conclusion: The results suggest that reduced T1 signals of retrodiscal tissue do not necessarily reflect a dense distribution of collagen fibres.

Keywords: temporomandibular joint; magnetic resonance imaging; pathology