The value of T2– weighted MRI in the assessment of perisellar anatomy

U. Knappe; C. Jaursch-Hancke; U. Lörcher

doi:10.1055/s-2006-932939

Experimental and Clinical Endocrinology & Diabetes, Table of Contents

The value of T2– weighted MRI in the assessment of perisellar anatomy

U Knappe ¹, C Jaursch-Hancke ², U Lörcher ³

¹Dr. Horst Schmidt Klinik, Klinik für Neurochirurgie, Wiesbaden, Germany
²Deutsche Klinik für Diagnostik, Fachbereich Endokrinologie, Wiesbaden, Germany
³Deutsche Klinik für Diagnostik, Fachbereich Radiologie, Wiesbaden, Germany

Abstract

Objectice: To evaluate the anatomical relations of sellar and perisellar structures with T2– weighted MRI and to apply the MRI criteria of cavernosus sinus (CS) invasion by pituitary adenomas to normal sellar anatomy.

Methods: Thin slice (3mm) coronal T2– weighted MRI – images (1.5 T) obtained from 119 individuals with no known pituitary disorder (59 f, 60 m, mean age 48yrs, range 17 months to 87yrs) were analyzed (238 cavernous sinus). The relation of the pituitary gland and the horizontal part of the internal carotid artery (ICA) was assessed using the techniques of Knosp et al. (1993), Moreau et al. (1998) and Cottier et al.(2000).

Results: The medial wall of the CS was visible in 34%, the diaphragma sella in 53%, 14% showed a partial empty sella syndrome. The horizontal part of the ICA was located at the level of the sellar floor in 34%, below it in 47%, and above it in 19%. The mean distance between the ICA of both sides was 17.8mm (range 7 to 38mm), in 5 adults it was less than 10mm, in another 7 adults it exceeded 24mm. In 6 children younger than 7 years the mean distance was 15mm (range 12 to 24mm). In 58% of the cases the mean distance between the pituitary gland and the ICA was 2.8mm (range 1 to 7mm), in 42% the gland seemed to have contact to the ICA. Of these, in 67% the area of contact was the medial surface of the ICA, and in another 32% it was the medial and the upper aspect of the vessel. Only one case showed contact between the medial wall and the lower surface of the ICA. In this cases, assessment of the extent of contact by determining the angle which describes the amount of the vessel's circumference involved, revealed 1/12 in 18%, 2/12 in 40%, 3/12 in 30%, 4/12 in 10%, and 5/12 in 2% of the cases. The line drawn between the medial rim of the intra- and supracavernous ICA was crossed by the pituitary 9% of all cases, the intercarotid line in 5%.

Conclusion: The techniques used for assessment of pituitary tumors'invasiveness by MRI have to be estimated taking inter- and intraindividual variations into account.