High resolution magnetic resonance imaging of the anal sphincter using an internal coil.

Abstract

An internal receiver coil was used to obtain high resolution transverse and oblique coronal magnetic resonance images of the anal sphincter in five normal volunteers and five patients. The internal sphincter had a high signal intensity on T1 weighted, T2 weighted, and STIR sequences whereas the conjoined longitudinal muscle and external sphincter had a low signal intensity. The internal sphincter (but not the external sphincter) showed contrast enhancement after administration of intravenous gadopentetate dimeglumine. The oblique coronal plane was particularly useful for showing the thickness and the relations ofthe external sphincter. Sphincteric abscesses as well as muscle defects, hypertrophy, and atrophy were clearly shown. The coil was well tolerated by most subjects. It has considerable potential for improving the diagnosis of anorectal disease. (Gut 1995; 37: 284-287)

Endoluminal MR Imaging of the Rectum and Anus: Technique, Applications, and Pitfalls

“…This coil gives satisfactory results in the imaging of rectal diseases but is not designed for endoanal imaging. However, dedicated endoluminal coils for the rectum and anus have also been developed (1)(2)(3)(4)(5). Two types of coils are currently in use.…”

“…Two types of coils are currently in use. One is a cylindric saddle-geometry receiver coil, which ranges from 6 to 10 cm in length and from 7 to 12 mm in diameter (2,4,6,7). The coil is placed in a rigid, thin protective cover and immobilized with an external clamp.…”

Perianal Fistüllerde MR Görüntüleme

“…Endoanal sargılarla yapılan incelemede anatomik rezolüsyon daha yüksek olmakla birlikte [20], görüntü alanının sınırlı olması önemli bir dezavantajdır. Görüntü alanı dışındaki fistül uzanımı ve abselerin gözden kaçmasına neden olabilir [10].…”

Role of MRI Fistulography with Gadopentate Enhancement in Assessment of Complex Anal Fistulas and Improving Surgical Outcomes

“…MRI with body or external phased array pelvic receiver coils can be used to assess both simple and complex fistulas. The development of an endoanal receiver coil has allowed high resolution MRI of the anal sphincter complex with detailed delineation of various muscle layers [11].…”