Pelvic MRI: Is Endovaginal or Rectal Filling Needed?

Abstract

Magnetic resonance imaging is the optimal modality for pelvic imaging. It is based on T2-weighted magnetic resonance (MR) sequences allowing uterine and vaginal cavity assessment as well as rectal evaluation. Anatomical depiction of these structures may benefit from distension, and conditions either developing inside the lumen of cavities or coming from the outside may then be better delineated and localized. The need for distension, either rectal or vaginal, and the way to conduct it are matters of debate, depending on indication for which the MR examination is being conducted. In this review, we discuss advantages and potential drawbacks of this technique, based on literature and our experience, in the evaluation of various gynecological and rectal diseases.

Keywords: Endoluminal contrast; GI imaging; GU imaging; Magnetic resonace imaging; Pelvic organ prolapse.

Fig. 1. 30-year-old woman with clinical suspicion of endometriosis (dysmenorrhea).

T2-weighted MR sequences in sagittal plane with rectal opacification only (A), and after rectal and vaginal opacification (B). Endometriotic nodule revealing low signal intensity is more conspicuous after vaginal distension (arrow) (B) than before use of opacification. Vaginal lesions are ruled out. MR = magnetic resonance

Fig. 2. Pelvic MRI study in 27-year-old female with endometriosis that presents dyspareunia.

T2-weighted MR images with rectal and vaginal opacification in sagittal (A), coronal (B), and axial (C) planes. Thanks to vaginal distension, thin fibrous lesion in posterior vaginal fornix displaying low signal intensity on T2-weighted images (arrows) (A-C) and hemorrhagic microcyst displaying high signal intensity focus on fat-suppressed T1-weighted MR image (arrow) (D) are depicted. MRI = magnetic resonance imaging

Fig. 3. Pre-operative MR images in 37-year-old patient with known endometriosis and suffering from recurrent dyschesia.

Sagittal T2-weighted MR view with rectal opacification (A) revealing endometriotic nodule of anterior wall of rectum (*), surgically removed. MRI conducted after surgery using T2-weighted MR images after vaginal and rectal opacification in sagittal (B), axial (C), and coronal (D) planes demonstrates endometriotic nodule in lateral right vaginal fornix (arrows) (B-D). This lesion had not been detected on pre-operative MR imaging, probably because of absence of initial vaginal distension.

Fig. 4. Pre-operative pelvic MR study in 28-year-old female with endometriosis presenting pain radiating to back.

Sagittal T2-weighted MR image using vaginal and rectal opacification reveals thick lesion in posterior vaginal fornix and posterior cervix (arrow) (B). There is large nodular lesion infiltrating anterior rectal wall on axial T2-weighted MR image (arrow) (C), associated with Douglas cul-de-sac obliteration. Vaginal and rectal opacification clearly improve detection of these lesions compared to what was observed on MR image MRI study conducted without opacification (A).

Fig. 5. Sagittal T2-weighted MR images without and after vaginal opacification in two women (respectively 41-year-old and 47-year-old) with cervical carcinoma.

Relatively high signal-intensity tumor is observed in posterior cervix (arrow). Vaginal fornices appear to be invaded by mass in absence of vaginal distension (A). After vaginal opacification, borders of tumor are better observed, and no vaginal extension is depicted in second case (arrow) (B). Tumor′s boundaries are less conspicuous without opacification.

Fig. 6. 45-year-old female with cervical tumor undergoing pretherapeutic MRI.

Sagittal T2-weighted MR image reveals large cervical tumor (*). Vaginal opacification nicely delineates wellpreserved posterior vaginal wall (arrow).

Fig. 7. 67-year-old female with endometrial carcinoma (*).

Sagittal T2-weighted MR image reveals that vaginal opacification facilitates identification of absence of vaginal involvement (arrow) from mass related to endometrial carcinoma (*).

Fig. 8. Midsagittal T2-weighted MR image in 62-year-old patient with dyssynergic defecation.

Distension of rectum simulates rectocele as rectal gel has not been completely evacuated during maximal straining (arrow).

Fig. 9. 27-year-old woman suffering from infertility.

A. Coronal T2-weighted MR image with ultrasound gel vaginal opacification reveals septate vagina (arrow), outlined by high T2 signal intensity from ultrasound endovaginal gel. B, C. Axial T2-weighted MR images in same patient at different levels reveal complete septate uterus with septum displaying homogenous low signal T2 signal and extending from fundus to cervix (arrows).

Fig. 10. 25-year-old patient with story of recurrent spontaneous miscarriages.

A. Coronal T2-weighted MR image without opacification image reveals bicornuate uterus with significant fundal cleft (*). B. Coronal T2-weighted MR images obtained with endovaginal gel reveal incomplete vaginal septation (arrow), easily overlooked without opacification.

Fig. 11. 18-year-old female with Mayer-Rokitansky-Küster-Hauser syndrome.

Sagittal T2-weighted MR image reveals absence of uterus. Vagina is not observed (arrow) (A). After opacification, on sagittal (B) and coronal (C) T2-weighted MR image, gel is not observed inside vagina (hypoplasic vagina), but underlines labiae (arrows). Ovaries are normal.

Fig. 12. 49-year-old woman complaining of mass in lower part of vagina.

A. Vaginal abnormalities are observed in sagittal T2-weighted MR images without vaginal opacification, but are difficult to analyze (arrow). B. After vaginal opacification was conducted subsequently, three cysts of anterior vaginal wall became much more conspicuous (arrows).