Correlation between three-dimensional rectosonography and magnetic resonance imaging in the diagnosis of rectosigmoid endometriosis: a preliminary study on the first fifty cases.
OBJECTIVE
Deep infiltrating endometriosis (DIE) raises a number of diagnostic and therapeutic problems. Magnetic resonance imaging (MRI), the reference technique in endometriosis, is questioned for posterior pelvic lesions, especially in rectosigmoid locations. In this study, we describe a new technique called three-dimensional rectosonography (3D-RSG), which combines standard transvaginal ultrasonography (TVUS), 3-dimensional (3D) ultrasonography and the use of water for rectal contrast. We also assess the correlation between 3D-RSG and MRI in the diagnosis of rectosigmoid endometriosis.


METHODS
This study included 50 consecutive women with symptoms suggestive of DIE. After colorectal enema, they underwent a gynecological examination and a 3D TVUS during which 120ml of water was injected in the rectosigmoid to improve the performance of the examination. All patients also underwent an MRI and surgery was offered to the patient if there was discordance between the two procedures.


RESULTS
Fifty women underwent 3D-RSG between May and November 2012. All procedures were well tolerated by patients. Two examinations (4%) were stopped for technical reasons. Nineteen rectosigmoid nodules were diagnosed in 18 women (36%). Eighteen of these nodules were also identified on MRI, and one (2%) nodule seen on MRI was not diagnosed by 3D-RSG. In 31 examinations (62%), neither technique identified an intestinal lesion. There was a concordance rate of 96% between the two techniques. Using MRI as the reference technique, 3D-RSG had a sensitivity of 0.95, a specificity of 0.97, a positive predictive values of 0.95, and a negative predictive value of 0.97. There was a 30.3 positive likelihood ratio and a 0.05 negative likelihood ratio.


CONCLUSIONS
3D-RSG seems an interesting new method for diagnosis of rectosigmoid endometriosis and is both feasible and well tolerated. 3D-RSG is highly concordant with MRI in this indication, although further studies are needed to confirm these primary results.
Obstetric and Gynecology Department, Croix-Rousse University Hospital of Lyon, France; Université Claude Bernard Lyon 1, France. Electronic address: caphilip@hotmail.fr.
Charles-André
CA
Philip
Obstetric and Gynecology Department, Croix-Rousse University Hospital of Lyon, France.
Christian
C
Bisch
Radiology Department, Croix-Rousse University Hospital of Lyon, 103, Grande rue de la Croix-Rousse, Lyon, 69004 France.
Agnés
A
Coulon
Obstetric and Gynecology Department, Croix-Rousse University Hospital of Lyon, France.
Pierre
P
de Saint-Hilaire
Obstetric and Gynecology Department, Croix-Rousse University Hospital of Lyon, France.
René-Charles
RC
Rudigoz
Obstetric and Gynecology Department, Croix-Rousse University Hospital of Lyon, France; Université Claude Bernard Lyon 1, France.
Gil
G
Dubernard
D000328:Adult; D004715:Endometriosis / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D012002:Rectal Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D012007:Rectum; D012680:Sensitivity and Specificity; D012810:Sigmoid Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography / Q000379:methods*
Deeply infiltrating endometriosis; Intestinal endometriosis; Preoperative assessment; Rectosonography; Transvaginal ultrasonography