2D-3D Ultrasound in the Diagnosis of Uterine Malformations

Abstract

Uterine malformations form a non-homogenous group of pathologies with a variable impact on reproduction, often not strictly related to the apparent seriousness of pathology. It concerns about 1-5% of women. Among the many tecniques, invasive and not, useful to diagnosis, many authors believe that laparoscopy associated with hysteroscopy allows diagnosis in all cases. Many references confirm this opinion: hysteroscopy and laparoscopy are used in the classification of uterine anomalies. Magnetic resonance imaging, safe and little invasive, gives a diagnostic accuracy close to 100%. From 1997 to nowadays magnetic resonance has demonstrated its role in the imaging of female pelvis. Pellerito et al using magnetic resonance correctly diagnosed 24 of 24 anomalies (100% accuracy), compared to 11 of 12 anomalies (92%) using endovaginal sonography. Magnetic resonance imaging demonstrated 100% sensitivity and specificity compared to 67% sensitivity and 100% specificity of transvaginal sonography for unicornuate or bicornuate uteri (anomalies requiring surgery). For non-surgical uterine anomalies, both techniques had 100% sensitivity and specificity. Pellerito et al also noted that magnetic resonance imaging had the further advantage of detecting other incidental abnormalities, including a dermoid and submucosal leiomyoma, not found on transvaginal ultrasound (indeterminate and nonvisualized). A review by Troiano et al confirms that the need for diagnostical surgical intervention has largely been eclipsed with the advent of magnetic resonance imaging, which has become the imaging modality of choice for characterization of congenital mullerian anomalies. Ultrasound imaging, in its various techniques available, gives 92% or more of diagnostic accuracy, with some advantages, like lower costs, availability of equipments, non invasivity, repeatability, use at an early stage of pregnancy. The traditional 2D ultrasound gives a good visualization of the uterine outline and a good endometrial image as well. The main difficulty is obtaining especially in “non-ideal” patients, all the correct sections, which is absolutely necessary to identify malformations, especially the coronal section. These limits of the bidimensional scanning were noted from 1987 in a study by Nicolini et al. The authors founds that transabdominal 2D sonography failed to visualize the uterine cavity adequately in as many as 35% of patients although it adequately imaged the uterine fundus in 90% of patients. For reasons not been elucidated, patients with uterine malformations often have preterm birth. Transvaginal ultrasound examination is an accurate test for the prediction of preterm birth. A study by Airoldi et al, examined specifically preterm birth in this population, evaluating 64 pregnancies : there were 28 with a bicornuate uterus, 13 with a septate uterus, 11 with a uterine didelphys, and 12 with a unicornuate uterus. They were followed prospectively. In women with uterine anomalies, if transvaginal scan shows a short cervical length , exists a 13fold risk for preterm birth. Unicornuate uterus had the highest rate of cervical shortening and preterm delivery (level of Evidence: II-2) (Figs 1 to 3). Sonohysterography provides further information on the endometrial cavity. In a study by Sergeant et al, 14 patients with a history of repeated spontaneous abortion or infertility, after the hysterosalpingography were examined by hysterosonography. The uterine septum were diagnosed by hysterosonography in all 14 patients (100%). A recent study that evaluates the role of saline infusion sonohysterography in the investigation of uterine abnormalities and malformations in Donald School Journal of Ultr Obstetrics and Gynecology, July-Sept. 2007;1(3):77-79