Magnetic resonance imaging (MRI) is steadily gaining importance in the investigation of female reproductive tract [10]. With excellent soft tissue contrast and no ionizing radiation, the introduction of gadolinium-based contrast agents into the uterine cavity, allows evaluation of the fallopian tubes [6, 7]. Fallopian tube pathologies are a common factor to female infertility. Either conventional HSG or laparoscopy combined with chromotubation is considered as the gold standard in the assessment of the patency of the fallopian tubes [12]. A disadvantage of conventional HSG is that this technique leads to a radiation dose to the reproductive organs of young potentially fertile women that may cumulate up to 440 ± 140 cGy/m2 [7]. Compounded with a limited evaluation of other causes of infertility, such as congenital uterine malformation, myometrial abnormalities (adenomyosis, leiomyomas) and extrauterine diseases (endometriosis, adhesions, pelvic infection, adnexal disease), convHSG leaves so much to be assessed [11]. This is where MR comes in. It can efficiently define uterine disease and anomalies with evaluation of endometrium as well as myometrium, with the advantage of identifying extrauterine causes of infertility. Moreover, tubal patency assessment is possible using a clinically available MR angiographic sequence (3D TRICKS). Several attempts have been made by different investigators to assess tubal patency in women using T1-weighted and T2-weighted sequences with a maximum temporal resolution of 20 s per phase, which resulted in adequately depicting tubal patency in most but not all patients [13]. In the current study, we used the 3D TRICKS MR angiographic sequence with dilute 1:100 gadodiamide and normal saline and successfully visualized contrast spill from fallopian tubes with laparoscopic chromotubation as the reference method (Figs. 2, 3, 4, 5, 6, 7).
Three-fourths of the patients in our study had primary infertility. The results were consistent with the study done by Sakar et al. [14] on conventional HSG, wherein the women with primary infertility outnumbered those with secondary infertility. Another study done by Winter et al. [12] also had primary infertility as the main indication for MRHSG.
The main focus of our study was evaluation of tubes with MRHSG. Fifty-four (85.7%) patients had bilateral Fallopian tubes patent. A total of 9 patients had tubal pathology (14.3%) out of which one had unilateral and eight had bilateral tubal obstruction. Sadowski et al. [11] found bilateral tubal patency in 75% patients and tubal pathology in 25% on MRHSG. The study done by Winter et al. [12] found bilateral tubal patency in 82% patients and tubal pathology in 18% on MRHSG. In our cohort, at MRHSG, 54 (85.71%) patients showed no tubal block, 1 (1.6%) showed one-sided tubal occlusion, and 8 (12.7%) showed two-sided tubal occlusion. In comparison, at laparoscopy 56 (88.8%) patients showed no tubal block, 2 (3.2%) showed one-sided tubal occlusion, and five (%) showed two-sided tubal occlusion. The sensitivity of MRHSG was 100% and specificity 71.4% when disease was defined as any form of tubal occlusion detected at laparoscopy, be it one-sided or two-sided, with positive and negative predictive values being 68.4 and 100%, respectively. Our study was consistent with the study done by A Kohan et al. [15] in terms of sensitivity which also showed 100% sensitivity of MRHSG for tubal patency evaluation. Sensitivity and specificity of MRHSG in our study were 62.5% and 72.0%, respectively, when the definition of disease was limited to double-sided tubal occlusion detected at laparoscopy, with positive and negative predictive value being 41.7% and 85.7%, respectively. Volondat et al. [16] found the diagnostic accuracy of MRHSG for ‘global’ analysis of tubal abnormalities (without distinguishing laterality or characteristic of abnormality) was 88.5% and that with laterality matching was 76.9%.
Our study on the diagnostic performance of MRHSG has shown high sensitivity and good specificity for tubal patency evaluation when compared to the true gold standard for tubal patency assessment, laparoscopic chromotubation. More patent tubes (n = 2) were diagnosed with laparoscopy than MRHSG which may be attributed to either higher tissue contrast or to a secondary outcome of the initial procedure, as also reported and hypothesized by Sadowski et al. [11].
Diagnostic accuracy of MRHSG compared to laparoscopy revealed 100% sensitivity and specificity for structural abnormality and endometrial cavity. The study done by A Kohan et al. [15] also showed 100% agreement between MRHSG and laparoscopy over uterine morphology and type of morphology.
The complications encountered were mild pelvic pain (3), dizziness (2) and bleeding per vagina (2). The bleeding was referred as spotting during the first 24 h that would spontaneously disappear after that lapse of time. Volondot et al. [16] in their study had 4 patients complaining of pain, two developed vagal symptoms, and one case of salpingitis after the procedure. We did not experience any case with vagal symptoms or infective complications in our study.
Besides having high sensitivity and specificity for uterine morphology and abnormalities, MRHSG also helped to detect and characterize myometrial and adnexal abnormalities. In our patient group, five had leiomyomas, two had adenomyosis, one had both leiomyoma and adenomyosis and one had septate uterus. A study done by Sadowski et al. [11] found the uterine contour abnormalities on MRI to be due to myometrial abnormality (leiomyoma) and congenital uterine malformation (arcuate and partial sepate). Another study done by Winter et al. [12] found comparable results and detected uterine abnormalities to be either due to myometrial lesions (leiomyomas) in three patients or congenital uterine malformation (arcuate uterus and partial septate uterus) in two patients. Ovarian abnormalities were detected in 18 patients, in whom 14 had polycystic ovarian morphology, three had endometriotic cyst and one had atrophic ovaries. Sadowski et al. [11] in a study found adnexal abnormalities including a hydrosalpinx, endometrioma and an atrophic ovary. Winter et al. [12] found adnexal abnormalities in 6 patients which include polycystic ovaries in 5 patients and hydrosalpinx in one patient.
Furthermore, most of the findings reported in MR-HSG correlated with those reported on diagnostic laparoscopy. Poor correlation between MR-HSG and surgery was only found in the case of peritoneal adherences, as flimsy adherences could not be detected by MR sequences, resulting in an underestimation of pelvic endometriosis.
The downsides in our study were small sample size and utilization 1.5 T MRI for evaluation in all the women selected. 3 T MRI is being installed nowadays although less frequently in government sector in resource-poor countries like India, thereby limiting the generalizability of the study results. Although expensive than combination of USG and conventional HSG, MRHSG may prove to be one-stop shop for the evaluation of female infertility especially in patients where both conventional HSG and standard MRI are necessary for the evaluation. Advances in MR sequences may eventually allow us to study the motility and mucosal surfaces of tubes in lieu of celioscopy.
