EP26.04: MRI‐ultrasound fusion imaging for diagnosis of deep infiltrating endometriosis: a critical appraisal

The aim of our study is to perform the first measurements in patients suspected of DIE and to assess the value of this technique in daily practice. In a prospective study, patients with clinical suspicion of endometriosis were selected for this study. In all patients we attempted to assess 7 anatomical landmarks. These landmarks were marked as targets in the fusion software system on the MRI scan. These targets were located with ultrasound image. We then measured the distance between the landmark organ and the target shown by the software system (measurement 1). A second measurement depicts the distance between the landmark and the nearest calibration point (measurement 2). After every 5 minutes, the calibration image was assessed. The calibration inaccuracy was measured as a third type of measurement (measurement 3). We selected 20 patients with clinical suspicion of DIE who had undergone a MRI scan. Twelve patients had a MRI without any movement artefacts and did agree to participate in our study. Measurement 1: the average distance was 14.6 mm (range: 0-96 mm). Measurement 2: in 28 of the 36 attempts (77.8%), we could measure the distance from landmark organ to the nearest calibration point. The average distance was 35.7 mm (range 0-105 mm). Measurement 3: A perfect match was seen in 6 of 17 attempts (35.3%). There was a deviation in 11 of the 17 attempts (62.5%). The mean distance in this group was 7.6 mm (range: 0-23 mm). We correlated measurement 1 to measurement 2 using Spearman's correlation. Spearman's rho was 0.360. This correlation is significant (p=0.028). Fusion imaging for DIE is a feasible technique and initial results are promising. However, to achieve well-interpreted MIFU-images, more precise clinical conditions need to be met. Also, the software needs to be improved. The cost-effectiveness of adding MIFU for the diagnosis of DIE can be questioned.