Incidental finding during pelvic ultrasound examination. Evaluation performed using B-mode imaging and 3D ultrasound with CMPR and 4D shading for uterine morphology assessment.
B-mode ultrasound demonstrated a normal-sized uterus with no focal myometrial lesions. Subsequent 3D acquisition allowed multiplanar reconstruction (CMPR), providing a coronal view of the uterine cavity. Optimization of CMPR quality and application of 4D shading enhanced the contrast between the endometrium and surrounding myometrium.
These adjustments enabled accurate delineation of the endometrial cavity contour. A shallow indentation at the fundal region was identified, with preserved external uterine contour. Precise measurement of the indentation depth and angle confirmed a mild concavity consistent with an arcuate configuration. The improved visualization was essential to differentiate this variant from other Müllerian anomalies.
Final diagnosis:
Arcuate uterus.
Differential diagnosis:
Septate uterus (partial), subseptate uterus, normal uterine variant.
Teaching points:
Accurate assessment of uterine anomalies requires a coronal plane view, best obtained with 3D ultrasound and CMPR. Image optimization techniques such as 4D shading significantly improve endometrial-myometrial contrast, enabling precise measurement of fundal indentation depth and angle.
Injury/disease information:
An arcuate uterus is considered a mild Müllerian duct variant characterized by a small fundal indentation into the endometrial cavity. It is generally regarded as a normal anatomical variant with minimal or no clinical impact on fertility or pregnancy outcomes.
