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Uterine Arteriovenous Malformation (AVM) is a rare but potentially life-threatening vascular anomaly characterized by an abnormal direct connection between uterine arteries and veins without an intervening capillary bed.
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| Type | Description |
|---|---|
| Congenital AVM | Arises from embryologic failure of vascular development; involves multiple feeding arteries and draining veins |
| Acquired AVM | More common; develops after trauma to the uterine vasculature, often post-dilation & curettage (D&C), cesarean section, or uterine surgery |
| Modality | Imaging features |
|---|---|
| TVS | • Heterogeneous myometrial echotexture |
| • Anechoic tubular or cystic spaces within the myometrium |
Doppler study**:** • Mosaic flow pattern: Multidirectional, turbulent flow • High-velocity, low-resistance arterial waveforms • Pulsatile venous waveforms (arterialization of venous flow) | | MR | Indicated when US findings are equivocal • Flow voids in myometrium • Serpiginous signal voids on T1- and T2-weighted images • No discrete mass lesion | | CTA | Useful in acute settings or pre-embolization planning • May demonstrate early filling veins and multiple feeding arteries | | DSA | Gold standard for diagnosis and treatment • Tangle of vessels • Early venous drainage • Precise feeder vessels for embolization |
Images obtained of a 29-year-old woman with GTD coexisting with a uterine AVM after chemotherapy. (a) Colour Doppler imaging of the arteriovenous malformation within the myometrium showing brisk, highly expanded flow and pulsed Doppler imaging showing low-resistance, high-velocity flow. (b) Coronal T2-weighted MRI showing a mass located in the myometrium with an unclear boundary and heterogeneous signal (blue arrow). (c) Axial showing multiple vascular-like, irregular, serpentine flow void signs in the parametrium (blue arrow). (d) Coronal T2-weighted MRI showing multiple vascular-like, irregular flow void signs in the myometrium (blue arrow). (e,f) Pelvic angiogram of the left and right uterine arteries revealed simultaneous filling of the right draining veins in the early arterial phase, which is a definitive diagnostic finding of uterine AVMs.
Chen, Hz., Zhao, Fm., Liu, Lj. et al. Accuracy of flow-void diameters on MR images in diagnosing uterine arteriovenous malformations in patients with pregnancy-related diseases. Sci Rep 11, 19806 (2021). https://doi.org/10.1038/s41598-021-99209-9
| Condition | Distinguishing Features |
|---|---|
| ‣ | Endometrial mass with flow; hCG positive |
| ‣ | High β-hCG levels, mass with vascularity |
| Pseudoaneurysm | Focal anechoic area with “yin-yang” color Doppler sign |
| Uterine fibroid (with degeneration) | Mass effect, no turbulent intralesional flow |