E1424. Complicated Cesarean Delivery: Using 3D Models to Visualize Placental Invasion and Leiomyomas
  1. Michelle Ho; Health Design Lab; Sidney Kimmel Medical College
  2. Miranda Sill; Health Design Lab; Sidney Kimmel Medical College
  3. Courtney Woodfield; Abington Hospital
  4. Philip Lim; Abington Hospital
Placenta accreta spectrum (PAS) disorders and leiomyomas are two conditions that can complicate pregnancy and cesarean delivery. Accurate magnetic resonance (MR) imaging can readily demonstrate the presence and location of leiomyomas and extent of abnormal placentation and is critical to patient management and can help guide decision making. [1, 2] Understanding a patient’s unique three-dimensional (3D) uterine and placenta anatomy relative to neighboring structures can be difficult for trainees, surgeons, and patients. Patient-specific 3D models can be designed and printed from MR imaging to allow for better visualization of uterine and placental pathology. [3]

Educational Goals / Teaching Points
To review the indications and protocols for MR imaging of PAS disorders and leiomyomas. Examples of pathologies and imaging signs will be provided. A summary of the 3D printing workflow including segmentation, example design features, selection of material, printing, and post-processing will be included. The exhibit will also include samples of clinical applications of patient-specific 3D models.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
When ultrasound is positive for PAS disorders, MR imaging can further specify location and extent of placental invasion. For MR imaging, key sequences include T2-weighted single shot fast spin echo (SSFSE), T2-weighted steady state free precession (SSFP), gradient echo T2 sequence, and gradient echo T1 in-phase and opposed phase. Imaging signs include intraplacental T2 dark bands, abnormal intraplacental vascularity, heterogeneous intraplacental signal, placental bulge, bladder tenting, and focal myometrial thinning. 3D models can be created using data from MR imaging and requires segmentation and validation to produce a 3D printing compatible file. Computer-aided design (CAD) software can be used to further process the file. Features such as plane cuts and connectors can enhance the interactivity of the model and allow a user to see pathology within the uterine cavity.

For PAS disorders and leiomyomas with complex anatomic relationships, patient-specific 3D models are valuable tools for surgical planning, trainee education, and patient education. Radiologists should be familiar with the MR imaging protocols, segmentation, and design processes to produce these models. Increased awareness of 3D printing within this patient population can encourage further research about the utility of models for patient education and surgical planning.