Applicability of three-dimensional imaging techniques in fetal medicine.
OBJECTIVE
To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology.


METHODS
We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques.


RESULTS
Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations.


CONCLUSIONS
The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models.
PhD, MD, Radiologist at the Alta Excelência Diagnóstica and at the Clínica de Diagnóstico Por Imagem (CDPI), Rio de Janeiro, RJ, Brazil.
Heron
H
Werner Júnior
PhD, Technologist at the Instituto Nacional de Tecnologia, Rio de Janeiro, RJ, Designer at the Center for Three-Dimensional Experimentation of the Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ, Brazil.
Jorge Lopes
JL
Dos Santos
Biologist at the Center for Three-Dimensional Experimentation of the Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ, Brazil.
Simone
S
Belmonte
Designer at the Center for Three-Dimensional Experimentation of the Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ, Brazil.
Gerson
G
Ribeiro
PhD, MD, Radiologist at the Alta Excelência Diagnóstica and at the Clínica de Diagnóstico Por Imagem (CDPI), Rio de Janeiro, RJ, Brazil.
Pedro
P
Daltro
PhD, MD, Radiologist at the Clínica de Diagnóstico Por Imagem (CDPI), Rio de Janeiro, RJ, Brazil.
Emerson Leandro
EL
Gasparetto
PhD, Full Professor of Radiology at the Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
Edson
E
Marchiori
Computed tomography; Fetal medicine; Fetus; Magnetic resonance imaging; Three-dimensional technique; Ultrasound