Multi–Detector Row CT for Depicting Anatomic Features of Cephalothoracopagus Varieties: Revised Approach
Movie 1. Deradelphous diprosopous cephalothoracopagus twins. (Movie 1a) Three-dimensional view obtained with volume-rendering technique with automatic rotation of 360° around the vertical axis shows the entire body surface. (Movie 1b) Dynamic scan obtained with volume-rendering technique with different, optimized pixel values, gain, and opacity demonstrates the skin and osseous structures of the conjoined twins. Structures of the splanchnocranium show an incomplete division at the midline, resulting in three eyes (one eye is shared) and two nasal and oral cavities. At the bottom of the central, shared ocular cavity, two separate optical foramina for the ocular nerves can be traced. (Movie 1c) Dynamic view through the coronal planes obtained with volume-rendering technique gives another perspective of the external and internal body structures. The inferior part of the occipital bone is severely deformed and shows two great foramina. The two vertebral columns are completely independent and diverge inferiorly. The arms and legs of the twins are well formed and independent.
This view does not allow distinction of visceral structures, owing to the prolonged fixation time of the specimen.
Movie 2. Deradelphous cephalothoracopagus twins. (Movie 2a) Three-dimensional view obtained with volume-rendering technique with automatic rotation of 360° around the vertical axis shows the entire body surface.
(Movie 2b) Dynamic scan obtained with volume-rendering technique with different, optimized pixel values, gain, and opacity depicts well-shaped ocular cavities. The nasal cavities show an initial attempt at duplication; the nasal septum is duplicated, but there is a shared middle nasal cavity. The oral cavities are also complex and deformed because of the presence of a septum. (Movie 2c) Dynamic view through the coronal planes obtained with volume-rendering technique gives another perspective of the ocular, nasal, and oral cavities and the remaining skeletal and skin structures.
Movie 3. Iniop cephalothoracopagus twins. (Movie 3a) Three-dimensional view obtained with volume-rendering technique with automatic rotation of 360° around the vertical axis shows the entire body surface.
(Movie 3b) Dynamic view through the coronal planes obtained with volume-rendering technique with different, optimized pixel values, gain, and opacity depicts the "concentration of facial structures" phenomenon and the surface of some thoracic and abdominal structures (eg, heart, thoracic aorta, diaphragm, liver, peritoneal folds, bowel loops).
Movie 4. Iniop cephalothoracopagus twins. (Movie 4a) Three-dimensional view obtained with volume-rendering technique with automatic rotation of 360° around the vertical axis shows the entire body surface. Note that the single head shows a composite face on one side, while on the other side, the face is hypotrophic, consisting of two ears only.
(Movie 4b) Dynamic scan obtained with volume-rendering technique with different, optimized pixel values, gain, and opacity depicts the skin and osseous structures of the conjoined twins. In particular, this view offers a good depiction of the single empty ocular cavity (ciclopy) on the hypotrophic side. (Movie 4c) Dynamic view through the coronal planes obtained with volume-rendering technique offers a good depiction of the neurocranium with its well-shaped ocular, nasal, and oral cavities.
Movie 5. Symmetric cephalothoracopagus (janiceps) twins. (Movie 5a) Three-dimensional view obtained with volume-rendering technique with automatic rotation of 360° around the vertical axis shows the entire body surface. Note that each face is well shaped but is shared by the twins and is therefore a composite structure belonging half to one twin and half to the other.
(Movie 5b) Dynamic scan obtained with volume-rendering technique with different, optimized pixel values, gain, and opacity depicts the skin and osseous structures of the conjoined twins. In addition, this view shows that the sphenoidal bone represents the center of mass of the single head and is a deformed structure shared by the twins. (Movie 5c) Dynamic view through the coronal planes obtained with volume-rendering technique shows a single sella turcica communicating with the pharyngeal cavity. The two occipital bones are independent and inferiorly articulate with two completely independent vertebral columns that diverge inferiorly. Note that the arms and the legs of the twins are well formed and independent.
