Direct sagittal CT scan: a new diagnostic approach for surgical neonates

Because of their small body size, neonates can be placed in the plane of the CT scanner gantry (aperture diameter 70 cm) instead of across it. This direct sagittal scanning technique allows accurate delineation of surgical lesions, particularly midline ones, unobtainable with conventional axial imaging. In addition, the sagittal image provides a perspective of anatomic arrangement more familiar to the surgeon than that provided by axial sections and therefore allows for easier interpretation. In imperforate anus, sagittal CT identifies the blind rectal end by the meconium tissue interphase and therefore avoids the pitfalls of invertogram, which depends on the bowel gas pattern for interpretation. With this new approach, we correctly classified six cases of imperforate anus into high types (3) and low types (3), visualized the associated fistula and had knowledge of the exact distance of the blind rectal end from the skin level preoperatively. In tracheoesophageal fistula (2), sagittal CT demonstrated the air-filled blind pouch and fistula to allow preoperative classification and assessment of the gap distance. In sacrococcygeal teratoma (3) and laryngeal cyst (1), its use allowed an accurate assessment of possible extension of the lesion into neighboring structures. Our experience with direct sagittal CT scan therefore suggests that this new and noninvasive technique is a useful adjunct in the management of a variety of common neonatal surgical problems.