Spinal Disorders: Fundamentals of Diagnosis and Treatment Part 83. Spinal disorders are among the most common medical conditions with significant impact on health related quality of life, use of health care resources and socio-economic costs. Spinal surgery is still one of the fastest growing areas in clinical medicine. | Malformations of the Spinal Cord Chapter 29 815 from 16-20 weeks. However spina bifida may be missed particularly in the L5-S2 region 24 44 . Magnetic Resonance Imaging Since its advent MRI has become the imaging modality of choice. While ultrasonography is an excellent screening procedure it requires considerable expertise to interpret whereas MRI is definitive. Prenatal MRI can also be used to characterize the Chiari II and other associated malformations 24 . Prenatal imaging studies help to predict neurological deficits. MRI is the modality of choice for prenatal imaging Postnatal Diagnostic Tests Imaging Studies For evaluation of the spinal cord malformations and tethered cord syndrome the most helpful diagnostic images are obtained by MRI which provides excellent details of anatomy and characterization of soft tissue anomalies 39 58 . Other imaging studies including standard radiographs and CT may also be helpful. Plain radiographs will show vertebral anomalies. A CT scan is particularly useful for the evaluation of bony anomalies and split cord malformations 34 39 . Magnetic Resonance Imaging The best demonstration of the entire craniospinal axis is made by MRI and should be performed after the birth whenever possible. The T1- and T2-weighted MR images in the sagittal and axial planes provide excellent demonstrations of the anatomopathological characterization of the components of the malformation . relationship between placode and nerve roots and other associated sequences Chiari II hydrocephalus hydromyelia 32 . Before the MRI era it had been assumed that after untethering there would be upward migration of the spinal cord which in fact does not occur in most cases 19 . Postoperative follow-up MRI almost always shows low-lying conus and should not be confused with a retethering 10 . The diagnosis of retethering and decision for untethering requires clinical judgment. Attempts to improve conventional MRI techniques including the use of prone positioning .
