Three-Dimensional Volume-Rendered Series Complements 2D Orthogonal Multidetector Computed Tomography in the Evaluation of Abnormal Spinal Curvature in Patients at a Major Cancer Center: A Retrospective Review
Background. Abnormal spinal curvature is routinely assessed with plain radiographs, MDCT, and MRI. MDCT can provide two-dimensional (2-D) orthogonal as well as reconstructed three-dimensional volume-rendered (3-D VR) images of the spine, including the translucent display: a computer-generated image set that enables the visualization of surgical instrumentation through bony structures. We hypothesized that the 3-D VR series provides additional information beyond that of 2-D orthogonal MDCT in the evaluation of abnormal spinal curvature in patients evaluated at a major cancer center. Methods. The 3-D VR series, including the translucent display, was compared to 2-D orthogonal MDCT studies in patients with an abnormal spinal curvature greater than 25 degrees and scored as being not helpful (0) or helpful (1) in 3 categories: spinal curvature; bony definition; additional findings (mass lesions, fractures, and instrumentation). Results. In 38 of 48 (79.2%) patients assessed, the 3-D VR series were scored as helpful in 63 of 144 (43.8%) total possible categories (32 spinal curvature; 14 bony definition; 17 additional findings). Conclusion. Three-dimensional MDCT images, including the translucent display, are complementary to multiplanar 2-D orthogonal MCDT in the evaluation of abnormal spinal curvature in patients treated at a major cancer center. 1. Background Abnormal spinal curvature may be idiopathic or secondary to dystrophic etiologies, such as congenital, traumatic, and malignant causes. Initial assessment and followup of patients with an abnormal spinal curvature have routinely been performed using plain radiographs [1]. To evaluate dystrophic features, magnetic resonance imaging (MRI) has also been utilized [2, 3]. Computed tomography (CT) is proving to be of benefit in the assessment of patients with an abnormal spinal curvature [4–10]. Recent advances in multidetector CT (MDCT) technique allow the evaluation of the spine in multiple 2-D planes (Figures 1(a) and 2(a)) and with a three-dimensional volume-rendered series (3-D VR) (Figures 1(b) and 2(b)). In addition, the data from the MDCT study can also be used to generate a translucent display, a computer-generated image set that provides 3-D images of the spine enabling assessment of surgical instrumentation through the bony structures (Figures 2(c) and 2(d)). The 3-D VR series, including the translucent display, which are generated by computer manipulation of the axial CT source data without additional radiation, have led to a growth in demand for MDCT for the imaging of the spine by the spine
References
[1]
R. M. Slone, M. MacMillan, and W. J. Montgomery, “Spinal fixation. Part 3. Complications of spinal instrumentation.,” Radiographics, vol. 13, no. 4, pp. 797–816, 1993.
[2]
A. I. Tsirikos, M. Ramachandran, J. Lee, and A. Saifuddin, “Assessment of vertebral scalloping in neurofibromatosis type 1 with plain radiography and MRI,” Clinical Radiology, vol. 59, no. 11, pp. 1009–1017, 2004.
[3]
M. Cardoso and R. F. Keating, “Neurosurgical management of spinal dysraphism and neurogenic scoliosis,” Spine, vol. 34, no. 17, pp. 1775–1782, 2009.
[4]
C. J. Adam, M. T. Izatt, J. R. Harvey, and G. N. Askin, “Variability in Cobb angle measurements using reformatted computerized tomography scans,” Spine, vol. 30, no. 14, pp. 1664–1669, 2005.
[5]
J. Street, B. Lenehan, J. Albietz, P. Bishop, M. Dvorak, and C. Fisher, “Intraobserver and interobserver reliabilty of measures of kyphosis in thoracolumbar fractures,” Spine Journal, vol. 9, no. 6, pp. 464–469, 2009.
[6]
S. G？？en, H. Havit？io？lu, and E. Alici, “A new method to measure vertebral rotation from CT scans,” European Spine Journal, vol. 8, no. 4, pp. 261–265, 1999.
[7]
M. Krismer, W. Sterzinger, C. Haid, B. Frischhut, and R. Bauer, “Axial rotation measurement of scoliotic vertebrae by means of computed tomography scans,” Spine, vol. 21, no. 5, pp. 576–581, 1996.
[8]
M. Kamimura, T. Kinoshita, H. Itoh et al., “Preoperative CT examination for accurate and safe anterior spinal instrumentation surgery with endoscopic approach,” Journal of Spinal Disorders, vol. 15, no. 1, pp. 47–51, 2002.
[9]
R. M. Slone, K. W. McEnery, K. H. Bridwell, and W. J. Montgomery, “Principles and imaging of spinal instrumentation,” Radiologic Clinics of North America, vol. 33, no. 2, pp. 189–211, 1995.
[10]
H. Kim, H. S. Kim, E. S. Moon et al., “Scoliosis imaging: what radiologists should know,” Radiographics, vol. 30, no. 7, pp. 1823–1842, 2010.
[11]
P. O. Newton, G. W. Hahn, K. B. Fricka, and D. R. Wenger, “Utility of three-dimensional and multiplanar reformatted computed tomography for evaluation of pediatric congenital spine abnormalities,” Spine, vol. 27, no. 8, pp. 844–850, 2002.
[12]
D. J. Hedequist and J. B. Emans, “The correlation of preoperative three-dimensional computed tomography reconstructions with operative findings in congenital scoliosi,” Spine, vol. 28, no. 22, pp. 2531–2534, 2003.
[13]
L. M. R. Rodrigues, R. J. Nicolau, and C. Milani, “Computed tomographic evaluation of thoracic pedicle screw placement in idiopathic scoliosis,” Journal of Pediatric Orthopaedics Part B, vol. 20, no. 4, pp. 195–198, 2011.
[14]
K. A. Buckwalter, J. Rydberg, K. K. Kopecky, K. Crow, and E. L. Yang, “Musculoskeletal imaging with multislice CT,” American Journal of Roentgenology, vol. 176, no. 4, pp. 979–986, 2001.
[15]
A. K. Gupta, R. C. Nelson, G. A. Johnson, E. K. Paulson, D. M. Delong, and T. T. Yoshizumi, “Optimization of eight-element multi-detector row helical CT technology for evaluation of the abdomen,” Radiology, vol. 227, no. 3, pp. 739–745, 2003.
[16]
M. Yazici, E. R. Acaroglu, A. Alanay, V. Deviren, A. Cila, and A. Surat, “Measurement of vertebral rotation in standing versus supine position in adolescent idiopathic scoliosis,” Journal of Pediatric Orthopaedics, vol. 21, no. 2, pp. 252–256, 2001.
[17]
S. G？？en, M. G. Aksu, L. Baktiro？lu, and O. Ozcan, “Evaluation of computed tomographic methods to measure vertebral rotation in adolescent idiopathic scoliosis: an intraobserver and interobserver analysis,” Journal of Spinal Disorders, vol. 11, no. 3, pp. 210–214, 1998.
[18]
G. C. Lam, D. L. Hill, L. H. Le, J. V. Raso, and E. H. Lou, “Vertebral rotation measurement: a summary and comparison of common radiographic and CT methods,” Scoliosis, vol. 3, no. 1, article no. 16, 2008.
[19]
K. Abul-Kasim, M. K. Karlsson, R. Hasserius, and A. Ohlin, “Measurement of vertebral rotation in adolescent idiopathic scoliosis with low-dose CT in prone position—method description and reliability analysis,” Scoliosis, vol. 5, no. 1, article no. 4, 2010.
