Objective To evaluate the accuracy of the related parameters measured by spinal virtual surgery system (SVSS) three-dimensional (3D) techniques by comparing with the parameters measured by multi-spiral CT (MSCT) workstation. Methods Seven vertebrae specimens of adult men were scanned with MSCT, and the messages were sent toMSCT workstation and SVSS. The 3D image of spine was reconstructed by using volume rendering and multi-planar reformation; based on the parameter requirement of lower cervical pedicle fixation, 10 related parameters were measured. Then SPSS11.0 analyzer software was used to analyze the parameters measured by 2 systems. Between June 2009 and March 2010, 6 patients who received screw insertion in lower cervical spines were given MSCT scanning, then the messages were sent to SVSS 3D reconstruction to evaluate the situation and to collect the parameters of pedicle screw insertion. Results SVSS measurement showed that 1 pedicle was clausura (C3) and the diameters of 4 pedicles in coronal view were lee than 3 mm (C4 in 1, C5 in 2, C6 in 1), which did not fit for screw insertion; the results were similar to those by MSCT measurement. A total of 66 lower cervical pedicle were measured successfully. Significant differences were found in 14 parameters as follows between 2 systems (P lt; 0.05): the left pedicle height of C3, the both sides pedicle width of C4, the right pedicle spongy width of C4, the left X-direction entrance of C6, the both sides Y-direction entrance of C3, total pedicle length of sagittal view in both sides pedicle of C3 and the left pedicle of C5, total pedicle length of axial view in C3 pedicles, the left pedicle of C5, and the right pedicle of C6. There was no significantdifference in the other parameters (P gt; 0.05). In 6 cl inical cases, 34 screws were inserted, the postoperative MSCT scanning showed that 30 screws were placed successfully. The rate of accuracy was 88.24%. According to the Richter’s perforation classification, perforation at grade I and at grade II occurred in 2 cases (5.88%), respectively. Conclusion The accuracy of the parameters measured by SVSS is similar to that by MSCT.
Objective To study the feasibil ity and rel iabil ity of the multi-plannar reformation (MPR) of multispiral CT (MSCT) in measuring the kyphosis angle (KA) after thoracolumbar fracture. Methods From December 2007 to December 2009, 45 thoracolumbar fracture patients who underwent computed radiology (CR) and MSCT were recruited. There were 32 males and 13 females with a mean age of 48 years (range, 24-63 years), including 36 simple compression fractures and 9 burst fractures. The fracture locations were T11 in 6 cases , T12 in 11 cases, L1 in 20 cases, and L2 in 8 cases. Fracture was caused by trafffic accident in 25 cases, by fall ing from height in 12 cases, and by others in 8 cases. The imaging examination was performed after 2 hours to 7 days of injury in 22 cases and after more than 7 days in 23 cases. The KA was measured on the lateral X-ray films of CR and MPR by two observers, then the measurements were done again after three weeks. The data were statistically analyzed. Results The average KA values on CR by two observers were (20.75 ± 8.31)° and (22.49 ± 9.07)°, respectively; showing significant difference (P lt; 0.05), and the correlation was good (r=0.882, P lt; 0.05). The average KA values on MPR by two observers were (16.65 ± 8.62)° and (17.08 ± 7.88)°, respectively, showing no significant difference (P gt; 0.05), the correlation was excellent (r=0.976, P lt; 0.05). The average KA values on CR and MPR were (21.61 ± 8.43)° and (16.87 ± 8.20)°, respectively; showing significant difference (P lt; 0.05), the correlation was good (r=0.852, P lt; 0.05). Conclusion It is more feasible and rel iable in measuring the KA on MRP of MSCT than CR, but the value is larger on CR.
Objective To assess the cl inical significance of transpedicular screw insertion in lower cervical vertebra assisted by multi-spiral CT (MSCT) three dimentional (3D) image reconstruction techniques. Methods Eight cervical vertebra specimens were examined by MSCT, and the messages were sent to SGI02 Workstation; according to the parameter requirements of lower cervical pedicle fixation, by using post-process of volume rendering (VR) the condition was judged and multi-plannar reformation (MPR) was used to do individual analysis; and the ideal path of screw insertion was obtained andthe related parameters were measured. After preoperative plan being finished, referring to these measured parameters, 3.5 mm screws were inserted into C3-7 pedicles of these 8 specimens. After insertion of screws, MSCT scanning and 3D reconstruction were performed again to evaluate the accuracy of lower cervical pedicle screw inserting. From May 2007 to November 2009, 28 patients who received screw insertion in lower cervical spines were given MSCT scanning and 3D reconstruction to evaluate the illness situation, to confirm shortest fixation volumes, and to collect the parameters of aim pedicle screw insertion. Results The time of insertion for each screw was (392 ± 62) seconds. It was found that one pedicle was clausura (1.25%, 1/80) and five pedicle diameters in coronal view were less than 3 mm (6.25%, 5/80), which all were not fit for screw insertion. A total of 74 screws were placed successfully. One-time success rate of screw insertion was 95.95% (71/74). The total accuracy rate was 91.89% (68/74). Six screws penetrated (8.11%). According to the Richter penetrating classification: grade one was 6.76% (5/74) and grade two was 1.35% (1/74). There were significant differences (P lt; 0.05) in penetrated rate between our study and anatomic landmark local ization (47.37%), Miller methods (25.00%), and there was no significant difference (P gt; 0.05) when compared with Abumi method (6.70%), hopper method (7.10%), pipel ine deoppilation method (5.20%) and navigation technique (11.30%). In cl inical 28 cases, 121 screws were inserted; one pedicle was clausura and one was fissure fracture, which all were unfit for insert screw in preoperative plan, the surgery project was adjusted. After operation, 17 patients (76 screws) were given MSCT scanning again. A total of 67 screws (88.16%) were placed successfully. Nine screws (11.84%) penetrated, grade one was 7.89% (6/76) and grade two was 3.95% (3/76). Conclusion It is accurate to apply MSCT 3D reconstruction techniques to measure the ideal screw canal in preoperative individual ized plan. Strictly following individual quantitative data, the safety and accuracy of the surgery can be improved. And it is feasible and available to use MSCT MPR imaging to evaluate the accuracy of pedicle screw insertion.