| 1. |
- Abul-Kasim, Kasim, et al.
(författare)
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Low-dose helical computed tomography (CT) in the perioperative workup of adolescent idiopathic scoliosis.
- 2009
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 19, s. 610-618
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Tidskriftsartikel (refereegranskat)abstract
- The study aims were to estimate the radiation dose in patients examined with low dose spine CT and to compare it with that received by patients undergoing standard CT for trauma of the same region, as well as to evaluate the impact of dose reduction on image quality. Radiation doses in 113 consecutive low dose spine CTs were compared with those in 127 CTs for trauma. The inter- and intraobserver agreement in measurements of pedicular width, and vertebral rotation, measurements of signal-to-noise ratio and assessment of hardware status were the indicators in the evaluation of image quality. The effective dose of the low dose spine CT (0.37 mSv) was 20 times lower than that of a standard CT for trauma (13.09 mSv). This dose reduction conveyed no impact on image quality. This low dose spine CT protocol allows detailed evaluation that is necessary for preoperative planning and postoperative evaluation.
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| 2. |
- Abul-Kasim, Kasim, et al.
(författare)
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Radiation dose optimization in CT planning of corrective scoliosis surgery. A phantom study.
- 2008
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Ingår i: The Neuroradiology Journal. ; 21:3, s. 374-382
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to explore the possibility of obtaining a helical CT scan of a long segment of vertebral column, optimally reduce the radiation dose, compare the radiation dose of the low dose helical CT with that of some of the CT protocols used in clinical practice and finally assess the impact of such a dose reduction on the image quality. A chest phantom was examined with a 16-slice CT scanner. Six scans were performed with different radiation doses. The lowest radiation dose which had no impact on image quality with regard to the information required for surgical planning of patients with scoliosis, was 20 times lower than that of routinely used protocol for CT examination of the spine in children (0.38 mSv vs 7.76 mSv). Patients with scoliosis planned for corrective spinal surgery can be examined with low dose helical CT scan. The dose reduction systems (DRS) available in modern CT scanners contribute to dose reduction and should be used.
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| 3. |
- Abul-Kasim, Kasim, et al.
(författare)
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Radiological and clinical outcome of screw placement in adolescent idiopathic scoliosis: evaluation with low-dose computed tomography.
- 2010
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Ingår i: European Spine Journal. - : Springer Science and Business Media LLC. - 0940-6719 .- 1432-0932. ; 19:1, s. 96-104
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Tidskriftsartikel (refereegranskat)abstract
- Posterior corrective surgery using "all pedicle screw construct" carries risk of neurovascular complications. The study aims were to assess the screw placement in patients with adolescent idiopathic scoliosis using CT with low-radiation dose, and to evaluate the clinical outcome in patients with misplaced pedicle screws. CTs of 49 consecutive patients (873 screws, 79% thoracic) were retrospectively evaluated by two independent radiologists. A new grading system was developed to distinguish between lateral, medial and anterior cortical perforations, endplate perforation and foraminal perforation. The grading system is based on whether the cortical violation is partial or total rather than on mm-basis. The overall rate of screw misplacement was 17% (n = 149): 8% were laterally placed and 6.1% were medially placed. The rates of anterior cortical, endplate and foraminal perforation were 1.5, 0.9, and 0.5%, respectively. Lateral cortical perforation was more frequent in the thoracic spine (P = 0.005), whereas other types of misplacement including medial cortical perforation were more frequent on the left and the concave side of scoliotic curves (P = 0.002 and 0.003). No neurovascular complications were reported. The association between the occurrence of screw misplacement and the Cobb angle was statistically significant (P = 0.037). Misplacements exceeding half screw diameter should be classified as unacceptable. Low-dose CT implies exposing these young individuals to a significantly lower radiation dose than do other protocols used in daily clinical practice. We recommend using low-dose CT and the grading system proposed here in the postoperative assessment of screw placement.
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| 4. |
- Abul-Kasim, Kasim, et al.
(författare)
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Reliability of Low-Radiation Dose CT in the Assessment of Screw Placement After Posterior Scoliosis Surgery, Evaluated With a New Grading System
- 2009
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Ingår i: Spine. - 0362-2436. ; 34:9, s. 941-948
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Tidskriftsartikel (refereegranskat)abstract
- Study Design. A retrospective study. Objective. To evaluate the reliability of computed tomography (CT) with low radiation dose in the assessment of implant status in patients with adolescent idiopathic scoliosis (AIS). Summary of Background Data. The use of all-pedicle screw construct in scoliosis corrective surgery continues to gain increasing popularity since their introduction 1994 although their use in the thoracic spine carries a potential risk for neurovascular complications. CT is the method widely used to evaluate screw placement. Methods. Retrospective analysis of 46 consecutive low-dose spine CT in patients with AIS after posterior corrective surgery. Status of 809 titanium screws (642 thoracic) was evaluated. The degree of interobserver and intraobserver agreements about implant status was used as an indicator of the reliability of the low-dose spine CT in the assessment of accuracy of pedicle screw insertion. A new grading system has been developed for this purpose. Five types of misplacement have been evaluated: lateral, medial, and anterior cortical perforations; end-plate perforation; and foraminal perforation. Results. The analysis has shown a substantial interobserver and intraobserver agreements (kappa: 0.69 and 0.76, respectively) in differentiating pedicle screws with acceptable placement from screws with partial or total cortical perforation. None of the examinations was subjectively classified as unreliable. Conclusion. The study has shown that low-dose spine CT is a reliable method in evaluating screw placement in patients with AIS after posterior scoliosis surgery with titanium implants, using the here proposed grading system. The new grading system of screw misplacement was feasible and in line with the general agreement about the harmlessness of misplacement with minor pedicle breach. The reliability of low-dose spine CT in evaluation of lateral and medial cortical perforations was substantial. To reduce the radiation load, the postoperative assessment of titanium implants should be performed with low-dose CT.
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| 5. |
- Möller, Anders, et al.
(författare)
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A vertebral fracture in childhood is not a risk factor for disc degeneration but for Schmorl's nodes: a mean 40-year observational study.
- 2007
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Ingår i: Spine. - 0362-2436. ; 32:22, s. 2487-2492
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Observational cohort study. OBJECTIVE: To evaluate by MRI whether a vertebral fracture during childhood is a risk factor for degeneration of adjacent discs. SUMMARY OF BACKGROUND DATA: Several studies infer that trauma is a major cause of disc degeneration. Only 1 study has by magnetic resonance imaging (MRI) evaluated disc degeneration in children with a former thoracic or lumbar vertebral fracture. That study reported a 50% prevalence of degenerative disc changes 4 years after the fracture. However, due to the sparse literature, it is still unclear whether a vertebral fracture in childhood represents a risk factor for disc degeneration in a long-term perspective. METHOD: Nine boys and 11 girls with a mean age of 12 years (range, 7-16 years) when sustaining a lumbar or thoracic vertebral fracture without neurologic deficits were examined at a mean of 40 years (range, 33-53 years) after the injury. Eighteen of the subjects had 1-column compression fractures, and 2 had Denis Type B burst fractures. All were mobilized without brace or surgery directly after being injured. A favorable long-term clinical and plain radiographic outcome has previously been reported for this cohort. In the present study, the intervertebral discs were evaluated with MRI by applying the Oner classification scheme. Degenerative disc changes were defined as loss of signal intensity on T2-weighted images with or without disc height reduction. RESULTS: Degenerative changes were not more prevalent in discs adjacent to the previously fractured vertebrae than in discs at a distance from those segments. However, there were more Schmorl's nodes at the disc levels adjacent to the earlier fractures. CONCLUSION: Stable vertebral fractures in childhood with no neurologic deficits at injury do not render more degenerative changes than can be expected according to age, but they are associated with more Schmorl's nodes at adjacent disc levels.
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