• 제목/요약/키워드: Simplified contouring

검색결과 3건 처리시간 0.016초

Computer-Assisted Virtual Simulation and Surgical Treatment for Facial Asymmetry Induced by Fibrous Dysplasia

  • Lee, Jung-woo
    • Journal of International Society for Simulation Surgery
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    • 제3권1호
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    • pp.33-35
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    • 2016
  • Fibrous dysplasia(FD) is a disorder in which normal bone is replaced with pathologic tissue. When occurring in craniofacial regions, the zygomaticomaxillary complex is most commonly affected and this pathologic lesion results in facial asymmetry. and By using computer-assisted virtual simulation, precise maxillofacial contouring was achieved for harmonious facial morphology and the surgical procedure was simplified and the surgery brought satisfactory results in terms of both esthetics and functionality.

Use of Cardiac Computed Tomography for Ventricular Volumetry in Late Postoperative Patients with Tetralogy of Fallot

  • Kim, Ho Jin;Mun, Da Na;Goo, Hyun Woo;Yun, Tae-Jin
    • Journal of Chest Surgery
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    • 제50권2호
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    • pp.71-77
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    • 2017
  • Background: Cardiac computed tomography (CT) has emerged as an alternative to magnetic resonance imaging (MRI) for ventricular volumetry. However, the clinical use of cardiac CT requires external validation. Methods: Both cardiac CT and MRI were performed prior to pulmonary valve implantation (PVI) in 11 patients (median age, 19 years) who had undergone total correction of tetralogy of Fallot during infancy. The simplified contouring method (MRI) and semiautomatic 3-dimensional region-growing method (CT) were used to measure ventricular volumes. Results: All volumetric indices measured by CT and MRI generally correlated well with each other, except for the left ventricular end-systolic volume index (LV-ESVI), which showed the following correlations with the other indices: the right ventricular end-diastolic volume index (RV-EDVI) (r=0.88, p<0.001), the right ventricular end-systolic volume index (RV-ESVI) (r=0.84, p=0.001), the left ventricular end-diastolic volume index (LV-EDVI) (r=0.90, p=0.001), and the LV-ESVI (r=0.55, p=0.079). While the EDVIs measured by CT were significantly larger than those measured by MRI (median RV-EDVI: $197mL/m^2$ vs. $175mL/m^2$, p=0.008; median LV-EDVI: $94mL/m^2$ vs. $92mL/m^2$, p=0.026), no significant differences were found for the RV-ESVI or LV-ESVI. Conclusion: The EDVIs measured by cardiac CT were greater than those measured by MRI, whereas the ESVIs measured by CT and MRI were comparable. The volumetric characteristics of these 2 diagnostic modalities should be taken into account when indications for late PVI after tetralogy of Fallot repair are assessed.

Semiautomatic Three-Dimensional Threshold-Based Cardiac Computed Tomography Ventricular Volumetry in Repaired Tetralogy of Fallot: Comparison with Cardiac Magnetic Resonance Imaging

  • Hyun Woo Goo
    • Korean Journal of Radiology
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    • 제20권1호
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    • pp.102-113
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    • 2019
  • Objective: To assess the accuracy and potential bias of computed tomography (CT) ventricular volumetry using semiautomatic three-dimensional (3D) threshold-based segmentation in repaired tetralogy of Fallot, and to compare them to those of two-dimensional (2D) magnetic resonance imaging (MRI). Materials and Methods: This retrospective study evaluated 32 patients with repaired tetralogy of Fallot who had undergone both cardiac CT and MRI within 3 years. For ventricular volumetry, semiautomatic 3D threshold-based segmentation was used in CT, while a manual simplified contouring 2D method was used in MRI. The indexed ventricular volumes were compared between CT and MRI. The indexed ventricular stroke volumes were compared with the indexed arterial stroke volumes measured using phase-contrast MRI. The mean differences and degrees of agreement in the indexed ventricular and stroke volumes were evaluated using Bland-Altman analysis. Results: The indexed end-systolic (ES) volumes showed no significant difference between CT and MRI (p > 0.05), while the indexed end-diastolic (ED) volumes were significantly larger on CT than on MRI (93.6 ± 17.5 mL/m2 vs. 87.3 ± 15.5 mL/m2 for the left ventricle [p < 0.001] and 177.2 ± 39.5 mL/m2 vs. 161.7 ± 33.1 mL/m2 for the right ventricle [p < 0.001], respectively). The mean differences between CT and MRI were smaller for the indexed ES volumes (2.0-2.5 mL/m2) than for the indexed ED volumes (6.3-15.5 mL/m2). CT overestimated the stroke volumes by 14-16%. With phase-contrast MRI as a reference, CT (7.2-14.3 mL/m2) showed greater mean differences in the indexed stroke volumes than did MRI (0.8-3.3 mL/m2; p < 0.005). Conclusion: Compared to 2D MRI, CT ventricular volumetry using semiautomatic 3D threshold-based segmentation provides comparable ES volumes, but overestimates the ED and stroke volumes in patients with repaired tetralogy of Fallot.