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Chen Y, Yang J, Liang J, Wu W. The optimal introversion angle and length of pedicle screw to avoid L1-S1 vascular damage. BMC Surg 2024; 24:194. [PMID: 38907190 PMCID: PMC11191234 DOI: 10.1186/s12893-024-02483-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 06/14/2024] [Indexed: 06/23/2024] Open
Abstract
BACKGROUND posterior pedicle screw fixation is common method, one of the most severe complications is iatrogenic vascular damage, no report investigated association of different introversion angles (INTAs) and length of pedicle screw. The aims were to investigate the optimal introversion angle and length of pedicle screw for improving the safety of the operation, and to analyze the differences of vascular damage types at L1-S1. METHODS Lumbar CT imaging data from110 patients were analyzed by DICOM software, and all parameters were measured by new Cartesian coordinate system, INTAs (L1-L5:5°,10°,15°,S1: 0°, 5°,10°,15°), DO-AVC (the distance between the origin (O) with anterior vertebral cortex (AVC)), DAVC-PGVs (the distance between AVC and the prevertebral great vessels (PGVs)), DO-PGVs (the distance between the O and PGVs). At different INTAs, DAVC-PGVs were divided into four grades: Grade III: DAVC-PGVs ≤ 3 mm, Grade II: 3 mm < DAVC-PGVs ≤ 5 mm, Grade I: DAVC-PGVs > 5 mm, and N: the not touching PGVs. RESULTS The optimal INTA was 5° at L1-L3, the left was 5° and the right was 15° at L4, and screw length was less than 50 mm at L1-L4. At L5, the left optimal INTA was 5° and the right was 10°, and screw length was less than 45 mm. The optimal INTA was 15° at S1, and screw length was less than 50 mm. However, screw length was less than 40 mm when the INTA was 0° or 5° at S1. CONCLUSIONS At L5-S1, the risk of vascular injury is the highest. INTA and length of the pedicle screw in lumbar operation are closely related. 3 mm interval of screw length may be more preferable to reduce vascular damage.
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Affiliation(s)
- Ying Chen
- Yichang Central People's Hospital Hubei, Hubei, China
| | - Junyi Yang
- Department of Orthopedics, The First College of Clinical Medical Science, China Three Gorges University, Hubei, China
| | - Jie Liang
- Department of Orthopedics, The First College of Clinical Medical Science, China Three Gorges University, Hubei, China
- Yichang Central People's Hospital Hubei, Hubei, China
| | - Weifei Wu
- Department of Orthopedics, The First College of Clinical Medical Science, China Three Gorges University, Hubei, China.
- Yichang Central People's Hospital Hubei, Hubei, China.
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Tanaka M, Schol J, Sakai D, Sako K, Yamamoto K, Yanagi K, Hiyama A, Katoh H, Sato M, Watanabe M. Low Radiation Protocol for Intraoperative Robotic C-Arm Can Enhance Adolescent Idiopathic Scoliosis Deformity Correction Accuracy and Safety. Global Spine J 2024; 14:1504-1514. [PMID: 36695112 DOI: 10.1177/21925682221147867] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
STUDY DESIGN Retrospective case-series study. OBJECTIVES To assess (1) low cone beam CT (CBCT) mediated intraoperative navigation to limit radiation exposure without compromising surgical accuracy, and (2) the potential of intraoperative C-arm CBCT navigation to augment pedicle screw (PS) placement accuracy in AIS surgery compared to pre-surgery CT-based planning. METHODS The first part involved a prospective phantom study, comparing radiation doses for conventional CT, and standard (6sDCT) and a low dose (5sDCT) Artis Zeego®-imaging. Next, 5sDCT- and 6sDCT-navigation were compared on PS accuracy and radiation exposure during AIS correction. The final part compared surgical AIS deformity correction through intraoperative 5sDCT navigation to a matched cohort treated using conventional pre-surgery CT-scans for navigation. Outcome parameters included operation time, skin dose (SD), dose area product (DAP), intraoperative blood loss, postoperative complications, and PS deviation rates. RESULTS The phantom study demonstrated a reduction in radiation for the 5sDCT protocol. Moreover, 5sDCT-imaged patients (n = 15) showed a significantly lower SD (-27.41%) and DAP (-30.92%), without compromising PS accuracy compared with 6sDCT-settings (n = 15). Finally, AIS correction through intraoperative CBCT C-arm navigation (n = 27) significantly reduced screw deviation rates (6.83% versus 10.75%, P = .016) without increasing operation times, compared with conventional CT (n = 37). CONCLUSIONS Intraoperative navigation using a CBCT C-arm system improved the accuracy of PS insertion and reduced surgery time. Moreover, it reduced radiation exposure compared with conventional CT, which was further curtailed by adapting the low-dose 5sDCT protocol. In short, our study highlights the benefits of intraoperative CBCT navigation for PS placement in AIS surgery.
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Affiliation(s)
- Masahiro Tanaka
- Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - Jordy Schol
- Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - Daisuke Sakai
- Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - Kosuke Sako
- Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - Kazuyuki Yamamoto
- Department of Diagnostic Radiology, Tokai University School of Medicine, Kanagawa, Japan
| | - Kensuke Yanagi
- Department of Diagnostic Radiology, Tokai University School of Medicine, Kanagawa, Japan
| | - Akihiko Hiyama
- Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - Hiroyuki Katoh
- Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - Masato Sato
- Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
| | - Masahiko Watanabe
- Department of Orthopaedic Surgery, Tokai University School of Medicine, Kanagawa, Japan
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Haemmerli J, Ferdowssian K, Wessels L, Mertens R, Hecht N, Woitzik J, Schneider UC, Bayerl SH, Vajkoczy P, Czabanka M. Comparison of intraoperative CT- and cone beam CT-based spinal navigation for the treatment of atlantoaxial instability. Spine J 2023; 23:1799-1807. [PMID: 37619869 DOI: 10.1016/j.spinee.2023.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 07/18/2023] [Accepted: 08/13/2023] [Indexed: 08/26/2023]
Abstract
BACKGROUND CONTEXT Due to the complexity of neurovascular structures in the atlantoaxial region, spinal navigation for posterior C1-C2 instrumentation is nowadays a helpful tool to increase accuracy of surgery and safety of patients. Many available intraoperative navigation devices have proven their reliability in this part of the spine. Two main imaging techniques are used: intraoperative CT (iCT) and cone beam computed tomography (CBCT). PURPOSE Comparison of iCT- and CBCT-based technologies for navigated posterior instrumentation in C1-C2 instability. STUDY DESIGN Retrospective study. PATIENT SAMPLE A total of 81 consecutive patients from July 2014 to April 2020. OUTCOME MEASURES Screw accuracy and operating time. METHODS Patients with C1-C2 instability received posterior instrumentation using C2 pedicle screws, C1 lateral mass or pedicle screws. All screws were inserted using intraoperative imaging either using iCT or CBCT systems and spinal navigation with autoregistration technology. Following navigated screw insertion, a second intraoperative scan was performed to assess the accuracy of screw placement. Accuracy was defined as the percentage of correctly placed screws or with minor cortical breach (<2 mm) as graded by an independent observer compared to misplaced screws. RESULTS A total of 81 patients with C1-C2 instability were retrospectively analyzed. Of these, 34 patients were operated with the use of iCT and 47 with CBCT. No significant demographic difference was found between groups. In the iCT group, 97.7% of the C1-C2 screws were correctly inserted; 2.3% showed a minor cortical breach (<2 mm); no misplacement (>2 mm). In the CBCT group, 98.9% of screws were correctly inserted; no minor pedicle breach; 1.1% showed misplacement >2 mm. Accuracy of screw placement demonstrated no significant difference between groups. Both technologies allowed sufficient identification of screw misplacement intraoperatively leading to two screw revisions in the iCT and three in the CBCT group. Median time of surgery was significantly shorter using CBCT technology (166.5 minutes [iCT] vs 122 minutes [CBCT]; p<.01). CONCLUSIONS Spinal navigation using either iCT- or CBCT-based systems with autoregistration allows safe and reliable screw placement and intraoperative assessment of screw positioning. Using the herein presented procedural protocols, CBCT systems allow shorter operating time.
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Affiliation(s)
- Julien Haemmerli
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
| | - Kiarash Ferdowssian
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
| | - Lars Wessels
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
| | - Robert Mertens
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
| | - Nils Hecht
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
| | - Johannes Woitzik
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
| | - Ulf C Schneider
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
| | - Simon H Bayerl
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
| | - Peter Vajkoczy
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany.
| | - Marcus Czabanka
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Charitéplatz 1, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin 10117, Germany
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Ohashi H, Kawamura D, Hatano K, Ohashi S, Tochigi S, Isoshima A, Nagashima H, Otani K, Karagiozov K, Tani S, Murayama Y. Intraoperative Cone-Beam Computed Tomography Assessment of Spinal Pedicle Screws Placement Precision Is in Full Agreement with Postoperative Computed Tomography Assessment. World Neurosurg 2023; 175:e254-e263. [PMID: 36966912 DOI: 10.1016/j.wneu.2023.03.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 04/30/2023]
Abstract
OBJECTIVE To assess agreement between pedicle screw placement evaluated on postoperative computed tomography (CT) and on intraoperative cone-beam CT (CBCT) and compare procedure characteristics when using first-generation and second-generation robotic C-arm systems in the hybrid operating room. METHODS All patients who received pedicle screws for spinal fusion at our institution between June 2009 and September 2019 and underwent intraoperative CBCT and postoperative CT were included. The CBCT and CT images were reviewed by 2 surgeons to assess the screw placement using the Gertzbein-Robbins and the Heary classifications. Intermethod agreement of screw placement classifications as well as interrater agreement were assessed using Brennan-Prediger and Gwet agreement coefficients. Procedure characteristics using first-generation and second-generation generation robotic C-arm systems were compared. RESULTS Fifty-seven patients were treated with 315 pedicle screws at thoracic, lumbar, and sacral levels. No screw had to be repositioned. On CBCT, accurate placement was found for 309 screws (98.1%) using the Gertzbein-Robbins classification and 289 (91.7%) using the Heary classification and on CT, these were 307 (97.4%) and 293 (93.0%), respectively. Intermethod between CBCT and CT and interrater agreements between the 2 raters were almost perfect (>0.90) for all assessment. There were no significant differences in mean radiation dose (P = 0.83) and fluoroscopy time (P = 0.82), but length of surgery using the second-generation system was estimated at 107.7 minutes (95% confidence interval, 31.9-183.5 minutes; P = 0.006) shorter. CONCLUSIONS Intraoperative CBCT provides accurate assessment of pedicle screw placement and enables intraoperative repositioning of misplaced screws.
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Affiliation(s)
- Hiroki Ohashi
- Department of Neurosurgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan.
| | - Daichi Kawamura
- Department of Neurosurgery, Jikei University School of Medicine Kashiwa Hospital, Kashiwa, Chiba, Japan
| | - Keisuke Hatano
- Department of Neurosurgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - So Ohashi
- Department of Neurosurgery, Jikei University School of Medicine Kashiwa Hospital, Kashiwa, Chiba, Japan
| | - Satoru Tochigi
- Department of Neurosurgery, Jikei University School of Medicine Kashiwa Hospital, Kashiwa, Chiba, Japan
| | - Akira Isoshima
- Department of Neurosurgery, Omori Red Cross Hospital, Ota-ku, Tokyo, Japan
| | - Hiroyasu Nagashima
- Department of Neurosurgery, Jikei University School of Medicine Katsushika Medical Center, Katsushika-ku, Tokyo, Japan
| | - Katharina Otani
- Siemens Healthcare K.K., AT Innovation Department, Gate City Osaki West Tower, Shinagawa-ku, Tokyo, Japan
| | - Kostadin Karagiozov
- Department of Neurosurgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Satoshi Tani
- Department of Neurosurgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Yuichi Murayama
- Department of Neurosurgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
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Zimmermann F, Kohl K, Mandelka E, Grützner PA, Franke J, Vetter SY. Is the postoperative pedicle screw position after dorsal instrumentation with or without intraoperative cone beam CT imaging worse in patients with obesity than in normal-weight patients? J Orthop Surg Res 2022; 17:474. [PMID: 36329438 PMCID: PMC9632097 DOI: 10.1186/s13018-022-03369-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
Background Intraoperative cone beam CT (CBCT) imaging in dorsal instrumentation facilitates pedicle screw positioning. However, in patients with obesity, the benefit may be reduced due to artifacts that affect image quality. The purpose of this study was to evaluate whether intraoperative CBCT leads to an improved postoperative screw position compared to conventional fluoroscopy independent of body weight. Methods A total of 71 patients (18 patients with a BMI > 30 kg/m2, 53 patients with a BMI < 30 kg/m2) who underwent dorsal instrumentation with intraoperative CBCT imaging were included in study groups one (SG1) and two (SG2). Two control groups (CG1 and CG2) were randomly sampled to include 22 patients with a BMI > 30 kg/m2 and 60 patients with a BMI < 30 kg/m2 who underwent dorsal instrumentation without intraoperative CBCT imaging. The pedicle screw position in postoperative computed tomography was assessed using the Gertzbein–Robbins classification. Results In SG1 (BMI > 30 kg/m2), a total of 107 (83.6%) pedicle screws showed no relevant perforation (type A + B), and 21 (16.4%) pedicle screws showed relevant perforation (type C − E). In SG2 (BMI < 30 kg/m2), 328 (90.9%) screws were classified as type A + B, and 33 (9.1%) screws were classified as type C − E. In CG1 (BMI > 30 kg/m2), 102 (76.1%) pedicle screws showed no relevant perforation (type A + B), and 32 (23.9%) pedicle screws showed relevant perforation (type C − E). In CG2 (BMI < 30 kg/m2), 279 (76.9%) screws were classified as type A + B, and 84 (23.1%) screws were classified as type C − E. There were significant differences between the values of SG1 and SG2 (p = 0.03) and between the values of SG2 and CG2 (p < 0.0001). Conclusion CBCT imaging in dorsal instrumentation can lead to an improved pedicle screw position among both patients with obesity and normal-weight patients. However, patients with obesity showed significantly worse pedicle screw positions postoperatively after dorsal instrumentation with intraoperative CBCT imaging than normal-weight patients.
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Affiliation(s)
- Felix Zimmermann
- grid.418303.d0000 0000 9528 7251BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071 Ludwigshafen am Rhein, Germany
| | - Katharina Kohl
- grid.418303.d0000 0000 9528 7251BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071 Ludwigshafen am Rhein, Germany
| | - Eric Mandelka
- grid.418303.d0000 0000 9528 7251BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071 Ludwigshafen am Rhein, Germany
| | - Paul A. Grützner
- grid.418303.d0000 0000 9528 7251BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071 Ludwigshafen am Rhein, Germany
| | - Jochen Franke
- grid.418303.d0000 0000 9528 7251BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071 Ludwigshafen am Rhein, Germany
| | - Sven Y. Vetter
- grid.418303.d0000 0000 9528 7251BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071 Ludwigshafen am Rhein, Germany
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Matsuoka A, Toyone T, Okano I, Kudo Y, Ishikawa K, Maruyama H, Ozawa T, Shirahata T, Inagaki K. Comparison of pedicle screw placement accuracy between two types of imaging support (Artis Zeego versus two-dimensional fluoroscopy): a cross-sectional observational study. BMC Musculoskelet Disord 2022; 23:644. [PMID: 35790951 PMCID: PMC9254419 DOI: 10.1186/s12891-022-05602-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 06/28/2022] [Indexed: 02/07/2023] Open
Abstract
Background The pedicle screw system is widely used in spine surgery, and it provides rigid fixation and leads to successful subsequent deformity correction and bony fusion. The standard imaging technique for pedicle screw insertion is two-dimensional images obtained from C-arm-type X-ray fluoroscopy. Artis Zeego is an emerging intraoperative imaging technique that can provide conventional two-dimensional fluoroscopic images and rapid three-dimensional fluoroscopic computed tomography reconstruction imaging. The aim of this study is to compare the insertion accuracies of PS placement using Artis Zeego and conventional 2D X-ray fluoroscopy. Methods In this study, we retrospectively reviewed the postoperative images of thoracolumbar fusion patients who underwent surgery using pedicle screws between 2013 and 2018. Pedicle screw malplacement was assessed using a four-grade classification by Rao et al. Misplacement rates were compared between pedicle screws assisted with Artis Zeego and two-dimensional fluoroscopy. Results A total of 1107 pedicle screws in 153 patients were inserted using Artis Zeego, and 427 pedicle screws in 80 patients were inserted using fluoroscopy. The overall perforation rate was 4.2% (46 perforations of 1106 pedicle screws) in the Artis Zeego group and 7.7% (33 perforations of 427 pedicle screws) in the fluoroscopy group. In the Artis Zeego group, 43 (3.9%) screws were classified as grade 1, and three (0.3%) screws were classified as grade 2. In the fluoroscopy group, 21 (4.9%) screws were classified as grade 1, 10 (2.3%) screws were classified as grade 2, and 2 (0.5%) screws were classified as grade 3. The use of Artis Zeego was associated with a significantly lower screw malplacement rate than was the use of fluoroscopy (p < 0.001). Conclusions Our results demonstrated that pedicle screw placement with Artis Zeego was associated with a lower malplacement rate than was conventional two-dimensional fluoroscopy. No severe malplacement was observed in the Artis Zeego group. Thus, Artis Zeego could be a good option for improving pedicle screw accuracy.
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Kendlbacher P, Tkatschenko D, Czabanka M, Bayerl S, Bohner G, Woitzik J, Vajkoczy P, Hecht N. Workflow and performance of intraoperative CT, cone-beam CT, and robotic cone-beam CT for spinal navigation in 503 consecutive patients. Neurosurg Focus 2022; 52:E7. [PMID: 34973677 DOI: 10.3171/2021.10.focus21467] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/13/2021] [Indexed: 12/27/2022]
Abstract
OBJECTIVE A direct comparison of intraoperative CT (iCT), cone-beam CT (CBCT), and robotic cone-beam CT (rCBCT) has been necessary to identify the ideal imaging solution for each individual user's need. Herein, the authors sought to analyze workflow, handling, and performance of iCT, CBCT, and rCBCT imaging for navigated pedicle screw instrumentation across the entire spine performed within the same surgical environment by the same group of surgeons. METHODS Between 2014 and 2018, 503 consecutive patients received 2673 navigated pedicle screws using iCT (n = 1219), CBCT (n = 646), or rCBCT (n = 808) imaging during the first 24 months after the acquisition of each modality. Clinical and demographic data, workflow, handling, and screw assessment and accuracy were analyzed. RESULTS Intraoperative CT showed image quality and workflow advantages for cervicothoracic cases, obese patients, and long-segment instrumentation, whereas CBCT and rCBCT offered independent handling, around-the-clock availability, and the option of performing 2D fluoroscopy. All modalities permitted reliable intraoperative screw assessment. Navigated screw revision was possible with each modality and yielded final accuracy rates > 92% in all groups (iCT 96.2% vs CBCT 92.3%, p < 0.001) without a difference in the accuracy of cervical pedicle screw placement or the rate of secondary screw revision surgeries. CONCLUSIONS Continuous training and an individual setup of iCT, CBCT, and rCBCT has been shown to permit safe and precise navigated posterior instrumentation across the entire spine with reliable screw assessment and the option of immediate revision. The perceived higher image quality and larger scan area of iCT should be weighed against the around-the-clock availability of CBCT and rCBCT technology with the option of single-handed robotic image acquisition.
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Affiliation(s)
- Paul Kendlbacher
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin.,2Department of Neurosurgery, Goethe Universität Frankfurt, Frankfurt am Main
| | | | - Marcus Czabanka
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin.,2Department of Neurosurgery, Goethe Universität Frankfurt, Frankfurt am Main
| | - Simon Bayerl
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin
| | - Georg Bohner
- 3Department of Neuroradiology, Charité-Universitätsmedizin Berlin; and
| | - Johannes Woitzik
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin.,4Department of Neurosurgery, University at Oldenburg, Germany
| | - Peter Vajkoczy
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin
| | - Nils Hecht
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin
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Zimmermann F, Kohl K, Privalov M, Franke J, Vetter SY. Intraoperative 3D imaging with cone-beam computed tomography leads to revision of pedicle screws in dorsal instrumentation: a retrospective analysis. J Orthop Surg Res 2021; 16:706. [PMID: 34863238 PMCID: PMC8642936 DOI: 10.1186/s13018-021-02849-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/15/2021] [Indexed: 12/11/2022] Open
Abstract
Background Correct positioning of pedicle screws can be challenging. Intraoperative imaging may be helpful. The purpose of this study was to evaluate the use of intraoperative 3D imaging with a cone-beam CT. The hypotheses were that intraoperative 3D imaging (1) will lead to an intraoperative revision of pedicle screws and (2) may diminish the rate of perforated screws on postoperative imaging. Methods Totally, 351 patients (age 60.9 ± 20.3 a (15–96); m/f 203/148) underwent dorsal instrumentation with intraoperative 3D imaging with 2215 pedicle screws at a trauma center level one. This study first evaluates intraoperative imaging. After this, 501 screws in 73 patients (age 62.5 ± 19.7 a; m/f 47/26) of this collective were included in the study group (SG) and their postoperative computed tomography was evaluated with regard to screw position. Then, 500 screws in 82 patients (age 64.8 ± 14.4 a; m/f 51/31) as control group (CG), who received the screws with conventional 2D fluoroscopy but without 3D imaging, were evaluated with regard to screw position. Results During the placement of the 2215 pedicle screws, 158 (7.0%) intraoperative revisions occurred as a result of 3D imaging. Postoperative computed tomography of the SG showed 445 (88.8%) screws without relevant perforation (type A + B), of which 410 (81.8%) could be classified as type A and 35 (7.0%) could be classified as type B. Fifty-six (11.2%) screws in SG showed relevant perforation (type C–E). In contrast, 384 (76.8%) screws in the CG were without relevant perforation (type A + B), of which 282 (56.4%) could be classified as type A and 102 (20.4%) as type B. One hundred and sixteen (23.2%) screws in the CG showed relevant perforation (type C–E). Conclusion This study shows that correct placement of pedicle screws in spine surgery with conventional 2D fluoroscopy is challenging. Misplacement of screws cannot always be prevented. Intraoperative 3D imaging with a CBCT can be helpful to detect and revise misplaced pedicle screws intraoperatively. The use of intraoperative 3D imaging will probably minimize the number of revision procedures due to perforating pedicle screws.
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Affiliation(s)
- Felix Zimmermann
- BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071, Ludwigshafen am Rhein, Germany
| | - Katharina Kohl
- BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071, Ludwigshafen am Rhein, Germany
| | - Maxim Privalov
- BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071, Ludwigshafen am Rhein, Germany
| | - Jochen Franke
- BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071, Ludwigshafen am Rhein, Germany
| | - Sven Y Vetter
- BG Klinik Ludwigshafen, Ludwig-Guttmann-Straße 13, 67071, Ludwigshafen am Rhein, Germany.
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Enders F, Rothfuss A, Brehmer S, Stallkamp J, Schulte DM, Hänggi D. Optimized Intraoperative Imaging for Stereotactic Planning with a Multiaxial Robotic C-arm System: Technical Note and Case Series. J Neurol Surg A Cent Eur Neurosurg 2021; 83:588-595. [PMID: 34781408 DOI: 10.1055/s-0041-1731754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND The preoperative preparation of the planning dataset for frame-based stereotactic brain biopsy is often associated with logistical effort and burden on the patient. Intraoperative imaging modalities need to be investigated to overcome these limitations. OBJECTIVE The objective of the study was to develop and apply a new method for the intraoperative acquisition of the planning dataset with the multiaxial robotic C-arm system Artis zeego. METHODS An indication-customized dose-reduced protocol for Artis zeego was developed and implemented into the workflow. A sample of 14 patients who had undergone intraoperative imaging with Artis zeego was analyzed. A sample of 10 patients with conventional preoperative imaging by cranial computed tomography (CT) was used as a control group. Outcomes were compared with regard to target deviation, diagnostic value of the biopsies, complications, and procedure time. RESULTS In all patients, a suitable intraoperative planning dataset could be acquired with Artis zeego. Total procedure time was shorter for the Artis zeego group (p = 0.01), whereas time in the operating room area was longer in the Artis zeego group (p = 0.04). Biopsy results were diagnostic in 12 patients (86%) in the Artis zeego group and in 8 patients (80%) in the control group. There were no significant differences in target size, trajectory length, or target deviation. CONCLUSION Intraoperative imaging for frame-based stereotactic brain biopsy with Artis zeego is an easy and feasible method. Accuracy is comparable to conventional CT, whereas radiation exposure could be additionally reduced. It allows a significant reduction of the total procedure length and improves the comfort for the patient and staff.
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Affiliation(s)
- Frederik Enders
- Department of Neurosurgery, University Hospital Mannheim, Mannheim, Germany
| | - Andreas Rothfuss
- Fraunhofer IPA Mannheim - Fraunhofer-Projektgruppe für Automatisierung in der Medizin und Biotechnologie PAMB, Mannheim, Germany
| | - Stefanie Brehmer
- Department of Neurosurgery, University Hospital Mannheim, Mannheim, Germany
| | - Jan Stallkamp
- Fraunhofer IPA Mannheim - Fraunhofer-Projektgruppe für Automatisierung in der Medizin und Biotechnologie PAMB, Mannheim, Germany
| | | | - Daniel Hänggi
- Department of Neurosurgery, University Hospital Mannheim, Mannheim, Germany.,Department of Neurosurgery, University Hospital Dusseldorf, Dusseldorf, Nordrhein-Westfalen, Germany
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Zhao C, Herbst M, Weber T, Luckner C, Vogt S, Ritschl L, Kappler S, Siewerdsen JH, Zbijewski W. Slot-scan dual-energy bone densitometry using motorized X-ray systems. Med Phys 2021; 48:6673-6695. [PMID: 34628651 DOI: 10.1002/mp.15272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/31/2021] [Accepted: 09/24/2021] [Indexed: 11/12/2022] Open
Abstract
PURPOSE We investigate the feasibility of slot-scan dual-energy (DE) bone densitometry on motorized radiographic equipment. This approach will enable fast quantitative measurements of areal bone mineral density (aBMD) for opportunistic evaluation of osteoporosis. METHODS We investigated DE slot-scan protocols to obtain aBMD measurements at the lumbar spine (L-spine) and hip using a motorized x-ray platform capable of synchronized translation of the x-ray source and flat-panel detector (FPD). The slot dimension was 5 × 20 cm2 . The DE slot views were processed as follows: (1) convolution kernel-based scatter correction, (2) unfiltered backprojection to tile the slots into long-length radiographs, and (3) projection-domain DE decomposition, consisting of an initial adipose-water decomposition in a bone-free region followed by water-CaHA decomposition with adjustment for adipose content. The accuracy and reproducibility of slot-scan aBMD measurements were investigated using a high-fidelity simulator of a robotic x-ray system (Siemens Multitom Rax) in a total of 48 body phantom realizations: four average bone density settings (cortical bone mass fraction: 10-40%), four body sizes (waist circumference, WC = 70-106 cm), and three lateral shifts of the body within the slot field of view (FOV) (centered and ±1 cm off-center). Experimental validations included: (1) x-ray test-bench feasibility study of adipose-water decomposition and (2) initial demonstration of slot-scan DE bone densitometry on the robotic x-ray system using the European Spine Phantom (ESP) with added attenuation (polymethyl methacrylate [PMMA] slabs) ranging 2 to 6 cm thick. RESULTS For the L-spine, the mean aBMD error across all WC settings ranged from 0.08 g/cm2 for phantoms with average cortical bone fraction wcortical = 10% to ∼0.01 g/cm2 for phantoms with wcortical = 40%. The L-spine aBMD measurements were fairly robust to changes in body size and positioning, e.g., coefficient of variation (CV) for L1 with wcortical = 30% was ∼0.034 for various WC and ∼0.02 for an obese patient (WC = 106 cm) changing lateral shift. For the hip, the mean aBMD error across all phantom configurations was about 0.07 g/cm2 for a centered patient. The reproducibility of hip aBMD was slightly worse than in the L-spine (e.g., in the femoral neck, the CV with respect to changing WC was ∼0.13 for phantom realizations with wcortical = 30%) due to more challenging scatter estimation in the presence of an air-tissue interface within the slot FOV. The aBMD of the hip was therefore sensitive to lateral positioning of the patient, especially for obese patients: e.g., the CV with respect to patient lateral shift for femoral neck with WC = 106 cm and wcortical = 30% was 0.14. Empirical evaluations confirmed substantial reduction in aBMD errors with the proposed adipose estimation procedure and demonstrated robust aBMD measurements on the robotic x-ray system, with aBMD errors of ∼0.1 g/cm2 across all three simulated ESP vertebrae and all added PMMA attenuator settings. CONCLUSIONS We demonstrated that accurate aBMD measurements can be obtained on a motorized FPD-based x-ray system using DE slot-scans with kernel-based scatter correction, backprojection-based slot view tiling, and DE decomposition with adipose correction.
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Affiliation(s)
- Chumin Zhao
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | | | | | | | | | | | | | - Jeffrey H Siewerdsen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Wojciech Zbijewski
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
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Zhang X, Uneri A, Wu P, Ketcha MD, Jones CK, Huang Y, Lo SFL, Helm PA, Siewerdsen JH. Long-length tomosynthesis and 3D-2D registration for intraoperative assessment of spine instrumentation. Phys Med Biol 2021; 66:055008. [PMID: 33477120 DOI: 10.1088/1361-6560/abde96] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE A system for long-length intraoperative imaging is reported based on longitudinal motion of an O-arm gantry featuring a multi-slot collimator. We assess the utility of long-length tomosynthesis and the geometric accuracy of 3D image registration for surgical guidance and evaluation of long spinal constructs. METHODS A multi-slot collimator with tilted apertures was integrated into an O-arm system for long-length imaging. The multi-slot projective geometry leads to slight view disparity in both long-length projection images (referred to as 'line scans') and tomosynthesis 'slot reconstructions' produced using a weighted-backprojection method. The radiation dose for long-length imaging was measured, and the utility of long-length, intraoperative tomosynthesis was evaluated in phantom and cadaver studies. Leveraging the depth resolution provided by parallax views, an algorithm for 3D-2D registration of the patient and surgical devices was adapted for registration with line scans and slot reconstructions. Registration performance using single-plane or dual-plane long-length images was evaluated and compared to registration accuracy achieved using standard dual-plane radiographs. RESULTS Longitudinal coverage of ∼50-64 cm was achieved with a single long-length slot scan, providing a field-of-view (FOV) up to (40 × 64) cm2, depending on patient positioning. The dose-area product (reference point air kerma × x-ray field area) for a slot scan ranged from ∼702-1757 mGy·cm2, equivalent to ∼2.5 s of fluoroscopy and comparable to other long-length imaging systems. Long-length scanning produced high-resolution tomosynthesis reconstructions, covering ∼12-16 vertebral levels. 3D image registration using dual-plane slot reconstructions achieved median target registration error (TRE) of 1.2 mm and 0.6° in cadaver studies, outperforming registration to dual-plane line scans (TRE = 2.8 mm and 2.2°) and radiographs (TRE = 2.5 mm and 1.1°). 3D registration using single-plane slot reconstructions leveraged the ∼7-14° angular separation between slots to achieve median TRE ∼2 mm and <2° from a single scan. CONCLUSION The multi-slot configuration provided intraoperative visualization of long spine segments, facilitating target localization, assessment of global spinal alignment, and evaluation of long surgical constructs. 3D-2D registration to long-length tomosynthesis reconstructions yielded a promising means of guidance and verification with accuracy exceeding that of 3D-2D registration to conventional radiographs.
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Affiliation(s)
- Xiaoxuan Zhang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore MD, United States of America
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12
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Esfandiari H, Weidert S, Kövesházi I, Anglin C, Street J, Hodgson AJ. Deep learning-based X-ray inpainting for improving spinal 2D-3D registration. Int J Med Robot 2021; 17:e2228. [PMID: 33462965 DOI: 10.1002/rcs.2228] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 11/08/2022]
Abstract
BACKGROUND Two-dimensional (2D)-3D registration is challenging in the presence of implant projections on intraoperative images, which can limit the registration capture range. Here, we investigate the use of deep-learning-based inpainting for removing implant projections from the X-rays to improve the registration performance. METHODS We trained deep-learning-based inpainting models that can fill in the implant projections on X-rays. Clinical datasets were collected to evaluate the inpainting based on six image similarity measures. The effect of X-ray inpainting on capture range of 2D-3D registration was also evaluated. RESULTS The X-ray inpainting significantly improved the similarity between the inpainted images and the ground truth. When applying inpainting before the 2D-3D registration process, we demonstrated significant recovery of the capture range by up to 85%. CONCLUSION Applying deep-learning-based inpainting on X-ray images masked by implants can markedly improve the capture range of the associated 2D-3D registration task.
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Affiliation(s)
- Hooman Esfandiari
- School of Biomedical Engineering, Surgical Technologies Lab, Centre for Hip Health and Mobility, University of British Columbia, Vancouver, British Columbia, Canada
| | - Simon Weidert
- Department for General, Trauma and Reconstructive Surgery, LMU Munich, Munich, Germany
| | - István Kövesházi
- Department for General, Trauma and Reconstructive Surgery, LMU Munich, Munich, Germany
| | - Carolyn Anglin
- Biomedical and Civil Engineering, University of Calgary, Calgary, Alberta, Canada
| | - John Street
- Combined Neurosurgical and Orthopaedic Spine Program, University of British Columbia, Vancouver, British Columbia, Canada
| | - Antony J Hodgson
- Department of Mechanical Engineering, School of Biomedical Engineering, Surgical Technologies Lab, University of British Columbia, Vancouver, British Columbia, Canada
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Thies M, Zäch JN, Gao C, Taylor R, Navab N, Maier A, Unberath M. A learning-based method for online adjustment of C-arm Cone-beam CT source trajectories for artifact avoidance. Int J Comput Assist Radiol Surg 2020; 15:1787-1796. [PMID: 32840721 PMCID: PMC7603453 DOI: 10.1007/s11548-020-02249-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 08/14/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE During spinal fusion surgery, screws are placed close to critical nerves suggesting the need for highly accurate screw placement. Verifying screw placement on high-quality tomographic imaging is essential. C-arm cone-beam CT (CBCT) provides intraoperative 3D tomographic imaging which would allow for immediate verification and, if needed, revision. However, the reconstruction quality attainable with commercial CBCT devices is insufficient, predominantly due to severe metal artifacts in the presence of pedicle screws. These artifacts arise from a mismatch between the true physics of image formation and an idealized model thereof assumed during reconstruction. Prospectively acquiring views onto anatomy that are least affected by this mismatch can, therefore, improve reconstruction quality. METHODS We propose to adjust the C-arm CBCT source trajectory during the scan to optimize reconstruction quality with respect to a certain task, i.e., verification of screw placement. Adjustments are performed on-the-fly using a convolutional neural network that regresses a quality index over all possible next views given the current X-ray image. Adjusting the CBCT trajectory to acquire the recommended views results in non-circular source orbits that avoid poor images, and thus, data inconsistencies. RESULTS We demonstrate that convolutional neural networks trained on realistically simulated data are capable of predicting quality metrics that enable scene-specific adjustments of the CBCT source trajectory. Using both realistically simulated data as well as real CBCT acquisitions of a semianthropomorphic phantom, we show that tomographic reconstructions of the resulting scene-specific CBCT acquisitions exhibit improved image quality particularly in terms of metal artifacts. CONCLUSION The proposed method is a step toward online patient-specific C-arm CBCT source trajectories that enable high-quality tomographic imaging in the operating room. Since the optimization objective is implicitly encoded in a neural network trained on large amounts of well-annotated projection images, the proposed approach overcomes the need for 3D information at run-time.
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Affiliation(s)
- Mareike Thies
- Laboratory for Computational Sensing + Robotics, Johns Hopkins University, Baltimore, MD, USA
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jan-Nico Zäch
- Computer Vision Laboratory, Eidgenössische Technische Hochschule Zürich, Zurich, Switzerland
| | - Cong Gao
- Laboratory for Computational Sensing + Robotics, Johns Hopkins University, Baltimore, MD, USA
| | - Russell Taylor
- Laboratory for Computational Sensing + Robotics, Johns Hopkins University, Baltimore, MD, USA
| | - Nassir Navab
- Laboratory for Computational Sensing + Robotics, Johns Hopkins University, Baltimore, MD, USA
| | - Andreas Maier
- Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Mathias Unberath
- Laboratory for Computational Sensing + Robotics, Johns Hopkins University, Baltimore, MD, USA.
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Intraoperative cone beam computed tomography is as reliable as conventional computed tomography for identification of pedicle screw breach in thoracolumbar spine surgery. Eur Radiol 2020; 31:2349-2356. [PMID: 33006659 PMCID: PMC7979653 DOI: 10.1007/s00330-020-07315-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 08/04/2020] [Accepted: 09/17/2020] [Indexed: 12/01/2022]
Abstract
Objectives To test the hypothesis that intraoperative cone beam computed tomography (CBCT) using the Allura augmented reality surgical navigation (ARSN) system in a dedicated hybrid operating room (OR) matches computed tomography (CT) for identification of pedicle screw breach during spine surgery. Methods Twenty patients treated with spinal fixation surgery (260 screws) underwent intraoperative CBCT as well as conventional postoperative CT scans (median 12 months after surgery) to identify and grade the degree of pedicle screw breach on both scan types, according to the Gertzbein grading scale. Blinded assessments were performed by three independent spine surgeons and the CT served as the standard of reference. Screws graded as Gertzbein 0 or 1 were considered clinically accurate while grades 2 or 3 were considered inaccurate. Sensitivity, specificity, and negative predictive value were the primary metrics of diagnostic performance. Results For this patient group, the negative predictive value of an intraoperative CBCT to rule out pedicle screw breach was 99.6% (CI 97.75–99.99%). Among 10 screws graded as inaccurate on CT, 9 were graded as such on the CBCT, giving a sensitivity of 90.0% (CI 55.5–99.75%). Among the 250 screws graded as accurate on CT, 244 were graded as such on the CBCT, giving a specificity of 97.6% (CI 94.85–99.11%). Conclusions CBCT, performed intraoperatively with the Allura ARSN system, is comparable and non-inferior to a conventional postoperative CT scan for ruling out misplaced pedicle screws in spinal deformity cases, eliminating the need for a postoperative CT. Key Points • Intraoperative cone beam computed tomography (CT) using the Allura ARSN is comparable with conventional CT for ruling out pedicle screw breaches after spinal fixation surgery. • Intraoperative cone beam computed tomography can be used to assess need for revisions of pedicle screws making routine postoperative CT scans unnecessary. • Using cone beam computed tomography, the specificity was 97.6% and the sensitivity was 90% for detecting pedicle screw breaches and the negative predictive value for ruling out a pedicle screw breach was 99.6%.
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15
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Zhao C, Herbst M, Vogt S, Ritschl L, Kappler S, Siewerdsen JH, Zbijewski W. Cone-beam imaging with tilted rotation axis: Method and performance evaluation. Med Phys 2020; 47:3305-3320. [PMID: 32340069 DOI: 10.1002/mp.14209] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 02/26/2020] [Accepted: 04/13/2020] [Indexed: 01/07/2023] Open
Abstract
PURPOSE The recently introduced robotic x-ray systems provide the flexibility to acquire cone-beam computed tomography (CBCT) data using customized, application-specific source-detector trajectories. We exploit this capability to mitigate the effects of x-ray scatter and noise in CBCT imaging of weight-bearing foot and cervical spine (C-spine) using scan orbits with a tilted rotation axis. METHODS We used an advanced CBCT simulator implementing accurate models of x-ray scatter, primary attenuation, and noise to investigate the effects of the orbital tilt angle in upright foot and C-spine imaging. The system model was parameterized using a laboratory version of a three-dimensional (3D) robotic x-ray system (Multitom RAX, Siemens Healthineers). We considered a generalized tilted axis scan configuration, where the detector remained parallel to patient's long body axis during the acquisition, but the elevation of source and detector was changing. A modified Feldkamp-Davis-Kress (FDK) algorithm was developed for reconstruction in this configuration, which departs from the FDK assumption of a detector that is perpendicular to the scan plane. The simulated foot scans involved source-detector distance (SDD) of 1386 mm, orbital tilt angles ranging 10° to 40°, and 400 views at 1 mAs/view and 0.5° increment; the C-spine scans involved -25° to -45° tilt angles, SDD of 1090 mm, and 202 views at 1.3 mAs and 1° increment The imaging performance was assessed by projection-domain measurements of the scatter-to-primary ratio (SPR) and by reconstruction-domain measurements of contrast, noise and generalized contrast-to-noise ratio (gCNR, accounting for both image noise and background nonuniformity) of the metatarsals (foot imaging) and cervical vertebrae (spine imaging). The effects of scatter correction were also compared for horizontal and tilted scans using an ideal Monte Carlo (MC)-based scatter correction and a frame-by-frame mean scatter correction. RESULTS The proposed modified FDK, involving projection resampling, mitigated streak artifacts caused by the misalignment between the filtering direction and the detector rows. For foot imaging (no grids), an optimized 20° tilted orbit reduced the maximum SPR from ~1.5 in a horizontal scan to <0.5. The gCNR of the second metatarsal was enhanced twofold compared to a horizontal orbit. For the C-spine (with vertical grids), imaging with a tilted orbit avoided highly attenuating x-ray paths through the lower cervical vertebrae and shoulders. A -35° tilted orbit yielded improved image quality and visualization of the lower cervical spine: the SPR of lower cervical vertebrae was reduced from ~10 (horizontal orbit) to <6 (tilted orbit), and the gCNR for C5-C7 increased by a factor of 2. Furthermore, tilted orbits showed potential benefits over horizontal orbits by enabling scatter correction with a simple frame-by-frame mean correction without substantial increase in noise-induced artifacts after the correction. CONCLUSIONS Tilted scan trajectories, enabled by the emerging robotic x-ray system technology, were optimized for CBCT imaging of foot and cervical spine using an advanced simulation framework. The results demonstrated the potential advantages of tilted axis orbits in mitigation of scatter artifacts and improving contrast-to-noise ratio in CBCT reconstructions.
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Affiliation(s)
- Chumin Zhao
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA
| | | | | | | | | | - Jeffrey H Siewerdsen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA.,Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Wojciech Zbijewski
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA
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Zoller G, Hahn H, Di Girolamo N. Technological Advances in Diagnostic Imaging in Exotic Pet Medicine. Vet Clin North Am Exot Anim Pract 2019; 22:397-417. [PMID: 31395322 DOI: 10.1016/j.cvex.2019.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diagnostic imaging relies on interpretation of interactions between the body tissue and various energies, such as x-rays, ultrasound, and magnetic or nuclear energies, to differentiate normal from abnormal tissues. Major technological improvements regarding emission and detection of the energetic waves, as well as reconstruction and interpretation of the images, have occurred. These advances made possible visualization of smaller structures, quantitative evaluation of functional processes, and development of unique imaging-guided procedures. This article reviews the technological advances that allowed development of cone beam computed tomography, dual-energy x-ray absorptiometry, and contrast-enhanced ultrasonography, which all could have applications in exotic pet medicine.
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Affiliation(s)
- Graham Zoller
- Exotic Pet Department, Centre Hospitalier Vétérinaire Frégis, 43 Avenue Aristide Briand, Arcueil 94110, France.
| | - Harriet Hahn
- Diagnostic Imaging Department, Centre Hospitalier Vétérinaire Frégis, 43 Avenue Aristide Briand, Arcueil 94110, France
| | - Nicola Di Girolamo
- Tai Wai Small Animal and Exotic Hospital, 69-75 Chik Shun Street, Tai Wai, Sha Tin, New Territories, Hong Kong
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Seki S, Yahara Y, Makino H, Kobayashi K, Nakano M, Hirano N, Watanabe K, Takahashi J, Kawaguchi Y, Kimura T. Differential rod contouring on thoracolumbar/lumbar curvature in patients with adolescent idiopathic scoliosis: An analysis with intraoperative acquisition of three-dimensional imaging. J Orthop Sci 2019; 24:780-786. [PMID: 30683452 DOI: 10.1016/j.jos.2019.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 11/22/2018] [Accepted: 01/06/2019] [Indexed: 11/26/2022]
Abstract
BACKGROUND Differential rod contouring (DRC) is useful for periapical vertebral derotation and decreasing rib hump in patients with thoracic adolescent idiopathic scoliosis (AIS). However, it is unknown whether DRC in the thoracolumbar/lumbar spine also contributes to derotation. We assessed the contributions of rod contouring and of DRC to the reduction of apical axial vertebral body rotation in patients with AIS with thoracolumbar/lumbar curvatures. METHODS Forty-five (Lenke type 3 or 4, 17; Lenke type 5 or 6, 28) were analyzed for the contribution of DRC to thoracolumbar/lumbar spinal derotation. Rod contouring was assessed by comparing the preinsertion x-ray with the post-operative CT images. Intraoperative C-arm fluoroscopic scans of the periapical vertebrae of the thoracolumbar/lumbar curve of the scoliosis (135 vertebrae) were taken post-rod rotation (RR) and post-DRC in all patients. Three-dimensional images were automatically reconstructed from the taken x-ray images. The angle of vertebral body rotation in these apical vertebrae was measured, and the contribution of DRC to apical vertebral body derotation and rib hump index (RHi) for lumbar prominence was analyzed. RESULTS The pre-implantation convex rod curvatures of both Lenke 3/4 and 5/6 groups decreased after surgery. The mean further reductions in vertebral rotation with post-RR DRC were 3.7° for Lenke 3/4 and 4.4° for Lenke 5/6 (P < 0.01). Both changes in apical vertebral rotation and in RHi for evaluating lumbar prominence were significantly correlated with the difference between concave and convex rod curvature in preimplantation. Vertebral derotation was significantly higher in curves with a difference >20° (P < 0.05). CONCLUSIONS DRC following rod rotation contributed substantial additional benefit to reducing vertebral rotation and decreasing lumbar prominence in thoracolumbar/lumbar scoliosis.
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Affiliation(s)
- Shoji Seki
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan.
| | - Yasuhito Yahara
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Hiroto Makino
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Kenji Kobayashi
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Masato Nakano
- Department of Orthopaedic Surgery, Takaoka City Hospital, Toyama, 933-8550, Japan
| | - Norikazu Hirano
- Department of Orthopaedic Surgery, Toyama Rosai Hospital, 662 Rokuromaru, Uozu, Toyama, 937-0042, Japan
| | - Kei Watanabe
- Department of Orthopedic Surgery, Niigata University Medicine and Dental General Hospital, 1-754 Asahimachidori, Chuo Ward, Niigata, 951-8520 Japan
| | - Jun Takahashi
- Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
| | - Yoshiharu Kawaguchi
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Tomoatsu Kimura
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
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A Novel Blind Restoration and Reconstruction Approach for CT Images Based on Sparse Representation and Hierarchical Bayesian-MAP. ALGORITHMS 2019. [DOI: 10.3390/a12080174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Computed tomography (CT) image reconstruction and restoration are very important in medical image processing, and are associated together to be an inverse problem. Image iterative reconstruction is a key tool to increase the applicability of CT imaging and reduce radiation dose. Nevertheless, traditional image iterative reconstruction methods are limited by the sampling theorem and also the blurring of projection data will propagate unhampered artifact in the reconstructed image. To overcome these problems, image restoration techniques should be developed to accurately correct a wide variety of image degrading effects in order to effectively improve image reconstruction. In this paper, a blind image restoration technique is embedded in the compressive sensing CT image reconstruction, which can result in a high-quality reconstruction image using fewer projection data. Because a small amount of data can be obtained by radiation in a shorter time, high-quality image reconstruction with less data is equivalent to reducing radiation dose. Technically, both the blurring process and the sparse representation of the sharp CT image are first modeled as a serial of parameters. The sharp CT image will be obtained from the estimated sparse representation. Then, the model parameters are estimated by a hierarchical Bayesian maximum posteriori formulation. Finally, the estimated model parameters are optimized to obtain the final image reconstruction. We demonstrate the effectiveness of the proposed method with the simulation experiments in terms of the peak signal to noise ratio (PSNR), and structural similarity index (SSIM).
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A comparative analysis of intensity-based 2D–3D registration for intraoperative use in pedicle screw insertion surgeries. Int J Comput Assist Radiol Surg 2019; 14:1725-1739. [DOI: 10.1007/s11548-019-02024-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/26/2019] [Indexed: 10/26/2022]
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Troccaz J, Dagnino G, Yang GZ. Frontiers of Medical Robotics: From Concept to Systems to Clinical Translation. Annu Rev Biomed Eng 2019; 21:193-218. [DOI: 10.1146/annurev-bioeng-060418-052502] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Medical robotics is poised to transform all aspects of medicine—from surgical intervention to targeted therapy, rehabilitation, and hospital automation. A key area is the development of robots for minimally invasive interventions. This review provides a detailed analysis of the evolution of interventional robots and discusses how the integration of imaging, sensing, and robotics can influence the patient care pathway toward precision intervention and patient-specific treatment. It outlines how closer coupling of perception, decision, and action can lead to enhanced dexterity, greater precision, and reduced invasiveness. It provides a critical analysis of some of the key interventional robot platforms developed over the years and their relative merit and intrinsic limitations. The review also presents a future outlook for robotic interventions and emerging trends in making them easier to use, lightweight, ergonomic, and intelligent, and thus smarter, safer, and more accessible for clinical use.
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Affiliation(s)
- Jocelyne Troccaz
- Université Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, F-38000 Grenoble, France
| | - Giulio Dagnino
- The Hamlyn Centre for Robotic Surgery, Imperial College London, London SW7 2AZ, United Kingdom;,
| | - Guang-Zhong Yang
- The Hamlyn Centre for Robotic Surgery, Imperial College London, London SW7 2AZ, United Kingdom;,
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Barbier O, Obert L. Distal radius fracture: The right treatment for each patient. Orthop Traumatol Surg Res 2019; 105:403-405. [PMID: 30853455 DOI: 10.1016/j.otsr.2019.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 02/20/2019] [Indexed: 02/02/2023]
Affiliation(s)
- Olivier Barbier
- Service de chirurgie orthopédique et de traumatologie de l'appareil locomoteur, cliniques universitaires Saint-Luc, avenue Hippocrate 10, 1200 Brussels, Belgium.
| | - Laurent Obert
- Service de chirurgie orthopédique, département universitaire, CHU de Besançon, 3, boulevard Alexandre-Fleming, 25000 Besançon, France
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Duchaussoy T, Lacoste M, Norberciak L, Decaudain J, Verclytte S, Budzik JF. Preoperative assessment of idiopathic scoliosis in adolescent and young adult with three-dimensional T2-weighted spin-echo MRI. Diagn Interv Imaging 2019; 100:371-379. [PMID: 30878467 DOI: 10.1016/j.diii.2019.01.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/10/2019] [Accepted: 01/21/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE To compare tridimensional (3D) T2-weighted spin-echo MRI and CT for minimal pedicle width measurements in the preoperative assessment of adolescent idiopathic scoliosis (AIS) in adolescent and young patients. MATERIALS AND METHODS A total of 22 adolescents/young patients suffering from AIS were retrospectively included. There were 18 females and 4 males with a mean age of 15.3±2.3 (SD) years (range: 11-21years). Preoperative lumbar spine MRI and CT examinations of the 22 patients were reviewed by two independent readers who measured the minimal width of 259 pedicles. Inter-reader agreement for CT and MRI was assessed using intra-class correlation coefficient (ICC). Intra-reader agreement and relative differences in measurements between MRI and CT were also assessed for each reader. RESULTS Inter-reader agreement was excellent (ICC≥0.8) for both CT and MRI. Relative differences in measurements between CT and MRI was 10.3% for reader 1 and 9.4% for reader 2. CONCLUSION 3D T2-weighted spin-echo MRI underestimates minimal pedicle width by only 9.4 - 10.3% compared to CT. 3D T2-weighted MRI appears as a valuable alternative to CT for preoperative measurements of vertebral pedicles in AIS.
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Affiliation(s)
- T Duchaussoy
- Lille Catholic Hospitals, Imaging Department, 59000 Lille, France
| | - M Lacoste
- Lille Catholic Hospitals, Imaging Department, 59000 Lille, France
| | - L Norberciak
- Lille Catholic Hospitals, Clinical Research and Innovation Department, 59000 Lille, France
| | - J Decaudain
- Lille Catholic Hospitals, Orthopedic Surgery Department, 59000 Lille, France; Lille Catholic University, 59000 Lille, France
| | - S Verclytte
- Lille Catholic Hospitals, Imaging Department, 59000 Lille, France; Lille Catholic University, 59000 Lille, France
| | - J-F Budzik
- Lille Catholic Hospitals, Imaging Department, 59000 Lille, France; Lille Catholic University, 59000 Lille, France; PMOI Physiopathology of Inflammatory Bone Diseases, EA 4490, 59000 Lille, France.
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Perdomo-Pantoja A, Ishida W, Zygourakis C, Holmes C, Iyer RR, Cottrill E, Theodore N, Witham TF, Lo SFL. Accuracy of Current Techniques for Placement of Pedicle Screws in the Spine: A Comprehensive Systematic Review and Meta-Analysis of 51,161 Screws. World Neurosurg 2019; 126:664-678.e3. [PMID: 30880208 DOI: 10.1016/j.wneu.2019.02.217] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 02/21/2019] [Accepted: 02/22/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND Pedicle screws (PSs) are routinely used for stabilization to enhance fusion in a variety of spinal diseases. Although the accuracy of different PS placement methods has been previously reported, most of these studies have been limited to 1 or 2 techniques. The purpose was to determine the current accuracy of PS placement among 4 modalities of PS insertion (freehand [FH], fluoroscopy-assisted [FA], computed tomography navigation-guided [CTNav], and robot-assisted [RA]) and analyze variables associated with screw misplacement. METHODS A systematic review was performed of peer-reviewed articles reporting PS accuracy of 1 technique from January 1990 to June 2018. Accuracy of PS placement, PS insertion technique, and pedicle breach (PB) data were collected. A meta-analysis was performed to estimate the overall pooled (OP) rates of PS accuracy as a primary outcome, stratified by screw insertion techniques. Potential determinants were analyzed via meta-regression analyses. RESULTS Seventy-eight studies with 7858 patients, 51,161 PSs, and 3614 cortical PBs were included. CTNav showed the highest PS placement accuracy compared with other techniques: OP accuracy rates were 95.5%, 93.1%, 91.5%, and 90.5%, via CTNav, FH, FA, and RA techniques, respectively. RA and CTNav were associated with the highest PS accuracy in the thoracic spine, compared with FH. CONCLUSIONS The OP data show that CTNav has the highest PS accuracy rates. Thoracic PSs were associated with lower accuracy rates; however, RA showed fewer breaches in the thoracic spine compared with FH and FA. Given the heterogeneity among studies, further standardized and comparative investigations are required to confirm our findings.
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Affiliation(s)
| | - Wataru Ishida
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Corinna Zygourakis
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Christina Holmes
- Florida A&M University-Florida State University College of Engineering, Tallahassee, Florida, USA
| | - Rajiv R Iyer
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ethan Cottrill
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Nicholas Theodore
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Timothy F Witham
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Sheng-Fu L Lo
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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Goshi A, Fukunishi S, Okahisa S, Okada T, Yoshiya S. Curved periacetabular osteotomy using intraoperative real-time 3-dimensional computed tomography with a robotic C-arm system: A case report. Medicine (Baltimore) 2018; 97:e13519. [PMID: 30508981 PMCID: PMC6283227 DOI: 10.1097/md.0000000000013519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
RATIONALE Curved periacetabular osteotomy (CPO) is a procedure with excellent surgical outcome that has been proposed for patients with development dysplasia of the hip (DDH). However, the surgical outcomes depend on the surgeon's experience and proficiency. PATIENT CONCERNS A 38-year-old female indicated she was experiencing left hip pain while walking. DIAGNOSES The patient was diagnosed with early-stage hip osteoarthritis due to DDH. INTERVENTIONS The patient underwent CPO while a 3-dimensional flat-panel C-arm (Artis zeego; Sciemens Healthcare, Forchheim, Germany) was used to confirm the real-time 3-dimensional computed tomography (CT) images during surgery. It was possible to confirm the accurate osteotomy curve using CT images twice during surgery: at the time of the ischial osteotomy and the quadrilateral surface osteotomy. OUTCOMES An ideal C-shaped osteotomy line was created as shown on the postoperative CT images. In addition, neither posterior column fracture nor intra-articular osteotomy was confirmed. LESSONS The CPO using Artis zeego resulted is a satisfactory outcome, and this is the 1st report in the world to discuss the benefits of Artis zeego in pelvic osteotomy.
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Oshina M, Oshima Y, Matsubayashi Y, Taniguchi Y, Chikuda H, Riew KD, Tanaka S. Nutrient foramen location on the laminae provides a landmark for pedicle screw entry: a cadaveric study. BMC Musculoskelet Disord 2018; 19:293. [PMID: 30115052 PMCID: PMC6097445 DOI: 10.1186/s12891-018-2218-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 08/01/2018] [Indexed: 11/22/2022] Open
Abstract
Background Nutrient foramina are often encountered around the entry point of pedicle screws. Further, while probing the pedicle for pedicle screw insertion around the nutrient foramen, bleeding from the probe insertion hole is often observed. The purpose of this study was to investigate the frequency of occurrence of nutrient foramina, the association between the nutrient foramen and pedicle, and the safety and accuracy of cervical and thoracic pedicle screw placement using the nutrient foramen as the entry point. Methods We identified the location of the nutrient foramina for the dorsal branches of the segmental artery and their anatomical association to the pedicles and bony landmarks in the vertebrae for C3–T12 in seven cadavers. We also determined the frequency with which the nutrient foramina were present in 119 cadaveric vertebrae. We identified the pedicle location, base of the superior articular facet, and lateral border of laminae with respect to the nutrient foramen. Results The overall presence of the nutrient foramina was 63% (150/238) in the specimens, with 60% (42/70) and 64% (108/168) identifiable in the cervical and thoracic vertebrae, respectively. In the cervical vertebrae, the nutrient foramen was located on the outer wall of the pedicle and was positioned between the cephalad and caudal walls. In the thoracic spine, 98% (106/108) nutrient foramina were located inside the pedicle walls. Conclusions Our study findings confirm that the location of the nutrient foramen can be used for identifying the entry point for pedicle screws. In the cervical vertebrae, the nutrient foramina are located lateral to pedicle but within the cranial and caudal margins. In the thoracic vertebrae, the nutrient foramina are located in the medial and caudal regions of the pedicle. Thus, to decrease the risk of overshoot, the entry point for thoracic pedicle screws should be positioned a few millimeters cephalad and lateral to the nutrient foramen.
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Affiliation(s)
- Masahito Oshina
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan.
| | - Yasushi Oshima
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
| | - Yoshitaka Matsubayashi
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
| | - Yuki Taniguchi
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
| | - Hirotaka Chikuda
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
| | | | - Sakae Tanaka
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
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A deep learning framework for segmentation and pose estimation of pedicle screw implants based on C-arm fluoroscopy. Int J Comput Assist Radiol Surg 2018; 13:1269-1282. [PMID: 29808466 DOI: 10.1007/s11548-018-1776-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/25/2018] [Indexed: 10/14/2022]
Abstract
PURPOSE Pedicle screw fixation is a challenging procedure with a concerning rates of reoperation. After insertion of the screws is completed, the most common intraoperative verification approach is to acquire anterior-posterior and lateral radiographic images, based on which the surgeons try to visually assess the correctness of insertion. Given the limited accuracy of the existing verification techniques, we identified the need for an accurate and automated pedicle screw assessment system that can verify the screw insertion intraoperatively. For doing so, this paper offers a framework for automatic segmentation and pose estimation of pedicle screws based on deep learning principles. METHODS Segmentation of pedicle screw X-ray projections was performed by a convolutional neural network. The network could isolate the input X-rays into three classes: screw head, screw shaft and background. Once all the screw shafts were segmented, knowledge about the spatial configuration of the acquired biplanar X-rays was used to identify the correspondence between the projections. Pose estimation was then performed to estimate the 6 degree-of-freedom pose of each screw. The performance of the proposed pose estimation method was tested on a porcine specimen. RESULTS The developed machine learning framework was capable of segmenting the screw shafts with 93% and 83% accuracy when tested on synthetic X-rays and on clinically realistic X-rays, respectively. The pose estimation accuracy of this method was shown to be [Formula: see text] and [Formula: see text] on clinically realistic X-rays. CONCLUSIONS The proposed system offers an accurate and fully automatic pedicle screw segmentation and pose assessment framework. Such a system can help to provide an intraoperative pedicle screw insertion assessment protocol with minimal interference with the existing surgical routines.
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Lee CK, Chan CYW, Gani SMA, Kwan MK. Accuracy of cannulated pedicle screw versus conventional pedicle screw for extra-pedicular screw placement in dysplastic pedicles without cancellous channel in adolescent idiopathic scoliosis: a computerized tomography (CT) analysis. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2017; 26:2951-2960. [DOI: 10.1007/s00586-017-5266-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 08/06/2017] [Accepted: 08/12/2017] [Indexed: 11/24/2022]
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Pedicle screw insertion accuracy in terms of breach and reposition using a new intraoperative cone beam computed tomography imaging technique and evaluation of the factors associated with these parameters of accuracy: a series of 695 screws. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2017. [DOI: 10.1007/s00586-017-5195-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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