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Cui H, Zhan H, Yuan X, Yang Y. A rotating beam-blocker method for cone beam CT scatter correction. Med Phys 2024. [PMID: 38984799 DOI: 10.1002/mp.17274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 06/03/2024] [Accepted: 06/09/2024] [Indexed: 07/11/2024] Open
Abstract
BACKGROUND Cone beam CT (CBCT) is widely utilized in clinics. However, the scatter artifact degrades the CBCT image quality, hampering the expansion of CBCT applications. Recently, beam-blocker methods have been used for CBCT scatter correction and proved their high cost-effectiveness. PURPOSE A rotating beam-blocker (RBB) method for CBCT scatter correction was proposed to complete scatter correction and image reconstruction within a single scan in both full- and half-fan scan scenarios. METHODS The RBB consisted of two open regions and two blocked regions, and was designed as a centrosymmetric structure. The open and blocked projections could be alternatively obtained within one single rotation. The open projections were corrected with the scatter signal calculated from the blocked projections, and then used to reconstruct the 3D image via the Feldkamp-Davis-Kress algorithm. The performance of the RBB method was evaluated on head and pelvis phantoms in scenarios with and without a bowtie filter. The images obtained from nine repeated scans in each scenario were used to calculate the evaluation metrics including the CT number error, spatial nonuniformity (SNU) and contrast-to-noise ratio (CNR). RESULTS For the head phantom, the CT number error was decreased to <5 after scatter correction from >200 HU before correction when scanned without a bowtie filter, and to <4 from >160 HU when scanned with a full bowtie filter. For the pelvis phantom, the CT number error was reduced to <12 after scatter correction from >250 HU before correction when scanned without a bowtie filter, and to <10 from >190 HU when scanned with a half bowtie filter. After scatter correction, the uniformity and contrast were both improved, resulting in an SNU of >79% decrease and CNR of >2 times increase, respectively. CONCLUSIONS High-quality CBCT images could be obtained in a single scan after using the proposed RBB method for scatter correction, enabling more accurate image guidance for surgery and radiation therapy applications. With almost no time delay between the successive open and blocked projections, the RBB method could eliminate the motion-induced anatomical mismatches between the corresponding open and blocked projections and could find particular usefulness in thoracic and abdominal imaging.
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Affiliation(s)
- Hehe Cui
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
- Hubei Key Laboratory of Precision Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Haolin Zhan
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Xiaogang Yuan
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Yidong Yang
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- Department of Radiation Oncology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- Ion Medical Research Institute, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
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Tanahashi Y, Kubota K, Nomura T, Ikeda T, Kutsuna M, Funayama S, Kobayashi T, Ozaki K, Ichikawa S, Goshima S. Improved vascular depiction and image quality through deep learning reconstruction of CT hepatic arteriography during transcatheter arterial chemoembolization. Jpn J Radiol 2024:10.1007/s11604-024-01614-3. [PMID: 38888853 DOI: 10.1007/s11604-024-01614-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/04/2024] [Indexed: 06/20/2024]
Abstract
PURPOSE To evaluate the effect of deep learning reconstruction (DLR) on vascular depiction, tumor enhancement, and image quality of computed tomography hepatic arteriography (CTHA) images acquired during transcatheter arterial chemoembolization (TACE). METHODS Institutional review board approval was obtained. Twenty-seven patients (18 men and 9 women, mean age, 75.7 years) who underwent CTHA immediately before TACE were enrolled. All images were reconstructed using three reconstruction algorithms: hybrid-iterative reconstruction (hybrid-IR), DLR with mild strength (DLR-M), and DLR with strong strength (DLR-S). Vascular depiction, tumor enhancement, feeder visualization, and image quality of CTHA were quantitatively and qualitatively assessed by two radiologists and compared between the three reconstruction algorithms. RESULTS The mean signal-to-noise ratios (SNR) of sub-segmental arteries and sub-sub-segmental arteries, and the contrast-to-noise ratio (CNR) of tumors, were significantly higher on DLR-S than on DLR-M and hybrid-IR (P < 0.001). The mean qualitative score for sharpness of sub-segmental and sub-sub-segmental arteries was significantly better on DLR-S than on DLR-M and hybrid-IR (P < 0.001). There was no significant difference in the feeder artery detection rate of automated feeder artery detection software among three reconstruction algorithms (P = 0.102). The contrast, continuity, and confidence level of feeder artery detection was significantly better on DLR-S than on DLR-M (P = 0.013, 0.005, and 0.001) and hybrid-IR (P < 0.001, P = 0.002, and P < 0.001). The weighted kappa values between two readers for qualitative scores of feeder artery visualization were 0.807-0.874. The mean qualitative scores for sharpness, granulation, and diagnostic acceptability of CTHA were better on DLR-S than on DLR-M and hybrid-IR (P < 0.001). CONCLUSIONS DLR significantly improved the SNR of small hepatic arteries, the CNR of tumor, and feeder artery visualization on CTHA images. DLR-S seems to be better suited to routine CTHA in TACE than does hybrid-IR.
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Affiliation(s)
- Yukichi Tanahashi
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan.
| | - Koh Kubota
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Takayuki Nomura
- Radiology Service, Hamamatsu University Hospital, Hamamatsu City, Shizuoka, Japan
| | - Takanobu Ikeda
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Masaya Kutsuna
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Satoshi Funayama
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Tatsunori Kobayashi
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Kumi Ozaki
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Shintaro Ichikawa
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Satoshi Goshima
- Department of Radiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu City, Shizuoka, 431-3192, Japan
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Schwendner M, Liang R, Butenschön VM, Meyer B, Ille S, Krieg SM. The one-stop-shop approach: Navigating lumbar 360-degree instrumentation in a single position. Front Surg 2023; 10:1152316. [PMID: 37009623 PMCID: PMC10060549 DOI: 10.3389/fsurg.2023.1152316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
ObjectiveTreatment strategies of patients suffering from pyogenic spondylodiscitis are a controverse topic. Percutaneous dorsal instrumentation followed by surgical debridement and fusion of the infectious vertebral disc spaces is a common approach for surgical treatment. Technical advances enable spinal navigation for dorsal and lateral instrumentation. This report investigates combined navigated dorsal and lateral instrumentation in a single surgery and positioning for lumbar spondylodiscitis in a pilot series.MethodsPatients diagnosed with 1- or 2-level discitis were prospectively enrolled. To enable posterior navigated pedicle screw placement and lateral interbody fusion (LLIF) patients were positioned semi-prone in 45-degree fashion. For spinal referencing, a registration array was attached to the pelvic or spinal process. 3D scans were acquired intraoperatively for registration and implant control.Results27 patients suffering from 1- or 2-level spondylodiscitis with a median ASA of 3 (1–4) and a mean BMI of 27.9 ± 4.9 kg/m2 were included. Mean duration of surgery was 146 ± 49 min. Mean blood loss was 367 ± 307 ml. A median of 4 (4–8) pedicle screws were placed for dorsal percutaneous instrumentation with an intraoperative revision rate of 4.0%. LLIF was performed on 31 levels with an intraoperative cage revision rate of 9.7%.ConclusionsNavigated lumbar dorsal and lateral instrumentation in a single operation and positioning is feasible and safe. It enables rapid 360-degree instrumentation in these critically ill patients and potentially reduces overall intraoperative radiation exposure for patient and staff. Compared to purely dorsal approaches it allows for optimal discectomy and fusion while overall incisions and wound size are minimized. Compared to prone LLIF procedures, semi-prone in 45-degree positioning allows for a steep learning curve due to minor changes of familiar anatomy.
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Affiliation(s)
- Maximilian Schwendner
- Department of Neurosurgery, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
- TUM Neuroimaging Center, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
| | - Raimunde Liang
- Department of Neurosurgery, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
| | - Vicki M. Butenschön
- Department of Neurosurgery, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
| | - Bernhard Meyer
- Department of Neurosurgery, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
| | - Sebastian Ille
- Department of Neurosurgery, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
- TUM Neuroimaging Center, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
| | - Sandro M. Krieg
- Department of Neurosurgery, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
- TUM Neuroimaging Center, School of Medicine, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany
- Correspondence: Sandro M. Krieg
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Croci DM, Nguyen S, Streitmatter SW, Sherrod BA, Hardy J, Cole KL, Gamblin AS, Bisson EF, Mazur MD, Dailey AT. O-Arm Accuracy and Radiation Exposure in Adult Deformity Surgery. World Neurosurg 2023; 171:e440-e446. [PMID: 36528322 DOI: 10.1016/j.wneu.2022.12.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022]
Abstract
OBJECTIVE In long thoracolumbar deformity surgery, accurate screw positioning is critical for spinal stability. We assessed pedicle and pelvic screw accuracy and radiation exposure in patients undergoing long thoracolumbar deformity fusion surgery (≥4 levels) involving 3-dimensional fluoroscopy (O-Arm/Stealth) navigation. METHODS In this retrospective single-center cohort study, all patients aged >18 years who underwent fusion in 2016-2018 were reviewed. O-Arm images were assessed for screw accuracy. Effective radiation doses were calculated. The primary outcome was pedicle screw accuracy (Heary grade). Secondary outcomes were pelvic fixation screw accuracy, radiation exposure, and screw-related perioperative and postoperative complications or revision surgery within 3 years. RESULTS Of 1477 pedicle screws placed in 91 patients (mean 16.41 ± 5.6 screws/patient), 1208 pedicle screws (81.8%) could be evaluated by 3-dimensional imaging after placement. Heary Grade I placement was achieved in 1150 screws (95.2%), Grade II in 47 (3.9%), Grade III in 10 (0.82%), Grade IV in 1 (0.08%), and Grade V in 0; Grade III-V were replaced intraoperatively. One of 60 (1.6%) sacroiliac screws placed showed medial cortical breach and was replaced. The average O-Arm-related effective dose was 29.54 ± 14.29 mSv and effective dose/spin was 8.25 ± 2.65 mSv. No postoperative neurological worsening, vascular injuries, or revision surgeries for screw misplacement were recorded. CONCLUSIONS With effective radiation doses similar to those in interventional neuroendovascular procedures, the use of O-Arm in multilevel complex deformity surgery resulted in high screw accuracy, no need for surgical revision because of screw malposition, less additional imaging, and no radiation exposure for the surgical team.
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Affiliation(s)
- Davide Marco Croci
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA
| | - Sarah Nguyen
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA
| | - Seth W Streitmatter
- Medical Imaging Physics and Radiation Safety, Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Brandon A Sherrod
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA
| | - Jeremy Hardy
- School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Kyril L Cole
- School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Austin S Gamblin
- School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Erica F Bisson
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA
| | - Marcus D Mazur
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA
| | - Andrew T Dailey
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA.
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A minimally invasive tubular retractor-assisted retropleural approach for thoracic disc herniations - case series and technical note. Acta Neurochir (Wien) 2023; 165:771-777. [PMID: 36652013 PMCID: PMC10006021 DOI: 10.1007/s00701-022-05470-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/21/2022] [Indexed: 01/19/2023]
Abstract
PURPOSE Thoracic disc herniations are uncommon and carry a high risk for neurological deterioration. Traditional surgical approaches include thoracotomy, costotransversectomy or posterior approaches with considerable morbidity. In this technical note with case series, we describe a minimally invasive tubular retractor-assisted retropleural approach for simple and less invasive microsurgical exploration of thoracic disc herniations from a lateral angle. METHODS Surgical technique consisted of partial rib resection and retropleural dissection followed by the placement of a tubular retractor (METRx Tubes, Medtronic) for an anterior-lateral exposure of the disc and neuroforamen. Epidemiological, clinical and surgical patient data were acquired. RESULTS Between 2017 and 2020, six patients were surgically treated using the minimally invasive tubular retractor-assisted retropleural approach. Microsurgical exposure of the disc and neural structures was achieved from a lateral direction without requiring thoracotomy or lung deflation. Control imaging confirmed resection in all cases without relevant residuum. As postoperative complications, one dural injury and one postoperative pneumothorax occured. No neurologic deterioration or recurrence occurred during a median follow-up of 3 months. CONCLUSION The described tubular retractor-assisted retropleural exposure serves as a feasible minimally invasive microsurgical approach to the anterior-lateral thoracic spine.
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Karius A, Schweizer C, Strnad V, Lotter M, Kreppner S, Lamrani A, Fietkau R, Bert C. Seed-displacements in the immediate post-implant phase in permanent prostate brachytherapy. Radiother Oncol 2023; 183:109590. [PMID: 36858202 DOI: 10.1016/j.radonc.2023.109590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/03/2023]
Abstract
PURPOSE To investigate differences in seed-displacements between the immediate post-implant phase (day 0-1) and the time to post-plan computed tomography (CT) (day 1-30) in seed prostate brachytherapy. MATERIALS AND METHODS Seed positions were identified on the intra-operatively created ultrasound-based treatment plan (day 0) and CT scans of day 1 and 30 for 33 patients. The day 1 (30) seed arrangement was registered onto the day 0 (1) arrangement using a seed-only approach. Based on a 1:1 assignment of seeds via the Kuhn-Munkres algorithm, seed-displacements were analyzed. Displacements were evaluated depending on strand-length and anatomical implant location. Resulting dosimetric effects were calculated. RESULTS Seed-displacements in the immediate post-implant phase (median displacements: 3.8 ± 3.6 mm) were stronger than in the time to post-plan CT (2.1 ± 2.6 mm) and enhanced along the superior-inferior direction. From day 0 to 1, strands containing one (7.3 ± 5.4 mm) or two (8.1 ± 5.8 mm) seeds showed larger displacements than strands of higher lengths (up to 4.2 ± 7.0 mm), whereas no length-dependency was found to day 30. Seeds implanted in base and apex tended to move towards the prostate midzone during both time periods. D90 (dose that 90% of prostate receives) was with variations of 2 ± 15 Gy more stable from day 1 to 30 than in the immediate post-implant phase (-18 ± 11 Gy). CONCLUSION Seed-displacements in the immediate post-implant phase was enhanced compared to day 1-30. This may result from uncertainties in the gold-standard ultrasound-based treatment planning and implantation. Adaptive implantation workflows appear useful for ensuring high implant stability from the beginning.
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Affiliation(s)
- Andre Karius
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany.
| | - Claudia Schweizer
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Vratislav Strnad
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Michael Lotter
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Stephan Kreppner
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Allison Lamrani
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
| | - Christoph Bert
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstraße 27, 91054 Erlangen, Germany; Comprehensive Cancer Center Erlangen-EMN (CCC ER-EMN), Erlangen, Germany
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[Application of navigation in the fractured spine]. OPERATIVE ORTHOPADIE UND TRAUMATOLOGIE 2023; 35:29-36. [PMID: 36441223 DOI: 10.1007/s00064-022-00790-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/21/2022] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Computer navigation is used in patients with spine fractures to optimize the accuracy of pedicle screws and thereby reduce intra- and postoperative complications, such as injuries to vessels, nerves and accompanying structures. In addition, the ideal screw length and diameter for each pedicle can be detected to ensure optimal stability. INDICATIONS Intraoperative navigation is suitable for the treatment of spine fractures, which require dorsal stabilization or fusion. It is primarily used for dorsal procedures ranging from the cervical to lumbar/sacral spine. CONTRAINDICATIONS Computer navigation relies on rigid fixation of the dynamic reference base (DRB) at the spinous process. Failure of DRB fixation is the major contraindication for navigation in the spine. SURGICAL TECHNIQUE After acquisition of an intraoperative three-dimensional (3D) scan, a digital relation between the anatomy and the 3D scan is established with the navigation system and its infrared camera. Pedicle screws are planned percutaneously with a calibrated pointer. In the next step K‑wires (or screws) are implanted after the pedicles are drilled with a calibrated drill guide. After implantation, an additional 3D scan is performed to verify accurate K‑wire placement. POSTOPERATIVE MANAGEMENT Postoperative management does not differ compared to nonnavigated procedures. RESULTS Intraoperative navigation in combination with modern imaging systems leads to very high accuracy for pedicle screws. Immediate intraoperative control of K‑wires as well as screws and fracture reduction can avoid revision surgery. Image guidance can reduce radiation exposure for the surgical team.
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Navigation accuracy and assessability of carbon fiber-reinforced PEEK instrumentation with multimodal intraoperative imaging in spinal oncology. Sci Rep 2022; 12:15816. [PMID: 36138117 PMCID: PMC9500029 DOI: 10.1038/s41598-022-20222-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/09/2022] [Indexed: 12/03/2022] Open
Abstract
Radiolucent carbon-fiber reinforced PEEK (CFRP) implants have helped improve oncological follow-up and radiation therapy. Here, we investigated the performance of 3D intraoperative imaging and navigation systems for instrumentation and precision assessment of CFRP pedicle screws across the thoraco-lumbar spine. Thirty-three patients with spinal tumors underwent navigated CFRP instrumentation with intraoperative CT (iCT), robotic cone-beam CT (rCBCT) or cone-beam CT (CBCT) imaging. Two different navigation systems were used for iCT-/rCBCT- and CBCT-based navigation. Demographic, clinical and outcome data was assessed. Four blinded observers rated image quality, assessability and accuracy of CFRP pedicle screws. Inter-observer reliability was determined with Fleiss` Kappa analysis. Between 2018 and 2021, 243 CFRP screws were implanted (iCT:93, rCBCT: 99, CBCT: 51), of which 13 were non-assessable (iCT: 1, rCBCT: 9, CBCT: 3; *p = 0.0475; iCT vs. rCBCT). Navigation accuracy was highest using iCT (74%), followed by rCBCT (69%) and CBCT (49%) (*p = 0.0064; iCT vs. CBCT and rCBCT vs. CBCT). All observers rated iCT image quality higher than rCBCT/CBCT image quality (*p < 0.01) but relevant pedicle breaches were reliably identified with substantial agreement between all observers regardless of the imaging modality. Navigation accuracy for CFRP pedicle screws was considerably lower than expected from reports on titanium implants and CT may be best for reliable assessment of CFRP materials.
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CT-Navigated Spinal Instrumentations-Three-Dimensional Evaluation of Screw Placement Accuracy in Relation to a Screw Trajectory Plan. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58091200. [PMID: 36143877 PMCID: PMC9506171 DOI: 10.3390/medicina58091200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/25/2022] [Accepted: 08/27/2022] [Indexed: 11/17/2022]
Abstract
Background and Objectives: In the literature, spinal navigation and robot-assisted surgery improved screw placement accuracy, but the majority of studies only qualitatively report on screw positioning within the vertebra. We sought to evaluate screw placement accuracy in relation to a preoperative trajectory plan by three-dimensional quantification to elucidate technical benefits of navigation for lumbar pedicle screws. Materials and Methods: In 27 CT-navigated instrumentations for degenerative disease, a dedicated intraoperative 3D-trajectory plan was created for all screws. Final screw positions were defined on postoperative CT. Trajectory plans and final screw positions were co-registered and quantitatively compared computing minimal absolute differences (MAD) of screw head and tip points (mm) and screw axis (degree) in 3D-space, respectively. Differences were evaluated with consideration of the navigation target registration error. Clinical acceptability of screws was evaluated using the Gertzbein−Robbins (GR) classification. Results: Data included 140 screws covering levels L1-S1. While screw placement was clinically acceptable in all cases (GR grade A and B in 112 (80%) and 28 (20%) cases, respectively), implanted screws showed considerable deviation compared to the trajectory plan: Mean axis deviation was 6.3° ± 3.6°, screw head and tip points showed mean MAD of 5.2 ± 2.4 mm and 5.5 ± 2.7 mm, respectively. Deviations significantly exceeded the mean navigation registration error of 0.87 ± 0.22 mm (p < 0.001). Conclusions: Screw placement was clinically acceptable in all screws after navigated placement but nevertheless, considerable deviation in implanted screws was noted compared to the initial trajectory plan. Our data provides a 3D-quantitative benchmark for screw accuracy achievable by CT-navigation in routine spine surgery and suggests a framework for objective comparison of screw outcome after navigated or robot-assisted procedures. Factors contributing to screw deviations should be considered to assure optimal surgical results when applying navigation for spinal instrumentation.
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