development and translation of a high-performance c-arm ......development and translation of a...

Development and Translation of a High-Performance C-Arm Cone-Beam CT Guidance System J H Siewerdsen 1 G Gallia 2 G Hager 3 AJ Khanna 4 D Reh 5 R Taylor 3 J H Siewerdsen, 1 G Gallia, 2 G Hager , 3 AJ Khanna, 4 D Reh, 5 R Taylor 3 D Mirota, 3 S Nithiananthan, 1 Y Otake, 3 S Reaungamornrat, 3 S Schafer, 1 JW Stayman, 1 A Uneri, 3 J Yoo, 3 W Zbijewski 1 G Bachar, 6 E Barker, 6 H Chan, 6 M Daly, 6 JC Irish, 6 G Kleinszig, 7 C Schmidgunst, 7 R Graumann, 7 C Bulitta 7 HOPKINS 1. Department of Biomedical Engineering, 2. Department of Neurosurgery, 3. Department of Computer Science, 4. Department of Orthopaedic Surgery, 5. Department of Otolaryngology – Head and Neck Surgery, Johns Hopkins University (Baltimore MD) 6. University Health Network (Toronto ON), 7. Siemens Healthcare (SP Division, Erlangen Germany) FROM PROOF OF PRINCIPLE TO PATIENT TRIALS PROSPECTIVE TRIAL IN HEAD AND NECK SURGERY SUMMARY AN INTEGRATED SURGICAL GUIDANCE SYSTEM Objectives: A mobile C‐arm for cone‐beam CT (CBCT) providing sub‐mm resolution and soft‐ tissue visibility is under development for head d k id S t f TO PATIENT TRIALS HEAD AND NECK SURGERY PLATFORM FOR INTEGRATED IMAGING AND NAVIGATION MULTI‐MODALITY DEFORMABLE IMAGE REGISTRATION A mobile C‐arm prototype has been developed for high‐performance intraoperative cone‐beam CT (CBCT). The key performance characteristics include sub‐millimeter il l i bi d ih f i i ibili d l di i d Th An open‐source software architecture has been developed as a general platform for integration of real‐time navigation with C‐ Registration techniques for fast, accurate deformable registration of preop image and planning data with the most recent intraoperative CBCT are under development. A multi‐scale Demons algorithm d b l i i i CC id d h d d k ill d The C‐arm prototype was translated to patient trials under IRB‐approved protocols to evaluate image quality, surgical workflow, and the influence of image guidance and neck surgery guidance. System performance and translation to initial patient trials are described, including integration of a novel high‐ precision guidance system featuring fast df bl 3D i i i d d spatial resolution combined with soft‐tissue visibility and low radiation dose. The primary modifications to the C‐arm include: replacement of the imaging chain to include a high‐performance flat‐panel detector; increased x‐ray tube filtration and field of view; motorization of the C‐arm orbit; reproducible geometric calibration; arm cone‐beam CT, rigid and deformable registration, and multi‐ modality visualization. The modular software combines open‐ source libraries for surgical tracking (Hopkins CISST) and image analysis / visualization (3D Slicer) to give a flexible framework demonstrates sub‐voxel registration accuracy in CBCT‐guided head and neck surgery. As illustrated below, rigid registration fails to correct the complexity of deformations imparted in skull base surery. on surgical decision making and surgical product. An initial pilot study involved 15 patients, including skull base, maxilla, and mandible surgeries illustrated below. Intraoperative C‐Arm CBCT Rigid def ormable 3D image registration, advanced tracking, and endoscopic video‐CBCT fusion. Methods: Image quality was measured under conditions simulating head‐and‐neck surgery, and computer control of C‐arm rotation, exposure, readout, and CBCT reconstruction. The C‐arm is being deployed in a number of applications in non‐ vascular interventions, including: • ENT / Skull Base Surgery : Guidance of tumor Tumor resection for rapid implementation of new guidance functionality. Application‐specific tools under development include integrated hybrid tracking configurations (Aurora, Polaris, and Micron Tracker), video‐augmentation, and high‐precision fusion of Preoperative MR PET Planning CT with protocols identified for patient dose less than diagnostic CT and dose to staff minimized (zero). The C‐arm was translated to trials in 15 patients for evaluation of image quality, surgical ablation, normal tissue avoidance; visualization of fine detail (sinuses and middle ear) and soft‐ tissues (tumors, oropharynx, base of tongue). • Orthopaedic Surgery (spine, pelvis, and knee) : Tumor margins video endoscopy with intraoperative CBCT . Demons algorithm Deformable (a) CBCT obtained immediately prior to incision (esthesioneuroblastoma). (b) Planning data in CBCT showing the tumor in relation to surrounding normal performance, and workflow . Fast deformable 3D image registration was developed to match preop CT and planning to intraoperative CBCT. Endoscopic video‐CBCT fusion incorporates ENHANCED SURGICAL PERFORMANCE Integration of CBCT, tracking, and video augmentation; evaluation of geometric precision, accuracy, and surgical workflow. • Thoracic / Lung Surgery : CBCT‐guided resection The benefit of interventional guidance has been quantified in surgical performance studies conducted with Planning data in CBCT showing the tumor in relation to surrounding normal anatomy. (c) Intraoperative CBCT acquired after tumor resection. FROM THE LAB… Prototype C‐arm for CBCT Image quality optimization tracking for robust initialization combined with high‐precision image‐based registration. Results: Cadaver studies demonstrate image quality sufficient for a spectrum of surgical tasks. 0 8 1.0 tivity) of subpalpable lung nodules; augmentation of video thoracoscopy / brochoscopy. • Abdominal / Pelvic Interventions : Soft tissue visualization (kidney, liver, and prostate) and Prototype C‐arm for high‐ Resection and without CBCT guidance. As shown below, target excision (tumor volumes defined in cadaveric clivus) improved nearly a factor of 2 CBCT Guided Image quality optimization Minimization of radiation dose Surgical tracking systems Fast 3D image registration Endoscopic video‐CT registration Patient trials highlight the value of intraoperative CBCT, particularly in skull base disease. Deformable registration demonstrated accuracy similar to voxel size on timescales consistent with IMAGE QUALITY 0.4 0.6 0.8 Excised (Sensit artifact correction (scatter and truncation). performance CBCT. Plates improved nearly a factor of 2 under C‐arm guidance compared to a conventional (unguided) approach. Benefits were most pronounced in Unguided (a) CBCT image with planned excision (radionecrotic mandible). (b) Intraoperative CBCT showing excision. (c) CBCT image (3D MIP) showing quality and symmetry of the mandible reconstruction. TO THE OR Endoscopic video CT registration An integrated navigation system surgical workflow. Multi‐modality tracking offers synergy of performance (<1 mm precision) and robustness (e.g., hybrid EM‐video easing field distortion and line‐of‐sight limitations and DISCUSSION & CONCLUSIONS 0.0 0.2 0.0 0.2 0.4 0.6 0.8 Target E Normal Excised (1‐Specificity) 1.0 The C‐arm prototype represents a significant advance over previous 3D imaging platforms, offering sub‐mm spatial resolution and soft‐tissue visibility through Early research focused on soft‐tissue image quality integration of novel navigation were most pronounced in challenging excision tasks in proximity to critical structures (e.g., clival tumor excision adjacent to the carotid incorporation of a high‐quality flat panel detector accurate … TO THE OR. Prospective trial in 15 patients Sinus surgery Maxillectomy Facial reconstruction offering real‐time video augmentation). Advanced endoscopic video‐CBCT fusion gives sub‐mm precision with image‐based matching. Conclusion: A prototypeC‐arm for CBCT offers to AUGMENTATION OF ENDOSCOPIC VIDEO ADVANCED TRACKING AND VISUALIZATION TOOLS Early research focused on soft tissue image quality , integration of novel navigation systems, quantitative evaluation of surgical performance, and development of an advanced clinical prototype C‐arm. New 3D image reconstruction methods offer the potential for further image quality improvement and dose reduction. Multi‐mode tracking registration and visualization applies a flexible software architecture for adjacent to the carotid arteries and optic nerves). flat‐panel detector , accurate geometric calibration, and advanced 3D reconstruction. Task‐ specific scan protocols are employed to minimize dose Facial reconstruction Skull base tumor surgery extend the functionality of image guidance to a broad spectrum of tasks in head and neck / skull base surgery. Streamlined integration of navigation subsystems is critical to workflow and AUGMENTATION OF ENDOSCOPIC VIDEO ADVANCED TRACKING AND VISUALIZATION TOOLS High‐precision fusion of image and planning data directly within the endoscopic scene is possible by combining real‐time tracking of the endoscope with advanced computer vision techniques (viz., 3D Novel surgical tracking systems, including infrared , video, and electromagnetic trackers are configured in single or multi‐modality systems appropriate to the surgical task. Such systems allow not only tracking, registration, and visualization applies a flexible software architecture for streamlined integration and adaptation according to clinical requirements. structure from motion). As illustrated at left, this allows the Core to the research is the quantitative evaluation of benefits to surgical performance achieved through CBCT image guidance Ongoing research in pre clinical studies employed to minimize dose – “Fast” scans for visualization of bony structures and “Hi‐Q” scans for soft‐tissue visibility – allowing repeat intraoperative imaging C‐Spine Cochlea realizing the promise of advanced guidance techniques. The work provides a foundation for an advanced clinical prototype, currently underway . real‐time tracking in preoperative images but also within the most up‐to‐date CBCT image. The systems also permit novel video augmentation approaches, such as video‐augmented spine surgery at right showing real‐time video fused with preop CT, intraop CBCT, structure from motion). As illustrated at left, this allows the surgeon to visualize not only his/her position with respect to CBCT (orthogonal planes) but also real‐time fusion of image and planning data within the endoscopic view. The example at left shows the carotid arteries (pink) and pituitary gland (orange) image guidance. Ongoing research in pre‐clinical studies and clinical trials evaluates the benefits to surgical product, workflow, and patient safety. An advanced clinical prototype leverages the knowledge gained from a decade of research in C arm CBCT toward the repeat intraoperative imaging with total dose less than a single diagnostic CT. Example Imaging Protocol S 0 (Hi Q) 10 G Facial Nerve Middle Ear Vid t ti underway . CONTACT: at right showing real time video fused with preop CT, intraop CBCT, tracking data, and surgical planning data (target volume in red). Combining such systems with GPU‐accelerated image reconstruction and registration techniques allows new capabilities such as real‐time DRR (“virtual fluoroscopy ”) in which x‐ray projections are computed shows the carotid arteries (pink) and pituitary gland (orange) registered in real‐time to endoscopic video, providing a boost to visualization and surgical confidence in proximity to critical anatomy. Because the preop image and planning data are deformably registered to the most up‐to‐date CBCT image decade of research in C‐arm CBCT toward the development of a new C‐arm designed specifically for high‐performance intraoperative 3D image guidance. Scan 0 (Hi‐Q) 10 mGy 3D Fast 3 3D Fast 3 3D Hi‐Q 10 Middle Ear Video augmentation. CONTACT: Jeffrey H. Siewerdsen, Ph.D. Johns Hopkins University [email protected] jh d /i JOHNS HOPKINS UNIVERSITY The I-STAR Lab Imaging for Surgery,Therapy, and Radiology DRR ( virtual fluoroscopy ) in which x ray projections are computed in real‐time according to the pose of the C‐arm or a handheld tool. Such visualization capabilities promise to enhance surgical workflow, reduce radiation dose, and improve patient safety. deformably registered to the most up to date CBCT image, many of the limitations of conventional guidance are minimized, expanding the applicability of high‐precision guidance to a broad spectrum of head and neck pathologies. 3D Fast 3 3D Fast 3 Scan N (Hi‐Q) 10 TOTAL 42 mGy Bd Si (L b ) Bd Si (L b ) www.jhu.edu/istar SCHOOLS OF ENGINEERING AND MEDICINE (Typ. Diag. CT) >50 mGy Body Sites (Lumbar) Body Sites (Lumbar) Endoscopic video‐CBCT fusion. Real‐time virtual fluoroscopy.

development and translation of a high-performance c-arm ......development and translation of a...

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