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 SystemJ H Siewerdsen 1 G Gallia 2 G Hager 3 AJ Khanna 4 D Reh 5 R Taylor3J H Siewerdsen,1 G Gallia,2 G Hager,3 AJ Khanna,4 D Reh,5 R Taylor3

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 Zbijewski1

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 Bulitta7

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 PRINCIPLETO PATIENT TRIALS

PROSPECTIVE TRIAL INHEAD AND NECK SURGERY

SUMMARY AN INTEGRATED SURGICAL GUIDANCE SYSTEMObjectives: 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 SURGERYPLATFORM FOR INTEGRATED IMAGING AND NAVIGATION MULTI‐MODALITY DEFORMABLE IMAGE REGISTRATIONA mobile C‐arm prototype has been developed for high‐performance intraoperativecone‐beam CT (CBCT). The key performance characteristics include sub‐millimeter

i l l i bi d i h f i i ibili d l di i d Th

An open‐source software architecture has been developed as ageneral platform for integration of real‐time navigation with C‐

Registration techniques for fast, accurate deformable registration of preop image and planning datawith the most recent intraoperative CBCT are under development. A multi‐scale Demons algorithmd b l i i i C C id d h d d k ill d

The C‐arm prototype was translated to patient trials under IRB‐approved protocolsto evaluate image quality, surgical workflow, and the influence of image guidance

and neck surgery guidance. System performanceand translation to initial patient trials aredescribed, including integration of a novel high‐precision guidance system featuring fastd f bl 3D i i i d d

spatial resolution combined with soft‐tissue visibility and low radiation dose. Theprimary modifications to the C‐arm include: replacement of the imaging chain toinclude a high‐performance flat‐panel detector; increased x‐ray tube filtration andfield 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 imageanalysis / visualization (3D Slicer) to give a flexible framework

demonstrates sub‐voxel registration accuracy in CBCT‐guided head and neck surgery. As illustratedbelow, 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 15patients, including skull base, maxilla, and mandible surgeries illustrated below.

Intraoperative C‐Arm CBCT Rigiddeformable 3D image registration, advancedtracking, and endoscopic video‐CBCT fusion.Methods: Image quality was measured underconditions simulating head‐and‐neck surgery,

and computer control of C‐arm rotation, exposure, readout, and CBCTreconstruction. The C‐arm is being deployed in a number of applications in non‐vascular interventions, including:

• ENT / Skull Base Surgery: Guidance of tumor

Tumorresection

for rapid implementation of new guidance functionality.Application‐specific tools under development include integratedhybrid tracking configurations (Aurora, Polaris, and MicronTracker), video‐augmentation, and high‐precision fusion of

PreoperativeMR PET Planning CT

with protocols identified for patient dose lessthan diagnostic CT and dose to staff minimized(zero). The C‐arm was translated to trials in 15patients for evaluation of image quality, surgical

ablation, normal tissue avoidance; visualizationof fine detail (sinuses and middle ear) and soft‐tissues (tumors, oropharynx, base of tongue).

• Orthopaedic Surgery (spine, pelvis, and knee):

Tumormargins

video endoscopy with intraoperative CBCT . Demons algorithmDeformable

(a) CBCT obtained immediately prior to incision (esthesioneuroblastoma). (b)Planning data in CBCT showing the tumor in relation to surrounding normalperformance, and workflow. Fast deformable 3D

image registration was developed to match preopCT and planning to intraoperative CBCT.Endoscopic video‐CBCT fusion incorporates

ENHANCED SURGICAL PERFORMANCEIntegration of CBCT, tracking, and videoaugmentation; evaluation of geometric precision,accuracy, and surgical workflow.

• Thoracic / Lung Surgery: CBCT‐guided resectionThe benefit of interventional guidance has beenquantified in surgical performance studies conducted with

Planning data in CBCT showing the tumor in relation to surrounding normalanatomy. (c) Intraoperative CBCT acquired after tumor resection.

FROM THE LAB…Prototype C‐arm for CBCTImage quality optimization

tracking for robust initialization combined withhigh‐precision image‐based registration.Results: Cadaver studies demonstrate imagequality sufficient for a spectrum of surgical tasks.

0 8

1.0

tivi

ty)

of subpalpable lung nodules; augmentation ofvideo thoracoscopy / brochoscopy.

• Abdominal / Pelvic Interventions: Soft tissuevisualization (kidney, liver, and prostate) andPrototype C‐arm for high‐ Resection

q g pand without CBCT guidance. As shown below, targetexcision (tumor volumesdefined in cadaveric clivus)improved nearly a factor of 2

CBCT Guided

Image quality optimizationMinimization of radiation doseSurgical tracking systemsFast 3D image registrationEndoscopic video‐CT registration

Patient trials highlight the value of intraoperativeCBCT, particularly in skull base disease.Deformable registration demonstrated accuracysimilar to voxel size on timescales consistent with IMAGE QUALITY 0.4

0.6

0.8

Exci

sed

(Sen

sit

artifact correction (scatter and truncation).performance CBCT. Platesimproved nearly a factor of 2under C‐arm guidancecompared to a conventional(unguided) approach. Benefitswere most pronounced in

Unguided

(a) CBCT image with planned excision (radionecrotic mandible). (b)Intraoperative CBCT showing excision. (c) CBCT image (3D MIP) showing qualityand symmetry of the mandible reconstruction.TO THE OR

Endoscopic video CT registrationAn integrated navigation system

surgical workflow. Multi‐modality tracking offerssynergy of performance (50 mGyBody Sites (Lumbar) Body Sites (Lumbar) Endoscopic video‐CBCT fusion. Real‐time virtual fluoroscopy.