© NIH National Center for Image-Guided Therapy, March 2008 IGT Clinical Workshop Non-Rigid, Multi-Modality Image Registration for Thermal Ablation: Non-Rigid,

© NIH National Center for Image-Guided Therapy, March 2008 IGT Clinical Workshop

Non-Rigid, Multi-Modality Non-Rigid, Multi-Modality Image Registration Image Registration

for Thermal Ablation:for Thermal Ablation: Pre-Procedural MRI to Intra-

Procedural CT for Tumor Targeting

N. Archip, P.R. MorrisonBrigham & Women’s Hospital


WORKSHOP OBJECTIVE

To illustrate the need for image registration to address limitations in targeting a tumor during a tumor ablation procedure.


ABLATION

MRI

CT

US

BONE/SOFT TISSUE

KIDNEY/ADRENAL

LIVER

LUNG

GUIDANCEMODALITY

ABLATIVEAGENT

TREATMENTSITE

Acad Radiol 2005;12:1100-109

CRYOTHERAPY

RFA

ETOH


• RFA: RADIOFREQUENCY ABLATION

• CRYO: CRYOTHERAPY

• LITT, ILT: LASER ABLATION

• MWA: MICROWAVE ABLATION

• HIFU, FUS: FOCUSED ULTRASOUND

THERMAL ABLATION

Images courtesy Cross-sectional Interventional Radiology, Brigham & Women’s Hospital, Boston, MA


CLINICAL SYSTEMS

• RF generator & electrode• CRYO unit & probe • LASER & optical fiber • MW generator & antenna

PERCUTANEOUS ABLATION



CLINICAL ENIRONMENT



DEFINEPLANTARGETMONITORCONTROLASSESS

IMAGE-GUIDANCE

Radiology 2005; 236:716-724


• MRI-guided cryotherapy of a 3.4cm liver metastasis• Sagittal T2-weighted fse imaging used to place

cryoprobes (arrowheads) into the tumor (arrow)• Iceballs form around each probe; these coalesce• Tumor is eclipsed

DYNAMIC PROCESSES

Acad Radiol 2005;12:1100-109


3-D PROCESS

Pre

Intra

Post

Post in 3-D

Modified from AJR 2004;183:707–712


RFA Post-RFA MRI Coronal

CT-GUIDED RFA IN LUNG

TARGET



CE CT PRE CE MRI POSTCT INTRA

PLAN – TX - ASSESS

CT-GUIDED RFA IN SOFT TISSUE



Non-Rigid, Multi-Modality Non-Rigid, Multi-Modality Image Registration Image Registration

for Thermal Ablation:for Thermal Ablation: Pre-Procedural MRI to Intra-

Procedural CT for Tumor Targeting


CLINICAL NEED – Example 1

Recent BWH ablation case: Pre-Proc MRI vs Intra-CT47yo M, 3cm liver metastasis of sq cell ca in Seg 8; lung & vessels nearby

Pre-ProcedureCE MRI at 1.5T

Intra-ProcedureNon-Enhanced CT

Procedure 071107Images courtesy Cross-sectional Interventional Radiology, Brigham & Women’s Hospital, Boston, MA


CLINICAL NEED – Example 2

Recent BWH Ablation Case: PreProc MRI vs Intra-CT69yo M, 7cm liver metastasis of colon cancer; look for coverage; GB & colon nearby

Pre-ProcedureCE MRI at 1.5T

Intra-ProcedureNon-Enhanced CT

Procedure 080304Images courtesy Cross-sectional Interventional Radiology, Brigham & Women’s Hospital, Boston, MA


Dx comes from one imaging modality … Tx takes place under another.

CLINICAL NEED


SOLUTION: REGISTRATION

Bring Pre-procedural diagnostic MRI into the Intra-procedural

interventional space


PRE-PROCEDURAL CE MRI

051021 CEMRI PreTx Ser08 i270

Example:Registered Data

--MRI Pre

BWH Ablation Case50yo M, 2cm primary liver tumor (HCC) in segment 2


© NIH National Center for Image-Guided Therapy, March 2008 IGT Clinical Workshop 051220 CT PreTx Ser04 i21

INTRA-PROCEDURAL CT


--CT Intra



RFA ELECTRODE PLACED


--CT Intra



REGISTERED IMAGES


--Merged MRI & CT



WORK FLOW

Pre-Proc MRIIntra-Proc CT Registered CT & MRI



SLICER 3.0


WHAT IS 3D SLICER?

• A platform for exploring novel image analysis and visualization techniques

• A freely-downloadable program – Source code and

executables available for Windows, Linux, and Mac OS X

• Slicer is a research platform:– NOT an FDA approved

medical device – NOT finished – some parts

will work better than others


SLICER FEATURES

• Visualization • Filtering• Registration• Segmentation• DTI• Quantification• Real-time Integration


“SLICER 3”

• Next Generation of the 3D Slicer software• Beta Release in Jan

2007• Slicer 3.0 schedule

for June 2007• www.slicer.org

Image: S Pieper


WHAT IS SLICER 3?

• Total Rework of 3D Slicer

– At least 80% of code rewritten

– New versions of VTK (5.0), ITK (3.2)

– Improved Look and Feel (KWWidgets)

– Improved Modularity• Analysis routines can be used as

plugins or command line executables for batch processing

– Draws on Multi-Institution Community• Kitware, Inc., GE Research, Isomics,

Inc., BWH, UCLA, UCSD, UIowa, MIT, GaTech, UNC, U Utah, MGH, UCI, Harvard, WashU…

• NAC, NCIGT, NA-MIC, mBIRN, fBIRN


• Open Source, multi-platform

• Over 500k lines of code

• www.slicer.org

• Google: slicer 101

Images: A Golby, F Talos, P Black

SLICER 3


Image/Scene Management

• XML-Based MRML File Stores Scene Description– Volumes (Images,

Label Maps)– Models– Hierarchical Affine

Transforms– Scene Data (Cameras,

Colors, Fiducials, etc).• Manipulated in World

Coordinates based on Patient RAS

Image: S Pieper


OPENING SCREEN

The default display provides for primary 2D planes and a 3D Viewer space.Other display options can be selected.

screen_01


LOAD VOLUME FILE

screen_03

Having selected the Volumes Module …Images can be selected as DICOM or .nrrd files.

Here, a pre-procedural MRI scan of the liver is opened.


VISUALIZE MRI DATA

screen_04

MRI opens in three orthogonal 2D planes.


TUMOR LOCATION

screen_05

3D image planes can be viewed in the 3D space.

Can zoom, translate, rotate.

Here we locate tumor in all 3 planes (arrows)


3-D ONLY

screen_06 & 07

View MRI planes in 3D Viewer from above …

and from below.


Add Volume CT

screen_08

Add a volume to the space …

Here, an intra-procedural CT dataset is opened.


CT opens in three orthogonal 2D planes.

screen_09

VISUALIZE CT DATA


PREP FOR LINEAR TRANSFORM

screen_10

Initial alignment of MRI to CT is the Linear Transform 1 under Transform Module.

This manual transform is one of two options.


Initial linear alignment solves initial displacement of MRI and CT.

Seen here in the 3D Viewer.

screen_20

LINEAR TRANSFORM

© NIH National Center for Image-Guided Therapy, March 2008 IGT Clinical Workshop screen_22

PREP FOR AUTO TRANSFORM

Initial alignment of MRI to CT can be done by selecting Linear under Registration Module menu.

This automatic transform is the second of two options.

© NIH National Center for Image-Guided Therapy, March 2008 IGT Clinical Workshop screen_21c

RESULT OF RIGID REGISTRATION

Slider can be used to review the result of the linear alignment between the pre-procedural MRI and intra-procedural CT.


PREP FOR B-SPLINE REGISTRATION

Alignment can be done on the data using the Deformable B-Spline B-Spline Registration option.


RESULT OF B-SPLINE REGISTRATION

Slider can be used to review the result of the linear alignment between the pre-procedural MRI and intra-procedural CT.


CLINICAL SIGNIFICANCE

Image Registration has relevance for all aspects of an ablation procedure: Plan, Target, Monitor, Control, AssessThis is true for any image guidance modality.


Documents

© NIH National Center for Image-Guided Therapy, March 2008 IGT Clinical Workshop Non-Rigid, Multi-Modality Image Registration for Thermal Ablation: Non-Rigid,