Fluoroscopy and CT Imaging - Queen's...

Fluoroscopy and CTFluoroscopy and CTImagingImaging

3D coordinate space3D coordinate space

Source-1 Source-2

X-ray film-1

X-ray coordsystem

Film-1 coordsystem

Film-2 coordsystem

X-ray film-2

Edison in his fluoroscope, 1896Edison in his fluoroscope, 1896

The first commercial fluoroscopeThe first commercial fluoroscope

XX--ray + Television = Fluoroscopyray + Television = Fluoroscopy

XX--ray image intensifier tuberay image intensifier tube

Siemens

C-arm fluoroscopy

Fluoroscopy images

Biplane fluoroscopy

• Mobile• Real-time• Inexpensive• Good bone contrast• Broad insurance coverage

• Poor soft tissue contrast• Limited rotation• Limited field of view (9-15”)• Often non-isocentric• Object truncation• High X-ray dose to all parties• Need for calibration• Poor/no joint encoding• Image warping• Loss of depth & volume

Siemens

Pros and Cons for C-arm in Surgery

Calibration = determine unknown constant Calibration = determine unknown constant parametersparameters

target

SADSDD

Beam central

Field of View (FOV)

Detector plane

X-ray source

Pixel size

Typical calibration: Typical calibration: shoot images from various shoot images from various angles of a known object and calculate unknown Cangles of a known object and calculate unknown C--arm arm

parametersparameters

The calibration fixture:• A priori known• Precisely machined• Asymmetric• Easy to pick feature points

Image warpingImage warping

Courtesy of Yao & Taylor

Dewarping stepDewarping step--1: Find groove points1: Find groove points

•Find image points corresponding to the centerline of each vertical and horizontal groove

Dewarping stepDewarping step--2 : Fit 52 : Fit 5’’th order th order Bernstein Polynomial CurvesBernstein Polynomial Curves

•Fit a least square smooth curve to each vertical and horizontal groove

•5’th order Bernstein Polynomial

( ) ( )∑=

−−⎟⎟⎠

⎞⎜⎜⎝

kkk vv

kavaaB K

Dewarping stepDewarping step--3 : Unbend the plate3 : Unbend the plate’’s s imageimage

• Unbend the Bersteinpolynomial to straight lines

• Employ a two pass scan line algorithm to dewarp the image with using bilinear interpolation

Full sweep cone beamFull sweep cone beam

• May give perfect volume• Lots of shots• Lots of dose to patient• Ever faster on computer• Possible in realtime

Cone beam CT reconstruction examplesCone beam CT reconstruction examples

Concept of Computed Tomography (CT)Concept of Computed Tomography (CT)

Planar fan beam

Beam configurationsBeam configurations

Spiral CTSpiral CT

Spiral path with 4,8,16,32,64, 128, 256 rows

Scan Examples: Scan Examples: http://www.radiology.uiowa.edu/3d/http://www.radiology.uiowa.edu/3d/

SINGLE SLICE SPIRAL MULTISLICE SPIRAL

CT scannersCT scanners

Examples to CT imagingExamples to CT imaging

Measuring in CT imageMeasuring in CT image

Slice thickness

543210

Slice index

Field of view X

pixel X

Field of view X

Fluoroscopy and CT Imaging - Queen's...

Documents

Fluoroscopy - City University London | Home

Anatomy of Fluoroscopy & CT Fluoroscopy Equipment L04

Radiology / Fluoroscopy

Fluoroscopy - Stanford Universitypem.stanford.edu/.../4...Unit_Operation_and_Safety.pdf · Fluoroscopy: Mobile Unit Operation and Safety 2 essentialeducation self-directed LEARNING

Fluoroscopy presentation

Imaging, Fluoroscopy, and Radiation Safety

Handbook of Fluoroscopy Safety

EXAMINATION HANDBOOK for Fluoroscopy

Fluoroscopy Safety

Fluoroscopy - static.crowdwisdomhq.com

Radiation Protection in Fluoroscopy

Img Fluoroscopy

Fluoroscopy Table - Oakworks · PDF fileThe OAKWORKS Fluoroscopy Table should not be used with Fluoroscopy systems having intensifier screens or film cassettes larger than 12 inches

Fluoroscopy - Stanford Universitypem.stanford.edu/.../2_Operation_and_Safety_of_Fixed_Fluoroscopy_… · Fluoroscopy: Operation and Safety of Fixed Fluoroscopy Units 2 essentialeducation

Fluoroscopy presentation1

An Introduction to Fluoroscopy Safety · PDF fileAn Introduction to Fluoroscopy Safety 2 Introduction Many physicians assume fluoroscopy is inherently safe technology. Yet each year

COMP230 Wk6 Lab Instructions

Fluoroscopy: Viewing Systems

Fluoroscopy Equipment Operation

DIGITAL PROCESSING FOR FLUOROSCOPY-BASED …