QIBA CT Volumetrics - Cross-Platform Study (Group 1C) March 18, 2009 Interclinic Comparison of CT Volumetry Quantitative Imaging Biomarker Alliance.

Slides:



Advertisements
Similar presentations
IMAGE GENERATION IN CT.
Advertisements

CT Scanning: Dosimetry and Artefacts
Image Reconstruction.
Improved Conspicuity of Abdominal Lesions with Single-Source Dual-Energy MDCT Hadassah Hebrew University Medical Center Jerusalem, Israel Ruth Eliahou.
Image Quality Bushong Chapter 7.
IMAGE QUALITY.
Key CT Parameters - What Are They Called and What Do They Mean?
Computed Tomography II
Spiral CT Bushong Chapter 5.
Seeram Chapter 13: Single Slice Spiral - Helical CT
RAD309 Patient Dose.
NC HPS Meeting 10/18-19/2001 Boone, NC Recent Advances in CT Technology and Issues of CT Dosimetry T. Yoshizumi 1,2, M. Sarder 1, R. Reiman 1,2, E. Paulson.
Radiation Protection and Diagnostic Imaging Physicist
MULTISLICE CT.
1 Physics Testing for Performance Based Protocol version 3.0 (Now based on ACRIN 6678) QIBA Group 1C.
5 th September 2005 Paul Collins Computed Tomography Dosimetry Assessment of Effective Dose in Computed Tomography using an Anthropomorphic Phantom Paul.
How CT / MSCT works  Imageaquisition:. How CT / MSCT works.
Advanced Biomedical Imaging
David E. Hintenlang, Ph.D., DABR
CT Multi-Slice CT.
IMAGE QUALITY NOISE LINEARITY CROSS-FIELD UNIFORMITY IMAGE ARTIFACTS.
Computed Tomography III
Volumetric Measurement of Tumors David F. Yankelevitz, MD.
Current Topics in Medical Physics Research Xiaoming Zheng, PhD. School of Dentistry and Health Science Chengdu, China, 2009.
Special Imaging Techniques Chapter 6 Bushong. Dynamic Computed Tomography (DCT) Dynamic scanning implies 15 or more scans in rapid sequence within one.
tomos = slice, graphein = to write
QA in digital mammography: local activities and remote control H. Bosmans et al.
Seeram Chapter 11: Image Quality
CT Quality Control for CT Scanners. Quality Control in CT A good idea? Yes Required for accreditation? Sometimes Improves image quality? Sometimes Depends.
QIBA CT Volumetrics - Cross-Platform Study (Group 1C) May 6, 2009 Interclinic Comparison of CT Volumetry Quantitative Imaging Biomarker Alliance.
QIBA Quantitative CT: Towards routine quantitative CT in obstructive lung disease JP Sieren 1, PF Judy 2, DA Lynch 3, JD Newell 3, HO Coxson 4 and EA Hoffman.
Context: How does Profiling fit in to what we are trying to accomplish overall? 9/3/2015Buckler Biomedical1 Public Data Infrastructure QIBA Define Profiles.
Update on Lung Cancer Image Processing Rick Avila Karthik Krishnan Luis Ibanez Kitware, Inc. April 19, 2006.
Dose Survey in Computed Tomography DS /CM Kampala IAEA/RCA Kampala.
Radiation Protection of Patients Unit
QIBA CT Volumetrics - Cross-Platform Study (Group 1C) December 23, 2009 CT Cross-platform Sizing of Phantom Lesions Quantitative Imaging Biomarker Alliance.
CT physics and instrumentation
Computed Tomography Q & A
Reduction of effective and organ dose to the eye lens in cerebral MDCT scans using iterative image reconstruction Zizka J, Jandura J, Kvasnicka T, Klzo.
Factors affecting CT image RAD
S Demehri 1, M.K Kalra 2, M.L Steigner 1, F.J Rybicki 1, M.J. Lang, 3, S.G Silverman 1. 1.Department of Radiology, Brigham & Women's Hospital, Harvard.
QIBA CT Volumetrics - Cross-Platform Study (Group 1C) September 2, 2009 Interclinical Comparison of CT Volumetry Quantitative Imaging Biomarker Alliance.
QIBA CT Volumetrics Group 1B: (Patient Image Datasets) Update April 19, 2011.
QIBA CT Volumetrics Group 1B: (Patient Image Datasets)
IAEA International Atomic Energy Agency Optimization of Protection in Computed Tomography (CT)-What can radiographers do? IAEA Regional Training Course.
QIBA CT Volumetrics Group 1B: (Patient Image Datasets) Teleconference Nov 5, 2008.
N Petrick RSNA QIBA Phantom Group November 13, QIBA Proposed Phase 1A Project V5.0 QIBA Phantom Subgroup.
Image Quality The capacity to define, measure, and assess image quality is a primarily responsibility of a CT Technologist.
MEASUREMENTS OF RADIATION DOSES IN MULTISLICES COMPUTED TOMOGRAPHY EXAMINATIONS A. ELMAHDI*, A. SULIEMAN *Presenting author 1 Sudan Atomic Energy Commission,
CT QUALITY MANAGEMENT. SPATIAL RESOLUTION CONTRAST RESOLUTION NOISE IMAGE ARTIFACTS RADIATION DOSE.
Part No...., Module No....Lesson No
Part No...., Module No....Lesson No
Quality Assurance.
1 Physics Testing for Performance Based Protocol version 2.1 QIBA Group 1C.
What are the dose quantities in CT ? IAEA/RCA Kampala Kampala.
Impact of Contrast Media Concentration and kVp settings on Image Quality in CT Angiography of the Intracranial Vessels Birgitta Ramgren MD Roger Siemund.
CONVENTIONAL AND SPIRAL/HELICAL CT
History: A 61-year-old man with suspected thoracic aneurysm underwent ECG-gated chest CT angiogram. He was instructed to hold his breath during the exam.
Computed Tomography Computed Tomography is the most significant development in radiology in the past 40 years. MRI and Ultrasound are also significant.
Computed tomography. Formation of a CT image Data acquisitionImage reconstruction Image display, manipulation Storage, communication And recording.
Basic Principles of CT Scanning. CT CT - Computed Tomography CAT Scan - Computerized Axial Tomography.
IMAGE QUALITY. SPATIAL RESOLUTION CONTRAST RESOLUTION NOISE IMAGE ARTIFACTS RADIATION DOSE.
Single Slice Spiral - Helical CT
-42 Impact of signal non-repeatability on spectral CT images
CT Multi-Slice CT.
Optimisation of Patient Protection for Radiography
Advantages of spiral CT
Physics Testing for ACRIN 6678 Protocol version 3.0 QIBA Group 1C
Wednesday Case of the Day
Presentation transcript:

QIBA CT Volumetrics - Cross-Platform Study (Group 1C) March 18, 2009 Interclinic Comparison of CT Volumetry Quantitative Imaging Biomarker Alliance

Charge 1. To agree on the scanner settings and other protocol elements under which imagery is to be collected. 2. To agree on requirements of phantoms to be imaged/measured. 3. To agree on the platforms and centers to be selected under which imagery is to be collected. 4. To identify the measurements and the algorithms for use in image processing. 5. To specify the analysis of the measurements.

Goals 1. Measure the volume of nodules on CT imagery collected from several CT scanners and sites (includes single scanners with varying settings). 1. Measure image noise and determine its impact on the measurement of volume. 2. Compare the accuracy and precision of volume measurements for these phantom datasets. 3. Determine the minimum detectable level of change that can be achieved when measuring nodules in phantom datasets.

Goal 1 1.Measure nodule volume on CT imagery collected from several CT scanners/sites (including single scanners with varying settings). Determine the systems to be used and the system settings to be varied. (a) kVp constant. (b) mAs constant. (c) collimation fixed (+) (d) field of view ([rib-to-rib]skin-to-skin = closest possible view)- (e) reconstruction filters – follow-up Wendy & radiologists -Find “equivalent” filters. Site selection – poll the team. Scanners follow sites.

Goal 2 2. Measure “image noise” and determine its impact on the measurement of volume. Facilitates inter-comparison of scanner results. (a) Characterizing / specifying image quality (a) Expert visual assessment of image quality. (Deni)

QIBA – What to do? Experiments Investigate parameter space to determine which parameters make a difference in the task (CT tumor volume and volume measurement over time) QIBA CT 1-A and 1-B already contribute to this investigation? NOTE: Different biomarkers (e.g. lesion density or mass) may be affected by different parameters.

QIBA CT 1-C Profiles - 1 As with NLST and ACRIN 6678, we could specify kVp, slice thickness, mAs, rotation time, pitch, reconstruction kernel (affects MTF) (NOTE: These operating parameters serve as a proxy for physical performance with respect to spatial resolution, noise and dose.)

QIBA CT 1-C Profiles - 2 ALTERNATIVE (not necessarily exclusive OR): Specify PERFORMANCE metrics such as simple spatial resolution and noise metrics.  kVp (affects contrast difference between materials)  Slice thickness, recon interval (affects z-axis resolution & noise)  Rotation time and pitch (coverage, breath hold, etc.)  Recon kernel OR recon kernel performance –e.g. Choose kernel such that you can see 6 or 7 (but no more than 7) lp/cm on ACR phantom….or –10% MTF should be between 6 and 7 lp/cm  mA/effective mAs level OR mA level performance –e.g. Choose 40 effective mAs OR –Choose effective mAs level so that std dev is between 20 and 30 HU in 20 cm water phantom

QIBA – What to do?  Near Future: –Specify  MTF  NPS  Z-axis resolution  Dose  Some SNR metric appropriate for measurement task  Further: –Specify  3D MTF  3D NPS  Organ dose  Some SNR/Dose metric appropriate for measurement task/risk

Example Protocol Chart for NLST (from Cagnon et al) ParameterSiemens Vol Zoom/ Sensation 4 4-slice/0.5 sec 4 x 2.5 Siemens Vol Zoom/ Sensation 4 4-slice/0.5 sec 4 x 1 Siemens Sensation x.75 Siemens Sensation 64 64x.0.6 (beam collimation 32x0.6) kV120 Gantry Rotation Time0.5 sec 0.50 sec mA (Regular patient-Large patient values) mAs (Reg-Lg) Scanner effective mAs 2 (Reg-Lg) Detector Collimation (mm) - T2.5 mm1 mm0.75 mm0.6 mm Number of active channels - N Detector Configuration - N x T4 x 2.5 mm4 x 1 mm16 x.75 mm32 x 0.6 mm Collimation (on operator console)N/A 64x0.6mm Table incrementation (mm/rotation) - I15 mm8 mm18 mm19.2 mm Pitch ([mm/rotation] /beam collimation) - I/NT Table Speed (mm/second)30 mm/sec16 mm/sec36 mm/sec38.4 mm/sec Scan Time (40 cm thorax) 13 sec25 sec11 sec Nominal Reconstructed Slice Width3 mm2 mm Reconstruction Interval mm1.8 mm Reconstruction Algorithm 3 B30 # Images/Data set (40 cm thorax) CTDI vol (Dose in mGy) – 4.1 mGy mGy mGy

Goal 3 Compare the accuracy and precision of measurements for these phantom datasets. Which measurements: image mask? Volume? RECIST? (a) RECIST vs. volume (b) Investigate variance & bias. (c) Inter-system variation. (d) Intra-system variation.

Goal 4 4. DEFER: Determine the minimum detectable level of change that can be achieved when measuring nodules in phantom datasets.

Existing Resources  RadPharm –What mark-up is recommended? What format?  RECIST  Segmentation mask. Formats?

Next Steps  Continue to Refine Questions and Experimental Design (similar to 1A and 1B)  Recruit participating clinics. Share and discuss plan with associated medical physicists.