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Literature Review of Image Processing Methods for Myocardial Infarction Studies in MRI and CT-Scan (a comparsion)
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VIBOT 4
2011
Literature Review of Image Processing Methods for Myocardial Infarction Studies in MRI and CT-Scan
By:Vanya Vabrina V
Rui Hua
What is Myocardial Infarction (MI)?
Heart attack
Need immediate
treatment
Type of Diagnosis
SPECT limitation:ExpensiveDose heavy + ionizing radiationArtifact pronePoor spatial resolution
Coronary Angiography limitation:Invasive method!
Non-Invasive Solutions:
CT-Scan and MRIPerfusion Imaging
MI limited flow
Cardiac CTMulti-Detector Computed Tomography
(MDCT)
o High-resolution 3D of the moving heart and study the coronary vesselso Cover volumes of anatomy within a single breath-holdo Improved spatial resolutiono Improved temporal resolution
Cardiac MRI
Fast MRI Sequence Gradient EchoMany application in clinical Cardiac MRI:Cardiac function: Cine – MRIPerfusion SSFP Bright blood Breath-hold Inversion recovery pre-pulse
CT – Perfusion Imaging
Pharmacologic Stress agent : Adenosine Contrast agent : Iodine based (e.g, Visipaque) [concentration ~ x-ray absorbtion] Signal-density-time curve ~ CT attenuation over time
MR-Perfusion Imaging
PharmacologicStress agent : AdenosineContrast agent: Gadolinium
(Gd) Signal intensity-time curve ~
contrast agent
Criteria of MI – CT
First-Pass Hypo enhancement
Criteria of MI – MRI
First Pass Imaging (FP)
Examines myocardial tissue perfusion (wash in)
MI criteria: slow wash inHypo-enhancement
Criteria of MI – MRI
Delay enhancement Imaging (DE)
Examine the kinetics of contrast agent elimination (wash out)
MI criteria: slow wash out
Hyper-enhancement
Transmural MI
Sub-endocardial MI
Criteria of MI : DE-MRI
Image Post-Processing
…of MI Diagnosis in CT Scan and MRI Perfusion
Imaging
CT MYOCARDIAL PERFUSION ANALYSIS
CT – Semi Quantitative
First pass imaging upslope analysis can provide semi quantitative measure for myocardial perfusion
Up slope analysisTAC (Time Attenuation Curve)
CT – Semi Quantitative
MI region myocardium with 1 SD below the mean of the remote regionClustering algorithmResult – MI : hypo-perfused blue area
17-segment polar plot of MDCT-derived myocardial signal densities
CT –Visual Analysis
17 segment model
Scored - the absence/presence of a perfusion defect
Graded - reversibility
MRI MYOCARDIAL PERFUSION ANALYSIS
MRI MYOCARDIAL PERFUSION ANALYSIS
Qualitative
Visual assessment
MRI MYOCARDIAL PERFUSION ANALYSIS
Automatic endocardial and epicardial borders detection
Snake Contour
Endocardial delineation: Gradient Vector Flow (GVF) snake algorithm on an edge map
Epicardial delineation:
Thickness
Endocardial contour
Epicardial contour
MRI MYOCARDIAL PERFUSION ANALYSIS
Automatic endocardial and epicardial borders detectionCenterline Method
Geometrical Template dark circular kernel template
Modeled as: Centerline and width
Template deformation to find parameters minimizing a criterion
MRI – FIRST PASS IMAGING
Wash-in within the different regions were assessed by signal-intensity (SI) time curve analysis
MRI – DELAY ENHANCED IMAGING
Quantitative FACT (Feature Analysis and Combined
Threshold )method
MR Image Contoured Image
Histogram Image Pre-Processing
2SD Thresho
ld
Feature analysis FWHM
Region contouring
Feature analysis
Output
MRI – DELAY ENHANCED IMAGING
FACT Result – Contoured MI
MRI – DELAY ENHANCED IMAGING
Quantification MI Volume combine all MI area in contiguous
slicesMeasurement of MI size from the result of FACT
algorithm. Sector based viability measurement
MRI – DELAY ENHANCED IMAGING
Peri-infarct
Core-infarct
Comparison
Object CT Scan MRIContrast
assesmentAttenuation Signal intensity
Criteria in FP Hypo-enhancement
Hypo-enhancement
Criteria in DE Hyper-enhancement
Hyper-enhancement
Functional recovery
Early hypoenhanced
Prediction in DE
Infarct size Over-estimation Good prediction
Late hypoenhancment
Well correlated Well correlated
Comparison Modalities Advantages Limitations
MRI
High CNRHigh accuracy
Limited spatial resolution of MRI in axial direction (slice thickness)
Low ionizing radiation and less toxic contrast agent
Higher cost. Longer scanning time
Highly attractive for viability imaging
Restriction to patients with implanted electronic devices
CT SCAN
Improved spatial resolution
High radiation and contrast dose
Faster/high temporal resolution
Lower CNR
Greatly reduced slice width
Require hardware development to reduce motion artifact
ConclusionMyocardial infarction can be studied non-invasively
using CT and MRI Perfusion imaging.
MRI has low radiation and higher CNR, compared to CT
Image post-processing and criteria (hypo-enhancement in first-pass and hyper-enhancement in delay-enhanced imaging) of MI in CT and MRI are almost similar
Quantification of MI is more accurately evaluated with MRI.
THANK YOU…
References
http://www.medicinenet.com/heart_attack http://www.nhlbi.nih.gov/health/dci/Diseases/HeartAttack /HeartAttack_WhatIs.html
A.C. Lardo, A.S. Cordeiro, et.al. Contrast-Enhanced Multidetector Computed Tomography Viability Imaging After Myocardial Infarction Characterization of Myocyte Death, Microvascular Obstruction, and Chronic Scar. 2006. AHA Journal Circulation, Dallas.113:394-404
Richard T. George, et.al. Multidetector Computed Tomography Myocardial Perfusion Imaging During Adenosine Stress. 2006. Journal of the American College of Cardiology. Vol. 48, No. 1.
C.Valdiviezo, M.Ambrose, et al. Review: Quantitative and qualitative analysis and interpretation of CT perfusion imaging. 2007. Journal of Nuclear Cardiology. Volume 17, Number 6;1091–100.
K. Nieman, M.D. Shapiro, et al. Reperfused Myocardial Infarction: Contrast-enhanced 64-Section CT in Comparison to MR Imaging.2008. Radiology: Volume 247: Number 1—April.
P.Hunold, T.Schlosser. Myocardial Late Enhancement in Contrast-Enhanced Cardiac MRI: Distinction Between Infarction Scar and Non–Infarction-Related Disease. AJR 2005;184:1420–1426
B. L. Gerber, B.Belge, et al. Characterization of Acute and Chronic Myocardial Infarcts by Multidetector Computed Tomography Comparison With Contrast-Enhanced Magnetic Resonance. 2006. AHA Circulation 113;823-833
References
• W.Ksai, K.M. Holohan. Myocardial Perfusion Imaging from Echocardiography to SPECT, PET, CT, and MRI—Recent Advances and Applications. US Cardiology. Touch Briefings, 2010.
A.T. Yan, A. J. Shayne, Characterization of the Peri-Infarct Zone by Contrast-Enhanced Cardiac Magnetic Resonance Imaging Is a Powerful Predictor of Post–Myocardial Infarction Mortality. 2006. AHA Circulation 114;32-39.
A.Schmidt, M.F Azevedo, et al. Infarct Tissue Heterogeneity by Magnetic Resonance Imaging Identifies Enhanced Cardiac Arrhythmia Susceptibility in Patients With Left Ventricular Dysfunction. 2007. AHA Circulation.115;2006-2014.
Glenn S. Slavin, et al. First-Pass Myocardial Perfusion MR Imagingwith Interleaved Notched Saturation: Feasibility Study. Radiology, April 2001. Vol.219: pp.259 – 263.
Li-Yueh Hsu, et al. Quantitative Myocardial Infarction on Delayed Enhancement MRI. Part I: Animal Validation of an Automated Feature Analysis and Combined Thresholding Infarct Sizing Algorithm. 2006. JOURNAL OF MAGNETIC RESONANCE IMAGING 23:298–308.
Li-Yueh Hsu, et al. Quantitative Myocardial Infarction on Delayed Enhancement MRI. Part II: Clinical Application of an Automated Feature Analysis and Combined Thresholding Infarct Sizing Algorithm. 2006. JOURNAL OF MAGNETIC RESONANCE IMAGING 23:309–314.