A new Ultrasound modality:US ElastographyJoel Chabriais

Why Elastography?In old Egypt, 5 000 years ago, physicians examined the different parts of the body to evaluate elasticity, they knew that a hard mass in an organ is pathologic.In Greek ancient age, for Hippocratic medicine, palpating was an essential time of physical examination.In 21st century, imaging take preeminent place in medicine and Elastography could be considered as an imaging palpation

What is Elastography?Elastography is an imaging technique to measure the stiffness of tissues.Images are acquired before and after soft compression of tissues and the deformation is evaluated.Initially elastography used manual compression and was only qualitative, now some methods appears to apply a non operator dependant compression.

Elastography and USElastography was developed first in the US field.Three step approach:Organs mechanically stressed by either external or internal forces.Measurement of tissues movement induced.Qualitative or quantitative evaluation of tissue elastic properties from the measured displacement of tissues.

Several ApproachesManual compression by operator using the transducer (static elastography).Organ compression by heartbeat or vascular pulsations.Push pulse waves compression.Supersonic shear waves.

Axial and lateral deformations after an axial constraintCourtesy of Dr Anne Tardivon - Institut Curie - ParisStatic Elastography

Ueno Staging

SCORE 3 DCISFibroadenomaCourtesy of Dr Anne Tardivon - Institut Curie - Paris

9x6 mm14x8 mmIDC6 x 5 mm5 x 3 mmFibroadenomaCourtesy of Dr Anne Tardivon - Institut Curie - Paris

IDCCourtesy of Dr Anne Tardivon - Institut Curie - Paris

This measurement quantify elasticity correlation between two regions. The FLR is independent of the compression movement.The 1st region define the lesion and the 2d is the reference (fat).abcdFLR=Mean Elasto FatMean Elasto LesionCourtesy of Dr Anne Tardivon - Institut Curie - ParisStatic ElastographyDevelopment: Quantitative Analysis

Tsukuba University Hospital, JAPANCourtesy of Dr Anne Tardivon - Institut Curie - Paris

155 lesions (108 Benign and 47 Malign) / 140 PatientsCourtesy of Dr Anne Tardivon - Institut Curie - Paris

Courtesy of Dr Anne Tardivon - Institut Curie - ParisElastography: improvementsCompression/Decompression Movements Displacement speed measurementIntegral -> ElasticityElasto Q Mode Information at decompressionAutomatic selection of the best cycleROI on fat and lesionQuantification

Courtesy of Dr Anne Tardivon - Institut Curie - Paris

Acquisition time < 30 ms !!Courtesy of Dr Anne Tardivon - Institut Curie - ParisSuperSonic Elastography

Significant difference benign versus malign:Cancers: E = 170.1 41.6 kPaBenign lesions: E = 53.5 19.8 kPa n= 36Courtesy of Dr Anne Tardivon - Institut Curie - ParisSupersonic Elastography

(kPa)

(kPa)IDC GRADE IIIFibrous MastopathyCourtesy of Dr Anne Tardivon - Institut Curie - Paris

Fields of Application in MedicineBreastThyroidLiverProstate

Elastography in DICOM: Why?Now, several vendors are coming on the market:Until 2008: 1 vendor had products for sale.2008: 3 vendors.2009: several announcements 6 vendors or more. probably every US vendor at short term.At this time, only secondary capture or US objects.All specific information to elastography are lost.

Elastography in DICOM: Why?More and more clinical applications.New BI-RADS edition, planned for 2010, will take into account US elastography for breast imaging.Users would like to be able to store elastography information in their PACS:Additional attributes in US objects?New objects?Some pathology needs elastography follow-up: Probably DICOM SR templates needed

Elastography in DICOM:Who is Concerned?Elastography is US WG 12Elastography for Breast imaging WG 15Elastography needs DICOM SR templates WG 8Other?

Elastography in DICOM:How To Go Further?A motion to ask the concerned WG to investigate the domain to determine if further works needed?Report to DICOM Standards Committee?

US ElastographyAnd after?

MRE* is coming!!!But it is another story ;-)WG 16 wake-up*Magnetic Resonance Elastography

******EN HAUT HITACHIEN BAS SIEMENS*HITACHI*IMAGES SIEMENS (provenance IGR, corinne Balleyguier)**SIEMENS NORI/ BLANCCODAGE COULEUR inverse dHITACHI dur = rouge****************