Microwave-induced Thermoacoustic Imaging for Radio-frequency Tumor Ablation: a Hybrid FDTD Modeling and Experimental study

Transcription

1 Mcrowave-duced Theroacousc Iagg for Rado-frequec Tuor Ablao: a Hbrd FDTD Modelg ad Epereal sud Yg Deg ad Mark Golkowsk Depare of Elecrcal Egeerg Depare of Boegeerg Uvers of Colorado Dever Dowow EE Naoal Rado Scece Meeg Boulder CO Jauar 6 0 Aschuz Medcal Capus BIOE

2 Oule Curre Sae of Iagg Modales Theroacousc Iagg FDTD Hbrd Modelg Model Valdao Applcaos ad Fuure Work

3 Curre Sae of Iagg Techologes X-Ra Copued Toograph CT Relavel cheap ad fas Hgh radao dosage Posro Esso Toograph PET Ca arge specfc rado checals Low hroughpu Eposure o ozg radao Mcrowave Iagg Cheap fas o ozg radao Poor resoluo far feld Lle clcal use

4 Curre Sae of Iagg Techologes Magec Resoace Iagg MRI Grea sof ssue coras No ozg radao eposure Gold sadard for clcal agg Ver hgh capal ad operaoal coss Ulrasoud acousc Hgh resoluo < No ozg radao eposure Cheap ad porable Poor sof ssue coras

5 Mulwave Hbrd Iagg Tras oe pe of wave receve aoher Cobe advaages avod dsadvaages of dvdual odales Phoo-acousc agg [Xu ad Wag Rev. Sc. Isru ] Mcrowave-acousc agg [Mashal e al. Phs. Med. Bol ]

6 Mcrowave-Acousc Iagg Theor acousc wave equao heral epaso drver p r p r = β T r eρ c Teperaure chage s drve b crowave pulse T σ E τ = ρ σ C p p r : pressure Tr : eperaure E : crowaveelecrc feld τ : durao of crowave pulse σ : coducv ρ : ass des c : speed of soud β :volue epaso coeffce e C p :specfc hea

7 Hbrd FDTD Code H H H H D D z z = μ ε E E H H z z = 0 0 μ ε μ ε EM FDTD E E H H z z = μ ε μ ε a v v v v c p p = ρ p p v v = ρ Acousc FDTD p p v v = ρ

8 Sulao Doa Sulao space seup o eulae rece epereal sud [Mashal e al. Phs. Med. Bol ]

9 Sulao Vdeo

10 Epereal Resuls Sol % cro ε r σ S/ v A /s bubble NA NA NA [Mashal e al. Phs. Med. Bol ] Acousc ad EM properes of soluos are dffere Hgher coducv σ elds greaer acousc wave aplude.

11 Sde b Sde Coparso EX XPERIME ENT Model reproduces epereal resuls ver well Epereal daa s based o averages of 00 wave fors SIMULATI ION

12 Delecrc vs. Acousc Effecs Epere: acousc ad delecrc dffereces Sulao: acousc dffereces ol Dffere wavefor bewee soluos resuls fro dffere delecrc properes Sulao: delecrc dffereces ol I agreee wh paper p coclusos

13 No-ufor of E-feld Delecrc Iegrao of E over crowave pulse λ 0 = ; λ d = λ 0 = 00 ; λ d = 6 Mos works assue power deposo s ufor [Peerse Ra Mra Copuaoal Elecroagecs. 998 p. 64] Modelg ad aalcal soluos show ha power deposo has a uque geoerc sgaure

14 Plaed Epereal Work Ulrasoud rasducer Olpus V306 f c =5MHz.5 Mcrowave power suppl Power: kw τ < μsec

15 RF ad Mcrowave Ablao Applcao Rado Frequec f ~ 500 khz ablao s a clcall acceped reae for hepac lver uors Tuors are desroed hrough heral heag Ablao usg crowave sources s also beg clcall vesgaed Mos pressg clcal ssue s lack of predcabl or real e dagoscs of ablao sze whch hders creao of reae plas

16 UC Dever Bove Lver Model [Mogoer RS R.A. Dodd GD III e al.. AJR. 004] Ivesgao of ablao sze as a fuco of blood Ivesgao of ablao sze as a fuco of blood flow Ulrasoud o place elecrode MRI o evaluae sze

17 Thero-acousc agg g ca provde cheap porable real e oorg for clcal ablaos Applcao o Ablao Treae If crowaves are used for ablao sae hardware could provde source for heroacousc agg. 3-D age recosruco algorh eeds o be pleeed. [Kruger e al. Radolog 999]

18 Coclusos A hbrd FDTD Ulrasoud/EM sulao code for heroacousc agg has bee developed ad valdaed Sulao cofrs epereal resuls of Mashal e al. [009] ha delecrc properes of ssue phaos doae acousc respose Assupo of ufor of power deposo s show o o be copleel accurae for sall delecrc srucures Furher develope of heroacousc agg echque ca ad epereal ablao work ad eveuall be releva clcal ablaos