PMID- 23039619
OWN - NLM
STAT- MEDLINE
DA  - 20121008
DCOM- 20121205
IS  - 0094-2405 (Print)
IS  - 0094-2405 (Linking)
VI  - 39
IP  - 10
DP  - 2012 Oct
TI  - Effects of different parameters in the fast scanning method for HIFU treatment.
PG  - 5795-813
LID - 10.1118/1.4748329 [doi]
AB  - PURPOSE: High-intensity focused ultrasound is a promising method for the
      noninvasive treatment of benign and malignant tumors. This study analyzes the
      effects of scanning path, applied power, and geometric characteristics of the
      transducer on ablation using fast scanning method, a new scanning method that
      uses high-intensity focused ultrasound at different blood perfusion levels.
      METHODS: Two transducers, six scanning paths, and three focal patterns were used 
      to examine the ablation results of the fast scanning method using power densities
      from 1.35 x 10(7) Wm(3) to 4.5 x 10(7) Wm(3) and blood perfusion rates from 2 x
      10(-3) mlmls to 16 x 10(-3) mlmls. The Pennes equation was solved using the
      finite-difference time-domain method to simulate the heating procedure. RESULTS: 
      Based on the results of the fast-scanning method, the different scanning paths
      exhibited small effect on the total treatment time supported by both simulation
      and least-square fit. Similar-sized lesions can result from the five different
      repeated paths, whereas a random path may lead to relative large fluctuations in 
      ablation volume because of asymmetry of the lesions. Higher power levels increase
      the lesion volume and decrease the treatment time required for ablating a target 
      area using the fast scanning method, whereas increased blood perfusion has the
      opposite effect on ablation volume and treatment time. A symmetric lesion can be 
      produced through fast scanning method using a 65-element and a 90-element
      transducer. However, lesion production using the same operation scheme differs
      between the two transducers. CONCLUSIONS: Unlike traditional scanning methods,
      fast scanning method produces a planned lesion regardless of scanning path, as
      long as the path consists of repeated subsequences. This attribute makes fast
      scanning method an easy-operation scheme that produces relatively large symmetric
      lesions in homogeneous tissues. Applied power is the most important factor;
      however, high blood perfusion levels can limit or even hinder the full ablation
      of the target area. Therefore, tissue perfusion and transducer type should be
      given special attention to ensure the success and safety of ablation treatment.
FAU - Qiao, Shan
AU  - Qiao S
AD  - School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai,
      People's Republic of China.
FAU - Shen, Guofeng
AU  - Shen G
FAU - Bai, Jingfeng
AU  - Bai J
FAU - Chen, Yazhu
AU  - Chen Y
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Med Phys
JT  - Medical physics
JID - 0425746
SB  - IM
MH  - Blood Circulation
MH  - High-Intensity Focused Ultrasound Ablation/adverse
      effects/instrumentation/*methods
MH  - Humans
MH  - Models, Biological
MH  - Sonication
MH  - Temperature
MH  - Time Factors
MH  - Transducers
EDAT- 2012/10/09 06:00
MHDA- 2012/12/10 06:00
CRDT- 2012/10/09 06:00
AID - 10.1118/1.4748329 [doi]
PST - ppublish
SO  - Med Phys. 2012 Oct;39(10):5795-813. doi: 10.1118/1.4748329.