UNASSIGNED: An ultrasound applicator for endoluminal thermal therapy of @entity788 has been introduced and evaluated through acoustic/biothermal simulations and ex vivo experimental investigations. Endoluminal therapeutic ultrasound constitutes a minimally invinvasive conformal therapy and is compatible with ultrasound or MR-based image guidance. The applicator would be placed in the stomach or duodenal lumen, and sonication would be performed through the luminal wall into the @entity5 , with concurrent water cooling of the wall tissue to prevent its thermal injury. A finite-element (FEM) 3D acoustic and biothermal model was implemented for theoretical analysis of the approach. Parametric studies over transducer geometries and frequencies revealed that operating frequencies within 1-3 MHz maximize penetration depth and lesion volume while sparing damage to the luminal wall. @entity1 -specific FEM models of @entity788 were generated and used to assess the feasibility of performing endoluminal ultrasound thermal ablation and @entity221 of @entity788 . Results indicated over 80% of the volume of small @entity5 (~2 cm diameter) within 35 mm of the duodenum could be safely ablated in under 30 minutes or elevated to hyperthermic temperatures at steady-state. Approximately 60% of a large @entity5 (~5 cm diameter) model could be safely ablated by considering multiple positions of the applicator along the length of the duodenum to increase coverage. Prototype applicators containing two 3.2 MHz planar transducers were fabricated and evaluated in ex vivo porcine carcass heating experiments under MR temperature imaging (MRTI) guidance. The applicator was positioned in the stomach adjacent to the pancreas, and sonications were performed for 10 min at 5 W/cm(2) applied intensity. MRTI indicated over 40  C temperature rise in pancreatic tissue with heating penetration extending 3 cm from the luminal wall.

Development of an endoluminal high-intensity ultrasound applicator for image-guided thermal therapy of XXXX .

@entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'tumors'] @entity1 :: ('9606', 'Species') :: ['Patient'] @entity788 :: ('MESH:D010190', 'Disease') :: ['pancreatic head tumors', 'pancreatic tumors'] @entity221 :: ('MESH:D005334', 'Disease') :: ['hyperthermia']
@entity788 :: (MESH:D010190,Disease) :: ['pancreatic tumors']
