Precision Targeted Ablation of Fine Neurovascular Structures In Vivo Using Dual-mode Ultrasound Arrays

Figures

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  Figure 1. Experimental setup. (A) DMUA containing 64-elements (please expand). (B) DMUA is placed over the bifurcation region. A water bolus filled with degassed water provides acoustic coupling of the transducer to the skin of the rat.

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  Figure 2. DMUA imaging for identification of the CA bifurcations and other tissue landmarks for guidance.

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  Figure 3. (A) B-mode axial view of the right carotid bifurcation of an SHR rat (the main CA is on the left). (B) B-mode cross sectional view of the ICA and ECA just cranial to the bifurcation. (C) C-scan of the right carotid with arrow pointing to the bifurcation point. (D) Schematic representation of the placement of IgFUS shots based on the identification of ICA and ECA in cross-sectional B-mode image.

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  Figure 4. Echogenicity maps from STF frames acquired before (left), during, and after the application of IgFUS. The target (red circle) was the dorsal wall of the ECA. Scale bar represents 1 mm distance.

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  Figure 5. Echogenicity profiles with the CLC intensity modulation profile superimposed. Top: At a point at the skin interface (black circle in Fig. 4). Middle: At the target point. Bottom: At a point 2 mm ventral to the target (green circle in Fig. 4).

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  Figure 6. Real-time monitoring of blood pressure in SHR rats that received thermal therapy with DMUA. Mean arterial pressure (MAP) data were plotted against time (in number of days). (A) Unilaterally (n = 3) and bilaterally (n = 4) treated animals showed a decrease in the MAP when CB was directly targeted, and (B) Unilateral (n = 6) and bilateral (n = 5) treatment with FUS to the regions adjacent to the CB showed an increase in the MAP.

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  Figure 7. Histopathological feature of carotid body lesions. (A) Location of the CB at the bifurcation point of the common carotid artery (CCA) in its internal and external branches. The surrounding tissue is represented by striated muscle (left part of the image) and autonomic ganglion (AG) (embedded in connective tissue). The arrow indicates the focal to extensive coagulative area of necrosis affecting the autonomic ganglion and adjacent tissue. (B) Focal to extensive coagulative necrosis was present in AG; and central chromatolysis, perikaryon eosinophilia, vacuolation and karyopyknosis were identified (indicated by the arrows). (C) Focal to extensive coagulative necrosis, congestion and hemorrhage (indicated by the grey arrow) that extended to the adjacent walls (indicated by the black arrow). (D) Presence of focal rhabdomyolysis (myonecrosis) with loss of visible cross-striations, sarcoplasmic fragmentation, karyopyknosis and karyorrhectic nuclei near the periphery of the CB (indicated by the black arrows). The endomysial space is dilated, edematous, with discrete neutrophil and macrophage infiltration (indicated by the grey arrow).

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  Figure 8. DMUA-induced damage to the carotid body. (A) Single shot of FUS delivered using the DMUA system typically induced a lesion of 257 µm. The lesion can be seen either as one (B) or two on each side of the blood vessel (C).