Robust and semantic needle detection in 3D ultrasound using orthogonal-plane convolutional neural networks.

Purpose: During needle interventions, successful automated detection of the needle immediately after insertion is necessary to allow the physician identify and correct any misalignment of the needle and the target at early stages, which reduces needle passes and improves health outcomes.

Methods: We present a novel approach to localize partially inserted needles in 3D ultrasound volume with high precision using convolutional neural networks. We propose two methods based on patch classification and semantic segmentation of the needle from orthogonal 2D cross-sections extracted from the volume.

Quantitative imaging performance of frequency-tunable capacitive micromachined ultrasonic transducer array designed for intracardiac application: Phantom study.

Commercially available intracardiac echo (ICE) catheters face a trade-off between viewing depth and resolution. Frequency-tunable ICE probes would offer versatility of choice between penetration or resolution imaging within a single device. In this phantom study, the imaging performance of a novel, frequency-tunable, 32-element, 1-D CMUT array integrated with front-end electronics is evaluated.

Near-Field Ultrasound Imaging During Radiofrequency Catheter Ablation: Tissue Thickness and Epicardial Wall Visualization and Assessment of Radiofrequency Ablation Lesion Formation and Depth.

Background: Safe and successful radiofrequency catheter ablation depends on creation of transmural lesions without collateral injury to contiguous structures. Near-field ultrasound (NFUS) imaging through transducers in the tip of an ablation catheter may provide important information about catheter contact, wall thickness, and ablation lesion formation.

Methods And Results: NFUS imaging was performed using a specially designed open-irrigated radiofrequency ablation catheter incorporating 4 ultrasound transducers.

Preclinical Testing of Frequency-Tunable Capacitive Micromachined Ultrasonic Transducer Probe Prototypes.

In intracardiac echocardiography (ICE) it may be beneficial to generate ultrasound images acquired at multiple frequencies, having the possibility of high penetration or high-resolution imaging in a single device. The objective of the presented work is to test two frequency-tunable probe prototypes in a preclinical setting: a rigid probe having a diameter of 11 mm and a new flexible and steerable 12-Fr ICE catheter. Both probes feature a forward-looking 32-element capacitive micromachined ultrasonic transducer array (aperture of 2 × 2 mm) operated in collapse mode, which allows for frequency tuning in the 6-MHz-18-MHz range.

Medical Instrument Detection in 3-Dimensional Ultrasound Data Volumes.

Ultrasound-guided medical interventions are broadly applied in diagnostics and therapy, e.g., regional anesthesia or ablation.

Frequency Tuning of Collapse-Mode Capacitive Micromachined Ultrasonic Transducer.

The information in an ultrasound image depends on the frequency that is used. In a clinical examination it may therefore be beneficial to generate ultrasound images acquired at multiple frequencies, which is difficult to achieve with conventional transducers. Capacitive micromachined ultrasonic transducers (CMUTs) offer a frequency response that is tunable by the bias voltage.

High-resolution resonant and nonresonant fiber-scanning confocal microscope.

We present a novel, hand-held microscope probe for acquiring confocal images of biological tissue. This probe generates images by scanning a fiber-lens combination with a miniature electromagnetic actuator, which allows it to be operated in resonant and nonresonant scanning modes. In the resonant scanning mode, a circular field of view with a diameter of 190 μm and an angular frequency of 127 Hz can be achieved.