No abstract available.
Ultrasonography ; Ultrasonography, Interventional

Humans ; Extremities ; Ultrasonography, Interventional

Ultrasound guided needle biopsy or catheterization is a rising operation in clinical diagnosis and treatment. However, poor visualization under ultrasound is the main disadvantage of this technique. This paper summarized the basic methods used to solve such problem, as well as the corresponding product technical requirements.
Catheters ; Needles ; Ultrasonics ; Ultrasonography ; Ultrasonography, Interventional

Anesthesia, Conduction ; Nerve Block ; Ultrasonography ; Ultrasonography, Interventional

We report our experience in coronary angioplasty and intravascular ultrasonography (IVUS) on a heavy, encircling, calcified lesion that was not dilated with the use of a cutting balloon and a non-compliant balloon. The angioplasty was successfully performed with a simple and inexpensive hugging balloon technique.
Angioplasty ; Angioplasty, Balloon ; Coronary Stenosis ; Ultrasonography, Interventional

Equipment Failure ; Humans ; Stents ; Ultrasonography, Interventional

In this paper, we propose an image-based key frame gating method to reduce motion artifacts in intravascular ultrasound (IVUS) longitudinal cuts. The artifacts are mainly caused by the periodic relative displacement between blood vessels and the IVUS catheter due to cardiac motion. The method is achieved in four steps as following. Firstly, we convert IVUS image sequences to polar coordinates to cut down the amount of calculation. Secondly, we extracted a one-dimensional signal cluster reflecting cardiac motion by spectral analysis and filtering techniques. Thirdly, we designed a Butterworth band-pass filter for filtering the one-dimensional signal clusters. Fourthly, we retrieved the extremes of the filtered signal clusters to seek key frames to compose key-frames gated sequences. Experimental results showed that our algorithm was fast and the average frame processing time was 17ms. Observing the longitudinal viewpictures, we found that comparing to the original ones, the gated sequences had similar trend, less saw tooth shape, and good continuity. We selected 12 groups of clinical IVUS sequences [images (876 +/- 65 frames), coronary segments length (14.61 +/- 1.08 mm)] to calculate vessel volume, lumen volume, mean plaque burden of the original and gated sequences. Statistical results showed that, on one hand, both vessel volume and lumen volume measured of the gated sequences were significantly smaller than those of the original ones, and there was no significant difference on mean plaque burden between original and gated sequences, which met the need of the clinical diagnosis and treatment. On the other hand, variances of vessel area and lumen area of the gated sequences were significantly smaller than those of the original sequences, indicating that the gated sequences would be more stable than the original ones.
Algorithms ; Artifacts ; Heart ; Humans ; Motion ; Ultrasonography, Interventional

In order to facilitate doctors to better obtain cardiovascular images by using intravascular ultrasound imaging system and make a more accurate diagnosis, a digital coordinate conversion method of intravascular ultrasound imaging system based on CORDIC algorithm is proposed, it converts polar coordinates into rectangular coordinates through angular rotation and orientation calculation. The experimental simulation test is carried out on the platform of intravascular ultrasound imaging system by FPGA. Experimental simulation shows that, CORDIC algorithm can effectively output sine and cosine values, compared with the traditional table finding method, this algorithm has faster speed, stronger real-time performance and needs less hardware resources. It is more suitable for intravascular ultrasound imaging system.
Algorithms ; Computer Simulation ; Computers ; Ultrasonography, Interventional

Percutaneous coronary intervention (PCI) of stumpless chronic total occlusion (CTO) lesions with a side branch stemming from the occlusion have a significantly lower treatment success rate because physicians cannot identify an accurate entry point with only conventional angiographic images. An intravascular ultrasonography (IVUS)-guided wiring technique might be useful for the penetration of stumpless CTO. We recently experienced thrombotic occlusion during an IVUS-guided stumpless CTO procedure. The cause of the thrombosis is not completely understood; the thrombosis may have been associated with the long use of the IVUS catheter. Special precautions should be taken to prevent thrombus in such cases.
Catheters ; Percutaneous Coronary Intervention ; Thrombosis ; Ultrasonography, Interventional

Blocks of the ganglion impar are used to treat both malignant and benign causes of visceral and sympathetic pelvic and perineal pain. While conventionally done under fluoroscopic guidance, significant improvements in transducer technology in the past decade have piqued the interest and enthusiasm of interventional pain specialists toward ultrasound-guided performance. In the setting of a pandemic, it is important to ensure the efficacy of treatment as well as the safety of both patients and health care workers. This paper presents two patients who underwent two approaches of ultrasound-guided ganglion impar blocks in a tertiary government hospital in the Philippines during the COVID-19 pandemic.