Interventional Ultrasonography Research Articles

Updates in Interventional Ultrasonography

Interventional ultrasonography, including diagnostic, therapeutic, and intraoperative interventions, is a rapidly developing field in both human and veterinary medicine. Growing expertise and significant improvements in the technology have contributed to the innovation of numerous ultrasound-assisted procedures. Ultrasound-guided biopsy and fine-needle aspiration are now commonly performed. New techniques and the indications for other procedures such as cavity drainage, indwelling catheter placement, and intraoperative procedures are presented.

Telemanipulation for application of diagnostic and interventional ultrasound

SummarySeveral research programmes on telemedicine and telerobotics are currently underway, most of them limited to diagnostics and teleconsultation. A new research and development programme started within the European workframe Advanced Communications Technologies and Services (ACTS), has the aim of developing and building two prototypes of remote controlled robots for interventional and laparoscopic ultrasonography. 11 centres (either clinical or technical) from six countries are taking part in the multimedia interactive demonstrator telepresence project (MIDSTEP). The user requirements for systems for diagnostic and interventional ultrasound (US) have been defined and evaluated in MIDSTEP Work-Package 1, whereas in Work-Package 2, all functional specifications have been included. The system architecture includes hardware, software and a communications network. The hardware consists mainly of a control station and a robot station, which includes a manipulator robot. Within the communication network, there are synchronous and asynchronous channels. Asynchronous transfer mode (ATM) lines are used for long distance transfer. Software for both the control (expert) station and the robot station (patient location) is under development. Special software will be developed to monitor all system functions and control all safety mechanisms, as well as to guarantee the security of data communication. In the teleinterventional US scenario, the robot scans the abdominal organs and performs, under US guidance, a fine needle aspiration puncture. In the laparoscopic US probe telemanipulation scenario, an expert in a control station moves the laparoscopic US probe in order to scan the abdominal organs during diagnostic laparoscopy.

IMO 1419 Interventional abdominal ultrasonography in critically ill patients

IMO 1419 Interventional abdominal ultrasonography in critically ill patients

Efficacy of sonography as a guidance technique for biopsy of abdominal, pelvic, and retroperitoneal lymph nodes.

In the United States, CT is generally considered the guidance technique of choice for biopsy of abdominal, pelvic, and retroperitoneal lymph nodes. The aim of this study was to evaluate the efficacy of sonography for this purpose. We attempted 26 sonographically guided biopsies of five abdominal, six pelvic, and 12 retroperitoneal lymph nodes in 23 patients. The patients included 19 women and four men who were 26-76 years old (mean, 50 years old). The nodes were less than 2 cm in 16 patients, 2-3 cm in four patients, and greater than 3 cm in three patients. Biopsies were considered successful if the nodes could be visualized and biopsied using sonographic guidance and the pathologist's final report indicated that the tissue specimens obtained were adequate for diagnosis. The length of the procedures and the number of complications were recorded. Lymph nodes were visualized and biopsied with sonographic guidance in 23 (88%) of the 26 attempts. Three biopsies could not be performed with sonography because of poor visualization of the nodes. Adequate tissue for cytologic or histologic evaluation was obtained in 21 (91%) of the 23 sonographically guided procedures. In the 21 successful procedures, clinical and imaging follow-up showed no evidence of false-negative diagnoses. The time from the placement of the patient in the interventional sonography room to completion of the procedure ranged from 25 to 60 min (mean, 35 min) for sonographically guided biopsies. We had no procedure-related complications. Sonography is an accurate and safe guidance technique for lymph node biopsies in the abdomen, pelvis, and retroperitoneum. This technique is efficacious for deep nodes as small as 1 cm in diameter. The advantages of sonography over CT include no need for ionizing radiation, portability, shorter procedure time, and real-time visualization of the needle throughout the procedure. These advantages, and the fact that sonography costs less than CT, suggest that sonography is a more appropriate guidance technique in this era of cost containment.

From the RSNA refresher courses. Freehand interventional sonography in the breast: basic principles and clinical applications.

The skills needed to perform ultrasonographic (US)-guided interventional procedures in the breast can be learned by practicing the key maneuvers on a tissue phantom. Use of a tissue phantom rather than a synthetic phantom provides the tactile feedback from transducer movement against tissue and from needle insertion into tissue, which more closely simulates the performance of the procedure in a real breast. There are three key transducer motions--sweeping, rocking, and rotating--that are used to achieve three important goals in US-guided procedures: finding the needle, maximally visualizing the needle, and correctly aligning the needle shaft and ultrasound beam. For each transducer maneuver, there is a corollary needle motion that can be used to achieve the same goal. Either the transducer or the needle should be moved during a procedure, not both simultaneously. Longitudinal alignment of the needle shaft with the ultrasound beam is best achieved with the perpendicular approach. The perpendicular approach is preferred because it allows superior needle visualization, orientation parallel to the chest wall, and location of the needle shaft at the focal zone. With use of a tissue phantom, the radiologist-in-training can practice the key procedures and tailor them to his or her individual preferences.

Percutaneous alexandrite laser lithotripsy of gallbladder stones combined with ultrasound-guided fine needle puncture — preclinical and first clinical results

By transforming optical energy into mechanical energy in the form of shock waves produced via plasma formation, the pulsed alexandrite solid-state laser represents a new technique for fragmentation of gallbladder stones. The highly flexible laser fibers are thin enough (diameter 320 μm) to be used intracorporally with catheters in the fine needle range (< 4F). Due to the lack of plasma ignition in organic tissues (‘tissue recognition’) the alexandrite laser technique can be employed without direct vision. Laser-induced shock waves were used in vitro to disintegrate 138 gallbladder stones of known weight and chemical composition to fragment sizes < 2 mm. Fragmentation of pure cholesterol stones was poor whereas fragmentation of mixed stones was good. In preclinical in-vitro and post-mortem studies, ultrasound-guided gallbladder puncture using catheters in the fine needle range produced no significant bleeding, bile leakage or other complications provided the percutaneous transhepatic route of the needle reached the gallbladder in the area of its attachment to the liver. In the early clinical studies, alexandrite laser lithotripsy combined with interventional ultrasonography was carried out in 14 patients immediately before elective (conventional or laparacopic) cholecystectomy. Fragmentation of mixed stones was good, producing fragments small enough to pass spontaneously. Our new method may be a further minimal invasive alternative in non-operative therapy of symptomatic non-cholesterol gallbladder stones.

Report of the Council on Scientific Affairs: Ultrasonic Imaging of the Heart: Report of the Ultrasonography Task Force

The use of ultrasonography in cardiology has progressed so dramatically that not only is anatomic information available but information can also be derived about cardiac hemodynamics. Applications range from intravascular ultrasonic imaging of coronary atherosclerosis to predictions of the severity of fetal valvular pulmonic stenosis detected in utero. We reviewed cardiac ultrasonography as utilized in B-mode imaging, pulsed and continuous-wave spectral Doppler, and Doppler color flow mapping. We reviewed specialized areas, including stress echo for wall motion analysis, valvular and congenital heart disease applications, and new applications in intraoperative, transesophageal, contrast echography, coronary imaging, and fetal echocardiography. Finally, future applications of quantitative flow mapping and intraluminal and interventional ultrasonography were considered along with the required technological advances.

Major complications and deaths due to interventional ultrasonography: A Review of 8000 cases

Complications related to approximately 8000 ultrasound-guided punctures performed in our institution during the last 19 years are reported. This study includes 3500 fine needle biopsies, 700 large bore needle biopsies, 2800 punctures of fluid collections using either a 1.2-mm spinal needle or a 7.5 F pigtail catheter, and 1000 percutaneous nephrostomies. The majority were abdominal punctures. The complication rate was 0.187% (0.100% to 0.313%) and the mortality rate 0.038% (0.013% to 0.113%). Using the fine needle data exclusively, these rates were 0.200% (0.086% to 0.400%) and 0.028% (0.000% to 0.171%), respectively. The 95% confidence limits are in brackets.

Interventional Sonography in Urology

Nephrostomy is probably the most common percutaneous ultrasound-guided intervention. Since it is the basis for access to the collecting system of the kidney, the technique is described in detail. Other forms are diagnostic pyelopuncture and antegrade stenting. Percutaneous surgery requires dilatation of the tract upon puncture in order to introduce instruments for litholapaxy, splinting strictures (endopyeloplasty) or tumor resection. Retroperitoneal accumulations of fluid outside the collecting system can be drained under sonographic view. Ultrasound is further used to localize solid structures (kidney, renal tumor, lymph nodules, prostate) for biopsy.

Present indications and future expectations of ultrasound in surgery.

With the improvement of resolution in the ultrasound image, this technique has become more and more popular as a diagnostic means in various fields of medicine. Surgeons use diagnostic ultrasound pre-, intra- and postoperatively. Preoperatively, it is mainly employed for tumour staging, differential diagnosis of the acute abdomen, assessment of intra-abdominal and intrathoracic fluid in polytrauma and lately for arthrosonography. Intraoperative ultrasound has developed into one of the most important tools in intraoperative decision making in surgery of the liver, the bile ducts and the pancreas. Adenomas of the parathyroid glands may represent an indication for intraoperative ultrasound. Postoperative ultrasound has become increasingly important in the follow-up of tumour patients and the monitoring of patients in the intensive care unit. Interventional sonography can either be diagnostic or therapeutic. Both pre- and postoperatively, it can be used to help acquire material for microbiological, chemical and cytological examination. On the other hand, it is applied for drainage of abscesses and pancreatic pseudocysts, as well as pleural and intra-abdominal fluid collections. The main problem for the surgeon beginning to work with ultrasound today is the lack of training facilities with an experienced teacher. This is the origin of most of the other problems, such as quality control, 24-h service and interobserver-variations. With the new technologies already available or being developed, ultrasound is bound to gain even more importance for the surgeon in the future.