A Methodical Quantification of Needle Visibility and Echogenicity in Ultrasound Images

During ultrasound-guided percutaneous interventions, needle localization can be a challenge. To increase needle visibility, enhancements of both the imaging methods and the needle surface properties have been investigated. However, a methodical approach to compare potential solutions is currently unavailable. The work described here involves automated image acquisition, analysis and reporting techniques to collect large amounts of data efficiently, delineate relevant factors and communicate effects. Data processing included filtering, line fitting and image intensity analysis steps. Foreground and background image samples were used to compute a contrast-to-noise ratio or a signal ratio. The approach was evaluated in a comparative study of commercially available and custom-made needles. Varied parameters included needle material, diameter and surface roughness. The shafts with kerfed patterns and the trocar and chiba tips performed best. The approach enabled an intuitive polar depiction of needle visibility in ultrasound images for a large range of insertion angles.

Percutaneous Image-Guided Pancreatic Duct Drainage: Technique, Results and Expected Benefits

PURPOSE

The aim of this study is to provide a technical detail and feasibility of percutaneous image-guided pancreatic duct (PD) drainage and to discuss its subtleties in a series of patients with obstructed PD.

MATERIALS AND METHODS

Thirty patients presenting with PD obstruction from pancreatic head tumour or pancreatitis were subjected to percutaneous image-guided PD drainage under a guidance of ultrasound or computed tomography. Following the successful puncture of PD, a locking loop drainage catheter was placed using conventional guidewire techniques under real-time fluoroscopy guidance.

RESULTS

The percutaneous drainage of obstructed PD was completed in 29 (96.7%) patients as an independent therapeutic intent or as a bridge to further percutaneous procedures. Clinical improvement following drainage was documented by the gradual reduction in clinical symptoms, including pain, nausea and fever and improved blood test results, showing the significant decrease of amylase concentration. The amount of pancreatic fluid drained post procedure was between 300 and 900 mL/day. No major procedure-related complications were observed. Subsequently, 14 of 29 patients underwent further procedures, including endoluminal placement of metal stent with or without radiofrequency ablation, balloon assisted percutaneous descending litholapaxy (BAPDL), endoluminal biopsy and balloon dilatation using the same drainage tract.

CONCLUSION

The percutaneous PD drainage appears to be a safe and effective procedure. It should be considered in patients with obstructed PD secondary to malignancy, pancreatitis etc., where endoscopic retrograde cannulation has been failed or impracticable. The procedure can also be contemplated either as an independent treatment option or as an initial step for the subsequent therapeutic endoluminal procedures.

Breast Ultrasound Technology and Performance Evaluation of Ultrasound Equipment: B-Mode

Ultrasound (US) has become increasingly important in imaging and image-guided interventional procedures. In order to ensure that the imaging equipment performs to the highest level achievable and thus provides reliable clinical results, a number of quality control (QC) methods have been developed. Such QC is increasingly required by accrediting agencies and professional organizations; however, these requirements typically do not include detailed procedures for how the tests should be performed. In this paper, a detailed overview of QC methods for general and breast US imaging using computer-based objective methods is described. The application of QC is then discussed within the context of a common clinical application (US-guided needle biopsy) as well as for research applications, where QC may not be mandated, and thus is rarely discussed. The implementation of these methods will help in finding early stage equipment faults and in optimizing image quality, which could lead to better detection and classification of suspicious findings in clinical applications, as well as improving the robustness of research studies.

The importance of needle echogenity in ultrasound guided axillary brachial plexus block: a randomized controlled clinical study

OBJECTIVE

In this study we aimed to compare the echogenic needles and the nerve stimulation addition to non-echogenic needles in ultrasound guided axillary brachial plexus block for upper extremity surgery.

METHODS

90 patients were enrolled to the study. The patients were allocated into three groups randomly: Group E (n=30): ultrasound guided axillary block using echogenic needle, Group N (n=30): ultrasound guided axillary block using non-echogenic needle, Group NS (n=30): ultrasound guided axillary block using non-echogenic needle with nerve stimulator assistance. Duration of block procedure, mean arterial pressure, heart rate, pulse-oximetry, onset time of sensory and motor block, duration of sensory and motor block, time to first analgesic use, total need for analgesics, postoperative pain scores, patient and surgeon satisfaction scores were recorded.

RESULTS

Duration of block procedure values were lower in group E and NS, sensory and motor block durations, were significantly lower in group N. Sensorial and motor block onset time values were found lower in group NS but higher in group N. Patient and surgeon satisfaction scores were found lower in group N.

CONCLUSION

We conclude that ultrasound guided axillary block may be performed successfully using both echogenic needles and nerve stimulation assisted non-echogenic needles.

Optimizing the safety and practice of ultrasound-guided regional anesthesia: the role of echogenic technology

PURPOSE OF REVIEW

Significant improvements have been made in the quality of ultrasound imaging, and it is now much easier to see nerves. However, the key to safe ultrasound-guided regional anesthesia is to be able to direct the needle to the target. This relies on good needle visibility. We review the recent advances that have been made in this crucial area.

RECENT FINDINGS

Echogenic needles can improve shaft and tip visibility independent of experience level, compensate for suboptimal scanning technique, allow steeper insertion angles, reduce technical difficulty, and increase both confidence and satisfaction by anesthesiologists. An echogenic needle encourages holding the probe in one place on the patient, only advancing the needle when it can be seen, hence reducing the likelihood of quality-compromising behaviors. The poor visibility of nonechogenic needles when inserted at steeper angles commonly causes the observer to underestimate the insertion depth of the needle. Significant differences in echogenicity are found when comparing the currently available needles.

SUMMARY

Good echogenic needles should increase safety, efficacy, and simplicity, and hopefully further drive the adoption of ultrasound-guided techniques, to the benefit of our patients.