Ultrasound Operator Research Articles

The Role of Ovarian Suspension in Endometriosis Surgery: A Randomized Controlled Trial

Study ObjectiveA very high percentage of patients with severe pelvic endometriosis develop adhesions after laparoscopic surgery. The objective of this trial was to evaluate the role of ovarian suspension performed during surgery for severe endometriosis on ovarian adhesions and postoperative pelvic pain. DesignA randomized controlled trial (Canadian Task Force classification I). SettingThe tertiary care University Hospital of Bologna, Bologna, Italy. PatientsEighty patients with ovarian and posterior deep infiltrating endometriosis were included in the study. InterventionsPatients underwent laparoscopic surgery for endometriosis and were randomized sequentially into 2 groups: transient ovarian suspension was performed in the treatment group (n = 40), whereas in the control group (n = 40) ovaries were left free in the pelvis. Symptom intensity (dysmenorrhea, chronic pelvic pain, dyspareunia, dyschezia, and dysuria) were ranked using a visual analog scale. Postsurgical ovarian adhesions were evaluated using transvaginal ultrasonographic scans performed by an ultrasound operator who was blinded to the details of the operative procedure and women's randomization allocation. Complications, lesion localization, endometrioma diameter, and surgery time were recorded. Measurements and Main ResultsAt follow-up, a significantly lower rate of ultrasound-detectable ovarian adhesions with the uterus and the bowel was observed in the treatment group, respectively (46.7% vs 77.3%, p = .003 and 26.7% vs 68.2%, p < .0005). Patients in the control group showed a higher percentage of fixed ovaries with moderate and severe adhesions than the treatment group, respectively (56.8% vs 28.9%, p = .003 and 20.5% vs 8.9%, p = .110). No differences between the 2 groups were found regarding complications and pelvic pain. ConclusionOvarian suspension seems to be an additional effective surgical procedure associated with an increased ovarian mobility in women treated for severe endometriosis. Moreover, it is feasible, safe, simple, and fast. Hence, it should be routinely used during laparoscopic surgery for endometriosis.

Reliable and valid assessment of ultrasound operator competence in obstetrics and gynecology

To explore the reliability and validity of a recently developed instrument for assessment of ultrasound operator competence, the Objective Structured Assessment of Ultrasound Skills (OSAUS). Three groups of 10 doctors with different levels of ultrasound experience in obstetrics and gynecology were included. The novices had less than 1 month of experience, the intermediate group had 12-60 months of experience and the senior participants were all consultants. Fifteen participants performed transabdominal fetal biometry and the other 15 participants performed systematic transvaginal gynecological ultrasound scans. All scans were video-recorded and assessed by two blinded consultants using the OSAUS scale. The OSAUS scores were compared between the groups using the Kruskal-Wallis test, and pass/fail scores were determined using the contrasting-groups method of standard setting. For the transabdominal fetal biometry examinations, the mean ± SD OSAUS scores of the novices, intermediates and senior participants were 1.5 ± 0.4, 3.3 ± 0.6 and 4.4 ± 0.4, respectively (P = 0.003). For the systematic transvaginal scans, the mean ± SD OSAUS scores of the novices, intermediates and senior participants were 1.8 ± 0.2, 3.1 ± 0.1 and 3.9 ± 0.5, respectively (P = 0.003). Post-hoc comparisons showed significant differences between each of the groups for both types of scans. The pass/fail score was 2.5 for the transvaginal scan and 3.0 for the transabdominal biometry examinations. The inter-rater reliability was 0.89. Ultrasound competence can be assessed in a reliable and valid way using the OSAUS scale. The pass/fail scores may be used to help determine when trainees are qualified for independent practice.

Acoustic Propulsion of Nanorod Motors Inside Living Cells

The ultrasonic propulsion of rod-shaped nanomotors inside living HeLa cells is demonstrated. These nanomotors (gold rods about 300 nm in diameter and about 3 mm long) attach strongly to the external surface of the cells, and are readily internalized by incubation with the cells for periods longer than 24 h. Once inside the cells, the nanorod motors can be activated by resonant ultrasound operating at 4 MHz, and show axial propulsion as well as spinning. The intracellular propulsion does not involve chemical fuels or high-power ultrasound and the HeLa cells remain viable. Ultrasonic propulsion of nanomotors may thus provide a new tool for probing the response of living cells to internal mechanical excitation, for controllably manipulating intracellular organelles, and for biomedical applications.

Acoustic Propulsion of Nanorod Motors Inside Living Cells

AbstractThe ultrasonic propulsion of rod‐shaped nanomotors inside living HeLa cells is demonstrated. These nanomotors (gold rods about 300 nm in diameter and about 3 μm long) attach strongly to the external surface of the cells, and are readily internalized by incubation with the cells for periods longer than 24 h. Once inside the cells, the nanorod motors can be activated by resonant ultrasound operating at 4 MHz, and show axial propulsion as well as spinning. The intracellular propulsion does not involve chemical fuels or high‐power ultrasound and the HeLa cells remain viable. Ultrasonic propulsion of nanomotors may thus provide a new tool for probing the response of living cells to internal mechanical excitation, for controllably manipulating intracellular organelles, and for biomedical applications.

Does ovarian suspension following laparoscopic surgery for endometriosis reduce postoperative adhesions? An RCT

Is temporary ovarian suspension following laparoscopic surgery for severe pelvic endometriosis an effective method for reducing the prevalence of postoperative ovarian adhesions? Temporary ovarian suspension for 36-48 h following laparoscopic treatment of severe endometriosis does not result in a significant reduction of postoperative ovarian adhesions. Pelvic adhesions often develop following laparoscopic surgery for severe pelvic endometriosis. Adhesions can cause chronic pelvic pain and fertility problems compromising the success of treatment. Small observational studies suggested that temporary postoperative ovarian suspension to the abdominal wall may significantly reduce the prevalence of postoperative ovarian adhesions. This was a prospective within group comparison double-blind RCT. We recruited premenopausal women with severe pelvic endometriosis who required extensive laparoscopic surgery with preservation of the uterus and ovaries. Severity of the disease and eligibility for inclusion were determined at surgery. A total of 55 women were randomized to unilateral ovarian suspension for 36-48 h, 52 of which were included in the final analysis. Both ovaries were routinely suspended to the anterior abdominal wall during surgery. At the end of the operation, each woman was randomized to having only one ovary suspended postoperatively. The suture suspending the contralateral ovary was cut and a new transabdominal suture was inserted to act as a placebo. Both sutures were removed 36-48 h after surgery prior to discharge. Three months after surgery, all women attended for a detailed transvaginal ultrasound scan to assess ovarian mobility. Both the women and the ultrasound operators were blinded as to the side of postoperative ovarian suspension. The primary outcome was the prevalence of ovarian adhesions as described on ultrasound examination. Secondary outcomes were the severity of adhesions and the presence and intensity of postoperative pain. All 55 participants had severe pelvic endometriosis confirmed at laparoscopy. As each participant had only one of their ovaries suspended at the end of surgery, they acted as their own control. The median interval between ovarian suspension and postoperative scan was 99 days (interquartile range 68-114). There was no significant difference (P = 0.23) in the prevalence of postoperative ovarian adhesions between the suspended (20/52) and unsuspended (27/52) side (38.5 versus 51.9%) [odds ratio 0.56 (95% confidence interval 0.22-1.35)]. Ovaries were suspended postoperatively for 36-48 h. Longer suspension could result in lower prevalence of postoperative adhesions. The value of temporary ovarian suspension in women having surgery for mild-to-moderate endometriosis should be investigated further. The potential benefits of other adhesion prevention strategies, such as surgical barrier agents, in women undergoing surgical treatment for severe pelvic endometriosis should also be explored. E.S. received honoraria from Ethicon for provision of training to healthcare professionals and consultancy fees from Bayer. W.H. was supported by the research fund provided by the Gynaecology Ultrasound Centre, London UK. A.C. is on the advisory board for surgical innovations for which he receives an annual honorarium. A.C. also received support for courses and education from Storz and Johnson and Johnson and support for clinical nursing from Covidien and Lotus. The other authors declared no competing interests. Current Controlled Trials ISRCTN24242218.

Review of essential understanding of ultrasound physics and equipment operation

Ultrasound (US) is being extensively used an imaging tool in regional anesthesia (RA) and pain practice. Although it was first used in a regional block in 1978, it was only in 1994 that the first direct use of US in RA was reported. Like any other medical tool, its utility is only realized when the performing physician is able to understand the principles behind its application. Efficient use of US also requires an understanding of physical variables which can be suitable modified to produce a clear image of the structure of importance. This brief narrative review summarises the advantages of US in RA and pain practice over the conventionally used localising or imaging tools. The second section deals with the physics behind US. It highlights the necessary physical concepts such as wavelength, frequency and generation of US waves. It also informs the reader about the possible US and tissue interactions, use of US transducers and their differences. The third section deals with understanding the control variables in a typical US machine and how they could be modified to improve the image quality. The final section highlights the various artifacts that could be associated.

A Prospective Validation of the IOTA Logistic Regression Models (LR1 and LR2) in Comparison to Subjective Pattern Recognition for the Diagnosis of Ovarian Cancer

This study aimed to assess the accuracy of the International Ovarian Tumour Analysis (IOTA) logistic regression models (LR1 and LR2) and that of subjective pattern recognition (PR) for the diagnosis of ovarian cancer. This was a prospective single-center study in a general gynecology unit of a tertiary hospital during 33 months. There were 292 consecutive women who underwent surgery after an ultrasound diagnosis of an adnexal tumor. All examinations were by a single level 2 ultrasound operator, according to the IOTA guidelines. The malignancy likelihood was calculated using the IOTA LR1 and LR2. The women were then examined separately by an expert operator using subjective PR. These were compared to operative findings and histology. The sensitivity, specificity, area under the curve (AUC), and accuracy of the 3 methods were calculated and compared. The AUCs for LR1 and LR2 were 0.94 [95% confidence interval (CI), 0.92-0.97] and 0.93 (95% CI, 0.90-0.96), respectively. Subjective PR gave a positive likelihood ratio (LR+ve) of 13.9 (95% CI, 7.84-24.6) and a LR-ve of 0.049 (95% CI, 0.022-0.107). The corresponding LR+ve and LR-ve for LR1 were 3.33 (95% CI, 2.85-3.55) and 0.03 (95% CI, 0.01-0.10), and for LR2 were 3.58 (95% CI, 2.77-4.63) and 0.052 (95% CI, 0.022-0.123). The accuracy of PR was 0.942 (95% CI, 0.908-0.966), which was significantly higher when compared with 0.829 (95% CI, 0.781-0.870) for LR1 and 0.836 (95% CI, 0.788-0.872) for LR2 (P < 0.001). The AUC of the IOTA LR1 and LR2 were similar in nonexpert's hands when compared to the original and validation IOTA studies. The PR method was the more accurate test to diagnose ovarian cancer than either of the IOTA models.

20—100 kHz, ultrasound assisted treatment of chronic wounds

We report the results of a limited (20 patients) clinical study involving treatment of chronic wounds (venous ulcers) using novel, fully wearable ultrasound array applicator operating in the range of 20—100 kHz and generating pressure amplitudes close to 55 kPa (about 100 mW/cm2, Sptp). 20 kHz, 15 min exposure was determined to be the most effective in terms of expediting reduction in wound area (p &amp;lt; 0.05). The applicator was designed as compact, tether-free, device that can be comfortably worn by subjects at home, permitting active (combined with traditional compression) therapy away from the clinical setting. The system is safe for extended periods of application and the arrangement of the piezoelectric elements in the applicator has been adjusted allowing patient treatment customization, especially treatment of irregularly shaped ulcers. A set of systematic experiments in vitro aiming at the identification of potential mechanisms of the wound healing was also performed; the results verified that the exposure matrix used in clinical setting as mentioned above (20 kHz treatment for 15 min) produced the greatest increase in cellular metabolism (p &amp;lt; 0.05) and cell (fibroblasts) proliferation (p &amp;lt; 0.01) vs. a sham. The subsequent in vitro experiments will focus on collagen production, crucial to wound healing. [NIH 5R01EB009670.]

Information Extraction for Tracking Liver Cancer Patients' Statuses: From Mixture of Clinical Narrative Report Types

To provide an efficient way for tracking patients' condition over long periods of time and to facilitate the collection of clinical data from different types of narrative reports, it is critical to develop an efficient method for smoothly analyzing the clinical data accumulated in narrative reports. To facilitate liver cancer clinical research, a method was developed for extracting clinical factors from various types of narrative clinical reports, including ultrasound reports, radiology reports, pathology reports, operation notes, admission notes, and discharge summaries. An information extraction (IE) module was developed for tracking disease progression in liver cancer patients over time, and a rule-based classifier was developed for answering whether patients met the clinical research eligibility criteria. The classifier provided the answers and direct/indirect evidence (evidence sentences) for the clinical questions. To evaluate the implemented IE module and the classifier, the gold-standard annotations and answers were developed manually, and the results of the implemented system were compared with the gold standard. The IE model achieved an F-score from 92.40% to 99.59%, and the classifier achieved accuracy from 96.15% to 100%. The application was successfully applied to the various types of narrative clinical reports. It might be applied to the key extraction for other types of cancer patients.

PF.67 The Increased Incidence of Echogenic Lung Lesions – an 18-Year Review from the Wessex Region

IntroductionEchogenic lung lesions (ELL) are a heterogeneous group of lung abnormalities that display a variety of features and are inherently difficult to diagnose and characterise antenatally. Included in this group...

Validation of a lung ultrasound protocol in acute respiratory failure: preliminary results

Patients with acute respiratory failure demand dynamic evaluation and interventions. Lung ultrasound is a bedside technique, very promising in this setting. Previously, Lichtenstein and colleagues proposed an algorithm approach with a diagnostic accuracy of 90.5%, named Bedside Lung Ultrasound in Emergency (BLUE protocol). However, this approach has never been validated in other populations or ultrasound operators. The aim of this study was to evaluate the diagnostic accuracy of the lung ultrasound algorithm (BLUE protocol) in ICU patients admitted with acute respiratory failure.

Tumescent, how do I do it?

Local perivenous anaesthesia has evolved from tumescent anaesthesia which has had a huge impact on liposuction procedures. Perivenous anaesthesia has had a similar effect on peripheral venous surgery. Safety during its application is further enhanced when combined with skilled ultrasound guidance and astute operator awareness.

Reproducibility of ECG-gated Ultrasound Diameter Assessment of Small Abdominal Aortic Aneurysms

No standardised ultrasound procedure to obtain reliable growth estimates for abdominal aortic aneurysms (AAA) is currently available. We investigated the feasibility and reproducibility of a novel approach controlling for a combination of vessel wall delineation and cardiac cycle variation. Prospective comparative study. Consecutive patients (N = 27) with an AAA, attending their 6-month control as part of a medical treatment trial, were scanned twice by two ultrasound operators. Then, all ultrasound recordings were transferred to a core facility and analysed by a third person. The AAA diameter was determined in four different ways: from the leading edge of adventitia on the anterior wall to either the leading edge of the adventitia (method A) or leading edge of the intima (method B) on the posterior wall, with both measurements performed in systole and diastole. Inter-operator reproducibility was ± 3 mm for all methods applied. There was no difference in outcome between methods A and B; likewise, end-diastolic measurement did not improve reproducibility in preference to peak-systolic measurement. The use of a standardised ultrasound protocol including ECG-gating and subsequent off-line reading with minute calliper placement reduces variability. This may be of use in developing protocols to better detect even small AAA growth rates during clinical trials.

SYSTEMS AND METHODS FOR ASSESSING A MEDICAL ULTRASOUND IMAGING OPERATOR'S COMPETENCY

Methods and systems are provided for assessing a medical ultrasound imaging operator's competency. The system includes a console containing a plurality of virtual controls, such as knobs, for simulating a real-life examination of a patient. The images created by the system change dynamically as the different virtual knobs on the console are adjusted. The console provides a certification examination for a medical ultrasound imaging operator. The console also includes a process to assess the medical ultrasound imaging operator's competency. The process determines a plurality of scores in order to assess the competency of the medical ultrasound imaging operator.

Intussusception in children: Comparison between ultrasound diagnosis and operation findings in a tropical developing country

Intussusception is one of the more common causes of intestinal obstruction in children. The diagnosis may be based mainly on clinical features; however, there are no classic signs and symptoms that are common to all cases. This study reports our experience at US diagnosis and operation findings of children with intussusceptions in a tropical developing economy. This was an 8 years retrospective review of intussusceptions in children in a tertiary health facility in a tropical developing country from January 2004 to December 2011. Twenty-five out of 41 children (M:F = 2.2:1) admitted with intussusceptions within the period were studied. The median age was 6.0 ± 5.57 months (range 3 months- 7 years). US positively diagnosed intussusceptions in 20 (80%) cases. US can increase diagnostic confidence in intussusceptions.

Virtual Guidance as a Tool to Obtain Diagnostic Ultrasound for Spaceflight and Remote Environments

With missions planned to travel greater distances from Earth at ranges that make real-time two-way communication impractical, astronauts will be required to perform autonomous medical diagnostic procedures during future exploration missions. Virtual guidance is a form of just-in-time training developed to allow novice ultrasound operators to acquire diagnostically-adequate images of clinically relevant anatomical structures using a prerecorded audio/visual tutorial viewed in real-time. Individuals without previous experience in ultrasound were recruited to perform carotid artery (N = 10) and ophthalmic (N = 9) ultrasound examinations using virtual guidance as their only training tool. In the carotid group, each untrained operator acquired two-dimensional, pulsed and color Doppler of the carotid artery. In the ophthalmic group, operators acquired representative images of the anterior chamber of the eye, retina, optic nerve, and nerve sheath. Ultrasound image quality was evaluated by independent imaging experts. Of the studies, 8 of the 10 carotid and 17 of 18 of the ophthalmic images (2 images collected per study) were judged to be diagnostically adequate. The quality of all but one of the ophthalmic images ranged from adequate to excellent. Diagnostically-adequate carotid and ophthalmic ultrasound examinations can be obtained by previously untrained operators with assistance from only an audio/video tutorial viewed in real time while scanning. This form of just-in-time training, which can be applied to other examinations, represents an opportunity to acquire important information for NASA flight surgeons and researchers when trained medical personnel are not available or when remote guidance is impractical.

Causes of discordant or negative ultrasound of parathyroid glands in treatment naïve patients with primary hyperparathyroidism

ObjectivesTo describe causes of discordant or negative parathyroid ultrasound and to assess factors influencing them. Materials and methodsRetrospective review of patients who underwent parathyroidectomy between 2000 and 2012 was done. Imaging findings were compared with operative findings and pathology to identify discrepant (n=60; 32 negative, 28 incorrect) parathyroid ultrasounds. ResultsFifty (83.3%) patients had parathyroid adenoma, of which 10 (16.6%) were ectopic and three were double adenomas; 8 (13.3%) had multigland hyperplasia and two had parathyroid carcinoma. Discrepant reports were due to incorrect localisation in 8 (13.3%); difficulty in differentiating thyroid from parathyroid lesion in 12 (20%); large and small size in two and three patients, respectively; overcall in 5 (8.3%) and satisfaction of search in 7 (11.7%) patients. There was significant correlation between presence of multi-nodular goitre and incorrect reports (χ2=4.112, p=0.04). Experience of ultrasound operators performing initial and second look ultrasound was significantly different (p<0.0001). Second look ultrasound was concordant with surgical findings in 39(65%) patients; 21 (66%) patients with initially negative ultrasound and four out of five extra-mediastinal ectopic lesions. Ten patients with negative initial ultrasound had elongated parathyroid lesion. Scintigraphy was concordant in 44 (73.3%) patients and nine were ectopic. ConclusionSecond look ultrasound performed by experienced operator for negative or discordant initial ultrasound of parathyroid is a useful strategy which will improve the accuracy of parathyroid ultrasound. Being able to differentiate thyroid from parathyroid lesion is a factor which will influence performance of parathyroid ultrasound.

Clinical research of retroperitoneal laparoscopic intervention ultrasound aided positioning in the treatment of adult renal cyst

Objective To explore the clinical value of retropentoneal laparoscopic interventon ultrasound aided positioning in the treatment of adult renal cyst.Methods The operating information of 327 patients with adult renal cyst was analyzed retrospectively,in which 239 cases applied the retroperitoneal laparoscopic intervention ultrasound aided positioning treatment( interventional ultrasound group),88 cases applied retroperitoneal laparoscopic intervention without ultrasound assisted positioning operation treatment ( non interventional ultrasound group).Results The operation time of the interventional ultrasound group was (3.61 ± 0.49) h,and was longer than that of the non interventionul ultrasound group[ ( 3.27 ± 0.71 ) h ] ( t =4.89,P ＜ 0.05 ).The postoperative indwelling drainage tube time,postoperative renal length of the interventional ultrasound group was (2.24 ± 0.58 ) d,( 12.01 ± 4.25 ) cm respectively,and was shorter than that of the non interventional ultrasound group[ (3.59 ±2.27 ) d、( 13.39 ±5.21 )cm ] ( t =8.49,2.45,all P ＜ 0.05 ).A postoperative ＞ 1 cm cyst residual amount of ultrasound in the intervention group was significantly less than the non-ultrasound in the intervention group (x2 =10.36,P ＜ 0.05 ).Conclusion The ultrasound assisted positioning operation could determine deep cysts position better,so the retroperitoneal laparoscopic intervention ultrasound aided positioning in the treatment of adult renal cyst could reduce cyst of residual risk,and also prevent serious vascular and renal collecting system injury and improve the operation safety. Key words: Polycystic kidney; Posterior approach; Laparoscopic

Prospective evaluation of the IOTA logistic regression model LR2 for the diagnosis of ovarian cancer

To assess the accuracy of the IOTA logistic regression model LR2 for the diagnosis of ovarian cancer. This was a prospective single-center study of women with an ultrasound diagnosis of an adnexal tumor. They were all examined by a single Level-II ultrasound operator, who had received training in the systematic examination of ovarian tumors in accordance with the IOTA guidelines. In all women the likelihood of the adnexal lesion being malignant was calculated using the IOTA LR2 model. All women underwent surgery within 120 days of ultrasound examination and the ultrasound findings were compared with operative findings and the final histological diagnosis. One hundred and twenty-four women were included in the final analysis. The mean age was 53.2 (range, 20-91) years and 61/124 (49.2%) women were postmenopausal. 66/124 (53.2%) women had malignant lesions on postoperative histological examination. The IOTA LR2 model had a sensitivity of 97.0% (95% CI, 89.5-99.6%) and a specificity of 69.0% (95% CI, 55.5-80.5%). The area under the receiver-operating characteristics curve was 0.93 (SE, 0.022; 95% CI, 0.89-0.97), which was not significantly different from 0.92 (SE, 0.018) reported in the original study (P > 0.05). When evaluated prospectively, the accuracy of the IOTA LR2 model was similar to that reported in the original study.

Removal of Organic Matter and Ammonia Nitrogen in Azodicarbonamide Wastewater by a Combination of Power Ultrasound Radiation and Hydrogen Peroxide

A simple and efficient sonochemical method was developed for the degradation of organic matter and ammonia nitrogen in azodicarbonamide wastewater. The effects of initial pH, ultrasound format and peripheral water level on the sonolysis of hydrazine, urea, COD and ammonia nitrogen were investigated. It is found that the initial pH has a significant influence on the degradation of hydrazine and ammonia nitrogen, whereas this impact to urea is relatively small. It also shows that a noticeable enhancement of ammonia nitrogen removal could be achieved in a proper intermittent ultrasound operation mode, i.e., 1/1 min on/off mode. The height difference between the peripheral water level and the inner water level of the flask affects the efficiency of ultrasonic treatment as well.