Can Ultrasound Propagate in the Joint Space of a Human Knee?

A large body of evidence supports the principle that the use of low-intensity pulsed ultrasound with a frequency of 1.5 MHz can reduce fracture healing time. It is hypothesized that similar therapeutic benefits may be achieved in damaged articular cartilage. This study looks specifically at a 22-mm circular ultrasound transducer delivering ultrasound with a frequency of 1.5 MHz. A human cadaver knee was imaged using CT, the resulting images were used to help map a number of hydrophone positions in the joint from which measurements were taken. The experimental results suggest that at best there is a 30-mm window in which to place the ultrasound transducer for ultrasound to propagate through the joint space. In terms of a clinical device delivering an I(SATA) of 30 mW cm(-2) to anterior regions of the joint, the I(SATA) in posterior regions will at best be in the region of 10 mW cm(-2). The clinical implications of this are not known and require further investigation.     

Can Ultrasound of the Tibial Nerve Detect Diabetic Peripheral Neuropathy?: A cross-sectional study

OBJECTIVE

Peripheral nerve imaging by portable ultrasound (US) may serve as a noninvasive and lower-cost alternative to nerve conduction studies (NCS) for diagnosis and staging of diabetic sensorimotor polyneuropathy (DSP). We aimed to examine the association between the size of the posterior tibial nerve (PTN) and the presence and severity of DSP.

RESEARCH DESIGN AND METHODS

We performed a cross-sectional study of 98 consecutive diabetic patients classified by NCS as subjects with DSP or control subjects. Severity was determined using the Toronto Clinical Neuropathy Score. A masked expert sonographer measured the cross-sectional area (CSA) of the PTN at 1, 3, and 5 cm proximal to the medial malleolus.

RESULTS

Fifty-five patients had DSP. The mean CSA of the PTN in DSP compared with control subjects at distances of 1 (23.03 vs. 17.72 mm²; P = 0.004), 3 (22.59 vs. 17.69 mm²; P < 0.0001), and 5 cm (22.05 vs. 17.25 mm²; P = 0.0005) proximal to the medial malleolus was significantly larger. Although the area under the curve (AUC) for CSA measurements at all three anatomical levels was similar, the CSA measured at 3 cm above the medial malleolus had an optimal threshold value for identification of DSP (19.01 mm²) with a sensitivity of 0.69 and a specificity of 0.77 by AUC analysis.

CONCLUSIONS

This large study of diabetic patients confirms that the CSA of the PTN is larger in patients with DSP than in control subjects, and US is a promising point-of-care screening tool for DSP.Ultrasound (US) for nerve imaging is increasingly used by various medical specialties for both diagnostic and therapeutic purposes (1,2). Modern US machines permit real-time, point-of-care imaging of nerves and their surrounding structures with high fidelity and without patient discomfort or radiation exposure. One promising application of US technology of interest to internists, anesthesiologists, and surgeons may be its ability to rapidly and reliably identify peripheral neuropathy, which traditionally requires resource-intensive nerve conduction studies (NCS) for formal diagnosis (3,4). Preliminary data signal a direct relationship that is independent of BMI, age, height, or weight between the presence of diabetic neuropathy and a greater cross-sectional area (CSA) of peripheral nerves as visualized by US (5,6). However, these previously published studies are limited by small sample sizes and cannot offer predictive values for US as a diagnostic test (6–8). In this larger observational study, we aimed to determine whether US can reliably detect the presence and severity of diabetic sensorimotor polyneuropathy (DSP). We hypothesized that the CSA of the posterior tibial nerve (PTN) as measured by US is higher in diabetic patients with DSP compared with diabetic patients without DSP.     

Can Ultrasound in Combination with Virtual Touch Imaging Quantification Predict the Dignity of a Parotid Tumor?

Pre-operative evaluation of a parotid gland tumor is crucial in guiding treatment. This study evaluates the diagnostic performance of B-mode ultrasound in combination with Virtual Touch imaging quantification (VTIQ) in the assessment of parotid lesions. A prospective study of 268 patients with parotid lesions was conducted. Pre-operative ultrasound findings and VTIQ data were compared against histologic results. Ill-defined margins on ultrasound were associated with a significantly higher risk of malignancy (odds ratio [OR] = 1224.0, 95 % confidence interval [CI]: 151.8–9872.7). Faster mean shear waves on VTIQ (OR = 1.81, 95% CI: 1.47–2.23, per 1 m/s increase) and an area with shear wave velocity >6.0 m/s involving >70 % of the lesion (OR = 19.80, 95 % CI: 6.22–63.07) were associated with higher risk of malignancy. Addition of VTIQ to routine pre-operative B-mode ultrasound can provide supplemental information on the dignity of a parotid tumor, allowing for peri-operative procedural optimization.     

Can Ultrasound Be Used to Improve the Palpation Skills of Physicians in Training? A Prospective Study

Background

Accurate diagnosis of musculoskeletal disorders relies heavily on the physical examination, including accurate palpation of musculoskeletal structures. The literature suggests that there has been a deterioration of physical examination skills among medical students and residents, in part due to increased reliance on advanced imaging. It has been shown that knowledge of musculoskeletal anatomy and physical examination skills improve with the use of ultrasound; however, the literature is limited.

Ultrasound Improves the Delivery and Therapeutic Effect of Nanoparticle-Stabilized Microbubbles in Breast Cancer Xenografts

Compared with conventional chemotherapy, encapsulation of drugs in nanoparticles can improve efficacy and reduce toxicity. However, delivery of nanoparticles is often insufficient and heterogeneous because of various biological barriers and uneven tumor perfusion. We investigated a unique multifunctional drug delivery system consisting of microbubbles stabilized by polymeric nanoparticles (NPMBs), enabling ultrasound-mediated drug delivery. The aim was to examine mechanisms of ultrasound-mediated delivery and to determine if increased tumor uptake had a therapeutic benefit. Cellular uptake and toxicity, circulation and biodistribution were characterized. After intravenous injection of NPMBs into mice, tumors were treated with ultrasound of various pressures and pulse lengths, and distribution of nanoparticles was imaged on tumor sections. No effects of low pressures were observed, whereas complete bubble destruction at higher pressures improved tumor uptake 2.3 times, without tissue damage. An enhanced therapeutic effect was illustrated in a promising proof-of-concept study, in which all tumors exhibited regression into complete remission.     

Ultrasound evaluation of the fetal heart: Is it possible?

Ultrasound evaluation of the fetal heart can be performed. Knowledge of the embryology, anatomy, and function of the heart have led us to understand the pathophysiology of congenital heart disease. In this review we discuss the indications as well as some basic principles of fetal echocardiography.     

Can acupuncture ease the symptoms of menopause?

In a randomized, 2-group clinical study, acupuncture was used for the relief of menopausal hot flushes, sleep disturbances, and mood changes. The experimental acupuncture treatment consisted of specific acupuncture body points related to menopausal symptoms. The comparison acupuncture treatment consisted of a treatment designated as a general tonic specifically designed to benefit the flow of Ch'i (energy). Results from the experimental acupuncture treatment group showed a decrease in mean monthly hot flush severity for site-specific acupuncture. The comparison acupuncture treatment group had no significant change in severity from baseline over the treatment phase. Sleep disturbances in the experimental acupuncture treatment group declined over the study. Mood changes in both the experimental acupuncture treatment group and the comparison acupuncture treatment group showed a significant difference between the baseline and the third month of the study. Acupuncture using menopausal-specific sites holds promise for nonhormonal relief of hot flushes and sleep disturbances.     

Does Probe Frequency Influence Diagnostic Accuracy in Newborn Hip Ultrasound?

Ultrasonography of the hip has gained wide acceptance as reliable method for diagnosing developmental hip dysplasia in infants. This blinded study was conducted to investigate the influence of two linear probes with different frequency on diagnostic accuracy and reproducibility. In 206 consecutive newborns, the bony roof angle (α-angle) and cartilage roof angle (β-angle) were assessed by three investigators according to Graf. The hips were measured twice both with a 7.5 MHz and a 12 MHz linear transducer (Sonoline G60S^® ultrasound system; Siemens, Erlangen, Germany). Each investigator evaluated his sonograms 6 weeks later. Depending on the mean values for α-angle and β-angle, the hips were classified. Reproducibility of the Graf classification was not found to be influenced. In two of three investigators, we observed significant improvement concerning variation of the β-angle with the 12 MHz probe. The use of high-resolution transmitters may improve diagnostic accuracy in ultrasonography of the newborn’s hip.     

Can early hemodialysis affect the outcome of the ingestion of glyphosate herbicide?

The ingestion of small amounts of glyphosate herbicide usually causes only mild symptoms. However, when large volumes of concentrates are ingested intentionally, it can generate potentially fatal symptoms that are refractory to treatment. It also is well known that the treatment for glyphosate poisoning is primarily of a supportive nature. We report two patients who intentionally ingested glyphosate herbicide, and both exhibited cardiovascular collapse and complicated renal failure despite the use of aggressive supportive therapy. Hemodialysis was conducted and the results were satisfactory; both patients were discharged without any sequelae. After analyzing these cases, we suggest that hemodialysis might have contributed to the favorable outcomes of our patients, and that there are several mechanisms that might justify the use of hemodialysis in these patients. In conclusion, physicians may wish to consider the early use of hemodialysis to improve the prognosis of patients exhibiting refractory hypotension and oliguria, despite vigorous supportive treatment in glyphosate herbicide intoxication.     

Can Ultrasound Enable Efficient Intracellular Uptake of Molecules? A Retrospective Literature Review and Analysis

Most applications of therapeutic ultrasound (US) for intracellular delivery of drugs, proteins, DNA/RNA and other compounds would benefit from efficient uptake of these molecules into large numbers of cells without killing cells in the process. In this study we tested the hypothesis that efficient intracellular uptake of molecules can be achieved with high cell viability after US exposure in vitro. A search of the literature for studies with quantitative data on uptake and viability yielded 26 published papers containing 898 experimental data points. Analysis of these studies showed that just 7.7% of the data points corresponded to relatively efficient uptake (>50% of cells exhibiting uptake). Closer examination of the data showed that use of Definity US contrast agent (as opposed to Optison) and elevated sonication temperature at 37°C (as opposed to room temperature) were associated with high uptake, which we further validated through independent experiments carried out in this study. Although these factors contributed to high uptake, almost all data with efficient uptake were from studies that had not accounted for lysed cells when determining cell viability. Based on retrospective analysis of the data, we showed that not accounting for lysed cells can dramatically increase the calculated uptake efficiency. We further argue that if all the data considered in this study were re-analyzed to account for lysed cells, there would be essentially no data with efficient uptake. We therefore conclude that the literature does not support the hypothesis that efficient intracellular uptake of molecules can be achieved with high cell viability after US exposure in vitro, which poses a challenge to future applications of US that require efficient intracellular delivery.     

Therapeutic Effects of Focused Ultrasound on Expression of Notch1, C-Fos and Transforming Growth Factor-β3 in Vulvar Skin of SD Rats with Vulvar Lichen Simplex Chronicus

The purpose of this study was to investigate the therapeutic effects of focused ultrasound on the expression of notch1, c-fos and transforming growth factor-β3 (TGF-β3) in genital skin of SD rats with vulvar lichen simplex chronicus (LSC). Fifty-six female SD rats with LSC were randomly divided into therapy and sham groups. The therapy group was exposed to focused ultrasound. The sham group received the same therapy with an instrument that had no power output. Four wk after a singly focused ultrasound therapy, histologic analyses revealed that recovered SD rats accounted for 75% of SD rats in the therapy group and 10.7% in the sham group. Total collagen fiber density in the superficial layer of dermis in the therapy group was significantly lower than that in the sham group. Notch1 and c-fos protein expression in the therapy group was significantly lower than that in the sham group, with the opposite effect present for TGF-β3. Focused ultrasound therapy may inhibit superficial collagen fibrosis in the dermis by affecting expression of notch1, c-fos and TGF-β3 in vulvar skin tissue and consequently reduce the recurrence rate of LSC.     

Can the Death of a Child Be Good?

Fifty-four thousand children die each year despite the advances in care for children with acute and chronic illnesses. Demands for improved palliative and end-of-life care for children exist. Good death is a concept frequently used in the adult hospice movement. However, how can the death of a child be good? Analysis of good death can assist pediatric nurses to understand the concept and provide a framework for nurses in the clinical and research arenas to work together to develop and provide evidence-based, developmentally appropriate care for dying children and their families.     

Can the Contrast-Enhanced Ultrasound Washout Rate Be Used to Predict Microvascular Invasion in Hepatocellular Carcinoma?

The objective of this study was to investigate use of the washout rate of hepatocellular carcinoma on contrast-enhanced ultrasound (CEUS) for pre-operative determination of the presence of microvascular invasion. The study included 271 patients who underwent liver resection for hepatocellular carcinoma between April 2008 and December 2012, and were examined with contrast-enhanced ultrasound before surgery. Patients were followed up at 3-mo intervals for 3 y. Four washout patterns were classified according to the start time of washout: rapid, portal, delayed and slow. Rapid washout, presence of two or more tumors and tumor size ≥5 cm were identified as independent pre-operative predictors of microvascular invasion on multivariate analysis. Recurrence rates for patients with none, one, two or three predictors were 22.6%, 34.7%, 57.6% and 75.0%, respectively. In combination with tumor number and tumor size, contrast-enhanced ultrasound washout rate may have a role in identifying hepatocellular carcinoma patients with microvascular invasion.