Role of ultrasound in the active management of osteogenesis during compression–distraction osteosynthesis in children

Purpose

To determine whether distraction-induced regeneration (DR) can be optimized based on consecutive ultrasound findings during the course of compression–distraction osteosynthesis (CDO).

Materials and methods

Sixty-nine children ranging in age from 2 weeks to 15 years with congenital (37 patients) or acquired (32 patients) microgenia were treated with CDO. Radiological diagnostic studies included orthopantomography (OPG) and ultrasonography (US). The patients were divided into two groups: in group I a standard distraction rate (SDR) (1 mm/day) was used (33 patients, 47.8%); in group II (36 patients, 52.2%) individual distraction rates (IDR) were used based on US findings.

Results

DR was classified as normotrophic, hypertrophic, or hypotrophic based on US findings. In group I, 11 (33.3%) of the patients presented normotrophic DR, 8 (24.2%) had hypertrophic DR, and in 14 (42.4%), the DR was hypotrophic. In group II, all patients presented normotrophic DR at the end of the treatment.

Conclusion

US offers a unique opportunity to study DR development, and the results can be used to actively manage and optimize the osteogenesis process during mandibular CDO in children.     

Are pocket sized ultrasound devices sufficient in the evaluation of lung ultrasound patterns and aeration scoring in pulmonary ICU patients?

Journal of Clinical Monitoring and Computing - Lung ultrasound (LUS) is a practical diagnostic tool for several lung pathologies. Pocket sized USG devices (PSUDs) are more affordable, accessible,...     

Analysis of ultrasound fields in cell culture wells for in vitro ultrasound therapy experiments

Ultrasound is an established therapy method for bone fracture healing, hyperthermia and the ablation of solid tumors. In this new emerging field, ultrasound is further used for microbubble-enhanced drug delivery, gene therapy, sonoporation and thrombolysis. To study selected therapeutic effects in defined experimental conditions, in vitro setups are designed for cell and tissue therapy. However, in vitro studies often lack reproducibility and the successful transfer to other experimental conditions. This is partly because of the uncertainty of the experimental conditions in vitro. In this paper, the ultrasound wave propagation in the most common in vitro ultrasound therapy setups for cell culture wells is analyzed in simulations and verified by hydrophone measurements. The acoustic parameters of the materials used for culture plates and growth media are determined. The appearance and origin of standing waves and ring interference patterns caused by reflections at interfaces is revealed in simulations and measurements. This causes a local maximal pressure amplitude increase by up to the factor of 5. Minor variations of quantities (e.g., growth medium volume variation of 2.56%) increase or decrease the peak rarefaction pressure at a cell layer by the factor of 2. These pressure variations can affect cell therapy results to a large extent. A sealed cell culture well submersed in a water bath provides the best reproducibility and therefore promises transferable therapy results.     

Where's the tube? Evaluation of hand-held ultrasound in confirming endotracheal tube placement

INTRODUCTION: The diagnosis of endotracheal tube (ETT) mal-position may be delayed in extreme environments. Several methods are utilized to confirm proper ETT placement, but these methods can be unreliable or unavailable in certain settings. Thoracic sonography, previously utilized to detect pneumothoraces, has not been tested to assess ETT placement. HYPOTHESIS: Thoracic sonography could correlate with pulmonary ventilation, and thereby, help to confirm proper ETT placement. METHODS: Thirteen patients requiring elective intubation under general anesthesia, and data from two trauma patients were evaluated. Using a portable, hand-held, ultrasound (PHHU) machine, sonographic recordings of the chest wall visceral-parietal pleural interface (VPPI) were recorded bilaterally in each patient during all phases of airway management: (1) pre-oxygenation; (2) induction; (3) paralysis; (4) intubation; and (5) ventilation. RESULTS: The VPPI could be well-imaged for all of the patients. In the two trauma patients, right mainstem intubations were noted in which specific pleural signals were not seen in the left chest wall VPPI after tube placement. These signs returned after correct repositioning of the ETT tube. In all of the elective surgery patients, signs correlating with bilateral ventilation in each patient were imaged and correlated with confirmation of ETT placement by anesthesiology. CONCLUSIONS: This report raises the possibility that thoracic sonography may be another tool that could be used to confirm proper ETT placement. This technique may have merit in extreme environments, such as in remote, pre-hospital settings or during aerospace medical transports, in which auscultation is impossible due to noise, or capnography is not available, and thus, requires further scientific evaluation.     

Assessment of the extension and the inflammatory activity in Crohn’s disease: comparison of ultrasound and MRI

Objective  The purpose of this prospective study was twofold: to examine the efficacy of MRI and sonography in the assessment of Crohn’s disease (CD) activity in comparison with clinical scoring and biologic tests and to compare both techniques in the evaluation of extension and transmural complications. Material and methods  Thirty patients with histologically proven Crohn’s disease were prospectively examined the same day first with sonography and after MRI. Sonographic exam included evaluation of bowel wall thickness, vascularity pattern, and perienteric changes. Thirty minutes prior to MRI imaging, patients were given 250 mL of dilute sodium phosphate solution and additional 750 mL of water orally. MRI images evaluation included bowel wall thickening, bowel wall enhancement, and perienteric changes. The gastrointestinal tract was divided into five segments. Findings and extension of the both techniques were verified by means of barium studies, surgery, or/and colonoscopy. The sonographic and MR findings were compared with clinical and laboratory data. Results  About 53 of 119 (45%) bowel segments showed pathological changes in gold standard tests. Sonography was superior to MRI in the localization of affected bowel segments (sensitivity: US 91%; MRI 83%; intertechniques agreement, kappa: 0.905) and in recognizing transmural complications (sensitivity: US 80%; MRI 72%), although significant differences were not found (p > 0.05). A statistically significant correlation between color Doppler flow and MR bowel wall enhancement (segment-by-segment analysis and per patient analysis; p > 0.5), and between perienteric changes in both techniques (p > 0.5) were found. Wall thickness measured on sonography was significantly greater in the group of patients with clinical activity (p = 0.023) or with clinical-biologic activity (p = 0.024). Grades of hyperemia and MR contrast enhancement of patients with clinical–biologic activity was higher than in patients without clinical–biologic activity (p = 0.019; p = 0.023). Conclusion  In summary, both ultrasound and MRI are sensitive to localize the affected bowel segments and to detect transmural complications in patients with Crohn’s disease. A significant correlation between color Doppler flow and bowel wall enhancement on MRI was found. Sonographic wall thickness, color Doppler flow, and bowel wall enhancement on MRI are related with clinical or biologic activity.     

High-resolution ultrasound imaging of human skin in vivo by using three-dimensional ultrasound microscopy

Observing the morphology of human skin is important in the diagnosis of skin cancer and inflammation and in the assessment of skin aging. High-frequency ultrasound imaging provides high spatial resolution of the deep layers of the skin, which cannot be visualized by optical methods. The objectives of the present study were to develop a three-dimensional (3-D) ultrasound microscope and to observe the morphology of normal human skin in vivo. A concave polyvinylidene fluoride transducer with a central frequency of 120 MHz was excited using an electric pulse generated by semiconductor switching. The transducer was scanned two-dimensionally by using two linear motors on the region-of-interest and the ultrasonic reflection was digitized with 2-GHz sampling. Consecutive B-mode images perpendicular to the skin surface were reconstructed to generate multiplanar reconstructed images and 3-D volume-rendering images clearly showing microstructures such as sebaceous glands and hair follicles. The 3-D ultrasound microscope could be used to successfully image the morphology of human skin noninvasively and may provide important information on skin structure.     

Prolapse operation--also of help in urinary tract infections?

Pelvic support defects are frequently associated with chronic and recurrent urinary tract infections. This is due to common etiological factors (hormone-related atrophy, neurogenic diseases, metabolic disorders) and to direct mechanical effects exerted by the descensus on the urethra function (kinking that occurs with miction disorders and an increase in the residual urine with large cystoceles or stress incontinence and urgency with large urethroceles). The therapy should begin conservatively and address all possible etiological factors. Fundamentals of conservative therapy include estrogens, pelvic floor training, pessaries, drinking and micturition training and therapy and prevention of ascending infections [1]. When conservative therapy does not achieve either a cure or a satisfactory degree of improvement within a few months, surgical treatment should usually be recommended. In this case, modern surgical methods are preferred which seek to achieve both an anatomical as well as a functional restoration, i.e. continence, a good degree of bladder emptying and defecation as well as painless coitus.     

Contrast-enhanced ultrasound in planning thermal ablation of liver metastases: Should the hypervascular halo be included in the ablation volume?

Introduction

Liver metastases often exhibit a hypervascular halo during the arterial phase of contrast-enhanced ultrasonography (CEUS). This finding has no correlates on baseline gray-scale imaging, and it has never been characterized. The aim of this study was to identify the features of this halo and determine whether it should be included in the ablation volume during thermal ablation procedures.

Materials and methods

We prospectively enrolled 25 patients referred to our department for thermal ablation of liver metastases. Before treatment all patients underwent CEUS, and the maximum diameter of the metastatic lesion was measured before administration of the ultrasound contrast agent and during the arterial and portal venous phases of the contrast contrast-enhanced study. Maximum diameters in the different vascular phases were compared with the Turkey–Kramer test. Two biopsies were obtained from each lesion with a 21-gauge needle: 1) one from the center of the metastasis to confirm the diagnosis and 2) one from the hypervascular peripheral halo identified in the arterial phase at CEUS.

Results

The mean (±standard deviation) maximum lesion diameter was 2.67 ± 1.2 cm before contrast agent injection, 3.50 ± 1.4 cm during the arterial phase, and 2.71 ± 1.2 cm during the venous phase. The difference between maximum diameters measured before contrast enhancement and in the arterial phase was highly significant (mean: 0.84 ± 0.45 cm, p < 0.0001). Histological examination of halo specimens revealed inflammatory infiltrates with no evidence of tumor infiltration in 24/25 (96%) cases and normal hepatic parenchymal tissue in the 25th specimen.

Discussion

The hypervascular halo surrounding liver metastases during the arterial phase of CEUS represents a chronic inflammatory infiltrate, not tumor infiltration. However, since chronic inflammation appears to promote neovascularization and the production of tumoral growth factors, it seems wise to include the hypervascular halo in the intended-to-treat volume when planning the ablation procedure.     

Ultrasound and light: friend or foe? On the role of intravascular ultrasound in the era of optical coherence tomography

More than 20 years after its introduction, intravascular ultrasound (IVUS) has outlived many other intracoronary techniques. IVUS was useful to solve many interventional problems and assisted us in understanding the dynamics of atherosclerosis. It serves as an established imaging endpoint in large progression-regression trial and as an important workhorse in many catheterization laboratories. Nowadays, increasingly complex lesions are treated with drug-eluting stents. The application of IVUS during such interventions can be very useful. Recently, optical coherence tomography (OCT), a light-based imaging technique, has entered the clinical arena. The “omnipresence” of OCT during scientific sessions and live courses with PCI may raise in many the question: Does IVUS have a future in the “era of OCT”? Three review articles, highlighted by this editorial, demonstrate the broad spectrum of current IVUS applications and underline the significant role of IVUS during the last two decades. OCT, the much younger technique, still has to prove its value. Yet OCT is likely to take over some of the current indications of IVUS as a research tool. In addition, OCT is currently gaining clinical significance for stent optimization during complex interventional procedures. Nevertheless, there is little doubt that IVUS still has a major role in studies on coronary atherosclerosis and for guidance of coronary stenting. Thus, ultrasound and light—are they friend or foe? In fact, both methods are good in their own rights. They are complementary rather than competitive. Moreover, in combination, at least for certain indications, they could be even better.     

Are falls in people with multiple sclerosis related to the severity of urinary disorders?

BackgroundLower urinary tract symptoms (LUTSs), especially overactive bladder, are frequent in people with multiple sclerosis (PwMS). Urinary urgency and urge urinary incontinence could lead to precipitation and thus could increase the risk of falling in these individuals.ObjectiveWe aimed to assess the association between severity of LUTSs and risk of falling in PwMS.MethodsPwMS with LUTSs were recruited in a neuro-urology department. Participants were asked about the number of falls in the past 3 months and their circumstances. Severity of LUTSs was assessed by the Urinary Symptoms Profile (USP) score, and individuals were classified as with or without urinary incontinence.ResultsThis cross-sectional study included 154 patients (69% women); the mean (SD) age was 50.1 (11.5) years and median EDSS was 5 (interquartile range 3–6). Overall, 20 (13%) patients reported one fall during the past 3 months, and 43 (28%) reported at least 2 falls. Only 9 (6%) patients reported a fall on the way to the toilet, 6 during a urinary urgency. No link was found between falls and urinary incontinence (P = 0.71), type or severity of urinary symptoms (overactivity, voiding dysfunction or stress incontinence, P > 0.05). Falls on the way to the bathroom was associated with high USP score related to overactive bladder (P = 0.03) and severe nocturia (> 2 nocturnal micturitions) (P < 0.01). Falling at night was also associated with severe nocturia (P < 0.001).ConclusionsThe severity of LUTSs and presence of urinary incontinence do not appear related to the risk of falling in PwMS and urinary disorders but rather to the specific risk of falling on the way to the bathroom. Severe nocturia increases the risk of falling at night. Further studies are needed to assess the impact of LUTS treatment on the risk of falling. ClinicalTrials.gov (NCT04338646).     

The effectiveness of “Protex” for disinfection of the ultrasound probe

The aim of this study was to evaluate the effectiveness of “Protex” (Parker; Fairfield, NJ, USA) for disinfection of ultrasound probes. We examined bacterial contamination on ultrasound probes that were wiped with a plain paper towel, with a plain and an ethanol-soaked paper towel, or with a plain and Protex-soaked paper towel. The plain paper towel was used to remove the gel, and was contaminated by large numbers of bacteria, but the use of ethanol-soaked paper towels and that of paper towels soaked in Protex? broad-spectrum disinfectant (Parker: Fairfield, NJ, USA) reduced those numbers markedly.     

An in vivo validation of the application of acoustic radiation force to enhance the diagnostic utility of molecular imaging using 3-d ultrasound

For more than a decade, the application of acoustic radiation force (ARF) has been proposed as a mechanism to increase ultrasonic molecular imaging (MI) sensitivity in vivo. Presented herein is the first noninvasive in vivo validation of ARF-enhanced MI with an unmodified clinical system. First, an in vitro optical-acoustical setup was used to optimize system parameters and ensure sufficient microbubble translation when exposed to ARF. 3-D ARF-enhanced MI was then performed on 7 rat fibrosarcoma tumors using microbubbles targeted to α_vβ₃ and nontargeted microbubbles. Low-amplitude (<25 kPa) 3-D ARF pulse sequences were tested and compared with passive targeting studies in the same animal. Our results demonstrate that a 78% increase in image intensity from targeted microbubbles can be achieved when using ARF relative to the passive targeting studies. Furthermore, ARF did not significantly increase image contrast when applied to nontargeted agents, suggesting that ARF did not increase nonspecific adhesion.     

How can the variability in ultrasound measurement of intima-media thickness be reduced? Studies of interobserver variability in carotid and femoral arteries

A critical component in scientific studies of most biological variables is the variation or error in measurements which leads to non-identical results of repeated measurements from the same subject. The aim of this study was to investigate whether the interobserver error (s) in measurement of intima-media thickness (IMT) in carotid and femoral arteries could be decreased if the mean value obtained using two ultrasound images from each of the right and left arteries was used in the analyses instead of the mean value obtained using images from only the right artery. In addition, we wished to evaluate two different reading procedures, one based on manual tracing of echo interfaces and the other on automated edge detection. In a methodological study, 50 subjects were examined with ultrasound twice in the same day by two independent laboratory technologists. The ultrasound images were analysed in two ways: using a computerized manual tracing analysing system and an automated analysing system. When both right and left carotid arteries were examined (manual reading), the interobserver error was smaller than that determined for the examination of only the right artery, for IMT_mean in both the common carotid artery (P = 0·06) and the carotid artery bulb (P<0·05). The interobserver error was also significantly smaller for double-sided vs. one-sided examination with automated reading of IMT_mean in the common carotid artery (P<0·01) and in the carotid artery bulb (P<0·01). The coefficient of variation (CV) for measurement in the common carotid artery decreased from 8·6% (one-sided, manual reading) to 5·3% (double-sided, automated reading). The interobserver error in measurement of IMT in the common femoral artery did not improve by examination of both right and left arteries. The results from this study show that the interobserver errors in measurement of IMT can be decreased by using ultrasound images from both the right and the left carotid arteries, and that the use of an automated analysing system greatly simplifies the reading of ultrasound images with sustained low variability.     

Contrast enhanced ultrasound in the liver using low mechanical index--what is the difference?

Echo-enhancing agents (EEA), also known as ultrasound contrast media, have improved the diagnostic potential of gastroenterologic ultrasound within the last years. Initially used to increase color-Doppler signals the potential to use harmonic waves being generated by the use of EEAs was established later. The effect was based upon the distraction of the EEA bubbles and the resulting pseudo-Doppler signal, the exam was carried out with high ultrasound energy and intermittent switching on and off of the ultrasound beam. Using this effect in real-time during continuous scanning is possible since the introduction of new EEAs with a flexible shell. This flexible shell oscillates during the scan process emitting harmonic signals. This new technology opens new possibilities for the detection of liver tumors including the possible characterisation. The detection rate for liver metastases can be increased by app. 40 % with this new technology. Correct sonographic characterisation of liver tumors can be achieved in nearly 100 % more cases.     

High-frequency ultrasound for in vivo measurement of colon wall thickness in mice

Mouse models are becoming increasingly important in the study of molecular mechanisms of colorectal disease and in the development of novel therapeutics. To enhance this phase of preclinical research, cost-effective, easy to use noninvasive imaging is required to detect and monitor changes in the colon wall associated with disease pathology. This study investigated the feasibility of using 40-MHz (high frequency) B-mode ultrasound (HF-US) to image the normal mouse colon and measure its thickness in vivo by establishing a robust imaging protocol and conducting a blinded comparison of colon wall thickness (CWT) measurement between and within operators. The in vivo and ex vivo appearance of mouse colon under HF-US revealed distinct patterns. Colon wall thickness was reproducibly and accurately measured using HF-US compared with histology measurement. The technique was more sensitive in detecting changes in CWT in distal than proximal colon as it showed the highest level of inter- and intraoperator reproducibility. Using the protocol described, it is possible to detect changes in thickness of 0.09 mm and 0.25 mm in distal and proximal colon, respectively. In conclusion, HF-US provides an easy to use and noninvasive method to perform anatomical investigations of mouse colon and to monitor changes in CWT.