Stand-off Pad Research Articles

Assessment of ultrasound image quality in a reference phantom using gel and liquid standoff pads

Backgroundand Methods: This paper presents a review of image quality in ultrasound imaging when using gel and liquid standoff pads, compared to imaging without a standoff pad. Imaging metrics assessed are lateral resolution, nearfield target intensity, and contrast to noise ratio of echogenicity targets. Measurements were made with a Canon Aplio i800 ultrasound system on a standardized ultrasound phantom (Computerized Imaging Reference Systems, Inc.), and custom-made agarose phantoms. Two cases are examined: when the ultrasound images are taken with the probe at different heights above the phantom (the normal clinical use-case for standoff pads); and when the ultrasound probe is artificially always placed at the same height above the phantom (allowing for direct image comparison). Results and conclusionThe main differences in the standard clinical use-case were observed in nearfield image intensity, with a mean difference of 22.4 ± 11.1 % between highest and lowest positions. Investigation of probes at the same height above the phantom shows that differences appear to be due primarily due to the height of the probe above the phantom, rather than the pads themselves. Elevational beamwidth was found to be a minimum of 2.2 mm at 25 mm axial depth, and adding a standoff pad can change vessel and cyst visualization due to the elevational beamwidth. This is a useful result to be aware of for clinicians using standoff pads on modern ultrasound systems.

Ultrasound image quality of the carpal tunnel during a pinch grip: effects of coupling media and wrist position

ABSTRACT High quality ultrasound is required for evaluating carpal tunnel dynamics. The purpose of this study was to subjectively assess ultrasound video quality of the carpal tunnel with two commonly used coupling media (coupling gel, 7 mm standoff pad) in two wrist positions (0° neutral, 30° flexion) over the entire time course of a pinch grip. Seventeen participants completed a pinch grip while their carpal tunnel was scanned with ultrasound. The ultrasound videos were graded by two independent reviewers using 10-point scales encompassing median nerve detail, resolution, and total video quality. Intra- and inter-rater reliability were highest for median nerve detail (ICCs>.85). Ultrasound videos in the 0° neutral wrist condition resulted in significantly greater ratings of nerve detail compared to those in 30° wrist flexion. Future studies may benefit from a more customised approach to standoff pad thickness during dedicated analysis of the median nerve in a neutral wrist position.

Treatment of cow manure from exercise pens: A laboratory-scale study of the effect of air injection on conventional and alternative biofilters

Woodchips in stand-off pads for wintering cows have been applied in countries like Ireland and New Zealand. Their primary role is to protect soils by effectively filtering nutrients during wet conditions, while ensuring a healthy and comfortable environment for the cows. The stand-off pad concept has the potential to be adopted in Canada to provide year-long outdoor access to tie-stall dairy cows. The objective of this study was to evaluate the effect of alternative filtering materials and bed aeration under controlled laboratory conditions. Twelve biofilter columns (0.3 m in diameter and 1-m high) were installed in 12 environmentally-controlled chambers (1.2-m wide by 2.4-m long), and divided into four treatments: a bed of conventional woodchips or an alternative mix of organic materials (sphagnum peat moss, woodchips and biochar) with and without aeration (flux rate set at 0.6 m3/min/m2). Approximately 0.6 L of semi-synthetic dairy manure and 1 L of tap water were poured on the biofilters during two experimental periods of 4 weeks, simulating the effect of either winter or summer conditions (room temperature below or over 10 °C) on the retention of nutrients and fecal bacteria. Results showed that the alternative biofilters under both summer and winter conditions were more efficient in removing COD, SS, TN, and NO3–N than conventional biofilters (maximum efficiencies of 97.6%, 99.7%, 96.4%, and 98.4%, respectively). Similarly for E. coli, they achieved a minimum concentration of 1.8 Log10 CFU/100 ml. Conventional biofilters were more efficient for PO4–P removal with a maximum efficiency of 88.2%. Aeration did not have any significant effect under the tested temperature conditions. Additional factors such as media adaptation time as well as aeration flow during this period should be considered.

Preliminary Experience in Transducer Preparation for Intraoral Imaging.

Intraoral scanning must meet a stringent infection control standard because of contact with the oral mucosa. A preparation protocol is thus presented for increased inquiries about intraoral scanning requirements. Materials required for such a preparation include: a single-use bubble-free gel packet, a gel standoff pad, and a transducer probe cover. Postscan reprocessing of the ultrasound transducer requires high-level disinfection. Examples for proper and improper use are provided as well as limitations of this preparation protocol and recommendations for future development. This guidance meets the current infection control standard and may guide the user to obtain consistent ultrasound image quality.

Performance of Various Filtering Media for the Treatment of Cow Manure from Exercise Pens—A Laboratory Study

During summer and winter months, pastures and outdoor pens represent the conventional means of providing exercise for dairy cows housed in tie-stall barns in the province of Québec, Canada. Unfortunately, outdoor pens require large spaces, and their leachates do not meet Québec’s environmental regulations. Therefore, there is a need to develop alternative approaches for these so-called wintering pens. A sustainable year-long approach could be a stand-off pad consisting of a filtering media to manage adequately water exiting the pad. Different filtering materials can be used and mixed (gravel, woodchips, biochar, sphagnum peat moss, sand, etc.). To find the best material and/or mixes, a laboratory study was carried out using 15 PVC pipes (5 cm in diameter and 50 cm long) to test five different combinations of materials over a 3-week period. Different contaminant-removal efficiencies were achieved with the alternative materials, including for chemical oxygen demand (11–38%), phosphates (8–23%), suspended solids (33–57%), and turbidity (23–58%). Alternative treatments with sand, sphagnum peat moss, and biochar improved the filtration capacity when compared to the conventional material (woodchips). However, after three weeks of experimentation, the treatment efficiency of sand gradually decreased for pollutants such as suspended solids and phosphates.

Comparing a covered stand-off pad for on/off grazing during winter with conventional winter block grazing 2017-19 at DTT Stratford Demonstration farm

ABSTRACT
 A two-herd farmlet comparison was carried out on the DTT Stratford Demonstration Farm in Central Taranaki examined the profitability, environmental outcomes, animal welfare benefits and practicality of using a covered woodchip stand-off feed pad for wintering cows (Pad.) compared with wintering cows with no removal from pasture (Control). The two farmlets were set up and managed similarly in all aspects except that the non-lactating cows of one herd used the pad every night through the winter and over calving.
 Use of the covered pad limited winter pugging damage of pasture to minimal levels while the control farmlet had 6% of the area requiring rolling and some re-seeding. Pasture growth on these pugged areas was 24 to 30% lower than non-pugged areas over the spring to early summer period while estimated annual pasture growth was 2.2% higher on the Pad farmlet compared to the control over the two years. The mean difference in milksolids production across two years was 3%, (range :<1%- 5%) in favour of the Pad herd. Nutrient losses calculated using OverseerFM calculated a 9% reduction in nitrogen leached from the use of the covered pad.
 A cost benefit analysis suggests that at best the use of the covered stand-off in winter covered the annual operating cost of the stand-off pad but failed to contribute to the capital cost of providing this facility.
 Keywords –Pasture growth, pasture pugging, milksolids production, profit, Labour input, nitrogen leaching

The Potential for Temporary Stand-Off Pads Integrated With Poplar and Willow Silvopastoral Systems for Managing Nitrogen Leaching

Intensive pastoral farming has been linked to adverse environmental effects such as soil degradation and increased fluxes of nitrogen, phosphorus, sediments, and pathogens into waterways, resulting in their degradation. Stand-off pads are engineered structures covered with bedding materials, available for occupation by stock to minimise those adverse effects to soil and water bodies. Wood chips are ideal for bedding due to their low cost, high water holding capacity, and stock preference as resting areas. While they reduce the mobility of both nutrients and pathogens, their effectiveness depends on the type of wood, size of the chips, pH, pad design, and feeding management used. Dissolved organic carbon, present in wood residue, may slow nitrogen mineralisation thereby decreasing lossvialeachate. This effect depends on plant tannins and nutrients already stored within the plant tissue. Poplar and willow have high concentrations of tannins in leaves and bark with potential nitrification-inhibiting properties. When grown on-farm, these deep-rooted trees also reduce nitrogen leaching and prevent soil erosion. This review addresses the use of temporary stand-off pads within poplar or willow silvopastoral systems. Harvested trees can provide suitable wood chips for constructing the stand-off pad, while the deep rooting systems of the trees will reduce the moisture content of the pad, preventing waterlogging. A key objective is to discuss the feasibility and establishment of multiple temporary stand-off pads that allow for stock rotation from pad to pad, and subsequent on-site composting of wood-wastes into fertiliser, reducing both nutrient inputs and losses in agricultural systems. The review highlights the potential suitability of poplar and willow tree species for such a system.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

Intravenous Fluid Bag as a Substitute for Gel Standoff Pad in Musculoskeletal Point-of-care Ultrasound.

Point-of-care ultrasound (POCUS) is a tool undergoing expanding use in military medicine, including routine inpatient, outpatient, and operational environments. Specific musculoskeletal POCUS examinations require additional equipment in the form of a standoff assist device to maximize image acquisition. These devices may not be readily available to POCUS users in more austere or resource-constrained environments. We devised a study to determine if intravenous fluid bags of various volumes could be substituted for standard standoff devices in musculoskeletal POCUS. Sequential images of a soft tissue foreign body model, an interphalangeal joint, and a chest wall were taken using a gel standoff pad or water bath and compared to images acquired using three different sizes of intravenous fluid bags after removing excess air from the bags. Images were de-identified and scored for quality using a visual analog scale. We used a two-factor analysis of variance without replication to analyze the differences in image quality between standoff devices, with a P-value less than.05 considered statistically significant. We performed 13 POCUS studies and had a group of eight POCUS-trained physicians and physician assistants score these studies, resulting in 104 total quality scores. There was no significant difference in image quality between standoff devices for chest (P-value.280) and hand (P-value 0.947) images. We found a significant difference in image quality between standoff devices for the soft tissue foreign body model (P-value 0.039), favoring larger intravenous fluid bag standoff over standard devices. In the absence of a standard commercial gel standoff device or water bath, intravenous fluid bags of 50, 100, and 250 mL can facilitate quality image acquisition for musculoskeletal POCUS.

A Substitute of Ultrasound Acoustic Stand-Off Pad Made From Locally Available Material: An innovation to Survive in Resource Limited Conditions

Introduction: The use of stand-off acoustic pads for ultrasonographic evaluation of the superficial structures is well established. These are costly and not available readily at peripheral and remote community level institutes like ours. This instigated to make a simple and cheaper substitute to these stand-off pads. A cost effective alternative for these commercial acoustic stand-off pads made by using locally available condom and ultrasound jelly is presented here. Material and Methods: A latex condom, commonly available in hospital supplies, was filled with ultrasound coupling jelly. All the air was removed and a knot was secured at the end. The coupling jelly was applied between the skin condom and condom transducer interface while scanning. Superficial lesion of different body regions, breast and superficial foreign bodies were evaluated using the condom stand off pads. Observations: Scanning the area of interest using condom stand-off pad showed the overlying skin details, depth of lesion from the skin, internal architecture of the lesion and surrounding tissue in more detail than scanning without pad. The image quality of breast tissue or lesions located just below the nipple in sub retro-areolar region was better than these areas of interest scanning without pad. It also aided in evaluating the depth of superficial foreign body from the skin surface which helped in their surgical or image guided retrieval. Conclusion: The material used in making these condom stand-off pads is easily available and very cheap. The condom stand-off described here will help the radiologists working in remote or rural areas by providing them an easy to make and cheaper substitute in a resource limited setting. The quality of image and ease to handle is not as that of commercially available stand-off pads nevertheless condom stand-off pads serve the purpose well. Image quality improves quickly over time as operator gains dexterity in making and handling the condom contraptions.

Reliability and Feasibility of Extended Field of View Ultrasound Imaging Techniques for Measuring the Limb Muscle Cross-Sectional Area.

Purpose: Panoramic ultrasound imaging (pUSI) is an extended field of view (FOV) imaging technique that enables visualization of larger muscles; however, it is not available in all ultrasound systems. Using an acoustic standoff pad that is compatible with any ultrasound system may be an alternative method to increase FOV, but it has not been used to evaluate limb muscles. The purpose of this study was to evaluate the reliability and feasibility of using pUSI and an acoustic standoff pad to measure the limb muscle cross-sectional area (mCSA). Method: A cross-sectional study was conducted. Using pUSI and an acoustic standoff pad, we obtained B-mode ultrasound images of the rectus femoris, biceps brachii, and lateral gastrocnemius muscles of 26 healthy participants on two occasions 7-10 days apart. The agreement between the two methods was determined using intra-class correlation coefficients (ICCs) and Bland-Altman plots. Test-retest reliability was assessed using ICCs and standard error of measurement (SEM). The feasibility of acquiring and analyzing the images was evaluated using a Likert scale. Results: The acoustic standoff pad and pUSI demonstrated strong agreement (ICC[3,3]>0.85); however, the mCSAs were different (p<0.05). Test-retest reliability for each technique was high for all muscles (ICC[3,3]>0.85; SEM=0.6-1.5 cm2). Image acquisition was highly feasible, but there were some limitations in analyzing the images. Conclusions: pUSI and an acoustic standoff pad are two reliable techniques for measuring mCSA, but the measurements are not directly comparable. Future studies should evaluate the accuracy of the acoustic standoff pad compared with gold-standard methods.

Cow Lying Behaviour and Bedding Quality Changes during Five Weeks on a Stand-Off Pad.

Simple SummaryNew Zealand dairy farmers place cows in uncovered off-paddock facilities for a part (e.g., 18 h) of the day to reduce their impact on pasture during winter. Lying time is a key indicator of whether these hybrid pasture systems are meeting welfare requirements. While it is easy to measure lying time in a research setting using accelerometers, it is not yet common to measure it on farm, and more convenient indicators are needed. We investigated the lying behaviour of dairy cows as bedding quality deteriorated over a five-week period to determine what measures may be useful as farmer-friendly indicators of cow welfare. The daily lying time of the two groups of cows on bedding according to normal farm practice (NFP) declined over the five weeks and was significantly less than that of cows on fresh bedding during the last 10 days of the trial. The fresh woodchip bedding contained less than 65% moisture throughout the trial. By week 3 and week 4, the moisture content of the lying surface exceeded 75% for NFP Group 2 and Group1, respectively. A bedding moisture threshold of 75% assessed by a ‘gumboot score’ and cows lying rather than grazing when on pasture may be useful farmer-friendly indicators of cow welfare because of their relationship with reduced lying time.Bedding quality and cow lying time were measured during five weeks in a normal farm practice (NFP) off-paddock system with no bedding refreshment. Two groups of 100 non-lactating dairy cows were compared to groups of 8 cows with fresh bedding (FB). The cows were on a woodchip pad for 18 h/d at a space allowance of 5.4 m2/cow, with 6 h/d on pasture for 5 weeks. Lying times were recorded continuously for 60 cows per group using accelerometers. Bedding moisture content was measured weekly. Data for each NFP group were analysed and compared with those of their respective FB group using repeated measures. The lying time declined over five weeks from 11.6 h/day during the first week to 5.6 h/day during the fifth week (SED = 0.3; F1,25 = 351.56; p < 0.001). The moisture content of the bedding increased over the five weeks and was significantly higher for both NFP groups (NFP Group 1: F5,59 = 8.33; p < 0.001; NFP Group 2: F5,61 = 5.54; p < 0.001) than those of the respective FB groups. The percentage of total time lying when in the paddock increased for the NFP groups, reaching 15% in the last week of the trial. During five weeks on a stand-off pad, bedding quality deteriorated, and cows lay down less, to such an extent that welfare was compromised.

Utility of a gel stand-off pad in the detection of Doppler signal on focal nodular lesions of the skin.

Gel pad is an aqueous, flexible, easy available, disposable spacer used for the ultrasound (US) scan of superficial or difficult-to-visualize areas. In clinical practice, it is widely used in B-mode US approach of superficial lesions but, to date, no data have been provided as to its efficacy in the Doppler detection of superficial flows. The aim of our study was to demonstrate the role of stand-off gel pad in the detection of the otherwise-missed peri- or intra-lesional flow signals on Doppler imaging. A total of 100 superficial lesions undergone to an US evaluation using a 7.5-12-MHz linear probe were evaluated prospectively with and without interposition of a gel stand-off pad to detect the presence or absence of vascularization and to classify the vascular pattern. Peri- or intra-lesional flow was demonstrated in 56% of cases without and in 84% of cases with interposition of a gel stand-off pad; moreover, a statistically significant difference (p value < 0.001) was observed at Chi-square test in the identification of the flow pattern between the use and no use of the pad. The use of a gel stand-off pad allows the detection of otherwise-missed peri- or intra-lesional flow signals on Doppler imaging, increasing the diagnostic role of this technique in differential diagnosis of superficial lesions.

Production and profit of current and future dairy systems using differing nitrogen leaching mitigation methods: the Pastoral 21 experience in Waikato

ABSTRACT The aim of the study was to determine if existing technologies could reduce nitrate leaching by 50%; while maintaining high levels of milk production and profitability. One farmlet, typical of the Waikato (‘CURRENT’) was stocked at 3.2 cows/ha and compared with a farmlet stocked at 2.6 cows/ha (‘FUTURE’), focusing on higher cow production through the use of higher genetic merit cows, lower N fertiliser usage and removing cows from pasture (to a stand-off pad) during critical N leaching periods. The mitigation methods employed on the FUTURE farmlet reduced N leaching by 43% but meant the FUTURE farmlet was more expensive to run than the CURRENT (Control) farmlet. Although cows on the FUTURE farmlet each produced 68 kg more milksolids, production per hectare was 50 kg lower. Thus, the FUTURE farmlet yielded on average $279/ha/yr less profit than the CURRENT farmlet.

Comparing head impact kinematics simultaneously measured using 6 different sensors in a human cadaver model

ObjectiveTo compare head kinematics measurements obtained from 6 different head impact sensors utilizing different methods of sensor-to-head fixation.DesignFree-drop impacts (total n = 54) were performed at 3.5 and 5.5 m/s onto to the front, back, side, and top of 2 elderly human cadaveric head-neck specimens: a helmeted (Riddell Revolution Speed) male specimen was dropped onto a NOCSAE testing pad; an un-helmeted female specimen was dropped onto a framed sample of field turf. The specimens were instrumented with an intracranial reference sensor surgically mounted at the approximate head center-of-mass by a rigidly-fixed custom standoff pad, an intra-oral test sensor rigidly fixed to the upper teeth/hard palate by a custom orthodontic appliance, and 4 commercially available head impact sensing systems: X-Patch, Vector mouth guard, HITS (helmeted condition only), and G-Force Tracker (affixed to helmet interior or head band depending on helmet status). Peak linear and rotational head accelerations (PLA and PRA) were compared between each sensor and the intracranial reference sensor using intraclass correlation coefficients (ICC [2, 1]).ResultsAgreement with reference PLA and PRA values differed between sensors, with the greatest agreement observed for the rigidly affixed intraoral sensor (ICC = 0.921, PLA; ICC = 0.810, PRA). Agreement for PLA and PRA, respectively, was: for X-Patch, ICC = 0.638, ICC = 0.155; for Vector mouth guard, ICC = 0.775, ICC = 0.480; for HITS, ICC = 0.662 (PLA only); for G-Force Tracker, ICC = 0.364 (PLA only).DiscussionHead kinematics measurements during free-drop testing differed among sensors using different approaches of fixation to the head. There was greater agreement with intracranial reference PLA and PRA values for a rigidly affixed intraoral sensor utilizing an orthodontic appliance than for commercially available sensors incorporated into athletic equipment or otherwise non-rigidly affixed to the head. Measurement error attributable to non-rigid sensor-head coupling could potentially be reduced by incorporating an impact sensor into an orthodontic appliance in future research.

Mensuração ultrassonográfica dos ligamentos colaterais da articulação interfalangeana distal de equinos da raça Crioula

Criollo horses were used in the past only for field services, especially countryside work. However, currently, they have been used as sports animals in several modalities involving turns in legs and exercises on irregular terrain, predisposing them to injuries in the distal extremity. Among the alterations recognized as cause of lameness in this region are the conditions related to collateral ligaments of the distal interphalangeal joint (CL-DIPJ), which in horses are structures that help to maintain joint stability and suffer a high pressure due to the high body weight, especially when it is not equally distributed at the stance phase. Considering the importance of the ultrasound anatomical knowledge of this structure for the early diagnosis of locomotive affections in the digit of Criollo horses, this study aimed to standardize CL-DIPJ measurements in healthy horses of this breed. We used 25 adult Criollo horses not submitted to sports practice. For ultrasonographic evaluation, after a trichotomy of the region, an ultrasound Chison 8300VET and a 6.0 MHz linear probe were used with a standoff pad. This technique uses a cross-sectional view, in which CL-DIPJ is visualized in the distal concavity portion of the middle phalanx, being a standard for the measurements. For ligament measurements, the variables dorsopalmar diameter (DPD), latero-medial diameter (LMD), and cross-sectional area (CSA) of ligaments were used. Three measurements were performed for each variable and average values were obtained, which were compared to each other and did not present significant differences (p &gt; 0.05). The average measurements of diameter and area of collateral ligaments of the distal interphalangeal joint in Criollo horses were 9.04 mm for DPD, 7.55 mm for LMD, and 0.52 mm2 for CSA. This was the first study that standardized the size of this structure in this breed.

Effects of surface type in an uncovered stand-off pad system on comfort and welfare of non-lactating dairy cows during winter

The objective of this study was to investigate the effect of stand-off surface type on cow lying behaviour, cleanliness and lameness. One hundred and sixty Friesian × Jersey crossbreed, pregnant non-lactating dairy cows were blocked into five groups of 32 cows and randomly assigned to one of five treatments. Treatments consisted of cows grazing fodder beet in situ and remaining in the paddock with no stand-off (control), or grazing fodder beet in situ and spending 16 h on a stand-off pad with either a woodchip, round-stones (40–60 mm), sand, or geotextile ‘carpet’ surface. Lying duration, monitored by AfiAct electronic pedometers (Afimilk, Kibbutz Afikim, Israel), showed cows on stone spent significantly more (P < 0.001) time lying (9.5 h) than cows on woodchip (8.4 h), control (8.1 h), and sand (7.6 h), but similar to those on carpet (8.8 h). However, there were fewer (P < 0.001) lying bouts (4.6 bouts/d) and longer (P < 0.001) bout duration (137 min/bout) for cows on stone than other treatments (average 7 bouts/day and 85 min/bout), which may suggest that cows found standing and sitting on the stone surface uncomfortable. As measured by a cleanliness score, cows on the sand surface were less (P < 0.001) clean than cows on other surfaces. Lameness, which was determined by visual scoring, revealed only moderate cases of lameness which tended (P = 0.059) to be more prevalent for cows on stone (11.3%) or sand (12.5%), compared with lowest in woodchip (4.0%) or carpet (4.7%), and intermediate in the control treatment (8.8%). The data indicate that sand and the size of stone used are less suitable surfaces than woodchip or carpet for an uncovered winter stand-off pad to meet minimum requirements of animal comfort and welfare. While both the woodchip and carpet surfaces equally met animal welfare standards, the woodchip required less maintenance.

The effect of pleural fluid layers on lung surface wave speed measurement: Experimental and numerical studies on a sponge lung phantom

Pleural effusion manifests as compression of pleural fluid on the lung parenchyma contributing to hypoxemia. Medical procedures such as drainage of plural fluid releases this compression and increases oxygenation. However, the effect of pleural effusion on the elasticity of lung parenchyma is unknown. By using lung ultrasound surface wave elastography (LUSWE) and finite element method (FEM), the effect of pleural effusion on the elasticity of superficial lung parenchyma in terms of surface wave speed measurement was evaluated in a sponge phantom study. Different thicknesses of ultrasound transmission gel used to simulated pleural fluid were inserted into a condom, which was placed between the sponge and standoff pad. A mechanical shaker was used to generate vibration on the sponge phantom at different frequencies ranging from 100 to 300 Hz while the ultrasound transducer was used to capture the motion for measurement of surface wave speed of the sponge. FEM was conducted based on the experimental setup and numerically assessed the influence of pleural effusion on the surface wave speed of the sponge. We found from FEM experiments that the influence of thickness of ultrasound transmission gel was statistically insignificant on the surface wave speed of the sponge at 100 and 150 Hz.

Ultrasound Evaluation of Soft-Tissue Foreign Bodies by US Army Medics.

Objective:The study's primary objective was to determine army medics' accuracy performing bedside ultrasound (US) to detect radiolucent foreign bodies (FBs) in a soft-tissue hand model. Secondary objectives included the assessment of US stand-off pad effects on soft-tissue FB detection rates and assess established FB detectable lower limit size of 2 mm.Methods:Prospective, single blinded, observational study of US-naïve Army medics' abilities utilizing bedside US to detect wooden FBs in a chicken thigh model with or without an US stand-off pad. After a 2 h training period, medics' abilities to detect 1–3 mm FB utilizing a SonoSite® M-Turbo US and 13–6 MHz linear probe were assessed.Results:After a 2 h training period, 28 medics had a sensitivity and specificity of 73% and 78% detecting 1–3 mm FBs utilizing standard US equipment. The medics' sensitivity and specificity were both 78% in detecting radiolucent FBs 2 mm and larger without a stand-off pad. The sensitivity and specificity decreased to 48%, 62%, and 67% when utilizing a stand-off pad to detect 1, 2, and 3 mm soft-tissue FBs. Sub 2 mm detection rates decreased from 82% for 2 mm FB to 64% for 1 mm FBs without utilizing a stand-off pad.Conclusion:Army medics with minimal US experience successfully identified FBs embedded in hand models with accuracies similar to radiologists and emergency medicine physicians. However, radiolucent FB detection sensitivity and specificity decreased in US-naïve Army medics utilizing stand-off pads. In addition, this study reconfirmed the lower limit of FB detection rates at 2 mm. These results support Army medics' utilization of US to evaluate for superficial radiolucent FBs of the hand.

Artifacts in Diagnostic Medical Ultrasound, Volume 1, Greyscale Artifacts (paperback)MartinNecas RRP: AU$79.00 ISBN‐13: 978‐0987292162 Publisher: High Frequency Publishing190 pages

This book is a comprehensive review of the full range of artifacts encountered in the usual practice of diagnostic ultrasound. It includes an account of acoustic artifacts (relating to the interaction of the ultrasound pulses with body tissues), as well as the misleading appearances that sometimes occur because of control settings applied by the operator (TGC, multiple focal zones, dynamic range, frame rate, spatial compounding, harmonics and others). One of its many strengths is that it describes the causes of the artifacts/appearances and includes mention of ways to avoid or eliminate those that are unhelpful or undesirable. The book is divided into thirteen chapters, with more than 230 images and explanatory diagrams, including colour images. Examples of everyday life optical equivalents of the phenomena causing the ultrasound appearances are shown and allow a better understanding of the mechanisms at play. The ultrasound images have reproduced well, with relevant features easily seen, often indicated by arrows or superimposed lines. The explanations of the origin of various artifacts are concise, without excessive technical detail. Examples are presented from a wide range of ultrasound applications, including abdominal, obstetric, vascular and musculoskeletal specialties. Examples of the same artifact, as it appears in images from different applications, are given. For this reason, the book is useful for anyone using diagnostic ultrasound equipment. Scanning tips, such as the need for orthogonal views to explain some appearances, are given throughout the book. Basic principles of transducers and beam formation are mentioned in the context of their effect on image quality, leading to an understanding of why and when to use a stand-off pad, or which transducer to select for a given application. Mention is made of the need for constant critical analysis of images to differentiate between echoes representing artifact and those representing pathology. A good example from abdominal sonography is the non-recognition of lung pathology because the echoes are mistaken as mirror images of liver or spleen, the most common cause of echoes above the diaphragm. A minor criticism can be made about the description of the phenomenon of anisotropy, described in the chapter on attenuation effects and also under refraction effects. The variation in brightness of echoes in a structure such as a tendon is ascribed to refraction effects, but is mainly due to the reduced return of echo signal to the transducer as the angle of approach to the fibrils varies from ninety degrees. Nevertheless, the need for caution and careful technique when scanning anisotropic structures is clearly conveyed. This book is a very useful and practical read for all who are using diagnostic equipment, regardless of background or the specialty of application. Anyone who reads and applies the advice in this publication should have a much better understanding of diagnostic ultrasound artifacts and is unlikely to make errors in diagnosis because of their misleading appearances. It should be in every department's library and read on a regular basis.