Netanel S. Berko

Ultrasound elastography in children: Establishing the normal range of muscle elasticity

BackgroundUltrasound elastography allows assessment of tissue elasticity. To the best of our knowledge, the elastography appearance of muscles in normal children has not been described.ObjectiveTo determine the US elasticity of muscles in children at rest and following exercise.Materials and methodsCine elastography of biceps brachii and rectus femoris muscles was obtained at rest and after exercise in 42 healthy children (23 males, 19 females; mean: 11.2u2009±u20094.4xa0years, range: 2–18xa0years). Elastography scores were assigned to each clip based on a five-point color scale. Mean elastography scores and standard deviations were calculated and resting and postexercise elastography scores were compared.ResultsResting muscle elasticity was lower in the biceps brachii than in the rectus femoris (Pu2009=u20090.008), and higher in the dominant than in the nondominant biceps brachii (Pu2009<u20090.032). Rectus femoris elasticity was higher in males than females (Pu2009=u20090.051). Postexercise muscle elasticity significantly increased in both the dominant and nondominant biceps brachii (Pu2009<u20090.001) and in the rectus femoris (Pu2009<u20090.001). There was no significant gender-related difference in postexercise muscle elasticity. Biceps brachii elasticity decreased and rectus femoris elasticity increased with increasing body mass index. Younger subjects had a greater change in muscle elasticity with exercise.ConclusionResting muscle elasticity in children is significantly lower in the biceps brachii than in the rectus femoris and in the nondominant biceps brachii than in the dominant biceps brachii. Elasticity significantly increases immediately postexercise in both muscle groups; resting differences between biceps brachii and rectus femoris elasticity, and dominant and nondominant biceps brachii elasticity, do not persist after exercise. The change in muscle elasticity with exercise is higher in younger children.

The impact of on-site attending radiologist overnight coverage on radiology resident learning: a preliminary assessment

The objective of this study is to assess the impact of on-site attending radiologist overnight coverage on resident education during transition to 24/7 attending coverage. The study was exempted from IRB review. An anonymous survey was sent to 9xa0secondxa0year radiology residents who completed their first night call rotation (NC) with an attending radiologist (group 1) and 18 residents who completed their first NC prior to overnight attending coverage (group 2). This addressed anxiety level prior to NC, work pace, autonomy and confidence, and attending feedback, with responses graded on a five-point scale. Statistical analysis was performed using Spearman’s rho correlation coefficient. Diagnostic Radiology In-Training (DXITTM) exam scores were collected prior to and following completion of the NC rotation, and results were compared. Case volume before and after the transition was recorded. p value <0.05 indicated statistical significance. Eight out of nine residents in group 1 and 16 out of/18 residents in group 2 completed the survey. Group 1 was more likely to report working at a comfortable pace (pu2009=u20090.008) and receiving attending feedback (pu2009=u20090.004) than group 2. A non-significant trend towards reduced anxiety prior to NC was present in group 1 (pu2009=u20090.077). No difference in independence (pu2009=u20090.918), autonomy (pu2009=u20090.635), or confidence during (pu2009=u20090.431) or after NC (pu2009=u20091.00) was identified. DXITTM scores were not significantly different between the two groups (pu2009=u20090.396). While overall case volume dictated by residents increased, fewer plain radiographs were dictated. Overnight attending coverage provides a more comfortable pace of study interpretation and increased attending feedback without decreasing resident independence or DXITTM scores. Plain radiograph interpretation may need to be further emphasized.

Effect of knee position on the ultrasound elastography appearance of the patellar tendon

Structural alterations in tendons and muscles secondary to acute or chronic injury may alter tissue compressibility. Such alteration may be detected using strain ultrasound elastography, which employs manual compression to assess the compressibility of a superficial structure by generating a colour-coded elastogram superimposed on a conventional grey-scale ultrasound image.1 Numerous reports have demonstrated the benefit of ultrasound elastography in evaluating the Achilles tendon, where it has been shown to detect abnormalities earlier than standard grey-scale ultrasound.2e5 Additionally, ultrasound elastography has been proven useful in the elbow when assessing the common extensor tendon in patients with lateral epicondylitis.6 The superficial location of the patellar tendon makes it ideal for evaluation with ultrasound. Sonographic detection of patellar tendinopathy, tear, bursitis, and peritendinous abnormalities have been described7; however, to date, ultrasound elastography of the patellar tendon has not been widely used, and no standardised technique with respect to

Survey of current trends in postgraduate musculoskeletal ultrasound education in the United States

ObjectiveTo determine current trends in postgraduate musculoskeletal ultrasound education across various medical specialties in the United States.Materials and methodsA survey regarding musculoskeletal ultrasound education was sent to all program directors for diagnostic radiology and physical medicine rehabilitation residency programs, as well as adult rheumatology and sports medicine fellowship programs in the United States. The survey, sent in July 2015, queried the presence of formal musculoskeletal ultrasound training, the components of such training and case volume for trainees.ResultsResponse rates were 23, 25, 28 and 33xa0% for physical medicine and rehabilitation, radiology, rheumatology and sports medicine programs, respectively. Among respondents, musculoskeletal ultrasound training was present in 65xa0% of radiology programs, 88xa0% of sports medicine programs, 90xa0% of rheumatology programs, and 100xa0% of physical medicine and rehabilitation programs. Most programs utilized didactic lectures, followed by hands-on scanning. The majority of programs without current training intend to implement such training within 5xa0years, although radiology programs reported the lowest likelihood of this happening. Most program directors believed that musculoskeletal ultrasound education is important for their trainees, and is of greater importance than it was 10xa0years ago. Case volume was lowest for radiology trainees and highest for sports medicine trainees.ConclusionAmong respondents, the majority of diagnostic radiology programs offer musculoskeletal ultrasound training. However, this experience is even more widespread in other medical specialties, and hands-on training and experience tend to be greater in other specialties than in radiology.

Efficacy of ultrasound elastography in detecting active myositis in children: can it replace MRI?

BackgroundJuvenile idiopathic inflammatory myopathy is a rare yet potentially debilitating condition. MRI is used both for diagnosis and to assess response to treatment. No study has evaluated the performance of US elastography in the diagnosis of this condition in children.ObjectiveTo assess the performance of compression–strain US elastography in detecting active myositis in children with clinically confirmed juvenile idiopathic inflammatory myopathy and to compare its efficacy to MRI.Materials and methodsChildren with juvenile idiopathic inflammatory myopathy underwent non-contrast MR imaging as well as compression–strain US elastography of the quadriceps muscles. Imaging findings from both modalities were compared to each other as well as to the clinical determination of active disease based on physical examination and laboratory data. Active myositis on MR was defined as increased muscle signal on T2-weighted images. Elastography images were defined as normal or abnormal based on a previously published numerical scale of muscle elastography in normal children. Muscle echogenicity was graded as normal or abnormal based on gray-scale sonographic images.ResultsTwenty-one studies were conducted in 18 pediatric patients (15 female, 3 male; age range 3–19xa0years). Active myositis was present on MRI in ten cases. There was a significant association between abnormal MRI and clinically active disease (Pu2009=u20090.012). US elastography was abnormal in 4 of 10 cases with abnormal MRI and in 4 of 11 cases with normal MRI. There was no association between abnormal elastography and either MRI (Pu2009>u20090.999) or clinically active disease (Pu2009>u20090.999). Muscle echogenicity was normal in 11 patients; all 11 had normal elastography. Of the ten patients with increased muscle echogenicity, eight had abnormal elastography. There was a significant association between muscle echogenicity and US elastography (Pu2009<u20090.001). The positive and negative predictive values for elastography in the determination of active myositis were 75% and 31%, respectively, with a sensitivity of 40% and specificity of 67%.ConclusionCompression–strain US elastography does not accurately detect active myositis in children with juvenile idiopathic inflammatory myopathy and cannot replace MRI as the imaging standard for detecting myositis in these children. The association between abnormal US elastography and increased muscle echogenicity suggests that elastography is capable of detecting muscle derangement in patients with myositis; however further studies are required to determine the clinical significance of these findings.

Computed tomographic imaging of renal and ureteral emergencies.

A variety of renal and ureteral pathologies are encountered on computed tomographic scans performed in the emergency department. Although these are often suspected based on the patients clinical presentation, they may also be fortuitous or incidental findings. Stone disease is the most common genitourinary condition seen in the acute setting; however, other conditions such as infection, hemorrhage, acute ischemic disease, and iatrogenic and traumatic injuries may also occur. We review the computed tomographic features of the spectrum of these conditions.

Imaging Appearances of Musculoskeletal Developmental Variants in the Pediatric Population

Variations in musculoskeletal development in children are commonly encountered. These variants often have a confusing appearance on imaging and may simulate pathologic conditions. However, in many instances, these normal variants have certain features that allow for confident determination of the benign nature of these entities. An awareness of the characteristic imaging features is therefore important for radiologists. In this review, we focus on 4 specific categories of variants in the development: (1) variations in the normal ossification of skeletal structures, (2) the appearance of tendinous and ligamentous insertions in the developing skeleton, (3) overlapping lines that can be confused with fractures or other pathologic conditions, and (4) variant orientation of normal bones. We review the etiology and imaging appearance of these entities and also describe methods of differentiating these benign entities from pathologic lesions. Although in certain cases, correlation with clinical parameters is needed to confidently diagnose the lesion as benign, in many cases, an appreciation of the characteristic imaging features alone would suffice and prevent a potentially costly workup.

Incorporation of musculoskeletal ultrasound training into the radiology core curriculum

The use of ultrasound for the assessment of musculoskeletal pathological conditions has increased significantly in recent years in the USA [1, 2]. Targeted examination, absence of radiation, widespread availability, lower cost than MRI, and ability to perform interventions at the time of diagnostic evaluation make ultrasound an ideal modality for the evaluation of a wide variety of musculoskeletal conditions [3]. As interest in musculoskeletal ultrasound in the USA continues to grow, it is important for radiology residents to receive adequate training in this modality. A recent survey of program directors from various specialties showed that radiology residents received less musculoskeletal ultrasound training than trainees from physical medicine and rehabilitation, sports medicine and rheumatology programs [4]. Furthermore, radiology residency programs that lacked musculoskeletal ultrasound training were less likely to implement such training in the near future than programs from other specialties [4]. Among the challenges facing radiology programs in the USA in the implementation of musculoskeletal ultrasound training is a lack of available faculty members to provide such training [4]. In some programs, this is because of the lack of faculty members trained in musculoskeletal ultrasound, whereas in others, this could be due to busy clinical services with a lack of time available to devote to such training. Widespread incorporation of musculoskeletal ultrasound training into the radiology core curriculum requires approaches that address these challenges. The use of electronic, web-based modules is one approach that has successfully been utilized for musculoskeletal ultrasound training. Maloney et al. designed an electronic learning module for radiology resident musculoskeletal ultrasound training [5]. The module addressed topics including image optimization, musculoskeletal ultrasound anatomy, artifacts, and pathology. A variety of interactive features, including videos, animations, and multiple-choice questions, were used in the module. They found that this module had similar educational efficacy to a traditional, didactic lecture. Benefits of electronic modules include the ability to easily distribute the content widely on the internet, and these modules can therefore be used by residents in programs that lack radiologists familiar with musculoskeletal ultrasound. Additionally, the interactive, self-directed learning structure of electronic modules may be the preferred learning approach for residents, as reflected by slightly higher satisfaction ratings with the electronic module than the didactic lecture in the study by Maloney et al. [5]. Although electronic, web-based modules can be used to teach ultrasound image interpretation, the ability of a resident to appropriately scan a patient and obtain diagnostic images requires hand-on training. Hands-on training relies more on the physical presence of a radiologist with musculoskeletal ultrasound experience than does didactic teaching. A technique that can be used to minimize the number of radiologists required for such training is the use of peer teachers. Peer teaching is defined as students teaching other students [6]. Peer teachers have been utilized successfully in a variety of medical student and postgraduate training settings [7–11]. Knobe et al. compared the efficacy of shoulder ultrasound training for thirdand fourth-year medical students taught by * Netanel S. Berko Netanel.Berko@uphs.upenn.edu

Ultrasound elastography of the patellar tendon in young, asymptomatic sedentary and moderately active individuals

BACKGROUNDnThe recent use of ultrasound elastography to study patellar tendon softness has demonstrated increased tendon softness in high-level athletes. We hypothesized that measurable alterations in patellar tendon softness may be present in young asymptomatic subjects engaging in moderate levels of physical activity.nnnMETHODSnThis was a cross-sectional study. Gray-scale ultrasound and ultrasound elastography of the right and left patellar tendons were performed in young asymptomatic sedentary subjects and moderately active subjects who engaged in at least 30u202fmin of physical activity 4-5 times weekly. The distribution of soft, intermediate and stiff tissue within each tendon was analyzed. Tendon softness was correlated with subject age, gender and level of athletic activity.nnnRESULTSnSixty patellar tendons in 30 subjects were evaluated (18 males, 12 females, mean age 22.5u202fyears). Seventeen subjects were defined as active and 13 as sedentary. All tendons had a normal gray-scale sonographic appearance. Tendon softness was significantly higher in active subjects (Pu202f=u202f0.01) and decreased with age (Pu202f=u202f0.04). In sedentary individuals there was no significant correlation between age and tendon softness (Pu202f=u202f0.404). Similarly, gender showed no correlation with tendon softness (Pu202f>u202f0.05).nnnCONCLUSIONSnPatellar tendon softness is higher in young subjects and in those engaging in moderate physical activity. This may reflect an adaptation to increased tendon load. Tendon softness in active subjects decreases with age, while it remains at a constant value in sedentary individuals.nnnLEVEL OF EVIDENCEnLevel 3.

Design and Validation of a Peer-Teacher-Based Musculoskeletal Ultrasound Curriculum

RATIONALE AND OBJECTIVESnTo design and validate a peer-teacher based musculoskeletal ultrasound curriculum for radiology residents.nnnMATERIALS AND METHODSnA musculoskeletal ultrasound curriculum with hands-on scanning workshops was designed for radiology residents. Prior to the workshops, several residents received 3 hours of hands-on training in ultrasound scanning technique which was overseen by an attending musculoskeletal radiologist; these peer teachers then led small-group hands-on scanning during the workshops. Participants performed diagnostic ultrasound examinations at the conclusion of the workshops to assess skill acquisition and 2 months following the workshops to quantify skill retention. Participants also completed surveys to determine confidence in performing musculoskeletal ultrasound examinations. Median scores and interquartile range (25-75%) were calculated, and t test was used to compare results.nnnRESULTSnThirty seven residents from all years of training and six senior resident or fellow peer teachers participated in four workshops. Diagnostic ultrasound images were obtained in 100% at the conclusion of the workshop and in 79% 2 months later. Prior to the workshops, residents reported low level of musculoskeletal ultrasound knowledge (median 2, interquartile ranges 1-2), and low confidence in performing (1, 1-2) and interpreting (1, 1-2) musculoskeletal ultrasound examinations. There was a significant increase in knowledge (3, 3-4) and confidence performing (3, 3-4) and interpreting (3, 3-4) studies following the workshops (p < 0.001 for all comparisons).nnnCONCLUSIONnHands-on musculoskeletal ultrasound workshops, utilizing a peer teacher led small group format is an effective method of teaching scanning skills to residents. There was excellent skill acquisition, good skill retention, and significant increase in confidence performing and interpreting these studies following completion of the curriculum.