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

RATIONALE AND OBJECTIVES: To design and validate a peer-teacher based musculoskeletal ultrasound curriculum for radiology residents. MATERIALS AND METHODS: A 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. RESULTS: Thirty 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). CONCLUSION: Hands-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.

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

BACKGROUND: The 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. METHODS: This 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 30 min 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. RESULTS: Sixty patellar tendons in 30 subjects were evaluated (18 males, 12 females, mean age 22.5 years). 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 (P = 0.01) and decreased with age (P = 0.04). In sedentary individuals there was no significant correlation between age and tendon softness (P = 0.404). Similarly, gender showed no correlation with tendon softness (P > 0.05). CONCLUSIONS: Patellar 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. LEVEL OF EVIDENCE: Level 3.

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

OBJECTIVE: To determine current trends in postgraduate musculoskeletal ultrasound education across various medical specialties in the United States. MATERIALS AND METHODS: A 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. RESULTS: Response rates were 23, 25, 28 and 33% for physical medicine and rehabilitation, radiology, rheumatology and sports medicine programs, respectively. Among respondents, musculoskeletal ultrasound training was present in 65% of radiology programs, 88% of sports medicine programs, 90% of rheumatology programs, and 100% 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 5 years, 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 10 years ago. Case volume was lowest for radiology trainees and highest for sports medicine trainees. CONCLUSION: Among 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.

Acute left circumflex coronary artery occlusion detected on nongated CT.

We describe a patient with chest pain and a nondiagnostic electrocardiogram in whom computed tomographic (CT) aortography demonstrated myocardial hypoperfusion in the distribution of the circumflex artery as well as an abrupt cutoff of contrast in the left circumflex artery. Subsequent cardiac catheterization confirmed occlusion of the circumflex artery and led to revascularization. The diagnosis of acute myocardial infarction on CT can dramatically alter the clinical management of a patient, especially in cases in which other tests are equivocal.

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

BACKGROUND: Juvenile 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. OBJECTIVE: To 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 METHODS: Children 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. RESULTS: Twenty-one studies were conducted in 18 pediatric patients (15 female, 3 male; age range 3-19 years). Active myositis was present on MRI in ten cases. There was a significant association between abnormal MRI and clinically active disease (P = 0.012). 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 (P > 0.999) or clinically active disease (P > 0.999). 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 (P < 0.001). 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%. CONCLUSION: Compression-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 patient's 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.

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 9 second year 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 (DXIT(TM)) 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 (p = 0.008) and receiving attending feedback (p = 0.004) than group 2. A non-significant trend towards reduced anxiety prior to NC was present in group 1 (p = 0.077). No difference in independence (p = 0.918), autonomy (p = 0.635), or confidence during (p = 0.431) or after NC (p = 1.00) was identified. DXIT(TM) scores were not significantly different between the two groups (p = 0.396). 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 DXIT(TM) scores. Plain radiograph interpretation may need to be further emphasized.

Ultrasound elastography in children: establishing the normal range of muscle elasticity.

BACKGROUND: Ultrasound elastography allows assessment of tissue elasticity. To the best of our knowledge, the elastography appearance of muscles in normal children has not been described. OBJECTIVE: To determine the US elasticity of muscles in children at rest and following exercise. MATERIALS AND METHODS: Cine elastography of biceps brachii and rectus femoris muscles was obtained at rest and after exercise in 42 healthy children (23 males, 19 females; mean: 11.2 ± 4.4 years, range: 2-18 years). 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. RESULTS: Resting muscle elasticity was lower in the biceps brachii than in the rectus femoris (P = 0.008), and higher in the dominant than in the nondominant biceps brachii (P < 0.032). Rectus femoris elasticity was higher in males than females (P = 0.051). Postexercise muscle elasticity significantly increased in both the dominant and nondominant biceps brachii (P < 0.001) and in the rectus femoris (P < 0.001). 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. CONCLUSION: Resting 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.

A new, simple method for estimating pleural effusion size on CT scans.

BACKGROUND: There is no standardized system to grade pleural effusion size on CT scans. A validated, systematic grading system would improve communication of findings and may help determine the need for imaging guidance for thoracentesis. METHODS: CT scans of 34 patients demonstrating a wide range of pleural effusion sizes were measured with a volume segmentation tool and reviewed for qualitative and simple quantitative features related to size. A classification rule was developed using the features that best predicted size and distinguished among small, moderate, and large effusions. Inter-reader agreement for effusion size was assessed on the CT scans for three groups of physicians (radiology residents, pulmonologists, and cardiothoracic radiologists) before and after implementation of the classification rule. RESULTS: The CT imaging features found to best classify effusions as small, moderate, or large were anteroposterior (AP) quartile and maximum AP depth measured at the midclavicular line. According to the decision rule, first AP-quartile effusions are small, second AP-quartile effusions are moderate, and third or fourth AP-quartile effusions are large. In borderline cases, AP depth is measured with 3-cm and 10-cm thresholds for the upper limit of small and moderate, respectively. Use of the rule improved interobserver agreement from κ = 0.56 to 0.79 for all physicians, 0.59 to 0.73 for radiology residents, 0.54 to 0.76 for pulmonologists, and 0.74 to 0.85 for cardiothoracic radiologists. CONCLUSIONS: A simple, two-step decision rule for sizing pleural effusions on CT scans improves interobserver agreement from moderate to substantial levels.

Normal myocardial perfusion on 64-detector resting cardiac CT.

BACKGROUND: Computed tomography (CT) of the heart is increasingly used to characterize not only the coronary arteries but also cardiac structure and function. The performance of CT in depicting myocardial perfusion is under active investigation. OBJECTIVE: We describe the pattern of normal myocardial perfusion on resting 64-detector cardiac CT. METHODS: Patients (n = 33; 20 women, 13 men; mean age, 52 years) with normal radionuclide myocardial perfusion imaging and normal coronary arteries on CT angiography (120 kVp) comprised the study population. Segmental myocardial perfusion on CT was measured in Hounsfield units (HU) with manual and semiautomated methods for the 17-segment American Heart Association model in both systole and diastole. Segments were aggregated into coronary artery territories, from apex to base and by myocardial wall. The relationships between myocardial perfusion and various patient factors were evaluated. RESULTS: Overall mean myocardial perfusion was 98 HU in systole and 94 HU in diastole with the manual method (P = .011) and 92 HU in systole and 95 HU in diastole with the automated method (P = .001). The septum showed significantly higher mean attenuation values than the other walls in systole and diastole with both methods. Generally, attenuation values were lower in the left circumflex artery territory and in the apex. Bivariate analysis showed higher mean myocardial attenuation values for women than men, although this difference did not persist on multivariate analysis adjusted for patient size. CONCLUSION: Normal mean resting myocardial perfusion correlates with CT attenuation values of approximately 92-98 HU on CT angiography in the coronary arterial phase. The septum consistently shows greater attenuation values than the other walls.

A man with a horseshoe adrenal gland associated with a midline posterior diaphragmatic defect.

We present a case of a horseshoe adrenal gland and a posterior midline diaphragmatic defect found incidentally on computed tomography in a 60-year-old man. It is, to our knowledge, the first case in an adult and represents a relatively innocuous developmental abnormality when compared with the previously described fetal and infantile adrenal fusion syndrome. This case demonstrates the importance of cross-sectional imaging and the effectiveness of computed tomography in defining the spectrum of congenital anomalies.

Variants and anomalies of thoracic vasculature on computed tomographic angiography in adults.

OBJECTIVE: To determine the prevalence and clinical significance of normal, variant, and anomalous branching patterns of the aortic arch and the central veins on computed tomographic (CT) angiography in adults. METHODS: We retrospectively reviewed 1000 consecutive CT angiograms of the chest in 658 women and 342 men with a median age of 53 years. RESULTS: A total of 65.9% of patients had both normal aortic arch branching patterns and normal venous anatomy. Variants in the aortic arch branching pattern were present in 32.4% and anomalies in 1.5%. Venous anomalies were present in 0.7%. Review of CT reports showed that cardiothoracic radiologists correctly reported the anomaly more frequently than other radiologists (94% vs 20%, P = 0.003). CONCLUSIONS: Whereas anomalies of the central thoracic vasculature are uncommon, variants in the aortic arch branching pattern are common. An appreciation of the appearance of these entities on CT angiography allows for precise reporting and is useful in preprocedure planning.

Kounis syndrome secondary to ibuprofen use.

Kounis syndrome is the coincidental occurrence of acute coronary syndromes with allergic or hypersensitivity reactions. Clinicians should be aware that various mediators of allergy can cause coronary spasm and even plaque rupture and thrombus formation, thereby causing a serious impact on the course, prognosis and management of the allergic reaction. We report a case of a 20 year old female who developed acute coronary syndrome after anaphylactic reaction to ibuprofen.