Effect of Carpal Tunnel Syndrome on the Ulnar Nerve at the Wrist
Sonographic and Electrophysiologic Studies
The aim of this study was to compare the ulnar nerve at the wrist by sonographicand electrophysiologic studies between patients with carpal tunnel syndrome and control participants and to verify the effect of carpal tunnel syndrome of the ulnar nerve at the wrist.
Forty-two hands of patients with carpal tunnel syndrome and 37 hands of control participants were examined. Electrophysiologic studies of the ulnar nerve were done in all participants. The cross-sectional areas of the median and ulnar nerves at the wrist were evaluated by sonography. Fifteen hands of patients with carpal tunnel syndrome who underwent carpal tunnel release were also evaluated by sonography after the operation.
The ulnar nerve cross-sectional area of the patients with carpal tunnel syndrome (mean ± SD, 5.16 ± 1.04 mm) was significantly larger than that of the controls (3.56 ± 0.52 mm; < .0001). After release of the transverse carpal ligament, the cross-sectional area of the ulnar nerve was significantly smaller than the size measured prior to surgery ( < .0001). The cross-sectional area of the median nerve was significantly correlated with that of the ulnar nerve ( < .05). However, no statistically significant difference was found between the patients with carpal tunnel syndrome and controls in ulnar nerve conduction. There were no statistically significant differences in nerve conduction study results or cross-sectional area of the ulnar nerve between patients with carpal tunnel syndrome with and without extramedian symptoms.
The cross-sectional areas of the ulnar and median nerves at the wrist are increased in patients with carpal tunnel syndrome. Also, the cross-sectional area of the ulnar nerve is decreased after carpal tunnel release.
o February 25, 2015.
o March 31, 2015.
o April 13, 2015.
o © 2016 by the American Institute of Ultrasound in Medicine
Role of Sonography in Clinically Occult Femoral Hernias
The purpose of this article is to evaluate the diagnostic accuracy of sonography in clinically occult femoral hernias and to describe our sonographic technique.
The clinical and imaging data for 93 outpatients referred by general surgeons, all of whom underwent sonographic evaluation and surgery, were reviewed retrospectively. Of these, 55 patients who underwent surgical exploration for groin hernias within 3 months of sonography and met all inclusion criteria were included in the study. The sonographic technique involves using the pubic tubercle as an osseous landmark to identify and appropriately visualize the femoral canal. The Valsalva maneuver is then used to differentiate the movement of normal fat (a potential pitfall) from true herniation in the femoral canal. Surgical findings were used as the reference standard by which sonographic results were judged. Two-by-two contingency tables were used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value.
In these 55 patients, surgery revealed 15 femoral hernias. Eight femoral hernias occurred in women, and 7 occurred in men. For diagnosing femoral hernias, sonography demonstrated sensitivity of 80%, specificity of 88%, a positive predictive value of 71%, and a negative predictive value of 92%. True-positive cases of femoral hernias have a sonographic appearance of a hypoechoic sac with speckled internal echoes. When examining during the Valsalva maneuver, a femoral hernia passes deep to the inguinal ligament, expands the femoral canal, displacing the normal canal fat, and effaces the femoral vein.
Sonography can exclude femoral hernias with high confidence in light of its exceptional negative predictive value. With attention to technique and imaging criteria, the diagnostic accuracy of sonography can be enhanced.
o February 25, 2015.
o April 6, 2015.
o May 6, 2015.
Defining Competencies for Ultrasound-Guided Bedside Procedures
Consensus Opinions From Canadian Physicians
This study sought to define the competencies in ultrasound knowledge and skills that are essential for medical trainees to master to perform ultrasound-guided central venous catheterization, thoracentesis, and paracentesis.
Experts in the 3 procedures were identified by a snowball technique through 3 Canadian tertiary academic health centers. Experts completed 2 rounds of surveys, including an 88-item central venous catheterization survey, a 96-item thoracentesis survey, and an 89-item paracentesis survey. For each item, experts were asked to determine whether the knowledge/skill described was essential, important, or marginal. Consensus on an item was defined as agreement by at least 80% of the experts. For items on which consensus was not reached during the first round of surveys, a second survey was created in which the experts were asked to rate the item in a binary fashion (essential/important versus marginal/unimportant).
Of the 27 experts invited to complete each survey, 25 (93%) completed the central venous catheterization survey; 22 (81%) completed the thoracentesis survey; and 23 (85%) completed the paracentesis survey. The experts represented 8 specialties from 8 cities within Canada. A total of 22, 32, and 28 items were determined to be essential competencies for central venous catheterization, thoracentesis, and paracentesis, respectively, whereas 47, 38, and 42 competencies were determined to be important, and 8, 13, and 10 were determined to be marginal. The ability to perform real-time direct ultrasound guidance was considered essential only for the performance of central venous catheterization insertion.
Our study presents expert consensus-derived ultrasound competencies that should be considered during the design and implementation of procedural skills training for learners.
o February 25, 2015.
o March 27, 2015.
o May 8, 2015.
B-Lines on Pediatric Lung Sonography
Comparison With Computed Tomography
Sonographic artifacts known as B-lines can been used to estimate alterations of lung parenchyma. Multiple B-lines on sonography are seen in congestive heart disease, interstitial lung disease, respiratory infections, and neonates. The aim of this study was to compare the amount of B-lines on sonography to the extent of parenchymal changes on computed tomography (CT) in children.
Lung sonography was performed on 60 patients aged 18 years and younger referred for chest CT at our institution. B-lines were counted from 5 anterolateral intercostal spaces bilaterally. The CT findings were documented and graded as absent, minimal, partial, or complete.
The number of B-lines on sonography increased consistently with the growing extent of parenchymal changes on CT. The differences in the B-line counts between the patients grouped according to the extent of parenchymal changes on CT were statistically significant except between patients with minimal and no changes ( < .01 Kruskal-Wallis and Tukey tests).
The number of B-lines on sonography correlates with the extent of parenchymal changes on CT. Various parenchymal changes were seen in patients with B-lines on sonography. B-lines were more frequently seen in patients with no changes on CT when imaged during general anesthesia.
o April 2, 2015.
o April 24, 2015.
o May 14, 2015.
Quantitative Ultrasound Elastography With an Acoustic Coupler for Achilles Tendon Elasticity
Measurement Repeatability and Normative Values
The purposes of this study were to measure intraobserver and interobserver repeatability of quantitative elastography using an acoustic coupler for the Achilles tendon, to compare elastographic values among different age groups, and to assess the correlation between quantitative and conventional qualitative measurements.
One hundred asymptomatic Achilles tendons of 50 volunteers were examined. For quantitative elastography, the strain value of the tendon was divided by that of the acoustic coupler with a known Young modulus, and the strain ratio was calculated. B-mode image assessment and qualitative elastography were also performed. Intraobserver repeatability and interobserver repeatability of strain ratio measurements were calculated. The strain ratios were compared among age groups by the Kruskal-Wallis test. Additionally, strain ratios for each B-mode grade and qualitative elastographic grade were compared by the Wilcoxon signed rank test.
Intraobserver repeatability intraclass correlation coefficient (1, 3) values were 0.87 and 0.93, respectively. The correlation coefficient between the observers’ measurements was 0.61. The strain ratio for the 30s age group was 0.27, which was significantly lower than the values for the other age groups ( < .001). Although 97 of 100 tendons were normal on B-mode evaluations, 36 of the 97 tendons were degenerated on qualitative elastography and also had higher strain ratio values than normal tendons.
Quantitative elastography using an acoustic coupler is a reproducible technique for measuring the elasticity of the Achilles tendon. It may detect early tendon degeneration that is not depicted on B-mode imaging.
o January 10, 2015.
o February 14, 2015.
o May 15, 2015.
Sonography of Abdominal Wall Masses and Masslike Lesions
Correlation With Computed Tomography and Magnetic Resonance Imaging
Sonography is usually regarded as a first-line imaging modality for masses and masslike lesions in the abdominal wall. A dynamic study focusing on a painful area or palpable mass and the possibility of ultrasound-guided aspiration or biopsy are the major advantages of sonography. On the other hand, cross-sectional imaging clearly shows anatomy of the abdominal wall; thereby, it is valuable for diagnosing and evaluating the extent of diseases. Cross-sectional imaging can help differentiate neoplastic lesions from non-neoplastic lesions. This pictorial essay focuses on sonographic findings of abdominal wall lesions compared with computed tomographic and magnetic resonance imaging findings.
o March 11, 2015.
o April 27, 2015.
o May 2, 2015.