Is Ultrasound Fusion a Reasonable Replacement for Computed Tomography in Guiding Abdominal Interventions?Journal of Ultrasound in Medicine June 2016 35:1131-1141; Published Online First April 18, 2016, doi:10.7863/ultra.15.06007
Ultrasound Elastography for Distinction Between Parathyroid Adenomas and Thyroid NodulesJournal of Ultrasound in Medicine June 2016 35:1277-1282; Published Online First May 5, 2016, doi:10.7863/ultra.15.07043
Liver Fibrosis Evaluation Using Real-time Shear Wave Elastography in Hepatitis C–Monoinfected and Human Immunodeficiency Virus/Hepatitis C–Coinfected PatientsJournal of Ultrasound in Medicine June 2016 35:1299-1308; Published Online First May 5, 2016, doi:10.7863/ultra.15.08066
Detection of Intraneural Median Nerve Microvascularity Using Contrast-Enhanced Sonography: A Pilot StudyJournal of Ultrasound in Medicine June 2016 35:1309-1316; Published Online First May 5, 2016, doi:10.7863/ultra.15.07012
Modeling, Production, and Testing of an Echogenic Needle for Ultrasound-Guided Nerve BlocksJournal of Ultrasound in Medicine June 2016 35:1319-1323; Published Online First May 9, 2016, doi:10.7863/ultra.15.06022
Is Ultrasound Fusion a Reasonable Replacement for Computed Tomography in Guiding Abdominal Interventions?
Objectives—To compare the diagnostic yield, complication rate, and procedure length of ultrasound fusion-guided liver biopsy to the diagnostic yield, complication rate, and procedure length of computed tomography (CT)-guided liver biopsy; to measure the average ionizing radiation dose that patients are exposed to during a typical CT-guided liver biopsy procedure; and to present relevant and interesting cases of ultrasound fusion-guided abdominal interventions to describe the efficacious use of the technology.
Methods—A retrospective analysis of 63 patients who had image-guided liver biopsies performed at our institution was completed. Patient records were divided into 2 groups according to the type of image guidance used during the procedure (ultrasound fusion versus CT), and data were compared by the χ2 test, Student t test, and Mann-Whitney U test.
Results—The diagnostic yields and complication rates were not statistically significantly different between the modalities. The average procedure durations were significantly different: ultrasound fusion-guided biopsy, 31.63 minutes; compared to CT-guided biopsy, 61.67 minutes (P = .003).
Conclusions—Diagnostic yields and complication rates were comparable for ultrasound fusion and CT. However, the average procedure duration for an ultrasound fusion-guided liver biopsy was approximately half that of CT-guided liver biopsy, likely increasing both cost-effectiveness and patient satisfaction.
Comparison of Two Injection Techniques for Intra-articular Hip Injections
Objectives—Intra-articular hip joint injections have traditionally relied on the use of image guidance to confirm intra-articular needle placement. Musculoskeletal ultrasound (US) has emerged as a popular tool to aid the clinician in performing intra-articular hip injections. Modern automated injection delivery systems are commercially available and may offer the potential to optimize clinical efficiency while limiting procedural morbidity. The purpose of this study was to compare patient-reported outcomes and clinical efficiency between two US-guided intra-articular hip injection techniques. The hypothesis was that the use of an automated delivery system for US-guided intra-articular hip joint injections would show superiority in clinical efficiency over traditional syringe injections.
Methods—This study was a level 1 randomized prospective postmarket clinical evaluation. Forty patients were randomly assigned to undergo a single intra-articular corticosteroid injection of the hip using either an automated delivery system (Navigator Delivery System; Carticept Medical, Inc, Alpharetta, GA) or a traditional syringe injection. Enrolled patients were prospectively followed at 1, 6, and 12 weeks after injection. A battery of patient-reported outcomes were collected at baseline and again at 1, 6, and 12 weeks after injection. Preparation times were documented for all injections.
Results—Forty patients met inclusion criteria and were enrolled. Twenty patients were randomly assigned to receive US guided intra-articular hip injections using the automated system (group A), and 20 patients were treated with standard syringe injections (group B). Body mass index, smoking history, symptom duration, baseline patient-reported outcomes, and demographic data were similar between groups. Improvements from baseline scores were noted at all time points for all patient-reported outcomes regardless of the injection technique used. However, no significant differences were noted at any time point for any of the patient-reported outcomes based on which injection delivery system was used. Statistically significant differences were noted at 6 and 12 weeks for the subjective global assessment score, which favored the use of the automated delivery system over the standard injection technique (6 weeks,P = .029; 12 weeks, P = .028). Between the two injection procedures, there was no difference in pain experienced by the patient (mean Visual Analog Scale pain score ± SEM: group A, 34.9 ± 6.49; group B, 34.5 ± 5.99; P = .960). Body mass index did not influence pain associated with an intra-articular hip injection (P = .870); however, younger patient age was found to be an independent predictor of increased pain associated with injection (P = .011). Although there were no differences among male or female patients in hip injection pain based on the delivery method, statistically significant differences were encountered between male and female patients, irrespective of treatment assignment (male/female: group A, 25.1/41.4; group B, 26.7/46.1; P= .049). Among patients with a smoking history, large differences were noted for injection pain when data for both groups were pooled, regardless of the delivery method (no history, 30.0 ± 4.86; smoking history, 40.8 ± 9.94). Clinical efficiency (as measured by injection preparation time) was found to be inferior for the automated system compared to traditional syringe injection (P < .0001).
Conclusions—Use of an automated delivery system for US-guided intra-articular hip injections did not show superior efficiency or patient comfort over traditional syringe injections. Intra-articular corticosteroid injections led to clinically and statistically significant improvements in pain and function for patients with intra-articular hip pain, irrespective of the delivery method. Smoking history and female sex were independent predictors of increased pain associated with intra-articular hip joint injections.
Ultrasound Elastography for Distinction Between Parathyroid Adenomas and Thyroid Nodules
Objectives—The aim of this study was to detect the level of stiffness of parathyroid adenomas and to distinguish them from benign and malignant thyroid nodules using ultrasound elastography with acoustic radiation force impulse imaging.
Methods—Twenty-one patients with parathyroid adenomas and 71 patients with thyroid nodules were evaluated by acoustic radiation force impulse imaging in this study. Acoustic radiation force impulse elastograms were obtained after evaluation of the thyroid nodules, which were predicted to undergo fine-needle aspiration biopsy, and patients with a diagnosis of hyperparathyroidism, which was identified by sonography at the same time.
Results—An analysis of mean shear wave velocity (SWV) values for parathyroid adenomas and thyroid nodules showed that parathyroid adenomas had significantly higher stiffness levels compared to benign thyroid nodules (mean SWV ± SD, 3.09 ± 0.75 versus 2.20 ± 0.39 m/s; P < .001) and lower stiffness levels compared to malignant thyroid nodules (mean SWV, 3.09 ± 0.75 versus 3.59 ± 0.43 m/s; P < .001).
Conclusions—Acoustic radiation force impulse imaging has high sensitivity and specificity for differentiating parathyroid adenomas from benign and malignant thyroid nodules. As an adjunctive tool, it can help distinguish parathyroid adenomas from thyroid nodules, including posteriorly located nodules.
Sonographic Determination of Type in a Fetal Imperforate Anus
Objectives—The purpose of this study was to determine the type of an imperforate anus by using sonography in the prenatal period.
Methods—This retrospective study evaluated the fetal anus in all pregnant women, including low- and high-risk populations, between February 2010 and November 2013. High-type imperforate anuses were diagnosed by prenatal sonography when the anal sphincter muscles and anal canal mucosa were not visible. Low-type imperforate anuses were prenatally suspected when at least 1 of the following was present: (1) a small anus; (2) no visible anal mucosa; or (3) close location of the genitalia by the anus without a visible perineal body, particularly in a female fetus.
Results—Among the 9499 fetuses, 41 were prenatally suspected of having an imperforate anus, and 32 were confirmed to have this disorder. During the same study period, there were 11 false-negative cases, for a diagnostic sensitivity rate of 74%. All 9 fetuses who were confirmed to have a normal anus were prenatally suspected of having a low-type imperforate anus. Among the 32 fetuses with a confirmed imperforate anus, 19 were confirmed to have a high or intermediate type and 13 to have a low type. The type in 3 fetuses was incorrectly determined prenatally.
Conclusions—Although an imperforate anus is not always diagnosed prenatally, its type can be determined by prenatal sonography.
Liver Fibrosis Evaluation Using Real-time Shear Wave Elastography in Hepatitis C–Monoinfected and Human Immunodeficiency Virus/Hepatitis C–Coinfected Patients
Objectives—A few studies have evaluated real-time shear wave elastography (SWE) for assessing liver fibrosis by measuring liver stiffness in patients with chronic hepatitis C virus (HCV) infection, but they excluded human immunodeficiency virus/HCV–coinfected patients. We investigated the diagnostic performance of liver stiffness measured by SWE as a noninvasive predictor of liver fibrosis in HCV using liver biopsy as a reference standard, including monoinfected and coinfected patients.
Methods—We measured liver stiffness in patients with HCV undergoing liver biopsy (METAVIR fibrosis staging).
Results—Eighty patients (53 monoinfected and 27 coinfected) were included. There was a significant correlation between liver stiffness and fibrosis stage (ρ = 0.685; P < .001). Areas under the receiver operating characteristic curve were 0.841, 0.879, and 0.975 when comparing fibrosis stages F0–F1 versus F2–F4, F0–F2 versus F3–F4, and F0–F3 versus F4, respectively. Suggested cutoff values were 8.5 kPa for F2, 10.4 kPa for F3, and 11.3 kPa for F4, with sensitivity and specificity of 81% and 84%, 81% and 95%, and 100% and 90%. There was no significant difference between the liver stiffness of monoinfected and coinfected patients (P = .453). When combining SWE with the fibrosis-4 score, accuracy increased from 82% to 88% and from 88% to 96%, with incongruent results of 26% and 29%, for F0–F1 versus F2–F4 and F0–F2 versus F3–F4.
Conclusions—Shear wave elastography of the liver is an effective noninvasive predictor of liver fibrosis in patients with HCV. There was no significant difference between monoinfected and coinfected patients; hence, the same cutoff values can be used for both groups. Combination of SWE with the fibrosis-4 score leads to higher accuracy, although at the expense of inconclusive results in some patients.
Detection of Intraneural Median Nerve Microvascularity Using Contrast-Enhanced Sonography
A Pilot Study
Objectives—Demonstrating vascularity within the human median nerve may be difficult using power Doppler sonography. To this end, a pilot study documenting contrast-enhanced vascularity of the median nerve was conducted.
Methods—Patients undergoing contrast-enhanced transthoracic echocardiography were recruited for this study (n = 24). During echocardiography, a simultaneous contrast-enhanced sonographic examination of the median nerve was conducted. The study and study protocol were built from preclinical evidence. Image analysis was based on the power Doppler pixel intensity within a defined region of interest to obtain quantitative data representing the average pixel intensity, maximum pixel intensity, and power Doppler pixel dot count. Semiquantitative data representing the power Doppler dot count grading were also obtained.
Results—Spearman correlations between analytical methods showed strong positive, statistically significant (P< .05) correlations between the average pixel intensity and maximum pixel intensity and between the power Doppler dot count and dot count grading. Statistically significant increases in the average pixel intensity and power Doppler dot count were seen at all but 1 time point throughout the contrast-enhanced sonographic examination when compared to precontrast administration. Statistically significant increases in the maximum pixel intensity were seen at all but 4 time points.
Conclusions—These pilot results represent early evidence that contrast-enhanced sonography can be used to image median nerve vascularity. In this convenience sample, median nerve contrast-enhanced sonographic data collection was feasible, safe, and consistent.
Modeling, Production, and Testing of an Echogenic Needle for Ultrasound-Guided Nerve Blocks
We have designed, produced, and tested an echogenic needle based on a sawtooth pattern where the height of the tooth was 1.25 times the wavelength of the ultrasound transducer. A numeric solution to the time-independent wave equation (Helmholtz equation) was used to create a model of backscattering from a needle. A 21-gauge stainless steel prototype was manufactured and tested in a water bath. Backscattering from the needle was compared to theoretical predications from our model. Based on these results, an 18-gauge prototype needle was fabricated from stainless steel and tested in a pig cadaver. This needle was compared to a commercial 18-gauge echogenic needle (Pajunk Medical Systems, Tucker, GA) by measuring the brightness of the needle relative to the background of sonograms of a needle in a pig cadaver. The backscattering from the 21-gauge prototype needle reproduced the qualitative predictions of our model. At 30° and 45° of insonation, our prototype performed equivalently to the Pajunk needle. At 60°, our prototype was significantly brighter than the Pajunk needle (P = .017). In conclusion, we chose a model for the design of an echogenic needle and modeled it on the basis of a solution to the Helmholtz equation. A prototype needle was tested in a water bath and compared to the model prediction. After verification of our model, we designed an 18-gauge needle, which performed better than an existing echogenic needle (Pajunk) at 60° of insonation. Our needle will require further testing in human trials.
Sonography of Responsive Versus Nonresponsive Ectopic Pregnancies
This case series describes changes in size, vascularity, and cul-de-sac fluid in 30 patients with ectopic pregnancies who were treated with systemic methotrexate. Pretreatment and posttreatment transvaginal sonography of the ectopic pregnancies was performed with color Doppler imaging, and the images were assessed for changes in size, vascularity, and cul-de-sac free fluid. There was a trend for nonresponders to show increased vascularity on serial examinations, although this finding was also seen in a single responder. There was also a trend for nonresponders with increased vascularity to be associated with a greater increase in β-human chorionic gonadotropin levels and responders with decreased vascularity to be associated with a greater decrease in β-human chorionic gonadotropin levels.