Ultrasound Elastography In Assessment Research Articles

Ultrasound Elastography Assessment of Knee Intra-Articular Adhesions at Varying Knee Angles.

We aimed to verify the feasibility of using shear wave elastography (SWE) to quantify knee scars and the elastic modulus of scar tissues. Overall, 16 participants underwent SWE assessments and range-of-motion measurement and completed the Knee Injury and Osteoarthritis Outcome Score. The inter-rater reliability for SWE in the suprapatellar bursa, below the patellar tendon, and in the medial and lateral trochlear groove remained within 0.861-0.907. The SWE values in the four regions increased with increasing knee angle, and significant differences were observed between the values for below the patellar tendon and the suprapatellar bursa at knee flexion angles of 60° and 90°. The SWE values of the medial and lateral trochlear groove at 30°, 60°, and 90° knee flexion were higher on the affected side. A negative correlation was observed between the SWE values for the lateral trochlear groove at 0°, 30°, and 60° and those for below the patellar tendon at 0° and the suprapatellar bursa at 30° with both active and passive knee extension. The suprapatellar bursa value at 60° exhibited a positive correlation with both knee flexion and passive knee flexion, whereas that of the suprapatellar bursa at 90° exhibited a positive correlation with both the range of motion and passive range of motion. SWE is a replicable and effective method for detecting scar strength in the knee joint.

Ultrasound elastography assessment of increased carotid artery wall stiffness in human immunodeficiency virus infected patients

Prevalence of cardiovascular diseases is higher in HIV subjects when compared to the general population. The chronic immune stimulation and low grade inflammation are possible causes. Carotid artery strain and motion are proposed as markers of premature atherosclerosis. Seventy-four HIV infected and 75 age-matched control subjects were recruited from a prospective, controlled cohort study (mean age 56 years ± 8; 128 men). Elastography applied to longitudinal ultrasound images of common and internal carotid arteries quantified the cumulated axial strain, cumulated shear strain, cumulated axial translation, and cumulated lateral translation. Presence of plaque was also assessed. Association between elastography biomarkers and HIV status were evaluated with Mann–Whitney tests and multivariate linear regression models. A higher occurrence of carotid plaques was found in HIV infected individuals (p = 0.011). Lower cumulated lateral translations were found in HIV infected subjects on both common and internal carotid arteries (p = 0.037 and p = 0.026, respectively). These observations remained significant when considering multivariable models including common cardiovascular risk factors and clinical characteristics (p< 0.05). Lower cumulated axial strains were also observed in internal carotid arteries when considering both multivariate models (p< 0.05). Lower translation and strain of the carotid artery wall in HIV infected individuals, which indicate increased vessel wall stiffness, could be new biomarkers of premature atherosclerosis.

Ultrasound elastography in assessment of salivary glands involvement in primary Sjögren's syndrome

ObjectiveOur study aimed to assess the pathological sonoelastographic changes in the major salivary glands and to demonstrate the diagnostic effectiveness of Sonoelastography as an additional method to US in Sjögren's syndrome. MethodsFifty eight patients with primary Sjögren's syndrome (pSS) were selected according to the American-European Consensus Group Classification criteria. Twenty five healthy volunteers involved in this study. All patients were evaluated with B-mode and elastography by using Hitachi EUB 7500 digital ultrasound equipment. All subjects were female. The sonoelastography examination, which allowed us to assess the elasticity of the parenchyma, was performed and strain ratios were measured by comparing with the adjacent tissues. ResultsStatistically significant differences were found between the pSS and control groups for the elastographic scores and strain ratios (p < 0.001). The highest sensitivity and specificity levels were obtained when the strain ratio cut-off value was taken as 1.55 for the submandibular gland and 2.45 for the parotid gland (sensitivity and specificity were 83% and 88% respectively for the submandibular gland and 83% and 92% respectively for the parotid gland). However, no statistically significant differences were found between the disease duration and the elasticity scores or strain ratios in pSS group (p > 0.05). ConclusionUS examination is an efficient method to assess major salivary gland involvement in the diagnosis of pSS. Sonoelastography is a modality which can contribute to the diagnosis by improving specificity in the differential diagnosis of pSS. Strain ratio measurement, which is a semi-quantitative method, increases the diagnostic effectiveness by providing high sensitivity, specificity, and negative predictive values.

Ultrasound elastography assessment of the median nerve in leprosy patients.

We sought to compare median nerve elasticity between leprosy patients (LPs) and healthy volunteers (HVs) using ultrasound elastography (UE). Two radiologists independently measured the strain ratio of the median nerve/flexor digitorum superficialis muscle (MN/FDSM) of 18 LP and 18 HV using real-time freehand UE. Statistical analysis included intra-class correlation coefficients (ICC) and Mann-Whitney test. The MN/FDSM strain ratios of the LP and HV were 2.66 ± 1.30 and 3.52 ± 0.93, respectively (P < 0.05). We observed a significantly lower MN/FDSM strain ratio in LP with reactions (types 1 and 2 cutaneous reactions associated with or without neuritis) (2.30 ± 0.91) compared with LP without reactions (3.60 ± 1.70). We found no significant differences between HV and LP without reactions. The intra- and inter-observer ICCs were 0.50 (95% confidence interval [CI], 0.11-0.72) and 0.34 (95% CI, 0.28-0.52), respectively. MN/FDSM strain ratios were significantly lower in LP with reactions. UE may be useful for nerve elasticity evaluation in leprosy. Muscle Nerve 56: 393-398, 2017.

Ultrasound elastography in evaluation of sternocleidomastoid fibrosis after radiotherapy for nasopharyngeal carcinoma

Objective To investigate the feasibility and clinical value of ultrasound elastography in assessment of sternocleidomastoid fibrosis in patients after radiotherapy for nasopharyngeal carcinoma. Methods Forty-five patients with nasopharyngeal carcinoma after radiotherapy (study group) and 52 healthy volunteers (control group) underwent ultrasound elastography.Bilateral sternocleidomastoid elasticity score, thickness, width, resistance index(RI), and pulsatility index(PI) were analyzed and compared. Results The sternocleidomastoid elastography in study group was mainly blue, and that in control group was mainly green. The difference of sternocleidomastoid elasticity score, width, and thickness was significant between study group and control group (P 0.05). Conclusions Ultrasound elastography could be effectively and noninvasively used for evaluating the sternocleidomastoid fibrosis in patients after radiotherapy for nasopharyngeal carcinoma. It has a potential clinical value in the grading and classification of fibrosis. Key words: Elasticity imaging techniques; Nasopharyngeal neoplasms; Radiotherapy-related complications; Sternocleidomastoid fibrosis

Ultrasound elastography assessment of bone/soft tissue interface

We report on the use of elastographic imaging techniques to assess the bone/soft tissue interface, a region that has not been previously investigated but may provide important information about fracture and bone healing. The performance of axial strain elastograms and axial shear strain elastograms at the bone/soft tissue interface was studied ex vivo on intact and fractured canine and ovine tibias. Selected ex vivo results were corroborated on intact sheep tibias in vivo. The elastography results were statistically analyzed using elastographic image quality tools.The results of this study demonstrate distinct patterns in the distribution of the normalized local axial strains and axial shear strains at the bone/soft tissue interface with respect to the background soft tissue. They also show that the relative strength and distribution of the elastographic parameters change in the presence of a fracture and depend on the degree of misalignment between the fracture fragments. Thus, elastographic imaging modalities might be used in the future to obtain information regarding the integrity of bones and to assess the severity of fractures, alignment of bone fragments as well as to follow bone healing.

Role of ultrasound elastography in assessment of indeterminate thyroid nodules

PurposeTo evaluate the role of ultrasound elastography as an additional technique in differentiating US indeterminate thyroid nodules in order to decrease the number of tissue biopsies. MethodsWe evaluated 30 patients with 36 indeterminate thyroid nodules based on US, criteria, by US elastography, using both the elastography score and strain ratio. Baseband US data were downloaded for off-line analysis. Elastographic maps (color coding) and thyroid stiffness index (strain ratio) were calculated for all nodules, with histopathological results being the standard reference. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff strain ratio for separating benign and malignant thyroid nodules. ResultsMalignant nodules had a higher degree of color and strain ratio compared to benign nodules, with a statistically significant difference (p<0.05). Nodules with an elastography score of 2 were benign, while those with an elastography score of 4 and 5 were mostly malignant. Malignancy could not be excluded using ultrasound elastography criteria only, in nodules with a score of 3. The sensitivity and specificity of the US-elastography strain color coding for thyroid cancer diagnosis were 91% and 72% respectively. Using ROC analysis, the optimal cutoff strain ratio for separating benign and malignant thyroid nodules was found to be 1.6 with a calculated 89% sensitivity and 70% specificity. The overall accuracy of strain color was slightly better than strain ratio, 91% compared to 86% respectively. ConclusionUltrasound elastography is an easy, non-invasive and rapid technique that can be routinely used in thyroid US scans to select cases for FNAC, and decrease the number of unnecessary biopsies, and consequently decrease the hazards and costs. However, future advances in image acquisition and reconstruction algorithms are required to improve the image quality and clinical usefulness of this technique.

Ultrasound Elastography Combined With BI-RADS–US Classification System: Is It Helpful for the Diagnostic Performance of Conventional Ultrasonography?

PurposeTo evaluate the additive diagnostic performance of ultrasound elastography (UE) to ultrasound (US) with the 2003 or 2013 Breast Imaging Reporting and Data System (BI-RADS)–US classification systems for the differentiation of benign and malignant breast lesions. MethodsFrom June 2010 to December 2012, 738 women with 770 breast lesions were recruited into this retrospective study. Breast lesions were evaluated separately by US, UE, and both. US assessment was based on the 2003 or 2013 BI-RADS–US, and UE assessment was based on a previously reported 5-point scale. Diagnostic performance of US, UE, and both was compared. ResultsBefore category 4 lesions were subdivided, the area under the receiver operating characteristic curve (AUC) for US, UE, and both were, respectively, 0.735, 0.877, 0.878 (P < .01). When subcategories of 4 lesions were considered, the AUC for US, UE, and both were, respectively, 0.865, 0.877, and 0.883 (P > .05). Adding UE to analysis of 4A lesions can decrease the percentages of malignancy to 2.56%. ConclusionWhen the 2003 BI-RADS was considered, UE could give US some help in differentiating breast lesions. However, when the 2013 BI-RADS was considered, UE gave little help to US, although it reduced unnecessary biopsies of benign category 4A lesions.

A Hertzian contact mechanics based formulation to improve ultrasound elastography assessment of uterine cervical tissue stiffness

Clinical practice requires improved techniques to assess human cervical tissue properties, especially at the internal os, or orifice, of the uterine cervix. Ultrasound elastography (UE) holds promise for non-invasively monitoring cervical stiffness throughout pregnancy. However, this technique provides qualitative strain images that cannot be linked to a material property (e.g., Young's modulus) without knowledge of the contact pressure under a rounded transvaginal transducer probe and correction for the resulting non-uniform strain dissipation. One technique to standardize elastogram images incorporates a material of known properties and uses one-dimensional, uniaxial Hooke's law to calculate Young's modulus within the compressed material half-space. However, this method does not account for strain dissipation and the strains that evolve in three-dimensional space. We demonstrate that an analytical approach based on 3D Hertzian contact mechanics provides a reasonable first approximation to correct for UE strain dissipation underneath a round transvaginal transducer probe and thus improves UE-derived estimates of tissue modulus. We validate the proposed analytical solution and evaluate sources of error using a finite element model. As compared to 1D uniaxial Hooke's law, the Hertzian contact-based solution yields significantly improved Young's modulus predictions in three homogeneous gelatin tissue phantoms possessing different moduli. We also demonstrate the feasibility of using this technique to image human cervical tissue, where UE-derived moduli estimations for the uterine cervix anterior lip agreed well with published, experimentally obtained values. Overall, UE with an attached reference standard and a Hertzian contact-based correction holds promise for improving quantitative estimates of cervical tissue modulus.

FRI0250 Involvement of Salivary Glands in Primary SjÖGren's Syndrome. Elastographic Assessment and Correlations with Ultrasonographic Findings

BackgroundPrimary Sjögren's Syndrome (SS) is an autoimmune disease characterized by early inflammatory abnormalities of salivary and lacrimal glands and subsequent progressive destruction and local fibrosis. Imaging evaluation of salivary gland...

Qualitative ultrasound elastography assessment of benign thyroid nodules: Patterns and intra-observer acquisition variability

Purpose:To report and evaluate qualitative elastography patterns by using gray-scale and Doppler ultrasound (US) in patients presenting with benign thyroid nodules and to evaluate the reproducibility of US elastography examinations.Materials and Methods:Institutional review board approval was obtained, and all patients provided informed consent. Over a 3-month time period, all consecutive adult patients were referred to our institution to undergo a thyroid nodule fine-needle aspiration biopsy (FNAB) procedure. Patients presenting with benign cytology according to the Bethesda 2008 classification were prospectively enrolled in the study. Each thyroid nodule was assessed by using gray-scale, Doppler US, and elastography acquisitions by a single operator (A. L.). Multiple elastography acquisitions per thyroid nodule were performed and elastography scorings of the nodules were compared with each other.Results:Nineteen patients (16 women and 3 men, mean age 58 years) with 22 thyroid nodules were included in the present study. Elastographic patterns 1, 2, and 3 were reported (23% nodules showed pattern 3). The elastography pattern showed a strong variability in 13 nodules (59%). The elastography acquisition result variability involved the “malignant” pattern 3 in 36% of cases.Conclusion:Almost one-third of benign thyroid nodules displayed pattern 3 on qualitative US elastography. The intra-observer variability of the benign thyroid elastography scoring is wide, thus limiting the thyroid nodule US examination accuracy. In FNAB-proven benign thyroid nodules, elastography pattern 3 is frequent and cannot be used as a strong indicator of thyroid malignancy.

Semi-Quantitative and Qualitative Assessment of Breast Ultrasound Elastography in Differentiating Between Malignant and Benign Lesions

The purpose of this study was to evaluate the diagnostic value of qualitative and semi-quantitative assessment of ultrasound elastography in differentiating between benign and malignant breast lesions. This prospective study was conducted in two tertiary medical centers. Consecutive B-mode ultrasound and real-time elastographic images were obtained for 67 malignant and 101 benign breast lesions in 168 women. Four experienced radiologists analyzed B-mode ultrasound alone and B-mode ultrasound combined with elastography independently. Conventional ultrasound findings were classified according to the American College of Radiology Breast Imaging Reporting and Data System classification. The elastographic assessment was based on qualitative and semi-quantitative parameters (i.e., strain pattern, width ratio, strain ratio). The sensitivity and specificity of combined elastography and conventional ultrasound were significantly higher than that of conventional ultrasound alone. The sensitivity, specificity, positive predictive value and negative predictive value was 97%, 61.4%, 62.5% and 96.8%, respectively, for conventional ultrasound and 100%, 93%, 99% and 90%, respectively, for combined technique. The semi-quantitative assessment with strain ratio and width ratio in elastography were the most useful parameters in differentiating between benign and malignant breast lesions. Cut-off point values for width ratio of more than 1.1 and strain ratio of more than 5.6 showed a high predictive value of malignancy with specificities of 84% and 76%, respectively (p < 0.001). This combined technique also had the best results in detecting carcinoma and could reduce the need of unnecessary biopsy for benign lesions with indeterminate or equivocal features.

Value of Ultrasound Elastography in Assessment of Enlarged Cervical Lymph Nodes

To investigate the value of ultrasound elastography (UE) in the differentiation between benign and malignant enlarged cervical lymph nodes (LNs). B-mode ultrasound, power Doppler imaging and UE were examined to determine LN characteristics. Two kinds of methods, 4 scores of elastographic classification and a strain ratio (SR) were used to evaluate the ultrasound elastograms. The cutoff point of SR had high utility in differential diagnosis of benign and malignant of cervical lymph nodes, with good sensitivity, specificity and accuracy. UE is an important aid in differential diagnosis of benign and malignant cervical LNs.

Ultrasound Elastography Assessment of Skin Involvement in Systemic Sclerosis: Lights and Shadows

To assess skin elasticity in systemic sclerosis (SSc) by using a new imaging modality, ultrasound elastography (UE). Our study included 18 consecutive patients with SSc and 15 healthy controls. Modified Rodnan skin score, physical examination, and assessment of organ involvement were performed. UE was carried out on the middle forearm and on the fingers of the dominant arm. The echo signals recorded in real time during freehand operations of probe compression and relaxation produced images representing tissue elasticity, consisting of translucent colored bands superimposed on the B-mode ultrasonographic images. The color scale varied within a large band spectrum from red, indicative of soft and highly elastic tissue, to blue, which denoted hard and barely elastic tissue. On the forearm of all patients, UE showed a homogeneous blue area corresponding to the dermis visualized in a B-mode ultrasonographic image; in controls, a blue pattern was never detected and a predominance of green with sporadic areas of pale blue was observed. At sequential evaluations, UE of fingers produced inconstant and changeable colored areas. The imaging pattern observed in the forearm of patients with SSc may represent the reduction of strain in the dermis due to loss of elasticity. The variable pattern obtained by finger evaluation demonstrated that UE can assess skin involvement in SSc only in those areas where the dermis is known to be thicker and where the bone hyperreflection is minimal. Further studies are needed to confirm our results and determine the validity of this new imaging modality.