Elastography For Detection Research Articles

Comparison of Strain and Shear Wave Elastography in Prostate Cancer Detection.

The aim of the study was to compare strain elastography with shear wave elastography in prostate cancer detection by comparing data gained during elastography with histological analysis after prostatectomy. Thirty patients with prostate cancer qualified for radical prostatectomy were enrolled into the study. All patients underwent transrectal strain elastography and shear wave elastography during pre-surgical evaluation. In each prostate, 36 regions were evaluated separately whether there was a suspicious prostate cancer lesion or not. Subsequently, the same regions were analyzed during histological analysis of the resected gland. Strain elastography and shear wave elastography (overall stiffness cutoff value=35 kPa) in our study were characterized by overall sensitivities of 58.9% and 65.3% and specificities of 71.8% and 70.2%, respectively. Cutoff values specific to the zones in the shear wave elastography examination (peripheral zone: 35 kPa, transitional zone: 45 kPa) were characterized by an overall prostate cancer detection sensitivity and specificity of 63.4% and 73% respectively. Shear wave elastography examination revealed a higher sensitivity versus strain elastography, 63.4% versus 58.9% (p=0.038, p < 0.05), and comparable specificity, 73.0% versus 71.8% (p=0.547, p > 0.05), respectively. Sensitivity in prostate cancer detection for both methods is higher for larger lesions (except Gleason score 5 massive lesions in strain elastography). Controversially we observed a decrease in sensitivity for strain elastography in the detection of lesions with a large diameter and a Gleason score of 5 near the prostate capsule. Overall sensitivity in the diagnosis of prostate cancer is more significant for shear wave elastography versus strain elastography.

Use of Transient Elastography in Detection of Liver Fibrosis in Psoriasis Patients - A Cross- Sectional Study.

Background and Aims:The risk of liver damage in psoriasis increases with increase in cumulative dose of methotrexate and guidelines suggest use of liver biopsy for risk mitigation. Recently, transient elastography (TE) has been used for detection of liver fibrosis. Most studies for TE are in hepatitis B and C patients. However, psoriasis patients have risk factors like metabolic syndrome which predisposes them to increased risk of liver damage due to methotrexate. This underlying liver disease may change the TE values in patients with psoriasis. The aim of this study is to determine utility of transient elastography in detection of liver fibrosis in patients with psoriasis.Methods:82 patients with chronic plaque psoriasis requiring systemic therapy or already on methotrexate were included in the study. Clinical examinationand biochemical investigations were conducted. Data were analysed using STATA 12.1 (Texas, USA). Univariate analysis using Chi-square and independent't-test' was carried out to evaluate the association between categorical variables and outcomes.Results:Patients consists of 62 males and 20 females. TE value >7 kPa (kilopascal) were seen in 23 patients and <7 kPa were seen in 59 patients. Value of >7 kPa was significantly associated with age, waist circumference, diastolic blood pressure, fasting and post prandial blood sugar, AST, PASI and presence of metabolic syndrome. Cumulative methotrexate dose was not significantly associated with high TE value. Mean TE value in patients with metabolic syndrome was significantly higher.Limitations:Small sample size and inability to confirm TE findings on liver biopsy.Conclusion:TE is a non-invasive tool for detection of liver fibrosis. Value of >7 kPa correlates with liver fibrosis in most chronic liver diseases. However, high prevalence of metabolic syndrome in psoriasis patientsmayconfound utility of TE for monitoring of methotrexate toxicity.

Accuracy of transrectal strain elastography in detection of prostate cancer

Background: Elastography has emerged as a boon in aiding diagnosis of various neoplastic conditions. Strain elastography helps in differentiating hard lesions from the normal tissue on a real-time basis and targeting biopsies of the same described by other authors in various conditions. We assess a series of cases for the detection of prostate cancer using strain elastography of prostate. Aims: The aim of this study was to assess the accuracy of transrectal strain elastography in diagnosis of prostate cancer. Materials and Methods: This is an observational cross-sectional, prospective study. Transrectal strain elastography was performed using a C-10 3 v endocavity probe with elastography software and was compared against biopsy results on 25 adult male patients with raised prostate-specific antigen levels. Statistical significance of qualitative data across two study groups was tested using the Chi-square test or Fisher's exact test. The entire data were analyzed using SPSS version 16.0, Inc., Chicago, software for Microsoft Windows. Results: Ten (40%) out of 25 patients demonstrated carcinoma prostate, 14 patients had benign prostatic hyperplasia, and 1 had prostatic abscess. Transrectal real-time elastography scores in patients with carcinoma patient were higher than those of benign conditions, i.e., 3 and 4 scores with accuracy of 92%, sensitivity of 85.7%, and specificity of 94.4%. Conclusions: The overall accuracy of strain elastography was 92%, which enhanced the diagnostic yield in prostate carcinoma. Real-time strain elastography is a highly sensitive and specific technique for diagnosing prostatic carcinoma and guiding the prostate biopsy.

FRI-439 - Magnetic Resonance Elastography versus Transient Elastography in detection of fibrosis in nonalcoholic fatty liver disease: A systematic review and meta-analysis of individual participant date

FRI-439 - Magnetic Resonance Elastography versus Transient Elastography in detection of fibrosis in nonalcoholic fatty liver disease: A systematic review and meta-analysis of individual participant date

Hybrid Technology Fusion MRI/US and Sonoelastography in Diagnosis of Fatty Degeneration and Atrophy of Supraspinatus Muscle of the Shoulder

Evaluation of the rotator cuff muscles is of value for surgical indications and successful postoperative prognosis. Ultrasound is widely used for detection of rotator cuff tears, but it’s role in evaluation of the rotator cuff muscles is not yet defined. A new method Fusion MRI/US with elastography is able to show differences in tissue stiffness, and a simultaneous combination of two methods helps to overcome limitations from US – narrow field of view, and from MRI – impossibility for real time examination and low space resolution.Purpose.To investigate diagnostic performance and interobserver reliability of US elastography and to study possibilities of Fusion MRI/US technique in grading fatty degeneration and atrophy of the supraspinatus muscle.Materials and methods.72 patients from 128 with shoulder pain and disability with written diagnostic confirm were specially selected for the study with US elastography and MRI and 29 patients were enrolled for Fusion MRI/US study. Oblique sagittal scans through the supraspinatus muscle were performed during US elastography study in the standard manner for comparance with MRI. The amount of fatty degeneration was graded according to the modified Goutallier five-point scale, with use of a 3-point scale – with US elastography. US results for grade of atrophy and fatty degeneration were retrospectively reviewed by 2 blinded to each other results experts. Sensitivity and interobserver reliability was estimated.Results.The sensitivity of standard US in comparance to US elastography in assessment of muscle atrophy with the reference to MRI was 53% and 76%, respectively. The sensitivity of US and US elastography increased with increasing of the grade of muscle atrophy. The sensitivity of US and US elastography in detection of fatty degeneration was slightly better 65% and 85%, respectively. US elastography were more sensitive in evaluation of fatty degeneration in full thickness than in partial thickness rotator cuff tears. In all cases of full thickness tears US with elastography had a 100% sensitivity in assessment of atrophy and fatty degeneration in the reference to MRI. While in partial tears the sensitivity decreased to 66%. The agreement between MRI and US elastography for the grade of fatty degeneration of the supraspinatus was substantial (kappa = 0.78). The interobserver reliability for US was fair (kappa = 0.41), and for US elastography substantial (kappa=0,71).Conclusion. Sonoelastography helps to increase the diagnostic performance of US in identifying and grading fatty degeneration and atrophy of the supraspinatus. US with elastography can be used as a primary modality for fatty changes and atrophy of the supraspinatus.

264 - Magnetic Resonance Elastography vs Transient Elastography in Detection of Fibrosis and Noninvasive Measurement of Steatosis in Patients with Biopsy-Proven Nonalcoholic Fatty Liver Disease

264 - Magnetic Resonance Elastography vs Transient Elastography in Detection of Fibrosis and Noninvasive Measurement of Steatosis in Patients with Biopsy-Proven Nonalcoholic Fatty Liver Disease

Covering the Cover

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THU-477 - Magnetic resonance elastography vs. transient elastography in detection of fibrosis and noninvasive measurement of steatosis in patients with biopsy-proven nonalcoholic fatty liver disease

THU-477 - Magnetic resonance elastography vs. transient elastography in detection of fibrosis and noninvasive measurement of steatosis in patients with biopsy-proven nonalcoholic fatty liver disease

Magnetic Resonance Elastography vs Transient Elastography in Detection of Fibrosis and Noninvasive Measurement of Steatosis in Patients With Biopsy-Proven Nonalcoholic Fatty Liver Disease

Magnetic resonance imaging (MRI) techniques and ultrasound-based transient elastography (TE) can be used in noninvasive diagnosis of fibrosis and steatosis in patients with nonalcoholic fatty liver disease (NAFLD). We performed a prospective study to compare the performance of magnetic resonance elastography (MRE) vs TE for diagnosis of fibrosis, and MRI-based proton density fat fraction (MRI-PDFF) analysis vs TE-based controlled attenuation parameter (CAP) for diagnosis of steatosis in patients undergoing biopsy to assess NAFLD. We performed a cross-sectional study of 104 consecutive adults (56.7% female) who underwent MRE, TE, and liver biopsy analysis (using the histologic scoring system for NAFLD from the Nonalcoholic Steatohepatitis Clinical Research Network Scoring System) from October 2011 through May 2016 at a tertiary medical center. All patients received a standard clinical evaluation, including collection of history, anthropometric examination, and biochemical tests. The primary outcomes were fibrosis and steatosis. Secondary outcomes included dichotomized stages of fibrosis and nonalcoholic steatohepatitis vs no nonalcoholic steatohepatitis. Receiver operating characteristic curve analyses were used to compare performances of MRE vs TE in diagnosis of fibrosis (stages 1-4 vs 0) and MRI-PDFF vs CAP for diagnosis of steatosis (grades 1-3 vs 0) with respect to findings from biopsy analysis. MRE detected any fibrosis (stage 1 or more) with an area under the receiver operating characteristic curve (AUROC) of 0.82 (95% confidence interval [CI], 0.74-0.91), which was significantly higher than that of TE (AUROC, 0.67; 95% CI, 0.56-0.78). MRI-PDFF detected any steatosis with an AUROC of 0.99 (95% CI, 0.98-1.00), which was significantly higher than that of CAP (AUROC, 0.85; 95% CI, 0.75-0.96). MRE detected fibrosis of stages 2, 3, or 4 with AUROC values of 0.89 (95% CI, 0.83-0.96), 0.87 (95% CI, 0.78-0.96), and 0.87 (95% CI, 0.71-1.00); TE detected fibrosis of stages 2, 3, or 4 with AUROC values of 0.86 (95% CI, 0.77-0.95), 0.80 (95% CI, 0.67-0.93), and 0.69 (95% CI, 0.45-0.94). MRI-PDFF identified steatosis of grades 2 or 3 with AUROC values of 0.90 (95% CI, 0.82-0.97) and 0.92 (95% CI, 0.84-0.99); CAP identified steatosis of grades 2 or 3 with AUROC values of 0.70 (95% CI, 0.58-0.82) and 0.73 (95% CI, 0.58-0.89). In a prospective, cross-sectional study of more than 100 patients, we found MRE to be more accurate than TE in identification of liver fibrosis (stage 1 or more), using biopsy analysis as the standard. MRI-PDFF is more accurate than CAP in detecting all grades of steatosis in patients with NAFLD.

Role of Shearwave Elastography in the Search of Unknown Primary Cancer in Breast and Abdominopelvis

OBJEVTICES: Shearwave elastography has recently got approval for its use in clinical imaging. It has got its established accuracy in assessing liver fibrosis, where biopsy for the staging of cirrhosis has been minimized. There is emerging data showing its superiority in detecting breast and other cancers as compared to conventional imaging methods. This study aimed to analyse role of shearwave elastography in detection of primary impalpable lesions in breast and abdomino-pelvic regions and those missed on conventional imaging modalities. SETTING: Shearwave Elastography Unit, Liaquat University of Medical & Heath Sciences, Jamshoro, Pakistan DESIGN & METHODS: The study is an observational pilot project including the patients presented to surgery and oncology departments with metastatic cancer suggested on conventional imaging or cytology of the metastatic site but primary sites were not known and suspected to be in the region of breast, abdomen or pelvis. Shearwave elastography was applied as supplementary tool to re-do B-mode ultrasound. Aixplorer Ultrasound System Multiwave version 8.2.0 (Supersonic Imagine S.A., Aix-en-Provence, France) was used in this study. This study selectively includes the patients who were called on experimental basis to see the effectiveness of the system on trial basis, the calculation of the sensitivity, specificity, positive predictive value and negative predictive values were not determined. RESULTS: There were seven patients including four with axillary lymph nodes and three having liver metastases. In patients with axillary lymph nodes mammogram and conventional ultrasound failed to show primary breast lesions, histopathology of the axillary lymph nodes suggested infiltrating ductal carcinoma. In patients with liver metastases conventional ultrasound abdomen and CT scan failed to reveal primary lesions. Shearwave assisted B- mode ultrasound suggested a solid mass in a complex cyst in the kidney in one patient and in the other there were multiple benign cysts and a solid mass however the third patient with liver mass found to have primary from gall bladder. These findings were later confirmed on histopathology or cytology. CONCLUSION: Shearwave elastography is an emerging non invasive technology showing potential role to supplement B-mode ultrasound in detecting unknown primary cancerin breast and abdomino-pelvic region.

Shear-wave elastography in detection of residual breast cancer after neoadjuvant chemotherapy.

102 Background: To evaluate the accuracy of shear-wave elastography (SWE) in detecting residual cancer after neoadjuvant chemotherapy. Methods: This retrospective study was approved by our institutional review board and the requirement for written informed consent was waived. From January 2012 to February 2013, 71 women with stage II-III invasive breast cancers who received neoadjuvant chemotherapy and were imaged with B-mode ultrasonography (US), SWE, and magnetic resonance (MR) imaging before surgery were included. Presence of residual cancer was evaluated and categorized according to the morphology on preoperative B-mode US and MR imaging. Quantitative elasticity values (maximum kPa) were acquired for primary lesions depicted on US. Pathological complete response (pCR) was defined as no residual invasive cancer cells. The quantitative SWE values were compared between the pCR and non-pCR group using independent samples t-test. The areas under the receiver operating characteristics curve (AUC), sensitivities, and specificities of B-mode US, MR, and SWE for detecting residual cancer were compared, with histopathologic examination as the reference standard. Results: Of the 71 women, 15 (21%) achieved pCR. The mean size of residual invasive cancers was 2.2 cm (range 0.1-6.4 cm).The maximum SWE value was significantly higher in the non-pCR group (mean, 122.9 kPa) than in the pCR group (30.6 kPa) (P &lt; 0.001). The AUC of SWE for detecting residual cancer (0.893) was higher than that of B-mode US (0.684) (P = 0.001) and comparable to that of MR (0.884) (P = 0.825). The optimal cut-off value, yielding the maximal sum of sensitivity and specificity, was 98.1 kPa, and the sensitivity and specificity of SWE at that cut-off value were 66% (37 of 56) and 100% (15 of 15). When SWE was added to B-mode US, the AUC value was significantly increased to 0.830 (P = 0.039). Conclusions: SWE was accurate in the detection of residual cancer after neoadjuvant chemotherapy. When SWE was combined with B-mode US, the accuracy was significantly improved.

Characterization of biomechanical properties of agar based tissue mimicking phantoms for ultrasound stiffness imaging techniques

Pathological changes of the body have been observed to change the mechanical properties of soft tissue types which can be imaged by ultrasound elastography. Though initial clinical results using ultrasound elastography in detection of tumors are promising, quantification of signal to noise ratio, resolution and strain image patterns are the best achieved under a controlled study using phantoms with similar biomechanical properties of normal and abnormal tissues. The purpose of this work is to characterize the biomechanical properties of agar based tissue mimicking phantoms by varying the agar concentration from 1.7 to 6.6% by weight and identify the optimum property to be used in classification of cancerous tissues. We performed quasi-static uniaxial compression test under a strain rate of 0.5mm/min up to 15% strain and measured Young's modulus of phantom samples which are from 50kPa to 450kPa. Phantoms show nonlinear stress–strain characteristics at finite strain which were characterized using hyperelastic parameters by fitting Neo-Hookean, Mooney Rivlin, Ogden and Veronda Westmann models. We also investigated viscoelastic parameters of the samples by conducting oscillatory shear rheometry at various precompression levels (2–5%). Loss modulus values are always less than storage modulus which represents the behavior of soft tissues. The increase in agar concentration increases the shear modulus of the samples as well as decreases the linear viscoelastic region. The results suggest that dynamic shear modul are more promising than linear and nonlinear elastic modul in differentiation of various classes of abnormal tissues.

Diagnostic value of EUS elastography in detection of gastrointestinal submucosal tumors

Diagnostic value of EUS elastography in detection of gastrointestinal submucosal tumors

Theoretical Prediction of Ultrasound Elastography for Detection of Early Osteoarthritis

Ultrasound elastography could be used as a new noninvasive technique for detecting early osteoarthritis. As the first critical step, this study theoretically predicted the excitation power and the measurement errors in detecting cartilage detect. A finite element model was used to simulate wave propagation of elastography in the cartilage. The wave was produced by a force F, and the wave speed C was calculated. The normal cartilage model was used to define the relationship between the wave speed and elastic modulus. Various stiffness values were simulated. F = 10 N with a duration of 0.5 ms was required for having measurable deformation (10 μm) at the distal site. The deformation had a significant rise when the wave crossed the defect. The relationship between the wave speed and elastic parameters was found as C = 1.57 × (E)/(2 × ρ(1+μ)))1/2, where E was the elastic modulus, μ was Poisson's ratio, and ρ was the density. For the simulated defect with an elastic modulus of 7 MPa which was slightly stiffer than the normal cartilage, the measurement error was 0.1 MPa. The results suggested that, given the simulated conditions, this new technique could be used to detect the defect in early osteoarthritis.

Metacarpophalangeal (MCP) and Interphalangeal (IP) Joints of the Hand: The Role of Ultrasound and SW Elastography in Detection and Monitoring of Rheumatoid Arthitis (RA)

To display the spectrum of pathologic alterations of MCP and IP joints in RA including gray-scale images, flow assessment and SWE characteristics and establish the role of US in detection and monitoring of the disease. The MCP and the proximal and distal IP joints of the hand were studied in 22 patients with RA in early and advanced stages of the disease, in acute and subacute phases and pre- and post-treatment. The high-resolution US examination comprised gray-scale imaging, flow assessment with colour Doppler in acute and subacute presentation of RA and SWE of the pannus. Different characteristics and a whole spectrum of altering pathology during RA will be shown. An initial estimation of the SWE characteristics of the pannus in acute and subacute stages was made and a statistically significant difference (p < 0.01) was found between the mean values of the two entities. US examination and SWE of the small joints of the hand in patients with rheumatoid arthritis is a quick, cost-effective examination, which is comfortable to the patient and is important in 1. Detecting the early changes, thus monitoring the medical therapy. 2.Follow-up, and 3. guiding interventional procedures.

M1572 AST/ALT, APRI, and Magnetic Resonance Elastography for Detection of Advanced Fibrosis in Clinical Practice

M1572 AST/ALT, APRI, and Magnetic Resonance Elastography for Detection of Advanced Fibrosis in Clinical Practice

Myocardial elastography—a feasibility study in vivo

Early detection of cardiovascular diseases has been a very active research area in the medical imaging field. Assessment of the local and global mechanical functions is one of the major goals of accurate diagnosis. In this study, we investigated the feasibility of elastography for estimation and imaging of the local cardiac muscle displacement and strain in a human heart in vivo. In its noninvasive applications, elastography has been typically used to determine local tissue strain through the use of externally applied compression. For our study, we utilized the cardiac muscle motion during a cardiac cycle as the mechanical stimulus, and acquired successive radiofrequency (RF) data frames of the septal and posterior walls over a few cardiac cycles in parasternal and apical views, respectively. High-quality ciné-loop elastograms were obtained due to high frame rates and the resulting low decorrelation noise. Furthermore, the strain contrast was higher in the parasternal case, when only the posterior wall was imaged, and strain estimation was more robust in the apical view. High repeatability of the results was observed through elastographic measurements over several cardiac cycles. Finally, an M-mode version of elastography was used to follow part of the interventricular septum or the posterior wall over the course of two cardiac cycles. Not only do these preliminary results show that elastography is feasible in cardiac applications in vivo, but also that it can provide new information regarding cardiac motion and mechanical function. Future prospects include assessment of the role of elastography in detection of ischemia and infarction. (E-mail: elisak@bwh.harvard.edu)