Comparison of US elastography and chemical shift magnetic resonance imaging in multifidus muscle fatty degeneration.

OBJECTIVE: The purpose of this study was to investigate the feasibility of the use of shear wave elastography (SWE) in comparison to chemical shift encoding (CSE) magnetic resonance imaging (MRI) for the evaluation of multifidus muscle fatty degeneration in patients with chronic low back pain. METHOD: Multifidus muscles were evaluated with the CSE-MRI and SWE examinations in control and patient groups. With the in-phase and out-phase sequences in CSE-MRI, signal intensity index (SII), and signal intensity suppression ratio (SISR) values; with the SWE method, shear wave velocity values were determined. Differences in the mean values of these parameters per level and study group were analyzed by Student's t-test. RESULTS: SWE revealed significantly lower stiffness at the L2-3 level, consistent with the signal index values (SII-SISR) showing increased fatty infiltration on MRI in the patient group. No such relationship was found at the L4-5 level or in control group. CONCLUSIONS: SWE may be a promising method to show muscle fatty infiltration at L2-3 level in patients with chronic low back pain.

OBJETIVO: Investigar la viabilidad del uso de la elastografía de ondas de corte en comparación con la resonancia magnética con codificación de desplazamiento químico (RM-CDQ) para la evaluación de la degeneración grasa del músculo multífido en pacientes con dolor lumbar crónico. MÉTODO: Los músculos multífidos se evaluaron con RM-CDQ y elastografía de ondas de corte en los grupos de control y de pacientes. Se consideraron las secuencias en fase y fuera de fase en RM-CDQ, y los valores del índice de intensidad de señal y del índice de supresión de intensidad de señal; con el método de elastografía de ondas de corte se determinaron los valores de velocidad de onda de corte. Las diferencias en los valores medios de estos parámetros por nivel y por grupo de estudio se analizaron mediante la prueba t de Student. RESULTADOS: La elastografía de ondas de corte reveló una rigidez significativamente menor en el nivel L2-3, consistente con los valores de los índices de señal que muestran una mayor infiltración grasa en la RM en el grupo de pacientes. No se encontró tal relación en el nivel L4-5 ni en el grupo de control. CONCLUSIONES: La elastografía de ondas de corte puede ser un método prometedor para mostrar la infiltración grasa muscular a nivel L2-3 en pacientes con dolor lumbar crónico.

Asociación de fibrosis hepática mediante elastografía por shear wave 2D y score APRI

Introducción: Las hepatopatías son un problema prevalente a nivel mundial. La biopsia hepática ha sido hasta la fecha el gold standard para valorar el grado de fibrosis, sin embargo, con el advenimiento de nuevos métodos no invasivos, costo-efectivos para el sistema sanitario, cada vez recurrimos menos a esta. En nuestro medio se introdujo recientemente la elastografía por onda cizallamiento con imagen biplanar, lo que implica una curva de aprendizaje por parte de los técnicos. Objetivo: Valorar la asociación de los grados de fibrosis hepática determinado por la elastografía por onda de cizallamiento con imagen biplanar (2D-SWE) y el score APRI en pacientes portadores de enfermedad hepática asistidos en el servicio de hepatología del Hospital Pasteur.Médica 2. Metodología: Se incluyeron los pacientes con enfermedad hepática de cualquier etiología, asistidos entre el 01/10/21 al 31/08/22, mayores de 15 años, de ambos sexos y que han sido valorados con elastografía por onda de cizallamiento con imagen biplanar (2D-SWE) y analítica sanguínea realizado por el equipo médico del servicio mencionado en los últimos 6 meses. Resultados: Se incluyeron 158 pacientes. Se encontró mayor prevalencia de enfermedad hepática en mujeres, con predominio de la etiología de enfermedad por hígado graso no alcohólico (EHGNA) e infección por virus de hepatitis C (VHC). Se evidenció asociación positiva entre la elastografía (2D-SWE) y el score APRI para el diagnóstico o exclusión de enfermedad hepática avanzada, sin diferencia estadísticamente significativa entre los dos médicos hepatólogos. Conclusiones: Existe asociación entre la elastografía por SWE y el score APRI para el diagnóstico de enfermedad hepática avanzada en la población general y por etiología.

Introduction: Liver diseases are a prevalent problem worldwide. To date, liver biopsy has been the gold standard for assessing the degree of fibrosis; however, with the advent of new non-invasive, cost-effective methods for the healthcare system, we are resorting to it less and less. Shear wave elastography with biplanar imaging was recently introduced in our setting, which implies a learning curve for technicians. Objective: To assess the association of the degrees of liver fibrosis determined by shear wave elastography with biplanar imaging (2D-SWE) and the APRI score in patients with liver disease treated in the hepatology service of the Pasteur Hospital. Methodology: Patients with liver disease of any etiology, attended between 01/10/21 and 08/31/22, over 15 years of age, of both sexes and who have been evaluated with shear wave elastography with biplanar image were included. (2D-SWE) and blood analysis performed by the medical team of the aforementioned service in the last 6 months. Results: 158 patients were included. A higher prevalence of liver disease was found in women, with a predominance of the etiology of nonalcoholic fatty liver disease (NAFLD) and hepatitis C virus (HCV) infection. A positive association was evident between elastography (2D-SWE) and the APRI score for the diagnosis or exclusion of advanced liver disease, with no statistically significant difference between the two hepatologists. Conclusions: There is an association between SWE elastography and the APRI score for the diagnosis of advanced liver disease in the general population and by etiology.

Introdução: As doenças hepáticas são um problema prevalente em todo o mundo. Até o momento, a biópsia hepática tem sido o padrão ouro para avaliar o grau de fibrose, porém, com o advento de novos métodos não invasivos e de baixo custo para o sistema de saúde, recorremos cada vez menos a ela. A elastografia por onda de cisalhamento com imagem biplanar foi introduzida recentemente em nosso meio, o que implica uma curva de aprendizado para os técnicos. Objetivo: Avaliar a associação dos graus de fibrose hepática determinados pela elastografia por ondas de cisalhamento com imagem biplanar (2D-SWE) e o escore APRI em pacientes com hepatopatia atendidos no serviço de hepatologia do Hospital Pasteur. Metodologia: Foram incluídos pacientes portadores de doença hepática de qualquer etiologia, atendidos entre 10/01/21 e 31/08/22, maiores de 15 anos, de ambos os sexos e que foram avaliados com elastografia por onda de cisalhamento com imagem biplanar. ( 2D-SWE) e análises sanguíneas realizadas pela equipa médica do referido serviço nos últimos 6 meses. Resultados: foram incluídos 158 pacientes. Foi encontrada maior prevalência de doença hepática em mulheres, com predomínio da etiologia da doença hepática gordurosa não alcoólica (DHGNA) e da infecção pelo vírus da hepatite C (HCV). Foi evidente uma associação positiva entre a elastografia (2D-SWE) e o escore APRI para o diagnóstico ou exclusão de doença hepática avançada, sem diferença estatisticamente significativa entre os dois hepatologistas. Conclusões: Existe associação entre a elastografia SWE e o escore APRI para o diagnóstico de doença hepática avançada na população geral e por etiologia.

Correlation between the shear modulus measured by elastography (SSI) and tangent modulus from tensile tests of in vitro fresh-frozen human tendons.

Assessing the mechanical properties of tendons in vivo allows for quantifying the degree of pathology and tracking functional improvements. The Supersonic Shearwave Imaging (SSI) technique is a state-of-the-art method for analyzing musculoskeletal tissues in vivo. This technique estimates tissue stiffness as the shear elastic modulus µ [kPa]. However, only a few studies have validated the accuracy of SSI-estimated shear modulus against the gold standard for in vitro material testing, the tensile test. This study compared the SSI-measured shear elastic modulus (µ) with the tangent modulus (Etan) obtained from mechanical tensile tests for human Achilles (AT) and patellar tendons (PT). The sample comprised eleven fresh-frozen human Achilles tendons and five fresh-frozen human patellar tendons from cadavers that were not degraded by formalin or ionizing radiation. The tendons were tested in a tensile machine, and elastography videos were collected and segmented every 5% of the total experiment time. The absolute µ values estimated from both instruments presented an up to 20-fold difference. However, a strong significant positive correlation was found between µ and Etan for both tendons (range AT: R = 0.9765-0.9972 and PT: R = 0.8719-0.9782). The two resulting curves (µ and Etan) as a function of strain (ε) were normalized by their maxima for visually comparing stiffness × strain profiles. In conclusion, despite the inaccurate absolute values, SSI has been shown to measure relative changes in human Achilles and patellar tendon stiffness. This study endorses future clinical use of SSI to provide in vivo estimations of human tendons' mechanical properties.

Ultrasound Elastography for the Diagnosis of Endometriosis and Adenomyosis: A Systematic Review with Meta-analysis.

Elastography is capable of measuring tissue mechanical properties and elasticity. It is used to help diagnose various diseases, although its use in pelvic endometriosis remains to be established. A systematic review and meta-analysis were conducted to assess transvaginal ultrasound elastography for the diagnosis of different manifestations of endometriosis and adenomyosis. PRISMA guidelines were used for a Medline, PubMed, Embase, BVS/Bireme, Scopus, Cochrane Library and Escudos database search. Studies indexed until March 2021 that evaluated elastography compared with histopathological results (gold standard), ultrasound or magnetic resonance imaging for diagnosis of pelvic endometriosis and adenomyosis were eligible. The Rayyan platform was used to select studies. Sensitivity (S), specificity (Ps), positive and negative predictive values and receiver operating characteristic curves were calculated for elastographic diagnosis of endometriosis. A meta-analysis using Review Manager 5 and Open Meta Analyst was performed. Bias risk in the studies was analyzed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. This systematic review was prospectively registered in the PROSPERO database: CRD42021244555. Among the 163 identified citations, 10 studies were eligible for review (5 for diagnosis of adenomyosis, 2 for endometrioma, 3 for deep intestinal endometriosis and rectovaginal septum [deep pelvic endometriosis], N = 744 women). In deep pelvic endometriosis, lesions diagnosed by elastography were found to correlate with histopathology results. Increased "stiffness" (elastography) was associated with a higher fibrotic component, with S = 78%-100% and Ps = 100%, according to the authors. On elastography, endometriomas were stiffer than hemorrhagic cysts (S = 82%, Ps = 79%) and malignant tumors (S = 86%, Ps = 100%). For these lesions, a meta-analysis could not be performed because the small number of studies and insufficient data. In adenomyosis, meta-analysis and receiver operating characteristic curve analysis revealed that elastography had good sensitivity and specificity. Studies indicated a low bias risk by QUADAS-2. Elastography had high sensitivity and specificity for deep pelvic endometriosis diagnosis, and its findings correlated with histopathology results. For adenomyosis, the meta-analysis confirmed the sensitivity and specificity results of the studies. Given these results, elastography may be a promising imaging test, contributing to non-invasive diagnosis of endometriosis and adenomyosis.

Shear wave elastography of the brachioradialis spastic muscle and its correlations with biceps brachialis and clinical scales.

BACKGROUND: Shear wave elastography technique estimates biological tissue shear elastic modulus (µ[kPa]), which can be used as an objective, muscle-specific indicator of stiffness increase caused by spasticity. We measured both the brachioradialis and biceps brachialis µ in hemiparetic post-stroke patients (n = 11). The spastic arm was compared with the supposedly non-affected contralateral limb and correlated with Fugl-Meyer Assessment and Modified Ashworth Scales. METHODS: Shear elastic modulus was estimated using an Aixplorer V.9 ultrasound device with the elbow at full extension. Average shear elastic modulus t-test, effect sizes, correlation matrix, spider plots and factor analysis were used to check for differences between spastic and nonspastic sides and explore relationships among the variables. FINDINGS: Spastic brachioradialis µ (22.54 ± 11.59 kPa) and biceps brachialis (26.86 ± 12.07 kPa) were significantly greater than the non-spastic counterparts (13.13 ± 2.81 kPa, p = 0.031, ηp2 = 0.3846 for brachioradialis and 15.25 ± 5.00 kPa, p = 0.007, ηp2 = 0.5345 for biceps brachialis). Significant correlations were observed between the spastic brachioradialis and biceps µ and Modified Ashworth Scales, but no correlation with Fugl-Meyer Assessment. INTERPRETATION: Elastography can provide muscle-specific shear elastic modulus estimations of spastic brachioradialis and biceps brachialis, which are distinct from the nonspastic side. In some patients, there was no clear correspondence of the Fugl-Meyer Assessment functional scale with Modified Ashworth Scales and µ, suggesting that spasticity is not the only determinant of arm function. Additionally, shear wave elastography of brachioradialis and biceps brachialis muscles may guide the spasticity treatment, for instance, selecting the preferable candidate for botulinum toxin therapy.

A retrospective study of reducing unnecessary thyroid biopsy for American College of Radiology Thyroid Imaging Reporting and Data Systems 4 assessment through applying shear wave elastography

ABSTRACT Objective The purpose of the study is to quantitatively assess shear-wave elastography (SWE) value in American College of Radiology Thyroid Imaging Reporting and Data Systems (ACR TI-RADS) 4. Materials and methods One hundred and fifty-two ACR TI-RADS 4 thyroid nodules undergoing SWE were included in the study. The mean (EMean), minimum (EMin) and maximum (EMax) of SWE elasticity were measured. Results The areas under the receiver operating characteristic (ROC) curves for SWE EMean, EMin and EMax in detecting benign and malignant nodules were 0.95, 0.83 and 0.84, respectively. Cut-off value of EMean ≤ 23.30 kPa is able to downgrade the lesion category to ACR TI-RADS 3 and cut-off value of EMean ≥ 52.14 kPa is able to upgrade the lesion category to ACR TI-RADS 5. Conclusions The EMean of SWE will probably identify nodules that have a high potential for benignity in ACR TI-RADS 4. It may help identify and select benign nodules while reducing unnecessary biopsy of benign thyroid nodules.

Diagnostic Accuracy Evaluation of Two-Dimensional Shear Wave Elastography in the Differentiation Between Benign and Malignant Thyroid Nodules: Systematic Review and Meta-analysis.

OBJECTIVES: To evaluate two-dimensional (2D) shear wave elastography (SWE) performance as an independent predictor of malignancy in the diagnostic differentiation of thyroid nodules (TNs), including subgroup analyses of different manufacturers and respective cutoffs points. METHODS: The online databases MEDLINE (PubMed), Embase, and the Cochrane Library were searched for articles using 2D SWE in TN evaluation. After good-quality relevant thyroid-specific articles were selected, the main data, plus their sensitivity and specificity, were tabulated. Summary receiver operating characteristic curves were generated to verify the accuracy of data obtained from 3 manufactures. A meta-analysis was performed to evaluate whether clinical recommendations can be improved by the use of 2D SWE to differentiate TNs. RESULTS: The sensitivity and specificity parameters of 2D SWE for the differentiation between benign and malignant TNs according to different instruments were, respectively, as follows: Toshiba SWE (Toshiba Medical Systems, Tochigi, Japan), 0.77 (95% confidence interval [CI], 0.70-0.83) and 0.76 (95% CI, 0.72-0.81); Virtual Touch tissue imaging and quantification (Siemens Medical Solutions, Mountain View, CA), 0.72 (95% CI, 0.67-0.77) and 0.81 (95% CI, 0.78-0.84); and SuperSonic SWE (SuperSonic Imagine, Aix-en-Provence, France), 0.63 (95% CI, 0.59-0.66) and 0.81 (95% CI, 0.79-0.83). The summary receiver operating characteristic curves showed the following area under the curve syntheses: Toshiba SWE, 0.84 (Q* = 0.7707); Virtual Touch tissue imaging and quantification, 0.85 (Q* = 0.7809); and SuperSonic SWE, 0.88 (Q* = 0.8102). Positive and negative predictive values varied, respectively, from 16% to 94% and 29% to 100%, considering all included articles. The overall accuracy ranged from 53% to 93%. CONCLUSIONS: Two-dimensional SWE is a relevant and an important tool that supports ultrasound in clinical practice in the diagnostic differentiation between benign and malignant TNs.

Bidimensional shear-wave elastography for assessing liver fibrosis in children: a proposal of reference values that correlate with the histopathological Knodell-Ishak score.

BACKGROUND: A limited number of publications correlate bidimensional shear-wave elastography (2-D SWE) and stages of liver fibrosis in children. OBJECTIVE: To correlate liver elastography values using 2-D SWE and liver biopsy classified by Knodell-Ishak score to evaluate fibrosis in pediatric patients with liver disease, and to propose values of 2-D SWE (kPa) correlating with Knodell-Ishak score, which have not been defined in the literature. MATERIALS AND METHODS: We conducted a prospective cross-sectional observational study on the performance of diagnostic tests. Between June 2016 and June 2018, elastography was performed in 213 children and young adults who had undergone liver biopsy. B mode, Doppler and 2-D SWE were performed using an Aixplorer (SuperSonic Imagine, Aix-en-Provence, France). Histology samples were classified using the Knodell-Ishak score. We evaluated performance by assessing sensitivity, specificity, positive predictive value and negative predictive value. To determine cut-off points for the continuous variables, we used receiver operating characteristic (ROC) curves. All the cutoff values we established apply only to the SuperSonic Aixplorer system. RESULTS: Measurement with 2-D SWE was successful, with a good correlation with fibrosis stage. The area under the curve (AUC) to differentiate between early (Stages 1-2) and moderate (Stages 3-4) fibrosis was 0.91 (95% confidence interval [CI]: 0.87-0.96), with a sensitivity of 92% and specificity of 86%, with a cutoff value 12 kPa (2 m/s). The AUC of severe fibrosis (early stages of cirrhosis; Stage 5) was 0.95 (95% CI: 0.92-0.97), with a sensitivity of 94% and specificity of 90%, with a cutoff value 18.5 kPa (2.48 m/s). In two patients with hematopoietic stem cell transplantation and suspicion of graft versus host disease we found high 2-D SWE values in correlation with the fibrosis stages (Stage 0 with a median of 13 kPa [2.08 m/s] with hemosiderosis Grade 2 in one child and Stage 2 with a median of 46 kPa [3.91 m/s] and hemosiderosis Grade 4 in the other). CONCLUSION: Our study shows the usefulness and accuracy of 2-D SWE for detecting liver fibrosis in pediatric patients. We propose reference values for Knodell-Ishak Stages 1 and 5. We found hemosiderosis as a possible confounding factor that hasn't been described with 2-D SWE.

The effect of regions-of-interest and elasticity modulus selection on differentiating benign and malignant cervical lymph nodes with shear wave elastography

OBJECTIVE: Imaging diagnosis of cervical lymphadenopathy has conventionally used ultrasonography. Shear wave elastography (SWE) is a recent ultrasound technological advancement that has shown promise in the important medical problem of differentiating between benign and malignant cervical lymph nodes based on quantitative measurements of elasticity modulus. However, widely varying elasticity modulus metrics and regions-of-interest (ROIs) were used in existing studies, leading to inconsistent findings and results that are hard to compare with each other. METHODS: Using a large dataset of 264 cervical lymph nodes from 200 patients, we designed a study comparing three elasticity modulus metrics (Emax, Emean, and standard deviation-SD) with three different ROIs to evaluate the effect of such selections. The metric values were compared between the benign and malignant node groups. The different ROI and metric selections were also compared through receiver operating characteristics curve analysis. RESULTS: For all ROIs, all metric values were significantly different between the two groups, indicting their diagnostic potential. This was confirmed by the ≥0.80 area under the curve (AUC) values achieved with these metrics. Different ROIs had no effect on Emax, whereas all ROIs achieved high performance at 0.88 AUC. For Emean, the smallest ROI focusing on the area of the highest elasticity achieved the best diagnostic performance. In contrast, the larger ROIs achieved higher performances for SD. CONCLUSIONS: This study illustrated the effect of elasticity modulus and ROI selection on the diagnostic performance of SWE on cervical lymphadenopathy. These new findings help guide relevant future studies and clinical applications of this important quantitative imaging modality.

Ultrasound elastography in the evaluation of thyroid nodules: evolution of a promising diagnostic tool for predicting the risk of malignancy.

The elastic properties of tissue have always been of interest in clinical practice. In the past, the identification of structures that were stiffer on physical palpation would raise the suspicion that "there was something wrong". With the development and advancement of medicine, there proved to be a true correlation in the prediction of malignancy of a lesion: malignant disease tends to stiffen the affected tissue, either by increased cell proliferation or fibrosis. Palpation is the oldest method for the detection of thyroid nodules, which is informed by the knowledge that malignant thyroid lesions tend to be much harder than benign ones. Unfortunately, palpation is a highly subjective method that is dependent on the size and location of the lesion, as well as on the skill of the physician. In cases where these nodules are very small or are located in deep regions, their detection by palpation is difficult or even impossible. In addition, although a malignant lesion differs in terms of elasticity, it may not have echogenic properties, preventing its detection by conventional ultrasound. Imaging that indicates the stiffness or deformation of tissues, through the use of ultrasound elastography techniques, adds new information related to their structural formation. In this article, we review the basic physical principles of elastography and the evolution of the method for the evaluation of thyroid nodules, as well as the limitations of and future perspectives for its use.

A propriedade elástica dos tecidos sempre foi motivo de interesse na prática clínica. A palpação física de estruturas mais rígidas levantava a suspeita de que "havia algo estranho" e isso se mostrou, com o desenvolvimento e avanços da medicina, uma correlação verdadeira na predição de malignidade de uma lesão: a doença maligna tende a enrijecer o tecido acometido, quer por proliferação celular aumentada ou por fibrose. A palpação é o método mais antigo para a detecção de nódulos tireoidianos. Lesões tireoidianas malignas tendem a ser muito mais duras do que as benignas. Infelizmente, a palpação é um método altamente subjetivo e depende do tamanho e localização da lesão e da habilidade do médico. Nos casos em que esses nódulos são muito pequenos ou estão localizados em regiões profundas, a sua detecção por palpação é dificultada ou até mesmo impossível. Além disso, mesmo sendo elasticamente diferente, a lesão pode não apresentar propriedades ecogênicas, impedindo a sua detecção por ultrassonografia convencional. A imagem da rigidez ou deformação desses tecidos acrescenta novas informações relacionadas à sua formação estrutural por meio das técnicas de elastografia. Revisamos, neste artigo, os princípios físicos básicos e a evolução da elastografia para avaliação de nódulos tireoidianos, bem como as limitações e perspectivas futuras do uso dessa técnica.

Ultrasound elastography in the evaluation of thyroid nodules: evolution of a promising diagnostic tool for predicting the risk of malignancy / Sonoelastografia na avaliação de nódulos tireoidianos: evolução do método como uma ferramenta diagnóstica promissora na predição de risco de malignidade

Abstract The elastic properties of tissue have always been of interest in clinical practice. In the past, the identification of structures that were stiffer on physical palpation would raise the suspicion that "there was something wrong". With the development and advancement of medicine, there proved to be a true correlation in the prediction of malignancy of a lesion: malignant disease tends to stiffen the affected tissue, either by increased cell proliferation or fibrosis. Palpation is the oldest method for the detection of thyroid nodules, which is informed by the knowledge that malignant thyroid lesions tend to be much harder than benign ones. Unfortunately, palpation is a highly subjective method that is dependent on the size and location of the lesion, as well as on the skill of the physician. In cases where these nodules are very small or are located in deep regions, their detection by palpation is difficult or even impossible. In addition, although a malignant lesion differs in terms of elasticity, it may not have echogenic properties, preventing its detection by conventional ultrasound. Imaging that indicates the stiffness or deformation of tissues, through the use of ultrasound elastography techniques, adds new information related to their structural formation. In this article, we review the basic physical principles of elastography and the evolution of the method for the evaluation of thyroid nodules, as well as the limitations of and future perspectives for its use.

Resumo A propriedade elástica dos tecidos sempre foi motivo de interesse na prática clínica. A palpação física de estruturas mais rígidas levantava a suspeita de que "havia algo estranho" e isso se mostrou, com o desenvolvimento e avanços da medicina, uma correlação verdadeira na predição de malignidade de uma lesão: a doença maligna tende a enrijecer o tecido acometido, quer por proliferação celular aumentada ou por fibrose. A palpação é o método mais antigo para a detecção de nódulos tireoidianos. Lesões tireoidianas malignas tendem a ser muito mais duras do que as benignas. Infelizmente, a palpação é um método altamente subjetivo e depende do tamanho e localização da lesão e da habilidade do médico. Nos casos em que esses nódulos são muito pequenos ou estão localizados em regiões profundas, a sua detecção por palpação é dificultada ou até mesmo impossível. Além disso, mesmo sendo elasticamente diferente, a lesão pode não apresentar propriedades ecogênicas, impedindo a sua detecção por ultrassonografia convencional. A imagem da rigidez ou deformação desses tecidos acrescenta novas informações relacionadas à sua formação estrutural por meio das técnicas de elastografia. Revisamos, neste artigo, os princípios físicos básicos e a evolução da elastografia para avaliação de nódulos tireoidianos, bem como as limitações e perspectivas futuras do uso dessa técnica.

Diagnostic accuracy of shear wave elastography - Virtual touch™ imaging quantification in the evaluation of breast masses: Impact on ultrasonography's specificity and its ultimate clinical benefit.

OBJECTIVES: To evaluate the diagnostic performance and the clinical benefit of Shear-Wave Elastography - Virtual Touch™ Imaging Quantification (SWE-VTIQ) as a complement to ultrasonography (US). METHODS: From October 2016 through Jun 2017, B-mode US and SWE-VTIQ were prospectively performed in 396 breast masses in 357 women who consented to undergo this study. Quantitative elastography values were recorded: Vmax (maximum elasticity), Vmean (median elasticity), Vratio(max) (ratio of Vmax and surrounding parenchyma) and Vratio(mean) (ratio of Vmean and surrounding parenchyma). The histopathology of the lesions was considered the reference standard for benign or malignant definition. The performance of the four elastographic parameters was evaluated trough sensitivity, specificity and AUC. The parameter with the best performance was tested in six different diagnostic approaches defined based on clinical practice. RESULTS: Of the 396 masses, 122 (30.8%) were benign and 274 (69.2%) were malignant. All SWE parameters were significantly higher in malignant masses (all p < 0.01). Vmax and Vratio(max) performed significantly better then Vratio(mean) (p = 0.01 and p = 0.03, respectively). SWE-VTIQ improved US specificity in all diagnostic approaches, except when applied to BI-RADS 3 lesions. SWE-VTIQ reduced the false positive rate in 25% if applied only to BI-RADS 4A masses, maintaining a high sensitivity (98.9%, 95% confidence interval 97.1-100%) and a negative predictive value of 95.5%. When applied to BI-RADS 4A and 4B masses, SWE-VTIQ reduced the false positive rate in 54.4%. However, 13 malignant cases would be missed in this approach (4.7% of all malignant cases). CONCLUSIONS: SWE-VTIQ increases US specificity when applied to BI-RADS 4 A lesions, significantly reducing unnecessary interventions and preserving the diagnosis of malignant lesions. When applied also to BI-RADS® 4B lesions, SWE-VTIQ increases the number of false negative cases, which should be evaluated with caution.

Ultrasound Elastography to Quantify Liver Disease Severity in Autosomal Recessive Polycystic Kidney Disease.

OBJECTIVES: To evaluate the diagnostic accuracy of ultrasound elastography with acoustic radiation force impulse (ARFI) to detect congenital hepatic fibrosis and portal hypertension in children with autosomal recessive polycystic kidney disease (ARPKD). STUDY DESIGN: Cross-sectional study of 25 children with ARPKD and 24 healthy controls. Ultrasound ARFI elastography (Acuson S3000, Siemens Medical Solutions USA, Inc, Malvern, Pennsylvania) was performed to measure shear wave speed (SWS) in the right and left liver lobes and the spleen. Liver and spleen SWS were compared in controls vs ARPKD, and ARPKD without vs with portal hypertension. Linear correlations between liver and spleen SWS, spleen length, and platelet counts were analyzed. Receiver operating characteristic analysis was used to evaluate diagnostic accuracy of ultrasound ARFI elastography. RESULTS: Participants with ARPKD had significantly higher median liver and spleen SWS than controls. At a proposed SWS cut-off value of 1.56 m/s, the left liver lobe had the highest sensitivity (92%) and specificity (96%) for distinguishing participants with ARPKD from controls (receiver operating characteristic area 0.92; 95% CI 0.82-1.00). Participants with ARPKD with portal hypertension (splenomegaly and low platelet counts) had significantly higher median liver and spleen stiffness than those without portal hypertension. The left liver lobe also had the highest sensitivity and specificity for distinguishing subjects with ARPKD with portal hypertension. CONCLUSIONS: Ultrasound ARFI elastography of the liver and spleen, particularly of the left liver lobe, is a useful noninvasive biomarker to detect and quantify liver fibrosis and portal hypertension in children with ARPKD.