Preoperative neoadjuvant chemotherapy in patients with breast cancer evaluated using strain ultrasonic elastography

BACKGROUND The incidence of breast cancer in China is increasing while its mortality rate is decreasing.The annual breast cancer incidence in China is 39.2 million,accounting for two-thirds of the urban population.In China,breast cancer is the fifth most common malignant tumor overall and the most common in women,accounting for 17%of female malignant tumors.AIM To investigate the accuracy of strain ultrasound elastography(SUE)on the evaluation of preoperative neoadjuvant chemotherapy(NAC)in breast cancer.METHODS Overall,90 patients with breast cancer treated at our hospital between January 2018 and February 2019 were selected for this study.The patients received six cycles of NAC with docetaxel,epirubicin,and cyclophosphamide.Surgical treatment was also performed,and pathological reactivity was assessed.The patients were evaluated using conventional ultrasonography and SUE before biopsy.The differences between groups were analyzed to calculate the mean and standard deviation with significance measured using a t-test,while multivariate analysis was performed using logistic regression analysis.RESULTS Of the patients analyzed,20 had a pathological complete remission(pCR)while 70 did not achieve pCR after NAC.The ratio of the elastic strain ratio(SR)and elastic score of 4–5 in patients with pCR were 5.5±1.16 and 15.00%,respectively;these were significantly lower than those in patients without pCR(85%)and significantly higher than in patients without pCR(14%).SR and elastic score 4–5 were independent factors influencing NAC efficacy(OR=0.644,1.426 and 1.366,respectively,P<0.05).SR was positively correlated with elasticity score(rs=0.411,P<0.05).The area under the receiver operator characteristic curve of SR and SR combined with elastic score in predicting patients without pCR was 0.822 and 0.891,respectively(P<0.05).CONCLUSION Strain ultrasonic elastography may be used to evaluate the effects of preoperative NAC in patients with breast cancer.

Applications of endoscopic ultrasound elastography in pancreatic diseases: From literature to real life

Elastography is a non-invasive method widely used to measure the stiffness of the tissues,and it is available in most endoscopic ultrasound machines,using either qualitative or quantitative techniques.Endoscopic ultrasound elastography is a tool that should be applied to obtain a complementary evaluation of pancreatic diseases,together with other imaging tests and clinical data.Elastography can be informative,especially when studying pancreatic masses and help the clinician in the differential diagnosis between benign or malignant lesions.However,further studies are necessary to standardize the method,increase the reproducibility and establish definitive cut-offs to distinguish between benign and malignant pancreatic masses.Moreover,even if promising,elastography still provides little information in the evaluation of benign conditions.

Endogenous motion of liver correlates to the severity of portal hypertension

BACKGROUND Degree of portal hypertension(PH)is the most important prognostic factor for the decompensation of liver cirrhosis and death,therefore adequate care for patients with liver cirrhosis requires timely detection and evaluation of the presence of clinically significant PH(CSPH)and severe PH(SPH).As the most accurate method for the assessment of PH is an invasive direct measurement of hepatic venous pressure gradient(HVPG),the search for non-invasive methods to diagnose these conditions is actively ongoing.AIM To evaluate the feasibility of parameters of endogenously induced displacements and strain of liver to assess degree of PH.METHODS Of 36 patients with liver cirrhosis and measured HVPG were included in the casecontrol study.Endogenous motion of the liver was characterized by derived parameters of region average tissue displacement signal(dantero,dretro,dRMS)and results of endogenous tissue strain imaging using specific radiofrequency signal processing algorithm.Average endogenous strainμand standard deviationσof strain were assessed in the regions of interest(ROI)(1 cm×1 cm and 2 cm×2 cm in size)and different frequency subbands of endogenous motion(0-10 Hz and 10-20 Hz).RESULTS Four parameters showed statistically significant(P<0.05)correlation with HVPG measurement.The strongest correlation was obtained for the standard deviation of strain(estimated at 0-10 Hz and 2 cm×2 cm ROI size).Three parameters showed statistically significant differences between patient groups with CSPH,but only dretro showed significant results in SPH analysis.According to ROC analysis area under the curve(AUC)of theσROI[0…10Hz,2 cm×2 cm]parameter reached 0.71(P=0.036)for the diagnosis of CSPH;with a cut-off value of 1.28μm/cm providing 73%sensitivity and 70%specificity.AUC for the diagnosis of CSPH forμROI[0…10Hz,1 cm×1 cm]was 0.78(P=0.0024);with a cut-off value of 3.92μm/cm providing 73%sensitivity and 80%specificity.Dretro parameter had an AUC of 0.86(P=0.0001)for the diagnosis of CSPH and 0.84(P=0.0001)for the diagnosis of SPH.A cut-off value of-132.34μm yielded 100%sensitivity for both conditions,whereas specificity was 80%and 72%for CSPH and SPH respectively.CONCLUSION The parameters of endogenously induced displacements and strain of the liver correlated with HVPG and might be used for non-invasive diagnosis of PH.

Sonographic evaluation of prostatic artery embolization:Far beyond size measurements

Prostatic artery embolization(PAE)has gained acceptance as a minimally invasive,safe and effective treatment of symptomatic benign prostatic hyperplasia.Radiologic imaging is an indispensable part of post-interventional evaluation of PAE and serves both clinical and investigational purposes.In this context,ultrasonography(US)has a central and multifaceted role.Gray-scale US is routinely utilized for measurement of significant outcome parameters(prostatic volume,intra-vesical prostatic protrusion and post-void residual volume)before and after PAE.Improvement of these parameters may become more obvious onemonth post-PAE,or later.Contrast-enhanced US(CEUS)with intravenous administration of a second-generation echo-enhancer can demonstrate prostatic infarcts(as enhancement defects)immediately post-PAE and monitor their resolution over time.The volume of prostatic infarcts can also be measured and compared to prostatic volume.Prostatic infarction is a definite sign of the local efficacy of PAE and a predictor of prostate shrinkage and(at least in some patients)of clinical success.CEUS can also be performed intraoperatively in the angio-suite,for on-site evaluation of the ischemic effect;a variation of this technique,with intraarterial(instead of intravenous)administration of diluted echo enhancer,can also be applied intraoperatively,to map the embolized territory and to prevent non-target embolization.Initial experience with USelastographic techniques(shear-wave and strain elastography)has shown that they can detect and quantify the improvement of tissue elasticity post-PAE,thus providing new insights into the therapeutic mechanisms of this treatment.With utilization of high-end equipment,experience and standardized imaging protocols,US could be the primary modality for imaging evaluation of PAE.

Elastogram:Physics,Clinical Applications,and Risks

The tissue stiffness is always an interesting issue to clinicians.Traditionally,it is assessed by the manual palpation,and this now can be measured by the ultrasound-based elastography.The basic physics is based on Young's modulus through the Hooke's law:E=S/e,where the Young's modulus(E)equals to the stress applied to the object(S)divided by the generated strain(e).With the rapid advancement of technology,the elastography has evolved from quasi-static elastography(ie,strain elastography)to dynamic elastography(i,e,shear wave elastography).The key differentiation of these two categories roots in the stimuli applied,namely mechanical or acoustic radiation force,and the response of the soft tissue.The strain elastography requires the operator to compress and decompress the tissue manually and the motion of the tissue during the stimuli is tracked to calculate the strain to reflect the tissue stiffness.While strain elastography is operator-dependent,shear wave elastography is not.Using shear wave elastography,the tissue is stimulated by the acoustic radiation force which can generate shear wave traveling through the tissue transversely.The shear wave propagation speed(Vs)is related to the shear modulus(μ)of the medium:μ=pVs^(2),where p is the density of the tissue and assumed to be a constant as 1000 kg/m^(3).In the incompressible biological tissue,the Young's modulus is approximately three times the shear modulus(E≈3μ).So the quantitative measurements of the tissue stiffness can be attained by shear wave elastography.The clinical application of elastography and its diagnostic capability has been extended.The knowledge of the basic physics of the various type of elastography facilitates the effective use of elastography.This review presented the clinical application and the risks of different types of elastography.