***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: AIM To investigate the feasibility and reproducibility of real-time freeh and ultrasound elastography ( RTE ) of the normal Achilles tendon and to describe its elastographic appearances . MATERIAL S AND METHODS Fifty normal Achilles tendons were prospect ively examined using RTE performed by tissue compression using the h and -held transducer . The information was colour-coded ( red = soft , green = medium , blue = hard ) and superimposed on the B-mode image . Each tendon was examined three times transversely and longitudinally by two radiologists and the ratio between tendon and retro-Achilles fat strain ( strain index ) was calculated . The reproducibility of the elastograms was assessed qualitatively and quantitatively using the strain index inter and intra observer variation coefficient ( intra/inter-CV and intra/inter-CC , respectively ) . RESULTS All tendons were clearly visualized on the elastograms . Nineteen tendons ( 19/50 , 38 % ) appeared homogeneously green/blue ( type 1 ) . Thirty-one tendons ( 31/50 , 62 % ) appeared green with longitudinal red stripes ( type 2 ) . The intra- and inter-CC values of the strain index were lower for the transverse plane than for the longitudinal plane ( 0.43 , 0.45 , 0.41 and 0.78 , 0.66 , 0.51 , respectively ) . The intra-CV and inter-CV values were higher for the transverse than for the longitudinal plane measurements ( 39 % , 37 % , 30 % and 30.50 % , 30.10 % , 29.60 % , respectively ) . CONCLUSION RTE of the normal Achilles tendon is a feasible method . The reproducibility of the strain index is good and higher for longitudinal elastograms . Qualitative assessment enables the discrimination of two distinct elastographic patterns . Further studies are required to assess the clinical value of this method PURPOSE To investigate the differences in viscoelastic properties between normal and pathologic Achilles tendons ( ATs ) by using real-time shear-wave elastography ( SWE ) . MATERIAL S AND METHODS The institutional review board approved this study , and written informed consent was obtained from 25 symptomatic patients and 80 volunteers . One hundred eighty ultrasonographic ( US ) and SWE studies of ATs without tendonopathy and 30 studies of the middle portion of the AT in patients with tendonopathy were assessed prospect ively . Each study included data sets acquired at B-mode US ( tendon morphology and cross-sectional area ) and SWE ( axial and sagittal mean velocity and relative anisotropic coefficient ) for two passively mobilized ankle positions . The presence of AT tears at B-mode US and signal-void areas at SWE were noted . RESULTS Significantly lower mean velocity was shown in tendons with tendonopathy than in normal tendons in the relaxed position at axial SWE ( P < .001 ) and in the stretched position at sagittal ( P < .001 ) and axial ( P = .0026 ) SWE . Tendon softening was a sign of tendonopathy in relaxed ATs when the mean velocity was less than or equal to 4.06 m · sec(-1 ) at axial SWE ( sensitivity , 54.2 % ; 95 % confidence interval [ CI ] : 32.8 , 74.4 ; specificity , 91.5 % ; 95 % CI : 86.3 , 95.1 ) and less than or equal to 5.70 m · sec(-1 ) at sagittal SWE ( sensitivity , 41.7 % ; 95 % CI : 22.1 , 63.3 ; specificity , 81.8 % ; 95 % CI : 75.3 , 87.2 ) and in stretched ATs , when the mean velocity was less than or equal to 4.86 m · sec(-1 ) at axial SWE ( sensitivity , 66.7 % ; 95 % CI : 44.7 , 84.3 ; specificity , 75.6 % ; 95 % CI : 68.5 , 81.7 ) and less than or equal to 14.58 m · sec(-1 ) at sagittal SWE ( sensitivity , 58.3 % ; 95 % CI : 36.7 , 77.9 ; specificity , 83.5 % ; 95 % CI : 77.2 , 88.7 ) . Anisotropic results were not significantly different between normal and pathologic ATs . Six of six ( 100 % ) partial-thickness tears appeared as signal-void areas at SWE . CONCLUSION Whether the AT was relaxed or stretched , SWE helped to confirm and quantify pathologic tendon softening in patients with tendonopathy in the midportion of the AT and did not reveal modifications of viscoelastic anisotropy in the tendon . Tendon softening assessed by using SWE appeared to be highly specific , but sensitivity was relatively low Objective The aim of this study was to investigate whether ultrasound elastography can demonstrate the outcome of the treatment in comparison with gray-scale imaging . Methods Sixteen patients ( mean age , 46.9 years ) with plantar fasciitis were prospect ively enrolled after unsuccessful conservative treatment . Individuals grade d their heel pain on a 100-mm visual analogue scale ( VAS ) and underwent gray-scale ultrasonography and sonoelastography . Collagen was injected in the heels . Fascial thickness and hypoechogenicity , perifascial edema , and plantar fascial elasticity were evaluated . Follow-up sonoelastography and VAS grading were done 3 months after the injection . Statistical analyses were performed by the paired t test and the Fisher exact test . A P < 0.05 was considered statistically significant . Results Mean plantar fascial thickness showed insignificant decrease on follow-up ( from 4.30 [ 1.37 ] to 4.23 [ 1.15 ] mm , P = 0.662 ) . Fascial hypoechogenicity and perifascial edema did not change significantly after treatment . The mean strain ratio of the plantar fascia was significantly increased ( from 0.71 [ 0.24 ] to 1.66 [ 0.72 ] , P = 0.001 ) . Softening of the plantar fascia decreased significantly after injection ( from 12 to 3 ft , P = 0.004 ) . Twelve ( 75 % ) of 16 patients showed significant VAS improvement at the follow-up . Conclusions Sonoelastography revealed a hardening of the plantar fascia after collagen injection treatment and could aid in monitoring the improvement of the symptoms of plantar fasciitis , in cases where gray-scale imaging is inconclusive Purpose To investigate the feasibility of real-time sonoelastography in the assessment of the mechanical tendon properties in small unilateral supraspinatus tears , to describe the sonoelastographic properties of the torn supraspinatus tendons and to correlate real-time sonoelastography findings with clinical results and demographic data . Methods All the patients presenting for a unilateral rotator cuff tear were prospect ively scrutinized . Clinical evaluation included complete physical examination , VAS , Quick DASH , Constant – Murley score , Simple Shoulder Test , ASES score and UCLA score . Radiological evaluation was performed with conventional ultrasounds and real-time sonoelastography ; this is a noninvasive method that uses ultrasounds to evaluate the mechanical properties of tissues , reflecting their quality , that can be semi-quantitatively estimated using the strain index . During the enrolment period , 92 patients were scrutinized , and 50 were included in the study . Results A negative correlation between strain index and VAS for pain , a strong positive correlation between strain index and Constant – Murley score and ASES score were found . Comparable results were observed in male and female patients , but in males , we found a strong positive correlation also for Simple Shoulder Test and UCLA score . Conclusions Real-time sonoelastography was a feasible method applicable in the assessment of tendon quality in small supraspinatus tears , and its findings correlated with the clinical results of the patients . In day-by-day clinical practice , this information is very important because quality of tendons is one of the most important prognostic factors for surgeons performing rotator cuff repair . Level of evidence III Abstract Purpose To evaluate the sonoelastographic features of Achilles tendon healing after percutaneous treatment using real-time sonoelastography , a new tool able to quantify deformation in biological tissues . Methods Patients with atraumatic Achilles tendon ruptures , treated with a percutaneous technique , were assessed . Sonoelastographic evaluations were performed at the myotendinous junction , tendon body/lesion site and osteotendinous junction , both for the operated and contralateral side , at 40 days , 6 months and 1 year after surgery . Using st and ard regions of interest , the “ strain index ” ( SI ) was calculated as an indicator of tendon elasticity . Clinical outcomes were assessed by the ATRS question naire at 6 months and 1 year post-operatively and correlated with sonoelastographic findings . Sixty healthy tendons from 30 volunteers were used to provide a healthy control range . Results Twenty-five patients were recruited for this study . The SI in treated tendons showed progressive stiffening over time , especially at myotendinous junction and at the site of the sutured lesion , result ing in significantly higher stiffness than both the contralateral tendon and healthy volunteers . Peak thickness of treated tendons occurred at 6 months , with a tendency to reduce at 1 year , while never achieving a normal physiological state . Greatest remodelling was seen at the lesion site . The contralateral tendon showed significant thickening at the myotendinous and osteotendinous junctions . The SI of the contralateral tendon was found to be stiffer than physiological values found in the control group . ATRS score improved significantly between 6 months and 1 year , being negatively correlated with the SI ( p < 0.001 ) . Conclusion RTSE showed that operatively treated Achilles tendons become progressively stiffer during follow-up , while the ATRS score improved . From a biomechanical point of view , at 1 year after surgery Achilles tendons did not show a “ restitutio ad integrum ” . Real-time sonoelastography provides more qualitative and quantitative details in the diagnostics and follow-up of Achilles tendon conditions as the post-operative evolution of the repairing tissue . Level of evidence Diagnostic and therapeutic study , Level III RATIONALE AND OBJECTIVES Shear wave elastography ( SWE ) has been shown to be a powerful tool to estimate tissue stiffness . The aim of this study was to compare the diagnostic accuracy of SWE to that of st and ard ultrasound ( US ) ( combined use of B-mode US and power Doppler [ PD ] US ) for diagnosing tendinopathies . MATERIAL S AND METHODS This is a prospect i ve institutional review board-approved study on 112 participants ( mean age 42 ± 13.4 years ) with chronic ( > 6 months ) tendon pain in Achilles , patellar , or epicondylar tendons . Participants were systematic ally examined with US , PD , and SWE using a high-resolution linear 15 MHz probe ( SuperSonic Imagine ) . A semiquantitative analysis of SWE color charts and a quantitative region of interest-based analysis of tendon elasticity were performed . SWE values of symptomatic and healthy tendons were compared by using Student t test . Clinical symptom scores served as the st and ard of reference . US findings were compared to clinical symptom scores by using Spearman correlation . RESULTS At semiquantitative analysis of SWE color charts , symptomatic tendons were rated as " soft " in 80/140 ( 57.1 % ) , as " intermediate " in 54/140 ( 38.6 % ) , and as " rigid " in 6/140 ( 4.3 % ) . Healthy tendons were rated as " soft " in 8/84 ( 10 % ) , as " intermediate " in 31/84 ( 37 % ) , and as " rigid " in 45/84 ( 53 % ) . At quantitative analysis , symptomatic tendons exhibited significantly lower mean SWE values ( 60.3 kPa/4.48 m/s ; range 15.3 - 201.4 kPa/2.26 - 14.18 m/s ) than healthy tendons ( 185 kPa/7.85 m/s ; range 56 - 265 kPa/4.32 - 9.23 m/s ) ( P = 0.0004 ) . SWE values correlated closely with patients ' clinical symptoms obtained by clinical scores ( r = 0.81 ) . Overall sensitivity of conventional US and PD in detecting tendinopathies could be enhanced from 67.1 % ( 94/140 ) to 94.3 % ( 132/140 ) when combined with SWE . CONCLUSIONS SWE is a simple way to estimate tissue stiffness and , by reduced tissue rigidity , to identify tendon pathology . SWE significantly increases the diagnostic accuracy of tendon sonography and may prove to be a sensitive tool to early detect or monitor tendinopathy The objective of this study was to investigate the role of real-time sonoelastography ( RTSE ) in patients with lateral epicondylitis ( LE ) and whether it is associated with clinical parameters . Seventeen patients with unilateral LE were enrolled in the study . The healthy elbows of the participants constituted the control group . Using B-mode ultrasound , color Doppler ultrasound , and RTSE , 
    Output:
    
Conclusion SE appears to be a very useful diagnostic tool , in particular in tendon pathology .
This is a dynamic examination , provides an immediate evaluation of the tissue elasticity , and may be useful in recognizing tendon abnormalities and in implementing the information available with conventional US .