***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: The diagnosis of a meniscal tear may require MRI , which is costly . Ultrasonography has been used to image the meniscus , but there are no reliable data on its accuracy . We performed a prospect i ve study investigating the sensitivity and specificity of ultrasonography in comparison with MRI ; the final outcome was determined at arthroscopy . The study included 35 patients with a mean age of 47 years ( 14 to 73 ) . There was a sensitivity of 86.4 % ( 95 % confidence interval ( CI ) 75 to 97.7 ) , a specificity of 69.2 % ( 95 % CI 53.7 to 84.7 ) , a positive predictive value of 82.6 % ( 95 % CI 70 to 95.2 ) and a negative predictive value of 75 % ( 95 % CI 60.7 to 81.1 ) for ultrasonography . This compared favourably with a sensitivity of 86.4 % ( 95 % CI 75 to 97.7 ) , a specificity of 100.0 % , a positive predictive value of 100.0 % and a negative predictive value of 81.3 % ( 95 % CI 74.7 to 87.9 ) for MRI . Given that the sensitivity matched that of MRI we feel that ultrasonography can reasonably be applied to confirm the clinical diagnosis before undertaking arthroscopy . However , the lower specificity suggests that there is still a need to improve the technique to reduce the number of false-positive diagnoses and thus to avoid unnecessary arthroscopy High resolution ultrasonography was done prospect ively in 51 adult patients with clinical ly suspected meniscal injuries to evaluate the sensitivity and specificity of ultrasonography as a primary diagnostic tool and to see if it was possible to evaluate the site , extent and size of the tear . All cases were confirmed arthroscopically ; ultrasonographic examination revealed inhomogenecity in 45 cases and this was accurate in 40 cases ; in 3 cases ultrasonography gave a false positive result and in 2 cases the wrong meniscus was shown to be torn . The six cases with no findings on ultrasonography were proven to have no meniscal tear . The sensitivity of ultrasonography as a screening test to rule out meniscal injuries was thus 100 % ; on the other h and the specificity ( false positive screening test ) was 54 % . It was no possible to determine the site , size or extent of the tear by the ultrasonographic examination . Even though magnetic resonance imaging is more accurate in giving an exact diagnosis , ultrasonography is an excellent primary diagnostic tool which is inexpensive with no side-effects , is readily available and has very good sensitivity and a reasonable specificity While magnetic resonance imaging ( MRI ) is often considered the " gold st and ard " diagnostic imaging modality for detection of meniscal abnormalities , it is associated with misdiagnosis in as high as 47 % of cases , is costly , and is not readily available to a large number of patients . Ultrasonographic examination of the knee has been reported to be an effective diagnostic tool for this purpose with the potential to overcome many of the shortcomings of MRI . The purpose of this study is to determine the clinical usefulness of ultrasonography for diagnosis of meniscal pathology in patients with acute knee pain and compare its diagnostic accuracy to MRI in a clinical setting . With Institutional Review Board approval , patients ( n = 71 ) with acute knee pain were prospect ively enrolled with informed consent . Preoperative MRI ( 1.5 T ) was performed on each affected knee using the hospital 's st and ard equipment and protocol s and read by faculty radiologists trained in musculoskeletal MRI . Ultrasonographic assessment s of each affected knee were performed by one of two faculty members trained in musculoskeletal ultrasonography using a 10 to 14 MHz linear transducer . Arthroscopic evaluation of affected knees was performed by one of three faculty orthopedic surgeons to assess and record all joint pathology , which served as the reference st and ard for determining presence , type , and severity of meniscal pathology . All evaluators for each diagnostic modality were blinded to all other data . Data were collected and compared by a separate investigator to determine sensitivity ( Sn ) , specificity ( Sp ) , positive predictive value ( PPV ) , negative predictive value ( NPV ) , correct classification rate ( CCR ) , likelihood ratios ( LR[+ ] and LR[- ] ) , and odds ratios . Preoperative ultrasonographic assessment of meniscal pathology was associated with Sn = 91.2 % , Sp = 84.2 % , PPV = 94.5 % , NPV = 76.2 % , CCR = 89.5 % , LR(+ ) = 5.78 , and LR(- ) = 0.10 . Preoperative  MRI assessment of meniscal pathology was associated with Sn = 91.7 % , Sp = 66.7 % , PPV = 84.6 % , NPV = 80.0 % , CCR = 81.1 % , LR(+ ) = 2.75 , and LR(- ) = 0.13 . Ultrasonography was two times more likely than MRI to correctly determine presence or absence of meniscal pathology seen arthroscopically in this study . Ultrasonography is a useful tool for diagnosis of meniscal pathology with potential advantages over MRI . Based on these data and available portable equipment , ultrasonography could be considered for use as a point-of-injury diagnostic modality for meniscal injuries PURPOSE The aim of this prospect i ve study was to evaluate preoperative three-dimensional ultrasound scans for the detection of meniscal lesions with a special focus on interobserver reliability . METHODS Forty one patients with clinical signs of meniscal lesions were preoperatively examined by ultrasound using the 3-D technique ( 11.7 MHz linear transducer ) . The 3-D data set was stored and examined by a second orthopaedic surgeon . The second ultrasound examiner was blinded to the results of the first . Any meniscal pathology was confirmed arthroscopically and documented . RESULTS At arthroscopy eight lateral meniscal lesions and 57 medial meniscal lesions were detected at different locations . The sensitivity and specificity of the original ultrasound examination was acceptable whereas the results of the second ultrasound session were not as sensitive . CONCLUSION Three-D-ultrasound with a high resolution transducer , in the h and s of an experienced operator , provides acceptable results in the detection of meniscal lesions , however , analysis of the volume data set from the 3-D ultrasound investigation indicates that it does not offer sufficient accuracy for clinical use Purpose To prospect ively evaluate whether age of patient affects diagnostic accuracy of sonography and magnetic resonance imaging ( MRI ) in the diagnosis of medial meniscal tears . Methods We prospect ively evaluated 74 consecutive patients ( 54 males and 20 females ) , in two different groups [ group A ( 37 patients ≤ 30 years ; mean age : 23.5 ± 5 years ) and group B ( 37 patients > 30 years ; mean age : 43.5 ± 9.35 years ) ] with clinical suspicion of medial meniscal tear . After inclusion , patients underwent ultrasonography and then MRI for signs of tearing . The ultrasonographic and MRI findings were compared with arthroscopic findings , which served as a gold st and ard for accurate detection of meniscal tearing . Results The sensitivity , specificity , positive and negative predictive values and accuracy of ultrasonography in detecting medial meniscal tears in group A were 100 , 88.9 , 96.5 , 100 , 97.3 % and in group B were 83.3 , 71.4 , 92.6 , 50 , 81.1 % , respectively . The sensitivity , specificity , positive and negative predictive values and accuracy of MRI  in group A were 100 , 88.9 , 96.5 , 100 , 97.3 % and in group B were 96.7 , 85.7 , 96.7 , 85.7 , 94.6 % , respectively . Conclusions Given the fact that the sensitivity and specificity of the results of knee sonography matched that of MRI in patients who were 30 years old or less , we suggest ultrasonography as an effective initial investigation for tears of medial meniscus in this group of patients . Patients with negative ultrasonographic findings will need no further investigation . Level of evidence Diagnostic studies —investigating a diagnostic test , Level II In a prospect i ve double-blind study we investigated internal knee disorders with ultrasound and compared the results with Magnetic Resonance Imaging ( MRI ) and arthroscopy . The aim was to determine the effectiveness of ultrasound  in diagnosing  Internal Derangement of the Knee ( IDK ) and to compare the results with MRI . Over an 18-months period , 81 patients were examined . All were male ; they had a mean age of 35 years . For various technical reasons 21 patients were subsequently excluded from the study . After initial clinical examinations , patients had an ultrasound and MRI scan at the same visit . Arthroscopy was performed within a month of this . Different radiologists who were unaware of the clinical findings independently reported on the ultrasound and MRI . The surgeon performing the arthroscopy was made aware only of the MRI findings . Structures accessed were the lateral and medial menisci and the anterior ( ACL ) and posterior ( PCL ) cruciate ligaments . Arthroscopy was taken as the gold st and ard . Ultrasound showed good sensitivity , ranging from 76 % for the ACL to 90 % for the medial meniscus , and excellent specificity , ranging from 92 % for the medial meniscus to 100 % for the ACL . Accuracy ranged from 86 % for the ACL to 98 % for the lateral meniscus . These figures were comparable to the MRI findings . We concluded that ultrasound is a simple , accurate , inexpensive and non-invasive way of assessing  internal knee disorders .  There is a learning curve , but results are similar to MRI BACKGROUND AND OBJECTIVE Publication bias and other sample size effects are issues for meta-analyses of test accuracy , as for r and omized trials . We investigate limitations of st and ard funnel plots and tests when applied to meta-analyses of test accuracy and look for improved methods . METHODS Type I and type II error rates for existing and alternative tests of sample size effects were estimated and compared in simulated meta-analyses of test accuracy . RESULTS Type I error rates for the Begg , Egger , and Macaskill tests are inflated for typical diagnostic odds ratios ( DOR ) , when disease prevalence differs from 50 % and when thresholds favor sensitivity over specificity or vice versa . Regression and correlation tests based on functions of effective sample size are valid , if occasionally conservative , tests for sample size effects . Empirical evidence suggests that they have adequate power to be useful tests . When DORs are heterogeneous , however , all tests of funnel plot asymmetry have low power . CONCLUSION Existing tests that use st and ard errors of odds ratios are likely to be seriously misleading if applied to meta-analyses of test accuracy . The effective sample size funnel plot and associated regression test of asymmetry should be used to detect publication bias and other sample size related effects The aim of this prospect i ve study was to assess the accuracy of modern ultrasonography in diagnostic imaging of meniscal tears . One hundred and sixty menisci were evaluated in 80 patients ( 42 females , 38 males , mean age=36.2 years , range=16 - 70 years ) . Inclusion criteria for the study were twofold : clinical suspicion of meniscal injury and clinical indication for  arthroscopy . Knee examination was performed with the Voluson 730 Expert ultrasound system ( General Electric ) . After sonographic examination , all patients underwent arthroscopic procedures within 1 - 4 days . The final diagnosis of meniscal tears was taken from surgical reports . The overall sensitivity , specificity , positive predictive value and negative predictive value of sonographic examination in the assessment of meniscal tears amounted to 85.4 % , 85.7 % , 67.3 % and 94.4 % , respectively . The statistical parameters were not statistically different in medial and lateral menisci . Age , sex , body mass index ( BMI ) , weight , physical activity , mechanism on injury , and time lapse from injury did not have a statistically significant impact on the usefulness of ultrasonography . The highest sensitivity ( > 90 % ) was obtained in medial menisci and in patients with a BMI > 25 . The highest specificity ( > 90 % ) was obtained in lateral menisci , in patients after twisting injuries , in sports injuries , and in recent injuries ( time lapse from the injury < 1 month ) . The positive predictive value ( PPV ) of sonographic examination  was higher than 90 % only in recent injuries ( < 1 month ) , however , the negative predictive value of ultrasound  is high , being less than 90 % in males with lesions of lateral menisci and in sequelae of sports injuries 
    Output:
    
This meta- analysis indicates that 2-dimensional ultrasound is useful , and could be routinely used for estimating meniscal injuries in the human knee joint