***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 
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    ***EXAMPLES*** 
    Input: Objective To evaluate the clinical efficacy of magnetic resonance imaging ( MRI ) of the knee in acute injuries with indeterminate clinical findings , using arthroscopy as a gold st and ard . Design A prospect i ve double-blind study was performed . All patients underwent MRI on a 1.5 T magnet using dual spin echo pulse sequences . This was followed by arthroscopy . Setting Tertiary care referral center . Patients Twenty-three patients with an average age of 26 years satisfied the study criteria . Patients had to have been seen by one of two orthopaedic surgeons within 6 weeks of sudden trauma to the knee complicated by a hemarthrosis , clinical assessment of which was equivocal . Results The respective sensitivity and specificity for  MRI  of the knee were 90 % ( 18/20 ) and 67 % ( 2/3 ) for detecting any anterior cruciate ligament injury , 50 % ( 1/2 ) and 86 % ( 18/21 ) for detecting medial meniscal tears , and 88 % ( 7/8 ) and 73 % ( 11/15 ) for detecting lateral meniscal tears . MRI also identified injuries that could not be assessed on arthroscopy , including 14 bone bruises , five posterior cruciate ligament tears , nine medial collateral ligament tears , and one lateral collateral ligament tear . The detection of composite injury requiring surgical intervention yielded a sensitivity of 100 % ( 16/16 ) and a specificity of 71 % ( 5/7 ) . Prospect i ve use of  MRI evaluation of the knee could have prevented 22 % ( 5/23 ) of diagnostic arthroscopic procedures . Conclusion Equivocal clinical findings in patients with acute knee injury should lead to use of MRI in an appropriate clinical setting . To our knowledge a prospect i ve study of the efficacy of MRI of the knee in this patient population has not been reported . In the presence of such inclusion criteria , the results of our study support the use of early  MRI  to guide further surgical management Abstract The results of magnetic resonance imaging ( MRI ) were compared with those of arthroscopy in a prospect i ve series of 244 patients . A dedicated system for MRI of limbs and peripheral joints – the 0,2-T Artoscan ( Esaote , Italy ) – was used for imaging knee joint lesions . T1-weighted spin-echo sagittal images , T2-weighted gradient-echo coronal images , and axial views for lesions of the femoropatellar joint were acquired . Paraxial sagittal and oblique coronal views were obtained for imaging of the cruciate ligaments . This protocol allowed excellent visualization of the cruciate ligaments and medial and lateral meniscus in almost all patients . Compared with arthroscopy performed within 48 h after imaging , the sensitivity , specificity , and accuracy were respectively 93 % , 97 % , and 95 % for tears of the medial meniscus ; 82 % , 96 % , and 93 % for tears of the lateral meniscus ; 100 % , 100 % , and 100 % for tears of the posterior cruciate ligament ; 98 % , 98 % , and 97 % for tears of the anterior cruciate ligament ; and 72 % , 100 % , and 92 % for full-thickness articular cartilage lesions . The examination can be performed within 30–45 min at lower cost than diagnostic arthroscopy . MRI with a 0.2-T magnet is a safe and valuable adjunct to the clinical examination of the knee and an aid to efficient preoperative planning A prospect i ve double-blind study was undertaken to evaluate the usefulness of magnetic resonance imaging in the accurate interpretation of pathological intra-articular changes in the knee . Forty-seven patients who were scheduled to have arthroscopy and three patients who wer to have arthrotomy volunteered for magnetic resonance imaging preoperatively . The radiologists had no clinical or roentgenographic information about the patients before the evaluation of the magnetic resonance images , and the radiologists ' interpretations were unknown to the surgeon before the arthroscopy or arthrotomy was done . Our important observations were limited to the findings in the menisci and in the anterior cruciate ligament . Magnetic resonance imaging had a positive predictive value of 75 per cent , a negative predictive value of 90 per cent , a sensitivity of 83 per cent , and a specificity of 84 per cent for pathological findings in the menisci . For complete tears of the anterior cruciate ligament , the positive predictive value was 74 per cent ; the negative predictive value , 70 per cent ; the sensitivity , 61 per cent ; and the specificity , 82 per cent . We believe that magnetic resonance imaging , when combined with clinical and roentgenographic examination , provides the most accurate non-invasive source of information that is currently available for pathological findings in the menisci and in the anterior cruciate ligament The aim of this study was to detect the accuracy of routine magnetic resonance imaging ( MRI ) done in different centres and its agreement with arthroscopy in meniscal and ligamentous injuries of the knee . We prospect ively examined 70 patients ranging in age between 22 and 59 years . History taking , plain X-ray , clinical examination ,  routine MRI and arthroscopy  were done for all patients .  Sensitivity , specificity , accuracy , positive and negative predictive values , P value and kappa agreement measures were calculated . We found a sensitivity of 47 and 100 % , specificity of 95 and 75 % and accuracy of 73 and 78.5 % , respectively , for the medial and lateral meniscus . A sensitivity of 77.8 % , specificity of 100 % and accuracy of 94 % was noted for the anterior cruciate ligament ( ACL ) . We found good kappa agreements ( 0.43 and 0.45 ) for both menisci and excellent agreement ( 0.84 ) for the ACL . MRI shows high accuracy and should be used as the primary diagnostic tool for selection of c and i date s for arthroscopy . Level of evidence : 4.RésuméLe but de cette étude est de détecter un examen de routine l’IRM et la bonne correspondance entre ces constatations et les constatations arthroscopiques des lésions méniscales ou des lésions ligamentaires du genou . Nous avons réalisé une étude prospect i ve de 70 patients âgés de 22 à 59 ans avec analyse de l’histoire clinique , des radiographies , de l’examen clinique , de l’examen IRM et des constatations arthroscopiques . La sensitivité , la spécificité et l’exactitude des constatations ont été évaluées de manière statistique . Nous avons trouvé respectivement une sensitivité de 47 % et 100 % , une spécificité de 95 % et 75 % et une exactitude des constatations de 73 % et 78,5 % , pour les lésions du ménisque interne ou du ménisque latéral . En ce qui concerne les ligaments croisés , la sensitivité est de 77,8 % , la spécificité de 100 % et l’exactitude des constatations de 94 % avec une bonne correspondance Kappa ( 0,43 et 0,45 ) pour les ménisques et 0,84 pour le ligament croisé antérieur . L’IRM peut donc être utilisée comme un élément tout à fait sûr et routinier concernant le diagnostic primaire des lésions miniscales ou des lésions ligamentaires chez les patients devant bénéficier d’une  arthroscopie  . Niveau d’évidence : 4 Rapidly progressing medical technology sometimes obscures the importance of history and physical examination . This study was design ed to assess the value of MRI and clinical examination in the diagnosis of ligamentous and meniscal knee injuries in comparison with arthroscopic findings . In the year 2003 - 2004 , we conducted a prospect i ve , single blind study to assess ligamentous and meniscal injuries of the knee in patients with acute knee trauma . The mean age was 27.9 years . The sex distribution was 81.4 % male and 18.6 % female ; 42.9 % of injuries affected the right knee and 57.1 % the left knee . All the included patients were ordered a MRI , executed in five separate centres . All patients underwent arthroscopy by the author . Arthroscopic findings were the diagnostic reference . Clinical examination was accurate in 91.4 % , and  MRI  in 88.5 % of anterior cruciate ligament injuries . For posterior cruciate ligament injuries , clinical accuracy was 100 % and MRI 94.6 % . Clinical examination was accurate in 96.9 % and  MRI  in 85.9 % of medial meniscal injuries . For lateral meniscus injuries , clinical accuracy was 85.4 % and MRI 73.8 % . MRI findings showed the lowest correlation with arthroscopic findings in lateral meniscus injuries ( r = 0/47 ) . Clinical diagnostic performance was poorest in case of combined cruciate ligament and meniscal injuries . We found an excellent correlation between  MRI and clinical findings . However , when MRI is normal , high clinical suspicion and a skilled clinical examination are more reliable This prospect i ve double-blind study was design ed to evaluate the capability of magnetic resonance imaging to serve as a diagnostic tool in patients who have a clinical ly suspected disorder of the meniscus . The imaging studies provided a diagnostic accuracy of 72 per cent , a sensitivity of 88 per cent , and a specificity of 57 per cent . The positive and negative predictive values were 66 and 83 per cent . The diagnostic sensitivity was 94 per cent for lesions of the medial meniscus ; this value differed significantly from that of 78 per cent for lesions of the lateral meniscus ( p less than 0.05 ) . The 37 per cent specificity for lesions of the medial meniscus was extremely low compared with the rate of 69 per cent for lesions of the lateral meniscus ( p less than 0.01 ) . In the intermediate part of the meniscus , the diagnostic sensitivity was 37 per cent on the medial side and 23 per cent on the lateral side ; these values were significantly less than the average of 74 per cent for the other meniscal segments ( p less than 0.001 ) . The imaging studies provided an over-all accuracy of 67 per cent in the detection of degeneration of the meniscus , 78 per cent in the identification of meniscal tears , and 82 per cent in the delineation of postoperative lesions Abstract Purpose Rupture of the anterior cruciate ligament ( ACL ) is a common injury , often presenting with a typical injury pattern . Historically , the literature indicates that the accuracy of diagnosis of ACL ruptures is poor at the initial medical consultation . The aims of this study were to determine : the mechanism of injury ; changes in accuracy of diagnosis of ACL ruptures at initial presentation over the last decade ; and the effect of subsequent delay in diagnosis and definitive treatment . Methods A prospect i ve cohort of one hundred and thirty-two consecutive patients who underwent ACL reconstruction between 2005 and 2009 were analysed . The median age of the patients was 18 years ( 12–57 ) . Sixteen patients were excluded due to chronic ACL injury . Results One hundred and sixteen patients ( 117 ACL ruptures ) were included in the analysis . A typical injury pattern was documented in 87 ( 74.4 % ) of cases . The most common sporting activities associated with an ACL injury were football ( 35.3 % ) , skiing ( 21.6 % ) and rugby ( 10.3 % ) . The majority of patients ( 67.5 % ) sought medical attention within 1 week from time of injury . The correct diagnosis of an ACL rupture was made in 33 cases ( 28.2 % ) at the initial medical consultation . The diagnosis was made following medical consultation in 13 ( 11.1 % ) of cases with the use of magnetic resonance imaging and 6 ( 5.1 % ) cases at arthroscopy . The median time to diagnosis was 6 weeks ( 0–192 ) , and the median time to ACL reconstruction was 24 weeks ( 1–240 ) . A delay in diagnosis of > 6 months was associated with a medial meniscal tear rate of 72.2 % compared to 23.1 % if the diagnosis was made within 4 months of the injury ( p < 0.05 ) . Conclusions Despite a ‘ typical ’ mechanism of injury leading to ACL rupture , the rate of initial diagnosis in the UK still remains poor . This often leads to an unnecessary delay in the diagnosis and subsequent treatment and increases the risk of secondary injury to the knee . A delay in diagnosis of > 6 months was associated with an increased medial meniscal tear rate . Patients who present with a ‘ typical ’ injury pattern should therefore be referred for further assessment by a knee specialist within 6 weeks . Level of evidence IV The results of selective magnetic resonance imaging of the knee were compared with those of arthroscopy in a prospect i ve series of fifty patients . A specifically design ed protocol for imaging , producing T1 sagittal images interleaved at four millimeters while the patient 's foot was in 20 degrees of external rotation , was utilized . This technique , called selective magnetic resonance imaging , yielded excellent visualization of the posterior cruciate ligament , medial meniscus , and lateral meniscus in all patients . However , in only 7 
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Magnetic field strength had no significant effect on accuracy .