***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: Objective The aim of the study was to evaluate the feasibility of using 3-dimensional transvaginal ultrasound ( 3D-TVUS ) to diagnose the extent of invasive cervical cancer . Methods Using 3D-TVUS , we prospect ively examined 24 patients diagnosed with locally advanced invasive cervical cancer before primary surgery . Parametrial , vaginal , bladder , and rectal invasion , alongside cancer staging , was evaluated in the orthogonal planes . We compared the preoperative clinical , magnetic resonance imaging ( MRI ) , and ultrasonography findings with the histological results from surgery . Results With respect to cancer staging , accuracy was 62.5 % with clinical examination , 40.9 % with MRI , and 66.7 % with TVUS . Magnetic resonance imaging demonstrated both low specificity ( 64.3 % ) and accuracy ( 68.2 % ) for nodal involvement . For the detection of parametrial invasion : sensitivity was 25 % with clinical exanimation , 75 % with MRI , and 75 % with TVUS ;  specificity was 55.6 % with MRI and 90 % with TVUS ; accuracy was 59 % with MRI and 87.5 % with TVUS . Although there was no case with bladder or rectal invasion , TVUS and MRI showed high specificity for the assessment of these . Clinical examination was useful for the detection of vaginal involvement . Conclusions Preoperative 3D-TVUS may prove to be an excellent method for the evaluation of locally advanced cervical cancer . Transvaginal ultrasound also has advantages over MRI for the assessment of tumor volume and Doppler velocimetry and is a low-cost alternative . However , TVUS can not identify nodal or distant metastasis Thirty-seven patients with carcinoma of the cervix were prospect ively staged by examination under anaesthesia ( EUA ) , transvaginal and transrectal ultrasound , computed tomography ( CT ) and magnetic resonance imaging ( MRI ) . Pathological correlation was available for 20 patients . In the pathologically staged patients , EUA agreed with the staging in 17 , understaging three patients . Endosonography agreed with the staging in 19 , CT in 16 and MRI in 18 patients . For the remaining 17 patients , endosonography agreed with the EUA findings in 13 , CT in 12 and MRI in 12 . This study has shown that endosonography and MRI are more accurate than CT in the local staging of carcinoma of the cervix . Computed tomography was least accurate in staging early tumours and differentiating between Stage Ib and IIb disease . Lymph node involvement was detected with equal frequency by both CT and MRI . Magnetic resonance imaging was useful in identifying vaginal and bladder wall involvement and in one patient showed features due to an unsuspected early pregnancy PURPOSE The aim of this prospect i ve study was to compare the diagnostic accuracy of transvaginal sonography ( TVS ) with that of MRI in the local staging of cervical cancer . METHODS All consecutive patients diagnosed with invasive carcinoma of the cervix over a 3-year period underwent  MRI of the pelvis and TVS according to a st and ardized protocol . RESULTS In total , 46 patients were recruited to the study . We found a strong correlation between MRI and TVS in the assessment of tumor volume in both early-stage and advanced-stage disease ( p < 0.0001 ) . Both MRI and TVS had a sensitivity of 80 % , a specificity of 50 % , and a diagnostic accuracy of 63.6 % for the detection of stromal invasion in early-stage disease . For the detection of parametrial invasion , we found sensitivity rates of 40 % for MRI and 86 % for TVS ; specificity rates of 78.8 % for MRI and 20 % for TVS ; and diagnostic accuracy rates of 89 % for MRI and 78.7 % for TVS . A matched- sample analysis revealed that there was no statistically significant difference between MRI and TVS in the assessment of stromal or parametrial invasion ( p = 0.06 ) . CONCLUSIONS TVS performed by a dedicated gynecologic radiologist is a feasible and economic imaging modality with a diagnostic accuracy comparable to that of MRI . It may be used as an adjunct to MRI for the local staging of invasive cervical cancer or to allow for rapid and confident triage of patients into operative and nonoperative categories for management in the gynecologic outpatient setting OBJECTIVES To prospect ively assess the diagnostic performance of transvaginal ultrasound and magnetic resonance imaging ( MRI ) , using histology as the gold st and ard , with regard to the presence , size , and extent of invasive cervical cancers and the detection of metastatic lymph nodes . METHODS This was a prospect i ve study design ed to examine patients with invasive cervical cancer by means of ultrasonography and MRI within 1 week before surgery . We included patients with early cervical cancer planned for primary surgery and patients with locally advanced cervical cancer planned for surgery after neoadjuvant treatment . RESULTS An invasive cervical cancer tumor was confirmed in the 33 patients triaged for primary surgery . A residual tumor mass was documented in 27 out of 35 patients ( 77 % ) who underwent surgery after neoadjuvant treatment , with no residual tumor in eight ( 23 % ) cases . Transvaginal ultrasound and MRI examinations showed the presence of the tumor mass in 56/60 ( 93 % ) and in 53/60 ( 88 % ) cases , respectively . Ultrasound and MRI detected the depth of stromal invasion to be greater than two-thirds with a sensitivity of 100 % ( 16/16 ) and 94 % ( 15/16 ) ( P = 1 ) and a false-positive rate of 25 % ( 13/52 ) and 15 % ( 8/52 ) ( P = 0.58 ) , respectively . Both ultrasound and MRI provided low sensitivities ( 3/5 , 60 % and 2/5 , 40 % respectively , P = 1 ) and the same false-positive rate ( 7/63 , 11 % ) for the presence of parametrial infiltration . One of the 11 patients with metastatic lymph nodes was detected at ultrasound examination ( sensitivity 9 % ) with no false-positive cases , while MRI correctly identified three positive cases ( sensitivity 27 % , 3/11 ) with two false-positive cases ( false positive rate 4 % , 2/55 ) . CONCLUSIONS Ultrasound and MRI had similar sensitivity and specificity with regard to the parameters investigated . Ultrasound has the advantages over MRI of low cost , widespread availability and of being a relatively quick procedure . Ultrasound should be considered as a suitable diagnostic method in the preoperative work-up of cervical cancer 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 OBJECTIVE To compare the diagnostic accuracy of ultrasound ( US ) and magnetic resonance imaging ( MRI ) in the preoperative assessment of early-stage cervical cancer using pathologic findings as the reference st and ard . PATIENTS AND METHODS Prospect i ve multi-center trial enrolling 209 consecutive women with early-stage cervical cancer ( FIGO IA2-IIA ) scheduled for surgery . The following parameters were assessed on US and MRI and compared to pathology : remaining tumor , size , tumor stromal invasion<2/3 ( superficial ) or ≥2/3 ( deep ) , and parametrial invasion . RESULTS Complete data were available for 182 patients . The agreement between US and pathology was excellent for detecting tumors , correctly classifying bulky tumors ( > 4 cm ) , and detecting deep stromal invasion ( kappa values 0.84 , 0.82 , and 0.81 respectively ) ; and good for classifying small tumors ( < 2 cm ) and detecting parametrial invasion ( kappa values 0.78 and 0.75 , respectively ) . The agreement between MRI and histology was good for classifying tumors as < 2 cm , or > 4 cm , and detecting deep stromal invasion ( kappa values 0.71 , 0.76 , and 0.77 , respectively ) . It was moderately accurate in tumor detection , and in assessing parametrial invasion ( kappa values 0.52 and 0.45 , respectively ) . The agreement between histology and US was significantly better in assessing residual tumor ( p<0.001 ) and parametrial invasion ( p<0.001 ) than the results obtained by MRI . Imaging methods were not significantly influenced by previous cone biopsy . CONCLUSION US and MRI are highly accurate for the preoperative assessment of women with early-stage cervical cancer , although US may be more accurate in detecting residual tumors and assessing parametrial invasion There were 732 evaluable patients with primary , previously untreated , histologically confirmed stage I squamous carcinoma of the cervix with greater than or equal to 3-mm invasion . Of these , 645 had no gross disease beyond the cervix/uterus , had negative paraaortic lymph nodes , and had undergone a radical hysterectomy with pelvic lymphadenectomy .  The 3-year disease-free interval ( DFIs ) for the 545 patients with negative pelvic nodes was 85.6 % , and for the 100 with positive pelvic nodes , 74.4 % . A large number of pelvic nodes involved with tumor was not correlated with a poorer prognosis ; the DFIs were 72.1 , 86.4 , and 64.6 % for one , two , and three or more positive pelvic nodes , respectively . DFI correlated strongly with depth of tumor invasion , both in absolute terms ( mm ) and infractional thirds . The DFI was 94.6 % for less than or equal to 5 mm , 86.0 % for 6 - 10 mm , 75.2 % for 11 - 15 mm , 71.5 % for 16 - 20 mm , and 59.5 % greater than or equal to 21 mm . In fractional terms , the DFI was 94.1 % for superficial third , 84.5 % for middle third , and 73.6 % for deep third invasion . With respect to clinical tumor size , the DFIs were 94.8 , 88.1 , and 67.6 % for occult , less than or equal to 3 cm , and greater than 3 cm , respectively . The DFI was 77.0 % for those with positive capillary-lymphatic spaces ( CLS ) and 88.9 % for those with negative CLS . Tumor grade and parametrial status correlated with DFI . DFI was not significantly different for age , disease status of the surgical margins , tumor description ( e.g. , exophytic ) , quadrant involved with tumor , uterine extension , and keratinizing status of tumor cells . Clinical tumor size , CLS , and depth of tumor invasion were independent prognostic factors 38 women with biopsy proven untreated cervical carcinoma were prospect ively studied with transrectal ultrasound ( TRUS ) , spiral computed tomography ( SCT ) and magnetic resonance imaging ( MRI ) .  20 women had radical hysterectomy and pelvic lymphadenectomy  with detailed histological evaluation of the parametra . The echographic features of cervical carcinoma on TRUS are a hypoechoic ( 60 % ) or isoechoic ( 40 % ) ( relative to normal uterine muscle/cervical stroma ) , poorly defined mass lesion with indistinct margins in an enlarged cervix . This relatively high percentage of isoechoic tumours and relative lack of contrast resolution may pose a problem in the identification of some tumours , and to our knowledge has not been previously reported . Further limitations of TRUS are in the evaluation of advanced cervical cancer , due to bulky tumours rendering poor access to the parametrium and pelvic sidewall . The overall accuracy in staging of early cervical cancer ( less than stage 2b ) was 85 % for examination under anaesthesia ( EUA ) , 75 % for TRUS , 65 % for MRI and 50 % for SCT . The positive predictive value in evaluating the parametra in this group of patients was also lower for SCT ( 14 % ) and MRI ( 33 % ) compared with TRUS ( 100 % ) . In the evaluation of advanced cervical cancer ( stage 2b or higher ) , there was poor correlation between TRUS and EUA , with MRI showing the best correlation with EUA . We conclude that SCT is inferior to both TRUS and MRI in the staging of 
    Output:
    
CONCLUSION Ultrasound and MRI have similar diagnostic performance for detecting parametrial infiltration in women with cervical cancer .
This might have relevance from the clinical point of view , since ultrasound is cheaper than MRI