***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: Abstract . The objectives of this study were twofold : ( a ) to assess safety and tolerability of the hepatobiliary MR contrast agent MnDPDP ; and ( b ) to investigate the sensitivity of MnDPDP-enhanced MRI , in comparison with dual-phase spiral CT , in the detection of hepatocellular carcinoma ( HCC ) in cirrhosis . Fifty patients with liver cirrhosis and histologically proven HCC were enrolled in a prospect i ve phase-IIIB clinical trial . All patients underwent evaluation with dual-phase spiral CT and pre-contrast and post-contrast MRI at 1.5 T. The MR examination protocol included spin-echo ( SE ) and gradient-recalled-echo ( GRE ) T1-weighted images acquired before and 60–120 min after administration of 0.5 μmol/kg ( 0.5 ml/kg ) MnDPDP ( Teslascan , Nycomed Amersham , Oslo , Norway ) ; and fast T2-weighted SE images obtained solely before contrast injection . Gold st and ard was provided by findings at Lipiodol CT in combination with follow-up spiral CT studies , which were repeated at 4-month intervals over a 10- to 27-month ( mean ± SD 20.1 ± 5.1 months ) follow-up period . No serious adverse event occurred . Eighty tumors ranging 0.8–9.1 cm in diameter ( mean ± SD 3.2 ± 2.4 cm ) were detected by Lipiodol CT or confirmed as cancerous foci by follow-up CT studies . Pre-contrast MRI detected 38 of 80 lesions ( 48 % ) ; MnDPDP-enhanced MRI , 65 of 80 lesions ( 81 % ) ; pre-contrast plus post-contrast MRI , 69 of 80 lesions ( 86 % ) ; and dual-phase spiral CT , 64 of 80 lesions ( 80 % ) . The difference between unenhanced and MnDPDP-enhanced MRI was statistically significant ( p < 0.001 ) . The difference between MRI ( pre-contrast plus post-contrast ) and dual-phase spiral CT was not statistically significant ( p = 0.33 ) . The confidence in the final diagnosis , however , was significantly higher for MRI as compared with spiral CT ( p < 0.001 )  . MnDPDP  is a safe and well-tolerated hepatobiliary MR contrast agent . Magnetic resonance imaging with use of MnDPDP is significantly more sensitive than unenhanced MRI and as good as dual-phase spiral CT for detection of HCC in cirrhosis The purpose of this study was to evaluate the value of Ferumoxide-enhanced magnetic resonance ( MR ) imaging in the detection of hepatic metastases in high-risk patients treated for colorectal cancer that have rising CEA . We used 19 patients treated previously for colorectal cancer with rising CEA levels underwent an unenhanced T(1)-weighted ( T1W ) , T(2)-weighted ( T2W ) , STIR , and Ferumoxide-enhanced hepatic MRI . Following these studies , a laparotomy was performed and the liver was evaluated by palpation and intraoperative ultrasound . Two observers who were blinded to surgical results evaluated each MR sequence separately . The number of lesions considered highly suspicious for metastatic lesions were determined for each sequence and were compared to the results of surgery . The McNemar test was used to compare the outcomes of the different sequences . MR Imaging was unable to detect small ( < 5 mm ) metastases discovered at surgery . The best non-contrast sequences for detecting metastases were the STIR with 42 % sensitivity , 83 % specificity and an overall accuracy of 56 % and the T1W sequence ( sensitivity 38 % , specificity 100 % , accuracy 57 % ) , which were not significantly different ( p 0.4 ) . The noncontrast T2W sequence had a sensitivity of 29 % and a specificity of 77 % with an overall accuracy of 46 % . When all pre contrast scans were grouped together the common sensitivity was 42 % , specificity was 77 % and accuracy was 54 % . The post-ferumoxide T(2)W scans had a sensitivity of 42 % , specificity of 85 % , and accuracy of 57 % , but did not detect any additional lesions . There was no statistical difference between the pre- and post-contrast studies with regard to identifying patients with metastatic disease ( p 0.1 ) . In conclusion , we found small hepatic metastases in patients with early signs of recurrent colorectal cancer are difficult to detect on MRI . Ferumoxide-enhanced MRI was unable to detect additional hepatic metastases and performed no better than unenhanced MRI in detecting small hepatic metastasis The purpose of this study was to compare the diagnostic accuracy of contrast-enhanced ultrasound ( CEUS ) with spiral computed tomography ( SCT ) for the characterization of focal liver lesions ( FLL ) and to determine the degree of correlation between the two techniques . Seventy-seven FLL ( 45 hepatocellular carcinomas ; 12 metastases ; ten hemangiomas ; two regenerating/dysplastic nodules ; eight focal nodular hyperplasias ) detected with ultrasound ( US ) were prospect ively evaluated by CEUS using a second-generation contrast agent and SCT ( with an interval of no more than one month between the two techniques ) . Independent observers made the most probable diagnosis and the results were compared with the final diagnoses ( histology n = 59 ; MRI n = 18 ) . Statistical analysis was performed by the Chi-square and Kappa tests . CEUS provided a correct , specific diagnosis in 69/77 ( 90 % ) of the FLL , while SCT did so in 67/77 ( 87 % ) . The sensitivity , specificity , and diagnostic accuracy for malignancy were 91 % , 90 % , and 91 % , respectively , for CEUS and 88 % , 89 % , and 88 % , respectively , for SCT . No statistically significant difference was found between CEUS and SCT in the characterization of FLL ( p > 0.05 ) . In addition , agreement between the two imaging techniques was good ( k = 0.75 ) . We conclude that CEUS and SCT provide a similar diagnostic accuracy in the characterization of FLL , with a good degree of correlation between the two techniques PURPOSE To qualitatively and quantitatively evaluate the diagnostic efficacy of the breath-hold magnetic resonance ( MR ) imaging sequences in widespread clinical use for detection and characterization of focal hepatic lesions . MATERIAL S AND METHODS Fifty patients with 143 lesions [ 57 hepatocellular carcinomas ( HCC ) , 10 borderline lesions , 18 metastatic tumors , 21 hemangiomas , and 37 cysts ] underwent single-shot fast spin echo ( SSFSE ) , fast spin echo ( FSE ) , and gadolinium-enhanced dynamic fast spoiled gradient-recalled acquisition in steady state ( FSPGR ) breath-hold MR imaging of the liver . Alternative free receiver operating characteristic ( AFROC ) analysis was performed to independently and prospect ively assess each sequence . RESULTS For solid lesions , dynamic FSPGR allowed the most sensitive lesion detection and produced the highest lesion conspicuity and lesion-liver contrast-to-noise ratio ( CNR ) . For non-solid benign lesions , SSFSE and FSE produced better results than dynamic FSPGR . SSFSE allowed the most sensitive detection and produced the best lesion conspicuity and lesion-liver CNR . CONCLUSION SSFSE and dynamic FSPGR comprise the optimal imaging protocol for breath-hold MR assessment of focal hepatic lesions . This combination of sequences allows acquisition of critical diagnostic information about both inherent T2 and T1 lesion contrast and lesion vascularity Purpose The purpose of the study was to introduce our protocol for contrast-enhanced multiphase dynamic ultrasonography ( US ) and examine the effectiveness of this method for characterizing liver tumors . Methods The subjects were 142 patients with liver tumors . The final diagnoses were 58 hepatocellular carcinomas ( HCCs ) , 4 cholangiocellular carcinomas ( CCCs ) , 14 metastases , 29 hemangiomas , 6 cases of focal nodular hyperplasia ( FNH ) , and 31 other benign lesions . The contrast agent used was Levovist . A wide-b and pulse inversion harmonic imaging mode was employed . Multiphase dynamic US was achieved by changing the sound transmission interval automatically from 0.3 s to 15.0 s according to a preset menu . Early arterial-phase images were observed at the short interval , and an equilibrium-phase image was observed at the longest interval . After a series of vascular images , a postvascular liver parenchymal image was obtained . Based on previously published criteria , the most compatible diagnosis was noted . The accuracy of this multiphase dynamic US technique for diagnosing focal liver lesions was examined by comparing our results with the final diagnosis based on a prospect i ve study . Results The overall accuracy of all 142 cases was 93.7 % . The sensitivity , specificity , and positive predictive value were , respectively , 100 % , 92.9 % , and 90.6 % for HCC ; 88.9 % , 97.6 % , and 84.2 % for metastasis or CCC ; 89.7 % , 100 % , and 100 % for hemangioma ; and 83.3 % , 100 % , and 100 % for FNH . Conclusion Contrast-enhanced multiphase dynamic US is a highly accurate , safe diagnostic tool for characterizing liver tumors Background : Hepatocellular carcinoma ( HCC ) is often detected at a relatively late stage when tumour size prohibits curative surgery . Screening to detect HCC at an early stage is performed for patients at risk . Aim : The aim of this study was to compare prospect ively the diagnostic accuracy and classification for management of the two state of the art secondline imaging techniques : triphasic spiral computer tomography ( CT ) and super paramagnetic iron oxide ( SPIO ) enhanced magnetic resonance imaging ( MRI ) . Patients : Sixty one patients were evaluated between January 1996 and January 1998 . Patients underwent CT and MRI  within a mean interval of 6.75 days . Methods : CT and MRI were evaluated blindly for the presence and number of lesions , characterisation of these lesions , and classification for management . For comparison of the data on characterisation , the CT and MRI findings were compared with histopathological studies of the surgical specimens and /or follow up imaging . Data of patients not lost to follow up were available to January 2001 . Results : SPIO enhanced MRI detected more lesions and overall smaller lesions than triphasic spiral CT ( number of lesions 189 v 124 ; median diameter 1.0 v 1.8 cm ; Spearman rank 's correlation coefficient 0.63 , p<0.001 ) . There was no significant difference in accuracy between CT and MRI for lesion characterisation . The agreement in classification for management was very good ( weighted kappa 0.91 , 95 % CI 0.83–0.99 ) . Conclusion : SPIO enhanced MRI detects more and smaller lesions , but both techniques are comparable in terms of classification for management . SPIO enhanced MRI may be preferred as there is no exposure to ionising radiation Background : In recent years , liver transplantation in patients with hepatocellular cancers and cirrhosis has been restricted to those with small cancers ( < 5 cm for solitary and <3 cm for multifocal HCC with <3 nodules ) . The selection of patients for liver transplantation is based on pre-operative imaging . The accuracy of imaging correlated with explant histology and the effect of tumour stage has not been evaluated in this selected population . Methods : In this study , prospect ively collected data for 30 patients who underwent orthotopic liver transplantation for cirrhosis complicated by small hepatocellular carcinoma ( HCC ) at a single centre have been review ed with the aim of correlating radiological findings , explant histology and patient outcome . Patients who underwent orthotopic liver transplantation between 1995 and 1999 had plain and contrast-enhanced dual-phase spiral CT ( DCT ) scans of the liver . Patients suspected of having HCC on CT scan or due to elevated serum alpha-fetoprotein underwent iodized oil CT ( IOCT ) . Following transplantation , the explanted liver was serially sectioned at 10-mm intervals and examined by a pathologist blinded to the results of imaging . Data collected prospect ively on imaging and histology were compared with outcome data . The median period of follow-up was 1,139 days ( range 690–1,955 days ) after transplantation . All patients were followed up by clinical assessment , assessment of serum alpha-protein levels and imaging when indicated . Results : All the patients transplanted fulfilled the selective criteria on the basis of imaging ( solitary HCC < 5 cm in diameter or multifocal HCC <3 cm in diameter with <3 nodules ) . Of the 30 patients transplanted , 46 HCCs were detected on explant histology with a median size of 24 mm ( range 6–75 mm ) . Ten patients had multifocal disease ( median number of lesions 2 , range 2–4 ) . No significant difference was observed between IOCT and DCT with regards to the sensitivity ( 67.4 vs. 68 % ) and specificity ( 78.97 vs. 88.6 % ) of detecting HCCs . IOCT had a positive predictive value of 78.9 % as compared to 82.8 % for DCT . IOCT had an overall sensitivity of 40 % as compared to 30 % for DCT in detect 
    Output:
    
The recommendations reported in the study are based on an extensive literature evaluation and were developed by considering the appropriateness of the choice of the imaging techniques while noninvasively detecting and characterizing focal liver lesions