***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: PURPOSE To compare the usefulness of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid ( Gd-EOB-DTPA ) and gadolinium diethylenetriaminepentaacetic acid ( Gd-DTPA ) in the diagnosis of focal liver lesions . MATERIAL S AND METHODS Thirty-one patients with focal liver lesions underwent T2- and T1-weighted spin-echo magnetic resonance ( MR ) imaging and fast low-angle shot two-dimensional MR imaging before , during , and after intravenous administration of three different doses of Gd-EOB-DTPA ( 12.5 , 25 , and 50 mumol per kilogram body weight ) . Gd-DTPA-enhanced imaging ( dose , 0.1 mmol per kilogram body weight ) was performed in the same patients within 1 week of Gd-EOB-DTPA imaging . RESULTS During the perfusion phase ( the 3 minutes after injection of contrast material ) , the dynamic enhancement characteristics seen after injection of 25 and 50 mumol of Gd-EOB-DTPA were similar to those seen with Gd-DTPA . At the lowest dose of Gd-EOB-DTPA ( 12.5 mumol ) , the dynamic enhancement characteristics were not comparable to those seen with Gd-DTPA . During the hepatobiliary phase ( 1.5 minutes to 4 hours after injection ) , Gd-EOB-DTPA-enhanced images yielded a dose-independent , statistically significant improvement in the detection rate of additional metastases , hepatocellular carcinomas , and hemangiomas compared with unenhanced and Gd-DTPA-enhanced images ( P < .05 ) . CONCLUSION Gd-EOB-DTPA-enhanced MR imaging enables improved detection of hepatic lesions over Gd-DTPA-enhanced MR imaging while providing comparable differential diagnostic information OBJECTIVE The purpose of this article is to prospect ively determine the sensitivity of hepatobiliary phase gadoxetate disodium-enhanced MRI combined with st and ard MRI in differentiating focal nodular hyperplasia ( FNH ) from hepatocellular adenoma ( HCA ) . SUBJECTS AND METHODS Patients suspected of having FNH or HCA larger than 2 cm underwent gadoxetate disodium-enhanced MRI . St and ard MRI was evaluated separately from the additional hepatobiliary phase by two blinded radiologists . For the largest lesion in each patient , findings were compared with histologic diagnosis . Sensitivity , positive predictive value ( PPV ) , and distinctive features were analyzed using McNemar and analysis of variance tests . RESULTS Fifty-two patients completed the study . Histologic diagnosis revealed 24 HCAs and 28 FNHs . Characterization on  st and ard MRI  was inconclusive in 40 % ( 21/52 ) and conclusive in 60 % ( 31/52 ) of lesions . The sensitivity of st and ard MRI  for HCA was 50 % ( 12/24 ) with a PPV of 100 % ( 12/12 ) . The sensitivity for FNH was 68 % ( 19/28 ) with a PPV of 95 % ( 18/19 ) . After review of hepatobiliary phase , the sensitivity for HCA improved to 96 % ( 23/24 ) with a PPV of 96 % ( 23/24 ) . The sensitivity for FNH improved to 96 % ( 27/28 ) with a PPV of 96 % ( 27/28 ) . Features with significant predictive value for diagnosis in HCA included bleeding ( p < 0.001 ) , fat ( p = 0.010 ) , and glycogen ( p = 0.024 ) . The presence of a central scar was predictive for FNH ( p < 0.001 ) . CONCLUSION This study shows high sensitivity of gadoxetate disodium-enhanced MRI when st and ard series are combined with the hepatobiliary phase for differentiation of FNH and HCA in lesions larger than 2 cm PURPOSE To assess prospect ively the efficacy and safety of postcontrast magnetic resonance ( MR ) imaging with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid ( Gd-EOB-DTPA ) compared with that of precontrast MR imaging in patients who are known to have or are suspected of having liver lesions and who are scheduled for hepatic surgery . MATERIAL S AND METHODS Investigational review board approval and written informed consent were obtained . HIPAA went into effect after data collection . A total of 172 patients were enrolled . After precontrast MR imaging , 169 patients ( 94 men , 75 women ; mean age , 61 years ; age range , 19 - 84 years )  received an intravenous bolus of 25 micromol/kg Gd-EOB-DTPA and underwent dynamic gradient-recalled-echo and delayed MR imaging 20 minutes after injection . Arterial and portal phase computed tomography ( CT ) were performed within 6 weeks of MR imaging . The st and ard of reference was surgery with intraoperative ultrasonography ( US ) and biopsy and /or pathologic evaluation of resected liver segments and /or 3-month follow-up of nonresected segments if intraoperative US was not available . Three blinded review ers and unblinded site investigators identified liver lesions on segment maps . The Wilcoxon signed rank test was used to compare differences in per-patient sensitivity of precontrast and postcontrast MR images . Adverse events were recorded , and patient monitoring and laboratory assay were performed at time of injection and up to 24 hours after contrast material administration . RESULTS At MR imaging , 316 lesions were identified in 131 patients . In 77 % ( P = .012 ) , 72 % ( P = .15 ) , and 71 % ( P = .027 ) of patients for readers 1 , 2 , and 3 , respectively , more lesions were seen at precontrast and postcontrast MR imaging combined than at precontrast MR imaging alone . Sensitivity values for blinded readings were significantly greater at postcontrast MR imaging than at precontrast MR imaging for two of three blinded readers . For all blinded readers , combined precontrast and postcontrast MR images showed no difference in sensitivity compared with helical CT scans . The use of MR imaging , however , yielded fewer patients with at least one false-positive lesion ( 37 % , 31 % , and 34 % of patients for readers 1 , 2 , and 3 , respectively ) than did helical CT ( 45 % , 36 % , and 43 % of patients for readers 1 , 2 , and 3 , respectively ) . CONCLUSION Compared with precontrast MR imaging , postcontrast MR imaging with Gd-EOB-DTPA demonstrated improved sensitivity for lesion detection in the majority of blinded readers , with no substantial adverse events Aim : To evaluate diffusion-weighted MR imaging ( DWI ) , gadoxetic acid-enhanced MR imaging and the combination of both methods in the detection , classification , and characterization of  focal liver lesions ( FLL ) . Methods : A total of 119 FLL ( 28 HCCs , 39 metastases , 15 FNHs , 11 adenomas , 13 hemangiomas , 13 cysts ) were retrospectively analyzed in 36 patients . In those patients MR imaging of the liver comprising respiratory-triggered DWI ( b values of 50 , 300 , and 600 s/mm2 ) and gadoxetic acid-enhanced MR imaging including image acquisition in the hepatocyte-selective phase ( 20 min post injection ) had been performed . Three image sets were assigned and compared : DWI only ( set A ) , gadoxetic acid-enhanced MR imaging only ( set B ) , and both modalities in combination ( set C ) . Two readers independently interpreted the images in r and om order . For each reader and image set , the area under the receiver operating characteristic curve ( Az ) and sensitivity in the detection of FLL was determined as well as the accuracy in the classification and characterization of FLL . Results : There was no significant difference between the three image sets in the detection of FLL with regards to Az . However , when only lesions with a diameter of 10 mm or less were analyzed , the Az values of set C were significantly higher than those of sets A and B for both readers . For classifying and characterizing FLL both set B and C were significantly superior to set A. Conclusion : Adding DWI to gadoxetic acid-enhanced MR imaging significantly increases the accuracy in the detection of small FLL Objectives : The aim of this prospect i ve study was to evaluate the diagnostic performance of magnetic resonance imaging ( MRI ) of the liver with the hepatocellular-specific contrast agent gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid ( Gd-EOB-DTPA ) in comparison to precontrast MRI and spiral computed tomography ( CT ) in the specific diagnosis of focal nodular hyperplasia ( FNH ) and to describe morphologic features and enhancement pattern of FNH . Material s and Methods : In 176 patients from a phase III multicenter trial , 59 confirmed FNHs were present ( 13 = histopathology ; 46 = imaging follow-up within 12 months before or 3 months after the MRI study ) . MR examination consisted of precontrast T1- and T2-w sequences , T1-weighted ( w ) dynamic sequences after bolus-injection of 0.025 mmol Gd-EOB-DTPA ( Primovist ; Bayer Schering Pharma)/kg bodyweight and T1-w sequences with fat saturation in the hepatocyte-phase after 20 minutes . The number of correctly characterized FNHs was evaluated and compared with that determined on spiral CT in an on-site reading ( clinical study ) and an off-site reading ( 3 blinded readers ) . The morphologic appearance and enhancement patterns of the FNHs were evaluated . Results : Characterization with combined pre- and post-MRI ( 88.1 % ) was superior to that achieved with biphasic-enhanced spiral CT ( 84.7 % , not significant ) and precontrast MRI ( 67.8 % , P < 0.05 ) in the clinical study and significantly superior to both precontrast MRI and spiral CT for 2 of 3 blinded readers . Complete or partial enhancement of the lesions was present in the early dynamic phase ( arterial and portovenous dynamic phase ) in 94 % and 85 % , respectively . The pattern of lesion enhancement in the early dynamic phase was mainly homogenous ( 78%–80 % ) ; the median contrast-to-noise ratio was −5.9 in T1-w precontrast images , 14.0 in the arterial phase , 2.4 in the portovenous phase , and 2.9 in the equilibrium phase . Enhancement in the hepatocyte-phase after 10 and 20 minutes was observed in 88 % and 90 % of lesions , respectively . Conclusions : Characterization of FNH provided by Gd-EOB-DTPA-enhanced MRI is superior to that provided by precontrast MRI alone or spiral CT . FNHs show very similar enhancement characteristics to those of other extracellular contrast agents in the early dynamic phase after bolus injection of Gd-EOB-DTPA , after 20 minutes in the liver-specific phase enhancement is regularly seen PURPOSE To determine whether a multiphase method with high spatiotemporal resolution ( STR ) by means of a combination of parallel imaging , pseudor and om sampling and temporal view sharing improves the capture and intensity of gadoxetate arterial phase images as well as lesion enhancement . MATERIAL S AND METHODS Thirty-seven patients were imaged with a conventional spoiled gradient echo acquisition and 48 with a high STR multiphase acquisition after the administration of gadoxetate .  Arterial phase capture , image quality , and quality of fat suppression were qualitatively grade d. Fourteen lesions in the conventional group and 28 in the high STR multiphase group were imaged , including 34 focal nodular hyperplasias . The ratio of lesion to parenchyma enhancement as well as relative hepatic artery enhancement were calculated . Chi-squared , Mann-Whitney U and student t-tests were used to compare differences . RESULTS The high STR multiphase acquisition included the arterial phase more frequently than conventional acquisitions ( P < 0.001 ) , with the arterial phase missed in 17 % ( 95 % CI of 4 - 28 % ) of patients with conventional acquisition compared with 2 % ( 95 % CI of 0 - 6 % ) with the high STR multiphase acquisition . There was no loss of image quality or degree of fat saturation . Additionally , there was increased relative intensity of the hepatic arteries ( P < 0.001 ) as well as lesion enhancement ( P = 0.01 ) . CONCLUSION The high STR multiphase acquisition result ed in more reliable gadoxetate arterial phase capture compared with a conventional acquisition while preserving image quality with robust fat saturation You are back where we put you in the previous article1 on diagnostic tests in this series on how to use the medical literature : in the library study ing an article that will guide you in interpreting ventilation-perfusion ( V/Q ) lung scans . Using the criteria in Table 1 , you have decided that the Prospect i ve Investigation of Pulmonary Diagnosis ( PIOPED ) study 2 will provide you with valid information . Just then , another OBJECTIVES The clinical management of hepatocellular adenoma ( HCA ) and focal nodular hyperplasia ( FNH ) is still 
    Output:
    
Conclusions High/iso SI on the HBP of Gd-EOB-DTPA-MRI is characteristic and a prevalent finding of FNHs and can be helpful in the management of patients with FNH.Key Points• The vast majority ( 94–97 % ) of FNHs show high/iso SI on HBP . •
High/iso SI on HBP was accurate for distinguishing FNH from hepatocellular adenoma . •
HBP of Gd-EOB-DTPA-MRI can reduce unnecessary biopsies for the diagnosis of FNHs