Usefulness of Combining Sequentially Acquired Gadobenate Dimeglumine-Enhanced Magnetic Resonance Imaging and Resovist-Enhanced Magnetic Resonance Imaging for the Detection of Hepatocellular Carcinoma

Computed tomography for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease

BACKGROUND

Hepatocellular carcinoma occurs mostly in people with chronic liver disease and ranks sixth in terms of global incidence of cancer, and fourth in terms of cancer deaths. In clinical practice, computed tomography (CT) is used as a second-line diagnostic imaging modality to confirm the presence of focal liver lesions suspected as hepatocellular carcinoma on prior diagnostic test such as abdominal ultrasound or alpha-foetoprotein, or both, either in surveillance programmes or in clinical settings. According to current guidelines, a single contrast-enhanced imaging study CT or magnetic resonance imaging (MRI) showing typical hallmarks of hepatocellular carcinoma in people with cirrhosis is valid to diagnose hepatocellular carcinoma. However, a significant number of hepatocellular carcinomas do not show typical hallmarks on imaging modalities, and hepatocellular carcinoma is, therefore, missed. There is no clear evidence of the benefit of surveillance programmes in terms of overall survival: the conflicting results can be a consequence of inaccurate detection, ineffective treatment, or both. Assessing the diagnostic accuracy of CT may clarify whether the absence of benefit could be related to underdiagnosis. Furthermore, an assessment of the accuracy of CT in people with chronic liver disease, who are not included in surveillance programmes is needed for either ruling out or diagnosing hepatocellular carcinoma.

OBJECTIVES

Primary: to assess the diagnostic accuracy of multidetector, multiphasic contrast-enhanced CT for the diagnosis of hepatocellular carcinoma of any size and at any stage in adults with chronic liver disease, either in a surveillance programme or in a clinical setting. Secondary: to assess the diagnostic accuracy of CT for the diagnosis of resectable hepatocellular carcinoma in adults with chronic liver disease.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Trials Register, Cochrane Hepato-Biliary Diagnostic-Test-Accuracy Studies Register, the Cochrane Library, MEDLINE, Embase, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index - Science until 4 May 2021. We applied no language or document-type restrictions.

SELECTION CRITERIA

Studies assessing the diagnostic accuracy of CT for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, with cross-sectional designs, using one of the acceptable reference standards, such as pathology of the explanted liver and histology of resected or biopsied focal liver lesion with at least a six-month follow-up.

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened studies, extracted data, and assessed the risk of bias and applicability concerns, using the QUADAS-2 checklist. We presented the results of sensitivity and specificity, using paired forest plots, and tabulated the results. We used a hierarchical meta-analysis model where appropriate. We presented uncertainty of the accuracy estimates using 95% confidence intervals (CIs). We double-checked all data extractions and analyses.

MAIN RESULTS

We included 21 studies, with a total of 3101 participants. We judged all studies to be at high risk of bias in at least one domain because most studies used different reference standards, often inappropriate to exclude the presence of the target condition, and the time-interval between the index test and the reference standard was rarely defined. Regarding applicability in the patient selection domain, we judged 14% (3/21) of studies to be at low concern and 86% (18/21) of studies to be at high concern owing to characteristics of the participants who were on waiting lists for orthotopic liver transplantation. CT for hepatocellular carcinoma of any size and stage: sensitivity 77.5% (95% CI 70.9% to 82.9%) and specificity 91.3% (95% CI 86.5% to 94.5%) (21 studies, 3101 participants; low-certainty evidence). CT for resectable hepatocellular carcinoma: sensitivity 71.4% (95% CI 60.3% to 80.4%) and specificity 92.0% (95% CI 86.3% to 95.5%) (10 studies, 1854 participants; low-certainty evidence). In the three studies at low concern for applicability (861 participants), we found sensitivity 76.9% (95% CI 50.8% to 91.5%) and specificity 89.2% (95% CI 57.0% to 98.1%). The observed heterogeneity in the results remains mostly unexplained. The sensitivity analyses, which included only studies with clearly prespecified positivity criteria and only studies in which the reference standard results were interpreted without knowledge of the results of the index test, showed no variation in the results.

AUTHORS' CONCLUSIONS

In the clinical pathway for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, CT has roles as a confirmatory test for hepatocellular carcinoma lesions, and for staging assessment. We found that using CT in detecting hepatocellular carcinoma of any size and stage, 22.5% of people with hepatocellular carcinoma would be missed, and 8.7% of people without hepatocellular carcinoma would be unnecessarily treated. For resectable hepatocellular carcinoma, we found that 28.6% of people with resectable hepatocellular carcinoma would improperly not be resected, while 8% of people without hepatocellular carcinoma would undergo inappropriate surgery. The uncertainty resulting from the high risk of bias in the included studies and concerns regarding their applicability limit our ability to confidently draw conclusions based on our results.

Imaging of HCC-Current State of the Art

Early diagnosis of hepatocellular carcinoma (HCC) is crucial for optimizing treatment outcome. Ongoing advances are being made in imaging of HCC regarding detection, grading, staging, and also treatment monitoring. This review gives an overview of the current international guidelines for diagnosing HCC and their discrepancies as well as critically summarizes the role of magnetic resonance imaging (MRI) and computed tomography (CT) techniques for imaging in HCC. The diagnostic performance of MRI with nonspecific and hepatobililiary contrast agents and the role of functional imaging with diffusion-weighted imaging will be discussed. On the other hand, CT as a fast, cheap and easily accessible imaging modality plays a major role in the clinical routine work-up of HCC. Technical advances in CT, such as dual energy CT and volume perfusion CT, are currently being explored for improving detection, characterization and staging of HCC with promising results. Cone beam CT can provide a three-dimensional analysis of the liver with tumor and vessel characterization comparable to cross-sectional imaging so that this technique is gaining an increasing role in the peri-procedural imaging of HCC treated with interventional techniques.

Characterization of hepatocellular carcinoma (HCC) lesions using a novel CT-based volume perfusion (VPCT) technique

OBJECTIVE

To characterize hepatocellular carcinoma (HCC) in terms of perfusion parameters using volume perfusion CT (VPCT) and two different calculation methods, compare their results, look for interobserver agreement of measurements and correlation between tumor arterialization and lesion size.

MATERIAL AND METHODS

This study was part of a prospective monitoring study in patients with HCC undergoing TACE, which was approved by the local Institutional Review Board. 79 HCC-patients (mean age, 64.7) with liver cirrhosis were enrolled. VPCT was performed for 40s covering the involved liver (80 kV, 100/120 mAs) using 64 mm × 0.6 mm collimation, 26 consecutive volume measurements, 50 mL iodinated contrast IV and 5 mL/s flow rate. Mean/maximum blood flow (BF; ml/100mL/min), blood volume (BV) and k-trans were determined both with the maximum slope+Patlak vs. deconvolution method. Additionally, the portal venous liver perfusion (PVP), the arterial liver perfusion (ALP) and the hepatic perfusion index (HPI) were determined for each tumor including size measurements. Interobserver agreement for all perfusion parameters was calculated using intraclass correlation coefficients (ICC).

RESULTS

The max. slope+Patlak method yielded: BFmean/max=37.8/57 mL/100g-tissue/', BVmean/max=9.8/11.1 mL/100g-tissue, k-trans-mean/max=34.4/44.5 mL/100g-tissue/'. For the deconvolution method BFmean/max, BVmean/max and, k-trans-mean/max were 68.3/106.1 mL/100g-tissue/', 12.6/15.5 mL/100g-tissue and 24/33.8 mL/100g-tissue/'. Mean ALP, PVP, HPI and size were 53.7 mL/100g-tissue/', 2.4 mL/100g-tissue/', 96.4 and 3.5 cm, respectively. Interobserver agreement measured with intraclass coefficient correlation (ICC) was very good for all perfusion parameters (≥ 0.99). Best correlation between calculation methods was achieved for measurements of BF, while BV and k-trans values were less correlated. There was no relationship between HPI and lesion size.

CONCLUSION

VPCT can measure tumor volume perfusion non-invasively and enables quantification of the degree of HCC arterialization. Results are dependent on the technique used with best inter-method correlation for BF. Tumor HPI did not proved size-dependent.

C-arm CT during hepatic arteriography tumour-to-liver contrast: intraindividual comparison of three different contrast media application protocols

OBJECTIVE

To compare tumour-to-liver contrast (TLC) of C-arm CT during hepatic arteriography (CACTHA) acquired using three protocols in patients with HCC.

METHODS

This prospective study was IRB approved and informed consent was obtained from each patient. Twenty-nine patients (mean age, 68 ± 7 years; 27 men) with 55 HCCs (mean diameter, 2.6 ± 1.5 cm) underwent three different CACTHA protocols in random order before chemoembolisation. Contrast medium (100 mg iodine/ml) was injected into the common hepatic artery (flow rate 4 ml/s). The imaging delay for the start of the CACTHA examination was 4 s (protocol A), 8 s (protocol B) and 12 s (protocol C) (total amount of injected contrast medium: 48 ml, 64 ml, 80 ml). TLC was measured by placing regions of interest (ROIs) in the HCC and liver parenchyma. Mixed model ANOVAs and Bonferroni corrected post hoc tests were used for statistical analysis.

RESULTS

Mean values for TLC were 132 ± 3.3 HU, 186 ± 5.8 HU and 168 ± 2.8 HU for protocols A, B and C. Protocol B provided significantly higher TLC than protocols A and C (p < 0.001).

CONCLUSION

TLC was significantly higher using an imaging delay of 8 s compared with a delay of 4 or 12 s.

Which is the best MRI marker of malignancy for atypical cirrhotic nodules: hypointensity in hepatobiliary phase alone or combined with other features? Classification after Gd-EOB-DTPA administration

PURPOSE

To investigate whether the malignancy of atypical nodules in cirrhosis can be identified at gadoxetic-acid-disodium(Gd-EOB-DTPA)-MRI by their hypointensity in the hepatobiliary(HB)-phase alone or combined with any other MR imaging features.

MATERIALS AND METHODS

One hundred eleven atypical nodules detected in 77 consecutive Gd-EOB-DTPA-MRIs were divided, based on arterial-phase behavior, into: Class I, isovascular (n = 82), and Class II, hypervascular without portal/delayed washout (n = 29). The two classes were further grouped based on HB-phase intensity (A/B/C hypo/iso/hyperintensity). Portal/venous/equilibrium-phase behavior and T2w features were also collected. Histology was the gold standard. Per-nodule sensitivity, specificity, negative and positive predictive values (NPV/PPV), and diagnostic accuracy were calculated for HB-phase hypointensity alone, and combined with vascular patterns and T2w hyperintensity.

RESULTS

Histology detected 60 benign and 51 malignant/premalignant nodules [10 overt hepatocellular carcinomas (HCCs) and 41 high-grade dysplastic nodules (HGDN)/early HCC]. Class IA contained 31 (94%) malignancies, IB one (3%), and IC only benign lesions. Class IIA had 100% malignancies, IIB three (37.5%) and IIC only two (28.5%). HB-phase hypointensity alone (Classes I-IIA) had 88% sensitivity, 91% NPV, and 93% diagnostic accuracy, superior (P < 0.05, P < 0.006, and P < 0.05, respectively) to any other MR imaging feature alone or combined.

CONCLUSION

In atypical cirrhotic nodules, HB-phase hypointensity by itself is the strongest marker of malignancy.

Ultrasonography, computed tomography and magnetic resonance imaging of hepatocellular carcinoma: toward improved treatment decisions

Detection, characterization, staging, and treatment monitoring are major roles in imaging diagnosis in liver cancers. Contrast-enhanced ultrasonography (CEUS) using microbubble contrast agents has expanded the role of US in the detection and diagnosis of liver nodules in patients at high risk of hepatocellular carcinoma (HCC). CEUS provides an accurate differentiation between benign and malignant liver nodules, which is critical for adequate management of HCC and is also useful for guidance of percutaneous local therapy of HCC and postprocedure monitoring of the therapeutic response. The technology of multidetector-row computed tomography (MDCT) has increased spatial and temporal resolutions of computed tomography (CT). It has made possible a more precise evaluation of the hemodynamics of liver tumor, and the diagnostic accuracy of dynamic MDCT has improved. Perfusion CT can measure tissue perfusion parameters quantitatively and can assess segmental hepatic function. Dynamic MDCT with high spatial and temporal resolution enables us to reconstruct 3- and 4-dimensional imaging, which is very useful for pretreatment evaluation. Dual-energy CT makes possible the differentiation of materials and tissues in images obtained based on the differences in iodine and water densities. Monochromatic images, which can be reconstructed by dual-energy CT data, provide some improvement in contrast and show a higher contrast-to-noise ratio for hypervascular HCCs. Dynamic magnetic resonance imaging with fast imaging sequence of 3-dimensional Fourier transformation T(1)-weighted gradient echo and nonspecific contrast medium can show high detection sensitivity of hypervascular HCC. However, the hepatic tissue-specific contrast medium, gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid, has become an essential contrast medium for liver imaging because of its higher diagnostic ability. It may replace CT during hepatic arteriography and during arterioportography.

Detection of liver malignancy with gadoxetic acid-enhanced MRI: is addition of diffusion-weighted MRI beneficial?

AIM

To determine the additive value of diffusion-weighted MRI (DWI) to gadoxetic acid-enhanced MRI for the detection of hepatic metastases and hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Thirty-five patients with 38 liver metastases and 18 HCCs were included in this study. Ten patients also had hemangiomas (n = 3) or cysts (n = 8). Liver MRI consisted of pre-contrast and gadoxetic acid-enhanced 3D T1-weighted MRIs (arterial, portal, 2-min delay, 20 min hepatocyte-selective phases), a post-contrast T2-weighted image, and post-contrast DWI (b values: 0, 50, 600 s/mm²). Two observers independently analyzed the gadoxetic acid-enhanced MRI with and without DWI. The diagnostic accuracy and sensitivity for the detection of liver lesions were evaluated using receiver operating characteristic analysis.

RESULTS

Although there were no significant differences in diagnostic accuracy for detecting metastases and HCCs between the gadoxetic acid set alone and the combined DWI and gadoxetic acid set for both observers (mean Az, 0.974 vs 0.987), we found the sensitivity for detecting metastases to be significantly higher with the combined images (97.4%) than with the gadoxetic acid set alone (89.5%) for observer 1 (p = 0.008). Three and two metastases for each observer were clearly verified by adding DWI to gadoxetic acid-enhanced MRI. However, sensitivities for both image sets were equivalent in detecting HCCs.

CONCLUSION

The addition of DWI to gadoxetic acid-enhanced MRI has the potential to increase sensitivity for the detection of liver metastases. However, for detecting HCC, we found no additive value of DWI to gadoxetic acid-enhanced MRI.

Diagnostic efficacy of gadoxetic acid-enhanced MRI in the detection of hepatocellular carcinomas: comparison with gadopentetate dimeglumine

This study compared the efficacy of gadoxetic acid-enhanced MRI and gadopentetate dimeglumine-enhanced MRI in the detection of small hepatocellular carcinoma (HCC). Both MRI techniques were performed on 43 patients with a total of 59 HCCs (size range, 0.5-2.0 cm), with a mean interval between the two MRI studies of 3 days (range, 2-7 days). Two observers reviewed both data sets in consensus. Diagnostic accuracy and sensitivity were evaluated using the alternative-free response receiver operator characteristic (ROC) method. The gadoxetic acid set showed a trend toward increased area under the ROC curve (Az value = 0.958) compared with the gadopentetate dimeglumine set (Az value = 0.927), but the difference was not significant (p = 0.362). The sensitivity of the gadoxetic acid set (n = 51, 86.4%) was significantly higher than that of the gadopentetate dimeglumine set (n = 38, 64.4%) (p = 0.0001). Gadoxetic acid-enhanced MRI is a more sensitive diagnostic tool for detection of HCC than gadopentetate dimeglumine-enhanced MRI.

Added value of gadoxetic acid-enhanced hepatobiliary phase MR imaging in the diagnosis of hepatocellular carcinoma

PURPOSE

To determine the added value of hepatobiliary phase images in gadoxetic acid-enhanced magnetic resonance (MR) imaging in the evaluation of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Institutional review board approved this retrospective study and waived the informed consent. Fifty-nine patients with 84 HCCs underwent gadoxetic acid-enhanced MR examinations that included 20-minute delayed hepatobiliary phase imaging. MR imaging was performed with a 1.5-T system in 19 patients and a 3.0-T system in 40 patients. A total of 113 hepatic nodules were documented for analysis. Three radiologists independently reviewed two sets of MR images: set 1, unenhanced (T1- and T2-weighted) and gadoxetic acid-enhanced dynamic images; set 2, hepatobiliary phase images and unenhanced and gadoxetic acid-enhanced dynamic images. For each observer, the diagnostic accuracy was compared by using the area under the alternative free-response receiver operating characteristic curve (A(z)). Sensitivity and specificity were also calculated and compared between the two sets.

RESULTS

For all observers, A(z) values were higher with the addition of the hepatobiliary phase. The observer who had the least experience in abdominal imaging (2 years) demonstrated significant improvement in A(z), from 0.895 in set 1 to 0.951 in set 2 (P = .049). Sensitivity increased with the addition of hepatobiliary phase images but did not reach statistical significance. Nine HCCs (10.7%) in six patients (10.1%) were seen only on hepatobiliary phase images.

CONCLUSION

Hepatobiliary phase images obtained after gadoxetic acid-enhanced dynamic MR imaging may improve diagnosis of HCC and assist in surgical planning.

MRI versus 64-row MDCT for diagnosis of hepatocellular carcinoma

AIM: To compare the diagnostic capability of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) for the detection of hepatocellular carcinoma (HCC) tumour nodules and their effect on patient management.

METHODS: A total of 28 patients (25 male, 3 female, mean age 67 ± 10.8 years) with biopsy-proven HCC were investigated with 64-row MDCT (slice 3 mm native, arterial and portal-venous phase, 120 mL Iomeprol, 4 mL/s, delay by bolus trigger) and MRI (T1fs fl2d TE/TR 2.72/129 ms, T2tse TE/TR 102/4000 ms, 5-phase dynamic contrast-enhanced T1fs fl3d TE/TR 1.56/4.6, Gadolinium-DTPA, slice 4 mm). Consensus reading of both modalities was used as reference. Tumour nodules were analyzed with respect to number, size, and location.

RESULTS: In total, 162 tumour nodules were detected by consensus reading. MRI detected significantly more tumour nodules (159 vs 123, P < 0.001) compared to MDCT, with the best sensitivity for early arterial phase MRI. False-negative CT findings included nodules ≤ 5 mm ( n = 5), ≤ 10 mm ( n = 17), ≤ 15 mm ( n = 12 ), ≤ 20 mm ( n = 4 ), and 1 nodule > 20 mm. MRI missed 2 nodules ≤ 10 mm and 1 nodule ≤ 15 mm. On MRI, nodule diameters were greater than on CT (29.2 ± 25.1 mm, range 5-140 mm vs 24.1 ± 22.7 mm, range 4-129 mm, P < 0.005). In 2 patients, MDCT showed only unilobar tumour spread, whereas MRI revealed additional nodules in the contralateral lobe. Detection of these nodules could have changed the therapeutic strategy.

CONCLUSION: Contrast-enhanced MRI is superior to 64-row MDCT for the detection of HCC nodules. Patients should be allocated to interventional or operative treatment according to a dedicated MRI-protocol.

Role of diffusion-weighted magnetic resonance imaging in the differential diagnosis of focal hepatic lesions

AIM: To evaluate the utility of diffusion-weighted imaging (DWI) in screening and differential diagnosis of benign and malignant focal hepatic lesions.

METHODS: Magnetic resonance imaging (MRI) examinations were performed using the Signa Excite Xl Twin Speed 1.5T system (GE Healthcare, Milwaukee, WI, USA). Seventy patients who had undergone MRI of the liver [29 hepatocellular carcinomas (HCC), four cholangiocarcinomas, 34 metastatic liver cancers, 10 hemangiomas, and eight cysts] between April 2004 and August 2008 were retrospectively evaluated. Visualization of lesions, relative contrast ratio (RCR), and apparent diffusion coefficient (ADC) were compared between benign and malignant lesions on DWI. Superparamagnetic iron oxide (SPIO) was administered to 59 patients, and RCR was compared pre- and post-administration.

RESULTS: DWI showed higher contrast between malignant lesions (especially in multiple small metastatic cancers) and surrounding liver parenchyma than did contrast-enhanced computed tomography. ADCs (mean ± SD × 10^-3 mm²/s) were significantly lower (P < 0.05) in malignant lesions (HCC: 1.31 ± 0.28 and liver metastasis: 1.11 ± 0.22) and were significantly higher in benign lesions (hemangioma: 1.84 ± 0.37 and cyst: 2.61 ± 0.45) than in the surrounding hepatic tissues. RCR between malignant lesions and surrounding hepatic tissues significantly improved after SPIO administration, but RCRs in benign lesions were not improved.

CONCLUSION: DWI is a simple and sensitive method for screening focal hepatic lesions and is useful for differential diagnosis.

Focal liver lesions: detection and characterization at double-contrast liver MR Imaging with ferucarbotran and gadobutrol versus single-contrast liver MR imaging

PURPOSE

To retrospectively compare, in a multiobserver study, double-contrast-material (sequential administration of ferucarbotran and gadobutrol) magnetic resonance (MR) imaging with single-contrast-material ferucarbotran-enhanced and dynamic postferucarbotran gadobutrol-enhanced MR imaging for the detection and characterization of benign and malignant focal liver lesions.

MATERIALS AND METHODS

This study was institutional review board approved, and the requirement for informed patient consent was waived. Eighty-nine patients with a total of 128 focal liver lesions underwent double-contrast liver MR imaging (nonenhanced, ferucarbotran-enhanced, and dynamic postferucarbotran gadobutrol-enhanced MR imaging performed during one session). Four readers independently reviewed the data sets during three reading sessions focused on focal liver lesion detection and characterization: In session 1, the nonenhanced and dynamic postferucarbotran gadobutrol-enhanced images obtained at double-contrast MR imaging were analyzed. In session 2, the nonenhanced and ferucarbotran-enhanced images were analyzed. In session 3, all MR images were analyzed together. The diagnostic performance of each MR technique and each reader was evaluated by using receiver operating characteristic (ROC) analysis; differences between postferucarbotran gadobutrol-enhanced, ferucarbotran-enhanced, and double-contrast MR imaging were assessed at Wilcoxon signed rank testing; and interreader agreement was assessed at Cohen kappa analysis. Histopathologic confirmation or an unchanged clinical course or MR finding was the reference standard.

RESULTS

The four readers' detection of the benign and malignant lesions was not significantly different (P > or = .11) between the three MR techniques. The benign and malignant focal liver lesions were differentiated with significantly higher confidence (P < or = .01) on the double-contrast (area under ROC curve [A(z)] = 0.988) and ferucarbotran-enhanced (A(z) = 0.985) MR images than on the dynamic gadobutrol-enhanced images (A(z) = 0.963). Accuracy in the diagnosis of hepatocellular carcinoma (HCC) was highest (P = .02) and confidence in the final diagnosis of HCC (P = .001) or metastasis (P = .049) was significantly higher with double-contrast imaging.

CONCLUSION

In select cases, double-contrast MR imaging can improve diagnostic accuracy and increase confidence in characterizing focal liver lesions as HCC or metastasis.

Added value of breathhold diffusion-weighted MRI in detection of small hepatocellular carcinoma lesions compared with dynamic contrast-enhanced MRI alone using receiver operating characteristic curve analysis

PURPOSE

To evaluate the added value of single-breathhold diffusion-weighted MRI (DWI) in detection of small hepatocellular carcinoma (HCC) lesions (< or =2 cm) in patients with chronic liver disease, by comparing the detection sensitivity of combined DWI/conventional dynamic contrast-enhanced (DCE)-MRI to that of conventional DCE-MRI alone.

MATERIALS AND METHODS

A total of 37 patients with chronic liver diseases underwent abdominal MRI at 1.5T, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and 2D conventional DCE. For each patient study, axial DWI was performed with a single-shot echo-planar imaging (EPI) sequence using a modified sensitivity-encoding (mSENSE) technique with b-value of 500 seconds/mm(2). A total of 20-24 slices were obtained during a 15-17-second breathhold. Two observers independently interpreted the combined DWI/conventional DCE-MRI images and the conventional DCE-MRI images alone in random order. For all small HCC lesions, the diagnostic performance using each imaging set was evaluated by receiver operating characteristic (ROC) curve analysis. Sensitivity and positive predictive values were also calculated and analyzed.

RESULTS

A total of 47 small HCCs were confirmed as final result. The area under the ROC curve (Az) of combined DWI/conventional DCE-MRI images (observer 1, 0.922; observer 2, 0.918) were statistically higher than those of conventional DCE-MRI alone (observer 1, 0.809; observer 2, 0.778) for all small HCC lesions (P < 0.01). The lesion detection sensitivities using the combined technique for both observers were significantly higher than those using conventional DCE-MRI alone (P < 0.01). The sensitivity values for two observers using the combined technique were 97.87% and those using conventional DCE-MRI alone were 85.11% to 82.98%. The positive predictive values for two observers using the combined imaging technique (97.87%) were slightly higher than those using conventional DCE-MRI alone (92.86-93.02%), but there was no significant difference between the two imaging sets.

CONCLUSION

Combined use of breathhold DWI with conventional DCE-MRI helped to provide higher sensitivities than conventional DCE-MRI alone in the detection of small HCC lesions in patients with chronic liver disease.

Detection of small hepatocellular carcinoma: comparison of conventional gadolinium-enhanced MRI with gadolinium-enhanced MRI after the administration of ferucarbotran

We compared the diagnostic efficacy of gadolinium (Gd)-enhanced MRI with that of Gd-enhanced MRI after administration of ferucarbotran for revealing small hypervascular hepatocellular carcinomas (HCCs). 24 patients with 34 HCCs (ranging in size from 0.6-2.0 cm) underwent Gd-enhanced three-dimensional dynamic MRI followed, after an interval of 5-11 days (mean, 7 days), by Gd-enhanced three-dimensional dynamic MRI after administration of ferucarbotran. The two Gd-enhanced arterial-phase MRI scans were compared quantitatively by measuring the tumour-liver contrast-to-noise ratio (CNR) and qualitatively by evaluating the tumour-liver contrast using matched-pairs analysis. The tumour-liver CNR with Gd-enhanced arterial-phase imaging after ferucarbotran (250.3 +/- 103.7) was higher than that with Gd-enhanced arterial-phase imaging (221.1 +/- 96.1) (p < 0.001). Matched-pairs analysis indicated that, for three lesions, the relative tumour-liver contrast was slightly better with Gd-enhanced arterial-phase imaging after ferucarbotran than with conventional Gd-enhanced arterial-phase imaging; however, in the case of the remaining 31 lesions, the two images were equivalent. We concluded that, although Gd-enhanced arterial-phase imaging after ferucarbotran results in better tumour-liver CNR than Gd-enhanced arterial-phase imaging, the ability of the two techniques to reveal small hypervascular HCCs is the same.