Small nodule detection in cirrhotic livers: evaluation with US, spiral CT, and MRI and correlation with pathologic examination of explanted liver

Clinical utility of imaging for evaluation of hepatocellular carcinoma

The hemodynamics of a hepatocellular nodule is the most important imaging parameter used to characterize various hepatocellular nodules in liver cirrhosis, because sequential changes occur in the feeding vessels and hemodynamic status during hepatocarcinogenesis. Therefore, the imaging criteria for hepatocellular carcinoma (HCC) are also usually based on vascular findings, eg, early arterial uptake followed by washout in the portal venous and equilibrium phases. Contrast-enhanced ultrasonography, dynamic multidetector-row computed tomography (MDCT), and dynamic magnetic resonance (MR) imaging with gadopentetate dimeglumine (Gd-DTPA) are useful for detecting hypervascular HCC on the basis of vascular criteria but are not as useful for hypovascular HCC. Contrast-enhanced MR imaging with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA), a hepatocyte-specific MR contrast agent, is superior to dynamic MDCT and dynamic MR imaging with Gd-DTPA in detecting both hypervascular and hypovascular HCC. Moreover, Gd-EOB-DTPA-enhanced MR imaging can display each histologically differentiated HCC as hypointense relative to the liver parenchyma. ¹⁸F-fluorodeoxyglucose positron emission tomography imaging might not be suitable for the screening and detection of HCC, given its lower diagnostic performance. However, this technique plays an important role in determining whether HCC has spread beyond the liver.

Solid liver masses: approach to management from the standpoint of a radiologist

Solid liver masses are being discovered at increasing rates due to the widespread use of medical imaging. Ultrasound, computed tomography, and magnetic resonance imaging play important and often complementary roles in detecting and diagnosing solid liver masses. Morphologic and enhancement characteristics as well as clinical history frequently allow a confident imaging diagnosis. Still, diagnosing liver masses with imaging alone remains a challenge, and masses that do not meet specific diagnostic criteria may require biopsy. Newly developed standardized terminology and imaging criteria have facilitated the imaging diagnosis of hepatocellular carcinoma (HCC) in patients with cirrhosis. Hepatobiliary-secreted MRI contrast agents have improved the ability to diagnose focal nodular hyperplasia and may also improve the detection and imaging diagnosis of HCC. These exciting new contrast agents are the subject of active investigation.

Gd-EOB-DTPA-enhanced MRI is better than MDCT in decision making of curative treatment for hepatocellular carcinoma

BACKGROUND

We assessed the change in the therapeutic decision among curative treatments after adding Gd-EOB-DTPA-enhanced MRI to triple-phase MDCT for patients with early-stage HCC.

METHODS

This study retrospectively investigated two groups: 33 pathologically confirmed HCC patients after liver transplantation in group 1; 34 HCC patients without pathology in group 2. In group 1, we simulated the therapeutic decision-making process by pretransplant MDCT and Gd-EOB-DTPA-enhanced MRI. In group 2, including the 34 early-stage HCC patients consecutively enrolled, we investigated the change of therapeutic decision after adding Gd-EOB-DTPA-enhanced MRI to MDCT.

RESULTS

In the simulation from group 1, after adding Gd-EOB-DTPA-enhanced MRI, 33.3% (11/33 patients) of treatment decisions were changed from the decision based on MDCT alone. Among 22 patients considered eligible for resection and 33 patients for radiofrequency ablation, the therapeutic decision was changed for 10 patients in the surgical group and 4 patients for the RFA group (45.5 and 12.1%). In group 2, the rate of change in the therapeutic decision after adding Gd-EOB-DTPA-enhanced MRI to MDCT was 41.2% (14/34 patients). In group 1 with explants pathology, the median diameter of HCCs not detected by MDCT but detected by Gd-EOB-DTPA-enhanced MRI was 1.15 cm (0.3-3.0 cm). The median diameter of HCCs seen only in the explanted liver was 1.0 cm (0.3-1.7 cm), and 60.7% of them were well-differentiated HCCs.

CONCLUSIONS

This study suggests that performing Gd-EOB-DTPA-enhanced MRI before deciding on curative treatment for early-stage HCC may improve the accuracy of treatment decision for early-stage HCC.

Liver transplantation and expanded Milan criteria: does it really work?

CONTEXT

Orthotopic liver transplantation is an excellent treatment approach for hepatocellular carcinoma in well-selected candidates. Nowadays some institutions tend to Expand the Milan Criteria including tumor with more than 5 cm and also associate with multiple tumors none larger than 3 cm in order to benefit more patients with the orthotopic liver transplantation.

METHODS

The data collected were based on the online database PubMED. The key words applied on the search were "expanded Milan criteria" limited to the period from 2000 to 2009. We excluded 19 papers due to: irrelevance of the subject, lack of information and incompatibility of the language (English only). We compiled patient survival and tumor recurrence free rate from 1 to 5-years in patients with hepatocellular carcinoma submitted to orthotopic liver transplantation according to expanded the Milan criteria from different centers.

RESULTS

Review compiled data from 23 articles. Fourteen different criteria were found and they are also described in detail, however the University of California - San Francisco was the most studied one among them.

CONCLUSION

Expanded the Milan criteria is a useful attempt for widening the preexistent protocol for patients with hepatocellular carcinoma in waiting-list for orthotopic liver transplantation. However there is no significant difference in patient survival rate and tumor recurrence free rate from those patients that followed the Milan criteria.

A pooled analysis of diffusion-weighted imaging in the diagnosis of hepatocellular carcinoma in chronic liver diseases

BACKGROUND AND AIM

The purpose of this study was to perform a meta-analysis of all available studies of the diagnostic performance of diffusion-weighted imaging (DWI) in the detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease.

METHODS

Databases including MEDLINE and EMBASE were searched for relevant original articles published from January 2000 to April 2012. Pooled estimation and subgroup analysis data were obtained by statistical analysis.

RESULTS

Across the nine studies (476 patients), DWI sensitivity was 81% (95%CI: 67%-90%), and specificity was 89% (95% CI: 76%-95%). Overall, positive likelihood ratio was 7.11 (95%CI: 3.50, 14.48), negative likelihood ratio was 0.21 (95%CI: 0.12-0.37), and the diagnostic odds ratio (DOR) was 33.48 (95%CI: 16.67-67.25). The area under the curve of the summary receiver operator characteristic (ROC) was 0.92 (95% CI:0.89-0.94). In studies in which both DWI and conventional contrast-enhanced magnetic resonance imaging (CE-MRI) were performed, the comparison of DWI performance with that of conventional CE-MRI suggested no major differences against these two methods (P > 0.05). DWI combined CE-MRI had higher pooled sensitivity than DWI alone (93% vs 73%) (P < 0.05).

CONCLUSION

DWI has good diagnostic performance in the detection of HCC in patients with chronic liver disease and equivalent to conventional CE-MRI. Combination of CE-MRI and DWI can improve the diagnostic accuracy of MRI. Further larger prospective studies are still needed to establish its value for detecting HCC in patients with chronic liver disease.

Biomarkers: evaluation of screening for and early diagnosis of hepatocellular carcinoma in Japan and china

Over the past few decades, the screening for and early diagnosis of hepatocellular carcinoma (HCC) has attracted attention worldwide, and especially in Asian countries such as Japan and China. Such approaches can help detecting HCC at an earlier stage when curable interventions can be offered to achieve long-term disease-free survival for patients. Biomarkers have been used to screen for and diagnose HCC in various countries. In Japan, the combined tests of des-Γ-carboxyprothrombin (DCP) and α-fetoprotein (AFP) or Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3) have been shown to achieve a high level of sensitivity and specificity. These tests have routinely been used to screen for HCC and are covered by Japan's national health insurance. Due to the routine practice of screening for HCC among high-risk patients, HCC nodules have been detected in the early stages in more than 60% of patients in Japan. In contrast, although several remarkable advances in the management of HCC have been made in China over the past few decades, most HCC patients still present with advanced-stage disease. AFP is the only serum biomarker that has widely been used to screen for and diagnose HCC in China. In recent years, several molecular biological studies have further investigated the clinical usefulness of DCP, and they have found that it may facilitate the screening for and diagnosis of HCC and assist with the assessment of HCC progression. DCP can serve as a biomarker to detect HCC in an early stage and facilitate definitive treatment. The wide implementation of DCP is expected, especially in China where 55% of HCC cases worldwide live.

Multidisciplinary management of hepatocellular carcinoma

Treatment of HCC is complicated by its highly variable biologic behavior and the frequent coexistence of chronic liver disease and cirrhosis in affected patients. While surgery remains the most frequently employed treatment modality, curative resection is only possible for a minority of patients. More often, treatment goals are palliative and draw on the expertise of a range of medical specialists. This chapter aims to place current treatment strategies within the framework of a multidisciplinary approach with special emphasis on pretreatment evaluation, staging, and the selection of an appropriate treatment strategy.

Detectability of hepatocellular carcinoma by gadoxetate disodium-enhanced hepatic MRI: tumor-by-tumor analysis in explant livers

PURPOSE

To investigate the detectability of hepatocellular carcinoma (HCC) on Gd-EOB-enhanced MR images (Gd-EOB-MRI), we performed tumor-by-tumor analysis of pathologically confirmed tumors using explants from cirrhotic patients who had undergone liver transplantation.

MATERIALS AND METHODS

We studied 11 explanted livers and classified the tumor intensity during the arterial phase (AP) and the hepatobiliary phase (HBP) as low in HBP with early enhancement (EE) in AP (A), as high in HBP with EE in AP (B), as low in HBP without EE in AP (C), as high in HBP without EE in AP (D), and as iso-intense in HBP with EE in AP (E). The diagnostic criteria for HCC were (i) pattern A and C, (ii) pattern A and E, (iii) pattern C and E, and (iv) patterns A, C, and E.

RESULTS

Of the 71 HCCs, 22 were not detected at MRI; of these, 9 were moderately differentiated and 13 were well-differentiated HCCs. The sensitivity of Gd-EOB-MRI for diagnostic criteria 1, 2, 3, and 4 was 63.4%, 52.1%, 22.5%, and 69.0%.

CONCLUSION

The maximum sensitivity of Gd-EOB-MRI for HCC was only 69.0% even when diagnostic criteria that included all previously reported HCC patterns were adopted.

Hepatocellular carcinoma in a North American population: does hepatobiliary MR imaging with Gd-EOB-DTPA improve sensitivity and confidence for diagnosis?

PURPOSE

To evaluate the value of hepatobiliary phase imaging for detection and characterization of hepatocellular carcinoma (HCC) in liver MRI with Gd-EOB-DTPA, in a North American population.

MATERIALS AND METHODS

One hundred MRI examinations performed with the intravenous injection of Gd-EOB-DTPA in patients with cirrhosis were reviewed retrospectively. Nodules were classified as HCC (n = 70), indeterminate (n = 33), or benign (n = 22). Five readers independently reviewed each examination with and without hepatobiliary phase images (HBP). Lesion conspicuity scores were compared between the two readings. Lesion detection, confidence scores, and receiver operating characteristic (ROC) analysis were compared.

RESULTS

Lesion detection was slightly improved for all lesion types with the inclusion of the HBP, and was substantially higher for small HCCs (96.0% versus 85.3%). Mean confidence scores for the diagnosis of HCC increased for HCCs overall and each size category (P < 0.001). Diagnostic performance improved with the addition of the HBP (aggregate AROC 87.7% versus 80.0%, P < 0.01), and sensitivity for characterization improved (90.9% versus 78.3%, P < 0.01) while specificity was unchanged.

CONCLUSION

Hepatobiliary phase imaging may improve small lesion detection (<1 cm) and characterization of lesions in general, in MRI of the cirrhotic liver with Gd-EOB-DTPA.

MR imaging of hypervascular lesions in the cirrhotic liver: a diagnostic dilemma

Cirrhosis is characterized by a spectrum of hepatocellular nodules that mark the progression from regenerative nodules to low- and high-grade dysplastic nodules, followed by small and large hepatocellular carcinomas (HCCs). Characterization of small nodules on the basis of imaging and histopathologic findings is complicated by an overlap in findings associated with each type of nodule, a reflection of their multistep transitions. Vascularity patterns change gradually as the nodules evolve, with an increasing shift from predominantly venous to predominantly arterial perfusion. Regenerative and low-grade dysplastic nodules demonstrate predominantly portal perfusion and contrast enhancement similar to that of surrounding parenchyma. Differentiation of high-grade dysplastic nodules and well-differentiated HCCs on the basis of dynamic imaging and histologic findings is challenging, with a high rate of false-negative results. Some small nodules that lack hypervascularity may be early HCCs. Progressed small and large HCCs usually present no diagnostic difficulty because of their characteristic findings. Although characterization of hypervascular lesions in the cirrhotic liver is difficult, it is a key step in disease management and is the radiologist's responsibility.

Hepatocellular carcinoma: detection with diffusion-weighted versus contrast-enhanced magnetic resonance imaging in pretransplant patients

This study evaluates the performance of diffusion-weighted magnetic resonance imaging (DWI) for the detection of hepatocellular carcinoma (HCC) in pre-liver transplantation patients, compared and combined with contrast-enhanced T1-weighted imaging (CET1WI), using liver explant as the standard of reference. We included 52 patients with cirrhosis (40 men, 12 women; mean age, 56 years) who underwent DWI and CET1WI within 90 days of liver transplantation. Magnetic resonance images were analyzed for HCC detection in three separate sessions by two independent observers: DWI images (DW-set), CET1WI (CE-set), and all images together (All-set). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), per-patient accuracy, and per-lesion PPV were calculated for each image set. A total of 72 HCCs were present in 33 patients at explant (mean size, 1.5 cm [range, 0.3-6.2 cm]). Per-patient sensitivity and NPV of CE-set were significantly higher than those of DW-set when using pooled data between observers (P = 0.02 and 0.03, respectively), whereas specificity, PPV, and accuracy were equivalent. Per-lesion sensitivity was significantly higher for CE-set versus DW-set (59.0% versus 43.8%; P = 0.008, pooled data from two observers). When stratified by lesion size, the difference was significant only for lesions with a size between 1 and 2 cm (42.0% for DW-set versus 74.0% for CE-set; P = 0.001). The addition of DWI to CET1WI improved sensitivity for the more experienced observer.

CONCLUSION

DWI is outperformed by CET1WI for detection of HCC, but represents a reasonable alternative to CET1WI for detection of HCC with a size above 2 cm. The addition of DWI to CET1WI slightly increases the detection rate.

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.

Can positron emission tomography with the dual tracers [11 C]acetate and [18 F]fludeoxyglucose predict microvascular invasion in hepatocellular carcinoma?

Microvascular invasion is a poor prognostic indicator of the recurrence of hepatocellular carcinoma (HCC) after surgical treatment. Positron emission tomography (PET) with [(18) F]fludeoxyglucose ([(18) F]FDG) as a tracer has been employed to predict the prognosis before surgery for various kinds of tumors, but it has not been found to be sensitive enough for HCC. Thus, [(11) C]acetate has been adopted as an additional tracer. This study was designed to evaluate the ability of dual-tracer PET ([(18) F]FDG and [(11) C]acetate) to predict microvascular invasion before liver resection or transplantation. Fifty-eight HCC patients who were preoperatively examined with whole-body dual-tracer PET were studied. Twenty-five patients were [(18) F]FDG-positive, and 56 were [(11) C]acetate-positive. The sensitivity of [(18) F]FDG in detecting primary HCC was 43%, and the sensitivity of [(11) C]acetate was 93%. Twenty-nine patients had HCC with microvascular invasion according to the final pathological examination. The sensitivity, specificity, positive predictive value, and negative predictive value of [(18) F]FDG PET in predicting microvascular invasion were 55.2%, 69%, 64%, and 60.6%, respectively; the corresponding rates for [(11) C]acetate PET were 93.1%, 0%, 48.2%, and 0%. The factors associated with HCC recurrence, which included multifocal involvement, a large tumor size, microsatellite lesions, poor HCC differentiation, and an advanced stage of disease, were analyzed and compared with positive PET results. A tumor size greater than 5 cm was significantly associated with positive [(18) F]FDG PET results; [(11) C]acetate was not associated with poor prognostic indicators. Preoperative [(18) F]FDG PET may predict microvascular invasion. The addition of [(11) C]acetate improves the overall sensitivity of PET, but it has no incremental value in predicting microvascular invasion.

Hepatocellular carcinoma in patients with chronic liver disease: a comparison of gadoxetic acid-enhanced MRI and multiphasic MDCT

AIM

To compare the diagnostic performances of gadoxetic acid-enhanced magnetic resonance imaging (MRI) and multiphasic multidetector computed tomography (MDCT) in the detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease.

MATERIALS AND METHODS

Institutional review board approval was obtained for this study and informed consent was obtained from all patients. Fifty-one patients (43 men, eight women; age range 32-80 years) with 73 HCCs underwent gadoxetic acid-enhanced MRI and multiphasic MDCT. Two readers independently analysed each image in three separate reading sessions. The alternative free-response receiver operating characteristic (AFROC) method was used to analyse the diagnostic accuracy. Positive and negative predictive values and sensitivity were evaluated.

RESULTS

A total of 73 HCCs were detected in 51 patients. Although not significant (p>0.05), the areas under the receiver operating characteristic curves were 0.877 and 0.850 for MDCT, 0.918 and 0.911 for dynamic MRI, and 0.905 and 0.918 for combined interpretation of dynamic and hepatobiliary phase MR images. Differences in sensitivity, specificity, and positive and negative predictive values between the readers were not statistically significant (p>0.05). Combined interpretation of dynamic and hepatobiliary phase MRI images was more useful than MDCT in the detection of HCC lesions ≤1cm in diameter for one reader (p=0.043).

CONCLUSION

Gadoxetic acid-enhanced MRI and MDCT show similar diagnostic performances for the detection of HCC in patients with chronic liver disease. However, the combined interpretation of dynamic and hepatobiliary phase MRI images may improve diagnostic accuracy in the detection of HCC lesions ≤1cm in diameter.

Contrast-enhanced ultrasound-guided microwave ablation for hepatocellular carcinoma inconspicuous on conventional ultrasound

OBJECTIVE

To evaluate the efficiency and feasibility of contrast-enhanced ultrasound (CEUS)-guided microwave ablation for hepatocellular carcinoma inconspicuous on conventional US.

MATERIALS AND METHODS

From March 2006 to February 2010, 107 patients (93 male, 14 female; mean age 58.9±11.0 years) with 107 hepatocellular carcinoma (HCC) nodules (mean maximum diameter 19.5±8.5 mm) inconspicuous on conventional US underwent microwave (MW) ablation under CEUS guidance in this study. US contrast agent was SonoVue (Bracco, Milan, Italy), a second-generation contrast agent. CEUS was performed first, and then MW ablation was carried out by means of CEUS guidance under unconscious intravenous anaesthesia if the tumours were displayed on CEUS.

RESULTS

105 tumours were successfully visualised on CEUS by using 1-2 times contrast agent injection and MW ablation was performed under CEUS guidance. The technical success rate was 98.13% (105/107). The number of antenna insertions for each tumour was 1.89±0.92, and the mean session of MW ablation for each tumour was 1.08±0.28. The mean duration of energy application for each tumour was 7.05±4.03 min. The follow-up time was 12-54 months (median 18 months). The technique effectiveness rate was 99.05% (104/105). The local tumour progression rate was 1.9% (2/105). There were no severe complications in any patients.

CONCLUSION

CEUS-guided MW ablation is an efficient and feasible treatment method for patients with hepatocellular carcinoma inconspicuous on conventional US.

[Evaluation of noninvasive diagnostic criteria for hepatocellular carcinoma on pretransplant MRI (2010): correlation between MR imaging features and histological features on liver specimen]

PURPOSE

To validate the 2010 diagnostic criteria from the American Association for the Study of Liver Diseases (AASLD) for hepatocellular carcinoma (HCC) on MRI using the surgical liver specimen as a gold standard.

PATIENTS AND METHODS

A total of 21 liver transplant recipients were retrospectively included. Each underwent surgery because of HCC between January 2007 and January 2008. Pre-transplant MRI was performed on a 1.5 Tesla MR unit. The T1W and T2W signal and kinetic contrast enhancement were correlated for each lesion with the surgical specimen. Lesion diameters between MRI and specimen were compared (Spearman). A multivariate model was created (R statistics software package) to predict the presence and grade of tumor differentiation (WHO, Edmonson Steiner).

RESULTS

A total of 71 nodules were detected at histology, including 54 HCC (mean size: 25.3mm) compared to 68 on MRI. There was moderate agreement (r=0.58, P<0.001) between the maximum lesion diameters measured on MRI and at histology. Wash-out on MRI provided an accuracy of 75 % for the detection of HCC (sensitivity=75 %, specificity=76 %). Adding T2W hyperintensity to the AASLD criteria increased the sensitivity of MRI from 70.3 % to 77.7 % for the diagnosis of HCC and from 67.6 % to 79 % for nodules less than 20mm in diameter, without affecting specificity. On multivariate analysis, wash out as a single variable was significantly associated with a diagnosis of HCC (P<0.01, odds ratio 12.0, CI 95 % [2.6-55.5]). T1W hyperintensity (P=0.04, odds ratio 5.4) and loss of signal on opposed-phase images (P=0.02, odds ratio 9.2) were predictive of good differentiation.

CONCLUSION

On MRI, the AASLD criteria or presence of wash out within a liver nodule in patients with underlying chronic hepatocellular disease are suggestive of tumoral transformation. The addition of T2W hyperintensity to the AASLD criteria increases the detection of HCC, especially nodules smaller than 20mm.

Microwave ablation assisted by a computerised tomography-ultrasonography fusion imaging system for liver lesions: an ex vivo experimental study

PURPOSE

To investigate the feasibility and validity of real-time guidance using a fusion imaging system that combines ultrasonography (US) and computerised tomography (CT) information in the targeting and subsequent microwave ablation of a liver target inconspicuous on US.

MATERIALS AND METHODS

The study was an experimental ex vivo study in calf livers with internal targets, simulating a focal liver lesion, focused on the accuracy of real-time US using a multimodality fusion imaging system in combination with 15 gauge (G) microwave antennae. US image and pre-procedural CT image were fused by the external markers registration procedure. Microwave antennae were inserted into the liver to ablate the target assisted by the CT-US fusion imaging system. Finally, a post-procedural CT with needles in situ and multiplanar reconstructions were performed to compare with pre-procedural CT information in order to calculate the accuracy of positioning (distance between the needle tip and the target).

RESULTS

Eight insertions were planned and eight ablations were performed in four calf livers. The calf livers were undertaken successfully on external markers registration procedure. The mean registration error in the four livers was 2.1 ± 0.1 mm, 2.8 ± 0.1 mm, 3.4 ± 0.1 mm and 2.3 ± 0.1 mm, respectively. The accuracy of the matched US-CT images was very satisfactory in the fact that it was found there was a mean discrepancy of 1.63 ± 1.06 mm.

CONCLUSION

Real-time registration and fusion of pre-procedural CT volume images with intraprocedural US is feasible and accurate for microwave (MW) ablation in experimental setting. Further studies are warranted to validate the system under clinical conditions.

Outcomes of patients with hepatocellular carcinoma referred for percutaneous radiofrequency ablation at a tertiary center: analysis focused on the feasibility with the use of ultrasonography guidance

PURPOSE

This study aimed to assess the feasibility of performing ultrasonography (US)-guided percutaneous radiofrequency (RF) ablation on patients with hepatocellular carcinoma (HCC) and identify causes of procedure infeasibility and its predisposing conditions.

MATERIALS AND METHODS

A total of 109 consecutive patients (male:female=86:23; mean 59.9 years) with 136 HCCs (mean 1.8 cm) who had been referred for planning US were analyzed. We evaluated overall procedure feasibility as well as specific factors relating to feasibility, including inability to visualize the tumor with US and factors relating to safety of the procedure.

RESULTS

The use of percutaneous RF ablation was concluded as infeasible for 45 tumors (33.1%). Reasons for infeasibility included tumor invisibility (n=32), a high risk of collateral thermal injury (n=5), absence of a safe electrode path (n=5) and a combination of factors (n=3). Among 136 tumors, 36(26.5%) were invisible due to isoechogenicity (n=16), indiscrimination from surrounding cirrhotic nodules (n=10) or an unfavorable location (n=10). Tumor invisibility was significantly attributed to a small tumor size (P<0.001, risk ratio=0.823) and the presence of macronodular cirrhosis (P=0.006, risk ratio=4.117). Seven patients with invisible tumors were treated with RF ablation after follow-up (n=4) or with use of adjacent structures as landmarks (n=3). Ultimately, 65 of 109 patients were treated with percutaneous RF ablation.

CONCLUSIONS

US-guided percutaneous RF ablation for HCC was feasible in about two-thirds of candidates. Infeasibility was mostly due to inability to visualize the tumor with US, especially for patients with smaller tumor and macronodular cirrhosis.

Microwave ablation assisted by a real-time virtual navigation system for hepatocellular carcinoma undetectable by conventional ultrasonography

OBJECTIVES

To evaluate the efficiency and feasibility of microwave (MW) ablation assisted by a real-time virtual navigation system for hepatocellular carcinoma (HCC) undetectable by conventional ultrasonography.

METHODS

18 patients with 18 HCC nodules (undetectable on conventional US but detectable by intravenous contrast-enhanced CT or MRI) were enrolled in this study. Before MW ablation, US images and MRI or CT images were synchronized using the internal markers at the best timing of the inspiration. Thereafter, MW ablation was performed under real-time virtual navigation system guidance. Therapeutic efficacy was assessed by the result of contrast-enhanced imagings after the treatment.

RESULTS

The target HCC nodules could be detected with fusion images in all patients. The time required for image fusion was 8-30 min (mean, 13.3 ± 5.7 min). 17 nodules were successfully ablated according to the contrast enhanced imagings 1 month after ablation. The technique effectiveness rate was 94.44% (17/18). The follow-up time was 3-12 months (median, 6 months) in our study. No severe complications occurred. No local recurrence was observed in any patients.

CONCLUSIONS

MW ablation assisted by a real-time virtual navigation system is a feasible and efficient treatment of patients with HCC undetectable by conventional ultrasonography.

Vascular invasion in hepatocellular carcinoma: is there a correlation with MRI?

OBJECTIVE

Hepatocellular carcinoma (HCC) is one of the commonest malignancies worldwide. Prognosis is predicted by size at diagnosis, vascular invasion and tumour proliferation markers. This study investigates if MRI features of histologically proven HCCs correlate with vascular invasion.

METHODS

Between 2006 and 2008, 18 consecutive patients, with a total of 27 HCCs, had comprehensive MRI studies performed at our institution within a median of 36 days of histology sampling. Each lesion was evaluated independently on MRI by 3 radiologists (blinded to both the radiology and histopathology reports) using a 5-point confidence scale for 23 specific imaging features. The mean of the rating scores across readers was calculated to determine interobserver consistency. The most consistent features were then used to examine the value of features in predicting vascular invasion, using a χ(2 )test for trend, having eliminated those features without sufficient variability.

RESULTS

22 of the 23 imaging features showed sufficient variability across lesions. None of these significantly correlated with the presence of vascular invasion, although a trend was identified with the presence of washout in the portal venous phase on MRI and the median size of lesions, which was greater with vascular invasion.

CONCLUSION

This study suggests that no single MRI feature accurately predicts the presence of vascular invasion in HCCs, although a trend was seen with the presence of washout in the portal venous phase post gadolinium. Larger prospective studies are required to investigate this further.

Accuracy of hepatocellular carcinoma detection on multidetector CT in a transplant liver population with explant liver correlation

AIM

To evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) for hepatocellular carcinoma (HCC) in cirrhotic patients undergoing liver transplantation. Secondary aims were to examine the effect of radiologist experience and lesion size on diagnostic accuracy.

MATERIALS AND METHODS

Thirty-nine patients (72% male with a mean age of 56.5 years) underwent liver transplantation following preoperative triple-phase MDCT examination of the liver. MDCT examinations were retrospectively independently reviewed by three radiologists for the presence and location of suspected HCCs, with the diagnostic confidence recorded using a five-point confidence scale. MDCT examinations were compared with explant specimens for histopathological correlation.

RESULTS

Histopathological results demonstrated 46 HCCs in 29 of the 39 patients. Analysis demonstrated a sensitivity of 65-75% and specificity of 47-88% for detection of HCC lesions. The sensitivity dropped to 48-57% for lesions of size ≤20mm. As the diagnostic confidence increased, there was a further decrease in the sensitivity (4-26%). The radiologist with the greatest number of years experience was found to have a significantly higher accuracy of detection of HCC lesions compared with the least experienced radiologist.

CONCLUSION

Larger lesion size of HCC and greater number of years experience of the radiologist resulted in significantly higher accuracy of HCC lesion detection. The overall sensitivity and specificity results for MDCT detection of HCC are comparable to previous helical CT imaging.

Long-term experience with liver transplantation for hepatocellular carcinoma

BACKGROUND

The effect of the model for end-stage liver disease (MELD) system on the post-transplant survival of patients with hepatocellular carcinoma (HCC) has not been fully elucidated. Our objective is to review the results of liver transplantation (LT) for HCC at the Massachusetts General Hospital over a period of 12 years, with special emphasis on the effect of the MELD system.

METHODS

A retrospective review of 73 patients who underwent liver transplantation for HCC between 1995 and 2007. Outcome measures included demographics, tumor stage at explant, patient survival, and tumor recurrence.

RESULTS

On pathologic review of the explanted liver, 12.3% of patients were classified as stage I; 42.5% as stage II, 21.9% as stage III, and 23.3% as stage IV. The overall actual survival rate was 85% at 1 year, 82% at 3 years, 73% at 5 years, and 66% at 10 years. Overall tumor recurrence was 11%. Survival rates were higher after the MELD system (5 year survival 60% before MELD vs. 85% after MELD). Recurrence decreased from 21% to 7.5%.

CONCLUSION

We showed improved survival for HCC after LT over the last 12 years, and especially improved survival and decreased recurrence in the time since the implementation of the MELD system.

[Radiological diagnosis of hepatocellular carcinoma in 2010]

The aim of diagnosis imaging is to detect hepatocellular carcinoma at an early stage, when a curative treatment is available. Biopsy is no longer required prior to treatment, and diagnosis of hepatocellular carcinoma is heavily dependent of imaging characteristics. Therefore, the purpose of this article is to describe the typical features of small (<20mm) and larger hepatocellular carcinomas with noninvasive diagnostic criteria, including ultrasound, computed tomography and MRI. Advances in these imaging modalities have greatly improved the detection of small hepatic nodules on liver cirrhosis, including the different steps of carcinogenesis, from regenerative to dysplastic nodules, and we emphasize the difficulties of radiological differentiation of precancerous lesions and small hepatocellular carcinomas.

Irreversible electroporation in the liver: contrast-enhanced inversion-recovery MR imaging approaches to differentiate reversibly electroporated penumbra from irreversibly electroporated ablation zones

PURPOSE

To evaluate the use of contrast material-enhanced magnetic resonance (MR) imaging with conventional T1-weighted gradient-recalled echo (GRE) and inversion-recovery (IR)-prepared GRE methods to quantitatively measure the size of irreversible electroporation (IRE) ablation zones in the liver in a rat model.

MATERIALS AND METHODS

All studies were approved by the institutional animal care and use committee and were performed in accordance with institutional guidelines. Seventeen adult male Sprague-Dawley rats were divided into four groups. Rats in groups 1-3 (n = 15 total) underwent IRE performed by using different IRE parameters after gadopentetate dimeglumine administration. Rats in group 4 (n = 2) underwent IRE ablation without prior gadopentetate dimeglumine injection to serve as control animals. MR imaging measurements (with conventional T1-weighted GRE and IR-prepared GRE methods) were performed 2 hours after IRE to predict the IRE ablation zones, which were correlated with pathology-confirmed necrosis areas 24 hours after IRE by using the Spearman correlation coefficient. Bland-Altman plots were also generated to investigate the agreement between MR imaging-measured ablation zones and reference standard histologic measurements of corresponding ablation zones.

RESULTS

The necrotic areas measured on the pathology images were well correlated with the hyperintense regions measured on T1-weighted GRE images (r = 0.891, P < .001) and normal tissue-nulled IR images (r = 0.874, P < .001); pathology measurements were also well correlated with the smaller hyperintense regions measured on those IR images with inversion times specifically selected to null signal from the peripheral penumbra surrounding the ablation zone (r = 0.939, P < .001). Bland-Altman plots indicated that these penumbra-nulled IR images provided more accurate predictions of IRE ablation zones, with T1-weighted GRE measurements tending to overestimate ablation zone sizes.

CONCLUSION

Contrast-enhanced MR imaging permits accurate depiction of ablated tissue zones after IRE procedures. IR-prepared contrast-enhanced MR imaging can be used to quantitatively measure IRE ablation zones in the liver.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100645/-/DC1.

Added value of 80 kVp images to averaged 120 kVp images in the detection of hepatocellular carcinomas in liver transplantation candidates using dual-source dual-energy MDCT: results of JAFROC analysis

BACKGROUND

To assess the added value of 80 kVp images to weighted average 120 kVp images for detecting hepatocellular carcinomas (HCCs) using dual-source, dual-energy MDCT.

MATERIALS AND METHODS

Forty-one HCCs in 42 patients who underwent liver transplantation (LT) were included. All patients underwent quadruple-phase CT using a 64-row dual-source, dual-energy MDCT with 80 kVp and 140 kVp. For 120 kVp, a linear blending ratio of 0.3 was chosen. Interval reviews for both simulated 120 kVp images without and with pure 80 kVp data were performed independently by two radiologists. They detected HCCs using a 4-point confidence scale. Tumor-to-liver contrast-to-noise ratio (CNR) was calculated and compared between the 80 kVp and simulated 120 kVp images. The additional diagnostic value of 80 kVp images was evaluated by jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis.

RESULTS

There were 41 HCCs on pathology and 37 of the 41 HCCs were depicted on CT scan. The mean CNR of the 37 HCCs in late arterial and portal-phase images was significantly better in the 80 kVp images than in 120 kVp images. The average JAFROC figure of merit, however, was not significantly improved when 80 kVp was added. Furthermore, the number of false-positives was significantly increased in reader 1 when adding 80kVp data.

CONCLUSION

The addition of 80 kVp CT images to simulated 120 kVp images did not significantly improve the detection of HCCs despite of the significantly better CNR of 80 kVp images.

Chronic hepatitis B and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world and the third leading cause of cancer-related deaths. More than 80% of HCC cases are from the Asian and African continents, and more than 50% of cases are from mainland China. Approximately 350 million to 400 million persons are chronically infected with hepatitis B virus (HBV), and this virus is the most common cause of HCC worldwide. It is estimated that more than 50% of liver cancers worldwide are attributable to HBV and up to 89% of HBV-related HCC are from developing countries. Recently, increasing trends in HCC incidence have been reported from several Western countries, including France, Australia, and the United States.

CT and MRI of hepatocellular carcinoma: an update

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and one of the few malignancies with an increasing incidence in the USA. Imaging plays a crucial role in early detection, accurate staging and planning management strategies. Contrast material-enhanced MRI or computed tomography (CT) are the best imaging techniques currently available for the noninvasive diagnosis of HCC. The diagnosis of HCC is strongly dependent on hemodynamic features (arterial hypervascularity and washout in the venous phase) on dynamic imaging, and biopsy is no longer recommended for tumors with classical imaging features prior to treatment. The major challenge for radiologists in imaging cirrhosis is the characterization of hypervascular nodules smaller than 2 cm, which often have nonspecific imaging characteristics. In this review, we discuss the role of CT and MRI in the diagnosis and staging of HCC. The strengths and current limitations of these imaging modalities are highlighted.

Outcomes of follow-up CT for small (5-10-mm) arterially enhancing nodules in the liver and risk factors for developing hepatocellular carcinoma in a surveillance population

OBJECTIVE

To evaluate the outcomes of small (5-10 mm), arterially enhancing nodules (SAENs) shown exclusively at the hepatic arterial phase of CT in a hepatocellular carcinoma (HCC) surveillance population and to determine risk factors for developing HCC.

METHODS

The study population included 112 patients (male:female = 100:12; aged 36-92 years) with 175 SAENs who were at risk of HCC. We evaluated serial changes during follow-up (1.4-41.8 months, mean 35.7 months) and analysed the initial CT findings of SAENs and the accompanying lesions to elucidate the risk factors for HCC development.

RESULTS

Of 175 SAENs, 101(57.7%) disappeared and 34(19.4%) persisted. Forty SAENs (22.9%) became HCC in 33 patients (29.5%). Presence of HCC treatment history (p = 0.005, risk ratio = 7.429), a larger size of SAEN (p = 0.003, risk ratio = 1.630), presence of coexistent HCC (p = 0.021, risk ratio = 3.777) and absence of coexistent typical arterioportal shunts (p = 0.003, risk ratio = 4.459) turned out to be independently significant risk factors for future development of HCC.

CONCLUSION

SAENs were frequently seen in an HCC surveillance population and have a 22.9% probability of becoming HCC on a per-lesion basis. Risk increased particularly when the lesion was associated with a previous or concurrent HCC, a large size or found without a coexistent typical arterioportal shunt.

Pretreatment assessment of hepatocellular carcinoma: expert consensus statement

Staging of hepatocellular carcinoma (HCC) is complex and relies on multiple factors including tumor extent and hepatic function. No single staging system is applicable to all patients with HCC. The staging of the American Joint Committee on Cancer / International Union for Cancer Control should be used to predict outcome following resection or liver transplantation. The Barcelona Clinic Liver Cancer scheme is appropriate in patients with advanced HCC not candidate for surgery. Dual phase computed tomography or magnetic resonance imaging can be used for pretreatment assessment of tumor extent but the accuracy of these methods remains poor to characterize < 1 cm lesions. Assessment of tumor response should not rely only on tumor size and new imaging methods are available to evaluate response to therapy in HCC patients. Liver volumetry is part of the preoperative assessment of patients with HCC candidate for resection as it reflects liver function. Preoperative portal vein embolization is indicated in patients with small future liver remnant (≤ 20% in normal liver; ≤ 40% in fibrotic or cirrhotic liver). Tumor size is not a contraindication to liver resection. Liver resection can be proposed in selected patients with multifocal HCC. Besides tumor extent, surgical resection of HCC may be performed in selected patients with chronic liver disease.

Pearls and pitfalls in hepatic ultrasonography

Ultrasonography is often the initial imaging study in patients who present with right upper quadrant abdominal complaints. However, due to its intrinsic technical limitations, ultrasonography generally has a lower sensitivity than contrast-enhanced computed tomography or magnetic resonance imaging in detecting hepatic lesions. In this review, we describe several subtle sonographic signs that suggest the presence of an otherwise inconspicuous focal liver lesion, including disease in the pleural space or the lung parenchyma, refractive edge shadows, distorted or absent venous landmarks, abnormal Doppler patterns, and venous thrombosis. When encountered, these features should trigger careful evaluation of the adjacent areas for abnormalities and may warrant further studies with computed tomography, magnetic resonance imaging, or positron emission tomography. We also summarize common sonographic findings of diffuse liver diseases, including fatty infiltration and cirrhosis.

Targeted sonography for small hepatocellular carcinoma discovered by CT or MRI: factors affecting sonographic detection

OBJECTIVE

The purpose of this study was to evaluate the detection rate of targeted sonography for small (<or= 3 cm) hepatocellular carcinomas (HCCs) primarily discovered by CT or MRI and to assess factors affecting lesion visibility on targeted sonography.

SUBJECTS AND METHODS

Between October 2005 and April 2008, targeted sonography for small (<or= 3 cm) HCC was prospectively performed in cirrhotic patients. Targeted sonography was performed by a radiologist with knowledge of the size and location of the HCC. Invisible HCCs were compared with visible HCCs with regard to size, distance from the diaphragm, segmental location, subcapsular location, cause of liver cirrhosis, presence or absence of previous treatment, Child-Pugh class, and serum alpha-fetoprotein by using univariate and multivariate analyses.

RESULTS

A total of 93 consecutive patients (65 men and 28 women; mean age, 59 years) with 93 HCCs (mean size +/- SD, 1.8 +/- 0.6 cm) were enrolled in this study. Of those, 73 (78.5%) HCCs were visible on targeted sonography. The detection rate was 36.4% (4/11) for HCC <or= 1.0 cm, 77.6% (38/49) for HCC between 1.1 and 2.0 cm, and 93.9% (31/33) for HCC between 2.1 and 3.0 cm. In both univariate and multivariate analyses, the size of the tumor and distance between the tumor and the diaphragm were statistically significant factors affecting sonographic visibility.

CONCLUSION

The overall detection rate for small (<or= 3 cm) HCC on targeted sonography was 78.5%. Small size and subphrenic location of the tumor were two independent predictors of sonographic invisibility.

Asian Pacific Association for the Study of the Liver consensus recommendations on hepatocellular carcinoma

INTRODUCTION

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party on the management of hepatocellular carcinoma (HCC) in December 2008 to develop consensus recommendations.

METHODS

The working party consisted of expert hepatologist, hepatobiliary surgeon, radiologist, and oncologist from Asian-Pacific region, who were requested to make drafts prior to the consensus meeting held at Bali, Indonesia on 4 December 2008. The quality of existing evidence and strength of recommendations were ranked from 1 (highest) to 5 (lowest) and from A (strongest) to D (weakest), respectively, according to the Oxford system of evidence-based approach for developing the consensus statements.

RESULTS

Participants of the consensus meeting assessed the quality of cited studies and assigned grades to the recommendation statements. Finalized recommendations were presented at the fourth APASL single topic conference on viral-related HCC at Bali, Indonesia and approved by the participants of the conference.

Asian Pacific Association for the Study of the Liver consensus recommendations on hepatocellular carcinoma

INTRODUCTION

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party on the management of hepatocellular carcinoma (HCC) in December 2008 to develop consensus recommendations.

METHODS

The working party consisted of expert hepatologist, hepatobiliary surgeon, radiologist, and oncologist from Asian-Pacific region, who were requested to make drafts prior to the consensus meeting held at Bali, Indonesia on 4 December 2008. The quality of existing evidence and strength of recommendations were ranked from 1 (highest) to 5 (lowest) and from A (strongest) to D (weakest), respectively, according to the Oxford system of evidence-based approach for developing the consensus statements.

RESULTS

Participants of the consensus meeting assessed the quality of cited studies and assigned grades to the recommendation statements. Finalized recommendations were presented at the fourth APASL single topic conference on viral-related HCC at Bali, Indonesia and approved by the participants of the conference.

Hepatocellular carcinoma: review of current treatment with a focus on targeted molecular therapies

The treatment of hepatocellular carcinoma (HCC) remains a challenge, with 1- and 3-year survival rates of 20% and 5%, respectively, and a median survival of 8 months. However, a better understanding of the pathogenesis of HCC, and advances in targeted molecular therapies provide physicians treating this disease with new hope. The treatment of HCC is multidisciplinary, requiring surgeons, hepatologists, interventional radiologists and oncologists. Thus, there is enormous potential to combine various treatment modalities to improve survival for patients. This review will describe what is currently known about the molecular pathogenesis of HCC, explore current and future treatments based on these pathways, and describe how these new therapies fit into existing approaches to HCC treatment.

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.

Surveillance and diagnosis of hepatocellular carcinoma in patients with cirrhosis

Early identification of hepatocellular carcinoma (HCC) is more frequent because of surveillance programs for HCC worldwide. The optimal strategy of surveillance in cirrhosis is a current topical issue. In terms of diagnosis, recent advances in non-invasive imaging technology, including various techniques of harmonic ultrasound, new ultrasound contrast agents, multi-slice helical computed tomography and rapid high quality magnetic resonance, have all improved the accuracy of diagnosis. Consequently the role of liver biopsy in diagnosis of HCC has declined. The imaging diagnosis relies on the hallmark of arterial hypervascularity with portal venous washout. However, with recent advances in genomics and proteomics a great number of potential serum and tissue markers have been identified and are being developed as new candidate markers for both diagnosis and prognosis of hepatocellular carcinoma, and may increase the need for liver biopsy.

Needle track seeding following percutaneous procedures for hepatocellular carcinoma

Neoplastic seeding may arise after diagnostic or therapeutic percutaneous procedures for hepatocellular carcinoma. The true incidence of seeding with hepatocellular carcinoma is difficult to assess precisely, but a significant risk of seeding exists and is greater when performing diagnostic biopsy as compared to therapeutic percutaneous procedures [radiofrequency ablation, radiofrequency ablation (RFA); percutaneous ethanol injection, Percutaneous ethanol injection (PEI)]. Whenever liver transplantation is feasible, diagnostic needle biopsies should be avoided, but RFA and PEI are often needed as "bridge" treatments. The role of adjuvant treatments in reducing the incidence of seeding following RFA or PEI requires further evaluation.

Small (Radiol Med 2009;114:1239-66. [PMID: 19697104 DOI: 10.1007/s11547-009-0439-x]

PURPOSE

We prospectively compared gadoliniumenhanced magnetic resonance imaging (dynamic MRI), superparamagnetic iron oxide (SPIO) (ferucarbotran) MRI and multidetector-row computed tomography (MDCT) and the combination of dynamic MRI plus MDCT vs. dynamic MRI plus SPIO-MRI (double-contrast MRI: DC-MRI) for the detection of small (

MATERIALS AND METHODS

Sixty-three patients with liver cirrhosis and suspicious nodules detected during ultrasound (US) surveillance underwent DC-MRI in the same imaging session and MDCT within 15 days. The final diagnosis was established at pathology on the explanted liver (n=10), resection (n=6) and biopsy (n=38) specimens or at 2-years' follow-up (n=9).

RESULTS

One hundred and twenty-three nodules were detected: 87 were confirmed HCCs in 54 patients. The accuracy of SPIO-MRI and dynamic MRI were similar, both being superior to MDCT. Dynamic MRI demonstrated the highest sensitivity (83.9%; p<0.001). especially for lesions <1 cm (90.6%) - coupled with a lower specificity (36.1%) than SPIO-MRI, particularly in subcentimeter lesions (28.6%). SPIO-MRI demonstrated the highest sensitivity for nodules >1 cm and the highest specificity (83.3%) superior to dynamic MRI (p<0.0001). In the per-lesion analysis, SPIO-MRI demonstrated a positive predictive value higher than dynamic MRI (p=0.0059) and than both the combinations dynamic MRI/MDCT and DC-MRI (p=0.0021 and p=0.0087, respectively). DC-MRI showed the highest sensitivity (97.7%) and accuracy (78.9%), detecting hypovascular and atypical HCCs >1 cm. Furthermore its per-patient negative predictive value was the highest (100%), and significantly higher than all the other methods.

CONCLUSIONS

DC-MRI is the most sensitive and accurate method and can be confidently used as a single-step procedure for the detection of small HCCs, with the exception of lesions <1 cm.

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MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Carcinoma, Hepatocellular/diagnosis
• Carcinoma, Hepatocellular/diagnostic imaging
• Contrast Media
• Dextrans
• Female
• Ferrosoferric Oxide
• Follow-Up Studies
• Gadolinium DTPA
• Humans
• Liver Cirrhosis/diagnosis
• Liver Cirrhosis/diagnostic imaging
• Liver Neoplasms/diagnosis
• Liver Neoplasms/diagnostic imaging
• Magnetic Resonance Imaging
• Magnetite Nanoparticles
• Male
• Middle Aged
• Predictive Value of Tests
• Prospective Studies
• Sensitivity and Specificity
• Tomography, X-Ray Computed

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Affiliation(s)

R Golfieri Radiologia Malpighi, Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, Università di Bologna, Via Albertoni 15, 40138, Bologna, Italy.
E Marini
A Bazzocchi
F Fusco
F Trevisani
C Sama
G Mazzella
S Cavuto
F Piscaglia
L Bolondi

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Diagnostic performance of multidetector row computed tomography, superparamagnetic iron oxide-enhanced magnetic resonance imaging, and dual-contrast magnetic resonance imaging in predicting the appropriateness of a transplant recipient based on milan criteria: correlation with histopathological findings

PURPOSE

To retrospectively evaluate the diagnostic performance of multidetector row CT (MDCT), superparamagnetic iron oxide (SPIO)-enhanced MRI (S-MRI), and dual-contrast MRI (DC-MRI) in predicting the appropriateness of recipients with hepatocellular carcinoma (HCC) for liver transplantation (LT), based on Milan criteria.

MATERIALS AND METHODS

This retrospective study received Institutional Review Board approval. Requirement for patient informed consent was waived. During a 3-year period, 80 patients who underwent LT were enrolled in this study. However, 2 patients in whom >10 HCCs were present were excluded from the analysis of detection performance of imaging modalities for HCC. MDCT and DC-MRI examinations with the sequential use of SPIO and gadolinium were performed in all patients. Interval readings for MDCT, S-MRI, and DC-MRI were performed. Two radiologists independently recorded confidence levels using a 4- and 5-point scale for the presence of HCC and for the appropriateness regarding LT, respectively. Image interpretation was compared with histopathological results on a lesion-by-lesion basis. Diagnostic performance of the 3 imaging techniques was compared using jackknife alternative free-response receiver operating characteristic and ROC analyses.

RESULTS

Eighty-two HCCs were detected in 38 of 78 patients. Twenty-seven HCCs were larger than 2 cm in diameter and 55 HCCs were smaller than 2 cm in diameter. Among 80 patients included for the assessment of eligibility for LT, 69 recipients were categorized as appropriate and the remaining 11 patients were found to be inappropriate for LT based on Milan criteria. In terms of detecting HCCs, the reader-averaged figure of merit was highest for DC-MRI (0.764), followed by S-MRI (0.702) and MDCT (0.672). The use of DC-MRI was significantly better than the use of the other 2 modalities specifically for HCCs smaller than 2 cm in diameter (P < 0.001) although not for those larger than or equal to 2 cm (P = 0.125-1). The AZ value for predicting the appropriateness for LT was highest with the use of S-MRI (0.841), followed by the use of DC-MRI (0.830) and the use of MDCT (0.790). However, significant differences were not seen for the predictions determined by both radiologists (P = 0.384-1). This result might be because of the small number of patients who had a critical number of HCCs (ie, 2 approximately 4 HCCs).

CONCLUSION

DC-MRI showed significantly better diagnostic performance in transplantation candidates for the detection of HCCs, particularly small HCCs, than both MDCT and S-MRI. However, for assessing the appropriateness of a transplantation recipient based on Milan criteria, MDCT, S-MRI, and DC-MRI showed comparable diagnostic accuracy without a statistical difference.

Current management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common cancers worldwide, continues to increase in incidence in several regions around the world and is associated with poor overall survival. Patients with cirrhosis are at the highest risk and are candidates for surveillance. Wide implementation of surveillance programs and improvement in noninvasive radiologic techniques has led to tumor diagnosis at earlier stages. Surgical options that include resection and liver transplantation offer the best chance of successful outcomes. Locoregional therapies, such as radiofrequency ablation and chemoembolization, provide effective local control in those with acceptable hepatic function. A multikinase inhibitor, sorafenib, is the first molecular targeted oral therapy that has recently been shown to provide a survival benefit in HCC in select patients.

Modern diagnosis and management of hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is rising, and the number of patients with HCC is expected to more than double over the next 1 to 2 decades. HCC meets the criteria for establishment of a surveillance program. Patients with cirrhosis, regardless of the cause, are at the highest risk for developing HCC and this is the population in which surveillance should be performed. (Alpha-fetoprotein and hepatic ultrasonography are the currently recommended surveillance tests. If a surveillance test is abnormal, there is a need for a recall test for diagnostic evaluation of HCC. Triple-phase imaging is recommended for evaluation at recall, with MRI being more sensitive and specific. Novel genetic markers can improve the histologic diagnosis of early HCC. The Barcelona staging classification is the best system for determining the prognosis of patients and it is linked to an evidence-based treatment algorithm. Resection, transplantation, and percutaneous ablation are considered curative interventions and are currently applied to about 30% of all patients with HCC.

Hepatocellular carcinoma in patients with cirrhosis: qualitative comparison of gadobenate dimeglumine-enhanced MR imaging and multiphasic 64-section CT

PURPOSE

To prospectively investigate whether combined interpretation of dynamic and hepatobiliary phase magnetic resonance (MR) images can improve the accuracy of gadobenate dimeglumine-enhanced MR imaging in the detection of hepatocellular carcinoma (HCC) compared with either dynamic MR or multiphasic multidetector computed tomographic (CT) images alone.

MATERIALS AND METHODS

Institutional review board approval and informed patient consent were obtained. Fifty-two patients (39 men, 13 women; mean age, 68 years; range, 38-81 years) suspected of having HCC underwent gadobenate dimeglumine-enhanced MR imaging and multiphasic 64-section multidetector CT. Images were qualitatively analyzed independently by three observers in three separate reading sessions. The alternating free-response receiver operating characteristic (AFROC) method was used to analyze the results. Differences in sensitivity and positive predictive values were calculated at a statistical significance of P < .05.

RESULTS

A total of 67 HCCs were detected in 36 patients. The mean area under the AFROC curve (A(z)) was significantly higher for either the combined interpretation of dynamic and hepatobiliary phase MR images (A(z) = 0.95) or dynamic MR images alone (0.91) than for CT images (0.77) (P = .01 for both comparisons). The mean sensitivity of combined interpretation of MR images (0.72) was significantly higher than those of dynamic MR images alone (0.63) and multidetector CT images (0.61) (P = .008 and .001, respectively). The mean positive predictive value was not significantly different among the three imaging sets.

CONCLUSION

The combined interpretation of dynamic and hepatobiliary phase MR images improves diagnostic accuracy of gadobenate dimeglumine-enhanced MR imaging for the detection of HCC compared with either dynamic MR or multiphasic multidetector CT images alone.

Does the echogenicity of focal liver lesions on baseline gray-scale ultrasound interfere with the diagnostic performance of contrast-enhanced ultrasound?

The objective was to evaluate whether the echogenicity of focal liver lesions (FLLs) on baseline gray-scale ultrasound (US) interferes with the diagnostic performance of contrast-enhanced US (CEUS) for small FLLs. Three-hundred and eighty-eight patients were examined by real-time CEUS using a sulfur hexafluoride-filled microbubble contrast agent. The images of 114 hyperechoic lesions, 30 isoechoic lesions and 244 hypoechoic lesions were reviewed by two blinded independent readers. A five-point confidence level was used to discriminate malignant from benign lesions, and specific diagnoses were made. The diagnostic performances were evaluated by receiver-operating characteristic (ROC) analysis. The diagnostic performances of CEUS on hyperechoic lesions in terms of the areas (Az) under the ROC curve were 0.987 (reader 1) and 0.981 (reader 2), and were 0.987 (reader 1) and 0.984 (reader 2) for iso- and hypoechoic lesions, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87.0-95.9%, 93.1-100%, 88.6-100%, 70.0-97.1% and 90.0-95.1%, respectively. The echogenicity of FLLs on baseline gray-scale US does not appear to interfere with the diagnostic ability of CEUS for small FLLs.