Diagnostic performance of a minimized protocol of non-contrast MRI for hepatocellular carcinoma surveillance

Evaluation of Hepatocellular Carcinoma Surveillance with Contrast-enhanced MRI in a High-Risk Western European Cohort

AIM

To investigate the utilization of MRI using a MRI liver protocol with extracellular contrast-enhanced series for hepatocellular carcinoma (HCC) surveillance in high-risk patients.

METHODS

Consecutive high-risk patients of a western European cohort who underwent repeated liver MRI for HCC screening were included. Lesions were registered according to the Liver Reporting & Data System (LIRADS) 2018. HCC was staged as very early stage HCC (BCLC stage 0) and more advanced stages of HCC (BCLC stage A-D). Differences in time interval between MRI's for BCLC stage 0 and stage A-D were calculated with the Mann-Whitney U test. The HCC cumulative incidence at one-, three- and five years was calculated with the Kaplan Meier estimator.

RESULTS

From 2010 to 2019 a total of 240 patients were included (71% male; median age: 57 years; IQR: 50-64 years) with 1350 MRI's. Most patients (83 %) had cirrhosis with hepatitis C as the most common underlying cause. Patients underwent on average four MRI's (IQR: 3-7). Forty-two patients (17.5%) developed HCC (52 HCC lesions: 43 LIRADS-5, eight LIRADS-4, and one LIRADS-TIV). Eighteen patients (43%) had BCLC stage 0 HCC with a significant shorter screening time interval (10 months; IQR: 6-21) compared to patients with BCLC stage A-D (21 months; IQR: 10-32) (p = 0.03). Thirty seven percent of patients with a LIRADS-3 lesion (n=43) showed HCC development within twelve months (median: 7.4 months). One, three- and five-year HCC cumulative incidence in cirrhotic patients was 1%, 10% and 17%, respectively.

CONCLUSION

High-risk patients who underwent surveillance with contrast-enhanced MRI developed HCC in 17.5 % during a follow up period of over 4 years median. Very early stage HCC was seen in compensated cirrhosis after a median time interval of 10 months. Later stages of HCC were related to prolonged screening time interval (median 21 months).

Non-contrast abbreviated MRI for the detection of hepatocellular carcinoma in patients with Liver Imaging Reporting and Data System LR-3 and LR-4 observations in MRI

BACKGROUND AND AIMS

With ultrasound sensitivity limited in hepatocellular carcinoma (HCC) surveillance and few prospective studies on non-contrast abbreviated MRI (NC-AMRI), this study aimed to assess its diagnostic performance in detecting HCC.

METHODS

This prospective study involved cirrhotic patients with contrast-enhanced MRI (CE-MRI) Liver Imaging Reporting and Data System (LI-RADS) LR-3 and LR-4 observations detected during HCC surveillance. Patients underwent average 3 complete CE-MRI rounds at 3-6 months interval, with approximately 12-month follow-up. NC-AMRI included diffusion-weighted (DWI), T2-weighted imaging (T2WI), and T1-weighted imaging (T1WI). NC-AMRI protocol images were analysed for diagnostic performance, with subgroup analyses. CE-MRI and NC-AMRI images were independently reviewed by 2 experienced radiologists, with inter-reader agreement assessed with Kappa coefficient. The reference standard was the American Association for the Study of Liver Diseases-defined presence of arterial hypervascularity and washout during the portal-venous or delayed phases on CE-MRI.

RESULTS

In 166 CE-MRI follow-ups of 63 patients (median age: 63 years; 60.3% male, 39.7% female), 12 patients developed HCC, with average size of 19.6 mm. The NC-AMRI (DWI + T2WI + T1WI) showed 91.7% sensitivity (95%CI, 61.5-99.8) and 91.6% specificity (95%CI, 86.0-95.4), area under receiver operating characteristic 0.92 (95%CI, 0.83-1.00). Across different Body Mass Index categories, lesion size, Child-Turcotte-Pugh classes, Albumin-Bilirubin (ALBI) grades, and Model for End-Stage Liver Disease classes, sensitivity remained consistent. However, specificity differed significantly between ALBI grade 1 and 2 (86.7% vs. 98.4%, P = .010), and between viral and non-viral cirrhosis (93.8% vs. 80.8%, P = .010).

CONCLUSIONS

NC-AMRI proved clinically feasible, and exhibits high diagnostic performance in HCC detection.

ADVANCES IN KNOWLEDGE

This study highlights efficacy of NC-AMRI in detecting HCC among cirrhotic patients with LR-3 and LR-4 observations, representing significant progress in HCC surveillance.

MRI for hepatocellular carcinoma and the role of abbreviated MRI for surveillance of hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) constitutes the majority of liver cancers and significantly impacts global cancer mortality. While ultrasound (US) with or without alpha-fetoprotein is the mainstay for HCC surveillance, its limitations highlight the necessity for more effective surveillance tools. Therefore, this review explores evolving imaging modalities and abbreviated magnetic resonance imaging (MRI) (AMRI) protocols as promising alternatives, addressing challenges in HCC surveillance.

AREAS COVERED

This comprehensive review delves into the evaluation and challenges of HCC surveillance tools, focusing on non-contrast abbreviated MRI (NC-AMRI) and contrast-enhanced abbreviated MRI protocols. It covers the implementation of AMRI for HCC surveillance, patient preferences, adherence, and strategies for optimizing cost-effectiveness. Additionally, the article provides insights into prospects for HCC surveillance by summarizing meta-analyses, prospective studies, and ongoing clinical trials evaluating AMRI protocols.

EXPERT OPINION

The opinions underscore the transformative impact of AMRI on HCC surveillance, especially in overcoming US limitations. Promising results from NC-AMRI protocols indicate its potential for high-risk patient surveillance, though prospective studies in true surveillance settings are essential for validation. Future research should prioritize risk-stratified AMRI protocols and address cost-effectiveness for broader clinical implementation, alongside comparative analyses with US for optimal surveillance strategies.

Abbreviated MRI for Hepatocellular Carcinoma Surveillance - A Systematic Review and Meta-analysis

BACKGROUND

Given the limited sensitivity of ultrasound in hepatocellular carcinoma (HCC) surveillance, this systematic review and meta-analysis were aimed to assess the diagnostic performance of non-contrast abbreviated MRI (NC-aMRI) compared to contrast-enhanced abbreviated MRI (CE-aMRI) for HCC surveillance, offering evidence-based guidance for clinical decision-making.

METHODS

A comprehensive search was conducted across five databases, identifying studies on aMRI for HCC surveillance. The pooled sensitivity and specificity were estimated using a random effects model. Subgroup analyses and meta-regression were performed by study location, proportion of patients with cirrhosis and HCC, and underlying liver diseases.

RESULTS

The meta-analysis included 27 studies (2009-2023), distributed between Western (n = 14) and Eastern (n = 13) countries. The pooled sensitivity and specificity (95%CI, I2) were 86% (83-88%, 63%) and 92% (90%-94%, 74%). The NC-aMRI protocols reported in 21 studies exhibited 83% (79-87%, 63%) sensitivity and 91% (88-93%, 67%) specificity, while the 15 studies on CE-aMRI protocols displayed 88% (84-91%, 64%) sensitivity and 94% (90-96%, 78%) specificity, with no statistically significant differences in sensitivity (p = 0.078) or specificity (p = 0.157). Subgroup analysis in NC-aMRI studies showed significant differences in sensitivity for high-prevalent chronic hepatitis B (87% vs. 78%, p = 0.003) and studies done in eastern countries (86% vs. 76%, p = 0.018). Additionally, specificity showed significant differences for high-prevalent chronic hepatitis C (94% vs. 90%, p = 0.009), with meta-regression identifying major sources of study heterogeneity as the inclusion of a majority of patients with chronic hepatitis B (p = 0.008) and the geographic regions where studies were conducted (p = 0.030).

CONCLUSION

Surveillance aMRI protocols exhibit satisfactory performance for detecting HCC. NC-aMRI may be used effectively for HCC surveillance, especially in chronic hepatitis B prevalent settings.

Feasibility of the application of deep learning-reconstructed ultra-fast respiratory-triggered T2-weighted imaging at 3 T in liver imaging

OBJECTIVE

The evaluate the feasibility of a novel deep learning-reconstructed ultra-fast respiratory-triggered T2WI sequence (DL-RT-T2WI) In liver imaging, compared with respiratory-triggered Arms-T2WI (Arms-RT-T2WI) and respiratory-triggered FSE-T2WI (FSE-RT-T2WI) sequences.

METHODS

71 patients with liver lesions underwent 3-T MRI and were prospectively enrolled. Two readers independently analyzed images acquired with DL-RT-T2WI, Arms-RT-T2WI, and FSE-RT-T2WI. The qualitative evaluation indicators, including overall image quality (OIQ), sharpness, noise, artifacts, lesion detectability (LC), lesion characterization (LD), cardiacmotion-related signal loss (CSL), and diagnostic confidence (DC), were evaluated in two readers, and further statistically compared using paired Wilcoxon rank-sum test among three sequences.

RESULTS

176 lesions were detected in DL-RT-T2W and Arms-RT-T2WI, and 175 were detected in FSE-RT-T2WI. The acquisition time of DL-RT-T2WI was improved by 4.8-7.9 folds compared to the other two sequences. The OIQ was scored highest for DL-RT-T2WI (R1, 4.61 ± 0.52 and R2, 4.62 ± 0.49), was significantly superior to Arms-RT-T2WI (R1, 4.30 ± 0.66 and R2, 4.34 ± 0.69) and FSE-RT-T2WI (R1, 3.65 ± 1.08 and R2, 3.75 ± 1.01). Artifacts and sharpness scored highest for DL-RT-T2WI, followed by Arms-RT-T2WI, and were lowest for FSE-RT-T2WI in both two readers. Noise and CSL for DL-RT-T2WI scored similar to Arms-RT-T2WI (P > 0.05) and were significantly superior to FSE-RT-T2WI (P < 0.001). Both LD and LC for DL-RT-T2WI were significantly superior to Arms-RT-T2WI and FSE-RT-T2WI in two readers (P < 0.001). DC for DL-RT-T2WI scored best, significantly superior to Arms-RT-T2WI (P < 0.010) and FSE-RT-T2WI (P < 0.001).

CONCLUSIONS

The novel ultra-fast DL-RT-T2WI is feasible for liver imaging and lesion characterization and diagnosis, not only offers a significant improvement in acquisition time but also outperforms Arms-RT-T2WI and FSE-RT-T2WI concerning image quality and DC.

Abbreviated magnetic resonance imaging in hepatocellular carcinoma surveillance: A review

Hepatocellular carcinoma (HCC) is one of the most common primary malignancies of the liver and a leading cause for cancer-related deaths worldwide. HCC surveillance aims at early detection. The recommended strategy for screening HCC is biannual ultrasound with or without alpha-fetoprotein. However, this strategy is associated with sub-optimal sensitivity. Abbreviated magnetic resonance imaging (AMRI) is a promising alternative to ultrasound (US) for surveillance of HCC. The data regarding the role of AMRI in HCC screening is evolving. There are different AMRI protocols, each having its merits and disadvantages. In this review, we discuss the need for AMRI, protocols of AMRI and hindrances to widespread adoption of AMRI.

Screening of liver cancer with abbreviated MRI

Current recommendations for the surveillance of HCC are based on the semiannual liver ultrasound (with or without serum alpha-fetoprotein) in patients with cirrhosis and in subgroups with chronic hepatitis B infection. However, the sensitivity of this strategy is suboptimal for the detection of early-stage tumors, especially in obese patients, due to interoperator variability and poor adherence. The detection rate of focal liver lesions is excellent with MRI, making it the best alternative candidate for surveillance. However, performing a full contrast-enhanced MRI is unrealistic because of limited availability and health economics. Abbreviated MRI (AMRI) corresponds to the acquisition of a limited number of sequences with a high detection rate. The theoretical benefits of AMRI are a reduced acquisition time (≤10 min) with improved time-effectiveness and cost-effectiveness compared with conventional MRI, and greater accuracy than ultrasound. Numerous protocols may be performed, including T1-weighted, T2-weighted, and DWI sequences, with or without contrast administration. Although published studies report promising per-patient results, they should be interpreted with caution. Indeed, most studies were simulated, retrospectively reviewing a subset of sequences in relatively small populations who underwent a full MRI. They also included groups that were not representative of screening populations. In addition, most were published by Asian groups, with at-risk populations that were different from Western populations. There are no existing longitudinal studies that directly compare the different AMRI approaches or AMRI to ultrasound. Finally, it is possible that 1 approach will not fit all patients and that strategies should be tailored to the risk of HCC, in particular in relation to the cost and availability of AMRI. Several trials are ongoing to evaluate these questions.

Potential of a Non-Contrast-Enhanced Abbreviated MRI Screening Protocol (NC-AMRI) in High-Risk Patients under Surveillance for HCC

PURPOSE

To evaluate NC-AMRI for the detection of HCC in high-risk patients.

METHODS

Patients who underwent yearly contrast-enhanced MRI (i.e., full MRI protocol) of the liver were included retrospectively. For all patients, the sequences that constitute the NC-AMRI protocol, namely diffusion-weighted imaging (DWI), T2-weighted (T2W) imaging with fat saturation, and T1-weighted (T1W) in-phase and opposed-phase imaging, were extracted, anonymized, and uploaded to a separate research server and reviewed independently by three radiologists with different levels of experience. Reader I and III held a mutual training session. Levels of suspicion of HCC per patient were compared and the sensitivity, specificity, and area under the curve (AUC) using the Mann-Whitney U test were calculated. The reference standard was a final diagnosis based on full liver MRI and clinical follow-up information.

RESULTS

Two-hundred-and-fifteen patients were included, 36 (16.7%) had HCC and 179 (83.3%) did not. The level of agreement between readers was reasonable to good and concordant with the level of expertise and participation in a mutual training session. Receiver operating characteristics (ROC) analysis showed relatively high AUC values (range 0.89-0.94). Double reading showed increased sensitivity of 97.2% and specificity of 87.2% compared with individual results (sensitivity 80.1%-91.7%-97.2%; specificity 91.1%-72.1%-82.1%). Only one HCC (2.8%) was missed by all readers.

CONCLUSION

NC-AMRI presents a good potential surveillance imaging tool for the detection of HCC in high-risk patients. The best results are achieved with two observers after a mutual training session.

Magnetic resonance imaging 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 third in terms of cancer deaths. In clinical practice, magnetic resonance imaging (MRI) 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-fetoprotein, or both, either in surveillance programmes or in clinical settings. According to current guidelines, a single contrast-enhanced imaging study (computed tomography (CT) or MRI) showing typical hallmarks of hepatocellular carcinoma in people with cirrhosis is considered valid to diagnose hepatocellular carcinoma. The detection of hepatocellular carcinoma amenable to surgical resection could improve the prognosis. However, a significant number of hepatocellular carcinomas do not show typical hallmarks on imaging modalities, and hepatocellular carcinoma may, therefore, be 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 MRI may clarify whether the absence of benefit could be related to underdiagnosis. Furthermore, an assessment of the accuracy of MRI 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 MRI for the diagnosis of hepatocellular carcinoma of any size and at any stage in adults with chronic liver disease. Secondary: to assess the diagnostic accuracy of MRI for the diagnosis of resectable hepatocellular carcinoma in adults with chronic liver disease, and to identify potential sources of heterogeneity in the results.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Hepato-Biliary Group Diagnostic Test of Accuracy Studies Register, the Cochrane Library, MEDLINE, Embase, and three other databases to 9 November 2021. We manually searched articles retrieved, contacted experts, handsearched abstract books from meetings held during the last 10 years, and searched for literature in OpenGrey (9 November 2021). Further information was requested by e-mails, but no additional information was provided. No data was obtained through correspondence with investigators. We applied no language or document-type restrictions.

SELECTION CRITERIA

Studies assessing the diagnostic accuracy of MRI 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 we 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 34 studies, with 4841 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, we judged 15% (5/34) of studies to be at low concern and 85% (29/34) of studies to be at high concern mostly owing to characteristics of the participants, most of whom were on waiting lists for orthotopic liver transplantation, and due to pathology of the explanted liver being the only reference standard. MRI for hepatocellular carcinoma of any size and stage: sensitivity 84.4% (95% CI 80.1% to 87.9%) and specificity 93.8% (95% CI 90.1% to 96.1%) (34 studies, 4841 participants; low-certainty evidence). MRI for resectable hepatocellular carcinoma: sensitivity 84.3% (95% CI 77.6% to 89.3%) and specificity 92.9% (95% CI 88.3% to 95.9%) (16 studies, 2150 participants; low-certainty evidence). 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

We found that using MRI as a second-line imaging modality to diagnose hepatocellular carcinoma of any size and stage, 16% of people with hepatocellular carcinoma would be missed, and 6% of people without hepatocellular carcinoma would be unnecessarily treated. For resectable hepatocellular carcinoma, we found that 16% of people with resectable hepatocellular carcinoma would improperly not be resected, while 7% 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.

Inter-reader agreement of abbreviated magnetic resonance imaging for hepatocellular carcinoma detection: a systematic review and meta-analysis

PURPOSE

To determine the inter-reader agreement of abbreviated magnetic resonance imaging (AMRI) for the detection of hepatocellular carcinoma (HCC) and explore the causes of heterogeneity between the reported results.

METHODS

Original studies reporting the inter-reader agreement of AMRI for detecting HCC were identified in MEDLINE, EMBASE, and Cochrane databases. The pooled kappa coefficient (κ) was calculated using the DerSimonian-Laird random-effects model. Subgroup analyses were performed according to the AMRI protocol (non-contrast [NC]-AMRI, dynamic contrast-enhanced [DCE]-AMRI, and hepatobiliary phase [HBP]-AMRI). Meta-regression analyses were performed to further explore study heterogeneity.

RESULTS

In the eight included studies (1182 patients), the overall pooled κ was 0.76 (95% confidence interval [CI], 0.70-0.82; I² = 74.4%). The κ of NC-AMRI, DCE-AMRI, and HBP-AMRI were 0.72 (95% CI, 0.62-0.82), 0.80 (95% CI, 0.78-0.82), and 0.98 (95% CI, 0.95-1.00), respectively. In the NC-AMRI, the pooled κ of NC-AMRI using only diffusion-weighted imaging (DWI) was 0.64, which was lower than the values using two or more imaging sequences (κ = 0.74-0.77). In subgroup analysis, no study heterogeneity was noted in studies using DCE-AMRI (I² = 0%), whereas high heterogeneity was noted with NC-AMRI (I² = 80.5%). Especially, NC-AMRI including more than two imaging sequences showed high residual heterogeneity (I² = 87.6%). Meta-regression analysis found that difference in reader experience was significantly associated with study heterogeneity (p = .02).

CONCLUSION

AMRI for detecting HCC showed substantial inter-reader agreement across all examined protocols. NC-AMRI, notably NC-AMRI using only DWI, had relatively low inter-reader agreement. Therefore, DCE-AMRI or HBP-AMRI may be more reliable than NC-AMRI using only DWI.

Noncontrast MRI for Hepatocellular Carcinoma Detection: A Systematic Review and Meta-analysis - A Potential Surveillance Tool?

BACKGROUND AND AIMS

This meta-analysis investigates the diagnostic performance of non-contrast magnetic resonance imaging (MRI) for the detection of hepatocellular carcinoma (HCC).

METHODS

A systematic review was performed to May 2020 for studies which examined the diagnostic performance of non-contrast MRI (multi-sequence or diffusion-weighted imaging (DWI)- alone) for HCC detection in high risk patients. The primary outcome was accuracy for the detection of HCC. Random effects models were used to pool outcomes for sensitivity, specificity, positive likelihood ratio (LR) and negative LR. Subgroup analyses for cirrhosis and size of the lesion were performed.

RESULTS

Twenty-two studies were included involving 1685 patients for per-patient analysis and 2128 lesions for per-lesion analysis. Multi-sequence non-contrast MRI (NC-MRI) using T2+DWI±T1 sequences had a pooled per-patient sensitivity of 86.8% (95%CI:83.9-89.4%), specificity of 90.3% (95%CI:87.3-92.7%), and negative LR of 0.17 (95%CI:0.14-0.20). DWI-only MRI (DW-MRI) had a pooled sensitivity of 79.2% (95%CI:71.8-85.4%), specificity of 96.5% (95%CI:94.3-98.1%) and negative LR of 0.24 (95%CI:1.62-0.34). In patients with cirrhosis, NC-MRI had a pooled per-patient sensitivity of 87.3% (95%CI:82.7-91.0%) and specificity of 81.6% (95%CI:75.3-86.8%), whilst DWI-MRI had a pooled sensitivity of 71.4% (95%CI:60.5-80.8%) and specificity of 97.1% (95%CI:91.9-99.4%). For lesions <2 cm, the pooled per-lesion sensitivity was 77.1% (95%CI:73.8-80.2%). For lesions >2 cm, pooled per-lesion sensitivity was 88.5% (95%CI:85.0-91.5%).

CONCLUSION

Non-contrast MRI has a moderate negative LR and high specificity with acceptable sensitivity for the detection of HCC, even in patients with cirrhosis and with lesions <2 cm. Prospective trials to validate if non-contrast MRI can be used for HCC surveillance is warranted.

Imaging Diagnosis of HCC: Future directions with special emphasis on hepatobiliary MRI and contrast-enhanced ultrasound

Hepatocellular carcinoma (HCC) is a unique cancer entity that can be noninvasively diagnosed using imaging modalities without pathologic confirmation. In 2018, several major guidelines for HCC were updated to include hepatobiliary contrast agent magnetic resonance imaging (HBA-MRI) and contrast-enhanced ultrasound (CEUS) as major imaging modalities for HCC diagnosis. HBA-MRI enables the achievement of high sensitivity in HCC detection using the hepatobiliary phase (HBP). CEUS is another imaging modality with real-time imaging capability, and it is reported to be useful as a second-line modality to increase sensitivity without losing specificity for HCC diagnosis. However, until now, there is an unsolved discrepancy among guidelines on whether to accept “HBP hypointensity” as a definite diagnostic criterion for HCC or include CEUS in the diagnostic algorithm for HCC diagnosis. Furthermore, there is variability in terminology and inconsistencies in the definition of imaging findings among guidelines; therefore, there is an unmet need for the development of a standardized lexicon. In this article, we review the performance and limitations of HBA-MRI and CEUS after guideline updates in 2018 and briefly introduce some future aspects of imaging-based HCC diagnosis.

Abbreviated MRI for hepatocellular carcinoma screening: A systematic review and meta-analysis

BACKGROUND & AIMS

Biannual ultrasound has poor sensitivity for hepatocellular carcinoma (HCC) screening. MRI is accurate for the detection of HCC, but a complete MRI is not feasible as a screening tool. Abbreviated MRI (AMRI) is an acceptable alternative. The diagnostic performance of different AMRI protocols is not known. We performed a systematic review to determine the diagnostic accuracy of AMRI for HCC screening.

METHODS

We searched the MEDLINE and EMBASE databases for studies reporting the diagnostic accuracy of AMRI for HCC screening. The pooled sensitivity and specificity of different AMRI protocols were calculated based on a random intercept logistic regression model. The diagnostic performance of AMRI was compared with ultrasound. Study quality was assessed using the QUADAS-2 tool.

RESULTS

Of the 11,327 studies screened by titles, 15 studies (3 prospective and 12 retrospective: 2,807 patients, 917 with HCC) were included in the final analysis. The pooled per-patient sensitivity and specificity were 86% (95% CI 84-88%, I² 0%) and 94% (95% CI 91-96%, I² 83%), respectively. Pooled per-lesion sensitivity was 77% (95% CI 74-81%, I² 8%). There was no influence of study type, screening setting, reference standard, and presence and etiology of cirrhosis on the performance of AMRI. The sensitivity of AMRI for detection of HCC <2 cm was lower than that for HCC ≥2 cm (69% vs. 86%). The sensitivity and specificity of non-contrast AMRI were comparable to contrast-enhanced AMRI (86% and 94% vs. 87% and 94%, respectively). The diagnostic performance of different non-contrast AMRI and contrast-enhanced AMRI protocols was comparable. The sensitivity of ultrasound was lower than AMRI (53% vs. 82%).

CONCLUSIONS

AMRI has high sensitivity and specificity for HCC screening. Different AMRI protocols have comparable diagnostic performance.

LAY SUMMARY

Abbreviated MRI (AMRI) has been suggested as an alternative to ultrasound and complete MRI for hepatocellular carcinoma (HCC) screening. Our study results showed that AMRI has a high per-patient and per-lesion sensitivity for HCC. Although the sensitivity of AMRI for detection of HCC <2 cm is considerably lower than for HCC ≥2 cm, it is substantially higher than ultrasound, making it a potential alternative for HCC screening in high-risk populations.

United adversarial learning for liver tumor segmentation and detection of multi-modality non-contrast MRI

Simultaneous segmentation and detection of liver tumors (hemangioma and hepatocellular carcinoma (HCC)) by using multi-modality non-contrast magnetic resonance imaging (NCMRI) are crucial for the clinical diagnosis. However, it is still a challenging task due to: (1) the HCC information on NCMRI is insufficient makes extraction of liver tumors feature difficult; (2) diverse imaging characteristics in multi-modality NCMRI causes feature fusion and selection difficult; (3) no specific information between hemangioma and HCC on NCMRI cause liver tumors detection difficult. In this study, we propose a united adversarial learning framework (UAL) for simultaneous liver tumors segmentation and detection using multi-modality NCMRI. The UAL first utilizes a multi-view aware encoder to extract multi-modality NCMRI information for liver tumor segmentation and detection. In this encoder, a novel edge dissimilarity feature pyramid module is designed to facilitate the complementary multi-modality feature extraction. Secondly, the newly designed fusion and selection channel is used to fuse the multi-modality feature and make the decision of the feature selection. Then, the proposed mechanism of coordinate sharing with padding integrates the multi-task of segmentation and detection so that it enables multi-task to perform united adversarial learning in one discriminator. Lastly, an innovative multi-phase radiomics guided discriminator exploits the clear and specific tumor information to improve the multi-task performance via the adversarial learning strategy. The UAL is validated in corresponding multi-modality NCMRI (i.e. T1FS pre-contrast MRI, T2FS MRI, and DWI) and three phases contrast-enhanced MRI of 255 clinical subjects. The experiments show that UAL gains high performance with the dice similarity coefficient of 83.63%, the pixel accuracy of 97.75%, the intersection-over-union of 81.30%, the sensitivity of 92.13%, the specificity of 93.75%, and the detection accuracy of 92.94%, which demonstrate that UAL has great potential in the clinical diagnosis of liver tumors.

Meta-Analysis of the Accuracy of Abbreviated Magnetic Resonance Imaging for Hepatocellular Carcinoma Surveillance: Non-Contrast versus Hepatobiliary Phase-Abbreviated Magnetic Resonance Imaging

Simple Summary

Ultrasonography is recommended as a standard surveillance modality, but the performance of surveillance ultrasound for detecting early-stage hepatocellular carcinoma (HCC) is limited. Motivated to provide a more sensitive method, abbreviated magnetic resonance imaging (AMRI) protocols have been introduced for HCC surveillance. We aimed to systematically determine the diagnostic performance of surveillance AMRI for detecting HCC. This meta-analysis of 10 studies comprising 1547 patients found that the pooled sensitivity and specificity of surveillance AMRI for detecting HCC were 86% and 96%, respectively. Hepatobiliary phase contrast-enhanced AMRI showed significantly higher sensitivities for detecting HCC than non-contrast AMRI (87% vs. 82%), but significantly lower specificities (93% vs. 98%). Therefore, surveillance AMRI had overall good diagnostic performance for detecting HCC and might be clinically useful for HCC surveillance. In addition, AMRI protocol should be selected with consideration of the advantages and disadvantages of each protocol.

Abstract

We aimed to determine the performance of surveillance abbreviated magnetic resonance imaging (AMRI) for detecting hepatocellular carcinoma (HCC), and to compare the performance of surveillance AMRI according to different protocols. Original research studies reporting the performance of surveillance AMRI for the detection of HCC were identified in MEDLINE, EMBASE, and Cochrane databases. The pooled sensitivity and specificity of surveillance AMRI were calculated using a hierarchical model. The pooled sensitivity and specificity of contrast-enhanced hepatobiliary phase (HBP)-AMRI and non-contrast (NC)-AMRI were calculated and compared using bivariate meta-regression. Ten studies, including 1547 patients, reported the accuracy of surveillance AMRI. The pooled sensitivity and specificity of surveillance AMRI for detecting any-stage HCC were 86% (95% confidence interval (CI), 80–90%; I² = 0%) and 96% (95% CI, 93–98%; I² = 80.5%), respectively. HBP-AMRI showed a significantly higher sensitivity for detecting HCC than NC-AMRI (87% vs. 82%), but significantly lower specificity (93% vs. 98%) (p = 0.03). Study quality and MRI magnet field strength were factors significantly associated with study heterogeneity (p ≤ 0.01). In conclusion, surveillance AMRI showed good overall diagnostic performance for detecting HCC. HBP-AMRI had significantly higher sensitivity for detecting HCC than NC-AMRI, but lower specificity.