The clinical outcome of small (<20 mm) arterially enhancing nodules on MRI in the cirrhotic liver

Diagnosis of Sarcopenia Using the L3 Skeletal Muscle Index Estimated From the L1 Skeletal Muscle Index on MR Images in Patients With Cirrhosis

BACKGROUND

Cirrhotic patients with sarcopenia have poor prognoses and higher mortality. The third lumbar vertebra (L3) skeletal muscle index (SMI) is widely used to assess sarcopenia. However, L3 is generally outside the scanning volume on standard liver MRI.

PURPOSE

To investigate SMIs change between slices in cirrhotic patients and the relationships between SMI at the 12th thoracic vertebra (T12), the first lumbar vertebra (L1) and the second lumbar vertebra (L2) levels and L3-SMI and assess the accuracy of the estimated L3-SMIs in diagnosing sarcopenia.

STUDY TYPE

Prospective.

SUBJECTS

A total of 155 cirrhotic patients (109 with sarcopenia, 67 male; 46 without sarcopenia, 18 male).

FIELD STRENGTH/SEQUENCE

A 3.0 T, 3D dual-echo T1-weighted gradient echo sequence (T1WI).

ASSESSMENT

Two observers analyzed T12 to L3 skeletal muscle area (SMA) in each patient based on T1W water images and calculated the SMI (SMA/height2 ). Reference standard was L3-SMI.

STATISTICAL TESTS

Intraclass correlation coefficient (ICC), Pearson correlation coefficients (r), and Bland-Altman plots. Models relating L3-SMI to the SMI at T12, L1, and L2 levels were constructed using 10-fold cross-validation. Accuracy, sensitivity, and specificity were calculated for the estimated L3-SMIs for diagnosing sarcopenia. P < 0.05 was considered statistically significant.

RESULTS

Intraobserver and interobserver ICCs were 0.998-0.999. The L3-SMA/L3-SMI were correlated with the T12 to L2 SMA/SMI (r = 0.852-0.977). T12-L2 models had mean-adjusted R2 values of 0.75-0.95. The estimated L3-SMI from T12 to L2 levels to diagnose sarcopenia had good accuracy (81.4%-95.3%), sensitivity (88.1%-97.0%), and specificity (71.4%-92.9%). The recommended L1-SMI threshold of 43.24 cm2 /m2 in males and 33.73 cm2 /m2 in females.

DATA CONCLUSION

The estimated L3-SMI from T12, L1 and L2 levels had good diagnostic accuracy in assessing sarcopenia in cirrhotic patients. Although L2 was best associated with L3-SMI, L2 is generally not included in standard liver MRI. L3-SMI estimate from L1 may therefore be most clinically applicable.

EVIDENCE LEVEL

1.

TECHNICAL EFFICACY

Stage 2.

Agreement and correlation of abdominal skeletal muscle area measured by CT and MR imaging in cirrhotic patients

Background

CT-based abdominal skeletal muscle area (SMA) serves as a standard for assessing muscle mass in patients with cirrhosis. Few studies have used MR imaging to measure SMA in cirrhotic patients. The purpose of this study was to investigate the agreement and correlation of the SMA measured by MRI and CT in cirrhotic patients.

Methods

CT and MR images from 38 cirrhotic patients were analyzed using the Slice-O-Matic V5.0 software. One observer independently measured SMA at the mid-third lumbar vertebral (L3) level on CT and MR images. The intraclass correlation coefficient (ICC), Pearson correlation coefficient, and Bland–Altman plot were used to evaluate the agreement and correlation between CT and MRI SMA and their relationship with the sarcopenia severity and Child–Pugh grades.

Results

CT and MRI had a high intraobserver agreement, with ICCs ranging from 0.991 to 0.996. CT and MRI measurements were closely correlated (r = 0.991–0.998, all for P < 0.01), and the bias of the measurements was 0.68–3.02%. Among all MR images, T1w water images had the strongest correlation (r = 0.998, P < 0.01) and the minimum bias of 0.68%. The measurements of mid-L3 SMA on CT and T1w water images remained highly consistent in cirrhotic patients with different severities of sarcopenia and Child–Pugh grades.

Conclusions

MRI and CT showed high agreement and correlation for measuring mid-L3 SMA in cirrhotic patients. In addition to CT, MR images can also be used to assess muscle mass in cirrhotic patients, regardless of the severity of sarcopenia and Child–Pugh grades.

Atypical Manifestation of Primary Hepatocellular Carcinoma and Hepatic Malignancy Mimicking Lesions

Hepatocellular carcinoma (HCC) can be diagnosed noninvasively on multiphasic CT and MRI based on its distinctive imaging findings. These features include arterial phase hyperenhancement and washout on portal or delayed phase images. However, radiologists face significant diagnostic challenges because some HCCs exhibit atypical imaging characteristics. In addition to many HCC-mimicking lesions, such as arterioportal shunts, combined HCC-cholangiocarcinoma, intrahepatic cholangiocarcinoma, and hemangioma present a challenge for radiologists in actual clinical practice. The ability to distinguish HCCs from mimickers on initial imaging examinations is crucial for appropriate management and treatment decisions. Therefore, this pictorial review presents the imaging findings of atypical HCCs and HCCs mimicking malignant and benign lesions and discusses important clues that may help narrow down the differential diagnosis.

Surgically Diagnosed Primary Hepatic Angiosarcoma

Primary hepatic angiosarcoma is a rare tumor originating from endothelial cells in the liver and accounts for approximately 1% of all hepatic malignant tumors. It is difficult to diagnose due to the lack of specific symptoms or tumor markers. No effective treatment exists, but complete surgical resection may achieve a good outcome. Since most primary hepatic angiosarcomas are already at an advanced stage at diagnosis, few reports describe tumors smaller than 2 cm. We report a case of surgery for a 1.7-cm sized primary hepatic angiosarcoma. Further studies are required to improve the preoperative diagnosis of primary hepatic angiosarcoma.

Diagnosis of Hepatocellular Carcinoma with Gadoxetic Acid-Enhanced MRI: 2016 Consensus Recommendations of the Korean Society of Abdominal Radiology

Diagnosis of hepatocellular carcinoma (HCC) with gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) poses certain unique challenges beyond the scope of current guidelines. The regional heterogeneity of HCC in demographic characteristics, prevalence, surveillance, and socioeconomic status necessitates different treatment approaches, leading to variations in survival outcomes. Considering the medical practices in Korea, the Korean Society of Abdominal Radiology (KSAR) study group for liver diseases has developed expert consensus recommendations for diagnosis of HCC by gadoxetic acid-enhanced MRI with updated perspectives, using a modified Delphi method. During the 39th Scientific Assembly and Annual Meeting of KSAR (2016), consensus was reached on 12 of 16 statements. These recommendations might serve to ensure a more standardized diagnosis of HCC by gadoxetic acid-enhanced MRI.

Subcentimeter hypervascular nodule with typical imaging findings of hepatocellular carcinoma in patients with history of hepatocellular carcinoma: natural course on serial gadoxetic acid-enhanced MRI and diffusion-weighted imaging

OBJECTIVES

To evaluate the natural course of subcentimeter hypervascular nodules at high risk for developing into hepatocellular carcinomas (SHNHR) using serial magnetic resonance imaging (MRI) in patients with a history of hepatocellular carcinoma (HCC).

METHODS

An SHNHR was defined as a subcentimeter hypervascular nodule having typical imaging findings of HCC on gadoxetic acid-enhanced MRI and diffusion-weighted imaging. We included 39 patients with 46 SHNHRs (mean size ± standard deviation, 6.1 ± 1.6 mm; range, 3.2 - 9.0 mm). Overt HCC was defined as pathology proven HCC or a nodule larger than 1 cm with typical imaging findings of HCC. The cumulative rate and the independent predictive factors for progression to overt HCC were evaluated.

RESULTS

The median follow-up period was 139 days (range, 64 - 392 days). The cumulative progression rate to overt HCC at 3, 6, 9, and 12 months was 13.9%, 61.7%, 83.2%, and 89.9%. The initial size of SHNHR was a significant predictor of progression to overt HCC, with an optimal cut-off value of 5.5 mm.

CONCLUSION

The progression rate of SHNHR to overt HCC within 12 months was high (89.9%) in patients with history of HCC. The initial size of SHNHR was an important predictor for progression to overt HCC.

KEY POINTS

• Most SHNHRs (89.9%) progressed to overt HCCs within 12 months. • Initial size was an important predictor for progression to overt HCCs. • The optimal cut-off value for initial nodule size was 5.5 mm.

Magnetic resonance imaging in cirrhosis: what's new?

Cirrhosis is the main risk factor for the development of hepatocellular carcinoma (HCC). The major causative factors of cirrhosis in the United States and Europe are chronic hepatitis C infection and excessive alcohol consumption with nonalcoholic steatohepatitis emerging as another important risk factor. Magnetic resonance imaging is the most sensitive imaging technique for the diagnosis of HCC, and the sensitivity can be further improved with the use of diffusion-weighted imaging and hepatocyte-specific contrast agents. The combination of arterial phase hyperenhancement, venous or delayed phase hypointensity "washout feature," and capsular enhancement are features highly specific for HCC with reported specificities of 96% and higher. When these features are present in a mass in the cirrhotic liver, confirmatory biopsy to establish the diagnosis of HCC is not necessary. Other tumors, such as cholangiocarcinoma, sometimes occur in the cirrhotic at a much lower rate than HCC and can mimic HCC, as do other benign lesions such as perfusion abnormalities. In this article, we discuss the imaging features of cirrhosis and HCC, the role of magnetic resonance imaging in the diagnosis of HCC and other benign and malignant lesions that occur in the cirrhotic liver, and the issue of nonspecific arterially hyperenhancing nodules often seen in cirrhosis.

Diagnostic accuracy of diffusion-weighted MRI for identifying hepatocellular carcinoma with liver explant correlation

BACKGROUND

The goal of this study was to use liver explant correlation to assess the diagnostic accuracy of diffusion-weighted (DW)-MRI for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Thirty-seven patients were retrospectively identified who had undergone liver transplantation and had preoperative, respiratory-triggered, single-shot echo-planar DW-MRI. Two independent blinded observers evaluated the DW-MRI images for HCC and comparison was made with the explanted specimens.

RESULTS

By pathology, 29 HCCs (mean largest diameter 2.0 cm; range 0.7-4.0 cm) were identified in 20 patients. Sensitivity and specificity for reader 1 were 55 and 92%, and for reader 2 were 45 and 100%. There was 'substantial' inter-observer agreement (kappa = 0.64).

CONCLUSION

DW-MR is not sensitive enough for HCC to be used as a stand-alone sequence, although its high specificity suggests that it is likely valuable as a component of a liver MRI protocol.

Hepatocellular carcinoma lesion characterization: single-institution clinical performance review of multiphase gadolinium-enhanced MR imaging--comparison to prior same-center results after MR systems improvements

PURPOSE

To measure diagnostic performance in the detection of hepatocellular carcinoma (HCC) by using the most recent technology and multiphase gadolinium-enhanced magnetic resonance (MR) imaging and to compare with earlier results at the same institution.

MATERIALS AND METHODS

This retrospective study was institutional review board approved and HIPAA compliant. Informed consent was obtained. Between January 2008 and April 2010, 101 patients underwent liver transplantation and pretransplantation abdominal MR imaging within 90 days. Prospective image interpretations from the clinical record were reviewed for documentation of HCC, including size, number, and location. Liver explant histologic examination provided the reference standard for lesion analysis and was performed in axial gross slices in conjunction with the MR imaging report for direct comparison. Tumors were categorized according to size (≥ 2 cm or <2 cm), and MR imaging detection sensitivity, specificity, predictive values, and accuracy were calculated according to category. The Fisher exact test was used to compare results from this study against prior reported results.

RESULTS

Thirty-five (34.7%) of 101 patients had HCC at explant analysis. Patient-based analysis of all lesions showed a sensitivity and specificity of 97.1% (34 of 35) and 100% (66 of 66), respectively. For lesions 2 cm or larger, MR imaging had a sensitivity and specificity of 100% (23 of 23) and 100% (78 of 78), respectively. For lesions smaller than 2 cm, MR imaging had a sensitivity and specificity of 82.6% (19 of 23) and 100% (78 of 78), respectively. Lesion-based sensitivity for all tumors was 91.4% (53 of 58) in the current study, compared with 77.8% in 2007 (P = .07). For lesions smaller than 2 cm, the sensitivity was 87.5% (28 of 32) in the current study, compared with 55.6% previously (P = .02).

CONCLUSION

MR imaging remains a highly accurate diagnostic method for the preoperative evaluation of HCC, and detection of small (<2 cm) tumors has been significantly improved compared with that of earlier studies.

Imaging of the liver for hepatocellular cancer

BACKGROUND

Imaging of the liver is a key component in the detection, diagnosis, management, and follow-up of patients with hepatocellular carcinoma.

METHODS

The author uses his own experience as well as a review of pertinent literature to describe the capabilities and the limitations of the principal currently available imaging techniques for the liver.

RESULTS

Ultrasound is widely available, but sensitivity and specificity for small nodules are limited. Computed tomography effectively demonstrates extrahepatic lesions and can differentiate between cysts or hemangiomas and hepatocellular carcinomas. Magnetic resonance imaging better characterizes hepatic lesions, but positron emission tomography is of limited value.

CONCLUSIONS

Cross-sectional imaging with ultrasound, CT, or MRI is critical for nodule characterization in the cirrhotic liver, surgical planning of HCC, and treatment response evaluation.

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.

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.

Diagnosis and treatment of hepatocellular carcinoma

The diagnosis and treatment of hepatocellular carcinoma (HCC) have witnessed major changes over the past decade. Until the early 1990s, HCC was a relatively rare malignancy, typically diagnosed at an advanced stage in a symptomatic patient, and there were no known effective palliative or therapeutic options. However, the rising incidence of HCC in several regions around the world coupled with emerging evidence for efficacy of screening in high-risk patients, liver transplantation as a curative option in select patients, ability to make definitive diagnosis using high-resolution imaging of the liver, less dependency on obtaining tissue diagnosis, and proven efficacy of transarterial chemoembolization and sorafenib as palliative therapy have improved the outlook for HCC patients. In this article, we present a summary of the most recent information on screening, diagnosis, staging, and different treatment modalities of HCC, as well as our recommended management approach.