Pitfalls in the imaging diagnosis of hepatocellular nodules in the cirrhotic and noncirrhotic liver

Gallbladder fossa nodularity in the liver as observed in alcoholic liver disease patients: Analysis based on hepatobiliary phase signal intensity on gadoxetate-enhanced MRI and extracellular volume fraction calculated from routine CT data

The purpose of this study is to further verify the concept utilizing signal intensity on hepatobiliary phase (HBP) of gadoxetate-enhanced MRI and extracellular volume fraction (ECV) calculated from CT data. Between Jan 2013 and September 2018, consecutive ALD patients who had both quadruple phase CT and gadoxetate-enhanced MRI within six months were retrospectively recruited. Those who had any intervention or disease involvement around gallbladder fossa were excluded. All images were reviewed and ECV was measured by two experienced radiologists. GBFN grades, and their HBP signal intensity or ECV relative to the surrounding background liver (BGL) were analyzed. There were 48 patients who met the inclusion criteria. There were GBFN grade 0/1/2/3 in 11/15/18/4 patients, respectively. The signal intensity on HBP relative to BGL were iso/slightly high/high in 30/15/3 patients, respectively, and ECV ratio (ECV of GBFN divided by that of BGL) was 0.88 ± 0.18, indicating there are more functioning hepatocytes and less fibrosis in GBFN than in BGL. The GBFN grades were significantly correlated to relative signal intensity at HBP (Spearman's rank correlation, p < 0.01, rho value 0.53), and ECV ratio (p < 0.01, rho value -0.45). Our results suggest GBFN in ALD would represent liver tissues with preserved liver function with less fibrosis, as compared to BGL, which are considered to support our hypothesis as shown above.

Gallbladder fossa nodularity in the liver typically observed in patients with alcoholic liver disease; comparison with chronic hepatitis C patients

BACKGROUND AND PURPOSE

Gallbladder fossa nodularity (GBFN) is often observed in patients with alcoholic liver disease (ALD), and we hypothesized this may be due to the cholecystic venous drainage (CVD), sparing this area from portal perfusion containing alcohol absorbed in the alimentary tract, and also escaping from alcohol-induced fibrotic and atrophic change of the liver parenchyma. The purpose of this study is to verify our hypothesis, using chronic hepatitis C (CHC) patients as a control.

MATERIALS AND METHODS

Between 2013 and 2017, consecutive 45 ALD and 46 CHC patients who had contrast-enhanced CT were retrospectively recruited. Those who had interventions or disease involvement around gallbladder fossa were excluded. All CT images, and angiography-assisted CT(ang-CT) images , when available, were reviewed. GBFN was subjectively classified into grades 0-3, depending upon the conspicuity of nodularity, which was compared between the groups, and was also correlated to various clinicoradiological factors, including the alcohol consumption grades (ACG).

RESULTS

GBFN was more frequently observed in ALD than in CHC patients, and higher grade GBFN was associated with ALD rather than CHC (all p < 0.05). Multivariable analysis revealed independently significant factors related to GBFN grades were ACG and albumin-bilirubin grades. Ang-CT images were available in 11 patients, all of whom exhibited portal perfusion diminishment and faint arterial enhancement, suggesting CVD, at the region of GBFN. When GBFN grade 3 was considered to discriminate ALD from CHC, the value of sensitivity/specificity/accuracy is 9%/100%/55%.

CONCLUSION

GBFN may represent spared liver tissue from alcohol-containing portal venous perfusion due to CVD, which may serve as an adjunctive sign of ALD or alcohol overconsumption with high specificity, but low sensitivity.

Dynamic changes in ultrasound characteristics of nodules in cirrhotic liver and their implications in surveillance for malignancy

OBJECTIVE

To investigate whether there are ultrasound characteristics that can suggest HCC in ultrasound surveillance of nodules in cirrhotic liver.

METHODS

Data from 277 patients with hepatitis B virus-related nodules in cirrhotic liver undergoing ultrasound surveillance of the nodules for malignancy were reviewed. Size of the nodules ranged 6-23 mm. The nodules were followed by color Doppler ultrasound at 3- to 6-month intervals, with focus on size, shape, echogenicity, margin, halo sign, and vasculature. Suspicious malignant nodules underwent contrast-enhanced CT/MRI, and some indeterminate nodules underwent biopsy.

RESULTS

Nodules in 189 patients were hypo/isoechoic/faint high echoic, 23 were hyperechoic, and 65 were both hypo/isoechoic/faint high echoic and hyperechoic. Forty-two patients developed hepatocellular carcinoma: 35 from nodules and 7 from background parenchyma. Fourteen nodules recessed (size >10 mm), 11 new nodules emerged (size >10 mm), and the total number of nodules increased over 5 years. All hepatocellular carcinomas developed from hypo/isoechoic/faint high echoic nodules, and no typical hyperechoic nodules developed into hepatocellular carcinomas. The size increased significantly when the nodules developed into hepatocellular carcinomas. No nodule presented an overt halo, seven hepatocellular carcinomas developed from nodules with a halo, and ill-defined margins of 16 nodules became well defined when they developed into hepatocellular carcinomas. No vasculature was detectable in the nodules, while it was detectable in eight hepatocellular carcinomas. No significant change occurred in nodules without malignancy.

CONCLUSION

The characteristics for dynamic surveillance of nodules in cirrhotic liver for malignancy should include nodule growth, margin, halo, and vasculature. Apart from evident growth, an ill-defined margin becoming a well-defined margin, a newly emerged halo, and newly detectable vasculature are strongly suggestive of nodule malignancy.

Predictors of microscopic portal vein invasion by hepatocellular carcinoma: measurement of portal perfusion defect area ratio

OBJECTIVE

Microscopic portal vein invasion (PVI) by cancer cells is a poor prognostic factor after hepatic resection for hepatocellular carcinoma (HCC). The aim of this study is to predict PVI preoperatively in patients with HCC.

METHODS

We studied 46 hepatectomized patients who had HCC without any portal venous invasion detected during preoperative radiographic evaluation. We defined the portal perfusion defect area ratio (PPDAR) as the following: the quotient of the maximal portal perfusion defect area, on computed tomography during arterio-portography (CTAP) is divided by the maximal tumor area on magnetic resonance imaging (MRI) or CT.

RESULTS

The median PPDAR was 1.3 (mean 1.4 +/- 1.1; ranged from 0.7 to 5.8). The incidence of PVI was 4.5% in patients with a PPDAR <1.3, 35.7% in those with a PPDAR of 1.3-1.6, 70% in those with a PPDAR > or = 1.6 (P = 0.0005). When analyzing the preoperative value of different cut-off points for the PPDAR, the lowest P-value by Fisher's exact test was achieved when the PPDAR threshold was 1.6 (P = 0.0012). The sensitivity was 58%, and specificity was 91% with this cut-off value. On univariate analyses, factors that significantly correlated with PVI were PPDAR (P = 0.0012), serum levels of des-gamma-carboxy prothrombin (P = 0.033), and tumor size (P = 0.0126). On multivariate analysis, PPDAR was the only significant independent predictor of PVI.

CONCLUSION

Our study shows that PPDAR is a new concept, which is useful in predicting PVI and that a value > or = 1.6 is predictive of PVI.

Multistep human hepatocarcinogenesis: correlation of imaging with pathology

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. The majority of HCCs develop in cirrhotic livers, and the early detection and characterization of this entity is very important. Pathologically, human HCC develops in a multistep fashion in the following sequence: from low-grade dysplastic nodule (LGDN), to high-grade dysplastic nodule (HGDN), early HCC, well-differentiated HCC, nodule-in-nodule HCC, and, finally, to moderately differentiated HCC. Differentiation between early HCC and DN is the most important issue in the clinical setting. CT during hepatic angiography (CTHA) and CT during arterial portography (CTAP) are the most sensitive tools in the differentiation of premalignant/borderline lesions (LGDN and HGDN) and early HCC. Recent progress in imaging modality, especially Sonazoidenhanced US and Gd-EOB-DTPA MRI, is starting to play a very important role in the imaging of multistep hepatocarcinogenesis, resulting in changing the therapeutic strategy of these nodular lesions associated with liver cirrhosis.

Postgastrectomy development or accentuation of focal fatty change in segment IV of the liver: correlation with the presence of aberrant venous branches of the parabiliary venous plexus

BACKGROUND

Focal fatty change in segment IV (S4) of the liver is occasionally a diagnostic dilemma in the postoperative follow-up of gastric cancer patients.

GOAL

To determine whether development of focal fatty change in S4 is related to the presence of aberrant venous branches of the parabiliary venous plexus (PBP).

STUDY

Two hundred seventy-six patients with gastrectomy who had been imaged by thin-slice preoperative computed tomography (CT) and at least one postoperative CT, and had no apparent liver masses were retrospectively analyzed. Preoperative CT were evaluated for the presence of aberrant venous branches of PBP entering S4. Serial postoperative CTs were evaluated for any interval change in the appearance of S4 of the liver.

RESULTS

There were 6 patients out of 276 (2%) in whom focal fatty liver developed or accentuated after the surgery. In 5 out of the 6, preoperative CT demonstrated aberrant branches of PBP; 3 of these were suggested to be aberrant right gastric veins, and the etiologies were not determined in 2. In 1 case, no definite aberrant vessel was seen. Aberrant vessels were found in none of the remaining 270 patients. The incidence of aberrant vessels was significantly higher in patients who developed postoperative radiologic change in S4 than in those who did not (P<0.0001).

CONCLUSIONS

Development or accentuation of focal fatty liver in S4 of the liver was observed in 2% of postgastrectomy patients and was closely related to the presence of aberrant venous branches of PBP.

Early Detection and Characterization of Hepatocellular Carcinoma: Value of Imaging Multistep Human Hepatocarcinogenesis

The method for early detection of hepatocellular carcinoma (HCC) has been well established in Japan, by means of regularly screening patients at risk for developing HCC by imaging and serological markers of tumor. The principal screening protocol includes performing ultrasonography (US) every 3 months and testing for tumor markers every month in patients at high risk for HCC. There has been another important issue of accurate characterization of nodular lesions found in cirrhotic liver. This problem has been solved by the development of imaging modalities such as US angiography with intra-arterial injection of CO(2), computed tomography during hepatic arteriography and computed tomography during arterial portography. It is most important to differentiate the typical hemodynamic patterns of a low-grade dysplastic nodule having arterial hypovascularity with portal perfusion preserved from those of HCC characterized by arterial hypervascularity with decreased portal perfusion. At present, these findings are easily obtained by contrast-enhanced phase invasion harmonic imaging, which is a noninvasive US technology.