Differentiating hepatocellular carcinoma from dysplastic nodules at gadobenate dimeglumine-enhanced hepatobiliary-phase magnetic resonance imaging

Purpose

We evaluated whether the addition of delayed phase imaging (DPI) gadobenate dimeglumine-enhanced MRI to dynamic postcontrast imaging improves the characterization of small hepatocellular carcinoma (HCC) and the differentiation between HCC, high grade dysplastic nodules (HGDN), and low grade dysplastic nodules (LGDN).

Methods

Twenty-five cirrhotic patients with 30 nodules (16 HCC, 8 HGDNs, and 6 LGDNs; maximum size of 3 cm) were included in this retrospective study. The diagnostic reference standard was histology. All the patients underwent MRI both prior to and following intravenous administration of gadobenate dimeglumine. The lesions were classified as hypointense, isointense, hyperintense on DPI for qualitative assessment. In the quantitative analysis the relative tumor-liver contrast to noise ratio (CNR) of the lesions on DPI was calculated.

Results

All HCCs were hypointense on DPI while only 8 (57.1%) of 14 DNs were hypointense and only 1 of 6 (16.6%) LGDNs was hypointense. There was a statistically significant difference in the hypointensity on DPI between HCCs and DNs (p = 0.003) in the qualitative analysis but not in the CNR values while there was a strong statistically significant difference in the hypointensity on DPI in the qualitative (p = 0.00001) and quantitative analysis (p < 0.05) between LGDNs and the group obtained by unifying HGDNs and HCCs.

Conclusion

DPI is helpful in differentiating HCCs and HGDNs from LGDNs. Demonstration of hypointensity on DPI should raise the suspicion of HGDN or hypovascular HCC in the case of nodules with atypical dynamic pattern.     

Detection of small (≤2 cm) HCC in cirrhotic patients: added value of diffusion MR-imaging

Objectives

To evaluate the usefulness of the diffusion-weighted sequence in the detection of small (≤2 cm) hepatocellular carcinoma (HCC) in patients with cirrhosis.

Methods

Seventy cirrhotic patients with 93 HCCs underwent MR-Imaging at 1.5 T. MR acquisitions comprised unenhanced T1- and T2-weighted images and post-contrast Gd-BOPTA-enhanced T1W GRE-3D images acquired after approximately 25, 60, 180 s (dynamic phases) and 90 min (hepatobiliary phase). DWI was performed by a SSEPI sequence (b values 0, 50, 400, 800 s/mm²). Quantitative analysis was performed to establish significant difference of ADC values of benign lesions compared with that of HCC. Sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of two different protocols with and without diffusion MRI sequence were also calculated and compared each other.

Results

A good inverse correlation was found between reference standard and ADC values (ρ = ?0.688). The mean ADC value of HCC was significantly lower than the mean value of benign focal liver lesions (p < 0.0001). No significant difference was reported in term of sensitivity, specificity, PPV, NPV and diagnostic accuracy between the two datasets. A trend to a better sensitivity was found when DWI images were considered.

Conclusions

The adjunction of DWI does not significantly improve the diagnostic accuracy in the detection of small HCC.     

Primary hepatic neuroendocrine carcinoma: MR imaging findings including preliminary observation on diffusion-weighted imaging

Purpose

To investigate MR imaging findings of primary hepatic neuroendocrine carcinoma (PHNEC) including preliminary observations on diffusion-weighted imaging (DWI).

Materials and methods

MR images of eight patients with pathologically confirmed PHNEC were retrospectively analyzed. The morphological characteristics and dynamic enhancement patterns were evaluated.

Results

One case showed a well-defined solitary nodule with homogenous hypointensity on T1-weighted imaging (T1WI) and hyperintensity on T2-weighted imaging (T2WI) and DWI. The remaining seven cases appeared as well-defined dominant masses with multiple satellite nodules. The dominant masses demonstrated heterogeneous hypointensity on T1WI and hyperintensity on T2WI, which all appeared as a marked enhancement at arterial phase and rapid washout at portal venous phase. Six cases demonstrated rim-like enhancement at equilibrium phase. The satellite lesions showed heterogeneous hypointensity on T1WI and marked hyperintensity on T2WI with variable enhancements, such as homogeneous, rim-like enhancement. All the dominant masses and satellite nodules appeared as markedly hyperintensity and reduced apparent coefficient (ADCs) values on DWI. The mean ADC value of the tumors was significantly lower than that of surrounding liver parenchyma (1.02 ± 0.57 vs. 2.24 × 10^?3 mm²/s, p = 0.000).

Conclusion

PHNECs typically appear as a large dominant hypervascular mass accompanied by satellite nodules, with rapid washout and capsular enhancement on dynamic MR imaging and restricted diffusion on DWI.     

Evidence of diagnostic enhancement pattern in hepatocellular carcinoma nodules ≤2 cm according to the AASLD/EASL revised criteria

Purpose

To define the percentage of small (≤2 cm) hepatocellular carcinoma (HCC) nodules showing the diagnostic enhancement pattern at CEUS, computed tomography (CT), and gadobenate dimeglumine (Gd-BOPTA)—enhanced magnetic resonance (MR) imaging.

Methods

42 cirrhotic patients (26 male, 16 female; 67 ± 12 years) with 46 biopsy-proven HCCs ≤2 cm were included. Each HCC was scanned by CEUS, contrast-enhanced CT, and Gd-BOPTA-enhanced MR imaging. Nodule enhancement was evaluated by two readers. Independent analysis was followed by consensual analysis and the proportion of HCCs with the diagnostic enhancement pattern (nodule hyperenhancing on hepatic arterial phase and hypoenhancing on portal venous—late phase) on CEUS, CT, and MR imaging was compared by chi-square test.

Results

Very good inter-reader agreement was observed on hepatic arterial phase and portal venous—late phase: CEUS, k = 0.89 and 0.85; CT, k = 0.91 and 0.88; MR imaging, k = 0.96 and 0.94. CEUS and CT did not differ in the percentage of HCC nodules with a diagnostic enhancement pattern (18/46 and 16/46; P = 0.66), while MR imaging revealed the diagnostic pattern in higher percentage of nodules (29/46; P = 0.012) in comparison to CEUS and CT.

Conclusions

CEUS and contrast-enhanced CT did not differ in the percentage of small HCC nodules with diagnostic enhancement pattern, while Gd-BOPTA-enhanced MR imaging revealed the diagnostic pattern in a higher nodule number in comparison to CEUS and CT.     

Intrahepatic cholangiocarcinoma: relationship between tumor imaging enhancement by measuring attenuation and clinicopathologic characteristics

Purpose

Arterial enhancement of intrahepatic cholangiocarcinoma (ICC) has been noted. To precisely identify the characteristics of tumor enhancement patterns, we examined the relationship between CT attenuation in the tumor and clinicopathological parameters or prognosis.

Methods

Subjects were 42 ICC patients who had undergone hepatectomy. microvessel density (MVD) determined by CD34 staining was compared with imaging. Attenuation was calculated in images from multidetector CT of tumor and non-tumorous regions. Enhancement patterns were divided into two groups: arterial enhancement with higher attenuation (>16 HU; Hyper group, n = 12); and arterial enhancement with lower attenuation (Hypo group, n = 30).

Results

Univariate analysis identified high tumor marker level, increased size, less-differentiation, incomplete resection, increased bleeding, and lower MVD as significantly associated with poor survival (p < 0.05). Increased attenuation throughout the whole ICC correlated significantly with radiological findings and MVD. Concomitant hepatitis, well-differentiation, and smaller tumor were more significantly frequent in the Hyper group than in the Hypo group (p < 0.05). Postoperative early recurrence was significantly less frequent in the Hyper group, and overall survival was significantly better in the Hyper group (p < 0.05).

Conclusions

Increased CT attenuation correlated with ICC tumor vascularity. Increased tumor enhancement in the arterial phase was associated with chronic hepatitis, lower malignancy, and better survival.     

Dynamic enhancing vascular pattern of intrahepatic peripheral cholangiocarcinoma on contrast-enhanced ultrasound: the influence of chronic hepatitis and cirrhosis

Purpose

To analyse the dynamic enhancing features by real-time contrast-enhanced ultrasound (CEUS) of intrahepatic peripheral cholangiocarcinoma (ICC) in patients with chronic hepatitis and cirrhosis.

Materials and methods

CEUS was performed by using contrast pulse sequencing (CPS) imaging with mechanical index of <0.2 after injection of 2.4 mL of contrast agent. CEUS images of histologically confirmed ICC in 54 patents (15 patents with chronic hepatitis B, 16 patents with cirrhosis, and 23 patents with normal underlying liver) were analyzed.

Results

Heterogeneous hyperenhancement was more frequently identified in ICC with chronic hepatitis (9 of 15, 60.0%, p = 0.000) and cirrhosis (8 of 16, 50.0%, p = 0.010) than in patients with normal liver (6 of 23, 26.1%) during arterial phase. The majority of ICC in patients with normal liver displayed peripheral hyperenhancement (13 of 23, 56.5%), than in patients with chronic hepatitis (4 of 15, 26.7%, p = 0.000) and cirrhosis (5 of 16, 31.3%, p = 0.001). Intense contrast uptake during the arterial phase (heterogeneous hyperenhancement or global hyperenhancement) followed by washout in venous phases was more frequently displayed in ICC patients with chronic hepatitis (11 of 15, 73.3%, p = 0.000) and in patients with cirrhosis (11 of 16, 68.8%, p = 0.000) than in ICC patients with normal underlying liver (8 of 23, 34.8%).

Conclusion

The enhancing vascular pattern of ICC on CEUS in patients with chronic hepatitis and cirrhosis is different from that in ICC without underlying liver disease. The enhancing vascular pattern is indistinguishable from HCC on CEUS in most ICC patients with chronic hepatitis or cirrhosis.     

Apparent diffusion coefficient quantification as an early imaging biomarker of response and predictor of survival following yttrium-90 radioembolization for unresectable infiltrative hepatocellular carcinoma with portal vein thrombosis

Purpose

To investigate early diffusion-weighted imaging (DWI) at 30-days post-yttrium-90 (Y-90) radioembolization as a predictor of treatment response and survival in unresectable infiltrative hepatocellular carcinoma (HCC) with portal vein thrombosis (PVT).

Materials and methods

In a prospective study, 18 consecutive patients with unresectable infiltrative HCC and PVT underwent Y-90 therapy. MR imaging was obtained pre Y-90, and at 1 and 3 months post-therapy with DWI fat-suppressed tri-directional diffusion gradient (b = 50, 400, 800 s/mm²). Response was evaluated using target mRECIST and EASL. Relative change in apparent diffusion coefficient (ADC) value of tumors was evaluated. Statistical analysis using receiver operator characteristic curves was performed. Paired t test and Pearson correlation coefficient (r) were used to assess intra- and inter-observer variability. Survival analysis was performed using Kaplan-Meier estimation and log-rank test.

Results

Mean ADC values of all HCC’s at baseline and at 30-days post-Y90 therapy was 0.86 × 10^?3 and 1.17×10^?3 mm²/s, respectively (p < 0.001). Tumors with objective response by mRECIST had significantly increased ADC value when compared to “non-responders” (1.27 vs. 1.05×10^?3 mm²/s, p = 0.002). A >30% increase in ADC value at 30-days was found to be at least 90% sensitive in predicting response at 90 days. A >30% increase in ADC value at 30-days predicted significantly prolonged survival.

Conclusion

A 30% increase in ADC value at 30-days measured post Y90 is a reproducible early imaging response biomarker predicting tumor response and prolonged survival following Y-90 therapy in infiltrative HCC with PVT.     

B-flow imaging of vascular structure for the diagnosis of liver tumor

Purpose

B-flow is a non-Doppler-based technology for visualizing blood flow and has a high spatial resolution. The aim of this study is to evaluate the blood flow information of liver tumors using B-flow in comparison with color Doppler sonography (CDS).

Methods

Seventy-nine patients with 82 hepatic nodules were studied using B-flow and CDS. The study group included 45 HCC nodules, 23 liver metastasis nodules, four intrahepatic cholangiocarcinomas (ICC), and 13 hemangiomas. The visualized vascularity and morphological findings of the hepatic tumor vessel were evaluated.

Results

B-flow showed multiple vessels in 48 nodules (58.5 %) and a single vessel in 13 nodules (15.9 %). CDS showed multiple vessels in 44 nodules (53.7 %) and a single vessel in 23 nodules (28.0 %). Multivariate analysis showed basket pattern was significant for HCC (OR 49.263; p = 0.0002), and penetrating vessel was significant for liver metastasis or ICC (OR 14.545; p < 0.0001).

Conclusion

B-flow detects hepatic tumor blood flow with sensitivity as high as that of CDS. Vascular structure information obtained using B-flow could be potentially used to diagnose liver tumors.     

Contrast-enhanced magnetic resonance imaging of 102 nodules in cirrhosis: correlation with histological findings on explanted livers

Purpose

To analyze Gd-EOB-DTPA-enhanced magnetic resonance (MR) findings of nodules (low-grade dysplastic nodules—LGDNs; high-grade dysplastic nodules—HGDN, and hepatocellular carcinoma—HCC), histologically identified on cirrhotic, explanted livers.

Methods

IRB approval was obtained for this study. Thirty-four patients underwent Gd-EOB-DTPA-enhanced MR examinations (1.5T system), that included 20-min delayed hepatobiliary (HB) phase imaging, before undergoing orthotopic liver transplantation (OLT; mean time MR-OLT: 2.7 months). A total of 102 hepatic nodules were identified and analyzed at histopathological examination, and classified as LGDN, HGDN, and HCC. Two radiologists by consensus performed a quantitative (enhancement ratios, ERs) and a qualitative analyses of signal intensities of identified nodules on vascular dynamic phases (30–35 s after injection–arterial phase; 180–190 s after injection late phase) and on HB phases. Correlation between nodules MR patterns and histological classification was analyzed by means of dedicated statistical software.

Results

No differences were appreciable among ERs of HGDN and HCCs on HB phase (P > 0.001). Lesions’ enhancement on vascular dynamic and on HB phases significantly correlated to histological classification of nodules (P < 0.0001). Nodular hyperintensity on arterial phase and hypointensity on late phase were highly predictive for HCC (PPV 100%), with a moderate sensitivity (72.5%). Nodular hypointensity on HB phase was detected on 39/40 HCCs (sensitivity 97.5%) and in 21/30 HGDNs, whereas no LGDN showed it.

Conclusions

Hyperenhancement on arterial phase and hypointensity on late phase are the most specific clues for the diagnosis of HCC. Hypointensity on HB phase shows a PPV of 100% in suggesting nodular premalignancy/malignancy, independently from nodular dynamic vascular enhancement.     

MR-imaging features of hepatocellular carcinoma capsule appearance in cirrhotic liver: comparison of gadoxetic acid and gadobenate dimeglumine

Purpose

The purpose of the study is to compare the MR-imaging features of hepatocellular carcinoma (HCC) capsule appearance on gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging, using imaging-based presumptive diagnosis of HCC as the reference standard.

Methods

Gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging of 51 patients with 71 HCCs were retrospectively reviewed. Three readers graded in consensus, using a five-point scale, the presence (score 4–5) of capsule appearance on images obtained during T1-weighted GRE portal venous phase (PVP), 3-min phase, and hepatobiliary phase (HBP). The Fisher's exact test and the t student unpaired test were performed.

Results

A hyperintense capsule appearance was present either on PVP or 3-min phase in 11/46 and in 24/25 HCCs imaged with gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging, respectively (24% vs. 96% p < 0.001). A hypointense capsule appearance was present on HBP in 8/46 and 0/22 HCCs evaluated with gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging, respectively (17% vs. 0% p = 0.046). A capsule appearance was detected either on PVP, 3-min phase, or HBP in 17/46 (37%) HCCs after gadoxetic acid injection and in 24/25 (96%) HCCs after gadobenate dimeglumine injection (p < 0.001).

Conclusions

A capsule appearance was more frequently seen on gadobenate dimeglumine-enhanced MR imaging when compared to gadoxetic acid-enhanced MR imaging.

     

Can a b value of 500 be substituted for a b value of 1000 in the characterization of focal liver lesions?

Purpose

Comparison of two different b values in diffusion-weighted magnetic resonance imaging (DWI) for characterization of focal liver lesions.

Methods

A total of 174 focal liver lesions from 100 patients were analyzed using two different b values (500 and 1000 s/mm²). The DWI with b values of 500 s/mm² (DWI500) and 1000 s/mm² (DWI1000) were analyzed using the Mann–Whitney test, kappa statistic, and paired t test with respect to image quality. The statistically significant differences between DWI500 and DWI1000 in the characterization of the lesions with respect to the cutoff ADC values were evaluated via χ ² test.

Results

DWI500 had the highest mean score in the qualitative evaluation of image quality (p < 0.0001) and the highest signal-to-noise ratio (8.7 ± 2.1; p < 0.0001). The sensitivity, specificity, and AUC for discriminating malignant from benign focal lesions on DWI500 and DWI1000 using cutoff ADC values of 1.54 × 10^?3 and 1.38 × 10^?3 s/mm² were 95.8%, 92.3%, 0.98, and 93.8%, 92.3%, 0.97, respectively. There was no statistically significant difference in sensitivity, specificity, and AUC values between DWI500 and DWI1000 with respect to the cutoff ADC values (p > 0.05).

Conclusions

The image quality of DWI500 was better than that of DWI1000, and there was no significant difference between DWI500 and DWI1000 in the characterization of the lesions with respect to the cutoff ADC values. The b value of 500 s/mm² can be substituted for the b value of 1000 s/mm² in the characterization of focal liver lesions.     

Diffusion-weighted MRI in bladder carcinoma: the differentiation between tumor recurrence and benign changes after resection

Purpose

To investigate the efficacy of diffusion-weighted MRI (DWI) in differentiating recurrent tumor from chronic inflammation and fibrosis after cystectomy or transurethral resection of bladder cancer.

Methods

Eleven patients with suspected tumor recurrence underwent pelvic DWI and dynamic contrast-enhanced (DCE) MRI at 3 months to 7 years following bladder cancer resection. The diagnosis was histologically confirmed in all patients by transurethral or cystoscopic resection of 27 lesions within 2 weeks of MR examinations.

Results

The accuracies, sensitivities, specificities, and positive predict values of DWI (92.6%, 100%, 81.8%, and 88.9%) were higher than those of DCE MRI (59.3%, 81.3%, 27.3%, and 54.2%) for detecting recurrent tumors. Using receiver operating characteristic analysis, the accuracy of DWI was significantly higher than that of DCE MRI (P < 0.05). There was no significant difference between DWI diagnosis and histopathology (P > 0.05), whereas the difference between diagnosis of DCE MRI and histopathology was significant (P < 0.05). The normalized apparent diffusion coefficients of recurrent tumors (0.697 ± 0.219) were significantly (P < 0.05) lower than those of postoperative inflammation or fibrosis (1.019 ± 0.143).

Conclusions

DWI is superior to DCE MRI for differentiating recurrent bladder tumors from postoperative inflammation or fibrosis. DWI can be included in the follow-up MRI protocol after bladder cancer surgery.     

Feasibility of blood oxygenation level-dependent MRI at 3T in the characterization of hepatic tumors

Purpose

To determine the feasibility of using blood oxygenation level-dependent (BOLD) MRI in the characterization of hepatic tumors.

Methods

A total of 100 patients with 43 hepatocellular carcinomas (HCCs), 36 metastases, 17 cholangiocarcinomas, and 23 hemangiomas underwent gadoxetic acid-enhanced and BOLD MRI at 3T. BOLD MRI was performed using a multiple fast-field echo sequence (TR/TE, 290/10–28; slice thickness 5 mm) to generate 20 T2*-weighted images. The T2* value of each tumor were calculated. On a color-coded T2* map, tumors were classified into five categories of high signal intensity (strong, moderate, rim, mild) and iso-intensity, which was correlated with the enhancement pattern on dynamic phases by two observers.

Results

The mean T2* value (ms) of hemangiomas (97.3 ± 20.2) was the highest, followed by HCCs (48.4 ± 12.7), metastases (37.1 ± 10.5), and cholangiocarcinomas (36.6 ± 11.1). These values were significantly different (hemangioma vs. others tumors and HCC vs. metastasis or cholangiocarcinoma) (P ≤ 0.001). The agreement between the T2* color map and dynamic images was moderate for all tumors (k = 0.544), good for tumors >2.0 cm (k = 0.666), and fair for tumors ≤2.0 cm (k = 0.334). With the gadoxetic acid-enhanced MRI used as a reference, the sensitivities of BOLD MRI (T2* color map) for displaying hypervascularity of HCC (categories of 1–3) were 81.0 % (n = 34/42) and 78.6 % (n = 33/42) for both observers.

Conclusion

Liver BOLD MRI has a potential to predict the vascular pattern of hepatic tumors.     

Intraductal papillary neoplasm of the bile ducts: description of MRI and added value of diffusion-weighted MRI

Purpose

To evaluate MRI features of intraductal papillary neoplasm of the bile duct (IPNB) and to determine added value of diffusion-weighted MRI (DWI).

Methods

Twenty-three patients with surgically confirmed invasive (n = 12) and non-invasive (n = 11) IPNB, who underwent preoperative liver MRI were included. Two observers performed consensus review of gadoxetic acid-enhanced MRI and combined gadoxetic acid-enhanced MRI including DWI separately, with regard to conspicuity of intraductal tumor using five point scales, extent of tumors, and the presence of invasiveness.

Results

On MRI, there was no significant difference in the conspicuity of intraductal tumors between gadoxetic acid MRI (mean, 4.35) and combined MRI (mean, 4.65) (P = 0.09). However, addition of DWI led seven cases revealed excellent conspicuity as compared with good or moderate conspicuity on gadoxetic acid MRI. With regard to invasiveness, 11 cases (48 %) and 17 (74 %) were correctly diagnosed with gadoxetic acid MRI and combined MRI, respectively (P = 0.06). In invasive tumors, both of the two image sets did not help assess accurate extent of the tumor.

Conclusions

The addition of DWI to gadoxetic acid-enhanced MRI has a potency to improve conspicuity for intraductal tumors of IPNB and is helpful in determining tumor invasiveness, but not tumor extent.     

Preoperative evaluation of myometrial invasion in endometrial carcinoma: diagnostic performance of 3T MRI

Purpose

To evaluate the diagnostic accuracy of 3T MRI in preoperative staging of myometrial invasion.

Methods

Twenty-eight women with histological diagnosis of endometrial carcinoma were included in this prospective study. After T2-W SS-TSE and DWI, dynamic series of T1-W THRIVE images were obtained (0–180 s) followed by a T1-W THRIVE sequence in the late phase (5th min). For detection of deep myometrial infiltration: sensitivity, specificity, PPV, NPV, and accuracy were calculated on T2-W, postcontrast early arterial and late phase T1-W, and DWI. For the quantitative analysis of DWI, ADC values of the tumor were calculated and correlated with histologic grade. For the quantitative evaluation of dynamic series, SI-time curves were obtained and the maximum relative enhancement, wash-in rate, time-to-peak, and wash-out rate of masses and myometrium were compared.

Results

T2-W and early phase contrast-enhanced sequences obtained sensitivity 100 %, specificity 76 %, PPV 58 %, NPV 100 %, and accuracy 82 %; late-phase contrast-enhanced images obtained sensitivity 100 %, specificity 81 %, PPV 64 %, NPV 100 %, and accuracy 86 %; DWI obtained lower accuracy [sensitivity 71 %, specificity 62 %, PPV 38 %, NPV 87 %, and accuary 57 %] than T2-W and postcontrast images. The MRE of carcinomas were significantly lower than those of the myometrium. This analysis showed a significant improvement in tumor versus myometrium contrast during the late phase. On DWI, the mean ADC value of tumor was 1.02 ± 0.48 × 10^?3. There was no statistically significant correlation between tumor grades and ADCs.

Conclusions

As the 3T MRI scanner allows high-resolution images, accurate assessment of myometrial infiltration can be done especially with postcontrast late phase images.     

Multi-modality imaging findings of splenic hamartoma: a report of nine cases and review of the literature

Purpose

To investigate the presentation of splenic hamartomas (SHs) on ultrasonography (US), CT and MRI.

Methods

Nine patients (5 males and 4 females, mean age, 52.8 years) with pathologically proven SHs were included in this study. US, CT and MRI images were analyzed retrospectively, and imaging features were correlated with pathological findings.

Results

SHs appeared solitary lesion (n = 8) and multiple lesions (n = 1) in the present study. (1) In 8 cases of solitary lesion, the lesions appeared as solid nodules or masses with well-defined margins and varying echogenicity (hyperecho = 5, hypoecho = 2, strong echo = 1) on ultrasound. The lesions showed iso-attenuation (n = 3) or slightly hypo-attenuation (n = 4) on unenhanced CT, and calcification were revealed in 3 lesions. MRI showed isointensity (n = 3) or hypointensity (n = 2) on the T1-weighted image, and heterogeneous hypointensity (n = 2), slightly hyperintensity (n = 2) and hyperintensity (n = 1) on the T2-weighted image. The enhanced patterns of SHs showed mild diffuse heterogeneous enhancement (n = 6) and prominent enhancement (n = 1) during arterial phase and above 7 lesions were demonstrated progressive enhancement at delayed phase on enhanced CT. One lesion without any enhancement was revealed in another patient. (2) One case of multiple lesions included 1 cystic lesion with irregular calcification and 7 solid lesions with progressive enhancement on CT images.

Conclusions

Combination of a variety of imaging modalities could more fully reflect the pathological characteristics and contribute to the diagnosis of SH.     

How to not miss alveolar echinococcosis in hepatic lesions suspicious for cholangiocellular carcinoma

Purpose

Hepatic alveolar echinococcosis (AE) resembles intrahepatic cholangiocarcinoma (ICC) on radiological imaging. The purpose of this study was to identify criteria to discriminate AE from ICC with CT and MR Imaging.

Methods

One hundred and sixteen imaging studies of 94 patients (CT n = 65; MRI n = 51) diagnosed with AE (n = 55) or ICC (n = 39) were retrospectively reviewed by two blinded radiologists for lesion features including enhancement pattern and matrix composition. A consensus read was conducted in cases of disagreement. Uni- and multivariate logistic regression with bootstrapping were used for analysis.

Results

Using CT, no or septal enhancement and calcification yielded the highest values of sensitivity/specificity (90.9%/90.6% and 81.8%/96.9%) for AE. Using MRI, no or septal enhancement and cystic components achieved the highest sensitivity/specificity (90.9%/100.0% and 84.8%/66.7%) for AE. Multivariate logistic regression identified the following strong independent predictors for AE: for MRI, no or septal enhancement (odds ratio [OR] 322.4; p < 0.001); for CT, no or septal enhancement and calcification (OR 35.9 and 42.5; p < 0.001 and p < 0.01, respectively). No or septal enhancement and calcification demonstrated the highest interreader agreement (>90%).

Conclusion

Enhancement characteristics and matrix calcifications offer the strongest discriminating potential between AE and ICC with a high sensitivity, specificity, and interreader agreement.

     

Hepatic angiosarcoma: cross-sectional imaging findings in seven patients with emphasis on dynamic contrast-enhanced and diffusion-weighted MRI

Objective

Primary hepatic angiosarcoma is a very rare and aggressive malignancy of vascular origin. We describe cross-sectional imaging findings of this entity with emphasis on dynamic contrast-enhanced (DCE) and diffusion-weighted (DWI) MR imaging.

Methods

Seven cases of pathologically confirmed hepatic angiosarcoma were retrospectively reviewed (CT and MRI examinations were available in seven and six patients, respectively). Two radiologists evaluated lesion growth patterns, attenuation, signal intensity characteristics, contrast enhancement patterns, and apparent diffusion coefficients (ADCs).

Results

Multifocal hepatic disease was present in six patients by means of a mixed pattern of large dominant masses and multiple small nodules; one patient had a solitary large mass. Unenhanced images depicted hemorrhagic areas and a markedly heterogeneous internal architecture within large tumors. Contrast-enhanced early phase images showed variable patterns including patchy peripheral or bizarre shaped intralesional foci of enhancement, peripheral rim enhancement, and small lesions without enhancement. On DCE images, the majority of lesions presented with varying degrees of progressive enhancement. Small nodules frequently displayed homogeneous enhancement on delayed phase images due to complete fill-in. DWI revealed a high interlesional variability of ADC values (range 0.57–2.41 × 10^?3 mm²/s, mean 1.37 × 10^?3 mm²/s).

Conclusion

Cross-sectional imaging findings of hepatic angiosarcoma reflect the varied histopathological composition of the tumors. Multifocal disease, hemorrhage within large lesions, as well as progressive enhancement on DCE images are typical features of hepatic angiosarcoma. The mean ADC of lesions was found to be slightly elevated in comparison with other hepatic malignancies.

     

Efficacy of the American Association for the Study of Liver Disease and Barcelona criteria for the diagnosis of hepatocellular carcinoma

Objectives

Dynamic contrast-enhanced CT scan and MRI are essential for preoperative diagnosis of hepatocellular carcinoma (HCC), using the established Barcelona and AASLD criteria, which have been validated in only a few reports. The aim of this study is to retrospectively assess the diagnostic performance of these criteria in diagnosing or excluding HCC in at-risk patients with histopathology confirmation.

Methods

After institutional review board approval, a HIPAA compliant study was performed. The study cohort consisted of 156 de novo hepatic nodules imaged by either dynamic contrast-enhanced CT or MRI within 90 days of histopathology. Images were retrospectively reviewed by two abdominal radiologists blinded to clinical details, and all nodules were categorized as either meeting or not meeting AASLD and Barcelona criteria. By AASLD or Barcelona criteria, HCC was defined as any nodule greater than or equal to 1 or 2 cm, respectively, with hyperenhancement relative to background liver on arterial phase and hypoenhancement relative to background liver on portal venous or delayed phases. Significant differences in cohorts were analyzed using chi squared analysis (p < 0.05).

Results

On biopsy, 141/156 (90.38%) nodules were diagnosed as HCC. The respective sensitivity, specificity, accuracy and positive predictive value of AASLD and Barcelona were 78.7% and 63.1% (sensitivity), 73.3% and 86.7% (specificity), 78.2% and 65.4% (accuracy), and 82% and 63% (positive predictive value) (p < 0.001).

Conclusions

Using established imaging criteria, up to 21.8% of presumed HCC nodules are inaccurately characterized and many small HCC nodules remain undiagnosed.     

Abnormal findings on multiparametric prostate magnetic resonance imaging predict subsequent biopsy upgrade in patients with low risk prostate cancer managed with active surveillance

Purpose

To determine the ability of multiparametric MR imaging to predict disease progression in patients with prostate cancer managed by active surveillance.

Methods

Sixty-four men with biopsy-proven prostate cancer managed by active surveillance were included in this HIPPA compliant, IRB approved study. We reviewed baseline MR imaging scans for the presence of a suspicious findings on T2-weighted imaging, MR spectroscopic imaging (MRSI), and diffusion-weighted MR imaging (DWI). The Gleason grades at subsequent biopsy were recorded. A Cox proportional hazard model was used to determine the predictive value of MR imaging for Gleason grades, and the model performance was described using Harrell’s C concordance statistic and 95% confidence intervals (CIs).

Results

The Cox model that incorporated T2-weighted MR imaging, DWI, and MRSI showed that only T2-weighted MR imaging and DWI are independent predictors of biopsy upgrade (T2; HR = 2.46; 95% CI 1.36–4.46; P = 0.003—diffusion; HR = 2.76; 95% CI 1.13–6.71; P = 0.03; c statistic = 67.7%; 95% CI 61.1–74.3). There was an increasing rate of Gleason score upgrade with a greater number of concordant findings on multiple MR sequences (HR = 2.49; 95% CI 1.72–3.62; P < 0.001).

Conclusions

Abnormal results on multiparametric prostate MRI confer an increased risk for Gleason score upgrade at subsequent biopsy in men with localized prostate cancer managed by active surveillance. These results may be of help in appropriately selecting candidates for active surveillance.