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Radiology 04/2013; 267(1):318-9. · 5.73 Impact Factor
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Radiology 04/2013; 267(1):317-8. · 5.73 Impact Factor
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ABSTRACT: Acinar cell carcinoma (ACC) is a rare pancreatic exocrine neoplasm characterized by a huge, exophytic well-circumscribed hypovascular mass. There has been several reports describing intraductal and papillary variant of ACC and they showed different radiologic features from usual ACC. We present histologically confirmed cases of intraductal and papillary variant of ACC that had been found in two patients, who underwent CT and MRI. This report provides CT and MRI features of intraductal and papillary variant of ACC in pancreas with pathologic correlation after surgical excision.
Abdominal Imaging 03/2013; · 1.73 Impact Factor
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ABSTRACT: 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.
Abdominal Imaging 03/2013; · 1.73 Impact Factor
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ABSTRACT: PURPOSE: To compare the image quality between T1 high-resolution isotropic volume examination using the multi-echo Dixon technique (mDixon-eTHRIVE) and that using spectrally adiabatic inversion recovery (SPAIR-eTHRIVE) in gadoxetic acid-enhanced liver MRI, and to evaluate the detectability of hepatocellular carcinoma (HCC) on mDixon-eTHRIVE. MATERIALS AND METHODS: Seventy patients with 117 HCCs underwent gadoxetic acid-enhanced liver MRI using mDixon-eTHRIVE. All patients also underwent gadoxetic acid-enhanced MRI using SPAIR-eTHRIVE (mean interval of 96 days). Two radiologists performed a consensus review of MRIs for image quality, homogeneity of fat suppression, artifact, and anatomic sharpness using a four-point scale. The detectability for HCC with mDixon-eTHRIVE was assessed using alternative-free response receiver operating characteristic. RESULTS: All mDixon-eTHRIVE images received higher scores for homogeneity of fat suppression and image quality (P < 0.05) compared with those for SPAIR-eTHRIVE. With respect to artifact and anatomic sharpness, there was no significant difference between two MRIs (P > 0.05). Diagnostic accuracy (Az) and sensitivity for detecting HCCs with mDixon-eTHRIVE images were mean 0.954 and 93.2%, respectively. CONCLUSION: For gadoxetic acid-enhanced liver MRI, mDixon-eTHRIVE showed improved homogeneity of fat suppression and overall image quality compared with SPAIR-eTHRIVE. J. Magn. Reson. Imaging 2013;. © 2013 Wiley Periodicals, Inc.
Journal of Magnetic Resonance Imaging 01/2013; · 2.70 Impact Factor
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ABSTRACT: Background
Gadoxetic acid and diffusion-weighted imaging (DWI) is increasingly used for the diagnosis of hepatocellular carcinoma (HCC). It is relevant to refine the diagnostic parameters for HCC, using state-of-the-art imaging techniques.PurposeTo validate usefulness of magnetic resonance imaging (MRI) criteria with gadoxetic acid-enhanced MRI and DWI for diagnosis of small HCC by differentiation from dysplastic nodule (DN) or regenerative nodule (RN) in cirrhotic patients with strongly suspected small HCC.Material and Methods
One hundred and eight patients with 102 HCCs and 29 benign nodules including 21 DNs and two large RNs (≤ 2.0 cm), and 40 patients with no HCC underwent gadoxetic acid-enhanced MRI and DWI. All patients also underwent MDCT. Index MR criteria for HCC were: (i) arterial hyperenhancement and hypointensity on hepatobiliary phase (HBP) with hyperintensity on DWI; (ii) hypovascular nodule with hyperintensity on DWI; (iii) arterial hyperenhancement and hypointensity on HBP without hyperintensity on DWI; (iv) arterial hyperenhancement and either iso- or hyperintensity on HBP, with hyperintensity on DWI; and (v) hyperintensity only on DWI. According to these criteria, MRI findings for HCCs and benign nodules were independently classified by two reviewers.ResultsOn multidetector-row computed tomography, 64 HCCs (62.7%) showed typical features for HCC while 13 (12.8%) were not identified. On MRI, 84 HCCs (82.4%) showed arterial hyperenhancement and hypointensity on HBP, and hyperintensity on DWI. Eight HCCs were regarded as hypovascular HCCs with hyperintensity DWI (category 2). One HCC (0.6 cm in diameter) was demonstrated only by DWI. For each observer, 101 (99.0%) and 100 HCCs (98.0%) were discernible when applying all MRI criteria for HCC, respectively. Three DNs also fit the HCC criteria, thus the specificity was 90.9% for both observers.Conclusion
With the HCC criteria based on combined gadoxetic acid-enhanced MRI and DWI, it is possible to reliably diagnose small HCC including hypovascular HCCs.
Acta Radiologica 11/2012; · 1.37 Impact Factor
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ABSTRACT: OBJECTIVE: To evaluate the risk factors affecting early diffuse recurrence within 1 year of percutaneous ultrasound-guided radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). METHODS: Out of 146 patients who received transcatheter arterial chemoembolisation (TACE) for treatment of recurrent HCC after percutaneous ultrasound-guided RFA, we selected 23 patients with early diffuse recurrence. Early diffuse recurrence was defined as three or more new recurrent HCCs within 1 year of initial RFA. As a control group, we selected 23 patients, matched exactly for age and sex, in which there was no local tumour progression or new recurrence after RFA. To analyse the risk factors, we examined patient factors and tumour factors. RESULTS: Recurrent tumours occurred from 30 to 365 days after RFA (median time, 203 days). Univariate analysis indicated that larger tumour size and poorly defined margin were significant risk factors (P < 0.05). Multivariate analysis indicated that poorly defined margin was a significant risk factor (P < 0.05). CONCLUSION: Larger tumour size and poorly defined margin may be risk factors for early diffuse recurrence of HCC within 1 year of RFA. Tumours with such risk factors should be treated with a combination of TACE to minimise the potential for therapeutic failure. KEY POINTS: • Ultrasound-guided radiofrequency ablation (RFA) is widely used for hepatocellular carcinoma (HCC). • Early diffuse recurrence after RFA is an important prognostic factor • The risk factors for recurrence are larger tumour size and poorly defined margins • Tumours with such risk factors should be treated with transarterial chemoembolisation.
European Radiology 10/2012; · 3.22 Impact Factor
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ABSTRACT: OBJECTIVE: Our objective was to evaluate whether the enhancement pattern, measured by changes in the signal- (SNRs) and contrast-to-noise ratios (CNRs), of hepatocellular carcinomas (HCCs) on gadoxetic acid-enhanced MRI reflects tumor differentiation. SUBJECTS AND METHODS: Two hundred eighty-five patients with 286 surgically-confirmed HCCs who underwent gadoxetic acid-enhanced MRI were included (11 grade I, 267 grade II, 7 grade III, and 1 grade IV tumor). Unenhanced and dynamic images with a T1-weighted 3D turbo-field-echo sequence were obtained. Relative signal intensities of the tumors with respect to surrounding liver were evaluated and the SNRs and CNRs were calculated. RESULTS: SNR measurements demonstrated a fluctuating pattern (an increase in the SNR, followed by a decrease and a subsequent increase [or a decrease in the SNR followed by an increase and a subsequent decrease]) in 282 of 286 (98.6%) tumors. The SNR measurements also showed a single-peak SNR in the arterial phase (1.0% [3/286]) and 3min delayed images (0.3% [1/286]) followed by a decrease in 4 (1.4% [4/286]) grade II tumors. Nearly all tumors (88.1% [252/286]), 9 (81.8% [9/11]) grade I, 236 (88.4% [236/267]) grade II, 6 (85.7% [6/7]) grade III, and 1 (100% [1/1]) grade IV tumor showed maximum absolute CNRs with negative values, which were most commonly found in 20min delayed images (67.5% [170/252]). The remaining 34 of 286 (11.9%) tumors showed maximum absolute CNRs with positive values. CONCLUSION: Regardless of the tumor grades, the most common manifestation was a SNR with a fluctuating pattern with time and maximum absolute CNRs with negative values, which were most commonly noted in the hepatobiliary phase.
European journal of radiology 10/2012; · 2.65 Impact Factor
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ABSTRACT: To prospectively and intraindividually compare liver magnetic resonance imaging (MRI) using single-source and dual-source parallel radiofrequency (RF) transmissions at 3.0-T for image quality, lesion detectability, and lesion contrast.
Ninety-nine patients with 139 liver lesions underwent liver MRI at 3.0-T. Two radiologists performed a consensus review of T2-weighted images (T2WI), heavily T2WI (HT2WI), gadoxetic acid-enhanced hepatobiliary images, and diffusion-weighted imaging using single-source and dual-source RF transmissions with regard to image quality and lesion detectability. Contrast ratios between liver lesions and liver parenchyma were also calculated.
Image quality was better with dual-source than with single-source at T2WI and HT2WI (P < 0.05), but lesion detectabilities were similar for all sequences. There was no significant difference in mean contrast ratios for all sequences (P > 0.05).
Dual-source RF transmission provides a better image quality with T2WI and HT2WI than with single-source. However, 2 techniques showed similar lesion detectability.
Journal of computer assisted tomography 09/2012; 36(5):546-53. · 1.38 Impact Factor
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ABSTRACT: Purpose: To investigate the imaging features of hypovascular hypointense nodules on hepatobiliary phase gadoxetic acid-enhanced magnetic resonance (MR) images in patients with cirrhosis that may be associated with progression to hypervascular hepatocellular carcinoma (HCC). Materials and Methods: The institutional review board approved this retrospective study and waived informed patient consent. This study included 135 patients with a diagnosis of hepatitis B-induced liver cirrhosis and 214 hypovascular hypointense nodules on hepatobiliary phase gadoxetic acid-enhanced MR images. MR images were analyzed with respect to nodule size, degree of hypointensity at hepatobiliary phase (four grades), presence of fat, and signal intensity on T1- and T2-weighted and diffusion-weighted (DW) images. Univariate and multivariate Cox regression analyses were used to identify variables that are associated with developing hypervascular HCC. Results: On follow-up MR images, 139 nodules (65.0%) had no evidence of HCC (mean follow-up, 522 days) (group 1), but 75 (35.0%) became hypervascular HCC (mean follow-up, 388 days) (group 2). Univariable Cox analysis revealed that the degree of hypointensity on hepatobiliary phase images (P = .044 and .001) and hyperintensity on T2-weighted and DW images (P = .001 and .0001) was significantly related to the development of hypervascular HCC. According to the multivariable Cox analysis, no other variable significantly adjusted the model once hyperintensity at initial DW imaging was already included as an associated variable, (hazard ratio, 7.44; 95% confidence interval: 4.28, 12.94; P = .0001). Conclusion: Hyperintensity on DW images in hypovascular hypointense nodules on hepatobiliary phase gadoxetic acid-enhanced MR images in patients with cirrhosis is strongly associated with progression to hypervascular HCC. © RSNA, 2012.
Radiology 08/2012; 265(1):104-14. · 5.73 Impact Factor
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ABSTRACT: Background As gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) have been widely used for the evaluation of hepatocellular carcinoma (HCC), it is clinically relevant to determine the diagnostic efficacy of gadoxetic acid-enhanced MRI and DWI for detection of HCCs with respect to the severity of liver cirrhosis. Purpose To compare the diagnostic accuracy and sensitivity of gadoxetic acid-enhanced MRI and DWI for detection of HCCs with respect to the severity of liver cirrhosis. Material and Methods A total of 189 patients with 240 HCCs (≤3.0 cm) (Child-Pugh A, 81 patients with 90 HCCs; Child-Pugh B, 65 patients with 85 HCCs; Child-Pugh C, 43 patients with 65 HCCs) underwent DWI and gadoxetic acid-enhanced MRI at 3.0 T. A gadoxetic acid set (dynamic and hepatobiliary phase plus T2-weighted image) and DWI set (DWI plus unenhanced MRIs) for each Child-Pugh class were analyzed independently by two observers for detecting HCCs using receiver-operating characteristic analysis. The diagnostic accuracy and sensitivity were calculated. Results There was a trend toward decreased diagnostic accuracy for gadoxetic acid and DWI set with respect to the severity of cirrhosis (Child-Pugh A [mean 0.974, 0.961], B [mean 0.904, 0.863], C [mean 0.779, 0.760]). For both observers, the sensitivities of both image sets were highest in Child-Pugh class A (mean 95.6%, 93.9%), followed by class B (mean 83.0%, 77.1%), and class C (mean 60.6%, 60.0%) (P < 0.05). Conclusion In HCC detection, the diagnostic accuracy and sensitivity for gadoxetic acid-enhanced MRI and DWI were highest in Child-Pugh class A, followed by Child-Pugh class B, and Child-Pugh class C, indicating a tendency toward decreased diagnostic capability with the severity of cirrhosis.
Acta Radiologica 07/2012; 53(8):830-8. · 1.37 Impact Factor
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ABSTRACT: To determine if the combination of gadoxetic acid-enhanced magnetic resonance (MR) imaging and diffusion-weighted (DW) imaging helps to increase accuracy and sensitivity in the diagnosis of small hepatocellular carcinomas (HCCs) compared with those achieved by using each MR imaging technique alone.
The institutional review board approved this retrospective study and waived the requirement for informed consent. The study included 130 patients (95 men, 35 women) with 179 surgically confirmed small HCCs (≤2.0 cm) and 130 patients with cirrhosis (90 men, 40 women) without HCC who underwent gadoxetic acid-enhanced MR imaging and DW imaging at 3.0 T between May 2009 and July 2010. Three sets of images were analyzed independently by three observers to detect HCC: a gadoxetic acid set (unenhanced, early dynamic, and hepatobiliary phases), a DW imaging set, and a combined set. Data were analyzed by using alternative-free response receiver operating characteristic analysis. Diagnostic accuracy (area under the receiver operating characteristic curve [A(z)]), sensitivity, specificity, and positive predictive value were calculated.
The mean A(z) values for the combined set (0.952) were significantly higher than those for the gadoxetic acid set (A(z) = 0.902) or the DW imaging set alone (A(z) = 0.871) (P ≤ .008). On a per-lesion basis, observers showed higher sensitivity in their analyses of the combined set (range, 91.1%-93.3% [163-167 of 179]) than in those of the gadoxetic acid set (range, 80.5%-82.1% [144-147 of 179]) or the DW imaging set alone (range, 77.7%-79.9% [139-143 of 179]) (P ≤ .003). Positive predictive values and specificity for all observers were equivalent for the three imaging sets.
The combination of gadoxetic acid-enhanced MR imaging and DW imaging yielded better diagnostic accuracy and sensitivity in the detection of small HCCs than each MR imaging technique alone.
Radiology 07/2012; 264(3):761-70. · 5.73 Impact Factor
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ABSTRACT: PURPOSE: To determine the differential MRI features of small mass-forming intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC). METHODS: Sixty-four patients with pathologically proven small ICCs (n = 32) and HCCs (n = 32) (≤3.0 cm in diameter) who had undergone preoperative gadoxetic acid-enhanced MRI and DWI were enrolled in this study. Images were analyzed for the shape of the lesions, the presence of biliary dilatation, hyperenhancement (>50 % of the tumor volume) or rim enhancement on the arterial phase, capsular enhancement, and the presence of target appearance (a central enhancement with hypointense rim) on the hepatobiliary phase and on DWI (a central hypointense area with a peripheral hyperintense rim). Statistical significance of these findings was determined by the χ(2) or Fisher's exact test. Multivariate analysis was performed to identify independent imaging findings that allow differentiation of the two diseases. RESULTS: Univariate analysis revealed that the following significant parameters favor ICC over HCC: lobulating shape, rim enhancement on arterial phase, target appearance on the hepatobiliary phase, and DWI (P < 0.05). Multivariate logistic regression analysis revealed that only target appearance on the DWI was a significant and independent variable predictive of ICC, as 24 ICCs (75.0 %) and one HCC (3.1 %) showed this feature (P = 0.0003). CONCLUSION: A target appearance on the DWI was the most reliable imaging feature for distinguishing small mass-forming ICC from small HCC.
Abdominal Imaging 07/2012; · 1.73 Impact Factor
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ABSTRACT: OBJECTIVES: The goal of this study was to identify clinicoradiologic characteristics to distinguish metastatic cancer to the pancreas (MCP) from double primary pancreatic cancer (DPPC). METHODS: From 2000 to 2011, we retrospectively identified MCP and DPPC patients among patients with histories of other primary malignancies. RESULTS: A total of 94 patients with histories of other primary malignancies were histologically confirmed to have pancreatic cancer. Among them, 34 patients had MCP and 60 patients had DPPC, which were ductal adenocarcinomas. The kidney was the most common primary cancer site that metastasized to the pancreas (12, 35.3%). In the DPPC group, the stomach was the most common primary cancer site (11, 18.3%). There were 21 patients (61.8%) with metachronous pancreatic cancer in the MCP group and 29 (48.3%) in the DPPC group (P=0.210). Among the metachronous pancreatic cancer patients, the disease-free interval was 88.3months in the MCP group, and 49.6months in the DPPC group (P=0.062). The number of the patients who showed elevated CA 19-9 levels was higher in the DPPC group than in the MCP group (39 (65%) vs. 9 (26.5%); P=0.001). Total bilirubin (P=0.006) and fasting plasma glucose (P=0.050) were also higher in the DPPC group. The numbers of patients who showed pancreatic duct dilatation (P=0.002) and pancreatic atrophy (P=0.008) on radiographs were meaningfully higher in the DPPC group than in the MCP group. On the other hand, the numbers of patients who showed well demarcated tumor margin (P<0.000), tumor necrosis (P=0.002), enhancement (P=0.005) and distant metastasis (P=0.028) were significantly higher in the MCP group than in the DPPC group. We evaluated differences in survival between the two groups. The median survival time in the MCP group (55months) was significantly longer than that in the DPPC group (20months). CONCLUSIONS: Other than elevated levels of CA 19-9, total bilirubin and fasting glucose, radiologic findings were the most reliable factors for distinguishing the MCP from the DPPC.
Gastroentérologie Clinique et Biologique 06/2012; · 0.80 Impact Factor
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ABSTRACT: To examine the differential features of combined hepatocellular and cholangiocarcinoma (HCC-CC) from mass-forming intrahepatic cholangiocarcinoma (ICC) on gadoxetic acid-enhanced MRI.
Forty patients with pathologically proven combined HCC-CC (n = 20) and ICCs (n = 20) who had undergone gadoxetic acid-enhanced MRI were enrolled in this study. MR images were analyzed for the shape of lesions, hypo- or hyperintense areas on the T2-weighted image (T2WI), rim enhancement during early dynamic phases, and central enhancement with hypointense rim (target appearance) on the 10-min and 20-min hepatobiliary phase (HBP). The significance of these findings was determined by the χ(2) test.
Irregular shape and strong rim enhancement during early dynamic phases, and absence of target appearance on HBP favored combined HCC-CCs (P < 0.05). Lobulated shape, weak peripheral rim enhancement, and the presence of complete target appearance on the 10-min and 20-min HBP favored ICCs (P < 0.05). However, 10 CC-predominant type of combined HCC-CC showed complete or partial target appearance on 10-min HBP.
The shape of tumors, degree of rim enhancement during early dynamic phases, and target appearance on HBP were valuable for differentiating between combined HCC-CC and mass-forming ICC on gadoxetic acid-enhanced MRI. J. Magn. Reson. Imaging 2012;36:881-889. © 2012 Wiley Periodicals, Inc.
Journal of Magnetic Resonance Imaging 06/2012; 36(4):881-9. · 2.70 Impact Factor
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ABSTRACT: As diffusion-weighted imaging (DWI) is routinely incorporated into the standard clinical protocol, it is clinically relevant to determine whether DWI after gadoxetic acid is comparable to pre-contrast DWI, with regard to the detection and characterization of focal liver lesions.
To compare DWI before and after administration of gadoxetic acid in the detection and characterization of small (≤2.5 cm) focal hepatic lesions.
One hundred and fifty-eight patients with 237 focal hepatic lesions (≤2.5 cm) (124 HCCs, 50 metastases, 2 cholangiocarcinomas, 43 hemangiomas, and 18 cysts) were included. DWIs were obtained before and after administration of gadoxetic acid. Non-breath-hold DWI was performed with b values of 0, 100, and 800 s/mm(2). Signal-to-noise ratio (SNR), lesion-liver contrast-to-noise ratio (CNR), and apparent diffusion coefficients (ADCs) of the liver and lesion were calculated. Lesion detection with each DWI was evaluated with alternative free-response receiver-operating characteristic analysis by two observers. The sensitivity of the characterization of focal hepatic lesions as solid (malignancy) or non-solid (benignity) with each DWI was calculated using a five-point confidence scale. Inter-observer agreement regarding lesion detection and characterization was evaluated using kappa statistics.
SNRs of the liver on post-contrast DWI were significantly lower than on unenhanced DWI at b = 800 s/mm(2) (P < 0.05). SNRs, CNRs, and ADCs of focal hepatic lesions were not significantly different between two DWIs (P > 0.05). The diagnostic accuracy (Az) for lesion detection and the sensitivity for lesion characterization did not show significant difference between two DWIs (P > 0.05). With regard to the detection and characterization of focal hepatic lesions, the kappa values for two DWIs indicated good and excellent inter-observer agreement, respectively.
Gadoxetic acid-enhanced DWI showed comparable diagnostic capability to unenhanced DWI for the detection and characterization of small focal hepatic lesions.
Acta Radiologica 04/2012; 53(5):485-93. · 1.37 Impact Factor
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ABSTRACT: The objective was to determine imaging features that distinguish small (≤3cm) solid pancreatic adenocarcinoma, neuroendocrine tumor (NET) and solid pseudopapillary tumor (SPT) on gadoxetic-acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighed imaging (DWI).
Twenty-four adenocarcinomas, 10 NETs and 8 SPTs were retrospectively included. Two radiologists analyzed morphologic features, signal intensity of the tumors on MR images including DWI (b=800) and dynamic enhancement pattern with consensus. Tumor-to-parenchyma ratio and tumor apparent diffusion coefficients (ADCs) were quantitatively assessed.
All adenocarcinomas had an ill-defined margin and irregular shape, and more frequently had pancreatic duct dilatation compared with other tumors (P<.05). All SPTs and all but one of the adenocarcinomas (95.8%) had no arterial enhancement with progressively increased enhancement, whereas seven NETs (70%) had arterial enhancement with progressively decreased enhancement (P<.01). The mean value of tumor-to-parenchyma ratio on arterial and portal phases was significantly higher for NETs, and the mean value of tumor ADCs was significantly lower for SPTs than for other tumors (P<.05).
Gadoxetic-acid-enhanced MRI may aid in differentiation between small adenocarcinomas, NETs and SPTs based on morphologic features with dynamic enhancement pattern in adenocarcinomas, dynamic enhancement pattern with tumor-to-parenchyma ration on arterial and portal phases in NETs, and dynamic enhancement pattern with lower ADC value in SPTs.
Magnetic Resonance Imaging 04/2012; 30(7):916-25. · 1.99 Impact Factor
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Young Kon Kim,
Min Woo Lee,
Won Jae Lee,
Seong Hyun Kim,
Hyunchul Rhim,
Jae Hoon Lim,
Dongil Choi,
Young-sun Kim,
Kyung Mi Jang,
Soon Jin Lee,
Hyo Keun Lim
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ABSTRACT: To compare the diagnostic accuracy and sensitivity of combined gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) with each imaging approach alone for detecting small hepatic metastases (≤ 1.5 cm).
Institutional review board approved this retrospective study and waived informed patient consent. Eighty-six patients with 179 liver metastases underwent liver MRI including unenhanced and gadoxetic acid-enhanced imaging and DWI at 3.0 T. Three image sets including unenhanced images-gadoxetic acid set (early dynamic and hepatocyte phase), DWI set, and the combined set-were analyzed independently and in consensus by 2 observers for detecting liver metastases using receiver operating characteristic analysis.
There was a tendency toward an increased diagnostic accuracy for the combined set (mean, 0.965) compared with that for each image set alone (mean, 0.911 for gadoxetic acid set; 0.926 for DWI set). The combined set showed better sensitivity (mean, 97.47%/95.0%: values on per-lesion/per-patient basis) than each imaging set alone (mean, 90.7%/83.7% for gadoxetic acid set; 91.6%/83.0% for DWI set) (P < 0.05) on both per-lesion basis and per-patient basis. All image sets showed similar positive predictive values.
The combination of gadoxetic acid-enhanced MRI and DWI yielded better diagnostic accuracy and sensitivity in the detection of small liver metastasis than each magnetic resonance scan sequence alone.
Investigative radiology 03/2012; 47(3):159-66. · 4.85 Impact Factor
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ABSTRACT: To examine the differential features of focal eosinophilic liver disease (FELD) from liver metastases on gadoxetic acid-enhanced MRI.
Twenty patients with 41 FELD and 20 patients with 55 metastases were enrolled in this study. Liver MRI consisted of precontrast 2D T1-weighted image (T1WI) and gadoxetic acid-enhanced 3D T1WI (arterial, portal, 20 min hepatocyte-selective phases), and a postcontrast T2WI. Images were analyzed for the margin and shape of the lesions; lesion conspicuity on T1- and T2WI; signal intensity of the lesions on 3D T1WI; presence of rim enhancement and misty signs; and presence of significant smaller lesions on the unenhanced T1WI (<50%) compared to hepatocyte phase image.
Univariate analysis revealed the following significant parameters to favor FELD: a fuzzy margin, irregular shape, subtle signal intensity changes on T1- and T2WI, absence of target signs on the hepatocyte phase image, presence of misty signs, and size discrepancies on T1WI and hepatocyte phase images. Multivariate analysis revealed only a significantly smaller lesion size on T1WI compared to hepatocyte phase images to be predictive of FELD.
A significantly smaller lesion size on T1WI relative to hepatocyte phase image is the best predictor for identifying FELD on gadoxetic acid-enhanced MRI.
Abdominal Imaging 08/2011; 36(4):425-32. · 1.73 Impact Factor
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Liver international: official journal of the International Association for the Study of the Liver 04/2011; 31(4):541. · 3.82 Impact Factor
