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Objective: This study was designed to compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with gadobenate dimeglumine-enhanced MRI for preoperatively detecting hepatocellular carcinoma (HCC)., Materials and Methods: Eighteen consecutive patients (17 men and one woman, age range: 31-73 years) with 22 HCCs underwent examinations with gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI on a 3.0-Tesla unit. The diagnosis of HCC was established after surgical resection and pathological conformation. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC was assessed by performing an alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive values were evaluated., Results: The average value of the area under the ROC curve (Az) for gadoxetic acid enhanced MRI (0.887) was not significantly different from the Az (0.899) for gadobenate dimeglumine-enhanced MRI (p > 0.05). The overall sensitivities of gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI were 80% and 83%, respectively, with no significant difference (p > 0.05). The differences of the positive predictive values for the two contrast agents for each observer were not statistically significant (p > 0.05)., Conclusion: The diagnostic performance of gadoxetic acid-enhanced MRI and gadobenate dimeglumine-enhanced MRI for preoperatively detecting HCC is quite similar.

Objective: We compared the diagnostic performance of gadoxetic acid-enhanced MRI with that of triple-phase 16-, 40-, and 64-MDCT in the preoperative detection of hepatocellular carcinoma (HCC)., Subjects and Methods: Sixty-two consecutively registered patients (54 men, eight women; age range, 31-67 years) with 83 HCCs underwent triple-phase (arterial, portal venous, equilibrium) CT at 16-, 40-, or 64-MDCT and gadoxetic acid-enhanced 3-T MRI. The diagnosis of HCC was established after surgical resection. Three observers independently and randomly reviewed the MR and CT images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques in the detection of HCC was assessed with alternative free response receiver operating characteristic (ROC) analysis. Sensitivity, positive and negative predictive values, and sensitivity according to tumor size were evaluated., Results: For each observer, the areas under the ROC curve were 0.971, 0.959, and 0.967 for MRI and 0.947, 0.950, and 0.943 for CT. The differences were not statistically significant between the two techniques for each observer (p > 0.05). The differences in sensitivity and positive and negative predictive values between the two techniques for each observer were not statistically significant (p > 0.05). Among 10 HCCs 1 cm in diameter or smaller, each of the observers detected seven tumors with MRI. With CT, one observer detected five, one observer detected four, and one observer detected three HCCs with no statistically significant difference (p > 0.05)., Conclusion: Gadoxetic acid-enhanced MRI and triple-phase MDCT have similar diagnostic performance in the preoperative detection of HCC, but MRI may be better than MDCT in the detection of HCC 1 cm in diameter or smaller.

Objective: To compare diagnostic performance of ferucarbotran-enhanced 3.0-T magnetic resonance (MR) imaging using parallel imaging technique with that of triple-phase multidetector row computed tomography (MDCT) for the preoperative detection of hepatocellular carcinoma (HCC)., Methods: Eighty-six consecutive patients with a total of 128 surgically proven HCCs were enrolled in this study. All patients underwent ferucarbotran-enhanced 3.0-T MR imaging using parallel imaging technique and triple-phase MDCT before hepatic resection. Three experienced radiologists independently analyzed each images on a segment-by-segment basis. The accuracy of these techniques for the detection of HCC was assessed by performing a receiver operating characteristic (ROC) analysis of 104 resected hepatic segments with at least 1 HCC and 113 resected hepatic segments without HCC., Results: The mean value of the area under the ROC curve (Az) of the ferucarbotran-enhanced 3.0-T MR imaging (0.990) was significantly higher than that of the triple-phase MDCT (0.964) (P = 0.00). The mean sensitivity of the ferucarbotran-enhanced 3.0-T MR imaging (98.1%) was significantly higher than that of the triple-phase MDCT (92.9%) (P = 0.00). The higher sensitivity was largely attributable to a greater ability of the 3.0-T MR imaging to detect small HCC (< or =1 cm) (92.6% in 3.0-T MR imaging and 37.0% in MDCT; P = 0.00). No significant difference was found for their mean specificities (98.2% in 3.0-T MR imaging and 97.6% in MDCT; P = 0.86)., Conclusions: Ferucarbotran-enhanced 3.0-T MR imaging using parallel imaging technique is a more accurate diagnostic tool than triple-phase MDCT for the preoperative detection of HCC. Ferucarbotran-enhanced 3.0-T MR imaging has a higher sensitivity than triple-phase MDCT, especially for small HCCs (< or =1 cm).

Objective: To compare prospectively between 3-T magnetic resonance imaging (MRI) and multidetector row computed tomography (MDCT) for the local staging of rectal cancer., Materials and Methods: During a recent 8-month period, both 3-T MRI with a phased array coil and MDCT scanner were used to preoperatively examine 31 consecutive patients. Preoperatively, the 3 experienced reviewers independently assessed the MRI and MDCT findings for the depth of tumor invasion into the rectal wall (T). Regional lymph node metastasis (N) was assessed by the 3 reviewers working in consensus. For T staging, we used a modified T staging ( 0.05)., Conclusions: For local staging of rectal cancer, 3-T MRI is more accurate than MDCT for determining the depth of tumor invasion and the extent of lymph node metastasis.

Objective: The aim of this study was to compare phased-array 3-T MRI and endorectal sonography in the preoperative staging of rectal cancer., Materials and Methods: During an 8-month period, 24 patients with rectal cancer underwent both 3-T MRI performed with phased-array coils and 7.5- to 10-MHz endorectal sonography in the 3 weeks before surgical resection. Three radiologists independently reviewed the MR and endorectal sonographic images. The histopathologic findings in resected specimens were used to evaluate the sensitivities and specificities of these techniques for invasion of the muscularis propria and perirectal tissue and for lymph node involvement. Receiver operating characteristic (ROC) analysis was used to compare the diagnostic accuracies of the techniques., Results: For muscularis propria invasion, the mean sensitivities of both MRI and endorectal sonography were 100%, and the mean specificities were 66.7% and 61.1%, respectively. The differences in the mean sensitivities and specificities were not statistically significant (p > 0.05 in each case). For perirectal tissue invasion, MRI and endorectal sonography had comparable sensitivities and specificities (91.1% vs 100%, 92.6% vs 81.5%; p > 0.05 in each case). They also had similar sensitivities and specificities for lymph node involvement (63.6% vs 57.6%, 92.3% vs 82.1%; p > 0.05 in each case). ROC curves for muscularis propria invasion and lymph node involvement showed no differences in diagnostic accuracy. The mean area under the ROC curve for endorectal sonography (A(Z) = 0.996) for perirectal tissue invasion, however, showed higher accuracy than that of MRI (A(Z) = 0.938, p = 0.028)., Conclusion: The sensitivity, specificity, and accuracy of 3-T MRI were similar to those of endorectal sonography for muscularis propria invasion and lymph node involvement, but for perirectal tissue invasion, 3-T MRI was less accurate than endorectal sonography.

Purpose: To verify changes in the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of hypervascular hepatocellular carcinomas (HCCs) on ferucarbotran-enhanced dynamic T1-weighted MR imaging., Materials and Methods: Fifty-two patients with 61 hypervascular HCCs underwent ferucarbotran-enhanced dynamic MR imaging, and then hepatic resection. Hypervascular HCCs were identified when definite enhancement was noted during the arterial dominant phase of three-phase MDCT. Dynamic MR Images with T1-weighted fast multiplanar spoiled gradient-recalled echo sequence (TR200/TE4.2) were obtained before and 20 s, and 1, 3, 5, and 10 min, after bolus injection of ferucarbotran. We estimated the signal intensities of tumors and livers, and calculated the SNRs and CNRs of the tumors., Results: On ferucarbotran-enhanced dynamic MR imaging, SNR measurements showed a fluctuating pattern, namely, an increase in SNR followed by a decrease and a subsequent increase (or a decrease in SNR followed by a increase and a subsequent decrease) in 50 (82.0%) of 61 tumors, a single-peak SNR pattern (highest SNR on 20 s, 1, 3, or 5 min delayed images followed by a decrease) in seven (11.5%), and a decrease in SNR followed by an increase in four (6.6%). Maximum absolute CNRs with positive value were noted on 10 min delayed images in 41 (67.2%) tumors, and maximum absolute CNRs with negative value were observed on 20 s delayed images in 12 (19.7%) and on 1 min delayed images in eight (13.1%)., Conclusion: Despite showing various SNR and CNR changes, the majority of hypervascular HCCs demonstrated a fluctuating SNR pattern on ferucarbotran-enhanced dynamic MR imaging and a highest CNR on 10 min delayed image, which differed from the classic enhancement pattern on multiphasic CT.

Objective: To compare the diagnostic performance of a variety of magnetic resonance imaging (MRI) sequences, in order to identify the most effective ferucarbotran-enhanced sequence for the detection of multiple small hepatic VX2 carcinomas in rabbits., Methods: Fifteen rabbits with experimentally induced 135 VX2 carcinomas in the liver underwent ferucarbotran-enhanced MRI using the following nine pulse sequences: a fat-suppressed fast spin-echo (FSE) sequence with two echo times (TE) (proton density- and T2-weighted images), four different T2*-weighted fast multiplanar GRASS (gradient-recalled acquisition in the steady state) (FMPGR) with the combination of three TEs (9, 12, 15 ms, respectively) and two flip angles (20 degrees , 80 degrees, respectively), T2*-weighted fast multiplanar spoiled GRASS (FMPSPGR), T1-weighted FMPSPGR, and dynamic T1-weighted FMPSPGR. All images were reviewed by three radiologists with quantitative and qualitative analysis., Results: Tumor-to-liver contrast-to-noise ratio of the proton density-weighted FSE sequence was significantly higher than those of the others (p<0.05). The lesion conspicuities of proton density- and T2-weighted FSE and T2*-weighted FMPGR (TE/flip angle, 9/20 degrees and 12/20 degrees ) images were better and the image artifacts of T2*-weighted FMPGR (TE/flip angle, 15/20 degrees and 12/80 degrees ) and T2*-weighted FMPSPGR images were more prominent than those of the others (p<0.05). The lesion detection in T2- and proton density-weighted FSE and T2*-weighted FMPGR (TE/flip angle, 12/20 degrees ) images were superior to those of the others and for the detection of very small hepatic tumors of less than 5 mm, the sensitivities of these sequences were less than 30%., Conclusion: Ferucarbotran-enhanced T2- and proton density-weighted FSE and T2*-weighed FMPGR (TE/flip angle, 12/20 degrees ) images were found to be the most effective pulse sequences for the detection of multiple small hepatic VX2 carcinomas but these sequences were limited in the detection of very small hepatic tumors of less than 5 mm in size.

The purpose of this study was to evaluate the accuracy of 3-Tesla magnetic resonance imaging (MRI) for the preoperative staging of rectal cancer. Thirty-five patients with a primary rectal cancer who underwent preoperative 3-T MRI using a phased-array coil and had a surgical resection were enrolled in the study group. Preoperatively, three experienced radiologists independently assessed the T and N staging. A confidence level scoring system was used to determine if there was any perirectal invasion, and receiver operating characteristic (ROC) curves were generated. The interobserver agreement was estimated using kappa statistics. The overall accuracy rate of T staging for rectal cancer was 92%. The diagnostic accuracy was 97% for T1, 89% for T2 and 91% for T3, respectively. The predictive accuracy for perirectal invasion by the three observers was high (Az>0.92). The interobserver agreement for T staging was moderate to substantial. The overall sensitivity, specificity, and accuracy for the detection of mesorectal nodal metastases were 80%, 98%, and 95%, respectively. In conclusion, preoperative 3-T MRI using a phase-array coil accurately indicates the depth of tumor invasion for rectal cancer with a low variability.

Objective: We compared ferucarbotran-enhanced MRI with triple-phase MDCT for the preoperative detection of hepatocellular carcinoma., Subjects and Methods: Seventy-three consecutive patients with 121 hepatocellular carcinomas underwent ferucarbotran-enhanced MRI, including a dynamic study, and triple-phase MDCT before hepatic resection. The diagnosis of hepatocellular carcinoma was confirmed in all patients by means of pathologic examination after surgical resection. Three experienced radiologists independently reviewed the MR and CT images on a segment-by-segment basis. The accuracy of these techniques for the detection of hepatocellular carcinoma was assessed by conducting a receiver operating characteristic (ROC) analysis of the observations of 88 resected hepatic segments with at least one hepatocellular carcinoma each and 121 resected hepatic segments without hepatocellular carcinoma., Results: The mean values of the area under the ROC curve (A(z)) for ferucarbotran-enhanced MRI and triple-phase MDCT for all observers were 0.947 and 0.949, respectively; the difference between these two values was not statistically significant (p = 0.799). The mean sensitivities of MRI and triple-phase MDCT were 90.2% and 91.3%, respectively, and their mean specificities were 97.0% and 95.3%, respectively. The differences in the mean sensitivities and specificities of these two imaging techniques were not statistically significant (p > 0.05 in each case)., Conclusion: Ferucarbotran-enhanced MRI seems to be as accurate as triple-phase MDCT for the preoperative detection of hepatocellular carcinoma.

Purpose: To compare ferumoxides-enhanced magnetic resonance (MR) imaging with triple-phase helical computed tomography (CT) for the preoperative depiction of hepatocellular carcinoma (HCC)., Materials and Methods: Seventy consecutive patients with a total of 79 HCC nodules underwent ferumoxides-enhanced MR imaging and triple-phase helical CT before surgery. The diagnosis of HCC was established by means of pathologic examination after surgical resection in all patients. MR images obtained with all sequences and triple-phase helical CT images were reviewed independently by three radiologists on a segment-by-segment basis. Accuracy for diagnosis of HCC was assessed by applying receiver operating characteristic (ROC) analysis to observations of 78 hepatic segments with at least one HCC nodule and 70 segments without HCC., Results: The diagnostic accuracy of findings at ferumoxides-enhanced MR imaging (with mean area-under-the-ROC-curve [A(z)] values for the three observers of 0.986, 0.979, and 0.980) was significantly higher (P <.001) than that of findings at triple-phase helical CT (with mean A(z) values for the three observers of 0.945, 0.948, and 0.964). The mean sensitivity of MR imaging (95%, 222 of 234 segments) was also significantly higher than that of triple-phase helical CT (88%, 205 of 234 segments) (P =.001, McNemar test). The mean specificity was 97% (261 of 270 segments) for MR imaging and 98% (264 of 270 segments) for CT, but this difference was not significant (P =.754, McNemar test)., Conclusion: Ferumoxides-enhanced MR imaging is superior to triple-phase helical CT for the preoperative depiction of HCC., (Copyright RSNA, 2003)

Objective: The purpose of our study was to compare the diagnostic accuracy and lesion conspicuity of ferumoxides-enhanced MR imaging with those of mangafodipir trisodium-enhanced MR imaging for the preoperative detection of hepatocellular carcinoma., Subjects and Methods: Twenty-one patients with 39 hepatocellular carcinomas underwent ferumoxides-enhanced and mangafodipir trisodium-enhanced MR imaging. The diagnosis was established by pathologic examination after surgical resection in all patients. Five MR sequences were obtained 30 min after ferumoxides administration, and two MR sequences were obtained before and 15 min after mangafodipir trisodium administration. Three observers independently interpreted both MR images of all sequences on a segment-by-segment basis. The diagnostic accuracy of MR imaging was assessed using receiver operating characterizing analysis. Lesion (hepatocellular carcinoma > 10 mm in diameter)-to-liver contrast-to-noise ratio was calculated on MR images., Results: Ferumoxides-enhanced MR imaging (A(z) = 0.971) was significantly more accurate (p < 0.05) than mangafodipir trisodium-enhanced MR imaging (A(z) = 0.950). The mean sensitivity of ferumoxides-enhanced MR imaging (86%) was significantly greater (p < 0.05) than that of mangafodipir trisodium-enhanced MR imaging (44%) in lesions smaller than 10 mm. The mean lesion-to-liver contrast-to-noise ratio of hepatocellular carcinoma on ferumoxides-enhanced MR imaging (13.7 +/- 8.8) was significantly greater than on mangafodipir trisodium-enhanced MR imaging (5.4 +/- 5.1) (p < 0.01)., Conclusion: Ferumoxides-enhanced MR imaging has superior diagnostic accuracy in lesions smaller than 10 mm and superior lesion conspicuity compared with mangafodipir trisodium-enhanced MR imaging for the preoperative detection of hepatocellular carcinoma.

Objective: To identify the optimal pulse sequence for ferumoxides-enhanced magnetic resonance (MR) imaging in the detection of hepatocelluar carcinomas (HCCs)., Materials and Methods: Sixteen patients with 25 HCCs underwent MR imaging following intravenous infusion of ferumoxides. All MR studies were performed on a 1.5-T MR system, using a phased-array coil. Ferumoxides (Feridex IV) at a dose of 15 micromol/Kg was slowly infused intravenously, and axial images of seven sequences were obtained 30 minutes after the end of infusion. The MR protocol included fast spin-echo (FSE) with two echo times (TR3333-8571/TE18 and 90-117), singleshot FSE (SSFSE) with two echo times (TRinfinity/TE39 and 98), T2*-weighted gradient- recalled acquisition in the steady state (GRASS) (TR216/TE20), T2*-weighted fast multiplanar GRASS (FMPGR) (TR130/TE8.4-9.5), and T2*-weighted fast multiplanar spoiled GRASS (FMPSPGR) (TR130/TE8.4-9.5). Contrast-to-noise ratios (CNRs) of HCCs determined during the imaging sequences formed the basis of quantitative analysis, and images were qualitatively assessed in terms of lesion conspicuity and image artifacts. The diagnostic accuracy of all sequences was assessed using receiver operating characteristic (ROC) analysis., Results: Quantitative analysis revealed that the CNRs of T2*-weighted FMPGR and T2*-weighted FMPSPGR were significantly higher than those of the other sequences, while qualitative analysis showed that image artifacts were prominent at T2*-weighted GRASS imaging. Lesion conspicuity was statistically significantly less clear at SSFSE imaging. In term of lesion detection, T2*-weighted FMPGR, T2*- weighted FMPSPGR, and proton density FSE imaging were statistically superior to the others., Conclusion: T2*-weighted FMPGR, T2*- weighted FMPSPGR, and proton density FSE appear to be the optimal pulse sequences for ferumoxidesenhanced MR imaging in the detection of HCCs.