OBJECTIVE: To retrospectively evaluate the relationship between T2 values of pre- and post-contrast magnetic resonance (MR) images of femoral cartilage in patients with varying degrees of osteoarthritis. MATERIALS AND METHODS: A total of 19 patients underwent delayed gadolinium-enhanced MRI of cartilage. Six regions of interest for T2 value measurement were obtained from pre- and post-contrast T2-weighted, sagittal, multi-slice, multi-echo, source images in each subject. Regions with modified Noyes classification grade 2B and 3 were excluded. Comparison of T2 values between pre- and post-contrast images and T2 values among regions with the grade 0, 1 and 2A groups were statistically analyzed. RESULTS: Of a total of 114 regions, 79 regions showing grade 0 (n = 46), 1 (n = 18), or 2A (n = 15) were analyzed. The overall and individual T2 values of post-contrast images were significantly lower than those of pre-contrast images (overall, 35.3 +/- 9.2 [mean +/- SD] vs. 29.9 +/- 8.2, p < 0.01; range of individual, 28.9-37.6 vs. 27.1-36.4, p < 0.01). Pearson correlation coefficients showed a strong positive correlation between pre- and post-contrast images (rho-Pearson = 0.712-0.905). T2 values of pre- and post-contrast images of the grade 0 group were significantly lower than those of the grade 1/2A group (pre T2, p = 0.003; post T2, p = 0.006). CONCLUSION: T2 values of the femoral cartilage of the knee joint are significantly lower on post-contrast images than on pre-contrast images. Furthermore, these T2 values have a strong positive correlation between pre- and post-contrast images.
Adult ; Aged ; *Cartilage, Articular/pathology ; Contrast Media/*diagnostic use ; Female ; Femur ; Gadolinium DTPA/diagnostic use ; Humans ; Knee Joint ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Osteoarthritis, Knee/*diagnosis/pathology ; Retrospective Studies

OBJECTIVE: To compare gadoxetic acid injection rates of 0.5 mL/s and 1 mL/s for hepatic arterial-phase magnetic resonance (MR) imaging. MATERIALS AND METHODS: In this prospective study, 101 consecutive patients with suspected focal liver lesions were included and randomly divided into two groups. Each group underwent dynamic liver MR imaging using a 3.0-T scanner after an intravenous injection of gadoxetic acid at rates of either 0.5 mL/s (n = 50) or 1 mL/s (n = 51). Arterial phase images were analyzed after blinding the injection rates. The signal-to-noise ratios (SNRs) of the liver, aorta, portal vein, hepatic vein, spleen, and pancreas were measured. The contrast-to-noise ratios (CNRs) of the hepatocellular carcinomas (HCC) were calculated. Finally, two experienced radiologists were independently asked to identify, if any, HCCs in the liver on the images and score the image quality in terms of the presence of artifacts and the proper enhancement of the liver, aorta, portal vein, hepatic vein, hepatic artery, spleen, pancreas, and kidney. RESULTS: The SNRs were not significantly different between the groups (p = 0.233-0.965). The CNRs of the HCCs were not significantly different (p = 0.597). The sensitivity for HCC detection and the image quality scores were not significantly different between the two injection rates (p = 0.082-1.000). CONCLUSION: Image quality and sensitivity for hepatic HCCs of arterial-phase gadoxetic acid-enhanced MR were not significantly improved by reducing the contrast injection rate to 0.5 mL/s compared with 1 mL/s.
Adult ; Aged ; Aged, 80 and over ; Artifacts ; Carcinoma, Hepatocellular/*radiography ; Contrast Media/*administration & dosage/*diagnostic use ; Dose-Response Relationship, Drug ; Female ; Gadolinium DTPA/*administration & dosage/*diagnostic use ; Hepatic Artery ; Humans ; Liver Neoplasms/*radiography ; *Magnetic Resonance Imaging ; Male ; Middle Aged ; Prospective Studies ; Sensitivity and Specificity ; Signal-To-Noise Ratio

PURPOSE: To investigate whether histogram analysis of the hepatobiliary phase on gadoxetate enhanced-MRI could be used as a quantitative index for determination of liver cirrhosis. MATERIALS AND METHODS: A total of 63 patients [26 in a normal liver function (NLF) group and 37 in a cirrhotic group] underwent gadoxetate-enhanced MRI, and hepatobiliary phase images were obtained at 20 minutes after contrast injection. The signal intensity of the hepatic parenchyma was measured at four different regions of interest (ROI) of the liver, avoiding vessels and bile ducts. Standard deviation (SD), coefficient of variation (CV), and corrected CV were calculated on the histograms at the ROIs. The distributions of CVs calculated from the ROI histogram were examined and statistical analysis was carried out. RESULTS: The CV value was 0.041+/-0.009 (mean CV+/-SD) in the NLF group, while that of cirrhotic group was 0.071+/-0.020. There were statistically significant differences in the CVs and corrected CV values between the NLF and cirrhotic groups (p<0.001). The most accurate cut-off value among CVs for distinguishing normal from cirrhotic group was 0.052 (sensitivity 83.8% and specificity 88.5%). There was no statistically significant differences in SD between NLF and cirrhotic groups (p=0.307). CONCLUSION: The CV of histograms of the hepatobiliary phase on gadoxetate-enhanced MRI may be useful as a quantitative value for determining the presence of liver cirrhosis.
Adult ; Aged ; Aged, 80 and over ; Contrast Media/diagnostic use ; Female ; Gadolinium DTPA/diagnostic use ; Humans ; Liver Cirrhosis/*diagnosis ; Magnetic Resonance Imaging/methods ; Male ; Middle Aged ; Retrospective Studies ; Young Adult

This study describes the first case of biliary peritonitis after radiofrequency ablation diagnosed by magnetic resonance (MR) imaging with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA), a hepatocyte-specific MR imaging contrast agent. The image acquired 300 minutes after the administration of Gd-EOB-DTPA was useful to make a definite diagnosis and to identify the pathway of bile leakage. It is important to decide on the acquisition timing with consideration of the predicted location of bile duct injury.
Aged, 80 and over ; Bile Duct Diseases/*diagnosis/etiology ; Carcinoma, Hepatocellular/diagnosis/surgery ; Catheter Ablation/*adverse effects ; Contrast Media/diagnostic use ; Diagnosis, Differential ; Follow-Up Studies ; Gadolinium DTPA/*diagnostic use ; Hepatectomy/adverse effects/methods ; Humans ; Liver Neoplasms/diagnosis/*surgery ; Magnetic Resonance Imaging/*methods ; Male ; Peritonitis/*diagnosis/etiology

OBJECTIVE: To compare the diagnostic performance in evaluating the response of neoadjuvant chemotherapy (NAC), between the response evaluation criteria in solid tumor (RECIST) 1.0 and RECIST 1.1, on magnetic resonance imaging (MRI) for advance breast cancer patients. MATERIALS AND METHODS: Breast cancer patients, who underwent NAC between 2005 and 2010, were included. Both prechemotherapy and post-chemotherapy MRIs were performed within 1-4 weeks before and after NAC. Only the patients with subsequent surgery were included. The response to NAC was assessed by using RECIST 1.0 and RECIST 1.1. Patients with a complete or partial response on MRI were considered as responders, and those with stable or progressive disease were considered as non-responders. Tumor necrosis > 50% on pathology was defined as responders and necrosis < 50% was defined as non-responders. The diagnostic accuracy of both RECIST 1.0 and RECIST 1.1 was analyzed and compared by receiver operating characteristic curve analysis. RESULTS: Seventy-nine females (mean age 51.0 +/- 9.3 years) were included. Pathology showed 45 responders and 34 non-responders. There were 49 responders and 30 non-responders on RECIST 1.0, and in 55 patients, RECIST 1.0 results agreed with pathologic results (69.6%). RECIST 1.1 showed 52 responders and 27 non-responders. In 60 patients, RECIST 1.1 results were in accordance with pathology results (75.9%). The area under the ROC curve was 0.809 for RECIST 1.0 and 0.853 for RECIST 1.1. CONCLUSION: RECIST 1.1 showed better diagnostic performance than RECIST 1.0, although there was no statistically significant difference between the two.
Breast Neoplasms/*drug therapy/*pathology/surgery ; Chemotherapy, Adjuvant ; Contrast Media/diagnostic use ; Female ; Gadolinium DTPA/diagnostic use ; Humans ; Magnetic Resonance Imaging/*methods ; Middle Aged ; Neoadjuvant Therapy ; Predictive Value of Tests ; ROC Curve ; Sensitivity and Specificity ; Statistics, Nonparametric ; Survival Analysis ; Treatment Outcome

No abstract available.
Antigens, CD34/metabolism ; Carcinoma, Hepatocellular/pathology/*radiography ; Contrast Media/chemistry/diagnostic use ; Gadolinium DTPA/chemistry/*diagnostic use ; Humans ; Immunohistochemistry ; Liver Neoplasms/pathology/*radiography ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Tomography, X-Ray Computed

A 64-year-old male patient with liver cirrhosis underwent a CT study for hepatocellular carcinoma surveillance, which demonstrated a 1.4-cm hypervascular subcapsular tumor in the liver. On gadoxetic acid-enhanced MRI, the tumor showed brisk arterial enhancement and persistent hyperenhancement in the portal phase, but hypointensity in the hepatobiliary phase. On diffusion-weighted MRI, the tumor showed an apparent diffusion coefficient twofold greater than that of the background liver parenchyma, which suggested that the lesion was benign. The histologic diagnosis was intrahepatic bile duct adenoma with alcoholic liver cirrhosis.
Adenoma, Bile Duct/*diagnosis/etiology ; Bile Duct Neoplasms/*diagnosis/etiology ; *Bile Ducts, Intrahepatic ; Contrast Media/diagnostic use ; Diagnosis, Differential ; Diffusion Magnetic Resonance Imaging/*methods ; Gadolinium DTPA/diagnostic use ; Humans ; Liver Cirrhosis/*complications/diagnosis ; Male ; Middle Aged

OBJECTIVE: To compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance (MR) imaging with that of triple-phase multidetector-row computed tomography (MDCT) in the detection of liver metastasis. MATERIALS AND METHODS: Our institutional review board approved this retrospective study and waived informed consent. The study population consisted of 51 patients with hepatic metastases and 62 patients with benign hepatic lesions, who underwent triple-phase MDCT and gadoxetic acid-enhanced MRI within one month. Two radiologists independently and randomly reviewed MDCT and MRI images regarding the presence and probability of liver metastasis. In order to determine additional value of hepatobiliary-phase (HBP), the dynamic-MRI set alone and combined dynamic-and-HBP set were evaluated, respectively. The standard of reference was a combination of pathology diagnosis and follow-up imaging. For each reader, diagnostic accuracy was compared using the jackknife alternative free-response receiver-operating-characteristic (JAFROC). RESULTS: For both readers, average JAFROC figure-of-merit (FOM) was significantly higher on the MR image sets than on the MDCT images: average FOM was 0.582 on the MDCT, 0.788 on the dynamic-MRI set and 0.847 on the combined HBP set, respectively (p < 0.0001). The differences were more prominent for small (< or = 1 cm) lesions: average FOM values were 0.433 on MDCT, 0.711 on the dynamic-MRI set and 0.828 on the combined HBP set, respectively (p < 0.0001). Sensitivity increased significantly with the addition of HBP in gadoxetic acid-enhanced MR imaging (p < 0.0001). CONCLUSION: Gadoxetic acid-enhanced MRI shows a better performance than triple-phase MDCT for the detection of hepatic metastasis, especially for small (< or = 1 cm) lesions.
Adult ; Aged ; Aged, 80 and over ; Contrast Media/diagnostic use ; Diagnosis, Differential ; Female ; Gadolinium DTPA/*diagnostic use ; Humans ; Liver Neoplasms/*diagnosis/secondary ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Multidetector Computed Tomography/methods ; ROC Curve ; Retrospective Studies

OBJECTIVE: We aimed to evaluate the use of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) at 3.0 T for differentiating the benign from malignant soft tissue tumors. Also we aimed to assess whether the shorter length of DCE-MRI protocols are adequate, and to evaluate the effect of temporal resolution. MATERIALS AND METHODS: Dynamic contrast-enhanced magnetic resonance imaging, at 3.0 T with a 1 second temporal resolution in 13 patients with pathologically confirmed soft tissue tumors, was analyzed. Visual assessment of time-signal curves, subtraction images, maximal relative enhancement at the first (maximal peak enhancement [Emax]/1) and second (Emax/2) minutes, Emax, steepest slope calculated by using various time intervals (5, 30, 60 seconds), and the start of dynamic enhancement were analyzed. RESULTS: The 13 tumors were comprised of seven benign and six malignant soft tissue neoplasms. Washout on time-signal curves was seen on three (50%) malignant tumors and one (14%) benign one. The most discriminating DCE-MRI parameter was the steepest slope calculated, by using at 5-second intervals, followed by Emax/1 and Emax/2. All of the steepest slope values occurred within 2 minutes of the dynamic study. Start of dynamic enhancement did not show a significant difference, but no malignant tumor rendered a value greater than 14 seconds. CONCLUSION: The steepest slope and early relative enhancement have the potential for differentiating benign from malignant soft tissue tumors. Short-length rather than long-length DCE-MRI protocol may be adequate for our purpose. The steepest slope parameters require a short temporal resolution, while maximal peak enhancement parameter may be more optimal for a longer temporal resolution.
Adult ; Aged ; Aged, 80 and over ; Contrast Media/diagnostic use ; Diagnosis, Differential ; Female ; Gadolinium DTPA/diagnostic use ; Humans ; Image Interpretation, Computer-Assisted/methods ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Soft Tissue Neoplasms/*pathology ; Statistics, Nonparametric ; Subtraction Technique

OBJECTIVE: To evaluate the temporal evolution and diagnostic values of the diffusion tensor imaging (DTI) and the high b value diffusion weighted imaging (DWI) in the early permanent and transient cerebral ischemia. MATERIALS AND METHODS: For permanent or 30-minute transient-ischemia induced 30 rats, DTI and DWIs at both high b (b = 3000 s/mm2) and standard b value (b = 1000 s/mm2) were obtained at the following conditions: at 15, 30, 45, 60 minutes after the occlusion of what for hyperacute permanent ischemia; at 1, 3, 5, 7, 9 hours after the occlusion for acute permanent ischemia; and at 15 minutes before reperfusion, 0.5, 2.5, and 24 hours after reperfusion for transient ischemia. The diffusion parameters and their ratios were obtained and compared between different b values, and among different time points and groups, respectively. RESULTS: For both b values, the apparent diffusion coefficient (ADC) ratio decreased for first three hours, and then slightly increased until 9 hours after the occlusion during a gradual continuous increase of DWI signal intensity (SI) ratio, with excellent correlation between ADC ratios and DWI SI ratios. The DWI showed a higher contrast ratio, but the ADC map showed a lower contrast ratio for permanent ischemia at high b value than at standard b value. Fractional anisotropy (FA) increased for 1 hour, then gradually decreased until 9 hours after the occlusion in permanent ischemia and showed transient normalization and secondary decay along with change in ADC in transient ischemia. CONCLUSION: This study presents characteristic initial elevation and secondary decay of FA, higher contrast ratio of DWI, and lower contrast ratio of ADC map at high b value, in addition to the time evolutions of diffusion parameters in early permanent and transient ischemia.
Animals ; Contrast Media/diagnostic use ; Diffusion Magnetic Resonance Imaging/*methods ; Gadolinium DTPA/diagnostic use ; Ischemic Attack, Transient/*diagnosis ; Male ; Rats ; Rats, Sprague-Dawley