OBJECTIVE: To evaluate the multiphase contrast-enhanced magnetic resonance (MR) imaging features of Bacillus Calmette-Guerin (BCG)-induced granulomatous prostatitis (GP). MATERIALS AND METHODS: Magnetic resonance images obtained from five patients with histopathologically proven BCG-induced GP were retrospectively analyzed for tumor location, size, signal intensity on T2-weighted images (T2WI) and diffusion-weighted images (DWI), apparent diffusion coefficient (ADC) value, and appearance on gadolinium-enhanced multiphase images. MR imaging findings were compared with histopathological findings. RESULTS: Bacillus Calmette-Guerin-induced GP (size range, 9-40 mm; mean, 21.2 mm) were identified in the peripheral zone in all patients. The T2WI showed lower signal intensity compared with the normal peripheral zone. The DWIs demonstrated high signal intensity and low ADC values (range, 0.44-0.68 x 10(-3) mm2/sec; mean, 0.56 x 10(-3) mm2/sec), which corresponded to GP. Gadolinium-enhanced multiphase MR imaging performed in five patients showed early and prolonged ring enhancement in all cases of GP. Granulomatous tissues with central caseation necrosis were identified histologically, which corresponded to ring enhancement and a central low intensity area on gadolinium-enhanced MR imaging. The findings on T2WI, DWI, and gadolinium-enhanced images became gradually obscured with time. CONCLUSION: Bacillus Calmette-Guerin-induced GP demonstrates early and prolonged ring enhancement on gadolinium-enhanced MR imaging which might be a key finding to differentiate it from prostate cancer.
Aged ; Gadolinium/*diagnostic use ; Humans ; Image Enhancement ; Immunotherapy/*adverse effects ; Magnetic Resonance Imaging/*methods ; Magnetic Resonance Spectroscopy ; Male ; Middle Aged ; Mycobacterium bovis/*pathogenicity ; Prostate-Specific Antigen/blood ; Prostatic Neoplasms/diagnosis ; Prostatitis/*diagnosis ; Retrospective Studies ; Urinary Bladder Neoplasms/drug therapy

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

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: Single dose gadolinium (Gd) enhanced fluid-attenuated inversion recovery (FLAIR) is helpful for visualizing superficial parenchymal metastases. However, the usefulness of FLAIR with a higher dose of Gd is uncertain. The aim of our study was two-folds: first, to prove that the signal to noise ratio (SNR) of small brain metastases is higher than large brain metastases on double-dose (DD) enhanced FLAIR and, second, to explore the added value of DD Gd enhanced FLAIR in relation to T1 GRE for evaluating small brain metastases. MATERIALS AND METHODS: For the first purpose, 50 pairs of small (2 mm5 mm) were included. The difference in the SNR and contrast ratio (CR) between small and large metastases on DD Gd-enhanced 3D T2 FLAIR was compared by Wilcoxon signed-rank tests. For the second purpose, a total of 404 small metastases were included. The diagnostic sensitivities between 3D T1 gradient echo (GRE) alone and combined results of 3D T1 GRE and 3D T2 FLAIR were compared with McNemar test. RESULTS: The SNR and CR of small brain metastases were significantly higher than those of large brain metastases (p<0.001). In qualitative analysis, the diagnostic sensitivities for small brain metastases were significantly higher for 3D T1 GRE plus 3D T2 FLAIR than 3D T1 GRE alone regardless of scan time (p<0.001). CONCLUSION: Small brain metastases showed higher signal intensity than large brain metastases on the DD Gd enhanced 3D T2 FLAIR images. DD Gd enhanced 3D T2 FLAIR imaging may have a complementary role to 3D T1 GRE for evaluating small brain metastases.
Adult ; Aged ; Brain Neoplasms/*pathology ; Contrast Media/administration & dosage/*diagnostic use ; Female ; Gadolinium/administration & dosage/*diagnostic use ; Humans ; Imaging, Three-Dimensional ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Retrospective Studies ; Signal-To-Noise Ratio

OBJECTIVE: To report the feasibility of magnetic resonance imaging (MRI)-guided intervention for diagnosing suspicious breast lesions detectable by MRI only, using the freehand technique with a 3.0-T closed-bore MRI scanner. MATERIALS AND METHODS: Five women with 5 consecutive MRI-only breast lesions underwent MRI-guided intervention: 3 underwent MRI-guided needle localization and 2, MRI-guided vacuum-assisted biopsy. The interventions were performed in a 3.0-T closed-bore MRI system using a dedicated phased-array breast coil with the patients in the prone position; the freehand technique was used. Technical success and histopathologic outcome were analyzed. RESULTS: MRI showed that four lesions were masses (mean size, 11.5 mm; range, 7-18 mm); and 1, a nonmass-like enhancement (maximum diameter, 21 mm). The locations of the lesions with respect to the breast with index cancer were as follows: different quadrant, same breast - 3 cases; same quadrant, same breast - 1 case; and contralateral breast - 1 case. Histopathologic evaluation of the lesions treated with needle localization disclosed perilobular hemangioma, fibrocystic change, and fibroadenomatous change. The lesions treated with vacuum-assisted biopsy demonstrated a radial scar and atypical apocrine hyperplasia. Follow-up MRI after 2-7 months (mean, 4.6 months) confirmed complete lesion removal in all cases. CONCLUSION: MRI-guided intervention for breast lesions using the freehand technique with a 3.0-T closed-bore MRI scanner is feasible and accurate for diagnosing MRI-only lesions.
Adult ; Biopsy, Needle ; Breast Neoplasms/*pathology ; Contrast Media/diagnostic use ; Diagnosis, Differential ; Feasibility Studies ; Female ; Gadolinium DTPA/diagnostic use ; Humans ; Magnetic Resonance Imaging/*instrumentation ; Magnetic Resonance Imaging, Interventional/*methods ; Middle Aged ; Neoplasm Staging ; Retrospective Studies ; Vacuum

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

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

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