OBJECTIVE: This study was designed to determine the optimal mixture ratio of gadolinium and iodinated contrast agent for simultaneous direct MR arthrography and CT arthrography. MATERIALS AND METHODS: An in vitro study was performed utilizing mixtures of gadolinium at six different concentrations (0.625, 1.25, 2.5, 5.0, 10 and 20 mmol/L) and iodinated contrast agent at seven different concentrations (0, 12.5, 25, 37.5, 50, 75 and 92-99.9%). These mixtures were placed in tissue culture plates, and were then imaged with CT and MR (with T1-weighted sequences, proton-density sequences and T2-weighted sequences). CT numbers and signal intensities were measured. Pearson's correlation coefficients were used to assess the correlations between the gadolinium/iodinated contrast agent mixtures and the CT numbers/MR signal intensities. Scatter diagrams were plotted for all gadolinium/iodinated contrast agent combinations and two radiologists in consensus identified the mixtures that yielded the optimal CT numbers and MR signal intensities. RESULTS: The CT numbers showed significant correlation with iodinated contrast concentrations (r = 0.976, p < 0.001), whereas the signal intensities as measured on MR images showed a significant correlation with both gadolinium and iodinated contrast agent concentrations (r = -484 to -0.719, p < 0.001). A review of the CT and MR images, graphs, and scatter diagram of 42 combinations of the contrast agent showed that a concentration of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was the best combination for simultaneous CT and MR imaging. CONCLUSION: A mixture of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was found to be optimal for simultaneous direct MR arthrography and CT arthrography.
*Arthrography ; Contrast Media/*administration & dosage ; Gadolinium/administration & dosage/*diagnostic use ; Iohexol/administration & dosage/*analogs & derivatives/diagnostic use ; *Magnetic Resonance Imaging ; Meglumine/administration & dosage/*diagnostic use ; Organometallic Compounds/administration & dosage/*diagnostic use ; Phantoms, Imaging ; *Tomography, X-Ray Computed

OBJECTIVE: To evaluate the effectiveness of uterine artery embolization (UAE) for treating symptomatic fibroids with high signal intensity (SI) on magnetic resonance (MR) T2-weighted imaging (T2WI). MATERIALS AND METHODS: A total of 537 cases, consisting of 14 patients with high SI fibroids on T2WI (T2 high group), were retrospectively included and compared with 28 randomly selected patients with low SI fibroids on T2WI (control group). High SI of a predominant fibroid on T2WI was defined as having the same or higher SI than the myometrium. Patient ages ranged from 28 to 52 years (mean, 38.1 years). All patients underwent MRI before and after UAE. Predominant fibroid and uterine volumes were calculated with MR images. Symptom status in terms of menorrhagia and dysmenorrhea was scored on a scale of 0-10, with 0 being no symptoms and 10 being the baseline, or initial symptoms. RESULTS: Of the patients in the T2 high group, 13 out of 14 (92.9%) patients demonstrated complete necrosis of the predominant fibroids. The mean volume reduction rates of the predominant fibroids in the T2 high group was 61.7% at three months after UAE, which was significantly higher than the volume reduction rates of 42.1% noted in the control group (p < 0.05). Changes in symptom scores for menorrhagia and dysmenorrhea after UAE (baseline score minus follow-up score) were 4.9 and 7.5 in T2 high group and they were 5.0 and 7.7 in control group, suggesting a significant resolution of symptoms (p < 0.01) in both groups but no significant difference between the two groups. CONCLUSION: UAE is effective for uttering fibroids showing high SI on T2WI. The mean volume reduction rate of the predominant fibroids three months after UAE was greater in the T2 high group than in the control group.
Adult ; Case-Control Studies ; Contrast Media/diagnostic use ; Female ; Humans ; Leiomyoma/*therapy ; Magnetic Resonance Imaging, Interventional/*methods ; Meglumine/diagnostic use ; Middle Aged ; Organometallic Compounds/diagnostic use ; Questionnaires ; Retrospective Studies ; Treatment Outcome ; Uterine Artery Embolization/*methods ; Uterine Neoplasms/*therapy

Hepatocyte specific contrast agents including gadoxetic acid and gadobenate dimeglumine are very useful to diagnose various benign and malignant focal hepatic lesions and even helpful to estimate hepatic functional reservoir. The far delayed phase image referred to as the hepatobiliary phase makes the sensitivity of detection for malignant focal hepatic lesions increased, but specificity of malignant diseases, including hepatocellular carcinoma, metastasis and cholangiocarcinoma, characterization remained to be undetermined.
Carcinoma, Hepatocellular/radiography ; Cholangiocarcinoma/radiography ; Contrast Media/chemistry/*diagnostic use ; Hemangioma/radiography ; Humans ; Liver Diseases/*radiography ; Liver Neoplasms/radiography ; Magnetic Resonance Imaging ; Meglumine/*analogs & derivatives/chemistry/diagnostic use ; Organometallic Compounds/chemistry/*diagnostic use

Gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging simultaneously provides both morphological and functional information by the acquisition of dynamic and hepatobiliary-phase imaging. Focal lesions with no functioning hepatocytes, where hepatobiliary metabolism is blocked or inhibited, are generally unable to uptake and excrete gadobenate dimeglumine into the bile. Such lesions are typically malignant and usually appear hypointense as compared to the normal liver parenchyma as seen on hepatobiliary-phase imaging. However, various benign hepatic lesions may also be hypointense due to (a) the presence of no functioning hepatocytes, (b) damage to the functioning hepatocytes or (c) impairment of biliary function as depicted on hepatobiliary-phase imaging. All of these imaging features may result in recognition of the benign hepatic lesions as hepatic malignancies. As depicted on three-hour delayed hepatobiliary-phase imaging, peripheral iso/hyperintensity due to fibrotic tissue compared to the hypointense center with a fuzzy margin may be a clue for the presence of a benign hepatic lesion. In contrast, peripheral hypointensity due to rich tumoral cellularity compared to the center with a clear margin may favor an indication of the presence of a malignant hepatic lesion.
Adult ; Aged ; Contrast Media/*diagnostic use ; Diagnosis, Differential ; Female ; Humans ; Image Enhancement/methods ; Liver/pathology ; Liver Diseases/diagnosis/pathology ; Liver Neoplasms/*diagnosis/*pathology ; Magnetic Resonance Imaging/*methods ; Male ; Meglumine/*analogs & derivatives/diagnostic use ; Middle Aged ; Organometallic Compounds/*diagnostic use ; Time

OBJECTIVE: To investigate the efficacy of gadobenate dimeglumine (Gd-BOPTA) enhanced MR imaging for the detection of liver lesions in patients with primary malignant hepatic neoplasms. MATERIALS AND METHODS: Thirty-one patients with histologically proven primary malignancy of the liver were evaluated before and after administration of Gd-BOPTA at dose 0.05 or 0.10 mmol/kg. T1-weighted spin echo (T1W-SE) and gradient echo (T1W-GRE) images were evaluated for lesion number, location, size and confidence by three off-site independent reviewers and the findings were compared to reference standard imaging (intraoperative ultrasound, computed tomography during arterial portography or lipiodol computed tomography). Results were analyzed for significance using a two-sided McNemar's test. RESULTS: More lesions were identified on Gd-BOPTA enhanced images than on unenhanced images and there was no significant difference in lesion detection between either concentration. The largest benefit was in detection of lesions under 1 cm in size (7 to 21, 9 to 15, 16 to 18 for reviewers A, B, C respectively). In 68% of the patients with more than one lesion, Gd-BOPTA increased the number of lesions detected. CONCLUSION: Liver MR imaging after Gd-BOPTA increases the detection of liver lesions in patients with primary malignant hepatic neoplasm.
Adenoma, Liver Cell/*diagnosis ; Adult ; Aged ; *Contrast Media ; Female ; Human ; Image Enhancement ; Liver Neoplasms/*diagnosis ; Magnetic Resonance Imaging/*methods ; Male ; Meglumine/*analogs & derivatives/*diagnostic use ; Middle Age ; Organometallic Compounds/*diagnostic use

OBJECTIVE: We wanted to report on our experience with modified radiology-guided percutaneous gastrostomy (MRPG) without endoscopic or nasogastric access for treating patients with complete obstruction of the upper digestive tract. MATERIALS AND METHODS: Fourteen oncology patients (13 had hypopharyngeal cancer and 1 had upper esophageal cancer) with complete obstruction of the upper digestive tract were recruited. Conventional percutaneous endoscopic gastrostomy (PEG) and radiologic (fluoroscopy-guided) percutaneous gastrostomy (RPG) were not feasible in all the patients. An MRPG technique (with a combination of ultrasound, an air enema and fluoroscopic guidance) was performed in these patients. RESULTS: We achieved successfully percutaneous gastrostomy using the modified technique in all patients without any major or minor complications after the procedure. CONCLUSION: A modified radiology-guided percutaneous gastrostomy technique can be safely performed in patients who failed to receive conventional PEG or RPG due to the absence of nasogastric access in the completely obstructed upper digestive tract.
Adult ; Aged ; Conscious Sedation ; Contrast Media/diagnostic use ; Esophageal Neoplasms/radiography/*surgery ; Female ; Gastrostomy/*methods ; Humans ; Intestinal Obstruction/radiography/*surgery ; Iothalamate Meglumine/diagnostic use ; Laryngeal Neoplasms/radiography/*surgery ; Male ; Middle Aged ; Radiography, Interventional ; Retrospective Studies ; Upper Gastrointestinal Tract/radiography/*surgery

OBJECTIVE: To compare the efficacy of Mangafodipir trisodium (Mn-DPDP) -enhanced MR cholangiogrphy (MRC) and Gadobenate dimeglumine (Gd-BOPTA) -enhanced MRC in visualizing a non-dilated biliary system. MATERIALS AND METHODS: Eighty-eight healthy liver donor candidates underwent contrast-enhanced T1-weighted MRC. Mn-DPDP and Gd-BOPTA was used in 36 and 52 patients, respectively. Two radiologists reviewed the MR images and rated the visualization of the common duct, the right and left hepatic ducts, and the second-order branches using a 4-point scale. The contrast-to-noise ratio (CNR) of the common duct to the liver in the two groups was also compared. RESULTS: Mn-DPDP MRC and Gd-BOPTA MRC both showed similar visualization grades in the common duct (p = .380, Mann-Whitney U test). In the case of the proximal bile ducts, the median visualization grade was significantly higher with Gd-BOPTA MRC than with Mn-DPDP MRC (right hepatic duct: p = 0.016, left hepatic duct: p = 0.014, right secondary order branches: p = 0.006, left secondary order branches, p = 0.003). The common duct-to-liver CNR of the Gd-BOPTA MRC group was significantly higher (38.90+/-24.50) than that of the Mn-DPDP MRC group (24.14+/-17.98) (p = .003, Student's t test). CONCLUSION: Gd-BOPTA, as a biliary contrast agent, is a potential substitute for Mn-DPDP.
Pyridoxal Phosphate/*analogs & derivatives/diagnostic use ; Organometallic Compounds/*diagnostic use ; Middle Aged ; Meglumine/*analogs & derivatives/diagnostic use ; Male ; *Magnetic Resonance Imaging ; Humans ; Hepatic Duct, Common/anatomy & histology ; Female ; Feasibility Studies ; Edetic Acid/*analogs & derivatives/diagnostic use ; *Contrast Media ; Common Bile Duct/anatomy & histology ; Bile Ducts/*anatomy & histology ; Aged ; Adult

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.
Adult ; Aged ; Carcinoma, Hepatocellular/*diagnosis ; Female ; Gadolinium DTPA/*diagnostic use ; Humans ; Image Interpretation, Computer-Assisted ; Liver Neoplasms/*diagnosis ; Magnetic Resonance Imaging/*methods ; Male ; Meglumine/*analogs & derivatives/diagnostic use ; Middle Aged ; Organometallic Compounds/*diagnostic use ; Predictive Value of Tests ; ROC Curve ; Sensitivity and Specificity ; Statistics, Nonparametric