Purpose: We evaluated whether a perfusion study with Resovist^® is useful to assess blood flow in tumors in patients with hypervascular hepatocellular carcinoma (HCC).
Subjects and Methods: The subjects were 28 patients; the lesions consisted of 68 hypervascular HCC, 14 post-treatment nodules, and 7 hepatocellular hypovascular nodules. After rapid intravenous injection of Resovist^®, 7-phase imaging was performed using the single-shot echo-planar method. Diagnostic accuracy and tumor vascularity were evaluated by 3 radiologists using the alternative free response receiver operating characteristic method. Sensitivity, Az values, and positive predictive values were calculated. To assess interobserver variability, we evaluated the kappa static to measure the degree of agreement.
Results: The 3 observers indicated no significant difference in Az value related to the presence or absence of a perfusion study, and only one remarked a significant difference in sensitivity. However, kappa values were better in the presence than in the absence of a perfusion study. Blood flow assessment was poor in less than 1 cm. The 3 observers showed a positive predictive value of 90% or more.
Conclusion: A perfusion study may facilitate the diagnosis of hypervascular HCC, improving the diagnostic accuracy.

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To clarify the characteristics of magnetic resonance (MR) imaging of radiation-induced brain injury following carbon ion radiotherapy and to observe the changes in lesions over time, we evaluated 40 patients with radiation-induced brain injury from carbon ion radiotherapy for head and neck tumors. Their primary lesions received a radiation dose of 48 to 70.4 Gray equivalent (GyE) in 16 to 18 fractions. MR imaging of radiation-induced brain injury was graded as follows: Grade 1: change in focal white matter; focal contrast enhancement and surrounding edema; Grade 2: nonenhanced area or cystic lesion in enhanced lesion; Grade 3: focal necrosis with mass effect; and Grade 4: mass effect requiring surgical intervention. Radiation-induced brain injury appeared as early as 2 months and as late as 57 months after carbon ion therapy (mean interval, 22.2 months). MR findings of initial lesion were Grade 1 in 26 cases (65.0%), Grade 2 in 13 (32.5%), and Grade 3 in 1 (2.5%). Brain injury was always found in the radiation field initially, but cystic lesion and edema later extended outside the field in 10 cases (25.0%). In follow-up MR studies, size of edema or enhanced lesion was reduced in 17 patients (42.5%) without treatment. Two cases with large cystic lesions required surgery. Improvement of radiation-induced brain injury was observed more often than had been previously described. Because edema and cystic lesion can occasionally extend outside the radiation field, such findings do not exclude the possibility of radiation-induced brain injury. Careful observation is recommended because cystic lesions can enlarge enough to require surgical treatment in some cases.

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Purpose: The purpose of this study was to investigate the effect and usefulness of gadolinium-chelated contrast medium in phase-contrast magnetic resonance (MR) portography.
Methods: Twenty-six patients (21 men, 5 women; aged 34 to 79 years, mean 62 years) underwent respiratory-triggered 3-dimensional phase-contrast portography before and after administration of gadolinium in a 1.5T MR unit. Coronal maximum intensity projection (MIP) images of the portal vein were reconstructed and compared to conventional arterial portograms regarding visualization. Signal-to-noise ratio (SNR) and portal vein-to-liver contrast-to-noise ratios (CNR) of main, right, right anterior, right posterior, left portal veins, and umbilical portion were measured on both non-enhanced and gadolinium-enhanced images and compared.
Results: Portal veins and branches were more clearly visualized on the gadolinium-enhanced than on the non-enhanced images. Compared to arterial portography, gadolinium-enhanced portography showed similar performances in visualization, except in the right posterior branch and left portal vein. No severe image degradation from respiration was experienced. SNR was significantly higher on the gadolinium-enhanced than on non-enhanced images except in the right anterior branch. CNR was significantly higher on the gadolinium-enhanced than on the non-enhanced images at all measured locations.
Conclusions: Administration of gadolinium improves the SNR and CNR of phase-contrast portography and visualization of the portal vein. The phase-contrast technique with gadolinium enhancement can be used to evaluate the portal vein as a supplemental technique.

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Diffusion-weighted imaging (DWI) has recently been attempted in the abdominal region. We review diffusion-weighted images of the liver, especially from the technical point of view. We discuss selection of pulse sequence parameters, effects of anti-breathing motion technique, tips for measuring apparent diffusion coefficient (ADC), and utility of superparamagnetic iron oxide (SPIO), showing clinical cases, including those at 3T. Our current trial of new pulse sequencing, such as SPIO-mediated breath-holding black-blood fluid-attenuated inversion recovery (BH-BB-FLAIR), imaging is shown. Some prospects for the future in DWI of the liver are also stated.

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We investigated the feasibility of combining the active contour model with gradient vector flow (Snakes-GVF) to estimate left ventricular (LV) volumes from cardiac cine magnetic resonance imaging (MRI). MRI data were acquired from 27 patients, including 14 adults (9 men, 5 women, 55.0±23.3 years) and 13 children (10 boys, 3 girls, 2.7±2.1 years) using Gyroscan Intera (1.5 Tesla, Philips Medical Systems). LV volumes were calculated by adding the areas surrounded by the contour extracted by Snakes-GVF and compared with volumes estimated by manual tracing. Those estimated by Snakes-GVF [y (mL)] correlated well with those estimated by manual tracing [x (mL)]. In adult cases, the regression equation and correlation coefficient were y=1.008x-0.517 and 0.996, respectively. In pediatric cases, they were y=1.174x-2.542 and 0.992, respectively. In conclusion, Snakes-GVF is a powerful and useful tool for quantifying LV volumes using cardiac MRI.

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We developed a new transvaginal coil tuned for phosphorous-31 and measured its magnetic resonance spectroscopy (³¹P MRS) of uterine cervical cancer. In a 50-year-old woman with uterine cervical cancer (International Federation of Gynecology and Obstetrics [FIGO] stage IIIb), ³¹P MRS with the new coil clearly differentiated the low intensity of phosphocreatinine (PCr) and high intensity of phosphomonoester (PME) in tumor from those in muscle. Results suggests that this method will be useful for assessing uterine cervical cancer.

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