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We have occasionally seen ring-shaped lateral ventricular nodules <1 cm in diameter during routine brain magnetic resonance imaging (MRI). We investigated retrospectively clinical and MRI findings of the nodules. Review of radiological records was performed for 39,607 patients who underwent brain MRI between January 2001 and April 2008. Nodules were assessed for number, location, shape, and signal intensity, which was determined based on the range of signal intensity from gray to white matter on T1- and T2-weighted imaging. Fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI), contrast enhancement characteristics, and serial MRI changes of nodules were assessed when available. Nine of 39,607 patients (0.023%) showed the nodules. No symptoms associated with the nodules. Among the nine patients, 11 nodules were identified (one nodule in seven patients (77.8%) and two nodules in two patients (22.2%)). Location was limited to the roof of the body for six nodules (54.5%) and the frontal horn for five patients (45.5%). All nodules (100%) were round and isointense on T1- and T2-weighted imaging. On FLAIR imaging of eight nodules, six (75%) were hyperintense, and two (25%) were isointense. On DWI of seven nodules, all nodules (100%) were isointense. None of seven nodules (0%) examined using postcontrast MRI showed enhancement. None of eight nodules (0%) examined using serial MRI (range, 4–60 months) showed changes in morphology over time. These nodules were incidentally encountered and shared similar MRI features. Although pathological confirmation was lacking in our cases, these nodules may be of nonaggressive nature. [ABSTRACT FROM AUTHOR]

Objective: The purpose of our study was to evaluate whether simultaneous injection into cubital veins bilaterally at one half of the standard injection rate achieves similar hepatic and aortic enhancement on MDCT as the conventional injection rate into a single cubital vein., Materials and Methods: Thirty-two patients underwent multiphase MDCT because they were suspected of having a hepatic tumor. Patients were assigned to one of the following two groups: group A, 100 mL of 370 mg I/mL of contrast medium injected into a unilateral cubital vein (one-route) via a 20-gauge cannula at a rate of 4 mL/s; or group B, 50 mL of contrast medium injected into the cubital veins bilaterally (two-route) via 24-gauge cannulas at 2 mL/s. Peak contrast enhancement of the liver and abdominal aorta for groups A and B was measured using regions of interest and compared; arrival time of the contrast media was also compared using a bolus-tracking system. Analysis was performed using Wilcoxon's signed rank test., Results: Peak aortic enhancement of groups A and B was 367 +/- 67 H and 361 +/- 113 H (p = 0.61, not significant), respectively, and peak hepatic enhancement of groups A and B was 56 +/- 11 H and 56 +/- 16 H (p = 0.88, not significant), respectively. Mean arrival time to the aorta of group B (19.4 +/- 3.4 seconds) was significantly later compared with that of group A (15.5 +/- 3.5 seconds) (p = 0.005)., Conclusion: The slower two-route injection produced the same aortic and hepatic enhancement as the faster one-route method with faster injection, but the arrival time of the contrast medium was later using the two-route method.

The development of CT and MR imaging technology represents a significant advancement. On CT imaging,the advent of multi-detector row CT (MDCT) scanners enables an increase in both scanning speed and spatial resolution. Multiphasic dynamic study is useful for the detection of hepatocellular carcinomas (HCCs) which are demonstrated as hyperattenuated lesions during the hepatic arterial phase. Many investigators assess the optimal timing for detection of HCCs by using the evolving MDCT, and have demonstrated the high detection rate for HCCs. Thanks to the increase in spatial resolution along the z-axis,we are now able to generate high-quality CT angiography and multiplanar reformations without complicated interpolation steps. These CT angiography and MPR images of patients with malignant hepatic tumors (e.g., HCCs, cholangiocellular carcinomas) are very useful for preoperative evaluation. On the other hand, the development of MR fast imaging techniques allows rapid breath-hold, whole-liver imaging. Superparamagnetic iron oxide (SPIO) is a liver-specific particulate magnetic resonance (MR) imaging contrast agent that is taken up by the reticuloendothelial system of the liver. SPIOenhanced MR imaging is useful for the detection of hepatic metastases. The advent of parallel imaging techniques improves the quality of images obtained with diffusion weighted (DW) imaging of the liver. DW imaging demonstrates high accuracy in the detection of hepatic metastases. Recently, in Japan, positron emission tomography (PET)-CT has also been employed for evaluation of hepatic metastases.

Aim: To retrospectively evaluate the prognosis of patients with hepatocellular carcinoma (HCC) with or without a history of therapy for HCC following transcatheter arterial embolization (TAE)., Methods: One hundred and twenty-one patients with HCC treated with TAE from 1992 to 2004 in our hospital were enrolled in this study. Eighty-four patients had a history of treatment for HCC, while 37 did not. At the time of entry, patients with extra-hepatic metastasis, portal vein tumor thrombosis, or Child-Pugh class C were excluded. TAE was repeated when recurrence of HCC was diagnosed by elevated tumor markers, or ultrasonography or dynamic computed tomography findings., Results: Tumor size was larger and the number of tumors was fewer in patients without past treatment (P<0.01). However, there were no differences in tumor node metastasis (TNM) stage or survival rate between the 2 groups. A bilobular tumor and high level of alpha-fetoprotein (AFP) (>100 ng/mL) were factors related to a poor prognosis in patients with a history of HCC., Conclusion: The prognosis following TAE is similar between HCC patients with and without past treatment. Early diagnosis of HCC or recurrent HCC and obtaining good local control against HCC before entry to a repeated TAE course can improve prognosis.

Objective: The purpose of this study was to assess the efficacy of contrast enhanced multi-slice helical CT (MSCT) venography for the diagnosis of deep venous thrombosis (DVT) in comparison with venous sonography., Materials and Methods: MSCT was used to obtain contiguous, 5-mm thick axial CT images from the diaphragm to the ankles of 27 patients after intravenous injection of contrast material. These patients were clinically suspected of having DVT. The same patients underwent venous sonography before CT examination. The detectability of DVT with MSCT venography was compared with that with venous sonography., Results: MSCT venography detected DVT in 21 patients, but venous sonography did so in only 17. MSCT venography detected DVT missed by venous sonography in five patients, while venous sonography detected DVT missed by MSCT venography in one patient., Conclusion: MSCT venography can be expected to make a valuable contribution to the diagnosis of DVT and to the prophylaxis of pulmonary embolism.