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Phlebosclerotic colitis (PC) is a rare form of ischemic colitis that usually affects the right hemicolon. It is due to ischemia induced by phlebosclerosis in the branches of the superior mesenteric vein that disturb venous return from the colon. The clinical course is different from that of the more common type of ischemic colitis caused by arterial disease. We encountered a 73-year-old woman with PC who had the characteristic computed tomographic finding of fine linear venous calcification that was mainly perpendicular to the long axis of the colon.

Omental torsion is a rare cause of acute abdomen. The diagnosis is usually not established before surgery, but recently some reports have described the usefulness of computed tomography (CT) for the detection of this condition. We encountered a 58-year-old man with torsion of the greater omentum secondary to right-sided inguinal hernia, and present the characteristic CT findings of a whirl-like mass with hyperattenuated fatty tissue.

Small bowel obstruction due to lesser sac herniation through both the gastrocolic and gastrohepatic omenta is extremely rare, and only a few reported cases have been concerned with imaging diagnosis. CT images showed distended bowel loops at the level of the cephalad part of the stomach, collapsed triangular loops and attached mesentery were depicted just behind the caudal part of the stomach. These findings provided clues to the diagnosis of this type of lesser sac hernia.

We report a case of the papillonodular type of cystic partially differentiated nephroblastoma (CPDN), an extremely rare renal neoplasm that occurs in newborns and infants. The papillonodular type of CPDN is a variant of the conventional form of CPDN. MRI clearly demonstrated the gross pathologic features, distinguishing it from other renal multilocular cystic tumors.

The MR imaging of an ovarian carcinosarcoma is described. The tumor was heterogeneous and showed very high-intensity on T2-weighted images and iso-intensity on T1-weighted images, with visible enhancement. Even though signal intensities were somewhat different from those of ovarian adenocarcinoma, the preoperative diagnosis of ovarian carcinosarcoma is still difficult.

Purpose: We analyzed the efficacy of initial local response of MBT by imaging obtained within two months after treatment, to determine if there are factors that may be important for the initial local response of the disease. If an earlier local tumor response can be expected from SRS, patients with a poor prognosis should be treated with this modality., Methods: Thirty-six patients with 59 lesions were treated by linac radiosurgery. The primary tumor, peripheral dose, tumor volume, and CT enhancement pattern of the tumor before treatment (homogeneous or ring-enhancing) were chosen as factors related to local tumor response and were used in the statistical analysis., Results: 1) The initial local response of radiation-resistant tumors to conventional EBRT was worse than that of other tumors. The initial local responses of MBT from breast carcinoma, colon carcinoma, and pulmonary carcinoma were good. 2) Excluding radioresistant tumors, the cases irradiated at 25 Gy or more tended to show good local control. 3) No statistically significant differences were found between local response and factors such as the enhancement pattern and tumor volume in the analysis of MBT.

Purpose: To determine whether left- or right-side uniaural stimulation produces different fMRI activation patterns., Methods: Subjects were 12 volunteers (8 right-handed, 4 left-handed) with normal hearing. Functional imaging using FE-type multishot echo planar imaging was obtained in the axial plane during pure-tone and pseudoword tasks. Auditory stimuli were presented to each ear individually. In pure-tone tasks, subjects heard clustered sequences at 2000 Hz. In pseudoword tasks, subjects heard spoken Japanese syllables. The numbers of activated pixels in the auditory cortex were counted and compared for pure-tone and pseudoword tasks, as was activation according to the side of aural stimulation., Results: In right-handed subjects, prominent activation in pure-tone tasks was noted in the dominant hemisphere in 100% of cases and was unrelated to the side of the stimulation. In pseudoword tasks, prominent activation was noted on the side contralateral to the stimulus in 62.5-100% of cases. In left-handed subjects, prominent activation was noted on the side contralateral to the stimulus in both pure-tone and pseudoword tasks., Conclusion: Left- and right-side stimulation produced differences in fMRI responses, especially between pure-tone and pseudoword tasks. Moreover, right-handedness and left-handedness affected results. This type of auditory fMRI may be a noninvasive indicator of language lateralization.

We studied 76 patients with cerebral arteriovenous malformations (AVMs) using dynamic-CT with intravenous injection of contrast material and reconstructed three-dimensional images (3D-CT angiography). All patients received stereotactic radiotherapy (gamma-knife). We compared 3D-CT angiography with conventional angiography to determine the usefulness of this technique. 3D-CT angiography could be performed in conjunction with usual axial high-resolution CT without any additional scanning time and within 10-30 minutes for the overall study. Most niduses and drainers of AVMs were clearly visualized by 3D-CT angiography. 3D-reconstruction was very helpful in demonstrating the niduses, drainers, and three-dimensional structure of AVMs. Demonstrations of feeders were not remarkable. Dynamic CT was very helpful in dose planning for gamma-knife radiosurgery, because gamma-knife angiograms were limited in terms of angles, magnification, and establishing precise localizations using a head frame. 3D-CT added information on trails of drainers and was useful in reducing the volume of irradiation. 3D-CT angiography of cerebral AVMs could be performed routinely, and three-dimensional imaging was helpful in demonstrating the complex anatomy of cerebral AVMs. This technique was very helpful in planning gamma-knife radiosurgery.

We report a case of linear nevus sebaceous syndrome with seizure, mental retardation, and hemiparesis. Magnetic resonance imaging (MRI) clearly demonstrated associated brain malformations of unilateral megalencephaly with cortical dysplasia and white matter change ipsilateral to the sebaceous nevi of the face and neck. Although magnetic resonance angiography (MRA) demonstrated only distortion of the main cerebral arteries without any occlusive or dysplastic findings, single photon emission computed tomography (SPECT) using [123I]N-Isopropyl-p-iodoamphetamine (IMP) revealed hypoperfusion in the affected cerebral hemisphere.

Since the introduction of linac radiosurgery in October 1994, we have treated 27 patients with 36 lesions. We treated nine AVM, 12 metastatic brain tumors, two malignant lymphomas, one anaplastic astrocytoma, two meningiomas, and one brain tumor of unknown pathology. In the follow-up examinations at least five months after treatment, the local control rate was 83% for the metastatic tumors, and two malignant lymphomas disappeared completely. In addition, satisfactory results have been obtained with AVM and other brain tumors without any side effects. In comparison with gamma-knife radiosurgery, linac radiosurgery has some disadvantages such as longer treatment time and cumbersome accuracy control, but if accuracy control is performed periodically, accuracies of 1 mm or less can be obtained. There is some strengths of linac radiosurgery as follow. 1) The acquisition cost is relatively low. 2) Dose distribution are equivalent to gamma-knife. 3) There is no field size limitation. 4) There is great flexibility in beam delivery and linac systems. Radiosurgery using linear accelerators seems to become widely accepted in the future.

This paper reports a patient with advanced esophageal cancer who has survived asymptomatically for five years after radiotherapy given under informed consent. Previously, we had not practiced radiotherapy under informed consent for patients with esophageal cancers. His excellent clinical course encouraged us to promote this form of treatment. This report presents his excellent clinical course in detail and discusses the significance of informed consent in radiotherapy for malignancies.

A 31-year-old female having a family history of neurofibromatosis 1 presented a left CPA tumor. MRI findings showed a completely extraaxial tumor, suggesting an acoustic neurinoma except for the lesion in the acoustic meatus. However, the final diagnosis was of exophytic pontine glioma. When a CPA tumor shows no lesion in the internal acoustic meatus, the possibility of exophytic pontine glioma should be considered in the differential diagnosis, especially in NF-1 patients.

The authors present a case of hypertensive encephalopathy in which CT and MR were performed. The brain stem and cerebellum were revealed as low density areas on CT and high intensity areas on T2-weighted MR images with mass effect. Slight abnormality was also noticed in the deep cerebral white matter. This distribution pattern is contrary to that described in previous reports in which cerebral white matter was mainly involved. The lesions showed definite improvement when the blood pressure was normalized. MR is more sensitive than CT, and is useful for early detection of the abnormality and follow-up study.