T. Sugawara

We evaluated the accuracy of one commercially available and three publicly available deformable image registration (DIR) algorithms for thoracic four-dimensional (4D) computed tomography (CT) images. Five patients with esophagus cancer were studied. Datasets of the five patients were provided by DIR-lab (dir-lab.com) and consisted of thoracic 4D CT images and a coordinate list of anatomical landmarks that had been manually identified. Expert landmark correspondence was used for evaluating DIR spatial accuracy. First, the manually measured displacement vector field (mDVF) was obtained from the coordinate list of anatomical landmarks. Then the automatically calculated displacement vector field (aDVF) was calculated by using the following four DIR algorithms: B-spine implemented in Velocity AI (Velocity Medical, Atlanta, GA, USA), free-form deformation (FFD), Horn-Schunk optical flow (OF) and Demons in DIRART of MATLAB software. Registration error is defined as the difference between mDVF and aDVF. The mean 3D registration errors were 2.7 ± 0.8 mm for B-spline, 3.6 ± 1.0 mm for FFD, 2.4 ± 0.9 mm for OF and 2.4 ± 1.2 mm for Demons. The results showed that reasonable accuracy was achieved in B-spline, OF and Demons, and that these algorithms have the potential to be used for 4D dose calculation, automatic image segmentation and 4D CT ventilation imaging in patients with thoracic cancer. However, for all algorithms, the accuracy might be improved by using the optimized parameter setting. Furthermore, for B-spline in Velocity AI, the 3D registration error was small with displacements of less than ∼10 mm, indicating that this software may be useful in this range of displacements.

Hypertensive tendencies in the rural inhabitants of north-east Japan are discussed. in relation to data collected on the Pacific side of that area. Effects of environmental conditions on blood pressure level are considered under 3 headings; physical environment, diet and socioeconomic circumstances. It is reasonably certain that pressure is inversely related to temperature, but the effect of noise at place of work appears to be unimportant although it can cause a physiological rise. With regard to diet, the consumption of a large amount of polished rice with few vegetables but much salt seems to be a factor increasing the prevalence of hypertension and cerebral haemorrhage in these districts. The effects of socioeconomic circumstancesis less clear, perhaps because the extent of socioeconomic variation is limited in these rural districts. Further investigation of the factors influencing the hypertensive tendency in these areas is needed.

A 37-year-old man was admitted to our clinic 3 hours after the onset of cerebrovascular accident with right hemiparesis and total aphasia. On admission, we started combined administration of mannitol, vitamin E, phenytoin (Sendai Cocktail) and perfluorochemicals to protect ischemic brain. Left cerebral angiography revealed occlusion of the left middle cerebral artery involving its perforating arteries. Following the performance of angiography, vascular balloon catheter was introduced into the embolus, and fibrinolytic agent (urokinase) was continuously injected. Soon after the injection of 240,000 unit urokinase, recanalization of left middle cerebral artery was shown by repeated cerebral angiography performed 5.5 hours after the onset. On his clinical course, left hemiparesis and aphasia were improved step by step, and 1 week later, he could walk by himself with minor neurological deficits. Further examination revealed that myxoma was located on left atrium by echocardiography. Within 1 week, the patient was transferred to cardio-surgical unit, and myxoma was successfully removed. Now he is in good health and has returned to his job. Usually cerebral embolisms result from atrial myxoma cause severe cerebral infarction. Here we reported a case of cerebral embolism by myxoma and recanalized using fibrinolytic agent by balloon catheter injection. The damage will be reduced if the duration of occlusion is limited, so this method will be helpful to treat cerebral embolism.