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A 74-year-old man was admitted to a local hospital with liver dysfunction. Imaging modalities revealed bile duct stenosis at the bifurcation of the anterior and posterior trunk. Exfoliative cytology of the bile and brushing cytology of the bile duct both revealed Class Ⅴ, and biopsy from the stenotic bile duct showed well differentiated adenocarcinoma. We diagnosed the patient with hilar cholangiocarcinoma and performed extended right bisectionectomy and biliary reconstruction after percuta- neous transhepatic right portal vein embolization(PTPE). Preoperatively, he was administered S-1(80mg/body weight/day) orally for 19 days. Histopathological assessment of the resected specimen revealed hemosiderin-laden macrophages without viable cancer cells, confirmingpatholog ical complete response(pCR).

Aim: The significance of radiofrequency ablation(RFA)for colorectal liver metastases(CRLM)remains to be elucidated. Therefore, this retrospective study aimed to evaluate the therapeutic efficacy of RFA for local recurrence of CRLM., Subjects: Between June 2005 and June 2017, we retrospectively examined 63 patients(137 nodules)with CRLM who underwent RFA., Results: The local recurrence rate was 36.5%, and the median local recurrence free survival(LRFS)was 26.3 months. We compared treatment background between the 2 groups with(50 nodules)and without(87 nodules)local recurrence. In the multivariate analysis, tumor size of the ablated lesion and method for ablation(direct tumor puncture)were independent risk factors for local recurrence. Receiver operating characteristic curve for tumor size of the ablated lesion showed an optimal cutoff value for tumor size of 1.8 cm(AUC=0.734, 95%CI: 0.612-0.855, p<0.0001)., Conclusions: RFA for effective control of local recurrence of CRLM might be suitable for selected patients with tumor size of ablated lesion ofC1.8 cm and no touch ablation method.

Dynamic MR imaging provides hemodynamic information about normal and pathologic tissue of the brain. The purpose of our study was to evaluate the usefulness of dynamic MR imaging in the assessment of tumor vascularity and the tumor tissue blood flow of meningiomas. We studied 13 patients with meningiomas using dynamic spin-echo MR imaging. The histological subtypes of meningioma were confirmed by the examination of surgical specimens in all patients, and tumors were meningothelial in 9 cases, fibrous in 2, transitional in 1, and psammomatous in 1. Serial images were obtained every 18-24 sec for 8 minutes and 30 seconds after rapid injection of gadolinium diethylenetriaminepentaacetic acid. Different parameters (time to peak, maximum of signal intensity and the washout ratio) were calculated directly from signal intensity curves. As an indicator of tumor vascularity, microvessel density was counted based on immunohistochemically stained sections and tumor tissue blood flow was measured using an xenon-CT system. The maximum of signal intensity corresponded to the tumor vascularity. With dynamic MR imaging, the time intensity curves (TI curves) were divided into two patterns; type 1 had a steep increase with a peak and type 2 had a slow increase to a peak followed by plateau. The maximum of signal intensity measured from TI curve of dynamic MR imaging correlated significantly with microvessel density (R2 = 0.840, p < 0.0001). Linear regression revealed a significant positive relation between the washout ratio and the tumor tissue blood flow in group showed type 1 on TI curve (R2 = 0.961, p < 0.001). There was also a significant negative correlation between the time to peak and the tumor tissue blood flow (R2 = 0.792, p < 0.01). We suggest that dynamic MR imaging is useful for evaluating hemodynamics of meningiomas.

The usefulness for evaluation of cerebral hemodynamics using time-resolved projection MRA was studied in normal volunteers and patients of cerebrovascular diseases. Six normal volunteers and ten patients with cerebrovascular occlusive diseases including 6 of IC occlusion and 4 of post EC/IC bypass surgery underwent time-resolved projection MRA on a 1.5 T clinical MRI system. Projection angiograms are acquired with 2 D-fast SPGR sequence with a time resolution of approximately one image per second, 40 images being acquired consecutively before and after bolus injection Gd-DTPA. And all images were calculated by complex subtraction from the background mask in a work station. In normal volunteers, the quality of images of time-resolved projection MRA was satisfactory. The arteries from internal carotid artery through M 2 segment of middle cerebral artery and all major venous systems were well portrayed. In 4 cases of IC occlusion who were assessed the collateral flow through the anterior communicating artery and posterior communicating artery, there were delayed to demonstrate the ipsilateral MCA. However, in 2 cases of IC occlusion that were assessed the collateral flow through leptomeningeal anastomosis, ipsilateral MCA and collateral circulation were not demonstrated. In all patients of post EC/IC bypass surgery, the patency of EC/IC bypass could be evaluated as properly with time-resolved projection MRA as 3 D-TOF MRA. Although the temporal and spatial resolutions are insufficient, time-resolved projection MRA was powerful non-invasive method to evaluate the cerebral hemodynamics via the basal communicating arteries in IC occlusion and identify the patency of EC/IC bypass.

We report an adult onset patient with moyamoya disease showing acute progress after contralateral vascular reconstructive surgery. A 47-year-old female developed cerebral infarction in the left corona radiata. A magnetic resonance (MR) angiography and a cerebral angiogram revealed severe stenosis extending from the terminal portion of left internal carotid artery (ICA) to the M1 portion. The right ICA showed slight stenosis. We performed direct bypass surgery (STA-MCA anastomosis) on the affected left side. MR angiography 1 month after surgery revealed the progressive stenosis of the C1 portion of the right ICA. While measurement of cerebral blood flow (CBF) showed a slight impairment of vascular reactivity to acetazolamide loading in the region of the right MCA, we continued without vascular reconstructive surgery for the right side because there was no ischemic attack. The patient had a transient sensory disturbance of the left upper extremity 16 months after surgery. MR angiography and a cerebral angiogram revealed more progressive stenosis extending from the right ICA to the M1 portion. CBF study showed a low CBF at rest and a negative response to acetazolamide loading in the region of the right MCA. Direct bypass surgery was performed on the right hemisphere. Follow-up study revealed an increment of rest CBF and improvement of vascular reactivity. We underlined the necessity for careful postoperation observation of progressive contralateral arterial stenosis using MR angiography and CBF study in adult onset patients with moyamoya disease.

In comparison with 99mTc-ECD SPECT, the usefulness for evaluation of cerebral blood flow by the perfusion images using MRI with FAIR sequence was studied in ischemic stroke patients. Among 27 cases, 15 patients showed lacunar infarctions and 12 patients showed cortical infarctions determined by T2 weighted MR images. FAIR images were obtained as single images at the slice position running through the basal ganglia or corona radiata. The inversion times(TI) were varied, ranging from 800 to 1,400 msec. In 15 patients without definite low perfusions in the SPECT study, FAIR images showed sequentially proxymal arterial branches in early phase and distal arterial branches or capillary beds in the cortical tissues in a late phase as the TI was elongated. Nine of the 12 patients with low cerebral perfusions in the SPECT study showed perfusion defects in FAIR imaging. Five of the 12 patients with a small low cerebral perfusion area in the SPECT study showed a delay of the depiction of cortical arteries along with TI elongation. In 3 patients, ischemic lesions demonstrated by the SPECT study was not shown in the MRI study because of motion artifacts. In conclusion, FAIR imagings are considered to be useful in the evaluation of cerebral flow dynamics in the ischemic stroke patients.

MR angiograms from 200 neurologically normal subjects aged 30 to 79 years were analyzed to assess the influence of aging and hypertension on the degree of the--visualization of the cerebral arteries. The degree of MR visualization of the cerebral arteries, including the IC, M 1, and distal MCA, was evaluated on a 4-degree scale. IC and M 1 differ in appearance. The MR gradings of each cerebral arteries showed a significant (p < 0.001) negative correlation with age. Hypertension, which is a risk factors for arteriosclerosis, significantly reduced MR grade. The degree of visualization of M 1 and the distal MCA decreased significantly with age in the normotensive group. Therefore, the decrease visualization of the cerebral arteries appears to involve not only cerebral arteriosclerosis but other factors associated with aging.

Preoperative identification of precentral gyrus and intraoperative monitoring of motor evoked potentials (MEPs) were performed to preserve postoperative motor function in seven patients with gliomas near the primary motor cortex. Tumors were astrocytomas in 3 patients, glioblastomas in 2 patients, anaplastic astrocytoma and mixed glioma in one patient each. Preoperative identification of the primary motor cortex was performed by three-dimensional (3D) display of magnetic resonance (MR) images and by functional images using MR imaging and single-photon emission tomography. The primary motor cortex identified by 3D display of MR images coincided well with that identified by functional images. 3D display of MR images was also useful for detecting the relationship between the tumor and the primary motor cortex. Intraoperatively, the central sulcus was confirmed by the finding of phase reversal of cortical somatosensory evoked potential, and this corresponded with the preoperative identifications by 3D display and by functional mapping. The primary motor cortex was stimulated electrically, and MEP (corticospinal evoked potential) was continuously monitored during surgery using electrodes inserted in the cervical epidural space. The amplitude of direct waves of MEPs during surgery was maintained above half of that recorded at the beginning of tumor removal, and all patients showed preservation of preoperative motor function. These results suggest that preoperative identification of precentral gyrus and intraoperative MEP monitoring provide useful information for preserving motor function in patients with gliomas near the primary motor cortex.

MR imaging of brain function has been successfully performed at 1.5 T clinical MR unit. In the early studies, functional MRI were performed with simple stimulation such as visual and motor. Recently, many investigators have attempted to demonstrate the specific brain localization of higher brain functions such as memory, imagination, language and so on. In this study, we attempted the functional MRI for motor and word imagination with gradient echo sequences on clinical MR unit. In our experiences, motor cortex was activated on motor imagination task and Broca area was activated on word imagination task, respectively. We demonstrated the higher brain functions were able to be demonstrated on clinical MR unit with gradient echo sequences.

This study was undertaken in order to clarify the influence of acute hepatic blood flow occlusion on arterial blood ketone body ratio (AKBR) and systemic hemodynamics. Ten patients for hepatectomy were divided into two groups. Group I was composed of five patients who had clamping of total hepatic blood flow (Pringle's method), and Group II was composed also of five patients who had clamping of the right hepatic artery and portal vein during operation. Ten minutes after clamping blood flow, AKBR decreased significantly in both groups, and a marked reduction in AKBR was observed in group I. During occlusion, cardiac output was reduced significantly, and immediately after declamping, mean arterial blood pressure and systemic vascular resistance index (SVRI) decreased significantly. These changes in hemodynamics in group I were larger than those of the other group. A larger reduction in AKBR was observed during occlusion, and the greater change in SVRI appeared after declamping blood flow. These findings suggest that in the cases with hepatic blood flow occlusion, especially total occlusion, a special attention should be paid to mitochondrial liver dysfunction and hemodynamic changes associated with acute hepatic blood occlusion.

In an attempt to determine how the degree of the experimental calculus removal on the metallic plate and its roughness after scaling would be affected by ultrasonics under high or low frequency, quantitative measurement and morphological observation were made. The results obtained were as follows: 1. On the calculus removal, larger effect was obtained by high frequency unit than low frequency. 2. On the roughness of the metallic plate after scaling, larger defect was observed by high frequency unit than low frequency. 3. Scanning electron microscopically, strip like defects were observed under low frequency unit, while exfoliation of the metallic plate in addition to the strip like defects were observed under high frequency.

The purpose of this study was to examine the relationship between clinical findings and subgingival relationship between clinical findings and subgingival microbial flora in periodontitis at the first medical examination and after initial preparation. The results obtained were as follows: 1. Clinical findings with the exception of plaque index showed improvement after initial preparation in comparison with the first medical examination. 2. In phase contrast microscopy, both total bacteria and incidence of spirochetes and motile rods decreased after initial preparation in comparison with the first medical examination. 3. Clinical findings with the exception of plaque index were related to the total bacteria and proportional distribution of spirochetes and motile rods in periodontal pockets, observed in phase contrast microscopy. 4. Total bacteria and proportional distribution of black-pigmented Bacteroides in periodontal pockets decreased after initial preparation in comparison with the first medical examination.

Colored spatial mapping electrocardiography (ECG) was developed for practical use from Frank lead vectorcardiography using a microcomputer system (CERX-CQ3001). Compared to body surface electrocardiography this new device facilitated easy recording and analysis for display on eight-colored spatial mapping electrocardiography at points equivalent to those on a terrestrial globe at intervals of 20 degrees longitude and 10 degrees latitude. In this study, the extent and direction of the Q waves were easily recognized with the aid of a colored display and mapping electrocardiography. To quantitatively evaluate infarct size, the total Q wave area (sigma Aq) was calculated from the mapping electrocardiograms of 12 patients with anteroseptal myocardial infarction, and compared with thallium defect scores obtained by single photon emission CT (SPECT) and the left ventricular ejection fraction (EF). Defect scores were calculated using short-axis images. Sigma Aq was correlated with defect scores and EF (r = 0.83, 0.45, respectively). This new type of colored spatial mapping electrocardiography proved useful for detecting myocardial infarction and for evaluating infarct size.