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Shuichi Higano

Publications and source records attributed to Shuichi Higano.

At least 19 recordsLinked to original sources
PubMed2006

Surgical treatment of paraventricular cavernous angioma: fibre tracking for visualizing the corticospinal tract and determining surgical approach.

Surgical treatment of deep-seated lesions involving the corticospinal tract is one of the most challenging areas of contemporary neurosurgery, even given the recent development of radiological methods including three-dimensional anisotropy contrast magnetic resonance imaging (MRI) axonography. Fibre tracking using diffusion tensor imaging is another MRI technique that can be used to visualize anisotropy and the orientation of white matter tracts in the brain. We report herein a patient with a paraventricular cavernous angioma manifesting as hemiparesis caused by haemorrhage. Preoperative conventional MRI failed to determine the anatomical relationship between the paraventricular lesion and the corticospinal tract, whereas fibre tracking using free software (dTV for MR-DTI analysis) indicated that the corticospinal tract was displaced anterolaterally from the medial side. The paraventricular lesion was completely removed without damaging the corticospinal tract using a transcortical transventricular approach. Preoperative fibre tracking is useful in surgical planning for procedures involving deep-seated lesions adjacent to the corticospinal tract, and may avoid postoperative morbidity due to corticospinal tract injury.

Adult↗
PubMed2006

Malignant astrocytic tumors: clinical importance of apparent diffusion coefficient in prediction of grade and prognosis.

PURPOSE: To retrospectively assess the apparent diffusion coefficient (ADC) for prediction of malignancy and prognosis of malignant astrocytic tumors. MATERIALS AND METHODS: The institutional review board approved this study and did not require patient informed consent. Findings from 37 consecutive patients (21 men, 16 women; mean age, 43 years) with pathologically proved malignant astrocytic tumors that included 22 glioblastomas (GBMs) and 15 anaplastic astrocytomas (AAs) were retrospectively evaluated. The minimum ADC value of each tumor was preoperatively determined from several regions of interest defined in the tumor, preferably with avoidance of cystic or necrotic components, on ADC maps derived from isotropic diffusion-weighted images. Surgical intervention, followed by radiation therapy, was undertaken in all cases according to hospital protocol. Immunohistologically, Ki-67 labeling index (LI), indicating cell proliferation, was also determined. The patients were classified into two groups, progressive and stable, according to the 2-year observation after the initial treatment. Correlation analysis (Pearson product moment correlation), Student t test, Welch test, receiver operating characteristic analysis, and Kaplan-Meier method with log-rank test were used for statistical evaluation. RESULTS: There was a significant negative correlation between minimum ADC and Ki-67 LI (r = -0.562, P < .001). The mean minimum ADC (0.834 x 10(-3) mm2 x sec(-1)) of GBM was significantly lower than that (1.06 x 10(-3) mm2 x sec(-1)) of AA (P < .001, Student t test). The mean minimum ADC (0.80 x 10(-3) mm2 x sec(-1)) of the progressive group was significantly lower than that (1.037 x 10(-3) mm2 x sec(-1)) of the stable group (P < .001). The cutoff value of 0.90 x 10(-3) mm2 x sec(-1) for minimum ADC for differentiation of patients with a favorable prognosis from those with a poor prognosis provided the best combination of sensitivity (79%) and specificity (81%) (receiver operating characteristic analysis). The significant difference in the prognosis between two groups classified by using this cutoff value of minimum ADC was noted (P = .002, log-rank test). CONCLUSION: The minimum ADC of malignant astrocytomas can provide additional information about their clinical malignancy related to posttreatment prognosis.

Adult↗
PubMed2006

A case of dysferlinopathy presenting choreic movements.

Mutations in the dysferlin gene cause limb-girdle muscular dystrophy type 2B (LGMD2B). The involvement of the central nervous system in dysferlinopathy has not been described. We describe the clinical features of a patient with LGMD2B associated with dysferlin mutations (homozygous G3370T) who presented progressive choreic movements. The patient had no evidence of other causes of chorea. It is suggested that the chorea may be associated with the altered expression of the brain isoform of dysferlin.

Brain↗
PubMed2006

FDG PET in solitary metastastic/secondary tumor of the kidney: a report of three cases and a review of the relevant literature.

Metastatic tumors or secondary lymphoma of the kidney are rare and can often be missed on conventional computed tomography (CT) imaging. On the other hand, many types of metastatic tumor or lymphoma can be detected clearly as hotspots of elevated uptake on FDG PET. However, excreted FDG present in the urinary tract mimics these findings and interferes with image reading. Careful investigation of the renal cortex by FDG PET and review of anatomical images, such as the findings of CT and MRI, have important roles in the detection of renal tumor. Here, we present three cases of solitary metastatic/secondary tumor of the kidney, and discuss the features of the lesions on FDG PET in comparison with their appearance on CT.

Adolescent↗
PubMed2006

Evaluation of the relationship between physiological FDG uptake in the heart and age, blood glucose level, fasting period, and hospitalization.

OBJECTIVE: Positron emission tomography (PET) with fluorodeoxyglucose (FDG) is widely used for evaluation of cancer and ischemic heart disease. Recently, increased myocardial FDG uptake has been reported to be related to some types of heart disease, such as sarcoidosis. However, the physiological increased FDG uptake in the heart often mimics the abnormal high uptake in these cases. In this study, we investigated the relationships between myocardial uptake and age, blood glucose level, fasting period, and hospitalization status (inpatient vs. outpatient). METHODS: A total of 159 non-diabetic patients were enrolled in the present study. Patients were imaged on a PET/CT scanner, and a three-dimensional region of interest (ROI) was drawn on the fused PET/CT image to measure the maximum standardized uptake value (SUV(max)) of the whole left ventricle. RESULTS: No significant relationships were observed between myocardial uptake and age or fasting period. Blood glucose level showed a significant relationship (p = 0.025) with myocardial uptake, but the R-square was extremely small (r2 = 0.03). With an SUV(max) threshold of 3.0, there was no significant difference between inpatients and outpatients. However, outpatients showed a significantly higher frequency of myocardial uptake over SUV(max) of 5.0 (chi2 test: p = 0.046). CONCLUSION: It is difficult to predict the degree of physiological uptake in the heart from data regarding age, fasting period, or blood glucose level. Outpatients tend to show higher myocardial uptake than inpatients, which may make it difficult to detect abnormally increased uptake in the heart. A long fasting period, such as overnight fasting, is an inadequate means to reduce the physiological uptake of FDG in the heart.

Adolescent↗
PubMed2006

Morphologic analyses of mandible and upper airway soft tissue by MRI of patients with obstructive sleep apnea hypopnea syndrome.

STUDY OBJECTIVES: To evaluate the morphological features of the mandible and the volume of the upper airway soft tissues in determining the anatomical risk factors for the upper airway in Japanese male patients with obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: Five morphological parameters of the mandible at the mandibular base plane and three volumetric parameters of the upper airway soft tissue were analyzed using three-dimensional (3D) magnetic resonance imaging software in 31 OSAHS and 20 controls. RESULTS: There were no significant differences between the two groups in mandibular internal width (the distance between the internal right and left gonia [IRG and ILG]) and mandibular bony thickness. However, the patients with OSAHS had a significantly wider mandibular divergence (the angle between the spina mentalis (SM)- IRG line and SM- ILG line), a smaller mandibular internal length (the perpendicular distance from SM to the RG- LG line), and a smaller area than the normal subjects at the mandibular base plane. There were no significant differences in these morphological parameters for the mandible between obese and nonobese OSAHS patients. The volumes of the tongue, soft palate, and lateral pharyngeal walls were not significantly different between the OSAHS and the control groups. CONCLUSIONS: Japanese male OSAHS patients had specific anatomical features in the bottom part of the mandible; however, obesity seemed to be a less significant risk factor. Investigators and clinicians must realize that ethnicity may modify the effects of obesity and abnormal craniofacial anatomy as risk factors for the pathogenesis of OSAHS.

Asian People↗
PubMed2006

Atlantoaxial osteoarthritis in rheumatoid arthritis: FDG PET/CT findings.

The cervical spine is a common focus of destruction in patients with rheumatoid arthritis, and the resultant instability and neural compression represent severe complications in these patients. Evaluation of disease activity at the level of the atlantoaxial joint is important in such cases. Here, we report a 47-year-old man with a 3-year history of rheumatoid arthritis. FDG PET/CT clearly demonstrated a hot spot in the atlantoaxial area, suggesting high metabolic activity of synovitis.

Arthritis, Rheumatoid↗
PubMed2006

Types and frequencies of biliary tract variations associated with a major portal venous anomaly: analysis with multi-detector row CT cholangiography.

PURPOSE: To retrospectively determine whether major portal venous variation was more frequently associated with biliary variants, with consideration of the types and frequencies of biliary tract variations in the right and left liver lobes. MATERIALS AND METHODS: Before undergoing computed tomographic (CT) cholangiography, patients gave informed consent. The retrospective research protocol was approved, and informed consent was waived by the ethics committee. Forty-four patients aged 29-80 years who underwent multi-detector row CT cholangiography had a major portal vein variation in which the main portal vein diverged into the common trunk of the left portal vein and right anterior sectorial portal vein. One hundred fifty-eight consecutive patients aged 26-89 years who did not have this variation served as the control group. Three radiologists retrospectively evaluated the confluence pattern of the bile duct, the relationship between this pattern and the portal vein, and the major branching pattern of the portal vein. Pearson chi2 and Fisher exact tests were performed to identify significant differences between the two patient groups. RESULTS: The classic hilar confluence pattern, where the right posterior sectorial duct connects supraportally with the right anterior sectorial duct, was less frequent in the patients with the portal vein variation than in the control subjects (32% vs 73%, P < .05). The following biliary tract variations were identified more frequently in the variation group than in the control group (P < .05): right posterior sectorial duct joining left hepatic duct with a supraportal course (34% vs 12%), right posterior sectorial duct joining right anterior sectorial duct with an infraportal course (13% vs 4%), right posterior sectorial duct following an infraportal course (23% vs 8%), and left lateral segmental ducts caudal to the umbilical portion of the portal vein (14% vs 3%). The right hepatic duct, which receives all biliary ducts from the right lobe, was significantly less frequently developed in the variation group (46% vs 79%, P < .05). In addition, retroportal bile ducts were seen in four patients with the portal vein variation (P < .05). CONCLUSION: Bile duct configurations in patients with portal vein variation were significantly different from those in control subjects.

Adult↗
PubMed2006

Effective treatment with levodopa and carbidopa for hypomyelination with atrophy of the basal ganglia and cerebellum.

Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a rare leukoencephalopathy presenting in the infantile period and characterized by diffuse cerebral hypomyelination, and atrophy of the basal ganglia and cerebellum. As patients with H-ABC lack remarkable laboratory findings, the diagnosis is based on brain magnetic resonance imaging findings alone. Only eight cases have been reported in the literature, and thus the natural course and treatment of this disease are not fully understood. We report a 35-month-old boy with H-ABC who had hemidystonia, hypomyelination, and cerebellar ataxia. We diagnosed H-ABC after considering a thorough differential diagnosis, excluding other diseases involving hemidystonia, hypomyelination, and cerebellar ataxia. Furthermore, technetium-99m ethyl cysteinate dimmer-single-photon emission computerized tomography (Tc-ECD-SPECT) and positron emission tomography with fluorodeoxyglucose (18)F (FDG-PET) revealed decreased blood flow and glucose metabolism in the bilateral lenticular nucleus, thalamus, and cerebellum. A peroral levodopa preparation containing carbidopa (levodopa-carbidopa) was effective at ameliorating and stopping the progression of the patient's dystonia (final effective doses: levodopa, 200 mg/day and carbidopa, 20 mg/day). This is the first case report of a Japanese patient with H-ABC and treatment for this disease. Levodopa-carbidopa may be an effective treatment for H-ABC.

Administration, Oral↗
PubMed2005

Edema in the retropharyngeal space associated with head and neck tumors: CT imaging characteristics.

To determine computed tomographic (CT) imaging characteristics of retropharygeal edema, we reviewed CT images in 18 patients with head and neck tumors. Retropharyngeal edema spread craniocaudally between soft palate and upper half of thyroid cartilage in all patients. No edema fluid extended above soft palate and below thyroid cartilage. Horizontally, it spread symmetrically in ten and asymmetrically in eight patients. Predominance in asymmetrical retropharyngeal edema was found on the same side as that of unilateral predominance both in lymph nodes enlargement and jugular vein stenosis/occlusion. All patients had edema also in other cervical spaces. Edema of retropharyngeal and other spaces fluctuated synchronously. In 14 patients, as primary lesion and/or cervical lymph nodes regressed, retropharyngeal edema disappeared or decreased. Retropharyngeal edema had some imaging characteristics. With knowledge of that, we could avoid diagnostic confusion when evaluating head and neck CT images.

Adult↗
PubMed2005

The effects of copper-histidine therapy on brain metabolism in a patient with Menkes disease: a proton magnetic resonance spectroscopic study.

We report on metabolic changes in the brain of a boy with Menkes disease. He was treated with parenteral copper (Cu)-histidine supplementation, from 5 months of age, and assessed with proton magnetic resonance spectroscopy ((1)H-MRS). The single-voxel (1)H-MRS before treatment revealed an accumulation of lactate and a reduced N-acetyl aspartate (NAA)/total creatine (tCr) ratio with a z-score of -3.0. During treatment, the lactate signal faded away, whereas the NAA signal gradually increased to a z-score of -1.5 at 120 days of treatment. The choline/tCr ratio did not deviate much initially (z-score +0.5), but the ratio increased markedly during treatment (z-score +4.8). Consequently, the Cu-histidine therapy initiated after the critical period still improved the neuronal metabolism, suggesting that some Cu was delivered to neurons. Nevertheless, the brain atrophy, impaired myelination, and severe neurological symptoms were not ameliorated.

Brain↗
PubMed2005

Time-related changes in computed tomographic appearance and pathologic findings after radiofrequency ablation of the rabbit lung: preliminary experimental study.

PURPOSE: To evaluate correlations between computed tomographic (CT) appearance and pathologic findings after radiofrequency (RF) ablation of lungs and to determine whether CT appearance could predict the extent of the effective therapeutic area. MATERIALS AND METHODS: The lungs of 14 rabbits were subjected to RF ablation and CT scans were obtained immediately and at various intervals thereafter. Four rabbits were killed immediately after the initial CT imaging (n = 4). The remaining 10 rabbits were killed after additional CT scans at intervals of 3 days (n = 2), 1 week (n = 4), 2 weeks (n = 2), and 3 weeks (n = 2) after RF ablation. Pathologic findings were correlated with CT appearance. RESULTS: Immediately after RF ablation, a restricted area of central dense opacity enclosed by an extensive area of ground-glass opacity was noted in the ablated region on CT images. Pathologically, the former corresponded to destructive tissue and the latter corresponded to tissue with some degree of injury. After 1 week, the entire ablated region appeared as a well-demarcated homogeneous dense opacity on CT that corresponded to necrotic tissue and its surrounding rim of granulation tissue on histopathologic examination, indicating that the enclosing extensive area of ground-glass opacity on the initial CT scan represented an ongoing necrosis. Within 2-3 weeks, the ablated region gradually contracted on the CT images, representing a tissue repairing process in which the granulation tissue was encroaching on the inner necrotic tissue. CONCLUSION: Ground-glass opacity of the ablated region on CT immediately after RF ablation represents an ongoing necrosis.

Animals↗
PubMed2003

Characteristics of Rathke's cleft cyst in MR imaging.

PURPOSE: Symptoms, macroscopic appearances and microscopic findings of Rathke's cleft cysts with magnetic resonance (MR) imaging. PATIENTS AND METHODS: We analyzed the data from 31 patients with pathologically confirmed Rathke's cleft cysts. MR appearances were evaluated on T1WI, T2WI and contrast T1WI. Symptoms, macroscopic appearances and pathological findings were obtained from available medical records. We analyzed the images according to the following criteria: 1. findings on the location and shape of the lesions and form of the lesional wall; 2. the relationship between the maximum diameter of the lesions and symptoms; 3. the relationship between MR and macroscopic appearance; 4. the sites of adjacent contrast enhancement. RESULTS: The lesions were located mostly in both the intrasellar and suprasellar regions for a total of 87%. All lesions revealed either an oval or dumbbell shape with a smooth lesional wall. When correlated with physical symptoms, asymptomatic cases were associated with smaller lesions, while visual disturbances and dizziness were associated with relatively larger lesions. MR lesion signal intensity was related to the content of macroscopic appearance to some degree: the selected lesions showed shortening of T1 and T2 relaxation times in relation to the increase in protein concentration. This should have been macroscopically reflected in the color and turbidity of the liquid within the cyst. Adjacent contrast enhancement around the lesion was found at various sites, but anterior enhancement was most frequent. Circumferential enhancement was revealed to be derived from inflammatory changes. CONCLUSION: Rathke's cleft cyst exhibits a varied MR signal. It may be difficult to differentiate from craniopharyngioma from the intensity alone.

Adolescent↗
PubMed2003

Metabolic properties of band heterotopia differ from those of other cortical dysplasias: a proton magnetic resonance spectroscopy study.

PURPOSE: To assess the biochemical properties of band heterotopia in comparison with other cortical developmental malformations (CDMs) by using proton magnetic resonance spectroscopy (1H-MRS). METHODS: We performed localized single-voxel 1H-MRS studies on 13 patients [five band heterotopia (BH), two focal cortical dysplasia (CD), two unilateral CD, one bilateral perisylvian dysplasia, three hemimegalencephaly]. CDMs other than BH were categorized as CD. Spectra were acquired from volumes of interest (VOIs) localized in the CD and in normal-appearing cortex on the contralateral side. In BH patients, the VOIs were the external cortex and the laminar heterotopia. For the BH study, spectra also were obtained from the cortex of age-matched normal volunteers. RESULTS: The spectra of CD lesions were characterized by significantly lower ratios of N-acetyl aspartate to creatine (NAA/Cr) and by higher choline to Cr (Cho/Cr) ratios than in the contralateral remote cortex (p = 0.01 and 0.01, respectively). The NAA/Cr and Cho/Cr ratios of the external cortex of BH were not significantly different from those of normal volunteers. The NAA/Cr ratio of the laminar heterotopia was not significantly different from that of the external cortex (p = 0.12) or normal volunteers (p = 0.60), whereas Cho/Cr was significantly higher in laminar heterotopias than in the external cortex (p = 0.04) or controls (p = 0.03). CONCLUSIONS: 1H-MRS can distinguish between the metabolic properties of BH and CD.

Adolescent↗