[Imaging of the brain tumor: overview].
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
Kouichirou Okamoto
Publications and source records attributed to Kouichirou Okamoto.
Quantitative evaluation of brainstem involvement in multiple system atrophy by diffusion-weighted MR imaging.
In multiple system atrophy (MSA), symptoms associated with dysfunctions of the brainstem and autonomic nervous system are important prognostic factors. We investigated brainstem involvement in 12 patients with MSA with predominant cerebellar symptoms (MSA-C) (mean age, 56.3 +/- 9.9 years, median disease duration, 3 years), and 11 controls (57.6 +/- 12.0 years) matched for age using diffusion-weighted MR imaging (DWI). We demonstrated that apparent diffusion coefficients (ADCs) in the pons and middle cerebellar peduncle of MSA-C patients are significantly higher than those of normal controls even though the patients are in the early stage of the disease. Furthermore, we demonstrated that increased ADC values correlated well with the disease duration. The current study demonstrated that DWI is a useful noninvasive method for the quantitative evaluation of the brainstem involvement in MSA-C patients.
Aged↗
Whole-blood manganese levels and brain manganese accumulation in children receiving long-term home parenteral nutrition.
Recent reports attribute neurological and cerebral disorders to the accumulation of manganese (Mn) in the brain in patients receiving home parenteral nutrition (HPN). It is desirable to control the amount of Mn delivered to these patients, but a suitable method for monitoring an individual's Mn status and assessing Mn accumulation remains debatable. The aim of this study was to evaluate whether whole-blood manganese levels (WB-Mn) correlate with the accumulation of Mn in the brains of children who receive long-term HPN, using magnetic resonance imaging (MRI) of the brain. Six patients who had received HPN (duration of HPN, 18-137 months) were included in this study. The daily parenteral doses of Mn were calculated while on HPN. WB-Mn was measured and T1-weighted MRI of the brain was obtained for each patient with a 1.5-T MR imager. Twelve months after the withdrawal of Mn from HPN, measurements of WB-Mn and brain MRI were repeated in all patients except for one who was lost after initial examination. The same examinations were performed on an additional patient who had been successfully weaned off a 179 month course of HPN 20 months prior to the initial examination. The parenteral dose of Mn while receiving HPN ranged from 15.7 to 91.5 micro g/kg/day. Initially, MRI showed hyperintensity in the globus pallidus in all patients and in the anterior pituitary in one patient. WB-Mn was elevated in four patients, but was in the normal range in the remaining three. Following subsequent measurements 12 months later, WB-Mn was normal in all patients and MRI hyperintensity remained in the globus pallidus in one patient. One patient was lost after the initial examinations. WB-Mn does not necessarily correlate with the accumulation of Mn in the brain. Periodic MRI should be performed in patients receiving long-term NPN to monitor for excessive Mn accumulation in the brain.
Adolescent↗
Extracerebral ectopic mass with huge cysts in the anterior cranial cavity.
In the present study, an unusual example of malformation in a 9-day-old-girl, in whom an extracerebral ectopic mass with cysts was found in the anterior cranial cavity, is reported. The brain proper was well developed. The mass was connected to the cerebral base and consisted of neuroglial tissue showing various characteristics of differentiation, including cerebellar cortex and monoaminergic neurons. The ectopia may have developed from the mediobasal portion of the embryonic telencephalon.
Child↗
Primary frontal-lobe germinoma appearing as a large cyst.
In the present case, a primary frontal-lobe germinoma in a 20-year-old man is reported. This is the first such case to be investigated by autopsy. The tumor appeared on a CT scan as a large cystic lesion in the frontal-lobe white matter. At autopsy, the typical two-cell histology pattern was seen mainly in the area of the cyst wall. Although cyst formation is a frequent feature of germinomas, the presence of a large cystic lesion in the cerebral white matter, as demonstrated in the present case, is very rare. The present case provides further radiographic data that might be useful for the future diagnosis of this tumor, which is radiosensitive and potentially curable.
Adult↗
MR findings with dynamic evaluation in Riedel's thyroiditis.
We reported the findings on MRI in a patient with proven Riedel's thyroiditis. The lesion was seen as slightly heterogeneous hypointensity on both T1- and T2-weighted images and had a mild enhancement after administration of gadpentate dimeglumine (Gd-DTPA). Dynamic MR study showed gradual increase in signal intensity of the lesion. These findings were different from those of thyroid neoplasms and were considered to reflect the mixture of inflammatory cells infiltration and fibrosis of Riedel's thyroiditis.
Contrast Media↗
Clinical and imaging features of distended scapulothoracic bursitis: spontaneously regressed pseudotumoral lesion.
OBJECTIVE: To describe clinical and imaging findings of distended scapulothoracic bursitis without scapular snapping, which is often confused with a soft tissue tumor. METHODS: Nine patients (6 male, 3 female; age range: 50-73 years; mean age = 67 years) with distended scapulothoracic bursitis diagnosed by clinical and magnetic resonance (MR) imaging findings were studied. The results of a histologic examination were available in 1 case. RESULTS: All patients presented with painless palpable masses below the scapula, and the initial diagnoses were soft tissue tumors. On MR images, the lesions were 5.5 to 12 cm in maximum diameter (mean = 7.7 cm) and well-demarcated cystic masses situated in the subscapular region between the serratus anterior and the chest wall. There was no solid portion on the cyst walls. The findings of hemorrhage within the bursae were present in all cases. Every mass regressed in size spontaneously after a few to several weeks, and no lesions revealed any malignant findings of sarcomas. CONCLUSIONS: Distended scapulothoracic bursae without scapular snapping resemble soft tissue tumors. They have some specific MR findings; therefore, precise recognition of these findings is important to avoid misdiagnoses and unnecessary treatments.
Aged↗
MR features of diseases involving bilateral middle cerebellar peduncles.
BACKGROUND AND PURPOSE: Distribution of lesions or involvement of specific anatomic sites can suggest the diagnosis of disease. The purpose of this study was to investigate what diseases affect both middle cerebellar peduncles (MCPs) and to evaluate other MR features for differential diagnosis. METHODS: MR findings of 27 patients (14 male and 13 female; age range, 4-77 years [mean, 48.5 years]) with bilateral MCP lesions were retrospectively studied. RESULTS: Neurodegenerative diseases were the most frequent diagnoses (n = 11 [41%]: sporadic olivopontocerebellar atrophy, eight; Shy-Drager syndrome, one; spinocerebellar ataxia, two). Also included were metabolic diseases (n = 6 [22%]: adrenoleukodystrophy, two; Wilson disease, two; cirrhosis of the liver, one; and hypoglycemia, one); cerebrovascular diseases, including posterior reversible encephalopathy syndrome (n = 3 [11%]: infarction, one; hypertensive encephalopathy, one; cyclosporin-A encephalopathy, one), demyelinating and inflammatory diseases (n = 4 [15%]: multiple sclerosis, one; acute disseminated encephalomyelitis, one; Behçet disease, one; and HIV encephalopathy, one), and neoplasms (n = 3 [11%]: lymphoma, one; glioma, one; meningeal carcinomatosis, one). All patients showed symmetrical T2 hyperintensity in both MCPs, except for one with malignant lymphoma. Marked atrophy in the posterior fossa was characteristically seen in neurodegenerative diseases. Enlargement of the pons was observed in hypertensive encephalopathy and neoplasms but absent in meningeal carcinomatosis. Lesions were restricted in the posterior fossa in eight patients with neurodegenerative diseases and one with brain stem glioma. Other patients had supratentorial lesions. CONCLUSION: Symmetricity of MCP lesions, morphologic change of the posterior fossa structures, and distribution of other lesions are helpful in the differential diagnosis.
Adolescent↗
Survival benefit of stereotactic radiosurgery for metastatic brain tumors in patients with controlled primary lesions and no other distant metastases.
The prognosis of patients with metastatic brain tumors has been very poor so far because most patients with metastatic brain tumors had other metastatic lesions and/or active primary lesions. Moreover, if no active lesions existed, local control of conventional radiation therapy was not so good, which also led to the poor prognosis. Thus, we conducted the current study concerning whether survival benefit existed in patients with controlled primary lesions and no other distant metastases, who were treated with stereotactic radiosurgery (SRS), a superior method for local control, for metastatic brain tumors. Seventy-seven patients with 90 metastatic brain tumors were treated with SRS between August 1999 and August 2001, at Tokyo Metropolitan Komagome Hospital, Japan. Of these, 10 patients with 17 metastatic brain tumors had primary lesions controlled and no other distant metastases were included in the current study. The median prescribed isocenter dose was 30 Gy (30-45 Gy) and the median prescribed peripheral dose was 25 Gy (12-30 Gy). One-year and 3-year local control rates were 90.0% and 90.0%, respectively. One-year and 3-year overall survival rates were 88.9% and 51.9%, respectively. These results suggest that SRS for metastatic brain tumors does have a survival benefit in patients with controlled primary lesions and no other distant metastases, which means that we should not treat these patients with palliative intent but pursue longer survival.
Adult↗
Mimics of brain tumor on neuroimaging: part I.
Brain tumor is a distinct pathological entity that differs from other diseases, including cerebrovascular, demyelinating, inflammatory, infectious, and various miscellaneous diseases. Insidious onset and gradual progression of signs and symptoms are common in patients with brain tumors, whereas the onset of cerebrovascular diseases is usually acute or sudden. Patients with demyelinating, inflammatory, or infectious diseases show subacute onset. Differentiation of brain tumors from other disorders is usually possible from the clinically and radiologically characteristic features. However, in some diseases other than brain tumors, an atypical clinical course and/or radiological findings may suggest or simulate those of brain tumors. The diagnosis of brain tumor is confirmed histopathologically, and appropriate therapies are given to the patient based on the histopathological type and grade of the tumor. In order to obtain a specimen for histopathological examination, surgical intervention is required. Other diseases are usually diagnosed clinically and radiologically. Invasive procedures should be avoided in making a diagnosis. Therefore, differentiation of brain tumors from other diseases is a critical issue for neuroimaging. Detailed inspection of images is necessary, and characteristic findings, and additional imaging methods, such as diffusion-weighted imaging, are often helpful for the differential diagnosis. We assess the imaging findings of diseases simulating brain tumors and review the literature.
Adult↗
Mimics of brain tumor on neuroimaging: part II.
Brain tumor is a distinct pathological entity that differs from other diseases, including cerebrovascular, demyelinating, inflammatory, infectious, and various miscellaneous diseases. Insidious onset and gradual progression of signs and symptoms are common in patients with brain tumors, whereas the onset of cerebrovascular diseases is usually acute or sudden. Patients with demyelinating, inflammatory, or infectious diseases show subacute onset. Differentiation of brain tumors from other disorders is usually possible from the clinically and radiologically characteristic features. However, in some diseases other than brain tumors, an atypical clinical course and/or radiological findings may suggest or simulate those of brain tumors. The diagnosis of brain tumor is confirmed histopathologically, and appropriate therapies are given to the patient based on the histopathological type and grade of the tumor. In order to obtain a specimen for histopathological examination, surgical intervention is required. Other diseases are usually diagnosed clinically and radiologically. Invasive procedures should be avoided in making a diagnosis. Therefore, differentiation of brain tumors from other diseases is a critical issue for neuroimaging. Detailed inspection of images is necessary, and characteristic findings, and additional imaging methods, such as diffusion-weighted imaging, are often helpful for the differential diagnosis. We assess the imaging findings of diseases simulating brain tumors and review the literature.
Brain Neoplasms↗