Diastolic blood pressure influences cerebrovascular reactivity measured by means of 123I-iodoamphetamine brain single photon emission computed tomography in medically treated patients with occlusive carotid or middle cerebral artery disease.

Objective: Impaired cerebrovascular reactivity (CVR) to vasodilating agents is a predictor of the onset and prognosis of ischemic stroke. It is realized that the CVR improves or worsens when measured periodically during the clinical course in medically treated patients with occlusive cerebrovascular disease. In these patients, we investigated the possible relationship between the interval change in CVR and that in systemic blood pressure (BP).

A phase I/II trial of a WT1 (Wilms' tumor gene) peptide vaccine in patients with solid malignancy: safety assessment based on the phase I data.

Objective: We conducted a phase I study to investigate the safety of a weekly WT1 tumor vaccine therapy in patients with solid tumors that had been refractory to all other anti-cancer therapies.

Methods: Skin-test-negative patients were intradermally injected weekly for 12 weeks with 3.0 mg of an HLA-A*2402-restricted modified 9-mer WT1 peptide emulsified in Montanide ISA51 adjuvant.

Acute effects of cigarette smoking on global cerebral blood flow in overnight abstinent tobacco smokers.

We examined whether cerebral vascular reactivity to 5% CO2/95% O2 would be a useful, independent measure of effects of tobacco smoking on global cerebral blood flow (gCBF). The acute effects during smoking one's favorite brand of cigarettes were determined after overnight tobacco abstinence. Positron emission tomography was used to quantitatively measure gCBF using H(2)15O in 10 right-handed young-adult male volunteer tobacco smokers.

Effect of CT acquisition parameters in the detection of subtle hypoattenuation in acute cerebral infarction: a phantom study.

Background And Purpose: We evaluated the effects of varying tube voltage, current per rotation, and section thickness on detectability of 2- and 4-Hounsfield unit (HU) differences on brain CT between normal and ischemic gray matter within 6 hours of ischemia onset, by using a low-contrast phantom.

Methods: The phantom with an attenuation of 36 HU corresponding to normal gray matter contained 2 sets of spheres (34 HU and 32 HU) corresponding to the early CT signs of ischemic brain and complete infarction, respectively. The reproducibility of the CT numbers and the contrast-to-noise ratio (CNR), defined as the CT number difference between the background (36 HU) and the spheres (34 HU or 32 HU) divided by the SD of the background CT number were measured.

Relationship between cerebral circulatory reserve and oxygen extraction fraction in patients with major cerebral artery occlusive disease: a positron emission tomography study.

Background And Purpose: The present study examined the relationship between circulatory and metabolic reserve in patients with hemodynamic impairment.

Methods: Positron emission tomography was used to investigate 40 patients with major cerebral artery occlusive disease. The ratio of cerebral blood volume to cerebral blood flow (CBV/CBF) and vasoreactivity in response to hypercapnia (%CBF(hypercapnia)) and acetazolamide (ACZ) stress (%CBF(ACZ)) were measured to evaluate circulatory reserve.

False positive 18F-FDG PET in an ischial chondroblastoma; an analysis of glucose transporter 1 and hexokinase II expression.

We report a rare case of chondroblastoma arising from the ischium which showed an increased (18)F-FDG uptake. Chondroblastoma is an uncommon lesion and usually involves the epiphysis of long bones. However, in this case, the tumor appeared as a well-defined osteolytic lesion in the ischium on radiographs.

Usefulness of noise adaptive non-linear gaussian filter in FDG-PET study.

Objective: In positron emission tomography (PET) studies, shortening transmission (TR) scan time can improve patient comfort and increase scanner throughput. However, PET images from short TR scans may be degraded due to the statistical noise included in the TR image. The purpose of this study was to apply non-linear Gaussian (NLG) and noise adaptive NLG (ANLG) filters to TR images, and to evaluate the extent of noise reduction by the ANLG filter in comparison with that by the NLG filter using phantom and clinical studies.

Neural mechanism of residual inhibition of tinnitus in cochlear implant users.

Residual inhibition is a transient suppression of tinnitus after auditory stimulation has stopped. We used positron emission tomography to study brain regions underlying residual inhibition in three tinnitus patients with cochlear implants and six normal hearing controls. Regional cerebral blood flow was measured and compared under two conditions: with tinnitus and during the residual inhibition of tinnitus.

Pulmonary mucosa-associated lymphoid tissue type lymphoma with increased accumulation of fluorine 18-fluorodeoxyglucose on positron emission tomography.

Mucosa-associated lymphoid tissue (MALT) type lymphoma has generally been thought not to show increased fluorine 18-fluorodeoxyglucose (FDG) accumulation on positron emission tomography (PET), based on previous research. Only a limited numbers of articles have been published on this topic, however, involving a small number of cases. Although positive FDG PET results might be uncommon in this entity, a case of increased FDG accumulation in a case of MALT type lymphoma of the lung is presented.

Critical analysis of hemodynamic insufficiency by head-up tilt in patients with carotid occlusive disease.

Background: The objective of this study was to evaluate the diagnostic value of the head-up-tilt (HUT) test for detecting cerebral hemodynamic insufficiency in patients with major cerebral artery occlusion disease because such patients may benefit from extracranial - intracranial bypass surgery.

Methods And Results: In 13 cases of transient ischemic attacks in patients with carotid or middle cerebral artery occlusive disease, the HUT test was used to determine whether or not the symptoms appear during induced hypotension before investigating cerebral hemodynamics with positron emission tomography. Three of the 13 patients showed focal symptoms such as hemiparesis and limb shaking during the HUT test.

Hemodynamic influences of losartan on the brain in hypertensive patients.

The effects of angiotensin II receptor blockers on cerebral hemodynamics in humans have not been well elucidated. The present study evaluated the effects of losartan on cerebral hemodynamics in hypertensive patients using positron emission tomography. Ten patients with essential hypertension (mean age, 60.

FDG-PET imaging for chronic expanding hematoma in pelvis with massive bone destruction.

Chronic expanding hematoma is a rare presentation of a hematoma characterized by a persistent increase in size for more than a month after the initial hemorrhage. We present a 65-year-old man with a chronic expanding hematoma in his ilium who was receiving anticoagulant treatment. The patient had a delayed manifestation of a femoral neuropathy with massive bone destruction.

Metabolic penumbra of acute brain infarction: a correlation with infarct growth.

Volume expansion associated with brain infarction occurs in perfusion-diffusion mismatch of magnetic resonance imaging. We aimed at elucidating the metabolic impairment of this phenomenon with (15)O positron emission tomography and perfusion and diffusion magnetic resonance imaging. Eleven patients with acute unilateral embolic occlusion of the internal carotid or middle cerebral artery were studied within 6 hours of onset.

Radionuclide imaging metabolic activity of brown adipose tissue in a patient with pheochromocytoma.

We describe a patient with extra-adrenal pheochromocytoma and high plasma norepinephrine levels. Radionuclide images of this patient obtained using (18)F-fluorodeoxyglucose and (123)I-metaiodobenzylguanidine revealed bilateral tracer accumulation in the shoulder and lower neck. The regions of radiotracer uptake corresponded to the location of human brown adipose tissue (BAT).

Peripheral nerve schwannoma: two cases exhibiting increased FDG uptake in early and delayed PET imaging.

We present two cases of peripheral nerve schwannoma which showed an increased accumulation of 2-deoxy-[(18)F] fluoro-D-glucose (FDG) in the tumors on positron emission tomography (PET) imaging acquired at both 1 h (early phase) and 2 h (delayed phase) after FDG injection. FDG-PET scans were performed with a dedicated PET scanner (HeadtomeV/ SET2400 W, Shimadzu, Kyoto, Japan) and the PET data analyzed the most metabolically active region of interest (ROI). We set the maximum standardized uptake value (SUV max) with a cut-off point of 3.

Clinical significance of cerebrovascular reserve in acetazolamide challenge -comparison with acetazolamide challenge H2O-PET and Gas-PET.

Objective: The response of cerebral blood flow (CBF) to acetazolamide (ACZ) challenge is frequently determined in clinical settings to evaluate cerebrovascular reserve (CVR). A reduced CVR can indicate patients with occlusive cerebrovascular disease and compromised hemodynamics who may be at increased risk of cerebral ischemia. However, how precisely ACZ reflects cerebral hemodynamic impairment remains obscure.

The effect of tapping finger and mode differences on cortical and subcortical activities: a PET study.

Using positron emission tomography (PET), the brain regions recruited for the tapping movement by different fingers and different tapping modes were investigated in ten young healthy volunteers without specific finger training. Auditory-paced (2 Hz) tapping movements were performed by the index (I) or ring (R) finger alone (single-finger tapping) and by the alternate use of the I and middle (M) fingers or the R and little (L) fingers (double-finger tapping). Each subject also provided subjective rankings of perceived task difficulty, as well as muscular fatigue, among the tapping tasks.

Discrepancy between cell injury and benzodiazepine receptor binding after transient middle cerebral artery occlusion in rats.

We investigated postischemic alterations in benzodiazepine receptor, D1 dopamine receptor, and muscarinic acetylcholine receptor binding after transient middle cerebral artery (MCA) occlusion in rats using [3H]-flumazenil, [3H]-SCH23390, and [3H]-N-methyl-4-piperidyl benzilate ([3H]-NMPB), respectively, as radioligand. These ligand bindings were determined at 3 and 24 h and at 3 and 7 days after ischemia/reperfusion of MCA by using autoradiographic methods. Ischemic cell injury was clearly detected from 3 h after ischemia/reperfusion and progressively increased from 3-24 h after ischemia/reperfusion of MCA.

Long-term angiotensin-converting enzyme inhibitor perindopril therapy improves cerebral perfusion reserve in patients with previous minor stroke.

Background And Purpose: Angiotensin-converting enzyme (ACE) inhibitor-based therapy reduces the recurrence of stroke. The present study assessed the effects of long-term ACE inhibitor therapy on cerebral circulation in patients with previous minor stroke.

Methods: After a run-in period, 19 patients were randomized to ACE inhibitor therapy (n=9; 4 mg of perindopril daily; mean age, 64+/-8 years; mean systolic/diastolic blood pressure [BP]+/-SD, 133+/-12/77+/-9 mm Hg) or placebo therapy (n=10; mean age, 66+/-9 years; mean BP, 139+/-10/78+/-8 mm Hg).

Spectral analysis of 99mTc-HMPAO for estimating cerebral blood flow: a comparison with H2(15)O PET.

Cerebral blood flow (CBF) can be quantified non-invasively using the brain perfusion index (BPI), which is determined using radionuclide angiographic data obtained through the use of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO). The BPI is generally calculated using graphical analysis (GA). In this study, BPI was measured using spectral analysis (SA), and the usefulness of SA was compared with that of GA.

Cerebral hemodynamics and metabolism in adult moyamoya disease: comparison of angiographic collateral circulation.

Purpose: The extent of the hemodynamic and metabolic impairments in adult patients with moyamoya disease is still controversial. The aim of the present study was to evaluate the hemodynamic and metabolic status in relation to the development of basal moyamoya vessels (BMVs).

Methods: The cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), oxygen extraction fraction (OEF), and cerebral blood volume (CBV) were measured using PET in ten patients with ischemic adult moyamoya disease (mean age, 36.