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The present study aimed to evaluate whether the use of a smoothing filter would improve the image quality in pediatric 99mTc-dimercaptosuccinic acid (99mTc-DMSA) scintigraphy. We retrospectively reviewed 31 kidneys in 16 consecutive pediatric patients aged 10 months to 14 years. The administered dose was calculated using a weight-based method. Two reviewers randomly evaluated the original planar posterior images and smoothing filter image; they assessed image quality and performed defect evaluations. The evaluation of visual image quality yielded significantly better results for the smoothing filter images than for the original images. Although the smoothing filter images were slightly inferior to the original images in terms of edge sharpness, no significant difference was observed in the defect evaluation. We confirmed that 99mTc-DMSA scintigraphy with a smoothing filter yielded reduced image noise, while maintaining defect evaluation performance and improving image quality. [ABSTRACT FROM AUTHOR]

We reviewed the thoracic vertebra MRI of patients whose chief complaint was dorsalgia (or + lower back dorsalgia). Thoracic vertebra MRI of 103 patients had dorsalgia as the chief complaint mainly or sometimes in 134 (man 61, woman 73) and had led them to consult an orthopaedic specialist. A difference was seen in the cavity diameter under the posterior arachnoid in 103 and 31 which led to MRI scan of the thoracic vertebra. The cavity diameter was equal to or more than 0.55 posterior space, equal to or less than 0.43 abdominal side space. We reviewed the thoracic vertebra MRI of the patients whose the chief complaint was dorsalgia (or lower back dorsalgia). On the thoracic vertebra sagittal T2w MR scans we obtained eccentricities from the center to the thoracic ventral aspect and to the dorsal aspect at the widest diameter of the spinal canal. The eccentricities were calculated as ratios of the diameter of the spinal canal at the maximal occipitofrontal diameter to the dorsal subarachnoid space diameter, and to the ventral subarachnoid space diameter. Spinal cord imaging was done by exclusion to the abdominal side because the cavity diameter under the posterior arachnoid was wide. The ventral root was towed and the dorsal root was assumed to be bent. [ABSTRACT FROM AUTHOR]

Studies the physiological mechanisms underlying sleep during dreaming. Sleep onset rapid eye movement induction through the Sleep Interruption Technique; Dream property evaluation using the Dream Property Scale.

Three patients with subacute ischemic cerebral infarction examined by SPECT withTc-ECD and PET within the same day showed signs of luxury perfusion in the subacute phase, which is between 9 to 20 days after the onset. ATc-HMPAO SPECT study was also performed within 2 days of the ECD-SPECT study. ECD-SPECT images of three patients displayed a focal decreased uptake in the infarcted lesions, while in infarcted foci, there was almost equivalent or increased CBF compared to normal and unaffected areas, decreased CMRO, and high HMPAO uptake. The ECD-SPECT results were similar to those of CMRO rather than CBF, though the HMPAO-SPECT image was similar to that of CBF. In one patient, HMPAO images revealed hyperfixation of the tracer. In the chronic phase and in the acute phase before 5 days after the onset, there were no discrepancies among the ECD-SPECT, CBF, HMPAO-SPECT, and CMRO images. These observations indicated thatTc-ECD is a good indicator of damaged brain tissues in subacute ischemic infarction. They also suggested thatTc-ECD is a potential agent with which to evaluate cerebral tissue viability in some pathological states of cerebrovascular disease. The characteristics may be suitable for confirming the effects of thrombolytic therapy in acute ischemia, because these conditions often show signs of luxury perfusion when the therapy is successful. [ABSTRACT FROM AUTHOR]

By means of a high resolution PET scanner, the regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction fraction (rOEF), and metabolic rate of oxygen (rCMRO) for major cerebral gyri and deep brain structures were studied in eleven normal volunteers during an eye-covered and ear-unplugged resting condition. Regional CBF was measured by the auto-radiographic method after intravenous administration of H O. Regional OEF and rCMRO were measured by the single inhalation ofO. With MR T-weighted images as an anatomical reference, thirteen major cerebral gyri, caudate nucleus, lentiform nucleus, thalamus, midbrain, pons, cerebellum and vermis were defined on the CMRO images. Values were read by using circular regions of interest 16 mm in diameter. The posterior part of the cingulate gyri had the highest rCBF and rCMRO values among brain structures, followed by the lentiform nucleus, the cerebellum, the caudate nucleus, and the thalamus. Parahippocampal gyri had the lowest rCBF and rCMRO values amongthe cortical gyri.RegionalOEFforthepontinenuclei (0.34 ± 0.04), the midbrain (0.35 ± 0.05), the parahippocampal gyri (0.35 ± 0.04 for the right and 0.37 ± 0.05 for the left), and the thalami (0.37 ± 0.05 for the right and 0.36 ± 0.04 for the left) were significantly lower than the mean OEF for the cerebral cortices (0.42 ± 0.04) (p < 0.05 or less). The global CBF and CMRO were consistent with those obtained by the Kety-Schmidt method. Although several limitations to the quantification derived from an inadequate spacial resolution remain unsolved, the performance of the present PET scanner and the method for the quantification employed provide regional estimates of brain circulation and oxygen metabolism more acurately than the PET system and the steady state method previously used. [ABSTRACT FROM AUTHOR]

We studied the brain uptake of amino acid in a patient with acute cerebral infarction with L-[2-(F-18)] fluorophenylalanine and positron emission tomography. The increased accumulation of the ligand was specifically found in the peri-infarct area where oxygen metabolism was still maintained but decreased later in the 72-day follow-up period. The kinetic analysis revealed that increased accumulation was not due to increased transport from the blood to the brain but to delayed washout from the brain to the blood. Although the mechanism is still unknown, abnormally high accumulation of L-[F-18]fluorophenylalanine may predict delayed neuronal changes after ischemic insults of the brain. [ABSTRACT FROM AUTHOR]

To elucidate the mechanism of large neutral amino acid (LNAA) transport in cerebral gliomas and to evaluate the clinical usefulness of positron emission tomography (PET) with fluorine-18 fluorophenylalanine (F-Phe), we examined 18 patients with cerebral glioma using dynamic PET andF-Phe. By employing two-compartment model analysis, the influx rate K, the efflux rate k and the distribution volume ( V) ofF-Phe were estimated in tumour tissue and contralateral normal grey matter.F-Phe showed increased accumulation in tumour tissue regardless of the grade of malignancy in all patients. The rate of uptake ofF-Phe in high-grade glioma was significantly higher than in low-grade glioma ( P <0.05). However, it was difficult to evaluate the tumour grade only from theF-Phe accumulation in individual cases. Values of K and V were significantly increased in the tumour tissue. The K value of the tumour tissue tended to decrease with increasing LNAA concentration in plasma. Therefore, influx ofF-Phe into tumour tissue is mainly related to the carrier-mediated active transport. It is concluded that PET withF-Phe is of clinical value for tumour detection rather than assessment of tumour malignancy. [ABSTRACT FROM AUTHOR]

A method has been developed to quantitate regional cerebral blood blow (rCBF) using iodine-123-labelled N-isopropyl- p-iodoamphetamine (IMP). This technique requires only two single-photon emission tomography (SPET) scans and one blood sample. Based on a two-compartment model, radioactivity concentrations in the brain for each scan time (early: t; delayed: td) aredescribed as: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qamaaBa% aaleaacaWG0baabeaakmaabmaabaGaamiDamaaBaaaleaacaWGLbaa% beaaaOGaayjkaiaawMcaaiabg2da9iaadAgacqWIpM+zcaWGdbWaaS% baaSqaaiaadggaaeqaaOWaaeWaaeaacaWG0bWaaSbaaSqaaiaadwga% aeqaaaGccaGLOaGaayzkaaGaey4LIqSaamyzamaalaaabaGaamOzaa% qaaiaadAfadaWgaaWcbaGaamizaaqabaaaaOGaamiDamaaBaaaleaa% caWGLbaabeaaaaa!4D64!\[C_t \left( {t_e } \right) = fC_a \left( {t_e } \right) \otimes e\frac{f}{{V_d }}t_e \] and % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qamaaBa% aaleaacaWG0baabeaakmaabmaabaGaamiDamaaBaaaleaacaWGKbaa% beaaaOGaayjkaiaawMcaaiabg2da9iaadAgacqWIpM+zcaWGdbWaaS% baaSqaaiaadggaaeqaaOWaaeWaaeaacaWG0bWaaSbaaSqaaiaadsga% aeqaaaGccaGLOaGaayzkaaGaey4LIqSaamyzamaalaaabaGaamOzaa% qaaiaadAfadaWgaaWcbaGaamizaaqabaaaaOGaamiDamaaBaaaleaa% caWGKbaabeaaaaa!4D61!\[C_t \left( {t_d } \right) = fC_a \left( {t_d } \right) \otimes e\frac{f}{{V_d }}t_d \] respectively, where ⊗ denotes the convolution integral; C( t), the arterial input function; f rCBF; and V, the regional distribution volume of IMP. Calculation of the ratio of the above two equations and a 'table look-up' procedure yield a unique pair of rCBF and V for each region of interest (ROI). A standard input function has been generated by combining the input functions from 12 independent studies prior to this work to avoid frequent arterial blood sampling, and one blood sample is taken at 10 min following IMP administration for calibration of the standard arterial input function. This calibration time was determined such that the integration of the first 40 min of the calibrated, combined input function agreed best with those from 12 individual input functions (the difference was 5.3% on average). This method was applied to eight subjects (two normals and six patients with cerebral infarction), and yielded rCBF values which agreed well with those obtained by a positron emission tomography HO autoradiography method. This method was also found to provide rCBF values that were consistent with those obtained by the non-linear least squares fitting technique and those obtained by conventional microsphere model analysis. The optimum SPET scan times were found to be 40 and 180 min for the early and delayed scans, respectively. These scan times allow the use of a conventional rotating gamma camera for clinical purposes. V values ranged between 10 and 40 ml/g depending on the pathological condition, thereby suggesting the importance of measuring V for each ROI. In conclusion, optimization of the blood sampling time and the scanning time enabled quantitative measurement of rCBF with two SPET scans and one blood sample. [ABSTRACT FROM AUTHOR]

Fluid-attenuated inversion-recovery (FLAIR) sequences have been reported to provide high sensitivity to a wide range of central nervous system diseases. To our knowledge, however, FLAIR sequences have not been used to study patients with acute cerebral infarcts. We evaluated the usefulness of FLAIR sequences in this context. FLAIR sequences were acquired on a 0.5 T superconducting unit within 8 h of the onset in 19 patients (aged 26–80 years) with a total of 23 ischaemic lesions. The images were reviewed retrospectively by three neuroradiologists, and the FLAIR images were compared with T2-weighted fast spin-echo images. All but one of the ischaemic lesions involving grey matter was clearly demonstrated on FLAIR images as increased signal intensity in cortical or central grey matter. FLAIR images were particularly useful for detecting the hyperacute cortical infarcts within 3 h of onset, which were not readily detected on the spin-echo images. In 9 of 11 patients with complete proximal occlusion, the distal portion of the cerebral artery was visible as an area of high signal intensity on FLAIR images. [ABSTRACT FROM AUTHOR]

Cerebral blood flow (CBF), oxygen metabolism (CMRO), and glucose metabolism (CMRGlc) were measure using positron emission tomography in five patients diagnosed as having mitochondrial encephalomyopathy. The molar ratio between the oxygen and glucose consumptions was reduced diffusely, as CMRO was markedly decreased and CMRGlc was slightly reduced. The CBF showed less changes. The CBF increase on hypercapnia was smaller than normal, though this was not significant. CBF with hypocapnia demonstrated a significant reduction compared with the normal. These results suggest that oxidative metabolism is imparied and anaerobic glycolysis relatively stimulated, due to a primary defect of mitochondrial function, and that mild lactic acidosis occurs in brain tissue because of impaired utilisation of pyruvate in the TCA cycle. As these findings appear to indicate directly a characteristic of this disease, such measurements may be a useful tool for assessment of the pathophysiology and for diagnosis of mitochondrial encephalomyopathy. [ABSTRACT FROM AUTHOR]

A questionnaire concerning their sleep-related lifestyle and mental health was mailed to people aged in their twenties to fifties living in the Fukushima (North East), Tokyo (Central, Metropolitan) and Okayama (West) areas of Japan. We classified the sleeping pattern of 3642 people (1702 men, 1940 women; mean age 41.3 ± 10.67) by multivariational analyses (factor analysis and cluster analysis). They were classified into six groups and defined as ‘poor sleeper group’ (30.0%), ‘good sleeper group’ (28.3%), ‘long sleeper group’ (8.2%), ‘short sleeper group’ (18.5%), ‘irregular sleeper group’ (11.3%), and ‘Delayed Sleep Phase Syndrome group’ (3.7%) based on their characteristics of the factor pattern. [ABSTRACT FROM AUTHOR]

We have encountered a ruptured aneurysm as a filling defect in cisternal blood on CT in patients with acute subarachnoid haemorrhage (SAH), as high-attenuation blood can act as a contrast medium. We term this finding the “filling defect sign”. To evaluate the usefulness of the sign in the diagnosis of a ruptured aneurysm, we retrospectively analysed CT with 10-mm-thick slices obtained within 2 days of onset of SAH in 100 consecutive patients. The sign was observed in 30 of the 100 patients, and in 13 (68 %) of 19 patients with a ruptured aneurysm more than 10 mm in diameter. The filling defect sign is useful in predicting the site of rupture. [ABSTRACT FROM AUTHOR]

Examines the relationship between lifestyle and pattern of nocturnal rectal temperature. Observation of lowest level of rectal temperature during daytime; Performance of polysomnography; Assessment of habits, attitudes and sleep hygiene.

We report an anterior cranial fossa dural arteriovenous fistula with a varix mimicking an aneurysm on CT and MRI. [ABSTRACT FROM AUTHOR]