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High-mass protostars (M$_{\star} >$ 8 M$_{\odot}$) are thought to gain the majority of their mass via short, intense bursts of growth. This episodic accretion is thought to be facilitated by gravitationally unstable and subsequently inhomogeneous accretion disks. Limitations of observational capabilities, paired with a lack of observed accretion burst events has withheld affirmative confirmation of the association between disk accretion, instability and the accretion burst phenomenon in high-mass protostars. Following its 2019 accretion burst, a heat-wave driven by a burst of radiation propagated outward from the high-mass protostar G358.93-0.03-MM1. Six VLBI (very long baseline interferometry) observations of the raditively pumped 6.7 GHz methanol maser were conducted during this period, tracing ever increasing disk radii as the heat-wave propagated outward. Concatenating the VLBI maps provided a sparsely sampled, milliarcsecond view of the spatio-kinematics of the accretion disk covering a physical range of $\sim$ 50 - 900 AU. We term this observational approach `heat-wave mapping'. We report the discovery of a Keplerian accretion disk with a spatially resolved four-arm spiral pattern around G358.93-0.03-MM1. This result positively implicates disk accretion and spiral arm instabilities into the episodic accretion high-mass star formation paradigm., Published in Nature Astronomy in 2023

Context. The massive young stellar object (MYSO) G358.93-0.03-MM1 showed an extraordinary near-infrared- to (sub-)millimetredark and far-infrared-loud accretion burst, which is closely associated with flares of several class II methanol maser transitions, and, later, a 22 GHz water maser flare. Aims. Water maser flares provide an invaluable insight into ejection events associated with accretion bursts. Although the short timescale of the 22 GHz water maser flare made it impossible to carry out a very long baseline interferometry observation, we could track it with the Karl G. Jansky Very Large Array (VLA). Methods. The evolution of the spatial structure of the 22 GHz water masers and their association with the continuum sources in the region is studied with the VLA during two epochs, pre- and post-H2O maser flare. Results. A drastic change in the distribution of the water masers is revealed: in contrast to the four maser groups detected during epoch I, only two newly formed clusters are detected during epoch II. The 22 GHz water masers associated with the bursting source MM1 changed in morphology and emission velocity extent. Conclusions. Clear evidence of the influence of the accretion burst on the ejection from G358.93-0.03-MM1 is presented. The accretion event has also potentially affected a region with a radius of ∼200 (∼13 500AU at 6.75 kpc), suppressing water masers associated with other point sources in this region. © O. S. Bayandina et al. 2022. Japan Society for the Promotion of Science, KAKEN: JP21H00032, JP21H01120, JP24340034; Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2020-780; National Astronomical Observatory of Japan, NAOJ Acknowledgements. The Ibaraki 6.7-GHz Methanol Maser Monitor (iMet) program is partially supported by the Inter-university collaborative project “Japanese VLBI Network (JVN)” of NAOJ and JSPS KAKENHI Grant Numbers JP24340034, JP21H01120, and JP21H00032 (YY). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2019.1.00768.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. In addition, publications from NA authors must include the standard NRAO acknowledgement: The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. A.M.S. acknowledges support by the Ministry of Science and Higher Education of the Russian Federation under the grant 075-15-2020-780. A.C.G. acknowledges support by PRIN-INAF-MAIN-STREAM 2017 “Protoplanetary disks seen through the eyes of new-generation instruments” and by PRIN-INAF 2019 “Spectroscopically tracing the disk dispersal evolution (STRADE)”.

We present the most complete to date interferometric study of the centimeter-wavelength methanol masers detected in G358.93-0.03 at the burst and post-burst epochs. A unique, near-IR/(sub)millimeter-dark and far-IR-loud massive young stellar object accretion burst was recently discovered in G358.93-0.03. The event was accompanied by flares of an unprecedented number of rare methanol maser transitions. The first images of three of the newly discovered methanol masers at 6.18, 12.23, and 20.97 GHz are presented in this work. The spatial structure evolution of the methanol masers at 6.67, 12.18, and 23.12 GHz is studied at two epochs. The maser emission in all detected transitions resides in a region of 1/40.″2 around the bursting source and shows a clear velocity gradient in the north-south direction, with redshifted features to the north and blueshifted features to the south. A drastic change in the spatial morphology of the masing region is found: a dense and compact "spiral"cluster detected at epoch I evolved into a disperse, "round"structure at epoch II. During the transition from the first epoch to the second, the region traced by masers expanded. The comparison of our results with the complementary Very Large Array, very long baseline interferometry, Submillimeter Array, and Atacama Large Millimeter/submillimeter Array maser data is conducted. The obtained methanol maser data support the hypothesis of the presence of spiral arm structures within the accretion disk, which was suggested in previous studies of the source. © 2022. The Author(s). Published by the American Astronomical Society. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2018.A.00031.TS. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The SMA is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica.

Radiopharmaceuticals are increasingly used for the treatment of various cancers with novel radionuclides, compounds, tracer molecules, and administration techniques. The goal of radiation therapy, including therapy with radiopharmaceuticals, is to optimise the relationship between tumour control probability and potential complications in normal organs and tissues. Essential to this optimisation is the ability to quantify the radiation doses delivered to both tumours and normal tissues. This publication provides an overview of therapeutic procedures and a framework for calculating radiation doses for various treatment approaches. In radiopharmaceutical therapy, the absorbed dose to an organ or tissue is governed by radiopharmaceutical uptake, retention in and clearance from the various organs and tissues of the body, together with radionuclide physical half-life. Biokinetic parameters are determined by direct measurements made using techniques that vary in complexity. For treatment planning, absorbed dose calculations are usually performed prior to therapy using a trace-labelled diagnostic administration, or retrospective dosimetry may be performed on the basis of the activity already administered following each therapeutic administration. Uncertainty analyses provide additional information about sources of bias and random variation and their magnitudes; these analyses show the reliability and quality of absorbed dose calculations. Effective dose can provide an approximate measure of lifetime risk of detriment attributable to the stochastic effects of radiation exposure, principally cancer, but effective dose does not predict future cancer incidence for an individual and does not apply to short-term deterministic effects associated with radiopharmaceutical therapy. Accident prevention in radiation therapy should be an integral part of the design of facilities, equipment, and administration procedures. Minimisation of staff exposures includes consideration of equipment design, proper shielding and handling of sources, and personal protective equipment and tools, as well as education and training to promote awareness and engagement in radiological protection. The decision to hold or release a patient after radiopharmaceutical therapy should account for potential radiation dose to members of the public and carers that may result from residual radioactivity in the patient. In these situations, specific radiological protection guidance should be provided to patients and carers.

Table S2â 1. Factors associated with frailty (1 point increase) among male elderly survivors in the RIAS study, 2011â 2015. (PDF 160Â kb)

Table S1. The Kihon Checklist in Japan. The checklist included a multidimensional 20-item index concerning lifestyle, motor abilities, nutrition, oral function, seclusion, and forgetfulness. (PDF 130Â kb)

Table S2â 2. Factors associated with frailty (1 point increase) among female elderly survivors in the RIAS study, 2011â 2015. These two tables were the results from a linear regression in the linear regression models. (PDF 155Â kb)

Recently introduced technologies in radiotherapy have significantly improved the clinical outcome for patients. Ion beam radiotherapy, involving proton and carbon ion beams, provides excellent dose distributions in targeted tumours, with reduced doses to the surrounding normal tissues. However, careful treatment planning is required in order to maximise the treatment efficiency and minimise the dose to normal tissues. Radiation exposure from secondary neutrons and photons, particle fragments, and photons from activated materials should also be considered for radiological protection of the patient and medical staff. Appropriate maintenance is needed for the equipment and air in the treatment room, which may be activated by the particle beam and its secondary radiation. This new treatment requires complex procedures and careful adjustment of parameters for each patient. Therefore, education and training for the personnel involved in the procedure are essential for both effective treatment and patient protection. The International Commission on Radiological Protection (ICRP) has provided recommendations for radiological protection in ion beam radiotherapy in Publication 127. Medical staff should be aware of the possible risks resulting from inappropriate use and control of the equipment. They should also consider the necessary procedures for patient protection when new technologies are introduced into clinical practice.

Studying molecular gas in the central regions of the star burst galaxies NGC4945 and Circinus enables us to characterize the physical conditions and compare them to previous local and high-z studies. We estimate temperature, molecular density and column densities of CO and atomic carbon. Using model predictions we give a range of estimated CO/C abundance ratios. Using the new NANTEN2 4m sub-millimeter telescope in Pampa La Bola, Chile, we observed for the first time CO 4-3 and [CI] 3P1-3 P0 at the centers of both galaxies at linear scale of 682 pc and 732 pc respectively. We compute the cooling curves of 12CO and 13CO using radiative transfer models and estimate the physical conditions of CO and [CI]. The centers of NGC4945 and Circinus are very [CI] bright objects, exhibiting [CI] 3P1 - 3 P0 luminosities of 91 and 67Kkms-1kpc2, respectively. The [CI] 3P1-3 P0/CO 4-3 ratio of integrated intensities are large at 1.2 in NGC4945 and 2.8 in Circinus. Combining previous CO J= 1-0, 2-1 and 3-2 and 13CO J= 1-0, 2-1 studies with our new observations, the radiative transfer calculations give a range of densities, n(H2) = 10^3-3*104^cm-3, and a wide range of kinetic temperatures, Tkin = 20 - 100K, depending on the density. Future CO J= 7-6 and [CI] 2-1 observations will be important to resolve the ambiguity in the physical conditions and confirm the model predictions.

The goal of external-beam radiotherapy is to provide precise dose localisation in the treatment volume of the target with minimal damage to the surrounding normal tissue. Ion beams, such as protons and carbon ions, provide excellent dose distributions due primarily to their finite range, allowing a significant reduction of undesired exposure of normal tissue. Careful treatment planning is required for the given type and localisation of the tumour to be treated in order to maximise treatment efficiency and minimise the dose to normal tissue. Radiation exposure in out-of-field volumes arises from secondary neutrons and photons, particle fragments, and photons from activated materials. These unavoidable doses should be considered from the standpoint of radiological protection of the patient. Radiological protection of medical staff at ion beam radiotherapy facilities requires special attention. Appropriate management and control are required for the therapeutic equipment and the air in the treatment room that can be activated by the particle beam and its secondaries. Radiological protection and safety management should always conform with regulatory requirements. The current regulations for occupational exposures in photon radiotherapy are applicable to ion beam radiotherapy with protons or carbon ions. However, ion beam radiotherapy requires a more complex treatment system than conventional radiotherapy, and appropriate training of staff and suitable quality assurance programmes are recommended to avoid possible accidental exposure of patients, to minimise unnecessary doses to normal tissue, and to minimise radiation exposure of staff.

The characteristics of disinfection by-product (DBP) formation in the distribution system of Hiroshima City were investigated. Then a model was developed for predicting DBPs based on multiple regression analysis. Potassium permanganate consumption value (KMnO 4 ), free chlorine residual concentration (Cl 2 ), pH, water temperature (WT) and residence time (RT) were confirmed to have an influence on DBP formation in the distribution system and used as independent variables. The correlation coefficients between the logarithmic values of the predicted DBPs and those of the observed DBPs were higher than 0.7. In addition, the seasonal change patterns of the predicted DBPs were very similar to those observed in some DBPs. The model is helpful for managing the DBPs in water distribution systems.

We review observational results concerning star formation and dense molecular clouds, the interstellar medium most relevant to star-formation process, as well as future prospects.

The J = 6 1,5 -6 0,6 (110.836 GHz) line of stratomesospheric O 3 has been measured employing a Nb SIS mixer receiver cooled by a closed cycle 4 K refrigerator on the Higashiyama Campus of the Nagoya University (35°N, 137°E, 70 m above sea level) since January 1992 in a sporadic manner. Relative diurnal variations of O 3 in January 1995 are in good agreement with a zero-dimensional model, ignoring transport in the 3.2 to 0.1-hPa range. Time profiles of the O 3 mixing ratio in dawn and dusk are shown with a time resolution of 6 min in the step of 0.25 of log 10 p, where p denotes the total atmospheric pressure in hectopascals. Amplitudes of seasonal variations are small at around 20, 3.2, and 0.056 hPa, respectively, and the type or phase of seasonal variations changes at these altitudes. Mixing ratio is high in summer between 10 and 5.6 hPa and is high in winter between 1.8 and 0.1 hPa. Seasonal variations of mixing ratio appear to show biennial variations between 1. and 0.1 hPa and semiannual variations above 0.032 hPa, though the period of observations is not long enough to get a definite conclusion. O 3 mixing ratio above 0.032 hPa appears to be high from March to April and from October to November.

Scatter correction (SC) has been shown to be essential for the quantification of brain perfusion in SPECT. However, in the case using the tracer showing a high activity accumulation in a small region with only a small activity in other areas of brain, the contribution of SC has yet to be studied. In this work, the impact of SC on the quantitative kinetic parameters derived from SPECT studies using a dopamine D2 receptor ligand was investigated. SPECT data were acquired dynamically with serial arterial blood sampling following intravenous injection of I-123 iodobezofuran (IBF). SC was performed with the previously validated transmission dependent convolution subtraction (TDCS) technique. Images were reconstructed by OSEM including the attenuation correction (AC), and FBP with post AC by Chang's method. Time activity curves (TACs) were generated from the striatum (STR) and occipital lobe (OCC) regions, with and without SC. Quantitative values of binding potential (BP) were then compared for four kinetic models, including the 3 compartment model (3COM), linear graphic plot (GRP), reference tissue method (RTM), and multi-regression method (MLR). SC changed both TACs of STR and OCC, and introduced significant changes in kinetic parameters, which induced the significantly increased BP in 4 kinetic models, compared to those without SC. The change in BP by SC was greater with 3COM model, than the other models. SC caused significant change in the shape of TACs in both STR and OCC, resulting in increased BP with all four kinetic methods. Likewise for the brain perfusion study, SC is required for the dopamine D2 receptor ligand studies in SPECT.

We propose a method for detecting nerve fiber bundles in white matter using diffusion tensor maps and apply the method to practical data. We can calculate diffusion tensor maps by combining several diffusion weighted images (DWI) that correspond to the mobility of water protons in 3D spaces. The intensity of DWI depends on the respective orientation of fiber bundles and the gradient direction at each different imaging slice. Specifically in white matter, we see a wide variation in diffusion. There are still qualitative analyses about DWI and few quantitative analyses about diffusion tensor maps. This report is essentially dedicated to make structural brain maps about white matter fiber bundles and suggest the usefulness for analyses of brain function.

Diffusion tensor imaging (DTI) has become a powerful tool for analyzing the structure of nerve bundles in white matter. However, there are still problems to investigate the connectivity of the nerve bundles. The main problem is to detect a junction. Solving such problems, we consider a scalar potential field using several characteristics of the diffusion tensor extracted from DTI. The characteristics include fractional anisotropy (FA) itself, the similarity of the principal axis of the diffusion tensor, and FA. This approach is different from a conventional tracking-detecting method as for considering not only the orientation of tissues but also the similarity of characteristics of the neighborhood. To make the scalar potential field, we multiply the magnitude of each characteristic. In such field, we could give the high potential value for the high possibility of nerve bundle existence. Then we propose the method to estimate the connectivity of the nerve bundles between any two points in the field. We also apply the method to clinical data. From the result, we obtain the line integral of the potential between two points on the field that will be treated as the communication pathway of the nerve bundles. The goal is to obtain the qualitative in vivo analysis of the connectivity of nerve bundles and this study is the first step.

Two functional brain-mapping techniques, functional magnetic resonance imaging (fMRI) and cortical stimulation by chronically implanted subdural electrodes, were used in combination for presurgical evaluation of three patients with intractable, partial motor seizures. Brain mapping was focused on characterizing motor-related areas in the medial frontal cortex, where all patients had organic lesions. Behavioral tasks for fMRI involved simple finger and foot movements in all patients and mental calculations in one of them. These tasks allowed us to discriminate several medial frontal motor areas: the presupplementary motor areas (pre-SMA), the somatotopically organized SMA proper, and the foot representation of the primary motor cortex. All patients subsequently underwent cortical stimulation through subdural electrodes placed onto the medial hemispheric wall. In each patient, the cortical stimulation map was mostly consistent with that patient's brain map by fMRI. By integrating different lines of information, the combined fMRI and cortical stimulation map will contribute not only to safe and effective surgery but also to further understanding of human functional neuroanatomy.

To evaluate the clinical significance of reverse redistribution (RR) of resting 201Tl single photon emission computed tomography (SPECT) in patients with vasospastic angina (VSA), we performed left ventriculography, coronary angiography and resting 201Tl-SPECT in 22 patients with VSA. Left ventriculography showed abnormal wall motion in 17 of 22 patients (77%) and 37 of 154 segments. Thirty-one of these 37 segments (84%) were within the area perfused by coronary arteries showing acetylcholine-induced vasospasm. On 201Tl images, abnormal findings were observed in 11 of 22 patients (50%), and among them, 7 patients (32%) had RR. Seven of 37 segments (19%) having abnormal regional wall motion had RR of 201TI, and in 6 of these 7 segments (86%), accumulation of 123I-BMIPP was found to be reduced. We conclude that repetitive brief myocardial ischemia may cause myocardial injuries in patients with VSA, and that the presence of RR of 201Tl indicates the presence of myocardial injury in these patients.

BACKGROUND AND PURPOSE: Chronic hypoperfusion may cause ischemic insult in the deep white matter. The magnetization transfer phenomenon is associated with the amount and constitution of myelin. The purpose of this study was to assess the usefulness of the magnetization transfer ratio (MTR) for detecting vasculometabolic abnormalities on positron emission tomography (PET) studies in patients with unilateral severe stenosis of the internal carotid artery (ICA). METHODS: MTR maps and PET data—including regional cerebral blood flow (rCBF), regional cerebral metabolic rate of oxygen (rCMRO(2)), and regional oxygen extraction fraction (rOEF)—were investigated in 13 patients with unilateral severe stenosis of the ICA. The same regions of interest were selected in the white matter both on MTR maps and PET scans. The areas were classified into three groups based on MTR values (group 0, MTR >47.22%; group 1, MTR = 45.77% to 47.22%; group 2, MTR

PET and SPECT using appropriate radioligands allow imaging of certain critical components of neurotransmission such as presynaptic transporters and postsynaptic receptors in living human brains. PET and SPECT data are commonly analyzed by applying tracer kinetic models. These modeling approaches assume a compartmental system and derive the outcome measure called the binding potential, which reflects the densities of transporters or receptors in a brain region of interest. New models are often noninvasive in that they do not require arterial blood sampling. In this review, the concept and principles of tracer kinetic modeling are introduced and commonly used PET and SPECT neuroreceptor quantification models are discussed.

A 68-year-old man was referred to our hospital after being treated for early gastric cancer to investigate the causative malignancy, as his serum carcinoembryonic antigen (CEA) level was increased. Chest radiography showed no abnormal opacities. Subsequently, a whole-body FDG-PET was performed, which detected some tiny lesions in the mediastinum and the right lower lung field. A diagnosis of small-cell lung carcinoma was made after mediastinoscopic and bronchoscopic examinations. After chemoradiotherapy, the previously abnormal uptake of FDG was attenuated and the bronchoscopic appearance was improved, while the serum CEA and NSE levels returned to normal. Our findings demonstrated that whole-body scanning by FDG-PET could be useful for early detection of lung cancer, especially in cases of small-cell lung cancer.

In recent years the use of positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (FDG) has become a valuable tool in the detection of a variety of tumors including lung cancer. To determine its role in the diagnosis of patients with suspected lung cancer, we compared the results of FDG-PET with those of the other scintigraphic imaging techniques (67Ga-planar image, 201Tl-SPECT and 99mTc-bone scintigraphy) used worldwide in patients with lung cancer. The analysis group consists of 178 patients, 159 malignant pulmonary diseases and 19 benign pulmonary diseases. FDG-PET was performed in 65 patients (51 malignant pulmonary diseases, 14 benign pulmonary diseases). FDG-PET had a sensitivity, specificity and accuracy of 98.0%, 78.6% and 93.8%, respectively, in detecting malignant pulmonary nodules. In N staging, sensitivity, specificity and accuracy were 66.7%, 81.3% and 76.0%, respectively. In M staging, the accuracy was 100%. Thus, FDG-PET imaging was more accurate than the other types of scintigraphic imaging. In our observations, whole-body 18FDG-PET images improved diagnostic accuracy in the evaluation of lung lesions and the staging of lung cancer.

Pediatric intussusception is usually idiopathic in origin, and a pathological lesion at the leadpoint is identified in only a small proportion of cases. Meckel's diverticulum is the most common location when such a lesion is found. Heterotopic pancreas has been seen most frequently in the stomach or duodenum; however, ileal lesions are rare. In the ileum, heterotopic pancreas is usually associated with Meckel's diverticulum and may cause intestinal obstruction by intussusception. However, isolated heterotopic pancreas in the ileum is distinctly rare and usually discovered incidentally during surgery for other conditions. In a review of English language literature, there were only a few pediatric cases of isolated ileal heterotopic pancreas causing intussusception. We report three additional pediatric cases and discuss the clinical significance of this unexpected rare entity.

The major neuropathological feature in Parkinson's disease (PD) is severe degeneration of the dopamine (DA) neurons in the substantia nigra. Dopamine transporter (DAT) is an important protein in the regulation of DA neurotransmission. It has been reported that PD patients show a loss of DAT in striatum. We report here the findings of single photon emission computed tomography (SPECT) of the DAT with 2 beta-carboxymethoxy-3 beta-(4[123I]iodophenyl)tropane ([123I] beta-CIT) to investigate striatal DAT in 10 patients with PD, one patient with vascular parkinsonism (VP), and one patient with dystonia syndrome. Patients were evaluated using the Webster rating scale. Specific/nondisplaceable striatal binding ratio (V3") was obtained in each case. In PD patients, the uptake of [123I] beta-CIT was reduced, especially in the tail of putamen compared with caudate nucleus. Even in the early stage of PD, the uptake of beta-CIT was reduced not only in the severely affected side, but also in the mildly disturbed side of the brain. Putamen caudate ratio was generally low in PD patients. In VP patient, the uptake was reduced, but putamen caudate ratio was not decreased. V3" values showed significant correlation with the severity of clinical symptoms such as self-care, facies, posture, gait, speech, and Hoehn-Yahr's stage. On the other hand, V3" values were not significantly correlated with the degree of tremor, seborrhea, and duration of the illness. In conclusion, we found that SPECT of the [123I] beta-CIT is a useful method for the diagnosis in the patients presenting parkinsonism, and for the clinico-physiological estimation of parkinsonian symptoms such as self-care, facies, posture, gait, and speech.

A Phase 2 multicenter trial of 123I-IBF, (S)-5-iodo-7-N-[(1-ethyl-2- pyrrolidinyl)methyl]carboxamido-2,3-dihydrobenzofuran, was conducted to evaluate its clinical efficacy and safety in 158 patients with Parkinson's disease (PD) or Parkinson syndromes (PS). SPECT data were acquired at two hours (2H-SPECT), after intravenous injection of 123I-IBF (167 MBq). Additional SPECT scan at three hours (3H-SPECT) and dynamic SPECT scan at most until one hour were performed when possible. No severe side effects due to 123I-IBF injection were observed. The sensitivity, specificity and accuracy for discriminating PS from PD using the striatal specific binding count-to-frontal cortex count ratio (St/Fc-1) in 3H-SPECT were 72.7%, 81.0% and 78.1% in 64 clinically definite cases (i.e., typical cases), respectively. The putamen-to-caudate ratios were significantly lower in striatonigral degeneration compared with those in PD. The contralateral-to-ipsilateral ratios against the symptomatic side of tremor and/or rigidity in the patients with PD (HoehnYahr I) were significantly higher than the left-to-right ratios in the normal controls. St/Fc-1 in 3H-SPECT was significantly lower in the patients showing a poor response to levodopa than in those showing a good response. The dopamine D2 receptor binding potential (k3/k4), obtained by dynamic SPECT based on compartment model analysis, correlated well with the striatal specific binding count-to-occipital cortex count ratio. These results suggest that 123I-IBF is a promising agent for differential diagnosis and pathophysiological evaluation of PD and PS.

The purpose of this study was to investigate the cortical motor areas activated in relation to unilateral complex hand movements of either hand, and the motor area related to motor skill learning. Regional cerebral blood flow (rCBF) was measured in eight right-handed healthy male volunteers using positron emission tomography during a two-ball-rotation task using the right hand, the same task using the left hand and two control tasks. In the two-ball-rotation tasks, subjects were required to rotate the same two iron balls either with the right or left hand. In the control task, they were required to hold two balls in each hand without movement. The primary motor area, premotor area and cerebellum were activated bilaterally with each unilateral hand movement. In contrast, the supplementary motor area proper was activated only by contralateral hand movements. In addition, we found a positive correlation between the rCBF to the premotor area and the degree of improvement in skill during motor task training. The results indicate that complex hand movements are organized bilaterally in the primary motor areas, premotor areas and cerebellum, that functional asymmetry in the motor cortices is not evident during complex finger movements, and that the premotor area may play an important role in motor skill learning.

Benzodiazepine receptor binding was assessed in four Japanese men with Machado-Joseph disease.The distribution of benzodiazepine receptors was measured by radionuclide imaging (SPECT) after intravenous administration of 123I-iomazenil (Ro 16-0154).SPECT demonstrated decreased binding throughout the cerebral cortex and cerebellum in all patients. Binding potential (receptor concentration x affinity) was diffusely decreased in cerebral cortex, thalamus, striatum and cerebellum compared with control subjects, suggesting that GABAergic function may be decreased globally in these patients. Cerebral blood flow was largely normal, and no cerebral cortical atrophy was evident on MRI.Iodine-123-iomazenil SPECT may become a potent method for detecting impairment of the cerebral cortex even before brain perfusion SPECT or MRI can reveal early abnormalities.

Regional resting cerebral blood flow and vascular reserve in a patient with transient global amnesia (TGA) were evaluated during and after a TGA episode using 99mTc-ethyl cysteinate dimer (ECD). The patient had consecutive SPECT studies before and after acetazolamide (ACZ) administration with adjunctive radionuclide angiography using equal-volume-split 99mTc-ECD. SPECT study during TGA episode showed poor vasodilatory reactivity to ACZ in the left medial temporal region involving the hippocampus and resting hypoperfusion in the regions bilaterally. The resting hypoperfusion with reserved vasodilatory reactivity to ACZ also was seen in the bilateral thalami. Abnormal findings in these regions disappeared on the follow-up SPECT study 15 days after the onset. No previous SPECT evaluation of regional abnormalities of both hemodynamic reserve and resting perfusion during and after an episode of TGA has been reported.

A noninvasive microsphere method using N-isopropyl-p-[123I]iodoamphetamine (123I-IMP), developed by Yonekura et al., was performed in 10 patients with neurological diseases to quantify regional cerebral blood flow (rCBF). Regional CBF values by this method were compared with rCBF values simultaneously estimated from both the modified fractional uptake (FU) method using cardiac output developed by Miyazaki et al. and the conventional method with continuous arterial blood sampling. In comparison, we designated the factor which converted raw SPECT voxel counts to rCBF values as a CBF factor. A highly significant correlation (r = 0.962, p0.001) was obtained in the CBF factors between the present method and the continuous arterial blood sampling method. The CBF factors by the present method were only 2.7% higher on the average than those by the continuous arterial blood sampling method. There were significant correlation (r = 0.811 and r = 0.798, p0.001) in the CBF factor between modified FU method (threshold for estimating total brain SPECT counts; 10% and 30% respectively) and the continuous arterial blood sampling method. However, the CBF factors of the modified FU method showed 31.4% and 62.3% higher on the average (threshold; 10% and 30% respectively) than those by the continuous arterial blood sampling method. In conclusion, this newly developed method for rCBF measurements was considered to be useful for routine clinical studies without any blood sampling.

Homologs of Saccharomyces cerevisiae STE3, a-factor receptor gene were detected from S. exiguus NFRI 3539 by low stringency Southern hybridization. This strain might have at least two types of homolog. One of these homologs, designated as e-STE3 was cloned. Its nucleotide sequence revealed 60% identity to STE3. The putative protein coding region consisted of 453 amino acid residues. The amino acid sequence identity between STE3 and e-STE3 was 62% and that of the N-terminal 303 amino acid residues considered to be the pheromone binding domain was 79%.

We describe the clinical features and results of cardiac catheterization, PET ([13N]ammonia, 18F-fluorodeoxyglucose (FDG)) and SPECT [123I-labeled 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP)], in a patient with acute myocardial infarction successfully treated with intracoronary thrombolytic therapy. We compared the clinical and electrocardiographic changes with the myocardial glucose and fatty acid metabolism in stunned myocardium over a period of several months. The patient we studied illustrates the features of stunned myocardium. In the subacute phase, there was a concordant depression of myocardial [13N]ammonia and FDG uptake, and the metabolic abnormalities persisted even after regional wall motion at rest had returned to normal. The electrocardiographic recovery of deep negative T waves appeared to be related to the metabolic recovery in regions of stunned myocardium in this patient.

We have developed a noninvasive method to quantify brain perfusion SPECT with 123I-N-isopropyl-p-iodoamphetamine (IMP) using serial dynamic planar imaging of the initial transit phase. The method is based on the microsphere model, but does not require arterial sampling. Serial dynamic planar imaging was performed for 6 min after the bolus injection of IMP (167 MBq in 1.5 ml), followed by additional planar imaging at 20 min and SPECT scan thereafter. The total arterial input to the brain during the initial 5 min after injection was estimated by the injected dose, with the correction of the lung retention, divided by cardiac output (CO). CO was estimated from the initial transit of IMP in the right heart. Cardiac output index (COI), obtained from the integral of the first transit of IMP in the right heart divided by the injected dose, was calibrated by CO measured by Doppler ultrasonography. Regional cerebral blood flow (rCBF) obtained by this method in normal subjects was acceptable. However, the results may be influenced by the injection technique, and careful attention should be considered for clinical application of this method.

We evaluated the regional distribution of 62Cu-pyruvaldehyde bis(N4-methylthiosemicarbazone) (62Cu-PTSM), a potential PET perfusion agent, in the rat brain and observed hyperfixation in transient global ischemia in rats.The distribution of 62Cu-PTSM was examined in comparison with that of 123I-labeled p-iodophenyl-N-isopropylmethanphetamine (123I-IMP) as a reference blood flow marker. Brain uptake of these two tracers was measured in Wistar rats subjected to 30-min four-vessel occlusion followed by recirculation for 10 min, 1 hr or 1, 3 or 5 days. Tracers were injected intravenously into rats 10 min before decapitation. The activities of Complex I and Complex I-III of mitochondria and the concentration of sulfhydryl (SH) groups were also measured.Copper-62-PTSM showed accelerated accumulation in the brain at 1 hr and 1 day after reperfusion when compared with that of 123I-IMP (p0.01), and this enhancement was considered to be due to hyperfixation. At these time points, SH concentration was significantly decreased (p0.01). On the other hand, the activity of Complex I was not influenced by ischemia/reperfusion, but that of Complex I-III was decreased to 65-70% of the control level (p0.01).Copper-62-PTSM showed hyperfixation most possibly as a result of increased NADH concentration, caused by disturbed electron transport in mitochondria.

An ideal hypoxia imaging agent should have high membrane permeability for easy access to intracellular mitochondria and low redox potential to confer stability in normal tissue, but it should be able to be reduced by mitochondria with abnormally high electron concentrations in hypoxic cells. In this context, nitroimidazole residues are not considered to be essential. In this study, Cu(II)-diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM), a 62Cu-bisthiosemicarbazone complex, with high membrane permeability and low redox potential, was evaluated as a possible hypoxia imaging agent, using electron spin resonance spectrometry and the Langendorff isolated perfused rat heart model as well as rat heart left anterior descending occlusion model.Nonradioactive Cu-ATSM was incubated with rat mitochondria, after which reduction of Cu(II) to Cu(I) was measured with electron spin resonance. As a model of hypoxic mitochondria, rotenone (Complex I inhibitor)-treated mitochondria were used.In this study, Cu-ATSM was reduced by hypoxic but not by normal mitochondria.Thus, retention of 62Cu-ATSM was studied serially in perfused rat hearts under conditions of normoxia (95% O2 + 5% CO2), hypoxia (95% N2 + 5% CO2) and reoxygenation (95% O2 + 5% CO2). In normoxia and reoxygenation, 62Cu-ATSM injected as a single bolus showed low retention (23.77% and 22.80%, respectively) 15 min after injection, but retention was increased markedly under hypoxic conditions (81.10%). Also, in the in vivo left anterior descending occluded rat heart model, 62Cu-ATSM retention was inversely correlated with accumulation of 201Tl, a relative myocardial blood flow marker.

The transient change in uptake of deoxyglucose (DG) and expression of glycolysis-associated gene products in cultured tumor cells (LS180 human colon adenocarcinoma cells) immediately after single-dose X irradiation were examined to acquire basic data for use in the early assessment of tumor responses to radiation treatment by position emission tomography. An increase in accumulation of DG was found 3-5 h postirradiation. Inhibitors of both mRNA and protein synthesis and glycoprotein transport suppressed the increase in accumulation of DG to the control level. Both the glucose transporter-1 mRNA expression and the enzymatic activity of hexokinase in the cells were significantly elevated in conjunction with high DG accumulation. These findings indicate that the transiently elevated glucose metabolism occurred via processes at the levels of gene expression. These transient tumor cell responses might be useful for the early assessment of radiation damage.

A one-day protocol with a double injection of 99mTc-ECD was introduced for the assessment of cerebral perfusion reserve with acetazolamide (ACZ). The purpose of this study was to investigate the feasibility and effectiveness of this protocol.Thirty subjects were given double injections of 99mTc-ECD (first dose 370 MBq; second dose 740 MBq) for consecutive brain perfusion studies. Serial dynamic SPECT scans (1 min x 50 frames) were performed with the first set of SPECT data obtained by totaling the data for the frames taken between 5 and 20 min, and the second by subtracting the decay and dose-corrected initial SPECT data from the sum of the data obtained between 35 and 50 min. To evaluate the feasibility and effectiveness of the procedure, 23 of the 30 subjects were injected with ACZ 14 min after the first dose. To evaluate the reproducibility, seven subjects were not given the ACZ. The washout rate (WR) was calculated for three stages (WR1 = from 6 to 14 min, WR2 = from 20 to 28 min, and WR3 = from 36 to 44 min). Regional count increase (percent increase) and the percent count difference between normal and affected side (percent difference) were also calculated.Values for WR1, WR2 and WR3 did not show significant differences among the stages (WR1 = -1.43% +/- 6.09%, WR2 = -0.65% +/- 6.57%, and WR3 = -1.60% +/- 4.28%; F-value = 0.33, p-value = 0.72). Reproducibility was excellent (second SPECT = 0.964 x first SPECT; r = 0.997). Mean count increase after ACZ was 21.7%. In patients with unilateral cerebrovascular disease, the percent increase after ACZ loading was significantly greater on the normal side (26.6% +/- 13.0%) than on the affected side (19.3% +/- 13.2%) (p0.01), resulting in a significant increase in percent difference (control: 14.3% +/- 10.7%, ACZ: 19.2% +/- 11.5%; p0.01).ECD washout was minimal during the first 50 min after injection and was not affected by ACZ, which supports the feasibility of this protocol. The simple procedure and short acquisition time of this method renders it clinically useful for measuring cerebral perfusion reserve.

Autonomic neuropathy along with cardiac denervation is one of the prognostic factors of diabetic patients. The aim of this study was to establish qualitative and quantitative assessment of diabetic cardiac denervation using [123I]metaiodobenzylguanidine (MIBG).The study population consisted of 31 diabetic patients and 12 control subjects (C). Diabetic patients were classified into the following three groups according to their presentation of neuropathy: NO, without neuropathy; N1, mild neuropathy; N2, severe neuropathy. All subjects underwent triple-phase MIBG scanning, including dynamic planar imaging as well as early and delayed planar and SPECT imaging. Myocardial uptake ratios of MIBG and heart-to-mediastinum count ratios (H/M) were calculated as global uptake indices. Inferior-to-anterior count ratios and coefficients of variation were calculated as regional distribution indices. The washout rate of the inferior wall and whole myocardium were also studied.MIBG abnormalities were obvious in the inferior wall, which gradually spread to the adjacent segments. All indices of regional uptake showed a significant difference (p0.01) among the groups, while only the H/M of the late image showed significant differences in the two global uptake indices (p = 0.02). the washout rate of the inferior wall was enhanced with neuropathy.Diabetic neuropathy involves an MIBG abnormality in its early stages. Since this abnormality occurs in the inferior segment, an inferior-to-anterior count ratio, an index of regional MIBG uptake could be suitable for the evaluation of this condition because of its superior sensitivity.

The kinetic behavior of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in the human brain was investigated in six normal volunteers.Dynamic SPECT and a three-compartmental model were used to estimate the rate constants of 99mTc-ECD in normal human brain. Extraction fraction (E), retention fraction (R) and permeability surface area product (PS product) of 99mTc-ECD were calculated using the rate constants. Regional cerebral blood flow (rCBF) was measured by PET with 15O-water.The rate constants in the cerebral cortex were estimated as 0.307 +/- 0.021 for K1 (influx constant), 0.201 +/- 0.047 for k2 (backdiffusion rate constant), 0.547 +/- 0.103 for k3 (lipophilic-to-hydrophilic conversion constant) and 0.0028 +/- 0.0012 for k5 (rate constant from lipophilic compartment to blood) at rCBF of 0.509 +/- 0.055 ml/g/min (mean +/- s.d.). The first-pass extraction, retention fraction and PS product were calculated as 0.608 +/- 0.069, 0.734 +/- 0.047 and 0.477 +/- 0.060, respectively. The first-pass extraction of 99mTc-ECD decreased significantly with increases in rCBF. The retention fraction and PS product of 99mTc-ECD did not show significant changes within the normal range of rCBF. The net extraction of 99mTc-ECD calculated from the static SPECT image obtained from 20 to 40 min was 0.358 +/- 0.039 in the cortex.Technetium-99m-ECD has a fairly high brain extraction, and its retention fraction and PS product appear to be independent of rCBF in the healthy human brain.

A child with Alagille syndrome, characterized by intrahepatic bile duct paucity, developed severe liver cirrhosis and was referred for liver transplantation. In the pre-transplantation evaluation, scintigraphic scans were performed using 99mTc-galactosyl serum albumin (99mTc-GSA) as a hepatoreceptor binding agent and 99mTc-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) as a hepatobiliary agent. These studies demonstrated severe hepatobiliary dysfunction with an area of increased focal uptake in the liver. Histological examination at surgery confirmed that this focal lesion was an area of compensatory hyperplasia in advanced biliary cirrhosis. We present the usefulness of these tracers for detecting the focal hyperplasia of the liver.

The tracer 123I-BMIPP was examined for its ability to reflect myocardial lipid metabolism. Studies in mice indicate that myocardial BMIPP uptake correlates with ATP content. Details, however, of myocardial accumulation in the ischemic period with either infarct or ischemia are not well documented.Sixteen adult mongrel dogs were investigated. The occluded left anterior descending artery (LAD) alone was reperfused to make the ischemic area, and the first diagonal branch of the LAD was kept occluded to make the infarct area. Regional wall motion was evaluated by echocardiography in the short-axial view from the epicardium. Tissue blood flow was calculated using nonradioactive colored microspheres. Changes in blood glucose levels, lipid levels and lactate extraction were examined in blood collected from the aorta and great cardiac vein (GCV). The ATP concentration and BMIPP count were determined by high-performance liquid chromatography and gamma-counter, respectively.Two hours after reperfusion, blood flow decreased to 20% +/- 5% in the infarct area and 64% +/- 9% in the ischemic area (p0.05), despite comparable wall-motion reduction (32% +/- 5% and 42% +/- 12% in the infarct and ischemic areas, respectively). BMIPP content and ATP concentration showed parallel reduction: 40% +/- 7% and 75% +/- 4% (p0.05) of BMIPP and 32% +/- 9% and 69% +/- 7% (p0.05) of ATP in the infarct and ischemic areas, respectively. The nonesterified fatty acid extraction, defined as flow x ([artery] - [GCV]), decreased to 87% +/- 5.6% during occlusion and 75% +/- 20.1% 2 hr after reperfusion, as compared with the control value.BMIPP uptake correlated well with lipid metabolism and tissue ATP levels and may prove useful in differentiating myocardial infarction from ischemia in the acute phase of ischemic episodes.

We evaluated quantitatively 62Cu-labeled pyruvaldehyde bis(N4-methylthiosemicarbazone) copper II (62Cu-PTSM) as a brain perfusion tracer for positron emission tomography (PET). For quantitative measurement, the octanol extraction method is needed to correct for arterial radioactivity in estimating the lipophilic input function, but the procedure is not practical for clinical studies. To measure regional cerebral blood flow (rCBF) by 62Cu-PTSM with simple arterial blood sampling, a standard curve of the octanol extraction ratio and a three-compartment model were applied.We performed both 15O-labeled water PET and 62 Cu-PTSM PET with dynamic data acquisition and arterial sampling in six subjects. Data obtained in 10 subjects studied previously were used for the standard octanol extraction curve. Arterial activity was measured and corrected to obtain the true input function using the standard curve.Graphical analysis (Gjedde-Patlak plot) with the data for each subject fitted by a straight regression line suggested that 62Cu-PTSM can be analyzed by the three-compartment model with negligible K4. Using this model, K1-K3 were estimated from curve fitting of the cerebral time-activity curve and the corrected input function. The fractional uptake of 62Cu-PTSM was corrected to rCBF with the individual extraction at steady state calculated from K1-K3. The influx rates (Ki) obtained from three-compartment model and graphical analyses were compared for the validation of the model. A comparison of rCBF values obtained from 62Cu-PTSM and 150-water studies demonstrated excellent correlation.The results suggest the potential feasibility of quantitation of cerebral perfusion with 62Cu-PTSM accompanied by dynamic PET and simple arterial sampling.

We developed copper-62-labeled human serum albumin-dithiosemicarbazone (62Cu-HSA-DTS) as a blood-pool imaging agent for PET. To evaluate 62Cu-HSA-DTS for plasma-pool imaging and to measure the regional cerebral hematocrit, 12 normal volunteers and 7 patients with cerebrovascular disease underwent PET studies with 62Cu-HSA-DTS and 15O-labeled carbon monoxide (C15O).The normal subjects were studied with both C15O and 62Cu-HSA-DTS. All patients were examined by 15O-gas studies to measure cerebral perfusion and oxygen metabolism, followed by measurement of plasma volume with 62Cu-HSA-DTS for analysis of regional cerebral hematocrit. Regional cerebral hematocrit was calculated from regional cerebral red cell volume (rCRCV) measured by C15O and regional plasma volume (rCPV) measured by 62Cu-HSA-DTS in each subject, and the regional cerebral/large-vessel hematocrit ratio was obtained for both cerebral hemispheres in each subject.Mean regional cerebral hematocrit and mean cerebral/large-vessel hematocrit ratio in the 12 normal volunteers were 38.3 +/- 3.45% and 0.88 +/- 0.06, respectively. In the seven patients with cerebrovascular disease, regional cerebral hematocrit was significantly lower on the hypoperfused side than the normal hemisphere. The images of rCPV and rCRCV from these patients demonstrated a greater increase in rCPV than rCRCV in the hypoperfused area.These results suggest that 62Cu-HSA-DTS can be used for measurement of plasma volume and that regional cerebral hematocrit may provide valuable information regarding the microcirculation in the brain.

The kinetics and metabolic fate of 123I-15-(p-iodophenyl)-3-(R,S)- methylpentadecanoic acid (BMIPP) in canine myocardium were studied in an open-chest dog model.After left anterior descending artery injection of BMIPP, blood samples were collected from the corresponding great coronary vein (V) and femoral artery (A). On the basis of the A-V radioactivity difference as well as the HPLC elution profile at various time points, myocardial extraction, retention and metabolism of BMIPP were evaluated.BMIPP was instantly extracted from the plasma into the myocardium (74% of the injected dose) and was then retained (65.3%). Washout of the retained radioactivity was low (8.7%) and most of the washout was as alpha- and beta-oxidation metabolites (2.3 + 2.9 + 1.4%), with little loss of BMIPP itself (2.1 %).BMIPP is suitable for static SPECT imaging of the myocardium, and its slow washout appears to be due to metabolism through alpha- and beta-oxidation.

We evaluated myocardial blood flow, glucose and oxygen metabolism using PET in hypertrophic cardiomyopathy (HCM).PET studies using 18F-fluorodeoxyglucose (FDG) and 11C-acetate were performed at rest in patients with HCM and normal subjects as a control group. The metabolic rate of glucose (MRGlu), K mono value as a marker of oxidative metabolism, and myocardial blood flow were estimated from serial dynamic FDG and 11C-acetate PET studies.Myocardial blood flow (%) did not differ significantly in hypertrophic and nonhypertrophic myocardium (90.3 +/- 3.1 versus 91.7 +/- 3.4). The MRGlu in hypertrophic myocardium, however, was lower than that of hypertrophic and normal myocardium (0.44 +/- 0.10 versus 0.52 +/- 0.15 and 0.53 +/- 0.15 mumole/min/g, respectively, p0.05). The K mono values were also lower in hypertrophic myocardium than in nonhypertrophic and normal myocardium (0.05 +/- 0.010 versus 0.066 +/- 0.0011 and 0.065 +/- 0.017 per min, respectively, p0.05). The %FDG/%perfusion values in hypertrophic myocardium did not differ significantly from those in nonhypertrophic myocardium (0.96 +/- 0.10 versus 1.02 +/- 0.07).Myocardial ischemia at rest is observed less frequently in patients with HCM. Impairment of oxidative and glucose metabolism may precede decreased blood flow. Primary metabolic impairment is considered to be dominant in hypertrophic myocardium.

Iomazenil (IMZ) is a partial inverse agonist of central-type benzodiazepine receptors (BZR) which binds specifically to BZR with high affinity. The safety and clinical effectiveness of 123I-IMZ SPECT in the diagnosis of brain diseases were evaluated in 655 patients with various brain diseases, such as epilepsy, cerebrovascular diseases, degenerative diseases and mental disorders relating to BZR. This was a Phase 3 study conducted as a multicenter trial at 52 collaborating institutions. There was no significant adverse reactions in the clinical symptoms or abnormal laboratory test values. The investigators judged 123I-IMZ SPECT to be effective in 95% of 638 analyzed cases. The injected dose did not correlate with the image quality or the clinical effectiveness of 123I-IMZ SPECT, suggesting that these items depend largely on the characteristics of the apparatus used, the disease or pathology of the patients, rather than the dose. We conclude that 123I-IMZ imaging is safe and provides effective information based on BZR binding which is useful in the diagnosis of various brain diseases.

A Phase 3 clinical trial of 123I-Iomazenil (IMZ), a tracer which binds specifically to central-type benzodiazepine receptors (BZR), was performed, and the clinical usefulness of IMZ was evaluated in 121 patients with epilepsy (106 cases with partial epilepsy and 15 cases with generalized epilepsy). A regional abnormality in the BZR distribution was detected in late IMZ images in 20 of 24 cases without abnormal MRI and/or X-ray CT findings. Moreover, only 16 of these 20 cases showed abnormal findings in the cerebral blood flow (CBF) images. In partial epilepsy, abnormal regions in late IMZ images agreed or partially agreed with epileptic foci estimated from the clinical symptoms of epileptic seizures, interictal EEG, and MRI and/or X-ray CT findings in 76%, 70% and 96% of the cases detected. These regions also agreed or partially agreed with the estimated epileptic foci in 92% of the cases with foci estimated by combination of those three methods and in 72% of those estimated by ictal EEG. The agreement or partial agreement rates of late IMZ images with each of the other methods were higher than those of CBF images, although the differences were not significant. For surgically-proven epileptic foci without any abnormality in the CBF image, abnormal regions were detected in late IMZ images. These findings suggest that IMZ SPECT is a useful new tool for detecting epileptic foci based on the distribution of BZR in the brain.