利用4-[18F]-ADAM 在CT / PET立體影像量測血清素轉運體變化並搭配漢式憂鬱量表做重度憂鬱症的關聯分析

Reversal Learning as a Neuropsychological Indicator for the Neuropathology of Obsessive Compulsive Disorder? A Behavioral Study

Habib Zaidi, PhD This is an exciting time for molecular imaging because molecular medicine is expected to lead to a revolutionary paradigm shift in health care. While the nuclear medicine community is witnessing a revolution in the practice of this specialty with the introduction of dual-modality positron emission tomography (PET) and computed tomography (CT), many groups in academic and corporate settings are focusing their efforts on the development of promising multimodality imaging technologies that will combine magnetic resonance (MR) imaging and PET components in a single gantry. One such preclinical system is described by Judenhofer et al (1) in this issue of Radiology, and different design trends have been reported in the literature (2–8). Similar design concepts are also being investigated for combined single photon emission CT (SPECT) and MR imaging instrumentation (9). The recent interest in simultaneous PET/MR imaging is not the consequence of controversies surrounding the role and clinical benefits of PET/CT (10,11) but will likely be the subject of similar critique and debates. The development of PET/MR imaging has been motivated by various factors and has several important incentives (12). First, MR imaging is used to obtain anatomic and structural images with submillimeter spatial resolution that offers better soft-tissue contrast sensitivity than that offered by CT. MR imaging has excellent contrast between white and gray matter and allows for functional imaging in brain studies, and, more importantly, it can be used to assess flow, diffusion, perfusion, and cardiac motion in one examination (13). In addition, MR imaging can be combined with MR spectroscopy to measure the regional biochemical content and to assess the metabolic status or the presence of neoplasia and other diseases in specific tissue areas. Finally, MR imaging does not involve the use of ionizing radiation; thus, it can be used without restrictions in serial studies, for pediatric studies, and in many other situations where radiation exposure is a concern. PET imaging is used to record the regional distribution of radiolabeled tracers; however, unlike MR spectroscopy, it cannot be used to distinguish the specific molecular species to which the radionuclide is attached, and, unlike MR imaging, it provides little anatomic information. While many technical problems have recently been solved, there are still several important challenges to the implementation and operation of a PET/MR imaging system that must be overcome. In comparison with x-ray CT, MR imaging typically is more costly, involves longer examination times, and produces anatomic images from which it is more difficult or at least not as straightforward to derive attenuation maps for photon correction of the emission data (14). The latter issue was not described by Judenhofer et al (1), as it has received only limited attention in the scientific literature and few investigators have addressed the problem of the use of segmented MR data to construct an attenuation map for attenuation correction purposes with PET (15). However, interest in PET/MR imaging has been the driving force behind many worthwhile research efforts recently undertaken by different research groups. The major difficulty lies in the fact that the MR signal or tissue intensity level is not directly related to electronic attenuation, which renders conversion of MR images to attenuation maps less obvious when compared with CT. It is worth emphasizing that the optimal transmission scanning technique for PET/CT (ie, CT versus radionuclide sources) is still an open issue that remains to be addressed (16). This is not an issue for PET/MR imaging because of the limited space available, and thus, placement of external Published online 10.1148/radiol.2443070092

Over the past decade, functional neuroimaging has contributed greatly to our knowledge about the neuropharmacology of substance misuse in man. In this review, discussed the application and the progress of the positron emission tomography, single photon emission computed tomography and functional magnetic resonance imaging in the substance misuse. After reading some papers, found that the dopamine transporter was significantly decreased in the brain of subjects with heroin abuse. Also observed a significant decrease of regional cerebral blood flow in bilateral cerebral frontal lobes, temporal lobes, the insula and the ipsilateral basal nuclei in substance misuse subjects. Taken together, functional images will lead the direction in future research formedication development of addiction treatment. Key words: Substance related disorders; Radionuclide imaging; Tomography emission computed

Functional imaging plays an important role in lung cancer radiotherapy. Functional imaging techniques include single photon emission computed tomography, positron emission tomography, magnetic resonance imaging, and computed tomography. Using lung function information provided by these techniques for lung cancer radiotherapy can better protect the normal function of lung tissue, optimize the radiotherapy program, and reduce the incidence of radiation pneumonitis. With the development of perfusion and imaging technology, functional imaging technology is expected to be widely used in the precise radiotherapy of lung cancer in the future. Key words: Lung neoplasms; Radiotherapy; Functional lung imaging

To study patients with crossed aphasia (aphasia secondary to lesions in the right hemisphere in right-handed patients) with functional brain imaging using positron emission tomography (PET) or single photon emission computed tomography (SPECT); to see whether left hemisphere structures were metabolically depressed during the acute phase and, in 1 patient, during recovery; and to review the modern literature on crossed aphasia, with special reference to left hemisphere involvement. Case studies of 3 patients with crossed aphasia, including language testing, computed tomographic scanning, and functional imaging with PET or SPECT. Hospital case studies. Three right-handed patients with crossed aphasia secondary to acute infarctions in the right hemisphere and left hemiparesis. All 3 patients were studied by means of bedside language testing, computed tomographic scanning, and functional brain imaging with PET or SPECT. Patient 1 also underwent serial testing with the Boston Diagnostic Aphasia Examination and follow-up PET scanning after 2 months of recovery. Clinical examination in all 3 patients and follow-up Boston Diagnostic Aphasia Examination and PET scanning in patient 1. Two patients had severe global aphasia and 1 had Broca aphasia. In all cases, computed tomographic scans failed to reveal any left hemispheric lesions. Functional imaging with PET or SPECT showed extensive hypometabolism or hypoperfusion in the right hemisphere, with initial reductions in the left hemisphere as well. In patient I, a follow-up PET image showed only persistent hypometabolism in the right hemisphere. These findings suggest that abnormal dominance for at least some language functions in the right hemisphere underlies the syndrome of crossed aphasia. Diaschisis, or functional depression of the anatomically normal left hemisphere, was seen in all 3 patients during the acute phase, but not in patient 1 after recovery had begun.

Electrical brain imaging (EBI) refers to a set of techniques that exploit either the spontaneous electrical activity of the central nervous system, as in electroencephalographic (EEG) source reconstruction, or make use of external current injections, as in electrical impedance tomography (EIT) , to image the structure or function of the brain. When compared to other brain imaging methods used in research or in the clinical setting, such as computed tomography (CT), magnetic resonance imaging (MRI), functional MRI (fMRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT), EIT and EEG source localization instrumentation offer the advantages of portability, low cost, high temporal resolution [ms] and quick setup. The downsides are a low spatial resolution [cm], high computational cost of the image reconstruction process and high sensitivity to imperfections of the electrical model of the head.
\nIn this work, a new special purpose reconstruction algorithm for EIT is presented and validated wth experimental measurements performed on a cylindrical phantom and on a simulated human head. The algorithm focuses on the quick detection of compact conductivity contrasts in imperfectly known in 3D domains. The performance of the proposed algorithm is then compared to the one of a benchmark reconstruction method in the EIT field, Tikhonov regularized reconstruction, with stroke detection and classification as a case study. Moreover, the possible application of EIT imaging to the detection of epileptic foci with intracranial deep electrodes (stereoelectroencephalography or SEEG) is explored.
\nFinally, EEG source reconstruction algorithms are implemented on a heterogeneous multi-CPU and multi-GPU computing system to significantly reduce the reconstruction time.

Small-animal positron emission tomography as a tool for neuropharmacology

Investigating the effects of noise-induced hearing loss on serotonin transporters in rat brain using 4-[18F]-ADAM/small animal PET

Imaging serotonin transporters using [ 123I]ADAM SPECT in a parkinsonian primate model

Iofetamine hydrochloride I 123 permits cerebral blood perfusion imaging with single photon emission computed tomography (SPECT). SPECT is more widely available than positron emission tomography, and complements anatomic visualization with X-ray computed tomography (CT) or magnetic resonance imaging. Iofetamine is an amphetamine analog that is rapidly taken up by the lungs, then redistributed principally to the liver and brain. The precise mechanism of localization has not been determined, but is believed to result from nonspecific receptor binding. Brain uptake peaks at 30 minutes postinjection and remains relatively constant through 60 minutes. The drug is metabolized and excreted in the urine, with negligible activity remaining at 48 hours. When compared with CT in stroke patients, visualization may be performed sooner after symptom onset and a larger zone of involvement may be evident with iofetamine. Localization of seizure foci and diagnosis of Alzheimer's disease may also be possible. As CT has revolutionized noninvasive imaging of brain anatomy, SPECT with iofetamine permits routine cerebral blood flow imaging.

The purpose was to assess the clinical utility of diagnostic tests for identifying malignancy within a solitary pulmonary nodule (SPN), and to create a nomogram or "look-up" table using clinical data and non-invasive radiology (positive) test results to estimate post-test probability of malignancy. Studies that examined computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT) for the evaluation of SPN. Two reviewers independently abstracted data and assessed study quality. Study-specific and overall positive likelihood ratios (LRs) for each diagnostic test confirming a diagnosis of malignancy and negative LR for each diagnostic test excluding a diagnosis of malignancy within an SPN were calculated. Forty-four of 242 articles were included. Positive LRs for diagnostic tests were: CT 3.91 (95% confidence interval 2.42, 5.40), MRI 4.57 (3.03, 6.1), PET 5.44 (3.56, 7.32) and SPECT 5.16 (4.03, 6.30). Negative LRs were: CT 0.10 (0.03, 0.16), MRI 0.08 (0.03, 0.12), PET 0.06 (0.02, 0.09) and SPECT 0.06 (0.04, 0.08). Differences in performance for all tests were negligible; therefore, the clinician may confidently use any of the four tests presented in further evaluating an SPN. Given the low cost and prevalence of the technology, SPECT appears to be the leading choice for additional testing in SPN evaluation.

PET and SPECT in epilepsy: A critical review

Imaging of molecular signatures of specific structures, functions,and pathological alterations in the lung tissue represents animportant and challenging goal. This summary outlines generalthemes of the 24th annual Transatlantic Airway Conferencethat took place in Lucerne in January 2009 focused on thissubject. The following papers presented by the speakers outlinespecific subjects discussed at the meeting, including identifica-tion of candidate molecular signatures, design of imagingprobes, and application of specific imaging modalities forvisualization of pulmonary molecular signatures.Noninvasive, real-time visualizationof specific signs (markers)of physiologic and pathologic processes in the chest immenselyenhances our ability to study, diagnose, and treat lung diseases.Pulmonary imaging, first established using Roentgen’s X-rays,has diversified over the course of the last century to include anarsenal of imaging modalities such as X-ray computed tomog-raphy (CT), nuclear medicine positron emission tomography(PET) and single photon emission computed tomography(SPECT), optical imaging, and magnetic resonance imaging(MRI). One can now visualize structural information about thechest and lungs in addition to functional and molecular changesof diverse parameters. These include perfusion, ventilation,metabolism, tissue density, cell surface expression markers, andenzyme activity. Undoubtedly, the visual information providedat the structural, functional, and molecular levels by thesemodalities provides invaluable tools for evaluating the statusof normal and diseased lungs in both experimental and clinicalsettings.The extraordinary achievements in pulmonary imaging onlyreinforce the need for a discussion on the visualization of targetmolecular signatures in the lungs. ‘‘Target molecular signa-tures’’ are molecules that may serve as specific markers ofselected elements of tissue structures, and of physiologic orpathologic processes. Figure 1 provides selected examples ofsuch structures (cells and their compartments, components ofextracellular milieu, blood components), functions (cell pertur-bations, enzymatic activity, ventilation, and perfusion), andabnormalities (metabolic changes, neo-antigens and neo-epitopes,activation and translocation of nuclear factors, and nucleic acidchanges).The imaging of molecular signatures will enhance the pre-cision of differential diagnoses of pathologies that are otherwiseindistinguishable by current diagnostic tests, and improveprognoses by stratifying the disease stage and the responsive-ness to treatment. With imaging technologies we can ultimatelyimprove the management of lung diseases and usher in a newtype of ‘‘individualized medicine.’’ Imaging molecular signa-tures in small animal models assists in studying the mecha-nisms of pulmonary physiology and pathology. Furthermore,small animal imaging can guide the translational aspects of basicbench research by validating new therapeutics, diagnostics, oranimal models of human disease. It is thus appropriate andtimely that the organizers of the conference defined its topicas ‘‘Imaging Pulmonary Pathology and Target Molecular Signa-tures.’’Identification and visualization of target molecular signa-tures requires efforts in diverse biomedical areas using numer-ous strategies (Figure 2). This subject transcends boundaries ofmany disciplines in biomedical, engineering, chemical, bio-engineering, computer, and physical sciences. The conferencebrought together experts from many of these areas, bothclinicians and basic researchers, to educate each other, redefinethe current status of the subject, and establish new interdisci-plinary collaborations. The meeting focused on three topics:(1) identification of the pulmonary target molecular signatures,(2) design of imaging probes and their delivery to the targets,and (3) imaging modalities for visualization of pulmonarytarget molecular signatures. However, for the sake of focus(or ‘‘in the interest of time’’), some aspects of the challenges ofthe field (i.e., probe design, chemistry of isotope/emitterintroduction onto probe, development of instrumentation forimaging, and image analysis) were rather tangentially discussedat the meeting.IDENTIFICATION OF MOLECULAR SIGNATURES ANDEXPERIMENTAL APPROACHES FOR THEIR IMAGINGIn his introductory lecture, Dr. Piwnica-Worms provided anoverview of optical and radioisotope imaging of molecules andtheir interactions in living cells and laboratory animals, andgave examples of their applications in the pulmonary imaging(see article by Dothager and Piwnica-Worms, pages 403–410,this issue). Many speakers throughout the conference providedparticular examples of prospective pulmonary target molecularsignatures. Both intracellular (e.g., nucleic acids, enzymes, andtheir substrates) and extracellular (e.g., components of thecellular milieu as well as membrane proteins, sugars, andphospholipids) molecules may serve as molecular targets andsignatures for imaging (1, 2). Drugs, drug carriers, and othernanometer- and micron-scale objects (e.g., environmental pol-lutants and particles) delivered to the lungs via airway orvascular routes, and the physiologic effects caused by theseinterventions, also represent important targets for visualization(3–5) (see also articles by Dolovich, pages 477–485, and Zhangand colleagues, pages 450–457, this issue).Specific probes recognizing molecular targets or their specificmicroenvironment include nucleic acids, peptides, enzyme sub-strates, aptamers, sugars, metabolic probes, and a variety ofaffinity ligands including antibodies and their fragments. Probescan be labeled with specific agents that permit optical (lumi-nescence, fluorescence, or near infrared), nuclear medicine(SPECT or PET isotopes), or MRI (e.g., gadolinium) imaging(foroverviews, see articles by Ntziachristos,pages 416–418,Divgi,pages 464–468, Blankenberg, pages 469–476, and Kauczor andcolleagues, pages 458–463, this issue). In an optimal scenario,these probes are activated locally as a result of interaction withthe target or accessory molecules. Specific protease cleavage of

Brain imaging ismost often carried outwithX-ray computed tomography (CT) or magnetic resonance imaging (MRI). CT is fast, widely available, andhasmade conventional nuclearmedicine 99mTc pertechnetate brain imaging obsolete. MRI has the advantages of lack of ionizing radiation and superior soft tissue resolution. However, in an expanding number of clinical situations, brain single photon emission computed tomography (SPECT) or occasionally positron emission tomography (PET) may be the investigation of choice or provide complementary information to structural imaging. Virtually all nuclear medicine applications in the brain involve SPECT and there is rarely a role for planar imaging. It is important to understand the strengths and limitations of brain imaging in nuclear medicine so that these techniques are used appropriately alongside other methods of brain imaging. Newmethods of imaging neurotransmitter receptors and transporters have been developed and offer expanded roles for brainSPECT.Nuclearmedicine canmakevaluable contributions to the diagnosis and follow-up of patients with dementia, cerebrovascular disease, movement disorders, brain tumors, and other neurological diseases. This chapter will be divided into sections covering normal anatomy and physiology, technical aspects of brain SPECT, clinical applications of regional cerebral blood flow SPECT (rCBF SPECT), dopamine transporter and receptor imaging in movement disorders, and applications in brain tumor imaging. Where appropriate, the role of positron emission tomography (PET) will be indicated in the relevant sections. The only nuclear medicine application in the spine is bone scintigraphy, which is dealt with in Chapter 8.

Building on decades of technological advances and imaging experience, during which noninvasive imaging of cardiac structure and function, myocardial perfusion and viability, and noncoronary vascular pathology have become intimately entwined in routine clinical practice, advanced imaging techniques are now poised to deliver noninvasive coronary arteriograms and to delineate the coronary artery wall in exquisite detail. At the same time that these highly promising methods for anatomic imaging at the macroscopic level are creating great excitement among physicians, their patients, and the public, a quieter imaging revolution is underway with steady progress in detecting and tracking fundamental biological processes at the cellular and subcellular levels. In the era of genomic research, molecular biology, and stem cell therapies, these methods have great potential to accelerate understanding of basic pathophysiological processes in animals and humans and to develop new tools for early diagnosis and drug development. Cardiovascular molecular imaging is taking hold. See p 1800 Molecular imaging is the science of visually representing, characterizing, and quantifying cellular/subcellular biological processes in intact organisms. These processes include gene expression, protein–protein interaction, signal transduction, cellular metabolism, and both intracellular and intercellular trafficking. Molecular imaging has the potential to quantify these events, to monitor multiple events simultaneously, to localize these events in 3 dimensions, and to monitor these events serially. Thus, biological processes can be identified and studied in time and space, providing “4-dimensional” information. The emergence of molecular imaging has coincided with and has been made possible by the enormous progress in molecular biology, cell biology, and transgenic animal models, as well as the development of imaging probes that are specific, reproducible, and quantifiable.1 Molecular imaging was once the sole domain of nuclear medicine, with tracers developed for both positron emission tomography (PET) and single photon emission computed tomography (SPECT). Examples include antimyosin antibodies for …