A multicentre simulation study of planar whole-body bone scintigraphy in Sweden.

Background: Whole-body bone scintigraphy is a clinically useful non-invasive and highly sensitive imaging method enabling detection of metabolic changes at an early stage of disease, often earlier than with conventional radiologic procedures. Bone scintigraphy is one of the most common nuclear medicine methods used worldwide. Therefore, it is important that the examination is implemented and performed in an optimal manner giving the patient added value in the subsequent care process.

Cyclotron-produced Ga from enriched Zn foils.

The growing need and limited availability of generator produced Ga (T = 68 min) for PET has provided the impetus for alternative, high output, Ga production routes such as charge particle activation of enriched Zn using PET cyclotrons. The work presents a rapid production method for clinically useful Ga for radiolabeling. The focus is also to expand the production capacity of cyclotron solid target-produced Ga over generator produced and liquid solutions targets by using enriched Zn-foils that minimizes target preparation.

Diagnostic performance of the specific uptake size index for semi-quantitative analysis of I-123-FP-CIT SPECT: harmonized multi-center research setting versus typical clinical single-camera setting.

Introduction: The specific uptake size index (SUSI) of striatal FP-CIT uptake is independent of spatial resolution in the SPECT image, in contrast to the specific binding ratio (SBR). This suggests that the SUSI is particularly appropriate for multi-site/multi-camera settings in which camera-specific effects increase inter-subject variability of spatial resolution. However, the SUSI is sensitive to inter-subject variability of striatum size.

Head-to-Head Comparison among Semi-Quantification Tools of Brain FDG-PET to Aid the Diagnosis of Prodromal Alzheimer's Disease.

Background: Several automatic tools have been implemented for semi-quantitative assessment of brain [18]F-FDG-PET.

Objective: We aimed to head-to-head compare the diagnostic performance among three statistical parametric mapping (SPM)-based approaches, another voxel-based tool (i.e.

Brain Glucose Metabolism Heterogeneity in Idiopathic REM Sleep Behavior Disorder and in Parkinson's Disease.

Background/objective: Idiopathic REM sleep behavior disorder (iRBD) often precedes Parkinson's disease (PD) and other alpha-synucleinopathies. The aim of the study is to investigate brain glucose metabolism of patients with RBD and PD by means of a multidimensional scaling approach, using18F-FDG-PET as a biomarker of synaptic function.

Methods: Thirty-six iRBD patients (64.

Accuracy and generalization capability of an automatic method for the detection of typical brain hypometabolism in prodromal Alzheimer disease.

Purpose: The aim of this study was to verify the reliability and generalizability of an automatic tool for the detection of Alzheimer-related hypometabolic pattern based on a Support-Vector-Machine (SVM) model analyzing F-fluorodeoxyglucose (FDG) PET data.

Methods: The SVM model processed metabolic data from anatomical volumes of interest also considering interhemispheric asymmetries. It was trained on a homogeneous dataset from a memory clinic center and tested on an independent multicentric dataset drawn from the Alzheimer's Disease Neuroimaging Initiative.

The Alzheimer's disease metabolic brain pattern in mild cognitive impairment.

We investigated the expression of the Alzheimer's disease-related metabolic brain pattern (ADRP) in F-FDG-PET scans of 44 controls, 27 patients with mild cognitive impairment (MCI) who did not convert to Alzheimer's disease (AD) after five or more years of clinical follow-up, 95 MCI patients who did develop AD dementia on clinical follow-up, and 55 patients with mild-to-moderate AD. The ADRP showed good sensitivity (84%) and specificity (86%) for MCI-converters when compared to controls, but limited specificity when compared to MCI non-converters (66%). Assessment of F-FDG-PET scans on a case-by-case basis using the ADRP may be useful for quantifying disease progression.

Emerging clinical issues and multivariate analyses in PET investigations.

PET using 18F-2-fluoro-2-deoxy-D-glucose (FDG-PET) has been gradually introduced in the diagnostic clinical criteria of the most prevalent neurodegenerative diseases. Moreover, an increasing amount of literature has shown that the information provided by FDG-PET enhances the sensitivity of standard imaging biomarkers in less frequent disorders in which an early differential diagnosis can be of paramount relevance for patient management and outcome. Therefore emerging uses of FDG-PET may be important in prion diseases, autoimmune encephalitis (AE) and amyotrophic lateral sclerosis.

Early identification of MCI converting to AD: a FDG PET study.

Purpose: Mild cognitive impairment (MCI) is a transitional pathological stage between normal ageing (NA) and Alzheimer's disease (AD). Although subjects with MCI show a decline at different rates, some individuals remain stable or even show an improvement in their cognitive level after some years. We assessed the accuracy of FDG PET in discriminating MCI patients who converted to AD from those who did not.

Progressive Disintegration of Brain Networking from Normal Aging to Alzheimer Disease: Analysis of Independent Components of F-FDG PET Data.

Brain connectivity has been assessed in several neurodegenerative disorders investigating the mutual correlations between predetermined regions or nodes. Selective breakdown of brain networks during progression from normal aging to Alzheimer disease dementia (AD) has also been observed. We implemented independent-component analysis of F-FDG PET data in 5 groups of subjects with cognitive states ranging from normal aging to AD-including mild cognitive impairment (MCI) not converting or converting to AD-to disclose the spatial distribution of the independent components in each cognitive state and their accuracy in discriminating the groups.

Can Spatiotemporal Fluoride (F) Uptake be Used to Assess Bone Formation in the Tibia? A Longitudinal Study Using PET/CT.

Background: When a bone is broken for any reason, it is important for the orthopaedic surgeon to know how bone healing is progressing. There has been resurgence in the use of the fluoride (F) ion to evaluate various bone conditions. This has been made possible by availability of positron emission tomography (PET)/CT hybrid scanners together with cyclotrons.

[I]FP-CIT ENC-DAT normal database: the impact of the reconstruction and quantification methods.

Background: [I]FP-CIT is a well-established radiotracer for the diagnosis of dopaminergic degenerative disorders. The European Normal Control Database of DaTSCAN (ENC-DAT) of healthy controls has provided age and gender-specific reference values for the [I]FP-CIT specific binding ratio (SBR) under optimised protocols for image acquisition and processing. Simpler reconstruction methods, however, are in use in many hospitals, often without implementation of attenuation and scatter corrections.

Evaluation of inter-departmental variability of ejection fraction and cardiac volumes in myocardial perfusion scintigraphy using simulated data.

Background: Myocardial perfusion scintigraphy (MPS) is a clinically useful noninvasive imaging modality for diagnosing patients with suspected coronary artery disease. By utilizing gated MPS, the end diastolic volume (EDV) and end systolic volume (ESV) can be measured and the ejection fraction (EF) calculated, which gives incremental prognostic value compared with assessment of perfusion only. The aim of this study was to evaluate the inter-departmental variability of EF, ESV, and EDV during gated MPS in Sweden.

Neurobiology of Sleep Disturbances in PTSD Patients and Traumatized Controls: MRI and SPECT Findings.

Objective: Sleep disturbances such as insomnia and nightmares are core components of post-traumatic stress disorder (PTSD), yet their neurobiological relationship is still largely unknown. We investigated brain alterations related to sleep disturbances in PTSD patients and controls by using both structural and functional neuroimaging techniques.

Method: Thirty-nine subjects either developing (n = 21) or not developing (n = 18) PTSD underwent magnetic resonance imaging and a symptom-provocation protocol followed by the injection of 99mTc-hexamethylpropyleneamineoxime.

Using PET/CT Bone Scan Dynamic Data to Evaluate Tibia Remodeling When a Taylor Spatial Frame Is Used: Short and Longer Term Differences.

Eighteen consecutive patients, treated with a Taylor Spatial Frame for complex tibia conditions, gave their informed consent to undergo Na(18)F(-) PET/CT bone scans. We present a Patlak-like analysis utilizing an approximated blood time-activity curve eliminating the need for blood aliquots. Additionally, standardized uptake values (SUV) derived from dynamic acquisitions were compared to this Patlak-like approach.

Reduced acquisition times in whole body bone scintigraphy using a noise-reducing Pixon®-algorithm-a qualitative evaluation study.

Background: Reducing scan-time while maintaining sufficient image quality is a common issue in nuclear medicine diagnostics. This matter can be addressed by different post-processing methods such as Pixon® image processing. The aim of the present study was to evaluate if a commercially available noise-reducing Pixon-algorithm applied on whole body bone scintigraphy acquired with half the standard scan-time could provide the same clinical information as full scan-time non-processed images.

Effects on the FDG distribution by a high uptake of brown adipose tissue at PET examination.

Background: At fluorodeoxyglucose/positron emission tomography (FDG/PET) examinations, a generally increased uptake of the skeletal muscles is sometimes encountered. As the tracer distribution constitutes a 'zero-sum-game', the uptake of lesions as well as of normal tissues is reduced in these patients. This has to be considered at calculation of standardised uptake values (SUVs), especially at longitudinal examinations in the same patient.

The accuracy of quantitative parameters in (99m) Tc-MAG3 dynamic renography: a national audit based on virtual image data.

Assessment of image analysis methods and computer software used in (99m) Tc-MAG3 dynamic renography is important to ensure reliable study results and ultimately the best possible care for patients. In this work, we present a national multicentre study of the quantification accuracy in (99m) Tc-MAG3 renography, utilizing virtual dynamic scintigraphic data obtained by Monte Carlo-simulated scintillation camera imaging of digital phantoms with time-varying activity distributions. Three digital phantom studies were distributed to the participating departments, and quantitative evaluation was performed with standard clinical software according to local routines.

Towards mapping the brain connectome in depression: functional connectivity by perfusion SPECT.

Several studies have demonstrated altered brain functional connectivity in the resting state in depression. However, no study has investigated interregional networking in patients with persistent depressive disorder (PDD). The aim of this study was to assess differences in brain perfusion distribution and connectivity between large groups of patients and healthy controls.

(18)F-MCL-524, an (18)F-Labeled Dopamine D2 and D3 Receptor Agonist Sensitive to Dopamine: A Preliminary PET Study.

Unlabelled: PET has been used to examine changes in neurotransmitter concentrations in the living brain. Pioneering PET studies on the dopamine system have used D2 and D3 receptor (D2/D3) antagonists such as (11)C-raclopride. However, more recently developed agonist radioligands have shown enhanced sensitivity to endogenous dopamine.

Can Na18F PET/CT be used to study bone remodeling in the tibia when patients are being treated with a Taylor Spatial Frame?

Monitoring and quantifying bone remodeling are of interest, for example, in correction osteotomies, delayed fracture healing pseudarthrosis, bone lengthening, and other instances. Seven patients who had operations to attach an Ilizarov-derived Taylor Spatial Frame to the tibia gave informed consent. Each patient was examined by Na(18)F PET/CT twice, at approximately six weeks and three months after the operation.

Technical requirements for Na¹⁸F PET bone imaging of patients being treated using a Taylor spatial frame.

Unlabelled: Diagnosis of new bone growth in patients with compound tibia fractures or deformities treated using a Taylor spatial frame is difficult with conventional radiography because the frame obstructs the images and creates artifacts. The use of Na(18)F PET studies may help to eliminate this difficulty.

Methods: Patients were positioned on the pallet of a clinical PET/CT scanner and made as comfortable as possible with their legs immobilized.

Clinical application of in vivo treatment delivery verification based on PET/CT imaging of positron activity induced at high energy photon therapy.

The purpose of this study was to investigate in vivo verification of radiation treatment with high energy photon beams using PET/CT to image the induced positron activity. The measurements of the positron activation induced in a preoperative rectal cancer patient and a prostate cancer patient following 50 MV photon treatments are presented. A total dose of 5 and 8 Gy, respectively, were delivered to the tumors.

The relation between the blood glucose level and the FDG uptake of tissues at normal PET examinations.

Background: The influence of the blood glucose level on the tracer uptake of normal tissues at [18F]-2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) was retrospectively studied in examinations in clinical patients.

Methods: Five hundred examinations were evaluated in retrospect. The inclusion criteria were studies with a normal or near-normal FDG distribution.

Dynamic PET/CT measurements of induced positron activity in a prostate cancer patient after 50-MV photon radiation therapy.

Background: The purpose of this work was to reveal the research interest value of positron emission tomography (PET) imaging in visualizing the induced tissue activity post high-energy photon radiation treatment. More specifically, the focus was on the possibility of retrieving data such as tissue composition and physical half-lives from dynamic PET acquisitions, as positron-emitting radionuclides such as 15O, 11C, and 13N are produced in vivo during radiation treatment with high-energy photons (>15 MeV). The type, amount, and distribution of induced positron-emitting radionuclides depend on the irradiated tissue cross section, the photon spectrum, and the possible perfusion-driven washout.