[show abstract][hide abstract] ABSTRACT: BACKGROUND: In mice, 18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/computed tomography (PET/CT) lymphography enables detailed imaging of the lymphatic system and quantification of lymph node function. If this applies to humans, it may improve staging of several malignancies. The aim of this study was to elucidate whether foot skin depots of 18F-FDG make PET/CT imaging of the lower extremity lymphatic system possible in man. FINDINGS: In four healthy volunteers, 18F-FDG depots (5 MBq in 0.1-mL isotonic saline) were injected intradermally in one foot and subcutaneously in the other. Activity was measured in blood samples drawn simultaneously from the great saphenous veins about 5 cm proximal to the ankle joints and a medial cubital vein before and every minute for 15 min after depot injection. Immediately thereafter, a low-dose CT was performed from the ankles to the pelvis followed by two consecutive PET scans of the same region.Blood activity increased faster and to a greater extent in the great saphenous veins compared to the medial cubital vein. PET/CT images showed activity in the superficial and deep veins of the lower extremities. No lymphatic collectors or nodes were visualized. CONCLUSION: Neither subcutaneous nor intradermal injection of 18F-FDG allows imaging of the lower extremity lymphatic system in man.
[show abstract][hide abstract] ABSTRACT: Two scientific committees (physics & dosimetry) of the European Association of Nuclear Medicine (EANM) commented on the draft 'Radiation Protection 162: radiation criteria for acceptability of radiological equipment used in diagnostic radiology, nuclear medicine and radiotherapy' (RP 162). This document updates and extends the acceptability criteria mentioned in 'Radiation Protection 91' and is an important means to further improve the quality of medical procedures involving ionising radiation. While the EANM committees support the presented framework as described in the introductory chapter, they have suggested substantial changes to the specific suspension levels for nuclear medicine equipment. During the revision process, an agreed consensus position was reached. The EANM considers RP 162 a significant improvement of RP 91 and endorses the document.
[show abstract][hide abstract] ABSTRACT: PURPOSE: To provide a guideline curriculum covering theoretical and practical aspects of education and training for Medical Physicists in Nuclear Medicine within Europe. MATERIAL AND METHODS: National training programmes of Medical Physics, Radiation Physics and Nuclear Medicine physics from a range of European countries and from North America were reviewed and elements of best practice identified. An independent panel of experts was used to achieve consensus regarding the content of the curriculum. RESULTS: Guidelines have been developed for the specialist theoretical knowledge and practical experience required to practice as a Medical Physicist in Nuclear Medicine in Europe. It is assumed that the precondition for the beginning of the training is a good initial degree in Medical Physics at master level (or equivalent). The Learning Outcomes are categorised using the Knowledge, Skill and Competence approach along the lines recommended by the European Qualifications Framework. The minimum level expected in each topic in the theoretical knowledge and practical experience sections is intended to bring trainees up to the requirements expected of a Medical Physicist entering the field of Nuclear Medicine. CONCLUSIONS: This new joint EANM/EFOMP European guideline curriculum is a further step to harmonise specialist training of Medical Physicists in Nuclear Medicine within Europe. It provides a common framework for national Medical Physics societies to develop or benchmark their own curricula. The responsibility for the implementation and accreditation of these standards and guidelines resides within national training and regulatory bodies.
[show abstract][hide abstract] ABSTRACT: Multi-centre trials are an important part of proving the efficacy of procedures, drugs and interventions. Imaging components in such trials are becoming increasingly common; however, without sufficient control measures the usefulness of these data can be compromised. This paper describes a framework for performing high-quality multi-centre trials with single photon emission computed tomography (SPECT), using a pan-European initiative to acquire a normal control dopamine transporter brain scan database as an example.
A framework to produce high-quality and consistent SPECT imaging data was based on three key areas: quality assurance, the imaging protocol and system characterisation. Quality assurance was important to ensure that the quality of the equipment and local techniques was good and consistently high; system characterisation helped understand and where possible match the performance of the systems involved, whereas the imaging protocol was designed to allow a degree of flexibility to best match the characteristics of each imaging device.
A total of 24 cameras on 15 sites from 8 different manufacturers were evaluated for inclusion in our multi-centre initiative. All results matched the required level of specification and each had their performance characterised. Differences in performance were found between different system types and cameras of the same type. Imaging protocols for each site were modified to match their individual characteristics to produce comparable high-quality SPECT images.
A framework has been designed to produce high-quality data for multi-centre SPECT studies. This framework has been successfully applied to a pan-European initiative to acquire a healthy control dopamine transporter image database.
European Journal of Nuclear Medicine 11/2011; 39(1):188-97. · 4.53 Impact Factor
[show abstract][hide abstract] ABSTRACT: A joint initiative of the European Association of Nuclear Medicine (EANM) Neuroimaging Committee and EANM Research Ltd. aimed to generate a European database of [(123)I]FP-CIT single photon emission computed tomography (SPECT) scans of healthy controls. This study describes the characterization and harmonization of the imaging equipment of the institutions involved.
(123)I SPECT images of a striatal phantom filled with striatal to background ratios between 10:1 and 1:1 were acquired on all the gamma cameras with absolute ratios measured from aliquots. The images were reconstructed by a core lab using ordered subset expectation maximization (OSEM) without corrections (NC), with attenuation correction only (AC) and additional scatter and septal penetration correction (ACSC) using the triple energy window method. A quantitative parameter, the simulated specific binding ratio (sSBR), was measured using the "Southampton" methodology that accounts for the partial volume effect and compared against the actual values obtained from the aliquots. Camera-specific recovery coefficients were derived from linear regression and the error of the measurements was evaluated using the coefficient of variation (COV).
The relationship between measured and actual sSBRs was linear across all systems. Variability was observed between different manufacturers and, to a lesser extent, between cameras of the same type. The NC and AC measurements were found to underestimate systematically the actual sSBRs, while the ACSC measurements resulted in recovery coefficients close to 100% for all cameras (AC range 69-89%, ACSC range 87-116%). The COV improved from 46% (NC) to 32% (AC) and to 14% (ACSC) (p < 0.001).
A satisfactory linear response was observed across all cameras. Quantitative measurements depend upon the characteristics of the SPECT systems and their calibration is a necessary prerequisite for data pooling. Together with accounting for partial volume, the correction for scatter and septal penetration is essential for accurate quantification.
European Journal of Nuclear Medicine 04/2011; 38(8):1529-40. · 4.53 Impact Factor
[show abstract][hide abstract] ABSTRACT: Many neuropathic pain conditions are characterized by abnormal responses to noxious or innocuous mechanical stimulation, including wind-up pain. Whereas previous brain imaging studies have explored the cerebral correlates of hyperalgesia and allodynia, no studies are available on mechanical-induced wind-up pain in neuropathic pain patients. We therefore used positron emission tomography (PET) to investigate the cerebral response pattern of mechanical wind-up pain in a homogenous group of 10 neuropathic pain patients with long-standing postherniotomy pain in the groin area. Patients were scanned in the following conditions: (1) rest; (2) wind-up pain, induced by 2 Hz von Frey stimulation in the painful area; (3) non-painful 2 Hz von Frey stimulation in the homologous contralateral area and (4) tonic pressure pain in the homologous contralateral area. A direct comparison between wind-up pain and non-painful von Frey stimulation revealed that the former more strongly activated contralateral secondary somatosensory cortex, insula, anterior cingulate cortex, right dorsolateral prefrontal cortex, thalamus and cerebellum. In addition, wind-up pain also activated the sublenticular extended amygdala (SLEA) and the brain stem. A direct comparison between wind-up pain and pressure pain revealed that both activated a largely overlapping network. Since no de novo brain areas were activated by wind-up pain, our data suggest that the processes specific to wind-up pain do not occur at the cerebral level.
European journal of pain (London, England) 02/2011; 15(7):698.e1-16. · 3.37 Impact Factor
[show abstract][hide abstract] ABSTRACT: The positron emission tomography in combination with CT in hybrid, cross-modality imaging systems (PET/CT) gains more and more importance as a part of the treatment-planning procedure in radiotherapy. Positron emission tomography (PET), as a integral part of nuclear medicine imaging and non-invasive imaging technique, offers the visualization and quantification of pre-selected tracer metabolism. In combination with the structural information from CT, this molecular imaging technique has great potential to support and improve the outcome of the treatment-planning procedure prior to radiotherapy. By the choice of the PET-Tracer, a variety of different metabolic processes can be visualized. First and foremost, this is the glucose metabolism of a tissue as well as for instance hypoxia or cell proliferation. This paper comprises the system characteristics of hybrid PET/CT systems. Acquisition and processing protocols are described in general and modifications to cope with the special needs in radiooncology. This starts with the different position of the patient on a special table top, continues with the use of the same fixation material as used for positioning of the patient in radiooncology while simulation and irradiation and leads to special processing protocols that include the delineation of the volumes that are subject to treatment planning and irradiation (PTV, GTV, CTV, etc.). General CT acquisition and processing parameters as well as the use of contrast enhancement of the CT are described. The possible risks and pitfalls the investigator could face during the hybrid-imaging procedure are explained and listed. The interdisciplinary use of different imaging modalities implies a increase of the volume of data created. These data need to be stored and communicated fast, safe and correct. Therefore, the DICOM-Standard provides objects and classes for this purpose (DICOM RT). Furthermore, the standard DICOM objects and classes for nuclear medicine (NM, PT) and computed tomography (CT) are used to communicate the actual image data created by the modalities. Care must be taken for data security, especially when transferring data across the (network-) borders of different hospitals. Overall, the most important precondition for successful integration of functional imaging in RT treatment planning is the goal orientated as well as close and thorough communication between nuclear medicine and radiotherapy departments on all levels of interaction (personnel, imaging protocols, GTV delineation, and selection of the data transfer method).
Radiotherapy and Oncology 09/2010; 96(3):288-97. · 4.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: Positron emission tomography (PET) has proven to be a clinically valuable imaging modality, particularly for oncology staging and therapy follow-up. The introduction of combined PET/CT imaging has helped address challenging imaging situations when anatomical information on PET-only was inadequate for accurate lesion localization. After a decade of PET/CT these combined systems have matured technically. Today, whole-body oncology staging is available with PET/CT in 15 min, or less. This review details recent developments in combined PET/CT instrumentation and points to implications for major applications in clinical oncology.
European journal of radiology 03/2010; 73(3):452-60. · 2.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although magnetic resonance imaging (MRI) is now considered the gold standard in second-line imaging of patients with suspected scaphoid fracture and negative radiographs, bone scintigraphy can be used in patients with pacemakers, metallic implants, or other contraindications to MRI. Bone scintigraphy is highly sensitive for the detection of fractures, but exact localization of scintigraphic lesions may be difficult and can negatively affect diagnostic accuracy.
To investigate the influence of image fusion of planar bone scintigraphy and radiographs on image interpretation in patients with suspected scaphoid fracture.
In 24 consecutive patients with suspected scaphoid fracture, a standard planar bone scintigraphy of both hands was supplemented with fusion imaging of the injured wrist. Standard and fusion images were evaluated independently by three experienced nuclear medicine physicians. In addition to the diagnosis, the degree of diagnostic confidence was scored in each case.
The addition of fusion images changed the interpretation of each of the three observers in seven, four, and two cases, respectively, reducing the number of positive interpretations of two of the observers from 11 and nine cases to six and seven cases, respectively. The degree of diagnostic confidence increased significantly in two observers, and interobserver agreement increased in all three pairs of observers from 0.83, 0.57, and 0.73 to 0.89, 0.8, and 0.9, respectively.
Image fusion of planar bone scintigrams and radiographs has a significant influence on image interpretation and increases both diagnostic confidence and interobserver agreement.
[show abstract][hide abstract] ABSTRACT: Single-photon emission computed tomography (SPECT) with [123I]FP-CIT is a marker for loss of presynaptic dopamine transporters in the striatum in Parkinson's disease (PD). We used [123I]FP-CIT SPECT in order to evaluate binding to the dopamine transporter before and after neurosurgical treatment with bilateral stimulation in the subthalamic nucleus (STN).
Thirty-five patients with levodopa-responsive PD were examined with [123I]FP-CIT SPECT pre-operatively (baseline scan: mean 3 months before surgery), and 3 and 12 months after surgery.
Pre-operatively, all patients already had substantial signs of severe nigrostriatal neuronal loss as determined from the [123I]FP-CIT SPECT scans. One year after surgery the specific [123I]FP-CIT binding to the striatum was significantly reduced by 10.3% compared with the pre-operative baseline scan. The mean time span from the baseline scan before surgery to the follow-up scan 1 year after surgery was 16.2 months. Hence, the rate of reduction equals a mean annual reduction of 7.7%. A comparable control group of patients with PD who did not undergo surgery was also examined longitudinally. In this group the specific binding of [123I]FP-CIT was reduced by 6.7% per year.
The specific binding of [123I]FP-CIT was reduced equally in the STN-stimulated patients and a group of non-operated PD patients with advanced disease. Our study does not support the notion that electrode implantation and STN stimulation exert a neuroprotective effect by themselves.
European journal of nuclear medicine and molecular imaging 05/2007; 34(4):508-16. · 5.11 Impact Factor