Nuclear Medicine Imaging and Therapy in Rheumatology

Author(s):  
Adil Al-Nahhas ◽  
Imene Zerizer

The application of nuclear medicine techniques in the diagnosis and management of rheumatological conditions relies on its ability to detect physiological and pathological changes in vivo, usually at an earlier stage compared to structural changes visualized on conventional imaging. These techniques are based on the in-vivo administration of a gamma-emitting radionuclide whose distribution can be monitored externally using a gamma camera. To guide a radionuclide to the area of interest, it is usually bound to a chemical label to form a ’radiopharmaceutical’. There are hundreds of radiopharmaceuticals in clinical use with different ’homing’ mechanisms, such as 99 mTc HDP for bone scan and 99 mTc MAA for lung scan. Comparing pre- and posttherapy scans can aid in monitoring response to treatment. More recently, positron emission tomography combined with simultaneous computed tomography (PET/CT) has been introduced into clinical practice. This technique provides superb spatial resolution and anatomical localization compared to gamma-camera imaging. The most widely used PET radiopharmaceutical, flurodeoxyglucose (18F-FDG), is a fluorinated glucose analogue, which can detect hypermetabolism and has therefore been used in imaging and monitoring response to treatment of a variety of cancers as well as inflammatory conditions such as vasculitis, myopathy, and arthritides. Other PET radiopharmaceuticals targeting inflammation and activated macrophages are becoming available and could open new frontiers in PET imaging in rheumatology. Nuclear medicine procedures can also be used therapeutically. Beta-emitting radiopharmaceuticals, such as yttrium-90, invoke localized tissue damage at the site of injection and can be used in the treatment of synovitis.

Author(s):  
Adil Al-Nahhas ◽  
Imene Zerizer

The application of nuclear medicine techniques in the diagnosis and management of rheumatological conditions relies on its ability to detect physiological and pathological changes in vivo, usually at an earlier stage compared to structural changes visualized on conventional imaging. These techniques are based on the in-vivo administration of a gamma-emitting radionuclide whose distribution can be monitored externally using a gamma camera. To guide a radionuclide to the area of interest, it is usually bound to a chemical label to form a 'radiopharmaceutical'. There are hundreds of radiopharmaceuticals in clinical use with different 'homing' mechanisms, such as 99 mTc HDP for bone scan and 99 mTc MAA for lung scan. Comparing pre- and posttherapy scans can aid in monitoring response to treatment. More recently, positron emission tomography combined with simultaneous computed tomography (PET/CT) has been introduced into clinical practice. This technique provides superb spatial resolution and anatomical localization compared to gamma-camera imaging. The most widely used PET radiopharmaceutical, flurodeoxyglucose (18F-FDG), is a fluorinated glucose analogue, which can detect hypermetabolism and has therefore been used in imaging and monitoring response to treatment of a variety of cancers as well as inflammatory conditions such as vasculitis, myopathy, and arthritides. Other PET radiopharmaceuticals targeting inflammation and activated macrophages are becoming available and could open new frontiers in PET imaging in rheumatology. Nuclear medicine procedures can also be used therapeutically. Beta-emitting radiopharmaceuticals, such as yttrium-90, invoke localized tissue damage at the site of injection and can be used in the treatment of synovitis.


2007 ◽  
Vol 50 (spe) ◽  
pp. 91-96 ◽  
Author(s):  
Camila Godinho Ribeiro ◽  
Regina Moura ◽  
Rosane de Figueiredo Neves ◽  
Jean Pierre Spinosa ◽  
Mario Bernardo-Filho

Functional imaging with positron emission tomography and single photon emission computed tomography is capable of visualizing subtle changes in physiological function in vivo. Erectile dysfunction(ED) diminishes quality of life for affected men and their partners. Identification of neural substrates may provide information regarding the pathophysiology of types of sexual dysfunction originating in the brain. The aim of this work is to verify the approaches of the nuclear medicine techniques in the evaluation of the erectile function/disfunction. A search using the words ED and nuclear medicine, ED and scintigraphy, ED and spect and ED and pet was done in the PubMed. The number of citations in each subject was determined. Neuroimaging techniques offer insight into brain regions involved in sexual arousal and inhibition. To tackle problems such as hyposexual disorders or ED caused by brain disorders, it is crucial to understand how the human brain controls sexual arousal and penile erection.


2001 ◽  
Vol 40 (03) ◽  
pp. 59-70 ◽  
Author(s):  
W. Becker ◽  
J. Meiler

SummaryFever of unknown origin (FUO) in immunocompetent and non neutropenic patients is defined as recurrent fever of 38,3° C or greater, lasting 2-3 weeks or longer, and undiagnosed after 1 week of appropriate evaluation. The underlying diseases of FUO are numerous and infection accounts for only 20-40% of them. The majority of FUO-patients have autoimmunity and collagen vascular disease and neoplasm, which are responsible for about 50-60% of all cases. In this respect FOU in its classical definition is clearly separated from postoperative and neutropenic fever where inflammation and infection are more common. Although methods that use in-vitro or in-vivo labeled white blood cells (WBCs) have a high diagnostic accuracy in the detection and exclusion of granulocytic pathology, they are only of limited value in FUO-patients in establishing the final diagnosis due to the low prevalence of purulent processes in this collective. WBCs are more suited in evaluation of the focus in occult sepsis. Ga-67 citrate is the only commercially available gamma emitter which images acute, chronic, granulomatous and autoimmune inflammation and also various malignant diseases. Therefore Ga-67 citrate is currently considered to be the tracer of choice in the diagnostic work-up of FUO. The number of Ga-67-scans contributing to the final diagnosis was found to be higher outside Germany than it has been reported for labeled WBCs. F-l 8-2’-deoxy-2-fluoro-D-glucose (FDG) has been used extensively for tumor imaging with PET. Inflammatory processes accumulate the tracer by similar mechanisms. First results of FDG imaging demonstrated, that FDG may be superior to other nuclear medicine imaging modalities which may be explained by the preferable tracer kinetics of the small F-l 8-FDG molecule and by a better spatial resolution of coincidence imaging in comparison to a conventional gamma camera.


2013 ◽  
pp. 159-166
Author(s):  
Giorgio Treglia ◽  
Ernesto Cason ◽  
Giorgio Fagioli

Introduction: Positron-emission tomography (PET) and single photon emission computed tomography (SPECT) are effective diagnostic imaging tools in several clinical settings. The aim of this article (the second of a 2-part series) is to examine some of the more recent applications of nuclear medicine imaging techniques, particularly in the fields of neurology, cardiology, and infection/inflammation. Discussion: A review of the literature reveals that in the field of neurology nuclear medicine techniques are most widely used to investigate cognitive deficits and dementia (particularly those associated with Alzheimer disease), epilepsy, and movement disorders. In cardiology, SPECT and PET also play important roles in the work-up of patients with coronary artery disease, providing accurate information on the state of the myocardium (perfusion, metabolism, and innervation). White blood cell scintigraphy and FDG-PET are widely used to investigate many infectious/inflammatory processes. In each of these areas, the review discusses the use of recently developed radiopharmaceuticals, the growth of tomographic nuclear medicine techniques, and the ways in which these advances are improving molecular imaging of biologic processes at the cellular level.


1994 ◽  
Vol 7 (3) ◽  
pp. 124-139 ◽  
Author(s):  
Richard J. Hammes ◽  
John W. Babich

Positron emission tomography {PET) is a nuclear medicine imaging technique which exploits the unique physical characteristics of radionuclides that decay by positron emission. These characteristics allow for in vivo quantitative measurement of three-dimensional distributions of radioactivity with a spatial resolution of 5 mm using current detector technology. In addition to these physical advantages, PET is the only imaging technique that can use the short-lived positron emitting radionuclides of the so-called “organic” elements: carbon (C-11), nitrogen (N-13), and oxygen (0–15). These elements are the building blocks of physiological compounds and can be used to study most enzymes, receptors, and other metabolically important compounds and their associated reactions. PET allows for the study of a variety of physiological and biochemical processes through the application of particular radiopharmaceuticals. PET has also been used to study the interaction of receptor-specific ligands in several receptor systems including dopaminergic, adrenergic, serotinergic, and opiod. C-11 and F-18 labeled receptor ligands have been used to study receptor selectivity and receptor concentrations in vivo. Recently, PET has been used to measure the pharmacokinetics of several novel antibiotics in humans allowing the direct measurement of tissue concentrations and correlation with classical pharmacokinetic parameters. This review discusses some of the current applications of PET in more detail.


1999 ◽  
Vol 19 (2) ◽  
pp. 218-229 ◽  
Author(s):  
Evan D. Morris ◽  
Svetlana I. Chefer ◽  
Mark A. Lane ◽  
Raymond F. Muzic ◽  
Dean F. Wong ◽  
...  

The relation between striatal dopamine D2 receptor binding and aging was investigated in rhesus monkeys with PET. Monkeys (n = 18, 39 to 360 months of age) were scanned with 11C-raclopride; binding potential in the striatum was estimated graphically. Because our magnetic resonance imaging analysis revealed a concomitant relation between size of striatum and age, the dynamic positron emission tomography (PET) data were corrected for possible partial volume (PV) artifacts before parameter estimation. The age-related decline in binding potential was 1% per year and was smaller than the apparent effect if the age-related change in size was ignored. This is the first in vivo demonstration of a decline in dopamine receptor binding in nonhuman primates. The rate of decline in binding potential is consistent with in vitro findings in monkeys but smaller than what has been measured previously in humans using PET. Previous PET studies in humans, however, have not corrected for PV error, although a decline in striatal size with age has been demonstrated. The results of this study suggest that PV correction must be applied to PET data to accurately detect small changes in receptor binding that may occur in parallel with structural changes in the brain.


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