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[Degenerative cerebellar diseases and differential diagnoses].
Reith, W, Roumia, S, Dietrich, P
Der Radiologe. 2016;(11):976-982
Abstract
CLINICAL/METHODICAL ISSUE Cerebellar syndromes result in distinct clinical symptoms, such as ataxia, dysarthria, dysmetria, intention tremor and eye movement disorders. STANDARD RADIOLOGICAL METHODS In addition to the medical history and clinical examination, imaging is particularly important to differentiate other diseases, such as hydrocephalus and multi-infarct dementia from degenerative cerebellar diseases. Degenerative diseases with cerebellar involvement include Parkinson's disease, multiple system atrophy as well as other diseases including spinocerebellar ataxia. ACHIEVEMENTS In addition to magnetic resonance imaging (MRI), nuclear medicine imaging investigations are also helpful for the differentiation. PRACTICAL RECOMMENDATIONS Axial fluid-attenuated inversion recovery (FLAIR) and T2-weighted sequences can sometimes show a signal increase in the pons as a sign of degeneration of pontine neurons and transverse fibers in the basilar part of the pons. The imaging is particularly necessary to exclude other diseases, such as normal pressure hydrocephalus (NPH), multi-infarct dementia and cerebellar lesions.
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2.
Role of isotope scan, including positron emission tomography/computed tomography, in nodular goitre.
Giovanella, L, Ceriani, L, Treglia, G
Best practice & research. Clinical endocrinology & metabolism. 2014;(4):507-18
Abstract
Nuclear medicine techniques were first used in clinical practice for diagnosing and treating thyroid diseases in the 1950s, and are still an integral part of thyroid nodules work-up. Thyroid imaging with iodine or iodine-analogue isotopes is the only examination able to prove the presence of autonomously functioning thyroid tissue, which excludes malignancy with a high probability. In addition, a thyroid scan with technetium-99m-methoxyisobutylisonitrile is able to avoid unnecessary surgical procedures for cytologically inconclusive thyroid nodules, as confirmed by meta-analysis and cost-effectiveness studies. Finally, positron emission tomography alone, and positron emission tomography combined with computed tomography scans with (18)F-fluoro-2-deoxy-d-glucose are also promising for diagnosing thyroid diseases, but further studies are needed before introducing them to clinical practice.
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3.
PET/CT imaging in systemic lupus erythematosus.
Curiel, R, Akin, EA, Beaulieu, G, DePalma, L, Hashefi, M
Annals of the New York Academy of Sciences. 2011;:71-80
Abstract
Systemic lupus erythematosus (SLE) is the classical immune-complex disease. Involvement of vital organs, particularly the kidneys and brain, accounts for significant morbidity and mortality. A number of imaging tools are currently available for evaluation of inflammatory conditions. By targeting the increased glucose uptake of infiltrating granulocytes and tissue macrophages, positron emission tomography with fluorine-18 fluorodeoxyglucose ([(18) F]FDG PET/CT) has been shown to delineate inflammation with high sensitivity. Because activated lymphocytes have increased glucose metabolism, [(18) F]FDG PET has been successfully used to visualize large concentrations of these cells in lymphoid organs where antigen presentation and lymphocyte activation occur. Widespread increased FDG uptake in lymph nodes of patients with active SLE, as well as increased thymic uptake, has been described. The most prevalent and dramatic PET/CT finding in neuropsychiatric SLE (NP-SLE) patients is parieto-occipital hypometabolism. In conclusion, PET/CT has become an excellent ancillary tool to assess disease activity and prognosis in SLE patients.
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4.
Role of 18F-DOPA PET/CT imaging in congenital hyperinsulinism.
Ismail, D, Hussain, K
Reviews in endocrine & metabolic disorders. 2010;(3):165-9
Abstract
Congenital hyperinsulinism is a leading cause of severe hypoglycaemia in the newborn period. There are two (diffuse and focal) histological subtypes of congenital hyperinsulinism. The diffuse form affects the entire pancreas and if medically unresponsive will require a near total (95%-98%) pancreatectomy. The focal form affects only a small region of the pancreas (with the rest of the pancreas being normal in endocrine and exocrine function) and only requires a limited pancreatectomy. This limited section of the focal lesion has the potential for curing the patient. Thus the pre-operative differentiation of these two subgroups is extremely important. Recent advances in Fluorine-18-L-dihydroxyphenylalanine positron emission tomography ((18)F-DOPA PET/CT) have radically changed the clinical approach to patient with congenital hyperinsulinism. In most patients this novel imaging technique is able to offer precise pre-operative localisation of the focal lesion, thus guiding the extent of surgical resection.
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5.
Molecular imaging in thyroid cancer.
Heston, TF, Wahl, RL
Cancer imaging : the official publication of the International Cancer Imaging Society. 2010;(1):1-7
Abstract
Molecular imaging plays an important role in the evaluation and management of thyroid cancer. The routine use of thyroid scanning in all thyroid nodules is no longer recommended by many authorities. In the initial work-up of a thyroid nodule, radioiodine imaging can be particularly helpful when the thyroid stimulating hormone level is low and an autonomously functioning nodule is suspected. Radioiodine imaging can also be helpful in the 10-15% of cases for which fine-needle aspiration biopsy is indeterminate. Therapy of confirmed thyroid cancer frequently involves administration of iodine-131 after surgery to ablate remnant tissue. In the follow-up of thyroid cancer patients, increased thyroglobulin levels will often prompt the empiric administration of 131I followed by whole body radioiodine imaging in the search for recurrent or metastatic disease. 131I imaging of the whole body and blood pharmacokinetics can be used to determine if higher doses of 131I can be given in thyroid cancer. The utility of [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) is steadily increasing. FDG is primarily taken up by dedifferentiated thyroid cancer cells, which are poorly iodine avid. Thus, it is particularly helpful in the patient with an increased thyroglobulin but negative radioiodine scan. FDG PET is also useful in the patient with a neck mass but unknown primary, in patients with aggressive (dedifferentiated) thyroid cancer, and in patients with differentiated cancer where histologic transformation to dedifferentiation is suspected. In rarer types of thyroid cancer, such as medullary thyroid cancer, FDG and other tracers such as 99mTc sestamibi, [11C]methionine, [111In]octreotide, and [68Ga]somatostatin receptor binding reagents have been utilized. 124I is not widely available, but has been used for PET imaging of thyroid cancer and will likely see broader applicability due to the advantages of PET methodology.
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6.
Imaging of gynecologic malignancies with FDG PET-CT: case examples, physiologic activity, and pitfalls.
De Gaetano, AM, Calcagni, ML, Rufini, V, Valentini, AL, Gui, B, Giordano, A, Bonomo, L
Abdominal imaging. 2009;(6):696-711
Abstract
The utilization of 2-[fluorine 18] fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in combination with computed tomography (CT) in the assessment of gynecologic malignancies has been rapidly growing in recent years; however, its role in clinical practice has yet to be established. A number of pitfalls are commonly encountered, including normal physiologic activity in bowel loops and blood vessels, or focal retained activity in ureters and urinary bladder. Increased uptake has also been reported in many benign pelvic processes and in premenopausal patients; endometrial activity changes cyclically, whereas increased ovarian uptake may be functional. FDG PET-CT has an emerging role in staging nodal disease and in the evaluation of local recurrence or peritoneal spread of gynecologic malignancies and is also useful in monitoring response to therapy and in long-term follow-up. FDG PET-CT is most suitable in patients with high tumor markers and negative or uncertain conventional imaging data. Patient preparation, proper scanning protocol, combined assessment of PET and CT data, and the evaluation of conventional imaging findings are essential to define disease and to avoid diagnostic pitfalls.
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7.
Prognosis and reevaluation of lung cancer by positron emission tomography imaging.
Erasmus, JJ, Rohren, E, Swisher, SG
Proceedings of the American Thoracic Society. 2009;(2):171-9
Abstract
Positron emission tomography (PET) imaging using (18)F-2-deoxy-D-glucose, a D-glucose analog labeled with fluorine-18 (FDG-PET), is being evaluated in the assessment of prognosis and therapeutic response in patients with non-small cell lung cancer. FDG-PET imaging has the potential to allow more appropriate selection of patients for surgical resection and for neoadjuvant and aduvant chemotherapy as well as chemoradiation. Currently, the absence of standardization in how FDG-PET images are obtained and interpreted limits its widespread clinical utility. Although prospective multi-institutional trials and standardization of FDG-PET imaging protocols are required for the true utility to be determined, the evolving experience with FDG-PET imaging indicates a greater and integral role in treatment decisions. This article will discuss the assessment of prognosis and treatment response in patients with non-small cell lung cancer using FDG-PET, and will emphasize potential advantages and limitations in clinical management.
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8.
The role of 18F-FDG PET/CT in the evaluation of oesophageal carcinoma.
Chowdhury, FU, Bradley, KM, Gleeson, FV
Clinical radiology. 2008;(12):1297-309
Abstract
Integrated positron-emission tomography/computed tomography (PET/CT) with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG) is now established in the management of oncology patients. With increasing availability and a constantly advancing body of evidence, the role of FDG PET/CT in oesophageal cancer is set to expand to include initial staging, assessment of disease response, therapy planning, and detection of disease recurrence. This article reviews the utility of FDG PET/CT in the management of oesophageal carcinoma, discussing its role and limitations in the imaging of these patients.
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9.
Contrast media: procedural capacities and potential risks.
Davidson, CJ, Erdogan, AK
Reviews in cardiovascular medicine. 2008;:S24-34
Abstract
Contrast media are known to have transient hemodynamic properties that can influence a patient's clinical status, including heart rate variability and blood pressure. These changes have the potential to impact the diagnostic quality of CT scans. Although most patients are able to receive contrast media without significant adverse reactions, events occur in a minority of cases. These reactions range from mild discomfort (injection-associated pain and heat sensation) to more significant cardiac, renal, and hypersensitivity reactions. The incidence of adverse reactions varies with the type of contrast media used, and several randomized trials have elucidated the cardiac and renal differences among agents. Risk factors for contrast-induced acute kidney injury (CIAKI) have been established, with baseline kidney disease amplified by the presence of diabetes constituting the highest-risk patient group. Strategies for preventing CIAKI include antioxidant therapy, hydration regimens, and choice of contrast agents. Enhanced knowledge on the part of physicians and medical personnel regarding the properties and potential side effects of iodinated contrast agents should lead to improved patient safety and efficacy when performing radiologic examinations.
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10.
Roles of nuclear cardiology, cardiac computed tomography, and cardiac magnetic resonance: assessment of patients with suspected coronary artery disease.
Berman, DS, Hachamovitch, R, Shaw, LJ, Friedman, JD, Hayes, SW, Thomson, LE, Fieno, DS, Germano, G, Slomka, P, Wong, ND, et al
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2006;(1):74-82
Abstract
Noninvasive cardiac imaging is now central to the diagnosis and management of patients with known or suspected chronic coronary artery disease (CAD). Although rest echocardiography has become the most common of the techniques, nuclear cardiology and more recently cardiac computed tomography (CCT) and cardiac magnetic resonance (CMR) play important roles in this regard. This review examines the current applications and interactions of noninvasive cardiac imaging approaches for the assessment of patients with suspected CAD. In addition to considering the strengths and weaknesses of each technique, this review attempts to provide a guide to the selection of a test (or tests) that is based on the question being asked and the ability of each test to answer this question. In patients with suspected CAD, the pretest likelihood of disease, a clinical assessment, becomes the most important determinant of the initial test. If the likelihood is very low, no testing is needed. However, if the likelihood is low, recent data suggest that assessment of early atherosclerosis is likely to be the most useful and cost-effective test. In patients who have an intermediate likelihood of CAD, nuclear cardiology with myocardial perfusion SPECT (MPS) becomes highly valuable; however, coronary CT angiography (CTA), with fast 16-slice or greater scanners, may emerge as the initial test of choice. MPS would then be used if the CTA is inconclusive or if there is a need to assess the functional significance of a stenosis defined by CTA. Coronary CTA, however, is not yet widely available and is limited in patients with dense coronary calcification. In older patients with a high likelihood of CAD, MPS may be the initial test of choice, since a high proportion of these patients have too much coronary calcium to allow accurate assessment of the presence of coronary stenoses. PET/CT or SPECT/CT could emerge as important modalities combining the advantages of each modality. While CMR has great promise as a radiation-free and contrast-free "one-stop" shop, it currently lags behind CTA for noninvasive coronary angiography. Nonetheless, CMR clearly has the potential for this application and has already emerged as a highly effective method for assessing ventricular function, myocardial mass, and myocardial viability, and there is increasing use of this approach for clinical rest and stress perfusion measurements. CMR is particularly valuable in distinguishing ischemic from nonischemic cardiomyopathy. While CT and CMR are likely to grow considerably in diagnostic evaluation over the next several years, MPS and PET will continue to be very valuable techniques for this purpose.