Subacute Thyroiditis
Subacute thyroiditis (or de Quervain's disease) is a relatively uncommon form of thyroiditis characterized pathologically by the presence of extensive follicular cell destruction, extravasation of colloid and aggregation of histiocytes around colloid, coalescing into giant cells. There is strong but indirect evidence that this pathology may result as a reaction to a preceding viral infection, but immune mechanisms may also play a role. Patients often present with cervical pain, tenderness of...
Silent Thyroiditis
This form of thyroiditis is dominated by the pathological picture of a prominent lymphocytic infiltration of the gland. The evidence to date suggests that silent thyroiditis is a variant of lymphocytic thyroiditis. Both have a predilection to occur in the post-partum period but are also common in the non-pregnant state. In contrast to subacute thyroiditis, the clinical features are usually (but not invariably) milder. There is usually less or no pain in the cervical region and less or no...
Gastrointestinal
Peter Hollett and Ford Bursey Introduction A wide variety of nuclear medicine examinations are available for studying the function of the gastrointestinal tract. Tests include assessment of salivary gland function motility studies of the esophagus, stomach, small and large bowel measuring substrate absorption localization of gastrointestinal bleeding detection of Meckel's diverticulum (covered in Chapter 17) and tests for inflammatory bowel disease (covered in Chapter 12). This Chapter is not...
Myocardial Perfusion Imaging
David Greenberg Introduction Coronary artery disease (CAD) is the leading cause of death in North America. Atherosclerosis is by far the major cause of CAD. CAD can range from asymptomatic luminal irregularities to sudden total occlusion leading to myocardial infarction. Atherosclerotic CAD involves an intimal inflammatory reaction. Endothelial cell injury associated with coronary risk factors (smoking, hypertension, diabetes mellitus, hyperlipidemia) results in the entry...
H h j i i
Figure 14. 70 year old male with stable angina. The MPI study was performed for risk assessment. There is reduced activity in the anterior wall (narrow arrowhead), apex (short arrow) and septum (long arrow) at rest with improvement at rest. There is reduced activity inferiorly at stress with improvement of the distal inferior wall at rest (broad arrowhead). There is evidence of both LAD and RCA disease. perfusion imaging than with quantitative coronary angiography. An additional limitation of...
Info
New agents have been developed that retain estrogen's positive effects on bone, while attempting to minimize the associated risks and side effects. This class of drugs is termed Selective estrogen receptor modulators (SERMs) and include raloxifene and tamoxifen. Raloxifene reduces the risk of vertebral fractures by approximately 40 , and produces increases in bone density of approximately 3 at the spine in its first three years. It also lowers total and LDL cholesterol, does not stimulate the...
Radiation Effects and Safety
The International Commission on Radiological Protection (ICRP) declares that the primary aim of radiological protection is to provide an appropriate standard of protection for man without unduly limiting the beneficial practices giving rise to radiation exposure. Nuclear medicine professionals have a duty to fellow healthcare workers, patients and their families, research volunteers, the general public and the environment to ensure the safe and responsible handling of radioactive materials used...
Basal Cisterns Cisternogram
Alzheimer's disease. (A) SPECT brain perfusion in a patient presenting with dementia and moderate diffuse atrophy on CT scan. This single transaxial slice shows marked hypoperfusion bilaterally at the level of the parieto-occipital junctions (arrows). (B) 18F-FDG PET study (transaxial images) showing marked symmetrical glucose hypometabolism in the posterior parieto-temporal cortex (arrowheads). (Case provided by Dr. D. Worsely.) These scan patterns are typical of Alzheimer's disease....
