Nuclear medicine studies

Nuclear medicine studies may reveal information that is primarily anatomic in nature, or indicate the function of an organ on a regional basis (Table 1). These studies may be intended to identify new disease, confirm or deny suspected disease, or foUow the progress of treatment or the course of disease. The diseases may be relatively benign or extremely serious and can range from widespread medical problems such as ischemic heart disease to rarities such as Legge-Perthe s disease and malignant pheochromocytoma (7). 

Table 4. Nuclear Medicine Studies Performed in the United States, 1988-1993 ...

S. Jana, M.D. Blaufox, Nuclear medicine studies of the prostate, testes, and bladder, Semin. Nucl. Med. 36(1) (2006) 51-72. 

Many ft emitters do not eject electrons but positrons (ft partides), as for example 22Na and 65Zn. Short lived positron emitters are used in positron emission tomography (PET) in nuclear medicine studies, particularly of the brain. 

These are unique to scintillation cameras, known as Auger cameras, used in nuclear medicine studies. Approximately 19-91 PMTs are mounted on a Na(Tl) crystal used in the camera. These crystals are typically-thick. The number of PMTs, which are optically coupled to the back of the crystal, is determined by the size and shape of the crystal. A maximum amount of light will be received by the PMT nearest to the point of interaction compared with the other PMTs, which are positioned differently. The amount of light received in these PMTs is proportional to the solid angle subtended by the PMT. Therefore, X-Y-posi-tioning of the camera has to be controlled and known so that X-Y-coordinate of the y-Ray interaction can be assessed accurately. These data are stored in a computer and then processed or recorded on Polaroid or X-Ray films. 

Bleeding of diverticula is usually difficult to localise by imaging. Angiography may be indicated. Nuclear medicine studies may be performed to localise undear intestinal bleeding. When diverticulits is sus-perted clinically, endoscopy is contraindicated. After the acute phase of infl ammation, the colon should... 

Angiography and nuclear medicine studies no longer play a role in the primary diagnosis of HCC. 

Fig.25.8a-c. Left renal fracture in an 11-year-old girl. No associated intra-abdominal or bone lesion was found by CT (a). Delayed scan (b) showed opacification oftheurinomaby the contrast medium. In spite of this severe leak, the urinary excretory system remained patent. Six months later, followup ultrasound showed the fracture between two normalsized segments (c). Excellent function of the left kidney was shown by nuclear medicine studies (not shown)... 

Nuclear medicine studies can be performed in the late stage of renal trauma to evaluate the residual renal function. Either DMSA- Tc or MAG3- " Tc studies can be performed. MAG3- Tc is preferred in patients in whom excretion should be assessed as well. Functional MR urography is a promising examination in that field (Fig. 25.12). 

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