The development and use of positron emission tomography (PET) radiotracers has tremendous potential for the advancement of oncologic imaging. There has been preclinical development on hundreds of PET radiotracers, and the most promising have advanced into clinical trials. As of 2018 the US Food and Drug Administration (FDA) has approved five PET radiotracers which are used for oncologic imaging: 1. 18F-fluorodeoxyglucose (FDG) 2. 18F-sodium fluoride (Na18F)…

All imaging modalities may be compromised by artifacts which obscure malignancy or mimic malignancy. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) may be compromised by a multitude of artifacts, primarily associated with technical performance of PET/CT scanners and unexpected biodistribution of FDG. A few of the more common artifacts on FDG PET/CT are discussed here. Motion Patient motion during acquisition of PET/CT images may introduce multiple…

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18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has become an important modality in the evaluation of lymph nodes in oncology patients, including the central role FDG PET/CT plays in managing patients with lymphoma and the ability for FDG PET to detect nodal metastases in subcentimeter nodes which may be overlooked on CT or magnetic resonance (MR). However, it is important to realize that there are multiple…

The male pelvis on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is more straightforward than the female pelvis. The testes may demonstrate physiologic FDG avidity. FDG-avid foci within the prostate may represent benign focal prostatitis or prostate cancer. Testes You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here

The female pelvis can be difficult to evaluate on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). The endometrium and ovaries may demonstrate physiologic FDG avidity. Benign leiomyomata of the myometrium may be FDG avid. In addition, physiologic FDG avidity in the adjacent bowel and urinary tract may obscure FDG-avid ovarian or uterine lesions. Nevertheless, FDG PET/CT has demonstrated value for detecting unsuspected nodal and distant metastases…

The urinary tract is one the most difficult organ systems of the body to evaluate on F18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). This is because of physiologic excretion of FDG through the kidneys, ureters, and bladder. FDG in urine may hide FDG-avid malignancy or be mistaken for FDG-avid malignancy. Combine this with the fact that neoplasms of the urinary tract are often only mildly FDG…

The peritoneum is a membranous lining of the abdominal cavity and organs. The parietal peritoneum lines the abdominal cavity, whereas the visceral peritoneum lines the intraperitoneal organs. Between layers of the peritoneum is the peritoneal cavity, a potential space. This potential space is normally not identifiable on imaging studies, unless the space becomes filled with fluids, air, or masses. Masses in the peritoneum include both benign…

The gastrointestinal (GI) tract poses challenges for interpretation on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). The esophagus, stomach, and small and large bowel may all demonstrate physiologic FDG avidity, and physiologic FDG avidity may be even more intense than a coexisting malignancy. The areas of physiologic FDG avidity on imaging at one time point may not be the same as the areas of physiologic FDG…

The differential diagnosis for adrenal lesions includes malignant neoplasms, benign neoplasms, and benign nonneoplastic processes. The most common adrenal malignancies by far are metastases. Additional adrenal malignancies include lymphoma, malignant pheochromocytomas, and adrenal cortical carcinomas. The most common benign adrenal neoplasms are adenomas. Additional benign adrenal neoplasms include myelolipomas, benign pheochromocytomas, and ganglioneuromas. Nonneoplastic processes that involve the adrenal gland may include physiologic adrenal fluorodeoxyglucose (FDG)…

The differential for focal pancreatic lesions depends on whether the lesion is solid or cystic. Solid pancreatic lesions include primary pancreatic adenocarcinoma, pancreatic neuroendocrine tumors (PNETs), lymphoma, and metastases. Cystic pancreatic lesions include true cysts, pseudocysts, and cystic neoplasms. Focal fluorodeoxyglucose (FDG) avidity within the pancreas is suspicious for focal pancreatic lesion. Obstruction of the pancreatic duct can result in pancreatic inflammation, such as pancreatitis, which…

When confronted with a focal splenic lesion, knowledge of the differential diagnosis for splenic masses is valuable ( Fig. 13.1 ). For malignancies of the spleen, lymphoma would be most common, whereas metastases are relatively uncommon and primary splenic malignancies are rare. Benign splenic lesions encountered on fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) are common and include infections, sarcoidosis, and splenic repopulation. Open full size…

Liver The segmental anatomy of the liver is based on the hepatic veins, thus the segmental anatomy of the liver is more difficult to appreciate on contrast computed tomography (CT). The liver is divided into right and left lobes by the middle hepatic vein. The right lobe is divided into anterior and posterior segments by the right hepatic vein, and the left lobe is divided into…

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The pleura are the pair of membranous linings surrounding the lungs. The visceral pleura covers each lung surface, and the parietal pleura covers the inner surface of the thoracic cavity. Normally, the visceral and parietal pleura oppose each other, have negligible material between them, and are so thin as to be nearly imperceptible on computed tomography (CT). Thus, if you can see the pleura between lung…

The lung is an organ where the integration of findings on 18F-fluorodeoxyglucose positron emission tomography (FDG PET), findings on computed tomography (CT), and the clinical scenario is particularly important to arrive at the best conclusions. Many FDG-avid lung lesions will be determined to be malignant or benign only after correlation with CT findings and the clinical history. Non-FDG-avid lung lesions may also be malignant and need…