FDG PET-CT of gynecologic cancers: pearls and pitfalls.

FDG PET-CT plays an important role in treatment planning and in prognosis assessment of gynecologic cancer patients. Detection of hypermetabolic tissue with FDG PET, when combined with the high spatial resolution of CT, results in improved cancer detection and localization not afforded by either modality independently. This article is a primer for a radiologist performing PET-CT on gynecologic cancer patients and includes the imaging protocol, normal pattern of FDG distribution in the female pelvis and the lymph node drainage pathways from the gynecologic organs. Clinically relevant imaging findings that should be included in the report are discussed. Case examples illustrate how potential errors in exam interpretation can be avoided by concurrently performing a high-quality diagnostic CT with the FDG PET scan and by analyzing both the stand-alone and the fusion images.

Imaging findings in eating disorders.

OBJECTIVE: Eating disorders, such as anorexia nervosa and bulimia nervosa, are often undiagnosed but potentially treatable illnesses that, if not identified, can lead to morbidity and death. Often, because of embarrassment or social stigma, patients do not readily admit to these disorders when interviewed by caregivers. Imaging findings can suggest the presence of an eating disorder; understanding these findings allows the radiologist to contribute to the diagnosis of these insidious conditions and alert the referring caregiver. Current concepts in eating disorders and their multimodality imaging findings in several organ systems will be reviewed. CONCLUSION: After reviewing this article, the radiologist will understand the imaging findings in eating disorders. This knowledge will empower the radiologist to raise the question of a patient's eating disorder, a condition that may be unsuspected by the referring caregiver and could otherwise remain undiagnosed.

A DNA prism for high-speed continuous fractionation of large DNA molecules.

The analysis and fractionation of large DNA molecules plays a key role in many genome projects. The standard method, pulsed-field gel electrophoresis (PFGE), is slow, with running times ranging from 10 hours to more than 200 hours. In this report, we describe a thumbnail-sized device that sorts large DNA fragments (61-209 kilobases (kb)) in 15 seconds, with a resolution of approximately 13%. An array of micron-scale posts serves as the sieving matrix, and integrated microfluidic channels spatially shape the electric fields over the matrix. Asymmetric pulsed fields are applied for continuous-flow operation, which sorts DNA molecules in different directions according to their molecular masses, much as a prism deflects light of different wavelengths at different angles. We demonstrate the robustness of the device by using it to separate large DNA inserts prepared from bacterial artificial chromosomes, a widely used DNA source for most genomics projects.