title: PET-CT fusion imaging in differentiating physiologic from pathologic FDG uptake.
abstract: Interpretation of positron emission tomographic (PET) scans in the absence of correlative anatomic information can be challenging. PET-computed tomography (CT) fusion imaging is a novel multimodality technology that allows the correlation of findings from two concurrent imaging modalities in a comprehensive examination. CT demonstrates exquisite anatomic detail but does not provide functional information, whereas 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) PET reveals aspects of tumor function and allows metabolic measurements. Subtle findings at FDG PET that might otherwise be disregarded or interpreted as physiologic variants may lead to detection of a malignant process after being correlated with simultaneously acquired CT findings. Alternatively, equivocal CT findings, which could represent malignant tumor, reactive changes, or fibrosis, can be clarified with the help of the additional metabolic information provided by concurrent FDG PET. Accurate interpretation of FDG PET scans requires a thorough knowledge of the normal physiologic distribution of FDG and of normal variants that may reduce the accuracy of PET studies, thereby significantly affecting patient treatment. Although in rare instances PET-CT cannot help resolve the diagnostic dilemma, it is enjoying widespread acceptance in the medical imaging community, usually allowing differentiation of physiologic variants from juxtaposed or mimetic neoplastic lesions and more accurate tumor localization.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, New York Presbyterian Hospital, Weill Medical College of Cornell University, 525 E 68th St, Starr No 221, New York, NY 10021, USA. lak2005@med.cornell.edu
authors.forename: Lale
authors.initials: L
authors.lastname: Kostakoglu
authors.forename: Ruth
authors.initials: R
authors.lastname: Hardoff
authors.forename: Rosna
authors.initials: R
authors.lastname: Mirtcheva
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Goldsmith
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000032:analysis / Q000493:pharmacokinetics*; D006801:Humans; D007328:Insulin / Q000502:physiology; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging*; D009928:Organ Specificity; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000032:analysis / Q000493:pharmacokinetics*; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D007328:Insulin; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18