Korean J Radiol.  2014 Aug;15(4):530-533. 10.3348/kjr.2014.15.4.530.

Hot-Clot Artifacts in the Lung Parenchyma on F-18 Fluorodeoxyglucose Positron Emission Tomography/CT due to Faulty Injection Techniques: Two Case Reports

• Ozdemir E
• Poyraz NY
• Keskin M
• Kandemir Z
• Turkolmez

• KMID: 1731058
• DOI: http://doi.org/10.3348/kjr.2014.15.4.530

Abstract

F-18-fluorodeoxyglucose (FDG) positron emission tomography/CT is an important whole-body imaging tool in the oncology and widely utilized to stage and restage various malignancies. The findings of significant focal accumulation of FDG in the lung parenchyma in the absence of corresponding CT abnormalities are related to the lung microembolism and known as hot-clot artifacts. Herein we present two cases with focal FDG uptake in the lung parenchyma with no structural lesions on the CT scan and discuss the possible mechanisms.

Keyword

FDG PET/CT; Microembolism; False positive

MeSH Terms

*Artifacts
False Positive Reactions
Female
Fluorodeoxyglucose F18/*administration & dosage/diagnostic use/pharmacokinetics
Humans
Lung/metabolism/radiography/*radionuclide imaging
Male
Middle Aged
Multimodal Imaging/methods
Positron-Emission Tomography/*methods
Pulmonary Embolism/radiography/*radionuclide imaging
Radiopharmaceuticals/*administration & dosage/diagnostic use/pharmacokinetics
Tomography, X-Ray Computed/methods
Young Adult
Fluorodeoxyglucose F18
Radiopharmaceuticals

Figure

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  Fig. 1 Positron emission tomography (PET), CT, and fusion PET/CT axial slices of case 1. There is focal FDG accumulation in right upper lobe without anatomical correlate on CT. SUV-max: 28.8. PET/CT was repeated 24 hours later and focal FDG uptake in right lung was resolved. FDG = fluorodeoxyglucose, SUV-max = maximum standardized uptake value

• 

  Fig. 2 Positron emission tomography (PET), CT, and fusion PET/CT axial slices of case 2. FDG accumulation in superior segment of left lower lobe without anatomic correlate on CT. SUV-max was 17.7. PET/CT of case 2 repeated 24 hours later showed no FDG accumulation in left lower lobe. FDG = fluorodeoxyglucose, SUV-max = maximum standardized uptake value

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