RadioGraphics 2010; 30:939-957
Masahiro Okafa, MD . Norihide Sato, MD, PhD , Kazunari Ishii, MD, PhD , Kaname Matsumura, MD, PhD , Makoto Hosono, MD, PhD Takamichi Murakami, MD, PhD
Malignant lymphoma is the most common form of hematologic can¬cer, yet because of advanced methods of assessment, the traditional histology-based classification of lymphoma is insufficient for under¬standing lymphoma imaging. Still, radiologists should be familiar with the imaging findings in lymphoma. Integrated positron emission tomography (PET)-computed tomography (CT) allows improved diagnostic accuracy, and uptake of 2- [fluorine-18] fluoro-2-deoxy-D-glucose (FDG) can help predict response during treatment. The sensi¬tivity and specificity of FDG PET are superior to those of gallium 67 scintigraphy in all but indolent lymphoma. Both magnetic resonance (MR) imaging and CT allow excellent assessment of bone texture, but FDG PET is superior in demonstrating bone marrow metabolic activity. Thus, FDG PET is important in both the primary diagnosis and the evaluation of therapy in lymphoma. It may be difficult to de¬termine whether residual abnormalities seen after the completion of chemotherapy-radiation therapy represent residual tumor or fibrotic tissue, but PET/CT may allow more accurate diagnosis than MR im¬aging or CT, thereby helping identify patients who require more inten¬sive treatment. Some diagnostic pitfalls are encountered at FDG PET. However, anatomic CT helps localize and define disease and avoid these potential pitfalls.