Relation between FDG uptake and apparent diffusion coefficients in glioma and malignant lymphoma.
OBJECTIVE
This study evaluates the relation between 2-deoxy-2-[18F]fluoro-D: -glucose (FDG) uptake using positron emission tomography/CT and the apparent diffusion coefficient (ADC) in patients with glioma and malignant lymphoma.


METHODS
For 36 patients (30 with glioma and 6 with malignant lymphoma), the standardized uptake value (SUV) ratio was calculated to assess the FDG uptake. Pearson's correlation analysis was used to assess the relation between the SUV ratio and the ADC value: those of low-grade glioma and high-grade glioma were compared, as were those of glioblastoma and malignant lymphoma.


RESULTS
Inverse correlation between the SUV ratio and the minimum ADC was found for all cases (P < 0.0001, r = 0.68) and for glioma cases (P < 0.0001, r = 0.67). High-grade gliomas showed a significantly higher SUV ratio than low-grade gliomas did (P < 0.0001); they also showed significantly lower minimum ADC than low-grade gliomas did (P < 0.001). Cut-off values used for the SUV ratio of 0.9 and for the minimum ADC of 0.99 × 10(-3 )mm(2)/s were used to differentiate high-grade from low-grade gliomas, with high accuracy. Malignant lymphoma showed a significantly higher SUV ratio than glioblastoma (P < 0.0001). No significant difference in the ADC value was found between glioblastoma and malignant lymphoma (the minimum ADC: P = 0.13, the mean ADC: P = 0.084, respectively).


CONCLUSIONS
An inverse correlation was found between the SUV ratio and the minimum ADC in glioma and malignant lymphoma. The SUV ratio and the minimum ADC are useful to evaluate the grading of gliomas. The SUV ratio might be more useful for differentiating malignant lymphoma from glioblastoma than the ADC value is.
Department of Radiology, Mie University School of Medicine, Tsu, Mie, Japan. p-island@clin.medic.mie-u.ac.jp
Nobuyoshi
N
Matsushima
Masayuki
M
Maeda
Maki
M
Umino
Naohisa
N
Suzawa
Tomomi
T
Yamada
Kan
K
Takeda
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D002648:Child; D003937:Diagnosis, Differential; D004058:Diffusion; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D005910:Glioma / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008223:Lymphoma / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D060787:Neoplasm Grading; D015588:Observer Variation; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
D019788:Fluorodeoxyglucose F18