The added value of the apparent diffusion coefficient calculation to magnetic resonance imaging in the differentiation and grading of malignant brain tumors.
OBJECTIVE
ADC calculation can improve the diagnostic efficacy of MR imaging in brain tumor grading and differentiation.


METHODS
Apparent diffusion coefficient (ADC) values and ratios of 33 low-grade (23 astrocytomas, 10 oligodendrogliomas) and 40 high-grade (25 metastases and 15 high-grade astrocytomas) malignant tumors were prospectively evaluated.


RESULTS
Tumoral ADC values (r=-0.738, P <0.000) and ratios (r=-0.746, P < 0.000) were well correlated with higher degree of malignancy and quite effective in grading of malignant brain tumors (P < 0.000). By using cutoff values of 0.99 for tumoral ADC value and 1.22 for normalized ADC ratio, the sensitivity of MR imaging could be increased from 72.22% to 93.75% and 90.63%, the specificity from 81.08% to 92.68% and 90.24%, PPV from 78.79% to 90.91% and 87.88%, and NPV from 75.00% to 95.00% and 92.50%, respectively.


CONCLUSIONS
ADC calculation was quite effective in grading of malignant brain tumors but not in differentiation of them and added more information to conventional contrast-enhanced MR imaging.
Bulakbasi
Nail
N
Department of Radiology, Gulhane Military Medical Academy, Etlik, 06018 Ankara, Turkey. nbulak@gata.edu.tr
Guvenc
Inanc
I
Onguru
Onder
O
Erdogan
Ersin
E
Tayfun
Cem
C
Ucoz
Taner
T
D000293:Adolescent; D000328:Adult; D001254:Astrocytoma / Q000175:diagnosis / Q000473:pathology; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009837:Oligodendroglioma / Q000175:diagnosis / Q000473:pathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016037:Single-Blind Method
D003287:Contrast Media