title: Apparent diffusion coefficient in the evaluation of cerebral gliomas malignancy.
abstract: OBJECTIVE
  Magnetic resonance imaging (MRI) is a key modality not only for lesion diagnosis, but also to evaluate the extension, type and grade of the tumor. Advanced MRI techniques provide physiologic information that complements the anatomic information available from conventional MRI. The aim of this study was to determine whether there is a correlation between apparent diffusion coefficient (ADC) maps of intracranial glial tumors and histopathologic findings and whether ADCs can reliably distinguish low-grade from high-grade gliomas.
  
  
  METHODS
  This retrospective study included 25 patients with MRI examination up to seven days before surgery, according to the standard protocol with the following sequences: T1WI, T2WI, FLAIR, DWI and post contrast T1WI. Data obtained from DW MRI were presented by measuring the value of ADC. The ADC map was determined by utilizing Diffusion-Perfusion (DP) Tools software. All the patients underwent surgical resection of the tumor. Histological diagnosis of tumors was determined according to the World Health Organization (WHO) classification. The ADC values were compared with the histopathologic findings according to the WHO criteria.
  
  
  RESULTS
  The ADC values of astrocytomas grades I (0.000614 +/- 0.000032 mm2/s) were significantly higher (< 0.001) than the ADC values of anaplastic astrocytomas (0.000436 +/- 0.000016 mm2/s) and the ADC values of glioblastomas multiforme (0.000070 +/- 0.000008 mm2/s). The ADC values of astrocytomas grades II (0.000530 +/- 0.000114 mm2/s) were significantly higher (< 0.001) than the ADC values of anaplastic astrocytomas (0.000436 +/- 0.000016 mm2/s) and glioblastomas multiforme (0.000070 +/- 0.000008 mm2/s). The ADC values of anaplastic astrocy-omas (0.000436 +/- 0.000016 mm2/s) were significantly higher (< 0.001) than the ADC values of glioblastomas multiforme (0.000070 +/- 0.000008 mm2/s). The ADC values in the cystic part of the tumor for astrocytomas grades I (0.000775 +/- 0.000023 mm2/s) were significantly higher (< 0.001) than the ADC values of anaplastic astrocytomas (0.000119 +/- 0.000246 mm2/s) and glioblastomas multiforme (0.000076 +/- 0.000004 mm2/s). The ADC values astrocytomas grades II (0.000511 +/- 0.000421 mm2/s) were significantly higher (< 0.001) than the ADC values of glioblastomas multiforme (0.000076 +/- 0.000004 mm2/s).
  
  
  CONCLUSIONS
  DWI with calculation of ADC maps can be regarded as a reliable useful diagnostic tool, which indirectly reflects the proliferation and malignancy of gliomas. The ADCs maps can both predict the results of histopathological tumor and distinguish between low- and high-grade gliomas, and provide significant information for presurgical planning, treatment and prognosis for patients with high-grade astrocytomas.
authors.forename: Jelena
authors.initials: J
authors.lastname: Ignjatović
authors.forename: Dragan
authors.initials: D
authors.lastname: Stojanov
authors.forename: Vladimir
authors.initials: V
authors.lastname: Zivković
authors.forename: Srdjan
authors.initials: S
authors.lastname: Ljubisavljević
authors.forename: Nebojša
authors.initials: N
authors.lastname: Stojanović
authors.forename: Ivan
authors.initials: I
authors.lastname: Stefanović
authors.forename: Daniela
authors.initials: D
authors.lastname: Benedeto-Stojanović
authors.forename: Nebojša
authors.initials: N
authors.lastname: Ignjatović
authors.forename: Sladjana
authors.initials: S
authors.lastname: Petrović
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Aracki-Trenkić
authors.forename: Zoran
authors.initials: Z
authors.lastname: Radovanović
authors.forename: Lazar
authors.initials: L
authors.lastname: Lazović
mesh_terms: D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000145:classification / Q000473:pathology* / Q000601:surgery; D001932:Brain Neoplasms / Q000145:classification / Q000473:pathology* / Q000601:surgery; D049109:Cell Proliferation; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005909:Glioblastoma / Q000473:pathology / Q000601:surgery; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012984:Software; D055815:Young Adult