Role of diffusion- and perfusion-weighted MR imaging for brain tumour characterisation.
OBJECTIVE
This study was undertaken to correlate apparent diffusion coefficient (ADC) and relative regional cerebral blood volume (rrCBV) to histological findings in a large series of patients with primary or secondary brain tumours to evaluate diffusion-weighted (DWI) and perfusion-weighted (PWI) imaging in the characterisation of cerebral tumors.


METHODS
Ninety-eight patients with cerebral tumours, 46 of which were primary (seven grade 0-I, nine low-grade gliomas, two gliomatosis cerebri, nine lymphomas and 19 high-grade gliomas) and 52 secondary, underwent conventional magnetic resonance (MR) imaging completed with DWI and dynamic contrast susceptibility PWI. Both ADC and rrCBV were calculated on a workstation by using Functool 2 software. Student's t test was used to determine any statistically significant differences in the ADC and rrCBV values.


RESULTS
Seventeen of 98 tumours were cystic or necrotic (12/17 hypointense and 5/17 hyperintense on DWI); the ADC value of hyperintense cystic areas was 0.97+/-0.23x10(-3) mm2/s. The ADC value of solid tumours varied between 0.64 and 3.5x10(-3) mm2/s. The rrCBV value was 1.4 (sigma 0.66) in low-grade gliomas; 1.22 (sigma 0.25) in lymphomas; 4.5 (sigma 0.85) in grade III gliomas; 3.18 (sigma 1.26) in grade IV gliomas and 2.53 (sigma 1.6) in metastases.


CONCLUSIONS
DWI has an important role in the differential diagnosis of cystic cerebral masses but not in tumour characterisation. PWI is helpful in differentiating high-from low-grade gliomas and lymphomas from high-grade gliomas.
Istituto di Radiologia Università di Torino Sede San Luigi, Orbassano, Italy. lrizzo@sirm.org
L
L
Rizzo
S Greco
SG
Crasto
P Garcia
PG
Moruno
P
P
Cassoni
R
R
Rudà
R
R
Boccaletti
M
M
Brosio
R
R
De Lucchi
C
C
Fava
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity