Additive value of 320-section low-dose dynamic volume CT in relation to 3-T MRI for the preoperative evaluation of brain tumors.

Abstract

To assess whether 320-section low-dose dynamic volume computed tomography (320-LDVCT) with adaptive iterative dose reduction (AIDR) adds value to 3-T MRI for the preoperative evaluation of brain tumors. The study population was comprised of 16 consecutive patients with brain tumors who, in addition to preoperative 3-T MRI, underwent 320-LDVCT with AIDR. Two radiologists independently evaluated the CT and MRI studies; one measured the relative cerebral blood volume (rCBV) in the tumor and contralateral brain on CT and MR perfusion maps. Interobserver agreement was assessed by κ statistics. In 3 of 16 patients (19%), 320-LDVCT added diagnostic value to 3-T MRI studies with respect to the visualization of feeders (κ=0.77), and in 12 (75%) it helped the delineation of venous structures (κ=0.71) and the relationship between the tumor and adjacent vessels (κ=0.85). The average standardized rCBV value was 12.2±2.40 (range 0.7-36.6) on MR and 8.80±2.77 (range 0.8-38.0) on CT perfusion studies; the correlation between these values was very strong (r=0.92, p<0.0001). According to the neurosurgeons, 320-LDVCT added helpful information for surgery in 4 patients (25%). The 320-LDVCT can add value to 3-T MRI for the tumor feeders and relationship between the tumor and adjacent vessels.