42 Majoie et al. Fig. 2. DSA images in a 37-year-old woman who developed progressive aphasia 1 day after coiling of a ruptured left internal carotid artery- tip aneurysm, despite optimal medical treatment.Transluminal balloon angioplasty was performed to treat the vasospasm. (A) Preangioplasty DSA demonstrates severe vasospasm in the M1 and M2 segments of left MCA. (B) Postangioplasty DSA shows return to normal caliber of the M1-segment of the left MCA. a cubital vein at a rate of 4 mL/second. At 7 seconds after initi- ation of the injection, a continuous scan was started with the following parameters: 80 kV, 100 mA (Sensation 4) or 90 kV, 120 mA (Mx8000), 4 × 5-mm collimation, 1 second per rotation for 46 seconds. The four 5-mm sections were reformatted into two 10-mm-thick sections. The overall dose required for PCT was 4.0–4.5 mSv. PCT data were analyzed with commercially available software developed by Wintermark et al. (14). Image- postprocessing involved placement of the region of interest (ROI) in an input artery (anterior cerebral artery) and an input vein (torcular herophili or superior sagittal sinus) and subse- quent generation of contrast-enhancement curves. The soft- ware generated color-coded cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) maps based on the CT time attenuation curves for each pixel. After large vessel removal, four circular ROIs of 1.5 cm in diameter were placed along the cortical mantle of each hemisphere in the middle cerebral artery (MCA) territory on the perfusion maps to generate quantitative data. CBF, CBV, and MTT values in the normal right hemisphere were compared with those of the affected left hemisphere. Unenhanced CT revealed a small left insular infarct. PCT showed areas of normal or decreased CBF and a large area of increased CBV and MTT in the MCA territory of the left hemi- sphere (Figure 1A–C), consistent with ischemia-related activa- tion of autoregulation. The mean value of cortical CBF mea- sured in the MCA territory of the right (normal) hemisphere was 77 mL per 100 g and per minute (range: 40–174). The mean value of cortical CBF in the left (affected) hemisphere was 31 mL per 100 g and per min (range: 13–38). The mean value of cortical CBV measured in the right (normal) hemisphere was 1.4 mL/100 g (range: 1.1–1.8). The mean value of cortical CBV in the left (affected) hemisphere was 4.7 mL/100 g (range 3.9– 6.0). The mean value of cortical MTT measured in the right (normal) hemisphere was 1.2 seconds (range 0.6–1.9). The mean value of cortical MTT in the left (affected) hemisphere was 9.6 seconds (range 6.7–19.0). On the same day as the PCT, angioplasty was performed under general anesthesia with full heparinization via a trans- femoral approach using an over the wire (Transend 0.010 in, Target Therapeutics/Boston Scientific, Boston, MA) silicone balloon microcatheter (Sentry, Target Therapeutics/Boston Scientific, Fremont, CA), according to a technique described previously (11,15). Before angioplasty, DSA showed severe vasospasm of the M1 segment of the left MCA and of the proximal left M2 segments (Figure 2A). After angioplasty of the M1 segment of the left MCA a good angiographic result was obtained (Figure 2B). In addition, 150 mg of papaverine Neurocritical Care ♦ Volume 6, 2007