gms | German Medical Science

Objective: The aim of the study was to prospectively assess perfusion deficits and infarct pattern due to vasospasm after subarachnoid hemorrhage with perfusion weighted MRI in combination with digital subtraction angiography (DSA).

Methods: We included 106 patients from Jan 2002 to March 2006 with aneurysmal SAH and a high level of clinical suspicion for vasospasm all of whom had MR imaging including T2-, T2*-, FLAIR-, diffusion-weighted, and perfusion-weighted sequences, as well as DSA. Time to peak was measured by MRI in all major vessel territories and relative perfusion deficits were quantified as well as arteriolar diameters and circulation times in DSA.

Results: Cerebral vasospasm (VS), i.e. proximal, and/or peripheral, was found in 74% of patients with a rate of 31% for angiographic VS only, but an incidence of 43% of ischemic DWI-lesions on MRI in conjunction with angiographic VS. Circulation times (perfusion deficits) were 3.74±0.34sec in patients without VS, 4.11±0.92sec (0.98±0.44sec) with mild VS (11-33% arteriolar narrowing), 4.72±0.6sec (1.26±1.43sec) with moderate VS (34-66%) and 8.47±2.25sec (6.52±4.75sec) with severe VS (67-100%). DWI lesions could be classified as hemodynamic (26%), territorial (47%), cortical (7%), or affecting perforating vessels (20%). Infarcts were found in 5% of patients with mild VS, in 24% with moderate VS and in 71% with severe VS.

Conclusions: For a large group of patients it is shown with a combination of DSA and MRI that symptomatic VS, i.e. arteriolar narrowing and infarcts, result in different patterns of infarction after SAH. The findings inidcate that the complete arteriolar system from the basal arteries up to intraparenchymal vessels are affected. Perfusion weighted imaging with the ability to quantify perfusion deficits before infarction occurs in combination with DSA are a powerful means of managing VS including the indication for invasive treatment options like balloon-angioplasty.