Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
Q: The purpose of this study was to investigate the relation between preoperative chronic cerebral ischemia and postoperative new cerebral ischemia in patients undergoing carotid endarterectomy (CEA).', 'We reviewed the diffusion weighted magnetic resonance images (DWI) of the 51 patients (37 men, mean age 68.88.4 years) undergoing isolated CEA in the preoperative and early postoperative period. The number, anatomic location and the size of new ischemic lesions were recorded.', 'In the preoperative period, 28 (54.9 %) patients were symptomatic. There was chronic cerebral infarction in the preoperative DWI images of 17 patients (33.3 %). In the postoperative period, there was newly developed cerebral ischemia in postoperative DWI images of eight (15.7 %) patients. Six of the eight patients with newly developed cerebral ischemia had chronic cerebral infarction in their preoperative DWI images. The incidence of newly developed cerebral ischemia after CEA in patients with preoperative chronic cerebral ischemia was significantly higher than the incidence in patients without preoperative chronic cerebral ischemia (p=0.01).
A:
Is previous chronic cerebral infarction predictive for new cerebral ischemia after carotid endarterectomy?