基于Ct评估也许有助于选择卒中的治疗方法
WESTPORT, CT (Reuters Health) - Computed tomography (CT) angiography or xenon-enhanced CT cerebral blood flow measurements in conjunction with standard CT may enhance treatment decisions for patients who present with stroke, University of Pittsburgh researchers report.
Between 1997 and 2000, Dr. Howard Yonas and associates conducted all three types of examinations on 51 patients who presented within 24 hours of stroke symptom onset.
, 百拇医药 As reported in the November issue of Stroke, 24 of 31 patients who presented within 6 hours had no infarction on the initial CT scan. Among these 24, one of 13 patients with normal cerebral blood flow based on xenon-enhanced CT exhibited evidence of infarction on a follow-up CT. By comparison, six of 11 with compromised blood flow had a new infarction (p = 0.023).
Similarly, patients with open carotid and cerebral arteries on CT angiography were less likely to experience new infarctions than those with occluded arteries (p = 0.008).
, 百拇医药
"Patients with reversible (7 to 29 mL/100 g per minute) cerebral blood flow and no initial infarction are theoretically most likely to benefit from the effects of successful thrombolytic therapy," the investigators write. Patients with normal blood flow are unlikely to benefit, they add, and in fact such therapy would increase their risk of bleeding complications and hemorrhage.
"Most important is the ability to distinguish a group of patients with open middle cerebral artery but reversible... low flow, which is presumably due to distal branch occlusion that should be most amenable to intravenous thrombolytic therapy," the researchers add.
, http://www.100md.com
"I can't imagine any reason to not recommend doing all three tests when patients present," Dr. Yonas told Reuters Health. "If you're talking about the cost of doing all three compared to a CT scan alone, the patient is already on the CT table. Each test involves some cost, but probably all three together are still less expensive than most complex MRI examinations."
"Our challenge is to extend the window for treatment beyond 3 hours, and to make the therapy more effective even before 3 hours," he continued.
, 百拇医药
Tissue plasminogen activator (tPA) therapy should not be used even before 3 hours if there is no blood flow and the area involved is already dead, he said. On the other hand, "We had patients out to almost 24 hours who had a blocked artery, low flow, but not less than 10 mL/100 g per minute, and the CT scan hadn't converted yet," Dr. Yonas pointed out. "We know if you let people stay in that state, they will have a big stroke."
Such patients, he said, would be ideal candidates for attempting tPA therapy beyond the 3-hour window, perhaps even as late as 24 hours after symptom onset., 百拇医药
Between 1997 and 2000, Dr. Howard Yonas and associates conducted all three types of examinations on 51 patients who presented within 24 hours of stroke symptom onset.
, 百拇医药 As reported in the November issue of Stroke, 24 of 31 patients who presented within 6 hours had no infarction on the initial CT scan. Among these 24, one of 13 patients with normal cerebral blood flow based on xenon-enhanced CT exhibited evidence of infarction on a follow-up CT. By comparison, six of 11 with compromised blood flow had a new infarction (p = 0.023).
Similarly, patients with open carotid and cerebral arteries on CT angiography were less likely to experience new infarctions than those with occluded arteries (p = 0.008).
, 百拇医药
"Patients with reversible (7 to 29 mL/100 g per minute) cerebral blood flow and no initial infarction are theoretically most likely to benefit from the effects of successful thrombolytic therapy," the investigators write. Patients with normal blood flow are unlikely to benefit, they add, and in fact such therapy would increase their risk of bleeding complications and hemorrhage.
"Most important is the ability to distinguish a group of patients with open middle cerebral artery but reversible... low flow, which is presumably due to distal branch occlusion that should be most amenable to intravenous thrombolytic therapy," the researchers add.
, http://www.100md.com
"I can't imagine any reason to not recommend doing all three tests when patients present," Dr. Yonas told Reuters Health. "If you're talking about the cost of doing all three compared to a CT scan alone, the patient is already on the CT table. Each test involves some cost, but probably all three together are still less expensive than most complex MRI examinations."
"Our challenge is to extend the window for treatment beyond 3 hours, and to make the therapy more effective even before 3 hours," he continued.
, 百拇医药
Tissue plasminogen activator (tPA) therapy should not be used even before 3 hours if there is no blood flow and the area involved is already dead, he said. On the other hand, "We had patients out to almost 24 hours who had a blocked artery, low flow, but not less than 10 mL/100 g per minute, and the CT scan hadn't converted yet," Dr. Yonas pointed out. "We know if you let people stay in that state, they will have a big stroke."
Such patients, he said, would be ideal candidates for attempting tPA therapy beyond the 3-hour window, perhaps even as late as 24 hours after symptom onset., 百拇医药