Enzhong Li MD, PhD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: To differentiate penumbra from infarct in the acute stroke especially hyperacute stroke, to evaluate the curative efficacy and to observe the relationship between the onset time and prognosis by the techniques of the DWI and PWI. Methods and Materials: 120 patients who were doubted to suffer from acute stroke were selected and scanned by 1.5 Tesla superconductive MRI Scanners (GE, Milwaukee, USA; Siemens, Erlangen, Germany). Their ages ranged 28 to 86 years with an average age of 64. Among them there were 21 cases in hyperacute stage (within 6 hours), 65 patients in acute stage (Between 6 to 48) and 34 without any infarct who were confirmed to have the transient ischemic attack (TIA) during the 48 hours clinical observation. The T1-weighted and T2-weighted images were obtained with SE (spin echo) and FSE (fast spin echo) pulse sequences and DWI was performed using a single shot EPI (echo planar imaging) pulse sequence with b-value 1000 sec/mm2, and PWI using EPI pulse sequence and dynamic first pass bolus tracking of Gd-DTPA. Data analysis was done with "3D Med analysis" software, which was developed by Medical Image Processing Group, Institute of Automation, the Chinese Academy of Sciences. Results: In hyperacute stage, 2 patients were examined in 1.5 hour and after medical treatment, they were recovered completely. The abnormal signal in DWI was penumbra, and gradually faded away with the therapy we gave; 8 were in hospital within 3 hours and after the therapy, we found that the abnormal signal in DWI was partly penumbra which was around the infarct core; There were 11 cases with stroke within 6 hours and the abnormal signal in DWI was almost all infarct. In PWI, we found the abnormal areas were generally larger that that in DWI, although there was no obvious abnormal signal area found in some cases. In acute stage, totally 65 patients were examined, there were still various penumbrae through the DWI-PWI mismatch, and after the therapy, the mismatch areas were reduced or fade away gradually. Besides, we observed that 34 cases who were without any infarct during the 48 hours clinical observation and following MRI examination, that is, they suffered from TIA. Conclusion: It was not accurate to say that DWI-PWI mismatch was penumbra, because the abnormal areas in DWI also included the penumbra. It depended on the onset time. Besides, DWI and PWI are very effective tools to diagnose hyperacute stroke, to differentiate penumbra from infarct, and to evaluate the therapeutic efficacy.       Questions about this event email: tian@doctor.com

Li MD, PhD, E, Infarct or Penumbra? A Combined DWI and PWI Study.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3101394.html