Value of 99Tcm-HL91 hypoxia imaging in identifying ischemic and hypoxic cells in law perfusion cerebral area

Jue FENG; Yaqing FENG; Yanzhu BIAN

ABSTRACT

BACKGROUND:

In the ischemic cerebral area there are viable tissues of low blood perfusion. Theses tissues can be rescued as long as blood supply is restored timely. As an imaging agent,99Tcm-HL91 can be used to demonstrate the viable cerebral tissues in hypoxic and ischemic area.

OBJECTIVE:

To investigate the value of 99Tcm-HL91 imaging in assessing ischemic stroke,in order to provide evidences for early intervention.

DESIGN:

An observational and controlled trial based on patients and healthy voluinteers.

SETTING:

A nuclear medicine department in a university and a neurological department and a nuclear medicine department in a provincial hospital.

PARTICIPANTS:

From March 2000 to September 2001,eighteen inpatients and outpatients suffering from ischemic cerebral diseases and 4 volunteers were enrolled in the study.

METHODS:

In the 18 patients,11 were clinically diagnosed as cerebral infarction,5 TIA,2 vertebrobasilar insufficiency. All the subjects underwent 99Tcm-HL91 cerebral hypoxia tomographic imaging. The labeled 99Tcm-HL91(555-1 110 MBq) was intravenously injected into the human body and imaging was conducted after 20 -30 minutes,17 patients underwent CT or MRI examination at the same time. Eleven patients underwent 99Tcm-ECD tomopraphic imaging on the next day. The results of the 3 examinations were compared with each other. The uptake in the inside and around-infarct areas was determined by direct visual observation on the images. Positive change was given by presence of increased uptake and negative by absence. The uptake change that could not be clearly defined as positive or negative was considered critical level. But the uptake on both hemispheres was compared with ROI technology. The change over 25% between hemispheres was set as positive and the other was negative. So there was no critical group in this study.MAIN OUTCOME

MEASURES:

The results of cerebral hypoxia imaging,CT,MRI and cerebral perfusion imaging.

RESULTS:

Among the 18 patients,5 were positive for hypoxia imaging(4infarction and 1 vertebrobasilar insufficiency). In the 99Tcm-ECD perfusion,6out of 11 patients manifested of regional decreased blood perfusion. Nine patients manifested of abnormal CT or MRI results. No abnormalities were detected in the 4 volunteers.

CONCLUSION:

Although 99Tcm-HL91 imaging for diagnosis of cerebral ischemic disease is affected by many factors,it can identify whether the ischemic tissue is hypoxic or necrotic when the perfusion imaging demonstrate low flow. So it helps in guiding rehabilitation intervention and foretelling prognosis.