technetium-tc-99m-exametazime and Arteriosclerosis

To detect areas of cerebral perfusion from bypass arteries after vascular reconstruction, we administered selective intraarterial microsphere tracer into the external carotid arteries and determined (via single-photon emission computed tomography [IA-SPECT]) whether the distribution of radiotracer matched the arteriographic distribution of contrast material as shown on external carotid angiograms.. We compared the extent of regional distribution of tracer after external carotid artery injection of 20 to 40 MBq of 99mTc-HMPAO or 99mTc-ECD with that of contrast medium on the external carotid angiograms in 582 cortical regions in 12 patients with atherosclerotic occlusive disease and in 18 patients with moyamoya disease.. Marked accumulation of tracer was found only in the expected, specific, newly developed areas of cerebral perfusion from bypass arteries. The regional distribution of tracer corresponded to that of contrast medium in 523 regions (90%) and did not correspond in 59 regions (10%). Significant overestimation of the distribution of contrast material relative to that of tracer was observed in the patients with moyamoya disease.. SPECT showed slightly different distribution of tracer from that predicted by conventional angiography. IA-SPECT should enhance the analysis of newly developed areas of cerebral perfusion from the bypass arteries.

Topics: Adult; Arteriosclerosis; Carotid Arteries; Cerebral Angiography; Cerebral Arteries; Cerebral Revascularization; Cerebrovascular Circulation; Child; Cysteine; Female; Humans; Intracranial Arteriosclerosis; Male; Microspheres; Middle Aged; Moyamoya Disease; Organotechnetium Compounds; Postoperative Period; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The aim of our work was to study the state of regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) in patients with different degree of carotid stenosis after CE. Thirty six patients with carotid stenosis aged 46-65 years (mean age 55 years) were studied. In all the patients before and one month after carotid endarterectomy (CE) single photon emission computed tomography (SPECT) with 99mTc-hexamethylpropylene amine oxime (99mTc-HMPAO, Ceretec, Amersham) and SPECT with labelled in vivo 99mTc-red blood cells (99mTc-RBC) were carried out. According to the results of scintigraphic studies the regional cerebral blood flow (rCBF, ml/min/100g), the volume of hypoperfusion (Vhypoperf., sm3), the stroke volume (SV, sm3), the interhemispheric ratio of rCBF (IRrCBF) and the regional cerebral blood volume (rCBV, ml/100g) were calculated. CE leads to the bilateral increase of cerebral perfusion especially at the side of more expressed damage putting away interhemisphere asymmetry of rCBF. After CE the regression of SV and Vhypoperf were revealed. In asymptomatic disease patients with monolateral stenosis of carotid arteries rCBF reaches normal values and regions of hypoperfusion are not revealed. Surgical recanalization of carotid arteries causes expressed changes of scintigraphic parameters of rCBV: normalization of initially increased values of rCBV in patients with asymptomatic development of stenosed atherosclerosis of carotid arteries and subsequent increase of rCBV in comparison with preoperative level in patients who underwent acute stroke with neurological deficit and patients with poor clinical signs and multiple damage of both internal carotid arteries.

Topics: Acute Disease; Aged; Arteriosclerosis; Blood Volume; Brain; Brain Ischemia; Carotid Artery, Internal; Carotid Stenosis; Cerebrovascular Circulation; Cerebrovascular Disorders; Endarterectomy, Carotid; Erythrocytes; Female; Follow-Up Studies; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radiopharmaceuticals; Stroke Volume; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Percutaneous transluminal angioplasty (PCTA) is increasingly used to treat extracerebral arterial stenosis. The present study evaluates the safety and efficacy of PCTA treatment of symptomatic intracranial atherosclerotic stenosis.. A series of 22 vessels in 17 patients were treated with PCTA. All patients had recurrent neurological symptoms referable to the stenotic vessel despite optimal medical therapy. Critical (> 70%) arterial stenosis was confirmed by angiogram, and angioplasty was performed with a 3.0- to 3.5-mm Stealth balloon.. The average preangioplasty stenosis (North American Symptomatic Carotid Endarterectomy Trial criteria) was 72 +/- 8% (mean +/- SD), with a significant improvement seen after angioplasty; the best angiographic stenosis (after healing of intimal injury, if any) was 43 +/- 24% (P < .001). Overall PCTA was successful in 82% of the vessels. There were two strokes during angioplasty for a 30-day morbidity rate of 9.1% per treated vessel and 11.7% per case. The other 15 patients were clinically evaluated at 3 and 6 months; all cases were without further events. Restenosis was evaluated in 8 patients (12 vessels) with an angiogram at 6 months showing further improvement compared with the initial post-PCTA stenosis (51 +/- 10% versus 37 +/- 21% [P = .05]).. PCTA may be a beneficial therapy in selected cases of symptomatic intracranial atherosclerotic stenosis. Further study using a randomized trial is needed.

Topics: Aged; Angioplasty, Balloon; Arteriosclerosis; Cerebral Angiography; Cerebrovascular Disorders; Constriction, Pathologic; Female; Follow-Up Studies; Humans; Intracranial Arteriosclerosis; Intraoperative Complications; Male; Middle Aged; Neurologic Examination; Organotechnetium Compounds; Oximes; Recurrence; Safety; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tunica Intima