sodium-pertechnetate-tc-99m and Carotid-Artery-Diseases

An extremely rare vascular complication, carotid artery aneurysm, developed 60 years after a torticollis operation. The patient's internal jugular vein was completely obstructed proximal to the subclavian vein. There was an associated incomplete obstruction of the ipsilateral common carotid artery on the right aspect of the neck--the site where resection of the whole sternocleidomastoid muscle had been performed when she was one year old. The patient had audible bruits over the right common carotid at the base of her neck but no signs of occlusive cerebrovascular disease. The diagnosis was made mainly with use of technetium radionuclide angiography. To the authors' knowledge, this is the first such report in the English or German literature.

Topics: Aneurysm; Carotid Artery Diseases; Female; Humans; Middle Aged; Postoperative Complications; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Torticollis

We implemented a technique for measuring regional cerebral blood volume using single-photon emission computed tomography and in vivo technetium-99m-labeled red blood cells and then evaluated it in nine normal human volunteers (controls) and seven patients with bilateral occlusion or severe stenosis of the internal carotid artery. We also measured regional cerebral blood flow using single-photon emission computed tomography and intravenous xenon-133 in the same subjects. We studied regional cerebral blood flow, regional cerebral blood volume, and their ratio before and after the intravenous injection of 1 g acetazolamide. Mean +/- SD baseline regional cerebral blood volume was higher in the patients than in the controls (4.1 +/- 0.6 versus 3.2 +/- 0.3 ml/100 g, p less than 0.01), and mean +/- SD baseline regional cerebral blood flow was lower in the patients than in the controls (40.5 +/- 11 versus 55.6 +/- 11 ml/100 g/min, p less than 0.05). Acetazolamide induced similar mean +/- SD increases in regional cerebral blood volume in both the controls and the patients (0.3 +/- 0.1 and 0.3 +/- 0.2 ml/100 g), while the mean +/- SD regional cerebral blood flow reactivity was significantly less in the patients than in the controls (12.6 +/- 7.6 versus 24.5 +/- 9.6 ml/100 g/min, p less than 0.05). Our study shows that single-photon emission computed tomography can provide quantitative estimates of both regional cerebral blood volume and regional cerebral blood flow in humans.

Topics: Acetazolamide; Aged; Carotid Artery Diseases; Carotid Artery, Internal; Cerebrovascular Circulation; Female; Humans; Male; Middle Aged; Reference Values; Regional Blood Flow; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed

The results of an evaluation of the perfusion scintigraphy findings of 350 hospitalised neurological patients and 55 more strictly selected neurosurgical patients with cerebrovascular complaints, revealed an accuraty of 83%, a sensitivity of 89%, and a specificity of 83%. The selection of the patients had no influence on the results as a whole. Compared with contrast-medium angiography, incorrect diagnosis must be expected in 17% of the cases. This includes erroneous negative findings in 10% of the cases. Grounds for misinterpretations are suggested, and the biological and methodological limitations of the method are set forth.

Topics: Brain Ischemia; Carotid Artery Diseases; Cerebrovascular Disorders; Humans; Intracranial Aneurysm; Radionuclide Angiography; Sodium Pertechnetate Tc 99m; Subarachnoid Hemorrhage

The assessment of the intracranial hemodynamic consequences of obstructive lesions of the carotid artery by measuring resting rCBF is inadequate because cerebral blood flow may remain constant in spite of significant drops in the intraluminal pressure due to autoregulation. Moreover, flow may be permanently decreased following cerebral infarction, even if the arterial anatomical conditions have resumed their normal state because of the decreased metabolic demand of an infarcted area. Measurement of the regional cerebral blood volume (rCBV) helps with the hemodynamic assessment of these conditions, since there is a linear and inverse relationship between intraarterial pressure and intracranial blood volume. In 24 patients exhibiting various carotid and ischemic brain lesions we studied both rCBF and rCBV. The latter is a comparative measure between hemispheres obtained by single photon emission tomography after autotransfusion of 99m Technetium labeled erythrocytes. There was no correlation between rCBF and clinical status, CT scan or arterial lesions. There was no correlation between rCBV and clinical status or CT scan. There was, however, an interesting correlation between rCBV and the severity of the arterial lesion. The rCBV was symmetrical in all patients with normal or moderately stenotic carotid arteries before and after operation. In some patients with severe unilateral stenosis or occlusion, there was a significant relative increase of rCBV in the hemisphere downstream from the lesion, which disappeared after surgery (endarterectomy or extra-intracranial bypass). In some patients with severe and bilateral carotid lesions, we noted an asymmetry in rCBV that disappeared after a unilateral operation. Other patients with similar lesions develop asymmetry only after an operation that resulted in a relative increase in rCBV in the hemisphere supplied by the non-operated artery. In conclusion analysis of these results suggests that in this series of patients, rCBV modifications were the consequence of cerebral autoregulation distal to the arterial lesions and provided satisfactory assessment of hemodynamic improvement after surgical repair.

Topics: Adult; Aged; Arterial Occlusive Diseases; Blood Volume; Carotid Artery Diseases; Carotid Artery, Internal; Cerebrovascular Circulation; Female; Humans; Male; Middle Aged; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed; Xenon Radioisotopes

Dynamic cerebral scintigraphy is a widely used, non-invasive procedure for the diagnosis of haemodynamic changes in the supra-aortic arterial territory. Eighty examinations have been carried out using a new method, which depends on demonstrating the time of arrival of the bolus within certain parameters. A definite advantage of the simultaneous demonstration of flow in various vascular territories is the fact that it is easily and rapidly perceived and that it is readily interpreted without depending on the subjective judgement of the operator. In addition, it is unnecessary to measure regions of interest.

Topics: Adult; Aged; Carotid Artery Diseases; Cerebral Infarction; Cerebrovascular Circulation; Cerebrovascular Disorders; Female; Humans; Male; Methods; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Subclavian Steal Syndrome

Topics: Adult; Arterial Occlusive Diseases; Carotid Artery Diseases; Carotid Artery, Internal; Cerebral Arterial Diseases; Female; Follow-Up Studies; Humans; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Topics: Carotid Arteries; Carotid Artery Diseases; Cerebrovascular Circulation; Collateral Circulation; Constriction; Constriction, Pathologic; Humans; Intracranial Aneurysm; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

The large elastic arteries, such as the carotids, pulsate (expand and contract) in synchrony with the heart beat. These pulsations should be reduced by significant stenosis. This hypothesis was studied in 15 men by obtaining sequential ECG-gated labeled blood-pool images of these vessels in anterior and lateral oblique views. These were computer processed by a functional program that displays each pixel with an intensity proportional to its change in activity level during the cardiac cycle. Blank areas indicated lack of pulsation and were correlated with angiographic studies. The blank skip areas were present when there was 50% or greater narrowing in arterial diameter (94% sensitivity) but were not seen in patients with normal or minimally diseased vessels (25% or less narrowing). They were present inconsistently in the four vessels with 25 to 50% narrowing.

Topics: Aged; Angiography; Arterial Occlusive Diseases; Carotid Artery Diseases; Electrocardiography; Erythrocytes; Humans; Male; Middle Aged; Polyphosphates; Pulse; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Tin Polyphosphates

A general method is described for computation of blood flow from time-activity curves using intravenous injection of the non-diffusible radio-tracer technetium pertechnetate. A technique of recirculation correction is adopted which predicts the start and end of recirculation depending on the patient's heart rate. This method allows one to clearly separate the first transit from the following recirculation. A correction for bolus dispersion of the intravenously injected tracer is also used. The evaluation of cerebral dynamic perfusion studies in 126 unselected adult patients resulted in a normal CBF of 44.5 ml/min/100 g +/- 5% and a decreased CBF of less than 40 ml/min/100 g. The presented method was also applied for flow measurement on the neck vessels. A good correlation between values obtained from these regions and the corresponding cerebral hemispheres was found. The method was also tested in 40 patients with angiographically proven neck vessel stenosis and in 15 patients before and after surgery of carotid stenosis. The results prove that the haemodynamic relevance of carotid stenosis on cerebral blood flow can be quantified. The accuracy of the method is estimated better than 5% for cerebral blood flow values and better than 15% for blood flow values gained over the neck vessel regions.

Topics: Adult; Aged; Carotid Artery Diseases; Cerebrovascular Circulation; Female; Heart Rate; Humans; Male; Mathematics; Middle Aged; Sodium Pertechnetate Tc 99m; Technetium

Topics: Carotid Artery Diseases; Carotid Artery Thrombosis; Carotid Artery, Internal; Cerebral Angiography; Cerebral Hemorrhage; Cerebrovascular Disorders; Female; Humans; Male; Middle Aged; Neck; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium