technetium-tc-99m-exametazime and Carotid-Artery-Diseases

This study was conducted to show the reliability of fully automated quantification of regional cerebral blood flow (rCBF) in balloon occlusion test (BOT) of the internal carotid artery (ICA). We also shows the usefulness of ratio of rCBF during BOT to rCBF at rest (BOT/rest ratio = rCBF during BOT/rCBF at rest) rather than asymmetry index (AI) during BOT (AI = occluded-side rCBF/contralateral rCBF).. In the last 2 years, we performed the BOT on 10 consecutive patients (4 with intracranial aneurysms and 6 with head and neck tumors). During the BOT, mean stump pressure (MSTP) of the ICA was monitored. We measured cerebral blood flow (CBF) with technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography at rest and during BOT. rCBF was determined using 3-dimensional stereotaxic region of interest template (3DSRT) which automatically divided CBF into 12 segments. We defined hypoperfusion segment as BOT/rest ratio <0.9 or AI <0.9.. When the BOT/rest ratio was used as a hypoperfusion parameter, the number of hypoperfusion segments was significantly greater in patients with an MSTP ≤50 mm Hg than in patients with an MSTP >50 mm Hg. However, only AI during BOT did not reflect MSTP significantly.. The evaluation of CBF changes in BOT using 3DSRT and the BOT/rest ratio were useful because of objective comparison.

Topics: Adult; Aged; Automation; Balloon Occlusion; Carotid Artery Diseases; Carotid Artery, Internal; Cerebrovascular Circulation; Diagnostic Techniques, Cardiovascular; Female; Hemodynamics; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Intracranial Aneurysm; Male; Middle Aged; Multimodal Imaging; Neoplasm Invasiveness; Positron-Emission Tomography; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed

An objective and practicable method to evaluate the brain tolerance to unilateral carotid artery occlusion was attempted. Ten consecutive cases were studied. Endovascular trial balloon occlusion of the unilateral carotid artery in conjunction with single-photon emission computed tomography (SPECT) as well as digital subtraction angiography (DSA) and clinical neurological evaluation was routinely performed for those patients who might undergo permanent occlusion of the internal (ICA) and/or common carotid artery (CCA). The result of SPECT was analyzed semi-quantitatively and compared with the baseline data as well as the data from contralateral side. The relative symmetry index (rS) of side-to-side radioactivity counts relevant to the baseline was calculated. One subject failed the balloon occlusion test (BOT), even though an angiographically adequate collateral circulation was observed. The rS of the patient was 74.5%. The remaining patients passed the 45-min BOT without any neurological deficiency induced. Their value of rS was 97.8% +/- 4.4%. Based the BOT results, the left ICA, CCA and external carotid artery were excised in one patient, CCA-ICA reconstructions after carotid occlusions were performed in three. The carotid arteries were saved in five. For one patient, the ICA was occluded spontaneously during the BOT. There were no neurological impairments developed after the surgery. With this BOT technique, clinically silent areas of decreased perfusion might be detected. We suggest it be a routine preparatory to carotid manipulations.

Topics: Adult; Aged; Angiography, Digital Subtraction; Balloon Occlusion; Brain; Brain Diseases; Carotid Artery Diseases; Central Nervous System Neoplasms; Humans; Male; Middle Aged; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Extensive experience and critical evaluation of the efficacy of a pharmacologic hypotensive challenge during conventional balloon test occlusion (BTO) of the internal carotid artery (ICA) is lacking. This prompted us to review our institution's most recent experience with this adjunctive provocative test before planned therapeutic balloon occlusion of the ICA.. Twenty consecutive cases of endovascular therapeutic balloon occlusion of the ICA were retrospectively reviewed. Conventional BTO under normotension and with hypotensive challenge were performed within a standardized protocol.. Sixteen patients underwent provocative testing, of which 13 had BTO with hypotensive challenge. All patients in this group tolerated these maneuvers without acute neurologic deficit. Two (15%) of these patients developed delayed permanent neurologic deficits, which seemed to be attributable to hemodynamic ischemia. One of seven patients not undergoing hypotensive challenge also developed transient neurologic deficits after carotid occlusion.. Despite the conceptually attractive and early positive experience of the hypotensive challenge in attempting to increase sensitivity and specificity of risk for developing delayed hemodynamic ischemia, we have found two significant false-negative results. This experience is reviewed in the context of risks of permanent balloon occlusion of the carotid artery after balloon test occlusion.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brain; Brain Ischemia; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebral Angiography; Child; Child, Preschool; Female; Humans; Intracranial Hypotension; Male; Middle Aged; Prognosis; Radiopharmaceuticals; Regional Blood Flow; Retrospective Studies; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

This paper describes abnormal brain perfusion unexpectedly demonstrated by Tc-99m MAA total-body imaging in two children with intracardiac right-to-left shunt (RLS) associated with complex congenital heart disease. One child was a 12-year-old girl with asplenia cardiac syndrome and multiple cerebral infarctions caused by thromboembolism in the internal carotid artery, and the other child was a 6-month-old boy who developed focal cerebral infarction following shunt operation. In both children, the total-body imaging depicted the brain due to RLS, where radioactivity decreased unilaterally in the cerebral hemisphere. In the first patient, radioactivity also decreased in the contralateral cerebellum, suggesting the crossed cerebellar diaschisis phenomenon. These abnormalities in brain perfusion were confirmed by Tc-99m HMPAO brain SPECT. Careful review of the distribution of the radiotracer in the depicted brain on Tc-99m MAA total-body imaging may provide important information regarding brain perfusion in some patients with a high risk of stroke complication associated with RLS.

Topics: Brain; Carotid Artery Diseases; Carotid Artery, Internal; Cerebellum; Cerebral Infarction; Child; Female; Functional Laterality; Heart Defects, Congenital; Humans; Infant; Lung; Male; Radiopharmaceuticals; Technetium Tc 99m Aggregated Albumin; Technetium Tc 99m Exametazime; Thromboembolism; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

To evaluate stroke risk assessment of balloon test occlusion of the internal carotid artery (ICA) with enlarged haemodynamic monitoring prior to permanent ICA occlusion.. 24 patients with cervical metastasis (n = 18), cavernous meningiomas (n = 3) or inoperable cavernous aneurysms (n = 3) were examined. The test occlusion was monitored by EEG, neurological examinations and transcranial Doppler sonography of the ipsilateral middle cerebral artery with evaluation of the cerebrovascular reserve capacity. Additionally 99mTc-HMPAO-SPECT imaging was added showing the perfusion during test occlusion.. In one (4%) patient the test occlusion had to be interrupted previously due to an acute neurological deficit. This patient and two (8%) patients with highly pathological test results in SPECT and TCD were excluded from permanent carotid occlusion. In 6 (25%) patients quantitative TCD monitoring could improve the stroke risk assessment by differentiating the patients in a low and high risk group. 6 (25%) patients were definitely occluded without haemodynamic complications, but two patients suffered from embolic infarctions which cannot be predicted by this procedure.. The multimodal balloon test occlusion with enlarged haemodynamic monitoring allows haemodynamic stroke risk assessment prior to permanent occlusion of the ICA.

Topics: Adult; Aged; Aged, 80 and over; Brain; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebral Infarction; Cerebrovascular Disorders; Contrast Media; Embolization, Therapeutic; Female; Head and Neck Neoplasms; Hemodynamics; Humans; Intracranial Aneurysm; Intracranial Embolism and Thrombosis; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Neurologic Examination; Organotechnetium Compounds; Oximes; Prognosis; Regional Blood Flow; Risk Factors; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Does the absolute value of the stump pressure (post-occlusion back pressure) become a useful index of a good collateral circulation? The authors continuously monitored the mean arterial pressure before, during and after 20-minute balloon test occlusion in 24 patients. The stump pressure was then compared with the results of 99mTc-hexa-methyl propyleneamine (99mTc-HMPAO) single photon emission computed tomography (SPECT) performed after 20 minutes of test occlusion. Patients who failed to tolerate even brief periods of carotid occlusion and showed asymmetric decreases in cerebral blood flow (CBF) on SPECT were divided into high and moderate risk groups. Those with no significant change in CBF on the occluded side formed the minimum risk group. Mean stump pressure was over 50 mmHg in three of a total of 13 patients in the high and moderate risk groups, and below 50 mmHg in two of the 11 patients in the minimum risk group. The ratios of the initial mean stump pressure to the pre-occlusion mean arterial pressure (%) and of the final mean stump pressure at the end of occlusion to the post-opening mean arterial pressure (%) did not exceed 58% in any patient in the high and moderate risk groups, and were at least 60% in all patients of the minimum risk group. Maintenance of a mean stump pressure of 60% or more of the mean systemic pressure during test occlusion may be a more useful index of a good collateral circulation than the absolute value of mean stump pressure.

Topics: Adult; Aged; Blood Pressure; Brain; Brain Ischemia; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebral Revascularization; Collateral Circulation; Dominance, Cerebral; Female; Humans; Intracranial Aneurysm; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Monitoring, Physiologic; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The prognostic value of single-photon emission computed tomography (SPECT) remains controversial. The aim of this study was to compare the prognostic value of stroke severity, stroke subtypes, and SPECT indices and to determine which predictive factors have an independent effect on clinical outcome.. We studied 55 consecutive patients with acute (< 12 hours) carotid infarct within 36 hours of symptom onset with SPECT. Clinical presentation was assessed by the Canadian Neurological Scale and stroke subtypes. SPECT indices were the degree and size of hypoperfusion and crossed cerebellar diaschisis as assessed by a semiquantitative analysis. Outcome was evaluated by the functional status and mortality (Rankin Scale score at 1 month).. The Rankin Scale score correlated with the degree (r = .580; P < .00001) and size (r = .616; P < .00001) of hypoperfusion. The mean degree and size of hypoperfusion were significantly higher in patients with poor outcome. Crossed cerebellar diaschisis had no significant predictive value. Statistical analysis determined threshold values for the Canadian Neurological Scale score and the degree and size of hypoperfusion for the functional status and mortality. The degree and size of hypoperfusion had no higher performance than the Canadian Neurological Scale score. The negative predictive value was excellent for both clinical and SPECT indices. Multivariate analysis selected only the size of hypoperfusion as an independent predictor for the functional status (P = .004) and the Canadian Neurological Scale score for mortality (P = .009).. SPECT performed within 36 hours of onset predicts clinical outcome, but different clinical and SPECT indices with threshold values should be chosen according to the relevant outcome end point.

Topics: Aged; Aged, 80 and over; Carotid Artery Diseases; Cerebrovascular Disorders; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Predictive Value of Tests; Prognosis; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The authors describe a patient with a large intracavernous aneurysm of the right internal carotid artery and a marked decrease in focal brain blood flow induced by temporary carotid balloon occlusion. The patient subsequently underwent a superficial temporal to middle cerebral artery bypass followed by successful carotid occlusion using detachable balloons placed proximal to the aneurysm. Postoperative rCBF demonstrated normal perfusion in the region of the right internal carotid artery distribution as well as normalization of perfusion to a previous area of baseline perfusion abnormality. Cerebral brain blood flow imaging was useful in the initial evaluation as well as the management of this patient.

Topics: Aged; Amphetamines; Brain; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebral Revascularization; Cerebrovascular Circulation; Collateral Circulation; Female; Humans; Intracranial Aneurysm; Iodine Radioisotopes; Iofetamine; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Seventeen of 19 patients (67 +/- 8 yr, 17 males and 2 females) had more than 75% unilateral stenosis or occlusion of the internal carotid or middle cerebral artery and two patients had carotid endarterectomy that previously had 90% stenosis of the internal carotid artery. They were studied during upright 99mTc-HMPAO brain SPECT. HMPA was injected immediately after arising from a supine position. Patients were classified into Group A (n = 10) with occlusion of the internal carotid or the middle cerebral artery or Group B (n = 9) with more than 75% unilateral stenosis of the internal carotid or the middle cerebral artery and with carotid endarterectomy. Additional cerebral blood flow perfusion abnormalities between upright and supine 99mTc-HMPAO brain SPECT were detected in seven patients in Group A and in only one patient in Group B. Semiquantitative analysis showed that the asymmetric ratios between upright and supine positions changed significantly in Group A from 0.82 +/- 0.15 to 0.89 +/- 0.10 (p < 0.01), but not in Group B, from 0.89 +/- 0.11 to 0.92 +/- 0.12 (ns). Additional perfusion abnormalities were relevant to occlusion of the internal carotid or middle cerebral artery indicated postural cerebral hypoperfusion. We conclude that upright 99mTc-HMPAO brain SPECT visualizes postural cerebral hypoperfusion possibly related to silent cerebral ischemia.

Topics: Aged; Brain; Carotid Artery Diseases; Carotid Artery, Internal; Cerebrovascular Circulation; Cerebrovascular Disorders; Constriction, Pathologic; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Posture; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Most symptoms and signs associated with a carotid cavernous fistula (CCF) are thought to be related to regurgitation of flow into cortical veins and to venous congestion. Arteriovenous shunting and secondary perfusion insufficiency is regarded as less important in causing symptoms. We describe a 27-yr-old male patient who had improvement of neurologic symptoms and signs after detachable balloon embolization of traumatic CCF. The pre- and postocclusion 99mTc-HMPAO brain SPECT scan showed improved cerebral blood flow after occlusion. The CCF had shown marked arteriovenous shunting without significant venous congestion on pre-occlusion cerebral angiogram. The postocclusion cerebral angiogram revealed complete occlusion of the CCF with increased blood flow in the ipsilateral middle cerebral artery distribution. These findings suggest that cerebral dysfunction may be related to perfusion insufficiency from the CCF. Brain SPECT scanning can assess the functional status of cerebral perfusion and may be a useful, noninvasive adjunct to angiography.

Topics: Adult; Arteriovenous Fistula; Carotid Artery Diseases; Carotid Artery, Internal; Cavernous Sinus; Embolization, Therapeutic; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Cerebral infarction following internal carotid artery occlusion results from either embolism or inadequate collateral blood flow. Although risk of embolism can be minimized, detecting compromised collateral circulation is more difficult. Cerebral angiography, carotid stump pressures and clinical evaluation during internal carotid artery occlusion are of limited utility. Xenon-133 radionuclide studies and stable xenon computed tomography are not readily available. We evaluated 99mTc-HMPAO SPECT, during temporary carotid artery occlusion, in 20 patients considered for internal carotid artery occlusion. Fourteen demonstrated symmetric cerebral perfusion during occlusion; eleven underwent transient and three had permanent carotid artery occlusion without complications. Five patients had ipsilateral globally decreased perfusion during temporary occlusion. One patient underwent transient occlusion of this vessel and one underwent carotid sacrifice without bypass grafting; both recovered without sequelae. The three remaining patients underwent carotid artery bypass grafting prior to sacrifice of this vessel. One patient with a small focal perfusion defect underwent carotid artery sacrifice without bypass grafting and developed acute neurologic deficits postoperatively. These initial results suggest that symmetric cerebral perfusion during temporary occlusion indicates that internal carotid artery occlusion will be tolerated. Although its implications are not yet well defined, the abnormal study identifies patients potentially at risk for postocclusion complications, thus providing a basis for neurosurgical management.

Topics: Adolescent; Adult; Aged; Arterial Occlusive Diseases; Brain; Carotid Artery Diseases; Carotid Artery, Internal; Cerebrovascular Circulation; Collateral Circulation; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

Single photon emission computed tomography with technetium-99m-d, l-hexamethylpropyleneamineoxime was used to assess variations in regional cerebral blood flow during temporary clipping in the course of intracranial aneurysm surgery and during the postoperative period in 20 patients, 14 of whom underwent temporary clipping. Of these 14 patients (Group A), 9 had aneurysms of the anterior communicating artery, 2 had aneurysms of the middle cerebral artery, and 3 had aneurysms of the carotid siphon. Temporary clips were applied, according to the site of the lesion, on A1, on the trunk of the middle cerebral artery, or on the trunk of the internal carotid artery. The occlusion time ranged from 2 to 31 minutes. The six patients who did not undergo temporary clipping served as controls (Group B), as follows: three had aneurysms of the posterior communicating artery, one of the anterior communicating artery, one of the middle cerebral artery, and one of the internal carotid artery. All patients were investigated with cerebral single photon emission computed tomography preoperatively, perioperatively, and postoperatively. In all the patients of Group A, the preliminary results of the study show a sharp fall in the perfusion of the territories of the temporarily clipped parent vessel and practically a complete recovery within 2 to 7 days of surgery, with no significant neurological symptoms. No similar disturbance of perfusion was found in the patients of Group B.

Topics: Adult; Aged; Brain; Brain Damage, Chronic; Brain Ischemia; Carotid Artery Diseases; Carotid Artery, Internal; Female; Humans; Intracranial Aneurysm; Intraoperative Complications; Male; Middle Aged; Monitoring, Intraoperative; Organotechnetium Compounds; Oximes; Postoperative Complications; Regional Blood Flow; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

The balloon occlusion test (BOT) of the internal carotid artery (ICA), combined with induced hypotension and cerebral blood flow (CBF) mapping, was carried out in three patients with a large or giant aneurysm of the ICA. Occlusion of the ICA for 10 minutes in the normotensive state was followed by 5 minutes of induced hypotension. During the last 2 minutes of hypotensive occlusion, technetium-99m-hexamethyl-propyleneamine oxime was administered to study the CBF. All patients tolerated the procedure well. One patient with moderate CBF reduction developed ischemic complications 24 hours after permanent ICA occlusion. Another showed no significant change in CBF and tolerated permanent ICA occlusion well, while the third refused permanent occlusion. The provocative BOT combined with CBF mapping is a promising predictor of complications of ICA occlusion secondary to perfusion abnormalities.

Topics: Aged; Algorithms; Aneurysm; Blood Pressure; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebral Infarction; Cerebrovascular Circulation; Female; Humans; Hypotension, Controlled; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Three patients with large carotid aneurysms were treated by parent artery occlusion with detachable balloons. Of these, 2 had intracavernous carotid artery aneurysms and one had a carotid-ophthalmic aneurysm. All patients underwent a formal balloon occlusion test and tolerated it well. One patient with a carotid-ophthalmic aneurysm, however, developed postoperative ischemic effects. This case was that of a 55 year-old female with right visual disturbance. Her middle cerebral artery flow had been compromised during test occlusion under induced hypotension. Although initially intact after balloon occlusion, she was found to be hemiplegic 24 hours later. She subsequently developed multiple small infarcts which were shown on MRI and which corresponded exactly to the previously demonstrated region of decreased flow during testing. This ischemic complication is possibly due to hypoperfusion, but embolism from the thrombosed aneurysm can not be denied. To prevent these complications, an extracranial-intracranial artery anastomosis prior to parent artery occlusion should be considered if the preoperative 99mTc-HMPAO SPECT shows a compromised cerebral blood flow. In addition to this, postoperative anticoagulant therapy should be given even if test occlusion was well tolerated clinically.

Topics: Brain Ischemia; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebrovascular Circulation; Female; Humans; Intracranial Aneurysm; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Sixty patients were studied for carotid artery disease and were further evaluated with hexamethyl-propyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) both at baseline (with the patient resting) and after administration of acetazolamide (ACZ). Of these 60 patients, 58 (97%) had symptoms and 49 (82%) had stenoses greater than 70% in at least one internal carotid vessel. Nine patients (15%) had symmetric findings on baseline examinations and at SPECT with ACZ. Thirty-two patients (53%) had asymmetric findings on baseline, but in 24 of these patients (75%) additional lesions were observed after ACZ administration. Nineteen patients (32%) had asymmetric findings only after ACZ was administered. HMPAO SPECT with ACZ allows detection of diminished cerebral perfusion reserve that is not found when HMPAO SPECT is performed with the patient at rest. This procedure helps provide an objective evaluation of the hemodynamic effects of carotid stenosis.

Topics: Acetazolamide; Adult; Aged; Aged, 80 and over; Arterial Occlusive Diseases; Carotid Artery Diseases; Cerebrovascular Circulation; Cerebrovascular Disorders; Female; Humans; Ischemic Attack, Transient; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A review of our 1 1/2 years' experience with transcranial Doppler sonography (TCD) is given. In total, 619 TCD examinations were performed. Considering physiological variations of blood flow velocities in the intracranial arteries, TCD findings in stenoses and occlusions of the extracranial and intracranial brain-supplying arteries as well as in intracranial vasospasms were evaluated. In patients with leptomeningeal anastomoses demonstrated by TCD in the region of the peripheral middle cerebral artery, the regional cerebral blood flow was measured by 99mTc-HMPAO-SPECT. The value and limitations of TCD in cerebrovascular diseases and the indications to TCD examination of the intracranial arteries are discussed.

Topics: Carotid Artery Diseases; Carotid Artery, External; Carotid Artery, Internal; Cerebrovascular Disorders; Constriction, Pathologic; Echoencephalography; Evaluation Studies as Topic; Humans; Organotechnetium Compounds; Oximes; Subclavian Steal Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Cerebral perfusion through stenosed internal carotid arteries is usually maintained by autoregulation. However, flow reserve may be reduced, suggesting hemodynamically significant stenosis, and such reduction should be improved by carotid endarterectomy. This concept was studied in 20 subjects with unilateral internal carotid artery stenosis (major stenosis greater than or equal to 70%, minor stenosis less than or equal to 50%). Thirteen had experienced recent transient ischemic attacks and seven had no definite focal symptoms. Subjects underwent Tc-HMPAO cerebral SPECT during acetazolamide dysautoregulation before and after internal carotid endarterectomy. Nine (45%) had perfusion defects that improved after surgery, suggesting surgery had improved cerebral flow reserve. Seven had defects that did not improve after surgery. Four had worsened or new defects after surgery, suggesting perioperative infarcts. The relatively large proportion of patients with improved cerebral blood flow reserve after surgery suggests that this technique may have a significant role to play in assessing which patients might benefit from carotid endarterectomy.

Topics: Aged; Arterial Occlusive Diseases; Carotid Artery Diseases; Carotid Artery, Internal; Cerebrovascular Circulation; Endarterectomy; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

Topics: Arterial Occlusive Diseases; Carotid Artery Diseases; Carotid Artery, Internal; Humans; Male; Middle Aged; Organometallic Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime