Single photon emission computed tomography dual isotope myocardial perfusion imaging in women with systemic lupus erythematosus. II. Predictive factors for perfusion abnormalities

OBJECTIVE: We have reported that 40% of patients with systemic lupus erythematosus (SLE) had abnormal myocardial perfusion studies. Here we investigated risk factors for abnormal myocardial perfusion in a cohort of women with SLE without history of coronary artery disease. METHODS: Consecutive women with SLE followed at a large lupus clinic underwent single photon emission computed tomography dual isotope myocardial perfusion imaging (DIMPI) following pharmacological stress using dipyridamole. At the time of study each patient had a clinical and laboratory assessment performed by a standard protocol. We compared traditional risk factors as well as disease and therapy related factors in those with and without perfusion abnormalities. RESULTS: A total of 129 patients were studied. The mean +/- SD age was 44.8 +/- 10.9 yrs, and mean SLE Disease Activity Index was 4.2 +/- 5.1. Forty-nine (38%) patients had an abnormality of myocardial perfusion. Factors associated with an abnormal DIMPI included current hypertension (OR 2.11, p = 0.05), elevated cholesterol ever (OR 2.51, p < 0.05), and total cholesterol:high density lipoprotein-cholesterol ratio (OR 1.96 for each increase of 1.0, p < 0.008). CONCLUSION: Myocardial perfusion abnormalities are common in women with SLE without known coronary artery disease (CAD), suggesting a high burden of subclinical CAD. Several metabolic and therapy related factors appear to be associated with the process of atherogenesis in SLE. These results suggest that SLE should be considered a predisposing factor for atherosclerosis.     

Single photon emission computed tomography of technetium-99m tetrofosmin myocardial perfusion imaging in patients with systemic lupus erythematosus--a preliminary report

The purpose of this study was to evaluate the utility of single-photon emission computed tomography (SPECT) of technetium-99m tetrofosmin (Tc-99m TF) myocardial perfusion imaging to detect myocardial involvement in patients with systemic lupus erythematosus (SLE). Three groups of subjects-group 1: 25 SLE female patients with non-specific cardiac symptoms and signs, group 2: 25 female SLE patients without any cardiac symptoms and signs, and group 3: 25 female healthy controls-were evaluated by comparing rest and dipyridamole-stress Tc-99m TF myocardial perfusion SPECT. Tc-99m TF myocardial perfusion SPECT revealed perfusion defects in 88% and 40% of the cases in groups 1 and 2. respectively. However, no cases in group 3 demonstrated myocardial perfusion defects. Tc-99m TF myocardial perfusion SPECT is a useful noninvasive imaging modality to detect cardiac involvement in SLE patients with or without cardiac symptoms and signs.     

Cerebral imaging by magnetic resonance imaging and single photon emission computed tomography in systemic lupus erythematosus with central nervous system involvement

OBJECTIVE: To assess the significance of magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) abnormalities in patients with systemic lupus erythematosus (SLE). METHODS: Forty-four patients with SLE were retrospectively analysed. Patients were classified into three groups [1 and 2: patients with central nervous system (CNS) manifestations before and after starting high-dose steroid therapy, respectively; 3: patients without CNS manifestations. MRI was performed in all 44 patients and SPECT in 31. RESULTS: Abnormal findings in MRI were found in 19 patients. MRI abnormalities were significantly more frequent in patients with CNS manifestations than in those without [71 vs 17%, odds ratio (OR) 11.9, confidence interval (CI) 2.8-49.9, P=0.0003]. After the initiation of steroid therapy, patients with CNS manifestations also had an increased frequency of abnormal MRI. No correlation was found between SPECT findings and CNS manifestations. However, patients with CNS manifestations after starting steroids showed a markedly increased frequency of abnormal MRI and SPECT compared with those without CNS manifestations (80 vs 7%; OR 56, CI 4.4-719, P=0.0003). The positive predictive value of abnormality in both techniques in developing CNS manifestations after starting steroids was 89%. CONCLUSION: MRI findings correlated with CNS manifestations in SLE. Where there is a high suspicion of CNS involvement, the combination of MRI and SPECT may be useful in predicting CNS manifestations after starting steroid therapy.     

Single photon emission computed tomography perfusion imaging for assessment of myocardial viability and management of heart failure

In the setting of coronary artery disease, some areas of dysfunctional myocardium may realize significant improvement in function as a consequence of revascularization. These areas represent viable myocardium, encompassing a spectrum of pathophysiology ranging from chronic stunning, in which resting blood flow is preserved, to hibernating myocardium, in which resting blood flow is decreased. The accurate preoperative evaluation of viable myocardium helps identify those patients with left ventricular dysfunction who will most benefit from coronary revascularization. Of the various modalities available for viability assessment, the nuclear medicine techniques ²⁰¹Thallium and ¹⁸Fluorodeoxyglucose positron emission tomography have emerged as the most sensitive. It has been consistently shown that in patients with a significant amount of viable myocardium, there is a substantial survival benefit in revascularization versus medical therapy. The likelihood of affecting a significant improvement decreases with time to revascularization, however, particularly in the setting of an enlarged left ventricle secondary to ventricular remodeling.     

Migraine during systemic lupus erythematosus: findings from brain single photon emission computed tomography

OBJECTIVE: Headache in systemic lupus erythematosus (SLE) is controversial, as is evidence of brain impairment in patients with SLE and headache. Perfusion single photon emission computed tomography (SPECT) was performed to investigate brain impairment in SLE patients with migraine-like headache either from the period of diagnosis or later in the course of disease. METHODS: Eighteen patients with SLE (mean age 40.8 +/- 13.6 yrs) matching these characteristics underwent brain SPECT with 99mTc-HMPAO in the interictal period. Electroencephalography (EEG) and magnetic resonance imaging (MRI) were performed in 12 and 10 patients, respectively. SPECT was analyzed through visual and asymmetry combined analysis as well as by voxel-based statistical analysis compared to a control group of matched healthy subjects (statistical threshold: p = 0.01). RESULTS: Focal hypoperfusion was evidenced in 15 (83%) patients, often matching the main side of pain location, whereas EEG and MRI each gave a positive result in 50% of cases. Using voxel-based analysis, significant hypoperfusion was found in 8 (44%) patients, either lateralized to one side or localized to the anterior cingulate cortex, independent of pain location. CONCLUSION: Brain perfusion SPECT is a sensitive tool for identifying brain impairment in SLE-related migraine, although the mechanisms of brain damage remain to be elucidated. Besides confirming focal hypoperfusion in some patients, in 4 patients statistical analysis revealed interictal hypofunction of the anterior cingulate cortex, a key structure for cortical elaboration of pain in the midline network.     

Thallium-201 myocardial perfusion imaging in patients with systemic lupus erythematosus

The cardiovascular system is frequently affected in systemic lupus erythematosus (SLE). The observation of clinical manifestations related to the presence of coronary artery disease has not been frequently documented in young SLE patients. In these patients, the presence of inflammatory or thrombotic vascular lesions is often documented by anatomo-histological studies in the absence of previous clinical manifestations. The purpose of this study was to evaluate the presence of myocardial perfusion defects in SLE patients. The study was carried out in 15 patients without clinical signs of myocardial ischemia, 1 male and 14 females, 24 to 64 years old, with a mean SLE duration of 10.2 +/- 7.5 years. All the patients had normal blood pressure; electrocardiogram and Doppler-echocardiographic analysis showed values in the normal range. All the patients underwent thallium-201 exercise stress imaging repeated 3 hours later at rest, with tomographic SPECT analysis. Exercise test was carried out until submaximal load, without induction of ST segment alterations or symptoms. Scintigraphic scan showed normal thallium-201 SPECT imaging in 11/15 patients, while the other 4 patients had a slight perfusion defect, 3 of them in the inferior segment, in 2 non reversible and in 1 reversible; 1 patient had a non reversible defect in the septal segment. These slight perfusion defects, prevalently non reversible, may sometimes be a false positive imaging. Our results are in contrast with the literature observations concerning the frequent incidence of thallium-201 perfusion defects in SLE patients. In young asymptomatic SLE patients, our study does not report very important data indicating myocardial ischemia and suggesting the presence of significant coronary obstruction or vasculitis.     

单光子发射计算机断层扫描在系统性红斑狼疮中枢神经系统病变中的诊断价值

目的 评价单光子发射计算机断层扫描(single photon emission computed tomography，SPECT)在系统性红斑狼疮中枢神经系统病变(CNS-SLE)诊断中的应用价值。方法 对21例SLE患者进行SPECT检查，并由2名以上经过训练且不知晓患者病情的核医学医师进行独立读片，明确脑血流灌注异常部位。对10例CNS-SLE患者同时行头颅CT和，或核磁共振(MRI)检查。结果 10例CNS-SLE中9例头颅SPECT阳性(阳性率90％)，同时行头颅CT／MRI检查仅4例阳性(阳性率40％)。9例均为中～重度血流灌注减低，9例均有额叶和，或顶叶受累(6例额叶受累，4例顶叶受累，5例基底节受累，1例颞叶受累，0例枕叶受累，7例为多个区域受累)。对其中3例CNS-SLE患者治疗前后SPECT表现进行比较，发现经有效治疗临床症状改善后，SPECT异常随之明显改善甚至完全消失。11例非CNS-SLE中，仅2例SPECT阳性(阳性率18％)，且均为轻度单一区域血流灌注减低(1例枕叶，1例基底节)，无一例有额叶或顶叶受累。结论 SPECT对于CNS-SLE是一种敏感的检测手段，对监测病情变化、指导治疗有重要的参考价值；SLE患者头颅SPECT表现多发病灶、有额叶和(或)顶叶受累及中～重度血流灌注减低提示有CNS受累。     

Single-photon emission computed tomography myocardial perfusion imaging in patients with diabetes

Diabetes mellitus has reached epidemic proportions, creating a large population of people at increased risk for cardiac events. Single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) provides an effective tool to accurately diagnose and risk stratify patients with diabetes, similar to patients without diabetes. Diabetics, however, are at increased risk for coronary events. Diabetics with normal MPI have increased late cardiac events, and even those with mild perfusion defects have increased event rates compared with nondiabetics with similar perfusion abnormalities. Stress MPI can provide valuable risk stratification data for both sexes, with or without diabetes. However, diabetes appears to exert a greater relative impact in women than in men. Despite the absence of symptoms, the incidence and prevalence of coronary artery disease is increased in patients with diabetes. Further studies and research will be needed to define the eventual role of SPECT MPI in asymptomatic diabetics.     

Dipyridamole myocardial perfusion single photon emission computed tomography in patients with slow coronary flow

OBJECTIVE: Several studies have indicated that the velocity of contrast dye increases after intravenous dipyridamole infusion in patients with a slow-flow pattern (SFP). In this study we compared the results of coronary arteriography and exercise myocardial perfusion single photon emission computed tomography (SPECT) in patients with SFP. We also investigated the changes in myocardial perfusion in patients with abnormal exercise myocardial perfusion SPECT by using a pharmacological stress test with dipyridamole. DESIGN AND PATIENTS: This study included 60 patients who revealed SFP in their coronary arteriograms. Slow coronary flow diagnoses were made using the frame count method. A single day rest-exercise technetium-99m hexakis-2-methoxy-isobutyl isonitrile (Tc-99m MIBI; Du Pont Pharma SA, Belgium) SPECT was performed in all patients. Patients who had reversible perfusion defect (RPD) on the exercise SPECT were evaluated with dipyridamole myocardial perfusion scintigraphy.RESULTS Patients with SFP revealed both higher frame counts in native coronary arteries and higher mean frame counts. The coronary frame count was 26.4 +/- 3.5 in control patients and 64.40 +/- 16.64 in patients with SFP, respectively (P < 0.001). Exercise perfusion SPECT showed RPD in 17 patients (group 1), but was normal in 43 others (group 2). There were no statistically significant differences between groups 1 and 2 in frame counts. Myocardial perfusion was normalized in all 17 patients of group 1 after dipyridamole infusion. CONCLUSIONS: In patients with SFP perfusion, changes may improve with dipyridamole infusion. This study indicates that this improvement can be shown by dipyridamole SPECT. Furthermore, no correlation was observed between the time needed to fill a native coronary artery and RPD of the myocardium.     

Myocardial perfusion imaging with positron emission tomography and single photon emission computed tomography: frequency and causes of disparate results.

The purpose of this study was to compare rubidium-82 PET with thallium-201 SPECT imaging in 150 patients. Both techniques followed a single dipyridamole-handgrip stress, and images were displayed using the same 3-dimensional format and quantitative colour scale. Coronary arteriography was employed to assign the correct diagnosis in situations of disparity. Results of PET and SPECT were at least partially concordant in 110 patients (73%), although 22 had more than one defect. A reversible perfusion defect was identified in 60 patients, but the scans were concordant in only 20 (33%). These disparities were chiefly due to false-negative SPECT imaging (22 patients, 55%), and probable delayed thallium redistribution (13 patients, 33%). No patients had ischaemia correctly identified by SPECT in the presence of normal PET imaging. Persistent defects were identified in 91 patients, some of whom also had reversible defects, and the results were consistent in 54 (59%). Other than the delayed thallium redistribution group, the major categories causing disparities were false-positive (6 patients, 16%), and false negative SPECT (8 patients, 22%), attributable to attenuation and scatter. PET appears able to identify smaller, less ischaemic areas subtended by milder coronary stenoses. The availability of a true resting scan with Rb-PET enhances the discrimination between ischaemia and infarction. Attenuation correction, and the high energy photons of positron annihilation, yield more accurate evaluation of inferior wall defects and greater specificity in the presence of soft tissue attenuation.     

心肌桥患者~(99)Tc~m-MIBI运动负荷心肌血流灌注断层显像的特点

目的 总结和分析冠状动脉心肌桥患者99Tcm-MIBI运动负荷心肌血流灌注断层显像的特点.方法 回顾2003年至2009年经冠状动脉造影证实的冠状动脉心肌桥患者17例,分析其~(99)Tc~m-MIBI运动负荷心肌血流灌注断层显像放射性分布特点.结果 17例心肌桥患者中有12例患者出现异常心肌血流灌注断层影像.6例收缩期壁冠状动脉受压狭窄＜50%的患者中有2例患者出现异常心肌血流灌注断层影像,表现为可逆性缺损和反向再分布.4例收缩期壁冠状动脉受压狭窄50%～75%的患者中有3例患者出现异常心肌血流灌注断层影像,表现为可逆性缺损、部分可逆性缺损、固定缺损、反向再分布.7例收缩期壁冠状动脉受压狭窄75%～100%的患者心肌血流灌注断层影像异常率为100%,表现为可逆性缺损、部分可逆性缺损、固定缺损、反向再分布.结论 冠状动脉心肌桥患者可以导致心肌血流灌注断层显像异常.收缩期壁冠状动脉受压75%～100%心肌桥患者均出现异常心肌血流灌注断层显像.     

Myocardial perfusion abnormalities in asymptomatic patients with systemic lupus erythematosus

Accelerated coronary artery disease and myocardial infarction in young patients with systemic lupus erythematosus is well documented; however, the prevalence of coronary involvement is unknown. Accordingly, 26 patients with systemic lupus were selected irrespective of previous cardiac history to undergo exercise thallium-201 cardiac scintigraphy. Segmental perfusion abnormalities were present in 10 of the 26 studies (38.5 percent). Five patients had reversible defects suggesting ischemia, four patients had persistent defects consistent with scar, and one patient had both reversible and persistent defects in two areas. There was no correlation between positive thallium results and duration of disease, amount of corticosteroid treatment, major organ system involvement or age. Only a history of pericarditis appeared to be associated with positive thallium-201 results (p less than 0.05). It is concluded that segmental myocardial perfusion abnormalities are common in patients with systemic lupus erythematosus. Whether this reflects large-vessel coronary disease or small-vessel abnormalities remains to be determined.     

Single photon emission computed tomography of the thyroid

Single photon emission computed tomography (SPECT) entails imaging at multiple positions along an arc and computed-assisted reconstruction of transaxial, coronal, and sagittal images. To determine if SPECT imaging of the thyroid augments information provided by planar imaging, both SPECT and pinhole planar scans were performed in 52 patients with thyroid disease. After 123I (n = 45), Tc99m (n = 5), or thallium-201 (n = 2) administration, images were acquired at 30 intervals along a 180 degree arc. Nodules that were hypofunctioning on planar scans (n = 4) were equally well shown on SPECT images. SPECT analysis of 123I uptake by 5 palpable nodules with completely normal 123I planar scans demonstrated the nodular tracer uptake was increased (n = 1), equivalent (n = 3), or decreased (n = 1) in comparison with that of extranodular tissue. In 6 of 12 multinodular goiters, transaxial SPECT images showed tracheal compression, which was confirmed by neck x-ray, flow volume loops, or surgery. A neck phantom study was performed to assess the accuracy of SPECT-determined functional thyroid volume. SPECT-estimated volumes (30-173 mL; n = 11) correlated well with true volumes (r = 0.996; P less than 0.001). Our observations suggest that SPECT is a useful adjunct to planar imaging in 1) estimating functional volume for 131I dosimetry; 2) evaluating the size, extension, and tracheal compression of multinodular goiter; and 3) determining the functional properties of palpable nodules with normal 123I planar pinhole images.     

Myocardial perfusion imaging with positron emission tomography and single photon emission computed tomography: frequency and causes of disparate results

The purpose of this study was to compare rubidium-82 PET withthallium-201 SPECT imaging in 150 patients. Both techniquesfollowed a single dipyridamole-handgrip stress, and images weredisplayed using the same 3-dimensional format and quantitativecolour scale. Coronary arteriography was employed to assignthe correct diagnosis in situations of disparity. Results of PET and SPECT were at least partially concordantin 110 patients (73%), although 22 had more than one defect.A reversible perfusion defect was identified in 60 patients,but the scans were concordant in only 20 (33%). These disparitieswere chiefly due to false-negative SPECT imaging (22 patients,55%), and probable delayed thallium redistri bution (13 patients,33%). No patients had ischaemia correctly identified by SPECTin the presence of normal PET imaging. Persistent defects wereidentified in 91 patients, some of whom also had reversibledefects, and the results were consistent in 54 (59%). Otherthan the delayed thallium redistribution group, the major categoriescausing disparities were false-positive (6 patients, 16%), andfalse negative SPECT (8 patients, 22%), attributable to attenuationand scatter. PET appears able to identify smaller, less ischaemic areas subtendedby milder coronary stenoses. The availability of a true restingscan with Rb-PET enhances the discrimination between ischaemiaand infarction. Attenuation correction, and the high energyphotons of positron annihilation, yield more accurate evaluationof inferior wall defects and greater specificity in the presenceof soft tissue attenuation.