Abnormal Single Photon Emission Computed Tomography Findings Research Articles

The value of myocardial perfusion imaging in screening coronary artery disease before kidney transplantation.

The value of myocardial single-photon emission computed tomography (SPECT) in pre-transplant evaluation of kidney transplant recipients is controversial. We assessed whether myocardial SPECT predicts major adverse cardiac events (MACE) and determined whether SPECT findings affected transplant recipients' medical and invasive treatment. We analyzed 301 patients referred for myocardial SPECT before kidney transplantation and combined the results with information from patient files and the Transplantation Registry. During the median follow-up time of 96months (IQR 70.75-118.25months), the incidence of MACE was higher in patients (n=37) with severely abnormal SPECT (>10% reversible perfusion defect) than in patients (n=35) with mildly abnormal or normal SPECT (51.4%, 29.4%, and 27.0%, respectively, P=.011). Severely abnormal SPECT findings predicted long-term MACE in a univariable analysis but not after adjusting for other risk factors. Following SPECT, 29 patients (9.6%) underwent coronary angiography and 14 (4.6%) were revascularized. New antithrombotic or statin medication was prescribed to 7.3% of patients with ischemia in SPECT. Kidney transplantation patients are at high long-term risk of MACE even with normal preoperative myocardial SPECT. Abnormal SPECT did not predict MACE when adjusted for other risk factors. Minority of the patients underwent coronary revascularization or had changes in preventive medication before transplantation.

Spinal Fluid Cytokine Levels and Single-Photon Emission Computed Tomography Findings in Complex Febrile Seizures.

In this study, the authors assessed cerebrospinal fluid cytokine levels and single-photon emission computed tomography (SPECT) findings in complex febrile seizures. This study included 23 Japanese patients with complex febrile seizures. Twenty patients underwent SPECT and 12 underwent analysis of cerebrospinal fluid cytokine levels (interleukin [IL]-6, interleukin-10, interleukin-17, interleukin-1β, tumor necrosis factor-α, and interferon-γ); 9 patients underwent both studies. Cerebrospinal fluid cytokine levels were compared between the current complex febrile seizure patients and 30 patients with acute encephalopathy. In 17 of 20 patients, SPECT findings revealed areas of hypoperfusion, including the frontal (5), occipital (4), and lobular (4) regions, overlapping with other areas. Relative to patients with acute encephalopathy, those with complex febrile seizures exhibited significantly lower cerebrospinal fluid interleukin-6, interleukin-1β, tumor necrosis factor-α, and interleukin-10 levels and significantly higher interleukin-17 levels. As patients with complex febrile seizures frequently exhibit abnormal SPECT findings, cerebrospinal fluid interleukin-17 levels might provide a valid biomarker to discriminate complex febrile seizures and acute encephalopathy, regardless of SPECT findings.

Diagnostic Performance of 3D Bull’s Eye Display of SPECT and Coronary CTA Fusion

ObjectivesThe aim of this study was to develop a display method to describe the fusion data of myocardial perfusion single-photon emission computed tomography (SPECT) and coronary computed tomography angiography into a single image that we call fusion-based bull’s eye (FBE). This study sought to show its generating process and evaluate its diagnostic performance. BackgroundThree-dimensional (3D) display is mostly used when reviewing SPECT/coronary computed tomography angiography fusion images, although multidirection interpretation is required to sweep the entire heart. Bull’s eye display of the fusion image will be useful in clinical practice. MethodsFBE images were generated from the 3D fusion data by determining a cardiac axis, adding a cylindrical object around the aortic root, obtaining a panoramic image from circumferential data of the 3D images, and converting it into a polar coordinate display image. The diagnostic performances of SPECT, the conventional 3D fusion, and FBE as to the presence of hemodynamically relevant coronary vessels were compared in 39 patients with abnormal SPECT findings. ResultsThe 3D fusion and FBE images were successfully obtained in all patients. Of an evaluated 105 coronary segments in 35 patients without coronary artery bypass grafting, SPECT showed 17 segments (16%) equivocal to determine hemodynamically relevant coronary vessels. FBE corrected the diagnoses of 5 segments, in which SPECT was false-negative in 2 or false-positive in 3, with only 2 equivocal segments (p = 0.0017). FBE also revealed 4 culprit lesions in all 4 patients with coronary artery bypass grafting. There were no discordances between FBE and the 3D fusion. ConclusionsFBE had the same capacity as the 3D fusion to solve equivocal SPECT findings or correct the diagnoses in 24 of 109 (22%) coronary segments for culprit lesion detection. Although FBE requires manual generation process at present, it facilitates evaluation of myocardial perfusion and coronary anatomy with only 1 image.

Coronary Artery Calcium Scoring to Exclude Flow-Limiting Coronary Artery Disease in Symptomatic Stable Patients at Low or Intermediate Risk

To assess the capability of a zero coronary artery calcium (CAC) score to help exclude flow-limiting coronary artery disease (CAD) in a homogeneous population with stable anginal complaints and a low-to-intermediate pretest likelihood. The study protocol had institutional ethics committee approval, with written informed consent from all patients. Between 2009 and 2011, a total of 3501 consecutive stable patients without known CAD underwent prospectively simultaneous myocardial perfusion imaging and CAC scoring on a hybrid, 64-section single photon emission computed tomography (SPECT)/computed tomography (CT) scanner. In 868 (25%) of 3501 patients, the CAC score was zero, and these patients constituted the current study population. When feasible, additional coronary CT angiography was performed in those with abnormal SPECT findings. Clinical follow-up was recorded with regard to invasive coronary angiography, coronary revascularization, nonfatal myocardial infarction, or death. Results were analyzed by using descriptive statistics. In 868 patients (mean age, 54 years ± 11 [standard deviation]; 610 [70%] female, 258 [30%] male), SPECT findings were normal in 766 (88%) and abnormal in 102 (12%), with equivocal results in 41 (5%), persistent defect in 35 (4%), and ischemia in 26 (3%). In the group with abnormal SPECT findings, additional coronary CT angiography was performed in 93 patients (91%), showing nonobstructive CAD in eight patients (9%) and normal coronary arteries in 85 patients (91%). In the other nine patients (9%), invasive angiography was used to exclude obstructive CAD. At a median follow-up of 17 months (25th percentile, 11; 75th percentile, 24 months), no coronary events were recorded. A CAC score of zero in stable patients at low or intermediate risk excludes flow-limiting CAD. These findings support the possibility of CAC scoring as a simple and safe tool to select patients for additional testing or discharge, as recommended in the literature.

Diagnostic impact of SPECT image display on assessment of obstructive coronary artery disease

Diagnostic assessment of myocardial perfusion impacts the management of patients with suspected coronary artery disease (CAD). Although various image displays are available for single photon emission computed tomography (SPECT) interpretation, the effects of display differences on SPECT interpretation remain undetermined. We studied 183 patients undergoing SPECT, including 131 consecutive patients referred for angiography and 52 at low CAD risk. Studies were visually interpreted by use of color and gray images, with readers blinded to the results of the other display. In accordance with established criteria, a summed stress score (SSS) of 4 or greater was considered abnormal. The prevalence of abnormal SPECT findings was higher with gray images than with color images (54% vs 48%, P < .001) based on a uniform criterion (SSS > or =4). However, color images yielded equivalent sensitivity (79% vs 82%, P = .7) and improved specificity for global (50% vs 33%, P = .02) and vessel-specific CAD involving the right coronary artery (P < .01) and left anterior descending artery (P < .05). When the criterion for gray images was adjusted upward (SSS > or =5) to reflect increased mean defect severity (SSS of 5.1 vs 4.4, P = .01), gray and color images provided equivalent sensitivity and specificity for global and vessel-specific CAD. SPECT interpretation can vary according to image display as a result of differences in perfusion defect severity. Adjustment of abnormality criteria for gray images to reflect minor increases in defect severity provides equivalent diagnostic performance of gray and color displays for CAD assessment.

Coronary artery disease investigated using 99mTc‐tetrofosmin myocardial SPECT

Coronary artery disease can be diagnosed from stress and delayed images of myocardial single photon emission computed tomography (SPECT) using technetium-99 m-tetrofosmin (TcTF). However, the negative predictive value of stress SPECT images after a single injection of a low tracer dose remains unknown. Thus, the present study investigates whether normal stress SPECT results predict event-free survival. We screened 302 consecutive patients who were randomly assigned to two groups for myocardial ischaemia using either stress SPECT with a low dose of TcTF (296 MBq, TcTF group, n = 150) or stress together with rest SPECT using thallium(201) chloride (TlCl, 111 MBq; TlCl group, n = 152) as the tracer. A total of 80 patients with abnormal SPECT findings were excluded and the remaining 222 with normal results (age, 66.5 +/- 0.7 years; TcTF/TlCl, 112/110) were enrolled in the present study and followed up for 401 +/- 9 days, with the endpoint being ischaemic cardiac events. The incidence of cardiac events did not differ between the two groups (0.9% and 0.0% in TcTF and TlCl groups, respectively). The cost and duration of TcTF and TlCl SPECT examinations were about 425 and 603 Euros and 50 and 280 min, respectively. The negative predictive values of stress SPECT using a low dose of TcTF and of combined stress and rest SPECT using TlCl did not differ and both were clinically acceptable. Thus, stress SPECT using low dose TcTF is useful in screening patients for myocardial ischaemia.

Cardiovascular Disease Risk Stratification With Stress Single-Photon Emission Computed Tomography Technetium-99m Tetrofosmin Imaging in Patients With the Metabolic Syndrome and Diabetes Mellitus

The metabolic syndrome represents a constellation of risk factors caused by insulin resistance, dyslipidemia, hypertension, and obesity, resulting in elevated coronary disease risk. From a multicenter prospective registry of 7,849 patients, the relation among the metabolic syndrome, diabetes, and risk stratification with stress technetium-99m tetrofosmin single photon-emission computed tomography (SPECT) was evaluated. The percentage of stress myocardial defects was calculated as < or = 5%, 5.1% to 10%, 10.1% to 15%, and > 15%. A Cox proportional-hazards model was used to estimate cardiovascular death or myocardial infarction (n = 752). Of 7,849 patients, 42% had the metabolic syndrome. Patients with the metabolic syndrome had an 84% 2-year event-free survival rate, lower than patients with normal metabolic status (p <0.0001). In patients with the metabolic syndrome, the percentage of moderate to severely abnormal SPECT findings ranged from 11% to 44% for those with 3 to 5 risk factors for the metabolic syndrome. There was an additive relation between the number of risk factors for the metabolic syndrome and the extent and severity of abnormalities in SPECT findings (p <0.0001). Patients with 5 risk factors for the metabolic syndrome were at the greatest risk, with hazard ratios from 7.8- to 14.1-fold for mild to severely abnormal SPECT findings. For diabetic patients requiring combined oral and insulin therapy, relative risk ratios increased from 15 to 21.4 for patients with > 5% to > 15% stress myocardial perfusion defects. In conclusion, cardiovascular prognosis is affected by the degree of metabolic dysfunction, and stress-induced reductions in myocardial perfusion provide an accurate means for near-term risk stratification.

Image fusion analysis of 99mTc-HYNIC-Tyr3-octreotide SPECT and diagnostic CT using an immobilisation device with external markers in patients with endocrine tumours

The aim of this study was to assess the value of multimodality imaging using a novel repositioning device with external markers for fusion of single-photon emission computed tomography (SPECT) and computed tomography (CT) images. The additional benefit derived from this methodological approach was analysed in comparison with SPECT and diagnostic CT alone in terms of detection rate, reliability and anatomical assignment of abnormal findings with SPECT. Fifty-three patients (30 males, 23 females) with known or suspected endocrine tumours were studied. Clinical indications for somatostatin receptor (SSTR) scintigraphy (SPECT/CT image fusion) included staging of newly diagnosed tumours (n=14) and detection of unknown primary tumour in the presence of clinical and/or biochemical suspicion of neuroendocrine malignancy (n=20). Follow-up studies after therapy were performed in 19 patients. A mean activity of 400 MBq of (99m)Tc-EDDA/HYNIC-Tyr(3)-octreotide was given intravenously. SPECT using a dual-detector scintillation camera and diagnostic multi-detector CT were sequentially performed. To ensure reproducible positioning, patients were fixed in an individualised vacuum mattress with modality-specific external markers for co-registration. SPECT and CT data were initially interpreted separately and the fused images were interpreted jointly in consensus by nuclear medicine and diagnostic radiology physicians. SPECT was true-positive (TP) in 18 patients, true-negative (TN) in 16, false-negative (FN) in ten and false-positive (FP) in nine; CT was TP in 18 patients, TN in 21, FP in ten and FN in four. With image fusion (SPECT and CT), the scan result was TP in 27 patients (50.9%), TN in 25 patients (47.2%) and FN in one patient, this FN result being caused by multiple small liver metastases; sensitivity was 95% and specificity, 100%. The difference between SPECT and SPECT/CT was statistically as significant as the difference between CT and SPECT/CT image fusion (P<0.001). Twenty-seven abnormal SPECT findings in 17 patients could not be initially assigned to organs, but were clearly delineated after image fusion. In 21 patients (40%), clinically relevant information was obtained by image fusion as compared with SPECT alone. Co-registration of SPECT and diagnostic CT using a cost-effective immobilisation device provides excellent accuracy for tumour detection of endocrine malignancies and is superior to SPECT and CT alone. Image fusion reduces false positive results and can detect additional lesions. Anatomical information provided by CT enables precise localisation of abnormalities observed in SPECT.

Discordance between dipyridamole technetium-99m-sestamibi myocardial perfusion single photon emission computed tomography and two-dimensional echocardiography in Kawasaki disease--a preliminary report.

This study attempts to establish a noninvasive diagnostic method for early assessment of cardiac involvement in Kawasaki disease (KD), 36 children with KD were studied. The presence of abnormal coronary arteries (CA) with aneurysms was determined by experienced pediatric cardiologists using two-dimensional echocardiography (2D-Echo). Rest and dipyridamole-stress technetium-99m sestamibi (Tc-MIBI) single photon emission computed tomography (SPECT) was performed on the 36 children with KD for the assessment of myocardial perfusion and for comparison with 2D-Echo findings. The results showed that (1) 17/36 (47.2%) of the cases had no aneurysm and 19/36 (52.8%) had significant aneurysms; (2) 16/36 (44.4%) of the cases had normal myocardial perfusion and 20/36 (55.6%) had myocardial perfusion defects; (3) 9/36 (25.0%) cases showed both normal 2D-Echo and Tc-MIBI SPECT findings and 12/36 (33.3%) showed both abnormal 2D-Echo and Tc-MIBI SPECT findings; and (4) There was poor agreement between 2D-Echo and Tc-MIBI SPECT findings (kappa-value = 0.161, p = 0.332). We concluded that the most of the KD children had aneurysms or abnormal myocardial perfusion. However, poor agreement exists between 2D-Echo and Tc-MIBI SPECT findings with aneurysms and abnormal myocardial perfusion in patients with KD.

Discordance between dipyridamole stress technetium-99m tetrofosmin single photon emission computed tomography and coronary angiography in patients with Kawasaki disease.

Kawasaki disease (KD) is an acute vasculitis syndrome of unknown etiology that mainly affects the coronary arteries. The purpose of this study was to assess the agreement between dipyridamole stress technetium-99m tetrofosmin (Tc-TF) myocardial perfusion single photon emission computed tomography (SPECT) and coronary angiography in these patients. Twenty-nine children with KD were included in this study. All of the 29 children also received dipyridamole stress Tc-TF myocardial perfusion SPECT within 1 month of their coronary angiographic studies. The results showed that (1) 89.7% of children had negative coronary angiographic findings without significant coronary stenoses, and 10.3% of children had positive coronary angiographic findings with significant coronary stenosis; (2) 44.8% of children had negative Tc-TF myocardial perfusion SPECT findings without abnormal myocardial perfusion, and 55.2% of children had positive Tc-TF myocardial perfusion SPECT findings with abnormal myocardial perfusion; (3) 44.8% of children had both normal coronary angiographic and Tc-TF myocardial perfusion SPECT findings, and 10.3% of children had both abnormal coronary angiographic and Tc-TF myocardial perfusion SPECT findings; and (4) There was no significant agreement between coronary angiographic and Tc-TF myocardial perfusion SPECT findings. We concluded that poor agreement exists between coronary angiographic and Tc-TF myocardial perfusion SPECT findings with coronary stenoses and abnormal myocardial perfusion in children with KD.

Can persisting detrusor hyperreflexia be predicted after transurethral prostatectomy for benign prostatic hypertrophy?

Detrusor hyperreflexia (DH) is frequently found in patients with benign prostatic hypertrophy (BPH) and persists in 30-50% of patients after successful removal of bladder neck obstruction by transurethral prostatectomy (TUR-P) or surgical enucleation of the prostate. It would be beneficial for surgeons to be able to identify patients who are at risk of persistent post-operative urinary irritation symptoms and DH. Twenty-three patients who showed DH pre-operatively were included in this study. Of these 23 patients, four had neurogenic bladder because of previous cerebrovascular disease. The other 19 patients were considered to have DH because of BPH. These 19 patients were classified according to their cystometry chart patterns. Pattern 1 was the continual sporadic onset and offset of DH, pattern 2 was a single episode of DH at a bladder volume of <160 mL, and pattern 3 was a single DH episode at a bladder volume >160 mL. Preoperative single-photon emission computed tomography (SPECT) was performed on 14 patients. Cystometric findings at 3 to 6 months after surgery were compared with the pre-operative findings. Four of the six patients with pattern 2 (67%) and all patients with pattern 3 (100%) showed an absence of DH after surgery. In contrast, all five patients with pattern 1 and all four patients with neurogenic bladder showed persistent DH. Compared with pattern 3 patients, pattern 1 patients more frequently complained of urgency before surgery, and their symptoms and uroflowmetry parameters did not improve afterward. Among 14 patients who had pre-operative SPECT, all eight patients with low cerebral blood flow in the frontal region showed persisting DH. Conversely, all six patients with normal SPECT results showed no DH after surgery. When DH occurs repeatedly (pattern 1) or occurs at a bladder volume of <160 mL (pattern 2), there is a greater risk of post-operative irritation symptoms. Abnormal SPECT findings can also predict the post-operative persistence of DH. Combing these two pre-operative examinations allows us to predict better post-operative DH in patients with BPH.

Cerebral hypoperfusion during acute Kawasaki disease.

Kawasaki disease is a febrile disease of children notable for systemic vasculitis. There have been many previous reports of various complications, including disorders of the central nervous system. We evaluated cerebral perfusion during the acute stage in patients with Kawasaki disease. Single-photon emission-computed tomography (SPECT) with 99mTc-hexamethylpropyleneamine oxime was performed in 21 children with acute stage Kawasaki disease. Follow-up SPECT and MRI were performed about 1 month after the first SPECT in patients who exhibited abnormal SPECT findings during the acute stage. In 6 of 21 children SPECT imaging demonstrated localized cerebral hypoperfusion without abnormal neurological findings or clinical symptoms, and the follow-up SPECT and MRI approximately 1 month after the first SPECT revealed no abnormalities. Some patients with Kawasaki disease have transient localized cerebral hypoperfusion at the acute stage.

Subclinical cerebral involvement in Behcet's disease: a SPECT study.

Neurologic involvement has been reported in Behcet's disease (BD) with prevalence rates of 4-49%. Involvement of the central nervous system (CNS) usually follows systemic manifestations of BD by months to years, but as the initial future in only 5% of cases. The variance of the prevalence rates of neurologic involvement in BD raises the possibility of subclinical neurologic involvement. For the purpose of explaining the variance in the prevalence rates, 20 patients with BD, but without neurological symptoms and signs, were investigated by using cerebral single photon emission computed tomography (SPECT) which seems to be more convenient for BD than other scanners. A control group of patients with various diseases that were not expected to influence the cerebral blood flow was included. Brain magnetic resonance imaging (MRI) scans were performed in cases in which abnormal SPECT findings were obtained. Decreased and asymmetrical tracer uptakes were detected in 35% of patients with BD. MRI scans were normal in these patients. We concluded that functional imaging using SPECT may detect abnormalities at an initial stage prior to their progression to morphological damage detectable by MRI, and this imaging modality can be used even in cases which show no neurologic symptom to indicate the subclinical neurologic involvement.

Single photon emission computed tomography in systemic lupus erythematosus with psychiatric symptoms.

Single photon emission computed tomography (SPECT) with n-isopropyl-p-[123I]iodoamphetamine (IMP) was performed on 20 patients with systemic lupus erythematosus (SLE). Fifteen of the patients showed areas of hypoperfusion. All nine patients who had florid psychiatric manifestations at the time the SPECT was performed had hypoperfusion areas. Four patients who had abnormal SPECT findings during psychiatric remission had psychiatric exacerbation one to six months after the SPECT. Four patients who had no hypoperfusion during psychiatric remission had good psychiatric prognoses. Two patients who had no history of psychiatric abnormality but showed hypoperfusion had psychiatric manifestations one month after the SPECT. The IMP-SPECT may be useful as a biological marker that represents the activity of cerebral involvement underlying psychiatric manifestations and the presence of subclinical CNS involvement.

Pediatric Cerebrovascular Disease Alterations of Regional Cerebral Blood Flow Detected by TC 99m-HMPAO SPECT

Regional cerebral blood flow (rCBF) alterations, as determined by single photon emission computed tomography (SPECT) using technetium Tc 99m hexamethyl propylenamine oxime (Tc 99m-HM-PAO), were studied in 15 infants and children presenting with cerebrovascular disorders between the ages of 2 weeks and 16 years. The rCBF patterns were correlated with clinical presentation, electroencephalographic patterns, radiologic studies, including computed tomography and magnetic resonance imaging of the head, and cerebral angiography. All patients presented with motor weakness that was accompanied in some with dysphasia, defects in visual fields, obtundation, seizures, and high temperature. Perturbations of rCBF with Tc 99m-HMPAO SPECT brain scanning were detected in all patients investigated, with no adverse effects related to the radiotracer. All patients had a focal area of decreased rCBF, with adjacent hyperemia in 3 patients. In 7 patients, there was an rCBF decrease in a vascular distribution, mainly that of the middle cerebral artery, that correlated with the clinical findings and a focal electroencephalogram, as well as computed tomography and magnetic resonance imaging of the head. Impairment of rCBF was more extensive in 3 children, while early abnormal SPECT findings preceded abnormal computed tomographic findings in another 2 children. In 2 patients, Tc 99m-HMPAO SPECT was the only positive radiologic test to correlate with focal clinical and electroencephalographic abnormalities, in view of repeated normal computed tomographic scans. We conclude that Tc 99m-HMPAO SPECT brain scanning is a sensitive, complementary diagnostic measure in the early detection, localization, and estimation of rCBF alterations in pediatric cerebrovascular disease.