Negative Single Photon Emission Computed Tomography Research Articles

CORRELATION BETWEEN MYOCARDIAL PERFUSION IMAGING AND CAROTID ULTRA-SONOGRAPHY IN PATIENTS WITH CHEST PAIN

Background: Atherosclerosis is a major risk factor for coronary artery disease (CAD). Carotid ultrasound (U/S) may be a useful method for prediction of CAD through measurement of intimio-media thickness (IMT) of right and left common carotic arteries. Objective: To emphasize the correlation between myocardial perfusion imaging using single photon emission computed tomography (SPECT) and carotid ultrasound through measuring IMT in early prediction and diagnosis of CAD. Patients and methods: The study included 80 patients complaining from chest pain. Single photon emission computed tomography (SPECT) and carotid U/S were done to each of them. All Patients were recruited from El-Hussein university hospital outpatient clinic and Kobry El-Koba military hospital outpatient clinic between February 2020 and November 2020. Results: The study included 80 patients, 57 of them were males while 23 of them were females. 52 patients were hypertension (HTN), 31 patients were diabetes mellitus (DM), 33 patients were smokers, 15 patients of them had positive family history. 52 patients had positive SPECT stress test revealing CAD “ischemic group”, while 28 of them had negative SPECT stress test “Non-ischemic group”. For the ischemic group, 43 patients (82.7%) had increased intimio-media thickness IMT. Right IMT mean ± SD “0.69±0.10”, t-test “7.771”, weighted Kappa test 0.655 substantial agreement and P-value “p <0.001”. Lefy IMT mean ± SD “0.77±0.12”, t-test “5.122” , weighted Kappa test 0.614 substantial agreement and p-value “p <0.001”. Only 9 patients (17.3%) from the ischemic group had below 75th percentile IMT. For Non-ischemic group, only 9 patients (32.1%) had abnormal IMT while the other 19 patients (67.9%) had normal IMT. Conclusion: Carotid ultrasound and intimio-media thickness are good predictors and highly correlated to coronary artery disease.

Efficient 1-Hour Technetium-99 m Pyrophosphate Imaging Protocol for the Diagnosis of Transthyretin Cardiac Amyloidosis.

Technetium-99 m pyrophosphate protocols for transthyretin cardiac amyloidosis diagnosis have variably used 1- and 3-hour imaging time points. We investigated whether imaging at 1 hour with superior efficiency had comparable diagnostic accuracy as 3-hour imaging. This is a registry analysis of patients with suspected transthyretin cardiac amyloidosis referred for technetium-99 m pyrophosphate at a single tertiary center from June 2015 through January 2019. Patients underwent planar and single-photon emission computed tomography (SPECT) imaging at 1 and 3 hours. A positive Tc-99m pyrophosphate study was defined by the presence of diffuse myocardial tracer uptake on SPECT. For planar imaging, visual semiquantitative (grades 0-3, ≥2 considered positive) and quantitative heart to contralateral ratios (≥1.5 considered positive) were used. Two hundred thirty-three patients (69% men; median age, 77 [69-83] years) underwent the study protocol. There were 60 (25.8%) patients with diffuse myocardial uptake, 1 (0.4%) with regional uptake, and 172 (73.8%) with no myocardial uptake. Results of SPECT were identical at 1 and 3 hours. Planar imaging at 1 hour had 98% sensitivity and 96% specificity. Planar grade 0 uptake or heart to contralateral ratio ≤1.2 and planar grade 3 uptake or heart to contralateral ratio ≥2.0 were always associated with negative and positive SPECT, respectively. For planar grades 1 and 2 uptake and heart to contralateral ratio 1.3 to 1.9, SPECT was needed to make a diagnosis. No patient with light-chain cardiac amyloidosis had positive SPECT. An efficient 1-hour technetium-99 m pyrophosphate protocol had comparable diagnostic performance to a 3-hour protocol.

Postexercise stunning in type II diabetes mellitus assessed by 2D speckle tracking echocardiography and gated-SPECT myocardial perfusion imaging

Background Type II diabetes mellitus (DM) is usually associated with a number of myocardial structural and functional changes. Noninvasive imaging techniques play a key role in the identification of these changes. Objective Detection of postexercise myocardium stunning in type II DM patients by 2 dimensional speckle tracking Echo (2D STE) and single photon emission computed tomography (SPECT) imaging. Patients and methods The authors enrolled 60 symptomatic patients with type II DM who were classified into different groups: Group I included 17 patients with normal left ventricular global longitudinal strain (LVGLS) and negative SPECT; group II included 43 patients with impaired LVGLS and negative SPECT; and group III included 10 patients with impaired LVGLS and positive SPECT. The authors evaluate LV functions and dimensions before and early after exercise by conventional, tissue Doppler, 2D STE, and gated-SPECT perfusion imaging. Coronary angiography for group III. Results This study shows statistically significant difference between early and late gated SPECT regarding left ventricular end diastolic volume (LVEDV) and EF% between the three different groups. There were significant decrease in average LVGLS from (−20.79±1.04 pre-exercise) vs (−16.15±1.28 postexercise) in group I from (−15.98±1.75 pre-exercise) vs (−14±2.47 postexercise) in group II and from (−15.82±3.44 pre-exercise) vs (−13.48±2.75 postexercise) in group III. Eight out of 10 patientﹶs had coronary artery disease in group III. Conclusion Transient ischemic stunning and dilatation remained a robust marker for high-risk scan especially in type II DM. LVGLS correlated well with gated SPECT in the detection of postexercise LV stunning. LVGLS is a very sensitive parameter and paramount for early detection of LV subclinical systolic dysfunction in diabetic patients.

Does SPECT Provide Incremental Value to CT or MRI in Assessing Mandibular Invasion by Oral Squamous Cell Carcinoma?

Single photon emission computed tomography (SPECT) has been commonly used as an additional method to assess mandibular bone invasion in patients with oral squamous cell carcinoma (OSCC). In the present study, we measured the diagnostic validity of SPECT findings compared with the histologic findings. We implemented a retrospective cross-sectional study and enrolled a sample of patients with OSCC adjacent to the mandible. The staging examinations included magnetic resonance imaging (MRI) and/or computed tomography (CT) and additional SPECT. The patients' medical records and imaging data were reviewed by 2 readers, and bone invasion was classified as positive or negative for each diagnostic method. The predictor was bone invasion found on CT and/or MRI compared with the combination of CT and/or MRI with either positive or negative SPECT results. The primary outcome variable was histologic bone invasion. Other variables of interest were clinicopathologic data, type of mandibular resection, and resection margin status. Bivariate tests were used to compare the diagnostic specificity, sensitivity, and accuracy of each imaging modality. The study enrolled 122 patients, with a mean age of 67years (55% male; study period, January 2010 to December 2017). In 60 patients (49%), segmental mandibular resection was performed. The sensitivity and specificity for bone invasion were 100% and 39% for SPECT and 84% and 75% for CT and/or MRI. The negative results for bone invasion using SPECT did not match the false-positive CT and/or MRI results in 5% (n=6 of 122). Positive SPECT findings, in addition to positive CT and/or MRI findings increased the sensitivity to 100% but decreased the specificity to 29% (P<.001). Considering only negative SPECT findings increased the specificity to 85% (P=.03), sensitivity remaining unaffected. The accuracy of CT and/or MRI alone was 80% and was 84% when combining CT and/or MRI and negative SPECT findings (P=.03). In oncologic staging with CT and/or MRI, the addition of SPECT provided only small benefits. Only negative SPECT results allowed for greater specificity and accuracy. The use of SPECT could be considered to rule out bone invasion in cases of radiologic uncertainty of positive CT or MRI findings.

Value of early rest myocardial perfusion imaging with SPECT in patients with chest pain and non-diagnostic ECG in emergency department.

Evaluation of atypical presentation of angina chest pain in emergency department is difficult. Hospitalization of this patient may impose additional costs and waste the time, early discharge may lead to miss the patients. The aim of this study was to determine volubility of Single Photon Emission Computed Tomography (SPECT) in management of patients admitted to emergency department with atypical manifestations of angina pain, un-diagnostic Electrocardiogram (ECG) and negative enzyme. Half of 100 patients admitted to emergency department with atypical chest pain and un-diagnostic ECG who were candidate for admission, underwent ECG gated resting SPECT. According to the results of SPECT, low risk patient discharged after negative stress SPECT. All discharged patients were followed up for major cardiac events (cardiac death, nonfatal myocardial infarction and repeat admission for congestive heart failure) for 12months. According to rest SPECT Myocardial Perfusion Imaging (MPI), about 70% of patients in case group was low risk and 30% of them had moderate or high risk. Case group represented lower hospitalization rate and lower need for Coronary Artery Angiography (CAG) in comparison with control group. Mean cost in case group was significantly lower than control group (175.15$ vs. 391.33$, P < 0.001). In one year follow- up no cases of mortality or major cardiovascular events as cardiac infraction were found in discharged patients in case group. our study showed that rest SPECT fulfillment in admitted patients in emergency department was validated method for assessing patients' risk which avoids unnecessary hospitalizations and additional costs.

Prognosis of anatomic coronary artery disease without myocardial ischemia: Coronary computed tomography angiography detects high-risk patients even in cases of negative single-photon emission computed tomography findings

BackgroundWhile coronary computed tomography angiography (CCTA) provides comprehensive anatomic evaluation of coronary artery disease (CAD) with prognostic implications, clinically, the focus is usually placed on presence or absence of functionally significant CAD. Herein, we aimed to suggest a new risk stratification strategy using CCTA in patients with anatomic CAD but without myocardial ischemia on single-photon emission computed tomography (SPECT). MethodsConsecutive patients (n=798) with CAD on CCTA who underwent SPECT for evaluation of myocardial ischemia were retrospectively evaluated. The primary outcome was the occurrence of adverse cardiac events, including cardiac death, nonfatal myocardial infarction, unstable angina, and late revascularization. ResultsOf the enrolled patients, 542 (68%) showed no perfusion defect (PD) on SPECT. During the follow-up (median, 22.6 months), adverse cardiac events occurred in 23 patients without PD (4.6%). Presence of plaque in ≥4 coronary segments, plaque in the left main or proximal left anterior descending coronary artery, and partially calcified plaque presence were independent predictors of adverse events. When we defined the CCTA score based on these 3 predictors (0–3 points), the annualized event rates increased with increasing CCTA scores. Patients with a CCTA score of 3 were associated with a 23-fold risk increase (adjusted HR 23.18; p=0.003) and showed unfavorable event-free survival, comparable to those with PD on SPECT (p=0.191). ConclusionAnatomic CAD patients without evidence of myocardial ischemia on SPECT but with high-risk characteristics on CCTA showed unfavorable outcomes, comparable to those with PD. CCTA allows further risk stratification even in patients with negative SPECT findings.

Clinical usefulness of epicardial adipose tissue in patients with high-intermediate pre-test probability for coronary artery disease.

Epicardial adipose tissue (EAT) is thought to be associated with the extension and severity of coronary artery disease (CAD), and echocardiographic measurement of EAT thickness is considered to be a possible cardiovascular risk indica-tor. The European Society of Cardiology Task Force recommends further non-invasive testing in patients with an intermediate pre-test probability (PTP) for the diagnosis of CAD. We sought to evaluate the clinical usefulness of performing EAT measurements in patients with a high-intermediate PTP. Patients referred to an outpatient clinic with stable chest pain symptoms, with PTP for CAD between 66% and 85%, were included in the study. Echocardiographic measurement of the EAT was identified as the echo-free space between the outer wall of the myocardium and the visceral layer of the pericardium. Single-photon emission computed tomography (SPECT) was performed in all patients. The diagnosis of CAD was based on the presence of reversible perfusion defects on SPECT. A total of 126 patients (76 men, 60.3%) with a mean age of 65.3 ± 9.1 years were recruited. The EAT thickness was 7.3 ± 0.7 mm in patients with positive SPECT and 6.2 ± 0.6 mm in patients with negative SPECT (p < 0.001). Multivariable analysis revealed higher rates of positive SPECT in patients with higher EAT (odds ratio [OR] 9.80; 95% confidence interval [CI] 3.72-25.79; p < 0.001), and receiver operating characteristic curve analysis showed that the greatest specificity was obtained when the cut-off value of EAT thickness was 6.75 mm (sensitivity 76%; specificity 74%). In patients with high-intermediate PTP, EAT is a useful measurement that may assist in risk stratification.

Skeletal abnormalities detected by SPECT is associated with increased relapse risk in pediatric acute lymphoblastic leukemia.

ObjectivesMost children with acute lymphoblastic leukemia (ALL) exhibit skeletal abnormalities. This study aimed to investigate bone lesions detected by whole-body bone single-photon emission computed tomography (SPECT) and its prognostic value in children with ALL.MethodsA retrospective analysis was performed using whole-body bone SPECT scans obtained from children with ALL in our department between June 2008 and June 2012. A total of 166 children newly diagnosed with ALL were included, and the patients were divided into two groups: patients with positive and negative SPECT scans. We compared the clinical characteristics of the two groups and analyzed the relationship between the skeletal abnormalities detected by SPECT and prognosis.ResultsAmong the 166 patients, bone scintigraphic abnormalities was detected by SPECT scan in sixty-four patients (38.6%). The most common site was the limbs. There were no significant differences in age, gender, WBC count at diagnosis, risk group and minimal residual disease (MRD) level between SPECT-positive patients and their SPECT-negative counterparts. The event-free and overall survival rates were higher in SPECT-positive patients, but the difference was not statistically significant. However, patients with positive SPECT scans, especially those with multifocal abnormalities (≥3 sites), had a higher rate of relapse (P < 0.05). Multivariate analyses identified that abnormal SPECT scan (HR = 3.547, P = 0.015) was an independent relapse risk.ConclusionChildren with ALL and multiple skeletal abnormalities will suffer from relapse. Abnormal SPECT scan was associated with increased relapse risk which might be a potential relapse marker for ALL children.

Factors affecting the sensitivity of Tc-99m methoxyisobutylisonitrile dual-phase parathyroid single photon emission computed tomography in primary hyperparathyroidism.

The aim of this study was to investigate the effects of thyroid diseases and regularly used medications on the sensitivity of Tc-99m methoxyisobutylisonitrile (MIBI) dual-phase parathyroid single photon emission computed tomography (SPECT) and to define indicatives of the result of the study. Overall, 218 primary hyperparathyroidism patients (190 women, 28 men, mean age: 57±14 years) with thyroid-parathyroid ultrasonography and Tc-99m MIBI dual-phase parathyroid SPECT were retrospectively enrolled. Patients were divided as follows: a positive SPECT group [119 (54.6%) patients] and a negative SPECT group [99 (45.4%) patients]. The effects of thyroid diseases and use of calcium channel blockers, β-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, oral antidiabetics, thyroid hormone preparates, nonsteroidal anti-inflammatory drugs, and proton pump inhibitors on the sensitivity of Tc-99m MIBI dual-phase parathyroid SPECT were investigated. The frequency of NSAID usage was higher in the negative scan group (P<0.001). No significant difference was detected in terms of coexisting thyroid disease or usage of other medications. Overall sensitivity, specificity, positive, and negative predictive value of Tc-99m MIBI dual-phase parathyroid SPECT were calculated to be 89.6, 92.5, 94.1, and 86.9%. The sensitivity was low only in nonsteroidal anti-inflammatory drug users (75.6%) compared with nonusers (96.5%). Logistic regression showed that ultrasonography was indicative of a positive scan and the possibility of a negative result was increased by regular usage of nonsteroid anti-inflammatory drugs (odds ratio: 0.262, confidence interval: 0.128-0.538; P<0.001) CONCLUSION: Among various drug groups, NSAIDs may decrease the sensitivity of Tc-99m MIBI SPECT and, provided that these novel data are supported by other studies, patient preparation may be modified to stop NSAIDs before Tc-99m MIBI dual-phase parathyroid SPECT.

SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY IN DIAGNOSTICS OF OBSTRUCTIVE LESION IN CORONARY ARTERIES

Aim. To evaluate the potential of single photon emission computed tomography (SPECT) in diagnostics of obstructive lesion of coronary arteries (CA). Material and methods. The studied group consisted of 107 patients, admitted for diagnostics and treatment in the SRI CICVD during 2012-2015 with former established diagnosis of coronary heart disease (CHD) or hospitalized to rule it out. For hemodynamically significant stenoses, coronary arteriography (CAG) was applied. Data from CAG was compared with SPECT. As a result, four groups were formed: 1 group — with positive results by SPECT and CAG (SPECT“+”/CAG“+”, n=24); 2 group — with positive SPECT and negative CAG (SPECT“+”/CAG“-”, n=6); 3 group — with negative SPECT and positive CAG (SPECT“-”/CAG“+”, n=36); 4 group — negative both SPECT and CAG (SPECT“-”/CAG“-”, n=41). Results. In assessment of the patients with suspected CHD, positive result of pharmacological stress-test in SPECT was revealed in 28% cases, and hemodynamically significant CA lesion was found in 56% of patients. Myocardial infarction in anamnesis predominated in SPECT“+”/CAG“+” (79,2%), SPECT“+”/CAG“-” (83,3%), SPECT“-”/CAG“+” (55,6%) comparing to SPECT“-”/CAG“-” (39%; р=0,007). Also, in the group SPECT“-”/CAG“-” pre-test probability of CHD was the lowest (58%) comparing to other groups — 80,5%; 80,5% and 77% (р=0,002). Hence ejection fraction of the left ventricle was significantly lower in the group of SPECT“+”/CAG“+” (53%; р=0,011). In this group also subocclusion was found in circumflex (29,2%) and right CA (45,8%), respectively, р=0,033 and р=0,054. With the false negative results of SPECT there was association of male gender, former coronary bypass operation, increased cardiac volume. Sensitivity of SPECT in hemodynamically significant CA stenoses diagnostics was 40%, specificity — 87%. Conclusion. The results of current study are important for further elaboration on the approaches to obstructive CHD diagnostics.

Angina Relief by Ranolazine Identifies False-Negative SPECT Myocardial Perfusion Scans in Patients with Coronary Disease Demonstrated by Coronary Angiography.

Normal myocardial perfusion imaging (MPI) reduces intermediate- or high-risk pretest probability patients to low- or intermediate-risk posttest probability, respectively, for coronary disease (CD). Since ranolazine (RAN) relieves only angina, anginal patients with normal MPI whose angina is relieved by RAN present a significant dilemma. The purpose of this retrospective chart review was to confirm the impression that coronary angiography (CA) is indicated in patients whose class 3 to 4 angina is relieved by RAN, but have normal myocardial single-photon emission computed tomography (SPECT) MPIs. Charts of patients with stable class 3 to 4 angina (typical and atypical) and normal MPIs (left ventricular ejection fraction [LVEF] ≥50% and segmental score = 0) were reviewed. CA was done on all the patients with complete angina relief taking RAN, as well as nonresponders whose anginal etiology could not be explained. Stenoses were considered flow-restrictive when more than 70% diameter stenosis is observed by quantitative CA, or, when 50 to 70%, fractional flow reserve (FFR) measured ≤0.80. RAN relieved angina in 36 of 54 (67%) patients. Of the known cases, 25 of these 36 (69%) had 43 stenoses ≥50% (mean = 66%): 15 (60%) had 1 vessel disease; 9 (36%) had multivessel disease; 18 (72%) had left anterior descending (LAD) disease; 1 (4%) had left main disease. Twenty one of 43 (49%) stenosis were > 70%; 22 (51%) stenoses were 50 to 70% and required FFR measurement. Twenty nine of 43 stenoses (67%) were considered flow-restrictive in 18 of these 25 (72%) patients. Eight RAN nonresponders with no explanation for angina had no CD at CA. RAN angina relief is invaluable in identifying falsely negative SPECT MPI, and 50% of these patients have flow-restrictive stenoses.

Radioguided Parthyroidectomy is Successful in 98.7% of Selected Patients

To examine an individualized approach to patients with primary hyperparathyroidism (PHPT) in an effort to identify factors that would differentiate patients who can be treated with radioguided parathyroidectomy (RP) from those that require more extensive parathyroid exploration (PE) using intraoperative parathyroid hormone (IOPTH) measurement and to compare rates of recurrent and persistent hypercalcemia. A total of 100 patients were retrospectively studied. Patients with positive single photon emission computed tomography (SPECT) scans underwent surgeon-performed sonography (SPS) followed by RP. Patients with negative or equivocal SPECT scans underwent PE utilizing SPS as a guide and IOPTH. The success rate, recurrence and persistence rates, and rate of bilateral exploration were compared. Seventy-five percent of patients with PHPT had a positive SPECT scan and underwent RP, whereas 25% of patients had a negative SPECT scan and underwent PE with IOPTH utilizing SPS as a guide. Persistent hypercalcemia was noted in 1 patient (1.3%) and recurrent hypercalcemia in 2 patients (2.6%) in the RP group, whereas no persistent hypercalcemia was noted in the group undergoing PE utilizing SPS and IOPTH. Overall, 89% of patients were cured with unilateral surgery. Patients with positive SPECT scans may undergo RP with an expected cure rate of 98.7%. Patients with negative SPECT scans should undergo SPS followed by PE using IOPTH and can expect a cure rate near 100%. Properly selected patients may undergo RP, with low rates of persistent (1.3%) and recurrent (2.6%) hypercalcemia.

Predictors for Functionally Significant In-Stent Restenosis: An Integrated Analysis Using Coronary Angiography, IVUS, and Myocardial Perfusion Imaging

The aim of this study was to assess the clinical and morphological predictors for functionally significant in-stent restenosis (ISR).Although they have been studied de novo in native coronary artery lesions, the relationships between clinical and morphological characteristics and the hemodynamic significance of ISR are not well understood.In 175 patients with ISR of a single coronary artery (angiographic stenosis >50%), we compared quantitative coronary angiography and intravascular ultrasound (IVUS) with stress myocardial single-photon emission computed tomography (SPECT). A positive SPECT was a reversible perfusion defect in the territory of the ISR artery.Overall, 103 (59%) patients had a positive SPECT. In-segment IVUS minimal lumen area (MLA) was significantly smaller in lesions with positive SPECT compared with negative SPECT (1.7 ± 0.5 mm(2) vs. 2.4 ± 0.8 mm(2), p < 0.001). Stent underexpansion (minimal stent area <5.0 mm(2)) was more common in the positive SPECT group than in the negative SPECT group (52% vs. 32%, p = 0.010). A positive SPECT was seen in 54% (65 of 121) of focal ISR lesions compared with 70% (38 of 54) of multifocal or diffuse ISR lesions as assessed by IVUS (p = 0.039). Independent determinants for a positive SPECT were diabetes (odds ratio [OR]: 2.41; 95% confidence interval [CI]: 1.02 to 5.68; p = 0.046), in-segment angiographic diameter stenosis (OR: 1.06; 95% CI: 1.03 to 1.09; p < 0.001), in-segment IVUS-MLA (OR: 0.30; 95% CI: 0.14 to 0.63; p = 0.001), stent underexpansion (minimal stent area <5.0 mm(2)), (OR: 2.91; 95% CI: 1.19 to 7.07; p = 0.019), proximal location of the IVUS-MLA (OR: 4.62; 95% CI: 1.75 to 12.18; p = 0.002), and a multifocal or diffuse ISR pattern (OR: 2.50; 95% CI: 0.99 to 6.28; p = 0.050). An in-segment angiographic diameter stenosis ≥69.5% (72% sensitivity, 74% specificity, area under the curve = 0.793) and an IVUS-MLA ≤1.9 mm(2) (67% sensitivity, 75% specificity, area under the curve = 0.756) best predicted a positive SPECT; however, the overall diagnostic accuracies were only 73% and 70%, respectively.In lesions with ISR, neither angiography nor IVUS accurately predicted an abnormal SPECT.

SPECT ventilation perfusion scanning with the addition of low‐dose CT for the investigation of suspected pulmonary embolism

Single-photon emission computed tomography (SPECT) ventilation perfusion (V/Q) scanning with low-dose computed tomography (LDCT) is an emerging imaging technique for investigation of suspected pulmonary embolism (PE). We aimed to estimate diagnostic utility of the combined technique using results from all patients referred in 2009 compared with final diagnosis and 6-month follow-up status. PE was diagnosed in 28 of 106 patients (26%), including in 2 of 80 (2%) with negative SPECT V/Q and LDCT. The estimated negative predictive value of SPECT V/Q for PE was 97%. LDCT was abnormal in 43 (41%) patients, including 41 patients who had negative SPECT V/Q. In 29 (27%) patients, LDCT provided information on alternative pathologies that accounted for presenting symptoms, and the combined technique had a diagnostic yield of 52%.

Clinical Utility of N-13 Ammonia Cardiac PET Perfusion Imaging in the Assessment of Epicardial Coronary Lesions of Intermediate Range

Objective: To identify the high risk myocardial perfusion defects which prognosticate the future ischemic cardiac events, on Positron emission tomography (PET) myocardial perfusion imaging (MPI) of intermediate coronary stenosis (ICS) on coronary angiogram (CAG) with negative single photon emission computed tomography (SPECT) MPI in chronic stable angina (CSA) patients. Methods: For this study non-infarcted CSA patients of single vessel disease (SVD) on CAG with ICS and normal LV function were selected. In all patients with negative stress SPECT MPI, stress PET MPI was done. In both scans, extent score (ES), severity score (SS), total severity/extent score ratio (TS-ES R) and Left ventricular dilatation (LVD) were noted. Patients with Positive PET MPI were closely followed for 2yrs and PCI was performed depending on symptoms. Results: Out of 47 study group patients, during 2yr follow up period, 11 out of 15 patients with ischemia positive PET MPI underwent percutaneous coronary intervention (PCI). Indication for PCI was rest or persistence or recurrence of angina. Four of 15 patients remained asymptomatic. In medically managed vs. PCI done patients, mean of ES was 1.2 ± 0.5 vs. 2.3 ± 1, SS was 1.2 ± 0.5 vs. 5.3 ± 1.9, TS-ESR was 1 vs. 2.5 ± 0.5 which was statistically significant (p = 0.01). Conclusion: It was inferred that subgroup of PET MPI positive ICS patients with basal PET MPI showing SS > 5 and TS-ES R > 1.5 with LVD during stress required close follow up as they are likely require PCI subsequently. Condensed Abstract: As negative for inducible ischemia by single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) is associated with low cardiac event rate, even though positive imaging by Positron emission tomography myocardial perfusion imaging (PET MPI), in patients with intermediate Coronary stenosis (ICS) may not require immediate percutaneous coronary intervention (PCI). We fol-lowed these patients for two 2yrs and identified that basal PET MPI showing total severity score > 5 and total severity/ extent score ratio > 1.5 with Left ventricular dilatation during stress required PCI subsequently.

A comparison of reconstruction and viewing parameters on image quality and accuracy of stress myocardial CT perfusion

Myocardial stress computed tomography perfusion (CTP) has similar diagnostic accuracy for detecting perfusion defects (PDs) versus single-photon emission computed tomography (SPECT). However, the optimal diagnostic viewing and image processing parameters for CTP are unknown. We sought to compare the diagnostic accuracy of different image processing techniques, cardiac phases, slice thicknesses, and viewing parameters for detection of PDs. A stress and rest dual-source CTP protocol was performed with adenosine. Twelve subjects with severe stenosis proven by quantitative coronary angiography (QCA), with corresponding territorial defects at SPECT, were selected as well as 7 controls (subjects with similar clinical suspicion but negative QCA and SPECT). Short-axis stress images were processed with 3 techniques: minimum intensity projection (MinIP), maximum intensity projection, and average intensity multiplanar reconstruction (MPR), 3 thicknesses (1, 3, 8 mm), and 2 phases (systolic, mid-diastolic). The resulting images (n = 1026) were randomized and interpreted by independent readers. Diastolic reconstructions (8-mm MPR) showed the highest sensitivity (81%) to detect true PDs. The highest accuracy was achieved with the 8-mm (61%) and 1-mm (61%) MPR diastolic images. The most sensitive and accurate systolic reconstructions were 3-mm MinIP images. These findings related to viewing in relatively narrow window width and window level settings. Viewing parameters for optimal accuracy in detection of perfusion defects on CTP differ for systolic and diastolic images.

Validation of Minimal Luminal Area Measured by Intravascular Ultrasound for Assessment of Functionally Significant Coronary Stenosis: Comparison With Myocardial Perfusion Imaging

This study sought to evaluate the ability of minimal luminal area (MLA) measured by intravascular ultrasound (IVUS) to assess the functional significance of coronary artery disease. The use of IVUS to determine the functional significance of coronary artery lesions remains a matter for debate. From our prospective IVUS imaging database, between July 2009 and April 2010, 170 coronary lesions in 150 patients who underwent stress myocardial single-photon emission computed tomography (SPECT) performed within 1 month of IVUS evaluation were identified and analyzed. MLA and other parameters were measured by IVUS and compared with the results of myocardial SPECT. Overall, 45 lesions had positive SPECT, and 125 lesions had negative SPECT. The MLA of lesions with positive SPECT was smaller than the MLA of those with negative SPECT (1.7 ± 0.5 mm² vs. 2.3 ± 1.1 mm², p < 0.001). By logistic regression analysis, MLA (odds ratio: 3.1 by decrease of 1 mm², 95% confidence interval [CI]: 1.75 to 5.5, p < 0.01) was an independent predictor of the positive SPECT. Using receiver-operator characteristic curve analysis, the best cutoff value of MLA was ≤ 2.1 mm² with an 86.7% sensitivity, a 50.4% specificity, a 38.6% positive predictive value, and a 91.3% negative predictive value versus lesions with a positive SPECT (area under the curve: 0.690, 95% CI: 0.615 to 0.759, p < 0.01). The best cutoff value of MLA measured by IVUS to predict myocardial ischemia was 2.1 mm². The IVUS-measured MLA appeared to play a limited role in detecting functionally significant lesions assessed by myocardial SPECT.

Very high coronary calcium score unmasks obstructive coronary artery disease in patients with normal SPECT MPI

ObjectivesTo study the clinical impact of a very high coronary artery calcium score (CAC >1000) in patients with no known coronary artery disease (CAD) and normal single photon emission computed...

Assessment of mandibular invasion of squamous cell carcinoma by various modes of imaging: constructing a diagnostic algorithm

The aim of this study was to determine the optimal combination of preoperative examination methods to predict mandibular invasion by squamous cell carcinoma of the oral cavity. Data were gathered prospectively but evaluated retrospectively. The preoperative results of clinical examination, conventional radiography, bone single photon emission computed tomography (SPECT), computed tomography and magnetic resonance imaging were compared to the histological results of resection specimens from 67 patients with tumours, adjacent or fixed to the mandible, histologically confirmed as squamous cell carcinoma. The examination methods with acceptable sensitivity and specificity were selected and diagnostic algorithms were constructed using all possible combinations. The preferred diagnostic algorithm was found to be either computed tomography or magnetic resonance imaging, followed by a bone SPECT in cases where the first scan is negative. A negative bone SPECT rules out mandibular invasion (100% sensitivity). This algorithm accurately predicted mandibular invasion in 85% of the patients, without yielding false negative results. In this study group, application of such an algorithm would have resulted in a reduction of the number of unnecessary mandibular resections by 50%. The suggested, preferred, diagnostic algorithm shortens the preoperative screening process, avoiding unnecessary costs, as well as considerably reducing the number of unnecessary mandibular resections.

OUR EXPERIENCES WITH MEASUREMENT OF NEW POTENTIAL BIOMARKERS IN THE DIAGNOSIS OF LATENT FORMS OF MYOCARDIAL ISCHEMIA

The need for a laboratory marker of myocardial ischemia has been alluded to for at least the last decade. The aim of this study was to evaluate the diagnostic importance of the myosin light chain-1 (MLC-1), clusterin and Reg-Ialpha in patients with suspected myocardial ischemia. A group of 176 at high-risk for myocardial ischemia subjects was evaluated and divided into two subgroups using myocardial SPECT (Single Photon Emission Computed Tomography) - individuals with and without signs of myocardial ischemia. Laboratory markers in venous blood were repeatedly examined in all subjects: a) immediately prior to SPECT: C-reactive protein, Haemoglobin, Hematocrite, Lactate, MLC-1, Clusterin, Reg-Ialpha b) at subjective maximum: Hb, Htc, lactate, MLC-1, Clusterin, Reg-Ialpha c) 30 min after stress levels reached their peak: MLC-1, Clusterin, Reg-Ialpha and d) 60 min after peak stress levels: MLC-1, Clusterin, Reg-Ialpha. Patients were divided into subgroups according to their positive and negative SPECT results (positive: n = 37; negative: n = 139). MLC-1 values were different for all 4 blood collections. An increase in MLC-1 > 2.2 mg/l showed 64 % sensitivity and 88 % specificity for the diagnosed presence of myocardial ischemia (AUC 0.81; LR+ 5.9; PPV+ 68 % and NPV- 87 %). There was no significant difference between the groups in terms of Clusterin and Reg-Ialpha for any of the sampling periods. High diagnostic efficacy of detectable MLC-1 was shown for the diagnosis of latent myocardial ischemia. Measurement of serum Clusterin or Reg-Ialpha did not sufficient for the diagnosis of latent myocardial ischemia.