Interpretive intra- and interobserver reproducibility of rest/stress 99Tcm-sestamibi myocardial perfusion SPECT in a consecutive group of male patients with stable angina pectoris before and after percutaneous transluminal angioplasty

Reduced acquisition time for thallium myocardial perfusion imaging with large field cadmium-zinc-telluride SPECT/CT cameras: An equivalence study

BACKGROUND

Cadmium-zinc-telluride (CZT) SPECT/CT cameras with large field of view offer a higher sensitivity than conventional Anger cameras. This prospective study aimed to determine the equivalence between a conventional protocol and a reduced acquisition time protocol for 201-Thallium myocardial perfusion imaging (MPI) using a whole-body CZT SPECT camera.

METHODS AND RESULTS

Stress MPI was obtained for 103 consecutive patients on a DISCOVERY-CZT camera. Images were anonymized and post-processed to simulate a 25% (D75 dataset) and 50% (D50 dataset) decrease in total recorded counts. Concerning the number of segments displaying a tracer uptake < 70% of maximum intensity per patient, equivalence was demonstrated for both count-reduced datasets with a good inter-observer agreement (between 0.90 and 0.88). When comparing the full-vs-D75 datasets and full-vs-D50 datasets, mean difference was 0.06 segment (CI95: [- 0.15;0.27], P < 0.001) and 0.518 segment (CI95: [0.28;0.76], P < 0.001) respectively. Inter-observer agreement was also moderate to good concerning the number of pathological segments (between 0.6 and 0.7) and excellent for functional parameters.

CONCLUSION

Whole-body CZT SPECT/CT cameras allow to reduce 201-Thallium MPI injected activity or acquisition time by 50% with an equivalence in the number of segments displaying a tracer uptake < 70% of maximum intensity and with a good inter-observer agreement.

Stress-only myocardial perfusion scintigraphy: a prospective study on the accuracy and observer agreement with quantitative coronary angiography as the gold standard

OBJECTIVE

Patients with normal stress perfusion have an excellent prognosis. Prospective studies on the diagnostic accuracy of stress-only scans with contemporary, independent examinations as gold standards are lacking.

PATIENTS AND METHODS

A total of 109 patients with typical angina and no previous coronary artery disease underwent a 2-day stress (exercise)/rest, gated, and attenuation-corrected (AC), 99m-technetium-sestamibi perfusion study, followed by invasive coronary angiography. The stress datasets were evaluated twice by four physicians with two different training levels (expert and novice): familiar and unfamiliar with AC. The two experts also made a consensus reading of the integrated stress-rest datasets. The consensus reading and quantitative data from the invasive coronary angiography were applied as reference methods.

RESULTS

The sensitivity/specificity were 0.92-1.00/0.73-0.90 (reference: expert consensus reading), 0.93-0.96/0.63-0.82 (reference: ≥1 stenosis>70%), and 0.75-0.88/0.70-0.88 (reference: ≥1 stenosis>50%). The four readers showed a high and fairly equal sensitivity independent of their familiarity with AC. The expert familiar with AC had the highest specificity independent of the reference method. The intraobserver and interobserver agreements on the stress-only readings were good (readers without AC experience) to excellent (readers with AC experience).

CONCLUSION

AC stress-only images yielded a high sensitivity independent of the training level and experience with AC of the nuclear physician, whereas the specificity correlated positively with both. Interobserver and intraobserver agreements tended to be the best for physicians with AC experience.

Left atrial volume index: relation to long-term clinical outcome in type 2 diabetes

OBJECTIVES

The study sought to determine the prognostic importance of left atrial (LA) dilation in patients with type 2 diabetes mellitus (T2DM) and no history of cardiovascular disease (CVD).

BACKGROUND

T2DM is associated with the development of CVD, and morphological changes in the heart may appear before symptoms arise.

METHODS

A total of 305 T2DM patients without known CVD referred to a diabetes clinic were included consecutively (age 58.6 ± 11.3 years, diabetes duration 2.0 [interquartile range: 0 to 6.0] years). Each patient underwent a comprehensive echocardiogram and a myocardial perfusion scintigraphy (MPS) at inclusion. Patients were divided according to left atrial volume index (LAVi) ≥32 ml/m(2). Patients were followed for median of 5.6 (interquartile range: 5.1 to 6.1) years for the occurrence of major cardiac events and death.

RESULTS

LAVi ≥32 ml/m(2) was found in 105 patients (34%). During follow-up, 60 patients (20%) experienced the composite endpoint, of whom 28 (9%) died. Patients with LAVi ≥32 ml/m(2) had a significantly higher cardiac event rate and death rate (p < 0.001 and p = 0.002, respectively). Univariate predictors of the composite endpoint were age, hypertension, left ventricular diastolic function, E/e'septum-ratio and LAVi ≥32 ml/m(2); however, myocardial ischemia on MPS was not a predictor. When adjusting for age and hypertension, only LAVi ≥32 ml/m(2) was a predictor of the composite endpoint (hazard ratio: 1.82 [95% confidence interval: 1.08 to 3.07], p = 0.024).

CONCLUSIONS

Increased LAVi was an independent and incremental predictor of cardiovascular morbidity and mortality in T2DM patients with no history of CVD. (Presence of Macrovascular Disease in Type 2 Diabetes Mellitus; NCT00298844).

Myocardial ischemia, carotid, and peripheral arterial disease and their interrelationship in type 2 diabetes patients

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in type 2 diabetes mellitus (T2DM) patients. We examined the relationship between CVD in different vascular territories.

METHODS

T2DM patients without known or suspected CVD (n = 305) referred consecutively to a diabetes clinic for the first time and age-matched nondiabetic reference subjects (n = 40) were screened for myocardial ischemia, carotid, and peripheral arterial disease by means of myocardial perfusion scintigraphy, carotid artery ultrasonography, and peripheral ankle and toe systolic blood pressure measurements.

RESULTS

In the T2DM patients, the prevalence of myocardial ischemia, carotid, and peripheral arterial disease was 30%, 42%, and 15%, respectively, almost three times higher than in the reference subjects (P = 0.007, P = 0.001, and P = 0.09, respectively). T2DM patients with myocardial ischemia, carotid, or peripheral arterial disease had a significantly increased risk of CVD in other vascular territories as well (OR: 1.99, 2.09, and 3.09, respectively). However, 40%, 52%, and 22% of the T2DM patients with myocardial ischemia, carotid, or peripheral arterial disease demonstrated exclusively this particular type of CVD manifestation.

CONCLUSIONS

In T2DM patients, signs of CVD in one vascular territory carry a significantly increased risk of CVD in other territories, although many patients only presented one manifestation.

Left ventricular diastolic function in type 2 diabetes mellitus: prevalence and association with myocardial and vascular disease

BACKGROUND

Although type 2 diabetes mellitus is a risk factor for developing congestive heart failure, the mechanism leading to heart failure is unclear. We examined the prevalence of left ventricular (LV) systolic and diastolic dysfunction in patients with type 2 diabetes mellitus in relation to vascular function and myocardial perfusion.

METHODS AND RESULTS

A prospective observational study of 305 patients with type 2 diabetes mellitus (diabetes duration, 4.5+/-5.3 years) referred consecutively to a diabetes clinic were screened for LV systolic and diastolic function by echocardiography. Vascular function was estimated using noninvasive estimation of pulse pressure, carotid arterial compliance, total arterial compliance, and valvulo-arterial impedance. The prevalences of LV diastolic dysfunction and left atrial (LA) volume index >32 mL/m(2) were 40% and 32%, respectively. The prevalence of myocardial ischemia on myocardial perfusion scintigraphy was more frequent in patients with grade 2 diastolic dysfunction and LA volume index >32 mL/m(2) compared with those having normal or grade 1 diastolic dysfunction (P=0.002) or LA volume index < or =32 mL/m(2) (P<0.001), respectively. Predictors of grade 2 diastolic dysfunction and LA dilation were summed stress score on myocardial perfusion scintigraphy, total arterial compliance, and valvulo-arterial impedance, whereas pulse pressure and carotid arterial compliance were not, after adjusting for age, sex, and diabetes duration. On multivariable modeling, summed stress score (P<0.001) and valvulo-arterial impedance (P=0.027) remained predictors of grade 2 diastolic dysfunction, and only summed stress score (P<0.001) was a predictor of LA dilation.

CONCLUSIONS

Abnormal LV filling is closely associated with abnormal myocardial perfusion on myocardial perfusion scintigraphy, whereas the association of LV filling with vascular function is less prominent.

Prognostic validation of an algorithm to convert myocardial perfusion SPECT imaging data from a 12-segment model to a 17-segment model

BACKGROUND

A 17-segment model has become the standard for interpreting myocardial perfusion single-photon emission computed tomography (SPECT). Methods for converting pre-existing databases from 12-segment models to the 17-segment model are needed for ongoing prognostic studies.

METHODS AND RESULTS

To develop the conversion algorithm, 150 consecutive SPECT studies (82 abnormal) were read by both a 12-segment and the standard 17-segment models. Summed stress scores (SSSs) were calculated from a 17-segment model derived from the 12-segment data and compared to those of the standard 17-segment model. The effect of the conversion algorithm on prognostic data derived from the 12-segment model was evaluated in 25,876 patients from the Duke Nuclear Cardiology Database, including a sample of 3,205 patients with known covariates for adjusted analysis. The derived 17-segment SSS from the 12-segment model was highly correlated (R = 0.99) to the SSS from the standard 17-segment model. In both unadjusted and adjusted analysis, there was no difference in the prognostic information.

CONCLUSIONS

An algorithm for conversion of 12-segment perfusion scores to 17-segment scores has been developed which is highly correlated to visual interpretation by the 17-segment model with nearly identical prognostic information.

Dobutamine stress tetrofosmin SPECT; evaluation of short rest-stress protocol and head to head comparison with MIBI in detection of coronary artery disease

OBJECTIVE

The purpose of the present study was to evaluate the feasibility and diagnostic accuracy of same day short rest-dobutamine stress Tetrofosmin (TF) SPECT imaging protocol and to compare TF SPECT results with MIBI SPECT in the same subjects who were unable to perform treadmill exercise or were unsuitable for pharmacological vasodilator stress.

METHODS

The study group consisted of 19 patients (2 female and 17 male, with a mean age of 53.8 +/- 7.9 yrs) in whom coronary artery disease (CAD) had been proven or excluded at coronary angiography (CA). MIBI SPECT imaging was performed first. TF SPECT images were obtained one week after MIBI imaging. Immediately after the rest SPECT imaging in both of the MIBI and TF studies, patients underwent dobutamine stress tests. Rest-stress radiotracer doses and dobutamine doses were the same for both TF and MIBI studies. While 60 min waiting periods were applied for MIBI study, only 30 min waiting periods were applied for TF study after the rest and stress injections. Images were evaluated by visual and quantitative analysis.

RESULTS

Dobutamine stress parameters were similar for both studies. Although in TF study, the time between radiopharmaceutical injection and imaging was shorter than in MIBI study, there was no significant difference between heart-to-liver (H/Li) and heart-to-lung (H/Lu) ratios. According to CA results, diagnostic accuracy was similar for TF and MIBI. While sensitivity, specificity and accuracy for TF study were calculated as 82%, 84% and 82%, respectively, the corresponding values for MIBI were 82%, 88% and 84%, respectively. This clinical study has shown comparable diagnostic performance for the detection of CAD between MIBI and TF. Good correlation was found between segmental analysis for both studies.

CONCLUSION

MIBI and TF showed similar perfusion defects and good segmental correlation during dobutamine stress with the same quality images. Both radiopharmaceuticals may be acceptable with this imaging protocol. Besides this, TF study showed better reversibility degree (55%) in a shorter time when compared to MIBI study (25%) in perfusion defects (especially in segments with severely decreased perfusion or no uptake).

Comparison between dobutamine echocardiography and single-photon emission computed tomography for interpretive reproducibility

Interpretive variability of dobutamine stress echocardiography (DSE) and stress single-photon emission computed tomography (SPECT) has been previously investigated. However, no study has directly compared the variability of these techniques in the same patient population. We directly compared the interpretive reproducibility of DSE and stress SPECT in patients undergoing both types of pharmacologic stress imaging. Before discharge, simultaneous DSE and SPECT was performed in 56 patients early after a first acute myocardial infarction. Intra- and interobserver concordances were evaluated by exact agreement and kappa statistic. Intraclass coefficient of correlation was used to assess intra- and interobserver reproducibilities of segmental score analysis. Intraobserver agreement percentages in the identification of patients with ischemia were 98% for SPECT and 91% for DSE (p = NS) and kappa values were excellent (>0.80) for both techniques. Interobserver agreement was higher (p <0.01) for SPECT (96%) than for DSE (79%). Similarly, kappa value was excellent for SPECT (0.92) and only moderate for DSE (0.56). Finally, the intraclass coefficients of correlation for intra- and interobserver reproducibilities were higher for SPECT (0.98 and 0.97, respectively) than for DSE (0.80 and 0.71, respectively; p <0.001 for both). In conclusion, after uncomplicated acute myocardial infarction, stress SPECT imaging has a better interpretive reproducibility than DSE.

To what degree is amelioration of angina following coronary revascularization associated with improvement in myocardial perfusion?

OBJECTIVE

To examine the association between changes in chest pain and changes in perfusion following revascularization as assessed by clinical evaluation and myocardial perfusion imaging (MPI) in patients with stable angina.

DESIGN

In a prospective series of 380 patients (58.8 +/- 8.8 years) referred to angiography because of known or suspected stable angina, changes in chest discomfort and changes in perfusion after 2 years were assessed in 144 patients, who underwent revascularization, and 236, who did not. The decision to treat invasively was made without knowledge of the result of MPI.

RESULTS

In revascularized patients, the presence of typical/atypical angina was reduced from 93% to 36% and the improvement was associated with improvement in perfusion. A small improvement in perfusion induced a high frequency of change from angina to no pain, whereas a further reduction caused little extra change. In non-revascularized patients the change in chest discomfort was not related to changes in perfusion, which were rarely present.

CONCLUSION

Alleviation of chest discomfort 2 years after revascularization is associated with improvements in perfusion. This association appeared to be an all-or-nothing phenomenon. Non-revascularized patients also exhibited improvements in chest discomfort despite insignificant changes in perfusion.

Interobserver Agreement in the Interpretation of Single-Field Digital Fundus Images for Diabetic Retinopathy Screening

PURPOSE

To assess agreement among a group of ophthalmic care providers, including ophthalmologists and trained nonphysician personnel, in the interpretation of single-field digital fundus images for diabetic retinopathy screening.

DESIGN

Interobserver reliability study.

PARTICIPANTS

Twelve ophthalmic care personnel, including 3 retina specialists, 3 general ophthalmologists, 3 ophthalmic nurses, and 3 ophthalmic photographers.

METHODS

All participants were to read 400 good single-field digital fundus images of diabetic patients from a community hospital. The nonphysician personnel group read the images 1 month after attending a 2-day intensive instruction course regarding diabetic retinopathy screening. The ophthalmologists read the images without additional training. The 3 retina specialists read the images again together 2 months later to form a consensus regarding retinopathy severity and macular edema for each case. All readers used the Early Treatment Diabetic Retinopathy Study standard photographs as guidelines.

MAIN OUTCOME MEASURES

The kappa statistic was used for the reliability assessment of the diabetic retinopathy severity and macular edema, and for the identification of cases that needed referral to ophthalmologists.

RESULTS

There is only fair agreement among all readers. The multirater kappa coefficient for retinopathy severity is 0.34; for macular edema, 0.27; and for referral cases, 0.28. Retina specialists have the best agreement among all groups (kappa = 0.58 for retinopathy severity or macular edema, kappa = 0.63 for referrals). There is also fair agreement when all readers are compared with the consensus of retina specialists (kappas = 0.35, 0.28, and 0.29 for retinopathy severity, macular edema, and referrals, respectively), and the retina specialist group also has the best agreement (kappas = 0.63, 0.65, and 0.67 for retinopathy severity, macular edema, and referrals).

CONCLUSIONS

Without additional training, retina specialists may be the most reliable personnel to interpret single-field digital fundus images for diabetic retinopathy screening. For other ophthalmic care personnel to achieve comparable reliability, a comprehensive instruction course with specific continuing education is essential. Authorized nonphysician interpreters should be experts, and new standard photographs for single-field digital fundus image interpretation may also be required to improve interobserver reliability.

Determining myocardial viability in chronic ischemic left ventricular dysfunction: a prospective comparison of rest-redistribution thallium 201 single-photon emission computed tomography, nitroglycerin-dobutamine echocardiography, and intracoronary myocardial contrast echocardiography

BACKGROUND

Detection of viable myocardium (VM) has important therapeutic implications for chronic ischemic left ventricular (LV) systolic dysfunction. We compared the ability of nitroglycerin-dobutamine echocardiography (NTG-DE), intracoronary myocardial contrast echocardiography (MCE), and rest-redistribution thallium 201 single-photon emission computed tomography (RRT-SPECT) to detect VM in this setting.

METHODS

Patients with LV ejection fraction (LVEF) <40% and multivessel coronary disease suitable for revascularization underwent NTG-DE, MCE, RRT-SPECT, and radionuclide ventriculography to determine baseline LVEF. Myocardial contrast echocardiography was performed using intracoronary injection of Albunex. Patients who underwent revascularization had 3-month postprocedural radionuclide ventriculography and transthoracic echocardiography to assess functional recovery.

RESULTS

Of 512 myocardial segments in the 32 patients studied, 309 were akinetic or dyskinetic at baseline. Nitroglycerin alone increased regional thickening in 20% of segments with contractile reserve. By RRT-SPECT, 93% of nitroglycerin-responsive segments were viable. Myocardial contrast echocardiography had up to 85% sensitivity and 74% specificity for detection of VM diagnosed by RRT-SPECT. In the 23 patients who underwent revascularization, 54% of akinetic segments showed improved contractility, and mean LVEF increased from 32% to 37% (P = .04). Sensitivities and specificities for detecting functional recovery were 95% and 37% for RRT-SPECT, up to 87% and 48% for MCE, and 63% and 83% for a biphasic response during NTG-DE.

CONCLUSIONS

In patients with chronic ischemic LV dysfunction, RRT-SPECT had the highest sensitivity, and NTG-DE, the best specificity for detection of VM. Nitroglycerin facilitated detection of VM and may be a useful adjunct to dobutamine stimulation.

Diagnostic accuracy of myocardial perfusion imaging in a study population without post-test referral bias

BACKGROUND

Most previous studies on the accuracy of myocardial perfusion imaging (MPI) are hampered by post-test referral bias, in that referral for coronary angiography was influenced by the MPI result. In this way, patients with a normal MPI result less frequently underwent catheterization, a tendency supposed to cause an underestimation of test specificity and an overestimation of test sensitivity.

METHODS AND RESULTS

MPI by use of a gated dual-isotope protocol was undertaken before angiography in 357 patients referred for angiography for suspected stable angina pectoris. The MPI reports were kept secret to prevent post-test referral bias. The MPI study was normal in 215 patients (60%) and showed reversible perfusion abnormalities in 118 (33%) and fixed defects in 24 (7%). Angiography was normal in 231 patients (65%) and revealed 1 or more significant stenoses in 126 (35%). With angiography as the reference, the sensitivity and specificity of MPI for detecting significant coronary artery stenosis were 75% and 79%, respectively.

CONCLUSIONS

In this prospective study without post-test referral bias, we found a lower sensitivity and slightly higher specificity than in studies with post-test referral bias. The imperfect accuracy may reflect differences between anatomic and physiologic imaging.

Cervicothoracic Angina Identified by Case History and Palpation Findings in Patients with Stable Angina Pectoris

OBJECTIVE

To investigate the decision-making process of an experienced chiropractor in diagnosing noncardiac musculoskeletal chest pain of cervicothoracic angina in patients with stable angina pectoris, based on patient history and clinical examination. Secondly, to examine the possibility of obtaining an objective diagnostic rule tool for the identification of cervicothoracic angina and to validate the diagnosis of this disorder.

METHODS

A nonrandomized prospective trial was performed at a university hospital. A total of 516 of 972 consecutive patients referred for coronary angiography because of known or suspected angina pectoris were asked to participate in the study. Of these, 275 gave informed consent to a standardized manual examination of their spine and thorax. Diagnoses of an experienced chiropractor on cervicothoracic angina patients. Myocardial perfusion imaging and coronary angiography were used for validation. A set of candidate variables from patient history and clinical examination were tested for their role in the decision-making process.

RESULTS

Eighteen percent of the patients were diagnosed with cervicothoracic angina. Of these, 80% had normal myocardial perfusion compared to 50% of cervicothoracic angina-negative patients. The main determinants of the decision-making process could be identified.

CONCLUSION

An experienced chiropractor could identify a subset of patients with angina pectoris as having cervicothoracic angina. Systematic manual palpation of the spine and thorax could be used as part of the clinical examination together with basic cardiological variables to screen patients with chest pain allowing for improvements in referral patterns for specialist opinion or angiography.

Observer variability in the evaluation of dual-isotope Tl-201/Tc-99m sestamibi rest/stress myocardial perfusion SPECT in men and women with known or suspected stable angina pectoris

BACKGROUND

Observer variability of dual-isotope myocardial perfusion imaging (MPI) with single photon emission computed tomography has rarely been investigated. The aim of our study was to evaluate the interpretive reproducibility with this technique.

METHODS AND RESULTS

We report on 507 patients with known or suspected stable angina who were studied before coronary angiography. A 1-day thallium 201/technetium 99m sestamibi rest/stress MPI protocol was used. MPI was interpreted by 2 independent observers without knowledge of clinical data, using a 20-segment scoring model. By consensus, the overall rate of abnormal MPI was 49% (59% in men and 34% in women). The interobserver agreement for the whole group (kappa = 0.85) and for men and women separately (kappa = 0.86 and 0.82, respectively) was excellent with regard to the overall diagnosis (normal, reversible, or fixed defects) as well as left anterior descending and left circumflex artery vascular territories (kappa = 0.85 and 0.82, respectively). However, in the right coronary artery territory, agreement was excellent in men (kappa = 0.83) but moderate in women (kappa = 0.57).

CONCLUSIONS

In a relatively large group of men and women with stable angina pectoris, interpretive reproducibility (overall and individual vessel diagnosis) was excellent, except in the right coronary artery territory of women, in which it was moderate.

Dobutamine Tc-99m furifosmin SPECT in detection of coronary artery disease: evaluation of same day, rest-stress protocol

The purpose of this study was to evaluate the feasibility and diagnostic accuracy of same day rest-stress myocardial perfusion SPECT (MP SPECT) protocol by using technetium-99m (Tc-99m) furifosmin in conjunction with dobutamine stress test in subjects in whom coronary artery disease (CAD) had been proven or excluded at coronary angiography (CA). The study group consisted of 25 patients (8 female and 17 male with a mean age of 53.04 +/- 8.56 yrs) unable to perform treadmill exercise or unsuitable for pharmacologic vasodilator stress testing. Ten mCi (370 MBq) of Tc-99m furifosmin was injected intravenously at rest. Sixty min after injection, planar and SPECT images were acquired. One hour later all patients underwent dobutamine stress test. At the peak stress, 20 mCi (740 MBq) of Tc-99m furifosmin was injected. Sixty min after stress dose injection, planar and SPECT images were acquired. Rest-stress planar and SPECT data were evaluated by using visual and quantitative analysis. Heart to adjacent organ (Heart/Lung; H/Lu and Heart/Liver; H/Li) activity ratios were calculated from anterior planar images by using regions of interest (ROI). SPECT data were interpreted by using 20 segment-5 point scoring system from short axis and vertical long axis slices. The results of rest-dobutamine stress Tc-99m furifosmin MP SPECT were compared with CA results. There were statistically significant differences between H/Lu and H/Li ratios at rest and stress conditions. Heart/adjacent organ activity ratios were similar and significant statistical difference could not be found between CA positive and CA normal patients. Sensitivity, specificity and accuracy for Tc-99m furifosmin SPECT study were calculated as 90%, 80% and 84% for left anterior descending (LAD), 87%, 94% and 92% for left circumflex (LCx) and 67%, 86% and 80% for right coronary artery (RCA), respectively. Overall sensitivity, specificity and accuracy were calculated as 83%, 87% and 85%, respectively. According to the results obtained in this study, it may be concluded that same day rest-dobutamine stress Tc-99m furifosmin SPECT protocol is a feasible and accurate technique in the evaluation of CAD, especially in patients unable to perform treadmill exercise or unsuitable for pharmacologic vasodilator stress testing.

Gated fluorine 18 fluorodeoxyglucose positron emission tomography: determination of global and regional left ventricular function and myocardial tissue characterization

BACKGROUND

Our objectives were to investigate the accuracy of global and regional left ventricular (LV) function parameters determined from gated fluorine 18 deoxyglucose (FDG) positron emission tomography (PET) and to determine whether this approach complements viability imaging data for tissue characterization. Nongated FDG-PET is a clinical standard for viability imaging, but LV function is often determined with other techniques, which increases patient burden, expenditure, and co-registration errors. Better tissue characterization may be achieved if data were acquired with one test. Methods and results Forty-eight patients with LV dysfunction (including 35 with ejection fraction [EF] </=35%) underwent perfusion/FDG imaging with gating of the FDG images and radionuclide angiography (RNA) 6 +/- 6 days apart. Regional function (wall motion/thickening) and viability pattern (normal, mismatch, nontransmural scar, and transmural scar) were determined for 301 segments. Global EFs from FDG-PET (29.3% +/- 11.5%) and RNA (31.1% +/- 10.4%) were well correlated: EF(FDG-PET) = 0.91 x EF(RNA) + 0.91 (r = 0.83, P <.00001). Regional wall motion concordance between PET and RNA with three wall motion scores was 67% with moderate agreement (kappa = 0.50, P <.001). PET viability was also determined for each segment. The relative frequency of normal motion compared with abnormal motion decreased with worsening viability classification. Of the normal segments, 96 of 139 (69%) had reduced wall motion, suggesting repetitively stunned myocardium. Segments classified as normal or mismatch had a higher frequency of normal wall thickening (65% and 52%) than wall motion (31% and 17%). No segments classified as transmural scar exhibited normal wall thickening.

CONCLUSION

Gated FDG-PET accurately measures global LV function. Regional function can also be determined with reasonable accuracy. This approach also provides precise co-registration of function with metabolic information and thus improved tissue characterization of the myocardium. Gated FDG-PET has the potential to assist in optimizing management of this patient population.

Agreement among ophthalmologists in evaluating fluorescein angiograms in patients with neovascular age-related macular degeneration for photodynamic therapy eligibility (FLAP-study)

OBJECTIVE

To determine intraobserver and interobserver variation for classifying types of choroidal neovascularizations (CNV) in exudative age-related macular degeneration (ARMD).

DESIGN

Intraexaminer and interexaminer reliability study.

PARTICIPANTS

Digital high-quality fluorescein angiograms of 40 patients with neovascular ARMD were evaluated independently by 16 retinal specialists.

MAIN OUTCOME MEASURES

Fluorescein angiographies were presented in two randomized sequences (series A and B) to each masked reader for classification of type of CNV into classic, occult, or mixed with classic component of less or greater 50%. Agreement was evaluated by calculating kappa statistics (kappa) and intraclass correlation coefficients.

RESULTS

The mean kappa coefficient was 0.64 +/- 0.11 for intraobserver variation, with a range from 0.44 to 0.89. For interobserver variation the intraclass correlation coefficients was calculated as 0.66 (95% confidence interval [CI] 0.56, 0.77) for series A and as 0.55 (95% CI 0.43, 0.67) for series B.

CONCLUSIONS

Angiographic classification of CNV secondary to ARMD can vary considerably not only between observers but also for repeated evaluation by the same observer. Because various current and emerging treatments including photodynamic therapy are based on specific angiographic characteristics, accurate interpretation will become more important.