RESUMO
BACKGROUND: Normal stress-only (SO) myocardial perfusion imaging (MPI) using SPECT reduces imaging time and radiation dose with a good prognosis. However, the long-term prognostic value of combining coronary artery calcium score (CACS) with SO MPI to determine the warranty period remains unknown. Hence, we assessed the incremental prognostic value of CACS and its impact on the warranty period of normal SO MPI using SPECT. METHODS: We retrospectively included 1375 symptomatic patients without a history of coronary artery disease (CAD) and a normal SO MPI using adenosine who underwent simultaneous CAC scoring. Annual major adverse cardiac events (MACE) rates were calculated for CACS categories: 0, 1-399, 400-999, and ≥1000. RESULTS: The mean age was 60.0 ± 11.8 years (66.9% female) with a median follow-up of 10.3 [IQR 9.6-10.9] years. The warranty period for annual MACE rate for normal SO SPECT extended the total follow-up time in years. MACE rate categorized by CAC categories demonstrated an increase in MACE rates with increasing CACS; CACS 0 and CACS 1-399 were associated with a 10-year warranty period, CACS 400-999 had a warranty period of 4 years and no warranty period could be given for CACS≥1000 (5.9 % at 1 year). CONCLUSIONS: CACS as an adjunct to normal pharmacological SO MPI provides additional prognostic information and aids in determining a warranty period.
Assuntos
Doença da Artéria Coronariana , Imagem de Perfusão do Miocárdio , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Masculino , Cálcio , Vasos Coronários/diagnóstico por imagem , Estudos Retrospectivos , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada de Emissão de Fóton Único , Doença da Artéria Coronariana/diagnóstico por imagem , Prognóstico , Angiografia Coronária/métodosRESUMO
BACKGROUND: Fractional Flow Reserve (FFR) is increasingly used to estimate the severity of coronary stenoses, prior to coronary revascularization. However, it has been suggested that FFR overestimates the severity of Left Anterior Descending (LAD) lesions. Our aim was to verify whether in patients without ischemia on Myocardial Perfusion Imaging, FFR of the LAD is more often abnormal in comparison to FFR of other coronary arteries. METHODS: Prospective cohort study of consecutive patients who underwent FFR measurement because of persistent or worsening of angina complaints, within 6 months after normal Myocardial Perfusion Imaging. FFR measurements of a graft or diagonal branch were excluded. A FFR ≤ 0.80 denoted a functionally relevant stenosis. RESULTS: In 133 patients, 167 FFR measurements were performed, of which 85 in the LAD. Mean age of the patients was 64.8 ± 10.5 years, 40% were women. There were no differences in baseline characteristics between patients undergoing LAD and non-LAD measurements. An abnormal FFR was observed in 35.3% of the LAD measurements, compared to 9.8% in the non-LAD measurements (P = 0.001). Also after adjusting for age and gender, the FFR remained more frequently abnormal in the LAD with OR 5.2 (95% CI 2.2 to 12.3). Of the abnormal FFR LAD measurements, 70% were visually considered non-obstructive on invasive angiography. CONCLUSIONS: In selected patients without ischemia on MPI, FFR measurement of the LAD is significantly more often abnormal. The majority of these patients has no obstructive lesions on invasive angiography. Possibly, FFR overestimates severity of LAD lesions, with risk of unnecessary revascularization.
Assuntos
Estenose Coronária/fisiopatologia , Reserva Fracionada de Fluxo Miocárdico/fisiologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio , Estudos Prospectivos , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
BACKGROUND: In patients with normal SPECT but persistent complaints, invasive angiography may exclude obstructive coronary disease. We assessed whether high coronary artery calcium (CAC) scores are associated with increased referral for invasive angiography following normal SPECT. METHODS AND RESULTS: 2286 consecutive patients (mean age 60 ± 12, 39% male) with normal SPECT were assessed. All patients underwent simultaneous CAC scoring. Patients were categorized into four groups based on their CAC score: CAC = 0 (n = 694), CAC 1 to 100 (n = 891), CAC 101 to 400 (n = 368), and CAC >400 (n = 333). The decision to perform angiography was left to the discretion of treating physician. Follow-up angiography was confined to the first 60 days after SPECT. Occurrence of MACE (late revascularization, myocardial infarction or death) was recorded. Overall, 100 patients (4.4%) underwent early angiography with increasing rates in higher CAC score groups (1.0%, 2.6%, 8.4%, and 11.7%), respectively, P < .001). A CAC score >400 (OR 3.56, 95% CI 2.19 to 5.77, P < .001) was independently associated with referral to angiography. Similarly, CAC score >400 was an independent predictor for MACE (HR 9.26, 95% CI 5.06 to 16.93). Early angiography did not influence prognosis (HR 1.57, 95% CI 0.91 to 2.73). CONCLUSIONS: CAC scoring impacts clinical decision-making and increases referral rates for invasive angiography after normal SPECT.
Assuntos
Cálcio/metabolismo , Cardiologia/normas , Angiografia Coronária , Coração/diagnóstico por imagem , Imagem de Perfusão do Miocárdio , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Calcinose/patologia , Doença da Artéria Coronariana/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Perfusão , Prognóstico , Encaminhamento e ConsultaRESUMO
BACKGROUND: Correction of motion has become feasible on cadmium-zinc-telluride (CZT)-based SPECT cameras during myocardial perfusion imaging (MPI). Our aim was to quantify the motion and to determine the value of automatic correction using commercially available software. METHODS AND RESULTS: We retrospectively included 83 consecutive patients who underwent stress-rest MPI CZT-SPECT and invasive fractional flow reserve (FFR) measurement. Eight-minute stress acquisitions were reformatted into 1.0- and 20-second bins to detect respiratory motion (RM) and patient motion (PM), respectively. RM and PM were quantified and scans were automatically corrected. Total perfusion deficit (TPD) and SPECT interpretation-normal, equivocal, or abnormal-were compared between the noncorrected and corrected scans. Scans with a changed SPECT interpretation were compared with FFR, the reference standard. Average RM was 2.5 ± 0.4 mm and maximal PM was 4.5 ± 1.3 mm. RM correction influenced the diagnostic outcomes in two patients based on TPD changes ≥7% and in nine patients based on changed visual interpretation. In only four of these patients, the changed SPECT interpretation corresponded with FFR measurements. Correction for PM did not influence the diagnostic outcomes. CONCLUSION: Respiratory motion and patient motion were small. Motion correction did not appear to improve the diagnostic outcome and, hence, the added value seems limited in MPI using CZT-based SPECT cameras.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Movimento (Física) , Imagem de Perfusão do Miocárdio , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Idoso , Cádmio , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reconhecimento Automatizado de Padrão , Padrões de Referência , Reprodutibilidade dos Testes , Respiração , Estudos Retrospectivos , Software , Telúrio , ZincoRESUMO
The impact of coronary artery calcium (CAC) scoring on subsequent changes in cardiovascular medication use in symptomatic patients with normal myocardial perfusion imaging (MPI) findings is not well established. The aim of the current study was to evaluate changes in aspirin and statin use in patients suspected for coronary artery disease after CAC scoring and normal single photon emission computed tomography (SPECT) MPI. METHODS: In the current study, 1,033 stable symptomatic patients without a known history of coronary artery disease with normal SPECT MPI who underwent concomitant CAC scoring were included. All patients had a clinical indication for imaging, mainly atypical chest pain and dyspnea, and were referred from the outpatient clinic of our hospital. Data regarding posttest medication change (either starting or discontinuation of aspirin and statin therapy at the subsequent outpatient visit) were retrospectively collected. Patients were categorized into 4 groups based on their CAC score. RESULTS: Mean age of the patients was 61±11 years and 39% were male. At baseline, 35% of the patients used aspirin and 39% used statin. In patients with CAC scores 0, 1-99, 100-399, and ≥400, aspirin was started in 1%, 4%, 9%, and 9%, respectively, and statin was started in 0%, 7%, 18%, and 24% of the patients, respectively (P<.001). Aspirin was discontinued in 19%, 11%, 7%, and 1% and statin was discontinued in 8%, 6%, 2%, and 0% (P<.001) of the patients in these respective CAC score categories. After correction for differences in risk factors and baseline medication use, increased CAC was independently associated with posttest aspirin (odds ratio 4.6, 11.2, and 27.1 for CAC scores 1-99, 100-399, and ≥400, respectively; P<.001) and statin use (odds ratio 4.4, 19.4, and 60.9 for CAC scores 1-99, 100-399, and ≥400, respectively; P<.001). CONCLUSIONS: Higher CAC scores are associated with the initiation of aspirin and statin therapy in patients with normal SPECT MPI. In patients with lower CAC scores, discontinuation of cardioprotective medication is more likely. CAC score is independently associated with posttest statin and aspirin use.
Assuntos
Calcinose/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/tratamento farmacológico , Vasos Coronários/diagnóstico por imagem , Aspirina/uso terapêutico , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
OBJECTIVES: To investigate the impact of left bundle branch block (LBBB) on sequential single photon emission computed tomography (SPECT)/ CT imaging starting with stress-first SPECT. METHODS: Consecutive symptomatic low- to intermediate-risk patients without a history of coronary artery disease (CAD) referred for SPECT/CT were included from an observational registry. If stress SPECT was abnormal, additional rest SPECT and, if feasible, coronary CT angiography (CCTA) were acquired. RESULTS: Of the 5,018 patients, 218 (4.3 %) demonstrated LBBB. Patients with LBBB were slightly older than patients without LBBB (65±12 vs. 61±11 years, p<0.001). Stress SPECT was more frequently abnormal in patients with LBBB (82 % vs. 46 %, p<0.001). After reviewing stress and rest images, SPECT was normal in 43 % of the patients with LBBB, compared to 77 % of the patients without LBBB (p<0.001). Sixty-four of the 124 patients with LBBB and abnormal stress-rest SPECT underwent CCTA (52 %), which could exclude obstructive CAD in 46 of the patients (72 %). CONCLUSIONS: Sequential SPECT/CT imaging starting with stress SPECT is not the optimal imaging protocol in patients with LBBB, as the majority of these patients have potentially false-positive stress SPECT. First-line testing using CCTA may be more appropriate in low- to intermediate-risk patients with LBBB. KEY POINTS: ⢠Stress-first SPECT imaging is attractive if many patients demonstrate normal stress perfusion. ⢠The majority of left bundle branch block patients have abnormal stress-first SPECT. ⢠Coronary CT excluded obstructive CAD in many LBBB patients with abnormal SPECT. ⢠Stress-first SPECT imaging is not the optimal imaging protocol in LBBB patients. ⢠In LBBB patients imaging with initial coronary CT may be more appropriate.
Assuntos
Bloqueio de Ramo/diagnóstico , Doença da Artéria Coronariana/complicações , Vasos Coronários/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Bloqueio de Ramo/etiologia , Bloqueio de Ramo/fisiopatologia , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Teste de Esforço , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
BACKGROUND: Performing both single photon emission computerized tomography (SPECT) and coronary computed tomography angiography (CCTA) in patients suspected for coronary artery disease (CAD) leads to increased radiation exposure. We evaluated the need for additional imaging and following implications for radiation exposure of a sequential SPECT/computed tomography (CT) algorithm. METHODS AND RESULTS: 5018 consecutive patients without history of CAD were referred for stress-first SPECT and coronary artery calcium (CAC) scoring. If stress SPECT was abnormal, additional rest SPECT and, if feasible, CCTA were acquired. Stress SPECT was normal in 2617 patients (52%). CCTA was not performed in 1289 of the 2401 patients referred for additional imaging (54%), mainly because of severe CAC (47%) or fast/irregular heart rate (22%). 642 patients with abnormal SPECT underwent CCTA, which excluded significant CAD in 378 patients (59%). Mean radiation dose was 4.5 ± 0.3 mSv for stress-only imaging and 13.2 ± 3.3 mSv for additional imaging (P < 0.001). CONCLUSIONS: Half of the patients do not require additional imaging in our sequential SPECT/CT algorithm, which is accompanied with low radiation exposure. CCTA cannot be performed in half of the patients who undergo additional imaging because of (relative) contra-indications. CCTA is able to correct for false-positive SPECT findings in our algorithm.
Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Uso Excessivo dos Serviços de Saúde/estatística & dados numéricos , Exposição à Radiação/prevenção & controle , Exposição à Radiação/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/estatística & dados numéricos , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Países Baixos/epidemiologia , Prevalência , Fatores de Risco , Técnica de Subtração/estatística & dados numéricos , Revisão da Utilização de Recursos de SaúdeRESUMO
PURPOSE: Single photon emission computed tomography (SPECT) myocardial perfusion imaging has proven to have prognostic importance in patients with suspected stable coronary artery disease (CAD). The recently introduced ultrafast cadmium zinc telluride (CZT)-based gamma cameras have been associated with less equivocal findings and more normal interpretations, allowing stress-only imaging to be performed more often. However, it is yet unclear whether normal stress-only CZT SPECT has comparable prognostic value as normally interpreted stress-only conventional SPECT. METHODS: The study population consisted of 1,650 consecutive patients without known CAD with normal stress-only myocardial perfusion results with either conventional (n = 362) or CZT SPECT (n = 1,288). The incidence of major adverse cardiac events (MACE, all-cause death, non-fatal myocardial infarction and/or coronary revascularization) was compared between the conventional SPECT and CZT SPECT groups. Multivariable analyses using the Cox model were used to adjust for differences in baseline variables. RESULTS: Patients scanned with CZT were less often male (33 vs 39 %), had less often hypercholesterolaemia (41 vs 50 %) and had more often a family history of CAD (57 vs 49 %). At a median follow-up time of 37 months (interquartile range 28-45 months) MACE occurred in 68 patients. The incidence of MACE was 1.5 %/year in the CZT group, compared to 2.0 %/year in the conventional group (p = 0.08). After multivariate analyses, there was a trend to a lower incidence of MACE in the CZT SPECT group (hazard ratio 0.61, 95 % confidence interval 0.35-1.04, p = 0.07). CONCLUSION: The prognostic value of normal stress-only CZT SPECT is at least comparable and may be even better than that of normal conventional stress SPECT.
Assuntos
Cádmio , Doença da Artéria Coronariana/diagnóstico por imagem , Imagem de Perfusão do Miocárdio , Compostos Radiofarmacêuticos , Telúrio , Tomografia Computadorizada de Emissão de Fóton Único , Zinco , Idoso , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE: Recently introduced ultrafast cardiac SPECT cameras with cadmium zinc telluride-based (CZT) detectors may provide superior image quality allowing faster acquisition with reduced radiation doses. Although the level of concordance between conventional SPECT and invasive fractional flow reserve (FFR) measurement has been studied, that between FFR and CZT-based SPECT is not yet known. Therefore, we aimed to assess the level of concordance between CZT SPECT and FFR in a large patient group with stable coronary artery disease. METHODS: Both invasive FFR and myocardial perfusion imaging with a CZT-based SPECT camera, using Tc-tetrofosmin as tracer, were performed in 100 patients with stable angina and intermediate grade stenosis on invasive coronary angiography. A cut-off value of <0.75 was used to define abnormal FFR. RESULTS: The mean age of the patients was 64 ± 11 years, and 64 % were men. SPECT demonstrated ischaemia in 31 % of the patients, and 20 % had FFR <0.75. The concordance between CZT SPECT and FFR was 73 % on a per-patient basis and 79 % on a per-vessel basis. Discordant findings were more often seen in older patients and were mainly (19 %) the result of ischaemic SPECT findings in patients with FFR ≥ 0.75, whereas only 8 % had an abnormal FFR without ischaemia as demonstrated by CZT SPECT. CONCLUSION: Only 20 - 30 % of patients with intermediate coronary stenoses had significant ischaemia as assessed by CZT SPECT or invasive FFR. CZT SPECT showed a modest degree of concordance with FFR, which is comparable with previous results with conventional SPECT. Further investigations are particularly necessary in patients with normal SPECT and abnormal FFR, especially to determine whether these patients should undergo revascularization.
Assuntos
Tomografia Computadorizada por Emissão de Fóton Único de Sincronização Cardíaca , Doença da Artéria Coronariana/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Imagem de Perfusão do Miocárdio , Idoso , Cádmio , Feminino , Câmaras gama , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organofosforados , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Telúrio , ZincoRESUMO
PURPOSE: High coronary artery calcium (CAC) scores are associated with a high likelihood of ischaemia and obstructive coronary disease. Myocardial perfusion imaging (MPI) is a key investigation to determine the need for revascularization. However, the value of MPI in presence of extensive CAC has so far only been demonstrated in asymptomatic patients, whereas its value in symptomatic patients remains largely unclear. Therefore, we studied the impact of MPI in symptomatic patients with a CAC score ≥ 1,000. METHODS: We included 282 patients (mean age 69 ± 9 years, 63% men) without a history of coronary disease with suspected stable angina referred for MPI and with a CAC score ≥ 1,000. On follow-up at 18 months invasive angiography, coronary revascularization, nonfatal myocardial infarction and death were recorded. RESULTS: MPI was normal in 54 %, equivocal in 10 % and abnormal in 37 % (fixed defect 9 % and ischaemia 28 %) of patients. More abnormal MPI findings were observed in men, smokers and those with even higher CAC scores. During follow-up, 1 patient (with nonischaemic MPI) died from a cardiac cause, 1 patient (with ischaemic MPI) suffered a myocardial infarction and 92 patients (33 %) underwent revascularization. Ischaemia on MPI was a strong predictor of coronary revascularization (odds ratio 13.1; 95 % CI 7.1-24.3; p < 0.001). CONCLUSION: Ischaemia on MPI is observed in approximately 30 % of patients with a CAC score ≥ 1,000, and is a strong predictor of coronary revascularization. However, nonischaemic MPI does not exclude revascularization, and patients with persisting complaints should be considered for invasive angiography.
Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Imagem de Perfusão do Miocárdio , Idoso , Cateterismo Cardíaco , Doença da Artéria Coronariana/terapia , Feminino , Humanos , Masculino , Revascularização Miocárdica , Prognóstico , Encaminhamento e Consulta , Estudos Retrospectivos , Risco , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
BACKGROUND: False-negative myocardial perfusion imaging (MPI) can by due to left main (LM) or three-vessel disease causing "balanced ischemia". However, so far prevalence of LM or three-vessel-disease in patients with normal MPI is unclear. We assessed prevalence, location, and extent of significant coronary artery disease (CAD) in patients with normal MPI. METHODS: Between 2006 and 2010, 256 patients with normal MPI who had invasive angiography because of persisting or worsening of the same initial symptoms were studied. Significant CAD was defined as stenosis > 70% or LM > 50%. RESULTS: A total of 93 patients (36%) had significant CAD. Significant CAD was observed more frequently in males, higher age and those with typical angina complaints. Significant LM disease was present in 7%, three-vessel disease in 10%, two-vessel disease in 22%, and single vessel disease (not left main) in 61%. In those with single vessel disease, the location was the LAD in 40%, the RCA in 30%, and the LCX in 30%. CONCLUSIONS: In selected patients with normal MPI, one-third had significant CAD. The majority of these patients had single vessel disease (not left main). LM or three vessel disease, causing "balanced ischemia", is a less common cause of false-negative MPI.
Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Compostos Organofosforados , Compostos de Organotecnécio , Tomografia Computadorizada de Emissão de Fóton Único/estatística & dados numéricos , Distribuição por Idade , Idoso , Reações Falso-Negativas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio , Países Baixos , Prevalência , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Medição de Risco , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Distribuição por SexoRESUMO
PURPOSE: Coronary artery calcium (CAC) scores influence the pre-test likelihood of ischemia in patients undergoing myocardial perfusion imaging (MPI). We investigated the influence of CAC score knowledge on the visual interpretation of MPI in patients referred for the diagnostic work-up of suspected coronary artery disease. METHODS: We retrospectively analyzed symptomatic patients who were referred for MPI. For the current analysis, we selected 151 patients who underwent SPECT MPI with simultaneous CAC scoring. MPI was visually interpreted in two separate sessions, first without and then with knowledge of the CAC score. MPI results were classified into four groups: normal, fixed defects, ischemia, and equivocal. RESULTS: Mean age of the patients was 64 ± 11 years, 56% were male. Without knowledge of the CAC score MPI was evaluated as normal in 36%, compared to 40% with knowledge of the CAC score (P = 0.636). Overall, the addition of the CAC score changed the interpretation of MPI in 56 patients (37%). Importantly, the frequency of equivocal MPI interpretations decreased from 21% without knowledge of CAC score to 9% with knowledge of CAC score (P = 0.002). CONCLUSIONS: Knowledge of the CAC score has a major impact on the interpretation of MPI, increasing the interpretative certainty.
Assuntos
Algoritmos , Calcinose/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodos , Feminino , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de DoençaRESUMO
PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.
Assuntos
Calcinose/diagnóstico , Calcinose/epidemiologia , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/epidemiologia , Interpretação de Imagem Assistida por Computador/métodos , Imagem de Perfusão do Miocárdio/estatística & dados numéricos , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Reprodutibilidade dos Testes , Medição de Risco , Sensibilidade e EspecificidadeRESUMO
PURPOSE: The new ultrafast cardiac single photon emission computed tomography (SPECT) cameras with cadmium-zinc-telluride (CZT)-based detectors are faster and produce higher quality images as compared to conventional SPECT cameras. We assessed the need for additional imaging, total imaging time, tracer dose and 1-year outcome between patients scanned with the CZT camera and a conventional SPECT camera. METHODS: A total of 456 consecutive stable patients without known coronary artery disease underwent myocardial perfusion imaging on a hybrid SPECT/CT (64-slice) scanner using either conventional (n = 225) or CZT SPECT (n = 231). All patients started with low-dose stress imaging, combined with coronary calcium scoring. Rest imaging was only done when initial stress SPECT testing was equivocal or abnormal. Coronary CT angiography was subsequently performed in cases of ischaemic or equivocal SPECT findings. Furthermore, 1-year clinical follow-up was obtained with regard to coronary revascularization, nonfatal myocardial infarction or death. RESULTS: Baseline characteristics were comparable between the two groups. With the CZT camera, the need for rest imaging (35 vs 56%, p < 0.001) and additional coronary CT angiography (20 vs 28%, p = 0.025) was significantly lower as compared with the conventional camera. This resulted in a lower mean total administered isotope dose per patient (658 ± 390 vs 840 ± 421 MBq, p < 0.001) and shorter imaging time (6.39 ± 1.91 vs 20.40 ± 7.46 min, p < 0.001) with the CZT camera. After 1 year, clinical outcome was comparable between the two groups. CONCLUSION: As compared to images on a conventional SPECT camera, stress myocardial perfusion images acquired on a CZT camera are more frequently interpreted as normal with identical clinical outcome after 1-year follow-up. This lowers the need for additional testing, results in lower mean radiation dose and shortens imaging time.
Assuntos
Cádmio , Imagem de Perfusão do Miocárdio/métodos , Doses de Radiação , Telúrio , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Zinco , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio/instrumentação , Prognóstico , Estudos Retrospectivos , Estresse Fisiológico , Fatores de Tempo , Tomografia Computadorizada de Emissão de Fóton Único/instrumentaçãoRESUMO
Recently introduced PET systems using silicon photomultipliers with digital readout (dPET) have an improved timing and spatial resolution, aiming at a better image quality than conventional PET (cPET) systems. We prospectively evaluated the performance of a dPET system in patients with cancer, as compared with high-resolution (HR) cPET imaging. Methods: After a single 18F-FDG injection, 66 patients underwent dPET and cPET imaging in randomized order. We used HR reconstructions (2 × 2 × 2 mm voxels) for both scanners and determined SUVmax, SUVmean, lesion-to-background ratio (LBR), metabolic tumor volume (MTV), and lesion diameter in up to 5 18F-FDG-positive lesions per patient. Furthermore, we counted the number of visible and measurable lesions on each PET scan. Two nuclear medicine specialists determined, in a masked manner, the TNM score from both image sets in 30 patients referred for initial staging. For all 66 patients, these specialists separately evaluated image quality (4-point scale) and determined the scan preference. Results: We included 238 lesions that were visible and measurable on both PET scans. For 27 patients, we found 37 additional lesions on dPET (41%) that were unmeasurable (n = 14) or invisible (n = 23) on cPET. Mean (±SD) SUVmean, SUVmax, LBR, and MTV on cPET were 5.2 ± 3.9, 6.9 ± 5.6, 5.0 ± 3.6, and 2,991 ± 13,251 mm3, respectively. On dPET, SUVmean, SUVmax, and LBR increased by 24%, 23%, and 27%, respectively (P < 0.001) whereas MTV decreased by 13% (P < 0.001), compared with cPET. Visual analysis showed TNM upstaging with dPET in 13% of the patients (4/30). dPET images also had higher scores for quality (P = 0.003) and were visually preferred in most cases (65%). Conclusion: dPET improved the detection of small lesions, upstaged the disease, and produced images that were visually preferred to those from HR cPET. More studies are necessary to confirm the superior diagnostic performance of dPET.Keywords: digital PET; conventional PET; FDG PET; lesion detection; cancer imaging.
Assuntos
Neoplasias/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias/patologia , Estudos ProspectivosRESUMO
BACKGROUND: A high SUV-reproducibility is crucial when different PET scanners are in use. We evaluated the SUV variability in whole-body FDG-PET scans of patients with suspected or proven cancer using an EARL-accredited conventional and digital PET scanner. In a head-to-head comparison we studied images of 50 patients acquired on a conventional scanner (cPET, Ingenuity TF PET/CT, Philips) and compared them with images acquired on a digital scanner (dPET, Vereos PET/CT, Philips). The PET scanning order was randomised and EARL-compatible reconstructions were applied. We measured SUVmean, SUVpeak, SUVmax and lesion diameter in up to 5 FDG-positive lesions per patient. The relative difference ΔSUV between cPET and dPET was calculated for each SUV-parameter. Furthermore, we calculated repeatability coefficients, reflecting the 95% confidence interval of ΔSUV. RESULTS: We included 128 lesions with an average size of 19 ± 14 mm. Average ΔSUVs were 6-8% with dPET values being higher for all three SUV-parameters (p < 0.001). ΔSUVmax was significantly higher than ΔSUVmean (8% vs. 6%, p = 0.002) and than ΔSUVpeak (8% vs. 7%, p = 0.03). Repeatability coefficients across individual lesions were 27% (ΔSUVmean and ΔSUVpeak) and 33% (ΔSUVmax) (p < 0.001). CONCLUSIONS: With EARL-accredited conventional and digital PET, we found a limited SUV variability with average differences up to 8%. Furthermore, only a limited number of lesions showed a SUV difference of more than 30%. These findings indicate that EARL standardisation works. TRIAL REGISTRATION: This prospective study was registered on the 31th of October 2017 at ClinicalTrials.cov. URL: https://clinicaltrials.gov/ct2/show/NCT03457506?id=03457506&rank=1.
RESUMO
Aims: Single-photon emission computed tomography (SPECT) is widely used for the assessment of coronary artery disease and for decision making regarding revascularization. Concerns about possible false negative findings exist. Our aim was to assess the prevalence of stenoses which are both functionally and anatomically significant in patients referred for invasive fractional flow reserve (FFR) measurements following a normal SPECT, because of persistent complaints. Methods and results: One hundred and thirty-three consecutive patients with normal SPECT were included, with a total of 180 FFR measurements. Luminal narrowing of ≥70% (≥50% for left main) together with a FFR ≤0.80 denoted an anatomically and functionally significant coronary artery stenosis. Separate analyses were performed for FFR <0.75. Mean age of the patients was 65, 40% were women. Sixteen percent of the study population had both anatomically and functionally significant stenoses. Besides the use of nitrate, no differences in baseline characteristics, symptoms, coronary history, or pre-test likelihood could be identified for the prediction of functionally relevant obstructive coronary disease. If FFR <0.75 was used, only 7.5% of the patients had both anatomically and functionally significant stenoses. Conclusion: In patients with normal SPECT who undergo FFR measurements because of persistent complaints, the prevalence of stenoses which are both anatomically and functionally significant is low. This suggests that the prevalence of false-negative SPECT is (very) low.
Assuntos
Angina Estável/diagnóstico , Angina Estável/epidemiologia , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/epidemiologia , Reserva Fracionada de Fluxo Miocárdico/fisiologia , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Análise de Variância , Estudos de Coortes , Angiografia Coronária/métodos , Reações Falso-Negativas , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos , Valores de Referência , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Fatores de TempoRESUMO
BACKGROUND: We evaluated the diagnostic implications of a small-voxel reconstruction for lymph node characterization in breast cancer patients, using state-of-the-art FDG-PET/CT. We included 69 FDG-PET/CT scans from breast cancer patients. PET data were reconstructed using standard 4 × 4 × 4 mm3 and small 2 × 2 × 2 mm3 voxels. Two hundred thirty loco-regional lymph nodes were included, of which 209 nodes were visualised on PET/CT. All nodes were visually scored as benign or malignant, and SUVmax and TBratio(=SUVmax/SUVbackground) were measured. Final diagnosis was based on histological or imaging information. We determined the accuracy, sensitivity and specificity for both reconstruction methods and calculated optimal cut-off values to distinguish benign from malignant nodes. RESULTS: Sixty-one benign and 169 malignant lymph nodes were included. Visual evaluation accuracy was 73% (sensitivity 67%, specificity 89%) on standard-voxel images and 77% (sensitivity 78%, specificity 74%) on small-voxel images (p = 0.13). Across malignant nodes visualised on PET/CT, the small-voxel score was more often correct compared with the standard-voxel score (89 vs. 76%, p < 0.001). In benign nodes, the standard-voxel score was more often correct (89 vs. 74%, p = 0.04). Quantitative data were based on the 61 benign and 148 malignant lymph nodes visualised on PET/CT. SUVs and TBratio were on average 3.0 and 1.6 times higher in malignant nodes compared to those in benign nodes (p < 0.001), on standard- and small-voxel PET images respectively. Small-voxel PET showed average increases in SUVmax and TBratio of typically 40% over standard-voxel PET. The optimal SUVmax cut-off using standard-voxels was 1.8 (sensitivity 81%, specificity 95%, accuracy 85%) while for small-voxels, the optimal SUVmax cut-off was 2.6 (sensitivity 78%, specificity 98%, accuracy 84%). Differences in accuracy were non-significant. CONCLUSIONS: Small-voxel PET/CT improves the sensitivity of visual lymph node characterization and provides a higher detection rate of malignant lymph nodes. However, small-voxel PET/CT also introduced more false-positive results in benign nodes. Across all nodes, differences in accuracy were non-significant. Quantitatively, small-voxel images require higher cut-off values. Readers have to adapt their reference standards.