RESUMO
Myocardial somatostatin PET uptake is observed not only in most patients with acute myocarditis (AM) but also in some oncology patients referred for routine somatostatin PET. This raises concerns about the specificity of somatostatin PET for detecting myocarditis. The current study aims to identify factors associated with the detection of myocardial uptake on somatostatin PET scans recorded for oncology indications and differential PET criteria that characterize myocardial uptake in AM patients. Methods: We analyzed factors associated with the detection of myocardial [68Ga]Ga-DOTATOC uptake in 508 [68Ga]Ga-DOTATOC PET scans from 178 patients, performed for confirmed or suspected oncologic disease (Onc-PET) and PET criteria that could differentiate myocardial [68Ga]Ga-DOTATOC uptake in 31 patients with MRI-ascertained AM (AM-PET) from that in the Onc-PET group. Results: Significant myocardial uptake was detected in 137 (26.9%) Onc-PET scans and was independently associated with somatostatin analog treatment (exp(ß), 0.805; 95% CI, 0.728-0.890; P < 0.001) and age (exp(ß), 1.005; 95% CI, 1.001-1.009; P = 0.012). A comparable model was selected for predicting the myocardial-to-blood SUVmax ratio using somatostatin analog treatment (P < 0.001) and history of coronary artery disease (P = 0.022). Myocardial uptake was detected in 12.9% (25/193) of Onc-PET scans from patients treated with somatostatin analogs but in 43.4% (59/136) of untreated patients over the median age of 64 y. Myocardial uptake was apparent in all 31 AM-PET scans, with volume and intensity of uptake dramatically higher than in the 137 Onc-PET scans showing myocardial uptake. A myocardial-to-blood SUVmax ratio threshold of 2.20 provided a sensitivity of 87% (27/31) and a specificity of 88% (44/50) for differentiating myocardial uptake between the AM-PET group and an Onc-PET group restricted to patients with clinical characteristics comparable to those of patients in the AM-PET group (≤64 y of age, no coronary artery disease history, and no somatostatin agonists). A myocardial uptake volume threshold of 18 cm3 provided comparable diagnostic accuracy (sensitivity, 84% [26/31]; specificity, 94% [47/50]). Conclusion: Myocardial uptake was detected in 26.9% of somatostatin PET scans recorded for oncology indications. This rate was decreased by somatostatin analog treatments and increased in older individuals. However, somatostatin PET scans, analyzed with the quantitative criterion of uptake intensity or volume, are able to identify AM and to differentiate it from myocardial uptake of other origins.
Assuntos
Miocardite , Miocárdio , Octreotida , Somatostatina , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Aguda , Transporte Biológico , Diagnóstico Diferencial , Coração/diagnóstico por imagem , Miocardite/diagnóstico por imagem , Miocardite/metabolismo , Miocárdio/metabolismo , Neoplasias/diagnóstico por imagem , Neoplasias/metabolismo , Octreotida/análogos & derivados , Octreotida/metabolismo , Octreotida/farmacocinética , Compostos Organometálicos/farmacocinética , Compostos Organometálicos/metabolismo , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/farmacocinética , Estudos Retrospectivos , Somatostatina/análogos & derivados , Somatostatina/metabolismoRESUMO
BACKGROUND: The outcome of breast cancer (BrCa) women monitored by low-dose equilibrium radionuclide angiography (ERNA) remains challenging to predict. AIM: This study aims to determine whether heart rate (HR)/blood pressure (BP) ratio-based indexes, previously confirmed to predict outcomes of various diseases, also predict BrCa-therapy-related cardiotoxicity and survival. METHODS: Predictors of cardiotoxicity and survival were determined among pre-therapy variables, including shock index ([SI HR/systolic BP) and age-adjusted SI (ASI), in a female BrCa cohort with normal baseline ERNA-left ventricular ejection fraction (LVEF). RESULTS: We included 274 women with a median age of 54.8 (interquartile range: 45.5-65.4) years, 271 treated with anthracyclines and 96 with trastuzumab. During a median follow-up of 25.9 (18.6-33.5) months, 31 women developed cardiotoxicity (LVEF: <50% and ≥10% drop from baseline), and 25 died. Baseline ASI was a multivariate predictor (p < 0.001) of (i) cardiotoxicity, in association with trastuzumab treatment (p = 0.010), and LV end-diastolic volume (p = 0.001) and (ii) survival, in association with metastasis (p < 0.001) and estimated glomerular filtration rate (p = 0.008). Cardiotoxicity poorly impacted survival (p = 0.064). The 36-month cardiotoxicity and mortality rates were markedly higher for patients in the upper half of baseline ASI values (ASI: >30 years min-1.mmHg-1, 16.5% and 20.7%, respectively) than in the lower half (7.6% and 4.5%, respectively, both p < 0.05). CONCLUSIONS: In BrCa women with normal baseline ERNA-LVEF, HR/BP ratio-based indexes unmask hemodynamic profiles associated with increased cardiotoxicity risk and decreased survival, highlighting the need for a comprehensive assessment of cardiac- and vascular-related risks in BrCa women monitored by ERNA. CONDENSED ABSTRACT: In a cohort of 274 women BrCa women who were monitored by ERNA for potentially cardiotoxic drugs (anthracyclines or trastuzumab) and who had no history of cardiac disease and a normal left ventricular ejection fraction before treatment, baseline indexes based on HR/BP ratios unmask hemodynamic profiles strongly associated with an increased risk of cardiotoxicity and subsequently decreased survival. Although further validations in other cohorts are needed, these findings highlight the need for a more comprehensive assessment of the cardiac- and vascular-related risk in BrCa women monitored by ERNA.
Assuntos
Neoplasias da Mama , Cardiotoxicidade , Trastuzumab , Humanos , Feminino , Pessoa de Meia-Idade , Neoplasias da Mama/tratamento farmacológico , Idoso , Trastuzumab/efeitos adversos , Hemodinâmica/efeitos dos fármacos , Antraciclinas/efeitos adversos , Volume Sistólico/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Imagem do Acúmulo Cardíaco de Comporta , Fatores de RiscoRESUMO
ABSTRACT: The tomoscintigraphy monitoring of 177Lu-prostate-specific membrane antigen (PSMA) treatment may be helpful for quality control and predicting therapeutic response. Furthermore, the drawbacks of relatively low image quality and extended recording times can be overcome by new CZT-cameras providing fast, high-quality, whole-body recordings. Although still requiring further larger-scale confirmation, the current case report demonstrates that these CZT-cameras have the potential to provide straightforward and comprehensive 177Lu-PSMA treatment monitoring, that is, <20-minute whole-body tomoscintigraphy recording, tumor activities concordant with those from 68Ga-PSMA PET, and no requirement for any additional tracer injection.
Assuntos
Lutécio , Radioisótopos , Masculino , Humanos , Lutécio/uso terapêutico , Controle de QualidadeRESUMO
BACKGROUND: This study assesses a first-line left ventricular ejection fraction (LVEF) monitoring provided by an ultra-low-dose equilibrium radionuclide angiography (ERNA) in breast cancer women treated with potentially cardiotoxic drugs and analyzes patient outcome based on the ERNA results. METHODS: Breast cancer women treated with anthracyclines, followed or not by trastuzumab, were monitored using ERNA with a high-sensitivity CZT-camera. Calibrated LVEF measurements were obtained with an almost threefold reduction of radiation doses and 10-min recording times. RESULTS: During a mean 24 ± 6 months follow-up, 552 ERNAs with a mean effective dose of 2.3 ± 0.6 mSv were performed in 195 women, among whom 22 (11%) presented both ERNA criteria of cardiotoxicity (LVEF < 50% and > 10% drop from baseline; Tox + group), 35 (18%) only one criterion (Tox ± group), and 138 (71%) neither (Tox - group). This ERNA-based classification correlated with trastuzumab-anthracycline treatment (p = 0.001), prior cardiovascular disease (p = 0.018), and cardiac outcome, with a 30-month survival with no cardiotoxicity-driven drug regimen changes of 97 ± 2% in Tox -, 60 ± 13% in Tox ± and 36 ± 13% in Tox + (p < 0.001) groups. CONCLUSION: First-line detection of breast cancer therapy-related cardiotoxicity by ultra-low-dose ERNA provides consistent results, confirming the excellent cardiac outcome for the greatest majority of women with no ERNA cardiotoxicity criteria.
Assuntos
Neoplasias da Mama , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Volume Sistólico , Imagem do Acúmulo Cardíaco de Comporta , Função Ventricular Esquerda , Trastuzumab/uso terapêutico , Cardiotoxicidade , Antibióticos Antineoplásicos , Antraciclinas/uso terapêuticoRESUMO
Somatostatin receptors are overexpressed by inflammatory cells but not by cardiac cells, under normal conditions. This study assesses the detection of acute myocarditis by the ECG-triggered digital-PET imaging of somatostatin receptors (68Ga-DOTATOC-PET), as compared to Cardiac Magnetic Resonance (CMR) imaging, which is the reference diagnostic method in this setting. METHODS: Fourteen CMR-defined acute myocarditis patients had a first 15-minutes ECG-triggered 68Ga-DOTATOC PET recording, 4.4 ± 3.0 days from peak troponin, and 10 had a second 4.3 ± 0.3 months later. Myocardial/blood SUVmax ratio was analyzed relative to the normal upper limit of 2.18, which had been previously determined from oncology 68Ga-DOTATOC-PET recordings of patients with a similar age range as the myocarditis patients. RESULTS: An increased myocardial 68Ga-DOTATOC uptake relative to blood activity was invariably observed during the acute phase. SUVmax ratio exceeded 2.18 in all patients during the acute phase but also in 3/10 patients at 4-months, at a time when there were no more signs of active inflammation on CMR. A residual myocardial 68Ga-DOTATOC uptake was still observed on all gated-PET cine loops at 4-months. CONCLUSION: These preliminary results suggest that 68Ga-DOTATOC ECG-triggered digital-PET may be as sensitive as CMR at detecting myocarditis during the acute phase and more sensitive at later stages.
Assuntos
Miocardite , Compostos Organometálicos , Humanos , Receptores de Somatostatina , Radioisótopos de Gálio , Tomografia por Emissão de Pósitrons/métodos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , EletrocardiografiaRESUMO
BACKGROUND: This study aims to determine whether the suppression of myocardial FDG uptake and detection of infectious endocarditis (IE) may be enhanced when FDG-PET is repeated on the next day while maintaining patients on a ketogenic diet in the interim. METHODS: Seventeen patients with definite IE underwent FDG-PET investigations both after a conventional metabolic preparation (> 12-hour fast after a low-carbohydrate evening meal) and a subsequent 12-hour extension of the low-carbohydrate diet followed by an additional > 12-hour fast. RESULTS: Plasma biomarkers showed increased ketogenic metabolism between the two FDG-PET scans. A myocardial FDG uptake persisted on the 1st PET in 9 patients (53%) for whom myocardial FDG uptake decreased significantly on the 2nd PET (SUVmax: 6.05 ± 3.25 vs 4.32 ± 3.47, P = 0.021), resulting in an enhancement in the diagnostic confidence of IE in 6 cases. These enhancements were not documented in the 8 patients exhibiting a total suppression of myocardial FDG uptake on the 1st PET. CONCLUSIONS: Better suppression of myocardial uptake and enhanced detection of IE may be achieved when an FDG-PET, showing an incomplete suppression of the myocardial FDG uptake, is repeated as soon as the next day, while maintaining patients on a ketogenic diet in the interim.
Assuntos
Dieta Cetogênica , Endocardite , Humanos , Fluordesoxiglucose F18 , Compostos Radiofarmacêuticos , Tomografia por Emissão de Pósitrons , Endocardite/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia ComputadorizadaRESUMO
PURPOSE: Our study assesses the routine reporting of exercise ischemia using very low-dose exercise-first myocardial perfusion SPECT in a large number of patients and under real-life conditions, by evaluating correlations with the subsequent routine reporting of coronary stenosis by angiography and with factors that predict ischemia. METHODS: Data from 13,126 routine exercise MPI reports, from 11,952 patients (31% women), using very low doses of sestamibi and a high-sensitivity cardiac CZT camera, were extracted to assess the reporting of significant MPI-ischemia (> 1 left ventricular segment), to determine the MPI normalcy rate in a group with < 5% pretest probability of coronary artery disease (CAD) (n = 378), and to assess the ability of MPI to predict a > 50% coronary stenosis in patients with available coronary angiography reports in the 3 months after the MPI (n = 713). RESULTS: The median effective patient dose was 2.51 [IQR: 1.00-4.71] mSv. The normalcy rate was 98%, and the MPI-ischemia rate was independently predicted by a known CAD, the male gender, obesity, and a < 50% LV ejection fraction, ranging from 29.5% with all these risk factors represented to 1.5% when there were no risk factors. A > 50% coronary stenosis was significantly predicted by MPI-ischemia, less significantly for mild (odds ratio [95% confidence interval]: 1.61 [1.26-1.96]) than for moderate-to-severe MPI-ischemia (4.05 [3.53-4.57]) and was also impacted by having a known CAD (2.17 [1.83-2.51]), by a submaximal exercise test (1.48 [1.15-1.81]) and being ≥ 65 years of age (1.43 [1.11-1.76]). CONCLUSION: Ischemia detected using a very low-dose exercise-first MPI protocol in a large-scale clinical cohort and under real-life routine conditions is a highly significant predictor for the subsequent reporting of coronary stenosis, although this prediction is enhanced by other variables. This weakly irradiating approach is amenable to being repeated at shorter time intervals, in target patient groups with a high probability of MPI-ischemia.
Assuntos
Doença da Artéria Coronariana , Estenose Coronária , Imagem de Perfusão do Miocárdio , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Teste de Esforço/métodos , Feminino , Humanos , Masculino , Imagem de Perfusão do Miocárdio/métodos , Perfusão , Tomografia Computadorizada de Emissão de Fóton Único/métodosAssuntos
Câmaras gama , Imagem de Perfusão do Miocárdio/instrumentação , Obesidade Mórbida/diagnóstico por imagem , Compostos Radiofarmacêuticos/administração & dosagem , Tecnécio Tc 99m Sestamibi/administração & dosagem , Imagem Corporal Total/instrumentação , Adulto , Cádmio , Feminino , Humanos , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio/métodos , Obesidade Mórbida/complicações , Telúrio , Tomografia Computadorizada por Raios X , ZincoRESUMO
The whole-body absolute quantification of Lu-DOTATATE therapy was achieved using a high-speed 360° CZT SPECT/CT system. Twelve high-resolution swelling detectors may be positioned close to patients, providing a high-count sensitivity that is particularly advantageous for the low-count rate conditions of Lu imaging. After initially validating Lu quantification on phantom, serial whole-body SPECT/CT acquisitions of only 20 minutes were obtained for a 70-year-old woman treated by Lu-DOTATATE injections for a metastatic recurrence of a pancreatic neuroendocrine tumor. The progressive decrease in tumor uptake between the consecutive Lu-DOTATATE injections could be quantified, and thereby the corresponding dosimetry changes could be estimated.
Assuntos
Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/radioterapia , Octreotida/análogos & derivados , Compostos Organometálicos/uso terapêutico , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Imagem Corporal Total/instrumentação , Idoso , Estudos de Viabilidade , Feminino , Humanos , Tumores Neuroendócrinos/patologia , Octreotida/uso terapêutico , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/radioterapia , Imagens de Fantasmas , RadiometriaRESUMO
PURPOSE: To determine whether the left ventricular ejection fractions (EFs), measured on a high-sensitivity CZT single photon emission computed tomography (SPECT)-camera with a 70% reduction in recording times and a prevention of EF overestimation through an additional count-calibration, are concordant with reference EF from planar radionuclide angiography (2D-RNA). METHODS: An additional 10-minute CZT-SPECT recording was performed in patients referred to 2D-RNA for cardiomyopathy (n = 23) or chemotherapy monitoring (n = 50) with an in vivo red blood cell labeling with 850 MBq [Formula: see text]. The EF, obtained from CZT-SPECT with 100% (SPECT100) or 30% (SPECT30) projection times and with a SPECT-count calibration on the 2D-RNA counts of corresponding cavity volumes, were compared to EF from 2D-RNA. RESULTS: Strong and equivalent relationships were documented between the EF from 2D-RNA and the calibrated EF from SPECT100 (y = 0.89x + 6.62; R2 = 0.87) and SPECT30 (y = 0.87x + 8.40; R2 = 0.85), and the mean EF from SPECT100 (54% ± 15%) and SPECT30 (53% ± 16%) were close to that from 2D-RNA (55% ± 15%). However, upward shifts in these mean values were documented in the absence of count calibration for both SPECT100 (60% ± 18%) and SPECT30 (60% ± 18%). CONCLUSION: Left ventricular EF may be determined on a high-sensitivity CZT-camera, a 70% reduction in injected activities, and an additional count-calibration for further enhancing the concordance with 2D-RNA values.
Assuntos
Angiografia , Cardiomiopatias/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Neoplasias/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Antineoplásicos/uso terapêutico , Cádmio , Calibragem , Simulação por Computador , Eritrócitos/efeitos dos fármacos , Feminino , Câmaras gama , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Estudos Prospectivos , Angiografia Cintilográfica , Volume Sistólico , Telúrio , Função Ventricular Esquerda , ZincoRESUMO
This prospective randomized study assessed myocardial perfusion imaging with the high-sensitivity D.SPECT cadmium-zinc-telluride camera in a forward-leaning bikerlike position, which may potentially lower diaphragmatic attenuation and reduce breathing-related cardiac motion, in a manner comparable to the prone position proposed with other SPECT cameras. Methods: Patients referred for a stress-rest 99mTc-sestamibi protocol and positioned in the biker position, with the chest leaning forward on the D.SPECT camera-head at 35° from vertical, had an additional resting D.SPECT recording in the supine position (n = 40) or in the sitting position with the back rearward at 30° from vertical (n = 40). Segments with attenuation artifacts were defined as those with less than 65% uptake but with strictly normal contractility at gated SPECT and no defect reversibility from stress images. Results: The biker position was associated with lower heart-to-detector distances than the supine or sitting positions (both P < 0.001); lower cardiac motion amplitudes, assessed on panograms, than the supine position (P < 0.001); and fewer segments with attenuation artifacts than the supine position (on average, 1.10 ± 1.01 vs. 1.90 ± 1.74, P = 0.010) or the sitting position (0.75 ± 0.93 vs. 1.38 ± 1.60, P = 0.011). Conclusion: Myocardial perfusion images from D.SPECT are enhanced for patients positioned in a forward-leaning bikerlike position comparatively to sitting or supine positions, with a notably lower rate of attenuation artifacts.
Assuntos
Ciclismo , Cádmio , Coração/diagnóstico por imagem , Postura , Telúrio , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Zinco , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio , Estudos Prospectivos , Postura Sentada , Decúbito DorsalRESUMO
PURPOSE: Gamma-cameras, with Cadmium-Zinc-Telluride (CZT) detectors, allow to perform myocardial perfusion imaging (MPI) with limited injected activities and recorded times. This study aimed at determining whether the routine assessment of left ventricular (LV) function with such limited counts protocols compares well with reference values from cardiac MRI. METHODS: The study included patients who have undergone cardiac MRI and an MPI routinely planned on a CZT camera with a low-dose protocol (120 MBq of Sestamibi for stress and 360 MBq at rest for 75 kg body weight), while targeting the recording of only 500 myocardial kcounts in order to limit the recording times (<10 minutes for stress, <4 minutes for rest). SPECT images were reconstructed with a method maintaining rather high spatial (8 mm) and temporal (16 frames/cycle) resolutions. RESULTS: Seventy-six patients were included, and mean effective dose was 3.5 ± 1.7 mSv for the total MPI protocol. Correlations between CZT-SPECT and MRI were good to excellent for ejection fraction (r 2 = 0.77), end-diastolic (r 2 = 0.88) and end-systolic (r 2 = 0.93) volumes, and the analysis of segmental contractility correlated well between the two techniques (kappa score = 0.72 ± 0.02). CONCLUSION: LV function, assessed on a CZT camera with low injected activities and limited recording times, correlates well with the reference assessment from cardiac MRI.
Assuntos
Cádmio , Imageamento por Ressonância Magnética , Imagem de Perfusão do Miocárdio , Telúrio , Tomografia Computadorizada de Emissão de Fóton Único , Função Ventricular Esquerda , Zinco , Idoso , Peso Corporal , Feminino , Câmaras gama , Coração/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Sístole , Tecnécio Tc 99m Sestamibi , Fatores de TempoRESUMO
PURPOSE OF THE REPORT: This study aimed at assessing an original low-dose dual-isotope procedure in which the abnormal stress Tc-99m Sestamibi SPECT is followed by rest Tl-201 SPECT, along with a head-to-head comparison with a single-isotope procedure. METHODS AND RESULTS: One hundred two patients, referred for a low-dose stress-SPECT with Sestamibi (123 ± 20 MBq) on a CZT camera and for whom a rest Sestamibi SPECT was warranted, had an additional Tl-201 rest-SPECT (52 ± 5 MBq) between stress and rest Sestamibi SPECT recordings. Tl-201 images were processed for spill-over and scatter corrections, and uptake differences with stress Sestamibi SPECT were analyzed: (1) for rest acquisitions from Tl-201 (dual-isotope procedure) and from Sestamibi (single-isotope procedure) and (2) in segments for which a diagnosis of ischemia, infarct, or normal perfusion was achieved. Mean effective dose was 8.3 mSv for dual-isotope but would decrease to 5.7 mSv for an expected rate of 37% of patients for whom rest-SPECT is not warranted. After a further background correction of Tl-201 images, the rest-stress difference in myocardial uptake was equivalent between dual- and single-procedures for identifying ischemic segments (respective areas-under-curves: 0.83 ± 0.03 and 0.81 ± 0.03). CONCLUSION: This original dual-isotope procedure provides acceptable radiation doses and consistent results, as compared with conventional single-isotope.
Assuntos
Imagem de Perfusão do Miocárdio/métodos , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Cádmio , Humanos , Doses de Radiação , Telúrio , ZincoAssuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Fatores Imunológicos/uso terapêutico , Arterite de Takayasu/tratamento farmacológico , Aortografia/métodos , Angiografia por Tomografia Computadorizada , Humanos , Angiografia por Ressonância Magnética , Masculino , Tomografia por Emissão de Pósitrons , Indução de Remissão , Índice de Gravidade de Doença , Arterite de Takayasu/diagnóstico por imagem , Arterite de Takayasu/imunologia , Arterite de Takayasu/cirurgia , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
Type I glycogen storage disease (GSD) is a rare autosomal recessive disorder caused by glucose-6-phosphatase deficiency. We report herein the particular pattern provided by FDG PET imaging in a 33-year-old patient with type Ib GSD. PET images yielded evidence of a pulmonary infectious focus as well as of: (1) a dramatically enlarged liver leading to a high global FDG uptake, (2) increased bone marrow activity, (3) splenomegalia leading to a high global spleen uptake, (4) a diffuse enhancement in muscle FDG uptake.
Assuntos
Doença de Depósito de Glicogênio Tipo I/diagnóstico por imagem , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto , Humanos , MasculinoRESUMO
PURPOSE: Effective doses of 14 mSv or higher are currently being attained in patients having stress and rest myocardial perfusion imaging (MPI) single photon emission computed tomography (SPECT) performed on the same day with conventional protocols. This study aimed to assess the actual reduction in effective doses as well as diagnostic performances for MPI routinely planned with: (1) high-sensitivity cadmium zinc telluride (CZT) cameras, (2) very low injected activities and (3) a stress-first protocol where the normality of stress images may lead to avoiding rest imaging. METHODS: During a 1-year period, 2,845 patients had MPI on a CZT camera, a single-day stress-first protocol and low injected activities (120 MBq of (99m)Tc-sestamibi at stress for 75 kg body weight and threefold higher at rest). The ability to detect > 50% coronary stenosis was assessed in a subgroup of 149 patients who also had coronary angiography, while the normalcy rate was assessed in a subgroup of 128 patients with a low pretest likelihood of coronary artery disease (<10%). RESULTS: Overall, 33% of patients had abnormal MPI of which 34% were women and 34% were obese. The mean effective doses and the percentage of exams involving only stress images were: (1) 3.53 ± 2.10 mSv and 37% in the overall population, (2) 4.83 ± 1.56 mSv and 5% in the subgroup with angiography and (3) 1.96 ± 1.52 mSv and 71 % in the low-probability subgroup. Sensitivity and global accuracy for identifying the 106 patients with coronary stenosis were 88 and 80%, respectively, while the normalcy rate was 97 %. CONCLUSION: When planned with a low-dose stress-first protocol on a CZT camera, MPI provides high diagnostic performances and a dramatic reduction in patient radiation doses. This reduction is even greater in low-risk subgroups with high rates of normal stress images, thus allowing the mean radiation dose to be balanced against cardiac risk in targeted populations.