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Objective To observe the influence of different energy windows of the medium-energy general-purpose(MEGP)collimator on image quality,so as to optimize the energy window of yttrium-90(90Y)bremsstrahlung SPECT imaging.Methods 90Y bremsstrahlung spectrum was acquired,and the sensitivity,percentage of the source counts in useful field of view(S/FOV%)and signal-to-background ratio(S/B)of 90Y bremsstrahlung SPECT imaging at MEGP under different energy windows were compared.Results The energy spectrum of 90Y bremsstrahlung was a continuous curve,with the peak of 76.2 keV with MEGP collimator.The images obtained with MEGP collimator were clear,and no significant differences of S/FOV%nor S/B was found between 10%and 20%window width groups(both P＞0.05),but the sensitivities of the latter was higher than the former(P＜0.05).The sensitivity of 70-90 keV images was relatively high,while the S/FOV%and S/B had decreased.The S/FOV%and S/B of images ranging from 40-60 keV were high,but the sensitivity was low.Images acquired with 100 keV±20%showed fairly high sensitivity,S/FOV%and S/B,which was 69.73%,0.62 and 1.64,respectively.Conclusion When performing 90Y bremsstrahlung SPECT with MEGP collimator,the image quality at 20%window width was better than at 10%window width,and 100 keV±20%showed fairly high sensitivity and not significantly decreased S/FOV%and S/B.
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Objective:To investigate the prognostic value of myocardial flow reserve (MFR) measured by SPECT myocardial blood flow (MBF) quantitative technique in patients with intermediate stenoses of coronary arteries.Methods:From September 2019 to May 2021, patients with intermediate stenoses (50% to 80%) identified by invasive coronary angiography in Fuwai Hospital, Chinese Academy of Medical Sciences, Fuwai Center China Cardiovascular Hospital, and TEDA International Cardiovascular Hospital were prospectively included. All patients underwent a one-day rest/stress SPECT myocardial perfusion imaging (MPI) and SPECT MBF quantification. The radioactivity distribution of each segment of the MPI bullseye polar maps were obtained according to the standard 5-point method to obtain the summed stress score (SSS) and the summed difference score (SDS) to determine the existence of abnormality. ROC curve analysis was used to obtain the optimal prognostic cut-off value for MFR. The primary endpoint was defined as cardiovascular endpoint events. Survival and prognostic analyses were conducted by Kaplan-Meier method and Cox proportional hazard models. The difference of AUCs was analyzed by Delong test.Results:A total of 314 patients (194 males, 120 females; age (59.4±8.6) years) were enrolled. Over a median follow-up duration of 754 (range: 628-914) d, 54 patients had endpoint events. ROC curve showed that the prediction ability of MFR was significantly better than that of conventional MPI (AUCs: 0.713 and 0.512; z=3.76, P<0.001). The optimal prognostic cut-off value for MFR to predict endpoint events in patients with intermediate stenoses was 2.04. Cox multivariate analysis showed that MFR (hazard ratio ( HR)=0.434, 95% CI: 0.282-0.669, P<0.001) was an independent predictor of endpoint events in patients with intermediate stenoses. Kaplan-Meier survival analysis showed that the prevalence of endpoint events in patients with MFR≤2.04 was significantly higher than that in patients with MFR>2.04 (25.4%(43/169) vs 7.6%(11/145); χ2=21.27, P<0.001). Conclusion:The MFR measured by SPECT MBF quantitative technique has an independent predictive value for cardiovascular endpoint events in patients with intermediate stenoses.
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Objective:To investigate the value of 99Tc m-hydrazinonicotinamide (HYNIC)-prostate specific membrane antigen(PSMA) SPECT/CT imaging in biochemical recurrence of prostate cancer (PCa). Methods:From January 2018 to March 2023, 112 patients with biochemical recurrence of PCa (age (72.6±6.1) years) who underwent 99Tc m-HYNIC-PSMA SPECT/CT imaging in Henan Provincial People′s Hospital were retrospectively analyzed. According to the level of prostate specific antigen (PSA), patients were divided into 0.2 μg/L<PSA≤1 μg/L group, 1 μg/L<PSA≤2 μg/L group, and PSA>2 μg/L group. According to the Gleason score, patients were divided into Gleason score≥8 group and Gleason score <8 group. The detection rate between groups was analyzed by χ2 test, and the difference of the PSA level between groups was compared by Mann-Whitney U test. Results:PSMA imaging was positive in 77 cases and negative in 35 cases, with the detection rate of 68.8%(77/112). The detection rates of local recurrence, lymph node metastasis, bone metastasis and lung metastasis were 8.9%(10/112), 43.8%(49/112), 28.6%(32/112) and 0.9%(1/112), respectively. The detection rates of 0.2 μg/L<PSA≤1 μg/L, 1 μg/L<PSA≤2 μg/L and PSA>2 μg/L groups were 44.7%(21/47), 8/12 and 90.6%(48/53), respectively ( χ2=24.44, P<0.001). The detection rates of Gleason score ≥8 group and <8 group were 76.4%(55/72) and 55.0%(22/40) ( χ2=5.47, P=0.032); the PSA level between the two groups was statistically different (3.11(0.75, 5.91) and 0.84(0.44, 2.92) μg/L; z=-2.99, P=0.003). Of the patients with PSMA positive imaging, 84.4%(65/77) changed their treatment regimen and 15.6%(12/77) continued to observe or maintain the original treatment plan. Of the patients with PSMA negative imaging, 40.0%(14/35) changed the treatment plan, 51.4%(18/35) continued to observe or maintain the original treatment plan, and 8.6%(3/35) discontinued the original treatment because no tumor metastasis was found. Conclusion:99Tc m-HYNIC-PSMA SPECT/CT imaging can provide reference for the lesion detection, treatment decision-making and follow-up observation of biochemical recurrence of PCa.
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La evaluación de la perfusión miocárdica con SPECT combina una prueba de esfuerzo (ergometría o estrés farmacológico) junto a imágenes de perfusión con radioisótopos. Este estudio es útil para establecer el diagnóstico de enfermedad arterial coronaria, estratificar el riesgo de infarto y tomar decisiones terapéuticas. Un resultado normal aporta un alto valor predictivo negativo, es decir, una muy baja probabilidad de que el paciente presente eventos cardiovasculares. El hallazgo de signos de isquemia en la ergometría podría poner en jaque el valor predictivo negativo de una perfusión normal. En presencia de este resultado, el paso siguiente es evaluar los predictores de riesgo en la ergometría, el riesgo propio del paciente en función de los antecedentes clínicos y el puntaje cálcico coronario, cuando este se encuentra disponible. Ante la presencia concomitante de otros marcadores de riesgo se sugiere completar la evaluación con un estudio anatómico.El uso de nuevas tecnologías podría mejorar la precisión en la predicción de eventos. (AU)
Assessment of myocardial perfusion with SPECT combines a stress test (ergometry or pharmacological stress) with radioisotope perfusion imaging. This test is helpful to diagnose coronary artery disease, stratify the risk of heart attack, and make therapeutic decisions. A normal result provides a high negative predictive value; therefore, the probability of cardiovascular events is very low. Signs of ischemia on an ergometry could jeopardize the negative predictive value of normal perfusion. In this clinical setting, the next step is to evaluate the risk predictors in the stress test, the individual risk based on the clinical history, and the coronary calcium score when available. Given the simultaneous presence of other risk markers,completing the evaluation with an anatomical study is suggested. The use of new technologies could improve the accuracy of event prediction. (AU)
الموضوعات
Humans , Tomography, Emission-Computed, Single-Photon , Ergometry , Myocardial Ischemia/diagnostic imaging , Risk Assessment/methods , Myocardial Perfusion Imaging , Myocardial Infarction/prevention & control , Prognosis , Survival , Coronary Artery Disease/diagnostic imaging , Sensitivity and Specificity , Exercise Test , Clinical Decision-Makingالملخص
Objective:To explore the potential clinical value of 99Tc m-methoxyisobutylisonitrile(MIBI) SPECT/CT muscle imaging in the diagnosis of cervical dystonia (CD). Methods:From January 2021 to April 2022, 50 patients with CD (14 males, 36 females; age (45.8±12.5) years) who were treated in Second Affiliated Hospital of Soochow University were prospectively included. The 99Tc m-MIBI SPECT/CT muscle imaging results of 400 pieces of muscle (bilateral sternocleidomastoid, musculus scapulae, splenius capitis and musculus trapezius; each of 100 pieces) in 50 patients were analyzed and divided into the dystonic muscle group and normal muscle group according to the electromyography (EMG). Toronto western spasmodic torticollis rating scale (TWSTRS) score, SUV max and target-to-background ratio (TBR) of single superficial cervical muscle and total cervical muscle, and EMG diagnosis results were obtained before botulinum toxin injection. ROC curves of SUV max and TBR of dystonic muscles were constructed to determine AUCs and the difference was compared by Delong test. Differences of SUV max and TBR between 2 groups were analyzed by Mann-Whitney U test. Spearman rank correlation analysis was used to analyze the correlation of SUV max, TBR and TWSTRS scores of total cervical muscle. Results:There were 205 pieces of muscle in dystonic muscle group and 195 pieces of muscle in normal muscle group. The uptake of 99Tc m-MIBI in dystonic muscle was significantly increased in CD patients, and the non-whole uptake of 99Tc m-MIBI was increased in some dystonic muscles, which was manifested as uneven uptake of the whole muscle. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of visual analysis were 95.12%(195/205), 75.90%(148/195), 85.75%(343/400), 85.58%(195/242) and 93.67%(148/158), respectively. There were significant differences of SUV max (1.74(1.42, 2.12) vs 0.92(0.81, 0.99)) and TBR (2.55(1.92, 3.27) vs 1.44(1.22, 1.73)) between the dystonic muscle group and the normal muscle group ( z value: -15.29, -12.69, both P<0.001). The diagnostic efficiency of SUV max in dystonic muscle was better than TBR (AUC: 0.942 vs 0.867; z=5.03, P<0.001). SUV max, TBR and TWSTRS score in the neck muscles of patients with CD showed positive correlation ( rs values: 0.44, 0.45, both P<0.001). Conclusion:99Tc m -MIBI SPECT/CT muscle imaging is a good diagnostic method for dystonic muscle in patients with CD.
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Objective:To evaluate the efficacy of balloon pulmonary angioplasty (BPA) in chronic thromboembolic pulmonary hypertension (CTEPH) using 99Tc m-macroaggregated albumin (MAA) pulmonary perfusion tomography imaging. Methods:Twenty-five patients (4 males, 21 females; age (56.5±12.3) years) with CTEPH who underwent BPA from January 2017 to April 2020 in Beijing Chaoyang Hospital, Capital Medical University were enrolled retrospectively. Effect of BPA on the improvement of pulmonary lobe/pulmonary segment perfusion was analyzed, and the proportions of improved and unimproved pulmonary lobe/pulmonary segment perfusion by BPA were calculated. The percentages of perfusion defect scores (PPDs%) of lung perfusion tomography imaging before BPA and after 4-6 times BPA were compared and analyzed (paired t test). The correlations between PPDs% and mean pulmonary artery pressure (mPAP) before BPA and after BPA were analyzed respectively, and the correlation between decreased percentage of PPDs% and decreased percentage of mPAP after BPA were also analyzed (Pearson correlation analysis). Results:Among 150 lobes of 25 patients, 96.00%(144/150) lobes showed perfusion abnormalities before BPA. After BPA, 11.11%(16/144) showed complete improvement, 57.64%(83/144) showed partial improvement, and 31.25%(45/144) showed no improvement. Among 450 pulmonary segments of 25 patients, 62.44%(281/450) showed perfusion abnormalities before BPA. After BPA, 30.60%(86/281), 37.37%(105/281), 32.03%(90/281) showed complete, partial and no improvement, respectively. The post-BPA PPDs% was significantly lower than that of pre-BPA ((39.08±10.88)% vs (57.88±10.46)%; t=10.40, P<0.001). The post-BPA mPAP was significantly lower than that of pre-BPA ((32.36±10.57) vs (49.08±10.23) mmHg; 1 mmHg=0.133 kPa; t=10.25, P<0.001). There was no significant correlation between PPDs% and mPAP either before BPA ( r=0.01, P=0.953) or after BPA ( r=0.27, P=0.199), but there was a positive correlation between the changes of PPDs% and mPAP ( r=0.40, P=0.045). Conclusions:BPA can significantly improve the pulmonary perfusion and reduce mPAP in CTEPH patients. Pulmonary perfusion tomography imaging can be used to evaluate the efficacy of BPA in CTEPH.
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Objective:To evaluate the relationship between regional coronary flow reserve (CFR) obtained from cadmium-zinc-telluride SPECT(CZT SPECT) myocardial functional perfusion imaging (MFPI) and invasive fractional flow reserve (FFR) measured during coronary angiography (CAG) and its clinical value in guiding coronary interventions.Methods:Forty-two patients (30 males, 12 females, age (63.3±9.8) years) who completed CZT SPECT MFPI in the First Affiliated Hospital of Nanjing Medical University from June 2022 to September 2022 and underwent CAG within 3 months were included retrospectively. The concordance of CFR and FFR for diagnosing myocardial ischemia (CFR<2.0 and FFR<0.8) was calculated at the vascular level. The diagnostic efficacy of coronary stenosis≥70% for decreased myocardial blood flow (CFR<2.0) was calculated. Kappa test was used to analyze the data. Results:A total of 126 major coronary arteries were identified in 42 patients, of which 30(23.8%) had a CFR<2.0 by CZT SPECT and 33(26.2%) had stenosis≥70% in CAG. A total of 32 coronary vessels were performed with MFPI CFR and FFR measurements, of which 6 were both decreased and 21 were both normal, so the concordance rate was 84.4%(27/32)( Kappa=0.612, P<0.001). Among 33 coronary vessels with stenosis≥70%, 13 were with CFR≥2.0. Among 30 coronary vessels with CFR<2.0, 10 were with stenosis<70%. When using stenosis≥70% to diagnose CFR decreasing, the sensitivity was 66.7%(20/30), specificity was 86.5%(83/96), positive predictive value was 60.6%(20/33), negative predictive value was 89.2%(83/93), and accuracy was 81.7%(103/126). Conclusions:The concordance between CFR and FFR for the diagnosis of myocardial ischemia is good. Nearly 1/3 of the coronary arteries with decreased CFR have stenosis<70%, whereas nearly 40% of the coronary arteries with stenosis≥70% are not result in myocardial ischemia. Regional CFR determined by CZT SPECT may have potentially significant clinical value in the diagnosis of coronary artery disease and decision-making of coronary intervention.
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Objective:To establish the normal reference value of left ventricular function parameters by cadmium-zinc-tellurium (CZT) SPECT stress gated myocardial perfusion imaging (G-MPI) in low-likelihood of stable coronary artery disease (SCAD).Methods:From March 2022 to August 2022, 348 consecutive SCAD patients (146 males, 202 females, age (58±10) years) who underwent exercise or pharmacological stress G-MPI (CZT SPECT) in Beijing Anzhen Hospital, Capital Medical University were retrospectively recruited. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), and left ventricular ejection fraction (LVEF) were acquired using quantitative gated SPECT (QGS) analysis. EDV and ESV were corrected by body surface area (BSA) to obtain EDV index (EDVI) and ESV index (ESVI), respectively. Independent-sample t test, one-way analysis of variance and Mann-Whitney U test were used for data analysis. The influences of EDV, ESV, EDVI, ESVI and LVEF were analyzed by multiple regressions for linear models. Results:There were 314 patients with low-likelihood of SCAD (128 males, 186 females, age (58±10) years) and 34 normal controls (18 males, 16 females, age (55±10) years). There were no significant differences of basic clinical characteristics and left ventricular function parameters in different genders between 2 groups ( z values: from -1.74 to -0.02, t values: from -1.16 to 1.17, all P>0.05). Using the 95% CI as the cut-off value for left ventricular function parameters in patients with a low-likelihood of SCAD, the upper limits of EDV, ESV, EDVI and ESVI in females and males were 84 and 111 ml, 30 and 44 ml, 47 and 54 ml/m 2, 17 and 21 ml/m 2, respectively, and the lower limit of LVEF in females and males were 58% and 55%, respectively. In the low-likelihood of SCAD group, the EDV ((58±13) vs (77±17) ml) and ESV ((16±7) vs (26±9) ml) of females were smaller than those of males ( t values: 10.65, 10.35, both P<0.001), while LVEF of females was higher than that of males ((72±7)% vs (67±6)%; t=-6.23, P<0.001). However, there were no significant differences in left ventricular function parameters among different age groups with the same gender ( F values: 0.12-2.19, all P>0.05). Based on multiple regression for linear models, the primary predictors of EDV, ESV and LVEF were gender and weight ( β values: from -0.380 to 0.358, all P<0.05). Conclusions:Normal reference values of left ventricular function parameters are established by CZT SPECT stress G-MPI in low-likelihood of SCAD patients. Left ventricular EDV and ESV of females are smaller than those of males, while LVEF of females is higher than that of males. The influence of gender on left ventricular function parameters should be considered in clinical practice.
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Objective:To study the value of myocardial perfusion imaging (MPI) and coronary flow reserve (CFR) combined with coronary artery calcium score (CACS) in the diagnosis of obstructive coronary artery disease (CAD).Methods:From January 2019 to December 2020, 96 confirmed or suspective CAD patients (65 males, 31 females; age: 30-81 years) who completed rest/stress MPI, CFR and CACS defection in Fuwai Central China Cardiovascular Hospital were retrospectively analyzed. Coronary angiography (CAG) was used as the diagnostic standard to calculate the sensitivity and accuracy of MPI, CFR and MPI/CFR combined with CACS in the diagnosis of CAD. The χ2 test was used to compare the diagnostic efficiency of different methods. Results:The diagnostic sensitivity of MPI was 76.06%(54/71), and the accuracy was 75.00%(72/96), while the sensitivity increased to 97.18%(69/71; χ2=13.67, P<0.001) and the accuracy increased to 87.50%(84/96; χ2=4.92, P=0.020) with significant differences after combined with CACS. The sensitivity and accuracy of CFR were 91.55%(65/71)and 87.50%(84/96), which increased to 97.18%(69/71; χ2=2.12, P=0.137) and 89.58%(86/96; χ2=0.21, P=0.411) with no significant differences after combined with CACS. The sensitivity of MPI in the diagnosis of three-vessel CAD was 70.00%(21/30), which increased to 100%(30/30; χ2=7.75, P=0.004) after combined with CACS; while the sensitivity of MPI combined with CACS in the diagnosis of single-vessel and double-vessel CAD were not significantly improved ( χ2 values: 3.29, 1.51, P values: 0.114, 0.416). Conclusion:The combination of MPI and CACS can significantly improve the diagnostic efficiency of CAD, contributed by the improvement of the diagnostic sensitivity in three-vessel disease; whereas the diagnostic efficiency of CFR for CAD is not significantly improved after combined with CACS.
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Objective:To evaluate the value of 99Tc m-methoxyisobutylisonitrile(MIBI) SPECT/CT imaging for the identification of dystonic muscles in patients with primary cervical dystonia (PCD). Methods:A total of 10 patients with PCD (3 males, 7 females, age (47.3±9.9) years) and 10 healthy subjects (4 males, 6 females, age (43.5±9.4) years; control group) between August 2019 and October 2021 in China-Japan Friendship Hospital were enrolled prospectively. All subjects underwent 99Tc m-MIBI SPECT/CT scan. The SUV max of 8 bilateral representative muscles, including rectus capitis posterior major, obliquus capitis inferior, splenius capitis, semispinalis, sternocleidomastoid, trapezius, musculus scalenus muscle and levator scapulae were evaluated in control group. In PCD group, muscles with abnormal uptake were determined. ROI was drawn and SUV max was measured. Independent-sample t test was used to analyze the differences of SUV max between normal and abnormal muscles. The detecting rates of neck MRI and SPECT/CT for abnormal muscles were analyzed by χ2 test. Results:Normal muscles of healthy subjects showed mild symmetrical radioactivity distribution, with the SUV max of 1.10±0.19. A total of 60 muscles with abnormal uptake in 10 patients were found, including 7 rectus capitis posterior major, 10 obliquus capitis inferior, 8 splenius capitis, 8 semispinalis, 10 sternocleidomastoid, 5 trapezius, 3 musculus scalenus muscle and 9 levator scapulae. The SUV max of muscles with abnormal uptake was 1.81±0.43, which was higher than that of normal muscles ( t=17.05, P<0.001). Only 30 pieces abnormal hypertrophy muscle were found by neck MRI, and the detecting rate was much lower than that of SPECT/CT (18.75%(30/160) vs 37.50%(60/160); χ2=28.03, P<0.001). Conclusion:99Tc m-MIBI SPECT/CT may be a useful method for identifying dystonic muscles and a guide to precision therapy in patients with PCD.
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ABSTRACT Primary progressive aphasia is a clinical syndrome caused by neurodegeneration of areas and neural networks involved in language, usually in the left hemisphere. The term "crossed aphasia" denotes an acquired language dysfunction caused by a lesion in the ipsilateral hemisphere to the dominant hand. Objective: To describe a case of crossed aphasia in a 60-year-old left-handed patient with a non-fluent variant of primary progressive aphasia diagnosis (age of onset=52), evidenced by a left asymmetry on brain SPECT scan. Methods: Clinical and family history, the Edinburgh Handedness Inventory, Measurement of Functional Activities in Older Adults in the Community, the "Mini-Mental State Examination", the Trail Making Test, the Tower of London, and the Neuropsychological assessment for dementia, and neuroimaging studies were carried out. Results: Neuropsychological assessment showed severe cognitive impairment, especially regarding language. The magnetic resonance imaging showed important signs of cortico-subcortical atrophy, with predominance in the frontal and temporal lobes. The single-photon emission computed tomography scan showed moderate to severe hypoperfusion in the left cerebral hemisphere, including the hippocampus. Conclusion: We described a clinical case of crossed aphasia in a left-handed woman with a non-fluent variant of primary progressive aphasia with asymmetry on brain SPECT, mainly on the left, followed up for seven years.
RESUMO A afasia progressiva primária é uma síndrome clínica causada por uma neurodegeneração de áreas e redes neurais envolvidas na linguagem, geralmente no hemisfério esquerdo. O termo "afasia cruzada" denota uma disfunção adquirida de linguagem causada por uma lesão no hemisfério ipsilateral da mão dominante. Objetivo: Relatamos um caso de afasia cruzada em uma paciente de 60 anos, canhota, com um quadro clínico de afasia progressiva primária variante não fluente (idade de início=52), evidenciada por assimetria no SPECT cerebral à esquerda. Métodos: Foram realizados para o diagnóstico do caso: história clínica e familiar, o Inventário de Dominância de Edinburgh, a Escala de Atividades Funcionais de Pfeffer, o Miniexame do Estado Mental, o Teste das Trilhas, o Teste da Torre de Londres, a Avaliação Neuropsicológica Adequada às Demências e exames de neuroimagem. Resultados: A avaliação neuropsicológica mostrou comprometimento cognitivo severo, principalmente sobre a linguagem; a ressonância magnética do crânio mostrou sinais de involução córtico-subcortical, com predominância nos lobos frontal e temporal e a cintilografia cerebral por emissão de fóton único mostrou hipoperfusão moderada a severa no hemisfério cerebral esquerdo, incluindo o hipocampo. Conclusão: Registramos um caso clínico de afasia cruzada em uma paciente canhota com afasia progressiva primária variante não fluente com assimetria no SPECT cerebral, principalmente à esquerda, seguida há sete anos.
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RESUMEN Fundamento: los estudios híbridos producen una dosis total de radiación que es resultado de la dosis proveniente del radiofármaco y la emitida por la tomografía computarizada, por eso la optimización es indispensable. Objetivo: evaluar la relación de la dosis de tomografía computarizada con algunos parámetros de calidad de la imagen en protocolos de estudios híbridos. Métodos: para evaluar la calidad de la imagen se emplearon los maniquíes de Catphan y de Livermore en 12 protocolos preestablecidos de un equipo de tomografía por emisión del fotón único Mediso. Los datos de los descriptores de dosis de cada estudio se obtuvieron del cabezal DICOM. Se compararon los parámetros de calidad de imagen clásicos como ruido y la MTF 50 % para el maniquí de Catphan, y otros como la relación contraste ruido, el promedio de números de Hounsfield y su desviación estándar en las regiones de interés de los órganos correspondientes, en el maniquí de Livermore. Se analizó la relación de estos parámetros de calidad con los descriptores de dosis de los diferentes protocolos. Resultados: los parámetros relacionados con la calidad en el maniquí de Catphan no mostraron diferencias significativas (p<0,05) entre los diferentes protocolos para estudios híbridos. Se encontraron diferencias significativas entre los protocolos clínicos con diferentes calidades y el protocolo clínico estándar, para el maniquí antropomórfico, en la desviación estándar de los números de Hounsfield y en la relación contraste ruido (p<0,05). Conclusiones: el estudio de la relación contraste ruido y la desviación de los números de tomografía computarizada en las regiones de interés pueden servir de parámetro cuantitativo para la optimización de dosis en escenario clínico.
ABSTRACT Background: hybrid studies produce a total radiation dose that is the result of the dose imparted by the radiopharmaceutical and that emitted by the computed tomography, therefore optimization is essential. Objective: to evaluate the relationship of the computed tomography dose with some image quality parameters in hybrid study protocols. Methods: to evaluate the image quality, the Catphan and Livermore Phantom were used in 12 pre-established protocols of a Mediso single photon emission tomography equipment. The data for the dose descriptors for each study were obtained from the DICOM head. The classic image quality parameters such as noise and the MTF 50% for the Catphan manikin, and others such as the contrast-noise ratio, the average of Hounsfield numbers and their standard deviation in the regions of interest of the corresponding organs were compared, in Livermore's mannequin. The relationship of these quality parameters with the dose descriptors of the different protocols was analyzed. Results: the quality-related parameters in the Catphan manikin did not show significant differences (p <0.05) between the different protocols for hybrid studies. Significant differences were found between the clinical protocols with different qualities and the standard clinical protocol, for the anthropomorphic manikin, in the standard deviation of the Hounsfield numbers and in the contrast-to-noise ratio (p <0.05). Conclusions: the study of the contrast noise ratio and the deviation of the computed tomography numbers in the regions of interest can serve as a quantitative parameter for the optimization of doses in the clinical setting.
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Objective:To investigate the diagnostic value of myocardial blood flow quantitative imaging with cadmium zinc telluride (CZT) SPECT in patients with high-risk coronary artery disease (CAD).Methods:A total of 148 patients (82 males, 66 females, age: (63.8±8.2) years) who successfully completed CZT SPECT dynamic acquisition and routine SPECT myocardial perfusion imaging (MPI) in TEDA International Cardiovascular Hospital from November 2018 to October 2020 were analyzed retrospectively. According to the results of coronary angiography (CAG), patients were divided into two groups: high-risk CAD group and low-to-medium-risk CAD group. At the case level, quantitative parameters (stress myocardial blood flow (sMBF), rest myocardial blood flow (rMBF) and myocardial flow reserve (MFR)), semi-quantitative parameters (summed stress score (SSS), summed rest score (SRS), summed difference score (SDS) and transient ischemic dilation (TID)) and left ventricular function parameters of two groups were compared. Diagnostic accuracy was evaluated by ROC curve analysis. At the vascular level, the correlation between the degree of coronary artery stenosis and some parameters was analyzed. Mann-Whitney U test, logistic regression, Spearman rank correlation analysis and DeLong test were used for statistical analysis. Results:Case level analysis showed that MFR and sMBF in high-risk CAD group were significantly lower than those in low-to-medium-risk CAD group (1.36(0.87, 1.64) vs 2.74(2.30, 3.33), 1.06(0.69, 1.48) vs 2.50(1.73, 2.95) ml·g -1·min -1; U values: 628.0 and 853.5, both P<0.001). MFR and SDS were independent predictors of high-risk CAD patients (odds ratio ( OR)=0.251(95% CI: 0.136-0.464), P<0.001; OR=1.188(95% CI: 1.026-1.375), P=0.021), and MFR was more capable of predicting high-risk CAD. MFR and sMBF had the highest accuracy in diagnosing high-risk CAD (AUCs: 0.885 and 0.844). Differences of AUCs between MFR and other parameters were statistically significant ( z values: 1.99-6.77, all P<0.05), and the best diagnostic cut-off value was ≤1.83 (sensitivity: 85.90%; specificity: 85.71%). Vascular level analysis showed that MFR and sMBF( R2 values: 0.39 and 0.35, both P<0.001) were negatively correlated with the degree of coronary stenosis, while SSS, SRS and SDS ( R2 values: 0.22, 0.12 and 0.14, all P<0.001) were positively correlated with the degree of coronary stenosis. Conclusion:Compared with conventional SPECT MPI, CZT SPECT myocardial blood flow quantitative imaging has better diagnostic efficacy and clinical value in patients with high-risk CAD.
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Objective:To study the value of ventilation/perfusion single-photon emission computed tomography(SPECT)in combination with a low-dose CT scan(SPECT/CT)in diagnosing pulmonary embolism(PE)in elderly patients.Methods:In this retrospective study, data were collected from 279 patients with suspected PE and undergone SPECT/CT between January 2015 and December 2019 at Beijing Hospital, with 163 aged ≥65(the elderly group)and 116 aged <65(the control group). Based on diagnosis confirmed during follow-up as the final diagnosis, the diagnostic efficacy of ventilation/perfusion SPECT/CT in the two age groups was examined.The diagnostic efficacy of ventilation/perfusion SPECT/CT and age-adjusted D-dimer in the elderly group was also compared.The diagnostic efficacy of ventilation/perfusion SPECT/CT and CT pulmonary angiography(CTPA)was compared in 43 elderly patients who had undergone both ventilation/perfusion SPECT/CT and CTPA.Results:The sensitivity, specificity and accuracy of ventilation/perfusion SPECT/CT in the elderly group were 96.10%(74/77), 91.86%(79/86)and 93.87%(153/163)in the elderly group and 96.43%(27/28), 94.31%(83/88)and 94.83%(110/116)in the control group, respectively, with no statistically significant difference between the two groups( χ2=0.000, 0.409, 0.116, P=1.000, 0.522, 0.733). The sensitivity, specificity and accuracy of age-adjusted D-dimer were 84.42%(65/77), 63.95%(55/86)and 73.62%(120/163), and were significantly different from those of ventilation/perfusion SPECT/CT(all P<0.05). Among 43 elderly patients undergone ventilation/perfusion SPECT/CT and CTPA, 1 was excluded because the diagnosis based on CTPA was uncertain.The diagnostic sensitivity, specificity and accuracy of ventilation/perfusion SPECT/CT were 96.55%(28/29), 92.31%(12/13)and 95.24%(40/42)and those of CTPA were 65.52%(19/29), 92.31%(12/13)and 73.81%(31/42). They had the same specificity, but there were significant differences in sensitivity and accuracy( P=0.012, 0.022). Conclusions:Ventilation/perfusion SPECT/CT has higher accuracy in the diagnosis of PE in elderly patients, compared with CTPA and age-adjusted D-dimer.
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Objective:To investigate the application of different imaging methods of 99Tc m-pyrophosphate (PYP) in the diagnosis and pathological classification of cardiac amyloidosis (CA). Methods:A total of 31 patients (22 males, 9 females, age 21-81(57.2±13.4) years) with suspected CA who underwent 99Tc m-PYP dual-phase scintigraphy (early-phase: 1 h, delay-phase: 2-3 h) and SPECT/CT (1 h) between December 2018 and December 2019 in Peking Union Medical College Hospital were retrospectively included. Taking clinical diagnosis as the standard, the results of visual score (≥2, positive) and semi-quantitative values (heart to contralateral lung (H/CL)≥1.5, positive) of 99Tc m-PYP uptake in dual-phase scintigraphy and SPECT/CT imaging were analyzed. One-way analysis of variance and Bonferroni test were used to analyze the data. Results:Among 31 patients with suspected CA, 15 were clinically diagnosed as CA (5 patients with transthyretin-related CA (ATTR-CA) and 10 patients with light chain CA (AL-CA)) and 16 were diagnosed as non-CA. All 5 patients with ATTR-CA had positive dual-phase scintigraphy and SPECT/CT imaging results. Three out of 10 patients with AL-CA had positive early-phase scintigraphy whereas negative delay-phase scintigraphy and SPECT/CT imaging results. Sixteen patients who were clinically diagnosed as non-CA had negative dual-phase scintigraphy and SPECT/CT imaging results. The sensitivity (5/5), specificity (10/10), positive predictive value (5/5), negative predictive value (10/10) and accuracy (15/15) of delay-phase scintigraphy and SPECT/CT imaging were the same. Among 31 patients, 16 patients carried transthyretin-related (TTR) gene mutation, and 4 of them who clinically diagnosed as variant ATTR (ATTRv) had positive image findings while 12 of them who not clinically diagnosed as CA had negative image findings. There were significant differences in H/CL between ATTR-CA group and AL-CA group in early-phase (2.11±0.24 vs 1.31±0.07) and delay-phase (2.02±0.19 vs 1.30±0.05; F values: 75.41 and 87.15, Bonferroni test, both P<0.01). Conclusions:99Tc m-PYP delay-phase scintigraphy and SPECT/CT have high diagnostic efficiencies in ATTR-CA, helping to determine the pathological classification of CA; while early-phase scintigraphy has false positive results. Moreover, 99Tc m-PYP imaging is helpful to detect CA in patients with TTR gene mutation.
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Objective:To explore the diagnostic value of quantitative 99Tc m-hydrazinonicotinamide(HYNIC)-prostate specific membrane antigen (PSMA) SPECT/CT in patients with prostate cancer. Methods:From November 2018 to March 2021, the data of 56 patients ((69.8±8.0) years) with clinically suspected prostate cancer, who had elevated radioactive uptake in prostate on 99Tc m-HYNIC-PSMA SPECT/CT images in Henan Provincial People′s Hospital, were retrospectively analyzed. According to the pathological results, patients were divided into prostate cancer group ( n=45) and non-prostate cancer group ( n=11). The xSPECT-QUANT software was used to quantitatively analyze the high uptake area of the prostate, and SUV max was measured. The independent-sample t test, Mann-Whitney U test, ROC curve and Spearman correlation analysis were used for data analysis. Results:The prostate cancer group had higher SUV max than non-prostate cancer group (10.79±5.96 vs 3.60±1.27; t=7.43, P<0.001). When SUV max≥6.46, the AUC of prostate cancer was 0.887, with the diagnostic sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 73.3%(33/45), 11/11, 100%(33/33), 47.8%(11/23), 78.6%(44/56), respectively. The SUV max of prostate cancer group was positively correlated with Gleason score ( rs=0.632, P<0.001). The SUV max of 29 patients with Gleason score≥8 was higher than that of 16 patients with Gleason score≤7 ( z=-3.89, P<0.001). There was no statistical difference in PSA level between patients with Gleason score≤ 7 and patients with non-prostate cancer ( z=-1.63, P=0.110), but the SUV max was significantly different ( z=-2.22, P=0.026). The SUV max of 23 patients with metastases was higher than that of 22 patients without metastasis (12.99±5.85 vs 8.50±5.28; t=2.69, P=0.010). ROC analysis showed that the AUC was 0.709; with SUV max≥13.02 as the threshold, the sensitivity for diagnosing prostate cancer metastases was 56.5%(13/23), the specificity was 86.4%(19/22), and the accuracy was 71.1%(32/45). Conclusions:The 99Tc m-HYNIC-PSMA SPECT/CT quantitative analysis is feasible in patients with prostate cancer. SUV max of 99Tc m-HYNIC-PSMA can be used in the diagnosis of prostate cancer, assessment of the malignancy and prediction of metastasis.
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Objective:To evaluate the left ventricular diastolic dyssynchrony (LVDD) and its influencing factors early after acute myocardial infarction (AMI) using phase analysis of SPECT gated myocardial perfusion imaging (GMPI).Methods:Bama miniature swines ( n=16) were subjected to establish AMI models. GMPI was performed before and 1 d after AMI to obtain the extent of myocardial perfusion defect (Extent, %) and left ventricular systolic dyssynchrony (LVSD)/LVDD parameters, namely the phase histogram bandwidth (PBW) and phase standard deviation (PSD). Meanwhile, left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and the ratio of early to late peak mitral diastolic flow (E/A) were obtained by echocardiography. Independent-sample t test, paired t test and Pearson correlation analysis were used to analyze the data. Results:Sixteen AMI swines were successfully created. Compared to baseline, Extent, LVEDV and LVESV significantly increased on 1 d after AMI ( t values: -11.14, -4.55, -6.12, all P<0.001), while LVEF and E/A significantly decreased ( t values: 10.16, 2.18, P<0.001, P=0.046). GMPI showed that the LVDD parameters PBW and PSD increased significantly on 1 d after AMI when compared to those at baseline((142.25±72.06)° vs (33.06±8.98)°, (56.15±26.71)° vs (12.51±5.13)°; t values: -6.11, -6.60, both P<0.001). There were significant differences between LVSD parameters and LVDD parameters (PBW: (109.06±62.40)° vs (142.25±72.06)°, PSD: (44.40±25.61)° vs (56.15±26.71)°; t values: -2.73, -2.20, P values: 0.016, 0.044). LVDD parameters PBW, PSD were negatively correlated with E/A after AMI ( r values: -0.569, -0.566, P values: 0.021, 0.022), and positively correlated with the Extent ( r values: 0.717, 0.634, P values: 0.002, 0.008). The phase analysis of SPECT GMPI to evaluate LVDD showed good intra-observer and inter-observe reproducibility (intraclass correlation coefficient (ICC): 0.953-0.984, all P<0.001). Conclusions:LVDD occurs early on 1 d after AMI, and can reflect left ventricular diastolic dysfunction. The Extent is correlated with LVDD significantly. Phase analysis of SPECT GMPI is an accurate method to evaluate LVDD and left ventricular diastolic function.
الملخص
Objective:To investigate the effect of motion correction (MC) on the calculated values of myocardial blood flow (MBF) and myocardial flow reserve (MFR) based on cadmium-zinc-telluride SPECT (CZT SPECT) images.Methods:Twenty-eight consecutive patients (10 males, 18 females, age: (60.75±11.62) years) with suspected or known coronary artery disease who underwent myocardial perfusion imaging (MPI) with dynamic CZT SPECT between June 2019 and August 2019 in TEDA International Cardiovascular Hospital were retrospectively analyzed. The MBF and MFR during rest imaging and stress imaging were quantitatively analyzed. Corridor 4DM software was used to calculate the stress MBF (sMBF) and MFR of the coronary artery branches and left ventricular (LV) before and after MC. The paired t test and Pearson correlation were used for data analysis. Results:The sMBF and MFR of LV before MC were (0.82±0.49) ml·min -1·g -1 and 1.69±0.68 respectively. After MC the two parameters increased to (1.05±0.64) ml·min -1·g -1 and 2.12±0.77 respectively ( t values: -4.87, -6.01, both P<0.001). The sMBF and MFR in left anterior descending (LAD), left circumflex (LCX), right coronary artery (RCA) and LV before MC were correlated with those after MC ( r values: 0.69-0.96, all P<0.001). If MFR <2.0 was used as the reference of impaired MFR, data before MC showed 19 patients (67.9%, 19/28) had impaired MFR, while 13 patients (46.4%, 13/28) had impaired MFR based on MFR values after MC. Conclusion:For MPI quantitative imaging with CZT SPECT, the calculated values of sMBF and MFR after MC is higher than those before MC, suggesting that MC is helpful to reduce the false positive results which may be caused by the " creep" effect of the heart.
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Objective:To serially characterize the myocardial perfusion, myocardial hibernation and left ventricular (LV) function as well as LV remodeling in progressive coronary artery stenosis in Chinese mini-pigs.Methods:In 8 Chinese mini-pigs (5 males, 3 females; age: 10 months), chronic progression of coronary stenosis and finally occlusion was established using Ameroid constrictor implantation at the 1 cm below the bifurcation of the first diagonal branch of the left anterior descending (LAD) artery. Serial gated 99Tc m-methoxyisobutylisonitrile(MIBI) SPECT/CT, gated 18F-FDG PET/CT imaging and coronary angiography (CAG) were performed before surgery and at the 1st, 4th and 8th week after surgery. Longitudinally, total perfusion defect (TPD), LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), summed motion score (SMS), summed thickening score (STS) and hibernating myocardium (HM) were analyzed. Repeated measures analysis of variance, Kruskal-Wallis rank sum test and Bonferroni correction method were used to analyze data. Results:One mini-pig died of infection after the Ameroid constrictor implantation. In the remaining 7 mini-pigs, TPD was progressively increased with time prolonged (0, 12.0%(0, 33.0%), (41.1±23.7)% and (49.3±24.5)%; H=17.03, P=0.001); Compared with HM before the surgery (100%), HM was gradually reduced from the 1st (21.0%(6.0%, 100%)) to the 4th (18.0%(3.0%, 33.0%)) week after surgery, and then increased to the 8th week after surgery ((23.0±15.4)%; H=13.09, P=0.004), but there was no significant difference between the 1st and 4th week, or between the 4th and 8th week after surgery (both P>0.05 (Bonferroni correction method)). Accordingly, LVEF gradually decreased ((73.7±8.4)%, (63.7±19.1)%, (53.7±14.6)% and (49.9±15.4)%; F=6.22, P=0.004). LVEDV (9.0(6.0, 21.0), (31.4±16.3), (32.9±17.4) and (36.4±17.5) ml; H=8.58, P=0.035)and LVESV ((3.8±3.2), (15.9±15.3), 12.0(10.0, 17.0)and (19.3±10.9) ml; H=10.51, P=0.015) gradually increased. SMS and STS continuously increased as well ( H values: 16.49, 13.33, P values: 0.001, 0.004). Conclusions:With the progression of coronary artery stenosis to occlusion, myocardial perfusion is gradually decreased, while the global and regional LV function, LV remodeling are gradually aggravated, and HM is gradually reduced. After the chronic coronary artery occlusion, myocardial perfusion has a trend to be improved and HM is gradually recovered.
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Objective:To investigate differences in cardiac function and perfusion parameters measured by IQ-SPECT and low energy high-resolution (LEHR)-SPECT, as well as effects of scattering correction (SC) and CT attenuation correction (AC) on myocardial perfusion imaging.Methods:From May 2020 to September 2020, 80 patients (58 males, 22 females, age (57±10) years) who underwent SPECT myocardial perfusion imaging were retrospectively enrolled in Fuwai Hospital. According to the standardized left ventricular end-diastolic diameter of body surface measured by two-dimensional echocardiography, patients were divided into 2 groups: A group ( n=34) with significantly enlarged left ventricle and B group ( n=46) with no significant enlargement of left ventricle. LEHR-SPECT and IQ-SPECT gated myocardial perfusion imaging were performed in all patients. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), summed rest score (SRS) and total perfusion defect (TPD) were measured. Parameters measured by two methods and differences before and after SC and AC were compared by using paired t test and Wilcoxon signed rank test. The correlation was analyzed by Pearson correlation or Spearman rank correlation analyses, and the consistency was analyzed by Bland-Altman analysis. Results:In A group, EDV, EF and SRS measured by IQ-SPECT were significantly lower than those assessed by LEHR-SPECT after SC and AC (EDV: (257±137) vs (276±154) ml, EF: (21±11)% vs (26±13)%, SRS: 17(6, 25) vs 18(8, 28); t values: -2.63, -7.46, z=-2.14, all P<0.05); all parameters measured by LEHR-SPECT and IQ-SPECT had well correlation ( r values: 0.965, 0.969, 0.967, rs values: 0.920, 0.960, all P<0.001) and consistency. In B group, EDV and EF measured by IQ-SPECT were significantly lower than those assessed by LEHR-SPECT after SC and AC (EDV: (96±40) vs (107±39) ml, EF: (46±15)% vs (54±16)%; t values: -6.23, -10.71, both P=0.001); SRS and TPD measured by IQ-SPECT after SC and AC were significantly lower than non-SC and non-AC (SRS: 2(1, 4) vs 5(3, 11), TPD: (3%(1%, 5%) vs 7%(3%, 12%); z values: -4.11, -4.16, both P<0.001); all parameters measured by LEHR-SPECT and IQ-SPECT had well correlation ( r values: 0.956, 0.978, 0.958, rs values: 0.926, 0.944, all P<0.001) and consistency. Conclusions:There are good correlation and consistency of left ventricular function and myocardial perfusion parameters acquired by IQ-SPECT and LEHR-SPECT. Moreover, IQ-SPECT is able to shorten acquisition time, resulting in great potential in clinical application.