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Background: Cardiovascular risk models are based on traditional risk factors and investigations such as imaging tests. External validation is important to determine reproducibility and generalizability of a prediction model. We performed an external validation of t the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT (J-ACCESS) model, developed from a cohort of patients undergoing stress myocardial perfusion imaging., Methods: We included 3623 patients with suspected or known coronary artery disease undergoing stress single-photon emission computer tomography (SPECT) myocardial perfusion imaging at our academic center between January 2001 and December 2019., Results: In our study population, the J-ACCESS model underestimated the risk of major adverse cardiac events (cardiac death, nonfatal myocardial infarction, and severe heart failure requiring hospitalization) within three-year follow-up. The recalibrations and updated of the model slightly improved the initial performance: C-statistics increased from 0.664 to 0.666 and Brier score decreased from 0.075 to 0.073. Hosmer-Lemeshow test indicated a logistic regression fit only for the calibration slope (P = .45) and updated model (P = .22). In the update model, the intercept, diabetes, and severity of myocardial perfusion defects categorized coefficients were comparable with J-ACCESS., Conclusion: The external validation of the J-ACCESS model as well as recalibration models have a limited value for predicting of three-year major adverse cardiac events in our patients. The performance in predicting risk of the updated model resulted superimposable to the calibration slope model., (© 2023. The Author(s).)

Gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs) constitute an ideal target for radiolabeled somatostatin analogs. The theragnostic approach is able to combine diagnosis and therapy by the identification of a molecular target that can be diagnosed and treated with the same radiolabeled compound. During the last years, advances in functional imaging with the introduction of somatostatin analogs and peptide receptor radionuclide therapy, have improved the diagnosis and treatment of GEP-NENs. Moreover, PET/CT imaging with 18 F-FDG represents a complementary tool for prognostic evaluation of patients with GEP-NENs. In the field of personalized medicine, the theragnostic approach has emerged as a promising tool in diagnosis and management of patients with GEP-NENs. The aim of this review is to summarize the current evidence on diagnosis and management of patients with GEP-NENs, focusing on the theragnostic approach.

Background: Arterial hypertension causes cardiac functional and structural alterations. In hypertensive patients without flow-limiting epicardial coronary artery disease, we investigated possible relationships between positron emission tomography/computed tomography-derived myocardial blood flow (MBF) and echocardiographic parameters of left ventricular (LV) performance, including mechano-energetic efficiency indexed for myocardial mass (MEEi)., Methods: Seventy-eight hypertensive patients without flow-limiting epicardial coronary artery disease underwent echocardiography, including MEEi computation, and cardiac positron emission tomography/computed tomography with assessment of MBF/mass ratio at rest and after stress and myocardial flow reserve. The lowest MEEi tertile (MEEi<0.031 mL/s/g) was compared to the merged second and third tertiles (MEEi≥0.031)., Results: Patients in the lowest MEEi tertile were older, had higher systolic blood pressure and body mass index. They also had higher prevalence of LV hypertrophy, whereas lower resting and stress MBF/mass ratio. MEEi was significantly correlated with both resting (r=0.51; P <0.0001) and hyperemic (r=0.54; P <0.0001) MBF/mass ratios, whereas it was not related to myocardial flow reserve. Delta of MBF/mass ratio was lower in the lowest MEEi tertile than in the highest ( P <0.0001). In separate multiple linear regression models, after adjusting for sex, systolic blood pressure, body mass index, prevalence of LV hypertrophy, left atrial volume index, and diuretic therapy, the association between LV MEEi and both hyperemic (beta coefficient=0.44; P =0.003) and resting (beta coefficient=0.35; P =0.008) MBF/mass ratio remained significant., Conclusions: In hypertensive patients without flow-limiting epicardial coronary artery disease, low values of MEEi could detect an early LV dysfunction involving an impairment of both resting and hyperemic MBF/mass ratios. MEEi has the advantage of simpler detection, cheaper costs than positron emission tomography/computed tomography, and a lack of radiation exposure., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT02211365., Competing Interests: Disclosures None.

Myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) assessment with non-invasive techniques represent an important tool to evaluate both coronary artery disease severity and extent. Currently, cardiac positron emission tomography-computed tomography (PET-CT) is the "gold standard" for the assessment of coronary function and provides accurate estimations of baseline and hyperemic MBF and MFR. Nevertheless, due to the high cost and complexity, PET-CT is not widely used in clinical practice. The introduction of cardiac-dedicated cadmium-zinc-telluride (CZT) cameras has renewed researchers' interest on MBF quantitation by single-photon emission computed tomography (SPECT). Indeed, many studies evaluated MPR and MBF measurements by dynamic CZT-SPECT in different cohorts of patients with suspected or overt coronary artery disease. As well, many others have compared the values obtained by CZT-SPECT to the ones by PET-CT, showing good correlations in detecting significant stenosis, although with different and non-standardized cut-off values. Nevertheless, the lack of standardized protocol for acquisition, reconstruction and elaboration makes more difficult to compare different studies and to further assess the real advantages of MBF quantitation by dynamic CZT-SPECT in clinical routine. Many are the issues involved in the bright and dark sides of dynamic CZT-SPECT. They include different type of CZT cameras, different execution protocols, different tracers with different myocardial extraction fraction and distribution, different software packages with different tools and algorithms, often requiring manual post-processing elaboration. This review article provides a clear summary of the state of the art on MBF and MPR evaluation by dynamic CZT-SPECT and outlines the major issues to solve to optimize this technique., Competing Interests: Disclosure of interest The authors declare that this work did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2023 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.)

Background: The purpose of this study was to assess the prognostic value of cardiac 82 Rb positron emission tomography (PET)/computed tomography (CT) imaging in patients with myocardial ischemia of nonobstructive coronary arteries (INOCA)., Methods: We retrospectively evaluated 311 INOCA patients who underwent rest stress 82 Rb PET/CT. Cardiac end points were cardiac death, myocardial infarction, or late coronary revascularization. A parametric survival model was also used to identify how the variables influenced time to event., Results: During a median follow-up of 37 months (range 6-108), 23 (7%) cardiac events occurred. In patients with events total perfusion defect (TPD) was higher and myocardial flow reserve (MFR) lower compared to those without events (both P < .001). At multivariable Cox analysis, increased TPD (i.e., ≥ 5%) and reduced MFR (i.e., < 2) were predictors of events (both P < .001). At Weibull survival analysis, the highest probability of cardiac events and risk acceleration were observed in patients with both increased TPD and reduced MFR. Annualized event rate was higher in patients with reduced MFR compared to those with preserved MFR (P < .001)., Conclusion: In patients with INOCA, the combined evaluation of myocardial perfusion and coronary vascular function by 82 Rb PET/CT is able to identify those at higher risk of cardiac events., (© 2022. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.)

Purpose: In pediatric patients with differentiated thyroid cancer (DTC) we assessed the prognostic value of the 12-month response to therapy after initial treatment with surgery and radioactive iodine (RAI)., Methods: We retrospectively evaluated 94 pediatric patients with DTC, treated with surgery and RAI who were initially classified as low, intermediate or high risk of relapse of disease according to the American Thyroid Association (ATA) guidelines. Twelve months after RAI administration the response to therapy was assessed by serum thyroglobulin (Tg) measurement and neck ultrasound and patients were classified as having excellent response (ER) or no-ER., Results: At the 12 months evaluation, 62 (66%) patients had ER and 32 (34%) no-ER. During a mean follow-up time of 86 months (range 9-517), 19 events occurred (20% cumulative event rate). Events occurred more frequently in younger patients (p < 0.05), in those at ATA intermediate/high risk (p < 0.01) and with a pre-RAI therapy Tg level > 10 ng/mL (p < 0.001), and in those with no-ER (p < 0.001). At multivariate analysis, the evidence of no-ER was the only independent predictor of events., Conclusion: In pediatric patients with DTC, the response to therapy evaluated 12 months after initial treatment has an independent prognostic impact and is able to predict mid-term outcome. Patients with no-ER at 12 months after RAI therapy should be closely followed-up., (© 2023. The Author(s).)

Ischemic heart disease is the leading cause of mortality worldwide. In this context, myocardial viability is defined as the amount of myocardium that, despite contractile dysfunction, maintains metabolic and electrical function, having the potential for functional enhancement upon revascularization. Recent advances have improved methods to detect myocardial viability. The current paper summarizes the pathophysiological basis of the current methods used to detect myocardial viability in light of the advancements in the development of new radiotracers for cardiac imaging.

Myocardial perfusion imaging by nuclear cardiology is widely validated for the diagnosis, risk stratification, and management of patients with suspected or known coronary artery disease. Numerous radiopharmaceuticals are available for single-photon emission computed tomography and PET modalities. Each tracer shows advantages and limitations that should be taken into account in performing an imaging examination. This review aimed to summarize the state-of-the-art radiotracers used for myocardial perfusion imaging and blood flow quantification, highlighting the new technologic advances and promising possible applications., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Second primary malignancies (SPM) are described as any primary, not synchronous, malignancy arising in a different anatomical district, with confirmed histological diagnosis. Age at diagnosis, previous non-thyroidal primary malignancy, and radioactive iodine (RAI) therapy have been proposed as independent risk factors for SPM. RAI therapy is a standard treatment for moderate-high risk differentiated thyroid cancer (DTC), and its effect on the development of SPM has become a critical topic in DTC treatment. The purpose of this retrospective single-center study was to investigate the occurrence and the possible association of non-thyroidal SPM diagnosed after DTC and RAI therapy in a cohort of 1326 consecutive DTC patients referred at our Institution for RAI treatment from 1993 to 2009. Eighty-nine patients with ages ≤ 18 years at the time of DTC diagnosis or with a follow-up of ≤12 months were excluded from the final analysis. All patients underwent a complete clinical and hematological follow-up every 6 months for a minimum of 12 months. During follow-up (mean 89 ± 73 months), 25 patients (2%) had an SPM diagnosis (mean 133 ± 73 months). The most common site of the second malignancy was the breast, accounting for 32% of all SPM, followed by colon-rectal cancer (16%), leukemia, and gynecological and kidney cancer (4%). At Cox univariable regression analysis, age at DTC diagnosis (p < 0.001), age ≥55 years (p < 0.001) and follow-up duration (p < 0.004) were associated with SPM onset, while no significant association was observed with the administered activity of radioiodine. In conclusion, our data suggest that the older a person gets, the more sharply the likelihood of developing additional diseases, such as PMS, increases. Similarly, for follow-up, the more a patient is followed up clinically over time, the higher the risk of new diagnoses increases.

Background: Despite myocardial perfusion imaging (MPI) by cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) camera is largely used in the diagnosis and risk stratification of patients with suspected or known coronary artery disease (CAD), no data are available on the prognostic value of a regional MPI evaluation. We evaluated the prognostic value of regional MPI by the CZT camera in predicting clinical outcomes at the vessel level in patients with available angiographic data., Methods and Results: Five hundred and forty-one subjects with suspected or known CAD referred to 99mTc-sestamibi gated CZT-SPECT cardiac imaging and with available angiographic data were studied. Both regional total perfusion deficit (TPD) and ischemic TPD (ITPD) were calculated separately for each vascular territory (left anterior descending, left circumflex, and right coronary artery). The outcome end points were cardiac death, target vessel-related myocardial infarction, or late coronary revascularization. The prevalence of CAD ≥ 50%, regional stress TPD, and regional ITPD was significantly higher in vessels with events as compared to those without (both P &lt; 0.001). The receiver operating characteristics area under the curve for regional ITPD for the identification of vessel-related events was 0.81 (95% confidence interval 0.75-0.86). An ITPD value of 2.0% provided the best trade-off for identifying the vessel-related event. At multivariable analysis, both CAD ≥ 50% and ITPD ≥ 2.0% resulted in independent predictors of events., Conclusions: Regional myocardial perfusion assessed by the CZT camera demonstrated good reliability in predicting vessel-related events in patients with suspected or known CAD., (© 2022. The Author(s).)

Background: In patients with heart failure (HF) sequential imaging studies have demonstrated a relationship between myocardial perfusion and adrenergic innervation. We evaluated the feasibility of a simultaneous low-dose dual-isotope 123 I/ 99m Tc-acquisition protocol using a cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) camera., Methods and Results: Thirty-six patients with HF underwent simultaneous low-dose 123 I-metaiodobenzylguanidine (MIBG)/ 99m Tc-sestamibi gated CZT-SPECT cardiac imaging. Perfusion and innervation total defect sizes and perfusion/innervation mismatch size (defined by 123 I-MIBG defect size minus 99m Tc-sestamibi defect size) were expressed as percentages of the total left ventricular (LV) surface area. LV ejection fraction (EF) significantly correlated with perfusion defect size (P < .005), innervation defect size (P < .005), and early (P < .05) and late (P < .01) 123 I-MIBG heart-to-mediastinum (H/M) ratio. In addition, late H/M ratio was independently associated with reduced LVEF (P < .05). Although there was a significant relationship (P < .001) between perfusion and innervation defect size, innervation defect size was larger than perfusion defect size (P < .001). At multivariable linear regression analysis, 123 I-MIBG washout rate (WR) correlated with perfusion/innervation mismatch (P < .05)., Conclusions: In patients with HF, a simultaneous low-dose dual-isotope 123 I/ 99m Tc-acquisition protocol is feasible and could have important clinical implications., (© 2022. The Author(s).)

Background: Prevention and development of diagnostic and therapeutic techniques reduced morbidity and mortality for coronary artery disease (CAD). In this context, the cardiovascular risk assessment for major adverse cardiac events (MACE) at 2-year (CRAX2MACE) model for prediction of 2-year major adverse cardiac events was developed. We performed an external validation of this model., Methods: We included 1003 patients with suspected CAD undergoing stress-rest single-photon emission computed tomography myocardial perfusion imaging at our academic center between March 2015 and April 2019., Results: Considering the occurrence of MACE (death from any cause, acute myocardial infarction, or late coronary revascularization), for the CRAX2MACE model the area under the receiver operating characteristic curve was 0.612 and the Brier score was 0.061. The Hosmer-Lemeshow test estimated a non-optimal fit (χ 2 28, P < .001). Considering only hard events (cardiac death, acute myocardial infarction), the external validation of the CRAX2MACE model revealed a Brier score of 0.053 and an area under the receiver operating characteristic curve of 0.621. Hosmer-Lemeshow test was calculated by deciles and showed a poor fit (χ 2 31, P < .001)., Conclusion: CRAX2MACE model had a limited value for predicting 2-year major adverse cardiovascular events in an external validation cohort of patients with suspected CAD., (© 2021. American Society of Nuclear Cardiology.)

Background: To assess the incremental value of 18 F-fluorodeoxyglucose (FDG) cardiac positron emission tomography (PET) over dobutamine stress echocardiography (DSE) in predicting myocardial ischemia in patients with suspected coronary artery disease (CAD)., Methods: Forty-one patients with suspected CAD underwent within 7 days apart rest-stress cardiac PET with 82 Rb and DSE followed by cardiac 18 F-FDG PET imaging. 18 F-FDG images were scored on a 0 (no discernible uptake) to 2 (intense uptake) scale. Logistic regression analysis was performed to identify predictors of stress-induced ischemia. The incremental value of 18 F-FDG PET over DSE in detecting ischemia at 82 Rb PET cardiac imaging was assessed by the likelihood ratio chi-square and net reclassification index., Results: On 82 Rb-PET imaging, myocardial ischemia (ischemic total perfusion defect ≥ 5%) was detected in 20 (49%) patients. Inducible ischemia was found in 22 (54%) patients on DSE (biphasic or worsening response pattern in ≥ 1 segment) and in 21 (51%) patients on 18 F-FDG PET (uptake score of 2 in ≥ 1 segment). 18 F-FDG PET resulted as statistically significant predictor of ischemia on 82 Rb-PET. The addition of 18 F-FDG PET to DSE increased the likelihood of ischemia on 82 Rb-PET (P < .05). 18 F-FDG PET was able to reclassify the probability of stress-induced myocardial ischemia on both patient and vessel analyses., Conclusion: 18 F-FDG PET performed after dobutamine stress test may provide incremental value to DSE in the evaluation of myocardial ischemia. These results suggest that stress-induced myocardial ischemia can be imaged directly using 18 F-FDG PET after dobutamine stress test., (© 2021. American Society of Nuclear Cardiology.)

Background: We evaluated the prognostic value of changes in perfusion defect size (PDS) on serial MPS in patients treated with primary percutaneous coronary intervention (PCI) after acute myocardial infarction (AMI)., Methods: We enrolled 112 patients treated with primary PCI after AMI who underwent two stress MPS within 1 month and after 6 months. Improvement in PDS was defined as a reduction ≥5%. Remodeling was defined as an increase in left ventricular (LV) end-diastolic volume index ≥20%. Cardiac events included cardiac death, nonfatal MI, unstable angina, repeated revascularization, and heart failure., Results: During a median follow-up of 86 months, 22 events occurred. Event rate was higher (P &lt; .01) in patients with worsening of PDS compared to those with unchanged or improved PDS. Moreover, patients with remodeling had a higher (P &lt; .001) event rate compared to those without. At Cox analysis, worsening of PDS and remodeling resulted independent predictors of events (both P &lt; .01). Patients with both worsening of PDS and remodeling had the worst event-free survival (P &lt;.001)., Conclusion: In patients treated with primary PCI after AMI, worsening of PDS and remodeling are associated to higher risk of events at long-term follow-up. Gated stress MPS improves risk stratification in these patients., (© 2021. American Society of Nuclear Cardiology.)

Background: Chronotropic incompetence is common in patients with cardiovascular disease and is associated with increased risk of adverse events. We assessed the incremental prognostic value of heart rate reserve (HRR) over stress myocardial perfusion single-photon emission computed tomography (MPS) findings in patients with suspected coronary artery disease (CAD)., Methods: We studied 866 patients with suspected CAD undergoing exercise stress-MPS as part of their diagnostic program. The primary study endpoint was all-cause mortality. All patients were followed for at least 5 years. HRR was calculated as the difference between peak exercise and resting HR, divided by the difference of age-predicted maximal and resting HR and expressed as percentage., Results: During 7 years follow-up, 61 deaths occurred, with a 7% cumulative event rate. Patients experiencing death were older (P < .001), and had a higher prevalence of male gender (P < .001) and diabetes (P < .05). Patients with event also had lower values of HRR (65% ± 27% vs 73% ± 18%, P < .0001) and higher prevalence of stress-induced myocardial ischemia (25% vs 8%, P < .0001). Male gender, HRR and stress-induced ischemia were independent predictors of all-cause mortality (all P < .01). HRR improved the prognostic power of a model including clinical data and MPS findings, increasing the global χ 2 from 66 to 82 (P < .005)., Conclusions: Chronotropic incompetence has independent and incremental prognostic value in predicting all-cause mortality in patients with suspected CAD undergoing exercise stress-MPS. Hence, the evaluation of HRR may further improve patients' risk stratification., (© 2021. The Author(s).)

Purpose: We assessed the impact of COVID-19 infection on cardiovascular events in patients with suspected or known coronary artery disease (CAD) referred to stress single-photon emission computed tomography myocardial perfusion imaging (MPS)., Methods: A total of 960 consecutive patients with suspected or known CAD were submitted by referring physicians to stress MPS for assessment of myocardial ischemia between January 2018 and June 2019. All patients underwent stress-optional rest MPS. Perfusion defects were quantitated as % of LV myocardium and expressed as total perfusion defect (TPD), representing the defect extent and severity. A TPD ≥ 5% was considered abnormal., Results: During a mean follow-up of 27 months (range 4-38) 31 events occurred. Moreover, 55 (6%) patients had a COVID-19 infection. The median time from index MPS to COVID-19 infection was 16 months (range 6-24). At Cox multivariable analysis, abnormal MPS and COVID-19 infection resulted as independent predictors of events. There were no significant differences in annualized event rate in COVID-19 patients with or without abnormal MPS (p = 0.56). Differently, in patients without COVID-19, the presence of abnormal MPS was associated with higher event rate (p < .001). Patients with infection compared to those without had a higher event rate in the presence of both normal and abnormal TPD., Conclusion: In patients with suspected or known CAD, the presence of COVID-19 infection during a short-term follow-up was associated with a higher rate of cardiovascular events., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: We evaluated the performance of conventional (C) single-photon emission computed tomography (SPECT) and cadmium-zinc-telluride (CZT)-SPECT in a large cohort of patients with suspected or known coronary artery disease (CAD) and compared the diagnostic accuracy of the two systems using machine learning (ML) algorithms., Methods and Results: A total of 517 consecutive patients underwent stress myocardial perfusion imaging (MPI) by both C-SPECT and CZT-SPECT. In the overall population, an excellent correlation between stress MPI data and left ventricular (LV) functional parameters measured by C-SPECT and by CZT-SPECT was observed (all P < .001). ML analysis performed through the implementation of random forest (RF) and k-nearest neighbors (NN) algorithms proved that CZT-SPECT has greater accuracy than C-SPECT in detecting CAD. For both algorithms, the sensitivity of CZT-SPECT (96% for RF and 60% for k-NN) was greater than that of C-SPECT (88% for RF and 53% for k-NN)., Conclusions: MPI data and LV functional parameters obtained by CZT-SPECT are highly reproducible and provide good correlation with those obtained by C-SPECT. ML approach showed that the accuracy and sensitivity of CZT-SPECT is greater than C-SPECT in detecting CAD., (© 2020. American Society of Nuclear Cardiology.)

Background: We evaluated if risk scores commonly used to predict the absence of significant stenosis at coronary computed tomography (CT) angiography are useful to predict a normal stress myocardial perfusion imaging (MPI) study., Methods: Our cohort included a total of 1422 consecutive patients with zero coronary artery calcium score (ZCS) who underwent 82 Rb PET/CT for evaluation of suspected coronary artery disease (CAD). Predictive models were constructed as reported by Genders et al. and Alshahrani et al., and the probability of abnormal summed stress score (SSS) and of reduced myocardial perfusion reserve (MPR) based on these risk scores was assessed., Results: In the overall population, the prevalence of abnormal SSS was 0.10 and the prevalence of reduced MPR was 0.17 (both P < .001).The observed frequencies of abnormal SSS and reduced MPR vs the probabilities predicted by the Genders and Alshahrani models were above the diagonal identity line, highlighting an underestimation of the observed occurrence by these models. The areas under the receiver operating characteristic curve of the Genders and Alshahrani models indicated lack of discriminative ability for predicting abnormal SSS (0.547 and 0.527) and reduced MPR (0.509 and 0.538). The Hosmer-Lemeshow test revealed that both models underestimated the observed occurrence of abnormal SSS and reduced MPR., Conclusions: Available models were unable to identify among patients with ZCS those with a low probability of a normal stress MPI study. Thus, an optimal approach to rule out from MPI patients without detectable coronary calcium still needs to be improved., (© 2020. American Society of Nuclear Cardiology.)

Background: We performed a systematic review and meta-analysis to investigate the prognostic value of stress myocardial perfusion single-photon emission computed tomography (MPS) in predicting adverse cardiovascular events in patients with chronic kidney disease (CKD)., Methods: Studies published from inception until July 2020 were identified by PubMed and Embase databases search. Studies were included if they evaluated CKD patients referred for stress MPS, providing data on adjusted hazard ratio (HR) for the occurrence of adverse events. For studies providing only non-adjusted HR, the univariable risk estimate was included in the analysis. Pooled HR and 95% confidence interval (CI) were estimated using a random effects model to compare patients with abnormal and normal MPS. Whenever possible, incidence rate ratio (IRR) was also calculated and pooled., Results: Sixteen eligible studies were identified including 7834 patients with a follow-up range from 1 to 4.4 years. Eleven articles included patients with end-stage renal disease (IV-V CKD stage), 3 articles with III-V CKD stage and 2 articles with I-V CKD stage. The pooled HR for the occurrence of adverse events was 2.02 (95% CI 1.68-2.42) and heterogeneity was 34%. Among the included studies, 5 reported the HR for the occurrence of hard events, with a pooled HR of 2.36 (95% CI 1.77-3.13). A total of 8 studies reported data useful to calculate the IRR in patients with normal and abnormal perfusion. The pooled IRR was 2.37 (95% CI 1.63-3.47) and heterogeneity was 60%. At meta-regression analysis, we found an association between HR for adverse events and age, hypertension and smoking, while no significant association was found between HR for hard events and demographic and clinical variables., Conclusions: In patients with CKD an abnormal myocardial perfusion at stress MPS is associated with adverse cardiovascular events., (© 2021. American Society of Nuclear Cardiology.)

Background: Chronotropic response to pharmacological stress test is blunted in patients with autonomic neuropathy. The relationship between heart rate (HR) changes during pharmacological stress test and cardiac autonomic dysfunction has not been fully investigated. We assessed the potential interplay between HR response (HRR) and myocardial innervation in patients with suspected or known coronary artery disease (CAD)., Methods and Results: We studied 71 patients with suspected or known CAD referred to pharmacological stress myocardial perfusion imaging and 123 I metaiodobenzylguanidine ( 123 I-MIBG) cardiac scintigraphy. HRR was calculated as the maximum percent change from baseline according to the formula: (peak HR - rest HR)/rest HR × 100. 123 I-MIBG heart-to-mediastinum (H/M) ratio was calculated and a late H/M ratio < 1.6 was considered abnormal. HRR progressively decreased with decreasing late H/M ratio (P for trend = 0.02) and a significant correlation between HRR and late H/M ratio (P = 0.03) was observed. The addition of HRR to a model including age, diabetes, known CAD, left ventricular ejection fraction, and stress-induced ischemia added incremental value in predicting an abnormal late H/M ratio, increasing the global chi-square from 8.09 to 13.8 (P = 0.02)., Conclusions: The relationship between HRR and cardiac sympathetic innervation in patients with suspected or known CAD confirms a strong interplay between cardiac response to stress tests and cardiac autonomic activation. This finding suggests that HRR may be used as a surrogate for assessing cardiac sympathetic function., (© 2020. American Society of Nuclear Cardiology.)

Background: We measured myocardial blood flow (MBF) and perfusion reserve (MPR) by dynamic CZT-SPECT and 82 Rb-PET in patients with suspected or known coronary artery disease (CAD) and compared the accuracy of the two methods in predicting obstructive CAD., Methods: Twenty-five patients with available coronary angiography data underwent 99m Tc-sestamibi CZT-SPECT and 82 Rb-PET cardiac imaging. Stress and rest MBF and MPR were calculated by both methods and compared. Diagnostic accuracies of CZT-SPECT and PET were also assessed using a receiver-operator-characteristic curve., Results: CZT-SPECT yielded similar baseline MBF, but higher hyperemic MBF and MPR values compared to PET. There was a modest correlation between the two methods for MPR (r = 0.56, P < .01). MPR by CZT-SPECT showed a good ability in identify a reduced MPR by PET, with an area under the curve of 0.85. A MPR cut-off of 2.5 was identified by CZT-SPECT for detection of abnormal MPR by PET, with a sensitivity, specificity and accuracy of 86%, 73% and 80%. The area under the curve for the identification of obstructive CAD by regional MPR were 0.83 for CZT-SPECT and 0.84 for PET (P = .90). At CZT-SPECT, a regional MPR of 2.1 provided the best trade-off between sensitivity and specificity for identifying obstructive CAD. Diagnostic accuracy of CZT-SPECT and PET using respective cut-off values was comparable (P = .62)., Conclusion: Hyperemic MBF and MPR values obtained by CZT-SPECT are higher than those measured by 82 Rb-PET imaging, with a moderate correlation between the two methods. CZT-SPECT shows good diagnostic accuracy for the identification of obstructive CAD. These findings may encourage the use of this new technique to a better risk stratification and patient management., (© 2020. American Society of Nuclear Cardiology.)

Purpose: We performed a systematic review and a meta-analysis to investigate the successful ablation rate after radioiodine (RAI) administration in patients with differentiated thyroid cancer (DTC) at intermediate-high risk of recurrence., Methods: A comprehensive literature search of the PubMed, Scopus, and Web of Science databases was conducted according to the PRISMA statement., Results: The final analysis included 9 studies accounting for 3103 patients at intermediate-high risk of recurrence. In these patients, the successful ablation rates ranged from 51 to 94% with a 71% pooled successful ablation and were higher in intermediate (72%) than in high (52%)-risk patients. Despite the rigorous inclusion standards, a significant heterogeneity among the evaluated studies was observed. Higher administered RAI activities are associated with a lower successful ablation rate in the whole population and in the subgroup of high-risk patients. Furthermore, pooled recurrence rate in intermediate-risk patients achieving successful ablation was only 2% during the subsequent 6.4-year follow-up while the pooled recurrence rate was 14% in patients who did not achieve a successful ablation., Conclusion: In a large sample of 3103 patients at intermediate-high risk of persistent/recurrent disease, 71% of patients achieved a successful ablation. In these intermediate-risk patients, the probability of subsequent recurrence is low and most recurrence occurred in those with already abnormal findings at the first control., (© 2021. The Author(s).)

Traditional approach for predicting coronary artery disease (CAD) is based on demographic data, symptoms such as chest pain and dyspnea, and comorbidity related to cardiovascular diseases. Usually, these variables are analyzed by logistic regression to quantifying their relationship with the outcome; nevertheless, their predictive value is limited. In the present study, we aimed to investigate the value of different machine learning (ML) techniques for the evaluation of suspected CAD; having as gold standard, the presence of stress-induced ischemia by 82 Rb positron emission tomography/computed tomography (PET/CT) myocardial perfusion imaging (MPI) ML was chosen on their clinical use and on the fact that they are representative of different classes of algorithms, such as deterministic (Support vector machine and Naïve Bayes), adaptive (ADA and AdaBoost), and decision tree (Random Forest, rpart, and XGBoost). The study population included 2503 consecutive patients, who underwent MPI for suspected CAD. To testing ML performances, data were split randomly into two parts: training/test (80%) and validation (20%). For training/test, we applied a 5-fold cross-validation, repeated 2 times. With this subset, we performed the tuning of free parameters for each algorithm. For all metrics, the best performance in training/test was observed for AdaBoost. The Naïve Bayes ML resulted to be more efficient in validation approach. The logistic and rpart algorithms showed similar metric values for the training/test and validation approaches. These results are encouraging and indicate that the ML algorithms can improve the evaluation of pretest probability of stress-induced myocardial ischemia., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2021 Rosario Megna et al.)

We compared the prognostic value of myocardial perfusion imaging (MPI) by conventional- (C-) single-photon emission computed tomography (SPECT) and cadmium-zinc-telluride- (CZT-) SPECT in a cohort of patients with suspected or known coronary artery disease (CAD) using machine learning (ML) algorithms. A total of 453 consecutive patients underwent stress MPI by both C-SPECT and CZT-SPECT. The outcome was a composite end point of all-cause death, cardiac death, nonfatal myocardial infarction, or coronary revascularization procedures whichever occurred first. ML analysis performed through the implementation of random forest (RF) and k -nearest neighbors (KNN) algorithms proved that CZT-SPECT has greater accuracy than C-SPECT in detecting CAD. For both algorithms, the sensitivity of CZT-SPECT (96% for RF and 60% for KNN) was greater than that of C-SPECT (88% for RF and 53% for KNN). A preliminary univariate analysis was performed through Mann-Whitney tests separately on the features of each camera in order to understand which ones could distinguish patients who will experience an adverse event from those who will not. Then, a machine learning analysis was performed by using Matlab (v. 2019b). Tree, KNN, support vector machine (SVM), Naïve Bayes, and RF were implemented twice: first, the analysis was performed on the as-is dataset; then, since the dataset was imbalanced (patients experiencing an adverse event were lower than the others), the analysis was performed again after balancing the classes through the Synthetic Minority Oversampling Technique. According to KNN and SVM with and without balancing the classes, the accuracy ( p value = 0.02 and p value = 0.01) and recall ( p value = 0.001 and p value = 0.03) of the CZT-SPECT were greater than those obtained by C-SPECT in a statistically significant way. ML approach showed that although the prognostic value of stress MPI by C-SPECT and CZT-SPECT is comparable, CZT-SPECT seems to have higher accuracy and recall., Competing Interests: The authors declare that they have no conflict of interests., (Copyright © 2021 Valeria Cantoni et al.)

Background: The frequency of abnormal stress SPECT myocardial perfusion imaging (MPS) decreased over the past decades despite an increase in the prevalence of cardiovascular risk factors. These findings strengthen the need to develop more effective strategies for appropriately referring patients with suspected coronary artery disease (CAD) to cardiac imaging. The aim of this study was to develop pretest assessment models for predicting abnormal stress MPS., Methods: We included 5,601 consecutive patients with suspected CAD, who underwent stress MPS at our academic center. Two different models were considered: a basic model including age, gender, and anginal symptoms; and a clinical model including also diabetes, hypertension, hypercholesterolemia, smoking, and family history of CAD., Results: In patients with abnormal MPS, the basic model classified more than 75% of patients as intermediate risk, whereas only 23% were incorrectly classified as low risk. In patients with normal MPS, 45% were correctly classified as low risk and none as high risk. Basic and clinical models had a limited discriminating capacity (area under the receiver operating characteristic curve 0.644 for basic model and 0.647 for clinical model) between individuals with and without abnormal stress MPS. The decision curve analysis demonstrates a high net benefit across a range of threshold probabilities from ~ 15% to ~30% for both models., Conclusions: A pretest risk stratification based on traditional cardiovascular risk factors has a limited value for predicting an abnormal stress MPS in patients with suspected CAD. However, selecting a proper threshold probability enhances the appropriateness of referral to stress MPS., (© 2019. American Society of Nuclear Cardiology.)

The present review provides a description of recent advances in the field of functional imaging that takes advantage of the functional characteristics of thyroid neoplastic cells (such as radioiodine uptake and FDG uptake) and theragnostic approach of differentiated thyroid cancer (DTC). Physical and biological characteristics of available radiopharmaceuticals and their use with state-of-the-art technologies for diagnosis, treatment, and follow-up of DTC patients are depicted. Radioactive iodine is used mostly with a therapeutic intent, while PET/CT with 18 F-FDG emerges as a useful tool in the diagnostic management and complements the use of radioactive iodine. Beyond 18 F-FDG PET/CT, other tracers including 124 I, 18 F-TFB and 68 Ga-PSMA, and new methods such as PET/MR, might offer new opportunities in selecting patients with DTC for specific imaging modalities or treatments.

Purpose: The identification of coronary vascular dysfunction may enhance risk stratification in patients with resistant hypertension (RH). We evaluated if impaired coronary vascular function, assessed by rubidium-82 ( 82 Rb) positron emission tomography/computed tomography (PET/CT) imaging, is associated with increased cardiovascular risk in patients with hypertension without overt coronary artery disease (CAD)., Methods: We studied 517 hypertensive subjects, 26% with RH, without overt CAD, and with normal stress-rest myocardial perfusion imaging at 82 Rb PET/CT. The outcome end points were cardiac death, nonfatal myocardial infarction, coronary revascularization, and admission for heart failure., Results: Over a median of 38 months (interquartile range 26 to 50), 21 cardiac events (4.1% cumulative event rate) occurred. Patients with RH were older (p < 0.05) and had a higher prevalence of left ventricular hypertrophy (p < 0.001), a lower hyperemic myocardial blood flow (MBF), and myocardial perfusion reserve (MPR) (both p < 0.001) compared to those without. Conversely, coronary artery calcium content and baseline MBF were not different between patients with and without RH. At univariable Cox regression analysis, age, RH, left ventricular ejection fraction, coronary artery calcium score, and reduced MPR were significant predictors of events. At multivariable analysis, age, RH, and reduced MPR (all p < 0.05) were independent predictors of events. Patients with RH and reduced MPR had the highest risk of events and the major risk acceleration over time., Conclusion: The findings suggest that the assessment of coronary vascular function may enhance risk stratification in patients with hypertension., (© 2021. The Author(s).)

Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/qims-21-36). The authors have no conflicts of interest to declare.

The standard treatment of differentiated thyroid cancer (DTC) consists of surgery followed by iodine-131 ( 131 I) administration. Although the majority of DTC has a very good prognosis, more aggressive histologic subtypes convey a worse prognosis. Follow-up consists of periodically measurements of serum thyroglobulin, thyroglobulin antibodies and neck ultrasound and 123 I/ 131 I whole-body scan. However, undifferentiated thyroid tumors have a lower avidity for radioiodine and the ability of DTC to concentrate 131 I may be lost in metastatic disease. Positron emission tomography (PET)/computed tomography (CT) has been introduced in the evaluation of patients with thyroid tumors and the 2-[18F]-fluoro-2-deoxyd-glucose ( 18 F-FDG) has been largely validated as marker of cell's metabolism. According to the 2015 American Thyroid Association guidelines, 18 F-FDG PET/CT is recommended in the follow-up of high-risk patients with elevated serum thyroglobulin and negative 131 I imaging, in the assessment of metastatic patients, for lesion detection and risk stratification and in predicting the response to therapy. It should be considered that well-differentiated iodine avid lesions could not concentrate 18 F-FDG, and a reciprocal pattern of iodine and 18 F-FDG uptake has been observed. Beyond 18 F-FDG, other tracers are available for PET imaging of thyroid tumors, such as Iodine-124 ( 124 I), 18 F-tetrafluoroborate and Gallium-68 prostate-specific membrane antigen. Moreover, the recent introduction of PET/MRI, offers now several opportunities in the field of patients with DTC. This review summarizes the evidences on the role of PET/CT in management of patients with DTC, focusing on potential applications and on elucidating some still debating points., (Copyright © 2021 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.)

This study assessed the long-term predictive value of the response to therapy, evaluated by serum thyroglobulin (Tg) determination and neck ultrasound, and estimated the potential additional impact of diagnostic whole-body scan (WBS) in patients with differentiated thyroid cancer (DTC) treated with surgery and radioactive iodine (RAI) therapy. We retrospectively evaluated 606 DTC patients treated with surgery and RAI. Response to 131 I therapy at 12 months was assessed by serum Tg measurement, neck ultrasound, and diagnostic WBS. According to American Thyroid Association (ATA) guidelines, patients were classified as having a low, intermediate or high risk of recurrence and at 12 months as having an excellent response (ER) or no-ER. Follow-up was then performed every 6-12 months with serum Tg determination and imaging procedures. With a median follow-up of 105 months (range 10-384), 42 (7%) events requiring further treatments occurred. Twenty-five patients had additional RAI therapy, 11 with structural disease in the thyroid bed, eight in both thyroid bed and neck lymph nodes, four had lung metastases and two had bone metastases. The other 17 patients had additional surgery for nodal disease followed by RAI therapy. The ATA intermediate and high risk of recurrence, post-operative and pre-RAI therapy Tg ≥ 10 ng/mL, and the absence of ER at 12 months were independent predictors of events. Diagnostic WBS at 12 months permitted the identification of only five recurrences among the 219 ER patients according to serum Tg levels and ultrasound. In DTC patients, the response to therapy at 12 months after RAI therapy could rely on serum Tg measurement and neck ultrasound, while diagnostic WBS was not routinely indicated in patients considered in ER.

Background: We assessed the prognostic value of structural abnormalities and coronary vasodilator function in diabetic patients referred to a PET/CT for suspected coronary artery disease (CAD)., Methods: We studied 451 diabetics and 451 nondiabetics without overt CAD and normal myocardial perfusion. Myocardial blood flow (MBF) was computed from the dynamic rest and stress imaging. Myocardial flow reserve (MFR) was defined as ratio of hyperemic to baseline MBF and was considered reduced when < 2., Results: During a mean follow-up of 44 months 33 events occurred. Annualized event rate (AER) was higher in diabetic than nondiabetic patients (1.4% vs 0.3%, P < .001). Diabetic patients with reduced MFR had higher AER compared to those with preserved MFR (3.3% vs 0.4%, P  < .001). At Cox analysis, age, BMI and reduced MFR were independent predictors of events in diabetic patients. Patients with diabetes and reduced MFR had lower event-free survival compared to nondiabetic patients and MFR < 2 (P < .001). Event-free survival was similar in patients with diabetes and normal MFR and those without diabetes and reduced MFR., Conclusions: Diabetic patients with reduced MFR had higher AER and lower event-free survival compared to those with preserved MFR and to nondiabetic patients., (© 2021. The Author(s).)

Background: We performed a meta-meta-analysis to evaluate the prognostic value of coronary flow reserve (CFR) assessed by cardiac positron emission tomography (PET) imaging in patients with suspected or known coronary artery disease (CAD)., Methods: Studies published until April 2019 were identified by database search. We included studies if they evaluated CFR by PET providing data on adjusted hazard ratio (HR) for the occurrence of adverse events. Annualized event rates were calculated and the incidence rate ratios with 95% confidence interval (CI) were estimated to compare patients with impaired and preserved CFR., Results: We identified 13 eligible articles including 11,867 patients with a follow-up ranging from 0.6 to 7.1 years. The HR for the occurrence of major adverse cardiac events (MACE) was reported in 11 studies and pooled HR was 1.93 (95% CI 1.65-2.27). The HR for the occurrence of hard events was reported in 5 studies and pooled HR was 3.11 (95% CI 1.88-5.14). Six studies reported data useful to calculate separately the incidence rate of MACE in patients with preserved and impaired CFR and pooled IRR was 2.26 (CI 95% 1.79-2.85). Three studies reported data useful to calculate separately the incidence rate of hard events in patients with preserved and impaired CFR and pooled IRR was 4.12 (CI 95% 3.08-5.51). At meta-regression analysis, we found an association between HR for MACE and gender, diabetes and hypertension, while no significant association was found between HR for hard events and demographic and clinical variables., Conclusion: In patients with suspected or known CAD, an impaired CFR is associated with adverse cardiovascular events. However, the large heterogeneity in study population underlines the need for further investigations to maximize the prognostic role of CFR.

Background: Breast attenuation may impact the diagnostic accuracy of stress myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT). We compared the performance of conventional (C)-SPECT and cadmium-zinc-telluride (CZT)-SPECT systems in women with low-intermediate likelihood of coronary artery disease (CAD)., Methods and Results: A total of 109 consecutive women underwent stress-optional rest MPI by both C-SPECT and CZT-SPECT. In the overall study population, a weak albeit significant correlation between total perfusion defect (TPD) measured by C-SPECT and CZT-SPECT was observed (r = 0.38, P < .001) and at Bland-Altman analysis the mean difference in TPD (C-SPECT minus CZT-SPECT) was 2.40% (P < .001). Overall concordance of semi-quantitative diagnostic performance between C-SPECT and CZT-SPECT was observed in 52 (48%) women with a κ value of 0.09. Normalcy rate was significantly higher using CZT-SPECT compared to C-SPECT (P < .001). Machine learning analysis performed through the implementation of J48 algorithm proved that CZT-SPECT has higher sensitivity, specificity, and accuracy than C-SPECT., Conclusions: In women with low-intermediate likelihood of CAD, there is a poor concordance of diagnostic performance between C-SPECT and CZT-SPECT, and CZT-SPECT allows better normalcy rate detection compared to C-SPECT.

Aim: To assess the value of bone scintigraphy and 18 F-fluorocholine PET/computed tomography (CT) in predicting outcome in patients with prostate cancer and bone metastases treated with 223 radium., Materials & Methods: Retrospective analysis of 48 patients that underwent 223 radium therapy. End points were pain relief and overall survival., Results: After therapy, pain relief was observed in 27 patients. Patients without pain relief had more bone lesions at PET/CT than at bone scintigraphy (pretherapy imaging mismatch). In 39 patients who completed treatment protocol, post-therapy alkaline phosphatase and pretherapy imaging mismatch were independent predictors of poor overall survival., Conclusion: Patients with more lesions at 18 F-fluorocholine PET/CT than at bone scintigraphy had a poor prognosis. The combined imaging approach could be useful to predict outcome after 223 radium therapy., Competing Interests: Financial & competing interests disclosure The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. No writing assistance was utilized in the production of this manuscript., (© 2021 Alberto Cuocolo.)

Background: We performed a meta-analysis to compare the diagnostic performance of conventional SPECT (C-SPECT) and cadmium-zinc-telluride (CZT)-SPECT systems in detecting angiographically proven coronary artery disease (CAD)., Methods: Studies published between January 2000 and February 2018 were identified by database search. We included studies assessing C-SPECT or CZT-SPECT as a diagnostic test to evaluate patients for the presence of CAD, defined as at least 50% diameter stenosis on invasive coronary angiography. A study was eligible regardless of whether patients were referred for suspected or known CAD., Results: We identified 40 eligible articles (25 C-SPECT and 15 CZT-SPECT studies) including 7334 patients (4997 in C-SPECT and 2337 in CZT-SPECT studies). The pooled sensitivity and specificity were 85% and 66% for C-SPECT and 89% and 69% for CZT-SPECT imaging studies. The area under the curve was slightly higher for CZT-SPECT (0.89) compared to C-SPECT (0.83); accordingly, the summary diagnostic OR was 17 for CZT-SPECT and 11 for C-SPECT. The accuracy of the two tests slightly differs between C-SPECT and CZT-SPECT (chi-square 11.28, P < .05). At meta-regression analysis, no significant association between both sensitivity and specificity and demographical and clinical variables considered was found for C-SPECT and CZT-SPECT studies., Conclusions: C-SPECT and CZT-SPECT have good diagnostic performance in detecting angiographic proven CAD, with a slightly higher accuracy for CZT-SPECT. This result supports the use of the novel gamma cameras in clinical routine practices also considering the improvements in acquisition time and radiation exposure reduction.

Purpose: In pediatric patients with differentiated thyroid cancer (DTC), the risk of recurrence is high and the indication for postoperative 131 I administration is still debated. The aim of this study was to assess the outcome in low and intermediate risk pediatric DTC patients., Methods: We retrospectively evaluated 45 pediatric patients with low or intermediate risk DTC, treated with surgery and 131 I between 1992 and 2002 and with no detectable antithyroglobulin (Tg) antibodies. Follow-up was performed every 6-12 months with Tg blood level determination and imaging procedures., Results: During follow-up (64 ± 53 months), 15 events occurred (33% cumulative event rate, with an annual event rate of 5% person years). Five of these patients were submitted to additional surgery and all these 15 patients underwent a second 131 I treatment course. All patients were alive at the end of the follow-up. Structural persistent disease occurred more frequently in patients at intermediate risk (p < 0.01) and in those with Tg values after thyroid hormone withdrawal >10 ng/ml before 131 I therapy (p < 0.01). At multivariate analysis, only a postoperative thyroid stimulating hormone-stimulated Tg level >10 ng/ml was an independent predictor of persistent disease., Conclusions: In pediatric patients with DTC, postoperative high stimulated Tg values (>10 ng/ml) should be taken into account for deciding the extent of both initial treatment and follow-up.

Purpose: We assessed the effects of the COVID-19 pandemic on myocardial perfusion imaging (MPI) for ischemic heart disease during the lockdown imposed by the Italian Government., Methods: We retrospectively reviewed the number and the findings of stress single-photon emission computed tomography (SPECT)-MPI performed between February and May 2020 during the COVID-19 pandemic at the University of Napoli Federico II. The number and the findings of stress SPECT-MPI studies acquired in the corresponding months of the years 2017, 2018, and 2019 were also evaluated for direct comparison., Results: The number of stress SPECT-MPI studies performed during the COVID-19 pandemic (n = 123) was significantly lower (P < 0.0001) compared with the mean yearly number of procedures performed in the corresponding months of the years 2017, 2018, and 2019 (n = 413). Yet, the percentage of abnormal stress SPECT-MPI studies was similar (P = 0.65) during the pandemic (36%) compared with the mean percentage value of the corresponding period of the years 2017, 2018, and 2019 (34%)., Conclusion: The number of stress SPECT-MPI studies was significantly reduced during the COVID-19 pandemic compared with the corresponding months of the previous 3 years. The lack of difference in the prevalence of abnormal SPECT-MPI studies between the two study periods strongly suggests that many patients with potentially abnormal imaging test have been missed during the pandemic.

Background: The frequency of abnormal stress single-photon emission computed tomography myocardial perfusion imaging (MPS) has decreased over the past decades despite an increase in the prevalence of cardiovascular risk factors. This study evaluated the temporal trend of abnormal stress MPS and its relationship with risk factors in a cohort of Italian subjects., Methods: We included all patients who underwent clinically indicated stress MPS at our academic center between January 2006 and December 2017. Patients were assessed for change in demographics, clinical symptoms, risk factors, and frequency of abnormal and ischemic MPS., Results: A total of 8,886 stress MPS studies were performed (3,350 abnormal). Age, male gender, diabetes, smoking, and angina were independent predictors of abnormal MPS. There was a slight decline in the frequency of abnormal (from 39 to 36%, P < 0.05) and ischemic (from 25 to 22%, P < 0.01) MPS during the study period, while the percentage of patients with hypertension, hypercholesterolemia, smoking, and angina increased. The Cochran-Mantel-Haenszel test indicates that the likelihood of having an abnormal MPS did not change over time for age, diabetes, smoking, and a history of coronary artery disease (CAD), increased for hypertension and hypercholesterolemia and decreased for male compared to female gender., Conclusions: In our cohort of Italian subjects, there was a slight temporal decline in the frequency of abnormal and ischemic MPS despite an increase over time in the prevalence of many cardiac risk factors. These results strengthen the need to develop more effective strategies for appropriately referring patients to cardiac imaging procedures.

Aims: 18 F-FDG PET/CT is the most accurate imaging modality in differentiated thyroid cancer (DTC) patients with either an aggressive histology, an absence of radioiodine uptake in neoplastic foci, or in the absence of imaging abnormalities in patients with an elevated serum thyroglobulin (Tg) level that progresses with time. We evaluated the diagnostic performance of FDG PET/MR in comparison with that of PET/CT., Methods and Results: Following the injection of a single 18 F-FDG activity, PET/MR and PET/CT were sequentially performed in 40 consecutive patients with DTC previously treated with total thyroidectomy and radioiodine ablation. All patients were then followed up for at least 6 months. PET/MR was positive in 11 patients and PET/CT in 10. PET/MR detected 33 tumor foci and PET/CT 30. During the follow-up of the 12 patients with negative initial PET studies and with a detectable serum Tg, only one patient had a neck recurrence and the administration of an empiric high activity of 131 I in the other 11 patients did not reveal any tumor focus. In the 17 patients with an initial serum Tg level < 2 ng/mL, no recurrence occurred., Conclusion: This study confirms the high diagnostic accuracy of FDG PET studies in DTC patients with elevated serum Tg levels and shows that PET/MR brings similar information as compared to PET/CT imaging.

Diabetes represents a worldwide increasing problem and cardiovascular disease is the most common cause of death in diabetic patients. Pathophysiology that links diabetes to cardiovascular disease is a complex and multifactorial phenomenon evolving over time and involving both large blood vessels (macrovasculature) and small blood vessels (microvasculature). Myocardial perfusion imaging (MPI) imaging by both single-photon emission computer tomography and positron emission tomography with different specific tracers has become an indispensable tool for discriminating normal from diseased myocardial tissues and left ventricular function and monitoring myocardial blood flows, leading to the evaluation of almost overall physiologic consequences of the macro- and microvascular impairment involved in diabetic patients. This review will provide an overview of the role of MPI in the diagnosis and risk assessment of patients with diabetes and suspected or known CAD.