bluuebunny/crossref_metadata_2025_split huggingface dataset:
CZT SPECT regional myocardial flow reserve: can it enhance risk stratification?
Authors: Mesquita C , Palazzo I , Pacheco J , Ker W , Sabra M M M , Correa N L , Chambi A 
Published: June 2024

Abstract

Background
Numerous studies indicate that patients with diminished capacity for maximal hyperemia face an unfavorable cardiovascular prognosis. The presence of compromised coronary flow reserve is linked to a higher incidence of adverse cardiovascular outcomes (1). SPECT equipment featuring high-performance CZT detectors has been utilized for the quantitative evaluation of coronary flow at rest and during maximal hyperemia. Incorporating Myocardial Flow Reserve (MFR) into SPECT MPI for CAD screening using CZT SPECT may aid in identifying high-risk patients. In one study utilizing CZT SPECT, all regions with a regional CZT MFR ≤ 1.8 exhibited an invasive CFR &lt; 2 (2). The clinical utility of regional CZT-derived MFR data is still under evaluation but could assist in risk stratification.

Objective
To describe the frequency of abnormal MFR in patients referred for CZT SPECT and determine if regional MFR data could contribute to risk stratification in this context.
Methodology: One hundred consecutive patients with suspected CAD or known CAD were referred for CZT SPECT between October 7th, 2021, and December 30th, 2022. Patients underwent pharmacological stress myocardial perfusion scintigraphy and rest imaging using a D-SPECT device (Spectrum Dynamics) with dynamic tomographic image acquisition (dynamic SPECT) following administration of 99mTc-sestamibi via an injection pump (Bracco) at a flow rate of 1 ml/second. The dynamic tomographic images were analyzed using Cedars Sinai's QPS kinetic ® software to calculate MFR. MFR values &lt; 2, either regional or global, were considered abnormal. Statistical analysis employed a significance level of 5% and included the Chi-square and Fisher exact test.

Results
We evaluated 100 patients (15 men) with a mean age of 71.4 years. Of these 100 exams: 13 exhibited MFR &lt; 2.0 (Group A); 51 had MFR between 2.0 and 3.0 (Group B); and 36 had MFR &gt; 3.0 (Group C). In Group B, 14 patients displayed MFR in any of the 3 coronary territories below 2.0 (27%). Group C had no patients with reduced regional MFR. Myocardial ischemia was more prevalent in patients in Group A compared to Group B (54% vs. 19%; p = 0.01) and in Group B compared to Group C (19% vs. 3%; p = 0.02). Patients with regional MFR &lt; 2.0 in Group B exhibited a higher incidence of myocardial ischemia compared to patients in Group B with normal regional MFR (35% vs. 10%; p = 0.02).

Conclusion
A decreased regional MFR as measured by CZT SPECT is observed in one out of four patients with MFR between 2.0 and 3.0; and is associated with an increased prevalence of myocardial ischemia. These findings suggest a potential additional benefit in risk stratification that may be derived from regional quantitative blood flow assessment with CZT SPECT.
Regional left ventricle involvement in cardiac transthyretin amyloidosis in SPECT/CT with [99mTc]Tc-DPD
Authors: Holcman K , Rubis P , Stepien A , Graczyk K , Mroz K , Szot W , Dziewicka E , Podolec P , Kostkiewicz M 
Published: June 2024

Abstract

Background
Transthyretin amyloid (ATTR) cardiomyopathy is now more frequently diagnosed, partly due to advances in scintigraphic imaging and introduction of non-invasive diagnostic algorithms. Application of hybrid technique single-photon emission computed tomography and computed tomography (SPECT/CT) provides greater anatomic resolution, enabling the assessment of regional cardiac involvement.

Purpose
The aim of this prospective study was assessment of left ventricle involvement in patients with ATTR in SPECT/CT with [99mTc]Tc 3,3-disphono-1,2-propanodicarboxylic acid (DPD).

Methods
We present data based on evaluation of 100 patients, index patients with ATTR (group 1) and first-degree relatives (group 2) who were studied between June 2020 and December 2023. Study protocol included clinical data, free light chain blood immunoglobulins and urine immunofixation, transthoracic echocardiography (TTE) with global longitudinal strain (GLS) analysis, planar whole body acquisition and SPECT/CT with [99mTc]Tc-DPD, genetic testing by an amplicon-based next-generation TTR sequencing approach, and in selected cases cardiac or soft tissue biopsy.

Results
Study was conducted as multimodality and genetic cascade screening for relatives of individuals with ATTR. The population included hereditary ATTR (ATTRm) and ATTR wild type (ATTRwt). There were detected following types of TTR variants - Phe53Leu, Ala101Val, Glu112Lys, Glu109Lys, Glu122Lys, Glu82Lys. Overall, none of ATTRwt relatives expressed increased tracer uptake in scintigraphy. Overall, 26% first-degree relatives were diagnosed with pathogenic TTR variant and 7% had positive SPECT/CT with [99mTc]Tc-DPD. Importantly, among patients with positive SPECT/CT with [99mTc]Tc-DPD 58% presented asymmetrical left ventricle uptake. Overall, there were no differences in terms of radiotracer distribution between ATTRwt and ATTRm groups (p=0.85).

Conclusions
Regional left ventricle involvement in cardiac transthyretin amyloidosis can be assessed in SPECT/CT with [99mTc]Tc-DPD. The majority of patients present asymmetric cardiac uptake of radiotracer, both in the ATTRm and ATTRwt groups. Assessment of regional left ventricle involvement in cardiac transthyretin amyloidosis in SPECT/CT may in future translate into further enhancement of disease evaluation and improving prognosis in the group of patients.
Myocardial flow reserve recovery in patients with Takotsubo syndrome: insights from positron emission tomography
Authors: Kadoya Y , Chong A , Small G , Chow B , Dekemp R , Ruddy T , Beanlands R , Crean A 
Published: June 2024

Abstract

Background
Coronary microvascular dysfunction (CMD) has been implicated in the pathogenesis of Takotsubo syndrome (TTS). Positron emission tomography (PET) plays a key role in the assessment of CMD through myocardial flow reserve (MFR). However, there is limited information on the temporal progression of MFR and its relationship to coronary artery disease (CAD) in TTS patients.

Methods
This study evaluated patients with TTS who underwent cardiac catheterization and PET within one year of hospitalization. Patients were categorized into acute (≤10 days), subacute (11-30 days), and chronic (≥31 days) stages based on post-onset time of PET assessment. MFR comparisons between stages, prevalence of abnormal MFR (&lt;2.0), and MFR changes with or without obstructive CAD (≥70% stenosis as per coronary angiography) were analyzed.

Results
Of the 88 patients studied (mean age 70; 96% female), 52 (59%) were in the acute, 17 (19%) in the subacute, and 19 (22%) in the chronic stage. Median MFR in the acute stage was 2.0 (1.5-2.3), with 58% of patients showing abnormal MFR. A significant time-dependent improvement in MFR was observed (p=0.002) (Figure A), accompanied by a decreased prevalence of abnormal MFR. Patients with obstructive CAD in the acute stage had a significantly lower MFR compared to patients without CAD (1.81 vs. 2.15, p=0.027), while no MFR improvement was observed in the subacute and chronic stages (p=0.346) (Figure B).

Conclusions
PET-derived MFR was impaired in TTS patients during the acute phase, with improvement suggesting potential recovery from CMD over time. The concurrent presence of obstructive CAD might impede this recovery process. Figure B
Prognostic value of motion corrected cardiac PET images with normal interpretation
Authors: Oldfield C , Armstrong I , Arumugam P 
Published: June 2024

Abstract

Background
Patient motion during rest-stress vasodilator rubidium-82 myocardial perfusion PET remains a challenge and can affect relative images interpretation when severe. Current commercial solutions are limited to frame-by-frame correction of dynamic images for blood flow assessment. The correction of time-averaged static images remains a challenge. Our department has previously published work on the severity and prevalence of motion degradation of static relative perfusion images and demonstrated the usefulness of a prototype Data-Driven Motion Correction (DDMC) algorithm. We are evaluating this software in patients with evidence of motion on dynamic images and there is artefact suggestive of motion affecting relative perfusion images.

Purpose
The purpose of this work was to look at clinical follow up (hospital admission due to chest pain, MI or all cause death) of cases where DDMC static images were interpreted as normal.

Method
We retrospectively identified all patient between April 2018 and December 2020 that were referred for clinically indicated myocardial perfusion using rubidium-82. All patients’ images were acquired on a Siemens Biograph Vision 600 following administration of 20 mCi of Rb-82. A three-year follow-up of MACE and admission records for all patients.

Results
We identified 128 patients (54F: 57.5±9.3yr; 74M: 62.1±9.0yr) where DDMC was used to correct for significant motion blurring of the static relative perfusion images. Of these, 87 patients (46F,41M) were reported as normal. Follow-up showed no MACE, admission or all-cause death in all female patients. In the male patients, two were admitted for troponin-negative chest pain and there were five deaths, but none were cardiac-related.

Conclusion
This work demonstrates the usefulness of the DDMC for static motion correction in salvaging and improving image quality while continuing to provide reliable prognostic information for images interpreted as normal.
Automated quantitation of 18F-flurpiridaz PET MPI and its diagnostic performance of coronary artery disease
Authors: Builoff V , Lemley M , Fujito H , Miller R J H , Ramirez G , Kavanagh P , Buckley C , Berman D , Slomka P 
Published: June 2024

Abstract

Background/Introduction
18F-flurpiridaz, a novel positron emission tomography (PET) myocardial perfusion (MPI) imaging tracer, has shown efficacy in the detection of obstructive coronary artery disease (CAD) and is anticipated to be adopted in clinical practice soon. This post-hoc analysis of the 18F-flurpiridaz phase III clinical trial (NCT01347710) investigates the diagnostic performance of fully automated quantitative analysis by QPET software (Cedars-Sinai, Los Angeles, California, United States) for stress total perfusion deficit (S_TPD) and ischemic total perfusion deficit (I_TPD), compared to expert reader assessments in the detection of obstructive coronary artery disease (CAD) defined as stenosis ≥70%.

Purpose
The current standard method for interpreting PET MPI images involves visual assessment by a physician, which is inherently subjective and prone to high inter-reader variability. Quantification improves reproducibility of PET MPI evaluation.

Methods
This study retrospectively analyzes 753 cases from the original trial data, calculating area under the receiver operating characteristic curve (AUC) for S_TPD and I_TPD, and compares these values with summed stress scores (SSS) and summed difference scores (SDS) provided by three expert readers (R1, R2, R3), accounting for repeated readings as in the original trial, to evaluate diagnostic accuracy. Normal databases for this analysis were developed using 15 patients from the Phase II trial. Contours were verified by an experienced technologist. All other processing was fully automated.

Results
The contours were corrected in 2.4% stress and 4.4% rest cases. The AUC values for the readers’ SSS for stenosis ≥70% were found to be 0.812 (95% confidence interval [CI] 0.778 – 0.846) for R1, 0.801 (95% CI 0.766 – 0.836) for R2, and 0.828 (95% CI 0.795 – 0.860) for R3, compared to 0.812 (95% CI 0.778 – 0.846) for automatically quantified S_TPD (Figure 1A). The AUC values for the readers’ SDS for stenosis ≥70% were found to be 0.789 (95% CI 0.753 – 0.826) for R1, 0.780 (95% CI 0.744 – 0.816) for R2, and 0.798 (95% CI 0.761 – 0.834) for R3, compared to 0.813 (95% CI 0.778 – 0.848) for I_TPD (Figure 1B). Sensitivity of automated S_TPD quantification was 87% (95% CI 81% - 91%) and specificity was 57% (95% CI 52% - 61%) (Figure 2A). Sensitivity of I_TPD quantification was 83% (95% CI 77% - 87%) and specificity was 62% (95% CI 58% - 66%) (Figure 2B). Almost all quantitative results were similar to the readers’ results (p = NS), except for the comparison of AUC for I_TPD to SDS for R2, where I_TPD was higher (p = 0.04) (Figure 1B).

Conclusion
Quantitative analysis is comparable to expert reader evaluations in detecting ≥70% stenosis in CAD but can be derived consistently and automatically. The incorporation of TPD quantitative measures could standardize and potentially enhance the diagnostic process for obstructive CAD.
The diagnostic value of 18F-FDG PET/CT in suspected native valve endocarditis - a terciary center experience
Authors: Costa G , Batista G , Monteiro E , Guimaraes J , Fernandes D , Goncalves L , Vieira M J 
Published: June 2024

Abstract

Background
Infective endocarditis (IE) is difficult to diagnose accurately, especially for native valve endocarditis (NVE) and prosthetic material-related infection (PVE). The aim of this study is to evaluate the diagnostic performance of 18F-FDG PET in patients with suspected IE referred for PET/CT imaging.

Purpose
This retrospective study aims to assess the diagnostic value of 18F-FDG PET/CT for suspected NVE.

Methods
Data were collected from all patients who underwent 18F-FDG PET/CT for suspected IE at a tertiary center between May 2016 and January 2022. The final diagnosis of IE was established by consulting the Endocarditis team's diagnosis at the time of hospital discharge or death, after considering clinical, microbiological, and imaging information as well as clinical response. Sensitivity, specificity, and positive and negative predictive values of 18F-FDG PET/CT in diagnosing NVE were estimated.

Results
The study included 87 patients, of whom 32 had suspected NVE. The mean age was 62 +/- 19 years, and 62% were male. Of the patients with suspected NVE, 56% were male, with a median age of 53.5 (IQR 41.5-71) years. Fever was present in 84% of patients, and 16% had signs of heart failure. Laboratory tests showed a mean CRP of 16.2 mg/dL and a mean leucocyte count of 10.9 G/L. Among the suspected NVE patients, 8 had a definitive diagnosis of IE, with compatible findings observed in 18F-FDG PET/CT for 5 patients. The calculated sensitivity and specificity of 18F-FDG PET/CT for diagnosing NVE were 62.5% and 100%, respectively.

Conclusion
18F-FDG PET/CT appears to be highly specific but not very sensitive for diagnosing NVE.
[82Rb] biodistribution and radiation dosimetry in a pediatric population
Authors: Kamani C H , Gnesin S , Di Bernardo S , Dietz M , Allenbach G , Dolan M , Sekarski N , Prior J 
Published: June 2024

Abstract

Introduction
There is no established recommendation on the use of [82Rb] PET/CT in the paediatric population and a lack of [82Rb] dosimetry data in this population. We aimed to estimate paediatric dosimetry based on adult biokinetic data and prospectively acquired paediatric biokinetic data.

Materials and methods
Organ absorbed doses (OAD) and effective doses (E) were estimated using ICRP-103 based OLINDA/EXM 2.1 software. We calculated paediatric OAD and E from image-derived biokinetic data (OADp,Ab and Ep,Ab respectively) according to age groups. [82Rb] EANM paediatric dosage card cluster and the recommended administered activity were then determined. Ten paediatric participants (M:F 7:3; mean age 8.8±6.6) underwent dynamic rest and stress 3D-SiPM [82Rb] PET/CT scans. Using PMOD software, source organs volumes were delineated to obtain source organ time activity curves and participant specific organ masses based on PET/CT data to derive subject-specific OAD (OADp and Ep respectively) data.

Results
[82Rb] was assigned to the EANM PDC B-Cluster. Estimated ranges for Ep,Ab resp. Ep were 2.19E-02; 1.15E-03, resp. 9.62E-03; 1.04E-03 mSv/MBq. Ep,Ab after a single [82Rb] infusion was between 0.5–0.7 mSv, similar to Ep from for 3D PMT (0.4–0.8 mSv), while Ep was reduced by 0.2–0.4 mSv for 3D SiPM PET/CT. The most irradiated organs were the kidneys and the heart wall in infant and new-born group, followed by heart wall in the other age groups, hence, the small intestine, pancreas, lungs, adrenals, and rest of the gastrointestinal tract. [82Rb] PET/CT was safe and well-tolerated by all participants.

Conclusion
We firstly provide original dosimetry data for the use of [82Rb] PET/CT in the paediatric population, showing reasonably low radiation exposure, and confirming safety and tolerability of [82Rb] PET/CT in this population. Based on our estimations, we provided recommendations for the insertion of [82Rb] in the EANM Paediatric Dosage Card.
Evaluation of myocardium metabolism by PET-CT on hypertrophic cardiomyopathy
Authors: Alves P , Fernandes C R , Silva R , Gomes A , Abrunhosa A , Castelo-Branco M , Goncalves L , Ferreira M J 
Published: June 2024

Abstract

Background
Hypertrophic cardiomyopathy is defined as the presence of increased left ventricle (LV) myocardial wall thickness (MWT) not solely explained by loading conditions. Myocardial metabolism can be assessed by PET-CT with 2-[18F]FDG. The purpose of this study was to assess myocardial LV wall metabolism and features related with non-obstructive HCM with normal LV ejection fraction, namely, MWT, left atrium volume (LAV) and biochemical markers of LV dysfunction (NT-proBNP) and the score of sudden cardiac death (SCD)

Methods and Results
Thirty patients were recruited with an age of 54.4±11.3, 60% males and with a MWT of 20.3±4.3 and an LAV of 46.1±16.5 and a NT-proBNP of 661.2±724.2. PET-CT was performed in a Biograph Vision 600, Siemens and to suppress physiologic 2-[18F]FDG cardiac uptake, a 2 day high-fat/low-carbohydrate diet and a 12 hours overnight fast were prescribed. Increased 2-[18F]FDG myocardial uptake (increased metabolism) was considered when above the vascular activity (threshold ≥ 1) and presented as a percentage of LV myocardium. Areas of increased metabolism were seen in 60% of the patients with an extension of 19.1± 24.0. MWT, LAV and NT-proBNP were significantly correlated with 2-[18F]FDG uptake with a correlation coefficient of 0.39 (p=0.03) 0.43 (p=0.02), 0.51(p=0.01), respectively.

Conclusions
Increased metabolism in the wall of the LV seems to have a role on phenotype expression of the disease and on myocardial dysfunction
Is there a link between cancer and atherosclerotic cardiovascular disease?
Authors: Fernandes R , Borges-Rosa J , Silva R , Costa G , Goncalves L , Ferreira M J 
Published: June 2024

Abstract

Background
Atherosclerotic cardiovascular disease (ACVD) is a major cause of morbidity and mortality around the world. Women bellow 50 years are almost, invariably, of low risk. There is an overlap of biological mechanisms between ASCVD and cancer.

Purpose
The main purpose of this study was to evaluate inflammatory activity in the aorta of young women with breast cancer before treatment and relate it with total metabolic tumor volume (MTV) and age.

Methods
This was a retrospective study that included consecutive women under 55 years without diabetes or other significant cardiovascular risk factors for ACVD that underwent 2-[18F]FDG PET-CT for breast cancer staging before treatment. To assess the metabolic activity in the aorta the maximum lesion tissue-to-background ratio (TBR) was recorded for each segment.

Results
44 patients were included, with a mean age of 42.9 ± 7.45 years and a total median MTV of 5.67 ± 45.1 cm3. Spearman correlation was used, and the results are displayed in table 1.

Conclusion
Metabolic/inflammatory activity in the abdominal aorta wall was related with tumor metabolic activity but not with age. In this young group of breast cancer women, the metabolic/inflammatory activity of both conditions seemed to be linked.
Macrophage depletion delays infiltration of inflammatory macrophages into the infarct area after myocardial infarction in mice
Authors: Hess A , Strunk M , Willmann M , Ross T L , Bengel F M , Thackeray J T 
Published: June 2024

Abstract

Background/Introduction
Myeloid-derived inflammatory macrophages expressing CCR2 are crucial for scar formation and repair after myocardial infarction (MI). Interference with macrophage dynamics impairs healing and promotes intraventricular thrombus formation, but the precise dynamics of CCR2 macrophages in the left ventricle (LV) under these conditions remain unclear.

Purpose
We investigated the impact of macrophage depletion on infarct CCR2 expression, microcalcification, and cardiac functional outcome in mice after reperfused MI.

Methods
Male and female C57BL/6N mice underwent 60 min ischemia/reperfusion MI (n=24) or sham (n=8) 24h after injection of clodronate-liposomes (n=8m, 8f) for macrophage depletion, or PBS-liposomes (n=8m, 8f). Infarct CCR2 expression was measured on MI+4d by 68Ga-ECL1i PET. Microcalcification was assessed by 18F-NaF PET/CT at 4wks. MRI and 99mTc-tetrofosmin SPECT calculated LV function and infarct sizes at 6wks.

Results
Acute mortality was markedly higher after macrophage depletion within 7d of MI compared to PBS (%, 37.5 vs 0). Infarct CCR2 expression was significantly increased in macrophage depletion MI vs sham on d4 (%injected dose (ID)/g; 0.39±0.13 vs 0.25±0.05; p=0.005), but similar between PBS MI and sham (ID/g; 0.31±0.06, p=0.1), indicating rapid repopulation of peripheral monocytes after single time macrophage depletion, and delayed infiltration into injured myocardium. There were no sex dependent differences in infarct CCR2 expression. Infarct size after MI was 25.9±9.3 %LV with no difference between treatments. LV ejection fraction at 6wks was significantly reduced after MI vs sham, but comparable between treatments (%; clodronate: 33±9 vs PBS: 37±8 vs sham 66±5, p&lt;0.001). Heart weight at 6wks was significantly increased only in macrophage depleted MI compared to sham (heart weight/body weight (mg/g); 5.5±0.8 vs 4.6±0.4, p=0.02). Male macrophage-depleted mice and 50% of female mice exhibited a dense intracavity thrombus adherent to the infarct wall after MI, which showed significantly higher 18F-NaF uptake at 4wks compared to PBS MI (%ID/g; 6.0±4.9 vs 0.4±0.3; p&lt;0.001), highlighting necessity of timely infiltration of the infarct with inflammatory macrophages for adequate cardiac repair.

Conclusion
By 4d after reperfused MI, the myocardium exhibits signs of inflammation resolution and decline of CCR2+ cell content in mice. Single time macrophage depletion prior to MI delays but does not prevent infiltration of CCR2+ inflammatory macrophages into infarct territories. Male mice are at higher risk of LV thrombus formation, demonstrating sex dependent differences in cardiac repair, which seem to be independent from the amount of CCR+ macrophages.