Evaluation Of Cardiac Sarcoidosis Research Articles

Radiology: Cardiothoracic Imaging Highlights 2023.

Radiology: Cardiothoracic Imaging publishes novel research and technical developments in cardiac, thoracic, and vascular imaging. The journal published many innovative studies during 2023 and achieved an impact factor for the first time since its inaugural issue in 2019, with an impact factor of 7.0. The current review article, led by the Radiology: Cardiothoracic Imaging trainee editorial board, highlights the most impactful articles published in the journal between November 2022 and October 2023. The review encompasses various aspects of coronary CT, photon-counting detector CT, PET/MRI, cardiac MRI, congenital heart disease, vascular imaging, thoracic imaging, artificial intelligence, and health services research. Key highlights include the potential for photon-counting detector CT to reduce contrast media volumes, utility of combined PET/MRI in the evaluation of cardiac sarcoidosis, the prognostic value of left atrial late gadolinium enhancement at MRI in predicting incident atrial fibrillation, the utility of an artificial intelligence tool to optimize detection of incidental pulmonary embolism, and standardization of medical terminology for cardiac CT. Ongoing research and future directions include evaluation of novel PET tracers for assessment of myocardial fibrosis, deployment of AI tools in clinical cardiovascular imaging workflows, and growing awareness of the need to improve environmental sustainability in imaging. Keywords: Coronary CT, Photon-counting Detector CT, PET/MRI, Cardiac MRI, Congenital Heart Disease, Vascular Imaging, Thoracic Imaging, Artificial Intelligence, Health Services Research © RSNA, 2024.

Combined FDG PET/MRI versus Standard-of-Care Imaging in the Evaluation of Cardiac Sarcoidosis

Combined FDG PET/MRI versus Standard-of-Care Imaging in the Evaluation of Cardiac Sarcoidosis

Diagnostic values of delayed additional FDG PET/CT scan in the evaluation of cardiac sarcoidosis.

This study aimed to compare the contribution of 18F-fluorodepxyglucose (FDG) positron (PET)/ computed tomography (CT) acquisition of early and delayed scans in patients with cardiac sarcoidosis (CS). Twenty-three patients with CS (median age: 69years; 11 women) were retrospectively evaluated using dual-phase FDG PET/CT. All patients were instructed to consume a low-carbohydrate diet followed by fasting for 18h before FDG injection to reduce physiological myocardial uptake. PET/CT was acquired at 60min (early) and 100min (delayed) after FDG administration. Focal and focal on diffuse uptake on visual analysis was considered positive for CS. A semi-quantitative analysis was performed using the maximum standardized uptake value (SUVmax) of the cardiac lesion and the mean SUV (SUVmean) of the blood pool. Significant myocardial FDG uptake was observed in 21 patients (91.3%) in the early acquisition group and in 23 patients in the delayed scan group (100%). Compared to the early scan, the delayed scan showed a significantly higher SUVmax of the cardiac lesion [median, 4.0; IQR (interquartile range, 2.9 to 7.0) vs. 5.8 (IQR 3.7 to 10.1); P = 0.0030] and a significantly lower SUVmean of blood pool [median, 1.3 (IQR, 1.2 to 1.4) vs. 1.1 (IQR, 0.9 to 1.2); P < 0.0001]. Delayed FDG PET/CT acquisition improves detection accuracy in patients with CS compared to early scans with washout of the blood pool activity. Therefore, it can contribute to a more accurate assessment of CS.

Cardiac sarcoidosis evaluation and characterization with cardiac magnetic resonance

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Sarcoidosis is a multisystemic inflammatory disease, which accounts for substantial morbimortality. Cardiac involvement portends a worse prognosis. A major limitation in the evaluation of cardiac sarcoidosis is that no gold standard clinical diagnostic criteria exists. Cardiac magnetic resonance (CMR) may be indicated in patients with suspected cardiac involvement as a diagnostic and prognostic tool. Purpose The aim of this study was to characterize the features of cardiac involvement of sarcoidosis in patients with stablished diagnosis of the systemic disease, as well as to describe changes observed. Methods A multicenter, 6-years prospective study of all patients with sarcoidosis who performed CMR to evaluate possible cardiac involvement. We followed a protocol to evaluate the left and right ventricles (VE; RV) both anatomically and functionally, T2- weighted STIR sequences to evaluate myocardial edema and presence of late gadolinium enhancement(LGE). Results A total of 20 patients were included. Female patients accounted for 75% of the cases, and the mean age was 53 ± 15 years old. A majority of the patients (90%) had preserved LV (mean LV ejection fraction(EF)63 ± 6%) and RV ejection fraction (mean RV EF 62 ± 7%). Patients observed presented with mean LV end diastolic indexed volume(EDIV) of 72 ± 19 mL/m2 and mean RV EDIV of 63 ± 18mL/m2, with only one patient presenting with LV dilation(LV EDIV 138mL/m2) and two with RV dilation (mean RV EDIV 107 ± 6mL/m2). Possible features of cardiac sarcoidosis were present in 10% (n = 2) of patients. One of them presented with biventricular dilation and severe ejection fraction depression(LV EF 22% and RV EF 28%). LGE was observed in these two patients, with one presenting with an intramyocardial lesion with nodular appearance on the apical inferior segment and the other patient having its distribution characterized with two different patterns: linear appearance on the septal intramyocardium and subepicardial on the basal and mid segments of the inferior wall. On STIR sequences none of the patients presented with hypersignal suggestive of edema. None of them presented with left atrium dilation. Conclusion CMR provides a noninvasive and multidimensional assessment of the heart for evaluation of cardiac sarcoidosis. In our population of patients with sarcoidosis but without established cardiac involvement diagnosis, CMR allowed a 10% increasement on the diagnosis of cardiac sarcoidosis. CMR myocardial fibrosis detection allowed a better stratification of patients with sarcoidosis.

FLT-PET for the assessment of systemic sarcoidosis including cardiac and CNS involvement: a prospective study with comparison to FDG-PET

Background2-deoxy-2-[18F]fluoro-d-glucose’s (FDG) biodistribution limits the evaluation of cardiac sarcoidosis (CS) and neurosarcoidosis (NS). While protocols for cardiac suppression exist, they can be inconvenient for patients and lead to incomplete cardiac suppression in many cases. Furthermore, FDG PET is limited in the detection of neurosarcoidosis due to an inability to suppress high level of physiological uptake within the brain. 3′-deoxy-3′-[18F]fluorothymidine (FLT) has been shown to accumulate in sarcoidosis lesions and this tracer lacks significant physiological myocardial and brain uptake, suggesting that this tracer may be useful for the assessment of sarcoidosis, including CS and NS, without the need for patient preparation. This prospective pilot study examined the performance of FLT vs FDG PET for systemic sarcoidosis, including cardiac and neural involvement.Materials and methodsFourteen subjects with sarcoidosis were prospectively recruited and imaged with FDG- and FLT-PET. Two blinded, experienced readers independently reviewed the FLT-PET and FDG-PET images. Lesion distribution was compared between FLT and FDG. Agreement between FLT- and FDG-PET was determined using Cohen’s kappa and the intra-class correlation coefficient. Inter-observer variability of FLT and FDG-PET was assessed.ResultsTwelve subjects had CS as per Heart Rhythm Society criteria and 1 had NS. FLT-PET was positive in 12 (86%), and FDG-PET in 11 (79%), with cardiac uptake present in 6 (50%) and 7 (58%) of subjects with CS, respectively. The subject with NS demonstrated uptake on both FLT and FDG-PET, with more lesions on FLT. There were no significant differences in the anatomical distribution of lesions between FLT and FDG. SUVs were significantly (p < 0.001) higher for FDG than FLT (5.8 ± 3.0 vs 2.3 ± 1.1, respectively), but not (p = 0.90) after adjusting for blood pool activity (2.8 ± 1.4 vs 2.8 ± 1.1, respectively). Agreement between FLT- and FDG-PET was good to excellent for the diagnosis of sarcoidosis, lung involvement, CS, and NS (κ = 0.76, 0.69, 0.86, and 1.0, respectively). Inter-observer agreement for FLT was excellent for diagnosing sarcoidosis, CS and NS (κ = 0.81, 0.85, and 1.0, respectively) and comparable to that of FDG.ConclusionsFLT-PET may be useful for the assessment of systemic sarcoidosis, as well as cardiac and neural involvement.

Discrepancy between significant fibrosis and active inflammation in patients with cardiac sarcoidosis: combined and image fusion analysis of cardiac magnetic resonance and 18F fluorodeoxyglucose positron emission tomography

BackgroundDiagnosis and evaluation of cardiac sarcoidosis (CS) are mainly based on the combined use of cardiac magnetic resonance imaging (CMR) and 18F fludeoxyglucose positron emission tomography (FDG). Though these modalities can detect the pathological feature of the disease, combined assessment has not been fully examined. Multimodality image fusion is known to be useful for further comprehension, while most image interpretation is performed with a side by side comparison in clinical routine. We investigated the similarity and discrepancy of active inflammation, regional fibrosis, and wall function by image fusion of CMR and FDG.MethodsPatients with CS who underwent both CMR and FDG were retrospectively enrolled. The extent of myocardial late gadolinium enhancement (LGE) in left ventricle (LGE volume), cardiac function, and volume (left ventricular ejection fraction, LVEF; end-diastolic volume, EDV) was measured from CMR. The FDG uptake in whole myocardium (whole SUVmax), cardiac metabolic volume (CMV), and cardiac metabolic activity (CMA) was calculated from FDG. CMR and FDG were fused and divided into AHA 17 model for segmental analysis. Wall motion, the magnitude of LGE in myocardial wall (LGE%wall), and corresponding FDG uptake (segmental SUVmax) were analyzed.ResultsForty-one patients were retrospectively enrolled. In patients with FDG uptake, LVEF inversely correlated to LGE volume and positively correlated to SUVmax (r = − 0.56, p < 0.0001, and r = 0.08, p = 0.048, respectively). Discrepancy between LGE volume and CMV showed a significant positive correlation to whole SUVmax and CMA (r = 0.49, p < 0.0001, and r = 0.96, p < 0.0001, respectively). In image fusion analysis, segmental SUVmax showed a significant inverse correlation to LGE%wall (Spearman’s rank correlation coefficient; r = − 0.15, p = 0.008). LGE%wall also showed significant inverse correlation to wall motion (r = − 0.13, p = 0.0011).ConclusionCombined and fusion analysis with CMR and FDG demonstrated the discrepancy of myocardial inflammation and extensive fibrosis. Active inflammation was present in the earlier stage of myocardial fibrosis and was found to be less in the wall with advanced fibrosis and remodeling. Combined analysis of CMR and FDG can incrementally reclassify the pathological stage of CS.

Initial Experience With Simultaneous 18F-FDG PET/MRI in the Evaluation of Cardiac Sarcoidosis and Myocarditis.

The purpose of this study was to compare combined PET/MRI with PET/CT and cardiac MRI in the evaluation of cardiac sarcoidosis and myocarditis. Ten patients (4 men and 6 women; 56.1 ± 9.6 years old) were prospectively enrolled for evaluation of suspected cardiac sarcoidosis or myocarditis. Written informed consent was obtained. Following administration of 9.9 ± 0.9 mCi F-FDG, patients underwent standard cardiac PET/CT followed by combined PET/MRI using a simultaneous 3-T scanner. Cardiac MRI sequences included ECG-triggered cine SSFP, T2-weighted, and late gadolinium-enhanced imaging. Myocardial involvement was assessed with separate analysis of combined PET/MRI, PET/CT, and cardiac MRI data using dedicated postprocessing software. Estimates of radiation dose were derived from the applied doses of F-FDG and CT protocol parameters. Imaging was acquired with a delay from F-FDG injection of 90.2 ± 27.4 minutes for PET/CT and 207.7 ± 40.3 minutes for PET/MRI. Total scan time for PET/MRI was significantly longer than for PET/CT (81.4 ± 14.8 vs 12.0 minutes, P < 0.001). Total effective radiation dose was significantly lower for PET/MRI compared with PET/CT (6.9 ± 0.6 vs 8.2 ± 1.1 mSv, P = 0.007). There was no significant difference in the number of positive cases identified between combined PET/MRI (n = 10 [100%]), PET/CT (n = 6 [60%]), and cardiac MRI (n = 8 [80%]), P = 0.091. Simultaneous cardiac PET/MRI is feasible in the evaluation of cardiac sarcoidosis and myocarditis achieving diagnostic image quality.

Impact of Patient Preparation on the Diagnostic Performance of 18F-FDG PET in Cardiac Sarcoidosis

F-FDG PET/CT is a valuable diagnostic tool in the evaluation of cardiac sarcoidosis. Appropriate patient preparation is important because the diagnostic accuracy of this procedure depends on adequate suppression of physiologic glucose uptake. This systematic review and meta-analysis aims to assess the effect of different patient preparations on the diagnostic accuracy of F-FDG PET/CT in cardiac sarcoidosis. We searched the PubMed/MEDLINE, Embase, and Cinicaltrials.gov databases. Sixteen studies (n = 559) were identified to be suitable for this systemic review. Studies were stratified according to fasting duration and means of physiologic suppression of F-FDG by cardiac tissue, which involves the use of heparin infusion or high-fat, low-carbohydrate diet before imaging. Study quality was assessed using the QUADAS-2 tool. Forest plots of sensitivity and specificity were calculated in Review Manager 5.3, and a random-effects hierarchical summary receiver operating characteristic model was created using MetaDiSc. Meta-regression was performed to investigate sources of heterogeneity. PET/CT had an overall Specificity of 0.75 (95% confidence interval [CI], 0.69-0.80) and specificity of 0.81 (95% CI, 0.76-0.85) for the diagnosis of cardiac sarcoidosis. This modest diagnostic accuracy was attributed to the inclusion of large single study in which a short fasting duration before scanning likely influenced its sensitivity. Its exclusion resulted in an overall sensitivity of 0.81 (95% CI, 0.76-0.86) and specificity of 0.82 (95% CI, 0.77-0.86). Meta-regression showed that the diagnostic odds ratio was significantly affected by fasting time and heparin administration before scanning (P = 0.01, 0.02) but not with high-fat, low-carbohydrate diet (P = 0.17). F-FDG PET/CT plays an integral role in the diagnosis of cardiac sarcoidosis. Diagnostic accuracy is affected by fasting duration and means of cardiomyocyte glucose uptake suppression before scanning.

Quantitative interpretation of FDG PET/CT with myocardial perfusion imaging increases diagnostic information in the evaluation of cardiac sarcoidosis

BackgroundFDG PET/CT with myocardial perfusion imaging is a useful method for evaluating cardiac sarcoidosis (CS), but interpretation is not standardized. We developed a method for quantification of cardiac FDG PET/CT and evaluated its relationship to conventional interpretation, perfusion defects, clinical events, and immunosuppressive treatment. Methods and ResultsFDG PET/CT with MPI studies performed for CS (n = 38) were retrospectively compared to negative control studies acquired for oncologic indications (n = 10). Quantitative measures of FDG volume-intensity (Cardiac Metabolic Activity, CMA) was performed using standardized uptake values (SUVs). CMA (477.7 ± 909 vs 0.55 ± 2.1 vs 0.3 ± 0.3 g glucose, P = .02) was significantly greater in visually FDG-positive studies compared to visually negative and oncologic negative studies. Among patients with CS, CMA was greater in studies with an EF < 50% (760.3 ± 1,148 vs 87.4 ± 161 g glucose, P = .03) and preceding an adverse clinical event (1,095 ± 1,253 vs 73 ± 144 g glucose, P = .006). CMA was the only independent predictor of events by multivariate analysis. In patients with repeat examinations (n = 7), CMA decreased with prednisone treatment in 5 of 6 patients. ConclusionsQuantification of FDG uptake in CS correlates with lower EFs, clinical events, and immunosuppression treatment.

The invisible made visible: multi-modality imaging in the evaluation of cardiac sarcoidosis

A 34-year-old male with a radiographic ( Panel A ) and histological diagnosis of pulmonary sarcoidosis presented with symptomatic complete atrioventricular block ( Panel B ) . Right ventricular endomyocardial biopsy was negative for granulomas. Delayed gadolinium enhancement cardiac magnetic resonance imaging showed focal areas of scar in the basal and apical inferior walls …

Cardiac imaging in myocardial sarcoidosis and other cardiomyopathies

The clinical role of emerging imaging technologies for diagnosing cardiac sarcoidosis and other cardiomyopathies is evolving. An up-to-date review of the role of various imaging modalities in the evaluation of cardiac sarcoidosis and other cardiomyopathies is presented. No study prospectively established the accuracy of each of the various techniques for diagnosing myocardial involvement in patients with suspected cardiac sarcoidosis. Cardiac magnetic resonance imaging (CMR) is demonstrated to have a sensitivity of 100% and specificity of approximately 80%, and positive predictive value of approximately 55% in diagnosing cardiac sarcoidosis. Recent studies have shown that 18F-2-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) has 100% sensitivity of detecting earlier stages of sarcoidosis. Both the FDG-PET and CMR may provide complementary information for the diagnosis and assessment of efficacy of therapy in patients with cardiac involvement from sarcoidosis. Clinical and subclinical cardiac involvement is common among patients with sarcoidosis. A structured clinical assessment incorporating advanced cardiac imaging with CMR and FDG-PET scanning is more sensitive than the established clinical criteria. CMR is an established imaging modality in the diagnosis of various other cardiomyopathies. Well designed prospective clinical trials are awaited to define the exact role of these imaging studies in the diagnosis and guidance of therapy.

Cardiac magnetic resonance imaging in the evaluation of cardiac sarcoidosis: an Australian single‐centre experience

Cardiac involvement in systemic sarcoidosis is common; however, current diagnostic tools are imprecise. Recognition of cardiac sarcoidosis (CS) is important as it has a relatively poor prognosis. Gadolinium-enhanced cardiac magnetic resonance imaging (Gad-CMR) is emerging as an excellent technique in determining the presence of and extent to which cardiac muscle is affected by sarcoidosis. A retrospective analysis was performed on all patients with biopsy-proven systemic sarcoidosis referred for Gad-CMR scanning to evaluate potential cardiac involvement. All patients also underwent an electrocardiogram, Holter monitor and echocardiography. Gallium-67 radionuclide investigation, positron emission tomography and cardiac biopsy were ordered at the discretion of the treating physician. Eleven of the 20 patients had Gad-CMR images supportive of the diagnosis of CS. Eight of these 11 patients met the Japanese Ministry of Health and Welfare (JMHW) criteria for the diagnosis of CS; three abnormal Gad-CME scans consistent with diagnosis of CS were seen in patients who did not meet JMHW criteria. No patients with normal Gad-CMR scan met JMHW criteria for CS. These findings suggest that Gad-CMR is potentially superior to the JMHW criteria in the diagnosis of cardiac sarcoidosis.

Magnetic resonance imaging and nuclear imaging in sarcoidosis.

MRI has become of great importance in the study of several aspects of sarcoidosis. The main development has taken place in the assessment of neurosarcoidosis, but MRI may be also useful in the evaluation of sarcoidosis of the bone, muscle, heart, and intrathoracic. Nuclear imaging in sarcoidosis acquired a great expansion with the introduction of (67)gallium scanning as a marker of activity. Although its current use has decreased, it is still very helpful in particular situations of the disease. Other more recently introduced nuclear imaging techniques may have a role in the evaluation of cardiac sarcoidosis and in the assessment of the extension of the disease.