A case of longitudinal care of a patient with cardiac sarcoidosis

Cardiac sarcoidosis has long been an evasive diagnosis with a spectrum of clinical presentations that extend from asymptomatic to ventricular arrhythmias and sudden cardiac death. The diagnosis has traditionally relied on histology which suffers from the low sensitivity of endomyocardial biopsy due to the patchy nature of the disease in addition to its invasive nature. Due to significant advancements in imaging, it is now possible to accurately identify cardiac sarcoidosis using non-invasive imaging modalities even without histological confirmation. Emerging guidelines are highlighting the role of multimodality imaging in the diagnosis and management of this challenging entity. We present the case of a 36-year-old man known to have sarcoidosis in which a variety of imaging modalities not only assisted in the diagnosis of cardiac sarcoidosis, but also played a key role in the monitoring of disease activity and response to therapy.     

Usefulness of fasting 18F-FDG PET in identification of cardiac sarcoidosis.

Cardiac PET using (18)F-FDG under fasting conditions (fasting (18)F-FDG PET) is a promising technique for identification of cardiac sarcoidosis and assessment of disease activity. The aim of this study was to investigate the usefulness of fasting (18)F-FDG PET in detecting inflammatory lesions of cardiac sarcoidosis from a pathophysiologic standpoint. METHODS: Twenty-two patients with systemic sarcoidosis were classified into 2 groups of 11 each according to the presence or absence of sarcoid heart disease. Cardiac sarcoidosis was diagnosed according to the Japanese Ministry of Health and Welfare guidelines for diagnosing cardiac sarcoidosis with the exception of scintigraphic criteria. Nuclear cardiac imaging with fasting (18)F-FDG PET, (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) SPECT, and (67)Ga scintigraphy were performed in all patients. PET and SPECT images were divided into 13 myocardial segments and the standardized uptake value (SUV) of (18)F-FDG was calculated and defect scores (DS) for (99m)Tc-MIBI uptake were assessed for each segment. The total SUV (T-SUV) and total DS (TDS) were calculated as the sum of measurements for all 13 segments, and the diagnostic accuracy of fasting (18)F-FDG PET was compared with that of the other nuclear imaging modalities. In addition, pathophysiologic relationships between inflammatory activity and myocardial damage were examined by segmental comparative study using the SUV and DS. RESULTS: In patients with cardiac sarcoidosis, fasting (18)F-FDG PET revealed a higher frequency of abnormal myocardial segments than (99m)Tc-MIBI SPECT (mean number of abnormal segments per patient: 6.6 +/- 3.0 vs. 3.0 +/- 3.2 [mean +/- SD], P < 0.05). The sensitivity of fasting (18)F-FDG PET in detecting cardiac sarcoidosis was 100%, significantly higher than that of (99m)Tc-MIBI SPECT (63.6%) or (67)Ga scintigraphy (36.3%). The accuracy of fasting (18)F-FDG PET was significantly higher than (67)Ga scintigraphy. The T-SUV demonstrated a good linear correlation with serum angiotensin-converting enzyme levels (r = 0.83, P < 0.01), and the TDS showed a significant negative correlation with the left ventricular ejection fraction (r = -0.82, P < 0.01). In abnormal myocardial segments on the nuclear scan, the SUV showed a significant negative correlation with the DS (r = -0.63, P < 0.0001). CONCLUSION: This study suggests that fasting (18)F-FDG PET can detect the early stage of cardiac sarcoidosis, in which fewer perfusion abnormalities and high inflammatory activity are noted, before advanced myocardial impairment.     

CT imaging of myocardial perfusion: Possibilities and perspectives

Functional imaging in patients with suspected or known coronary artery disease (CAD) is crucial for the identification of patients who could benefit from coronary revascularization. Several studies demonstrated the high diagnostic accuracy of Single-photon-emission computed tomography myocardial perfusion imaging, stress perfusion magnetic resonance imaging, and of invasive FFR measurements for the detection of hemodynamic relevant stenosis. Cardiac computed tomography (CT) used to be limited to coronary angiography (CTA); current guidelines recommend CTA only for the exclusion of CAD. Technological advances now offer the possibility to assess myocardial perfusion by computed tomography (CT-MPI). Though different acquisition protocols and post-processing algorithms still have to be evaluated, initial clinical studies could already show a diagnostic accuracy comparable to the established imaging modalities. Thus, cardiac CT may offer a combined approach of anatomical and functional imaging. Beside the need for further studies, especially on the prognostic value of CT-MPI to stratify future cardiovascular events, the comparatively high radiation exposure and additional administration of contrast agent has to be taken in account.     

Isolated cardiac sarcoidosis: A focused review of an under-recognized entity

There is accumulating evidence for the existence of a phenotype of isolated cardiac sarcoidosis (ICS), or sarcoidosis that only involves the heart. In the absence of biopsy-confirmed cardiac sarcoidosis (CS), existing diagnostic criteria require the presence of extra-cardiac sarcoidosis as an inclusion criterion for the diagnosis of CS. Consequently, in the absence of a positive endomyocardial biopsy, ICS is not diagnosable by current guidelines. Therefore, there is uncertainty regarding the epidemiology, pathobiology, clinical characteristics, prognosis, and optimal treatment of ICS. This review will summarize the available data related to the prevalence and prognosis of ICS and will discuss challenges surrounding the diagnosis and management of this under-recognized entity.     

Usefulness of 67Ga SPECT and integrated low-dose CT scanning (SPECT/CT) in the diagnosis of cardiac sarcoidosis

Objective We performed ⁶⁷Gallium (Ga) single-photon emission computed tomography (SPECT) with integrated low-dose computed tomography (CT) for the interpretation of myocardial outline to investigate the value of co-registered fusion imaging using a hybrid system (SPECT/CT) in patients with cardiac sarcoidosis. Methods SPECT/CT of the region in question was performed with VG Hawkeye. The subjects in this study were 37 patients [mean (±SD) age 61.0 ± 13.0 years; 12 men and 25 women], 13 of whom had a clinical diagnosis of cardiac sarcoidosis and 24 a negative diagnosis. An intravenous injection of Ga (dosage 111 MBq) was performed on patients 48 h or 72 h before obtaining static planar images of the whole-body and the SPECT/CT scan. Results Abnormal Ga uptake in the myocardium was observed in 10 of the 13 subjects with true sarcoidosis, and in 11 of 24 with negative sarcoidosis without CT fusion. The sensitivity without CT fusion was 77%, the specificity 54%, and the accuracy 62%. Use of SPECT/CT changed the diagnosis only in a patient with true sarcoidosis, and changed the diagnosis in eight patients with negative sarcoidosis. The sensitivity with CT fusion was 69%, the specificity 79%, and the accuracy 76%. The difference in diagnostic accuracy was statistically significant (McNemar's test, P = 0.039). Conclusions SPECT scanning using Ga and integrated low-dose CT is a very useful diagnostic imaging technique because it improves the diagnostic specificity of Ga SPECT to allow the highly specific diagnosis of cardiac sarcoidosis.     

Myocardial imaging with 18F-fluoro-2-deoxyglucose positron emission tomography and magnetic resonance imaging in sarcoidosis

Purpose Despite accumulating reports on the clinical value of ¹⁸F-fluoro-2-deoxyglucose positron emission tomography (¹⁸F-FDG PET) and magnetic resonance imaging (MRI) in the assessment of cardiac sarcoidosis, no studies have systematically compared the images of these modalities. Methods Twenty-one consecutive patients with suspected cardiac sarcoidosis underwent cardiac examinations that included ¹⁸F-FDG PET and MRI. The association of ¹⁸F-FDG PET and MRI findings with blood sampling data such as serum angiotensin converting enzyme levels was also evaluated. Results Eight of 21 patients were diagnosed as having cardiac sarcoidosis according to the Japanese Ministry of Health and Welfare Guidelines for Diagnosing Cardiac Sarcoidosis. Sensitivity and specificity for diagnosing cardiac sarcoidosis were 87.5 and 38.5%, respectively, for ¹⁸F-FDG PET, and 75 and 76.9%, respectively, for MRI. When the ¹⁸F-FDG PET and MRI images were compared, 16 of 21 patients showed positive findings in one (n = 8) or both (n = 8) of the two modalities. In eight patients with positive findings on both images, the distribution of the findings differed among all eight cases. The presence of positive findings on ¹⁸F-FDG PET was associated with elevated serum angiotensin-converting enzyme levels; this association was not demonstrated on MRI. Conclusions Both ¹⁸F-FDG PET and MRI provided high sensitivity for diagnosing cardiac sarcoidosis in patients with suspected cardiac involvement, but the specificity of ¹⁸F-FDG PET was not as high as previously reported. The different distributions of the findings in the two modalities suggest the potential of ¹⁸F-FDG PET and MRI in detecting different pathological processes in the heart.     

Comprehensive Updates in the Role of Imaging for Multiple Myeloma Management Based on Recent International Guidelines

The diagnostic and treatment methods of multiple myeloma (MM) have been rapidly evolving owing to advances in imaging techniques and new therapeutic agents. Imaging has begun to play an important role in the management of MM, and international guidelines are frequently updated. Since the publication of 2015 International Myeloma Working Group (IMWG) criteria for the diagnosis of MM, whole-body magnetic resonance imaging (MRI) or low-dose whole-body computed tomography (CT) and ¹⁸F-fluorodeoxyglucose positron emission tomography/CT have entered the mainstream as diagnostic and treatment response assessment tools. The 2019 IMWG guidelines also provide imaging recommendations for various clinical settings. Accordingly, radiologists have become a key component of MM management. In this review, we provide an overview of updates in the MM field with an emphasis on imaging modalities.     

Effectiveness of prolonged fasting 18f-FDG PET-CT in the detection of cardiac sarcoidosis

Background  

The Japanese Ministry of Health and Welfare guidelines (JMHWG) are currently the standard used to diagnose cardiac sarcoidosis. JMHWG incorporate ⁶⁷Gallium scintigraphy as a minor criterion, while fasting ¹⁸fluorine-2-fluro-2-deoxy-d-glucose (FDG) PET is not included. As there is no published data comparing the accuracy of prolonged fasting FDG PET-CT (PF-PET) and Gallium scintigraphy for detecting active cardiac sarcoidosis, we sought to compare these two modalities.     

Establishment of Animal Models with Orthotopic Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most serious health problems worldwide. Many researchers have investigated HCC at the level of genes, ribonucleic acid, proteins, cells, and animals. The resultant development of animal models and monitoring methods has improved the effectiveness of guidelines provided to researchers working with preclinical HCC models. HCC in animal models and clinical patients is monitored by various current imaging modalities such as ultrasound (US) imaging, computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), positron emission tomography (PET) and bioluminescence imaging (BLI). These techniques are currently used for both preclinical and clinical assessment, and provide valuable diagnostic information. In this article, we have mainly reviewed the established animal models and the assessment of orthotopic HCC using imaging modalities. Additionally, we have introduced a method of orthotopic HCC rat model developed in our laboratory. We have furthermore evaluated the occurrence of tumor mass using molecular imaging techniques.     

The essence of the Japan Radiological Society/Japanese College of Radiology Imaging Guideline

Diagnostic imaging is undoubtedly important in modern medicine, and final clinical decisions are often made based on it. Fortunately, Japan has the highest numbers of diagnostic imaging instruments, such as CT and MRI devices, and boasts easy access to them as well as a high level of diagnostic accuracy. In consequence, a very large number of imaging examinations are performed, but diagnostic instruments are installed in so many medical facilities that expert management of these examinations tends to be insufficient. Particularly, in order to avoid risks, clinicians have recently become indifferent to indications of imaging modalities and tend to rely on CT or MRI resulting in increasing the number of imaging examinations in Japan. This is a serious problem from the viewpoints of avoidance of unnecessary exposure and medical economy. Under these circumstances, the Japan Radiological Society and Japanese College of Radiology jointly initiated the preparation of new guidelines for diagnostic imaging. However, the field of diagnostic imaging is extremely wide, and it is impossible to cover all diseases. Therefore, in drafting the guidelines, we selected important diseases and focused on “showing evidence and suggestions in the form of clinical questions (CQs)” concerning clinically encountered questions and “describing routine imaging techniques presently considered to be standards to guarantee the quality of imaging examinations”. In so doing, we adhered to the basic principles of assuming the readers to be “radiologists specializing in diagnostic imaging”, “simultaneously respecting the global standards and attending to the situation in Japan”, and “making the guidelines consistent with those of other scientific societies related to imaging”. As a result, the guidelines became the largest ever, consisting of 152 CQs, nine areas of imaging techniques, and seven reviews, but no other guidelines in the world summarize problems concerning diagnostic imaging in the form of CQs. In this sense, the guidelines are considered to reflect the abilities of diagnostic radiologists in Japan. The contents of the guidelines are essential knowledge for radiologists, but we believe that they are also of use to general clinicians and clinical radiological technicians. While the number and contents of CQs are still insufficient, and while chapters such as those on imaging in children and emergency imaging need to be supplemented, the guidelines will be serially improved through future revisions. Lastly, we would like to extend our sincere thanks to the 153 members of the drafting committee who authored the guidelines, 12 committee chairpersons who coordinated their efforts, six members of the secretariat, and affiliates of related scientific societies who performed external evaluation.     

Assessment of ischemic heart disease with electron-beam CT and MR imaging

Anatomical and functional information derived from diagnostic modalities is essential in cardiac imaging. Electron-beam CT and MR imaging have played a role in the assessment of cardiac function, and recent developments in both modalities have permitted non-invasive visualization of coronary artery stenosis, which previously had been demonstrated exclusively by catheter coronary angiography. In this article, coronary artery imaging and cardiac functional imaging were reviewed by focusing on new technical developments in the screening of coronary atherosclerosis leading to acute coronary syndrome. Quantitative assessment of coronary calcifications by electron-beam CT has already become one of the most useful techniques for predicting the degree of coronary atherosclerosis and the risk of coronary events in individual patients. Electron-beam CT and MR imaging have also provided non-invasive clinical tools with which to demonstrate coronary artery stenosis. Visualization and characterization of atheromatous plaque at the coronary artery has recently been attempted with MR imaging, since this might lead to the detection of coronary artery plaque that was likely to rupture, thereby possibly predicting and preventing acute coronary syndrome in asymptomatic individuals. Although electron-beam CT and MR imaging have not been fully incorporated into routine clinical practice, each could serve as a comprehensive modality for the assessment of ischemic heart disease.     

ACR Appropriateness Criteria Imaging in the Diagnosis of Thoracic Outlet Syndrome

Thoracic outlet syndrome is a clinical entity characterized by compression of the neurovascular bundle, and may be associated with additional findings such as venous thrombosis, arterial stenosis, or neurologic symptoms. The goal of imaging is to localize the site of compression, the compressing structure, and the compressed organ or vessel, while excluding common mimics. A literature review is provided of current indications for diagnostic imaging, with discussion of potential limitations and benefits of the respective modalities.The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. In this document, we provided guidelines for use of various imaging modalities for assessment of thoracic outlet syndrome.     

MRT bei kardialer Sarkoidose und Amyloidose

Clinical/methodical issue

Sarcoidosis and amyloidosis are both multisystem disorders, which may involve the heart; however, isolated cardiac disease is rare. Diagnosis of cardiac sarcoidosis and amyloidosis is crucial because the patient prognosis is dependent on cardiac involvement and early treatment.

Standard radiological methods

Echocardiography is the first line imaging modality in the diagnostic work-up of both diseases, possibly giving hints towards the correct diagnosis. Besides myocardial biopsy and radionuclide studies cardiac magnetic resonance imaging (MRI) is routinely performed in patients suspect of having infiltrative cardiomyopathy.

Methodical innovations

The T1 mapping procedure is currently being evaluated as a new technique for detection and quantification of global myocardial enhancement, as seen in cardiac amyloidosis.

Performance

Sensitivities and specificities for detection of cardiac sarcoidosis and amyloidosis can be significantly improved by MRI, especially with late gadolinium enhancement (LGE) imaging. In cardiac sarcoidosis the use of LGE is outcome-related while in amyloidosis analysis of T1-mapping may be of prognostic value.

Practical recommendations

If cardiac involvement in sarcoidosis or amyloidosis is suspected cardiac MRI including LGE should be performed for establishing the diagnosis.     

Pictorial review: electron beam computed tomography and multislice spiral computed tomography for cardiac imaging

Electron beam computed tomography (EBCT) revolutionized cardiac imaging by combining a constant high temporal resolution with prospective ECG triggering. For years, EBCT was the primary technique for some non-invasive diagnostic cardiac procedures such as calcium scoring and non-invasive angiography of the coronary arteries. Multislice spiral computed tomography (MSCT) on the other hand significantly advanced cardiac imaging through high volume coverage, improved spatial resolution and retrospective ECG gating. This pictorial review will illustrate the basic differences between both modalities with special emphasis to their image quality. Several experimental and clinical examples demonstrate the strengths and limitations of both imaging modalities in an intraindividual comparison for a broad range of diagnostic applications such as coronary artery calcium scoring, coronary angiography including stent visualization as well as functional assessment of the cardiac ventricles and valves. In general, our examples indicate that EBCT suffers from a number of shortcomings such as limited spatial resolution and a low contrast-to-noise ratio. Thus, EBCT should now only be used in selected cases where a constant high temporal resolution is a crucial issue, such as dynamic (cine) imaging. Due to isotropic submillimeter spatial resolution and retrospective data selection MSCT seems to be the non-invasive method of choice for cardiac imaging in general, and for assessment of the coronary arteries in particular. However, technical developments are still needed to further improve the temporal resolution in MSCT and to reduce the substantial radiation exposure.     

¹⁸F-Fluoro-2-deoxyglucose positron emission tomography in cardiac sarcoidosis

Cardiac sarcoidosis (CS) is a rare and potentially life-threatening disease that causes conduction disturbance, systolic dysfunction, and most notably sudden cardiac death. Accurate diagnosis of CS is thus mandatory; however, a reliable approach that enables diagnosis of CS with high sensitivity and specificity has yet to be established. Recent studies have demonstrated the promising potential of ¹⁸F-fluoro-2-deoxyglucose positron emission tomography (¹⁸F-FDG PET) in the diagnosis and assessment of CS. Indeed, ¹⁸F-FDG PET provides a wide variety of advantages over previous imaging modalities; however, there are pitfalls and limitations that should be recognized. In this review article, (1) the rationale for ¹⁸F-FDG PET application in CS, (2) suitable pretest preparations, and (3) evaluation protocols for the ¹⁸F-FDG PET images obtained will be addressed. In particular, sufficient suppression of physiological ¹⁸F-FDG uptake in the heart is essential for accurate assessment of CS. Also, (4) recent studies addressing the diagnostic role of ¹⁸F-FDG PET and (5) the clinically important differences between ¹⁸F-FDG PET and other imaging technologies will be reviewed. For example, active sarcoid lesions and their response to steroid treatment will be better detected by ¹⁸F-FDG PET, whereas fibrotic lesions might be shown more clearly by magnetic resonance imaging or other nuclear myocardial perfusion imaging. In the last decade, ¹⁸F-FDG PET has substantially enhanced detection of CS; however, CS would be better evaluated by a combination of multiple modalities. In the future, advances in ¹⁸F-FDG PET and other emerging imaging modalities are expected to enable better management of patients with sarcoidosis.     

Role of imaging in the diagnosis and management of patients with cardiac amyloidosis: State of the art review and focus on emerging nuclear techniques

Amyloidosis is an infiltrative disease characterized by deposition of amyloid fibrils within the extracellular tissue of one or multiple organs. Involvement of the heart, cardiac amyloidosis, is recognized as a common cause of restrictive cardiomyopathy and heart failure. The two major types of cardiac amyloidosis are cardiac amyloid light-chain (AL) and transthyretin-related cardiac amyloidosis (ATTR, mutant and wild types) (Nat Rev Cardiol 2010;7:398-408). While early recognition of cardiac amyloidosis is of major clinical importance, so is the ability to differentiate between subtypes. Indeed, both prognosis and therapeutic options vary drastically depending on the subtype. While endomyocardial biopsy with immunostaining is considered the gold standard, advances in imaging provide an attractive non-invasive alternative. Currently, electrocardiography, echocardiography, and cardiac magnetic resonance imaging are all used in the evaluation of cardiac amyloidosis with varying diagnostic and prognostic accuracy. Yet, none of these modalities can effectively differentiate the cardiac amyloid subtypes. Recent data with ^99mTc-phosphate derivatives, previously used as bone seeking radioactive tracers, have shown promising results; these radiotracers selectively bind ATTR, but not AL subtype, and can differentiate subtypes with high diagnostic accuracy. This review will initially present the non-radionuclide imaging techniques and then focus on the radionuclide imaging techniques, particularly ^99mTc-DPD and ^99mTc-PYP, mechanism of action, performance and interpretation of the study, diagnostic accuracy, prognostic value, future clinical perspective, and outlook.     

Multimodality cardiac imaging in the 21st century: evolution,advances and future opportunities for innovation

Cardiovascular imaging has significantly evolved since the turn of the century. Progress in the last two decades has been marked by advances in every modality used to image the heart, including echocardiography, cardiac magnetic resonance, cardiac CT and nuclear cardiology. There has also been a dramatic increase in hybrid and fusion modalities that leverage the unique capabilities of two imaging techniques simultaneously, as well as the incorporation of artificial intelligence and machine learning into the clinical workflow. These advances in non-invasive cardiac imaging have guided patient management and improved clinical outcomes. The technological developments of the past 20 years have also given rise to new imaging subspecialities and increased the demand for dedicated cardiac imagers who are cross-trained in multiple modalities. This state-of-the-art review summarizes the evolution of multimodality cardiac imaging in the 21st century and highlights opportunities for future innovation.     

The expanding role of left ventricular functional assessment using gated myocardial perfusion SPECT: the supporting actor is stealing the scene

Background Gating of single-photon emission computed tomography (SPECT) has significantly improved the reliability and diagnostic accuracy of myocardial perfusion imaging. The functional parameters derived from this technique, mainly left ventricular volumes and ejection fraction, have been demonstrated to be accurate and reproducible. They are able to increase the detection of severe and extensive coronary artery disease and show a significant incremental prognostic power over perfusion abnormalities. Therefore, the importance given to gated SPECT functional data has progressively grown. Discussion This circumstance has further expanded the indications for myocardial perfusion imaging and strengthened its position among the different imaging modalities. Moreover, several studies show that the evaluation of ventricular function may have a leading part in justifying the execution of perfusion scintigraphy in various clinical conditions. Aim Aim of this review is to describe this evolution of gated SPECT functional assessment from a supporting rank with respect to perfusion, to a main actor position in the field of cardiac imaging.     

Clinical use of cardiac PET/MRI: current state-of-the-art and potential future applications

Combined PET/MRI is a novel imaging method integrating the advances of functional and morphological MR imaging with PET applications that include assessment of myocardial viability, perfusion, metabolism of inflammatory tissue and tumors, as well as amyloid deposition imaging. As such, PET/MRI is a promising tool to detect and characterize ischemic and non-ischemic cardiomyopathies. To date, the greatest benefit may be expected for diagnostic evaluation of systemic diseases and cardiac masses that remain unclear in cardiac MRI, as well as for clinical and scientific studies in the setting of ischemic cardiomyopathies. Diagnosis and therapeutic monitoring of cardiac sarcoidosis has the potential of a possible ‘killer-application’ for combined cardiac PET/MRI. In this article, we review the current evidence and discuss current and potential future applications of cardiac PET/MRI.     

Late enhancement on cardiac computed tomography in a patient with cardiac sarcoidosis

Cardiac computed tomography (CT) angiography permits detection of myocardial scars through “late enhancement.” We report the case of a patient with suspected cardiac sarcoidosis. Because of implanted defibrillator leads, magnetic resonance imaging was not possible. Dual-source CT with intravenous contrast injection was used as an alternative technique to detect late myocardial enhancement. A typical pattern of myocardial scarring allowed us to establish the diagnosis of cardiac sarcoidosis. CT imaging may be an alternative diagnostic tool to visualize late enhancement in patients with contraindications to magnetic resonance imaging.