Virtual birefringence imaging and histological staining of amyloid deposits in label-free tissue using autofluorescence microscopy and deep learning.

Systemic amyloidosis involves the deposition of misfolded proteins in organs/tissues, leading to progressive organ dysfunction and failure. Congo red is the gold-standard chemical stain for visualizing amyloid deposits in tissue, showing birefringence under polarization microscopy. However, Congo red staining is tedious and costly to perform, and prone to false diagnoses due to variations in amyloid amount, staining quality and manual examination of tissue under a polarization microscope. We report virtual birefringence imaging and virtual Congo red staining of label-free human tissue to show that a single neural network can transform autofluorescence images of label-free tissue into brightfield and polarized microscopy images, matching their histochemically stained versions. Blind testing with quantitative metrics and pathologist evaluations on cardiac tissue showed that our virtually stained polarization and brightfield images highlight amyloid patterns in a consistent manner, mitigating challenges due to variations in chemical staining quality and manual imaging processes in the clinical workflow.

Detecting Amyloid Goiter With 99mTc-PYP SPECT/CT in the Setting of Ankylosing Spondylitis: An Uncommon Involvement of AA Amyloidosis.

ABSTRACT: We present a case with systemic amyloidosis secondary to ankylosing spondylitis (AA amyloidosis), whose 99mTc PYP scintigraphy revealed amyloid deposition in the thyroid gland (amyloid goiter). Amyloidosis is characterized by extracellular accumulation of amyloid fibril proteins leading to organ malfunction. Even though AA amyloidosis can be observed in patients with systemic inflammatory diseases, it is a very rare complication in ankylosing spondylitis. SPECT/CT images showed diffuse tracer uptake in enlarged thyroid gland containing fat density areas.

Ongoing assertion of two-dimensional measurements on differentiation type of left ventricular hypertrophy: Focus on inferior vena cava.

BACKGROUND: Left ventricular hypertrophy (LVH), including hypertensive LVH, hypertrophic cardiomyopathy (HCM) and cardiac amyloidosis (CA), is a commonly encountered condition in cardiology practice, presenting challenges in differential diagnosis. In this study, we aimed to investigate the importance of echocardiographic evaluation of the inferior vena cava (IVC) in distinguishing LVH subtypes including hypertensive LVH, HCM, and CA. METHODS: In this retrospective study, patients with common causes of LVH including hypertensive LVH, HCM, and CA were included. The role of echocardiographic evaluation of IVC diameter and collapsibility in distinguishing these causes of LVH was assessed in conjunction with other echocardiographic, clinical, and imaging methods. RESULTS: A total of 211 patients (45% HCM, 43% hypertensive heart disease, and 12% CA) were included in our study. Their mean age was 56.6 years and 62% of them were male. While mean IVC diameter was significantly dilated in CA patients (13.4 mm in hypertensive LVH, 16.0 mm in HCM, and 21.1 mm in CA, p < .001), its collapsibility was reduced (IVC collapsible in 95% of hypertensive patients, 72% of HCM patients, and 12% of CA patients, p < .001). In the analysis of diagnostic probabilities, the presence of both hypovoltage and IVC dilation is significant for CA patients. Although it is not statistically significant, the presence of IVC dilation along with atrial fibrillation supports the diagnosis of HCM. CONCLUSION: In conclusion, although advances in imaging techniques facilitate the diagnosis of LVH, simple echocardiographic methods should never be overlooked. Our study supports the notion that IVC assessment could play an important role in the differential diagnosis of LVH.

A case of hypopharyngeal amyloidosis by digestive endoscopy. / æ¶ˆåŒ–å† é•œæ£€æŸ¥å‘çŽ°ä¸‹å’½éƒ¨æ·€ç²‰æ ·å˜æ€§1例.

Amyloidosis is a rare disease. This paper reports a case of localized secondary hypopharyngeal amyloidosis presenting with pulmonary tuberculosis as the initial symptom. The patient lacked specific clinical manifestations and primarily exhibited symptoms such as cough, sputum production, acid reflux, belching, and abdominal pain. Chest CT indicated bronchiectasis with infection and pulmonary tuberculosis. Digestive endoscopy revealed a white mucosal elevation at the right pyriform sinus of the hypopharynx. Pathological diagnosis confirmed amyloid deposits in the hypopharyngeal mucosal tissue. The patient tested positive for anti-amyloid A antibodies, Congo red staining (+), and periodate Schiff staining (+). Amyloidosis commonly affects the digestive system and may have various etiologies, often presenting with symptoms that overlap with other digestive system diseases, leading to frequent misdiagnosis and missed optimal treatment opportunities. The hypopharynx, a highly folded and narrow chamber that serves as a common passage for the digestive and respiratory tracts, can be effectively evaluated for amyloidosis using digestive endoscopy.

[Pulmonary Amyloidosis Observed by Thoracoscopy:Report of a Case].

The case is an 80-year-old woman with Sjögren's syndrome. During the follow-up of multiple pulmonary nodules, an enlarged nodule was observed in the peripheral of the right S3 interlobar region. Fluorodeoxyglucose- positron emission tomography (FDG-PET) showed FDG accumulation only in the S3 nodule, which led to suspicion of primary lung cancer. Because of its difficult location to reach by bronchoscopy, a right lung S3 segmentectomy was performed. Intraoperative findings revealed a hard yellowish- white nodule just below the pleura. Pathological examination showed that the nodule consisted of an acidophilic structureless material, which was positive for Congo red staining and disappeared after permanganate treatment. Based on the above findings, we diagnosed amyloid A( AA)-type amyloidosis. In this case, the nodule was located just below the pleura and we could observe it by thoracoscopy. There have been few reports of thoracoscopic observation of pulmonary amyloidosis, and we report with intraoperative findings.

Advancements and challenges in cardiac amyloidosis imaging: A comprehensive review of novel techniques and clinical applications.

Cardiac amyloidosis, characterized by amyloid fibril deposition in the myocardium, leads to restrictive cardiomyopathy and heart failure. This review explores recent advancements in imaging techniques for diagnosing and managing cardiac amyloidosis, highlighting their clinical applications, strengths, and limitations. Echocardiography remains a primary, non-invasive imaging modality but lacks specificity. Cardiac MRI (CMR), with Late Gadolinium Enhancement (LGE) and T1 mapping, offers superior tissue characterization, though at higher costs and limited availability. Scintigraphy with Tc-99m-PYP reliably diagnoses transthyretin (TTR) amyloidosis but is less effective for light chain (AL) amyloidosis, necessitating complementary diagnostics. Amyloid-specific PET tracers, such as florbetapir and flutemetamol, provide precise imaging and quantitative assessment for both TTR and AL amyloidosis. Challenges include differentiating between TTR and AL amyloidosis, early disease detection, and standardizing imaging protocols. Future research should focus on developing novel tracers, integrating multimodality imaging, and leveraging AI to enhance diagnostic accuracy and personalized treatment. Advancements in imaging have improved cardiac amyloidosis management. A multimodal approach, incorporating echocardiography, CMR, scintigraphy, and PET tracers, offers comprehensive assessment. Continued innovation in tracers and AI applications promises further enhancements in diagnosis, early detection, and patient outcomes.

Molecular basis for non-invasive diagnostics of cardiac amyloids using bone tracers.

Amyloid diseases including Alzheimer's, Parkinson's and over 30 others are incurable life-threatening disorders caused by abnormal protein deposition as fibrils in various organs. Cardiac amyloidosis is particularly challenging to diagnose and treat. Identification of the fibril-forming protein, which in the heart is usually amyloid transthyretin (ATTR) or amyloid immunoglobulin light chain (AL), is paramount to treatment. A transformative non-invasive diagnostic modality is imaging using technetium-labeled pyrophosphate or diphosphonate bone tracers, 99mTc-PYP/DPD/HMDP. For unknown reasons, these tracers show preferential uptake by ATTR deposits. The tracer-binding moiety is unknown and potentially involves amyloid fibrils and/or amyloid-associated calcific deposits. We propose that, like in the bone, the tracers chelate to surface-bound Ca2+ in amyloid. In high-affinity protein sites, Ca2+ is coordinated by pairs of acidic residues. To identify such residues on amyloids, we harnessed atomic structures of patient-derived cardiac amyloids determined using cryogenic electron microscopy since 2019. These structures help explain why most but not all ATTR deposits uptake 99mTc-PYP/DPD/HMDP radiotracers, while in AL the opposite is true. Moreover, fibril structures help explain greater microcalcification observed in ATTR vs. AL deposits. These findings may aid the diagnostics and therapeutic targeting of cardiac amyloidosis and are relevant to other amyloids.

Radionuclide Imaging of Cardiac Amyloidosis: An Update and Future Aspects.

Cardiac amyloidosis (CA) is caused by the misfolding, accumulation and aggregation of proteins into large fibrils in the extracellular compartment of the myocardium, leading to restrictive cardiomyopathy, heart failure and death. The major forms are transthyretin (ATTR) CA and light-chain (AL) CA, based on the respective precursor protein. Each of them requires early diagnosis for a timely treatment initiation that will improve patient outcomes. For this, radionuclide imaging is essentially used as single-photon emission computed tomography (SPECT) with bone-avid radiotracers or as positron emission tomography (PET) with amyloid-binding radiotracers. Both offer unprecedented specificity for the diagnostic of CA. SPECT has even revolutionized the diagnosis of ATTR-CA by making it non-invasive. Indeed, SPECT has now entered the standard diagnostic pathway to CA and has led to earlier diagnosis of the disease. SPECT also modified the epidemiology of ATTR-CA, highlighting that the disease is much more frequent than previously believed, and showing that ATTR-CA plays a substantial role in HFpEF and aortic stenosis, particularly among elderly patients. In parallel, amyloid-binding radiotracers for PET have accumulated a substantial amount of evidence, but are not approved for clinical use in CA yet. Further studies are needed to refine acquisition protocols and validate results in broader populations. Unlike bone-avid SPECT radiotracers, PET radiotracers have been specifically created to bind to amyloid fibrils. Thus, PET is the only imaging method that is truly specific for amyloid deposits and very sensitive to any amyloid type. Indeed, PET can not only detect ATTR-CA, but also AL-CA and rare hereditary forms. For both SPECT and PET, advances in quantitation of myocardial uptake have generated more granular and reproducible findings, paving the way for progress in earlier diagnosis, risk stratification and therapeutic response monitoring. Encouraging findings have shown that SPECT and PET are sensitive to early CA when other diagnostic methods are negative. Both radionuclide imaging techniques can predict adverse outcomes, but more evidence is needed to determine how to use them in conjunction with usual prognostic staging scores. Studies on follow-up imaging after therapy suggested that SPECT and PET can capture myocardial changes in CA, but again, more data are needed to meaningfully interpret such changes. Based on all these promising results, radionuclide imaging has the potential to further impact the landscape of CA in diagnosis, prognosis and follow-up, but also to substantially contribute to the assessment of novel therapies that will improve the lives of patients with CA.

The value of myocardial contraction fraction and long-axis strain to predict late gadolinium enhancement in multiple myeloma patients with secondary cardiac amyloidosis.

The aim of this study is to assess the effectiveness of conventional and two additional functional markers derived from standard cardiac magnetic resonance (CMR) images in detecting the occurrence of late gadolinium enhancement (LGE) in patients with secondary cardiac amyloidosis (CA) related to multiple myeloma (MM). This study retrospectively included 32 patients with preserved ejection fraction (EF) who had MM-CA diagnosed consecutively. Conventional left ventricular (LV) function markers and two additional functional markers, namely myocardial contraction fraction (MCF) and LV long-axis strain (LAS), were obtained using commercial cardiac post-processing software. Logistic regression analyses and receiver operating characteristic (ROC) analysis were performed to evaluate the predictive performances. (1) There were no notable distinctions in clinical features between the LGE+ and LGE- groups, with the exception of a reduced systolic blood pressure in the former (105.60 ± 18.85 mmHg vs. 124.50 ± 20.95 mmHg, P = 0.022). (2) Patients with MM-CA presented with intractable heart failure with preserved ejection fraction (HFpEF). The LVEF in the LGE+ group exhibited a greater reduction (54.27%, IQR 51.59-58.39%) in comparison to the LGE- group (P < 0.05). And MM-CA patients with LGE+ had significantly higher LVMI (90.15 ± 23.69 g/m2), lower MCF (47.39%, IQR 34.28-54.90%), and the LV LAS were more severely damaged (- 9.94 ± 3.42%) than patients with LGE- (all P values < 0.05). (3) The study found that MCF exhibited a significant independent association with LGE, as indicated by an odds ratio of 0.89 (P < 0.05). The cut-off value for MCF was determined to be 64.25% with a 95% confidence interval ranging from 0.758 to 0.983. The sensitivity and specificity of this association were calculated to be 95% and 83%, respectively. MCF is a simple reproducible predict marker of LGE in MM-CA patients. It is a potentially CMR-based method that promise to reduce scan times and costs, and boost the accessibility of CMR.

Cardiac magnetic resonance findings in cardiac amyloidosis.

PURPOSE OF REVIEW: The purpose of this review is to highlight the increasing importance of cardiac magnetic resonance (CMR) imaging in diagnosing and managing cardiac amyloidosis, especially given the recent advancements in treatment options. RECENT FINDINGS: This review emphasizes the crucial role of late gadolinium enhancement (LGE) with phase-sensitive inversion recovery (PSIR) techniques in both diagnosing and predicting patient outcomes in cardiac amyloidosis. The review also explores promising new techniques for diagnosing early-stage disease, such as native T1 mapping and ECV quantification. Additionally, it delves into experimental techniques like diffusion tensor imaging, MR elastography, and spectroscopy. SUMMARY: This review underscores CMR as a powerful tool for diagnosing cardiac amyloidosis, assessing risk factors, and monitoring treatment response. While LGE imaging remains the current best practice for diagnosis, emerging techniques such as T1 mapping and ECV quantification offer promise for improved detection, particularly in early stages of the disease. This has significant implications for patient management as newer therapeutic options become available for cardiac amyloidosis.

Nuclear imaging techniques for cardiac amyloidosis.

PURPOSE OF REVIEW: Cardiac amyloidosis is a condition marked by the misfolding of precursor proteins into insoluble amyloid fibrils, leading to restrictive cardiomyopathy and heart failure symptoms. This review discusses advancements in nuclear imaging techniques that enhance the diagnosis and guide the management of cardiac amyloidosis, addressing the critical need for early and accurate detection in clinical practice. RECENT FINDINGS: Recent studies and guidelines emphasizes the pivotal role of nuclear imaging techniques in diagnosing cardiac amyloidosis. Cardiac scintigraphy, using bone-avid tracers like 99mTc-PYP, 99mTc-DPD, and 99mTc-HMDP, is instrumental in distinguishing between transthyretin amyloidosis and light chain amyloidosis. PET, with tracers such as 11C-Pittsburgh Compound B (11C-PiB) and 18F-Florbetapir, offers significant potential in measuring amyloid burden and monitoring disease progression, providing detailed insights into the myocardial involvement. SUMMARY: The advancements in nuclear imaging techniques significantly impact the management of cardiac amyloidosis. These methods allow for a more accurate diagnosis, detailed assessment of disease extent, and better differentiation between amyloidosis types, which are crucial for tailoring treatment approaches. The integration of these techniques into clinical practice is essential for improving patient outcomes and advancing research in cardiac amyloidosis.

Retinal peri-arteriolar versus peri-venular amyloidosis, hippocampal atrophy, and cognitive impairment: exploratory trial.

The relationship between amyloidosis and vasculature in cognitive impairment and Alzheimer's disease (AD) pathogenesis is increasingly acknowledged. We conducted a quantitative and topographic assessment of retinal perivascular amyloid plaque (AP) distribution in individuals with both normal and impaired cognition. Using a retrospective dataset of scanning laser ophthalmoscopy fluorescence images from twenty-eight subjects with varying cognitive states, we developed a novel image processing method to examine retinal peri-arteriolar and peri-venular curcumin-positive AP burden. We further correlated retinal perivascular amyloidosis with neuroimaging measures and neurocognitive scores. Our study unveiled that peri-arteriolar AP counts surpassed peri-venular counts throughout the entire cohort (P < 0.0001), irrespective of the primary, secondary, or tertiary vascular branch location, with a notable increase among cognitively impaired individuals. Moreover, secondary branch peri-venular AP count was elevated in the cognitively impaired (P < 0.01). Significantly, peri-venular AP count, particularly in secondary and tertiary venules, exhibited a strong correlation with clinical dementia rating, Montreal cognitive assessment score, hippocampal volume, and white matter hyperintensity count. In conclusion, our exploratory analysis detected greater peri-arteriolar versus peri-venular amyloidosis and a marked elevation of amyloid deposition in secondary branch peri-venular regions among cognitively impaired subjects. These findings underscore the potential feasibility of retinal perivascular amyloid imaging in predicting cognitive decline and AD progression. Larger longitudinal studies encompassing diverse populations and AD-biomarker confirmation are warranted to delineate the temporal-spatial dynamics of retinal perivascular amyloid deposition in cognitive impairment and the AD continuum.

The Most Predictive Red Flags for Suspecting Cardiac Amyloidosis in Patients with Heart Failure with Preserved Ejection Fraction.

OBJECTIVE: Cardiac amyloidosis (CA) is a cardiomyopathy characterized by amyloid infiltration in the myocardium. Transthyretin cardiac amyloidosis (TTR-CA), commonly presenting as heart failure with preserved ejection fraction (HFpEF), was the focus of our study, which aimed to identify red flags that heighten suspicion of CA in HFpEF patients. METHODS: We prospectively included patients diagnosed with HFpEF. All patients were assessed for TTR-CA red flag features, cardiac and extra-cardiac, as outlined in the 'Diagnosis and Treatment of Cardiac Amyloidosis: A Position Statement of the European Society of Cardiology.' Technetium-99m pyrophosphate (99mTc-PYP) cardiac scintigraphy was performed in 167 HFpEF patients suspected of having TTR-CA. Patients testing positive and negative for TTR-CA were compared based on these red flag features. RESULTS: Out of 167 HFpEF patients, 19 (11.3%) were diagnosed with TTR-CA. In the TTR-CA group, 17 (89.5%) patients were 65 years or older. The presence of three or more red flags differentiated the TTR-CA positive and negative groups (P = 0.040). Features such as low voltage and pseudo infarct patterns were more prevalent in the TTR-CA group (P < 0.001 and P < 0.048, respectively). Left ventricular global longitudinal strain (LV-GLS) was lower in the TTR-CA positive group (P < 0.001). Multivariate analysis identified four variables-older age, pseudo infarct pattern, low/decreased QRS voltage, and LV-GLS-as strong, independent predictors of TTR-CA, with significant odds ratios (ORs) of 7.8, 6.8, 16.9, and 1.2, respectively. CONCLUSION: In this study, TTR-CA etiology occurs in approximately one in every ten HFpEF patients. The presence of three or more red flags increases the likelihood of TTR-CA. Older age, pseudo infarct pattern, low/decreased QRS voltage, and reduced LV-GLS are the most significant red flags indicating TTR-CA in HFpEF patients.

The Role of Scintigraphy with Bone Radiotracers in Cardiac Amyloidosis.

Cardiac amyloidosis (CA) is caused by the myocardial deposition of misfolded proteins, either amyloid transthyretin (ATTR) or immunoglobulin light chains (AL). The paradigm of this condition has transformed, since CA is increasingly recognized as a relatively prevalent cause of heart failure. Cardiac scintigraphy with bone tracers is the unique noninvasive technique able to confirm CA without performing tissue biopsy or advanced imaging tests. A moderate-to-intense myocardial uptake (Perugini grade ≥2) associated with the absence of a monoclonal component is greater than 99% specific for ATTR-CA, while AL-CA confirmation requires tissue biopsy.

The Role of Echocardiography for the Clinical Diagnosis, Risk Stratification, and Management of Cardiac Amyloidosis.

Amyloidosis is a rare, heterogeneous group of diseases characterized by extracellular infiltration and deposition of misfolded fibrils in different organs and tissues. A timely diagnosis is important as it can improve outcome. Echocardiography has emerged as a powerful tool to prompt suspicion and refer patients to second-level evaluation to reach a definitive diagnosis. In this scenario, new echo techniques offer new insight into the cardiac amyloidosis (CA) pathophysiology and clinical course. The present review aims to describe the developments in echocardiographic assessment of patients with suspected CA and it summarizes new available echocardiographic scores able to guide a definite diagnosis.

Cardiovascular Magnetic Resonance in the Management of Cardiac Amyloidosis: Current and Future Clinical Applications.

Cardiac magnetic resonance represents the gold standard imaging technique to assess cardiac volumes, wall thickness, mass, and systolic function but also to provide noninvasive myocardial tissue characterization across almost all cardiac diseases. In patients with cardiac amyloidosis, increased wall thickness of all heart chambers, a mildly reduced ejection fraction and occasionally pleural and pericardial effusion are the characteristic morphologic anomalies. The typical pattern after contrast injection is represented by diffuse areas of late gadolinium enhancement, which can be focal and patchy in very early stages, circumferential, and subendocardial in intermediate stages or even diffuse transmural in more advanced stages.

18 F-FDG Uptake in Pancreatic AL Amyloidosis Associated With Multiple Myeloma.

ABSTRACT: A 60-year-old woman underwent whole-body contrast-enhanced CT because multiple myeloma was suspected. The contrast-enhanced CT showed pancreatic enlargement without main pancreatic duct dilatation and increased peripancreatic fat tissue. 18 F-FDG PET/CT demonstrated diffuse uptake in the enlargement of the pancreas, left and right ventricles, and vertebral column. Biopsy and bone marrow aspiration cytology revealed amyloid light-chain amyloidosis associated with multiple myeloma. Chemotherapy was performed; 18 F-FDG uptake in the pancreas then disappeared, and the pancreatic enlargement decreased. When diffuse 18 F-FDG uptake in pancreatic enlargement is observed in multiple myeloma patients, amyloid light-chain amyloidosis should be considered.

Defining echocardiographic predictors of outcome in cardiac amyloidosis by subtype.

BACKGROUND: Current echocardiographic risk factors for prognosis in cardiac amyloidosis (CA) do not distinguish between the two main subtypes: transthyretin cardiomyopathy (TTR) and immunoglobulin light chain cardiomyopathy (AL), each of which require distinct diagnostic and therapeutic approaches. Additionally, only traditional parameters have been studied with little data on advanced techniques. Accordingly, we sought to determine whether differences exist in 2D transthoracic echocardiography (2DE) predictors of survival between the CA subtypes using a comprehensive approach. METHODS: 220 patients (72±12 years) with confirmed CA (AL=89, TTR=131) who underwent 2DE at the time of CA diagnosis were enrolled. Left ventricular (LV) dimensions, indexed mass (LVMi), global longitudinal strain (LVGLS), apical-sparing ratio (LVASR), diastology, right ventricular (RV) size and function indices including tricuspid annular systolic excursion (TAPSE), RV free-wall (RVFWS) and global (RVGLS) strain, indexed left (LA) and right atrial volumes (LAVi and RAVi), LA strain (reservoir and booster) and RV systolic pressure (RVSP) were measured. A propensity-score weighted stepwise variable selection Cox proportional hazards model derived from NYHA class and renal impairment status at diagnosis was used to determine the associations between 2DE parameters and mortality specific to CA subtype over a median follow-up of 36-months. RESULTS: After adjusting for age, atrial fibrillation and treatment, parameters associated with survival were RVFWS (p=0.003, HR 1.15, 95% CI[1.053,1.245]) and RVSP (p=0.03, HR 1.03, 95% CI[1.004,1.063]) in AL and LVASR (p=0.007, HR 6.68, 95% CI[1.75,25.492]) and RAVi (p=0.049, HR 1.03, 95% CI[1.000,1.052]) in TTR. CONCLUSIONS: Echocardiographic prognosticators for survival are specific to cardiac amyloid subtype. These results potentially provide information critical for clinical decision-making and follow-up in these patients.