Usefulness of tissue tracking to differentiate tachycardia-induced cardiomyopathy from dilated cardiomyopathy in patients admitted for heart failure.

INTRODUCTION: Differentiation of tachycardia-induced cardiomyopathy (TIC) from dilated cardiomyopathy (DCM) in patients admitted for heart failure (HF) with left ventricular dysfunction and supraventricular tachyarrhythmia (SVT) remains challenging. The role of tissue tracking (TT) in this setting remains unknown. METHODS: Forty-three consecutive patients admitted for HF due to SVT with left ventricular ejection fraction (LVEF) < 50% undergoing CMR were retrospectively included. Those eventually evolving to LVEF > 50% at follow-up were classified as TIC and those maintaining a LVEF < 50% were classified as DCM. Clinical, echocardiography, and CMR findings, including TT, were analyzed to predict LVEF recovery. RESULTS: Twenty-five (58%) patients were classified as TIC. Late gadolinium enhancement (LGE) was more frequent in DCM group (61% vs 16%, p = 0.004). Left ventricle (LV) peak systolic radial velocity and peak diastolic radial strain rate were lower in DCM group (7.24 ± 4.44 mm/s vs 10.8 ± 4.5 mm/s; p = 0.015 and -0.12 ± 0.33 1/s vs -0.48 ± 0.51 1/s; p = 0.016, respectively). Right ventricle (RV) peak circumferential displacement was lower in patients with TIC (0.2 ± 1.3 vs 1.3 ± 0.9°; p = 0.009). In the multivariate analysis, diabetes (p = 0.046), presence of LGE (p = 0.028), LV peak systolic radial velocity < 7.5 mm/s (p = 0.034), and RV peak circumferential displacement > 0.5° (p = 0.028) were independent predictors of lack of LVEF recovery. CONCLUSION: In the setting of acute HF with LV dysfunction related to SVT, diabetes, LGE, LV peak systolic velocity, and RV peak circumferential displacement are independent predictors of lack of LVEF recovery and, therefore, represent clinically useful parameters to differentiate TIC from DCM.

Late gadolinium enhancement and outcome of cardiac resynchronization therapy in non-ischemic cardiomyopathy.

BACKGROUND: It is uncertain whether CRT with defibrillator (CRTD) is superior to CRT with pacemaker (CRTP) in NICM. Patients with low arrhythmic risk and high probability of response to CRT might be ideal candidates for CRTP. We aimed to evaluate predictors of ventricular arrhythmias and of echocardiographic response to cardiac resynchronization therapy (CRT) in non-ischemic cardiomyopathy (NICM). METHODS: Multicenter, retrospective observational study of NICM patients with left ventricular ejection fraction (LVEF) ≤35 %, cardiac magnetic resonance with analysis of late gadolinium enhancement (LGE) available and de-novo CRT implant. Echocardiographic response to CRT was defined as an improvement in LVEF ≥10 %. The combined arrhythmic endpoint included sustained ventricular tachycardia, appropriate ICD therapy, resuscitated cardiac arrest and sudden death. RESULTS: We included 167 patients, with a median follow-up of 63 months. LGE was present in 77 (46 %). Response to CRT occurred in 68 % of patients, more frequently in LGE- than in LGE+ (81 % vs 53 %, p < 0.001). Absence of LGE (OR 3.4, p = 0.002), was an independent predictor of response to CRT. The arrhythmic endpoint occurred in 19 patients (11 %). Among LGE- patients there were zero arrhythmic events as compared to a 25 % cumulative incidence in LGE+ (p < 0.001). Presence of LGE (HR 22.5, p < 0.001), was an independent predictor of the arrhythmic endpoint. CONCLUSION: Absence of LGE identifies patients at minimal arrhythmic risk and with high probability of response to CRT. Thus, they might be ideal candidates to CRT-P.

Deep learning of echocardiography distinguishes between presence and absence of late gadolinium enhancement on cardiac magnetic resonance in patients with hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) can cause myocardial fibrosis, which can be a substrate for fatal ventricular arrhythmias and subsequent sudden cardiac death. Although late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) represents myocardial fibrosis and is associated with sudden cardiac death in patients with HCM, CMR is resource-intensive, can carry an economic burden, and is sometimes contraindicated. In this study for patients with HCM, we aimed to distinguish between patients with positive and negative LGE on CMR using deep learning of echocardiographic images. METHODS: In the cross-sectional study of patients with HCM, we enrolled patients who underwent both echocardiography and CMR. The outcome was positive LGE on CMR. Among the 323 samples, we randomly selected 273 samples (training set) and employed deep convolutional neural network (DCNN) of echocardiographic 5-chamber view to discriminate positive LGE on CMR. We also developed a reference model using clinical parameters with significant differences between patients with positive and negative LGE. In the remaining 50 samples (test set), we compared the area under the receiver-operating-characteristic curve (AUC) between a combined model using the reference model plus the DCNN-derived probability and the reference model. RESULTS: Among the 323 CMR studies, positive LGE was detected in 160 (50%). The reference model was constructed using the following 7 clinical parameters: family history of HCM, maximum left ventricular (LV) wall thickness, LV end-diastolic diameter, LV end-systolic volume, LV ejection fraction < 50%, left atrial diameter, and LV outflow tract pressure gradient at rest. The discriminant model combining the reference model with DCNN-derived probability significantly outperformed the reference model in the test set (AUC 0.86 [95% confidence interval 0.76-0.96] vs. 0.72 [0.57-0.86], P = 0.04). The sensitivity, specificity, positive predictive value, and negative predictive value of the combined model were 0.84, 0.76, 0.78, and 0.83, respectively. CONCLUSION: Compared to the reference model solely based on clinical parameters, our new model integrating the reference model and deep learning-based analysis of echocardiographic images demonstrated superiority in distinguishing LGE on CMR in patients with HCM. The novel deep learning-based method can be used as an assistive technology to facilitate the decision-making process of performing CMR with gadolinium enhancement.

Iodine and Gadolinium Contrast Reactions: What Is the Risk and Role of Premedication, Abbreviated Protocols, Prior History of Reactions, and Cross-Reactivity?

Immediate hypersensitivity reactions to iodinated contrast media and gadolinium-based contrast media can be life-threatening. While corticosteroid premedication or agent-switching may mitigate risk, evidence is largely indirect and based on historical studies; recent literature refutes the efficacy. Guidance on premedication varies between organizations worldwide. No strategy eliminates reactions, and indirect consequences of premedication are substantial. Accelerated regimens are often used for emergencies, but are of questionable efficacy. Identifying "high-risk" patients is complex, but a history of reactions (to the same contrast class) is the biggest risk factor.

Potpourri of Contrast Controversies and Myths: Where Is the Actual Evidence?

There are many misconceptions related to the usage of intravenous contrast agents for medical imaging. These misconceptions can affect patient care, as they can lead to nonoptimal examination usage. Knowledge of the current contrast-related misconceptions can help radiologists provide higher quality care to their patients.

Neuroimaging feature in identifying acute myelopathy etiologies: comparison between neuromyelitis optica spectrum disorder and cervical spondylotic myelopathy.

OBJECTIVE: The clinical symptoms of neuromyelitis optica spectrum disorder (NMOSD) and acute cervical spondylotic myelopathy (CSM) may overlap in some cases. This study aimed to investigate the differences in imaging features between NMOSD and CSM in acute myelopathy. METHODS: We included 78 patients in this retrospective study, including 28 NMOSD patients and 50 CSM patients. The demographic characteristics and clinical symptoms of the two groups of patients were compared. The T1 signal intensity, length of the spinal cord involved by T2 hyperintensity, degree of intervertebral disc degeneration, proportion of thoracic and lumbar cord involvement, proportion of brain involvement and lesion enhancement rate in magnetic resonance imaging (MRI) were compared between the two groups of patients. The number, length, location on the sagittal image, pattern on the sagittal image, and distribution on the axial image of the lesions in the contrast-enhanced MRI of the two groups were evaluated. RESULTS: There were differences between NMOSD and CSM patients in the proportion of women, the proportion of bowel and bladder symptoms, mRS levels, the length of the spinal cord involved by T2 hyperintensity, degree of intervertebral disc degeneration, the proportion of thoracic and lumbar cord involvement, the proportion of brain involvement, the enhancement rate and number of lesions (p < 0.05). Among NMOSD patients, linear, patchy and ring or semi-ring enhancement were present in 8(30.8%) ,14 (53.8%) and 4(15.4%)patients, respectively, and axial gray and white matter were involved in 17 (65.4%) patients. Among patients with CSM, 9(36.0%) patients showed longitudinal oriented flake, 16 (64.0%) patients showed pancake-like enhancement, and 21 (84.0%) patients showed axial white matter involvement only. The differences in enhancement pattern on sagittal images and axial involvement were statistically significant (p < 0.05). CONCLUSIONS: Early differential diagnosis of NMOSD and CSM in acute myelopathy can be made by analyzing images and the number, length, sagittal enhancement pattern, and axial involvement of gadolinium-enhanced lesions.

A five-year-old boy with anaphylaxis reaction to gadolinium-based MR contrast medium: a case report.

Magnetic resonance imaging (MRI) is one of the most widely used tests in orthopedic areas. Gadolinium-based magnetic resonance (MR) contrast media are commonly used for MRI tests. They are known to be safe with little side effects and low incidence of acute adverse reactions. Although not common, immediate hypersensitivity reaction can occur in some patients after administration of gadolinium-based MR contrast media, causing skin rash, vascular edema, dyspnea, abdominal pain, hypotension, altered mental status, cardiopulmonary arrest, and even death. During a knee joint MRI test in a 5-year-old boy, anaphylaxis, a serious symptom, occured after injecting gadolinium-based MR contrast medium. Here we report this case along with a literature review.

Distinguishing hypertensive cardiomyopathy from cardiac amyloidosis in hypertensive patients with heart failure: a CMR study with histological confirmation.

PURPOSE: Differentiation of the cause of left ventricular hypertrophy (LVH) is challenging in cases with co-existing hypertension. CMR offers assessment of diffuse myocardial abnormalities via T1 mapping with extracellular volume fraction (ECV) and macroscopic fibrosis via late gadolinium enhancement imaging (LGE). The goal of the study was to understand if CMR parameters can differentiate hypertensive cardiomyopathy (HC) from cardiac amyloidosis (CA) in patients with hypertension and heart failure, using endomyocardial biopsy (EMB) as the gold standard. METHODS: We retrospectively analyzed patients with hypertension, LVH, and heart failure undergoing EMB due to uncertain diagnosis. CMR parameters including cine, LGE characteristics, T1 mapping, and ECV were analyzed. RESULTS: A total of 34 patients were included (mean age 66.5 ± 10.7 years, 79.4% male). The final EMB-based diagnosis was HC (10, 29%), light chain (AL) CA (7, 21%), and transthyretin (ATTR) CA (17, 50%). There was a significant difference in subendocardial LGE (p = 0.03) and number of AHA segments with subendocardial LGE (p = 0.005). The subendocardial LGE pattern was most common in AL-CA (85.7%) and African American with HC (80%). ECV elevation (≥ 29%) was present in all patients with CA (AL-CA: 57.6 ± 5.2%, ATTR-CA: 59.1 ± 15.3%) and HC (37.3 ± 4.5%). CONCLUSIONS: Extensive subendocardial LGE pattern is not pathognomonic for CA but might also be present in African American patients with longstanding or poorly controlled HTN. The ECV elevation in HC with HF might be more significant than previously reported with an overlap of ECV values in HC and CA, particularly in younger African American patients.

Gadolinium-based coronary CT angiography on a clinical photon-counting-detector system: a dynamic circulating phantom study.

BACKGROUND: Coronary computed tomography angiography (CCTA) offers non-invasive diagnostics of the coronary arteries. Vessel evaluation requires the administration of intravenous contrast. The purpose of this study was to evaluate the utility of gadolinium-based contrast agent (GBCA) as an alternative to iodinated contrast for CCTA on a first-generation clinical dual-source photon-counting-detector (PCD)-CT system. METHODS: A dynamic circulating phantom containing a three-dimensional-printed model of the thoracic aorta and the coronary arteries were used to evaluate injection protocols using gadopentetate dimeglumine at 50%, 100%, 150%, and 200% of the maximum approved clinical dose (0.3 mmol/kg). Virtual monoenergetic image (VMI) reconstructions ranging from 40 keV to 100 keV with 5 keV increments were generated on a PCD-CT. Contrast-to-noise ratio (CNR) was calculated from attenuations measured in the aorta and coronary arteries and noise measured in the background tissue. Attenuation of at least 350 HU was deemed as diagnostic. RESULTS: The highest coronary attenuation (441 ± 23 HU, mean ± standard deviation) and CNR (29.5 ± 1.5) was achieved at 40 keV and at the highest GBCA dose (200%). There was a systematic decline of attenuation and CNR with higher keV reconstructions and lower GBCA doses. Only reconstructions at 40 and 45 keV at 200% and 40 keV at 150% GBCA dose demonstrated sufficient attenuation above 350 HU. CONCLUSION: Current PCD-CT protocols and settings are unsuitable for the use of GBCA for CCTA at clinically approved doses. Future advances to the PCD-CT system including a 4-threshold mode, as well as multi-material decomposition may add new opportunities for k-edge imaging of GBCA. RELEVANCE STATEMENT: Patients allergic to iodine-based contrast media and the future of multicontrast CT examinations would benefit greatly from alternative contrast media, but the utility of GBCA for coronary photon-counting-dector-CT angiography remains limited without further optimization of protocols and scanner settings. KEY POINTS: GBCA-enhanced coronary PCD-CT angiography is not feasible at clinically approved doses. GBCAs have potential applications for the visualization of larger vessels, such as the aorta, on PCD-CT angiography. Higher GBCA doses and lower keV reconstructions achieved higher attenuation values and CNR.

Alteration of cardiac structure and function and its prognostic value in patients with Takayasu arteritis: a cardiac magnetic resonance study.

Purpose: To investigate the prevalence and characteristics of late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) and its prognostic value in patients with Takayasu arteritis (TA). Materials and methods: Sixty TA patients with a CMR examination were retrospectively included. All TA patients were divided into with LGE-positive and LGE-negative groups. Bi-ventricular function and location, distribution, and pattern of left ventricular (LV) LGE were evaluated in both LGE-positive and LGE-negative groups. Primary outcome was defined as a composite of cardiovascular death, hospitalization for heart failure, coronary artery revascularization, and stroke. Univariate and multivariate Cox proportional hazard regression analyses were used to evaluate the association between variables and primary outcomes. Results: Sixty consecutive TA patients were enrolled in this study. The mean age was 38.2 ± 13.8 years and 54 patients (54/60, 90.0%) were female. LGE-positive was observed in twenty-one (21/60, 35%) patients in the total patients with TA. LGE was predominantly distributed in the middle wall and subendocardial. The patchy and infarcted LGE patterns were the most common. Compared with the LGE-negative group, the LGE-positive group had reduced LV ejection fraction (P = 0.033), elevated LV end-diastolic volume index (P = 0.008), LV end-systolic volume index (P = 0.012), and LV mass (P = 0.008). During a median follow-up period of 1,892 days (interquartile range: 1,764-1,988 days), the primary outcomes occurred in thirteen patients. In the univariate analysis, LGE-positive (hazard ratio [HR] = 4.478, 95% confidence interval [CI]: 1.376-14.570; P = 0.013) were independently associated with the primary outcomes. However, LGE-positive did not retain its value as an independent predictor of primary outcomes in the multivariate analysis. Instead, LVMI (HR = 1.030, 95%CI: 1.013-1.048; P = 0.001) was the strongest independent predictor of primary outcomes in patients with TA. The Kaplan-Meier plot revealed that patients with LVMI ≥ 57.5 g/m2 have a worse prognosis. Conclusion: LGE-positive detected by CMR was observed in 35% of total TA patients with different distributions and patterns. LGE is associated with adverse LV remodeling and worsen cardiac function. However, LVMI rather than LGE can provide independent prognostic information in patients with TA.

Cardiac MRI in Rheumatic Disease.

Immune-mediated systemic inflammatory disorders present a latent threat for cardiovascular disease. Early involvement may be associated with constitutional symptoms, while clinical evidence of disease may manifest later in an insidious manner. Multimodality imaging is crucial to detect myocardial involvement, with transthoracic echocardiogram as a first-line imaging modality; however, cardiac MRI (CMRI) has the potential to significantly impact our diagnostic and therapeutic approaches through high-fidelity chamber quantification and parametric mapping techniques. Novel imaging techniques are currently under investigation, including stress CMRI, feature tracking CMR, late gadolinium enhancement (LGE) entropy, and 4 dimensional flow CMRI.

Myocardial infarction showing non-ischaemic late gadolinium enhancement pattern in the mid-septum: a case report.

Background: Cardiac magnetic resonance (CMR) is gaining an important role in the setting of acute coronary syndromes: it gives prognostic information based on oedema and late gadolinium enhancement (LGE) extension in acute myocardial infarction, and has a diagnostic value in myocardial infarction with nonobstructive coronary arteries (MINOCA) thanks to its capability to distinguish, based on different LGE patterns, ischaemic and non-ischaemic myocardial injuries. Case summary: We describe a case of acute myocardial infarction involving a recurrent apical branch showing an atypical intramyocardial LGE pattern in the medium inferior septum. Discussion: An intramyocardial LGE pattern might be determined by an ischaemic injury involving the interventricular septum. The knowledge of this misleading LGE pattern is important to adequately interpret CMR findings in this clinical setting.

Microvascular obstruction in cardiac amyloidosis.

AIMS: Cardiac amyloidosis (CA) is characterized by deposition of amyloid fibrils within the extracellular space, causing disarray of the myocardial structure and capillary architecture. This study aims to characterize the prevalence of microvascular obstruction (MVO) in patients with CA and to assess the association between MVO and prognosis. METHODS AND RESULTS: The study population comprised 800 patients, of which 400 had light-chain CA (AL-CA) and 400 had transthyretin CA (ATTR-CA). MVO was present in 221 (27.6%) patients, and more common in ATTR-CA than AL-CA (124 [56.1%] vs. 97 [43.9%], p = 0.033). Patients with MVO had a more severe cardiac phenotype evidenced by higher N-terminal pro-brain natriuretic peptide (3516 ng/L [1944-6247] vs. 2508 ng/L [1203-5752], p < 0.001), worse global longitudinal strain (-10.5% [-12.6; -7.9] vs. -12.0% [-16.0; -8.9], p < 0.001), and higher extracellular volume (56% [51-61] vs. 50% [45-57], p < 0.001). Patients with AL-CA and MVO had a higher serum troponin (86 ng/L [47-148] vs. 59 ng/L [44-78], p < 0.001), and higher T2 (53 ms [50-56] vs. 50 ms [48-52], p < 0.001), but lower extracellular volume (55% [50-60] vs. 58% [53-61], p = 0.008) and lower indexed myocyte cell volume (48.6 g/m2 [41.1-59.8] vs. 55.7 g/m2 [47.5-68.4], p < 0.001) than patients with ATTR-CA and MVO. MVO was associated with an increased risk of mortality in the overall population (hazard ratio [HR] 1.28, 95% confidence interval [CI] 1.03-1.59, p = 0.025), and the subgroup with AL-CA (HR 1.59, 95% CI 1.17-2.17, p = 0.003) but not ATTR-CA (HR 1.04, 95% CI 0.77-1.40, p = 0.814). CONCLUSIONS: Microvascular obstruction is common in CA and is related to markers of amyloid infiltration. MVO is associated with an increased risk of mortality in AL-CA, but not in ATTR-CA. This reflects the intrinsic differences in disease biology between these two forms of CA, with MVO likely related to multiple myocardial processes, amyloid infiltration, oedema and myocyte death.

Quantitative assessment of gadolinium deposition in dentate nuclei with MR fingerprinting.

RATIONALE AND OBJECTIVES: Gadolinium deposition in the dentate nucleus (DN) has been evaluated by T1-weighted imaging (T1WI) and T1 (R1) mapping, but not MR fingerprinting (MRF). This study investigated associations between T1 and T2 values of DN and gadolinium-based contrast agents (GBCAs) using 2-dimensional MRF. MATERIALS AND METHODS: This study included 101 patients. Region of interest analysis was performed for T1 and T2 values of DN on MRF (T1-MRF, T2-MRF) and T1-weighted images (T1WI ratio). T1 and T2 ratios compared to normal cerebellar white matter (T1-MRF ratio, T2-MRF ratio) were calculated. The type of previous GBCA was confirmed in 79 patients, and linear regressions were performed between T1, T2 values and number of GBCAs. RESULTS: Good correlations were observed between T1-MRF and T1WI ratio (ρ = -0.69, P < 0.001) and between T1-MRF ratio and T1WI ratio (ρ = -0.76, P < 0.001). Mild correlations were observed between T2-MRF and T1WI ratio (ρ = -0.32, P < 0.001) and between T2-MRF ratio and T1WI ratio (ρ = -0.44, P < 0.001). The number of linear-type GBCAs was associated with T1-MRF (ß = -0.62, P < 0.001) and T1-MRF ratio (ß = -0.54, P < 0.001) in univariate linear regression analyses, and with T1-MRF (ß = -0.61, P < 0.001) and T1-MRF ratio (ß = -0.53, P < 0.001) in multivariate analysis. The number of linear-type GBCAs was associated with T2-MRF (ß = -0.30, P < 0.001) and T2-MRF ratio (ß = -0.29, P < 0.001) in univariate analyses, and with T2-MRF (ß = -0.31, P < 0.001) and T2-MRF ratio (ß = -0.32, P < 0.001) in multivariate analyses. No associations were observed between number of macrocyclic GBCAs and T1-MRF (ratio) or T2-MRF (ratio). CONCLUSION: The number of linear-type GBCA administrations was associated with lower T1 and T2 values (ratios) in DN.

The effect of iron status on gadolinium deposition in the rat brain: mechanistic implications.

Introduction: Sites associated with gadolinium (Gd) deposition in the brain (e.g., the globus pallidus) are known to contain high concentrations of ferric iron. There is considerable debate over the mechanism of Gd deposition in the brain. The role of iron transport mechanisms in Gd deposition has not been determined. Thus, we seek to identify if Gd deposition can be controlled by modifying iron exposure. Methods: Female Sprague-Dawley rats were given diets with controlled iron levels at 2-6 ppm, 6 ppt (20 g/kg Fe carbonyl) or 48 ppm for 3 weeks to induce iron deficiency, overload or normalcy. They were kept on those diets while receiving a cumulative 10 mmol/kg dose of gadodiamide intravenously over 2 weeks, then left to washout gadodiamide for 3 days or 3 weeks before tissues were harvested. Gd concentrations in tissues were analyzed by ICP-MS. Results: There were no significant effect of dietary iron and total Gd concentrations in the organs, but there was a significant effect of iron status on Gd distribution in the brain. For the 3-week washout cohort, there was a non-significant trend of increasing total brain deposition and decreasing dietary iron, and about 4-fold more Gd in the olfactory bulbs of the low iron group compared to the other groups. Significant brain accumulation was observed in the low iron group total brain Gd in the 3-week washout group relative to the 3-day washout group and no accumulation was observed in other tissues. There was a strong negative correlation between femur Gd concentrations and concentrations in other organs when stratifying by dietary iron. Discussion: Gd brain deposition from linear Gd-based contrast agents (GBCAs) are dependent upon iron status, likely through variable transferrin saturation. This iron dependence appears to be associated with redistribution of peripheral deposited Gd (e.g., in the bone) into the brain.

Relevance of increased negative T waves in apical hypertrophic cardiomyopathy with progressive myocardial damage: Insights from repeat cardiac magnetic resonance studies.

In patients with apical hypertrophic cardiomyopathy (HCM), progressive electrocardiographic changes are observed during long-term follow-up. However, it is difficult to correspond these changes to the specific myocardial changes. Cardiac magnetic resonance (CMR) imaging can elucidate myocardial changes by late gadolinium enhancement. Here, we present the long-term follow-up (>18 years) on a patient with apical HCM, whereupon, precise and continuous changes in the myocardium, causing ST segment and T wave changes on electrocardiography, were observed on CMR images. The combination of electrocardiography and CMR facilitates management of patients with apical HCM because it helps explain and understand the nature of electrocardiography changes over time.

Cardiac amyloidosis: A diagnostic challenge.

Cardiac amyloidosis is indeed a condition characterized by the deposition of amyloid proteins in the myocardium, leading to thickening and stiffening of the heart muscle. These abnormal protein deposits can interfere with the heart's normal functioning and may pose diagnostic challenges due to its varied clinical presentation and resemblance to other heart condition. Here, we present a case of 55-year-old female patient of uncontrolled hypertensions for 15 years. About 15 years ago, she presented with chest pain and was diagnosed with cardiomyopathy (CM) characterized by low left ventricle (LV) function of unknown cause. Despite being on antihypertensive treatment, the patient continued to experience chest heaviness with persistent elevate blood pressure. An echocardiogram revealed increased LV septal wall thickness, valvular thickening, and biatrial dilation. Subsequently, cardiac magnetic resonance imaging (CMR) was performed, which revealed left atrium enlargement and asymmetrical myocardial wall thickening, particularly at the septum. White blood axial image revealed thickened inter atrial septum, while late gadolinium enhancement (LGE) magnetic resonance (LGE MR) images showed patchy LGE at the base relative to the apex of the myocardium, highlighting the base-to-apex gradient, subendocardial pattern enhancement at apical lateral wall, and transmural pattern enhancement of the mid anteroseptal and inferoseptal wall. Additionally, a short axis time to invert T1 scout image of left ventricle displayed an abnormal nulling pattern initially in the myocardium, followed by the blood pool, and finally the spleen. These findings collectively led to the diagnosis of cardiac amyloidosis.

Non-invasive diagnosis of liver fibrosis via MRI using targeted gadolinium-based nanoparticles.

INTRODUCTION: Accurate diagnosis of liver fibrosis is crucial for preventing cirrhosis and liver tumors. Liver fibrosis is driven by activated hepatic stellate cells (HSCs) with elevated CD44 expression. We developed hyaluronic acid (HA)-coated gadolinium-based nanoprobes to specifically target CD44 for diagnosing liver fibrosis using T1-weighted magnetic resonance imaging (MRI). MATERIALS AND METHODS: NaGdF4 nanoparticles (NPs) were synthesized via thermal decomposition and modified with polyethylene glycol (PEG) to obtain non-targeting NaGdF4@PEG NPs. These were subsequently coated with HA to target HSCs, resulting in liver fibrosis-targeting NaGdF4@PEG@HA nanoprobes. Characterization includedd transmission electron microscopy and X-ray diffraction. Cell viability was assessed using the Cell Counting Kit-8 (CCK-8). Internalization of NaGdF4@PEG@HA nanoprobes by mouse HSCs JS1 cells via ligand-receptor interaction was observed using flow cytometry and confocal laser scanning microscopy (CLSM). Liver fibrosis was induced in C57BL/6 mice using a methionine-choline deficient (MCD) diet. MRI performance and nanoprobe distribution in fibrotic and normal livers were analyzed using a GE Discovery 3.0T MR 750 scanner. RESULTS: NaGdF4@PEG@HA nanoprobes exhibited homogeneous morphology, low toxicity, and a high T1 relaxation rate (7.645 mM⁻¹s⁻¹). CLSM and flow cytometry demonstrated effective phagocytosis of NaGdF4@PEG@HA nanoprobes by JS1 cells compared to NaGdF4@PEG. MRI scans revealed higher T1 signals in fibrotic livers compared to normal livers after injection of NaGdF4@PEG@HA. NaGdF4@PEG@HA demonstrated higher targeting ability in fibrotic mice. CONCLUSIONS: NaGdF4@PEG@HA nanoprobes effectively target HSCs with high T1 relaxation rate, facilitating efficient MRI diagnosis of liver fibrosis.

The potential of Gd doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

The study shows that the addition of gadolinium ions has a significant impact on the structure, morphology, and adsorption properties of Ni-Co spinel ferrite that was synthesized by the sol-gel auto-combustion method. The research also indicates that the higher the Gd content, the greater the increase in the lattice parameter, which suggests that Gd3+ ions uniformly replaced the octahedral Fe3+ ions. The morphology and chemical composition of Gd-doped Ni-Co ferrites have been studied using SEM and EDS. Gd adding to the NiCoFe matrix increases the BET surface area by 50% (from 48 to 72 m2/g) and promotes the formation of mesopores with an average radius from 3.9 to 4.9 nm. The pHPZC values of Gd-doped ferrites are in the range of 7.22-7.39, which means that the ferrite surface will acquire a positive charge at natural pH, so this will promote the adsorption of Congo red anionic dye through electrostatic interaction forces. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to explain the mechanism of CR adsorption on the Ni0.5Co0.5GdxFe2-xO4 adsorbent surface. The ionic-covalent parameter has been estimated to describe the surface acid-base properties. Overall, this study highlights the potential of Gd3+ doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.