Tissue Characterization Research Articles

Is myocardial fibrosis appropriately assessed by 2D strain derived integrated backscatter?

Abstract Introduction Calibrated integrated backscatter (cIB) may be obtained from bidimensional (2D) strain echocardiography as a quantification measurement of myocardial ultrasound reflectivity. Increased collagen content of the myocardium modifies tissue reflectivity and cIB is suggested as a marker of left ventricular (LV) fibrosis. However, its diagnostic accuracy is not fully established. Aim To assess the correlation between cIB by 2D strain and LV myocardial fibrosis (MF), as evaluated by non-invasive imaging and histopathology. Methods Correlation study from a cohort of 157 patients with severe symptomatic aortic stenosis (AS) referred for surgical aortic valve replacement (AVR). Patients with complete preoperative transthoracic echocardiography, cardiac magnetic resonance (CMR) and endomyocardial biopsy (EMB) obtained from the anterior basal septum at the time of AVR were selected. Two groups of 30 patients were evaluated, with and without late gadolinium enhancement (LGE) at CMR. Integrated Backscatter was obtained at QRS peak in decibels (dB) from both parasternal long axis (PLAX) and apical-three-chamber (A3C) cine clips at Qanalysis. cIB was calculated by subtracting the pericardial intensity from the average of the anteroseptal and basal inferolateral wall values. Correlation analysis was performed for the whole group of patients with global and segmental (anterior basal septum) values of native T1 and extracellular volume (ECV), and EMB collagen volume fraction (CVF) from Masson´s Trichrome staining. IBS values were compared in both group of patients. Results 60 patients (74 [36-74] years, 45% male) with high gradient (mean gradient: 63±20mmHg), normal flow (45±10mL/m2), preserved ejection fraction (60±9%) AS were included. Basal septal cIB was –9.17±9.45dB and –17.45 (–31.2–10.95) dB from A3C and PLAX views, respectively. These indexes did not correlate with basal septum thickness or global LV mass. Absolute and cIB did not correlate neither with global and regional T1 and ECV values, nor with CVF at EMB. These were not significantly different in both groups of patients and there was no correlation between cIB values and mass of replacement MF in patients with LGE. Conclusion In these cohort of patients with classical severe AS, there was no correlation of cIB with imaging markers of both replacement and diffuse MF. cIB also didn´t correlate with CVF at histopathology. These findings suggest that reflectivity indexes are not suitable for myocardial tissue characterization in this setting.

The role of infliximab in treating refractory cardiac sarcoidosis

Abstract Introduction Cardiac sarcoidosis (CS) is associated with therapeutic challenges, and a high morbidity and mortality. Tumour necrosis factor alpha inhibitors like infliximab may be a treatment option for patients with persistent myocardial inflammatory activity despite conventional immunosuppressive treatment with steroids and steroid-sparing agents. Purpose To identify the safety and efficacy of infliximab in the treatment of refractory cardiac sarcoidosis. Methods We conducted a review of refractory CS patients who had been or were actively on treatment with Infliximab at our specialist tertiary care hospital from January 2017 to January 2023. Serial echocardiographic and FDG-PET scan changes as well as long term clinical data on morbidity and mortality was recorded. Results Six CS patients on infliximab were retrospectively identified. The mean age at CS diagnosis was 47.0±5.9 years and mean duration between CS diagnosis and starting infliximab was 21.4±14.2 months (Table 1). Infliximab was commenced due to persistent inflammation on FDG-PET scan and/or CMR despite being on at least two agents (prednisolone and methotrexate ± hydroxychloroquine) in 5 cases and prednisolone alone (intolerance to methotrexate) in one case. At baseline, 3 patients presented with ventricular arrhythmias, 2 with atrioventricular block and 2 with heart failure. After a mean follow up of 21.2±15.5 months of being on infliximab, 5/6 CS patients had decreased myocardial uptake on PET (1 was awaiting a scan) which included complete resolution of FDG-PET signal in one patient (Table 2). A trend in improvement of mean LVEF [52.7±6.6% to 60.2±5.9%, p = 0.10] and reduction of mean prednisolone dose [19.2±6.6mg to 11.3±7.0mg, p = 0.08] was observed during Infliximab treatment. None of the patients had worsening of LVEF or admission with acute heart failure whilst being on infliximab. A total of 4/6 patients had an Implantable Cardioverter Defibrillator device in situ at the time of Infliximab initiation. No major arrhythmias were observed during follow up. One patient died following complications of patent foramen ovale repair. There were three new cases of infection (1 pneumonia and 2 COVID-19 pneumonitis) and one case of renal cell carcinoma diagnosis three years after Infliximab treatment initiation. The drug safety was overall satisfactory since none of the patients required hospitalisation (Table 2). Case 2 patient stopped infliximab after 13 months of treatment and was found to have disease relapse seven months later. During a 20 month follow up of being on infliximab again, he demonstrated complete resolution of FDG uptake on subsequent FDG-PET scan. Conclusion This study supports the use of infliximab in refractory CS by demonstrating improvement in clinical, functional and tissue characterization parameters. However, infliximab is associated with an increased risk of infections.

Abstract 18159: Cardiac Resynchronization Therapy Response Predicted by Tissue Characterization Using Cardiac Magnetic Resonance Imaging in Non-Ischemic Dilated Cardiomyopathy

Introduction: Tissue characterization using cardiac magnetic resonance (CMR) is helpful for risk stratification in non-ischemic dilated cardiomyopathy (NIDCM). Hypothesis: This study aimed to investigate the predictive role of tissue characterization identified by CMR on cardiac resynchronization therapy (CRT) response. Methods: We retrospectively reviewed the patients who underwent CMR within 1 year before CRT implantation in NIDCM patients at a single tertiary center from January 2018 to September 2022. Late gadolinium enhancement (LGE), native T1, T2 and extracellular volume (ECV) were analyzed. CRT response was defined as a decrease in left ventricular end-systolic volume (LVESV) > 15% or an increase in left ventricular ejection fraction > 5% on TTE after at least 3 months after CRT implantation. Results: Among a total of 101 patients (mean age 66 years, 52.5% of male), 76 (75.2%) patients were defined as CRT responders. CRT responders had more LBBB (96.1% vs. 60.0%, p<0.001) and longer QRS duration (156.0±178.5 vs. 167.0±176.5ms, p=0.005) compared with CRT non-responders. However, LGE burden (34.3 vs. 13.3%, p<0.001), native T1 (1371.6 vs. 1336.8ms, p=0.033), T2 (45.9 vs. 42.1ms, p<0.001), and extracellular volume (ECV, 36.8 vs. 31.0%, p<0.001) were significantly higher in CRT non-responders. The area under the curve (AUC) to predict CRT response is the highest in LGE burden (0.817, 95% confidence interval [CI]: 0.710-0.925), followed by ECV (0.808, 95% CI: 0.711-0.905), T2 (0.779, 95% CI: 0.663-0.895), and native T1 (0.643, 95% CI: 0.520-0.766). After adjustment, LGE burden>20% (odds ratio [OR]: 0.15, 95% CI: 0.02-0.71, p=0.024) and ECV > 34% (OR: 0.13, 95% CI: 0.01-0.78, p=0.037) were independently poor CRT response predictors. Conclusions: The tissue characterization by using CMR is helpful to predict CRT response and clinical outcomes in patients with NIDCM, independently of conventional CRT response predictors.

Abstract 18453: Giant Right Atrial Lipoma Inducing Atrial Flutter and Tachycardia-Mediated Cardiomyopathy: The Value of Multimodality Cardiac Imaging

Case Presentation: A 60-year-old male who presented with progressive dyspnea on exertion and atrial flutter with rapid ventricular response. His TTE showed a large (5.1 x 3.9 cm) right atrial (RA) mass occupying 80% of a severely dilated RA attached to the lateral wall (Fig A) and severe global LV hypokinesis with an ejection fraction of 20 - 25%. A TEE was then performed to further characterize this mass and showed a large (6.3 x 5.5 x 3.7 cm), heterogeneously echoreflectant, bi-lobed, and partially mobile RA mass attached to the lateral wall (Fig B,C) just below the superior vena cava and extending near the tricuspid valve annulus with sparing of the leaflets and only mild tricuspid regurgitation. At last, a chest CT scan showed a large (5.5 x 4.5 x 3.3 cm) mass which was tissue characterized as RA lipoma (Fig D). Therefore, patient underwent an uncomplicated surgical resection of the mass with partial removal of RA free wall (Fig D,E) repaired with a pericardial patch. Pathology confirmed a RA lipoma. Patient’s atrial flutter was then ablated, and patient was discharged home in stable condition. Discussion: This case illustrates an unreported cavitary giant RA lipoma inducing atrial flutter and tachycardia-mediated cardiomyopathy and emphasizes the importance of multimodality cardiac imaging in its diagnosis and management. Cardiac lipomas are rare benign tumors usually of small size and therefore mostly incidentally detected. They can rarely lead to embolization, conduction abnormalities, and flow obstruction requiring surgical resection. In this patient, pre-operative echocardiography and CT imaging were critical in the assessment of the tumor size, tissue characterization, location, motion, relation or extension to other cardiac structures, and obstruction or dysfunction of heart valves. Pre-and-intraoperative echocardiography were also essential in planning and performing the successful surgical resection of the RA lipoma.

Abstract 15293: Impact of Catheter on Central Venous Catheter Associated Right Atrial Thrombosis in Systemic Cancer Patients

Introduction/Background: Central venous catheters (CVC) are commonly utilized in cancer patients for prolonged systemic anti-cancer treatments but increased the risk of right atrial thrombosis (C THR ). Cardiac MRI (CMR) tissue characterization is commonly performed to identify C THR based on absence of vascularity. Research Questions/Hypothesis: How do catheters affect thrombus formation? Goals/Aims: To evaluate predictors of thrombus formation in cancer patients with CVC. Methods/Approach: The population comprised of adult (≥18yo) systemic cancer pts with indwelling CVC who underwent contrast-enhanced CMR (0.2 mmol/kg gadolinium). C THR were defined using the reference of LGE-CMR via established criteria (absence of contrast enhancement). CVC depth was measured from CXR/CT. Clinical follow-up was obtained via chart review for embolic events. Results/Data (descriptive and inferential statistics): 157 cancer pts with CVC (52±17 yo; 47% M; heme 29%

Simultaneous T1, T2 and T2⁎ mapping of the liver with multi-shot MI-SAGE

PurposeTo apply multi-shot high-resolution multi inversion spin and gradient echo (MI-SAGE) acquisition for simultaneous liver T1, T2 and T2* mapping. MethodsInversion prepared spin- and gradient-echo EPI was developed with ascending slice order across measurements for efficient acquisition with T1, T2, and T2⁎ weighting. Multi-shot EPI was also implemented to minimize distortion and blurring while enabling high in-plane resolution. A dictionary-matching approach was used to fit the images to quantitative parameter maps, which were compared to T1 measured by modified Look-Locker (MOLLI), T1 measured by variable flip angle (VFA), T2 measured by multiple echo time-based Half Fourier Single-shot Turbo spin-Echo (HASTE), T2 measured by radial turbo-spin-echo (rTSE) and T2⁎ measured by multiple gradient echo (MGRE) sequences. ResultsThe multi-shot variant of the sequence achieved higher in-plane resolution of 1.7 × 1.7 mm2 with good image quality in 28 s. Derived quantitative maps showed comparable values to conventional mapping methods. As measured in phantom and in vivo, MOLLI, MESE and MGRE give closest values to MISAGE. VFA, HASTE and rTSE show obvious overestimation. ConclusionsThe proposed multi-shot inversion prepared spin- and gradient-echo EPI sequence allows for high-resolution quantitative T1, T2 and T2 liver tissue characterization in a single breath-hold scan.

Abstract 15813: Machine Learning Improves Prediction of Heart Failure and Cardiovascular Death Through a Signal Analytical Approach of Echocardiography

Introduction: Recently, speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI) have gained increasing traction as non-invasive tissue characterization methods within cardiology. But until now many patterns from the strain and TDI curves remain uninvestigated. Signal analytical methods like wavelet analysis have shown promising potential in effectively identifying previously unknown pathological patterns present in ECG signals. Therefore, we hypothesized that a signal analytic approach combined with supervised machine learning (ML) on strain and TDI curves could identify unknown pathophysiological deformation drivers of heart failure (HF) and cardiovascular death (CV death) in the general population. Methods: The analysis included 3781 subjects from the general population. In total 720 novel statistical parameters and wavelet signal parameters from 18 strain curves and 6 TDI curves were generated. The parameters were used to train an ensemble decision tree with 20-fold cross-validation and compared to a baseline ML model trained on 22 conventional echocardiographic parameters. Results: Follow up-time was four years. In total 108 subjects (2.9%) met the outcome. By including statistical and wavelet-derived parameters along with 22 conventional echocardiographic parameters in a combined model, the ML model was significantly improved compared to the baseline model (AUC for conventional model: 0.76 vs combined model: 0.825, p = 0.0086). Both statistical parameters, such as the mean and skewness of the TDI curve, as well as wavelet parameters, such as mean on the first decomposition level of the strain curve, were found to be important in the model. Conclusion Adding novel echocardiographic parameters based on signal analytical statistics and wavelet decomposition methods to preexisting conventional echocardiographic parameters significantly improved the prediction of incident HF or CV death in ML models.

CLASSICA: Validating artificial intelligence in classifying cancer in real time during surgery.

Treatment pathways for significant rectal polyps differ depending on the underlying pathology, but pre-excision profiling is imperfect. It has been demonstrated that differences in fluorescence perfusion signals following injection of indocyanine green (ICG) can be analysed mathematically and, with the assistance of artificial intelligence (AI), used to classify tumours endoscopically as benign or malignant. This study aims to validate this method of characterization across multiple clinical sites regarding its generalizability, usability and accuracy while developing clinical-grade software to enable it to become a useful method. The CLASSICA study is a prospective, unblinded multicentre European observational study aimed to validate the use of AI analysis of ICG fluorescence for intra-operative tissue characterization. Six hundred patients undergoing transanal endoscopic evaluation of significant rectal polyps and tumours will be enrolled in at least five clinical sites across the European Union over a 4-year period. Video recordings will be analysed regarding dynamic fluorescence patterns centrally as software is developed to enable analysis with automatic classification to happen locally. AI-based classification and subsequently guided intervention will be compared with the current standard of care including biopsies, final specimen pathology and patient outcomes. CLASSICA will validate the use of AI in the analysis of ICG fluorescence for the purposes of classifying significant rectal polyps and tumours endoscopically. Follow-on studies will compare AI-guided targeted biopsy or, indeed, AI characterization alone with traditional biopsy and AI-guided local excision versus traditional excision with regard to marginal clearance and recurrence.

Prognostic Utility of Cardiovascular Magnetic Resonance-Based Phenotyping in Patients With Muscular Dystrophy.

Background The prognostic utility of cardiovascular magnetic resonance imaging, including strain analysis and tissue characterization, has not been comprehensively investigated in adult patients with muscular dystrophy. Methods and Results We prospectively enrolled 148 patients with dystrophinopathies (including heterozygotes), limb-girdle muscular dystrophy, and type 1 myotonic dystrophy (median age, 36.0 [interquartile range, 23.0-50.0] years; 51 [34.5%] women) over 7.7 years in addition to an age- and sex-matched healthy control cohort (n=50). Cardiovascular magnetic resonance markers, including 3-dimensional strain and fibrosis, were assessed for their respective association with major adverse cardiac events. Our results showed that markers of contractile performance were reduced across all muscular dystrophy groups. In particular, the dystrophinopathies cohort experienced reduced left ventricular (LV) ejection fraction and high burden of replacement fibrosis. Patients with type 1 myotonic dystrophy showed a 26.8% relative reduction in LV mass with corresponding reduction in chamber volumes. Eighty-two major adverse cardiac events occurred over a median follow-up of 5.2 years. Although LV ejection fraction was significantly associated with major adverse cardiac events (adjusted hazard ratio [aHR], 3.0 [95% CI, 1.4-6.4]) after adjusting for covariates, peak 3-dimensional strain amplitude demonstrated greater predictive value (minimum principal amplitude: aHR, 5.5 [95% CI, 2.5-11.9]; maximum principal amplitude: aHR, 3.3 [95% CI, 1.6-6.8]; circumferential amplitude: aHR, 3.4 [95% CI, 1.6-7.2]; longitudinal amplitude: aHR, 3.4 [95% CI, 1.7-6.9]; and radial strain amplitude: aHR, 3.0 [95% CI, 1.4-6.1]). Minimum principal strain yielded incremental prognostic value beyond LV ejection fraction for association with major adverse cardiac events (change in χ2=13.8; P<0.001). Conclusions Cardiac dysfunction is observed across all muscular dystrophy subtypes; however, the subtypes demonstrate distinct phenotypic profiles. Myocardial deformation analysis highlights unique markers of principal strain that improve risk assessment over other strain markers, LV ejection fraction, and late gadolinium enhancement in this vulnerable patient population.

Unraveling the blue shift in porphyrin fluorescence in glioma: The 620 nm peak and its potential significance in tumor biology.

In glioma surgery, the low-density infiltration zone of tumors is difficult to detect by any means. While, for instance, 5-aminolevulinic acid (5-ALA)-induced fluorescence is a well-established surgical procedure for maximizing resection of malignant gliomas, a cell density in tumor tissue of 20-30% is needed to observe visual fluorescence. Hyperspectral imaging is a powerful technique for the optical characterization of brain tissue, which accommodates the complex spectral properties of gliomas. Thereby, knowledge about the signal source is essential to generate specific separation (unmixing) procedures for the different spectral characteristics of analytes and estimate compound abundances. It was stated that protoporphyrin IX (PpIX) fluorescence consists mainly of emission peaks at 634 nm (PpIX634) and 620 nm (PpIX620). However, other members of the substance group of porphyrins fluoresce similarly to PpIX due to their common tetrapyrrole core structure. While the PpIX634 signal has reliably been assigned to PpIX, it has not yet been analyzed if PpIX620 might result from a different porphyrin rather than being a second photo state of PpIX. We thus reviewed more than 200,000 spectra from various tumors measured in almost 600 biopsies of 130 patients. Insufficient consideration of autofluorescence led to artificial inflation of the PpIX620 peak in the past. Recently, five basis spectra (PpIX634, PpIX620, flavin, lipofuscin, and NADH) were described and incorporated into the analysis algorithm, which allowed more accurate unmixing of spectral abundances. We used the improved algorithm to investigate the PpIX620 signal more precisely and investigated coproporphyrin III (CpIII) fluorescence phantoms for spectral unmixing. Our findings show that the PpIX634 peak was the primary source of the 5-ALA-induced fluorescence. CpIII had a similar spectral characteristic to PpIX620. The supplementation of 5-ALA may trigger the increased production of porphyrins other than PpIX within the heme biosynthesis pathway, including that of CpIII. It is essential to correctly separate autofluorescence from the main PpIX634 peak to analyze the fluorescence signal. This article highlights the need for a comprehensive understanding of the spectral complexity in gliomas and suggests less significance of the 620 nm fluorescence peak for PpIX analysis and visualization.

Multislice computerized tomography coronary angiography can be a comparable tool to intravascular ultrasound in evaluating "true" coronary artery bifurcations.

Coronary bifurcation atherosclerosis depends on its angles, flow, and extensive branching. We investigate the ability of CT coronary angiography (CTCA) to determine atherosclerotic plaque characteristics of "true" bifurcation compared with intravascular ultrasound (IVUS) and the influence on side branch (SB) fate after percutaneous coronary intervention (PCI). The study included 70 patients with 72 "true" bifurcations. Most of the bifurcations were in the left anterior descending-diagonal (Dg) territory [50 out of 72 (69.4%)]. Longitudinal plaque evaluation at the polygon of confluence [carina and 5 mm proximal and distal in the main branch (MB)] showed that carina side MB and SB plaque had occurred with the lowest incidence with fibro-lipid structure (115 ± 63 HU and 89 ± 73 HU, p < 0.001 for all). Bland-Altman analysis showed a discrepancy in measuring mainly the lumen area between CTCA and IVUS in proximal MB [lumen 5.10, 95% CI (95% confidence interval, 4.53-5.68) mm2, p < 0.001; vessel -1.42, 95% CI (-2.63 to -0.21) mm2, p = 0.023], carina MB [lumen 3.74, 95% CI (3.37-4.10) mm2, p < 0.001; vessel -0.48, 95% CI (-1.45 to 0.48) mm2, p = 0.322], and distal MB [lumen 4.72, 95% CI (4.27-5.18) mm2, p < 0.001; vessel 0.62, 95% CI (-0.53 to 1.77) mm2, p = 0.283]. A significant correlation existed between average plaque density on CTCA with a percentage of calcified plaque on IVUS tissue characterization (proximal r = 0.307/p = 0.024, carina 0.469/0.008, distal 0.339/0.024, minimal lumen diameter 0.318/0.020). Circumferential plaque in the proximal MB segment remained an independent predictor of SB compromise [OR 3.962 (95% CI 1.170-13.418)]. Detection and characterization of atherosclerotic plaque by CTCA in non-left main "true" coronary bifurcations can provide useful information about bifurcation anatomy and plaque distribution that can predict outcomes after provisional stenting, thus guiding the interventional strategy to bifurcation PCI.

Unveiling the power of imaging techniques: comparing high-resolution ultrasound and functional MR neurography in peripheral nervous system pathology: a short communication

MRI and ultrasonography are used for diagnosing and helping manage peripheral nervous system pathologies. Multiple studies have compared the diagnostic accuracy of these two modalities, but the results can vary depending on the specific conditions being evaluated. In general, high-resolution ultrasound is considered a reliable and accurate tool for evaluating peripheral nerves, with high sensitivity and specificity. High-resolution ultrasound and functional MR neurography are both noninvasive imaging techniques used to evaluate nerve structures in the body. However, they differ in several technical aspects like imaging modality, spatial resolution, field of view, image quality, and accessibility. Establishing consensus on image acquisition techniques, and reporting formats to facilitate effective communication and comparison of results will further enhance the outcomes. The use of advanced ultrasound techniques, such as contrast-enhanced ultrasound, elastography, and ultrasound biomicroscopy, should be promoted for better visualization and characterization of nervous tissues, like transcranial Doppler for cerebrovascular evaluation.

Mass Spectrometry-Based Proteomic Technology and Its Application to Study Skeletal Muscle Cell Biology.

Voluntary striated muscles are characterized by a highly complex and dynamic proteome that efficiently adapts to changed physiological demands or alters considerably during pathophysiological dysfunction. The skeletal muscle proteome has been extensively studied in relation to myogenesis, fiber type specification, muscle transitions, the effects of physical exercise, disuse atrophy, neuromuscular disorders, muscle co-morbidities and sarcopenia of old age. Since muscle tissue accounts for approximately 40% of body mass in humans, alterations in the skeletal muscle proteome have considerable influence on whole-body physiology. This review outlines the main bioanalytical avenues taken in the proteomic characterization of skeletal muscle tissues, including top-down proteomics focusing on the characterization of intact proteoforms and their post-translational modifications, bottom-up proteomics, which is a peptide-centric method concerned with the large-scale detection of proteins in complex mixtures, and subproteomics that examines the protein composition of distinct subcellular fractions. Mass spectrometric studies over the last two decades have decisively improved our general cell biological understanding of protein diversity and the heterogeneous composition of individual myofibers in skeletal muscles. This detailed proteomic knowledge can now be integrated with findings from other omics-type methodologies to establish a systems biological view of skeletal muscle function.

Left ventricular fibrosis and CMR tissue characterization of papillary muscles in mitral valve prolapse patients.

Mitral valve prolapse (MVP) is associated with left ventricle (LV) fibrosis, including the papillary muscles (PM), which is in turn linked to malignant arrhythmias. This study aims to evaluate comprehensive tissue characterization of the PM by cardiovascular magnetic resonance (CMR) imaging and its association with LV fibrosis observed by intraoperative biopsies. MVP patients with indication for surgery due to severe mitral regurgitation (n = 19) underwent a preoperative CMR with characterization of the PM: dark-appearance on cine, T1 mapping, conventional bright blood (BB) and dark blood (DB) late gadolinium enhancement (LGE). CMR T1 mapping was performed on 21 healthy volunteers as controls. LV inferobasal myocardial biopsies were obtained in MVP patients and compared to CMR findings. MVP patients (54 ± 10 years old, 14 male) had a dark-appearance of the PM with higher native T1 and extracellular volume (ECV) values compared with healthy volunteers (1096 ± 78ms vs. 994 ± 54ms and 33.9 ± 5.6% vs. 25.9 ± 3.1%, respectively, p < 0.001). Seventeen MVP patients (89.5%) had fibrosis by biopsy. BB-LGE + in LV and PM was identified in 5 (26.3%) patients, while DB-LGE + was observed in LV in 9 (47.4%) and in PM in 15 (78.9%) patients. DB-LGE + in PM was the only technique that showed no difference with detection of LV fibrosis by biopsy. Posteromedial PM was more frequently affected than the anterolateral (73.7% vs. 36.8%, p = 0.039) and correlated with biopsy-proven LV fibrosis (Rho 0.529, p = 0.029). CMR imaging in MVP patients referred for surgery shows a dark-appearance of the PM with higher T1 and ECV values compared with healthy volunteers. The presence of a positive DB-LGE at the posteromedial PM by CMR may serve as a better predictor of biopsy-proven LV inferobasal fibrosis than conventional CMR techniques.

Value of cardiac magnetic resonance on the risk stratification of cardiomyopathies.

Cardiomyopathies represent a diverse group of heart muscle diseases with varying etiologies, presenting a diagnostic challenge due to their heterogeneous manifestations. Regular evaluation using cardiac imaging techniques is imperative as symptoms can evolve over time. These imaging approaches are pivotal for accurate diagnosis, treatment planning, and optimizing prognostic outcomes. Among these, cardiovascular magnetic resonance (CMR) stands out for its ability to provide precise anatomical and functional assessments. This manuscript explores the significant contributions of CMR in the diagnosis and management of patients with cardiomyopathies, with special attention to risk stratification. CMR's high spatial resolution and tissue characterization capabilities enable early detection and differentiation of various cardiomyopathy subtypes. Additionally, it offers valuable insights into myocardial fibrosis, tissue viability, and left ventricular function, crucial parameters for risk stratification and predicting adverse cardiac events. By integrating CMR into clinical practice, clinicians can tailor patient-specific treatment plans, implement timely interventions, and optimize long-term prognosis. The non-invasive nature of CMR reduces the need for invasive procedures, minimizing patient discomfort. This review highlights the vital role of CMR in monitoring disease progression, guiding treatment decisions, and identifying potential complications in patients with cardiomyopathies. The utilization of CMR has significantly advanced our understanding and management of these complex cardiac conditions, leading to improved patient outcomes and a more personalized approach to care.

Application of thermal analysis methods in biology and medicine

Thermal analysis methods are widely used in the characterization of substances and materials in chemistry and engineering. But they also find their application in life sciences: biology and medicine. This paper exhaustively and critically reviews the application of the most commonly used thermal analysis methods for the characterization of organs and tissues of plants, animals, and humans. The methods are suitable for differentiating between several types of water in a cell, optimizing treatment, storage, or cultivation conditions, following plant or animal development, medical diagnostics and modelling, and more. Expertise developed in the characterization of synthetic materials and molecules can be transferred to that of biological tissues and biomolecules and opens a perspective for interdisciplinary research. Still, researchers should take into consideration the inherent complexity of biological samples, as well as inevitable changes when isolating the tissue from the living organism.

Rapid estimation of electroporation-dependent tissue properties in canine lung tumors using a deep neural network

The efficiency of electroporation treatments depends on the application of a critical electric field over the targeted tissue volume. Both the electric field and temperature distribution strongly depend on the tissue-specific electrical properties, which both differ between patients in healthy and malignant tissues and change in an electric field-dependent manner from the electroporation process itself. Therefore, tissue property estimations are paramount for treatment planning with electroporation therapies. Ex vivo methods to find electrical tissue properties often misrepresent the targeted tissue, especially when translating results to tumors. A voltage ramp is an in situ method that applies a series of increasing electric potentials across treatment electrodes and measures the resulting current. Here, we develop a robust deep neural network, trained on finite element model simulations, to directly predict tissue properties from a measured voltage ramp. There was minimal test error (R2>0.94;p<0.0001) in three important electric tissue properties. Further, our model was validated to correctly predict the complete dynamic conductivity curve in a previously characterized ex vivo liver model (R2>0.93;p<0.0001) within 100 s from probe insertion, showing great utility for a clinical application. Lastly, we characterize the first reported electrical tissue properties of lung tumors from five canine patients (R2>0.99;p<0.0001). We believe this platform can be incorporated prior to treatment to quickly ascertain patient-specific tissue properties required for electroporation treatment planning models or real-time treatment prediction algorithms. Further, this method can be used over traditional ex vivo methods for in situ tissue characterization with clinically relevant geometries.

Approach to imaging modalities in the setting of suspected infection.

Imaging plays an important role in the workup of musculoskeletal infection, in conjunction with clinical history and physical exam. There are multiple imaging modalities that can be of clinical utility in the setting of suspected infection, each with their own benefits and limitations. Radiography is a low-cost, accessible modality providing a broad osseous overview, but can be insensitive for early osteomyelitis. Ultrasound plays a more limited role in the workup of musculoskeletal infection, but can be useful in the pediatric population or for real-time guidance for joint and soft tissue aspirations. Computed tomography (CT) plays an important role in the timely and accurate diagnosis of critically ill patients in the emergency setting. Its superior soft tissue characterization allows for diagnosis of abscesses, and it can help confirm the clinical diagnosis of necrotizing fasciitis when soft tissue gas is present. Magnetic resonance imaging (MRI) is often the modality of choice in the diagnosis of infection, as its superior contrast resolution allows for clear delineation of the presence and extent of both soft tissue infection and osteomyelitis. Additionally, the use of intravenous contrast and advanced imaging sequences such as diffusion weighted imaging (DWI) further increases the diagnostic utility of MRI in the assessment for infection. Familiarity with the diagnostic utility of each imaging modality will allow the radiologist to appropriately guide imaging workup in the setting of clinically suspected infection.

An Extensive Review on Imaging Diagnosis Methods in Takotsubo Syndrome.

Takotsubo Syndrome (TS) is an acute, reversible cardiac dysfunction, with complex, not entirely understood pathophysiology and heterogeneous clinical picture. Imaging methods each have a crucial role in the diagnosis, in-hospital management, short term and long term follow up. Coronary angiography needs to be performed, especially in the setting of a suspected acute coronary syndrome, in order to rule out coronary artery disease. Echocardiography plays a central role both in the acute and the chronic phase. It is the first imaging investigation performed in patients with TS, valuable to diagnose systolic dysfunction, the wall motion pattern and early complications. Cardiac magnetic resonance tissue characterization provides an essential role in the differential diagnosis of TS with other non-ischemic causes of systolic dysfunction. This review focuses on the imaging methods and the important part they play in the complex management of the disease.

A three-dimensional Magnetic Resonance Spin Tomography in Time-domain protocol for high-resolution multiparametric quantitative magnetic resonance imaging.

Magnetic Resonance Spin TomogrAphy in Time-domain (MR-STAT) is a multiparametric quantitative MR framework, which allows for simultaneously acquiring quantitative tissue parameters such as T1, T2, and proton density from one single short scan. A typical two-dimensional (2D) MR-STAT acquisition uses a gradient-spoiled, gradient-echo sequence with a slowly varying RF flip-angle train and Cartesian readouts, and the quantitative tissue maps are reconstructed by an iterative, model-based optimization algorithm. In this work, we design a three-dimensional (3D) MR-STAT framework based on previous 2D work, in order to achieve better image signal-to-noise ratio, higher though-plane resolution, and better tissue characterization. Specifically, we design a 7-min, high-resolution 3D MR-STAT sequence, and the corresponding two-step reconstruction algorithm for the large-scale dataset. To reduce the long acquisition time, Cartesian undersampling strategies such as SENSE are adopted in our transient-state quantitative framework. To reduce the computational burden, a data-splitting scheme is designed for decoupling the 3D reconstruction problem into independent 2D reconstructions. The proposed 3D framework is validated by numerical simulations, phantom experiments, and in vivo experiments. High-quality knee quantitative maps with 0.8 × 0.8 × 1.5 mm3 resolution and bilateral lower leg maps with 1.6 mm isotropic resolution can be acquired using the proposed 7-min acquisition sequence and the 3-min-per-slice decoupled reconstruction algorithm. The proposed 3D MR-STAT framework could have wide clinical applications in the future.