S Harth

T1, T2 Mapping and Extracellular Volume Fraction (ECV): Application, Value and Further Perspectives in Myocardial Inflammation and Cardiomyopathies.

UNLABELLED Cardiac magnetic resonance imaging (CMRI) is a versatile diagnostic tool. One of its main advantages is the possibility of tissue characterization. T1-weighted images for scar and T2-weighted images for edema visualization are key methods for tissue characterization. Otherwise these sequences are strongly limited for the detection of diffuse myocardial pathologies. Recently, rapid technical innovations have generated new techniques. T1, T2 mapping and evaluation of the extracellular volume fraction (ECV) allow quantification of diffuse myocardial pathologies and showed great potential in the visualization of fibrosis, edema, amyloid, iron overload and lipid. In the future these techniques might enable the detection of early cardiac involvement, even act as a prognosticator. Moreover, therapy monitoring and follow-up might be possible due to versatile parameter quantification with these new techniques. KEY POINTS CMR allows for tissue characterization via T1- and T2-weighted sequences. In cases of diffuse, global myocardial pathologies, correct image interpretation with traditional CMR sequences might be difficult. T1, T2 mapping and ECV can quantify diffuse, global myocardial pathologies. Alterations of myocardial T1 and T2 relaxation times occur in various myocardial diseases (e.g. acute myocarditis). In the future mapping might act as a prognosticator or therapy monitoring tool.

A pilot study of the characterization of hepatic tissue strain in children with cystic-fibrosis-associated liver disease (CFLD) by acoustic radiation force impulse imaging.

BackgroundProgressive fibrotic alterations of liver tissue represent a major complication in children with cystic fibrosis. Correct assessment of cystic-fibrosis-associated liver disease (CFLD) in clinical routine is a challenging issue. Sonographic elastography based on acoustic radiation force impulse imaging (ARFI) is a new noninvasive approach for quantitatively assessing in vivo elasticity of biological tissues in many organs.ObjectiveTo characterize ARFI elastography as a diagnostic tool to assess alteration of liver tissue elasticity related to cystic fibrosis in children.Materials and methodsARFI elastography and B-mode US imaging were performed in 36 children with cystic fibrosis. The children’s clinical history and laboratory parameters were documented. According to the findings on conventional US, children were assigned to distinct groups indicating severity of hepatic tissue alterations. The relationship between US findings and respective elastography values was assessed. Additionally, differences between ARFI elastography values of each US group were statistically tested.ResultsChildren with sonomorphologic characteristics of fibrotic tissue remodeling presented significantly increased values for tissue elasticity. Children with normal B-mode US or discrete signs of hepatic tissue alterations showed a tendency toward increased tissue stiffness indicating early tissue remodeling.ConclusionAssessment of children with CFLD by means of ARFI elastography yields adequate results when compared to conventional US. For detection of early stages of liver disease with mild fibrotic reactions of hepatic tissue, ARFI elastography might offer diagnostic advantages over conventional US. Thus, liver stiffness measured by means of elastography might represent a valuable biological parameter for evaluation and follow-up of CFLD.

Development and Suggestion of a Cardiac CTA Scoring System for the Prediction of Revascularization Success in Chronic Total Occlusions (CTO) of the Coronary Arteries

OBJECTIVE Analyzing occluded segments with computed tomography angiography (CTA) prior to percutaneous coronary intervention (PCI) increased revascularization success in chronic total occlusions (CTO). The aim of our study was to develop a scoring system for the prediction of PCI success in CTO. MATERIALS AND METHODS 41 consecutive CTO patients (30 male; 63.1 years +/- 8.3 standard deviation) underwent CTA prior to PCI. All CTOs were categorized by two radiologists in consensus regarding the presence of special features and without knowledge of PCI outcome. All outcome criteria were evaluated. Afterwards one point was assigned for each unequally distributed outcome criteria per CTO and all points were added up to a single score. RESULTS Severe calcifications (failure group 68.8 % vs. success group 28.0 %; p < 0.02) and intraluminal calcifications (68.8 %; 40.0 %), tortuosity (25.0 %; 0 %; p < 0.02), linear intrathrombus enhancement (37.5 %; 60.0 %) and distal vessel disease (68.8 %; 44.0 %) were unequally distributed. By adopting a threshold of 4 points or higher (maximum 5 points), the results were: sensitivity 31.3 %, specificity 100 %, negative predictive value (NPV) 69.4 % and positive predictive value (PPV) 100 %. The PCI complication rate was 9.8 % and the mean contrast media amount was 234.4 ml. CONCLUSION With the suggested scoring system, based on five CTA criteria, PCI failure could be predicted with high PPV and specificity in our group of patients, but the NPV and sensitivity are low. However, 5 unsuccessful PCIs (13.2 %) could have been avoided and none would have been wrongly omitted. Regarding the complication rate during PCI and the high amounts of contrast media needed, a prediction system appears to be desirable and should be the object of large-scale trials. KEY POINTS Single predictors of revascularization success in CTO have been identified. Success rates are improved by analyzing CTA data sets prior to revascularization approaches. Prediction of revascularization success via a scoring system based on five CTA criteria seems promising. Patient selection for the right treatment options might be improved in the future due to application of the scoring system. Also risks, complications, contrast media amounts and radiation doses might be reduced.

Value of Cardiac T1-Mapping and ECV Quantification in Duchenne Muscular Dystrophy (DMD): Case Report, Typical Imaging Findings and Review of the Literature

Duchenne muscular dystrophy (DMD) is a X-linked recessive disorder affecting approximately 1 of 5000 males. It is the most common inherited muscular dystrophy. Key feature of the disease is a mutation in the gene for dystrophin. Absence, mutation or lack of dystrophin causes cell membrane rupture with consecutive release of creatine kinase. This results in myasthenia and muscular atrophy. Cardiac involvement with progressive global ventricular cardiac dysfunction and dilation can be present. Autopsy studies showed that cardiac pathologies in DMD contain myocyte hypertrophy but also atrophy, fibrosis and fatty and connective tissue conversions. It is also known that cardiac involvement in DMD is on its way long before symptoms develop. Cardiac disease is the leading cause of death in DMD patients in the second or third decade of life. Late gadolinium enhancement (LGE) showed promising results in detecting cardiac DMD and in prediction of adverse disease outcome. Silva et al. showed that LGE was present in 7 of 10 DMD patients and identified the lateral wall as the most commonly affected region (Silva et al. Am Coll Cardiol 2007; 49(18): 1874 – 1879), and Florian et al. showed that the transmurality of LGE predicts occurrence of adverse cardiac events (Florian et al. J Cardiovasc Magn Reson 2014; 16: 81). However, LGE imaging underlies several limitations in displaying global myocardial pathologies due to the lack of regional differences in signal intensity. It could also be shown that LGE was more likely to be detected in myocardial segments with at least 15 % collagen fiber components, whereas areas with less advanced fibrosis could not be visualized by LGE (Kim et al. J Am Coll Cardiol 2003; 41: 1568– 1572). Parametric imaging techniques, like T1mapping and extracellular volume fraction quantification (ECV), aim to overcome these problems and exhibited great potential in the early detection of different cardiac diseases. In fact, a recent study demonstrated pathologic native T1 and ECV values in DMD patients with normal heart function and absence of LGE (Soslow et al. J Cardiovasc Magn Reson 2016; 18: 5). Our case report impressively demonstrates typical imaging findings in a young male DMD patient.

Dedifferentiated Liposarcoma of the Anterior Mediastinum: A Rare Case

Liposarcoma accounts for approximately 14% of all malignant soft-tissue tumors, regardless of anatomical location (Kransdorf MJ et al. Imaging of soft tissue tumors. Philadelphia: Lippincott Williams & Wilkins, 2014). Primary mediastinal liposarcomas are rare. Liposarcoma is classified into four histologic subtypes: Myxoid/round cell, pleomorphic, atypical lipomatous tumor/ well-differentiated liposarcoma and dedifferentiated liposarcoma. Dedifferentiated liposarcoma occurs most commonly in the retroperitoneum and in the soft tissues of the extremities. Like atypical lipomatous tumor/well-differentiated liposarcoma, it is characterized by amplification of MDM2 and CDK4 genes on chromosome 12 (Crago AM et al. Curr Opin Oncol 2011; 23: 373– 378). Possible symptoms of mediastinal liposarcoma are dyspnea, wheezing, chest pain, cough, superior vena cava syndrome, and weight loss (Macchiarini P et al. Lancet Oncol 2004; 5: 107–118).