Endovascular therapies for hepatic artery stenosis post liver transplantation

PURPOSE

To evaluate primary patency at 12 months after endovascular therapies in hepatic artery stenosis.

METHODS

A retrospective review of all endovascular interventions for hepatic artery stenosis (HAS) after liver transplantation that occurred between June 2013 and November 2020 was performed at a single institution in France. Follow up occurred from 1 month to 4 years (median 15 months). The treatment consisted of dilation with a balloon or stent. We analyzed short-term (technical success and complications) and long-term outcomes (liver function, arterial patency, graft survival at 12 months (GS), and reintervention). We also compared percutaneous balloon angioplasty (PBA) with stent placement. PBA alone was used if < 30% residual stenosis of the hepatic artery was achieved. Stenting was performed if there was greater than 30% residual stenosis and in the case of complications (dissection or rupture).

RESULTS

A total of 18 stenoses were suspected on the basis of routine surveillance duplex ultrasound imaging (peak systolic velocity > 200 cm/s, systolic accelerating time > 10 ms and resistive index < 0.5), all of which were confirmed by angio CT, but only 17 were confirmed by angiography. Seventeen patients were included (14 males, mean age 57 years; and three females, mean age 58 years). Interventions were performed in 17 cases (95%) with PBA only (5/17), stent only (5/17) or both (4/17). Immediate technical success was 100%. Major complications occurred in 1 of 17 cases (5.8%), consisting of target vessel dissection. The analysis of the three (groups PBA only, stent only or both) showed the same procedural success (100%), GS (100%) and normal liver function after the procedures but different rates of complications (20% vs. 0% vs. 0%), arterial patency at 12 months (60% vs. 80% vs. 85%) (p = 0.4), early stenosis (40% vs. 80% vs. 0%) or late stenosis (60% vs. 20% vs. 100%) and requirement for reintervention (40% vs. 20% vs. 14%) (p = 0.56).

CONCLUSION

This study suggests that PBA, stent, or both procedures show the same primary patency at 12 months. It is probably not a definitive answer, but these treatments are safe and effective for extending graft survival in the context of graft shortages.

The HLA-G immune checkpoint: a new immuno-stimulatory role for the α1-domain-deleted isoform

The heterogeneity of cancer cells, in part maintained via the expression of multiple isoforms, introduces significant challenges in designing effective therapeutic approaches. In this regard, isoforms of the immune checkpoint HLA-G have been found in most of the tumors analyzed, such as ccRCC, the most common human renal malignancy. In particular, HLA-G∆α1, which is the only HLA-G isoform described that lacks the α1 extracellular domain, has been newly identified in ccRCC and now here in trophoblasts. Using a cellular model expressing HLA-G∆α1, we have uncovered its specific and overlapping functional roles, relative to the main HLA-G isoform, i.e., the full-length HLA-G1. We found that HLA-G∆α1 has several particular features: (i) although possessing the α3 domain, it does not associate with β2-microglobulin; (ii) it may not present peptides to T cells due to absence of the peptide-binding groove; and (iii) it exerts immune-stimulatory activity towards peripheral blood NK and T cells, while all known isoforms of HLA-G are immune-inhibitory checkpoint molecules. Such immune-stimulatory properties of HLA-G∆α1 on the cytotoxic function of peripheral blood NK cells are individual dependent and are not exerted through the interaction with the known HLA-G receptor, ILT2. Importantly, we are faced here with a potential antitumor effect of an HLA-G isoform, opposed to the pro-tumor properties described for all other HLA-G isoforms, which should be taken into account in future therapeutic designs aimed at blocking this immune checkpoint.

Multimodal imaging assessment of left atrial strain in cardiac amyloidosis and hypertrophic cardiomyopathies

Funding Acknowledgements

Type of funding sources: None.

Background

Despite the increasing number of studies concerning Left Atrial Strain (LAS), few data are available comparing LAS patients with cardiac amyloidosis (CA) and sarcomeric hypertrophic cardiomyopathies (HCM).

Purposes

We aimed to perform a comparative multimodal imaging analysis of LAS of a prospective cohort of patients with CA and HCM.

Methods

For each enrolled patient, we performed same-day two and three-dimension echocardiography (TTE) and cardiac magnetic resonance imaging (CMR) to blindly measure the peak atrial longitudinal strain (PALS) and the peak atrial contraction strain (PACS). Patients with acute atrial fibrillation were excluded.

Results

  Between January 2020 and July 2021, 67 patients were included: 31 patients with CA (age 75.1 ± 10 years, left ventricular ejection fraction 60.6 ± 10.4%, maximum left ventricular thickness 17.8 ± 3.9 mm) and 36 with HCM (age 50.8 ± 15.5 years, left ventricular ejection fraction 66.1 ± 9.8%, maximum left ventricular thickness 20.7 ± 4.5 mm). Left atrial volume was similar in the 2 groups (42.5 ± 15.6 mL/m2 in HCM vs 47.9 ± 15 in CA, P = 0.1557).

Concerning PALS, its values for CA and for CMH were on 2D TTE manual (10.9 ± 5.8% vs 21.4 ± 9.4%, P &lt; 0.001), 2D TTE automatic (11.5 ± 7.3% vs 22.9 ± 10.2%, P &lt; 0.001), 3D TTE (10 ± 6.8% vs 18.1 ± 6.7%, P &lt; 0.001), and CMR (11.3 ± 8 vs 24.4 ± 17.1, P &lt; 0.001) respectively.

Concerning PACS, its values for CA and for CMH were on 2D TTE manual (5.2 ± 3.4% vs 10 ± 4%, P &lt; 0.001), 2D TTE automatic (4.9 ± 3.9% vs 10.2 ± 5.1%, P &lt; 0.001), 3D TTE (3.6 ± 3.8% vs 7.9 ± 4%, P = 0.001) and CMR (6.2 ± 5.8% vs 11.9 ± 9%, P = 0.004) respectively.

Multivariate analysis adjusted on main factors influencing LAS (left ventricular (LV) mass, LV ejection fraction, LV global longitudinal strain, renal function and history of hypertension) found that the differences between the two groups remained significant for PALS and PACS for almost all technics.

Furthermore, although concordance between the 3 echocardiographic technics was excellent (the interclass correlation coefficient (ICC) was higher than 0.80 between each TTE methods), ICC was poor between TTE and CMR technics: 0.40 (0.18-0.59) for manual 2D TTE and CMR, 0.46 (0.24-0.63) for auto 2D TTE and CMR, 0.40 (0.14-0.60) for 3D TTE and CMR.

Conclusion

Our study is the first to describe and compare, both on TTE and CMR, LAS on a prospective cohort of patients with CA and HCM. Although they have same mean left atrial volume, we found significant differences on PALS and PACS between these two groups of patients on all the studied technics. These findings may be used in future multi-modality imaging studies dealing with diagnosis or prognosis of these hypertrophic cardiopathies. Abstract Figure. LAS 2D TTE manual  Abstract Figure. LAS comparison between CA and HCM

Joint Position Paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology (SFC) and the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV) on magnetic resonance imaging in patients with cardiac electronic implantable devices

Magnetic resonance imaging (MRI) has become the reference imaging for the management of a large number of diseases. The number of MR examinations increases every year, simultaneously with the number of patients receiving a cardiac electronic implantable device (CEID). A CEID was considered an absolute contraindication for MRI for years. The progressive replacement of conventional pacemakers and defibrillators by MR-conditional CEIDs and recent data on the safety of MRI in patients with "MR-nonconditional" CEIDs have progressively increased the demand for MRI in patients with a CEID. However, some risks are associated with MRI in CEID carriers, even with "MR-conditional" devices because these devices are not "MR-safe". A specific programing of the device in "MR-mode" and monitoring patients during MRI remain mandatory for all patients with a CEID. A standardized patient workflow based on an institutional protocol should be established in each institution performing such examinations. This joint position paper of the Working Group of Pacing and Electrophysiology of the French Society of Cardiology and the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV) describes the effect and risks associated with MRI in CEID carriers. We propose recommendations for patient workflow and monitoring and CEID programming in MR-conditional, "MR-conditional nonguaranteed" and MR-nonconditional devices.

Quantification of diffuse myocardial fibrosis using CMR extracellular volume fraction and serum biomarkers of collagen turnover with histologic quantification as standard of reference

PURPOSE

To compare the assessment of diffuse interstitial myocardial fibrosis in valvular diseases using cardiac magnetic resonance (CMR) extracellular volume fraction (ECV) quantification and serum biomarkers of collagen turnover using results of myocardial biopsy as standard of reference.

MATERIALS AND METHODS

This prospective monocentric study included consecutive patients before aortic valvular replacement. All patients underwent: i), 1.5T CMR with pre and post contrast T₁ mapping sequence and ECV computation; ii), serum quantification of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) and iii), myocardial biopsies were collected during surgery to assess collagen volume fraction (CVF). Patients with coronary artery disease were excluded. Correlation between native T1, ECV, CVF and serum biomarkers were assessed using Pearson correlation test. Agreement between basal anteroseptal ECV with global ECV was assessed using Bland-Altman test.

RESULTS

Twenty-one patients, 16 with aortic stenosis and 5 with aortic regurgitation were included. There were 12 men and 9 women with a mean age of 74.1±6.8 (SD) years (range: 32-84 years). Mean global ECV value was 26.7±2.7 (SD) % (range: 23.4-32.5%) and mean CVF value was 12.4±9.7% (range: 3.2-25.7%). ECV assessed at the basal anteroseptal segment correlated moderately with CVF (r=0.6; P=0.0026). There was a strong correlation and agreement between basal anteroseptal ECV and global ECV, (r=0.8; P<0.0001; bias 5.4±6.1%) but no correlation between global ECV and CVF (r=0.5; P=0.10). Global ECV poorly correlated with serum TIMP-1 (r=0.4; P=0.037) and MMP-2 (r=0.4; P=0.047). No correlation was found between serum biomarkers and basal anteroseptal- ECV or native T1.

CONCLUSION

In patients with severe aortic valvulopathy, diffuse myocardial fibrosis assessed by anterosepto-basal ECV correlates with histological myocardial fibrosis. Anteroseptobasal ECV strongly correlates with global ECV, which poorly correlates with TIMP-1 and MMP-2, serum biomarkers involved in the progression of heart failure.

Pediatric cardiac computed tomography angiography: Expert consensus from the Filiale de Cardiologie Pédiatrique et Congénitale (FCPC) and the Société Française d'Imagerie Cardiaque et Vasculaire diagnostique et interventionnelle (SFICV)

This article was designed to provide a pediatric cardiac computed tomography angiography (CCTA) expert panel consensus based on opinions of experts of the Société Française d'Imagerie Cardiaque et Vasculaire diagnostique et interventionnelle (SFICV) and of the Filiale de Cardiologie Pédiatrique Congénitale (FCPC). This expert panel consensus includes recommendations for indications, patient preparation, CTA radiation dose reduction techniques, and post-processing techniques. The consensus was based on data from available literature (original papers, reviews and guidelines) and on opinions of a group of specialists with extensive experience in the use of CT imaging in congenital heart disease. In order to reach high potential and avoid pitfalls, CCTA in children with congenital heart disease requires training and experience. Moreover, pediatric cardiac CCTA protocols should be standardized to acquire optimal images in this population with the lowest radiation dose possible to prevent unnecessary radiation exposure. We also provided a suggested structured report and a list of acquisition protocols and technical parameters in relation to specific vendors.

Cytometry-based analysis of HLA-G functions according to ILT2 expression

HLA-G was described as a molecule inhibiting NK and T cells functions through its receptor, ILT2. However, most functional studies of HLA-G were so far performed on heterogeneous immune populations and regardless of ILT2 expression. This may lead to an underestimation of the effect of HLA-G. Thus, considering the immune subpopulations sensitive to HLA-G remained an important issue in the field. Here we present a new cytometry assay to evaluate HLA-G effects on both NK and CD8⁺ T cell cytotoxic functions. Using flow cytometry allows for the comparison of HLA-G function on multiple subsets and multiple functions in the same time. In particular, we sharpen the analysis by specifically studying the immune subpopulations expressing HLA-G receptor ILT2. We focused our work on: IFN-gamma production and cytotoxicity (CD107a expression) by CD8⁺ T cells and NK cells expressing or not ILT2. We compared the expression of these markers in presence of target cells, expressing or not HLA-G1, and added a blocking antibody to reverse HLA-G inhibition. This new method allows for the discrimination of cell subsets responding and non-responding to HLA-G1 in one tube. We confirm that HLA-G-specifically inhibits the ILT2⁺ CD8⁺ T cell and ILT2⁺ NK cell subsets but not ILT2-negative ones. By blocking HLA-G/ILT2 interaction using an anti-ILT2 antibody we restored the cytotoxicity level, corroborating the specific inhibition of HLA-G1. We believe that our methodology enables to investigate HLA-G immune functions easily and finely towards other immune cell lineages or expressing other receptors, and might be applied in several pathological contexts, such as cancer and transplantation.

CD8+PD-1-ILT2+ T Cells Are an Intratumoral Cytotoxic Population Selectively Inhibited by the Immune-Checkpoint HLA-G

Only some cancer patients respond to the immune-checkpoint inhibitors being used in the clinic, and other therapeutic targets are sought. Here, we investigated the HLA-G/ILT2 checkpoint in clear-cell renal-cell carcinoma (ccRCC) patients and focused on tumor-infiltrating CD8⁺ T lymphocytes (TIL) expressing the HLA-G receptor ILT2. Using transcriptomics and flow cytometry, we characterized both peripheral blood and tumor-infiltrating CD8⁺ILT2⁺ T cells from cancer patients as late-differentiated CD27^-CD28^-CD57⁺ cytotoxic effectors. We observed a clear dichotomy between CD8⁺ILT2⁺ and CD8⁺PD-1⁺ TIL subsets. These subsets, which were sometimes present at comparable frequencies in TIL populations, barely overlapped phenotypically and were distinguished by expression of exclusive sets of surface molecules that included checkpoint molecules and activating and inhibitory receptors. CD8⁺ILT2⁺ TILs displayed a more mature phenotype and higher expression of cytotoxic molecules. In ex vivo functional experiments with both peripheral blood T cells and TILs, CD8⁺ILT2⁺ T cells displayed significantly higher cytotoxicity and IFNγ production than their ILT2^- (peripheral blood mononuclear cells, PBMC) and PD-1⁺ (TILs) counterparts. HLA-G expression by target cells specifically inhibited CD8⁺ILT2⁺ T-cell cytotoxicity, but not that of their CD8⁺ILT2^- (PBMC) or CD8⁺PD-1⁺ (TIL) counterparts, an effect counteracted by blocking the HLA-G/ILT2 interaction. CD8⁺ILT2⁺ TILs may therefore constitute an untapped reservoir of fully differentiated cytotoxic T cells within the tumor microenvironment, independent of the PD1⁺ TILs targeted by immune therapies, and specifically inhibited by HLA-G. These results emphasize the potential of therapeutically targeting the HLA-G/ILT2 checkpoint in HLA-G⁺ tumors, either concomitantly with anti-PD-1/PD-L1 or in cases of nonresponsiveness to anti-PD-1/PD-L1.

In Vivo Feasibility of Arterial Embolization with Permanent and Absorbable Suture: The FAIR-Embo Concept

PURPOSE

Arterial embolization has been shown to be effective and safe for the management of bleeding, especially for postpartum and pelvic traumatic bleeding. We propose to evaluate the proof of concept of feasibility and effectiveness of arterial embolization with absorbable and non-absorbable sutures in a porcine model.

MATERIALS AND METHODS

In the acute setting (n = 1), several different arteries (mesenteric, splenic, pharyngeal, kidney) were embolized using non-absorbable sutures (NAS): Mersutures™ braided sutures (polyethylene terephthalate). In the chronic setting (n = 3), only lower pole renal arteries were embolized. On the right side, NAS was used, whereas on the left side embolization was realized with absorbable suture (AS): Vicryl^® braided suture (polyglactin 910). The chronic group was followed for 3 months. The pigs received contrast-enhanced CT the day before embolization (D-1), after the embolization (D0), at 1 month and 3 months after embolization (M1 and M3); digital subtraction angiography (DSA) was done at D0 and M3 and histological analysis at M3.

RESULTS

All vascular targets were effectively embolized without any pre- or postoperative complications. Both DSAs and CTs at M3 showed a 100% recanalization rate for the AS embolization and a partial reversal rate for the NAS embolization. A renal hypotrophy in the embolized region was observed during both the M1 and M3 scans for both sutures (AS and NAS) with a clear hypotrophy for the NAS embolized kidney.

CONCLUSION

Embolization by AS and NAS (FAIR-Embo) is a feasible and effective treatment which opens up the possibility of global use of this inexpensive and widely available embolization agent.

Distribution of left ventricular trabeculation across age and gender in 140 healthy Caucasian subjects on MR imaging

PURPOSE

The purpose of this study was to quantify the distribution of trabeculated (T) and compact (C) left ventricular (LV) myocardium masses in a healthy Caucasian population against age, gender and LV parameters, and to provide normal values for T, C and T/C.

MATERIALS AND METHODS

One hundred and forty healthy subjects were prospectively recruited and underwent cardiac MRI at 1.5T with a stack of short-axis cine sequences covering the entire LV. End-diastolic volume (EDV), C and T masses were quantified using a semi-automatic method. Ejection fraction (EF) and T/C ratio were computed.

RESULTS

We included 70 men and 70 women with a mean age of 44±14 (SD) years (range: 20-69 years). The mean EF was 63.7±6.3 (SD) % (range: 50.7-82.0%), the mean EDV was 75.9±16.2 (SD) mL/m² (range: 36.4-112.2mL/m²), the mean C mass was 53.9±11.2 (SD) g/m² (range: 26.5-93.4g/m²) and the mean T mass was 4.9±2.4 (SD) g/m² (range: 1.1-11.4g/m²). The T/C ratio was 9.2±4.5% (range: 2.0-29.4%). Multivariate ANOVA test showed that the compact mass was influenced by EDV (P<0.0001), EF (P=0.001) and gender (P<0.0001), and the trabeculated mass depended on EDV (P<0.0001), gender (P=0.002) and age (P<0.0001), while the T/C ratio was only influenced by age (P=0.0003). Spearman test showed a correlation between EDV and C (r=0.60; P<0.0001),T (r=0.46; P<0.0001) and T/C ratio (r=0.26; P=0.0023).T and T/C ratio correlated with EF (r=-0.18, P=0.0373; r=-0.18, P=0.0321, respectively).

CONCLUSION

While the compact and trabeculated myocardium masses appear to relate separately to the cardiac function, age and gender, their ratio T/C appears to only decrease with age. Furthermore, we propose here normal values for T, C and T/C in a cohort of healthy Caucasians subjects.

Embolization of ovarian vein for pelvic congestion syndrome with ethylene vinyl alcohol copolymer (Onyx®)

PURPOSE

To evaluate the safety and efficacy of pelvic embolization using ethylene vinyl alcohol copolymer (Onyx^®) for pelvic congestion syndrome.

MATERIAL AND METHODS

Between March 2012 to September 2016, 17 women (mean age, 44.7± 12.2 (SD) years; range: 34-71years) presenting with pelvic congestion syndrome were evaluated for transvenous embolization with Onyx^®. Pelvic congestion syndrome was initially diagnosed by clinical examination and the results of transvaginal Doppler ultrasound and further confirmed by pelvic venography. Primary and secondary clinical efficacy was defined respectively by the resolution of the symptoms after embolization and at the end of the follow-up, irrespective to the number of embolization procedures.

RESULTS

Technical efficacy of embolization was 100% with no significant complications during and after embolization. After a mean follow-up time of 24.2 months (range: 6-69months) a primary and secondary clinical efficacy of 76.4% (13/17 women) and 94.1% (16/17 women) respectively were observed. Four women (23.5%) underwent a second embolization procedure with one woman requiring a third embolization procedure. These additional embolization procedures were associated with direct puncture of vulvar varices for sclerotherapy in two women. Five women (29%) had recurrent symptoms 21 months post-treatment (7-42months).

CONCLUSION

Pelvic embolization using ethylene vinyl alcohol copolymer (Onyx^®) has a favorable clinical success for pelvic congestion syndrome.

Exenatide decreases liver fat content and epicardial adipose tissue in patients with obesity and type 2 diabetes: a prospective randomized clinical trial using magnetic resonance imaging and spectroscopy

AIM

To conduct a prospective randomized trial to investigate the effect of glucagon-like peptide-1 (GLP-1) analogues on ectopic fat stores.

METHODS

A total of 44 obese subjects with type 2 diabetes uncontrolled on oral antidiabetic drugs were randomly assigned to receive exenatide or reference treatment according to French guidelines. Epicardial adipose tissue (EAT), myocardial triglyceride content (MTGC), hepatic triglyceride content (HTGC) and pancreatic triglyceride content (PTGC) were assessed 45 min after a standardized meal with 3T magnetic resonance imaging and proton magnetic resonance spectroscopy before and after 26 weeks of treatment.

RESULTS

The study population had a mean glycated haemoglobin (HbA1c) level of 7.5 ± 0.2% and a mean body mass index of 36.1 ± 1.1 kg/m(2) . Ninety five percent had hepatic steatosis at baseline (HTGC ≥ 5.6%). Exenatide and reference treatment led to a similar improvement in HbA1c (-0.7 ± 0.3% vs. -0.7 ± 0.4%; p = 0.29), whereas significant weight loss was observed only in the exenatide group (-5.5 ± 1.2 kg vs. -0.2 ± 0.8 kg; p = 0.001 for the difference between groups). Exenatide induced a significant reduction in EAT (-8.8 ± 2.1%) and HTGC (-23.8 ± 9.5%), compared with the reference treatment (EAT: -1.2 ± 1.6%, p = 0.003; HTGC: +12.5 ± 9.6%, p = 0.007). No significant difference was observed in other ectopic fat stores, PTGC or MTGC. In the group treated with exenatide, reductions in liver fat and EAT were not associated with homeostatic model assessment of insulin resistance index, adiponectin, HbA1c or fructosamin change, but were significantly related to weight loss (r = 0.47, p = 0.03, and r = 0.50, p = 0.018, respectively).

CONCLUSION

Our data indicate that exenatide is an effective treatment to reduce liver fat content and epicardial fat in obese patients with type 2 diabetes, and these effects are mainly weight loss dependent.

Preclinical study on an animal model of a new non-adhesive cyanoacrylate (Purefill®) for arterial embolization

PURPOSE

The goal of this study was to assess the distal dispersion, the adhesion strength to catheter, the vascular toxicity and the ability in excluding embolized vessels using Purefill^® (α-hexil-cyanoacrylate) as embolic material, which is a new high purity cyanoacrylate and compare these results with those obtained with N-butyl-2-cyanoacrylate (Histoacryl^®) and a mixture of N-butyl-2-cyanoacrylate and methacryloxysulfolane.

MATERIAL AND METHODS

In six pigs, the right rete mirabile (RM) and right renal arteries were embolized with α-hexil-cyanoacrylate, and the left rete mirabile and left renal artery were embolized with N-butyl-2-cyanoacrylate and N-butyl-2-cyanoacrylate+Methacryloxysulfolane for comparison. One minute after glue injection through the microcatheter, displacements of the kidney and the pharyngeal artery were measured on angiographic images, before exercising any traction and during catheter pulling, when the forces were maximal. Displacement was measured in terms of distance (mm) with respect to renal pedicles and in terms of angle (°) with respect to the rete. After acute embolization (4 pigs) or three-month follow-up (2 pigs), the kidneys and the RM were removed and further analysed using computed tomography and histopathological examination.

RESULTS

Similar short and long-term embolic efficacies were observed with the three glues. The mean displacement distances of renal pedicles were 2.6mm for α-hexil-cyanoacrylate, 22.6mm for N-butyl-2-cyanoacrylate and 19.8mm for N-butyl-2-cyanoacrylate+Methacryloxysulfolane (P=0.021). The mean angles of displacement of the ascending pharyngeal arteries were for 12.2° for α-hexil-cyanoacrylate, 23.5° for N-butyl-2-cyanoacrylate and 30° for N-butyl-2-cyanoacrylate+Methacryloxysulfolane (P=0.070). Histopathologically, findings were similar for the three glues, immediately and 90 days after embolization.

CONCLUSION

α-hexil-cyanoacrylate has occlusive efficacy in the short and long term similar to those of N-butyl-2-cyanoacrylate and N-butyl-2-cyanoacrylate+Methacryloxysulfolane. In addition, histopathological changes are similar with the three glues immediately or 90 days after embolization. Conversely, α-hexil-cyanoacrylate results in a reduced angle and distance of displacement compared to the other two glues, assumably reflecting a limited adhesive strength.

Imaging of acquired coronary diseases: From children to adults

Acquired coronary diseases include aneurysms, fistulae, dissections, and stenosis. Aneurysms may occur secondarily to Kawasaki disease, a childhood vasculitis, the prognosis of which depends on the coronary involvement, or they may be degenerative, infectious, inflammatory, or traumatic in origin. Fistulae develop between the coronary arterial system and a pulmonary or bronchial artery, or cardiac cavity. Dissections may occur spontaneously or may be post-traumatic. These coronary abnormalities may be found incidentally or may present as complications, infarction or rupture. The goals of this article are to understand acquired childhood and adult coronary diseases and their usual means of presentation, the ways of investigating them, and the principles of their treatment.

MR imaging of arrhythmogenic right ventricular dysplasia: What the radiologist needs to know

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited heart muscle disease that predominantly affects the right ventricle. Clinical manifestations are related to severe ventricular arrhythmia that may lead to sudden death, mostly in young patients. Magnetic resonance imaging (MRI), included in the new diagnostic criteria since 2010, aims to detect segmental and global wall motion abnormalities, reduced ejection fraction, right ventricular dilatation and right ventricular diastolic/systolic dysfunction. An MRI assessment of the right ventricle is often challenging, partly because the MRI diagnostic criteria have some limitations, and also because it requires a significant learning curve due to the low prevalence of the disease. Therefore, this article aims to review the pathophysiology of the disease, the cardiac MRI protocol, images of the various stages of this affection as well as the differential diagnosis.

MRI monitoring of myocardial iron overload: use of cardiac MRI combined with hepatic MRI in a cohort of multi-transfused patients with thalassaemia

PURPOSE

We report the results of combining cardiac and hepatic MRI in the same examination to monitor 48 multi-transfused patients presenting iron overload secondary to their transfusions. This cardiac MRI technique uses acquisition sequences and calculation software that are readily available for 1.5 T systems, and it has been validated to screen for patients at risk of cardiac complications who present myocardial iron overload (T2*<20milliseconds).

PATIENTS AND METHODS

A total of 176 combined MRI examinations were performed between May 2006 and January 2012 in 48 patients who had received transfusions due to thalassaemia. This monocentric retrospective study brings together all of the imaging examinations carried out.

RESULTS

There was a positive correlation between the cardiac T2* values and left ventricular ejection fraction, which were measured in the same examination. At the first assessment 23/48 patients had a T2*<20ms. These patients showed a significant improvement in cardiac T2* over time while their iron chelation therapy was being intensified.

CONCLUSION

This study validates the application of the cardiac MRI technique used to monitor cardiac iron overload in patients who have undergone multiple transfusions.

[Improvement of pulmonary angiography in the framework of a maintenance of certification]

PURPOSE

This evaluation of clinical practices (pulmonary embolus) was performed to evaluate the quality of CT pulmonary angiograms for suspected acute pulmonary embolus.

MATERIALS AND METHODS

Five validated criteria evaluating both the acquisition technique and the quality of image interpretation were selected: slice thickness, pulmonary arterial enhancement over 250 HU, caudocranial acquisition, visualization of fifth order pulmonary arterial branches, and right-left ventricular ratio in the presence of pulmonary embolus. Forty CT pulmonary angiograms were reviewed before and after implementation of a practice quality improvement program: modification of acquisition protocol, training of medical and paramedical staff, and implementation of a standardized radiology report.

RESULTS

Thin collimation was already implemented. The implementation of two other technical parameters significantly improved the technical quality of the examinations. The detection of findings with adverse clinical outcome was also significantly improved. Only the accuracy of detection of embolus involving fifth order pulmonary arterial branches could not be improved, a criteria allowing formal exclusion of pulmonary embolus.

CONCLUSION

This study resulted in an improvement in the quality of CT pulmonary angiograms and increased awareness of radiologists for the prognostic value of right ventricular dilatation. It has also underscored the need for quality control of a CT pulmonary angiogram prior to interpretation.

[Mechanisms of delayed myocardial enhancement and value of MR and CT contrast materials in the evaluation of myocardial viability]

The purpose of this article is to present a brief theoretical review of the models characterizing delayed myocardial enhancement applicable to both MR and CT imaging, review the different characteristics of commercially available gadolinium-based and iodinated contrast materials, and summarize the literature on the potential value of dedicated MR imaging contrast currently in development for the diagnosis of myocardial viability. The intensity of myocardial enhancement following infarction is related to two factors: expansion of the interstitial volume (15+/-2% in normal myocardium and 80+/-3% within necrosis) secondary to cell necrosis and perfusion abnormalities due to the absence of revascularization or lesions to the microcirculation. A kinetic model of contrast material properties within myocardium could be constructed from Kety's equation with regards to enhancement within the different myocardial tissues (viable myocardium, necrotic myocardium, fibrosis, no-reflow zones, stunned or hibernating myocardium). This model can be applied to both CT and MR since clinically available contrast agents are extracellular, inert and kinetically comparable. The development of dedicated contrast agents for viability and necrosis or molecular contrast agents open new horizons for preclinical research.

[Urokinase in the management of occluded PICC lines]

PURPOSE

To determine the efficacy and safety of urokinase in the management of occluded PICC lines.

MATERIALS AND METHODS

A total of 587 PICC lines were placed over an 11 month period. During this period, 28 PICC lines (4.8%) became occluded: 12 occluded PICC lines were successfully managed by simple flushing with normal saline while 16 PICC lines were thrombolyzed with urokinase.

RESULTS

After urokinase, 93.8% (15/16) of occluded PICC lines were completely patent. A single infusion of urokinase, 20,000 IU over 30 minutes, was used in all cases. No secondary occlusion or complication was noted after urokinase.

CONCLUSION

Urokinase is effective and safe to restore patency to occluded PICC lines. The procedure is simple, and could be performed at the bedside by nursing staff after medical prescription. It is an alternative to over the wire PICC line exchange, that could reduce the risk of complication related to manipulations, patient discomfort and cost.

[Imaging of mediastinal tumors]

Imaging of mediastinal tumors is an important part of the diagnostic workup in patients presenting symptoms suggestive of compression of one or more of the mediastinal components. In other cases, lesions growing within the mediastinum remain asymptomatic and are diagnosed when chest X-ray or CT are routinely performed for other indications. CT remains the most available and reliable tool among the different imaging methods. Due to its permanent technical improvements, it can be used as the one-step answer to all the requirements of the pretherapeutic evaluation of a mediastinal mass. Chest plain film is still needed as the first line examination in order to carefully select the acquisition protocol for CT. MR did not demonstrate any superiority to CT except for the preoperative workup of lesions arising in the posterior part of the mediastinum. MR remains an interesting tool for tissue characterisation. Topography of mediastinal lesions (based upon the definition of mediastinal compartments) is one of the guides through the diagnostic pathway in imaging these tumors. The other one is their main tissue component, so that cystic, fatty and soft tissue masses can be differentiated.

[Technological advances in cardiac CT]

The SFR-SFC presents guidelines dedicated to cardiac and coronary imaging using CT in the area of indications, technological requirement including both hardware and software, patient conditioning, CT protocols and related results concerning radiation dose, image quality and diagnostic value. These guidelines are based either on up-dated medical literature proofs and/or on expert consensus.

Astrocytic protection of spinal motor neurons but not cortical neurons against loss of Als2/alsin function

Three neurodegenerative diseases affecting upper and/or lower motor neurons have been associated with loss of ALS2/Alsin function: juvenile amyotrophic lateral sclerosis, primary lateral sclerosis and infantile-onset ascending hereditary spastic paralysis. The distinct neuronal vulnerability and the role of glia in these diseases remains, however, unclear. We here demonstrate that alsin-depleted spinal motor neurons can be rescued from defective survival and axon growth by co-cultured astrocytes. The astrocytic rescue is mediated by a soluble protective factor rather than by cellular contact. Cortical neurons are intrinsically as vulnerable to alsin depletion as spinal motor neurons but cannot be rescued by co-cultured astrocytes. To our knowledge, these data provide the first example of non-cell-autonomous glial effects in a recessive form of motor neuron disease and a potential rationale for the higher vulnerability of upper versus lower motor neurons in ALS2/Alsin-linked disorders.

[Cervical lymph nodes]

Imaging plays a chief role in the care and monitoring of patients in cervico-facial oncology. The radiologist must know the anatomy of different lymph nodes as well as signs of malignancy (hypertrophy, enhancement, necrosis, capsular rupture, etc.). CT is still the first-line examination because of its high reliability, its accessibility and its ability to make an assessment of the upper aero digestive ways at the same time. Ultrasound is very accuracy, and allows the realization of cytoponction, but does not provide a complete exploration of the neck. MRI does not appear to be indicated for the first intention, but the new rapid sequences (STIR, diffusion) seem interesting. The PET-CT is useful in post-therapeutic management of patients, and probably in the initial staging, but its accessibility is poor.

[Mitochondrial cardiomyopathy in an adult: a case history]

We report an original case of mitochondrial cardiomyopathy discovered in a young woman during an episode of cardiac decompensation. The diagnosis was suspected from the echocardiographic appearances of granite-like heterogeneous hypertrophic cardiomyopathy. It was confirmed by endomyocardial biopsies. The clinical evolution was favourable with classical treatment. Mitochondrial cardiomyopathy is a rare cause of cardiomyopathy, generally observed in children, with multisystemic localisation. The pathophysiology and genetics are complex. Cardiac involvement is observed in 25% of cases, with the principal manifestation being hypertrophic cardiomyopathy. In the absence of any specific clinical or paraclinical signs, echocardiography and MRI are the techniques of choice for morphological evaluation. Diagnosis relies upon myocardial biopsy, which should be readily advocated in every unexplained case of cardiomyopathy in a young subject. The prognosis is poor and no specific treatment is available.