Reverse double inversion-recovery: Improving motion robustness of cardiac T2 -weighted dark-blood turbo spin-echo sequence

BACKGROUND

Cardiac dark-blood turbo spin-echo (TSE) imaging is sensitive to through-plane motion, resulting in myocardial signal reduction.

PURPOSE

To propose and validate reverse double inversion-recovery (RDIR)-a dark-blood preparation with improved motion robustness for the cardiac dark-blood TSE sequence.

STUDY TYPE

Prospective.

POPULATION

Healthy volunteers (n = 10) and patients (n = 20).

FIELD STRENGTH

1.5T (healthy volunteers) and 3T (patients).

ASSESSMENT

Compared to double inversion recovery (DIR), RDIR swaps the two inversion pulses in time and places the slice-selective 180° in late-diastole of the previous cardiac cycle to minimize slice misregistration. RDIR and DIR were performed in the same left-ventricular basal short-axis slice. Healthy subjects were imaged with two preparation slice thicknesses, 110% and 200%, while patients were imaged using a 200% slice thickness only. Images were assessed quantitatively, by measuring the myocardial signal heterogeneity and the extent of dropout, and also qualitatively on a 5-point scale.

STATISTICAL TESTS

Quantitative and qualitative data were assessed with Student's t-test and Wilcoxon signed-rank test, respectively.

RESULTS

In healthy subjects, RDIR with 110% slice thickness significantly reduced signal heterogeneity in both the left ventricle (LV) and right ventricle (RV) (LV: P = 0.006, RV: P < 0.0001) and the extent of RV dropout (P < 0.0001), while RDIR with 200% slice thickness significantly reduced RV signal heterogeneity (P = 0.001) and the extent of RV dropout (P = 0.0002). In patients, RDIR significantly reduced RV myocardial signal heterogeneity (0.31 vs. 0.43; P = 0.003) and the extent of RV dropout (24% vs. 46%; P = 0.0005). LV signal heterogeneity exhibited a trend towards improvement with RDIR (0.12 vs. 0.16; P = 0.06). Qualitative evaluation showed a significant improvement of LV and RV visualization in RDIR compared to DIR (LV: P = 0.04, RV: P = 0.0007) and a significantly improved overall image quality (P = 0.03).

DATA CONCLUSION

RDIR TSE is less sensitive to through-plane motion, potentiating increased clinical utility for black-blood TSE.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1498-1508.

Radiography of cardiac conduction devices: a pictorial review of pacemakers and implantable cardioverter defibrillators

Cardiac conduction devices (CCDs) depend on correct anatomic positioning to function properly. Chest radiography is the preferred imaging modality to evaluate CCD's anatomic location, lead wire integrity, and help in identifying several complications. In this pictorial review, our goal is to familiarize radiologists with CCD implantation techniques, appropriate positioning of the device, common causes of malfunction, methods to improve report accuracy, and assure maximal therapeutic benefit.

Cystic adnexal mass in a 16-year-old female: Ovarian pathology or complication of a Müllerian anomaly?

Patient: Female, 16

Final Diagnosis: Pelvic mass

Symptoms: None

Medication: None

Clinical Procedure: CT • MRI

Specialty: Diagnostic radiology • pediatrics

Identification of nerve plexi in connective tissues of the sea cucumber Holothuria glaberrima by using a novel nerve-specific antibody

The echinoderm nervous system is one of the least studied among invertebrates, partly because the tools available to study the neurobiology of this phylum are limited. We have now produced a monoclonal antibody (RN1) that labels a nervous system component of the sea cucumber Holothuria glaberrima. Western blots show that our antibody recognizes a major band of 66 kDa and a minor band of 53 kDa. Immunohistological experiments show that, in H. glaberrima, the antibody distinctly labels most of the known nervous system structures and some components that were previously unknown or little studied. A surprising finding was the labeling of nervous plexi within the connective tissue compartments of all organs studied. Double labeling with holothurian neuropeptides and an echinoderm synaptotagmin showed that RN1 labeled most, if not all, of the fibers labeled by these neuronal markers, but also a larger component of cells and fibers. The presence of a distinct connective tissue plexus in holothurians is highly significant since these organisms possess mutable connective tissues that change viscosity under the control of the nervous system. Therefore, the cells and fibers recognized by our monoclonal antibodies may be involved in controlling tensility changes in echinoderm connective tissue.

Preparation and assessment of glutaraldehyde-crosslinked collagen–chitosan hydrogels for adipose tissue engineering

A portfolio of crosslinked chitosan:collagen blends was prepared, and their microarchitecture and water binding capacity were studied to investigate their application for adipose tissue engineering. Glutaraldehyde (GA) concentration had little effect on scaffold morphology or water binding capacity. However, the processing freezing temperature prior to lyophilization affected both. In vitro cytocompatibility of pre-adipocytes (PAs) was assessed for a candidate collagen:chitosan blend using two assays. Results confirm the viability of PAs on GA-crosslinked collagen:chitosan scaffolds. A rat subcutaneous pocket assay was employed to assess PA-seeded scaffolds in vivo. Animal tests proved that PA-seeded scaffolds were biocompatible, could induce vascularization, and form adipose tissue.