Diagnostic accuracy of cardiac magnetic resonance imaging in the detection and characterization of left atrial catheter ablation lesions: a multicenter experience.

INTRODUCTION: We tested the hypothesis that cardiovascular magnetic resonance (CMR) imaging can reliably distinguish the presence or absence of left atrial (LA) ablation lesions by blinded analysis of pre- and postablation imaging. METHODS: Consecutive patients at 2 centers undergoing pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation by either wide area circumferential radiofrequency ablation (WACA) or ostial ablation with a cryoballoon underwent CMR late gadolinium enhancement (LGE) imaging pre- and 3 months postablation. Imaging was anonymized for blinded analysis of (1) LGE images, and (2) a 3D fusion image with LGE projected onto a segmented LA surface. Scans were categorized using both assessment techniques separately as pre- or postablation, and if postablation, whether lesions were in an ostial or WACA distribution. RESULTS: LGE imaging was performed in 50 patients (aged 60 ± 10 years, 68% male, 24 underwent WACA and 26 had cryoablation). Sensitivity and specificity for detection of ablation lesions was 60% and 96% on LGE imaging. Sensitivity was higher using 3D fusion imaging (88%; P = 0.003). The proportion in whom lesions were both detected and the distribution correctly assessed as WACA or ostial was higher with 3D fusion imaging compared to LGE imaging (54% vs 28%; P = 0.014). There was no difference in the detection of radiofrequency ablation lesions compared to cryoablation lesions (58% vs 62%; P = 1.000). CONCLUSION: LGE imaging of atrial scar is not yet sufficiently accurate to reliably identify ablation lesions or to determine lesion distribution.

Resolution of Behçet's syndrome associated pulmonary arterial aneurysms with infliximab.

INTRODUCTION: We describe the successful treatment of pulmonary arterial aneurysms in Behçet's syndrome using a tumor necrosis factor (TNF) inhibitor. METHODS: A case is reported of Behçet's syndrome complicated by pulmonary arterial aneurysms that responded to anti-TNF therapy. This is accompanied by a literature review of previously published cases. We searched the English language medical literature using the PubMed and Medline search terms: "Behçet's," "Pulmonary aneurysms," and "infliximab," "etanercept," or "adalimumab." RESULTS: A 43-year-old man with a 6-month history of oral and genital ulcers, weight loss, and fatigue developed arterial aneurysms in the common carotid and common iliac arteries and thromboses in a femoral vein and pulmonary arteries. Treatment with high-dose oral corticosteroids and pulsed intravenous cyclophosphamide was initiated but while on treatment he developed pulmonary arterial aneurysms with hemoptysis. His treatment was changed to intravenous infliximab with methotrexate to which he showed a good response with marked clinical improvement, reduction in his inflammatory markers, and regression of the pulmonary arterial aneurysms. The review of the literature identified 3 reported cases of treatment of pulmonary arterial aneurysms in Behçet's syndrome with anti-TNF therapy, with good outcomes in each case. CONCLUSIONS: Pulmonary artery aneurysms are important complications of Behçet's syndrome. Anti-TNF inhibitors should be considered in patients who do not respond to treatment with corticosteroids and cyclophosphamide.

Altered myocardial motion pattern in Fabry patients assessed with CMR-tagging.

Progressive left ventricular hypertrophy is the hallmark of cardiac manifestations in patients with Fabry disease. Cardiovascular magnetic resonance with tissue tagging allows detailed assessment of the cardiac motion pattern. The aim was to test the hypothesis that not only Fabry patients with severe left ventricular hypertrophy exhibit changes in myocardial motion, but also Fabry patients with normal left ventricular mass. Magnetic resonance tagging using slice following complementary spatial modulation of magnetization (CSPAMM) combined with harmonic phase analysis (HARP) was applied to measure left ventricular shortening and contraction. Additionally, left ventricular rotation and global left ventricular torsion were examined. Twenty-nine Fabry patients grouped in patients with (n = 13) and without (n = 16) left ventricular hypertrophy were compared with 29 age and sex matched healthy volunteers. Long axis shortening and circumferential contraction showed reduced peak values with increasing left ventricular mass and were significantly reduced in Fabry patients with left ventricular hypertrophy (p < 0.001 and p < 0.05, respectively). Torsional deformation and apical rotation were increased both in Fabry patients with left ventricular hypertrophy as well as in patients with normal left ventricular mass (p < 0.001 for torsion) compared with controls. Applying the magnetic resonance tagging acquisition and analysis methods, myocardial motion abnormalities could not only be measured in Fabry patients with left ventricular hypertrophy but also in patients without macroscopic cardiac involvement.

Gradient-enhanced volume rendering: an image processing strategy to facilitate whole small bowel imaging with MRI.

MRI of the small bowel with positive contrast from orally administered contrast agent is a promising non-invasive imaging method. The aim of our study was to introduce small bowel MRI in a display format that clinicians are accustomed to and that maximizes the amount of information visualized on a single image. Twelve healthy volunteers, median age 32 years (range 18-49 years) participated in the study. A mixture of 20 ml Gd-DOTA (Dotarem), 0.8 g/kg body weight psyllium fibre (Metamucil) and 1.2 l water were sequentially administered over a period of 4 h. Imaging was performed on a 1.5 T unit (Philips Gyroscan, Intera). Fat-saturated, 3D, gradient echo imaging was performed while the patient was in apnea (30 s). Bowel motion was reduced with 40 mg intravenously administered scopolamine (Buscopan). A 3D, gradient-enhanced, volume rendering technique was applied to the 3D data sets. Standard projections [left anterior oblique (LAO), right anterior oblique (RAO), supine and prone] resembling conventional enteroclysis were successfully generated within fewer than 10 min processing time. Reconstructions were reproducible and provided an entire overview of the small bowel. In addition thin-slab volume rendering allowed an overlap-free display of individual structures. Positive contrast from orally administered contrast agent, combined with a gradient enhanced volume rendering method, allows the reconstruction of the small bowel in a pattern resembling conventional double-contrast enteroclysis. Segmental display without overlay is possible.

Small bowel motility assessment with magnetic resonance imaging.

PURPOSE: To assess primarily the feasibility of magnetic resonance imaging (MRI) as a tool to monitor small bowel peristaltic motion and secondarily to validate this technique by demonstrating drug-induced motility changes. MATERIALS AND METHODS: After a standardized oral preparation of Ispaghula husk (Metamucil) and meglumine gadoterate (Gd-DOTA; Dotarem), 10 volunteers underwent dynamic MRI using a two-dimensional turbofast field echo (TFE) sequence with a slice repetition time of 500 msec. Intraluminal cross-sectional caliber changes over time were assessed allowing quantification of the peristaltic frequencies and amplitudes of the small gut on various regions of interest. Pharmacologically induced alterations of the peristaltic motion after spasmolytics and gastrokinetic motion enhancers were investigated. RESULTS: Small bowel diameter measurement resulted in a peristalsis of 10.96 (SD = +/-2.51) waves per minute, oscillating regularly with mean amplitudes of 6.65 mm (SD = +/-1.15 mm). Peristaltic frequency in normal individuals is consistent with that observed with other techniques. Intravenous administration of scopolamine butylbromide (= hyoscine butylbromide/Buscopan) resulted in small bowel paralysis within 21.3 seconds (SD = +/-2.8 seconds). Prokinetic effect of intravenous metoclopramide (Paspertin) after Buscopan paralysis was tested in one volunteer, characterized by a slow recovery of peristalsis, which propagated from the proximal to the distal segments and enhanced contraction amplitudes. CONCLUSION: Dynamic MRI allows observing and quantifying small bowel peristalsis, characterizing motion patterns, and monitoring the effects of interfering factors such as drugs.