Dual breath-hold magnetic resonance cine evaluation of global and regional cardiac function

The purpose of our study was to evaluate the accuracy of a multislice cine magnetic resonance imaging (MRI) technique with parallel imaging in regard to global and regional left ventricular function. Forty-two individuals underwent cine MRI on a 1.5-tesla scanner. Cine MRI used a steady-state free precession technique and was performed as a single-slice technique (nonTSENSE cine) and an accelerated multislice technique (TSENSE cine) with five slices per breath-hold. End diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) were evaluated for all data sets and in regard to regional wall motion and regional wall motion analysis, and quantitative regional wall thickness and systolic thickening were also assessed. EDV, ESV, and EF based on TSENSE cine showed excellent correlation to the nonTSENSE cine approach (all r²=0.99, P<0.001). While EDV evaluations showed a small underestimation for TSENSE cine, ESV and EF showed accurate results compared with nonTSENSE cine. Both readers showed good agreement (κ=0.72) in regional wall motion assessment comparing both techniques. Data acquisition for the multislice approach was significantly shorter (∼75%) that in single-slice cine. We conclude that accurate evaluation of regional wall motion and left ventricular EF is possible using accelerated multislice cine MR with high spatial and temporal resolution.     

MR-compatible assistance system for punction in a high-field system: device and feasibility of transgluteal biopsies of the prostate gland

We present the first cadavic study results concerning the feasibility of the use of an MR-guided assistance system, Innomotion (Innomedic, Herxheim, Germany), for accurate and consistent placement of percutaneous needles in the prostate gland. The MR-compatible assistance system consists of a C-arch, guiding arm and application module (AMO). T1-weighted fast low angle shot (FLASH) 2-D-GRE sequence (TR/TE=110/4 ms) and T2-weighted turbo spin-echo (TSE)-sequences (TR/TE=3200/97 ms) in transversal orientation were used for the monitoring of the punction of the prostate gland. Planning and control of the intervention is to be made outside the scanner room on a desktop computer that receives DICOM images from the scanner. Servopneumatic drives move the AMO to the insertion point. The physician has to introduce the punction needle manually. The mean deviation of the needle tip to the target in a gel phantom was 0.35 mm. An accurate punction of the prostate gland can easily be performed using this system with a transgluteal access. The T2-weighted images are superior for the evaluation of the prostate anatomy and the needle position during the interventions. In conclusion, our preliminary results indicate that this MR-guided assistance system is suitable for an accurate transgluteal needle placement in the prostate.     

Whole-body 3D water/fat resolved continuously moving table imaging

PURPOSE: To study the feasibility of three-dimensional (3D) whole-body, head-to-toe, water/fat resolved MRI, using continuously moving table imaging technology. MATERIALS AND METHODS: Experiments were performed on nine healthy volunteers, acquiring 3D whole-body head-to-toe data under continuous motion of the patient table. Two different approaches for water/fat separation have been studied. Results of a three-point chemical shift encoding and a spectral presaturation technique were compared with respect to image quality and performance. Furthermore, fast, low-resolution, whole-body water/fat imaging was performed in two minutes total scan time to derive patient-specific parameters such as the total water/fat ratio, the intraperitoneal/extraperitoneal fat ratio, and the body mass index (BMI). RESULTS: Good water/fat separation with decent image quality was obtained in all cases. The three-point chemical shift encoding approach was found to be more efficient with respect to signal-to-noise ratio (SNR) and acquisition time. CONCLUSION: Whole-body water/fat sensitive MRI using continuous table motion is feasible and could be of interest for clinical practice. Some improvements of the method are desirable.     

Triage of patients with suspected coronary artery disease using multislice computed tomography

RATIONALE AND OBJECTIVES: Several studies have shown that multislice computed tomography (MSCT) has a high sensitivity and specificity for detecting coronary artery stenoses. The aim of the present study was to investigate whether MSCT can reliably triage patients with suspected coronary artery disease (CAD) to coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or no revascularization. MATERIALS AND METHODS: A total of 123 patients with suspected CAD who were referred for conventional coronary angiography (CATH) additionally underwent MSCT (16*0.5 mm detector collimation). Therapeutic decisions made on the basis of CATH and MSCT strictly following current guidelines for treatment of CAD were compared with decisions made by a cardiac surgeon and an interventional cardiologist. Only MSCTs with at least adequate image quality in all coronary segments were included in the analysis (94/123). RESULTS: Decisions made on the basis of MSCT and CATH according to guidelines did not differ significantly (agreement of 88%, 82 of 94, P = .319). The therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH differed significantly (overall agreement of 79%, 74 of 94 cases, P < .001; cardiologist: 78% PCI and 22% CABG versus surgeon: 38% PCI and 62% CABG), whereas there was 100% agreement regarding decisions for or against invasive treatment. CONCLUSIONS: MSCT shows good agreement with CATH in triaging patients with suspected CAD to CABG, PCI, or no revascularization. The choice of revascularization procedure is significantly more strongly influenced by whether an interventional cardiologist or a cardiac surgeon makes the decision than by the diagnostic test on which the decision is based.     

Systemic lidocaine shortens length of hospital stay after colorectal surgery: a double-blinded, randomized, placebo-controlled trial

OBJECTIVE: To characterize the beneficial effects of perioperative systemic lidocaine on length of hospital stay, gastrointestinal motility, and the inflammatory response after colorectal surgery. SUMMARY BACKGROUND DATA: Surgery-induced stimulation of the inflammatory response plays a major role in the development of several postoperative disorders. Local anesthetics possess anti-inflammatory activity and are thought to positively affect patients' outcome after surgery. This double-blinded, randomized, and placebo-controlled trial aimed to evaluate beneficial effects of systemic lidocaine and to provide insights into underlying mechanisms. METHODS: Sixty patients undergoing colorectal surgery, not willing or unable to receive an epidural catheter, were randomly assigned to lidocaine or placebo treatment. Before induction of general anesthesia, an intravenous lidocaine bolus (1.5 mg/kg) was administered followed by a continuous lidocaine infusion (2 mg/min) until 4 hours postoperatively. Length of hospital stay, gastrointestinal motility, and pain scores were recorded and plasma levels or expression of pro- and anti-inflammatory mediators determined. RESULTS: Lidocaine significantly accelerated return of bowel function and shortened length of hospital stay by one day. No difference could be observed in daily pain ratings. Elevated plasma levels of IL-6, IL-8, complement C3a, and IL-1ra as well as expression of CD11b, L- and P-selectin, and platelet-leukocyte aggregates were significantly attenuated by systemic lidocaine. CONCLUSIONS: Perioperative intravenous lidocaine not only improved gastrointestinal motility but also shortened length of hospital stay significantly. Anti-inflammatory activity modulating the surgery-induced stress response may be one potential mechanism. Systemic lidocaine may thus provide a convenient and inexpensive approach to improve outcome for patients not suitable for epidural anesthesia.     

Drosophila motor axons recognize and follow a Sidestep-labeled substrate pathway to reach their target fields

During development of the Drosophila nervous system, migrating motor axons contact and interact with different cell types before reaching their peripheral muscle fields. The axonal attractant Sidestep (Side) is expressed in most of these intermediate targets. Here, we show that motor axons recognize and follow Side-expressing cell surfaces from the ventral nerve cord to their target region. Contact of motor axons with Side-expressing cells induces the down-regulation of Side. In the absence of Side, the interaction with intermediate targets is lost. Misexpression of Side in side mutants strongly attracts motor axons to ectopic sites. We provide evidence that, on motor axons, Beaten path Ia (Beat) functions as a receptor or part of a receptor complex for Side. In beat mutants, motor axons no longer recognize Side-expressing cell surfaces. Furthermore, Beat interacts with Side both genetically and biochemically. These results suggest that the tracing of Side-labeled cell surfaces by Beat-expressing growth cones is a major principle of motor axon guidance in Drosophila.     

The protein tyrosine kinase Tec regulates mast cell function

Mast cells play crucial roles in a variety of normal and pathophysiological processes and their activation has to be tightly controlled. Here, we demonstrate that the protein tyrosine kinase Tec is a crucial regulator of murine mast cell function. Tec was activated upon FcεRI stimulation of BM‐derived mast cells (BMMC). The release of histamine in the absence of Tec was normal in vitro and in vivo; however, leukotriene C₄ levels were reduced in Tec^?/? BMMC. Furthermore, the production of IL‐4 was severely impaired, and GM‐CSF, TNF‐α and IL‐13 levels were also diminished. Finally, a comparison of WT, Tec^?/?, Btk^?/? and Tec^?/?Btk^?/? BMMC revealed a negative role for Btk in the regulation of IL‐4 production, while for the efficient production of TNF‐α, IL‐13 and GM‐CSF, both Tec and Btk were required. Our results demonstrate a crucial role for Tec in mast cells, which is partially different to the function of the well‐characterized family member Btk.