Morphological analysis in patients with sciatica: a magnetic resonance imaging study using three-dimensional high-resolution diffusion-weighted magnetic resonance neurography techniques.

STUDY DESIGN: A prospective observational study of patients with sciatica. OBJECTIVE: We investigated the effectiveness of 3-dimensional high-spatial resolution diffusion-weighted MR neurography based on steady state free precession (3-dimensional diffusion-weighted steady-state free precession [DW-SSFP]) in the diagnosis of sciatica. SUMMARY OF BACKGROUND DATA: Patients with sciatica challenge a physician who desires a precise diagnosis for the etiology of the pain. Direct imaging of the sciatic nerve with high resolution and high contrast may contribute to accurate localization and help to find the causes of sciatica and provide reliable information to clinicians in treatment choice. Thus, we supposed that 3-dimensional DW-SSFP method have the ability to confirm the etiologies of sciatica. METHODS: The 3-dimensional DW-SSFP sequence was performed on 137 patients with sciatica and 32 patients in control group. The postprocessing techniques were used to generate images of lumbosacral plexus and sciatic nerve, and the images acquired were assessed based on the presence or absence of nerve abnormality. The certainty of identifying the lumbosacral plexus and main branches from all cases was determined in each of the reconstruction planes for each case individually and assessed by using a 3-score scale. RESULTS: All subjects were successfully performed. The sciatic nerve and its main branches were differentiated and a clear picture was obtained in all subjects. Compared with the control group, the presence of nerve root compression or increased T2 signal intensity changes can be observed in all patients. The mean score of certainty of identifying the sciatic nerve and main branches was 1.76 +/- 0.4, which indicate that the sciatic nerve and main branches can be identified with certainty. CONCLUSION: The 3-dimensional DW-SSFP MRI with high spatial and sufficient contrast is an excellent technique to define the nature of sciatica and assists in prognostication and possibly in management.

Segmented echo planar MR imaging of the brachial plexus with inversion recovery magnetization preparation at 3.0T.

PURPOSE: To evaluate the image quality of segmented echo planar MRI with inversion recovery magnetization preparation (seg-IR-EPI) to depict the anatomy and pathologic changes involving the brachial plexus. MATERIALS AND METHODS: The coronal seg-IR-EPI sequence was performed on 30 healthy volunteers and 20 patients. Postprocessing techniques were used to generate images of brachial plexus and the images acquired were qualitatively evaluated by two experienced radiologists based on grading of the morphological images. Signal-to-noise ratios (SNRs) and nerve soft tissue contrast-to-noise-ratios (CNRs) were calculated and the normalized SNR (SNRn) and the normalized CNR (CNRn) were compared with the STIR TSE sequence. RESULTS: Although seg-IR-EPI had more ghosting artifacts than STIR TSE, excellent general image appearance with minor blurring can be achieved with seg-IR-EPI. In all healthy volunteers the means of CNRn were significantly greater for seg-IR-EPI than for STIR-TSE, while the means of SNRn were significantly lower for seg-IR-EPI than for STIR-TSE. CONCLUSION: In the present study the seg-IR-EPI sequence obtained uniform fat suppression and high-contrast T2-weighted images of brachial plexus. Our data suggest that the seg-IR-EPI sequence may provide high fidelity in evaluating brachial plexus.

Cellular mechanisms of reduced sarcoplasmic reticulum Ca2+ content in L-thyroxin induced rat ventricular hypertrophy.

AIM: To examine how the sarcoplasmic reticulum (SR) Ca2+ content changes and the underlying mechanism in L-thyroxin-induced cardiac hypertrophy. METHODS: Echocardiography was used to confirm the establishment of the cardiac hypertrophy model. The confocal microscopy and fluorescent indicator Fluo-3 was applied to examine the intracellular Ca2+ concentration ([Ca2+]i), the Ca2+ sparks, and the caffeine-induced Ca2+ transient in freshly isolated cardiac ventricular myocytes. The activity of sarcolemmal and SR Ca2+-ATPase 2a (SERCA2a) in the ventricular tissue was also measured, respectively. RESULTS: L-thyroxin (1 mg/kg injection for 10 d) induces left ventricular cardiac hypertrophy with normal myocardial function. The decreased caffeine-induced Ca2+ transient in the Ca2+-free solution was detected. The spontaneous Ca2+ sparks in hypertrophied myocytes occurred more frequently than in normal cells, with similar duration and spatial spread, but smaller amplitude. Then the basal [Ca2+]i increase was observed in quiescent left ventricular myocytes from hyperthyroidism rats. The activity of sarcolemmal and SR Ca2+-ATPase was decreased in the hypertrophied ventricle tissue. CONCLUSION: The results suggested that the reduced SR Ca2+ content may be associated with an increased Ca2+ leak and reduced SERCA2a activity, contributing to abnormal intracellular Ca2+ handling during hypertrophy in hyperthyroidism rats.