[show abstract][hide abstract] ABSTRACT: To prospectively evaluate 7 Tesla time-of-flight (TOF) magnetic resonance angiography (MRA) in comparison to 1.5 Tesla TOF MRA and 7 Tesla non-contrast enhanced magnetization-prepared rapid acquisition gradient-echo (MPRAGE) for delineation of unruptured intracranial aneurysms (UIA).
Sixteen neurosurgical patients (male n = 5, female n = 11) with single or multiple UIA were enrolled in this trial. All patients were accordingly examined at 7 Tesla and 1.5 Tesla MRI utilizing dedicated head coils. The following sequences were obtained: 7 Tesla TOF MRA, 1.5 Tesla TOF MRA and 7 Tesla non-contrast enhanced MPRAGE. Image analysis was performed by two radiologists with regard to delineation of aneurysm features (dome, neck, parent vessel), presence of artifacts, vessel-tissue-contrast and overall image quality. Interobserver accordance and intermethod comparisons were calculated by kappa coefficient and Lin's concordance correlation coefficient.
A total of 20 intracranial aneurysms were detected in 16 patients, with two patients showing multiple aneurysms (n = 2, n = 4). Out of 20 intracranial aneurysms, 14 aneurysms were located in the anterior circulation and 6 aneurysms in the posterior circulation. 7 Tesla MPRAGE imaging was superior over 1.5 and 7 Tesla TOF MRA in the assessment of all considered aneurysm and image quality features (e.g. image quality: mean MPRAGE7T: 5.0; mean TOF7T: 4.3; mean TOF1.5T: 4.3). Ratings for 7 Tesla TOF MRA were equal or higher over 1.5 Tesla TOF MRA for all assessed features except for artifact delineation (mean TOF7T: 4.3; mean TOF1.5T 4.4). Interobserver accordance was good to excellent for most ratings.
7 Tesla MPRAGE imaging demonstrated its superiority in the detection and assessment of UIA as well as overall imaging features, offering excellent interobserver accordance and highest scores for all ratings. Hence, it may bear the potential to serve as a high-quality diagnostic tool for pretherapeutic assessment and follow-up of untreated UIA.
PLoS ONE 01/2014; 9(1):e84562. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Background The aim of this study is to report about a preliminary experience with a new minimally invasive percutaneous transpedicular dorsal stabilization system (MANTIS, Stryker, Kalamazoo, MI, USA) for thoracolumbar and lumbar spinal diseases to demonstrate the benefits of the operative technique and drawbacks.Material and Methods The minimally invasive percutaneous transpedicular stabilization technique was performed in 52 patients with thoracolumbar and lumbar spinal diseases from February 2009 to August 2010. The average age of 25 male and 27 female patients was 60 years (range 15 to 81 years). Visual analog scale (VAS) was used for pre- and postoperative evaluation of pain. In all patients, preoperative magnetic resonance imaging and computed tomography (CT) scan were performed to evaluate the neuronal and bony structures. Screw position of all operated segments was controlled by postoperative CT scan.Results Indication for surgery was spondylolisthesis in 28 cases (53.8%), vertebral fracture in 15 cases (28.8%), vertebral metastasis in 8 patients (15.4%), and spondylodiscitis in 1 patient (1.9%). Decompressive laminectomy was performed in 37 cases (71.2%). An additional interbody fusion was necessary in 26 patients (50%) due to degenerative motion spondylolisthesis. All patients showed pain improvement after surgery. The average preoperative VAS score was 7.98 (minimum 5 and maximum 10) and improved after surgery to 2.15 (minimum 0 and maximum 8). The rate of screw misplacement was 4.62% (10 of 216 screws). We revised three screws (1.38%) in three different patients (5.6%) due to suboptimal screw position although these patients had no neurological deterioration. Postoperative complications include cerebrospinal fluid leakage in four cases (7.7%), which occurred during the decompressive procedure. One patient showed a postoperative hematoma located in the paravertebral muscle.Conclusion Minimally invasive transpedicular screw stabilization systems such as the MANTIS lead to safe and effective procedures. They can be used for different spinal disorders and can be combined with additional surgical procedures such as intervertebral fusion or decompression, if necessary.
Journal of neurological surgery. Part A, Central European neurosurgery. 06/2012; 73(6):369-76.