The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
Abstract 10 embalmed cadaver forearms and wrists were dissected to determine the anatomical course of the superficial branch of the
radial nerve in the distal forearm. The superficial radial nerve bifurcated in two branches at a mean of 54,7 mm proximal
to the radial styloid. From the styloid process of the radius, the mean distance to the closest dorsal branch of the superficial
radial nerve was 3,5 mm and the mean distance to the closest volar branch was 9,8 mm. The mean distance between the closest
branch of the superficial radial nerve and Lister?s tubercle was 16,4 mm. The crossing point between the nerve and the cephalic
vein was located at a mean of 54,3 mm proximal to the styloid process. At the level of styloid process the mean distance between
the closest dorsal branch of the superficial radial nerve and the first dorsal compartment was 15,2 mm and between the closest
volar branch and the first dorsal compartment 4,4 mm. Detailed knowledge of anatomic characteristics of the superficial branch
of the radial nerve may help prevent injury during operations and treat traumatic lesions of the nerve. Because of great variations
in the course of the superficial radial nerve we could not define an absolute safe zone for surgical procedures on the distal
forearm. Iatrogenic lesions of the superficial radial nerve are described complications of percutaneous procedures. Therefore
open surgical approaches are recommended.
Daniela Klitscher and Lars Peter Müller contributed equally to this work. 相似文献
Optimal treatment of Smith's fracture remains controversial. Conservative management of type III fractures is acceptable, but results are moderate for types I and II.
This study includes 53 patients operated on during the past 10 years; six of type I, 17 of type II and 30 of type III.
The functional end result was good in 32 cases (60.3 per cent) and excellent in nine cases (16.9 per cent).
Functional results of types I, II and III were comparable when the excellent and good groups were added together.
There was no correlation between anatomical result and functional outcome (κ = 0.07), although a good anatomical result usually accompanied a good to excellent functional end result. Operative treatment of Smith's fractures have good functional end results in our hands, regardless of the fracture type. 相似文献
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease. 相似文献
The operative results in 65 patients with 66 tibial shaft fractures and severe soft tissue injuries, stabilized by an external fixation frame according to Hoffmann or Vidal-Adrey, are reviewed and the treatment principles are discussed. Four patients required secondary amputations. Fifty-three patients could be followed up for an average of 23.2 months. The infection rate was 9.2% and nonunion was found in 11.1% of cases. Two patients had a refracture after removal of the fixation device. Twenty-three patients (42.6%) required one or more secondary operations. Of the 65 patients, 70.4% had very good or good end results, 16.7% acceptable, and 12.9% poor. External fixation according to Hoffmann or Vidal-Adrey affords excellent definitive stabilization in simple fractures of the lower leg with soft tissue injuries. In comminuted fractures of the lower leg with loss of bone fragments and severe tissue damage, external fixation is better used as a means of temporary stabilization until soft tissues permit definitive rigid stabilization. 相似文献